WorldWideScience

Sample records for surface science emanated

  1. Detailed effects of particle size and surface area on 222Rn emanation of a phosphate rock.

    Science.gov (United States)

    Haquin, Gustavo; Yungrais, Zohar; Ilzycer, Danielle; Zafrir, Hovav; Weisbrod, Noam

    2017-12-01

    The dependency of radon emanation on soil texture was investigated using the closed chamber method. Ground phosphate rock with a large specific surface area was analyzed, and the presence of inner pores, as well as a high degree of roughness and heterogeneity in the phosphate particles, was found. The average radon emanation of the dry phosphate was 0.145 ± 0.016. The emanation coefficient was highest (0.169 ± 0.019) for the smallest particles (210 μm). The reduction rate followed an inverse power law. As expected, a linear dependence between the emanation coefficient and the specific surface area was found, being lower than predicted for the large specific surface area. This was most likely due to an increase in the embedding effect of radon atoms in adjacent grains separated by micropores. Results indicate that knowledge of grain radium distribution is crucial to making accurate emanation predictions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Biomaterials surface science

    CERN Document Server

    Taubert, Andreas; Rodriguez-Cabello, José Carlos

    2013-01-01

    The book provides an overview of the highly interdisciplinary field of surface science in the context of biological and biomedical applications. The covered topics range from micro- and nanostructuring for imparting functionality in a top-down manner to the bottom-up fabrication of gradient surfaces by self-assembly, from interfaces between biomaterials and living matter to smart, stimuli-responsive surfaces, and from cell and surface mechanics to the elucidation of cell-chip interactions in biomedical devices.

  3. Surface science and catalysis

    International Nuclear Information System (INIS)

    Somorjai, G.A.

    1985-02-01

    Modern surface science studies have explored a large number of metal catalyst systems. Three classes of catalytic reactions can be identified: (1) those that occur over the metal surface; (2) reactions that take place on top of a strongly adsorbed overlayer and (3) reactions that occur on co-adsorbate modified surfaces. Case histories for each class are presented. 44 refs., 13 figs., 3 tabs

  4. Surface science an introduction

    CERN Document Server

    Hudson, John

    1991-01-01

    The whole field of surface science is covered in this work. Starting with a description of the structure and thermodynamics of clean surfaces, the book goes on to discuss kinetic theory of gases and molecular beam formation. This is followed by a largesection on gas-surface interactions, and another major section on energetic particle-surface interactions. The final chapter provides the background to crystal nucleation and growth. The approach adopted is interdisciplinary and slanted towards theexperimental side, with practical analytical techniques being used to illustrate general princi

  5. Surface science techniques

    CERN Document Server

    Walls, JM

    2013-01-01

    This volume provides a comprehensive and up to the minute review of the techniques used to determine the nature and composition of surfaces. Originally published as a special issue of the Pergamon journal Vacuum, it comprises a carefully edited collection of chapters written by specialists in each of the techniques and includes coverage of the electron and ion spectroscopies, as well as the atom-imaging methods such as the atom probe field ion microscope and the scanning tunnelling microscope. Surface science is an important area of study since the outermost surface layers play a crucial role

  6. Surface science techniques

    CERN Document Server

    Bracco, Gianangelo

    2013-01-01

    The book describes the experimental techniques employed to study surfaces and interfaces. The emphasis is on the experimental method. Therefore all chapters start with an introduction of the scientific problem, the theory necessary to understand how the technique works and how to understand the results. Descriptions of real experimental setups, experimental results at different systems are given to show both the strength and the limits of the technique. In a final part the new developments and possible extensions of the techniques are presented. The included techniques provide microscopic as well as macroscopic information. They cover most of the techniques used in surface science.

  7. Solvay Conference on Surface Science

    CERN Document Server

    1988-01-01

    The articles collected in this volume give a broad overview of the current state of surface science. Pioneers in the field and researchers met together at this Solvay Conference to discuss important new developments in surface science, with an emphasis on the common area between solid state physics and physical chemistry. The contributions deal with the following subjects: structure of surfaces, surface science and catalysis, two-dimensional physics and phase transitions, scanning tunneling microscopy, surface scattering and surface dynamics, chemical reactions at surfaces, solid-solid interfaces and superlattices, and surface studies with synchrotron radiation. On each of these subjects an introductory review talk and a number of short research contributions are followed by extensive discussions, which appear in full in the text. This nineteenth Solvay Conference commemorates the 75th anniversary of the Solvay Institutes.

  8. Emanation of radon-222 in uraniferous phosphorite from Pernambuco, Brazil

    International Nuclear Information System (INIS)

    Santos, M.L.O.; França, E.J.; Amaral, D.S.; Silva, K.E.M.; Hazin, C.A.; Farias, E.E.G.

    2017-01-01

    The concentration of radon-222 activity available for transport to the surface through the pore space can be defined as radon emanation. From the decay of radium-226, whose half-life is 1850 years, it is associated with the development of neoplasia, such as lung cancer. In the Metropolitan Region of Recife, sedimentary rocks known as phosphorites have been known since 1959, so, from the radiometric characterization of the Paulista and Igarassu Municipality, in Pernambuco, emanation tests were carried out, aiming to determine the emanation power of radon in samples of uraniferous phosphorite from the Recife Metropolitan Region. Initially, 6 independent samples of phosphorites with activity concentration of 226 Ra> 400 Bq kg -1 were comminuted. Portions of 5g were conditioned in a radon chamber with 500 mL volume for measurements. The linear fit of the model converged after 200 interactions with selection of the best fit by the Chi-Square test, through the Origin® 8.0 program. After analysis of the samples, radon emanation power was estimated in the range of 7% to 15%, with a mean value of 10.8%. The methodology used to determine the emanation parameters in samples of uraniferous phosphorite was adequate, observing an inversely proportional relation between the concentration of the radium-226 and the emanation power

  9. Granulation effects on the radon emanation rate.

    Science.gov (United States)

    Bikit, I; Mrda, D; Grujic, S; Kozmidis-Luburic, U

    2011-05-01

    The radon emanation and the granulation effect on the emanation rate of several building materials (ceramic plates, sand, red brick and siporex brick) with different (226)Ra concentrations were investigated. A ball mill was used to achieve different granulations of the materials. The particle size distributions were determined by a particle size analyser (Mastersizer 2000). The increase in the (222)Rn concentration inside a closed chamber (volume ≈5.4 × 10(-3) m(3)) due to emanation from each material with different granulations was measured by an alpha spectrometer (RAD7). Thus, time-dependent curves for radon concentrations were obtained. The highest radon emanation coefficient (27 %) was obtained for the siporex sample with the smallest grain size (0.34 µm). For the ceramic pads, the granulation effect was negligible and the emanation coefficient was very low (∼0.4 %). The strongest influence of granulation on the radon emanation rate was found for the siporex brick sample.

  10. Undergraduate Laboratory for Surface Science

    Science.gov (United States)

    Okumura, Mitchio; Beauchamp, Jesse L.; Dickert, Jeffrey M.; Essy, Blair R.; Claypool, Christopher L.

    1996-02-01

    Surface science has developed into a multidisciplinary field of research with applications ranging from heterogeneous catalysis to semiconductor etching (1). Aspects of surface chemistry are now included in physical chemistry textbooks (2) and undergraduate curricula (3), but the perceived cost and complexity of equipment has deterred the introduction of surface science methods in undergraduate laboratories (4). Efforts to expose chemistry undergraduates to state-of-the-art surface instrumentation have just begun (5). To provide our undergraduates with hands-on experience in using standard techniques for characterizing surface morphology, adsorbates, kinetics, and reaction mechanisms, we have developed a set of surface science experiments for our physical chemistry laboratory sequence. The centerpiece of the laboratory is an ultrahigh vacuum (UHV) chamber for studies of single crystal surfaces. This instrument, shown in the figure, has surface analysis capabilities including low energy electron diffraction (LEED), Auger spectroscopy, and temperature-programmed desorption (TPD). The laboratory exercises involve experiments on the well-studied Pt(111) surface. Students prepare a previously mounted single crystal sample by sputtering it with an argon ion gun and heating it under O2. Electron diffraction patterns from the cleaned surface are then obtained with a reverse view LEED apparatus (Princeton Instruments). Images are captured by a charge-coupled device (CCD) camera interfaced to a personal computer for easy downloading and subsequent analysis. Although the LEED images from a Pt(111) surface can be readily interpreted using simple diffraction arguments, this lab provides an excellent context for introducing Miller indices and reciprocal lattices (6). The surface chemical composition can be investigated by Auger spectroscopy, using the LEED apparatus as a simple energy analyzer. The temperature programmed desorption experiment, which is nearly complete, will be

  11. Simultaneous and multi-point measurement of ammonia emanating from human skin surface for the estimation of whole body dermal emission rate.

    Science.gov (United States)

    Furukawa, Shota; Sekine, Yoshika; Kimura, Keita; Umezawa, Kazuo; Asai, Satomi; Miyachi, Hayato

    2017-05-15

    Ammonia is one of the members of odor gases and a possible source of odor in indoor environment. However, little has been known on the actual emission rate of ammonia from the human skin surface. Then, this study aimed to estimate the whole-body dermal emission rate of ammonia by simultaneous and multi-point measurement of emission fluxes of ammonia employing a passive flux sampler - ion chromatography system. Firstly, the emission fluxes of ammonia were non-invasively measured for ten volunteers at 13 sampling positions set in 13 anatomical regions classified by Kurazumi et al. The measured emission fluxes were then converted to partial emission rates using the surface body areas estimated by weights and heights of volunteers and partial rates of 13 body regions. Subsequent summation of the partial emission rates provided the whole body dermal emission rate of ammonia. The results ranged from 2.9 to 12mgh -1 with an average of 5.9±3.2mgh -1 per person for the ten healthy young volunteers. The values were much greater than those from human breath, and thus the dermal emission of ammonia was found more significant odor source than the breath exhalation in indoor environment. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. The surface science of enzymes

    DEFF Research Database (Denmark)

    Rod, Thomas Holm; Nørskov, Jens Kehlet

    2002-01-01

    One of the largest challenges to science in the coming years is to find the relation between enzyme structure and function. Can we predict which reactions an enzyme catalyzes from knowledge of its structure-or from its amino acid sequence? Can we use that knowledge to modify enzyme function......? To solve these problems we must understand in some detail how enzymes interact with reactants from its surroundings. These interactions take place at the surface of the enzyme and the question of enzyme function can be viewed as the surface science of enzymes. In this article we discuss how to describe...... catalysis by enzymes, and in particular the analogies between enzyme catalyzed reactions and surface catalyzed reactions. We do this by discussing two concrete examples of reactions catalyzed both in nature (by enzymes) and in industrial reactors (by inorganic materials), and show that although analogies...

  13. Modern techniques of surface science

    CERN Document Server

    Woodruff, D Phil

    2016-01-01

    This fully revised, updated and reorganised third edition provides a thorough introduction to the characterisation techniques used in surface science and nanoscience today. Each chapter brings together and compares the different techniques used to address a particular research question, including how to determine the surface composition, surface structure, surface electronic structure, surface microstructure at different length scales (down to sub-molecular), and the molecular character of adsorbates and their adsorption or reaction properties. Readers will easily understand the relative strengths and limitations of the techniques available to them and, ultimately, will be able to select the most suitable techniques for their own particular research purposes. This is an essential resource for researchers and practitioners performing materials analysis, and for senior undergraduate students looking to gain a clear understanding of the underlying principles and applications of the different characterisation tec...

  14. How old is surface science?

    International Nuclear Information System (INIS)

    Paparazzo, E.

    2004-01-01

    Philosophical and literary testimonies from the Classical World (5th century B.C. to 3rd century A.D.) involving solid surfaces are reviewed. Plato thought the surface to be a real entity, whereas Aristotle considered it to possess an unqualified existence, i.e. not to be a substance, but just an accidental entity. The Old Stoics asserted that surfaces do not possess any physical existence, although the Stoic philosopher Posidonius--apparently the only exception in his school--held them to exist both in thought and reality. While both the Atomists and the Epicureans were very little interested in them, the Sceptic philosopher Sextus Empiricus considered surfaces to be the limits of a body, although he maintained that both the view that they are corporeal or the view that they are incorporeal present unsurmountable difficulties. Among Roman authors, the testimony from Pliny the Elder is mostly concerned with metallic surfaces, chemical change occurring there, and surface treatments used in antiquity. Besides the philosophical motivations, the implications of the testimonies are discussed in the light of surface science. The purely geometrical surface of Plato is found to compare favorably to single-crystal surface, Posidonius' 'corporeal' surface is best likened to an air-oxidized, or otherwise ambient-modified surface, and ancient accounts on mixture are compared to XPS results obtained in adhesion studies of enameled steels. I argue that the long-standing dominance of Aristotle's view from antiquity onwards may have had a part in delaying theoretical speculation into solid surfaces

  15. How old is surface science?

    Energy Technology Data Exchange (ETDEWEB)

    Paparazzo, E. E-mail: paparazzo@ism.cnr.it

    2004-01-01

    Philosophical and literary testimonies from the Classical World (5th century B.C. to 3rd century A.D.) involving solid surfaces are reviewed. Plato thought the surface to be a real entity, whereas Aristotle considered it to possess an unqualified existence, i.e. not to be a substance, but just an accidental entity. The Old Stoics asserted that surfaces do not possess any physical existence, although the Stoic philosopher Posidonius--apparently the only exception in his school--held them to exist both in thought and reality. While both the Atomists and the Epicureans were very little interested in them, the Sceptic philosopher Sextus Empiricus considered surfaces to be the limits of a body, although he maintained that both the view that they are corporeal or the view that they are incorporeal present unsurmountable difficulties. Among Roman authors, the testimony from Pliny the Elder is mostly concerned with metallic surfaces, chemical change occurring there, and surface treatments used in antiquity. Besides the philosophical motivations, the implications of the testimonies are discussed in the light of surface science. The purely geometrical surface of Plato is found to compare favorably to single-crystal surface, Posidonius' 'corporeal' surface is best likened to an air-oxidized, or otherwise ambient-modified surface, and ancient accounts on mixture are compared to XPS results obtained in adhesion studies of enameled steels. I argue that the long-standing dominance of Aristotle's view from antiquity onwards may have had a part in delaying theoretical speculation into solid surfaces.

  16. Radon emanation on San Andreas Fault

    International Nuclear Information System (INIS)

    King, C.-Y.

    1978-01-01

    It is stated that subsurface radon emanation monitored in shallow dry holes along an active segment of the San Andreas fault in central California shows spatially coherent large temporal variations that seem to be correlated with local seismicity. (author)

  17. Radon emanation in tectonically active areas

    International Nuclear Information System (INIS)

    King, C.Y.

    1980-01-01

    Subsurface radon emanation has been continuously monitored for up to three years by the Track Etch method in shallow dry holes at more than 60 sites along several tectonic faults in central California and at 9 sites near the Kilauea volcano in Hawaii. The measured emanation in these tectonically active areas shows large long-term variations that may be related mainly to crustal strain changes

  18. Radon emanation coefficients in sandy soils

    International Nuclear Information System (INIS)

    Holy, K.; Polaskova, A.; Baranova, A.; Sykora, I.; Hola, O.

    1998-01-01

    In this contribution the results of the study of an influence of the water content on the emanation coefficient for two sandy soil samples are reported. These samples were chosen on the because of the long-term continual monitoring of the 222 Rn concentration just in such types of soils and this radon concentration showed the significant variations during a year. These variations are chiefly given in connection with the soil moisture. Therefore, the determination of the dependence of the emanation coefficient of radon on the water content can help to evaluate the influence of the soil moisture variations of radon concentrations in the soil air. The presented results show that the emanation coefficient reaches the constant value in the wide interval of the water content for both sandy soil samples. Therefore, in the common range of the soil moisture (5 - 20 %) it is impossible to expect the variations of the radon concentration in the soil air due to the change of the emanation coefficient. The expressive changes of the radon concentration in the soil air can be observed in case of the significant decrease of the emanation coefficient during the soil drying when the water content decreases under 5 % or during the complete filling of the soil pores by the water. (authors)

  19. Augmentation Award for Surface Science Research Training

    National Research Council Canada - National Science Library

    Sibener, Steven

    1996-01-01

    This AASERT grant provided augmentation funds that helped support US citizen graduate student research in the area of surface science as it pertains to gas-surface reactions, collisional energy transfer...

  20. Progress in surface and membrane science

    CERN Document Server

    Danielli, J F; Cadenhead, D A

    1973-01-01

    Progress in Surface and Membrane Science, Volume 6 covers the developments in the study of surface and membrane science. The book discusses the progress in surface and membrane science; the solid state chemistry of the silver halide surface; and the experimental and theoretical aspects of the double layer at the mercury-solution interface. The text also describes contact-angle hysteresis; ion binding and ion transport produced by neutral lipid-soluble molecules; and the biophysical interactions of blood proteins with polymeric and artificial surfaces. Physical chemists, biophysicists, and phys

  1. Progress in surface and membrane science

    CERN Document Server

    Cadenhead, D A

    1977-01-01

    Progress in Surface and Membrane Science, Volume 11 covers the advances in the study of surface and membrane science. The book discusses the quantum theory of surface phenomena; some fundamental aspects of electrocrystallization; and exoelectric emission. The text also describes the surface of titanium dioxide; and the prospects for atomic resolution electron microscopy in membranology. Chemists, physicists, and people involved in the electrochemical power laboratory will find the book useful.

  2. Surface Science Foundations of Catalysis and Nanoscience

    CERN Document Server

    Kolasinski, Kurt K

    2012-01-01

    Surface science has evolved beyond being a sub-field of chemistry or physics and has now become an underpinning science. The Third Edition of this book incorporates extensive worked solutions, as well as details on how problem solving relevant to surface science should be performed. It contextualizes the exercises and their solutions to further explicate the methods of problem solving, application of scientific principles and to deliver a deeper understanding of the field of surface science. Solutions will be accompanied by figures and/or graphs of data, as appropriate.

  3. Surface Science Foundations of Catalysis and Nanoscience

    CERN Document Server

    Kolasinski, Kurt K

    2012-01-01

    Surface science has evolved from being a sub-field of chemistry or physics, and has now established itself as an interdisciplinary topic. Knowledge has developed sufficiently that we can now understand catalysis from a surface science perspective. No-where is the underpinning nature of surface science better illustrated than with nanoscience. Now in its third edition, this successful textbook aims to provide students with an understanding of chemical transformations and the formation of structures at surfaces. The chapters build from simple to more advanced principles with each featuring exerc

  4. Progress in surface and membrane science

    CERN Document Server

    Danielli, J F; Cadenhead, D A

    1972-01-01

    Progress in Surface and Membrane Science, Volume 5 covers the developments in the study of surface and membrane science. The book discusses the Mössbauer effect in surface science; the surface functional groups on carbon and silica; and the wetting phenomena pertaining to adhesion. The text also describes the physical state of phospholipids and cholesterol in monolayers, bilayers, and membranes; the characteristics of heterocoagulation; and the effects of calcium on excitable membranes and neurotransmitter action. Chemists, physiologists, biophysicists, and civil engineers will find the book i

  5. Progress in surface and membrane science

    CERN Document Server

    Cadenhead, D A

    1979-01-01

    Progress in Surface and Membrane Science, Volume 12 covers the advances in the study of surface and membrane science. The book discusses the topographical differentiation of the cell surface; the NMR studies of model biological membrane system; and an irreversible thermodynamic approach to energy coupling in mitochondria and chloroplasts. The text also describes water at surfaces; the nature of microemulsions; and the energy principle in the stability of interfaces. Biochemists, physicists, chemical engineers, and people involved in surface and coatings research will find the book invaluable.

  6. Progress in surface and membrane science

    CERN Document Server

    Danielli, J F; Cadenhead, D A

    1971-01-01

    Progress in Surface and Membrane Science, Volume 4 covers the developments in the study of surface and membrane science. The book discusses waves at interfaces; recent investigations on the thickness of surface layers; and surface analysis by low-energy electron diffraction and Auger electron spectroscopy. The text also describes the anode electrolyte interface; the interactions of adsorbed proteins and polypeptides at interfaces; and peptide-induced ion transport in synthetic and biological membranes. The monolayer adsorption on crystalline surfaces is also considered. Chemists and metallurgi

  7. Topics in theoretical surface science

    Energy Technology Data Exchange (ETDEWEB)

    Todd, R.

    1991-10-25

    The energetics and structures of clean and adsorbate covered surfaces are investigated in this dissertation. First, the formalism, within the Corrected Effective Medium (CEM) method, for calculating the surface energy of a clean surface is derived. The surface energies for many different metals and their low index surfaces are presented. The minimization of the surface energy is then used to predict the multilayer relaxation of the Al(111), (100), Ni(100), (110) and Fe(100) surfaces. Extensions of the surface CEM formalism to calculate the binding energies of ordered adsorbates on metals surfaces are also derived. The minimization of the binding energy allowed determination of the binding heights, sites and the extent of induced multilayer relaxation for H and N atoms on the Fe(110), (100) and W(110) surfaces. The last topic deals with the dynamics of the epitaxial growth of metals on metal surfaces. The CEM method was first modified by making approximations to enable faster evaluations of the potential and its corresponding forces for molecular dynamics simulations. The goal of these simulations was to identify the important steps in the formation of equilibrium epitaxial structures. 180 refs., 31 figs., 18 tabs.

  8. Recent progress in surface science v.2

    CERN Document Server

    Danielli, J F; Riddiford, A C

    1964-01-01

    Recent Progress in Surface Science, Volume 2 is a 10-chapter text that covers the significant advances in some aspects of surface science, including in catalysis, genetic control of cell surface, and cell membrane. The opening chapter deals with the major factors affecting adsorption at the gas-solid interface. The subsequent chapters explore the advances in understanding of heterogeneous catalysis in terms of fundamental surface processes, as well as the concept of dynamic contact angles. These topics are followed by discussions on emulsions, flotation, and the extraordinary complexity of cel

  9. Progress in surface and membrane science

    CERN Document Server

    Cadenhead, D A; Rosenberg, M D

    1974-01-01

    Progress in Surface and Membrane Science, Volume 8 covers the developments in the study of surface and membrane science. The book discusses the applications of statistical mechanics to physical adsorption; the impact of electron spectroscopy and cognate techniques on the study of solid surfaces; and the ellipsometric studies of thin films. The text also describes the interfacial photochemistry of bilayer lipid membranes; cell junctions and their development; and the composition and function of the inner mitochondrial membrane. The role of the cell surface in contact inhibition of cell division

  10. Current trends of surface science and catalysis

    CERN Document Server

    Park, Jeong Young

    2014-01-01

    Including detail on applying surface science in renewable energy conversion, this book covers the latest results on model catalysts including single crystals, bridging "materials and pressure gaps", and hot electron flows in heterogeneous catalysis.

  11. Report of the surface science workshop

    Energy Technology Data Exchange (ETDEWEB)

    Somorjai, G.A.; Yates, J.T. Jr.; Clinton, W.

    1977-03-01

    A three-day workshop was held to review the various areas of energy development and technology in which surface science plays major roles and makes major contributions, and to identify the major surface-science-related problem areas in the fields with ERDA's mission in the fossil, nuclear, fusion, geothermal, and solar energy technologies and in the field of environmental control. The workshop activities are summarized. (GHT)

  12. Report of the surface science workshop

    International Nuclear Information System (INIS)

    Somorjai, G.A.; Yates, J.T. Jr.; Clinton, W.

    1977-03-01

    A three-day workshop was held to review the various areas of energy development and technology in which surface science plays major roles and makes major contributions, and to identify the major surface-science-related problem areas in the fields with ERDA's mission in the fossil, nuclear, fusion, geothermal, and solar energy technologies and in the field of environmental control. The workshop activities are summarized

  13. Progress in surface and membrane science

    CERN Document Server

    Cadenhead, D A; Rosenberg, M D

    1975-01-01

    Progress in Surface and Membrane Science, Volume 9 covers the developments in surface and membrane science. The book discusses the physical adsorption of gases and vapors in micropores; the chemisorption theory; and the role of radioisotopes in the studies of chemisorption and catalysis. The text also describes the interaction of ions with monolayers; and the isolation and characterization of mycoplasma membranes. Chemists, physical chemists, and microbiologists will find the book useful.

  14. Surface science tools for nanomaterials characterization

    CERN Document Server

    2015-01-01

    Fourth volume of a 40volume series on nano science and nanotechnology, edited by the renowned scientist Challa S.S.R. Kumar. This handbook gives a comprehensive overview about Surface Science Tools for Nanomaterials Characterization. Modern applications and state-of-the-art techniques are covered and make this volume an essential reading for research scientists in academia and industry.

  15. Progress in surface and membrane science

    CERN Document Server

    Cadenhead, D A

    1976-01-01

    Progress in Surface and Membrane Science, Volume 10 covers the advances in surface and membrane science. The book discusses the selective changes of cellular particles influencing sedimentation properties; and the rotating disk and ring-disk electrodes in investigations of surface phenomena at the metal-electrolyte interface. The text also describes the membrane potential of phospholipid bilayer and biological membranes; the adsorption of surfactant monolayers at gas/liquid and liquid/liquid interfaces; and the enzymes immobilized on glass. Chemists and people involved in electrochemistry will

  16. Technical activities, 1990: Surface Science Division

    International Nuclear Information System (INIS)

    Powell, C.J.

    1991-05-01

    The report summarizes technical activities and accomplishments of the NIST Surface Science Division during Fiscal Year 1990. Overviews are presented of the Division and of its three constituent groups: Surface Dynamical Processes, Thin Films and Interfaces, and Surface Spectroscopies and Standards. These overviews are followed by reports of selected technical accomplishments during the year. A summary is given of Division outputs and interactions that includes lists of publications, talks, committee assignments, seminars (including both Division seminars and Interface Science seminars arranged through the Division), conferences organized, and a standard reference material certified. Finally, lists are given of Division staff and of guest scientists who have worked in the Division during the past year

  17. Progress in surface and membrane science

    CERN Document Server

    Danielli, J F; Cadenhead, D A

    1973-01-01

    Progress in Surface and Membrane Science, Volume 7 covers the developments in the study of surface and membrane science. The book discusses the theoretical and experimental aspects of the van der Waals forces; the electric double layer on the semiconductor-electrolyte interface; and the long-range and short-range order in adsorbed films. The text also describes the hydrodynamical theory of surface shear viscosity; the structure and properties of monolayers of synthetic polypeptides at the air-water interface; and the structure and molecular dynamics of water. The role of glycoproteins in cell

  18. Progress in surface and membrane science

    CERN Document Server

    Cadenhead, D A

    1981-01-01

    Progress in Surface and Membrane Science, Volume 14 covers the advances in the study of surface and membrane science. The book discusses statistical thermodynamics of monolayer adsorption from gas and liquid mixtures on homogeneous and heterogeneous solid surfaces; and the structure of the boundary layers of liquids and its influence on the mass transfer in fine pores. The text then describes the coupling of ionic and non-electrolyte fluxes in ion selective membranes; the electrocatalytic properties of matalloporphins at the interface; and the adsorption from binary gas and liquid phases. Phas

  19. Surface analysis methods in materials science

    CERN Document Server

    Sexton, Brett; Smart, Roger

    1992-01-01

    The idea for this book stemmed from a remark by Philip Jennings of Murdoch University in a discussion session following a regular meeting of the Australian Surface Science group. He observed that a text on surface analysis and applica­ tions to materials suitable for final year undergraduate and postgraduate science students was not currently available. Furthermore, the members of the Australian Surface Science group had the research experience and range of coverage of sur­ face analytical techniques and applications to provide a text for this purpose. A of techniques and applications to be included was agreed at that meeting. The list intended readership of the book has been broadened since the early discussions, particularly to encompass industrial users, but there has been no significant alter­ ation in content. The editors, in consultation with the contributors, have agreed that the book should be prepared for four major groups of readers: - senior undergraduate students in chemistry, physics, metallur...

  20. Practical guide to surface science and spectroscopy

    CERN Document Server

    Chung, Yip-Wah

    2001-01-01

    Practical Guide to Surface Science and Spectroscopy provides a practical introduction to surface science as well as describes the basic analytical techniques that researchers use to understand what occurs at the surfaces of materials and at their interfaces. These techniques include auger electron spectroscopy, photoelectron spectroscopy, inelastic scattering of electrons and ions, low energy electron diffraction, scanning probe microscopy, and interfacial segregation. Understanding the behavior of materials at their surfaces is essential for materials scientists and engineers as they design and fabricate microelectronics and semiconductor devices. The book gives over 100 examples, discussion questions and problems with varying levels of difficulty. Included with this book is a CD-ROM, which not only contains the same information, but also provides many elements of animation and interaction that are not easily emulated on paper. In diverse subject matters ranging from the operation of ion pumps, computer-...

  1. Surface science principles and current applications

    CERN Document Server

    Taglauer, E; Wandelt, K

    1996-01-01

    Modern technologies increasingly rely on low-dimensional physics at interfaces and in thin-films and nano-structures. Surface science holds a key position in providing the experimental methods and theoretical models for a basic understanding of these effects. This book includes case studies and status reports about research topics such as: surface structure determination by tensor-LEED and surface X-ray diffraction; the preparation and detection of low-dimensional electronic surface states; quantitative surface compositional analysis; the dynamics of adsorption and reaction of adsorbates, e.g. kinetic oscillations; the characterization and control of thin-film and multilayer growth including the influence of surfactants; a critical assessment of the surface physics approach to heterogeneous catalysis.

  2. Radon emanation fractions from concretes containing fly ash and metakaolin

    Energy Technology Data Exchange (ETDEWEB)

    Taylor-Lange, Sarah C., E-mail: taylorlanges@utexas.edu [Department of Civil, Architectural, and Environmental Engineering, 1 University Station C1748, The University of Texas at Austin, Austin, TX 78712 (United States); Juenger, Maria C.G. [Department of Civil, Architectural, and Environmental Engineering, 1 University Station C1748, The University of Texas at Austin, Austin, TX 78712 (United States); Siegel, Jeffrey A. [Department of Civil, Architectural, and Environmental Engineering, 1 University Station C1748, The University of Texas at Austin, Austin, TX 78712 (United States); Department of Civil Engineering, 35 St. George Street, University of Toronto, Toronto, ON, M5S 1A4 (Canada)

    2014-01-01

    Radon ({sup 222}Rn) and progenies emanate from soil and building components and can create an indoor air quality hazard. In this study, nine concrete constituents, including the supplementary cementitious materials (SCMs) fly ash and metakaolin, were used to create eleven different concrete mixtures. We investigated the effect of constituent radium specific activity, radon effective activity and emanation fraction on the concrete emanation fraction and the radon exhalation rate. Given the serious health effects associated with radionuclide exposure, experimental results were coupled with Monte Carlo simulations to demonstrate predictive differences in the indoor radon concentration due to concrete mixture design. The results from this study show that, on average, fly ash constituents possessed radium specific activities ranging from 100 Bq/kg to 200 Bq/kg and emanation fractions ranging from 1.1% to 2.5%. The lowest emitting concrete mixture containing fly ash resulted in a 3.4% reduction in the concrete emanation fraction, owing to the relatively low emanation that exists when fly ash is part of concrete. On average, the metakaolin constituents contained radium specific activities ranging from 67 Bq/kg to 600 Bq/kg and emanation fractions ranging from 8.4% to 15.5%, and changed the total concrete emanation fraction by roughly ± 5% relative to control samples. The results from this study suggest that SCMs can reduce indoor radon exposure from concrete, contingent upon SCM radionucleotide content and emanation fraction. Lastly, the experimental results provide SCM-specific concrete emanation fractions for indoor radon exposure modeling. - Highlights: • Fly ash or metakaolin SCMs can neutralize or reduce concrete emanation fractions. • The specific activity of constituents is a poor predictor of the concrete emanation fraction. • Exhalation from fly ash concretes represents a small fraction of the total indoor radon concentration.

  3. Radon emanation fractions from concretes containing fly ash and metakaolin

    International Nuclear Information System (INIS)

    Taylor-Lange, Sarah C.; Juenger, Maria C.G.; Siegel, Jeffrey A.

    2014-01-01

    Radon ( 222 Rn) and progenies emanate from soil and building components and can create an indoor air quality hazard. In this study, nine concrete constituents, including the supplementary cementitious materials (SCMs) fly ash and metakaolin, were used to create eleven different concrete mixtures. We investigated the effect of constituent radium specific activity, radon effective activity and emanation fraction on the concrete emanation fraction and the radon exhalation rate. Given the serious health effects associated with radionuclide exposure, experimental results were coupled with Monte Carlo simulations to demonstrate predictive differences in the indoor radon concentration due to concrete mixture design. The results from this study show that, on average, fly ash constituents possessed radium specific activities ranging from 100 Bq/kg to 200 Bq/kg and emanation fractions ranging from 1.1% to 2.5%. The lowest emitting concrete mixture containing fly ash resulted in a 3.4% reduction in the concrete emanation fraction, owing to the relatively low emanation that exists when fly ash is part of concrete. On average, the metakaolin constituents contained radium specific activities ranging from 67 Bq/kg to 600 Bq/kg and emanation fractions ranging from 8.4% to 15.5%, and changed the total concrete emanation fraction by roughly ± 5% relative to control samples. The results from this study suggest that SCMs can reduce indoor radon exposure from concrete, contingent upon SCM radionucleotide content and emanation fraction. Lastly, the experimental results provide SCM-specific concrete emanation fractions for indoor radon exposure modeling. - Highlights: • Fly ash or metakaolin SCMs can neutralize or reduce concrete emanation fractions. • The specific activity of constituents is a poor predictor of the concrete emanation fraction. • Exhalation from fly ash concretes represents a small fraction of the total indoor radon concentration

  4. High radon emanation coefficients of porous matters produced through filtration and precipitation

    International Nuclear Information System (INIS)

    Sasaki, Tomozo; Gunji, Yasuyoshi

    2008-01-01

    Previous theoretical predictions of high radon emanation coefficients were verified in experiments using porous matters artificially produced through filtration and precipitation. Such porous matters were prepared by replicating uranium-bearing waste generating processes used in fuel fabrication facilities in Japan except that radium was employed instead of uranium. In the replication, a liquid containing a trace amount of naturally occurring radium was processed by filtration or precipitation, resulting in radium adsorption on the surfaces of the matrices used as agents for the processing. The matrices were diatomaceous earth for filtration and iron (III) hydroxide for precipitation. Radon emanation coefficients of these matrices were measured and proved to be very high as expected from the authors' previous theoretical calculations which predicted that chemical procedures like filtration or precipitation could lead to very high radon emanation coefficients. Filtration and precipitation are the most common processes employed in chemical industries. Therefore, the present study also provides important information on radon emanation coefficients for workers in those chemical industries which handle substances containing naturally occurring radium. The findings further imply that man-made artificial industrial products containing naturally occurring radium should be distinguished from ubiquitous minerals, rocks and soils containing naturally occurring radium from a radiological exposure viewpoint, because the radon emanation coefficients of the former are generally higher than those of the latter. (author)

  5. Theoretical aspects of the Semkow fractal model in the radon emanation in solids

    International Nuclear Information System (INIS)

    Cruz G, H.S.

    1997-01-01

    The basic elements of the Fractals theory are developed. The physical basis of radon emission in solids are described briefly. It is obtained that the emanation power E R of mineral grains is scaled as r 0 D-3 (r 0 : grain radius). From a logarithmic graph E R versus grain size is deduced the fractal dimension of the emanation surface. The experimental data of different materials give an interval in the fractal dimension D between 2.1 and 2.8 (Author)

  6. Single particle tomography in EMAN2.

    Science.gov (United States)

    Galaz-Montoya, Jesús G; Flanagan, John; Schmid, Michael F; Ludtke, Steven J

    2015-06-01

    Single particle tomography (SPT or subtomogram averaging) offers a powerful alternative to traditional 2-D single particle reconstruction for studying conformationally or compositionally heterogeneous macromolecules. It can also provide direct observation (without labeling or staining) of complexes inside cells at nanometer resolution. The development of computational methods and tools for SPT remains an area of active research. Here we present the EMAN2.1 SPT toolbox, which offers a full SPT processing pipeline, from particle picking to post-alignment analysis of subtomogram averages, automating most steps. Different algorithm combinations can be applied at each step, providing versatility and allowing for procedural cross-testing and specimen-specific strategies. Alignment methods include all-vs-all, binary tree, iterative single-model refinement, multiple-model refinement, and self-symmetry alignment. An efficient angular search, Graphic Processing Unit (GPU) acceleration and both threaded and distributed parallelism are provided to speed up processing. Finally, automated simulations, per particle reconstruction of subtiltseries, and per-particle Contrast Transfer Function (CTF) correction have been implemented. Processing examples using both real and simulated data are shown for several structures. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. The radium distribution in some Swedish soils and its effects on radon emanation

    International Nuclear Information System (INIS)

    Edsfeldt, Cecilia

    2001-08-01

    The aim of this study has been to clarify how the radium distribution in soils affects the radon emanation. The distribution of radium, uranium and thorium has been determined using sequential extractions. In the study, soils from two different locations were investigated. In the first part the applicability of the sequential extraction method for determining Ra distribution in different soil types was investigated, using a simple sequential extraction method. Sampled soils were clay, sand and till from the vicinity of the Stockholm Esker. The main part of Rn emanating Ra was associated with Fe oxides in the soil. The methods applied provided information about the radon risk of the soil, but, in order to gain more information on the processes governing Ra distribution and radon emanation in soils, a more detailed sequential extraction procedure would be desirable. The second part consisted of a detailed study of the radionuclide distribution and the geochemistry in a podzolised glacial till from Kloten in northern Vaestmanland. A more detailed sequential extraction procedure was used, and the specific surface area of samples was measured. Samples were taken from E, B, and C horizons; radium and thorium were enriched in the B horizon, whereas uranium had its maximum concentration in the C horizon. Extractable radium primarily occurred in the exchangeable pool, possibly organically complexed, whereas extractable uranium and thorium were mainly Fe oxide bound. Oxide-bound Ra was important only in the B horizon. The radon emanation was not correlated with the amount of exchangeable Ra, but instead with the oxide bound Ra. However, the amount of oxide-bound Ra was too small to account for all the emanated Rn, thus, exchangeable Ra was interpreted as the main source of emanated Rn. This exchangeable Ra was more emanative in the B horizon than in the C horizon. The explanation is the larger surface area of the B horizon samples; the specific surface area appears to be the

  8. Study on the change of aspect ratios of small surface cracks emanated from a toe of corner boxing; Mawashi yosetsudome tanbu kara hassei denpasuru bishi bisho hyomen kiretsu no aspect hi henka ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Toyosada, M.; Yamaguchi, K.; Takeda, K.; Watanabe, Y. [Kyushu University, Fukuoka (Japan). Faculty of Engineering

    1997-10-01

    The fatigue test of specimens with a stiffener was carried out to examine the change in aspect ratio (crack depth/length) of fatigue cracks in a stress concentration field and residual stress field. The aspect ratio of surface cracks just after generation can be represented with the single virtual surface crack with the same value as K value at the deepest point considering an interference effect from near cracks. No discontinuous change in K value is found at the deepest point even during growth and combination of cracks on a surface. The change in K value at the deepest point is thus the criterion to represent growth and combination of surface cracks considering the interference effect. The change in aspect ratio of the typical single virtual surface crack linearly decreases with an increase in crack depth. The shape of surface cracks generating and growing in a residual stress field is more flat than that in no residual stress field. In addition, in a residual stress field, surface cracks are longer at the same crack depth, and fatigue lives are shorter. 7 refs., 12 figs.

  9. Radon emanation fractions from concretes containing fly ash and metakaolin.

    Science.gov (United States)

    Taylor-Lange, Sarah C; Juenger, Maria C G; Siegel, Jeffrey A

    2014-01-01

    Radon ((222)Rn) and progenies emanate from soil and building components and can create an indoor air quality hazard. In this study, nine concrete constituents, including the supplementary cementitious materials (SCMs) fly ash and metakaolin, were used to create eleven different concrete mixtures. We investigated the effect of constituent radium specific activity, radon effective activity and emanation fraction on the concrete emanation fraction and the radon exhalation rate. Given the serious health effects associated with radionuclide exposure, experimental results were coupled with Monte Carlo simulations to demonstrate predictive differences in the indoor radon concentration due to concrete mixture design. The results from this study show that, on average, fly ash constituents possessed radium specific activities ranging from 100 Bq/kg to 200 Bq/kg and emanation fractions ranging from 1.1% to 2.5%. The lowest emitting concrete mixture containing fly ash resulted in a 3.4% reduction in the concrete emanation fraction, owing to the relatively low emanation that exists when fly ash is part of concrete. On average, the metakaolin constituents contained radium specific activities ranging from 67 Bq/kg to 600 Bq/kg and emanation fractions ranging from 8.4% to 15.5%, and changed the total concrete emanation fraction by roughly ±5% relative to control samples. The results from this study suggest that SCMs can reduce indoor radon exposure from concrete, contingent upon SCM radionucleotide content and emanation fraction. Lastly, the experimental results provide SCM-specific concrete emanation fractions for indoor radon exposure modeling. © 2013.

  10. The surface science of titanium dioxide

    Science.gov (United States)

    Diebold, Ulrike

    2003-01-01

    Titanium dioxide is the most investigated single-crystalline system in the surface science of metal oxides, and the literature on rutile (1 1 0), (1 0 0), (0 0 1), and anatase surfaces is reviewed. This paper starts with a summary of the wide variety of technical fields where TiO 2 is of importance. The bulk structure and bulk defects (as far as relevant to the surface properties) are briefly reviewed. Rules to predict stable oxide surfaces are exemplified on rutile (1 1 0). The surface structure of rutile (1 1 0) is discussed in some detail. Theoretically predicted and experimentally determined relaxations of surface geometries are compared, and defects (step edge orientations, point and line defects, impurities, surface manifestations of crystallographic shear planes—CSPs) are discussed, as well as the image contrast in scanning tunneling microscopy (STM). The controversy about the correct model for the (1×2) reconstruction appears to be settled. Different surface preparation methods, such as reoxidation of reduced crystals, can cause a drastic effect on surface geometries and morphology, and recommendations for preparing different TiO 2(1 1 0) surfaces are given. The structure of the TiO 2(1 0 0)-(1×1) surface is discussed and the proposed models for the (1×3) reconstruction are critically reviewed. Very recent results on anatase (1 0 0) and (1 0 1) surfaces are included. The electronic structure of stoichiometric TiO 2 surfaces is now well understood. Surface defects can be detected with a variety of surface spectroscopies. The vibrational structure is dominated by strong Fuchs-Kliewer phonons, and high-resolution electron energy loss spectra often need to be deconvoluted in order to render useful information about adsorbed molecules. The growth of metals (Li, Na, K, Cs, Ca, Al, Ti, V, Nb, Cr, Mo, Mn, Fe, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au) as well as some metal oxides on TiO 2 is reviewed. The tendency to 'wet' the overlayer, the growth morphology, the

  11. Theoretical concepts of fractal geometry semkow by radon emanation in solids

    International Nuclear Information System (INIS)

    Cruz G, H.

    1996-01-01

    The objective of this work is to introduce the fractal geometry concept to the study of gaseous emanations in solids, specially with reference to radon emission in mineral grains. The basic elements of fractals theory are developed. A fractal is defined as an auto similar subassembly, which fractal dimension is greater than the topological dimension. Starting from this, and making a brief description of the physicals basis of radon emission in solids, a model between emanation power (E R ) and the ratio s/v (surface to volume), is founded. A Gaussian model is assumed for extent of recoil from alpha decay of Ra-226. Using the results of Pfeifer it is obtained that distribution of pore size is scaled like Br -D-1 , where D: fractal[dimension, B: constant and r: pore radius. After an adequate mathematics expansion, it is found that the expression for emanation power is scaled like r 0 D-3 (r 0 grain radius). We may concluded that if we have a logarithmic graph of E R vs size of grain we can deduce the fractal dimension of the emanation surface. The experimental data of different materials provides an interval into fractal dimension D , between 2.1 to 2.86. (author). 5 refs., 1 tab

  12. Recent progress in surface science 3

    CERN Document Server

    Danielli, J F; Rosenberg, M D

    2013-01-01

    Recent Progress in Surface Science, Volume 3 covers topics on the structure and mechanisms of the cell membranes. The book discusses the incorporation of chemisorbed species; the recent developments in the study of epitaxy; and the ""diffusion"" or ""hydride"" component of overpotential at cathodes of the ""platinum metals"". The text also describes the mechanism of hydrogen exchange in proteins; the nuclear magnetic resonance studies of lipids, lipoproteins, and cell membranes; and the monolayers of synthetic phospholipids. The formation, electrical properties, transport, and excitability cha

  13. Uranium-bearing wastes and their radon emanation

    International Nuclear Information System (INIS)

    Sasaki, Tomozo; Imamura, Mitsutaka; Gunji, Yasuyoshi

    2007-01-01

    There are no data available with regard to radon emanation coefficients for uranium-bearing wastes; such data are needed for the assessment of radiation exposure from radon that will be generated in the distant future as one uranium progeny at shallow land disposal sites for uranium-bearing wastes. There are many kinds of uranium-bearing wastes. However, it is not necessary to measure the radon emanation coefficients for all of them for two reasons. First, the radon emanation coefficients for uranium-bearing wastes contaminated by dissolved uranium are determined by the uranium chemical form, the manner of uranium deposition on the waste matrix, and the size of the particles which constitute the waste matrix. Therefore, only a few representative measurements are sufficient for such uranium-bearing wastes. Second, it is possible to make theoretical calculations of radon emanation coefficients for uranium-bearing wastes contaminated by UO 2 particles before sintering. In the present study, simulated uranium-bearing wastes contaminated by dissolved uranium were prepared, their radon emanation coefficients were measured and radon emanation coefficients were calculated theoretically for uranium-bearing wastes contaminated by UO 2 particles before sintering. The obtained radon emanation coefficients are distributed at higher values than those for ubiquitous soils and rocks in the natural environment. Therefore, it is not correct to just compare uranium concentrations among uranium-bearing wastes, ubiquitous soils and rocks in terms of radiation exposure. The radon emanation coefficients obtained in the present study have to be employed together with the uranium concentration in uranium-bearing wastes in order to achieve proper assessment of radiation exposure. (author)

  14. Present knowledge of the effect of cracks on radon emanation from tailings, with implications for mine rehabilitation at Olympic Dam

    International Nuclear Information System (INIS)

    Storm, J.R.; Patterson, J.R.

    1997-01-01

    The weather parameters of air pressure, temperature, rainfall and wind speed affect the rate of radon-222 emanation from the surface of mine tailings. A second set of conditions which form cracks or fissures in tailings and their covers, will also affect the radon flux density and they must be considered in the design of any cover for a rehabilitation program. The Olympic Dam mine expansion program, beginning in 1995, involves a substantial increase in the size of the copper/uranium tailings. As part of monitoring and progressive rehabilitation of the tailings, the rate of emanation of radon-222 from tailings' surfaces was measured, with and without the gross defects of cracking. Theoretical predictions and measurements made in the U.S., are compared with rates of emanation from a cracked surface, modelled as homogeneous with additional surface area due to cracks

  15. Study of radon emanation from uranium mill tailings. Relations between radon emanating power and physicochemical properties of the material

    International Nuclear Information System (INIS)

    Pellegrini, D.

    1999-01-01

    The uranium extraction from ores leads to large amounts of mill tailings still containing radionuclides, such as thorium-230 and radium-226, which generate radon-222. Without protective action, radon exposition may be high enough to cause concern for health of populations living in the vicinity of an uranium mill tailings disposal. This exposition pathway has therefore to be taken into account in the radiological impact studies. The emanating power, i.e. the part of radon atoms which escape from the solid particles, is directly involved in the radon source term evaluation. It may be determined for a given material by laboratory measurements. Emanating powers from 0.08 to 0.33 have been obtained for mill tailings from Jouac (Limousin, France), at various moisture contents. In order to reduce the relations of dependence between some of the emanation parameters, more simple phases, kaolinite and polymeric resins, have been studied. Those experiments have led us to the selection of the mechanisms and the parameters to consider for the development of an emanation modelling. The whole of the results obtained point out the radon sorption, in various proportions depending on the materials. The moisture content influence on the emanation from materials containing fine particles have been confirmed: the emanation increases with this parameter until a continuous water film surrounding the particles have been formed, and then become constant. This 'water effect' occurs in a moisture content range, which depends on the material porosity. Elsewhere, the presence of amorphous phases may led to a high radon emanation. (author)

  16. Anomalous radon emanation linked to preseismic electromagnetic phenomena

    Directory of Open Access Journals (Sweden)

    Y. Omori

    2007-10-01

    Full Text Available Anomalous emanation of radon (222Rn was observed preceding large earthquakes and is considered to be linked to preseismic electromagnetic phenomena (e.g. great changes of atmospheric electric field and ionospheric disturbances. Here we analyze atmospheric radon concentration and estimate changes of electrical conditions in atmosphere due to preseismic radon anomaly. The increase of radon emanation obeys crustal damage evolution, following a power-law of time-to-earthquake. Moreover, the radon emanation decreases the atmospheric electric field by 40%, besides influencing the maximum strength of atmospheric electric field by 104–105 V/m enough to trigger ionospheric disturbances. These changes are within the ranges observed or explaining electromagnetic phenomena associated with large earthquakes.

  17. Radon emanation during compression, fracturing and heating of granites

    Science.gov (United States)

    Pili, E.; Nicolas, A.; Girault, F.; Schubnel, A.; Fortin, J.; Passelègue, F. X.; Richon, P.

    2013-12-01

    Radon emanation during compression, fracturing and heating of granites É. Pili1,2, A. Nicolas3, F. Girault3, A. Schubnel3, J. Fortin3, F. Passelègue3, P. Richon1 1CEA, DAM, DIF, F-91297 Arpajon, France 2Institut de Physique du Globe, Sorbonne Paris Cité, 1 rue Jussieu, F-75005 Paris, France 3Ecole Normale Supérieure, 24 rue Lhomond, F-75005 Paris, France Precursory radon emissions have been reported previously in various seismically active areas. Nevertheless such observations, only partially understood, are the subject of much skepticism. Radon-222 is a radioactive gas, daughter of radium-226 from alpha-decay in the uranium-238 decay chain that is naturally present in rocks and soils. Its escape is facilitated by preferential pathways such as fractures. Its half-life is 3.8 days only. As a consequence, radon may accumulate during short period only, and is thought to be released prior, during and after earthquakes as stress is discharged and new fluid pathways are made available. However, the physical processes involved in radon emanation during stress variations remain mostly unknown in the field and poorly studied in the laboratory. Here, we investigate radon emanation from various granite samples: Isla Craig, Westerly, La Peyratte and various leucogranites. Radon emanation and diffusion length, measured first on intact samples, are compared with measurements performed after heating at 850°C. Despite extensive thermal fracturing, radon emanation decreases irreversibly after heating compared to intact sample, and the higher the heating temperature the smaller the radon emanation. This is explained by the disappearance of water-film at grain boundaries, which plays an important role in radon percolation through the porous space, and then, at higher temperatures, by dehydration and melting of biotites where radium is concentrated. The recoil range of radon is likely shorter in melted biotites than in intact ones. The effect of mechanical fracturing on radon

  18. Thermochemical Surface Engineering: A Playground for Science and Innovation

    DEFF Research Database (Denmark)

    Christiansen, Thomas Lundin; Dahl, Kristian Vinter; Jellesen, Morten Stendahl

    2017-01-01

    at the surface. Current research and innovation activities are used to exemplify thermochemical surface engineering and the interplay of science and innovation. The examples given encompass aspects of the synthesis of extremely porous materials, low temperature surface hardening of stainless steel, surface...

  19. Discharge of water containing waste emanating from land to the ...

    African Journals Online (AJOL)

    The National Water Act, 1998 (Act 36 of 1998) mandates the Department of Water Affairs and Forestry to manage all water containing waste (wastewater), which emanates from land-based sources and which directly impact on the marine environment. These sources include sea outfalls, storm water drains, canals, rivers ...

  20. Emanation thermal analysis of SiC based materials

    Czech Academy of Sciences Publication Activity Database

    Bálek, V.; Zeleňák, V.; Mitsuhashi, T.; Bakardjieva, Snejana; Šubrt, Jan; Haneda, H.

    2002-01-01

    Roč. 67, č. 1 (2002), s. 83-89 ISSN 1418-2874 R&D Projects: GA MŠk ME 180 Grant - others:EFDA(XE) TTMA-001 Institutional research plan: CEZ:AV0Z4032918 Keywords : emanation thermal analysis * SEM * SiC nanocomposites Subject RIV: CA - Inorganic Chemistry Impact factor: 0.598, year: 2002

  1. 48 CFR 252.239-7000 - Protection against compromising emanations.

    Science.gov (United States)

    2010-10-01

    ... Security Agency National TEMPEST Standards (NACSEM No. 5100 or NACSEM No. 5100A, Compromising Emanations Laboratory Test Standard, Electromagnetics (U)); or (2) Other standards specified by this contract, including... standards specified. The Government may conduct additional tests— (1) At the installation site or contractor...

  2. Calculation of radon emanation from a radiferous pile

    International Nuclear Information System (INIS)

    Zettwoog, Pierre.

    1980-07-01

    The theory of unidimensional diffusion of radon in a porous medium, either radiferous or not, is presented taking into account the effects of humidity and the adsorption of radon on the medium. Experimental procedures for determining the two main characteristics of diffusion in a medium, the relaxation length of the diffusion of radon and the emanating power, are described [fr

  3. Transport properties and microstructure changes of talc characterized by emanation

    Czech Academy of Sciences Publication Activity Database

    Pérez-Maqueda, L. A.; Balek, Vladimír; Poyato, J.; Šubrt, Jan; Beneš, M.; Ramírez-Valle, V.; Buntseva, I.M.; Beckman, I. N.; Pérez-Rodríguez, J. L.

    2008-01-01

    Roč. 92, č. 1 (2008), s. 253-258 ISSN 1388-6150 R&D Projects: GA MŠk LC523 Grant - others:MST(ES) MAT 2005-04838 Institutional research plan: CEZ:AV0Z40320502 Keywords : DTA emanation thermal analysis * microstructure changes * radon diffusion Subject RIV: CA - Inorganic Chemistry Impact factor: 1.630, year: 2008

  4. Discharge of water containing waste emanating from land to the ...

    African Journals Online (AJOL)

    driniev

    containing waste (wastewater), which emanates from land-based sources and which directly impact on the marine environment. These sources include sea ... The development of an operational policy providing the strategic view on marine disposal, as well as the goal, basic principles, ground rules and management ...

  5. Workshop on surface and interface science at the ESRF

    Energy Technology Data Exchange (ETDEWEB)

    Norris, C.; Stierle, A.; Kasper, N.; Dosch, H.; Schmidt, S.; Hufner, S.; Moritz, W.; Fedley, Ch.S.; Rossi, G.; Durr Hermann, A.; Rohlsberger, R.; Dalmas, J.; Oughaddou, H.; Leandri, Ch.; Gay, J.M.; Treglia, G.; Le Lay, G.; Aufray, B.; Bunk, O.; Johnson, R.L.; Frenken, J.W.M.; Lucas, C.A.; Bauer, G.; Zhong, Z.; Springholz, G.; Lechner, R.; Stang, J.; Schulli, T.; Metzger, T.H.; Holy, V.; Woodruff, D.P.; Dellera, C.; Zegenhagen, J.; Robinson, I.; Malachias, A.; Schulli, T.U.; Magalhaes-Paniago, R.; Stoffel, M.; Schmidt, O.G.; Boragno, C.; Buatier de Mongeot, F.; Valbusa, U.; Felici, R.; Yacoby, Y.; Bedzyk, M.J.; Van der Veen, J.F

    2004-07-01

    The main aim of the workshop is to reflect the future of surface and interface research at the high brilliance synchrotron radiation source ESRF taking into account experimental facilities which are becoming available at new synchrotron radiation facilities in Europe. 6 sessions have been organized: 1) surface and interface research and synchrotron radiation - today and tomorrow -, 2) aspects of surface and interface research, 3) real surfaces and interfaces, 4) synchrotron techniques in surface and interface research, 5) new directions in surface and interface research, and 6) surface and interface science at ESRF. This document gathers the abstracts of the presentations.

  6. Workshop on surface and interface science at the ESRF

    International Nuclear Information System (INIS)

    Norris, C.; Stierle, A.; Kasper, N.; Dosch, H.; Schmidt, S.; Hufner, S.; Moritz, W.; Fedley, Ch.S.; Rossi, G.; Durr Hermann, A.; Rohlsberger, R.; Dalmas, J.; Oughaddou, H.; Leandri, Ch.; Gay, J.M.; Treglia, G.; Le Lay, G.; Aufray, B.; Bunk, O.; Johnson, R.L.; Frenken, J.W.M.; Lucas, C.A.; Bauer, G.; Zhong, Z.; Springholz, G.; Lechner, R.; Stang, J.; Schulli, T.; Metzger, T.H.; Holy, V.; Woodruff, D.P.; Dellera, C.; Zegenhagen, J.; Robinson, I.; Malachias, A.; Schulli, T.U.; Magalhaes-Paniago, R.; Stoffel, M.; Schmidt, O.G.; Boragno, C.; Buatier de Mongeot, F.; Valbusa, U.; Felici, R.; Yacoby, Y.; Bedzyk, M.J.; Van der Veen, J.F.

    2004-01-01

    The main aim of the workshop is to reflect the future of surface and interface research at the high brilliance synchrotron radiation source ESRF taking into account experimental facilities which are becoming available at new synchrotron radiation facilities in Europe. 6 sessions have been organized: 1) surface and interface research and synchrotron radiation - today and tomorrow -, 2) aspects of surface and interface research, 3) real surfaces and interfaces, 4) synchrotron techniques in surface and interface research, 5) new directions in surface and interface research, and 6) surface and interface science at ESRF. This document gathers the abstracts of the presentations

  7. Emanation-thermal analysis in investigations of nonstoichiometric defects

    International Nuclear Information System (INIS)

    Os'kina, T.E.; Kapustin, O.A.; Zaborenko, K.B.

    1985-01-01

    A model, permitting on the basis of emanation-thermal analysis results to evaluate the interrelation between self-diffusion and diffusion parameters of impurity (including radon) in supposition of different mechanisms of defect formation, conditioning crystal nonstoichiometry, is proposed. Motive force of diffusion process in solid body depends on the charge of the particle diffusing (matrix proper ion or radon neutral ion), on the mechanism of defect formation and ratios of particle dimensions and lattice constant. The model adequacy is tested, using the systems of thorium hydrides and nonstoichiometric phases of tin dioxide. An example of mathematical treatment of emanation curves, permitting to relate diffusion parameters of radon-220 in the system with the type and concentration of nonstoichiometric defects, appearing in the matrix, is given

  8. Recalibration of the 226Ra emanation analysis system

    International Nuclear Information System (INIS)

    Lucas, H.F. Jr.; Markun, F.

    1982-01-01

    The 226 Ra emanation system was found to require recalibration. The gain of the various counting systems was established to about +-0.5%. The variance introduced into the analysis by multiple counting systems was low and corresponded to a fractional standard deviation of +-0.5%. The variance introduced into the analysis by both multiple counting systems and multiple counting chambers needs to be redetermined but is less than a fractional standard deviation of +-2%. The newly established calibration factor of 5.66 cpm/pg 226 Ra is about 6% greater than that used previously. The leakage of radon into the greased fittings of the emanation flask which was indicated in an earlier study was not confirmed

  9. Near- to far-field imaging of phase evolution of light emanating from a metal nanoslit.

    Science.gov (United States)

    Jung, Yun Suk; Xi, Yonggang; Wuenschell, Jeff; Kim, Hong Koo

    2008-11-10

    We report near- to far-field measurement of optical wavefronts emanating from a nanoslit formed in a thin (50 nm thick) Ag film. The evolution of optical phases is imaged using a self-interference technique in conjunction with a scanning probe method. The phase relationship of the slit-transmitted waves with respect to the direct transmission through the thin metal film is quantitatively established. The singular-phase points resulting from the interplay of slit diffraction and surface plasmons are identified in the intermediate-field region.

  10. Learning in Science: A Comparison of Deep and Surface Approaches.

    Science.gov (United States)

    Chin, Christine; Brown, David E.

    2000-01-01

    Explores the differences between deep and surface approaches to learning science. Findings indicate that the deep-surface learning differences fall into five categories: (1) generative thinking; (2) nature of explanations; (3) asking questions; (4) metacognitive activity; and (5) approach to tasks. Suggests that teachers can encourage a deep…

  11. Surface enhanced raman spectroscopy analytical, biophysical and life science applications

    CERN Document Server

    Schlücker, Sebastian

    2013-01-01

    Covering everything from the basic theoretical and practical knowledge to new exciting developments in the field with a focus on analytical and life science applications, this monograph shows how to apply surface-enhanced Raman scattering (SERS) for solving real world problems. From the contents: * Theory and practice of SERS * Analytical applications * SERS combined with other analytical techniques * Biophysical applications * Life science applications including various microscopies Aimed at analytical, surface and medicinal chemists, spectroscopists, biophysicists and materials scientists. Includes a Foreword by the renowned Raman spectroscopist Professor Wolfgang Kiefer, the former Editor-in-Chief of the Journal of Raman Spectroscopy.

  12. 7th International Summer Institute in Surface Science

    CERN Document Server

    Howe, Russell

    1986-01-01

    This volume contains review articles which were written by the invited speak­ ers of the seventh International Summer Institute in Surface Science (ISISS), held at the University of Wisconsin - Milwaukee in July 1985. The form of ISISS is a set of tutorial review lectures presented over a one-week period by internationally recognized experts on various aspects of surface science. Each speaker is asked, in addition, to write a review article on his lecture topic. No single volume in the series Chemistry and Physics of Solid Surfaces can possibly cover the entire field of modern surface science. However, the series as a whole is intended to provide experts and students alike with a comprehensive set of reviews and literature references, particularly empha­ sizing the gas-solid interface. The collected articles from previous Summer Institutes have been published under the following titles: Surface Science: Recent Progress and Perspectives, Crit. Rev. Solid State Sci. 4, 125-559 (1974) Chemistry and Physics of ...

  13. The development of surface science in China: Retrospect and prospects

    Energy Technology Data Exchange (ETDEWEB)

    Xie Xide (Fudan University, Shanghai (China))

    1994-01-01

    It is generally agreed that the year of 1977 marked the birth of surface science in China, therefore the length of its history of development is only half of that shown in the title of this volume. Since 1977 laboratories with modern facilities for surface studies have been established in various universities and research institutes. Three open laboratories better equipped than others have been set up in Beijing, Xiamen and Shanghai for surface physics, surface chemistry and applied surface physics, respectively. Five National Conferences on Physics of Surfaces and Interfaces were held in 1982, 1984, 1985, 1988 and 1991. In 1993 China is going to host the Fourth International Conference on the Structure of Surfaces in Shanghai August 16-19 which will serve as a milestone in the history of development of surface science in China. With the access to many overseas laboratories, quite a number of Chinese scientists and students have had opportunities to work and study abroad and have brought back with them experiences acquired. During the Conferences just mentioned, one could witness a number of steady progresses made over the years. In the present review, a brief description about the establishment of some major research facilities and progresses of some of the research is given with emphasis on work related to semiconductor surfaces, interfaces, superlattices, heterojunctions and quantum wells. Although the review nominally covers the development of research in surface science in China, due to the limitation of the capabilities of the author, mostly work done at Fudan University is included. For this the author would like to express her deep apology to many Chinese colleagues whose works have not been properly mentioned

  14. Molecular surface science of heterogeneous catalysis. History and perspective

    International Nuclear Information System (INIS)

    Somorjai, G.A.

    1983-08-01

    A personal account is given of how the author became involved with modern surface science and how it was employed for studies of the chemistry of surfaces and heterogeneous catalysis. New techniques were developed for studying the properties of the surface monolayers: Auger electron spectroscopy, LEED, XPS, molecular beam surface scattering, etc. An apparatus was developed and used to study hydrocarbon conversion reactions on Pt, CO hydrogenation on Rh and Fe, and NH 3 synthesis on Fe. A model has been developed for the working Pt reforming catalyst. The three molecular ingredients that control catalytic properties are atomic surface structure, an active carbonaceous deposit, and the proper oxidation state of surface atoms. 40 references, 21 figures

  15. Molecular surface science of heterogeneous catalysis. History and perspective

    Energy Technology Data Exchange (ETDEWEB)

    Somorjai, G.A.

    1983-08-01

    A personal account is given of how the author became involved with modern surface science and how it was employed for studies of the chemistry of surfaces and heterogeneous catalysis. New techniques were developed for studying the properties of the surface monolayers: Auger electron spectroscopy, LEED, XPS, molecular beam surface scattering, etc. An apparatus was developed and used to study hydrocarbon conversion reactions on Pt, CO hydrogenation on Rh and Fe, and NH/sub 3/ synthesis on Fe. A model has been developed for the working Pt reforming catalyst. The three molecular ingredients that control catalytic properties are atomic surface structure, an active carbonaceous deposit, and the proper oxidation state of surface atoms. 40 references, 21 figures. (DLC)

  16. A molecular surface science study of the structure of adsorbates on surfaces: Importance to lubrication

    International Nuclear Information System (INIS)

    Mate, C.M.

    1986-09-01

    The interaction and bonding of atoms and molecules on metal surfaces is explored under ultra-high vacuum conditions using a variety of surface science techniques: high resolution electron energy loss spectroscopy (HREELS), low energy electron diffraction (LEED), thermal desorption spectroscopy (TDS), Auger electron spectroscopy (AES), work function measurements, and second harmonic generation (SHG). 164 refs., 51 figs., 3 tabs

  17. Chemical beam epitaxy — a child of surface science

    Science.gov (United States)

    Lüth, Hans

    1994-01-01

    Chemical Beam Epitaxy (CBE) or MOMBE is currently one of the major deposition techniques in semiconductor technology. The growth process is performed in a UHV chamber under low pressure conditions and the source material is supplied by molecular beams, such that only surface kinetics are determining the chemical reactions leading to growth of the epilayer. This paper intends to give a review on the development of this deposition technique. After considering the early period, where this epitaxy method started to develop, partially from ideas being born in surface science, some milestones in the further development and basic understanding are presented. The mutual interaction between CBE/MOMBE as a deposition technique and other fields of surface science is described as well as the impact on the deposition technology of other semiconductors (e.g. for Si-based material systems). Future prospects of CBE are finally discussed, particularly in comparison with the competing techniques MBE and MOCVD (metal-organic chemical vapor deposition).

  18. 8th International Summer Institute in Surface Science

    CERN Document Server

    Howe, Russell

    1988-01-01

    This volume contains review articles written by the invited speakers at the eighth International Summer Institute in Surface Science (ISISS 1987), held at the University of Wisconsin-Milwaukee in August of 1987. During the course of ISISS, invited speakers, all internationally recognized experts in the various fields of surface science, present tutorial review lectures. In addition, these experts are asked to write review articles on their lecture topic. Former ISISS speakers serve as advisors concerning the selection of speakers and lecture topics. Em­ phasis is given to those areas which have not been covered in depth by recent Summer Institutes, as well as to areas which have recently gained in significance and in which important progress has been made. Because of space limitations, no individual volume of Chemistry and Physics of Solid Surfaces can possibly cover the whole area of modem surface science, or even give a complete survey of recent pro­ gress in the field. However, an attempt is made to pres...

  19. 48 CFR 239.7102-2 - Compromising emanations-TEMPEST or other standard.

    Science.gov (United States)

    2010-10-01

    ... INFORMATION TECHNOLOGY Security and Privacy for Computer Systems 239.7102-2 Compromising emanations—TEMPEST or other standard. For acquisitions requiring information assurance against compromising emanations, the...

  20. High resolution single particle refinement in EMAN2.1.

    Science.gov (United States)

    Bell, James M; Chen, Muyuan; Baldwin, Philip R; Ludtke, Steven J

    2016-05-01

    EMAN2.1 is a complete image processing suite for quantitative analysis of grayscale images, with a primary focus on transmission electron microscopy, with complete workflows for performing high resolution single particle reconstruction, 2-D and 3-D heterogeneity analysis, random conical tilt reconstruction and subtomogram averaging, among other tasks. In this manuscript we provide the first detailed description of the high resolution single particle analysis pipeline and the philosophy behind its approach to the reconstruction problem. High resolution refinement is a fully automated process, and involves an advanced set of heuristics to select optimal algorithms for each specific refinement task. A gold standard FSC is produced automatically as part of refinement, providing a robust resolution estimate for the final map, and this is used to optimally filter the final CTF phase and amplitude corrected structure. Additional methods are in-place to reduce model bias during refinement, and to permit cross-validation using other computational methods. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Implications of alteration processes on radon emanation, radon production rate and W-Sn exploration in the Panasqueira ore district.

    Science.gov (United States)

    Domingos, Filipa; Pereira, Alcides

    2018-05-01

    Alteration processes have strong impacts on the chemical and physical properties of rock masses. Because they can affect the contents and the distribution of U as well as enhance the permeability of the bedrock, they may lead to a significant increase of radon release to the environment. However, their influence on radon emanation and radon production rate has yet to be properly assessed. To investigate the impact of alteration processes on the radiological properties, samples were collected in the Panasqueira region under the influence of surface weathering, deuteric, hydrothermal and fault related alteration. Major and trace elements (U, Th), physical, and radiological properties were measured in metasedimentary and fault rocks. The degree of alteration and weathering progress were assessed through indices of alteration, porosity and bulk density. Overall, an increase of the radon emanation coefficient from (approximately) 0.1 to 0.4 and radon production rate (from 40 to over 160Bq·m -3 ·h -1 ) is observed with the progress of physicochemical alteration. Decoupling of physical and chemical alteration however implies both must be quantified towards a proper assessment of the degree of alteration. The behavior of radiogenic elements upon alteration is shown to be complex and contingent upon the alteration process. An atypical increase of radon emanation in the ore district due to U mobilization was caused by hydrothermal alteration. Because radon emanation is not dependent upon the pelitic nature of the metasedimentary rocks, it may thus become a proxy for W-Sn exploration. The dependency of radon production rate from the latter constrains its use for exploration. Nevertheless, it may provide a reliable estimation of the bedrock contribution to indoor radon concentrations. Higher indoor radon concentrations, hence, a higher risk of exposure to radon are expected in the ore district as well as within fault zones. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. A study of radon emanation from waste rock at Northern Territory uranium mines

    International Nuclear Information System (INIS)

    Mason, G.C.; Gan, T.H.; Elliott, G.

    1983-01-01

    Field measurements were made of radon emanation rates from waste rock sources at Ranger, Nabarlek and Rum Jungle, three Northern Territory uranium mine sites. The preliminary mean emanation rate was approximately 50 Bq m - 2 s - 2 per percent ore grade

  3. EDITORIAL: Focus on Advances in Surface and Interface Science 2008 FOCUS ON ADVANCES IN SURFACE AND INTERFACE SCIENCE 2008

    Science.gov (United States)

    Scheffler, Matthias; Schneider, Wolf-Dieter

    2008-12-01

    Basic research in surface and interface science is highly interdisciplinary, covering the fields of physics, chemistry, biophysics, geo-, atmospheric and environmental sciences, material science, chemical engineering, and more. The various phenomena are interesting by themselves, and they are most important in nearly all modern technologies, as for example electronic, magnetic, and optical devices, sensors, catalysts, lubricants, hard and thermal-barrier coatings, protection against corrosion and crack formation under harsh environments. In fact, detailed understanding of the elementary processes at surfaces is necessary to support and to advance the high technology that very much founds the prosperity and lifestyle of our society. Current state-of-the-art experimental studies of elementary processes at surfaces, of surface properties and functions employ a variety of sophisticated tools. Some are capable of revealing the location and motion of individual atoms. Others measure excitations (electronic, magnetic and vibronic), employing, for example, special light sources such as synchrotrons, high magnetic fields, or free electron lasers. The surprising variety of intriguing physical phenomena at surfaces, interfaces, and nanostructures also pose a persistent challenge for the development of theoretical descriptions, methods, and even basic physical concepts. This second focus issue on the topic of 'Advances in Surface and Interface Science' in New Journal of Physics, following on from last year's successful collection, provides an exciting synoptic view on the latest pertinent developments in the field. Focus on Advances in Surface and Interface Science 2008 Contents Organic layers at metal/electrolyte interfaces: molecular structure and reactivity of viologen monolayers Stephan Breuer, Duc T Pham, Sascha Huemann, Knud Gentz, Caroline Zoerlein, Ralf Hunger, Klaus Wandelt and Peter Broekmann Spin polarized d surface resonance state of fcc Co/Cu(001) K Miyamoto, K

  4. Surface science in hernioplasty: The role of plasma treatments

    Science.gov (United States)

    Nisticò, Roberto; Magnacca, Giuliana; Martorana, Selanna

    2017-10-01

    The aim of this review is to clarify the importance of surface modifications induced in biomaterials for hernia-repair application. Starting from the pioneering experiences involving proto-materials as ancient prosthesis, a historical excursus between the biomaterials used in hernioplasty was realized. Subsequently, after the revolutionary discovery of stereoregular polymerization followed by the PP application in the biomedical field performed by the surgeon F. Usher, a comparative study on different hernia-repair meshes available was realized in order to better understand all the outstanding problems and possible future developments. Furthermore, since many unsolved problems on prosthetic devices implantation are linked to phenomena occurring at the interface between the biomaterials surface and the body fluids, the importance of surface science in hernioplasty was highlighted and case studies of new surface-modified generations of prosthesis presented. The results discussed in the following evidence how the surface study are becoming increasingly important for a proper knowledge of issues related to the interaction between the living matter and the artificial prostheses.

  5. Reducing Motional Decoherence in Ion Traps with Surface Science Methods

    Science.gov (United States)

    Haeffner, Hartmut

    2014-03-01

    Many trapped ions experiments ask for low motional heating rates while trapping the ions close to trapping electrodes. However, in practice small ion-electrode distances lead to unexpected high heating rates. While the mechanisms for the heating is still unclear, it is now evident that surface contamination of the metallic electrodes is at least partially responsible for the elevated heating rates. I will discuss heating rate measurements in a microfabricated surface trap complemented with basic surface science studies. We monitor the elemental surface composition of the Cu-Al alloy trap with an Auger spectrometer. After bake-out, we find a strong Carbon and Oxygen contamination and heating rates of 200 quanta/s at 1 MHz trap frequency. After removing most of the Carbon and Oxygen with Ar-Ion sputtering, the heating rates drop to 4 quanta/s. Interestingly, we still measure the decreased heating rate even after the surface oxidized from the background gas throughout a 40-day waiting time in UHV.

  6. EDITORIAL: From reciprocal space to real space in surface science From reciprocal space to real space in surface science

    Science.gov (United States)

    Bartels, Ludwig; Ernst, Karl-Heinz

    2012-09-01

    This issue is dedicated to Karl-Heinz Rieder on the occasion of his 70th birthday. It contains contributions written by his former students and colleagues from all over the world. Experimental techniques based on free electrons, such as photoelectron spectroscopy, electron microscopy and low energy electron diffraction (LEED), were foundational to surface science. While the first revealed the band structures of materials, the second provided nanometer scale imagery and the latter elucidated the atomic scale periodicity of surfaces. All required an (ultra-)high vacuum, and LEED illustrated impressively that adsorbates, such as carbon monoxide, hydrogen or oxygen, can markedly and periodically restructure surfaces from their bulk termination, even at pressures ten orders of magnitude or more below atmospheric. Yet these techniques were not generally able to reveal atomic scale surface defects, nor could they faithfully show adsorption of light atoms such as hydrogen. Although a complete atom, helium can also be regarded as a wave with a de Broglie wavelength that allows the study of surface atomic periodicities at a delicateness and sensitivity exceeding that of electrons-based techniques. In combination, these and other techniques generated insight into the periodicity of surfaces and their vibrational properties, yet were limited to simple and periodic surface setups. All that changed with the advent of scanning tunneling microscopy (STM) roughly 30 years ago, allowing real space access to surface defects and individual adsorbates. Applied at low temperatures, not only can STM establish a height profile of surfaces, but can also perform spectroscopy and serve as an actuator capable of rearranging individual species at atomic scale resolution. The direct and intuitive manner in which STM provided access as a spectator and as an actor to the atomic scale was foundational to today's surface science and to the development of the concepts of nanoscience in general. The

  7. Surface and catalysis science in the Materials and Molecular Research Division

    International Nuclear Information System (INIS)

    1980-01-01

    Surface science studies at Lawrence Berkeley Laboratory are detailed. Subject areas include: structure of surfaces and adsorbed monolayers; reduction and oxidation of surfaces; catalytic chemistry; and structure of interfaces and thin films

  8. Fracture toughness of rough and frictional cracks emanating from a re-entrant corner

    Directory of Open Access Journals (Sweden)

    Andrea Carpinteri

    2017-07-01

    Full Text Available In mixed-mode conditions, the competing contribution of the different stress intensity factors predicts fracture initiation load as well as crack propagation direction. Commonly, mixed-mode fracture resistance is based on the assumption of smooth and frictionless cracks. However, the effect of friction and roughness cannot be neglected when mixed mode loading occurs, as in the case of a crack emanating from a re-entrant corner. In this paper, the effect of friction and roughness is evaluated through a simple saw-tooth model in a three-quarter-infinite plane (corresponding to a 90 degree re-entrant corner. The crack surfaces are assumed to be globally smooth, and roughness and friction are incorporated through a constitutive law between opposite crack surfaces. The solution is found using the distributed dislocation method, and an iterative algorithm is needed due to the non-linearity of the model. The effect of friction and roughness angle is discussed for a simple case.

  9. Evaluation of Information Leakage via Electromagnetic Emanation and Effectiveness of Tempest

    Science.gov (United States)

    Tanaka, Hidema

    It is well known that there is relationship between electromagnetic emanation and processing information in IT devices such as personal computers and smart cards. By analyzing such electromagnetic emanation, eavesdropper will be able to get some information, so it becomes a real threat of information security. In this paper, we show how to estimate amount of information that is leaked as electromagnetic emanation. We assume the space between the IT device and the receiver is a communication channel, and we define the amount of information leakage via electromagnetic emanations by its channel capacity. By some experimental results of Tempest, we show example estimations of amount of information leakage. Using the value of channel capacity, we can calculate the amount of information per pixel in the reconstructed image. And we evaluate the effectiveness of Tempest fonts generated by Gaussian method and its threshold of security.

  10. Radon Emanation from NORM-Contaminated Pipe Scale, Soil, and Sediment at Petroleum Industry Sites

    International Nuclear Information System (INIS)

    Rood, A.S.; White, G.J.

    1999-01-01

    This report describes a study of radon (Rn) emanation from pipe scale and soil samples contaminated with naturally occurring radioactive material (NORM). Samples were collected at petroleum production sites in Oklahoma, Michigan, Kentucky, and Illinois. For comparison, data are also presented from preliminary studies conducted at sites in Texas and Wyoming. All samples collected were analyzed for their Rn emanation fraction, defined as the fraction of 222Rn produced that enters the interconnected pore space within a medium contaminated with 226Ra before the 222Rn undergoes radioactive decay. This measure represents one of the important parameters that determine the overall Rn activity flux from any solid medium. The goal of this project was to determine whether Rn emanation from pipe scale and soil is similar to emanation from uranium mill tailings

  11. Suppression methods of radon emanation from phosphorus fertiliser and diatomaceous earth.

    Science.gov (United States)

    Sasaki, T; Gunji, Y; Okuda, T

    2007-01-01

    The present paper shows methods to suppress radon emanation from artificial porous materials such as phosphorous fertiliser or diatomaceous earth with a small amount of radium. The basic concept of suppression is making the radon emanation mechanism 'null', which comes from the fact that recoil is the main mechanism of radon emanation at room temperature. Nullifying may be done through removal of water in the pore volume by heating and through removal of pores by melting or filling with sulphur. These radon emanation suppression methods were tried for phosphorous fertiliser and diatomaceous earth with a small amount of radium. The melting method was the most effective of all. Sustainability of these methods was also studied. The melting method was the most sustainable. The heating method was also sustainable for diatomaceous earth in spite of a long-term immersion in water.

  12. Suppression methods of radon emanation from phosphorus fertiliser and diatomaceous earth

    International Nuclear Information System (INIS)

    Sasaki, T.; Gunji, Y.; Okuda, T.

    2007-01-01

    The present paper shows methods to suppress radon emanation from artificial porous materials such as phosphorous fertiliser or diatomaceous earth with a small amount of radium. The basic concept of suppression is making the radon emanation mechanism 'null', which comes from the fact that recoil is the main mechanism of radon emanation at room temperature. Nullifying may be done through removal of water in the pore volume by heating and through removal of pores by melting or filling with sulphur. These radon emanation suppression methods were tried for phosphorous fertiliser and diatomaceous earth with a small amount of radium. The melting method was the most effective of all. Sustainability of these methods was also studied. The melting method was the most sustainable. The heating method was also sustainable for diatomaceous earth in spite of a long-term immersion in water. (authors)

  13. Radioactivity and radon emanation fraction of the granites sampled at Misasa and Badgastein.

    Science.gov (United States)

    Sakoda, Akihiro; Hanamoto, Katsumi; Ishimori, Yuu; Nagamatsu, Tomohiro; Yamaoka, Kiyonori

    2008-05-01

    The chemical composition was analyzed and the radioactivity, radon exhalation rate and emanation fraction were measured to investigate the characteristics of the granites sampled at Misasa and Badgastein, world famous for radon therapy. The Misasa granite was probably composed of quartz, albite and microcline. The Badgastein granite was probably composed of quartz and muscovite. The radon exhalation rates and emanation fractions of the Misasa granite were much higher than those of the Badgastein granite, regardless of the (226)Ra activity concentrations.

  14. Hydrologic Science and Satellite Measurements of Surface Water (Invited)

    Science.gov (United States)

    Alsdorf, D. E.; Mognard, N. M.; Lettenmaier, D. P.

    2010-12-01

    While significant advances continue to be made for satellite measurements of surface waters, important science and application opportunities remain. Examples include the following: (1) Our current methods of measuring floodwater dynamics are either sparsely distributed or temporally inadequate. As an example, flood depths are measured by using high water marks, which capture only the peak of the flood wave, not its temporal variability. (2) Discharge is well measured at individual points along stream networks using in-situ gauges, but these do not capture within-reach hydraulic variability such as the water surface slope changes on the rising and falling limbs of flood waves. (3) Just a 1.0 mm/day error in ET over the Congo Basin translates to a 35,000 m3/s discharge error. Knowing the discharge of the Congo River and its many tributaries should significantly improve our understanding of the water balance throughout the basin. The Congo is exemplary of many other basins around the globe. (4) Arctic hydrology is punctuated by millions of unmeasured lakes. Globally, there might be as many as 30 million lakes larger than a hectare. Storage changes in these lakes are nearly unknown, but in the Arctic such changes are likely an indication of global warming. (5) Well over 100 rivers cross international boundaries, yet the sharing of water data is poor. Overcoming this helps to better manage the entire river basin while also providing a better assessment of potential water related disasters. The Surface Water and Ocean Topography (SWOT, http://swot.jpl.nasa.gov/) mission is designed to meet these needs by providing global measurements of surface water hydrodynamics. SWOT will allow estimates of discharge in rivers wider than 100m (50m goal) and storage changes in water bodies larger than 250m by 250m (and likely as small as one hectare).

  15. Designing high-temperature steels via surface science and thermodynamics

    Science.gov (United States)

    Gross, Cameron T.; Jiang, Zilin; Mathai, Allan; Chung, Yip-Wah

    2016-06-01

    Electricity in many countries such as the US and China is produced by burning fossil fuels in steam-turbine-driven power plants. The efficiency of these power plants can be improved by increasing the operating temperature of the steam generator. In this work, we adopted a combined surface science and computational thermodynamics approach to the design of high-temperature, corrosion-resistant steels for this application. The result is a low-carbon ferritic steel with nanosized transition metal monocarbide precipitates that are thermally stable, as verified by atom probe tomography. High-temperature Vickers hardness measurements demonstrated that these steels maintain their strength for extended periods at 700 °C. We hypothesize that the improved strength of these steels is derived from the semi-coherent interfaces of these thermally stable, nanosized precipitates exerting drag forces on impinging dislocations, thus maintaining strength at elevated temperatures.

  16. Variation of Radon Emanation in Workplaces as a Function of Room Parameters

    International Nuclear Information System (INIS)

    Norafatin Khalid; Amran Abdul Majid; Aznan Fazli Ismail; Muhamad Samudi Yasir; Redzuwan Yahaya; Izzaty Azani Mustafa

    2013-01-01

    Modern life style requires people to spend most of their time indoors either in a house or in the workplace. Most modern buildings are made from soil based material which may consist of low concentration of naturally occurring radioactive materials (NORM). It is known that one of the daughters of natural uranium is 226 Ra which eventually produce radon ( 222 Rn) gas. Recently, more evidence has linked lung cancer to exposure to high levels of radon and also to cigarette-smoking. Consequently, this research was conducted to study the radon emanation rates in different workplaces. The radon emanations in 27 rooms with three different dimension (54 m 3 , 210 m 3 and 351 m 3 ) and different building materials were determined for 96 hours using Sun Nuclear Radon Monitor. The radon emanations in the rooms studied were found to be in the range of 20.6 Bq m -3 hour -1 to 134.3 Bq m -3 hour -1 .The increase in humidity was found to significantly increase the radon emanation rates in the building, whereas the increase in temperature will result the decrease of radon emanation rates. In addition, the findings shows that the radon emanation rates in building were higher during the night until early in the morning which is in agreement with the findings on humidity and temperature factors. (author)

  17. Molecular metal catalysts on supports: organometallic chemistry meets surface science.

    Science.gov (United States)

    Serna, Pedro; Gates, Bruce C

    2014-08-19

    -support bonding and structure, which identify the supports as ligands with electron-donor properties that influence reactivity and catalysis. Each of the catalyst design variables has been varied independently, illustrated by mononuclear and tetranuclear iridium on zeolite HY and on MgO and by isostructural rhodium and iridium (diethylene or dicarbonyl) complexes on these supports. The data provide examples resolving the roles of the catalyst design variables and place the catalysis science on a firm foundation of organometallic chemistry linked with surface science. Supported molecular catalysts offer the advantages of characterization in the absence of solvents and with surface-science methods that do not require ultrahigh vacuum. Families of supported metal complexes have been made by replacement of ligands with others from the gas phase. Spectroscopically identified catalytic reaction intermediates help to elucidate catalyst performance and guide design. The methods are illustrated for supported complexes and clusters of rhodium, iridium, osmium, and gold used to catalyze reactions of small molecules that facilitate identification of the ligands present during catalysis: alkene dimerization and hydrogenation, H-D exchange in the reaction of H2 with D2, and CO oxidation. The approach is illustrated with the discovery of a highly active and selective MgO-supported rhodium carbonyl dimer catalyst for hydrogenation of 1,3-butadiene to give butenes.

  18. Study of radon emanation from uranium mill tailings. Relations between radon emanating power and physicochemical properties of the material; Etude de l'emanation du radon a partir de residus de traitement de minerais d'uranium. Mise en evidence de relations entre le facteur d'emanation et les caracteristiques du materiau

    Energy Technology Data Exchange (ETDEWEB)

    Pellegrini, D

    1999-07-01

    The uranium extraction from ores leads to large amounts of mill tailings still containing radionuclides, such as thorium-230 and radium-226, which generate radon-222. Without protective action, radon exposition may be high enough to cause concern for health of populations living in the vicinity of an uranium mill tailings disposal. This exposition pathway has therefore to be taken into account in the radiological impact studies. The emanating power, i.e. the part of radon atoms which escape from the solid particles, is directly involved in the radon source term evaluation. It may be determined for a given material by laboratory measurements. Emanating powers from 0.08 to 0.33 have been obtained for mill tailings from Jouac (Limousin, France), at various moisture contents. In order to reduce the relations of dependence between some of the emanation parameters, more simple phases, kaolinite and polymeric resins, have been studied. Those experiments have led us to the selection of the mechanisms and the parameters to consider for the development of an emanation modelling. The whole of the results obtained point out the radon sorption, in various proportions depending on the materials. The moisture content influence on the emanation from materials containing fine particles have been confirmed: the emanation increases with this parameter until a continuous water film surrounding the particles have been formed, and then become constant. This 'water effect' occurs in a moisture content range, which depends on the material porosity. Elsewhere, the presence of amorphous phases may led to a high radon emanation. (author)

  19. Surface physics of materials materials science and technology

    CERN Document Server

    Blakely, J M

    2013-01-01

    Surface Physics of Materials presents accounts of the physical properties of solid surfaces. The book contains selected articles that deal with research emphasizing surface properties rather than experimental techniques in the field of surface physics. Topics discussed include transport of matter at surfaces; interaction of atoms and molecules with surfaces; chemical analysis of surfaces; and adhesion and friction. Research workers, teachers and graduate students in surface physics, and materials scientist will find the book highly useful.

  20. Sea Surface Height, Absolute, Aviso, 0.25 degrees, Global, Science Quality

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Aviso Absolute Sea Surface Height is the Sea Surface Height Deviation plus the long term mean dynamic height. This is Science Quality data.

  1. 3S'83 Symposium on surface science. Contributions

    International Nuclear Information System (INIS)

    Braun, P.; Betz, G.; Husinsky, W.; Soellner, E.; Stoeri, H.; Varga, P.

    1983-01-01

    This symposium included the topics: electronic structure; ion-surface-interaction; surface structure; adsorption and reactivity; surface analysis; 60 papers were presented, only part of which pertain to INIS. (G.Q.)

  2. INTRODUCTION AND TESTING OF A SIMPLIFIED METHOD FOR THE EVALUATION OF THE RADON EMANATION.

    Science.gov (United States)

    Kabrt, F; Baumgartner, A; Stietka, M; Maringer, F J

    2017-11-01

    The radioactive noble gas radon is identified as the highest risk factor for lung cancer after smoking. The exhalation of radon from building materials can contribute to the radon indoor activity concentration. Therefore, the emanation of radon might be a crucial factor. It is defined as the release of radon from the solid soil matter into the pore space of the material. This article describes a new on-site measurement method for the emanation of radon from building materials at industrial sites. Therefore, a closed vessel with sample material and a passive radon detector inside is used to measure the integrated build-up-curve of the activity concentration. Additionally, a brief overview on existing radon emanation measurement methods is given. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Theoretical evaluation of radon emanation under a variety of conditions

    International Nuclear Information System (INIS)

    Edwards, J.C.; Bates, R.C.

    1980-01-01

    A cylindrical coordinate mathematical model to calculate 222 Rn flux and movement was developed considering 222 Rn production, decay, and diffusion in a multilayered, porous, permeable matrix. Air movement, transporting radon through the media, satisfies Darcy's law and is influenced by the air (barometric) pressure applied at the surface. Two zones of porous material have been defined, one with a 222 Rn production term (the uranium ore zone) and the other without this term to simulate shotcrete or concrete ground support. A provision is made to evaluate the effect of a pinhole in an otherwise impermeable sealant. Comparisons are made between field measurements and predicted values. Specific examples are given of 222 Rn flux from a finite ore-body model versus steady and periodic changes in barometric pressure. Also examined are 222 Rn losses through pinholes for cases of linearly varying and static barometric pressures. The results suggest factors to consider in uranium mine radon control. For example, pinholes are not a serious problem since it appears that several thousand, 2 mm diameter pinholes per square meter are required to cause a significant loss of a barrier coating's effectiveness. (author)

  4. Study of radon emanation variations in Morocco soil, correlations with seismic activities and atmospheric parameters

    International Nuclear Information System (INIS)

    Boukhal, H.; Cherkaoui, T.E.; Lferde, M.

    1994-01-01

    In order to verify the possibility of radon signal use in earthquake prediction, a study of radon emanation variation in soil was undertaken. Regular measurements have been carried out in five cities of Morocco ( Rabat, Tetouan, Ifrane, Khouribga, Berchid). The measuring method is based on the solid state nuclear track detectors technique. The good correlation between the different seismic activities and the variations of radon emanation rate in the five stations, have shown the interest of radon use in the earthquake prediction. 1 tab., 2 figs., 2 refs. (author)

  5. Impulsive radon emanation on a creeping segment of the San Andreas fault, California

    International Nuclear Information System (INIS)

    King, C.-Y.

    1984-01-01

    Radon emanation was continuously monitored for several months at two locations along a creeping segment of the San Andreas fault in central California. The recorded emanations showed several impulsive increases that lasted as much as five hours with amplitudes considerably larger than meteorologically induced diurnal variations. Some of the radon increases were accompanied or followed by earthquakes or fault-creep events. They were possibly the result of some sudden outbursts of relatively radon-rich ground gas, sometimes triggered by crustal deformation or vibration. (Auth.)

  6. 52nd colloid and surface science symposium. Proceedings volume

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, E.L. Jr.; Corbett, H.G.

    1978-05-01

    Abstracts are presented under the headings: cell/surface interactions, surface properties and reactions of catalysts, solution chemistry of surfactants, dynamic systems, microorganism/surface interactions, gas-solid interactions, biological surfaces, solid sorbents, lung surfactant and intestinal absorption, pigments, and liquid systems. (DLC)

  7. Long-term flow monitoring of submarine gas emanations

    Science.gov (United States)

    Spickenbom, K.; Faber, E.; Poggenburg, J.; Seeger, C.

    2009-04-01

    One of the Carbon Capture and Storage (CCS) strategies currently under study is the sequestration of CO2 in sub-seabed geological formations. Even after a thorough review of the geological setting, there is the possibility of leaks from the reservoirs. As part of the EU-financed project CO2ReMoVe (Research, Monitoring, Verification), which aims to develop innovative research and technologies for monitoring and verification of carbon dioxide geological storage, we are working on the development of submarine long-term gas flow monitoring systems. Technically, however, these systems are not limited to CO2 but can be used for monitoring of any free gas emission (bubbles) on the seafloor. The basic design of the gas flow sensor system was derived from former prototypes developed for monitoring CO2 and CH4 on mud volcanoes in Azerbaijan. This design was composed of a raft floating on the surface above the gas vent to collect the bubbles. Sensors for CO2 flux and concentration and electronics for data storage and transmission were mounted on the raft, together with battery-buffered solar panels for power supply. The system was modified for installation in open sea by using a buoy instead of a raft and a funnel on the seafloor to collect the gas, which is then guided above water level through a flexible tube. Besides some technical problems (condensed water in the tube, movement of the buoys due to waves leading to biased measurement of flow rates), this setup provides a cost-effective solution for shallow waters. However, a buoy interferes with ship traffic, and it is also difficult to adapt this design to greater water depths. These requirements can best be complied by a completely submersed system. To allow unattended long-term monitoring in a submarine environment, such a system has to be extremely durable. Therefore, we focussed on developing a mechanically and electrically as simple setup as possible, which has the additional advantage of low cost. The system

  8. Radium-226 content and emanating power of some timepieces manufactured in the years 1926--1951

    International Nuclear Information System (INIS)

    Keane, A.T.; Huff, D.R.

    Thirty-two radium-dial timepieces manufactured in the years 1926 to 1951 by a company in Connecticut were individually sealed in small steel cans for determination of radium-C ( 214 Bi) activity by γ-ray spectroscopy. Each can was counted within a few hours after sealing and again 5 or 6 days later; from the two observations, radium-C activities at time of sealing (nonemanating radium content) and at equilibrium (total radium content) were calculated. The mean radium-226 content of 22 pocket watches was 348 nCi (range, 159 to 606), and the mean emanating power (1-nonemanating Ra/total Ra) was 0.175 (range, 0.09 to 0.33). The mean radium-226 content of 9 wrist watches was 150 nCi (range, 54 to 449), and the mean emanating power was 0.242 (range, 0.12 to 0.34). The radium-226 content of the one small clock was 633 nCi, and its emanating power was 0.15. The concentration of radon-222 in the air of a sealed room of dimensions 3 x 3 x 3 m would be increased by about 3 pCi/l if a watch containing 400 nCi of radium-226 with an emanating power of 0.2 were left in the room for a few weeks. (U.S.)

  9. Use of emanation thermal analysis to characterize thermal reactivity of brannerite mineral

    Czech Academy of Sciences Publication Activity Database

    Balek, V.; Vance, E.R.; Zeleňák, V.; Málek, Z.; Šubrt, Jan

    2007-01-01

    Roč. 88, č. 1 (2007), s. 93-98 ISSN 1388-6150 Grant - others:GA MŠk(CZ) LA 292; GA MŠk(CZ) ME 879 Institutional research plan: CEZ:AV0Z40320502 Keywords : brannerite * emanation thermal analysis Subject RIV: CA - Inorganic Chemistry Impact factor: 1.483, year: 2007

  10. A comparison between active and passive techniques for measurements of radon emanation factors

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Coto, I. [Dept. Fisica Aplicada, University of Huelva, Huelva (Spain)], E-mail: Israel.lopez@dfa.uhu.es; Mas, J.L. [Dept. de Fisica Aplicada I, E.U.P., University of Seville, Seville (Spain); San Miguel, E.G.; Bolivar, J.P. [Dept. Fisica Aplicada, University of Huelva, Huelva (Spain); Sengupta, D. [Department of Geology and Geophysics, I.I.T. Kharagpur, West Bengal (India)

    2009-05-15

    Some radon related parameters have been determined through two different techniques (passive and active) in soil and phosphogypsum samples. Emanation factors determined through these techniques show a good agreement for soil samples while for phosphogympsum samples appear large discrepancies. In this paper, these discrepancies are analyzed and explained if non-controlled radon leakages in the passive technique are taken into account.

  11. Performance evaluation of beam emanation correction coil for neutron resonance spin echo spectrometer by simulation

    International Nuclear Information System (INIS)

    Maruyama, R.; Tasaki, S.; Hino, M.; Kawabata, Y.

    2004-01-01

    Neutron resonance spin echo (NRSE) method is a spectrometer which uses two RSF (resonance spin flipper) instead of the quietness magnetic field of Mezei type NSE spectrometer, and to measure the change in the speed of the neutron by using the phase difference accumulated in the section between a coupled of RSF in proportion to the resonance frequency of RSF. Having the feature that the magnetic field integration does not depend on the energy resolution by this substitution, and limiting the energy resolution of the NRSE spectrometer become only the beam emanations. The difference of the phase difference by the beam emanation can be corrected by introducing the magnetic field guide with the best magnetic field distribution for the emanation beam. In this research, the beam emanation correction coil for the high-resolution NRSE spectrometer is proposed, and the performance is evaluated by the simulation. As a result, the effectiveness of the correction method proposed by this research was shown. (T.Tanaka)

  12. Emanation thermal analysis study of the preparation of ruthenia-titania-based finely dispersed powders

    Czech Academy of Sciences Publication Activity Database

    Balek, V.; Mitsuhashi, T.; Zeleňák, V.; Večerníková, Eva; Šubrt, Jan; Haneda, H.; Bezdička, Petr

    2002-01-01

    Roč. 248, č. 1 (2002), s. 47-53 ISSN 0021-9797 Institutional research plan: CEZ:AV0Z4032918 Keywords : emanation thermal analysis * TiO2 * RuO2 Subject RIV: CA - Inorganic Chemistry Impact factor: 1.466, year: 2002

  13. EVALUATION OF RADON EMANATION FROM SOIL WITH VARYING MOISTURE CONTENT IN A SOIL CHAMBER

    Science.gov (United States)

    The paper describes measurements to quantitatively identify the extent to which moisture affects radon emanation and diffusive transport components of a sandy soil radon concentration gradient obtained in the EPA test chamber. The chamber (2X2X4 m long) was constructed to study t...

  14. Estimation of radon emanation coefficient for representative soils in Okinawa, Japan.

    Science.gov (United States)

    Shiroma, Y; Hosoda, M; Ishikawa, T; Sahoo, S K; Tokonami, S; Furukawa, M

    2015-11-01

    Radon ((222)Rn) emanation coefficients for the representative soils distributed in Okinawa Island, Japan, have been estimated empirically. Arithmetic means of the emanation coefficients for dry and moist conditions were calculated to be 0.19 and 0.29, respectively. In Okinawa, the soils are traditionally classified into three types, namely the dark red soils, the residual regosols and the red and yellow soils. The dark red soils have relatively high coefficients. The residual regosols and the red and yellow soils have relatively low coefficients. To investigate the variable factor of the emanation coefficients, analyses of radioactive elements and physical properties have also been performed on the soils. For the dark red soils, the contents of the fine particle and the (226)Ra are relatively higher than those for the other soils. Based on these results, it is suggested that the variation in the radon emanation coefficient is mainly regulated by the (226)Ra concentration, the particle sizes and the water contents of the soils. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. Acousto-Optic Imaging Spectrometers for Mars Surface Science

    Science.gov (United States)

    Glenar, D. A.; Blaney, D. L.

    2000-01-01

    NASA's long term plan for Mars sample collection and return requires a highly streamlined approach for spectrally characterizing a landing site, documenting the mineralogical make-up of the site and guiding the collections of samples which represent the diversity of the site. Ideally, image data should be acquired at hundreds of VIS and IR wavelengths, in order to separately distinguish numerous anticipated species, using principal component analysis and linear unmixing. Cameras with bore-sighted point spectrometers can acquire spectra of isolated scene elements, but it requires 10(exp 2) to 10(exp 2) successive motions and precise relative pointing knowledge in order to create a single data cube which qualifies as a spectral map. These and other competing science objectives have to be accomplished within very short lander/rover operational lifetime (a few sols). True, 2-D imaging spectroscopy greatly speeds up the data acquisition process, since the spectra of all pixels in the scene are collected at once. This task can be accomplished with cameras that use electronically tunable acousto-optic tunable filters (AOTFs) as the optical tuning element. AOTFs made from TeO2 are now a mature technology, and operate at wavelengths from near-UV to about 5 microns. Because of incremental improvements in the last few years, present generation devices are rugged, radiation-hard and operate at temperatures down to at least 150K so they can be safely integrated into the ambient temperature optics of in-situ instruments such as planetary or small-body landers. They have been used for ground-based astronomy, and were also baselined for the ST-4 Champollion IR comet lander experiment (CIRCLE), prior to cancellation of the ST-4 mission last year. AIMS (for Acousto-optic Imaging spectrometer), is a prototype lander instrument which is being built at GSFC with support by the NASA OSS Advanced Technologies and Mission Studies, Mars Instrument Definition and Development Program (MIDP

  16. Science synergism study for EOS on evolution of desert surfaces

    Science.gov (United States)

    Farr, Tom G.

    1987-01-01

    The effectiveness of EOS data as a basis for the study of desert surfaces' evolution is presently evaluated for both long and short term geomorphic evolution. Attention is given to the usefulness of such sensor systems planned for EOS as MODIS for regional vegetation distribution/variability monitoring, HIRIS for visible-near IR observations, TIMS for lithological identification, HMMR and SSMI for soil characteristics, LASA for atmospheric profiles, SAR for surface roughness, ALT for two-dimensional topography, ACR for the calibration of imaging sensors, and ERBE for climate modeling and regional surface albedo variation determinations.

  17. Surface science studies on titania for solar fuel applications

    Science.gov (United States)

    Hadsell, Courtney Sara Mathews

    Titanium dioxide (titania) is a well-studied material for various applications including but not limited to, paint, sunscreen, pharmaceuticals and solar cell applications (photocatalysis.) It can be found in three main crystal forms; rutile, anatase, and brookite and this work will focus on the anatase form which has been heavily studied for its potential in dye sensitized solar cells (DSSCs.) I propose that aqueous and photo dye stability can be improved by taking special care to the exposed surface of anatase. Additionally, the theoretical maximum open circuit voltage of a DSSC is dependent upon which surface is exposed to the electrolyte. Previous works in this area have not been rigorous with respect to the surface and morphology of titania being used. Standard synthesis techniques of anatase lead to a crystal that generally has 94% of the titania (101) surface exposed, and the other 6% is the higher energy (001) surface. The (101) surface has 5 & 6-fold coordinated titania whereas the (001) surface only has 5-fold (under) coordinated titania. This under-coordination leads to enhanced reactivity of the (001) surface which has been demonstrated by dissassociative adsorption of water, and catalysis applications. Much theoretical work has focused on the minority (001) surface because up until recently synthesizing anatase with enhanced exposure of the (001) surface has been difficult. The initial materials for this study will be multilayer titania nanotubes (TiNTs) and nanosheets (TiNS) which have been previously characterized by my predecessor. The TiNTs and TiNS have 100% exposed (001)-like surface. Both of these materials show enhanced stability of phosphonated dye binding as compared to the current standard of anatase nanoparticles (NPs) however, due to their limited thermal stability the potential of incorporating the TiNTs and TiNSs into devices has been eliminated in this study. To overcome the device limitations I will synthesis a novel titania nanotile

  18. Emanation of tritiated water from disposal sites at Los Alamos, New Mexico

    International Nuclear Information System (INIS)

    Abeele, W.V.

    1982-01-01

    The level of contamination induced by the presence of tritiated water (HTO) on the Bandelier tuff near Los Alamos, New Mexico has been seen to decrease vertically and horizontally at the same rate. This decrease in radioactivity with distance from the source has been measured around three different disposal shafts and found to be somewhat slower than the decrease in emanation rate with distance from the source. Physical factors, suspected of influencing HTO emanation, were entered as independent variables in a regression equation including measurements taken over a 14 month period. The physical variables studied were of thermal, hydrological, and meteorological origin or a combination of the above. Only four variables were retained as significant although they explained only 71% of the variation in the HTO flux

  19. Soil-gas Radon Emanation in Active Hydrothermal Areas at Lassen Volcanic Center, Northern California

    Science.gov (United States)

    Chan, T.; Ararso, I.; Yanez, F.; Swamy, V.; Brandon, J.; Bartelt, E.; Cuff, K. E.

    2004-12-01

    Located along the Southern Cascade Range in Northern California, the Lassen Volcanic Center is one of the youngest major Cascade volcanoes. Aside from Mount Saint Helens, Lassen is the only Cascade volcano to erupt in the 20th century. In an effort to assess outgassing in and around Lassen, and to provide information that will contribute to a better understanding of its hydrothermal system, we have conducted detailed soil-gas radon emanation surveys in several active hydrothermal areas, which possess bubbling mud pots, steaming fumaroles, and boiling hot springs. Dozens of measurements have been made in each of these areas, which are then used to create maps that indicate areas of high outgassing. These maps are then employed to assess the degree to which volcanic and other gases are currently being emitted at Lassen, as well as to investigate patterns associated with these emissions. The mean of measurements made in a specific survey area is considered to represent the average radon flux in that area. Individual values exceeding the mean plus one standard deviation are considered to represent anomalously high emanation, while values less than the mean minus one standard deviation represent anomalously low emanation. Based on preliminary analysis of data collected so far, significant outgassing occurs along well-defined, northwest-southeast trending elongate zones in several areas. Values obtained in these zones are as much as three times background radon flux. These zones are believed to contain fractures that act as pathways for migrating gases. The results of studies conducted thus far indicate that further emanation surveys will generate very useful information.

  20. Electric field penetration into the ionosphere in the presence of anomalous radon emanation

    Science.gov (United States)

    Xu, Tong; Zhang, Hanlu; Hu, Yanli; Wu, Jian

    2015-06-01

    The scientists came to consensus that electric field driven mechanism is more probable to explain ionospheric anomalies before earthquakes than the acoustic-driven mechanism (Pulients and Davidenko, 2014), and it is essential to understand how a vertical electric field from the ground penetrates into the ionosphere. Anomalous radon emanation in the epicentral area is believed to change the atmospheric electrical conditions. Considering the effect of radon emanation on atmospheric conductivity, the electric potential equation is established and solved numerically in the presence of a vertical electric field of 1 kV/m on the ground. The results show that radon emanation can strengthen atmospheric conductivity, as a consequence, the resulting electric field is increased by about 60% in the daytime ionosphere. However, the resulting electric field in the ionosphere is very weak (only about 0.3 μV/m), which implies that the penetration of vertical electric field of 1 kV/m in the seismic area is unlikely to produce daytime ionospheric anomalies before earthquakes.

  1. Study of the emanation levels of 222Rn present in Naturally Occurring Radioactive Materials - NORM

    International Nuclear Information System (INIS)

    Miranda, Marcia Valeria de Fatima da Encarnacao Sa

    2009-01-01

    The presence of Naturally Occurring Radioactive Material (NORM), contaminating oil and gas facilities, is a common fact in the petroleum industry, and can be severe enough to expose the workers to elevated levels of radiation. Thus, contaminated residues need to be segregated but, this is still a problem without a satisfactory solution. Currently, the most practical and economic option for discarding this material is to stock it in areas of the facility whose access is controlled. Certain equipment used in the petroleum industry has scale and sludge that could be associated to important levels of radioactivity. Typically, the scale is a mixture of carbonate and sulphate minerals, such as barite (BaSO 4 ), that easily incorporates 226 Ra and 228 Ra in its structures. The objective of this work was to measure the emanations of the radon present in these NORM samples, via diffusion chambers containing a nuclear track detector (CR-39). The images of particle alpha tracks emanated by 222 Rn registered on CR-39 were observed with a Nikon E400 optic microscope and captured by a Nikon Coolpix digital camera and then stored in a database, to later count the tracks using the computational program, Image Pro plus. Being that the emanation rate of 222 Rn was proportional to the number of these tracks the methodology permitted the comparison of contamination levels of the analyzed samples. (author)

  2. Density functional theory in surface science and heterogeneous catalysis

    DEFF Research Database (Denmark)

    Nørskov, Jens Kehlet; Scheffler, M.; Toulhoat, H.

    2006-01-01

    Solid surfaces are used extensively as catalysts throughout the chemical industry, in the energy sector, and in environmental protection. Recently, density functional theory has started providing new insight into the atomic-scale mechanisms of heterogeneous catalysis, helping to interpret the large...... amount of experimental data gathered during the last decades. This article shows how density functional theory can be used to describe the state of the surface during reactions and the rate of catalytic reactions. It will also show how we are beginning to understand the variation in catalytic activity...

  3. Mineral Surface Reactivity in teaching of Science Materials

    Science.gov (United States)

    Del Hoyo Martínez, Carmen

    2013-04-01

    In the last fifty years, science materials issues has required the study of air pollution, water and soil to prevent and remedy the adverse effects of waste originating from anthropogenic activity and the development of new energies and new materials. The teaching of this discipline has been marked by lectures on general lines, materials, disciplines, who explained biased objects of reality, but often forgot the task of reconstruction and integration of such visions. Moving from that model, otherwise quite static, to a dynamic relational model, would in our view, a real revolution in education. This means taking a systematic approach to complex both in interpreting reality and in favor when learning. Children relationships are as important or more than single objects, and it is to discover fundamental organizational principles of phenomena we seek to interpret or in other words, find the pattern that connects. Thus, we must work on relationships and also take into account the relation between the observer and the observed. Educate about relationships means that studies should always be considered within a framework of probabilities, not absolute certainties. This model of systemic thinking, dealing with complexity, is a possibility to bring coherence to our educational work, because the complexity is not taught, complexity is live, so that complex thinking is extended (and fed) in a form educate complex. It is the task of teaching to help people move from level to level of decision reviews. This means that systems thinking should be extended in a local action, action that engages the individual and the environment. Science Materials has emerged as a discipline of free choice for pupils attending chemical engineering which has been assigned 6.0 credits. The chemical engineer's professional profile within the current framework is defined as a professional knowledge as a specialization technical / functional, working in a learning organization and the formation of

  4. The influence of lithology on surface water sources | Science ...

    Science.gov (United States)

    Understanding the temporal and spatial variability of surface water sources within a basin is vital to our ability to manage the impacts of climate variability and land cover change. Water stable isotopes can be used as a tool to determine geographic and seasonal sources of water at the basin scale. Previous studies in the Coastal Range of Oregon reported that the variation in the isotopic signatures of surface water does not conform to the commonly observed “rainout effect”, which exhibits a trend of increasing isotopic depletion with rising elevation. The primary purpose of this research is to investigate the mechanisms governing seasonal and spatial variations in the isotopic signature of surface waters within the Marys River Basin, located in the leeward side of the Oregon Coastal Range. Surface water and precipitation samples were collected every 2-3 weeks for isotopic analysis of δ18O and δ2H for one year. Results indicate a significant difference in isotopic signature between watersheds underlain by basalt and sandstone. The degree of separation was the most distinct during the summer when low flows reflect deeper groundwater sources, whereas isotopic signatures during the rainy season (fall and winter) showed a greater degree of similarity between the two lithologies. This indicates that baseflow within streams drained by sandstone versus basalt is being supplied from two distinctly separate water sources. In addition, Marys River flow at the outle

  5. Thermochemical Surface Engineering: A Playground for Science and Innovation

    DEFF Research Database (Denmark)

    Christiansen, Thomas Lundin; Dahl, Kristian Vinter; Jellesen, Morten Stendahl

    2017-01-01

    Surface engineering by thermochemical processing is the intentional change of the composition of a material at elevated temperature with the purpose to improve materials performance. In thermochemical processing components from the starting material are essential in the development of the phases ...... hardening of titanium alloys, as well as thermo-reactive diffusion for extreme wear resistance...

  6. Surface science studies of model fuel cell electrocatalysts

    Science.gov (United States)

    Marković, N. M.; Ross, P. N.

    2002-04-01

    The purpose of this review is to discuss progress in the understanding of electrocatalytic reactions through the study of model systems with surface spectroscopies. Pure metal single crystals and well-characterized bulk alloys have been used quite successfully as models for real (commercial) electrocatalysts. Given the sheer volume of all work in electrocatalysis that is on fuel cell reactions, we will focus on electrocatalysts for fuel cells. Since Pt is the model fuel cell electrocatalyst, we will focus entirely on studies of pure Pt and Pt bimetallic alloys. The electrode reactions discussed include hydrogen oxidation/evolution, oxygen reduction, and the electrooxidation of carbon monoxide, formic acid, and methanol. Surface spectroscopies emphasized are FTIR, STM/AFM and surface X-ray scattering (SXS). The discussion focuses on the relation between the energetics of adsorption of intermediates and the reaction pathway and kinetics, and how the energetics and kinetics relate to the extrinsic properties of the model system, e.g. surface structure and/or composition. Finally, we conclude by discussing the limitations that are reached by using pure metal single crystals and well-characterized bulk alloys as models for real catalysts, and suggest some directions for developing more realistic systems.

  7. Surface Chemistry of CWAs for Decon Enabling Sciences

    Science.gov (United States)

    2014-11-04

    Ultraviolet and Visible Photochemistry of Methanol at 3D Mesoporous Networks: TiO, The Journal of Physical Chemistry C, (07 2013): 15035. doi...A for none) Presentations since most recent interim report for this project: " Photochemistry of Methanol at 3-D Networked Aerogels of TiO2 and...evaporation • Studied the uptake, thermal, and photochemistry of agent simulants on TiO2 surfaces • Initiated experiments on the uptake and

  8. Surface science. Adhesion and friction in mesoscopic graphite contacts.

    Science.gov (United States)

    Koren, Elad; Lörtscher, Emanuel; Rawlings, Colin; Knoll, Armin W; Duerig, Urs

    2015-05-08

    The weak interlayer binding in two-dimensional layered materials such as graphite gives rise to poorly understood low-friction characteristics. Accurate measurements of the adhesion forces governing the overall mechanical stability have also remained elusive. We report on the direct mechanical measurement of line tension and friction forces acting in sheared mesoscale graphite structures. We show that the friction is fundamentally stochastic in nature and is attributable to the interaction between the incommensurate interface lattices. We also measured an adhesion energy of 0.227 ± 0.005 joules per square meter, in excellent agreement with theoretical models. In addition, bistable all-mechanical memory cell structures and rotational bearings have been realized by exploiting position locking, which is provided solely by the adhesion energy. Copyright © 2015, American Association for the Advancement of Science.

  9. Building Surface Science Capacity to Serve the Automobile Industry in Southeastern Michigan, final report

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Weidian

    2013-09-27

    This project, “Building Surface Science Capacity to Serve the Automobile Industry in Southeastern Michigan” was carried out in two phases: (1) the 2009 – 2012 renovation of space in the new EMU Science Complex, which included the Surface Science Laboratory (SSL), a very vigorous research lab at EMU that carries on a variety of research projects to serve the auto and other industries in Michigan; and (2) the 2013 purchase of several pieces of equipment to further enhance the research capability of the SSL. The funding granted by the DoE was proposed to “renovate the space in the Science Complex to include SSL and purchase equipment for tribological and electrochemical impedance measurements in the lab, thus SSL will serve the auto and other industries in Michigan better.” We believe we have fully accomplished the mission.

  10. Intense positron beam and its application to surface science

    International Nuclear Information System (INIS)

    Ito, Y.; Hirose, M.; Kanazawa, I.; Sueoka, O.; Takamura, S.; Okada, S.

    1992-01-01

    Intense pulsed slow positron beam has been produced using the 100 MeV electron LINAC of JAERI · Tokai. In order to use the beam for surface studies such as positron diffraction and positron microscopy, it was transferred from the solenoid magnetic field to field free region and then was brightness-enhanced. The beam size was reduced from 10 mmφ (in the magnetic field) to 0.5 mmφ after two stages of re-moderation. Using the intense brightness-enhanced positron beam we have observed for the first time RHEPD (Reflection High-Energy Positron Diffraction) patterns. A design of re-emission positron microscopy is also described. (author)

  11. Radon and thoron emanation measurements and the effect of ground water

    International Nuclear Information System (INIS)

    Carriveau, G.W.; Harbottle, G.

    1980-01-01

    In the past, corrections for annual dose rate calculations have used a qualitative approach to the effect of ground water saturation and radon and thoron loss. An example is presented of how this correction can now be precisely determined using natural gamma-ray activities to determine the amount of emanation from ceramic sherds and soil, both in a dry state and saturated with ground water. The experimental data also provide information concerning disequilibria in 234 Th and 226 Ra regions of the decay series. Additionally, approximate values of uranium and thorium concentrations (sufficiently accurate for authenticity work) are provided

  12. Emanation thermal analysis. Application in solid state chemistry, analytical chemistry and engineering

    International Nuclear Information System (INIS)

    Balek, V.; Tel'deshi, Yu.

    1986-01-01

    Voluminous material on application of emenation thermal analysis for investigation of solids is systematized. General concepts and historical review of development of the method are given. Methods of introduction of inert gases into solids are considered. Theoretical aspects of inert gas evolution from solids labelled by radioactive gas or its maternal isotope are stated. The methods for measuring inert gases are considered. The possibilities, limitations and perspectives of development of radiometric emanation methods for the solution of various problems of analytical chemistry and thechnology are discussed

  13. Surface science study of selective ethylene epoxidation catalyzed by the Ag(110) surface: Structural sensitivity

    International Nuclear Information System (INIS)

    Campbell, C.T.

    1984-01-01

    The selective oxidation of ethylene to ethylene epoxide (C 2 H 4 +1/2O 2 →C 2 H 4 O) over Ag is the simplest example of kinetically controlled, selective heterogeneous catalysis. We have studied the steady-state kinetics and selectivity of this reaction for the first time on a clean, well-characterized Ag(110) surface by using a special apparatus which allows rapid (approx.20 s) transfer between a high-pressure catalytic microreactor and an ultrahigh vacuum surface analysis (AES, XPS, LEED, TDS) chamber. The effects of temperature and reactant pressures upon the rate and selectivity are virtually identical on Ag(110) and supported, high surface area Ag catalysts. The absolute specific rate (per Ag surface atom) is, however, some 100-fold higher for Ag(110) than for high surface area catalysts. This is related to the well-known structural sensitivity of this reaction. It is postulated that a small percentage of (110) planes (or [110]-like sites) are responsible for most of the catalytic activity of high surface area catalysts. The high activity of the (110) plane is attributed to its high sticking probability for dissociative oxygen adsorption, since the rate of ethylene epoxidation is shown in a related work [Ref. 1: C. T. Campbell and M. T. Paffett, Surf. Sci. (in press)] to be proportional to the coverage of atomically adsorbed oxygen at constant temperature and ethylene pressure

  14. Calibration of a degassing-emanation line for 222Rn determination in seawater samples

    International Nuclear Information System (INIS)

    Farias, Luciana Aparecida

    2002-01-01

    The purpose of this study is to calibrate a degassing-emanation line and to determine 222 Rn and 226 Ra activity concentrations in seawater samples. This methodology, also called Lucas method, consists in the extraction of radon (originally dissolved in seawater), collection of the gas in a liquid nitrogen cold trap and transfer from the trap to an alpha scintillation cell. Total extraction efficiencies of the 4 degassing-emanation systems were determined by measuring 226 Ra reference solutions. The efficiencies obtained for these 4 systems varied from 21 % to 62%. This work also presents preliminary results of a study carried out in a series of small embayements of Ubatuba, Sao Paulo State-Brazil: Flamengo Bay, Fortaleza Bay, Mar Virado Bay and Ubatuba Bay. Concentration of Rn in excess varied from 0,011 to 0,317 Bq/L for Flamengo Bay, from 0,009 to 0,130 Bq/L for Fortaleza Bay, from 0,018 to 0,050 Bq/L for Mar Virado Bay and from 0,004 to 0,120 Bq/L for Ubatuba Bay. The results obtained for the concentration of 222 Rn in excess in a transect at Flamengo Bay varied from 0,002 to 0,036 Bq/L. Higher concentrations of 222 Rn in excess were obtained in Flamengo Bay, Fortaleza Bay and Ubatuba bay. It was also observed that the concentration of 222 Rn in excess increases with depth, as expected. (author)

  15. Divine Emanation As Cosmic Origin: Ibn Sînâ and His Critics

    Directory of Open Access Journals (Sweden)

    Syamsuddin Arif

    2012-11-01

    Full Text Available The question of cosmic beginning has always attracted considerable attention from serious thinkers past and present. Among many contesting theories that have emerged, that of emanation was appropriated by Muslim philosophers like Ibn Sînâ in order to reconcile the Aristotelian doctrine of the eternity of matter with the teaching of al-Qur’ân on the One Creator-God. According to this theory, the universe, which comprises a multitude of  entities, is generated from a transcendent Being, the One, that is unitary, through the medium of  a hierarchy of  immaterial substances. While the ultimate source is undiminished, the beings which are emanated are progressively less perfect as they are further removed from the first principle. The process is conceived as being atemporal and often compared to the efflux of light from a luminous body, or to water flowing from a spring. This metaphysical theory has enabled Ibn Sînâ to solve the vexed problem: given an eternally existing world and one eternally existing God, how can the two necessarily co-exist without having the perfect, simple unity of God destroyed by contact with the multiplicity of material things? The following essay delineates and evaluates both Ibn Sînâ’s arguments as well as the counter-arguments of  his critics.

  16. EDITORIAL: Three decades of scanning tunnelling microscopy that changed the course of surface science Three decades of scanning tunnelling microscopy that changed the course of surface science

    Science.gov (United States)

    Ramachandra Rao, M. S.; Margaritondo, Giorgio

    2011-11-01

    Three decades ago, with a tiny tip of platinum, the scientific world saw the real space imaging of single atoms with unprecedented spatial resolution. This signalled the birth of one of the most versatile surface probes, based on the physics of quantum mechanical tunnelling: the scanning tunnelling microscope (STM). Invented in 1981 by Gerd Binnig and Heinrich Rohrer of IBM, Zurich, it led to their award of the 1986 Nobel Prize. Atoms, once speculated to be abstract entities used by theoreticians for mere calculations, can be seen to exist for real with the nano-eye of an STM tip that also gives real-space images of molecules and adsorbed complexes on surfaces. From a very fundamental perspective, the STM changed the course of surface science and engineering. STM also emerged as a powerful tool to study various fundamental phenomena relevant to the properties of surfaces in technological applications such as tribology, medical implants, catalysis, sensors and biology—besides elucidating the importance of local bonding geometries and defects, non-periodic structures and the co-existence of nano-scale phases. Atom-level probing, once considered a dream, has seen the light with the evolution of STM. An important off-shoot of STM was the atomic force microscope (AFM) for surface mapping of insulating samples. Then followed the development of a flurry of techniques under the general name of scanning probe microscopy (SPM). These techniques (STM, AFM, MFM, PFM etc) designed for atomic-scale-resolution imaging and spectroscopy, have led to brand new developments in surface analysis. All of these novel methods enabled researchers in recent years to image and analyse complex surfaces on microscopic and nanoscopic scales. All of them utilize a small probe for sensing the surface. The invention of AFM by Gerd Binnig, Calvin Quate and Christopher Gerber opened up new opportunities for characterization of a variety of materials, and various industrial applications could be

  17. New Material Development for Surface Layer and Surface Technology in Tribology Science to Improve Energy Efficiency

    Science.gov (United States)

    Ismail, R.; Tauviqirrahman, M.; Jamari, Jamari; Schipper, D. J.

    2009-09-01

    This paper reviews the development of new material and surface technology in tribology and its contribution to energy efficiency. Two examples of the economic benefits, resulted from the optimum tribology in the transportation sector and the manufacturing industry are discussed. The new materials are proposed to modify the surface property by laminating the bulk material with thin layer/coating. Under a suitable condition, the thin layer on a surface can provide a combination of good wear, a low friction and corrosion resistance for the mechanical components. The innovation in layer technology results molybdenum disulfide (MoS2), diamond like carbon (DLC), cubic boron nitride (CBN) and diamond which perform satisfactory outcome. The application of the metallic coatings to carbon fibre reinforced polymer matrix composites (CFRP) has the capacity to provide considerable weight and power savings for many engineering components. The green material for lubricant and additives such as the use of sunflower oil which possesses good oxidation resistance and the use of mallee leaves as bio-degradable solvent are used to answer the demand of the environmentally friendly material with good performance. The tribology research implementation for energy efficiency also touches the simple things around us such as: erasing the laser-print in a paper with different abrasion techniques. For the technology in the engineering surface, the consideration for generating the suitable surface of the components in running-in period has been discussed in order to prolong the components life and reduce the machine downtime. The conclusion, tribology can result in reducing manufacturing time, reducing the maintenance requirements, prolonging the service interval, improving durability, reliability and mechanical components life, and reducing harmful exhaust emission and waste. All of these advantages will increase the energy efficiency and the economic benefits.

  18. Mars' surface radiation environment measured with the Mars science laboratory's curiosity rover

    NARCIS (Netherlands)

    Hassler, D.M.; Zeitlin, C.; Wimmer-Schweingruber, R.F.; Ehresmann, B.; Rafkin, S.; Eigenbrode, J.L.; Brinza, D.E.; Weigle, G.; Böttcher, S.; Böhm, E.; Burmeister, S.; Guo, J.; Köhler, J.; Martin, C.; Reitz, G.; Cucinotta, F.A.; Kim, M.-H.; Grinspoon, D.; Bullock, M.A.; Posner, A.; Gómez-Elvira, J.; Vasavada, A.; Grotzinger, J.P.; MSL Science Team, the|info:eu-repo/dai/nl/292012217

    2014-01-01

    The Radiation Assessment Detector (RAD) on the Mars Science Laboratory’s Curiosity rover began making detailed measurements of the cosmic ray and energetic particle radiation environment on the surface of Mars on 7 August 2012. We report and discuss measurements of the absorbed dose and dose

  19. Earth System Science at NASA: Teleconnections Between Sea Surface Temperature and Epidemics in Africa

    Science.gov (United States)

    Meeson, Blanche W.

    2000-01-01

    The research carried out in the Earth Sciences in NASA and at NASA's Goddard Space Flight Center will be the focus of the presentations. In addition, one research project that links sea surface temperature to epidemics in Africa will be highlighted. At GSFC research interests span the full breath of disciplines in Earth Science. Branches and research groups focus on areas as diverse as planetary geomagnetics and atmospheric chemistry. These organizations focus on atmospheric sciences (atmospheric chemistry, climate and radiation, regional processes, atmospheric modeling), hydrological sciences (snow, ice, oceans, and seasonal-to-interannual prediction), terrestrial physics (geology, terrestrial biology, land-atmosphere interactions, geophysics), climate modeling (global warming, greenhouse gases, climate change), on sensor development especially using lidar and microwave technologies, and on information technologies, that enable support of scientific and technical research.

  20. Near-Surface Geophysics: Advancing Earth Science Through Advances in Imaging

    Science.gov (United States)

    Knight, R.

    2006-05-01

    The near-surface of Earth (the top ~100 m) is the region that supports human infrastructure, provides water and mineral resources, and is the interface between solid Earth and atmosphere for many of the biogeochemical cycles that sustain life. Developing an understanding of the processes and properties that occur here is essential for advancing our understanding of many parts of the Earth system. Yet our ability to study, sample, or probe this zone is remarkably primitive. Many investigations rely on drilling, trenching, and direct sampling. But given the pervasive spatial heterogeneity of the region, such methods yield information that is inadequate in terms of the spatial extent and density of sampling. As a result, the Earth science community is turning to geophysical imaging. The area of research that is focused on developing and applying geophysical methods to study this region of Earth is referred to as near-surface geophysics. Near-surface geophysics, as an area of research, includes many types of research, and many types of researchers. Some researchers are drawn to near-surface geophysics due to an interest in specific properties, processes, or applications, which can range from applied to basic science. As examples, near-surface geophysical methods are used for resource exploration and extraction, for the characterization of contaminated sites, for the assessment and design of built infrastructure; and to address scientific questions in neotectonics, volcanology, glaciology, hydrology, sedimentology, archaeology, geochemistry and biogeochemistry. Other researchers are drawn to near-surface geophysics due to an interest in the science of imaging as the driving scientific question. Advances in imaging require investigating the ways in which physical sensors can (or cannot) capture the complexity of a natural system, determining how best to quantify and enhance the spatial and temporal resolution of a measurement, developing new methods for the inversion of

  1. Estimation of increased regional income that emanates from economically justified road construction projects

    Directory of Open Access Journals (Sweden)

    W. J. Pienaar

    2005-09-01

    Full Text Available This article identifies the possible development benefits than can emanate from economically justified road construction projects. It shows how the once-off increase in regional income resulting from investment in road construction projects, and the recurring additional regional income resulting from the use of new or improved roads can be estimated. The difference is shown that exists between a cost-benefit analysis (to determine how economically justified a project is and a regional economic income analysis (to estimate the general economic benefits that will be developed by investment in and usage of a road. Procedures are proposed through which the once-off and recurring increases in regional income can be estimated by using multiplier and accelerator analyses respectively. Finally guidelines are supplied on the appropriate usage of input variables in the calculation of the regional income multiplier.

  2. Communication: Systematic elimination of Stokes divergences emanating from complex phase space caustics

    Science.gov (United States)

    Koch, Werner; Tannor, David J.

    2018-03-01

    Stokes phenomenon refers to the fact that an asymptotic expansion of complex functions can differ in different regions of the complex plane, and that beyond the so-called Stokes lines the expansion has an unphysical divergence. An important special case is when the Stokes lines emanate from phase space caustics of a complex trajectory manifold. In this case, symmetry determines that to second order there is a double coverage of the space, one portion of which is unphysical. Building on the seminal but laconic findings of Adachi, we show that the deviation from second order can be used to rigorously determine the Stokes lines and therefore the region of the space that should be removed. The method has applications to wavepacket reconstruction from complex valued classical trajectories. With a rigorous method in hand for removing unphysical divergences, we demonstrate excellent wavepacket reconstruction for the Morse, Quartic, Coulomb, and Eckart systems.

  3. Radiometric maps of Israel - Partial contribution to the understanding of potential radon emanations

    International Nuclear Information System (INIS)

    Vulkan, U.; Shirav, M.

    1997-01-01

    An airborne radiometric survey over parts of Israel was carried out in 1981. The system was comprised from 10 Nal 4 inch x 4 inch x 16 inch detectors, arranged in 4,4 and 2 sensors, with total volume of 1560 inch 3 , and one 4 inch x 4 inch x 16 inch uplooking Nal detector. Flight nominal height was 400 feet. It was found that the Mount Scopus Group (of Senonian origin) is the main source for high uranium - phosphorite rocks of this group contain up to 150 ppm U. Comparing the eU radiometric map with a map of potential radon emanation from rock units, reveals a fair correlation - high radon emanation usually follow the distribution of the Mount Scopus Group in Israel. The correlation between the two maps is excellent over arid terrain where soil cover is missing, whereas over semi-arid - humid areas (western and northern Israel), where soil and cultivation covers are developed, the eU levels over Mount Scopus Group's outcrops are much lower due to absorption of the radiation, and do not depict the full radon potential. Detailed mapping of radon hazards usually exhibit poor correlation between airborne eU data and direct pore radon measurements, even in arid terrain. This phenomenon is attributed to the fact that a radon ''source rock'' (e.g. phosphorite) could be covered with a few up to some tenths of meters of uranium-barren rock. About 0.5 meter cover is enough to absorb all radiation, causing very low airborne eU readings, while the radon free way in this rock is about 10 meters, yielding high pore radon levels when directly measured

  4. The human volatilome: volatile organic compounds (VOCs) in exhaled breath, skin emanations, urine, feces and saliva.

    Science.gov (United States)

    Amann, Anton; Costello, Ben de Lacy; Miekisch, Wolfram; Schubert, Jochen; Buszewski, Bogusław; Pleil, Joachim; Ratcliffe, Norman; Risby, Terence

    2014-09-01

    Breath analysis is a young field of research with its roots in antiquity. Antoine Lavoisier discovered carbon dioxide in exhaled breath during the period 1777-1783, Wilhelm (Vilém) Petters discovered acetone in breath in 1857 and Johannes Müller reported the first quantitative measurements of acetone in 1898. A recent review reported 1765 volatile compounds appearing in exhaled breath, skin emanations, urine, saliva, human breast milk, blood and feces. For a large number of compounds, real-time analysis of exhaled breath or skin emanations has been performed, e.g., during exertion of effort on a stationary bicycle or during sleep. Volatile compounds in exhaled breath, which record historical exposure, are called the 'exposome'. Changes in biogenic volatile organic compound concentrations can be used to mirror metabolic or (patho)physiological processes in the whole body or blood concentrations of drugs (e.g. propofol) in clinical settings-even during artificial ventilation or during surgery. Also compounds released by bacterial strains like Pseudomonas aeruginosa or Streptococcus pneumonia could be very interesting. Methyl methacrylate (CAS 80-62-6), for example, was observed in the headspace of Streptococcus pneumonia in concentrations up to 1420 ppb. Fecal volatiles have been implicated in differentiating certain infectious bowel diseases such as Clostridium difficile, Campylobacter, Salmonella and Cholera. They have also been used to differentiate other non-infectious conditions such as irritable bowel syndrome and inflammatory bowel disease. In addition, alterations in urine volatiles have been used to detect urinary tract infections, bladder, prostate and other cancers. Peroxidation of lipids and other biomolecules by reactive oxygen species produce volatile compounds like ethane and 1-pentane. Noninvasive detection and therapeutic monitoring of oxidative stress would be highly desirable in autoimmunological, neurological, inflammatory diseases and cancer

  5. Influence of meteorological parameters on the soil radon (Rn222) emanation in Kutch, Gujarat, India.

    Science.gov (United States)

    Sahoo, Sushanta Ku; Katlamudi, Madhusudhanarao; Shaji, Jerin P; Murali Krishna, K S; Udaya Lakshmi, G

    2018-02-02

    The soil radon (Rn 222 ) and thoron (Rn 220 ) concentrations recorded at Badargadh and Desalpar observatories in the Kutch region of Gujarat, India, have been analyzed to study the sources of the radon emissions, earthquake precursors, and the influence of meteorological parameters on radon emission. Radon and meteorological parameters were recorded using Radon Monitor RMT 1688-2 at these two stations. We used the radon data during February 21, 2011 to June 8, 2011, for Badargadh and March 2, 2011 to May 19, 2011, for the Desalpar station with a sampling interval of 10 min. It is observed that the radon concentrations at Desalpar varies between 781 and 4320 Bq m -3 with an average value of 2499 Bq m -3 , whereas thoron varies between 191 and 2017 Bq m -3 with an average value of 1433.69 Bq m -3 . The radon concentration at Badargadh varies between 264 and 2221 Bq m -3 with an average value of 1135.4 Bq m -3 , whereas thoron varies between 97 and 556 Bq m -3 . To understand how the meteorological parameters influence radon emanation, the radon and other meteorological parameters were correlated with linear regression analysis. Here, it was observed that radon and temperature are negatively correlated whereas radon and other two parameters, i.e., humidity and pressure are positively correlated. The cross correlogram also ascertains similar relationships between radon and other parameters. Further, the ratio between radon and thoron has been analyzed to determine the deep or shallow source of the radon emanation in the study area. These results revealed that the ratio radon/thoron enhanced during this period which indicates the deeper source contribution is prominent. Incidentally, all the local earthquakes occurred with a focal depth of 18-25 km at the lower crust in this region. We observed the rise in the concentrations of radon and the ratio radon/thoron at Badargadh station before the occurrence of the local earthquakes on 29th March 2011 (M 3

  6. Interim report to the Northern Ecosystem Initiative from the Northern Ecological Monitoring and Assessment Network (EMAN-North)

    International Nuclear Information System (INIS)

    Wakelyn, L.; Eamer, J.

    2001-01-01

    The Northern Ecological Monitoring and Assessment Network (EMAN-North) has received funding for a proposal submitted to the Northern Ecosystems Initiative (NEI) in January 2001. EMAN-North is a network that coordinates ecological monitoring in northern Canada. Its geographic scope comprises 40 per cent of the geographic area of Canada, including Yukon, Northwest Territories and Nunavut, and an area near Churchill, Manitoba. Funding was awarded because the proposed EMAN-North project addressed the NEI priority of Monitoring Ecosystem Status and Trends, and Ecosystem Impacts of Climate Change. The project was also aimed at improving the network's capacity for long-term ecological monitoring, assessment and reporting. Several activities deal specifically with ecological impacts of climate change. This paper described the need and the context for ecological monitoring in northern Canada and defined a strategic direction for EMAN-North. The project will include many individuals involved in ecological monitoring in the north to deliver information on ecosystem changes to decision-makers and the public. refs., tabs., figs

  7. Effects of barium chloride treatment of uranium mill tailings and ore on radon emanation and 226Ra levels. Progress report

    International Nuclear Information System (INIS)

    Ibrahim, S.A.; Flot, S.L.

    1983-01-01

    The purpose of this study was to investigate the effect of barium chloride treatments on: reduction of 222 Rn emanation from mill wastes; reduction of 226 Ra levels in wastewater; and decreased leachability of 226 Ra from mill wastes. Baseline 226 Ra concentrations were determined for ore and tailings as well as radon emanation fractions. Uranium ore was treated with soluble barium at concentrations of 10, 25, 50, and 100 mg per litre of slurry. The leach-liquor declined in 226 Ra concentration by as much as 50%. When soluble potassium as well as barium was used in the treatment process at equal concentrations of 10, 25, 50, and 100 mg per litre of slurry, a similar reduction was observed. No significant difference was noted between the two treatment regimes. An accelerated leaching experiment was performed on the ore treated with barium chloride. All treatment groups except that treated with 10 mg of soluble barium per litre of slurry showed significant decreases in leachability. Available 222 Rn (corresponds with radon emanation fraction) was measured in treated and untreated ore. Ore treated with concentrations of Ba ++ up to 1.00 mg per gram of ore did not show a statistically significant reduction in available 222 Rn, however when potassium sulfate was also added, a significant decline was noted. This study suggests that barium chloride treatments reduce radon emanation from mill wastes and reduce 226 Ra levels in wastewater. Leachability of 226 Ra from treated samples decreased markedly. 19 references, 8 figures, 7 tables

  8. Mars' surface radiation environment measured with the Mars Science Laboratory's Curiosity rover.

    Science.gov (United States)

    Hassler, Donald M; Zeitlin, Cary; Wimmer-Schweingruber, Robert F; Ehresmann, Bent; Rafkin, Scot; Eigenbrode, Jennifer L; Brinza, David E; Weigle, Gerald; Böttcher, Stephan; Böhm, Eckart; Burmeister, Soenke; Guo, Jingnan; Köhler, Jan; Martin, Cesar; Reitz, Guenther; Cucinotta, Francis A; Kim, Myung-Hee; Grinspoon, David; Bullock, Mark A; Posner, Arik; Gómez-Elvira, Javier; Vasavada, Ashwin; Grotzinger, John P

    2014-01-24

    The Radiation Assessment Detector (RAD) on the Mars Science Laboratory's Curiosity rover began making detailed measurements of the cosmic ray and energetic particle radiation environment on the surface of Mars on 7 August 2012. We report and discuss measurements of the absorbed dose and dose equivalent from galactic cosmic rays and solar energetic particles on the martian surface for ~300 days of observations during the current solar maximum. These measurements provide insight into the radiation hazards associated with a human mission to the surface of Mars and provide an anchor point with which to model the subsurface radiation environment, with implications for microbial survival times of any possible extant or past life, as well as for the preservation of potential organic biosignatures of the ancient martian environment.

  9. Mars' Surface Radiation Environment Measured with the Mars Science Laboratory's Curiosity Rover

    Science.gov (United States)

    Hassler, Donald M.; Zeitlin, Cary; Wimmer-Schweingruber, Robert F.; Ehresmann, Bent; Rafkin, Scot; Eigenbrode, Jennifer L.; Brinza, David E.; Weigle, Gerald; Böttcher, Stephan; Böhm, Eckart; Burmeister, Soenke; Guo, Jingnan; Köhler, Jan; Martin, Cesar; Reitz, Guenther; Cucinotta, Francis A.; Kim, Myung-Hee; Grinspoon, David; Bullock, Mark A.; Posner, Arik; Gómez-Elvira, Javier; Vasavada, Ashwin; Grotzinger, John P.; MSL Science Team; Kemppinen, Osku; Cremers, David; Bell, James F.; Edgar, Lauren; Farmer, Jack; Godber, Austin; Wadhwa, Meenakshi; Wellington, Danika; McEwan, Ian; Newman, Claire; Richardson, Mark; Charpentier, Antoine; Peret, Laurent; King, Penelope; Blank, Jennifer; Schmidt, Mariek; Li, Shuai; Milliken, Ralph; Robertson, Kevin; Sun, Vivian; Baker, Michael; Edwards, Christopher; Ehlmann, Bethany; Farley, Kenneth; Griffes, Jennifer; Miller, Hayden; Newcombe, Megan; Pilorget, Cedric; Rice, Melissa; Siebach, Kirsten; Stack, Katie; Stolper, Edward; Brunet, Claude; Hipkin, Victoria; Léveillé, Richard; Marchand, Geneviève; Sánchez, Pablo Sobrón; Favot, Laurent; Cody, George; Steele, Andrew; Flückiger, Lorenzo; Lees, David; Nefian, Ara; Martin, Mildred; Gailhanou, Marc; Westall, Frances; Israël, Guy; Agard, Christophe; Baroukh, Julien; Donny, Christophe; Gaboriaud, Alain; Guillemot, Philippe; Lafaille, Vivian; Lorigny, Eric; Paillet, Alexis; Pérez, René; Saccoccio, Muriel; Yana, Charles; Armiens-Aparicio, Carlos; Rodríguez, Javier Caride; Blázquez, Isaías Carrasco; Gómez, Felipe Gómez; Hettrich, Sebastian; Malvitte, Alain Lepinette; Jiménez, Mercedes Marín; Martínez-Frías, Jesús; Martín-Soler, Javier; Martín-Torres, F. Javier; Jurado, Antonio Molina; Mora-Sotomayor, Luis; Caro, Guillermo Muñoz; López, Sara Navarro; Peinado-González, Verónica; Pla-García, Jorge; Manfredi, José Antonio Rodriguez; Romeral-Planelló, Julio José; Fuentes, Sara Alejandra Sans; Martinez, Eduardo Sebastian; Redondo, Josefina Torres; Urqui-O'Callaghan, Roser; Mier, María-Paz Zorzano; Chipera, Steve; Lacour, Jean-Luc; Mauchien, Patrick; Sirven, Jean-Baptiste; Manning, Heidi; Fairén, Alberto; Hayes, Alexander; Joseph, Jonathan; Squyres, Steven; Sullivan, Robert; Thomas, Peter; Dupont, Audrey; Lundberg, Angela; Melikechi, Noureddine; Mezzacappa, Alissa; Berger, Thomas; Matthia, Daniel; Prats, Benito; Atlaskin, Evgeny; Genzer, Maria; Harri, Ari-Matti; Haukka, Harri; Kahanpää, Henrik; Kauhanen, Janne; Kemppinen, Osku; Paton, Mark; Polkko, Jouni; Schmidt, Walter; Siili, Tero; Fabre, Cécile; Wray, James; Wilhelm, Mary Beth; Poitrasson, Franck; Patel, Kiran; Gorevan, Stephen; Indyk, Stephen; Paulsen, Gale; Gupta, Sanjeev; Bish, David; Schieber, Juergen; Gondet, Brigitte; Langevin, Yves; Geffroy, Claude; Baratoux, David; Berger, Gilles; Cros, Alain; d'Uston, Claude; Forni, Olivier; Gasnault, Olivier; Lasue, Jérémie; Lee, Qiu-Mei; Maurice, Sylvestre; Meslin, Pierre-Yves; Pallier, Etienne; Parot, Yann; Pinet, Patrick; Schröder, Susanne; Toplis, Mike; Lewin, Éric; Brunner, Will; Heydari, Ezat; Achilles, Cherie; Oehler, Dorothy; Sutter, Brad; Cabane, Michel; Coscia, David; Israël, Guy; Szopa, Cyril; Dromart, Gilles; Robert, François; Sautter, Violaine; Le Mouélic, Stéphane; Mangold, Nicolas; Nachon, Marion; Buch, Arnaud; Stalport, Fabien; Coll, Patrice; François, Pascaline; Raulin, François; Teinturier, Samuel; Cameron, James; Clegg, Sam; Cousin, Agnès; DeLapp, Dorothea; Dingler, Robert; Jackson, Ryan Steele; Johnstone, Stephen; Lanza, Nina; Little, Cynthia; Nelson, Tony; Wiens, Roger C.; Williams, Richard B.; Jones, Andrea; Kirkland, Laurel; Treiman, Allan; Baker, Burt; Cantor, Bruce; Caplinger, Michael; Davis, Scott; Duston, Brian; Edgett, Kenneth; Fay, Donald; Hardgrove, Craig; Harker, David; Herrera, Paul; Jensen, Elsa; Kennedy, Megan R.; Krezoski, Gillian; Krysak, Daniel; Lipkaman, Leslie; Malin, Michael; McCartney, Elaina; McNair, Sean; Nixon, Brian; Posiolova, Liliya; Ravine, Michael; Salamon, Andrew; Saper, Lee; Stoiber, Kevin; Supulver, Kimberley; Van Beek, Jason; Van Beek, Tessa; Zimdar, Robert; French, Katherine Louise; Iagnemma, Karl; Miller, Kristen; Summons, Roger; Goesmann, Fred; Goetz, Walter; Hviid, Stubbe; Johnson, Micah; Lefavor, Matthew; Lyness, Eric; Breves, Elly; Dyar, M. Darby; Fassett, Caleb; Blake, David F.; Bristow, Thomas; DesMarais, David; Edwards, Laurence; Haberle, Robert; Hoehler, Tori; Hollingsworth, Jeff; Kahre, Melinda; Keely, Leslie; McKay, Christopher; Wilhelm, Mary Beth; Bleacher, Lora; Brinckerhoff, William; Choi, David; Conrad, Pamela; Dworkin, Jason P.; Floyd, Melissa; Freissinet, Caroline; Garvin, James; Glavin, Daniel; Harpold, Daniel; Jones, Andrea; Mahaffy, Paul; Martin, David K.; McAdam, Amy; Pavlov, Alexander; Raaen, Eric; Smith, Michael D.; Stern, Jennifer; Tan, Florence; Trainer, Melissa; Meyer, Michael; Voytek, Mary; Anderson, Robert C.; Aubrey, Andrew; Beegle, Luther W.; Behar, Alberto; Blaney, Diana; Calef, Fred; Christensen, Lance; Crisp, Joy A.; DeFlores, Lauren; Ehlmann, Bethany; Feldman, Jason; Feldman, Sabrina; Flesch, Gregory; Hurowitz, Joel; Jun, Insoo; Keymeulen, Didier; Maki, Justin; Mischna, Michael; Morookian, John Michael; Parker, Timothy; Pavri, Betina; Schoppers, Marcel; Sengstacken, Aaron; Simmonds, John J.; Spanovich, Nicole; Juarez, Manuel de la Torre; Webster, Christopher R.; Yen, Albert; Archer, Paul Douglas; Jones, John H.; Ming, Douglas; Morris, Richard V.; Niles, Paul; Rampe, Elizabeth; Nolan, Thomas; Fisk, Martin; Radziemski, Leon; Barraclough, Bruce; Bender, Steve; Berman, Daniel; Dobrea, Eldar Noe; Tokar, Robert; Vaniman, David; Williams, Rebecca M. E.; Yingst, Aileen; Lewis, Kevin; Leshin, Laurie; Cleghorn, Timothy; Huntress, Wesley; Manhès, Gérard; Hudgins, Judy; Olson, Timothy; Stewart, Noel; Sarrazin, Philippe; Grant, John; Vicenzi, Edward; Wilson, Sharon A.; Hamilton, Victoria; Peterson, Joseph; Fedosov, Fedor; Golovin, Dmitry; Karpushkina, Natalya; Kozyrev, Alexander; Litvak, Maxim; Malakhov, Alexey; Mitrofanov, Igor; Mokrousov, Maxim; Nikiforov, Sergey; Prokhorov, Vasily; Sanin, Anton; Tretyakov, Vladislav; Varenikov, Alexey; Vostrukhin, Andrey; Kuzmin, Ruslan; Clark, Benton; Wolff, Michael; McLennan, Scott; Botta, Oliver; Drake, Darrell; Bean, Keri; Lemmon, Mark; Schwenzer, Susanne P.; Anderson, Ryan B.; Herkenhoff, Kenneth; Lee, Ella Mae; Sucharski, Robert; Hernández, Miguel Ángel de Pablo; Ávalos, Juan José Blanco; Ramos, Miguel; Malespin, Charles; Plante, Ianik; Muller, Jan-Peter; Navarro-González, Rafael; Ewing, Ryan; Boynton, William; Downs, Robert; Fitzgibbon, Mike; Harshman, Karl; Morrison, Shaunna; Dietrich, William; Kortmann, Onno; Palucis, Marisa; Sumner, Dawn Y.; Williams, Amy; Lugmair, Günter; Wilson, Michael A.; Rubin, David; Jakosky, Bruce; Balic-Zunic, Tonci; Frydenvang, Jens; Jensen, Jaqueline Kløvgaard; Kinch, Kjartan; Koefoed, Asmus; Madsen, Morten Bo; Stipp, Susan Louise Svane; Boyd, Nick; Campbell, John L.; Gellert, Ralf; Perrett, Glynis; Pradler, Irina; VanBommel, Scott; Jacob, Samantha; Owen, Tobias; Rowland, Scott; Atlaskin, Evgeny; Savijärvi, Hannu; García, César Martín; Mueller-Mellin, Reinhold; Bridges, John C.; McConnochie, Timothy; Benna, Mehdi; Franz, Heather; Bower, Hannah; Brunner, Anna; Blau, Hannah; Boucher, Thomas; Carmosino, Marco; Atreya, Sushil; Elliott, Harvey; Halleaux, Douglas; Rennó, Nilton; Wong, Michael; Pepin, Robert; Elliott, Beverley; Spray, John; Thompson, Lucy; Gordon, Suzanne; Newsom, Horton; Ollila, Ann; Williams, Joshua; Vasconcelos, Paulo; Bentz, Jennifer; Nealson, Kenneth; Popa, Radu; Kah, Linda C.; Moersch, Jeffrey; Tate, Christopher; Day, Mackenzie; Kocurek, Gary; Hallet, Bernard; Sletten, Ronald; Francis, Raymond; McCullough, Emily; Cloutis, Ed; ten Kate, Inge Loes; Kuzmin, Ruslan; Arvidson, Raymond; Fraeman, Abigail; Scholes, Daniel; Slavney, Susan; Stein, Thomas; Ward, Jennifer; Berger, Jeffrey; Moores, John E.

    2014-01-01

    The Radiation Assessment Detector (RAD) on the Mars Science Laboratory's Curiosity rover began making detailed measurements of the cosmic ray and energetic particle radiation environment on the surface of Mars on 7 August 2012. We report and discuss measurements of the absorbed dose and dose equivalent from galactic cosmic rays and solar energetic particles on the martian surface for ~300 days of observations during the current solar maximum. These measurements provide insight into the radiation hazards associated with a human mission to the surface of Mars and provide an anchor point with which to model the subsurface radiation environment, with implications for microbial survival times of any possible extant or past life, as well as for the preservation of potential organic biosignatures of the ancient martian environment.

  10. An assessment on the recycling opportunities of wastes emanating from scrap metal processing in Mauritius

    International Nuclear Information System (INIS)

    Mauthoor, Sumayya; Mohee, Romeela; Kowlesser, Prakash

    2014-01-01

    Highlights: • Scrap metal processing wastes. • Areas of applications for slag, electric arc furnace dust, mill scale and wastewater sludge. • Waste generation factor of 349.3 kg per ton of steel produced. • Waste management model. - Abstract: This paper presents an assessment on the wastes namely slag, dust, mill scale and sludge resulting from scrap metal processing. The aim of this study is to demonstrate that there are various ways via which scrap metal processing wastes can be reused or recycled in other applications instead of simply diverting them to the landfill. These wastes are briefly described and an overview on the different areas of applications is presented. Based on the results obtained, the waste generation factor developed was 349.3 kg per ton of steel produced and it was reported that slag represents 72% of the total wastes emanating from the iron and steel industry in Mauritius. Finally the suitability of the different treatment and valorisation options in the context of Mauritius is examined

  11. A theoretical and experimental EPFM study of cracks emanating from a hole

    International Nuclear Information System (INIS)

    Broekhoven, M.J.G.

    1978-01-01

    Results are presented of a combined theoretical and experimental study on the onset of crack extension in the EPFM regime for through cracks emanating from a circular hole in a plate under tensile load, with emphasis on the applicability of the J-concept for predicting such extensions. This configuration was selected both because of its general importance and as a first approximation for a nozzle-to-vessel geometry. Theoretical investigations consisted of elastic-plastic finite element computations both for 3-point bend specimens and for plate geometry. J values were calculated using the contour-integral definition for J, and by the method of virtual crack extension. The applicability of simplified analytical approximations for J was also investigated. COD data were derived from finite element computed displacements. Experimental investigations included Jsub(Ic) tests on a series of bend specimens and crack extensions tests on a series of cracked perforated plate models. For practical reasons aluminium 2024-T 351 was selected as a suitable model material within the aims of the study. Onset of crack extension was determined by the heat-tinting procedure throughout the experiments, in some cases supplemented by fractographic investigations. The various theoretical solutions and experimental observations were compared and a number of conclusions were drawn. (author)

  12. Recycling of lime sludge emanating from tannery industry through vermicomposting using Eisenia foetida.

    Science.gov (United States)

    Subash, Anitha; Gomathi, M; Kanagavalli, M; Sindhiya, D

    2012-07-01

    The research was focused on the control of pollution, which is caused due to tannery waste disposal, through the process of vermicomposting. Earthworms have increasingly been used for waste management. Therefore, the main aim of this study was to recycle the lime sludge emanating from a selected tannery industry through vermicomposting. Tannery solid waste was allowed to compost for 60 days, and then the composts were harvested and analyzed for selected physio-chemical and biochemical parameters. A flowering plant namely Tagets erecta Linn was grown in soil mixed with the vermicomposts obtained, and was studied for its growth attributes and compared with the control plant growth on soil alone. The attributes studied were biometric parameters, like root length, shoot length, plant height, plant weight, number of leaves, flowers and buds. The alkaline nature of the lime sludge was reduced to neutral range on vermicomposting. The electrical conductivity of the lime sludge was also reduced on vermicomposting which might be due to the transformation of complex organic compounds into simpler forms. The biochemical parameters, such as nitrogen and carbon were also reduced on vermicomposting.

  13. The ISIS Mission Concept: An Impactor for Surface and Interior Science

    Science.gov (United States)

    Chesley, Steven R.; Elliot, John O.; Abell, Paul A.; Asphaug, Erik; Bhaskaran, Shyam; Lam, Try; Lauretta, Dante S.

    2013-01-01

    The Impactor for Surface and Interior Science (ISIS) mission concept is a kinetic asteroid impactor mission to the target of NASA's OSIRIS-REx (Origins-Spectral Interpretation-Resource Identification-Security-Regolith Explorer) asteroid sample return mission. The ISIS mission concept calls for the ISIS spacecraft, an independent and autonomous smart impactor, to guide itself to a hyper-velocity impact with 1999 RQ36 while the OSIRIS-REx spacecraft observes the collision. Later the OSIRIS-REx spacecraft descends to reconnoiter the impact site and measure the momentum imparted to the asteroid through the impact before departing on its journey back to Earth. In this paper we discuss the planetary science, human exploration and impact mitigation drivers for mission, and we describe the current mission concept and flight system design.

  14. PREFACE: 6th Vacuum and Surface Sciences Conference of Asia and Australia (VASSCAA-6)

    Science.gov (United States)

    Ahsan Bhatti, Javaid; Hussain, Talib; Khan, Wakil

    2013-06-01

    The Vacuum and Surface Sciences Conference of Asia and Australia (VASSCAA) conference series has been organized to create a new forum in Asia and Australia to discuss vacuum, surface and related sciences, techniques and applications. The conference series is officially endorsed by the International Union for Vacuum Science, Technique and Application (IUVSTA). The International Steering Committee of VASSCAA is comprised of Vacuum Societies in seven countries: Australia, China, India, Iran, Japan, South Korea and Pakistan. VASSCAA-1 was organized by the Vacuum Society of Japan in 1999 in Tokyo, Japan. VASSCAA-2 was held in 2002 in Hong Kong, VASSCAA-3 in Singapore in 2005. VASSCAA-4 was held in Matsue, Japan in 2008 and VASSCAA-5 in 2010 in Beijing, China. The 6th Vacuum and Surface Sciences Conference of Asia and Australia (VASSCAA-6) was held from 9-13 October 2012 in the beautiful city of Islamabad, Pakistan. The venue of the conference was the Pak-China Friendship Centre, Islamabad. More than six hundred local delgates and around seventy delegates from different countries participated in this mega event. These delegates included scientists, researchers, engineers, professors, plant operators, designers, vendors, industrialists, businessmen and students from various research organizations, technical institutions, universities, industries and companies from Pakistan and abroad. The focal point of the event was to enhance cooperation between Pakistan and the international community in the fields of vacuum, surface science and other applied technologies. At VASSCAA-6 85 oral presentations were delivered by local and foreign speakers. These were divided into different sessions according to their fields. A poster session was organized at which over 70 researchers and students displayed their posters. The best three posters won prizes. In parallel to the main conference sessions four technical short courses were held. The participants showed keen interest in all these

  15. Ambient pressure photoelectron spectroscopy: a new tool for surface science and nanotechnology

    Energy Technology Data Exchange (ETDEWEB)

    Salmeron, Miquel; Salmeron, Miquel; Schlogl, Robert

    2008-03-12

    Progress in science often follows or parallels the development of new techniques. The optical microscope helped convert medicine and biology from a speculative activity in old times to today's sophisticated scientific disciplines. The telescope changed the study and interpretation of heavens from mythology to science. X-ray diffraction enabled the flourishing of solid state physics and materials science. The technique object of this review, Ambient Pressure Photoelectron Spectroscopy or APPES for short, has also the potential of producing dramatic changes in the study of liquid and solid surfaces, particularly in areas such as atmospheric, environment and catalysis sciences. APPES adds an important missing element to the host of techniques that give fundamental information, i.e., spectroscopy and microscopy, about surfaces in the presence of gases and vapors, as encountered in industrial catalysis and atmospheric environments. APPES brings electron spectroscopy into the realm of techniques that can be used in practical environments. Decades of surface science in ultra high vacuum (UHV) has shown the power of electron spectroscopy in its various manifestations. Their unique property is the extremely short elastic mean free path of electrons as they travel through condensed matter, of the order of a few atomic distances in the energy range from a few eV to a few thousand eV. As a consequence of this the information obtained by analyzing electrons emitted or scattered from a surface refers to the top first few atomic layers, which is what surface science is all about. Low energy electron diffraction (LEED), Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), Ultraviolet photoelectron spectroscopy (UPS), and other such techniques have been used for decades and provided some of the most fundamental knowledge about surface crystallography, composition and electronic structure available today. Unfortunately the high interaction cross section of

  16. Optimized measurement of radium-226 concentration in liquid samples with radon-222 emanation.

    Science.gov (United States)

    Perrier, Frédéric; Aupiais, Jean; Girault, Frédéric; Przylibski, Tadeusz A; Bouquerel, Hélène

    2016-06-01

    Measuring radium-226 concentration in liquid samples using radon-222 emanation remains competitive with techniques such as liquid scintillation, alpha or mass spectrometry. Indeed, we show that high-precision can be obtained without air circulation, using an optimal air to liquid volume ratio and moderate heating. Cost-effective and efficient measurement of radon concentration is achieved by scintillation flasks and sufficiently long counting times for signal and background. More than 400 such measurements were performed, including 39 dilution experiments, a successful blind measurement of six reference test solutions, and more than 110 repeated measurements. Under optimal conditions, uncertainties reach 5% for an activity concentration of 100 mBq L(-1) and 10% for 10 mBq L(-1). While the theoretical detection limit predicted by Monte Carlo simulation is around 3 mBq L(-1), a conservative experimental estimate is rather 5 mBq L(-1), corresponding to 0.14 fg g(-1). The method was applied to 47 natural waters, 51 commercial waters, and 17 wine samples, illustrating that it could be an option for liquids that cannot be easily measured by other methods. Counting of scintillation flasks can be done in remote locations in absence of electricity supply, using a solar panel. Thus, this portable method, which has demonstrated sufficient accuracy for numerous natural liquids, could be useful in geological and environmental problems, with the additional benefit that it can be applied in isolated locations and in circumstances when samples cannot be transported. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Evaluation of U, Th, K and emanated radon in some NORM and TENORM samples

    Energy Technology Data Exchange (ETDEWEB)

    El Afifi, E.M. [Hot Laboratories and Waste Management Center (HLWMC), Atomic Energy Authority, P.O. Box No. 13759, Cairo (Egypt)]. E-mail: em_afifi@yahoo.com; Hilal, M.A. [Hot Laboratories and Waste Management Center (HLWMC), Atomic Energy Authority, P.O. Box No. 13759, Cairo (Egypt); Khalifa, S.M. [Hot Laboratories and Waste Management Center (HLWMC), Atomic Energy Authority, P.O. Box No. 13759, Cairo (Egypt); Aly, H.F. [Hot Laboratories and Waste Management Center (HLWMC), Atomic Energy Authority, P.O. Box No. 13759, Cairo (Egypt)

    2006-05-15

    Activity concentrations of {sup 226}Ra (of U-series), {sup 228}Ra (of Th-series) and potassium ({sup 40}K) in some heavy minerals and building materials were determined and evaluated in some selected heavy mineral sands and building materials. Three heavy mineral sands (monazite, zircon and black sand) of industrial interest were used. Building materials used here include phosphogypsum (PG) wastes, natural gypsum, ceramics, granite, marble, cement and iron slag wastes associated with iron and steel production. The measurements were carried out using {gamma}-ray spectrometry. The activity concentrations varied widely depending on sample origin. The results indicated that the high activity levels, radium equivalent activity, absorbed-gamma dose rate and effective annual dose rate were found in monazite, zircon and PG wastes as compared to the other materials. The mean activity concentrations in monazite were 40580+/-1370, 182425+/-9870 and 11300+/-9570Bqkg{sup -1} for {sup 238}U, {sup 232}Th and {sup 40}K, respectively. This activity is equivalent to 0.39, 5.1 and 4.5wt% for uranium as U{sub 3}O{sub 8}, thorium as ThO{sub 2} and potassium-40 as K{sub 2}O, respectively. The radium equivalent activity, absorbed-gamma dose rate and effective annual dose rate in monazite were 3.0x10{sup 5}Bqkg{sup -1}, 1.3x10{sup 5}nGyh{sup -1} and 163mSvyr{sup -1}, respectively. The emanation coefficient (EC) of {sup 222}Rn was less than 20%. The average Rn EC was 18% for cement samples and {approx}14% for granite and ceramic samples. It concluded that the Rosetta beach could be considered a valuable source for some metallurgical processes of industrial interest, but with special precautions. Most of the studied building materials can be used without restrictions except PG wastes, granite and ceramic.

  18. [Filarial infestation in patients emanating from endemic area. 14 cases series presentation].

    Science.gov (United States)

    Cuello, M Rivera; Cuadros, E Núñez; Claros, A Medina; Hortelano, M García; Fontelos, P Martín; Peña, M J Mellado

    2009-09-01

    The migration causes the emergence of new diseases in our environment. One of them is the filariosis which, due to the biologic cycle peculiarity, it's weird its appearance in pediatrics. This studio accomplishes a review of all the filariosis cases diagnosed the last years in an Unit specialized in Tropical Pediatrics Diseases. Retrospective analysis comprising 14 patients than were diagnosed with filariosis from 1995 to 2007 in the Pediatrics Unit of Carlos III Hospital (Madrid). They have been analyzed several variables to cope with clinic-epidemiological, therapeutics and evolutional characteristics. All patients in the study came from Equatorial Guinea, their ages were between 3 and 15 years old. The isolated species were: 6 cases with O. volvulus, 8 with M. perstans and 2 with Loa-loa. The pruritus was the main symptom in the 71% of the cases. The eosinophilia was detected in the 78% of the patients, and the Loa-loa was the specie with higher figures. The 85% of the patients showed co-parasitation, being the intestinal the most frequent. The diagnostics was established by epidermic biopsy, microfilaremia detection, direct visualization and serology. The utilized drugs were: Mebendazole for the cases with M. perstans and Ivermectin or Dietylcarbamazine for the rest of the species. One child showed mixed filariosis. The cure was successful in the 8 cases that could be followed up. We consider essential to execute a filariosis screening to every patient emanating from endemic area, especially to those with eosinophilia. The diagnostic in the childhood, even though it's difficult, it allows the prevention of the disease development, serious complications as blindness and break the parasite life cycle.

  19. Towards an atomic level understanding of niobia based catalysts and catalysis by combining the science of catalysis with surface science

    Directory of Open Access Journals (Sweden)

    Martin Schmal

    2009-06-01

    Full Text Available The science of catalysis and surface science have developed, independently, key information for understanding catalytic processes. One might argue: is there anything fundamental to be discovered through the interplay between catalysis and surface science? Real catalysts of monometallic and bimetallic Co/Nb2O5 and Pd-Co/Nb2O5 catalysts showed interesting selectivity results on the Fischer-Tropsch synthesis (Noronha et al. 1996, Rosenir et al. 1993. The presence of a noble metal increased the C+5 selectivity and decreased the methane formation depending of the reduction temperature. Model catalyst of Co-Pd supported on niobia and alumina were prepared and characterized at the atomic level, thus forming the basis for a comparison with "real" support materials. Growth, morphology and structure of both pure metal and alloy particles were studied. It is possible to support the strong metal support interaction suggested by studies on real catalysts via the investigation of model systems for niobia in comparison to alumina support in which this effect does not occur. Formation of Co2+ penetration into the niobia lattice was suggested on the basis of powder studies and can be fully supported on the basis of model studies. It is shown for both real catalysts and model systems that oxidation state of Co plays a key role in controlling the reactivity in Fischer-Tropsch reactions systems and that the addition of Pd is a determining factor for the stability of the catalyst. It is demonstrated that the interaction with unsaturated hydrocarbons depends strongly on the state of oxidation.As ciências da catálise e da superfície têm desenvolvido independentemente temas básicos para o entendimento de processos catalíticos. Pode-se até questionar se há ainda algo fundamental para ser descoberto através da interface entre catálise eciência da superfície? Catalisadores mono e bimetálicos de Co/Nb2O5 e Pd-Co/ Nb2O5 apresentaram resultados interessantes de

  20. Adsorption of DNA onto gold nanoparticles and graphene oxide: surface science and applications.

    Science.gov (United States)

    Liu, Juewen

    2012-08-14

    The interaction between DNA and inorganic surfaces has attracted intense research interest, as a detailed understanding of adsorption and desorption is required for DNA microarray optimization, biosensor development, and nanoparticle functionalization. One of the most commonly studied surfaces is gold due to its unique optical and electric properties. Through various surface science tools, it was found that thiolated DNA can interact with gold not only via the thiol group but also through the DNA bases. Most of the previous work has been performed with planar gold surfaces. However, knowledge gained from planar gold may not be directly applicable to gold nanoparticles (AuNPs) for several reasons. First, DNA adsorption affinity is a function of AuNP size. Second, DNA may interact with AuNPs differently due to the high curvature. Finally, the colloidal stability of AuNPs confines salt concentration, whereas there is no such limit for planar gold. In addition to gold, graphene oxide (GO) has emerged as a new material for interfacing with DNA. GO and AuNPs share many similar properties for DNA adsorption; both have negatively charged surfaces but can still strongly adsorb DNA, and both are excellent fluorescence quenchers. Similar analytical and biomedical applications have been demonstrated with these two surfaces. The nature of the attractive force however, is different for each of these. DNA adsorption on AuNPs occurs via specific chemical interactions but adsorption on GO occurs via aromatic stacking and hydrophobic interactions. Herein, we summarize the recent developments in studying non-thiolated DNA adsorption and desorption as a function of salt, pH, temperature and DNA secondary structures. Potential future directions and applications are also discussed.

  1. Effects of barium chlorine treatment of uranium ore on 222Rn emanation and 226Ra leachability from mill tailings

    International Nuclear Information System (INIS)

    Ibrahim, S.A.; Church, S.L.; Whicker, F.W.

    1985-01-01

    The purpose of this laboratory study was to investigate the effectiveness of barium chloride treatment of uranium ore on 222 Rn emanation from mill tailings, 226 Ra level in waste-water, and the leachability of radium from tailings. It has been shown that barium sulfate is an excellent carrier for radium and that barium sulfate crystals have high retention capacity for radon gas produced by radium trapped within the lattice. Ground uranium ore from a mine in Wyoming was mixed with water to form a 1:1 ratio before barium and potassium chlorides were added at concentrations of 0, 10, 25, 50, and 100 mg per liter of slurry. The ore was then subjected to a simulated mill process using sulfuric acid leaching. The liquid representing tailings pond water was separated and analyzed for 226 Ra and the solid fraction, representing mill tailings, was tested for radon emanation and the leachability of radium by deionized water. This study suggests that barium treatment of uranium ore prior to sulfuric acid leaching could be effective in reducing radon emanation from tailings and also in reducing the 226 Ra concentration of waste-water. Leachability of radium from treated tailings was markedly reduced

  2. The Applicability of Traditional Protection Methods to Lines Emanating from VSC-HVDC Interconnectors and a Novel Protection Principle

    Directory of Open Access Journals (Sweden)

    Shimin Xue

    2016-05-01

    Full Text Available Voltage source converter (VSC-based high voltage direct current (VSC-HVDC interconnectors can realize accurate and fast control of power transmission among AC networks, and provide emergency power support for AC networks. VSC-HVDC interconnectors bring exclusive fault characteristics to AC networks, thus influencing the performance of traditional protections. Since fault characteristics are related to the control schemes of interconnectors, a fault ride-through (FRT strategy which is applicable to the interconnector operating characteristic of working in four quadrants and capable of eliminating negative-sequence currents under unbalanced fault conditions is proposed first. Then, the additional terms of measured impedances of distance relays caused by fault resistances are derived using a symmetrical component method. Theoretical analysis shows the output currents of interconnectors are controllable after faults, which may cause malfunctions in distance protections installed on lines emanating from interconnectors under the effect of fault resistances. Pilot protection is also inapplicable to lines emanating from interconnectors. Furthermore, a novel pilot protection principle based on the ratio between phase currents and the ratio between negative-sequence currents flowing through both sides is proposed for lines emanating from the interconnectors whose control scheme aims at eliminating negative-sequence currents. The validity of theoretical analysis and the protection principle is verified by PSCAD/EMTDC simulations.

  3. The effect of time-dependent ventilation and radon (thoron) gas emanation rates in underground uranium mines

    International Nuclear Information System (INIS)

    Bigu, J.

    1987-01-01

    A theoretical radiation mine model, suitable for underground uranium mines, has been investigated. In this model, the rate of ventilation and/or the radon (thoron) gas emanation from mine walls are time-dependent. Several cases of practical interest have been investigated including sinusoidal, linear, exponential, stepwise, or a combination of two or more of the above. Analytical solutions were obtained for the time-dependent radon (thoron) gas emanation rate. However, because of the extreme analytical complexity of the solutions corresponding to the time-dependent ventilation rate case, numerical solutions were found using a special Runge-Kutta procedure and the Hamming's modified predictor-corrector method for the solution of linear initial-value problems. The mine model makes provisions for losses of radioactivity, other than by ventilation and radioactive decay, by, say, plate-out on mine walls, and by other mechanisms. Radioactivity data, i.e., radon, thoron, and their progeny, obtained with the above mine model for a number of ventilation and emanation conditions, are presented. Experimental data obtained in an inactive stope of an underground uranium mine for a time-dependent air flow case are shown. Air flow conditions (ventilation rate) were determined by tracer gas techniques using SF 6

  4. Desert Research and Technology Studies (DRATS) 2010 Science Operations: Operational Approaches and Lessons Learned for Managing Science during Human Planetary Surface Missions

    Science.gov (United States)

    Eppler, Dean; Adams, Byron; Archer, Doug; Baiden, Greg; Brown, Adrian; Carey, William; Cohen, Barbara; Condit, Chris; Evans, Cindy; Fortezzo, Corey; hide

    2012-01-01

    Desert Research and Technology Studies (Desert RATS) is a multi-year series of hardware and operations tests carried out annually in the high desert of Arizona on the San Francisco Volcanic Field. These activities are designed to exercise planetary surface hardware and operations in conditions where long-distance, multi-day roving is achievable, and they allow NASA to evaluate different mission concepts and approaches in an environment less costly and more forgiving than space.The results from the RATS tests allows election of potential operational approaches to planetary surface exploration prior to making commitments to specific flight and mission hardware development. In previous RATS operations, the Science Support Room has operated largely in an advisory role, an approach that was driven by the need to provide a loose science mission framework that would underpin the engineering tests. However, the extensive nature of the traverse operations for 2010 expanded the role of the science operations and tested specific operational approaches. Science mission operations approaches from the Apollo and Mars-Phoenix missions were merged to become the baseline for this test. Six days of traverse operations were conducted during each week of the 2-week test, with three traverse days each week conducted with voice and data communications continuously available, and three traverse days conducted with only two 1-hour communications periods per day. Within this framework, the team evaluated integrated science operations management using real-time, tactical science operations to oversee daily crew activities, and strategic level evaluations of science data and daily traverse results during a post-traverse planning shift. During continuous communications, both tactical and strategic teams were employed. On days when communications were reduced to only two communications periods per day, only a strategic team was employed. The Science Operations Team found that, if

  5. Mars in Motion: An online Citizen Science platform looking for changes on the surface of Mars

    Science.gov (United States)

    Sprinks, James Christopher; Wardlaw, Jessica; Houghton, Robert; Bamford, Steven; Marsh, Stuart

    2016-10-01

    The European FP7 iMars project has developed tools and 3D models of the Martian surface through the co-registration of NASA and ESA mission data dating from the Viking missions of the 1970s to the present day, for a much more comprehensive interpretation of the geomorphological and climatic processes that have taken and do take place. We present the Citizen Science component of the project, 'Mars in Motion', created through the Zooniverse's Panoptes framework to allow volunteers to look for and identify changes on the surface of Mars over time. 'Mars in Motion', as with many other current citizen science platforms of a planetary or other disciplinary focus, has been developed to compliment the results of automated data mining analysis software, both by validation through the creation of training data and by adding context - gathering more in-depth data on the type and metrics of change initially detected.Through the analysis of initial volunteer results collected in the second half of 2016, the accuracy and ability of untrained participants to identify geomorphological changes is considered, as well as the impact of their position in the system. Volunteer contribution, either as a filter for poor quality imagery pre-algorithm, validation of algorithmic analysis, or adding context to pre-detected change, and their awareness and interpretation of its importance, can directly influence engagement with the platform and therefore ultimately its success. Understanding the effect of the volunteer and software's role in the system on both the results of and engagement with planetary science citizen science platforms will be an important lesson for the future, especially as the next generation of planetary missions will likely collect data orders of magnitude greater in volume. To deal with the data overload, it is likely that human or software solutions alone will not be sufficient, and that a combination of the two working together in a complimentary system that combines

  6. Specific features of electric field in the atmosphere and Radon emanations in Tunkin Basin of Baikal rift zone

    Science.gov (United States)

    Soloviev, S.; Loktev, D.

    2013-05-01

    located close to tectonic faults, while "I" is in the center of the basin with its quite thick layer of sediments. Axial section observations of spatial inhomogeneities of electric field and Radon emanation were set along and across the Tunkin Basin. Observation points were set 3 to 10 km apart depending on the local relief. Each point was registering for 60 min under the conditions of "good" weather. There were analysed changes in mean strength of electric field and Radon volumetric activity as a function of distance along the axial section. It was found out that volumetric activity and electric field strength change in phase opposition - radon volumetric activity increase results in more intense ionization in near-surface atmosphere and consequently to decrease in the electric field strength. The concentration of Radon in subsoil atmosphere increases, and electric field strength decreases when approaching to rift zones rimming the Tunkin Basin from North and South. The results of axial section observations can be successfully used when mapping geological inhomogeneities in the Earth's crust. The research was done with financial support of RFBR, project# 12-05-00578

  7. Surface science and electrochemical studies of metal-modified carbides for fuel cells and hydrogen production

    Science.gov (United States)

    Kelly, Thomas Glenn

    Carbides of the early transition metals have emerged as low-cost catalysts that are active for a wide range of reactions. The surface chemistry of carbides can be altered by modifying the surface with small amounts of admetals. These metal-modified carbides can be effective replacements for Pt-based bimetallic systems, which suffer from the drawbacks of high cost and low thermal stability. In this dissertation, metal-modified carbides were studied for reactions with applications to renewable energy technologies. It is demonstrated that metal-modified carbides possess high activity for alcohol reforming and electrochemical hydrogen production. First, the surface chemistry of carbides towards alcohol decomposition is studied using density functional theory (DFT) and surface science experiments. The Vienna Ab initio Simulation Package (VASP) was used to calculate the binding energies of alcohols and decomposition intermediates on metal-modified carbides. The calculated binding energies were then correlated to reforming activity determined experimentally using temperature programmed desorption (TPD). In the case of methanol decomposition, it was found that tungsten monocarbide (WC) selectively cleaved the C-O bond to produce methane. Upon modifying the surface with a single layer of metal such as Ni, Pt, or Rh, the selectivity shifted towards scission of the C-H bonds while leaving the C-O bond intact, producing carbon monoxide (CO) and H2. High resolution energy loss spectroscopy (HREELS) was used to examine the bond breaking sequence as a function of temperature. From HREELS, it was shown that the surfaces followed an activity trend of Rh > Ni > Pt. The Au-modified WC surface possessed too low of a methanol binding energy, and molecular desorption of methanol was the most favorable pathway on this surface. Next, the ability of Rh-modified WC to break the C-C bond of C2 and C3 alcohols was demonstrated. HREELS showed that ethanol decomposed through an acetaldehyde

  8. Radon emanation of rock and soil samples: A tool for stratigraphy, geology, geophysical modelling and radon health hazard

    Science.gov (United States)

    Girault, Frédéric; Koirala, Bharat P.; Bhattarai, Mukunda; Rajaure, Sudhir; Richon, Patrick; Perrier, Frédéric

    2010-05-01

    Radium-226, the mother of radon-222, with a half-life of 1600 years, is intrinsically present in all the rocks and soils in variable amount. However, a small part only of the radium atoms is able to produce radon atoms in the porous media of the rock allowing this radon to escape the rock media through the pore space. This fraction of radium is referred to as the radon source term in rocks or soils, and is usually called the effective radium concentration (ECRa). This parameter is expressed in Bq kg-1, where CRa is the radium-226 concentration and E the emanation coefficient. Considering a sample, it is not possible to estimate its ECRa value a priori. Therefore, this parameter has to be measured in the laboratory. The method in the laboratory to obtain ECRa values is based on the measurement of the concentration of radon in the inner air of a hermetically sealed container in which one rock or one soil sample was previously placed. In order to measure this radon concentration, Lucas scintillation flasks were used, and their radon content counted by a photomultiplier (Stoulos et al., Journal of Environmental Radioactivity, 2003). This method was compared in detail with another method using SSNTD (Solid-State Nuclear Track Detector). Detailed investigations have been carried out, including systematic effects such as the shape or volume of container, mass and preparation method of the sample, using a large number of rock, soil and building material samples (more than 800) collected in France and Nepal. Preliminary results will be given based on this data set. With such a large sample, some effects of intrinsic and external factors on the measurement technique and on the obtained results could also be accurately studied: the effect of atmospheric pressure, of the ambient temperature, or of the water content of the sample. ECRa measurements appear to be particularly useful for human health hazards study on a considered natural site, as well as for other applications

  9. Surface and interface sciences of Li-ion batteries. -Research progress in electrode-electrolyte interface-

    Science.gov (United States)

    Minato, Taketoshi; Abe, Takeshi

    2017-12-01

    The application potential of Li-ion batteries is growing as demand increases in different fields at various stages in energy systems, in addition to their conventional role as power sources for portable devices. In particular, applications in electric vehicles and renewable energy storage are increasing for Li-ion batteries. For these applications, improvements in battery performance are necessary. The Li-ion battery produces and stores electric power from the electrochemical redox reactions between the electrode materials. The interface between the electrodes and electrolyte strongly affects the battery performance because the charge transfer causing the electrode redox reaction begins at this interface. Understanding of the surface structure, electronic structure, and chemical reactions at the electrode-electrolyte interface is necessary to improve battery performance. However, the interface is located between the electrode and electrolyte materials, hindering the experimental analysis of the interface; thus, the physical properties and chemical processes have remained poorly understood until recently. Investigations of the physical properties and chemical processes at the interface have been performed using advanced surface science techniques. In this review, current knowledge and future research prospects regarding the electrode-electrolyte interface are described for the further development of Li-ion batteries.

  10. Innovations from the “ivory tower”: Wilhelm Barthlott and the paradigm shift in surface science

    Directory of Open Access Journals (Sweden)

    Christoph Neinhuis

    2017-02-01

    Full Text Available This article is mainly about borders that have tremendous influence on our daily life, although many of them exist and act mostly unrecognized. In this article the first objective will be to address more generally the relation between university and society or industry, borders within universities, borders in thinking and the huge amount of misunderstandings and losses resulting from these obvious or hidden borders. In the second part and in more detail, the article will highlight the impact of the research conducted by Wilhelm Barthlott throughout his scientific career during which not only one border was removed, shifted or became more penetrable. Among the various fields of interest not mentioned here (e.g., systematics of Cactaceae, diversity and evolution of epiphytes, the unique natural history of isolated rocky outcrops called inselbergs, or the global distribution of biodiversity, plant surfaces and especially the tremendous diversity of minute structures on leaves, fruits, seeds and other parts of plants represent a common thread through 40 years of scientific career of Wilhelm Barthlott. Based on research that was regarded already old-fashioned in the 1970s and 1980s, systematic botany, results and knowledge were accumulated that, some 20 years later, initiated a fundamental turnover in how surfaces were recognized not only in biology, but even more evident in materials science.

  11. Surface science approach to Pt/carbon model catalysts: XPS, STM and microreactor studies

    Science.gov (United States)

    Motin, Abdul Md.; Haunold, Thomas; Bukhtiyarov, Andrey V.; Bera, Abhijit; Rameshan, Christoph; Rupprechter, Günther

    2018-05-01

    Pt nanoparticles supported on carbon are an important technological catalyst. A corresponding model catalyst was prepared by physical vapor deposition (PVD) of Pt on sputtered HOPG (highly oriented pyrolytic graphite). The carbon substrate before and after sputtering as well as the Pt/HOPG system before and after Pt deposition and annealing were examined by XPS and STM. This yielded information on the surface density of defects, which serve as nucleation centres for Pt, and on the size distribution (mean size/height) of the Pt nanoparticles. Two different model catalysts were prepared with mean sizes of 2.0 and 3.6 nm, both turned out to be stable upon UHV-annealing to 300 °C. After transfer into a UHV-compatible flow microreactor and subsequent cleaning in UHV and under mbar pressure, the catalytic activity of the Pt/HOPG model system for ethylene hydrogenation was examined under atmospheric pressure flow conditions. This enabled to determine temperature-dependent conversion rates, turnover frequencies (TOFs) and activation energies. The catalytic results obtained are in line with the characteristics of technological Pt/C, demonstrating the validity of the current surface science based model catalyst approach.

  12. sup 2 sup 2 sup 6 Ra measurement in Mo, Cd and Nd sub 2 O sub 3 samples with the emanation method

    CERN Document Server

    Barabash, A S; Kornoukhov, V N; Orekhov, I V

    2001-01-01

    Measurements of sup 2 sup 2 sup 6 Ra content in materials and chemical reagents used to construct the double beta decay sources in the NEMO-3 experiment have been done with the emanation method technique. Three different radon emanation technologies were used in these studies. The first was the 'traditional' method of dissolving the sample. The second was an extraction of Rn from a melted sample and finally a technique of heating fine-grained powder was used. It is shown that there is good agreement of the data received with the emanation method and low background high purity germanium detectors. The sensitivity of this method is 0.02 mBq/l of solution (for the 'standard' emanation method) or 0.02 mBq/kg (for methods in which radon is extracted from a powder or melt).

  13. Radiofrequency Ablation of an Atrial Tachycardia Emanating From the Non-coronary Aortic Cusp Guided by an Electroanatomic Navigation System

    Directory of Open Access Journals (Sweden)

    Agustin Bortone

    2010-02-01

    Full Text Available We report on an atrial tachycardia (AT, emanating from the non-coronary (NC aortic cusp, ablated with the aid of an electro-anatomical navigation system. In this setting, the electrocardiographic, electrophysiologic (EP, anatomical, and ablative considerations are discussed.Although NC aortic cusp focal ATs are an uncommon EP finding, their ablation is effective and safe, especially from an atrio-ventricular (AV conductive point of view. This origin of AT must be invoked and systematically disclosed when a peri-AV nodal AT origin is suspected, in order to avoid a potentially harmful energy application at the vicinity of the AV conductive tissue.

  14. Correlation between radon gas emanation and porosity in ornamental stones; Correlacao entre emanacao de gas radonio e porosidade de rochas ornamentais do Estado do Ceara, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo, Leiliane Rufina Pereira de; Artur, Antonio Carlos; Bonotto, Daniel Marcos, E-mail: leili_ane@hotmail.com, E-mail: acartur@rc.unesp.br, E-mail: dbonotto@rc.unesp.br [Universidade Estadual Paulista (UNESP), Rio Claro, SP (Brazil); Nogueira Neto, Jose de Araujo, E-mail: nogueira@ufc.br [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Geologia

    2014-01-15

    This article makes correlations between levels of gas {sup 222}Rn emanation and corresponding porosity for thirteen samples of granitic rocks ornamental state of Ceara. For both determinations of physical indexes (bulk density, apparent porosity and water absorption, the levels of U, monitoring emanation of radon gas are made for a period of 25 days in confinement conditions of the samples under vacuum and petrographic studies of the characteristics rocks, with emphasis on the microfissural state. The sampled rocks provided low values of radon gas emanation between U 0,2 ppm and 13.6 ppm. The correlations between the various results show that the microporous network of the rock is determinant in the rate of emanation of radon gas, overlapping, including the influence of own levels of U present in the rocks. The results also show that the amount of radon gas emanating from the rock is small enough compared to the decay caused by the amount of {sup 238}U. The proposition of gas emanating relative to the total generated by rocks ranging between 0.4% and a maximum of 4.2%. (author)

  15. FOREWORD Applications of Data Sciences

    Indian Academy of Sciences (India)

    In this age of BigData, there is increasing interest in analysing data emanating from heterogenous sources. Developing statistical and computational techniques for such data analysis problems is the focus of the emerging area of Data Science. The special section in this issue of Sadhana tries to bring together some of the ...

  16. Measurements of size distributions of radon progeny for improved quantification of the lung cancer risk emanating from exposure to radon decay products

    International Nuclear Information System (INIS)

    Haninger, T.

    1997-01-01

    A major issue in radiation protection is to protect the population from the harmful effects of exposure to radon and radon progeny. Quantification of the lung cancer risk emanating from exposure to radon decay products in residential and working environments poses problems, as epidemiologic studies yield information deviating from the results obtained by the indirect method of assessment based on dosimetric respiratory tract models. One important task of the publication here was to characterize the various exposure conditions and to quantify uncertainties that may result from application of the ''dose conversion convention''. A special aerosol spectrometer was therefore designed and built in order to measure the size distributions of the short-lived radon decay products in the range between 0.5 nm and 10 000 nm. The aerosol spectrometer consists of a three-step diffusion battery with wire nets, an 11-step BERNER impactor, and a detector system with twelve large-surface proportional detectors. From the measured size distributions, dose conversion coefficients, E/P eq , were calculated using the PC software RADEP; the RADEP program was developed by BIRCHALL and JAMES and is based on the respiratory tract model of the ICRP. The E/P eq coefficients indicate the effective dose E per unit exposure P eq to radon decay products. (orig./CB) [de

  17. From SU(3) to gravity: Festschrift in honor of Yuval Ne'eman

    International Nuclear Information System (INIS)

    Gotsman, E.; Tauber, G.

    1985-01-01

    This book contains papers covering the following topics: groups and gauges, particles, science policy, astronomy and astrophysics, and gravity and supergravity. Some of the titles of the papers include: General covariance and the passive equations of physics, Symmetry of wave functions for ''like'' unstable particles, Analytical calculations for masses in Hamiltonian lattice theories, on plane waves and nullicles, Descrete Yang-Milles theories, Refugee scientists and nuclear energy, QCD inequalities, Speculation in cosmology, and an alternative to general relativity

  18. From Sakata model to Goldberg-Ne'eman quarks and Nambu QCD phenomenology and 'right' and 'wrong' experiments

    International Nuclear Information System (INIS)

    Lipkin, Harry J.

    2007-01-01

    The basic theoretical milestones were the Sakata SU(3) symmetry, the Goldberg-Ne'eman composite model with SU(3) triplets having baryon number (1/3) and the Nambu color gauge Lagrangian. The transition was led in right and wrong directions by experiments interpreted by phenomenology. A 'good' experiment on p-bar p annihilation at rest showed that the Sakata model predictions disagreed with experiment. A 'bad' experiment prevented the use of the Goldberg-Ne'eman triplet model to predict the existence and masses of the Ξ * and Ω - . More 'good' experiments revealed the existence and mass of the Ξ * and the Ω - and the absence of positive strangeness baryon resonances, thus confirming the 'tenfold way'. Further 'good experiments' revealed the existence of the vector meson nonet, SU(3) breaking with singlet-octet mixing and the suppression of the φ → ρπ decay. These led to the quark triplet model. The paradox of peculiar statistics then arose as the Δ ++ and Ω - contained three identical spin-1/2 fermions coupled symmetrically to spin (3/2). This led to color and the Nambu QCD. The book 'Lie Groups for Pedestrians' used the Sakata model with the name 'sakaton' for the pnΛ triplet to teach the algebra of SU(3) to particle physicists in the U.S. and Europe who knew no group theory. The Sakata model had a renaissance in hypernuclear physics in the 1970's. (author)

  19. From Sakata model to Goldberg-Ne'eman quarks and Nambu QCD phenomenology and 'right' and 'wrong' experiments

    International Nuclear Information System (INIS)

    Lipkin, H. J.

    2007-01-01

    The basic theoretical milestones were the Sakata SU(3) symmetry, the Goldberg-Ne'eman composite model with SU(3) triplets having baryon number (1/3) and the Nambu color gauge Lagrangian. The transition was led in right and wrong directions by experiments interpreted by phenomenology. A 'good' experiment on (bar p)p annihilation at rest showed that the Sakata model predictions disagreed with experiment. A 'bad' experiment prevented the use of the Goldberg-Ne'eman triplet model to predict the existence and masses of the of the Ξ and (Omega) - . More 'good' experiments revealed the existence and mass of the Ξ* and the (Omega) - and the absence of positive strangeness baryon resonances, thus confirming the 'tenfold way'. Further 'good experiments' revealed the existence of the vector meson nonet, SU(3) breaking with singlet-octet mixing and the suppression of the φ → ρ π decay. These led to the quark triplet model. The paradox of peculiar statistics then arose as the Δ ++ and (Omega) - contained three identical spin-1/2 fermions coupled symmetrically to spin (3/2). This led to color and the Nambu QCD. The book 'Lie Groups for Pedestrians' used the Sakata model with the name 'sakaton' for the Λ triplet to teach the algebra of SU(3) to particle physicists in the U.S. and Europe who knew no group theory. The Sakata model had a renaissance in hypernuclear physics in the 1970's

  20. A surface science compatible epifluorescence microscope for inspection of samples under ultra high vacuum and cryogenic conditions.

    Science.gov (United States)

    Marquardt, Christian; Paulheim, Alexander; Rohbohm, Nils; Merkel, Rudolf; Sokolowski, Moritz

    2017-08-01

    We modified an epi-illumination light microscope and mounted it on an ultra high vacuum chamber for investigating samples used in a surface science experiment. For easy access and bake out, all optical components are placed outside the vacuum and the sample is imaged through a glass window. The microscope can be operated in reflection brightfield or epifluorescence mode to image the sample surface or fluorescent dye molecules adsorbed on it. The homemade sample mounting was made compatible for the use under the microscope; sample temperatures as low as 6 K can be achieved. The performance of the microscope is demonstrated on two model samples: Brightfield-images of a well-prepared Ag(100) surface show a macroscopic corrugation of the surface, although low energy electron diffraction data indicate a highly ordered crystalline surface. The surface shows macroscopic protrusions with flat regions, about 20-200 μm in diameter, in between. Fluorescence images of diluted 3,4,9,10-perylene tetracarboxylicacid dianhydride (PTCDA) molecules adsorbed on an ultrathin epitaxial KCl film on the Ag(100) surface show a shading effect at surface protrusions due to an inclined angle of incidence of the PTCDA beam during deposition. For some preparations, the distribution of the fluorescence intensity is inhomogeneous and shows a dense network of bright patches about 5 μm in diameter related to the macroscopic corrugation of the surface. We propose that such a light microscope can aid many surface science experiments, especially those dealing with epitaxial growth or fluorescent materials.

  1. A surface science compatible epifluorescence microscope for inspection of samples under ultra high vacuum and cryogenic conditions

    Science.gov (United States)

    Marquardt, Christian; Paulheim, Alexander; Rohbohm, Nils; Merkel, Rudolf; Sokolowski, Moritz

    2017-08-01

    We modified an epi-illumination light microscope and mounted it on an ultra high vacuum chamber for investigating samples used in a surface science experiment. For easy access and bake out, all optical components are placed outside the vacuum and the sample is imaged through a glass window. The microscope can be operated in reflection brightfield or epifluorescence mode to image the sample surface or fluorescent dye molecules adsorbed on it. The homemade sample mounting was made compatible for the use under the microscope; sample temperatures as low as 6 K can be achieved. The performance of the microscope is demonstrated on two model samples: Brightfield-images of a well-prepared Ag(100) surface show a macroscopic corrugation of the surface, although low energy electron diffraction data indicate a highly ordered crystalline surface. The surface shows macroscopic protrusions with flat regions, about 20-200 μm in diameter, in between. Fluorescence images of diluted 3,4,9,10-perylene tetracarboxylicacid dianhydride (PTCDA) molecules adsorbed on an ultrathin epitaxial KCl film on the Ag(100) surface show a shading effect at surface protrusions due to an inclined angle of incidence of the PTCDA beam during deposition. For some preparations, the distribution of the fluorescence intensity is inhomogeneous and shows a dense network of bright patches about 5 μm in diameter related to the macroscopic corrugation of the surface. We propose that such a light microscope can aid many surface science experiments, especially those dealing with epitaxial growth or fluorescent materials.

  2. Season Spotter: Using Citizen Science to Validate and Scale Plant Phenology from Near-Surface Remote Sensing

    Directory of Open Access Journals (Sweden)

    Margaret Kosmala

    2016-09-01

    Full Text Available The impact of a rapidly changing climate on the biosphere is an urgent area of research for mitigation policy and management. Plant phenology is a sensitive indicator of climate change and regulates the seasonality of carbon, water, and energy fluxes between the land surface and the climate system, making it an important tool for studying biosphere–atmosphere interactions. To monitor plant phenology at regional and continental scales, automated near-surface cameras are being increasingly used to supplement phenology data derived from satellite imagery and data from ground-based human observers. We used imagery from a network of phenology cameras in a citizen science project called Season Spotter to investigate whether information could be derived from these images beyond standard, color-based vegetation indices. We found that engaging citizen science volunteers resulted in useful science knowledge in three ways: first, volunteers were able to detect some, but not all, reproductive phenology events, connecting landscape-level measures with field-based measures. Second, volunteers successfully demarcated individual trees in landscape imagery, facilitating scaling of vegetation indices from organism to ecosystem. And third, volunteers’ data were used to validate phenology transition dates calculated from vegetation indices and to identify potential improvements to existing algorithms to enable better biological interpretation. As a result, the use of citizen science in combination with near-surface remote sensing of phenology can be used to link ground-based phenology observations to satellite sensor data for scaling and validation. Well-designed citizen science projects targeting improved data processing and validation of remote sensing imagery hold promise for providing the data needed to address grand challenges in environmental science and Earth observation.

  3. A maximally particle-hole asymmetric spectrum emanating from a semi-Dirac point

    Science.gov (United States)

    Quan, Yundi; Pickett, Warren E.

    2018-02-01

    Tight binding models have proven an effective means of revealing Dirac (massless) dispersion, flat bands (infinite mass), and intermediate cases such as the semi-Dirac (sD) dispersion. This approach is extended to a three band model that yields, with chosen parameters in a two-band limit, a closed line with maximally asymmetric particle-hole dispersion: infinite mass holes, zero mass particles. The model retains the sD points for a general set of parameters. Adjacent to this limiting case, hole Fermi surfaces are tiny and needle-like. A pair of large electron Fermi surfaces at low doping merge and collapse at half filling to a flat (zero energy) closed contour with infinite mass along the contour and enclosing no carriers on either side, while the hole Fermi surface has shrunk to a point at zero energy, also containing no carriers. The tight binding model is used to study several characteristics of the dispersion and density of states. The model inspired generalization of sD dispersion to a general  ± \\sqrt{k_x2n +k_y2m} form, for which analysis reveals that both n and m must be odd to provide a diabolical point with topological character. Evolution of the Hofstadter spectrum of this three band system with interband coupling strength is presented and discussed.

  4. Surface-water quality-assurance plan for the U.S. Geological Survey Washington Water Science Center

    Science.gov (United States)

    Mastin, Mark C.

    2016-02-19

    This Surface-Water Quality-Assurance Plan documents the standards, policies, and procedures used by the U.S. Geological Survey Washington Water Science Center (WAWSC) for activities related to the collection, processing, storage, analysis, and publication of surface-water data. This plan serves as a guide to all WAWSC personnel involved in surface-water data activities, and changes as the needs and requirements of the WAWSC change. Regular updates to this plan represent an integral part of the quality-assurance process. In the WAWSC, direct oversight and responsibility by the hydrographer(s) assigned to a surface-water station, combined with team approaches in all work efforts, assure highquality data, analyses, reviews, and reports for cooperating agencies and the public.

  5. Ethers on Si(001): A prime example for the common ground between surface science and molecular organic chemistry

    KAUST Repository

    Pecher, Lisa

    2017-09-15

    Using computational chemistry, we show that the adsorption of ether molecules on Si(001) under ultra-high vacuum conditions can be understood with textbook organic chemistry. The two-step reaction mechanism of (1) dative bond formation between the ether oxygen and a Lewis acidic surface atom and (2) a nucleophilic attack of a nearby Lewis basic surface atom is analysed in detail and found to mirror the acid-catalysed ether cleavage in solution. The O-Si dative bond is found to be the strongest of its kind and reactivity from this state defies the Bell-Evans-Polanyi principle. Electron rearrangement during the C-O bond cleavage is visualized using a newly developed bonding analysis method, which shows that the mechanism of nucleophilic substitutions on semiconductor surfaces is identical to molecular chemistry SN2 reactions. Our findings thus illustrate how the fields of surface science and molecular chemistry can mutually benefit and unexpected insight can be gained.

  6. science

    International Development Research Centre (IDRC) Digital Library (Canada)

    David Spurgeon

    green revolution". — seemed to confirm the value of science and technology to international development. Yet studies showed that, at that time, only about two percent of ... gap in science and technology between the Third World and the industrial- ..... Finance; Treasury Board; Industry, Trade and Commerce; Agriculture;.

  7. Radon emanation over an orebody: search for long-distance transport of radon

    International Nuclear Information System (INIS)

    Fleischer, R.L.; Hart, H.R. Jr.; Mogro-Campero, A.

    1980-01-01

    Discovery of subsurface uranium ore could be facilitated by recognition of measurable concentrations of the radioactive gas 222 Rn near the surface of the earth. Integrated measurements made over several weeks' time show promise of giving greater reproducibility than short-term measurements, which are more subject to meteorological variability. Improved methods of integrated randon measurements-free of 220 Rn, thermal-track fading, and mositure-condensation effects-allow readings that generally are highly stable over time. Sixteen kilometers north of Thoreau, New Mexico, reading taken at 60-cm depth over a 13-month interval for 55 positions give different-but nearly constant-monthly readings at each position; the typical standard deviation was 22 percent. Superimposed on that stable pattern have been three periods during which spatially grouped radon readings increased by a factor of two or more over their normal values. The simplest tenable description of the increases is sporadic puffs of upflowing gas, originating from unknown depths. The measurements are consistent with an upward velocity of flow of about 10 -3 cm/s (centimeters per second). If this velocity is maintained to depth, it is still insufficient to transport detectable amounts of radon from the orebody at 90-m depth, but it would be sufficient to reveal ore at 50 m or less. Downhole measurements of permeability yield values generally too low for signals to be delivered from the orebody by any of the mechanisms already modeled

  8. Study of the influence of porosity on the radon emanation coefficient in different building material samples by combining the SSNTD technique with Monte Carlo simulations

    CERN Document Server

    Misdaq, M A; Ktata, A

    1998-01-01

    Radon alpha-activities per unit volume have been measured inside and outside different building material samples by using CR-39 and LR-115 type II solid state nuclear track detectors (SSNTD). Radon emanation coefficients of the studied building materials have been evaluated. The porosities of the building material samples studied have been determined by using a Monte Carlo calculational method adapted to the experimental conditions and compared with data obtained by the Archimedes's method. The influence of the building material porosity on the radon emanation coefficient has been investigated.

  9. Seventh BES (Basic Energy Sciences) catalysis and surface chemistry research conference

    Energy Technology Data Exchange (ETDEWEB)

    1990-03-01

    Research programs on catalysis and surface chemistry are presented. A total of fifty-seven topics are included. Areas of research include heterogeneous catalysis; catalysis in hydrogenation, desulfurization, gasification, and redox reactions; studies of surface properties and surface active sites; catalyst supports; chemical activation, deactivation; selectivity, chemical preparation; molecular structure studies; sorption and dissociation. Individual projects are processed separately for the data bases. (CBS)

  10. Seventh BES [Basic Energy Sciences] catalysis and surface chemistry research conference

    International Nuclear Information System (INIS)

    1990-03-01

    Research programs on catalysis and surface chemistry are presented. A total of fifty-seven topics are included. Areas of research include heterogeneous catalysis; catalysis in hydrogenation, desulfurization, gasification, and redox reactions; studies of surface properties and surface active sites; catalyst supports; chemical activation, deactivation; selectivity, chemical preparation; molecular structure studies; sorption and dissociation. Individual projects are processed separately for the data bases

  11. Constraining the JULES land-surface model for different land-use types using citizen-science generated hydrological data

    Science.gov (United States)

    Chou, H. K.; Ochoa-Tocachi, B. F.; Buytaert, W.

    2017-12-01

    Community land surface models such as JULES are increasingly used for hydrological assessment because of their state-of-the-art representation of land-surface processes. However, a major weakness of JULES and other land surface models is the limited number of land surface parameterizations that is available. Therefore, this study explores the use of data from a network of catchments under homogeneous land-use to generate parameter "libraries" to extent the land surface parameterizations of JULES. The network (called iMHEA) is part of a grassroots initiative to characterise the hydrological response of different Andean ecosystems, and collects data on streamflow, precipitation, and several weather variables at a high temporal resolution. The tropical Andes are a useful case study because of the complexity of meteorological and geographical conditions combined with extremely heterogeneous land-use that result in a wide range of hydrological responses. We then calibrated JULES for each land-use represented in the iMHEA dataset. For the individual land-use types, the results show improved simulations of streamflow when using the calibrated parameters with respect to default values. In particular, the partitioning between surface and subsurface flows can be improved. But also, on a regional scale, hydrological modelling was greatly benefitted from constraining parameters using such distributed citizen-science generated streamflow data. This study demonstrates the modelling and prediction on regional hydrology by integrating citizen science and land surface model. In the context of hydrological study, the limitation of data scarcity could be solved indeed by using this framework. Improved predictions of such impacts could be leveraged by catchment managers to guide watershed interventions, to evaluate their effectiveness, and to minimize risks.

  12. Seasonal emanation of radon at Ghuttu, northwest Himalaya: Differentiation of atmospheric temperature and pressure influences.

    Science.gov (United States)

    Kamra, Leena

    2015-11-01

    Continuous monitoring of radon along with meteorological parameters has been carried out in a seismically active area of Garhwal region, northwest Himalaya, within the frame work of earthquake precursory research. Radon measurements are carried out by using a gamma ray detector installed in the air column at a depth of 10m in a 68m deep borehole. The analysis of long time series for 2006-2012 shows strong seasonal variability masked by diurnal and multi-day variations. Isolation of a seasonal cycle by minimising short-time by 31 day running average shows a strong seasonal variation with unambiguous dependence on atmospheric temperature and pressure. The seasonal characteristics of radon concentrations are positively correlated to atmospheric temperature (R=0.95) and negatively correlated to atmospheric pressure (R=-0.82). The temperature and pressure variation in their annual progressions are negatively correlated. The calculations of partial correlation coefficient permit us to conclude that atmospheric temperature plays a dominant role in controlling the variability of radon in borehole, 71% of the variability in radon arises from the variation in atmospheric temperature and about 6% of the variability is contributed by atmospheric pressure. The influence of pressure variations in an annual cycle appears to be a pseudo-effect, resulting from the negative correlation between temperature and pressure variations. Incorporation of these results explains the varying and even contradictory claims regarding the influence of the pressure variability on radon changes in the published literature. Temperature dependence, facilitated by the temperature gradient in the borehole, controls the transportation of radon from the deep interior to the surface. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Seasonal emanation of radon at Ghuttu, northwest Himalaya: Differentiation of atmospheric temperature and pressure influences

    International Nuclear Information System (INIS)

    Kamra, Leena

    2015-01-01

    Continuous monitoring of radon along with meteorological parameters has been carried out in a seismically active area of Garhwal region, northwest Himalaya, within the frame work of earthquake precursory research. Radon measurements are carried out by using a gamma ray detector installed in the air column at a depth of 10 m in a 68 m deep borehole. The analysis of long time series for 2006–2012 shows strong seasonal variability masked by diurnal and multi-day variations. Isolation of a seasonal cycle by minimising short-time by 31 day running average shows a strong seasonal variation with unambiguous dependence on atmospheric temperature and pressure. The seasonal characteristics of radon concentrations are positively correlated to atmospheric temperature (R=0.95) and negatively correlated to atmospheric pressure (R=−0.82). The temperature and pressure variation in their annual progressions are negatively correlated. The calculations of partial correlation coefficient permit us to conclude that atmospheric temperature plays a dominant role in controlling the variability of radon in borehole, 71% of the variability in radon arises from the variation in atmospheric temperature and about 6% of the variability is contributed by atmospheric pressure. The influence of pressure variations in an annual cycle appears to be a pseudo-effect, resulting from the negative correlation between temperature and pressure variations. Incorporation of these results explains the varying and even contradictory claims regarding the influence of the pressure variability on radon changes in the published literature. Temperature dependence, facilitated by the temperature gradient in the borehole, controls the transportation of radon from the deep interior to the surface. - Highlights: • Seasonal variability of radon in borehole. • Influence of atmospheric temperature and pressure on radon variability. • Partial correlation coefficient.

  14. COMETARY SCIENCE. CHO-bearing organic compounds at the surface of 67P/Churyumov-Gerasimenko revealed by Ptolemy.

    Science.gov (United States)

    Wright, I P; Sheridan, S; Barber, S J; Morgan, G H; Andrews, D J; Morse, A D

    2015-07-31

    The surface and subsurface of comets preserve material from the formation of the solar system. The properties of cometary material thus provide insight into the physical and chemical conditions during their formation. We present mass spectra taken by the Ptolemy instrument 20 minutes after the initial touchdown of the Philae lander on the surface of comet 67P/Churyumov-Gerasimenko. Regular mass distributions indicate the presence of a sequence of compounds with additional -CH2- and -O- groups (mass/charge ratios 14 and 16, respectively). Similarities with the detected coma species of comet Halley suggest the presence of a radiation-induced polymer at the surface. Ptolemy measurements also indicate an apparent absence of aromatic compounds such as benzene, a lack of sulfur-bearing species, and very low concentrations of nitrogenous material. Copyright © 2015, American Association for the Advancement of Science.

  15. Multiwavelength study of 20 jets that emanate from the periphery of active regions

    Science.gov (United States)

    Mulay, Sargam M.; Tripathi, Durgesh; Del Zanna, Giulio; Mason, Helen

    2016-05-01

    Aims: We present a multiwavelength analysis of 20 EUV jets which occurred at the periphery of active regions close to sunspots. We discuss the physical parameters of the jets and their relation with other phenomena such as Hα surges, nonthermal type-III radio bursts and hard X-ray (HXR) emission. Methods: These jets were observed between August 2010 and June 2013 by the Atmospheric Imaging Assembly (AIA) instrument that is onboard the Solar Dynamic Observatory (SDO). We selected events that were observed on the solar disk within +/-60° latitude. Using AIA wavelength channels that are sensitive to coronal temperatures, we studied the temperature distribution in the jets using the line of sight (LOS) differential emission measure (DEM) technique. We also investigated the role of the photospheric magnetic field using the LOS magnetogram data from the Helioseismic and Magnetic Imager (HMI) onboard SDO. Results: It has been observed that most of the jets originated from the western periphery of active regions. Their lifetimes range from 5 to 39 min with an average of 18 min and their velocities range from 87 to 532 km s-1 with an average of 271 km s-1. All the jets are co-temporally associated with Hα surges. Most of the jets are co-temporal with nonthermal type-III radio bursts observed by the Wind/WAVES spacecraft in the frequency range from 20 kHz to 13 MHz. We confirm the source region of these bursts using the potential field source surface (PFSS) technique. Using Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) observations, we found that half of the jets produced HXR emission and they often shared the same source region as the HXR emission (6-12 keV). Ten out of 20 events showed that the jets originated in a region of flux cancellation and six jets in a region of flux emergence. Four events showed flux emergence and then cancellation during the jet evolution. DEM analyses showed that for most of the spires of the jets, the DEM peaked at around log

  16. Surface science approach to heterogeneous catalysis: CO hydrogenation on transition metals

    Science.gov (United States)

    Bonzel, H. P.; Krebs, H. J.

    1982-05-01

    Modern surface sensitive electron spectroscopies and other surface analytical techniques have in recent years been extensively applied to the study of H 2 and CO adorption on transition metals. This work has now been extended to include the heterogeneous reaction between adsorbed H 2 and CO on these metals. The combination of surface analysis (carried out under ultra-high vacuum conditions) and reaction rate measurements in the range of 100 mbar to 1 bar total pressure is being practiced. This approach yields information on changes of the surface composition of the catalyst as well as data on reaction kinetics and the possible time dependence of the reaction rate. Low surface area samples — either single or polycrystalline - are used for these studies. In the present paper the results obtained by this approach will be reviewed and discussed in the light of the adsorption data. Recent advances in the direction of studying either poisoned or promoted catalytic surfaces will also be mentioned.

  17. Multifunctional magnetite and silica-magnetite nanoparticles: Synthesis, surface activation and applications in life sciences

    International Nuclear Information System (INIS)

    Campo, Aranzazu del; Sen, Tapas; Lellouche, Jean-Paul; Bruce, Ian J.

    2005-01-01

    A method for the introduction of amine groups onto the surface of magnetite and silica-coated magnetite nanoparticles has been established based on the condensation of aminopropyltriethoxysilane. Amine-modified particles were grafted with an oligonucleotide and used in the capture of a complimentary sequence. The particles' efficiency at capture was observed to correlate directly with amine group surface density

  18. Surface enhanced Raman spectroscopy: A review of recent applications in forensic science

    Science.gov (United States)

    Fikiet, Marisia A.; Khandasammy, Shelby R.; Mistek, Ewelina; Ahmed, Yasmine; Halámková, Lenka; Bueno, Justin; Lednev, Igor K.

    2018-05-01

    Surface enhanced Raman spectroscopy has many advantages over its parent technique of Raman spectroscopy. Some of these advantages such as increased sensitivity and selectivity and therefore the possibility of small sample sizes and detection of small concentrations are invaluable in the field of forensics. A variety of new SERS surfaces and novel approaches are presented here on a wide range of forensically relevant topics.

  19. On the implications of the Surface Water and Ocean Topography (SWOT) mission for hydrologic science and applications (Invited)

    Science.gov (United States)

    Lettenmaier, D. P.

    2010-12-01

    The SWOT mission will provide surface water elevation and extent information with unprecedented accuracy and spatial resolution globally. All of the implications of thedata that SWOT will produce for the hydrologic science and applications communities are not yet apparent. The SWOT data will, however, certainly offer groundbreaking opportunities for estimation of two key terms in the land surface water budget: surface water storage (in almost all water bodies with surface area exceeding about 1 km2) and derived discharge for many of the world’s large rivers (widths greater than roughly 100-250 m). Among just a few of the science questions that the observations should allow us to address are a) what are the dynamics of floods and overbank flows in large rivers? b) what is the contribution of long-term, seasonal, and interannual storage in reservoirs, lakes, and wetlands to sea level? c) what is the magnitude of surface water storage changes at seasonal to decadal time scales and continental spatial scales relative to soil moisture and groundwater? d) what will be the implications of SWOT-based estimates of reservoir storage and storage change to the management of transboundary rivers? These quite likely are among just a few of the questions that SWOT will help elucidate. Others no doubt will arise from creative analyses of SWOT data in combination with data from other missions I conclude with a discussion of mechanisms that will help foster a community to investigate these and other questions, and the implications of a SWOT data policy.

  20. Analysing the Onus Issue in Dismissals Emanating from the Enforcement of Unilateral Changes to Conditions of Employment

    Directory of Open Access Journals (Sweden)

    I Tshoose

    2011-12-01

    Full Text Available The main objective of this article is to analyse the issue of onus emanating from the enforcement of unilateral changes to conditions of employment. At the heart of the controversy that has faced the Labour Appeal Court was how to interpret dismissals that appear to be based on operational requirements, and yet at the same time, such dismissals also appear to have the effect of compelling an employee to accept a demand in respect of a matter of mutual interest between the employer and the employee.The core section in the Labour Relations Act 66 of 1995 relating to disputes of this nature is section 187(1(c of the Act, and the central enquiry to such disputes is whether they are automatically unfair or operationally justifiable. The fine line that determines whether a dismissal is acceptable or not merits an analysis of the overall onus that faces an employer and employee. This analysis is the focus of the article, which deals predominantly with procedural issues. The issue relating to the promotion of collective bargaining will be assessed against the right to dismiss, based on an analysis of the situation in South Africa, and a brief comparison with the situations in the United Kingdom and Canada. Thereafter, recommendations are made to the South African legislature.

  1. Spectral Feature Analysis of Minerals and Planetary Surfaces in an Introductory Planetary Science Course

    Science.gov (United States)

    Urban, Michael J.

    2013-01-01

    Using an ALTA II reflectance spectrometer, the USGS digital spectral library, graphs of planetary spectra, and a few mineral hand samples, one can teach how light can be used to study planets and moons. The author created the hands-on, inquiry-based activity for an undergraduate planetary science course consisting of freshman to senior level…

  2. Surface enhanced Raman spectroscopy: A review of recent applications in forensic science.

    Science.gov (United States)

    Fikiet, Marisia A; Khandasammy, Shelby R; Mistek, Ewelina; Ahmed, Yasmine; Halámková, Lenka; Bueno, Justin; Lednev, Igor K

    2018-05-15

    Surface enhanced Raman spectroscopy has many advantages over its parent technique of Raman spectroscopy. Some of these advantages such as increased sensitivity and selectivity and therefore the possibility of small sample sizes and detection of small concentrations are invaluable in the field of forensics. A variety of new SERS surfaces and novel approaches are presented here on a wide range of forensically relevant topics. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. 4th-International Symposium on Ultrafast Surface Science - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Hrvoje Petek

    2005-01-26

    The 4-th International Symposium on Ultrafast Surface Dynamics (UDS4) was held at the Telluride Summer Research Center on June 22-27, 2003. The International Organizing Committee consisting of Hrvoje Petek (USA), Xiaoyang Zhu (USA), Pedro Echenique (Spain) and Maki Kawai (Japan) brought together a total of 51 participants 16 of whom were from Europe, 10 from Japan, and 25 from the USA. The focus of the conference was on ultrafast electron or light induced processes at well-defined surfaces. Ultrafast surface dynamics concerns the transfer of charge and energy at solid surfaces on the femtosecond time scale. These processes govern rates of fundamental steps in surface reactions, interfacial electron transfer in molecular electronics, and relaxation in spin transport. Recent developments in femtosecond laser technology make it possible to measure by a variety of nonlinear optical techniques directly in the time domain the microscopic rates underlying these interfacial processes. Parallel progress in scanning probe microscopy makes it possible at a single molecular level to perform the vibrational and electronic spectroscopy measurements, to induce reactions with tunneling electrons, and to observe their outcome. There is no doubt that successful development in the field of ultrafast surface dynamics will contribute to many important disciplines.

  4. Surface science analysis of GaAs photocathodes following sustained electron beam delivery

    Directory of Open Access Journals (Sweden)

    V. Shutthanandan

    2012-06-01

    Full Text Available Degradation of the photocathode materials employed in photoinjectors represents a challenge for sustained operation of nuclear physics accelerators and high power free electron lasers (FEL. Photocathode quantum efficiency degradation is due to residual gases in the electron source vacuum system being ionized and accelerated back to the photocathode. These investigations are a first attempt to characterize the nature of the photocathode degradation, and employ multiple surface and bulk analysis techniques to investigate damage mechanisms including sputtering of the Cs-oxidant surface monolayer, other surface chemistry effects, and ion implantation. Surface and bulk analysis studies were conducted on two GaAs photocathodes, which were removed from the JLab FEL DC photoemission gun after delivering electron beam, and two control samples. The analysis techniques include helium ion microscopy, Rutherford backscattering spectrometry (RBS, atomic force microscopy, and secondary ion mass spectrometry (SIMS. In addition, two high-polarization strained superlattice GaAs photocathode samples, one removed from the continuous electron beam accelerator facility (CEBAF photoinjector and one unused, were also analyzed using transmission electron microscopy (TEM and SIMS. It was found that heat cleaning the FEL GaAs wafer introduces surface roughness, which seems to be reduced by prolonged use. The bulk GaAs samples retained a fairly well organized crystalline structure after delivering beam but show evidence of Cs depletion on the surface. Within the precision of the SIMS and RBS measurements, the data showed no indication of hydrogen implantation or lattice damage from ion back bombardment in the bulk GaAs wafers. In contrast, SIMS and TEM measurements of the strained superlattice photocathode show clear crystal damage in the wafer from ion back bombardment.

  5. Surface science analysis of GaAs photocathodes following sustained electron beam delivery

    Energy Technology Data Exchange (ETDEWEB)

    Carlos Hernandez-Garcia, Fay Hannon, Marcy Stutzman, V. Shutthanandan, Z. Zhu, M. Nandasri, S. V. Kuchibhatla, S. Thevuthasan, W. P. Hess

    2012-06-01

    Degradation of the photocathode materials employed in photoinjectors represents a challenge for sustained operation of nuclear physics accelerators and high power Free Electron Lasers (FEL). Photocathode quantum efficiency (QE) degradation is due to residual gasses in the electron source vacuum system being ionized and accelerated back to the photocathode. These investigations are a first attempt to characterize the nature of the photocathode degradation, and employ multiple surface and bulk analysis techniques to investigate damage mechanisms including sputtering of the Cs-oxidant surface monolayer, other surface chemistry effects, and ion implantation. Surface and bulk analysis studies were conducted on two GaAs photocathodes, which were removed from the JLab FEL DC photoemission gun after delivering electron beam, and two control samples. The analysis techniques include Helium Ion Microscopy (HIM), Rutherford Backscattering Spectrometry (RBS), Atomic Force Microscopy (AFM) and Secondary Ion Mass Spectrometry (SIMS). In addition, two high-polarization strained superlattice GaAs photocathode samples, one removed from the Continuous Electron Beam Accelerator Facility (CEBAF) photoinjector and one unused, were also analyzed using Transmission Electron Microscopy (TEM) and SIMS. It was found that heat cleaning the FEL GaAs wafer introduces surface roughness, which seems to be reduced by prolonged use. The bulk GaAs samples retained a fairly well organized crystalline structure after delivering beam but shows evidence of Cs depletion on the surface. Within the precision of the SIMS and RBS measurements the data showed no indication of hydrogen implantation or lattice damage from ion back bombardment in the bulk GaAs wafers. In contrast, SIMS and TEM measurements of the strained superlattice photocathode show clear crystal damage in the wafer from ion back bombardment.

  6. Lunar and planetary surface conditions advances in space science and technology

    CERN Document Server

    Weil, Nicholas A

    1965-01-01

    Lunar and Planetary Surface Conditions considers the inferential knowledge concerning the surfaces of the Moon and the planetary companions in the Solar System. The information presented in this four-chapter book is based on remote observations and measurements from the vantage point of Earth and on the results obtained from accelerated space program of the United States and U.S.S.R. Chapter 1 presents the prevalent hypotheses on the origin and age of the Solar System, followed by a brief description of the methods and feasibility of information acquisition concerning lunar and planetary data,

  7. Interaction of oxygen and carbon monoxide with Pt(111) at intermediate pressure and temperature : revisiting the fruit fly of surface science

    NARCIS (Netherlands)

    Bashlakov, Dmytro

    2014-01-01

    This thesis uses the surface science approach to address questions regarding the interaction of oxygen with platinum and its subsequent reaction with carbon monoxide. A Pt(111) single crystal surface is used as a model for the catalyst. Chapter 1 provides an overview of the literature on the

  8. Electron paramagnetic resonance and dynamic nuclear polarization of char suspensions: surface science and oximetry

    DEFF Research Database (Denmark)

    Clarkson, R B; Odintsov, B M; Ceroke, P J

    1998-01-01

    ; they can be calibrated and used for oximetry. Biological stability and low toxicity make chars good sensors for in vivo measurements. Scalar and dipolar interactions of water protons at the surfaces of chars may be utilized to produce dynamic nuclear polarization (DNP) of the nuclear spin population...

  9. Evolving research directions in Surface Ocean-Lower Atmosphere (SOLAS) science

    NARCIS (Netherlands)

    Law, Cliff S.; Breviere, Emilie; de Leeuw, Gerrit; Garcon, Veronique; Guieu, Cecile; Kieber, David J.; Kontradowitz, Stefan; Paulmier, Aurelien; Quinn, Patricia K.; Saltzman, Eric S.; Stefels, Jacqueline; von Glasow, Roland

    2013-01-01

    This review focuses on critical issues in ocean-atmosphere exchange that will be addressed by new research strategies developed by the international Surface Ocean-Lower Atmosphere Study (SOLAS) research community. Eastern boundary upwelling systems are important sites for CO2 and trace gas emission

  10. The application of surface science in the solution of aircraft materials problems

    International Nuclear Information System (INIS)

    Arnott, D.R.

    1999-01-01

    Full text: There is now a tendency for both commercial and military aircraft to be maintained and operated for several decades. Indeed some of our front-line defence aircraft have programme withdrawal lives approaching half a century. This places significant demands on the materials used in engines and airframes. The properties and performance of the materials can degrade with time leading to an increase in the importance of repair and maintenance technologies. As most materials problems start at a surface or an interface, it is not surprising that surface sensitive tools are used to resolve many degradation problems. In some cases, the resolution of problems can lead to life-enhancing improvements for the aircraft. This paper will examine some of the practical issues in the use of surface analytical tools for the examination and resolution of practical aircraft problems. Illustrations will be drawn from the application of surface analysis in the areas of corrosion, fracture and adhesive bonding. Copyright (1999) Australian X-ray Analytical Association Inc

  11. Teeth and bones: applications of surface science to dental materials and related biomaterials

    Science.gov (United States)

    Jones, F. H.

    2001-05-01

    Recent years have seen a considerable upsurge in publications concerning the surface structure and chemistry of materials with biological or biomedical applications. Within the body, gas-solid interactions become relatively less significant and solid-liquid or solid-solid interfaces dominate, providing new challenges for the surface scientist. The current paper aims to provide a timely review of the use of surface analysis and modification techniques within the biomaterials field. A broad overview of applications in a number of related areas is given with particular attention focusing on those materials commonly encountered in dentistry and oral or maxillofacial implantology. Several specific issues of current interest are discussed. The interaction between synthetic and natural solids, both in the oral environment and elsewhere in the body is important in terms of adhesion, related stresses and strains and ultimately the longevity of a dental restoration, biomedical implant, or indeed the surrounding tissue. Exposure to body fluids, of course, can also affect stability, leading to the degradation or corrosion of materials within the body. Whilst this could potentially be harmful, e.g., if cytotoxic elements are released, it may alternatively provide a route to the preferential release of beneficial substances. Furthermore, in some cases, the controlled disintegration of a biomaterial is desirable, allowing the removal of an implant, e.g., without the need for further surgery. The presence of cells in the immediate bioenvironment additionally complicates the situation. A considerable amount of current research activity is targeted at the development of coatings or surface treatments to encourage tissue growth. If this is to be achieved by stimulating enhanced cell productivity, determination of the relationship between cell function and surface composition is essential.

  12. Monitoring surface water quality using social media in the context of citizen science

    Science.gov (United States)

    Zheng, Hang; Hong, Yang; Long, Di; Jing, Hua

    2017-02-01

    Surface water quality monitoring (SWQM) provides essential information for water environmental protection. However, SWQM is costly and limited in terms of equipment and sites. The global popularity of social media and intelligent mobile devices with GPS and photography functions allows citizens to monitor surface water quality. This study aims to propose a method for SWQM using social media platforms. Specifically, a WeChat-based application platform is built to collect water quality reports from volunteers, which have been proven valuable for water quality monitoring. The methods for data screening and volunteer recruitment are discussed based on the collected reports. The proposed methods provide a framework for collecting water quality data from citizens and offer a primary foundation for big data analysis in future research.

  13. Evolving research directions in Surface Ocean-Lower Atmosphere (SOLAS) science

    OpenAIRE

    Law, CS; Brévière, E; De Leeuw, G; Garçon, V; Guieu, C; Kieber, DJ; Kontradowitz, S; Paulmier, A; Quinn, PK; Saltzman, ES; Stefels, J; Von Glasow, R

    2013-01-01

    This review focuses on critical issues in ocean-atmosphere exchange that will be addressed by new research strategies developed by the international Surface Ocean-Lower Atmosphere Study (SOLAS) research community. Eastern boundary upwelling systems are important sites for CO 2 and trace gas emission to the atmosphere, and the proposed research will examine how heterotrophic processes in the underlying oxygen-deficient waters interact with the climate system. The second regional research focu...

  14. Radon exhalation of cementitious materials made with coal fly ash: Part 1 - scientific background and testing of the cement and fly ash emanation

    International Nuclear Information System (INIS)

    Kovler, K.; Perevalov, A.; Steiner, V.; Metzger, L.A.

    2005-01-01

    Increased interest in measuring radionuclides and radon concentrations in fly ash, cement and other components of building products is due to the concern of health hazards of naturally occurring radioactive materials (NORM). The current work focuses on studying the influence of fly ash (FA) on radon-exhalation rate (radon flux) from cementitious materials. The tests were carried out on cement paste specimens with different FA contents. The first part of the paper presents the scientific background and describes the experiments, which we designed for testing the radon emanation of the raw materials used in the preparation of the cement-FA pastes. It is found that despite the higher 226 Ra content in FA (more than 3 times, compared with Portland cement) the radon emanation is significantly lower in FA (7.65% for cement vs. 0.52% only for FA)

  15. Microplastic distribution in global marine surface waters: results of an extensive citizen science study

    Science.gov (United States)

    Barrows, A.; Petersen, C.

    2017-12-01

    Plastic is a major pollutant throughout the world. The majority of the 322 million tons produced annually is used for single-use packaging. What makes plastic an attractive packaging material: cheap, light-weight and durable are also the features that help make it a common and persistent pollutant. There is a growing body of research on microplastic, particles less than 5 mm in size. Microfibers are the most common microplastic in the marine environment. Global estimates of marine microplastic surface concentrations are based on relatively small sample sizes when compared to the vast geographic scale of the ocean. Microplastic residence time and movement along the coast and sea surface outside of the gyres is still not well researched. This five-year project utilized global citizen scientists to collect 1,628 1-liter surface grab samples in every major ocean. The Artic and Southern oceans contained highest average of particles per liter of surface water. Open ocean samples (further than 12 nm from land, n = 686) contained a higher particle average (17 pieces L-1) than coastal samples (n = 723) 6 pieces L-1. Particles were predominantly 100 µm- 1.5 mm in length (77%), smaller than what has been captured in the majority of surface studies. Utilization of citizen scientists to collect data both in fairly accessible regions of the world as well as from areas hard to reach and therefore under sampled, provides us with a wider perspective of global microplastics occurrence. Our findings confirm global microplastic accumulation zone model predictions. The open ocean and poles have sequestered and trapped plastic for over half a century, and show that not only plastics, but anthropogenic fibers are polluting the environment. Continuing to fill knowledge gaps on microplastic shape, size and color in remote ocean areas will drive more accurate oceanographic models of plastic accumulation zones. Incorporation of smaller-sized particles in these models, which has previously

  16. Electronic materials high-T(sub c) superconductivity polymers and composites structural materials surface science and catalysts industry participation

    Science.gov (United States)

    1988-01-01

    The fifth year of the Center for Advanced Materials was marked primarily by the significant scientific accomplishments of the research programs. The Electronics Materials program continued its work on the growth and characterization of gallium arsenide crystals, and the development of theories to understand the nature and distribution of defects in the crystals. The High Tc Superconductivity Program continued to make significant contributions to the field in theoretical and experimental work on both bulk materials and thin films and devices. The Ceramic Processing group developed a new technique for cladding YBCO superconductors for high current applications in work with the Electric Power Research Institute. The Polymers and Composites program published a number of important studies involving atomistic simulations of polymer surfaces with excellent correlations to experimental results. The new Enzymatic Synthesis of Materials project produced its first fluorinated polymers and successfully began engineering enzymes designed for materials synthesis. The structural Materials Program continued work on novel alloys, development of processing methods for advanced ceramics, and characterization of mechanical properties of these materials, including the newly documented characterization of cyclic fatigue crack propagation behavior in toughened ceramics. Finally, the Surface Science and Catalysis program made significant contributions to the understanding of microporous catalysts and the nature of surface structures and interface compounds.

  17. Study of variations of radon emanations from soil in Morocco using solid state nuclear track detectors. Correlations with atmospheric parameters and seismic activities

    International Nuclear Information System (INIS)

    Boukhal, H.

    1993-01-01

    This study investigates the quantity variations of radon emanating from soil in accordance with time. It aims to verify the possibility of the radon sign use in earthquake prediction. Regular measures of radon concentration in soil have been carried out over the two years 1991 and 1992 in five towns of Morocco: Rabat, Tetouan, Ifrane and Khouribga, and in geophysic observatory of Ibn Rochd (Berchid region). The measuring method is based on the solid state nuclear track detectors technique. The obtained results have shown an influence of the atmospheric effects on the radon emanation. The experiment proved that, on one hand, the variations of the aforesaid influence are correlated to variations of the pluviometry and the atmospheric temperature and, on the other hand, there is no notable effect of atmospheric pressure or atmospheric humidity. The good correlations between the different seismic activities and the variations of radon emanation rate in the five measurement stations, have shown the interest of radon use in the earthquake prediction field. 81 refs., 100 figs., 17 tabs.(F. M.)

  18. Surface Science in an MOCVD Environment: Arsenic on Vicinal Ge(100)

    International Nuclear Information System (INIS)

    Olson, J.M.; McMahon, W.E.

    1998-01-01

    Scanning tunneling microscope (STM) images of arsine-exposed vicinal Ge(100) surfaces show that most As/Ge steps are reconstructed, and that a variety of different step structures exist. The entire family of reconstructed As/Ge steps can be divided into two types, which we have chosen to call ''single-row'' steps and ''double-row'' steps. In this paper we propose a model for a double-row step created by annealing a vicinal Ge(100) substrate under an arsine flux in a metal-organic chemical vapor deposition (MOCVD) chamber

  19. Electron collisions with atoms, ions, molecules, and surfaces: Fundamental science empowering advances in technology

    Science.gov (United States)

    Bartschat, Klaus; Kushner, Mark J.

    2016-06-01

    Electron collisions with atoms, ions, molecules, and surfaces are critically important to the understanding and modeling of low-temperature plasmas (LTPs), and so in the development of technologies based on LTPs. Recent progress in obtaining experimental benchmark data and the development of highly sophisticated computational methods is highlighted. With the cesium-based diode-pumped alkali laser and remote plasma etching of Si3N4 as examples, we demonstrate how accurate and comprehensive datasets for electron collisions enable complex modeling of plasma-using technologies that empower our high-technology-based society.

  20. Raman Under Water - Nonlinear and Nearfield Approaches for Electrochemical Surface Science.

    Science.gov (United States)

    Martín Sabanés, Natalia; Domke, Katrin F

    2017-08-01

    Electrochemistry is re-gaining attention among scientists because the complex interplay between electronic and chemical interfacial processes lies at the bottom of a broad range of important research disciplines like alternative energy conversion or green catalysis and synthesis. While rapid progress has been made in recent years regarding novel technological applications, the community increasingly recognizes that the understanding of the molecular processes that govern macroscopic device properties is still rather limited - which hinders a systematic and more complete exploration of novel material and functionality space. Here, we discuss advanced Raman spectroscopies as valuable analysis tools for electrochemists. The chemical nature of a material and its interaction with the environment is contained in the label-free vibrational fingerprint over a broad energy range so that organic species, solid-state materials, and hybrids thereof can be investigated alike. For surface studies, the inherently small Raman scattering cross sections can be overcome with advanced nonlinear or nearfield-based approaches that provide signal enhancements between three and seven orders of magnitude, sufficient to detect few scatterers in nano-confined spaces or adsorbate (sub)monolayers. Our article highlights how advanced Raman techniques with extreme chemical, spatial and temporal resolution constitute valuable alternative surface analysis tools and provide otherwise inaccessible information about complex interfacial (electro)chemical processes.

  1. Investigation of anti-Relaxation coatings for alkali-metal vapor cells using surface science techniques

    Energy Technology Data Exchange (ETDEWEB)

    Seltzer, S. J.; Michalak, D. J.; Donaldson, M. H.; Balabas, M. V.; Barber, S. K.; Bernasek, S. L.; Bouchiat, M.-A.; Hexemer, A.; Hibberd, A. M.; Jackson Kimball, D. F.; Jaye, C.; Karaulanov, T.; Narducci, F. A.; Rangwala, S. A.; Robinson, H. G.; Shmakov, A. K.; Voronov, D. L.; Yashchuk, V. V.; Pines, A.; Budker, D.

    2010-10-11

    Many technologies based on cells containing alkali-metal atomic vapor benefit from the use of antirelaxation surface coatings in order to preserve atomic spin polarization. In particular, paraffin has been used for this purpose for several decades and has been demonstrated to allow an atom to experience up to 10?000 collisions with the walls of its container without depolarizing, but the details of its operation remain poorly understood. We apply modern surface and bulk techniques to the study of paraffin coatings in order to characterize the properties that enable the effective preservation of alkali spin polarization. These methods include Fourier transform infrared spectroscopy, differential scanning calorimetry, atomic force microscopy, near-edge x-ray absorption fine structure spectroscopy, and x-ray photoelectron spectroscopy. We also compare the light-induced atomic desorption yields of several different paraffin materials. Experimental results include the determination that crystallinity of the coating material is unnecessary, and the detection of C=C double bonds present within a particular class of effective paraffin coatings. Further study should lead to the development of more robust paraffin antirelaxation coatings, as well as the design and synthesis of new classes of coating materials.

  2. Electron/positron measurements obtained with the Mars Science Laboratory Radiation Assessment Detector on the surface of Mars

    Energy Technology Data Exchange (ETDEWEB)

    Koehler, J.; Wimmer-Schweingruber, R.F.; Appel, J. [Kiel Univ. (Germany). Inst. of Experimental and Applied Physics; and others

    2016-04-01

    The Radiation Assessment Detector (RAD), on board the Mars Science Laboratory (MSL) rover Curiosity, measures the energetic charged and neutral particles and the radiation dose rate on the surface of Mars. Although charged and neutral particle spectra have been investigated in detail, the electron and positron spectra have not been investigated yet. The reason for that is that they are difficult to separate from each other and because of the technical challenges involved in extracting energy spectra from the raw data. We use GEANT4 to model the behavior of the RAD instrument for electron/positron measurements.We compare Planetocosmics predictions for different atmospheric pressures and different modulation parameters Φ with the obtained RAD electron/positron measurements.We find that the RAD electron/positron measurements agree well with the spectra predicted by Planetocosmics. Both RAD measurements and Planetocosmics simulation show a dependence of the electron/positron fluxes on both atmospheric pressure and solar modulation potential.

  3. Electron paramagnetic resonance and dynamic nuclear polarization of char suspensions: surface science and oximetry

    International Nuclear Information System (INIS)

    Clarkson, R.B.; Odintsov, B.M.; Ceroke, P.J.; Ardenkjaer-Larsen, J.H.; Fruianu, M.; Belford, R.L.

    1998-01-01

    Carbon chars have been synthesized in our laboratory from a variety of starting materials, by means of a highly controlled pyrolysis technique. These chars exhibit electron paramagnetic resonance (EPR) line shapes which change with the local oxygen concentration in a reproducible and stable fashion; they can be calibrated and used for oximetry. Biological stability and low toxicity make chars good sensors for in vivo measurements. Scalar and dipolar interactions of water protons at the surfaces of chars may be utilized to produce dynamic nuclear polarization (DNP) of the 1 H nuclear spin population in conjunction with electron Zeeman pumping. Low-frequency EPR, DNP and DNP-enhanced MRI all show promise as oximetry methods when used with carbon chars. (author)

  4. Biomimetics Bioinspired Hierarchical-Structured Surfaces for Green Science and Technology

    CERN Document Server

    Bhushan, Bharat

    2012-01-01

    This book presents an overview of the general field of biomimetics - lessons from nature. It presents various examples of biomimetics, including roughness-induced superomniphobic surfaces which provide functionality of commercial interest. The major focus in the book is on lotus effect, rose petal effect, shark skin effect, and gecko adhesion.  For each example, the book first presents characterization of an object to understand how a natural object provides functionality, followed by modeling and then fabrication of structures in the lab using nature’s route to verify one’s understanding of nature and provide guidance for development of optimum structures. Once it is understood how nature does it, examples of fabrication of optimum structures using smart materials and fabrication techniques, are presented. Examples of nature inspired objects are also presented throughout.

  5. NASA's MODIS/VIIRS Land Surface Temperature and Emissivity Products: Asssessment of Accuracy, Continuity and Science Uses

    Science.gov (United States)

    Hulley, G. C.; Malakar, N.; Islam, T.

    2017-12-01

    Land Surface Temperature and Emissivity (LST&E) are an important Earth System Data Record (ESDR) and Environmental Climate Variable (ECV) defined by NASA and GCOS respectively. LST&E data are key variables used in land cover/land use change studies, in surface energy balance and atmospheric water vapor retrieval models and retrievals, and in climate research. LST&E products are currently produced on a routine basis using data from the MODIS instruments on the NASA EOS platforms and by the VIIRS instrument on the Suomi-NPP platform that serves as a bridge between NASA EOS and the next-generation JPSS platforms. Two new NASA LST&E products for MODIS (MxD21) and VIIRS (VNP21) are being produced during 2017 using a new approach that addresses discrepancies in accuracy and consistency between the current suite of split-window based LST products. The new approach uses a Temperature Emissivity Separation (TES) algorithm, originally developed for the ASTER instrument, to physically retrieve both LST and spectral emissivity consistently for both sensors with high accuracy and well defined uncertainties. This study provides a rigorous assessment of accuracy of the MxD21/VNP21 products using temperature- and radiance-based validation strategies and demonstrates continuity between the products using collocated matchups over CONUS. We will further demonstrate potential science use of the new products with studies related to heat waves, monitoring snow melt dynamics, and land cover/land use change.

  6. Density functionals for surface science: Exchange-correlation model development with Bayesian error estimation

    DEFF Research Database (Denmark)

    Wellendorff, Jess; Lundgård, Keld Troen; Møgelhøj, Andreas

    2012-01-01

    A methodology for semiempirical density functional optimization, using regularization and cross-validation methods from machine learning, is developed. We demonstrate that such methods enable well-behaved exchange-correlation approximations in very flexible model spaces, thus avoiding the overfit......A methodology for semiempirical density functional optimization, using regularization and cross-validation methods from machine learning, is developed. We demonstrate that such methods enable well-behaved exchange-correlation approximations in very flexible model spaces, thus avoiding...... the energetics of intramolecular and intermolecular, bulk solid, and surface chemical bonding, and the developed optimization method explicitly handles making the compromise based on the directions in model space favored by different materials properties. The approach is applied to designing the Bayesian error...... estimation functional with van der Waals correlation (BEEF-vdW), a semilocal approximation with an additional nonlocal correlation term. Furthermore, an ensemble of functionals around BEEF-vdW comes out naturally, offering an estimate of the computational error. An extensive assessment on a range of data...

  7. Application and outlook of the pulsed neutron beam at J-PARC (3). Introduction of high-pressure science and surface/interface analysis at J-PARC

    International Nuclear Information System (INIS)

    Hattori, Takanori; Akutsu, Kazuhiro; Suzuki, Junichi

    2015-01-01

    At the MLF (Materials and Life Science Experimental Facility) of J-PARC (Japan Proton Accelerator Research Complex), eighteen neutron beam lines equipped with experimental apparatus are in operation and deliver the world highest intensity pulsed neutron beam for fundamental sciences such as solid state physics, materials science, life science, elementary particle physics, nuclear science, and for industrial applications. We introduce studies using an ultra-high pressure neutron diffractometer 'PLANET' for the structure analysis under high-pressure surroundings and a polarized neutron reflectometer 'SHARAKU' for the analysis of surface/interface structure with scales ranging from nano- to submicron-meter. We also introduce briefly all the apparatus for neuron experiments at the MLF. (J.P.N.)

  8. A low technology emanator treated with the volatile pyrethroid transfluthrin confers long term protection against outdoor biting vectors of lymphatic filariasis, arboviruses and malaria.

    Science.gov (United States)

    Ogoma, Sheila B; Mmando, Arnold S; Swai, Johnson K; Horstmann, Sebastian; Malone, David; Killeen, Gerry F

    2017-04-01

    The vapor phase of the volatile pyrethroid transfluthrin incapacitates mosquitoes and prevents them from feeding. Although existing emanator products for delivering volatile pyrethroids protect against outdoor mosquito bites, they are too short-lived to be practical or affordable for routine use in low-income settings. New transfluthrin emanators, comprised simply of treated hessian fabric strips, have recently proven highly protective against outdoor-biting vectors of lymphatic filariasis, arboviruses and malaria, but their full protective lifespan, minimum dose requirements, and range of protection have not previously been assessed. The effects of transfluthrin-treated hessian strips upon mosquito biting exposure of users and nearby non-users, as well as dependence of protection upon treatment dose, were measured outdoors in rural Tanzania using human landing catches (HLC). Strips treated with 10ml of transfluthrin prevented at least three quarters (p bites by Anopheles arabiensis, Culex spp. and Mansonia spp. mosquitoes, and >90% protection against bites on warmer nights with higher evaporation rates, for at least one year. Strips treated with this high dose also reduced biting exposure of non-users at a distance of up to 5m from the strips for An. arabiensis (p < 0.001) and up to 2m for Mansonia spp. (p = 0.008), but provided no protection to non-users against Culex spp. No evidence of increased risk for non-users, caused by diversion of mosquitoes to unprotected individuals, was found at any distance within an 80m radius. A dose of only 1ml provided equivalent protection to the 10ml dose against An. arabiensis, Culex spp. and Mansonia spp. mosquitoes over 6 months (p < 0.001). Transfluthrin-treated hessian emanators provide safe, affordable, long-term protection against several different pathogen-transmitting mosquito taxa that attack humans outdoors, where they are usually active and cannot be protected by bed nets or residual sprays with conventional, solid

  9. Response Surface Methodology Using a Fullest Balanced Model: A Re-Analysis of a Dataset in theKorean Journal for Food Science of Animal Resources.

    Science.gov (United States)

    Rheem, Sungsue; Rheem, Insoo; Oh, Sejong

    2017-01-01

    Response surface methodology (RSM) is a useful set of statistical techniques for modeling and optimizing responses in research studies of food science. In the analysis of response surface data, a second-order polynomial regression model is usually used. However, sometimes we encounter situations where the fit of the second-order model is poor. If the model fitted to the data has a poor fit including a lack of fit, the modeling and optimization results might not be accurate. In such a case, using a fullest balanced model, which has no lack of fit, can fix such problem, enhancing the accuracy of the response surface modeling and optimization. This article presents how to develop and use such a model for the better modeling and optimizing of the response through an illustrative re-analysis of a dataset in Park et al. (2014) published in the Korean Journal for Food Science of Animal Resources .

  10. Surface Ozone Measured at GLOBE Schools in the Czech Republic: A Demonstration of the Importance of Student Contribution to the Larger Science Picture

    Science.gov (United States)

    Pippin, Margaret R.; Creilson, John K.; Henderson, Bryana L.; Ladd, Irene H.; Fishman, Jack; Votapkova, Dana; Krpcova, Ilona

    2008-01-01

    GLOBE (Global Learning and Observations to Benefit the Environment) is a worldwide hands-on, primary and secondary school-based education and science program, developed to give students a chance to perform real science by making measurements, analyzing data, and participating in research in collaboration with scientists. As part of the GLOBE Surface Ozone Protocol and with the assistance of the TEREZA Association in the Czech Republic, schools in the Czech Republic have been making and reporting daily measurements of surface ozone and surface meteorological data since 2001. Using a hand-held ozone monitor developed for GLOBE, students at several Czech schools have generated multiyear data records of surface ozone from 2001 to 2005. Analysis of the data shows surface ozone levels were anomalously high during the summer of 2003 relative to other summers. These findings are consistent with measurements by the European Environment Agency that highlights the summer of 2003 as having exceptionally long-lasting and spatially extensive episodes of high surface ozone, especially during the first half of August. Further analysis of the summer s prevailing meteorology shows not only that it was one of the hottest on record, a finding also seen in the student data, but the conditions for production of ozone were ideal. Findings such as these increase student, teacher, and scientist confidence in the utility of the GLOBE data for engaging budding scientists in the collection, analysis, and eventual interpretation of the data for inquiry-based education.

  11. Combining low-energy electron microscopy and scanning probe microscopy techniques for surface science: development of a novel sample-holder.

    Science.gov (United States)

    Cheynis, F; Leroy, F; Ranguis, A; Detailleur, B; Bindzi, P; Veit, C; Bon, W; Müller, P

    2014-04-01

    We introduce an experimental facility dedicated to surface science that combines Low-Energy Electron Microscopy/Photo-Electron Emission Microscopy (LEEM/PEEM) and variable-temperature Scanning Probe Microscopy techniques. A technical challenge has been to design a sample-holder that allows to exploit the complementary specifications of both microscopes and to preserve their optimal functionality. Experimental demonstration is reported by characterizing under ultrahigh vacuum with both techniques: Au(111) surface reconstruction and a two-layer thick graphene on 6H-SiC(0001). A set of macros to analyze LEEM/PEEM data extends the capabilities of the setup.

  12. Rare-gas yields in 238U and 232Th fission by 14MeV neutrons, measured by an emanating method

    International Nuclear Information System (INIS)

    Feu Alvim, C.A.; Bocquet, J.P.; Brissot, R.; Crancon, J.; Moussa, A.

    1977-01-01

    A direct method, using emanation of rare gases by uranyle stearate and thorium stearate, has been applied to the measurement of cumulative fractional yields of certain isotopes of krypton and xenon, in the fissions of 238 U and 232 Th by 14MeV-neutrons. The independent yields of the same isotopes were measured previously by means of isotopic on-line separation. From these results, the widths of the mass and charge distributions, the relative chain yields, the fractional cumulative yields of certain bromine and iodine isotopes, the values of Zsub(p) the most probable charge, in the isobaric chains 87-93 and 137-142, and the elemental yields of krypton and xenon were calculated [fr

  13. Proceedings of the Edgewood Chemical Biological Center In-House Laboratory Independent Research and Surface Science Initiative Programs FY12

    Science.gov (United States)

    2012-01-01

    APPROVED FOR PUBLIC RELEASE "Designing Strongly Repellant Surfaces via Molecular Dynamics Simulations" (PI: Cabalo ). This study used atomistic simulations...from Metallic Nanoparticles and Nanostructured Surfaces Jason Guicheteau, Ashish Tripathi, Erik Emmons, Jerry Cabalo , Craig Knox, Brandon Scott...Surfaces via Molecular Dynamics Simulations Craig Knox, Jerry Cabalo , Stephanie Ihejirika, Gary Kilper 116 Vll APPROVED FOR PUBLIC RELEASE Vlll

  14. Associateship | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Specialization: AIMD Simulation, X-ray Science, Ultrafast Science, Surface Science, Molecular Beam Experiments Address: IPC Department, Indian Institute of Science, .... Specialization: Game Theory & Optimisation, Stochastic Control, Information Theory Address: Systems & Control Engineering, Indian Institute of ...

  15. Raiders of the Lost Art: A review of published evaluations of inpatient mental health care experiences emanating from the United Kingdom, Portugal, Canada, Switzerland, Germany and Australia.

    Science.gov (United States)

    Cutcliffe, John R; Santos, Jose Carlos; Kozel, Bernd; Taylor, Petrea; Lees, David

    2015-10-01

    Forming interpersonal therapeutic relationships with mental health Service Users remains a key aspect of the practice of Psychiatric/Mental Health nurses. Given the omnipresence of the concept within the relevant literature the reader could be forgiven for asking: why would Psychiatric/Mental Health nurses opine about something so basic, so ubiquitous and so central to the theory and practice of our discipline? While the authors could locate no substantive argument that refutes the role or value of such relationships, a sizable, growing and reasonably consistent body of work has emerged, which appears to indicate that this centrality and value is not necessarily reflected in many clinical practice settings. Accordingly, we draw on the published evaluations of mental health care emanating from the United Kingdom, Portugal, Canada, Switzerland, Germany and Australia, compare these findings and highlight similarities or/and congruence and discuss a range of issues arising out of the findings. Alas, the findings seem to depict a mental health care inpatient experience that is often devoid of warm therapeutic relationships, respectful interactions, information or choice about treatment and any kind of formal/informal 'talk therapy'. Instead such care experiences are personified by: coercion, disinterest, inhumane practices, custodial and controlling practitioners and a gross over use of pharmacological 'treatments'. © 2015 Australian College of Mental Health Nurses Inc.

  16. Tritium Plasma Experiment Upgrade and Improvement of Surface Diagnostic Capabilities at STAR Facility for Enhancing Tritium and Nuclear PMI Sciences

    Energy Technology Data Exchange (ETDEWEB)

    Shimada, M.; Taylor, C. N.; Pawelko, R. J.; Cadwallader, L. C.; Merrill, B. J.

    2016-04-01

    The Tritium Plasma Experiment (TPE) is a unique high-flux linear plasma device that can handle beryllium, tritium, and neutron-irradiated plasma facing materials, and is the only existing device dedicated to directly study tritium retention and permeation in neutron-irradiated materials with tritium [M. Shimada et.al., Rev. Sci. Instru. 82 (2011) 083503 and and M. Shimada, et.al., Nucl. Fusion 55 (2015) 013008]. The plasma-material-interaction (PMI) determines a boundary condition for diffusing tritium into bulk PFCs, and the tritium PMI is crucial for enhancing fundamental sciences that dictate tritium fuel cycles and safety and are high importance to an FNSF and DEMO. Recently the TPE has undergone major upgrades in its electrical and control systems. New DC power supplies and a new control center enable remote plasma operations from outside of the contamination area for tritium, minimizing the possible exposure risk with tritium and beryllium. We discuss the electrical upgrade, enhanced operational safety, improved plasma performance, and development of optical spectrometer system. This upgrade not only improves operational safety of the worker, but also enhances plasma performance to better simulate extreme plasma-material conditions expected in ITER, Fusion Nuclear Science Facility (FNSF), and Demonstration reactor (DEMO). This work was prepared for the U.S. Department of Energy, Office of Fusion Energy Sciences, under the DOE Idaho Field Office contract number DE-AC07-05ID14517.

  17. Unraveling the Role of Transport, Electrocatalysis, and Surface Science in the Solid Oxide Fuel Cell Cathode Oxygen Reduction Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Gopalan, Srikanth [Boston Univ., MA (United States)

    2017-04-06

    This final report for project FE0009656 covers the period from 10/01/2012 to 09/30/2015 and covers research accomplishments on the effects of carbon dioxide on the surface composition and structure of cathode materials for solid oxide fuel cells (SOFCs), specifically La1-xSrxFeyCo1- yO3-δ (LSCF). Epitaxially deposited thin films of LSCF on various single-crystal substrates have revealed the selective segregation of strontium to the surface thereby resulting in a surface enrichment of strontium. The near surface compositional profile in the films have been measured using total x-ray fluorescence (TXRF), and show that the kinetics of strontium segregation are higher at higher partial pressures of carbon dioxide. Once the strontium segregates to the surface, it leads to the formation of precipitates of SrO which convert to SrCO3 in the presence of even modest concentrations of carbon dioxide in the atmosphere. This has important implications for the performance of SOFCs which is discussed in this report. These experimental observations have also been verified by Density Functional Theory calculations (DFT) which predict the conditions under which SrO and SrCO3 can occur in LSCF. Furthermore, a few cathode compositions which have received attention in the literature as alternatives to LSCF cathodes have been studied in this work and shown to be thermodynamically unstable under the operating conditions of the SOFCs.

  18. Strategy for Ranking the Science Value of the Surface of Asteroid 101955 Bennu for Sample Site Selection for Osiris-REx

    Science.gov (United States)

    Nakamura-Messenger, K.; Connolly, H. C., Jr.; Lauretta, D. S.

    2014-01-01

    OSRIS-REx is NASA's New Frontiers 3 sample return mission that will return at least 60 g of pristine surface material from near-Earth asteroid 101955 Bennu in September 2023. The scientific value of the sample increases enormously with the amount of knowledge captured about the geological context from which the sample is collected. The OSIRIS-REx spacecraft is highly maneuverable and capable of investigating the surface of Bennu at scales down to the sub-cm. The OSIRIS-REx instruments will characterize the overall surface geology including spectral properties, microtexture, and geochemistry of the regolith at the sampling site in exquisite detail for up to 505 days after encountering Bennu in August 2018. The mission requires at the very minimum one acceptable location on the asteroid where a touch-and-go (TAG) sample collection maneuver can be successfully per-formed. Sample site selection requires that the follow-ing maps be produced: Safety, Deliverability, Sampleability, and finally Science Value. If areas on the surface are designated as safe, navigation can fly to them, and they have ingestible regolith, then the scientific value of one site over another will guide site selection.

  19. Improved Methodology for Surface and Atmospheric Soundings, Error Estimates, and Quality Control Procedures: the AIRS Science Team Version-6 Retrieval Algorithm

    Science.gov (United States)

    Susskind, Joel; Blaisdell, John; Iredell, Lena

    2014-01-01

    The AIRS Science Team Version-6 AIRS/AMSU retrieval algorithm is now operational at the Goddard DISC. AIRS Version-6 level-2 products are generated near real-time at the Goddard DISC and all level-2 and level-3 products are available starting from September 2002. This paper describes some of the significant improvements in retrieval methodology contained in the Version-6 retrieval algorithm compared to that previously used in Version-5. In particular, the AIRS Science Team made major improvements with regard to the algorithms used to 1) derive surface skin temperature and surface spectral emissivity; 2) generate the initial state used to start the cloud clearing and retrieval procedures; and 3) derive error estimates and use them for Quality Control. Significant improvements have also been made in the generation of cloud parameters. In addition to the basic AIRS/AMSU mode, Version-6 also operates in an AIRS Only (AO) mode which produces results almost as good as those of the full AIRS/AMSU mode. This paper also demonstrates the improvements of some AIRS Version-6 and Version-6 AO products compared to those obtained using Version-5.

  20. Factors affecting the long-term response of surface waters to acidic deposition: state-of-the-science

    Energy Technology Data Exchange (ETDEWEB)

    Turner, R.S.; Johnson, D.W.; Elwood, J.N.; Van Winkle, W.; Clapp, R.B.; Jones, M.L.; Marmarek, D.R.; Thornton, K.W.; Gherinig, S.A.; Schnoor, J.L.

    1986-01-01

    Recent intensive study of the causes of surface water acidification has led to numerous hypothesized controlling mechanisms. Among these are the salt-effect reduction of alkalinity, the base cation buffering and sulfate adsorption capacities of soils, availability of weatherable minerals (weathering rates), depth of till, micropore flow, and type of forest cover. Correlative and predictive models have been developed to show the relationships (if any) between hypothesized controlling mechanisms and surface water acidity, and to suggest under what conditions additional surface water might become acid. This document (Part A) is a review of our current knowledge of factors and processes controlling soil and surface water acidification, as well as an assessment of the adequacy of that knowledge for making predictions of future acidification. Section 2 is a data extensive, conceptual overview of how watersheds function. Section 3 is a closer look at the theory and evidence for the key hypotheses. Section 4 is a review of existing methods of assessing system response to acidic deposition.

  1. UO2 Fuel pellet impurities, pellet surface roughness and n(18O)/n(16O) ratios, applied to nuclear forensic science

    International Nuclear Information System (INIS)

    Pajo, L.

    2001-01-01

    In the last decade, law enforcement has faced the problem of illicit trafficking of nuclear materials. Nuclear forensic science is a new branch of science that enables the identification of seized nuclear material. The identification is not based on a fixed scheme, but further identification parameters are decided based on previous identification results. The analysis is carried out by using traditional analysis methods and applying modern measurement technology. The parameters are generally not unambiguous and not self-explanatory. In order to have a full picture about the origin of seized samples, several identification parameters should be used together and the measured data should be compared to corresponding data from known sources. A nuclear material database containing data from several fabrication plants is installed for the purpose. In this thesis the use of UO 2 fabrication plant specific parameters, fuel impurities, fuel pellet surface roughness and oxygen isotopic ratio in UO 2 were investigated for identification purposes in nuclear forensic science. The potential use of these parameters as 'fingerprints' is discussed for identification purposes of seized nuclear materials. Impurities of the fuel material vary slightly according to the fabrication method employed and a plant environment. Here the impurities of the seized UO 2 were used in order to have some clues about the origin of the fuel material by comparing a measured data to nuclear database information. More certainty in the identification was gained by surface roughness of the UO 2 fuel pellets, measured by mechanical surface profilometry. Categories in surface roughness between a different fuel element type and a producer were observed. For the time oxygen isotopic ratios were determined by Thermal Ionisation Mass Speckometry (TIMS). Thus a TIMS measurement method, using U 16 O + and U 18 0 + ions, was developed and optimised to achieve precise oxygen isotope ratio measurements for the

  2. Development of a management protocol for the reduction of fuel consumption and decreasing of the emanations of CO2 as contaminant of environment in air service companies

    International Nuclear Information System (INIS)

    Montoya Maroto, Manuel

    2012-01-01

    A management protocol is developed for air services companies to improve the eco-efficiency of its processes. The application of operational procedures have allowed the reduction of fuel consumption and decreased the emanations of CO 2 into the environment. The methodology of the research has consisted in quantitative and qualitative analysis of the variables and processes that have influenced significantly in the operation of airline fleet. An integral analysis is realized of the procedures of management and use of resources in the cockpits of the aircraft (Cockpit Resource Management) and navigation based in performance (NBP). The results of analysis are used to elaborate a protocol to minimize the fuel consumption and energy through the application of practices and operational procedures more efficient and safe. The environmental burdens associated with the services that are provided in the airline industry are minimized. The application of methods of improvement and procedures that are updated continuously have achieved the sustainability of the protocol. The operational procedures are applied to decrease the fuel consumption. Sensitization programs are developed for the utilization of more efficient operational practices and friendly with the environment. An incentive program is implemented to optimize the fuel consumption safely by pilots. A new procedure of flight scheduling is modified based on performance of the pilots and fleet degradation factors, assigning the pilots who have had higher consumption to airplanes with lower degradation, and the pilots who have had lower consumption, to airplanes with higher degradation. A self-liquidating incentive plan is developed based on the savings achieved in the operation in high-performance, could reinforce the change of attitude necessary for the group of pilots can support the implementation of the protocol [es

  3. The shortcomings of semi-local and hybrid functionals: what we can learn from surface science studies

    International Nuclear Information System (INIS)

    Stroppa, A; Kresse, G

    2008-01-01

    A study of the adsorption of CO on late 4d and 5d transition metal (111) surfaces (Ru, Rh, Pd, Ag, Os, Ir and Pt) considering atop and hollow site adsorption is presented. The applied functionals include the gradient-corrected Perdew-Burke-Ernzerhof (PBE) and Becke-Lee-Yang-Parr (BLYP) functionals, and the corresponding hybrid Hartree-Fock density functionals HSE and B3LYP. We find that PBE-based hybrid functionals (specifically HSE) yield, with the exception of Pt, the correct site order on all considered metals, but they also considerably overestimate the adsorption energies compared to experiment. On the other hand, the semi-local BLYP functional and the corresponding hybrid functional B3LYP yield very satisfactory adsorption energies and the correct adsorption site for all surfaces. We are thus faced with a Procrustean problem: the B3LYP and BLYP functionals seem to be the overall best choice for describing adsorption on metal surfaces, but they simultaneously fail to account well for the properties of the metal, vastly overestimating the equilibrium volume and underestimating the atomization energies. Setting out from these observations, general conclusions are drawn on the relative merits and drawbacks of various semi-local and hybrid functionals. The discussion includes a revised version of the PBE functional specifically optimized for bulk properties and surface energies (PBEsol), a revised version of the PBE functional specifically optimized to predict accurate adsorption energies (rPBE), as well as the aforementioned BLYP functional. We conclude that no semi-local functional is capable of describing all aspects properly, and including non-local exchange also only improves some but worsens other properties

  4. Experimental Investigation of Space Radiation Processing in Lunar Soil Ilmenite: Combining Perspectives from Surface Science and Transmission Electron Microscopy

    Science.gov (United States)

    Christoffersen, R.; Keller, L. P.; Rahman, Z.; Baragiola, R.

    2010-01-01

    Energetic ions mostly from the solar wind play a major role in lunar space weathering because they contribute structural and chemical changes to the space-exposed surfaces of lunar regolith grains. In mature mare soils, ilmenite (FeTiO3) grains in the finest size fraction have been shown in transmission electron microscope (TEM) studies to exhibit key differences in their response to space radiation processing relative to silicates [1,2,3]. In ilmenite, solar ion radiation alters host grain outer margins to produce 10-100 nm thick layers that are microstructurally complex, but dominantly crystalline compared to the amorphous radiation-processed rims on silicates [1,2,3]. Spatially well-resolved analytical TEM measurements also show nm-scale compositional and chemical state changes in these layers [1,3]. These include shifts in Fe/Ti ratio from strong surface Fe-enrichment (Fe/Ti >> 1), to Fe depletion (Fe/Ti < 1) at 40-50 nm below the grain surface [1,3]. These compositional changes are not observed in the radiation-processed rims on silicates [4]. Several mechanism(s) to explain the overall relations in the ilmenite grain rims by radiation processing and/or additional space weathering processes were proposed by [1], and remain under current consideration [3]. A key issue has concerned the ability of ion radiation processing alone to produce some of the deeper- penetrating compositional changes. In order to provide some experimental constraints on these questions, we have performed a combined X-ray photoelectron spectroscopy (XPS) and field-emission scanning transmission electron (FE-STEM) study of experimentally ion-irradiated ilmenite. A key feature of this work is the combination of analytical techniques sensitive to changes in the irradiated samples at depth scales going from the immediate surface (approx.5 nm; XPS), to deeper in the grain interior (5-100 nm; FE-STEM).

  5. Micrometer-sized Water Ice Particles for Planetary Science Experiments: Influence of Surface Structure on Collisional Properties

    Energy Technology Data Exchange (ETDEWEB)

    Gärtner, S.; Fraser, H. J. [School of Physical Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Gundlach, B.; Ratte, J.; Blum, J. [Institut für Geophysik und extraterrestrische Physik, TU Braunschweig, Mendelssohnstr. 3, D-38106 Braunschweig (Germany); Headen, T. F.; Youngs, T. G. A.; Bowron, D. T. [ISIS Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX (United Kingdom); Oesert, J.; Gorb, S. N., E-mail: sabrina.gaertner@stfc.ac.uk, E-mail: helen.fraser@open.ac.uk [Zoologisches Institut, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 1-9, D-24118 Kiel (Germany)

    2017-10-20

    Models and observations suggest that ice-particle aggregation at and beyond the snowline dominates the earliest stages of planet formation, which therefore is subject to many laboratory studies. However, the pressure–temperature gradients in protoplanetary disks mean that the ices are constantly processed, undergoing phase changes between different solid phases and the gas phase. Open questions remain as to whether the properties of the icy particles themselves dictate collision outcomes and therefore how effectively collision experiments reproduce conditions in protoplanetary environments. Previous experiments often yielded apparently contradictory results on collision outcomes, only agreeing in a temperature dependence setting in above ≈210 K. By exploiting the unique capabilities of the NIMROD neutron scattering instrument, we characterized the bulk and surface structure of icy particles used in collision experiments, and studied how these structures alter as a function of temperature at a constant pressure of around 30 mbar. Our icy grains, formed under liquid nitrogen, undergo changes in the crystalline ice-phase, sublimation, sintering and surface pre-melting as they are heated from 103 to 247 K. An increase in the thickness of the diffuse surface layer from ≈10 to ≈30 Å (≈2.5 to 12 bilayers) proves increased molecular mobility at temperatures above ≈210 K. Because none of the other changes tie-in with the temperature trends in collisional outcomes, we conclude that the surface pre-melting phenomenon plays a key role in collision experiments at these temperatures. Consequently, the pressure–temperature environment, may have a larger influence on collision outcomes than previously thought.

  6. The shear-force/ultrasonic near-field microscope: a nanometrology tool for surface science and technology

    Science.gov (United States)

    La Rosa, A.; Li, N.; Asante, K.

    2005-11-01

    This paper describes recent results obtained with the Ultrasonic/Shear-Force Microscope (SUNM), an analytical tool suitable for investigating the quite different dynamic displayed by fluid-like films when subjected to mesoscopic confinement and while in intimate contact with two sliding solid boundaries. The SUNM uses two sensory modules to concurrently but independently monitor the effects that fluid-mediated interactions exert on two sliding bodies: the microscope's sharp probe (attached to a piezoelectric sensor) and the analyzed sample (attached to an ultrasonic transducer). This dual capability allows correlating the fluid-like film's viscoelastic properties with changes in the probe's resonance frequency and the generation of sound. A detailed monitoring of sliding friction by ultrasonic means and with nanometer resolution is unprecedented, which opens potential uses of the versatile microscope as a surface and subsurface material characterization tool. As a surface metrology tool, the SUNM presents a potential impact in diverse areas ranging from fundamental studies of nanotribology, confinement-driven solid to liquid phase transformation of polymer films, characterization of industrial lubricants, and the study of elastic properties of bio-membranes. As a sub-surface metrology tool, the SUNM can be used in the investigation of the elastic properties of low- and high-k dielectric materials, piezoelectric and ferroelectric films, as well as quality control in the construction of micro- and nano-fluidics devices.

  7. Acoustic propagation within a surface duct in the western Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    PrasannaKumar, S.; Navelkar, G.S.; Murty, T.V.R.; Murty, C.S.

    Sound speed structure forms a surface duct in the upper 50 m layer in the western Bay of Bengal during late July. A range-dependent acoustic ray computation shows that some rays emanating from a source within the upper 30 m, get trapped within...

  8. Measurements of size distributions of radon progeny for improved quantification of the lung cancer risk emanating from exposure to radon decay products; Messungen der Groessenverteilungen von Radon-Folgeprodukten zur Verbesserung der Quantifizierung des durch Radonexposition verursachten Lungenkrebsrisikos

    Energy Technology Data Exchange (ETDEWEB)

    Haninger, T.

    1997-12-31

    A major issue in radiation protection is to protect the population from the harmful effects of exposure to radon and radon progeny. Quantification of the lung cancer risk emanating from exposure to radon decay products in residential and working environments poses problems, as epidemiologic studies yield information deviating from the results obtained by the indirect method of assessment based on dosimetric respiratory tract models. One important task of the publication here was to characterize the various exposure conditions and to quantify uncertainties that may result from application of the ``dose conversion convention``. A special aerosol spectrometer was therefore designed and built in order to measure the size distributions of the short-lived radon decay products in the range between 0.5 nm and 10 000 nm. The aerosol spectrometer consists of a three-step diffusion battery with wire nets, an 11-step BERNER impactor, and a detector system with twelve large-surface proportional detectors. From the measured size distributions, dose conversion coefficients, E/P{sup eq}, were calculated using the PC software RADEP; the RADEP program was developed by BIRCHALL and JAMES and is based on the respiratory tract model of the ICRP. The E/P{sup eq} coefficients indicate the effective dose E per unit exposure P{sup eq} to radon decay products. (orig./CB) [Deutsch] Eines der groessten Probleme des Strahlenschutzes ist der Schutz der Bevoelkerung vor einer Strahlenexposition durch Radon und seine Folgeprodukte. Die Quantifizierung des Lungenkrebsrisikos, das durch Radonexpositionen in Wohnungen und an Arbeitsplaetzen verursacht wird, ist ein grosses Problem, weil epidemiologische Studien ein anderes Ergebnis liefern, als die indirekte Methode der Abschaetzung mit dosimetrischen Atemtrakt-Modellen. Eine wichtige Aufgabe der vorliegenden Arbeit war es, unterschiedliche Expositionsbedingungen zu charakterisieren und die Unsicherheiten zu quantifizieren, die sich aus der

  9. Helicon plasma generator-assisted surface conversion ion source for the production of H(-) ion beams at the Los Alamos Neutron Science Center.

    Science.gov (United States)

    Tarvainen, O; Rouleau, G; Keller, R; Geros, E; Stelzer, J; Ferris, J

    2008-02-01

    The converter-type negative ion source currently employed at the Los Alamos Neutron Science Center (LANSCE) is based on cesium enhanced surface production of H(-) ion beams in a filament-driven discharge. In this kind of an ion source the extracted H(-) beam current is limited by the achievable plasma density which depends primarily on the electron emission current from the filaments. The emission current can be increased by increasing the filament temperature but, unfortunately, this leads not only to shorter filament lifetime but also to an increase in metal evaporation from the filament, which deposits on the H(-) converter surface and degrades its performance. Therefore, we have started an ion source development project focused on replacing these thermionic cathodes (filaments) of the converter source by a helicon plasma generator capable of producing high-density hydrogen plasmas with low electron energy. In our studies which have so far shown that the plasma density of the surface conversion source can be increased significantly by exciting a helicon wave in the plasma, and we expect to improve the performance of the surface converter H(-) ion source in terms of beam brightness and time between services. The design of this new source and preliminary results are presented, along with a discussion of physical processes relevant for H(-) ion beam production with this novel design. Ultimately, we perceive this approach as an interim step towards our long-term goal, combining a helicon plasma generator with an SNS-type main discharge chamber, which will allow us to individually optimize the plasma properties of the plasma cathode (helicon) and H(-) production (main discharge) in order to further improve the brightness of extracted H(-) ion beams.

  10. A Radial Pattern of Six Paleo Ice Streams Emanating from the Bruce Plateau Ice Dome, Antarctic Peninsula Ice Sheet: Constraints from Multibeam Bathymetry and GPS Rebound

    Science.gov (United States)

    Fried, M.; Domack, E.; Canals, M.; Casamor, J.; King, M.

    2008-12-01

    We reconstructed ice thicknesses along six paleo ice streams emanating out of the Bruce Plateau in the Northern Antarctic Peninsula. This was done in order to generate models of potential isostatic rebound along the flow paths since the LGM and thereby provide a theoretical test for empirical observations of vertical displacement (rebound) as measured by seven coastal GPS stations (to be deployed during the current IPY- LARISSA project). This study is pertinent to realizing the effect of moderate ice sheet size during collapse and resulting sea level rise. The Palmer, Vernadsky, Hugo Island and Gerlache and Boyd Strait ice stream paths (flow lines) were highlighted on the Western side of the Peninsula. The Drygalski, Crane and Hektoria ice streams were studied on the Eastern side. Using detailed and near complete swath bathymetry data available for the Western Peninsula coastal region and partial swath mapping data generated at the site of the former Larsen B ice shelf (and Roberston Trough), we constructed hypothetical longitudinal profiles of all six ice streams along precisely located flow paths. These profiles extended from the accumulation zones in the upper elevations of the Bruce Plateau to the terminus along the continental shelf edge. The profiles included detailed elevations of the bedrock and hypothetical ice thickness values along the ice streams as they would have been during the Last Glacial Maximum (~ 16 ka). Ice thickness values were based on the elevations of bedrock, trim lines, surrounding topography, influence of surrounding glaciers and previous estimates of LGM ice thickness values around the Antarctic Peninsula. Using the components of the hypothetical longitudinal profiles, total isostatic rebound since the LGM can be calculated for the region (assuming reasonable mantle viscosities). In all the profiles reconstructed ice thicknesses are characterized by an order of magnitude increase across inner shelf troughs (such as the Palmer Deep and

  11. Science Notes.

    Science.gov (United States)

    School Science Review, 1990

    1990-01-01

    Presented are 25 science activities on colorations of prey, evolution, blood, physiology, nutrition, enzyme kinetics, leaf pigments, analytical chemistry, milk, proteins, fermentation, surface effects of liquids, magnetism, drug synthesis, solvents, wintergreen synthesis, chemical reactions, multicore cables, diffraction, air resistance,…

  12. A Miniaturized Variable Pressure Scanning Electron Microscope (MVP-SEM) for the Surface of Mars: An Instrument for the Planetary Science Community

    Science.gov (United States)

    Edmunson, J.; Gaskin, J. A.; Danilatos, G.; Doloboff, I. J.; Effinger, M. R.; Harvey, R. P.; Jerman, G. A.; Klein-Schoder, R.; Mackie, W.; Magera, B.; hide

    2016-01-01

    The Miniaturized Variable Pressure Scanning Electron Microscope(MVP-SEM) project, funded by the NASA Planetary Instrument Concepts for the Advancement of Solar System Observations (PICASSO) Research Opportunities in Space and Earth Science (ROSES), will build upon previous miniaturized SEM designs for lunar and International Space Station (ISS) applications and recent advancements in variable pressure SEM's to design and build a SEM to complete analyses of samples on the surface of Mars using the atmosphere as an imaging medium. By the end of the PICASSO work, a prototype of the primary proof-of-concept components (i.e., the electron gun, focusing optics and scanning system)will be assembled and preliminary testing in a Mars analog chamber at the Jet Propulsion Laboratory will be completed to partially fulfill Technology Readiness Level to 5 requirements for those components. The team plans to have Secondary Electron Imaging(SEI), Backscattered Electron (BSE) detection, and Energy Dispersive Spectroscopy (EDS) capabilities through the MVP-SEM.

  13. Professional learning communities (PLCs) for early childhood science education

    Science.gov (United States)

    Eum, Jungwon

    This study explored the content, processes, and dynamics of Professional Learning Community (PLC) sessions. This study also investigated changes in preschool teachers' attitudes and beliefs toward science teaching after they participated in two different forms of PLCs including workshop and face-to-face PLC as well as workshop and online PLC. Multiple sources of data were collected for this study including participant artifacts and facilitator field notes during the PLC sessions. The participants in this study were eight teachers from NAEYC-accredited child care centers serving 3- to 5-year-old children in an urban Midwest city. All teachers participated in a workshop entitled, "Ramps and Pathways." Following the workshop, the first group engaged in face-to-face PLC sessions and the other group engaged in online PLC sessions. Qualitative data were collected through audio recordings, online archives, and open-ended surveys. The teachers' dialogue during the face-to-face PLC sessions was audiotaped, transcribed, and analyzed for emerging themes. Online archives during the online PLC sessions were collected and analyzed for emerging themes. Four main themes and 13 subthemes emanated from the face-to-face sessions, and 3 main themes and 7 subthemes emanated from the online sessions. During the face-to-face sessions, the teachers worked collaboratively by sharing their practices, supporting each other, and planning a lesson together. They also engaged in inquiry and reflection about their science teaching and child learning in a positive climate. During the online sessions, the teachers shared their thoughts and documentation and revisited their science teaching and child learning. Five themes and 15 subthemes emanated from the open-ended survey responses of face-to-face group teachers, and 3 themes and 7 subthemes emanated from the open-ended survey responses of online group teachers. Quantitative data collected in this study showed changes in teachers' attitudes and

  14. Science and Science Fiction

    Science.gov (United States)

    Oravetz, David

    2005-01-01

    This article is for teachers looking for new ways to motivate students, increase science comprehension, and understanding without using the old standard expository science textbook. This author suggests reading a science fiction novel in the science classroom as a way to engage students in learning. Using science fiction literature and language…

  15. Mr. Matan Vilnai, Israeli Minister of Science, Culture and Sport visited CERN on 20 March

    CERN Multimedia

    Laurent Guiraud

    2000-01-01

    No 17: Mr. Yuval Ne\\'eman, director of the centre for advanced studies at Tel-Aviv University, explains the standard model of physics to the Minister. No 20 : left to right, H.E. Mr. David Peleg, Ambassador and Permanent Representative of Israel to the UN, Minister Vilnai, Professor Hagit Meser Yaron, Chief Scientist at the Ministry of Science, Culture and Sport, and Mr. Nachman Shai, Director General of the Ministry with Giora Mikenberg, ATLAS and OPAL physicist

  16. Science and data science.

    Science.gov (United States)

    Blei, David M; Smyth, Padhraic

    2017-08-07

    Data science has attracted a lot of attention, promising to turn vast amounts of data into useful predictions and insights. In this article, we ask why scientists should care about data science. To answer, we discuss data science from three perspectives: statistical, computational, and human. Although each of the three is a critical component of data science, we argue that the effective combination of all three components is the essence of what data science is about.

  17. Calibration of a degassing-emanation line for 222Rn determination in seawater samples; Calibracao de uma linha de emanacao para determinacao de {sup 222}Rn em amostras de agua do mar

    Energy Technology Data Exchange (ETDEWEB)

    Farias, Luciana Aparecida

    2002-07-01

    The purpose of this study is to calibrate a degassing-emanation line and to determine {sup 222}Rn and {sup 226}Ra activity concentrations in seawater samples. This methodology, also called Lucas method, consists in the extraction of radon (originally dissolved in seawater), collection of the gas in a liquid nitrogen cold trap and transfer from the trap to an alpha scintillation cell. Total extraction efficiencies of the 4 degassing-emanation systems were determined by measuring {sup 226}Ra reference solutions. The efficiencies obtained for these 4 systems varied from 21 % to 62%. This work also presents preliminary results of a study carried out in a series of small embayements of Ubatuba, Sao Paulo State-Brazil: Flamengo Bay, Fortaleza Bay, Mar Virado Bay and Ubatuba Bay. Concentration of Rn in excess varied from 0,011 to 0,317 Bq/L for Flamengo Bay, from 0,009 to 0,130 Bq/L for Fortaleza Bay, from 0,018 to 0,050 Bq/L for Mar Virado Bay and from 0,004 to 0,120 Bq/L for Ubatuba Bay. The results obtained for the concentration of {sup 222}Rn in excess in a transect at Flamengo Bay varied from 0,002 to 0,036 Bq/L. Higher concentrations of {sup 222}Rn in excess were obtained in Flamengo Bay, Fortaleza Bay and Ubatuba bay. It was also observed that the concentration of {sup 222}Rn in excess increases with depth, as expected. (author)

  18. The achievements of solar children from the natural created octave whose source is the emanating sun reflected by the Foundation for Solar Achievement with the Arts

    Energy Technology Data Exchange (ETDEWEB)

    Petacchi, D.V. [Foundation for Solar Achievement with the Arts, Hobart, NY (United States)

    1997-12-31

    The Foundation for Solar Achievement With The Arts is a not-for-profit school training gifted children in the use of their talent in accordance with the philosophy and experience that children in harmony with their natural environment based upon the sun`s position in the course of the day have the greater capacity of attention necessary to enhance learning and creativity. Uncluttered as much as possible by the distractions of technology or the artificial glare of electricity, the learning environment of the Foundation for Solar Achievement With The Arts is conducive to this hands-on action. The Foundation was started by an individual whose life long search for the meaning of his life and whose pondering on the meaning human life on this planet led him to many conclusions modern science is just beginning to reach. With the help of dedicated architect John Jehring and likeminded others, Mr. Petacchi is utilizing natural sunlight in an environment conducive to the psyche of children. A building is planned that will expand into indoor form the natural lighting and free space of the out-of-doors.

  19. The achievements of solar children from the natural created octave whose source is the emanating sun reflected by the Foundation for Solar Achievement with the Arts

    International Nuclear Information System (INIS)

    Petacchi, D.V.

    1997-01-01

    The Foundation for Solar Achievement With The Arts is a not-for-profit school training gifted children in the use of their talent in accordance with the philosophy and experience that children in harmony with their natural environment based upon the sun's position in the course of the day have the greater capacity of attention necessary to enhance learning and creativity. Uncluttered as much as possible by the distractions of technology or the artificial glare of electricity, the learning environment of the Foundation for Solar Achievement With The Arts is conducive to this hands-on action. The Foundation was started by an individual whose life long search for the meaning of his life and whose pondering on the meaning human life on this planet led him to many conclusions modern science is just beginning to reach. With the help of dedicated architect John Jehring and likeminded others, Mr. Petacchi is utilizing natural sunlight in an environment conducive to the psyche of children. A building is planned that will expand into indoor form the natural lighting and free space of the out-of-doors

  20. Science in Science Fiction.

    Science.gov (United States)

    Allday, Jonathan

    2003-01-01

    Offers some suggestions as to how science fiction, especially television science fiction programs such as "Star Trek" and "Star Wars", can be drawn into physics lessons to illuminate some interesting issues. (Author/KHR)

  1. Science in Computational Sciences

    Directory of Open Access Journals (Sweden)

    Jameson Cerrosen

    2012-12-01

    Full Text Available The existing theory in relation to science presents the physics as an ideal, although many sciences not approach the same, so that the current philosophy of science-Theory of Science- is not much help when it comes to analyze the computer science, an emerging field of knowledge that aims investigation of computers, which are included in the materialization of the ideas that try to structure the knowledge and information about the world. Computer Science is based on logic and mathematics, but both theoretical research methods and experimental follow patterns of classical scientific fields. Modeling and computer simulation, as a method, are specific to the discipline and will be further developed in the near future, not only applied to computers but also to other scientific fields. In this article it is analyze the aspects of science in computer science, is presenting an approach to the definition of science and the scientific method in general and describes the relationships between science, research, development and technology.

  2. Multifunctional Interface Facility for Receiving and Processing Planetary Surface Materials for Science Investigation and Resource Evaluation at the Deep Space Gateway

    Science.gov (United States)

    Sibille, L.; Mantovani, J. G.; Townsend, I. I.; Mueller, R. P.

    2018-02-01

    The concepts describe hardware and instrumentation for the study of planetary surface materials at the Deep Space Gateway as a progressive evolution of capabilities for eliminating the need for special handling and Planetary Protection (PP) protocols inside the habitats.

  3. Acidic deposition: State of science and technology. Report 9. Current status of surface-water acid-base chemistry. Final report

    International Nuclear Information System (INIS)

    Baker, L.A.; Kaufmann, P.R.; Brakke, D.F.; Herlihy, A.T.; Eilers, J.M.

    1990-09-01

    The report is based largely upon the National Surface Water Survey (NSWS), augmented by numerous smaller state and university surveys and many detailed watershed studies. In describing the current status of surface waters, the authors go far beyond the description of population statistics, although some of this is necessary, and direct their attention to the interpretation of these data. They address the question of the sources of acidity to surface waters in order to determine the relative importance of acidic deposition compared with other sources, such as naturally produced organic acids and acid mine drainage. They also examine in some detail what they call 'high interest' populations-the specific groups of lakes and streams most likely to be impacted by acidic deposition. The authors then turn to the general question of uncertainty, and finally examine low alkalinity surface waters in several other parts of the world to develop further inferences about the acid-base status of surface waters in the United States

  4. Bulletin of Materials Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. R Sarathi. Articles written in Bulletin of Materials Science. Volume 24 Issue 6 December 2001 pp 587-593 Surface Studies. Investigation of surface modifications in ethylene propylene diene monomer (EPDM) rubber due to tracking under a.c. and d.c. voltages · R Sarathi Uma ...

  5. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. S C Arunchandra. Articles written in Journal of Earth System Science. Volume 117 Issue 6 December 2008 pp 911-923. On the measurement of the surface energy budget over a land surface during the summer monsoon · G S Bhat S C Arunchandra · More Details Abstract ...

  6. Acidic deposition: State of science and technology. Report 14. Methods for projecting future changes in surface water acid-base chemistry. Final report

    International Nuclear Information System (INIS)

    Thornton, K.W.; Marmorek, D.; Ryan, P.F.; Heltcher, K.; Robinson, D.

    1990-09-01

    The objectives of the report are to: critically evaluate methods for projecting future effects of acidic deposition on surface water acid-base chemistry; review and evaluate techniques and procedures for analyzing projection uncertainty; review procedures for estimating regional lake and stream population attributes; review the U.S. Environmental Protection Agency (EPA) Direct/Delayed Response Project (DDRP) methodology for projecting the effects of acidic deposition on future changes in surface water acid-base chemistry; and present the models, uncertainty estimators, population estimators, and proposed approach selected to project the effects of acidic deposition on future changes in surface water acid-base chemistry in the NAPAP 1990 Integrated Assessment and discuss the selection rationale

  7. Science of science.

    Science.gov (United States)

    Fortunato, Santo; Bergstrom, Carl T; Börner, Katy; Evans, James A; Helbing, Dirk; Milojević, Staša; Petersen, Alexander M; Radicchi, Filippo; Sinatra, Roberta; Uzzi, Brian; Vespignani, Alessandro; Waltman, Ludo; Wang, Dashun; Barabási, Albert-László

    2018-03-02

    Identifying fundamental drivers of science and developing predictive models to capture its evolution are instrumental for the design of policies that can improve the scientific enterprise-for example, through enhanced career paths for scientists, better performance evaluation for organizations hosting research, discovery of novel effective funding vehicles, and even identification of promising regions along the scientific frontier. The science of science uses large-scale data on the production of science to search for universal and domain-specific patterns. Here, we review recent developments in this transdisciplinary field. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  8. 21 March 2011 - South African Ministry of Science and Technology, Department of Science and Technology (DST) Director General P. Mjwara signing the guest with Head of International Relations F. Pauss and Adviser J. Ellis and ALICE Collaboration Spokesperson P. Giubellino and J. Cleymans; in the CERN control centre with R. Steerenberg; visiting ALICE surface exhibition with P. Giubellino and LHC superconducting magnet test hall with L. Bottura.

    CERN Multimedia

    Maximilien Brice

    2011-01-01

    21 March 2011 - South African Ministry of Science and Technology, Department of Science and Technology (DST) Director General P. Mjwara signing the guest with Head of International Relations F. Pauss and Adviser J. Ellis and ALICE Collaboration Spokesperson P. Giubellino and J. Cleymans; in the CERN control centre with R. Steerenberg; visiting ALICE surface exhibition with P. Giubellino and LHC superconducting magnet test hall with L. Bottura.

  9. Associateship | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Fellowship; Associateship. Associate Profile. Period: 2016–2019. Bhattacharya, Dr Atanu Ph.D. (Colorado State). Date of birth: 2 March 1983. Specialization: Ultrafast Science, Surface Science, Molecular Beam Experiments Address: IPC Department, Indian Institute of Science, Bengaluru 560 012, Karnataka Contact:

  10. Sadhana | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Design of fair surfaces over irregular domains is a fundamental problem in computer-aided geometric design (CAGD), and has applications in engineering sciences (in aircraft, automobile, ship science etc.). In the design of fair surfaces over irregular domains defined over scattered data, it was widely accepted till recently ...

  11. Science Smiles

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. Science Smiles. Articles in Resonance – Journal of Science Education. Volume 1 Issue 4 April 1996 pp 4-4 Science Smiles. Chief Editor's column / Science Smiles · R K Laxman · More Details Fulltext PDF. Volume 1 Issue 5 May 1996 pp 3-3 Science Smiles.

  12. Educational Experiences in Oceanography through Hands-On Involvement with Surface Drifters: an Introduction to Ocean Currents, Engineering, Data Collection, and Computer Science

    Science.gov (United States)

    Anderson, T.

    2015-12-01

    The Northeast Fisheries Science Center's (NEFSC) Student Drifters Program is providing education opportunities for students of all ages. Using GPS-tracked ocean drifters, various educational institutions can provide students with hands-on experience in physical oceanography, engineering, and computer science. In building drifters many high school and undergraduate students may focus on drifter construction, sometimes designing their own drifter or attempting to improve current NEFSC models. While learning basic oceanography younger students can build drifters with the help of an educator and directions available on the studentdrifters.org website. Once drifters are deployed, often by a local mariner or oceanographic partner, drifter tracks can be visualised on maps provided at http://nefsc.noaa.gov/drifter. With the lesson plans available for those interested in computer science, students may download, process, and plot the drifter position data with basic Python code provided. Drifter tracks help students to visualize ocean currents, and also allow them to understand real particle tracking applications such as in search and rescue, oil spill dispersion, larval transport, and the movement of injured sea animals. Additionally, ocean circulation modelers can use student drifter paths to validate their models. The Student Drifters Program has worked with over 100 schools, several of them having deployed drifters on the West Coast. Funding for the program often comes from individual schools and small grants but in the future will preferably come from larger government grants. NSF, Sea-Grant, NOAA, and EPA are all possible sources of funding, especially with the support of multiple schools and large marine education associations. The Student Drifters Program is a unique resource for educators, students, and scientists alike.

  13. Science or Science Fiction?

    DEFF Research Database (Denmark)

    Lefsrud, Lianne M.; Meyer, Renate

    2012-01-01

    This paper examines the framings and identity work associated with professionals’ discursive construction of climate change science, their legitimation of themselves as experts on ‘the truth’, and their attitudes towards regulatory measures. Drawing from survey responses of 1077 professional......, legitimation strategies, and use of emotionality and metaphor. By linking notions of the science or science fiction of climate change to the assessment of the adequacy of global and local policies and of potential organizational responses, we contribute to the understanding of ‘defensive institutional work...

  14. The effect of additives on the reactivity of palladium surfaces for the chemisorption and hydrogenation of carbon monoxide: A surface science and catalytic study. [LaMO/sub 3/(M = Cr, Mn, Fe, Co, Rh)

    Energy Technology Data Exchange (ETDEWEB)

    Rucker, T.G.

    1987-06-01

    This research studied the role of surface additives on the catalytic activity and chemisorptive properties of Pd single crystals and foils. Effects of Na, K, Si, P, S, and Cl on the bonding of CO and H and on the cyclotrimerization of acetylene on the (111), (100) and (110) faces of Pd were investigated in addition to role of TiO/sub 2/ and SiO/sub 2/ overlayers deposited on Pd foils in the CO hydrogenation reaction. On Pd, only in the presence of oxide overlayers, are methane or methanol formed from CO and H/sub 2/. The maximum rate of methane formation is attained on Pd foil where 30% of the surface is covered with titania. Methanol formation can be achieved only if the TiO/sub x//Pd surface is pretreated in 50 psi of oxygen at 550/sup 0/C prior to the reaction. The additives (Na, K, Si, P, S, Cl) affect the bonding of CO and hydrogen and the cyclotrimerization of acetylene to benzene by structural and electronic interactions. In general, the electron donating additives increase the desorption temperature of CO and increase the rate of acetylene cyclotrimerization and the electron withdrawing additives decrease the desorption temperature of CO and decrease the rate of benzene formation from acetylene.

  15. Invasive plants often emanate from southern gardens

    Science.gov (United States)

    J.H. Miller; A. Miller

    2009-01-01

    Did you know that heavenly bamboo, thorny olive, English ivy, Boston fern, privets and many garden favorites are invading forests to their and thus our detriment? Garden clubs should band together to protect our natural vegetation against invasive plants that take over the habitat of the native flora. Often called non-native, exotic, or noxious weeds, they...

  16. Temporal relationships between the variations of diffuse gaseous emanations and the explosive activity of some active volcanoes of Costa-Rica, examples at the Arenal, Irazu and at the Rincon de la Vieja; Relations temporelles entre les variations des emanations gazeuses diffuses et l`activite explosive de quelques volcans actifs du Costa-Rica, exemples a l`Arenal, l`Irazu et au Rincon de la Vieja

    Energy Technology Data Exchange (ETDEWEB)

    Baubron, J.C. [BRGM, 45 - Orleans (France); Allard, P. [CEA Centre d`Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France). Direction des Sciences de la Matiere; Fernandez, E. [Obviscori, Heridia (Costa Rica); Hammouya, G. [Observatoire de la Soufriere, IPG-P, le Houelmont, 97 - Gourgeyre (France); Soto, G.J. [ICE, San Jose (Costa Rica)

    1996-12-31

    The surveillance of the temporal evolution of radon and helium concentrations in the carbon dioxide of crater fumaroles and gaseous emanations is performed since 1992 on the Irazu, Arenal, Poas and Rincon de la Vieja volcanoes in Costa-Rica. The {sup 3}He/{sup 4}He ratio is used as an indicator of the deep origin of the volcanic gas while radon is an indicator of the CO{sub 2} flux. Radon measurements performed on the Irazu show a continuous decay of radon concentration in the intra-crater fumaroles with an important increase of the gaseous flux since 1992. On the contrary, the external fumaroles on the NW flank were characterized by an important increase in radon concentration in 1994 with a stable flux. The radon surveillance performed in soils around the volcano has shown an intense increase of the diffuse gaseous flows probably linked to the micro-seismic activity of the volcano. Similar observations are reported for the Rincon de la Vieja volcano and correlated with its eruptive history and its phreatic and phreato-magmatic activity. Short paper. (J.S.).

  17. Behavioral dental science: the relationship between tooth-brushing angle and plaque removal at the lingual surfaces of the posterior teeth in the mandible.

    Science.gov (United States)

    Sasahara, H; Kawamura, M

    2000-06-01

    The aim of this study was to investigate the relationship between tooth-brushing angle and efficacy of plaque removal. The subjects in this study were 72 students (18-21 yrs.) from paramedical schools. They answered the questionnaire of the Hiroshima University-Dental Behavioral Inventory (HU-DBI) to assess dental health behavior, and then received examinations of tooth-brushing angle, efficacy of plaque removal and gingival condition. The examination sites of tooth-brushing angle and the efficacy of plaque removal were the lingual surfaces of the posterior teeth in the mandible. The tooth-brushing angle, efficacy of plaque removal, gingival condition and dental health behavior were significantly associated with each other. The subjects who directed the bristles of the toothbrush vertically toward the tooth surfaces had a high efficacy of plaque removal, good gingival condition and good dental health behavior. Thus, it is important to direct the bristles vertically toward the tooth surfaces for effective plaque removal. In addition, knowledge related to good dental health might be necessary to carry out effective tooth brushing.

  18. Fundamental research on surface science of coal in support of physical beneficiation of coal: Quarterly technical progress report, January 1--March 31, 1989

    Energy Technology Data Exchange (ETDEWEB)

    Good, R. J.; Keller, Jr., D. V.

    1989-01-01

    Research on coal surfaces continued. Our contact angle study of the decane-water-coal system has been extended using various ranks of coal. The study of the effect of surface oxidation on contact angles has also been extended to Upper Freeport, Illinois No. 6 and Kentucky No. 9 coals. Measurements of contact angles of liquid-air interfaces, on polished surfaces of coal of two different ranks, have been made using the captive drop technique. The data have been analyses using the acid/base theory. Some preliminary contact angle measurements have been made on rock pyrite, using the microscopic technique. The measurements were carried out for decane-water interfaces. A study of laboratory-scale agglomeration has been undertaken, using an Osterizer blender. The coals used were Illinois No. 6 and Kentucky No. 9. The effect of CO/sub 2/ on the agglomeration process has been looked into. Finally, the adsorption alcohols (cyclohexanol and n-octanol) from both aqueous and non-aqueous solutions, onto coal, has been measured. Two ranks of coal were used: Upper Freeport (mvb) and Illinois No. 6 (hvcb). 9 refs., 6 figs., 17 tabs.

  19. Mars Science Laboratory Sample Acquisition, Sample Processing and Handling Subsystem: A Description of the Sampling Functionality of the System after being on the Surface for Two Years.

    Science.gov (United States)

    Beegle, L. W.; Anderson, R. C.; Abbey, W. J.

    2014-12-01

    The Sample Acquisition/Sample Processing and Handling (SA/SPaH) subsystem for the Mars Science Library (MSL) is a rover-based sampling system. SA/SPaH consists of a powdering drill and a scooping, sieving, and portioning device mounted on a turret at the end of a robotic arm. Curiosity rover preformed several sample acquisitions and processing of solid samples during its first year of operation. Material were processed and delivered to the two analytical instruments, Chemistry and Mineralogy (CheMin) and Sample Analysis at Mars (SAM), both of which required specific particle size for the material delivered to them to perform their analysis to determine its mineralogy and geochemistry content. In this presentation, the functionality of the system will be explained along with the in-situ targets the system has acquire and the samples that were delivered.

  20. Near-surface temperature gradients and their effects on thermal-infrared emission spectra of particulate planetary surfaces

    Science.gov (United States)

    Henderson, B. G.; Jakosky, B. M.

    1993-01-01

    The infrared energy emitted from a planetary surface is generated within a finite depth determined by the material's absorption skin depth. This parameter varies significantly with wavelength in the infrared but has an average value of around 50 microns for most geologic materials. In solid rock, heat transfer is efficient enough so that this 50 micron zone of the near surface from which the radiation emanates will be more or less isothermal. In particulate materials, however, heat transfer is more complicated and occurs via a combination of mechanisms, including solid conduction within grains and across grain contacts, conduction through the interstitial gas, and thermal radiation within individual particles and across the void spaces in between grains. On planets with substantial atmospheres, the gas component dominates the heat transfer and tends to mitigate near-surface thermal gradients. However, on airless bodies, the gas component is absent and heat transfer occurs via solid conductions and radiation. If the particles are small relative to the average absorption skin depth, then the top 50-100 microns or so of the surface will be cooled by radiation to space allowing the creation of significant near-surface thermal gradients. In those regions of the spectrum where the absorption coefficient is low, the emission will come from the deeper, warmer parts of the medium, whereas in regions of high absorption, the emission will emanate from shallower, cooler parts of the medium. The resulting emission spectrum will show non-compositional features as a result of the thermal structure in the material. We have modeled the heat transfer in a particulate medium in order to determine the magnitude of near-surface thermal gradients for surfaces on airless bodies and on Mars. We use the calculated thermal structure to determine the effects it has on the infrared emission spectrum of the surface.

  1. Primary Science Interview: Science Sparks

    Science.gov (United States)

    Bianchi, Lynne

    2016-01-01

    In this "Primary Science" interview, Lynne Bianchi talks with Emma Vanstone about "Science Sparks," which is a website full of creative, fun, and exciting science activity ideas for children of primary-school age. "Science Sparks" started with the aim of inspiring more parents to do science at home with their…

  2. The surface energy of metals

    DEFF Research Database (Denmark)

    Vitos, Levente; Ruban, Andrei; Skriver, Hans Lomholt

    1998-01-01

    We have used density functional theory to establish a database of surface energies for low index surfaces of 60 metals in the periodic table. The data may be used as a consistent starting point for models of surface science phenomena. The accuracy of the database is established in a comparison...

  3. Communicating Science

    Science.gov (United States)

    Russell, Nicholas

    2009-10-01

    Introduction: what this book is about and why you might want to read it; Prologue: three orphans share a common paternity: professional science communication, popular journalism, and literary fiction are not as separate as they seem; Part I. Professional Science Communication: 1. Spreading the word: the endless struggle to publish professional science; 2. Walk like an Egyptian: the alien feeling of professional science writing; 3. The future's bright? Professional science communication in the age of the internet; 4. Counting the horse's teeth: professional standards in science's barter economy; 5. Separating the wheat from the chaff: peer review on trial; Part II. Science for the Public: What Science Do People Need and How Might They Get It?: 6. The Public Understanding of Science (PUS) movement and its problems; 7. Public engagement with science and technology (PEST): fine principle, difficult practice; 8. Citizen scientists? Democratic input into science policy; 9. Teaching and learning science in schools: implications for popular science communication; Part III. Popular Science Communication: The Press and Broadcasting: 10. What every scientist should know about mass media; 11. What every scientist should know about journalists; 12. The influence of new media; 13. How the media represents science; 14. How should science journalists behave?; Part IV. The Origins of Science in Cultural Context: Five Historic Dramas: 15. A terrible storm in Wittenberg: natural knowledge through sorcery and evil; 16. A terrible storm in the Mediterranean: controlling nature with white magic and religion; 17. Thieving magpies: the subtle art of false projecting; 18. Foolish virtuosi: natural philosophy emerges as a distinct discipline but many cannot take it seriously; 19. Is scientific knowledge 'true' or should it just be 'truthfully' deployed?; Part V. Science in Literature: 20. Science and the Gothic: the three big nineteenth-century monster stories; 21. Science fiction: serious

  4. Dragonfly Mercury Project—A citizen science driven approach to linking surface-water chemistry and landscape characteristics to biosentinels on a national scale

    Science.gov (United States)

    Eagles-Smith, Collin A.; Nelson, Sarah J.; Willacker,, James J.; Flanagan Pritz, Colleen M.; Krabbenhoft, David P.

    2016-02-29

    Mercury is a globally distributed pollutant that threatens human and ecosystem health. Even protected areas, such as national parks, are subjected to mercury contamination because it is delivered through atmospheric deposition, often after long-range transport. In aquatic ecosystems, certain environmental conditions can promote microbial processes that convert inorganic mercury to an organic form (methylmercury). Methylmercury biomagnifies through food webs and is a potent neurotoxicant and endocrine disruptor. The U.S. Geological Survey (USGS), the University of Maine, and the National Park Service (NPS) Air Resources Division are working in partnership at more than 50 national parks across the United States, and with citizen scientists as key participants in data collection, to develop dragonfly nymphs as biosentinels for mercury in aquatic food webs. To validate the use of these biosentinels, and gain a better understanding of the connection between biotic and abiotic pools of mercury, this project also includes collection of landscape data and surface-water chemistry including mercury, methylmercury, pH, sulfate, and dissolved organic carbon and sediment mercury concentration. Because of the wide geographic scope of the research, the project also provides a nationwide “snapshot” of mercury in primarily undeveloped watersheds.

  5. Acidic deposition: State of science and technology. Report 10. Watershed and lake processes affecting surface-water acid-base chemistry. Final report

    International Nuclear Information System (INIS)

    Turner, R.S.; Cook, R.B.; Miegroet, H.V.; Johnson, D.W.; Elwood, J.W.

    1990-09-01

    The acid-base chemistry of surface waters is governed by the amount and chemistry of deposition and by the biogeochemical reactions that generate acidity or acid neutralizing capacity (ANC) along the hydrologic pathways that water follows through watersheds to streams and lakes. The amount of precipitation and it chemical loading depend on the area's climate and physiography, on it proximity to natural or industrial gaseous or particulate sources, and on local or regional air movements. Vegetation interacts with the atmosphere to enhance both wet and dry deposition of chemicals to a greater or lesser extent, depending on vegetation type. Vegetation naturally acidifies the environment in humid regions through processes of excess base cation uptake and generation of organic acids associated with many biological processes. Natural acid production and atmospheric deposition of acidic materials drive the acidification process. The lake or stream NAC represents a balance between the acidity-and ANC-generating processes that occur along different flow paths in the watershed and the relative importance of each flow path

  6. Food Science.

    Science.gov (United States)

    Barkman, Susan J.

    1996-01-01

    Presents food science experiments designed for high school science classes that aim at getting students excited about science and providing them with real-life applications. Enables students to see the application of chemistry, microbiology, engineering, and other basic and applied sciences to the production, processing, preservation, evaluation,…

  7. Science/s.

    Directory of Open Access Journals (Sweden)

    Emmanuelle Tricoire

    2005-03-01

    Full Text Available Un forum a été organisé en mars par la Commission européenne. Il s’appelait « Science in Society ». Depuis 2000 la Commission a mis en place un Plan d’Action élaboré pour que soit promue « la science » au sein du public, afin que les citoyens prennent de bonnes décisions, des décisions informées. Il s’agit donc de développer la réflexivité au sein de la société, pour que cette dernière agisse avec discernement dans un monde qu’elle travaille à rendre durable. ...

  8. Science Fiction and Science Education.

    Science.gov (United States)

    Cavanaugh, Terence

    2002-01-01

    Uses science fiction films such as "Jurassic Park" or "Anaconda" to teach science concepts while fostering student interest. Advocates science fiction as a teaching tool to improve learning and motivation. Describes how to use science fiction in the classroom with the sample activity Twister. (YDS)

  9. Adsorption of Hazardous Compounds to Mineral Surfaces

    National Research Council Canada - National Science Library

    Carron, Keith

    1997-01-01

    The project entitled 'Adsorption of Hazardous Compounds to Mineral Surfaces' involved five faculty members from the University of Wyoming's Departments of Chemistry, Geology, Soil Science, and Mathematics...

  10. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. J Barnes. Articles written in Journal of Earth System Science. Volume 115 Issue 4 August 2006 pp 451-460 Special Section on: Material exchanges at marine boundaries and surface ocean processes: Forcings and feedbacks. Spatial and temporal distribution of methane in ...

  11. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. P V Rajesh. Articles written in Journal of Earth System Science. Volume 125 Issue 4 June 2016 pp 691-708. Sensitivity of tropical cyclone characteristics to the radial distribution of sea surface temperature · Deepika Rai S Pattnaik P V Rajesh · More Details Abstract Fulltext ...

  12. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. P N Preenu. Articles written in Journal of Earth System Science. Volume 126 Issue 5 July 2017 pp 76. Variability of the date of monsoon onset over Kerala (India) of the period 1870–2014 and its relation to sea surface temperature · P N Preenu P V Joseph P K Dineshkumar.

  13. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. P K Pal. Articles written in Journal of Earth System Science. Volume 113 Issue 1 March 2004 pp 89-101. Artificial neural network approach for estimation of surface specific humidity and air temperature using Multifrequency Scanning Microwave Radiometer · Randhir Singh ...

  14. Bulletin of Materials Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. YUTING HUANG. Articles written in Bulletin of Materials Science. Volume 40 Issue 6 October 2017 pp 1137-1149. Facile synthesis and characterization of rough surface V 2 O 5 nanomaterials for pseudo-supercapacitor electrode material with high capacitance · YIFU ZHANG ...

  15. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. T N Krishnamurti. Articles written in Journal of Earth System Science. Volume 115 Issue 2 April 2006 pp 185-201. Transitions in the surface energy balance during the life cycle of a monsoon season · T N Krishnamurti Mrinal K Biswas · More Details Abstract Fulltext PDF.

  16. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. Rajesh Sikhakolli. Articles written in Journal of Earth System Science. Volume 122 Issue 1 February 2013 pp 187-199. Evaluation of OSCAR ocean surface current product in the tropical Indian Ocean using in situ data · Rajesh Sikhakolli Rashmi Sharma Sujit Basu B S ...

  17. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. V B Sumithranand. Articles written in Journal of Earth System Science. Volume 119 Issue 4 August 2010 pp 507-517. Variability of soil moisture and its relationship with surface albedo and soil thermal diffusivity at Astronomical Observatory, Thiruvananthapuram, south ...

  18. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. P Senthil Kumar. Articles written in Journal of Earth System Science. Volume 119 Issue 5 October 2010 pp 745-751. Soil-gas helium and surface-waves detection of fault zones in granitic bedrock · G K Reddy T Seshunarayana Rajeev Menon P Senthil Kumar · More Details ...

  19. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. G Rajagopalan. Articles written in Journal of Earth System Science. Volume 109 Issue 1 March 2000 pp 153-156. Glacial-interglacial changes in the surface water characteristics of the Andaman Sea: Evidence from stable ratios of planktonic foraminifera · S M Ahmad D J ...

  20. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. Sunil Peshin. Articles written in Journal of Earth System Science. Volume 121 Issue 2 April 2012 pp 373-383. Surface ozone scenario at Pune and Delhi during the decade of 1990s · Kaushar Ali S R Inamdar G Beig S Ghude Sunil Peshin · More Details Abstract Fulltext PDF.

  1. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. Bhawanisingh G Desai. Articles written in Journal of Earth System Science. Volume 120 Issue 4 August 2011 pp 723-734. Discontinuity surfaces and event stratigraphy of Okha Shell Limestone Member: Implications for Holocene sea level changes, western India.

  2. Bulletin of Materials Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. M Petrič. Articles written in Bulletin of Materials Science. Volume 34 Issue 1 February 2011 pp 113-119. Performance of waterborne acrylic surface coatings on wood impregnated with Cu-ethanolamine preservatives · M Humar M Pavlič D Žlindra M Tomažič M Petrič.

  3. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. A Shalini. Articles written in Journal of Earth System Science. Volume 115 Issue 4 August 2006 pp 451-460 Special Section on: Material exchanges at marine boundaries and surface ocean processes: Forcings and feedbacks. Spatial and temporal distribution of methane in ...

  4. Proceedings – Mathematical Sciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Proceedings – Mathematical Sciences; Volume 127; Issue 1. Projections of Veronese surface and morphisms from projective plane to Grassmannian ... M2, Universite Lille 1, F-59655 Villeneuve d'Ascq Cedex, France; Institute of Mathematical Sciences, CIT Campus, Taramani, Chennai 600 113, India ...

  5. Journal of Chemical Sciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences. Mikki V Vinodu. Articles written in Journal of Chemical Sciences. Volume 113 Issue 1 February 2001 pp 1-9 Inorganic and Analytical. Peroxidase-like catalytic activities of ionic metalloporphyrins supported on functionalised polystyrene surface · Mikki V Vinodu M ...

  6. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. R Venkatesan. Articles written in Journal of Earth System Science. Volume 127 Issue 1 February 2018 pp 14. Comparison of AMSR-2 wind speed and sea surface temperature with moored buoy observations over the Northern Indian Ocean · B Nanda Kishore Reddy R ...

  7. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. Simi Mathew. Articles written in Journal of Earth System Science. Volume 127 Issue 1 February 2018 pp 14. Comparison of AMSR-2 wind speed and sea surface temperature with moored buoy observations over the Northern Indian Ocean · B Nanda Kishore Reddy R ...

  8. Journal of Chemical Sciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences. I Hubert Joe. Articles written in Journal of Chemical Sciences. Volume 120 Issue 4 July 2008 pp 405-410. Surface enhanced Raman spectra of the organic nonlinear optic material: Methyl 3-(4-methoxy phenyl)prop-2-enoate · D Sajan I Hubert Joe V S Jayakumar Jacek Zaleski.

  9. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. Anup Saha. Articles written in Journal of Earth System Science. Volume 125 Issue 4 June 2016 pp 885-895. Effect of irregularity on torsional surface waves in an initially stressed anisotropic porous layer sandwiched between homogeneous and non-homogeneous half- ...

  10. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. Santimoy Kundu. Articles written in Journal of Earth System Science. Volume 124 Issue 1 February 2015 pp 161-170. Influence of rigid boundary on the propagation of torsional surface wave in an inhomogeneous layer · Shishir Gupta Rehena Sultana Santimoy Kundu.

  11. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. Rehena Sultana. Articles written in Journal of Earth System Science. Volume 124 Issue 1 February 2015 pp 161-170. Influence of rigid boundary on the propagation of torsional surface wave in an inhomogeneous layer · Shishir Gupta Rehena Sultana Santimoy Kundu.

  12. Journal of Chemical Sciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences. KALARICAL JANARDHANAN SREERAM. Articles written in Journal of Chemical Sciences. Volume 126 Issue 1 January 2014 pp 65-73. Effective synthesis route for red-brown pigments based on Ce - Pr - Fe - O and their potential application for near infrared reflective surface ...

  13. Journal of Chemical Sciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences. Yuanming Zhang. Articles written in Journal of Chemical Sciences. Volume 118 Issue 3 May 2006 pp 281-285. Temperature effects on surface activity and application in oxidation of toluene derivatives of CTAB-SDS with KMnO4 · Yu Tang Biying Du Jun Yang Yuanming ...

  14. Bulletin of Materials Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. H Nozoye. Articles written in Bulletin of Materials Science. Volume 24 Issue 6 December 2001 pp 583-586 Thin Films. Preparation of Sm–Ru bimetallic alloy films on Ru(0001) surface by vapour-deposition and annealing · G Ranga Rao H Nozoye · More Details Abstract Fulltext ...

  15. Bulletin of Materials Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. L P Silva. Articles written in Bulletin of Materials Science. Volume 37 Issue 1 February 2014 pp 157-166 Electronic Supplementary Material. Characterization of neutrophil adhesion to different titanium surfaces · V Campos R C N Melo L P Silva E N Aquino M S Castro W Fontes.

  16. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. Sarva Jit Singh. Articles written in Journal of Earth System Science. Volume 111 Issue 4 December 2002 pp 401-412. Reflection of and SV waves at the free surface of a monoclinic elastic half-space · Sarva Jit Singh Sandhya Khurana · More Details Abstract Fulltext PDF.

  17. Journal of Chemical Sciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences. Sundaram Balasubramanian. Articles written in Journal of Chemical Sciences. Volume 127 Issue 10 October 2015 pp 1687-1699. Modelling Gas Adsorption in Porous Solids: Roles of Surface Chemistry and Pore Architecture · Satyanarayana Bonakala Sundaram ...

  18. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. A P Dimri. Articles written in Journal of Earth System Science. Volume 121 Issue 2 April 2012 pp 329-344. Wintertime land surface characteristics in climatic simulations over the western Himalayas · A P Dimri · More Details Abstract Fulltext PDF. Wintertime regional climate ...

  19. Bulletin of Materials Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. R Bajpai. Articles written in Bulletin of Materials Science. Volume 25 Issue 1 February 2002 pp 21-23 Mechanical Properties. Surface modification on PMMA : PVDF polyblend: hardening under chemical environment · R Bajpai V Mishra Pragyesh Agrawal S C Datt · More Details ...

  20. Bulletin of Materials Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. D Žlindra. Articles written in Bulletin of Materials Science. Volume 34 Issue 1 February 2011 pp 113-119. Performance of waterborne acrylic surface coatings on wood impregnated with Cu-ethanolamine preservatives · M Humar M Pavlič D Žlindra M Tomažič M Petrič.

  1. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. P K Kunhikrishnan. Articles written in Journal of Earth System Science. Volume 113 Issue 3 September 2004 pp 353-363. Observations of the atmospheric surface layer parameters over a semi arid region during the solar eclipse of August 11th, 1999 · Praveena Krishnan ...

  2. Bulletin of Materials Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. RIDHA ZOUARI. Articles written in Bulletin of Materials Science. Volume 40 Issue 2 April 2017 pp 289-299. Synthesis, structure and Hirshfeld surface analysis, vibrational and DFT investigation of (4-pyridine carboxylic acid) tetrachlorocuprate (II) monohydrate · KHAOULA ...

  3. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. B N Nath. Articles written in Journal of Earth System Science. Volume 109 Issue 1 March 2000 pp 153-156. Glacial-interglacial changes in the surface water characteristics of the Andaman Sea: Evidence from stable ratios of planktonic foraminifera · S M Ahmad D J Patil P S ...

  4. Associateship | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Period: 1987–1990. Sarma, Dr D D . Date of birth: 15 September 1955. Specialization: Surface Chemistry of Intermetallics Address during Associateship: Solid State and Structural, Chemistry Unit, Indian Institute of Science, Bangalore 560 012.

  5. Fellowship | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Specialization: Solid State Chemistry, Surface Science, Spectroscopy and Molecular Structure Address: Linus Pauling Research Professor, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560 064, Karnataka Contact: Office: (080) 2365 3075, (080) 2208 2761. Residence: (080) 2360 1410

  6. Surface-Enhanced Raman Spectroscopy

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 15; Issue 2. Surface-Enhanced Raman Spectroscopy - Recent Advancement of Raman Spectroscopy. Ujjal Kumar Sur. General Article Volume 15 Issue 2 February 2010 pp 154-164 ...

  7. 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...

  8. Nanomaterials science

    Directory of Open Access Journals (Sweden)

    Heinrich Rohrer

    2010-01-01

    Full Text Available The nanometer regime covers the transition from condensed matter behavior to atomic and molecular properties and thus is a very rich but also very demanding area in materials science. Close to the condensed matter side, properties and functions might still very well be scalable, whereas close to the atomic and molecular side, the scalability is mostly lost. Properties and functions change qualitatively or quantitatively by orders of magnitude when the dimensions become smaller than a critical size in the nanometer range. Examples are the ballistic regime for electron or spin transport at dimensions below the mean free path, near-field effects in scanning near-field optical microscopy and quantum wells when the dimensions are below an appropriate wavelength, novel electronic, mechanical, and chemical properties when the number of bulk atoms becomes smaller than that of surface atoms, quantum conduction, and Coulomb blockade. Thus, by going below a certain size, an abundance of novel properties and functions are at one's disposal, or, in other words, we can functionalize materials simply by reducing their size to the nanoscale.The key to the future lies in the functions that we give to materials, not just in finding 'novel functional materials'. This catch expression in many materials science programs and initiatives of the past two decades sounds great, but it is not what really counts. All materials are functional in one way or another and, therefore, all new materials are 'novel functional materials'. Certainly, finding new materials is always an important part of progress, but we should also focus on the much larger domain of novel functions that we can give to existing or modified materials. A good example is semiconductors: they are fifty or more years old and their properties are very well known, but they were not of widespread interest and use until the transistor changed their destiny into being the central material in the information

  9. Australian synchrotron radiation science

    International Nuclear Information System (INIS)

    White, J.W.

    1996-01-01

    Full text: The Australian Synchrotron Radiation Program, ASRP, has been set up as a major national research facility to provide facilities for scientists and technologists in physics, chemistry, biology and materials science who need access to synchrotron radiation. Australia has a strong tradition in crystallography and structure determination covering small molecule crystallography, biological and protein crystallography, diffraction science and materials science and several strong groups are working in x-ray optics, soft x-ray and vacuum ultra-violet physics. A number of groups whose primary interest is in the structure and dynamics of surfaces, catalysts, polymer and surfactant science and colloid science are hoping to use scattering methods and, if experience in Europe, Japan and USA can be taken as a guide, many of these groups will need third generation synchrotron access. To provide for this growing community, the Australian National Beamline at the Photon Factory, Tsukuba, Japan, has been established since 1990 through a generous collaboration with Japanese colleagues, the beamline equipment being largely produced in Australia. This will be supplemented in 1997 with access to the world's most powerful synchrotron x-ray source at the Advanced Photon Source, Argonne National Laboratory, USA. Some recent experiments in surface science using neutrons as well as x-rays from the Australian National Beamline will be used to illustrate one of the challenges that synchrotron x-rays may meet

  10. FOREWORD Nanomaterials science Nanomaterials science

    Science.gov (United States)

    Rohrer, Heinrich

    2010-10-01

    The nanometer regime covers the transition from condensed matter behavior to atomic and molecular properties and thus is a very rich but also very demanding area in materials science. Close to the condensed matter side, properties and functions might still very well be scalable, whereas close to the atomic and molecular side, the scalability is mostly lost. Properties and functions change qualitatively or quantitatively by orders of magnitude when the dimensions become smaller than a critical size in the nanometer range. Examples are the ballistic regime for electron or spin transport at dimensions below the mean free path, near-field effects in scanning near-field optical microscopy and quantum wells when the dimensions are below an appropriate wavelength, novel electronic, mechanical, and chemical properties when the number of bulk atoms becomes smaller than that of surface atoms, quantum conduction, and Coulomb blockade. Thus, by going below a certain size, an abundance of novel properties and functions are at one's disposal, or, in other words, we can functionalize materials simply by reducing their size to the nanoscale. The key to the future lies in the functions that we give to materials, not just in finding 'novel functional materials'. This catch expression in many materials science programs and initiatives of the past two decades sounds great, but it is not what really counts. All materials are functional in one way or another and, therefore, all new materials are 'novel functional materials'. Certainly, finding new materials is always an important part of progress, but we should also focus on the much larger domain of novel functions that we can give to existing or modified materials. A good example is semiconductors: they are fifty or more years old and their properties are very well known, but they were not of widespread interest and use until the transistor changed their destiny into being the central material in the information technology revolution

  11. Physics of Surfaces and Interfaces

    CERN Document Server

    Ibach, Harald

    2006-01-01

    This graduate-level textbook covers the major developments in surface sciences of recent decades, from experimental tricks and basic techniques to the latest experimental methods and theoretical understanding. It is unique in its attempt to treat the physics of surfaces, thin films and interfaces, surface chemistry, thermodynamics, statistical physics and the physics of the solid/electrolyte interface in an integral manner, rather than in separate compartments. The Physics of Surfaces and Interfaces is designed as a handbook for the researcher as well as a study-text for graduate students in physics or chemistry with special interest in the surface sciences, material science, or the nanosciences. The experienced researcher, professional or academic teacher will appreciate the opportunity to share many insights and ideas that have grown out of the author's long experience. Readers will likewise appreciate the wide range of topics treated, each supported by extensive references. Graduate students will benefit f...

  12. Helium atom scattering from surfaces

    CERN Document Server

    1992-01-01

    High resolution helium atom scattering can be applied to study a number of interesting properties of solid surfaces with great sensitivity and accuracy. This book treats in detail experimental and theoretical aspects ofthis method as well as all current applications in surface science. The individual chapters - all written by experts in the field - are devoted to the investigation of surface structure, defect shapes and concentrations, the interaction potential, collective and localized surface vibrations at low energies, phase transitions and surface diffusion. Over the past decade helium atom scattering has gained widespread recognitionwithin the surface science community. Points in its favour are comprehensiveunderstanding of the scattering theory and the availability of well-tested approximation to the rigorous theory. This book will be invaluable to surface scientists wishing to make an informed judgement on the actual and potential capabilities of this technique and its results.

  13. Sound Science

    Science.gov (United States)

    Sickel, Aaron J.; Lee, Michele H.; Pareja, Enrique M.

    2010-01-01

    How can a teacher simultaneously teach science concepts through inquiry while helping students learn about the nature of science? After pondering this question in their own teaching, the authors developed a 5E learning cycle lesson (Bybee et al. 2006) that concurrently embeds opportunities for fourth-grade students to (a) learn a science concept,…

  14. Surface enhanced Raman scattering

    CERN Document Server

    Furtak, Thomas

    1982-01-01

    In the course of the development of surface science, advances have been identified with the introduction of new diagnostic probes for analytical characterization of the adsorbates and microscopic structure of surfaces and interfaces. Among the most recently de­ veloped techniques, and one around which a storm of controversy has developed, is what has now been earmarked as surface enhanced Raman scattering (SERS). Within this phenomenon, molecules adsorbed onto metal surfaces under certain conditions exhibit an anomalously large interaction cross section for the Raman effect. This makes it possible to observe the detailed vibrational signature of the adsorbate in the ambient phase with an energy resolution much higher than that which is presently available in electron energy loss spectroscopy and when the surface is in contact with a much larger amount of material than that which can be tolerated in infrared absorption experiments. The ability to perform vibrational spectroscopy under these conditions would l...

  15. Surface Science at the Solid Liquid Interface

    Science.gov (United States)

    1993-10-06

    18 1002 T. iR Dillingham X-Ray Photoelectron Spectroscopy Analysis of Borate Substituted Polyaniline Thin Films 19 1050 Karl Robinson In-Situ X-Ray...Monreal, and P. Apell , Phys. Rev. B 42. 9210 (1990) processes. It is known the probability becomes higher as 20D. L. Mills, M. Weber, and B. Laks, in...in UHV and solu- 22B. Reihl, K. H. Frank, and A. Otto , Z. Phys. B 62. 473 (1986). tion, when the Ag electrode is held at the PZC. We are 23S. D

  16. Versatile Density Functionals for Computational Surface Science

    DEFF Research Database (Denmark)

    Wellendorff, Jess

    resampling techniques, thereby systematically avoiding problems with overfitting. The first ever density functional presenting both reliable accuracy and convincing error estimation is generated. The methodology is general enough to be applied to more complex functional forms with higher-dimensional fitting...... and resampling. This is illustrated by searching for meta-GGA type functionals that outperform current meta-GGAs while allowing for error estimation....

  17. Legalising science.

    Science.gov (United States)

    Tallacchini, Mariachiara

    2002-01-01

    The legal view of science has changed through time, moving from a positivist and noncritical position of law towards science to a critical view of science--providing the potential for more objective knowledge, but value-laden as well--and of the role of society. This paper explores some judicial cases that illustrate these attitudes, suggesting that reference to science (particularly to EBM) can be rigorously and equitably made when it serves the cause of transparency and democratisation both in science and in law.

  18. Science Teaching in Science Education

    Science.gov (United States)

    Callahan, Brendan E.; Dopico, Eduardo

    2016-01-01

    Reading the interesting article "Discerning selective traditions in science education" by Per Sund, which is published in this issue of "CSSE," allows us to open the discussion on procedures for teaching science today. Clearly there is overlap between the teaching of science and other areas of knowledge. However, we must…

  19. Materials Sciences Division 1990 annual report

    Energy Technology Data Exchange (ETDEWEB)

    1990-12-31

    This report is the Materials Sciences Division`s annual report. It contains abstracts describing materials research at the National Center for Electron Microscopy, and for research groups in metallurgy, solid-state physics, materials chemistry, electrochemical energy storage, electronic materials, surface science and catalysis, ceramic science, high tc superconductivity, polymers, composites, and high performance metals.

  20. Materials Sciences Division 1990 annual report

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    This report is the Materials Sciences Division's annual report. It contains abstracts describing materials research at the National Center for Electron Microscopy, and for research groups in metallurgy, solid-state physics, materials chemistry, electrochemical energy storage, electronic materials, surface science and catalysis, ceramic science, high tc superconductivity, polymers, composites, and high performance metals.

  1. Materials Sciences Division 1990 annual report

    International Nuclear Information System (INIS)

    1990-01-01

    This report is the Materials Sciences Division's annual report. It contains abstracts describing materials research at the National Center for Electron Microscopy, and for research groups in metallurgy, solid-state physics, materials chemistry, electrochemical energy storage, electronic materials, surface science and catalysis, ceramic science, high tc superconductivity, polymers, composites, and high performance metals

  2. Plasma Science Committee (PLSC)

    International Nuclear Information System (INIS)

    1990-01-01

    The Plasma Science Committee (PLSC) is a standing committee under the auspices of the Board on Physics and Astronomy, Commission on Physical Sciences, Mathematics, and Applications of the National Academy of Sciences--National Research Council. Plasma sciences represent a broad and diverse field. The PLSC has accepted the responsibility of monitoring the continuing development and assessing the general health of the field as whole. Although select advisory bodies have been created to address specific issues that affect plasma science, such as the Fusion Policy Advisory Committee (FPAC), the PLSC provides a focus for the plasma science community that is unique and essential. The membership of the PLSC is drawn from research laboratories in universities, industry, and government. Areas of expertise on the committee include accelerators and beams, space physics, astrophysics, computational physics and applied mathematics, fusion plasmas, fundamental experiments and theory, radiation sources, low temperature plasmas, and plasma-surface interactions. The PLSC is well prepared to respond to requests for studies on specific issues. This report discusses ion of the PLSC work

  3. Science Shops

    DEFF Research Database (Denmark)

    Jørgensen, Michael Søgaard

    1999-01-01

    The paper prsents the overall concept of science shops as practised in most of the European science shops and present the concept practised and some experience obtained at the Technical University of Denmark. An outline for the planning of new sceince shops is presented.......The paper prsents the overall concept of science shops as practised in most of the European science shops and present the concept practised and some experience obtained at the Technical University of Denmark. An outline for the planning of new sceince shops is presented....

  4. Science Fairs for Science Literacy

    Science.gov (United States)

    Mackey, K. R.

    2014-12-01

    Science literacy is imperative for well informed civic and personal decision making, yet only a quarter of American adults are proficient enough in science to understand science stories reported in the popular press. Hands-on research increases confidence in and understanding of science. When guiding students in designing and conducting science fair projects, mentors can foster science literacy by helping students focus on three goals: (1) articulating hypotheses or questions, (2) designing feasible projects, and (3) learning to make and interpret graphs. These objectives introduce students to the methodological nature of scientific research and give them the tools to interpret scientific facts and data in order to make informed decisions for themselves and society.

  5. The science in social science.

    Science.gov (United States)

    Bernard, H Russell

    2012-12-18

    A recent poll showed that most people think of science as technology and engineering--life-saving drugs, computers, space exploration, and so on. This was, in fact, the promise of the founders of modern science in the 17th century. It is less commonly understood that social and behavioral sciences have also produced technologies and engineering that dominate our everyday lives. These include polling, marketing, management, insurance, and public health programs.

  6. The sciences of science communication.

    Science.gov (United States)

    Fischhoff, Baruch

    2013-08-20

    The May 2012 Sackler Colloquium on "The Science of Science Communication" brought together scientists with research to communicate and scientists whose research could facilitate that communication. The latter include decision scientists who can identify the scientific results that an audience needs to know, from among all of the scientific results that it would be nice to know; behavioral scientists who can design ways to convey those results and then evaluate the success of those attempts; and social scientists who can create the channels needed for trustworthy communications. This overview offers an introduction to these communication sciences and their roles in science-based communication programs.

  7. Integrated Science.

    Science.gov (United States)

    Rainey, Larry; Miller, Roxanne Greitz

    1997-01-01

    Describes the Integrated Science program that integrates biology, earth/space science, chemistry, and physics over a three-year, spiraling sequence arranged around broad themes such as cycles, changes, patterns, and waves. Includes weekly telecasts via public television and satellite, teacher manuals, student handbooks, e-mail connections, staff…

  8. Using Science

    Science.gov (United States)

    Kelly, Deryk

    1971-01-01

    Article discusses educational benefits of science hobbies, citing specific accomplishments of British students. New courses in Engineering Science and recent development of scientific investigation and technological classroom projects are noted. Author relates how students have solved specific practical problems, such as devising games to develop…

  9. Life sciences

    International Nuclear Information System (INIS)

    Day, L.

    1991-04-01

    This document is the 1989--1990 Annual Report for the Life Sciences Divisions of the University of California/Lawrence Berkeley Laboratory. Specific progress reports are included for the Cell and Molecular Biology Division, the Research Medicine and Radiation Biophysics Division (including the Advanced Light Source Life Sciences Center), and the Chemical Biodynamics Division. 450 refs., 46 figs

  10. Life sciences

    Energy Technology Data Exchange (ETDEWEB)

    Day, L. (ed.)

    1991-04-01

    This document is the 1989--1990 Annual Report for the Life Sciences Divisions of the University of California/Lawrence Berkeley Laboratory. Specific progress reports are included for the Cell and Molecular Biology Division, the Research Medicine and Radiation Biophysics Division (including the Advanced Light Source Life Sciences Center), and the Chemical Biodynamics Division. 450 refs., 46 figs. (MHB)

  11. Science Matters

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 2. Science Matters A Book for Curious Minds. Rohini Godbole. Book Review Volume 2 Issue 2 February 1997 pp 94-95. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/002/02/0094-0095 ...

  12. Time-variable surface patterns as an indicator of the surface environments on Mars

    Science.gov (United States)

    Toyota, T.; Kawaguchi, K.; Kurita, K.

    2008-09-01

    Introduction On the planets having atmosphere such as Mars various types of interactions between the atmosphere and the ground surface cause observable change in the surface pattern. Polar caps and aeolian features are typical examples. With the accumulation of satellitebased exploratory data, time-variable surface patterns have been focused and investigated extensively [1,2], because they can be direct indicators of the changing surface environments. Here we report two types of time-variable surface patterns that have been unidentified until now. One is dark halo near the top of high altitude volcanoes in Tharsis region. The other is brightness of the Outer Lobe of Double Layered Ejecta crater at the northern lowlands. Both have almost no associated topography and they are only recognized in visible/IR images as albedo patterns. Dark halo near the top of high altitude volcanoes in the Tharsis region Fig. 1 shows MOC wide-angle image of Pavonis Mons (R1400388NRed). The large caldera can be seen at the top of the volcano. Surrounding the caldera there exists a dark halo. Fig. 1B is MOC wide-angle image which shows detailed structure of the dark halo in the SW part. The dark zone is not uniform and instead it is composed of many slender dark stripes aligned in radial direction from the top (caldera center). Each unit is spindle-shaped with length of 30- 50km and width at the middle part of 5km. Spindles seem to start from higher position because it is always clear and darker. The initiation point is quite narrow region, which can be considered as a point. In many cases, there exist no recognisable obstacles at the initiation point. This is a remarkable difference from the wind streaks, which is caused by erosion/sedimentation of wind by local turbulence behind topographical anomaly. This makes us to consider something is emanating from subsurface, blown off by the mountain winds and deposited in downwind part. Similar pattern is observed in high altitude large volume

  13. I'm White and You're Not: The Value of Unraveling Ethnocentric Science.

    Science.gov (United States)

    Jones, James M

    2010-11-01

    Whether motivated by racist intent, ethnocentric arrogance, or data analytic myopia, research that systematically stigmatizes specific human groups is destructive. The racist assumptions of the inferiority of African culture and persons of African descent have contributed substantially to stigmatizing beliefs about African Americans. This article presents historical examples of several kinds of motivated or myopic theoretical and empirical projects that stigmatize African Americans and examples of how an examination of culture and social context may alleviate these problems. A discussion of ways to diversify psychological science includes diversifying those who do it, broadening the cultural perspectives and problems from which psychological concepts emanate (particularly in the United States), and formalizing diversity science as a system of theoretical and empirical research. © The Author(s) 2010.

  14. Minimal surfaces

    CERN Document Server

    Dierkes, Ulrich; Sauvigny, Friedrich; Jakob, Ruben; Kuster, Albrecht

    2010-01-01

    Minimal Surfaces is the first volume of a three volume treatise on minimal surfaces (Grundlehren Nr. 339-341). Each volume can be read and studied independently of the others. The central theme is boundary value problems for minimal surfaces. The treatise is a substantially revised and extended version of the monograph Minimal Surfaces I, II (Grundlehren Nr. 295 & 296). The first volume begins with an exposition of basic ideas of the theory of surfaces in three-dimensional Euclidean space, followed by an introduction of minimal surfaces as stationary points of area, or equivalently

  15. Rumble surfaces

    CSIR Research Space (South Africa)

    National Institute for Transport and Road

    1977-01-01

    Full Text Available Rumble surfaces are intermittent short lengths of coarse-textured road surfacings on which vehicle tyres produce a rumbling sound. used in conjunction with appropriate roadsigns and markings, they can reduce accidents on rural roads by alerting...

  16. Surface thermodynamics

    International Nuclear Information System (INIS)

    Garcia-Moliner, F.

    1975-01-01

    Basic thermodynamics of a system consisting of two bulk phases with an interface. Solid surfaces: general. Discussion of experimental data on surface tension and related concepts. Adsorption thermodynamics in the Gibbsian scheme. Adsorption on inert solid adsorbents. Systems with electrical charges: chemistry and thermodynamics of imperfect crystals. Thermodynamics of charged surfaces. Simple models of charge transfer chemisorption. Adsorption heat and related concepts. Surface phase transitions

  17. Revolutionary Science

    Directory of Open Access Journals (Sweden)

    Arturo Casadevall

    2016-05-01

    Full Text Available On rare occasions in the history of science, remarkable discoveries transform human society and forever alter mankind’s view of the world. Examples of such discoveries include the heliocentric theory, Newtonian physics, the germ theory of disease, quantum theory, plate tectonics and the discovery that DNA carries genetic information. The science philosopher Thomas Kuhn famously described science as long periods of normality punctuated by times of crisis, when anomalous observations culminate in revolutionary changes that replace one paradigm with another. This essay examines several transformative discoveries in the light of Kuhn’s formulation. We find that each scientific revolution is unique, with disparate origins that may include puzzle solving, serendipity, inspiration, or a convergence of disparate observations. The causes of revolutionary science are varied and lack an obvious common structure. Moreover, it can be difficult to draw a clear distinction between so-called normal and revolutionary science. Revolutionary discoveries often emerge from basic science and are critically dependent on nonrevolutionary research. Revolutionary discoveries may be conceptual or technological in nature, lead to the creation of new fields, and have a lasting impact on many fields in addition to the field from which they emerge. In contrast to political revolutions, scientific revolutions do not necessarily require the destruction of the previous order. For humanity to continue to benefit from revolutionary discoveries, a broad palette of scientific inquiry with a particular emphasis on basic science should be supported.

  18. Revolutionary Science.

    Science.gov (United States)

    Casadevall, Arturo; Fang, Ferric C

    2016-03-01

    On rare occasions in the history of science, remarkable discoveries transform human society and forever alter mankind's view of the world. Examples of such discoveries include the heliocentric theory, Newtonian physics, the germ theory of disease, quantum theory, plate tectonics and the discovery that DNA carries genetic information. The science philosopher Thomas Kuhn famously described science as long periods of normality punctuated by times of crisis, when anomalous observations culminate in revolutionary changes that replace one paradigm with another. This essay examines several transformative discoveries in the light of Kuhn's formulation. We find that each scientific revolution is unique, with disparate origins that may include puzzle solving, serendipity, inspiration, or a convergence of disparate observations. The causes of revolutionary science are varied and lack an obvious common structure. Moreover, it can be difficult to draw a clear distinction between so-called normal and revolutionary science. Revolutionary discoveries often emerge from basic science and are critically dependent on nonrevolutionary research. Revolutionary discoveries may be conceptual or technological in nature, lead to the creation of new fields, and have a lasting impact on many fields in addition to the field from which they emerge. In contrast to political revolutions, scientific revolutions do not necessarily require the destruction of the previous order. For humanity to continue to benefit from revolutionary discoveries, a broad palette of scientific inquiry with a particular emphasis on basic science should be supported. Copyright © 2016 Casadevall and Fang.

  19. Dynamics at Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Sylvia Ceyer, Nancy Ryan Gray

    2010-05-04

    The 2009 Gordon Conference on Dynamics at Surfaces is the 30th anniversary of a meeting held every two years that is attended by leading researchers in the area of experimental and theoretical dynamics at liquid and solid surfaces. The conference focuses on the dynamics of the interaction of molecules with either liquid or solid surfaces, the dynamics of the outermost layer of liquid and solid surfaces and the dynamics at the liquid-solid interface. Specific topics that are featured include state-to-state dynamics, non-adiabatic interactions in molecule-metal systems, photon induced desorption from semiconductor and metal surfaces, ultrafast x-ray and electron diffraction as probes of the dynamics of ablation, ultrafast vibrational spectroscopy of water surface dynamics, dynamics of a single adsorbate, growth at nano-scale mineral surfaces, dynamics of atom recombination on interstellar dust grains and the dynamics of the interaction of water with lipid bilayers. The conference brings together investigators from a variety of scientific disciplines including chemistry, physics, materials science, geology and biophysics.

  20. Science Instructors' Views of Science and Nature of Science

    Science.gov (United States)

    Karakas, Mehmet

    2011-01-01

    This qualitative study examined how college science faculty who teach introductory level undergraduate science courses including the fields of chemistry, biology, physics, and earth science, understand and define science and nature of science (NOS). Participants were seventeen science instructors from five different institutions in the…

  1. Science, human nature, and a new paradigm for ethics education.

    Science.gov (United States)

    Lampe, Marc

    2012-09-01

    For centuries, religion and philosophy have been the primary basis for efforts to guide humans to be more ethical. However, training in ethics and religion and imparting positive values and morality tests such as those emanating from the categorical imperative and the Golden Rule have not been enough to protect humankind from its bad behaviors. To improve ethics education educators must better understand aspects of human nature such as those that lead to "self-deception" and "personal bias." Through rationalizations, faulty reasoning and hidden bias, individuals trick themselves into believing there is little wrong with their own unethical behavior. The application of science to human nature offers the possibility of improving ethics education through better self-knowledge. The author recommends a new paradigm for ethics education in contemporary modern society. This includes the creation of a new field called "applied evolutionary neuro-ethics" which integrates science and social sciences to improve ethics education. The paradigm can merge traditional thinking about ethics from religious and philosophical perspectives with new ideas from applied evolutionary neuro-ethics.

  2. Environmental sciences

    NARCIS (Netherlands)

    Kwa, C.; Wright, J.D.

    2015-01-01

    The environmental sciences are engaged in a remarkable effort of interdisciplinary cooperation and integration. Some long-running international scientific programs, notably the World Climate Research Programme and the International Geosphere-Biosphere Programme, play an important role therein. The

  3. Big science

    CERN Multimedia

    Nadis, S

    2003-01-01

    " "Big science" is moving into astronomy, bringing large experimental teams, multi-year research projects, and big budgets. If this is the wave of the future, why are some astronomers bucking the trend?" (2 pages).

  4. Forensic Science.

    Science.gov (United States)

    Brettell, T. A.; Saferstein, R.

    1989-01-01

    Presents a review of articles appealing to forensic practitioners. Topics include: drugs and poisons, forensic biochemistry, and trace evidence. Lists noteworthy books published on forensic science topics since 1986. (MVL)

  5. Science Smiles

    Indian Academy of Sciences (India)

    IAS Admin

    Page 1. 582. RESONANCE | July 2016. Science Smiles. Ayan Guha. “Ribbed breathing flesh, thrice often crucified,. Veined vase of life, the wheeling universe.” – Sir Charles Sherrington. Email for Correspondence: ionguha@gmail.com.

  6. Science Smiles

    Indian Academy of Sciences (India)

    Page 1. 408. RESONANCE │ May 2011. GENERAL │ ARTICLE. Email for Correspondence: ionguha@gmail.com. Science Smiles. Ayan Guha. It feels like I am posing with the Bourbaki group, where every member is a Zeldovich.

  7. Science Smiles

    Indian Academy of Sciences (India)

    IAS Admin

    Page 1. 1084. RESONANCE | December 2015. Science Smiles. Ayan Guha. Charles H Townes, James P Gordon and H J. Zeiger had the first Maser working about three months later.. Email for Correspondence: ionguha@gmail.com.

  8. Citizen Science

    Science.gov (United States)

    Citizen Science is a fast-growing field in which scientific investigations are conducted by volunteers, which have been successful in expanding scientific knowledge, raising environmental awareness, and leveraging change.

  9. Dismal science.

    Science.gov (United States)

    Evans, Robert G

    2009-05-01

    "No prediction, no science." By this standard, the past year has not been kind to the pretensions of "economic science," Nobel prizes notwithstanding. The issue is more than semantic. As Neil Postman (1992) pointed out, sciences study natural processes that repeat themselves under constant conditions. The social disciplines study practices of human communities that are embedded in history. There are no constant conditions; it is impossible to step into the same river twice (Heraclitus). "Physics envy" has led mainstream economic theorists to attempt to understand their discipline through methods and models borrowed from the natural sciences. (By unfortunate coincidence, these have reinforced a certain class of ideological preconceptions and associated economic interests.) Today the results of this methodological mismatch speak for themselves.

  10. Science Bubbles

    DEFF Research Database (Denmark)

    Hendricks, Vincent Fella; Pedersen, David Budtz

    2013-01-01

    Much like the trade and trait sof bubbles in financial markets,similar bubbles appear on the science market. When economic bubbles burst, the drop in prices causes the crash of unsustainable investments leading to an investor confidence crisis possibly followed by a financial panic. But when bubb...... bubbles appear in science, truth and reliability are the first victims. This paper explores how fashions in research funding and research management may turn science into something like a bubble economy.......Much like the trade and trait sof bubbles in financial markets,similar bubbles appear on the science market. When economic bubbles burst, the drop in prices causes the crash of unsustainable investments leading to an investor confidence crisis possibly followed by a financial panic. But when...

  11. Science Topics

    Science.gov (United States)

    EPA is one of the world’s leading environmental and human health research organizations. Science provides the foundation for Agency policies, actions, and decisions made on behalf of the American people.

  12. Molecular sciences

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    The research in molecular sciences summarized includes photochemistry, radiation chemistry, geophysics, electromechanics, heavy-element oxidizers , heavy element chemistry collisions, atoms, organic solids. A list of publications is included

  13. Earth Sciences

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    The following papers were presented at the earth science session: earth science developments in support of water isolation; development of models and parameters for ground-water flow in fractured rock masses; isotope geochemistry as a tool for determining regional ground-water flow; natural analogs of radionuclide migration; nuclide retardation data: its use in the NWTS program; and ground-water geochemistry and interaction with basalt at Hanford

  14. World science

    International Nuclear Information System (INIS)

    Anon.

    1989-01-01

    The aim of the Third World Network of Scientific Organizations (TWNSO), established last year with its headquarters in Trieste, Italy, is to promote the role of science and technology in developing countries. TWNSO, under the presidency of Abdus Salam, is an offshoot of the Third World Academy of Sciences, which has pushed the cause of international scientific collaboration since its establishment in 1983. (orig./HSI).

  15. Sadhana | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Industrial Computed Tomographic (ICT) imaging systems based on X-rays require a high stability source. This emanates from the fact that in a computed tomographic imaging system, statistical variation inherent in the penetrating radiation used to probe the specimen, electronic noise generated in the detection system and ...

  16. African Journal of Health Sciences

    African Journals Online (AJOL)

    The Publications Committee, a committee comprised of the senior scientists that peruses all publications emanating from KEMRI, felt that it was essential to continue with the publication and circulation of the Journal as soon as possible. Therefore the Publications Committee formed a new team to revive the publication and ...

  17. Chemistry and Materials Science progress report, FY 1994. Revision 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-01-01

    Thrust areas of the weapons-supporting research include surface science, fundamentals of the physics and processing of metals, energetic materials, etc. The laboratory directed R and D include director`s initiatives, individual projects, and transactinium science studies.

  18. Vacuum science, technology, and applications

    CERN Document Server

    Naik, Pramod K

    2018-01-01

    Vacuum plays an important role in science and technology. The study of interaction of charged particles, neutrals and radiation with each other and with solid surfaces requires a vacuum environment for reliable investigations. Vacuum has contributed immensely to advancements made in nuclear science, space, metallurgy, electrical/electronic technology, chemical engineering, transportation, robotics and many other fields. This book is intended to assist students, scientists, technicians and engineers to understand the basics of vacuum science and technology for application in their projects. The fundamental theories, concepts, devices, applications, and key inventions are discussed.

  19. JPRS Report Science & Technology USSR: Life Sciences

    National Research Council Canada - National Science Library

    1988-01-01

    ...: Life sciences, aerospace medicine, agriculture science, biochemistry, biophysics, genetics, immunology, industrial medicine, laser bioeffects, medicine, molecular biology, nonionizing radiation...

  20. PREFACE: Vibrations at surfaces Vibrations at surfaces

    Science.gov (United States)

    Rahman, Talat S.

    2011-12-01

    This special issue is dedicated to the phenomenon of vibrations at surfaces—a topic that was indispensible a couple of decades ago, since it was one of the few phenomena capable of revealing the nature of binding at solid surfaces. For clean surfaces, the frequencies of modes with characteristic displacement patterns revealed how surface geometry, as well as the nature of binding between atoms in the surface layers, could be different from that in the bulk solid. Dispersion of the surface phonons provided further measures of interatomic interactions. For chemisorbed molecules on surfaces, frequencies and dispersion of the vibrational modes were also critical for determining adsorption sites. In other words, vibrations at surfaces served as a reliable means of extracting information about surface structure, chemisorption and overlayer formation. Experimental techniques, such as electron energy loss spectroscopy and helium-atom-surface scattering, coupled with infra-red spectroscopy, were continually refined and their resolutions enhanced to capture subtleties in the dynamics of atoms and molecules at surfaces. Theoretical methods, whether based on empirical and semi-empirical interatomic potential or on ab initio electronic structure calculations, helped decipher experimental observations and provide deeper insights into the nature of the bond between atoms and molecules in regions of reduced symmetry, as encountered on solid surfaces. Vibrations at surfaces were thus an integral part of the set of phenomena that characterized surface science. Dedicated workshops and conferences were held to explore the variety of interesting and puzzling features revealed in experimental and theoretical investigations of surface vibrational modes and their dispersion. One such conference, Vibrations at Surfaces, first organized by Harald Ibach in Juelich in 1980, continues to this day. The 13th International Conference on Vibrations at Surfaces was held at the University of

  1. Science Fairs for Science Literacy

    Science.gov (United States)

    Mackey, Katherine; Culbertson, Timothy

    2014-03-01

    Scientific discovery, technological revolutions, and complex global challenges are commonplace in the modern era. People are bombarded with news about climate change, pandemics, and genetically modified organisms, and scientific literacy has never been more important than in the present day. Yet only 29% of American adults have sufficient understanding to be able to read science stories reported in the popular press [Miller, 2010], and American students consistently rank below other nations in math and science [National Center for Education Statistics, 2012].

  2. Exploring science through science fiction

    CERN Document Server

    Luokkala, Barry B

    2014-01-01

    How does Einstein’s description of space and time compare with Dr. Who? Can James Bond really escape from an armor-plated railroad car by cutting through the floor with a laser concealed in a wristwatch? What would it take to create a fully-intelligent android, such as Star Trek’s Commander Data? How might we discover intelligent civilizations on other planets in the galaxy? Is human teleportation possible? Will our technological society ever reach the point at which it becomes lawful to discriminate on the basis of genetic information, as in the movie GATTACA? Exploring Science Through Science Fiction addresses these and other interesting questions, using science fiction as a springboard for discussing fundamental science concepts and cutting-edge science research. The book is designed as a primary text for a college-level course which should appeal to students in the fine arts and humanities as well as to science and engineering students. It includes references to original research papers, landmark scie...

  3. Mechanical surface analysis of bone: a case study of cut marks and enamel hypoplasia on a Neolithic cranium from Sweden.

    Science.gov (United States)

    During, E M; Nilsson, L

    1991-02-01

    A method for measuring, recording, and studying fine surface irregularities in three dimensions is presented. The method, which involves recording the movements of a diamond-tipped stylus as it scans the surface being studied, is demonstrated on a Neolithic cranium from Sweden. The cranium emanates from a pile dwelling dated to about 3000 B.C. Its frontal bone exhibits distinct cut marks indicative of scalping, and the teeth show signs of enamel hypoplasia. The surface topography of the putative cut marks and hypoplastic enamel were investigated using the stylus method. Measurements of enamel hypoplasia were also carried out for comparison on a front tooth from the lower jaw, and the cut mark study was compared with scanning electron micrographs. The results of this case study demonstrate that the stylus method can obtain high-resolution measurements of fine surface details directly on the original bone without preparation of or damage to the specimen.

  4. Science Fiction on Film.

    Science.gov (United States)

    Burmester, David

    1985-01-01

    Reviews science fiction films used in a science fiction class. Discusses feature films, short science fiction films, short story adaptations, original science fiction pieces and factual science films that enrich literature. (EL)

  5. Surface mobilities on solid materials

    International Nuclear Information System (INIS)

    Binh, V.T.

    1983-01-01

    This book constitutes the proceedings of the NATO Advanced Study Institute on Surface Mobilities on Solid Materials held in France in 1981. The goal of the two-week meeting was to review up-to-date knowledge on surface diffusion, both theoretical and experimental, and to highlight those areas in which much more knowledge needs to be accumulated. Topics include theoretical aspects of surface diffusion (e.g., microscopic theories of D at zero coverage; statistical mechanical models and surface diffusion); surface diffusion at the atomic level (e.g., FIM studies of surface migration of single adatoms and diatomic clusters; field emission studies of surface diffusion of adsorbates); foreign adsorbate mass transport; self-diffusion mass transport (e.g., different driving forces for the matter transport along surfaces; measurements of the morphological evolution of tips); the role of surface diffusion in some fundamental and applied sciences (e.g. adatomadatom pair interactions and adlayer superstructure formation; surface mobility in chemical reactions and catalysis); and recent works on surface diffusion (e.g., preliminary results on surface self-diffusion measurements on nickel and chromium tips)

  6. Network science

    CERN Document Server

    Barabasi, Albert-Laszlo

    2016-01-01

    Networks are everywhere, from the Internet, to social networks, and the genetic networks that determine our biological existence. Illustrated throughout in full colour, this pioneering textbook, spanning a wide range of topics from physics to computer science, engineering, economics and the social sciences, introduces network science to an interdisciplinary audience. From the origins of the six degrees of separation to explaining why networks are robust to random failures, the author explores how viruses like Ebola and H1N1 spread, and why it is that our friends have more friends than we do. Using numerous real-world examples, this innovatively designed text includes clear delineation between undergraduate and graduate level material. The mathematical formulas and derivations are included within Advanced Topics sections, enabling use at a range of levels. Extensive online resources, including films and software for network analysis, make this a multifaceted companion for anyone with an interest in network sci...

  7. Absorption of solar energy heats up our planet's surface and the atmosphere and makes life for us po

    Science.gov (United States)

    2002-01-01

    Credit: Image courtesy Barbara Summey, NASA Goddard Visualization Analysis Lab, based upon data processed by Takmeng Wong, CERES Science Team, NASA Langley Research Center Satellite: Terra Sensor: CERES Image Date: 09-30-2001 VE Record ID: 11546 Description: Absorption of solar energy heats up our planet's surface and the atmosphere and makes life for us possible. But the energy cannot stay bound up in the Earth's environment forever. If it did then the Earth would be as hot as the Sun. Instead, as the surface and the atmosphere warm, they emit thermal longwave radiation, some of which escapes into space and allows the Earth to cool. This false-color image of the Earth was produced on September 30, 2001, by the Clouds and the Earth's Radiant Energy System (CERES) instrument flying aboard NASA's Terra spacecraft. The image shows where more or less heat, in the form of longwave radiation, is emanating from the top of Earth's atmosphere. As one can see in the image, the thermal radiation leaving the oceans is fairly uniform. The blue swaths across the central Pacific represent thick clouds, the tops of which are so high they are among the coldest places on Earth. In the American Southwest, which can be seen in the upper righthand corner of the globe, there is often little cloud cover to block outgoing radiation and relatively little water to absorb solar energy. Consequently, the amount of outgoing radiation in the American Southwest exceeds that of the oceans. Also, that region was experiencing an extreme heatwave when these data were acquired. Recently, NASA researchers discovered that incoming solar radiation and outgoing thermal radiation increased in the tropics from the 1980s to the 1990s. (Click to read the press release .) They believe that the reason for the unexpected increase has to do with an apparent change in circulation patterns around the globe, which effectively reduced the amount of water vapor and cloud cover in the upper reaches of the atmosphere

  8. Projects submitted to international science and technology center by Institute of Combustion Problems. Production of powder magnet materials on the basis of natural oxide minerals for purification of the water surface from oil and petrol pollution

    International Nuclear Information System (INIS)

    Mofa, N.; Ksandopoulo, G.

    1996-01-01

    Goal: To obtain a cheap magnet sorbent with high sorbing activity to move off oil and petrol pollution from the surface of water and to purify pools and sewage waters. Task: By mechanical and chemical treatment of natural oxide compounds with a member of selected components there is synthesized a fine-dispersed powder material with micro composition structure of the particles (dielectric nucleus, conductive and magnet surface layers). Formation of surface layers is determined by the regime of mechanical and chemical treatment and alloying additives of the mixture, Properties of the treated powder depend finally on the structure and properties of synthesized surface layers organically connected between themselves and a nuclear carrier of a particle. Due to the characteristics of magnet permeability obtained oxide material is not worse than metallic powders of iron and its alloys. Besides, it has a high corrosion stability and stability of magnet properties in the humid environment and at heating up to 600 C. High sorbing activity provides absolute purification of water surface from oils at small residence times with polluted surface. Peculiarities of state of the particles surface of synthesized material provide structural stability of sorbed mass which enables moving it off from the water surface by mechanic or magnet techniques. By the method being used and feedstock synthesized magnet powder is very cheap and can be used after regeneration directly or as a construction material

  9. Cartographic science: a compendium of map projections, with derivations

    National Research Council Canada - National Science Library

    Fenna, Donald

    2007-01-01

    "From basic projecting to advanced transformations, Cartographic Science: A Compendium of Map Projections, with Derivations comprehensively explores the depiction of a curved world on a flat surface...

  10. Superhydrophobic surfaces

    Science.gov (United States)

    Wang, Evelyn N; McCarthy, Matthew; Enright, Ryan; Culver, James N; Gerasopoulos, Konstantinos; Ghodssi, Reza

    2015-03-24

    Surfaces having a hierarchical structure--having features of both microscale and nanoscale dimensions--can exhibit superhydrophobic properties and advantageous condensation and heat transfer properties. The hierarchical surfaces can be fabricated using biological nanostructures, such as viruses as a self-assembled nanoscale template.

  11. Spherical Surfaces

    DEFF Research Database (Denmark)

    Brander, David

    2016-01-01

    We study surfaces of constant positive Gauss curvature in Euclidean 3-space via the harmonicity of the Gauss map. Using the loop group representation, we solve the regular and the singular geometric Cauchy problems for these surfaces, and use these solutions to compute several new examples. We give...

  12. Lunar Science Conference, 8th, Houston, Tex., March 14-18, 1977, Proceedings. Volume 1 - The moon and the inner solar system. Volume 2 - Petrogenetic studies of mare and highland rocks. Volume 3 - Planetary and lunar surfaces

    Science.gov (United States)

    Merril, R. B.

    1977-01-01

    Solar system processes are considered along with the origin and evolution of the moon, planetary geophysics, lunar basins and crustal layering, lunar magnetism, the lunar surface as a planetary probe, remote observations of lunar and planetary surfaces, earth-based measurements, integrated studies, physical properties of lunar materials, and asteroids, meteorites, and the early solar system. Attention is also given to studies of mare basalts, the kinetics of basalt crystallization, topical studies of mare basalts, highland rocks, experimental studies of highland rocks, geochemical studies of highland rocks, studies of materials of KREEP composition, a consortium study of lunar breccia 73215, topical studies on highland rocks, Venus, and regional studies of the moon. Studies of surface processes, are reported, taking into account cratering mechanics and fresh crater morphology, crater statistics and surface dating, effects of exposure and gardening, and the chemistry of surfaces.

  13. Nonlinear Science

    CERN Document Server

    Yoshida, Zensho

    2010-01-01

    This book gives a general, basic understanding of the mathematical structure "nonlinearity" that lies in the depths of complex systems. Analyzing the heterogeneity that the prefix "non" represents with respect to notions such as the linear space, integrability and scale hierarchy, "nonlinear science" is explained as a challenge of deconstruction of the modern sciences. This book is not a technical guide to teach mathematical tools of nonlinear analysis, nor a zoology of so-called nonlinear phenomena. By critically analyzing the structure of linear theories, and cl

  14. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 113; Issue 1. Identification of a surface layer structure and analysis of humidity data in two weather situations at Jodhpur (26° 18′N, 73° 04′E), India, during MONTBLEX 1990. N Das M Bose U K De. Volume 113 Issue 1 March 2004 pp 73-87 ...

  15. Bulletin of Materials Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    E N Aquino. Articles written in Bulletin of Materials Science. Volume 37 Issue 1 February 2014 pp 157-166 Electronic Supplementary Material. Characterization of neutrophil adhesion to different titanium surfaces · V Campos R C N Melo L P Silva E N Aquino M S Castro W Fontes · More Details Abstract Fulltext PDF.

  16. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 125; Issue 6. Issue front cover thumbnail. Volume 125, Issue 6. August 2016, pages 1089-1311. pp 1089-1102. Modelling surface run-off and trends analysis over India · P K Gupta S Chauhan M P Oza · More Details Abstract Fulltext PDF. The present study is mainly ...

  17. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    The Chandrayaan-1 mission to the Moon scheduled for launch in late 2007 will include a high energy X-ray spectrometer (HEX) for detection of naturally occurring emissions from the lunar surface due to radioactive decay of the 238U and 232Th series nuclides in the energy region 20 –250 keV.The primary science ...

  18. Journal of Chemical Sciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 127; Issue 10. Issue front cover thumbnail. Volume 127, Issue 10. October 2015, pages 1687-1869. pp 1687-1699. Modelling Gas Adsorption in Porous Solids: Roles of Surface Chemistry and Pore Architecture · Satyanarayana Bonakala Sundaram Balasubramanian.

  19. Bulletin of Materials Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 36; Issue 3. Issue front cover thumbnail. Volume 36, Issue 3. June 2013, pages 345-504. pp 345-351. Exploring a novel approach to fabricate vanadium carbide encapsulated into carbon nanotube (VC@C) with large specific surface area · Yifu Zhang Juecheng Zhang ...

  20. Proceedings – Mathematical Sciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Proceedings – Mathematical Sciences; Volume 123; Issue 1. One-Parameter Family of Solitons from Minimal Surfaces. Rukmini Dey Pradip Kumar. Volume 123 Issue 1 ... Author Affiliations. Rukmini Dey1 Pradip Kumar1. School of Mathematics, Harish Chandra Research Institute, Allahabad 211 019, India ...

  1. Proceedings – Mathematical Sciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Proceedings – Mathematical Sciences; Volume 113; Issue 2. The Weierstrass–Enneper Representation using Hodographic Coordinates on a Minimal Surface. Rukmini Dey. Volume ... Author Affiliations. Rukmini Dey1. School of Mathematics, Harish-Chandra Research Institute, Allahabad 211 019, India ...

  2. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 115; Issue 3. Volume 115, Issue 3. June 2006 ... Modeling of groundwater flow for Mujib aquifer, Jordan · Fayez Abdulla Tamer Al-Assa'd .... pp 349-362. Global surface temperature in relation to northeast monsoon rainfall over Tamil Nadu · S Balachandran R ...

  3. Journal of Chemical Sciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 126; Issue 4. Photoprocess of molecules encapsulated in porous solids X: Photosensitization of zeolite-Y encapsulated tris(2,2'-bipyridine-nickel-(II)ion by phenosafranine adsorbed onto the external surface of the nanoporous host. Karuppannan Senthil Kumar Sudha ...

  4. Bulletin of Materials Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 39; Issue 2. Efficiency of surface modified Ti coated with copper nanoparticles to control marine bacterial adhesion under laboratory simulated conditions. CHOKKALINGAM PRIYA GANESSIN ARAVIND WILSON RICHARD THILAGARAJ. Volume 39 Issue 2 April 2016 ...

  5. Proceedings – Mathematical Sciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Proceedings – Mathematical Sciences; Volume 115; Issue 3. Volume 115, Issue 3. August 2005, pages 241-369. pp 241-249. Some Properties of ... with some properties which are mathematically and statistically interesting. pp 251-257. Homeomorphisms and the Homology of Non-Orientable Surfaces.

  6. Proceedings – Mathematical Sciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Proceedings – Mathematical Sciences; Volume 114; Issue 2. A Variational Proof for the Existence of a Conformal Metric with Preassigned Negative Gaussian Curvature for Compact Riemann Surfaces of Genus >1. Rukmini Dey. Erratum Volume 114 Issue 2 May 2004 pp 215-215 ...

  7. Proceedings – Mathematical Sciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Proceedings – Mathematical Sciences; Volume 126; Issue 2. Volume 126, Issue 2. May 2016, pages 143-287. pp 143-151 Research Article. Existence of ..... pp 253-260 Research Article. Rigidity theorem forWillmore surfaces in a sphere · Hongwei Xu Dengyun Yang · More Details Abstract Fulltext PDF.

  8. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 122; Issue 1. Evaluation of OSCAR ocean surface current product in the tropical Indian Ocean using in situ data. Rajesh Sikhakolli Rashmi Sharma Sujit Basu B S Gohil Abhijit Sarkar K V S R Prasad. Volume 122 Issue 1 February 2013 pp 187-199 ...

  9. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 116; Issue 5. Volume 116, Issue 5. October 2007, pages 369-463. pp 369-384 ... pp 385-406. Link between convection and meridional gradient of sea surface temperature in the Bay of Bengal · D Shankar S R Shetye P V Joseph · More Details Abstract Fulltext PDF.

  10. Bulletin of Materials Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 39; Issue 4. Selective extraction and detection of noble metal based on ionic liquid immobilized silica gel surface using ICP-OES. HADI M MARWANI AMJAD E ALSAFRANI HAMAD A AL-TURAIF ABDULLAH M ASIRI SHER BAHADAR KHAN. Volume 39 Issue 4 August ...

  11. Bulletin of Materials Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 40; Issue 6. Facile synthesis and characterization of rough surface V 2 O 5 nanomaterials for pseudo-supercapacitor electrode material with high capacitance. YIFU ZHANG YUTING HUANG. Volume 40 Issue 6 October 2017 pp 1137-1149 ...

  12. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 115; Issue 4. Monsoon control on trace metal fluxes in the deep Arabian Sea. T M Balakrishnan Nair. Special Section on: Material exchanges at marine boundaries and surface ocean processes: Forcings and feedbacks Volume 115 Issue 4 August 2006 pp 461-472 ...

  13. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 111; Issue 3. Volume 111, Issue 3. September 2002, pages 187-378. Pan Ocean Remote Sensing Conference (PORSEC). pp 187-187. Preface · E Desa R Brown S Shenoi George Joseph · More Details Fulltext PDF. pp 189-195. Retrieval of sea surface velocities ...

  14. Activity Sourcebook for Earth Science. Science Education Information Report.

    Science.gov (United States)

    Mayer, Victor J., Ed.

    Designed to provide teachers of earth science with activities and information that will assist them in keeping their curricula up to date, this publication contains activities grouped into six chapters. Chapter titles are: (1) Weather and Climate, (2) Oceans, (3) The Earth and Its Surface, (4) Plate Tectonics, (5) Uses of Space Photography, and…

  15. Bulletin of Materials Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 30; Issue 4 ... Microwave materials; ceramic dielectric resonators; polytitanates; co-precipitation. ... hypotheses viz. diffusion, high surface and nucleation energy, potential barrier, non-stoichiometry etc as critical factors limiting formation of 2 : 9 as single-phase material.

  16. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    T M Balakrishnan Nair. Articles written in Journal of Earth System Science. Volume 115 Issue 4 August 2006 pp 461-472 Special Section on: Material exchanges at marine boundaries and surface ocean processes: Forcings and feedbacks. Monsoon control on trace metal fluxes in the deep Arabian Sea · T M Balakrishnan ...

  17. Bulletin of Materials Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    School of Chemical and Materials Engineering, National University of Science and Technology, H/12 Islamabad, Pakistan; Austrian Institute of Technology GmbH, Advanced Materials & Aerospace Technologies, A-2444 Seibersdorf, Austria; Centre of Electrochemical Surface Technology, A-2700 Wiener Neustadt, Austria ...

  18. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 120; Issue 3. Volume 120, Issue 3. June 2011, pages 337-556. pp 337-345. Atmospheric correction for sea surface temperature retrieval from single thermal channel radiometer data onboard Kalpana satellite · Naveen R Shahi Neeraj Agarwal Aloke K Mathur ...

  19. Proceedings – Mathematical Sciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Using Ramanujan's identities and the Weierstrass--Enneper representation of minimal surfaces, and the analogue for Born--Infeld solitons, we derive further nontrivial identities. Author Affiliations. RUKMINI DEY1. International Centre for Theoretical Sciences (ICTS)-TIFR, Survey No. 151, Shivakote, Hesaraghatta ...

  20. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 126; Issue 5. Assessment of large aperture scintillometry for large-area surface energy fluxes over an irrigated cropland in north India. Abhishek Danodia V K Sehgal N R Patel R Dhakar J Mukherjee S K Saha A Senthil Kumar. Volume 126 Issue 5 July 2017 Article ...

  1. Adhesion energy, surface traction and surface tension in liquid xenon

    Indian Academy of Sciences (India)

    2015-11-27

    Nov 27, 2015 ... Home; Journals; Pramana – Journal of Physics; Volume 77; Issue 6. Adhesion energy, surface ... 2 G A Adebayo1. Department of Physics, University of Agriculture, Abeokuta, Nigeria; Department of Pure and Applied Physics, College of Pure and Applied Science, Caleb University, Imota, Lagos, Nigeria ...

  2. Emulsion Science Basic Principles

    CERN Document Server

    Leal-Calderon, Fernando; Schmitt, Véronique

    2007-01-01

    Emulsions are generally made out of two immiscible fluids like oil and water, one being dispersed in the second in the presence of surface-active compounds.They are used as intermediate or end products in a huge range of areas including the food, chemical, cosmetic, pharmaceutical, paint, and coating industries. Besides the broad domain of technological interest, emulsions are raising a variety of fundamental questions at the frontier between physics and chemistry. This book aims to give an overview of the most recent advances in emulsion science. The basic principles, covering aspects of emulsions from their preparation to their destruction, are presented in close relation to both the fundamental physics and the applications of these materials. The book is intended to help scientists and engineers in formulating new materials by giving them the basics of emulsion science.

  3. Cognitive Science.

    Science.gov (United States)

    Cocking, Rodney R.; Mestre, Jose P.

    The focus of this paper is on cognitive science as a model for understanding the application of human skills toward effective problem-solving. Sections include: (1) "Introduction" (discussing information processing framework, expert-novice distinctions, schema theory, and learning process); (2) "Application: The Expert-Novice…

  4. Talking Science

    Science.gov (United States)

    Eley, Alison

    2011-01-01

    The Talking Science project initially involved three secondary schools and eight of their feeder primary schools in the London Borough of Richmond Upon Thames. The project created, trialled and evaluated a set of key stage 2/3 transition materials for children moving from primary to secondary school, using argument as a teaching and learning…

  5. Marine Science

    African Journals Online (AJOL)

    Aims and scope: The Western Indian Ocean Journal of Marine Science provides an avenue for the wide dissem- .... Kaullysing et al. also present a field note on coral-eating gastropods observed around Mauritius. ... and decision making in the field of coral reef studies and management in Mauritius, while contributing.

  6. Marine Science

    African Journals Online (AJOL)

    Micro-phytoplankton density, C-biomass and diversity. Tides and zones had significant effects on the over- all total C-biomass of total micro-phytoplankton and bacillariophytes, and concentrations of ...... to environmental parameters in cage culture area of Sepanggar Bay, Malaysia. Estuarine Coastal and. Shelf Science 80: ...

  7. Marine Science

    African Journals Online (AJOL)

    The journal publishes original research articles dealing with all aspects of marine science and coastal manage- ment. Topics include, but are not limited to: theoretical studies, oceanography, marine biology and ecology, fisheries, recovery and restoration processes, legal and institutional frameworks, and interactions/ ...

  8. Systems Science

    Science.gov (United States)

    Christakis, Alexander; Hammond, Debora; Jackson, Michael; Laszlo, Alexander; Mitroff, Ian; Snowden, Dave; Troncale, Len; Carr-Chellman, Alison; Spector, J. Michael; Wilson, Brent

    2013-01-01

    Scholars representing the field of systems science were asked to identify what they considered to be the most exciting and imaginative work currently being done in their field, as well as how that work might change our understanding. The scholars included Alexander Christakis, Debora Hammond, Michael Jackson, Alexander Laszlo, Ian Mitroff, Dave…

  9. Marine Science

    African Journals Online (AJOL)

    fisheries, recovery and restoration processes, legal and institutional frameworks, and interactions/relationships between ... ISSN 0856-860X. Western Indian Ocean. J O U R N A L O F. Marine Science. Editorial Board. Serge ANDREFOUËT. France. Ranjeet BHAGOOLI. Mauritius ...... ence Technology, Rhodes, Greece.

  10. Science Smiles

    Indian Academy of Sciences (India)

    IAS Admin

    Page 1. 666. RESONANCE | August 2015. Science Smiles. Ayan Guha. Email for Correspondence: ionguha@gmail.com. Oduvai Gorge gives us one of the most remarkable stories of the past – the last chapter of the Earth's history, starting at the present day, right away back 2 million years.

  11. Science Smiles

    Indian Academy of Sciences (India)

    Page 1. 75. RESONANCE │ January 2011. BOOK │ REVIEW. Science Smiles. Ayan Guha. Email for Correspondence: ionguha@gmail.com. What if I say that all the people living in our United Netherlands are not as many as the animalcules living in this single drop of water.

  12. Science Smiles

    Indian Academy of Sciences (India)

    Page 1. Science Smiles. RKLaxman. I bought the plot to build my office. But the activists would not let me touch anything lest it should upset the ecological balance here. R -E-SO-N-A-N-C-E -, -Fe-b-ru-ary-19-9-S -----~-------------

  13. Skeptical Science.

    Science.gov (United States)

    Scott, Alan J.; Barnhart, Carolyn M.; Parejko, Ken S.; Schultz, Forrest S.; Schultz, Steven E.

    2001-01-01

    Discusses the legitimacy of teaching about astrology, extrasensory perception, UFOs, touch therapy, cloning dinosaurs, or any other unusual claims in the classroom. Suggests that bringing unusual claims to the science classroom is an opportunity to motivate students in the principles of scientific thought. (SAH)

  14. Marine Science

    African Journals Online (AJOL)

    Aims and scope: The Western Indian Ocean Journal of Marine Science provides an avenue for the wide dissem- ination of high quality research ... PAHs are among the persistent organic pollutants that are a worldwide environmental ... combusted and petroleum products are used during boat/dhow making and servicing ...

  15. Actuarial Science.

    Science.gov (United States)

    Warren, Bette

    1982-01-01

    Details are provided of a program on actuarial training developed at the State University of New York (SUNY) at Binghamton through the Department of Mathematical Sciences. An outline of its operation, including a few statistics on students in the program, is included. (MP)

  16. Marine Science

    African Journals Online (AJOL)

    org/wio-journal-of-marine- science/ and AJOL ... The mangroves around Maputo city in Maputo Bay were studied to assess changes in forest cover area and the effect of cutting ..... factors on forest health condition has not yet been assessed.

  17. Organizational Science

    Science.gov (United States)

    Beriwal, Madhu; Clegg, Stewart; Collopy, Fred; McDaniel, Reuben, Jr.; Morgan, Gareth; Sutcliffe, Kathleen; Kaufman, Roger; Marker, Anthony; Selwyn, Neil

    2013-01-01

    Scholars representing the field of organizational science, broadly defined as including many fields--organizational behavior and development, management, workplace performance, and so on--were asked to identify what they considered to be the most exciting and imaginative work currently being done in their field, as well as how that work might…

  18. Redirecting science

    International Nuclear Information System (INIS)

    Aaserud, F.

    1990-01-01

    This book contains the following chapters. Science policy and fund-raising up to 1934; The Copenhagen spirit at work, late 1920's to mid-1930s; The refugee problem, 1933 to 1935; Experimental biology, late 1920s to 1935; and Consolidation of the transition, 1935 to 1940

  19. Marine Science

    African Journals Online (AJOL)

    Aims and scope: The Western Indian Ocean Journal of Marine Science provides an avenue for the wide dissem- ination of high quality research generated in the Western Indian Ocean (WIO) region, in particular on the sustainable use of coastal and marine resources. This is central to the goal of supporting and promoting.

  20. Science Notes.

    Science.gov (United States)

    Talbot, Chris; And Others

    1991-01-01

    Twenty science experiments are presented. Topics include recombinant DNA, physiology, nucleophiles, reactivity series, molar volume of gases, spreadsheets in chemistry, hydrogen bonding, composite materials, radioactive decay, magnetism, speed, charged particles, compression waves, heat transfer, Ursa Major, balloons, current, and expansion of…

  1. Boundless Science

    Science.gov (United States)

    Spilhaus, F.

    2009-04-01

    Our science is critical to understanding the future prospects for life. The laboratory for natural sciences encompasses our planet and reaches into the solar system. The forces of nature respect no boundaries. But, we who try to understand these forces are handicapped by national, political, language, religious, and other concocted barriers. These barriers limit both our effectiveness as scientists and our ability to reach those outside our community who need to know what we have uncovered about our environment. An unencumbered worldwide scientific community has been an objective with limited successes for too long. Action began in earnest after the first world war with the formation of the various scientific Unions and ICSU. Fifty years later Keith Runcorn initiated another approach, when he proposed what quickly became EGS and which has grown and evolved with the merger with EUG. To be truly effective we need to communicate and share comfortably with colleagues worldwide. Personal relationships and trust are required. We count on a high level of ethical behavior within our community. We individually must also be constantly vigilant for the encroachment of the manmade barriers that have held back science through time immemorial. Our scientific organizations cannot achieve this alone. They will facilitate, however, the onus is on each of us to reach out and form interlocking informal communities, which will bring our whole planet-wide community together at many overlapping levels. When we achieve this community, our science will more bountiful and better address the needs of human society.

  2. Science and anti-science

    CERN Document Server

    Holton, Gerald

    1997-01-01

    What is good science? What goal--if any--is the proper end of scientific activity? Is there a legitimating authority that scientists mayclaim? Howserious athreat are the anti-science movements? These questions have long been debated but, as Gerald Holton points out, every era must offer its own responses. This book examines these questions not in the abstract but shows their historic roots and the answers emerging from the scientific and political controversies of this century. Employing the case-study method and the concept of scientific thematathat he has pioneered, Holton displays the broad scope of his insight into the workings of science: from the influence of Ernst Mach on twentiethcentury physicists, biologists, psychologists, and other thinkers to the rhetorical strategies used in the work of Albert Einstein, Niels Bohr, and others; from the bickering between Thomas Jefferson and the U.S. Congress over the proper form of federal sponsorship of scientific research to philosophical debates since Oswald...

  3. Bulletin of Materials Science | News

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 36; Issue 3. Issue front cover thumbnail. Volume 36, Issue 3. June 2013, pages 345-504. pp 345-351. Exploring a novel approach to fabricate vanadium carbide encapsulated into carbon nanotube (VC@C) with large specific surface area · Yifu Zhang Juecheng Zhang ...

  4. Bulletin of Materials Science | News

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 35; Issue 6. Issue front cover ... pp 925-931. Surface modified Al2O3 in fluorinated polyimide/Al2O3 nanocomposites: Synthesis and characterization .... Studies on electrical conductivity and dielectric behaviour of PVdF–HFP–PMMA–NaI polymer blend electrolyte.

  5. Sadhana | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Finally, the optimal cutting parameters and model equations to predict the surface roughness and microhardness are proposed. Volume 40 Issue 2 April 2015 pp 335-350 Electrical and Computer Sciences. A computerized loop based approach for identification of isomorphism and type of mobility in planar kinematic chains.

  6. Ensemble forecasts of road surface temperatures

    Czech Academy of Sciences Publication Activity Database

    Sokol, Zbyněk; Bližňák, Vojtěch; Sedlák, Pavel; Zacharov, Petr, jr.; Pešice, Petr; Škuthan, M.

    2017-01-01

    Roč. 187, 1 May (2017), s. 33-41 ISSN 0169-8095 R&D Projects: GA ČR GA13-34856S; GA TA ČR(CZ) TA01031509 Institutional support: RVO:68378289 Keywords : ensemble prediction * road surface temperature * road weather forecast Subject RIV: DG - Athmosphere Sciences, Meteorology OBOR OECD: Meteorology and atmospheric sciences Impact factor: 3.778, year: 2016 http://www.sciencedirect.com/science/article/pii/S0169809516307311

  7. Teaching heroics: Identity and ethical imagery in science education

    Science.gov (United States)

    Robeck, Edward C.

    In what follows, I address ways in which science education can influence personal identity and social relationships. I do this through a consideration of ideological implications of science as it is constituted in science education. In this situation, I consider science to be a symbolic--emanating from socially derived meanings. I begin with the premise that any symbol system is permeated with ideological elements. To highlight the ideological elements of science in science education, I use another more explicitly symbolic system as a comparative framework. That system is epic heroism, primarily as Joseph Campbell (1949) describes it in The Hero With A Thousand Faces. The discussion of science education is given a practical grounding using transcripts from the interviews with twenty Grade 10 students and many of their teachers undertaken in the 1993-1994 school year. I used epic heroism as a framework for initiating interpretations of broad themes from the transcripts, but also read the transcripts in relation to aspects of epic heroism, including existing critiques of Campbell's work and heroism more broadly. Specific quotes are included to illustrations of various points. My particular focus here is on ideological elements that can be associated with racism, sexism, and other social relationships that are collectively referred to as relations involving divisive bias. In particular, two themes are discussed extensively. The first is the theme of identity formed through separation, which results in the promotion of reductive and individualistic identities. The second theme has to do with the role of boundary imagery in the formation of relationship, which establishes difference hierarchically. Both of these are pervasive in divisive bias and in the imagery of epic heroism. Ways in which they can pervade practices in science education are also discussed. The central argument of the thesis is that science education, when undertaken through practices that incorporate

  8. Caring Science or Science of Caring.

    Science.gov (United States)

    Turkel, Marian C; Watson, Jean; Giovannoni, Joseph

    2018-01-01

    The concepts caring science and science of caring have different meanings; however, they are often used interchangeably. The purpose of this paper is to present an overview of the synthesis of the scholarly literature on the definitions of the science of caring and caring science and to affirm the authors' perspective relating to the language of caring science. Caring science advances the epistemology and ontology of caring. Ideas related to caring science inquiry are presented, and the authors acknowledge the future of caring science as unitary caring science.

  9. Portraying Real Science in Science Communication

    Science.gov (United States)

    van Dijk, Esther M.

    2011-01-01

    In both formal and informal settings, not only science but also views on the nature of science are communicated. Although there probably is no singular nature shared by all fields of science, in the field of science education it is commonly assumed that on a certain level of generality there is a consensus on many features of science. In this…

  10. Nanoplasmonic sensors for biointerfacial science.

    Science.gov (United States)

    Jackman, Joshua A; Rahim Ferhan, Abdul; Cho, Nam-Joon

    2017-06-19

    In recent years, nanoplasmonic sensors have become widely used for the label-free detection of biomolecules across medical, biotechnology, and environmental science applications. To date, many nanoplasmonic sensing strategies have been developed with outstanding measurement capabilities, enabling detection down to the single-molecule level. One of the most promising directions has been surface-based nanoplasmonic sensors, and the potential of such technologies is still emerging. Going beyond detection, surface-based nanoplasmonic sensors open the door to enhanced, quantitative measurement capabilities across the biointerfacial sciences by taking advantage of high surface sensitivity that pairs well with the size of medically important biomacromolecules and biological particulates such as viruses and exosomes. The goal of this review is to introduce the latest advances in nanoplasmonic sensors for the biointerfacial sciences, including ongoing development of nanoparticle and nanohole arrays for exploring different classes of biomacromolecules interacting at solid-liquid interfaces. The measurement principles for nanoplasmonic sensors based on utilizing the localized surface plasmon resonance (LSPR) and extraordinary optical transmission (EOT) phenomena are first introduced. The following sections are then categorized around different themes within the biointerfacial sciences, specifically protein binding and conformational changes, lipid membrane fabrication, membrane-protein interactions, exosome and virus detection and analysis, and probing nucleic acid conformations and binding interactions. Across these themes, we discuss the growing trend to utilize nanoplasmonic sensors for advanced measurement capabilities, including positional sensing, biomacromolecular conformation analysis, and real-time kinetic monitoring of complex biological interactions. Altogether, these advances highlight the rich potential of nanoplasmonic sensors and the future growth prospects of

  11. Surface chemistry in three dimensions

    DEFF Research Database (Denmark)

    Bollinger, Mikkel; Jacobsen, Karsten Wedel; Nørskov, Jens Kehlet

    2000-01-01

    the usual single surface ('2D') process because indirect adsorbate-adsorbate interactions in the transition state are absent in the '3D' case. The prospects for STM-induced single molecule chemistry and for '3D' catalysts are discussed. (C) 2000 Elsevier Science B.V. All rights reserved.......Based on self-consistent density functional calculations it is shown that a new dissociation process for CO adsorbed on a Ru(0001) surface is made possible when the distance to a second Ru(0001) surface placed just above it is below some critical value. This '3D' process is more facile than...

  12. Surface boxplots

    KAUST Repository

    Genton, Marc G.

    2014-01-22

    In this paper, we introduce a surface boxplot as a tool for visualization and exploratory analysis of samples of images. First, we use the notion of volume depth to order the images viewed as surfaces. In particular, we define the median image. We use an exact and fast algorithm for the ranking of the images. This allows us to detect potential outlying images that often contain interesting features not present in most of the images. Second, we build a graphical tool to visualize the surface boxplot and its various characteristics. A graph and histogram of the volume depth values allow us to identify images of interest. The code is available in the supporting information of this paper. We apply our surface boxplot to a sample of brain images and to a sample of climate model outputs.

  13. Convex surfaces

    CERN Document Server

    Busemann, Herbert

    2008-01-01

    This exploration of convex surfaces focuses on extrinsic geometry and applications of the Brunn-Minkowski theory. It also examines intrinsic geometry and the realization of intrinsic metrics. 1958 edition.

  14. New Measures Assessing Predictors of Academic Persistence for Historically Underrepresented Racial/Ethnic Undergraduates in Science

    Science.gov (United States)

    Byars-Winston, Angela; Rogers, Jenna; Branchaw, Janet; Pribbenow, Christine; Hanke, Ryan; Pfund, Christine

    2016-01-01

    An important step in broadening participation of historically underrepresented (HU) racial/ethnic groups in the sciences is the creation of measures validated with these groups that will allow for greater confidence in the results of investigations into factors that predict their persistence. This study introduces new measures of theoretically derived factors emanating from social cognitive and social identity theories associated with persistence for HU racial/ethnic groups in science disciplines. The purpose of this study was to investigate: 1) the internal reliability and factor analyses for measures of research-related self-efficacy beliefs, sources of self-efficacy, outcome expectations, and science identity; and 2) potential group differences in responses to the measures, examining the main and interaction effects of gender and race/ethnicity. Survey data came from a national sample of 688 undergraduate students in science majors who were primarily black/African American and Hispanic/Latino/a with a 2:1 ratio of females to males. Analyses yielded acceptable validity statistics and race × gender group differences were observed in mean responses to several measures. Implications for broadening participation of HU groups in the sciences are discussed regarding future tests of predictive models of student persistence and training programs to consider cultural diversity factors in their design. PMID:27521235

  15. Surface decontamination

    International Nuclear Information System (INIS)

    Silva, S. da; Teixeira, M.V.

    1986-06-01

    The general methods of surface decontamination used in laboratory and others nuclear installations areas, as well as the procedures for handling radioactive materials and surfaces of work are presented. Some methods for decontamination of body external parts are mentioned. The medical supervision and assistance are required for internal or external contamination involving or not lesion in persons. From this medical radiation protection decontamination procedures are determined. (M.C.K.) [pt

  16. Bayesian optimization for materials science

    CERN Document Server

    Packwood, Daniel

    2017-01-01

    This book provides a short and concise introduction to Bayesian optimization specifically for experimental and computational materials scientists. After explaining the basic idea behind Bayesian optimization and some applications to materials science in Chapter 1, the mathematical theory of Bayesian optimization is outlined in Chapter 2. Finally, Chapter 3 discusses an application of Bayesian optimization to a complicated structure optimization problem in computational surface science. Bayesian optimization is a promising global optimization technique that originates in the field of machine learning and is starting to gain attention in materials science. For the purpose of materials design, Bayesian optimization can be used to predict new materials with novel properties without extensive screening of candidate materials. For the purpose of computational materials science, Bayesian optimization can be incorporated into first-principles calculations to perform efficient, global structure optimizations. While re...

  17. Surface phonons

    CERN Document Server

    Wette, Frederik

    1991-01-01

    In recent years substantial progress has been made in the detection of surface phonons owing to considerable improvements in inelastic rare gas scattering tech­ niques and electron energy loss spectroscopy. With these methods it has become possible to measure surface vibrations in a wide energy range for all wave vectors in the two-dimensional Brillouin zone and thus to deduce the complete surface phonon dispersion curves. Inelastic atomic beam scattering and electron energy loss spectroscopy have started to play a role in the study of surface phonons similar to the one played by inelastic neutron scattering in the investigation of bulk phonons in the last thirty years. Detailed comparison between experimen­ tal results and theoretical studies of inelastic surface scattering and of surface phonons has now become feasible. It is therefore possible to test and to improve the details of interaction models which have been worked out theoretically in the last few decades. At this point we felt that a concise, co...

  18. Surface texture measurement for dental wear applications

    Science.gov (United States)

    Austin, R. S.; Mullen, F.; Bartlett, D. W.

    2015-06-01

    The application of surface topography measurement and characterization within dental materials science is highly active and rapidly developing, in line with many modern industries. Surface measurement and structuring is used extensively within oral and dental science to optimize the optical, tribological and biological performance of natural and biomimetic dental materials. Although there has historically been little standardization in the use and reporting of surface metrology instrumentation and software, the dental industry is beginning to adopt modern areal measurement and characterization techniques, especially as the dental industry is increasingly adopting digital impressioning techniques in order to leverage CAD/CAM technologies for the design and construction of dental restorations. As dental treatment becomes increasingly digitized and reliant on advanced technologies such as dental implants, wider adoption of standardized surface topography and characterization techniques will become evermore essential. The dental research community welcomes the advances that are being made in surface topography measurement science towards realizing this ultimate goal.

  19. Earth Systems Science in an Integrated Science Content and Methods Course for Elementary Education Majors

    Science.gov (United States)

    Madsen, J. A.; Allen, D. E.; Donham, R. S.; Fifield, S. J.; Shipman, H. L.; Ford, D. J.; Dagher, Z. R.

    2004-12-01

    With funding from the National Science Foundation, we have designed an integrated science content and methods course for sophomore-level elementary teacher education (ETE) majors. This course, the Science Semester, is a 15-credit sequence that consists of three science content courses (Earth, Life, and Physical Science) and a science teaching methods course. The goal of this integrated science and education methods curriculum is to foster holistic understandings of science and pedagogy that future elementary teachers need to effectively use inquiry-based approaches in teaching science in their classrooms. During the Science Semester, traditional subject matter boundaries are crossed to stress shared themes that teachers must understand to teach standards-based elementary science. Exemplary approaches that support both learning science and learning how to teach science are used. In the science courses, students work collaboratively on multidisciplinary problem-based learning (PBL) activities that place science concepts in authentic contexts and build learning skills. In the methods course, students critically explore the theory and practice of elementary science teaching, drawing on their shared experiences of inquiry learning in the science courses. An earth system science approach is ideally adapted for the integrated, inquiry-based learning that takes place during the Science Semester. The PBL investigations that are the hallmark of the Science Semester provide the backdrop through which fundamental earth system interactions can be studied. For example in the PBL investigation that focuses on energy, the carbon cycle is examined as it relates to fossil fuels. In another PBL investigation centered on kids, cancer, and the environment, the hydrologic cycle with emphasis on surface runoff and ground water contamination is studied. In a PBL investigation that has students learning about the Delaware Bay ecosystem through the story of the horseshoe crab and the biome

  20. The Science in Science Fiction.

    Science.gov (United States)

    Nicholls, Peter, Ed.

    This 12-chapter book discusses the scientific facts behind the ideas included in the novels of Robert Heinlein, Isaac Asimov, Frederik Pohl, Arthur C. Clark and other science fiction writers. Areas explored in the first 11 chapters include: exploration of deep space; energy and exotic power sources; likelihood of extra-terrestrial life and the…

  1. Nanofins science and applications

    CERN Document Server

    Singh, Navdeep

    2014-01-01

    Nanofins Science and Technology describes the heat transfer effectiveness of polymer coolants and their fundamental interactions with carbon nanotube coatings that act as nanofins. Heat transfer at micro/nano-scales has attracted significant attention in contemporary literature. This has been primarily driven by industrial requirements where significant decrease in the size of electronic devices/chips with concomitant enhancement in the heat flux have caused challenging needs for cooling of these platforms. With quantum effects kicking in, traditional cooling techniques need to be replaced with more effective technologies. A promising technique is to enhance heat transfer by surface texturing using nanoparticle coatings or engineered nanostructures. These nanostructures are termed as nanofins because they augment heat transfer by a combination of surface area enhancement as well as liquid-solid interactions at the molecular scale.

  2. Surface treatments for improved performance and properties

    International Nuclear Information System (INIS)

    Burke, J.J.; Weiss, V.

    1982-01-01

    This book considers the characteristics, structures, and properties of surfaces. Divides the subject into the physical and chemical characteristics of metallic and nonmetallic surfaces, emerging surface modification techniques, surface structure and mechanical properties, and relationships between properties and processing for nonmetallic materials. Explores various methods of surface modification that can produce improved materials properties. Discusses such wide-ranging topics as the characterization of surfaces, reaction kinetics, the chemistry of gaseous hydrogen embrittlement, the effect of surface modification on corrosion, protection against high-temperature corrosion of surfaces, the effect of high temperatures developed during plating on the microstructure and microhardness of steel, near-surface modifications that will improve the crack-tolerant behavior of high-strength alloys, fretting corrosion and fretting fatigue, surface treatments for enhanced bonding between inorganic surfaces and polymers, and the relationships between surface structure, ceramic processing, and mechanical properties. Recommended for workers and researchers in materials science, surface science, and mechanical engineering. Constitutes the proceedings of the Twenty-sixth Sagamore Army Materials Research Conference (entitled ''Surface Treatments for Improved Performance and Properties'') held in New York in 1979

  3. Computer sciences

    Science.gov (United States)

    Smith, Paul H.

    1988-01-01

    The Computer Science Program provides advanced concepts, techniques, system architectures, algorithms, and software for both space and aeronautics information sciences and computer systems. The overall goal is to provide the technical foundation within NASA for the advancement of computing technology in aerospace applications. The research program is improving the state of knowledge of fundamental aerospace computing principles and advancing computing technology in space applications such as software engineering and information extraction from data collected by scientific instruments in space. The program includes the development of special algorithms and techniques to exploit the computing power provided by high performance parallel processors and special purpose architectures. Research is being conducted in the fundamentals of data base logic and improvement techniques for producing reliable computing systems.

  4. 2013 Chemical reactions at surfaces. Surfaces in Energy and the Environment. Gordon Research Conference and Gordon Research Seminar (April 28 - May 3, 2013 - Les Diablerets, Switzerland)

    Energy Technology Data Exchange (ETDEWEB)

    Stair, Peter C. [Northwestern Univ., Evanston, IL (United States)

    2013-02-03

    presentations on chemistry at solid and liquid surfaces of relevance to catalysis, synthesis, photochemistry, environmental science, and tribology. Topics include: Fundamental Surface Chemistry; Catalysis; Solid Liquid and Aerosol Interfaces; Surface Photochemistry; Synthesis of Surfaces; Environmental Interfaces; Hot Topics in Surface Chemical Reactions; Tribology; Gas-Surface Scattering and Reactions; Novel Materials and Environments.

  5. Mechanical science

    CERN Document Server

    Bolton, W C

    2013-01-01

    This book gives comprehensive coverage of mechanical science for HNC/HND students taking mechanical engineering courses, including all topics likely to be covered in both years of such courses, as well as for first year undergraduate courses in mechanical engineering. It features 500 problems with answers and 200 worked examples. The third edition includes a new section on power transmission and an appendix on mathematics to help students with the basic notation of calculus and solution of differential equations.

  6. Specialized science.

    Science.gov (United States)

    Casadevall, Arturo; Fang, Ferric C

    2014-04-01

    As the body of scientific knowledge in a discipline increases, there is pressure for specialization. Fields spawn subfields that then become entities in themselves that promote further specialization. The process by which scientists join specialized groups has remarkable similarities to the guild system of the middle ages. The advantages of specialization of science include efficiency, the establishment of normative standards, and the potential for greater rigor in experimental research. However, specialization also carries risks of monopoly, monotony, and isolation. The current tendency to judge scientific work by the impact factor of the journal in which it is published may have roots in overspecialization, as scientists are less able to critically evaluate work outside their field than before. Scientists in particular define themselves through group identity and adopt practices that conform to the expectations and dynamics of such groups. As part of our continuing analysis of issues confronting contemporary science, we analyze the emergence and consequences of specialization in science, with a particular emphasis on microbiology, a field highly vulnerable to balkanization along microbial phylogenetic boundaries, and suggest that specialization carries significant costs. We propose measures to mitigate the detrimental effects of scientific specialism.

  7. Communicating Science

    Science.gov (United States)

    Holland, G. J.; McCaffrey, M. S.; Kiehl, J. T.; Schmidt, C.

    2010-12-01

    We are in an era of rapidly changing communication media, which is driving a major evolution in the modes of communicating science. In the past, a mainstay of scientific communication in popular media was through science “translators”; science journalists and presenters. These have now nearly disappeared and are being replaced by widespread dissemination through, e.g., the internet, blogs, YouTube and journalists who often have little scientific background and sharp deadlines. Thus, scientists are required to assume increasing responsibility for translating their scientific findings and calibrating their communications to non-technical audiences, a task for which they are often ill prepared, especially when it comes to controversial societal issues such as tobacco, evolution, and most recently climate change (Oreskes and Conway 2010). Such issues have been politicized and hi-jacked by ideological belief systems to such an extent that constructive dialogue is often impossible. Many scientists are excellent communicators, to their peers. But this requires careful attention to detail and logical explanation, open acknowledgement of uncertainties, and dispassionate delivery. These qualities become liabilities when communicating to a non-scientific audience where entertainment, attention grabbing, 15 second sound bites, and self assuredness reign (e.g. Olson 2009). Here we report on a program initiated by NCAR and UCAR to develop new approaches to science communication and to equip present and future scientists with the requisite skills. If we start from a sound scientific finding with general scientific consensus, such as the warming of the planet by greenhouse gases, then the primary emphasis moves from the “science” to the “art” of communication. The art cannot have free reign, however, as there remains a strong requirement for objectivity, honesty, consistency, and above all a resistance to advocating particular policy positions. Targeting audience

  8. Changes on Titan's surface

    Science.gov (United States)

    Solomonidou, A.; Lopes, R. M. C.; Coustenis, A.; Malaska, M. J.; Sotin, C.; Rodriguez, S.; Janssen, M. A.; Drossart, P.; Lawrence, K. J.; Matsoukas, C. K.; Hirtzig, M.; Le Mouelic, S.; Jaumann, R.; Brown, R. H.; Bratsolis, E.

    2015-12-01

    Cassini's Visual and Infrared Mapping Spectrometer (VIMS) and the Titan Radar Mapper have investigated Titan's surface since 2004, unveiling a complex, dynamic and Earth-like surface. Understanding the distribution and interplay of geologic processes is important for constraining models of its interior, surface-atmospheric interactions, and climate evolution. We focus on understanding the origin of the major geomorphological units identified by Lopes et al. (2010, 2015) [1,2], Malaska et al. (2015) [3] and regions we studied in Solomonidou et al. (2014; 2015) [4,5]. Here, we investigate the nature of: Undifferentiated Plains, Hummocky/Mountainous terrains, candidate cryovolcanic sites, Labyrinth, and Dunes in terms of surface albedo behavior and spectral evolution with time to identify possible changes. Using a radiative transfer code, we find that temporal variations of surface albedo occur for some areas. Tui Regio and Sotra Patera, both candidate cryovolcanic regions, change with time, becoming darker and brighter respectively in surface albedo. In contrast, we find that the Undifferentiated Plains and the suggested evaporitic areas [6] in the equatorial regions do not present any significant changes. We are able to report the differences and similarities among the various regions and provide constraints on their chemical composition and specific processes of origin. Our results support the hypothesis that both endogenic and exogenic processes have played important roles in shaping Titan's geologic evolution. Such a variety of geologic processes and their relationship to the methane cycle make Titan important for astrobiology and habitability studies and particularly significant in solar system studies. [1] Lopes, R.M.C., et al.: Icarus, 205, 540-588, 2010; [2] Lopes, R.M.C., et al.: JGR, 118, 416-435, 2013; [3] Malaska, M., et al : Icarus, submitted, 2015;[4] Solomonidou et al.: JGR, 119, 1729-1747, 2014; [5] Solomonidou, A., et al.: In press, 2015; [6] Barnes

  9. Ice Surfaces

    Science.gov (United States)

    Shultz, Mary Jane

    2017-05-01

    Ice is a fundamental solid with important environmental, biological, geological, and extraterrestrial impact. The stable form of ice at atmospheric pressure is hexagonal ice, Ih. Despite its prevalence, Ih remains an enigmatic solid, in part due to challenges in preparing samples for fundamental studies. Surfaces of ice present even greater challenges. Recently developed methods for preparation of large single-crystal samples make it possible to reproducibly prepare any chosen face to address numerous fundamental questions. This review describes preparation methods along with results that firmly establish the connection between the macroscopic structure (observed in snowflakes, microcrystallites, or etch pits) and the molecular-level configuration (detected with X-ray or electron scattering techniques). Selected results of probing interactions at the ice surface, including growth from the melt, surface vibrations, and characterization of the quasi-liquid layer, are discussed.

  10. Collaborative Science: Human Sensor Networks for Real-time Natural Disaster Prediction

    Science.gov (United States)

    Halem, M.; Yesha, Y.; Aulov, O.; Martineau, J.; Brown, S.; Conte, T.; CenterHybrid Multicore Productivity Research

    2010-12-01

    We have implemented a ‘Human Sensor Network’ as a real time collaborative science data observing system by collecting and integrating the vast untapped information potential of digital social media data sources occurring during the oil spill situation arising from the Macondo well in the Gulf of Mexico. We collected, and archived blogs, Twitter status updates (aka tweets), photographs posted to Flicker, and videos posted to YouTube related to the Gulf oil spill and processed the meta data, text, and photos to extract quantitative physical data such as locations and estimates of the severity and dispersion of oil being collected on the beaches and marshes, frequencies of observations of tar ball sightings, correlations of sightings from different media, numbers of dead or distressed animals, trends, etc. These data were then introduced into the NOAA operational Gnome oil spill predictive model as time dependent boundary conditions employing a 2-D variational data assimilation scheme. The three participating institutions employed a distributed cloud computing system for the processing and model executions. In this presentation, we conducted preliminary forecast impact tests of the Gnome model with and without the use of social media data using a 2-D variational data assimilation technique. The 2-D VAR is used to adjust the state variables of the model by recursively minimizing the differences between oil spill predictions reaching locations across the entire coastlines of the Gulf of Mexico and the estimated positions of oil derived from analyzed social media data. Ensemble forecasts will be performed to provide estimates of the rates of oil and surface oil distributions emanating from the Deepwater Horizon. We display the derived predictions from the photos and animations from Flicker, YouTube, and extracted content from tweets and blogs in a dynamic representation on very large tiled walls of LCDs at the UCSD Cal IT2 visualization facility. We describe the

  11. Life sciences and environmental sciences

    Energy Technology Data Exchange (ETDEWEB)

    1992-02-01

    The DOE laboratories play a unique role in bringing multidisciplinary talents -- in biology, physics, chemistry, computer sciences, and engineering -- to bear on major problems in the life and environmental sciences. Specifically, the laboratories utilize these talents to fulfill OHER`s mission of exploring and mitigating the health and environmental effects of energy use, and of developing health and medical applications of nuclear energy-related phenomena. At Lawrence Berkeley Laboratory (LBL) support of this mission is evident across the spectrum of OHER-sponsored research, especially in the broad areas of genomics, structural biology, basic cell and molecular biology, carcinogenesis, energy and environment, applications to biotechnology, and molecular, nuclear and radiation medicine. These research areas are briefly described.

  12. Life sciences and environmental sciences

    Energy Technology Data Exchange (ETDEWEB)

    1992-02-01

    The DOE laboratories play a unique role in bringing multidisciplinary talents -- in biology, physics, chemistry, computer sciences, and engineering -- to bear on major problems in the life and environmental sciences. Specifically, the laboratories utilize these talents to fulfill OHER's mission of exploring and mitigating the health and environmental effects of energy use, and of developing health and medical applications of nuclear energy-related phenomena. At Lawrence Berkeley Laboratory (LBL) support of this mission is evident across the spectrum of OHER-sponsored research, especially in the broad areas of genomics, structural biology, basic cell and molecular biology, carcinogenesis, energy and environment, applications to biotechnology, and molecular, nuclear and radiation medicine. These research areas are briefly described.

  13. Surface tension measurements with a smartphone

    Science.gov (United States)

    Goy, Nicolas-Alexandre; Denis, Zakari; Lavaud, Maxime; Grolleau, Adrian; Dufour, Nicolas; Deblais, Antoine; Delabre, Ulysse

    2017-11-01

    Smartphones are increasingly used in higher education and at university in mechanics, acoustics, and even thermodynamics as they offer a unique way to do simple science experiments. In this article, we show how smartphones can be used in fluid mechanics to measure surface tension of various liquids, which could help students understand the concept of surface tension through simple experiments.

  14. Marine Science

    African Journals Online (AJOL)

    A. formosa and P. verrucosa responded significantly to seasonal fluctuation in both solar radiation and sea surface temperature by regulating their ... types from the environmental pool. It is concluded that seasonal fluctuations in both solar ..... photoprotection in symbiotic dinoflagellates from reef-building corals. Marine ...

  15. An investigation into design of fair surfaces over irregular domains ...

    Indian Academy of Sciences (India)

    Design of fair surfaces over irregular domains is a fundamental problem in computer-aided geometric design (CAGD), and has applications in engineering sciences (in aircraft, automobile, ship science etc.). In the design of fair surfaces over irregular domains defined over scattered data, it was widely accepted till recently ...

  16. An investigation into design of fair surfaces over irregular domains ...

    Indian Academy of Sciences (India)

    neering sciences (in aircraft, automobile, ship science etc.). In the design of fair surfaces over ... In this paper, we discuss a method for construction of C1 piecewise polynomial parametric fair ... of applying the construction of piecewise polynomial parametric surfaces which interpolate prescribed 3 scattered data using ...

  17. Do Gender-Science Stereotypes Predict Science Identification and Science Career Aspirations among Undergraduate Science Majors?

    Science.gov (United States)

    Cundiff, Jessica L.; Vescio, Theresa K.; Loken, Eric; Lo, Lawrence

    2013-01-01

    The present research examined whether gender-science stereotypes were associated with science identification and, in turn, science career aspirations among women and men undergraduate science majors. More than 1,700 students enrolled in introductory science courses completed measures of gender-science stereotypes (implicit associations and…

  18. Surfacing Moves

    DEFF Research Database (Denmark)

    Lutz, Peter

    2013-01-01

    such as schedules, machines, and aging bodies. To this end, the article also experiments with ‘surfacing’ as an ethnographic heuristic for figuring these different ‘spatial-timings’. The article concludes that surfacing matters not only in senior home care but also in the field-desks of ethnographic analysis....

  19. Attack surfaces

    DEFF Research Database (Denmark)

    Gruschka, Nils; Jensen, Meiko

    2010-01-01

    The new paradigm of cloud computing poses severe security risks to its adopters. In order to cope with these risks, appropriate taxonomies and classification criteria for attacks on cloud computing are required. In this work-in-progress paper we present one such taxonomy based on the notion...... of attack surfaces of the cloud computing scenario participants....

  20. Science commons

    CERN Multimedia

    CERN. Geneva

    2007-01-01

    SCP: Creative Commons licensing for open access publishing, Open Access Law journal-author agreements for converting journals to open access, and the Scholar's Copyright Addendum Engine for retaining rights to self-archive in meaningful formats and locations for future re-use. More than 250 science and technology journals already publish under Creative Commons licensing while 35 law journals utilize the Open Access Law agreements. The Addendum Engine is a new tool created in partnership with SPARC and U.S. universities. View John Wilbanks's biography

  1. Science toys

    Science.gov (United States)

    Crease, Robert P.

    2009-01-01

    "I have a low boredom threshold," Tim Rowett explains, ushering in my son Alex and me. Rowett is a jovial, professorishlooking man with wire-rimmed glasses and a short, white beard. Alex and I have gone to his flat in Twickenham, on the edge of London, to see his collection of fun stuff - jokes, games, puzzles and other toys related to science. When I ask what they have in common, Rowett has a ready, if not illuminating, answer: "They're just things that make people go 'Wow!'."

  2. Science blogging

    CERN Document Server

    Wilcox, Christie

    2016-01-01

    Here is the essential how-to guide for communicating scientific research and discoveries online, ideal for journalists, researchers, and public information officers looking to reach a wide lay audience. Drawing on the cumulative experience of twenty-seven of the greatest minds in scientific communication, this invaluable handbook targets the specific questions and concerns of the scientific community, offering help in a wide range of digital areas, including blogging, creating podcasts, tweeting, and more. With step-by-step guidance and one-stop expertise, this is the book every scientist, science writer, and practitioner needs to approach the Wild West of the Web with knowledge and confidence.

  3. Science Night

    CERN Document Server

    2004-01-01

    Would it surprise you to know that you can measure the speed of light using chocolate and a microwave oven? If you're interested in this and in finding out much more, come along to the Museum of the History of Science on 3 and 4 July 2004, when dozens of companies, institutions, colleges and organizations will be running exhibits, shows, and displays on the theme of counting and measuring. CERN will be there with a display stand that includes two particle detectors. Full details are available from the Museum website at: http://www.lanuitdelascience.ch/

  4. Surface and interface effects in VLSI

    CERN Document Server

    Einspruch, Norman G

    1985-01-01

    VLSI Electronics Microstructure Science, Volume 10: Surface and Interface Effects in VLSI provides the advances made in the science of semiconductor surface and interface as they relate to electronics. This volume aims to provide a better understanding and control of surface and interface related properties. The book begins with an introductory chapter on the intimate link between interfaces and devices. The book is then divided into two parts. The first part covers the chemical and geometric structures of prototypical VLSI interfaces. Subjects detailed include, the technologically most import

  5. Big Science and Big Big Science

    Science.gov (United States)

    Marshall, Steve

    2012-01-01

    In his introduction to the science shows feature in "Primary Science" 115, Ian B. Dunne asks the question "Why have science shows?" He lists a host of very sound reasons, starting with because "science is fun" so why not engage and entertain, inspire, grab attention and encourage them to learn? He goes onto to state that: "Even in today's…

  6. Science as Entertainment and Entertainment Science.

    Science.gov (United States)

    Wassersug, Richard

    2002-01-01

    For many, doing science is entertaining, and engaging in a science activity for its entertainment value is a credible rationale. Drawing parallels between science and various forms of entertainment from sports to opera, highlights the value of "infotainment". Also mentions the risks associated with entertaining the public with science.…

  7. Surface modification of seawater desalination reverse osmosis membranes: Characterization studies & performance evaluation

    KAUST Repository

    Matin, Asif

    2014-06-01

    In this work we report surface modification of commercial reverse osmosis membranes by depositing ultrathin copolymer coatings, which could potentially enhance the biofouling resistance of RO membranes. Hydrophilic monomer hydroxyethyl methacrylate (HEMA) and a hydrophobic monomer, perfluorodecyl acrylate (PFDA) were copolymerized directly on the active layer of commercial aromatic polyamide reverse osmosis (RO) membranes using an initiated Chemical Vapor Deposition (iCVD) technique. Attenuated total reflective Fourier transform infrared spectra (ATR-FTIR) verified the successful modification of the membrane surfaces as a new FTIR adsorption band around 1730cm-1 corresponding to carbonyl groups in the copolymer film appeared after the deposition. X-ray Photoelectron spectroscopy (XPS) analysis also confirmed the presence of the copolymer film on the membrane surface by showing strong fluorine peaks emanating from the fluorinated alkyl side chains of the PFA molecules. Contact angle measurements with deionized water showed the modified membrane surfaces to be initially very hydrophobic but quickly assumed a hydrophilic character within few minutes. Atomic Force Microscopy (AFM) revealed that the deposited films were smooth and conformal as the surface topology of the underlying membrane surface remained virtually unchanged after the deposition. FESEM images of the top surface also showed that the typical ridge-and-valley structure associated with polyamide remained intact after the deposition. Short-term permeation tests using DI water and 2000ppm NaCl water showed that the deposited copolymer coatings had negligible effect on permeate water flux and salt rejection. © 2013 Elsevier B.V.

  8. Science kitsch and pop science: A reconnaissance.

    Science.gov (United States)

    Kaeser, Eduard

    2013-07-01

    Science kitsch? The combination of these two words rings like an oxymoron. Science - as the common saying has it - exposes, discovers, tells the truth; kitsch conceals, covers, lies. I think, this "shadow" of science deserves a specific scrutiny, not only because it reflects the altered place and role of science in contemporary "knowledge" society but also because it pinpoints the task of relocating science in the "multicultural" context of postmodernism, with its different epistemic claims. The genre of science kitsch may help to regain credit by working as a probe to detect false pretensions, explanatory exuberance and exaggerations in science.

  9. Mining Pribram in science and technology

    International Nuclear Information System (INIS)

    1984-01-01

    The Geomechanics session of the Symposium ''Mining Pribram in Science and Technology'' held from October 15 to 20, 1984 heard a total of 18 papers dealing with the effects of exploitation on the stability of the surrounding massif and surface, the protection of surface and deep mines, geophysical surveying, the measurement of deformations caUsed by undermining, the mathematical modelling of surface deformation and various measuring methods and methods of interpreting measured results. 4 papers are included into INIS. (B.S.)

  10. Enacting science

    Science.gov (United States)

    MacDonald, Anthony Leo

    My study examines the development of forms of knowing that arise when students engage in open-ended explorations involving self-directed design and building involving simple materials. It is grounded in an enactivist theoretical perspective on cognition which holds that the creation of action-thought processes for engaging the world is interwoven with the meanings that are constructed for these experiences. A dynamic conception of persons-acting-in-a-setting is fundamental to an enactivist view of cognition. How is understanding enacted in building activity? How does the shape of a problem emerge? How do students enact meaning and understanding when they experience a high degree of physical engagement in building things? What are some characteristics of an enactive learning/teaching environment? My research settings comprise a range of individual, group and classroom engagements of varying lengths over a three and one-half year period. The first research episode involved two grade eight students in an investigation of Paper Towels. The second four month engagement was in a grade nine science class that culminated in the building of a Solar House. The third grade ten episode involved a one month project to build a Mousetrap Powered Car. A fourth Invent a Machine project was conducted in two grade eight science classes taught by the teacher who participated in the Solar House project. Two students were present in three of the four projects. I interviewed one of these students upon completion of his high school physics courses. I found that building is a form of thinking which develops competency in managing complex practical tasks. A triadic relationship of exploration, planning and acting is present. Practical and procedural understandings emerge as students enter and re-enter self-directed problem settings. Thinking patterns depend on the kinds of materials chosen, the ways they are used, and on how students contextualize the problem. Classroom assessment

  11. Touch-Based Interaction Approach for Network Science Research and Visualization

    Science.gov (United States)

    2016-01-01

    wireless networks . The primary emulation tools used by ARL are the Extendable Mobile Ad hoc Network Emulator (EMANE)1 and the Common Open Research...Extendable Mobile Ad - hoc Network Emulator (EMANE), http://www.nrl.navy.mil/itd/ncs/products/emane 2. Common Open Research Emulator (CORE), http...or falsification of theoretical models, and characterization of protocols and algorithms for mobile wireless networks . It is used for a range of

  12. Supercomputational science

    CERN Document Server

    Wilson, S

    1990-01-01

    In contemporary research, the supercomputer now ranks, along with radio telescopes, particle accelerators and the other apparatus of "big science", as an expensive resource, which is nevertheless essential for state of the art research. Supercomputers are usually provided as shar.ed central facilities. However, unlike, telescopes and accelerators, they are find a wide range of applications which extends across a broad spectrum of research activity. The difference in performance between a "good" and a "bad" computer program on a traditional serial computer may be a factor of two or three, but on a contemporary supercomputer it can easily be a factor of one hundred or even more! Furthermore, this factor is likely to increase with future generations of machines. In keeping with the large capital and recurrent costs of these machines, it is appropriate to devote effort to training and familiarization so that supercomputers are employed to best effect. This volume records the lectures delivered at a Summer School ...

  13. Iron oxide surfaces

    Science.gov (United States)

    Parkinson, Gareth S.

    2016-03-01

    The current status of knowledge regarding the surfaces of the iron oxides, magnetite (Fe3O4), maghemite (γ-Fe2O3), haematite (α-Fe2O3), and wüstite (Fe1-xO) is reviewed. The paper starts with a summary of applications where iron oxide surfaces play a major role, including corrosion, catalysis, spintronics, magnetic nanoparticles (MNPs), biomedicine, photoelectrochemical water splitting and groundwater remediation. The bulk structure and properties are then briefly presented; each compound is based on a close-packed anion lattice, with a different distribution and oxidation state of the Fe cations in interstitial sites. The bulk defect chemistry is dominated by cation vacancies and interstitials (not oxygen vacancies) and this provides the context to understand iron oxide surfaces, which represent the front line in reduction and oxidation processes. Fe diffuses in and out from the bulk in response to the O2 chemical potential, forming sometimes complex intermediate phases at the surface. For example, α-Fe2O3 adopts Fe3O4-like surfaces in reducing conditions, and Fe3O4 adopts Fe1-xO-like structures in further reducing conditions still. It is argued that known bulk defect structures are an excellent starting point in building models for iron oxide surfaces. The atomic-scale structure of the low-index surfaces of iron oxides is the major focus of this review. Fe3O4 is the most studied iron oxide in surface science, primarily because its stability range corresponds nicely to the ultra-high vacuum environment. It is also an electrical conductor, which makes it straightforward to study with the most commonly used surface science methods such as photoemission spectroscopies (XPS, UPS) and scanning tunneling microscopy (STM). The impact of the surfaces on the measurement of bulk properties such as magnetism, the Verwey transition and the (predicted) half-metallicity is discussed. The best understood iron oxide surface at present is probably Fe3O4(100); the structure is

  14. Reproductive health issues emanating from the Children's Act No ...

    African Journals Online (AJOL)

    The study took as its point of departure the Children's Act No, 38 of 2005 implemented in 2010, which aims to promote the preservation and strengthening of families and to give effect to the rights of children as enshrined in the Constitution of the Republic of South Africa. When the Act was introduced certain segments of ...

  15. Emanation of Formalistic Criticism Components in Nima Yushigs' "Khabe Zemestani"

    Directory of Open Access Journals (Sweden)

    Khalilollahi Shala

    2017-02-01

    Full Text Available Formalism is an approach and critical theory in which, form and structure are its essential elements of aesthetic considerations. Coleridge believes that form is a function of considered thoughts in poetry. From his point of view, form is achieved from inside the poem and by its' subject necessity. Nima abstains to directly explain his thoughts and emotions in "Khabe Zemestani" poem and symbolically proceeds to state his status and social events. The purpose of this article is the formalistic analysis of "Khabe Zemestani" poem from Nima Yushige. The issue of this paper is to explain the meaning and content of the poem "Khabe Zemestani" in the form and structure way, which has been done in library and content analysis method. The result of this analysis indicates that the most important motif in this poem is based on contrasts between "life and death", "sleep and wakefulness" and "neglect and soberness". Therefore, the main act of poem is based on divergence. In fact, contradictions, paradoxes and symbols in the poetry of Nima, have portrayed the main characters' condition and the social palpitation of his era with the help of nature elements.

  16. [After ten years of AIDS, a vision emanating from feminism].

    Science.gov (United States)

    Liguori, A L

    1991-01-01

    AIDS and the economic crisis in Mexico are threatening the epidemiologic transition in which infectious diseases ceased to be the only major cause of death and chronic degenerative diseases began to account for a growing proportion of deaths. Many factors combined to produce the sexual, gay, and women's liberation movements beginning in the 1970s. At the beginning of the feminist movement, women proposed different kinds of interpersonal relations both between women and with men. Women together realized their rights to control their own bodies, to sexual enjoyment, to abortion, and to free themselves of feelings of shame and guilt. The weight of moral pressures was lessened and the personal desires of the woman assumed a greater role in selection of sexual partners. Conservative forces grew stronger in the 1980s, and the proliferation of sexually transmitted diseases began to imperil the sexual revolution. But these setbacks were minor compared to AIDS. Now, 10 years after its appearance, it is clear that AIDS is not limited to homosexual men. The number of cases in Mexico increased from none 10 years ago to some 10,000 estimated cases reported and unreported today. 1/6 of the cases are in women. Many women and heterosexuals felt immune from AIDS in the beginning, and some still do, but many more have become aware of the danger. Women now fear contracting AIDS, but they also fear confronting their partners to suggest that they use condoms. Denial may play a role, but deeply rooted cultural factors that women may recognize but fee powerless to change may also be at play. Many women over 30 have difficulty taking the initiative in sexual matters. They are embarrassed to buy condoms and even more embarrassed to propose their use. They imagine that men will consider them "loose" if they carry condoms. Mexican women are poorly prepared to tell their men explicitly what they want sexually, and Mexican men are also poorly equipped to ask what women want, accustomed as they are to exercising sexuality exclusively to satisfy their own needs. The entire problem of condom use is related to ethical-moral and ideological factors and to broader attitudes toward knowledge. Those with more rational orientations see AIDS as a disease rather than a divine punishment and can more easily accept condom use as a preventive.

  17. Mars Science Laboratory Mission and Science Investigation

    Science.gov (United States)

    Grotzinger, John P.; Crisp, Joy; Vasavada, Ashwin R.; Anderson, Robert C.; Baker, Charles J.; Barry, Robert; Blake, David F.; Conrad, Pamela; Edgett, Kenneth S.; Ferdowski, Bobak; Gellert, Ralf; Gilbert, John B.; Golombek, Matt; Gómez-Elvira, Javier; Hassler, Donald M.; Jandura, Louise; Litvak, Maxim; Mahaffy, Paul; Maki, Justin; Meyer, Michael; Malin, Michael C.; Mitrofanov, Igor; Simmonds, John J.; Vaniman, David; Welch, Richard V.; Wiens, Roger C.

    2012-09-01

    -bearing strata, separated by an unconformity from overlying likely anhydrous strata; the landing ellipse is characterized by a mixture of alluvial fan and high thermal inertia/high albedo stratified deposits; and a number of stratigraphically/geomorphically distinct fluvial features. Samples of the crater wall and rim rock, and more recent to currently active surface materials also may be studied. Gale has a well-defined regional context and strong evidence for a progression through multiple potentially habitable environments. These environments are represented by a stratigraphic record of extraordinary extent, and insure preservation of a rich record of the environmental history of early Mars. The interior mountain of Gale Crater has been informally designated at Mount Sharp, in honor of the pioneering planetary scientist Robert Sharp. The major subsystems of the MSL Project consist of a single rover (with science payload), a Multi-Mission Radioisotope Thermoelectric Generator, an Earth-Mars cruise stage, an entry, descent, and landing system, a launch vehicle, and the mission operations and ground data systems. The primary communication path for downlink is relay through the Mars Reconnaissance Orbiter. The primary path for uplink to the rover is Direct-from-Earth. The secondary paths for downlink are Direct-to-Earth and relay through the Mars Odyssey orbiter. Curiosity is a scaled version of the 6-wheel drive, 4-wheel steering, rocker bogie system from the Mars Exploration Rovers (MER) Spirit and Opportunity and the Mars Pathfinder Sojourner. Like Spirit and Opportunity, Curiosity offers three primary modes of navigation: blind-drive, visual odometry, and visual odometry with hazard avoidance. Creation of terrain maps based on HiRISE (High Resolution Imaging Science Experiment) and other remote sensing data were used to conduct simulated driving with Curiosity in these various modes, and allowed selection of the Gale crater landing site which requires climbing the base of a

  18. Developments in clinical food and nutrition science in Indonesia.

    Science.gov (United States)

    Lukito, Widjaja; Wibowo, Lindawati; Wahlqvist, Mark L

    2016-12-01

    Indonesia, as a major population in the Asia Pacific region, threatened with food and health insecurity through climate change and rapid economic development, faces the challenge to build capacity among its science-based food and health professionals and institutions. The nutrition research agenda is now being more actively set within the region, rather than by external imposition. A series of papers emanating from a new generation of public health and clinical nutrition scientists is reported in this issue of APJCN. It draws attention to the importance of food patterns and background culture as contributors to the failure of the nutrient rather than a food, food system and socio-ecological approach to solve the region's intransigent nutritionally-related health problems. New understandings of human eco-social biology are providing opportunities to accelerate the resolution of these problems. The challenge is to transform the food-health construct from one which is not sufficiently concerned about the precarious state of ecologically dysfunctional health and its nutrient market drivers to one which strives for more sustainable and affordable solutions. The present reports address a range of options to these ends.

  19. Team science for science communication.

    Science.gov (United States)

    Wong-Parodi, Gabrielle; Strauss, Benjamin H

    2014-09-16

    Natural scientists from Climate Central and social scientists from Carnegie Mellon University collaborated to develop science communications aimed at presenting personalized coastal flood risk information to the public. We encountered four main challenges: agreeing on goals; balancing complexity and simplicity; relying on data, not intuition; and negotiating external pressures. Each challenge demanded its own approach. We navigated agreement on goals through intensive internal communication early on in the project. We balanced complexity and simplicity through evaluation of communication materials for user understanding and scientific content. Early user test results that overturned some of our intuitions strengthened our commitment to testing communication elements whenever possible. Finally, we did our best to negotiate external pressures through regular internal communication and willingness to compromise.

  20. Muon science experiments

    International Nuclear Information System (INIS)

    Nishiyama, Kusuo

    2001-01-01

    Muon experimental facility is in the planning stage as a part of the high intensity proton accelerator project of KEK and JAERI. Outline of muon experimental facility and physical experiments are described. There are five kinds of beam channels such as superconducting solenoid, surface muon, ultra-slow muon, high momentum muon and ultra-high intensity muon. The μSR method by positive electric charge muon makes possible to study antiferromagnet, spin glass, muon spin high-frequency resonance and paramagnetic shift. The positive electric charge muon is one of hydrogen isotopes. Accordingly, the quantum diffusion experiments of metals, semiconductor and insulator are carried out by the isotope effect. Development of muon catalyzed fusion by negative electric charge muon is one of problems of this facility. It can be applied to chemical reaction and non-destructive analysis. An illustration of the history of muon science is shown. (S.Y.)