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Sample records for bet surface area

  1. Characterization of pigment-leached antifouling coatings using BET surface area measurements and mercury porosimetry

    DEFF Research Database (Denmark)

    Kiil, Søren; Dam-Johansen, Kim

    2007-01-01

    In this work BET surface area measurements and mercury porosimetry are used to characterize leached layers formed when seawater-soluble pigments (Cu2O and ZnO) dissolve during accelerated leaching of simple antifouling coatings. Measurements on single-pigment coatings show that an increasing...... fraction of Cu2O or ZnO pigment particles becomes unavailable for dissolution when the concentration of the pigment decreases in the coating and the interparticle distance in the binder matrix becomes larger. Experimental data for a coating initially containing a mixture of Cu2O and TiO2 pigments suggest...... that a substantial fraction of the smaller and inert TiO2 particles may be lost from the coating upon dissolution of the larger Cu2O particles. This inert particle translocation effect is important to take into account when interpreting polishing and leaching data and when developing mathematical models...

  2. BET surface area distributions in polar stream sediments: Implications for silicate weathering in a cold-arid environment

    Science.gov (United States)

    Marra, Kristen R.; Elwood Madden, Megan E; Soreghan, Gerilyn S.; Hall, Brenda L

    2014-01-01

    BET surface area values are critical for quantifying the amount of potentially reactive sediments available for chemical weathering and ultimately, prediction of silicate weathering fluxes. BET surface area values of fine-grained (glacier surfaces, where dust is trapped and subsequently liberated during summer melting. Additionally, variations in stream discharge rate, which mobilizes sediment in pulses and influences water:rock ratios, the origin and nature of the underlying drift material, and the contribution of organic acids may play significant roles in the production and mobilization of high-surface area sediment. This study highlights the presence of sediments with high surface area in cold-based glacier systems, which influences models of chemical denudation rates and the impact of glacial systems on the global carbon cycle.

  3. Optimum BET surface areas for activated carbon produced from textile sewage sludges and its application as dye removal.

    Science.gov (United States)

    Kacan, Erdal

    2016-01-15

    The purpose of this experimental study is to determine optimum preparation conditions for activated carbons obtained from textile sewage sludge (TSS) for removal of dyes from aqueous solutions. The textile sewage sludge activated carbon (TSSAC) was prepared by chemical activation with potassium hydroxide using Response Surface Methodology (RSM). The most influential factor on each experimental design responses was identified via ANNOVA analysis. Based on the central composite design (CCD), quadratic model was developed to correlate the preparation variables for one response which is the Brunauer-Emmelt-Teller (BET) surface area. RSM based on a three-variable CCD was used to determine the effect of pyrolyzed temperature (400-700 °C), carbonization time (45-180 min) and KOH: weight of TSS (wt%) impregnation ratio (0.5:1-1.5:1) on BET surface area. According to the results, pyrolyzed temperature and impregnation ratio were found as the significant factors for maximizing the BET surface area. The major effect which influences the BET surface area was found as pyrolyzed temperature. Both carbonization time and impregnation ratio of KOH had no significant effect. The optimum conditions for preparing TSSAC, based on response surface and contour plots, were found as follows: pyrolyzed temperature 700 °C, carbonization time of 45 min and chemical impregnation ratio of 0.5. The maximum and optimum BET surface area of TSSAC were found as 336 m(2)/g and 310.62 m(2)/g, respectively. Synozol Blue reactive (RSB) and Setapers Yellow-Brown (P2RFL) industrial textile dyes adsorption capacities were investigated. As expected the TSSAC which has the biggest BET surface area (336 m(2)/g) adsorbed dye best. The maximum (RSB) and (P2RFL) uptake capacities were found as 8.5383 mg/g and 5.4 mg/g, respectively. The results of this study indicated the applicability of TSSAC for removing industrial dyes from aqueous solution.

  4. Specific Surface versus Electrochemically Active Area of the Carbon/Polypyrrole Capacitor: Correlation of Ion Dynamics Studied by an Electrochemical Quartz Crystal Microbalance with BET Surface.

    Science.gov (United States)

    Mosch, Heike L K S; Akintola, Oluseun; Plass, Winfried; Höppener, Stephanie; Schubert, Ulrich S; Ignaszak, Anna

    2016-05-10

    Carbon/polypyrrole (PPy) composites are promising electrode materials for energy storage applications such as lightweight capacitors. Although these materials are composed of relatively inexpensive components, there is a gap of knowledge regarding the correlation between surface, porosity, ion exchange dynamics, and the interplay of the double layer capacitance and pseudocapacitance. In this work we evaluate the specific surface area analyzed by the BET method and the area accessible for ions using electrochemical quartz-crystal microbalance (EQCM) for SWCNT/PPy and carbon black Vulcan XC72-R/PPy composites. The study revealed that the polymer has significant influence on the pore size of the composites. Although the BET surface is low for the polypyrrole, the electrode mass change and thus the electrochemical area are large for the polymer-containing electrodes. This indicates that multiple redox active centers in the charged polymer chain are good ion scavengers. Also, for the composite electrodes, the effective charge storage occurs at the polypyrrole-carbon junctions, which are easy to design/multiply by a proper carbon-to-polymer weight ratio. The specific BET surface and electrochemically accessible surface area are both important parameters in calculation of the electrode capacitance. SWCNTs/PPy showed the highest capacitances normalized to the BET and electrochemical surface as compared to the polymer-carbon black. TEM imaging revealed very homogeneous distribution of the nanosized polymer particles onto the CNTs, which facilitates the synergistic effect of the double layer capacitance (CNTs) and pseudocapacitance (polymer). The trend in the electrode mass change in correlation with the capacitance suggest additional effects such as a solvent co-insertion into the polymer and the contribution of the charge associated with the redox activity of oxygen-containing functional groups on the carbon surface.

  5. THE EFFECT OF STORAGE AT AMBIENT HUMIDITY ON THE BET-SPECIFIC SURFACE-AREA OF TABLETS COMPACTED FROM DIFFERENT MATERIALS

    NARCIS (Netherlands)

    RIEPMA, KA; DEKKER, BG; JAGER, RS; ELBERSE, PA; LERK, CF

    1993-01-01

    Tablets compacted from both water soluble and water insoluble particulate solids showed no change in BET-specific surface area when transferred immediately after ejection from the die in a dry atmosphere. Storage at ambient humidity resulted in an irreversible decrease in surface area, caused by cap

  6. Effect of BET surface area of recycled U{sub 3}O{sub 8} powder on Mn-Al doped UO{sub 2} pellets property

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Jang Soo; Yang, Jae Ho; Kim, Dongjoo; Kim, Jong Hun; Rhee, Young Woo; Kim, Keon Sik; Koo, Yang Hyun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-05-15

    Research on fuel pellets focuses on increasing the pellet density and grain size to increase the uranium contents and the high burn-up safety margins for LWRs. In the commercial manufacturing of UO{sub 2} fuel pellets, defective UO{sub 2} pellets that do not meet the manufacturing specifications of density and diameter may be produced. Defective UO{sub 2} pellets or scraps of pellets should be reused in manufacturing new UO{sub 2} pellets. A commonly used recycling method for defective UO{sub 2} pellets or scraps of pellets is that defective UO{sub 2} pellets are oxidized in air at about 450 .deg. C to make U{sub 3}O{sub 8} powder and then added to UO{sub 2} powder. Because the recycled U{sub 3}O{sub 8} powder has a low sinter-ability compared to the raw UO{sub 2} powder, addition of U{sub 3}O{sub 8} to UO{sub 2} leads to a drop in the pellet density, impeding a grain growth and the formation of undesired graph-like pore segregates. This adverse effect of recycled U{sub 3}O{sub 8} powder on UO{sub 2} pellet property becomes more severe in large grain sized UO{sub 2} pellets. In general, the sinter-active powder should have small size and large BET surface area. However, since the powder property of U{sub 3}O{sub 8} depends on the initial grain size of UO{sub 2} pellets, larger grain UO{sub 2} pellet produces poorer sinter-active U{sub 3}O{sub 8} powders having larger particle size and smaller BET surface area. In this paper, the effects of several process parameters on U{sub 3}O{sub 8} powder properties have been tested. It is suggested that BET surface area of recycled U{sub 3}O{sub 8} powder can be increased by applying low temperature oxidation and/or sequential cyclic thermal treatment procedures. The effect of those recycled U{sub 3}O{sub 8} powder on the UO{sub 2} pellet properties is also investigated. The U{sub 3}O{sub 8} powders having higher BET surface area can mitigate the UO{sub 2} pellet density drop.

  7. Surface area and volume measurements of volcanic ash particles using micro-computed tomography (micro-CT): A comparison with scanning electron microscope (SEM) stereoscopic imaging and Brunauer-Emmett-Teller (BET) model

    Science.gov (United States)

    Ersoy, Orkun; Şen, Erdal; Aydar, Erkan; Tatar, Ä.°Lkan; Ćelik, H. Hamdi

    2010-05-01

    Volcanic ash particles are important components of explosive eruptions and their surface texture is the subject of intense research. Characterization of ash surfaces is crucial for understanding the physics of the volcanic plumes, remote sensing measurements of ash and aerosols, interfacial processes, modelling transportation and deposition of tephra and characterizing eruptive styles. A number of different methods have been used over the years to arrive at surface area estimates. The more common methods include estimates based on the geometric considerations (geometric surface area) and the physisorption of gas molecules on the surface of interest (physical surface area). In this study, micro computed tomography (micro-CT), a non-destructive method providing three-dimensional data enabled the measurement of surface areas and volumes of individual ash particles. Specific surface area estimates for ash particles were also obtained using nitrogen as gas adsorbent and the BET (Brunauer-Emmett-Teller) model. Results were compared with the values obtained from SEM stereoscopic imaging and geometric considerations. Surface area estimates of micro-CT and SEM stereoscopic imaging overlaps with mean specific surface area results of 0.0167 and 0.0214 m2/g, respectively. However, ash particle surface textures present quite a deviation from that of their geometric forms and approximation to sphere and ellipsoid both seemed to be inadequate for representation of real ash surfaces. The higher surface area estimate (> 0.4 m2/g) obtained from the technique based on physical sorption of gases (BET model here) was attributed to its capability for surface areas associated even with angstrom-sized pores. SEM stereoscopic and/or micro-CT imaging were suggested for characterization of textures on macro-pore regions of ash particles.

  8. A theory of multilayer adsorption on rough surfaces in terms of clustering and melting BET piles

    Science.gov (United States)

    Cerofolini, G. F.; Meda, L.

    1998-10-01

    An equation is proposed on theoretical grounds for the description of equilibrium adsorption of vapours below their critical temperature on solid adsorbents. Like in the Brunauer-Emmett-Teller (BET) theory, each surface site is described as the origin of an adsorbed pile; differently from the BET theory, however, the piles are allowed to undergo a branching process when the equilibrium pressure is increased; vapour condensation is assumed to occur when all the available space is filled. This growth is described by an isotherm behaving as the BET equation in the monolayer region, as the Anderson or Brunauer-Skalny-Bodor extension of the BET equation just above the monolayer, and as the Frenkel-Halsey-Hill equation at higher coverage. For suitable choice of its free parameters, the proposed equation accounts for all isotherms of type I, II and III of Brunauer classification.

  9. BET measurements: Outgassing of minerals

    DEFF Research Database (Denmark)

    Clausen, Liselotte; Fabricius, Ida Lykke

    2000-01-01

    Outgassing minerals at elevated temperatures prior to BET measurements can lead to phase changes, especially in the case of amorphous and poorly crystalline materials. In order to evaluate the applicability of the BET method when low outgassing temperatures are required, selected aquifer minerals...... were outgassed at different temperatures and for different times. The studied minerals are 2-line ferrihydrite, goethite, lepidocrocite, quartz, calcite, ®-alumina, and kaolinite. The results demonstrate that measured specific surface areas of iron oxides are strongly dependent on outgassing conditions...... because the surface area increased by 170% with increasing temperature. In the poorly crystalline minerals, phase changes caused by heating were observed at temperatures lower than 100±C. Therefore low outgassing temperatures are preferable for minimizing phase changes. As demonstrated in this study...

  10. Rattleback bet

    Science.gov (United States)

    Dail, Steve

    2011-05-01

    A neat twist to the "rattleback" or "celt" demonstration was revealed to me after a "bet" with one of my AP® Physics students.2 I asked the class to try to explain what is responsible for the spinning piece of plastic to suddenly reverse its direction of spin. Some thought about air friction, others discussed the offset center of gravity. There are many online sources with detailed explanations, as well as in TPT,3 so I will not try to explain it here, but I felt that friction between the rattleback and the table definitely played a major role in the explanation. My student disagreed. The next day my student showed up to class with a small container of Vaseline and declared, "We will settle this right now. Let's grease up a lab table and spin the rattleback and see what happens." (I wish all my students were this curious!) First, we spun the rattleback several times on a clean table to see the interesting spin reversal. Then after applying a thin layer of Vaseline to the table, we spun the rattleback. Try it yourself (or email me) to see who won the bet!

  11. Betting exchanges : the future of sports betting?

    NARCIS (Netherlands)

    Koning, Ruud H.; Velzen, B. van

    2009-01-01

    Sports betting and sports have always been strongly connected. Traditionally, these betting markets have been cleared by bookmakers, who accept bets on certain events. These bookmakers carry the risk of paying the amount wagered if the event occurs. Recently, a new type of betting market has appeare

  12. Determination of Reactive Surface Area of Melt Glass

    Energy Technology Data Exchange (ETDEWEB)

    Bourcier,W.L.; Roberts, S.; Smith, D.K.; Hulsey, S.; Newton,L.; Sawvel, A.; Bruton, C.; Papelis, C.; Um, W.; Russell, C. E.; Chapman,J.

    2000-10-01

    A comprehensive investigation of natural and manmade silicate glasses, and nuclear melt glass was undertaken in order to derive an estimate of glass reactive surface area. Reactive surface area is needed to model release rates of radionuclides from nuclear melt glass in the subsurface. Because of the limited availability of nuclear melt glasses, natural volcanic glass samples were collected which had similar textures and compositions as those of melt glass. A flow-through reactor was used to measure the reactive surface area of the analog glasses in the presence of simplified NTS site ground waters. A measure of the physical surface area of these glasses was obtained using the BET gas-adsorption method. The studies on analog glasses were supplemented by measurement of the surface areas of pieces of actual melt glass using the BET method. The variability of the results reflect the sample preparation and measurement techniques used, as well as textural heterogeneity inherent to these samples. Based on measurements of analog and actual samples, it is recommended that the hydraulic source term calculations employ a range of 0.001 to 0.01 m{sup 2}/g for the reactive surface area of nuclear melt glass.

  13. Manganese Dioxide with High Specific Surface Area for Alkaline Battery

    Institute of Scientific and Technical Information of China (English)

    HUANG You-ju; LIN Yu-li; LI Wei-shan

    2012-01-01

    The authors reported a facile method for the synthesis of manganese dioxide without any template and catalyst at a low-temperature.The prepared sample was characterized with X-ray diffraction(XRD),scanning electron microscopy(SEM),Brunauer-Emmett-Teller(BET) surface analysis,Fourier transform infrared(FTIR) spectrometry,cyclic voltammetry,altemative current(AC) impedance test and battery discharge test.It is found that the prepared sample belongs to α-MnO2 and has a microsphere morphology and a large BET surface area.The electrochemical characterization indicates that the prepared sample displays a larger electrochemical capacitance than the commercial electrolytic manganese dioxides(EMD) in Na2SO4 solution,and exhibits larger discharge capacity than EMD,especially at a high rate discharge condition when it is used as cathode of alkaline Zn/MnO2 battery.

  14. Epitope grafting, re-creating a conformational Bet v 1 antibody epitope on the surface of the homologous apple allergen Mal d 1

    DEFF Research Database (Denmark)

    Holm, Jens; Ferreras, Mercedes; Ipsen, Henrik;

    2011-01-01

    Birch-allergic patients often experience oral allergy syndrome upon ingestion of vegetables and fruits, most prominently apple, that is caused by antibody cross-reactivity of the IgE antibodies in patients to proteins sharing molecular surface structures with the major birch pollen group 1 allergen...... scaffold molecule without loss of epitope functionality. Furthermore, we show that increasing surface similarity to Bet v 1 of Mal d 1 variants by substitution of 6-8 residues increased the ability to trigger basophil histamine release with blood from birch-allergic patients not responding to natural Mal d...

  15. High surface area, high permeability carbon monoliths

    Energy Technology Data Exchange (ETDEWEB)

    Lagasse, R.R.; Schroeder, J.L. [Sandia National Labs., Albuquerque, NM (United States). Organic Materials Processing Dept.

    1994-12-31

    The goal of this work is to prepare carbon monoliths having precisely tailored pore size distribution. Prior studies have demonstrated that poly(acrylonitrile) can be processed into a precursor having tailored macropore structure. Since the macropores were preserved during pyrolysis, this synthetic process provided a route to porous carbon having macropores with size =0.1 to 10{mu}m. No micropores of size <2 nm could be detected in the carbon, however, by nitrogen adsorption. In the present work, the authors have processed a different polymer, poly(vinylidene chloride) into a macroporous precursor, Pyrolysis produced carbon monoliths having macropores derived from the polymer precursor as well as extensive microporosity produced during the pyrolysis of the polymer. One of these carbons had BET surface area of 1,050 m{sup 2}/g and about 1.2 cc/g total pore volume, with about 1/3 of the total pore volume in micropores and the remainder in 1{mu}m macropores. No mesopores in the intermediate size range could be detected by nitrogen adsorption. Carbon materials having high surface area as well as micron size pores have potential applications as electrodes for double layer supercapacitors containing liquid electrolyte, or as efficient media for performing chemical separations.

  16. Changes in expression of BetV1 allergen of silver birch pollen in urbanized area of Ukraine.

    Science.gov (United States)

    Žiarovská, Jana; Labajová, Mária; Ražná, Katarína; Bežo, Milan; Štefúnová, Veronika; Shevtsova, Tatiana; Garkava, Kateryna; Brindza, Ján

    2013-01-01

    The aim of the study was to determinate the level of expression of silver birch allergen Betv1 in pollen samples from different Ukraine areas by RT-qPCR SYBR Green assay. Protocol for quantifying the expression of Betv1 allergen was developed when testing of three housekeeping genes-cyclophylin, alpha-tubulin and transcription factor CBF1. Samples from urbanized area was analysed by real-time PCR when a sample from forest growth conditions was used as a calibrator. Real-time PCR based quantifying of Betv1 provides a useful method for rapid and sensitive analyses of this silver birch allergen. Our results show higher expression levels in samples from central parts of urbanized area as housing estates when compared to the samples from borders of the urbanized area.

  17. Surface area of lactose and lactose granulates on consolidation and compaction

    NARCIS (Netherlands)

    Riepma, Klaas Alouis

    1993-01-01

    This dissertation discusses the effect of short time storage at different conditions on the strength and the specific BET surface area of lactose tablets. In addition, some aspects are studied of the consolidation and compaction properties of crystalline lactose fractions in heterogeneous systems. T

  18. Metal-organic framework materials with ultrahigh surface areas

    Energy Technology Data Exchange (ETDEWEB)

    Farha, Omar K.; Hupp, Joseph T.; Wilmer, Christopher E.; Eryazici, Ibrahim; Snurr, Randall Q.; Gomez-Gualdron, Diego A.; Borah, Bhaskarjyoti

    2015-12-22

    A metal organic framework (MOF) material including a Brunauer-Emmett-Teller (BET) surface area greater than 7,010 m.sup.2/g. Also a metal organic framework (MOF) material including hexa-carboxylated linkers including alkyne bond. Also a metal organic framework (MOF) material including three types of cuboctahedron cages fused to provide continuous channels. Also a method of making a metal organic framework (MOF) material including saponifying hexaester precursors having alkyne bonds to form a plurality of hexa-carboxylated linkers including alkyne bonds and performing a solvothermal reaction with the plurality of hexa-carboxylated linkers and one or more metal containing compounds to form the MOF material.

  19. Synthesis and Characterization of Large Surface Area Yttrium Oxide by Precipitation Method

    Institute of Scientific and Technical Information of China (English)

    崔大立; 龙志奇; 张顺利; 崔梅生; 黄小卫

    2004-01-01

    The method for preparing yttrium oxide with large specific surface area was introduced. By means of BET, SEM, TG and DTA analysis, the effects of precipitant, stirring velocity, non-RE impurity in solution, calcination temperature, on the surface area were studied respectively. The Y2O3 sample with specific surface area of more than 60 m2*g-1 and L.O.I less than 1% was prepared in the suitable precipitation condition and calcinations temperature when the ammonia used as precipitant. The SEM shows that the Y2O3 prepared with large surface area is the aggregation of about 50 nm particles.

  20. Parimutuel Betting on Permutations

    CERN Document Server

    Agrawal, Shipra; Ye, Yinyu

    2008-01-01

    We focus on a permutation betting market under parimutuel call auction model where traders bet on the final ranking of n candidates. We present a Proportional Betting mechanism for this market. Our mechanism allows the traders to bet on any subset of the n x n 'candidate-rank' pairs, and rewards them proportionally to the number of pairs that appear in the final outcome. We show that market organizer's decision problem for this mechanism can be formulated as a convex program of polynomial size. More importantly, the formulation yields a set of n x n unique marginal prices that are sufficient to price the bets in this mechanism, and are computable in polynomial-time. The marginal prices reflect the traders' beliefs about the marginal distributions over outcomes. We also propose techniques to compute the joint distribution over n! permutations from these marginal distributions. We show that using a maximum entropy criterion, we can obtain a concise parametric form (with only n x n parameters) for the joint dist...

  1. Tokamak dust particle size and surface area measurement

    Energy Technology Data Exchange (ETDEWEB)

    Carmack, W.J.; Smolik, G.R.; Anderl, R.A.; Pawelko, R.J.; Hembree, P.B.

    1998-07-01

    The INEEL has analyzed a variety of dust samples from experimental tokamaks: General Atomics` DII-D, Massachusetts Institute of Technology`s Alcator CMOD, and Princeton`s TFTR. These dust samples were collected and analyzed because of the importance of dust to safety. The dust may contain tritium, be activated, be chemically toxic, and chemically reactive. The INEEL has carried out numerous characterization procedures on the samples yielding information useful both to tokamak designers and to safety researchers. Two different methods were used for particle characterization: optical microscopy (count based) and laser based volumetric diffraction (mass based). Surface area of the dust samples was measured using Brunauer, Emmett, and Teller, BET, a gas adsorption technique. The purpose of this paper is to present the correlation between the particle size measurements and the surface area measurements for tokamak dust.

  2. Pore-Scale Heterogeneity in the Mineral Distribution and Reactive Surface Area of Porous Rocks

    Science.gov (United States)

    Lai, P. E. P.; Krevor, S. C.

    2015-12-01

    The reactive surface area is an important control on interfacial processes between minerals and aqueous fluids in porous rocks. Spatial heterogeneity in the surface area can lead to complications in modelling reactive transport processes, but quantitative characterisation of this property has been limited. In this paper 3D images obtained using x-ray micro-tomography were used to characterise heterogeneity in surface area in one sandstone and five carbonate rocks. Measurements of average surface area from x-ray imagery were 1-2 orders of magnitude lower than measurements from nitrogen BET. A roughness factor, defined as the ratio of BET surface area to x-ray based surface area, was correlated to the presence of clay or microporosity. Coregistered images of Berea sandstone from x-ray and energy dispersive spectroscopy imagery were used to guide the identification of quartz, K-feldspar, dolomite, calcite and clays in x-ray images. In Berea sandstone, clay and K-feldspar had higher average surface area fractions than their volumetric fractions in the rock. In the Edwards carbonate, however, modal mineral composition correlated with surface area. By sub-sampling digital images, statistical distributions of the surface area were generated at various length scales of subsampling. Comparing these to distributions used in published modelling studies showed that the common practice of leaving surface area and pore volume uncorrelated in a pore leads to unrealistic combinations of surface area and pore volume in the models. We suggest these models adopt a moderate correlation based on observations. In Berea sandstone, constraining ratios of surface area to pore volume to a range of values between that of quartz-lined and five times that of clay-lined spheres appeared sufficient.

  3. Surface area of lactose and lactose granulates on consolidation and compaction

    OpenAIRE

    Riepma, Klaas Alouis

    1993-01-01

    This dissertation discusses the effect of short time storage at different conditions on the strength and the specific BET surface area of lactose tablets. In addition, some aspects are studied of the consolidation and compaction properties of crystalline lactose fractions in heterogeneous systems. The crystalline lactose types used are: a-lactose monohydrate, anhydrous a-lactose, crystalline B-lactose and roller dried B-lactose. ... Zie: Summary

  4. Betting against health care.

    Science.gov (United States)

    Appleby, C

    1996-06-20

    Health care firms of all types helped fuel the biggest short-selling frenzy in the New York Stock Exchange's history, recently hitting a record 2.2 billion shares. While some analysts say this means nothing, the fact is that many investors are "shorting" the stock; in other words, they're betting against it. What appears as a lack of confidence may be nothing more than a simple quirk of Wall Street. Good, bad or indifferent, selling short is no tall tale.

  5. Synthesis and characterization of high-surface-area millimeter-sized silica beads with hierarchical multi-modal pore structure by the addition of agar

    Energy Technology Data Exchange (ETDEWEB)

    Han, Yosep; Choi, Junhyun [Department of Mineral Resources and Energy Engineering, Chonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju-si, Jeollabuk-do 561–756 (Korea, Republic of); Tong, Meiping, E-mail: tongmeiping@iee.pku.edu.cn [The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871 (China); Kim, Hyunjung, E-mail: kshjkim@jbnu.ac.kr [Department of Mineral Resources and Energy Engineering, Chonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju-si, Jeollabuk-do 561–756 (Korea, Republic of)

    2014-04-01

    Millimeter-sized spherical silica foams (SSFs) with hierarchical multi-modal pore structure featuring high specific surface area and ordered mesoporous frameworks were successfully prepared using aqueous agar addition, foaming and drop-in-oil processes. The pore-related properties of the prepared spherical silica (SSs) and SSFs were systematically characterized by field emission-scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), small-angle X-ray diffraction (SAXRD), Hg intrusion porosimetry, and N{sub 2} adsorption–desorption isotherm measurements. Improvements in the BET surface area and total pore volume were observed at 504 m{sup 2} g{sup −1} and 5.45 cm{sup 3} g{sup −1}, respectively, after an agar addition and foaming process. Despite the increase in the BET surface area, the mesopore wall thickness and the pore size of the mesopores generated from the block copolymer with agar addition were unchanged based on the SAXRD, TEM, and BJH methods. The SSFs prepared in the present study were confirmed to have improved BET surface area and micropore volume through the agar loading, and to exhibit interconnected 3-dimensional network macropore structure leading to the enhancement of total porosity and BET surface area via the foaming process. - Highlights: • Millimeter-sized spherical silica foams (SSFs) are successfully prepared. • SSFs exhibit high BET surface area and ordered hierarchical pore structure. • Agar addition improves BET surface area and micropore volume of SSFs. • Foaming process generates interconnected 3-D network macropore structure of SSFs.

  6. Preparation and Characterization of Porous Yttrium Oxide Powders with High Specific Surface Area

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The porous cubic yttrium oxides with high specific surface area were prepared by the explosive decomposition of yttrium nitrate and its complex formed with methyl salicylate. The specific surface area and properties of powders synthesized at various temperatures were characterized using BET, X-ray diffraction (XRD), infrared spectra (IR), and scanning electron microscopy (SEM). The results indicate that the highest specific surface area is found to be 65.37 m2*g-1 at the calcination temperature of 600 ℃, and then decreases to 20.33 m2*g-1 with the calcination temperature rising from 600 to 900 ℃. The powders show strong surface activity for adsorping water and carbon dioxide in air, which also decreases with the rising calcination temperature. The drop both on the surface area and surface activity of samples at higher temperatures may be due to pore-narrowing(sintering) effects.

  7. Betting against Beta

    DEFF Research Database (Denmark)

    Frazzini, Andrea; Heje Pedersen, Lasse

    2014-01-01

    We present a model with leverage and margin constraints that vary across investors and time. We find evidence consistent with each of the model's five central predictions: (1) Because constrained investors bid up high-beta assets, high beta is associated with low alpha, as we find empirically for......, the return of the BAB factor is low. (4) Increased funding liquidity risk compresses betas toward one. (5) More constrained investors hold riskier assets....... for US equities, 20 international equity markets, Treasury bonds, corporate bonds, and futures. (2) A betting against beta (BAB) factor, which is long leveraged low-beta assets and short high-beta assets, produces significant positive risk-adjusted returns. (3) When funding constraints tighten...

  8. Betting Against Beta

    DEFF Research Database (Denmark)

    Frazzini, Andrea; Heje Pedersen, Lasse

    We present a model with leverage and margin constraints that vary across investors and time. We find evidence consistent with each of the model’s five central predictions: (1) Since constrained investors bid up high-beta assets, high beta is associated with low alpha, as we find empirically for U...... of the BAB factor is low; (4) Increased funding liquidity risk compresses betas toward one; (5) More constrained investors hold riskier assets........S. equities, 20 international equity markets, Treasury bonds, corporate bonds, and futures; (2) A betting-against-beta (BAB) factor, which is long leveraged low beta assets and short high-beta assets, produces significant positive risk-adjusted returns; (3) When funding constraints tighten, the return...

  9. Dye-Sensitized Solar Cells Based on High Surface Area Nanocrystalline Zinc Oxide Spheres

    Directory of Open Access Journals (Sweden)

    Pavuluri Srinivasu

    2011-01-01

    Full Text Available High surface area nanocrystalline zinc oxide material is fabricated using mesoporous nanostructured carbon as a sacrificial template through combustion process. The resulting material is characterized by XRD, N2 adsorption, HR-SEM, and HR-TEM. The nitrogen adsorption measurement indicates that the materials possess BET specific surface area ca. 30 m2/g. Electron microscopy images prove that the zinc oxide spheres possess particle size in the range of 0.12 μm–0.17 μm. The nanocrystalline zinc oxide spheres show 1.0% of energy conversion efficiency for dye-sensitized solar cells.

  10. Inverse gas chromatography for natural fibre characterisation: Identification of the critical parameters to determine the Brunauer-Emmett-Teller specific surface area.

    Science.gov (United States)

    Legras, A; Kondor, A; Heitzmann, M T; Truss, R W

    2015-12-18

    Inverse gas chromatography (IGC) is an alternative technique to determine the specific surface area of natural fibres. Natural fibres have a complex surface chemistry and unique microstructure that challenge the current capabilities to perform surface characterisation. This study investigated the influence of multiple parameters on the measured Brunauer-Emmett-Teller (BET) specific surface area for samples of flax, kenaf and BioMid(®) cellulose fibres using IGC. The BET surface area of kenaf and flax differed with 0.51m(2)g(-1) and 1.35m(2)g(-1) respectively, the former being similar to the cellulose fibres (0.54m(2)g(-1)). The data was calculated under conditions where the BET equation showed good linearity (R(2)⩾0.995). Repeatability was excellent so that two runs sufficed to obtain representative BET surface area values. The findings showed the choice of solvent was important for all specimens to avoid any misleading data comparison due to molecular orientation effects that impact the adsorbent-adsorbate interactions. The higher surface area of the flax sample, and its higher variability, was correlated with a higher surface roughness observed under optical microscopy. Packing the chromatography column with long or chopped fibres produced results that were statistically insignificant.

  11. Pore Scale Heterogeneity in the Mineral Distribution and Surface Area of Porous Rocks

    Science.gov (United States)

    Lai, Peter; Krevor, Sam

    2015-04-01

    An important control on rate of interfacial processes between minerals and aqueous solutions such as nucleation of solids, and mineral dissolution and growth is reactive surface area. In geochemical modelling, the continuum hypothesis is based on the assumption that the system can be represented by a sufficiently large number of representative elemental volumes. There has been recent interest in studying the impact of this assumption on reaction-transport coupled systems. In this study, the impact of pore-scale heterogeneity on the distribution of reactive surface area is discussed. 3D images obtained using x-ray micro-tomography were used to characterise the distribution of reactive surface area. The results were compared to independent observations. Mineral identification using x- ray diffraction and fluorescence suggested general agreement with CT analysis. Nitrogen BET surface areas were one to two orders of magnitude higher than measurements from x-ray imagery. Co- registered images of Berea sandstone from x-ray and energy dispersive spectroscopy imagery suggested that quartz, K-feldspar and most clays could be identified. However, minor minerals such as albite and illite did not exhibit enough contrast. In Berea sandstone, mineral surface area fraction was poorly correlated to the mineral volumetric fraction. Clay and feldspar minerals exhibited higher surface area fractions than bulk mineralogy suggested. In contrast, in the Edwards carbonate samples, modal mineral composition correlated with mineral-specific surface area. Berea sandstone revealed a characteristic pore size at which a surface area distribution may be used to quantify heterogeneity. Conversely, the carbonate samples suggested a continuous range of pore sizes across length scales. A comparison with pore network model simulations from the literature was made. First order estimates of mineral specific correlations between geometric area measured in the x-ray images were used to convert the CT

  12. T-bet as a key regulator of mucosal immunity.

    Science.gov (United States)

    Mohamed, Rami; Lord, Graham M

    2016-04-01

    Initially understood to be a key regulator of interferon-γ-producing helper T cells, our knowledge of T-bet's functional roles has expanded to encompass a growing range of cellular lineages. In addition to regulating other interferon-γ-producing adaptive immune cells, it is now clear that T-bet plays a fundamental role in the regulation of innate immune responses across mucosal surfaces. This homeostatic role is demonstrated by the spontaneous colitis that occurs when T-bet is deleted from innate immune cells in RAG(-/-) mice. Using this model as a focal point, we review our understanding of T-bet's regulation of adaptive and innate immune systems, focusing particularly on mucosal populations including innate lymphoid cells, dendritic cells and intraepithelial lymphocytes. With the increasingly diverse effects of T-bet on different lineages, the classical binding-centric paradigm of T-bet's molecular functionality has increasingly struggled to account for the versatility of T-bet's biological effects. Recent recognition of the synergistic interactions between T-bet and other canonical transcription factors has led to a co-operative paradigm that has provided greater explanatory power. Synthesizing insights from ChIP-seq and comparative biology, we expand the co-operative paradigm further and suggest a network approach as a powerful way to understand and model T-bet's diverse functionality.

  13. Improved analytic methods for coal surface area and pore size distribution determination using 77 K nitrogen adsorption experiment

    Institute of Scientific and Technical Information of China (English)

    Wang Gongda; Wang Kai; Ren Tingxiang

    2014-01-01

    77 K nitrogen adsorption was the most widely used technique for determining surface area and pore size distribution of coal. Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) model are com-monly used analytic methods for adsorption/desorption isotherm. A Chinese anthracite coal is tested in this study using an improved experimental method and adsorption isotherm analyzed by three adsorp-tion mechanisms at different relative pressure stages. The result shows that the micropore filling adsorp-tion predominates at the relative pressure stage from 6.8E?7 to 9E?3. Theoretically, BET and BJH model are not appropriate for analyzing coal samples which contain micropores. Two new analytic procedures for coal surface area and pore size distribution calculation are developed in this work. The results show that BET model underestimates surface area, and micropores smaller than 1.751 nm account for 35.5%of the total pore volume and 74.2%of the total surface area. The investigation of surface area and pore size distribution by incorporating the influence of micropore is significant for understanding adsorption mechanism of methane and carbon dioxide in coal.

  14. Modified-EISA synthesis of mesoporous high surface area CeO_2 and catalytic property for CO oxidation

    Institute of Scientific and Technical Information of China (English)

    李霞章; 陈丰; 陆晓旺; 倪超英; 陈志刚

    2009-01-01

    Mesoporous CeO2 particles with high surface area were synthesized using a modified evaporation-induced self assembly(EISA) method which combined citric acid as complexing agent.As-prepared powder and further thermal treatment samples were characterized by X-ray diffraction(XRD),transmission electron microscopy(TEM),selected area electron diffraction(SAED),Fourier transform infrared spectrometer(FTIR),thermogravimetry and differential thermal analysis(TG-DTA),Brunauer-Emmett-Teller(BET) and Barrett-Joyner-Ha...

  15. Uptake of acetone, ethanol and benzene to snow and ice: effects of surface area and temperature

    Science.gov (United States)

    Abbatt, J. P. D.; Bartels-Rausch, T.; Ullerstam, M.; Ye, T. J.

    2008-10-01

    The interactions of gas-phase acetone, ethanol and benzene with smooth ice films and artificial snow have been studied. In one technique, the snow is packed into a cylindrical column and inserted into a low-pressure flow reactor coupled to a chemical-ionization mass spectrometer for gas-phase analysis. At 214 and 228 K, it is found for acetone and ethanol that the adsorbed amounts per surface area match those for adsorption to thin films of ice formed by freezing liquid water, when the specific surface area of the snow (as determined from Kr adsorption at 77 K) and the geometric surface area of the ice films are used. This indicates that freezing thin films of water leads to surfaces that are smooth at the molecular level. Experiments performed to test the effect of film growth on ethanol uptake indicate that uptake is independent of ice growth rate, up to 2.4 µm min-1. In addition, traditional Brunauer-Emmett-Teller (BET) experiments were performed with these gases on artificial snow from 238 to 266.5 K. A transition from a BET type I isotherm indicative of monolayer formation to a BET type II isotherm indicative of multilayer uptake is observed for acetone at T>=263 K and ethanol at T>=255 K, arising from solution formation on the ice. When multilayer formation does not occur, as was the case for benzene at T<=263 K and for acetone at T<=255 K, the saturated surface coverage increased with increasing temperature, consistent with the quasi-liquid layer affecting adsorption prior to full dissolution/multilayer formation.

  16. Uptake of acetone, ethanol and benzene to snow and ice: effects of surface area and temperature

    Energy Technology Data Exchange (ETDEWEB)

    Abbatt, J P D; Bartels-Rausch, T; Ullerstam, M; Ye, T J [Department of Chemistry, University of Toronto, 80 St George Street, Toronto, ON M5S 3H6 (Canada)

    2008-10-15

    The interactions of gas-phase acetone, ethanol and benzene with smooth ice films and artificial snow have been studied. In one technique, the snow is packed into a cylindrical column and inserted into a low-pressure flow reactor coupled to a chemical-ionization mass spectrometer for gas-phase analysis. At 214 and 228 K, it is found for acetone and ethanol that the adsorbed amounts per surface area match those for adsorption to thin films of ice formed by freezing liquid water, when the specific surface area of the snow (as determined from Kr adsorption at 77 K) and the geometric surface area of the ice films are used. This indicates that freezing thin films of water leads to surfaces that are smooth at the molecular level. Experiments performed to test the effect of film growth on ethanol uptake indicate that uptake is independent of ice growth rate, up to 2.4 {mu}m min{sup -1}. In addition, traditional Brunauer-Emmett-Teller (BET) experiments were performed with these gases on artificial snow from 238 to 266.5 K. A transition from a BET type I isotherm indicative of monolayer formation to a BET type II isotherm indicative of multilayer uptake is observed for acetone at T{>=}263 K and ethanol at T{>=}255 K, arising from solution formation on the ice. When multilayer formation does not occur, as was the case for benzene at T{<=}263 K and for acetone at T{<=}255 K, the saturated surface coverage increased with increasing temperature, consistent with the quasi-liquid layer affecting adsorption prior to full dissolution/multilayer formation.

  17. Experimental evolution of bet hedging.

    Science.gov (United States)

    Beaumont, Hubertus J E; Gallie, Jenna; Kost, Christian; Ferguson, Gayle C; Rainey, Paul B

    2009-11-05

    Bet hedging-stochastic switching between phenotypic states-is a canonical example of an evolutionary adaptation that facilitates persistence in the face of fluctuating environmental conditions. Although bet hedging is found in organisms ranging from bacteria to humans, direct evidence for an adaptive origin of this behaviour is lacking. Here we report the de novo evolution of bet hedging in experimental bacterial populations. Bacteria were subjected to an environment that continually favoured new phenotypic states. Initially, our regime drove the successive evolution of novel phenotypes by mutation and selection; however, in two (of 12) replicates this trend was broken by the evolution of bet-hedging genotypes that persisted because of rapid stochastic phenotype switching. Genome re-sequencing of one of these switching types revealed nine mutations that distinguished it from the ancestor. The final mutation was both necessary and sufficient for rapid phenotype switching; nonetheless, the evolution of bet hedging was contingent upon earlier mutations that altered the relative fitness effect of the final mutation. These findings capture the adaptive evolution of bet hedging in the simplest of organisms, and suggest that risk-spreading strategies may have been among the earliest evolutionary solutions to life in fluctuating environments.

  18. Body Surface Area Prediction in Odorrana grahami

    Institute of Scientific and Technical Information of China (English)

    Guiying CHEN; Jiongyu LIU; Qiang DAI; Jianping JIANG

    2014-01-01

    Body surface area (BSA) was regarded as a more readily quantiifable parameter relative to body mass in the normalization of comparative biochemistry and physiology. The BSA prediction has attracted unceasing research back more than a century on animals, especially on humans and rats. Few studies in this area for anurans were reported, and the equation for body surface area (S) and body mass (W):S=9.9 W 0.56, which was concluded from toads of four species in 1969, was generally adopted to estimate the body surface areas for anurans until recent years. However, this equation was not applicable to Odorrana grahami. The relationship between body surface area and body mass for this species was established as:S=15.4 W 0.579. Our current results suggest estimation equations should be used cautiously across different species and body surface area predictions on more species need to be conducted.

  19. Estimation of surface area and surface area measure of three-dimensional sets from digitizations

    DEFF Research Database (Denmark)

    Ziegel, Johanna; Kiderlen, Markus

    2010-01-01

    A local method for estimating surface area and surface area measure of three-dimensional objects from discrete binary images is presented. A weight is assigned to each 2 × 2 × 2 configuration of voxels and the total surface area of an object is given by summation of the local area contributions. ...

  20. Palatal Surface Area of Maxillary Plaster Casts

    DEFF Research Database (Denmark)

    Darvann, Tron Andre; Hermann, Nuno V.; Ersbøll, Bjarne Kjær;

    2007-01-01

    -dimensional measurements of selected linear distances, curve lengths, and (surface) areas were carried out on maxillary plaster casts from individuals with unilateral or bilateral cleft lip and palate. The relationship between two-dimensional and three-dimensional measurements was investigated using linear regression....... Results and Conclusions: Error sources in the measurement of three-dimensional palatal segment surface area from a two-dimensional photograph were identified as photographic distortion (2.7%), interobserver error (3.3%), variability in the orientation of the plaster cast (3.2%), and natural shape...... variation (4.6%). The total error of determining the cleft area/palate surface area ratio was 15%. In population studies, the effect of using two-dimensional measurements is a decrease of discriminating power. In well-calibrated setups, a two-dimensional measurement of the cleft area/palate surface area...

  1. Preparation of High Surface Area, Large Pore Volume Alumina by Using β-Cyclodextrin as a Non-surfactant Template

    Institute of Scientific and Technical Information of China (English)

    Lai Jun WANG; Ming Fen WEN; Yu Shan LI; Dong YANG; Jing CHEN; Chong Li SONG

    2006-01-01

    A series of alumina samples were prepared using β-cyclodextrin as the non-surfactant template. These samples were characterized by XRD, BET and TEM. The results showed that the alumina samples prepared using β-cyclodextrin template had the higher surface areas (124-484 m2/g), larger pore volumes (0.7-1.27 mL/g) and more thermal stability than samples prepared without using β-cyclodextrin.

  2. Facile synthesis of high surface area molybdenum nitride and carbide

    Science.gov (United States)

    Roy, Aaron; Serov, Alexey; Artyushkova, Kateryna; Brosha, Eric L.; Atanassov, Plamen; Ward, Tim L.

    2015-08-01

    The synthesis of high surface area γ-Mo2N and α-Mo2C is reported (116 and 120 m2/g) without the temperature programmed reduction of MoO3. γ-Mo2N was prepared in an NH3-free synthesis using forming gas (7 at% H2, N2-balance) as the reactive atmosphere. Three precursors were studied ((NH4)6Mo7O24·4H2O, (NH4)2 Mg(MoO4)2, and MgMoO4) along with the sacrificial support method (SSM) as a means of reducing the particle size of Mo2N and Mo2C. In situ X-ray diffraction (XRD) studies were carried out to identify reaction intermediates, the temperature at which various intermediates form, and the average domain size of the Mo2N products. Materials were synthesized in bulk and further characterized by XRD, HRTEM, XPS, and BET.

  3. Nondestructive, stereological estimation of canopy surface area

    DEFF Research Database (Denmark)

    Wulfsohn, Dvora-Laio; Sciortino, Marco; Aaslyng, Jesper M.;

    2010-01-01

    We describe a stereological procedure to estimate the total leaf surface area of a plant canopy in vivo, and address the problem of how to predict the variance of the corresponding estimator. The procedure involves three nested systematic uniform random sampling stages: (i) selection of plants from...... is high. Using a grid intensity of 1.76 cm2/point we estimated plant and canopy surface areas with accuracies similar to or better than those obtained using image analysis and a commercial leaf area meter. For canopy surface areas of approximately 1 m2 (10 plants), the fractionator leaf approach...... a canopy using the smooth fractionator, (ii) sampling of leaves from the selected plants using the fractionator, and (iii) area estimation of the sampled leaves using point counting. We apply this procedure to estimate the total area of a chrysanthemum (Chrysanthemum morifolium L.) canopy and evaluate both...

  4. National Sports Betting in Europe

    DEFF Research Database (Denmark)

    Budzinski, Oliver; Feddersen, Arne; Satzer, Janina;

    Liga" . National legislation of EU member states can still restrict the freedom to provide gambling services by a monopoly system but only under rather restrictive conditions (necessity, proportionality, non-discrimination). Consequently, a new Danish Gaming Act was proposed. It includes, among other...... political aims, and (ii) offer a comparison to a regulated, competitive betting market. Differing from the (few) existing literature, our analysis systematically accounts for the effects from the loss of sports betting revenues as a means to finance elite, amateur and youth sports. Eventually, policy...

  5. Archaeology of Bet Dwarka Island

    Digital Repository Service at National Institute of Oceanography (India)

    Sundaresh; Gaur, A.S.

    the protohistoric and historic period were found. The former include a seal, inscriptions and pottery, while the latter consist of coins and pottery. The earliest settlement at Bet Dwarka may be dated to the late phase of the Indus Civilization, i.e. c. 1400 B...

  6. Mesoporous high surface area Ce0.9Gd0.1O1.95 synthesized by spray drying

    DEFF Research Database (Denmark)

    Lundberg, Mats; Wang, Hsiang-Jen; Blennow Tullmar, Peter;

    2011-01-01

    Mesoporous gadolinium doped cerium dioxide with high surface area was produced by spray drying using Pluronic 123 as surfactant. The powder, when calcined at 400 °C, had a BET surface area of 136 m2 g−1 and was polycrystalline as confirmed by XRD and TEM. XEDS confirmed Ce, Gd and O, as the only......, corresponding to the crystallite size calculated from XRD data. The similar size range of the mesopores and the observed crystallite size indicates that the porosity is partly formed from intergranular mesoporosity. Using the spray drying method of a surfactant assisted liquid precursor solution it can...

  7. Surface moisture estimation in urban areas

    Science.gov (United States)

    Jiang, Yitong

    Surface moisture is an important parameter because it modifies urban microclimate and surface layer meteorology. The primary objectives of this paper are: 1) to analyze the impact of surface roughness from buildings on surface moisture in urban areas; and 2) to quantify the impact of surface roughness resulting from urban trees on surface moisture. To achieve the objectives, two hypotheses were tested: 1) the distribution of surface moisture is associated with the structural complexity of buildings in urban areas; and 2) The distribution and change of surface moisture is associated with the distribution and vigor of urban trees. The study area is Indianapolis, Indiana, USA. In the part of the morphology of urban trees, Warren Township was selected due to the limitation of tree inventory data. To test the hypotheses, the research design was made to extract the aerodynamic parameters, such as frontal areas, roughness length and displacement height of buildings and trees from Terrestrial and Airborne LiDAR data, then to input the aerodynamic parameters into the urban surface energy balance model. The methodology was developed for comparing the impact of aerodynamic parameters from LiDAR data with the parameters that were derived empirically from land use and land cover data. The analytical procedures are discussed below: 1) to capture the spatial and temporal variation of surface moisture, daily and hourly Land Surface Temperature (LST) were downscaled from 4 km to 1 km, and 960 m to 30 m, respectively, by regression between LST and various components that impact LST; 2) to estimate surface moisture, namely soil moisture and evapotranspiration (ET), land surfaces were classified into soil, vegetation, and impervious surfaces, using Linear Spectral Mixture Analysis (LSMA); 3) aerodynamic parameters of buildings and trees were extracted from Airborne and Terrestrial LiDAR data; 4) the Temperature-Vegetation-Index (TVX) method, and the Two-Source-Energy-Balance (TSEB

  8. Electrospun anatase-phase TiO2 nanofibers with different morphological structures and specific surface areas.

    Science.gov (United States)

    He, Guangfei; Cai, Yibing; Zhao, Yong; Wang, Xiaoxu; Lai, Chuilin; Xi, Min; Zhu, Zhengtao; Fong, Hao

    2013-05-15

    Electrospun anatase-phase TiO2 nanofibers with desired morphological structure and relatively high specific surface area are expected to outperform other nanostructures (e.g., powder and film) of TiO2 for various applications (particularly dye-sensitized solar cell and photo-catalysis). In this study, systematic investigations were carried out to prepare and characterize electrospun anatase-phase TiO2 nanofibers with different morphological structures (e.g., solid, hollow/tubular, and porous) and specific surface areas. The TiO2 nanofibers were generally prepared via electrospinning of precursor nanofibers followed by pyrolysis at 500°C. For making hollow/tubular TiO2 nanofibers, the technique of co-axial electrospinning was utilized; while for making porous TiO2 nanofibers, the etching treatment in NaOH aqueous solution was adopted. The results indicated that the hollow/tubular TiO2 nanofibers (with diameters of ~300-500 nm and wall-thickness in the range from tens of nanometers to ~200 nm) had the BET specific surface area of ~27.3 m(2)/g, which was approximately twice as that of the solid TiO2 nanofibers (~15.2 m(2)/g) with diameters of ~200-300 nm and lengths of at least tens of microns. Porous TiO2 nanofibers made from the precursor of Al2O3/TiO2 composite nanofibers had the BET specific surface area of ~106.5 m(2)/g, whereas porous TiO2 nanofibers made from the precursor of ZnO/TiO2 composite nanofibers had the highest BET specific surface area of ~148.6 m(2)/g.

  9. Evaluation of mineral reactive surface area estimates for prediction of reactivity of a multi-mineral sediment

    Science.gov (United States)

    Beckingham, Lauren E.; Mitnick, Elizabeth H.; Steefel, Carl I.; Zhang, Shuo; Voltolini, Marco; Swift, Alexander M.; Yang, Li; Cole, David R.; Sheets, Julia M.; Ajo-Franklin, Jonathan B.; DePaolo, Donald J.; Mito, Saeko; Xue, Ziqiu

    2016-09-01

    Our limited understanding of mineral reactive surface area contributes to significant uncertainties in quantitative simulations of reactive chemical transport in subsurface processes. Continuum formulations for reactive transport typically use a number of different approximations for reactive surface area, including geometric, specific, and effective surface area. In this study, reactive surface area estimates are developed and evaluated for their ability to predict dissolution rates in a well-stirred flow-through reactor experiment using disaggregated samples from the Nagaoka pilot CO2 injection site (Japan). The disaggregated samples are reacted with CO2 acidified synthetic brine under conditions approximating the field conditions and the evolution of solute concentrations in the reactor effluent is tracked over time. The experiments, carried out in fluid-dominated conditions at a pH of 3.2 for 650 h, resulted in substantial dissolution of the sample and release of a disproportionately large fraction of the divalent cations. Traditional reactive surface area estimation methods, including an adjusted geometric surface area and a BET-based surface area, are compared to a newly developed image-based method. Continuum reactive transport modeling is used to determine which of the reactive surface area models provides the best match with the effluent chemistry from the well-stirred reactor. The modeling incorporates laboratory derived mineral dissolution rates reported in the literature and the initial modal mineralogy of the Nagaoka sediment was determined from scanning electron microscopy (SEM) characterization. The closest match with the observed steady-state effluent concentrations was obtained using specific surface area estimates from the image-based approach supplemented by literature-derived BET measurements. To capture the evolving effluent chemistry, particularly over the first 300 h of the experiment, it was also necessary to account for the grain size

  10. Targeting BET bromodomain proteins in solid tumors.

    Science.gov (United States)

    Sahai, Vaibhav; Redig, Amanda J; Collier, Katharine A; Eckerdt, Frank D; Munshi, Hidayatullah G

    2016-08-16

    There is increasing interest in inhibitors targeting BET (bromodomain and extra-terminal) proteins because of the association between this family of proteins and cancer progression. BET inhibitors were initially shown to have efficacy in hematologic malignancies; however, a number of studies have now shown that BET inhibitors can also block progression of non-hematologic malignancies. In this Review, we summarize the efficacy of BET inhibitors in select solid tumors; evaluate the role of BET proteins in mediating resistance to current targeted therapies; and consider potential toxicities of BET inhibitors. We also evaluate recently characterized mechanisms of resistance to BET inhibitors; summarize ongoing clinical trials with these inhibitors; and discuss potential future roles of BET inhibitors in patients with solid tumors.

  11. Area inequalities for stable marginally trapped surfaces

    CERN Document Server

    Jaramillo, José Luis

    2012-01-01

    We discuss a family of inequalities involving the area, angular momentum and charges of stably outermost marginally trapped surfaces in generic non-vacuum dynamical spacetimes, with non-negative cosmological constant and matter sources satisfying the dominant energy condition. These inequalities provide lower bounds for the area of spatial sections of dynamical trapping horizons, namely hypersurfaces offering quasi-local models of black hole horizons. In particular, these inequalities represent particular examples of the extension to a Lorentzian setting of tools employed in the discussion of minimal surfaces in Riemannian contexts.

  12. Monitoring System for ALICE Surface Areas

    CERN Document Server

    Demirbasci, Oguz

    2016-01-01

    I have been at CERN for 12 weeks within the scope of Summer Student Programme working on a monitoring system project for surface areas of the ALICE experiment during this period of time. The development and implementation of a monitoring system for environmental parameters in the accessible areas where a cheap hardware setup can be deployed were aim of this project. This report explains how it was developed by using Arduino, Raspberry PI, WinCC OA and DIM protocol.

  13. Osmosis and Surface Area to Volume Ratio.

    Science.gov (United States)

    Barrett, D. R. B.

    1984-01-01

    Describes an experiment designed to help students understand the concepts of osmosis and surface area to volume ratio (SA:VOL). The task for students is to compare water uptake in different sizes of potato cubes and relate differences to their SA:VOL ratios. (JN)

  14. Volumes and surface areas of pendular rings

    Science.gov (United States)

    Rose, W.

    1958-01-01

    A packing of spheres is taken as a suitable model of porous media. The packing may be regular and the sphere size may be uniform, but in general, both should be random. Approximations are developed to give the volumes and surface areas of pendular rings that exist at points of sphere contact. From these, the total free volume and interfacial specific surface area are derived as expressive of the textural character of the packing. It was found that the log-log plot of volumes and surface areas of pendular rings vary linearly with the angle made by the line joining the sphere centers and the line from the center of the largest sphere to the closest edge of the pendular ring. The relationship, moreover, was found not to be very sensitive to variation in the size ratio of the spheres in contact. It also was found that the addition of pendular ring material to various sphere packings results in an unexpected decrease in the surface area of the boundaries that confine the resulting pore space. ?? 1958 The American Institute of Physics.

  15. Preparation, Surface and Pore Structure of High Surface Area Activated Carbon Fibers from Bamboo by Steam Activation

    Directory of Open Access Journals (Sweden)

    Xiaojun Ma

    2014-06-01

    Full Text Available High surface area activated carbon fibers (ACF have been prepared from bamboo by steam activation after liquefaction and curing. The influences of activation temperature on the microstructure, surface area and porosity were investigated. The results showed that ACF from bamboo at 850 °C have the maximum iodine and methylene blue adsorption values. Aside from the graphitic carbon, phenolic and carbonyl groups were the predominant functions on the surface of activated carbon fiber from bamboo. The prepared ACF from bamboo were found to be mainly type I of isotherm, but the mesoporosity presented an increasing trend after 700 °C. The surface area and micropore volume of samples, which were determined by application of the Brunauer-Emmett-Teller (BET and t-plot methods, were as high as 2024 m2/g and 0.569 cm3/g, respectively. It was also found that the higher activation temperature produced the more ordered microcrystalline structure of ACF from bamboo.

  16. Bet-hedging applications for conservation

    Indian Academy of Sciences (India)

    Mark S Boyce; Eileen M Kirsch; Christopher Servheen

    2002-07-01

    One of the early tenets of conservation biology is that population viability is enhanced by maintaining multiple populations of a species. The strength of this tenet is justified by principles of bet-hedging. Management strategies that reduce variance in population size will also reduce risk of extinction. Asynchrony in population fluctuations in independent populations reduces variance in the aggregate of populations whereas environmental correlation among areas increases the risk that all populations will go extinct. We review the theoretical rationale of bet-hedging and suggest applications for conservation management of least terns in Nebraska and grizzly bears in the northern Rocky Mountains of the United States. The risk of extinction for least terns will be reduced if we can sustain the small central Platte River population in addition to the larger population on the lower Platte. Similarly, by restoring grizzly bears to the Bitterroot wilderness of Idaho and Montana can reduce the probability of extinction for grizzly bears in the Rocky Mountains of the United States by as much as 69–93%.

  17. High surface area fibrous silica nanoparticles

    KAUST Repository

    Polshettiwar, Vivek

    2014-11-11

    Disclosed are high surface area nanoparticles that have a fibrous morphology. The nanoparticles have a plurality of fibers, wherein each fiber is in contact with one other fiber and each fiber has a length of between about 1 nm and about 5000 nm. Also disclosed are applications of the nanoparticles of the present invention, and methods of fabrication of the nanoparticles of the present invention.

  18. Synthesis of High Surface Area and Well Crystallized Mesoporous WC at Low Temperature with a Pore Structure Collapsed Replication Route

    Institute of Scientific and Technical Information of China (English)

    LI Hua; SHI Jianlin; CHEN Hangrong; ZHANG Lingxia; LI Lei

    2011-01-01

    An approach named "pore structure collapsed replication route" has been developed to prepare mesoporous WC materials with a high surface area (105 m2/g) and crystallized framework at a temperature as low as 700 ℃. The XRD, TEM, EDS, and BET characterizations were conducted to analyze the effects of the synthesis parameters and the template types on the structure of mesoporous WC. The compaction on the templates is the key to form mesoporous structure of WC while the templates help to control the size of crystalline. At a content of 7 wt% for the precursor of WC, the mesoporous WC could be formed with well ordered structure.

  19. Biggest bets in the universe unveiled

    CERN Multimedia

    Jamieson, Valerie

    2004-01-01

    Betting on the greatest unsolved problems in the universe is no longer the preserve of academic superstars such as Stephen Hawking. From Thursday, anyone will be able to place bets on whether the biggest physics experiments in the world will come good before 2010

  20. Bookmaker and pari-mutuel betting

    DEFF Research Database (Denmark)

    Koch, Alexander; Shing, Hui-Fai

    2008-01-01

    A widely documented empirical regularity in gambling markets is that bets on high probability events (a race won by a "favourite") have higher expected returns than bets on low probability events (a "longshot" wins). Such favourite-longshot (FL) biases however appear to be more severe and persist...

  1. Effect of Preparation Method on Surface Area and Crystalline Form of CeO2-ZrO2 Solid Solution

    Institute of Scientific and Technical Information of China (English)

    王晓红; 郭耘; 卢冠忠; 郭杨龙; 王筠松; 张志刚; 刘晓晖

    2004-01-01

    The CeO2-ZrO2 solid solutions were prepared by a reverse microemulsion method. The effect of preparation parameters on the surface area and crystalline form of the solid solutions were studied by the BET surface area and XRD analysis. The studies indicate that the separation of the microemulsion phase during the preparation procedure can decrease the specific surface area of sample, adding hydrogen peroxide in the matrix solution can increase the specific surface area and stability of sample. The surface area of sample calcined at 550 ℃ for 5 h is 149 m2·g-1, and that calcined at 900 ℃ for 6 h is 88 m2·g-1.The sample with tetragonal symmetry Ce0.5Zr0.5O2 phase has a higher stability.

  2. Accessible surface area from NMR chemical shifts

    Energy Technology Data Exchange (ETDEWEB)

    Hafsa, Noor E.; Arndt, David; Wishart, David S., E-mail: david.wishart@ualberta.ca [University of Alberta, Department of Computing Science (Canada)

    2015-07-15

    Accessible surface area (ASA) is the surface area of an atom, amino acid or biomolecule that is exposed to solvent. The calculation of a molecule’s ASA requires three-dimensional coordinate data and the use of a “rolling ball” algorithm to both define and calculate the ASA. For polymers such as proteins, the ASA for individual amino acids is closely related to the hydrophobicity of the amino acid as well as its local secondary and tertiary structure. For proteins, ASA is a structural descriptor that can often be as informative as secondary structure. Consequently there has been considerable effort over the past two decades to try to predict ASA from protein sequence data and to use ASA information (derived from chemical modification studies) as a structure constraint. Recently it has become evident that protein chemical shifts are also sensitive to ASA. Given the potential utility of ASA estimates as structural constraints for NMR we decided to explore this relationship further. Using machine learning techniques (specifically a boosted tree regression model) we developed an algorithm called “ShiftASA” that combines chemical-shift and sequence derived features to accurately estimate per-residue fractional ASA values of water-soluble proteins. This method showed a correlation coefficient between predicted and experimental values of 0.79 when evaluated on a set of 65 independent test proteins, which was an 8.2 % improvement over the next best performing (sequence-only) method. On a separate test set of 92 proteins, ShiftASA reported a mean correlation coefficient of 0.82, which was 12.3 % better than the next best performing method. ShiftASA is available as a web server ( http://shiftasa.wishartlab.com http://shiftasa.wishartlab.com ) for submitting input queries for fractional ASA calculation.

  3. The role of advanced reactive surface area characterization in improving predictions of mineral reaction rates

    Science.gov (United States)

    Beckingham, L. E.; Zhang, S.; Mitnick, E.; Cole, D. R.; Yang, L.; Anovitz, L. M.; Sheets, J.; Swift, A.; Kneafsey, T. J.; Landrot, G.; Mito, S.; Xue, Z.; Steefel, C. I.; DePaolo, D. J.; Ajo Franklin, J. B.

    2014-12-01

    Geologic sequestration of CO2 in deep sedimentary formations is a promising means of mitigating carbon emissions from coal-fired power plants but the long-term fate of injected CO2 is challenging to predict. Reactive transport models are used to gain insight over long times but rely on laboratory determined mineral reaction rates that have been difficult to extrapolate to field systems. This, in part, is due to a lack of understanding of mineral reactive surface area. Many models use an arbitrary approximation of reactive surface area, applying orders of magnitude scaling factors to measured BET or geometric surface areas. Recently, a few more sophisticated approaches have used 2D and 3D image analyses to determine mineral-specific reactive surface areas that account for the accessibility of minerals. However, the ability of these advanced surface area estimates to improve predictions of mineral reaction rates has yet to be determined. In this study, we fuse X-ray microCT, SEM QEMSCAN, XRD, SANS, and SEM-FIB analysis to determine mineral-specific accessible reactive surface areas for a core sample from the Nagaoka pilot CO2 injection site (Japan). This sample is primarily quartz, plagioclase, smectite, K-feldspar, and pyroxene. SEM imaging shows abundant smectite cement and grain coatings that decrease the fluid accessibility of other minerals. However, analysis of FIB-SEM images reveals that smectite nano-pores are well connected such that access to underlying minerals is not occluded by smectite coatings. Mineral-specific accessible surfaces are determined, accounting for the connectivity of the pore space with and without connected smectite nano-pores. The large-scale impact of variations in accessibility and dissolution rates are then determined through continuum scale modeling using grid-cell specific information on accessible surface areas. This approach will be compared with a traditional continuum scale model using mineral abundances and common surface area

  4. Pore scale heterogeneity in the mineral distribution and reactive surface area of rocks

    Science.gov (United States)

    Lai, P. E.; Krevor, S. C.

    2013-12-01

    There are long-standing challenges in characterizing reactive transport in porous media at scales larger than individual pores. This hampers the prediction of the field-scale impact of geochemical processes on fluid flow [1]. This is a source of uncertainty for CO2 injection, which results in a reactive fluid-rock system, particularly in carbonate rock reservoirs. A potential cause is the inability of the continuum approach to incorporate the impact of heterogeneity in pore-scale reaction rates. This results in part from pore-scale heterogeneities in surface area of reactive minerals [2,3]. In this study we have created μm resolution 3D images of 3 sandstone and 4 carbonate rocks using x-ray microtomography. Using in-house image processing techniques and auxiliary characterisation with thin section, electron microscope and spectroscopic techniques we quantified the surface area of each mineral phase in the x-ray CT images. This quantification was validated against N2 BET surface area and He porosity measurements of the imaged samples. Distributions in reactive surface area for each mineral phase were constructed by calculating surface areas in thousands of randomly selected subvolume images of the total sample, each normalized to the pore volume in that image. In all samples, there is little correlation between the reactive surface area fraction and the volumetric fraction of a mineral in a bulk rock. Berea sandstone was far less heterogeneous and has a characteristic pore size at which a surface area distribution may be used to quantify heterogeneity. In carbonates, heterogeneity is more complex and surface area must be characterized at multiple length scales for an accurate description of reactive transport. [1] Maher, Steefel, Depaolo and Vianni (2006) Geochimica et Cosmochimica Acta, 70, 337-363 [2] Landrot, Ajo-Franklin, Yang, Cabrini and Steefel (2012) Chemical Geology 318-319, 113-125 [3] Li, Peters and Celia (2007) American Journal of Science 307, 1146

  5. Body surface area formulae: an alarming ambiguity.

    Science.gov (United States)

    Redlarski, Grzegorz; Palkowski, Aleksander; Krawczuk, Marek

    2016-06-21

    Body surface area (BSA) plays a key role in several medical fields, including cancer chemotherapy, transplantology, burn treatment and toxicology. BSA is often a major factor in the determination of the course of treatment and drug dosage. A series of formulae to simplify the process have been developed. Because easy-to-identify, yet general, body coefficient results of those formulae vary considerably, the question arises as to whether the choice of a particular formula is valid and safe for patients. Here we show that discrepancies between most of the known BSA formulae can reach 0.5 m(2) for the standard adult physique. Although many previous studies have demonstrated that certain BSA formulae provide an almost exact fit with the patients examined, all of these studies have been performed on a limited and isolated group of people. Our analysis presents a broader perspective, considering 25 BSA formulae. The analysis revealed that the choice of a particular formula is a difficult task. Differences among calculations made by the formulae are so great that, in certain cases, they may considerably affect patients' mortality, especially for people with an abnormal physique or for children.

  6. Casimir effect in dielectrics Surface area contribution

    CERN Document Server

    Molina-Paris, C; Molina-Paris, Carmen; Visser, Matt

    1997-01-01

    In this paper we take a deeper look at the technically elementary but physically robust viewpoint in which the Casimir energy in dielectric media is interpreted as the change in the total zero point energy of the electromagnetic vacuum summed over all states. Extending results presented in previous papers [hep-th/9609195; hep-th/9702007] we approximate the sum over states by an integral over the density of states including finite volume corrections. For an arbitrarily-shaped finite dielectric, the first finite-volume correction to the density of states is shown to be proportional to the surface area of the dielectric interface and is explicitly evaluated as a function of the permeability and permitivity. Since these calculations are founded in an elementary and straightforward way on the underlying physics of the Casimir effect they serve as an important consistency check on field-theoretic calculations. As a concrete example we discuss Schwinger's suggestion that the Casimir effect might be the underlying ph...

  7. Method for treatment of a surface area of steel

    NARCIS (Netherlands)

    Bhowmik, S.; Aaldert, P.J.

    2009-01-01

    The invention relates to a method for treatment of a surface area of steel by polishing said surface area and performing a plasma treatment of said surface area wherein the plasma treatment is performed at at least atmospheric conditions and wherein the plasma treatment is carried out at a power of

  8. Metal-Free Counter Electrode for Efficient Dye-Sensitized Solar Cells through High Surface Area and Large Porous Carbon

    Directory of Open Access Journals (Sweden)

    Pavuluri Srinivasu

    2011-01-01

    Full Text Available Highly efficient, large mesoporous carbon is fabricated as a metal-free counter electrode for dye-sensitized solar cells. The mesoporous carbon shows very high energy conversion efficiency of 7.1% compared with activated carbon. The mesoporous carbon is prepared and characterized by nitrogen adsorption, scanning electron microscopy (SEM, and transmission electron microscopy (TEM. The nitrogen adsorption data reveals that the material possesses BET specific surface area ca.1300 m2/g and pore diameter 4.4 nm. Hexagonal rod-like morphology and ordered pore structure of mesoporous carbon are confirmed by electron microscopy data. The better performance of this carbon material is greatly benefited from its ordered interconnected mesoporous structure and high surface area.

  9. Pore Scale Heterogeneity in the Mineral Distribution, Surface Area and Adsorption in Porous Rocks

    Science.gov (United States)

    Lai, P. E. P.; Krevor, S. C.

    2014-12-01

    The impact of heterogeneity in chemical transport and reaction is not understood in continuum (Darcy/Fickian) models of reactive transport. This is manifested in well-known problems such as scale dependent dispersion and discrepancies in reaction rate observations made at laboratory and field scales [1]. Additionally, this is a source of uncertainty for carbon dioxide injection, which produces a reactive fluid-rock system particularly in carbonate rock reservoirs. A potential cause is the inability of the continuum approach to incorporate the impact of heterogeneity in pore-scale reaction rates. This results in part from pore-scale heterogeneities in surface area of reactive minerals [2, 3]. We use x-ray micro tomography to describe the non-normal 3-dimensional distribution of reactive surface area within a porous medium according to distinct mineral groups. Using in-house image processing techniques, thin sections, nitrogen BET surface area, backscattered electron imaging and energy dispersive spectroscopy, we compare the surface area of each mineral phase to those obtained from x-ray CT imagery. In all samples, there is little correlation between the reactive surface area fraction and the volumetric fraction of a mineral in a bulk rock. Berea sandstone was far less heterogeneous and has a characteristic pore size at which a surface area distribution may be used to quantify heterogeneity. In carbonates, heterogeneity is more complex and surface area must be characterized at multiple length scales for an accurate description of reactive transport. We combine the mineral specific surface area characterisation to dynamic tomography, imaging the flow of water and solutes, to observe flow dependent and mineral specific adsorption. The observations may contribute to the incorporation of experimentally based statistical descriptions of pore scale heterogeneity in reactive transport into upscaled models, moving it closer to predictive capabilities for field scale

  10. The increase of surface area of a Brazilian palygorskite clay activated with sulfuric acid solutions using a factorial design

    Directory of Open Access Journals (Sweden)

    R. N. Oliveira

    2013-01-01

    Full Text Available Palygorskite is fibrous clay in which the structural tetrahedral and octahedral layers are organized in a way that structural channels are formed, leading to high surface area. However, impurities inside the channels and aggregated ones considerably reduce the available area. In order to increase the surface area, an activation treatment can be considered useful. The goal of this work is the activation of palygorskite from Guadalupe, Piauí, via sulfuric acid treatment using a two-level factorial design. The influence of three parameters (solution molarity, temperature and time on BET surface area was determined. Moreover, samples were characterized via X-ray diffraction (XRD and fluorescence (XRF, Fourier-transform infrared spectroscopy (FTIR and transmission electron microscopy (TEM. The largest surface area (282 m²/g without considerable changes in clay structure and morphology was found in a sample treated with 5M H2SO4 at 70°C for 1h. The main parameters that favored the improvement of the surface area were the solution's molarity, temperature and their interaction.

  11. Ancient shell industry at Bet Dwarka island

    Digital Repository Service at National Institute of Oceanography (India)

    Gaur, A.S.; Sundaresh; Patankar, V.

    medicinal use. Several other varieties of shells from different trenches Table 1. Shells recovered during Bet Dwarka excav a tion Species BDK - I BDK - II BDK - III BDK - VI Adusta onyx 1 Anadara ehrenbergi 1 4 1...

  12. Effects of expertise on football betting

    OpenAIRE

    2012-01-01

    Abstract Background Football (soccer) is one of the most popular sports in the world, including Europe. It is associated with important betting activities. A common belief, widely spread among those who participate in gambling activities, is that knowledge and expertise on football lead to better prediction skills for match outcomes. If unfounded, however, this belief should be considered as a form of “illusion of control.” The aim of this study was to examine whether football experts are bet...

  13. Onshore excavation at Bet Dwarka Island, in the Gulf of Kachchh, Gujarat

    Digital Repository Service at National Institute of Oceanography (India)

    Gaur, A; Sundaresh

    Several ancient habitational sites were discovered in the coastal area of Bet Dwarka island during the last two decades of marine archaeological exploration. A large amount of protohistoric and historical pottery was collected from the sites...

  14. Influence of wet oxidation on the surface area and the porosity of some lignites

    Energy Technology Data Exchange (ETDEWEB)

    Yaman, S.; Karatepe, N.; Kucukbayrak, S. [Istanbul Technical University, Istanbul (Turkey). Chemical and Metallurgical Engineering Faculty

    2000-07-01

    Influence of wet oxidation on the surface area and the porosity of lignites was investigated using five different Turkish lignites. Lignite samples were oxidised in aqueous medium in a 1 l Parr autoclave at 423 K under 1.5 MPa partial pressure of oxygen for 60 min. Some physical properties such as surface area, bulk density, apparent density, mean pore radius, and porosity of the original and oxidised lignite samples were determined. For this purpose, BET and mercury intrusion porosimetry techniques were performed. In order to examine the effects of oxidation on the functional groups, FT-IR technique was applied for both original and oxidised lignite samples. On the other hand, some inorganic constituents were eliminated from the samples as a result of in situ formation of sulphuric acid from oxidation of sulphur compounds. The changes taken place in the physical properties were studied considering chemical compositions of the samples and the extent of the interaction between the samples and oxygen. 6 refs., 3 figs., 5 tabs.

  15. Reduction Expansion Synthesis as Strategy to Control Nitrogen Doping Level and Surface Area in Graphene

    Directory of Open Access Journals (Sweden)

    Russell Canty

    2015-10-01

    Full Text Available Graphene sheets doped with nitrogen were produced by the reduction-expansion (RES method utilizing graphite oxide (GO and urea as precursor materials. The simultaneous graphene generation and nitrogen insertion reactions are based on the fact that urea decomposes upon heating to release reducing gases. The volatile byproducts perform two primary functions: (i promoting the reduction of the GO and (ii providing the nitrogen to be inserted in situ as the graphene structure is created. Samples with diverse urea/GO mass ratios were treated at 800 °C in inert atmosphere to generate graphene with diverse microstructural characteristics and levels of nitrogen doping. Scanning electron microscopy (SEM and transmission electron microscopy (TEM were used to study the microstructural features of the products. The effects of doping on the samples structure and surface area were studied by X-ray diffraction (XRD, Raman Spectroscopy, and Brunauer Emmet Teller (BET. The GO and urea decomposition-reduction process as well as nitrogen-doped graphene stability were studied by thermogravimetric analysis (TGA coupled with mass spectroscopy (MS analysis of the evolved gases. Results show that the proposed method offers a high level of control over the amount of nitrogen inserted in the graphene and may be used alternatively to control its surface area. To demonstrate the practical relevance of these findings, as-produced samples were used as electrodes in supercapacitor and battery devices and compared with conventional, thermally exfoliated graphene.

  16. 30 CFR 56.17001 - Illumination of surface working areas.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Illumination of surface working areas. 56.17001... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Illumination § 56.17001 Illumination of surface working areas. Illumination sufficient to provide safe...

  17. SurfaceWater Source Protection Areas (SPAs)

    Data.gov (United States)

    Vermont Center for Geographic Information — Source Protection Area (SPA) boundaries have been located on RF 24000 & RF 25000 scale USGS topographic maps by Water Supply Division (DEC) and VT Dept of Health...

  18. The Bromodomain and Extra-Terminal Domain (BET Family: Functional Anatomy of BET Paralogous Proteins

    Directory of Open Access Journals (Sweden)

    Yasushi Taniguchi

    2016-11-01

    Full Text Available The Bromodomain and Extra-Terminal Domain (BET family of proteins is characterized by the presence of two tandem bromodomains and an extra-terminal domain. The mammalian BET family of proteins comprises BRD2, BRD3, BRD4, and BRDT, which are encoded by paralogous genes that may have been generated by repeated duplication of an ancestral gene during evolution. Bromodomains that can specifically bind acetylated lysine residues in histones serve as chromatin-targeting modules that decipher the histone acetylation code. BET proteins play a crucial role in regulating gene transcription through epigenetic interactions between bromodomains and acetylated histones during cellular proliferation and differentiation processes. On the other hand, BET proteins have been reported to mediate latent viral infection in host cells and be involved in oncogenesis. Human BRD4 is involved in multiple processes of the DNA virus life cycle, including viral replication, genome maintenance, and gene transcription through interaction with viral proteins. Aberrant BRD4 expression contributes to carcinogenesis by mediating hyperacetylation of the chromatin containing the cell proliferation-promoting genes. BET bromodomain blockade using small-molecule inhibitors gives rise to selective repression of the transcriptional network driven by c-MYC These inhibitors are expected to be potential therapeutic drugs for a wide range of cancers. This review presents an overview of the basic roles of BET proteins and highlights the pathological functions of BET and the recent developments in cancer therapy targeting BET proteins in animal models.

  19. On semiautomatic estimation of surface area

    DEFF Research Database (Denmark)

    Dvorak, J.; Jensen, Eva B. Vedel

    2013-01-01

    . For convex particles, the estimator is equal to four times the area of the support set (flower set) of the particle transect. We study the statistical properties of the flower estimator and compare its performance to that of two discretizations of the flower estimator, namely the pivotal estimator...

  20. The Structural Features of Sports and Race Betting Inducements: Issues for Harm Minimisation and Consumer Protection.

    Science.gov (United States)

    Hing, Nerilee; Sproston, Kerry; Brook, Kate; Brading, Richard

    2016-09-08

    Minimal research has been published about inducements for sports and race betting, despite their ready availability and aggressive advertising. This paper aimed to document the range and structural features of these inducements, and analyse their alignment with the harm minimisation and consumer protection goals of responsible gambling. A scan of all inducements offered on the websites of 30 major race and sports betting brands located 223 separate inducements which we categorised into 15 generic types, all offering financial incentives to purchase. These comprised sign-up offers, refer-a-friend offers, happy hours, mobile betting bonuses, multi-bet offers, refund/stake-back offers, matching stakes/deposits, winnings paid for 'close calls', bonus or better odds, bonus or better winnings, competitions, reduced commission, free bets to selected punters, cash rebates and other free bets. All inducements were subject to numerous terms and conditions which were complex, difficult to find, and obscured by legalistic language. Play-through conditions of bonus bets were particularly difficult to interpret and failed basic requirements for informed choice. Website advertisements for inducements were prominently promoted but few contained a responsible gambling message. The results were analysed to generate 12 research propositions considered worthy of empirical research to inform much needed regulatory reform in this area.

  1. Mesopore control of high surface area NaOH-activated carbon.

    Science.gov (United States)

    Tseng, Ru-Ling

    2006-11-15

    Activated carbon with BET surface areas in a narrow range from 2318 to 2474 m2/g was made by soaking the char made from corncob in a concentrated NaOH solution at NaOH/char ratios from 3 to 6; the mesopore volumes of the activated carbon were significantly changed from 21 to 58%. The relationships between pore properties (Sp, Vpore, Vmicro/Vpore, Dp) and NaOH dosage were investigated. Comparisons between the methods of NaOH and KOH activation revealed that NaOH activation can suitably control the mesopore specific volume of the activated carbon. Elemental analysis revealed that the H/C and O/C values of the activated carbons of NaOH/char ratios from 3 to 6 were significantly lower. SEM observation of surface hole variation of the activated carbon ascertained that the reaction process was inner pore etching. Based on the above three measurements and experimental investigations, the assumption made by previous researchers, namely that NaOH and KOH produce similar results, was challenged. Furthermore, the adsorption kinetics was used to investigate the adsorption rate of an Elovich equation to determine the relationships between the adsorption behavior on larger molecules (dyes) and smaller molecules (phenols) and the pore structure of the activated carbon.

  2. Asphalt-derived high surface area activated porous carbons for carbon dioxide capture.

    Science.gov (United States)

    Jalilov, Almaz S; Ruan, Gedeng; Hwang, Chih-Chau; Schipper, Desmond E; Tour, Josiah J; Li, Yilun; Fei, Huilong; Samuel, Errol L G; Tour, James M

    2015-01-21

    Research activity toward the development of new sorbents for carbon dioxide (CO2) capture have been increasing quickly. Despite the variety of existing materials with high surface areas and high CO2 uptake performances, the cost of the materials remains a dominant factor in slowing their industrial applications. Here we report preparation and CO2 uptake performance of microporous carbon materials synthesized from asphalt, a very inexpensive carbon source. Carbonization of asphalt with potassium hydroxide (KOH) at high temperatures (>600 °C) yields porous carbon materials (A-PC) with high surface areas of up to 2780 m(2) g(-1) and high CO2 uptake performance of 21 mmol g(-1) or 93 wt % at 30 bar and 25 °C. Furthermore, nitrogen doping and reduction with hydrogen yields active N-doped materials (A-NPC and A-rNPC) containing up to 9.3% nitrogen, making them nucleophilic porous carbons with further increase in the Brunauer-Emmett-Teller (BET) surface areas up to 2860 m(2) g(-1) for A-NPC and CO2 uptake to 26 mmol g(-1) or 114 wt % at 30 bar and 25 °C for A-rNPC. This is the highest reported CO2 uptake among the family of the activated porous carbonaceous materials. Thus, the porous carbon materials from asphalt have excellent properties for reversibly capturing CO2 at the well-head during the extraction of natural gas, a naturally occurring high pressure source of CO2. Through a pressure swing sorption process, when the asphalt-derived material is returned to 1 bar, the CO2 is released, thereby rendering a reversible capture medium that is highly efficient yet very inexpensive.

  3. Novel Salt-Assisted Combustion Synthesis of High Surface Area Ceria Nanopowders by An Ethylene Glycol-Nitrate Combustion Process

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A novel salt-assisted combustion process with ethylene glycol as a fuel and nitrate as an oxidant to synthesize high surface area ceria nanopowders was reported. The effects of various tunable conditions, such as fuel-to-oxidant ratio, type of salts, and amount of added salts, on the characteristics of the as-prepared powders were investigated by X-ray diffraction, transmission electron microscopy and BET surface area measurement. A mechanism scheme was proposed to illustrate the possible formation processes of well-dispersed ceria nanoparticles in the salt-assisted combustion synthesis. It was verified that the simple introduction of leachable inert inorganic salts as an excellent agglomeration inhibitor into the redox mixture precursor leads to the formation of well-dispersed ceria particles with particle size in the range of 4~6 nm and a drastic increase in the surface area. The presence of KCl results in an over ten-fold increment in specific surface area from 14.10 m2·g-1 for the produced ceria powders via the conventional combustion synthesis process to 156.74 m2·g-1 for the product by the salt-assisted combustion synthesis process at the same molar ratio of ethylene glycol-nitrate.

  4. 30 CFR 57.17001 - Illumination of surface working areas.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Illumination of surface working areas. 57.17001 Section 57.17001 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Illumination § 57.17001 Illumination of surface working areas. Illumination sufficient to provide safe...

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

    Science.gov (United States)

    Hristova, Yulia; Zeytuncu, Yunus E.

    2016-01-01

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

  6. Low-Risk Investing without Industry Bets

    DEFF Research Database (Denmark)

    Asness, Clifford S.; Frazzini, Andrea; Heje Pedersen, Lasse

    2014-01-01

    The strategy of buying safe low-beta stocks while shorting (or underweighting) riskier high-beta stocks (“betting against beta”) has been shown to deliver significant risk-adjusted returns. Some have suggested, however, that such “low-risk investing” delivers high returns primarily because...

  7. 77 FR 50165 - Escape and Evacuation Plans for Surface Coal Mines, Surface Facilities and Surface Work Areas of...

    Science.gov (United States)

    2012-08-20

    ... Administration. Title: Escape and Evacuation Plans for Surface Coal Mines, Surface Facilities ] and Surface Work... Safety and Health Administration Escape and Evacuation Plans for Surface Coal Mines, Surface Facilities and Surface Work Areas of Underground Coal Mines AGENCY: Mine Safety and Health Administration,...

  8. Indexing aortic valve area by body surface area increases the prevalence of severe aortic stenosis

    DEFF Research Database (Denmark)

    Jander, Nikolaus; Gohlke-Bärwolf, Christa; Bahlmann, Edda

    2014-01-01

    To account for differences in body size in patients with aortic stenosis, aortic valve area (AVA) is divided by body surface area (BSA) to calculate indexed AVA (AVAindex). Cut-off values for severe stenosis are......To account for differences in body size in patients with aortic stenosis, aortic valve area (AVA) is divided by body surface area (BSA) to calculate indexed AVA (AVAindex). Cut-off values for severe stenosis are...

  9. MOISTURE AND SURFACE AREA MEASUREMENTS OF PLUTONIUM-BEARING OXIDES

    Energy Technology Data Exchange (ETDEWEB)

    Crowder, M.; Duffey, J.; Livingston, R.; Scogin, J.; Kessinger, G.; Almond, P.

    2009-09-28

    To ensure safe storage, plutonium-bearing oxides are stabilized at 950 C for at least two hours in an oxidizing atmosphere. Stabilization conditions are expected to decompose organic impurities, convert metals to oxides, and result in moisture content below 0.5 wt%. During stabilization, the specific surface area is reduced, which minimizes readsorption of water onto the oxide surface. Plutonium oxides stabilized according to these criteria were sampled and analyzed to determine moisture content and surface area. In addition, samples were leached in water to identify water-soluble chloride impurity content. Results of these analyses for seven samples showed that the stabilization process produced low moisture materials (< 0.2 wt %) with low surface area ({le} 1 m{sup 2}/g). For relatively pure materials, the amount of water per unit surface area corresponded to 1.5 to 3.5 molecular layers of water. For materials with chloride content > 360 ppm, the calculated amount of water per unit surface area increased with chloride content, indicating hydration of hygroscopic salts present in the impure PuO{sub 2}-containing materials. The low moisture, low surface area materials in this study did not generate detectable hydrogen during storage of four or more years.

  10. Salt-assisted Low Temperature Solid State Synthesis of High Surface Area CoFe2O4 Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    Runhua Qin; Fengsheng Li; Wei Jiang; Li Liu

    2009-01-01

    A novel salt-assisted low temperature solid state method using CoCl2·6H2O, FeCl3·6H2O and NaOH as pre-cursor and using NaCl as a dispersant to synthesize high surface area CoFe2O4 nanoparticles, has been investigated. The effects of the molar ratio of added salt and calcination temperature on the characteristics of the products were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and Brunauer, Emmett and Teller (BET) surface area analysis. Results showed that the introduction of leachable inert inorganic salt as a hard agglomeration inhibitor in the mixture precursorled to the formation of high dispersive CoFe2O4 nanoparticles; and the increase in specific surface area from 28.28 to 73.97 m2/g, and the saturation magnetization is 84.6 emu/g.

  11. Some Inequalities for Lp-mixed Affine Surface Area

    Institute of Scientific and Technical Information of China (English)

    ZHU Xian-yang

    2012-01-01

    In this paper,the concepts of the ith Lp-mixed affine surface area and Lp-polar curvature images are introduced,some new inequalities connecting these new notions with Lp-centroid bodies and p-Blaschke bodies are showed.Moreover,a Blaschke-Santaló type inequality for Lp-mixed affine surface area is established.Our results also imply the similar to the inequalities for Marcus-Lopes,Bergstrom and Ky Fan.

  12. High surface area carbon and process for its production

    Science.gov (United States)

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

    2016-12-13

    Activated carbon materials and methods of producing and using activated carbon materials are provided. In particular, biomass-derived activated carbon materials and processes of producing the activated carbon materials with prespecified surface areas and pore size distributions are provided. Activated carbon materials with preselected high specific surface areas, porosities, sub-nm (carbon consumption and metallic potassium intercalation into the carbon lattice during the activation process.

  13. Effective potential in the BET formalism

    CERN Document Server

    Bessa, A; Fraga, E S; Gelis, F

    2011-01-01

    We calculate the one-loop effective potential at finite temperature for a system of massless scalar fields with quartic interaction $\\lambda\\phi^4$ in the framework of the boundary effective theory (BET) formalism. The calculation relies on the solution of the classical equation of motion for the field, and Gaussian fluctuations around it. Our result is non-perturbative and differs from the standard one-loop effective potential for field values larger than $T/\\sqrt{\\lambda}$.

  14. Effects of expertise on football betting

    Directory of Open Access Journals (Sweden)

    Khazaal Yasser

    2012-05-01

    Full Text Available Abstract Background Football (soccer is one of the most popular sports in the world, including Europe. It is associated with important betting activities. A common belief, widely spread among those who participate in gambling activities, is that knowledge and expertise on football lead to better prediction skills for match outcomes. If unfounded, however, this belief should be considered as a form of “illusion of control.” The aim of this study was to examine whether football experts are better than nonexperts at predicting football match scores. Methods Two hundred and fifty-eight persons took part in the study: 21.3% as football experts, 54.3% as laypersons (non-initiated to football, and 24.4% as football amateurs. They predicted the scores of the first 10 matches of the 2008 UEFA European Football Championship. Logistic regressions were carried out to assess the link between the accuracy of the forecasted scores and the expertise of the participants (expert, amateur, layperson, controlling for age and gender. Results The variables assessed did not predict the accuracy of scoring prognosis (R2 ranged from 1% to 6%. Conclusions Expertise, age, and gender did not appear to have an impact on the accuracy of the football match prognoses. Therefore, the belief that football expertise improves betting skills is no more than a cognitive distortion called the “illusion of control.” Gamblers may benefit from psychological interventions that target the illusion of control related to their believed links between betting skills and football expertise. Public health policies may need to consider the phenomenon in order to prevent problem gambling related to football betting.

  15. Quantifying object and material surface areas in residences

    Energy Technology Data Exchange (ETDEWEB)

    Hodgson, Alfred T.; Ming, Katherine Y.; Singer, Brett C.

    2005-01-05

    The dynamic behavior of volatile organic compounds (VOCs) in indoor environments depends, in part, on sorptive interactions between VOCs in the gas phase and material surfaces. Since information on the types and quantities of interior material surfaces is not generally available, this pilot-scale study was conducted in occupied residences to develop and demonstrate a method for quantifying surface areas of objects and materials in rooms. Access to 33 rooms in nine residences consisting of bathrooms, bedroom/offices and common areas was solicited from among research group members living in the East San Francisco Bay Area. A systematic approach was implemented for measuring rooms and objects from 300 cm{sup 2} and larger. The ventilated air volumes of the rooms were estimated and surface area-to-volume ratios were calculated for objects and materials, each segregated into 20 or more categories. Total surface area-to-volume ratios also were determined for each room. The bathrooms had the highest total surface area-to-volume ratios. Bedrooms generally had higher ratios than common areas consisting of kitchens, living/dining rooms and transitional rooms. Total surface area-to-volume ratios for the 12 bedrooms ranged between 2.3 and 4.7 m{sup 2} m{sup -3}. The importance of individual objects and materials with respect to sorption will depend upon the sorption coefficients for the various VOC/materials combinations. When combined, the highly permeable material categories, which may contribute to significant interactions, had a median ratio of about 0.5 m{sup 2} m{sup -3} for all three types of rooms.

  16. Surface area considerations for corroding N reactor fuel

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, A.B. Jr.; Pitner, A.L.

    1996-06-01

    The N Reactor fuel is corroding at sites where the Zircaloy cladding was damaged when the fuel was discharged from the reactor. Corroding areas are clearly visible on the fuel stored in open cans in the K East Basin. There is a need to estimate the area of the corroding uranium to analyze aspects of fuel behavior as it is transitioned. from current wet storage to dry storage. In this report, the factors that contribute to {open_quotes}true{close_quotes} surface area are analyzed in terms of what is currently known about the N Reactor fuel. Using observations from a visual examinations of the fuel in the K East wet storage facility, a value for the corroding geometric area is estimated. Based on observations of corroding uranium and surface roughness values for other metals, a surface roughness factor is also estimated and applied to the corroding K East fuel to provide an estimated {open_quotes}true{close_quotes} surface area. While the estimated area may be modified as additional data become available from fuel characterization studies, the estimate provides a basis to assess effects of exposed uranium metal surfaces on fuel behavior in operations involved in transitioning from wet to dry storage, during shipment and staging, conditioning, and dry interim storage.

  17. Can foot anthropometric measurements predict dynamic plantar surface contact area?

    Directory of Open Access Journals (Sweden)

    Collins Natalie

    2009-10-01

    Full Text Available Abstract Background Previous studies have suggested that increased plantar surface area, associated with pes planus, is a risk factor for the development of lower extremity overuse injuries. The intent of this study was to determine if a single or combination of foot anthropometric measures could be used to predict plantar surface area. Methods Six foot measurements were collected on 155 subjects (97 females, 58 males, mean age 24.5 ± 3.5 years. The measurements as well as one ratio were entered into a stepwise regression analysis to determine the optimal set of measurements associated with total plantar contact area either including or excluding the toe region. The predicted values were used to calculate plantar surface area and were compared to the actual values obtained dynamically using a pressure sensor platform. Results A three variable model was found to describe the relationship between the foot measures/ratio and total plantar contact area (R2 = 0.77, p R2 = 0.76, p Conclusion The results of this study indicate that the clinician can use a combination of simple, reliable, and time efficient foot anthropometric measurements to explain over 75% of the plantar surface contact area, either including or excluding the toe region.

  18. Observed Asteroid Surface Area in the Thermal Infrared

    Science.gov (United States)

    Nugent, C. R.; Mainzer, A.; Masiero, J.; Wright, E. L.; Bauer, J.; Grav, T.; Kramer, E.; Sonnett, S.

    2017-02-01

    The rapid accumulation of thermal infrared observations and shape models of asteroids has led to increased interest in thermophysical modeling. Most of these infrared observations are unresolved. We consider what fraction of an asteroid’s surface area contributes the bulk of the emitted thermal flux for two model asteroids of different shapes over a range of thermal parameters. The resulting observed surface in the infrared is generally more fragmented than the area observed in visible wavelengths, indicating high sensitivity to shape. For objects with low values of the thermal parameter, small fractions of the surface contribute the majority of thermally emitted flux. Calculating observed areas could enable the production of spatially resolved thermal inertia maps from non-resolved observations of asteroids.

  19. STEREOLOGICAL ESTIMATION OF SURFACE AREA FROM DIGITAL IMAGES

    Directory of Open Access Journals (Sweden)

    Johanna Ziegel

    2011-05-01

    Full Text Available A sampling design of local stereology is combined with a method from digital stereology to yield a novel estimator of surface area based on counts of configurations observed in a digitization of an isotropic 2- dimensional slice with thickness s. As a tool, a result of the second author and J. Rataj on infinitesimal increase of volumes of morphological transforms is refined and used. The proposed surface area estimator is asymptotically unbiased in the case of sets contained in the ball centred at the origin with radius s and in the case of balls centred at the origin with unknown radius. For general shapes bounds for the asymptotic expected relative worst case error are given. A simulation example is discussed for surface area estimation based on 2×2×2-configurations.

  20. High surface area carbon and process for its production

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-12-13

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

  1. Clay mineralogy in different geomorphic surfaces in sugarcane areas

    Science.gov (United States)

    Camargo, L.; Marques, J., Jr.

    2012-04-01

    The crystallization of the oxides and hydroxides of iron and aluminum and kaolinite of clay fraction is the result of pedogenetic processes controlled by the relief. These minerals have influence on the physical and chemical attributes of soil and exhibit spatial dependence. The pattern of spatial distribution is influenced by forms of relief as the geomorphic surfaces. In this sense, the studies aimed at understanding the relationship between relief and the distribution pattern of the clay fraction attributes contribute to the delineation of specific areas of management in the field. The objective of this study was to evaluate the spatial distribution of oxides and hydroxides of iron and aluminum and kaolinite of clay fraction and its relationship with the physical and chemical attributes in different geomorphic surfaces. Soil samples were collected in a transect each 25 m (100 samples) and in the sides of the same (200 samples) as well as an area of 500 ha (1 sample each six hectare). Geomorphic surfaces (GS) in the transect were mapped in detail to support mapping the entire area. The soil samples were taken to the laboratory for chemical, physical, and mineralogical analysis, and the pattern of spatial distribution of soil attributes was obtained by statistics and geostatistics. The GS I is considered the oldest surface of the study area, with depositional character, and a slope ranging from 0 to 4%. GS II and III are considered to be eroded, and the surface II plan a gentle slope that extends from the edge of the surface until the beginning of I and III. The crystallographic characteristics of the oxides and hydroxides of iron and aluminum and kaolinite showed spatial dependence and the distribution pattern corresponding to the limits present of the GS in the field. Surfaces I and II showed the best environments to the degree of crystallinity of hematite and the surface III to the greatest degree of crystallinity of goethite agreeing to the pedoenvironment

  2. Synthesis of zinc aluminate with high surface area by microwave hydrothermal method applied in the transesterification of soybean oil (biodiesel)

    Energy Technology Data Exchange (ETDEWEB)

    Quirino, M.R. [Chemistry Laboratory of Federal University of Paraiba (LABQUIM), Campus III, 58200-000 Bananeiras, PB (Brazil); Oliveira, M.J.C. [Academic Unit of Materials Engineering, UFCG, Campina Grande Campus I, 58429-900 Campina Grande, PB (Brazil); Keyson, D. [Laboratory of study in Science, DME, Federal University of Paraíba, Campus I, 58051-900 João Pessoa, PB (Brazil); Lucena, G.L., E-mail: guilherme_leo1@yahoo.com.br [Chemistry Laboratory of Federal University of Paraiba (LABQUIM), Campus III, 58200-000 Bananeiras, PB (Brazil); Oliveira, J.B.L. [Federal University of Rio Grande do Norte, UFRN, Campus I, 59078-970 Natal, RN (Brazil); Gama, L. [Academic Unit of Materials Engineering, UFCG, Campina Grande Campus I, 58429-900 Campina Grande, PB (Brazil)

    2016-02-15

    Highlights: • ZnAl{sub 2}O{sub 4} spinel was synthesized by the microwave hydrothermal method in only 15 or 30 min. • The powders show high specific surface area. • ZAT{sub b}15 showed activity of 52.22% for the conversion of soybean oil into biodiesel. - Abstract: Zinc aluminate is a material with high thermal stability and high mechanical strength that, owing to these properties, is used as a catalyst or support. In this work, zinc aluminate spinel was synthesized by the microwave hydrothermal method in only 15 or 30 min at a low temperature (150 °C) without templates, using only Al(NO{sub 3}){sub 3}·9H{sub 2}O, Zn(NO{sub 3}){sub 2}·6H{sub 2}O, and urea as precursors and applied in the transesterification of soybean oil. X-ray diffraction analysis showed that ZnAl{sub 2}O{sub 4} had a cubic structure without secondary phases. The nitrogen adsorption measurements (BET) revealed a high surface area (266.57 m{sup 2} g{sup −1}) for the nanopowder synthesized in 15 min. This powder showed activity of 52.22% for the catalytic conversion of soybean oil into biodiesel by transesterification.

  3. A facile approach for high surface area electrospun TiO2 nanostructures for photovoltaic and photocatalytic applications.

    Science.gov (United States)

    Arun, T A; Madhavan, Asha Anish; Chacko, Daya K; Anjusree, G S; Deepak, T G; Thomas, Sara; Nair, Shantikumar V; Nair, A Sreekumaran

    2014-03-28

    A rice-shaped TiO2-ZnO composite was prepared by electrospinning a mixture comprising the precursors of TiO2 and ZnO in polyvinyl acetate polymer dissolved in N,N-dimethyl acetamide. The electrospun nanofibers upon heat treatment in air resulted in collapse of the continuous fiber morphology and the formation of the rice-shaped TiO2-ZnO composite. The TiO2-ZnO composite was then treated with dilute acetic acid under hydrothermal conditions to etch ZnO from the TiO2-ZnO composite to get coral-shaped anisotropic TiO2. The structural anisotropy of TiO2 produced by the selective etching of ZnO resulted in a high surface area of 148 m(2) g(-1) for the TiO2. The initial and final materials were characterized by scanning electron microscopy, transmission electron microscopy, Raman and XPS spectroscopies, powder X-ray diffraction and BET surface area measurements. The utility of the anisotropic TiO2 in photovoltaics and photocatalysis was explored. Dye-sensitized solar cells fabricated using the TiO2 showed a conversion efficiency of 6.54% as against 4.8% for a control experiment with the rice-shaped TiO2. The anisotropic TiO2 also showed good photocatalysis in the degradation of methyl orange dye and phenol.

  4. Characterization of large area nanostructured surfaces using AFM measurements

    DEFF Research Database (Denmark)

    Calaon, Matteo; Hansen, Hans Nørgaard; Tosello, Guido;

    2012-01-01

    magnitude of the 3D surface amplitude parameters chosen for the analysis, when increasing the Al purity from 99,5% to 99,999%. AFM was then employed to evaluate the periodical arrangements of the nano structured cells. Image processing was used to estimate the average areas value, the height variation...

  5. Stereological estimation of surface area from digital images

    DEFF Research Database (Denmark)

    Ziegel, Johanna; Kiderlen, Markus

    2010-01-01

    A sampling design of local stereology is combined with a method from digital stereology to yield a novel estimator of surface area based on counts of configurations observed in a digitization of an isotropic 2- dimensional slice with thickness s. As a tool, a result of the second author and J. Ra....... For general shapes bounds for the asymptotic expected relative worst case error are given. A simulation example is discussed for surface area estimation based on 2×2×2-configurations.......A sampling design of local stereology is combined with a method from digital stereology to yield a novel estimator of surface area based on counts of configurations observed in a digitization of an isotropic 2- dimensional slice with thickness s. As a tool, a result of the second author and J....... Rataj on infinitesimal increase of volumes of morphological transforms is refined and used. The proposed surface area estimator is asymptotically unbiased in the case of sets contained in the ball centred at the origin with radius s and in the case of balls centred at the origin with unknown radius...

  6. Effect of milling temperatures on surface area, surface energy and cohesion of pharmaceutical powders.

    Science.gov (United States)

    Shah, Umang V; Wang, Zihua; Olusanmi, Dolapo; Narang, Ajit S; Hussain, Munir A; Tobyn, Michael J; Heng, Jerry Y Y

    2015-11-10

    Particle bulk and surface properties are influenced by the powder processing routes. This study demonstrates the effect of milling temperatures on the particle surface properties, particularly surface energy and surface area, and ultimately on powder cohesion. An active pharmaceutical ingredient (API) of industrial relevance (brivanib alaninate, BA) was used to demonstrate the effect of two different, but most commonly used milling temperatures (cryogenic vs. ambient). The surface energy of powders milled at both cryogenic and room temperatures increased with increasing milling cycles. The increase in surface energy could be related to the generation of surface amorphous regions. Cohesion for both cryogenic and room temperature milled powders was measured and found to increase with increasing milling cycles. For cryogenic milling, BA had a surface area ∼ 5× higher than the one obtained at room temperature. This was due to the brittle nature of this compound at cryogenic temperature. By decoupling average contributions of surface area and surface energy on cohesion by salinization post-milling, the average contribution of surface energy on cohesion for powders milled at room temperature was 83% and 55% at cryogenic temperature.

  7. Betting strategies on fluctuations in the transient response of greenhouse warming.

    Science.gov (United States)

    Risbey, James S; Lewandowsky, Stephan; Hunter, John R; Monselesan, Didier P

    2015-11-28

    We examine a series of betting strategies on the transient response of greenhouse warming, expressed by changes in 15-year mean global surface temperature from one 15-year period to the next. Over the last century, these bets are increasingly dominated by positive changes (warming), reflecting increasing greenhouse forcing and its rising contribution to temperature changes on this time scale. The greenhouse contribution to 15-year trends is now of a similar magnitude to typical naturally occurring 15-year trends. Negative 15-year changes (decreases) have not occurred since about 1970, and are still possible, but now rely on large, and therefore infrequent, natural variations. Model projections for even intermediate warming scenarios show very low likelihoods of obtaining negative 15-year changes over the coming century. Betting against greenhouse warming, even on these short time scales, is no longer a rational proposition.

  8. Nanocrystalline GaSbO{sub 4} with high surface area prepared via a facile hydrothermal method and its photocatalytic activity study

    Energy Technology Data Exchange (ETDEWEB)

    Fu Yanghe; Xue Hun; Qin Meng; Liu Ping; Fu Xianzhi [Research Institute of Photocatalysis, Fujian Provincial Key Laboratory of Photocatalysis - State Key Laboratory Breeding Base, Fuzhou University, Fuzhou 350002 (China); Li Zhaohui, E-mail: zhaohuili1969@yahoo.com [Research Institute of Photocatalysis, Fujian Provincial Key Laboratory of Photocatalysis - State Key Laboratory Breeding Base, Fuzhou University, Fuzhou 350002 (China)

    2012-05-05

    Graphical abstract: Nanocrystalline GaSbO{sub 4} prepared via a facile hydrothermal method possesses large specific surface area and exhibits photocatalytic activity for the degradations of salicylic acid and acetone. Highlights: Black-Right-Pointing-Pointer Facile hydrothermal method to nanocrystalline GaSbO{sub 4} with large surface area. Black-Right-Pointing-Pointer GaSbO{sub 4} shows photocatalytic activity for the degradations of salicylic acid and acetone. Black-Right-Pointing-Pointer The photocatalytic mechanism of GaSbO{sub 4} was proposed based on the ESR result. - Abstract: Nanocrystalline GaSbO{sub 4} with small particle size and large BET specific area was successfully prepared via a facile hydrothermal method from Sb{sub 2}O{sub 5}. The influence of the reaction pH on the formation of the final product was investigated. The obtained sample was characterized by X-ray diffraction (XRD), N{sub 2}-sorption BET surface area, UV-vis diffuse reflectance spectroscopy (DRS), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM). The photocatalytic activity for the degradations of salicylic acid and acetone over nanocrystalline GaSbO{sub 4} under UV irradiations was for the first time revealed. Based on the electron spin resonance (ESR) result, the reactive species involved in the photocatalytic reaction over nanocrytalline GaSbO{sub 4} are determined to be HO{center_dot} and O{sub 2}{sup -}{center_dot}. The photocatalytic mechanism of GaSbO{sub 4} was proposed.

  9. Experimental Political Betting Markets and the 2004 Election.

    OpenAIRE

    Wolfers, Justin; Zitzewitz, Eric

    2004-01-01

    Betting on elections has been of interest to economists and political scientists for some time. We recently persuaded TradeSports to run experimental contingent betting markets, in which one bets on whether President Bush will be re-elected, conditional on other specified events occurring. Early results suggest that market participants strongly believe that Osama bin Laden's capture would have a substantial effect on President Bush's electoral fortunes, and interestingly that the chance of hi...

  10. Surface area and conductivity of polyaniline synthesized under UV irradiation

    Science.gov (United States)

    Budi, S.; Fitri, E.; Paristiowati, M.; Cahyana, U.; Pusparini, E.; Nasbey, H.; Imaddudin, A.

    2017-02-01

    This paper reports our study on the synthesis of high electrical conductivity and surface area polyaniline using oxidative polymerization under UV light irradiation. The formation of emeraldine structures of polyaniline was revealed by major absorption bands of FTIR (Fourier transform infrared spectroscopy) spectra attributed to C-N stretching, C=C stretching in the benzenoid ring, C=C stretching in the quinoid ring and QNH+B stretching. XRD (X-ray diffractometer) measurements confirmed typical diffraction patterns with a crystallinity of 13% and 16% for polyaniline prepared under non-stirred and stirred reaction, respectively. SEM (Scanning electron microscope) studies showed more uniform morphology of polyaniline was obtained with stirring reaction process compare to those prepared without stirring. Surface analysis using SAA (surface area analyzer) showed that pure polyaniline with the relatively high surface area of ca.28 m2/g was successfully prepared in this work. Based on four point probe measurement, the prepared polyaniline possesses high conductivity which is important in electrode application.

  11. A Novel Way to Prepare TiO2 and γ-Al2O3 Supported Catalysts with Large Surface Areas

    Institute of Scientific and Technical Information of China (English)

    ZHU Yue-Xiang ZHU Yue-Xiang; ZHAO Bi-Ying; ZHOU Chang-Jun; WANG Rong-Qiu; XIE You-Chang

    2001-01-01

    pared by a novel way and characterized by X-ray diffractiou,Raman spectroscopy and BET surface area measurement.The results show: (1) all the samples,including M0O3/TiO2,WO3/TiO2, V2Os/TiO2, FeSO4/γ-Al2O3, Al2(SO4)3/γ-Al2O3,K2CO3/-Al2O3 and so on,prepared by impregnating TiO2·H20or pseudo-boehmite AlO(OH)with the active components them calcining at a high temperature exhibit much larger surface ar-eas than that of pure TiO2 or γ-Al2O3 calcined at the same tem-perature; (2) the surface area of the sample increases with the increase in the coverage of active component on the surface of the support; (3) when the content of active component reaches its utmost monolayer dispersion capacity, the surface area of the sample is the largest, and then decreases when the content of active component exceeds its dispersion threshold.

  12. DETERMINATION OF GLACIER SURFACE AREA USING SPACEBORNE SAR IMAGERY

    OpenAIRE

    Fang, L.; Maksymiuk, O.; Schmitt, M.; Stilla, U.

    2013-01-01

    Glaciers are very important climate indicators. Although visible remote sensing techniques can be used to extract glacier variations effectively and accurately, the necessary data are depending on good weather conditions. In this paper, a method for determination of glacier surface area using multi-temporal and multi-angle high resolution TerraSAR-X data sets is presented. We reduce the "data holes" in the SAR scenes affected by radar shadowing and specular backscattering of smooth i...

  13. Excess Surface Area in Bioelectrochemical Systems Causes ion Transport Limitations

    Energy Technology Data Exchange (ETDEWEB)

    Harrington, Timothy D.; Babauta, Jerome T.; Davenport, Emily K.; Renslow, Ryan S.; Beyenal, Haluk

    2015-05-01

    We investigated ion transport limitations on 3D graphite felt electrodes by growing Geobacter sulfurreducens biofilms with advection to eliminate external mass transfer limitations. We characterized ion transport limitations by: (i) showing that serially increasing NaCl concentration up to 200mM increased current linearly up to a total of þ273% vs. 0mM NaCl under advective conditions; (ii) growing the biofilm with a starting concentration of 200mM NaCl, which led to a maximum current increase of 400% vs. current generation without NaCl, and (iii) showing that un-colonized surface area remained even after steadystate current was reached. After accounting for iR effects, we confirmed that the excess surface area existed despite a non-zero overpotential. The fact that the biofilm was constrained from colonizing and producing further current under these conditions confirmed the biofilms under study here were ion transport-limited. Our work demonstrates that the use of high surface area electrodes may not increase current density when the system design allows ion transport limitations to become dominant.

  14. Determination of hand and palm area as a ratio of body surface area in Indian population

    Directory of Open Access Journals (Sweden)

    Agarwal Pawan

    2010-01-01

    Full Text Available Background: Accurate estimation of body surface area (BSA burn is important. In small and patchy burns, the patient′s hand is used to estimate percentage of burn which is traditionally considered as 1%. There is discrepancy about what percentage of TBSA is constituted by the palm and hand. Therefore, this study was designed to determine correctly the TBSA represented by the palmar surface of the entire hand and palm in the Indian population. Material and Methods: 300 healthy adult (male and female and 300 healthy children (male and female were included in the study. TBSA was calculated using DuBois formula and hand and palm surface area was calculated using hand tracing on plain paper. The hand/palm percentage of BSA (ratio was determined by dividing hand/palm surface area by total BSA. Results: The mean hand and palm ratio for adults was 0.92% and 0.50%, respectively. The mean hand and palm ratio in children was 1.06% and 0.632%, respectively. Conclusion: The hand area (palm plus digits is more closely represented to 1% of TBSA in Indian population.

  15. Spectral theory of infinite-area hyperbolic surfaces

    CERN Document Server

    Borthwick, David

    2016-01-01

    This text introduces geometric spectral theory in the context of infinite-area Riemann surfaces, providing a comprehensive account of the most recent developments in the field. For the second edition the context has been extended to general surfaces with hyperbolic ends, which provides a natural setting for development of the spectral theory while still keeping technical difficulties to a minimum. All of the material from the first edition is included and updated, and new sections have been added. Topics covered include an introduction to the geometry of hyperbolic surfaces, analysis of the resolvent of the Laplacian, scattering theory, resonances and scattering poles, the Selberg zeta function, the Poisson formula, distribution of resonances, the inverse scattering problem, Patterson-Sullivan theory, and the dynamical approach to the zeta function. The new sections cover the latest developments in the field, including the spectral gap, resonance asymptotics near the critical line, and sharp geometric constan...

  16. Determination of Glacier Surface Area Using Spaceborne SAR Imagery

    Science.gov (United States)

    Fang, L.; Maksymiuk, O.; Schmitt, M.; Stilla, U.

    2013-04-01

    Glaciers are very important climate indicators. Although visible remote sensing techniques can be used to extract glacier variations effectively and accurately, the necessary data are depending on good weather conditions. In this paper, a method for determination of glacier surface area using multi-temporal and multi-angle high resolution TerraSAR-X data sets is presented. We reduce the "data holes" in the SAR scenes affected by radar shadowing and specular backscattering of smooth ice surfaces by combining the two complementary different imaging geometries (from ascending and descending satellite tracks). Then, a set of suitable features is derived from the intensity image, the texture information generated based on the gray level co-occurrence matrix (GLCM), glacier velocity estimated by speckle tracking, and the interferometric coherence map. Furthermore, the features are selected by 10-foldcross- validation based on the feature relevance importance on classification accuracy using a Random Forests (RF) classifier. With these most relevant features, the glacier surface is discriminated from the background by RF classification in order to calculate the corresponding surface area.

  17. Exploring a novel approach to fabricate vanadium carbide encapsulated into carbon nanotube (VC@C) with large specific surface area

    Indian Academy of Sciences (India)

    Yifu Zhang; Juecheng Zhang; Meijuan Fan; Yan’an Long; Yalan Zhong; Xinghai Liu; Chi Huang

    2013-06-01

    A novel approach to the fabrication of vanadium carbide encapsulated into carbon nanotube (VC@C) core-shell structured composite by thermal treatment with the precursor V3O7.H2O@C was developed for the first time. The as-obtained VC@C were characterized by X-ray powder diffraction (XRD), Raman spectrum, energydispersive X-ray spectrometer (EDX), elemental analysis (EA), Fourier transform infrared spectroscopy (FT)–(IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Brunauer–Emmett–Teller (BET). The results showed that VC@C with core-shell structures could be successfully synthesized at 1000 °C for 2 h. The specific surface area, average pore size and measured pore volume of VC@C were 135.46 m2/g, 4.443 nm and 0.180 cm3/g, respectively indicating that the as-obtained VC@C composite could be used as a mesoporous material. Furthermore, thermal behaviour of the as-obtained VC@C composite in air was investigated by thermogravimetric/differential thermal analyser (TG/DTA). The experimental result revealed that the carbon coated on the surface of VC has high activity with O2 in air atmosphere.

  18. Structure, surface area and morphology of aluminas from thermal decomposition of Al(OH(CH3COO2 crystals

    Directory of Open Access Journals (Sweden)

    KIYOHARA PEDRO K.

    2000-01-01

    Full Text Available Crystalline aluminium hydroxiacetate was prepared by reaction between aluminium powder (ALCOA 123 and aqueous solution of acetic acid at 96ºC ±1ºC. The white powder of Al(OH(CH3COO2 is constituted by agglomerates of crystalline plates, having size about 10mum. The crystals were fired from 200ºC to 1550ºC, in oxidizing atmosphere and the products characterized by X-ray diffraction, scanning electron microscopy and surface area measurements by BET-nitrogen method. Transition aluminas are formed from heating at the following temperatures: gamma (300ºC; delta (750ºC; alpha (1050ºC. The aluminas maintain the original morphology of the Al(OHAc2 crystal agglomerates, up to 1050ºC, when sintering and coalescence of the alpha-alumina crystals start and proceed up to 1550ºC. High surface area aluminas are formed in the temperature range of 700ºC to 1100ºC; the maximum value of 198m²/g is obtained at 900ºC, with delta-alumina structure. The formation sequence of transition aluminas is similar to the sequence from well ordered boehmite, but with differences in the transition temperatures and in the development of high surface areas. It is suggested that the causes for these diversities between the two sequences from Al(OH Ac2 and boehmite are due to the different particle sizes, shapes and textures of the gamma-Al2O3 which acts as precursor for the sequence gamma- to alpha-Al2O3.

  19. 18 CFR 706.209 - Gambling, betting, and lotteries.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Gambling, betting, and... EMPLOYEE RESPONSIBILITIES AND CONDUCT Conduct and Responsibilities of Employees § 706.209 Gambling, betting... while on duty for the Government, in any gambling activity, including the operation of a gambling...

  20. 15 CFR 0.735-17 - Gambling, betting, and lotteries.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Gambling, betting, and lotteries. 0... RESPONSIBILITIES AND CONDUCT Regulatory Limitations Upon Employee Conduct § 0.735-17 Gambling, betting, and... for the Government, in any gambling activity including the operation of a gambling device,...

  1. STS-40 descent BET products: Development and results

    Science.gov (United States)

    Oakes, Kevin F.; Wood, James S.; Findlay, John T.

    1991-01-01

    Descent Best Estimate Trajectory (BET) Data were generated for the final Orbiter Experiments Flight, STS-40. This report discusses the actual development of these post-flight products: the inertial BET, the Extended BET, and the Aerodynamic BET. Summary results are also included. The inertial BET was determined based on processing Tracking and Data Relay Satellite (TDRSS) coherent Doppler data in conjunction with observations from eleven C-band stations, to include data from the Kwajalein Atoll and the usual California coastal radars, as well as data from five cinetheodolite cameras in the vicinity of the runways at EAFB. The anchor epoch utilized for the trajectory reconstruction was 53,904 Greenwich Mean Time (GMT) seconds which corresponds to an altitude at epoch of approximately 708 kft. Atmospheric data to enable development of an Extended BET for this mission were upsurped from the JSC operational post-flight BET. These data were evaluated based on Space Shuttle-derived considerations as well as model comparisons. The Aerodynamic BET includes configuration information, final mass properties, and both flight-determined and predicted aerodynamic performance estimates. The predicted data were based on the final pre-operational databook, updated to include flight determined incrementals based on an earlier ensemble of flights. Aerodynamic performance comparisons are presented and correlated versus statistical results based on twenty-two previous missions.

  2. 22 CFR 1203.735-210 - Gambling, betting, and lotteries.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Gambling, betting, and lotteries. 1203.735-210... RESPONSIBILITIES AND CONDUCT Ethical and Other Conduct and Responsibilities of Employees § 1203.735-210 Gambling, betting, and lotteries. An employee shall not participate, while on Government-owned or leased property...

  3. 18 CFR 1300.102 - Gambling, betting, and lotteries.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Gambling, betting, and lotteries. 1300.102 Section 1300.102 Conservation of Power and Water Resources TENNESSEE VALLEY AUTHORITY STANDARDS OF CONDUCT FOR EMPLOYEES OF TENNESSEE VALLEY AUTHORITY § 1300.102 Gambling, betting, and...

  4. 49 CFR 805.735-11 - Gambling, betting, and lotteries.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Gambling, betting, and lotteries. 805.735-11... TRANSPORTATION SAFETY BOARD EMPLOYEE RESPONSIBILITIES AND CONDUCT § 805.735-11 Gambling, betting, and lotteries... the Board, in any gambling activity, including the operation of a gambling device, conducting...

  5. 19 CFR 200.735-111 - Gambling, betting, and lotteries.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Gambling, betting, and lotteries. 200.735-111...-111 Gambling, betting, and lotteries. An employee shall not participate, while on Government-owned or... a gambling device, in conducting a lottery or pool, in a game for money or property, or in...

  6. High surface area aerogels for energy storage and efficiency

    Science.gov (United States)

    Maloney, Ryan Patrick

    ADAI are demonstrated in a third-generation prototypical thermoelectric generator for automotive waste heat recovery. The second chapter then details two different aerogel-based materials for electrochemical energy storage. It begins with lithium titanate aerogel, which takes advantage of the high surface area of the aerogel morphology to display a batt-cap behavior. This should allow the lithium titanate aerogel to perform at higher rates than would normally be expected for the bulk oxide material. Additionally, the flexibility of the sol-gel process is demonstrated through the incorporation of electrically conductive high-surface area exfoliated graphite nanoplatelets in the oxide. The last section describes the characterization of a LiMn2O 4 spinel coated carbon nanofoam in a non-aqueous electrolyte. The short diffusion path, high surface area and intimately wired architecture of the nanofoam allows the oxide to retain its capacity at significantly higher rates when compared with literature values for the bulk oxide. Additionally, the nanometric length scale improves cycle life, and the high surface area dramatically increases the insertion capacity by providing a higher concentration of surface defects. Taken together, it is clear that aerogels are an extremely attractive class of material for applications pertaining to energy and efficiency, and further research in this area will provide valuable solutions for pressing societal needs. (Abstract shortened by UMI.).

  7. SYNTHESIS AND CHARACTERIZATION OF γ-Mo2N WITH HIGH SURFACE AREA IN THE MIXTURES OF N2/H2%合成大比表面γ-Mo2N的新方法

    Institute of Scientific and Technical Information of China (English)

    柳云骐; 刘晨光; 阙国和

    1999-01-01

    The production of high specific surface area γ-Mo2N (up to 165 m2.g-1, passivated) by temperature programmed reaction of MoO3 with mixtures of N2 and H2 was reported. The synthetic condition of high surface area γ-Mo2N (usually, SBET>100 m2.g-1) were quite difficult and the amount of starting material MoO3 in each batch was much less than 0.5 gram. However, some synthetic conditions had been greatly improved in our experiments. The crystalline phase and specific surface area had been characterized by XRD and BET. The XRD gave some information for reaction mechanism.

  8. Surface area-dependent second harmonic generation from silver nanorods.

    Science.gov (United States)

    Ngo, Hoang Minh; Luong, Thanh Tuyen; Ledoux-Rak, Isabelle

    2016-08-17

    The nonlinear optical (NLO) properties of metallic nanoparticles strongly depend on their size and shape. Metallic gold nanorods have already been widely investigated, but other noble metals could also be used for nanorod fabrication towards applications in photonics. Here we report on the synthesis and NLO characterization of silver nanorods (AgNRs) with controllable localized surface plasmon resonance. We have implemented an original, one-step and seedless synthesis method, based on a spontaneous particle growth technique in the presence of polyvinylpyrrolidone (PVP) as a capping agent. Colloidal solutions of AgNRs with various aspect ratios (5.0; 6.3; 7.5; 8.2 and 9.7) have been obtained and characterized using Harmonic light scattering (HLS) at 1064 nm, in order to investigate their quadratic NLO properties. From HLS experiments, we demonstrate that hyperpolarizability (β) values of AgNRs display a strong dependence on their surface area.

  9. Asymptotic variance of grey-scale surface area estimators

    DEFF Research Database (Denmark)

    Svane, Anne Marie

    Grey-scale local algorithms have been suggested as a fast way of estimating surface area from grey-scale digital images. Their asymptotic mean has already been described. In this paper, the asymptotic behaviour of the variance is studied in isotropic and sufficiently smooth settings, resulting...... in a general asymptotic bound. For compact convex sets with nowhere vanishing Gaussian curvature, the asymptotics can be described more explicitly. As in the case of volume estimators, the variance is decomposed into a lattice sum and an oscillating term of at most the same magnitude....

  10. Indexing Glomerular Filtration Rate to Body Surface Area

    DEFF Research Database (Denmark)

    Redal-Baigorri, Belén; Rasmussen, Knud; Heaf, James Goya

    2014-01-01

    BACKGROUND: Kidney function is mostly expressed in terms of glomerular filtration rate (GFR). A common feature is the expression as ml/min per 1.73 m(2) , which represents the adjustment of the individual kidney function to a standard body surface area (BSA) to allow comparison between individuals....... We investigated the impact of indexing GFR to BSA in cancer patients, as this BSA indexation might affect the reported individual kidney function. METHODS: Cross-sectional study of 895 adults who had their kidney function measured with (51) chrome ethylene diamine tetraacetic acid. Mean values of BSA...

  11. High surface area graphene-supported metal chalcogenide assembly

    Science.gov (United States)

    Worsley, Marcus A.; Kuntz, Joshua; Orme, Christine A.

    2016-04-19

    A composition comprising at least one graphene-supported assembly, which comprises a three-dimensional network of graphene sheets crosslinked by covalent carbon bonds, and at least one metal chalcogenide compound disposed on said graphene sheets, wherein the chalcogen of said metal chalcogenide compound is selected from S, Se and Te. Also disclosed are methods for making and using the graphene-supported assembly, including graphene-supported MoS.sub.2. Monoliths with high surface area and conductivity can be achieved. Lower operating temperatures in some applications can be achieved. Pore size and volume can be tuned.

  12. Selective adsorption of volatile hydrocarbons and gases in high surface area chalcogels containing [ES3]3- anions (E = As, Sb)

    KAUST Repository

    Ahmed, Ejaz

    2014-11-25

    We describe the sol-gel synthesis of the two new chalcogels KFeSbS3 and NaFeAsS3, which demonstrate excellent adsorption selectivity for volatile hydrocarbons and gases. These predominantly mesoporous materials have been synthesized by reacting Fe(OAc)2 with K3SbS3 or Na3AsS3 in a formamide/water mixture at room temperature. Aerogels obtained after supercritical drying have BET surface areas of 636 m2/g and 505 m2/g for KFeSbS3 and NaFeAsS3, respectively, with pore sizes in the micro- (below 2 nm), meso- (2-50 nm), and macro- (above 50 nm) regions.

  13. High surface area graphene foams by chemical vapor deposition

    Science.gov (United States)

    Drieschner, Simon; Weber, Michael; Wohlketzetter, Jörg; Vieten, Josua; Makrygiannis, Evangelos; Blaschke, Benno M.; Morandi, Vittorio; Colombo, Luigi; Bonaccorso, Francesco; Garrido, Jose A.

    2016-12-01

    Three-dimensional (3D) graphene-based structures combine the unique physical properties of graphene with the opportunity to get high electrochemically available surface area per unit of geometric surface area. Several preparation techniques have been reported to fabricate 3D graphene-based macroscopic structures for energy storage applications such as supercapacitors. Although reaserch has been focused so far on achieving either high specific capacitance or high volumetric capacitance, much less attention has been dedicated to obtain high specific and high volumetric capacitance simultaneously. Here, we present a facile technique to fabricate graphene foams (GF) of high crystal quality with tunable pore size grown by chemical vapor deposition. We exploited porous sacrificial templates prepared by sintering nickel and copper metal powders. Tuning the particle size of the metal powders and the growth temperature allow fine control of the resulting pore size of the 3D graphene-based structures smaller than 1 μm. The as-produced 3D graphene structures provide a high volumetric electric double layer capacitance (165 mF cm-3). High specific capacitance (100 Fg-1) is obtained by lowering the number of layers down to single layer graphene. Furthermore, the small pore size increases the stability of these GFs in contrast to the ones that have been grown so far on commercial metal foams. Electrodes based on the as-prepared GFs can be a boost for the development of supercapacitors, where both low volume and mass are required.

  14. Ruthenium catalysts supported on high-surface-area zirconia for the catalytic wet oxidation of N,N-dimethyl formamide.

    Science.gov (United States)

    Sun, Guanglu; Xu, Aihua; He, Yu; Yang, Min; Du, Hongzhang; Sun, Chenglin

    2008-08-15

    Three weight percent ruthenium catalysts were prepared by incipient-wet impregnation of two different zirconium oxides, and characterized by BET, XRD and TPR. Their activity was evaluated in the catalytic wet oxidation (CWO) of N,N-dimethyl formamide (DMF) in an autoclave reactor. Due to a better dispersion, Ru catalyst supported on a high-surface-area zirconia (Ru/ZrO(2)-A) possessed higher catalytic properties. Due to over-oxidation of Ru particles, the catalytic activity of the both catalysts decreased during successive tests. The effect of oxygen partial pressure and reaction temperature on the DMF reactivity in the CWO on Ru/ZrO(2)-A was also investigated. 98.6% of DMF conversion was obtained through hydrothermal decomposition within 300 min at conditions of 200 degrees C and 2.0 MPa of nitrogen pressure. At 240 degrees C and 2.0 MPa of oxygen pressure 98.3% of DMF conversion was obtained within 150 min.

  15. Topology-guided design and syntheses of highly stable mesoporous porphyrinic zirconium metal-organic frameworks with high surface area.

    Science.gov (United States)

    Liu, Tian-Fu; Feng, Dawei; Chen, Ying-Pin; Zou, Lanfang; Bosch, Mathieu; Yuan, Shuai; Wei, Zhangwen; Fordham, Stephen; Wang, Kecheng; Zhou, Hong-Cai

    2015-01-14

    Through a topology-guided strategy, a series of Zr6-containing isoreticular porphyrinic metal-organic frameworks (MOFs), PCN-228, PCN-229, and PCN-230, with ftw-a topology were synthesized using the extended porphyrinic linkers. The bulky porphyrin ring ligand effectively prevents the network interpenetration which often appears in MOFs with increased linker length. The pore apertures of the structures range from 2.5 to 3.8 nm, and PCN-229 demonstrates the highest porosity and BET surface area among the previously reported Zr-MOFs. Additionally, by changing the relative direction of the terminal phenyl rings, this series replaces a Zr8 cluster with a smaller Zr6 cluster in a topologically identical framework. The high connectivity of the Zr6 cluster yields frameworks with enhanced stability despite high porosity and ultralarge linker. As a representative example, PCN-230, constructed with the most extended porphyrinic linker, shows excellent stability in aqueous solutions with pH values ranging from 0 to 12 and demonstrates one of the highest pH tolerances among all porphyrinic MOFs. This work not only presents a successful example of rational design of MOFs with desired topology, but also provides a strategy for construction of stable mesoporous MOFs.

  16. Recovery of high surface area mesoporous silica from waste hexafluorosilicic acid (H2SiF6) of fertilizer industry.

    Science.gov (United States)

    Sarawade, Pradip B; Kim, Jong-Kil; Hilonga, Askwar; Kim, Hee Taik

    2010-01-15

    In this article we report recovery of mesoporous silica from the waste material (hexafluorosilicic acid) of phosphate fertilizer industry. The process involves the reaction of hexafluorosilicic acid (50 ml, 24 wt% H(2)SiF(6)) and 100ml, 0.297 M Na(2)CO(3) to generate the alkaline aqueous slurry. Silica was separated from the slurry by filtration and the sodium fluoride was extracted from the aqueous solution by evaporation method. The obtained mesoporous silica was characterized by N(2) absorption/desorption (BET), thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscope (SEM), and EDS. The results confirm that the separation of silica and NaF was successful and the final products have high purity. The silica product was found to have an average pore diameter of 4.14 nm and a high surface area (up to 800 m(2)/g). The process reported in this study may significantly reduce the release of hazardous materials into the environment and it might confer economic benefits to the responsible industries.

  17. Investigation of Sea Surface Temperature (SST) anomalies over Cyprus area

    Science.gov (United States)

    Georgiou, Andreas; Akçit, Nuhcan

    2016-08-01

    The temperature of the sea surface has been identified as an important parameter of the natural environment, governing processes that occur in the upper ocean. This paper focuses on the analysis of the Sea Surface Temperature (SST) anomalies at the greater area of Cyprus. For that, SST data derived from MODerate-resolution Imaging Spectroradiometer (MODIS) instrument on board both Aqua and Terra sun synchronous satellites were used. A four year period was chosen as a first approach to address and describe this phenomenon. Geographical Information Systems (GIS) has been used as an integrated platform of analysis and presentation in addition of the support of MATLAB®. The methodology consists of five steps: (i) Collection of MODIS SST imagery, (ii) Development of the digital geo-database; (iii) Model and run the methodology in GIS as a script; (iv) Calculation of SST anomalies; and (v) Visualization of the results. The SST anomaly values have presented a symmetric distribution over the study area with an increase trend through the years of analysis. The calculated monthly and annual average SST anomalies (ASST) make more obvious this trend, with negative and positive SST changes to be distributed over the study area. In terms of seasons, the same increase trend presented during spring, summer, autumn and winter with 2013 to be the year with maximum ASST observed values. Innovative aspects comprise of straightforward integration and modeling of available tools, providing a versatile platform of analysis and semi-automation of the operation. In addition, the fine resolution maps that extracted from the analysis with a wide spatial coverage, allows the detail representation of SST and ASST respectively in the region.

  18. The impact of built-up surfaces on land surface temperatures in Italian urban areas.

    Science.gov (United States)

    Morabito, Marco; Crisci, Alfonso; Messeri, Alessandro; Orlandini, Simone; Raschi, Antonio; Maracchi, Giampiero; Munafò, Michele

    2016-05-01

    Urban areas are characterized by the very high degree of soil sealing and continuous built-up areas: Italy is one of the European countries with the highest artificial land cover rate, which causes a substantial spatial variation in the land surface temperature (LST), modifying the urban microclimate and contributing to the urban heat island effect. Nevertheless, quantitative data regarding the contribution of different densities of built-up surfaces in determining urban spatial LST changes is currently lacking in Italy. This study, which aimed to provide clear and quantitative city-specific information on annual and seasonal spatial LST modifications resulting from increased urban built-up coverage, was conducted generally throughout the whole year, and specifically in two different periods (cool/cold and warm/hot periods). Four cities (Milan, Rome, Bologna and Florence) were included in the study. The LST layer and the built-up-surface indicator were obtained via use of MODIS remote sensing data products (1km) and a very high-resolution map (5m) of built-up surfaces recently developed by the Italian National Institute for Environmental Protection and Research. The relationships between the dependent (mean daily, daytime and nighttime LST values) and independent (built-up surfaces) variables were investigated through linear regression analyses, and comprehensive built-up-surface-related LST maps were also developed. Statistically significant linear relationships (purban morphology. If implemented in the existing city plan, the urban maps of built-up-surface-related LST developed in this study might be able to support more sustainable urban land management practices by identifying the critical areas (Hot-Spots) that would benefit most from mitigation actions by local authorities, land-use decision makers, and urban planners.

  19. Estimating the surface area of birds: using the homing pigeon (Columba livia) as a model.

    Science.gov (United States)

    Perez, Cristina R; Moye, John K; Pritsos, Chris A

    2014-05-08

    Estimation of the surface area of the avian body is valuable for thermoregulation and metabolism studies as well as for assessing exposure to oil and other surface-active organic pollutants from a spill. The use of frozen carcasses for surface area estimations prevents the ability to modify the posture of the bird. The surface area of six live homing pigeons in the fully extended flight position was estimated using a noninvasive method. An equation was derived to estimate the total surface area of a pigeon based on its body weight. A pigeon's surface area in the fully extended flight position is approximately 4 times larger than the surface area of a pigeon in the perching position. The surface area of a bird is dependent on its physical position, and, therefore, the fully extended flight position exhibits the maximum area of a bird and should be considered the true surface area of a bird.

  20. Estimating the surface area of birds: using the homing pigeon (Columba livia as a model

    Directory of Open Access Journals (Sweden)

    Cristina R. Perez

    2014-05-01

    Full Text Available Estimation of the surface area of the avian body is valuable for thermoregulation and metabolism studies as well as for assessing exposure to oil and other surface-active organic pollutants from a spill. The use of frozen carcasses for surface area estimations prevents the ability to modify the posture of the bird. The surface area of six live homing pigeons in the fully extended flight position was estimated using a noninvasive method. An equation was derived to estimate the total surface area of a pigeon based on its body weight. A pigeon's surface area in the fully extended flight position is approximately 4 times larger than the surface area of a pigeon in the perching position. The surface area of a bird is dependent on its physical position, and, therefore, the fully extended flight position exhibits the maximum area of a bird and should be considered the true surface area of a bird.

  1. Fully automated algorithm for wound surface area assessment.

    Science.gov (United States)

    Deana, Alessandro Melo; de Jesus, Sérgio Henrique Costa; Sampaio, Brunna Pileggi Azevedo; Oliveira, Marcelo Tavares; Silva, Daniela Fátima Teixeira; França, Cristiane Miranda

    2013-01-01

    Worldwide, clinicians, dentists, nurses, researchers, and other health professionals need to monitor the wound healing progress and to quantify the rate of wound closure. The aim of this study is to demonstrate, step by step, a fully automated numerical method to estimate the size of the wound and the percentage damaged relative to the body surface area (BSA) in images, without the requirement for human intervention. We included the formula for BSA in rats in the algorithm. The methodology was validated in experimental wounds and human ulcers and was compared with the analysis of an experienced pathologist, with good agreement. Therefore, this algorithm is suitable for experimental wounds and burns and human ulcers, as they have a high contrast with adjacent normal skin.

  2. Error bounds for surface area estimators based on Crofton's formula

    DEFF Research Database (Denmark)

    Kiderlen, Markus; Meschenmoser, Daniel

    2009-01-01

    and the mean is approximated by a finite weighted sum S(A) of the total projections in these directions. The choice of the weights depends on the selected quadrature rule. We define an associated zonotope Z (depending only on the projection directions and the quadrature rule), and show that the relative error...... S (A)/S (A) is bounded from below by the inradius of Z and from above by the circumradius of Z. Applying a strengthened isoperimetric inequality due to Bonnesen, we show that the rectangular quadrature rule does not give the best possible error bounds for d = 2. In addition, we derive asymptotic...... behavior of the error (with increasing k) in the planar case. The paper concludes with applications to surface area estimation in design-based digital stereology where we show that the weights due to Bonnesen’s inequality are better than the usual weights based on the rectangular rule and almost optimal...

  3. High surface area ThO/sub 2/ catalyst

    Science.gov (United States)

    Colmenares, C.A.; Somorjai, G.A.; Maj, J.J.

    1983-06-21

    A ThO/sub 2/ catalyst having a high surface area of about 80 to 125m/sup 2//g is synthesized. The compound is synthesized by simultaneously mixing an aqueous solution of ThNO/sub 3/(NO/sub 3/)/sub 4/.4H/sub 2/O with an aqueous solution of Na/sub 2/CO/sub 3/.H/sub 2/O, to produce a solution and solid ThOCO/sub 3/. The solid ThOCO/sub 3/ is separated from the solution, and then calcined at a temperature of about 225 to 300/sup 0/C for about 40 to 55 hours to produce ThO/sub 2/. The ThO/sub 2/ catalyst produced includes Na present as a substitutional cation in an amount equal to about 5 to 10 at. %.

  4. Method for producing high surface area chromia materials for catalysis

    Science.gov (United States)

    Gash, Alexander E.; Satcher, Joe; Tillotson, Thomas; Hrubesh, Lawrence; Simpson, Randall

    2007-05-01

    Nanostructured chromium(III)-oxide-based materials using sol-gel processing and a synthetic route for producing such materials are disclosed herein. Monolithic aerogels and xerogels having surface areas between 150 m.sup.2/g and 520 m.sup.2/g have been produced. The synthetic method employs the use of stable and inexpensive hydrated-chromium(III) inorganic salts and common solvents such as water, ethanol, methanol, 1-propanol, t-butanol, 2-ethoxy ethanol, and ethylene glycol, DMSO, and dimethyl formamide. The synthesis involves the dissolution of the metal salt in a solvent followed by an addition of a proton scavenger, such as an epoxide, which induces gel formation in a timely manner. Both critical point (supercritical extraction) and atmospheric (low temperature evaporation) drying may be employed to produce monolithic aerogels and xerogels, respectively.

  5. A simple one step solid state synthesis of nanocrystalline ferromagnetic α-Fe{sub 2}O{sub 3} with high surface area and catalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Shete, Madhavi D.; Fernandes, J.B., E-mail: julio@unigoa.ac.in

    2015-09-01

    α-Fe{sub 2}O{sub 3} is obtained by a simple route involving solvent free solid state decomposition of ferric nitrate in presence of urea. The samples were characterized by X-ray diffraction, infra-red and UV–Vis spectral studies, TEM, BET surface area measurements and TG–DTA analysis. Magnetic measurements were done from M–H hysteresis profiles. By changing the ratio of ferric nitrate and urea, α-phase was obtained in all the synthesized samples and was accompanied with increase in ferromagnetic behavior. The samples showed good photocatalytic activity for decomposition of H{sub 2}O{sub 2} and could be correlated with surface area values. The results were interpreted in terms of activity for the heterogeneous photo-Fenton reaction. - Highlights: • α-Fe{sub 2}O{sub 3} were synthesized by a solid state method. • These oxides showed large surface area and ferromagnetic behavior. • The catalysts showed good heterogeneous photo-Fenton activity.

  6. Computing the Surface Area of Three-Dimensional Scanned Human Data

    Directory of Open Access Journals (Sweden)

    Seung-Hyun Yoon

    2016-07-01

    Full Text Available An efficient surface area evaluation method is introduced by using smooth surface reconstruction for three-dimensional scanned human body data. Surface area evaluations for various body parts are compared with the results from the traditional alginate-based method, and quite high similarity between the two results is obtained. We expect that our surface area evaluation method can be an alternative to measuring surface area by the cumbersome alginate method.

  7. High Surface Area Tungsten Carbides: Synthesis, Characterization and Catalytic Activity towards the Hydrogen Evolution Reaction in Phosphoric Acid at Elevated Temperatures

    DEFF Research Database (Denmark)

    Tomás García, Antonio Luis; Li, Qingfeng; Jensen, Jens Oluf

    2014-01-01

    Tungsten carbide powders were synthesized as a potential electrocatalyst for the hydrogen evolution reaction in phosphoric acid at elevated temperatures. With ammonium metatungstate as the precursor, two synthetic routes with and without carbon templates were investigated. Through the intermediate...... nitride route and with carbon black as template, the obtained tungsten carbide samples had higher BET area. In 100% H3PO4 at temperatures up to 185°C, the carbide powders showed superior activity towards the hydrogen evolution reaction. A deviation was found in the correlation between the BET area...

  8. Human lung volume, alveolar surface area, and capillary length

    DEFF Research Database (Denmark)

    Wiebe, B. M.; Laursen, Henning

    1995-01-01

    Cavalieri's principle, length density, morphometry, stereology, surface density, vertical sections, vertical slices......Cavalieri's principle, length density, morphometry, stereology, surface density, vertical sections, vertical slices...

  9. Extent of Stream Burial and Relationships to Watershed Area, Topography, and Impervious Surface Area

    Directory of Open Access Journals (Sweden)

    Roy E. Weitzell

    2016-11-01

    Full Text Available Stream burial—the routing of streams through culverts, pipes, and concrete lined channels, or simply paving them over—is common during urbanization, and disproportionately affects small, headwater streams. Burial undermines the physical and chemical processes governing life in streams, with consequences for water quality and quantity that may amplify from headwaters to downstream receiving waters. Knowledge of the extent of stream burial is critical for understanding cumulative impacts to stream networks, and for future decision-making allowing for urban development while protecting ecosystem function. We predicted stream burial across the urbanizing Potomac River Basin (USA for each 10-m stream segment in the basin from medium-resolution impervious cover data and training observations obtained from high-resolution aerial photography in a GIS. Results were analyzed across a range in spatial aggregation, including counties and independent cities, small watersheds, and regular spatial grids. Stream burial was generally correlated with total impervious surface area (ISA, with areas exhibiting ISA above 30% often subject to elevated ratios of stream burial. Recurring patterns in burial predictions related to catchment area and topographic slope were also detected. We discuss these results in the context of physiographic constraints on stream location and urban development, including implications for environmental management of aquatic resources.

  10. Bacterial signaling and motility: Sure bets

    Energy Technology Data Exchange (ETDEWEB)

    Zhulin, Igor B [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL)

    2008-01-01

    The IX International Conference on Bacterial Locomotion and Signal Transduction (BLAST IX) was held from 14 to 19 January 2007 in Laughlin, NV, a town in the Mojave Desert on the Nevada-Arizona border near old Route 66 and along the banks of the Colorado River. This area is a home to rattlesnakes, sagebrush, abandoned gold mines, and compulsive gamblers. What better venue could scientists possibly dream of for a professional meeting? So there they were, about 190 scientists gathered in the Aquarius Casino Resort, the largest hotel and casino in Laughlin, discussing the latest advances in the field. Aside from a brief excursion to an abandoned gold mine and a dinner cruise on the Colorado River, the scientists focused on nothing but their data and hypotheses, in spirited arguments and rebuttals, and outlined their visions and future plans in a friendly and open environment. The BLAST IX program was dense, with nearly 50 talks and over 90 posters. For that reason, this meeting report will not attempt to be comprehensive; instead it will first provide general background information on the central topics of the meeting and then highlight only a few talks that were of special interest to us and hopefully to the wider scientific community. We will also attempt to articulate some of the future directions or perspectives to the best of our abilities. The best known and understood bacterial motility mechanism is swimming powered by flagella. The rotation of bacterial flagella drives this form of bacterial movement in an aqueous environment. A bacterial flagellum consists of a helical filament attached to the cell body through a complex structure known as the hook-basal body, which drives flagellar rotation. The essential components of the basal body are the MotA-MotB motor-stator proteins bound to the cytoplasmic membrane. These stator proteins interact with proteins that comprise the supramembrane and cytoplasmic rings, which are components of the motor imbedded in the

  11. High Surface Area Ceria Nanoparticles via Hydrothermal Synthesis Experiment Design

    Directory of Open Access Journals (Sweden)

    Stanislav Kurajica

    2016-01-01

    Full Text Available Hydrothermal synthesis of CeO2 was optimized on two reactant concentrations and synthesis temperature and duration, in order to achieve material having the greatest specific surface area (SSA. Taguchi method of experimental design was employed in evaluation of the relative importance of synthesis parameters. CeO2 nanoparticles were characterized using X-ray diffraction, nitrogen adsorption-desorption isotherms, and scanning electron microscopy. Optimum conditions for obtaining particles with greater SSA were calculated according to Taguchi’s model “the-higher-the-better.” Synthesis temperature was found to be the only parameter significant for enabling nanoparticles with greater SSA. Mesoporous nanocrystalline ceria with SSA as great as 226 m2 g−1 was achieved, which is unprecedented for the hydrothermally synthesized ceria. The reason for this achievement was found in temperature dependence of the diffusion coefficient which, when low, favors nucleation yielding with fine particles, while when high it favors crystal growth and formation of one-dimensional structures. The occurrence of 1D-structure in sample exhibiting the smallest SSA was confirmed. Very fine crystallites with crystallite size as low as 5.9 nm have been obtained being roughly inverse proportional to SSA. Selected samples were tested as catalyst for soot oxidation. Catalyst morphology turned out to be decisive factor for catalytic activity.

  12. Reactive surface area in geochemical models - Lessons learned from a natural analogue

    NARCIS (Netherlands)

    Koenen, M.; Wasch, L.J.

    2013-01-01

    Many uncertainties exist in geochemical modeling. Mineral reactive surface area is one of the uncertain parameters. QEMSCAN analyses are performed on sandstone samples from a Dutch CO2 natural analogue to determine reactive surface areas. Geochemical modeling is performed using QEMSCAN surface areas

  13. THE SURFACE AREA PRESERVING MEAN CURVATURE FLOW IN QUASI-FUCHSIAN MANIFOLDS

    Institute of Scientific and Technical Information of China (English)

    Tian Daping; Li Guanghan; Wu Chuanxi

    2012-01-01

    In this paper,we consider the surface area preserving mean curvature flow in quasi-Fuchsian 3-manifolds.We show that the flow exists for all times and converges exponentially to a smooth surface of constant mean curvature with the same surface area as the initial surface.

  14. CXCR6 marks a novel subset of T-bet(lo)Eomes(hi) natural killer cells residing in human liver.

    Science.gov (United States)

    Stegmann, Kerstin A; Robertson, Francis; Hansi, Navjyot; Gill, Upkar; Pallant, Celeste; Christophides, Theodoros; Pallett, Laura J; Peppa, Dimitra; Dunn, Claire; Fusai, Giuseppe; Male, Victoria; Davidson, Brian R; Kennedy, Patrick; Maini, Mala K

    2016-05-23

    Natural killer cells (NK) are highly enriched in the human liver, where they can regulate immunity and immunopathology. We probed them for a liver-resident subset, distinct from conventional bone-marrow-derived NK. CXCR6+ NK were strikingly enriched in healthy and diseased liver compared to blood (p hi)Eomes(lo)(CXCR6-) and T-bet(lo)Eomes(hi)(CXCR6+); the latter was virtually absent in the periphery. The small circulating CXCR6+ subset was predominantly T-bet(hi)Eomes(lo), suggesting its lineage was closer to CXCR6- peripheral than CXCR6+ liver NK. These data reveal a large subset of human liver-resident T-bet(lo)Eomes(hi) NK, distinguished by their surface expression of CXCR6, adapted for hepatic tolerance and inducible anti-viral immunity.

  15. Overexpression of BetS, a Sinorhizobium meliloti high-affinity betaine transporter, in bacteroids from Medicago sativa nodules sustains nitrogen fixation during early salt stress adaptation.

    Science.gov (United States)

    Boscari, Alexandre; Van de Sype, Ghislaine; Le Rudulier, Daniel; Mandon, Karine

    2006-08-01

    Sinorhizobium meliloti possesses several betaine transporters to cope with salt stress, and BetS represents a crucial high-affinity glycine and proline betaine uptake system involved in the rapid acquisition of betaines by cells subjected to osmotic upshock. Using a transcriptional lacZ (beta-galactosidase) fusion, we showed that betS is expressed during the establishment of the symbiosis and in mature nitrogen-fixing nodules. However, neither Nod nor Fix phenotypes were impaired in a betS mutant. BetS is functional in isolated bacteroids, and its activity is strongly activated by high osmolarity. In bacteroids from a betS mutant, glycine betaine and proline betaine uptake was reduced by 85 to 65%, indicating that BetS is a major component of the overall betaine uptake activity in bacteroids in response to osmotic stress. Upon betS overexpression (strain UNA349) in free-living cells, glycine betaine transport was 2.3-fold higher than in the wild-type strain. Interestingly, the accumulation of proline betaine, the endogenous betaine synthesized by alfalfa plants, was 41% higher in UNA349 bacteroids from alfalfa plants subjected to 1 week of salinization (0.3 M NaCl) than in wild-type bacteroids. In parallel, a much better maintenance of nitrogen fixation activity was observed in 7-day-salinized plants nodulated with the overexpressing strain than in wild-type nodulated plants. Taken altogether, these results are consistent with the major role of BetS as an emergency system involved in the rapid uptake of betaines in isolated and in planta osmotically stressed bacteroids of S. meliloti.

  16. Best-bet integrated strategies for containing drug-resistant trypanosomes in cattle

    Directory of Open Access Journals (Sweden)

    Mungube Erick O

    2012-08-01

    Full Text Available Abstract Background African animal trypanosomosis is a major constraint to the rearing of productive livestock in the sub-humid Sudan-Sahel zone of West Africa where cotton is grown. Trypanosomosis is mainly controlled using trypanocidal drugs, but the effective use of drugs is threatened by the development of widespread resistance. This study tested integrated best-bet strategies for containment and/ or reversal of trypanocide resistance in villages in south-east Mali where resistance has been reported. Methods Four sentinel villages each from an intervention area (along the road from Mali to Burkina Faso and a control area (along the road from Mali to Côte d’Ivoire were selected for the study. Tsetse control was based on deltamethrin-treated stationary attractive devices and targeted cattle spraying between March 2008 and November 2009. Trypanosome-positive cattle were selectively treated with 3.5 mg/kg diminazene aceturate. Strategic helminth control using 10 mg/kg albendazole was also undertaken. During the intervention, tsetse densities along drainage lines, trypanosome infections and faecal egg counts in risk cattle (3 to 12 months of age were monitored. Results Catch reductions of 66.5 % in Glossina palpalis gambiensis and 90 % in G. tachinoides were observed in the intervention area. Trypanosome prevalence was significantly (p  0.05. Further studies are required before confirming the existence of albendazole resistant strongyles in the study area. Conclusion Integration of best-bet strategies in areas of multiple drug-resistance is expected to reduce trypanosome infection risk thus contributing to containment of trypanocidal drug resistance. Integrated best-bet strategies could therefore be considered a viable trypanosomosis control option especially in areas where multiple drug-resistance has been reported.

  17. Synthesis of high surface area, mesoporous MgO nanosheets with excellent adsorption capability for Ni(II) via a distillation treating.

    Science.gov (United States)

    Feng, Jing; Zou, Linyi; Wang, Yuting; Li, Bowen; He, Xiaofeng; Fan, Zhuangjun; Ren, Yueming; Lv, Yanzhuo; Zhang, Milin; Chen, Dan

    2015-01-15

    Hexagonal mesoporous MgO nanosheets with a side length of 250 nm and specific surface area of 181.692 m(2)/g were fabricated by a three-step process. Firstly, MgO powders were obtained by sintered Mg5(OH)2(CO3)4⋅4H2O, which was synthesized by a wet precipitation process using ammonium hydrogen carbonate as precipitants. Secondly, the above-MgO were distilled 2 h in a three-necked bottle with condenser device. Lastly, we annealed the distilled-MgO at 500-800 °C to form mesoporous MgO nanosheets. We found the pore size distribution and the thicknesses of nanosheets were determined by the distillation process in step 2 and annealed temperature in step 3. By optimizing the experimental parameters, the mesoporous dis-MgO annealed at 600 °C displayed uniform hexagonal structure with the largest pore volume (0.875 cm(3)/g) and highest BET surface area (181.692 m(2)/g), as well as the maximum adsorption capability of 1684.25 mg/g for Ni(II).

  18. Precision nanometrology of a large area microstructured metrology surface

    Institute of Scientific and Technical Information of China (English)

    WEI Gao; TAKESHI Araki; SATOSHI Kiyono

    2003-01-01

    @@ 1 Introduction The authors have been working on a newsurface encoder for detecting multi-degree-of-freedom(MDOF) translational and tilt motionsof precision stages[1]. The surface encoder con-sists of two fundamental elements: a sinusoidalmicrostructured metrology surface, which is re-ferred to as the angle grid, and a two-dimension-al (2D) slope sensor[2-3].

  19. Properties that influence the specific surface areas of carbon nanotubes and nanofibers.

    Science.gov (United States)

    Birch, M Eileen; Ruda-Eberenz, Toni A; Chai, Ming; Andrews, Ronnee; Hatfield, Randal L

    2013-11-01

    Commercially available carbon nanotubes and nanofibers were analyzed to examine possible relationships between their Brunauer-Emmett-Teller specific surface areas (SSAs) and their physical and chemical properties. Properties found to influence surface area were number of walls/diameter, impurities, and surface functionalization with hydroxyl and carboxyl groups. Characterization by electron microscopy, energy-dispersive X-ray spectrometry, thermogravimetric analysis, and elemental analysis indicates that SSA can provide insight on carbon nanomaterials properties, which can differ vastly depending on synthesis parameters and post-production treatments. In this study, how different properties may influence surface area is discussed. The materials examined have a wide range of surface areas. The measured surface areas differed from product specifications, to varying degrees, and between similar products. Findings emphasize the multiple factors that influence surface area and mark its utility in carbon nanomaterial characterization, a prerequisite to understanding their potential applications and toxicities. Implications for occupational monitoring are discussed.

  20. High-surface-area silica nanospheres (KCC-1) with a fibrous morphology

    KAUST Repository

    Polshettiwar, Vivek

    2010-08-02

    Fibrous nanosilica: A new family of high-surface-area silica nanospheres (KCC-1) have been prepared (see picture). KCC-1 features excellent physical properties, including high surface area, unprecedented fibrous surface morphology, high thermal (up to 950 °C) and hydrothermal stabilities, and high mechanical stability. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Proces og struktur i ph.d.-forløbet

    DEFF Research Database (Denmark)

    Kristensen, Nete Nørgaard; From, Unni

    Bogen giver et indblik i ph.d.-forløbet fra både faglige og personlige vinkler og udpeger problemstillinger og faldgruber - muligheder, potentialer og spændende oplevelser, der knytter sig til livets som ph.d.-stipendiat. Bogen rummer bidrag fra såvel ph.d.-studerende og seniorforskere og sætter...

  2. Construct Validity of Measures of Becker's Side Bet Theory.

    Science.gov (United States)

    Shore, Lynn M.; Tetrick, Lois E.; Shore, Ted H.; Barksdale, Kevin

    2000-01-01

    Becker's side bet theory (remaining in a job because of perceived costs of leaving) was tested using data from 327 working business students. Three factors were most consistent with the theory: bureaucratic organization, nonwork-related concerns, and adjustment to social position. Attachment to the organization was significantly linked to tangible…

  3. Microbial bet-hedging : the power of being different

    NARCIS (Netherlands)

    Grimbergen, Ard Jan; Siebring, Jeroen; Solopova, Ana; Kuipers, Oscar P

    2015-01-01

    Bet-hedging is an evolutionary theory that describes how risk spreading can increase fitness of a genotype in an unpredictably changing environment. To achieve risk spreading, maladapted phenotypes develop within isogenic populations that may be fit for a future environment. In recent years, various

  4. Rate of evolution of the specific surface area of surface snow layers.

    Science.gov (United States)

    Cabanes, Axel; Legagneux, Loïc; Dominé, Florent

    2003-02-15

    The snowpack can impact atmospheric chemistry by exchanging adsorbed or dissolved gases with the atmosphere. Modeling this impact requires the knowledge of the specific surface area (SSA) of snow and its variations with time. We have therefore measured the evolution of the SSA of eight recent surface snow layers in the Arctic and the French Alps, using CH4 adsorption at liquid nitrogen temperature (77 K). The SSA of fresh snow layers was found to decrease with time, from initial values in the range 613-1540 cm2/g to values as low as 257 cm2/g after 6 days. This is explained by snow metamorphism, which causes modifications in crystal shapes, here essentially crystal rounding and the disappearance of microstructures. A parametrization of the rate of SSA decrease is proposed. We fit the SSA decrease to an exponential law and find that the time constant alpha(exp) (day(-1)) depends on temperature according to alpha(exp) = 76.6 exp (-1708/7), with Tin kelvin. Our parametrization predicts that the SSA of a snow layer evolving at -40 degrees C will decrease by a factor of 2 after 14 days, while a similar decrease at -1 degrees C will only require 5 days. Wind was found to increase the rate of SSA decrease, but insufficient data did not allow a parametrization of this effect.

  5. Restoration of eroded surfaces in Serbian ski-areas

    Directory of Open Access Journals (Sweden)

    Ristić Ratko

    2009-01-01

    Full Text Available The environmental impacts in Serbian ski areas are very strong, leading to landscape degradation and functionality losses. Construction or improvement works cause serious destruction of topsoil and native vegetation. Some activities enhance erosion production and sediment yield: clear cuttings; trunk transport down the slope; road construction and large excavations. Also, lack of erosion control works in ski areas, especially between April and October, result in various forms of land degradation such as furrows, gullies, landslides, or debris from rock weathering. The consequences of mismanagement in ski areas are noticeable in downstream sections of river beds, causing floods and bed-load deposition. Planning and designing activities, with the application of technical and biotechnical erosion control structures, through the concept of restoration, are necessary measures in the protection of ski areas.

  6. Surface albedo measurements in Mexico City metropolitan area

    Energy Technology Data Exchange (ETDEWEB)

    Castro, T; Mar, B; Longoria, R; Ruiz Suarez, L. G [Centro de Ciencias de la Atmosfera, UNAM, Mexico, D.F. (Mexico); Morales, L [Instituto de Geografia, UNAM, Mexico, D.F. (Mexico)

    2001-04-01

    Optical and thermal properties of soils are important input data for the meteorological and photochemical modules of air quality models. As development of these models increase on spatial resolution good albedo data become more important. In this paper measurements of surface albedo of UV (295-385 nm) and visible (450-550 nm) radiation are reported for different urban and rural surfaces in the vicinity of Mexico City. It was found for the downtown zone and average albedo value of 0.05 which is in very good agreement with reported values for urban surfaces. Our albedo values measured in UV region for grey cement and green grass are of 0.10 and 0.009, respectively, and quite similar to those found at the literature of 0.11 and 0.008 for those type of surfaces. [Spanish] Las propiedades opticas y termicas de suelos son datos importantes para los modulos meteorologicos y fotoquimicos de los modelos de calidad del aire. Conforme aumenta la resolucion espacial del modelo se vuelve mas importante contar con buenos datos de albedo. En este articulo se presentan mediciones de albedo superficial de radiacion Ultravioleta (295-385 nm) y visible (450-550 nm) para diferentes superficies urbanas. Los valores medidos de albedo en la region UV para cemento gris y pasto verde son de 0.10 y 0.009, respectivamente, y son muy similares a los reportados en la literatura, 0.11 y 0.008 para este tipo de superficies.

  7. Effects of CO/sub 2/ enrichment on internal leaf surface area in soybeans

    Energy Technology Data Exchange (ETDEWEB)

    Leadley, P.W.; Reynolds, J.A.; Thomas, J.F.; Reynolds, J.F.

    1987-06-01

    Internal cell surface areas were measured on fully expanded leaves of soybean seedlings that had been continuously exposed to 348 or 645 ppm CO/sub 2/ environments. Plants grown in the high CO/sub 2/ treatment had thicker leaves but less palisade cell surface area per unit of leaf area. Surface area of the mesophyll per unit leaf area was unaffected by CO/sub 2/. The potential ramifications of these CO/sub 2/-induced changes in leaf anatomy on photosynthesis and water-use efficiency are explored.

  8. Snow specific surface area simulation using the one-layer snow model in the Canadian LAnd Surface Scheme (CLASS)

    OpenAIRE

    2013-01-01

    Snow grain size is a key parameter for modeling microwave snow emission properties and the surface energy balance because of its influence on the snow albedo, thermal conductivity and diffusivity. A model of the specific surface area (SSA) of snow was implemented in the one-layer snow model in the Canadian LAnd Surface Scheme (CLASS) version 3.4. This offline multilayer model (CLASS-SSA) simulates the decrease of SSA based on snow age, snow temperature and t...

  9. BLM National Surface Management Agency: Area Polygons, Withdrawal Area Polygons, and Special Public Purpose Withdrawal Area Polygons

    Data.gov (United States)

    Federal Geographic Data Committee — The SMA implementation is comprised of one feature dataset, with several polygon feature classes, rather than a single feature class. SurfaceManagementAgency: The...

  10. The specific surface area of methane hydrate formed in different conditions and manners

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The specific surface area of methane hydrates, formed both in the presence and absence of sodium dodecyl sulfate (SDS) and processed in different manners (stirring, compacting, holding the hydrates at the formation conditions for different periods of time, cooling the hydrates for different periods of time before depressurizing them), was measured under atmospheric pressure and temperatures below ice point. It was found that the specific surface area of hydrate increased with the decreasing temperature. The methane hydrate in the presence of SDS was shown to be of bigger specific surface areas than pure methane hydrates. The experimental results further demonstrated that the manners of forming and processing hydrates affected the specific surface area of hydrate samples. Stirring or compacting made the hydrate become finer and led to a bigger specific surface area.

  11. A method for increasing the surface area of perovskite-type oxides

    Indian Academy of Sciences (India)

    S Banerjee; V R Choudhary

    2000-10-01

    A method based on hydrothermal treatments is described for increasing the surface area of sintered ABO3-type perovskite oxides. Influence of hydrothermal treatments, such as water treatment at 125-300°C under autogeneous pressure and steam treatment at 350-800°C, to low surface area (or sintered) LaCoO3 and LaMnO3 perovskite oxides on their surface properties (viz. surface area, crystal size and morphology and surface La/(Co or Mn) ratio) and also catalytic activity in complete combustion of methane at different temperatures (450-600°C) has been thoroughly investigated. The hydrothermal treatments result in the activation of the perovskite oxides by increasing their surface area very markedly.

  12. Long-term studies on the effects of nonvolatile organic compounds on porous media surface areas.

    Science.gov (United States)

    Khachikian, Crist S; Harmon, Thomas C

    2002-01-01

    This paper investigates the long-term behavior of porous media contaminated by nonvolatile organic compounds (NVOC) in terms of specific interfacial surface area. Specifically, a natural sand, Moffett sand (MS), was contaminated with naphthalene and the surface area was measured repeatedly over time using nitrogen adsorption-desorption techniques. A field-contaminated sand affected by lamp-black material (LB) from former manufactured gas plant operations was also studied. Lampblack is a carbonaceous skeleton containing polycyclic aromatic hydrocarbons (PAHs) and other hydrocarbons. It is hypothesized that soils contaminated by these types of chemicals will exhibit significantly less surface area than their clean counterparts. The surface areas for the contaminated MS samples increased toward their clean-MS values during the 700-h aging period, but achieved the clean values only after pentane extraction or heating at 60 degrees C. Heating at 50 degrees C failed to achieve a similar recovery of the clean-MS surface area value. Nonspecific mass loss tracked the increase in surface area as indirect evidence that naphthalene loss was the cause of the surface area increase. For the LB samples, aging at 100 degrees C produced a slight decrease in surface area and mass while aging at 250 degrees C caused the surface area to increase roughly threefold while the mass decreased by approximately 1%. These results suggest that, under moderate heating and over the time scale of this investigation, there is a redistribution of the complex contaminant mixture on the solid matrix. Greater temperatures remove mass more efficiently and therefore exhibited the surface area increase expected in this experiment.

  13. Surface and subsurface conditions in permafrost areas - a literature review

    Energy Technology Data Exchange (ETDEWEB)

    Vidstrand, Patrik [Bergab, Goeteborg (Sweden)

    2003-02-01

    This report contains a summary of some of the information within existing technical and scientific literature on permafrost. Permafrost is viewed as one of the future climate driven process domains that may exist in Scandinavia, and that may give rise to significantly different surface and subsurface conditions than the present. Except for changes in the biosphere, permafrost may impact hydraulic, mechanical, and chemical subsurface processes and conditions. Permafrost and its influences on the subsurface conditions are thus of interest for the performance and safety assessments of deep geological waste repositories. The definition of permafrost is 'ground that stays at or below 0 deg C for at least two consecutive years'. Permafrost will effect the geological subsurface to some depth. How deep the permafrost may grow is a function of the heat balance, thermal conditions at the surface and within the ground, and the geothermal heat flux from the Earth's inner parts. The main chapters of the report summaries the knowledge on permafrost evolution, occurrence and distribution, and extracts information concerning hydrology and mechanical and chemical impacts due to permafrost related conditions. The results of a literature review are always dependent on the available literature. Concerning permafrost there is some literature available from investigations in the field of long-term repositories and some from mining industries. However, reports of these investigations are few and the bulk of permafrost literature comes from the science departments concerned with surficial processes (e.g. geomorphology, hydrology, agriculture, etc) and from engineering concerns, such as foundation of constructions and pipeline design. This focus within the permafrost research inevitably yields a biased but also an abundant amount of information on localised surficial processes and a limited amount on regional and deep permafrost characteristics. Possible conclusions are that

  14. Adults Learning Mathematics: What We Should Know about Betting and Bookkeeping?

    Science.gov (United States)

    Maasz, Juergen; Siller, Hans-Stefan

    2010-01-01

    A lot of people risk money with bets on sport events or other events. Bookkeepers that offer such bets earn a lot of money. We are making a proposal (more exactly: a concept for a part of a basic mathematics course) for learning mathematics behind the screen (internet bets are very popular). Learners should organize a "sports event"…

  15. Three-year changes of surface albedo of degraded grassland and cropland surfaces in a semiarid area

    Institute of Scientific and Technical Information of China (English)

    LIU HuiZhi; TU Gang; DONG WenJie

    2008-01-01

    Diurnal, seasonal and interannual variations of surface albedo of degraded grassland and cropland surfaces at a semiarid area of Tognyu have been investigated based on the continuous three years observational data from 2003 to 2005. The changes of surface albedo with solar elevation angle and soil moisture have been discussed also. It has been found that surface albedo has almost the same diurnal and seasonal variations on degraded grassland and cropland surfaces in the semiarid area, while sur-face albedo is large in winter and small in summer. The diurnal variation of the surface albedo has re-lationship with the weather condition. The diurnal cycle of the surface albedo likes the "U" shape curve in sunny day, while it is low-high after the rain, and high-low after the snow. The surface albedo has large variation in cloudy day, while it has no any variation in overcast day. The large difference of the surface albedo can be 0.04 in winter between two land surfaces, because the snow has large effects on the surface albedo in winter. The rainfall is an important factor in summer on the surface albedo, while the difference of the surface albedo is 0.01 only between two land surfaces. The differences of the surface aibedo can also be 0.04 in autumn due to vegetation growing. The seasonal-average surface albeo from 2003-2005 is 0.25, 0.22, 0.24, 0.32 respectively in spring, summer, autumn and winter on the degraded grassland surface, while it is 0.25, 0.21,0.22, 0.33 respectively in spring, summer, autumn and winter on the cropland surface. The surface albedo becomes smaller with the increase of solar elevation angle. When the solar elevation angle is greater than 40°, the surface albedo changes very little and tends to be a constant. The surface albedo has negative exponent functions with soil moisture in the growing season.

  16. Influence of surface morphology and surface area on release behavior of hydrogen isotopes in LiNbO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Deqiong, E-mail: zhudeqiong@snu.ac.kr [Department of Nuclear Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Oda, Takuji [Department of Nuclear Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Tanaka, Satoru [Department of Nuclear Engineering and Management, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 Japan (Japan)

    2014-11-15

    Surface processes have profound influence on tritium release behavior in ceramic breeder materials. In this paper, the release behavior of hydrogen isotopes in LiNbO{sub 3} is studied by thermal desorption spectroscopy (TDS) with focusing on the influence of the surface morphology and surface area. It is found that the amount of surface hydroxyl groups is proportional to the specific surface area and can be decreased by smoothing the surface roughness through heating pretreatment at high temperatures. The isotope exchange reaction between the surface hydroxyl groups and water molecules residue in the system is discussed and turns out to proceed fast. The release behavior of hydrogen isotopes in LiNbO{sub 3} is compared with that in Li{sub 2}TiO{sub 3} studied in our previous work. It reveals that LiNbO{sub 3} and Li{sub 2}TiO{sub 3} have similar surface environment and similar concentration of surface hydroxyl groups with the level of 10{sup 20} m{sup −2}. The formation mechanism of hydroxyl groups on the surface is discussed and a model to explain the experimental observations is proposed.

  17. Structural aspects and porosity features of nano-size high surface area alumina-silica mixed oxide catalyst generated through hybrid sol-gel route

    Energy Technology Data Exchange (ETDEWEB)

    Padmaja, P. [Ceramic Technology Division, Regional Research Laboratory (CSIR), Trivandrum 695019, Kerala (India)]. E-mail: padmavasudev@yahoo.com; Warrier, K.G.K. [Ceramic Technology Division, Regional Research Laboratory (CSIR), Trivandrum 695019, Kerala (India)]. E-mail: kgk_warrier@yahoo.com; Padmanabhan, M. [School of Chemical Sciences, Mahatma Gandhi University, Kottayam 686560, Kerala (India); Wunderlich, W. [Graduate School of Engineering, Nagoya Institute of Technology, 466-8555 Nagoya (Japan); Berry, F.J. [Department of Chemistry, Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Mortimer, M. [Department of Chemistry, Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Creamer, N.J. [Department of Chemistry, Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom)

    2006-01-10

    Alumina-silica mixed oxide nano-catalyst materials with compositions 83.6 wt.% Al{sub 2}O{sub 3}-16.4 wt.% SiO{sub 2} (3Al{sub 2}O{sub 3}.1SiO{sub 2}), 71.82 wt.% Al{sub 2}O{sub 3}-28.18 wt.% SiO{sub 2} (3Al{sub 2}O{sub 3}.2SiO{sub 2}), 62.84 wt.% Al{sub 2}O{sub 3}-37.16 wt.% SiO{sub 2} (3Al{sub 2}O{sub 3}.3SiO{sub 2}) and 56.03 wt.% Al{sub 2}O{sub 3}-43.97 wt.% SiO{sub 2} (3Al{sub 2}O{sub 3}.4SiO{sub 2}) have been prepared by a hybrid sol-gel technique using boehmite as the precursor for alumina and tetraethoxysilane as that for silica. The bonding characteristics and coordination features around Al and Si in the mixed oxide catalysts have been studied using FTIR and {sup 27}Al MAS NMR after calcination at 400 deg. C which is the temperature region where cross-condensation is seen to take place. A high BET specific surface area of 287 m{sup 2} g{sup -1} is obtained for 3Al{sub 2}O{sub 3}.1SiO{sub 2} mixed oxide composition. The porosity features are further established by BET adsorption isotherms and pore size distribution analysis. The temperature-programmed desorption studies showed more surface active sites for the silica-rich composition, suggesting enhanced catalytic potential. The TEM features of the mixed oxides showed a homogeneous distribution of alumina and silica phases with particle sizes in the nano-range. The low silica-containing mixed oxide showed a needle-like morphology with a high aspect ratio of 1:50 and {approx}10 nm particle size while the silica-rich composition had particle size in a wide range ({approx}20-75 nm)

  18. Formation and characterization of high surface area thermally stabilized titania/silica composite materials via hydrolysis of titanium(IV) tetra-isopropoxide in sols of spherical silica particles.

    Science.gov (United States)

    Khalil, Kamal M S; Elsamahy, Ahmed A; Elanany, Mohamed S

    2002-05-15

    A direct synthetic route leading to titania particles dispersed on nonporous spherical silica particles has been investigated; 5, 10, and 20% (w/w) titania/silica sols mixtures were achieved via hydrolyzation of titanium tetra-isopropxide solution in the mother liquor of a freshly prepared sol of spherical silica particles (Stöber particles). Titania/silica materials were produced by subsequent drying and calcination of the xerogels so obtained for 3 h at 400 and 600 degrees C. The materials were investigated by means of thermal analyses (TGA and DSC), FT-IR, N(2) gas adsorption-desorption, powder X-ray diffraction (XRD), and transmission electron microscopy (TEM). In spite of the low surface area (13.1 m(2)/g) of the pure spherical silica particles calcined at 400 degrees C, high surface area and mesoporous texture titania/silica materials were obtained (e.g., S(BET) ca. 293 m(2)/g for the 10% titania/silica calcined at 400 degrees C). Moreover, the materials were shown to be amorphous toward XRD up to 600 degrees C, while reasonable surface areas were preserved. It has been concluded that dispersion of titania particles onto the surface of the nonporous spherical silica particles increase their roughness, therefore leading to composite materials of less firm packing and mesoporosity.

  19. Changes in the Surface Area of Glaciers in Northern Eurasia

    Science.gov (United States)

    Khromova, T.; Nosenko, G.

    2012-12-01

    Glaciers are widely recognized as key indicators of climate change. Recent evidence suggests an acceleration of glacier mass loss in several key mountain regions. Glacier recession implies the landscape changes in the glacial zone, origin of new lakes and activation of natural disaster processes, catastrophic mudflows, ice avalanches, outburst floods, and etc. The presence of glaciers in itself threats to human life, economic activity and growing infrastructure. Economical and recreational human activity in mountain regions requires relevant information on snow and ice objects. Absence or inadequacy of such information results in financial and human losses. A more comprehensive evaluation of glacier changes is imperative to assess ice contributions to global sea level rise and the future of water resources from glacial basins. One of the urgent steps is a full inventory of all ice bodies, their volume and changes The first estimation of glaciers state and glaciers distribution in the big part of Northern Eurasia has been done in the USSR Glacier Inventory published in 1966 -1980 as a part of IHD activity. The Inventory is based on topographic maps and air photos and reflects the status of the glaciers in 1957-1970y. There is information about 23796 glaciers with area of 78222.3 km2 in the Inventory. It covers 23 glacier systems on Northern Eurasia. In the 80th the USSR Glacier Inventory has been transformed in the digital form as a part of the World Glacier Inventory. Recent satellite data provide a unique opportunity to look again at these glaciers and to evaluate changes in glacier extent for the second part of XX century. In the paper we report about 15 000 glaciers outlines for Caucasus, Pamir, Tien-Shan, Altai, Syntar-Khayata, Cherskogo Range, Kamchatka and Russian Arctic which have been derived from ASTER and Landsat imagery and could be used for glacier changes evaluation. The results show that glaciers are retreating in all these regions. There is, however

  20. Estimating the surface area of non-convex particles from central planar sections

    DEFF Research Database (Denmark)

    Thórisdóttir, Ólöf; H.Rafati, Ali; Kiderlen, Markus

    . In this section plane a modification of the area tangent count method is used. The Morse type estimator generalizes Cruz-Orive's pivotal estimator for convex objects to non-convex objects. The advantages of the Morse type estimator over existing local surface area estimators are illustrated in a simulation study......In this paper, we present a new surface area estimator in local stereology. This new estimator is called the 'Morse type surface area estimator' and is obtained using a two-stage sampling procedure. First a plane section through a fixed reference point of a three-dimensional structure is taken....... The Morse type estimator is well suited for computer assisted confocal microscopy and we demonstrate its practicability in a biological application: the surface area estimation of the nuclei of giant-cell glioblastoma from microscopy images. We also present an interactive software that allows the user...

  1. Assessment of heavy metal levels in surface sediments of estuaries and adjacent coastal areas in China

    Science.gov (United States)

    Liu, Xianbin; Li, Deliang; Song, Guisheng

    2017-03-01

    This article investigates the variations of contamination levels of heavy metals such as copper, lead, chromium, cadmium, zinc, arsenic, and mercury over time in surface sediments of the Changjiang River Estuary (CRE), Yellow River Estuary (YRE), Pearl River Estuary (PRE), and their adjacent coastal areas in China. The contamination factor (CF), pollution load index (PLI), and geoaccumulation index ( I geo) are used to evaluate the quality of the surface sediments in the study areas. The results showed that the CRE, YRE, and their adjacent coastal areas were at a low risk of contamination in terms of heavy metals, while the PRE and its adjacent coastal area were at a moderate level. By comparison, the concentrations of heavy metals in the surface sediments of the YRE and its adjacent coastal area were relatively lower than those in the CRE, PRE, and their adjacent coastal areas.

  2. Relationship between Mineral Soil Surface Area and the Biological Degradation of Biosolids Added to Soil

    Directory of Open Access Journals (Sweden)

    Dongqi Wen

    2015-12-01

    Full Text Available Geochemical and biological processes that operate in the soil matrix and on the soil surface are important to the degradation of biosolids in soil. Due to the large surface area of soils it is assumed that the microbial ecology is associated with mineral soil surface area. The total mineral surface areas were determined for soils from eight different fields selected from a long term study (1972–2006 of annual biosolids application to 41 fields in central Illinois varying in size from 3.6 to 66 ha. The surface areas for the soils varied from 1 to 9 m2/g of soil. The biological degradation rates for the eight soils were determined using a biological degradation rate model (DRM and varied from 0.02 to 0.20/year−1. Regression analysis revealed that the degradation rate was positively associated with mineral soil surface area (1 m2/g produces 0.018 year−1 increase in the degradation rate. The annual soil sequestration rate was calculated to increase from 1% to 6% when the soil total surface area increased from 1 to 9 m2/g of soil. Therefore, land application of biosolids is an effective way to enhance carbon sequestration in soils and reduce greenhouse gas emissions.

  3. Performance modeling of a wearable brain PET (BET) camera

    Science.gov (United States)

    Schmidtlein, C. R.; Turner, J. N.; Thompson, M. O.; Mandal, K. C.; Häggström, I.; Zhang, J.; Humm, J. L.; Feiglin, D. H.; Krol, A.

    2016-03-01

    Purpose: To explore, by means of analytical and Monte Carlo modeling, performance of a novel lightweight and low-cost wearable helmet-shaped Brain PET (BET) camera based on thin-film digital Geiger Avalanche Photo Diode (dGAPD) with LSO and LaBr3 scintillators for imaging in vivo human brain processes for freely moving and acting subjects responding to various stimuli in any environment. Methods: We performed analytical and Monte Carlo modeling PET performance of a spherical cap BET device and cylindrical brain PET (CYL) device, both with 25 cm diameter and the same total mass of LSO scintillator. Total mass of LSO in both the BET and CYL systems is about 32 kg for a 25 mm thick scintillator, and 13 kg for 10 mm thick scintillator (assuming an LSO density of 7.3 g/ml). We also investigated a similar system using an LaBr3 scintillator corresponding to 22 kg and 9 kg for the 25 mm and 10 mm thick systems (assuming an LaBr3 density of 5.08 g/ml). In addition, we considered a clinical whole body (WB) LSO PET/CT scanner with 82 cm ring diameter and 15.8 cm axial length to represent a reference system. BET consisted of distributed Autonomous Detector Arrays (ADAs) integrated into Intelligent Autonomous Detector Blocks (IADBs). The ADA comprised of an array of small LYSO scintillator volumes (voxels with base a×a: 1.0 50% better noise equivalent count (NEC) performance relative to the CYL geometry, and >1100% better performance than a WB geometry for 25 mm thick LSO and LaBr3. For 10 mm thick LaBr3 equivalent mass systems LSO (7 mm thick) performed ~40% higher NEC than LaBr3. Analytic and Monte Carlo simulations also showed that 1×1×3 mm scintillator crystals can achieve ~1.2 mm FWHM spatial resolution. Conclusions: This study shows that a spherical cap brain PET system can provide improved NEC while preserving spatial resolution when compared to an equivalent dedicated cylindrical PET brain camera and shows greatly improved PET performance relative to a conventional

  4. Analysis of particle size reduction on overall surface area and enzymatic hydrolysis yield of corn stover.

    Science.gov (United States)

    Li, Hanjie; Ye, Chenlin; Liu, Ke; Gu, Hanqi; Du, Weitao; Bao, Jie

    2015-01-01

    Particle size of lignocellulose materials is an important factor for enzymatic hydrolysis efficiency. In this study, corn stover was milled and sieved into different size fractions from 1.42, 0.69, 0.34, to 0.21 mm, and the corresponding enzymatic hydrolysis yields were 24.69, 23.96, 25.34, and 26.97 %, respectively. The results indicate that the hydrolysis yield is approximately constant with changing corn stover particle sizes in the experimental range. The overall surface area and the inner pore size measurement show that the overall specific surface area was less than 2 % with the half reduction of particle size due to the greater inner pore surface area. The scanning electron microscope photographs gave direct evidence of the much greater inner pore surface area of corn stover particles. This result provided a reference when a proper size reduction of lignocellulose materials is considered in biorefining operations.

  5. Synthesis and characterization of large specific surface area nanostructured amorphous silica materials.

    Science.gov (United States)

    Marquez-Linares, Francisco; Roque-Malherbe, Rolando M A

    2006-04-01

    Large specific surface area materials attract wide attention because of their applications in adsorption, catalysis, and nanotechnology. In the present study, we describe the synthesis and characterization of nanostructured amorphous silica materials. These materials were obtained by means of a modification of the Stobe-Fink-Bohn (SFB) method. The morphology and essential features of the synthesized materials have been studied using an automated surface area and pore size analyzer and scanning electron microscopy. The existence of a micro/mesoporous structure in the obtained materials has been established. It was also found that the obtained particle packing materials show large specific surface area up to 1,600 m2/g. (To our best knowledge, there is no any reported amorphous silica material with such a higher specific surface area.) The obtained materials could be useful in the manufacture of adsorbents, catalyst supports, and other nanotechnological applications.

  6. Evolution of Specific Surface Area Inside Glass Immersed in Beishan Groundwater

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>The surface area of the fissure inside the glass block is an important parameter influencing the long term behavior of high-level radioactive waste glass in the aqueous media during the deep geological

  7. Method of forming macro-structured high surface area transparent conductive oxide electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Forman, Arnold J.; Chen, Zhebo; Jaramillo, Thomas F.

    2016-01-05

    A method of forming a high surface area transparent conducting electrode is provided that includes depositing a transparent conducting thin film on a conductive substrate, where the transparent conducting thin film includes transparent conductive particles and a solution-based transparent conducting adhesive layer which serves to coat and bind together the transparent conducting particles, and heat treating the transparent conducting adhesion layer on the conductive substrate, where an increased surface area transparent conducting electrode is formed.

  8. Target Surface Area Effects on Hot Electron Dynamics from High Intensity Laser-Plasma Interactions

    Science.gov (United States)

    2016-08-19

    New J. Phys. 18 (2016) 063020 doi:10.1088/1367-2630/18/6/063020 PAPER Target surface area effects on hot electron dynamics from high intensity laser ...Science, University ofMichigan, AnnArbor,MI 48109-2099, USA E-mail: czulick@umich.edu Keywords: laser -plasma,mass-limited, fast electrons, sheath...field Abstract Reduced surface area targets were studied using an ultra-high intensity femtosecond laser in order to determine the effect of electron

  9. High-surface-area, dual-function oxygen electrocatalysts for space power applications

    Science.gov (United States)

    Ham, David O.; Moniz, Gary; Taylor, E. Jennings

    1987-01-01

    The processes of hydration/dehydration and carbonation/decarbonation are investigated as an approach to provide higher surface area mixed metal oxides that are more active electrochemically. These materials are candidates for use as electrocatalysts and electrocatalyst supports for alkaline electrolyzers and fuel cells. For the case of the perovskite, LaCoO3 , higher surface areas were achieved with no change in structure and a more active oxygen electrocatalyst.

  10. Interdependence between body surface area and ultraviolet B dose in vitamin D production

    DEFF Research Database (Denmark)

    Bogh, M K B; Schmedes, Anne; Philipsen, P A;

    2011-01-01

    Ultraviolet (UV) B radiation increases serum vitamin D level expressed as 25-hydroxyvitamin-D(3) [25(OH)D], but the relationship to body surface area and UVB dose needs investigation.......Ultraviolet (UV) B radiation increases serum vitamin D level expressed as 25-hydroxyvitamin-D(3) [25(OH)D], but the relationship to body surface area and UVB dose needs investigation....

  11. Estimation of surface area concentration of workplace incidental nanoparticles based on number and mass concentrations

    Science.gov (United States)

    Park, J. Y.; Ramachandran, G.; Raynor, P. C.; Kim, S. W.

    2011-10-01

    Surface area was estimated by three different methods using number and/or mass concentrations obtained from either two or three instruments that are commonly used in the field. The estimated surface area concentrations were compared with reference surface area concentrations (SAREF) calculated from the particle size distributions obtained from a scanning mobility particle sizer and an optical particle counter (OPC). The first estimation method (SAPSD) used particle size distribution measured by a condensation particle counter (CPC) and an OPC. The second method (SAINV1) used an inversion routine based on PM1.0, PM2.5, and number concentrations to reconstruct assumed lognormal size distributions by minimizing the difference between measurements and calculated values. The third method (SAINV2) utilized a simpler inversion method that used PM1.0 and number concentrations to construct a lognormal size distribution with an assumed value of geometric standard deviation. All estimated surface area concentrations were calculated from the reconstructed size distributions. These methods were evaluated using particle measurements obtained in a restaurant, an aluminum die-casting factory, and a diesel engine laboratory. SAPSD was 0.7-1.8 times higher and SAINV1 and SAINV2 were 2.2-8 times higher than SAREF in the restaurant and diesel engine laboratory. In the die casting facility, all estimated surface area concentrations were lower than SAREF. However, the estimated surface area concentration using all three methods had qualitatively similar exposure trends and rankings to those using SAREF within a workplace. This study suggests that surface area concentration estimation based on particle size distribution (SAPSD) is a more accurate and convenient method to estimate surface area concentrations than estimation methods using inversion routines and may be feasible to use for classifying exposure groups and identifying exposure trends.

  12. Probing large area surface plasmon interference in thin metal films using photon scanning tunneling microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Passian, A.; Wig, A.; Lereu, A.L.; Evans, P.G.; Meriaudeau, F.; Thundat, T.; Ferrell, T.L

    2004-08-15

    The interference of surface plasmons can provide important information regarding the surface features of the hosting thin metal film. We present an investigation of the interference of optically excited surface plasmons in the Kretschmann configuration in the visible spectrum. Large area surface plasmon interference regions are generated at several wavelengths and imaged with the photon scanning tunneling microscope. Furthermore, we discuss the non-retarded dispersion relations for the surface plasmons in the probe-metal system modeled as confocal hyperboloids of revolution in the spheroidal coordinate systems.

  13. PyBetVH: A Python tool for probabilistic volcanic hazard assessment and for generation of Bayesian hazard curves and maps

    Science.gov (United States)

    Tonini, Roberto; Sandri, Laura; Anne Thompson, Mary

    2015-06-01

    PyBetVH is a completely new, free, open-source and cross-platform software implementation of the Bayesian Event Tree for Volcanic Hazard (BET_VH), a tool for estimating the probability of any magmatic hazardous phenomenon occurring in a selected time frame, accounting for all the uncertainties. New capabilities of this implementation include the ability to calculate hazard curves which describe the distribution of the exceedance probability as a function of intensity (e.g., tephra load) on a grid of points covering the target area. The computed hazard curves are (i) absolute (accounting for the probability of eruption in a given time frame, and for all the possible vent locations and eruptive sizes) and (ii) Bayesian (computed at different percentiles, in order to quantify the epistemic uncertainty). Such curves allow representation of the full information contained in the probabilistic volcanic hazard assessment (PVHA) and are well suited to become a main input to quantitative risk analyses. PyBetVH allows for interactive visualization of both the computed hazard curves, and the corresponding Bayesian hazard/probability maps. PyBetVH is designed to minimize the efforts of end users, making PVHA results accessible to people who may be less experienced in probabilistic methodologies, e.g. decision makers. The broad compatibility of Python language has also allowed PyBetVH to be installed on the VHub cyber-infrastructure, where it can be run online or downloaded at no cost. PyBetVH can be used to assess any type of magmatic hazard from any volcano. Here we illustrate how to perform a PVHA through PyBetVH using the example of analyzing tephra fallout from the Okataina Volcanic Centre (OVC), New Zealand, and highlight the range of outputs that the tool can generate.

  14. Features of wind field over the sea surface in the coastal area

    Science.gov (United States)

    Monzikova, A. K.; Kudryavtsev, V. N.; Myasoedov, A. G.; Chapron, B.; Zilitinkevich, S. S.

    2017-01-01

    In this paper we analyze SAR wind field features, in particular the effects of wind shadowing. These effects represent the dynamics of the internal atmospheric boundary layer, which is formed due to the transition of the air flow arriving from the rough land surface to the "smooth" water surface. In the wind-shadowed area, the flow accelerates, and a surface wind stress increases with fetch. The width of the shadow depends not only on the wind speed and atmospheric boundary layer stratification, but also on geographic features such as windflow multiple transformations over the complex surface land-Lake Chudskoe-land-Gulf of Finland. Measurements showed that, in the area of wind acceleration, the surface stress normalized by an equilibrium value (far from the coast) is a universal function of dimensionless fetch Xf/G. Surface wind stress reaches an equilibrium value at Xf/G ≈ 0.4, which is the scale of the planetary-boundary-layer relaxation.

  15. Elastic deformation behaviour of Palaeogene clay from Fehmarn Belt area

    DEFF Research Database (Denmark)

    Awadalkarim, Ahmed; Foged, Niels Nielsen; Fabricius, Ida Lykke

    2014-01-01

    clays. Elastic wave velocities are influenced by the elastic stiffness and the density of a material. We used geotechnical and elastic wave velocity data to model the elasticity and then to relate it to mineralogy and BET surface area. We measured the mineralogy, BET surface area, bulk density, porosity...... and of high to very high plasticity. Comprehensive and advanced laboratory tests were done by Fugro-McClelland (in Netherlands) and by Danish Geotechnical Institute (in Denmark) on Palaeogene clays. Some of their data are included in this study. Ten Palaeogene clay samples were selected and used in this study......, water content and saturation, elastic wave velocities, electrical resistivity and strain caused by mechanical loading. They were used together to interpret the geotechnical data. We aimed to see which physical property is a main controlling factor for the elasticity of the studied Palaeogene clay...

  16. Models of bedrock surface and overburden thickness over Olkiluoto island and nearby sea area

    Energy Technology Data Exchange (ETDEWEB)

    Moenkkoenen, H. [WSP Finland Oy, Helsinki (Finland)

    2012-04-15

    In this report, a model of bedrock surface and a model of overburden thickness over the Olkiluoto Island and the nearby sea area are presented. Also in purpose to produce material for biosphere and radionuclide transport modelling, stratigraphy models of different sediment layers were created at two priority areas north and south of the Olkiluoto Island. The work concentrated on the collection and description of available data of bedrock surface and overburden thickness. Because the information on the bedrock surface and overburden is collected from different sources and is based on a number of types of data the quality and applicability of data sets varies. Consequently also the reliability in different parts of the models varies. Input data for the bedrock surface and overburden thickness models include 2928 single points and additional outcrops observations (611 polygons) in the modelled area. In addition, the input data include 173 seismic refraction lines (6534 points) and acousticseismic sounding lines (26655 points from which 13721 points are located in model area) in the Olkiluoto offshore area. The average elevation of bedrock surface in area is 2.1 metres above the sea level. The average thickness of overburden is 2.5 metres varying typically between 2 - 4 metres. Thickest overburden covers (approximately 16 metres) of terrestrial area are located at the western end of the Olkiluoto Island and in sea basin south of the island. (orig.)

  17. Greenland surface mass-balance observations from the ice-sheet ablation area and local glaciers

    NARCIS (Netherlands)

    Machguth, Horst; Thomsen, Henrik H.; Weidick, Anker; Ahlstrøm, Andreas P.; Abermann, Jakob; Andersen, Morten L.; Andersen, Signe B.; Bjørk, Anders A.; Box, Jason E.; Braithwaite, Roger J.; Bøggild, Carl E.; Citterio, Michele; Clement, Poul; Colgan, William; Fausto, Robert S.; Gleie, Karin; Gubler, Stefanie; Hasholt, Bent; Hynek, Bernhard; Knudsen, Niels T.; Larsen, Signe H.; Mernild, Sebastian H.; Oerlemans, Johannes; Oerter, Hans; Olesen, Ole B.; Smeets, C. J P Paul; Steffen, Konrad; Stober, Manfred; Sugiyama, Shin; Van As, Dirk; Van Den Broeke, Michiel R.; Van De Wal, Roderik S W

    2016-01-01

    Glacier surface mass-balance measurements on Greenland started more than a century ago, but no compilation exists of the observations from the ablation area of the ice sheet and local glaciers. Such data could be used in the evaluation of modelled surface mass balance, or to document changes in glac

  18. Greenland surface mass-balance observations from the ice-sheet ablation area and local glaciers

    DEFF Research Database (Denmark)

    Machguth, Horst; Thomsen, Henrik; Weidick, Anker;

    2016-01-01

    Glacier surface mass-balance measurements on Greenland started more than a century ago, but no compilation exists of the observations from the ablation area of the ice sheet and local glaciers. Such data could be used in the evaluation of modelled surface mass balance, or to document changes in g...

  19. Remote Sensing Parameterization of Land Surface Heat Fluxes over Arid and Semi-arid Areas

    Institute of Scientific and Technical Information of China (English)

    马耀明; 王介民; 黄荣辉; 卫国安; MassimoMENENTI; 苏中波; 胡泽勇; 高峰; 文军

    2003-01-01

    Dealing with the regional land surfaces heat fluxes over inhomogeneous land surfaces in arid and semi-arid areas is an important but not an easy issue. In this study, one parameterization method based on satellite remote sensing and field observations is proposed and tested for deriving the regional land surface heat fluxes over inhomogeneous landscapes. As a case study, the method is applied to the Dunhuang experimental area and the HEIFE (Heihe River Field Experiment, 1988-1994) area. The Dunhuang area is selected as a basic experimental area for the Chinese National Key Programme for Developing Basic Sciences: Research on the Formation Mecbanism and Prediction Theory of Severe Climate Disaster in China (G1998040900, 1999-2003). The four scenes of Landsat TM data used in this study are 3 June 2000,22 August 2000, and 29 January 2001 for the Dunhuang area and 9 July 1991 for the HEIFE area. The regional distributions of land surface variables, vegetation variables, and heat fluxes over inhomogeneous landscapes in arid and semi-arid areas are obtained in this study.

  20. Greenland surface mass-balance observations from the ice-sheet ablation area and local glaciers

    DEFF Research Database (Denmark)

    Machguth, Horst; Thomsen, Henrik H.; Weidick, Anker;

    2016-01-01

    Glacier surface mass-balance measurements on Greenland started more than a century ago, but no compilation exists of the observations from the ablation area of the ice sheet and local glaciers. Such data could be used in the evaluation of modelled surface mass balance, or to document changes...... in glacier melt independently from model output. Here, we present a comprehensive database of Greenland glacier surface mass-balance observations from the ablation area of the ice sheet and local glaciers. The database spans the 123 a from 1892 to 2015, contains a total of similar to 3000 measurements from...

  1. Greenland surface mass-balance observations from the ice-sheet ablation area and local glaciers

    DEFF Research Database (Denmark)

    Machguth, Horst; Thomsen, Henrik H.; Weidick, Anker

    2016-01-01

    in glacier melt independently from model output. Here, we present a comprehensive database of Greenland glacier surface mass-balance observations from the ablation area of the ice sheet and local glaciers. The database spans the 123 a from 1892 to 2015, contains a total of similar to 3000 measurements from......Glacier surface mass-balance measurements on Greenland started more than a century ago, but no compilation exists of the observations from the ablation area of the ice sheet and local glaciers. Such data could be used in the evaluation of modelled surface mass balance, or to document changes...

  2. Determination of Surface Area of Red Mud and BeringiteUsing Methylene Blue Method

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The adsorption of methylene blue (MB) on three soil amendments, red mud from Hungary, red mud from UK and beringite from Belgium, was studied to determine the surface areas of the amendments using a 0.005 mol L-1 NaCl solution and deionised water as background solutions. The surface areas determined by the methylene blue method in the 0.005 mol L-1 NaCl solution were 3.357, 2.340 and 5.576 m2 g-1 for red nmd (Hungary), red mud (UK) and beringite, respectively, slightly lower than those in the deionised water system. The largest surface area of beringite suggested that the MB could adsorb effectively on the interlayer surface of illite. The effect of NaCl on the surface areas was relatively small and may therefore be ignored. Both the 0.005 mol L-1 NaCl solution and deionised water could be used as a background solution for measurement of surface area of oxide-rich materials.

  3. Euclidean Wilson loops and Minimal Area Surfaces in Minkowski AdS3

    CERN Document Server

    Irrgang, Andrew

    2015-01-01

    The AdS/CFT correspondence relates Wilson loops in N=4 SYM theory to minimal area surfaces in AdS5xS5 space. If the Wilson loop is Euclidean and confined to a plane (t,x) then the dual surface is Euclidean and lives in Minkowski AdS3. In this paper we study such minimal area surfaces generalizing previous results obtained in the Euclidean case. Since the surfaces we consider have the topology of a disk, the holonomy of the flat current vanishes which is equivalent to the condition that a certain boundary Schroedinger equation has all its solutions anti-periodic. If the potential for that Schroedinger equation is found then reconstructing the surface and finding the area become simpler. In particular we write a formula for the Area in terms of the Schwarzian derivative of the contour. Finally an infinite parameter family of analytical solutions using Riemann Theta functions is described. In this case, both the area and the shape of the surface are given analytically and used to check the previous results.

  4. Density and stability of soil organic carbon beneath impervious surfaces in urban areas.

    Science.gov (United States)

    Wei, Zongqiang; Wu, Shaohua; Yan, Xiao; Zhou, Shenglu

    2014-01-01

    Installation of impervious surfaces in urban areas has attracted increasing attention due to its potential hazard to urban ecosystems. Urban soils are suggested to have robust carbon (C) sequestration capacity; however, the C stocks and dynamics in the soils covered by impervious surfaces that dominate urban areas are still not well characterized. We compared soil organic C (SOC) densities and their stabilities under impervious surface, determined by a 28-d incubation experiment, with those in open areas in Yixing City, China. The SOC density (0-20 cm) under impervious surfaces was, on average, 68% lower than that in open areas. Furthermore, there was a significantly (Psoils, whereas the correlation was not apparent for the impervious-covered soils, suggesting that the artificial soil sealing in urban areas decoupled the cycle of C and N. Cumulative CO2-C evolved during the 28-d incubation was lower from the impervious-covered soils than from the open soils, and agreed well with a first-order decay model (Ct = C1+C0(1-e-kt)). The model results indicated that the SOC underlying capped surfaces had weaker decomposability and lower turnover rate. Our results confirm the unique character of urban SOC, especially that beneath impervious surface, and suggest that scientific and management views on regional SOC assessment may need to consider the role of urban carbon stocks.

  5. Time function of surface subsidence based on Harris model in mined-out area

    Institute of Scientific and Technical Information of China (English)

    Liu Xinrong; Wang Junbao; Guo Jianqiang; Yuan Hong; Li Peng

    2013-01-01

    The surface subsidence is a common environmental hazard in mined-out area.Based on careful analysis of the regularity of surface subsidence in mined-out area,we proposed a new time function based on Harris curve model in consideration of the shortage of current surface subsidence time functions.By analyzing the characteristics of the new time function,we found that it could meet the dynamic process,the velocity change process and the acceleration change process during surface subsidence.Then its rationality had been verified through project cases.The results show that the proposed time function model can give a good reflection of the regularity of surface subsidence in mined-out area and can accurately predict surface subsidence.And the prediction data of the model are a little greater than measured data on condition of proper measured data quantity,which is safety in the engineering.This model provides a new method for the analysis of surface subsidence in mined-out area and reference for future prediction,and it is valuable to engineering application.

  6. Gold-film coating assisted femtosecond laser fabrication of large-area, uniform periodic surface structures.

    Science.gov (United States)

    Feng, Pin; Jiang, Lan; Li, Xin; Rong, Wenlong; Zhang, Kaihu; Cao, Qiang

    2015-02-20

    A simple, repeatable approach is proposed to fabricate large-area, uniform periodic surface structures by a femtosecond laser. 20 nm gold films are coated on semiconductor surfaces on which large-area, uniform structures are fabricated. In the case study of silicon, cross-links and broken structures of laser induced periodic surface structures (LIPSSs) are significantly reduced on Au-coated silicon. The good consistency between the scanning lines facilitates the formation of large-area, uniform LIPSSs. The diffusion of hot electrons in the Au films increases the interfacial carrier densities, which significantly enhances interfacial electron-phonon coupling. High and uniform electron density suppresses the influence of defects on the silicon and further makes the coupling field more uniform and thus reduces the impact of laser energy fluctuations, which homogenizes and stabilizes large-area LIPSSs.

  7. Surface area and volume measurements of volcanic ash particles by SEM stereoscopic imaging

    Science.gov (United States)

    Ersoy, Orkun

    2010-05-01

    Surface area of volcanic ash particles is of great importance to research including plume dynamics, particle chemical and water reactions in the plume, modelling (i.e. plume shape, particle interactions , dispersion etc.), remote sensing of transport and SO2, HCl, H2O, CO2 levels, forecasting plume location, and transportation and deposition of ash particles. The implemented method presented in this study offer new insights for surface characterization of volcanic ash particles on macro-pore regions. Surface area and volumes of volcanic ash particles were measured using digital elevation models (DEM) reconstructed from stereoscopic images acquired from different angles by scanning electron microscope (SEM). The method was tested using glycidyl methacrylate (GMA) micro-spheres which exhibit low spherical imperfections. The differences between measured and geometrically calculated surface areas were introduced for both micro-spheres and volcanic ash particles in order to highlight the probable errors in modelling on volcanic ash behaviour. The specific surface areas of volcanic ash particles using this method are reduced by half (from mean values of 0.045 m2/g to 0.021 m2/g) for the size increment 63 μm to 125 μm. Ash particles mostly have higher specific surface area values than the geometric forms irrespective of particle size. The specific surface area trends of spheres and ash particles resemble for finer particles (63 μm). Approximation to sphere and ellipsoid have similar margin of error for coarser particles (125 μm) but both seem to be inadequate for representation of real ash surfaces.

  8. The impact of surface area, volume, curvature, and Lennard-Jones potential to solvation modeling.

    Science.gov (United States)

    Nguyen, Duc D; Wei, Guo-Wei

    2017-01-05

    This article explores the impact of surface area, volume, curvature, and Lennard-Jones (LJ) potential on solvation free energy predictions. Rigidity surfaces are utilized to generate robust analytical expressions for maximum, minimum, mean, and Gaussian curvatures of solvent-solute interfaces, and define a generalized Poisson-Boltzmann (GPB) equation with a smooth dielectric profile. Extensive correlation analysis is performed to examine the linear dependence of surface area, surface enclosed volume, maximum curvature, minimum curvature, mean curvature, and Gaussian curvature for solvation modeling. It is found that surface area and surfaces enclosed volumes are highly correlated to each other's, and poorly correlated to various curvatures for six test sets of molecules. Different curvatures are weakly correlated to each other for six test sets of molecules, but are strongly correlated to each other within each test set of molecules. Based on correlation analysis, we construct twenty six nontrivial nonpolar solvation models. Our numerical results reveal that the LJ potential plays a vital role in nonpolar solvation modeling, especially for molecules involving strong van der Waals interactions. It is found that curvatures are at least as important as surface area or surface enclosed volume in nonpolar solvation modeling. In conjugation with the GPB model, various curvature-based nonpolar solvation models are shown to offer some of the best solvation free energy predictions for a wide range of test sets. For example, root mean square errors from a model constituting surface area, volume, mean curvature, and LJ potential are less than 0.42 kcal/mol for all test sets. © 2016 Wiley Periodicals, Inc.

  9. A mathematical analysis of an exchange-traded horse race betting fund with deterministic payoff betting strategy for institutional investment to challenge EMH

    Directory of Open Access Journals (Sweden)

    Craig George Leslie Hopf

    2015-12-01

    Full Text Available This paper’s primary alternative hypothesis is Ha: profitable exchange-traded horserace betting fund with deterministic payoff exists for acceptable institutional portfolio return—risk. The primary hypothesis challenges the semi-strong efficient market hypothesis applied to horse race wagering. An optimal deterministic betting model (DBM is derived from the existing stochastic model fundamentals, mathematical pooling principles, and new theorem. The exchange-traded betting fund (ETBF is derived from force of interest first principles. An ETBF driven by DBM processes conjointly defines the research’s betting strategy. Alpha is excess return above financial benchmark, and invokes betting strategy alpha that is composed of model alpha and fund alpha. The results and analysis from statistical testing of a global stratified data sample of three hundred galloper horse races accepted at the ninety-five percent confidence-level positive betting strategy alpha, to endorse an exchange-traded horse race betting fund with deterministic payoff into financial market.

  10. Estimating surface fluxes over the north Tibetan Plateau area with ASTER imagery

    Directory of Open Access Journals (Sweden)

    Weiqiang Ma

    2009-01-01

    Full Text Available Surface fluxes are important boundary conditions for climatological modeling and Asian monsoon system. The recent availability of high-resolution, multi-band imagery from the ASTER (Advanced Space-borne Thermal Emission and Reflection radiometer sensor has enabled us to estimate surface fluxes to bridge the gap between local scale flux measurements using micrometeorological instruments and regional scale land-atmosphere exchanges of water and heat fluxes that are fundamental for the understanding of the water cycle in the Asian monsoon system. A parameterization method based on ASTER data and field observations has been proposed and tested for deriving surface albedo, surface temperature, Normalized Difference Vegetation Index (NDVI, Modified Soil Adjusted Vegetation Index (MSAVI, vegetation coverage, Leaf Area Index (LAI, net radiation flux, soil heat flux, sensible heat flux and latent heat flux over heterogeneous land surface in this paper. As a case study, the methodology was applied to the experimental area of the Coordinated Enhanced Observing Period (CEOP Asia-Australia Monsoon Project (CAMP on the Tibetan Plateau (CAMP/Tibet, located at the north Tibetan Plateau. The ASTER data of 24 July 2001, 29 November 2001 and 12 March 2002 was used in this paper for the case of summer, winter and spring. To validate the proposed methodology, the ground-measured surface variables (surface albedo and surface temperature and land surface heat fluxes (net radiation flux, soil heat flux, sensible heat flux and latent heat flux were compared to the ASTER derived values. The results show that the derived surface variables and land surface heat fluxes in three different months over the study area are in good accordance with the land surface status. Also, the estimated land surface variables and land surface heat fluxes are in good accordance with ground measurements, and all their absolute percentage difference (APD is less than 10% in the validation sites

  11. The state of the online sport betting industry in South Africa

    OpenAIRE

    Nienaber, Maxine B.

    2016-01-01

    Abstract: Online sport betting is not only a means of entertainment but is also an income generating means for Governments and organisations around the world. Up until 1994 online sport betting in South Africa was illegal. Consequently many travelled outside of South African borders to participate in gambling activities which meant that the Government was losing huge sums of tax revenue. The legalisation of online sport betting in 1994 meant that Governments could now benefit from this type o...

  12. BET, thermal degradation, and FTIR spectras of triazine polyamine polymers.

    Science.gov (United States)

    Can, Mustafa

    2017-04-01

    Here we show effect of the polyamine polymer chain length to BET isotherms. According to IUPAC classification [1], all three polymers are fitting type 1 physical adsorption isotherm with H3 hysteresis (except for EDA having H2 hysteresis). Moreover, TG and TGA analysis of polymers triazine-ethylenediamine (EDA) and triazine-triethylenetetramine (TETA) are provided. Due to the similarities of the structure, main decomposition temperatures are close to each other (between 593 K and 873 K). In order to understand change of FTIR spectra with adsorption and stripping Au(III), fresh, Au(III) adsorbed and recycled spectras of polymers measured. For further discussions about the effect of chain length to adsorption of Au(III) onto triazine polyamine polymer particles "Au (III) Uptake by Triazine Polyamine Polymers: Mechanism, Kinetic and Equilibrium Studies" Can et al. [2] (article in press).

  13. Can We Trust Real Time Measurements of Lung Deposited Surface Area Concentrations in Dust from Powder Nanomaterials?

    DEFF Research Database (Denmark)

    Levin, Marcus; Witschger, Olivier; Bau, Sebastien

    2016-01-01

    A comparison between various methods for real-time measurements of lung deposited surface area (LDSA) using spherical particles and powder dust with specific surface area ranging from 0.03 to 112 m2 g-1 was conducted. LDSA concentrations measured directly using Nanoparticle Surface Area Monitor...

  14. Geohydrology and susceptibility of major aquifers to surface contamination in Alabama; area 4

    Science.gov (United States)

    Planert, Michael; Pritchett, J.L.

    1989-01-01

    The U.S. Geological Survey, in cooperation with the Alabama Department of Environmental Management, is conducting a series of geohydrologic studies to delineate the major aquifers (those which provide water for public supplies) in Alabama, their recharge areas, and areas susceptible to contamination. This report summarizes these factors for two major aquifers in Area 4--Calhoun, Jefferson, St. Clair, Shelby, and Talladega Counties. The major aquifers in the study area are in Cambrian and Ordovician and Mississippian rocks. Highest yields from aquifers are associated with solution openings in carbonate rocks. Springs in the area provide substantial amounts of water for municipal supply. Coldwater Spring provides 17 million gal of water/day to the city of Anniston, the largest groundwater user in the area. All recharge areas for the aquifers are susceptible to contamination from land surface. Two conditions exist in the study area that may cause the aquifers to be highly susceptible to contamination on a local scale: fracturing of rock materials due to faulting and the production of a porous cherty soil through weathering. Where sinkholes are present, there may be a direct connection between the land surface and the aquifer. Areas with sinkholes are considered to be extremely susceptible to contamination. (USGS)

  15. APPLICATION OF HIERARCHY ARTIFICIAL NEURAL NETWORK TO EVALUATE THE EXPLOITATION CONDITITONS OF SURFACE MINING AREA

    Institute of Scientific and Technical Information of China (English)

    李新春; 范力军

    1998-01-01

    It always adopts the direct hierarchy analysis to value the exploitation conditions of surface mining areas. This way has some unavoidable shortcomings because it is mainly under theaid of experts and it is affected by the subjective thinking of the experts. This paper puts forwards a new approach that divides the whole exploitation conditions into sixteen subsidiary systems and each subsidiary system forms a neural network system. The whole decision system of exploitation conditions of surface mining areas is composed of sixteen subsidiary neural network systems. Each neural network is practiced with the data of the worksite, which is reasonable and scientific. This way will be a new decision approach for exploiting the surface mining areas.

  16. Correlating Humidity-Dependent Ionically Conductive Surface Area with Transport Phenomena in Proton-Exchange Membranes

    Energy Technology Data Exchange (ETDEWEB)

    He, Qinggang; Kusoglu, Ahmet; Lucas, Ivan T.; Clark, Kyle; Weber, Adam Z.; Kostecki, Robert

    2011-08-01

    The objective of this effort was to correlate the local surface ionic conductance of a Nafion? 212 proton-exchange membrane with its bulk and interfacial transport properties as a function of water content. Both macroscopic and microscopic proton conductivities were investigated at different relative humidity levels, using electrochemical impedance spectroscopy and current-sensing atomic force microscopy (CSAFM). We were able to identify small ion-conducting domains that grew with humidity at the surface of the membrane. Numerical analysis of the surface ionic conductance images recorded at various relative humidity levels helped determine the fractional area of ion-conducting active sites. A simple square-root relationship between the fractional conducting area and observed interfacial mass-transport resistance was established. Furthermore, the relationship between the bulk ionic conductivity and surface ionic conductance pattern of the Nafion? membrane was examined.

  17. Description of surface systems. Preliminary site description Simpevarp sub area - Version 1.2

    Energy Technology Data Exchange (ETDEWEB)

    Lindborg, Tobias (ed.)

    2005-03-01

    Swedish Nuclear Fuel and Waste Management Co is currently conducting site characterisation in the Simpevarp area. The area is divided into two subareas, the Simpevarp and the Laxemar subarea. The two subareas are surrounded by a common regional model area, the Simpevarp area. This report describes both the regional area and the subareas. This report is an interim version (model version 1.2) of the description of the surface systems at the Simpevarp area, and should be seen as a background report to the site description of the Simpevarp area, version 1.2, SKB-R--05-08. The basis for this description is quality-assured field data available in the SKB SICADA and GIS databases, together with generic data from the literature. The Surface system, here defined as everything above the bedrock, comprises a number of separate disciplines (e.g. hydrology, geology, topography, oceanography and ecology). Each discipline has developed descriptions and models for a number of properties that together represent the site description. The current methodology for developing the surface system description and the integration to ecosystem models is documented in a methodology strategy report SKB-R--03-06. The procedures and guidelines given in that report were followed in this report. Compared with version 1.1 of the surface system description SKB-R--04-25, this report presents considerable additional features, especially in the ecosystem description (Chapter 4) and in the description of the surface hydrology (Section 3.4). A first attempt has also been made to connect the flow of matter (carbon) between the different ecosystems into an overall ecosystem model at a landscape level. A summarised version of this report is also presented in SKB-R--05-08 together with geological-, hydrogeological-, transport properties-, thermal properties-, rock mechanics- and hydrogeochemical descriptions.

  18. Heavy metal contamination in surface runoff sediments of the urban area of Vilnius, Lithuania

    Directory of Open Access Journals (Sweden)

    Gytautas Ignatavičius

    2017-02-01

    Full Text Available Surface runoff from urbanized territories carries a wide range of pollutants. Sediments in untreated runoff from direct discharge stormwater systems significantly contribute to urban waterway pollution. In this study, heavy metal (Pb, Zn, Cu, Cr, Ba, As and Fe contamination in surface runoff sediments of the urban area of the city of Vilnius was investigated. The surface runoff sediment samples were collected from seven dischargers with the highest volume rate of water flow and concentrations of suspended solids. The geospatial analysis of the distribution of heavy metals shows that there are several active pollution sources supplying the dischargers with contaminated sediments. Most of these areas are located in the central part of the city and in old town with intense traffic. Principal components analysis and t-test results clearly depicted the significantly different chemical compositions of winter and autumn surface sediment samples. The sampling approach and assessment of results provide a useful tool to examine the contamination that is generated in urban areas, distinguish pollution sources and give a better understanding of the importance of permeable surfaces and green areas.

  19. Changes in surface area and concentrations of semivolatile organic contaminants in aging snow.

    Science.gov (United States)

    Burniston, Debbie A; Strachan, William J M; Hoff, John T; Wania, Frank

    2007-07-15

    During the winter of 1999/2000 five snowpacks at Turkey Lake Watershed east of Lake Superior were sampled immediately after falling and again after several days of aging for the analysis of specific snow surface area and the concentrations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs). The snow surface could be determined with a relative coefficient of variation of 6% using frontal chromatography, measuring the retention of ethyl acetate, a substance with known adsorption coefficient on the ice surface. The snow surface area of fresh snow varied from 1000 to 1330 cm2/g and was higher for snow falling during colder days. The aged snow samples had consistently lower surface areas ranging from 520 to 780 cm2/g, corresponding to an average loss of half of the initial surface area during aging. The rate of loss of surface area was faster at higher temperatures. Dieldrin, alpha-HCH, and gamma-HCH were the most abundant OCPs in snowmelt water, but endosulfan, chlordane-related substances, heptachlor epoxide, pp'-DDT, pp'-DDE, and chlorinated benzenes were also consistently present. Three midwinter snowpacks that aged during relatively cold temperatures generally experienced a loss of PCBs and OCPs that was of the same order of magnitude as the observed loss of snow surface area. However, no relationship between the extent of loss and the strength of a contaminants' sorption to snow was apparent. Few significant changes in snowpack concentrations of OCPs and PCBs were observed in a snowpack that fell at relatively high temperatures and aged under colder conditions. Concentrations of OCPs and PCBs increased in a late-winter snowpack that aged while temperatures rapidly increased to above freezing. Concentrations of pp'-DDE and endosulfan-II that increased in snowpacks that saw simultaneous decreases in the levels of pp'-DDT and endosulfan-I hint at the occurrence of sunlight induced conversions in snow. While surface area decreases clearly

  20. Laser Carbonization of PAN-Nanofiber Mats with Enhanced Surface Area and Porosity.

    Science.gov (United States)

    Go, Dennis; Lott, Philipp; Stollenwerk, Jochen; Thomas, Helga; Möller, Martin; Kuehne, Alexander J C

    2016-10-17

    Here we present a novel laser process to generate carbon nanofiber nonwovens from polyacrylonitrile. We produce carbon nanofabrics via electrospinning followed by infrared laser-induced carbonization, facilitating high surface area and well-controlled hierarchical porosity. The process allows precise control of the carbonization conditions and provides high nanoscale porosity. In comparison with classical thermal carbonization, the laser process produces much higher surface areas and smaller pores. Furthermore, we investigate the carbonization performance and the morphology of polyacrylonitrile nanofibers compounded with graphene nanoplatelet fillers.

  1. Preparation of Zirconia-Ceria Powders with High Specific Surface Area

    Institute of Scientific and Technical Information of China (English)

    Wang Enguo; Mei Fang

    2004-01-01

    Zirconia-ceria mixed oxide powders were prepared by high temperature aging method.The effects of the temperature and the time of aging, cerium content and calcination on powder performance were studied.The result shows that high temperature aging is an efficient way of preparation of ZrO2-CeO2 mixed oxide powders with high specific surface area and good thermal stability, and that addition of a small amount of cerium to hydrous zirconia can promote the preparation of high specific surface area powders.

  2. A process to enhance the specific surface area and capacitance of hydrothermally reduced graphene oxide

    KAUST Repository

    Alazmi, Amira

    2016-08-26

    The impact of post-synthesis processing in reduced graphene oxide materials for supercapacitor electrodes has been analyzed. A comparative study of vacuum, freeze and critical point drying was carried out for hydrothermally reduced graphene oxide demonstrating that the optimization of the specific surface area and preservation of the porous network are critical to maximize its supercapacitance performance. As described below, using a supercritical fluid as the drying medium, unprecedented values of the specific surface area (364 m2 g−1) and supercapacitance (441 F g−1) for this class of materials have been achieved.

  3. From infinitesimal to full contact between rough surfaces: evolution of the contact area

    CERN Document Server

    Yastrebov, Vladislav A; Molinari, Jean-François

    2014-01-01

    We carry out a statistically meaningful study on self-affine rough surfaces in elastic frictionless non-adhesive contact. We study the evolution of the true contact area under increasing squeezing pressure. Rough surfaces are squeezed from zero up to full contact, which enables us to compare the numerical results both with asperity based models at light pressures and with Persson's contact model for the entire range of pressures. Through the contact perimeter we estimate the error bounds inherent to contact area calculation in discrete problems. A large number of roughness realizations enables us to compute reliably the derivative of the contact area with respect to the pressure. In contrast to Persson's model and in agreement with asperity based models, we demonstrate that at light pressures it is a decreasing convex function. The nonlinearity of the contact area evolution, preserved for the entire range of pressures, is especially strong close to infinitesimal contact. This fact makes difficult an accurate ...

  4. Sediment Surface Areas, Organic Content, and Metal Fractionation of Point Mugu Sediments

    Science.gov (United States)

    Becerra, C. A.; Wong, N.; Khachikian, C. S.

    2002-12-01

    Point Mugu contains one of the largest coastal wetlands ecosystems in California, which includes a Naval Air station, several sewage oxidation ponds and a partly dredged lagoon. Remediation efforts include investigating the feasibility of using the present sewage pond sludge to restore a dredged area in the lagoon. A problem with this approach is the potential release and subsequent environmental impact of the toxic substances from the sludge. Contaminants may become unavailable once sorbed onto particles. In general, this process is a direct function of surface area and organic carbon sorbed onto the sediment. The goal of the current investigation is to provide insight into the biological availability of a suite of metal contaminants in Pt. Mugu marsh sediments by studying changes in the physical and chemical properties of the sediments at horizontal and vertical spatial scales. The surface area and organic carbon for eight cores were measured as well as the first three sequential extraction of a host of metals. We have found that a direct correlation exists between surface area and the organic content of sediments as a function of depth. Surface area and the amount of organic carbon decreases with depth, which could result in higher availability of metals with increasing depth into the sediments.

  5. Evaporation and wetted area of single droplets on waxy and hairy leaf surfaces.

    Science.gov (United States)

    Zhu, H; Yu, Y; Ozkan, H E; Derksen, R C; Krause, C R

    2008-01-01

    Understanding the evaporation of pesticide droplets and wetting of Leaf surfaces can increase foliar application efficiency and reduce pesticide use. Evaporation time and wetted area of single pesticide droplets on hairy and waxy geranium leaf surfaces were measured under the controlled conditions for five droplet sizes and three relative humidities. The sprays used to form droplets included water, a nonionic colloidal polymer drift retardant, an alkyl polyoxyethylene surfactant, and an insecticide. Adding the surfactant into spray mixtures greatly increased droplet wetted area on the surfaces while droplet evaporation time was greatly reduced. Adding the drift retardant into spray mixture slightly increased the droplet evaporation time and the wetted area. Also, droplets had Longer evaporation times on waxy leaves than on hairy leaves for all droplet diameters and all relative humidity conditions. Increasing relative humidity could increase the droplet evaporation time greatly but did not change the the wetted area. The droplet evaporation time and wetted area increased exponentially as the droplet size increased. Therefore, droplet size, surface characteristics of the target, relative humidity, and chemical composition of the spray mixtures (water alone, pesticide, additives) should be included as important factors that affect the efficacy and efficiency of pesticide applications.

  6. General models for the spectra of surface area scaling strategies of cells and organisms: fractality, geometric dissimilitude, and internalization.

    Science.gov (United States)

    Okie, Jordan G

    2013-03-01

    Surface areas and volumes of biological systems-from molecules to organelles, cells, and organisms-affect their biological rates and kinetics. Therefore, surface area-to-volume ratios and the scaling of surface area with volume profoundly influence ecology, physiology, and evolution. The zeroth-order geometric expectation is that surface area scales with body mass or volume as a power law with an exponent of two-thirds, with consequences for surface area-to-volume (SA : V) ratios and constraints on size; however, organisms have adaptations for altering the surface area scaling and SA : V ratios of their bodies and structures. The strategies fall into three groups: (1) fractal-like surface convolutions and crinkles; (2) classic geometric dissimilitude through elongating, flattening, fattening, and hollowing; and (3) internalization of surfaces. Here I develop general quantitative theory to model the spectra of effects of these strategies on SA : V ratios and surface area scaling, from exponents of less than two-thirds to superlinear scaling and mixed-power laws. Applying the theory to cells helps quantitatively evaluate the effects of membrane fractality, shape-shifting, vacuoles, vesicles, and mitochondria on surface area scaling, informing understanding of cell allometry, morphology, and evolution. Analysis of compiled data indicates that through hollowness and surface internalization, eukaryotic phytoplankton increase their effective surface area scaling, attaining near-linear scaling in larger cells. This unifying theory highlights the fundamental role of biological surfaces in metabolism and morphological evolution.

  7. Analysis of the Contact Area of Smooth and Rough Surfaces in Contact with Sphere Indenter Using Finite Element Method

    Directory of Open Access Journals (Sweden)

    Kartini

    2016-01-01

    Full Text Available This paper analyzes the contact area of the contact between a deformable rough surface (smooth and rough and a hard smooth sphere indenter using finite element method. A method was introduced to generate a three dimensional rough surfaces using Computer Aided Design (CAD software. The rough surface model was developed based on the surface measurement data, while the smooth surface model was generated from the CAD software. Contact area and contact deformation were analyzed. Results showed that the contact area between rough surface versus sphere and smooth surface versus sphere is different.

  8. Transparent self-cleaning lubricant-infused surfaces made with large-area breath figure patterns

    Science.gov (United States)

    Zhang, Pengfei; Chen, Huawei; Zhang, Liwen; Ran, Tong; Zhang, Deyuan

    2015-11-01

    Nepenthes pitcher inspired slippery lubricant-infused porous surfaces greatly impact the understanding of liquid-repellent surfaces construction and have attracted extensive attention in recent years due to their potential applications in self-cleaning, anti-fouling, anti-icing, etc. In this work, we have successfully fabricated transparent slippery lubricant-infused surfaces based on breath figure patterns (BFPs). Large-area BFPs with interconnected pores were initially formed on the glass substrate and then a suitable lubricant was added onto the surfaces. The interconnected pores in BFPs were able to hold the lubricant liquid in place and form a stable liquid/solid composite surface capable of repelling a variety of liquids. The liquid-repellent surfaces show extremely low critical sliding angles for various liquids, thus providing the surfaces with efficient self-cleaning property. It was also found that the liquid droplets' sliding behaviors on the surfaces were significantly influenced by the tilting angle of the substrate, liquid volume, liquid chemical properties, and pore sizes of the surfaces.

  9. Lactose electroisomerization into lactulose: effect of the electrode material, active membrane surface area-to-electrode surface area ratio, and interelectrode-membrane distance.

    Science.gov (United States)

    Aït-Aissa, Amara; Aïder, Mohammed

    2014-01-01

    The aim of the present work was to study and develop an innovative, clean, and environmentally friendly process for lactulose synthesis by electroactivation of lactose. In this work, the electrode material (type 304 stainless steel, titanium, and copper), dimensionless interelectrode-membrane distance at the cathodic compartment (0.36, 0.68, and 1), and the membrane:electrode surface area ratio (0.23, 0.06, and 0.015) were considered to be the factors that could affect the kinetic conversion of lactose into lactulose. The reactions were conducted under an initial lactose concentration of 0.15mol/L at 10°C, Froude number (mixing speed) of 2.05×10(-2), and electric current intensity of 300mA for 30min. The highest lactulose formation yield of 32.50% (0.05mol/L) was obtained by using a copper electrode, interelectrode-membrane distance of 0.36, and membrane:electrode surface area ratio of 0.23. The 2-parameter Langmuir, Freundlich, and Temkin isotherm models were used for the prediction of the lactose isomerization kinetics as well as the 3-parameter Langmuir-Freundlich isotherm model. It was shown that the lactose isomerization kinetics into lactulose followed the Temkin and Langmuir-Freundlich models with coefficients of determination of 0.99 and 0.90 and a relative error of 1.42 to 1.56% and 4.27 to 4.37%, respectively.

  10. Changing surface-atmosphere energy exchange and refreezing capacity of the lower accumulation area, West Greenland

    Science.gov (United States)

    Charalampidis, C.; van As, D.; Box, J. E.; van den Broeke, M. R.; Colgan, W. T.; Doyle, S. H.; Hubbard, A. L.; MacFerrin, M.; Machguth, H.; Smeets, C. J. P. P.

    2015-11-01

    We present 5 years (2009-2013) of automatic weather station measurements from the lower accumulation area (1840 m a.s.l. - above sea level) of the Greenland ice sheet in the Kangerlussuaq region. Here, the summers of 2010 and 2012 were both exceptionally warm, but only 2012 resulted in a strongly negative surface mass budget (SMB) and surface meltwater run-off. The observed run-off was due to a large ice fraction in the upper 10 m of firn that prevented meltwater from percolating to available pore volume below. Analysis reveals an anomalously low 2012 summer-averaged albedo of 0.71 (typically ~ 0.78), as meltwater was present at the ice sheet surface. Consequently, during the 2012 melt season, the ice sheet surface absorbed 28 % (213 MJ m-2) more solar radiation than the average of all other years. A surface energy balance model is used to evaluate the seasonal and interannual variability of all surface energy fluxes. The model reproduces the observed melt rates as well as the SMB for each season. A sensitivity analysis reveals that 71 % of the additional solar radiation in 2012 was used for melt, corresponding to 36 % (0.64 m) of the 2012 surface lowering. The remaining 64 % (1.14 m) of surface lowering resulted from high atmospheric temperatures, up to a +2.6 °C daily average, indicating that 2012 would have been a negative SMB year at this site even without the melt-albedo feedback. Longer time series of SMB, regional temperature, and remotely sensed albedo (MODIS) show that 2012 was the first strongly negative SMB year, with the lowest albedo, at this elevation on record. The warm conditions of recent years have resulted in enhanced melt and reduction of the refreezing capacity in the lower accumulation area. If high temperatures continue, the current lower accumulation area will turn into a region with superimposed ice in coming years.

  11. Effects of surface oxygen on charge storage in high surface area early transition-metal carbides and nitrides

    Science.gov (United States)

    Djire, Abdoulaye; Ajenifujah, Olabode T.; Sleightholme, Alice E. S.; Rasmussen, Paul; Thompson, Levi T.

    2015-02-01

    The effect of surface oxygen on the physical and electrochemical properties of high surface area Mo, V and W carbides and nitrides has been investigated. These materials hold promise for use in supercapacitors and other electrochemical conversion devices. The carbides and nitrides were synthesized using a temperature programmed reaction method and passivated to avoid bulk oxidation on exposure to air. The passivated materials were activated in 0.3 mol dm-3 NaOH solution to remove the oxygen-rich passivation layer. This activation resulted in significant changes in the electrochemical stabilities and capacitances. The surface areas for the Mo and W-based materials were higher after activation, with the effect ranging from an 11% increase for Mo2N to a 208% increase for W2C. An increase in pore volume and mesopore density was also observed for most of the materials. Interestingly, the VC and W2C, which were electrochemically unstable in acidic electrolyte in their passivated form, were stable after activation. The capacitances of all of the materials were increased after activation with the effect ranging from 48% for Mo2N to a 79% increase for (α + β)-Mo2C. This activation process could be used to improve the performance of carbide and nitride-based supercapacitor electrode materials.

  12. Specific surface area effect on adsorption of chlorpyrifos and TCP by soils and modeling

    Science.gov (United States)

    The adsorption of chlorpyrifos and TCP (3,5,6, trichloro-2-pyridinol) was determined in four soils (Mollisol, Inceptisol, Entisol, Alfisol) having different specific surface areas (19–84 m2/g) but rather similar organic matter content (2.4–3.5%). Adsorption isotherms were derived from batch equilibr...

  13. Fabrication of nanoelectromechanical systems via the integration of high surface area glancing angle deposition thin films

    Science.gov (United States)

    Westwood, J. N.; Sauer, V. T. K.; Kwan, J. K.; Hiebert, W. K.; Sit, J. C.

    2014-06-01

    Nanoelectromechanical systems (NEMS) coated with a high surface area thin film are fabricated. Glancing angle deposition (GLAD) is used to uniformly deposit high surface area, nanostructured SiO2 films on top of released NEMS. The resonance frequencies and quality factors are measured to assess the potential of the high surface area NEMS for sensing experiments. Resonance frequencies of coated cantilevers, although reduced by mass loading, can be predicted accurately using our derived model. Compressive stress makes the resonance frequencies of coated doubly-clamped beams difficult to predict. The quality factors of the coated NEMS are reduced by one order of magnitude by a quasi-continuous layer at the base of the GLAD film, which also introduces an estimated compressive stress of 5.3-9.3 MPa. The limit of detection is demonstrated to be ˜2 pg cm-2. With this successful proof-of-concept demonstration, we anticipate the future use of these devices as high surface area gravimetric mass sensors for applications such as gas chromatography.

  14. An empirical method for estimating surface area of aggregates in hot mix asphalt

    Directory of Open Access Journals (Sweden)

    R.P. Panda

    2016-04-01

    Full Text Available Bitumen requirement in hot mix asphalt (HMA is directly dependent on the surface area of the aggregates in the mix, which in turn has effect on the asphalt film thickness and the flow characteristics. The surface area of aggregate blend in HMA is calculated using the specific surface area factors assigned to percentage passing through some specific standard sieve sizes and the imaging techniques. The first process is less capital intensive, but purely manual and labour intensive and prone to human errors. Imaging techniques though eliminating the human errors, still have limited use due to capital intensiveness and requirement of well-established laboratories with qualified technicians. Most of the developing countries like India are shortage of well-equipped laboratories and qualified technicians. To overcome these difficulties, the present mathematical model has been developed to estimate the surface area of aggregate blend of HMA from physical properties of aggregates evaluated using simple laboratory equipment. This model has been validated compared with the existing established methods of calculations and can be used as one of the tools in different developing and under developed countries for proper design of HMA.

  15. Turbostratic boron nitride coated on high-surface area metal oxide templates

    DEFF Research Database (Denmark)

    Klitgaard, Søren Kegnæs; Egeblad, Kresten; Brorson, M.

    2007-01-01

    Boron nitride coatings on high-surface area MgAl2O4 and Al2O3 have been synthesized and characterized by transmission electron microscopy and by X-ray powder diffraction. The metal oxide templates were coated with boron nitride using a simple nitridation in a flow of ammonia starting from ammonium...

  16. Uniform, large surface-area polarization by modifying corona-electrodes geometry.

    Science.gov (United States)

    Tansel, T; Ener Rusen, S; Rusen, A

    2013-01-01

    We report on the uniform, large scale polarization of ferroelectric materials by a newly designed corona charging technique developing nonconventional electrodes geometry. The results of pyroelectric measurements represented the spatial homogeneity of the polarization attained through a surface area of ~25 cm(2).

  17. Dose banding as an alternative to body surface area-based dosing of chemotherapeutic agents

    NARCIS (Netherlands)

    E. Chatelut (Etienne); M.L. White-Koning (M.); A.H.J. Mathijssen (Ron); F. Puisset (F.); S.D. Baker (Sharyn); A. Sparreboom (Alex)

    2012-01-01

    textabstractBackground: Dose banding is a recently suggested dosing method that uses predefined ranges (bands) of body surface area (BSA) to calculate each patients dose by using a single BSA-value per band. Thus, drugs with sufficient long-term stability can be prepared in advance. The main advanta

  18. Should blood flow during cardiopulmonary bypass be individualized more than to body surface area?

    DEFF Research Database (Denmark)

    Thomassen, Sisse Anette; Larsson, A; Andreasen, Jan Jesper;

    Blood flow during cardiopulmonary bypass (CPB) is calculated on body surface area (BSA). Increasing comorbidity, age and weight of today's cardiac patients question this calculation as it may not reflect individual metabolic requirement. The hypothesis was that a measured cardiac index (CI) prior...... not improve cerebral and systemic oxygenation compared to a blood flow based on BSA....

  19. Escaping the correction for body surface area when calculating glomerular filtration rate in children

    Energy Technology Data Exchange (ETDEWEB)

    Piepsz, Amy; Tondeur, Marianne [CHU St. Pierre, Department of Radioisotopes, Brussels (Belgium); Ham, Hamphrey [University Hospital Ghent, Department of Nuclear Medicine, Ghent (Belgium)

    2008-09-15

    {sup 51}Cr ethylene diamine tetraacetic acid ({sup 51}Cr EDTA) clearance is nowadays considered as an accurate and reproducible method for measuring glomerular filtration rate (GFR) in children. Normal values in function of age, corrected for body surface area, have been recently updated. However, much criticism has been expressed about the validity of body surface area correction. The aim of the present paper was to present the normal GFR values, not corrected for body surface area, with the associated percentile curves. For that purpose, the same patients as in the previous paper were selected, namely those with no recent urinary tract infection, having a normal left to right {sup 99m}Tc MAG3 uptake ratio and a normal kidney morphology on the early parenchymal images. A single blood sample method was used for {sup 51}Cr EDTA clearance measurement. Clearance values, not corrected for body surface area, increased progressively up to the adolescence. The percentile curves were determined and allow, for a single patient, to estimate accurately the level of non-corrected clearance and the evolution with time, whatever the age. (orig.)

  20. High surface area carbon for bifunctional air electrodes applied in zinc-air batteries

    Energy Technology Data Exchange (ETDEWEB)

    Arai, H. [on leave from NTT Laboratories (Japan); Mueller, S.; Haas, O. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    Bifunctional air electrodes with high surface area carbon substrates showed low reduction overpotential, thus are promising for enhancing the energy efficiency and power capability of zinc-air batteries. The improved performance is attributed to lower overpotential due to diffusion of the reaction intermediate, namely the peroxide ion. (author) 1 fig., 2 refs.

  1. Flexible shrink-induced high surface area electrodes for electrochemiluminescent sensing.

    Science.gov (United States)

    Pegan, Jonathan D; Ho, Adrienne Y; Bachman, Mark; Khine, Michelle

    2013-11-07

    Photolithographically defined metallic thin film on commodity shrink-wrap is leveraged to create robust electrodes. By thermally shrinking the film, electrodes are reduced by 20× in footprint for improved resolution and conductivity with >600% enhancements in electrochemically active surface area; as electrochemiluminescent sensors, they demonstrate improved limits of detection.

  2. Dialyzer membranes: effect of surface area and chemical modification of cellulose on complement and platelet activation.

    Science.gov (United States)

    Mahiout, A; Meinhold, H; Kessel, M; Schulze, H; Baurmeister, U

    1987-04-01

    Using an ex vivo model, the effects of membrane composition and surface area on both the complement system (as reflected by plasma C3a levels) and platelets [as indicated by plasma concentrations of thromboxane B2 (TXB2) and platelet factor 4 (PF4)] were studied. In this model, polyacrylonitrile (PAN) was associated with less complement activation than cuprammonium cellulose (CC). A new "modified cellulose" (MC) membrane, in which a small number of the free hydroxyl groups on cellulose are substituted with a tertiary amino compound, was also associated with a low degree of complement activation, similar to that with PAN. However, the extent of hydroxyl group substitution in four MC membrane subtypes did not correlate with the reduction in complement activation. In studies using CC, the amount of generated C3a correlated with the membrane surface area, although the relationship was curvilinear. Plasma concentrations at the "dialyzer" outlet of TXB2 and PF4 were similar with CC, PAN, and MC. In studies with the MC subtypes, increasing the extent of hydroxyl group substitution paradoxically increased, albeit slightly, the amount of TXB2 generation. In studies with CC, a linear relationship between membrane surface area and TXB2 generation was found. The results suggest a dissociation between platelet and complement effects among different dialyzer membranes, and underline the importance of membrane surface area.

  3. Minimal area surfaces dual to Wilson loops and the Mathieu equation

    Science.gov (United States)

    Huang, Changyu; He, Yifei; Kruczenski, Martin

    2016-08-01

    The AdS/CFT correspondence relates Wilson loops in {N}=4 SYM to minimal area surfaces in AdS 5 × S 5 space. Recently, a new approach to study minimal area surfaces in AdS 3 ⊂ AdS 5 was discussed based on a Schroedinger equation with a periodic potential determined by the Schwarzian derivative of the shape of the Wilson loop. Here we use the Mathieu equation, a standard example of a periodic potential, to obtain a class of Wilson loops such that the area of the dual minimal area surface can be computed analytically in terms of eigenvalues of such equation. As opposed to previous examples, these minimal surfaces have an umbilical point (where the principal curvatures are equal) and are invariant under λ-deformations. In various limits they reduce to the single and multiple wound circular Wilson loop and to the regular light-like polygons studied by Alday and Maldacena. In this last limit, the periodic potential becomes a series of deep wells each related to a light-like segment. Small corrections are described by a tight-binding approximation. In the circular limit they are well approximated by an expansion developed by A. Dekel. In the particular case of no umbilical points they reduce to a previous solution proposed by J. Toledo. The construction works both in Euclidean and Minkowski signature of AdS 3.

  4. Minimal area surfaces dual to Wilson loops and the Mathieu equation

    CERN Document Server

    Huang, Changyu; Kruczenski, Martin

    2016-01-01

    The AdS/CFT correspondence relates Wilson loops in N=4 SYM to minimal area surfaces in $AdS_5\\times S^5$ space. Recently, a new approach to study minimal area surfaces in $AdS_3 \\subset AdS_5$ was discussed based on a Schroedinger equation with a periodic potential determined by the Schwarzian derivative of the shape of the Wilson loop. Here we use the Mathieu equation, a standard example of a periodic potential, to obtain a class of Wilson loops such that the area of the dual minimal area surface can be computed analytically in terms of eigenvalues of such equation. As opposed to previous examples, these minimal surfaces have an umbilical point (where the principal curvatures are equal) and are invariant under $\\lambda$-deformations. In various limits they reduce to the single and multiple wound circular Wilson loop and to the regular light-like polygons studied by Alday and Maldacena. In this last limit, the periodic potential becomes a series of deep wells each related to a light-like segment. Small correc...

  5. Condensation-Enhanced Self-Assembly as a Route to High Surface Area alpha-Aluminas

    NARCIS (Netherlands)

    Perez, Lidia Lopez; Zarubina, Valeriya; Heeres, Hero Jan; Melian-Cabrera, Ignacio

    2013-01-01

    High surface area nanosized alpha-alumina has been obtained by thermally treating a sol-gel-derived mesophase at 1200 degrees C; the mesophase was synthesized by a sol-gel route involving evaporation induced self-assembly (EISA) of a hydrolyzed gel from Al-tri-sec-butoxide in s-BuOH in the presence

  6. Determination of colloidal gold nanoparticle surface areas, concentrations, and sizes through quantitative ligand adsorption.

    Science.gov (United States)

    Gadogbe, Manuel; Ansar, Siyam M; He, Guoliang; Collier, Willard E; Rodriguez, Jose; Liu, Dong; Chu, I-Wei; Zhang, Dongmao

    2013-01-01

    Determination of the true surface areas, concentrations, and particle sizes of gold nanoparticles (AuNPs) is a challenging issue due to the nanoparticle morphological irregularity, surface roughness, and size distributions. A ligand adsorption-based technique for determining AuNP surface areas in solution is reported. Using a water-soluble, stable, and highly UV-vis active organothiol, 2-mercaptobenzimidazole (MBI), as the probe ligand, we demonstrated that the amount of ligand adsorbed is proportional to the AuNP surface area. The equivalent spherical AuNP sizes and concentrations were determined by combining the MBI adsorption measurement with Au(3+) quantification of aqua regia-digested AuNPs. The experimental results from the MBI adsorption method for a series of commercial colloidal AuNPs with nominal diameters of 10, 30, 50, and 90 nm were compared with those determined using dynamic light scattering, transmission electron microscopy, and localized surface plasmonic resonance methods. The ligand adsorption-based technique is highly reproducible and simple to implement. It only requires a UV-vis spectrophotometer for characterization of in-house-prepared AuNPs.

  7. Bet-hedging as an evolutionary game: the trade-off between egg size and number.

    Science.gov (United States)

    Olofsson, Helen; Ripa, Jörgen; Jonzén, Niclas

    2009-08-22

    Bet-hedging theory addresses how individuals should optimize fitness in varying and unpredictable environments by sacrificing mean fitness to decrease variation in fitness. So far, three main bet-hedging strategies have been described: conservative bet-hedging (play it safe), diversified bet-hedging (don't put all eggs in one basket) and adaptive coin flipping (choose a strategy at random from a fixed distribution). Within this context, we analyse the trade-off between many small eggs (or seeds) and few large, given an unpredictable environment. Our model is an extension of previous models and allows for any combination of the bet-hedging strategies mentioned above. In our individual-based model (accounting for both ecological and evolutionary forces), the optimal bet-hedging strategy is a combination of conservative and diversified bet-hedging and adaptive coin flipping, which means a variation in egg size both within clutches and between years. Hence, we show how phenotypic variation within a population, often assumed to be due to non-adaptive variation, instead can be the result of females having this mixed strategy. Our results provide a new perspective on bet-hedging and stress the importance of extreme events in life history evolution.

  8. Hydrochemistry of surface water and groundwater from a fractured carbonate aquifer in the Helwan area, Egypt

    Indian Academy of Sciences (India)

    Fathy A Abdalla; Traugott Scheytt

    2012-02-01

    Groundwater is an important water resource in the Helwan area, not only for drinking and agricultural purposes, but also because several famous mineral springs have their origin in the fractured carbonate aquifer of the region. The area is heavily populated with a high density of industrial activities which may pose a risk for groundwater and surface water resources. The groundwater and surface water quality was investigated as a basis for more future investigations. The results revealed highly variable water hydrochemistry. High values of chloride, sulphate, hardness and significant mineralization were detected under the industrial and high-density urban areas. High nitrate contents in the groundwater recorded in the southern part of the study area are probably due to irrigation and sewage infiltrations from the sewage treatment station. The presence of shale and marl intercalation within the fissured and cavernous limestone aquifer promotes the exchange reactions and dissolution processes. The groundwater type is sodium, sulphate, chloride reflecting more mineralized than surface water. The results also showed that water in the study area (except the Nile water) is unsuitable for drinking purposes, but it can be used for irrigation and industrial purposes with some restrictions.

  9. Contrasting characteristics of the surface energy balance between the urban and rural areas of Beijing

    Science.gov (United States)

    Wang, Linlin; Gao, Zhiqiu; Miao, Shiguang; Guo, Xiaofeng; Sun, Ting; Liu, Maofeng; Li, Dan

    2015-04-01

    A direct comparison of urban and rural surface energy balances, as well as a variety of other variables including incoming shortwave/longwave radiation and aerosol optical depth, is conducted for the Beijing metropolitan area. The results indicate that, overall, the urban area receives a smaller amount of incoming shortwave radiation but a larger amount of incoming longwave radiation. However, comparisons in the aerosol optical depth and cloud fraction at the two locations suggest that neither aerosol optical depth nor cloud fraction alone can explain the difference in the incoming shortwave radiation. The urban-rural differences in the incoming longwave radiation are unlikely to be caused by the presence of more abundant greenhouse gases over the urban area, as suggested by some previous studies, given that water vapor is the most dominant greenhouse gas and precipitable water is found to be less in urban areas. The higher incoming longwave radiation observed over the urban area is mostly likely due to the higher temperatures of the ambient air. The urban area is also found to always produce higher sensible heat fluxes and lower latent heat fluxes in the growing season. Furthermore, the urban area is associated with a larger amount of available energy (the sum of sensible and latent heat fluxes) than the rural area, except in May and October when evapotranspiration in the rural area significantly exceeds that in the urban area. This study provides observational evidence of urban-rural contrasts in relevant energy-balance components that plausibly arise from urban-rural differences in atmospheric and land-surface conditions.

  10. A Three-Dimensional Enormous Surface Area Aluminum Microneedle Array with Nanoporous Structure

    Directory of Open Access Journals (Sweden)

    Po Chun Chen

    2013-01-01

    Full Text Available We proposed fabricating an aluminum microneedle array with a nanochannel structure on the surface by combining micromachining, electrolyte polishing, and anodization methods. The microneedle array provides a three-dimensional (3D structure that possesses several hundred times more surface area than a traditional nanochannel template. Therefore, the microneedle array can potentially be used in many technology applications. This 3D microneedle array device can not only be used for painless injection or extraction, but also for storage, highly sensitive detection, drug delivery, and microelectrodes. From the calculation we made, the microneedle array not only increases surface area, but also enlarges the capacity of the device. Therefore, the microneedle array can further be used on many detecting, storing, or drug delivering applications.

  11. Potential areas for the near surface disposal of radioactive waste in Pahang

    Science.gov (United States)

    Harun, Nazran; Yaacob, Wan Zuhairi Wan; Simon, Norbert

    2016-11-01

    Radioactive material has been used in Malaysia since the 1960's. The low level radioactive wastes are generated every year and stored in Nuclear Malaysia. The storage capacities are expected to reach its maximum capacity by the year 2025. Disposal of the radioactive waste is considered as one of the best options for future radioactive and nuclear material generated in Malaysia, hence the necessary site selection. The selection process used the IAEA document as the main reference, supported by site selection procedure applied by various countries. ArcGIS software was used to simulate the selection of the near surface radioactive waste disposal. This paper suggested the best four potential areas for the near surface radioactive waste disposal in Pahang state, Malaysia, the Sg. Lembing, Gambang, Felda Lepar Utara and Cheneh areas. These areas are located within 100 km from the potential radioactive waste producer (Lynas).

  12. Comparison of deposited surface area of airborne ultrafine particles generated from two welding processes.

    Science.gov (United States)

    Gomes, J F; Albuquerque, P C; Miranda, Rosa M; Santos, Telmo G; Vieira, M T

    2012-09-01

    This article describes work performed on the assessment of the levels of airborne ultrafine particles emitted in two welding processes metal-active gas (MAG) of carbon steel and friction-stir welding (FSW) of aluminium in terms of deposited area in alveolar tract of the lung using a nanoparticle surface area monitor analyser. The obtained results showed the dependence from process parameters on emitted ultrafine particles and clearly demonstrated the presence of ultrafine particles, when compared with background levels. The obtained results showed that the process that results on the lower levels of alveolar-deposited surface area is FSW, unlike MAG. Nevertheless, all the tested processes resulted in important doses of ultrafine particles that are to be deposited in the human lung of exposed workers.

  13. High surface area stainless steel brushes as cathodes in microbial electrolysis cells.

    Science.gov (United States)

    Call, Douglas F; Merrill, Matthew D; Logan, Bruce E

    2009-03-15

    Microbial electrolysis cells (MECs) are an efficient technology for generating hydrogen gas from organic matter, but alternatives to precious metals are needed for cathode catalysts. We show here that high surface area stainless steel brush cathodes produce hydrogen at rates and efficiencies similar to those achieved with platinum-catalyzed carbon cloth cathodes in single-chamber MECs. Using a stainless steel brush cathode with a specific surface area of 810 m2/m3, hydrogen was produced at a rate of 1.7 +/- 0.1 m3-H2/m3-d (current density of 188 +/- 10 A/m3) at an applied voltage of 0.6 V. The energy efficiency relative to the electrical energy input was 221 +/- 8%, and the overall energy efficiency was 78 +/- 5% based on both electrical energy and substrate utilization. These values compare well to previous results obtained using platinum on flat carbon cathodes in a similar system. Reducing the cathode surface area by 75% decreased performance from 91 +/- 3 A/m3 to 78 +/- 4 A/m3. A brush cathode with graphite instead of stainless steel and a specific surface area of 4600 m2/m3 generated substantially less current (1.7 +/- 0.0 A/m3), and a flat stainless steel cathode (25 m2/m3) produced 64 +/- 1 A/m3, demonstrating that both the stainless steel and the large surface area contributed to high current densities. Linear sweep voltammetry showed that the stainless steel brush cathodes both reduced the overpotential needed for hydrogen evolution and exhibited a decrease in overpotential over time as a result of activation. These results demonstrate for the first time that hydrogen production can be achieved at rates comparable to those with precious metal catalysts in MECs without the need for expensive cathodes.

  14. Regional brain differences in cortical thickness, surface area and subcortical volume in individuals with Williams syndrome.

    Directory of Open Access Journals (Sweden)

    Shashwath A Meda

    Full Text Available Williams syndrome (WS is a rare genetic neurodevelopmental disorder characterized by increased non-social anxiety, sensitivity to sounds and hypersociability. Previous studies have reported contradictory findings with regard to regional brain variation in WS, relying on only one type of morphological measure (usually volume in each study. The present study aims to contribute to this body of literature and perhaps elucidate some of these discrepancies by examining concurrent measures of cortical thickness, surface area and subcortical volume between WS subjects and typically-developing (TD controls. High resolution MRI scans were obtained on 31 WS subjects and 50 typically developing control subjects. We derived quantitative regional estimates of cortical thickness, cortical surface area, and subcortical volume using FreeSurfer software. We evaluated between-group ROI differences while controlling for total intracranial volume. In post-hoc exploratory analyses within the WS group, we tested for correlations between regional brain variation and Beck Anxiety Inventory scores. Consistent with our hypothesis, we detected complex patterns of between-group cortical variation, which included lower surface area in combination with greater thickness in the following cortical regions: post central gyrus, cuneus, lateral orbitofrontal cortex and lingual gyrus. Additional cortical regions showed between-group differences in one (but not both morphological measures. Subcortical volume was lower in the basal ganglia and the hippocampus in WS versus TD controls. Exploratory correlations revealed that anxiety scores were negatively correlated with gray matter surface area in insula, OFC, rostral middle frontal, superior temporal and lingual gyrus. Our results were consistent with previous reports showing structural alterations in regions supporting the socio-affective and visuospatial impairments in WS. However, we also were able to effectively capture novel and

  15. Regional brain differences in cortical thickness, surface area and subcortical volume in individuals with Williams syndrome.

    Science.gov (United States)

    Meda, Shashwath A; Pryweller, Jennifer R; Thornton-Wells, Tricia A

    2012-01-01

    Williams syndrome (WS) is a rare genetic neurodevelopmental disorder characterized by increased non-social anxiety, sensitivity to sounds and hypersociability. Previous studies have reported contradictory findings with regard to regional brain variation in WS, relying on only one type of morphological measure (usually volume) in each study. The present study aims to contribute to this body of literature and perhaps elucidate some of these discrepancies by examining concurrent measures of cortical thickness, surface area and subcortical volume between WS subjects and typically-developing (TD) controls. High resolution MRI scans were obtained on 31 WS subjects and 50 typically developing control subjects. We derived quantitative regional estimates of cortical thickness, cortical surface area, and subcortical volume using FreeSurfer software. We evaluated between-group ROI differences while controlling for total intracranial volume. In post-hoc exploratory analyses within the WS group, we tested for correlations between regional brain variation and Beck Anxiety Inventory scores. Consistent with our hypothesis, we detected complex patterns of between-group cortical variation, which included lower surface area in combination with greater thickness in the following cortical regions: post central gyrus, cuneus, lateral orbitofrontal cortex and lingual gyrus. Additional cortical regions showed between-group differences in one (but not both) morphological measures. Subcortical volume was lower in the basal ganglia and the hippocampus in WS versus TD controls. Exploratory correlations revealed that anxiety scores were negatively correlated with gray matter surface area in insula, OFC, rostral middle frontal, superior temporal and lingual gyrus. Our results were consistent with previous reports showing structural alterations in regions supporting the socio-affective and visuospatial impairments in WS. However, we also were able to effectively capture novel and complex

  16. Bromodomain and extra-terminal (BET) family proteins: New therapeutic targets in major diseases

    Indian Academy of Sciences (India)

    Balasundaram Padmanabhan; Shruti Mathur; Manjula Ramu; Shailesh Tripathi

    2016-06-01

    The bromodomains and extra-terminal domain (BET) family proteins recognize acetylated chromatin through their bromodomains (BDs) and helps in regulating gene expression. BDs are chromatin ‘readers’; by interacting with acetylated lysines on the histone tails, they recruit chromatin-regulating proteins on the promoter region to regulate gene expression and repression. Extensive efforts have been employed by the scientific communities worldwide, to identify and develop potential inhibitors of BET family BDs to regulate protein expression by inhibiting acetylated histone (H3/H4) interactions. Several small molecule inhibitors have been reported, which not only have high affinity, but also have high specificity to BET BDs. These developments make BET family proteins to be an important therapeutic targets, for major diseases such as cancer, neurological disorders, obesity and inflammation. Here, we review and discuss the structural biology of BET family BDs and their applications in major diseases.

  17. Investigation on large-area fabrication of vivid shark skin with superior surface functions

    Science.gov (United States)

    Chen, Huawei; Zhang, Xin; Ma, Lingxi; Che, Da; Zhang, Deyuan; Sudarshan, T. S.

    2014-10-01

    Shark skin has attracted worldwide attention because of its superior drag reduction, antifouling performance induced from its unique surface morphology. Although the vivid shark skin has been fabricated by a bio-replicated micro-imprinting approach in previous studies and superior drag reduction effect has been validated in water tunnel, continuous large-area fabrication is still an obstacle to wide apply. In this paper, one novel bio-replication coating technology is proposed for large-area transfer of shark skin based on rapid UV curable paint. Apart from design of coating system, bio-replication accuracy of surface morphology was validated about 97% by comparison between shark skin template and coating surface morphology. Finally, the drag reduction and anti-fouling function of coating surface were tested in water tunnel and open algae pond respectively. Drag reduction rate of coating surface was validated about 12% higher and anti-fouling was proved to about hundred times ameliorate, all of which are more excellent than simple 2D riblet surface.

  18. BetOnMath azzardo e matematica a scuola

    CERN Document Server

    Andrà, Chiara; Verani, Marco

    2016-01-01

    Il libro ha origine dall'attività svolta durante il progetto "BetOnMath", un'esperienza di Matematica Civile finalizzata alla prevenzione dell'abuso di gioco d'azzardo tra gli studenti della scuola secondaria di secondo grado attraverso un insegnamento innovativo della matematica. In particolare, durante il progetto gli autori del libro hanno sviluppato un percorso didattico modulare sulla matematica del gioco d'azzardo che gli insegnanti di matematica delle scuole secondarie possono utilizzare sia per introdurre gli strumenti di base del calcolo delle probabilità sia per sensibilizzare sui rischi legati al gioco d'azzardo. Il libro descrive i pilastri metodologici e concettuali che hanno guidato la concezione e dato forma al percorso didattico, ovvero la centralità del ruolo dell'insegnante, l'uso dei simulatori di gioco, l'importanza delle attività di gruppo e il ruolo delle emozioni nell'affrontare e comprendere nuovi concetti matematici. Nel libro, ciascuno di questi pilastri è trattato sia mediante ...

  19. The balloon-borne electron telescope with scintillating fibers (BETS)

    CERN Document Server

    Torii, S; Tateyama, N; Yoshida, K; Ouchi, Y; Yamagami, T; Saitô, Y; Murakami, H; Kobayashi, T; Komori, Y; Kasahara, K; Yuda, T; Nishimura, J

    2000-01-01

    we describe a new detector system developed for high-altitude balloon flights to observe the cosmic-ray electrons above 10 GeV. The balloon borne electron telescope with Scintillating (BETS) fibers instrument is an imaging calorimeter which is capable of selecting electrons against the large background of protons. The calorimeter is composed of a sandwich of scintillating optical-fiber belts and lead plates with a combination of three plastic scintillators for the shower trigger. The total thickness of lead is 40 mm (~7.1 r.l.) and the number of fiber belts is nine. In each belt, alternating layers are oriented in orthogonal (x and y) directions. Two sets of an intensified CCD camera are adopted for read-out of the scintillating fibers in the x and y direction, respectively. The accelerator beam tests were carried out to study the performance of detector for electrons in 1996 and for protons in 1997 at CERN-SPS. The instrument was successfully flown aboard high-altitude balloon in 1997 and 1998. It is demonst...

  20. Betting on Illusory Patterns: Probability Matching in Habitual Gamblers.

    Science.gov (United States)

    Gaissmaier, Wolfgang; Wilke, Andreas; Scheibehenne, Benjamin; McCanney, Paige; Barrett, H Clark

    2016-03-01

    Why do people gamble? A large body of research suggests that cognitive distortions play an important role in pathological gambling. Many of these distortions are specific cases of a more general misperception of randomness, specifically of an illusory perception of patterns in random sequences. In this article, we provide further evidence for the assumption that gamblers are particularly prone to perceiving illusory patterns. In particular, we compared habitual gamblers to a matched sample of community members with regard to how much they exhibit the choice anomaly 'probability matching'. Probability matching describes the tendency to match response proportions to outcome probabilities when predicting binary outcomes. It leads to a lower expected accuracy than the maximizing strategy of predicting the most likely event on each trial. Previous research has shown that an illusory perception of patterns in random sequences fuels probability matching. So does impulsivity, which is also reported to be higher in gamblers. We therefore hypothesized that gamblers will exhibit more probability matching than non-gamblers, which was confirmed in a controlled laboratory experiment. Additionally, gamblers scored much lower than community members on the cognitive reflection task, which indicates higher impulsivity. This difference could account for the difference in probability matching between the samples. These results suggest that gamblers are more willing to bet impulsively on perceived illusory patterns.

  1. Impact of industrial wastewater disposal on surface water bodies in Mostord area north Greater Cairo

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The studied area (Shoubra El-Khima, Bahteem and Mostorod) lies in the industrial area north of Greater Cairo. The area suffers from several environmental problems such as sewage and disposal of pollutants from the surrounding factories into the surface water pathways in the area. Water samples were collected seasonally from different waterways found in the area, domestic and or industrial liquid wastes from 12 discharge tubes of different factories (as a point source of pollution). Chemical characteristics of different water samples and its heavy metals content were determined using ion coupled plasma technique (ICP). Results indicate that industrial and domestic wastewater samples contain several toxic levels of tested heavy metals (Cd, Co, Pb and Ni) which have a serious impact on surface waterways in the area.Shebin El-Qanater collector drain samples exhibited the highest levels of Cd, Co, Pb and Ni compared to other tested water bodies Mostorod collector drain samples showed the highest levels of Zn and Cu. Industrial effluent samples collected from Cairo Company for Fabric industry had the highest amounts of total Zn Cu, Cd, Co and Pb, while Delta steel company discharges the highest amounts of total Fe and Mn. Al-Ahleya Plastic Company discharges the highest amounts of total-Ni. Generally, it is necessary to impose the environmental laws and its regulation regarding the industrial wastewater treatments and disposals to minimize the risk of the adverse effects of these pollutants.

  2. Photocatalytic Activity in CH3CN Related to the Surface Properties of TiO2 Powders Prepared by Sol-Gel Method

    Directory of Open Access Journals (Sweden)

    Marta Bettoni

    2009-01-01

    Full Text Available Some TiO2 powders, prepared from titanium(IVtetraisopropoxide by the sol-gel method and thermally treated between 100 and 1000∘C, have been characterized by X-ray powder diffraction and by nitrogen adsorption and desorption at 77 K to calculate the BET-specific surface area, from which the micropore volume and the external surface area can be derived. The photocatalytic activity (ka of the above powders has been evaluated considering the TiO2-sensitized photo-oxidation of 4-methoxybenzyl alcohol in CH3CN as the test reaction. The decrease of ka have been related to the decrease of the BET surface area, the micropore volume, and the external surface area of the TiO2 powders, but a satisfactory linear correlation is observed only for the last superficial parameter.

  3. The major birch pollen allergen Bet v 1 induces different responses in dendritic cells of birch pollen allergic and healthy individuals.

    Directory of Open Access Journals (Sweden)

    Ursula Smole

    Full Text Available Dendritic cells play a fundamental role in shaping the immune response to allergens. The events that lead to allergic sensitization or tolerance induction during the interaction of the major birch pollen allergen Bet v 1 and dendritic cells are not very well studied. Here, we analyzed the uptake of Bet v 1 and the cross-reactive celery allergen Api g 1 by immature monocyte-derived dendritic cells (iMoDCs of allergic and normal donors. In addition, we characterized the allergen-triggered intracellular signaling and transcriptional events. Uptake kinetics, competitive binding, and internalization pathways of labeled allergens by iMoDCs were visualized by live-cell imaging. Surface-bound IgE was detected by immunofluorescence microscopy and flow cytometry. Allergen- and IgE-induced gene expression of early growth response genes and Th1 and Th2 related cytokines and chemokines were analyzed by real-time PCR. Phosporylation of signaling kinases was analyzed by Western blot. Internalization of Bet v 1 by iMoDCs of both donor groups, likely by receptor-mediated caveolar endocytosis, followed similar kinetics. Bet v 1 outcompeted Api g 1 in cell surface binding and uptake. MoDCs of allergic and healthy donors displayed surface-bound IgE and showed a pronounced upregulation of Th2 cytokine- and NFκB-dependent genes upon non-specific Fcε receptor cross-linking. In contrast to these IgE-mediated responses, Bet v 1-stimulation increased transcript levels of the Th2 cytokines IL-4 and IL-13 but not of NFκB-related genes in MoDCs of BP allergic donors. Cells of healthy donors were either unresponsive or showed elevated mRNA levels of Th1-promoting chemokines. Moreover, Bet v 1 was able to induce Erk1/2 and p38 MAPK activation in BP allergics but only a slight p38 activation in normal donors. In conclusion, our data indicate that Bet v 1 favors the activation of a Th2 program only in DCs of BP allergic individuals.

  4. Develop and test a solvent accessible surface area-based model in conformational entropy calculations.

    Science.gov (United States)

    Wang, Junmei; Hou, Tingjun

    2012-05-25

    It is of great interest in modern drug design to accurately calculate the free energies of protein-ligand or nucleic acid-ligand binding. MM-PBSA (molecular mechanics Poisson-Boltzmann surface area) and MM-GBSA (molecular mechanics generalized Born surface area) have gained popularity in this field. For both methods, the conformational entropy, which is usually calculated through normal-mode analysis (NMA), is needed to calculate the absolute binding free energies. Unfortunately, NMA is computationally demanding and becomes a bottleneck of the MM-PB/GBSA-NMA methods. In this work, we have developed a fast approach to estimate the conformational entropy based upon solvent accessible surface area calculations. In our approach, the conformational entropy of a molecule, S, can be obtained by summing up the contributions of all atoms, no matter they are buried or exposed. Each atom has two types of surface areas, solvent accessible surface area (SAS) and buried SAS (BSAS). The two types of surface areas are weighted to estimate the contribution of an atom to S. Atoms having the same atom type share the same weight and a general parameter k is applied to balance the contributions of the two types of surface areas. This entropy model was parametrized using a large set of small molecules for which their conformational entropies were calculated at the B3LYP/6-31G* level taking the solvent effect into account. The weighted solvent accessible surface area (WSAS) model was extensively evaluated in three tests. For convenience, TS values, the product of temperature T and conformational entropy S, were calculated in those tests. T was always set to 298.15 K through the text. First of all, good correlations were achieved between WSAS TS and NMA TS for 44 protein or nucleic acid systems sampled with molecular dynamics simulations (10 snapshots were collected for postentropy calculations): the mean correlation coefficient squares (R²) was 0.56. As to the 20 complexes, the TS

  5. Spontaneous Emulsification of a Metal Drop Immersed in Slag Due to Dephosphorization: Surface Area Quantification

    Science.gov (United States)

    Assis, Andre N.; Warnett, Jason; Spooner, Stephen; Fruehan, Richard J.; Williams, Mark A.; Sridhar, Seetharaman

    2015-04-01

    When a chemical reaction occurs between two immiscible liquids, mass transfer is continuously taking place at the liquid-liquid interface. Several studies have shown that if the species being exchanged between the two liquids are surface-active, a very pronounced decrease in interfacial tension can occur which can lead to a phenomenon called spontaneous emulsification. In steelmaking, this behavior has been observed for several reactions that involve the transfer of impurities from molten steel to a molten-oxide slag but little quantification has been made. This work focuses on spontaneous emulsification due to the dephosphorization of a Fe-P drop immersed in a basic oxygen furnace type slag. An Au-image furnace attached to a confocal scanning laser microscope was used to rapidly heat and cool the samples at different times, and X-ray computerized tomography was used to perform the surface area calculations of the samples where the slag/steel reaction was allowed to occur for distinct times. The results show that the surface area of the metal drop rapidly increases by over one order of magnitude during the first 60 seconds of the reaction while the chemical reaction is occurring at a fast rate. Once the reaction slows down, approximately after 60 seconds, the droplets start to coalesce back together minimizing the surface area and returning to a geometry close to its equilibrium shape.

  6. Effective grain surface area in the formation of molecular hydrogen in interstellar clouds

    CERN Document Server

    Chakrabarti, Sandip Kumar; Acharyya, Kinsuk; Chakrabarti, Sonali

    2008-01-01

    In the interstellar clouds, molecular hydrogens are formed from atomic hydrogen on grain surfaces. An atomic hydrogen hops around till it finds another one with which it combines. This necessarily implies that the average recombination time, or equivalently, the effective grain surface area depends on the relative numbers of atomic hydrogen influx rate and the number of sites on the grain. Our aim is to discover this dependency. We perform a numerical simulation to study the recombination of hydrogen on grain surfaces in a variety of cloud conditions. We use a square lattice (with a periodic boundary condition) of various sizes on two types of grains, namely, amorphous carbon and olivine. We find that the steady state results of our simulation match very well with those obtained from a simpler analytical consideration provided the `effective' grain surface area is written as $\\sim S^{\\alpha}$, where, $S$ is the actual physical grain area and $\\alpha$ is a function of the flux of atomic hydrogen which is deter...

  7. Surface area and volume determination of subgingival calculus using laser fluorescence.

    Science.gov (United States)

    Shakibaie, Fardad; Walsh, Laurence J

    2014-03-01

    Visible red (655 nm) laser fluorescence (LF) devices are currently used for identifying deposits of subgingival calculus on the root surfaces of teeth during dental examination and treatment; however, it is not known how the fluorescence readings produced by commercially available LF systems correlate to the nature of the deposits. This laboratory study explored the correlation between LF digital readings and the surface area and volume of subgingival calculus deposits on teeth. A collection of 30 extracted human posterior teeth with various levels of subgingival deposits of calculus across 240 sites were used in a clinical simulation, with silicone impression material used to replicate periodontal soft tissues. The teeth were scored by two examiners by using three commercial LF systems (DIAGNOdent, DIAGNOdent Pen and KEY3). The silicone was removed, and the teeth were removed for photography at × 20 magnification under white or ultraviolet light. The surface area, thickness, and volume were calculated, and both linear least squares regression and nonlinear (Spearman's rank method) correlation coefficients were determined. Visible red LF digital readings showed better correlation to calculus volume than to surface area. Overall, the best performance was found for the KEY3 system (Spearman coefficient 0.59), compared to the Classic DIAGNOdent (0.56) and the DIAGNOdent Pen (0.49). These results indicate that while visible red LF systems vary somewhat in performance, their LF readings provide a useful estimation of the volume of subgingival calculus deposits present on teeth.

  8. Cortical Thickness, Surface Area and Subcortical Volume Differentially Contribute to Cognitive Heterogeneity in Parkinson's Disease.

    Directory of Open Access Journals (Sweden)

    Niels J H M Gerrits

    Full Text Available Parkinson's disease (PD is often associated with cognitive deficits, although their severity varies considerably between patients. Recently, we used voxel-based morphometry (VBM to show that individual differences in gray matter (GM volume relate to cognitive heterogeneity in PD. VBM does, however, not differentiate between cortical thickness (CTh and surface area (SA, which might be independently affected in PD. We therefore re-analyzed our cohort using the surface-based method FreeSurfer, and investigated (i CTh, SA, and (subcortical GM volume differences between 93 PD patients and 45 matched controls, and (ii the relation between these structural measures and cognitive performance on six neuropsychological tasks within the PD group. We found cortical thinning in PD patients in the left pericalcarine gyrus, extending to cuneus, precuneus and lingual areas and left inferior parietal cortex, bilateral rostral middle frontal cortex, and right cuneus, and increased cortical surface area in the left pars triangularis. Within the PD group, we found negative correlations between (i CTh of occipital areas and performance on a verbal memory task, (ii SA and volume of the frontal cortex and visuospatial memory performance, and, (iii volume of the right thalamus and scores on two verbal fluency tasks. Our primary findings illustrate that i CTh and SA are differentially affected in PD, and ii VBM and FreeSurfer yield non-overlapping results in an identical dataset. We argue that this discrepancy is due to technical differences and the subtlety of the PD-related structural changes.

  9. Safety analysis of stability of surface gas drainage boreholes above goaf areas

    Institute of Scientific and Technical Information of China (English)

    LIU Yu-zhou; LI Xiao-hong

    2007-01-01

    As longwall caving mining method prevails rapidly in China coal mines, amount of gas emission from longwall faces and goaf area increased significantly. Using traditional gas drainage methods, such as drilling upward holes to roof strata in tailgate or drilling inseam and cross-measure boreholes, could not meet methane drainage requirements in a gassy mine. The alternative is to drill boreholes from surface down to the longwall goaf area to drain the gas out. As soon as a coal seam is extracted out, the upper rock strata above the goaf start to collapse or become fractured depending upon the rock characteristics and the height above the coal seam. During overlying rock strata being fractured,boreholes in the area may be damaged due to ground movement after the passage of the longwall face. The sudden damage of a borehole may cause a longwall production halt or even a serious mine accident. A theoretical calculation of the stability of surface boreholes in mining affected area is introduced along with an example of determination of borehole and casing diameters is given for demonstration. By using this method for the drilling design, the damage of surface boreholes caused by excessive mining induced displacement can be effectively reduced if not totally avoided. Borehole and casing diameters as well as characteristics of filling materials can be determined using the proposed method by calculating the horizontal movement and vertical stain at different borehole depths.

  10. Natural and planted flora of the log mountain surface - mined demonstration area, Bell County, Kentucky

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, R.L. [Berea College, KY (United States); Wade, G.L. [USDA Forest Service, Burlington, VT (United States); Straw, R.A. [Univ. of Tennessee Plateau Experiment Station, Crossville, TN (United States)

    1996-12-31

    A descriptive study of the naturally invading and planted flora was conducted during 1984-1985 on a 14- and 21-year-old contour surface mine the 14.2 ha Log Mountain Demonstration Area (LMDA), in Bell County, Kentucky. Six habitats are designated from areas created from coal mining; the 1963 bench, 1970 bench, bench highwalls, mine outslopes, mine seeps, and coal haul-telephone microwave tower road. Twenty-four of 25 woody and herbaceous species (11 indigenous, 13 non-indigenous) have persisted from plantings by personnel of the Northeastern Forest Experiment Station, USDA Forest Service. We recommend 11 native and exotic woody and herbaceous species for planting on coal surface-mined areas. An annotated list of vascular plants comprises 360 taxa (286 indigenous, 74 non-indigenous) in 224 genera from 82 families. Taxa consist of 1 Lycopodiophyta, 1 Equisetophyta, 8 Polypodiophyta, 7 Pinophyta, and 343 Magnoliophyta. The most species-rich families are the Asteraceae (64), Poaceae (39), Fabaceae (20), Cyperaceae (16), Rosaceae (13), and Lamiaceae (11). A total of 155 Bell County distribution records were documented. Three threatened Kentucky species (Gentiana decora, Liparis loeselii, Silene ovata) were present in refugial habitats created by surface mining. The high species richness has resulted from native and naturalized invading species from the environs, native and exotic planted species, and species from the remnant seed bank. Forest vegetation is a complex mosaic of natural and semi-natural plant communities on the unplanted and planted areas of LMDA.

  11. Nanotechnological Advances in Catalytic Thin Films for Green Large-Area Surfaces

    Directory of Open Access Journals (Sweden)

    Suzan Biran Ay

    2015-01-01

    Full Text Available Large-area catalytic thin films offer great potential for green technology applications in order to save energy, combat pollution, and reduce global warming. These films, either embedded with nanoparticles, shaped with nanostructuring techniques, hybridized with other systems, or functionalized with bionanotechnological methods, can include many different surface properties including photocatalytic, antifouling, abrasion resistant and mechanically resistive, self-cleaning, antibacterial, hydrophobic, and oleophobic features. Thus, surface functionalization with such advanced structuring methods is of significance to increase the performance and wide usage of large-area thin film coatings specifically for environmental remediation. In this review, we focus on methods to increase the efficiency of catalytic reactions in thin film and hence improve the performance in relevant applications while eliminating high cost with the purpose of widespread usage. However, we also include the most recent hybrid architectures, which have potential to make a transformational change in surface applications as soon as high quality and large area production techniques are available. Hence, we present and discuss research studies regarding both organic and inorganic methods that are used to structure thin films that have potential for large-area and eco-friendly coatings.

  12. Small carpal bone surface area, a characteristic of Turner's syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Cleveland, R.H.; Done, S.; Correia, J.A.; Crawford, J.D.; Kushner, D.C.; Herman, T.E.

    1985-02-01

    An abnormality which has received little attention but may be easily recognized on radiographs of the hand of patients with Turner's syndrome is described. Eleven of thirty-one patients (35.5%) with Turner's syndrome were shown on radiographs of the hand to have a visually detectable smallness of the bone surface area of the carpus when compared to the area of the second through fifth metacarpals. Values for the ''C/M'' ratio (the area of the carpals divided by the area of the second through fifth metacarpals) were calculated for films of 31 individuals with gonadal dysgenesis and compared with those from bone age-matched films of seventy-six individuals with normal development of the hand and wrist. A consistent difference with minimal overlap was documented.

  13. Cortical thickness and surface area in neonates at high risk for schizophrenia.

    Science.gov (United States)

    Li, Gang; Wang, Li; Shi, Feng; Lyall, Amanda E; Ahn, Mihye; Peng, Ziwen; Zhu, Hongtu; Lin, Weili; Gilmore, John H; Shen, Dinggang

    2016-01-01

    Schizophrenia is a neurodevelopmental disorder associated with subtle abnormal cortical thickness and cortical surface area. However, it is unclear whether these abnormalities exist in neonates associated with genetic risk for schizophrenia. To this end, this preliminary study was conducted to identify possible abnormalities of cortical thickness and surface area in the high-genetic-risk neonates. Structural magnetic resonance images were acquired from offspring of mothers (N = 21) who had schizophrenia (N = 12) or schizoaffective disorder (N = 9), and also matched healthy neonates of mothers who were free of psychiatric illness (N = 26). Neonatal cortical surfaces were reconstructed and parcellated as regions of interest (ROIs), and cortical thickness for each vertex was computed as the shortest distance between the inner and outer surfaces. Comparisons were made for the average cortical thickness and total surface area in each of 68 cortical ROIs. After false discovery rate (FDR) correction, it was found that the female high-genetic-risk neonates had significantly thinner cortical thickness in the right lateral occipital cortex than the female control neonates. Before FDR correction, the high-genetic-risk neonates had significantly thinner cortex in the left transverse temporal gyrus, left banks of superior temporal sulcus, left lingual gyrus, right paracentral cortex, right posterior cingulate cortex, right temporal pole, and right lateral occipital cortex, compared with the control neonates. Before FDR correction, in comparison with control neonates, male high-risk neonates had significantly thicker cortex in the left frontal pole, left cuneus cortex, and left lateral occipital cortex; while female high-risk neonates had significantly thinner cortex in the bilateral paracentral, bilateral lateral occipital, left transverse temporal, left pars opercularis, right cuneus, and right posterior cingulate cortices. The high-risk neonates also had significantly

  14. Effect of particle surface area on ice active site densities retrieved from droplet freezing spectra

    Science.gov (United States)

    Beydoun, Hassan; Polen, Michael; Sullivan, Ryan C.

    2016-10-01

    Heterogeneous ice nucleation remains one of the outstanding problems in cloud physics and atmospheric science. Experimental challenges in properly simulating particle-induced freezing processes under atmospherically relevant conditions have largely contributed to the absence of a well-established parameterization of immersion freezing properties. Here, we formulate an ice active, surface-site-based stochastic model of heterogeneous freezing with the unique feature of invoking a continuum assumption on the ice nucleating activity (contact angle) of an aerosol particle's surface that requires no assumptions about the size or number of active sites. The result is a particle-specific property g that defines a distribution of local ice nucleation rates. Upon integration, this yields a full freezing probability function for an ice nucleating particle. Current cold plate droplet freezing measurements provide a valuable and inexpensive resource for studying the freezing properties of many atmospheric aerosol systems. We apply our g framework to explain the observed dependence of the freezing temperature of droplets in a cold plate on the concentration of the particle species investigated. Normalizing to the total particle mass or surface area present to derive the commonly used ice nuclei active surface (INAS) density (ns) often cannot account for the effects of particle concentration, yet concentration is typically varied to span a wider measurable freezing temperature range. A method based on determining what is denoted an ice nucleating species' specific critical surface area is presented and explains the concentration dependence as a result of increasing the variability in ice nucleating active sites between droplets. By applying this method to experimental droplet freezing data from four different systems, we demonstrate its ability to interpret immersion freezing temperature spectra of droplets containing variable particle concentrations. It is shown that general

  15. Body surface area determined by whole-body CT scanning: need for new formulae?

    DEFF Research Database (Denmark)

    Villa, Chiara; Primeau, Charlotte; Hesse, Ulrik;

    2017-01-01

    Calculation of the estimated body surface area (BSA) by body height and weight has been a challenge in the past centuries due to lack of a well-documented gold standard. More recently, available techniques such as 3D laser surface scanning and CT scanning may be expected to quantify the BSA...... in an easier and more accurate way. This study provides the first comparison between BSA obtained from post-mortem whole-body CT scans and BSA calculated by nine predictive formulae. The sample consisted of 54 male cadavers ranging from 20 to 87 years old. 3D reconstructions were generated from CT scans using...

  16. Impervious Surface Area Mapping using Landsat Imagery: Applications to Hydrology and Land Use Change Monitoring

    Science.gov (United States)

    Smith, A.; Goetz, S. J.; Mazzacato, M. E.; Jantz, C.; Wright, R.

    2002-12-01

    Impervious surfaces include rooftops, roads, parking lots and other areas that are impermeable to moisture. As the amount of built environment around urban areas has increased, it has been widely recognized that more impervious surface area (ISA) results in greater volume and intensity of stream flow, which can degrade stream health and require expensive modifications to flood control structures. Other effects include increased urban "heat island" influences and changes in local weather. If impervious areas could be accurately mapped using satellite imagery, it would provide valuable input to many applications, from hydrologic modeling to land use planning. We have developed a method to map subpixel ISA with Landsat Thematic Mapper (TM) imagery and classification - regression tree algorithms. This approach provides highly accurate (90+ percent) maps of ISA, but also permits estimation of the proportion of each cell occupied by impervious materials (between 0-100 percent). We report on a recently completed a map of ISA for the entire 163,000 km2 Chesapeake Bay watershed, a region of highly altered land cover and rapid land use change. We also report on the mapping of change patterns, indicated by ISA changes between 1986 - 2001, in an 18,000 km2 area centered on Baltimore - Washington, D.C. We review the methods, issues, technical challenges, results, accuracy, and advantages of this approach, and provide an overview of various applications for which the products are currently being used.

  17. How much global burned area can be forecast on seasonal time scales using sea surface temperatures?

    Science.gov (United States)

    Chen, Yang; Morton, Douglas C.; Andela, Niels; Giglio, Louis; Randerson, James T.

    2016-04-01

    Large-scale sea surface temperature (SST) patterns influence the interannual variability of burned area in many regions by means of climate controls on fuel continuity, amount, and moisture content. Some of the variability in burned area is predictable on seasonal timescales because fuel characteristics respond to the cumulative effects of climate prior to the onset of the fire season. Here we systematically evaluated the degree to which annual burned area from the Global Fire Emissions Database version 4 with small fires (GFED4s) can be predicted using SSTs from 14 different ocean regions. We found that about 48% of global burned area can be forecast with a correlation coefficient that is significant at a p climate index (OCI) 3 or more months prior to the month of peak burning. Continental regions where burned area had a higher degree of predictability included equatorial Asia, where 92% of the burned area exceeded the correlation threshold, and Central America, where 86% of the burned area exceeded this threshold. Pacific Ocean indices describing the El Niño-Southern Oscillation were more important than indices from other ocean basins, accounting for about 1/3 of the total predictable global burned area. A model that combined two indices from different oceans considerably improved model performance, suggesting that fires in many regions respond to forcing from more than one ocean basin. Using OCI—burned area relationships and a clustering algorithm, we identified 12 hotspot regions in which fires had a consistent response to SST patterns. Annual burned area in these regions can be predicted with moderate confidence levels, suggesting operational forecasts may be possible with the aim of improving ecosystem management.

  18. Substrate specificity and ion coupling in the Na+/betaine symporter BetP.

    Science.gov (United States)

    Perez, Camilo; Koshy, Caroline; Ressl, Susanne; Nicklisch, Sascha; Krämer, Reinhard; Ziegler, Christine

    2011-04-06

    BetP is an Na(+)-coupled betaine-specific transporter of the betaine-choline-carnitine (BCC) transporter family involved in the response to hyperosmotic stress. The crystal structure of BetP revealed an overall fold of two inverted structurally related repeats (LeuT-fold) that BetP shares with other sequence-unrelated Na(+)-coupled symporters. Numerous structures of LeuT-fold transporters in distinct conformational states have contributed substantially to our understanding of the alternating access mechanism of transport. Nevertheless, coupling of substrate and co-transported ion fluxes has not been structurally corroborated to the same extent. We converted BetP by a single-point mutation--glycine to aspartate--into an H(+)-coupled choline-specific transporter and solved the crystal structure of this mutant in complex with choline. The structure of BetP-G153D demonstrates a new inward-facing open conformation for BetP. Choline binding to a location close to the second, low-affinity sodium-binding site (Na2) of LeuT-fold transporters is facilitated by the introduced aspartate. Our data confirm the importance of a cation-binding site in BetP, playing a key role in a proposed molecular mechanism of Na(+) and H(+) coupling in BCC transporters.

  19. Pore structure and surface area of silica SBA-15: influence of washing and scale-up

    Directory of Open Access Journals (Sweden)

    Jörg P. Thielemann

    2011-02-01

    Full Text Available The removal of the surfactant (EO20PO70EO20 by washing before final calcination is a critical step in the synthesis of silica SBA-15. In contrast to washing with pure water or ethanol, washing with water and ethanol may, depending on the quantity of solvent used, alter the homogeneity and order of the pores, but also lead to an increase of the surface area of SBA-15. A reduction of solvent volume and a controlled washing protocol allow the synthesis of high surface area SBA-15 materials with a narrow monomodal pore size distribution. For larger batch sizes the influence of the quantity of solvent on the quality of the SBA-15 is reduced.

  20. Mapping of the cumulative β-ray dose on the ground surface surrounding the Fukushima area

    Science.gov (United States)

    Endo, Satoru; Kajimoto, Tsuyoshi; Tanaka, Kenichi; Nguyen, Thanh T.; Hayashi, Gohei; Imanaka, Tetsuji

    2015-01-01

    A large amount of the fission products released by the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident on 11 March 2011 was deposited in a wide area from Tohoku to northern Kanto. A map of the estimated cumulative β-ray dose (70 μm dose equivalent) on the soil surface for one year after the FDNPP accident has been prepared using previously reported calculation methods and the 2-km mesh survey data by MEXT. From this map of estimated dose, areas with a high cumulative β-ray dose on the soil surface for one year after the FDNPP accident were found to be located in the Akogi-Teshichiro to Akogi-Kunugidaira region in Namie Town, and in the southern Futaba Town to the northern Tomioka Town region. The highest estimated cumulative β-ray dose was 710 mSv for one year at Akogi-Teshichiro, Namie Town. PMID:26519736

  1. Effect of preparation surface area on the clinical outcome of full veneer crowns in dogs.

    Science.gov (United States)

    Riehl, Jessica; Soukup, Jason W; Collins, Caitlyn; Siverling, Sarah; Ploeg, Heidi-Lynn; Snyder, Christopher J

    2014-01-01

    Crown therapy is commonly used in veterinary medicine to provide support to teeth which have previously fractured, received root canal therapy, have significant wear, or experienced other detrimental removal of tooth substance. As with several aspects of veterinary medicine, many of the recommendations or guidelines for crown therapy originate from human dentistry, which are then transferred to veterinary patients. Due to the significant difference in the anatomy of teeth and function of the oral cavity between humans and dogs, these guidelines need to be studied to determine the appropriateness of their use in veterinary patients. This article evaluates the relationship between surface area of the preparation and clinical outcome of full veneer crown therapy of the canine tooth in dogs. Although there appeared to be a positive relationship between preparations with greater surface area and successful clinical outcome, it was not found to be statistically significant.

  2. Preparation and characterization of boron nitride/carbon fiber composite with high specific surface area

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yan; Fan, Mingwen [Wuhan Univ. (China). Key Laboratory for Oral Biomedical Engineering; Yuan, Songdong; Xiong, Kun; Hu, Kunpeng; Luo, Yi [Hubei Univ. of Technology, Wuhan (China). School of Chemistry and Chemical Engineering; Li, Dong [Hubei Univ. of Technology, Wuhan (China). School of Chemistry and Chemical Engineering; Oxford Univ. (United Kingdom). Chemistry Research Lab.

    2014-06-15

    Boron nitride can be used as a good catalyst carrier because of its high thermal conductivity and chemical stability. However, a high specific surface area of boron nitride is still desirable. In this work, a carbon fiber composite coated with boron nitride villous nano-film was prepared, and was also characterized by means of scanning electron microscopy, high resolution transmission electron microscopy, Fourier transform infrared spectroscopy, and Brunauer-Emmett-Teller analysis. The results indicated that the carbon fibers were covered by uniform villous boron nitride films whose thickness was about 150 - 200 nm. The specific surface area of the boron nitride/carbon fiber composite material was 96 m{sup 2} g{sup -1}, which was markedly improved compared with conventional boron nitride materials. (orig.)

  3. The Valley Bottom Extraction Tool (V-BET): A GIS tool for delineating valley bottoms across entire drainage networks

    Science.gov (United States)

    Gilbert, Jordan T.; Macfarlane, William W.; Wheaton, Joseph M.

    2016-12-01

    The shape, size and extent of a valley bottom dictates the form and function of the associated river or stream. Consequently, accurate, watershed-wide delineation of valley bottoms is increasingly recognized as a necessary component of watershed management. While many valley bottom delineation approaches exist, methods that can be effectively applied across entire drainage networks to produce reasonably accurate results are lacking. Most existing tools are designed to work using high resolution topography data (i.e. > 2 m resolution Digital Elevation Model (DEM)) and can only be applied over relatively short reach lengths due to computational or data availability limitations. When these precise mapping approaches are applied throughout drainage networks (i.e. 102-104 km), the computational techniques often either do not scale, or the algorithms perform inconsistently. Other tools that produce outputs at broader scale extents generally utilize coarser input topographic data to produce more poorly resolved valley bottom approximations. To fill this methodology gap and produce relatively accurate valley bottoms over large areas, we developed an algorithm that accepts terrain data from one to 10 m with slope and valley width parameters that scale based on drainage area, allowing for watershed-scale valley bottom delineation. We packaged this algorithm in the Valley Bottom Extraction Tool (V-BET) as an open-source ArcGIS toolbox for ease of use. To illustrate V-BET's scalability and test the tool's robustness across different physiographic settings, we delineated valley bottoms for the entire perennial drainage network of Utah as well as twelve watersheds across the interior Columbia River Basin (totaling 55,400 km) using 10 m DEMs. We found that even when driven with relatively coarse data (10 m DEMs), V-BET produced a relatively accurate approximation of valley bottoms across the entire watersheds of these diverse physiographic regions.

  4. Plaque Size Is Decreased but M1 Macrophage Polarization and Rupture Related Metalloproteinase Expression Are Maintained after Deleting T-Bet in ApoE Null Mice.

    Directory of Open Access Journals (Sweden)

    Aikaterini Tsaousi

    Full Text Available Thelper1 (Th1 lymphocytes have been previously implicated in atherosclerotic plaque growth but their role in plaque vulnerability to rupture is less clear. We investigated whether T-bet knockout that prevents Th1 lymphocyte differentiation modulates classical (M1 macrophage activation or production of matrix degrading metalloproteinases (MMPs and their tissue inhibitors, TIMPs.We studied the effect of T-bet deletion in apolipoproteinE (ApoE knockout mice fed a high fat diet (HFD or normal chow diet (ND. Transcript levels of M1/M2 macrophage polarization markers, selected MMPs and TIMPs were measured by RT-qPCR in macrophages isolated from subcutaneous granulomas or in whole aortae. Immunohistochemistry of aortic sinus (AS and brachiocephalic artery (BCA plaques was conducted to quantify protein expression of the same factors. Deletion of T-bet decreased mRNA for the M1 marker NOS-2 in granuloma macrophages but levels of M2 markers (CD206, arginase-1 and Ym-1, MMPs-2, -9, -12, -13, -14 and -19 or TIMPs-1 to -3 were unchanged. No mRNA differences were observed in aortic extracts from mice fed a HFD for 12 weeks. Moreover, AS and BCA plaques were similarly sized between genotypes, and had similar areas stained for NOS-2, COX-2, MMP-12 and MMP-14 proteins. T-bet deletion increased MMP-13, MMP-14 and arginase-1 in AS plaques. After 35 weeks of ND, T-bet deletion reduced the size of AS and BCA plaques but there were no differences in the percentage areas stained for M1 or M2 markers, MMPs-12, -13, -14, or TIMP-3.Absence of Th1 lymphocytes is associated with reduced plaque size in ApoE knockout mice fed a normal but not high fat diet. In either case, M1 macrophage polarization and expression of several MMPs related to plaque instability are either maintained or increased.

  5. Nanoporous ultra-high specific surface inorganic fibres

    Science.gov (United States)

    Kanehata, Masaki; Ding, Bin; Shiratori, Seimei

    2007-08-01

    Nanoporous inorganic (silica) nanofibres with ultra-high specific surface have been fabricated by electrospinning the blend solutions of poly(vinyl alcohol) (PVA) and colloidal silica nanoparticles, followed by selective removal of the PVA component. The configurations of the composite and inorganic nanofibres were investigated by changing the average silica particle diameters and the concentrations of colloidal silica particles in polymer solutions. After the removal of PVA by calcination, the fibre shape of pure silica particle assembly was maintained. The nanoporous silica fibres were assembled as a porous membrane with a high surface roughness. From the results of Brunauer-Emmett-Teller (BET) measurements, the BET surface area of inorganic silica nanofibrous membranes was increased with the decrease of the particle diameters. The membrane composed of silica particles with diameters of 15 nm showed the largest BET surface area of 270.3 m2 g-1 and total pore volume of 0.66 cm3 g-1. The physical absorption of methylene blue dye molecules by nanoporous silica membranes was examined using UV-vis spectrometry. Additionally, the porous silica membranes modified with fluoroalkylsilane showed super-hydrophobicity due to their porous structures.

  6. Nanoporous ultra-high specific surface inorganic fibres

    Energy Technology Data Exchange (ETDEWEB)

    Kanehata, Masaki [Faculty of Science and Technology, Keio University, Yokohama 223-8522 (Japan); Ding Bin [Fiber and Polymer Science, University of California, Davis, CA 95616 (United States); Shiratori, Seimei [Faculty of Science and Technology, Keio University, Yokohama 223-8522 (Japan)

    2007-08-08

    Nanoporous inorganic (silica) nanofibres with ultra-high specific surface have been fabricated by electrospinning the blend solutions of poly(vinyl alcohol) (PVA) and colloidal silica nanoparticles, followed by selective removal of the PVA component. The configurations of the composite and inorganic nanofibres were investigated by changing the average silica particle diameters and the concentrations of colloidal silica particles in polymer solutions. After the removal of PVA by calcination, the fibre shape of pure silica particle assembly was maintained. The nanoporous silica fibres were assembled as a porous membrane with a high surface roughness. From the results of Brunauer-Emmett-Teller (BET) measurements, the BET surface area of inorganic silica nanofibrous membranes was increased with the decrease of the particle diameters. The membrane composed of silica particles with diameters of 15 nm showed the largest BET surface area of 270.3 m{sup 2} g{sup -1} and total pore volume of 0.66 cm{sup 3} g{sup -1}. The physical absorption of methylene blue dye molecules by nanoporous silica membranes was examined using UV-vis spectrometry. Additionally, the porous silica membranes modified with fluoroalkylsilane showed super-hydrophobicity due to their porous structures.

  7. CuO/ZnO catalysts for methanol steam reforming: The role of the support polarity ratio and surface area

    OpenAIRE

    2015-01-01

    The effect of surface area and polarity ratio of ZnO support on the catalytic properties of CuO/ZnO catalyst for methanol steam reforming (MSR) are studied. The surface area of ZnO was varied changing the calcination temperature and its polarity ratio was modified using different Zn precursors, zinc acetate and zinc nitrate. It was found that the copper dispersion and copper surface area increase with the surface area of the ZnO support and the polarity ratio of ZnO strongly in...

  8. Combining Spectral and Texture Features Using Random Forest Algorithm: Extracting Impervious Surface Area in Wuhan

    Science.gov (United States)

    Shao, Zhenfeng; Zhang, Yuan; Zhang, Lei; Song, Yang; Peng, Minjun

    2016-06-01

    Impervious surface area (ISA) is one of the most important indicators of urban environments. At present, based on multi-resolution remote sensing images, numerous approaches have been proposed to extract impervious surface, using statistical estimation, sub-pixel classification and spectral mixture analysis method of sub-pixel analysis. Through these methods, impervious surfaces can be effectively applied to regional-scale planning and management. However, for the large scale region, high resolution remote sensing images can provide more details, and therefore they will be more conducive to analysis environmental monitoring and urban management. Since the purpose of this study is to map impervious surfaces more effectively, three classification algorithms (random forests, decision trees, and artificial neural networks) were tested for their ability to map impervious surface. Random forests outperformed the decision trees, and artificial neural networks in precision. Combining the spectral indices and texture, random forests is applied to impervious surface extraction with a producer's accuracy of 0.98, a user's accuracy of 0.97, and an overall accuracy of 0.98 and a kappa coefficient of 0.97.

  9. Dynamics of spider glue adhesion: effect of surface energy and contact area

    Science.gov (United States)

    Amarpuri, Gaurav; Chen, Yizhou; Blackledge, Todd; Dhinojwala, Ali

    Spider glue is a unique biological adhesive which is humidity responsive such that the adhesion continues to increase upto 100% relative humidity (RH) for some species. This is unlike synthetic adhesives that significantly drop in adhesion with an increase in humidity. However, most of adhesion data reported in literature have used clean hydrophilic glass substrate, unlike the hydrophobic, and charged insect cuticle surface that adheres to spider glue in nature. Previously, we have reported that the spider glue viscosity changes over five orders of magnitude with humidity. Here, we vary the surface energy and surface charge of the substrate to test the change in Larnioides cornutus spider glue adhesion with humidity. We find that an increase in both surface energy and surface charge density increases the droplet spreading and there exists an optimum droplet contact area where adhesion is maximized. Moreover, spider glue droplets act as reusable adhesive for low energy hydrophobic surface at the optimum humidity. These results explain why certain prey are caught more efficiently by spiders in their habitat. The mechanism by which spider species tune its glue adhesion for local prey capture can inspire new generation smart adhesives.

  10. Influence of reconstruction water-bearing levels on surface displacement of post-mining areas

    Science.gov (United States)

    Milczarek, Wojciech; Blachowski, Jan; Grzempowski, Piotr

    2014-05-01

    The phenomenon of secondary deformation characteristic of the post-mining areas is not sufficiently recognized. For ground surfaces phenomenon may be continuous or discontinuous. There is no sufficient information that describes behavior of the rock mass in the long term after end of exploitation. It is considered that this phenomenon is gradually disappears with end of exploitation. Reliable quantitative data comes only from the analysis of direct measurements in selected areas: geodetic and satellites measurements. Analyzing current situation of operating mines can be said that in the near years, more centers will limit the mining of coal mining. This will contribute to separation further of post-mining areas, in which will be required to maintaining a permanent monitoring and making predictions on the impact of ended exploitation of the rock mass surface. This will be particularly important for highly urbanized areas. This study used finite element method (FEM) to describe phenomenon of reconstruction water-bearing levels and its impact on displacement on the ground surface. It was assumed that significant factors that influence the occurrence and size of secondary deformations are: reconstruction of water-bearing levels in the prior drainer rock mass, size of past exploitation, spatial distribution of coal seams and geological and tectonic structure has been assumed. The transversally isotropic model of six elastic constants: E1 = E2, E3, ν = ν12, ν13, G12, G13 has been assumed to describe of rock mass in the numerical calculations. Geometrical models used in the numerical calculations have been developed using GIS tools. For the study two-dimensional and three-dimensional models characterized by different geological conditions and different configuration of mining data have been developed. The results obtained displacements of the ground surface for the period of mining activity has been verified with the results based on the Knothe theory. The results of

  11. n-Alkylamine-assisted preparation of a high surface area vanadyl phosphate/tetraethylorthosilicate nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, João Paulo L., E-mail: billbrujah@yahoo.com.br [Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP 14040-901 (Brazil); Zampronio, Elaine C.; Oliveira, Herenilton P. [Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP 14040-901 (Brazil)

    2013-02-15

    Graphical abstract: CuK{sub α} X-ray diffraction patterns of the VP, VPOc, VPOcT, VPOcT200 and VPOcT500. Highlights: ► TEOS and octylamine incorporation into the VP was achieved by expanding the lamellar. ► The specific surface area increased from 15 m{sup 2} g{sup −1} in VP to 237 m{sup 2} g{sup −1} in VPOcT. ► The VPOcT exhibited thermal resistance up to 200 °C in air. ► Upon thermal treatment up to 500 °C, the surface area increased to 838 m{sup 2} g{sup −1}. -- Abstract: We have developed a vanadyl phosphate/tetraethylorthosilicate (VPO/TEOS) nanocomposite comprised of silicate chains interleaved with VPO layers, prepared by using an n-alkylamines such as octylamine as the structure directing agent. The nanocomposites were synthesized by reacting amine-intercalated vanadyl phosphate with tetraethylorthosilicate via the soft chemistry approach. The synthetic procedure encompassed the exfoliation of the layered vanadyl phosphate as well as the reorganization of this exfoliated solid into a mesostructured lamellar phase with the same V–P–O connectivity as in the original matrix. TEOS incorporation into the vanadyl phosphate was achieved by expanding the lamellar structure with n-alkylamine (Δd = 13 Å with n-octylamine). The specific surface area increased from 15 m{sup 2} g{sup −1} in the vanadyl phosphate matrix to 237 m{sup 2} g{sup −1} in VPOcT, and the isotherm curves revealed the characteristic hysteresis of mesoporous materials. Upon thermal treatment up to 500 °C, the surface area increased to 837 m{sup 2} g{sup −1}, which is suitable for catalytic purposes.

  12. A simple and highly effective process for the preparation of activated carbons with high surface area

    Energy Technology Data Exchange (ETDEWEB)

    Li Ying, E-mail: liyingjlu@163.com [College of Chemistry, Jilin University, Changchun 130012 (China); Ding Xuefeng; Guo Yupeng; Wang Lili; Rong Chunguang; Qu Yuning; Ma Xiaoyu [College of Chemistry, Jilin University, Changchun 130012 (China); Wang Zichen, E-mail: wangzc@jlu.edu.cn [College of Chemistry, Jilin University, Changchun 130012 (China)

    2011-06-15

    Highlights: {yields} High surface area activated carbon can be prepared by rice husk H{sub 3}PO{sub 4} without pretreatment. {yields} The characteristics of the activated carbon were greatly influenced by post-processing method. {yields} The lower SiO{sub 2} content of the activated carbons, the higher pore volume the carbons had. {yields} Some silica in rice husk reacted with H{sub 3}PO{sub 4} to form SiP{sub 2}O{sub 7} which could be removed by post-process. - Abstract: Activated carbons with high surface area were prepared by phosphoric acid as activation agent and rice husks as precursors. It was found that the characteristics of the activated carbons were influenced not only by the preparation but also by the post-processing method. The high surface area of the activated carbons was prepared under the optimum condition (50% H{sub 3}PO{sub 4} with impregnation ratio of 5:1, activation temperature of 500 deg. C, activation time of 0.5 h, wash water temperature of 100 deg. C). SiO{sub 2} content could affect the surface area of activated carbons, either. The lower SiO{sub 2} content of the activated carbons, the higher pore volume the carbons had. The SiO{sub 2} content was 11.2% when used the optimum condition. The explanation was that silicon element in rice husks reacted with H{sub 3}PO{sub 4} to form silicon phosphate (SiP{sub 2}O{sub 7}), and it could be proved further by X-ray diffraction analysis, SiP{sub 2}O{sub 7} could be removed by post-process.

  13. A program to compute the area of an irregular polygon on a spheroidal surface

    Digital Repository Service at National Institute of Oceanography (India)

    Sivakholundu, K.M.; Prabaharan, N.

    for statistical evaluation of resources availability, etc. With the advent of computers, the represen- tation of boundaries is now e ciently handled in digital form. Hence the quantifications (such as dis- tance or area) are also desirable in the same form, i....e. digital representation and numerical solutions. The advantage of this technique lies in the ability to evaluate rapidly and precisely, the continuously varying factors like convergence, radii of curvature at close intervals on the curved surface...

  14. Role of Surface Area, Primary Particle Size, and Crystal Phase on Titanium Dioxide Nanoparticle Dispersion Properties

    Directory of Open Access Journals (Sweden)

    Suvachittanont Sirikalaya

    2011-01-01

    Full Text Available Abstract Characterizing nanoparticle dispersions and understanding the effect of parameters that alter dispersion properties are important for both environmental applications and toxicity investigations. The role of particle surface area, primary particle size, and crystal phase on TiO2 nanoparticle dispersion properties is reported. Hydrodynamic size, zeta potential, and isoelectric point (IEP of ten laboratory synthesized TiO2 samples, and one commercial Degussa TiO2 sample (P25 dispersed in different solutions were characterized. Solution ionic strength and pH affect titania dispersion properties. The effect of monovalent (NaCl and divalent (MgCl2 inert electrolytes on dispersion properties was quantified through their contribution to ionic strength. Increasing titania particle surface area resulted in a decrease in solution pH. At fixed pH, increasing the particle surface area enhanced the collision frequency between particles and led to a higher degree of agglomeration. In addition to the synthesis method, TiO2 isoelectric point was found to be dependent on particle size. As anatase TiO2 primary particle size increased from 6 nm to 104 nm, its IEP decreased from 6.0 to 3.8 that also results in changes in dispersion zeta potential and hydrodynamic size. In contrast to particle size, TiO2 nanoparticle IEP was found to be insensitive to particle crystal structure.

  15. Mass, surface area and number metrics in diesel occupational exposure assessment.

    Science.gov (United States)

    Ramachandran, Gurumurthy; Paulsen, Dwane; Watts, Winthrop; Kittelson, David

    2005-07-01

    While diesel aerosol exposure assessment has traditionally been based on the mass concentration metric, recent studies have suggested that particle number and surface area concentrations may be more health-relevant. In this study, we evaluated the exposures of three occupational groups-bus drivers, parking garage attendants, and bus mechanics-using the mass concentration of elemental carbon (EC) as well as surface area and number concentrations. These occupational groups are exposed to mixtures of diesel and gasoline exhaust on a regular basis in various ratios. The three groups had significantly different exposures to workshift TWA EC with the highest levels observed in the bus garage mechanics and the lowest levels in the parking ramp booth attendants. In terms of surface area, parking ramp attendants had significantly greater exposures than bus garage mechanics, who in turn had significantly greater exposures than bus drivers. In terms of number concentrations, the exposures of garage mechanics exceeded those of ramp booth attendants by a factor of 5-6. Depending on the exposure metric chosen, the three occupational groups had quite different exposure rankings. This illustrates the importance of the choice of exposure metric in epidemiological studies. If these three occupational groups were part of an epidemiological study, depending on the metric used, they may or may not be part of the same similarly exposed group (SEG). The exposure rankings (e.g., low, medium, or high) of the three groups also changes with the metric used. If the incorrect metric is used, significant misclassification errors may occur.

  16. Rippled area formed by surface plasmon polaritons upon femtosecond laser double-pulse irradiation of silicon.

    Science.gov (United States)

    Derrien, Thibault J-Y; Krüger, Jörg; Itina, Tatiana E; Höhm, Sandra; Rosenfeld, Arkadi; Bonse, Jörn

    2013-12-02

    The formation of near-wavelength laser-induced periodic surface structures (LIPSS) on silicon upon irradiation with sequences of Ti:sapphire femtosecond laser pulse pairs (pulse duration 150 fs, central wavelength 800 nm) is studied theoretically. For this purpose, the nonlinear generation of conduction band electrons in silicon and their relaxation is numerically calculated using a two-temperature model approach including intrapulse changes of optical properties, transport, diffusion and recombination effects. Following the idea that surface plasmon polaritons (SPP) can be excited when the material turns from semiconducting to metallic state, the "SPP active area" is calculated as function of fluence and double-pulse delay up to several picoseconds and compared to the experimentally observed rippled surface areas. Evidence is presented that multi-photon absorption explains the large increase of the rippled area for temporally overlapping pulses. For longer double-pulse delays, relevant relaxation processes are identified. The results demonstrate that femtosecond LIPSS on silicon are caused by the excitation of SPP and can be controlled by temporal pulse shaping.

  17. Effects of acid treatment on the clay palygorskite: XRD, surface area, morphological and chemical composition

    Energy Technology Data Exchange (ETDEWEB)

    Xavier, Katiane Cruz Magalhaes; Santos, Maria do Socorro Ferreira dos; Santos, Maria Rita Morais Chaves; Oliveira, Marilia Evelyn Rodrigues; Osajima, Josy Antevelli; Silva Filho, Edson Cavalcanti da [Universidade Federal do Piaui (UFPI), Teresina, PI (Brazil); Carvalho, Maria Wilma Nunes Cordeiro, E-mail: edsonfilho@ufpi.edu.br [Universidade Federal de Campina Grande (UFCG), PB (Brazil)

    2014-08-15

    The palygorskite is an aluminum-magnesium silicate that has a fibrous morphology. Their physicochemical characteristics are the result of high surface area, porosity and thermal resistance which make it an attractive adsorbent. Its adsorption capacity can be increased through chemical reactions and/or heat treatments. The objective of this work is to verify the effects of acid activation on the palygorskite, treated with HCl at 90 °C at concentrations of 2, 4 and 6 mol L{sup -1} in 2 and 4 hours, with clay/acid solution ratio 1 g 10 mL{sup -1} and characterized by techniques: XRF, XRD and surface area. A significant increase in specific surface area was observed in the sample treated with HCl at the concentration 6 mol L{sup -1}. The changes were more pronounced at stricter concentrations of acidity, with decreasing intensity of reflection of the clay indicated in the XRD. These changes were confirmed in the XRF with the leaching of some oxides and with increasing concentration of SiO{sub 2}. (author)

  18. Hierarchical porous carbon with ultrahigh surface area from corn leaf for high-performance supercapacitors application

    Science.gov (United States)

    Yang, Xiaoqing; Li, Chengfei; Chen, Yue

    2017-02-01

    A new class of hierarchical porous carbon (HPC) with ultrahigh surface area is successfully fabricated by carefully selecting biomass carbon precursors and activation reagent, through which corn leaf (CL) with natural well-defined macropore channels is used as the carbon precursor, and H3PO4 is used as the active agent by virtue of its pore-widening effect. The as-prepared CL-based HPC (CLHPC) with a H3PO4/semi-carbonized CL mass ratio of 2 (CLHPC-2) demonstrates the highest specific surface area of 2507 m2 g-1 donated by 28.3% of micropore and 71.6% of mesopore, while maintaining the channel-like macroporous structure derived from the well-defined natural structure in CL. The combination of the hierarchical porous structure and ultrahigh surface area enables rapid electrolyte diffusion and sufficient active sites for charge accumulation. As a result, CLHPC-2 exhibits excellent electrochemical performance, such as high specific capacitance of 230 F g-1 at the current density of 0.1 A g-1, excellent high-rate capability (retention of 91% from 0.1 to 5 A g-1), and good cycling stability (99% capacitance retention after 10 000 cycles).

  19. Synthesis of high surface area nanometer magnesia by solid-state chemical reaction

    Institute of Scientific and Technical Information of China (English)

    GUAN Hongbo; WANG Pei; ZHAO Biying; ZHU Yuexiang; XIE Youchang

    2007-01-01

    Nanometer MgO samples with high surface area,small crystal size and mesoporous texture were synthesized tion process accelerated the sintering of MgO,and MgO with calcining its precursor in flowing dry nitrogen at 520℃ for 4 h.The samples were characterized by X-ray diffraction,N2 adsorption,transmission electron microscopy,thermogravimetry,and differential thermal analysis.The as-prepared MgO was composed of nanocrystals with a size of about 4-5 nm and formed a wormhole-like porous structure.The MgO also had good thermal stability,and its surface areas remained at 357 and 153 m2.g-1 after calcination at 600 and 800℃ for 2 h,respectively.Compared with the MgO sample prepared by the precipitation method,MgO prepared by solid-state chemical reaction has uniform pore size distribution,surface area,and crystal size.The solid-state chemical method has the advantages of low cost,low pollution,and high yield,therefore it appears to be a promising method in the industrial manufacture of nanometer MgO.

  20. Mesoporous ZrO2 fibers with enhanced surface area and the application as recyclable absorbent

    Science.gov (United States)

    Yu, Zhichao; Liu, Benxue; Zhou, Haifeng; Feng, Cong; Wang, Xinqiang; Yuan, Kangkang; Gan, Xinzhu; Zhu, Luyi; Zhang, Guanghui; Xu, Dong

    2017-03-01

    Highly crystalline mesoporous zirconia fibers with high surface area have been prepared by the use of electrospinning combined with precursors method. The obtained precursor fibers were treated in water steam and directly in air at different temperature respectively. Compared with the direct calcination in air, the water steam cannot only promote the crystallization of ZrO2 but also effectively remove off the organics and prevent the pore structure collapse. Moreover, through adding hydrochloric acid to modify the solution pH value, the obtained t-ZrO2 fibers treated in water steam at 300 °C have high surface area and large pore volume of 232.70 m2 g-1 and 0.36 cm3 g-1. The formation mechanism of the mesostucture was studied and the schematic was represented. Compared with the previous reports of mesoporous ZrO2 fibers, the as-synthesized materials exhibited the high crystallinity, large surface area and the long-range order mesostructure.The adsorption of Congo red indicates that the samples have a high adsorption capacity of 103.46 mg g-1 and long-periodic repeated availability.

  1. Evapotranspiration and runoff from large land areas: Land surface hydrology for atmospheric general circulation models

    Science.gov (United States)

    Famiglietti, J. S.; Wood, Eric F.

    1993-01-01

    A land surface hydrology parameterization for use in atmospheric GCM's is presented. The parameterization incorporates subgrid scale variability in topography, soils, soil moisture and precipitation. The framework of the model is the statistical distribution of a topography-soils index, which controls the local water balance fluxes, and is therefore taken to represent the large land area. Spatially variable water balance fluxes are integrated with respect to the topography-soils index to yield our large topography-soils distribution, and interval responses are weighted by the probability of occurrence of the interval. Grid square averaged land surface fluxes result. The model functions independently as a macroscale water balance model. Runoff ratio and evapotranspiration efficiency parameterizations are derived and are shown to depend on the spatial variability of the above mentioned properties and processes, as well as the dynamics of land surface-atmosphere interactions.

  2. Growth of Hierarchically Structured High-Surface Area Alumina on FeCrAl Alloy Wires

    Directory of Open Access Journals (Sweden)

    Chandni Rallan

    2013-01-01

    Full Text Available The formation of metastable alumina phases due to the oxidation of commercial FeCrAl alloy wires (0.5 mm thickness at various temperatures and time periods has been examined. Samples were isothermally oxidised in air using a thermogravimetric analyzer (TGA. The morphology of the oxidised samples was analyzed using an Electronic Scanning Electron Microscope (ESEM and X-ray on the surface analysis was done using an Energy Dispersive X-Ray (EDX analyzer. The technique of X-Ray Diffraction (XRD was used to characterize the phase of the oxide growth. The entire study showed that it was possible to grow high-surface area gamma alumina on the FeCrAl alloy wire surfaces when isothermally oxidised above 800°C over several hours.

  3. Determination of the specific surface area of snow using ozonation of 1,1-diphenylethylene.

    Science.gov (United States)

    Ray, Debajyoti; Kurková, Romana; Hovorková, Ivana; Klán, Petr

    2011-12-01

    We measured the kinetics of ozonation reaction of 1,1-diphenylethylene (DPE) in artificial snow, produced by shock freezing of DPE aqueous solutions sprayed into liquid nitrogen. It was demonstrated that most of the reactant molecules are in direct (productive) contact with gaseous ozone, thus the technique produces snow with organic molecules largely ejected to the surface of snow grains. The kinetic data were used to evaluate the snow specific surface area (∼70 cm(2) g(-1)). This number is a measure of the availability of the molecules on the surface for chemical reaction with gaseous species. The experimental results were consistent with the Langmuir-Hinshelwood type reaction mechanism. DPE represents environmentally relevant compounds such as alkenes which can react with atmospheric ozone, and are relatively abundant in natural snow. For typical atmospheric ozone concentrations in polar areas (20 ppbv), we estimated that half-life of DPE on the surface of snow grains is ∼5 days at submonolayer coverages and -15 °C.

  4. The T-box Transcription Factor T-bet in Immunity and Autoimmunity

    Institute of Scientific and Technical Information of China (English)

    Stanford L. Peng

    2006-01-01

    The T-box transcription factor T-bet (Tbx21) has emerged as a key regulator of type 1-like immunity, playing critical roles in the establishment and/or maintenance of effector cell fates in T and B lymphocytes, as well as dendritic cells and natural killer cells. Several autoimmune diseases, especially those classically considered related to T helper 1 (Th1) immunity, appear to require T-bet, at least as judged in mouse models. This review summarizes a current understanding of T-bet's role in immunity, as well as its importance in autoimmunity, with implications for therapeutic intervention.

  5. The Bet v 1 fold: an ancient, versatile scaffold for binding of large, hydrophobic ligands

    Directory of Open Access Journals (Sweden)

    Breiteneder Heimo

    2008-10-01

    Full Text Available Abstract Background The major birch pollen allergen, Bet v 1, is a member of the ubiquitous PR-10 family of plant pathogenesis-related proteins. In recent years, a number of diverse plant proteins with low sequence similarity to Bet v 1 was identified. In addition, determination of the Bet v 1 structure revealed the existence of a large superfamily of structurally related proteins. In this study, we aimed to identify and classify all Bet v 1-related structures from the Protein Data Bank and all Bet v 1-related sequences from the Uniprot database. Results Structural comparisons of representative members of already known protein families structurally related to Bet v 1 with all entries of the Protein Data Bank yielded 47 structures with non-identical sequences. They were classified into eleven families, five of which were newly identified and not included in the Structural Classification of Proteins database release 1.71. The taxonomic distribution of these families extracted from the Pfam protein family database showed that members of the polyketide cyclase family and the activator of Hsp90 ATPase homologue 1 family were distributed among all three superkingdoms, while members of some bacterial families were confined to a small number of species. Comparison of ligand binding activities of Bet v 1-like superfamily members revealed that their functions were related to binding and metabolism of large, hydrophobic compounds such as lipids, hormones, and antibiotics. Phylogenetic relationships within the Bet v 1 family, defined as the group of proteins with significant sequence similarity to Bet v 1, were determined by aligning 264 Bet v 1-related sequences. A distance-based phylogenetic tree yielded a classification into 11 subfamilies, nine exclusively containing plant sequences and two subfamilies of bacterial proteins. Plant sequences included the pathogenesis-related proteins 10, the major latex proteins/ripening-related proteins subfamily, and

  6. Description of climate, surface hydrology, and near-surface hydrogeology. Preliminary site description. Forsmark area - version 1.2

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Per-Olof [Artesia Grundvattenkonsult AB, Stockholm (Sweden); Werner, Kent [SWECO VIAK AB/Golder Associates AB, Stockholm (Sweden); Bosson, Emma; Berglund, Sten [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Juston, John [DBE Sweden, Uppsala (Sweden)

    2005-06-15

    The Swedish Nuclear Fuel and Waste Management Company (SKB) is conducting site investigations at two different locations, the Forsmark and Simpevarp areas, with the objective of siting a geological repository for spent nuclear fuel. The results from the investigations at the sites are used as a basic input to the development of Site Descriptive Models (SDM). The SDM shall summarise the current state of knowledge of the site, and provide parameters and models to be used in further analyses within Safety Assessment, Repository Design and Environmental Impact Assessment. The present report is a background report describing the meteorological conditions and the modelling of surface hydrology and near-surface hydrogeology in support of the Forsmark version 1.2 SDM based on the data available in the Forsmark 1.2 'data freeze' (July 31, 2004). The groundwater is very shallow, with groundwater levels within one meter below ground as an annual mean for almost all groundwater monitoring wells. Also, the annual groundwater level amplitude is less than 1.5 m for most wells. The shallow groundwater levels mean that there is a strong interaction between evapotranspiration, soil moisture and groundwater. In the modelling, surface water and near-surface groundwater divides are assumed to coincide. The small-scale topography implies that many local, shallow groundwater flow systems are formed in the Quaternary deposits, overlaying more large-scale flow systems associated with groundwater flows at greater depths. Groundwater level time series from wells in till and bedrock within the same areas show a considerably higher groundwater level in the till than in the bedrock. The observed differences in levels are not fully consistent with the good hydraulic contact between overburden and bedrock indicated by the hydraulic tests in the Quaternary deposits. However, the relatively lower groundwater levels in the bedrock may be caused by the horizontal to sub-horizontal highly

  7. Influence of Al-oxide on pesticide sorption to woody biochars with different surface areas.

    Science.gov (United States)

    Shou, Jianxin; Dong, Huaping; Li, Jianfa; Zhong, Jiaxing; Li, Saijun; Lü, Jinhong; Li, Yimin

    2016-10-01

    Biochars' properties will change after application in soil due to the interactions with soil constituents, which would then impact the performance of biochars as soil amendment. For a better understanding on these interactions, two woody biochars of different surface areas (SA) were physically treated with aluminum oxide (Al-oxide) to investigate its potential influence on biochars' sorption property. Both the micropore area and mesopore (17∼500 Å in diameter) area of the low-SA biochar were enhanced by at least 1.5 times after treatment with Al-oxide, whereas the same treatment did not change the surface characteristics of the high-SA biochar due partly to its well-developed porosity. The enhanced sorption of the pesticide isoproturon to the Al-oxide-treated low-SA biochar was observed and is positively related to the increased mesopore area. The desorption hysteresis of pesticide from the low-SA biochar was strengthened because of more pesticide molecules entrapped in the expanded pores by Al-oxide. However, no obvious change of pesticide sorption to the high-SA biochar after Al-oxide treatment was observed, corresponding to its unchanged porosity. The results suggest that the influence of Al-oxide on the biochars' sorption property is dependent on their porosity. This study will provide valuable information on the use of biochars for reducing the bioavailability of pesticides.

  8. Measurement of surface emission flux rates for volatile organic compounds at Technical Area 54

    Energy Technology Data Exchange (ETDEWEB)

    Trujillo, V.; Morgenstern, M.; Krier, D. [Los Alamos National Lab., NM (United States); Gilkeson, R. [Weirich and Associates, Albuquerque, NM (United States)

    1998-06-01

    The survey described in this report was conducted to estimate the mass of volatile organic compounds venting to the atmosphere from active and inactive waste disposal sites at Technical Area 54. A large number of nonintrusive passive sample collection devices were placed on the ground surface for 72 hours to characterize an area of approximately 150 acres. Results provided an indication of the boundary location of the known volatile organic plume, plume constituents, and isolated high concentration areas. The data from this survey enhanced existing data from a limited number of monitor wells currently used for plume surveillance. Results indicate that the estimated mass emission to the atmosphere is orders of magnitude lower than what is considered a small flux rate at a spill site or a Resource Conservation and Recovery Act landfill and is far below the threshold limit established by the State of New Mexico as an air quality concern.

  9. Variation in the measurement of cranial volume and surface area using 3D laser scanning technology.

    Science.gov (United States)

    Sholts, Sabrina B; Wärmländer, Sebastian K T S; Flores, Louise M; Miller, Kevin W P; Walker, Phillip L

    2010-07-01

    Three-dimensional (3D) laser scanner models of human crania can be used for forensic facial reconstruction, and for obtaining craniometric data useful for estimating age, sex, and population affinity of unidentified human remains. However, the use of computer-generated measurements in a casework setting requires the measurement precision to be known. Here, we assess the repeatability and precision of cranial volume and surface area measurements using 3D laser scanner models created by different operators using different protocols for collecting and processing data. We report intraobserver measurement errors of 0.2% and interobserver errors of 2% of the total area and volume values, suggesting that observer-related errors do not pose major obstacles for sharing, combining, or comparing such measurements. Nevertheless, as no standardized procedure exists for area or volume measurements from 3D models, it is imperative to report the scanning and postscanning protocols employed when such measurements are conducted in a forensic setting.

  10. Optimizing parameter choice for FSL-Brain Extraction Tool (BET) on 3D T1 images in multiple sclerosis

    DEFF Research Database (Denmark)

    Popescu, Valeriu; Battaglini, M; Hoogstrate, W S;

    2012-01-01

    Brain atrophy studies often use FSL-BET (Brain Extraction Tool) as the first step of image processing. Default BET does not always give satisfactory results on 3DT1 MR images, which negatively impacts atrophy measurements. Finding the right alternative BET settings can be a difficult and time...

  11. Corrective Action Decision Document for Corrective Action Unit 417: Central Nevada Test Area Surface, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    U.S. Department of Energy Nevada Operations Office

    1999-04-02

    This Corrective Action Decision Document (CADD) identifies and rationalizes the U.S. Department of Energy, Nevada Operations Office's selection of a recommended corrective action alternative (CAA) appropriate to facilitate the closure of Corrective Action Unit (CAU) 417: Central Nevada Test Area Surface, Nevada, under the Federal Facility Agreement and Consent Order. Located in Hot Creek Valley in Nye County, Nevada, and consisting of three separate land withdrawal areas (UC-1, UC-3, and UC-4), CAU 417 is comprised of 34 corrective action sites (CASs) including 2 underground storage tanks, 5 septic systems, 8 shaker pad/cuttings disposal areas, 1 decontamination facility pit, 1 burn area, 1 scrap/trash dump, 1 outlier area, 8 housekeeping sites, and 16 mud pits. Four field events were conducted between September 1996 and June 1998 to complete a corrective action investigation indicating that the only contaminant of concern was total petroleum hydrocarbon (TPH) which was found in 18 of the CASs. A total of 1,028 samples were analyzed. During this investigation, a statistical approach was used to determine which depth intervals or layers inside individual mud pits and shaker pad areas were above the State action levels for the TPH. Other related field sampling activities (i.e., expedited site characterization methods, surface geophysical surveys, direct-push geophysical surveys, direct-push soil sampling, and rotosonic drilling located septic leachfields) were conducted in this four-phase investigation; however, no further contaminants of concern (COCs) were identified. During and after the investigation activities, several of the sites which had surface debris but no COCs were cleaned up as housekeeping sites, two septic tanks were closed in place, and two underground storage tanks were removed. The focus of this CADD was to identify CAAs which would promote the prevention or mitigation of human exposure to surface and subsurface soils with contaminant

  12. 煅烧高岭土的比表面积与吸油性能%Specific Surface Area and Oil Adsorption of Calcinated Kaolin Clay

    Institute of Scientific and Technical Information of China (English)

    孙涛; 陈洁渝; 周春宇; 雷新荣

    2013-01-01

    A washed kaolin clay was calcinated in the temperature range from 600 ℃ to 1 000 ℃. The microscopic morphology, the phase, the specific surface area and pore size distribution of the products were characterized by field emission scanning electron microscopy, X-ray diffraction and BET nitrogen adsorption measurement, respectively. The relationship between oil absorption and specific surface area was analyzed. The results show that the oil adsorption of calcinated kaolin clay with the smallest average pore size at 750 ℃ is the greatest (i.e., 80.272 g/100 g). The oil adsorption of calcinated kaolin clay became greater due to the larger specific surface area and the presence of the more concentrated micropore and mesopore in the pore distribution at the calcining temperature of < 800 ℃. The microporous occlusion of the kaolin clay occurred when calcinated at 800 ℃, causing the more concentrated mesopore and macropore in the pore distribution. As a result, the oil absorption reduced. The oil absorption of the calcinated kaolin clay was closely related to the specific surface area and the more concentrated micropore in the pore distribution.%以水洗高岭土为原料,在600~1 000℃,以50℃为间隔取点煅烧.通过场发射扫描电镜观察产品的微观形貌、X射线衍射仪分析产品的物相,并用BET物理吸附仪表征产品的比表面积和孔径分布,根据煅烧高岭土的微观形貌、物相组成、吸脱附等温线等,分析其比表面积与吸油性能的关系.结果表明:750℃的煅烧高岭土吸油值最高,为80.272 g/100g,此时煅烧高岭土的比表面积最大,孔径分布集中于微孔和中孔,平均孔径最小.煅烧温度低于800℃时,煅烧高岭土的孔径分布较集中于微孔和中孔,比表面积较大,吸油值较高;煅烧温度升高至800℃以后,高岭土发生烧结导致微孔闭塞,孔径分布向中孔和大孔集中,比表面积减小,吸油值较低.因而煅烧高岭土的吸油性

  13. The surface area of the placenta and hypertension in the offspring in later life

    Science.gov (United States)

    BARKER, DAVID J.P.; THORNBURG, KENT L.; OSMOND, CLIVE; KAJANTIE, EERO; ERIKSSON, JOHAN G.

    2012-01-01

    Hypertension is more common among people who had low birthweight. Birthweight depends on the mother’s body size and on the growth of the placenta. We studied a group of 2003 subjects, of whom 644 were being treated for hypertension. They were born during 1934–44 in a hospital that kept detailed records of maternal and placental size. Hypertension was associated with reduced placental weight and surface area. These associations were strongest in the offspring of mothers with below average height or low socioeconomic status. In people whose mothers had below average height (160 cm) the prevalence of hypertension fell from 38% if the placental area was 200 cm2 or less to 21% if the area was more than 320 cm2 (p=0.0007). In the offspring of tall, middle class mothers, who were likely to have been the best nourished, hypertension was predicted by large placental weight in relation to birthweight. The odds ratio rose from 1.0 if the ratio of placental weight to birthweight was 0.17 or less to 1.9 (95% confidence interval 0.8 to 5.0) if the ratio was more than 0.21 (p for trend =0.03). We conclude that the effects of placental area on hypertension depend on the mother’s nutritional state. Poor maternal nutrition may compound the adverse effects of small placental size. In better-nourished mothers the placental surface may expand to compensate for fetal undernutrition. Growth along the minor axis of the surface may be more nutritionally sensitive than growth along the major axis. PMID:19876839

  14. Evolution of the Specific Surface Area of Snow in a High Temperature Gradient Metamorphism

    Science.gov (United States)

    Wang, X.; Baker, I.

    2014-12-01

    The structural evolution of low-density snow under a high temperature gradient over a short period usually takes place in the surface layers during diurnal recrystallization or on a clear, cold night. To relate snow microstructures with their thermal properties, we combined X-ray computed microtomography (micro-CT) observations with numerical simulations. Different types of snow were tested over a large range of TGs (100 K m-1- 500 K m-1). The Specific Surface Area (SSA) was used to characterize the temperature gradient metamorphism (TGM). The magnitude of the temperature gradient and the initial snow type both influence the evolution of SSA. The SSA evolution under TGM was dominated by grain growth and the formation of complex surfaces. Fresh snow experienced a logarithmic decrease of SSA with time, a feature been observed previously by others [Calonne et al., 2014; Schneebeli and Sokratov, 2004; Taillandier et al., 2007]. However, for initial rounded and connected snow structures, the SSA will increase during TGM. Understanding the SSA increase is important in order to predict the enhanced uptake of chemical species by snow or increase in snow albedo. Calonne, N., F. Flin, C. Geindreau, B. Lesaffre, and S. Rolland du Roscoat (2014), Study of a temperature gradient metamorphism of snow from 3-D images: time evolution of microstructures, physical properties and their associated anisotropy, The Cryosphere Discussions, 8, 1407-1451, doi:10.5194/tcd-8-1407-2014. Schneebeli, M., and S. A. Sokratov (2004), Tomography of temperature gradient metamorphism of snow and associated changes in heat conductivity, Hydrological Processes, 18(18), 3655-3665, doi:10.1002/hyp.5800. Taillandier, A. S., F. Domine, W. R. Simpson, M. Sturm, and T. A. Douglas (2007), Rate of decrease of the specific surface area of dry snow: Isothermal and temperature gradient conditions, Journal of Geophysical Research: Earth Surface (2003-2012), 112(F3), doi: 10.1029/2006JF000514.

  15. Toward the Estimation of Surface Soil Moisture Content Using Geostationary Satellite Data over Sparsely Vegetated Area

    Directory of Open Access Journals (Sweden)

    Pei Leng

    2015-04-01

    Full Text Available Based on a novel bare surface soil moisture (SSM retrieval model developed from the synergistic use of the diurnal cycles of land surface temperature (LST and net surface shortwave radiation (NSSR (Leng et al. 2014. “Bare Surface Soil Moisture Retrieval from the Synergistic Use of Optical and Thermal Infrared Data”. International Journal of Remote Sensing 35: 988–1003., this paper mainly investigated the model’s capability to estimate SSM using geostationary satellite observations over vegetated area. Results from the simulated data primarily indicated that the previous bare SSM retrieval model is capable of estimating SSM in the low vegetation cover condition with fractional vegetation cover (FVC ranging from 0 to 0.3. In total, the simulated data from the Common Land Model (CoLM on 151 cloud-free days at three FLUXNET sites that with different climate patterns were used to describe SSM estimates with different underlying surfaces. The results showed a strong correlation between the estimated SSM and the simulated values, with a mean Root Mean Square Error (RMSE of 0.028 m3·m−3 and a coefficient of determination (R2 of 0.869. Moreover, diurnal cycles of LST and NSSR derived from the Meteosat Second Generation (MSG satellite data on 59 cloud-free days were utilized to estimate SSM in the REMEDHUS soil moisture network (Spain. In particular, determination of the model coefficients synchronously using satellite observations and SSM measurements was explored in detail in the cases where meteorological data were not available. A preliminary validation was implemented to verify the MSG pixel average SSM in the REMEDHUS area with the average SSM calculated from the site measurements. The results revealed a significant R2 of 0.595 and an RMSE of 0.021 m3·m−3.

  16. Visualization of Lake Mead Surface Area Changes from 1972 to 2009

    Directory of Open Access Journals (Sweden)

    David M. Atkinson

    2012-06-01

    Full Text Available For most of the last decade, the south-western portion of the United States has experienced a severe and enduring drought. This has caused serious concerns about water supply and management in the region. In this research, 30 orthorectified Landsat satellite images from the United States Geological Service (USGS Earth Explorer archive were analyzed for the 1972 to 2009 period. The images encompassed Lake Mead (a major reservoir in this region and were examined for changes in water surface area. Decadal lake area minimums/maximums were achieved in 1972/1979, 1981/1988, 1991/1998, and 2009/2000. The minimum lake area extent occurred in 2009 (356.4 km2, while the maximum occurred in 1998 (590.6 km2. Variable trends in water level and lake area were observed throughout the analysis period, however progressively lower values were observed since 2000. The Landsat derived lake areas show a very strong relationship with actual measured water levels at the Hoover Dam. Yearly water level variations at the dam vary minimally from the satellite derived estimates. A complete (yearly record of satellite images may have helped to reduce the slight deviations in the time series.

  17. Surface deformation of active volcanic areas retrieved with the SBAS-DInSAR technique: an overview

    Directory of Open Access Journals (Sweden)

    G. Zeni

    2008-06-01

    Full Text Available This paper presents a comprehensive overview of the surface deformation retrieval capability of the Differential Synthetic Aperture Radar Interferometry (DInSAR algorithm, referred to as Small BAseline Subset (SBAS technique, in the context of active volcanic areas. In particular, after a brief description of the algorithm some experiments relevant to three selected case-study areas are presented. First, we concentrate on the application of the SBAS algorithm to a single-orbit scenario, thus considering a set of SAR data composed by images acquired on descending orbits by the European Remote Sensing (ERS radar sensors and relevant to the Long Valley caldera (eastern California area. Subsequently, we address the capability of the SBAS technique in a multipleorbit context by referring to Mt. Etna volcano (southern Italy test site, with respect to which two different ERS data set, composed by images acquired both on ascending and descending orbits, are available. Finally, we take advantage of the capability of the algorithm to work in a multi-platform scenario by jointly exploiting two different sets of SAR images collected by the ERS and the Environment Satellite (ENVISAT radar sensors in the Campi Flegrei caldera (southern Italy area. The presented results demonstrate the effectiveness of the algorithm to investigate the deformation field in active volcanic areas and the potential of the DInSAR methodologies within routine surveillance scenario.

  18. Stone anchors from Bet Dwarka Island, Gujarat, Coast, India: Significance to historical period maritime activities

    Digital Repository Service at National Institute of Oceanography (India)

    Sundaresh; Gaur, A.S.; Tripati, S.; Gudigar, P.; Bandodkar, S.N.

    Bet Dwarka Island is situated on the extreme west of Indian territory in Jamnagar district of Gujarat. Underwater, the most preserved remains of ancient maritime activity could be the stone anchors of different types, as every boat requires...

  19. Stabilization of the dimeric birch pollen allergen Bet v 1 impacts its immunological properties.

    Science.gov (United States)

    Kofler, Stefan; Ackaert, Chloé; Samonig, Martin; Asam, Claudia; Briza, Peter; Horejs-Hoeck, Jutta; Cabrele, Chiara; Ferreira, Fatima; Duschl, Albert; Huber, Christian; Brandstetter, Hans

    2014-01-03

    Many allergens share several biophysical characteristics, including the capability to undergo oligomerization. The dimerization mechanism in Bet v 1 and its allergenic properties are so far poorly understood. Here, we report crystal structures of dimeric Bet v 1, revealing a noncanonical incorporation of cysteine at position 5 instead of genetically encoded tyrosine. Cysteine polysulfide bridging stabilized different dimeric assemblies, depending on the polysulfide linker length. These dimers represent quaternary arrangements that are frequently observed in related proteins, reflecting their prevalence in unmodified Bet v 1. These conclusions were corroborated by characteristic immunologic properties of monomeric and dimeric allergen variants. Hereby, residue 5 could be identified as an allergenic hot spot in Bet v 1. The presented results refine fundamental principles in protein chemistry and emphasize the importance of protein modifications in understanding the molecular basis of allergenicity.

  20. Misestimating betting behavior: the role of negative asymmetries in emotional self prediction.

    Science.gov (United States)

    Andrade, Eduardo B; Claro, Danny P; Islam, Gazi

    2014-12-01

    This paper addresses the role of negative asymmetries in emotional self-prediction by looking at the extent to which individuals misestimate their own betting behavior in sequential gambles. In a series of three experimental studies, we demonstrate that losses lead to higher than planned bets whereas bets are on average carried over after gains. Such asymmetric deviations from the plan emerge (1) when monetary and non-monetary incentives are used, and (2) when participants face fair and unfair gambles. The asymmetry is based on people's inability to predict how much the negative emotions generated by a bad experience (e.g. the loss) will influence them to put more effort (e.g. bet more) than planned in an attempt to re-establish a homeostatic state in the prospect of a good experience (e.g. winning).

  1. Bet hedging or not? A guide to proper classification of microbial survival strategies

    NARCIS (Netherlands)

    de Jong, Imke G.; Haccou, Patsy; Kuipers, Oscar P.

    2011-01-01

    Bacteria have developed an impressive ability to survive and propagate in highly diverse and changing environments by evolving phenotypic heterogeneity. Phenotypic heterogeneity ensures that a subpopulation is well prepared for environmental changes. The expression bet hedging is commonly (but often

  2. Guidance manual on the estimation of airborne asbestos concentrations as a function of distance from a contaminated surface area for area suspension evaluations

    Energy Technology Data Exchange (ETDEWEB)

    Stenner, R.D.; Droppo, J.G.; Peloquin, R.A.; Bienert, R.W.; VanHouten, N.C.

    1990-04-01

    This Guidance Manual provides a quantitative approach for estimating the airborne concentrations of asbestos from disturbed soils and surfaces. Asbestos-containing surfaces may include roads surfaced with asbestos-bearing serpentine rock, tailings piles, and landfills. This manual identifies the procedures necessary for estimating airborne concentrations of asbestos in disturbed soils. The manual is to be used in conjunction with the Airborne Asbestos Concentration Estimator System-Area Suspension (AACES-AS) computer code. 44 refs., 16 figs., 7 tabs.

  3. Where Does the Formula Come from? Students Investigating Total Surface Areas of a Pyramid and Cone Using Models and Technology

    Science.gov (United States)

    Obara, Samuel

    2009-01-01

    Spatial reasoning is a skill that needs to be developed in students as it is important in geometry for determining total surface areas and volumes of 3-dimensional shapes (Liedtke, 1995). Simply teaching children the formulae, in this case for finding total surface areas, can limit them in understanding mathematics conceptually (Bonotto, 2003).…

  4. Estimating Surface Area of Sponges and Marine Gorgonians as Indicators of Habitat Availability on Caribbean Coral Reefs

    Science.gov (United States)

    Surface area and topographical complexity are fundamental attributes of shallow tropical coral reefs and can be used to estimate habitat for fish and invertebrates. This study presents empirical methods for estimating surface area provided by sponges and gorgonians in the Central...

  5. Influence of Alkali Treatment on the Surface Area of Aluminium Dross

    Directory of Open Access Journals (Sweden)

    N. S. Ahmad Zauzi

    2016-01-01

    Full Text Available Aluminium dross is an industrial waste from aluminium refining industry and classified as toxic substances. However, the disposal of dross as a waste is a burden to aluminium manufacturer industries due to its negative effects to the ecosystem, surface, and ground water. Therefore the purpose of this study is to evaluate the influence of sodium hydroxide (NaOH on the surface area and pore size of aluminium dross. There were 3 stages in the treatment activities, which were leaching, precipitation, and calcination process. The optimum result from this study was the surface area of aluminium dross increases from 10.1 m2/g up to 80.0 m2/g at 40°C, 1% NaOH, and 15-minute reaction time. Thus, aluminium dross has a potential to be converted into other useful material such as catalyst and absorbent. The benefit of this research is that the hazardous industrial waste can be turned into wealth to be used in other applications such as in catalytic activities and absorber in waste water treatment. Further investigation on the physicochemical of aluminium dross with different acid or alkali should be conducted to get deeper understanding on the aluminium dross as a catalyst-type material.

  6. A highly permeable and enhanced surface area carbon-cloth electrode for vanadium redox flow batteries

    Science.gov (United States)

    Zhou, X. L.; Zhao, T. S.; Zeng, Y. K.; An, L.; Wei, L.

    2016-10-01

    In this work, a high-performance porous electrode, made of KOH-activated carbon-cloth, is developed for vanadium redox flow batteries (VRFBs). The macro-scale porous structure in the carbon cloth formed by weaving the carbon fibers in an ordered manner offers a low tortuosity (∼1.1) and a broad pore distribution from 5 μm to 100 μm, rendering the electrode a high hydraulic permeability and high effective ionic conductivity, which are beneficial for the electrolyte flow and ion transport through the porous electrode. The use of KOH activation method to create nano-scale pores on the carbon-fiber surfaces leads to a significant increase in the surface area for redox reactions from 2.39 m2 g-1 to 15.4 m2 g-1. The battery assembled with the present electrode delivers an energy efficiency of 80.1% and an electrolyte utilization of 74.6% at a current density of 400 mA cm-2, as opposed to an electrolyte utilization of 61.1% achieved by using a conventional carbon-paper electrode. Such a high performance is mainly attributed to the combination of the excellent mass/ion transport properties and the high surface area rendered by the present electrode. It is suggested that the KOH-activated carbon-cloth electrode is a promising candidate in redox flow batteries.

  7. Pollutant loads of surface runoff in Wuhan City Zoo, an urban tourist area

    Institute of Scientific and Technical Information of China (English)

    ZHAO Jian-wei; SHAN Bao-qing; YIN Cheng-qing

    2007-01-01

    The pollutant loads of surface runoff in an urban tourist area have been investigated for two years in the Wuhan City Zoo, China. Eight sampling sites, including two woodlands, three animal yards, two roofs and one road, were selected for sampling and study. The results indicate that pollutants ranked in a predictable order of decreasing load (e.g. animal yard>roof>woodland>road), with animal yards acting as the key pollution source in the zoo. Pollutants were transported mainly by particulate form in runoff. Particulate nitrogen (PN) and particulate phosphorous (PP) accounted on average for 61%, 78% of total pollutant, respectively, over 13 monitored rainfall events. These results indicate the treatment practices should be implemented to improve particulate nutrient removal. Analysis of the M(V) curve indicated that no first flush effect existed in the surface runoff from pervious areas (e.g. woodland, animal ground yard), whereas a first flush effect was evident in runoff from impervious surfaces (e.g. animal cement yard, roof, road).

  8. Preparation and Characterization of High Surface Area Activated Carbon Fibers from Lignin

    Directory of Open Access Journals (Sweden)

    Jian Lin

    2016-10-01

    Full Text Available Activated carbon fibers (ACFs were successfully prepared from softwood lignin, which was isolated with polyethylene glycol 400 (PEG-400 as a solvolysis reagent, by water steam activation. The pore characterization and adsorption property of ACFs were investigated. The results showed that all the ACFs with more micropores exhibited high specific surface area and total pore volume which increased with the activation time prolonging; the highest ones were around 3100 m2/g and 1.5 mL/g, respectively. The specific surface area and total pore volume were much larger than those of other types of lignin-based ACFs and activated charcoal. Besides, with increasing activation time, the amount of graphitic carbon, which was the main compound on the surface of ACFs, decreased, while the amount of functional groups containing C–O slightly increased. In addition, the adsorption capacity of ACFs for methylene blue was highly increased as the activation time increased. Accordingly, lignin isolated with PEG is a promising precursor for ACF production.

  9. Organic molecules as sorbing tracers for the assessment of surface areas in consolidated aquifer systems

    Science.gov (United States)

    Schaffer, Mario; Warner, Wiebke; Kutzner, Susann; Börnick, Hilmar; Worch, Eckhard; Licha, Tobias

    2017-03-01

    Based on the assumption that the specific surface area to volume ratio Asurf/V of consolidated rock materials is proportional to the surface area available for sorption, several inorganic cations were recently proposed as sorbing (cation exchanging) tracers for estimating these ratios in aquifers (e.g., for deriving the efficient heat exchange area of geothermal reservoirs). The main disadvantages of inorganic ions, however, are the limited number of suitable ions, their potential geogenic background, and their challenging online detection at trace concentrations. In this work, the spectrum of chemical substances used as sorbing tracers expands by considering fluorescent organic compounds that are cationic. They have the advantage of being highly water soluble and easy to measure online at very low concentrations. Results from systematic lab column experiments with seven selected organic cations under various conditions (different salinities and temperatures) are presented, emphasizing the potential of organic molecules as alternative sorbing tracers especially in consolidated aquifer systems. This work is a first stepping stone in identifying suitable molecular structures that can be selected or even individually adapted to the requirements of the tracer tests and prevailing aquifer conditions.

  10. Characteristics of PAHs adsorbed on street dust and the correlation with specific surface area and TOC.

    Science.gov (United States)

    Wang, Chengkun; Li, Yingxia; Liu, Jingling; Xiang, Li; Shi, Jianghong; Yang, Zhifeng

    2010-10-01

    Street dust was collected from five roads with different traffic volumes in the metropolitan area of Beijing and separated into five size fractions. Concentrations of polycyclic aromatic hydrocarbons (PAHs) adsorbed on street dust in different size ranges and their correlation with specific surface area and total organic carbon (TOC) were investigated. Results show that the concentration of 16-PAHs of sieved samples ranges from 0.27 to 1.30 mg/kg for all the sampling sites. Particles smaller than 40 mum in diameter have the highest 16-PAHs concentration among all of the size ranges for street dust from the four sampling sites with vehicles running on. PAHs with three or four rings account for 68% of the overall 16-PAHs on average. Remarkable positive correlation exists between 16-PAHs concentration and specific surface area with R(2) values from 0.7 to 0.96 for the four sampling sites with vehicles running on. The relationship between the concentration of 16-PAHs and TOC is less clear.

  11. [Forms of pathological gambling: empirical research on consumers behaviour of sport betting and lottery participants].

    Science.gov (United States)

    Plöntzke, Babett; Albrecht, Ulrike; Thalemann, Carolin; Grüsser, Sabine Miriam

    2004-08-01

    Gambling is one of the favourite leisure activities. 70-90 % of the grown-up population have gambled at least once in their life. Over the last few years, however, the variety of opportunities to gamble has changed. Decreasing numbers of casino visitors can be seen against an ever-increasing number of people using slot machines, and taking part in national lotteries and sport betting. Comprehensive empirical research regarding consumer behaviour and addiction potential involved in sport betting has been non-existent and only a few studies have dealt with lottery. In the present study, 108 subjects were questioned in Austrian betting offices. 33.3 % of the sample fulfilled the diagnostic criteria for pathological sport betting. Of the sport betting subjects who additionally play lottery, 22.92 % were diagnosed as being pathological lottery gamblers. Based on the criteria of substance addiction, the data demonstrate that sport betting and lottery have addiction potential and can therefore be seen as non-substance-related addiction.

  12. Mating portfolios: bet-hedging, sexual selection and female multiple mating.

    Science.gov (United States)

    Garcia-Gonzalez, Francisco; Yasui, Yukio; Evans, Jonathan P

    2015-01-07

    Polyandry (female multiple mating) has profound evolutionary and ecological implications. Despite considerable work devoted to understanding why females mate multiply, we currently lack convincing empirical evidence to explain the adaptive value of polyandry. Here, we provide a direct test of the controversial idea that bet-hedging functions as a risk-spreading strategy that yields multi-generational fitness benefits to polyandrous females. Unfortunately, testing this hypothesis is far from trivial, and the empirical comparison of the across-generations fitness payoffs of a polyandrous (bet hedger) versus a monandrous (non-bet hedger) strategy has never been accomplished because of numerous experimental constraints presented by most 'model' species. In this study, we take advantage of the extraordinary tractability and versatility of a marine broadcast spawning invertebrate to overcome these challenges. We are able to simulate multi-generational (geometric mean) fitness among individual females assigned simultaneously to a polyandrous and monandrous mating strategy. Our approaches, which separate and account for the effects of sexual selection and pure bet-hedging scenarios, reveal that bet-hedging, in addition to sexual selection, can enhance evolutionary fitness in multiply mated females. In addition to offering a tractable experimental approach for addressing bet-hedging theory, our study provides key insights into the evolutionary ecology of sexual interactions.

  13. The Fold Variant BM4 Is Beneficial in a Therapeutic Bet v 1 Mouse Model

    Directory of Open Access Journals (Sweden)

    Ulrike Pichler

    2013-01-01

    Full Text Available Background. Specific immunotherapy using recombinant allergens is clinically effective; still wild-type allergens can provoke treatment-induced side effects and often show poor immunogenicity in vivo. Thus, we tested the low IgE-binding, highly immunogenic fold variant BM4 in a Bet v 1 mouse model. Methods. Recombinant BM4 was used as active vaccine ingredient to treat mice sensitized to Bet v 1. As controls, mice were treated with either Bet v 1 or sham, and the humoral as well as cellular immune response was monitored. Moreover, lung function and lung inflammation were analysed. Results. BM4 was more effective than wild-type Bet v 1 in inducing Bet v 1-specific blocking antibodies as well as IFN-γ and IL-10 producing T cells. Further, birch pollen induced lung inflammation could be ameliorated significantly by BM4 treatment as demonstrated by a reduction of airway hyperresponsiveness and drastically decreased eosinophil counts in bronchoalveolar lavage fluids. Conclusion. The study outlines the high potential of BM4 as vaccine candidate for the treatment of Bet v 1-mediated birch pollen allergies.

  14. On the extension of the sensitive area of an extensive air shower surface array

    CERN Document Server

    Kh, H Hedayati

    2016-01-01

    A large distance between true and reconstructed core locations of an extensive air shower (EAS) may results in great systematic mis-estimation of EAS parameters. The reconstruction of those EASs whose core locations are outside the boundary of a surface array (outside EAS (OEAS)) results in a large distance of the reconstructed core location from the true one, especially when the true core is far outside the array. Although it may not be mentioned, the identification of OEASs is a necessary and important step in the reconstruction procedure of an EAS. In this paper, an existing technique is optimized for the identification of OEASs. The simultaneous use of this technique and a recently developed approach for reconstructing the core location of an EAS can significantly increase the sensitive area of a surface array.

  15. High surface area graphite as alternative support for proton exchange membrane fuel cell catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira-Aparicio, P.; Folgado, M.A. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT), Avda. Complutense 22, E-28040 Madrid (Spain); Daza, L. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT), Avda. Complutense 22, E-28040 Madrid (Spain); Instituto de Catalisis y Petroleoquimica (CSIC), C/Marie Curie, 2 Campus de Cantoblanco, E-28049 Madrid (Spain)

    2009-07-01

    The suitability of a high surface area graphite (HSAG) as proton exchange membrane fuel cell (PEMFC) catalyst support has been evaluated and compared with that of the most popular carbon black: the Vulcan XC72. It has been observed that Pt is arranged on the graphite surface resulting in different structures which depend on the catalysts synthesis conditions. The influence that the metal particle size and the metal-support interaction exert on the catalysts degradation rate is analyzed. Temperature programmed oxidation (TPO) under oxygen containing streams has been shown to be a useful method to assess the resistance of PEMFC catalysts to carbon corrosion. The synthesized Pt/HSAG catalysts have been evaluated in single cell tests in the cathode catalytic layer. The obtained results show that HSAG can be a promising alternative to the traditionally used Vulcan XC72 carbon black when suitable catalysts synthesis conditions are used. (author)

  16. Changes in porosity, permeability and surface area during rock dissolution: effects of mineralogical heterogeneity

    CERN Document Server

    Min, Ting; Chen, Li; Kang, Qinjun; Tao, Wen-Quan

    2015-01-01

    Effects of heterogeneity of mineral distribution and reaction rate on the rock dissolution process are investigated using a pore-scale reactive transport model based on the lattice Boltzmann method. Coupled fluid flow, species transport, chemical reaction and solid structure alternation due to dissolution are simulated. Effects of mineral distributions and chemical heterogeneity on the dissolution behaviors and evolutions of hydrologic properties are studied under different reactive transport conditions. Simulation results show that the coupling between advection, diffusion and reaction as well as the mineralogical heterogeneity leads to complex reactive transport behaviors and complicated temporal evolutions of hydrologic properties including porosity, permeability and reactive surface. Diverse relationships between surface area and volume are predicted, which cannot be described by simple models such as the spherical-grain model. Porosity-permeability relationships also differ under different mineral distri...

  17. MODELLING OF SURFACE OZONE USING ARTIFICIAL NEURAL NETWORK IN AN URBAN AREA

    Directory of Open Access Journals (Sweden)

    S.Stephen Rajkumar Inbanathan,

    2011-02-01

    Full Text Available In this paper a novel approach, based on a neural network structure, is introduced in order to face with the problem of pollutant estimation in an urban area. A neural architecture, based essentiallyon suitable number of layers devoted to predict alarm situations and to estimate the value of the pollutant, has been implemented. A new method for short term prediction is presented using the neural network technique. Due to increase in industrial and anthropogenic activity, air pollution is a serious subject of concern today. Surface ozone prediction using the technique of adaptive pattern recognition is developed. The model can predict the mean surface ozone based on the parameters like Nitrogen-dioxide, temperature and % Relative Humidity, wind direction, wind speed. The model can perform well both in training and independent periods. The classical methods of short term modeling are not reliable enough. The method can also be used for short term prediction of other air pollutants.

  18. Hydrophobic high surface area zeolites derived from fly ash for oil spill remediation.

    Science.gov (United States)

    Sakthivel, Tamilselvan; Reid, David L; Goldstein, Ian; Hench, Larry; Seal, Sudipta

    2013-06-01

    Fly ash, a coal combustion byproduct with a predominantly aluminosilicate composition, is modified to develop an inexpensive sorbent for oil spill remediation. The as-produced fly ash is a hydrophilic material with poor sorption capacity. A simple two-step chemical modification process is designed to improve the oil sorption capacity. First, the fly ash was transformed to a zeolitic material via an alkali treatment, which increased the specific surface area up to 404 m(2) g(-1). Then, the material was surface functionalized to form a hydrophobic material with high contact angle up to 147° that floats on the surface of an oil-water mixture. The reported oil sorption capacities of X-type zeolite sorbent with different surface functionalization (propyl-, octyl-, octadecyl-trimethoxysilane and esterification) were estimated to 1.10, 1.02, 0.86, and 1.15 g g(-1), respectively. Oil sorption was about five times higher than the as-received fly ash (0.19 g g(-1)) and also had high buoyancy critical for economic cleanup of oil over water.

  19. Parasitic contamination of surface and deep soil in different areas of Sari in north of Iran

    Directory of Open Access Journals (Sweden)

    Hajar Ziaei Hezarjaribi

    2016-10-01

    Full Text Available Objective: To study the parasitic contamination of soil in selected areas of Sari, north of Iran. Methods: A cross-sectional study was conducted to identify all available parasites in surface and deep soil. In this study 580 soil samples (278 deep soil and 302 topsoil samples from 21 different locations were collected from pathways, parks, greenhouses, estates around the city, cemetery, main squares, farmlands, fenced gardens and seashores. Depending on the soil type, two samples were prepared, from surface and deep soil at the depth of 3 to 5 cm. After performing various stages of preparation, including cleaning and washing, smoothing and flotation, parasitic elements were examined microscopically and quantitative parasite counting was done using a McMaster slide. Results: The results showed that the highest rate of parasitic contamination was related to nematodes larvae (26.11%. Other contaminants such as Entamoeba and Acanthamoeba cysts, vacuolization Blastocystis hominis form, oocyte containing sporocysts, Toxascaris eggs, nematoda larvae, Hymenolepis eggs, Ascaris eggs, Fasciola eggs, hookworm eggs, Toxocara eggs, insects' larvae and other ciliated and flagellated organisms were also observed. The results of this study showed that the highest contamination was found in public garden (25.80% both in surface (29.30% and in deep soil (21.12%, while the lowest level of contamination was observed in seashore surface soil (4.90%. Conclusions: The results showed that soil can provide a potential medium for the spread of soil transmitted parasitic diseases in the environment; therefore, preventive programs are needed.

  20. Tungsten carbide modified high surface area carbon as fuel cell catalyst support

    Science.gov (United States)

    Shao, Minhua; Merzougui, Belabbes; Shoemaker, Krista; Stolar, Laura; Protsailo, Lesia; Mellinger, Zachary J.; Hsu, Irene J.; Chen, Jingguang G.

    Phase pure WC nanoparticles were synthesized on high surface area carbon black (800 m 2 g -1) by a temperature programmed reaction (TPR) method. The particle size of WC can be controlled under 30 nm with a relatively high coverage on the carbon surface. The electrochemical testing results demonstrated that the corrosion resistance of carbon black was improved by 2-fold with a surface modification by phase pure WC particles. However, the WC itself showed some dissolution under potential cycling. Based on the X-ray diffraction (XRD) and inductively coupled plasma (ICP) analysis, most of the WC on the surface was lost or transformed to oxides after 5000 potential cycles in the potential range of 0.65-1.2 V. The Pt catalyst supported on WC/C showed a slightly better ORR activity than that of Pt/C, with the Pt activity loss rate for Pt/WC/C being slightly slower compared to that of Pt/C. The performance and decay rate of Pt/WC/C were also evaluated in a fuel cell.

  1. Luminosity and surface brightness distribution of K-band galaxies from the UKIDSS Large Area Survey

    CERN Document Server

    Smith, Anthony J; Cross, Nicholas J G

    2008-01-01

    We present luminosity and surface brightness distributions of 36,663 galaxies with K-band photometry from the UKIRT Infrared Deep Sky Survey (UKIDSS) Large Area Survey (LAS), Data Release 3 and optical photometry from Data Release 5 of the Sloan Digital Sky Survey (SDSS). Various features and limitations of the new UKIDSS data are examined, such as a problem affecting Petrosian magnitudes of extended sources. Selection limits in K- and r-band magnitude, K-band surface brightness and K-band radius are included explicitly in the 1/Vmax estimation of the space density and luminosity function. The bivariate brightness distribution in K-band absolute magnitude and surface brightness is presented and found to display a clear luminosity-surface brightness correlation that flattens at high luminosity and broadens at low luminosity, consistent with similar analyses at optical wavelengths. Best fitting Schechter function parameters for the K-band luminosity function are found to be M*-5log h=-23.17 +/- 0.04, alpha=-0.8...

  2. A Framework for Analyzing the Whole Body Surface Area from a Single View

    Science.gov (United States)

    Doretto, Gianfranco; Adjeroh, Donald

    2017-01-01

    We present a virtual reality (VR) framework for the analysis of whole human body surface area. Usual methods for determining the whole body surface area (WBSA) are based on well known formulae, characterized by large errors when the subject is obese, or belongs to certain subgroups. For these situations, we believe that a computer vision approach can overcome these problems and provide a better estimate of this important body indicator. Unfortunately, using machine learning techniques to design a computer vision system able to provide a new body indicator that goes beyond the use of only body weight and height, entails a long and expensive data acquisition process. A more viable solution is to use a dataset composed of virtual subjects. Generating a virtual dataset allowed us to build a population with different characteristics (obese, underweight, age, gender). However, synthetic data might differ from a real scenario, typical of the physician’s clinic. For this reason we develop a new virtual environment to facilitate the analysis of human subjects in 3D. This framework can simulate the acquisition process of a real camera, making it easy to analyze and to create training data for machine learning algorithms. With this virtual environment, we can easily simulate the real setup of a clinic, where a subject is standing in front of a camera, or may assume a different pose with respect to the camera. We use this newly designated environment to analyze the whole body surface area (WBSA). In particular, we show that we can obtain accurate WBSA estimations with just one view, virtually enabling the possibility to use inexpensive depth sensors (e.g., the Kinect) for large scale quantification of the WBSA from a single view 3D map. PMID:28045895

  3. Self-assembly of virus-structured high surface area nanomaterials and their application as battery electrodes.

    Science.gov (United States)

    Royston, Elizabeth; Ghosh, Ayan; Kofinas, Peter; Harris, Michael T; Culver, James N

    2008-02-05

    High area nickel and cobalt surfaces were assembled using modified Tobacco mosaic virus (TMV) templates. Rod-shaped TMV templates (300 x 18 nm) engineered to encode unique cysteine residues were self-assembled onto gold patterned surfaces in a vertically oriented fashion, producing a >10-fold increase in surface area. Electroless deposition of ionic metals onto surface-assembled virus templates produced uniform metal coatings up to 40 nm in thickness. Within a nickel-zinc battery system, the incorporation of virus-assembled electrode surfaces more than doubled the total electrode capacity. When combined, these findings demonstrate that surface-assembled virus templates provide a robust platform for the fabrication of oriented high surface area materials.

  4. Catalytic Chemical Vapor Deposition Synthesis of Carbon Aerogels of High-Surface Area and Porosity

    Directory of Open Access Journals (Sweden)

    Armando Peña

    2012-01-01

    Full Text Available In this work carbon aerogels were synthesized by catalytic chemical vapor deposition method (CCVD. Ferrocene were employed as a source both of catalytic material (Fe and of carbon. Gaseous hydrogen and argon were used as reductant and carrier gas, respectively. The products of reaction were collected over alumina. The morphology and textural properties of the soot produced in the reaction chamber were investigated using Scanning Electron Microscopy, High-Resolution Transmission Electron Microscopy, X-ray photoelectron spectroscopy, and N2 physisorption (BET and BHJ methods. After the evaluation of the porous structure of the synthesized products, 780 ± 20 m2/g of SBET and 0.55 ± 0.02 cm3/g of VBJH were found. The presence of iron carbide and the partial oxidation of carbon nanostructures were revealed by XPS.

  5. Ocular surface area and human eye blink frequency during VDU work

    DEFF Research Database (Denmark)

    Nielsen, Pernille Kofoed; Søgaard, Karen; Skotte, Jørgen

    2008-01-01

    The purpose of this study was to investigate how the ocular surface area (OSA) and the eye blink frequency (BF) are affected by a high versus a low-monitor position during visual display unit (VDU) work with varying cognitive demands. In a balanced randomized (2 x 2) design ten healthy subjects....... The low BF during the active task was succeded by a burst with high BF after cessation of the active task, indicating a compensatory blinking process. This stresses that interchange of work tasks with different cognitive load is as important as the monitor position in the prevention of visual...

  6. Body conformable 915 MHz microstrip array applicators for large surface area hyperthermia

    Energy Technology Data Exchange (ETDEWEB)

    Lee, E.R.; Tarczy-Hornoch, P.; Kapp, S.; Fessenden, P.; Lohrbach, A.W.; Prionas, S.D. (Stanford University Medical Center, CA (United States)); Wilsey, T. (Carian Associates, Palo Alto, CA (United States))

    1992-01-01

    The optimal treatment with hyperthermia of superficially located tumors which involve large surface areas requires applicators which can physically conform to body contours, and locally alter their power deposition patterns to adjust for nonuniform temperature caused by tissue inhomogeneities and blood flow variations. A series of 915 MHz microstrip array applicators satisfying these criteria have been developed and clinically tested. Clinical and engineering design tradeoffs for practical devices are discussed. Measurements taken in tissue equivalent phantoms and a summary of clinical experiences with these microstrip arrays are presented.

  7. Experimental investigation of the influences of shape and surface area on the EGR cooler efficiency

    Science.gov (United States)

    Jang, Sanghoon; Park, Sangki; Choi, Kapseung; Kim, Hyungman

    2011-06-01

    The cooled EGR system is one of the most effective techniques currently available for reducing NOx emissions. In this study, engine dynamometer experiments were performed to investigate the efficiencies of the shell and tube-type and stack-type EGR coolers. The results show that the heat exchange of the stack-type EGR cooler is much more effective than that of the shell and tube type because of the increased surface area and better mixing of the coolant flow, and also more PM is produced at low exhaust gas temperature than at high temperature.

  8. Form function and variation of burning surface area for hexa-tubular charge

    Directory of Open Access Journals (Sweden)

    J. N. Kapur

    1964-10-01

    Full Text Available The problem of combustion of a hexa-tubular charge, which is a cylindrical charge with six holes of equal diameters- one at the centre and the other five symmetrically situated about it, has been considered in this paper. The burning of the charge proceeds in three distinct phases for each of which the form function and variation of burning surface area has been investigated. Equivalent form-factor has also been found. Numerical results for some important cases are tabulated.

  9. Relationship between surface area and crystal size of pure and doped cerium oxides

    Institute of Scientific and Technical Information of China (English)

    C.; Bueno-Ferrer; S.; Parres-Esclapez; D.; Lozano-Castelló; A.; Bueno-López

    2010-01-01

    Pure and Zr, La or Pr-doped cerium oxides were characterised by transmission electron microscopy (TEM), N2 adsorption-desorption at -196 oC and X-ray diffraction (XRD). For crystal sizes calculation, the Scherrer and Williamson-Hall equations were compared, and the relationship between surface area and crystal size was critically discussed. It was demonstrated that the Williamson-Hall equation must be used instead of the Scherrer equation to calculate crystal sizes, since the latter equation underestimated ...

  10. Understanding the growth mechanism of carbon nanotubes via the ``cluster volume to surface area" model

    Science.gov (United States)

    Mandati, Sreekanth; Kunstmann, Jens; Boerrnert, Felix; Schoenfelder, Ronny; Ruemmeli, Mark; Kar, Kamal K.; Cuniberti, Gianaurelio

    2010-03-01

    The influence of mixed catalysts for the high yield production of carbon nanotubes (CNTs) has been studied systematically. Based on extensive experimental data a ``Catalyst Volume to Surface Area'' (CVSA) model was developed to understand the influence of the process parameters on the yield and CNT diameter distribution [1]. In our study, we present a refined version of the CVSA model developed by combining experiments and simulations. We discuss our current understanding of the growth mechanism and how the model might be used to increase CNT yields by using mixed catalysts.[4pt] [1] S. Tetali et al., ACS Nano (2009), DOI: 10.1021/nn9012548.

  11. octanol/water partition coefficient using solvation free energy and solvent-accessible surface area

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The regression model for octanol/water partition coefficients (Kow ), is founded with only two molecular descriptors available through quantum chemical calculations: solvation free energy (△ Gs ), and solvent-accessible surface area (SASA). For the properties of 47 organic compounds from 17 types, the model gives a oonection coefficient (adjusted for degrees of freedom) of 0.959 and a standard error of 0.277 log unit. It is a suitable way to predict the partition properties that are related to solute-solvent interactions in the water phase.

  12. Indexing of renal function parameters by body surface area: intelligence or folly?

    Science.gov (United States)

    Delanaye, Pierre; Krzesinski, Jean-Marie

    2011-01-01

    Indexation of glomerular filtration rate (GFR) by body surface area (BSA) is often done without raising any questions. In this article, we will shortly review the limitations of such indexation and illustrate potential errors in clinical practice due to this indexation. Adjusting the GFR by BSA is particularly misleading in patients with abnormal body size (obese and anorectic). We will also insist on the fact that indexation by BSA is not required for the GFR longitudinal follow-up. Additionally, we will discuss the implications and consequences of BSA indexation on the creatinine-based equations, such as the Cockcroft-Gault and the MDRD study equations.

  13. Measurement of Specific Surface Area of Ceramisite Made from River Sediment

    Institute of Scientific and Technical Information of China (English)

    LIU Gui-yun; XI Dan-li

    2002-01-01

    Principle and method of measuring Specific Surface Area (SSA) of ceramisite made from dredged river sediment,sewage sludge and adherent materials are discussed.Brunauer-Fmmett- Teller Procedure tests SSA of the ceramisite. Influences of sewage sludge content,adherent content and sintering point on the SSA of ceramisite made of river sediment are also analyzed.Results show that with the right sewage sludge content,adherent content and sintering point, the ceramisite can have the highest SSA value and be widely used.

  14. Nitrogen-doped porous carbon with an ultrahigh specific surface area for superior performance supercapacitors

    Science.gov (United States)

    Long, Chao; Zhuang, Jianle; Xiao, Yong; Zheng, Mingtao; Hu, Hang; Dong, Hanwu; Lei, Bingfu; Zhang, Haoran; Liu, Yingliang

    2016-04-01

    Owing to its abundant nitrogen content, silk cocoon is a promising precursor for the synthesis of Nitrogen-doped porous carbon (N-PC). Using a simple staged KOH activation, the prepared sample displays particular nanostructure with ultrahigh specific surface area (3841 m2 g-1) and appropriate pore size, providing favorable pathways for transportation and penetration of electrolyte ions. Additionally, the doped nitrogen atoms ensure the samples with pseudocapacitive behavior. Those special characteristics endow N-PCs with high capacity, low resistance, and long-term stability, indicating a wonderful potential for application in energy-storage devices.

  15. Automated Generation of Digital Terrain Model using Point Clouds of Digital Surface Model in Forest Area

    Directory of Open Access Journals (Sweden)

    Yoshikazu Kamiya

    2011-04-01

    Full Text Available At present, most of the digital data acquisition methods generate Digital Surface Model (DSM and not a Digital Elevation Model (DEM. Conversion from DSM to DEM still has some drawbacks, especially the removing of off terrain point clouds and subsequently the generation of DEM within these spaces even though the methods are automated. In this paper it was intended to overcome this issue by attempting to project off terrain point clouds to the terrain in forest areas using Artificial Neural Networks (ANN instead of removing them and then filling gaps by interpolation. Five sites were tested and accuracies assessed. They all give almost the same results. In conclusion, the ANN has ability to obtain the DEM by projecting the DSM point clouds and greater accuracies of DEMs were obtained. If the size of the hollow areas resulting from the removal of DSM point clouds are larger the accuracies are reduced.

  16. Low surface area graphene/cellulose composite as a host matrix for lithium sulphur batteries

    Science.gov (United States)

    Patel, Manu U. M.; Luong, Nguyen Dang; Seppälä, Jukka; Tchernychova, Elena; Dominko, Robert

    2014-05-01

    Graphene/cellulose composites were prepared and studied as potential host matrixes for sulphur impregnation and use in Li-S batteries. We demonstrate that with the proper design of a relatively low surface area graphene/cellulose composite, a high electrochemical performance along with good cyclability can be achieved. Graphene cellulose composites are built from two constituents: a two-dimensional electronic conductive graphene and cellulose fibres as a structural frame; together they form a laminar type of pore. The graphene sheets that uniformly anchor sulphur molecules provide confinement ability for polysulphides, sufficient space to accommodate sulphur volumetric expansion, a large contact area with the sulphur and a short transport pathway for both electrons and lithium ions. Nano-cellulose prevents the opening of graphene sheets due to the volume expansion caused by dissolved polysulphides during battery operation. This, in turn, prevents the diffusion of lithium polysulphides into the electrolyte, enabling a long cycle life.

  17. High Surface Area Nanoporous Ti02 Coating for Effective Water Condensation.

    Science.gov (United States)

    Kaynar, Mehmet; McGarity, Mark; Yassitepe, Emre; Shah, S.

    2013-03-01

    A water collection device utilizing nanoparticles has been researched, towards the possible goal of providing water in much needed areas on Earth. Titanium dioxide nanoparticles were spray coated on stainless steel substrates to measure their effect on atmospheric water condensation. A simple thermoelectric cooler, also called a Peltier device, was used to lower the temperature of the coated and uncoated stainless steel substrates to below the dew point temperature of the surrounding air. The thickness of the spray coating was varied to measure its effect on water condensation. This increase in surface area had a direct effect on the amount of water condensed. Compared with bare stainless steel, the TiO2 spray coated stainless steel had a considerably smaller contact angle of H20 droplets. In addition, the super-hydrophilic properties of TiO2 allowed water to flow more easily off the device. Supported by TUBITAK-BIDEB 2214-Abroad Research Scholarship program.

  18. Surface Area Variability of a North-Central Tanzanian Crater Lake

    Directory of Open Access Journals (Sweden)

    Lindsey Higgins

    2016-06-01

    Full Text Available A history of modern (1973–2015 surface area variability for Lake Basotu in north-central Tanzania has been reconstructed using archived Landsat images from the dry season between June and October. This record was compared to local weather data as well as larger scale weather patterns. The lake has been in a state of decline interrupted by major flood events since the beginning of the satellite record. From 1973 to 1997, the lake area was between 0.97 km2 and 4.28 km2. Lake extent abruptly increased to 13.86 km2 in 1998, when a co-occurrence of El Niño and a positive Indian Ocean Dipole led to extensive flooding. It is hypothesized that local agricultural practices leading to soil erosion and subsequent basin sedimentation have most likely increased the sensitivity of Lake Basotu to climatic fluctuations.

  19. Dose-area product and entrance surface dose in paediatric radiography

    Energy Technology Data Exchange (ETDEWEB)

    Servomaa, A.; Komppa, T.; Parviainen, T.; Heikkilae, M. [STUK - Radiation and Nuclear Safety Authority, Helsinki (Finland)

    2003-06-01

    Dose-area products (DAP) in paediatric radiography were measured in four university hospitals in Finland. The entrance surface dose (ESD) was calculated from the measured DAP value for each radiographic projection. The purpose was to combine the results with other European studies for development of diagnostic reference levels for paediatric X-ray examinations. The study included 740 paediatric patients, and a total of 1500 single projections were recorded, including 660 projections from extremities. Results were compared with recommended best practices and diagnostic reference levels for ESD. Ratios of DAP to ESD were studied to estimate the levels of DAP corresponding to recommended ESD reference levels. It is desirable for practical purposes that diagnostic reference levels for radiographic projections are also expressed in terms of dose-area product. (orig.)

  20. Protein-protein interactions: general trends in the relationship between binding affinity and interfacial buried surface area.

    Science.gov (United States)

    Chen, Jieming; Sawyer, Nicholas; Regan, Lynne

    2013-04-01

    Protein-protein interactions play key roles in many cellular processes and their affinities and specificities are finely tuned to the functions they perform. Here, we present a study on the relationship between binding affinity and the size and chemical nature of protein-protein interfaces. Our analysis focuses on heterodimers and includes curated structural and thermodynamic data for 113 complexes. We observe a direct correlation between binding affinity and the amount of surface area buried at the interface. For a given amount of surface area buried, the binding affinity spans four orders of magnitude in terms of the dissociation constant (Kd ). Across the entire dataset, we observe no obvious relationship between binding affinity and the chemical composition of the interface. We also calculate the free energy per unit surface area buried, or "surface energy density," of each heterodimer. For interfacial surface areas between 500 and 2000 Å(2) , the surface energy density decreases as the buried surface area increases. As the buried surface area increases beyond about 2000 Å(2) , the surface energy density levels off to a constant value. We believe that these analyses and data will be useful for researchers with an interest in understanding, designing or inhibiting protein-protein interfaces.

  1. Changes in satellite-derived impervious surface area at US historical climatology network stations

    Science.gov (United States)

    Gallo, Kevin; Xian, George

    2016-10-01

    The difference between 30 m gridded impervious surface area (ISA) between 2001 and 2011 was evaluated within 100 and 1000 m radii of the locations of climate stations that comprise the US Historical Climatology Network. The amount of area associated with observed increases in ISA above specific thresholds was documented for the climate stations. Over 32% of the USHCN stations exhibited an increase in ISA of ⩾20% between 2001 and 2011 for at least 1% of the grid cells within a 100 m radius of the station. However, as the required area associated with ISA change was increased from ⩾1% to ⩾10%, the number of stations that were observed with a ⩾20% increase in ISA between 2001 and 2011 decreased to 113 (9% of stations). When the 1000 m radius associated with each station was examined, over 52% (over 600) of the stations exhibited an increase in ISA of ⩾20% within at least 1% of the grid cells within that radius. However, as the required area associated with ISA change was increased to ⩾10% the number of stations that were observed with a ⩾20% increase in ISA between 2001 and 2011 decreased to 35 (less than 3% of the stations). The gridded ISA data provides an opportunity to characterize the environment around climate stations with a consistently measured indicator of a surface feature. Periodic evaluations of changes in the ISA near the USHCN and other networks of stations are recommended to assure the local environment around the stations has not significantly changed such that observations at the stations may be impacted.

  2. On the relationship between enamel band complexity and occlusal surface area in Equids (Mammalia, Perissodactyla

    Directory of Open Access Journals (Sweden)

    Nicholas A. Famoso

    2016-07-01

    Full Text Available Enamel patterns on the occlusal surfaces of equid teeth are asserted to have tribal-level differences. The most notable example compares the Equini and Hipparionini, where Equini have higher crowned teeth with less enamel-band complexity and less total occlusal enamel than Hipparionini. Whereas previous work has successfully quantified differences in enamel band shape by dividing the length of enamel band by the square root of the occlusal surface area (Occlusal Enamel Index, OEI, it was clear that OEI only partially removes the effect of body size. Because enamel band length scales allometrically, body size still has an influence on OEI, with larger individuals having relatively longer enamel bands than smaller individuals. Fractal dimensionality (D can be scaled to any level, so we have used it to quantify occlusal enamel complexity in a way that allows us to get at an accurate representation of the relationship between complexity and body size. To test the hypothesis of tribal-level complexity differences between Equini and Hipparionini, we digitally traced a sample of 98 teeth, one tooth per individual; 31 Hipparionini and 67 Equini. We restricted our sampling to the P3-M2 to reduce the effect of tooth position. After calculating the D of these teeth with the fractal box method which uses the number of boxes of various sizes to calculate the D of a line, we performed a t-test on the individual values of D for each specimen, comparing the means between the two tribes, and a phylogenetically informed generalized least squares regression (PGLS for each tribe with occlusal surface area as the independent variable and D as the dependent variable. The slopes of both PGLS analyses were compared using a t-test to determine if the same linear relationship existed between the two tribes. The t-test between tribes was significant (p < 0.0001, suggesting different D populations for each lineage. The PGLS for Hipparionini was a positive but not

  3. Our Reclamation Future: The Missing Bet on Trees.

    Science.gov (United States)

    Ashby, W. Clark; And Others

    This document discusses reclamation alternatives for land that has been surface-mined. Special attention is given to the use of tree planting as a desirable reclamation method. Contents include Illinoian reclamation history, knowledge of forestry techniques and successes on surface-mined lands, recreational and educational use of the reclaimed…

  4. Resistive properties and phase diagram of the organic antiferromagnetic metal κ -(BETS) 2FeCl4

    Science.gov (United States)

    Kunz, Michael; Biberacher, Werner; Kushch, Natalia D.; Miyazaki, Akira; Kartsovnik, Mark V.

    2016-11-01

    The low-temperature electronic state of the layered organic charge-transfer salt κ -(BETS) 2FeCl4 was probed by interlayer electrical resistance measurements under magnetic field. Both above and below TN=0.47 K, the temperature of antiferromagnetic ordering of 3 d -electron spins of Fe3 + localized in the insulating anion layers, a nonsaturating linear R (T ) dependence has been observed. A weak superconducting signal has been detected in the antiferromagnetic state, at temperatures ≤0.2 K. Despite the very high crystal quality, only a tiny fraction of the sample appears to be superconducting. Aside from a small kink feature in the resistivity, the impact of the antiferromagnetic ordering of localized Fe3 + spins on the conduction π -electron system is clearly manifested in the Fermi surface reconstruction, as evidenced by Shubnikov-de Haas oscillations. The "magnetic-field-temperature" phase diagrams for the field directions parallel to each of the three principal crystal axes have been determined. For magnetic field along the easy axis, a spin-flop transition has been found. Similarities and differences between the present material and the sister compound κ -(BETS) 2FeBr4 are discussed.

  5. Spatio-Temporal Modelling of Dust Transport over Surface Mining Areas and Neighbouring Residential Zones

    Directory of Open Access Journals (Sweden)

    Eva Gulikova

    2008-06-01

    Full Text Available Projects focusing on spatio-temporal modelling of the living environment need to manage a wide range of terrain measurements, existing spatial data, time series, results of spatial analysis and inputs/outputs from numerical simulations. Thus, GISs are often used to manage data from remote sensors, to provide advanced spatial analysis and to integrate numerical models. In order to demonstrate the integration of spatial data, time series and methods in the framework of the GIS, we present a case study focused on the modelling of dust transport over a surface coal mining area, exploring spatial data from 3D laser scanners, GPS measurements, aerial images, time series of meteorological observations, inputs/outputs form numerical models and existing geographic resources. To achieve this, digital terrain models, layers including GPS thematic mapping, and scenes with simulation of wind flows are created to visualize and interpret coal dust transport over the mine area and a neighbouring residential zone. A temporary coal storage and sorting site, located near the residential zone, is one of the dominant sources of emissions. Using numerical simulations, the possible effects of wind flows are observed over the surface, modified by natural objects and man-made obstacles. The coal dust drifts with the wind in the direction of the residential zone and is partially deposited in this area. The simultaneous display of the digital map layers together with the location of the dominant emission source, wind flows and protected areas enables a risk assessment of the dust deposition in the area of interest to be performed. In order to obtain a more accurate simulation of wind flows over the temporary storage and sorting site, 3D laser scanning and GPS thematic mapping are used to create a more detailed digital terrain model. Thus, visualization of wind flows over the area of interest combined with 3D map layers enables the exploration of the processes of coal dust

  6. Impacts of urban land-surface forcing on ozone air quality in the Seoul metropolitan area

    Directory of Open Access Journals (Sweden)

    Y.-H. Ryu

    2013-02-01

    Full Text Available Modified local meteorology owing to heterogeneities in the urban–rural surface can affect urban air quality. In this study, the impacts of urban land-surface forcing on ozone air quality during a high ozone (O3 episode in the Seoul metropolitan area, South Korea, are investigated using a high-resolution chemical transport model (CMAQ. Under fair weather conditions, the temperature excess (urban heat island significantly modifies boundary layer characteristics/structures and local circulations. The modified boundary layer and local circulations result in an increase in O3 levels in the urban area of 16 ppb in the nighttime and 13 ppb in the daytime. Enhanced turbulence in the deep urban boundary layer dilutes pollutants such as NOx, and this contributes to the elevated O3 levels through the reduced O3 destruction by NO in the NOx-rich environment. The advection of O3 precursors over the mountains near Seoul by the prevailing valley-breeze circulation in the mid- to late morning results in the build-up of O3 over the mountains in conjunction with biogenic volatile organic compound (BVOC emissions there. As the prevailing local circulation in the afternoon changes to urban-breeze circulation, the O3-rich air masses over the mountains are advected over the urban area. The urban-breeze circulation exerts significant influences on not only the advection of O3 but also the chemical production of O3 under the circumstances in which both anthropogenic and biogenic (natural emissions play important roles in O3 formation. As the air masses that are characterized by low NOx and high BVOC levels and long OH chain length are advected over the urban area from the surroundings, the ozone production efficiency increases in the urban area. The relatively strong vertical mixing in the urban boundary layer embedded in the

  7. Practical split-window algorithm for retrieving land surface temperature over agricultural areas from ASTER data

    Science.gov (United States)

    Wang, Songhan; He, Longhua

    2014-01-01

    A practical split-window algorithm which involves two parameters (transmittance and emissivity) utilized to retrieve land-surface temperature over agricultural areas from the Advanced Spaceborne Thermal Emission and Reflection Radiometer data is presented. First, by calculating the relationship between thermal radiation intensity and temperature, the Planck function is simplified using exponential function which is applied to deduce the split-window algorithm. Second, how to obtain transmittance from water vapor content and the method for estimating emissivity using normalized difference vegetation index are discussed in detail. Sensitivity analysis demonstrates that the algorithm is not sensitive to these two parameters. Finally, a standard atmospheric simulation method has been used to validate the proposed algorithm, and comparison between the algorithm and the prior study has been carried out. The results indicate that the average accuracy is 0.32 K for the case without error in both transmittance and emissivity, which is better than the prior algorithm. The accuracy is also 0.32 K when the transmittance is computed from the water content by piecewise cubic polynomial fit. The accuracy is about 0.30 K˜0.33 K corresponding to different Pv (Pv is the proportion of vegetation) values, which indicates that this algorithm is suitable for different land surface types over agricultural areas.

  8. Porous MgO material with ultrahigh surface area as the matrix for phase change composite

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Yonggan; Shao, Xiankun; Liu, Tongxuan [School of Materials Science and Engineering, Anhui University of Science and Technology, Huainan, Anhui 232001 (China); Li, Benxia, E-mail: libx@mail.ustc.edu.cn [School of Materials Science and Engineering, Anhui University of Science and Technology, Huainan, Anhui 232001 (China); Nie, Shibin, E-mail: nsb@mail.ustc.edu.cn [School of Energy Resources and Safety, Anhui University of Science and Technology, Huainan, Anhui 232001 (China)

    2015-03-20

    Highlights: • Porous MgO material with ultrahigh surface area was synthesized. • A composite PCM was prepared from PEG-1000 and the porous MgO. • The phase change temperatures and enthalpy of the composite were measured. • The composite PCM performed good shape-stabilized property. - Abstract: Mesoporous magnesium oxide (MgO) material was synthesized using an integration of the evaporation-induced surfactant assembly and magnesium nitrate pyrolysis. The as-prepared MgO material is well crystalline, and possesses three-dimensional interconnected mesopores and a surface area as high as 596 m{sup 2}/g. Using the porous MgO as a matrix and polyethylene glycol (PEG-1000) as the functional phase for heat energy storage, a shape-stabilized phase change composite of PEG/MgO was fabricated by an easy impregnation method. In the composite, mesoporous MgO material provides structural strength and prevents the leakage of the molten PEG during the phase change process. The compositions and microstructures of the PEG/MgO composite were determined by Fourier transformation infrared spectroscope (FT-IR), X-ray diffractometer (XRD), scanning electronic microscope (SEM) and thermogravimetric analyzer (TGA), respectively. The phase change properties of the PEG/MgO composite were determined by differential scanning calorimeter (DSC). The high heat-energy storage capability and good thermal stability of the composite enable it extensive applications in the future.

  9. High surface area carbon black (BP-2000) as a reinforcing agent for poly[(₋)-lactide

    Energy Technology Data Exchange (ETDEWEB)

    Delgado, Paula A.; Brutman, Jacob P.; Masica, Kristina; Molde, Joseph; Wood, Brandon; Hillmyer, Marc A. (UMM)

    2016-10-26

    We report that the brittle nature and low-heat distortion resistance of a promising biorenewable thermoplastics, poly((₋)-lactide) (PLA), motivate the investigation of strengthening additives that can address these deficiencies. Here in our work, a high surface area carbon black (BP-2000) as well as biobased carbon blacks (hydrochars) were examined as reinforcement agents for PLA. When 1–5 wt % BP-2000 was added to PLA, the crystallization of PLA was accelerated, resulting in higher crystallinity, tensile strength, and heat resistance. A thermal creep experiment revealed that the composites exhibited no significant deformation after 30 min with 2 N of uniaxial tensile force at 80°C (above the Tg), whereas neat PLA (with similar thermal history) elongated to 79% after 5 min under the same conditions. PLA–hydrochar composites demonstrated similar brittle behavior to neat PLA. Finally, despite the promising nucleating ability of hydrochars, they displayed low interfacial adhesion with PLA because of their low surface area, resulting in poor energy transfer on stretching

  10. Water-bathing synthesis of high-surface-area zeolite P from diatomite

    Institute of Scientific and Technical Information of China (English)

    Yucheng Du; Shuli Shi; Hongxing Dai

    2011-01-01

    Zeolite P was synthesized for the first time via a novel water-bathing route at 90℃ using scrubbed diatomite, sodium hydroxide, and aluminum hydroxide as precursor, with SiO2/Al2O3, SiO2/Na2O, and H2O/Na2O molar ratios of 7.43, 3.81, and 80.00, respectively. The as-fabricated samples were characterized by means of scanning electron microscopy, X-ray diffraction, and nitrogen adsorption measurements. This study showed that (i) treating the diatomite raw material with sodium hexametaphosphate could open the pores in the diatomite via removal of the clay clogged in its pores; (ii) tetragonal mesoporous zeolite P samples with a surface area of 56-60 m2/g could be generated after 6-24 h of water-bathing reaction at 90 C; (iii) extension of water-bathing reaction time could improve the mesoporous structure of zeolite P;and (iv) Ca2+ adsorption capacity of the zeolite P sample was about 300 cmol/kg. Such high-surface-area porous zeolite P could be used as an effective adsorbent for the treatment of water containing calcium and magnesium ions.

  11. Quantifying the effect of waterways and green areas on the surface temperature

    Directory of Open Access Journals (Sweden)

    Elis Dener Lima Alves

    2017-02-01

    Full Text Available The cooling effects of urban parks and green areas, which form the “Park Cool Island” (PCI can help decrease the surface temperature and mitigate the effects of urban heat islands (UHI. Therefore, the objective of this research was to know the temporal variability of PCI intensity, as well as analyze the factors that determines it and propose an equation to predict the PCI intensity in Iporá, Goiás State, Brazil. To this purpose, the PCI intensity values were obtained using the Landsat-8 satellite (band 10, and then correlated with the NDVI and the LAI, in which proposes equations through multiple linear regression to estimate the PCI intensity. The results indicated that: 1 the greater the distance of the natural area, greater the surface temperature; 2 there is a great seasonality in PCI, in which the intensity of PCI is much higher in the spring (or close to it; 3 the relationship between NDVI and LAI variables, showed good coefficients of determination; 4 the equations for the buffer of 200 and 500 m, had low RMSE with high coefficients of determination (r2 = 0.924 and r2 = 0.957 respectively.

  12. Porous boron nitride with a high surface area: hydrogen storage and water treatment.

    Science.gov (United States)

    Li, Jie; Lin, Jing; Xu, Xuewen; Zhang, Xinghua; Xue, Yanming; Mi, Jiao; Mo, Zhaojun; Fan, Ying; Hu, Long; Yang, Xiaojing; Zhang, Jun; Meng, Fanbin; Yuan, Songdong; Tang, Chengchun

    2013-04-19

    We report on the synthesis of high-quality microporous/mesoporous BN material via a facile two-step approach. An extremely high surface area of 1687 m(2) g(-1) and a large pore volume of 0.99 cm(3) g(-1) have been observed in the synthesized BN porous whiskers. The formation of the porous structure was attributed to the group elimination of organic species in a BN precursor, melamine diborate molecular crystal. This elimination method maintained the ordered pore structure and numerous structural defects. The features including high surface area, pore volume and structural defects make the BN whiskers highly suitable for hydrogen storage and wastewater treatment applications. We demonstrate excellent hydrogen uptake capacity of the BN whiskers with high weight adsorption up to 5.6% at room temperature and at the relatively low pressure of 3 MPa. Furthermore, the BN whiskers also exhibit excellent adsorption capacity of methyl orange and copper ions, with the maximum removal capacity of 298.3 and 373 mg g(-1) at 298 K, respectively.

  13. A new synthesis route to high surface area sol gel bioactive glass through alcohol washing

    Science.gov (United States)

    M. Mukundan, Lakshmi; Nirmal, Remya; Vaikkath, Dhanesh; Nair, Prabha D.

    2013-01-01

    Bioactive glass is one of the widely used bone repair material due to its unique properties like osteoconductivity, osteoinductivity and biodegradability. In this study bioactive glass is prepared by the sol gel process and stabilized by a novel method that involves a solvent instead of the conventional calcinations process. This study represents the first attempt to use this method for the stabilization of bioactive glass. The bioactive glass stabilized by this ethanol washing process was characterized for its physicochemical and biomimetic property in comparison with similar composition of calcined bioactive glass. The compositional similarity of the two stabilized glass powders was confirmed by spectroscopic and thermogravimetric analysis. Other physicochemical characterizations together with the cell culture studies with L929 fibroblast cells and bone marrow mesenchymal stem cells proved that the stabilization was achieved with the retention of its inherent bioactive potential. However an increase in the surface area of the glass powder was obtained as a result of this ethanol washing process and this add up to the success of the study. Hence the present study exhibits a promising route for high surface area bioactive glass for increasing biomimicity. PMID:23512012

  14. High-Surface-Area Nitrogen-Doped Reduced Graphene Oxide for Electric Double-Layer Capacitors.

    Science.gov (United States)

    Youn, Hee-Chang; Bak, Seong-Min; Kim, Myeong-Seong; Jaye, Cherno; Fischer, Daniel A; Lee, Chang-Wook; Yang, Xiao-Qing; Roh, Kwang Chul; Kim, Kwang-Bum

    2015-06-08

    A two-step method consisting of solid-state microwave irradiation and heat treatment under NH3 gas was used to prepare nitrogen-doped reduced graphene oxide (N-RGO) with a high specific surface area (1007 m(2)  g(-1) ), high electrical conductivity (1532 S m(-1) ), and low oxygen content (1.5 wt %) for electrical double-layer capacitor applications. The specific capacitance of N-RGO was 291 F g(-1) at a current density of 1 A g(-1) , and a capacitance of 261 F g(-1) was retained at 50 A g(-1) , which indicated a very good rate capability. N-RGO also showed excellent cycling stability and preserved 96 % of the initial specific capacitance after 100 000 cycles. Near-edge X-ray absorption fine-structure spectroscopy results provided evidenced for the recovery of π conjugation in the carbon networks with the removal of oxygenated groups and revealed chemical bonding of the nitrogen atoms in N-RGO. The good electrochemical performance of N-RGO is attributed to its high surface area, high electrical conductivity, and low oxygen content.

  15. Water surface area and depth determine oviposition choice in Aedes albopictus (Diptera: Culicidae).

    Science.gov (United States)

    Reiskind, Michael H; Zarrabi, Ali A

    2012-01-01

    Oviposition choice is a well-studied aspect of the mosquito life cycle, and offers a potential avenue for species-specific surveillance and control. In container inhabiting mosquitoes, there has been a focus on how the components of the aquatic media determine choice, with little work on the physical characteristics of the containers themselves. We performed five experiments examining the effect of physical container parameters on oviposition choice by Aedes albopictus. We examined containers of three different surface areas (small, 496 cm2; medium, 863 cm2; and large, 1,938 cm2) at the same water depth and the same or different heights in a series of binary choice assays. We also examined different depths with the same surface area in clear containers (where the depth may be perceived by the darkness of the water) and in opaque containers, which appear uniformly dark at different depths. We found a significant preference for medium containers over large containers, whether the containers were different or the same heights, and a trend toward a preference for small containers over medium containers. There was a preference for deeper water regardless of whether containers were clear or opaque. These behaviors suggest mosquitoes take into account physical aspects of their habitats and their oviposition choices are consistent with minimizing the risk of habitat drying.

  16. Influence of chemical agents on the surface area and porosity of active carbon hollow fibers

    Directory of Open Access Journals (Sweden)

    LJILJANA M. KLJAJEVIĆ

    2011-09-01

    Full Text Available Active carbon hollow fibers were prepared from regenerated polysulfone hollow fibers by chemical activation using: disodium hydrogen phosphate 2-hydrate, disodium tetraborate 10-hydrate, hydrogen peroxide, and diammonium hydrogen phosphate. After chemical activation fibers were carbonized in an inert atmosphere. The specific surface area and porosity of obtained carbons were studied by nitrogen adsorption–desorption isotherms at 77 K, while the structures were examined with scanning electron microscopy and X-ray diffraction. The activation process increases these adsorption properties of fibers being more pronounced for active carbon fibers obtained with disodium tetraborate 10-hydrate and hydrogen peroxide as activator. The obtained active hollow carbons are microporous with different pore size distribution. Chemical activation with phosphates produces active carbon material with small surface area but with both mesopores and micropores. X-ray diffraction shows that besides turbostratic structure typical for carbon materials, there are some peaks which indicate some intermediate reaction products when sodium salts were used as activating agent. Based on data from the electrochemical measurements the activity and porosity of the active fibers depend strongly on the oxidizing agent applied.

  17. Models for evolution of reactive surface area during dissolution and precipitation

    Science.gov (United States)

    Pedersen, Janne; Jettestuen, Espen; Hildebrand-Habel, Tania; Vinningland, Jan Ludvig; Vadla Madland, Merete; Korsnes, Reidar Inge; Hiorth, Aksel

    2014-05-01

    During water flooding of a reservoir, minerals can dissolve and/or precipitate if the injected water is out of equilibrium with the formation. A net mass transfer between solid and fluid will result in a dynamically changing pore space, which in turn may change the permeability and/or the porosity of the reservoir. When secondary minerals precipitate from solution they will form on top of the primary minerals on the pore walls, and hence the reactive surface area of the individual minerals constituting the porous medium will change. This will in turn affect the dissolution/precipitation rates. In this work we study three different models for the evolution of reactive surface areas during flooding of a core with a brine that is in disequilibrium with the rock. The three models differ in the way secondary minerals are distributed on the solid surface: In model I the whole surface area of both primary and secondary minerals is reactive; hence there will be no screening effect when secondary minerals form. In model II secondary minerals form as a monolayer on the primary minerals that will screen primary minerals from the flow. Model I and II represent two extremes regarding the screening effect; namely no screening (model I) and full screening (model II). Model III is motivated from observations of unflooded and flooded chalk using scanning electron microscopy (SEM). In this model secondary minerals are assumed to form preferentially near crystal defects, being e.g. dislocations in crystallographic pattern or grain contacts. Also the rate of precipitation for forming minerals varies for precipitation onto primary (dissimilar) minerals and precipitation onto secondary (similar) minerals. The three models are implemented into a lattice Boltzmann (LB) based geochemical simulator, and simulation results are compared to results from a 3 years long core flooding experiment with outcrop chalk flooded with 0.219M MgCl2 at 130°C, as well as SEM studies. Before flooding 98wt

  18. Preparation of High-Surface Area Nano-CeO2 by Template-Assisted Precipitation Method

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The high-surface area nano-CeO2 was prepared by Ce(NO3)3 by precipitation method, with surfactant cetyltrimethyl ammonium bromide (CTAB) as templating agent. The effects of the precipitating agents, reaction temperature, ageing time, and calcination temperature on the surface area, as well as the pore structure and the mean crystallite size of nano-CeO2 were studied. It was found that the reaction of Ce(NO3)3 with NaOH in the presence of CTAB at 90 ℃ for 12 h yieldsed a cerium oxide/surfactant mixture, which after calcination at 400 ℃ resulted in high-surface area nano-CeO2. The mean crystallite size of CeO2 was approximately 6 nm, surface area was in excess of 200 m2·g-1, pore size was approximately 9 nm, and the pore distribution was concentrative. Moreover, the surface area can still reach 147 m2·g-1 after calcination at 700 ℃, which showed the good thermal stability of the CeO2. The number of oxygen vacancies in the structure of CeO2 corresponded with the surface area of CeO2, and the high surface area was propitious to the formation of oxygen vacancies.

  19. Automatic mapping of urban areas from Landsat data using impervious surface fraction algorithm

    Science.gov (United States)

    Nguyen, S. T.; Chen, C. F.; Chen, C. R.

    2014-12-01

    Urbanization is a result of aggregation of people in urban areas that can help advance socioeconomic development and pull out people from the poverty line. However, if not monitored well, it can also lead to loss of farmlands, natural forests as well as to societal impacts including burgeoning growth of slums, pollution, and crime. Thus, spatiotemporal information that shapes the urbanization is thus critical to the process of urban planning. The overall objective of this study is to develop an impervious surface fraction algorithm (ISFA) for automatically mapping urban areas from Landsat data. We processed the data for 1986, 2001 and 2014 to trace the multi-decadal spatiotemporal change of Honduran capital city using a three-step procedure: (1) data pre-processing to perform image normalization as well as to produce the difference in the values (DVSS) between the simple ratio (SR) of green and shortwave bands and the soil adjust vegetation index (SAVI), (2) quantification of urban areas using ISFA, and (3) accuracy assessment of mapping results using the ground reference data constructed using land-cover maps and FORMOSAT-2 imagery. The mapping accuracy assessment was performed for 2001 and 2014 by comparing with the ground reference data indicated satisfactory results with the overall accuracies and Kappa coefficients generally higher than 90% and 0.8, respectively. When examining the urbanization between these years, it could be observed that the urban area was significantly expanded from 1986 to 2014, mainly driven by two factors of rapid population growth and socioeconomic development. This study eventually leads to a realization of the merit of using ISFA for multi-decadal monitoring of the urbanization of Honduran capital city from Landsat data. Results from this research can be used by urban planners as a general indicator to quantify urban change and environmental impacts. The methods were thus transferable to monitor urban growth in cities and their peri

  20. Surface area changes of Himalayan ponds as a proxy of hydrological climate-driven fluctuations

    Science.gov (United States)

    Salerno, Franco; Thakuri, Sudeep; Guyennon, Nicolas; Viviano, Gaetano; Tartari, Gianni

    2016-04-01

    The meteorological measurements at high-elevations of the Himalayan range are scarce due to the harsh conditions of these environments which limit the suitable maintenance of weather stations. As a consequence, the meager knowledge on how the climate is changed in the last decades at Himalayan high-elevations sets a serious limit upon the interpretation of relationships between causes and recent observed effects on the cryosphere. Although the glaciers masses reduction in Himalaya is currently sufficiently well described, how changes in climate drivers (precipitation and temperature) have influenced the melting and shrinkage processes are less clear. Consequently, the uncertainty related to the recent past amplifies when future forecasts are done, both for climate and impacts. In this context, a substantial body of research has already demonstrated the high sensitivity of lakes and ponds to climate. Some climate-related signals are highly visible and easily measurable in lakes. For example, climate-driven fluctuations in lake surface area have been observed in many remote sites. On interior Tibetan Plateau the lake growth since the late 1990s is mainly attributed to increased regional precipitation and weakened evaporation. Differently, other authors attribute at the observed increases of lake surfaces at the enhanced glacier melting. In our opinion these divergences found in literature are due to the type of glacial lakes considered in the study and in particular their relationship with glaciers. In general, in Himalaya three types of glacial lakes can be distinguished: (i) lakes that are not directly connected with glaciers, but that may have a glacier located in their basin (unconnected glacial lakes); (ii) supraglacial lakes, which develop on the surface of the glacier downstream; or (iii) proglacial lakes, which are moraine-dammed lakes that are in contact with the glacier front. Some of these lakes store large quantities of water and are susceptible to GLOFs

  1. New model for estimating the relationship between surface area and volume in the human body using skeletal remains.

    Science.gov (United States)

    Kasabova, Boryana E; Holliday, Trenton W

    2015-04-01

    A new model for estimating human body surface area and body volume/mass from standard skeletal metrics is presented. This model is then tested against both 1) "independently estimated" body surface areas and "independently estimated" body volume/mass (both derived from anthropometric data) and 2) the cylindrical model of Ruff. The model is found to be more accurate in estimating both body surface area and body volume/mass than the cylindrical model, but it is more accurate in estimating body surface area than it is for estimating body volume/mass (as reflected by the standard error of the estimate when "independently estimated" surface area or volume/mass is regressed on estimates derived from the present model). Two practical applications of the model are tested. In the first test, the relative contribution of the limbs versus the trunk to the body's volume and surface area is compared between "heat-adapted" and "cold-adapted" populations. As expected, the "cold-adapted" group has significantly more of its body surface area and volume in its trunk than does the "heat-adapted" group. In the second test, we evaluate the effect of variation in bi-iliac breadth, elongated or foreshortened limbs, and differences in crural index on the body's surface area to volume ratio (SA:V). Results indicate that the effects of bi-iliac breadth on SA:V are substantial, while those of limb lengths and (especially) the crural index are minor, which suggests that factors other than surface area relative to volume are driving morphological variation and ecogeographical patterning in limb prorportions.

  2. Experimental Study on the Microstructure Evolution of Mixed Disposal Paste in Surface Subsidence Areas

    Directory of Open Access Journals (Sweden)

    Wei Sun

    2016-05-01

    Full Text Available The integrated disposal of surface subsidence pits and surface solid waste can be realized by backfilling a surface subsidence area with a paste made from the solid wastes of mines, such as tailings and waste rock. The microstructures of these wastes determine the macroscopic properties of a paste backfill. This paper presents an experimental study on the internal structure evolution of pasty fluid mixed with different waste rock concentrations (10%, 30%, and 50% and cement dosages (1% and 2% under damage. To this end, a real-time computed tomography (CT scan is conducted using medical CT and a small loading device. Results show that UCS (uniaxial compressive strength increases when the amount of cement increases. Given a constant amount of cement, UCS increases first and then decreases as waste rock content increases. UCS is maximized at 551 kPa when the waste rock content is 30%. The paste body is a typical medium used to investigate initial damage, which mainly consists of microholes, pores, and microcracks. The initial damages also exhibit a high degree of random inhomogeneity. After loading, cracks are initiated and expand gradually from the original damage location until the overall damages are generated. The mesostructure evolution model of the paste body is divided into six categories, and this mesostructure is reasonable when the waste rock content is 30%.

  3. Diversity of Bacterial Communities of Fitness Center Surfaces in a U.S. Metropolitan Area

    Directory of Open Access Journals (Sweden)

    Nabanita Mukherjee

    2014-12-01

    Full Text Available Public fitness centers and exercise facilities have been implicated as possible sources for transmitting community-acquired bacterial infections. However, the overall diversity of the bacterial community residing on the surfaces in these indoor environments is still unknown. In this study, we investigated the overall bacterial ecology of selected fitness centers in a metropolitan area (Memphis, TN, USA utilizing culture-independent pyrosequencing of the 16S rRNA genes. Samples were collected from the skin-contact surfaces (e.g., exercise instruments, floor mats, handrails, etc. within fitness centers. Taxonomical composition revealed the abundance of Firmicutes phyla, followed by Proteobacter and Actinobacteria, with a total of 17 bacterial families and 25 bacterial genera. Most of these bacterial genera are of human and environmental origin (including, air, dust, soil, and water. Additionally, we found the presence of some pathogenic or potential pathogenic bacterial genera including Salmonella, Staphylococcus, Klebsiella, and Micrococcus. Staphylococcus was found to be the most prevalent genus. Presence of viable forms of these pathogens elevates risk of exposure of any susceptible individuals. Several factors (including personal hygiene, surface cleaning and disinfection schedules of the facilities may be the reasons for the rich bacterial diversity found in this study. The current finding underscores the need to increase public awareness on the importance of personal hygiene and sanitation for public gym users.

  4. Synthetic microfluidic paper: high surface area and high porosity polymer micropillar arrays.

    Science.gov (United States)

    Hansson, Jonas; Yasuga, Hiroki; Haraldsson, Tommy; van der Wijngaart, Wouter

    2016-01-21

    We introduce Synthetic Microfluidic Paper, a novel porous material for microfluidic applications that consists of an OSTE polymer that is photostructured in a well-controlled geometry of slanted and interlocked micropillars. We demonstrate the distinct benefits of Synthetic Microfluidic Paper over other porous microfluidic materials, such as nitrocellulose, traditional paper and straight micropillar arrays: in contrast to straight micropillar arrays, the geometry of Synthetic Microfluidic Paper was miniaturized without suffering capillary collapse during manufacturing and fluidic operation, resulting in a six-fold increased internal surface area and a three-fold increased porous fraction. Compared to commercial nitrocellulose materials for capillary assays, Synthetic Microfluidic Paper shows a wider range of capillary pumping speed and four times lower device-to-device variation. Compared to the surfaces of the other porous microfluidic materials that are modified by adsorption, Synthetic Microfluidic Paper contains free thiol groups and has been shown to be suitable for covalent surface chemistry, demonstrated here for increasing the material hydrophilicity. These results illustrate the potential of Synthetic Microfluidic Paper as a porous microfluidic material with improved performance characteristics, especially for bioassay applications such as diagnostic tests.

  5. Forward-looking Assimilation of MODIS-derived Snow Covered Area into a Land Surface Model

    Science.gov (United States)

    Zaitchik, Benjamin F.; Rodell, Matthew

    2008-01-01

    Snow cover over land has a significant impact on the surface radiation budget, turbulent energy fluxes to the atmosphere, and local hydrological fluxes. For this reason, inaccuracies in the representation of snow covered area (SCA) within a land surface model (LSM) can lead to substantial errors in both offline and coupled simulations. Data assimilation algorithms have the potential to address this problem. However, the assimilation of SCA observations is complicated by an information deficit in the observation SCA indicates only the presence or absence of snow, and not snow volume and by the fact that assimilated SCA observations can introduce inconsistencies with atmospheric forcing data, leading to non-physical artifacts in the local water balance. In this paper we present a novel assimilation algorithm that introduces MODIS SCA observations to the Noah LSM in global, uncoupled simulations. The algorithm utilizes observations from up to 72 hours ahead of the model simulation in order to correct against emerging errors in the simulation of snow cover while preserving the local hydrologic balance. This is accomplished by using future snow observations to adjust air temperature and, when necessary, precipitation within the LSM. In global, offline integrations, this new assimilation algorithm provided improved simulation of SCA and snow water equivalent relative to open loop integrations and integrations that used an earlier SCA assimilation algorithm. These improvements, in turn, influenced the simulation of surface water and energy fluxes both during the snow season and, in some regions, on into the following spring.

  6. Topographic Effects on the Surface Emissivity of a Mountainous Area Observed by a Spaceborne Microwave Radiometer

    Directory of Open Access Journals (Sweden)

    Frank S. Marzano

    2008-03-01

    Full Text Available A simulation study to understand the influence of topography on the surfaceemissivity observed by a satellite microwave radiometer is carried out. We analyze theeffects due to changes in observation angle, including the rotation of the polarization plane.A mountainous area in the Alps (Northern Italy is considered and the information on therelief extracted from a digital elevation model is exploited. The numerical simulation refersto a radiometric image, acquired by a conically-scanning radiometer similar to AMSR-E,i.e., flying at 705 km of altitude with an observation angle of 55°. To single out the impacton surface emissivity, scattering of the radiation due to the atmosphere or neighboringelevated surfaces is not considered. C and X bands, for which atmospheric effects arenegligible, and Ka band are analyzed. The results indicate that the changes in the localobservation angle tend to lower the apparent emissivity of a radiometric pixel with respectto the corresponding flat surface characteristics. The effect of the rotation of thepolarization plane enlarges (vertical polarization, or attenuates (horizontal polarizationthis decrease. By doing some simplifying assumptions for the radiometer antenna, theconclusion is that the microwave emissivity at vertical polarization is underestimated,whilst the opposite occurs for horizontal polarization, except for Ka band, for which bothunder- and overprediction may occur. A quantification of the differences with respect to aflat soil and an approximate evaluation of their impact on soil moisture retrieval areyielded.

  7. Energy storage on ultrahigh surface area activated carbon fibers derived from PMIA.

    Science.gov (United States)

    Castro-Muñiz, Alberto; Suárez-García, Fabián; Martínez-Alonso, Amelia; Tascón, Juan M D; Kyotani, Takashi

    2013-08-01

    High-performance carbon materials for energy storage applications have been obtained by using poly(m-phenylene isophthalamide), PMIA, as a precursor through the chemical activation of the carbonized aramid fiber by using KOH. The yield of the process of activation was remarkably high (25-40 wt%), resulting in activated carbon fibers (ACFs) with ultrahigh surface areas, over 3000 m(2) g(-1) , and pore volumes exceeding 1.50 cm(3) g(-1) , keeping intact the fibrous morphology. The porous structure and the surface chemical properties could easily be controlled through the conditions of activation. The PMIA-derived ACFs were tested in two types of energy storage applications. At -196 °C and 1 bar, H2 uptake values of approximately 3 t% were obtained, which, in combination with the textural properties, rendered it a good candidate for H2 adsorption at high pressure and temperature. The performance of the ACFs as electrodes for electrochemical supercapacitors was also investigated. Specific capacitance values between 297 and 531 g(-1) at 50 mA g(-1) were obtained in aqueous electrolyte (1 H2 SO4 ), showing different behaviors depending on the surface chemical properties.

  8. Joint Geophysical Imaging of the Utah Area Using Seismic Body Waves, Surface Waves and Gravity Data

    Science.gov (United States)

    Zhang, H.; Maceira, M.; Toksoz, M. N.; Burlacu, R.; Yang, Y.

    2009-12-01

    We present a joint geophysical imaging method that makes use of seismic body wave arrival times, surface wave dispersion measurements, and gravity data to determine three-dimensional (3D) Vp and Vs models. An empirical relationship mapping densities to Vp and Vs for earth materials is used to link them together. The joint inversion method takes advantage of strengths of individual data sets and is able to better constrain the velocity models from shallower to greater depths. Combining three different data sets to jointly invert for the velocity structure is equivalent to a multiple-objective optimization problem. Because it is unlikely that the different “objectives” (data types) would be optimized by the same parameter choices, some trade-off between the objectives is needed. The optimum weighting scheme for different data types is based on relative uncertainties of individual observations and their sensitivities to model parameters. We will apply this joint inversion method to determine 3D Vp and Vs models of the Utah area. The seismic body wave arrival times are assembled from waveform data recorded by the University of Utah Seismograph Stations (UUSS) regional network for the past 7 years. The surface wave dispersion measurements are obtained from the ambient noise tomography study by the University of Colorado group using EarthScope/USArray stations. The gravity data for the Utah area is extracted from the North American Gravity Database managed by the University of Texas at El Paso. The preliminary study using the seismic body wave arrival times indicates strong low velocity anomalies in middle crust beneath some known geothermal sites in Utah. The joint inversion is expected to produce a reasonably well-constrained velocity structure of the Utah area, which is helpful for characterizing and exploring existing and potential geothermal reservoirs.

  9. Groundwater Impacts on Urban Surface Water Quality in the Lowland Polder Catchments of the Amsterdam City Area

    Science.gov (United States)

    Rozemeijer, J.; Yu, L.; Van Breukelen, B. M.; Broers, H. P.

    2015-12-01

    Surface water quality in the Amsterdam area is suffering from high nutrient levels. The sources and transport mechanisms of these nutrients are unclear due to the complex hydrology of the highly manipulated urban and sub-urban polder catchments. This study aimed at identifying the impact of groundwater on surface water quality in the polder catchments of the greater Amsterdam city area. Therefore, we exploited the dense groundwater and surface water monitoring networks to explain spatial patterns in surface water chemistry and their relations with landscape characteristics and groundwater impact. We selected and statistically analyzed 23 variables for 144 polders, covering a total area of 700 km2. Our dataset includes concentrations of total-N, total-P, ammonium, nitrate, bicarbonate, sulfate, calcium, and chloride in surface water and groundwater, seepage rate, elevation, paved area percentage, surface water area percentage, and soil type (calcite, humus and clay percentages). Our results show that nutrient levels in groundwater were generally much higher than in surface water and often exceeded the surface water Environmental Quality Standards (EQSs). This indicates that groundwater is a large potential source of nutrients in surface water. High correlations (R2 up to 0.88) between solutes in both water compartments and close similarities in their spatial patterns confirmed the large impact of groundwater on surface water quality. Groundwater appeared to be a major source of chloride, bicarbonate and calcium in surface water and for N and P, leading to exceeding of EQSs in surface waters. In dry periods, the artificial redistribution of excess seepage water from deep polders to supply water to infiltrating polders further distributes the N and P loads delivered by groundwater over the area.

  10. Effect of Grinding Process Parameters on Surface Area Roughness of Glass fibre Reinforced Composite Laminate under Dry and Coolant Environment

    Directory of Open Access Journals (Sweden)

    P. Chockalingam

    2016-04-01

    Full Text Available This paper presents a comparative study on dry and wet grinding of chopped strand mat glass fibre reinforced polymer laminates using an alumina wheel. Investigations were performed to study the impact of the grinding parameters, namely feed, speed, and depth of cut on grinding force ratio and surface area roughness. Effective grinding parameters were sought in this study to maximize grinding force ratio and minimize surface area roughness. Test results show that coolant helped to decrease surface area roughness, but inevitably reduced the grinding force ratio in some cases. These findings lead to economic machining solution for optimum grinding conditions in grinding composite laminates.

  11. Study of near-surface layers of Omerelu area using low velocity layer (LVL method

    Directory of Open Access Journals (Sweden)

    Ajani, O.O.

    2013-03-01

    Full Text Available It is important that we have good knowledge of the soil type so as to appreciate the enormous resources we are stepping on. It is more compelling for oil explorationists to know more as this will go a long way to determine the success or failure of search for minerals. Seismic methods give a good overview of a wide area though they involve greater logistics and operational requirements than some other geophysical methods. The purpose of present study is to determine the depth of the weathered layer and velocities of near-surface layers over the investigated area. Twelve sample points were picked with a grid system spread over a perimeter of approximately 4km x 4km. The in-house UpSphere computer program was utilised to analyse and display result in a way that makes final interpretation very easy. This program actually removed the burden of plotting the graphs and the contour maps manually. The depth of weathered layer in the study area varies between 12m and 13m. The velocities of the weathered layer and the consolidated layer vary between 500 m/s – 550 m/s and 1790 m/s – 1875 m/s respectively. Also the dip is in the north east – south west direction.

  12. Parasitic contamination of surface and deep soil in different areas of Sari in north of Iran

    Institute of Scientific and Technical Information of China (English)

    Hajar Ziaei Hezarjaribi; Ahmad Daryani; Nastaran Amani Kelarijani; Mina Eskandari Shahraki; Beheshteh Haghparast Kenari; Mohammad Saaid Dayer; Najla Hamidianfar; Fatemeh Ghaffarifar

    2016-01-01

    Objective:To study the parasitic contamination of soil in selected areas of Sari, north of Iran. Methods: A cross-sectional study was conducted to identify all available parasites in surface and deep soil. In this study 580 soil samples (278 deep soil and 302 topsoil samples) from 21 different locations were collected from pathways, parks, greenhouses, estates around the city, cemetery, main squares, farmlands, fenced gardens and seashores. Depending on the soil type, two samples were prepared, from surface and deep soil at the depth of 3 to 5 cm. After performing various stages of preparation, including cleaning and washing, smoothing and flotation, parasitic elements were examined microscopically and quantitative parasite counting was done using a McMaster slide. Results:The results showed that the highest rate of parasitic contamination was related to nematodes larvae (26.11%). Other contaminants such asEntamoeba andAcanthamoeba cysts, vacuolizationBlastocystis hominis form, oocyte containing sporocysts,Toxascaris eggs, nematoda larvae,Hymenolepis eggs,Ascaris eggs,Fasciola eggs, hookworm eggs,Toxocara eggs, insects' larvae and other ciliated and flagellated organisms were also observed. The results of this study showed that the highest contamination was found in public garden (25.80%) both in surface (29.30%) and in deep soil (21.12%), while the lowest level of contamination was observed in seashore surface soil (4.90%). Conclusions:The results showed that soil can provide a potential medium for the spread of soil transmitted parasitic diseases in the environment; therefore, preventive programs are needed.

  13. Water and Carbon Dioxide Ices-Rich Areas on Comet 67P/CG Nucleus Surface

    Science.gov (United States)

    Filacchione, G.; Capaccioni, F.; Raponi, A.; De Sanctis, M. C.; Ciarniello, M.; Barucci, M. A.; Tosi, F.; Migliorini, A.; Capria, M. T.; Erard, S.; Bockelée-Morvan, D.; Leyrat, C.; Arnold, G.; Kappel, D.; McCord, T. B.

    2017-01-01

    So far, only two ice species have been identified by Rosetta/VIRTIS-M [1] on the surface of 67P/Churyumov-Gerasimenko during the pre-perihelion time: crystalline water and carbon dioxide ice. Water ice has been spectroscopically identified in three distinct modalities: 1) On the active areas of Hapi region where water ice changes its abundance with local time and illumination conditions, condensing during the night hours and sublimating during daytime [2]; 2) On recent debris fields collapsed from two elevated structures in the Imhotep region where more fresh and pristine material is exposed [3]; 3) On eight bright areas located in Khonsu, Imhotep, Anhur, Atum and Khepry regions [4] where single or multiple grouped icy patches with sizes ranging between few meters to about 60 m are observed. Carbon dioxide ice has been detected only in a 60-80 m area in Anhur region while it was exiting from a four year-long winter-night season [5]. This ice deposit underwent a rapid sublimation, disappearing in about one month after its initial detection. While water and carbon dioxide ice appear always mixed with the ubiquitous dark material [6,7], there are no evidences of the presence of water and carbon dioxide ices mixed together in the same area. If observed, ices always account for very small fraction (few percent) with respect to the dark material. Moreover, the surface ice deposits are preferentially located on the large lobe and the neck while they are absent on the small lobe. Apart from these differences in the spatial distribution of ices on the surface, a large variability is observed the mixing modalities and in the grain size distributions, as retrieved from spectral modeling [8]: 1) very small μm-sized water ice grains in intimate mixing with the dark terrain are detected on Hapi active regions [2]; 2) two monodispersed distributions with maxima at 56 μm and at 2 mm, corresponding to the intimate and areal mixing classes, are observedon the Imhotep debris

  14. Surface modification of CNTs and enhanced photocatalytic activity of TiO{sub 2} coated on hydrophilically modified CNTs

    Energy Technology Data Exchange (ETDEWEB)

    Yang Hanpei, E-mail: yanghanpei@hhu.edu.cn [Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098 (China); Wu Sha; Duan Yunping; Fu Xiaofei; Wu Junming [Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098 (China)

    2012-01-15

    A new method to enhance photocatalytic performance of TiO{sub 2} by dispersing it onto hydrophilically surface modified carbon nanotubes is reported. The hydrophilically surface functionalized CNTs and as prepared composite CNTs-TiO{sub 2} photocatalysts were characterized using FT-IR, XPS, XRD, BET adsorption analysis and TEM. The composite samples were evaluated for their photocatalytic activity toward the degradation of methyl orange in aqueous solution under both UV and visible light irradiation. The results indicated that the hydrophilic functional groups were grafted covalently on the surface of CNTs successfully, and the functionalized CNTs exhibit higher BET specific surface area and aquatic solubility. The improved photocatalytic activity of CNTs-TiO{sub 2} was mainly attributed to the high dispersion of TiO{sub 2} on CNTs and the intimate contact between TiO{sub 2} and CNTs resulting in dense heterojunctions at the interface of TiO{sub 2} and CNTs.

  15. Component Ratios of Independent and Herding Betters in a Racetrack Betting Market

    CERN Document Server

    Mori, Shintaro

    2010-01-01

    We study the time series data of the racetrack betting market in the Japan Racing Association (JRA). As the number of votes t increases, the win bet fraction x(t) converges to the final win bet fraction x_{f}. We observe the power law $(x(t)-x_{f})^{2} \\propto t^{-\\beta}$ with $\\beta\\simeq 0.488$. We measure the degree of the completeness of the ordering of the horses using an index AR, the horses are ranked according to the size of the win bet fraction. AR(t) also obeys the power law and behaves as $\\mbox{AR}_{f}-\\mbox{AR}(t)\\propto t^{-\\gamma}$ with $\\gamma\\simeq 0.589$, where AR_{f} is the final value of AR. We introduce a simple voting model with two types of voters-independent and herding. Independent voters provide information about the winning probability of the horses and herding voters decide their votes based on the popularities of the horses.This model can explain two power laws of the betting process. The component ratio of the independent voter to the herding voter is 1:3.

  16. The BET Family of Proteins Targets Moloney Murine Leukemia Virus Integration near Transcription Start Sites

    Directory of Open Access Journals (Sweden)

    Jan De Rijck

    2013-11-01

    Full Text Available A hallmark of retroviral replication is integration of the viral genome into host cell DNA. This characteristic makes retrovirus-based vectors attractive delivery vehicles for gene therapy. However, adverse events in gene therapeutic trials, caused by activation of proto-oncogenes due to murine leukemia virus (MLV-derived vector integration, hamper their application. Here, we show that bromodomain and extraterminal (BET proteins (BRD2, BRD3, and BRD4 and MLV integrase specifically interact and colocalize within the nucleus of the cell. Inhibition of the BET proteins’ chromatin interaction via specific bromodomain inhibitors blocks MLV virus replication at the integration step. MLV integration site distribution parallels the chromatin binding profile of BET proteins, and expression of an artificial fusion protein of the BET integrase binding domain with the chromatin interaction domain of the lentiviral targeting factor LEDGF/p75 retargets MLV integration away from transcription start sites and into the body of actively transcribed genes, conforming to the HIV integration pattern. Together, these data validate BET proteins as MLV integration targeting factors.

  17. MASS TRANSFER LIMITATION IN DIFFERENT ANODE ELECTRODE SURFACE AREAS ON THE PERFORMANCE OF DUAL CHAMBER MICROBIAL FUEL CELL

    Directory of Open Access Journals (Sweden)

    Majid Sadeqzadeh

    2012-01-01

    Full Text Available In this study, the effect of different electrode surface areas on the performance of dual chamber Microbial Fuel Cells (MFC was investigated. Four different electrodes with 12, 16, 20 and 24 cm2 surface areas were tested in an MFC system. The 20 cm2 electrode generated an output power of 76.5 mW/m2 was found to be the highest among all the electrodes tested. This might be due to better interactions with microorganism and less mass transfer limitation. In addition, this indicates that the chances for attachment of bacteria and generation of electricity in larger electrode surface areas might be limited by mass transport and by higher surface area. The output power generation was then followed by the 16, 12 and 24 cm2 electrodes which generated 69.6, 64.7 and 61.25 mW/m2 electricity, respectively.

  18. Nickel catalysts supported on MgO with different specific surface area for carbon dioxide reforming of methane

    Institute of Scientific and Technical Information of China (English)

    Luming; Zhang; Lin; Li; Yuhua; Zhang; Yanxi; Zhao; Jinlin; Li

    2014-01-01

    In this paper, three kinds of MgO with different specific surface area were prepared, and their effects on the catalytic performance of nickel catalysts for the carbon dioxide reforming of methane were investigated. The results showed that MgO support with the higher specific surface area led to the higher dispersion of the active metal, which resulted in the higher initial activity. On the other hand, the specific surface area of MgO materials might not be the dominant factor for the basicity of support to chemisorb and activate CO2, which was another important factor for the performance of catalysts. Herein, Ni/MgO(CA) catalyst with proper specific surface area and strong ability to activate CO2exhibited stable catalytic property and the carbon species deposited on the Ni/MgO(CA) catalyst after 10 h of reaction at 650 ?C were mainly activated carbon species.

  19. Preparation and Characterization of Highly Spherical Silica-titania Aerogel Beads with High Surface Area

    Directory of Open Access Journals (Sweden)

    YU Yu-xi

    2017-02-01

    Full Text Available The silica-titania aerogel beads were synthesized through sol-gel reaction followed by supercritical drying, in which TEOS and TBT as co-precursors, EtOH as solvents, HAC and NH3·H2O as catalysts. The as-prepared aerogel beads were characterized by SEM,TEM,XRD,FT-IR,TG-DTA and nitrogen adsorption-desorption. The results indicate that the diameter distribution of beads are between 1-8mm, the average diameter of beads is 3.5mm. The aerogel beads have nanoporous network structure with high specific surface area of 914.5m2/g, and the TiO2 particles are distributed in the aerogel uniformly, which keep the anatase crystal under high temperature.

  20. Macrostructure-dependent photocatalytic property of high-surface-area porous titania films

    Directory of Open Access Journals (Sweden)

    T. Kimura

    2014-11-01

    Full Text Available Porous titania films with different macrostructures were prepared with precise control of condensation degree and density of the oxide frameworks in the presence of spherical aggregates of polystyrene-block-poly(oxyethylene (PS-b-PEO diblock copolymer. Following detailed explanation of the formation mechanisms of three (reticular, spherical, and large spherical macrostructures by the colloidal PS-b-PEO templating, structural variation of the titania frameworks during calcination were investigated by X-ray diffraction and X-ray photoelectron spectroscopy. Then, photocatalytic performance of the macroporous titania films was evaluated through simple degradation experiments of methylene blue under an UV irradiation. Consequently, absolute surface area of the film and crystallinity of the titania frameworks were important for understanding the photocatalytic performance, but the catalytic performance can be improved further by the macrostructural design that controls diffusivity of the targeted molecules inside the film and their accessibility to active sites.

  1. Printed Large-Area Single-Mode Photonic Crystal Bandedge Surface-Emitting Lasers on Silicon.

    Science.gov (United States)

    Zhao, Deyin; Liu, Shihchia; Yang, Hongjun; Ma, Zhenqiang; Reuterskiöld-Hedlund, Carl; Hammar, Mattias; Zhou, Weidong

    2016-01-04

    We report here an optically pumped hybrid III-V/Si photoic crystal surface emitting laser (PCSEL), consisting of a heterogeneously integrated III-V InGaAsP quantum well heterostructure gain medium, printed on a patterned defect-free Si photonic crystal (PC) bandedge cavity. Single mode lasing was achieved for a large area laser, with a side-mode suppression ratio of 28 dB, for lasing operation temperature ~ 200 K. Two types of lasers were demonstrated operating at different temperatures. Detailed modal analysis reveals the lasing mode matches with the estimated lasing gain threshold conditions. Our demonstration promises a hybrid laser sources on Si towards three-dimensional (3D) integrated Si photonics for on-chip wavelength-division multiplex (3D WDM) systems for a wide range of volume photonic/electronic applications in computing, communication, sensing, imaging, etc.

  2. Fast and Accurate Accessible Surface Area Prediction Without a Sequence Profile.

    Science.gov (United States)

    Faraggi, Eshel; Kouza, Maksim; Zhou, Yaoqi; Kloczkowski, Andrzej

    2017-01-01

    A fast accessible surface area (ASA) predictor is presented. In this new approach no residue mutation profiles generated by multiple sequence alignments are used as inputs. Instead, we use only single sequence information and global features such as single-residue and two-residue compositions of the chain. The resulting predictor is both highly more efficient than sequence alignment based predictors and of comparable accuracy to them. Introduction of the global inputs significantly helps achieve this comparable accuracy. The predictor, termed ASAquick, is found to perform similarly well for so-called easy and hard cases indicating generalizability and possible usability for de-novo protein structure prediction. The source code and a Linux executables for ASAquick are available from Research and Information Systems at http://mamiris.com and from the Battelle Center for Mathematical Medicine at http://mathmed.org .

  3. Dynamic Development of Regional Cortical Thickness and Surface Area in Early Childhood.

    Science.gov (United States)

    Lyall, Amanda E; Shi, Feng; Geng, Xiujuan; Woolson, Sandra; Li, Gang; Wang, Li; Hamer, Robert M; Shen, Dinggang; Gilmore, John H

    2015-08-01

    Cortical thickness (CT) and surface area (SA) are altered in many neuropsychiatric disorders and are correlated with cognitive functioning. Little is known about how these components of cortical gray matter develop in the first years of life. We studied the longitudinal development of regional CT and SA expansion in healthy infants from birth to 2 years. CT and SA have distinct and heterogeneous patterns of development that are exceptionally dynamic; overall CT increases by an average of 36.1%, while cortical SA increases 114.6%. By age 2, CT is on average 97% of adult values, compared with SA, which is 69%. This suggests that early identification, prevention, and intervention strategies for neuropsychiatric illness need to be targeted to this period of rapid postnatal brain development, and that SA expansion is the principal driving factor in cortical volume after 2 years of age.

  4. High specific surface area Mo2C nanoparticles as an efficient electrocatalyst for hydrogen evolution

    Science.gov (United States)

    Tang, Chaoyun; Sun, Aokui; Xu, Yushuai; Wu, Zhuangzhi; Wang, Dezhi

    2015-11-01

    Mo2C nanoparticles with high specific surface area (120 m2 g-1) are successfully synthesized using a typical and low-cost monosaccharide of glucose via a facile calcination and subsequent reduction process. The HER functions of the obtained Mo2C nanoparticles are investigated and the effect of reduction time in hydrogen is also discussed. It is found that η-MoC can be obtained at 800 °C with a reduction time of 10 min, but the formation of β-Mo2C phase requires more than 20 min. Moreover, the β-Mo2C obtained with a reduction time of 20 min exhibits the best HER activity with a small Tafel slope of 55 mV dec-1 and a large current density of 60 mA cm-2 at -200 mV, which is among the best records over Mo2C-based HER catalysts.

  5. Soil Specific Surface Area and Non-Singularity of Soil-Water Retention at Low Saturations

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Tuller, Markus; Møldrup, Per

    2013-01-01

    The dry end of the soil water characteristic (SWC) is important for modeling vapor flow dynamics and predicting soil properties such as specific surface area (SSA) and clay content (CL). Verification of new instrumentation for rapid measurement of the dry end of the SWC is relevant to avoid long...... equilibration times and potential for hydraulic decoupling. The objectives of this study were to measure both adsorption and desorption branches of the dry end of the SWC for 21 variably-textured Arizona soils using new, fully automated instrumentation (AquaSorp); apply the data to parameterize the Tuller...... comparable to SSAEGME for all soils. The matric potential at “zero” water content was confirmed as the widely accepted value of around –800 MPa. A non-singularity coefficient based on water adsorption at monolayer coverage was positively correlated with CL. Obtained results show the potential of the Aqua...

  6. Method for the preparation of high surface area high permeability carbons

    Science.gov (United States)

    Lagasse, R.R.; Schroeder, J.L.

    1999-05-11

    A method for preparing carbon materials having high surface area and high macropore volume to provide high permeability. These carbon materials are prepared by dissolving a carbonizable polymer precursor, in a solvent. The solution is cooled to form a gel. The solvent is extracted from the gel by employing a non-solvent for the polymer. The non-solvent is removed by critical point drying in CO{sub 2} at an elevated pressure and temperature or evaporation in a vacuum oven. The dried product is heated in an inert atmosphere in a first heating step to a first temperature and maintained there for a time sufficient to substantially cross-link the polymer material. The cross-linked polymer material is then carbonized in an inert atmosphere. 3 figs.

  7. Method for the preparation of high surface area high permeability carbons

    Energy Technology Data Exchange (ETDEWEB)

    Lagasse, Robert R. (Albuquerque, NM); Schroeder, John L. (Albuquerque, NM)

    1999-05-11

    A method for preparing carbon materials having high surface area and high macropore volume to provide high permeability. These carbon materials are prepared by dissolving a carbonizable polymer precursor, in a solvent. The solution is cooled to form a gel. The solvent is extracted from the gel by employing a non-solvent for the polymer. The non-solvent is removed by critical point drying in CO.sub.2 at an elevated pressure and temperature or evaporation in a vacuum oven. The dried product is heated in an inert atmosphere in a first heating step to a first temperature and maintained there for a time sufficient to substantially cross-link the polymer material. The cross-linked polymer material is then carbonized in an inert atmosphere.

  8. Data on the role of accessible surface area on osmolytes-induced protein stabilization

    Directory of Open Access Journals (Sweden)

    Safikur Rahman

    2017-02-01

    Full Text Available This paper describes data related to the research article “Testing the dependence of stabilizing effect of osmolytes on the fractional increase in the accessible surface area on thermal and chemical denaturations of proteins” [1]. Heat- and guanidinium chloride (GdmCl-induced denaturation of three disulfide free proteins (bovine cytochrome c (b-cyt-c, myoglobin (Mb and barstar in the presence of different concentrations of methylamines (sarcosine, glycine-betaine (GB and trimethylamine-N-oxide (TMAO was monitored by [ϴ]222, the mean residue ellipticity at 222 nm at pH 7.0. Methylamines belong to a class of osmolytes known to protect proteins from deleterious effect of urea. This paper includes comprehensive thermodynamic data obtained from the heat- and GdmCl-induced denaturations of barstar, b-cyt-c and Mb.

  9. Macrostructure-dependent photocatalytic property of high-surface-area porous titania films

    Science.gov (United States)

    Kimura, T.

    2014-11-01

    Porous titania films with different macrostructures were prepared with precise control of condensation degree and density of the oxide frameworks in the presence of spherical aggregates of polystyrene-block-poly(oxyethylene) (PS-b-PEO) diblock copolymer. Following detailed explanation of the formation mechanisms of three (reticular, spherical, and large spherical) macrostructures by the colloidal PS-b-PEO templating, structural variation of the titania frameworks during calcination were investigated by X-ray diffraction and X-ray photoelectron spectroscopy. Then, photocatalytic performance of the macroporous titania films was evaluated through simple degradation experiments of methylene blue under an UV irradiation. Consequently, absolute surface area of the film and crystallinity of the titania frameworks were important for understanding the photocatalytic performance, but the catalytic performance can be improved further by the macrostructural design that controls diffusivity of the targeted molecules inside the film and their accessibility to active sites.

  10. FreeSASA: An open source C library for solvent accessible surface area calculations.

    Science.gov (United States)

    Mitternacht, Simon

    2016-01-01

    Calculating solvent accessible surface areas (SASA) is a run-of-the-mill calculation in structural biology. Although there are many programs available for this calculation, there are no free-standing, open-source tools designed for easy tool-chain integration. FreeSASA is an open source C library for SASA calculations that provides both command-line and Python interfaces in addition to its C API. The library implements both Lee and Richards' and Shrake and Rupley's approximations, and is highly configurable to allow the user to control molecular parameters, accuracy and output granularity. It only depends on standard C libraries and should therefore be easy to compile and install on any platform. The library is well-documented, stable and efficient. The command-line interface can easily replace closed source legacy programs, with comparable or better accuracy and speed, and with some added functionality.

  11. Environmental protection management by monitoring the surface water quality in Semenic area

    Directory of Open Access Journals (Sweden)

    Dana SÂMBOTIN

    2011-08-01

    Full Text Available Environment seems to have been the war against all. In fact recently most people polluted the environment and those few are cared for his cleaning. Today, the relationship evolvedas societies have changed in favour of ensuring environmental protection. With modern technology, performance, monitoring the environment becomes part of human activity ever more necessary, more possible and more efficient. The quality of the environment, its components: air, water, soil, plants, vegetable and animal products, is a condition "sine qua non" for the life of the modern man. The consequences of environmental pollution areso dangerous that modern man cannot afford considering them. Through this paper I will study the environmental quality by monitoring the surfaces waters from the Semenic- Gărâna area.

  12. High surface area ThO.sub.2 catalyst and method of preparing it

    Science.gov (United States)

    Colmenares, Carlos A.; Somorjai, Gabor A.; Maj, Joseph J.

    1985-01-01

    A ThO.sub.2 catalyst having a high surface area of about 80-125 m.sup.2 /g is synthesized. The compound is synthesized by simultaneously mixing an aqueous solution of ThNO.sub.3 (NO.sub.3).sub.4.4H.sub.2 O with an aqueous solution of Na.sub.2 CO.sub.3.H.sub.2 O, to produce a solution and solid ThOCO.sub.3. The solid ThOCO.sub.3 is separated from the solution, and then calcined at a temperature of about 225.degree.-300.degree. C. for about 40-55 hours to produce ThO.sub.2. The ThO.sub.2 catalyst produced includes Na present as a substitutional cation in an amount equal to about 5-10 atom percent.

  13. Sterols as biomarkers in the surface microlayer of the estuarine areas.

    Science.gov (United States)

    Alsalahi, Murad Ali; Latif, Mohd Talib; Ali, Masni Mohd; Dominick, Doreena; Khan, Md Firoz; Mustaffa, Nur Ili Hamizah; Nadzir, Mohd Shahrul Mohd; Nasher, Essam; Zakaria, Mohamad Pauzi

    2015-04-15

    This study aims to determine the concentration of sterols used as biomarkers in the surface microlayer (SML) in estuarine areas of the Selangor River, Malaysia. Samples were collected during different seasons through the use of a rotation drum. The analysis of sterols was performed using gas chromatography equipped with a flame ionisation detector (GC-FID). The results showed that the concentrations of total sterols in the SML ranged from 107.06 to 505.55 ng L(-1). The total sterol concentration was found to be higher in the wet season. Cholesterol was found to be the most abundant sterols component in the SML. The diagnostic ratios of sterols show the influence of natural sources and waste on the contribution of sterols in the SML. Further analysis, using principal component analysis (PCA), showed distinct inputs of sterols derived from human activity (40.58%), terrigenous and plant inputs (22.59%) as well as phytoplankton and marine inputs (17.35%).

  14. N,N-Dilauryl Chitosan:Synthesis and Surface Pressure-area Isotherm

    Institute of Scientific and Technical Information of China (English)

    XIN Mei-hua; WANG Min; LI Ming-chun; LIU Chao; SUN Duo-xian; MITSUISHI Masaya; MIYASHITA Tokuji

    2004-01-01

    With sodium dodecyl sulfonate(SDS) as the phase transferring catalyst, N,N-Dilauryl chitosans with a high degree of alkyl group substitution were prepared and characterized by means of FTIR, 1H NMR and elemental analyses. The results indicate that the average degree of alkyl group substitution on the chitosan increases with decreasing the molecular weight of the chitosan. The fully N,N-dilaurylated chitosan was found to be dissolvable in chloroform. The collapsed pressures of the samples derived from chitosan with 3000,5000 and 10000 dalton are 47.6, 48.2 and 51.0 mN/m, respectively. The surface area occupied by the monomer unit (glucosamine) of all those samples is 0.6 nm2.

  15. Lithium inclusion in indium metal-organic frameworks showing increased surface area and hydrogen adsorption

    Directory of Open Access Journals (Sweden)

    Mathieu Bosch

    2014-12-01

    Full Text Available Investigation of counterion exchange in two anionic In-Metal-Organic Frameworks (In-MOFs showed that partial replacement of disordered ammonium cations was achieved through the pre-synthetic addition of LiOH to the reaction mixture. This resulted in a surface area increase of over 1600% in {Li [In(1,3 − BDC2]}n and enhancement of the H2 uptake of approximately 275% at 80 000 Pa at 77 K. This method resulted in frameworks with permanent lithium content after repeated solvent exchange as confirmed by inductively coupled plasma mass spectrometry. Lithium counterion replacement appears to increase porosity after activation through replacement of bulkier, softer counterions and demonstrates tuning of pore size and properties in MOFs.

  16. A STUDY ON THE CHARACTERISTICS OF INTERNAL AND EXTERNAL WALL SURFACE TEMPERATURE IN THE URBAN AREA

    Institute of Scientific and Technical Information of China (English)

    何云玲; 张一平; 刘玉洪; 马友鑫; 李佑荣; 窦军霞; 郭萍

    2004-01-01

    Internal and external wall surface temperatures (Tws) in April, August and December in Kunming, a city in low latitude plateau, were investigated. Results showed that the Tws in April were of the highest among the three, followed by August and December. The Tws differences among walls with different orientation were higher in April and December when the weather tends to be sunny, and lower in August with more cloudy days in the time. In April and August, Tws of E-wall was the highest, followed by S- and N-wall. But in December Tws of S-wall might be sometimes higher than E one. Diurnal range of internal Tws was usually smaller than that of the external, with also a time lag for the occurrence of its maximum and minimum. The results can serve as a basis for further research on building microclimate and urban architecture designs. It also gives suggestions for similar studies in other areas.

  17. Alterations in cell surface area and deformability of individual human red blood cells in stored blood

    CERN Document Server

    Park, HyunJoo; Lee, SangYun; Kim, Kyoohyun; Sohn, Yong-Hak; Jang, Seongsoo; Park, YongKeun

    2015-01-01

    The functionality and viability of stored human red blood cells (RBCs) is an important clinical issue in transfusion. To systematically investigate changes in stored whole blood, the hematological properties of individual RBCs were quantified in blood samples stored for various periods with and without a preservation solution called CPDA-1. With 3-D quantitative phase imaging techniques, the optical measurements of the 3-D refractive index (RI) distributions and membrane fluctuations were done at the individual cell level. From the optical measurements, the morphological (volume, surface area and sphericity), biochemical (hemoglobin content and concentration), and mechanical parameters (dynamic membrane fluctuation) were simultaneously quantified to investigate the functionalities and their progressive alterations in stored RBCs. Our results show that the stored RBCs without CPDA-1 had a dramatic morphological transformation from discocytes to spherocytes within 2 weeks which was accompanied with significant ...

  18. High surface area activated carbon prepared from cassava peel by chemical activation.

    Science.gov (United States)

    Sudaryanto, Y; Hartono, S B; Irawaty, W; Hindarso, H; Ismadji, S

    2006-03-01

    Cassava is one of the most important commodities in Indonesia, an agricultural country. Cassava is one of the primary foods in our country and usually used for traditional food, cake, etc. Cassava peel is an agricultural waste from the food and starch processing industries. In this study, this solid waste was used as the precursor for activated carbon preparation. The preparation process consisted of potassium hydroxide impregnation at different impregnation ratio followed by carbonization at 450-750 degrees C for 1-3 h. The results revealed that activation time gives no significant effect on the pore structure of activated carbon produced, however, the pore characteristic of carbon changes significantly with impregnation ratio and carbonization temperature. The maximum surface area and pore volume were obtained at impregnation ratio 5:2 and carbonization temperature 750 degrees C.

  19. Albedo and land surface temperature shift in hydrocarbon seepage potential area, case study in Miri Sarawak Malaysia

    Science.gov (United States)

    Suherman, A.; Rahman, M. Z. A.; Busu, I.

    2014-02-01

    The presence of hydrocarbon seepage is generally associated with rock or mineral alteration product exposures, and changes of soil properties which manifest with bare development and stress vegetation. This alters the surface thermodynamic properties, changes the energy balance related to the surface reflection, absorption and emission, and leads to shift in albedo and LST. Those phenomena may provide a guide for seepage detection which can be recognized inexpensively by remote sensing method. District of Miri is used for study area. Available topographic maps of Miri and LANDSAT ETM+ were used for boundary construction and determination albedo and LST. Three land use classification methods, namely fixed, supervised and NDVI base classifications were employed for this study. By the intensive land use classification and corresponding statistical comparison was found a clearly shift on albedo and land surface temperature between internal and external seepage potential area. The shift shows a regular pattern related to vegetation density or NDVI value. In the low vegetation density or low NDVI value, albedo of internal area turned to lower value than external area. Conversely in the high vegetation density or high NDVI value, albedo of internal area turned to higher value than external area. Land surface temperature of internal seepage potential was generally shifted to higher value than external area in all of land use classes. In dense vegetation area tend to shift the temperature more than poor vegetation area.

  20. Transport and retention of phosphorus in surface water in an urban slum area

    Directory of Open Access Journals (Sweden)

    P. M. Nyenje

    2013-08-01

    Full Text Available The transport of excessive phosphorus (P discharged from unsewered informal settlements (slums due to poor on-site sanitation is largely unknown. Hence, we investigated the processes governing P transport in a 28 km2 slum-dominated catchment in Kampala, Uganda. During high runoff events and a period of base flow, we collected hourly water samples (over 24 h from a primary channel draining the catchment and from a small size tertiary channel draining one of the contributing slum areas (0.5 km2. Samples were analyzed for orthophosphate (PO4-P, particulate P (PP, total P (TP and selected hydro-chemical parameters. Channel bed and suspended sediments were collected to determine their sorption potential, geo-available metals and dominant P forms. We found that P inputs in the catchment originated mainly from domestic wastewater as evidenced by high concentrations of Cl (36–144 mg L-1, HCO3 and other cations in the channels. Most P discharged during low flow conditions was particulate implying that much of it was retained in bed sediments. Retained P was mostly bound to Ca and Fe/Al oxides. Hence, we inferred that mineral precipitation and adsorption to Ca-minerals were the dominant P retention processes. Bed sediments were P-saturated and showed a tendency to release P to discharging waters. P released was likely due to Ca-bound P because of the strong correlation between Ca and total P in sediments (r2 = 0.9. High flows exhibited a strong flush of PP and SS implying that part of P retained was frequently flushed out of the catchment by surface erosion and resuspension of bed sediment. Our findings suggest that P accumulated in the channel bed during low flows and then was slowly released into surface water. Hence, it will likely take some time, even with improved wastewater management practices, before P loads to downstream areas can be significantly reduced.

  1. Transport and retention of phosphorus in surface water in an urban slum area

    Science.gov (United States)

    Nyenje, P. M.; Meijer, L. M. G.; Foppen, J. W.; Kulabako, R.; Uhlenbrook, S.

    2013-08-01

    The transport of excessive phosphorus (P) discharged from unsewered informal settlements (slums) due to poor on-site sanitation is largely unknown. Hence, we investigated the processes governing P transport in a 28 km2 slum-dominated catchment in Kampala, Uganda. During high runoff events and a period of base flow, we collected hourly water samples (over 24 h) from a primary channel draining the catchment and from a small size tertiary channel draining one of the contributing slum areas (0.5 km2). Samples were analyzed for orthophosphate (PO4-P), particulate P (PP), total P (TP) and selected hydro-chemical parameters. Channel bed and suspended sediments were collected to determine their sorption potential, geo-available metals and dominant P forms. We found that P inputs in the catchment originated mainly from domestic wastewater as evidenced by high concentrations of Cl (36-144 mg L-1), HCO3 and other cations in the channels. Most P discharged during low flow conditions was particulate implying that much of it was retained in bed sediments. Retained P was mostly bound to Ca and Fe/Al oxides. Hence, we inferred that mineral precipitation and adsorption to Ca-minerals were the dominant P retention processes. Bed sediments were P-saturated and showed a tendency to release P to discharging waters. P released was likely due to Ca-bound P because of the strong correlation between Ca and total P in sediments (r2 = 0.9). High flows exhibited a strong flush of PP and SS implying that part of P retained was frequently flushed out of the catchment by surface erosion and resuspension of bed sediment. Our findings suggest that P accumulated in the channel bed during low flows and then was slowly released into surface water. Hence, it will likely take some time, even with improved wastewater management practices, before P loads to downstream areas can be significantly reduced.

  2. Synthesis of High Surface Area Alumina Aerogels without the Use of Alkoxide Precursors

    Energy Technology Data Exchange (ETDEWEB)

    Baumann, T F; Gash, A E; Chinn, S C; Sawvel, A M; Maxwell, R S; Satcher Jr., J H

    2004-06-25

    Alumina aerogels were prepared through the addition of propylene oxide to aqueous or ethanolic solutions of hydrated aluminum salts, AlCl{sub 3} {center_dot} 6H{sub 2}O or Al(NO{sub 3}){sub 3} {center_dot} 9H{sub 2}O, followed by drying with supercritical CO{sub 2}. This technique affords low-density (60-130 kg/m{sup 3}), high surface area (600-700 m{sup 2}/g) alumina aerogel monoliths without the use of alkoxide precursors. The dried alumina aerogels were characterized using elemental analysis, high-resolution transmission electron microscopy, powder X-ray diffraction, solid state NMR, acoustic measurements and nitrogen adsorption/desorption analysis. Powder X-ray diffraction and TEM analysis indicated that the aerogel prepared from hydrated AlCl{sub 3} in water or ethanol possessed microstructures containing highly reticulated networks of pseudoboehmite fibers, 2-5 nm in diameter and of varying lengths, while the aerogels prepared from hydrated Al(NO{sub 3}){sub 3} in ethanol were amorphous with microstructures comprised of interconnected spherical particles with diameters in the 5-15 nm range. The difference in microstructure resulted in each type of aerogel displaying distinct physical and mechanical properties. In particular, the alumina aerogels with the weblike microstructure were far more mechanically robust than those with the colloidal network, based on acoustic measurements. Both types of alumina aerogels can be transformed to {gamma}-Al{sub 2}O{sub 3} through calcination at 800 C without a significant loss in surface area or monolithicity.

  3. 30 CFR 785.19 - Surface coal mining and reclamation operations on areas or adjacent to areas including alluvial...

    Science.gov (United States)

    2010-07-01

    ..., and evapotranspiration, relief, slope and density of drainage channels; (B) Factors contributing to... coal mining operation may affect this alluvial valley floor or waters that supply the alluvial valley... alluvial valley floor that would be affected by the surface coal mining operation is of such small...

  4. Maintaining solvent accessible surface area under rotamer substitution for protein design.

    Science.gov (United States)

    Leaver-Fay, Andrew; Butterfoss, Glenn L; Snoeyink, Jack; Kuhlman, Brian

    2007-06-01

    Although quantities derived from solvent accessible surface areas (SASA) are useful in many applications in protein design and structural biology, the computational cost of accurate SASA calculation makes SASA-based scores difficult to integrate into commonly used protein design methodologies. We demonstrate a method for maintaining accurate SASA during a Monte Carlo search of sequence and rotamer space for a fixed protein backbone. We extend the fast Le Grand and Merz algorithm (Le Grand and Merz, J Comput Chem, 14, 349), which discretizes the solvent accessible surface for each atom by placing dots on a sphere and combines Boolean masks to determine which dots are exposed. By replacing semigroup operations with group operations (from Boolean logic to counting dot coverage) we support SASA updates. Our algorithm takes time proportional to the number of atoms affected by rotamer substitution, rather than the number of atoms in the protein. For design simulations with a one hundred residue protein our approach is approximately 145 times faster than performing a Le Grand and Merz SASA calculation from scratch following each rotamer substitution. To demonstrate practical effectiveness, we optimize a SASA-based measure of protein packing in the complete redesign of a large set of proteins and protein-protein interfaces.

  5. Calculation of distribution coefficients in the SAMPL5 challenge from atomic solvation parameters and surface areas

    Science.gov (United States)

    Santos-Martins, Diogo; Fernandes, Pedro Alexandrino; Ramos, Maria João

    2016-11-01

    In the context of SAMPL5, we submitted blind predictions of the cyclohexane/water distribution coefficient (D) for a series of 53 drug-like molecules. Our method is purely empirical and based on the additive contribution of each solute atom to the free energy of solvation in water and in cyclohexane. The contribution of each atom depends on the atom type and on the exposed surface area. Comparatively to similar methods in the literature, we used a very small set of atomic parameters: only 10 for solvation in water and 1 for solvation in cyclohexane. As a result, the method is protected from overfitting and the error in the blind predictions could be reasonably estimated. Moreover, this approach is fast: it takes only 0.5 s to predict the distribution coefficient for all 53 SAMPL5 compounds, allowing its application in virtual screening campaigns. The performance of our approach (submission 49) is modest but satisfactory in view of its efficiency: the root mean square error (RMSE) was 3.3 log D units for the 53 compounds, while the RMSE of the best performing method (using COSMO-RS) was 2.1 (submission 16). Our method is implemented as a Python script available at https://github.com/diogomart/SAMPL5-DC-surface-empirical.

  6. Development and Testing of High Surface Area Iridium Anodes for Molten Oxide Electrolysis

    Science.gov (United States)

    Shchetkovskiy, Anatoliy; McKechnie, Timothy; Sadoway, Donald R.; Paramore, James; Melendez, Orlando; Curreri, Peter A.

    2010-01-01

    Processing of lunar regolith into oxygen for habitat and propulsion is needed to support future space missions. Direct electrochemical reduction of molten regolith is an attractive method of processing, because no additional chemical reagents are needed. The electrochemical processing of molten oxides requires high surface area, inert anodes. Such electrodes need to be structurally robust at elevated temperatures (1400-1600?C), be resistant to thermal shock, have good electrical conductivity, be resistant to attack by molten oxide (silicate), be electrochemically stable and support high current density. Iridium with its high melting point, good oxidation resistance, superior high temperature strength and ductility is the most promising candidate for anodes in high temperature electrochemical processes. Several innovative concepts for manufacturing such anodes by electrodeposition of iridium from molten salt electrolyte (EL-Form? process) were evaluated. Iridium electrodeposition to form of complex shape components and coating was investigated. Iridium coated graphite, porous iridium structure and solid iridium anodes were fabricated. Testing of electroformed iridium anodes shows no visible degradation. The result of development, manufacturing and testing of high surface, inert iridium anodes will be presented.

  7. Study of transverse crack formation on surface area of UO{sub 2} pellet circumference

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Dionisia S.; Paneto, Lelia F.P.C.; Souza, Patricia O. de, E-mail: dionisia@inb.gov.br, E-mail: lelia@inb.gov.br, E-mail: patriciasouza@inb.gov.br [Industrias Nucleares do Brasil (INB), Resende, RJ (Brazil). Gerencia de Analise Tecnica do Combustivel Nuclear

    2013-07-01

    Microstructure of a polycrystalline material has a considerable influence on particular properties, such as mechanical strength, electrical conductivity, optical transmission and magnetic susceptibility. The uranium dioxide (UO{sub 2}) is used in water-cooled nuclear reactors, due to its desirable ceramics characteristics as a nuclear fuel. The UO{sub 2} is used in the form of pellets manufactured by wet route by INB, where they are loaded into fuel rods to build the fuel assemblies used in pressurized water reactors of Angra 1, Angra 2 and future Angra 3 nuclear power plants, for electric energy generated from nuclear power in Brazil. The geometric and structural integrity of these pellets cause direct influence on their performance during the reactor core operating cycle, so pellets presenting surface cracks leading to the phenomenon of pellet cladding interaction-PCI, resulting in failures in the fuel rod and subsequently release of fission products in the reactor coolant. Transverse cracks on surface area of pellet circumference are detected by visual inspection during the manufacturing process. This paper presents the study of these cracks formation by content analysis conducted with the support of electron microscopy. These results here are analyzed from the point of view of materials science through observation of the microstructure, and the pressing process where the defect was probably generated. (author)

  8. Eddy formation and surface flow field in the Luzon Strait area during the summer of 2009

    Science.gov (United States)

    Liu, Ze; Hou, Yijun; Xie, Qiang

    2015-09-01

    The formation of mesoscale eddies and the structure of the surface flow field in the Luzon Strait area were examined using in-situ CTD data, Argo float data, and multi-satellite remote sensing data collected from May to August 2009. The results show that vigorous water exchange between Kuroshio water and South China Sea (SCS) water began to emerge over the 200 m water column throughout the strait. Based on an objective definition of surface currents, float A69 tracked an anti-cyclonic eddy southwest of Taiwan Island under a Lagrangian current measurement. The salinity inside the anti-cyclonic eddy was higher than in typical SCS water but lower than in Kuroshio mainstream water, indicating that this eddy was induced by Kuroshio frontal intrusion through the Luzon Strait and into the SCS. From hydrographic data, we propose that continuous horizontal diffusion with high-salinity characteristics in the subsurface layer could extend to 119°E or even further west. The high-temperature filament, large positive sea level anomaly and clockwise geostrophic current all confirmed the existence of this warm eddy in May and June. A strongly negative wind stress curl maintained the eddy until it died. The surface flow field during July and August was rather complicated. Float A83 described an east-west orientated shuttle run in the 20°N section that was not reported by previous studies. At the same time, float A80 indicated a Kuroshio bend into the north-central region of Luzon Strait but it did not cross 120.5°E. The water mass rejoining the Kuroshio mainstream from the southern tip of Taiwan Island was less saline, indicating an entrainment of water from SCS by the Kuroshio bend.

  9. Self-assembled large-area annular cavity arrays with tunable cylindrical surface plasmons for sensing.

    Science.gov (United States)

    Ni, Haibin; Wang, Ming; Shen, Tianyi; Zhou, Jing

    2015-02-24

    Surface plasmons that propagate along cylindrical metal/dielectric interfaces in annular apertures in metal films, called cylindrical surface plasmons (CSPs), exhibit attractive optical characteristics. However, it is challenging to fabricate these nanocoaxial structures. Here, we demonstrate a practical low-cost route to manufacture highly ordered, large-area annular cavity arrays (ACAs) that can support CSPs with great tunability. By employing a sol-gel coassembly method, reactive ion etching and metal sputtering techniques, regular, highly ordered ACAs in square-centimeter-scale with a gap width tunable in the range of several to hundreds of nanometers have been produced with good reproducibility. Ag ACAs with a gap width of 12 nm and a gap height of 635 nm are demonstrated. By finite-difference time-domain simulation, we confirm that the pronounced dips in the reflectance spectra of ACAs are attributable to CSP resonances excited in the annular gaps. By adjusting etching time and Ag film thickness, the CSP dips can be tuned to sweep the entire optical range of 360 to 1800 nm without changing sphere size, which makes them a promising candidate for forming integrated plasmonic sensing arrays. The high tunability of the CSP resonant frequencies together with strong electric field enhancement in the cavities make the ACAs promising candidates for surface plasmon sensors and SERS substrates, as, for example, they have been used in liquid refractive index (RI) sensing, demonstrating a sensitivity of 1505 nm/RIU and a figure of merit of 9. One of the CSP dips of ACAs with a certain geometry size is angle- (0-70 degrees) and polarization-independent and can be used as a narrow-band absorber. Furthermore, the nano annular cavity arrays can be used to construct solar cells, nanolasers and nanoparticle plasmonic tweezers.

  10. The Genetic Association Between Neocortical Volume and General Cognitive Ability Is Driven by Global Surface Area Rather Than Thickness.

    Science.gov (United States)

    Vuoksimaa, Eero; Panizzon, Matthew S; Chen, Chi-Hua; Fiecas, Mark; Eyler, Lisa T; Fennema-Notestine, Christine; Hagler, Donald J; Fischl, Bruce; Franz, Carol E; Jak, Amy; Lyons, Michael J; Neale, Michael C; Rinker, Daniel A; Thompson, Wesley K; Tsuang, Ming T; Dale, Anders M; Kremen, William S

    2015-08-01

    Total gray matter volume is associated with general cognitive ability (GCA), an association mediated by genetic factors. It is expectable that total neocortical volume should be similarly associated with GCA. Neocortical volume is the product of thickness and surface area, but global thickness and surface area are unrelated phenotypically and genetically in humans. The nature of the genetic association between GCA and either of these 2 cortical dimensions has not been examined. Humans possess greater cognitive capacity than other species, and surface area increases appear to be the primary driver of the increased size of the human cortex. Thus, we expected neocortical surface area to be more strongly associated with cognition than thickness. Using multivariate genetic analysis in 515 middle-aged twins, we demonstrated that both the phenotypic and genetic associations between neocortical volume and GCA are driven primarily by surface area rather than thickness. Results were generally similar for each of 4 specific cognitive abilities that comprised the GCA measure. Our results suggest that emphasis on neocortical surface area, rather than thickness, could be more fruitful for elucidating neocortical-GCA associations and identifying specific genes underlying those associations.

  11. The Genetic Association Between Neocortical Volume and General Cognitive Ability Is Driven by Global Surface Area Rather Than Thickness

    Science.gov (United States)

    Vuoksimaa, Eero; Panizzon, Matthew S.; Chen, Chi-Hua; Fiecas, Mark; Eyler, Lisa T.; Fennema-Notestine, Christine; Hagler, Donald J.; Fischl, Bruce; Franz, Carol E.; Jak, Amy; Lyons, Michael J.; Neale, Michael C.; Rinker, Daniel A.; Thompson, Wesley K.; Tsuang, Ming T.; Dale, Anders M.; Kremen, William S.

    2015-01-01

    Total gray matter volume is associated with general cognitive ability (GCA), an association mediated by genetic factors. It is expectable that total neocortical volume should be similarly associated with GCA. Neocortical volume is the product of thickness and surface area, but global thickness and surface area are unrelated phenotypically and genetically in humans. The nature of the genetic association between GCA and either of these 2 cortical dimensions has not been examined. Humans possess greater cognitive capacity than other species, and surface area increases appear to be the primary driver of the increased size of the human cortex. Thus, we expected neocortical surface area to be more strongly associated with cognition than thickness. Using multivariate genetic analysis in 515 middle-aged twins, we demonstrated that both the phenotypic and genetic associations between neocortical volume and GCA are driven primarily by surface area rather than thickness. Results were generally similar for each of 4 specific cognitive abilities that comprised the GCA measure. Our results suggest that emphasis on neocortical surface area, rather than thickness, could be more fruitful for elucidating neocortical–GCA associations and identifying specific genes underlying those associations. PMID:24554725

  12. Surface-area-controlled synthesis of porous TiO2 thin films for gas-sensing applications

    Science.gov (United States)

    Park, Jae Young; Kim, Ho-hyoung; Rana, Dolly; Jamwal, Deepika; Katoch, Akash

    2017-03-01

    Surface-area-controlled porous TiO2 thin films were prepared via a simple sol–gel chemical route, and their gas-sensing properties were thoroughly investigated in the presence of typical oxidizing NO2 gas. The surface area of TiO2 thin films was controlled by developing porous TiO2 networked by means of controlling the TiO2-to-TTIP (titanium isopropoxide, C12H28O4Ti) molar ratio, where TiO2 nanoparticles of size ∼20 nm were used. The sensor’s response was found to depend on the surface area of the TiO2 thin films. The porous TiO2 thin-film sensor with greater surface area was more sensitive than those of TiO2 thin films with lesser surface area. The improved sensing ability was ascribed to the porous network formed within the thin films by TiO2 sol. Our results show that surface area is a key parameter for obtaining superior gas-sensing performance; this provides important guidelines for preparing and using porous thin films for gas-sensing applications.

  13. Surface-area-controlled synthesis of porous TiO2 thin films for gas-sensing applications.

    Science.gov (United States)

    Park, Jae Young; Kim, Ho-Hyoung; Rana, Dolly; Jamwal, Deepika; Katoch, Akash

    2017-03-03

    Surface-area-controlled porous TiO2 thin films were prepared via a simple sol-gel chemical route, and their gas-sensing properties were thoroughly investigated in the presence of typical oxidizing NO2 gas. The surface area of TiO2 thin films was controlled by developing porous TiO2 networked by means of controlling the TiO2-to-TTIP (titanium isopropoxide, C12H28O4Ti) molar ratio, where TiO2 nanoparticles of size ∼20 nm were used. The sensor's response was found to depend on the surface area of the TiO2 thin films. The porous TiO2 thin-film sensor with greater surface area was more sensitive than those of TiO2 thin films with lesser surface area. The improved sensing ability was ascribed to the porous network formed within the thin films by TiO2 sol. Our results show that surface area is a key parameter for obtaining superior gas-sensing performance; this provides important guidelines for preparing and using porous thin films for gas-sensing applications.

  14. Area inequalities for stable marginally outer trapped surfaces in Einstein-Maxwell-dilaton theory

    CERN Document Server

    Fajman, David

    2013-01-01

    We prove area inequalities for stable marginally outer trapped surfaces in Einstein-Maxwell-dilaton theory. Our inspiration comes on the one hand from a corresponding recent upper bound for the area in terms of the charges obtained by Dain, Jaramillo and Reiris [1] in the pure Einstein-Maxwell case without symmetries, and on the other hand from Yazadjiev's inequality [2] in the axially symmetric Einstein-Maxwell-dilaton case. The common issue in these proofs and in the present one is a functional ${\\mathscr W}$ of the matter fields for which the stability condition readily yields an {\\it upper} bound. On the other hand, the step which crucially depends on whether or not a dilaton field is present is to obtain a {\\it lower} bound for ${\\mathscr W}$ as well. We obtain the latter by first setting up a variational principle for ${\\mathscr W}$ with respect to the dilaton field $\\phi$, then by proving existence of a minimizer $\\psi$ as solution of the corresponding Euler-Lagrange equations and finally by estimating...

  15. Diurnal variation of surface ozone in mountainous areas: Case study of Mt. Huang, East China.

    Science.gov (United States)

    Zhang, Lei; Jin, Lianji; Zhao, Tianliang; Yin, Yan; Zhu, Bin; Shan, Yunpeng; Guo, Xiaomei; Tan, Chenghao; Gao, Jinhui; Wang, Haoliang

    2015-12-15

    To explore the variations in atmospheric environment over mountainous areas, measurements were made from an intensive field observation at the summit of Mt. Huang (30.13°N, 118.15°E, 1841m above sea level), a rural site located in East China, from June to August 2011. The measurements revealed a diurnal change of surface O3 with low concentrations during the daytime and high concentrations during the nighttime. The causes of diurnal O3 variations over the mountain peak in East China were investigated by using a fairly comprehensive WRF-Chem and HYSPLIT4 modeling approach with observational analysis. By varying model inputs and comparing the results to a baseline modeling and actual air quality observations, it is found that nearby ozone urban/anthropogenic emission sources were contributing to a nighttime increase in mountaintop ozone levels due to a regional transport lag and residual layer effects. Positive correlation of measured O3 and CO concentrations suggested that O3 was associated with anthropogenic emissions. Sensitivity modeling experiments indicated that local anthropogenic emissions had little impact on the diurnal pattern of O3. The diurnal pattern of O3 was mainly influenced by regional O3 transport from the surrounding urban areas located 100-150km away from the summit, with a lag time of 10h for transport.

  16. Representation of Glossy Material Surface in Ventral Superior Temporal Sulcal Area of Common Marmosets

    Science.gov (United States)

    Miyakawa, Naohisa; Banno, Taku; Abe, Hiroshi; Tani, Toshiki; Suzuki, Wataru; Ichinohe, Noritaka

    2017-01-01

    The common marmoset (Callithrix jacchus) is one of the smallest species of primates, with high visual recognition abilities that allow them to judge the identity and quality of food and objects in their environment. To address the cortical processing of visual information related to material surface features in marmosets, we presented a set of stimuli that have identical three-dimensional shapes (bone, torus or amorphous) but different material appearances (ceramic, glass, fur, leather, metal, stone, wood, or matte) to anesthetized marmoset, and recorded multiunit activities from an area ventral to the superior temporal sulcus (STS) using multi-shanked, and depth resolved multi-electrode array. Out of 143 visually responsive multiunits recorded from four animals, 29% had significant main effect only of the material, 3% only of the shape and 43% of both the material and the shape. Furthermore, we found neuronal cluster(s), in which most cells: (1) showed a significant main effect in material appearance; (2) the best stimulus was a glossy material (glass or metal); and (3) had reduced response to the pixel-shuffled version of the glossy material images. The location of the gloss-selective area was in agreement with previous macaque studies, showing activation in the ventral bank of STS. Our results suggest that perception of gloss is an important ability preserved across wide range of primate species. PMID:28367117

  17. A Novel Epi-drug Therapy Based on the Suppression of BET Family Epigenetic Readers

    Science.gov (United States)

    Shin, Dong-Guk; Bayarsaihan, Dashzeveg

    2017-01-01

    Recent progress in epigenetic research has made a profound influence on pharmacoepigenomics, one of the fastest growing disciplines promising to provide new epi-drugs for the treatment of a broad range of diseases. Histone acetylation is among the most essential chromatin modifications underlying the dynamics of transcriptional activation. The acetylated genomic regions recruit the BET (bromodomain and extra-terminal) family of bromodomains (BRDs), thereby serving as a molecular scaffold in establishing RNA polymerase II specificity. Over the past several years, the BET epigenetic readers have become the main targets for drug therapy. The discovery of selective small-molecule compounds with capacity to inhibit BET proteins has paved a path for developing novel strategies against cancer, cardiovascular, skeletal, and inflammatory diseases. Therefore, further research into small chemicals impeding the regulatory activity of BRDs could offer therapeutic benefits for many health problems including tumor growth, heart disease, oral, and bone disorders. PMID:28356894

  18. ANALYSIS OF SURFACE SINK OF EXPLORATION VACANCY IN GOLD MINING AREA OF ZHAOYUAN CTIY BASED ON RS AND GIS

    Institute of Scientific and Technical Information of China (English)

    WU Quan-yuan; AN Guo-qiang; BAO Wen-dong; ZHANG Zu-lu; XU Qiu-xiao; FANG Xue-mi

    2005-01-01

    Surface sink is a main geological calamity of gold mining areas and a main factor to restrict economic sustainable development of mining zone. Based on former investigations, this article draws the environment information of surface sink of exploration vacancy in gold mining area of Zhaoyuan City, Shangdong Province by RS technology. Through spatial simulation analysis and expert diagnoses on the basis of GIS technology, the article affirms the inducement factors of the surface sink. Then using these factors as distinguishing ones the authors prognosticate the criticality of other exploration vacancies. The results indicate that the surface sink area of study area in Zhaoyuan City, has already come to 0.78km2 and it is forecasted that 0.97km2 of the exploration vacancy belongs to high danger area. Decisive measures need taking in order to prevent this crucial problem. Another 1.57km2 of the exploration vacancies belongs to middle danger area, which will sink when meeting some inducing factors, such as earthquake. Still another 1.53kmn2 of the exploration vacancies belongs to low danger area that can not lead to surface sink when meeting common inducing factors.

  19. Description of surface systems. Preliminary site description. Forsmark area Version 1.2

    Energy Technology Data Exchange (ETDEWEB)

    Lindborg, Tobias (ed.)

    2005-06-01

    Swedish Nuclear Fuel and Waste Management Co (SKB) started site investigations for a deep repository for spent nuclear fuel in 2002 at two different sites in Sweden, Forsmark and Oskarshamn. The investigations should provide necessary information for a license application aimed at starting underground exploration. For this reason, ecosystem data need to be interpreted and assessed into site descriptive models, which in turn are used for safety assessment studies and for environmental impact assessment. Descriptions of the surface system are also needed for further planning of the site investigations. This report describes the surface ecosystems of the Forsmark site (e.g. hydrology, Quaternary deposits, chemistry, vegetation, animals and the human land use). The ecosystem description is an integration of the site and its regional setting, covering the current state of the biosphere as well as the ongoing natural processes affecting the longterm development. Improving the descriptions is important during both the initial and the complete site investigation phase. Before starting of the initial phase in Forsmark, version 0 of the site descriptive model was developed. The results of the initial site investigation phase is compiled into a preliminary site description of Forsmark (version 1.2) in June 2005. This report provides the major input and background to the biosphere description, in the 1.2 version of the Forsmark site description. The basis for this interim version is quality-assured field data from the Forsmark sub area and regional area, available in the SKB SICADA, and GIS data bases as of July 31th 2004 as well as version 1.1 of the Site Descriptive Model. To achieve an ecosystem site description there is a need to develop discipline-specific models by interpreting and analysing primary data. The different discipline-specific models are then integrated into a system describing interactions and flows and stocks of matter between and within functional units in

  20. Accessible reactive surface area and abiotic redox reactivity of iron oxyhydroxides in acidic brines

    Science.gov (United States)

    Strehlau, Jennifer H.; Toner, Brandy M.; Arnold, William A.; Penn, R. Lee

    2017-01-01

    The reactivity of iron oxyhydroxide nanoparticles in low pH and high ionic strength solutions was quantified to assess abiotic contributions to oxidation-reduction chemistry in acidic brine environments, such as mine groundwater seepage, lakes in Western Australia, and acid mine drainage settings, which are of global interest for their environmental impacts and unique geomicrobiology. Factors expected to influence accessible and reactive surface area, including Fe(II) adsorption and aggregate size, were measured as a function of pH and CaCl2 concentration and related to the kinetics of redox reactions in aqueous suspensions of synthetic goethite (α-FeOOH), akaganeite (β-FeOOH), and ferrihydrite (Fe10O14(OH)2) nanoparticles. Aqueous conditions and iron oxyhydroxides were chosen based on characterization of natural iron-rich mine microbial mats located in Soudan Underground Mine State Park, Minnesota, USA. Quinone species were used as redox sensors because they are well-defined probes and are present in natural organic matter. Fe(II) adsorption to the iron oxyhydroxide mineral surfaces from aqueous solution was measurable only at pH values above 4 and either decreased or was not affected by CaCl2 concentration. Concentrations at or above 0.020 M CaCl2 in acetate buffer (pH 4.5) induced particle aggregation. Assessment of Fe(II) adsorption and particle aggregation in acidic brine suggested that accessible reactive surface area may be limited in acidic brines. This was supported by observations of decreasing benzoquinone reduction rate by adsorbed Fe(II) at high CaCl2 concentration. In contrast, the hydroquinone oxidation rate increased at high CaCl2 concentrations, which may be due to suppressed adsorption of Fe(II) generated by the reaction. Results suggest that iron geochemical cycling in acidic brine environments will be substantially different than for iron oxyhydroxides in low-saline waters with circumneutral pH. These findings have implications for acidic

  1. Leg lesions and cleanliness of finishing bulls kept in housing systems with different lying area surfaces.

    Science.gov (United States)

    Schulze Westerath, H; Gygax, L; Mayer, C; Wechsler, B

    2007-07-01

    The influence of the quality of different lying surfaces on lesions and swellings at the joints as well as on the cleanliness of finishing bulls throughout the fattening period was studied. On 17 farms (623 bulls), pens with fully slatted concrete floors (CONCRETE), with rubber coated slats (RUBBER), with cubicles (CUBICLES, provided with five different types of soft lying mat) and with a littered lying area (STRAW) were compared. Bulls kept on STRAW developed the smallest lesion scores at the joints. In CUBICLES, there was a huge variability in the lesion scores depending on the type of lying mat, ranging from values comparable to STRAW up to and greater than the values for CONCRETE. The highest lesion scores at the carpal joints were found on CONCRETE, with intermediate values on RUBBER and in CUBICLES. At the tarsal joints, lesion scores were similar on CONCRETE and RUBBER and in the same range or worse on most mats in the CUBICLES. Swelling scores were highest on CONCRETE and intermediate on RUBBER and in CUBICLES compared to STRAW. In general, there was a steady increase in the lesion scores of the leg joints throughout the fattening period on CONCRETE, RUBBER and STRAW, whereas on some of the mats in CUBICLES these scores were at a high level from early on in the fattening period. Animals in all the housing systems were clean over the whole fattening period. Littering the lying area in CUBICLES affected neither the lesion scores nor the swelling scores at the joints nor animal cleanliness. In conclusion, both rubber coated slats and cubicles provided with soft lying mats were favourable with regard to the levels of lesions and swellings of the leg joints of finishing bulls compared to concrete slats. However, these levels were even lower in pens with a straw bedded lying area.

  2. 30 CFR 717.14 - Backfilling and grading of road cuts, mine entry area cuts, and other surface work areas.

    Science.gov (United States)

    2010-07-01

    ... to prevent leaching of toxic pollutants. Barren rock or similar materials excess to the mining... MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR INITIAL PROGRAM REGULATIONS UNDERGROUND MINING GENERAL PERFORMANCE STANDARDS § 717.14 Backfilling and grading of road cuts, mine entry area...

  3. In various protein complexes, disordered protomers have large per-residue surface areas and area of protein-, DNA- and RNA-binding interfaces.

    Science.gov (United States)

    Wu, Zhonghua; Hu, Gang; Yang, Jianyi; Peng, Zhenling; Uversky, Vladimir N; Kurgan, Lukasz

    2015-09-14

    We provide first large scale analysis of the peculiarities of surface areas of 5658 dissimilar (below 50% sequence similarity) proteins with known 3D-structures that bind to proteins, DNA or RNAs. We show here that area of the protein surface is highly correlated with the protein length. The size of the interface surface is only modestly correlated with the protein size, except for RNA-binding proteins where larger proteins are characterized by larger interfaces. Disordered proteins with disordered interfaces are characterized by significantly larger per-residue areas of their surfaces and interfaces when compared to the structured proteins. These result are applicable for proteins involved in interaction with DNA, RNA, and proteins and suggest that disordered proteins and binding regions are less compact and more likely to assume extended shape. We demonstrate that disordered protein binding residues in the interfaces of disordered proteins drive the increase in the per residue area of these interfaces. Our results can be used to predict in silico whether a given protomer from the DNA, RNA or protein complex is likely to be disordered in its unbound form.

  4. 33 CFR 334.1180 - Strait of Juan de Fuca, Wash.; air-to-surface weapon range, restricted area.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Strait of Juan de Fuca, Wash.; air-to-surface weapon range, restricted area. 334.1180 Section 334.1180 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.1180 Strait of Juan de...

  5. Betões eco-eficientes de matriz multi-funcional

    OpenAIRE

    Torgal,Fernando Pacheco; Jalali, Said

    2010-01-01

    Os betões eco-eficientes de matriz multi-funcional, congregam simultaneamente as características de sustentabilidade dos betões com incorporação de resíduos, as capacidades mecânicas dos compósitos de carbono, e ao mesmo tempo apresentam um comportamento “inteligente” actuando como materiais sensores. As funções “inteligentes” destes materiais incluem, controlo da integridade estrutural), monitorização da temperatura, interferência electromagnética, auto-aquecimento e protecção catódica no se...

  6. Vertical profiles of the specific surface area of the snow at Dome C, Antarctica

    Directory of Open Access Journals (Sweden)

    J.-C. Gallet

    2010-09-01

    Full Text Available The specific surface area (SSA of snow determines in Part the albedo of snow surfaces and the capacity of the snow to adsorb chemical species and catalyze reactions. Despite these crucial roles, almost no value of snow SSA are available for the largest permanent snow expanse on Earth, the Antarctic. We have measured the first vertical profiles of snow SSA near Dome C (DC: 75°06´ S, 123°20´ E, 3233 m a.s.l. on the Antarctic plateau, and at seven sites during the logistical traverse between Dome C and the French coastal base Dumont D'Urville (DDU: 66°40´ S, 140°01´ E during the Austral summer 2008–2009. We used the DUFISSS system, which measures the IR reflectance of snow at 1310 nm with an integrating sphere. At DC, the mean SSA of the snow in the top 1 cm is 38 m2 kg−1, decreasing monotonically to 14 m2 kg−1 at a depth of 15 cm. Along the traverse, the snow SSA profile is similar to that at DC in the first 600 km from DC. Closer to DDU, the SSA of the top 5 cm is 23 m2 kg−1, decreasing to 19 m2 kg−1 at 50 cm depth. This is attributed to wind, which causes a rapid decrease of surface snow SSA, but forms hard windpacks whose SSA decrease more slowly with time. Since light-absorbing impurities are not concentrated enough to affect albedo, the vertical profiles of SSA and density were used to calculate the spectral albedo of the snow for several realistic illumination conditions, using the DISORT radiative transfer model. A preliminary comparison with MODIS data is presented for use in energy balance calculations and for comparison with other satellite retrievals. These calculated albedos are compared to the few existing measurements on the Antarctic plateau. The interest of postulating a submillimetric, high-SSA layer at the snow surface to explain measured albedos is discussed.

  7. Retinotopic maps, spatial tuning, and locations of human visual areas in surface coordinates characterized with multifocal and blocked FMRI designs.

    Directory of Open Access Journals (Sweden)

    Linda Henriksson

    Full Text Available The localization of visual areas in the human cortex is typically based on mapping the retinotopic organization with functional magnetic resonance imaging (fMRI. The most common approach is to encode the response phase for a slowly moving visual stimulus and to present the result on an individual's reconstructed cortical surface. The main aims of this study were to develop complementary general linear model (GLM-based retinotopic mapping methods and to characterize the inter-individual variability of the visual area positions on the cortical surface. We studied 15 subjects with two methods: a 24-region multifocal checkerboard stimulus and a blocked presentation of object stimuli at different visual field locations. The retinotopic maps were based on weighted averaging of the GLM parameter estimates for the stimulus regions. In addition to localizing visual areas, both methods could be used to localize multiple retinotopic regions-of-interest. The two methods yielded consistent retinotopic maps in the visual areas V1, V2, V3, hV4, and V3AB. In the higher-level areas IPS0, VO1, LO1, LO2, TO1, and TO2, retinotopy could only be mapped with the blocked stimulus presentation. The gradual widening of spatial tuning and an increase in the responses to stimuli in the ipsilateral visual field along the hierarchy of visual areas likely reflected the increase in the average receptive field size. Finally, after registration to Freesurfer's surface-based atlas of the human cerebral cortex, we calculated the mean and variability of the visual area positions in the spherical surface-based coordinate system and generated probability maps of the visual areas on the average cortical surface. The inter-individual variability in the area locations decreased when the midpoints were calculated along the spherical cortical surface compared with volumetric coordinates. These results can facilitate both analysis of individual functional anatomy and comparisons of visual

  8. Responsiveness of the major birch allergen Bet v 1 scaffold to the gastric environment: Impact on structure and allergenic activity

    DEFF Research Database (Denmark)

    Sancho, Ana I; Wangorsch, Andrea; Jensen, Bettina M

    2011-01-01

    Four Bet v 1 homologous food allergens from celeriac (rApi g 1), apple (rMal d 1), peach (rPru p 1) and hazelnut (rCor a 1), were used to probe the structural responsiveness of the Bet v 1 scaffold to gastric digestion conditions and its impact on allergenicity.......Four Bet v 1 homologous food allergens from celeriac (rApi g 1), apple (rMal d 1), peach (rPru p 1) and hazelnut (rCor a 1), were used to probe the structural responsiveness of the Bet v 1 scaffold to gastric digestion conditions and its impact on allergenicity....

  9. High ethanol sensitivity of palladium/TiO2 nanobelt surface heterostructures dominated by enlarged surface area and nano-Schottky junctions.

    Science.gov (United States)

    Wang, Dongzhou; Zhou, Weijia; Hu, Peiguang; Guan, Yu; Chen, Limei; Li, Jianhua; Wang, Guancong; Liu, Hong; Wang, Jiyang; Cao, Guozhong; Jiang, Huaidong

    2012-12-15

    TiO(2) nanobelts were prepared by the hydrothermal growth method. The surface of the nanobelts was coarsened by selective acid corrosion and functionalized with Pd catalyst particles. Three nanobelt samples (TiO(2) nanobelts, surface-coarsened TiO(2) nanobelts and Pd nanoparticle/TiO(2) nanobelt surface heterostructures) were configured as gas sensors and their sensing ability was measured. Both the surface-coarsened nanobelts and the Pd nanoparticle-decorated TiO(2) nanobelts exhibited dramatically improved sensitivity to ethanol vapor. Pd nanoparticle-decorated TiO(2) nanobelts with surface heterostructures exhibited the best sensitivity, selectivity, working temperature, response/recovery time, and reproducibility. The excellent ethanol sensing performance is attributed to the large surface area and enhancement by Schottky barrier-type junctions between the Pd nanoparticles and TiO(2) nanobelts.

  10. Scaling properties of the radius of gyration and surface area for EF-hand calcium binding proteins

    Energy Technology Data Exchange (ETDEWEB)

    Pitulice, L. [West University of Timisoara, Department of Chemistry, Pestalozzi 16, 300115 Timisoara (Romania); Isvoran, A. [West University of Timisoara, Department of Chemistry, Pestalozzi 16, 300115 Timisoara (Romania)], E-mail: aisvoran@cbg.uvt.ro; Craescu, C.T. [INSERM U759/Institute Curie-Recherche, Centre Universitaire Paris-Sud, Batiment 112, 91405 Orsay (France); Chiriac, A. [West University of Timisoara, Department of Chemistry, Pestalozzi 16, 300115 Timisoara (Romania)

    2009-04-30

    In this paper, we analyze the scaling properties of both the radius of gyration and the surface area for EF-hand calcium binding proteins. These properties are different for two conformational subfamilies: proteins with extended and compact structures, respectively. The radius of gyration is a measure of the shape of protein, whereas its surface fractal dimension is a measure of its interatomic packing. Different scaling properties for the radius of gyration underline that these two subfamilies present different shapes whilst different scaling properties for the surface area reveal different strengths of their intermolecular forces. All these data suggest different mechanisms responsible for the global folding of proteins belonging to these two subfamilies.

  11. Assessment of Bet v 1-specific CD4+ T cell responses in allergic and nonallergic individuals using MHC class II peptide tetramers.

    Science.gov (United States)

    Van Overtvelt, Laurence; Wambre, Erik; Maillère, Bernard; von Hofe, Eric; Louise, Anne; Balazuc, Anne Marie; Bohle, Barbara; Ebo, Didier; Leboulaire, Christophe; Garcia, Gilles; Moingeon, Philippe

    2008-04-01

    In this study, we used HLA-DRB1*0101, DRB1*0401, and DRB1*1501 peptide tetramers combined with cytokine surface capture assays to characterize CD4(+) T cell responses against the immunodominant T cell epitope (peptide 141-155) from the major birch pollen allergen Bet v 1, in both healthy and allergic individuals. We could detect Bet v 1-specific T cells in the PBMC of 20 birch pollen allergic patients, but also in 9 of 9 healthy individuals tested. Analysis at a single-cell level revealed that allergen-specific CD4(+) T cells from healthy individuals secrete IFN-gamma and IL-10 in response to the allergen, whereas cells from allergic patients are bona fide Th2 cells (producing mostly IL-5, some IL-10, but no IFN-gamma), as corroborated by patterns of cytokines produced by T cell clones. A fraction of Bet v 1-specific cells isolated from healthy, but not allergic, individuals also expresses CTLA-4, glucocorticoid-induced TNF receptor, and Foxp 3, indicating that they represent regulatory T cells. In this model of seasonal exposure to allergen, we also demonstrate the tremendous dynamics of T cell responses in both allergic and nonallergic individuals during the peak pollen season, with an expansion of Bet v 1-specific precursors from 10(-6) to 10(-3) among circulating CD4(+) T lymphocytes. Allergy vaccines should be designed to recapitulate such naturally protective Th1/regulatory T cell responses observed in healthy individuals.

  12. Detecting changes in surface water area of Lake Kyoga sub-basin using remotely sensed imagery in a changing climate

    Science.gov (United States)

    Nsubuga, F. W. N.; Botai, Joel O.; Olwoch, Jane M.; Rautenbach, C. J. deW; Kalumba, Ahmed M.; Tsela, Philemon; Adeola, Abiodun M.; Sentongo, Ausi A.; Mearns, Kevin F.

    2017-01-01

    Detection of changes in Earth surface features, for example lakes, is important for understanding the relationships between human and natural phenomena in order to manage better the increasingly scarce natural resources. This work presents a procedure of using modified normalised difference water index (MNDWI) to detect fluctuations of lake surface water area and relate it to a changing climate. The study used radiometrically and geometrically rectified Landsat images for 1986, 1995 and 2010 encompassing the Kyoga Basin lakes of Uganda, in order to investigate the changes in surface water area between the respective years. The standard precipitation index (SPI) and drought severity index (DSI) are applied to show the relationship between variability of surface water area and climate parameters. The present analysis reveals that surface water area fluctuation is linked to rainfall variability. In particular, Lake Kyoga sub-basin lakes experienced an increase in surface water area in 2010 compared to 1986. This work has important implications to water resources management for Lake Kyoga and could be vital to water resource managers across Ugandan lakes.

  13. Creation of surface defects on carbon nanofibers by steam treatment

    Institute of Scientific and Technical Information of China (English)

    Zhengfeng; Shao; Min; Pang; Wei; Xia; Martin; Muhler; Changhai; Liang

    2013-01-01

    A direct strategy for the creation of defects on carbon nanofibers (CNFs) has been developed by steam treatment.Nitrogen physisorption,XRD,Raman spectra,SEM and TEM analyses proved the existence of the new defects on CNFs.BET surface area of CNFs after steam treatment was enhanced from 20 to 378 m2/g.Pd catalysts supported on CNFs were also prepared by colloidal deposition method.The different activity of Pd/CNFs catalysts in the partial hydrogenation of phenylacetylene further demonstrated the diverse surfaces of CNFs could be formed by steam treatment.

  14. Uranium(VI) adsorption and surface complexation modeling onto background sediments from the F-Area Savannah River Site.

    Science.gov (United States)

    Dong, Wenming; Tokunaga, Tetsu K; Davis, James A; Wan, Jiamin

    2012-02-07

    The mobility of an acidic uranium waste plume in the F-Area of Savannah River Site is of great concern. In order to understand and predict uranium mobility, U(VI) adsorption experiments were performed as a function of pH using background F-Area aquifer sediments and reference goethite and kaolinite (major reactive phases of F-Area sediments), and a component-additivity (CA) based surface complexation model (SCM) was developed. Our experimental results indicate that the fine fractions (≤45 μm) in sediments control U(VI) adsorption due to their large surface area, although the quartz sands show a stronger adsorption ability per unit surface area than the fine fractions at pH 4.0. Our CA model combines an existing U(VI) SCM for goethite and a modified U(VI) SCM for kaolinite along with estimated relative surface area abundances of these component minerals. The modeling approach successfully predicts U(VI) adsorption behavior by the background F-Area sediments. The model suggests that exchange sites on kaolinite dominate U(VI) adsorption at pH 6.0.

  15. Body surface area determined by whole-body CT scanning: need for new formulae?

    Science.gov (United States)

    Villa, Chiara; Primeau, Charlotte; Hesse, Ulrik; Hougen, Hans Petter; Lynnerup, Niels; Hesse, Birger

    2017-03-01

    Calculation of the estimated body surface area (BSA) by body height and weight has been a challenge in the past centuries due to lack of a well-documented gold standard. More recently, available techniques such as 3D laser surface scanning and CT scanning may be expected to quantify the BSA in an easier and more accurate way. This study provides the first comparison between BSA obtained from post-mortem whole-body CT scans and BSA calculated by nine predictive formulae. The sample consisted of 54 male cadavers ranging from 20 to 87 years old. 3D reconstructions were generated from CT scans using Mimics software, and BSA values were automatically extracted from the program. They were compared with nine predictive equations from the literature. Remarkably, close correlations (r > 0·90) were found between BSA values from CT scans and those from the predictive formulae. A mean BSA of the 54 cadavers of 1·84-1·87 m(2) was calculated by all formulae except one, SD values varying between 0·171 and 0·223 m(2) . T-tests revealed significant differences between mean BSA values calculated with CT and three of the formulae. Regression analyses showed intercepts >(0;0) and slopes <1·0 using all predictive equations, with the CT scan determination as gold standard. It is concluded that DuBois and DuBois' equation can be safely used in normal-weight male subjects with high accuracy, but it seems likely that BSA is underestimated in underweight subjects and overestimated in overweight individuals. Creation of new formulae specific for overweight subjects and children may be needed.

  16. Formula and scale for body surface area estimation in high-risk infants.

    Science.gov (United States)

    Ahn, Youngmee

    2010-12-01

    Advances in medical technology and the health sciences have lead to a rapid increase in the prevalence and morbidity of high-risk infants with chronic or permanent sequels such as the birth of early preterm infants. A suitable formula is therefore needed for body surface area (BSA) estimation for high-risk infants to more accurately devise therapeutic regimes in clinical practice. A cohort study involving 5014 high-risk infants was conducted to develop a suitable formula for estimating BSA using four of the existing formulas in the literature. BSA of high-risk infants was calculated using the four BSA equations (Boyd-BSA, Dubois-BSA, Meban-BSA, Mosteller-BSA), from which a new calculation, Mean-BSA, was arithmetically derived as a reference BSA measure. Multiple-regression was performed using nonlinear least squares curve fitting corresponding to the trend line and the new equation, Neo-BSA, developed using Excel and SPSS 17.0. The Neo-BSA equation was constructed as follows: Neo-BSA = 5.520 x W(0.5526) x L(0.300). With the assumption of the least square root relation between weight and length, a BSA scale using only weight was fabricated specifically for clinical applications where weight is more available in high-risk infant populations than is length. The validity of Neo-BSA was evaluated against Meban-BSA, the best of the four equations for high-risk infants, as there is a similarity of subjects in the two studies. The other formulas revealed substantial variances in BSA compared to Neo-BSA. This study developed a new surface area equation, Neo-BSA, as the most suitable formula for BSA measurement of high-risk infants in modern-day societies, where an emerging population of newborns with shorten gestational ages are becoming more prevalent as a result of new advances in the health sciences and new development of reproductive technologies. In particular, a scale for 400-7000 g body weight babies derived from the Neo-BSA equation has the clinical advantage of

  17. Closure Report for Corrective Action Unit 300: Surface Release Areas Nevada Test Site, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Environmental Restoration

    2007-07-01

    Corrective Action Unit (CAU) 300 is located in Areas 23, 25, and 26 of the Nevada Test Site, which is located approximately 65 miles northwest of Las Vegas, Nevada. CAU 300 is listed in the Federal Facility Agreement and Consent Order of 1996 as Surface Release Areas and is comprised of the following seven Corrective Action Sites (CASs), which are associated with the identified Building (Bldg): {sm_bullet} CAS 23-21-03, Bldg 750 Surface Discharge {sm_bullet} CAS 23-25-02, Bldg 750 Outfall {sm_bullet} CAS 23-25-03, Bldg 751 Outfall {sm_bullet} CAS 25-60-01, Bldg 3113A Outfall {sm_bullet} CAS 25-60-02, Bldg 3901 Outfall {sm_bullet} CAS 25-62-01, Bldg 3124 Contaminated Soil {sm_bullet} CAS 26-60-01, Bldg 2105 Outfall and Decon Pad The Nevada Division of Environmental Protection (NDEP)-approved corrective action alternative for CASs 23-21-03, 23-25-02, and 23-25-03 is no further action. As a best management practice, approximately 48 feet of metal piping was removed from CAS 23-25-02 and disposed of as sanitary waste. The NDEP-approved corrective action alternative for CASs 25-60-01, 25-60-02, 25-62-01, and 26-60-01, is clean closure. Closure activities for these CASs included removing and disposing of soil impacted with total petroleum hydrocarbons-diesel range organics (TPH-DRO), polychlorinated biphenyls (PCBs), semivolatile organic compounds (SVOCs), and cesium (Cs)-137, concrete impacted with TPH-DRO, and associated piping impacted with TPH-DRO. CAU 300 was closed in accordance with the NDEP-approved CAU 300 Corrective Action Plan (CAP) (U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office [NNSA/NSO], 2006). The closure activities specified in the CAP were based on the recommendations presented in the CAU 300 Corrective Action Decision Document (NNSA/NSO, 2005). This Closure Report documents CAU 300 closure activities. During closure activities, approximately 40 cubic yards (yd3) of low-level waste consisting of TPH-DRO-, PCB

  18. Design and stabilisation of a high area iron molybdate surface for the selective oxidation of methanol to formaldehyde.

    Science.gov (United States)

    Chapman, Stephanie; Brookes, Catherine; Bowker, Michael; Gibson, Emma K; Wells, Peter P

    2016-07-04

    The performance of Mo-enriched, bulk ferric molybdate, employed commercially for the industrially important reaction of the selective oxidation of methanol to formaldehyde, is limited by a low surface area, typically 5-8 m(2) g(-1). Recent advances in the understanding of the iron molybdate catalyst have focused on the study of MoOx@Fe2O3 (MoOx shell, Fe2O3 core) systems, where only a few overlayers of Mo are present on the surface. This method of preparing MoOx@Fe2O3 catalysts was shown to support an iron molybdate surface of higher surface area than the industrially-favoured bulk phase. In this research, a MoOx@Fe2O3 catalyst of even higher surface area was stabilised by modifying a haematite support containing 5 wt% Al dopant. The addition of Al was an important factor for stabilising the haematite surface area and resulted in an iron molybdate surface area of ∼35 m(2) g(-1), around a 5 fold increase on the bulk catalyst. XPS confirmed Mo surface-enrichment, whilst Mo XANES resolved an amorphous MoOx surface monolayer supported on a sublayer of Fe2(MoO4)3 that became increasingly extensive with initial Mo surface loading. The high surface area MoOx@Fe2O3 catalyst proved amenable to bulk characterisation techniques; contributions from Fe2(MoO4)3 were detectable by Raman, XAFS, ATR-IR and XRD spectroscopies. The temperature-programmed pulsed flow reaction of methanol showed that this novel, high surface area catalyst (3ML-HSA) outperformed the undoped analogue (3ML-ISA), and a peak yield of 94% formaldehyde was obtained at ∼40 °C below that for the bulk Fe2(MoO4)3 phase. This work demonstrates how core-shell, multi-component oxides offer new routes for improving catalytic performance and understanding catalytic activity.

  19. Scaling of Haversian canal surface area to secondary osteon bone volume in ribs and limb bones.

    Science.gov (United States)

    Skedros, John G; Knight, Alex N; Clark, Gunnar C; Crowder, Christian M; Dominguez, Victoria M; Qiu, Shijing; Mulhern, Dawn M; Donahue, Seth W; Busse, Björn; Hulsey, Brannon I; Zedda, Marco; Sorenson, Scott M

    2013-06-01

    Studies of secondary osteons in ribs have provided a great deal of what is known about remodeling dynamics. Compared with limb bones, ribs are metabolically more active and sensitive to hormonal changes, and receive frequent low-strain loading. Optimization for calcium exchange in rib osteons might be achieved without incurring a significant reduction in safety factor by disproportionally increasing central canal size with increased osteon size (positive allometry). By contrast, greater mechanical loads on limb bones might favor reducing deleterious consequences of intracortical porosity by decreasing osteon canal size with increased osteon size (negative allometry). Evidence of this metabolic/mechanical dichotomy between ribs and limb bones was sought by examining relationships between Haversian canal surface area (BS, osteon Haversian canal perimeter, HC.Pm) and bone volume (BV, osteonal wall area, B.Ar) in a broad size range of mature (quiescent) osteons from adult human limb bones and ribs (modern and medieval) and various adult and subadult non-human limb bones and ribs. Reduced major axis (RMA) and least-squares (LS) regressions of HC.Pm/B.Ar data show that rib and limb osteons cannot be distinguished by dimensional allometry of these parameters. Although four of the five rib groups showed positive allometry in terms of the RMA slopes, nearly 50% of the adult limb bone groups also showed positive allometry when negative allometry was expected. Consequently, our results fail to provide clear evidence that BS/BV scaling reflects a rib versus limb bone dichotomy whereby calcium exchange might be preferentially enhanced in rib osteons.

  20. Relationship between chemical shift value and accessible surface area for all amino acid atoms

    Directory of Open Access Journals (Sweden)

    Rieping Wolfgang

    2009-04-01

    Full Text Available Abstract Background Chemical shifts obtained from NMR experiments are an important tool in determining secondary, even tertiary, protein structure. The main repository for chemical shift data is the BioMagResBank, which provides NMR-STAR files with this type of information. However, it is not trivial to link this information to available coordinate data from the PDB for non-backbone atoms due to atom and chain naming differences, as well as sequence numbering changes. Results We here describe the analysis of a consistent set of chemical shift and coordinate data, in which we focus on the relationship between the per-atom solvent accessible surface area (ASA in the reported coordinates and their reported chemical shift value. The data is available online on http://www.ebi.ac.uk/pdbe/docs/NMR/shiftAnalysis/index.html. Conclusion Atoms with zero per-atom ASA have a significantly larger chemical shift dispersion and often have a different chemical shift distribution compared to those that are solvent accessible. With higher per-atom ASA, the chemical shift values also tend towards random coil values. The per-atom ASA, although not the determinant of the chemical shift, thus provides a way to directly correlate chemical shift information to the atomic coordinates.

  1. Real-time specific surface area measurements via laser-induced breakdown spectroscopy

    Science.gov (United States)

    Washburn, Kathryn E.; Birdwell, Justin E.; Howard, James E.

    2017-01-01

    From healthcare to cosmetics to environmental science, the specific surface area (SSA) of micro- and mesoporous materials or products can greatly affect their chemical and physical properties. SSA results are also widely used to examine source rocks in conventional and unconventional petroleum resource plays. Despite its importance, current methods to measure SSA are often cumbersome, time-consuming, or require cryogenic consumables (e.g., liquid nitrogen). These methods are not amenable to high-throughput environments, have stringent sample preparation requirements, and are not practical for use in the field. We present a new application of laser-induced breakdown spectroscopy for rapid measurement of SSA. This study evaluates geological samples, specifically organic-rich oil shales, but the approach is expected to be applicable to many other types of materials. The method uses optical emission spectroscopy to examine laser-generated plasma and quantify the amount of argon adsorbed to a sample during an inert gas purge. The technique can accommodate a wide range of sample sizes and geometries and has the potential for field use. These advantages for SSA measurement combined with the simultaneous acquisition of composition information make this a promising new approach for characterizing geologic samples and other materials.

  2. Retrieval of snow Specific Surface Area (SSA) from MODIS data in mountainous regions

    Science.gov (United States)

    Mary, A.; Dumont, M.; Dedieu, J.-P.; Durand, Y.; Sirguey, P.; Milhem, H.; Mestre, O.; Negi, H. S.; Kokhanovsky, A. A.

    2012-05-01

    This study describes a method to retrieve snow specific surface area (SSA) from satellite radiance reasurements in mountainous terrain. It aims at comparing different retrieval methods and at addressing topographic corrections of reflectance, namely slope and aspect of terrain and multiple reflections on neighbouring slopes. We use an iterative algorithm to compute reflectance from radiance of the MODerate resolution Imaging Spectrometer (MODIS) with a comprehensive correction of local illumination with regards to topography. The retrieved SSA is compared to the results of the snowpack model Crocus, fed by driving data from the SAFRAN meteorological analysis, over a large domain in the French Alps. We compared SSA retrievals with and without topographic or anisotropy correction, and with a spherical or non-spherical snow reflectance model. The topographic correction enables SSA to be retrieved in better agreement with those from SAFRAN-Crocus. The root mean square deviation is 10.0 m2 kg-1 and the bias is -0.6 m2 kg-1, over 3829 pixels representing seven different dates and snow conditions. The standard deviation of MODIS retrieved data, larger than the one of SAFRAN-Crocus estimates, is responsible for half this RMSD. It is due to the topographic classes used by SAFRAN-Crocus. In addition, MODIS retrieved data show SSA gradients with elevation and solar exposition, physically consistent and in good agreement with SAFRAN-Crocus.

  3. Retrieval of snow Specific Surface Area (SSA from MODIS data in mountainous regions

    Directory of Open Access Journals (Sweden)

    A. Mary

    2012-05-01

    Full Text Available This study describes a method to retrieve snow specific surface area (SSA from satellite radiance reasurements in mountainous terrain. It aims at comparing different retrieval methods and at addressing topographic corrections of reflectance, namely slope and aspect of terrain and multiple reflections on neighbouring slopes. We use an iterative algorithm to compute reflectance from radiance of the MODerate resolution Imaging Spectrometer (MODIS with a comprehensive correction of local illumination with regards to topography. The retrieved SSA is compared to the results of the snowpack model Crocus, fed by driving data from the SAFRAN meteorological analysis, over a large domain in the French Alps. We compared SSA retrievals with and without topographic or anisotropy correction, and with a spherical or non-spherical snow reflectance model. The topographic correction enables SSA to be retrieved in better agreement with those from SAFRAN-Crocus. The root mean square deviation is 10.0 m2 kg−1 and the bias is −0.6 m2 kg−1, over 3829 pixels representing seven different dates and snow conditions. The standard deviation of MODIS retrieved data, larger than the one of SAFRAN-Crocus estimates, is responsible for half this RMSD. It is due to the topographic classes used by SAFRAN-Crocus. In addition, MODIS retrieved data show SSA gradients with elevation and solar exposition, physically consistent and in good agreement with SAFRAN-Crocus.

  4. Accurate single-sequence prediction of solvent accessible surface area using local and global features.

    Science.gov (United States)

    Faraggi, Eshel; Zhou, Yaoqi; Kloczkowski, Andrzej

    2014-11-01

    We present a new approach for predicting the Accessible Surface Area (ASA) using a General Neural Network (GENN). The novelty of the new approach lies in not using residue mutation profiles generated by multiple sequence alignments as descriptive inputs. Instead we use solely sequential window information and global features such as single-residue and two-residue compositions of the chain. The resulting predictor is both highly more efficient than sequence alignment-based predictors and of comparable accuracy to them. Introduction of the global inputs significantly helps achieve this comparable accuracy. The predictor, termed ASAquick, is tested on predicting the ASA of globular proteins and found to perform similarly well for so-called easy and hard cases indicating generalizability and possible usability for de-novo protein structure prediction. The source code and a Linux executables for GENN and ASAquick are available from Research and Information Systems at http://mamiris.com, from the SPARKS Lab at http://sparks-lab.org, and from the Battelle Center for Mathematical Medicine at http://mathmed.org.

  5. Genetic network properties of the human cortex based on regional thickness and surface area measures

    Directory of Open Access Journals (Sweden)

    Anna R. Docherty

    2015-08-01

    Full Text Available We examined network properties of genetic covariance between average cortical thickness (CT and surface area (SA within genetically-identified cortical parcellations that we previously derived from human cortical genetic maps using vertex-wise fuzzy clustering analysis with high spatial resolution. There were 24 hierarchical parcellations based on vertex-wise CT and 24 based on vertex-wise SA expansion/contraction; in both cases the 12 parcellations per hemisphere were largely symmetrical. We utilized three techniques—biometrical genetic modeling, cluster analysis, and graph theory—to examine genetic relationships and network properties within and between the 48 parcellation measures. Biometrical modeling indicated significant shared genetic covariance between size of several of the genetic parcellations. Cluster analysis suggested small distinct groupings of genetic covariance; networks highlighted several significant negative and positive genetic correlations between bilateral parcellations. Graph theoretical analysis suggested that small world, but not rich club, network properties may characterize the genetic relationships between these regional size measures. These findings suggest that cortical genetic parcellations exhibit short characteristic path lengths across a broad network of connections. This property may be protective against network failure. In contrast, previous research with structural data has observed strong rich club properties with tightly interconnected hub networks. Future studies of these genetic networks might provide powerful phenotypes for genetic studies of normal and pathological brain development, aging, and function.

  6. The average body surface area of adult cancer patients in the UK: a multicentre retrospective study.

    Directory of Open Access Journals (Sweden)

    Joseph J Sacco

    Full Text Available The majority of chemotherapy drugs are dosed based on body surface area (BSA. No standard BSA values for patients being treated in the United Kingdom are available on which to base dose and cost calculations. We therefore retrospectively assessed the BSA of patients receiving chemotherapy treatment at three oncology centres in the UK between 1(st January 2005 and 31(st December 2005.A total of 3613 patients receiving chemotherapy for head and neck, ovarian, lung, upper GI/pancreas, breast or colorectal cancers were included. The overall mean BSA was 1.79 m(2 (95% CI 1.78-1.80 with a mean BSA for men of 1.91 m(2 (1.90-1.92 and 1.71 m(2 (1.70-1.72 for women. Results were consistent across the three centres. No significant differences were noted between treatment in the adjuvant or palliative setting in patients with breast or colorectal cancer. However, statistically significant, albeit small, differences were detected between some tumour groups.In view of the consistency of results between three geographically distinct UK cancer centres, we believe the results of this study may be generalised and used in future costings and budgeting for new chemotherapy agents in the UK.

  7. Preparation of activated carbon with high surface area for high-capacity methane storage

    Institute of Scientific and Technical Information of China (English)

    Bingsi Liua; Wenshuo Wanga; Na Wanga; Peter Chak Tong Aub

    2014-01-01

    Activated carbon (AC) was fabricated from corncob, which is cheap and abundant. Experimental parameters such as particle size of corncob, KOH/char weight ratio, and activation temperature and time were optimized to generate AC, which shows high methane sorption capacity. AC has high specific surface area (3227 m2/g), with pore volume and pore size distribution equal to 1.829 cm3/g and ca. 1.7-2.2 nm, respectively. Under the condition of 2◦C and less than 7.8 MPa, methane sorption in the presence of water (Rw=1.4) was as high as 43.7 wt%methane per unit mass of dry AC. The result is significantly higher than those of coconut-derived AC (32 wt%) and ordered mesoporous carbon (41.2 wt%, Rw=4.07) under the same condition. The physical properties and amorphous chaotic structure of AC were characterized by N2 adsorption isotherms, XRD, SEM and HRTEM. Hence, the corncob-derived AC can be considered as a competitive methane-storage material for vehicles, which are run by natural gas.

  8. Translating dosages from animal models to human clinical trials--revisiting body surface area scaling.

    Science.gov (United States)

    Blanchard, Otis L; Smoliga, James M

    2015-05-01

    Body surface area (BSA) scaling has been used for prescribing individualized dosages of various drugs and has also been recommended by the U.S. Food and Drug Administration as one method for using data from animal model species to establish safe starting dosages for first-in-human clinical trials. Although BSA conversion equations have been used in certain clinical applications for decades, recent recommendations to use BSA to derive interspecies equivalents for therapeutic dosages of drug and natural products are inappropriate. A thorough review of the literature reveals that BSA conversions are based on antiquated science and have little justification in current translational medicine compared to more advanced allometric and physiologically based pharmacokinetic modeling. Misunderstood and misinterpreted use of BSA conversions may have disastrous consequences, including underdosing leading to abandonment of potentially efficacious investigational drugs, and unexpected deadly adverse events. We aim to demonstrate that recent recommendations for BSA are not appropriate for animal-to-human dosage conversions and use pharmacokinetic data from resveratrol studies to demonstrate how confusion between the "human equivalent dose" and "pharmacologically active dose" can lead to inappropriate dose recommendations. To optimize drug development, future recommendations for interspecies scaling must be scientifically justified using physiologic, pharmacokinetic, and toxicology data rather than simple BSA conversion.

  9. Upgrade of three municipal wastewater treatment lagoons using a high surface area media

    Institute of Scientific and Technical Information of China (English)

    John WANC; Peng JINt; Paul L. BISHOP; Fuzhi LI

    2012-01-01

    Abstract Lagoon-based municipal wastewater treatment plants (WWTPs) are facing difficulties meeting the needs of rapid population growth as well as the more stringent requirements of discharge permits. Three municipal WWTPs were modified using a high surface area media with upgraded fine-bubble aeration systems. Performance data collected showed very promising results in terms of five-day biochemical oxygen demand (BOD5), ammonia (NH3) and total suspended solids (TSS) removal. Two-year average ammonia effluents were 4.1 mg. L-1 for Columbia WWTP, 4 mg. L-1 for Larchmont WWTP and 2.1 mg. L-1 for Laurelville WWTE respectively. Two- year average BOD5 effluents were 6.8, 4.9 and 2.7 mg.Ll, and TSS effluents were 15.0, 9.6 and 7.5 mg.L-L The systems also showed low fecal coliform (FC) levels in their effluents.

  10. Voice Morphing Using 3D Waveform Interpolation Surfaces and Lossless Tube Area Functions

    Directory of Open Access Journals (Sweden)

    Lavner Yizhar

    2005-01-01

    Full Text Available Voice morphing is the process of producing intermediate or hybrid voices between the utterances of two speakers. It can also be defined as the process of gradually transforming the voice of one speaker to that of another. The ability to change the speaker's individual characteristics and to produce high-quality voices can be used in many applications. Examples include multimedia and video entertainment, as well as enrichment of speech databases in text-to-speech systems. In this study we present a new technique which enables production of a given number of intermediate voices or of utterances which gradually change from one voice to another. This technique is based on two components: (1 creation of a 3D prototype waveform interpolation (PWI surface from the LPC residual signal, to produce an intermediate excitation signal; (2 a representation of the vocal tract by a lossless tube area function, and an interpolation of the parameters of the two speakers. The resulting synthesized signal sounds like a natural voice lying between the two original voices.

  11. Models to estimate the palm surface area of students in a tertiary institution in Abeokuta, Nigeria

    Directory of Open Access Journals (Sweden)

    S.O. Ismaila

    2016-12-01

    Full Text Available The need to use palm surface area (PSA in ergonomics, burn therapy, thermal physiology, and medicine necessitated the studies on its determination. The purpose of this study was to determine the PSA of students in a tertiary institution in Nigeria, propose a model to obtain the PSA, and use the neural network to reflect the effects of age, height, and weight on PSA. A total of 400 students comprising of 185 male and 215 female students aged between 16- and 25-years old were used for the study. Nonlinear regression analysis on SPSS 16.0 statistical package was used to extract the best fit correlation for Nigerian students with PSA as the dependent variable; and height, weight, and age as independent variables. The neural network on SPSS 16.0 was used to design the multilayer perceptron to predict PSA using age, height, and weight of the students. The estimated values using the models were not statistically different from the obtained values from the study (p = 0.000. The prediction of PSA showed that the neural network can be trained with almost no significant error of the output and that there was a nonlinear relationship between the input and output variables.

  12. Surface area and volume fraction of random open-pore systems

    Science.gov (United States)

    Hermann, H.; Elsner, A.; Stoyan, D.

    2013-12-01

    For the first time, explicit approximate formulas are presented for the volume fraction and specific surface area of random open-pore systems with poly-disperse pore size distributions. It is shown that the formulas are valid for broad classes of models for porous media characterized by tunable pore size distributions and a variable degree of inter-penetrability of pores. The formulas for the poly-disperse case are based on expressions derived previously for mono-disperse penetrable-sphere models. The results are obtained by analysis of a series of open-pore models, which are prepared by computer simulation of systems of randomly packed partially penetrable spheres with various poly-disperse size distributions such as gamma, lognormal, and Gaussian. The formulas are applied in a study of atomic layer deposition processes on open-pore systems, and the effective Young's modulus and the effective thermal conductivity of Al2O3 coated porous polypropylene electrodes for lithium ion batteries are predicted.

  13. Simulation Of Surface runoff For Upper Tapi Subcatchment Area (Burhanpur Watershed) Using SWAT

    Science.gov (United States)

    Shivhare, V.; Goel, M. K.; Singh, C. K.

    2014-11-01

    Water related activity that takes place in one part of a river basin may have consequence in the other part. Any plan related to inter basin transfer of water from a water surplus basin to a deficit basin has to take into account the water availability and demands under the present and future scenarios of water use. Watershed is a hydrologic unit where all stream exit from the common outlet. In the present study, Tapi subcatchment area (Burhanpur watershed) located in inter-state basin of Madhya Pradesh and Maharashtra, India, is selected for the estimation of surface runoff using SWAT model. The SWAT works in conjunction with Arc GIS 9.3. Various parameters Digital Elevation Model (DEM), slope derived from DEM, Landuse/Landcover (LULC) and NBSSLUP soil data and temporal data for temperature and precipitation was used as input for the model to predict runoff at the catchment outlet. The model was run from the year 1992 to 1997. The performance of the model in terms of simulated runoff was evaluated using statistical method and compared simulated monthly flow with the observed monthly flow values from 1992 to 1996 to a significant extent. The coefficient of determination (R2) for the monthly runoff values for 1992 to 1996 was observed to be 0.82, 0.68, 0.92, 0.69.

  14. Reliable nanomaterial classification of powders using the volume-specific surface area method

    Science.gov (United States)

    Wohlleben, Wendel; Mielke, Johannes; Bianchin, Alvise; Ghanem, Antoine; Freiberger, Harald; Rauscher, Hubert; Gemeinert, Marion; Hodoroaba, Vasile-Dan

    2017-02-01

    The volume-specific surface area (VSSA) of a particulate material is one of two apparently very different metrics recommended by the European Commission for a definition of "nanomaterial" for regulatory purposes: specifically, the VSSA metric may classify nanomaterials and non-nanomaterials differently than the median size in number metrics, depending on the chemical composition, size, polydispersity, shape, porosity, and aggregation of the particles in the powder. Here we evaluate the extent of agreement between classification by electron microscopy (EM) and classification by VSSA on a large set of diverse particulate substances that represent all the anticipated challenges except mixtures of different substances. EM and VSSA are determined in multiple labs to assess also the level of reproducibility. Based on the results obtained on highly characterized benchmark materials from the NanoDefine EU FP7 project, we derive a tiered screening strategy for the purpose of implementing the definition of nanomaterials. We finally apply the screening strategy to further industrial materials, which were classified correctly and left only borderline cases for EM. On platelet-shaped nanomaterials, VSSA is essential to prevent false-negative classification by EM. On porous materials, approaches involving extended adsorption isotherms prevent false positive classification by VSSA. We find no false negatives by VSSA, neither in Tier 1 nor in Tier 2, despite real-world industrial polydispersity and diverse composition, shape, and coatings. The VSSA screening strategy is recommended for inclusion in a technical guidance for the implementation of the definition.

  15. SURFACE AREA, VOLUME, MASS, AND DENSITY DISTRIBUTIONS FOR SIZED BOMASS PARTICLES

    Energy Technology Data Exchange (ETDEWEB)

    Ramanathan Sampath

    2004-05-01

    This semi-annual technical progress report describes work performed at Morehouse College under DOE Grant No. DE-FC26-04NT42130 during the period July 01, 2004 to December 31, 2004 which covers the first six months of the project. Presently work is in progress to characterize surface area, volume, mass, and density distributions for sized biomass particles. During this reporting period, supply requests were processed and supplies including biomass test particles (hardwood sawdust AI14546) in the size range of 100-200 microns were obtained from a cofiring pilot plant research facility owned by Southern Company, Birmingham, AL. Morehouse has completed setting up of the gravimetric technique measurement system in the heat transfer laboratory, department of physics and dual degree engineering, Morehouse College. Simultaneously, REM, our subcontractor, has completed setting up of the electrodynamic balance (EDB) measurement system to characterize shape and mass for individual biomass particles. Testing of the gravimetric system, and calibration of the cameras and imaging systems using known sizes of polystyrene particles are in progress.

  16. Genetic network properties of the human cortex based on regional thickness and surface area measures

    Science.gov (United States)

    Docherty, Anna R.; Sawyers, Chelsea K.; Panizzon, Matthew S.; Neale, Michael C.; Eyler, Lisa T.; Fennema-Notestine, Christine; Franz, Carol E.; Chen, Chi-Hua; McEvoy, Linda K.; Verhulst, Brad; Tsuang, Ming T.; Kremen, William S.

    2015-01-01

    We examined network properties of genetic covariance between average cortical thickness (CT) and surface area (SA) within genetically-identified cortical parcellations that we previously derived from human cortical genetic maps using vertex-wise fuzzy clustering analysis with high spatial resolution. There were 24 hierarchical parcellations based on vertex-wise CT and 24 based on vertex-wise SA expansion/contraction; in both cases the 12 parcellations per hemisphere were largely symmetrical. We utilized three techniques—biometrical genetic modeling, cluster analysis, and graph theory—to examine genetic relationships and network properties within and between the 48 parcellation measures. Biometrical modeling indicated significant shared genetic covariance between size of several of the genetic parcellations. Cluster analysis suggested small distinct groupings of genetic covariance; networks highlighted several significant negative and positive genetic correlations between bilateral parcellations. Graph theoretical analysis suggested that small world, but not rich club, network properties may characterize the genetic relationships between these regional size measures. These findings suggest that cortical genetic parcellations exhibit short characteristic path lengths across a broad network of connections. This property may be protective against network failure. In contrast, previous research with structural data has observed strong rich club properties with tightly interconnected hub networks. Future studies of these genetic networks might provide powerful phenotypes for genetic studies of normal and pathological brain development, aging, and function. PMID:26347632

  17. Measuring the specific surface area of wet snow using 1310 nm reflectance

    Directory of Open Access Journals (Sweden)

    J.-C. Gallet

    2013-10-01

    Full Text Available The specific surface area (SSA of snow can be used as an objective measurement of grain size and is therefore a central variable to describe snow physical properties such as albedo. Snow SSA can now be easily measured in the field using optical methods based on infrared reflectance. However, existing optical methods have only been validated for dry snow. Here we test the possibility to use the DUFISSS instrument, based on the measurement of the 1310 nm reflectance of snow with an integrating sphere, to measure the SSA of wet snow. We perform cold room experiments where we measure the SSA of a wet snow sample, freeze it and measure it again, to quantify the difference in reflectance between frozen and wet snow. We study snow samples in the SSA range 12–37 m2 kg−1 and in the mass liquid water content range 5–32%. We conclude that the SSA of wet snow can be obtained from the measurement of its 1310 nm reflectance using three simple steps. In most cases, the SSA thus obtained is less than 10% different from the value that would have been obtained if the sample had been considered dry, so that the three simple steps constitute a minor correction. We also run two optical models to interpret the results, but no model reproduces correctly the water-ice distribution in wet snow, so that their predictions of wet snow reflectance are imperfect.

  18. Near surface radial anisotropy in the Rigan area/SE Iran

    Science.gov (United States)

    Shirzad, Taghi; Shomali, Zaher-Hossein; Riahi, Mohammad-Ali; Jarrahi, Maziar

    2017-01-01

    By analyzing Rayleigh and Love wave empirical Green's functions extracted from ambient seismic noise and earthquake data, we obtained near surface radial anisotropy structure beneath the hidden part of the Kahurak fault in the Rigan region, in the southeast of Iran. The deduced seismic radial anisotropy within the hidden part of the Kahurak fault can reveal record of shallow crustal deformation caused by the Rigan earthquake (MW 6.5) occurred on 20 December 2010. Significant radial anisotropy with positive magnitude (VSH > VSV) appears in the shallow subsurface of the upper part of the crust. The magnitude of radial anisotropy varies from predominantly positive (VSH > VSV) to mostly negative (VSH VSV). The thickness of the sedimentary layer varies between 1 and 3 km from the south to the north beneath the study area with an average radial anisotropy of about 5%. However, cross-section profiles indicate that negative anomaly stretches inside a thick sedimentary layer where the aftershocks occurred. Also, the investigation of cross-section profiles reveals that a dipping angle of the hidden part of Kahurak fault is resolved at approximately 85° using the anisotropy pattern. Moreover, the aftershocks generally occurred in the transitional zones where signs of radial anisotropy anomalies change. Our study indicates that the influence of different resolving powers and path coverage density of Rayleigh and Love waves, which can be artificially interpreted as radial anisotropy, have minor effect on calculated radial anisotropy and they are estimated in the range of - 2% to + 2%.

  19. Marine organic geochemistry in industrially affected coastal areas in Greece: Hydrocarbons in surface sediments

    Science.gov (United States)

    Hatzianestis, Ioannis

    2015-04-01

    Hydrocarbons are abundant components of the organic material in coastal zones. Their sources are mainly anthropogenic, but several natural ones have also been recognized. Among hydrocarbons, the polycyclic aromatic ones (PAHs) have received special attention since they considered as hazardous environmental chemicals and are included in priority pollutant lists. The purpose of this study was to investigate the distribution, sources and transport pathways of hydrocarbons in marine areas in Greece directly influenced from the operation of major industrial units in the coastal zone by using a molecular marker approach, characteristic compositional patterns and related indices and also to evaluate their potential toxicity. Thirty two surface sediment samples were collected from three marine areas: a) Antikyra bay in Korinthiakos gulf, affected from the operation of an alumina and production plant b) Larymna bay in Noth Evoikos, affected from the operation of a nickel production plant and c) Aliveri bay in South Evoikos Gulf, affected from a cement production plant. In all the studied areas aquaculture and fishing activities have been also developed in the coastal zone. High aliphatic hydrocarbon (AHC) concentrations (~500 μg/g), indicating significant petroleum related inputs, were measured only in Antikyra bay. In all the other samples, AHC values were below 100 μg/g. N-alkanes were the most prominent resolved components (R) with an elevated odd to even carbon number preference, revealing the high importance of terrestrial inputs in the study areas. The unresolved complex mixture (UCM) was the major component of the aliphatic fraction (UCM/R > 4), indicating a chronic oil pollution. A series of hopanes were also identified, with patterns characteristic of oil-derived hydrocarbons, further confirming the presence of pollutant inputs from fossil fuel products. Extremely high PAH concentrations (> 100,000 ng/g) were found in the close vicinity of the alumina production

  20. Poker, Sports Betting, and Less Popular Alternatives: Status, Friendship Networks, and Male Adolescent Gambling

    Science.gov (United States)

    DiCicco-Bloom, Benjamin; Romer, Daniel

    2012-01-01

    The authors argue that the recent increase in poker play among adolescent males in the United States was primarily attributable to high-status male youth who are more able to organize "informal" gambling games (e.g., poker and sports betting) than are low-status male youth who are left to gamble on "formal" games (e.g., lotteries and slot…

  1. Individual contributions to portfolio risk: risk decomposition for the BET-FI index

    Directory of Open Access Journals (Sweden)

    Marius ACATRINEI

    2015-06-01

    Full Text Available The paper applies Euler formula for decomposing the standard deviation and the Expected Shortfall for the BET-FI equity index. Risk attribution allows the decomposition of the total risk of the portfolio in individual risk units. In this way we can compute the contribution of each company to the overall standard deviation/Expected Shortfall of the portfolio.

  2. Individual contributions to portfolio risk: risk decomposition for the BET-FI index

    OpenAIRE

    Marius ACATRINEI

    2015-01-01

    The paper applies Euler formula for decomposing the standard deviation and the Expected Shortfall for the BET-FI equity index. Risk attribution allows the decomposition of the total risk of the portfolio in individual risk units. In this way we can compute the contribution of each company to the overall standard deviation/Expected Shortfall of the portfolio.

  3. iBET: Immersive visualization of biological electron-transfer dynamics.

    Science.gov (United States)

    Nakano, C Masato; Moen, Erick; Byun, Hye Suk; Ma, Heng; Newman, Bradley; McDowell, Alexander; Wei, Tao; El-Naggar, Mohamed Y

    2016-04-01

    Recently, we presented a computational framework named VizBET to simulate and visualize biological electron-transfer (ET) dynamics. The visualization process was encapsulated as a plugin to the Visual Molecular Dynamics (VMD) software. However, the user's ability to understand complex, multidimensional ET pathways was severely limited when visualized in 2D on traditional computer monitors. To provide a more accurate representation with enhanced depth perception, we here present an extension of VizBET named iBET to render the VMD model of ET dynamics in a commodity virtual reality (VR) platform. The paper describes detailed procedures to export VMD models into the Unity game engine and render it in an Oculus Rift head mounted display. With the increasing availability of low-cost VR systems like the Rift and rich programmability of game engines, the iBET framework provides a powerful means to explore and understand not only biological ET processes but also a unique experiential tool for broad scientific communities.

  4. BET-VH: A Probabilistic Tool for Long- and Short-Term Volcanic Hazard Assessment

    Science.gov (United States)

    Marzocchi, W.; Selva, J.; Sandri, L.

    2005-12-01

    The purpose of this work is to present the probabilistic code BET-VH (Bayesian Event Tree for Volcanic Hazard) for long- and short-term volcanic hazard assessment. BET-VH follows the probabilistic scheme recently published by Marzocchi et al. (2004; Quantifying probabilities of volcanic events: the example of volcanic hazard at Mt. Vesuvius, J. Geophys. Res., vol. 109, B11201, doi:10.1029/2004JB003155), and it includes the fuzzy logic to minimize the effects of the choice of some particular thresholds of the model. In brief, BET-VH is based on a Bayesian approach applied to an Event Tree scheme that produces the probability estimation of any possible event in which we are interested, using all available information including theoretical models, historical and geological data, and monitoring observations. The general sequence is to estimate an a priori probability distribution based upon theoretical knowledge, to modify that using data. The procedure deals with epistemic and aleatory uncertainties in a formal way, through the estimation of probability distributions at each node of the Event Tree. In order to illustrate the potentiality of BET-VH in managing emergencies and in land use planning, we present applications of the code to some explosive volcanoes.

  5. Information Salience, Investor Sentiment, and Stock Returns : The Case of British Soccer Betting

    NARCIS (Netherlands)

    Palomino, F.A.; Renneboog, L.D.R.; Zhang, C.

    2008-01-01

    Soccer clubs listed on the London Stock Exchange provide a unique way of testing stock price reactions to different types of news. For each firm, two pieces of information are released on a weekly basis: experts’ expectations about game outcomes through the betting odds, and the game outcomes themse

  6. Information Salience, Investor Sentiment, and Stock Returns : The Case of British Soccer Betting

    NARCIS (Netherlands)

    Palomino, F.A.; Renneboog, L.D.R.; Zhang, C.

    2008-01-01

    Soccer clubs listed on the London Stock Exchange provide a unique way of testing stock price reactions to different types of news. For each firm, two pieces of information are released on a weekly basis: experts' expectations about game outcomes through the betting odds, and the game outcomes themse

  7. Highly polarized Th17 cells induce EAE via a T-bet independent mechanism.

    Science.gov (United States)

    Grifka-Walk, Heather M; Lalor, Stephen J; Segal, Benjamin M

    2013-11-01

    In the MOG35-55 induced EAE model, autoreactive Th17 cells that accumulate in the central nervous system acquire Th1 characteristics via a T-bet dependent mechanism. It remains to be determined whether Th17 plasticity and encephalitogenicity are causally related to each other. Here, we show that IL-23 polarized T-bet(-/-) Th17 cells are unimpaired in either activation or proliferation, and induce higher quantities of the chemokines RANTES and CXCL2 than WT Th17 cells. Unlike their WT counterparts, T-bet(-/-) Th17 cells retain an IL-17(hi) IFN-γ(neg-lo) cytokine profile following adoptive transfer into syngeneic hosts. This population of highly polarized Th17 effectors is capable of mediating EAE, albeit with a milder clinical course. It has previously been reported that the signature Th1 and Th17 effector cytokines, IFN-γ and IL-17, are dispensable for the development of autoimmune demyelinating disease. The current study demonstrates that the "master regulator" transcription factor, T-bet, is also not universally required for encephalitogenicity. Our results contribute to a growing body of data showing heterogeneity of myelin-reactive T cells and the independent mechanisms they employ to inflict damage to central nervous system tissues, complicating the search for therapeutic targets relevant across the spectrum of individuals with multiple sclerosis.

  8. Role of bundle helices in a regulatory crosstalk in the trimeric betaine transporter BetP.

    Science.gov (United States)

    Gärtner, Rebecca M; Perez, Camilo; Koshy, Caroline; Ziegler, Christine

    2011-12-02

    The Na(+)-coupled betaine symporter BetP regulates transport activity in response to hyperosmotic stress only in its trimeric state, suggesting a regulatory crosstalk between individual protomers. BetP shares the overall fold of two inverted structurally related five-transmembrane (TM) helix repeats with the sequence-unrelated Na(+)-coupled symporters LeuT, vSGLT, and Mhp1, which are neither trimeric nor regulated in transport activity. Conformational changes characteristic for this transporter fold involve the two first helices of each repeat, which form a four-TM-helix bundle. Here, we identify two ionic networks in BetP located on both sides of the membrane that might be responsible for BetP's unique regulatory behavior by restricting the conformational flexibility of the four-TM-helix bundle. The cytoplasmic ionic interaction network links both first helices of each repeat in one protomer to the osmosensing C-terminal domain of the adjacent protomer. Moreover, the periplasmic ionic interaction network conformationally locks the four-TM-helix bundle between the same neighbor protomers. By a combination of site-directed mutagenesis, cross-linking, and betaine uptake measurements, we demonstrate how conformational changes in individual bundle helices are transduced to the entire bundle by specific inter-helical interactions. We suggest that one purpose of bundle networking is to assist crosstalk between protomers during transport regulation by specifically modulating the transition from outward-facing to inward-facing state.

  9. Porogen effects in synthesis of uniform micrometer-sized poly(divinylbenzene) microspheres with high surface areas.

    Science.gov (United States)

    Hao, Dong-xia; Gong, Fang-ling; Wei, Wei; Hu, Guo-hua; Ma, Guang-hui; Su, Zhi-guo

    2008-07-01

    A new method of synthesizing uniform poly(divinylbenzene) (polyDVB) microspheres with high specific surface areas was designed by combining Shirasu porous glass (SPG) membrane emulsification, suspension polymerization, and post-crosslinking techniques. It was shown that the physicochemical properties of porogens have a great influence on the size distribution and porous features of microspheres. The low aqueous solubility of porogen facilitated preparation of uniform emulsions and microspheres, and high aqueous solubility led to polydispersed emulsions and poor microsphere yields. Such aqueous solubility effects can be tailored by adding a low molecular weight polystyrene (LPST) as costabilizer in porogen, thus improving the uniformity of microspheres. Moreover, different affinities of porogens for copolymers demonstrate various contributions to specific surface areas of microspheres in suspension polymerization especially post-crosslinking. Solvating porogen requires a much higher addition than nonsolvating porogen to obtain equal specific surface areas in polymerization, but has more potential to enhance the specific surface area in post-crosslinking. Two kinds of uniform microspheres were obtained with high specific surface areas, up to 706.6 m2/g by heptane and 937.5 m2/g by toluene.

  10. Effect of Activating Agent on the Preparation of Bamboo-Based High Surface Area Activated Carbon by Microwave Heating

    Science.gov (United States)

    Xia, Hongying; Wu, Jian; Srinivasakannan, Chandrasekar; Peng, Jinhui; Zhang, Libo

    2016-06-01

    The present work attempts to convert bamboo into a high surface area activated carbon via microwave heating. Different chemical activating agents such as KOH, NaOH, K2CO3 and Na2CO3 were utilized to identify a most suitable activating agent. Among the activating agents tested KOH was found to generate carbon with the highest porosity and surface area. The effect of KOH/C ratio on the porous nature of the activated carbon has been assessed. An optimal KOH/C ratio of 4 was identified, beyond which the surface area as well as the pore volume were found to decrease. At the optimized KOH/C ratio the surface area and the pore volume were estimated to be 3,441 m2/g and 2.093 ml/g, respectively, with the significant proportion of which being microporous (62.3%). Activated carbon prepared under the optimum conditions was further characterized using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). Activated carbons with so high surface area and pore volume are very rarely reported, which could be owed to the nature of the precursor and the optimal conditions of mixture ratio adopted in the present work.

  11. Characterization of the intragranular water regime within subsurface sediments: Pore volume, surface area, and mass transfer limitations

    Science.gov (United States)

    Hay, Michael B.; Stoliker, Deborah L.; Davis, James A.; Zachara, John M.

    2011-10-01

    Although "intragranular" pore space within grain aggregates, grain fractures, and mineral surface coatings may contain a relatively small fraction of the total porosity within a porous medium, it often contains a significant fraction of the reactive surface area, and can thus strongly affect the transport of sorbing solutes. In this work, we demonstrate a batch experiment procedure using tritiated water as a high-resolution diffusive tracer to characterize the intragranular pore space. The method was tested using uranium-contaminated sediments from the vadose and capillary fringe zones beneath the former 300A process ponds at the Hanford site (Washington). Sediments were contacted with tracers in artificial groundwater, followed by a replacement of bulk solution with tracer-free groundwater and the monitoring of tracer release. From these data, intragranular pore volumes were calculated and mass transfer rates were quantified using a multirate first-order mass transfer model. Tritium-hydrogen exchange on surface hydroxyls was accounted for by conducting additional tracer experiments on sediment that was vacuum dried after reaction. The complementary ("wet" and "dry") techniques allowed for the simultaneous determination of intragranular porosity and surface area using tritium. The Hanford 300A samples exhibited intragranular pore volumes of ˜1% of the solid volume and intragranular surface areas of ˜20%-35% of the total surface area. Analogous experiments using bromide ion as a tracer yielded very different results, suggesting very little penetration of bromide into the intragranular porosity.

  12. Characterization of the intragranular water regime within subsurface sediments: pore volume, surface area, and mass transfer limitations

    Science.gov (United States)

    Hay, Michael B.; Stoliker, Deborah L.; Davis, James A.; Zachara, John M.

    2011-01-01

    Although "intragranular" pore space within grain aggregates, grain fractures, and mineral surface coatings may contain a relatively small fraction of the total porosity within a porous medium, it often contains a significant fraction of the reactive surface area, and can thus strongly affect the transport of sorbing solutes. In this work, we demonstrate a batch experiment procedure using tritiated water as a high-resolution diffusive tracer to characterize the intragranular pore space. The method was tested using uranium-contaminated sediments from the vadose and capillary fringe zones beneath the former 300A process ponds at the Hanford site (Washington). Sediments were contacted with tracers in artificial groundwater, followed by a replacement of bulk solution with tracer-free groundwater and the monitoring of tracer release. From these data, intragranular pore volumes were calculated and mass transfer rates were quantified using a multirate first-order mass transfer model. Tritium-hydrogen exchange on surface hydroxyls was accounted for by conducting additional tracer experiments on sediment that was vacuum dried after reaction. The complementary ("wet" and "dry") techniques allowed for the simultaneous determination of intragranular porosity and surface area using tritium. The Hanford 300A samples exhibited intragranular pore volumes of ~1% of the solid volume and intragranular surface areas of ~20%–35% of the total surface area. Analogous experiments using bromide ion as a tracer yielded very different results, suggesting very little penetration of bromide into the intragranular porosity.

  13. Automated mapping of impervious surfaces in urban and suburban areas: Linear spectral unmixing of high spatial resolution imagery

    Science.gov (United States)

    Yang, Jian; He, Yuhong

    2017-02-01

    Quantifying impervious surfaces in urban and suburban areas is a key step toward a sustainable urban planning and management strategy. With the availability of fine-scale remote sensing imagery, automated mapping of impervious surfaces has attracted growing attention. However, the vast majority of existing studies have selected pixel-based and object-based methods for impervious surface mapping, with few adopting sub-pixel analysis of high spatial resolution imagery. This research makes use of a vegetation-bright impervious-dark impervious linear spectral mixture model to characterize urban and suburban surface components. A WorldView-3 image acquired on May 9th, 2015 is analyzed for its potential in automated unmixing of meaningful surface materials for two urban subsets and one suburban subset in Toronto, ON, Canada. Given the wide distribution of shadows in urban areas, the linear spectral unmixing is implemented in non-shadowed and shadowed areas separately for the two urban subsets. The results indicate that the accuracy of impervious surface mapping in suburban areas reaches up to 86.99%, much higher than the accuracies in urban areas (80.03% and 79.67%). Despite its merits in mapping accuracy and automation, the application of our proposed vegetation-bright impervious-dark impervious model to map impervious surfaces is limited due to the absence of soil component. To further extend the operational transferability of our proposed method, especially for the areas where plenty of bare soils exist during urbanization or reclamation, it is still of great necessity to mask out bare soils by automated classification prior to the implementation of linear spectral unmixing.

  14. Large-area homogeneous periodic surface structures generated on the surface of sputtered boron carbide thin films by femtosecond laser processing

    Energy Technology Data Exchange (ETDEWEB)

    Serra, R., E-mail: ricardo.serra@dem.uc.pt [SEG-CEMUC, Mechanical Engineering Department, University of Coimbra, Rua Luís Reis Santos, 3030-788 Coimbra (Portugal); Oliveira, V. [ICEMS-Instituto de Ciência e Engenharia de Materiais e Superfícies, Avenida Rovisco Pais no 1, 1049-001 Lisbon (Portugal); Instituto Superior de Engenharia de Lisboa, Avenida Conselheiro Emídio Navarro no 1, 1959-007 Lisbon (Portugal); Oliveira, J.C. [SEG-CEMUC, Mechanical Engineering Department, University of Coimbra, Rua Luís Reis Santos, 3030-788 Coimbra (Portugal); Kubart, T. [The Ångström Laboratory, Solid State Electronics, P.O. Box 534, SE-751 21 Uppsala (Sweden); Vilar, R. [Instituto Superior de Engenharia de Lisboa, Avenida Conselheiro Emídio Navarro no 1, 1959-007 Lisbon (Portugal); Instituto Superior Técnico, Avenida Rovisco Pais no 1, 1049-001 Lisbon (Portugal); Cavaleiro, A. [SEG-CEMUC, Mechanical Engineering Department, University of Coimbra, Rua Luís Reis Santos, 3030-788 Coimbra (Portugal)

    2015-03-15

    Highlights: • Large-area LIPSS were formed by femtosecond laser processing B-C films surface. • The LIPSS spatial period increases with laser fluence (140–200 nm). • Stress-related sinusoidal-like undulations were formed on the B-C films surface. • The undulations amplitude (down to a few nanometres) increases with laser fluence. • Laser radiation absorption increases with surface roughness. - Abstract: Amorphous and crystalline sputtered boron carbide thin films have a very high hardness even surpassing that of bulk crystalline boron carbide (≈41 GPa). However, magnetron sputtered B-C films have high friction coefficients (C.o.F) which limit their industrial application. Nanopatterning of materials surfaces has been proposed as a solution to decrease the C.o.F. The contact area of the nanopatterned surfaces is decreased due to the nanometre size of the asperities which results in a significant reduction of adhesion and friction. In the present work, the surface of amorphous and polycrystalline B-C thin films deposited by magnetron sputtering was nanopatterned using infrared femtosecond laser radiation. Successive parallel laser tracks 10 μm apart were overlapped in order to obtain a processed area of about 3 mm{sup 2}. Sinusoidal-like undulations with the same spatial period as the laser tracks were formed on the surface of the amorphous boron carbide films after laser processing. The undulations amplitude increases with increasing laser fluence. The formation of undulations with a 10 μm period was also observed on the surface of the crystalline boron carbide film processed with a pulse energy of 72 μJ. The amplitude of the undulations is about 10 times higher than in the amorphous films processed at the same pulse energy due to the higher roughness of the films and consequent increase in laser radiation absorption. LIPSS formation on the surface of the films was achieved for the three B-C films under study. However, LIPSS are formed under

  15. Human arachnoid granulations Part I: a technique for quantifying area and distribution on the superior surface of the cerebral cortex

    Directory of Open Access Journals (Sweden)

    Holman David W

    2007-07-01

    Full Text Available Abstract Background The arachnoid granulations (AGs are herniations of the arachnoid membrane into the dural venous sinuses on the surface of the brain. Previous morphological studies of AGs have been limited in scope and only one has mentioned surface area measurements. The purpose of this study was to investigate the topographic distribution of AGs on the superior surface of the cerebral cortex. Methods En face images were taken of the superior surface of 35 formalin-fixed human brains. AGs were manually identified using Adobe Photoshop, with a pixel location containing an AG defined as 'positive'. A set of 25 standard fiducial points was marked on each hemisphere for a total of 50 points on each image. The points were connected on each hemisphere to create a segmented image. A standard template was created for each hemisphere by calculating the average position of the 25 fiducial points from all brains. Each segmented image was mapped to the standard template using a linear transformation. A topographic distribution map was produced by calculating the proportion of AG positive images at each pixel in the standard template. The AG surface area was calculated for each hemisphere and for the total brain superior surface. To adjust for different brain sizes, the proportional involvement of AGs was calculated by dividing the AG area by the total area. Results The total brain average surface area of AGs was 78.53 ± 13.13 mm2 (n = 35 and average AG proportional involvement was 57.71 × 10-4 ± 7.65 × 10-4. Regression analysis confirmed the reproducibility of AG identification between independent researchers with r2 = 0.97. The surface AGs were localized in the parasagittal planes that coincide with the region of the lateral lacunae. Conclusion The data obtained on the spatial distribution and en face surface area of AGs will be used in an in vitro model of CSF outflow. With an increase in the number of samples, this analysis technique can be used

  16. Epigenetic intervention with a BET inhibitor ameliorates acute retinal ganglion cell death in mice

    Science.gov (United States)

    Li, Jun; Zhao, Lei; Urabe, Go; Fu, Yingmei

    2017-01-01

    Purpose The bromo and extraterminal (BET) epigenetic “reader” family is becoming an appealing new therapeutic target for several common diseases, yet little is known of its role in retinal neurodegeneration. We explored the potential of BET inhibition in the protection of retinal ganglion cells (RGCs). Methods To test the therapeutic effect of JQ1, an inhibitor highly selective for the BET family of proteins, we used an acute RGC damage model induced by N-methyl-D-aspartic acid (NMDA) excitotoxicity. Adult C57BL/6 mice received an intravitreal injection of NMDA with (or without) JQ1 in one eye and vehicle control in the contralateral eye; RGC loss was assessed on retinal sections and whole mounts. Gene expression and apoptosis were analyzed by quantitative real time (RT)-PCR and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), respectively. For counting RGCs, immunostaining of the marker protein BRN3A was performed on whole mounts. Results NMDA treatment eliminated RGCs (day 7 and day 14 post injection) and diminished the expression (mRNAs) of RGC-selective genes, including Thy1, Nrn1, Sncg, and Nfl (day 3 and day 7). In contrast, co-injection with JQ1 maintained the number and gene expression of RGCs at ~2 fold of the control (NMDA only, no JQ1), and it decreased NMDA-induced TUNEL-positive cells in the RGC layer by 35%. While NMDA treatment dramatically upregulated mRNAs of inflammatory cytokines (TNFα, IL-1β, MCP-1, RANTES) in retinal homogenates, co-injection with JQ1 suppressed their upregulation by ~50%. Conclusions Intravitreal injection of a BET inhibitor (JQ1) ameliorates NMDA-induced RGC death, revealing the RGC-protective potential of pharmacological blockage of the BET family. This new strategy of epigenetic intervention may be extended to other retinal degenerative conditions. PMID:28356707

  17. Surface Soil Preparetion for Leguminous Plants Growing in Degraded Areas by Mining Located in Amazon Forest-Brazil

    Science.gov (United States)

    Irio Ribeiro, Admilson; Hashimoto Fengler, Felipe; Araújo de Medeiros, Gerson; Márcia Longo, Regina; Frederici de Mello, Giovanna; José de Melo, Wanderley

    2015-04-01

    The revegetation of areas degraded by mining usually requires adequate mobilization of surface soil for the development of the species to be implemented. Unlike the traditional tillage, which has periodicity, the mobilization of degraded areas for revegetation can only occur at the beginning of the recovery stage. In this sense, the process of revegetation has as purpose the establishment of local native vegetation with least possible use of inputs and superficial tillage in order to catalyze the process of natural ecological succession, promoting the reintegration of areas and minimizing the negative impacts of mining activities in environmental. In this context, this work describes part of a study of land reclamation by tin exploitation in the Amazon ecosystem in the National Forest Jamari- Rondonia Brazil. So, studied the influence of surface soil mobilization in pit mine areas and tailings a view to the implementation of legumes. The results show that the surface has areas of mobilizing a significant effect on the growth of leguminous plants, areas for both mining and to tailings and pit mine areas.

  18. Hydrological Modelling and data assimilation of Satellite Snow Cover Area using a Land Surface Model, VIC

    Directory of Open Access Journals (Sweden)

    S. Naha

    2016-06-01

    Full Text Available The snow cover plays an important role in Himalayan region as it contributes a useful amount to the river discharge. So, besides estimating rainfall runoff, proper assessment of snowmelt runoff for efficient management and water resources planning is also required. A Land Surface Model, VIC (Variable Infiltration Capacity is used at a high resolution grid size of 1 km. Beas river basin up to Thalot in North West Himalayas (NWH have been selected as the study area. At first model setup is done and VIC has been run in its energy balance mode. The fluxes obtained from VIC has been routed to simulate the discharge for the time period of (2003-2006. Data Assimilation is done for the year 2006 and the techniques of Data Assimilation considered in this study are Direct Insertion (D.I and Ensemble Kalman Filter (EnKF that uses observations of snow covered area (SCA to update hydrologic model states. The meteorological forcings were taken from 0.5 deg. resolution VIC global forcing data from 1979-2006 with daily maximum temperature, minimum temperature from Climate Research unit (CRU, rainfall from daily variability of NCEP and wind speed from NCEP-NCAR analysis as main inputs and Indian Meteorological Department (IMD data of 0.25 °. NBSSLUP soil map and land use land cover map of ISRO-GBP project for year 2014 were used for generating the soil parameters and vegetation parameters respectively. The threshold temperature i.e. the minimum rain temperature is -0.5°C and maximum snow temperature is about +0.5°C at which VIC can generate snow fluxes. Hydrological simulations were done using both NCEP and IMD based meteorological Forcing datasets, but very few snow fluxes were obtained using IMD data met forcing, whereas NCEP based met forcing has given significantly better snow fluxes throughout the simulation years as the temperature resolution as given by IMD data is 0.5°C and rainfall resolution of 0.25°C. The simulated discharge has been validated

  19. Hydrological Modelling and data assimilation of Satellite Snow Cover Area using a Land Surface Model, VIC

    Science.gov (United States)

    Naha, Shaini; Thakur, Praveen K.; Aggarwal, S. P.

    2016-06-01

    The snow cover plays an important role in Himalayan region as it contributes a useful amount to the river discharge. So, besides estimating rainfall runoff, proper assessment of snowmelt runoff for efficient management and water resources planning is also required. A Land Surface Model, VIC (Variable Infiltration Capacity) is used at a high resolution grid size of 1 km. Beas river basin up to Thalot in North West Himalayas (NWH) have been selected as the study area. At first model setup is done and VIC has been run in its energy balance mode. The fluxes obtained from VIC has been routed to simulate the discharge for the time period of (2003-2006). Data Assimilation is done for the year 2006 and the techniques of Data Assimilation considered in this study are Direct Insertion (D.I) and Ensemble Kalman Filter (EnKF) that uses observations of snow covered area (SCA) to update hydrologic model states. The meteorological forcings were taken from 0.5 deg. resolution VIC global forcing data from 1979-2006 with daily maximum temperature, minimum temperature from Climate Research unit (CRU), rainfall from daily variability of NCEP and wind speed from NCEP-NCAR analysis as main inputs and Indian Meteorological Department (IMD) data of 0.25 °. NBSSLUP soil map and land use land cover map of ISRO-GBP project for year 2014 were used for generating the soil parameters and vegetation parameters respectively. The threshold temperature i.e. the minimum rain temperature is -0.5°C and maximum snow temperature is about +0.5°C at which VIC can generate snow fluxes. Hydrological simulations were done using both NCEP and IMD based meteorological Forcing datasets, but very few snow fluxes were obtained using IMD data met forcing, whereas NCEP based met forcing has given significantly better snow fluxes throughout the simulation years as the temperature resolution as given by IMD data is 0.5°C and rainfall resolution of 0.25°C. The simulated discharge has been validated using observed

  20. T-bet expression in the iris and spleen parallels disease expression during endotoxin-induced uveitis

    NARCIS (Netherlands)

    Li, B.; Yang, P.; Chu, L.; Zhou, H.; Huang, X.; Zhu, L.; Kijlstra, A.

    2007-01-01

    T lymphocytes have been implicated in the development of endotoxin-induced uveitis (EIU). T-bet is a Th1 cell-specific transcription factor that is involved in differentiation and effector functions. The aim of this study was to investigate kinetics of T-bet expression at the mRNA and protein levels