WorldWideScience

Sample records for hydrogen depth profiling

  1. Positron depth profiling of the structural and electronic structure transformations of hydrogenated Mg-based thin films

    NARCIS (Netherlands)

    Eijt, S.W.H.; Kind, R.; Singh, S.; Schut, H.; Legerstee, W.J.; Hendrikx, R.W.A.; Svetchnikov, V.L.; Westerwaal, R.J.; Dam, B.

    2009-01-01

    We report positron depth-profiling studies on the hydrogen sorption behavior and phase evolution of Mg-based thin films. We show that the main changes in the depth profiles resulting from the hydrogenation to the respective metal hydrides are related to a clear broadening in the observed electron

  2. ERDA. Technique for hydrogen content and depth profile in thin film metal hydride

    Energy Technology Data Exchange (ETDEWEB)

    Jain, I.P.; Jain, Ankur; Jain, Pragya [Rajasthan Univ., Jaipur (India). Centre for Non Conventional Energy Resources

    2010-07-01

    The use of thin films for hydrogen storage has become very important as the main process of absorption and desorption of hydrogen takes place on the surface of the material. The incorporation of hydrogen into thin film form is relatively new field of research and provides an opportunity to examine a number of unusual properties, which are not visible in the bulk hydrides. Considerable amount of work has been done in our laboratory to investigate hydrogen absorption mechanism in FeTi, LaNi, and MmNi{sub 4.5}Al{sub 0.5} thin film metal hydrides. Over the past few decades thin films are analyzed using ion beam analysis techniques where an energetic incident ion provides depth information on the basis of the energy lost by it and the creation of possible secondary particles in the sample. One of the most commonly used such techniques is Rutherford Backscattering (RBS) which makes use of {alpha} particles of few MeV energy and is based on the principle of elastic scattering. One of the main drawbacks of RBS is its poor sensitivity for light elements present in a heavier matrix. Hence hydrogen cannot be detected using RBS as backscattering of ions from hydrogen is not possible. The limitations of RBS are overcome by another technique, Elastic Recoil Detection Analysis (ERDA), in which the yield and energy of particle ejected out of thin film sample under swift heavy ion beam irradiation is detected giving the quantitative information concerning the depth distribution of light elements in a sample. In the present work ERDA technique is being presented with its principle, design, working and application for hydrogen content and depth profile in thin film hydride. (orig.)

  3. Hydrogen in oxygen-free, phosphorus-doped copper - Charging techniques, hydrogen contents and modelling of hydrogen diffusion and depth profile

    Energy Technology Data Exchange (ETDEWEB)

    Martinsson, Aasa [Swerea KIMAB, Kista (Sweden); Sandstroem, Rolf [Swerea KIMAB, Kista (Sweden); Div. of Materials Science and Engineering, KTH Royal Institute of Technology, Stockholm (Sweden); Lilja, Christina [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    2013-01-15

    In Sweden spent nuclear fuel is planned to be disposed of by encapsulating in cast iron inserts protected by a copper shell. The copper can be exposed to hydrogen released during corrosion processes in the inserts. If the hydrogen is taken up by the copper, it could lead to hydrogen embrittlement. Specimens from oxygen-free copper have been hydrogen charged using two different methods. The purpose was to investigate how hydrogen could be introduced into copper in a controlled way. The thermal charging method resulted in a reduction of the initial hydrogen content. After electrochemical charging of cylindrical specimens, the measured hydrogen content was 2.6 wt. ppm which should compared with 0.6 wt. ppm before charging. The retained hydrogen after two weeks was reduced by nearly 40%. Recently the paper 'Hydrogen depth profile in phosphorus-doped, oxygen-free copper after cathodic charging' (Martinsson and Sandstrom, 2012) has been published. The paper describes experimental results for bulk specimens as well as presenting a model. Almost all the hydrogen is found to be located less than 100 {mu}m from the surface. This model is used to interpret the experimental results on foils in the present report. Since the model is fully based on fundamental equations, it can be used to analyse what happens in new situations. In this report the effect of the charging intensity, the grain size, the critical nucleus size for hydrogen bubble formation as well as the charging time are analysed.

  4. Applications of positron depth profiling

    Energy Technology Data Exchange (ETDEWEB)

    Hakvoort, R.A.

    1993-12-23

    In this thesis some contributions of the positron-depth profiling technique to materials science have been described. Following studies are carried out: Positron-annihilation measurements on neon-implanted steel; Void creation in silicon by helium implantation; Density of vacancy-type defects present in amorphous silicon prepared by ion implantation; Measurements of other types of amorphous silicon; Epitaxial cobalt disilicide prepared by cobalt outdiffusion. Positron-annihilation experiments on low-pressure CVD silicon-nitride films. (orig./MM).

  5. Hydrogen analysis depth calibration by CORTEO Monte-Carlo simulation

    Energy Technology Data Exchange (ETDEWEB)

    Moser, M., E-mail: marcus.moser@unibw.de [Universität der Bundeswehr München, Institut für Angewandte Physik und Messtechnik LRT2, Fakultät für Luft- und Raumfahrttechnik, 85577 Neubiberg (Germany); Reichart, P.; Bergmaier, A.; Greubel, C. [Universität der Bundeswehr München, Institut für Angewandte Physik und Messtechnik LRT2, Fakultät für Luft- und Raumfahrttechnik, 85577 Neubiberg (Germany); Schiettekatte, F. [Université de Montréal, Département de Physique, Montréal, QC H3C 3J7 (Canada); Dollinger, G., E-mail: guenther.dollinger@unibw.de [Universität der Bundeswehr München, Institut für Angewandte Physik und Messtechnik LRT2, Fakultät für Luft- und Raumfahrttechnik, 85577 Neubiberg (Germany)

    2016-03-15

    Hydrogen imaging with sub-μm lateral resolution and sub-ppm sensitivity has become possible with coincident proton–proton (pp) scattering analysis (Reichart et al., 2004). Depth information is evaluated from the energy sum signal with respect to energy loss of both protons on their path through the sample. In first order, there is no angular dependence due to elastic scattering. In second order, a path length effect due to different energy loss on the paths of the protons causes an angular dependence of the energy sum. Therefore, the energy sum signal has to be de-convoluted depending on the matrix composition, i.e. mainly the atomic number Z, in order to get a depth calibrated hydrogen profile. Although the path effect can be calculated analytically in first order, multiple scattering effects lead to significant deviations in the depth profile. Hence, in our new approach, we use the CORTEO Monte-Carlo code (Schiettekatte, 2008) in order to calculate the depth of a coincidence event depending on the scattering angle. The code takes individual detector geometry into account. In this paper we show, that the code correctly reproduces measured pp-scattering energy spectra with roughness effects considered. With more than 100 μm thick Mylar-sandwich targets (Si, Fe, Ge) we demonstrate the deconvolution of the energy spectra on our current multistrip detector at the microprobe SNAKE at the Munich tandem accelerator lab. As a result, hydrogen profiles can be evaluated with an accuracy in depth of about 1% of the sample thickness.

  6. Depth profiling of aluminium metal using slow positron beam ...

    African Journals Online (AJOL)

    Slow positron beam Doppler-broadening technique was used to study depth profiling of aluminium metals sample. The variation of the line-shape parameters with incident positron energy was studied. Also, the depth profile of the S parameter was investigated. The positron implantation profile and backscattering fraction for ...

  7. Interpreting Repeated Temperature-Depth Profiles for Groundwater Flow

    Science.gov (United States)

    Bense, Victor F.; Kurylyk, Barret L.; van Daal, Jonathan; van der Ploeg, Martine J.; Carey, Sean K.

    2017-10-01

    Temperature can be used to trace groundwater flows due to thermal disturbances of subsurface advection. Prior hydrogeological studies that have used temperature-depth profiles to estimate vertical groundwater fluxes have either ignored the influence of climate change by employing steady-state analytical solutions or applied transient techniques to study temperature-depth profiles recorded at only a single point in time. Transient analyses of a single profile are predicated on the accurate determination of an unknown profile at some time in the past to form the initial condition. In this study, we use both analytical solutions and a numerical model to demonstrate that boreholes with temperature-depth profiles recorded at multiple times can be analyzed to either overcome the uncertainty associated with estimating unknown initial conditions or to form an additional check for the profile fitting. We further illustrate that the common approach of assuming a linear initial temperature-depth profile can result in significant errors for groundwater flux estimates. Profiles obtained from a borehole in the Veluwe area, Netherlands in both 1978 and 2016 are analyzed for an illustrative example. Since many temperature-depth profiles were collected in the late 1970s and 1980s, these previously profiled boreholes represent a significant and underexploited opportunity to obtain repeat measurements that can be used for similar analyses at other sites around the world.

  8. Depth resolution and preferential sputtering in depth profiling of sharp interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, S. [Max Planck Institute for Intelligent Systems (formerly MPI for Metals Research), Heisenbergstrasse 3, D-70569 Stuttgart (Germany); Han, Y.S. [Department of Physics, Shantou University, 243 Daxue Road, Shantou, 515063 Guangdong (China); Wang, J.Y., E-mail: wangjy@stu.edu.cn [Department of Physics, Shantou University, 243 Daxue Road, Shantou, 515063 Guangdong (China)

    2017-07-15

    Highlights: • Interfacial depth resolution from MRI model depends on sputtering rate differences. • Depth resolution critically depends on the dominance of roughness or atomic mixing. • True (depth scale) and apparent (time scale) depth resolutions are different. • Average sputtering rate approximately yields true from apparent depth resolution. • Profiles by SIMS and XPS are different but similar to surface concentrations. - Abstract: The influence of preferential sputtering on depth resolution of sputter depth profiles is studied for different sputtering rates of the two components at an A/B interface. Surface concentration and intensity depth profiles on both the sputtering time scale (as measured) and the depth scale are obtained by calculations with an extended Mixing-Roughness-Information depth (MRI)-model. The results show a clear difference for the two extreme cases (a) preponderant roughness and (b) preponderant atomic mixing. In case (a), the interface width on the time scale (Δt(16–84%)) increases with preferential sputtering if the faster sputtering component is on top of the slower sputtering component, but the true resolution on the depth scale (Δz(16–84%)) stays constant. In case (b), the interface width on the time scale stays constant but the true resolution on the depth scale varies with preferential sputtering. For similar order of magnitude of the atomic mixing and the roughness parameters, a transition state between the two extremes is obtained. While the normalized intensity profile of SIMS represents that of the surface concentration, an additional broadening effect is encountered in XPS or AES by the influence of the mean electron escape depth which may even cause an additional matrix effect at the interface.

  9. An optical fiber expendable seawater temperature/depth profile sensor

    Science.gov (United States)

    Zhao, Qiang; Chen, Shizhe; Zhang, Keke; Yan, Xingkui; Yang, Xianglong; Bai, Xuejiao; Liu, Shixuan

    2017-10-01

    Marine expendable temperature/depth profiler (XBT) is a disposable measuring instrument which can obtain temperature/depth profile data quickly in large area waters and mainly used for marine surveys, scientific research, military application. The temperature measuring device is a thermistor in the conventional XBT probe (CXBT)and the depth data is only a calculated value by speed and time depth calculation formula which is not an accurate measurement result. Firstly, an optical fiber expendable temperature/depth sensor based on the FBG-LPG cascaded structure is proposed to solve the problems of the CXBT, namely the use of LPG and FBG were used to detect the water temperature and depth, respectively. Secondly, the fiber end reflective mirror is used to simplify optical cascade structure and optimize the system performance. Finally, the optical path is designed and optimized using the reflective optical fiber end mirror. The experimental results show that the sensitivity of temperature and depth sensing based on FBG-LPG cascade structure is about 0.0030C and 0.1%F.S. respectively, which can meet the requirements of the sea water temperature/depth observation. The reflectivity of reflection mirror is in the range from 48.8% to 72.5%, the resonant peak of FBG and LPG are reasonable and the whole spectrum are suitable for demodulation. Through research on the optical fiber XBT (FXBT), the direct measurement of deep-sea temperature/depth profile data can be obtained simultaneously, quickly and accurately. The FXBT is a new all-optical seawater temperature/depth sensor, which has important academic value and broad application prospect and is expected to replace the CXBT in the future.

  10. Molecular depth profiling of organic and biological materials

    Energy Technology Data Exchange (ETDEWEB)

    Fletcher, John S. [Surface Analysis Research Centre, School of Chemical Engineering and Analytical Science, University of Manchester, Manchester M60 1QD (United Kingdom)]. E-mail: John.Fletcher@manchester.ac.uk; Conlan, Xavier A. [Surface Analysis Research Centre, School of Chemical Engineering and Analytical Science, University of Manchester, Manchester M60 1QD (United Kingdom); Lockyer, Nicholas P. [Surface Analysis Research Centre, School of Chemical Engineering and Analytical Science, University of Manchester, Manchester M60 1QD (United Kingdom); Vickerman, John C. [Surface Analysis Research Centre, School of Chemical Engineering and Analytical Science, University of Manchester, Manchester M60 1QD (United Kingdom)

    2006-07-30

    Atomic depth profiling using secondary ion mass spectrometry, SIMS, is common in the field micro-electronics; however, the generation of molecular information as a function of sample depth is difficult due to the accumulation of damage both on and beneath the sample surface. The introduction of polyatomic ion beams such as SF{sub 5} and C{sub 60} have raised the possibility of overcoming this problem as they deposit the majority of their energy in the upper surface of the sample resulting in increased sputter yields but with a complimentary reduction in sub-surface damage accumulation. In this paper we report the depth profile analysis of the bio-polymer polycaprolactone, PCL, using the polyatomic ions Au{sub 3}{sup +} and C{sub 60}{sup +} and the monoatomic Au{sup +}. Results are compared to recent analysis of a similar sample using SF{sub 5}{sup +}. C{sub 60}{sup +} depth profiling of cellulose is also demonstrated, an experiment that has been reported as unsuccessful when attempted with SF{sub 5}{sup +} implications for biological analysis are discussed.

  11. Depth profiles and free volume in aircraft primer films

    Science.gov (United States)

    Van Horn, J. D.; Chen, H.; Jean, Y. C.; Zhang, W.; Jaworowski, M. R.

    2015-06-01

    Positron annihilation lifetime spectroscopy (PALS) and associated techniques provide non-destructive methods to study the free volume inside polymeric materials, and to study material characteristics over a depth profile. Cast free films of organic- or aqueous-based, non-chromated aerospace primers, when cured for about one week, had very different water vapour transport (through-plane) behaviour. In addition, both types of primer films showed strong anisotropic behaviour in in-plane versus through-plane water vapour transport rates. We report the differences between the organic- and aqueous-based aircraft primer films samples and their surface depth profiles. In bulk PALS measurements, an aged, organic-based film exhibited typical lifetimes and intensities for a particulate-containing polymer film on both faces. In contrast, aqueous-based films exhibited face oriented-dependent differences. In all aqueous- based samples, the I3 value of the back of the sample was smaller. The primer film samples were also evaluated with mono-energetic positron beam techniques to generate depth profile information. The heterogeneity in the samples was verified by Doppler broadening of energy spectroscopy (DBES). A model for the differences in the faces of the films, and their layered structure is discussed.

  12. Pulsed photothermal depth profiling of tattoos undergoing laser removal treatment

    Science.gov (United States)

    Milanic, Matija; Majaron, Boris

    2012-02-01

    Pulsed photothermal radiometry (PPTR) allows noninvasive determination of temperature depth profiles induced by pulsed laser irradiation of strongly scattering biological tissues and organs, including human skin. In present study, we evaluate the potential of this technique for investigational characterization and possibly quantitative evaluation of laser tattoo removal. The study involved 5 healthy volunteers (3 males, 2 females), age 20-30 years, undergoing tattoo removal treatment using a Q-switched Nd:YAG laser. There were four measurement and treatment sessions in total, separated by 2-3 months. Prior to each treatment, PPTR measurements were performed on several tattoo sites and one nearby healthy site in each patient, using a 5 ms Nd:YAG laser at low radiant exposure values and a dedicated radiometric setup. The laser-induced temperature profiles were then reconstructed by applying a custom numerical code. In addition, each tatoo site was documented with a digital camera and measured with a custom colorimetric system (in tristimulus color space), providing an objective evaluation of the therapeutic efficacy to be correlated with our PPTR results. The results show that the laser-induced temperature profile in untreated tattoos is invariably located at a subsurface depth of 300 μm. In tattoo sites that responded well to laser therapy, a significant drop of the temperature peak was observed in the profiles obtained from PPTR record. In several sites that appeared less responsive, as evidenced by colorimetric data, a progressive shift of the temperature profile deeper into the dermis was observed over the course of consecutive laser treatments, indicating that the laser tattoo removal was efficient.

  13. Grain size dependence of penetration depth of hydrogen injection into polycrystalline graphite by molecular simulation

    Science.gov (United States)

    Saito, Seiki; Ito, Atsushi M.; Takayama, Arimichi; Nakamura, Hiroaki

    2014-11-01

    Many different carbon materials are developed for diverse applications for industrial and scientific uses. It is known that the amount of hydrogen retained in carbon materials under plasma irradiation strongly depends on the structural characteristics of the material, such as grain size. To clarify the cause of the difference in the amount of hydrogen retained in different carbon materials, hydrogen atom injection into polycrystalline graphite is investigated on the atomic scale by a hybrid simulation technique consisting of binary-collision-approximation-based simulation and molecular dynamics simulation. Then, the incident energy and grain size dependences of the penetration profile of incident hydrogen atoms are carefully investigated.

  14. Chemical depth profiling of photovoltaic backsheets after accelerated laboratory weathering

    Science.gov (United States)

    Lin, Chiao-Chi; Krommenhoek, Peter J.; Watson, Stephanie S.; Gu, Xiaohong

    2014-10-01

    Polymeric multilayer backsheets provide protection for the backside of photovoltaic (PV) module from the damage of moisture and ultraviolet (UV). Due to the nature of multilayer films, certain material property characterization of a backsheet could only be studied by examining its cross-section parallel to the thickness direction of the film. In this study, commercial PPE (polyethylene terephthalate (PET)/PET/ethylene vinyl acetate (EVA)) backsheet films were aged on the NIST (National Institute of Standards and Technology) SPHERE (Simulated Photodegradation via High Energy Radiant Exposure) with UV irradiance at 170 W/m2 (300 nm to 400 nm) under accelerated weathering conditions of 85°C and two relative humidity (R.H.) levels of 5% (low) and 60% (high). Cryo-microtomy was used to obtain cross-sectional PPE samples with a flat surface parallel to the thickness direction, and chemical depth profiling of multilayers was conducted by Raman microscopic mapping. Atomic force microscopy with peak force tapping mode was used complementarily for cross-sectional imaging. The results revealed that the PPE backsheet films were comprised of five main layers, including pigmented-PET, core PET, inner EVA, pigmented-EVA and outer EVA, along with their interfacial regions and two adhesive layers. UV and moisture degradation on the outer pigmented PET layer was clearly observed; while the damage on the core PET layer was less significance, indicating that the outer pigmented PET layer effectively reduced the damage from UV. In high R.H. exposure, both adhesive layers were severely deteriorated. It was found that the EVA layers were susceptible to moisture at elevated temperature, especially for the pigmented-EVA. Based on the results of accelerated weathering, this depth profiling study brings new understanding to the mechanisms of failure observed in polymeric multilayer backsheets during field exposure.

  15. PENETRATION DEPTH OF 0.5-3-KEV ELECTRONS IN SOLID HYDROGEN AND DEUTERIUM

    DEFF Research Database (Denmark)

    Schou, Jørgen; Sørensen, H.

    1978-01-01

    The mirror-substrate method was used for measuring the penetration depth of 0. 5-3-keV electrons in solid hydrogen and deuterium. The penetration depth was found to be 0. 53 multiplied by 10**1**8E**1**. **7**2 molecules/cm**2 with the energy given in keV. There was satisfactory agreement...... with other data. The measurements also showed that the escape depth for true secondary electrons from solid deuterium is less than 50 A, which agrees well with the small values for the secondary-electron-emission coefficient found for solid deuterium. Results were furthermore obtained for the electron...

  16. Sub-nanometer resolution XPS depth profiling: Sensing of atoms

    Energy Technology Data Exchange (ETDEWEB)

    Szklarczyk, Marek, E-mail: szklarcz@chem.uw.edu.pl [Faculty of Chemistry, University of Warsaw, ul. Pasteura 1, 02-093 Warsaw (Poland); Shim-Pol, ul. Lubomirskiego 5, 05-080 Izabelin (Poland); Macak, Karol; Roberts, Adam J. [Kratos Analytical Ltd, Wharfside, Trafford Wharf Road, Manchester, M17 1GP (United Kingdom); Takahashi, Kazuhiro [Kratos XPS Section, Shimadzu Corp., 380-1 Horiyamashita, Hadano, Kanagawa 259-1304 (Japan); Hutton, Simon [Kratos Analytical Ltd, Wharfside, Trafford Wharf Road, Manchester, M17 1GP (United Kingdom); Głaszczka, Rafał [Shim-Pol, ul. Lubomirskiego 5, 05-080 Izabelin (Poland); Blomfield, Christopher [Kratos Analytical Ltd, Wharfside, Trafford Wharf Road, Manchester, M17 1GP (United Kingdom)

    2017-07-31

    Highlights: • Angle resolved photoelectron depth profiling of nano thin films. • Sensing atomic position in SAM films. • Detection of direction position of adsorbed molecules. - Abstract: The development of a method capable of distinguishing a single atom in a single molecule is important in many fields. The results reported herein demonstrate sub-nanometer resolution for angularly resolved X-ray photoelectron spectroscopy (ARXPS). This is made possible by the incorporation of a Maximum Entropy Method (MEM) model, which utilize density corrected electronic emission factors to the X-ray photoelectron spectroscopy (XPS) experimental results. In this paper we report on the comparison between experimental ARXPS results and reconstructed for both inorganic and organic thin film samples. Unexpected deviations between experimental data and calculated points are explained by the inaccuracy of the constants and standards used for the calculation, e.g. emission factors, scattering intensity and atomic density through the studied thickness. The positions of iron, nitrogen and fluorine atoms were determined in the molecules of the studied self-assembled monolayers. It has been shown that reconstruction of real spectroscopic data with 0.2 nm resolution is possible.

  17. Depth

    Science.gov (United States)

    Koenderink, Jan J; van Doorn, Andrea J; Wagemans, Johan

    2011-01-01

    Depth is the feeling of remoteness, or separateness, that accompanies awareness in human modalities like vision and audition. In specific cases depths can be graded on an ordinal scale, or even measured quantitatively on an interval scale. In the case of pictorial vision this is complicated by the fact that human observers often appear to apply mental transformations that involve depths in distinct visual directions. This implies that a comparison of empirically determined depths between observers involves pictorial space as an integral entity, whereas comparing pictorial depths as such is meaningless. We describe the formal structure of pictorial space purely in the phenomenological domain, without taking recourse to the theories of optics which properly apply to physical space—a distinct ontological domain. We introduce a number of general ways to design and implement methods of geodesy in pictorial space, and discuss some basic problems associated with such measurements. We deal mainly with conceptual issues. PMID:23145244

  18. Depth Profile Analysis of Amorphous Silicon Thin Film Solar Cells by Pulsed Radiofrequency Glow Discharge Time of Flight Mass Spectrometry

    Science.gov (United States)

    Alvarez-Toral, Aitor; Sanchez, Pascal; Menéndez, Armando; Pereiro, Rosario; Sanz-Medel, Alfredo; Fernández, Beatriz

    2015-02-01

    Among the different solar cell technologies, amorphous silicon (a-Si:H) thin film solar cells (TFSCs) are today very promising and, so, TFSCs analytical characterization for quality control issues is increasingly demanding. In this line, depth profile analysis of a-Si:H TFSCs on steel substrate has been investigated by using pulsed radiofrequency glow discharge-time of flight mass spectrometry (rf-PGD-TOFMS). First, to discriminate potential polyatomic interferences for several analytes (e.g., 28Si+, 31P+, and 16O+) appropriate time positions along the GD pulse profile were selected. A multi-matrix calibration approach, using homogeneous certified reference materials without hydrogen as well as coated laboratory-made standards containing hydrogen, was employed for the methodological calibration. Different calibration strategies (in terms of time interval selection on the pulse profile within the afterglow region) have been compared, searching for optimal calibration graphs correlation. Results showed that reliable and fast quantitative depth profile analysis of a-Si:H TFSCs by rf-PGD-TOFMS can be achieved.

  19. Simulation of nitrogen concentration depth profiles in low temperature nitrided stainless steel

    DEFF Research Database (Denmark)

    Christiansen, Thomas; Dahl, Kristian Vinter; Somers, Marcel A. J.

    2006-01-01

    A numerical model is presented, which simulates nitrogen concentration-depth profiles as obtained with low temperature gaseous nitriding of stainless steel. The evolution of the calculated nitrogen concentration-depth profiles is compared with experimental nitriding kinetics. It is shown...

  20. Measuring depth profiles of residual stress with Raman spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Enloe, W.S.; Sparks, R.G.; Paesler, M.A.

    1988-12-01

    Knowledge of the variation of residual stress is a very important factor in understanding the properties of machined surfaces. The nature of the residual stress can determine a part`s susceptibility to wear deformation, and cracking. Raman spectroscopy is known to be a very useful technique for measuring residual stress in many materials. These measurements are routinely made with a lateral resolution of 1{mu}m and an accuracy of 0.1 kbar. The variation of stress with depth; however, has not received much attention in the past. A novel technique has been developed that allows quantitative measurement of the variation of the residual stress with depth with an accuracy of 10nm in the z direction. Qualitative techniques for determining whether the stress is varying with depth are presented. It is also demonstrated that when the stress is changing over the volume sampled, errors can be introduced if the variation of the stress with depth is ignored. Computer aided data analysis is used to determine the depth dependence of the residual stress.

  1. Depth profile of In and As in Si measured by RBS with He and C ions

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Q.; Fang, Z. [Newcastle Univ., NSW (Australia). Dept. of Physics; Ophel, T.R. [Australian National Univ., Canberra, ACT (Australia). Dept. of Nuclear Physics

    1993-12-31

    The depth profile of As and In implanted into Si have been measured by RBS (Rutherford Backscattering Spectrometry) with 2 MeV He ions and 6 MeV C ions. Advantages of enhanced depth and mass resolution with C ions have been demonstrated over the conventional He RBS. More reliable information for the depth profile of In and As in Si has been obtained. 12 refs., 3 figs.

  2. Molecular depth profiling of trehalose using a C{sub 60} cluster ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Wucher, Andreas [Department of Physics, University of Duisburg-Essen, D-47048 Duisburg (Germany)], E-mail: andreas.wucher@uni-due.de; Cheng Juan; Winograd, Nicholas [Department of Chemistry, Pennsylvania State University, University Park, PA 16802 (United States)

    2008-12-15

    Molecular depth profiling of organic overlayers was performed using a mass selected fullerene ion beam in conjunction with time-of-flight (TOF-SIMS) mass spectrometry. The characteristics of depth profiles acquired on a 300-nm trehalose film on Si were studied as a function of the impact kinetic energy and charge state of the C{sub 60} projectile ions. We find that the achieved depth resolution depends only weakly upon energy.

  3. Magnetic depth profiling of Fe/Au multilayer using neutron ...

    Indian Academy of Sciences (India)

    Au multilayer sample for characterizing the layer structure and magnetic moment density profile. Fe/Au multilayer shows strong spin-dependent scattering at interfaces, making it a prospective GMR material. Fe/Au multilayer with bilayer ...

  4. Effect of LEO cycling at shallow depths of discharge on MANTECH IPV nickel-hydrogen cells

    Science.gov (United States)

    Smithrick, John J.

    An individual pressure vessel nickel-hydrogen battery is being considered as an alternate for a nickel-cadmium battery on the Hubble Space Telescope. The space telescope battery will primarily be operating at a shallow depth of discharge (10 percent DOD) with an occasional 40 percent DOD. This shallow DOD raises several issues: (1) What is the cycle life. It is projected to be acceptable; however, there is no reported real time data base for validation. (2) The state of charge of the nickel electrode at the beginning of charge is 90 percent. Will this cause an acceleration of divergence in the battery individual cell voltages. (3) After prolonged cycling at 10 percent DOD, will there be enough capacity remaining to support the 40 percent DOD. (4) Is the state of charge really 90 percent during cycling. There is no reported real time data base at shallow depths of discharge. A data base to address the above issues was initiated.

  5. Depth profiles of 129I species in the Bothnian Sea

    DEFF Research Database (Denmark)

    Yi, P.; Aldahan, A.; Possnert, G.

    2013-01-01

    The Bothnian Sea which is located between Finland and Sweden represents an important source of fresh water to the Baltic Sea. We here present new data on the radioactive isotope 129I species from water samples collected in December 2009 at different depths in the Bothnian Sea. Concentrations of 129......, SiO3–Si, but rather poor with NH4–N. The correlations suggest comparable source pathway of 129I− and nutrient parameters, while the source of NH4–N may be different. The small amounts and negligible change of 129IO3 − indicate prevailing extensive reduction of iodate in the Baltic Sea....

  6. XPS and XRF depth patina profiles of ancient silver coins

    Science.gov (United States)

    Caridi, F.; Torrisi, L.; Cutroneo, M.; Barreca, F.; Gentile, C.; Serafino, T.; Castrizio, D.

    2013-05-01

    Ancient silver coins of different historical periods going from IV cent. B.C. up to recent XIX century, coming from different Mediterranean countries have been investigated with different surface physical analyses. X-ray photoelectron spectroscopy (XPS) analysis has been performed by using electron emission induced by 1.4 keV X-rays. X-ray fluorescence (XRF) analysis has been devoted by using 30 keV electron beam. Scanning electron microscopy (SEM) has been employed to analyze the surface morphology and the X-ray map distribution by using a 30 keV microbeam. Techniques were used to investigate about the patina composition and trace elements as a function of the sample depth obtained coupling XPS to 3 keV argon ion sputtering technique.

  7. Deuterium Depth Profile in Neutron-Irradiated Tungsten Exposed to Plasma

    Energy Technology Data Exchange (ETDEWEB)

    Masashi Shimada; G. Cao; Y. Hatano; T. Oda; Y. Oya; M. Hara; P. Calderoni

    2011-05-01

    The effect of radiation damage has been mainly simulated using high-energy ion bombardment. The ions, however, are limited in range to only a few microns into the surface. Hence, some uncertainty remains about the increase of trapping at radiation damage produced by 14 MeV fusion neutrons, which penetrate much farther into the bulk material. With the Japan-US joint research project: Tritium, Irradiations, and Thermofluids for America and Nippon (TITAN), the tungsten samples (99.99 % pure from A.L.M.T., 6mm in diameter, 0.2mm in thickness) were irradiated to high flux neutrons at 50 C and to 0.025 dpa in the High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory (ORNL). Subsequently, the neutron-irradiated tungsten samples were exposed to a high-flux deuterium plasma (ion flux: 1021-1022 m-2s-1, ion fluence: 1025-1026 m-2) in the Tritium Plasma Experiment (TPE) at the Idaho National Laboratory (INL). First results of deuterium retention in neutron-irradiated tungsten exposed in TPE have been reported previously. This paper presents the latest results in our on-going work of deuterium depth profiling in neutron-irradiated tungsten via nuclear reaction analysis. The experimental data is compared with the result from non neutron-irradiated tungsten, and is analyzed with the Tritium Migration Analysis Program (TMAP) to elucidate the hydrogen isotope behavior such as retention and depth distribution in neutron-irradiated and non neutron-irradiated tungsten.

  8. Breadth and Depth of Vocabulary Knowledge and Their Effects on L2 Vocabulary Profiles

    Science.gov (United States)

    Bardakçi, Mehmet

    2016-01-01

    Breadth and depth of vocabulary knowledge have been studied from many different perspectives, but the related literature lacks serious studies dealing with their effects on vocabulary profiles of EFL learners. In this paper, with an aim to fill this gap, the relative effects of breadth and depth of vocabulary knowledge on L2 vocabulary profiles…

  9. Analisis Karakteristik Profil PDD (Percentage Depth Dose) Berkas Foton 6MV Dan 10MV

    OpenAIRE

    Damanik, Yuli Martha K.

    2011-01-01

    Analysis of profile PDD of photon beam 6 MV and 10 MV had conducted in hospital H. Adam Malik Medan by the dose meansurement in the different depth of water phantom. This analysis aims to study the dose percentage on the different depth known as PDD (Percentage Depth Dose). The result of analysis show that the photon beam 6 MV with the standard field area 10 x 10 〖cm〗^2, the accepted dose percentage is 100 % on the depth of 1,6 cm and for the photon beam 10 MV with the standard field area 1...

  10. Nitric oxide assisted C60 secondary ion mass spectrometry for molecular depth profiling of polyelectrolyte multilayers.

    Science.gov (United States)

    Zappalà, G; Motta, V; Tuccitto, N; Vitale, S; Torrisi, A; Licciardello, A

    2015-12-15

    Secondary ion mass spectrometry (SIMS) with polyatomic primary ions provides a successful tool for molecular depth profiling of polymer systems, relevant in many technological applications. Widespread C60 sources, however, cause in some polymers extensive damage with loss of molecular information along depth. We study a method, based on the use of a radical scavenger, for inhibiting ion-beam-induced reactions causing sample damage. Layered polystyrene sulfonate and polyacrylic acid based polyelectrolyte films, behaving differently towards C60 beam-induced damage, were selected and prepared as model systems. They were depth profiled by means of time-of-flight (TOF)-SIMS in dual beam mode, using fullerene ions for sputtering. Nitric oxide was introduced into the analysis chamber as a radical scavenger. The effect of sample cooling combined with NO-dosing on the quality of depth profiles was explored. NO-dosing during C60-SIMS depth profiling of >1 micrometer-thick multilayered polyelectrolytes allows detection, along depth, of characteristic fragments from systems otherwise damaged by C60 bombardment, and increases sputtering yield by more than one order of magnitude. By contrast, NO has little influence on those layers that are well profiled with C60 alone. Such leveling effect, more pronounced at low temperature, leads to a dramatic improvement of profile quality, with a clear definition of interfaces. NO-dosing provides a tool for extending the applicability, in SIMS depth profiling, of the widely spread fullerene ion sources. In view of the acceptable erosion rates on inorganics, obtainable with C60, the method could be of relevance also in connection with the 3D-imaging of hybrid polymer/inorganic systems. Copyright © 2015 John Wiley & Sons, Ltd.

  11. Photothermal radiometric determination of thermal diffusivity depth profiles in a dental resin

    Energy Technology Data Exchange (ETDEWEB)

    MartInez-Torres, P; Alvarado-Gil, J J [Department of Applied Physics, CINVESTAV-Unidad Merida, Antigua Carretera a Progreso Km. 6, 97310, Merida, Yucatan (Mexico); Mandelis, A, E-mail: jjag@mda.cinvestav.m [Center for Advanced Diffusion-Wave Technologies (CADIFT), Department of Mechanical and Industrial Engineering, University of Toronto, 5 King' s College Road, Toronto, Ontario, M5S 3G8 (Canada)

    2010-03-01

    The depth of curing due to photopolymerization in a commercial dental resin is studied using photothermal radiometry. The sample consists of a thick layer of resin on which a thin metallic layer is deposited guaranteeing full opacity of the sample. In this case, purely thermal-wave inverse problem techniques without the interference of optical profiles can be used. Thermal profiles are obtained by heating the coating with a modulated laser beam and performing a modulation frequency scan. Before each frequency scan, photopolymerization was induced using a high power blue LED. However due to the fact that dental resins are highly light dispersive materials, the polymerization process depends strongly on the optical absorption coefficient inducing a depth dependent thermal diffusion in the sample. It is shown that using a robust depth profilometric inverse method one can reconstruct the thermal diffusivity profile of the photopolymerized resin.

  12. Multiple and double scattering contributions to depth resolution and low energy background in hydrogen elastic recoil detection

    Energy Technology Data Exchange (ETDEWEB)

    Wielunski, L.S. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), Lindfield, NSW (Australia). Div. of Applied Physics

    1996-12-31

    The sensitivity of hydrogen elastic recoil detection ( ERD ) is usually limited by the low energy background in the ERD spectrum. A number of 4.5 MeV He{sup ++} hydrogen ERD spectra from different hydrogen implanted samples are compared. The samples are chosen with different atomic numbers from low Z (carbon) to high Z (tungsten carbide) to observe the effects of multiple scattering and double scattering within the sample material. The experimental depth resolution and levels of the low energy background in ERD spectra are compared with theoretical predictions from multiple and double scattering. 10 refs., 2 tabs., 5 figs.

  13. Relaxation of vacancy depth profiles in silicon wafers: A low apparent diffusivity of vacancy species

    OpenAIRE

    Voronkov, Vladimir V.; Falster, Robert; Pichler, Peter

    2014-01-01

    Vacancy depth profiles in silicon wafersinstalled by Rapid Thermal Annealing and monitored by Pt diffusionshow, upon subsequent annealing at 975 or 950 °C, a peculiar evolution: the concentration profile goes down without any trace of vacancy out-diffusion. The estimated apparent diffusivity is less than 1E7 cm2/s at 975 °C. The monitored vacancy species is tentatively identified as a "slow vacancy" that was recently concluded to exist along with other (highly mobile) vacancy species.

  14. Elemental depth profiling of fluoridated hydroxyapatite: saving your dentition by the skin of your teeth?

    Science.gov (United States)

    Müller, Frank; Zeitz, Christian; Mantz, Hubert; Ehses, Karl-Heinz; Soldera, Flavio; Schmauch, Jörg; Hannig, Matthias; Hüfner, Stefan; Jacobs, Karin

    2010-12-21

    Structural and chemical changes that arise from fluoridation of hydroxyapatite (Ca(5)(PO(4))(3)OH or "HAp"), as representing the synthetic counterpart of tooth enamel, are investigated by X-ray photoelectron spectroscopy (XPS). Elemental depth profiles with a depth resolution on the nanometer scale were determined to reveal the effect of fluoridation in neutral (pH = 6.2) and acidic agents (pH = 4.2). With respect to the chemical composition and the crystal structure, XPS depth profiling reveals different effects of the two treatments. In both cases, however, the fluoridation affects the surface only on the nanometer scale, which is in contrast to recent literature with respect to XPS analysis on dental fluoridation, where depth profiles of F extending to several micrometers were reported. In addition to the elemental depth profiles, as published in various other studies, we also present quantitative depth profiles of the compounds CaF(2), Ca(OH)(2), and fluorapatite (FAp) that were recently proposed by a three-layer model concerning the fluoridation of HAp in an acidic agent. The analysis of our experimental data exactly reproduces the structural order of this model, however, on a scale that differs by nearly 2 orders of magnitude from previous predictions. The results also reveal that the amount of Ca(OH)(2) and FAp is small compared to that of CaF(2). Therefore, it has to be asked whether such narrow Ca(OH)(2) and FAp layers really can act as protective layers for the enamel.

  15. In situ neutron depth profiling: A powerful method to probe lithium transport in micro-batteries

    NARCIS (Netherlands)

    Oudenhoven, J.F.M.; Labohm, F.; Mulder, M.; Niessen, R.A.H.; Mulder, F.M.; Notten, P.H.L.

    2011-01-01

    In situ neutron depth profiling (NDP) offers the possibility to observe lithium transport inside micro-batteries during battery operation. It is demonstrated that NDP results are consistent with the results of electrochemical measurements, and that the use of an enriched6LiCoO2 cathode offers more

  16. Advanced carrier depth profiling on Si and Ge with micro four-point probe

    DEFF Research Database (Denmark)

    Clarysse, Trudo; Eyben, Pierre; Parmentier, Brigitte

    2008-01-01

    carrier profiling is an absolute carrier depth profiling technique. On Si, it is found that the more sensitive a structure is to carrier spilling along the bevel, the better the M4PP system performs relative to conventional spreading resistance probe (SRP) due to its much lower probe pressure......-point probe (M4PP) tool. M4PP sheet resistance measurements taken along beveled Si and Ge blanket shallow structures will be investigated. From the differential sheet resistance changes, the underlying carrier profile can be reconstructed without the need to rely on a complicated contact modeling, i.e., M4PP...

  17. Contributions to computer-aided interpretation of ion sputtering depth profiling

    Science.gov (United States)

    Oswald, Steffen; Hoffmann, Volker; Ehrlich, Günter

    1994-09-01

    To evade some of the problems that restrict the quantification of sputtering depth profiling, i.e. the conversion of measured signal intensity vs sputtering time profiles into the concentration vs depth scale in the case of changing sputtering rate with depth, algorithms and computer programs are presented for modelling the intensity vs time profile by computer simulation of the measuring process. Required are only rough a priori information on the sample type under investigation, e.g. implanted material or layer systems, some knowledge of the actual sputtering conditions and basic assumptions on origin, transmission and registration of the analytical signals. The modelled profile may be adapted to the measured one by interactive, stepwise variation of parameters assumed to be important. For scanned ion beams, procedures for efficient estimation of the actual ion current density and of the changing sputtering rate with depth are given too. All calculations can be performed at a desk using any IBM compatible personal computer. Owing to its modular structure, the program may be easily extended and completed according to model refinements by users. Agreement between computed and measured profiles indicates that the a priori assumptions on the true depth profile were correct in all probability. Otherwise, in most cases, further experiments have to be performed in order to decide between experimental artefacts and material-inherent deviations considering also atomic mixing, radiation enhanced diffusion, preferential sputtering and similar effects. Moreover, the quantitative relations between sputtering conditions and crater shape obtainable by the model can support optimization of the measuring conditions particularly with respect to depth resolution. At last, the procedures and algorithms given here are a contribution to the final aim of direct quantification of the results of sputtering depth profiling. This article is an electronic publication in Spectrochimica Acta

  18. Variations in bacterial and archaeal communities along depth profiles of Alaskan soil cores.

    Science.gov (United States)

    Tripathi, Binu Mani; Kim, Mincheol; Kim, Yongwon; Byun, Eunji; Yang, Ji-Woong; Ahn, Jinho; Lee, Yoo Kyung

    2018-01-11

    Understating the microbial communities and ecological processes that influence their structure in permafrost soils is crucial for predicting the consequences of climate change. In this study we investigated the bacterial and archaeal communities along depth profiles of four soil cores collected across Alaska. The bacterial and archaeal diversity (amplicon sequencing) overall decreased along the soil depth but the depth-wise pattern of their abundances (qPCR) varied by sites. The community structure of bacteria and archaea displayed site-specific pattern, with a greater role of soil geochemical characteristics rather than soil depth. In particular, we found significant positive correlations between methane trapped in cores and relative abundance of methanogenic archaeal genera, indicating a strong association between microbial activity and methane production in subsurface soils. We observed that bacterial phylogenetic community assembly tended to be more clustered in surface soils than in deeper soils. Analyses of phylogenetic community turnover among depth profiles across cores indicated that the relative influence of deterministic and stochastic processes was mainly determined by soil properties rather than depth. Overall, our findings emphasize that the vertical distributions of bacterial and archaeal communities in permafrost soils are to a large extent determined by the variation in site-specific soil properties.

  19. Cathodoluminescence depth profiling in SiO sub 2 Ge layers

    CERN Document Server

    Barfels, T; Fitting, H J; Schmidt, B

    2002-01-01

    For investigation of the luminescent center profile cathodoluminescence measurements are used under variation of the primary electron energy E sub 0 2/dots30 keV. Applying a constant incident power regime (E sub 0 x I sub 0 = const), the depth profiles of luminescent centers are deduced from the range of the electron energy transfer profiles dE/dx. Thermally grown SiO sub 2 layers of thickness d = 500 nm have been implanted by Ge sup + -ions of energy 350 keV and doses (0.5-5)10 sup 1 sup 6 ions/cm sup 2. Thus Ge profiles with a concentration maximum of (0.4 - 4) at% at the depth of d sub m /cong240 nm are expected. Afterwards the layers have been partially annealed up to T sub a = 1100 sup o C for one hour in dry nitrogen. After thermal annealing, not only the typical violet luminescence (lambda = 400 nm) of the Ge centers is strongly increased but also the luminescent center profiles are shifted from about 250 nm to 170 nm depth towards the surface. This process should be described by Ge diffusion processes...

  20. 3D Auger quantitative depth profiling of individual nanoscaled III–V heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Hourani, W. [Univ. Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Gorbenko, V. [Univ. Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Univ. Grenoble Alpes, LTM, CNRS, F-38000 Grenoble (France); Barnes, J.-P.; Guedj, C. [Univ. Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Cipro, R.; Moeyaert, J.; David, S.; Bassani, F.; Baron, T. [Univ. Grenoble Alpes, LTM, CNRS, F-38000 Grenoble (France); Martinez, E., E-mail: eugenie.martinez@cea.fr [Univ. Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France)

    2016-11-15

    Highlights: • The nanoscale chemical characterization of III–V heterostructures is performed using Auger depth profiling below decananometric spatial resolution. • Reliable indium quantification is achieved on planar structures for thicknesses down to 9 nm. • Quantitative 3D compositional depth profiles are obtained on patterned structures, with sufficient lateral resolution to analyze one single trench. • The Auger intrinsic spatial resolution is estimated around 150–200 nm using a comparison with HAADF-STEM. • Auger and SIMS provide reliable in-depth chemical analysis of such complex 3D heterostructures, in particular regarding indium quantification. - Abstract: The nanoscale chemical characterization of III–V heterostructures is performed using Auger depth profiling below decananometric spatial resolution. This technique is successfully applied to quantify the elemental composition of planar and patterned III–V heterostructures containing InGaAs quantum wells. Reliable indium quantification is achieved on planar structures for thicknesses down to 9 nm. Quantitative 3D compositional depth profiles are obtained on patterned structures, for trench widths down to 200 nm. The elemental distributions obtained in averaged and pointed mode are compared. For this last case, we show that Zalar rotation during sputtering is crucial for a reliable indium quantification. Results are confirmed by comparisons with secondary ion mass spectrometry, photoluminescence spectroscopy, transmission electron microscopy and electron dispersive X-ray spectroscopy. The Auger intrinsic spatial resolution is quantitatively measured using an original methodology based on the comparison with high angle annular dark field scanning transmission electron microscopy measurements at the nanometric scale.

  1. A multi-detector, digitizer based neutron depth profiling device for characterizing thin film materials

    Energy Technology Data Exchange (ETDEWEB)

    Mulligan, P. L.; Cao, L. R.; Turkoglu, D. [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, Ohio State University, Columbus, Ohio 43210 (United States)

    2012-07-15

    Neutron depth profiling (NDP) is a mature, nondestructive technique used to characterize the concentration of certain light isotopes in a material as a function of depth by measuring the residual energy of charged particles in neutron induced reactions. Historically, NDP has been performed using a single detector, resulting in low intrinsic detection efficiency, and limiting the technique largely to high flux research reactors. In this work, we describe a new NDP instrument design with higher detection efficiency by way of spectrum summing across multiple detectors. Such a design is capable of acquiring a statistically significant charged particle spectrum at facilities limited in neutron flux and operation time.

  2. A continuous OSL scanning method for analysis of radiation depth-dose profiles in bricks

    DEFF Research Database (Denmark)

    Bøtter-Jensen, L.; Jungner, H.; Poolton, N.R.J.

    1995-01-01

    This article describes the development of a method for directly measuring radiation depth-dose profiles from brick, tile and porcelain cores, without the need for sample separation techniques. For the brick cores, examples are shown of the profiles generated by artificial irradiation using...... the different photon energies from Cs-137 and Co-60 gamma sources; comparison is drawn with both the theoretical calculations derived from Monte Carlo simulations, as well as experimental measurements made using more conventional optically stimulated luminescence methods of analysis....

  3. Characterizing contaminant concentrations with depth by using the USGS well profiler in Oklahoma, 2003-9

    Science.gov (United States)

    Smith, S. Jerrod; Becker, Carol J.

    2011-01-01

    Since 2003, the U.S. Geological Survey (USGS) Oklahoma Water Science Center has been using the USGS well profiler to characterize changes in water contribution and contaminant concentrations with depth in pumping public-supply wells in selected aquifers. The tools and methods associated with the well profiler, which were first developed by the USGS California Water Science Center, have been used to investigate common problems such as saline water intrusion in high-yield irrigation wells and metals contamination in high-yield public-supply wells.

  4. Investigating the Fundamentals of Molecular Depth Profiling Using Strong-field Photoionization of Sputtered Neutrals.

    Science.gov (United States)

    Willingham, D; Brenes, D A; Winograd, N; Wucher, A

    2011-01-01

    Molecular depth profiles of model organic thin films were performed using a 40 keV C 60 + cluster ion source in concert with TOF-SIMS. Strong-field photoionization of intact neutral molecules sputtered by 40 keV C 60 + primary ions was used to analyze changes in the chemical environment of the guanine thin films as a function of ion fluence. Direct comparison of the secondary ion and neutral components of the molecular depth profiles yields valuable information about chemical damage accumulation as well as changes in the molecular ionization probability. An analytical protocol based on the erosion dynamics model is developed and evaluated using guanine and trehalose molecular secondary ion signals with and without comparable laser photoionization data.

  5. Experimental analysis of bruises in human volunteers using radiometric depth profiling and diffuse reflectance spectroscopy

    Science.gov (United States)

    Vidovič, Luka; Milanič, Matija; Majaron, Boris

    2015-07-01

    We combine pulsed photothermal radiometry (PPTR) depth profiling with diffuse reflectance spectroscopy (DRS) measurements for a comprehensive analysis of bruise evolution in vivo. While PPTR enables extraction of detailed depth distribution and concentration profiles of selected absorbers (e.g. melanin, hemoglobin), DRS provides information in a wide range of visible wavelengths and thus offers an additional insight into dynamics of the hemoglobin degradation products. Combining the two approaches enables us to quantitatively characterize bruise evolution dynamics. Our results indicate temporal variations of the bruise evolution parameters in the course of bruise self-healing process. The obtained parameter values and trends represent a basis for a future development of an objective technique for bruise age determination.

  6. Depth-profiling by confocal Raman microscopy (CRM): data correction by numerical techniques.

    Science.gov (United States)

    Tomba, J Pablo; Eliçabe, Guillermo E; Miguel, María de la Paz; Perez, Claudio J

    2011-03-01

    The data obtained in confocal Raman microscopy (CRM) depth profiling experiments with dry optics are subjected to significant distortions, including an artificial compression of the depth scale, due to the combined influence of diffraction, refraction, and instrumental effects that operate on the measurement. This work explores the use of (1) regularized deconvolution and (2) the application of simple rescaling of the depth scale as methodologies to obtain an improved, more precise, confocal response. The deconvolution scheme is based on a simple predictive model for depth resolution and the use of regularization techniques to minimize the dramatic oscillations in the recovered response typical of problem inversion. That scheme is first evaluated using computer simulations on situations that reproduce smooth and sharp sample transitions between two materials and finally it is applied to correct genuine experimental data, obtained in this case from a sharp transition (planar interface) between two polymeric materials. It is shown that the methodology recovers very well most of the lost profile features in all the analyzed situations. The use of simple rescaling appears to be only useful for correcting smooth transitions, particularly those extended over distances larger than those spanned by the operative depth resolution, which limits the strategy to the study of profiles near the sample surface. However, through computer simulations, it is shown that the use of water immersion objectives may help to reduce optical distortions and to expand the application window of this simple methodology, which could be useful, for instance, to safely monitor Fickean sorption/desorption of penetrants in polymer films/coatings in a nearly noninvasive way.

  7. Depth profiling of mechanical degradation of PV backsheets after UV exposure

    Science.gov (United States)

    Gu, Xiaohong; Krommenhoek, Peter J.; Lin, Chiao-Chi; Yu, Li-Chieh; Nguyen, Tinh; Watson, Stephanie S.

    2015-09-01

    Polymeric multilayer backsheets protect the photovoltaic modules from damage of moisture and ultraviolet (UV) while providing electrical insulation. Due to the multilayer structures, the properties of the inner layers of the backsheets, including their interfaces, during weathering are not well known. In this study, a commercial type of PPE (polyethylene terephthalate (PET)/PET/ethylene vinyl acetate (EVA)) backsheet films was selected as a model system for a depth profiling study of mechanical properties of a backsheet film during UV exposure. The NIST SPHERE (Simulated Photodegradation via High Energy Radiant Exposure) was used for the accelerated laboratory exposure of the materials with UV at 85°C and two relative humidities (RH) of 5 % (dry) and 60 % (humid). Cryomicrotomy was used to obtain cross-sectional PPE samples. Mechanical depth profiling of the cross-sections of aged and unaged samples was conducted by nanoindentation, and a peak-force based quantitative nanomechanical atomic force microscopy (QNM-AFM) mapping techniquewas used to investigate the microstructure and adhesion properties of the adhesive tie layers. The nanoindentation results show the stiffening of the elastic modulus in the PET outer and pigmented EVA layers. From QNM-AFM, the microstructures and adhesion properties of the adhesive layers between PET outer and core layers and between PET core and EVA inner layers are revealed and found to degrade significantly after aging under humidity environment. The results from mechanical depth profiling of the PPE backsheet are further related to the previous chemical depth profiling of the same material, providing new insights into the effects of accelerated UV and humidity on the degradation of multilayer backsheet.

  8. Measuring Aerosol Optical Depth (AOD and Aerosol Profiles Simultaneously with a Camera Lidar

    Directory of Open Access Journals (Sweden)

    Barnes John

    2016-01-01

    Full Text Available CLidar or camera lidar is a simple, inexpensive technique to measure nighttime tropospheric aerosol profiles. Stars in the raw data images used in the CLidar analysis can also be used to calculate aerosol optical depth simultaneously. A single star can be used with the Langley method or multiple star pairs can be used to reduce the error. The estimated error from data taken under clear sky conditions at Mauna Loa Observatory is approximately +/- 0.01.

  9. Molecular depth profiling of organic photovoltaic heterojunction layers by ToF-SIMS: comparative evaluation of three sputtering beams

    NARCIS (Netherlands)

    Mouhib, T.; Poleunis, C.; Wehbe, N.; Michels, J.J.; Galagan, Y.; Houssiau, L.; Bertrand, P.; Delcorte, A.

    2013-01-01

    With the recent developments in secondary ion mass spectrometry (SIMS), it is now possible to obtain molecular depth profiles and 3D molecular images of organic thin films, i.e. SIMS depth profiles where the molecular information of the mass spectrum is retained through the sputtering of the sample.

  10. Depth Profiles in Maize ( Zea mays L.) Seeds Studied by Photoacoustic Spectroscopy

    Science.gov (United States)

    Hernández-Aguilar, C.; Domínguez-Pacheco, A.; Cruz-Orea, A.; Zepeda-Bautista, R.

    2015-06-01

    Photoacoustic spectroscopy (PAS) has been used to analyze agricultural seeds and can be applied to the study of seed depth profiles of these complex samples composed of different structures. The sample depth profile can be obtained through the photoacoustic (PA) signal, amplitude, and phase at different light modulation frequencies. The PA signal phase is more sensitive to changes of thermal properties in layered samples than the PA signal amplitude. Hence, the PA signal phase can also be used to characterize layers at different depths. Thus, the objective of the present study was to obtain the optical absorption spectra of maize seeds ( Zea mays L.) by means of PAS at different light modulation frequencies (17 Hz, 30 Hz, and 50 Hz) and comparing these spectra with the ones obtained from the phase-resolved method in order to separate the optical absorption spectra of seed pericarp and endosperm. The results suggest the possibility of using the phase-resolved method to obtain optical absorption spectra of different seed structures, at different depths, without damaging the seed. Thus, PAS could be a nondestructive method for characterization of agricultural seeds and thus improve quality control in the food industry.

  11. Accurate ultra-low energy SIMS depth profiling of silicon semiconductors

    CERN Document Server

    Ormsby, T J

    2000-01-01

    surface topography has two detrimental effects, a loss in depth resolution and a variation in the sputter yield, both of which have been quantified. A wide range of analysis conditions were investigated, at O sub 2 sup + beam energies up to 1 keV, the only angles where ripples do not develop within the top 200 nm of a profile are those using near-normal incidence (theta sub p <= 30 deg) ion bombardment. Since the invention of the bipolar transistor in 1947, lateral dimensions of semiconductor devices have reduced by a factor of 4 and in-depth dimensions by some two orders of magnitude. This size reduction is continually making the accurate measurement of the latest generation of semiconductor devices more difficult. Secondary ion mass spectrometry (SIMS) is a highly effective analytical technique, traditionally used to measure concentration depth profiles, due to its high sensitivity and good depth resolution. The development of the floating ion gun (FLIG) at Warwick, allows the routine use of sub-keV beam...

  12. A comparison of mixing depths observed by ground-based wind profilers and an airborne lidar

    Energy Technology Data Exchange (ETDEWEB)

    White, A.B.; Senff, C. [Univ. of Colorado/NOAA Environmental Technology Lab., Cooperative Inst. for Research in Environmental Sciences, Boulder, CO (United States); Banta, R.M. [NOAA Environmental Technology Lab., Boulder, CO (United States)

    1997-10-01

    The mixing depth is one of the most important parameters in air pollution studies because it determines the vertical extent of the `box` in which pollutants are mixed and dispersed. During the 1995 Southern Oxidants Study (SOS95), scientists from the National Oceanic and Atmospheric Administration Environmental Technology Laboratory (NOAA/ETL) deployed four 915-MHz boundary-layer radar/wind profilers (hereafter radars) in and around the Nashville, Tennessee metropolitan area. Scientists from NOAA/ETL also operated an ultraviolet differential absorption lidar (DIAL) onboard a CASA-212 aircraft. Profiles from radar and DIAL can be used to derive estimates of the mixing depth. The methods used for both instruments are similar in that they depend on information derived from the backscattered power. However, different scattering mechanisms for the radar and DIAL mean that different tracers of mixing depth are measured. In this paper we compare the mixing depth estimates obtained from the radar and DIAL and discuss the similarities and differences that occur. (au)

  13. Reconstruction of GaAs/AlAs supperlattice multilayer structure by quantification of AES and SIMS sputter depth profiles

    Science.gov (United States)

    Kang, H. L.; Lao, J. B.; Li, Z. P.; Yao, W. Q.; Liu, C.; Wang, J. Y.

    2016-12-01

    The GaAs/AlAs superlattice multilayer structures were deposited on GaAs (1 0 0) substrates by molecular beam epitaxial (MBE) technique. The as-prepared samples were characterized respectively by Auger Electron Spectroscopy (AES) and Secondary Ion Mass Spectroscopy (SIMS) depth profiling techniques. The measured depth profiles were then fitted by the Mixing-Roughness-Information (MRI) model. The depth resolution values for both depth profiling techniques were evaluated quantitatively from the fitted MRI parameters and the as-prepared GaAs/AlAs multilayer structure was determined accordingly.

  14. Reconstruction of GaAs/AlAs supperlattice multilayer structure by quantification of AES and SIMS sputter depth profiles

    Energy Technology Data Exchange (ETDEWEB)

    Kang, H.L.; Lao, J.B. [Department of Physics, Shantou University, Shantou 515063, Guangdong (China); Li, Z.P.; Yao, W.Q. [Analysis Center of Tsinghua University, Beijing 100084 (China); Liu, C. [Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Wang, J.Y., E-mail: wangjy@stu.edu.cn [Department of Physics, Shantou University, Shantou 515063, Guangdong (China)

    2016-12-01

    Highlights: • GaAs/AlAs superlattice multilayered structure is reconstructed. • Measured depth profiling data are quantitatively analyzed. • Depth resolution and interface roughness values are quantitatively evaluated. - Abstract: The GaAs/AlAs superlattice multilayer structures were deposited on GaAs (1 0 0) substrates by molecular beam epitaxial (MBE) technique. The as-prepared samples were characterized respectively by Auger Electron Spectroscopy (AES) and Secondary Ion Mass Spectroscopy (SIMS) depth profiling techniques. The measured depth profiles were then fitted by the Mixing-Roughness-Information (MRI) model. The depth resolution values for both depth profiling techniques were evaluated quantitatively from the fitted MRI parameters and the as-prepared GaAs/AlAs multilayer structure was determined accordingly.

  15. Hardness depth profiling in steel by photothermal testing; Erfassung von Haertetiefe und Haerteprofil in Eisenwerkstoffen mit photothermischen Verfahren

    Energy Technology Data Exchange (ETDEWEB)

    Walther, H.G.; Lan, T.T.N. [Friedrich-Schiller-Univ. Jena (Germany). Inst. fuer Optik und Quantenelektronik

    1998-05-01

    The experimentally verified connection between microhardness and local thermal conductivity enables the photothermal hardness depth profiling. This can be done by estimating the thermal conductivity depth profile from frequency dependent radiometric measurements. The accuracy of the retrieval depends strongly on signal-to-noise ratio. According to the underlying theoretical model the generation of plane thermal waves probing the material under test is required. A numerical inversion technique is presented to approximate the thermal conductivity profile by a set of linear slopes. Measurements are performed at case and laser hardened specimen to verify the feasibility of photothermal hardness depth profiling. (orig.) 17 refs.

  16. The effect of particle properties on the depth profile of buoyant plastics in the ocean

    Science.gov (United States)

    Kooi, Merel; Reisser, Julia; Slat, Boyan; Ferrari, Francesco F.; Schmid, Moritz S.; Cunsolo, Serena; Brambini, Roberto; Noble, Kimberly; Sirks, Lys-Anne; Linders, Theo E. W.; Schoeneich-Argent, Rosanna I.; Koelmans, Albert A.

    2016-10-01

    Most studies on buoyant microplastics in the marine environment rely on sea surface sampling. Consequently, microplastic amounts can be underestimated, as turbulence leads to vertical mixing. Models that correct for vertical mixing are based on limited data. In this study we report measurements of the depth profile of buoyant microplastics in the North Atlantic subtropical gyre, from 0 to 5 m depth. Microplastics were separated into size classes (0.5-1.5 and 1.5-5.0 mm) and types (‘fragments’ and ‘lines’), and associated with a sea state. Microplastic concentrations decreased exponentially with depth, with both sea state and particle properties affecting the steepness of the decrease. Concentrations approached zero within 5 m depth, indicating that most buoyant microplastics are present on or near the surface. Plastic rise velocities were also measured, and were found to differ significantly for different sizes and shapes. Our results suggest that (1) surface samplers such as manta trawls underestimate total buoyant microplastic amounts by a factor of 1.04-30.0 and (2) estimations of depth-integrated buoyant plastic concentrations should be done across different particle sizes and types. Our findings can assist with improving buoyant ocean plastic vertical mixing models, mass balance exercises, impact assessments and mitigation strategies.

  17. The effect of particle properties on the depth profile of buoyant plastics in the ocean

    Science.gov (United States)

    Kooi, Merel; Reisser, Julia; Slat, Boyan; Ferrari, Francesco F.; Schmid, Moritz S.; Cunsolo, Serena; Brambini, Roberto; Noble, Kimberly; Sirks, Lys-Anne; Linders, Theo E. W.; Schoeneich-Argent, Rosanna I.; Koelmans, Albert A.

    2016-01-01

    Most studies on buoyant microplastics in the marine environment rely on sea surface sampling. Consequently, microplastic amounts can be underestimated, as turbulence leads to vertical mixing. Models that correct for vertical mixing are based on limited data. In this study we report measurements of the depth profile of buoyant microplastics in the North Atlantic subtropical gyre, from 0 to 5 m depth. Microplastics were separated into size classes (0.5–1.5 and 1.5–5.0 mm) and types (‘fragments’ and ‘lines’), and associated with a sea state. Microplastic concentrations decreased exponentially with depth, with both sea state and particle properties affecting the steepness of the decrease. Concentrations approached zero within 5 m depth, indicating that most buoyant microplastics are present on or near the surface. Plastic rise velocities were also measured, and were found to differ significantly for different sizes and shapes. Our results suggest that (1) surface samplers such as manta trawls underestimate total buoyant microplastic amounts by a factor of 1.04–30.0 and (2) estimations of depth-integrated buoyant plastic concentrations should be done across different particle sizes and types. Our findings can assist with improving buoyant ocean plastic vertical mixing models, mass balance exercises, impact assessments and mitigation strategies. PMID:27721460

  18. The effect of particle properties on the depth profile of buoyant plastics in the ocean.

    Science.gov (United States)

    Kooi, Merel; Reisser, Julia; Slat, Boyan; Ferrari, Francesco F; Schmid, Moritz S; Cunsolo, Serena; Brambini, Roberto; Noble, Kimberly; Sirks, Lys-Anne; Linders, Theo E W; Schoeneich-Argent, Rosanna I; Koelmans, Albert A

    2016-10-10

    Most studies on buoyant microplastics in the marine environment rely on sea surface sampling. Consequently, microplastic amounts can be underestimated, as turbulence leads to vertical mixing. Models that correct for vertical mixing are based on limited data. In this study we report measurements of the depth profile of buoyant microplastics in the North Atlantic subtropical gyre, from 0 to 5 m depth. Microplastics were separated into size classes (0.5-1.5 and 1.5-5.0 mm) and types ('fragments' and 'lines'), and associated with a sea state. Microplastic concentrations decreased exponentially with depth, with both sea state and particle properties affecting the steepness of the decrease. Concentrations approached zero within 5 m depth, indicating that most buoyant microplastics are present on or near the surface. Plastic rise velocities were also measured, and were found to differ significantly for different sizes and shapes. Our results suggest that (1) surface samplers such as manta trawls underestimate total buoyant microplastic amounts by a factor of 1.04-30.0 and (2) estimations of depth-integrated buoyant plastic concentrations should be done across different particle sizes and types. Our findings can assist with improving buoyant ocean plastic vertical mixing models, mass balance exercises, impact assessments and mitigation strategies.

  19. Tracking water pathways in steep hillslopes by δ18O depth profiles of soil water

    Science.gov (United States)

    Mueller, Matthias H.; Alaoui, Abdallah; Kuells, Christoph; Leistert, Hannes; Meusburger, Katrin; Stumpp, Christine; Weiler, Markus; Alewell, Christine

    2014-11-01

    Assessing temporal variations in soil water flow is important, especially at the hillslope scale, to identify mechanisms of runoff and flood generation and pathways for nutrients and pollutants in soils. While surface processes are well considered and parameterized, the assessment of subsurface processes at the hillslope scale is still challenging since measurement of hydrological pathways is connected to high efforts in time, money and personnel work. The latter might not even be possible in alpine environments with harsh winter processes. Soil water stable isotope profiles may offer a time-integrating fingerprint of subsurface water pathways. In this study, we investigated the suitability of soil water stable isotope (δ18O) depth profiles to identify water flow paths along two transects of steep subalpine hillslopes in the Swiss Alps. We applied a one-dimensional advection-dispersion model using δ18O values of precipitation (ranging from -24.7 to -2.9‰) as input data to simulate the δ18O profiles of soil water. The variability of δ18O values with depth within each soil profile and a comparison of the simulated and measured δ18O profiles were used to infer information about subsurface hydrological pathways. The temporal pattern of δ18O in precipitation was found in several profiles, ranging from -14.5 to -4.0‰. This suggests that vertical percolation plays an important role even at slope angles of up to 46°. Lateral subsurface flow and/or mixing of soil water at lower slope angles might occur in deeper soil layers and at sites near a small stream. The difference between several observed and simulated δ18O profiles revealed spatially highly variable infiltration patterns during the snowmelt periods: The δ18O value of snow (-17.7 ± 1.9‰) was absent in several measured δ18O profiles but present in the respective simulated δ18O profiles. This indicated overland flow and/or preferential flow through the soil profile during the melt period. The applied

  20. Depth profiling of galvanoaluminium-nickel coatings on steel by UV- and VIS-LIBS

    Science.gov (United States)

    Nagy, T. O.; Pacher, U.; Giesriegl, A.; Weimerskirch, M. J. J.; Kautek, W.

    2017-10-01

    Laser-induced depth profiling was applied to the investigation of galvanised steel sheets as a typical modern multi-layer coating system for environmental corrosion protection. The samples were ablated stepwise by the use of two different wavelengths of a frequency-converted Nd:YAG-laser, 266 nm and 532 nm, with a pulse duration of τ = 4 ns at fluences ranging from F = 50 to 250 J cm-2. The emission light of the resulting plasma was analysed as a function of both penetration depth and elemental spectrum in terms of linear correlation analysis. Elemental depth profiles were calculated and compared to EDX-cross sections of the cut sample. A proven mathematical algorithm designed for the reconstruction of layer structures from distorted emission traces caused by the Gaussian ablation profile can even resolve thin intermediate layers in terms of depth and thickness. The obtained results were compared to a purely thermally controlled ablation model. Thereby light-plasma coupling is suggested to be a possible cause of deviations in the ablation behaviour of Al. The average ablation rate h as a function of fluence F for Ni ranges from 1 to 3.5 μm/pulse for λ = 266 nm as well as for λ = 532 nm. In contrast, the range of h for Al differs from 2 to 4 μm/pulse for λ = 532 nm and 4 to 8 μm/pulse for λ = 266 nm in the exact same fluence range on the exact same sample.

  1. Acclimation to different depths by the marine angiosperm Posidonia oceanica: transcriptomic and proteomic profiles

    Science.gov (United States)

    Dattolo, Emanuela; Gu, Jenny; Bayer, Philipp E.; Mazzuca, Silvia; Serra, Ilia A.; Spadafora, Antonia; Bernardo, Letizia; Natali, Lucia; Cavallini, Andrea; Procaccini, Gabriele

    2013-01-01

    For seagrasses, seasonal and daily variations in light and temperature represent the mains factors driving their distribution along the bathymetric cline. Changes in these environmental factors, due to climatic and anthropogenic effects, can compromise their survival. In a framework of conservation and restoration, it becomes crucial to improve our knowledge about the physiological plasticity of seagrass species along environmental gradients. Here, we aimed to identify differences in transcriptomic and proteomic profiles, involved in the acclimation along the depth gradient in the seagrass Posidonia oceanica, and to improve the available molecular resources in this species, which is an important requisite for the application of eco-genomic approaches. To do that, from plant growing in shallow (−5 m) and deep (−25 m) portions of a single meadow, (i) we generated two reciprocal Expressed Sequences Tags (EST) libraries using a Suppressive Subtractive Hybridization (SSH) approach, to obtain depth/specific transcriptional profiles, and (ii) we identified proteins differentially expressed, using the highly innovative USIS mass spectrometry methodology, coupled with 1D-SDS electrophoresis and labeling free approach. Mass spectra were searched in the open source Global Proteome Machine (GPM) engine against plant databases and with the X!Tandem algorithm against a local database. Transcriptional analysis showed both quantitative and qualitative differences between depths. EST libraries had only the 3% of transcripts in common. A total of 315 peptides belonging to 64 proteins were identified by mass spectrometry. ATP synthase subunits were among the most abundant proteins in both conditions. Both approaches identified genes and proteins in pathways related to energy metabolism, transport and genetic information processing, that appear to be the most involved in depth acclimation in P. oceanica. Their putative rules in acclimation to depth were discussed. PMID:23785376

  2. Quantitative considerations in medium energy ion scattering depth profiling analysis of nanolayers

    Energy Technology Data Exchange (ETDEWEB)

    Zalm, P.C.; Bailey, P. [International Institute for Accelerator Applications, University of Huddersfield, Queensgate, Huddersfield HD1 3DH (United Kingdom); Reading, M.A. [Physics and Materials Research Centre, University of Salford, Salford M5 4WT (United Kingdom); Rossall, A.K. [International Institute for Accelerator Applications, University of Huddersfield, Queensgate, Huddersfield HD1 3DH (United Kingdom); Berg, J.A. van den, E-mail: j.vandenberg@hud.ac.uk [International Institute for Accelerator Applications, University of Huddersfield, Queensgate, Huddersfield HD1 3DH (United Kingdom)

    2016-11-15

    The high depth resolution capability of medium energy ion scattering (MEIS) is becoming increasingly relevant to the characterisation of nanolayers in e.g. microelectronics. In this paper we examine the attainable quantitative accuracy of MEIS depth profiling. Transparent but reliable analytical calculations are used to illustrate what can ultimately be achieved for dilute impurities in a silicon matrix and the significant element-dependence of the depth scale, for instance, is illustrated this way. Furthermore, the signal intensity-to-concentration conversion and its dependence on the depth of scattering is addressed. Notably, deviations from the Rutherford scattering cross section due to screening effects resulting in a non-coulombic interaction potential and the reduction of the yield owing to neutralization of the exiting, backscattered H{sup +} and He{sup +} projectiles are evaluated. The former mainly affects the scattering off heavy target atoms while the latter is most severe for scattering off light target atoms and can be less accurately predicted. However, a pragmatic approach employing an extensive data set of measured ion fractions for both H{sup +} and He{sup +} ions scattered off a range of surfaces, allows its parameterization. This has enabled the combination of both effects, which provides essential information regarding the yield dependence both on the projectile energy and the mass of the scattering atom. Although, absolute quantification, especially when using He{sup +}, may not always be achievable, relative quantification in which the sum of all species in a layer adds up to 100%, is generally possible. This conclusion is supported by the provision of some examples of MEIS derived depth profiles of nanolayers. Finally, the relative benefits of either using H{sup +} or He{sup +} ions are briefly considered.

  3. Acclimation to different depths by the marine angiosperm Posidonia oceanica: transcriptomic and proteomic profiles

    Directory of Open Access Journals (Sweden)

    Emanuela eDattolo

    2013-06-01

    Full Text Available For seagrasses, seasonal and daily variations in light and temperature represent the mains factors driving their distribution along the bathymetric cline. Changes in these environmental factors, due to climatic and anthropogenic effects, can compromise their survival. In a framework of conservation and restoration, it becomes crucial to improve our knowledge about the physiological plasticity of seagrass species along environmental gradients. Here, we aimed to identify differences in transcriptomic and proteomic profiles, involved in the acclimation along the depth gradient in the seagrass Posidonia oceanica, and to improve the available molecular resources in this species, which is an important requisite for the application of eco-genomic approaches. To do that, from plant growing in the shallow (-5m and a deep (-25m portions of a single meadow, (i we generated two reciprocal EST (Expressed Sequences Tags libraries using a Suppressive Subtractive Hybridization (SSH approach, to obtain depth/specific transcriptional profiles, and (ii we identified proteins differentially expressed, using the highly innovative USIS mass spectrometry methodology, coupled with 1D-SDS electrophoresis and labeling free approach. Mass spectra were searched in the open source Global Proteome Machine (GPM engine against plant databases and with the X!Tandem algorithm against a local database. Transcriptional analysis showed both quantitative and qualitative differences between depths. EST libraries had only the 3% of transcripts in common. A total of 315 peptides belonging to 64 proteins were identified by mass spectrometry. ATP synthase subunits were among the most abundant proteins in both conditions. Both approaches identified genes and proteins in pathways related to energy metabolism, transport and genetic information processing, that appear o be the most involved in depth acclimation in P. oceanica. Their putative rules in acclimation to depth were discussed.

  4. Feasibility of depth profiling of animal tissue by ultrashort pulse laser ablation.

    Science.gov (United States)

    Milasinovic, Slobodan; Liu, Yaoming; Bhardwaj, Chhavi; Blaze M T, Melvin; Gordon, Robert J; Hanley, Luke

    2012-05-01

    Experiments were performed to examine the feasibility of mass spectrometry (MS) depth profiling of animal tissue by ~75 fs, 800 nm laser pulses to expose underlying layers of tissue for subsequent MS analysis. Matrix assisted laser desorption ionization mass spectrometry (MALDI-MS) was used to analyze phospholipids and proteins from both intact bovine eye lens tissue and tissue ablated by ultrashort laser pulses. Laser desorption postionization mass spectrometry (LDPI-MS) with 10.5 eV single photon ionization was also used to analyze cholesterol and other small molecules in the tissue before and after laser ablation. Scanning electron microscopy was applied to examine the ablation patterns in the tissue and estimate the depth of the ablation craters. Ultrashort pulse laser ablation was found to be able to remove a layer of several tens of micrometers from the surface of eye lens tissue while leaving the underlying tissue relatively undamaged for subsequent MS analysis. MS analysis of cholesterol, phospholipids, peptides, and various unidentified species did not reveal any chemical damage caused by ultrashort pulse laser ablation for analytes smaller than ~6 kDa. However, a drop in intensity of larger protein ions was detected by MALDI-MS following laser ablation. An additional advantage was that ablated tissue displayed up to an order of magnitude higher signal intensities than intact tissue when subsequently analyzed by MS. These results support the use of ultrashort pulse laser ablation in combination with MS analysis to permit depth profiling of animal tissue.

  5. Dealloying evidence on corroded brass by laser-induced breakdown spectroscopy mapping and depth profiling measurements

    Science.gov (United States)

    Cerrato, R.; Casal, A.; Mateo, M. P.; Nicolas, G.

    2017-04-01

    The dealloying phenomenon, also called demetalification, is a; consequence of a corrosion problem found in binary alloys where an enrichment of one of the two main elements of the alloy is produced at the expense of the leaching of the other element. In the present work, the ability of laser induced breakdown spectroscopy (LIBS) for the detection and characterization of dealloying films formed on metal has been tested. For this purpose, specific areas of brass specimens have been subjected to a chemical attack of the surface in order to produce a selective leaching of zinc or dezincification. For the lateral and in-depth characterization of the dealloyed areas by LIBS, depth profiles, 2D and 3D maps have been generated from the treated samples and from a reference non-treated sample. The differences in the maps and depth profiles between the corroded and non-corroded regions have allowed to reveal the localization and extension of the dealloying process along the brass sample surface and to estimate the thickness of the dezincification layers, demonstrating the capability of LIBS technique for the characterization of dealloying phenomena.

  6. Mobile depth profiling and sub-surface imaging techniques for historical paintings—A review

    Energy Technology Data Exchange (ETDEWEB)

    Alfeld, Matthias, E-mail: matthias.alfeld@desy.de [University of Hamburg, Department of Chemistry, Martin-Luther-King Platz 6, D-20146 Hamburg (Germany); University of Antwerp, Department of Chemistry, Groenenbrogerlaan 171, B-2020 Antwerp (Belgium); Broekaert, José A.C., E-mail: jose.broekaert@chemie.uni-hamburg.de [University of Hamburg, Department of Chemistry, Martin-Luther-King Platz 6, D-20146 Hamburg (Germany)

    2013-10-01

    Hidden, sub-surface paint layers and features contain valuable information for the art-historical investigation of a painting's past and for its conservation for coming generations. The number of techniques available for the study of these features has been considerably extended in the last decades and established techniques have been refined. This review focuses on mobile non-destructive subsurface imaging and depth profiling techniques, which allow for the in-situ investigation of easel paintings, i.e. paintings on a portable support. Among the techniques discussed are: X-ray radiography and infrared reflectography, which are long established methods and are in use for several decades. Their capabilities of element/species specific imaging have been extended by the introduction of energy/wavelength resolved measurements. Scanning macro-X-ray fluorescence analysis made it for the first time possible to acquire elemental distribution images in-situ and optical coherence tomography allows for the non-destructive study the surface paint layers in virtual cross-sections. These techniques and their variants are presented next to other techniques, such as Terahertz imaging, Nuclear Magnetic Resonance depth profiling and established techniques for non destructive testing (thermography, ultrasonic imaging and laser based interference methods) applied in the conservation of historical paintings. Next to selected case studies the capabilities and limitations of the techniques are discussed. - Highlights: • All mobile sub-surface and depth-profiling techniques for paintings are reviewed. • The number of techniques available has increased considerably in the last years. • X-ray radiography and infrared reflectography are still the most used techniques. • Scanning macro-XRF and optical coherence tomography begin to establish. • Industrial non destructive testing techniques support the preservation of paintings.

  7. Three-Dimensional Mapping of Soil Organic Carbon by Combining Kriging Method with Profile Depth Function

    OpenAIRE

    Chen, Chong; Hu, Kelin; Li, Hong; Yun, Anping; Li, Baoguo

    2015-01-01

    Understanding spatial variation of soil organic carbon (SOC) in three-dimensional direction is helpful for land use management. Due to the effect of profile depths and soil texture on vertical distribution of SOC, the stationary assumption for SOC cannot be met in the vertical direction. Therefore the three-dimensional (3D) ordinary kriging technique cannot be directly used to map the distribution of SOC at a regional scale. The objectives of this study were to map the 3D distribution of SOC ...

  8. Effects of soil amendment on gas depth profiles in soil monoliths using direct mass spectrometric measurement.

    Science.gov (United States)

    Sheppard, S K; Lloyd, D

    2002-08-01

    Land use and agricultural practices are known to influence the source and sink concentrations of various gases, including greenhouse gases (NOx CH4 and CO2). in soils. With everincreasing production of domestic sewage sludge and the prohibition of disposal at sea, pressure on waste disposal increases. Anaerobically digested domestic sewage sludge and/or lime were applied to an upland. Scottish soil and their effects on gas depth profiles monitored as indicators of microbial processes of the soil ecosystem. The concentrations of various gases (Ar, O2. CO2, CH4, N2, NOx) were measured simultaneously at each depth using membrane inlet mass spectrometry (MIMS). This technique enables the direct measurement of multiple gas species throughout soil cores with minimal disturbance. Intact soil monoliths were collected from the sample site, following amendment, and maintained in a constant temperature, environmental growth chambers. Statistical analyses (one-way ANOVA and LSD tests) were conducted to identify the depths at which gas concentrations in amended cores were significantly different from those in control (un-amended) cores. Significant effects were observed on the concentration of CO2, CH4, NOx and N2 at certain depths. Average CH4 concentration was consistently higher (>1 microM) in the upper horizon following application of sludge and sludge and lime together. N2 and NOx concentrations were elevated in cores treated with lime by approximately 100 and 32 microM. respectively, in much of the upper horizon. CO2 concentration increased above control mean values, at certain depths, following application of either sludge or lime. Some explanation for the changes in soil gas concentration was provided by reference to the microorganism assemblages and the gases associated with biochemistry of nitrification, denitrification, methane oxidation and methanogenesis.

  9. Mobile depth profiling and sub-surface imaging techniques for historical paintings—A review

    Science.gov (United States)

    Alfeld, Matthias; Broekaert, José A. C.

    2013-10-01

    Hidden, sub-surface paint layers and features contain valuable information for the art-historical investigation of a painting's past and for its conservation for coming generations. The number of techniques available for the study of these features has been considerably extended in the last decades and established techniques have been refined. This review focuses on mobile non-destructive subsurface imaging and depth profiling techniques, which allow for the in-situ investigation of easel paintings, i.e. paintings on a portable support. Among the techniques discussed are: X-ray radiography and infrared reflectography, which are long established methods and are in use for several decades. Their capabilities of element/species specific imaging have been extended by the introduction of energy/wavelength resolved measurements. Scanning macro-X-ray fluorescence analysis made it for the first time possible to acquire elemental distribution images in-situ and optical coherence tomography allows for the non-destructive study the surface paint layers in virtual cross-sections. These techniques and their variants are presented next to other techniques, such as Terahertz imaging, Nuclear Magnetic Resonance depth profiling and established techniques for non destructive testing (thermography, ultrasonic imaging and laser based interference methods) applied in the conservation of historical paintings. Next to selected case studies the capabilities and limitations of the techniques are discussed.

  10. Nitrogen diffusion and nitrogen depth profiles in expanded austenite: experimental assessment, numerical simulation and role of stress

    DEFF Research Database (Denmark)

    Christiansen, Thomas; Dahl, Kristian Vinter; Somers, Marcel A. J.

    2008-01-01

    The present paper addresses the experimental assessment of the concentration dependent nitrogen diffusion coefficient in stress free expanded austenite foils from thermogravimetry, the numerical simulation of nitrogen concentration depth profiles on growth of expanded austenite into stainless ste...

  11. Comparability and accuracy of nitrogen depth profiling in nitrided austenitic stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Manova, D. [Leibniz-Institut für Oberflächenmodifizierung, 04318 Leipzig (Germany); Díaz, C. [AIN Centro de Ingeniería Avanzada de Superficies, 31191 Cordovilla, Pamplona (Spain); Pichon, L. [Institut P' , UPR3346 CNRS-Université de Poitiers-ISAE-ENSMA, Bat. SP2MI, Téléport 2, Boulevard Marie et Pierre Curie, BP30179, 86962 Chasseneuil Futuroscope Cedex (France); Abrasonis, G. [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01314 Dresden (Germany); Mändl, S., E-mail: stephan.maendl@iom-leipzig.de [Leibniz-Institut für Oberflächenmodifizierung, 04318 Leipzig (Germany)

    2015-04-15

    A comparative study of nitrogen depth profiles in low energy ion implantation nitrided austenitic stainless steel 1.4301 by glow discharge optical emission spectroscopy (GDOES), secondary ion mass spectrometry (SIMS) and nuclear reaction analysis (NRA) is presented. All methods require calibration either from reference samples or known scattering or reaction cross sections for the nitrogen concentration, while the methods producing a sputter crater – SIMS and GDOES – need additional conversion from sputter time to depth. NRA requires an assumption of material density for a correct conversion from the ‘natural’ units inherent to all ion beam analysis methods into ‘conventional’ depth units. It is shown that a reasonable agreement of the absolute concentrations and very good agreement of the layer thickness is obtained. The observed differences in broadening between the nitrogen distribution near the surface and the deeper region of the nitrided layer–steel interface are discussed on the basis of surface contaminations, surface roughening and energy straggling effects.

  12. Thermal depth profiling of materials for defect detection using hot disk technique

    Directory of Open Access Journals (Sweden)

    B. M. Mihiretie

    2016-08-01

    Full Text Available A novel application of the hot disk transient plane source technique is described. The new application yields the thermal conductivity of materials as a function of the thermal penetration depth which opens up opportunities in nondestructive testing of inhomogeneous materials. The system uses the hot disk sensor placed on the material surface to create a time varying temperature field. The thermal conductivity is then deduced from temperature evolution of the sensor, whereas the probing depth (the distance the heat front advanced away from the source is related to the product of measurement time and thermal diffusivity. The presence of inhomogeneity in the structure is manifested in thermal conductivity versus probing depth plot. Such a plot for homogeneous materials provides fairly constant value. The deviation from the homogeneous curve caused by defects in the structure is used for inhomogeneity detection. The size and location of the defect in the structure determines the sensitivity and possibility of detection. In addition, a complementary finite element numerical simulation through COMSOL Multiphysics is employed to solve the heat transfer equation. Temperature field profile of a model material is obtained from these simulations. The average rise in temperature of the heat source is calculated and used to demonstrate the effect of the presence of inhomogeneity in the system.

  13. Numerical investigation of depth profiling capabilities of helium and neon ions in ion microscopy

    Directory of Open Access Journals (Sweden)

    Patrick Philipp

    2016-11-01

    Full Text Available The analysis of polymers by secondary ion mass spectrometry (SIMS has been a topic of interest for many years. In recent years, the primary ion species evolved from heavy monatomic ions to cluster and massive cluster primary ions in order to preserve a maximum of organic information. The progress in less-damaging sputtering goes along with a loss in lateral resolution for 2D and 3D imaging. By contrast the development of a mass spectrometer as an add-on tool for the helium ion microscope (HIM, which uses finely focussed He+ or Ne+ beams, allows for the analysis of secondary ions and small secondary cluster ions with unprecedented lateral resolution. Irradiation induced damage and depth profiling capabilities obtained with these light rare gas species have been far less investigated than ion species used classically in SIMS. In this paper we simulated the sputtering of multi-layered polymer samples using the BCA (binary collision approximation code SD_TRIM_SP to study preferential sputtering and atomic mixing in such samples up to a fluence of 1018 ions/cm2. Results show that helium primary ions are completely inappropriate for depth profiling applications with this kind of sample materials while results for neon are similar to argon. The latter is commonly used as primary ion species in SIMS. For the two heavier species, layers separated by 10 nm can be distinguished for impact energies of a few keV. These results are encouraging for 3D imaging applications where lateral and depth information are of importance.

  14. Numerical investigation of depth profiling capabilities of helium and neon ions in ion microscopy.

    Science.gov (United States)

    Philipp, Patrick; Rzeznik, Lukasz; Wirtz, Tom

    2016-01-01

    The analysis of polymers by secondary ion mass spectrometry (SIMS) has been a topic of interest for many years. In recent years, the primary ion species evolved from heavy monatomic ions to cluster and massive cluster primary ions in order to preserve a maximum of organic information. The progress in less-damaging sputtering goes along with a loss in lateral resolution for 2D and 3D imaging. By contrast the development of a mass spectrometer as an add-on tool for the helium ion microscope (HIM), which uses finely focussed He+ or Ne+ beams, allows for the analysis of secondary ions and small secondary cluster ions with unprecedented lateral resolution. Irradiation induced damage and depth profiling capabilities obtained with these light rare gas species have been far less investigated than ion species used classically in SIMS. In this paper we simulated the sputtering of multi-layered polymer samples using the BCA (binary collision approximation) code SD_TRIM_SP to study preferential sputtering and atomic mixing in such samples up to a fluence of 1018 ions/cm2. Results show that helium primary ions are completely inappropriate for depth profiling applications with this kind of sample materials while results for neon are similar to argon. The latter is commonly used as primary ion species in SIMS. For the two heavier species, layers separated by 10 nm can be distinguished for impact energies of a few keV. These results are encouraging for 3D imaging applications where lateral and depth information are of importance.

  15. Modelling the evolution of composition-and stress-depth profiles in austenitic stainless steels during low-temperature nitriding

    DEFF Research Database (Denmark)

    Jespersen, Freja Nygaard; Hattel, Jesper Henri; Somers, Marcel A. J.

    2016-01-01

    . In the present paper solid mechanics was combined with thermodynamics and diffusion kinetics to simulate the evolution of composition-depth and stress-depth profiles resulting from nitriding. The model takes into account a composition-dependent diffusion coefficient of nitrogen in expanded austenite, short range...

  16. Definition of initial conditions and soil profile depth for Hydrological Land Surface Models in Cold Regions

    Science.gov (United States)

    Sapriza-Azuri, G.; Gamazo, P. A.; Razavi, S.; Wheater, H. S.

    2016-12-01

    Earth system models are essential for the evaluation of the impact of climate change. At global and regional scales, General Circulation Models (GCM) and Regional Climate Models (RCM) are used to simulate climate change evolution. Hydrological Land Surface Models (HLSM) are used along with GCMs and RCMs (coupled or offline) to have a better representation of the hydrological cycle. All these models typically have a common implementation of the energy and water balance in the soil, known as the Land Surface Model (LSM). In general, a standard soil configuration with a depth of no more than 4 meters is used in all LSMs that are commonly implemented in GCMs, RCMs and HLSMs. For moderate climate conditions, this depth is sufficient to capture the intra-annual variability in the energy and water balance. However, for cold regions and for long-term simulations, deeper subsurface layers are needed in order to allow the heat signal to propagate through the soil to deeper layers and hence to avoid erroneous near-surface states and fluxes. Deeper soil/rock configurations create longer system memories, and as such, particular care should be taken to define the initial conditions for the subsurface system. In this work we perform a sensitivity analysis of the main factors that affect the subsurface energy and water balance for LSMs in cold regions - depth of soil, soil parameters, initial conditions and climate conditions for a warm-up period. We implement a 1D model using the Canadian Land Surface Scheme (CLASS) LSM for a study area in northern Canada where measurements of soil temperature profiles are available. Results suggest that an adequate representation of the heat propagation process in the soil requires the simulation of a soil depth of greater than 25 meters. As for initial conditions we recommend to spin-up over a cycle of an average climate year and then use reconstructed climate time series with a length of more than 300 years.

  17. Hydrogen production profiles using furans in microbial electrolysis cells.

    Science.gov (United States)

    Catal, Tunc; Gover, Tansu; Yaman, Bugra; Droguetti, Jessica; Yilancioglu, Kaan

    2017-06-01

    Microbial electrochemical cells including microbial fuel cells (MFCs) and microbial electrolysis cells (MECs) are novel biotechnological tools that can convert organic substances in wastewater or biomass into electricity or hydrogen. Electroactive microbial biofilms used in this technology have ability to transfer electrons from organic compounds to anodes. Evaluation of biofilm formation on anode is crucial for enhancing our understanding of hydrogen generation in terms of substrate utilization by microorganisms. In this study, furfural and hydroxymethylfurfural (HMF) were analyzed for hydrogen generation using single chamber membrane-free MECs (17 mL), and anode biofilms were also examined. MECs were inoculated with mixed bacterial culture enriched using chloroethane sulphonate. Hydrogen was succesfully produced in the presence of HMF, but not furfural. MECs generated similar current densities (5.9 and 6 mA/cm 2 furfural and HMF, respectively). Biofilm samples obtained on the 24th and 40th day of cultivation using aromatic compounds were evaluated by using epi-fluorescent microscope. Our results show a correlation between biofilm density and hydrogen generation in single chamber MECs.

  18. Depth-discrete Geochemical Profiling in Groundwater Using an Innovative In Situ Approach

    Science.gov (United States)

    Levison, J.; MacDonald, G.

    2014-12-01

    The presence of nitrate in groundwater is often associated with agricultural activity. Leaching below the root zone to aquifers from agricultural areas is a critical problem in many jurisdictions where concentrations are above drinking water guidelines. Traditionally, nitrate and other water quality parameters are collected using purge and sample techniques. Often this "snapshot" data both disrupts the natural subsurface flow system and is not detailed enough to determine critical water quality or quantity conditions. In this study, depth-discrete, continuous and in situ monitoring techniques are developed. While nitrate is the focus, parameters including temperature, dissolved oxygen (DO), turbidity, redox potential (ORP) and electrical conductivity (EC), are also monitored. Research sites examine a range of hydrogeological conditions from supply wells located in shallow, unconfined sandy aquifers (Norfolk County, Ontario, Canada) to fractured sedimentary bedrock aquifers (Guelph, Ontario) impacted by agricultural activity. The innovative groundwater quality sampling method uses the Submersible Ultraviolet Nitrate Analyzer (SUNATM) as well as the robust YSI EXO2 Water Quality SondeTM. Depth-discrete well profiling is used to evaluate vertical stratification of nitrate and field parameters along the entire borehole with a focus on the screened interval. The high resolution datasets show zones of changing water quality corresponding to different formations. In open bedrock boreholes in Guelph, distinct intervals were identified at different depths for pH, EC, DO and ORP. In the shallower wells in Norfolk County, increases in DO and EC along the screened interval suggest the presence of fresh groundwater representative of the aquifer, with potential implications for in situ long-term monitoring of groundwater parameters. Detailed profiles of DO and ORP at both sites can be combined with nitrate profile data to determine potential zones of denitrification. Water

  19. Three-Dimensional Mapping of Soil Organic Carbon by Combining Kriging Method with Profile Depth Function.

    Science.gov (United States)

    Chen, Chong; Hu, Kelin; Li, Hong; Yun, Anping; Li, Baoguo

    2015-01-01

    Understanding spatial variation of soil organic carbon (SOC) in three-dimensional direction is helpful for land use management. Due to the effect of profile depths and soil texture on vertical distribution of SOC, the stationary assumption for SOC cannot be met in the vertical direction. Therefore the three-dimensional (3D) ordinary kriging technique cannot be directly used to map the distribution of SOC at a regional scale. The objectives of this study were to map the 3D distribution of SOC at a regional scale by combining kriging method with the profile depth function of SOC (KPDF), and to explore the effects of soil texture and land use type on vertical distribution of SOC in a fluvial plain. A total of 605 samples were collected from 121 soil profiles (0.0 to 1.0 m, 0.20 m increment) in Quzhou County, China and SOC contents were determined for each soil sample. The KPDF method was used to obtain the 3D map of SOC at the county scale. The results showed that the exponential equation well described the vertical distribution of mean values of the SOC contents. The coefficients of determination, root mean squared error and mean prediction error between the measured and the predicted SOC contents were 0.52, 1.82 and -0.24 g kg(-1) respectively, suggesting that the KPDF method could be used to produce a 3D map of SOC content. The surface SOC contents were high in the mid-west and south regions, and low values lay in the southeast corner. The SOC contents showed significant positive correlations between the five different depths and the correlations of SOC contents were larger in adjacent layers than in non-adjacent layers. Soil texture and land use type had significant effects on the spatial distribution of SOC. The influence of land use type was more important than that of soil texture in the surface soil, and soil texture played a more important role in influencing the SOC levels for 0.2-0.4 m layer.

  20. Three-Dimensional Mapping of Soil Organic Carbon by Combining Kriging Method with Profile Depth Function.

    Directory of Open Access Journals (Sweden)

    Chong Chen

    Full Text Available Understanding spatial variation of soil organic carbon (SOC in three-dimensional direction is helpful for land use management. Due to the effect of profile depths and soil texture on vertical distribution of SOC, the stationary assumption for SOC cannot be met in the vertical direction. Therefore the three-dimensional (3D ordinary kriging technique cannot be directly used to map the distribution of SOC at a regional scale. The objectives of this study were to map the 3D distribution of SOC at a regional scale by combining kriging method with the profile depth function of SOC (KPDF, and to explore the effects of soil texture and land use type on vertical distribution of SOC in a fluvial plain. A total of 605 samples were collected from 121 soil profiles (0.0 to 1.0 m, 0.20 m increment in Quzhou County, China and SOC contents were determined for each soil sample. The KPDF method was used to obtain the 3D map of SOC at the county scale. The results showed that the exponential equation well described the vertical distribution of mean values of the SOC contents. The coefficients of determination, root mean squared error and mean prediction error between the measured and the predicted SOC contents were 0.52, 1.82 and -0.24 g kg(-1 respectively, suggesting that the KPDF method could be used to produce a 3D map of SOC content. The surface SOC contents were high in the mid-west and south regions, and low values lay in the southeast corner. The SOC contents showed significant positive correlations between the five different depths and the correlations of SOC contents were larger in adjacent layers than in non-adjacent layers. Soil texture and land use type had significant effects on the spatial distribution of SOC. The influence of land use type was more important than that of soil texture in the surface soil, and soil texture played a more important role in influencing the SOC levels for 0.2-0.4 m layer.

  1. Depth profile by Total IBA in perovskite active layers for solar cells

    Science.gov (United States)

    Barreiros, M. A.; Alves, L. C.; Brites, M. J.; Corregidor, V.

    2017-08-01

    In recent years the record efficiency of perovskite solar cells (PSCs) has been updated exceeding now 20%. However, it is difficult to make PSCs consistently. Definite correlation has been established between the PSC performance and the perovskite film quality which involves mainly morphology, crystallinity and composition. The manufacturing development of these devices is dependent on the characterisation methodologies, on the availability of suitable and reliable analytical techniques to assess the materials composition and quality and on the relationship of these results with the cell performance. Ion beam analytical (IBA) techniques jointly with a micro-ion beam are powerful tools for materials characterisation and can provide a valuable input for the knowledge of perovskite films. Perovskite films based on CH3NH3PbI3 were prepared (from CH3NH3I and PbI2 precursors) in a planar architecture and in a mesoporous TiO2 scaffold. Proton and helium micro-beams at different energies were used in the analysis of PSC active layers, previously characterised by SEM-FEG (Scanning Electron Microscopy with a field emission gun) and XRD (X-ray diffraction). Self-consistent fit of all the obtained PIXE (Particle Induced X-ray Emission) and RBS (Rutherford Backscattering Spectrometry) spectra through Total IBA approach provided depth profiling of perovskite, its precursors and TiO2 and assess their distribution in the films. PbI2 presence and location on the active layer may hinder the charge transport and highly affect the cell performance. IBA techniques allowed to identify regions of non-uniform surface coverage and homogeneous areas and it was possible to establish the undesired presence of PbI2 and its quantitative depth profile in the planar architecture film. In the mesostructured perovskite film it was verified a non-homogeneous distribution with a decreasing of perovskite concentration down to the thin blocking layer. The good agreement between the best fits obtained

  2. Determination of composition, residual stress and stacking fault depth profiles in expanded austenite with energy-dispersive diffraction

    DEFF Research Database (Denmark)

    Jegou, S.; Christiansen, Thomas Lundin; Klaus, M.

    2013-01-01

    A methodology is proposed combining the scattering vector method with energy dispersive diffraction for the non-destructive determination of stress- and composition-depth profiles. The advantage of the present method is a relatively short measurement time and avoidance of tedious sublayer removal......; the disadvantage as compared to destructive methods is that depth profiles can only be obtained for depth shallower than half the layer thickness. The proposed method is applied to an expanded austenite layer on stainless steel and allows the separation of stress, composition and stacking fault density gradients....

  3. Development of an ion time-of-flight spectrometer for neutron depth profiling

    Science.gov (United States)

    Cetiner, Mustafa Sacit

    Ion time-of-flight spectrometry techniques are investigated for applicability to neutron depth profiling. Time-of-flight techniques are used extensively in a wide range of scientific and technological applications including energy and mass spectroscopy. Neutron depth profiling is a near-surface analysis technique that gives concentration distribution versus depth for certain technologically important light elements. The technique uses thermal or sub-thermal neutrons to initiate (n, p) or (n, alpha) reactions. Concentration versus depth distribution is obtained by the transformation of the energy spectrum into depth distribution by using stopping force tables of the projectiles in the substrate, and by converting the number of counts into concentration using a standard sample of known dose value. Conventionally, neutron depth profiling measurements are based on charged particle spectrometry, which employs semiconductor detectors such as a surface barrier detector (SBD) and the associated electronics. Measurements with semiconductor detectors are affected by a number of broadening mechanisms, which result from the interactions between the projectile ion and the detector material as well as fluctuations in the signal generation process. These are inherent features of the detection mechanism that involve the semiconductor detectors and cannot be avoided. Ion time-of-flight spectrometry offers highly precise measurement capabilities, particularly for slow particles. For high-energy low-mass particles, measurement resolution tends to degrade with all other parameters fixed. The threshold for more precise ion energy measurements with respect to conventional techniques, such as direct energy measurement by a surface barrier detector, is directly related to the design and operating parameters of the device. Time-of-flight spectrometry involves correlated detection of two signals by a coincidence unit. In ion time-of-flight spectroscopy, the ion generates the primary input

  4. Groundwater flow estimation using temperature-depth profiles in a complex environment and a changing climate.

    Science.gov (United States)

    Irvine, Dylan J; Kurylyk, Barret L; Cartwright, Ian; Bonham, Mariah; Post, Vincent E A; Banks, Eddie W; Simmons, Craig T

    2017-01-01

    Obtaining reliable estimates of vertical groundwater flows remains a challenge but is of critical importance to the management of groundwater resources. When large scale land clearing or groundwater extraction occurs, methods based on water table fluctuations or water chemistry are unreliable. As an alternative, a number of methods based on temperature-depth (T-z) profiles are available to provide vertical groundwater flow estimates from which recharge rates may be calculated. However, methods that invoke steady state assumptions have been shown to be inappropriate for sites that have experienced land surface warming. Analytical solutions that account for surface warming are available, but they typically include unrealistic or restrictive assumptions (e.g. no flow initial conditions or linear surface warming). Here, we use a new analytical solution and associated computer program (FAST) that provides flexible initial and boundary conditions to estimate fluxes using T-z profiles from the Willunga Super Science Site, a complex, but densely instrumented groundwater catchment in South Australia. T-z profiles from seven wells (ranging from high elevation to near sea level) were utilised, in addition to mean annual air temperatures at nearby weather stations to estimate boundary conditions, and thermal properties were estimated from down borehole geophysics. Temperature based flux estimates were 5 to 23mmy-1, which are similar to those estimated using chloride mass balance. This study illustrates that T-z profiles can be studied to estimate recharge in environments where more commonly applied methods fail. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. In-air fluence profiles and water depth dose for uncollimated electron beams

    Science.gov (United States)

    Toutaoui, Abedelkadar; Aichouche, Amar Nassim; Adjidir, Kenza Adjidir; Chami, Ahmed Chafik

    2008-01-01

    Advanced electron beam dose calculation models for radiation treatment planning systems require the input of a phase space beam model to configure a clinical electron beam in a computer. This beam model is a distribution in position, energy, and direction of electrons and photons in a plane in front of the patient. The phase space beam model can be determined by Monte Carlo simulation of the treatment head or from a limited set of measurements. In the latter case, parameters of the electron phase space beam model are obtained by fitting measured to calculated dosimetric data. In the present work, data for air fluence profiles and water depth doses have been presented for electron beams without an applicator for a medical linear accelerator. These data are used to parameterize the electron phase space beam model to a Monte Carlo dose calculation module available in the first commercial (MDS Nordion, now Nucletron) Monte Carlo treatment planning for electron beams. PMID:19893707

  6. Microbial Community Dynamics in Soil Depth Profiles Over 120,000 Years of Ecosystem Development

    Directory of Open Access Journals (Sweden)

    Stephanie Turner

    2017-05-01

    Full Text Available Along a long-term ecosystem development gradient, soil nutrient contents and mineralogical properties change, therefore probably altering soil microbial communities. However, knowledge about the dynamics of soil microbial communities during long-term ecosystem development including progressive and retrogressive stages is limited, especially in mineral soils. Therefore, microbial abundances (quantitative PCR and community composition (pyrosequencing as well as their controlling soil properties were investigated in soil depth profiles along the 120,000 years old Franz Josef chronosequence (New Zealand. Additionally, in a microcosm incubation experiment the effects of particular soil properties, i.e., soil age, soil organic matter fraction (mineral-associated vs. particulate, O2 status, and carbon and phosphorus additions, on microbial abundances (quantitative PCR and community patterns (T-RFLP were analyzed. The archaeal to bacterial abundance ratio not only increased with soil depth but also with soil age along the chronosequence, coinciding with mineralogical changes and increasing phosphorus limitation. Results of the incubation experiment indicated that archaeal abundances were less impacted by the tested soil parameters compared to Bacteria suggesting that Archaea may better cope with mineral-induced substrate restrictions in subsoils and older soils. Instead, archaeal communities showed a soil age-related compositional shift with the Bathyarchaeota, that were frequently detected in nutrient-poor, low-energy environments, being dominant at the oldest site. However, bacterial communities remained stable with ongoing soil development. In contrast to the abundances, the archaeal compositional shift was associated with the mineralogical gradient. Our study revealed, that archaeal and bacterial communities in whole soil profiles are differently affected by long-term soil development with archaeal communities probably being better adapted to

  7. Historical Tracking of Nitrate in Contrasting Vineyard Using Water Isotopes and Nitrate Depth Profiles

    Science.gov (United States)

    Sprenger, M.; Erhardt, M.; Riedel, M.; Weiler, M.

    2015-12-01

    The European Water Framework Directive (EWFD) aims to achieve a good chemical status for the groundwater bodies in Europe by the year 2015. Despite the effort to reduce the nitrate pollution from agriculture within the last two decades, there are still many groundwater aquifers that exceed nitrate concentrations above the EWFD threshold of 50 mg/l. Viticulture is seen as a major contributor of nitrate leaching and sowing of a green cover was shown to have a positive effect on lowering the nitrate loads in the upper 90 cm of the soil. However, the consequences for nitrate leaching into the subsoil were not yet tested. We analyzed the nitrate concentrations and pore water stable isotope composition to a depth of 380 cm in soil profiles under an old vineyard and a young vineyard with either soil tillage or permanent green cover in between the grapevines. The pore water stable isotopes were used to calibrate a soil physical model, which was then used to infer the age of the soil water at different depths. This way, we could relate elevated nitrate concentrations below an old vineyard to tillage processes that took place during the winter two years before the sampling. We further showed that the elevated nitrate concentration in the subsoil of a young vineyard can be related to the soil tillage prior to the planting of the new vineyard. If the soil is kept bare due to tillage, a nitrate concentration of 200 kg NO3--N/ha is found in 290 to 380 cm depth 2.5 years after the installation of the vineyard. The amount of nitrate leaching is considerably reduced due to a seeded green cover between the grapevines that takes up a high share of the mobilized nitrate reducing a potential contamination of the groundwater.

  8. Thermal depth profiling of vascular lesions: automated regularization of reconstruction algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Verkruysse, Wim; Choi, Bernard; Zhang, Jenny R; Kim, Jeehyun; Nelson, J Stuart [Beckman Laser Institute and Medical Clinic, University of California, Irvine, CA 92612 (United States)], E-mail: wverkruy@uci.edu

    2008-03-07

    Pulsed photo-thermal radiometry (PPTR) is a non-invasive, non-contact diagnostic technique used to locate cutaneous chromophores such as melanin (epidermis) and hemoglobin (vascular structures). Clinical utility of PPTR is limited because it typically requires trained user intervention to regularize the inversion solution. Herein, the feasibility of automated regularization was studied. A second objective of this study was to depart from modeling port wine stain PWS, a vascular skin lesion frequently studied with PPTR, as strictly layered structures since this may influence conclusions regarding PPTR reconstruction quality. Average blood vessel depths, diameters and densities derived from histology of 30 PWS patients were used to generate 15 randomized lesion geometries for which we simulated PPTR signals. Reconstruction accuracy for subjective regularization was compared with that for automated regularization methods. The objective regularization approach performed better. However, the average difference was much smaller than the variation between the 15 simulated profiles. Reconstruction quality depended more on the actual profile to be reconstructed than on the reconstruction algorithm or regularization method. Similar, or better, accuracy reconstructions can be achieved with an automated regularization procedure which enhances prospects for user friendly implementation of PPTR to optimize laser therapy on an individual patient basis.

  9. Quantitative reconstruction of the GDOES sputter depth profile of a monomolecular layer structure of thiourea on copper

    Science.gov (United States)

    Liu, Y.; Jian, W.; Wang, J. Y.; Hofmann, S.; Shimizu, K.

    2015-03-01

    High-resolution depth profiles of a thiourea (CH4N2S) molecular monolayer on a copper substrate obtained by radio frequency glow discharge optical emission spectroscopy (rf-GDOES) are quantified by the Mixing-Roughness-Information depth (MRI) model. Based on the molecular structure of the self-assembled thiourea layer, the measured intensity-sputtering time profiles of N, S, C and Cu are fitted to the MRI model results with an appropriate depth resolution function. The sputtering rate is determined accordingly, using two different approaches based on constant sputtering rate and on composition dependent sputtering rate. While the first approach requires an additional background for a fairly acceptable solution, the approach using a newly developed multielement dependent sputtering rate results in a complete and consistent reconstruction of all the measured elemental depth profiles. It is demonstrated that for depth profiling of the first few monolayers with rf-GDOES, the depth resolution Δz can be as low as 0.5 nm, which is of the order of the theoretical limit.

  10. High resolution measurements and modeling of auroral hydrogen emission line profiles

    Directory of Open Access Journals (Sweden)

    B. S. Lanchester

    2003-07-01

    Full Text Available Measurements in the visible wavelength range at high spectral resolution (1.3 Å have been made at Longyearbyen, Svalbard (15.8 E,78.2 N during an interval of intense proton precipitation. The shape and Doppler shift of hydrogen Balmer beta line profiles have been compared with model line profiles, using as input ion energy spectra from almost coincident passes of the FAST and DMSP spacecraft. The comparison shows that the simulation contains the important physical processes that produce the profiles, and confirms that measured changes in the shape and peak wave-length of the hydrogen profiles are the result of changing energy input. This combination of high resolution measurements with modeling provides a method of estimating the incoming energy and changes in flux of precipitating protons over Svalbard, for given energy and pitch-angle distributions. Whereas for electron precipitation, information on the incident particles is derived from brightness and brightness ratios which require at least two spectral windows, for proton precipitation the Doppler profile of resulting hydrogen emission is directly related to the energy and energy flux of the incident energetic protons and can be used to gather information about the source region. As well as the expected Doppler shift to shorter wavelengths, the measured profiles have a significant red-shifted component, the result of upward flowing emitting hydrogen atoms.Key words. Ionosphere (auroral ionosphere; particle precipitation – Magnetospheric physics (auroral phenomena

  11. Molecular depth profiling of organic photovoltaic heterojunction layers by ToF-SIMS: comparative evaluation of three sputtering beams.

    Science.gov (United States)

    Mouhib, T; Poleunis, C; Wehbe, N; Michels, J J; Galagan, Y; Houssiau, L; Bertrand, P; Delcorte, A

    2013-11-21

    With the recent developments in secondary ion mass spectrometry (SIMS), it is now possible to obtain molecular depth profiles and 3D molecular images of organic thin films, i.e. SIMS depth profiles where the molecular information of the mass spectrum is retained through the sputtering of the sample. Several approaches have been proposed for "damageless" profiling, including the sputtering with SF5(+) and C60(+) clusters, low energy Cs(+) ions and, more recently, large noble gas clusters (Ar500-5000(+)). In this article, we evaluate the merits of these different approaches for the in depth analysis of organic photovoltaic heterojunctions involving poly(3-hexylthiophene) (P3HT) as the electron donor and [6,6]-phenyl C61 butyric acid methyl ester (PCBM) as the acceptor. It is demonstrated that the use of 30 keV C60(3+) and 500 eV Cs(+) (500 eV per atom) leads to strong artifacts for layers in which the fullerene derivative PCBM is involved, related to crosslinking and topography development. In comparison, the profiles obtained using 10 keV Ar1700(+) (∼6 eV per atom) do not indicate any sign of artifacts and reveal fine compositional details in the blends. However, increasing the energy of the Ar cluster beam beyond that value leads to irreversible damage and failure of the molecular depth profiling. The profile qualities, apparent interface widths and sputtering yields are analyzed in detail. On the grounds of these experiments and recent molecular dynamics simulations, the discussion addresses the issues of damage and crater formation induced by the sputtering and the analysis ions in such radiation-sensitive materials, and their effects on the profile quality and the depth resolution. Solutions are proposed to optimize the depth resolution using either large Ar clusters or low energy cesium projectiles for sputtering and/or analysis.

  12. Project Profile: Hydrogen Fuel Cell Mobile Lighting Tower (HFCML)

    Science.gov (United States)

    McLaughlin, Russell

    2013-01-01

    NASA is committed to finding innovative solutions that improve the operational performance of ground support equipment while providing environment and cost benefits, as well. Through the Hydrogen Fuel Cell Mobile Lighting Tower (HFCML) project, NASA gained operational exposure to a novel application of high efficiency technologies. Traditionally, outdoor lighting and auxiliary power at security gates, launch viewing sites, fallback areas, outage support, and special events is provided by diesel generators with metal halide lights. Diesel generators inherently contribute to C02, NOx, particulate emissions, and are very noisy. In 2010, engineers from NASA's Technology Evaluation for Environmental Risk Mitigation Principal Center (TEERM) introduced KSC operations to a novel technology for outdoor lighting needs. Developed by a team led by Sandia National Laboratory (SNL), the technology pairs a 5kW hydrogen fuel cell with robust high efficiency plasma lights in a towable trailer. Increased efficiency, in both the fuel cell power source and lighting load, yields longer run times between fueling operations while providing greater auxiliary power. Because of the unit's quiet operation and no exhaust fumes, it is capable of being used indoors and in emergency situations, and meets the needs of all other operational roles for metal halide/diesel generators. The only discharge is some water and warm air. Environmental benefits include elimination of diesel particulate emissions and estimated 73% greenhouse gas emissions savings when the hydrogen source is natural gas (per GREET model). As the technology matures the costs could become competitive for the fuel cell units which are approximately 5 times diesel units. Initial operational . concerns included the hydrogen storage tanks and valves, lightning safety/grounding, and required operating and refueling procedures. TEERM facilitated technical information exchange (design drawings, technical standards, and operations

  13. Empirical Profiling of Cold Hydrogen Plumes Formed from Venting Of LH2 Storage Vessels: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Buttner, William J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rivkin, Carl H [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Schmidt, Kara [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hartmann, Kevin S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Wright, Hannah [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Weidner, Eveline [Joint Research Centre, Petten, the Netherlands; Ciotti, Michael [H2 Fueling and CIP Markets Engineering

    2017-11-16

    Liquid hydrogen (LH2) storage is a viable approach to assuring sufficient hydrogen capacity at commercial fuelling stations. Presently, LH2 is produced at remote facilities and then transported to the end-use site by road vehicles (i.e., LH2 tanker trucks). Venting of hydrogen to depressurize the transport storage tank is a routine part of the LH2 delivery process. The behaviour of cold hydrogen plumes has not been well-characterized because empirical field data is essentially non-existent. The NFPA 2 Hydrogen Storage Safety Task Group, which consists of hydrogen producers, safety experts, and CFD modellers, has identified the lack of understanding of hydrogen dispersion during LH2 venting of storage vessel as a critical gap for establishing safety distances at LH2 facilities, especially commercial hydrogen fuelling stations. To address this need, the NREL sensor laboratory, in collaboration with the NFPA 2 Safety Task Group developed the Cold Hydrogen Plume Analyzer to empirically characterize the hydrogen plume formed during LH2 storage tank venting. A prototype Analyzer was developed and field-deployed at an actual LH2 venting operation with critical findings that included: - H2 being detected as much as 2 m lower than the release point, which is not predicted by existing models - A small and inconsistent correlation between oxygen depletion and the hydrogen concentration - A negligible to non-existent correlation between in-situ temperature and the hydrogen concentration The Analyzer is currently being upgraded for enhanced metrological capabilities including improved real-time spatial and temporal profiling of the plume and tracking of prevailing weather conditions. Additional deployments are planned to monitor plume behaviour under different wind, humidity, and temperatures. This data will be shared with the NFPA 2 Safety Task Group and ultimately will be used support theoretical models and code requirements prescribed in NFPA 2.

  14. Depth profiling of oxide-trapped charges in 6H-SiC MOS structures by slant etching method

    Energy Technology Data Exchange (ETDEWEB)

    Saitoh, Kazunari; Takahashi, Yoshihiro; Ohnishi, Kazunori [Nihon Univ., Tokyo (Japan). Coll. of Science and Technology; Yoshikawa, Masahito; Ohshima, Takeshi; Itoh, Hisayoshi; Nashiyama, Isamu

    1997-03-01

    In this paper, we propose a method to evaluate the depth profile of trapped charges in an oxide layer on SiC. Using this method, 6H-SiC MOS structures with different oxide thickness were fabricated on the same substrate under the same oxidation condition, and the depth profile of oxide-trapped charges before and after {sup 60}Co-gamma ray irradiation were obtained. It is found, from the depth profiling, that the trapping mechanism of electrons and holes in the oxide strongly depends on the bias polarity during irradiation, and these charges are trapped near 6H-SiC/SiO{sub 2} interface. We believe that this method is very useful for estimation of the oxide-trapped charges in 6H-SiC MOS structures. (author)

  15. Determination of rare earth elements concentration at different depth profile of Precambrian pegmatites using instrumental neutron activation analysis.

    Science.gov (United States)

    Sadiq Aliyu, Abubakar; Musa, Yahaya; Liman, M S; Abba, Habu T; Chaanda, Mohammed S; Ngene, Nnamani C; Garba, N N

    2018-01-01

    The Keffi area hosts abundant pegmatite bodies as a result of the surrounding granitic intrusions. Keffi is part of areas that are geologically classified as North Central Basement Complex. Data on the mineralogy and mineralogical zonation of the Keffi pegmatite are scanty. Hence the need to understand the geology and mineralogical zonation of Keffi pegmatites especially at different depth profiles is relevant as a study of the elemental composition of the pegmatite is essential for the estimation of its economic viability. Here, the relative standardization method of instrumental neutron activation analysis (INAA) has been used to investigate the vertical deviations of the elemental concentrations of rare earth elements (REEs) at different depth profile of Keffi pegmatite. This study adopted the following metrics in investigating the vertical variations of REEs concentrations. Namely, the total contents of rare earth elements (∑REE); ratio of light to heavy rare earth elements (LREE/HREE), which defines the enrichment or depletion of REEs; europium anomaly (Eu/Sm); La/Lu ratio relative to chondritic meteorites. The study showed no significant variations in the total content of rare elements between the vertical depth profiles (100-250m). However, higher total concentrations of REEs (~ 92.65ppm) were recorded at the upper depth of the pegmatite and the europium anomaly was consistently negative at all the depth profiles suggesting that the Keffi pegmatite is enriched with light REEs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Structural and magnetic depth profiles of magneto-ionic heterostructures beyond the interface limit

    Energy Technology Data Exchange (ETDEWEB)

    Gilbert, DA; Grutter, AJ; Arenholz, E; Liu, K; Kirby, BJ; Borchers, JA; Maranville, BB

    2016-07-22

    Electric field control of magnetism provides a promising route towards ultralow power information storage and sensor technologies. The effects of magneto-ionic motion have been prominently featured in the modification of interface characteristics. Here, we demonstrate magnetoelectric coupling moderated by voltage-driven oxygen migration beyond the interface in relatively thick AlOx/GdOx/Co(15 nm) films. Oxygen migration and Co magnetization are quantitatively mapped with polarized neutron reflectometry under electro-thermal conditioning. The depth-resolved profiles uniquely identify interfacial and bulk behaviours and a semi-reversible control of the magnetization. Magnetometry measurements suggest changes in the microstructure which disrupt long-range ferromagnetic ordering, resulting in an additional magnetically soft phase. X-ray spectroscopy confirms changes in the Co oxidation state, but not in the Gd, suggesting that the GdOx transmits oxygen but does not source or sink it. These results together provide crucial insight into controlling magnetism via magneto-ionic motion, both at interfaces and throughout the bulk of the films.

  17. Depth Profiling (ICP-MS Study of Toxic Metal Buildup in Concrete Matrices: Potential Environmental Impact

    Directory of Open Access Journals (Sweden)

    Ghada Bassioni

    2010-10-01

    Full Text Available This paper explores the potential of concrete material to accumulate toxic trace elements using ablative laser technology (ICP-MS. Concrete existing in offshore structures submerged in seawater acts as a sink for hazardous metals, which could be gradually released into the ocean creating pollution and anoxic conditions for marine life. Ablative laser technology is a valuable tool for depth profiling concrete to evaluate the distribution of toxic metals and locate internal areas where such metals accumulate. Upon rapid degradation of concrete these “hotspots” could be suddenly released, thus posing a distinct threat to aquatic life. Our work simulated offshore drilling conditions by immersing concrete blocks in seawater and investigating accumulated toxic trace metals (As, Be, Cd, Hg, Os, Pb in cored samples by laser ablation. The experimental results showed distinct inhomogeneity in metal distribution. The data suggest that conditions within the concrete structure are favorable for random metal accumulation at certain points. The exact mechanism for this behavior is not clear at this stage and has considerable scope for extended research including modeling and remedial studies.

  18. Molecular depth profiling in ice matrices using C{sub 60} projectiles

    Energy Technology Data Exchange (ETDEWEB)

    Wucher, A.; Sun, S.; Szakal, C.; Winograd, N

    2004-06-15

    The prospects of molecular sputter depth profiling using C{sub 60}{sup +} projectiles were investigated on thick ice layers prepared by freezing aqueous solutions of histamine onto a metal substrate. The samples were analyzed in a ToF-SIMS spectrometer equipped with a liquid metal Ga{sup +} ion source and a newly developed fullerene ion source. The C{sub 60}{sup +} beam was used to erode the surface, while static ToF-SIMS spectra were taken with both ion beams alternatively between sputtering cycles. We find that the signals both related to the ice matrix and to the histamine are about two orders of magnitude higher under 20-keV C{sub 60} than under 15-keV Ga bombardment. Histamine related molecular signals are found to increase drastically if the freshly introduced surface is pre-sputtered with C{sub 60} ions, until at a total ion fluence of about 10{sup 13} cm{sup -2} the spectra are completely dominated by the molecular ion and characteristic fragments of histamine. At larger fluence, the signal is found to decrease with a disappearance cross section of approximately 10{sup -14} cm{sup 2}, until at total fluences of about 10{sup 14} cm{sup -2} a steady state with stable molecular signals is reached. In contrast, no appreciable molecular signal could be observed if Ga{sup +} ions were used to erode the surface.

  19. Structural and magnetic depth profiles of magneto-ionic heterostructures beyond the interface limit.

    Science.gov (United States)

    Gilbert, Dustin A; Grutter, Alexander J; Arenholz, Elke; Liu, Kai; Kirby, B J; Borchers, Julie A; Maranville, Brian B

    2016-07-22

    Electric field control of magnetism provides a promising route towards ultralow power information storage and sensor technologies. The effects of magneto-ionic motion have been prominently featured in the modification of interface characteristics. Here, we demonstrate magnetoelectric coupling moderated by voltage-driven oxygen migration beyond the interface in relatively thick AlOx/GdOx/Co(15 nm) films. Oxygen migration and Co magnetization are quantitatively mapped with polarized neutron reflectometry under electro-thermal conditioning. The depth-resolved profiles uniquely identify interfacial and bulk behaviours and a semi-reversible control of the magnetization. Magnetometry measurements suggest changes in the microstructure which disrupt long-range ferromagnetic ordering, resulting in an additional magnetically soft phase. X-ray spectroscopy confirms changes in the Co oxidation state, but not in the Gd, suggesting that the GdOx transmits oxygen but does not source or sink it. These results together provide crucial insight into controlling magnetism via magneto-ionic motion, both at interfaces and throughout the bulk of the films.

  20. Observations from a 4-Year Contamination Study of a Sample Depth Profile Through Martian Meteorite Nakhla

    Science.gov (United States)

    Toporski,Jan; Steele, Andrew

    2007-05-01

    Morphological, compositional, and biological evidence indicates the presence of numerous well-developed microbial hyphae structures distributed within four different sample splits of the Nakhla meteorite obtained from the British Museum (allocation BM1913,25). By examining depth profiles of the sample splits over time, morphological changes displayed by the structures were documented, as well as changes in their distribution on the samples, observations that indicate growth, decay, and reproduction of individual microorganisms. Biological staining with DNA-specific molecular dyes followed by epifluorescence microscopy showed that the hyphae structures contain DNA. Our observations demonstrate the potential of microbial interaction with extraterrestrial materials, emphasize the need for rapid investigation of Mars return samples as well as any other returned or impactor-delivered extraterrestrial materials, and suggest the identification of appropriate storage conditions that should be followed immediately after samples retrieved from the field are received by a handling/curation facility. The observations are further relevant in planetary protection considerations as they demonstrate that microorganisms may endure and reproduce in extraterrestrial materials over long (at least 4 years) time spans. The combination of microscopy images coupled with compositional and molecular staining techniques is proposed as a valid method for detection of life forms in martian materials as a first-order assessment. Time-resolved in situ observations further allow observation of possible (bio)dynamics within the system.

  1. Prediction of euphotic depths and diffuse attenuation coefficients from absorption profiles: a model based on comparisons between vertical profiles of spectral absorption, spectral irradiance, and P

    Science.gov (United States)

    Zaneveld, J. Ronald V.; Pegau, Scott; Barnard, Andrew H.; Mueller, James L.; Maske, Helmut; Valdez, Eduardo; Lara-Lara, Ruben; Alvarez-Borrego, Saul

    1997-02-01

    A model is presented which predicts the diffuse attenuation coefficient of downwelling irradiance as a function of depth and the depth of the euphotic zone as based on the one percent level of photosynthetically active radiation from vertical profiles of spectral absorption and attenuation. The model is tested using data obtained in the Gulf of California. The modeled diffuse attenuation coefficients and PAR levels ar shown to have average errors of less than five percent when compared to the measured values.

  2. Organosulphide profile and hydrogen sulphide-releasing activity of garlic fermented by Lactobacillus plantarum

    NARCIS (Netherlands)

    Tocmo, Restituto; Lai, Abigail Nianci; Wu, Yuchen; Liang, Dong; Fogliano, Vincenzo; Huang, Dejian

    2017-01-01

    Blanched and unblanched garlic were fermented using L. plantarum for investigation of organosulphide profiles, hydrogen sulphide-releasing activity, pH, titratable activity and microbial growth. Both raw and blanched garlic preparations allowed growth of L. plantarum with corresponding lowering of

  3. Backside and frontside depth profiling of B delta doping, at low energy, using new and previous magnetic SIMS instruments

    Energy Technology Data Exchange (ETDEWEB)

    Laugier, F.; Hartmann, J.M.; Moriceau, H.; Holliger, P.; Truche, R.; Dupuy, J.C

    2004-06-15

    A sample, composed of inverted boron deltas/SiO{sub 2}/boron deltas/silicon on an insulator substrate (SOI), was analyzed using a Cameca IMS 5f and a Cameca IMS Wf, with 500 eV O{sub 2}{sup +}, oxygen flooding, and an electron gun. To synthesize this 'double delta doping' sample, two identical boron multi-deltas were grown on SOI wafers and molecularly bonded upside down, then one SOI substrate was removed. The quality of this sample was checked by TEM and AFM. From the boron deltas' SIMS depth profiles, a comparative study of the two SIMS instruments was carried out by looking in detail at the depth resolution parameters. It was found that depth profiles acquired with both tools are very similar to those measured by TEM. Both tools separate B deltas 2 nm apart. However, the primary beam density is higher with the IMS Wf, allowing a two times faster analysis time than with the IMS 5f. This sample structure also allowed us to acquire in one measurement both the backside and the conventional front side depth profiles, therefore allowing the contribution from both the epitaxial growth and the contribution from the instrumental SIMS profiling conditions to be separated.

  4. High-resolution hydrogen profiling in AlGaN/GaN heterostructures grown by different epitaxial methods

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Posada Flores, F; Redondo-Cubero, A; Bengoechea, A; Brana, A F; Munoz, E [Instituto de Sistemas Optoelectronicos y Microtecnologia (ISOM) and Dpto. IngenierIa Electronica (DIE), ETSI de Telecomunicacion, Universidad Politecnica de Madrid, E-28040 Madrid (Spain); Gago, R [Centro de Micro-Analisis de Materiales, Universidad Autonoma de Madrid, E-28049 Madrid (Spain); Jimenez, A [Dpto. Electronica, Escuela Politecnica Superior, Universidad de Alcala, E-28805 Alcala de Henares, Madrid (Spain); Grambole, D, E-mail: fposada@die.upm.e [Institute of Ion Beam Physics and Materials Research, Forschungszentrum Dresden-Rossendorf, PF 51019, D-01314 Dresden (Germany)

    2009-03-07

    Hydrogen (H) incorporation into AlGaN/GaN heterostructures used in high electron mobility transistors, grown by different methods, is studied by high-resolution depth profiling. Samples grown on sapphire and Si(1 1 1) substrates by molecular-beam epitaxy and metal-organic vapour phase epitaxy; involving H-free and H-containing precursors, were analysed to evaluate the eventual incorporation of H into the wafer. The amount of H was measured by means of nuclear reaction analysis (NRA) using the {sup 1}H({sup 15}N,{alpha}{gamma}){sup 12}C reaction up to a depth of {approx}110 nm into the heterostructures. Interestingly, the H profiles are similar in all the samples analysed, with an increasing H content towards the surface and a negligible H incorporation into the GaN layer (0.24 {+-} 0.08 at%) or at the AlGaN/GaN interface. Therefore, NRA shows that H uptake is not related to the growth process or technique employed and that H contamination may be due to external sources after growth. The eventual correlation between topographical defects on the AlGaN surface and the H concentration are also discussed.

  5. Novel approach of signal normalization for depth profile of cultural heritage materials

    Science.gov (United States)

    Syvilay, D.; Detalle, V.; Wilkie-Chancellier, N.; Texier, A.; Martinez, L.; Serfaty, S.

    2017-01-01

    The investigation of cultural heritage materials is always complex and specific because unique. Materials are most often heterogeneous and organized in several layers such as mural paintings or corrosion products. The characterization of a complete artwork's stratigraphy is actually one of the questions of science conservation. Indeed, the knowledge of these layers allows completing the history of the work of art and a better understanding of alteration processes in order to set up an appropriate conservation action. The LIBS technique has been employed to study the stratigraphy of an artwork thanks to the ablation laser. However, as we know, atomic information could be insufficient to characterize two materials composed by the same based elements. Therefore, an additional molecular analysis, like Raman spectroscopy; is sometimes necessary for a better identification of the material in particular for organic coatings in cultural heritage. We suggest in this study to use Standard Normal Variate (SNV) as a common normalization for different kinds of spectra (LIBS and Raman spectroscopy) combined with a 3D colour representation for stratigraphic identification of the different layers composing the complex material from artwork. So in this investigation, the SNV method will be applied on LIBS and Raman spectra but also on baseline Raman spectra often considering as nuisance. The aim of this study is to demonstrate the versatility of SNV applied on varied spectra like LIBS, Raman spectra as well as the luminescence background. This original work considers the SNV with a 3D colour representation as a probable new perspective for an easy recognition of a structure layered with a direct overview of the depth profile of the artwork.

  6. Morphological characterization and AES depth profile analysis of CuInS{sub 2} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Calderon, C.; Oyola, J.S.; Gordillo, G. [Departamento de Fisica, Universidad Nacional de Colombia, Bogota (Colombia); Bartolo-Perez, P. [Departamento de Fisica Aplicada, CINVESTAV-IPN, Merida, Yucatan (Mexico); Clavijo, J. [Departamento de Quimica, Universidad Nacional de Colombia, Bogota (Colombia)

    2010-01-15

    This work presents results regarding the influence of preparation conditions on the morphological properties and on the chemical composition homogeneity of CuInS{sub 2} (CIS) thin films, grown by a chemical reaction of the precursor species evaporated sequentially on a soda-lime glass substrate, in a two- or three-stage process. The CIS samples were characterized using atomic force microscopy (AFM), scanning electron microscopy (SEM) and Auger electron spectroscopy (AES) depth profile measurements. The results showed that the deposition process and the ratio (evaporated Cu/evaporated In) affect the homogeneity of the chemical composition of the CIS film as well as the grain size. It was found that the samples grown in two stages are inhomogeneous in chemical composition and also Cu-rich near the film surface, probably due to the formation of a secondary Cu{sub 2}S phase in the surface region. The results also revealed that adding a third step in the deposition process improved the homogeneity in the chemical composition of CIS films and helped to remove the Cu{sub 2}S surface layer. The chemical composition of the samples deposited in a three-stage process is homogeneous in the whole volume, whereas the chemical composition in the bulk of samples deposited in a two-stage process is significantly different to that measured in the surface region. CIS films with characteristics found for the former case have demonstrated good properties for its use as absorber layers in thin film solar cells. (author)

  7. Depth profile characterization of Zn-TiO2 nanocomposite films by pulsed radiofrequency glow discharge-optical emission spectrometry.

    Science.gov (United States)

    Alberts, Deborah; Fernández, Beatriz; Frade, Tania; Gomes, Anabela; Pereira, Maria Isabel da Silva; Pereiro, Rosario; Sanz-Medel, Alfredo

    2011-04-15

    In recent years particular effort is being devoted towards the development of radiofrequency (rf) pulsed glow discharges (GDs) coupled to optical emission spectrometry (OES) for depth profile analysis of materials with technological interest. In this work, pulsed rf-GD-OES is investigated for the fast and sensitive depth characterization of Zn-TiO(2) nanocomposite films deposited on conductive substrates (Ti and steel). The first part of this work focuses on assessing the advantages of pulsed GDs, in comparison with the continuous GD, in terms of analytical emission intensities and emission yields. Next, the capability of pulsed rf-GD-OES for determination of thickness and compositional depth profiles is demonstrated by resorting to a simple multi-matrix calibration procedure. A rf forward power of 75 W, a pressure of 600 Pa, 10 kHz pulse frequency and 50% duty cycle were selected as GD operation parameters.Quantitative depth profiles obtained with the GD proposed methodology for Zn-TiO(2) nanocomposite films, prepared by the occlusion electrodeposition method using pulsed reverse current electrolysis, have proved to be in good agreement with results achieved by complementary techniques, including scanning electron microscopy and inductively coupled plasma-mass spectrometry. The work carried out demonstrates that pulsed rf-GD-OES is a promising tool for the fast analytical characterization of nanocomposite films. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. The effects of the depth of web on the bending behaviour of triangular web profile steel beam section

    Science.gov (United States)

    De'nan, Fatimah; Keong, Choong Kok; Hashim, Nor Salwani

    2017-10-01

    Due to extensive usage of corrugated web in construction, this paper performs finite element analysis to investigate the web thickness effects on the bending behaviour of Triangular Web Profile (TRIWP) steel section. A TRIWP steel section which are consists two flanges attached to a triangular profile web plate. This paper analyzes two categories of TRIWP steel sections which are D×100×6×3 mm and D×75×5×2 mm. It was observed that for steel section D×100×6×3 mm (TRIWP1), the deflection about minor and major axis increased as the span length increased. Meanwhile, the deflection about major axis decreased when depth of the web increased. About minor axis, the deflection increased for 3m and 4m span, while the deflection at 4.8m decreased with increment the depth of web. However, when the depth of the web exceeds 250mm, deflection at 3m and 4m were increased. For steel section D×75×5×2 mm (TRIWP2), the result was different with TRIWP1 steel section, where the deflection in both major and minor directions increased with the increment of span length and decreased with increment the depth of web. It shows that the deflection increased proportionally with the depth of web. Therefore, deeper web should be more considered because it resulted in smaller deflection.

  9. Insights into biodegradation through depth-resolved microbial community functional and structural profiling of a crude-oil contaminant plume

    Science.gov (United States)

    Fahrenfeld, Nicole; Cozzarelli, Isabelle M.; Bailey, Zach; Pruden, Amy

    2014-01-01

    Small-scale geochemical gradients are a key feature of aquifer contaminant plumes, highlighting the need for functional and structural profiling of corresponding microbial communities on a similar scale. The purpose of this study was to characterize the microbial functional and structural diversity with depth across representative redox zones of a hydrocarbon plume and an adjacent wetland, at the Bemidji Oil Spill site. A combination of quantitative PCR, denaturing gradient gel electrophoresis, and pyrosequencing were applied to vertically sampled sediment cores. Levels of the methanogenic marker gene, methyl coenzyme-M reductase A (mcrA), increased with depth near the oil body center, but were variable with depth further downgradient. Benzoate degradation N (bzdN) hydrocarbon-degradation gene, common to facultatively anaerobic Azoarcus spp., was found at all locations, but was highest near the oil body center. Microbial community structural differences were observed across sediment cores, and bacterial classes containing known hydrocarbon degraders were found to be low in relative abundance. Depth-resolved functional and structural profiling revealed the strongest gradients in the iron-reducing zone, displaying the greatest variability with depth. This study provides important insight into biogeochemical characteristics in different regions of contaminant plumes, which will aid in improving models of contaminant fate and natural attenuation rates.

  10. SIMS as a new methodology to depth profile helium in as-implanted and annealed pure bcc metals?

    Energy Technology Data Exchange (ETDEWEB)

    Gorondy-Novak, S. [CEA, DEN, Service de Recherches de Métallurgie Physique, Université Paris-Saclay, F-91191 Gif-sur-Yvette (France); Jomard, F. [Groupe d' Etude de la Matière Condensée, CNRS, UVSQ, 45 avenue des Etats-Unis, 78035 Versailles cedex (France); Prima, F. [PSL Research University, Chimie ParisTech – CNRS, Institut de Recherche de Chimie Paris, 75005 Paris (France); Lefaix-Jeuland, H., E-mail: helene.lefaix@cea.fr [CEA, DEN, Service de Recherches de Métallurgie Physique, Université Paris-Saclay, F-91191 Gif-sur-Yvette (France)

    2017-05-01

    Reliable He profiles are highly desirable for better understanding helium behavior in materials for future nuclear applications. Recently, Secondary Ions Mass Spectrometry (SIMS) allowed the characterization of helium distribution in as-implanted metallic systems. The Cs{sup +} primary ion beam coupled with CsHe{sup +} molecular detector appeared to be a promising technique which overcomes the very high He ionization potential. In this study, {sup 4}He depth profiles in pure body centered cubic (bcc) metals (V, Fe, Ta, Nb and Mo) as-implanted and annealed, were obtained by SIMS. All as-implanted samples exhibited a projected range of around 200 nm, in agreement with SRIM theoretical calculations. After annealing treatment, SIMS measurements evidenced the evolution of helium depth profile with temperature. The latter SIMS results were compared to the helium bubble distribution obtained by Transmission Electron Microscopy (TEM). This study confirmed the great potential of this experimental procedure as a He-depth profiling technique in bcc metals. Indeed, the methodology described in this work could be extended to other materials including metallic and non-metallic compounds. Nevertheless, the quantification of helium concentration after annealing treatment by SIMS remains uncertain probably due to the non-uniform ionization efficiency in samples containing large bubbles.

  11. Optical measurement of static temperature and hydroxyl radical profiles in a hydrogen-fueled supersonic combustor

    Science.gov (United States)

    Gaugler, R. E.

    1974-01-01

    Profiles of static temperature and hydroxyl radical concentration were measured in a two-dimensional supersonic combustor test section 22.8 cm downstream of hydrogen injection. A high-pressure gas generator supplied vitiated air to the test section at Mach 2.44, atmospheric pressure, and a total temperature of about 2240 K. Room-temperature hydrogen was injected through a 0.40-cm step slot at Mach 1 and matched pressure. The measurements utilized a noninterfering spectral line absorption technique in which narrow ultraviolet emission lines of the hydroxyl electronic transition are absorbed by the broader absorption lines in the combustion gas. Comparison of the measured temperature profiles with theoretical calculations showed good agreement.

  12. Collecting optical coherence elastography depth profiles with a micromachined cantilever probe

    NARCIS (Netherlands)

    Chavan, D.C.; Mo, J.; de Groot, M.; Meijering, A.E.C.; de Boer, J.F.; Iannuzzi, D.

    2013-01-01

    We present an experimental setup that combines optical coherence elastography depth sensing with atomic force microscope indentation. The instrument relies on a miniaturized cantilever probe that compresses a sample with a small footprint force and simultaneously collects an optical coherence

  13. Depth-profile investigations of triterpenoid varnishes by KrF excimer laser ablation and laser-induced breakdown spectroscopy

    Science.gov (United States)

    Theodorakopoulos, C.; Zafiropulos, V.

    2009-07-01

    The ablation properties of aged triterpenoid dammar and mastic films were investigated using a Krypton Fluoride excimer laser (248 nm, 25 ns). Ablation rate variations between surface and bulk layers indicated changes of the ablation mechanisms across the depth profiles of the films. In particular, after removal of the uppermost surface varnish layers there was a reduction of the ablation step in the bulk that was in line with a significant reduction of carbon dimer emission beneath the surface layers as detected by laser-induced breakdown spectroscopy. The results are explicable by the generation of condensation, cross-linking and oxidative gradients across the depth profile of triterpenoid varnish films during the aging degradation process, which were recently quantified and established on the molecular level.

  14. Silver/oxygen depth profile in coins by using laser ablation, mass quadrupole spectrometer and X-rays fluorescence

    Science.gov (United States)

    Cutroneo, M.; Torrisi, L.; Caridi, F.; Sayed, R.; Gentile, C.; Mondio, G.; Serafino, T.; Castrizio, E. D.

    2013-05-01

    Silver coins belonging to different historical periods were investigated to determine the Ag/O atomic ratio depth profiles. Laser ablation has been employed to remove, in high vacuum, the first superficial layers of the coins. Mass quadrupole spectrometry has been used to detect the Ag and the O atomic elements vaporized from the coin surface. The depth profile allowed to determine the thickness of the oxidation layer indicating that, in general, it is high in old coins. A complementary technique, using scanning electron microscope and the associated XRF microprobe, have been devoted to confirm the measurements of Ag/O atomic ratio measured with the laser-coupled mass spectrometry. The oxidation layer thicknesses range between about 25 and 250 microns.

  15. Quantitative evaluation of sputtering induced surface roughness and its influence on AES depth profiles of polycrystalline Ni/Cu multilayer thin films

    Energy Technology Data Exchange (ETDEWEB)

    Yan, X.L.; Coetsee, E. [Department of Physics, University of the Free State, P O Box 339, Bloemfontein, ZA9300 (South Africa); Wang, J.Y., E-mail: wangjy@stu.edu.cn [Department of Physics, Shantou University, 243 Daxue Road, Shantou, 515063, Guangdong (China); Swart, H.C., E-mail: swartHC@ufs.ac.za [Department of Physics, University of the Free State, P O Box 339, Bloemfontein, ZA9300 (South Africa); Terblans, J.J., E-mail: terblansjj@ufs.ac.za [Department of Physics, University of the Free State, P O Box 339, Bloemfontein, ZA9300 (South Africa)

    2017-07-31

    Highlights: • Linear Least Square (LLS) method used to separate Ni and Cu Auger spectra. • The depth-dependent ion sputtering induced roughness was quantitatively evaluated. • The depth resolution better when profiling with dual-ion beam vs. a single-ion beam. • AES depth profiling with a lower ion energy results in a better depth resolution. - Abstract: The polycrystalline Ni/Cu multilayer thin films consisting of 8 alternating layers of Ni and Cu were deposited on a SiO{sub 2} substrate by means of electron beam evaporation in a high vacuum. Concentration-depth profiles of the as-deposited multilayered Ni/Cu thin films were determined with Auger electron spectroscopy (AES) in combination with Ar{sup +} ion sputtering, under various bombardment conditions with the samples been stationary as well as rotating in some cases. The Mixing-Roughness-Information depth (MRI) model used for the fittings of the concentration-depth profiles accounts for the interface broadening of the experimental depth profiling. The interface broadening incorporates the effects of atomic mixing, surface roughness and information depth of the Auger electrons. The roughness values extracted from the MRI model fitting of the depth profiling data agrees well with those measured by atomic force microscopy (AFM). The ion sputtering induced surface roughness during the depth profiling was accordingly quantitatively evaluated from the fitted MRI parameters with sample rotation and stationary conditions. The depth resolutions of the AES depth profiles were derived directly from the values determined by the fitting parameters in the MRI model.

  16. Investigating Surface and Interface Phenomena in LiFeBO3 Electrodes Using Photoelectron Spectroscopy Depth Profiling

    DEFF Research Database (Denmark)

    Maibach, Julia; Younesi, Reza; Schwarzburger, Nele

    2014-01-01

    The formation of surface and interface layers at the electrodes is highly important for the performance and stability of lithium ion batteries. To unravel the surface composition of electrode materials, photoelectron spectroscopy (PES) is highly suitable as it probes chemical surface and interface...... properties with high surface sensitivity. Additionally, by using synchrotron-generated hard x-rays as excitation source, larger probing depths compared to in-house PES can be achieved. Therefore, the combination of in-house soft x-ray photoelectron spectroscopy and hard x-ray photoelectron spectroscopy...... (HAXPES) enables reliable and non-destructive depth profiling. Thus, detailed investigation of compositional gradients at electrode surfaces and interfaces from a sub-monolayer to several nanometer length scales can be performed. As this depth region is especially relevant for both electronic and ionic...

  17. Oxygen accumulation on metal surfaces investigated by XPS, AES and LEIS, an issue for sputter depth profiling under UHV conditions

    Energy Technology Data Exchange (ETDEWEB)

    Steinberger, R., E-mail: roland.steinberger@jku.at [Center for Surface and Nanoanalytics, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz (Austria); Celedón, C.E., E-mail: carlos.celedon@usm.cl [Institut für Experimentalphysik, Abteilung für Atom- und Oberflächenphysik, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz (Austria); Departamento de Física, Universidad Técnica Federico Santa María, Valaparaíso, Casilla 110-V (Chile); Bruckner, B., E-mail: barbara.bruckner@jku.at [Institut für Experimentalphysik, Abteilung für Atom- und Oberflächenphysik, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz (Austria); Roth, D., E-mail: dietmar.roth@jku.at [Institut für Experimentalphysik, Abteilung für Atom- und Oberflächenphysik, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz (Austria); Duchoslav, J., E-mail: jiri.duchoslav@jku.at [Center for Surface and Nanoanalytics, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz (Austria); Arndt, M., E-mail: martin.arndt@voestalpine.com [voestalpine Stahl GmbH, voestalpine-Straße 3, 4031 Linz (Austria); Kürnsteiner, P., E-mail: p.kuernsteiner@mpie.de [Center for Surface and Nanoanalytics, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz (Austria); and others

    2017-07-31

    Highlights: • Investigation on the impact of residual gas prevailing in UHV chambers. • For some metals detrimental oxygen uptake could be observed within shortest time. • Totally different behavior was found: no changes, solely adsorption and oxidation. • The UHV residual gas may severely corrupt results obtained from depth profiling. • A well-considered data acquisition sequence is the key for reliable depth profiles. - Abstract: Depth profiling using surface sensitive analysis methods in combination with sputter ion etching is a common procedure for thorough material investigations, where clean surfaces free of any contamination are essential. Hence, surface analytic studies are mostly performed under ultra-high vacuum (UHV) conditions, but the cleanness of such UHV environments is usually overrated. Consequently, the current study highlights the in principle known impact of the residual gas on metal surfaces (Fe, Mg, Al, Cr and Zn) for various surface analytics methods, like X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and low-energy ion scattering (LEIS). The investigations with modern, state-of-the-art equipment showed different behaviors for the metal surfaces in UHV during acquisition: (i) no impact for Zn, even after long time, (ii) solely adsorption of oxygen for Fe, slight and slow changes for Cr and (iii) adsorption accompanied by oxide formation for Al and Mg. The efficiency of different counter measures was tested and the acquired knowledge was finally used for ZnMgAl coated steel to obtain accurate depth profiles, which exhibited before serious artifacts when data acquisition was performed in an inconsiderate way.

  18. Condition and biochemical profile of blue mussels (Mytilus edulis L.) cultured at different depths in a cold water coastal environment

    Science.gov (United States)

    Gallardi, Daria; Mills, Terry; Donnet, Sebastien; Parrish, Christopher C.; Murray, Harry M.

    2017-08-01

    The growth and health of cultured blue mussels (Mytilus edulis) are affected by environmental conditions. Typically, culture sites are situated in sheltered areas near shore (i.e., conflicts and environmental impact in coastal areas are concerns and interest in developing deep water (> 20 m depth) mussel culture has been growing. This study evaluated the effect of culture depth on blue mussels in a cold water coastal environment (Newfoundland, Canada). Culture depth was examined over two years from September 2012 to September 2014; mussels from three shallow water (5 m) and three deep water (15 m) sites were compared for growth and biochemical composition; culture depths were compared for temperature and chlorophyll a. Differences between the two years examined were noted, possibly due to harsh winter conditions in the second year of the experiment. In both years shallow and deep water mussels presented similar condition; in year 2 deep water mussels had a significantly better biochemical profile. Lipid and glycogen analyses showed seasonal variations, but no significant differences between shallow and deep water were noted. Fatty acid profiles showed a significantly higher content of omega-3 s (20:5ω3; EPA) and lower content of bacterial fatty acids in deep water sites in year 2. Everything considered, deep water appeared to provide a more favorable environment for mussel growth than shallow water under harsher weather conditions.

  19. How Confocal Is Confocal Raman Microspectroscopy on the Skin? Impact of Microscope Configuration and Sample Preparation on Penetration Depth Profiles.

    Science.gov (United States)

    Lunter, Dominique Jasmin

    2016-01-01

    The aim of the study was to elucidate the effect of sample preparation and microscope configuration on the results of confocal Raman microspectroscopic evaluation of the penetration of a pharmaceutical active into the skin (depth profiling). Pig ear skin and a hydrophilic formulation containing procaine HCl were used as a model system. The formulation was either left on the skin during the measurement, or was wiped off or washed off prior to the analysis. The microscope configuration was varied with respect to objectives and pinholes used. Sample preparation and microscope configuration had a tremendous effect on the results of depth profiling. Regarding sample preparation, the best results could be observed when the formulation was washed off the skin prior to the analysis. Concerning microscope configuration, the use of a 40 × 0.6 numerical aperture (NA) objective in combination with a 25-µm pinhole or a 100 × 1.25 NA objective in combination with a 50-µm pinhole was found to be advantageous. Complete removal of the sample from the skin before the analysis was found to be crucial. A thorough analysis of the suitability of the chosen microscope configuration should be performed before acquiring concentration depth profiles. © 2016 S. Karger AG, Basel.

  20. Depth profiling of residual activity of ^{237}U fragments as a range verification technique for ^{238}U primary ion beam

    Directory of Open Access Journals (Sweden)

    I. Strašík

    2012-07-01

    Full Text Available Experimental and simulation data concerning fragmentation of ^{238}U ion beam in aluminum, copper, and stainless-steel targets with the initial energy 500 and 950  MeV/u are collected in the paper. A range-verification technique based on depth profiling of residual activity is presented. The irradiated targets were constructed in the stacked-foil geometry and analyzed using gamma-ray spectroscopy. One of the purposes of these experiments was depth profiling of residual activity of induced nuclides and projectile fragments. Among the projectile fragments, special attention is paid to the ^{237}U isotope that has a range very close to the range of the primary ^{238}U ions. Therefore, the depth profiling of the ^{237}U isotope can be utilized for experimental verification of the ^{238}U primary-beam range, which is demonstrated and discussed in the paper. The experimental data are compared with computer simulations by FLUKA, SRIM, and ATIMA, as well as with complementary experiments.

  1. Depth profiling of residual activity of U237 fragments as a range verification technique for U238 primary ion beam

    Science.gov (United States)

    Strašík, I.; Chetvertkova, V.; Mustafin, E.; Pavlovič, M.; Belousov, A.

    2012-07-01

    Experimental and simulation data concerning fragmentation of U238 ion beam in aluminum, copper, and stainless-steel targets with the initial energy 500 and 950MeV/u are collected in the paper. A range-verification technique based on depth profiling of residual activity is presented. The irradiated targets were constructed in the stacked-foil geometry and analyzed using gamma-ray spectroscopy. One of the purposes of these experiments was depth profiling of residual activity of induced nuclides and projectile fragments. Among the projectile fragments, special attention is paid to the U237 isotope that has a range very close to the range of the primary U238 ions. Therefore, the depth profiling of the U237 isotope can be utilized for experimental verification of the U238 primary-beam range, which is demonstrated and discussed in the paper. The experimental data are compared with computer simulations by FLUKA, SRIM, and ATIMA, as well as with complementary experiments.

  2. Quantitative evaluation of sputtering induced surface roughness and its influence on AES depth profiles of polycrystalline Ni/Cu multilayer thin films

    Science.gov (United States)

    Yan, X. L.; Coetsee, E.; Wang, J. Y.; Swart, H. C.; Terblans, J. J.

    2017-07-01

    The polycrystalline Ni/Cu multilayer thin films consisting of 8 alternating layers of Ni and Cu were deposited on a SiO2 substrate by means of electron beam evaporation in a high vacuum. Concentration-depth profiles of the as-deposited multilayered Ni/Cu thin films were determined with Auger electron spectroscopy (AES) in combination with Ar+ ion sputtering, under various bombardment conditions with the samples been stationary as well as rotating in some cases. The Mixing-Roughness-Information depth (MRI) model used for the fittings of the concentration-depth profiles accounts for the interface broadening of the experimental depth profiling. The interface broadening incorporates the effects of atomic mixing, surface roughness and information depth of the Auger electrons. The roughness values extracted from the MRI model fitting of the depth profiling data agrees well with those measured by atomic force microscopy (AFM). The ion sputtering induced surface roughness during the depth profiling was accordingly quantitatively evaluated from the fitted MRI parameters with sample rotation and stationary conditions. The depth resolutions of the AES depth profiles were derived directly from the values determined by the fitting parameters in the MRI model.

  3. [Depth Profiles of Methane Oxidation Kinetics and the Related Methanotrophic Community in a Simulated Landfill Cover].

    Science.gov (United States)

    Xing, Zhi-lin; Zhao, Tian-tao; Gao, Yan-hui; He, Zhi; Yang, Xu; Peng, Xu-ya

    2015-11-01

    Simulated landfill cover with real time online monitoring system was developed using cover soils. Then the system started and the concentrations of bio-gas in various depths were continuously monitored, and it was found that the system ran continually and stably after 2-3 h when methane flux changed. After that, the relationship between regularity of methane oxidation and methane flux in landfill cover was analyzed. The results indicated that concentration of oxygen decreased with increasing methane flux when the depth was deeper than 20 cm, and no obvious correlation between oxygen concentration in landfill cover surface and methane flux, however, methane oxidation rate showed positive correlation with methane flux in various depths (range of R2 was 0.851-0.999). Kinetics of CH4 oxidation in landfill cover was fitted by CH4 -O2 dual-substrate model (range of R2 was 0.902-0.955), the half-saturation constant K(m) increasing with depth was 0.157-0.729 in dynamic condition. Finally, methanotrophs community structure in original cover soil sample and that in simulated landfill cover were investigated by high-throughout sequencing technology, and the statistics indicated that the abundance and species of methanotrophs in simulated landfill cover significantly increased compared with those in original cover soil sample, and type I methanotrophs including Methylobacter and Methylophilaceae and type II methanotrophs Methylocystis were dominant species.

  4. Depth of maximum of air-shower profiles at the Pierre Auger Observatory. II. Composition implications

    NARCIS (Netherlands)

    Aab, A.; Abreu, P.; Aglietta, M.; Ahn, E. J.; Al Samarai, I.; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muniz, J.; Batista, R. Alves; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Aramo, C.; Aranda, V. M.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Awal, N.; Badescu, A. M.; Barber, K. B.; Baeuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertania, M. E.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blaess, S.; Blanco, M.; Bleve, C.; Bluemer, H.; Bohacova, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Bridgeman, A.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Buitink, S.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Candusso, M.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Chavez, A. G.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Coleman, A.; Collica, L.; Coluccia, M. R.; Conceicao, R.; Contreras, F.; Cooper, M. J.; Cordier, A.; Coutu, S.; Covault, C. E.; Cronin, J.; Curutiu, A.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; de Jong, S. J.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Di Matteo, A.; Diaz, J. C.; Diaz Castro, M. L.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dorofeev, A.; Hasankiadeh, Q. Dorosti; Dova, M. T.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Luis, P. Facal San; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fernandes, M.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipcic, A.; Fox, B. D.; Fratu, O.; Froehlich, U.; Fuchs, B.; Fuji, T.; Gaior, R.; Garcia, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Gascon Bravo, A.; Gate, F.; Gemmeke, H.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Glaser, C.; Glass, H.; Gomez Berisso, M.; Gomez Vitale, P. F.; Goncalves, P.; Gonzalez, J. G.; Gonzalez, N.; Gookin, B.; Gordon, J.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grebe, S.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guarino, F.; Guedes, G. P.; Hampel, M. R.; Hansen, P.; Harari, D.; Harrison, T. A.; Hartmann, S.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holt, E.; Homola, P.; Hoerandel, J. R.; Horvath, P.; Hrabovsky, M.; Huber, D.; Huege, T.; Insolia, A.; Isar, P. G.; Jandt, I.; Jansen, S.; Jarne, C.; Josebachuili, M.; Kaeaepae, A.; Kambeitz, O.; Kampert, K. H.; Kasper, P.; Katkov, I.; Kegl, B.; Keilhauer, B.; Keivani, A.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Kroemer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kunka, N.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Le Coz, S.; Leao, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; Lopez, R.; Lopez Agueera, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Malacari, M.; Maldera, S.; Mallamaci, M.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Maris, I. C.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martinez Bravo, O.; Martraire, D.; Masias Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Meissner, R.; Melissas, M.; Melo, D.; Menshikov, A.; Messina, S.; Meyhandan, R.; Micanovic, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Ragaigne, D. Monnier; Montanet, F.; Morello, C.; Mostafa, M.; Moura, C. A.; Muller, M. A.; Mueller, G.; Mueller, S.; Muenchmeyer, M.; Mussa, R.; Navarra, G.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nguyen, P.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nozka, L.; Ochilo, L.; Olinto, A.; Oliveira, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Papenbreer, P.; Parente, G.; Parra, A.; Paul, T.; Pech, M.; Pekala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Petermann, E.; Peters, C.; Petrera, S.; Petrov, Y.; Phuntsok, J.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porcelli, A.; Porowski, C.; Prado, R. R.; Privitera, P.; Prouza, M.; Purrello, V.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rizi, V.; Rodrigues de Carvalho, W.; Rodriguez Cabo, I.; Rodriguez Fernandez, G.; Rodriguez Rojo, J.; Rodriguez-Frias, M. D.; Rogozin, D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Roulet, E.; Rovero, A. C.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Saleh, A.; Greus, F. Salesa; Salina, G.; Sanchez, F.; Sanchez-Lucas, P.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarmento, R.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, D.; Scholten, O.; Schoorlemmer, H.; Schovanek, P.; Schulz, A.; Schulz, J.; Schumacher, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Sima, O.; Smialkowski, A.; Smida, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Squartini, R.; Srivastava, Y. N.; Stanic, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Stutz, A.; Suarez, F.; Suomijaervi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Taborda, O. A.; Tapia, A.; Tartare, M.; Tepe, A.; Theodoro, V. M.; Timmermans, C.; Todero Peixoto, C. J.; Toma, G.; Tomankova, L.; Tome, B.; Tonachini, A.; Torralba Elipe, G.; Torres Machado, D.; Travnicek, P.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdes Galicia, J. F.; Valino, I.; Valore, L.; van Aar, G.; van Bodegom, P.; van den Berg, A. M.; van Velzen, S.; van Vliet, A.; Varela, E.; Vargas Cardenas, B.; Varner, G.; Vazquez, J. R.; Vazquez, R. A.; Veberic, D.; Verzi, V.; Vicha, J.; Videla, M.; Villasenor, L.; Vlcek, B.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Widom, A.; Wiencke, L.; Wilczynska, B.; Wilczynski, H.; Will, M.; Williams, C.; Winchen, T.; Wittkowski, D.; Wundheiler, B.; Wykes, S.; Yamamoto, T.; Yapici, T.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Zhou, J.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.; Zuccarello, F.

    2014-01-01

    Using the data taken at the Pierre Auger Observatory between December 2004 and December 2012, we have examined the implications of the distributions of depths of atmospheric shower maximum (X-max), using a hybrid technique, for composition and hadronic interaction models. We do this by fitting the

  5. Depth profile of persistent and emerging organic pollutants upstream of the Three Gorges Dam gathered in 2012/2013.

    Science.gov (United States)

    Deyerling, Dominik; Wang, Jingxian; Bi, Yonghong; Peng, Chengrong; Pfister, Gerd; Henkelmann, Bernhard; Schramm, Karl-Werner

    2016-03-01

    Persistent and emerging organic pollutants were sampled in September 2012 and 2013 at a sampling site in front of the Three Gorges Dam near Maoping (China) in a water depth between 11 and 61 m to generate a depth profile of analytes. A novel compact water sampling system with self-packed glass cartridges was employed for the on-site enrichment of approximately 300 L of water per sample to enable the detection of low analytes levels in the picogram per liter-scale in the large water body. The overall performance of the sampling system was acceptable for the qualitative detection of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), perfluoroalkylic acids (PFAAs), pharmaceutical residues and polar pesticides. Strongly particle-associated analytes like PAHs and PCBs resided mainly in the glass wool filter of the sampling system, whereas all other compounds have mainly been enriched on the XAD-resin of the self-packed glass cartridges. The sampling results revealed qualitative information on the presence, depth distribution and origin of the investigated compounds. Although the depth profile of PAHs, PCBs, OCPs, and PFAAs appeared to be homogeneous, pharmaceuticals and polar pesticides were detected in distinct different patterns with water depth. Source analysis with diagnostic ratios for PAHs revealed their origin to be pyrogenic (burning of coal, wood and grass). In contrast, most PCBs and OCPs had to be regarded as legacy pollutants which have been released into the environment in former times and still remain present due to their persistence. The abundance of emerging organic pollutants could be confirmed, and their most abundant compounds could be identified as perfluorooctanoic acid, diclofenac and atrazine among investigated PFAAs, pharmaceuticals and polar pesticides, respectively.

  6. De-coding the Neutral Hydrogen (21cm) Line Profiles of Disk galaxies

    Science.gov (United States)

    Moak, Sandy; Madore, Barry; Khatami, David

    2017-01-01

    Neutral hydrogen is the most abundant element in the interstellar medium, and it has long lent astronomers insight into galaxy structure, galactic interactions, and even dark matter prevalence. It is necessary to implement a detailed coding scheme that characterizes the 21-cm HI line profiles which exist in abundance throughout literature. We have utilized a new computer simulation program that exposes the internal architecture of a galaxy by way of mapping the one-dimensional line profile on to the three-dimensional parameters of a given galaxy. We have created a naming system to classify HI line profiles, which represents a kinematic description of the galaxy simply by considering its classification within the coding scheme.

  7. Fiber optic picosecond laser pulse transmission line for hydrogen ion beam longitudinal profile measurement.

    Science.gov (United States)

    Huang, Chunning; Liu, Yun; Aleksandrov, Alexander

    2013-07-01

    We present a fiber optic laser pulse transmission line for nonintrusive longitudinal profile measurement of the hydrogen ion (H(-)) beam at the front-end of the Spallation Neutron Source accelerator. The 80.5 MHz, 2.5 ps, multikilowatt optical pulses are delivered to the accelerator beam line through a large-mode-area polarization-maintaining optical fiber to ensure high measurement stability. The transmission efficiency, output laser beam quality, pulse jitter, and pulse width broadening over a 30 m long fiber line are experimentally investigated. A successful measurement of the H(-) beam microbunch (~130 ps) profile is obtained. The experiment is the first demonstration to our knowledge of particle beam profile diagnostics using a fiber optic laser pulse transmission line.

  8. Improvement of Depth Profiling into Biotissues Using Micro Electrical Impedance Spectroscopy on a Needle with Selective Passivation

    Directory of Open Access Journals (Sweden)

    Joho Yun

    2016-12-01

    Full Text Available A micro electrical impedance spectroscopy (EIS-on-a-needle for depth profiling (μEoN-DP with a selective passivation layer (SPL on a hypodermic needle was recently fabricated to measure the electrical impedance of biotissues along with the penetration depths. The SPL of the μEoN-DP enabled the sensing interdigitated electrodes (IDEs to contribute predominantly to the measurement by reducing the relative influence of the connection lines on the sensor output. The discrimination capability of the μEoN-DP was verified using phosphate-buffered saline (PBS at various concentration levels. The resistance and capacitance extracted through curve fitting were similar to those theoretically estimated based on the mixing ratio of PBS and deionized water; the maximum discrepancies were 8.02% and 1.85%, respectively. Depth profiling was conducted using four-layered porcine tissue to verify the effectiveness of the discrimination capability of the μEoN-DP. The magnitude and phase between dissimilar porcine tissues (fat and muscle were clearly discriminated at the optimal frequency of 1 MHz. Two kinds of simulations, one with SPL and the other with complete passivation layer (CPL, were performed, and it was verified that the SPL was advantageous over CPL in the discrimination of biotissues in terms of sensor output.

  9. Quantitative damage depth profiles in arsenic implanted HgCdTe

    Energy Technology Data Exchange (ETDEWEB)

    Lobre, C., E-mail: clement.lobre@cea.fr [CEA-Leti, MINATEC, 17 rue des Martyrs, 38054 Grenoble cedex 9 (France); Jalabert, D. [CEA-INAC/UJF-Grenoble 1 UMR-E, MINATEC, 17 rue des Martyrs, 38054 Grenoble cedex 9 (France); Vickridge, I.; Briand, E.; Benzeggouta, D. [Institut des NanoSciences de Paris, UMR 7588 du CNRS, Universite de Pierre et Marie Curie, Paris (France); Mollard, L. [CEA-Leti, MINATEC, 17 rue des Martyrs, 38054 Grenoble cedex 9 (France); Jouneau, P.H. [CEA-INAC/UJF-Grenoble 1 UMR-E, MINATEC, 17 rue des Martyrs, 38054 Grenoble cedex 9 (France); Ballet, P. [CEA-Leti, MINATEC, 17 rue des Martyrs, 38054 Grenoble cedex 9 (France)

    2013-10-15

    Rutherford backscattering experiments under channeling conditions (RBS-c) have been carried out on Hg{sub 0.77}Cd{sub 0.23}Te (MCT) layers implanted with arsenic. Accurate damage profiles have been extracted through a simple formalism for implanted and annealed layers. Quantitative damage profiles are correlated with structural defects observed by bright-field scanning transmission electron microscopy (BF-STEM) and chemical composition measured by secondary ion mass spectrometry (SIMS). Evolution of damage for increasing ion implantation fluence has been investigated by these three complementary techniques. Evidence is found of irradiation induced annealing during implantation. A fast damage recovery has been observed for post-implantation thermal anneals. In the case of an implanted layer annealed during 1 h, the damage profile, associated with arsenic concentration measurements, indicates the presence of complexes involving arsenic.

  10. Electrochemical depth profiling of multilayer metallic structures: An aluminum brazing sheet

    DEFF Research Database (Denmark)

    Afshar, F. Norouzi; Ambat, R.; Kwakernaak, C.

    2012-01-01

    potential, cathodic and anodic reactivities, and tracking their changes as a function of depth, the evolution of electrochemical responses through out the material thickness were analyzed and correlated to the corresponding microstructural features. Polarization curves in 1wt% NaCl solution at pH 2.8 were...... obtained at different depths from the surface using controlled sputtering in a glow discharge optical emission spectrometer as a sample preparation technique. The anodic and cathodic reactivity of the top surface areas were significantly higher than that of the bulk, thus indicating these areas to be more...... susceptible to localized attack. Consistent with this, optical microscopy and scanning electron microscope analysis revealed a relatively high density of fine intermetallic and silicon particles at these areas. The corrosion mechanism of the top layers was identified to be intergranular and pitting corrosion...

  11. A search for thermal excursions from ancient extraterrestrial impacts using Hadean zircon Ti-U-Th-Pb depth profiles.

    Science.gov (United States)

    Abbott, Sunshine S; Harrison, T Mark; Schmitt, Axel K; Mojzsis, Stephen J

    2012-08-21

    Few terrestrial localities preserve more than a trace lithic record prior to ca. 3.8 Ga greatly limiting our understanding of the first 700 Ma of Earth history, a period inferred to have included a spike in the bolide flux to the inner solar system at ca. 3.85-3.95 Ga (the Late Heavy Bombardment, LHB). An accessible record of this era may be found in Hadean detrital zircons from the Jack Hills, Western Australia, in the form of μm-scale epitaxial overgrowths. By comparing crystallization temperatures of pre-3.8 Ga zircon overgrowths to the archive of zircon temperature spectra, it should, in principle, be possible to identify a distinctive impact signature. We have developed Ti-U-Th-Pb ion microprobe depth profiling to obtain age and temperature information within these zircon overgrowths and undertaken a feasibility study of its possible use in identifying impact events. Of eight grains profiled in this fashion, four have overgrowths of LHB-era age. Age vs. temperature profiles reveal a period between ca. 3.85-3.95 Ga (i.e., LHB era) characterized by significantly higher temperatures (approximately 840-875 °C) than do older or younger zircons or zircon domains (approximately 630-750 °C). However, temperatures approaching 900 °C can result in Pb isotopic exchange rendering interpretation of these profiles nonunique. Coupled age-temperature depth profiling shows promise in this role, and the preliminary data we report could represent the first terrestrial evidence for impact-related heating during the LHB.

  12. Modelling the evolution of composition-and stress-depth profiles in austenitic stainless steels during low-temperature nitriding

    DEFF Research Database (Denmark)

    Jespersen, Freja Nygaard; Hattel, Jesper Henri; Somers, Marcel A. J.

    2016-01-01

    . In the present paper solid mechanics was combined with thermodynamics and diffusion kinetics to simulate the evolution of composition-depth and stress-depth profiles resulting from nitriding. The model takes into account a composition-dependent diffusion coefficient of nitrogen in expanded austenite, short range...... that accompanies the dissolution of high nitrogen contents in expanded austenite. An intriguing phenomenon during low-temperature nitriding is that the residual stresses evoked by dissolution of nitrogen in the solid state, affect the thermodynamics and the diffusion kinetics of nitrogen dissolution...... ordering (trapping) of nitrogen atoms by chromium atoms, and the effect of composition-induced stress on surface concentration and diffusive flux. The effect of plasticity and concentration-dependence of the yield stress was also included....

  13. Depth Profiling of La2O3 ∕ HfO2 Stacked Dielectrics for Nanoelectronic Device Applications

    KAUST Repository

    Alshareef, Husam N.

    2011-01-03

    Nanoscale La2O3 /HfO2 dielectric stacks have been studied using high resolution Rutherford backscattering spectrometry. The measured distance of the tail-end of the La signal from the dielectric/Si interface suggests that the origin of the threshold voltage shifts and the carrier mobility degradation may not be the same. Up to 20% drop in mobility and 500 mV shift in threshold voltage was observed as the La signal reached the Si substrate. Possible reasons for these changes are proposed, aided by depth profiling and bonding analysis. © 2011 The Electrochemical Society.

  14. A summary report on the search for current technologies and developers to develop depth profiling/physical parameter end effectors

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Q.H.

    1994-09-12

    This report documents the search strategies and results for available technologies and developers to develop tank waste depth profiling/physical parameter sensors. Sources searched include worldwide research reports, technical papers, journals, private industries, and work at Westinghouse Hanford Company (WHC) at Richland site. Tank waste physical parameters of interest are: abrasiveness, compressive strength, corrosiveness, density, pH, particle size/shape, porosity, radiation, settling velocity, shear strength, shear wave velocity, tensile strength, temperature, viscosity, and viscoelasticity. A list of related articles or sources for each physical parameters is provided.

  15. Effect of Hydrogenated, Liquid and Ghee Oils on Serum Lipids Profile

    OpenAIRE

    Mohammadifard, Noushin; Nazem, Masoud; Naderi, Gholam-Ali; Saghafian, Faezeh; Sajjadi, Firoozeh; Maghroon, Maryam; Bahonar, Ahmad; Alikhasi, Hasan; Nouri, Fatemeh

    2010-01-01

    BACKGROUND Trans fatty acids are known as the most harmful type of dietary fats, so this study was done to compare the effects of hydrogenated, liquid and ghee oils on serum lipids profile of healthy adults. METHODS This study was a randomized clinical trial conducted on 129 healthy participants aged from 20 to 60 years old who were beneficiaries of Imam-e-Zaman charitable organization. Subjects were randomly divided into 3 groups and each group was treated with a diet containing cooking and ...

  16. Assessment of Zooplankton Community Composition along a Depth Profile in the Central Red Sea

    KAUST Repository

    Pearman, John K.

    2015-07-17

    The composition of zooplankton in the water column has received limited attention in the main body of the Red Sea and this study investigates the change in the community both spatially and temporally across 11 stations in the central Red Sea. Using molecular methods to target the v9 region of the 18S rRNA gene a total of approximately 11.5 million reads were sequenced resulting in 2528 operational taxonomic units (OTUs) at 97% similarity. The phylum Arthropoda dominated in terms of reads accounting for on average 86.2% and 65.3% for neuston nets and vertical multinets respectively. A reduction in the number of OTUs was noticed with depth for both total metazoa and Maxillopoda whilst there was also a significant change in the composition of the Maxillopoda community. The genus Corycaeus had a higher proportion of reads in the epipelagic zone with Pleuromamma becoming increasingly dominant with depth. No significant difference was observed in the community between night and day sampling however there was a significant difference in the zooplankton community between two sampling periods separated by 10 days.

  17. XPS depth profiling of derivatized amine and anhydride plasma polymers: Evidence of limitations of the derivatization approach

    Energy Technology Data Exchange (ETDEWEB)

    Manakhov, Anton, E-mail: ant-manahov@ya.ru [National University of Science and Technology “MISiS”, Leninsky pr. 4, Moscow 119049 (Russian Federation); RG Plasma Technologies, CEITEC – Masaryk University, Purkyňova 123, Brno 61200 (Czech Republic); Michlíček, Miroslav [RG Plasma Technologies, CEITEC – Masaryk University, Purkyňova 123, Brno 61200 (Czech Republic); Department of Physical Electronics, Faculty of Science, Masaryk University, Kotlářská, 2, Brno 61137 (Czech Republic); Felten, Alexandre; Pireaux, Jean-Jacques [LISE, Department of Physics, University of Namur, Rue de Bruxelles, 61, Namur B5000 (Belgium); Nečas, David [RG Plasma Technologies, CEITEC – Masaryk University, Purkyňova 123, Brno 61200 (Czech Republic); Zajíčková, Lenka [RG Plasma Technologies, CEITEC – Masaryk University, Purkyňova 123, Brno 61200 (Czech Republic); Department of Physical Electronics, Faculty of Science, Masaryk University, Kotlářská, 2, Brno 61137 (Czech Republic)

    2017-02-01

    Highlights: • TFBA derivatizatized amine plasma layers exhibited heterogeneous profile of [F] due to low diffusion (permeability) of TFBA • Anhydride layers derivatized by trifluoroethylamine exhibited relatively homogenous profile as this molecule is smaller • The results of TFBA derivatization will depend on XPS take-off angle, polymer crosslinking and density - Abstract: The quantitative analysis of the chemistry at the surface of functional plasma polymers is highly important for the optimization of their deposition conditions and, therefore, for their subsequent applications. The chemical derivatization of amine and carboxyl-anhydride layers is a well-known technique already applied by many researchers, notwithstanding the known drawback of the derivatization procedures like side or uncomplete reactions that could lead to “unreliable” results. In this work, X-ray photoelectron spectroscopy (XPS) combined with depth profiling with argon clusters is applied for the first time to study derivatized amine and carboxyl-anhydride plasma polymer layers. It revealed an additional important parameter affecting the derivatization reliability, namely the permeation of the derivatizing molecule through the target analysed layer, i.e. the composite effect of the probe molecule size and the layer porosity. Amine-rich films prepared by RF low pressure plasma polymerization of cyclopropylamine were derivatized with trifluoromethyl benzaldehide (TFBA) and it was observed by that the XPS-determined NH{sub 2} concentration depth profile is rapidly decreasing over top ten nanometers of the layer. The anhydride-rich films prepared by atmospheric plasma co-polymerization of maleic anhydride and C{sub 2}H{sub 2} have been reacted with, parafluoroaniline and trifluoroethyl amine. The decrease of the F signal in top surface layer of the anhydride films derivatized by the “large” parafluoroaniline was observed similarly as for the amine films but the derivatization with

  18. The national psychological/personality profile of Romanians: An in depth analysis of the regional national psychological/personality profile of Romanians

    Directory of Open Access Journals (Sweden)

    David, D.

    2015-12-01

    Full Text Available In this article we perform an in depth analysis of the national psychological/personality profile of Romanians. Following recent developments in the field (see Rentfrow et al., 2013; 2015, we study the regional national psychological/personality profile of Romanians, based on the Big Five model (i.e., NEO PI/R. Using a representative sample (N1 = 1000, we performed a cluster analysis and identified two bipolar personality profiles in the population: cluster 1, called “Factor X-”, characterized by high neuroticism and low levels of extraversion, openness, agreeableness, and conscientiousness, and cluster 2, called “Factor X+”, characterized by the opposite configuration in personality traits, low neuroticism and high levels of extraversion, openness, agreeableness, and conscientiousness. The same two cluster pattern/solution emerged in other samples (N = 2200, with other Big Five-based instruments, and by using various methods of data (e.g., direct vs. reversed item score, controlling for item desirability and cluster (i.e., with and without “running means” analyses. These two profiles are quite evenly distributed in the overall population, but also across all geographical regions. Moreover, comparing the distribution of the five personality traits, we found just few small differences between the eight geographical divisions that we used for our analysis. These results suggest that the regional national psychological/personality profile of Romania is quite homogenous. Directions for harnessing the potential of both personality profiles are presented to the reader. Other implications based on the bipolar and fractal structure of the personality profile are discussed from an interdisciplinary perspective.

  19. Comparison of stratum corneum thickness between two proposed methods of calculation using Raman spectroscopic depth profiling of skin water content.

    Science.gov (United States)

    Lee, M; Won, K; Kim, E J; Hwang, J S; Lee, H K

    2018-02-20

    The stratum corneum (SC) is the most important layer for the barrier function of skin, so investigation of the SC is very important in cosmetic and medical research. Here, we calculated the SC thickness using the depth profile of the skin's water concentration based on previously described methods, and then compared the results. Seven Korean women in their 30s participated in this study. Raman spectroscopy was used to measure the in vivo depth profile of skin water concentration. A total of 21 areas were measured at forearm. Microsoft Excel 2007 was used to calculate SC thickness based on the slope and intersection methods. The slope method and the intersection method gave a forearm SC thickness calculated at 21.3 ± 2.6 μm and 17.6 ± 2.8 μm, respectively. There was a significant difference between the two calculation methods but the two methods showed strong correlation of SC thickness results (r = .899). Although there was a difference in calculated SC thickness of about 20% between the two methods, these results reveal that the two SC thickness calculation methods using Raman spectroscopy were suitable for measuring SC thickness, a finding consistent with other published results. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Oxygen accumulation on metal surfaces investigated by XPS, AES and LEIS, an issue for sputter depth profiling under UHV conditions

    Science.gov (United States)

    Steinberger, R.; Celedón, C. E.; Bruckner, B.; Roth, D.; Duchoslav, J.; Arndt, M.; Kürnsteiner, P.; Steck, T.; Faderl, J.; Riener, C. K.; Angeli, G.; Bauer, P.; Stifter, D.

    2017-07-01

    Depth profiling using surface sensitive analysis methods in combination with sputter ion etching is a common procedure for thorough material investigations, where clean surfaces free of any contamination are essential. Hence, surface analytic studies are mostly performed under ultra-high vacuum (UHV) conditions, but the cleanness of such UHV environments is usually overrated. Consequently, the current study highlights the in principle known impact of the residual gas on metal surfaces (Fe, Mg, Al, Cr and Zn) for various surface analytics methods, like X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and low-energy ion scattering (LEIS). The investigations with modern, state-of-the-art equipment showed different behaviors for the metal surfaces in UHV during acquisition: (i) no impact for Zn, even after long time, (ii) solely adsorption of oxygen for Fe, slight and slow changes for Cr and (iii) adsorption accompanied by oxide formation for Al and Mg. The efficiency of different counter measures was tested and the acquired knowledge was finally used for ZnMgAl coated steel to obtain accurate depth profiles, which exhibited before serious artifacts when data acquisition was performed in an inconsiderate way.

  1. Improved quantitative analysis of Cu(In,Ga)Se{sub 2} thin films using MCs{sup +}-SIMS depth profiling

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jihye; Kim, Seon Hee; Lee, Kang-Bong; Lee, Yeonhee [Korea Institute of Science and Technology, Advanced Analysis Center, Seoul (Korea, Republic of); Min, Byoung Koun [Korea Institute of Science and Technology, Clean Energy Research Center, Seoul (Korea, Republic of)

    2014-06-15

    The chalcopyrite semiconductor, Cu(InGa)Se{sub 2} (CIGS), is popular as an absorber material for incorporation in high-efficiency photovoltaic devices because it has an appropriate band gap and a high absorption coefficient. To improve the efficiency of solar cells, many research groups have studied the quantitative characterization of the CIGS absorber layers. In this study, a compositional analysis of a CIGS thin film was performed by depth profiling in secondary ion mass spectrometry (SIMS) with MCs{sup +} (where M denotes an element from the CIGS sample) cluster ion detection, and the relative sensitivity factor of the cluster ion was calculated. The emission of MCs{sup +} ions from CIGS absorber elements, such as Cu, In, Ga, and Se, under Cs{sup +} ion bombardment was investigated using time-of-flight SIMS (TOF-SIMS) and magnetic sector SIMS. The detection of MCs{sup +} ions suppressed the matrix effects of varying concentrations of constituent elements of the CIGS thin films. The atomic concentrations of the CIGS absorber layers from the MCs{sup +}-SIMS exhibited more accurate quantification compared to those of elemental SIMS and agreed with those of inductively coupled plasma atomic emission spectrometry. Both TOF-SIMS and magnetic sector SIMS depth profiles showed a similar MCs{sup +} distribution for the CIGS thin films. (orig.)

  2. Hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Pier, M.

    1943-02-19

    A transcript is presented of a speech on the history of the development of hydrogenation of coal and tar. Apparently the talk had been accompanied by the showing of photographic slides, but none of the pictures were included with the report. In giving the history, Dr. Pier mentioned the dependence of much of the development of hydrogenation upon previous development in the related areas of ammonia and methanol syntheses, but he also pointed out several ways in which equipment appropriate for hydrogenation differed considerably from that used for ammonia and methanol. Dr. Pier discussed the difficulties encountered with residue processing, design of the reaction ovens, manufacture of ovens and preheaters, heating of reaction mixtures, development of steels, and development of compressor pumps. He described in some detail his own involvement in the development of the process. In addition, he discussed the development of methods of testing gasolines and other fuels. Also he listed some important byproducts of hydrogenation, such as phenols and polycyclic aromatics, and he discussed the formation of iso-octane fuel from the butanes arising from hydrogenation. In connection with several kinds of equipment used in hydrogenation (whose pictures were being shown), Dr. Pier gave some of the design and operating data.

  3. Temperature profile and water depth data collected from HARKNESS in the Indian Ocean from 15 December 1986 to 14 January 1987 (NODC Accession 8700087)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the HARKNESS in the Indian Ocean and TOGA Area - India Ocean. Data were collected...

  4. Temperature profile and water depth data collected from R/V ENDEAVOR using CTD casts from 14 September 1981 to 01 October 1981 (NODC Accession 8600220)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using CTD casts from the R/V ENDEAVOR. Data were collected from 14 September 1981 to 01 October 1981 by Woods...

  5. National Coral Reef Monitoring Program: Shallow Water Conductivity-Temperature-Depth (CTD) Profiles for selected locations across the Hawaiian Archipelago in 2013 (NCEI Accession 0161327)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Near-shore shallow water Conductivity-Temperature-Depth (CTD) surveys provided vertical profiles of temperature, salinity, and turbidity providing indications for...

  6. Temperature profile and water depth data collected from USS MOBILE BAY in the NW Atlantic Ocean from 05 March 1987 to 31 March 1987 (NODC Accession 8700170)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS MOBILE BAY in the Northwest Atlantic Ocean and Caribbean Sea. Data were...

  7. Temperature profile and water depth data collected from DOWNES in the NW Pacific (limit-180W) from 09 September 1986 to 29 September 1986 (NODC Accession 8700044)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT from the DOWNES in the Northeast Pacific Ocean. Data were collected from 09 September 1986...

  8. National Coral Reef Monitoring Program: Shallow Water Conductivity-Temperature-Depth (CTD) Profiles for selected locations across the Pacific Remote Island Areas since 2014

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Near-shore shallow water Conductivity-Temperature-Depth (CTD) surveys provided vertical profiles of temperature, salinity, and turbidity providing indications for...

  9. National Coral Reef Monitoring Program: Shallow Water Conductivity-Temperature-Depth (CTD) Profiles for selected locations across American Samoa in 2015

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Near-shore shallow water Conductivity-Temperature-Depth (CTD) surveys provided vertical profiles of temperature, salinity, and turbidity providing indications for...

  10. National Coral Reef Monitoring Program: Shallow Water Conductivity-Temperature-Depth (CTD) Profiles for selected locations across the Mariana Archipelago in 2014

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Near-shore shallow water Conductivity-Temperature-Depth (CTD) surveys provided vertical profiles of temperature, salinity, and turbidity providing indications for...

  11. National Coral Reef Monitoring Program: Shallow Water Conductivity-Temperature-Depth (CTD) Profiles for selected locations across the Hawaiian Archipelago since 2013

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Near-shore shallow water Conductivity-Temperature-Depth (CTD) surveys provided vertical profiles of temperature, salinity, and turbidity providing indications for...

  12. Temperature profile and water depth data collected from HARKNESS in the Indian Ocean from 01 March 1987 to 10 March 1987 (NODC Accession 8700159)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT from the HARKNESS in the Indian Ocean and TOGA Area - Indian Ocean. Data were collected from...

  13. Temperature profile and water depth data collected from COCHRANE in the South China Sea and other seas from 09 January 1987 to 22 February 1987 (NODC Accession 8700095)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT from the COCHRANE in the South China and other seas. Data were collected from 09 January...

  14. Argon Cluster Sputtering Source for ToF-SIMS Depth Profiling of Insulating Materials: High Sputter Rate and Accurate Interfacial Information

    National Research Council Canada - National Science Library

    Wang, Zhaoying; Liu, Bingwen; Zhao, Evan W; Jin, Ke; Du, Yingge; Neeway, James J; Ryan, Joseph V; Hu, Dehong; Zhang, Kelvin H. L; Hong, Mina; Le Guernic, Solenne; Thevuthasan, Suntharampilai; Wang, Fuyi; Zhu, Zihua

    2015-01-01

    The use of an argon cluster ion sputtering source has been demonstrated to perform superiorly relative to traditional oxygen and cesium ion sputtering sources for ToF-SIMS depth profiling of insulating materials...

  15. Depth profiling of inks in authentic and counterfeit banknotes by electrospray laser desorption ionization/mass spectrometry.

    Science.gov (United States)

    Kao, Yi-Ying; Cheng, Sy-Chyi; Cheng, Chu-Nian; Shiea, Jentaie

    2016-01-01

    Electrospray laser desorption ionization is an ambient ionization technique that generates neutrals via laser desorption and ionizes those neutrals in an electrospray plume and was utilized to characterize inks in different layers of copy paper and banknotes of various currencies. Depth profiling of inks was performed on overlapping color bands on copy paper by repeatedly scanning the line with a pulsed laser beam operated at a fixed energy. The molecules in the ink on a banknote were desorbed by irradiating the banknote surface with a laser beam operated at different energies, with results indicating that different ions were detected at different depths. The analysis of authentic $US100, $100 RMB and $1000 NTD banknotes indicated that ions detected in 'color-shifting' and 'typography' regions were significantly different. Additionally, the abundances of some ions dramatically changed with the depth of the aforementioned regions. This approach was used to distinguish authentic $1000 NTD banknotes from counterfeits. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  16. Carbon dynamics in the western Arctic Ocean: insights from full-depth carbon isotope profiles of DIC, DOC, and POC

    Directory of Open Access Journals (Sweden)

    D. R. Griffith

    2012-03-01

    Full Text Available Arctic warming is projected to continue throughout the coming century. Yet, our currently limited understanding of the Arctic Ocean carbon cycle hinders our ability to predict how changing conditions will affect local Arctic ecosystems, regional carbon budgets, and global climate. We present here the first set of concurrent, full-depth, dual-isotope profiles for dissolved inorganic carbon (DIC, dissolved organic carbon (DOC, and suspended particulate organic carbon (POCsusp at two sites in the Canada Basin of the Arctic Ocean. The carbon isotope composition of sinking and suspended POC in the Arctic contrasts strongly with open ocean Atlantic and Pacific sites, pointing to a combination of inputs to Arctic POCsusp at depth, including surface-derived organic carbon (OC, sorbed/advected OC, and OC derived from in situ DIC fixation. The latter process appears to be particularly important at intermediate depths, where mass balance calculations suggest that OC derived from in situ DIC fixation contributes up to 22% of POCsusp. As in other oceans, surface-derived OC is still a dominant source to Arctic POCsusp. Yet, we suggest that significantly smaller vertical POC fluxes in the Canada Basin make it possible to see evidence of DIC fixation in the POCsusp pool even at the bulk isotope level.

  17. Does strip-tillage could limit the drop of yields on soils of reduced depth of profiles in loess areas?

    Science.gov (United States)

    Rejman, Jerzy; Rafalska-Przysucha, Anna; Jadzczyszyn, Jan; Rodzik, Jan

    2016-04-01

    Strip tillage restrict a tillage operation to seed rows and enables a combination of tillage, sowing and application of fertilizers during one pass of agricultural machines. The practice decreases the costs of fuel and limits the risk of water erosion by the increase of infiltration of soil water. In the studies, we put a hypothesis that strip tillage is a tool to increase the yields on soils of reduced profiles. Studies were carried out in the loess area of the Lublin Upland (Poland). The site is cultivated from the beginning of the 18th century, and strip tillage is performed from 2008. All plant residues is left after harvest in the field and mixed with the soil by disc harrow. Measurements of solum depth (Ap-BC), soil properties and parameters of plant growth were carried out in 108 points in the field of the area of 4 ha. Crops included winter wheat (2014) and maize (2015). Studies showed that the profiles of Haplic Luvisol were largely truncated or overbuilt due to erosion and moldboard plow in the past. Solum depth ranged from 0.2 to 3.6 m (mean=1.29 m, CV=64%), and soils with the non-eroded, slightly, moderately, severely, very severely eroded and depositional profiles represented 13, 32, 10, 5, 8 and 32% of total number of cores, respectively. In a result of modification of profiles, clay content ranged from 84 to 222 (145; 16%) in the layer of 0-15 cm, whereas SOC concentration remained on relatively low level and ranged from 4.3 to 16.8 g/kg (9.1; 21.4%). Soil water content (SWC) within depth of 1-m profile was differentiated at the start of measurements in the middle of June 2015. The SWC was the highest in non-eroded and depositional soils and the smallest in severely and very severely eroded soils. The difference of 5% has maintained during the whole growing season and did not affect the growth of plants till the phase of flowering. Then, the plants on shallower soils passed quicker to the next phenological phases in comparison to the plants on deeper

  18. Quantitative Analysis of Human Pluripotency and Neural Specification by In-Depth (PhosphoProteomic Profiling

    Directory of Open Access Journals (Sweden)

    Ilyas Singec

    2016-09-01

    Full Text Available Controlled differentiation of human embryonic stem cells (hESCs can be utilized for precise analysis of cell type identities during early development. We established a highly efficient neural induction strategy and an improved analytical platform, and determined proteomic and phosphoproteomic profiles of hESCs and their specified multipotent neural stem cell derivatives (hNSCs. This quantitative dataset (nearly 13,000 proteins and 60,000 phosphorylation sites provides unique molecular insights into pluripotency and neural lineage entry. Systems-level comparative analysis of proteins (e.g., transcription factors, epigenetic regulators, kinase families, phosphorylation sites, and numerous biological pathways allowed the identification of distinct signatures in pluripotent and multipotent cells. Furthermore, as predicted by the dataset, we functionally validated an autocrine/paracrine mechanism by demonstrating that the secreted protein midkine is a regulator of neural specification. This resource is freely available to the scientific community, including a searchable website, PluriProt.

  19. SIMS depth profiling of SiGe:C structures in test pattern areas using low energy cesium with a Cameca IMS Wf

    Energy Technology Data Exchange (ETDEWEB)

    Juhel, M.; Laugier, F

    2004-06-15

    In this paper, we describe our utilization of SIMS to support development of new SiGe:C structures for BiCMOS industrial processes. The goal is to perform quantitative germanium and carbon depth profiles in test areas of 300 {mu}mx300 {mu}m with optimum depth resolution and detection limits.

  20. Depth of maximum of air-shower profiles at the Pierre Auger Observatory. II. Composition implications

    Science.gov (United States)

    Aab, A.; Abreu, P.; Aglietta, M.; Ahn, E. J.; Al Samarai, I.; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Aramo, C.; Aranda, V. M.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Awal, N.; Badescu, A. M.; Barber, K. B.; Bäuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertania, M. E.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blaess, S.; Blanco, M.; Bleve, C.; Blümer, H.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Bridgeman, A.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Buitink, S.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Candusso, M.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Chavez, A. G.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Coleman, A.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cooper, M. J.; Cordier, A.; Coutu, S.; Covault, C. E.; Cronin, J.; Curutiu, A.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; de Jong, S. J.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Di Matteo, A.; Diaz, J. C.; Díaz Castro, M. L.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dorofeev, A.; Dorosti Hasankiadeh, Q.; Dova, M. T.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fernandes, M.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipčič, A.; Fox, B. D.; Fratu, O.; Fröhlich, U.; Fuchs, B.; Fuji, T.; Gaior, R.; García, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Gascon Bravo, A.; Gate, F.; Gemmeke, H.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Glaser, C.; Glass, H.; Gómez Berisso, M.; Gómez Vitale, P. F.; Gonçalves, P.; Gonzalez, J. G.; González, N.; Gookin, B.; Gordon, J.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grebe, S.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guarino, F.; Guedes, G. P.; Hampel, M. R.; Hansen, P.; Harari, D.; Harrison, T. A.; Hartmann, S.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holt, E.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huber, D.; Huege, T.; Insolia, A.; Isar, P. G.; Jandt, I.; Jansen, S.; Jarne, C.; Josebachuili, M.; Kääpä, A.; Kambeitz, O.; Kampert, K. H.; Kasper, P.; Katkov, I.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Krömer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kunka, N.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Le Coz, S.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Lopez Agüera, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Malacari, M.; Maldera, S.; Mallamaci, M.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Mariş, I. C.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martínez Bravo, O.; Martraire, D.; Masías Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Meissner, R.; Melissas, M.; Melo, D.; Menshikov, A.; Messina, S.; Meyhandan, R.; Mićanović, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morello, C.; Mostafá, M.; Moura, C. A.; Muller, M. A.; Müller, G.; Müller, S.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nguyen, P.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nožka, L.; Ochilo, L.; Olinto, A.; Oliveira, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Papenbreer, P.; Parente, G.; Parra, A.; Paul, T.; Pech, M.; PÈ©kala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Petermann, E.; Peters, C.; Petrera, S.; Petrov, Y.; Phuntsok, J.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porcelli, A.; Porowski, C.; Prado, R. R.; Privitera, P.; Prouza, M.; Purrello, V.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rizi, V.; Rodrigues de Carvalho, W.; Rodriguez Cabo, I.; Rodriguez Fernandez, G.; Rodriguez Rojo, J.; Rodríguez-Frías, M. D.; Rogozin, D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Roulet, E.; Rovero, A. C.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Saleh, A.; Salesa Greus, F.; Salina, G.; Sánchez, F.; Sanchez-Lucas, P.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarmento, R.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, D.; Scholten, O.; Schoorlemmer, H.; Schovánek, P.; Schulz, A.; Schulz, J.; Schumacher, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Sima, O.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Squartini, R.; Srivastava, Y. N.; Stanič, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Taborda, O. A.; Tapia, A.; Tartare, M.; Tepe, A.; Theodoro, V. M.; Timmermans, C.; Todero Peixoto, C. J.; Toma, G.; Tomankova, L.; Tomé, B.; Tonachini, A.; Torralba Elipe, G.; Torres Machado, D.; Travnicek, P.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van Bodegom, P.; van den Berg, A. M.; van Velzen, S.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Varner, G.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Verzi, V.; Vicha, J.; Videla, M.; Villaseñor, L.; Vlcek, B.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Widom, A.; Wiencke, L.; Wilczyńska, B.; Wilczyński, H.; Will, M.; Williams, C.; Winchen, T.; Wittkowski, D.; Wundheiler, B.; Wykes, S.; Yamamoto, T.; Yapici, T.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Zhou, J.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.; Zuccarello, F.; Pierre Auger Collaboration*

    2014-12-01

    Using the data taken at the Pierre Auger Observatory between December 2004 and December 2012, we have examined the implications of the distributions of depths of atmospheric shower maximum (Xmax ), using a hybrid technique, for composition and hadronic interaction models. We do this by fitting the distributions with predictions from a variety of hadronic interaction models for variations in the composition of the primary cosmic rays and examining the quality of the fit. Regardless of what interaction model is assumed, we find that our data are not well described by a mix of protons and iron nuclei over most of the energy range. Acceptable fits can be obtained when intermediate masses are included, and when this is done consistent results for the proton and iron-nuclei contributions can be found using the available models. We observe a strong energy dependence of the resulting proton fractions, and find no support from any of the models for a significant contribution from iron nuclei. However, we also observe a significant disagreement between the models with respect to the relative contributions of the intermediate components.

  1. Depth profiling of APTES self-assembled monolayers using surface-enhanced confocal Raman microspectroscopy

    Science.gov (United States)

    Sun, Yingying; Yanagisawa, Masahiro; Kunimoto, Masahiro; Nakamura, Masatoshi; Homma, Takayuki

    2017-09-01

    The internal structure of self-assembled monolayers (SAMs) such as 3-aminopropyltriethoxysilane (APTES) fabricated on a glass substrate is difficult to characterize and analyze at nanometer level. In this study, we employed surface-enhanced Raman spectroscopy (SERS) to study the internal molecular structure of APTES SAMs. The sample APTES SAMs were deposited with Ag nanoparticles to enhance the Raman signal and to obtain subtler structure information, which were supported by density functional theory calculations. In addition, in order to carry out high-resolution analysis, especially for vertical direction, a fine piezo electric positioner was used to control the depth scanning with a step of 0.1 nm. We measured and distinguished the vertical Raman intensity variations of specific groups in APTES, such as Ag/NH2, CH2, and Sisbnd O, with high resolution. The interfacial bond at the two interfaces of Ag-APTES and APTES-SiO2 was identified. Moreover, APTES molecule orientation was demonstrated to be inhomogeneous from frequency shift.

  2. Soil depth profiles and radiological assessment of natural radionuclides in forest ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Manigandan, P.K. [Al Musanna College of Technology, Muscat (Oman); Chandar Shekar, B. [Bharathiar Univ., Coimbatore (India). Kongunadu Arts and Science College

    2017-08-01

    We measured the distribution of three naturally occurring radionuclides, {sup 238}U, {sup 232}Th, and {sup 40}K, in soil samples collected from a rainforest in the Western Ghats of India. For each surface sample, we calculated average activity concentration, outdoor terrestrial γ dose rate, annual effective dose equivalent (AEDE), and radiation hazard index. The activity concentrations of surface samples were randomly distributed over space, but differed slightly with different soil depths. The concentration of {sup 232}Th and the average terrestrial γ dose rates were slightly higher than the world averages, so slightly high γ radiation appears to be a general characteristic of the Western Ghats. However, all radiological hazard indices were within the limits proposed by the International Commission on Radiological Protection. The results reported here indicate that, except for {sup 232}Th, the naturally occurring radionuclides in the forest soils of the Western Ghats were within the ranges specified by United Nations Scientific Committee on the Effects of Atomic Radiation for undisturbed virgin soils.

  3. Depth of maximum of air-shower profiles at the Pierre Auger Observatory. II. Composition implications

    Energy Technology Data Exchange (ETDEWEB)

    Aab, A.; Abreu, P.; Aglietta, M.; Ahn, E. J.; Al Samarai, I.; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Aramo, C.; Aranda, V. M.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Awal, N.; Badescu, A. M.; Barber, K. B.; Bäuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertania, M. E.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blaess, S.; Blanco, M.; Bleve, C.; Blümer, H.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Bridgeman, A.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Buitink, S.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Candusso, M.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Chavez, A. G.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Coleman, A.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cooper, M. J.; Cordier, A.; Coutu, S.; Covault, C. E.; Cronin, J.; Curutiu, A.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; de Jong, S. J.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Di Matteo, A.; Diaz, J. C.; Díaz Castro, M. L.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D’Olivo, J. C.; Dorofeev, A.; Dorosti Hasankiadeh, Q.; Dova, M. T.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fernandes, M.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipčič, A.; Fox, B. D.; Fratu, O.; Fröhlich, U.; Fuchs, B.; Fuji, T.; Gaior, R.; García, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Gascon Bravo, A.; Gate, F.; Gemmeke, H.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Glaser, C.; Glass, H.; Gómez Berisso, M.; Gómez Vitale, P. F.; Gonçalves, P.; Gonzalez, J. G.; González, N.; Gookin, B.; Gordon, J.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grebe, S.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guarino, F.; Guedes, G. P.; Hampel, M. R.; Hansen, P.; Harari, D.; Harrison, T. A.; Hartmann, S.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holt, E.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huber, D.; Huege, T.; Insolia, A.; Isar, P. G.; Jandt, I.; Jansen, S.; Jarne, C.; Josebachuili, M.; Kääpä, A.; Kambeitz, O.; Kampert, K. H.; Kasper, P.; Katkov, I.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Krömer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kunka, N.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Le Coz, S.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Lopez Agüera, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Malacari, M.; Maldera, S.; Mallamaci, M.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Mariş, I. C.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martínez Bravo, O.; Martraire, D.; Masías Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Meissner, R.; Melissas, M.; Melo, D.; Menshikov, A.; Messina, S.; Meyhandan, R.; Mićanović, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morello, C.; Mostafá, M.; Moura, C. A.; Muller, M. A.; Müller, G.; Müller, S.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nguyen, P.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nožka, L.; Ochilo, L.; Olinto, A.; Oliveira, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Papenbreer, P.; Parente, G.; Parra, A.; Paul, T.; Pech, M.; Pȩkala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Petermann, E.; Peters, C.; Petrera, S.; Petrov, Y.; Phuntsok, J.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porcelli, A.; Porowski, C.; Prado, R. R.; Privitera, P.; Prouza, M.; Purrello, V.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rizi, V.; Rodrigues de Carvalho, W.; Rodriguez Cabo, I.; Rodriguez Fernandez, G.; Rodriguez Rojo, J.; Rodríguez-Frías, M. D.; Rogozin, D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Roulet, E.; Rovero, A. C.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Saleh, A.; Salesa Greus, F.; Salina, G.; Sánchez, F.; Sanchez-Lucas, P.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarmento, R.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, D.; Scholten, O.; Schoorlemmer, H.; Schovánek, P.; Schulz, A.; Schulz, J.; Schumacher, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Sima, O.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Squartini, R.; Srivastava, Y. N.; Stanič, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Taborda, O. A.; Tapia, A.; Tartare, M.; Tepe, A.; Theodoro, V. M.; Timmermans, C.; Todero Peixoto, C. J.; Toma, G.; Tomankova, L.; Tomé, B.; Tonachini, A.; Torralba Elipe, G.; Torres Machado, D.; Travnicek, P.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van Bodegom, P.; van den Berg, A. M.; van Velzen, S.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Varner, G.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Verzi, V.; Vicha, J.; Videla, M.; Villaseñor, L.; Vlcek, B.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Widom, A.; Wiencke, L.; Wilczyńska, B.; Wilczyński, H.; Will, M.; Williams, C.; Winchen, T.; Wittkowski, D.; Wundheiler, B.; Wykes, S.; Yamamoto, T.; Yapici, T.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Zhou, J.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.; Zuccarello, F.

    2014-12-01

    Using the data taken at the Pierre Auger Observatory between December 2004 and December 2012, we have examined the implications of the distributions of depths of atmospheric shower maximum (Xmax), using a hybrid technique, for composition and hadronic interaction models. We do this by fitting the distributions with predictions from a variety of hadronic interaction models for variations in the composition of the primary cosmic rays and examining the quality of the fit. Regardless of what interaction model is assumed, we find that our data are not well described by a mix of protons and iron nuclei over most of the energy range. Acceptable fits can be obtained when intermediate masses are included, and when this is done consistent results for the proton and iron-nuclei contributions can be found using the available models. We observe a strong energy dependence of the resulting proton fractions, and find no support from any of the models for a significant contribution from iron nuclei. However, we also observe a significant disagreement between the models with respect to the relative contributions of the intermediate components.

  4. Efeito da profundidade de soldagem no hidrogênio difusível de soldas molhadas Effect of water depth on diffusible hydrogen on wet welds

    Directory of Open Access Journals (Sweden)

    Weslley Carlos Dias da Silva

    2012-12-01

    Full Text Available Em soldagem subaquática molhada, a ocorrência de poros e trincas a frio pode ter um efeito bastante prejudicial nas propriedades mecânicas da junta soldada. O hidrogênio contribui diretamente para o aparecimento destas duas descontinuidades. A quantidade de hidrogênio difusível (Hdif no metal de solda pode ser influenciada por diversos fatores. Todavia, pouco se sabe sobre a influência da profundidade de soldagem (pressão sobre a quantidade de Hdif no metal de solda. Neste trabalho, diversas medições de hidrogênio difusível foram feitas nas profundidades de 0,30 m, 10 m e 20 m e 30 m em soldagem molhada. O consumível utilizado foi o eletrodo comercial E6013 envernizado. As medições de hidrogênio difusível foram feitas através do método da cromatografia. Para medição de porosidade foi utilizado o método macrográfico e um programa analisador de imagem. O hidrogênio residual também foi medido. Os resultados mostraram que o hidrogênio difusível reduziu significativamente com o aumento da pressão hidrostática ao contrário da porosidade, que aumentou com o aumento da pressão hidrostática. Não se observou alterações apreciáveis no hidrogênio residual do metal de solda. Desta forma, é possível concluir que a profundidade de soldagem afeta diversos aspectos da soldagem subaquática molhada, em especial, o hidrogênio difusível e porosidade, conforme foi observado neste trabalho.In underwater wet welding, cold cracking and pores might have a deleterious effect in the mechanical properties of welded joint. The hydrogen might act in the occurrence of theses discontinuities. The amount of diffusible hydrogen in the weld metal can be influenced by several factors. However, not yet known whether the depth of welding (pressure affects the amount of diffusible hydrogen in weld metal. In this work, several measurements of diffusible hydrogen were made at following depth: 0.30 m, 10 m, 20 m and 30 m atwet welding. The

  5. Medical education and communication companies: an updated in-depth profile.

    Science.gov (United States)

    Golden, Gil A; Parochka, Jacqueline N; Overstreet, Karen M

    2002-01-01

    The integrity of medical education and communication companies (MECCs) and their role in continuing medical education (CME) are frequently challenged, perhaps because of a lack of published information characterizing these providers. Published in 1998, a survey of MECCs began the identification and description of these organizations so that meaningful conclusions could be drawn about their role in CME. The present study enhances the profile created by that original survey. A 21-item questionnaire was mailed to 182 companies identified from 3 commercially available lists. Forty-six (25.2%) companies responded. Surveys revealed that 25 (54%) of the respondent companies have 1 to 25 employees, 66.6% have separate CME divisions, 64.4% are accredited to provide CME, 77.7% have at least 1 licensed health care professional on staff, and 33.2% of their leaders hold a doctoral degree and 28.8% hold professional licensure, whereas 88.6% have advisory boards, 93.1% of which review each CME activity. MECCs comprise a diverse group differing in size and accreditation status. They contribute to the CME community by providing a variety of services, with highly trained staff. Future studies of CME providers should continue to expand the base of knowledge regarding these organizations, resulting in better understanding among all types of providers, opportunities for collaboration, and, ultimately, education that improves patient care.

  6. Magnetic depth profile in GaMnAs layers with vertically graded Mn concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Leiner, J., E-mail: leinerjc@ornl.gov [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Kirby, B.J. [Center for Neutron Research, NIST, Gaithersburg, MD 20899 (United States); Fitzsimmons, M.R. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Tivakornsasithorn, K. [Department of Physics, Faculty of Science, Mahidol Univeristy, Bangkok 10400 (Thailand); Liu, X.; Furdyna, J.K.; Dobrowolska, M. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States)

    2014-01-15

    Controlled vertical grading of magnetization of the ferromagnetic semiconductor GaMnAs represents a significant step toward optimizing its magnetic properties for device applications. Quantitative control of such grading is difficult due to various competing effects, such as Mn diffusion, self-annealing, and diffusion of charge carriers. Furthermore, there are also several surface effects that can influence the magnetization profile, which should be considered in designing and fabricating graded GaMnAs specimens. However, we show that vertical magnetization gradients in GaMnAs layers can be readily achieved by appropriate growth strategies. In this paper we describe the preparation, magnetization measurements, and polarized neutron reflectometry studies of vertically graded GaMnAs layers, which provide direct evidence that vertical grading of Mn concentration has been successfully achieved in our GaMnAs samples. Our measurements also indicate that these graded samples exhibit magnetic “hardening” near the surface. - Highlights: • Controlled vertical grading of the magnetization ferromagnetic semiconductors represents a significant step toward optimizing its magnetic properties for device applications. • Quantitative control of such grading is difficult due to various competing effects, such as Mn diffusion, self-annealing, and diffusion of charge carriers. • We show (via SQUID and Polarized Neutron Scattering) that vertical magnetization gradients in GaMnAs layers can be readily achieved by appropriate MBE growth strategies. • Our measurements also indicate that these graded samples exhibit magnetic “hardening” near the surface.

  7. Hydrogen.

    Science.gov (United States)

    Bockris, John O'M

    2011-11-30

    The idea of a "Hydrogen Economy" is that carbon containing fuels should be replaced by hydrogen, thus eliminating air pollution and growth of CO₂ in the atmosphere. However, storage of a gas, its transport and reconversion to electricity doubles the cost of H₂ from the electrolyzer. Methanol made with CO₂ from the atmosphere is a zero carbon fuel created from inexhaustible components from the atmosphere. Extensive work on the splitting of water by bacteria shows that if wastes are used as the origin of feed for certain bacteria, the cost for hydrogen becomes lower than any yet known. The first creation of hydrogen and electricity from light was carried out in 1976 by Ohashi et al. at Flinders University in Australia. Improvements in knowledge of the structure of the semiconductor-solution system used in a solar breakdown of water has led to the discovery of surface states which take part in giving rise to hydrogen (Khan). Photoelectrocatalysis made a ten times increase in the efficiency of the photo production of hydrogen from water. The use of two electrode cells; p and n semiconductors respectively, was first introduced by Uosaki in 1978. Most photoanodes decompose during the photoelectrolysis. To avoid this, it has been necessary to create a transparent shield between the semiconductor and its electronic properties and the solution. In this way, 8.5% at 25 °C and 9.5% at 50 °C has been reached in the photo dissociation of water (GaP and InAs) by Kainthla and Barbara Zeleney in 1989. A large consortium has been funded by the US government at the California Institute of Technology under the direction of Nathan Lewis. The decomposition of water by light is the main aim of this group. Whether light will be the origin of the post fossil fuel supply of energy may be questionable, but the maximum program in this direction is likely to come from Cal. Tech.

  8. DMD-based software-configurable spatially-offset Raman spectroscopy for spectral depth-profiling of optically turbid samples.

    Science.gov (United States)

    Liao, Zhiyu; Sinjab, Faris; Gibson, Graham; Padgett, Miles; Notingher, Ioan

    2016-06-13

    Spectral depth-profiling of optically turbid samples is of high interest to a broad range of applications. We present a method for measuring spatially-offset Raman spectroscopy (SORS) over a range of length scales by incorporating a digital micro-mirror device (DMD) into a sample-conjugate plane in the detection optical path. The DMD can be arbitrarily programmed to collect/reject light at spatial positions in the 2D sample-conjugate plane, allowing spatially offset Raman measurements. We demonstrate several detection geometries, including annular and simultaneous multi-offset modalities, for both macro- and micro-SORS measurements, all on the same instrument. Compared to other SORS modalities, DMD-based SORS provides more flexibility with only minimal additional experimental complexity for subsurface Raman collection.

  9. Quantitative analysis of Si1-xGex alloy films by SIMS and XPS depth profiling using a reference material

    Science.gov (United States)

    Oh, Won Jin; Jang, Jong Shik; Lee, Youn Seoung; Kim, Ansoon; Kim, Kyung Joong

    2018-02-01

    Quantitative analysis methods of multi-element alloy films were compared. The atomic fractions of Si1-xGex alloy films were measured by depth profiling analysis with secondary ion mass spectrometry (SIMS) and X-ray Photoelectron Spectroscopy (XPS). Intensity-to-composition conversion factor (ICF) was used as a mean to convert the intensities to compositions instead of the relative sensitivity factors. The ICFs were determined from a reference Si1-xGex alloy film by the conventional method, average intensity (AI) method and total number counting (TNC) method. In the case of SIMS, although the atomic fractions measured by oxygen ion beams were not quantitative due to severe matrix effect, the results by cesium ion beam were very quantitative. The quantitative analysis results by SIMS using MCs2+ ions are comparable to the results by XPS. In the case of XPS, the measurement uncertainty was highly improved by the AI method and TNC method.

  10. Massively parallel signature sequencing (MPSS) as a tool for in-depth quantitative gene expression profiling in all organisms.

    Science.gov (United States)

    Reinartz, Jeanette; Bruyns, Eddy; Lin, Jing-Zhong; Burcham, Tim; Brenner, Sydney; Bowen, Ben; Kramer, Michael; Woychik, Rick

    2002-02-01

    Massively parallel signature sequencing (MPSS) is one of the newest tools available for conducting in-depth expression profiling. MPSS is an open-ended platform that analyses the level of expression of virtually all genes in a sample by counting the number of individual mRNA molecules produced from each gene. There is no requirement that genes be identified and characterised prior to conducting an experiment. MPSS has a routine sensitivity at a level of a few molecules of mRNA per cell, and the datasets are in a digital format that simplifies the management and analysis of the data. Therefore, of the various microarray and non-microarray technologies currently available, MPSS provides many advantages for generating the type of complete datasets that will help to facilitate hypothesis-driven experiments in the era of digital biology.

  11. Bayesian inversion of a CRN depth profile to infer Quaternary erosion of the northwestern Campine Plateau (NE Belgium)

    Science.gov (United States)

    Laloy, Eric; Beerten, Koen; Vanacker, Veerle; Christl, Marcus; Rogiers, Bart; Wouters, Laurent

    2017-07-01

    The rate at which low-lying sandy areas in temperate regions, such as the Campine Plateau (NE Belgium), have been eroding during the Quaternary is a matter of debate. Current knowledge on the average pace of landscape evolution in the Campine area is largely based on geological inferences and modern analogies. We performed a Bayesian inversion of an in situ-produced 10Be concentration depth profile to infer the average long-term erosion rate together with two other parameters: the surface exposure age and the inherited 10Be concentration. Compared to the latest advances in probabilistic inversion of cosmogenic radionuclide (CRN) data, our approach has the following two innovative components: it (1) uses Markov chain Monte Carlo (MCMC) sampling and (2) accounts (under certain assumptions) for the contribution of model errors to posterior uncertainty. To investigate to what extent our approach differs from the state of the art in practice, a comparison against the Bayesian inversion method implemented in the CRONUScalc program is made. Both approaches identify similar maximum a posteriori (MAP) parameter values, but posterior parameter and predictive uncertainty derived using the method taken in CRONUScalc is moderately underestimated. A simple way for producing more consistent uncertainty estimates with the CRONUScalc-like method in the presence of model errors is therefore suggested. Our inferred erosion rate of 39 ± 8. 9 mm kyr-1 (1σ) is relatively large in comparison with landforms that erode under comparable (paleo-)climates elsewhere in the world. We evaluate this value in the light of the erodibility of the substrate and sudden base level lowering during the Middle Pleistocene. A denser sampling scheme of a two-nuclide concentration depth profile would allow for better inferred erosion rate resolution, and including more uncertain parameters in the MCMC inversion.

  12. Hydrogen

    Directory of Open Access Journals (Sweden)

    John O’M. Bockris

    2011-11-01

    Full Text Available The idea of a “Hydrogen Economy” is that carbon containing fuels should be replaced by hydrogen, thus eliminating air pollution and growth of CO2 in the atmosphere. However, storage of a gas, its transport and reconversion to electricity doubles the cost of H2 from the electrolyzer. Methanol made with CO2 from the atmosphere is a zero carbon fuel created from inexhaustible components from the atmosphere. Extensive work on the splitting of water by bacteria shows that if wastes are used as the origin of feed for certain bacteria, the cost for hydrogen becomes lower than any yet known. The first creation of hydrogen and electricity from light was carried out in 1976 by Ohashi et al. at Flinders University in Australia. Improvements in knowledge of the structure of the semiconductor-solution system used in a solar breakdown of water has led to the discovery of surface states which take part in giving rise to hydrogen (Khan. Photoelectrocatalysis made a ten times increase in the efficiency of the photo production of hydrogen from water. The use of two electrode cells; p and n semiconductors respectively, was first introduced by Uosaki in 1978. Most photoanodes decompose during the photoelectrolysis. To avoid this, it has been necessary to create a transparent shield between the semiconductor and its electronic properties and the solution. In this way, 8.5% at 25 °C and 9.5% at 50 °C has been reached in the photo dissociation of water (GaP and InAs by Kainthla and Barbara Zeleney in 1989. A large consortium has been funded by the US government at the California Institute of Technology under the direction of Nathan Lewis. The decomposition of water by light is the main aim of this group. Whether light will be the origin of the post fossil fuel supply of energy may be questionable, but the maximum program in this direction is likely to come from Cal. Tech.

  13. Unveiled electric profiles within hydrogen bonds suggest DNA base pairs with similar bond strengths.

    Directory of Open Access Journals (Sweden)

    Y B Ruiz-Blanco

    Full Text Available Electrical forces are the background of all the interactions occurring in biochemical systems. From here and by using a combination of ab-initio and ad-hoc models, we introduce the first description of electric field profiles with intrabond resolution to support a characterization of single bond forces attending to its electrical origin. This fundamental issue has eluded a physical description so far. Our method is applied to describe hydrogen bonds (HB in DNA base pairs. Numerical results reveal that base pairs in DNA could be equivalent considering HB strength contributions, which challenges previous interpretations of thermodynamic properties of DNA based on the assumption that Adenine/Thymine pairs are weaker than Guanine/Cytosine pairs due to the sole difference in the number of HB. Thus, our methodology provides solid foundations to support the development of extended models intended to go deeper into the molecular mechanisms of DNA functioning.

  14. Depth profiles of the Doppler-broadening S parameter for polymers obtained with two measuring patterns: The role of accumulated charges

    Energy Technology Data Exchange (ETDEWEB)

    Yang, J. [Key Laboratory of Nuclear Radiation and Nuclear Energy Technology, Institute of High Energy Physics, Chinese Academy of Sciences, No. 19 Yuquan Lu, Beijing 100049 (China); University of Chinese Academy of Sciences, Beijing 100039 (China); Zhang, P.; Lu, E.Y.; Cao, X.Z.; Yu, R.S. [Key Laboratory of Nuclear Radiation and Nuclear Energy Technology, Institute of High Energy Physics, Chinese Academy of Sciences, No. 19 Yuquan Lu, Beijing 100049 (China); Wang, B.Y., E-mail: wangboy@ihep.ac.cn [Key Laboratory of Nuclear Radiation and Nuclear Energy Technology, Institute of High Energy Physics, Chinese Academy of Sciences, No. 19 Yuquan Lu, Beijing 100049 (China)

    2014-03-15

    Highlights: • Depth profiles of S parameter for polymers were obtained with two patterns. • Charges induced by high energy incident positrons can influenced the depth profile. • Depth profiles obtained with energy increase pattern can give real characteristics. - Abstract: Depth profiles of Doppler broadening S parameter for oxygen containing polymer polycarbonate (PC), fluoropolymer poly (tetrafluoroethylene) (PTFE) and chlorine containing polymer polyvinylchloride-unplasticized (UPVC) were obtained with two measuring patterns, i.e. energy increase pattern and energy decrease pattern. The two curves can’t coincide with each other for that a trough appeared between 1 and 5 keV in the curve obtained with energy decrease pattern. It was found that charges induced by high energy incident positrons greatly influenced the annihilation of low energy incident positrons, while charges induced by low energy incident positrons showed little influence on the annihilation of high energy incident positrons. With energy increase measuring pattern, charges induced by low energy incident positrons showed little influence on the annihilation of later incident high energy positrons, thus the measurement can give the depth profile of S parameter in polymer as it was.

  15. Depth-related changes in community structure of culturable mineral weathering bacteria and in weathering patterns caused by them along two contrasting soil profiles.

    Science.gov (United States)

    Huang, Jing; Sheng, Xia-Fang; Xi, Jun; He, Lin-Yan; Huang, Zhi; Wang, Qi; Zhang, Zhen-Dong

    2014-01-01

    Bacteria play important roles in mineral weathering and soil formation. However, few reports of mineral weathering bacteria inhabiting subsurfaces of soil profiles have been published, raising the question of whether the subsurface weathering bacteria are fundamentally distinct from those in surface communities. To address this question, we isolated and characterized mineral weathering bacteria from two contrasting soil profiles with respect to their role in the weathering pattern evolution, their place in the community structure, and their depth-related changes in these two soil profiles. The effectiveness and pattern of bacterial mineral weathering were different in the two profiles and among the horizons within the respective profiles. The abundance of highly effective mineral weathering bacteria in the Changshu profile was significantly greater in the deepest horizon than in the upper horizons, whereas in the Yanting profile it was significantly greater in the upper horizons than in the deeper horizons. Most of the mineral weathering bacteria from the upper horizons of the Changshu profile and from the deeper horizons of the Yanting profile significantly acidified the culture media in the mineral weathering process. The proportion of siderophore-producing bacteria in the Changshu profile was similar in all horizons except in the Bg2 horizon, whereas the proportion of siderophore-producing bacteria in the Yanting profile was higher in the upper horizons than in the deeper horizons. Both profiles existed in different highly depth-specific culturable mineral weathering community structures. The depth-related changes in culturable weathering communities were primarily attributable to minor bacterial groups rather than to a change in the major population structure.

  16. Comparative study of the usefulness of low energy Cs(+), Xe(+), and O(2)(+) ions for depth profiling amino-acid and sugar films.

    Science.gov (United States)

    Wehbe, Nimer; Houssiau, Laurent

    2010-12-15

    This work reports a comparative study on the capability of low energy primary ion beams for depth profiling nonpolymeric molecules including amino-acid and sugar layers. Due to their different behavior regarding depth profiling, phenylalanine and trehalose molecules are chosen as reference systems. Each molecule was dissolved in suitable solvent prior to spin-coating on clean silicon wafer. The film thicknesses were in the order of 70 and 100 nm for phenylalanine and trehalose respectively. Depth profiling feasibility were assessed first using Cs(+) as reactive sputtering ion at various energies. The results obtained under Cs(+) sputtering ions are compared afterward to those obtained under Xe(+) sputtering ions which are inert and have a mass very similar to Cs(+). In order to investigate the effect of oxygen, depth profiling are also performed using either Xe(+) under oxygen flooding or O(2)(+) as sputtering ions. While phenylalanine could be depth profiled successfully using Cs(+) ions, Xe(+) and O(2)(+) ions failed to retain any characteristic signal. The sputtering yields measured as a function of the ion beam energies were higher using Cs(+), in particular at low energies. The chemical reactivity of the cesium atoms being implanted during the sputtering process helps to prevent the loss of the molecular phenylalanine signal. In contrast, depth profiling of trehalose was more successful upon Xe(+) and O(2)(+) compared to Cs(+). In this case the sputtering yields were higher if Xe(+) primary ion is employed instead of Cs(+). The different trends observed in this study are interpreted using arguments involving the reactivity of the sputtering ions.

  17. Depth profiling Li in electrode materials of lithium ion battery by 7Li(p,γ)8Be and 7Li(p,α)4He nuclear reactions

    Science.gov (United States)

    Sunitha, Y.; Kumar, Sanjiv

    2017-06-01

    A proton induced γ-ray emission method based on 7Li(p,γ)8Be proton capture reaction and a nuclear reaction analysis method involving 7Li(p,α)4He reaction are described for depth profiling Li in the electrode materials, graphite and lithium cobalt oxide for example, of a Li-ion battery. Depth profiling by 7Li(p,γ)8Be reaction is accomplished by the resonance at 441 keV and involves the measurement of 14.6 and 17.6 MeV γ-rays, characteristic of the reaction, by a NaI(Tl) detector. The method has a detection sensitivity of ˜0.2 at% and enables profiling up to a depth ≥20 μm with a resolution of ≥150 nm. The profiling to a fairly large depth is facilitated by the absence of any other resonance up to 1800 keV proton energy. The reaction has substantial off-resonance cross-sections. A procedure is outlined for evaluating the off-resonance yields. Interferences from fluorine and aluminium are major limitation of this depth profiling methodology. The depth profile measurement by 7Li(p,α)4He reaction, on the other hand, utilises 2-3 MeV protons and entails the detection of α-particles at 90° or 150° angles. The reaction exhibits inverse kinematics at 150°. This method, too, suffers interference from fluorine due to the simultaneous occurrence of 19F(p,α)16O reaction. Kinematical considerations show that the interference is minimal at 90° and thus is the recommended angle of detection. The method is endowed with a detection sensitivity of ˜0.1 at%, a depth resolution of ˜100 nm and a probing depth of about 30 μm in the absence and 5-8 μm in the presence of fluorine in the material. Both methods yielded comparable depth profiles of Li in the cathode (lithium cobalt oxide) and the anode (graphite) of a Li-ion battery.

  18. Depth profiling the solid electrolyte interphase on lithium titanate (Li4Ti5O12) using synchrotron-based photoelectron spectroscopy

    DEFF Research Database (Denmark)

    Nordh, Tim; Younesi, Reza; Brandell, Daniel

    2015-01-01

    The presence of a surface layer on lithium titanate (Li4Ti5O12, LTO) anodes, which has been a topic of debate in scientific literature, is here investigated with tunable high surface sensitive synchrotron-based photoelectron spectroscopy (PES) to obtain a reliable depth profile of the interphase....... electrode as such, and an electrode soaked in the electrolyte were analyzed by varying the photon energies enabling depth profiling of the outermost surface layer. The main components of the surface layer were found to be ethers, P-O containing compounds, and lithium fluoride....

  19. Time Variations of Observed Hα Line Profiles and Precipitation Depths of Nonthermal Electrons in a Solar Flare

    Science.gov (United States)

    Falewicz, Robert; Radziszewski, Krzysztof; Rudawy, Paweł; Berlicki, Arkadiusz

    2017-10-01

    We compare time variations of the Hα and X-ray emissions observed during the pre-impulsive and impulsive phases of the C1.1-class solar flare on 2013 June 21 with those of plasma parameters and synthesized X-ray emission from a 1D hydrodynamic numerical model of the flare. The numerical model was calculated assuming that the external energy is delivered to the flaring loop by nonthermal electrons (NTEs). The Hα spectra and images were obtained using the Multi-channel Subtractive Double Pass spectrograph with a time resolution of 50 ms. The X-ray fluxes and spectra were recorded by RHESSI. Pre-flare geometric and thermodynamic parameters of the model and the delivered energy were estimated using RHESSI data. The time variations of the X-ray light curves in various energy bands and those of the Hα intensities and line profiles were well correlated. The timescales of the observed variations agree with the calculated variations of the plasma parameters in the flaring loop footpoints, reflecting the time variations of the vertical extent of the energy deposition layer. Our result shows that the fast time variations of the Hα emission of the flaring kernels can be explained by momentary changes of the deposited energy flux and the variations of the penetration depths of the NTEs.

  20. Formation of blade and slot die coated small molecule multilayers for OLED applications studied theoretically and by XPS depth profiling

    Directory of Open Access Journals (Sweden)

    Katharina Peters

    2016-06-01

    Full Text Available Slot die coaters especially designed for low material consumption and doctor blades were used to process small molecule solutions for organic light-emitting diodes (OLEDs. Optimum process parameters were developed for the large-scale coating techniques to generate stable single and multiple layers only a few nanometers thick. Achieving a multilayer architecture for solution-processed OLEDs is the most challenging step. X-ray photoelectron spectroscopy sputter depth profiling was performed to determine defined interfaces between coated organic layers. Commercially available small molecules NPB (N,N’-Di(1-naphthyl-N,N’-diphenyl-(1,1’-biphenyl-4,4’-diamine and BAlq (Bis(8-hdroxy-2methylquinoline-(4-phenylphenoxyaluminum, originally developed for vacuum deposition, were used as hole, respectively electron transport material. Defined double-layers were processed with both scalable coating methods using the orthogonal solvent approach. The use of non-orthogonal solvents resulted in complete intermixing of the material. The results are explained by calculations of solubilities and simulating drying and diffusion kinetics of the small molecule solutions.

  1. Neutral Hydrogen Optical Depth near Star-forming Galaxies at z ≈ 2.4 in the Keck Baryonic Structure Survey

    Science.gov (United States)

    Rakic, Olivera; Schaye, Joop; Steidel, Charles C.; Rudie, Gwen C.

    2012-06-01

    We study the interface between galaxies and the intergalactic medium by measuring the absorption by neutral hydrogen in the vicinity of star-forming galaxies at z ≈ 2.4. Our sample consists of 679 rest-frame UV-selected galaxies with spectroscopic redshifts that have impact parameters 3σ level, out to at least 2.8 Mpc (i.e., >9 comoving Mpc), but the scatter at a given distance is large compared with the median excess optical depth, suggesting that the gas is clumpy. Within 100 (200) kpc, and over ±165 km s-1, the covering fraction of gas with Lyα optical depth greater than unity is 100+0 - 32% (66% ± 16%). Absorbers with τLyα > 0.1 are typically closer to galaxies than random. The mean galaxy overdensity around absorbers increases with the optical depth and also as the length scale over which the galaxy overdensity is evaluated is decreased. Absorbers with τLyα ~ 1 reside in regions where the galaxy number density is close to the cosmic mean on scales >=0.25 Mpc. We clearly detect two types of redshift space anisotropies. On scales effect may be due to redshift errors, but is probably dominated by gas motions within or very close to the halos. On the other hand, on scales of 1.4-2.0 Mpc the absorption is compressed along the line of sight (with >3σ significance), an effect that we attribute to large-scale infall (i.e., the Kaiser effect). Based on data obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA, and was made possible by the generous financial support of the W. M. Keck Foundation.

  2. Condensed-Phase Processes during Solid Propellant Combustion. 3. Preliminary Depth-Profiling Studies on XM39, JA2, M9, M30, and HMX2

    Science.gov (United States)

    1994-01-01

    Abrasive blasting was carried out ,Jsing an abrasive blaster manufactured by S. S. White Dental Mfg. Company and referred to in the literature...the liquid layer. Additional ways of obtaining improved depth profiling of the burned layers are also being explored; these include microabrasive

  3. Depth of maximum of air-shower profiles at the Pierre Auger Observatory. I. Measurements at energies above 10(17.8) eV

    NARCIS (Netherlands)

    Aab, A.; Abreu, P.; Aglietta, M.; Ahn, E. J.; Al Samarai, I.; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muniz, J.; Batista, R. Alves; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Aramo, C.; Aranda, V. M.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Awal, N.; Badescu, A. M.; Barber, K. B.; Baeuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertaina, M. E.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blaess, S.; Blanco, M.; Bleve, C.; Bluemer, H.; Bohacova, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Bridgeman, A.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Buitink, S.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Candusso, M.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Chavez, A. G.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Coleman, A.; Collica, L.; Coluccia, M. R.; Conceicao, R.; Contreras, F.; Cooper, M. J.; Cordier, A.; Coutu, S.; Covault, C. E.; Cronin, J.; Curutiu, A.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; de Jong, S. J.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Di Matteo, A.; Diaz, J. C.; Diaz Castro, M. L.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dorofeev, A.; Hasankiadeh, Q. Dorosti; Dova, M. T.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Luis, P. Facal San; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fernandes, M.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipcic, A.; Fox, B. D.; Fratu, O.; Froehlich, U.; Fuchs, B.; Fujii, T.; Gaior, R.; Garcia, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Gascon Bravo, A.; Gate, F.; Gemmeke, H.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Glaser, C.; Glass, H.; Gomez Berisso, M.; Gomez Vitale, P. F.; Goncalves, P.; Gonzalez, J. G.; Gonzalez, N.; Gookin, B.; Gordon, J.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grebe, S.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guarino, F.; Guedes, G. P.; Hampel, M. R.; Hansen, P.; Harari, D.; Harrison, T. A.; Hartmann, S.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holt, E.; Homola, P.; Hoerandel, J. R.; Horvath, P.; Hrabovsky, M.; Huber, D.; Huege, T.; Insolia, A.; Isar, P. G.; Jandt, I.; Jansen, S.; Jarne, C.; Josebachuili, M.; Kaeaepae, A.; Kambeitz, O.; Kampert, K. H.; Kasper, P.; Katkov, I.; Kegl, B.; Keilhauer, B.; Keivani, A.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Kroemer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kunka, N.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Le Coz, S.; Leao, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; Lopez, R.; Lopez Agueera, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Malacari, M.; Maldera, S.; Mallamaci, M.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Maris, I. C.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martinez Bravo, O.; Martraire, D.; Masias Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Meissner, R.; Melissas, M.; Melo, D.; Menshikov, A.; Messina, S.; Meyhandan, R.; Micanovic, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Ragaigne, D. Monnier; Montanet, F.; Morello, C.; Mostafa, M.; Moura, C. A.; Muller, M. A.; Mueller, G.; Mueller, S.; Muenchmeyer, M.; Mussa, R.; Navarra, G.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nguyen, P.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nozka, L.; Ochilo, L.; Olinto, A.; Oliveira, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Papenbreer, P.; Parente, G.; Parra, A.; Paul, T.; Pech, M.; Pekala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Petermann, E.; Peters, C.; Petrera, S.; Petrov, Y.; Phuntsok, J.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porcelli, A.; Porowski, C.; Prado, R. R.; Privitera, P.; Prouza, M.; Purrello, V.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rizi, V.; Rodrigues de Carvalho, W.; Rodriguez Cabo, I.; Rodriguez Fernandez, G.; Rodriguez Rojo, J.; Rodriguez-Frias, M. D.; Rogozin, D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Roulet, E.; Rovero, A. C.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Saleh, A.; Greus, F. Salesa; Salina, G.; Sanchez, F.; Sanchez-Lucas, P.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarmento, R.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, D.; Scholten, O.; Schoorlemmer, H.; Schovanek, P.; Schulz, A.; Schulz, J.; Schumacher, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Sima, O.; Smialkowski, A.; Smida, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Squartini, R.; Srivastava, Y. N.; Stanic, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Stutz, A.; Suarez, F.; Suomijaervi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Taborda, O. A.; Tapia, A.; Tartare, M.; Tepe, A.; Theodoro, V. M.; Timmermans, C.; Peixoto, C. J. Todero; Toma, G.; Tomankova, L.; Tome, B.; Tonachini, A.; Torralba Elipe, G.; Torres Machado, D.; Travnicek, P.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdes Galicia, J. F.; Valino, I.; Valore, L.; van Aar, G.; van Bodegom, P.; van den Berg, A. M.; van Velzen, S.; van Vliet, A.; Varela, E.; Vargas Cardenas, B.; Varner, G.; Vazquez, J. R.; Vazquez, R. A.; Veberic, D.; Verzi, V.; Vicha, J.; Videla, M.; Villasenor, L.; Vlcek, B.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Widom, A.; Wiencke, L.; Wilczynska, B.; Wilczynski, H.; Will, M.; Williams, C.; Winchen, T.; Wittkowski, D.; Wundheiler, B.; Wykes, S.; Yamamoto, T.; Yapici, T.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Zhou, J.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.; Zuccarello, F.

    2014-01-01

    We report a study of the distributions of the depth of maximum, X-max, of extensive air-shower profiles with energies above 10(17.8) eV as observed with the fluorescence telescopes of the Pierre Auger Observatory. The analysis method for selecting a data sample with minimal sampling bias is

  4. Depth diversity profile of polychaete worms in Bahía Chatham, Isla del Coco National Park, Costa Rican Pacific

    Directory of Open Access Journals (Sweden)

    Jeffrey A. Sibaja-Cordero

    2012-11-01

    Full Text Available The subtidal benthos of tropical islands has been poorly studied in the Eastern Tropical Pacific. Several studies have been published on taxonomic collections from oceanic islands in the region, but ecological features and community structure are practically unknown. In the present study, composition of the polychaete community along a depth gradient from the sand bottom of Bahía Chatham, Isla del Coco National Park, Costa Rica is analyzed. Fifty species of polychaetes belonging to 28 families were found. There is a peak in diversity, abundance and richness at 28-30m. The lowest values occurred at 50m depth with values increasing below this depth. The composition of species changed with depth with some species being found only at depths either less than or greater than 50m. This pattern can be explained in part by the location of the thermocline that occurred at around 50m depth.

  5. Possibilities of LA-ICP-MS technique for the spatial elemental analysis of the recent fish scales: Line scan vs. depth profiling

    Energy Technology Data Exchange (ETDEWEB)

    Hola, Marketa [Department of Chemistry, Masaryk University of Brno, Kamenice 5, 625 00 Brno (Czech Republic); Kalvoda, Jiri, E-mail: jkalvoda@centrum.cz [Department of Geological Sciences, Masaryk University of Brno, Kotlarska 2, 611 37 Brno (Czech Republic); Novakova, Hana [Department of Chemistry, Masaryk University of Brno, Kamenice 5, 625 00 Brno (Czech Republic); Skoda, Radek [Department of Geological Sciences, Masaryk University of Brno, Kotlarska 2, 611 37 Brno (Czech Republic); Kanicky, Viktor [Department of Chemistry, Masaryk University of Brno, Kamenice 5, 625 00 Brno (Czech Republic)

    2011-01-01

    LA-ICP-MS and solution based ICP-MS in combination with electron microprobe are presented as a method for the determination of the elemental spatial distribution in fish scales which represent an example of a heterogeneous layered bone structure. Two different LA-ICP-MS techniques were tested on recent common carp (Cyprinus carpio) scales: (a)A line scan through the whole fish scale perpendicular to the growth rings. The ablation crater of 55 {mu}m width and 50 {mu}m depth allowed analysis of the elemental distribution in the external layer. Suitable ablation conditions providing a deeper ablation crater gave average values from the external HAP layer and the collagen basal plate. (b)Depth profiling using spot analysis was tested in fish scales for the first time. Spot analysis allows information to be obtained about the depth profile of the elements at the selected position on the sample. The combination of all mentioned laser ablation techniques provides complete information about the elemental distribution in the fish scale samples. The results were compared with the solution based ICP-MS and EMP analyses. The fact that the results of depth profiling are in a good agreement both with EMP and PIXE results and, with the assumed ways of incorporation of the studied elements in the HAP structure, suggests a very good potential for this method.

  6. Possibilities of LA-ICP-MS technique for the spatial elemental analysis of the recent fish scales: Line scan vs. depth profiling

    Science.gov (United States)

    Holá, Markéta; Kalvoda, Jiří; Nováková, Hana; Škoda, Radek; Kanický, Viktor

    2011-01-01

    LA-ICP-MS and solution based ICP-MS in combination with electron microprobe are presented as a method for the determination of the elemental spatial distribution in fish scales which represent an example of a heterogeneous layered bone structure. Two different LA-ICP-MS techniques were tested on recent common carp ( Cyprinus carpio) scales: A line scan through the whole fish scale perpendicular to the growth rings. The ablation crater of 55 μm width and 50 μm depth allowed analysis of the elemental distribution in the external layer. Suitable ablation conditions providing a deeper ablation crater gave average values from the external HAP layer and the collagen basal plate. Depth profiling using spot analysis was tested in fish scales for the first time. Spot analysis allows information to be obtained about the depth profile of the elements at the selected position on the sample. The combination of all mentioned laser ablation techniques provides complete information about the elemental distribution in the fish scale samples. The results were compared with the solution based ICP-MS and EMP analyses. The fact that the results of depth profiling are in a good agreement both with EMP and PIXE results and, with the assumed ways of incorporation of the studied elements in the HAP structure, suggests a very good potential for this method.

  7. A depth-dependent profile of the lipid conformation and lateral packing order of the stratum corneum in vivo measured using Raman microscopy.

    Science.gov (United States)

    Choe, ChunSik; Lademann, Jürgen; Darvin, Maxim E

    2016-03-21

    The intercellular lipid structure of the stratum corneum (SC) plays a key role in skin barrier function. A depth profile of the intercellular lipid conformation and the lipid lateral packing order were measured in vivo in the human SC using confocal Raman microscopy. The depth profiles of the 2880 cm(-1)/2850 cm(-1) peak ratio intensity, which represent the C-H stretching and lateral packing order of lipids, and the 1080 cm(-1)/(1130 cm(-1) + 1060 cm(-1)) peak ratio, which represents the C-C skeleton vibration and trans-gauche conformation order of lipids, were investigated. The influence of keratin on the lipid peaks at 2850 cm(-1) and 2880 cm(-1) was excluded by the developed mathematical algorithm. The results show that the trans-conformation and lateral packing order of the intercellular lipids reach their maximum value in the SC at 20-40% of its depth and then decrease towards the stratum granulosum. These results show that at a depth of 20-40% (normally corresponding to a depth of 4-8 μm) the SC exhibits the most ordered lipids and therefore the highest skin barrier function. The lateral packing of lipids is more disordered on the surface and in the deeper parts of the SC, which may be associated with a reduced skin barrier function.

  8. Analysis of components depth profile at the interface of Ti6242 alloy and TiNi coatings after high temperature oxidation in air

    Energy Technology Data Exchange (ETDEWEB)

    Galdikas, A. [Department of Physics and Mathematics, Kaunas University of Medicine (Lithuania); Riviere, J.P.; Pichon, L. [Laboratoire de Physique des Materiaux, University of Poitiers, Poitiers (France); Petraitiene, A.; Moskalioviene, T. [Physics Department, Kaunas University of Technology, 50 Studentu st., Kaunas (Lithuania)

    2010-11-15

    We have analyzed the interfacial elemental depth profile evolution after high temperature isothermal oxidation of NiTi coatings deposited by dynamic ion mixing on a Ti6242 alloy (Ti-6Al-2Sn-4Zr-2Mo). NiTi coatings (thickness 0.4 {mu}m) were deposited at room temperature (RT) by ion beam sputtering. High temperature isothermal oxidation tests in 1 atm flowing synthetic air (80% N{sub 2}, 20% O{sub 2}) have been conducted at 500 C and 600 C during 100 hours. We have observed a non-monotonous depth distribution of nickel in GDOES depth profiles after oxidation of TiNi/Ti6242: nickel segregates to the surface of TiNi coating and to the interface between TiNi coating and Ti6242 alloy. We propose a kinetic model based on rate equations for analyzing the depth profile. This model includes microprocesses taking place during oxidation in air such as: adsorption of nitrogen and oxygen, diffusion of components through the film and interface, formation of chemical compounds. It is shown by modeling that non-monotonous depth profile of nickel occurs because nickel from TiNi coating is forming a nickel oxide compound when oxygen atoms reach the film/alloy interface. XRD analysis confirms the presence of nickel oxide in the TiNi/Ti6242 interface after oxidation at both temperatures 500 C and 600 C (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. Surface morphology and depth profile study of Cd{sub 1-x}Zn{sub x}Te alloy nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Yilmaz, Ercan, E-mail: yilmaz@ibu.edu.tr [Physics Department, Abant Izzet Baysal University, 14280 Bolu (Turkey); Tugay, Evrin [Physics Department, Middle East Technical University, 06531 Ankara (Turkey); Center for Solar Energy Research and Applications (GUeNAM), Middle East Technical University, 06531 Ankara (Turkey); Aktag, Aliekber [Physics Department, Abant Izzet Baysal University, 14280 Bolu (Turkey); Yildiz, Ilker [Physics Department, Middle East Technical University, 06531 Ankara (Turkey); Parlak, Mehmet; Turan, Rasit [Physics Department, Middle East Technical University, 06531 Ankara (Turkey); Center for Solar Energy Research and Applications (GUeNAM), Middle East Technical University, 06531 Ankara (Turkey)

    2012-12-25

    Highlights: Black-Right-Pointing-Pointer Cd{sub 1-x}Zn{sub x}Te (CZT) films were grown on heated glass at 400 Degree-Sign C from a single target. Black-Right-Pointing-Pointer CZT films were annealed at 300 and 450 Degree-Sign C for 1 h under N{sub 2} gas at atm. pressure. Black-Right-Pointing-Pointer The structural and optical properties of CZT films were studied. Black-Right-Pointing-Pointer Better structural stability and reproducibility in CZT films were succeeded. Black-Right-Pointing-Pointer Uniform and stoichiometric CZT films with required compositions were fabricated. - Abstract: Cd{sub 1-x}Zn{sub x}Te thin films with thickness of 200 nm were deposited on glass substrates from a single sputtering target. During the deposition process, the substrates were heated at 400 Degree-Sign C and deposited films were subjected to an annealing process at 300 and 450 Degree-Sign C for an hour under flowing N{sub 2} gas at atmospheric pressure. Influence of in situ heating and post-deposition annealing treatments on the structural and optical evolution of Cd{sub 1-x}Zn{sub x}Te nanostructures were investigated by diagnostic techniques such as X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and UV-transmission spectroscopy. The transmission spectra in the region of the optical absorption band edge were measured for as-deposited and heat-treated of CdZnTe samples. Band gap of the deposited films were found to be in the range of 1.59-1.66 eV. The XRD studies revealed that heated Cd{sub 1-x}Zn{sub x}Te films have a cubic oriented (1 1 1), (2 2 0) and (3 1 1) polycrystalline structure whereas unheated films are mostly amorphous. The effects of annealing temperature on the composition of the thin films were discussed. XPS measurements were performed in the depth profiling mode in order to understand the variation in the chemical composition of the films

  10. Inverse Ubbelohde effect in the short hydrogen bond of photosystem II: Relation between H/D isotope effect and symmetry in potential energy profile.

    Science.gov (United States)

    Kanematsu, Yusuke; Tachikawa, Masanori; Takano, Yu

    2016-09-05

    The short hydrogen bond between tyrosine Yz and D1-His190 of photosystem II (PSII) was investigated using multicomponent quantum mechanics, where the quantum fluctuation of a hydrogen nucleus was incorporated into electronic structure calculation. Our computation demonstrated that the deuteration for hydrogen in the short hydrogen bond of PSII led to the reduction of the O…N distance. It indicated an inverse Ubbelohde effect typically recognized in strong and symmetric hydrogen-bonding clusters such as FHF(-) and H3O2-. We confirmed that the relation between the geometric isotope effect and the symmetry of the potential energy profile of FHF(-) was reasonably agreed with that of PSII. According to this agreement, the short hydrogen bond in PSII can be regarded as a short strong hydrogen bond. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  11. Depth profiles of radioactive cesium in soil using a scraper plate over a wide area surrounding the Fukushima Dai-ichi Nuclear Power Plant, Japan.

    Science.gov (United States)

    Matsuda, Norihiro; Mikami, Satoshi; Shimoura, Susumu; Takahashi, Junko; Nakano, Masakazu; Shimada, Kiyotaka; Uno, Kiichiro; Hagiwara, Shigetomo; Saito, Kimiaki

    2015-01-01

    During the Fukushima Dai-ichi Nuclear Power Plant (NPP) accident, radioactive cesium was released in the environment and deposited on the soils. Depth profiles of radioactive cesium in contaminated soils provide useful information not only for radiation protection and decontamination operations but also for geoscience and radioecology studies. Soil samples were collected using a scraper plate three times between December 2011 and December 2012 at 84 or 85 locations within a 100-km radius of the Fukushima Dai-ichi NPP. In most of the obtained radioactive cesium depth profiles, it was possible to fit the concentration to a function of mass depth as either an exponential or hyperbolic secant function. By using those functions, following three parameters were estimated: (i) relaxation mass depth β (g cm(-2)), (ii) effective relaxation mass depth βeff (g cm(-2)), which is defined for a hyperbolic secant function as the relaxation mass depth of an equivalent exponential function giving the same air kerma rate at 1 m above the ground as the inventory, and (iii) 1/10 depth L1/10 (cm), at which the soil contains 90% of the inventory. The average β value (wet weight) including ones by hyperbolic secant function in December 2012, was 1.29 times higher than that in December 2011. In fact, it was observed that depth profiles at some study sites deviated from the typical exponential distributions over time. These results indicate the gradual downward migration of radioactive cesium in the soils. The L1/10 values in December 2012 were summarized and presented on a map surrounding the Fukushima Dai-ichi NPP, and the average value of L1/10 was 3.01 cm (n = 82) at this time. It was found that radioactive cesium remained within 5 cm of the ground surface at most study sites (71 sites). The sech function can also be used to estimate the downward migration rate V (kg m(-2) y(-1)). The V values in December 2012 (n = 25) were in good agreement with those found by a

  12. Quantification of groundwater-stream water interactions based on temperature depth profiles under strong upwelling conditions in a sand-bed stream

    Science.gov (United States)

    Gaona, Jaime; Lewandowski, Jörg

    2017-04-01

    The quantification of groundwater-surface water interactions is not only required for budgets but also for an understanding of the complex relations between hyporheic exchange flows (HEF) and the associated chemical and biological processes that take place in hyporheic zones (HZ). Thus, there is a strong need to improve methods for flux estimation.The present study aims to quantify the vertical fluxes across the riverbed from data of temperature depth profiles recorded at the River Schlaube in East Brandenburg, Germany. In order to test the capabilities and limitations of existing methods, fluxes were calculated with an analytical (VFLUX, based on the amplitude attenuation and phase shift analysis) and a numerical (1DTempPro, parametrization based on observed values) approach for heat conduction. We conclude that the strong limitations of the flux estimates are caused by thermal and hydraulic heterogeneities of the sediment properties. Consequently, upscaling of fluxes must include other thermal techniques able to portray the spatial variability of thermal patterns, along with further developments of methods to link thermal depth profiles, thermal patterns of the surface of the streambed and all the other factors involved. Considering time and costs of temperature depth profiles of riverbeds, and the need for multiple devices to cover larger areas, it is additionally tested whether vertical fluxes can be infered from the uppermost temperature sensors of a data set. That would ease hyporheic investigations at larger scales.

  13. Evaluation of different strategies for quantitative depth profile analysis of Cu/NiCu layers and multilayers via pulsed glow discharge - Time of flight mass spectrometry

    Science.gov (United States)

    Muñiz, Rocío; Lobo, Lara; Németh, Katalin; Péter, László; Pereiro, Rosario

    2017-09-01

    There is still a lack of approaches for quantitative depth-profiling when dealing with glow discharges (GD) coupled to mass spectrometric detection. The purpose of this work is to develop quantification procedures using pulsed GD (PGD) - time of flight mass spectrometry. In particular, research was focused towards the depth profile analysis of Cu/NiCu nanolayers and multilayers electrodeposited on Si wafers. PGDs are characterized by three different regions due to the temporal application of power: prepeak, plateau and afterglow. This last region is the most sensitive and so it is convenient for quantitative analysis of minor components; however, major elements are often saturated, even at 30 W of applied radiofrequency power for these particular samples. For such cases, we have investigated two strategies based on a multimatrix calibration procedure: (i) using the afterglow region for all the sample components except for the major element (Cu) that was analyzed in the plateau, and (ii) using the afterglow region for all the elements measuring the ArCu signal instead of Cu. Seven homogeneous certified reference materials containing Si, Cr, Fe, Co, Ni and Cu have been used for quantification. Quantitative depth profiles obtained with these two strategies for samples containing 3 or 6 multilayers (of a few tens of nanometers each layer) were in agreement with the expected values, both in terms of thickness and composition of the layers.

  14. New Professional Profiles and Skills in the Journalistic Field: A Scoping Review and In-Depth Interviews with Professionals in Spain

    Directory of Open Access Journals (Sweden)

    Paula Marques-Hayasaki

    2016-12-01

    Full Text Available The professional profiles and skills related to journalism are adapting to a new paradigm as a consequence of the advent of new technologies - the web 2.0, the end of the monopoly of news production by mass media, etc. This study aims to provide a comprehensive critical mapping of new professional profiles and skills demanded in the field of journalism, based on a scoping review and in-depth interviews with professionals and academics in Spain. The results show a great variety of new profiles and nomenclatures. This is in part because of a significant overlapping in the functions emphasized by them. With regards to skills, the traditional ones are still the most valued by the market, although new competencies are becoming more and more important.

  15. Quantitative reconstruction of Ta/Si multilayer depth profiles obtained by Time-of-Flight-Secondary-Ion-Mass-Spectrometry (ToF-SIMS) using Cs{sup +} ion sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Y. [Department of Physics, Shantou University, 243 Daxue Road, Shantou, 515063 Guangdong (China); Hofmann, S. [Max Planck Institute for Intelligent Systems (formerly MPI for Metals Research), Heisenbergstrasse 3, D-70569 Stuttgart (Germany); Wang, J.Y., E-mail: wangjy@stu.edu.cn [Department of Physics, Shantou University, 243 Daxue Road, Shantou, 515063 Guangdong (China); Chakraborty, B.R. [Sophisticated Instrumentation Division, CSIR-National Physical Laboratory, Dr.K.S. Krishnan Road, New Delhi 110012 (India)

    2015-09-30

    Measured sputter depth profiles of Ta/Si multilayers consisting of 10 alternating layers of Si (10.5 nm thickness) and Ta (7.5 nm thickness) obtained by sputtering with Cs{sup +} ions of 1 keV energy, impinging under an angle of 45°, were re-evaluated by application of the Mixing-Roughness-Information depth (MRI) model for profile reconstruction. To be able to perform the latter, a decrease of the sputtering rate with sputtered depth, a strong and sputtering time dependent matrix effect of the detected Si{sup +} ion intensity as well as preferential sputtering of Si have to be taken into account. The results disclose a similar depth resolution for the Si and Ta layers composed of atomic mixing and roughness contributions. The depth resolution increases with the sputtered depth from 4.2 to 6.8 nm at 50 and 300 s sputtering time, respectively. Except for the first and the last two layers (Nos. 19 and 20), by application of the MRI model a full reconstruction of the measured profiles of the Si and Ta multilayer structure was obtained with a mean error of about ± 5%. - Highlights: • Full MRI model quantification of ToF-SIMS multilayer profiles • Correction for matrix effect and depth dependent sensitivity factor • Correction for composition dependent preferential sputtering effect • Profile representation in true depth scale coordinates based on correction 3 • Disclosing depth dependent depth resolution by atomic mixing and roughness components.

  16. In vivo confocal Raman microscopic determination of depth profiles of the stratum corneum lipid organization influenced by application of various oils.

    Science.gov (United States)

    Choe, ChunSik; Schleusener, Johannes; Lademann, Jürgen; Darvin, Maxim E

    2017-08-01

    The intercellular lipids (ICL) of stratum corneum (SC) play an important role in maintaining the skin barrier function. The lateral and lamellar packing order of ICL in SC is not homogenous, but rather depth-dependent. This study aimed to analyze the influence of the topically applied mineral-derived (paraffin and petrolatum) and plant-derived (almond oil and jojoba oil) oils on the depth-dependent ICL profile ordering of the SC in vivo. Confocal Raman microscopy (CRM), a unique tool to analyze the depth profile of the ICL structure non-invasively, is employed to investigate the interaction between oils and human SC in vivo. The results show that the response of SC to oils' permeation varies in the depths. All oils remain in the upper layers of the SC (0-20% of SC thickness) and show predominated differences of ICL ordering from intact skin. In these depths, skin treated with plant-derived oils shows more disordered lateral and lamellar packing order of ICL than intact skin (poils do not influence the lateral packing order of SC ICL (p>0.1), except plant-derived oils at the depth 30% of SC thickness. In the deeper layers of the SC (60-100% of SC thickness), no difference between ICL lateral packing order of the oil-treated and intact skin can be observed, except that at the depths of 70-90% of the SC thickness, where slight changes with more disorder states are measured for plant-derived oil treated skin (poil types remain in the superficial layers of the SC (0-20% of the SC thickness). Skin treated with mineral- and plant-derived oils shows significantly higher disordered lateral and lamellar packing order of ICL in these layers of the SC compared to intact skin. Plant-derived oils significantly changed the ICL ordering in the depths of 30% and 70-90% of the SC thickness, which is likely due to the penetration of free fatty acids in the deeper layers of the SC. Copyright © 2017 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights

  17. Diurnal variations in depth profiles of UV-induced DNA damage and inhibition of bacterioplankton production in tropical coastal waters

    NARCIS (Netherlands)

    Visser, PM; Poos, JJ; Scheper, BB; Boelen, P; van Duyl, FC

    2002-01-01

    In this study, diurnal changes in bacterial production and DNA damage in bacterio-plankton (measured as cyclobutane pyrimidine dimers, CPDs) incubated in bags at different depths in tropical coastal waters were investigated. The DNA damage and inhibition of the bacterial production was highest at

  18. Depth profiling of the modification induced by high-flux deuterium plasma in tungsten and tungsten–tantalum alloys

    NARCIS (Netherlands)

    Zayachuk, Y.; Manhard, A.; Hoen, M. H. J. 't; Jacob, W.; van Emmichoven, P. A. Zeijlma; Van Oost, G.

    2014-01-01

    The present work reports the results of an experimental study of the depth distribution and fluence dependence of deuterium plasma-induced material modification of tungsten and tungsten–tantalum alloys. Plasma-induced damage was created by exposure to high-flux deuterium plasma in the plasma

  19. In-depth hardness profiles of stainless steel and Ni-Ti endodontic instrument cross-sections by nano-indentation.

    Science.gov (United States)

    Zinelis, S; Akhtar, R; Tsakiridis, P; Watts, D C; Silikas, N

    2008-09-01

    To evaluate the in-depth hardness profiles of Stainless Steel (SS) and nickel titanium (Ni-Ti) endodontic instrument cross-sections using a nano-indentation technique. Three SS (Reamer, K and Hedström) and three Ni-Ti (ProFile, NRT and Liberator) instruments were studied. After embedding and metallographic preparation the in-depth hardness profiles of instrument cross-sections were measured starting from the cutting surface towards the centre to a depth of 2000 nm using an MTS XP nanoindenter with a Berkovich diamond indenter. The results of hardness measurements of outer (near to cutting edge) and inner locations were statistically analyzed by two-way anova followed by SNK test (alpha = 0.05). For all instrument cross-sections the maximum hardness was obtained at the outer surface followed by hardness attenuation towards the centre of the cross section. The statistical analysis of hardness classified the instruments, for both outer and innermost locations, to the following decreasing order: Reamer > K > Hedström > Profile > NRT shank (without thermal treatment) > NRT tip (with thermal treatment) > Liberator. The maximal hardness, at the outer surface of endodontic instruments, can be attributed to the residual stresses developed due to cutting and thermal effects during the manufacturing process. The increased outer layer hardness may have a beneficial effect on the cutting ability and wear resistance of endodontic instruments. All endodontic instruments had a decrease in hardness towards their centre. This implies that the surface hardness of contemporary endodontic instruments is significantly enhanced by the consequences of manufacturing processes.

  20. Chemical weathering of a marine terrace chronosequence, Santa Cruz, California I: Interpreting rates and controls based on soil concentration-depth profiles

    Science.gov (United States)

    White, A.F.; Schulz, M.S.; Vivit, D.V.; Blum, A.E.; Stonestrom, D.A.; Anderson, S.P.

    2008-01-01

    The spatial and temporal changes in element and mineral concentrations in regolith profiles in a chronosequence developed on marine terraces along coastal California are interpreted in terms of chemical weathering rates and processes. In regoliths up to 15 m deep and 226 kyrs old, quartz-normalized mass transfer coefficients indicate non-stoichiometric preferential release of Sr > Ca > Na from plagioclase along with lesser amounts of K, Rb and Ba derived from K-feldspar. Smectite weathering results in the loss of Mg and concurrent incorporation of Al and Fe into secondary kaolinite and Fe-oxides in shallow argillic horizons. Elemental losses from weathering of the Santa Cruz terraces fall within the range of those for other marine terraces along the Pacific Coast of North America. Residual amounts of plagioclase and K-feldspar decrease with terrace depth and increasing age. The gradient of the weathering profile bs is defined by the ratio of the weathering rate, R to the velocity at which the profile penetrates into the protolith. A spreadsheet calculator further refines profile geometries, demonstrating that the non-linear regions at low residual feldspar concentrations at shallow depth are dominated by exponential changes in mineral surface-to-volume ratios and at high residual feldspar concentrations, at greater depth, by the approach to thermodynamic saturation. These parameters are of secondary importance to the fluid flux qh, which in thermodynamically saturated pore water, controls the weathering velocity and mineral losses from the profiles. Long-term fluid fluxes required to reproduce the feldspar weathering profiles are in agreement with contemporary values based on solute Cl balances (qh = 0.025-0.17 m yr-1). During saturation-controlled and solute-limited weathering, the greater loss of plagioclase relative to K-feldspar is dependent on the large difference in their respective solubilities instead of the small difference between their respective

  1. Transcriptomic profiling provides molecular insights into hydrogen peroxide-induced adventitious rooting in mung bean seedlings.

    Science.gov (United States)

    Li, Shi-Weng; Leng, Yan; Shi, Rui-Fang

    2017-02-17

    Hydrogen peroxide (H2O2) has been known to function as a signalling molecule involved in the modulation of various physiological processes in plants. H2O2 has been shown to act as a promoter during adventitious root formation in hypocotyl cuttings. In this study, RNA-Seq was performed to reveal the molecular mechanisms underlying H2O2-induced adventitious rooting. RNA-Seq data revealed that H2O2 treatment greatly increased the numbers of clean reads and expressed genes and abundance of gene expression relative to the water treatment. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses indicated that a profound change in gene function occurred in the 6-h H2O2 treatment and that H2O2 mainly enhanced gene expression levels at the 6-h time point but reduced gene expression levels at the 24-h time point compared with the water treatment. In total, 4579 differentially expressed (2-fold change > 2) unigenes (DEGs), of which 78.3% were up-regulated and 21.7% were down-regulated; 3525 DEGs, of which 64.0% were up-regulated and 36.0% were down-regulated; and 7383 DEGs, of which 40.8% were up-regulated and 59.2% were down-regulated were selected in the 6-h, 24-h, and from 6- to 24-h treatments, respectively. The number of DEGs in the 6-h treatment was 29.9% higher than that in the 24-h treatment. The functions of the most highly regulated genes were associated with stress response, cell redox homeostasis and oxidative stress response, cell wall loosening and modification, metabolic processes, and transcription factors (TFs), as well as plant hormone signalling, including auxin, ethylene, cytokinin, gibberellin, and abscisic acid pathways. Notably, a large number of genes encoding for heat shock proteins (HSPs) and heat shock transcription factors (HSFs) were significantly up-regulated during H2O2 treatments. Furthermore, real-time quantitative PCR (qRT-PCR) results showed that, during H2O2 treatments, the expression levels of

  2. Pattern and intensity of human impact on coral reefs depend on depth along the reef profile and on the descriptor adopted

    Science.gov (United States)

    Nepote, Ettore; Bianchi, Carlo Nike; Chiantore, Mariachiara; Morri, Carla; Montefalcone, Monica

    2016-09-01

    Coral reefs are threatened by multiple global and local disturbances. The Maldives, already heavily hit by the 1998 mass bleaching event, are currently affected also by growing tourism and coastal development that may add to global impacts. Most of the studies investigating effects of local disturbances on coral reefs assessed the response of communities along a horizontal distance from the impact source. This study investigated the status of a Maldivian coral reef around an island where an international touristic airport has been recently (2009-2011) built, at different depths along the reef profile (5-20 m depth) and considering the change in the percentage of cover of five different non-taxonomic descriptors assessed through underwater visual surveys: hard corals, soft corals, other invertebrates, macroalgae and abiotic attributes. Eight reefs in areas not affected by any coastal development were used as controls and showed a reduction of hard coral cover and an increase of abiotic attributes (i.e. sand, rock, coral rubble) at the impacted reef. However, hard coral cover, the most widely used descriptor of coral reef health, was not sufficient on its own to detect subtle indirect effects that occurred down the reef profile. Selecting an array of descriptors and considering different depths, where corals may find a refuge from climate impacts, could guide the efforts of minimising local human pressures on coral reefs.

  3. Investigation of Arctic and Antarctic spatial and depth patterns of sea water in CTD profiles using chemometric data analysis

    DEFF Research Database (Denmark)

    Kotwa, Ewelina Katarzyna; Lacorte, Silvia; Duarte, Carlos

    2014-01-01

    In this paper we examine 2- and 3-way chemometric methods for analysis of Arctic and Antarctic water samples. Standard CTD (conductivity–temperature–depth) sensor devices were used during two oceanographic expeditions (July 2007 in the Arctic; February 2009 in the Antarctic) covering a total of 1......-chemical properties of the water samples; and 4) we confirm the ability to predict fluorescence values from physical measurements when the 3-way data structure is used in N-way PLS regression.......In this paper we examine 2- and 3-way chemometric methods for analysis of Arctic and Antarctic water samples. Standard CTD (conductivity–temperature–depth) sensor devices were used during two oceanographic expeditions (July 2007 in the Arctic; February 2009 in the Antarctic) covering a total of 174...... locations. The output from these devices can be arranged in a 3-way data structure (according to sea water depth, measured variables, and geographical location). We used and compared 2- and 3-way statistical tools including PCA, PARAFAC, PLS, and N-PLS for exploratory analysis, spatial patterns discovery...

  4. Time-resolved OCT-μPIV: a new microscopic PIV technique for noninvasive depth-resolved pulsatile flow profile acquisition

    Science.gov (United States)

    Chen, Chia-Yuan; Menon, Prahlad G.; Kowalski, William; Pekkan, Kerem

    2013-01-01

    In vivo acquisition of endothelial wall shear stress requires instantaneous depth-resolved whole-field pulsatile flow profile measurements in microcirculation. High-accuracy, quantitative and non- invasive velocimetry techniques are essential for emerging real-time mechano-genomic investigations. To address these research needs, a novel biological flow quantification technique, OCT-μPIV, was developed utilizing high-speed optical coherence tomography (OCT) integrated with microscopic Particle Image Velocimetry (μPIV). This technique offers the unique advantage of simultaneously acquiring blood flow profiles and vessel anatomy along arbitrarily oriented sagittal planes. The process is instantaneous and enables real-time 3D flow reconstruction without the need for computationally intensive image processing compared to state-of-the-art velocimetry techniques. To evaluate the line-scanning direction and speed, four sets of parametric synthetic OCT-μPIV data were generated using an in-house code. Based on this investigation, an in vitro experiment was designed at the fastest scan speed while preserving the region of interest providing the depth-resolved velocity profiles spanning across the width of a micro-fabricated channel. High-agreement with the analytical flow profiles was achieved for different flow rates and seed particle types and sizes. Finally, by employing blood cells as non-invasive seeding particles, in vivo embryonic vascular velocity profiles in multiple vessels were measured in the early chick embryo. The pulsatile flow frequency and peak velocity measurements were also acquired with OCT-μPIV, which agreed well with previous reported values. These results demonstrate the potential utility of this technique to conduct practical microfluidic and non-invasive in vivo studies for embryonic blood flows.

  5. Transcriptional Profiling of Hydrogen Production Metabolism of Rhodobacter capsulatus under Temperature Stress by Microarray Analysis

    Directory of Open Access Journals (Sweden)

    Muazzez Gürgan

    2015-06-01

    Full Text Available Biohydrogen is a clean and renewable form of hydrogen, which can be produced by photosynthetic bacteria in outdoor large-scale photobioreactors using sunlight. In this study, the transcriptional response of Rhodobacter capsulatus to cold (4 °C and heat (42 °C stress was studied using microarrays. Bacteria were grown in 30/2 acetate/glutamate medium at 30 °C for 48 h under continuous illumination. Then, cold and heat stresses were applied for two and six hours. Growth and hydrogen production were impaired under both stress conditions. Microarray chips for R. capsulatus were custom designed by Affymetrix (GeneChip®. TR_RCH2a520699F. The numbers of significantly changed genes were 328 and 293 out of 3685 genes under cold and heat stress, respectively. Our results indicate that temperature stress greatly affects the hydrogen production metabolisms of R. capsulatus. Specifically, the expression of genes that participate in nitrogen metabolism, photosynthesis and the electron transport system were induced by cold stress, while decreased by heat stress. Heat stress also resulted in down regulation of genes related to cell envelope, transporter and binding proteins. Transcriptome analysis and physiological results were consistent with each other. The results presented here may aid clarification of the genetic mechanisms for hydrogen production in purple non-sulfur (PNS bacteria under temperature stress.

  6. Understanding of CO{sub 2} interaction with thermally grown SiO{sub 2} on Si using IBA depth profiling techniques

    Energy Technology Data Exchange (ETDEWEB)

    Deokar, Geetanjali; D’Angelo, Marie; Briand, Emrick [INSP, UPMC, CNRS UMR 7588, 4 Place Jussieu, Paris F-75005 (France); Deville Cavellin, Catherine, E-mail: deville@univ-paris12.fr [INSP, UPMC, CNRS UMR 7588, 4 Place Jussieu, Paris F-75005 (France); Faculté des Sciences et Technologie UPEC, 61 Av., De Gaulle, Créteil F-94010 (France)

    2013-06-01

    Interactions between CO{sub 2} and SiO{sub 2} films thermally grown on Si have been studied using {sup 18}O and {sup 13}C as isotopic tracers associated with ion beam analysis (IBA) depth profiling techniques. From secondary ion mass spectrometry (SIMS) measurements no carbon from CO{sub 2} is detected in the silica while it is found in Si. These results suggest that CO{sub 2} diffuses through the silica. Exchanges of oxygen between CO{sub 2} and silica can be observed from {sup 18}O to {sup 16}O SIMS signals variation. The oxygen concentration depth profiles were determined quantitatively using the narrow resonance near 151 keV in the {sup 18}O(p,α){sup 15}N nuclear reaction (Narrow Resonance Profiling, NRP). We demonstrate that two distinct oxygen exchanges processes co-exist and we determine the diffusion coefficient of the CO{sub 2} molecule in the silica at 1100 °C.

  7. Confocal Raman Microspectroscopy: The Measurement of VX Depth Profiles in Hairless Guinea Pig Skin and the Evaluation of RSDL

    Science.gov (United States)

    2015-02-01

    through the skin and the extent of its axial distribution with time is critical to the development of effective therapeutics and decontamination...were aborted because of lost skin contact with the Raman window. While recording profile 26, the animal stopped breathing and was observed to be

  8. Into the Deep: Variability in Soil Microbial Communities and Carbon Turnover Along a Tropical Forest Soil Depth Profile

    Science.gov (United States)

    Pett-Ridge, J.; McFarlane, K. J.; Heckman, K. A.; Reed, S.; Wood, T. E.

    2015-12-01

    Tropical forest soils store more carbon (C) than any other terrestrial ecosystem and exchange vast amounts of CO2, water, and energy with the atmosphere. Much of this C is leached and stored within deeper soil layers, but we know exceedingly little about the fate of this C or the microbial communities that drive deep soil biogeochemistry. From the data that do exist, most organic matter (OM) in tropical soils appears associated with mineral particles, suggesting deep soils may provide greater C stabilization due to organo-metal co-precipitation and mineral-surface interactions. However, few studies have evaluated sub-surface soils in tropical ecosystems, the turnover times of deep soil C, and sensitivity of this C to global environmental change. To address this critical research need, we quantified C pools, microbial communities and soil radiocarbon turnover times in bulk soils and soil fractions [free light (unprotected), dense (mineral-associated)] from 0-140 cm in replicate soil pits in the Luquillo Experimental Forest, Puerto Rico. Unsurprisingly, we found soil C, nitrogen, and root and microbial biomass all declined exponentially with depth; total C stocks dropped from 5.5 % at the surface to temperate deciduous forests, these 14C values reflect far older soil C, and OM decomposition that highly favors free light C pools, even at depth. While previous work suggests these low C tropical subsoils contain small but metabolically active microbial communities at depths of ~100cm, these organisms appear highly OM limited, and preferentially degrade recent inputs. In the coming half century, tropical forests are predicted to see a 2 - 5 ° C temperature increase and substantial differences in rainfall amount and timing. The data described here represent baseline data for a site now undergoing a 4°C warming experiment; upcoming research will examine soil C storage and mean residence times during and post-warming to improve numerical models of ecosystem warming

  9. {sup 14}N depth profiles in Ti and Ti6Al4V nitrided by various methods, measured by nuclear reaction analysis

    Energy Technology Data Exchange (ETDEWEB)

    Vickridge, I.; Trompetter, B. [Institute of Geological and Nuclear Sciences Ltd., Lower Hutt (New Zealand); Brown, I. [Industrial Research Ltd, Lower Hutt (New Zealand)

    1993-12-31

    Titanium alloys have desirable mechanical properties for applications in many areas, but their surface properties, such as friction coefficient, hardness, and wear and corrosion resistance often need to be enhanced. This may be accomplished by forming a thin layer of titanium nitride on the surface, by such methods as thermal nitriding, Ion Beam Assisted Deposition (IBAD), sol-gel technology, or ion implantation. Ion Beam Analysis is assuming an increasing importance for characterising the composition of the outer few microns since it is the only technique that can rapidly yield quantitative concentration depth profiles of {sup 14}N with minimal disruption of the analysed region. 8 refs., 7 figs.

  10. Combined evaluation of grazing incidence X-ray fluorescence and X-ray reflectivity data for improved profiling of ultra-shallow depth distributions.

    Science.gov (United States)

    Ingerle, D; Meirer, F; Pepponi, G; Demenev, E; Giubertoni, D; Wobrauschek, P; Streli, C

    2014-09-01

    The continuous downscaling of the process size for semiconductor devices pushes the junction depths and consequentially the implantation depths to the top few nanometers of the Si substrate. This motivates the need for sensitive methods capable of analyzing dopant distribution, total dose and possible impurities. X-ray techniques utilizing the external reflection of X-rays are very surface sensitive, hence providing a non-destructive tool for process analysis and control. X-ray reflectometry (XRR) is an established technique for the characterization of single- and multi-layered thin film structures with layer thicknesses in the nanometer range. XRR spectra are acquired by varying the incident angle in the grazing incidence regime while measuring the specular reflected X-ray beam. The shape of the resulting angle-dependent curve is correlated to changes of the electron density in the sample, but does not provide direct information on the presence or distribution of chemical elements in the sample. Grazing Incidence XRF (GIXRF) measures the X-ray fluorescence induced by an X-ray beam incident under grazing angles. The resulting angle dependent intensity curves are correlated to the depth distribution and mass density of the elements in the sample. GIXRF provides information on contaminations, total implanted dose and to some extent on the depth of the dopant distribution, but is ambiguous with regard to the exact distribution function. Both techniques use similar measurement procedures and data evaluation strategies, i.e. optimization of a sample model by fitting measured and calculated angle curves. Moreover, the applied sample models can be derived from the same physical properties, like atomic scattering/form factors and elemental concentrations; a simultaneous analysis is therefore a straightforward approach. This combined analysis in turn reduces the uncertainties of the individual techniques, allowing a determination of dose and depth profile of the implanted

  11. Determination of the particulate extinction-coefficient profile and the column-integrated lidar ratios using the backscatter-coefficient and optical-depth profiles

    Science.gov (United States)

    Vladimir A Kovalev; Wei Min Hao; Cyle Wold

    2007-01-01

    A new method is considered that can be used for inverting data obtained from a combined elastic-inelastic lidar or a high spectral resolution lidar operating in a one-directional mode, or an elastic lidar operating in a multiangle mode. The particulate extinction coefficient is retrieved from the simultaneously measured profiles of the particulate backscatter...

  12. Analisis Perubahan Kurva Percentage Depth Dose (PDD) Dan Dose Profile Untuk Radiasi Foton 6MV Pada Fantom Thoraks

    OpenAIRE

    Prasetyo, Nur Dwi; Setiabudi, Wahyu; Anam, Choirul

    2012-01-01

    The study of thickness variation of the soft tissue in the wall of thoracic phantom to the shifting of Percentage Depht Dose (PDD) curve and Dose Profile have been done by using Monte Carlo Simulation. The linac head was designed using BEAMnrc software, whereas modeling of water and thoracic phantom using DOSXYZnrc software. The field size of beam radiation 10 x10 cm2 and the distance of source to phantom surface (SSD) 100 cm. The water phantom in cubic shape with a size 40x40x40 cm3. The t...

  13. Temperature profile and water depth data collected from USS CURTS using BT and XBT casts in the Japan Sea from 11 January 1989 to 17 January 1989 (NODC Accession 8900027)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS CURTS in the Japan Sea. Data were collected from 11 January 1989 to 17...

  14. Temperature profile and water depth data collected from USCGC GLACIER using BT and XBT casts in the NW / SW Pacific Ocean from 25 October 1986 to 31 January 1987 (NODC Accession 8700140)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts in the NW / SW Pacific Ocean from USCGC GLACIER. Data were collected from 25 October...

  15. Temperature profile and water depth data collected from USCGC GLACIER in the NW/SE Pacific Ocean and other seas from 31 January 1987 to 08 April 1987 (NODC Accession 8700183)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USCGC GLACIER in the Northwest/Southeast Pacific Ocean and other seas. Data...

  16. Temperature profile and water depth data from BT and XBT casts in the Atlantic Ocean from USCGC POLAR SEA from 14 December 1983 to 06 May 1984 (NODC Accession 8600108)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USCGC POLAR SEA in the Atlantic Ocean. Data were collected from 14 December...

  17. Temperature profile and water depth data collected from BT and XBT casts in the Northwest Atlantic Ocean from OCEANUS from 17 January 1981 to 05 May 1981 (NODC Accession 8600391)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth were collected using BT and XBT casts from the OCEANUS in the Northwest Atlantic Ocean. Data were collected from 17 January 1981...

  18. Temperature profile and water depth data collected from BAINBRIDGE using BT and XBT casts in the North Pacific Ocean from 03 July 1975 to 31 October 1977 (NODC Accession 8900230)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the BAINBRIDGE in the North Pacific Ocean and TOGA Area - Pacific Ocean. Data...

  19. National Coral Reef Monitoring Program: Shallow Water Conductivity-Temperature-Depth (CTD) Profiles for selected locations across the Hawaiian Archipelago from 2016-09-01 to 2016-09-27 (NCEI Accession 0161171)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Near-shore shallow water Conductivity-Temperature-Depth (CTD) surveys provided vertical profiles of temperature, salinity, and turbidity providing indications for...

  20. National Coral Reef Monitoring Program: Shallow Water Conductivity-Temperature-Depth (CTD) Profiles for selected locations across the Mariana Archipelago from 2014-03-24 to 2014-05-05 (NCEI Accession 0161168)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Near-shore shallow water Conductivity-Temperature-Depth (CTD) surveys provided vertical profiles of temperature, salinity, and turbidity providing indications for...

  1. Temperature profile and water depth data collected from USS ROBERT G. BRADLEY using BT and XBT casts in the NE/NW Atlantic Ocean and other seas from 03 May 1988 to 31 May 1988 (NODC Accession 8800213)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS ROBERT G. BRADLEY in the Northwest / Northeast Atlantic Ocean, Arabian...

  2. Temperature profile and water depth data collected from AUSTRALIA STAR and other platforms using XBT casts in the TOGA Area - Atlantic and Pacific Ocean from 05 October 1989 to 21 December 1992 (NODC Accession 9400035)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using XBT casts from the AUSTRALIA STAR and other platforms in the TOGA Area - Atlantic and Pacific Ocean,...

  3. Temperature profile and water depth collected from W.V. PRATT using BT and XBT casts in the NW Atlantic Ocean from 09 January 1987 to 30 January 1987 (NODC Accession 8700076)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT from the W.V. PRATT in the Northwest Atlantic Ocean and TOGA in the Atlantic Ocean. Data...

  4. Temperature profile and water depth data collected from USS MERRILL using BT and XBT casts in the Indian Ocean and other seas from 05 April 1988 to 11 April 1988 (NODC Accession 8800140)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS MERRILL in the Indian Ocean, Arabian Sea, and Gulf of Oman. Data were...

  5. Temperature profile and water depth data collected from USS BARBEY using BT and XBT casts in the TOGA Area - Pacific Ocean and other areas from 03 November 1988 to 01 December 1988 (NODC Accession 8800327)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS BARBEY in the TOGA Area - Pacific Ocean, Bay of Bengal, Indian Ocean,...

  6. Temperature profile and water depth data collected from USS BARBEY using BT and XBT casts in the Indian Ocean and other seas from 02 December 1988 to 28 December 1988 (NODC Accession 8900015)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS BARBEY in the Indian Ocean, Arabian Sea, Gulf of Oman, Gulf of Iran, and...

  7. Temperature profile and water depth data collected from USS MERRILL using BT and XBT casts in the Indian Ocean and other seas from 17 May 1988 to 01 June 1988 (NODC Accession 8800181)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS MERRILL in Arabian Sea, Indian Ocean, Gulf of Oman, Laccadive Sea, and...

  8. Temperature profile and water depth data collected from USS Merrill using BT and XBT casts in the Indian Ocean and other seas from 1988-03-01 to 1988-03-29 (NODC Accession 8800110)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS MERRILL in the Arabian Sea, Gulf of Oman, and Indian Ocean. Data were...

  9. Temperature profile and water depth data collected from USS HENRY B. WILSON using BT and XBT casts in the Indian Ocean and other seas from 22 October 1986 to 26 November 1986 (NODC Accession 8800183)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS HENRY B. WILSON in the Indian Ocean, Gulf of Oman, Gulf of Iran, and...

  10. Temperature profile and water depth data collected from USS CURTS using BT and XBT casts in the Northeast Pacific Ocean and other sea from 09 November 1988 to 20 November 1988 (NODC Accession 8800331)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS CURTS in the Northeast Pacific Ocean and Inland Sea. Data were collected...

  11. Temperature profile and water depth data collected from HMAS DARWIN and other platforms using BT and XBT casts in the North / South Pacific Ocean and Indian Ocean from 29 April 1985 to 12 April 1988 (NODC Accession 8800166)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the HMAS DARWIN and other platforms in the North / South Pacific Ocean and Indian...

  12. Temperature profile and water depth data collected from USS MOBILE BAY using BT and XBT casts in the NW Atlantic Ocean from 01 April 1987 to 07 April 1987 (NODC Accession 8700192)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS MOBILE BAY in the Northwest Atlantic Ocean and TOGA Area - Atlantic...

  13. Temperature profile and water depth collected from XIANG YANG HONG 05 in the South China Sea using BT and XBT casts from 16 November 1986 to 03 December 1986 (NODC Accession 8700009)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth were collected using BT and XBT casts from the XIANG YANG HONG 05 in the South China Sea. Data were collected from 16 November...

  14. Temperature profile and water depth data collected from BT and XBT casts in the Indian Ocean from ANRO AUSTRALIA and other platforms from 31 May 1983 to 02 November 1986 (NODC Accession 8700034)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the ANRO AUSTRALIA, FLINDERS, and other platforms in Indian Ocean. Data were...

  15. Temperature profile and water depth data collected from AMERICAN RESERVIST using BT and XBT casts in the North Pacific Ocean from 20 January 1974 to 29 September 1977 (NODC Accession 8900287)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the AMERICAN RESERVIST in the North Pacific Ocean and TOGA Area - Pacific Ocean....

  16. Temperature profile and water depth data collected from USCGC BOUTWELL using BT and XBT casts in the NW Pacific Ocean from 03 February 1987 to 17 February 1987 (NODC Accession 8700161)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT from the USCGC BOUTWELL in the Northwest Pacific Ocean. Data were collected from 03 February...

  17. Temperature profile and water depth data collected from USS MERRILL using BT and XBT casts in the Northwest Pacific Ocean from 11 August 1992 to 27 August 1992 (NODC Accession 9200253)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS MERRILL in the Northwest Pacific Ocean. Data were collected from 11...

  18. Temperature profile and water depth data collected from USS COCHRANE using BT and XBT casts in the East China sea and other seas from 07 March 1987 to 19 March 1987 (NODC Accession 8700263)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS COCHRANE in the South China sea, East China Sea, and Philippine Sea. Data...

  19. Temperature profile and water depth data collected from USS CURTS using BT and XBT casts in the NE/NW Pacific Ocean from 02 June 1988 to 19 June 1988 (NODC Accession 8800215)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS CURTS in the Northeast / Northwest Pacific Ocean and TOGA Area - Pacific...

  20. Temperature profile and water depth data collected from USS CURTS using BT and XBT casts in the Northwest Pacific Ocean from 21 March 1988 to 22 March 1988 (NODC Accession 8800144)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS CURTS in the Northwest Pacific Ocean. Data were collected from 21 March...

  1. Temperature profile and water depth data collected from USS CURTS using BT and XBT casts in the Indian Ocean and other seas from 01 December 1987 to 21 December 1987 (NODC Accession 8800028)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS CURTS in the Indian Ocean and other seas. Data were collected from 01...

  2. Temperature profile and water depth data collected from USS COCHRANE using BT and XBT casts in the Indian Ocean and other seas from 01 August 1987 to 27 September 1987 (NODC Accession 8700394)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS COCHRANE in the Indian Ocean, Arabian Sea, Laccadive Sea, and Philippine...

  3. Temperature profile and water depth data collected from USS JOUETT using BT and XBT casts in the Northwest Pacific Ocean from 14 July 1987 to 16 July 1987 (NODC Accession 8700264)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS JOUETT in the Northwest Pacific Ocean. Data were collected from 14 July...

  4. Temperature profile and water depth data collected from USS MERRILL using BT and XBT casts in the NE/NW Pacific Ocean and other seas from 17 June 1988 to 27 June 1988 (NODC Accession 8800217)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS MERRILL in the Northeast / Northwest Pacific Ocean, Japan Sea and Inland...

  5. Temperature profile and water depth data collected from USS ROBERT G. BRADLEY using BT and XBT casts in the Northwest Atlantic Ocean from 15 December 1988 to 28 February 1989 (NODC Accession 8900110)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS ROBERT G. BRADLEY in the Northwest Atlantic Ocean and TOGA Area -...

  6. Temperature profile and water depth data collected from USCGC HAMILTON using BT and XBT casts in the Northwest Pacific Ocean and Bering Sea from 23 October 1991 to 09 May 1992 (NODC Accession 9200241)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USCGC HAMILTON in the Northeast / Northwest Pacific Ocean and Bering Sea....

  7. Temperature profile and water depth data collected from USS HARRY E. YARNELL using BT and XBT casts in the Bay of Biscay and other seas from 30 June 1992 to 17 September 1992 (NODC Accession 9200283)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS HARRY E. YARNELL in the Bay of Biscay, English Channel, Northeast...

  8. Temperature profile and water depth data collected from SAXON STAR and other platforms in a World wide distribution from 09 March 1983 to 12 November 1986 (NODC Accession 8700035)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT from the SAXON STAR and other platforms in a World wide distribution. Data were collected...

  9. Temperature profile and water depth data collected from USS MOBILE BAY using BT and XBT casts in the NW Atlantic Ocean from 15 May 1987 to 27 May 19876 (NODC Accession 8700223)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS MOBILE BAY in the Northwest Atlantic Ocean. Data were collected from 15...

  10. Temperature profile and water depth data collected from USS BARBEY using BT and XBT casts in the Indian ocean and other seas from 07 January 1989 to 31 January 1989 (NODC Accession 8900034)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS BARBEY in the Indian Ocean, South China Sea, Burma Sea, and Malacca of...

  11. Temperature profile and water depth data collected from USS BARBEY using BT and XBT casts in the TOA Area - Pacific Ocean and other seas from 02 October 1988 to 30 October 1988 (NODC Accession 8800335)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS BARBEY in the TOGA Area - Pacific Ocean, Inland Sea, South China Sea,...

  12. Temperature profile and water depth data collected from USS HAYLER using BT and XBT casts in the Arabian Sea and other seas from 31 October 1984 to 22 October 1985 (NODC Accession 9200289)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS HAYLER in the Arabian Sea and other seas. Data were collected from 31...

  13. Temperature profile and water depth data collected from SAMUEL B. ROBERTS in the NW Atlantic (limit-40 W) from 22 September 1986 to 07 October 1986 (NODC Accession 8600353)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT from the USS SAMUEL B. ROBERTS in the Northwest Atlantic Ocean. Data were collected from 22...

  14. Temperature profile and water depth collected from EDGAR M. QUEENY from BT and XBT casts in the Gulf of Mexico from 13 December 1985 to 22 December 1985 (NODC Accession 8600318)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the EDGAR M. QUEENY in the Gulf of Mexico. Data were collected from 13 December...

  15. Difference between bulk and thin film densities of metal oxide and fluoride films studied by NRA depth profiling techniques

    CERN Document Server

    Coban, A; Durrani, S A

    2002-01-01

    Nuclear reaction analysis techniques have been used to study the difference between bulk and thin film densities of different dielectric (WO sub 3 , MgF sub 2 , NdF sub 3 , LaF sub 3 and ThF sub 4) thin films. Thicknesses of the films were measured by optical methods. The sup 1 sup 8 O(p,alpha) sup 1 sup 5 N reaction was used at 730 keV to profile WO sub 3 prepared with different thicknesses on a tantalum backing by thermal evaporation of natural WO sub 3. We have also successfully tested the sup 1 sup 8 O(p,alpha) sup 1 sup 5 N reaction at the 629 keV (GAMMA=2.1 keV) resonance for the same purpose. Excitation function measurement of the reaction was performed around the resonant energy at a detection angle of 150 deg. . In order to obtain the oxygen profiles of the thin films non-resonant part of the excitation function was deconvoluted using the known cross-section data of the reaction. Also, we studied different films of MgF sub 2 , NdF sub 3 , LaF sub 3 and ThF sub 4 using the 483.85 keV resonance in the ...

  16. Two Photon Absorption Laser Induced Fluorescence for Neutral Hydrogen Profile Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Scime, Earl E. [West Virginia Univ., Morgantown, WV (United States)

    2016-09-23

    The magnitude and spatial dependence of neutral density in magnetic confinement fusion experiments is a key physical parameter, particularly in the plasma edge. Modeling codes require precise measurements of the neutral density to calculate charge-exchange power losses and drag forces on rotating plasmas. However, direct measurements of the neutral density are problematic. In this work, we proposed to construct a laser-based diagnostic capable of providing spatially resolved measurements of the neutral density in the edge of plasma in the DIII-D tokamak. The diagnostic concept is based on two-photon absorption laser induced fluorescence (TALIF). By injecting two beams of 205 nm light (co or counter propagating), ground state hydrogen (or deuterium or tritium) can be excited from the n = 1 level to the n = 3 level at the location where the two beams intersect. Individually, the beams experience no absorption, and therefore have no difficulty penetrating even dense plasmas. After excitation, a fraction of the hydrogen atoms decay from the n = 3 level to the n = 2 level and emit photons at 656 nm (the Hα line). Calculations based on the results of previous TALIF experiments in magnetic fusion devices indicated that a laser pulse energy of approximately 3 mJ delivered in 5 ns would provide sufficient signal-to-noise for detection of the fluorescence. In collaboration with the DIII-D engineering staff and experts in plasma edge diagnostics for DIII-D from Oak Ridge National Laboratory (ORNL), WVU researchers designed a TALIF system capable of providing spatially resolved measurements of neutral deuterium densities in the DIII-D edge plasma. The laser systems were specified, purchased, and assembled at WVU. The TALIF system was tested on a low-power hydrogen discharge at WVU and the plan was to move the instrument to DIII-D for installation in collaboration with ORNL researchers. After budget cuts at DIII-D, the DIII-D facility declined to support

  17. Combination of multistep IMAC enrichment with high-pH reverse phase separation for in-depth phosphoproteomic profiling.

    Science.gov (United States)

    Yue, Xiao-Shan; Hummon, Amanda B

    2013-09-06

    Typical mass spectrometric phosphoproteome studies are complicated by the need for large amounts of starting material and extensive sample preparation to ensure sufficient phosphopeptide identifications. In this paper, we present a novel strategy to perform optimized multistep IMAC enrichment from whole cell lysates followed by high-pH reverse phase fractionation (multi-IMAC-HLB; HLB means hydrophilic-lipophilic-balanced reversed-phase cartridge). The peptide-to-IMAC ratio was optimized to maximize IMAC performance, while multistep IMAC enrichment enabled improved phosphopeptide acquisition. The addition of the HLB step further fractionates the IMAC enriched phosphopeptides while desalting the samples, which dramatically reduces the sample manipulation time and sample loss compared to other popular strategies. We compared the phosphopeptide identification results of the multi-IMAC-HLB method with 3 mg of starting material to the well-established SCX-IMAC method with 15 mg of starting material. We identified 8969 unique phosphopeptides with the multi-IMAC-HLB method, compared to 5519 unique phosphopeptides identified with the SCX-IMAC method, an increase of 62.5%. The increase in the numbers of identified phosphopeptides is due to the increase in the ratio of identified phosphopeptides out of all detected peptides, 70.5% with multi-IMAC-HLB method compared to 32.3% with the SCX-IMAC method. Multi-IMAC-HLB is a robust and efficient method for in-depth phosphoproteomic research.

  18. Improved stratigraphic dating at a low accumulation Alpine ice core through laser ablation trace element profiling at sub-mm depth resolution

    Science.gov (United States)

    Bohleber, Pascal; Spaulding, Nicole; Mayewski, Paul; Sneed, Sharon; Handley, Mike; Erhardt, Tobias; Wagenbach, Dietmar

    2015-04-01

    The small scale Colle Gnifetti glacier saddle (4450 m asl, Monte Rosa region) is the only ice core drilling site in the European Alps with a net accumulation low enough to offer multi-millennia climate records. However, a robust interpretation of such long term records (i.e. mineral dust, stable water isotopes) at the Colle Gnifetti (CG) multi core array is strongly challenged by depositional noise associated with a highly irregular annual layer stratigraphy. In combination with a relatively large vertical strain rate and rapid layer thinning, annual layer counting gets increasingly ambiguous as of approximately 100 years. In addition, this prevents clear attribution of likely volcanic horizons to historical eruption dates. To improve stratigraphic dating under such intricate conditions, we deployed laser ablation (LA) ICP-MS at sub-mm sample resolution. We present here the first LA impurity profiles from a new Colle Gnifetti ice core drilled 73 m to bedrock in 2013 at a site where the net snow accumulation is around 20 cm w.e. per year. We contrast the LA signal variability (including Ca, Fe, Na) to continuous flow analyses (CFA) records at cm-resolution (Ca, Na, melt water conductivity, micro- particle) recorded over the whole core length. Of special concern are the lower 28 m to bedrock, which have been continuously profiled in LA Ca, thus offering the direct comparison of Ca-signals between CFA and LA. By this means, we first validate at upper depths LA based annual layer identification through agreement with CFA based counting efforts before demonstrating the LA based counting still works at depths where CFA derived annual layers become spurious since embedded in strong, multi-year cycles. Finally, LA ice core profiling of our CG core has potential for not only dating improvement but also reveals benefits in resolving highly thinned basal ice sections including accounting for micro-structural features such as grain boundaries.

  19. In depth fusion flame spreading with a deuterium—tritium plane fuel density profile for plasma block ignition

    Science.gov (United States)

    Malekynia, B.; S. Razavipour, S.

    2012-12-01

    Solid-state fuel ignition was given by Chu and Bobin according to the hydrodynamic theory at x = 0 qualitatively. A high threshold energy flux density, i.e., E* = 4.3 × 1012 J/m2, has been reached. Recently, fast ignition by employing clean petawatt—picosecond laser pulses was performed. The anomalous phenomena were observed to be based on suppression of prepulses. The accelerated plasma block was used to ignite deuterium—tritium fuel at solid-state density. The detailed analysis of the thermonuclear wave propagation was investigated. Also the fusion conditions at x ≠ 0 layers were clarified by exactly solving hydrodynamic equations for plasma block ignition. In this paper, the applied physical mechanisms are determined for nonlinear force laser driven plasma blocks, thermonuclear reaction, heat transfer, electron—ion equilibration, stopping power of alpha particles, bremsstrahlung, expansion, density dependence, and fluid dynamics. New ignition conditions may be obtained by using temperature equations, including the density profile that is obtained by the continuity equation and expansion velocity. The density is only a function of x and independent of time. The ignition energy flux density, E*t, for the x ≠ 0 layers is 1.95 × 1012 J/m2. Thus threshold ignition energy in comparison with that at x = 0 layers would be reduced to less than 50 percent.

  20. Production of 21Ne in depth-profiled olivine from a 54 Ma basalt sequence, Eastern Highlands (37° S), Australia

    Science.gov (United States)

    Matchan, Erin L.; Honda, Masahiko; Barrows, Timothy T.; Phillips, David; Chivas, Allan R.; Fifield, L. Keith; Fabel, Derek

    2018-01-01

    In this study we investigate the cosmogenic neon component in olivine samples from a vertical profile in order to quantify muogenic 21Ne production in this mineral. Samples were collected from an 11 m thick Eocene basalt profile in the Eastern Highlands of southeastern Australia. An eruption age of 54.15 ± 0.36 Ma (2σ) was determined from 40Ar/39Ar step-heating experiments (n = 6) on three whole-rock samples. A 36Cl profile on the section indicated an apparent steady state erosion rate of 4.7 ± 0.5 m Ma-1. The eruption age was used to calculate in situ produced radiogenic 4He and nucleogenic 3He and 21Ne concentrations in olivine. Olivine mineral separates (n = 4), extracted from the upper two metres of the studied profile, reveal cosmogenic 21Ne concentrations that attenuate exponentially with depth. However, olivine (Fo68) extracted from below 2 m does not contain discernible 21Ne aside from magmatic and nucleogenic components, with the exception of one sample that apparently contained equal proportions of nucleogenic and muogenic neon. Modelling results suggest a muogenic neon sea-level high-latitude production rate of 0.02 ± 0.04 to 0.9 ± 1.3 atoms g-1 a-1 (1σ), or Earth's surface. These data support a key implicit assumption in the literature that accumulation of muogenic 21Ne in olivine in surface samples is likely to be negligible/minimal compared to spallogenic 21Ne.

  1. Competing quantum effects in the free energy profiles and diffusion rates of hydrogen and deuterium molecules through clathrate hydrates.

    Science.gov (United States)

    Cendagorta, Joseph R; Powers, Anna; Hele, Timothy J H; Marsalek, Ondrej; Bačić, Zlatko; Tuckerman, Mark E

    2016-11-30

    Clathrate hydrates hold considerable promise as safe and economical materials for hydrogen storage. Here we present a quantum mechanical study of H2 and D2 diffusion through a hexagonal face shared by two large cages of clathrate hydrates over a wide range of temperatures. Path integral molecular dynamics simulations are used to compute the free-energy profiles for the diffusion of H2 and D2 as a function of temperature. Ring polymer molecular dynamics rate theory, incorporating both exact quantum statistics and approximate quantum dynamical effects, is utilized in the calculations of the H2 and D2 diffusion rates in a broad temperature interval. We find that the shape of the quantum free-energy profiles and their height relative to the classical free energy barriers at a given temperature, as well as the rate of diffusion, are strongly affected by competing quantum effects: above 25 K, zero-point energy (ZPE) perpendicular to the reaction path for diffusion between cavities decreases the quantum rate compared to the classical rate, whereas at lower temperatures tunneling outcompetes the ZPE and as a result the quantum rate is greater than the classical rate.

  2. Competing quantum effects in the free energy profiles and diffusion rates of hydrogen and deuterium molecules through clathrate hydrates

    CERN Document Server

    Cendagorta, Joseph R; Hele, Timothy J H; Marsalek, Ondrej; Bačić, Zlatko; Tuckerman, Mark E

    2016-01-01

    Clathrate hydrates hold considerable promise as safe and economical materials for hydrogen storage. Here we present a quantum mechanical study of H$_2$ and D$_2$ diffusion through a hexagonal face shared by two large cages of clathrate hydrates over a wide range of temperatures. Path integral molecular dynamics simulations are used to compute the free-energy profiles for the diffusion of H$_2$ and D$_2$ as a function of temperature. Ring polymer molecular dynamics rate theory, incorporating both exact quantum statistics and approximate quantum dynamical effects, is utilized in the calculations of the H$_2$ and D$_2$ diffusion rates in a broad temperature interval. We find that the shape of the quantum free-energy profiles and their height relative to the classical free energy barriers at a given temperature, as well as the rate of diffusion, are profoundly affected by competing quantum effects: above 25 K, zero-point energy (ZPE) perpendicular to the reaction path for diffusion between cavities decreases the ...

  3. Small-Angle Fibre Diffraction Studies of Cornela Matrix Structure: A Depth-Profiled Investigation of the Human Eye-Bank Cornea

    Energy Technology Data Exchange (ETDEWEB)

    Quantock,A.; Boote, C.; Young, R.; Hayes, S.; Tanioka, H.; Kawasaki, S.; Ohta, N.; Lida, T.; Yagi, N.; et al.

    2007-01-01

    In the cornea of the eye light transmission is facilitated by the regular arrangement and uniform diameter of collagen fibrils that constitute the bulk of the extracellular corneal matrix. Matrix architecture, in turn, is believed to be governed by interactions between collagen fibrils and proteoglycan molecules modified with sulfated glycosaminoglycan side chains. Here, we outline the contribution made by small-angle X-ray scattering studies of the cornea in understanding the role of sulfated glycosaminoglycans in the control of collagen architecture in cornea, and present new depth-profiled microbeam data from swollen human eye-bank corneas that indicate no significant change in collagen fibril diameter throughout the tissue, but a lower collagen interfibrillar spacing in the anterior-most stromal regions compared with the ultrastructure of the deeper cornea.

  4. ChiMS: Open-source instrument control software platform on LabVIEW for imaging/depth profiling mass spectrometers.

    Science.gov (United States)

    Cui, Yang; Hanley, Luke

    2015-06-01

    ChiMS is an open-source data acquisition and control software program written within LabVIEW for high speed imaging and depth profiling mass spectrometers. ChiMS can also transfer large datasets from a digitizer to computer memory at high repetition rate, save data to hard disk at high throughput, and perform high speed data processing. The data acquisition mode generally simulates a digital oscilloscope, but with peripheral devices integrated for control as well as advanced data sorting and processing capabilities. Customized user-designed experiments can be easily written based on several included templates. ChiMS is additionally well suited to non-laser based mass spectrometers imaging and various other experiments in laser physics, physical chemistry, and surface science.

  5. Depth of maximum of air-shower profiles at the Pierre Auger Observatory. I. Measurements at energies above 1 017.8 eV

    Science.gov (United States)

    Aab, A.; Abreu, P.; Aglietta, M.; Ahn, E. J.; Al Samarai, I.; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Aramo, C.; Aranda, V. M.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Awal, N.; Badescu, A. M.; Barber, K. B.; Bäuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertaina, M. E.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blaess, S.; Blanco, M.; Bleve, C.; Blümer, H.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Bridgeman, A.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Buitink, S.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Candusso, M.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Chavez, A. G.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Coleman, A.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cooper, M. J.; Cordier, A.; Coutu, S.; Covault, C. E.; Cronin, J.; Curutiu, A.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; de Jong, S. J.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Di Matteo, A.; Diaz, J. C.; Díaz Castro, M. L.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dorofeev, A.; Dorosti Hasankiadeh, Q.; Dova, M. T.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fernandes, M.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipčič, A.; Fox, B. D.; Fratu, O.; Fröhlich, U.; Fuchs, B.; Fujii, T.; Gaior, R.; García, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Gascon Bravo, A.; Gate, F.; Gemmeke, H.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Glaser, C.; Glass, H.; Gómez Berisso, M.; Gómez Vitale, P. F.; Gonçalves, P.; Gonzalez, J. G.; González, N.; Gookin, B.; Gordon, J.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grebe, S.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guarino, F.; Guedes, G. P.; Hampel, M. R.; Hansen, P.; Harari, D.; Harrison, T. A.; Hartmann, S.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holt, E.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huber, D.; Huege, T.; Insolia, A.; Isar, P. G.; Jandt, I.; Jansen, S.; Jarne, C.; Josebachuili, M.; Kääpä, A.; Kambeitz, O.; Kampert, K. H.; Kasper, P.; Katkov, I.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Krömer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kunka, N.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Le Coz, S.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Lopez Agüera, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Malacari, M.; Maldera, S.; Mallamaci, M.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Mariş, I. C.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martínez Bravo, O.; Martraire, D.; Masías Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Meissner, R.; Melissas, M.; Melo, D.; Menshikov, A.; Messina, S.; Meyhandan, R.; Mićanović, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morello, C.; Mostafá, M.; Moura, C. A.; Muller, M. A.; Müller, G.; Müller, S.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nguyen, P.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nožka, L.; Ochilo, L.; Olinto, A.; Oliveira, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Papenbreer, P.; Parente, G.; Parra, A.; Paul, T.; Pech, M.; PÈ©kala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Petermann, E.; Peters, C.; Petrera, S.; Petrov, Y.; Phuntsok, J.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porcelli, A.; Porowski, C.; Prado, R. R.; Privitera, P.; Prouza, M.; Purrello, V.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rizi, V.; Rodrigues de Carvalho, W.; Rodriguez Cabo, I.; Rodriguez Fernandez, G.; Rodriguez Rojo, J.; Rodríguez-Frías, M. D.; Rogozin, D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Roulet, E.; Rovero, A. C.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Saleh, A.; Salesa Greus, F.; Salina, G.; Sánchez, F.; Sanchez-Lucas, P.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarmento, R.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, D.; Scholten, O.; Schoorlemmer, H.; Schovánek, P.; Schulz, A.; Schulz, J.; Schumacher, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Sima, O.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Squartini, R.; Srivastava, Y. N.; Stanič, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Taborda, O. A.; Tapia, A.; Tartare, M.; Tepe, A.; Theodoro, V. M.; Timmermans, C.; Todero Peixoto, C. J.; Toma, G.; Tomankova, L.; Tomé, B.; Tonachini, A.; Torralba Elipe, G.; Torres Machado, D.; Travnicek, P.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van Bodegom, P.; van den Berg, A. M.; van Velzen, S.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Varner, G.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Verzi, V.; Vicha, J.; Videla, M.; Villaseñor, L.; Vlcek, B.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Widom, A.; Wiencke, L.; Wilczyńska, B.; Wilczyński, H.; Will, M.; Williams, C.; Winchen, T.; Wittkowski, D.; Wundheiler, B.; Wykes, S.; Yamamoto, T.; Yapici, T.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Zhou, J.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.; Zuccarello, F.; Pierre Auger Collaboration

    2014-12-01

    We report a study of the distributions of the depth of maximum, Xmax, of extensive air-shower profiles with energies above 1 017.8 eV as observed with the fluorescence telescopes of the Pierre Auger Observatory. The analysis method for selecting a data sample with minimal sampling bias is described in detail as well as the experimental cross-checks and systematic uncertainties. Furthermore, we discuss the detector acceptance and the resolution of the Xmax measurement and provide parametrizations thereof as a function of energy. The energy dependence of the mean and standard deviation of the Xmax distributions are compared to air-shower simulations for different nuclear primaries and interpreted in terms of the mean and variance of the logarithmic mass distribution at the top of the atmosphere.

  6. ChiMS: Open-source instrument control software platform on LabVIEW for imaging/depth profiling mass spectrometers

    Science.gov (United States)

    Cui, Yang; Hanley, Luke

    2015-01-01

    ChiMS is an open-source data acquisition and control software program written within LabVIEW for high speed imaging and depth profiling mass spectrometers. ChiMS can also transfer large datasets from a digitizer to computer memory at high repetition rate, save data to hard disk at high throughput, and perform high speed data processing. The data acquisition mode generally simulates a digital oscilloscope, but with peripheral devices integrated for control as well as advanced data sorting and processing capabilities. Customized user-designed experiments can be easily written based on several included templates. ChiMS is additionally well suited to non-laser based mass spectrometers imaging and various other experiments in laser physics, physical chemistry, and surface science. PMID:26133872

  7. SIMS depth profiling of boron ultra shallow junctions using oblique O{sub 2} {sup +} beams down to 150 eV

    Energy Technology Data Exchange (ETDEWEB)

    Juhel, M. [STMicroelectronics, 850 rue Jean Monnet, Crolles 38926 (France)]. E-mail: marc.juhel@st.com; Laugier, F. [CEA-DRT-LETI CEA/GRE 17, rue des martyrs 38054 Grenoble Cedex (France); Delille, D. [Philips Semiconductors, 860 rue Jean Monnet, Crolles 38920 (France); Wyon, C. [CEA-DRT-LETI CEA/GRE 17, rue des martyrs 38054 Grenoble Cedex (France); Kwakman, L.F.Tz. [Philips Semiconductors, 860 rue Jean Monnet, Crolles 38920 (France); Hopstaken, M. [Philips Semiconductors, 860 rue Jean Monnet, Crolles 38920 (France)

    2006-07-30

    An epitaxial Si grown multi-layer stack consisting of boron delta-doped layers separated by 6.4 nm thick undoped films has been profiled using a Cameca IMS Wf magnetic SIMS. Using low energy oblique O{sub 2} {sup +} beam, the boron depth resolution is improved from 1.66 nm/decade at 500 eV down to 0.83 nm/decade at 150 eV. At very low impact energy O{sub 2} {sup +} bombardment induces a near full oxidation of silicon and oxygen flooding is then no more needed in the analytical chamber to get a smooth sputtering of silicon at 45 deg. incidence angle.

  8. Argon Cluster Sputtering Source for ToF-SIMS Depth Profiling of Insulating Materials: High Sputter Rate and Accurate Interfacial Information

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhaoying; Liu, Bingwen; Zhao, Evan; Jin, Ke; Du, Yingge; Neeway, James J.; Ryan, Joseph V.; Hu, Dehong; Zhang, Hongliang; Hong, Mina; Le Guernic, Solenne; Thevuthasan, Suntharampillai; Wang, Fuyi; Zhu, Zihua

    2015-08-01

    For the first time, the use of an argon cluster ion sputtering source has been demonstrated to perform superiorly relative to traditional oxygen and cesium ion sputtering sources for ToF-SIMS depth profiling of insulating materials. The superior performance has been attributed to effective alleviation of surface charging. A simulated nuclear waste glass, SON68, and layered hole-perovskite oxide thin films were selected as model systems due to their fundamental and practical significance. Our study shows that if the size of analysis areas is same, the highest sputter rate of argon cluster sputtering can be 2-3 times faster than the highest sputter rates of oxygen or cesium sputtering. More importantly, high quality data and high sputter rates can be achieved simultaneously for argon cluster sputtering while this is not the case for cesium and oxygen sputtering. Therefore, for deep depth profiling of insulating samples, the measurement efficiency of argon cluster sputtering can be about 6-15 times better than traditional cesium and oxygen sputtering. Moreover, for a SrTiO3/SrCrO3 bi-layer thin film on a SrTiO3 substrate, the true 18O/16O isotopic distribution at the interface is better revealed when using the argon cluster sputtering source. Therefore, the implementation of an argon cluster sputtering source can significantly improve the measurement efficiency of insulating materials, and thus can expand the application of ToF-SIMS to the study of glass corrosion, perovskite oxide thin films, and many other potential systems.

  9. Analysis of small field percent depth dose and profiles: Comparison of measurements with various detectors and effects of detector orientation with different jaw settings

    Directory of Open Access Journals (Sweden)

    Henry Finlay Godson

    2016-01-01

    Full Text Available The advent of modern technologies in radiotherapy poses an increased challenge in the determination of dosimetric parameters of small fields that exhibit a high degree of uncertainty. Percent depth dose and beam profiles were acquired using different detectors in two different orientations. The parameters such as relative surface dose (DS, depth of dose maximum (Dmax, percentage dose at 10 cm (D10, penumbral width, flatness, and symmetry were evaluated with different detectors. The dosimetric data were acquired for fields defined by jaws alone, multileaf collimator (MLC alone, and by MLC while the jaws were positioned at 0, 0.25, 0.5, and 1.0 cm away from MLC leaf-end using a Varian linear accelerator with 6 MV photon beam. The accuracy in the measurement of dosimetric parameters with various detectors for three different field definitions was evaluated. The relative DS(38.1% with photon field diode in parallel orientation was higher than electron field diode (EFD (27.9% values for 1 cm ×1 cm field. An overestimation of 5.7% and 8.6% in D10depth were observed for 1 cm ×1 cm field with RK ion chamber in parallel and perpendicular orientation, respectively, for the fields defined by MLC while jaw positioned at the edge of the field when compared to EFD values in parallel orientation. For this field definition, the in-plane penumbral widths obtained with ion chamber in parallel and perpendicular orientation were 3.9 mm, 5.6 mm for 1 cm ×1 cm field, respectively. Among all detectors used in the study, the unshielded diodes were found to be an appropriate choice of detector for the measurement of beam parameters in small fields.

  10. Depth-profile analysis of thermoelectric layers on Si wafers by pulsed r.f. glow discharge time-of-flight mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Reinsberg, K.-G. [Institute for Inorganic and Applied Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, D-20146 Hamburg (Germany); Schumacher, C. [Institute for Applied Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg (Germany); Tempez, A. [HORIBA Jobin Yvon, 16-18 rue du Canal, F-91160 Longjumeau (France); Nielsch, K. [Institute for Applied Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg (Germany); Broekaert, J.A.C., E-mail: jose.broekaert@chemie.uni-hamburg.de [Institute for Inorganic and Applied Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, D-20146 Hamburg (Germany)

    2012-10-15

    In this work the depth-profile analysis of thermoelectric layers deposited on Au and Cr covered Si wafers with the aid of pulsed radiofrequency glow discharge time-of-flight mass spectrometry (pulsed RF-GD-TOFMS also called plasma profiling TOFMS (PP-TOFMS Trade-Mark-Sign )) is described. For thermoelectric materials the depth resolutions obtained with both PP-TOFMS and secondary ion mass spectrometry (SIMS) are shown to be well comparable and in the order of the roughness of the corresponding layers (between 20 and 3700 nm). With both methods a direct solid analysis without any preparation steps is possible. In addition, the analysis of the samples with PP-TOFMS proved to be faster by a factor of 26 compared to SIMS, as sputtering rates were found to be 80 nm s{sup -1} and 3 nm s{sup -1}, respectively. For the analyzed samples the results of PP-TOFMS and SIMS show that a homogeneous deposition was obtained. Quantitative results for all samples could also be obtained directly by PP-TOFMS when the stoichiometry of one sample was determined beforehand for instance by inductively coupled plasma optical emission spectrometry (ICP-OES) and scanning electron microscopy energy dispersive X-ray fluorescence spectrometry (SEM-EDX). For Bi{sub 2}Te{sub 3} the standard deviation for the main component concentrations within one sample then is found to be between 1.1% and 1.9% and it is 3.6% from sample to sample. For Sb{sub 2}Te{sub 3} the values within one sample are from 1.7% to 4.2% and from sample to sample 5.3%, respectively. - Highlights: Black-Right-Pointing-Pointer Depth resolution in sub micrometer size by glow discharge mass spectrometry. Black-Right-Pointing-Pointer Bi and Sb telluride layers composition with GD-TOF-MS, ICP-OES and SEM-EDX agree. Black-Right-Pointing-Pointer Homogeneities of layers measured with GD-TOF-MS and SIMS agree.

  11. Hydrogen depth distribution and fatigue properties of TiAl6V4 with implanted nitrogen; Wasserstoff-Tiefenverteilung und Ermuedungseigenschaften von Stickstoff-implantiertem TiAl6V4

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, H. [Technische Univ. Darmstadt (Germany). Fachbereich Materialwissenschaft; Rueck, D.M. [Gesellschaft fuer Schwerionenforschung mbH (GSI), Darmstadt (Germany). Abt. fuer Materialforschung; Soltani-Farshi, M.; Baumann, H. [Frankfurt Univ. (Germany). Inst. fuer Kernphysik

    1998-12-31

    Depth distributions and cracking initiation were analysed in TiAl6V4 with implanted nitrogen by means of high-energy backscattering spectroscopy, nuclear reaction analysis and fatigue tests under rotary bending loads. The hydrogen content in the substrate is approx. 0.4 at.%. The hydrogen content in the materials layer with implanted nitrogen is up to 2.6 at%. The highest hydrogen concentration was found in material consisting of titanium nitride (TiN) and {alpha}-titanium. In areas with high nitrogen accumulation, where a consistent TiN layer is formed, the hydrogen content is lower than 1.5 at.%. Nitrogen ion implantation was not found to significantly reduce the fatigue strength of the specimens tested under rotary bending loads, although fatigue-induced cracking primarily occurs in specimen zones where the maximum concentrations of hydrogen and nitrogen are close to the surface. (orig./CB) [Deutsch] Tiefenverteilungen und die Rissbildung von Stickstoff-implantiertem TiAl6V4 wurden mittels Hochenergie-Rueckstreu-Spektroskopie, Kernreaktionsanalyse und Umlaufbiegetests untersucht. Der Wasserstoffgehalt im Substrat betraegt etwa 0,4 at.%. In der Stickstoff-implantierten Schicht wird eine Wasserstoffakkumulation bis zu 2,6 at% beobachtet. Die hoechste Wasserstoffkonzentration tritt auf, wenn eine Mischung aus Titannitrid (TiN) und mit Stickstoff angereichertem {alpha}-Titan vorliegt. In Bereichen hoher Stickstoffanreicherung, in denen eine zusammenhaengende TiN-Schicht gebildet wird, sinkt der Wasserstoffanteil unter 1,5 at.% ab. Die Stickstoff-Implantation senkt die Lebensdauern im Umlaufbiegeversuch nicht signifikant ab, obwohl die Ermuedungsrisse bevorzugt von Probenbereichen ausgehen, in denen die Maximalgehalte von Stickstoff und Wasserstoff nahe an der Oberflaeche liegen. (orig.)

  12. Direct evidence of flat band voltage shift for TiN/LaO or ZrO/SiO2 stack structure via work function depth profiling.

    Science.gov (United States)

    Heo, Sung; Park, Hyoungsun; Ko, Dong-Su; Kim, Yong Su; Kyoung, Yong Koo; Lee, Hyung-Ik; Cho, Eunae; Lee, Hyo Sug; Park, Gyung-Su; Shin, Jai Kwang; Lee, Dongjin; Lee, Jieun; Jung, Kyoungho; Jeong, Moonyoung; Yamada, Satoru; Kang, Hee Jae; Choi, Byoung-Deog

    2017-03-02

    We demonstrated that a flat band voltage (VFB) shift could be controlled in TiN/(LaO or ZrO)/SiO2 stack structures. The VFB shift described in term of metal diffusion into the TiN film and silicate formation in the inserted (LaO or ZrO)/SiO2 interface layer. The metal doping and silicate formation confirmed by using transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) line profiling, respectively. The direct work function measurement technique allowed us to make direct estimate of a variety of flat band voltages (VFB). As a function of composition ratio of La or Zr to Ti in the region of a TiN/(LaO or ZrO)/SiO2/Si stack, direct work function modulation driven by La and Zr doping was confirmed with the work functions obtained from the cutoff value of secondary electron emission by auger electron spectroscopy (AES). We also suggested an analytical method to determine the interface dipole via work function depth profiling.

  13. Global transcriptome profile of Cryptococcus neoformans during exposure to hydrogen peroxide induced oxidative stress.

    Directory of Open Access Journals (Sweden)

    Rajendra Upadhya

    Full Text Available The ability of the opportunistic fungal pathogen Cryptococcus neoformans to resist oxidative stress is one of its most important virulence related traits. To cope with the deleterious effect of cellular damage caused by the oxidative burst inside the macrophages, C. neoformans has developed multilayered redundant molecular responses to neutralize the stress, to repair the damage and to eventually grow inside the hostile environment of the phagosome. We used microarray analysis of cells treated with hydrogen peroxide (H(2O(2 at multiple time points in a nutrient defined medium to identify a transcriptional signature associated with oxidative stress. We discovered that the composition of the medium in which fungal cells were grown and treated had a profound effect on their capacity to degrade exogenous H(2O(2. We determined the kinetics of H(2O(2 breakdown by growing yeast cells under different conditions and accordingly selected an appropriate media composition and range of time points for isolating RNA for hybridization. Microarray analysis revealed a robust transient transcriptional response and the intensity of the global response was consistent with the kinetics of H(2O(2 breakdown by treated cells. Gene ontology analysis of differentially expressed genes related to oxidation-reduction, metabolic process and protein catabolic processes identified potential roles of mitochondrial function and protein ubiquitination in oxidative stress resistance. Interestingly, the metabolic pathway adaptation of C. neoformans to H(2O(2 treatment was remarkably distinct from the response of other fungal organisms to oxidative stress. We also identified the induction of an antifungal drug resistance response upon the treatment of C. neoformans with H(2O(2. These results highlight the complexity of the oxidative stress response and offer possible new avenues for improving our understanding of mechanisms of oxidative stress resistance in C. neoformans.

  14. Diurnal odor, ammonia, hydrogen sulfide, and carbon dioxide emission profiles of confined swine grower/finisher rooms.

    Science.gov (United States)

    Sun, Gang; Guo, Huiqing; Peterson, Jonathan; Predicala, Bernardo; Laguë, Claude

    2008-11-01

    The objective of this study was to obtain diurnal variation profiles of odor and gas (ammonia [NH3], hydrogen sulfide [H2S], carbon dioxide [CO2]) concentrations and emission rate (OGCER) from confined swine grower/ finisher rooms under three typical weather conditions (warm, mild, and cold weather) in a year. Two grower/ finisher rooms, one with a fully slatted floor and the other with partially slatted floors, were measured for 2 consecutive days under each weather condition. The results revealed that the diurnal OGCER in the room with a fully slatted floor was 9.2-39.4% higher than that with a partially slatted floor; however, no significant differences in the diurnal OGCER were found between these two rooms, except for the NH3 concentrations in August, the NH3 and H2S concentrations and emissions in October, and odor concentrations and emissions in February (p > 0.05). The OGCER variations presented different diurnal patterns as affected by time of day, season, type of floor, ventilation rate, animal growth cycles, in-house manure storage, and weather conditions. Significant diurnal fluctuations in the OGCER (except for the odor concentrations and H2S emissions) were observed in August (p incertitude of setback determination using randomly measured data.

  15. Lidar Ratios for Dust Aerosols Derived From Retrievals of CALIPSO Visible Extinction Profiles Constrained by Optical Depths from MODIS-Aqua and CALIPSO/CloudSat Ocean Surface Reflectance Measurements

    Science.gov (United States)

    Young, Stuart A.; Josset, Damien B.; Vaughan, Mark A.

    2010-01-01

    CALIPSO's (Cloud Aerosol Lidar Infrared Pathfinder Satellite Observations) analysis algorithms generally require the use of tabulated values of the lidar ratio in order to retrieve aerosol extinction and optical depth from measured profiles of attenuated backscatter. However, for any given time or location, the lidar ratio for a given aerosol type can differ from the tabulated value. To gain some insight as to the extent of the variability, we here calculate the lidar ratio for dust aerosols using aerosol optical depth constraints from two sources. Daytime measurements are constrained using Level 2, Collection 5, 550-nm aerosol optical depth measurements made over the ocean by the MODIS (Moderate Resolution Imaging Spectroradiometer) on board the Aqua satellite, which flies in formation with CALIPSO. We also retrieve lidar ratios from night-time profiles constrained by aerosol column optical depths obtained by analysis of CALIPSO and CloudSat backscatter signals from the ocean surface.

  16. Depth profiling Li in electrode materials of lithium ion battery by {sup 7}Li(p,γ){sup 8}Be and {sup 7}Li(p,α){sup 4}He nuclear reactions

    Energy Technology Data Exchange (ETDEWEB)

    Sunitha, Y., E-mail: sunibarc@gmail.com; Kumar, Sanjiv

    2017-06-01

    A proton induced γ-ray emission method based on {sup 7}Li(p,γ){sup 8}Be proton capture reaction and a nuclear reaction analysis method involving {sup 7}Li(p,α){sup 4}He reaction are described for depth profiling Li in the electrode materials, graphite and lithium cobalt oxide for example, of a Li-ion battery. Depth profiling by {sup 7}Li(p,γ){sup 8}Be reaction is accomplished by the resonance at 441 keV and involves the measurement of 14.6 and 17.6 MeV γ-rays, characteristic of the reaction, by a NaI(Tl) detector. The method has a detection sensitivity of ∼0.2 at% and enables profiling up to a depth ≥20 µm with a resolution of ≥150 nm. The profiling to a fairly large depth is facilitated by the absence of any other resonance up to 1800 keV proton energy. The reaction has substantial off-resonance cross-sections. A procedure is outlined for evaluating the off-resonance yields. Interferences from fluorine and aluminium are major limitation of this depth profiling methodology. The depth profile measurement by {sup 7}Li(p,α){sup 4}He reaction, on the other hand, utilises 2–3 MeV protons and entails the detection of α-particles at 90° or 150° angles. The reaction exhibits inverse kinematics at 150°. This method, too, suffers interference from fluorine due to the simultaneous occurrence of {sup 19}F(p,α){sup 16}O reaction. Kinematical considerations show that the interference is minimal at 90° and thus is the recommended angle of detection. The method is endowed with a detection sensitivity of ∼0.1 at%, a depth resolution of ∼100 nm and a probing depth of about 30 µm in the absence and 5–8 µm in the presence of fluorine in the material. Both methods yielded comparable depth profiles of Li in the cathode (lithium cobalt oxide) and the anode (graphite) of a Li-ion battery.

  17. VERIFIKASI PERCENTAGE DEPTH DOSE (PDD) DAN PROFILE DOSE PESAWAT LINEAR ACCELERATOR (LINAC) BERKAS ELEKTRON 6 MeV, 9 MeV, 12 MeV DAN 15 MeV MENGGUNAKAN WATER PHANTOM

    OpenAIRE

    Marten Padang, Jumedi

    2015-01-01

    Abstrak Telah dilakukan penelitian tentang Verifikasi Percentage Depth Dose (PDD) dan Profile Dose Pesawat Linear Accelerator (LINAC) Berkas Elektron 6 MeV, 9 MeV, 12 MeV dan 15 MeV Menggunakan Water Phantom. Penelitian ini bertujuan untuk menganalisis Percentage Depth Dose (PDD) dan Profile Dose pesawat linac jenis HCX 5640 berkas elektron 6 MeV, 9 MeV, 12 MeV dan 15 MeV untuk luas lapangan 10 x 10 cm2. Penelitian ini membandingkan data acuan yang telah ada sebelumnya dan data yang dipero...

  18. XPS Depth Profile Analysis of Zn3N2 Thin Films Grown at Different N2/Ar Gas Flow Rates by RF Magnetron Sputtering.

    Science.gov (United States)

    Haider, M Baseer

    2017-12-01

    Zinc nitride thin films were grown on fused silica substrates at 300 °C by radio frequency magnetron sputtering. Films were grown at different N2/Ar flow rate ratios of 0.20, 0.40, 0.60, 0.80, and 1.0. All the samples have grain-like surface morphology with an average surface roughness ranging from 4 to 5 nm and an average grain size ranging from 13 to16 nm. Zn3N2 samples grown at lower N2/Ar ratio are polycrystalline with secondary phases of ZnO present, whereas at higher N2/Ar ratio, no ZnO phases were found. Highly aligned films were achieved at N2/Ar ratio of 0.60. Hall effect measurements reveal that films are n-type semiconductors, and the highest carrier concentration and Hall mobility was achieved for the films grown at N2/Ar ratio of 0.60. X-ray photoelectron study was performed to confirm the formation of Zn-N bonds and to study the presence of different species in the film. Depth profile XPS analyses of the films reveal that there is less nitrogen in the bulk of the film compared to the nitrogen on the surface of the film whereas more oxygen is present in the bulk of the films possibly occupying the nitrogen vacancies.

  19. Depth profile of production yields of {sup nat}Pb(p, xn) {sup 206,205,204,203,202,201}Bi nuclear reactions

    Energy Technology Data Exchange (ETDEWEB)

    Mokhtari Oranj, Leila [Division of Advanced Nuclear Engineering, POSTECH, Pohang 37673 (Korea, Republic of); Jung, Nam-Suk; Kim, Dong-Hyun; Lee, Arim; Bae, Oryun [Pohang Accelerator Laboratory, POSTECH, Pohang 37673 (Korea, Republic of); Lee, Hee-Seock, E-mail: lee@postech.ac.kr [Pohang Accelerator Laboratory, POSTECH, Pohang 37673 (Korea, Republic of)

    2016-11-01

    Experimental and simulation studies on the depth profiles of production yields of {sup nat}Pb(p, xn) {sup 206,205,204,203,202,201}Bi nuclear reactions were carried out. Irradiation experiments were performed at the high-intensity proton linac facility (KOMAC) in Korea. The targets, irradiated by 100-MeV protons, were arranged in a stack consisting of natural Pb, Al, Au foils and Pb plates. The proton beam intensity was determined by activation analysis method using {sup 27}Al(p, 3p1n){sup 24}Na, {sup 197}Au(p, p1n){sup 196}Au, and {sup 197}Au(p, p3n){sup 194}Au monitor reactions and also by Gafchromic film dosimetry method. The yields of produced radio-nuclei in the {sup nat}Pb activation foils and monitor foils were measured by HPGe spectroscopy system. Monte Carlo simulations were performed by FLUKA, PHITS/DCHAIN-SP, and MCNPX/FISPACT codes and the calculated data were compared with the experimental results. A satisfactory agreement was observed between the present experimental data and the simulations.

  20. Depth profiles of production yields of natPb(p, xn206,205,204,203,202 Bi reactions using 100-MeV proton beam

    Directory of Open Access Journals (Sweden)

    Oranj Leila Mokhtari

    2017-01-01

    Full Text Available In this study, results of the experimental study on the depth profiles of production yields of 206,205,204,203,202Bi radio-nuclei in the natural Pb target irradiated by a 100-MeV proton beam are presented. Irradiation was performed at proton linac facility (KOMAC in Korea. The target, irradiated by 100-MeV protons, was arranged in a stack consisting of natural Pb, Al, Au foils and Pb plates. The proton beam intensity was determined by activation analysis method using 27Al(p, 3p1n24Na, 197Au(p, p1n196Au, and 197Au(p, p3n194Au monitor reactions and also using dosimetry method by a Gafchromic film. The production yields of produced Bi radio-nuclei in the natural Pb foils and monitor reactions were measured by gamma-ray spectroscopy. Monte Carlo simulations were performed by FLUKA, PHITS, and MCNPX codes and compared with the measurements in order to verify validity of physical models and nuclear data libraries in the Monte Carlo codes. A fairly good agreement was observed between the present experimental data and the simulations by FLUKA, PHITS, and MCNPX. However, physical models and the nuclear data relevant to the end of range of protons in the codes need to be improved.

  1. Depth profiles of 230Th excess, transition metals and mineralogy of ferromanganese crusts of the Central Indian Ocean basin and implications for palaeoceanographic influence on crust genesis

    Digital Repository Service at National Institute of Oceanography (India)

    Banakar, V.K.; Borole, D.V.

    6 M HCl leachates of the depth samples using a Perkin Elmer@ 5000 atomic absorption spec- trometer (AAS). (Standard error lo; preci- sion within ? 6% ) . Mineralogical studies were carried out on depth samples using a Philips@ X...

  2. Temperature profile and water depth data collected from USS McInerney from expendable bathythermographs (XBT) in the Red Sea from 07 December 1992 to 28 December 1992 (NODC Accession 9300017)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USS McInerney in the Red Sea. Data were collected from 07 December 1992 to 28...

  3. Why bother about depth?

    DEFF Research Database (Denmark)

    Stæhr, Peter A.; Obrador, Biel; Christensen, Jesper Philip

    We present results from a newly developed method to determine depth specific rates of GPP, NEP and R using frequent automated profiles of DO and temperature. Metabolic rate calculations were made for three lakes of different trophic status using a diel DO methodology that integrates rates across...

  4. Drill bit seismic, vertical seismic profiling, and seismic depth imaging to aid drilling decisions in the Tho Tinh structure, Nam Con Son basin, Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    Borland, W.; Hayashida, N.; Kusaka, H.; Leaney, W.; Nakanishi, S.

    1996-10-01

    This paper reviews the problem of overpressure, a common reason for acquiring look-ahead VSPs, and the seismic trace inversion problem, a fundamental issue in look-ahead prediction. The essential components of intermediate VSPs were examined from acquisition through processing to inversion, and recently acquired real data were provided, which were indicative of the advances being made toward developing an exclusive high resolution VSP service. A simple interpretation method and an end product of predicted mud weight versus depth were also presented, which were obtained from the inverted acoustic impedance and empirical relations. Of paramount importance in predicting the depth to a target was the velocity function used below the intermediate TD. The use of empirical or assumed density functions was an obvious weak link in the procedure. The advent of real-time time-depth measurements from drill bit seismic allowed a continuously updated predicted target depth below the present bit depth. 8 refs., 7 figs.

  5. Counter-diffusion biofilms have lower N2O emissions than co-diffusion biofilms during simultaneous nitrification and denitrification: Insights from depth-profile analysis.

    Science.gov (United States)

    Kinh, Co Thi; Suenaga, Toshikazu; Hori, Tomoyuki; Riya, Shohei; Hosomi, Masaaki; Smets, Barth F; Terada, Akihiko

    2017-11-01

    The goal of this study was to investigate the effectiveness of a membrane-aerated biofilm reactor (MABR), a representative of counter-current substrate diffusion geometry, in mitigating nitrous oxide (N2O) emission. Two laboratory-scale reactors with the same dimensions but distinct biofilm geometries, i.e., a MABR and a conventional biofilm reactor (CBR) employing co-current substrate diffusion geometry, were operated to determine depth profiles of dissolved oxygen (DO), nitrous oxide (N2O), functional gene abundance and microbial community structure. Surficial nitrogen removal rate was slightly higher in the MABR (11.0 ± 0.80 g-N/(m(2) day) than in the CBR (9.71 ± 0.94 g-N/(m(2) day), while total organic carbon removal efficiencies were comparable (96.9 ± 1.0% for MABR and 98.0 ± 0.8% for CBR). In stark contrast, the dissolved N2O concentration in the MABR was two orders of magnitude lower (0.011 ± 0.001 mg N2O-N/L) than that in the CBR (1.38 ± 0.25 mg N2O-N/L), resulting in distinct N2O emission factors (0.0058 ± 0.0005% in the MABR vs. 0.72 ± 0.13% in the CBR). Analysis on local net N2O production and consumption rates unveiled that zones for N2O production and consumption were adjacent in the MABR biofilm. Real-time quantitative PCR indicated higher abundance of denitrifying genes, especially nitrous oxide reductase (nosZ) genes, in the MABR versus the CBR. Analyses of the microbial community composition via 16S rRNA gene amplicon sequencing revealed the abundant presence of the genera Thauera (31.2 ± 11%), Rhizobium (10.9 ± 6.6%), Stenotrophomonas (6.8 ± 2.7%), Sphingobacteria (3.2 ± 1.1%) and Brevundimonas (2.5 ± 1.0%) as potential N2O-reducing bacteria in the MABR. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Depth profile investigation of β-FeSi{sub 2} formed in Si(1 0 0) by high fluence implantation of 50 keV Fe ion and post-thermal vacuum annealing

    Energy Technology Data Exchange (ETDEWEB)

    Lakshantha, Wickramaarachchige J.; Kummari, Venkata C.; Reinert, Tilo; McDaniel, Floyd D. [Ion Beam Modification and Analysis Laboratory, Department of Physics, University of North Texas, 1155 Union Circle #311427, Denton, TX 76203 (United States); Rout, Bibhudutta, E-mail: bibhu@unt.edu [Ion Beam Modification and Analysis Laboratory, Department of Physics, University of North Texas, 1155 Union Circle #311427, Denton, TX 76203 (United States); Center for Advanced Research and Technology, University of North Texas, 3940 North Elm Street, Denton, TX 76207 (United States)

    2014-08-01

    A single phase polycrystalline β-FeSi{sub 2} layer has been synthesized at the near surface region by implantation in Si(1 0 0) of a high fluence (∼10{sup 17} atoms/cm{sup 2}) of 50 keV Fe ions and subsequent thermal annealing in vacuum at 800 °C. The depth profile of the implanted Fe atoms in Si(1 0 0) were simulated by the widely used transportation of ions in matter (TRIM) computer code as well as by the dynamic transportation of ions in matter code (T-DYN). The simulated depth profile predictions for this heavy ion implantation process were experimentally verified using Rutherford Backscattering Spectrometry (RBS) and X-ray Photoelectron Spectroscopy (XPS) in combination with Ar-ion etching. The formation of the β-FeSi{sub 2} phase was monitored by X-ray diffraction measurements. The T-DYN simulations show better agreement with the experimental Fe depth profile results than the static TRIM simulations. The experimental and T-DYN simulated results show an asymmetric distribution of Fe concentrated more toward the surface region of the Si substrate.

  7. Quantitative depth profiling of Si{sub 1–x}Ge{sub x} structures by time-of-flight secondary ion mass spectrometry and secondary neutral mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Drozdov, M.N.; Drozdov, Y.N. [Institute for Physics of Microstructures of the Russian Academy of Sciences (IPM RAS), 603950 Nizhniy Novgorod (Russian Federation); Lobachevski Nizhniy Novgorod State University, 603950 Nizhniy Novgorod (Russian Federation); Csik, A. [Institute for Nuclear Research (INR), Hungarian Academy of Science, Bem tér 18/C, 4026 Debrecen (Hungary); Novikov, A.V. [Institute for Physics of Microstructures of the Russian Academy of Sciences (IPM RAS), 603950 Nizhniy Novgorod (Russian Federation); Lobachevski Nizhniy Novgorod State University, 603950 Nizhniy Novgorod (Russian Federation); Vad, K. [Institute for Nuclear Research (INR), Hungarian Academy of Science, Bem tér 18/C, 4026 Debrecen (Hungary); Yunin, P.A.; Yurasov, D.V. [Institute for Physics of Microstructures of the Russian Academy of Sciences (IPM RAS), 603950 Nizhniy Novgorod (Russian Federation); Lobachevski Nizhniy Novgorod State University, 603950 Nizhniy Novgorod (Russian Federation); Belykh, S.F. [MATI Russian State Technological University, Orshanskaya Str. 3, 121552 Moscow (Russian Federation); Gololobov, G.P.; Suvorov, D.V. [Ryazan State Radio Engineering University, Gagarin Str. 59/1, 390005 Ryazan (Russian Federation); Tolstogouzov, A., E-mail: a.tolstoguzov@fct.unl.pt [Ryazan State Radio Engineering University, Gagarin Str. 59/1, 390005 Ryazan (Russian Federation); Centre for Physics and Technological Research (CeFITec), Dept. de Física da Faculdade de Ciências e Tecnologia (FCT), Universidade Nova de Lisboa, 2829-516 Caparica (Portugal)

    2016-05-31

    Quantification of Ge in Si{sub 1–x}Ge{sub x} structures (0.092 ≤ x ≤ 0.78) was carried out by time-of-flight secondary ion mass spectrometry (TOF-SIMS) and electron-gas secondary neutral mass spectrometry (SNMS). A good linear correlation (R{sup 2} > 0.9997) of the intensity ratios of secondary ions GeCs{sub 2}{sup +}/SiCs{sub 2}{sup +} and {sup 74}Ge{sup −}/{sup 30}Si{sup −} and post-ionized sputtered neutrals {sup 70}Ge{sup +}/{sup 28}Si{sup +} with Ge concentration was obtained. The calibration data were used for quantitative depth profiling of [10 × (12.3 nm Si{sub 0.63}Ge{sub 0.37}/34 nm Si)] structures on Si. Satisfactory compliance of the quantified Ge concentration in SiGe layers with the values obtained by high-resolution X-ray diffraction was revealed for both techniques. SIMS and SNMS experimental profiles were fitted using Hofmann's mixing-roughness-information depth (MRI) model. In the case of TOF-SIMS, the quality of the reconstruction was better than for SNMS since not only the progressing roughening, but also the crater effect and other processes unaccounted in the MRI simulation could have a significant impact on plasma sputter depth profiling.

  8. PDEPTH—A computer program for the geophysical interpretation of magnetic and gravity profiles through Fourier filtering, source-depth analysis, and forward modeling

    Science.gov (United States)

    Phillips, Jeffrey D.

    2018-01-10

    PDEPTH is an interactive, graphical computer program used to construct interpreted geological source models for observed potential-field geophysical profile data. The current version of PDEPTH has been adapted to the Windows platform from an earlier DOS-based version. The input total-field magnetic anomaly and vertical gravity anomaly profiles can be filtered to produce derivative products such as reduced-to-pole magnetic profiles, pseudogravity profiles, pseudomagnetic profiles, and upward-or-downward-continued profiles. A variety of source-location methods can be applied to the original and filtered profiles to estimate (and display on a cross section) the locations and physical properties of contacts, sheet edges, horizontal line sources, point sources, and interface surfaces. Two-and-a-half-dimensional source bodies having polygonal cross sections can be constructed using a mouse and keyboard. These bodies can then be adjusted until the calculated gravity and magnetic fields of the source bodies are close to the observed profiles. Auxiliary information such as the topographic surface, bathymetric surface, seismic basement, and geologic contact locations can be displayed on the cross section using optional input files. Test data files, used to demonstrate the source location methods in the report, and several utility programs are included.

  9. Concentration and depth profiles of elements in Si {sub x}N {sub y}H {sub z}/Si thin films produced by PECVD

    Energy Technology Data Exchange (ETDEWEB)

    Murillo, G. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico, DF (Mexico); Andrade, E. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, A.P. 20-364, 01000 Mexico, DF (Mexico)]. E-mail: andrade@fisica.unam.mx; Alonso, J.C. [Instituto de Investigaciones en Materiales, UNAM, Ciudad Universitaria, A.P. 70-360, 04510 Mexico, DF (Mexico); Acosta, L. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, A.P. 20-364, 01000 Mexico, DF (Mexico); Rocha, M.F. [Escuela Superior de Ingenieria Mecanica y Electrica, IPN, C.P. 07738, Mexico, DF (Mexico); Zavala, E.P. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, A.P. 20-364, 01000 Mexico, DF (Mexico); Policroniades, R. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico, DF (Mexico)

    2006-08-15

    Plasma enhanced chemical vapor deposition (PECVD) with SiH{sub 4}/NH{sub 3} mixtures was used to produce silicon nitride thin films on silicon substrates. These types of films are commonly used as dielectrics in modern semiconductor technology; however, the incorporation of large amounts of hydrogen affects negatively their stability and electrical properties. Therefore, quantifications of the hydrogen content and chemical composition of these films are required. Forward elastic scattering using a 10 MeV {sup 12}C{sup 3+} beam was used to determine the thickness and stoichiometry of the films. Nuclear reaction analysis (NRA) using a 0.825 MeV deuterium beam was also applied to measure the low concentrations of oxygen and carbon in these films. The chemical structure of the silicon nitride layers was studied using infrared spectroscopy.

  10. CRED Acoustic Doppler Profiler (ADP); AMSM, ROS; Long: -168.15481, Lat: -14.53510 (WGS84); Sensor Depth: 7.01m; Data Range: 20080311-20080314.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data from Coral Reef Ecosystem Division (CRED), NOAA Pacific Island Fisheries Science Center Acoustic Doppler Profilers (ADP) provide a time series of water current...

  11. CRED Acoustic Doppler Profiler (ADP); NWHI, MID; Long: -177.42181, Lat: 28.21826 (WGS84); Sensor Depth: 1.83m; Data Range: 20080926-20090321.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data from Coral Reef Ecosystem Division (CRED), NOAA Pacific Island Fisheries Science Center Acoustic Doppler Profilers (ADP) provide a time series of water current...

  12. Parallel detection, quantification, and depth profiling of peptides with dynamic-secondary ion mass spectrometry (D-SIMS) ionized by C{sub 60}{sup +}-Ar{sup +} co-sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Chi-Jen [Department of Materials Science and Engineering, National Taiwan University, Taipei 106, Taiwan (China); Chang, Hsun-Yun; You, Yun-Wen; Liao, Hua-Yang [Research Center for Applied Sciences, Academia Sinica, Taipei 115, Taiwan (China); Kuo, Yu-Ting; Kao, Wei-Lun; Yen, Guo-Ji; Tsai, Meng-Hung [Department of Materials Science and Engineering, National Taiwan University, Taipei 106, Taiwan (China); Shyue, Jing-Jong, E-mail: shyue@gate.sinica.edu.tw [Department of Materials Science and Engineering, National Taiwan University, Taipei 106, Taiwan (China); Research Center for Applied Sciences, Academia Sinica, Taipei 115, Taiwan (China)

    2012-03-09

    Highlights: Black-Right-Pointing-Pointer Multiple peptides are detected and quantified at the same time without labeling. Black-Right-Pointing-Pointer C{sub 60}{sup +} ion is responsible for generating molecular-specific ions at high mass. Black-Right-Pointing-Pointer The co-sputtering yielded more steady depth profile and more well defined interface. Black-Right-Pointing-Pointer The fluence of auxiliary Ar{sup +} does not affect the quantification curve. Black-Right-Pointing-Pointer The damage from Ar{sup +} is masked by high sputtering yield of C{sub 60}{sup +}. - Abstract: Time-of-flight secondary ion mass spectrometry (ToF-SIMS) using pulsed C{sub 60}{sup +} primary ions is a promising technique for analyzing biological specimens with high surface sensitivities. With molecular secondary ions of high masses, multiple molecules can be identified simultaneously without prior separation or isotope labeling. Previous reports using the C{sub 60}{sup +} primary ion have been based on static-SIMS, which makes depth profiling complicated. Therefore, a dynamic-SIMS technique is reported here. Mixed peptides in the cryoprotectant trehalose were used as a model for evaluating the parameters that lead to the parallel detection and quantification of biomaterials. Trehalose was mixed separately with different concentrations of peptides. The peptide secondary ion intensities (normalized with respect to those of trehalose) were directly proportional to their concentration in the matrix (0.01-2.5 mol%). Quantification curves for each peptide were generated by plotting the percentage of peptides in trehalose versus the normalized SIMS intensities. Using these curves, the parallel detection, identification, and quantification of multiple peptides was achieved. Low energy Ar{sup +} was used to co-sputter and ionize the peptide-doped trehalose sample to suppress the carbon deposition associated with C{sub 60}{sup +} bombardment, which suppressed the ion intensities during the depth

  13. Ground-Penetrating-Radar Profiles of Interior Alaska Highways: Interpretation of Stratified Fill, Frost Depths, Water Table, and Thaw Settlement over Ice-Rich Permafrost

    Science.gov (United States)

    2016-08-01

    Interpretation of Stratified Fill, Frost Depths, Water Table, and Thaw Settlement over Ice-Rich Permafrost Co ld R eg io ns R es ea rc h an d En...within the discontinuous permafrost zone ............................................................. 7 4 (A) 1958 surficial geology map (Péwé...looking north and reveals that the valley walls are not steep. Figure 4. (A) 1958 surficial geology map (Péwé 1958) showing that the Elliott

  14. Reduction of a thin chromium oxide film on Inconel surface upon treatment with hydrogen plasma

    Energy Technology Data Exchange (ETDEWEB)

    Vesel, Alenka, E-mail: alenka.vesel@guest.arnes.si [Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana (Slovenia); Mozetic, Miran [Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana (Slovenia); Balat-Pichelin, Marianne [PROMES-CNRS Laboratory, 7 Rue du four solaire, 66120 Font Romeu Odeillo (France)

    2016-11-30

    Highlights: • Oxidized Inconel alloy was exposed to hydrogen at temperatures up to 1500 K. • Oxide reduction in hydrogen plasma started at approximately 1300 K. • AES depth profiling revealed complete reduction of oxides in plasma. • Oxides were not reduced, if the sample was heated just in hydrogen atmosphere. • Surface of reduced Inconel preserved the same composition as the bulk material. - Abstract: Inconel samples with a surface oxide film composed of solely chromium oxide with a thickness of approximately 700 nm were exposed to low-pressure hydrogen plasma at elevated temperatures to determine the suitable parameters for reduction of the oxide film. The hydrogen pressure during treatment was set to 60 Pa. Plasma was created by a surfaguide microwave discharge in a quartz glass tube to allow for a high dissociation fraction of hydrogen molecules. Auger electron depth profiling (AES) was used to determine the decay of the oxygen in the surface film and X-ray diffraction (XRD) to measure structural modifications. During hydrogen plasma treatment, the oxidized Inconel samples were heated to elevated temperatures. The reduction of the oxide film started at temperatures of approximately 1300 K (considering the emissivity of 0.85) and the oxide was reduced in about 10 s of treatment as revealed by AES. The XRD showed sharper substrate peaks after the reduction. Samples treated in hydrogen atmosphere under the same conditions have not been reduced up to approximately 1500 K indicating usefulness of plasma treatment.

  15. Opto-thermal transient emission radiometry for rapid, non-destructive and non-contact determination of hydration and hydration depth profile in the skin of a grape

    NARCIS (Netherlands)

    Guo, X.; Bicanic, D.D.; Keijser, K.; Imhof, R.

    2003-01-01

    .The concept of optothermal transient emission radiometry at a wavelength of 2.94 µm was applied to non-destructively determine the level of hydration and the profile of hydration in the skin of intact fresh grapes taken from top and bottom sections of the same bunch.

  16. Measurements of neutral hydrogen profiles on the EXTRAP-T2 reversed-field pinch from time-resolved ? line emission

    Science.gov (United States)

    Sallander, J.; Hedqvist, A.; Rachlew-Källne, E.

    1998-09-01

    The investigations of the radial distributions of 0953-4075/31/17/015/img2 emission from the EXTRAP-T2 reversed-field pinch (RFP) plasma show that the emission profile varies a lot, even during one plasma discharge. At central electron temperatures of about 150 eV it was expected that the 0953-4075/31/17/015/img2 emission should emerge from the plasma centre. In comparison, 0953-4075/31/17/015/img4 is always observed to radiate from the centre. Our measurements of 0953-4075/31/17/015/img2 emission have, however, shown that this is not always the case, the emission often comes from the plasma edge. The analysis of the measurements has led us to conclude that the edge emission comes from charge-exchange recombination with neutral hydrogen near the carbon first wall. These observations provide a way to estimate the change in neutral hydrogen density during local plasma-wall interaction.

  17. Interaction of hydrogen plasma with carbon-tungsten composite layer

    Energy Technology Data Exchange (ETDEWEB)

    Vesel, Alenka, E-mail: alenka.vesel@guest.arnes.s [Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Mozetic, Miran; Panjan, Peter [Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Hauptman,; Klanjsek-Gunde, M. [National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); Balat-Pichelin, Marianne [CNRS-PROMES, Laboratoire Procedes, Materiaux and Energie Solaire, UPR 8521, 7 rue du four solaire, F-66120 Font Romeu, Odeillo (France)

    2011-04-15

    Interaction of neutral hydrogen atoms with the layer of hydrogenated carbon-tungsten composite was studied. A 1 {mu}m thick layer was prepared by sputter deposition from C and WC-targets in Ar/C{sub 2}-H{sub 2} gas mixture. After deposition the samples were treated in weakly ionized highly dissociated hydrogen plasma created in a microwave discharge at a power of 1 kW. The gas flow was 13 l/h and pressure was 90 Pa. Temperature of the samples during treatment was about 850 K. After plasma treatment the samples were analyzed by AES (Auger electron spectroscopy) depth profiling, XPS (X-ray photoelectron spectroscopy) and SEM (scanning electron microscopy). It was found that during hydrogen plasma treatment selective etching of the C-W layer occurred. Carbon was preferentially removed from the C-W layer, and after about 10 min of treatment practically only tungsten with a huge porosity was detected.

  18. Depth-Recursive Tomography Along the Eger Rift Using the S01 Profile Refraction Data: Tested at the KTB Super Drilling Hole, Structural Interpretation Supported by Magnetic, Gravity and Petrophysical Data

    Science.gov (United States)

    Novotný, Miroslav; Skácelová, Zuzana; Mrlina, Jan; Mlčoch, Bedřich; Růžek, Bohuslav

    2009-11-01

    The refraction data from the SUDETES 2003 experiment were used for high-resolution tomography along the profile S01. The S01 profile crosses the zone Erbendorf-Vohenstrauss (ZEV) near the KTB site, then follows the SW-NE oriented Eger Rift in the middle part and continues toward the NE across the Elbe zone and the Sudetic structures as far as the Trans-European Suture Zone. To get the best resolution in the velocity image only the first arrivals of Pg waves with minimum picking errors were used. The previous depth-recursive tomographic method, based on Claerbout’s imaging principle, has been adapted to perform the linearized inversions in iterative mode. This innovative DRTG method (Depth-Recursive Tomography on Grid) uses a regular system of refraction rays covering uniformly the mapped domain. The DRTG iterations yielded a fine-grid velocity model with a required level of RMS travel-time fit and the model roughness. The travel-time residuals, assessed at single depth levels, were used to derive the statistical lateral resolution of “lens-shaped” velocity anomalies. Thus, for the 95% confidence level and 5% anomalies, one can resolve their lateral sizes from 15 to 40 km at the depths from 0 to 20 km. The DRTG tomography succeeded in resolving a significant low-velocity zone (LVZ) bound to the Franconian lineament nearby the KTB site. It is shown that the next optimization of the model best updated during the DRTG iterations tends to a minimum-feature model with sweeping out any LVZs. The velocities derived by the depth-recursive tomography relate to the horizontal directions of wave propagation rather than to the vertical. This was proved at the KTB site where pronounced anisotropic behavior of a steeply tilted metamorphic rock complex of the ZEV unit has been previously determined. Involving a ~7% anisotropy observed for the “slow” axis of symmetry oriented coincidentally in the horizontal SW-NE direction of the S01 profile, the DRTG velocity model

  19. The annealing behavior of hydrogen implanted into Al-Si alloy

    Energy Technology Data Exchange (ETDEWEB)

    Ogura, Masahiko; Yamaji, Norisuke; Imai, Makoto; Itoh, Akio; Imanishi, Nobutsugu [Kyoto Univ. (Japan). Faculty of Engineering

    1997-03-01

    We have studied effects of not only defects but also an added elements on trap-sites of hydrogen in metals. For the purpose, we observed depth profiles and thermal behaviors of hydrogen implanted into Al-1.5at.%Si alloy samples in an implantation-temperature range of liquid nitrogen temperature (LNT) to 373K at different doses. The results were compared with those for pure aluminum samples. It was found that hydrogen is trapped as molecules in grain boundaries of Al/Si. (author)

  20. Oxygen depth profiling in Kr{sup +}-implanted polycrystalline alpha titanium by means of {sup 16}O({alpha},{alpha}){sup 16}O resonance scattering

    Energy Technology Data Exchange (ETDEWEB)

    Nsengiyumva, S., E-mail: schadnse@hotmail.com [Department of Physics, University of Cape Town, Rondebosch 7701 (South Africa); Department of Physics and Electronics, Rhodes University, Grahamstown 6140 (South Africa); Department of Physics, Kigali Institute of Education, P.O. Box 5039 Kigali (Rwanda); Riviere, J.P. [Laboratoire de Physique des Materiaux UMR6630-CNRS, 86960 (France); Raji, A.T.; Comrie, C.M.; Britton, D.T.; Haerting, M. [Department of Physics, University of Cape Town, Rondebosch 7701 (South Africa)

    2011-07-15

    The {sup 16}O({alpha},{alpha}){sup 16}O resonance scattering was applied to study the effects of ion implantation on the oxygen distribution in the near surface region of polycrystalline titanium implanted with 180 keV krypton ions at fluences, ranging between 1 x 10{sup 14} and 5 x 10{sup 15} Kr{sup +}/cm{sup 2}. Two sample sets were chosen: as-received polycrystalline titanium discs rolled and annealed in half-hard condition which had a thick oxygen layer and similar samples in which this surface layer was removed by polishing. An increase of the mean oxygen concentration observed in both unpolished and polished samples at low fluence suggests a knock-on implantation of surface oxygen atoms. At high fluence, an overall decrease in the mean oxygen concentration and mean oxygen depth suggests an out-diffusion of near-surface oxygen atoms.

  1. AES depth profiles in Mo-coated 304L stainless steel achieved by RF-magnetron sputtering and influence of Mo on the corrosion in 3.5% NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Saidi, D. [Département de métallurgie, Division de Technologie du Combustible, Centre de Recherche Nucléaire de Draria CRND, BP. 43 Draria, Alger (Algeria); Zaid, B., E-mail: zaidbachir@yahoo.com [Département de métallurgie, Division de Technologie du Combustible, Centre de Recherche Nucléaire de Draria CRND, BP. 43 Draria, Alger (Algeria); Souami, N. [Centre de Recherche Nucléaire d’Alger CRNA, 2 Bd. Frantz Fanon, Alger (Algeria); Saoula, N. [Division des Milieux Ionisés et Lasers, Centre de Développement des Technologies Avancées CDTA, Cité du 20 août 1956, Baba Hassan, BP n 17, Alger (Algeria); Siad, M. [Centre de Recherche Nucléaire d’Alger CRNA, 2 Bd. Frantz Fanon, Alger (Algeria); Si Ahmed, A. [Im2np, UMR 7334 CNRS, Aix-Marseille Université, 13397 Marseille Cedex 20 (France); Biberian, J.P. [CINaM, UMR 7525 CNRS, Aix Marseille Université, 13288 Marseille Cedex 9 (France)

    2015-10-05

    Highlights: • Mo coating of 304L stainless steel is achieved via RF-magnetron sputtering. • The AES depth profiles before and after annealing in air (at 973 K) are analyzed. • The corrosions in NaCl solution of bare and Mo-coated samples are compared. • Mo-coated steels exhibit better corrosion behaviors. • The positive action of Mo oxide via its semi-conducting properties is deduced. - Abstract: Molybdenum-coated 304L stainless steel samples, fabricated by RF-magnetron sputtering, are characterized by Auger Electron Spectroscopy (AES) before and after annealing in air at 973 K. The electrochemical parameters of bare and coated materials, in NaCl 3.5% water solution at 298 K, are derived from the potentiodynamic polarization curves. The corrosion current of Mo-coated samples (before and after annealing) is significantly lower than that of its bare counterpart. The information gained from the AES depth profiles leads us to infer that the positive action of molybdenum on the corrosion behavior may be attributed to the changes induced by the semi-conducting properties of Mo oxide in the passive film.

  2. A new, simple and precise method for measuring cyclotron proton beam energies using the activity vs. depth profile of zinc-65 in a thick target of stacked copper foils.

    Science.gov (United States)

    Asad, A H; Chan, S; Cryer, D; Burrage, J W; Siddiqui, S A; Price, R I

    2015-11-01

    The proton beam energy of an isochronous 18MeV cyclotron was determined using a novel version of the stacked copper-foils technique. This simple method used stacked foils of natural copper forming 'thick' targets to produce Zn radioisotopes by the well-documented (p,x) monitor-reactions. Primary beam energy was calculated using the (65)Zn activity vs. depth profile in the target, with the results obtained using (62)Zn and (63)Zn (as comparators) in close agreement. Results from separate measurements using foil thicknesses of 100, 75, 50 or 25µm to form the stacks also concurred closely. Energy was determined by iterative least-squares comparison of the normalized measured activity profile in a target-stack with the equivalent calculated normalized profile, using 'energy' as the regression variable. The technique exploits the uniqueness of the shape of the activity vs. depth profile of the monitor isotope in the target stack for a specified incident energy. The energy using (65)Zn activity profiles and 50-μm foils alone was 18.03±0.02 [SD] MeV (95%CI=17.98-18.08), and 18.06±0.12MeV (95%CI=18.02-18.10; NS) when combining results from all isotopes and foil thicknesses. When the beam energy was re-measured using (65)Zn and 50-μm foils only, following a major upgrade of the ion sources and nonmagnetic beam controls the results were 18.11±0.05MeV (95%CI=18.00-18.23; NS compared with 'before'). Since measurement of only one Zn monitor isotope is required to determine the normalized activity profile this indirect yet precise technique does not require a direct beam-current measurement or a gamma-spectroscopy efficiency calibrated with standard sources, though a characteristic photopeak must be identified. It has some advantages over published methods using the ratio of cross sections of monitor reactions, including the ability to determine energies across a broader range and without need for customized beam degraders. Copyright © 2015 Elsevier Ltd. All rights

  3. Collision cascades enhanced hydrogen redistribution in cobalt implanted hydrogenated diamond-like carbon films

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, P. [National Isotope Centre, GNS Science, Lower Hutt (New Zealand); The MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington (New Zealand); Becker, H.-W. [RUBION, Ruhr-University Bochum (Germany); Williams, G.V.M. [The MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington (New Zealand); Hübner, R.; Heinig, K.-H. [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf (Germany); Markwitz, A., E-mail: a.markwitz@gns.cri.nz [National Isotope Centre, GNS Science, Lower Hutt (New Zealand); The MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington (New Zealand)

    2017-03-01

    Highlights: • This paper reports for the first time redistribution of hydrogen atoms in diamond like carbon thin films during ion implantation of low energy magnetic ions. • The results point towards new routes of controlling the composition and distribution of elements at the nanoscale within a base matrix without using any heat treatment methods. • Exploring these opportunities can lead to a new horizon of materials and device engineering needed for enabling advanced technologies and applications. - Abstract: Hydrogenated diamond-like carbon films produced by C{sub 3}H{sub 6} deposition at 5 kV and implanted at room temperature with 30 keV Co atoms to 12 at.% show not only a bimodal distribution of Co atoms but also a massive redistribution of hydrogen in the films. Resonant nuclear reaction analysis was used to measure the hydrogen depth profiles (15N-method). Depletion of hydrogen near the surface was measured to be as low as 7 at.% followed by hydrogen accumulation from 27 to 35 at.%. A model is proposed considering the thermal energy deposited by collision cascade for thermal insulators. In this model, sufficient energy is provided for dissociated hydrogen to diffuse out of the sample from the surface and diffuse into the sample towards the interface which is however limited by the range of the incoming Co ions. At a hydrogen concentration of ∼35 at.%, the concentration gradient of the mobile unbounded hydrogen atoms is neutralised effectively stopping diffusion towards the interface. The results point towards new routes of controlling the composition and distribution of elements at the nanoscale within a base matrix without using any heat treatment methods. Exploring these opportunities can lead to a new horizon of materials and device engineering needed for enabling advanced technologies and applications.

  4. Depth profiling study of in situ CdCl{sub 2} treated CdTe/CdS heterostructure with glancing angle incidence X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Vamsi Krishna, K.; Dutta, V

    2004-03-01

    CdTe thin films have been deposited using spray pyrolysis technique without and with in situ CdCl{sub 2} treatment. Scanning electron microscopy studies show enhanced grain growth in the presence of CdCl{sub 2}. Glancing angle incidence X-ray diffraction is used for the micro structural study of polycrystalline CdS/CdTe heterostructure at different depths by changing the incident angle. Spraying of CdCl{sub 2} on CdS prior to CdTe deposition promotes S diffusion throughout CdTe film and also Te diffusion into CdS. Whereas spraying of CdCl{sub 2} in between CdTe deposition prevents S diffusion partially and Te diffusion completely. There is an associated change in the microstress of the CdTe film at different layers. The films without CdCl{sub 2} treatment show compressive microstress varying from -98 to -158 MPa with increasing incident angle. CdCl{sub 2} spray during CdTe deposition shows compressive microstress, which varies from -98 MPa at the interface to -19 MPa near the surface and CdCl{sub 2} spray prior to CdTe deposition leads to a mildly tensile stress, from +40 to +20 MPa, which is very close to the standard shear stress of {approx}10 MPa for CdTe.

  5. Sequential enzymatic derivatization coupled with online microdialysis sampling for simultaneous profiling of mouse tumor extracellular hydrogen peroxide, lactate, and glucose.

    Science.gov (United States)

    Su, Cheng-Kuan; Tseng, Po-Jen; Chiu, Hsien-Ting; Del Vall, Andrea; Huang, Yu-Fen; Sun, Yuh-Chang

    2017-03-01

    Probing tumor extracellular metabolites is a vitally important issue in current cancer biology. In this study an analytical system was constructed for the in vivo monitoring of mouse tumor extracellular hydrogen peroxide (H2O2), lactate, and glucose by means of microdialysis (MD) sampling and fluorescence determination in conjunction with a smart sequential enzymatic derivatization scheme-involving a loading sequence of fluorogenic reagent/horseradish peroxidase, microdialysate, lactate oxidase, pyruvate, and glucose oxidase-for step-by-step determination of sampled H2O2, lactate, and glucose in mouse tumor microdialysate. After optimization of the overall experimental parameters, the system's detection limit reached as low as 0.002 mM for H2O2, 0.058 mM for lactate, and 0.055 mM for glucose, based on 3 μL of microdialysate, suggesting great potential for determining tumor extracellular concentrations of lactate and glucose. Spike analyses of offline-collected mouse tumor microdialysate and monitoring of the basal concentrations of mouse tumor extracellular H2O2, lactate, and glucose, as well as those after imparting metabolic disturbance through intra-tumor administration of a glucose solution through a prior-implanted cannula, were conducted to demonstrate the system's applicability. Our results evidently indicate that hyphenation of an MD sampling device with an optimized sequential enzymatic derivatization scheme and a fluorescence spectrometer can be used successfully for multi-analyte monitoring of tumor extracellular metabolites in living animals. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Depth Profile Assessment of the Early Phase Deposition of Lysozyme on Soft Contact Lens Materials Using a Novel In Vitro Eye Model.

    Science.gov (United States)

    Qiao, Han; Phan, Chau-Minh; Walther, Hendrik; Subbaraman, Lakshman N; Jones, Lyndon

    2017-08-08

    To characterize the location of fluorescently labeled lysozyme on commercial contact lenses (CLs) using an in vitro eye model that simulates tear volume, tear flow, air exposure, and mechanical wear. One commercially available conventional hydrogel CL material (etafilcon A) and three silicone hydrogel CL materials (balafilcon A, lotrafilcon B, and senofilcon A) were evaluated in this study. The CLs were mounted on the in vitro eye model and exposed to artificial tear fluid containing fluorescein isothiocyanate (FITC)-labeled lysozyme for 2 and 10 hrs. After these short incubation periods, circular discs were punched from the CLs at the center and periphery and were prepared for confocal laser scanning microscopy (CLSM). The CLSM captured a series of consecutive images spaced 5 μm apart, and the resulting images were rendered into two dimensional cross-sectional views of the CL. The mean fluorescence at each 5 μm slice was used to generate a histogram depicting the penetration of FITC-lysozyme into CLs. For both incubation periods, the CLSM images and histogram of etafilcon A showed that FITC-lysozyme is more concentrated at the lens surface, with a moderate amount of deposition in the lens matrix. For balafilcon A, FITC-lysozyme was evenly distributed throughout the lens. For lotrafilcon B, there was a greater amount of FITC-lysozyme deposition on the surfaces of the lens versus the matrix. Senofilcon A had differential FITC-lysozyme distribution profiles depending on the location of the lens. At the lens periphery, FITC-lysozyme primarily deposited on the surface, whereas FITC-lysozyme was uniformly distributed at the center of the lens. With the use of a sophisticated in vitro eye model, the study revealed a complex deposition pattern of FITC-labeled lysozyme on various CL materials after short periods of exposure. An understanding of the early deposition pattern of lysozyme on different CL material may elucidate new insights into the processes behind CL

  7. Differences between GaAs/GaInP and GaAs/AlInP interfaces grown by movpe revealed by depth profiling and angle-resolved X-ray photoelectron spectroscopies

    Energy Technology Data Exchange (ETDEWEB)

    López-Escalante, M.C., E-mail: mclopez@uma.es [Nanotech Unit, Laboratorio de Materiales y Superficies, Departamento de Ingeniería Química, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga (Spain); Gabás, M. [The Nanotech Unit, Depto. de Física Aplicada I, Andalucía Tech, Universidad de Málaga, Campus de Teatinos s/n, 29071 Málaga Spain (Spain); García, I.; Barrigón, E.; Rey-Stolle, I.; Algora, C. [Instituto de Energía Solar, Universidad Politécnica de Madrid, Avda. Complutense 30, 28040 Madrid Spain (Spain); Palanco, S.; Ramos-Barrado, J.R. [The Nanotech Unit, Depto. de Física Aplicada I, Andalucía Tech, Universidad de Málaga, Campus de Teatinos s/n, 29071 Málaga Spain (Spain)

    2016-01-01

    Graphical abstract: - Highlights: • GaAs, AlInP and GaInP epi-layers grown in a MOVPE facility. • GaAs/GaInP and GaAs/AlInP interfaces studied through the combination of angle resolved and depth profile X-ray photoelectros spectroscopies. • GaAs/GaInP interface shows no features appart from GaAs, GaInP and mixed GaInAs or GaInAsP phases. • GaAs/AlInP interface shows traces of an anomalous P environment, probably due to P-P clusters. - Abstract: GaAs/GaInP and GaAs/AlInP interfaces have been studied using photoelectron spectroscopy tools. The combination of depth profile through Ar{sup +} sputtering and angle resolved X-ray photoelectron spectroscopy provides reliable information on the evolution of the interface chemistry. Measurement artifacts related to each particular technique can be ruled out on the basis of the results obtained with the other technique. GaAs/GaInP interface spreads out over a shorter length than GaAs/AlInP interface. The former could include the presence of the quaternary GaInAsP in addition to the nominal GaAs and GaInP layers. On the contrary, the GaAs/AlInP interface exhibits a higher degree of compound mixture. Namely, traces of P atoms in a chemical environment different to the usual AlInP coordination were found at the top of the GaAs/AlInP interface, as well as mixed phases like AlInP, GaInAsP or AlGaInAsP, located at the interface.

  8. Profiles of plasma parameters and density of negative hydrogen ions by laser detachment measurements in RF-driven ion sources; Profile der Plasmaparameter und Dichte negativer Wasserstoffionen mittels Laserdetachmentmessungen in HF-angeregten Ionenquellen

    Energy Technology Data Exchange (ETDEWEB)

    Christ-Koch, Sina

    2007-12-20

    This work shows the application of the Laserdetachment method for spatially resolved measurements of negative Hydrogen/Deuterium ion density. It was applied on a high power low pressure RF-driven ion source. The Laser detachment method is based on the measurement of electron currents on a positively biased Langmuir probe before and during/after a laser pulse. The density ratio of negative ions to electrons can be derived from the ratio of currents to the probe. The absolute density of negative ions can be obtained when the electron density is measured with the standard Langmuir probe setup. Measurements with the Langmuir probe additionally yield information about the floating and plasma potential, the electron temperature and the density of positive ions. The Laser detachment setup had to be adapted to the special conditions of the RF-driven source. In particular the existence of RF fields (1 MHz), high source potential (-20 kV), magnetic fields ({proportional_to} 7 mT) and caesium inside the source had to be considered. The density of negative ions could be identified in the range of n(H{sup -})=1.10{sup 17} 1/m{sup 3}, which is in the same order of magnitude as the electron density. Only the application of the Laser detachment method with the Langmuir probe measurements will yield spatially resolved plasma parameters and H- density profiles. The influence of diverse external parameters, such as pressure, RF-power, magnetic fields on the plasma parameters and their profiles were studied and explained. Hence, the measurements lead to a detailed understanding of the processes inside the source. (orig.)

  9. Titanite petrochronology of ultrahigh-temperature (UHT) calc-silicates from southern Madagascar: laser-ablation split-stream ICP-MS spot analyses, depth profiles, and quantified trace-element x-ray maps

    Science.gov (United States)

    Holder, Robert; Hacker, Bradley

    2017-04-01

    Calc-silicate rocks are often overlooked as sources of pressure-temperature-time data in granulite-UHT metamorphic terranes due to the strong dependence of calc-silicate mineral assemblages on complex fluid compositions, as well as a lack of thermodynamic data on common high-temperature calc-silicate minerals such as scapolite. In the Ediacaran-Cambrian UHT rocks of southern Madagascar, clinopyroxene-scapolite-feldspar-quartz-titanite calc-silicate rocks are wide-spread. U-Pb dates of c. 540-520 Ma from unaltered portions of titanite correspond to cooling of the rocks through upper-amphibolite facies and indicate UHT metamorphism occurred before 540 Ma. Zr concentrations in these domains preserve growth temperatures of 900-950 C, consistent with peak temperatures calculated by pseudosection modeling of nearby pelitic rocks. Younger U-Pb dates (c. 510-490 Ma) correspond to fluid-mediated Pb loss from titanite grains, which occurred below their diffusive Pb-closure temperature, along fractures. The extent of fluid alteration is seen clearly in back-scattered electron images as well as Zr-, Al-, Fe-, Ce-, and Nb-concentration maps. Laser-ablation depth profiling of idioblastic titanite grains shows preserved Pb diffusion profiles at grain rims, but there is no evidence for Zr diffusion, indicating that it was effectively immobile even at UHT.

  10. Hydrogen sensor

    Science.gov (United States)

    Duan, Yixiang; Jia, Quanxi; Cao, Wenqing

    2010-11-23

    A hydrogen sensor for detecting/quantitating hydrogen and hydrogen isotopes includes a sampling line and a microplasma generator that excites hydrogen from a gas sample and produces light emission from excited hydrogen. A power supply provides power to the microplasma generator, and a spectrometer generates an emission spectrum from the light emission. A programmable computer is adapted for determining whether or not the gas sample includes hydrogen, and for quantitating the amount of hydrogen and/or hydrogen isotopes are present in the gas sample.

  11. SIMS depth profiling of working environment nanoparticles

    Science.gov (United States)

    Konarski, P.; Iwanejko, I.; Mierzejewska, A.

    2003-01-01

    Morphology of working environment nanoparticles was analyzed using sample rotation technique in secondary ion mass spectrometry (SIMS). The particles were collected with nine-stage vacuum impactor during gas tungsten arc welding (GTAW) process of stainless steel and shielded metal arc welding (SMAW) of mild steel. Ion erosion of 300-400 nm diameter nanoparticles attached to indium substrate was performed with 2 keV, 100 μm diameter, Ar + ion beam at 45° ion incidence and 1 rpm sample rotation. The results show that both types of particles have core-shell morphology. A layer of fluorine, chlorine and carbon containing compounds covers stainless steel welding fume particles. The cores of these particles are enriched in iron, manganese and chromium. Outer shell of mild steel welding fume particles is enriched in carbon, potassium, chlorine and fluorine, while the deeper layers of these nanoparticles are richer in main steel components.

  12. In-Depth Two-Year Study of Phenolic Profile Variability among Olive Oils from Autochthonous and Mediterranean Varieties in Morocco, as Revealed by a LC-MS Chemometric Profiling Approach

    Directory of Open Access Journals (Sweden)

    Aadil Bajoub

    2016-12-01

    Full Text Available Olive oil phenolic fraction considerably contributes to the sensory quality and nutritional value of this foodstuff. Herein, the phenolic fraction of 203 olive oil samples extracted from fruits of four autochthonous Moroccan cultivars (“Picholine Marocaine”, “Dahbia”, “Haouzia” and “Menara”, and nine Mediterranean varieties recently introduced in Morocco (“Arbequina”, “Arbosana”, “Cornicabra”, “Frantoio”, “Hojiblanca”, “Koroneiki”, “Manzanilla”, “Picholine de Languedoc” and “Picual”, were explored over two consecutive crop seasons (2012/2013 and 2013/2014 by using liquid chromatography-mass spectrometry. A total of 32 phenolic compounds (and quinic acid, belonging to five chemical classes (secoiridoids, simple phenols, flavonoids, lignans and phenolic acids were identified and quantified. Phenolic profiling revealed that the determined phenolic compounds showed variety-dependent levels, being, at the same time, significantly affected by the crop season. Moreover, based on the obtained phenolic composition and chemometric linear discriminant analysis, statistical models were obtained allowing a very satisfactory classification and prediction of the varietal origin of the studied oils.

  13. Hydrogen storage properties on mechanically milled graphite

    OpenAIRE

    Ichikawa, Takayuki; Chen, D. M.; Isobe, Shigehito; Gomibuchi, Emi; Fujii, Hironobu

    2004-01-01

    We investigated hydrogen absorption/desorption and structural properties in mechanically milled graphite under hydrogen pressures up to 6 MPa to clarify catalytic and hydrogen pressure effects in the milling. The results indicate that a small amount of iron contamination during milling plays a quite important role as a catalyst for hydrogen absorption/desorption properties in graphite. Two-peak structure for hydrogen desorption in the TDS profile is due to existence of two different occupatio...

  14. Depth profiles of resistivity and spectral IP for active modern submarine hydrothermal deposits: a case study from the Iheya North Knoll and the Iheya Minor Ridge in Okinawa Trough, Japan

    Science.gov (United States)

    Komori, Shogo; Masaki, Yuka; Tanikawa, Wataru; Torimoto, Junji; Ohta, Yusuke; Makio, Masato; Maeda, Lena; Ishibashi, Jun-ichiro; Nozaki, Tatsuo; Tadai, Osamu; Kumagai, Hidenori

    2017-08-01

    Submarine hydrothermal deposits are one of the promising seafloor mineral resources, because they can store a large amount of metallic minerals as sulfides. The present study focuses on the electrical properties of active modern submarine hydrothermal deposits, in order to provide constraints on the interpretation of electrical structures obtained from marine electromagnetic surveys. Measurements of resistivity and spectral induced polarization (IP) were made using drillcore samples taken from the Iheya North Knoll and the Iheya Minor Ridge in Okinawa Trough, Japan. These hydrothermal sediments are dominantly composed of disseminated sulfides, with minor amounts of massive sulfide rocks. The depth profiles of resistivity and spectral IP properties were successfully revealed to correspond well to layer-by-layer lithological features. Comparison with other physical properties and occurrence of constituent minerals showed that resistivity is essentially sensitive to the connectivity of interstitial fluids, rather than by sulfide and clay content. This suggests that, in active modern submarine hydrothermal systems, not only typical massive sulfide rocks but also high-temperature hydrothermal fluids could be imaged as low-resistivity anomalies in seabed surveys. The spectral IP signature was shown to be sensitive to the presence or absence of sulfide minerals, and total chargeability is positively correlated with sulfide mineral abundance. In addition, the massive sulfide rock exhibits the distinctive IP feature that the phase steadily increases with a decrease of frequency. These results show the effective usage of IP for developing and improving marine IP exploration techniques.[Figure not available: see fulltext.

  15. Comparative study of the X-ray reflectivity and in-depth profile of a-C, B₄C and Ni coatings at 0.1-2 keV.

    Science.gov (United States)

    Kozhevnikov, I V; Filatova, E O; Sokolov, A A; Konashuk, A S; Siewert, F; Störmer, M; Gaudin, J; Keitel, B; Samoylova, L; Sinn, H

    2015-03-01

    The use of soft X-rays near the carbon edge of absorption (270-300 eV) greatly enhances studies in various branches of science. However, the choice of reflecting coatings for mirrors operating in free-electron and X-ray free-electron laser (FEL and XFEL) beamlines in this spectral range is not so evident and experimental justifications of the mirror efficiency are rather limited. In the present paper it is demonstrated experimentally that the reflectivity of B4C- and Ni-coated grazing-incidence mirrors is high enough for their operation in FEL or XFEL beamlines near the carbon K-edge of absorption. The minimal reflectivity of both mirrors proves to exceed 80% near the carbon absorption edge at a grazing angle of 0.6°. An in-depth profile of the chemical elements composing the reflecting coatings is reconstructed based on analysis of a set of reflectivity curves measured versus the grazing angle at different photon energies in the soft X-ray spectral region. This allows us to predict correctly the mirror reflectivity at any X-ray energy and any grazing angle.

  16. Depth profiling of fluorine-doped diamond-like carbon (F-DLC) film: Localized fluorine in the top-most thin layer can enhance the non-thrombogenic properties of F-DLC

    Energy Technology Data Exchange (ETDEWEB)

    Hasebe, Terumitsu [Center for Science of Environment, Resources and Energy, Keio University Faculty of Science and Technology, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522 (Japan); Department of Radiology, Tachikawa Hospital, 4-2-22, Nishiki-cho, Tachikawa, Tokyo 190-8531 (Japan)], E-mail: teru_hasebe@hotmail.com; Nagashima, So [Center for Science of Environment, Resources and Energy, Keio University Faculty of Science and Technology, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522 (Japan); Kamijo, Aki [Department of Transfusion Medicine, the University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 (Japan); Yoshimura, Taichi; Ishimaru, Tetsuya; Yoshimoto, Yukihiro; Yohena, Satoshi; Kodama, Hideyuki; Hotta, Atsushi [Center for Science of Environment, Resources and Energy, Keio University Faculty of Science and Technology, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522 (Japan); Takahashi, Koki [Department of Transfusion Medicine, the University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 (Japan); Suzuki, Tetsuya [Center for Science of Environment, Resources and Energy, Keio University Faculty of Science and Technology, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522 (Japan)

    2007-12-03

    Fluorine-doped diamond-like carbon (F-DLC) has recently drawn a great deal of attention as a more non-thrombogenic coating than conventional DLC for blood-contacting medical devices. We conducted quantitative depth profiling of F-DLC film by X-ray photoelectron spectroscopy (XPS) in order to elucidate the effects of fluorine and fluorine distribution in F-DLC film in connection with the prevention of surface blood adhesion. F-DLC films were prepared on silicon substrates using the radio frequency plasma enhanced chemical vapor deposition method, and the thickness of films was {approx} 50 nm. 50-nm-thick F-DLC film samples were etched at 10-nm thickness intervals using argon plasma, and each surface was examined by XPS. Thereafter, each etched film layer was incubated with platelet-rich plasma isolated from human whole blood, and the platelet-covered area per unit area was evaluated for each surface. XPS spectra showed the localization of doped fluorine in the top-most thin layer of the film. Platelet-covered areas represented progressively larger portions of the surfaces of deeper etched layers, corresponding to the decreasing fluorine content in such sample surfaces. These results indicate that the localized fluorine in the top-most thin layer is one of the key factors in the promotion of the non-thrombogenicity of F-DLC film.

  17. Near-surface hydrogen depletion of diamond-like carbon films produced by direct ion deposition

    Energy Technology Data Exchange (ETDEWEB)

    Markwitz, Andreas, E-mail: A.Markwitz@gns.cri.nz [GNS Science, Lower Hutt (New Zealand); The MacDiarmid Institute for Advanced Materials and Nanotechnology (New Zealand); Gupta, Prasanth [GNS Science, Lower Hutt (New Zealand); The MacDiarmid Institute for Advanced Materials and Nanotechnology (New Zealand); Mohr, Berit [GNS Science, Lower Hutt (New Zealand); Hübner, René [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf (Germany); Leveneur, Jerome; Zondervan, Albert [GNS Science, Lower Hutt (New Zealand); Becker, Hans-Werner [RUBION, Ruhr-University Bochum (Germany)

    2016-03-15

    Amorphous atomically flat diamond-like carbon (DLC) coatings were produced by direct ion deposition using a system based on a Penning ion source, butane precursor gas and post acceleration. Hydrogen depth profiles of the DLC coatings were measured with the 15N R-NRA method using the resonant nuclear reaction {sup 1}H({sup 15}N, αγ){sup 12}C (E{sub res} = 6.385 MeV). The films produced at 3.0–10.5 kV acceleration voltage show two main effects. First, compared to average elemental composition of the film, the near-surface region is hydrogen depleted. The increase of the hydrogen concentration by 3% from the near-surface region towards the bulk is attributed to a growth model which favours the formation of sp{sup 2} hybridised carbon rich films in the film formation zone. Secondly, the depth at which the maximum hydrogen concentration is measured increases with acceleration voltage and is proportional to the penetration depth of protons produced by the ion source from the precursor gas. The observed effects are explained by a deposition process that takes into account the contributions of ion species, hydrogen effusion and preferential displacement of atoms during direct ion deposition.

  18. SIMS and TEM investigation of hydrogen trapping on implantation defects in a nickel-based superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Jambon, Fanny, E-mail: fanny.jambon@cea.fr [CEA, DEN, DPC, SCCME, Laboratoire d' Étude de la Corrosion Aqueuse, F-91191 Gif-Sur-Yvette Cedex (France); Marchetti, Loïc [CEA, DEN, DPC, SCCME, Laboratoire d' Étude de la Corrosion Aqueuse, F-91191 Gif-Sur-Yvette Cedex (France); CEA, DEN, DTCD, SECM, Laboratoire d' étude du Comportement à Long Terme des Matériaux de conditionnement, F-30207 Bagnols-sur-Cèze (France); Sennour, Mohamed [MINES ParisTech, PSL – Research University – Centre des Matériaux, UMR CNRS 7633, B.P. 87, 91003 Evry (France); Jomard, François [Groupe d' Etude de la Matière Condensée (CNRS and University of Versailles Saint Quentin), 45 avenue des Etats-Unis, 78035 Versailles Cedex (France); Chêne, Jacques [UMR 8587 CEA/CNRS, Équipe Hydrogène/Matériaux de structure, CEA, DEN, DPC, SCCME, Laboratoire d' Étude de la Corrosion Aqueuse, F-91191 Gif-Sur-Yvette Cedex (France)

    2015-11-15

    This study aims at characterizing the interactions of hydrogen with point defects and their clusters in nickel-based superalloys. For this, nickel ion implantation was used to create defects in the sub-surface of alloy 690 coupons. The interaction of hydrogen with these defects was studied thanks to SIMS depth profile analysis performed after deuterium cathodic charging, and different annealing treatment. In parallel, TEM observations were carried out in order to qualify and quantify the defects responsible for the trapping, and to observe their evolution in the presence of hydrogen. All the results exhibit a strong interaction of hydrogen with implantation-defects, up to high temperatures (325 °C). Also, hydrogen is shown to assist defects reorganisation, in a way similar to the effect of temperature. The effect of hydrogen on the alloy atoms as explored by SIMS, combined with the TEM investigation of defects evolution in the presence of hydrogen, allows to suggest that the main mechanism for hydrogen-assisted motion of defects is by lowering the lattice friction, thus decreasing the activation volume for the unfaulting or motion of point defect clusters, up to dislocation loops.

  19. Liquid Organic Hydrogen Carriers (LOHCs): Toward a Hydrogen-free Hydrogen Economy.

    Science.gov (United States)

    Preuster, Patrick; Papp, Christian; Wasserscheid, Peter

    2017-01-17

    The need to drastically reduce CO 2 emissions will lead to the transformation of our current, carbon-based energy system to a more sustainable, renewable-based one. In this process, hydrogen will gain increasing importance as secondary energy vector. Energy storage requirements on the TWh scale (to bridge extended times of low wind and sun harvest) and global logistics of renewable energy equivalents will create additional driving forces toward a future hydrogen economy. However, the nature of hydrogen requires dedicated infrastructures, and this has prevented so far the introduction of elemental hydrogen into the energy sector to a large extent. Recent scientific and technological progress in handling hydrogen in chemically bound form as liquid organic hydrogen carrier (LOHC) supports the technological vision that a future hydrogen economy may work without handling large amounts of elemental hydrogen. LOHC systems are composed of pairs of hydrogen-lean and hydrogen-rich organic compounds that store hydrogen by repeated catalytic hydrogenation and dehydrogenation cycles. While hydrogen handling in the form of LOHCs allows for using the existing infrastructure for fuels, it also builds on the existing public confidence in dealing with liquid energy carriers. In contrast to hydrogen storage by hydrogenation of gases, such as CO 2 or N 2 , hydrogen release from LOHC systems produces pure hydrogen after condensation of the high-boiling carrier compounds. This Account highlights the current state-of-the-art in hydrogen storage using LOHC systems. It first introduces fundamental aspects of a future hydrogen economy and derives therefrom requirements for suitable LOHC compounds. Molecular structures that have been successfully applied in the literature are presented, and their property profiles are discussed. Fundamental and applied aspects of the involved hydrogenation and dehydrogenation catalysis are discussed, characteristic differences for the catalytic conversion of

  20. Hydrogen Generator

    Science.gov (United States)

    1983-01-01

    A unit for producing hydrogen on site is used by a New Jersey Electric Company. The hydrogen is used as a coolant for the station's large generator; on-site production eliminates the need for weekly hydrogen deliveries. High purity hydrogen is generated by water electrolysis. The electrolyte is solid plastic and the control system is electronic. The technology was originally developed for the Gemini spacecraft.

  1. The effects of the hydrogen addition on the HCN profiles in fuel-rich-premixed, burner-stabilized C1-C3 alkane flames

    NARCIS (Netherlands)

    Sepman, A. V.; Mokhov, A. V.; Levinsky, H. B.

    2011-01-01

    The effects of hydrogen addition on HCN formation and consumption in fuel-rich, burnerstabilized methane, ethane and propane flames are reported. The HCN mole fraction was measured using quartz-microprobe sampling followed by direct absorption spectroscopy. Experiments were performed at equivalence

  2. Elastic recoil detection analysis of hydrogen in polymers

    Energy Technology Data Exchange (ETDEWEB)

    Winzell, T.R.H.; Whitlow, H.J. [Lund Univ. (Sweden); Bubb, I.F.; Short, R.; Johnston, P.N. [Royal Melbourne Inst. of Tech., VIC (Australia)

    1996-12-31

    Elastic recoil detection analysis (ERDA) of hydrogen in thick polymeric films has been performed using 2.5 MeV He{sup 2+} ions from the tandem accelerator at the Royal Melbourne Institute of Technology. The technique enables the use of the same equipment as in Rutherford backscattering analysis, but instead of detecting the incident backscattered ion, the lighter recoiled ion is detected at a small forward angle. The purpose of this work is to investigate how selected polymers react when irradiated by helium ions. The polymers are to be evaluated for their suitability as reference standards for hydrogen depth profiling. Films investigated were Du Pont`s Kapton and Mylar, and polystyrene. 11 refs., 3 figs.

  3. Computations Of Critical Depth In Rivers With Flood Plains | Okoli ...

    African Journals Online (AJOL)

    Critical flows may occur at more than one depth in rivers with flood plains. The possibility of multiple critical depths affects the water-surface profile calculations. Presently available algorithms determine only one of the critical depths which may lead to large errors. It is the purpose of this paper to present an analytical ...

  4. Hydrogen Embrittlement

    Science.gov (United States)

    Woods, Stephen; Lee, Jonathan A.

    2016-01-01

    Hydrogen embrittlement (HE) is a process resulting in a decrease in the fracture toughness or ductility of a metal due to the presence of atomic hydrogen. In addition to pure hydrogen gas as a direct source for the absorption of atomic hydrogen, the damaging effect can manifest itself from other hydrogen-containing gas species such as hydrogen sulfide (H2S), hydrogen chloride (HCl), and hydrogen bromide (HBr) environments. It has been known that H2S environment may result in a much more severe condition of embrittlement than pure hydrogen gas (H2) for certain types of alloys at similar conditions of stress and gas pressure. The reduction of fracture loads can occur at levels well below the yield strength of the material. Hydrogen embrittlement is usually manifest in terms of singular sharp cracks, in contrast to the extensive branching observed for stress corrosion cracking. The initial crack openings and the local deformation associated with crack propagation may be so small that they are difficult to detect except in special nondestructive examinations. Cracks due to HE can grow rapidly with little macroscopic evidence of mechanical deformation in materials that are normally quite ductile. This Technical Memorandum presents a comprehensive review of experimental data for the effects of gaseous Hydrogen Environment Embrittlement (HEE) for several types of metallic materials. Common material screening methods are used to rate the hydrogen degradation of mechanical properties that occur while the material is under an applied stress and exposed to gaseous hydrogen as compared to air or helium, under slow strain rates (SSR) testing. Due to the simplicity and accelerated nature of these tests, the results expressed in terms of HEE index are not intended to necessarily represent true hydrogen service environment for long-term exposure, but rather to provide a practical approach for material screening, which is a useful concept to qualitatively evaluate the severity of

  5. The role of radiation damage on retention and temperature intervals of helium and hydrogen detrapping in structural materials

    Energy Technology Data Exchange (ETDEWEB)

    Tolstolutskaya, G.D., E-mail: g.d.t@kipt.kharkov.ua [National Science Center “Kharkov Institute of Physics and Technology”, 1, Akademicheskaya St., 61108 Kharkov (Ukraine); Ruzhytskyi, V.V.; Voyevodin, V.N.; Kopanets, I.E.; Karpov, S.A.; Nikitin, A.V. [National Science Center “Kharkov Institute of Physics and Technology”, 1, Akademicheskaya St., 61108 Kharkov (Ukraine)

    2013-11-15

    An experimental study of hydrogen/deuterium behavior in ferritic–martensitic stainless steels EP-450 (Cr13Mo2NbVB), EP-852 (Cr13Mo2VS), and RUSFER-EK-181 (Fe12Cr2WVTaB) is presented. The effect of displacement damage (dpa) resulting from irradiation with helium, hydrogen, and argon ions on features of deuterium detrapping and retention in steels was studied using ion implantation, nuclear reaction depth profiling, and thermal desorption spectrometry techniques. Numerical simulation on the basis of the continuum rate theory was applied for obtaining thermodynamic parameters of deuterium trapping and desorption in steels.

  6. Program analysis and presentation of results of the profiles and depth dose rates obtained with the PTW software MC{sub 2} MEPHYSTO; Programa de analisis y presentacion de resultados de los perfiles y porcentajes de dosis en profundidad adquiridos con el software MEPHYSTO MC2 de PTW

    Energy Technology Data Exchange (ETDEWEB)

    Tato de la Cuevas, F.

    2011-07-01

    In the periodic quality control of linear accelerators is usually included acquisition and analysis of profiles and PDDs (percentage depth dose). In the protocol of Quality Control of electron accelerators for clinical use of the proposed analysis SEFM 4 Profiles for each of the energies used clinically. This involves a large number of curves to be analyzed and the subsequent introduction of the parameters in a spreadsheet or similar for your assessment as to the reference state. We have developed a program that analyzes the curves acquired by mcc Mephysto PTW software and presents the results of that analysis in a spreadsheet.

  7. Temperature profile and water depth data collected from KIDD using BT and XBT casts in the North/South Pacific Ocean from 06 August 1977 to 30 April 1990 (NODC Accession 9000141)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The water depth and temperature data was collected from thirty three different ships used for 44 cruises. The data was collected between August 6, 1987 to April 30,...

  8. Temperature profile and water depth data collected from IOWA using BT and XBT casts in the North Pacific Ocean from 31 May 1985 to 23 March 1990 (NODC Accession 9000092)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The water depth and temperature data was collected using two dozen different ships through a grant to Dr. Douglas C. Biggs MMS # 14-35-0001-30501. The data was...

  9. A DLTS study of hydrogen doped czochralski-grown silicon

    Energy Technology Data Exchange (ETDEWEB)

    Jelinek, M. [Infineon Technologies Austria AG, 9500 Villach (Austria); Laven, J.G. [Infineon Technologies AG, 81726 Munich (Germany); Kirnstoetter, S. [Institute of Solid State Physics, Graz University of Technology, 8010 Graz (Austria); Schustereder, W. [Infineon Technologies Austria AG, 9500 Villach (Austria); Schulze, H.-J. [Infineon Technologies AG, 81726 Munich (Germany); Rommel, M. [Fraunhofer Institute of Integrated Systems and Devices IISB, 91058 Erlangen (Germany); Frey, L. [Fraunhofer Institute of Integrated Systems and Devices IISB, 91058 Erlangen (Germany); Chair of Electron Devices, FAU Erlangen-Nuremberg, 91058 Erlangen (Germany)

    2015-12-15

    In this study we examine proton implanted and subsequently annealed commercially available CZ wafers with the DLTS method. Depth-resolved spreading resistance measurements are shown, indicating an additional peak in the induced doping profile, not seen in the impurity-lean FZ reference samples. The additional peak lies about 10–15 μm deeper than the main peak near the projected range of the protons. A DLTS characterization in the depth of the additional peak indicates that it is most likely not caused by classical hydrogen-related donors known also from FZ silicon but by an additional donor complex whose formation is assisted by the presence of silicon self-interstitials.

  10. Hydrogen Bibliography

    Energy Technology Data Exchange (ETDEWEB)

    1991-12-01

    The Hydrogen Bibliography is a compilation of research reports that are the result of research funded over the last fifteen years. In addition, other documents have been added. All cited reports are contained in the National Renewable Energy Laboratory (NREL) Hydrogen Program Library.

  11. Hydrogen exchange

    DEFF Research Database (Denmark)

    Jensen, Pernille Foged; Rand, Kasper Dyrberg

    2016-01-01

    Hydrogen exchange (HX) monitored by mass spectrometry (MS) is a powerful analytical method for investigation of protein conformation and dynamics. HX-MS monitors isotopic exchange of hydrogen in protein backbone amides and thus serves as a sensitive method for probing protein conformation...... and dynamics along the entire protein backbone. This chapter describes the exchange of backbone amide hydrogen which is highly quenchable as it is strongly dependent on the pH and temperature. The HX rates of backbone amide hydrogen are sensitive and very useful probes of protein conformation......, as they are distributed along the polypeptide backbone and form the fundamental hydrogen-bonding networks of basic secondary structure. The effect of pressure on HX in unstructured polypeptides (poly-dl-lysine and oxidatively unfolded ribonuclease A) and native folded proteins (lysozyme and ribonuclease A) was evaluated...

  12. California Hydrogen Infrastructure Project

    Energy Technology Data Exchange (ETDEWEB)

    Heydorn, Edward C

    2013-03-12

    Air Products and Chemicals, Inc. has completed a comprehensive, multiyear project to demonstrate a hydrogen infrastructure in California. The specific primary objective of the project was to demonstrate a model of a real-world retail hydrogen infrastructure and acquire sufficient data within the project to assess the feasibility of achieving the nation's hydrogen infrastructure goals. The project helped to advance hydrogen station technology, including the vehicle-to-station fueling interface, through consumer experiences and feedback. By encompassing a variety of fuel cell vehicles, customer profiles and fueling experiences, this project was able to obtain a complete portrait of real market needs. The project also opened its stations to other qualified vehicle providers at the appropriate time to promote widespread use and gain even broader public understanding of a hydrogen infrastructure. The project engaged major energy companies to provide a fueling experience similar to traditional gasoline station sites to foster public acceptance of hydrogen. Work over the course of the project was focused in multiple areas. With respect to the equipment needed, technical design specifications (including both safety and operational considerations) were written, reviewed, and finalized. After finalizing individual equipment designs, complete station designs were started including process flow diagrams and systems safety reviews. Material quotes were obtained, and in some cases, depending on the project status and the lead time, equipment was placed on order and fabrication began. Consideration was given for expected vehicle usage and station capacity, standard features needed, and the ability to upgrade the station at a later date. In parallel with work on the equipment, discussions were started with various vehicle manufacturers to identify vehicle demand (short- and long-term needs). Discussions included identifying potential areas most suited for hydrogen fueling

  13. Hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Donath, E.

    1942-10-16

    This report mentioned that not very severe demands for purity were made on the hydrogen used in hydrogenation of coal or similar raw materials, because the catalysts were not very sensitive to poisoning. However, the hydrogenation plants tried to remove most impurities anyway by means of oil washes. The report included a table giving the amount of wash oil used up and the amount of hydrogen lost by dissolving into the wash oil used up and the amount of hydrogen lost by dissolving into the wash oil in order to remove 1% of various impurities from 1000 m/sup 3/ of the circulating gas. The amounts of wash oil used up were 1.1 m/sup 3/ for removing 1% nitrogen, 0.3 m/sup 3/ for 1% carbon monoxide, 0.03 m/sup 3/ for 1% methane. The amount of hydrogen lost was 28 m/sup 3/ for 1% nitrogen, 9 m/sup 3/ for 1% methane and ranged from 9 m/sup 3/ to 39 m/sup 3/ for 1% carbon monoxide and 1 m/sup 3/ to 41 m/sup 3/ for carbon dioxide depending on whether the removal was done in liquid phase or vapor phase and with or without reduction of the oxide to methane. Next the report listed and described the major processes used in German hydrogenation plants to produce hydrogen. Most of them produced water gas, which then had its carbon monoxide changed to carbon dioxide, and the carbon oxides washed out with water under pressure and copper hydroxide solution. The methods included the Winkler, Pintsch-Hillebrand, and Schmalfeldt-Wintershall processes, as well as roasting of coke in a rotating generator, splitting of gases formed during hydrogenation, and separation of cokery gas into its components by the Linde process.

  14. CRED Ocean Data Platform (ODP), Acoustic Doppler Profiler (ADP); PRIA, BAK; Long: -176.46012, Lat: 00.18994 (WGS84); Sensor Depth: 19.81m; Data Range: 20080210-20100130.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  15. CRED Ocean Data Platform (ODP), Acoustic Doppler Profiler (ADP); AMSM, SWA; Long: -171.09092, Lat: -11.05848 (WGS84); Sensor Depth: 15.00m; Data Range: 20020227-20021207.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  16. CRED Ocean Data Platform (ODP), Acoustic Doppler Profiler (ADP); NWHI, PHR; Long: -175.88110, Lat: 27.78209 (WGS84); Sensor Depth: 21.34m; Data Range: 20070806-20070912.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  17. CRED Ocean Data Platform (ODP), Acoustic Doppler Profiler (ADP); PRIA, BAK; Long: -176.46025, Lat: 00.19005 (WGS84); Sensor Depth: 18.90m; Data Range: 20020201-20040122.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  18. CRED Ocean Data Platform (ODP), Acoustic Doppler Profiler (ADP); PRIA, BAK; Long: -176.46012, Lat: 00.18994 (WGS84); Sensor Depth: 18.80m; Data Range: 20060131-20080209.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  19. CRED Ocean Data Platform (ODP), Acoustic Doppler Profiler (ADP); PRIA, BAK; Long: -176.46025, Lat: 00.19005 (WGS84); Sensor Depth: 18.90m; Data Range: 20040123-20060130.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  20. CRED Ocean Data Platform (ODP), Acoustic Doppler Profiler (ADP); NWHI, PHR; Long: -175.88112, Lat: 27.78204 (WGS84); Sensor Depth: 21.34m; Data Range: 20060922-20070805.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  1. CRED Ocean Data Platform (ODP), Acoustic Doppler Profiler (ADP); MHI, KAU; Long: -159.51350, Lat: 22.21593 (WGS84); Sensor Depth: 15.24m; Data Range: 20060914-20070420.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  2. CRED Ocean Data Platform (ODP), Acoustic Doppler Profiler (ADP); NWHI, NEC; Long: -164.71215, Lat: 23.56792 (WGS84); Sensor Depth: 24.90m; Data Range: 20050411-20060903.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  3. CRED Ocean Data Platform (ODP), Acoustic Doppler Profiler (ADP); Guam, SRR; Long: 144.41784, Lat: 12.83819 (WGS84); Sensor Depth: 20.40m; Data Range: 20030929-20050908.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  4. CRED Ocean Data Platform (ODP), Acoustic Doppler Profiler (ADP); Guam, SRR; Long: 144.41778, Lat: 12.83819 (WGS84); Sensor Depth: 20.42m; Data Range: 20051007-20070121.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  5. CRED Ocean Data Platform (ODP), Acoustic Doppler Profiler (ADP); PRIA, JAR; Long: -160.01547, Lat: -00.37915 (WGS84); Sensor Depth: 14.60m; Data Range: 20040327-20051016.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  6. CRED Ocean Data Platform (ODP), Acoustic Doppler Profiler (ADP); NWHI, MID; Long: -177.42977, Lat: 28.23180 (WGS84); Sensor Depth: 29.26m; Data Range: 20060916-20080928.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  7. CRED Ocean Data Platform (ODP), Acoustic Doppler Profiler (ADP); PRIA, JAR; Long: -160.01553, Lat: -00.37917 (WGS84); Sensor Depth: 15.00m; Data Range: 20020311-20040325.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  8. Effect of hydrogen uptake on the electrochemical corrosion of N18 zircaloy under gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Xin, Z.Y. [Lab of Advanced Materials, School of Materials Sciences and Engineering, Tsinghua University, Beijing 100084 (China); Ling, Y.H., E-mail: yhling@mail.tsinghua.edu.cn [Lab of Advanced Materials, School of Materials Sciences and Engineering, Tsinghua University, Beijing 100084 (China); Bai, Y.K.; Zeng, C.; Wang, S. [Lab of Advanced Materials, School of Materials Sciences and Engineering, Tsinghua University, Beijing 100084 (China); Clara, J.C. [Department of Chemistry, University of Western Ontario, London N6A 5B7, Ontario (Canada)

    2016-12-01

    Highlights: • Hydrogen permeation can promote the corrosion rate of N18 zircaloy. • Gamma irradiation can further accelerate the corrosion process. • A novel mechanism based on point defects was proposed to explain the relevant phenomena. - Abstract: It has been well recognized that dramatic hydrogen uptake occurred in zircaloy after kinetic transition and porous structure was observed subsequently due to phase transformation of tetragonal to monoclinic zirconia. Therefore, how hydrogen solute and gamma-induced capillary-embedded hydrolysis influence the corrosion of zircaloy is an intriguing issue. In this work, the effect of hydrogen uptake and gamma irradiation on corrosion of N18 zircaloy was studied. Raman spectra and atomic force microscopy (AFM) were employed to analyse phase structure and surface morphology. Potentiodynamic polarization and electrochemical impedance spectroscopy were utilized to qualitatively evaluate the electron transfer properties of the oxide film formed on the zircaloy surface after corrosion. The depth profile and surface chemical states of involving elements were analysed by auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS), respectively. It was found that hydrogen permeation can decline the integrity and impedance semicircle of the oxide films, the more the hydrogen uptake is; the smaller magnitude of impedance will be. In view of the gamma irradiation, it is demonstrated that it promotes the corrosion rate slightly. Based on the irradiation theory and existing phenomena, the underlying mechanism is proposed.

  9. Acute Lethality of Inhaled Hydrogen Cyanide in the Laboratory Rat: Impact of Concentration x Time Profile and Evaluation of the Predictivity of Toxic Load Models

    Science.gov (United States)

    2013-05-03

    8239 (7287-9191) ppm-minutes. Table 12. Dose-Response Data for Profile 8 Concentration (ppm) Cavg × t (ppm-min.) Lethality 255.0/50.6 4584 1...p = 0.1901 8239 (7287-9191) 9 p = 0.2451 7597 (6402-8792) 10 b p = 0.1297 7498 (6875-8121) 15 minutes 11 p = 0.6830 6425 (5759-7090) a 95

  10. Modeled Daily Thaw Depth and Frozen Ground Depth, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains modeled daily thaw depth and freezing depth for the Arctic terrestrial drainage basin. Thaw and freezing depths were calculated over the study...

  11. Depth of maximum of air-shower profiles at the Pierre Auger Observatory. I. Measurements at energies above 10.sup.17.8./sup.  eV

    Czech Academy of Sciences Publication Activity Database

    Aab, A.; Abreu, P.; Aglietta, M.; Boháčová, Martina; Chudoba, Jiří; Ebr, Jan; Mandát, Dušan; Nečesal, Petr; Palatka, Miroslav; Pech, Miroslav; Prouza, Michael; Řídký, Jan; Schovánek, Petr; Trávníček, Petr; Vícha, Jakub

    2014-01-01

    Roč. 90, č. 12 (2014), "122005-1"-"122005-25" ISSN 1550-7998 R&D Projects: GA MŠk(CZ) 7AMB14AR005; GA MŠk(CZ) LG13007; GA ČR(CZ) GA14-17501S Institutional support: RVO:68378271 Keywords : astroparticle physics * Pierre Auger Observatory * cosmic rays * air showers * depth of maximum * Xmax Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 4.643, year: 2014

  12. Electrical characteristics and hydrogen concentration of chemical vapor deposited silicon dioxide films: Effect of water treatment

    Science.gov (United States)

    Li, S. C.; Murarka, S. P.

    1992-11-01

    The effect of exposing chemical vapor deposited silicon dioxide directly to water has been investigated. Unlike the effect of the water-related traps in thermally grown silicon dioxide, the capacitance-voltage (C-V) shift due to diffused-in water molecules is directly observed without using the method of avalanche injection. The resonate nuclear reaction technique with 15N ion beam has been used to measure the hydrogen concentration of water-boiled, as-deposited, and rapid thermal-annealed silicon dioxide films. These depth profiles show that the hydrogen-containing species, that are most likely water molecules, diffuse in and out and redistribute in the as-deposited and rapid thermal-annealed films. These hydrogen depth profiles also indicate that the amount of diffused-in water molecules in the oxide is limited by the solubility of the water in the oxide. The solubility of water in the oxide annealed at high temperatures is found to be significantly lower than that in the as-deposited oxide. It is found that diffused-in water molecules, in order to satisfy the water solubility of the oxide, play a compensating role in controlling the oxide charges. Water molecules would continue to diffuse in, and interact with oxide charges and produce charges with reverse polarity that compensate the existing oxide charges until water solubility is satisfied.

  13. Black silicon method X: a review on high speed and selective plasma etching of silicon with profile control: an in-depth comparison between Bosch and cryostat DRIE processes as a roadmap to next generation equipment

    NARCIS (Netherlands)

    Jansen, Henricus V.; de Boer, Meint J.; Unnikrishnan, S.; Louwerse, M.C.; Elwenspoek, Michael Curt

    An intensive study has been performed to understand and tune deep reactive ion etch (DRIE) processes for optimum results with respect to the silicon etch rate, etch profile and mask etch selectivity (in order of priority) using state-of-the-art dual power source DRIE equipment. The research compares

  14. Hydrologic regulation of plant rooting depth

    Science.gov (United States)

    Fan, Ying; Miguez-Macho, Gonzalo; Jobbágy, Esteban G.; Jackson, Robert B.; Otero-Casal, Carlos

    2017-10-01

    Plant rooting depth affects ecosystem resilience to environmental stress such as drought. Deep roots connect deep soil/groundwater to the atmosphere, thus influencing the hydrologic cycle and climate. Deep roots enhance bedrock weathering, thus regulating the long-term carbon cycle. However, we know little about how deep roots go and why. Here, we present a global synthesis of 2,200 root observations of >1,000 species along biotic (life form, genus) and abiotic (precipitation, soil, drainage) gradients. Results reveal strong sensitivities of rooting depth to local soil water profiles determined by precipitation infiltration depth from the top (reflecting climate and soil), and groundwater table depth from below (reflecting topography-driven land drainage). In well-drained uplands, rooting depth follows infiltration depth; in waterlogged lowlands, roots stay shallow, avoiding oxygen stress below the water table; in between, high productivity and drought can send roots many meters down to the groundwater capillary fringe. This framework explains the contrasting rooting depths observed under the same climate for the same species but at distinct topographic positions. We assess the global significance of these hydrologic mechanisms by estimating root water-uptake depths using an inverse model, based on observed productivity and atmosphere, at 30″ (˜1-km) global grids to capture the topography critical to soil hydrology. The resulting patterns of plant rooting depth bear a strong topographic and hydrologic signature at landscape to global scales. They underscore a fundamental plant-water feedback pathway that may be critical to understanding plant-mediated global change.

  15. Reference depth for geostrophic computation - A new method

    Digital Repository Service at National Institute of Oceanography (India)

    Varkey, M.J.; Sastry, J.S.

    Various methods are available for the determination of reference depth for geostrophic computation. A new method based on the vertical profiles of mean and variance of the differences of mean specific volume anomaly (delta x 10) for different layers...

  16. Hydrogen program overview

    Energy Technology Data Exchange (ETDEWEB)

    Gronich, S. [Dept. of Energy, Washington, DC (United States). Office of Utility Technologies

    1997-12-31

    This paper consists of viewgraphs which summarize the following: Hydrogen program structure; Goals for hydrogen production research; Goals for hydrogen storage and utilization research; Technology validation; DOE technology validation activities supporting hydrogen pathways; Near-term opportunities for hydrogen; Market for hydrogen; and List of solicitation awards. It is concluded that a full transition toward a hydrogen economy can begin in the next decade.

  17. Using "residual depths" to monitor pool depths independently of discharge

    Science.gov (United States)

    Thomas E. Lisle

    1987-01-01

    As vital components of habitat for stream fishes, pools are often monitored to follow the effects of enhancement projects and natural stream processes. Variations of water depth with discharge, however, can complicate monitoring changes in the depth and volume of pools. To subtract the effect of discharge on depth in pools, residual depths can be measured. Residual...

  18. Hydrogen usage

    Energy Technology Data Exchange (ETDEWEB)

    1942-10-22

    This short tabular report listed the number of m/sup 3/ of hydrogen required for a (metric) ton of product for various combinations of raw material and product in a hydrogenation procedure. In producing auto gasoline, bituminous coal required 2800 m/sup 3/, brown coal required 2400 m/sup 3/, high-temperature-carbonization tar required 2100 m/sup 3/, bituminous coal distillation tar required 1300 m/sup 3/, brown-coal low-temperature-carbonization tar required 850 m/sup 3/, petroleum residues required 900 m/sup 3/, and gas oil required 500 m/sup 3/. In producing diesel oil, brown coal required 1900 m/sup 3/, whereas petroleum residues required 500 m/sup 3/. In producing diesel oil, lubricants, and paraffin by the TTH (low-temperature-hydrogenation) process, brown-coal low-temperature-carbonization tar required 550 m/sup 3/. 1 table.

  19. DEPTH: a web server to compute depth and predict small-molecule binding cavities in proteins.

    Science.gov (United States)

    Tan, Kuan Pern; Varadarajan, Raghavan; Madhusudhan, M S

    2011-07-01

    Depth measures the extent of atom/residue burial within a protein. It correlates with properties such as protein stability, hydrogen exchange rate, protein-protein interaction hot spots, post-translational modification sites and sequence variability. Our server, DEPTH, accurately computes depth and solvent-accessible surface area (SASA) values. We show that depth can be used to predict small molecule ligand binding cavities in proteins. Often, some of the residues lining a ligand binding cavity are both deep and solvent exposed. Using the depth-SASA pair values for a residue, its likelihood to form part of a small molecule binding cavity is estimated. The parameters of the method were calibrated over a training set of 900 high-resolution X-ray crystal structures of single-domain proteins bound to small molecules (molecular weight download the outputs. Our server is useful for all structural analysis based on residue depth and SASA, such as guiding site-directed mutagenesis experiments and small molecule docking exercises, in the context of protein functional annotation and drug discovery.

  20. High depth resolution ERD of light elements by means of an electrostatic spectrometer for MeV ions in combination with a time of flight technique

    Science.gov (United States)

    Jamecsny, S.; Carstanjen, H. D.

    1997-02-01

    At the Max-Planck-Institut für Metallphysik in Stuttgart, Germany, a 6 MV Pelletron accelerator is being used for surface analysis using high resolution RBS and ERD of hydrogen by means of an electrostatic spectrometer. While for ERD analysis of hydrogen a thin foil in front of the detector is sufficient to eliminate the background of backscattered particles, for the ERD analysis of heavier elements, e.g., oxygen, the recording of a second parameter of the detected particles is necessary to separate particles of the same energy, but of different mass and charge state. For this purpose a set-up was installed that combines the high energy resolution of the spectrometer with a measurement of the time of flight of the ions through the spectrometer using a chopped ion beam. The measurement of depth profiles of elements lighter than argon, with a depth resolution in the few monolayer range, is now possible. The technique is demonstrated by the analysis of the oxidation of aluminum single crystal surfaces. The experiments revealed a strong anisotropy in the oxidation. The technique also allows to measure charge state dependent depth profiles. Measurements of backscattering of Ne and Ar ions on Au and of recoil O ions from Ta2O5 and Al2O3 have been performed. From the measurements charge state distributions after the ion-atom collision and mean free path lengths for electron capture and loss are derived.

  1. Versatile Hydrogen

    Indian Academy of Sciences (India)

    Hydrogen is probably the most intriguing ele- ment in the periodic table. Although it is only the seventh most abundant element on earth, it is the most abundant element in the uni- verse. It combines with almost all the ele- ments of the periodic table, except for a few transition elements, to form binary compounds of the type E.

  2. Behaviors of hydrogen in C-SiC films with IR and SIMS analyses

    CERN Document Server

    Huang, N K; Xiong, Q; Liu, Y G; Wang, D Z; Lei, J R

    2002-01-01

    C-SiC films with different content of SiC were prepared with magnetron sputtering deposition followed by Ar sup + ion bombardment. Secondary ion mass spectroscopy depth profiles of hydrogen for the samples of C-SiC coated stainless steel and stainless steel substrate after H sup + ion implantation and thermal annealing show different hydrogen concentrations in C-SiC coatings and stainless steel. Infrared (IR) transmission measurement was selected to study the mechanism of hydrogen retention by C-SiC films. The vibrational spectra in the range between 400 and 3200 cm sup - sup 1 in IR transmission spectra show the Si-CH sub 3 , Si-CH sub 2 , Si-H, CH sub 2 , CH sub 3 etc. bonds, which are responsible for retaining hydrogen. Apart from the mode above, there also exist bonds related to carbon and silicon such as Si-C, C=C. The contamination of oxygen entered the film to form C=O and SiO sub 2 configurations and hydrogen contamination also formed Si-CH sub 2 mode in the films.

  3. Absorbed doses profiles vs Synovia tissue depth for the Y-90 and P-32 used in radiosynoviortesis treatment; Perfiles de dosis absorbida vs profundidad de tejido sinovial para el Y-90 y el P-32 empleados en tratamiento de radiosinoviortesis

    Energy Technology Data Exchange (ETDEWEB)

    Torres B, M.B.; Ayra P, F.E. [Centro de Isotopos (Cuba); Garcia R, E. [Hospital General Docente Enrique Cabrera (Cuba); Cornejo D, N. [CPHR, (Cuba); Yoriyaz, H. [IPEN, (Brazil)]. e-mail: nestor@cphr.edu.cu

    2006-07-01

    The radiosynoviortesis treatment has been used during more of 40 years as an alternative to the chemical and surgical synovectomy to alleviate the pain and to reduce the inflammation in suffered patients of rheumatic arthropathies, haemophilic arthropathies and other articulation disorders. It consists on the injection of radioactive isotopes inside a synovial cavity. For to evaluate the dosimetry of the radiosynoviortesis treatment is of great interest to know the absorbed dose in the volume of the target (synovia). The precise calculation of the absorbed dose in the inflamed synovia it is difficult, for numerous reasons, since the same one will depend on the thickness of the synovial membrane, the size of the articular space, the structure of the synovial membrane, the distribution in the articulation, the nature of the articular liquid, etc. Also the presence of the bone and the articular cartilage, components also of the articulation, it even complicated more the calculations. The method used to evaluate the dosimetry in radioactive synovectomy is known as the Monte Carlo method. The objective of our work consists on estimating with the Monte Carlo code MCNP4B the absorbed dose of the Y-90 and the P-32 in the depth of the synovial tissue. The results are presented as absorbed dose for injected millicurie (Gy/mCi) versus depth of synovial tissue. The simulation one carries out keeping in mind several synovia areas, of 50 cm{sup 2} to 250 cm{sup 2} keeping in mind three states of progression of the illness. Those obtained values of absorbed dose using the MCNP4B code will allow to introduce in our country an optimized method of dose prescription to the patient, to treat the rheumatic arthritis in medium and big articulations using the Y-90 and the P-32, eliminating the fixed doses and fixed radionuclides for each articulation like it happens in many clinics of Europe, as well as the empiric doses. (Author)

  4. Colonization and community structure of arbuscular mycorrhizal fungi in maize roots at different depths in the soil profile respond differently to phosphorus inputs on a long-term experimental site.

    Science.gov (United States)

    Wang, Chao; White, Philip J; Li, Chunjian

    2017-05-01

    Effects of soil depth and plant growth stages on arbuscular mycorrhizal fungal (AMF) colonization and community structure in maize roots and their potential contribution to host plant phosphorus (P) nutrition under different P-fertilizer inputs were studied. Research was conducted on a long-term field experiment over 3 years. AMF colonization was assessed by AM colonization rate and arbuscule abundances and their potential contribution to host P nutrition by intensity of fungal alkaline phosphatase (ALP)/acid phosphatase (ACP) activities and expressions of ZmPht1;6 and ZmCCD8a in roots from the topsoil and subsoil layer at different growth stages. AMF community structure was determined by specific amplification of 18S rDNA. Increasing P inputs up to 75-100 kg ha -1  yr -1 increased shoot biomass and P content but decreased AMF colonization and interactions between AMF and roots. AM colonization rate, intensity of fungal ACP/ALP activities, and expression of ZmPht1;6 in roots from the subsoil were greater than those from topsoil at elongation and silking but not at the dough stage when plants received adequate or excessive P inputs. Neither P input nor soil depth influenced the number of AMF operational taxonomic units (OTUs) present in roots, but P-fertilizer input, in particular, influenced community composition and relative AMF abundance. In conclusion, although increasing P inputs reduce AMF colonization and influence AMF community structure, AMF can potentially contribute to plant P nutrition even in well-fertilized soils, depending on the soil layer in which roots are located and the growth stage of host plants.

  5. Interesterified fat or palm oil as substitutes for partially hydrogenated fat during the perinatal period produces changes in the brain fatty acids profile and increases leukocyte-endothelial interactions in the cerebral microcirculation from the male offspring in adult life.

    Science.gov (United States)

    Misan, Vanessa; Estato, Vanessa; de Velasco, Patricia Coelho; Spreafico, Flavia Brasil; Magri, Tatiana; Dos Santos, Raísa Magno de Araújo Ramos; Fragoso, Thaiza; Souza, Amanda S; Boldarine, Valter Tadeu; Bonomo, Isabela T; Sardinha, Fátima L C; Oyama, Lila M; Tibiriçá, Eduardo; Tavares do Carmo, Maria das Graças

    2015-08-07

    We investigated whether maternal intake of normolipidic diets with distinct fatty acid (FA) compositions alters the lipidic profile and influences the inflammatory status of the adult offsprings׳ brains. C57BL/6 female mice during pregnancy and lactation received diets containing either soybean oil (CG), partially hydrogenated vegetable fat rich in trans-fatty acids (TG), palm oil (PG), or interesterified fat (IG). After weaning, male offspring from all groups received control diet. The FA profile was measured in the offspring׳s brains at post-natal days 21 and 90. Brain functional capillary density as well as leukocyte-endothelial interactions in the cerebral post-capillary venules was assessed by intravital fluorescence microscopy at post-natal day 90. Inflammation signaling was evaluated through toll-like receptor 4 (TLR4) content in brain of the adult offspring. In the 21-day old offspring, the brains of the TG showed higher levels of trans FA and reduced levels of linoleic acid (LA) and total n-6 polyunsaturated fatty acids (PUFA). At post-natal day 90, TG and IG groups showed reduced levels of eicosapentaenoic acid (EPA) and total n-3 PUFA tended to be lower compared to CG. The offspring׳s brains exhibited an altered microcirculation with increased leukocyte rolling in groups TG, PG and IG and in TG group increased leukocyte adhesion. The TLR4 content of TG, IG and PG groups only tended to increase (23%; 20% and 35%, respectively). Maternal consumption of trans FA, palm oil or interesterified fat during pregnancy and lactation can trigger the initial steps of inflammatory pathways in the brain of offspring in adulthood. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Hydrogen in metals

    CSIR Research Space (South Africa)

    Carter, TJ

    2001-04-01

    Full Text Available The effects of hydrogen on various metals and the use of metal hydrides for hydrogen storage are discussed. The mechanisms of, and differences between, hydrogen embrittlement and hydrogen attack of ferritic steels are compared, common sources...

  7. Differential effect of corn oil-based low trans structured fat on the plasma and hepatic lipid profile in an atherogenic mouse model: comparison to hydrogenated trans fat.

    Science.gov (United States)

    Cho, Yun-Young; Kwon, Eun-Young; Kim, Hye-Jin; Jeon, Seon-Min; Lee, Ki-Teak; Choi, Myung-Sook

    2011-01-20

    Trans fat are not desirable in many aspects on health maintenance. Low trans structured fats have been reported to be relatively more safe than trans fats. We examined the effects of low trans structured fat from corn oil (LC), compared with high trans fat shortening, on cholesterol and fatty acid metabolism in apo E deficient mice which is an atherogenic animal model. The animals were fed a high trans fat (10% fat: commercial shortening (CS)) or a low trans fat (LC) diet for 12 weeks. LC decreased apo B and hepatic cholesterol and triglyceride concentration compared to the CS group but significantly increased plasma total cholesterol and triglyceride concentration and fecal lipids with a simultaneous increase in HDL-cholesterol level, apo A-I, and the ratio of HDL-cholesterol to total cholesterol (HTR). Reduction of hepatic lipid levels by inclusion of LC intake was observed alongside modulation of hepatic enzyme activities related to cholesterol esterification, fatty acid metabolism and fecal lipids level compared to the CS group. The differential effects of LC intake on the plasma and hepatic lipid profile seemed to be partly due to the fatty acid composition of LC which contains higher MUFA, PUFA and SFA content as well as lower content of trans fatty acids compared to CS. We suggest that LC may exert a dual effect on plasma and hepatic lipid metabolism in an atherogenic animal model. Accordingly, LC, supplemented at 10% in diet, had an anti-atherogenic effect on these apo E-/- mice, and increased fecal lipids, decreased hepatic steatosis, but elevated plasma lipids. Further studies are needed to verify the exact mode of action regarding the complex physiological changes and alteration in lipid metabolism caused by LC.

  8. Depth profilometry via multiplexed optical high-coherence interferometry.

    Science.gov (United States)

    Kazemzadeh, Farnoud; Wong, Alexander; Behr, Bradford B; Hajian, Arsen R

    2015-01-01

    Depth Profilometry involves the measurement of the depth profile of objects, and has significant potential for various industrial applications that benefit from non-destructive sub-surface profiling such as defect detection, corrosion assessment, and dental assessment to name a few. In this study, we investigate the feasibility of depth profilometry using an Multiplexed Optical High-coherence Interferometry MOHI instrument. The MOHI instrument utilizes the spatial coherence of a laser and the interferometric properties of light to probe the reflectivity as a function of depth of a sample. The axial and lateral resolutions, as well as imaging depth, are decoupled in the MOHI instrument. The MOHI instrument is capable of multiplexing interferometric measurements into 480 one-dimensional interferograms at a location on the sample and is built with axial and lateral resolutions of 40 μm at a maximum imaging depth of 700 μm. Preliminary results, where a piece of sand-blasted aluminum, an NBK7 glass piece, and an optical phantom were successfully probed using the MOHI instrument to produce depth profiles, demonstrate the feasibility of such an instrument for performing depth profilometry.

  9. Depth profilometry via multiplexed optical high-coherence interferometry.

    Directory of Open Access Journals (Sweden)

    Farnoud Kazemzadeh

    Full Text Available Depth Profilometry involves the measurement of the depth profile of objects, and has significant potential for various industrial applications that benefit from non-destructive sub-surface profiling such as defect detection, corrosion assessment, and dental assessment to name a few. In this study, we investigate the feasibility of depth profilometry using an Multiplexed Optical High-coherence Interferometry MOHI instrument. The MOHI instrument utilizes the spatial coherence of a laser and the interferometric properties of light to probe the reflectivity as a function of depth of a sample. The axial and lateral resolutions, as well as imaging depth, are decoupled in the MOHI instrument. The MOHI instrument is capable of multiplexing interferometric measurements into 480 one-dimensional interferograms at a location on the sample and is built with axial and lateral resolutions of 40 μm at a maximum imaging depth of 700 μm. Preliminary results, where a piece of sand-blasted aluminum, an NBK7 glass piece, and an optical phantom were successfully probed using the MOHI instrument to produce depth profiles, demonstrate the feasibility of such an instrument for performing depth profilometry.

  10. Hydrogen-induced boron passivation in Cz Si

    Science.gov (United States)

    Castaldini, A.; Cavalcoli, D.; Cavallini, A.; Susi, E.

    Acceptor deactivation in the near-surface region of as-grown, boron-doped Si wafers was detected by in-depth profiles of the free-carrier density obtained by capacitance-voltage measurements. As this deactivation was only observed in wafers subjected to the standard cleaning procedures used in Si manufacturing, we ascribed it to boron passivation by an impurity introduced during the cleaning process. From the study of the free-carrier reactivation kinetics and of the diffusion behaviour of boron-impurity complexes, we have concluded that the impurity is possibly related to hydrogen introduced during the cleaning treatments. The characteristics of the deep level associated with this impurity have been analysed by deep-level transient spectroscopy.

  11. Hydrogen-induced boron passivation in Cz Si

    Energy Technology Data Exchange (ETDEWEB)

    Castaldini, A.; Cavalcoli, D.; Cavallini, A. [INFM and Physics Department, Viale Berti Pichat 6/2, 40137 Bologna (Italy); Susi, E. [CNR-LAMEL, Via Gobetti 101, 40129 Bologna (Italy)

    2002-11-01

    Acceptor deactivation in the near-surface region of as-grown, boron-doped Si wafers was detected by in-depth profiles of the free-carrier density obtained by capacitance-voltage measurements. As this deactivation was only observed in wafers subjected to the standard cleaning procedures used in Si manufacturing, we ascribed it to boron passivation by an impurity introduced during the cleaning process. From the study of the free-carrier reactivation kinetics and of the diffusion behaviour of boron-impurity complexes, we have concluded that the impurity is possibly related to hydrogen introduced during the cleaning treatments. The characteristics of the deep level associated with this impurity have been analysed by deep-level transient spectroscopy. (orig.)

  12. Surface characterization of the atmospheric contamination of hydrogenated amorphous silicon

    Energy Technology Data Exchange (ETDEWEB)

    Charenton, J.C.; Sacher, E.; McIntyre, N.S.

    1988-01-01

    Hydrogenated amorphous silicon (a-Si:H), plasma deposited under positive substrate bias, is shown to undergo atmospheric contamination after removal from the preparation chamber. The contamination rate follows complex-order kinetics and is over within 10/sup 4/ s. Auger spectroscopy depth profiles, obtained through Ar ion etching, are different than those for substrates self-biased during deposition. The same chemical structures appear to exist as are found on crystalline Si surfaces, as is evident from the fact that, when the a-Si:H surface is etched to the point where the Si:C:O ratios are the same as found on crystalline Si, the surface tensions are identical.

  13. Offshore Wind Technology Depth Zones

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Coastal bathymetric depth, measured in meters at depth values of: -30, -60, -900 Shallow Zone (0-30m): Technology has been demonstrated on a commercial scale at...

  14. Depth inpainting by tensor voting.

    Science.gov (United States)

    Kulkarni, Mandar; Rajagopalan, Ambasamudram N

    2013-06-01

    Depth maps captured by range scanning devices or by using optical cameras often suffer from missing regions due to occlusions, reflectivity, limited scanning area, sensor imperfections, etc. In this paper, we propose a fast and reliable algorithm for depth map inpainting using the tensor voting (TV) framework. For less complex missing regions, local edge and depth information is utilized for synthesizing missing values. The depth variations are modeled by local planes using 3D TV, and missing values are estimated using plane equations. For large and complex missing regions, we collect and evaluate depth estimates from self-similar (training) datasets. We align the depth maps of the training set with the target (defective) depth map and evaluate the goodness of depth estimates among candidate values using 3D TV. We demonstrate the effectiveness of the proposed approaches on real as well as synthetic data.

  15. Hydrogen isotope accumulation in the helium implantation zone in tungsten

    Science.gov (United States)

    Markelj, S.; Schwarz-Selinger, T.; Založnik, A.

    2017-06-01

    The influence of helium (He) on deuterium (D) transport and retention was studied experimentally in tungsten (W). Helium was implanted 1 µm deep into W to a maximum calculated concentration of 3.4 at.%. To minimize the influence of displacement damage created during the He implantation on D retention, so-called self-damaged W was used. W was damaged by 20 MeV W ion bombardment and defects were populated by low-temperature D plasma at room temperature before He implantation. Deuterium depth profiling was performed in situ during isochronal annealing in the temperature range from 300 K to 800 K. It is shown for the first time unambiguously that He attracts D and locally increases D trapping. Deuterium retention increased by a factor of two as compared to a non-He implanted W reference after sample annealing at 450 K. Rate equation modelling can explain the measured D depth profiles quantitatively when keeping the de-trapping parameters unchanged but only increasing the number of traps in the He zone. This bolsters the confidence in the theoretical calculations predicting that more hydrogen isotopes can be stored around a He cluster zone.

  16. Profundidade de localização do herbicida imazetapir + imazapique no solo sobre a fitotoxicidade em de plantas de arroz não resistente Depth of placement of the herbicide imazethapyr + imazapic in soil profile on non-tolerant rice injury

    Directory of Open Access Journals (Sweden)

    Angela Da Cas Bundt

    2010-09-01

    depths along the profile. This positioning can be a in-depth selectivity factor and partially explain the different results found in literature about carryover of imidazolines. To understand this effect, this study had the objective of to evaluate the effect of the positioning of the mixture of imazethapyr and imazapic (75g ai L-1 and 25g ai L-1 on the injury to non-resistant rice crop. Two experiments were carried out in soil with 15% clay and 1.2% organic matter in a greenhouse at the Universidade Federal de Pelotas, Pelotas, RS, Brazil. Experiment I consisted of a preliminary study to verify the location depth of the herbicide in the soil profile that causes injury to rice non-tolerant rice, and the herbicides has been allocated at depths of 0, 5, 10, 20, 30, 50 e 70cm. Experiment II also consisted in the allocation of herbicide at depths in the soil profile of 3, 6, 9, 12, 15 and 18cm. The variables were visual plant injury, plant shoot dry weight and plant height. The formulated mixture of imazethapyr + imazapic located near the soil surface cause injury to non resistant rice plants but when allocated at depths greater than 20cm of the soil surface does not affect the development of non-resistant rice.

  17. The use of neutron diffraction for the determination of the in-depth residual stresses profile in weld coatings; A utilizacao da difracao de neutroes na determinacao do perfil de tensoes residuais em revestimentos por soldadura

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Maria Jose; Batista, A.C.; Nobre, J.P. [Universidade de Coimbra (Portugal). Dept. de Fisica. Centro de Estudos de Materiais por Difraccao de Raios X (CEMDRX); Loureiro, Altino [Universidade de Coimbra (Portugal). Dept. de Engenharia Mecanica. Centro de Engenharia Mecanica (CEMUC); Kornmeier, Joana R., E-mail: mjvaz@fe.up.pt [Technische Universitaet Muenchen, Garching (Germany). FRM II

    2013-04-15

    The neutron diffraction is a non-destructive technique, particularly suitable for the analysis of residual stress fields in welds. The technique is used in this article to study ferritic samples, coated by submerged arc welding using stainless steel filler metals. This procedure is often used for manufacturing process equipment for chemical and nuclear industries, for ease of implementation and economic reasons. The main disadvantage of that processes is the cracking phenomenon that often occurs at the interface between the base material and coatings, which can be minimized by performing post-weld stress relief heat treatments. The samples analyzed in this study were made of carbon steel plates, coated by submerged arc welding two types of stainless steel filler metals. For the first layer was used one EN 12 072 - S 2 U 23 12 electrode, while for the second and third layers were used an EN 12 072 - 19 12 3 S L electrode. After cladding, the samples were submitted to a post-weld heat treatment for 1 hour at 620 deg C. The residual stress profiles obtained by neutron diffraction evidence the relaxation of residual stress given by the heat treatment. (author)

  18. TOPICAL REVIEW: Black silicon method X: a review on high speed and selective plasma etching of silicon with profile control: an in-depth comparison between Bosch and cryostat DRIE processes as a roadmap to next generation equipment

    Science.gov (United States)

    Jansen, H V; de Boer, M J; Unnikrishnan, S; Louwerse, M C; Elwenspoek, M C

    2009-03-01

    An intensive study has been performed to understand and tune deep reactive ion etch (DRIE) processes for optimum results with respect to the silicon etch rate, etch profile and mask etch selectivity (in order of priority) using state-of-the-art dual power source DRIE equipment. The research compares pulsed-mode DRIE processes (e.g. Bosch technique) and mixed-mode DRIE processes (e.g. cryostat technique). In both techniques, an inhibitor is added to fluorine-based plasma to achieve directional etching, which is formed out of an oxide-forming (O2) or a fluorocarbon (FC) gas (C4F8 or CHF3). The inhibitor can be introduced together with the etch gas, which is named a mixed-mode DRIE process, or the inhibitor can be added in a time-multiplexed manner, which will be termed a pulsed-mode DRIE process. Next, the most convenient mode of operation found in this study is highlighted including some remarks to ensure proper etching (i.e. step synchronization in pulsed-mode operation and heat control of the wafer). First of all, for the fabrication of directional profiles, pulsed-mode DRIE is far easier to handle, is more robust with respect to the pattern layout and has the potential of achieving much higher mask etch selectivity, whereas in a mixed-mode the etch rate is higher and sidewall scalloping is prohibited. It is found that both pulsed-mode CHF3 and C4F8 are perfectly suited to perform high speed directional etching, although they have the drawback of leaving the FC residue at the sidewalls of etched structures. They show an identical result when the flow of CHF3 is roughly 30 times the flow of C4F8, and the amount of gas needed for a comparable result decreases rapidly while lowering the temperature from room down to cryogenic (and increasing the etch rate). Moreover, lowering the temperature lowers the mask erosion rate substantially (and so the mask selectivity improves). The pulsed-mode O2 is FC-free but shows only tolerable anisotropic results at -120 °C. The

  19. The hydrogen; L'hydrogene

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    The hydrogen as an energy system represents nowadays a main challenge (in a scientific, economical and environmental point of view). The physical and chemical characteristics of hydrogen are at first given. Then, the challenges of an hydrogen economy are explained. The different possibilities of hydrogen production are described as well as the distribution systems and the different possibilities of hydrogen storage. Several fuel cells are at last presented: PEMFC, DMFC and SOFC. (O.M.)

  20. Limits on the Abundance and Burial Depth of Lunar Polar Ice

    Science.gov (United States)

    Elphic, Richard C.; Paige, David A.; Siegler, Matthew A.; Vasavada, Ashwin R.; Teodoro, Luis A.; Eke, Vincent R.

    2012-01-01

    The Diviner imaging radiometer experiment aboard the Lunar Reconnaissance Orbiter has revealed that surface temperatures in parts of the lunar polar regions are among the lowest in the solar system. Moreover, modeling of these Diviner data using realistic thermal conductivity profiles for lunar regolith and topography-based illumination has been done, with surprising results. Large expanses of circum-polar terrain appear to have near-subsurface temperatures well below 110K, despite receiving episodic low-angle solar illumination [Paige et al., 2010]. These subsurface cold traps could provide areally extensive reservoirs of volatiles. Here we examine the limits to abundance and burial depth of putative volatiles, based on the signature they would create for orbital thermal and epithermal neutrons. Epithermals alone are not sufficient to break the abundance-depth ambiguity, while thermal neutrons provide an independent constraint on the problem. The subsurface cold traps are so large that even modest abundances, well below that inferred from LCROSS observations, would produce readily detectable signatures in the Lunar Prospector neutron spectrometer data [Colaprete et al., 2010]. Specifically, we forward-model the thermal and epithermal neutron leakage flux that would be observed for various ice concentrations, given the depth at which ice stability begins. The LCROSS results point to a water-equivalent hydrogen abundance (WEH) in excess of 10 wt%, when all hydrogenous species are added together (except for H2, detected by LAMP on LRO [Gladstone et al., 2010]). When such an ice abundance is placed in a layer below the stability depth of Paige et al., the epithermal and thermal neutron leakage fluxes are vastly reduced and very much at odds with orbital observations. So clearly an environment that is conducive to cold trapping is necessary but not sufficient for the presence of volatiles such as water. We present the limits on the abundances that are indeed consistent

  1. In-depth profiling and analysis of host and viral microRNAs in Japanese flounder (Paralichthys olivaceus) infected with megalocytivirus reveal involvement of microRNAs in host-virus interaction in teleost fish.

    Science.gov (United States)

    Zhang, Bao-cun; Zhang, Jian; Sun, Li

    2014-10-08

    MicroRNAs (miRNAs) regulate gene expression by binding to mRNA transcripts in various biological processes. In mammals and birds, miRNAs are known to play vital parts in both host immune defense and viral infection. However, in lower vertebrates such as teleost, systematic investigations on host and viral miRNAs are lacking. In this study, we applied high-throughput sequencing technology to identify and analyze both host and viral miRNAs in Japanese flounder (Paralichthys olivaceus), an economically important teleost fish farmed widely in the world, infected with megalocytivirus at a timescale of 14 days divided into five different time points. The results showed that a total of 381 host miRNAs and 9 viral miRNAs were identified, the latter being all novel miRNAs that have no homologues in the currently available databases. Of the host miRNAs, 251 have been reported previously in flounder and other species, and 130 were discovered for the first time. The expression levels of 121 host miRNAs were significantly altered at 2 d to 14 d post-viral infection (pi), and these miRNAs were therefore classified as differentially expressed host miRNAs. The expression levels of all 9 viral miRNAs increased from 0 d pi to 10 d pi and then dropped from 10 d pi to 14 d pi. For the 121 differentially expressed host miRNAs and the 9 viral miRNAs, 243 and 48 putative target genes, respectively, were predicted in flounder. GO and KEGG enrichment analysis revealed that the putative target genes of both host and viral miRNAs were grouped mainly into the categories of immune response, signal transduction, and apoptotic process. The results of our study provide the first evidences that indicate existence in teleost fish (i) infection-responsive host and viral miRNAs that exhibit dynamic changes in expression profiles during the course of viral infection, and (ii) potential involvement of miRNAs in host-viral interaction.

  2. Estimating the Rut Depth by UAV Photogrammetry

    Directory of Open Access Journals (Sweden)

    Paavo Nevalainen

    2017-12-01

    Full Text Available The rut formation during forest operations is an undesirable phenomenon. A methodology is being proposed to measure the rut depth distribution of a logging site by photogrammetric point clouds produced by unmanned aerial vehicles (UAV. The methodology includes five processing steps that aim at reducing the noise from the surrounding trees and undergrowth for identifying the trails. A canopy height model is produced to focus the point cloud on the open pathway around the forest machine trail. A triangularized ground model is formed by a point cloud filtering method. The ground model is vectorized using the histogram of directed curvatures (HOC method to produce an overall ground visualization. Finally, a manual selection of the trails leads to an automated rut depth profile analysis. The bivariate correlation (Pearson’s r between rut depths measured manually and by UAV photogrammetry is r = 0.67 . The two-class accuracy a of detecting the rut depth exceeding 20 cm is a = 0.65 . There is potential for enabling automated large-scale evaluation of the forestry areas by using autonomous drones and the process described.

  3. Depth dependent modification of optical constants arising from H+ implantation in n-type 4H-SiC measured using coherent acoustic phonons

    Directory of Open Access Journals (Sweden)

    Andrey Baydin

    2016-06-01

    Full Text Available Silicon carbide (SiC is a promising material for new generation electronics including high power/high temperature devices and advanced optical applications such as room temperature spintronics and quantum computing. Both types of applications require the control of defects particularly those created by ion bombardment. In this work, modification of optical constants of 4H-SiC due to hydrogen implantation at 180 keV and at fluences ranging from 1014 to 1016 cm−2 is reported. The depth dependence of the modified optical constants was extracted from coherent acoustic phonon spectra. Implanted spectra show a strong dependence of the 4H-SiC complex refractive index depth profile on H+ fluence. These studies provide basic insight into the dependence of optical properties of 4H silicon carbide on defect densities created by ion implantation, which is of relevance to the fabrication of SiC-based photonic and optoelectronic devices.

  4. Influence of hydrogen on hydrogenated cadmium telluride optical spectra

    Energy Technology Data Exchange (ETDEWEB)

    Pociask, M.; Polit, J.; Sheregii, E.; Cebulski, J. [Institute of Physics, University of Rzeszow (Poland); Kisiel, A. [Institute of Physics, Jagiellonian University, Krakow (Poland); Mycielski, A. [Institute of Physics, PAS, Warszawa (Poland); Morgiel, J. [Polish Academy of Sciences, Institute of Metallurgy and Materials Sciences, Krakow (Poland); Piccinini, M. [INFN-Laboratori Nazionali di Frascati (Italy); Dipartimento Scienze Geologiche, Universita Roma Tre, Rome (Italy); Marcelli, A.; Robouch, B.; Guidi, M.C. [INFN-Laboratori Nazionali di Frascati (Italy); Savchyn, V. [Ivan Franko Lviv National University (Ukraine); Izhnin, I.I. [Institute for Materials SRC ' ' Carat' ' , Lviv (Ukraine); Zajdel, P. [Institute of Fizyki, University of Silesia, 4 Uniwersytecka Str., 40-007 Katowice (Poland); Nucara, A. [Universita' di Roma La Sapienza, P. le Aldo Moro 1, Rome (Italy)

    2009-09-15

    The presence of oxygen impurity in semiconducting materials affects the electrical properties of crystals and significantly limits their application. To remove oxygen impurity, ultra-pure hydrogen is used while growing Te-containing crystals such as CdTe, CdZnTe, and ZnTe. The hydrogenation of CdTe crystals is a technological process that purifies the basic material from oxygen, mainly cadmium and tellurium oxide compounds incorporated in CdTe crystalline lattice. In the present work we analyses the deformations induced by hydrogen and oxygen atoms in CdTe crystals looking at their influence on the near fundamental band (NFB), middle infrared (MIR) and far infrared (FIR) reflectivity spectra as well as on cathodoluminescence (CL) spectra. Comparison of the hydrogenated CdTe phonon structure profiles confirms the presence of hydrogen atoms bounded inside the lattice. The possible localization of hydrogen and oxygen ions within the tetrahedron coordinated lattice is discussed in the framework of a model that shows a good agreement with recent NFB, MIR and FIR experiments carried out on hydrogenated CdTe crystals. Measured reflection spectra in the wavelength range 190-1400 nm (NFB) indicate the appearance in CdTe(H{sub M}) and CdTe(H{sub L}) of additional maxima at 966 nm related to the electron transitions from level about 0.2 eV above the valence band. The CL spectra confirmed existence of this electron level. We present a possible H{sub 2} alignment similar to the single H model i.e., over the face (at about 0.38 Aa). For this model the angle from the central atom to the H atoms is equal to 64 which is also close to the bonding angle of CdH{sub 2} (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  5. Evaluation of Depth of Field for depth perception in DVR

    KAUST Repository

    Grosset, A.V.Pascal

    2013-02-01

    In this paper we present a user study on the use of Depth of Field for depth perception in Direct Volume Rendering. Direct Volume Rendering with Phong shading and perspective projection is used as the baseline. Depth of Field is then added to see its impact on the correct perception of ordinal depth. Accuracy and response time are used as the metrics to evaluate the usefulness of Depth of Field. The onsite user study has two parts: static and dynamic. Eye tracking is used to monitor the gaze of the subjects. From our results we see that though Depth of Field does not act as a proper depth cue in all conditions, it can be used to reinforce the perception of which feature is in front of the other. The best results (high accuracy & fast response time) for correct perception of ordinal depth occurs when the front feature (out of the two features users were to choose from) is in focus and perspective projection is used. © 2013 IEEE.

  6. A small and compact AMS facility for tritium depth profiling

    Indian Academy of Sciences (India)

    and HD ions are selected with an 82.5Æ deflection magnet and are accelerated using the. Tandetron at a terminal voltage of 1.5 MV. No disturbing negative 3He ions are generated inside a Cs sputtering ion source. During stripping in the nitrogen gas stripper canal most of the HD and H3 ions are split into atomic ions.

  7. Assessing the identifiability in isotope exchange depth profiling measurements

    DEFF Research Database (Denmark)

    Ciucci, Francesco; Panagakos, Grigorios; Chen, Chi

    2014-01-01

    Accurate identification of the physical parameters describing the surface exchange kinetic coefficient k and oxygen diffusion coefficient D is key in solid state ionics, because the performance of many ionic devices is connected to such quantities. In this work we extend and generalize the concept...

  8. depth profiling of aluminium metal using slow positron beam

    African Journals Online (AJOL)

    Layers, Journal of Non-Crystalline. Solids(338 340),612-616. Pujari, P. K., Sudarshan, K., Goswami, A.,. Manohar, S. B., Aswal D. K., Singh, A.,. Sen, 5., and Gupta, S. K. (2002):. Positron Annihilation Studies of MgB2. Superconductor, Physical Review B (66). 012518-1 012518 4. Suzuki, N., Nagai, Y., Itoh, Y., Goto, A, Yano,.

  9. depth profiling of aluminium metal using slow positron beam

    African Journals Online (AJOL)

    Introduction positrons are attracted by both negatively. Positron annihilation techniques are very vital Charged and neuttm defeet5= Where they ate analytical tool in condensed matter and trapped when a dlfhlsmg P051tr0h_90mes 1h materials physics In the last two and half contact_W1th an electron, they annihilate each.

  10. Sub-nanometer resolution XPS depth profiling: Sensing of atoms

    Science.gov (United States)

    Szklarczyk, Marek; Macak, Karol; Roberts, Adam J.; Takahashi, Kazuhiro; Hutton, Simon; Głaszczka, Rafał; Blomfield, Christopher

    2017-07-01

    The development of a method capable of distinguishing a single atom in a single molecule is important in many fields. The results reported herein demonstrate sub-nanometer resolution for angularly resolved X-ray photoelectron spectroscopy (ARXPS). This is made possible by the incorporation of a Maximum Entropy Method (MEM) model, which utilize density corrected electronic emission factors to the X-ray photoelectron spectroscopy (XPS) experimental results. In this paper we report on the comparison between experimental ARXPS results and reconstructed for both inorganic and organic thin film samples. Unexpected deviations between experimental data and calculated points are explained by the inaccuracy of the constants and standards used for the calculation, e.g. emission factors, scattering intensity and atomic density through the studied thickness. The positions of iron, nitrogen and fluorine atoms were determined in the molecules of the studied self-assembled monolayers. It has been shown that reconstruction of real spectroscopic data with 0.2 nm resolution is possible.

  11. A small and compact AMS facility for tritium depth profiling

    Indian Academy of Sciences (India)

    Forschungszentrum Rossendorf, Institute of Ion Beam Physics and Materials Research, P.O. Box 51 01 19, D-01314 Dresden, Germany; Forschungszentrum Karlsruhe, Tritium Laboratory, P.O. Box 35 40, D-76021 Karlsruhe, Germany; Department of Physics, University of Lund, Sölvegatan 14, SE-223 62 Lund, Sweden ...

  12. A hydrogen ice cube

    NARCIS (Netherlands)

    Peters, C.J.; Schoonman, J.; Schrauwers, A.

    2004-01-01

    Hydrogen is considered to be a highly promising energy carrier. Nonetheless, before hydrogen can become the fuel of choice for the future a number of slight problems will have to be overcome. For example, how can hydrogen be safely stored? Motor vehicles running on hydrogen may be clean in concept

  13. Improving Focal Depth Estimates: Studies of Depth Phase Detection at Regional Distances

    Science.gov (United States)

    Stroujkova, A.; Reiter, D. T.; Shumway, R. H.

    2006-12-01

    The accurate estimation of the depth of small, regionally recorded events continues to be an important and difficult explosion monitoring research problem. Depth phases (free surface reflections) are the primary tool that seismologists use to constrain the depth of a seismic event. When depth phases from an event are detected, an accurate source depth is easily found by using the delay times of the depth phases relative to the P wave and a velocity profile near the source. Cepstral techniques, including cepstral F-statistics, represent a class of methods designed for the depth-phase detection and identification; however, they offer only a moderate level of success at epicentral distances less than 15°. This is due to complexities in the Pn coda, which can lead to numerous false detections in addition to the true phase detection. Therefore, cepstral methods cannot be used independently to reliably identify depth phases. Other evidence, such as apparent velocities, amplitudes and frequency content, must be used to confirm whether the phase is truly a depth phase. In this study we used a variety of array methods to estimate apparent phase velocities and arrival azimuths, including beam-forming, semblance analysis, MUltiple SIgnal Classification (MUSIC) (e.g., Schmidt, 1979), and cross-correlation (e.g., Cansi, 1995; Tibuleac and Herrin, 1997). To facilitate the processing and comparison of results, we developed a MATLAB-based processing tool, which allows application of all of these techniques (i.e., augmented cepstral processing) in a single environment. The main objective of this research was to combine the results of three focal-depth estimation techniques and their associated standard errors into a statistically valid unified depth estimate. The three techniques include: 1. Direct focal depth estimate from the depth-phase arrival times picked via augmented cepstral processing. 2. Hypocenter location from direct and surface-reflected arrivals observed on sparse

  14. Deuterium-Hydrogen Interdiffusion in Olivine: Implications for Point Defects and Electrical Conductivity

    Science.gov (United States)

    Tyburczy, J. A.; Du Frane, W. L.

    2011-12-01

    Knowledge about hydrogen diffusivity in mantle minerals is critical for determining mantle hydrogen distribution, and additionally for understanding point defects. Chemical diffusion of hydrogen in olivine depends on self diffusion and concentration of hydrogen and other point defects, such as small polarons and metal vacancies. In this study we measured hydrogen self diffusion in olivine, and we compare these values to those previously reported for chemical 1-H redox exchange DExch. Deuterium 2-H was interdiffused into hydrogen 1-H saturated single crystals of San Carlos olivine between 750-900 °C at 2 GPa. We measured and fit the resulting 2-H and 1-H profiles to obtain the interdiffusion coefficient DH,[100] = 10^(-5.04+/-1.43)*e(-137+/-31kJ/mol)/(RT) m^2/s. This is ~1 log unit lower than DExch,[100], with similar activation energy Ea,[100]. DH is anisotropic with DH,[001] = 10^(-12.0+/-0.2) m^2/s at 900 °C and 2 GPa; only upper bound estimates for DH,[010] could be determined from our experiments. We use DH,[100] and DExch,[100] to calculate the small polaron diffusion coefficient associated with redox exchange Dh,[100] = 10^-3.90*e(-142kJ/mol)/(RT) m^2/s. Dh,[100] is combined with reported values for DExch,[010] and DExch,[010] to calculate values for DH,[010] and DH,[001] that are consistent with our upper bound estimates. These DH values, both measured and derived, are used with the Nernst-Einstein relation to calculate the electrical conductivity σ by hydrogen in olivine σH. We calculate σH = 10^1.63*e(-126kJ/mol)/(RT) S/m, which is similar in magnitude to the lower range of reported σ measurements. This similarly suggests that hydrogen alone cannot account for high σ anomalies observed at asthenospheric depths (~10^-2 to ~10^-1 S/m). The Ea for hydrogen mobility/diffusion we calculate are higher (~40% for 100 ppmw H2O) than those derived from previous σ measurements. This work supported by NSF EAR 0739050 to J. A. Tyburczy and R. Hervig. The SIMS

  15. Full depth reclamation : workshop materials.

    Science.gov (United States)

    2011-01-01

    Rehabilitating an old pavement by pulverizing and stabilizing the existing pavement is a process referred to as Full Depth Reclamation (FDR). This process shows great potential as an economical rehabilitation alternative that provides deep structural...

  16. Archetypal Depth Criticism and Melville.

    Science.gov (United States)

    Maud, Ralph

    1983-01-01

    Applies psychologist James Hillman's idea of soul-making to literary studies. Uses the works of Melville to discuss the terms (1) depth, (2) image, and (3) archetype as they relate to the concept of soul-making. (MM)

  17. ISLSCP II Ecosystem Rooting Depths

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: The goal of this study was to predict the global distribution of plant rooting depths based on data about global aboveground vegetation structure and...

  18. ISLSCP II Ecosystem Rooting Depths

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of this study was to predict the global distribution of plant rooting depths based on data about global aboveground vegetation structure and climate....

  19. Variable-Depth Liner Evaluation Using Two NASA Flow Ducts

    Science.gov (United States)

    Jones, M. G.; Nark, D. M.; Watson, W. R.; Howerton, B. M.

    2017-01-01

    Four liners are investigated experimentally via tests in the NASA Langley Grazing Flow Impedance Tube. These include an axially-segmented liner and three liners that use reordering of the chambers. Chamber reordering is shown to have a strong effect on the axial sound pressure level profiles, but a limited effect on the overall attenuation. It is also shown that bent chambers can be used to reduce the liner depth with minimal effects on the attenuation. A numerical study is also conducted to explore the effects of a planar and three higher-order mode sources based on the NASA Langley Curved Duct Test Rig geometry. A four-segment liner is designed using the NASA Langley CDL code with a Python-based optimizer. Five additional liner designs, four with rearrangements of the first liner segments and one with a redistribution of the individual chambers, are evaluated for each of the four sources. The liner configuration affects the sound pressure level profile much more than the attenuation spectra for the planar and first two higher-order mode sources, but has a much larger effect on the SPL profiles and attenuation spectra for the last higher-order mode source. Overall, axially variable-depth liners offer the potential to provide improved fan noise reduction, regardless of whether the axially variable depths are achieved via a distributed array of chambers (depths vary from chamber to chamber) or a group of zones (groups of chambers for which the depth is constant).

  20. Why hydrogen; Pourquoi l'hydrogene?

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-02-01

    The energy consumption increase and the associated environmental risks, led to develop new energy sources. The authors present the potentialities of the hydrogen in this context of energy supply safety. They detail the today market and the perspectives, the energy sources for the hydrogen production (fossils, nuclear and renewable), the hydrogen transport, storage, distribution and conversion, the application domains, the associated risks. (A.L.B.)

  1. Hydrogen nanobubble at normal hydrogen electrode

    Science.gov (United States)

    Nakabayashi, S.; Shinozaki, R.; Senda, Y.; Yoshikawa, H. Y.

    2013-05-01

    Electrochemically formed hydrogen nanobubbles at a platinum rotating disk electrode (RDE) were detected by re-oxidation charge. The dissolution time course of the hydrogen nanobubbles was measured by AFM tapping topography under open-circuit conditions at stationary platinum and gold single-crystal electrodes. The bubble dissolution at platinum was much faster than that at gold because two types of diffusion, bulk and surface diffusion, proceeded at the platinum surface, whereas surface diffusion was prohibited at the gold electrode. These findings indicated that the electrochemical reaction of normal hydrogen electrode partly proceeded heterogeneously on the three-phase boundary around the hydrogen nanobubble.

  2. Global Estimates of PBL Depth from Space-Borne LIDAR

    Science.gov (United States)

    McGrath-Spangler, Erica lynn; Denning, S.; Molod, A.; Ott, L.

    2012-01-01

    The planetary boundary layer (PBL) is responsible for communicating the exchange of energy, moisture, momentum, pollutants, and aerosols between the surface and the free atmosphere and is therefore crucial to many studies of the atmosphere. Unfortunately, there have historically been few observations of this important layer due to the complexity involved in its measurement. However, with the advent of more advanced satellites, global measurements of the PBL are now becoming possible. The PBL is often characterized by a high concentration of aerosols within the layer and low level clouds capping it and these are observable from space. The Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite was launched in 2006 with the intention of observing aerosols and clouds and was the first space-based LIDAR optimized for this purpose. CALIPSO observations are therefore well suited to observing the depth of the PBL. Since it was launched, CALIPSO has been making nearly continuous measurements enabling a global picture of PBL depth. We plan to present a global PBL depth product and how it evolves throughout the year. The product is able to identify deeper PBL depths in the summer hemisphere over land and deeper depths along the northern hemisphere oceanic storm tracks in winter associated with cold air traveling over warm water. Large seasonal cycles are also evident in the subtropical desert locations among other features. In addition, comparisons will be made between several estimates of PBL depth based on turbulent intensity, meteorology profiles, and aerosol profiles from the GEOS5 model.

  3. Impact of maximum borehole depths on ground warming patterns: A spatial analysis over the Northern Hemisphere

    Science.gov (United States)

    Beltrami, Hugo; Matharoo, Gurpreet S.; Smerdon, Jason E.

    2013-04-01

    Past variations in the Earth's surface energy balance are preserved in the terrestrial subsurface and can be inferred from borehole temperature-depth profiles. These profiles are used to reconstruct past ground surface temperature (GST) histories. Recent work by Beltrami et al. (2011) has shown that estimated GST histories can be significantly impacted by the maximum depth of the borehole temperature measurement. In the present study, we use temperature-depth profiles measured at 558 sites distributed between 30o N and 60o N in the Northern Hemisphere. For each site, the background steady-state temperature profile is estimated using progressively deeper maximum depths of truncation. Additionally, GST histories are reconstructed using multiple maximum depth truncations. In order to control on the influence of the geographical sampling, shallow boreholes are dropped from the analysis once their depth is surpassed. The estimated temperature changes over 50-yr intervals are evaluated in these reconstructions as a function of the maximum truncation depth in the database. Similarly, the total terrestrial heat gain is also estimated using progressive depths of truncations. All calculations show a significant dependence on the maximum depths of the borehole profiles and further indicate the importance of this factor in estimates of past temperature and heat content histories derived from geothermal data. Further, calculations also show that the ground has warmed by 0.5o over last 100 years consistent with the earlier studies by Beltrami and Bourlon (2004).

  4. Influence of helium on hydrogen isotope exchange in tungsten at sequential exposures to deuterium and helium–protium plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Bobyr, N.P., E-mail: NPBobyr@gmail.com [NRC “Kurcharov Institute”, Ac. Kurcharov sq., 1/1, Moscow 123182 (Russian Federation); Alimov, V.Kh. [Max-Planck-Institut für Plasmaphysik, D-85748 Garching (Germany); Hydrogen Isotope Research Center, University of Toyama, Toyama 930-8555 (Japan); Khripunov, B.I.; Spitsyn, A.V. [NRC “Kurcharov Institute”, Ac. Kurcharov sq., 1/1, Moscow 123182 (Russian Federation); Mayer, M. [Max-Planck-Institut für Plasmaphysik, D-85748 Garching (Germany); Hatano, Y. [Hydrogen Isotope Research Center, University of Toyama, Toyama 930-8555 (Japan); Golubeva, A.V.; Petrov, V.B. [NRC “Kurcharov Institute”, Ac. Kurcharov sq., 1/1, Moscow 123182 (Russian Federation)

    2015-08-15

    Hydrogen isotopes exchange in tungsten was investigated after sequential exposures to low energy deuterium (D) and helium–seeded protium (He–seeded H) plasmas at sample temperatures of 403 and 533 K. Deuterium depth profiles were measured by the D({sup 3}He, p){sup 4}He nuclear reaction with {sup 3}He{sup +} energies between 0.69 and 4.5 MeV allowing determination of the D concentration up to a depth of 8 μm. It was found that a significant part of the deuterium initially retained in tungsten after D plasma exposure was released during sequential exposure to a protium plasma. However, exposure of the D-plasma-exposed W samples to the He–seeded H plasma reduces the amount of released deuterium as compared to pure H plasma exposure.

  5. Hydrogen energy systems studies

    Energy Technology Data Exchange (ETDEWEB)

    Ogden, J.M.; Kreutz, T.G.; Steinbugler, M. [Princeton Univ., NJ (United States)] [and others

    1996-10-01

    In this report the authors describe results from technical and economic assessments carried out during the past year with support from the USDOE Hydrogen R&D Program. (1) Assessment of technologies for small scale production of hydrogen from natural gas. Because of the cost and logistics of transporting and storing hydrogen, it may be preferable to produce hydrogen at the point of use from more readily available energy carriers such as natural gas or electricity. In this task the authors assess near term technologies for producing hydrogen from natural gas at small scale including steam reforming, partial oxidation and autothermal reforming. (2) Case study of developing a hydrogen vehicle refueling infrastructure in Southern California. Many analysts suggest that the first widespread use of hydrogen energy is likely to be in zero emission vehicles in Southern California. Several hundred thousand zero emission automobiles are projected for the Los Angeles Basin alone by 2010, if mandated levels are implemented. Assuming that hydrogen vehicles capture a significant fraction of this market, a large demand for hydrogen fuel could evolve over the next few decades. Refueling a large number of hydrogen vehicles poses significant challenges. In this task the authors assess near term options for producing and delivering gaseous hydrogen transportation fuel to users in Southern California including: (1) hydrogen produced from natural gas in a large, centralized steam reforming plant, and delivered to refueling stations via liquid hydrogen truck or small scale hydrogen gas pipeline, (2) hydrogen produced at the refueling station via small scale steam reforming of natural gas, (3) hydrogen produced via small scale electrolysis at the refueling station, and (4) hydrogen from low cost chemical industry sources (e.g. excess capacity in refineries which have recently upgraded their hydrogen production capacity, etc.).

  6. Anterior chamber depth during hemodialysis

    Directory of Open Access Journals (Sweden)

    Gracitelli CPB

    2013-08-01

    Full Text Available Carolina Pelegrini Barbosa Gracitelli,1 Francisco Rosa Stefanini,1 Fernando Penha,1 Miguel Ângelo Góes,2 Sérgio Antonio Draibe,2 Maria Eugênia Canziani,2 Augusto Paranhos Junior1 1Ophthalmology Department, 2Division of Nephrology, Federal University of São Paulo – UNIFESP, São Paulo, Brazil Background: Exacerbation of chronic glaucoma or acute glaucoma is occasionally observed in patients undergoing hemodialysis (HD because of anterior chamber depth changes during this therapy. Purpose: To evaluate anterior chamber depth and axial length in patients during HD sessions. Methods: A total of 67 eyes of 35 patients were prospectively enrolled. Axial length and anterior chamber depth were measured using ultrasonic biometry, and these measures were evaluated at three different times during HD sessions. Body weight and blood pressure pre- and post-HD were also measured. Results: There was no difference in the axial length between the three measurements (P = 0.241. We observed a significantly decreased anterior chamber depth (P = 0.002 during HD sessions. Conclusion: Our results support the idea that there is a change in anterior chamber depth in HD sessions. Keywords: anterior chamber, hemodialysis, axial length, acute angle-closure glaucoma

  7. Hydrogen in semiconductors

    CERN Document Server

    Pankove, Jacques I

    1991-01-01

    Hydrogen plays an important role in silicon technology, having a profound effect on a wide range of properties. Thus, the study of hydrogen in semiconductors has received much attention from an interdisciplinary assortment of researchers. This sixteen-chapter volume provides a comprehensive review of the field, including a discussion of hydrogenation methods, the use of hydrogen to passivate defects, the use of hydrogen to neutralize deep levels, shallow acceptors and shallow donors in silicon, vibrational spectroscopy, and hydrogen-induced defects in silicon. In addition to this detailed cove

  8. Single and double acceptor-levels of a carbon-hydrogen defect in n-type silicon

    Energy Technology Data Exchange (ETDEWEB)

    Stübner, R.; Scheffler, L.; Kolkovsky, Vl., E-mail: kolkov@ifpan.edu.pl; Weber, J. [Technische Universität Dresden, 01062 Dresden (Germany)

    2016-05-28

    In the present study, we discuss the origin of two dominant deep levels (E42 and E262) observed in n-type Si, which is subjected to hydrogenation by wet chemical etching or a dc H-plasma treatment. Their activation enthalpies determined from Laplace deep level transient spectroscopy measurements are E{sub C}-0.06 eV (E42) and E{sub C}-0.51 eV (E262). The similar annealing behavior and identical depth profiles of E42 and E262 correlate them with two different charge states of the same defect. E262 is attributed to a single acceptor state due to the absence of the Poole-Frenkel effect and the lack of a capture barrier for electrons. The emission rate of E42 shows a characteristic enhancement with the electric field, which is consistent with the assignment to a double acceptor state. In samples with different carbon and hydrogen content, the depth profiles of E262 can be explained by a defect with one H-atom and one C-atom. From a comparison with earlier calculations [Andersen et al., Phys. Rev. B 66, 235205 (2002)], we attribute E42 to the double acceptor and E262 to the single acceptor state of the CH{sub 1AB} configuration, where one H atom is directly bound to carbon in the anti-bonding position.

  9. Single and double acceptor-levels of a carbon-hydrogen defect in n-type silicon

    Science.gov (United States)

    Stübner, R.; Scheffler, L.; Kolkovsky, Vl.; Weber, J.

    2016-05-01

    In the present study, we discuss the origin of two dominant deep levels (E42 and E262) observed in n-type Si, which is subjected to hydrogenation by wet chemical etching or a dc H-plasma treatment. Their activation enthalpies determined from Laplace deep level transient spectroscopy measurements are EC-0.06 eV (E42) and EC-0.51 eV (E262). The similar annealing behavior and identical depth profiles of E42 and E262 correlate them with two different charge states of the same defect. E262 is attributed to a single acceptor state due to the absence of the Poole-Frenkel effect and the lack of a capture barrier for electrons. The emission rate of E42 shows a characteristic enhancement with the electric field, which is consistent with the assignment to a double acceptor state. In samples with different carbon and hydrogen content, the depth profiles of E262 can be explained by a defect with one H-atom and one C-atom. From a comparison with earlier calculations [Andersen et al., Phys. Rev. B 66, 235205 (2002)], we attribute E42 to the double acceptor and E262 to the single acceptor state of the CH1AB configuration, where one H atom is directly bound to carbon in the anti-bonding position.

  10. A comparison of mixing depths observed over horizontally inhomogeneous terrain

    Energy Technology Data Exchange (ETDEWEB)

    White, A.B. [Univ. of Colorado/NOAA Environmental Technology Lab., Cooperative Inst. for Research in Environmental Sciences, Boulder, CO (United States); King, C.W. [NOAA Environmental Technology Lab., Boulder, CO (United States)

    1997-10-01

    In this paper we used wind profiler observations to estimate the mixing depth on either side of the Continental Divide on days when a PTBC (plain-to-basin-circulation) occurred along the Front Range of Colorado during the summer of 1995. The mixing depths on the basin side were significantly deeper than the mountain barrier for all of the PTBC events we analyzed. On the plains side, the mixed layers often extended to or above the level of the mountain barrier. On certain days up-slope flow existed above the mixed layer. We depicted the vertical structure of the flow and features in the humidity profile on one of these days using measurements from a wind profiler. The results were consistent with the conceptual model presented by Wolyn and McKee (1994). (au)

  11. Catalytic hydrogenation of carbon monoxide

    Energy Technology Data Exchange (ETDEWEB)

    Wayland, B.B.

    1992-12-01

    This project is focused on developing strategies to accomplish the reduction and hydrogenation of carbon monoxide to produce organic oxygenates at mild conditions. Our approaches to this issue are based on the recognition that rhodium macrocycles have unusually favorable thermodynamic values for producing a series of intermediate implicated in the catalytic hydrogenation of CO. Observations of metalloformyl complexes produced by reactions of H{sub 2} and CO, and reductive coupling of CO to form metallo {alpha}-diketone species have suggested a multiplicity of routes to organic oxygenates that utilize these species as intermediates. Thermodynamic and kinetic-mechanistic studies are used in constructing energy profiles for a variety of potential pathways, and these schemes are used in guiding the design of new metallospecies to improve the thermodynamic and kinetic factors for individual steps in the overall process. Variation of the electronic and steric effects associated with the ligand arrays along with the influences of the reaction medium provide the chemical tools for tuning these factors. Emerging knowledge of the factors that contribute to M-H, M-C and M-O bond enthalpies is directing the search for ligand arrays that will expand the range of metal species that have favorable thermodynamic parameters to produce the primary intermediates for CO hydrogenation. Studies of rhodium complexes are being extended to non-macrocyclic ligand complexes that emulate the favorable thermodynamic features associated with rhodium macrocycles, but that also manifest improved reaction kinetics. Multifunctional catalyst systems designed to couple the ability of rhodium complexes to produce formyl and diketone intermediates with a second catalyst that hydrogenates these imtermediates are promising approaches to accomplish CO hydrogenation at mild conditions.

  12. Handbook of hydrogen energy

    CERN Document Server

    Sherif, SA; Stefanakos, EK; Steinfeld, Aldo

    2014-01-01

    ""This book provides an excellent overview of the hydrogen economy and a thorough and comprehensive presentation of hydrogen production and storage methods.""-Scott E. Grasman, Rochester Institute of Technology, New York, USA

  13. Center for Hydrogen Storage.

    Science.gov (United States)

    2013-06-01

    The main goals of this project were to (1) Establish a Center for Hydrogen Storage Research at Delaware State University for the preparation and characterization of selected complex metal hydrides and the determination their suitability for hydrogen ...

  14. Hydrogen production by Cyanobacteria

    Directory of Open Access Journals (Sweden)

    Chaudhuri Surabhi

    2005-12-01

    Full Text Available Abstract The limited fossil fuel prompts the prospecting of various unconventional energy sources to take over the traditional fossil fuel energy source. In this respect the use of hydrogen gas is an attractive alternate source. Attributed by its numerous advantages including those of environmentally clean, efficiency and renew ability, hydrogen gas is considered to be one of the most desired alternate. Cyanobacteria are highly promising microorganism for hydrogen production. In comparison to the traditional ways of hydrogen production (chemical, photoelectrical, Cyanobacterial hydrogen production is commercially viable. This review highlights the basic biology of cynobacterial hydrogen production, strains involved, large-scale hydrogen production and its future prospects. While integrating the existing knowledge and technology, much future improvement and progress is to be done before hydrogen is accepted as a commercial primary energy source.

  15. Hydrogen transport membranes

    Science.gov (United States)

    Mundschau, Michael V.

    2005-05-31

    Composite hydrogen transport membranes, which are used for extraction of hydrogen from gas mixtures are provided. Methods are described for supporting metals and metal alloys which have high hydrogen permeability, but which are either too thin to be self supporting, too weak to resist differential pressures across the membrane, or which become embrittled by hydrogen. Support materials are chosen to be lattice matched to the metals and metal alloys. Preferred metals with high permeability for hydrogen include vanadium, niobium, tantalum, zirconium, palladium, and alloys thereof. Hydrogen-permeable membranes include those in which the pores of a porous support matrix are blocked by hydrogen-permeable metals and metal alloys, those in which the pores of a porous metal matrix are blocked with materials which make the membrane impervious to gases other than hydrogen, and cermets fabricated by sintering powders of metals with powders of lattice-matched ceramic.

  16. Solar hydrogen generator

    Science.gov (United States)

    Sebacher, D. I.; Sabol, A. P. (Inventor)

    1977-01-01

    An apparatus, using solar energy to manufacture hydrogen by dissociating water molecules into hydrogen and oxygen molecules is described. Solar energy is concentrated on a globe containing water thereby heating the water to its dissociation temperature. The globe is pervious to hydrogen molecules permitting them to pass through the globe while being essentially impervious to oxygen molecules. The hydrogen molecules are collected after passing through the globe and the oxygen molecules are removed from the globe.

  17. Hydrogen Technologies Safety Guide

    Energy Technology Data Exchange (ETDEWEB)

    Rivkin, C. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Burgess, R. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Buttner, W. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-01-01

    The purpose of this guide is to provide basic background information on hydrogen technologies. It is intended to provide project developers, code officials, and other interested parties the background information to be able to put hydrogen safety in context. For example, code officials reviewing permit applications for hydrogen projects will get an understanding of the industrial history of hydrogen, basic safety concerns, and safety requirements.

  18. Depth estimation via stage classification

    NARCIS (Netherlands)

    Nedović, V.; Smeulders, A.W.M.; Redert, A.; Geusebroek, J.M.

    2008-01-01

    We identify scene categorization as the first step towards efficient and robust depth estimation from single images. Categorizing the scene into one of the geometric classes greatly reduces the possibilities in subsequent phases. To that end, we introduce 15 typical 3D scene geometries, called

  19. Factors that affect keratotomy depth.

    Science.gov (United States)

    Merlin, U; Bordin, P; Rimondi, A P; Sichirollo, R

    1991-01-01

    The authors investigated nine factors which can affect the depth of incisions performed during refractive keratotomy: (1) vertical vs oblique-cutting edge of the knife blade, (2) direction of cutting, (3) cutting velocity, (4) American vs Russian technique, (5) intraocular pressure (IOP), (6) initial vs final incisions, (7) sharpness of knife blade, (8) single vs double footplate, and (9) square vs double-edged blade. These variables were examined independently, performing at least 40 incisions for each experimental parameter studied. The depth of the resulting incisions was measured histologically using the micrometer eyepiece. The average and the standard deviation were calculated. The paired Student's t-test was used to establish significant differences between the two conditions investigated for each parameter. Factors that were demonstrated to increase significantly the depth of the incisions included: the vertical-cutting edge, the triple-edged diamond knife, the sharpness of the knife, and the single foot knife. High velocity in performing the incisions and, to a lesser extent, low IOP were the main factors that induced irregularity in depth.

  20. Magnesium for Hydrogen Storage

    DEFF Research Database (Denmark)

    Vigeholm, B.; Kjøller, John; Larsen, Bent

    1980-01-01

    The reaction of hydrogen with commercially pure magnesium powder (above 99.7%) was investigated in the temperature range 250–400 °C. Hydrogen is readily sorbed above the dissociation pressure. During the initial exposure the magnesium powder sorbs hydrogen slowly below 400 °C but during the second...

  1. Biological hydrogen photoproduction

    Energy Technology Data Exchange (ETDEWEB)

    Nemoto, Y. [Univ. of Miami, FL (United States)

    1995-09-01

    Following are the major accomplishments of the 6th year`s study of biological hydrogen photoproduction which were supported by DOE/NREL. (1) We have been characterizing a biological hydrogen production system using synchronously growing aerobically nitrogen-fixing unicellular cyanobacterium, Synechococcus sp. Miami BG 043511. So far it was necessary to irradiate the cells to produce hydrogen. Under darkness they did not produce hydrogen. However, we found that, if the cells are incubated with oxygen, they produce hydrogen under the dark. Under 80% argon + 20% oxygen condition, the hydrogen production activity under the dark was about one third of that under the light + argon condition. (2) Also it was necessary so far to incubate the cells under argon atmosphere to produce hydrogen in this system. Argon treatment is very expensive and should be avoided in an actual hydrogen production system. We found that, if the cells are incubated at a high cell density and in a container with minimum headspace, it is not necessary to use argon for the hydrogen production. (3) Calcium ion was found to play an important role in the mechanisms of protection of nitrogenase from external oxygen. This will be a clue to understand the reason why the hydrogen production is so resistant to oxygen in this strain. (4) In this strain, sulfide can be used as electron donor for the hydrogen production. This result shows that waste water can be used for the hydrogen production system using this strain.

  2. Hydrogen Production for Refuelling Applications

    Energy Technology Data Exchange (ETDEWEB)

    Hulteberg, Christian; Aagesen, Diane (Intelligent Energy, Long Beach, CA (United States))

    2009-08-15

    The aim of this work is to support the development of a high-profile demonstration of hydrogen generation technologies in a Swedish context. The overall objective of the demonstration is to deploy a reforming based hydrogen refilling station along the Swedish west coast; intermediate to the Malmoe refuelling station and planned stations in Goeteborg. In this way, the Norwegian hydrogen highway will be extended through the south of Sweden and down into Denmark. The aim of the project's first phase, where this constitutes the final report, was to demonstrate the ability to operate the IE reforming system on the E.On/SGC site-specific fuel. During the project, a preliminary system design has been developed, based on IE's proprietary reformer. The system has been operated at pressure, to ensure a stable operation of the downstream PSA; which has been operated without problems and with the expected hydrogen purity and recovery. The safe operation of the proposed and tested system was first evaluated in a preliminary risk assessment, as well as a full HazOp analysis. A thorough economic modelling has been performed on the viability of owning and operating this kind of hydrogen generation equipment. The evaluation has been performed from an on-site operation of such a unit in a refuelling context. The general conclusion from this modelling is that there are several parameters that influence the potential of an investment in a Hestia hydrogen generator. The sales price of the hydrogen is one of the major drivers of profitability. Another important factor is the throughput of the unit, more important than efficiency and utilization. Varying all of the parameters simultaneously introduce larger variations in the NPV, but 60% of the simulations are in the USD 90 000 to USD 180 000 interval. The chosen intervals for the parameters were: Hydrogen Sales Price (USD 5 - USD 7 per kg); Investment Cost (USD 70 000 - USD 130 000 per unit); Throughput (20 - 30 kg

  3. Spectrum analysis of hydrogen plasma in spherically convergent beam fusion

    Energy Technology Data Exchange (ETDEWEB)

    Ogasawara, Kazuki; Yamauchi, Kunihito; Watanabe, Masato; Sunaga, Yoshitaka; Hotta, Eiki [Tokyo Institute of Technology, Dept. of Energy Sciences, Yokohama, Kanagawa (Japan); Okino, Akitoshi [Tokyo Institute of Technology, Dept. of Electrical and Electronic Engineering, Tokyo (Japan)

    2001-09-01

    Spectroscopic analysis of spherical glow discharge fusion device was carried out using hydrogen gas. Effects of the discharge current and cathode voltage on spectrum profiles of hydrogen Balmar lines were measured. The profiles of all hydrogen lines were broadened with the cathode voltage. From the relationship between the maximum broadening width and the cathode voltage, it was indicated that the broadening was caused by the Doppler effect. From the spatial distribution of emission intensity, it was found that plasma core size became larger with discharge current and smaller with cathode voltage. (author)

  4. Hydrogen separation process

    Science.gov (United States)

    Mundschau, Michael [Longmont, CO; Xie, Xiaobing [Foster City, CA; Evenson, IV, Carl; Grimmer, Paul [Longmont, CO; Wright, Harold [Longmont, CO

    2011-05-24

    A method for separating a hydrogen-rich product stream from a feed stream comprising hydrogen and at least one carbon-containing gas, comprising feeding the feed stream, at an inlet pressure greater than atmospheric pressure and a temperature greater than 200.degree. C., to a hydrogen separation membrane system comprising a membrane that is selectively permeable to hydrogen, and producing a hydrogen-rich permeate product stream on the permeate side of the membrane and a carbon dioxide-rich product raffinate stream on the raffinate side of the membrane. A method for separating a hydrogen-rich product stream from a feed stream comprising hydrogen and at least one carbon-containing gas, comprising feeding the feed stream, at an inlet pressure greater than atmospheric pressure and a temperature greater than 200.degree. C., to an integrated water gas shift/hydrogen separation membrane system wherein the hydrogen separation membrane system comprises a membrane that is selectively permeable to hydrogen, and producing a hydrogen-rich permeate product stream on the permeate side of the membrane and a carbon dioxide-rich product raffinate stream on the raffinate side of the membrane. A method for pretreating a membrane, comprising: heating the membrane to a desired operating temperature and desired feed pressure in a flow of inert gas for a sufficient time to cause the membrane to mechanically deform; decreasing the feed pressure to approximately ambient pressure; and optionally, flowing an oxidizing agent across the membrane before, during, or after deformation of the membrane. A method of supporting a hydrogen separation membrane system comprising selecting a hydrogen separation membrane system comprising one or more catalyst outer layers deposited on a hydrogen transport membrane layer and sealing the hydrogen separation membrane system to a porous support.

  5. Safe venting of hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, W.F.; Dewart, J.M.; Edeskuty, F.J.

    1990-01-01

    The disposal of hydrogen is often required in the operation of an experimental facility that contains hydrogen. Whether the vented hydrogen can be discharged to the atmosphere safely depends upon a number of factors such as the flow rate and atmospheric conditions. Calculations have been made that predict the distance a combustible mixture can extend from the point of release under some specified atmospheric conditions. Also the quantity of hydrogen in the combustible cloud is estimated. These results can be helpful in deciding of the hydrogen can be released directly to the atmosphere, or if it must be intentionally ignited. 15 refs., 5 figs., 2 tabs.

  6. Identification of surface hydrogen enhancements within the Moon’s Shackleton crater

    Science.gov (United States)

    Miller, Richard S.; Lawrence, David J.; Hurley, Dana M.

    2014-05-01

    Bulk surface hydrogen enhancements have been identified within the Moon’s Shackleton crater. Using an analysis of fast and epithermal neutron data from the Lunar Prospector mission, the permanently shadowed region (PSR) within this crater has a surface concentration of 0.72 ± 0.13 wt.% water equivalent hydrogen (WEH). In contrast, hydrogen enhancements within other polar PSRs such as Cabeus are likely buried under more than 10 cm of hydrogen-poor regolith. Subsurface hydrogen absent a surficial counterpart implies an episodic delivery mechanism. The burial depth suggests the epoch of hydrogen deposition was at least 100 myr ago if impact gardening is the dominant mechanism for volatile transport to depth. Shackleton crater’s surface enhancement may be related to its thermal environment, ∼30 K warmer than other south pole PSRs, in which thermal processes control the vertical migration of hydrogen within Shackleton but inhibit migration in colder regions.

  7. Hydrogen energy for beginners

    CERN Document Server

    2013-01-01

    This book highlights the outstanding role of hydrogen in energy processes, where it is the most functional element due to its unique peculiarities that are highlighted and emphasized in the book. The first half of the book covers the great natural hydrogen processes in biology, chemistry, and physics, showing that hydrogen is a trend that can unite all natural sciences. The second half of the book is devoted to the technological hydrogen processes that are under research and development with the aim to create the infrastructure for hydrogen energetics. The book describes the main features of hydrogen that make it inalienable player in processes such as fusion, photosynthesis, and metabolism. It also covers the methods of hydrogen production and storage, highlighting at the same time the exclusive importance of nanotechnologies in those processes.

  8. Cyclooctanaminium hydrogen succinate monohydrate

    Directory of Open Access Journals (Sweden)

    Sanaz Khorasani

    2012-04-01

    Full Text Available In the title hydrated salt, C8H18N+·C4H5O4−·H2O, the cyclooctyl ring of the cation is disordered over two positions in a 0.833 (3:0.167 (3 ratio. The structure contains various O—H.·O and N—H...O interactions, forming a hydrogen-bonded layer of molecules perpendicular to the c axis. In each layer, the ammonium cation hydrogen bonds to two hydrogen succinate anions and one water molecule. Each hydrogen succinate anion hydrogen bonds to neighbouring anions, forming a chain of molecules along the b axis. In addition, each hydrogen succinate anion hydrogen bonds to two water molecules and the ammonium cation.

  9. Direct depth distribution measurement of deuterium in bulk tungsten exposed to high-flux plasma

    Directory of Open Access Journals (Sweden)

    C. N. Taylor

    2017-05-01

    Full Text Available Understanding tritium retention and permeation in plasma-facing components is critical for fusion safety and fuel cycle control. Glow discharge optical emission spectroscopy (GD-OES is shown to be an effective tool to reveal the depth profile of deuterium in tungsten. Results confirm the detection of deuterium. A ∼46 μm depth profile revealed that the deuterium content decreased precipitously in the first 7 μm, and detectable amounts were observed to depths in excess of 20 μm. The large probing depth of GD-OES (up to 100s of μm enables studies not previously accessible to the more conventional techniques for investigating deuterium retention. Of particular applicability is the use of GD-OES to measure the depth profile for experiments where high deuterium concentration in the bulk material is expected: deuterium retention in neutron irradiated materials, and ultra-high deuterium fluences in burning plasma environment.

  10. Limit of crustal drilling depth

    Directory of Open Access Journals (Sweden)

    Y.S. Zhao

    2017-10-01

    Full Text Available Deep drilling is becoming the direct and the most efficient means in exploiting deep mineral resources, facilitating to understanding the earthquake mechanism and performing other scientific researches on the Earth's crust. In order to understand the limit of drilling depth in the Earth's crust, we first conducted tests on granite samples with respect to the borehole deformation and stability under high temperature and high pressure using the triaxial servo-controlled rock testing system. Then the critical temperature-pressure coupling conditions that result in borehole instability are derived. Finally, based on the testing results obtained and the requirements for the threshold values of borehole deformations during deep drilling, the limit of drilling depth in the Earth's crust is formulated with ground temperature.

  11. Depth measurement in integral images.

    OpenAIRE

    Wu, ChunHong

    2003-01-01

    The development of a satisfactory the three-dimensional image system is a constant pursuit of the scientific community and entertainment industry. Among the many different methods of producing three-dimensional images, integral imaging is a technique that is capable of creating and encoding a true volume spatial optical model of the object scene in the form of a planar intensity distribution by using unique optical components. The generation of depth maps from three-dimensional integral image...

  12. Depth dependent charge state distributions of heavy MeV ions in RBS and ERD experiments

    Science.gov (United States)

    Jamecsny, S.; Carstanjen, H. D.

    1997-04-01

    At the Max-Planck-Institut für Metallforschung in Stuttgart, Germany, a 6 MV Pelletron accelerator is being used for surface analysis by means of high resolution RBS and ERD using an electrostatic spectrometer. For the ERD analysis of ions heavier than hydrogen the recording of a second parameter is necessary to identify the particle species and its charge state. For this purpose a set-up was installed that combines the high energy resolution of the spectrometer with a measurement of the time of flight of the ions through the spectrometer using a chopped ion beam. The technique also allows to measure charge state dependent depth profiles. Energy spectra of all observable charge states were recorded for backscattered Ne and Ar ions from Au and of recoil O ions from Ta 2O 5 and Al 2O 3. The comparison of a computer simulation of the charge exchange processes with the measurements of Ar scattering on Au yields mean free path lengths for electron capture and loss.

  13. Hydrogen storage methods

    Science.gov (United States)

    Züttel, Andreas

    Hydrogen exhibits the highest heating value per mass of all chemical fuels. Furthermore, hydrogen is regenerative and environmentally friendly. There are two reasons why hydrogen is not the major fuel of today's energy consumption. First of all, hydrogen is just an energy carrier. And, although it is the most abundant element in the universe, it has to be produced, since on earth it only occurs in the form of water and hydrocarbons. This implies that we have to pay for the energy, which results in a difficult economic dilemma because ever since the industrial revolution we have become used to consuming energy for free. The second difficulty with hydrogen as an energy carrier is its low critical temperature of 33 K (i.e. hydrogen is a gas at ambient temperature). For mobile and in many cases also for stationary applications the volumetric and gravimetric density of hydrogen in a storage material is crucial. Hydrogen can be stored using six different methods and phenomena: (1) high-pressure gas cylinders (up to 800 bar), (2) liquid hydrogen in cryogenic tanks (at 21 K), (3) adsorbed hydrogen on materials with a large specific surface area (at Tchemically bonded in covalent and ionic compounds (at ambient pressure), or (6) through oxidation of reactive metals, e.g. Li, Na, Mg, Al, Zn with water. The most common storage systems are high-pressure gas cylinders with a maximum pressure of 20 MPa (200 bar). New lightweight composite cylinders have been developed which are able to withstand pressures up to 80 MPa (800 bar) and therefore the hydrogen gas can reach a volumetric density of 36 kg.m-3, approximately half as much as in its liquid state. Liquid hydrogen is stored in cryogenic tanks at 21.2 K and ambient pressure. Due to the low critical temperature of hydrogen (33 K), liquid hydrogen can only be stored in open systems. The volumetric density of liquid hydrogen is 70.8 kg.m-3, and large volumes, where the thermal losses are small, can cause hydrogen to reach a

  14. Dynamics of hydrogen in hydrogenated amorphous silicon

    Indian Academy of Sciences (India)

    bonding configuration due to hydrogen migration have been proposed as a mechanism of defect generation in a-Si:H [6,7]. Thus hydrogen plays a dual role in a-Si:H: (1) acting as a .... the sphere of radius R0 and allows to express. ∆F as a function of localization radius R0. Using eqs (10) and (11), the volume integration.

  15. Hydrogen diffusivity in oxide layers formed in Zr alloy in air or steam

    Science.gov (United States)

    Kato, Taro; Takagi, Ikuji; Sakamoto, Kan; Aomi, Masaki

    2017-10-01

    The effect of the oxidation conditions on hydrogen diffusion in oxide layers in Zr alloy was experimentally studied. Samples of GNF-Ziron (high-iron Zircaloy-2-type alloy) sheets were oxidized in air or steam and then exposed to deuterium plasma to charge them with deuterium. Deuterium depth profiles in each sample were observed by nuclear reaction analysis during plasma exposure, and the deuterium diffusion coefficient D was estimated. The results showed that the D values of the steam-oxidized samples were high, whereas that of a steam-oxidized sample that was subsequently heated in vacuum was as low as those of air-oxidized samples. The difference in D was not attributed to the structure but is probably due to the presence of OH groups absorbed during steam oxidation.

  16. Application of ERDA method to study hydrogen and helium in Ti,Zr and Nb membranes

    Energy Technology Data Exchange (ETDEWEB)

    Nagata, S.; Takahiro, K.; Yamaguchi, S. [Tohoku Univ., Sendai (Japan). Inst. for Materials Research; Yamamoto, S.; Tsuchiya, B.; Naramoto, H. [Department of Materials Development, JAERI, Takasaki, Gunma 370-12 (Japan)

    1998-03-01

    Hydrogen and helium behavior in Ti, Zr and Nb membranes of several {mu}m thickness was investigated by elastic recoil detection analysis (ERDA) using 6 MeV O and 12 MeV C beams in the transmission geometry. The concentration depth profiles of H and He during the {sup 4}He implantation were simultaneously measured in the membranes containing uniformly distributed H of about 0.1 at.%. During the {sup 4}He implantation into Ti, Zr and Nb membranes, an enrichment of the H concentration was observed at the depth corresponding to the range of the implanted {sup 4}He ions. In the Nb membrane, a reversible change of the H profile was observed on heating and cooling runs. The trapping energy of H in defects created by 10 keV {sup 4}He implantation in the Nb membrane was estimated to be 0.14{+-}0.03 eV from the change in H concentration on cooling after the {sup 4}He implantation at 500 K. (orig.) 12 refs.

  17. Hydrogen Filling Station

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, Robert F; Sabacky, Bruce; Anderson II, Everett B; Haberman, David; Al-Hassin, Mowafak; He, Xiaoming; Morriseau, Brian

    2010-02-24

    Hydrogen is an environmentally attractive transportation fuel that has the potential to displace fossil fuels. The Freedom CAR and Freedom FUEL initiatives emphasize the importance of hydrogen as a future transportation fuel. Presently, Las Vegas has one hydrogen fueling station powered by natural gas. However, the use of traditional sources of energy to produce hydrogen does not maximize the benefit. The hydrogen fueling station developed under this grant used electrolysis units and solar energy to produce hydrogen fuel. Water and electricity are furnished to the unit and the output is hydrogen and oxygen. Three vehicles were converted to utilize the hydrogen produced at the station. The vehicles were all equipped with different types of technologies. The vehicles were used in the day-to-day operation of the Las Vegas Valley Water District and monitoring was performed on efficiency, reliability and maintenance requirements. The research and demonstration utilized for the reconfiguration of these vehicles could lead to new technologies in vehicle development that could make hydrogen-fueled vehicles more cost effective, economical, efficient and more widely used. In order to advance the development of a hydrogen future in Southern Nevada, project partners recognized a need to bring various entities involved in hydrogen development and deployment together as a means of sharing knowledge and eliminating duplication of efforts. A road-mapping session was held in Las Vegas in June 2006. The Nevada State Energy Office, representatives from DOE, DOE contractors and LANL, NETL, NREL were present. Leadership from the National hydrogen Association Board of Directors also attended. As a result of this session, a roadmap for hydrogen development was created. This roadmap has the ability to become a tool for use by other road-mapping efforts in the hydrogen community. It could also become a standard template for other states or even countries to approach planning for a hydrogen

  18. Hydrogen Bond Basicity Prediction for Medicinal Chemistry Design.

    Science.gov (United States)

    Kenny, Peter W; Montanari, Carlos A; Prokopczyk, Igor M; Ribeiro, Jean F R; Sartori, Geraldo Rodrigues

    2016-05-12

    Hydrogen bonding is discussed in the context of medicinal chemistry design. Minimized molecular electrostatic potential (Vmin) is shown to be an effective predictor of hydrogen bond basicity (pKBHX), and predictive models are presented for a number of hydrogen bond acceptor types relevant to medicinal chemistry. The problems posed by the presence of nonequivalent hydrogen bond acceptor sites in molecular structures are addressed by using nonlinear regression to fit measured pKBHX to calculated Vmin. Predictions are made for hydrogen bond basicity of fluorine in situations where relevant experimental measurements are not available. It is shown how predicted pKBHX can be used to provide insight into the nature of bioisosterism and to profile heterocycles. Examples of pKBHX prediction for molecular structures with multiple, nonequivalent hydrogen bond acceptors are presented.

  19. Influence of screening effect on hydrogen passivation of hole silicon

    CERN Document Server

    Aleksandrov, O V

    2002-01-01

    The simulation of hole silicon passivation during hydrogen diffusion with account of hydrogen-acceptor pairs formation, internal electrical field and screening effect has been carried out. Screening by free carriers of hydrogen and acceptor ions results in shortening their interaction radii and slacking the concentration dependence of hydrogen diffusivity at high level of silicon doping. The consistency of simulated and experimental profiles of holes and hydrogen-acceptor pairs is reached in a broad band of doping levels from 4 x 10 sup 1 sup 4 to 1.2 x 10 sup 2 sup 0 cm sup - sup 3 at the pair binding energy of 0.70-0.79 eV while the radius of the Coulomb interaction of hydrogen and boron ions is equal to 35 A under low doping and decrease with increasing doping level

  20. Hydrogen energy systems studies

    Energy Technology Data Exchange (ETDEWEB)

    Ogden, J.M.; Steinbugler, M.; Kreutz, T. [Princeton Univ., NJ (United States). Center for Energy and Environmental Studies

    1998-08-01

    In this progress report (covering the period May 1997--May 1998), the authors summarize results from ongoing technical and economic assessments of hydrogen energy systems. Generally, the goal of their research is to illuminate possible pathways leading from present hydrogen markets and technologies toward wide scale use of hydrogen as an energy carrier, highlighting important technologies for RD and D. Over the past year they worked on three projects. From May 1997--November 1997, the authors completed an assessment of hydrogen as a fuel for fuel cell vehicles, as compared to methanol and gasoline. Two other studies were begun in November 1997 and are scheduled for completion in September 1998. The authors are carrying out an assessment of potential supplies and demands for hydrogen energy in the New York City/New Jersey area. The goal of this study is to provide useful data and suggest possible implementation strategies for the New York City/ New Jersey area, as the Hydrogen Program plans demonstrations of hydrogen vehicles and refueling infrastructure. The authors are assessing the implications of CO{sub 2} sequestration for hydrogen energy systems. The goals of this work are (a) to understand the implications of CO{sub 2} sequestration for hydrogen energy system design; (b) to understand the conditions under which CO{sub 2} sequestration might become economically viable; and (c) to understand design issues for future low-CO{sub 2} emitting hydrogen energy systems based on fossil fuels.

  1. Estimating plant water uptake source depths with optimized stable water isotope labeling

    Science.gov (United States)

    Seeger, Stefan; Weiler, Markus

    2016-04-01

    Depth profiles of pore water stable isotopes in soils in conjunction with measurements of stable water isotopes (SWI) in plant transpiration allow the estimation of the contributions of different soil depths to plant water uptake (PWU).
 However, SWI depth profiles that result from the variations of SWI in natural precipitation may lead to highly ambiguous results, i.e. the same SWI signature in transpiration could result from different PWU patterns or SWI depth profiles. The aim of this study was to find an optimal stable water isotope depth profile to estimate plant water uptake patterns and to compare different PWU source depth estimation methods. We used a new soil water transport model including fractionation effects of SWI and exchange between the vapor and liquid phase to simulate different irrigation scenarios. Different amounts of water with differing SWI signatures (glacier melt water, summer precipitation water, deuterated water) were applied in order to obtain a wide variety of SWI depth profiles. Based on these simulated SWI depth profiles and a set of hypothetical PWU patterns, the theoretical SWI signatures of the respective plant transpiration were computed. In the next step, two methods - Bayesian isotope mixing models (BIMs) and optimization of a parametric distribution function (beta function) - were used to estimate the PWU patterns from the different SWI depth profiles and their respective SWI signatures in the resulting transpiration. Eventually, the estimated and computed profiles were compared to find the best SWI depth profile and the best method. The results showed, that compared to naturally occurring SWI depth profiles, the application of multiple, in terms of SWI, distinct labeling pulses greatly improves the possible spatial resolution and at the same time reduces the uncertainty of PWU estimates.
 For the PWU patterns which were assumed for this study, PWU pattern estimates based on an optimized parametric distribution function

  2. Subdivision depth for triangular surfaces

    Directory of Open Access Journals (Sweden)

    G. Mustafa

    2016-06-01

    Full Text Available The aim of this attempt was to present an efficient algorithm for the evaluation of error bound of triangular subdivision surfaces. The error estimation technique is based on first order difference and this process is independent of parametrization. This technique can be easily generalized to higher arity triangular surfaces. The estimated error bound is expressed in-terms of initial control point sequence and constants. Here, we efficiently estimate error bound between triangular surface and its control polygon after k-fold subdivision and further extended to evaluate subdivision depth of the scheme.

  3. Structural modeling from depth images.

    Science.gov (United States)

    Nguyen, Thanh; Reitmayr, Gerhard; Schmalstieg, Dieter

    2015-11-01

    In this work, we present a new automatic system for scene reconstruction of high-level structural models. We start with identifying planar regions in depth images obtained with a SLAM system. Our main contribution is an approach which identifies constraints such as incidence and orthogonality of planar surfaces and uses them in an incremental optimization framework to extract high-level structural models. The result is a manifold mesh with a low number of polygons, immediately useful in many Augmented Reality applications such as inspection, interior design or spatial interaction.

  4. Static stereo vision depth distortions in teleoperation

    Science.gov (United States)

    Diner, D. B.; Von Sydow, M.

    1988-01-01

    A major problem in high-precision teleoperation is the high-resolution presentation of depth information. Stereo television has so far proved to be only a partial solution, due to an inherent trade-off among depth resolution, depth distortion and the alignment of the stereo image pair. Converged cameras can guarantee image alignment but suffer significant depth distortion when configured for high depth resolution. Moving the stereo camera rig to scan the work space further distorts depth. The 'dynamic' (camera-motion induced) depth distortion problem was solved by Diner and Von Sydow (1987), who have quantified the 'static' (camera-configuration induced) depth distortion. In this paper, a stereo image presentation technique which yields aligned images, high depth resolution and low depth distortion is demonstrated, thus solving the trade-off problem.

  5. Allylammonium hydrogen oxalate hemihydrate

    Directory of Open Access Journals (Sweden)

    Błażej Dziuk

    2014-08-01

    Full Text Available In the title hydrated molecular salt, C3H8N+·C2HO4−·0.5H2O, the water O atom lies on a crystallographic twofold axis. The C=C—C—N torsion angle in the cation is 2.8 (3° and the dihedral angle between the CO2 and CO2H planes in the anion is 1.0 (4°. In the crystal, the hydrogen oxalate ions are linked by O—H...O hydrogen bonds, generating [010] chains. The allylammonium cations bond to the chains through N—H...O and N—H...(O,O hydrogen bonds. The water molecule accepts two N—H...O hydrogen bonds and makes two O—H...O hydrogen bonds. Together, the hydrogen bonds generate (100 sheets.

  6. Hydrogen Fuelling Stations

    DEFF Research Database (Denmark)

    Rothuizen, Erasmus Damgaard

    This thesis concerns hydrogen fuelling stations from an overall system perspective. The study investigates thermodynamics and energy consumption of hydrogen fuelling stations for fuelling vehicles for personal transportation. For the study a library concerning the components in a hydrogen fuelling...... station has been developed in Dymola. The models include the fuelling protocol (J2601) for hydrogen vehicles made by Society of Automotive Engineers (SAE) and the thermodynamic property library CoolProp is used for retrieving state point. The components in the hydrogen fuelling library are building up....... A system consisting of one high pressure storage tank is used to investigate the thermodynamics of fuelling a hydrogen vehicle. The results show that the decisive parameter for how the fuelling proceeds is the pressure loss in the vehicle. The single tank fuelling system is compared to a cascade fuelling...

  7. Hydrogen energy systems studies

    Energy Technology Data Exchange (ETDEWEB)

    Ogden, J.M.; Steinbugler, M.; Dennis, E. [Princeton Univ., NJ (United States)] [and others

    1995-09-01

    For several years, researchers at Princeton University`s Center for Energy and Environmental Studies have carried out technical and economic assessments of hydrogen energy systems. Initially, we focussed on the long term potential of renewable hydrogen. More recently we have explored how a transition to renewable hydrogen might begin. The goal of our current work is to identify promising strategies leading from near term hydrogen markets and technologies toward eventual large scale use of renewable hydrogen as an energy carrier. Our approach has been to assess the entire hydrogen energy system from production through end-use considering technical performance, economics, infrastructure and environmental issues. This work is part of the systems analysis activity of the DOE Hydrogen Program. In this paper we first summarize the results of three tasks which were completed during the past year under NREL Contract No. XR-11265-2: in Task 1, we carried out assessments of near term options for supplying hydrogen transportation fuel from natural gas; in Task 2, we assessed the feasibility of using the existing natural gas system with hydrogen and hydrogen blends; and in Task 3, we carried out a study of PEM fuel cells for residential cogeneration applications, a market which might have less stringent cost requirements than transportation. We then give preliminary results for two other tasks which are ongoing under DOE Contract No. DE-FG04-94AL85803: In Task 1 we are assessing the technical options for low cost small scale production of hydrogen from natural gas, considering (a) steam reforming, (b) partial oxidation and (c) autothermal reforming, and in Task 2 we are assessing potential markets for hydrogen in Southern California.

  8. Pathways to Metallic Hydrogen

    OpenAIRE

    Silvera, Isaac F.; Deemyad, Shanti

    2008-01-01

    The traditional pathway that researchers have used in the goal of producing atomic metallic hydrogen is to compress samples with megabar pressures at low temperature. A number of phases have been observed in solid hydrogen and its isotopes, but all are in the insulating phase. The results of experiment and theory for this pathway are reviewed. In recent years a new pathway has become the focus of this challenge of producing metallic hydrogen, namely a path along the melting line. It has bee...

  9. Hydrogen rich gas generator

    Science.gov (United States)

    Houseman, J. (Inventor)

    1976-01-01

    A process and apparatus is described for producing a hydrogen rich gas by introducing a liquid hydrocarbon fuel in the form of a spray into a partial oxidation region and mixing with a mixture of steam and air that is preheated by indirect heat exchange with the formed hydrogen rich gas, igniting the hydrocarbon fuel spray mixed with the preheated mixture of steam and air within the partial oxidation region to form a hydrogen rich gas.

  10. Hydrogen Fuel Cell Vehicles

    OpenAIRE

    Delucchi, Mark

    1992-01-01

    Hydrogen is an especially attractive transportation fuel. It is the least polluting fuel available, and can be produced anywhere there is water and a clean source of electricity. A fuel cycle in which hydrogen is produced by solar-electrolysis of water, or by gasification of renewably grown biomass, and then used in a fuel-cell powered electric-motor vehicle (FCEV), would produce little or no local, regional, or global pollution. Hydrogen FCEVs would combine the best features of bat...

  11. Investigation of nickel hydrogen battery technology for the RADARSAT spacecraft

    Science.gov (United States)

    Mccoy, D. A.; Lackner, J. L.

    1986-01-01

    The low Earth orbit (LEO) operations of the RADARSAT spacecraft require high performance batteries to provide energy to the payload and platform during eclipse period. Nickel Hydrogen cells are currently competing with the more traditional Nickel Cadmium cells for high performance spacecraft applications at geostationary Earth orbit (GEO) and Leo. Nickel Hydrogen cells appear better suited for high power applications where high currents and high Depths of Discharge are required. Although a number of GEO missions have flown with Nickel Hydrogen batteries, it is not readily apparent that the LEO version of the Nickel Hydrogen cell is able to withstand the extended cycle lifetime (5 years) of the RADARSAT mission. The problems associated with Nickel Hydrogen cells are discussed in the contex of RADARSAT mission and a test program designed to characterize cell performance is presented.

  12. Liquid hydrogen in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Yasumi, S. [Iwatani Corp., Osaka (Japan). Dept. of Overseas Business Development

    2009-07-01

    Japan's Iwatani Corporation has focused its attention on hydrogen as the ultimate energy source in future. Unlike the United States, hydrogen use and delivery in liquid form is extremely limited in the European Union and in Japan. Iwatani Corporation broke through industry stereotypes by creating and building Hydro Edge Co. Ltd., Japan's largest liquid hydrogen plant. It was established in 2006 as a joint venture between Iwatani and Kansai Electric Power Group in Osaka. Hydro Edge is Japan's first combined liquid hydrogen and ASU plant, and is fully operational. Liquid oxygen, liquid nitrogen and liquid argon are separated from air using the cryogenic energy of liquefied natural gas fuel that is used for power generation. Liquid hydrogen is produced efficiently and simultaneously using liquid nitrogen. Approximately 12 times as much hydrogen in liquid form can be transported and supplied as pressurized hydrogen gas. This technology is a significant step forward in the dissemination and expansion of hydrogen in a hydrogen-based economy.

  13. In Situ Measurement of Local Hydrogen Production Rate by Bubble-Evolved Recording

    Directory of Open Access Journals (Sweden)

    Xiaowei Hu

    2013-01-01

    Full Text Available Hydrogen visibly bubbles during photocatalytic water splitting under illumination with above-bandgap radiation, which provides a direct measurement of local gas-evolving reaction rate. In this paper, optical microscopy of superfield depth was used for recording the hydrogen bubble growth on Cd0.5Zn0.5S photocatalyst in reaction liquid and illuminated with purple light. By analyzing change of hydrogen bubble size as a function of time, we understood that hydrogen bubble growth experienced two periods, which were inertia effect dominated period and diffusion effect dominated period, respectively. The tendency of hydrogen bubble growth was similar to that of the gas bubble in boiling, while the difference in bubble diameter and growth time magnitude was great. Meanwhile, we obtained the local hydrogen production rate on photocatalyst active site by measuring hydrogen bubble growth variation characteristics. This method makes it possible to confirm local actual hydrogen evolution rate quantitatively during photocatalytic water splitting.

  14. Enhancing hydrogen spillover and storage

    Science.gov (United States)

    Yang, Ralph T [Ann Arbor, MI; Li, Yingwel [Ann Arbor, MI; Lachawiec, Jr., Anthony J.

    2011-05-31

    Methods for enhancing hydrogen spillover and storage are disclosed. One embodiment of the method includes doping a hydrogen receptor with metal particles, and exposing the hydrogen receptor to ultrasonification as doping occurs. Another embodiment of the method includes doping a hydrogen receptor with metal particles, and exposing the doped hydrogen receptor to a plasma treatment.

  15. Enhancing hydrogen spillover and storage

    Science.gov (United States)

    Yang, Ralph T; Li, Yingwei; Lachawiec, Jr., Anthony J

    2013-02-12

    Methods for enhancing hydrogen spillover and storage are disclosed. One embodiment of the method includes doping a hydrogen receptor with metal particles, and exposing the hydrogen receptor to ultrasonication as doping occurs. Another embodiment of the method includes doping a hydrogen receptor with metal particles, and exposing the doped hydrogen receptor to a plasma treatment.

  16. Evolution of the nitrogen depth distribution in an implanted titanium alloy with a surface carbon nanolayer

    Science.gov (United States)

    Vlcak, Petr; Horazdovsky, Tomas; Valenta, Richard; Kovac, Janez

    2017-07-01

    The impact of the thickness of the carbon nanolayer on the depth distribution of the implanted nitrogen was examined. Ti6Al4V samples with a carbon nanolayer (20 and 40 nm) were implanted with nitrogen with fluence of 1.2 · 1017 cm-2 and an accelerating voltage of 90 kV. GD-OES measurements showed an almost Gaussian-like nitrogen depth profile. The nitrogen peak moves deeper into the sample with increasing thickness of the nanolayer. The experimental depth profiles are in good agreement with the calculated results from the analytical model and from the SRIM2013 code.

  17. Simplicial band depth for multivariate functional data

    KAUST Repository

    López-Pintado, Sara

    2014-03-05

    We propose notions of simplicial band depth for multivariate functional data that extend the univariate functional band depth. The proposed simplicial band depths provide simple and natural criteria to measure the centrality of a trajectory within a sample of curves. Based on these depths, a sample of multivariate curves can be ordered from the center outward and order statistics can be defined. Properties of the proposed depths, such as invariance and consistency, can be established. A simulation study shows the robustness of this new definition of depth and the advantages of using a multivariate depth versus the marginal depths for detecting outliers. Real data examples from growth curves and signature data are used to illustrate the performance and usefulness of the proposed depths. © 2014 Springer-Verlag Berlin Heidelberg.

  18. TES/Aura L2 Summary Profiles V004

    Data.gov (United States)

    National Aeronautics and Space Administration — Atmospheric vertical profile estimates, along with retrieved surface temperature, cloud effective optical depth, column estimates, quality flags, and a priori...

  19. TES/Aura L2 Summary Profiles V007

    Data.gov (United States)

    National Aeronautics and Space Administration — Atmospheric vertical profile estimates, along with retrieved surface temperature, cloud effective optical depth, column estimates, quality flags, and a priori...

  20. TES/Aura L2 Summary Profiles V003

    Data.gov (United States)

    National Aeronautics and Space Administration — Atmospheric vertical profile estimates, along with retrieved surface temperature, cloud effective optical depth, column estimates, quality flags, and a priori...

  1. TES/Aura L2 Summary Profiles V005

    Data.gov (United States)

    National Aeronautics and Space Administration — Atmospheric vertical profile estimates, along with retrieved surface temperature, cloud effective optical depth, column estimates, quality flags, and a priori...

  2. TES/Aura L2 Summary Profiles V006

    Data.gov (United States)

    National Aeronautics and Space Administration — Atmospheric vertical profile estimates, along with retrieved surface temperature, cloud effective optical depth, column estimates, quality flags, and a priori...

  3. Chronic consumption of fresh but not heated yogurt improves breath-hydrogen status and short-chain fatty acid profiles: a controlled study in healthy men with or without lactose maldigestion.

    Science.gov (United States)

    Rizkalla, S W; Luo, J; Kabir, M; Chevalier, A; Pacher, N; Slama, G

    2000-12-01

    Ingestion of fermented dairy products induces changes in the equilibrium and metabolism of the intestinal microflora and may thus have beneficial effects on the host. We compared the effects of chronic consumption of yogurt with (fresh) or without (heated) live bacterial cultures (Lactobacillus bulgaricus and Streptococcus thermophilus) on plasma glucose, insulin, triacylglycerols, cholesterol, fatty acids, and short-chain fatty acids. Two groups of 12 healthy men with or without lactose malabsorption were selected with use of a breath-hydrogen test after a 30-g lactose load. Subjects were randomly assigned in a crossover design to 500 g/d of either fresh or heated yogurt for 2 periods of 15 d each, separated by a 15-d washout interval. Chronic consumption of fresh or heated yogurt had no detrimental effects on plasma glucose, insulin, or fatty acid areas under the curve in response to acute ingestion of 500 g yogurt in healthy men with or without lactose malabsorption. There were also no detectable changes in fasting plasma glucose, insulin, fatty acid, triacylglycerol, or cholesterol concentrations. In contrast, plasma butyrate was higher (P: yogurt consumption than after heated yogurt consumption. There were no significant changes in plasma acetate. In subjects with lactose malabsorption, 15 d of fresh yogurt consumption also increased propionate production compared with values at baseline (P: yogurt consumption than after heated yogurt consumption (P: yogurt containing live bacterial cultures ameliorated the malabsorption, as evidenced by lower breath-hydrogen excretion, but increased propionate concentrations. In subjects without lactose malabsorption, such yogurt tended to increase propionate and increased butyrate.

  4. Hydrogen Storage Tank

    CERN Multimedia

    1983-01-01

    This huge stainless steel reservoir,placed near an end of the East Hall, was part of the safety equipment connected to the 2 Metre liquid hydrogen Bubble Chamber. It could store all the hydrogen in case of an emergency. The picture shows the start of its demolition.

  5. Metastable ultracondensed hydrogenous materials

    Science.gov (United States)

    Nellis, W. J.

    2017-12-01

    The primary purpose of this paper is to stimulate theoretical predictions of how to retain metastably hydrogenous materials made at high pressure P on release to ambient. Ultracondensed metallic hydrogen has been made at high pressures in the fluid and reported made probably in the solid. Because the long quest for metallic hydrogen is likely to be concluded in the relatively near future, a logical question is whether another research direction, comparable in scale to the quest for metallic H, will arise in high pressure research. One possibility is retention of metastable solid metallic hydrogen and other hydrogenous materials on release of dynamic and static high pressures P to ambient. If hydrogenous materials could be retained metastably on release, those materials would be a new class of materials for scientific investigations and technological applications. This paper is a review of the current situation with the synthesis of metallic hydrogen, potential technological applications of metastable metallic H and other hydrogenous materials at ambient, and general background of published experimental and theoretical work on what has been accomplished with metastable phases in the past and thus what might be accomplished in the future.

  6. Hydrogen evolution reaction catalyst

    Science.gov (United States)

    Subbaraman, Ram; Stamenkovic, Vojislav; Markovic, Nenad; Tripkovic, Dusan

    2016-02-09

    Systems and methods for a hydrogen evolution reaction catalyst are provided. Electrode material includes a plurality of clusters. The electrode exhibits bifunctionality with respect to the hydrogen evolution reaction. The electrode with clusters exhibits improved performance with respect to the intrinsic material of the electrode absent the clusters.

  7. Dark hydrogen fermentations

    NARCIS (Netherlands)

    Vrije, de G.J.; Claassen, P.A.M.

    2003-01-01

    The production of hydrogen is a ubiquitous, natural phenomenon under anoxic or anaerobic conditions. A wide variety of bacteria, in swamps, sewage, hot springs, the rumen of cattle etc. is able to convert organic matter to hydrogen, CO2 and metabolites like acetic acid, lactate, ethanol and alanine.

  8. Hyperspectral aerosol optical depths from TCAP flights

    Energy Technology Data Exchange (ETDEWEB)

    Shinozuka, Yohei [NASA Ames Research Center (ARC), Moffett Field, Mountain View, CA (United States); Bay Area Environmental REsearch Institute; Johnson, Roy R [NASA Ames Research Center (ARC), Moffett Field, Mountain View, CA (United States); Flynn, Connor J [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Russell, Philip B [NASA Ames Research Center (ARC), Moffett Field, Mountain View, CA (United States); Schmid, Beat [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-06-01

    4STAR (Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research), a hyperspectral airborne sunphotometer, acquired aerosol optical depths (AOD) at 1 Hz during all July 2012 flights of the Two Column Aerosol Project (TCAP). Root-mean-square differences from AERONET ground-based observations were 0.01 at wavelengths between 500-1020 nm, 0.02 at 380 and 1640 nm and 0.03 at 440 nm in four clear-sky fly-over events, and similar in ground side-by-side comparisons. Changes in the above-aircraft AOD across 3- km-deep spirals were typically consistent with integrals of coincident in situ (on DOE Gulfstream 1 with 4STAR) and lidar (on NASA B200) extinction measurements within 0.01, 0.03, 0.01, 0.02, 0.02, 0.02 at 355, 450, 532, 550, 700, 1064 nm, respectively, despite atmospheric variations and combined measurement uncertainties. Finer vertical differentials of the 4STAR measurements matched the in situ ambient extinction profile within 14% for one homogeneous column. For the AOD observed between 350-1660 nm, excluding strong

  9. Depth perception: the need to report ocean biogeochemical rates as functions of temperature, not depth

    Science.gov (United States)

    Brewer, Peter G.; Peltzer, Edward T.

    2017-08-01

    For over 50 years, ocean scientists have oddly represented ocean oxygen consumption rates as a function of depth but not temperature in most biogeochemical models. This unique tradition or tactic inhibits useful discussion of climate change impacts, where specific and fundamental temperature-dependent terms are required. Tracer-based determinations of oxygen consumption rates in the deep sea are nearly universally reported as a function of depth in spite of their well-known microbial basis. In recent work, we have shown that a carefully determined profile of oxygen consumption rates in the Sargasso Sea can be well represented by a classical Arrhenius function with an activation energy of 86.5 kJ mol-1, leading to a Q10 of 3.63. This indicates that for 2°C warming, we will have a 29% increase in ocean oxygen consumption rates, and for 3°C warming, a 47% increase, potentially leading to large-scale ocean hypoxia should a sufficient amount of organic matter be available to microbes. Here, we show that the same principles apply to a worldwide collation of tracer-based oxygen consumption rate data and that some 95% of ocean oxygen consumption is driven by temperature, not depth, and thus will have a strong climate dependence. The Arrhenius/Eyring equations are no simple panacea and they require a non-equilibrium steady state to exist. Where transient events are in progress, this stricture is not obeyed and we show one such possible example. This article is part of the themed issue 'Ocean ventilation and deoxygenation in a warming world'.

  10. Depth perception: the need to report ocean biogeochemical rates as functions of temperature, not depth.

    Science.gov (United States)

    Brewer, Peter G; Peltzer, Edward T

    2017-09-13

    For over 50 years, ocean scientists have oddly represented ocean oxygen consumption rates as a function of depth but not temperature in most biogeochemical models. This unique tradition or tactic inhibits useful discussion of climate change impacts, where specific and fundamental temperature-dependent terms are required. Tracer-based determinations of oxygen consumption rates in the deep sea are nearly universally reported as a function of depth in spite of their well-known microbial basis. In recent work, we have shown that a carefully determined profile of oxygen consumption rates in the Sargasso Sea can be well represented by a classical Arrhenius function with an activation energy of 86.5 kJ mol -1 , leading to a Q 10 of 3.63. This indicates that for 2°C warming, we will have a 29% increase in ocean oxygen consumption rates, and for 3°C warming, a 47% increase, potentially leading to large-scale ocean hypoxia should a sufficient amount of organic matter be available to microbes. Here, we show that the same principles apply to a worldwide collation of tracer-based oxygen consumption rate data and that some 95% of ocean oxygen consumption is driven by temperature, not depth, and thus will have a strong climate dependence. The Arrhenius/Eyring equations are no simple panacea and they require a non-equilibrium steady state to exist. Where transient events are in progress, this stricture is not obeyed and we show one such possible example.This article is part of the themed issue 'Ocean ventilation and deoxygenation in a warming world'. © 2017 The Author(s).

  11. Electrochemical Hydrogen Compressor

    Energy Technology Data Exchange (ETDEWEB)

    Lipp, Ludwig [FuelCell Energy, Inc., Torrington, CT (United States)

    2016-01-21

    Conventional compressors have not been able to meet DOE targets for hydrogen refueling stations. They suffer from high capital cost, poor reliability and pose a risk of fuel contamination from lubricant oils. This project has significantly advanced the development of solid state hydrogen compressor technology for multiple applications. The project has achieved all of its major objectives. It has demonstrated capability of Electrochemical Hydrogen Compression (EHC) technology to potentially meet the DOE targets for small compressors for refueling sites. It has quantified EHC cell performance and durability, including single stage hydrogen compression from near-atmospheric pressure to 12,800 psi and operation of EHC for more than 22,000 hours. Capital cost of EHC was reduced by 60%, enabling a path to meeting the DOE cost targets for hydrogen compression, storage and delivery ($2.00-2.15/gge by 2020).

  12. Evaluation of Unknown Tube Well Depth Using Electrical Resistivity Method

    Directory of Open Access Journals (Sweden)

    Zainal Abidin Mohd Hazreek

    2017-01-01

    Full Text Available Electrical resistivity method has increasingly adopted in engineering, environmental, mining and archaeological studies. Systematic and proper studies of unknown civil engineering structure evaluation particularly on tube well depth was rarely being established. Conventionally, camera test or string with weight approach has been used to evaluate unknown tube well depth thus exposed to several restriction due to its expensive and time consuming. Hence, this study focused on evaluation of unknown tube well depth using indirect test with particular reference to electrical resistivity method (ERM.A single spread line of electrical resistivity survey was performed using ABEM SAS 4000 equipment set based on Wenner and Pole-dipole array in line with the tube well position. Electrical resistivity raw data was processed using RES2DINV software producing electrical resistivity tomography (ERT of the subsurface profile studied. Then, electrical resistivity value (ERV obtained from RES2DINV analyses (ERT was extracted and analysed using plotted graph (depth versus ERV specifically at tube well position based on electrical resistivity spread line performed. It was found that both array have shown some good similarity results in term of tube well depth (20 m thus able to verify the result interpreted. Both array have shown some good similarity of ERV representing groundwater (ERV = 10 – 100 Ωm and soil with water (ERV > 100 Ωm at depth of 0 – 20 m and >20 m respectively. All those interpretation have shown good agreement based on verification thru established ERV of earth materials references, geological map and nearest available boreholes data. Hence, this study has shown that the application of ERM was applicable in evaluation of unknown tube well depth which efficient in term of cost, time and environmental sustainable.

  13. Chlorific efficiency of coal hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Schappert, H.

    1942-10-20

    In studies on the calorific efficiency of coal hydrogenation, the efficiency for H/sub 2/ production was calculated to be 26%, the efficiency for hydrogenation was calculated to be 49%, and the efficiency of hydrogenation including H/sub 2/ production was 27.2%. The efficiency of hydrogenation plus hydrogen production was almost equal to the efficiency of hydrogen production alone, even though this was not expected because of the total energy calculated in the efficiency of hydrogenation proper. It was entirely possible, but did not affect computations, that the efficiency of one or the other components of hydrogenation process differed somewhat from 49%. The average efficiency for all cases was 49%. However, when hydrogen was not bought, but was produced--(efficiency of hydrogen production was 26%, not 100%-- then the total energy changed and the efficiency of hydrogen production and combination was not 26%, but 13%. This lower value explained the drop of hydrogenation efficiency to 27.2%.

  14. Determination of diffusion coefficients of hydrogen and deuterium in Zr–2.5%Nb pressure tube material using hot vacuum extraction-quadrupole mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Shrivastava, Komal Chandra, E-mail: komal@barc.gov.in [Radioanalytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Kulkarni, A.S.; Ramanjaneyulu, P.S. [Radioanalytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Sunil, Saurav [Mechanical Metallurgy Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Saxena, M.K. [Radioanalytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Singh, R.N. [Mechanical Metallurgy Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Tomar, B.S.; Ramakumar, K.L. [Radioanalytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

    2015-06-15

    The diffusion coefficients of hydrogen and deuterium in Zr–2.5%Nb alloy were measured in the temperature range 523 to 673 K, employing hot vacuum extraction-quadrupole mass spectrometry (HVE-QMS). One end of the Zr–2.5%Nb alloy specimens was charged electrolytically with the desired hydrogen isotope. After annealing at different temperatures for a predetermined time, the specimens were cut into thin slices, which were analyzed for their H{sub 2}/D{sub 2} content using the HVE-QMS technique. The depth profile data were fitted into the equation representing the solution of Fick’s second law of diffusion. The activation energy of hydrogen/deuterium diffusion was obtained from the Arrhenius relation between the diffusion coefficient and temperature. The temperature dependent diffusion coefficient can be represented as D{sub H} = 1.41 × 10{sup −7} exp(−36,000/RT) and D{sub D} = 6.16 × 10{sup −8} exp(−35,262/RT) for hydrogen and deuterium, respectively.

  15. Composite material systems for hydrogen management

    Science.gov (United States)

    Pangborn, R. N.; Queeney, R. A.

    1991-01-01

    The task of managing hydrogen entry into elevated temperature structural materials employed in turbomachinery is a critical engineering area for propulsion systems employing hydrogen or decomposable hydrocarbons as fuel. Extant structural materials, such as the Inconel series, are embrittled by the ingress of hydrogen in service, leading to a loss of endurance and general deterioration of load-bearing dependability. Although the development of hydrogen-insensitive material systems is an obvious engineering option, to date insensitive systems cannot meet the time-temperature-loading service extremes encountered. A short-term approach that is both feasible and technologically sound is the development and employment of hydrogen barrier coatings. The present project is concerned with developing, analyzing, and physically testing laminate composite hydrogen barrier systems, employing Inconel 718 as the structural material to be protected. Barrier systems will include all metallic, metallic-to-ceramic, and, eventually, metallic/ceramic composites as the lamellae. Since space propulsion implies repetitive engine firings without earth-based inspection and repair, coating durability will be closely examined, and testing regimes will include repetitive thermal cycling to simulate damage accumulation. The target accomplishments include: generation of actual hydrogen permeation data for metallic, ceramic-metallic, and hybrid metallic/ceramic composition barrier systems, practically none of which is currently extant; definition of physical damage modes imported to barrier systems due to thermal cycling, both transient temperature profiles and steady-state thermal mismatch stress states being examined as sources of damage; and computational models that incorporate general laminate schemes as described above, including manufacturing realities such as porosity, and whatever defects are introduced through service and characterized during the experimental programs.

  16. EOP TDRs (Temperature-Depth-Recordings) Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature-depth-recorders (TDRs) were attached to commercial longline and research Cobb trawl gear to obtain absolute depth and temperature measurement during...

  17. Hydrogen bond dynamics at the water/hydrocarbon interface.

    Science.gov (United States)

    Chowdhary, Janamejaya; Ladanyi, Branka M

    2009-04-02

    The dynamics of hydrogen bond formation and breakage for water in the vicinity of water/hydrocarbon liquid interfaces is studied using molecular dynamics simulations. Several liquid alkanes are considered as the hydrocarbon phase in order to determine the effects of their chain length and extent of branching on the properties of the adjacent water phase. In addition to defining the interface location in terms of the laboratory-frame density profiles, the effects of interfacial fluctuations are considered by locating the interface in terms of the proximity of the molecules of the other phase. We find that the hydrogen bond dynamics of interfacial water is weakly influenced by the identity of the hydrocarbon phase and by capillary waves. In addition to calculating hydrogen bond time correlations, we examine how the hydrogen bond dynamics depend on local coordination and determine the extent of cooperativity in the population relaxation of the hydrogen bonds that a given molecule participates in. The contributions of translational diffusion and reorientation of molecular O-H bonds to the mechanism of hydrogen bond breakage and reformation are investigated. In previous work, we have shown that rotation of the principal axes of water is anisotropic at the interface and depends on the initial orientation of the molecule relative to the interface. Here, we extend this analysis to the reorientation of the O-H vector and to hydrogen bond time correlation. We find that hydrogen bond dynamics are also sensitive to the initial orientation of the molecules participating in the hydrogen bond.

  18. Hydrogen Stark broadening by different kinds of model microfields

    Science.gov (United States)

    Seidel, J.

    1980-07-01

    A new model microfield is defined (the theta process) which in conjunction with the kangaroo process, is used to demonstrate the effects of different model microfields on hydrogen line profiles. The differences in the statistical features of the models give an estimate of the uncertainties associated with the method of model microfields. Stark broadening of hydrogen Lyman lines by either electrons or ions is investigated specifically.

  19. Dependence of signal on depth in transmission Raman spectroscopy.

    Science.gov (United States)

    Matousek, Pavel; Everall, Neil; Littlejohn, David; Nordon, Alison; Bloomfield, Matthew

    2011-07-01

    Recently, transmission Raman spectroscopy has been shown to be a valuable tool in the volumetric quantification of pharmaceutical formulations. In this work a Monte Carlo simulation and experimental study are performed to elucidate the dependence of the Raman signal on depth from the viewpoint of probing pharmaceutical tablets and powders in this experimental configuration. The transmission Raman signal is shown to exhibit a moderate bias toward the center of the tablets and this can be considerably reduced by using a recently developed Raman signal-enhancing concept, the "photon diode." The enhancing element not only reduces the bias but also increases the overall Raman signal intensity and consequently improves the signal-to-noise ratio of the measured spectrum. Overall, its implementation with appropriately chosen reflectivity results in a more uniform volumetric sampling across the half of the tablet where the photon diode is used (or across the tablet's entire depth if two photon diodes are used on each side of tablet) and enhanced overall sensitivity. These findings are substantiated experimentally on a segmented tablet by inserting a poly(ethelyne terephthalate) (PET) film doped with TiO(2) at different depths and monitoring its contribution to the overall transmission Raman signal from the segmented tablet. The numerical simulations also indicate considerable sensitivity of the overall Raman signal to the absorption of the sample, which is in line with large migration distances traversed by photons in these measurements. The presence of sample absorption was shown numerically to reduce the signal enhancement effect while the overall depth-dependence profile remained broadly unchanged. The absorption was also shown to produce a depth profile with the photon diode similar to that without it, although with a reduced absolute intensity of Raman signals and diminished enhancement effect.

  20. Rank order scaling of pictorial depth

    NARCIS (Netherlands)

    Van Doorn, A.; Koenderink, J.; Wagemans, J.

    2011-01-01

    We address the topic of “pictorial depth” in cases of pictures that are unlike photographic renderings. The most basic measure of “depth” is no doubt that of depth order. We establish depth order through the pairwise depth-comparison method, involving all pairs from a set of 49 fiducial points. The

  1. Aeration equipment for small depths

    Directory of Open Access Journals (Sweden)

    Sluše Jan

    2015-01-01

    Full Text Available Deficit of air in water causes complications with cyanobacteria mainly in the summer months. Cyanobacteria is a bacteria that produces poison called cyanotoxin. When the concentration of cyanobacteria increases, the phenomena „algal bloom“ appears, which is very toxic and may kill all the organisms. This article describes new equipment for aeration of water in dams, ponds and reservoirs with small depth. This equipment is mobile and it is able to work without any human factor because its control is provided by a GPS module. The main part of this equipment consists of a floating pump which pumps water from the surface. Another important part of this equipment is an aerator where water and air are blended. Final aeration process runs in the nozzles which provide movement of all this equipment and aeration of the water. Simulations of the flow are solved by multiphase flow with diffusion in open source program called OpenFOAM. Results will be verified by an experiment.

  2. A local energy market for electricity and hydrogen

    DEFF Research Database (Denmark)

    Xiao, Yunpeng; Wang, Xifan; Pinson, Pierre

    2017-01-01

    ), loads, hydrogen vehicles (HVs), and a hydrogen storage system (HSS) operated by a HSS agent (HSSA). An iterative LEM clearing method is proposed based on the merit order principle. Players submit offers/bids with consideration of their own preferences and profiles according to the utility functions......The proliferation of distributed energy resources entails efficient market mechanisms in distribution-level networks. This paper establishes a local energy market (LEM) framework in which electricity and hydrogen are traded. Players in the LEM consist of renewable distributed generators (DGs....... Sensitivity analysis is then implemented to discuss the influences on the LEM clearing results of capacities of DGs, Loads, and the HSS, as well as price of hydrogen from the hydrogen station (HS)....

  3. The hydrogen highway

    Energy Technology Data Exchange (ETDEWEB)

    Grigg, A. [Fuel Cells Canada, Vancouver, British Columbia (Canada)

    2004-07-01

    'Full text:' The Hydrogen Highway in British Columbia, Canada, is a coordinated, large-scale demonstration and deployment program aimed at accelerating the commercialization of hydrogen and fuel cell technologies and products. It will be a showcase for fuel cell vehicles, refuelling stations and stationary power systems leading up to the 2010 Olympic and Paralympic Winter Games in Whistler, BC. The Hydrogen Highway is designed to help address many of the challenges to commercialization identified in the Canadian Fuel Cell Commercialization Roadmap. The project will create an early adopter network of hydrogen and fuel cell microenvironments where technology developers and users can learn about the technical, economic, environmental and social impacts of products. The Hydrogen Highway will give the public and potential purchasers an opportunity to feel, touch and see the new technology, as well as provide the industry with a venue in which to develop industry standards and supply chains of materials and components. While demonstration and deployment programs are a recognized and necessary component in the process to commercialize hydrogen and fuel cell technologies, there is no handbook describing how it should be done. This paper will describe the history, objectives, project details and some of the challenges associated with establishing Canada's Hydrogen Highway. (author)

  4. Photoelectrochemical hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Rocheleau, R.; Misra, A.; Miller, E. [Univ. of Hawaii, Honolulu, HI (United States)

    1998-08-01

    A significant component of the US DOE Hydrogen Program is the development of a practical technology for the direct production of hydrogen using a renewable source of energy. High efficiency photoelectrochemical systems to produce hydrogen directly from water using sunlight as the energy source represent one of the technologies identified by DOE to meet this mission. Reactor modeling and experiments conducted at UH provide strong evidence that direct solar-to-hydrogen conversion efficiency greater than 10% can be expected using photoelectrodes fabricated from low-cost, multijunction (MJ) amorphous silicon solar cells. Solar-to-hydrogen conversion efficiencies as high as 7.8% have been achieved using a 10.3% efficient MJ amorphous silicon solar cell. Higher efficiency can be expected with the use of higher efficiency solar cells, further improvement of the thin film oxidation and reduction catalysts, and optimization of the solar cell for hydrogen production rather than electricity production. Hydrogen and oxygen catalysts developed under this project are very stable, exhibiting no measurable degradation in KOH after over 13,000 hours of operation. Additional research is needed to fully optimize the transparent, conducting coatings which will be needed for large area integrated arrays. To date, the best protection has been afforded by wide bandgap amorphous silicon carbide films.

  5. Diffusion and impurity segregation in hydrogen-implanted silicon carbide

    Energy Technology Data Exchange (ETDEWEB)

    Barcz, A., E-mail: barcz@ite.waw.pl [Institute of Electron Technology, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Institute of Physics, Polish Academy of Sciences, 02-668 Warsaw (Poland); Kozubal, M.; Ratajczak, J.; Gołaszewska, K. [Institute of Electron Technology, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Jakieła, R.; Dyczewski, J.; Wojciechowski, T. [Institute of Physics, Polish Academy of Sciences, 02-668 Warsaw (Poland); Celler, G. K. [Institute for Advanced Materials, Devices, and Nanotechnology (IAMDN)/Department of Materials Science and Engineering, Rutgers University, New Brunswick, New Jersey 08901 (United States)

    2014-06-14

    Diffusion and segregation behavior of hydrogen and oxygen in silicon carbide subjected to H implantation and subsequent annealing were studied with a number of analytical techniques including Secondary Ion Mass Spectrometry (SIMS), Rutherford backscattering spectrometry in channeling geometry, field emission scanning electron microscopy, optical microscopy, cross-sectional transmission electron microscopy, and atomic force microscopy. H{sup +} implantation was carried out with energies of 200 keV, 500 keV, or 1 MeV to doses of 1 × 10{sup 16}, 1 × 10{sup 17}, or 2 × 10{sup 17} ion/cm{sup 2}, and thermal treatment was conducted in flowing argon for 1 to 2 h at temperatures of 740, 780, 1000, or 1100 °C. The process of migration and eventual loss of hydrogen in a point defect regime is postulated to proceed to a large extent through ionized vacancies. This conclusion was derived from the observed substantial difference in H mobilities in n- vs. p-type SiC as the population of ionized vacancies is governed by the Fermi-Dirac statistics, i.e., the position of the Fermi level. For higher doses, a well defined buried planar zone forms in SiC at the maximum of deposited energy, comprising numerous microvoids and platelets that are trapping sites for hydrogen atoms. At a certain temperature, a more or less complete exfoliation of the implanted layer is observed. For a 1 MeV implant heated to 1100 °C in nominally pure argon, SIMS profiling reveals a considerable oxygen peak of 10{sup 16} O atoms/cm{sup 2} situated at a depth close to that of the peak of the implanted H{sup +}. Similarly, 1100 °C annealing of a 200 keV implant induces the formation of a thin oxide (4 nm), located at the interface between the implanted layer and the substrate as evidenced by both SIMS and HRTEM. The measurements were taken on the part of the sample that remained un-exfoliated. In view of a lack of convincing evidence that a hexagonal SiC might contain

  6. Reference sound speed profile and related ray acoustics of Bay of Bengal for tomographic studies

    Digital Repository Service at National Institute of Oceanography (India)

    PrasannaKumar, S.; Murty, T.V.R.; Somayajulu, Y.K.; Chodankar, P.V.; Murty, C.S.

    Using the archived hydrographic data, a climatological mean sound speed profile has been developed for the Bay of Bengal which will serve as an input (reference profile) to acoustic models. This profile is depth limited with the effective acoustic...

  7. A green hydrogen economy

    Energy Technology Data Exchange (ETDEWEB)

    Clark, W.W. II [Clark Communications, Beverly Hills, CA (United States). Green Hydrogen Scientific Advisory Committee; Rifkin, J. [The Foundation on Economic Trends (United States)

    2006-11-15

    This paper is the result of over a dozen scholars and practitioners who strongly felt that a hydrogen economy and hence the future is closer than some American politicians and bureaucrats state. Moreover, when seen internationally, there is strong evidence, the most recent and obvious ones are the proliferation of hybrid vehicles, that for any nation-state to be energy independent it must seek a renewable or green hydrogen future in the near term. The State of California has once again taken the lead in this effort for both an energy-independent future and one linked strongly to the hydrogen economy. Then why a hydrogen economy in the first instance? The fact is that hydrogen most likely will not be used for refueling of vehicles in the near term. The number of vehicles to make hydrogen commercially viable will not be in the mass market by almost all estimates until 2010. However, it is less than a decade away. The time frame is NOT 30-40 years as some argue. The hydrogen economy needs trained people, new ventures and public-private partnerships now. The paper points out how the concerns of today, including higher costs and technologies under development, can be turned into opportunities for both the public and private sectors. It was not too long ago that the size of a mobile phone was that of a briefcase, and then almost 10 years ago, the size of a shoe box. Today, they are not only the size of a man's wallet but also often given away free to consumers who subscribe or contract for wireless services. While hydrogen may not follow this technological commercialization exactly, it certainly will be on a parallel path. International events and local or regional security dictate that the time for a hydrogen must be close at hand. (author)

  8. Photobiological hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Seibert, M; Lien, S; Weaver, P F

    1979-01-01

    Hydrogen production by phototrophic organisms, which has been known since the 1930's, occurs at the expense of light energy and electron-donating substrates. Three classes of organisms, namely, photosynthetic bacteria, cyanobacteria, and algae carry out this function. The primary hydrogen-producing enzyme systems, hydrogenase and nitrogenase, will be discussed along with the manner in which they couple to light-driven electron transport. In addition, the feasibility of using in vivo and in vitro photobiological hydrogen producing systems in future solar energy conversion applications will be examined.

  9. Photobiological hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Seibert, M.; Lien, S.; Weaver, P.F.

    1979-01-01

    Hydrogen production by phototrophic organisms, which has been known since the 1930's, occurs at the expense of light energy and electron-donating substrates. Three classes of organisms, namely, photosynthetic bacteria, cyanobacteria, and algae carry out this function. The primary hydrogen-producing enzyme systems, hydrogenase and nitrogenase, will be discussed along with the manner in which they couple to light-driven electron transport. In addition, the feasibility of using in vivo and in vitro photobiological hydrogen producing systems in future solar energy conversion applications will be examined.

  10. Biological hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Benemann, J.R. [Univ. of California, Berkeley, CA (United States)

    1995-11-01

    Biological hydrogen production can be accomplished by either thermochemical (gasification) conversion of woody biomass and agricultural residues or by microbiological processes that yield hydrogen gas from organic wastes or water. Biomass gasification is a well established technology; however, the synthesis gas produced, a mixture of CO and H{sub 2}, requires a shift reaction to convert the CO to H{sub 2}. Microbiological processes can carry out this reaction more efficiently than conventional catalysts, and may be more appropriate for the relatively small-scale of biomass gasification processes. Development of a microbial shift reaction may be a near-term practical application of microbial hydrogen production.

  11. Chromatographic hydrogen isotope separation

    Science.gov (United States)

    Aldridge, Frederick T.

    1981-01-01

    Intermetallic compounds with the CaCu.sub.5 type of crystal structure, particularly LaNiCo.sub.4 and CaNi.sub.5, exhibit high separation factors and fast equilibrium times and therefore are useful for packing a chromatographic hydrogen isotope separation colum. The addition of an inert metal to dilute the hydride improves performance of the column. A large scale mutli-stage chromatographic separation process run as a secondary process off a hydrogen feedstream from an industrial plant which uses large volumes of hydrogen can produce large quantities of heavy water at an effective cost for use in heavy water reactors.

  12. Color Changing Hydrogen Sensors

    Science.gov (United States)

    Roberson, Luke B.; Williams, Martha; Captain, Janine E.; Mohajeri, Nahid; Raissi, Ali

    2015-01-01

    During the Space Shuttle Program, one of the most hazardous operation that occurred was the loading of liquid hydrogen (LH2) during fueling operations of the spacecraft. Due to hydrogen's low explosive limit, any amount leaked could lead to catastrophic event. Hydrogen's chemical properties make it ideal as a rocket fuel; however, the fuel is deemed unsafe for most commercial use because of the inability to easily detect the gas leaking. The increased use of hydrogen over traditional fossil fuels would reduce greenhouse gases and America's dependency on foreign oil. Therefore a technology that would improve safety at NASA and in the commercial sector while creating a new economic sector would have a huge impact to NASA's mission. The Chemochromic Detector for sensing hydrogen gas leakage is a color-changing detector that is useful in any application where it is important to know not only the presence but also the location of the hydrogen gas leak. This technology utilizes a chemochromicpigment and polymer matrix that can be molded or spun into rigid or pliable shapes useable in variable temperature environments including atmospheres of inert gas, hydrogen gas, or mixtures of gases. A change in color of the detector material indicates where gaseous hydrogen leaks are occurring. The irreversible sensor has a dramatic color change from beige to dark grey and remains dark grey after exposure. A reversible pigment changes from white to blue in the presence of hydrogen and reverts back to white in the presence of oxygen. Both versions of the sensor's pigments were comprised of a mixture of a metal oxide substrate and a hydro-chromic compound (i.e., the compound that changed color in the presence of hydrogen) and immediately notified the operator of the presence of low levels of hydrogen. The detector can be used in a variety of formats including paint, tape, caulking, injection molded parts, textiles and fabrics, composites, and films. This technology brings numerous

  13. National hydrogen energy roadmap

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2002-11-01

    This report was unveiled by Energy Secretary Spencer Abraham in November 2002 and provides a blueprint for the coordinated, long-term, public and private efforts required for hydrogen energy development. Based on the results of the government-industry National Hydrogen Energy Roadmap Workshop, held in Washington, DC on April 2-3, 2002, it displays the development of a roadmap for America's clean energy future and outlines the key barriers and needs to achieve the hydrogen vision goals defined in

  14. Biomimetic hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Krassen, Henning

    2009-05-15

    Hydrogenases catalyze the reduction of protons to molecular hydrogen with outstanding efficiency. An electrode surface which is covered with active hydrogenase molecules becomes a promising alternative to platinum for electrochemical hydrogen production. To immobilize the hydrogenase on the electrode, the gold surface was modified by heterobifunctional molecules. A thiol headgroup on one side allowed the binding to the gold surface and the formation of a self-assembled monolayer. The other side of the molecules provided a surface with a high affinity for the hydrogenase CrHydA1 from Chlamydomonas reinhardtii. With methylviologen as a soluble energy carrier, electrons were transferred from carboxy-terminated electrodes to CrHydA1 and conducted to the active site (H-cluster), where they reduce protons to molecular hydrogen. A combined approach of surface-enhanced infrared absorption spectroscopy, gas chromatography, and surface plasmon resonance allowed quantifying the hydrogen production on a molecular level. Hydrogen was produced with a rate of 85 mol H{sub 2} min{sup -1} mol{sup -1}. On a 1'- benzyl-4,4'-bipyridinum (BBP)-terminated surface, the electrons were mediated by the monolayer and no soluble electron carrier was necessary to achieve a comparable hydrogen production rate (approximately 50% of the former system). The hydrogen evolution potential was determined to be -335 mV for the BBP-bound hydrogenase and -290 mV for the hydrogenase which was immobilized on a carboxy-terminated mercaptopropionic acid SAM. Therefore, both systems significantly reduce the hydrogen production overpotential and allow electrochemical hydrogen production at an energy level which is close to the commercially applied platinum electrodes (hydrogen evolution potential of -270 mV). In order to couple hydrogen production and photosynthesis, photosystem I (PS1) from Synechocystis PCC 6803 and membrane-bound hydrogenase (MBH) from Ralstonia eutropha were bound to each other

  15. Hydrogen utilization potential in subsurface sediments

    Directory of Open Access Journals (Sweden)

    Rishi Ram Adhikari

    2016-01-01

    Full Text Available Subsurface microbial communities undertake many terminal electron-accepting processes, often simultaneously. Using a tritium-based assay, we measured the potential hydrogen oxidation catalyzed by hydrogenase enzymes in several subsurface sedimentary environments (Lake Van, Barents Sea, Equatorial Pacific and Gulf of Mexico with different predominant electron-acceptors. Hydrogenases constitute a diverse family of enzymes expressed by microorganisms that utilize molecular hydrogen as a metabolic substrate, product or intermediate. The assay reveals the potential for utilizing molecular hydrogen and allows qualitative detection of microbial activity irrespective of the predominant electron-accepting process. Because the method only requires samples frozen immediately after recovery, the assay can be used for identifying microbial activity in subsurface ecosystems without the need to preserve live material.We measured potential hydrogen oxidation rates in all samples from multiple depths at several sites that collectively span a wide range of environmental conditions and biogeochemical zones. Potential activity normalized to total cell abundance ranges over five orders of magnitude and varies, dependent upon the predominant terminal electron acceptor. Lowest per-cell potential rates characterize the zone of nitrate reduction and highest per-cell potential rates occur in the methanogenic zone. Possible reasons for this relationship to predominant electron acceptor include (i increasing importance of fermentation in successively deeper biogeochemical zones and (ii adaptation of H2ases to successively higher concentrations of H2 in successively deeper zones.

  16. Hydrogen Utilization Potential in Subsurface Sediments.

    Science.gov (United States)

    Adhikari, Rishi R; Glombitza, Clemens; Nickel, Julia C; Anderson, Chloe H; Dunlea, Ann G; Spivack, Arthur J; Murray, Richard W; D'Hondt, Steven; Kallmeyer, Jens

    2016-01-01

    Subsurface microbial communities undertake many terminal electron-accepting processes, often simultaneously. Using a tritium-based assay, we measured the potential hydrogen oxidation catalyzed by hydrogenase enzymes in several subsurface sedimentary environments (Lake Van, Barents Sea, Equatorial Pacific, and Gulf of Mexico) with different predominant electron-acceptors. Hydrogenases constitute a diverse family of enzymes expressed by microorganisms that utilize molecular hydrogen as a metabolic substrate, product, or intermediate. The assay reveals the potential for utilizing molecular hydrogen and allows qualitative detection of microbial activity irrespective of the predominant electron-accepting process. Because the method only requires samples frozen immediately after recovery, the assay can be used for identifying microbial activity in subsurface ecosystems without the need to preserve live material. We measured potential hydrogen oxidation rates in all samples from multiple depths at several sites that collectively span a wide range of environmental conditions and biogeochemical zones. Potential activity normalized to total cell abundance ranges over five orders of magnitude and varies, dependent upon the predominant terminal electron acceptor. Lowest per-cell potential rates characterize the zone of nitrate reduction and highest per-cell potential rates occur in the methanogenic zone. Possible reasons for this relationship to predominant electron acceptor include (i) increasing importance of fermentation in successively deeper biogeochemical zones and (ii) adaptation of H2ases to successively higher concentrations of H2 in successively deeper zones.

  17. Rank order scaling of pictorial depth.

    Science.gov (United States)

    van Doorn, Andrea; Koenderink, Jan; Wagemans, Johan

    2011-01-01

    We address the topic of "pictorial depth" in cases of pictures that are unlike photographic renderings. The most basic measure of "depth" is no doubt that of depth order. We establish depth order through the pairwise depth-comparison method, involving all pairs from a set of 49 fiducial points. The pictorial space for this study was evoked by a capriccio (imaginary landscape) by Francesco Guardi (1712-1793). In such a drawing pictorial space is suggested by the artist through a small set of conventional depth cues. As a result typical Western observers tend to agree largely in their visual awareness when looking at such art. We rank depths for locations that are not on a single surface and far apart in pictorial space. We find that observers resolve about 40 distinct depth layers and agree largely in this. From a previous experiment we have metrical data for the same observers. The rank correlations between the results are high. Perhaps surprisingly, we find no correlation between the number of distinct depth layers and the total metrical depth range. Thus, the relation between subjective magnitude and discrimination threshold fails to hold for pictorial depth.

  18. Bayesian depth estimation from monocular natural images.

    Science.gov (United States)

    Su, Che-Chun; Cormack, Lawrence K; Bovik, Alan C

    2017-05-01

    Estimating an accurate and naturalistic dense depth map from a single monocular photographic image is a difficult problem. Nevertheless, human observers have little difficulty understanding the depth structure implied by photographs. Two-dimensional (2D) images of the real-world environment contain significant statistical information regarding the three-dimensional (3D) structure of the world that the vision system likely exploits to compute perceived depth, monocularly as well as binocularly. Toward understanding how this might be accomplished, we propose a Bayesian model of monocular depth computation that recovers detailed 3D scene structures by extracting reliable, robust, depth-sensitive statistical features from single natural images. These features are derived using well-accepted univariate natural scene statistics (NSS) models and recent bivariate/correlation NSS models that describe the relationships between 2D photographic images and their associated depth maps. This is accomplished by building a dictionary of canonical local depth patterns from which NSS features are extracted as prior information. The dictionary is used to create a multivariate Gaussian mixture (MGM) likelihood model that associates local image features with depth patterns. A simple Bayesian predictor is then used to form spatial depth estimates. The depth results produced by the model, despite its simplicity, correlate well with ground-truth depths measured by a current-generation terrestrial light detection and ranging (LIDAR) scanner. Such a strong form of statistical depth information could be used by the visual system when creating overall estimated depth maps incorporating stereopsis, accommodation, and other conditions. Indeed, even in isolation, the Bayesian predictor delivers depth estimates that are competitive with state-of-the-art "computer vision" methods that utilize highly engineered image features and sophisticated machine learning algorithms.

  19. Chemical changes in PMMA as a function of depth due to proton beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Szilasi, S.Z., E-mail: szilasi@atomki.hu [Institute of Nuclear Research of the Hungarian Academy of Sciences, H-4026 Debrecen Bem ter 18/c, H-4001 Debrecen, P.O. Box 51 (Hungary); Huszank, R. [Institute of Nuclear Research of the Hungarian Academy of Sciences, H-4026 Debrecen Bem ter 18/c, H-4001 Debrecen, P.O. Box 51 (Hungary); Szikra, D. [University of Debrecen, Institute of Nuclear Medicine, H-4032 Debrecen, Nagyerdei krt. 98 (Hungary); Vaczi, T. [Institute for Nanotechnology, Bay Zoltan Foundation for Applied Research, H-3515 Miskolc-Egyetemvaros, P.O. Box 46 (Hungary); Rajta, I. [Institute of Nuclear Research of the Hungarian Academy of Sciences, H-4026 Debrecen Bem ter 18/c, H-4001 Debrecen, P.O. Box 51 (Hungary); Nagy, I. [Department of Physical Chemistry, University of Debrecen, P.O. Box 7, H-4010 Debrecen (Hungary)

    2011-10-17

    Highlights: {yields} Chemical changes were investigated as a function of depth in proton irradiated PMMA {yields} The depth profile of numerous functional groups was determined along the depth {yields} The degree of chemical modification strongly depends on the LET of protons {yields} At low-fluences the zone of maximal modification is restricted to the Bragg peak {yields} At higher fluences the zone of max. modification extends towards the sample surface. - Abstract: In this work we determined depth profiles of the chemical change in PMMA irradiated with 2 MeV protons by infrared spectroscopic and micro-Raman measurements. The measurements were carried out on 10 {mu}m thin stacked foil samples using an infrared spectrometer in universal attenuated total reflectance (UATR) and transmission modes; while the thick samples were analyzed with a confocal micro-Raman spectrometer. The depth profiles of the changes formed due to the various delivered fluences were compared to each other. The measurements show the strong dependence of the degree of modification on the energy transfer from the decelerating protons. Depth profiles reveal that at the fluences applied in this work the entire irradiated volume suffered some chemical modifications. In case of low-fluence samples the zone of maximal modification is restricted only to the Bragg peak, but with increasing fluences the region of maximal modification extends towards the sample surface.

  20. Measuring stress variation with depth using Barkhausen signals

    Energy Technology Data Exchange (ETDEWEB)

    Kypris, O., E-mail: orfeas.kypris@cs.ox.ac.uk [Department of Computer Science, University of Oxford, Oxford OX13QD (United Kingdom); Nlebedim, I.C.; Jiles, D.C. [Department of Electrical and Computer Engineering, Iowa State University, Ames, IA 50011 (United States)

    2016-06-01

    Magnetic Barkhausen noise analysis (BNA) is an established technique for the characterization of stress in ferromagnetic materials. An important application is the evaluation of residual stress in aerospace components, where shot-peening is used to strengthen the part by inducing compressive residual stresses on its surface. However, the evaluation of the resulting stress-depth gradients cannot be achieved by conventional BNA methods, where signals are interpreted in the time domain. The immediate alternative of using x-ray diffraction stress analysis is less than ideal, as the use of electropolishing to remove surface layers renders the part useless after inspection. Thus, a need for advancing the current BNA techniques prevails. In this work, it is shown how a parametric model for the frequency spectrum of Barkhausen emissions can be used to detect variations of stress along depth in ferromagnetic materials. Proof of concept is demonstrated by inducing linear stress-depth gradients using four-point bending, and fitting the model to the frequency spectra of measured Barkhausen signals, using a simulated annealing algorithm to extract the model parameters. Validation of our model suggests that in bulk samples the Barkhausen frequency spectrum can be expressed by a multi-exponential function with a dependence on stress and depth. One practical application of this spectroscopy method is the non-destructive evaluation of residual stress-depth profiles in aerospace components, thus helping to prevent catastrophic failures. - Highlights: • The frequency spectrum of Barkhausen noise is modelled as a function of bending moment. • Experimental results demonstrate the sensitivity of the slope parameter to a bending moment. • This allows extraction of the stress-depth characteristic in ferromagnetic specimens.