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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...... of antifouling coating behaviour because the active binder surface area and porosity of the leached layer are substantially increased. A similar effect was not observed for a coating with a mixture of ZnO and TiO2 pigments. The two experimental methods are expected to be useful for practical analysis of leaching...

  2. 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.

  3. 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. PMID:27082127

  4. 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

  5. Effect of BET surface area of recycled U3O8 powder on Mn-Al doped UO2 pellets property

    International Nuclear Information System (INIS)

    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 UO2 fuel pellets, defective UO2 pellets that do not meet the manufacturing specifications of density and diameter may be produced. Defective UO2 pellets or scraps of pellets should be reused in manufacturing new UO2 pellets. A commonly used recycling method for defective UO2 pellets or scraps of pellets is that defective UO2 pellets are oxidized in air at about 450 .deg. C to make U3O8 powder and then added to UO2 powder. Because the recycled U3O8 powder has a low sinter-ability compared to the raw UO2 powder, addition of U3O8 to UO2 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 U3O8 powder on UO2 pellet property becomes more severe in large grain sized UO2 pellets. In general, the sinter-active powder should have small size and large BET surface area. However, since the powder property of U3O8 depends on the initial grain size of UO2 pellets, larger grain UO2 pellet produces poorer sinter-active U3O8 powders having larger particle size and smaller BET surface area. In this paper, the effects of several process parameters on U3O8 powder properties have been tested. It is suggested that BET surface area of recycled U3O8 powder can be increased by applying low temperature oxidation and/or sequential cyclic thermal treatment procedures. The effect of those recycled U3O8 powder on the UO2 pellet properties is also investigated. The U3O8 powders having higher BET surface area can mitigate the UO2 pellet density drop

  6. BET measurements: Outgassing of minerals

    DEFF Research Database (Denmark)

    Clausen, Liselotte; Fabricius, Ida Lykke

    2000-01-01

    in minor errors, implying that aquifer sediments containing poorly crystalline materials can be outgassed at low temperatures if the outgassing time is increased. Scanning electron microscopy of the studied minerals demonstrated that the particle size as calculated from BET data compares well with......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...

  7. 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!

  8. 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

  9. 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.

  10. 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.

  11. 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

    allergen Malus domestica group 1 (Mal d 1). Engineering of the epitope was accomplished by genetic engineering substituting amino acid residues in Mal d 1 differing between Bet v 1 and Mal d 1 within the epitope defined by the mAb BV16. The kinetic parameters characterizing the antibody binding interaction......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...

  12. 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...

  13. Metal-organic framework materials with ultrahigh surface areas

    Science.gov (United States)

    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.

  14. 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.

  15. 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.

  16. 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...

  17. An example in surface area.

    Science.gov (United States)

    Goffman, C

    1969-05-01

    For length and area, a central fact is that the value of the length of a curve or the area of a surface, as given by the Lebesgue theory, is at least as great as that given by the classical formula, whenever the latter has meaning. This is now found not to be valid in higher dimensions. We give an example of a continuous mapping of the unit cube into itself for which the value given by the formula exceeds the three-dimensional Lebesgue area of the corresponding suface.

  18. 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.

  19. 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.

  20. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Aaron; Serov, Alexey; Artyushkova, Kateryna [Department of Chemical and Biological Engineering and Center for Micro-Engineered Materials, University of New Mexico, NM 87131 (United States); Brosha, Eric L. [Sensors and Electrochemical Devices (MPA-11), Los Alamos National Laboratory, NM 87545 (United States); Atanassov, Plamen, E-mail: tlward@unm.edu [Department of Chemical and Biological Engineering and Center for Micro-Engineered Materials, University of New Mexico, NM 87131 (United States); Ward, Tim L., E-mail: plamen@unm.edu [Department of Chemical and Biological Engineering and Center for Micro-Engineered Materials, University of New Mexico, NM 87131 (United States)

    2015-08-15

    The synthesis of high surface area γ-Mo{sub 2}N and α-Mo{sub 2}C is reported (116 and 120 m{sup 2}/g) without the temperature programmed reduction of MoO{sub 3}. γ-Mo{sub 2}N was prepared in an NH{sub 3}-free synthesis using forming gas (7 at% H{sub 2}, N{sub 2}-balance) as the reactive atmosphere. Three precursors were studied ((NH{sub 4}){sub 6}Mo{sub 7}O{sub 24}·4H{sub 2}O, (NH{sub 4}){sub 2} Mg(MoO{sub 4}){sub 2}, and MgMoO{sub 4}) along with the sacrificial support method (SSM) as a means of reducing the particle size of Mo{sub 2}N and Mo{sub 2}C. 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 Mo{sub 2}N products. Materials were synthesized in bulk and further characterized by XRD, HRTEM, XPS, and BET. - Highlights: • Facile synthesis of γ-Mo2N and α-Mo2C with surface area exceeding 100 m{sup 2}/g. • Sacrificial support method was used to achieve these high surface areas. • Materials can serve as catalysts or supports in (electro)chemical processes.

  2. The Change in Surface Area Properties of Blast Furnace

    Directory of Open Access Journals (Sweden)

    Rađenović, A.

    2009-04-01

    Full Text Available Blast furnace sludge-BFS is a by-product and waste material of the iron and steel industry. Recently, the adsorption capabilities of blast furnace sludge have been attracting great interest. It is known that materials with modified surface properties can be obtained by different chemical and thermal treatments.The aim of this work was to investigate the influence of chemical treatment by acetic acid and thermal treatment by heating at 700 °C, on the surface properties of blast furnace sludge. Chemical treatment was performed by acetic acid adsorption on BFS.Microscopic observation was conducted using scanning electron microscopy (SEM method. Changes in examined surface area properties were analyzed by Brunauer-Emmett-Teller (BET and Barrett-Joyner-Halenda (BJH methods.Increasing of specific surface area, decreasing of pore size and better pore size distribution in BFS samples were registered after the applied experimental procedure. The obtained results revealed that the performed chemical and heat treatment presented the activation of blast furnace sludge.

  3. 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.

  4. 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.

  5. 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.

  6. BET is active on Sellafield site

    International Nuclear Information System (INIS)

    Several companies, all part of BET Plant Services are carrying out work at the British Nuclear Fuels (BNFL) site at Sellafield, Cumbria, on one of the largest construction projects in Europe. The main development scheme is the THORP (Thermal Oxide Reprocessing Plant) buildings. One of the BET companies has the contract to paint the inside of the fuel storage ponds. It will also coat the surfaces of the MASWEP (Medium Active Solid Waste Encapsulation Plant) complex. Other work includes insulation and fire prevention installation. Scaffolding at the EARP (Enhanced Actinide Removal Plant) site is being provided on a common user basis so all the contractors can use the scaffolding and share the cost. Temporary office and living accommodation blocks have been provide by another BET company. (author)

  7. 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

  8. 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.

  9. 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. PMID:26726991

  10. Determination of oxide film thickness on aluminium using 14-MeV neutron activation and BET method

    International Nuclear Information System (INIS)

    A new method is described for the determination of the mean film thickness of aluminium oxides by 14-MeV neutron activation analysis of the oxygen and by BET measurement of the surface area. The mean film thickness obtained is independent of the surface roughness. Stable oxide films consisting of only a few atomic layers of oxygen are detected on aluminium. (author)

  11. 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.......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...... of the BAB factor is low; (4) Increased funding liquidity risk compresses betas toward one; (5) More constrained investors hold riskier assets....

  12. 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 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......, the return of the BAB factor is low. (4) Increased funding liquidity risk compresses betas toward one. (5) More constrained investors hold riskier assets....

  13. 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...

  14. 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.

  15. 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.

  16. The Importance of Betting Early

    OpenAIRE

    Alessandro Innocenti; Tommaso Nannicini; Roberto Ricciuti

    2012-01-01

    We analyze more than 1,250,000 bets on Italian soccer league matches. Our findings show that bettors do not improve their performance as the season progresses. We obtain evidence that early bettors, who place bets the days before the match, performed better then late bettors, who place bets on the same day of the event. We attribute this outcome to the increase of noisy information released the last day impairing late bettors’ capacity to use very simple prediction methods, such as team ranki...

  17. 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.

  18. 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.

  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. 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.

  2. Low-Risk Investing without Industry Bets

    DEFF Research Database (Denmark)

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

    2014-01-01

    of industry bets that favor a slowly changing set of stodgy, stable industries. The authors refute this notion by showing that a strategy of betting against beta has delivered positive returns both as an industry-neutral bet within each industry and as a pure bet across industries....

  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. Corporate Social Responsibility in the Gambling and Betting Activities Industry

    OpenAIRE

    Ševčíková, Terézia

    2016-01-01

    The bachelor thesis is focused on Corporate Social Responsibility in the Gambling and Betting Activities Industry in the Czech Republic. Based on the quantitative research in gambling and betting enterprises in the Czech Republic an analysis was performed and current CSR situation was evaluated. Analysis revealed that the selected sector supports relatively actively CSR activities in all three areas. Furthermore, considerable number of enterprises engages the corporate social responsibility i...

  5. 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...

  6. Determining surface areas of marine alga cells by acid-base titration method.

    Science.gov (United States)

    Wang, X; Ma, Y; Su, Y

    1997-09-01

    A new method for determining the surface area of living marine alga cells was described. The method uses acid-base titration to measure the surface acid/base amount on the surface of alga cells and uses the BET (Brunauer, Emmett, and Teller) equation to estimate the maximum surface acid/base amount, assuming that hydrous cell walls have carbohydrates or other structural compounds which can behave like surface Brönsted acid-base sites due to coordination of environmental H2O molecules. The method was applied to 18 diverse alga species (including 7 diatoms, 2 flagellates, 8 green algae and 1 red alga) maintained in seawater cultures. For the species examined, the surface areas of individual cells ranged from 2.8 x 10(-8) m2 for Nannochloropsis oculata to 690 x 10(-8) m2 for Dunaliella viridis, specific surface areas from 1,030 m2.g-1 for Dunaliella salina to 28,900 m2.g-1 for Pyramidomonas sp. Measurement accuracy was 15.2%. Preliminary studies show that the method may be more promising and accurate than light/electron microscopic measurements for coarse estimation of the surface area of living algae. PMID:9297794

  7. Characterization and use of high surface area activated carbons prepared from cane pith for liquid-phase adsorption

    International Nuclear Information System (INIS)

    Carbonaceous adsorbents with controllable surface areas were chemically activated with KOH at 780 deg. C from char that had been carbonized from cane pith at 450 deg. C. The pore properties including the BET surface area, pore volume, pore size distribution, and mean pore diameter of these activated carbons were characterized and derived using the t-plot method based on N2 adsorption isotherms. The activated cane pith carbons, with KOH/char ratios of 2-6, exhibited BET surface areas ranging from 912 to 2299 m2 g-1. The scanning electron microscopic (SEM) observations revealed that the surface morphology of honeycombed holes on all activated cane pith carbons was significantly influenced by the KOH/char ratio. The adsorption kinetics and equilibrium isotherms of acid blue 74, methylene blue, basic brown 1, p-nitrophenol, p-chlorophenol, p-cresol, and phenol from water at 30 deg. C on the activated carbons were studied. The adsorption kinetics were suitably described by a simplified kinetic model, the Elovich equation. All adsorption equilibrium isotherms were in agreement with the Langmuir equation, and were used to compare the covered area (S c/S p) of the activated carbons at different KOH/char ratios. The high-surface-area activated carbons were proven to be promising adsorbents for pollution control and for other applications

  8. Adsorbed Natural Gas Storage in Optimized High Surface Area Microporous Carbon

    Science.gov (United States)

    Romanos, Jimmy; Rash, Tyler; Nordwald, Erik; Shocklee, Joshua Shawn; Wexler, Carlos; Pfeifer, Peter

    2011-03-01

    Adsorbed natural gas (ANG) is an attractive alternative technology to compressed natural gas (CNG) or liquefied natural gas (LNG) for the efficient storage of natural gas, in particular for vehicular applications. In adsorbants engineered to have pores of a few molecular diameters, a strong van der Walls force allows reversible physisorption of methane at low pressures and room temperature. Activated carbons were optimized for storage by varying KOH:C ratio and activation temperature. We also consider the effect of mechanical compression of powders to further enhance the volumetric storage capacity. We will present standard porous material characterization (BET surface area and pore-size distribution from subcritical N2 adsorption) and methane isotherms up to 250 bar at 293K. At sufficiently high pressure, specific surface area, methane binding energy and film density can be extracted from supercritical methane adsorption isotherms. Research supported by the California Energy Commission (500-08-022).

  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. Betting on wind energy

    International Nuclear Information System (INIS)

    In the first part of this study, the authors try to identify whether the economical and environmental context is adapted to the wind energy development. In order to do so, they discuss wind energy as a possible answer to climate emergency, critics formulated against wind energy, the effects of the financial crisis and the opportunities offered by wind energy within this crisis. In the second part, they discuss the French context and the debates on wind energy, highlighting the importance of some parameters in the cost analysis of wind turbine, presenting the results of a sensitivity analysis, and highlighting the importance of the over-cost calculation. They assess the current development status of the French wind energy industry and underline the opportunities for the future. In the third part, they describe the development status, lever and perspectives in different countries: Germany where the development of this sector has been successful, China which is becoming a major actor, the United States which are displaying the highest growth in this area, and Denmark which is the world leader

  11. 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.

  12. Chemical weathering rates of a soil chronosequence on granitic alluvium: I. Quantification of mineralogical and surface area changes and calculation of primary silicate reaction rates

    Science.gov (United States)

    White, A.F.; Blum, A.E.; Schulz, M.S.; Bullen, T.D.; Harden, J.W.; Peterson, M.L.

    1996-01-01

    Mineral weathering rates are determined for a series of soils ranging in age from 0.2-3000 Ky developed on alluvial terraces near Merced in the Central Valley of California. Mineralogical and elemental abundances exhibit time-dependent trends documenting the chemical evolution of granitic sand to residual kaolinite and quartz. Mineral losses with time occur in the order: hornblende > plagioclase > K-feldspar. Maximum volume decreases of >50% occur in the older soils. BET surface areas of the bulk soils increase with age, as do specific surface areas of aluminosilicate mineral fractions such as plagioclase, which increases from 0.4-1.5 m2 g-1 over 600 Ky. Quartz surface areas are lower and change less with time (0.11-0.23 m2 g-1). BET surface areas correspond to increasing external surface roughness (?? = 10-600) and relatively constant internal surface area (??? 1.3 m2 g-1). SEM observations confirm both surface pitting and development of internal porosity. A numerical model describes aluminosilicate dissolution rates as a function of changes in residual mineral abundance, grain size distributions, and mineral surface areas with time. A simple geometric treatment, assuming spherical grains and no surface roughness, predicts average dissolution rates (plagioclase, 10-17.4; K-feldspar, 10-17.8; and hornblende, 10-17.5 mol cm-1 s-1) that are constant with time and comparable to previous estimates of soil weathering. Average rates, based on BET surface area measurements and variable surface roughnesses, are much slower (plagioclase, 10-19.9; K-feldspar, 10-20.5; and hornblende 10-20.1 mol cm-2 s-1). Rates for individual soil horizons decrease by a factor of 101.5 over 3000 Ky indicating that the surface reactivities of minerals decrease as the physical surface areas increase. Rate constants based on BET estimates for the Merced soils are factors of 103-104 slower than reported experimental dissolution rates determined from freshly prepared silicates with low surface

  13. Surface area estimation: pocket calculator v nomogram.

    OpenAIRE

    Briars, G L; Bailey, B J

    1994-01-01

    Three sheets of 10 surface area determinations were completed by 10 subjects using a nomogram and a formula. The formula was faster to calculate, 4.27 v 7.6 minutes for each sheet, and resulted in fewer serious errors (three v 30 errors).

  14. Synthesis of high surface area ZnO powder by continuous precipitation

    International Nuclear Information System (INIS)

    Graphical abstract: High surface area ZnO powders are synthesized by a low temperature continuous precipitation under ultrasonication. Urea is used as precipitating agent so that no contamination of ZnO powder emanating from precipitating agent, such as, alkalis, is observed. pH and type of precursor greatly affects the surface area and other properties. In this manuscript, we report a very simple and effective continuous precipitation to synthesize high surface area ZnO powder. Highlights: ► The synthesis of high surface area ZnO powder was achieved at 90 °C in a continuous precipitation unit. ► Continuous precipitation unit was ultrasonicated to improve final product homogeneity. ► Precipitation intermediate, hydrozincite, was led to high surface area ZnO powder. ► The synthesized ZnO nanoparticles had a rather uniform mesoporous structure. -- Abstract: Synthesis of high surface area ZnO powder was achieved by continuous precipitation using zinc ions and urea at low temperature of 90 °C. The powder precipitated resulted in high-purity single-phase ZnO powder when calcined at 280 °C for 3 h in air. The solution pH and the precipitation duration strongly affected the surface area of the calcined ZnO powder. Detailed structural characterizations demonstrated that the synthesized ZnO powder were single crystalline with wurtzite hexagonal phase. The powdered samples precipitated by homogeneous precipitation crystallized directly to hydrozincite without any intermediate phase formation. The phase structures, morphologies and properties of the final ZnO powders were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), dynamic light scattering particle size analysis (DLS), and nitrogen physisorption in order to determine the specific surface area (BET) and the pore size distribution (BJH).

  15. On semiautomatic estimation of surface area

    DEFF Research Database (Denmark)

    Dvorak, J.; Jensen, Eva B. Vedel

    2013-01-01

    In this paper, we propose a semiautomatic procedure for estimation of particle surface area. It uses automatic segmentation of the boundaries of the particle sections and applies different estimators depending on whether the segmentation was judged by a supervising expert to be satisfactory....... If the segmentation is correct the estimate is computed automatically, otherwise the expert performs the necessary measurements manually. In case of convex particles we suggest to base the semiautomatic estimation on the so-called flower estimator, a new local stereological estimator of particle surface area....... 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...

  16. Have betting exchanges corrupted horse racing?

    OpenAIRE

    Brown, Alasdair; Yang, Fuyu

    2016-01-01

    Betting exchanges allow punters to bet on a horse to lose a race. This, many argue, has opened up the sport to a new form of corruption, where races will be deliberately lost in order to profit from betting. We examine whether anecdotal evidence of the fixing of horses to lose - of which there are many examples - is indicative of wider corruption. Following a ‘forensic economics’ approach, we build an asymmetric information model of exchange betting, and take it to betting data on 9,560 races...

  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. The effect of specific surface area on radionuclide sorption on crushed crystalline rock

    Energy Technology Data Exchange (ETDEWEB)

    Hoelttae, P.; Siitari-Kauppi, M.; Huikuri, P. [Univ. of Helsinki (Finland). Dept. of Chemistry; Lindberg, A. [Geological Survey of Finland, Espoo (Finland); Hautojaervi, A. [VTT Energy (Finland)

    1997-12-31

    The sorption of sodium ({sup 22}Na), calcium ({sup 45}Ca) and strontium ({sup 85}Sr) was studied on mica gneiss, unaltered, moderately altered and strongly altered tonalite samples taken from hole SY-KR7 drilled in the Syyry area in Sievi, Western Finland. The crushed rock samples were sieved into six fractions from 71 {micro}m to 1,250 {micro}m. A proportional mineral composition for the different fractions were estimated by X-ray diffraction. The specific fraction surface areas were determined by the BET nitrogen adsorption method. The fractal method was applied to characterize rocks and to describe quantitatively surface irregularity. The mass distribution ratio values for each fraction were determined using the static batch method. The sorption of tracers onto different minerals was observed using rock thin sections. K{sub d}-values calculated from thin section K{sub a}-values and K{sub d}-values obtained from batch experiments were in good agreement. Mass distribution ratios for different size fractions are given, and the effect of the specific surface area is discussed. Owing to larger specific surface areas considerably higher sorption on smaller fractions was found for altered tonalities.

  19. 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%.

  20. 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.

  1. Dependence of the specific surface area of the nuclear fuel with the matrix oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, F.; Quinones, J.; Iglesias, E.; Rodriguez, N. [CIEMAT. Avda. Complutense 22, 28040-Madrid (Spain)

    2008-07-01

    This paper is focused on the study of the changes in the specific surface area measured using BET techniques. The objective is to obtain a relation between this parameter and the change in the matrix stoichiometry (i.e., oxidation increase). None of the actual models used for extrapolating the behaviour of the spent fuel matrix under repository conditions have included this dependence yet. In this work the specific surface area of different uranium oxide were measured using N{sub 2}(g) and Kr(g). The starting material was UO{sub 2+x}(s) with a size powder distribution lower than 20 {mu}m. The results included in this paper shown a strong dependence on specific surface area with the matrix stoichiometry, i.e., and increase of more than one order of magnitude (SUO{sub 2} = 6 m{sup 2}*g{sup -1} and SU{sub 3}O{sub 8} = 16.07 m{sup 2}*g{sup -1}). Furthermore, the particle size distribution measured as a function of the thermal treatment done shows changes on the powder size related to the changes observed in the uranium oxide stoichiometry. (authors)

  2. Constant Bet Size? Don't Bet on It! Testing Expected Utility Theory on Betfair Data

    OpenAIRE

    Frantisek Kopriva

    2015-01-01

    I analyze the risk preferences of bettors using data from the world's largest betting exchange, Betfair. The assumption of a constant bet size, commonly used in the current literature, leads to an unrealistic model of bettors' decision making as a choice between a high return - low variance and low return - high variance bet, automatically implying risk-loving preferences of bettors. However, the data show that bettors bet different amounts on different odds. Thus, simply by introducing the c...

  3. Pore scale heterogeneity in the mineral distribution and surface area of porous rocks

    Science.gov (United States)

    Lai, Peter; Moulton, Kevin; Krevor, Samuel

    2014-05-01

    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 carbon dioxide 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]. The objective of this study was to quantify heterogeneity in reactive surface and observe the extent of its non-normal character. In this study we describe our work in using micron-scale x-ray imaging and other spectroscopic techniques for the purpose of describing the statistical distribution of reactive surface area within a porous medium, and identifying specific mineral phases and their distribution in 3-dimensions. Using in-house image processing techniques and auxilary charactersation 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 nitrogen BET surface area and backscattered electron imaging measurements of the CT-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

  4. 30 CFR 817.95 - Stabilization of surface areas.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Stabilization of surface areas. 817.95 Section 817.95 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE... ACTIVITIES § 817.95 Stabilization of surface areas. (a) All exposed surface areas shall be protected...

  5. 30 CFR 816.95 - Stabilization of surface areas.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Stabilization of surface areas. 816.95 Section 816.95 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE... ACTIVITIES § 816.95 Stabilization of surface areas. (a) All exposed surface areas shall be protected...

  6. Accessible surface area from NMR chemical shifts

    International Nuclear Information System (INIS)

    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

  7. Quantification of surface amorphous content using dispersive surface energy: the concept of effective amorphous surface area.

    Science.gov (United States)

    Brum, Jeffrey; Burnett, Daniel

    2011-09-01

    We investigate the use of dispersive surface energy in quantifying surface amorphous content, and the concept of effective amorphous surface area is introduced. An equation is introduced employing the linear combination of surface area normalized square root dispersive surface energy terms. This equation is effective in generating calibration curves when crystalline and amorphous references are used. Inverse gas chromatography is used to generate dispersive surface energy values. Two systems are investigated, and in both cases surface energy data collected for physical mixture samples comprised of amorphous and crystalline references fits the predicted response with good accuracy. Surface amorphous content of processed lactose samples is quantified using the calibration curve, and interpreted within the context of effective amorphous surface area. Data for bulk amorphous content is also utilized to generate a thorough picture of how disorder is distributed throughout the particle. An approach to quantifying surface amorphous content using dispersive surface energy is presented. Quantification is achieved by equating results to an effective amorphous surface area based on reference crystalline, and amorphous materials. PMID:21725707

  8. 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

  9. 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

  10. Spatial variability of specific surface area of arable soils in Poland

    Science.gov (United States)

    Sokolowski, S.; Sokolowska, Z.; Usowicz, B.

    2012-04-01

    Evaluation of soil spatial variability is an important issue in agrophysics and in environmental research. Knowledge of spatial variability of physico-chemical properties enables a better understanding of several processes that take place in soils. In particular, it is well known that mineralogical, organic, as well as particle-size compositions of soils vary in a wide range. Specific surface area of soils is one of the most significant characteristics of soils. It can be not only related to the type of soil, mainly to the content of clay, but also largely determines several physical and chemical properties of soils and is often used as a controlling factor in numerous biological processes. Knowledge of the specific surface area is necessary in calculating certain basic soil characteristics, such as the dielectric permeability of soil, water retention curve, water transport in the soil, cation exchange capacity and pesticide adsorption. The aim of the present study is two-fold. First, we carry out recognition of soil total specific surface area patterns in the territory of Poland and perform the investigation of features of its spatial variability. Next, semivariograms and fractal analysis are used to characterize and compare the spatial variability of soil specific surface area in two soil horizons (A and B). Specific surface area of about 1000 samples was determined by analyzing water vapor adsorption isotherms via the BET method. The collected data of the values of specific surface area of mineral soil representatives for the territory of Poland were then used to describe its spatial variability by employing geostatistical techniques and fractal theory. Using the data calculated for some selected points within the entire territory and along selected directions, the values of semivariance were determined. The slope of the regression line of the log-log plot of semi-variance versus the distance was used to estimate the fractal dimension, D. Specific surface area

  11. 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.

  12. 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...

  13. 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.

  14. 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

  15. 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

  16. Predicting skin deficits through surface area measurements in ear reconstruction and adult ear surface area norms.

    Science.gov (United States)

    Yazar, Memet; Sevim, Kamuran Zeynep; Irmak, Fatih; Yazar, Sevgi Kurt; Yeşilada, Ayşin Karasoy; Karşidağğ, Semra Hacikerim; Tatlidede, Hamit Soner

    2013-07-01

    Ear reconstruction is one of the most challenging procedures in plastic surgery practice. Many studies and techniques have been described in the literature for carving a well-pronounced framework. However, just as important as the cartilage framework is the ample amount of delicate skin coverage of the framework. In this report, we introduce an innovative method of measuring the skin surface area of the auricle from a three-dimensional template created from the healthy ear.The study group consisted of 60 adult Turkish individuals who were randomly selected (30 men and 30 women). The participant ages ranged from 18 to 45 years (mean, 31.5 years), and they had no history of trauma or congenital anomalies. The template is created by dividing the ear into aesthetic subunits and using ImageJ software to estimate the necessary amount of total skin surface area required.Reconstruction of the auricle is a complicated process that requires experience and patience to provide the auricular details. We believe this estimate will shorten the learning curve for residents and surgeons interested in ear reconstruction and will help surgeons obtain adequate skin to drape over the well-sculpted cartilage frameworks by providing a reference list of total ear skin surface area measurements for Turkish men and women. PMID:23851770

  17. 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.

  18. 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.

  19. Effects of expertise on football betting

    OpenAIRE

    Khazaal Yasser; Chatton Anne; Billieux Joël; Bizzini Lucio; Monney Grégoire; Fresard Emmanuelle; Thorens Gabriel; Bondolfi Guido; El-Guebaly Nady; Zullino Daniele; Khan Riaz

    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...

  20. Information processing in children's choices among bets

    OpenAIRE

    Hommers, Wilfried

    2010-01-01

    Children's information processing of risky choice alternatives was investigated in two studies without using verbal reports. In Study 1, the ability to integrate the probabilities and the payoffs of simple bets was examined using the rating scale methodology. Children's choices among three of those simple bets were recorded also. By cross-classifying the children's choice and rating behavior it was shown that a three-stage developmental hypothesis of decision making is not sufficient. A four-...

  1. Impacts of water surface area of watershed on design flood

    Directory of Open Access Journals (Sweden)

    Qing-hua ZHANG

    2014-01-01

    Full Text Available In order to analyze the impact of the water surface area of a watershed on the design flood, the watershed was classified into a land watershed and a water surface watershed for flood flow calculation at the same time interval. Then, the design flood of the whole watershed was obtained by adding the two flood flows together. Using this method, we calculated design floods with different water surface areas of three reservoirs and analyzed the impact of water surface area on the flood volume and peak flow. The results indicate that larger water surface areas lead to greater impacts on the flood volume and peak flow. For the same watershed area, the impact of water surface area on the flood volume and peak flow is positively proportional to the flood frequency, i.e., the higher the frequency, the greater the impact becomes.

  2. SURFACE WATER QUALITY MANAGEMENT IN PRAHOVA AREA

    Directory of Open Access Journals (Sweden)

    CASEN PANAITESCU

    2014-05-01

    Full Text Available To achieve an appropriate management strategy was monitored surface water quality in the county of Prahova. In this regard were determinate major physical and chemical indicators: pH, BOD5, COD, nitrates, nitrites, and suspended solids. Depending on the value of the data obtained was identified water quality classes corresponding to each surface water body studied. The correlation values obtained with the best solutions for water service and maintenance of water courses is a management plan for surface water in the county of Prahova. The novelty of the paper consists of study of water resources in the county and not in the Basin as is done at present by the Romanian Waters National Administration

  3. 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. PMID:25531980

  4. 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.

  5. 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.

  6. On the specific surface area of nanoporous materials

    NARCIS (Netherlands)

    Detsi, E.; De Jong, E.; Zinchenko, A.; Vukovic, Z.; Vukovic, I.; Punzhin, S.; Loos, K.; ten Brinke, G.; De Raedt, H. A.; Onck, P. R.; De Hosson, J. T. M.

    2011-01-01

    A proper quantification of the specific surface area of nanoporous materials is necessary for a better understanding of the properties that are affected by the high surface-area-to-volume ratio of nanoporous metals, nanoporous polymers and nanoporous ceramics. In this paper we derive an analytical e

  7. 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…

  8. Impacts of water surface area of watershed on design flood

    OpenAIRE

    Zhang, Qing-Hua; Yan-fang DIAO; Dong, Jie

    2014-01-01

    In order to analyze the impact of the water surface area of a watershed on the design flood, the watershed was classified into a land watershed and a water surface watershed for flood flow calculation at the same time interval. Then, the design flood of the whole watershed was obtained by adding the two flood flows together. Using this method, we calculated design floods with different water surface areas of three reservoirs and analyzed the impact of water surface area on the flood volume an...

  9. 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,...

  10. Plasma-Engraved Co3 O4 Nanosheets with Oxygen Vacancies and High Surface Area for the Oxygen Evolution Reaction.

    Science.gov (United States)

    Xu, Lei; Jiang, Qianqian; Xiao, Zhaohui; Li, Xingyue; Huo, Jia; Wang, Shuangyin; Dai, Liming

    2016-04-18

    Co3 O4 , which is of mixed valences Co(2+) and Co(3+) , has been extensively investigated as an efficient electrocatalyst for the oxygen evolution reaction (OER). The proper control of Co(2+) /Co(3+) ratio in Co3 O4 could lead to modifications on its electronic and thus catalytic properties. Herein, we designed an efficient Co3 O4 -based OER electrocatalyst by a plasma-engraving strategy, which not only produced higher surface area, but also generated oxygen vacancies on Co3 O4 surface with more Co(2+) formed. The increased surface area ensures the Co3 O4 has more sites for OER, and generated oxygen vacancies on Co3 O4 surface improve the electronic conductivity and create more active defects for OER. Compared to pristine Co3 O4 , the engraved Co3 O4 exhibits a much higher current density and a lower onset potential. The specific activity of the plasma-engraved Co3 O4 nanosheets (0.055 mA cm(-2) BET at 1.6 V) is 10 times higher than that of pristine Co3 O4 , which is contributed by the surface oxygen vacancies. PMID:26990905

  11. 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...

  12. Sintering Effects on Morphology, Thermal Stability and Surface Area of Sol-Gel Derived Nano-Hydroxyapatite Powder

    Science.gov (United States)

    Kapoor, Seema; Batra, Uma; Kohli, Suchita

    2011-12-01

    Hydroxyapatite (HAP) ceramics have been recognized as substitute materials for bone and teeth in orthopedic and dentistry field due to their chemical and biological similarity to human hard tissue. The nanosized and nanocrystalline forms of HAP have great potential to revolutionize the hard tissue-engineering field, starting from bone repair and augmentation to controlled drug delivery systems. This paper reports the synthesis of biomimetic nano-hydroxyapatite (HAP) by sol-gel method using calcium nitrate tetrahydrate (CNT) and potassium dihydrogen phosphate (KDP) as calcium and phosphorus precursors, respectively to obtain a desired Ca/P ratio of 1.67. Deionized water was used as a diluting media for HAP sol preparation and ammonia was used to adjust the pH to 11. After aging, the HAP gel was dried at 55 °C and sintered to different temperatures (200 °C, 400 °C, 600 °C, 800 °C, 1000 °C and 1200 °C). The dried and sintered powders were characterized for phase composition using Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). The particle size and morphology was studied using transmission electron microscopy (TEM). The thermal behavior of the dried HAP nanopowder was studied in the temperature range of 55 °C to 1000 °C using thermal gravimetric analyser (TGA). The BET surface area of absorbance was determined by Nitrogen adsorption using Brunauer-Emmett-Teller (BET) method. The presence of characteristic peaks of the phosphate and OH groups in FTIR spectrums confirmed the formation of pure HAP in dried as well as sintered powders. XRD results also confirmed the formation of stoichiometric nano-HAP. Sintering revealed that with increase in temperature, both the crystallinity and crystallite size of nano-HAP particles increased. The synthesized nano-HAP powder was found to be stable upto 1000 °C without any additional phase other than HAP, whereas peak of β-TCP (tricalcium phosphate) was observed at 1200 °C. Photomicrograph of

  13. Bookmaker and pari-mutuel betting

    DEFF Research Database (Denmark)

    Koch, Alexander; Shing, Hui-Fai

    2008-01-01

    and persistent in bookmaker markets than in pari-mutuel markets; the latter sometimes exhibit no bias or a reverse FL bias. Our results help understand these differences: the odds grid in bookmaker markets leads to a built-in FL bias, whereas that used in pari-mutuel betting pushes these markets toward a reverse...

  14. Area minimizing surfaces in mean convex 3-manifolds

    OpenAIRE

    Coşkunüzer, Barış; Bourni, Theodora

    2015-01-01

    J. reine angew. Math. 704 (2015), 135–167 Journal für die reine und angewandte Mathematik DOI 10.1515/ crelle-2013-0050 © De Gruyter 2015 Area minimizing surfaces in mean convex 3-manifolds By Theodora Bourni at Berlin and Baris Coskunuzer at Istanbul Abstract. In this paper, we give several results on area minimizing surfaces in strictly mean convex 3-manifolds. First, we study the genus of absolutely area minimizing surfaces in a compact, orientable, strictly mean conve...

  15. Low-temperature preparation of nanocrystalline TiO{sub 2} photocatalyst with a very large specific surface area

    Energy Technology Data Exchange (ETDEWEB)

    Liu, A.R. [Department of Chemistry, Xuchang University, Xuchang 461000 (China)]. E-mail: ar_liu1948@yahoo.com.cn; Wang, S.M. [Department of Chemistry, Xuchang University, Xuchang 461000 (China); Zhao, Y.R. [Department of Chemistry, Xuchang University, Xuchang 461000 (China); Zheng, Z. [Institute of Advanced Materials, Xuchang University, Xuchang, 461000 (China)

    2006-09-10

    A facile method for obtaining highly photoactive bi-phase TiO{sub 2} photocatalyst with a small crystalline size and very large specific surface area was developed. This was simply done by hydrolysis of titanium tetraisopropoxide (TTIP) in pure water at 70 deg. C and followed by drying at 100 deg. C. The prepared TiO{sub 2} powder samples were characterized with X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and BET surface areas. The photocatalytic activity was evaluated by the photocatalytic oxidation of acetone in air. The results showed that the photocatalytic activity of the prepared TiO{sub 2} powder slightly exceeded that of Degussa P25. This might be attributed to the fact that the prepared TiO{sub 2} powder had a very large specific surface area (750 m{sup 2} g{sup -1}) and small crystallite size (about 5 nm), but relative low crystallinity, comparing with Degussa P25 photocatalyst.

  16. 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.

  17. 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.

  18. 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.

  19. Characterization of large area nanostructured surfaces using AFM measurements

    DEFF Research Database (Denmark)

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

    2012-01-01

    A surface characterisation study has been developed to validate an innovative tool making solution for nano patterning large areas via anodizing of aluminium (Al) and subsequent nickel electroforming. A surface topography characterization through atomic force microscopy (AFM) indicated a decrease...... relative to an average plane and the coefficient of variation of the fitted features curvature radius....

  20. 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.

  1. Specific surface area as a maturity index of lunar fines

    Science.gov (United States)

    Gammage, R. B.; Holmes, H. F.

    1975-01-01

    Mature surface fines have an equilibrium specific surface area of about 0.6 sq m/g the equivalent mean particle size being about 3 microns. The adsorption behavior of inert gases (reversible isotherms) indicates that the particles are also nonporous in the size range of pores from 10 to 3000 A. Apparently, in mature soils there is a balance in the forces which cause fining, attrition, pore filling, and growth of lunar dust grains. Immature, lightly irradiated soils usually have coarser grains which reduce in size as aging proceeds. The specific surface area, determined by nitrogen or krypton sorption at 77 K, is a valuable index of soil maturity.

  2. Discovery, Design, and Optimization of Isoxazole Azepine BET Inhibitors.

    Science.gov (United States)

    Gehling, Victor S; Hewitt, Michael C; Vaswani, Rishi G; Leblanc, Yves; Côté, Alexandre; Nasveschuk, Christopher G; Taylor, Alexander M; Harmange, Jean-Christophe; Audia, James E; Pardo, Eneida; Joshi, Shivangi; Sandy, Peter; Mertz, Jennifer A; Sims, Robert J; Bergeron, Louise; Bryant, Barbara M; Bellon, Steve; Poy, Florence; Jayaram, Hariharan; Sankaranarayanan, Ravichandran; Yellapantula, Sreegouri; Bangalore Srinivasamurthy, Nandana; Birudukota, Swarnakumari; Albrecht, Brian K

    2013-09-12

    The identification of a novel series of small molecule BET inhibitors is described. Using crystallographic binding modes of an amino-isoxazole fragment and known BET inhibitors, a structure-based drug design effort lead to a novel isoxazole azepine scaffold. This scaffold showed good potency in biochemical and cellular assays and oral activity in an in vivo model of BET inhibition. PMID:24900758

  3. 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.

  4. Surface area considerations for corroding N reactor fuel

    International Nuclear Information System (INIS)

    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 trueclose 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 trueclose 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

  5. 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.

  6. Students' and Teachers' Application of Surface Area to Volume Relationships

    Science.gov (United States)

    Taylor, Amy R.; Jones, M. Gail

    2013-02-01

    The National Science Education Standards emphasize teaching unifying concepts and processes such as basic functions of living organisms, the living environment, and scale (NRC 2011). Scale includes understanding that different characteristics, properties, or relationships within a system might change as its dimensions are increased or decreased (NRC 2011). One such relationship involves surface area to volume which is a pervasive concept that can be found throughout different sciences. This concept is important for students to not only understand the association of the two, but to also be able to apply this relationship in science contexts. The purpose of this study is to investigate the factors that influence the understanding surface area to volume relationships. This study examined middle school students', high school students', and science teachers' logical thinking skills (including proportional reasoning), visual-spatial skills, and understandings of surface area to volume relationships. Regression results indicated that participants' reasoning abilities and components of visual-spatial skills could be possible predictors for one's ability to understand surface area to volume relationships. Implications for teaching scale concepts such as surface area to volume relationships in the science classroom are discussed.

  7. 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.

  8. 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.

  9. Dependence of friction noise of rough surfaces with contact area

    OpenAIRE

    Le Bot, Alain; Dang, Viet Hung; Bou Chakra, Elie

    2012-01-01

    The noise emitted during the friction of rough surfaces is a wide band noise generated by the numerous impacts occuring between antagonist asperites of surfaces. This study presents an experiment which investigates the law between the acoustical power and a varying number of identical sliders i.e. the nominal contact area. It is found that in some cases, the acoustical power is proportional to the number of sliders while the sound is constant in some others. This result is explained by introd...

  10. Inequalities for the surface area of projections of convex bodies

    OpenAIRE

    Giannopoulos, Apostolos; Koldobsky, Alexander; Valettas, Petros

    2016-01-01

    We provide general inequalities that compare the surface area S(K) of a convex body K in ${\\mathbb R}^n$ to the minimal, average or maximal surface area of its hyperplane or lower dimensional projections. We discuss the same questions for all the quermassintegrals of K. We examine separately the dependence of the constants on the dimension in the case where K is in some of the classical positions or K is a projection body. Our results are in the spirit of the hyperplane problem, with sections...

  11. 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....... 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...

  12. 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

  13. 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.

  14. Ancient shell industry at Bet Dwarka island

    Digital Repository Service at National Institute of Oceanography (India)

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

    stream_size 23813 stream_content_type text/plain stream_name Curr_Sci_89_941.pdf.txt stream_source_info Curr_Sci_89_941.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 GENERAL ARTICLES... out in the season 2001 ? 02, to trace the cultural sequence of Figure 1. Turbinella pyrum discovered from Bet Dwarka Island. GENERAL ARTICLES CURRENT SCIENCE, VOL. 89, NO. 6, 25 SEPTEMBER 2005 the Island and also t o understand...

  15. Bayesian logistic betting strategy against probability forecasting

    CERN Document Server

    Kumon, Masayuki; Takemura, Akimichi; Takeuchi, Kei

    2012-01-01

    We propose a betting strategy based on Bayesian logistic regression modeling for the probability forecasting game in the framework of game-theoretic probability by Shafer and Vovk (2001). We prove some results concerning the strong law of large numbers in the probability forecasting game with side information based on our strategy. We also apply our strategy for assessing the quality of probability forecasting by the Japan Meteorological Agency. We find that our strategy beats the agency by exploiting its tendency of avoiding clear-cut forecasts.

  16. Solvent accessible surface area (ASA) of simulated phospholipid membranes

    DEFF Research Database (Denmark)

    Tuchsen, E.; Jensen, Morten Østergaard; Westh, P.

    2003-01-01

    The membrane-solvent interface has been investigated through calculations of the solvent accessible surface area (ASA) for simulated membranes of DPPC and POPE. For DPPC at 52 degreesC we found an ASA of 126 +/- 8 Angstrom(2) per lipid molecule, equivalent to twice the projected lateral area...... compensated by increased exposure of the ethylene and phosphate moieties. The ASA of the polar moieties Of (PO4, NH3 and COO) constitutes 65% of the total accessible area for POPE, making this interface more polar than that of DPPC. It is suggested that ASA information can be valuable in attempts...

  17. 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...

  18. Surface water and groundwater interaction in Marala - Khanki area, Punjab

    International Nuclear Information System (INIS)

    Isotope hydrological investigations were carried out in two selected areas of Indus Basin viz. Haripur Area and Chashma- Taunsa Area for elucidating various aspects of surface water and groundwater interaction. Groundwater samples were collected on seasonal basis (low and high river discharge periods) while surface water samples were collected more frequently (weekly or monthly basis). Isotopic data suggested that there is no contribution of surface water to groundwater recharge in Haripur Area and rain is the prevailing source of groundwater recharge. The data further revealed that isotopic values of the Haripur pocket of Tarbela Lake are higher than those of Main Lake / Indus River meaning that there is a significant contribution of base flow in this pocket. Indus River appeared to be the dominant source of groundwater recharge at most of the locations in Chashma- Taunsa Area. Isotopic data of Indus River showed an increase at Taunsa as compared to Chashma in low flow period indicating the high contribution of base flow at this point in time. Stable isotopes were successfully used to quantify the base flow contribution. (author)

  19. 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.

  20. 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.

  1. 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......, 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...

  2. Excess surface area in bioelectrochemical systems causes ion transport limitations

    Science.gov (United States)

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

    2014-01-01

    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: 1) showing that serially increasing NaCl concentration up to 200 mM increased current linearly up to a total of +273% vs. 0 mM NaCl under advective conditions, 2) growing the biofilm with a starting concentration of 200 mM NaCl, which led to a maximum current increase of 400% vs. current generation without NaCl, and 3) showing that un-colonized surface area remained even after steady-state current was reached. After accounting for iR effects, we confirmed that the excess surface area existed despite a non-zero overpotential at the electrode surface. 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. PMID:25421463

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

    International Nuclear Information System (INIS)

    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. (orig./WL)

  4. Body surface area determined by whole-body CT scanning

    DEFF Research Database (Denmark)

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

    2016-01-01

    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...

  5. 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.

  6. 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.

  7. 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.

  8. Adsorption of naphthenic acids on high surface area activated carbons.

    Science.gov (United States)

    Iranmanesh, Sobhan; Harding, Thomas; Abedi, Jalal; Seyedeyn-Azad, Fakhry; Layzell, David B

    2014-01-01

    In oil sands mining extraction, water is an essential component; however, the processed water becomes contaminated through contact with the bitumen at high temperature, and a portion of it cannot be recycled and ends up in tailing ponds. The removal of naphthenic acids (NAs) from tailing pond water is crucial, as they are corrosive and toxic and provide a substrate for microbial activity that can give rise to methane, which is a potent greenhouse gas. In this study, the conversion of sawdust into an activated carbon (AC) that could be used to remove NAs from tailings water was studied. After producing biochar from sawdust by a slow-pyrolysis process, the biochar was physically activated using carbon dioxide (CO2) over a range of temperatures or prior to producing biochar, and the sawdust was chemically activated using phosphoric acid (H3PO4). The physically activated carbon had a lower surface area per gram than the chemically activated carbon. The physically produced ACs had a lower surface area per gram than chemically produced AC. In the adsorption tests with NAs, up to 35 mg of NAs was removed from the water per gram of AC. The chemically treated ACs showed better uptake, which can be attributed to its higher surface area and increased mesopore size when compared with the physically treated AC. Both the chemically produced and physically produced AC provided better uptake than the commercially AC. PMID:24766592

  9. 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...

  10. 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.

  11. Aspects of surface and environment protection in German mining areas

    Institute of Scientific and Technical Information of China (English)

    FRANK Otto

    2009-01-01

    Hard coal mining in the German Ruhr district has a tradition of more than 200 years. Starting in the south near the river Ruhr with mining of seams near to the surface, mining wandered to the north with coal seams deeper and deeper. In the same way all environmental effects of mining wandered from south to north, as there are abandoned mining sites, contaminated areas, burning mining dumps, subsided areas and gas accesses at day ground. This all happened in a very high populated area with more than four million inhabitants. Therefore Germany has a long tradition in solving environmental problems of mining activities. The very good interaction of mine authority, mining companies and the mine workers' union is the main reason why the problems of decreasing mining activities in Germany were solved without economic, environmental or social hazards.

  12. 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.

  13. Influence of spatial heterogeneity of local surface albedo on the area-averaged surface albedo retrieved from airborne irradiance measurements

    OpenAIRE

    E. Jäkel; M. Wendisch; Mayer, Bernhard

    2013-01-01

    Spectral airborne upward and downward irradiance measurements are used to derive the area-averaged surface albedo. Real surfaces are not homogeneous in their reflectivity. Therefore, this work studies the effects of the heterogeneity of surface reflectivity on the area-averaged surface albedo to quantify how well aircraft measurements can resolve the small-scale variability of the local surface albedo.

  14. 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.).

  15. Regression Tests and the Efficiency of Fixed Odds Betting Markets

    NARCIS (Netherlands)

    Koning, Ruud H.

    2012-01-01

    The informational content of odds posted in sports betting market has been an ongoing topic of research. In this paper, I test whether fixed odds betting markets in soccer are informationally efficient. The contributions of the paper are threefold: first, I propose a simple yet flexible statistical

  16. 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..., betting, and lotteries. An employee shall not participate, while on Government-owned or leased property or..., in conducting a lottery or pool, in a game for money or property, or in selling or purchasing...

  17. 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... lottery or pool, a game for money or property, or in selling or purchasing a numbers slip or...

  18. 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...

  19. 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. PMID:27498825

  20. On Loss Aversion, Level-1 Reasoning, and Betting

    DEFF Research Database (Denmark)

    Erev, Ido; Gilat-Yihyie, Sharon; Marchiori, Davide;

    2014-01-01

    . The results reflect two reasons for the high betting rate: initial tendency to participate and slow learning. Under certain conditions, the observed betting rate was higher than the rate predicted under random choice even after 250 trials with immediate feedback. These results can be captured with a model......Previous research suggests that human reaction to risky opportunities reflects two contradicting biases: “loss aversion”, and “limited level of reasoning” that leads to overconfidence. Rejection of attractive gambles is explained by loss aversion, while counterproductive risk seeking is attributed...... to limited level of reasoning. The current research highlights a shortcoming of this popular (but often implicit) “contradicting biases” assertion. Studies of “negative-sum betting games” reveal high rate of counterproductive betting even when limited level of reasoning and loss aversion imply no betting...

  1. A high surface area tunnel-type α-MnO2 nanorod cathode by a simple solvent-free synthesis for rechargeable aqueous zinc-ion batteries

    Science.gov (United States)

    Alfaruqi, Muhammad Hilmy; Islam, Saiful; Gim, Jihyeon; Song, Jinju; Kim, Sungjin; Pham, Duong Tung; Jo, Jeonggeun; Xiu, Zhiliang; Mathew, Vinod; Kim, Jaekook

    2016-04-01

    Tunnel-type α-MnO2 with a nanorod morphology was prepared via a simple solvent-free synthesis method for use in aqueous zinc-ion battery (ZIB). This synthesis method produced α-MnO2 with a high BET surface area of 153 m2 g-1. α-MnO2 electrode demonstrated remarkable zinc storage properties (first and second discharge capacities of 323 and 270 mAh g-1 at 16 mA g-1) with good capacity retentions and rate capability. After charging within only 60 s, the α-MnO2 nanorod cathode delivered a considerable discharge capacity of 115 mAh g-1 when cycled at current density of 16 mA g-1.

  2. Water-Stable Zirconium-Based Metal-Organic Framework Material with High-Surface Area and Gas-Storage Capacities

    Energy Technology Data Exchange (ETDEWEB)

    Gutov, OV; Bury, W; Gomez-Gualdron, DA; Krungleviciute, V; Fairen-Jimenez, D; Mondloch, JE; Sarjeant, AA; Al-Juaid, SS; Snurr, RQ; Hupp, JT; Yildirim, T; Farha, OK

    2014-08-14

    We designed, synthesized, and characterized a new Zr-based metal-organic framework material, NU-1100, with a pore volume of 1.53 ccg(-1) and Brunauer-Emmett-Teller (BET) surface area of 4020 m(2)g(-1); to our knowledge, currently the highest published for Zr-based MOFs. CH4/CO2/H-2 adsorption isotherms were obtained over a broad range of pressures and temperatures and are in excellent agreement with the computational predictions. The total hydrogen adsorption at 65 bar and 77 K is 0.092 gg(-1), which corresponds to 43 gL(-1). The volumetric and gravimetric methane-storage capacities at 65 bar and 298 K are approximately 180 v(STP)/v and 0.27 gg(-1), respectively.

  3. 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.

  4. Leaching of metal(loid)s from a construction material: influence of the particle size, specific surface area and ionic strength.

    Science.gov (United States)

    Schmukat, A; Duester, L; Ecker, D; Schmid, H; Heil, C; Heininger, P; Ternes, T A

    2012-08-15

    Construction materials are tested worldwide for a potential release of dangerous substances to prevent adverse effects on humans and biota. It is crucial to identify and understand the processes which are decisive for the release of hazardous substances. The current study compares the results of different test methods. Taking copper slag as model material, the influence of material particle size, eluant composition and ionic strength was tested. Ionic strength and salinity significantly influenced the release of metal(loid)s in the water phase. Furthermore, it was elucidated that colloids can cause methodological artefacts. The available specific surface area exhibited a positive correlation with the release of hazardous substances. The specific surface areas of materials were determined by the Brunauer, Emmett and Teller model (BET) and four other methods. The aluminium foil method showed the best results with regard to the statistical uncertainty, compared to a 3D laser scanning method. With help of the roughness factor λ it is possible to compare the results from surface area measurements with different material particle sizes (0-250 mm). This comparability offers the potential to match the release of metal(loid)s from laboratory studies with field applications and catchment area calculations/modelling, based on the release per m(2). PMID:22683212

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

    DEFF Research Database (Denmark)

    Kiderlen, Markus; Meschenmoser, Daniel

    2009-01-01

    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...

  6. High surface area graphene-supported metal chalcogenide assembly

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Tian -Fu [Texas A & M Univ., College Station, TX (United States); Feng, Dawei [Texas A & M Univ., College Station, TX (United States); Chen, Ying -Pin [Texas A & M Univ., College Station, TX (United States); Zou, Lanfang [Texas A & M Univ., College Station, TX (United States); Bosch, Mathieu [Texas A & M Univ., College Station, TX (United States); Yuan, Shuai [Texas A & M Univ., College Station, TX (United States); Wei, Zhangwen [Texas A & M Univ., College Station, TX (United States); Fordham, Stephen [Texas A & M Univ., College Station, TX (United States); Wang, Kecheng [Texas A & M Univ., College Station, TX (United States); Zhou, Hong -Cai [Texas A & M Univ., College Station, TX (United States)

    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.

  9. Topology-Guided Design and Syntheses of Highly Stable Mesoporous Porphyrinic Zirconium Metal-Organic Frameworks with High Surface Area

    Energy Technology Data Exchange (ETDEWEB)

    Liu, TF; Feng, DW; Chen, YP; Zou, LF; Bosch, M; Yuan, S; Wei, ZW; Fordham, S; Wang, KC; Zhou, HC

    2015-01-14

    Through a topology-guided strategy, a series of Zr-6-containing isoreticular porphyrinic metalorganic 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 Zr-8 cluster with a smaller Zr-6 cluster in a topologically identical framework. The high connectivity of the Zr-6 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.

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

    International Nuclear Information System (INIS)

    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% H2SiF6) and 100 ml, 0.297 M Na2CO3 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 N2 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 m2/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.

  11. 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.

  12. 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.

  13. Influence of spatial heterogeneity of local surface albedo on the area-averaged surface albedo retrieved from airborne irradiance measurements

    OpenAIRE

    E. Jäkel; M. Wendisch; Mayer, B.

    2012-01-01

    Spectral airborne upward and downward irradiance measurements are used to derive the area-averaged surface albedo. Real surfaces are not homogeneous in their reflectivity. Therefore, this work studies the effects of the heterogeneity of surface reflectivity on the area-averaged surface albedo to quantify how well aircraft measurements can resolve the small-scale variability of the local surface albedo. For that purpose spatially heterogeneous surface albedo maps were input into a 3-dimensiona...

  14. Influence of spatial heterogeneity of local surface albedo on the area-averaged surface albedo retrieved from airborne irradiance measurements

    OpenAIRE

    E. Jäkel; M. Wendisch; Mayer, B.

    2013-01-01

    Spectral airborne upward and downward irradiance measurements are used to derive the area-averaged surface albedo. Real surfaces are not homogeneous in their reflectivity. Therefore, this work studies the effects of the heterogeneity of surface reflectivity on the area-averaged surface albedo to quantify how well aircraft measurements can resolve the small-scale variability of the local surface albedo. For that purpose spatially heterogeneous surface albedo maps were inpu...

  15. 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.

  16. 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.

  17. 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......-indexed GFR vs. mean absolute GFR were analyzed with a t-test for paired data. Bland-Altman plot was used to analyze agreement between the indexed and absolute GFR values. RESULTS AND CONCLUSION: BSA-GFR in patients with a BSA

  18. 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.

  19. 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.

  20. 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. %.

  1. Surface water and groundwater interaction in Marala-Khanki area

    International Nuclear Information System (INIS)

    Isotope hydrological investigations were carried out in a selected sub-catchment of Indus Basin (Marala-Khanki Area) for elucidating various aspects of surface water and groundwater interaction. Groundwater samples were collected on seasonal basis (low and high river discharge periods) while surface water (Chenab River) samples were collected more frequently (weekly or monthly basis). Gamma /sup 18/O values of groundwater along the right bank are generally higher and vary over a narrow range of -3 to -6.5%. These values are close to the rain index. The data points of these samples lie below the local meteoric water line (LMWL) which indicates the evaporation effect. This trend is not altered even in the monsoon season when the river has very high discharge proving that the area receives recharge mainly from the rain and there is no significant contribution of river water. Data points pertaining to groundwater samples collected from the stations along the left bank of the river show large variations in gamma/sup 18/O and the values range from -10.2 to -2.5%. Some samples from this side indicate contribution of the river. Tritium and CFC dating suggest groundwater residence time ranging from >50 years to few years. The data further revealed that isotopic values of the river Chenab at Khanki (average gamma /sup 18/O and gamma /sup 2/H = -7.7% and -46%) are higher than those at Marala (average gamma /sup 18/O and gamma /sup 2/H = -9.4% and -56%). Enrichment of gamma/sup 18/O and gamma 2/H in river water at Khanki during low flow period as compared to Marala indicates the contribution of isotopically enriched base flow. Average base flow contribution in this river section during low flow period calculated by isotope data was about 30%. (orig./A.B.)

  2. Surface ozone in the urban area of Manaus, Amazonas, Brazil

    Science.gov (United States)

    Souza, R. A. F. D.; Costa, P. S.; Silva, C.; Godoi, R. M.; Martin, S. T.; Tota, J.; Barbosa, H. M.; Pauliquevis, T.; Ferreira De Brito, J.; Artaxo, P.; Manzi, A. O.; Wolf, S. A.; Cirino, G. G.

    2014-12-01

    When nitrogen oxides from vehicle and industrial emissions mix with volatile organic compounds from trees and plants with exposure to sunlight, a chemical reaction occurs contributing to ground-level ozone pollution. The preliminary results of the surface ozone study in urban area of Manaus, Amazonas State, Brazil, are presented for the first intensive operating period (IOP1) of the GoAmazon experiment (February/March 2014). Photochemical ozone production was found to be a regular process, with an afternoon maximum of the ozone mixing ratio of lower than 20 ppbv for cloudy days or clear sky weather. Typical ozone concentrations at mid-day were low (about 10 ppb). On the other hand, several high-value ozone episodes with surface ozone mixing ratios up to three times larger were registered during the dry season of 2013 (September/October). At the beginning of the wet season, the ozone concentration in Manaus decreased significantly, but diurnal variations can be found during the days with rainfall and other fast changes of meteorological conditions. Possible explanations of the nature of pulsations are discussed. Photochemical ozone production by local urban plumes of Manaus is named as a first possible source of the ozone concentration and biomass burning or power plant emissions are suggested as an alternative or an additional source.

  3. 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 (p<0.001) between built-up surfaces and spatial LST variations were observed in all the cities studied, with a higher impact during the warm/hot period than in the cool/cold ones. Daytime and nighttime LST slope patterns depend on the city size and relative urban 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

  4. Tests of the Efficiency of Racetrack Betting Using Bookmaker Odds

    OpenAIRE

    Ron Bird; Michael McCrae

    1987-01-01

    The objective of this study is to evaluate the informational efficiency of the market for betting on horse races. Whereas the price data used in previous studies have been drawn largely from totalizator (parimutuel) odds, the data used in this study are derived from bookmaker odds. The availability of a series of prices throughout betting facilitates the use of filter tests to evaluate market efficiency. We conclude that this gambling market is efficient in the use of information supplied via...

  5. 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...

  6. Lung deposited surface area size distributions of particulate matter in different urban areas

    Science.gov (United States)

    Kuuluvainen, Heino; Rönkkö, Topi; Järvinen, Anssi; Saari, Sampo; Karjalainen, Panu; Lähde, Tero; Pirjola, Liisa; Niemi, Jarkko V.; Hillamo, Risto; Keskinen, Jorma

    2016-07-01

    Lung deposited surface area (LDSA) concentration is considered as a relevant metric for the negative health effects of aerosol particles. We report for the first time the size distributions of the LDSA measured in urban air. The measurements were carried out in the metropolitan area of Helsinki, including mobile laboratory and stationary measurements in different outdoor environments, such as traffic sites, a park area, the city center and residential areas. The main instrument in this study was an electrical low pressure impactor (ELPI), which was calibrated in the field to measure the LDSA concentration. The calibration factor was determined to be 60 μm2/(cm3 pA). In the experiments, the LDSA size distributions were found to form two modes at the traffic sites and in the city center. Both of these traffic related particle modes, the nucleation mode and the soot mode, had a clear contribution to the total LDSA concentration. The average total concentrations varied from 12 to 94 μm2/cm3, measured in the park area and at the traffic site next to a major road, respectively. The LDSA concentration was found to correlate with the mass of fine particles (PM2.5), but the relation of these two metrics varied between different environments, emphasizing the influence of traffic on the LDSA. The results of this study provide valuable information on the total concentrations and size distributions of the LDSA for epidemiological studies. The size distributions are especially important in estimating the contribution of outdoor concentrations on the concentrations inside buildings and vehicles through size-dependent penetration factors.

  7. The winds regime of surface in the Colombian coffee area

    International Nuclear Information System (INIS)

    The characteristics of the address and gust of wind of the surface winds have been studied in 15 stations of the Colombian coffee area. It was found that the relief plays an important paper in the wind circulation so that during the day (7 a.m. - 7 p.m.) these they blow of the low sector toward the mountain and at night (7 p.m. - 7 a.m.) this situation is invested, that which is consistent with the characteristic pattern of circulation valley-mountain of the mountainous regions. For this fact, in most of the analyzed places a single day and night dominant address that it takes the orientation in that it is the respective hydrographic basin. It was not observed that the Alisios winds of the northeast and southeast modify the address settled down by the local circulation (valley-mountain) on the other hand a remarkable increase of the gust of wind was appreciated in July and August in the Florida and Ospina, stations located to the south of the country, as direct consequence of the Alisios of the southeast. The daily gust of wind in most of the studied places is low and it doesn't exceed of the 10 km/h, reason why it can consider that the Colombian coffee area is free of important damages for the action of the wind. Nevertheless, in some stations as Alban, Maracay and Paraguaicito the daily maximum gust of wind can surpass the 30 km/h and in occasions to cause damage mechanic to cultivations of high behavior and not well anchored facilities

  8. 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.

  9. Modeling surface area to volume effects on borosilicate glass dissolution

    International Nuclear Information System (INIS)

    We simulated the reaction of SRL-131 glass with equilibrated J-13 water in order to investigate the effects of surface area to volume ratio (SA/V) on glass dissolution. We show that glass-fluid ion exchange causes solution pH to rise to progressively higher values as SA/V increases. Because the ion exchange is rapid relative to the duration of the glass dissolution experiment, the pH effect does not scale with (SA/V)*time. Experiments compared at the same (SA/V)*time value therefore have different pHs, with higher pHs at higher SA/V ratios. Both experimental data and our simulation results show similar trends of increasing reaction rate as a function of SA/V ratio when scaled to (SA/V)*time. Glasses which react in systems of differing SA/V ratio therefore follow different reaction paths and high SA/V ratios cannot be used to generate data which accurately scales to long time periods unless the ion exchange effect is taken into account. We suggest some simple test designs which enable more reliable high. SA/V accelerated tests

  10. Bicontinuous ceramics with high surface area from block copolymer templates.

    Science.gov (United States)

    Hsueh, Han-Yu; Ho, Rong-Ming

    2012-06-01

    Mesoporous polymers with gyroid nanochannels can be fabricated from the self-assembly of degradable block copolymer, polystyrene-b-poly(L-lactide) (PS-PLLA), followed by hydrolysis of PLLA block. Well-defined polymer/ceramic nanohybrid materials with inorganic gyroid nanostructures in a PS matrix can be obtained by using the mesoporous PS as a template for sol-gel reaction. Titanium tetraisopropoxide (TTIP) is used as a precursor to give a model system for the fabrication of metal oxide nanostructures from reactive transition metal alkoxides. By controlling the rates of capillary-driven pore filling and sol-gel reaction, the templated synthesis can be well-developed. Also, by taking advantage of calcination, bicontinuous TiO(2) with controlled crystalline phase (i.e., anatase phase) can be fabricated after removal of the PS template and crystallization of TiO(2) by calcination leading to high photocatalytic efficiency. This new approach provides an easy way to fabricate high-surface-area and high-porosity ceramics with self-supporting structure and controlled crystalline phase for practical applications. As a result, a platform technology to fabricate precisely controlled polymer/ceramic nanohybrids and mesoporous ceramic materials can be established. PMID:22530553

  11. 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

  12. Determination of surface-accessible acidic hydroxyls and surface area of lignin by cationic dye adsorption.

    Science.gov (United States)

    Sipponen, Mika Henrikki; Pihlajaniemi, Ville; Littunen, Kuisma; Pastinen, Ossi; Laakso, Simo

    2014-10-01

    A new colorimetric method for determining the surface-accessible acidic lignin hydroxyl groups in lignocellulose solid fractions was developed. The method is based on selective adsorption of Azure B, a basic dye, onto acidic hydroxyl groups of lignin. Selectivity of adsorption of Azure B on lignin was demonstrated using lignin and cellulose materials as adsorbents. Adsorption isotherms of Azure B on wheat straw (WS), sugarcane bagasse (SGB), oat husk, and isolated lignin materials were determined. The maximum adsorption capacities predicted by the Langmuir isotherms were used to calculate the amounts of surface-accessible acidic hydroxyl groups. WS contained 1.7-times more acidic hydroxyls (0.21 mmol/g) and higher surface area of lignin (84 m(2)/g) than SGB or oat husk materials. Equations for determining the amount of surface-accessible acidic hydroxyls in solid fractions of the three plant materials by a single point measurement were developed. A method for high-throughput characterization of lignocellulosic materials is now available. PMID:25033327

  13. Is the surface area of the red cell membrane skeleton locally conserved?

    OpenAIRE

    Fischer, T M

    1992-01-01

    The incompressibility of the lipid bilayer keeps the total surface area of the red cell membrane constant. Local conservation of membrane surface area requires that each surface element of the membrane skeleton keeps its area when its aspect ratio is changed. A change in area would require a flow of lipids past the intrinsic proteins to which the skeleton is anchored. in fast red cell deformations, there is no time for such a flow. Consequently, the bilayer provides for local area conservatio...

  14. 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.

  15. Mercury Underpotential Deposition to Determine Iridium and Iridium Oxide Electrochemical Surface Areas

    Energy Technology Data Exchange (ETDEWEB)

    Alia, Shaun M.; Hurst, Katherine E.; Kocha, Shyam S.; Pivovar, Bryan S.

    2016-06-02

    Determining the surface areas of electrocatalysts is critical for separating the key properties of area-specific activity and electrochemical surface area from mass activity. Hydrogen underpotential deposition and carbon monoxide oxidation are typically used to evaluate iridium (Ir) surface areas, but are ineffective on oxides and can be sensitive to surface oxides formed on Ir metals. Mercury underpotential deposition is presented in this study as an alternative, able to produce reasonable surface areas on Ir and Ir oxide nanoparticles, and able to produce similar surface areas prior to and following characterization in oxygen evolution. Reliable electrochemical surface areas allow for comparative studies of different catalyst types and the characterization of advanced oxygen evolution catalysts. They also enable the study of catalyst degradation in durability testing, both areas of increasing importance within electrolysis and electrocatalysis.

  16. 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.

  17. 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

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

    OpenAIRE

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

    2014-01-01

    ABSTRACT 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 s...

  19. 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].

  20. Soil roughness, slope and surface storage relationship for impervious areas

    Science.gov (United States)

    Borselli, Lorenzo; Torri, Dino

    2010-11-01

    SummaryThe study of the relationships between surface roughness, local slope gradient and maximum volume of water storage in surface depressions is a fundamental element in the development of hydrological models to be used in soil and water conservation strategies. Good estimates of the maximum volume of water storage are important for runoff assessment during rainfall events. Some attempts to link surface storage to parameters such as indices of surface roughness and, more rarely, local gradient have been proposed by several authors with empirical equations often conflicting between them and usually based on a narrow range of slope gradients. This suggests care in selecting any of the proposed equations or models and invites one to verify the existence of more realistic experimental relationships, based on physical models of the surfaces and valid for a larger range of gradients. The aim of this study is to develop such a relation for predicting/estimating the maximum volume of water that a soil surface, with given roughness characteristics and local slope gradient, can store. Experimental work has been carried out in order to reproduce reliable rough surfaces able to maintain the following properties during the experimental activity: (a) impervious surface to avoid biased storage determination; (b) stable, un-erodible surfaces to avoid changes of retention volume during tests; (c) absence of hydrophobic behaviour. To meet the conditions a-c we generate physical surfaces with various roughness magnitude using plasticine (emulsion of non-expansible clay and oil). The plasticine surface, reproducing surfaces of arable soils, was then wetted and dirtied with a very fine timber sawdust. This reduced the natural hydrophobic behaviour of the plasticine to an undetectable value. Storage experiments were conducted with plasticine rough surfaces on top of large rigid polystyrene plates inclined at different slope gradient: 2%, 5%, 10%, 20%, 30%. Roughness data collected on

  1. Extracting local information from crowds through betting markets

    Science.gov (United States)

    Weijs, Steven

    2015-04-01

    In this research, a set-up is considered in which users can bet against a forecasting agency to challenge their probabilistic forecasts. From an information theory standpoint, a reward structure is considered that either provides the forecasting agency with better information, paying the successful providers of information for their winning bets, or funds excellent forecasting agencies through users that think they know better. Especially for local forecasts, the approach may help to diagnose model biases and to identify local predictive information that can be incorporated in the models. The challenges and opportunities for implementing such a system in practice are also discussed.

  2. Determining eyeball surface area directly exposed to the effects of external factors.

    Science.gov (United States)

    Juliszewski, Tadeusz; Kadłuczka, Filip; Kiełbasa, Paweł

    2016-01-01

    This article discusses determining the surface area of eyeballs of men and women exposed to the direct effects of external factors in the working environment. For one eye, the mean surface is 172-182 mm(2). The determined surface area can be used in formulas for calculating the exposure of eyeballs to harmful chemical substances in workplace air. PMID:26758027

  3. 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.

  4. 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.

  5. Betão eco-eficiente : o futuro da indústria do betão pronto

    OpenAIRE

    Torgal, Fernando Pacheco; Jalali, Said

    2011-01-01

    O futuro da indústria de betão pronto passa inevitavelmente por um esforço continuado na redução dos impactos ambientais do betão. O presente artigo apresenta nesse contexto alguns contributos para a eco-eficiência do referido material. Descrevem-se resumidamente os principais impactos ambientais associados à sua produção. Analisa-se o contributo decisivo proporcionado pela substituição parcial de cimento por adições pozolânicas e a importância da substituição de agregados naturais por agrega...

  6. Afghanistan: Håbet lever – og elektrikerne er tilkaldt

    DEFF Research Database (Denmark)

    Vestenskov, David

    2013-01-01

    bet for den civile afghaner kan til tider virke som et skamskudt fyrtårn, og det bliver næppe genopbygget af kritiske observationer og selvretfærdig debat. Operationens fokus forud for de udenlandske troppers exit er at udvikle sikkerhedsinstitutionerne og skabe arbejdspladser...

  7. 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...

  8. 18 CFR 1300.102 - Gambling, betting, and lotteries.

    Science.gov (United States)

    2010-04-01

    ... duties; or (b) Under section 7 of Executive Order 12353 (47 FR 12785, 3 CFR, 1982 Comp., p. 139) 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...

  9. 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... lotteries. An employee shall not participate while on Government-owned or leased property or while on duty... conducting a lottery or pool, in a game for money or property or in selling or purchasing a numbers slip...

  10. 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…

  11. 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.

  12. Surface roughness of minerals and implications for dissolution studies

    Science.gov (United States)

    Anbeek, Chris

    1992-04-01

    Large, naturally weathered mineral fragments are often ground and sieved to obtain samples for dissolution studies. If the fragments are ground to much smaller dimensions, the samples are normally assumed to contain one type of (fresh) surface only. A model has been developed to test the validity of this assumption. The model describes the surface roughness factor of ground mineral material as a function of grain size and can be used to: (1) estimate the roughness factors of the freshly created and the naturally weathered surfaces; (2) estimate the ratio of fresh to total surface area for the ground samples, both for geometric and for actual surfaces; and (3) check the internal consistency of surface area measurements. Literature data were evaluated for intensively ground size fractions of nine different naturally weathered feldspars. Roughness factors of freshly created surfaces ranged from 2.5-11. Roughness factors of naturally weathered surfaces ranged from 130-2600, which is much higher than is generally recognized for feldspars. Comparison with surface roughness estimates from Scanning Electron Microscopy strongly suggests that etch pit formation plays a minor role in the increase in actual surface area during natural weathering. Instead, virtually all increase in surface area must be attributed to the formation of internal surface structures like micropores. The model also showed that for these ground samples, the assumption of one type of (fresh) surface is approximately correct for the geometric surfaces. For the actual (BET) surfaces, ratios of fresh to total surface area varied over almost the entire range from 0 to 1. This demonstrates that, even after intensive grinding, samples from large, naturally weathered mineral fragments can still contain substantial proportions of weathered BET surface area. Thus, previous dissolution studies in terms of fresh BET surface only may have been misinterpreted.

  13. Determination of catchment area of surface water in gis for suitable land management

    OpenAIRE

    Kovačič, Primož

    2009-01-01

    The main purpose of this diploma thesis is defining the catchment areas of surface waters for suitable land management, which is also reflected on water quality. Besides basic concepts, legal backgrounds in Slovenia, which are related to water areas and water management, are introduced. The thesis presents the existing models of catchment areas of waters in Slovenia and it especially exposes the subsistent methodology of defining catchment areas of surface waters on the basis of digital eleva...

  14. 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.

  15. Trends in grain size and surface area of glacial and non-glacial alluvial sediments: Building a paleoclimate proxy for deep-time

    Science.gov (United States)

    Marra, K. R.; Keiser, L.; Soreghan, G. S.; Elwood-Madden, M.

    2011-12-01

    Extent of chemical and physical weathering in sediments depends upon climatic factors, which affect both the mode of sediment production and the rate of chemical reactions. Most glacial systems are capable of producing large amounts of fine-grained sediments, due to glacial grinding and abrasion, which increases the surface area of mineral constituents. Increased surface area enhances rates of chemical weathering despite cold temperatures, which are typically considered to limit rates of chemical reactions due to relatively high activation energies. The amount of chemical weathering in non-glacial systems depends upon erosion rates, although modes of sediment production differ, with temperature exerting a secondary control. To assess variations in weathering rates and products in cold-arid relative to semi-arid climates, sediment samples were collected every 500 m along 5-7 km fluvial transects in the Dry Valleys, Antarctica and the Wichita Mountains of Oklahoma, where bedrock (granitoid), drainage area, and relief are similar. Sediments were sieved for the gravel, sand, and mud (< 63 μm) fractions. The mud fraction was treated with acetic acid and hydrogen peroxide to remove carbonate and organics, and then analyzed for surface area (nitrogen absorption BET) and grain size. Preliminary grain size analysis of sediments from Clark Glacier stream (Wright Valley, Antarctica) shows the mud fraction coarsens with distance along a 5 km transect and surface area correspondingly decreases, suggesting weathering products (clays) are not being produced in this climate but are being dissolved. Sediments collected along a 5 km transect from Blue Beaver Creek in the Wichita Mountains show the opposite, wherein a downstream decrease in grain size and increase in surface area likely relate to precipitation of secondary weathering phases. XRD and whole-rock geochemical analyses are currently underway to further assess chemical weathering signatures in glacial and non

  16. 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

    2016-01-01

    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 bright)CD16-CD57-), and expressed the tissue-residency marker CD69. CXCR6+ NK produced fewer cytotoxic mediators and pro-inflammatory cytokines than the non-liver-specific CXCR6- fraction. Instead CXCR6+ NK could upregulate TRAIL, a key death ligand in hepatitis pathogenesis. CXCR6 demarcated liver NK into two transcriptionally distinct populations: T-bet(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. PMID:27210614

  17. Target surface area effects on hot electron dynamics from high intensity laser–plasma interactions

    Science.gov (United States)

    Zulick, C.; Raymond, A.; McKelvey, A.; Chvykov, V.; Maksimchuk, A.; Thomas, A. G. R.; Willingale, L.; Yanovsky, V.; Krushelnick, K.

    2016-06-01

    Reduced surface area targets were studied using an ultra-high intensity femtosecond laser in order to determine the effect of electron sheath field confinement on electron dynamics. X-ray emission due to energetic electrons was imaged using a {K}α imaging crystal. Electrons were observed to travel along the surface of wire targets, and were slowed mainly by the induced fields. Targets with reduced surface areas were correlated with increased hot electron densities and proton energies. Hybrid Vlasov–Fokker–Planck simulations demonstrated increased electric sheath field strength in reduced surface area targets.

  18. 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...

  19. 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)

  20. 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.

  1. 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.

  2. 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.

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

    OpenAIRE

    Olofsson, Helen; Ripa, Jörgen; Jonzén, Niclas

    2009-01-01

    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 see...

  4. 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

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

    International Nuclear Information System (INIS)

    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 there is

  6. 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.

  7. Contact Area and Temperature of Same-Parameter Fractal Surfaces in Sliding Process

    Directory of Open Access Journals (Sweden)

    Bingbing Liu

    2015-01-01

    Full Text Available To evaluate the ability of fractal parameters for characterizing tribological properties of surfaces, some stable fractal surfaces, which possess the same fractal dimension, scale factor and root-mean-square deviation of surface topography, were synthesized, and then simulated using finite element analysis to calculate the maximum temperature and contact area during sliding process. It was found that for same-parameter fractal surfaces the maximum temperature and contact area fluctuated dramatically. Thus, the tribological properties of surfaces can not be characterized by some simple parameters.

  8. In Search of a Fair Bet in the Lottery

    OpenAIRE

    Kent R. Grote; Victor A. Matheson

    2006-01-01

    Although state-operated lotto games have the worst average expected payoffs among common games of chance, because the jackpot can accumulate, the maximum expected payoff is potentially unlimited. It is possible, therefore, that lotto can exhibit a positive expected return. This paper examines 18,000 drawings in 34 American lotteries and finds approximately 1 percent of these drawings provided players with a fair bet. If it were possible for a bettor to purchase every possible combination, how...

  9. 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...... and catalytic activity; this was attributed to the presence of excess amorphous carbon in the carbide powder. TEM imaging and TGA-DTA results revealed a better correlation of the activity with the carbide particle size....

  10. Nitration of the pollen allergen bet v 1.0101 enhances the presentation of bet v 1-derived peptides by HLA-DR on human dendritic cells.

    Directory of Open Access Journals (Sweden)

    Anette C Karle

    Full Text Available Nitration of pollen derived allergens can occur by NO(2 and ozone in polluted air and it has already been shown that nitrated major birch (Betula verrucosa pollen allergen Bet v 1.0101 (Bet v 1 exhibits an increased potency to trigger an immune response. However, the mechanisms by which nitration might contribute to the induction of allergy are still unknown. In this study, we assessed the effect of chemically induced nitration of Bet v 1 on the generation of HLA-DR associated peptides. Human dendritic cells were loaded with unmodified Bet v 1 or nitrated Bet v 1, and the naturally processed HLA-DR associated peptides were subsequently identified by liquid chromatography-mass spectrometry. Nitration of Bet v 1 resulted in enhanced presentation of allergen-derived HLA-DR-associated peptides. Both the copy number of Bet v 1 derived peptides as well as the number of nested clusters was increased. Our study shows that nitration of Bet v 1 alters antigen processing and presentation via HLA-DR, by enhancing both the quality and the quantity of the Bet v 1-specific peptide repertoire. These findings indicate that air pollution can contribute to allergic diseases and might also shed light on the analogous events concerning the nitration of self-proteins.

  11. Surface winds in the Euro-Mediterranean area: the real resolution of numerical grids

    OpenAIRE

    Chèruy, F.; Speranza, A.; Sutera, A.; Tartaglione, N.

    2004-01-01

    Surface wind is a variable of great importance in forcing marine waves and circulations, modulating surface fluxes, etc. Surface wind defined on numerical grids is currently used in forecast-analysis, as well as in climatology. Gridded fields, however, suffer for systematic errors associated with the numerical procedures adopted in computing them. In this paper the climatology of surface wind produced by three different numerical models in the European-Mediterranean area is analyzed. The syst...

  12. Tuneable ultra high specific surface area Mg/Al-CO3 layered double hydroxides.

    Science.gov (United States)

    Chen, Chunping; Wangriya, Aunchana; Buffet, Jean-Charles; O'Hare, Dermot

    2015-10-01

    We report the synthesis of tuneable ultra high specific surface area Aqueous Miscible Organic solvent-Layered Double Hydroxides (AMO-LDHs). We have investigated the effects of different solvent dispersion volumes, dispersion times and the number of re-dispersion cycles specific surface area of AMO-LDHs. In particular, the effects of acetone dispersion on two different morphology AMO-LDHs (Mg3Al-CO3 AMO-LDH flowers and Mg3Al-CO3 AMO-LDH plates) was investigated. It was found that the amount of acetone used in the dispersion step process can significantly affect the specific surface area of Mg3Al-CO3 AMO-LDH flowers while the dispersion time in acetone is critical factor to obtain high specific surface area Mg3Al-CO3 AMO-LDH plates. Optimisation of the acetone washing steps enables Mg3Al-CO3 AMO-LDH to have high specific surface area up to 365 m(2) g(-1) for LDH flowers and 263 m(2) g(-1) for LDH plates. In addition, spray drying was found to be an effective and practical drying method to increase the specific surface area by a factor of 1.75. Our findings now form the basis of an effective general strategy to obtain ultrahigh specific surface area LDHs. PMID:26308729

  13. Flower-like nanostructure MNb2O6 (M = Mn, Zn) with high surface area: Hydrothermal synthesis and enhanced photocatalytic performance

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • MNb2O6 was prepared by a mild two-step hydrothermal method. • Their flower-like nanostructure morphology was studied by SEM and TEM. • High BET surface areas for MnNb2O6 (∼50 m2/g) and ZnNb2O6 (∼100 m2/g). • Band gap energies were estimated by UV–vis diffuse reflectance spectra. • Photocatalytic activities were evaluated under UV-light irradiation. - Abstract: Nano-scaled MNb2O6 (M = Mn, Zn) was successfully synthesized via a two-step hydrothermal method. It is important to control the exact pH of the reaction solution in order to obtain pure products. The as-prepared samples both crystallize in the columbite structure. Interestingly, the products possess a flower-like morphology in a pseudo-six-fold symmetry, which is in fact arrayed by two-dimensional nanosheets. Their surface areas (51 m2/g for MnNb2O6 and 103 m2/g for ZnNb2O6) are about 25–50 times of those prepared by solid state reaction. UV–vis diffuse reflectance spectra show the nano-scaled sample has a stronger absorption and a narrower band gap than its bulk form. The estimated band gap energies are 2.70 eV (MnNb2O6) and 3.77 eV (ZnNb2O6), respectively. The nano-scaled ZnNb2O6 exhibits a double enhancement of photocatalytic activity in the decolorization of methylene blue than bulk ZnNb2O6

  14. High Surface Area of Nano Pores Activated Carbon Derived From Agriculture Waste

    International Nuclear Information System (INIS)

    In this study, the high surface area of nano pores activated carbon rice husk originated from local biomass was investigated. The comparison in terms of surface area, porosity and behavior in electrochemical analysis with commercial activated carbon was studied in details. The nano pores activated carbon rice husk was synthesis using consecutive of carbonization and activation under purified nitrogen and carbon dioxide purge. Interestingly, the surface area and capacity of the nano pores activated carbon rice indicated higher in comparison to commercial activated carbon. This indicated that the nano pores activated carbon has potential to be developed further as an alternative material in reducing suspension on commercial activated carbon. (author)

  15. 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

    2016-05-01

    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.

  16. Modulation of T-bet and Eomes during Maturation of Peripheral Blood NK Cells Does Not Depend on Licensing/Educating KIR.

    Science.gov (United States)

    Pradier, Amandine; Simonetta, Federico; Waldvogel, Sophie; Bosshard, Carine; Tiercy, Jean-Marie; Roosnek, Eddy

    2016-01-01

    Peripheral natural killer (NK) cells upregulate T-bet and downregulate Eomes, the key transcription factors regulating NK cell maturation and function during the last maturation steps toward terminally differentiated effector cells. During this process, NK cells acquire killer immunoglobulin-like receptors (KIR) and effector functions, such as cytotoxicity and target cell-induced cytokine production. Inhibitory KIR are pivotal in the control of effector functions, but whether they also modulate T-bet/Eomes expression is unknown. We have measured T-bet/Eomes levels, KIR expression, and effector functions of maturing CD94(neg)CD56(dim)NK cells using CD57 as surface marker for maturation. Our cohort consisted of 23 healthy blood donors (HBD) homozygous for the KIR A haplotype that contains only inhibitory KIR2DL1 (ligand HLA-C2), KIR2DL3 (ligand HLA-C1), and KIR3DL1 (ligand HLA-Bw4). We confirm that during maturation of NK cells, the number of KIR increases, levels of T-bet/Eomes are modulated, and that cells acquire effector functions, such as cytotoxicity (CD107) and target cell-induced cytokine production (TNF-α). Because maturation was associated with the increase of the number of KIR as well as with the modulation of T-bet/Eomes, the number of KIR correlated with the extent of T-bet/Eomes modulation. However, whether the KIR were triggered by their cognate HLA ligands or not had no impact on T-bet and Eomes expression, indicating that modulation of T-box transcription factors during NK cell maturation does not depend on signals conveyed by KIR. We discuss the relevance of this finding in the context of models of NK cell maturation while cautioning that results obtained in a perhaps quite heterogeneous cohort of HBD are not necessarily conclusive. PMID:27605928

  17. 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.

  18. 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

  19. Ion exchange capacities and surface areas of some major components and common fracture filling materials of igneous rocks

    International Nuclear Information System (INIS)

    Surface/mass ratios have been determined by the ethylene glycol method and the BET-method, and an- and cation exchange capacities vs pH have been measured by an isotopic dilution technique for some 30-35 pure minerals. These minerals, which are representative of major components and common accessory minerals, including fracture minerals, of crystalline rocks, have also been used in radionuclide sorption studies within the Swedish waste program. Generally, the anion exchange capacities are low (< 1 meq/kg) for all the minerals. The cation exchange capacities, which increase with pH, are < 1 meq/kg for the non-silicates with few exceptions, 1-10 meq/kg for most of the silicates except the phyllosilicates and ranging from 10 up to 800 meq/kg for clay minerals (e.g. montmorillonite) and some of the zeolites (e.g. stilbite). (authors)

  20. 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.

  1. 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.

  2. 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....

  3. Estimation of Surface Area and Volume of a Nematode from Morphometric Data

    OpenAIRE

    Simon Brown; Kevin C. Pedley; David C. SIMCOCK

    2016-01-01

    Nematode volume and surface area are usually based on the inappropriate assumption that the animal is cylindrical. While nematodes are approximately circular in cross section, the radius varies longitudinally. We use standard morphometric data to obtain improved estimates of volume and surface area based on (i) a geometrical approach and (ii) a Bézier representation of the nematode. These new estimators require only the morphometric data available from Cobb’s ratios, but if fewer coordinates ...

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

    Science.gov (United States)

    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.

  5. Age Differences in Prefrontal Surface Area and Thickness in Middle Aged to Older Adults

    OpenAIRE

    Dotson, Vonetta M.; Sarah M. Szymkowicz; Sozda, Christopher N.; Kirton, Joshua W.; Green, Mackenzie L.; O’Shea, Andrew; McLaren, Molly E.; Anton, Stephen D.; Manini, Todd M; Woods, Adam J.

    2016-01-01

    Age is associated with reductions in surface area and cortical thickness, particularly in prefrontal regions. There is also evidence of greater thickness in some regions at older ages. Non-linear age effects in some studies suggest that age may continue to impact brain structure in later decades of life, but relatively few studies have examined the impact of age on brain structure within middle-aged to older adults. We investigated age differences in prefrontal surface area and cortical thick...

  6. Novel fabrication technology for three-dimensional high surface area pyrolized structures

    Science.gov (United States)

    Ho, Vinh; Shimada, Mark; Szeto, David; Mukherjee, Partha P.; Kang, Qinjun; Kulinsky, Lawrence; Madou, Marc J.

    2010-04-01

    High specific surface area structures are used in a variety of applications including production of highly sensitive biosensors, fabrication of separation membranes, manufacturing of high throughput catalytic microreactors, and development of efficient electrodes for batteries and fuel cells. In many electrochemical applications (i.e. sensors and batteries) it's also critical to have good conductive properties of the fabricated high surface area structures. For energy harvesting technologies such as batteries and fuel cells, careful design of surface-to-volume ratio of the electrode surface is important, because while high specific surface area facilitates electrochemical reaction rates, it also increases overall electrode resistance. Thus, it is desirable to construct electrodes with a range of hierarchical features (for example with fractal structures). We invented a novel fabrication technology for creating three-dimensional conductive high surface area structures based on the deposition and subsequent processing of the electroactive polymers (EAP). The proposed fabrication technique is capable of fast and inexpensive production of high surface area structures with the designed geometry, porosity, and conductivity.

  7. Assessment of nanoparticle surface area by measuring unattached fraction of radon progeny

    Energy Technology Data Exchange (ETDEWEB)

    Ruzer, Lev S. [Ernest Orlando Lawrence Berkeley National Laboratory, Indoor Environment Department (United States)], E-mail: LSRuzer@lbl.gov

    2008-05-15

    A number of studies on the exposure of nanometer aerosols have indicated that health effects associated with low-solubility inhaled particles in the range of 1-100 nm may be more appropriately associated with particulate surface area than mass concentration. Such data on correlation between number, surface area and mass concentration are needed for exposure investigations, but the means for measuring aerosol surface area are not readily available. In this paper we propose a method for particle surface area assessment based on a new approach, deposition of the 'unattached fraction of radon progeny' onto nanometer aerosols.The proposed approach represents a synthesis of:(1) Derived direct analytical correlation between the 'unattached fraction' of radon progeny and surface area particle concentration in the range of 1-100 nm particle diameter;(2) Experimental data on correlation between the unattached fraction of radon progeny and particle surface area for particles with diameter in the range of 44 nm-2.1 {mu}m.

  8. KOH活化法高比表面积竹质活性炭的制备与表征%Preparation and characterization of high specific surface area activated carbon from bamboo by chemical activation with KOH

    Institute of Scientific and Technical Information of China (English)

    王秀芳; 张会平; 陈焕钦

    2006-01-01

    以竹屑为原料,研究了KOH活化法高比表面积活性炭的制备工艺.分别考察了浸渍比、活化温度、活化时间等工艺参数对产品吸附性能的影响,并提出了可能的活化机理.在所研究的实验条件下,最佳的制备工艺是浸渍比1.0,活化温度800℃,活化时间2h.所得到的活性炭产品的比表面积和孔容可达2996m2/g和1.64cm3/g.该产品附加值高,在吸附领域特别是在双电层电容器的电极材料领域有广阔的应用前景.%High specific surface area activated carbon was prepared from bamboo by chemical activation with KOH. The influence of activation parameters on the final products was investigated by varying the KOH/bamboo ratio, activation temperature and hold time. The samples were characterized by nitrogen adsorption isotherms at 77K. The specific surface area and pore volume of activated carbon were calculated by BET and t-plot method. The possible activation mechanism was also proposed. Under the experimental conditions, the optimum conditions for preparing high specific surface area activated carbon are at a KOH/precursor ratio of 1.0, an activation temperature of 800℃ and a hold time of 2h. With these experimental conditions, an activated carbon with a BET surface area of 2996m2/g and a total pore volume of 1.64cm3/g was produced. The product is a novel material for adsorption and for the application in electric double-layer capacitors.

  9. 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...

  10. 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.)

  11. Betting in the Shadow of Match-Fixing

    OpenAIRE

    Parimal Kanti Bag; Bibhas Saha

    2010-01-01

    Two bookmakers compete in Bertrand fashion while setting odds on the outcomes of a sporting contest where an influential punter (or betting syndicate) may bribe some player(s) to fix the contest. Zero profit and bribe prevention may not always hold together. When the influential punter is quite powerful, the bookies may coordinate on prices and earn positive profits for fear of letting the `lemons' (i.e., the influential punter) in. On the other hand, sometimes the bookies make zero profits b...

  12. 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.

  13. Application of stereological methods to estimate post-mortem brain surface area using 3T MRI

    DEFF Research Database (Denmark)

    Furlong, Carolyn; García-Fiñana, Marta; Puddephat, Michael;

    2013-01-01

    The Cavalieri and Vertical Sections methods of design based stereology were applied in combination with 3 tesla (i.e. 3T) Magnetic Resonance Imaging (MRI) to estimate cortical and subcortical volume, area of the pial surface, area of the grey-white matter boundary, and thickness of the cerebral...

  14. Determination of surface-accessible acidic hydroxyls and surface area of lignin by cationic dye adsorption

    OpenAIRE

    Sipponen, Mika Henrikki; Pihlajaniemi, Ville; Littunen, Kuisma; Pastinen, Ossi; Laakso, Simo

    2014-01-01

    A new colorimetric method for determining the surface-accessible acidic lignin hydroxyl groups in lignocellulose solid fractions was developed. The method is based on selective adsorption of Azure B, a basic dye, onto acidic hydroxyl groups of lignin. Selectivity of adsorption of Azure B on lignin was demonstrated using lignin and cellulose materials as adsorbents. Adsorption isotherms of Azure B on wheat straw (WS), sugarcane bagasse (SGB), oat husk, and isolated lignin materials were determ...

  15. 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.

  16. Euclidean Wilson loops and minimal area surfaces in lorentzian AdS 3

    Science.gov (United States)

    Irrgang, Andrew; Kruczenski, Martin

    2015-12-01

    The AdS/CFT correspondence relates Wilson loops in N=4 SYM theory to minimal area surfaces in AdS 5 × S 5 space. If the Wilson loop is Euclidean and confined to a plane ( t, x) then the dual surface is Euclidean and lives in Lorentzian AdS 3 ⊂ AdS 5. 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 Schrödinger equation has all its solutions anti-periodic. If the potential for that Schrödinger 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.

  17. 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.

  18. 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.

  19. 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 energy resolution was 10.8% and 3.3% for LSO and LaBr3 respectively and the coincidence window was set at 2 ns. The brain was simulated as a sphere of uniform F-18 activity with diameter of 10 cm embedded in a center of water sphere with diameter of 10 cm. Results: Analytical and Monte Carlo models showed similar results for lower energy window values (458 keV versus 445 keV for LSO, and 492 keV versus 485 keV for LaBr3), and for the relative performance of system sensitivity. Monte Carlo results further showed that the BET geometry had >50% better noise equivalent count (NEC) performance relative to the CYL geometry, and >1100% better performance than a WB

  20. 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

  1. Study of measurement methods of ultrafine aerosols surface-area for characterizing occupational exposure

    International Nuclear Information System (INIS)

    This work aims at improving knowledge on ultrafine aerosols surface-area measurement. Indeed, the development of nano-technologies may lead to occupational exposure to airborne nano-structured particles, which involves a new prevention issue. There is currently no consensus concerning what parameter (mass, surface-area, number) should be measured. However, surface-area could be a relevant metric, since it leads to a satisfying correlation with biological effects when nano-structured particles are inhaled. Hence, an original theoretical work was performed to position the parameter of surface-area in relation to other aerosol characteristics. To investigate measurement techniques of nano-structured aerosols surface-area, the experimental facility CAIMAN (Characterization of Instruments for the Measurement of Aerosols of Nano-particles) was designed and built. Within CAIMAN, it is possible to produce nano-structured aerosols with varying and controlled properties (size, concentration, chemical nature, morphology, state-of-charge), stable and reproducible in time. The generated aerosols were used to experimentally characterize the response of the instruments in study (NSAM and AeroTrak 9000 TSI, LQ1-DC Matter Engineering). The response functions measured with monodisperse aerosols show a good agreement with the corresponding theoretical curves in a large size range, from 15 to 520 nm. Furthermore, hypotheses have been formulated to explain the reasonable biases observed when measuring poly-disperse aerosols. (author)

  2. Scalable surface area characterization by electrokinetic analysis of complex anion adsorption.

    Science.gov (United States)

    Hanaor, Dorian A H; Ghadiri, Maliheh; Chrzanowski, Wojciech; Gan, Yixiang

    2014-12-23

    By means of the in situ electrokinetic assessment of aqueous particles in conjunction with the addition of anionic adsorbates, we develop and examine a new approach to the scalable characterization of the specific accessible surface area of particles in water. For alumina powders of differing morphology in mildly acidic aqueous suspensions, the effective surface charge was modified by carboxylate anion adsorption through the incremental addition of oxalic and citric acids. The observed zeta potential variation as a function of the proportional reagent additive was found to exhibit inverse hyperbolic sine-type behavior predicted to arise from monolayer adsorption following the Grahame-Langmuir model. Through parameter optimization by inverse problem solving, the zeta potential shift with relative adsorbate addition revealed a nearly linear correlation of a defined surface-area-dependent parameter with the conventionally measured surface area values of the powders, demonstrating that the proposed analytical framework is applicable for the in situ surface area characterization of aqueous particulate matter. The investigated methods have advantages over some conventional surface analysis techniques owing to their direct applicability in aqueous environments at ambient temperature and the ability to modify analysis scales by variation of the adsorption cross section. PMID:25495551

  3. 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.

  4. Sea surface temperature and torrential rains in the Valencia region: modelling the role of recharge areas

    Science.gov (United States)

    Pastor, Francisco J.

    2016-04-01

    Heavy rain events are frequently recorded in the Western Mediterranean causing economic and human losses. A main factor in the development of torrential rains is ocean-atmosphere exchange of heat and moisture that can destabilize air masses travelling over the sea. The study of air mass trajectories previous to the rain event permits the identification of sea areas that could probably contribute to the development or intensification of rainfall. From a Mediterranean sea surface temperature climatology, its spatio-temporal distribution patterns have been studied showing two main distribution modes in winter and summer and transitional regimes in spring and autumn. Hence, three heavy precipitation events, for such winter and summer sea temperature regimes and for fall transition, affecting the Valencia region have been selected to study the effect of sea surface temperature in torrential rains. Simulations with perturbed sea surface temperature in different areas along the air mass path were run to compare results with unperturbed simulation. The variation of sea surface temperature in certain areas caused significant changes in model accumulated values and its spatial distribution. Therefore, the existence of areas that at a greater extent favour air-sea interaction leading to the development of torrential rainfall in the Valencia region is shown. This methodology could be extended to other Mediterranean regions to look for such potential recharge areas. The identification of sea areas that contribute to the development or intensification of heavy rain events in the Mediterranean countries could be a useful prognosis and/or monitoring tool.

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

    DEFF Research Database (Denmark)

    Charalampidis, C.; Van As, D.; Box, J. E.;

    2015-01-01

    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......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.......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...

  6. Sensitivity of human lung adenocarcinoma cell lines to targeted inhibition of BET epigenetic signaling proteins

    OpenAIRE

    Lockwood, William W; Zejnullahu, Kreshnik; James E Bradner; Varmus, Harold

    2012-01-01

    Bromodomain and extra terminal domain (BET) proteins function as epigenetic signaling factors that associate with acetylated histones and facilitate transcription of target genes. Inhibitors targeting the activity of BET proteins have shown potent antiproliferative effects in hematological cancers through the suppression of c-MYC and downstream target genes. However, as the epigenetic landscape of a cell varies drastically depending on lineage, transcriptional coactivators such as BETs would ...

  7. 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.

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

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

    Zauzi, N. S. Ahmad; M. Z. H. Zakaria; Baini, R.; Rahman, M. R.; N. Mohamed Sutan; Hamdan, S

    2016-01-01

    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, precipita...

  10. 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.

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

    International Nuclear Information System (INIS)

    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

  12. 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

  13. Hierarchical Porous and High Surface Area Tubular Carbon as Dye Adsorbent and Capacitor Electrode.

    Science.gov (United States)

    Chen, Long; Ji, Tuo; Brisbin, Logan; Zhu, Jiahua

    2015-06-10

    Hierarchically porous tubular carbon (HPTC) with large surface area of 1094 m(2)/g has been successfully synthesized by selectively removing lignin from natural wood. No templates or chemicals are involved during the process. By further KOH activation, surface area of activated HPTC reaches up to 2925 m(2)/g. These materials show unprecedented high adsorption capacity toward organic dyes (methylene blue, 838 mg/g; methyl orange, 264 mg/g) and large electrochemical capacitance of >200 F/g. The sustainable feature of the wood precursor and demonstrated superior adsorption and energy storage properties allow promising applications of the processed materials in energy and environmental related fields. PMID:25980528

  14. A Template-Free, Ultra-Adsorbing, High Surface Area Carbonate Nanostructure

    OpenAIRE

    Johan Forsgren; Sara Frykstrand; Kathryn Grandfield; Albert Mihranyan; Maria Strømme

    2013-01-01

    We report the template-free, low-temperature synthesis of a stable, amorphous, and anhydrous magnesium carbonate nanostructure with pore sizes below 6 nm and a specific surface area of ∼ 800 m(2) g(-1), substantially surpassing the surface area of all previously described alkali earth metal carbonates. The moisture sorption of the novel nanostructure is featured by a unique set of properties including an adsorption capacity ∼50% larger than that of the hygroscopic zeolite-Y at low relative hu...

  15. Estimation of Surface Area and Volume of a Nematode from Morphometric Data

    Directory of Open Access Journals (Sweden)

    Simon Brown

    2016-01-01

    Full Text Available Nematode volume and surface area are usually based on the inappropriate assumption that the animal is cylindrical. While nematodes are approximately circular in cross section, the radius varies longitudinally. We use standard morphometric data to obtain improved estimates of volume and surface area based on (i a geometrical approach and (ii a Bézier representation of the nematode. These new estimators require only the morphometric data available from Cobb’s ratios, but if fewer coordinates are available the geometric approach reduces to the standard estimates. Consequently, these new estimators are better than the standard alternatives.

  16. Investigation of Aerosol Surface Area Estimation from Number and Mass Concentration Measurements: Particle Density Effect

    Science.gov (United States)

    Ku, Bon Ki; Evans, Douglas E.

    2015-01-01

    For nanoparticles with nonspherical morphologies, e.g., open agglomerates or fibrous particles, it is expected that the actual density of agglomerates may be significantly different from the bulk material density. It is further expected that using the material density may upset the relationship between surface area and mass when a method for estimating aerosol surface area from number and mass concentrations (referred to as “Maynard’s estimation method”) is used. Therefore, it is necessary to quantitatively investigate how much the Maynard’s estimation method depends on particle morphology and density. In this study, aerosol surface area estimated from number and mass concentration measurements was evaluated and compared with values from two reference methods: a method proposed by Lall and Friedlander for agglomerates and a mobility based method for compact nonspherical particles using well-defined polydisperse aerosols with known particle densities. Polydisperse silver aerosol particles were generated by an aerosol generation facility. Generated aerosols had a range of morphologies, count median diameters (CMD) between 25 and 50 nm, and geometric standard deviations (GSD) between 1.5 and 1.8. The surface area estimates from number and mass concentration measurements correlated well with the two reference values when gravimetric mass was used. The aerosol surface area estimates from the Maynard’s estimation method were comparable to the reference method for all particle morphologies within the surface area ratios of 3.31 and 0.19 for assumed GSDs 1.5 and 1.8, respectively, when the bulk material density of silver was used. The difference between the Maynard’s estimation method and surface area measured by the reference method for fractal-like agglomerates decreased from 79% to 23% when the measured effective particle density was used, while the difference for nearly spherical particles decreased from 30% to 24%. The results indicate that the use of

  17. 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.

  18. 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.

  19. Scalable syntheses of the BET bromodomain inhibitor JQ1

    Science.gov (United States)

    Syeda, Shameem Sultana; Jakkaraj, Sudhakar; Georg, Gunda I.

    2015-01-01

    We have developed methods involving the use of alternate, safer reagents for the scalable syntheses of the potent BET bromodomain inhibitor JQ1. A one-pot three step method, involving the conversion of a benzodiazepine to a thioamde using Lawesson’s reagent, followed by amidrazone formation and installation of the triazole moiety furnished JQ1. This method provides good yields and a facile purification process. For the synthesis of enantiomerically enriched (+)-JQ1, the highly toxic reagent diethyl chlorophosphate, used in a previous synthesis, was replaced with the safer reagent diphenyl chlorophosphate in the three-step one-pot triazole formation without effecting yields and enantiomeric purity of (+)-JQ1. PMID:26034331

  20. Power-law distribution in Japanese racetrack betting

    CERN Document Server

    Ichinomiya, T

    2006-01-01

    Gambling is one of the basic economic activities that humans indulge in. An investigation of gambling activities provides deep insights into the economic actions of people and sheds lights on the study of econophysics. In this paper we present an analysis of the distribution of the final odds of the races organized by the Japan Racing Association. The distribution of the final odds $P_o(x)$ indicates a clear power law $P_o(x)\\propto 1/x$, where $x$ represents the final odds. This power law can be explained on the basis of the assumption that that every bettor bets his money on the horse that appears to be the strongest in a race.

  1. Roles of surface water areas for water and solute cycle in Hanoi city, Viet Nam

    Science.gov (United States)

    Hayashi, Takeshi; Kuroda, Keisuke; Do Thuan, An; Tran Thi Viet, Nga; Takizawa, Satoshi

    2013-04-01

    Hanoi city, the capital of Viet Nam, has developed beside the Red river. Recent rapid urbanization of this city has reduced a large number of natural water areas such as lakes, ponds and canals not only in the central area but the suburban area. Contrary, the urbanization has increased artificial water areas such as pond for fish cultivation and landscaping. On the other hand, the urbanization has induced the inflow of waste water from households and various kinds of factories to these water areas because of delay of sewerage system development. Inflow of the waste water has induced eutrophication and pollution of these water areas. Also, there is a possibility of groundwater pollution by infiltration of polluted surface water. However, the role of these water areas for water cycle and solute transport is not clarified. Therefore, this study focuses on the interaction between surface water areas and groundwater in Hanoi city to evaluate appropriate land development and groundwater resource management. We are carrying out three approaches: a) understanding of geochemical characteristics of surface water and groundwater, b) monitoring of water levels of pond and groundwater, c) sampling of soil and pond sediment. Correlation between d18O and dD of precipitation (after GNIP), the Red River (after GNIR) and the water samples of this study showed that the groundwater is composed of precipitation, the Red River and surface water that has evaporation process. Contribution of the surface water with evaporation process was widely found in the study area. As for groundwater monitoring, the Holocene aquifers at two sites were in unconfined condition in dry season and the groundwater levels in the aquifer continued to increase through rainy season. The results of isotopic analysis and groundwater level monitoring showed that the surface water areas are one of the major groundwater sources. On the other hand, concentrations of dissolved Arsenic (filtered by 0.45um) in the pore

  2. Surface area of early visual cortex predicts individual speed of traveling waves during binocular rivalry.

    Science.gov (United States)

    Genç, Erhan; Bergmann, Johanna; Singer, Wolf; Kohler, Axel

    2015-06-01

    Binocular rivalry ensues when different images are presented to the 2 eyes with conscious perception alternating between the possible interpretations. For large rivalry displays, perceptual transitions are initiated at one location and spread to other parts of the visual field, a phenomenon termed "traveling wave." Previous studies investigated the underlying neural mechanisms of the traveling wave and surmised that primary visual cortex might play an important role. We used magnetic resonance imaging and behavioral measures in humans to explore how interindividual differences in observers' subjective experience of the wave are related to anatomical characteristics of cortical regions. We measured wave speed in participants and confirmed the long-term stability of the individual values. Retinotopic mapping was employed to delineate borders of visual areas V1-V3 in order to determine surface area and cortical thickness in those regions. Only the surface areas of V1 and V2, but not V3 showed a correlation with wave speed. For individuals with larger V1/V2 area, the traveling wave needed longer to spread across the same distance in visual space. Our results highlight the role of early visual areas in mediating binocular rivalry and suggest possible mechanisms for the correlation between surface area and the traveling waves. PMID:24334918

  3. 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.

  4. Generation of large-area and glow-like surface discharge in atmospheric pressure air

    Science.gov (United States)

    Song, Ying; Xia, Yang; Bi, Zhenhua; Wang, Xueyang; Qi, Zhihua; Ji, Longfei; Li, Bin; Liu, Dongping

    2016-08-01

    A large-area (6 cm × 6 cm) air surface dielectric barrier discharge has been generated at atmospheric pressure by using well-aligned and micron-sized dielectric tubes with tungsten wire electrodes. Intensified CCD images with an exposure time of 5 ns show that the uniform surface air discharge can be generated during the rising and falling time of pulsed DC voltage. Current and voltage and optical measurements confirm the formation of glow-like air discharges on the surface of micron-sized dielectric tubes. Simulation results indicate that the microelectrode configuration contributes to the formation of strong surface electric field and plays an important role in the generation of uniform surface air discharge.

  5. The role of body surface area in quantity discrimination in angelfish (Pterophyllum scalare).

    Science.gov (United States)

    Gómez-Laplaza, Luis M; Gerlai, Robert

    2013-01-01

    Although some fish species have been shown to be able to discriminate between two groups (shoals) of conspecifics differing in the number of members, most studies have not controlled for continuous variables that covary with number. Previously, using angelfish (Pterophyllum scalare) we started the systematic analysis of the potential influence of such continuous variables, and found that they play different roles in shoal discrimination depending on whether large (≥ 4 fish) or small (<4 fish) shoals were contrasted. Here, we examine the potential role of the overall body surface area of stimulus fish in shoal preference, a prominent variable not yet examined in angelfish. We report that both when numerically large (5 versus 10 fish) and when small (2 versus 3 fish) shoals were contrasted, angelfish were unable to discriminate the numerically different shoals as long as the surface area of the contrasted shoals was equated. Thus, we conclude that body surface may be an important continuous variable in shoal discrimination. This conclusion was further supported by the analysis of preference when shoals of the same numerical size but different body surface area were contrasted. We found subjects to spend significantly more time close to the shoals with the greater overall surface area. Last, we conducted an experiment in which we simultaneously controlled a set of continuous variables, including overall surface area, and found angelfish to use the number of shoal members as a cue only in large shoal contrasts but not in small shoal contrasts. This result suggests the potential existence of different processing systems for large and small numbers in fish. PMID:24386299

  6. The role of body surface area in quantity discrimination in angelfish (Pterophyllum scalare.

    Directory of Open Access Journals (Sweden)

    Luis M Gómez-Laplaza

    Full Text Available Although some fish species have been shown to be able to discriminate between two groups (shoals of conspecifics differing in the number of members, most studies have not controlled for continuous variables that covary with number. Previously, using angelfish (Pterophyllum scalare we started the systematic analysis of the potential influence of such continuous variables, and found that they play different roles in shoal discrimination depending on whether large (≥ 4 fish or small (<4 fish shoals were contrasted. Here, we examine the potential role of the overall body surface area of stimulus fish in shoal preference, a prominent variable not yet examined in angelfish. We report that both when numerically large (5 versus 10 fish and when small (2 versus 3 fish shoals were contrasted, angelfish were unable to discriminate the numerically different shoals as long as the surface area of the contrasted shoals was equated. Thus, we conclude that body surface may be an important continuous variable in shoal discrimination. This conclusion was further supported by the analysis of preference when shoals of the same numerical size but different body surface area were contrasted. We found subjects to spend significantly more time close to the shoals with the greater overall surface area. Last, we conducted an experiment in which we simultaneously controlled a set of continuous variables, including overall surface area, and found angelfish to use the number of shoal members as a cue only in large shoal contrasts but not in small shoal contrasts. This result suggests the potential existence of different processing systems for large and small numbers in fish.

  7. A MATHEMATICAL ANALYSIS OF THE INCLUSION OF INSTITUTIONAL BETTING FUNDS INTO STOCK MARKET: THE CASE OF TECHNICAL AND FUNDAMENTAL PAYOFF MODELS IN HORSERACE BETTING

    Directory of Open Access Journals (Sweden)

    Craig George Leslie Hopf

    2014-01-01

    Full Text Available Horserace win and place returns have yet to be considered seriously as portfolio inputs in financial trading markets. However there exist technical and fundamental stochastic models of parametric and nonparametric distribution that appear to optimize expected returns from win and place investing in the horserace wagering market. In this study, a complex number optimization technique is introduced and applied to develop a deterministic betting model that calculates actual returns from the win and place betting. Using classes of models mentioned, field win bet payoff results were generated for a sample of successive global galloper races from Australasia, Asia and the United Kingdom. It was noted double digit returns exceeding 10% were consistently achieved within minutes of horserace investing, with arbitrage opportunity locked into prerace from the deterministic model. The results from this study provide evidence for serious investigation into the inclusion and benefit of Institutional Betting Funds into the local stock market.

  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. Measurement of Friction Noise Versus Contact Area of Rough Surfaces Weakly Loaded

    OpenAIRE

    Le Bot, Alain; Bou-Chakra, Elie

    2010-01-01

    This study presents an experiment to measure the dependence of friction noise versus the nominal contact area. The friction-induced vibration is generated by the sliding of two rough surfaces. The normal load is low leading to a weak contact. The normal load and the sliding velocity are maintained constant. The nominal contact area ranges over two orders of magnitude. It is found that two regimes exist. On the one hand, the vibration energy is proportional to the contact area. But on the seco...

  10. 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.

  11. Contributions of increased agricultural abandonment area to recent surface warming trend in Shikoku Island, Japan

    Science.gov (United States)

    Yoshida, R.; Nishimori, M.; Iizumi, T.; Osawa, T.

    2012-04-01

    A remarkable increasing trend in abandoned cropland has already been observed in hilly and mountainous areas, Japan. Changes to abandoned areas from cropland (typically, paddy fields) could have impacts on surface air temperatures and their trends. We evaluated contributions of land surface change, specifically, the recently reported increases in abandoned cropland on daily maximum, mean, and minimum temperature with Shikoku Island, Japan where croplands have been significantly decreasing taken as an example. Land use change was expressed by the modifications of physical land surface parameters, i.e., surface albedo, evaporative efficiency, roughness length, heat capacity, and thermal conductivity. The sensitivity of the air temperatures to each land surface parameter was then derived from the numerical experiments using three-dimensional regional atmospheric model (JMA-NHM) and artificially modified land surface conditions. An accurate estimation of the contributions is expected as the JMA-NHM model allows us to consider three-dimensional land-atmosphere interactions that are impossible for one-dimensional land surface model alone. We set the five land surface parameters and calculated a sensitivity of temperatures in regard to each land surface parameter change for the periods of 15th June to 15th August 1985, 1990, 1995, 2000, and 2005 when cropland area are presented in Japan. The experiment result showed that surface albedo and evaporative efficiency had significant sensitivity on the daily maximum and mean temperatures whereas heat capacity and thermal conductivity were impactful on the daily minimum temperature. Roughness length was less impactful for any temperatures. Parameter sensitivity showed geographical distribution, such as significant impact in inland area rather than coastal area for the response of daily mean temperature by surface albedo and evaporative efficiency changes. Lower sensitivity in coastal area was attributed to thermal advection from

  12. 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.

  13. 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

  14. 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....

  15. 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.

  16. 3D-Microalgae software used for the estimation of microalgae biovolumes and surface area

    Directory of Open Access Journals (Sweden)

    Anton M. Lyakh

    2012-03-01

    Full Text Available The main steps of using of an original software package 3D-Microalgae for constructing three-dimensional geometric models of microalgae shells and estimating of their biovolume and surface areas are described. An improved method realized in the software allows significantly increasing the accuracy of that morphometrical characteristics calculation

  17. 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.

  18. 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 ammoniu...

  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. 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...

  1. Periodic Mesoporous Organosilica Nanocubes with Ultrahigh Surface Areas for Efficient CO2 Adsorption

    Science.gov (United States)

    Wei, Yong; Li, Xiaomin; Zhang, Renyuan; Liu, Yong; Wang, Wenxing; Ling, Yun; El-Toni, Ahmed Mohamed; Zhao, Dongyuan

    2016-02-01

    Ultrahigh surface area single-crystals of periodic mesoporous organosilica (PMOs) with uniform cubic or truncated-cubic morphology and organic/inorganic components homogeneously distributed over the whole frameworks have successfully been prepared by a sol-gel surfactant-templating method. By tuning the porous feature and polymerization degree, the surface areas of the obtained PMO nanocubes can reach as high as 2370 m2/g, which is the highest for silica-based mesoporous materials. The ultrahigh surface area of the obtained PMO single crystals is mainly resulted from abundant micropores in the mesoporous frameworks. Furthermore, the diameter of the nanocubes can also be well controlled from 150 to 600 nm. The materials show ultrahigh CO2 adsorption capacity (up to 1.42 mmol/g at 273 K) which is much higher than other porous silica materials and comparable to some carbonaceous materials. The adsorption of CO2 into the PMO nanocubes is mainly in physical interaction, therefore the adsorption-desorption process is highly reversible and the adsorption capacity is much dependent on the surface area of the materials. Moreover, the selectivity is also very high (~11 times to N2) towards CO2 adsorption.

  2. Periodic Mesoporous Organosilica Nanocubes with Ultrahigh Surface Areas for Efficient CO₂ Adsorption.

    Science.gov (United States)

    Wei, Yong; Li, Xiaomin; Zhang, Renyuan; Liu, Yong; Wang, Wenxing; Ling, Yun; El-Toni, Ahmed Mohamed; Zhao, Dongyuan

    2016-01-01

    Ultrahigh surface area single-crystals of periodic mesoporous organosilica (PMOs) with uniform cubic or truncated-cubic morphology and organic/inorganic components homogeneously distributed over the whole frameworks have successfully been prepared by a sol-gel surfactant-templating method. By tuning the porous feature and polymerization degree, the surface areas of the obtained PMO nanocubes can reach as high as 2370 m(2)/g, which is the highest for silica-based mesoporous materials. The ultrahigh surface area of the obtained PMO single crystals is mainly resulted from abundant micropores in the mesoporous frameworks. Furthermore, the diameter of the nanocubes can also be well controlled from 150 to 600 nm. The materials show ultrahigh CO2 adsorption capacity (up to 1.42 mmol/g at 273 K) which is much higher than other porous silica materials and comparable to some carbonaceous materials. The adsorption of CO2 into the PMO nanocubes is mainly in physical interaction, therefore the adsorption-desorption process is highly reversible and the adsorption capacity is much dependent on the surface area of the materials. Moreover, the selectivity is also very high (~11 times to N2) towards CO2 adsorption. PMID:26868049

  3. 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...

  4. 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...

  5. Proportional Reasoning Ability and Concepts of Scale: Surface Area to Volume Relationships in Science

    Science.gov (United States)

    Taylor, Amy; Jones, Gail

    2009-01-01

    The "National Science Education Standards" emphasise teaching unifying concepts and processes such as basic functions of living organisms, the living environment, and scale. Scale influences science processes and phenomena across the domains. One of the big ideas of scale is that of surface area to volume. This study explored whether or not there…

  6. Specific surface area behavior of a dissolving population of particles. Augmenting Mercer Dissolution Theory

    International Nuclear Information System (INIS)

    Specific surface area (Sp) measurements were made on two uranium oxide aerosol materials before and after in vitro dissolution studies were performed on the materials. The results of these Sp measurements were evaluated relative to predictions made from extending Mercer dissolution theory to describe the Sp behavior of a dissolving population of particles

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

    DEFF Research Database (Denmark)

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

    . 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...

  8. 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

  9. 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.

  10. 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...

  11. The Soil Characteristic Curve at Low Water Contents: Relations to Specific Surface Area and Texture

    DEFF Research Database (Denmark)

    Resurreccion, Augustus; Møldrup, Per; Schjønning, Per;

    Accurate description of the soil-water retention curve (SWRC) at low water contents is important for simulating water dynamics, plant-water relations, and microbial processes in surface soil. Soil-water retention at soil-water matric potential of less than -10 MPa, where adsorptive forces dominate...... of surface area estimates and the Dexter index n was observed and applied as an additional scaling function in the TO model to rescale the soil-water retention curve at low water contents across soil textural classes. However, the TO model still overestimated the water film thickness at potentials...... between CRN model slope (1/B) and SA and CL. We, therefore, recommend to use the empirical CRN model for predicting the dry part of the water retention curve (-10 to -800 MPa) from measured soil texture or surface area and, in perspective, to modify the more conceptual TO model to obtain better...

  12. 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.

  13. 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.

  14. 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.

  15. Comprehensive cortical thickness and surface area comparison between young Uyghur and Han Chinese cohorts.

    Science.gov (United States)

    Lu, Jun; Jiang, Chunhui; Wang, Jian; Jia, Wenxiao

    2016-10-01

    We hypothesized that the brain structural differences as discovered previously between Westerners and East Asians could also be revealed between Han Chinese and Uyghur, which were genetically related ethnic groups with distinct languages. We conducted a brain MRI structural comparison in terms of cortical thickness and surface area between 15 healthy young Uyghurs and 15 age-matched Han Chinese. Widespread regions with significantly greater cortical thickness were found in the Uyghurs, and their distribution showed strong resemblance to previous "Westerners vs. Asians" findings. While surface area analysis displayed less widespread brain differences. Notably, our detected regions with structural differences contained a large part of language-specific or at least closely language-related brain areas, which may partly be attributable to the brain plasticity respectively driven by Uyghur and Mandarin. Our findings will help to better understand the neurobiological basis of interethnic differences along with the language processing mechanisms of Han Chinese and Uyghur. PMID:27067474

  16. Interrelationships among plant biomass, plant surface area and the interception of particulate deposition by grasses

    International Nuclear Information System (INIS)

    The interrelationships among plant biomass, plant surface area and interception fraction were determined for the interception by corn of 238Pu-bearing particles released to the atmosphere from the H-Area nuclear fuels chemical separations facility on the U.S. Department of Energy's Savannah River Plant in Barnwell County, South Carolina. The relationship between interception fraction and corn biomass was accurately approximated by a filtration model with an absorption coefficient of 3.60 m2 kg-1. A filtration model with an absorption coefficient of 2.91 m2 kg-1 accurately approximated the relationship between biomass and interception fraction for data compiled from the literature for a variety of grass species. A linear regression model accurately approximated the relationship between interception fraction and surface area, but was not a better predictor of interception fraction than the filtration model for biomass

  17. 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.

  18. 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

  19. 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

  20. 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. PMID:19368232

  1. Geology and surface geochemistry of the Roosevelt Springs Known Geothermal Resource Area, Utah

    Energy Technology Data Exchange (ETDEWEB)

    Lovell, J.S.; Meyer, W.T.; Atkinson, D.J.

    1980-01-01

    Available data on the Roosevelt area were synthesized to determine the spatial arrangement of the rocks, and the patterns of mass and energy flow within them. The resulting model lead to a new interpretation of the geothermal system, and provided ground truth for evaluating the application of soil geochemistry to exploration for concealed geothermal fields. Preliminary geochemical studies comparing the surface microlayer to conventional soil sampling methods indicated both practical and chemical advantages for the surface microlayer technique, which was particularly evident in the case of As, Sb and Cs. Subsequent multi-element analyses of surface microlayer samples collected over an area of 100 square miles were processed to produce single element contour maps for 41 chemical parameters. Computer manipulation of the multi-element data using R-mode factor analysis provided the optimum method of interpretation of the surface microlayer data. A trace element association of As, Sb and Cs in the surface microlayer provided the best indication of the leakage of geothermal solutions to the surface, while regional mercury trends may reflect the presence of a mercury vapour anomaly above a concealed heat source.

  2. 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.

  3. Stock Price Reactions to Short-Lived Public Information : The Case of Betting Odds

    NARCIS (Netherlands)

    Palomino, F.A.; Renneboog, L.D.R.; Zhang, C.

    2005-01-01

    Stock markets and betting markets co-exist for professional soccer clubs listed on the London Stock Exchange.For each firm, two pieces of information are released to the stock market on a weekly basis from August to June: experts expectations about game outcomes through the betting odds, and the gam

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

    International Nuclear Information System (INIS)

    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 area covered in the conceptual and descriptive modelling is characterised by a low relief and a small-scale topography. Almost the whole area is located below 20 m a s l (metres above sea level). The corrected mean annual precipitation is 600-650 mm and the mean annual evapotranspiration can be estimated to a little more than 400 mm, leaving approximately 200 mm x year-1 for runoff. Till is the dominating Quaternary deposit covering approximately 75% of the area. In most of the area, the till is sandy. Bedrock outcrops are frequent but cover only approximately 5% of the area. Direct groundwater recharge from precipitation is the dominant source of groundwater recharge. 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 sediment stratigraphy of lakes and wetlands is crucial for their function as discharge areas for groundwater. Comparisons between measured lake water levels and groundwater levels below and around lakes indicate that the lakes in some cases may act as sources of groundwater recharge. Specifically, observations from Lake Bolundsfjaerden and Lake Eckarfjaerden show that such conditions were at hand during the dry summer of 2003. However, whether the observed water level relations correspond to significant water fluxes depends also on the hydrogeological properties of the lake sediments and the underlying Quaternary deposits. ''Old'' water with high

  5. 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.

  6. 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.

  7. 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.

  8. Bayesian Ensemble Trees (BET) for Clustering and Prediction in Heterogeneous Data

    Science.gov (United States)

    Duan, Leo L.; Clancy, John P.; Szczesniak, Rhonda D.

    2016-01-01

    We propose a novel “tree-averaging” model that utilizes the ensemble of classification and regression trees (CART). Each constituent tree is estimated with a subset of similar data. We treat this grouping of subsets as Bayesian Ensemble Trees (BET) and model them as a Dirichlet process. We show that BET determines the optimal number of trees by adapting to the data heterogeneity. Compared with the other ensemble methods, BET requires much fewer trees and shows equivalent prediction accuracy using weighted averaging. Moreover, each tree in BET provides variable selection criterion and interpretation for each subset. We developed an efficient estimating procedure with improved estimation strategies in both CART and mixture models. We demonstrate these advantages of BET with simulations and illustrate the approach with a real-world data example involving regression of lung function measurements obtained from patients with cystic fibrosis. Supplemental materials are available online. PMID:27524872

  9. Surface winds in the Euro-Mediterranean area: the real resolution of numerical grids

    Directory of Open Access Journals (Sweden)

    F. Chèruy

    2004-12-01

    Full Text Available Surface wind is a variable of great importance in forcing marine waves and circulations, modulating surface fluxes, etc. Surface wind defined on numerical grids is currently used in forecast-analysis, as well as in climatology. Gridded fields, however, suffer for systematic errors associated with the numerical procedures adopted in computing them. In this paper the climatology of surface wind produced by three different numerical models in the European-Mediterranean area is analyzed. The systematic loss of power at the smallest grid-scales appears in the power spectrum of all the different models. Some prototype numerical integrations show that this systematic over-smoothing is due to numerical stabilization operators that represent the main source of the diagnosed error; the error progression in space and time is also analyzed.

    Key words. Meteorology and atmospheric dynamics (Mesoscale meteorology; Ocean-atmosphere interaction; Climatology

  10. Reinforced Epoxy Nanocomposite Sheets Utilizing Large Interfacial Area from a High Surface Area Single-Walled Carbon Nanotube Scaffold

    Science.gov (United States)

    Kobashi, Kazufumi; Nishino, Hidekazu; Yamada, Takeo; Futaba, Don; Yumura, Motoo; Hata, Kenji

    2011-03-01

    We employed single-walled carbon nanotubes (SWNTs) with the available highest specific surface area (more than 1000 m2/g) that provided very large interfacial area for the matrix to fabricate epoxy composite sheets. Through mechanical redirection of the SWNT alignment to horizontal to create a laterally aligned scaffold sheet, into which epoxy resin was impregnated. The SWNT scaffold was engineered in structure to meet the these two nearly mutually exclusive demands, i.e. to have nanometer meso-pores (2-50 nm) to facilitate homogeneous impregnation of the epoxy resin and to have mechanical strength to tolerate the compaction forces generated during impregnation. Through this approach, a SWNT/epoxy composite sheet with a nearly ideal morphology was realized where long and aligned SWNTs were loaded at high weight fraction (33 percent) with an intertube distance approaching the radius of gyration for polymers. The resultant composite showed a Young's modulus of 15.0 GPa and a tensile strength of 104 MPa, thus achieving 5.4 and 2.1 times reinforcement as compared to the neat epoxy resin.

  11. 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

  12. 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.

  13. High surface area nanocrystalline hausmannite synthesized by a solvent-free route

    International Nuclear Information System (INIS)

    Highlights: ► High surface area Mn3O4 nanoparticles obtained by a solvent-free low temperature route. ► 3,6,9-Trioxadecanoic acid allows to obtain nanocrystalline hausmannite. ► Tape casted electrodes show up to 300 mAh g−1 capacity after more than 40 cycles at a C/3 rate. ► Upper cut off voltage strongly influences capacity retention upon cycling at high C rates. -- Abstract: Nanocrystalline high surface area Mn3O4 powder was obtained at low temperature by a solvent-free route. The precursor was a mixture of manganese (II) acetate, 3,6,9-trioxadecanoic acid (TODA) and ammonium acetate that were intimately mixed by grounding in an agate mortar. Nanocrystalline Mn3O4 was obtained by thermal treatment at 120 °C. Powder X-ray diffraction, selected area electron diffraction, high resolution transmission electron microscopy, and Fourier transformed infrared characterization confirmed the formation of the hausmannite phase. The as-prepared mesoporous material has high specific surface area (120 m2 g−1). The performances of tape casted Mn3O4 nanopowder electrodes were investigated as anode material for lithium ion batteries. High capacity values were achieved at diverse C rates. Capacity fading was found to be dependent on the upper cut off voltage, the presence of a plateau at 2.25 V vs. Li+/Li being detrimental for long term cyclability.

  14. 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.

  15. 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.

  16. 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.

  17. Uncertainty studies of real anode surface area in computational analysis for molten salt electrorefining

    International Nuclear Information System (INIS)

    Highlights: → Numerical electrochemo-fluid modeling of pyrochemical electrorefining in cross comparison with 2D and 3D analysis models. → Benchmark study on cell potential of molten LiCl-KCl electrorefining with Mark-IV electrorefiner containing EBR-II spent fuel. → Determination of real anode surface area profile model governing electrorefining performance. → Identification of uncertainty factors in electrorefining causing disagreements between simulation and experiment. → Fully transient performance analysis of 80 hours Mark-IV electrorefining with multi-species multi-reaction 1D model. - Abstract: This study examines how much cell potential changes with five differently assumed real anode surface area cases. Determining real anode surface area is a significant issue to be resolved for precisely modeling molten salt electrorefining. Based on a three-dimensional electrorefining model, calculated cell potentials compare with an experimental cell potential variation over 80 h of operation of the Mark-IV electrorefiner with driver fuel from the Experimental Breeder Reactor II. We succeeded to achieve a good agreement with an overall trend of the experimental data with appropriate selection of a mode for real anode surface area, but there are still local inconsistencies between theoretical calculation and experimental observation. In addition, the results were validated and compared with two-dimensional results to identify possible uncertainty factors that had to be further considered in a computational electrorefining analysis. These uncertainty factors include material properties, heterogeneous material distribution, surface roughness, and current efficiency. Zirconium's abundance and complex behavior have more impact on uncertainty towards the latter period of electrorefining at given batch of fuel. The benchmark results found that anode materials would be dissolved from both axial and radial directions at least for low burn-up metallic fuels after active

  18. 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.

  19. Assessment of Groundwater and Surface Water Pollution at Mitm Area, Ibb City, Yemen

    Directory of Open Access Journals (Sweden)

    Esmail A. Sabahi

    2009-01-01

    Full Text Available Groundwater and surface water samples were collected from Mitm area to study the possible impact of wastewater treatment percolation into the groundwater and surface water. The objective of the study is to assess the groundwater and surface water pollution due to wastewater treatment at Mitm area of Ibb city, in the Republic of Yemen. The concentrations of various physiochemical parameters include heavy metals (Pb, Zn, Ni, Cr, Cd, Cu pH, temperature, Electrical Conductivity (EC, Total Dissolved Solids (TDS, and Dissolved Oxygen (DO, anions and nutrients (F-, Cl-, SO4-2, NO2, NO3-,NH3-N, major cations (Fe, Na, K, Ca, Mg and parameters (COD, BOD5, and coliform group bacteria were measured from the groundwater samples. The results show that three out of five boreholes are contaminated, where the concentration of physic-chemical parameters are above the standard acceptable levels which required for drinking water adapted by Yemen's Ministry of Water and Environment (YMWE, 1999. On the other hand, surface water is affected by the discharge of untreated wastewater. The concentrations of physiochemical parameters are above the standard acceptable levels which required for irrigation purpose adopted by Yemen's Ministry of Water and Environment (YMWE, 1999. Boreholes 1 and 2 are suitable for drinking water, whereas boreholes 3, 4 and 5 are not suitable for drinking water. Therefore, urgency for wastewater treatment at this site is recommended to prevent further contamination to surface and groundwater.

  20. 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

  1. 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.

    ) INTRODUCTION A number of oC128shore activities area such as exploration for polymetallic nodules, demarcation of EEZ, etc. necessitates the definition of large boundaries on a geographical surface. The area de- marcated by these boundaries have to be calculated... are carried out with these converted coordinates, treating them as linear quan- tities (except for the scale factor calculation). A check is performed by the subroutine VALID to verify the presence of any crossings of the poly- gon sides among each other...

  2. 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...

  3. 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.

  4. 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 ...

  5. 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 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.

  6. 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.

  7. Specific surface area of overlapping spheres in the presence of obstructions

    Science.gov (United States)

    Jenkins, D. R.

    2013-02-01

    This study considers the random placement of uniform sized spheres, which may overlap, in the presence of another set of randomly placed (hard) spheres, which do not overlap. The overlapping spheres do not intersect the hard spheres. It is shown that the specific surface area of the collection of overlapping spheres is affected by the hard spheres, such that there is a minimum in the specific surface area as a function of the relative size of the two sets of spheres. The occurrence of the minimum is explained in terms of the break-up of pore connectivity. The configuration can be considered to be a simple model of the structure of a porous composite material. In particular, the overlapping particles represent voids while the hard particles represent fillers. Example materials are pervious concrete, metallurgical coke, ice cream, and polymer composites. We also show how the material properties of such composites are affected by the void structure.

  8. Phenomenological study of aerosol dry deposition in urban area: surface properties, turbulence and local meteorology influences

    International Nuclear Information System (INIS)

    Aerosol dry deposition is not much known for urban areas due to the lack of data. Knowledge on this phenomenon is necessary to understand pollutant fluxes in cities and to estimate inhabitant exposition to ionizing radiation of radioactive aerosols. A data providing could enable to enhance dry deposition models for these areas. An original experimental approach is performed to study submicron aerosol dry deposition on urban surfaces. Wind tunnel coupled to in situ experiments give results to study different physical phenomenon governing dry deposition. Dry deposition velocities are measured using aerosol tracers. These data are associated to turbulent and meteorological measured conditions. This database permits to classify the principal physical phenomenon for each experiment type. Finally, different phenomenon must be considered for chronic and acute exposition of urban surfaces to atmospheric particles. (author)

  9. 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.

  10. 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.

  11. 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.

  12. Video inspection of lattice tube rolled joint area with structured lighting for enhanced surface profiling

    International Nuclear Information System (INIS)

    Retube Tubesheet Bore Dressing is a series of operations being performed by the Bruce Retube Project between calandria tube removal and installation of the new calandria tubes. Specialized remotely-operated tooling has been designed and developed to perform the task to ensure proper tubesheet bore conditions prior to making the new calandria tube rolled joint. A key part of the tool is the video inspection module. During operation, the module scans the area to ensure proper tool location and to assess surface condition. The tool may then be used to perform either rotary brushing or milling to improve the groove profile. Following dressing, the system re-inspects the bore to verify the operation. The tool may also perform a video inspection of the inboard section of the lattice tube and verify the condition of the inboard bearing. In order to enhance the operator's ability to evaluate the machined surface, structured lighting has been used, consisting of an axially projected laser light stripe. This was included in the design to better define the surface profile during scanning. Surface inspection images are shown to demonstrate the performance of the unit. By analysing a series of captured images from the surface scan, both a surface profile and diametral measurements of the tubesheet bore can be calculated, extending the technique from a qualitative to a quantitative method. (author)

  13. 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.

  14. [Distribution, surface and protected area of palm-swamps in Costa Rica and Nicaragua].

    Science.gov (United States)

    Serrano-Sandí, Juan; Bonilla-Murillo, Fabian; Sasa, Mahmood

    2013-09-01

    In Central America, palm swamps are known collectively as yolillales. These wetlands are usually dominated by the raffia palm Raphia taedigera, but also by the royal palm Manicaria saccifera and -in lower extensions- by the American oil palm Elaeis oleifera. The yolillales tend to be poor in woody species and are characteristic of regions with high rainfall and extensive hydroperiods, so they remain flooded most of the year. The dominance of large raffia palm leaves in the canopy, allow these environments to be distinguishable in aerial photographs, which consequently has helped to map them along most of their distribution. However, while maps depicting yolillales are available, the extent of their surface area, perimeter and connectivity remains poorly understood. This is particularly true for yolillales in Costa Rica and Nicaragua, countries that share a good proportion of palm dominated swaps in the Rio San Juan Basin. In addition, it is not known the actual area of these environments that is under any category of protection according to the conservation systems of both countries. As a first step to catalog yolillal wetlands in Costa Rica and Nicaragua, this paper evaluates cartographic maps to delineate yolillales in the region. A subsample of yolillales mapped in this study were visited and we geo-referenced them and evaluate the extent and condition of the swamp. A total of 110 883.2ha are classified as yolillales in Nicaragua, equivalent to 22% of wetland surface area recorded for that country (excluding the Cocibolca and Xolothn Lakes). In Costa Rica, 53 931.3ha are covered by these palm dominated swamps, which represent 16.24% of the total surface area covered by wetlands. About 47% of the area covered by yolillales in Nicaragua is under some category of protection, the largest extensions protected by Cerro Silva, Laguna Tale Sulumas and Indio Maiz Nature Reserves. In Costa Rica, 55.5% of the area covered by yolillal is located within protected areas

  15. The Average Body Surface Area of Adult Cancer Patients in the UK: A Multicentre Retrospective Study

    OpenAIRE

    Sacco, Joseph J.; Joanne Botten; Fergus Macbeth; Adrian Bagust; Peter Clark

    2010-01-01

    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 ...

  16. Sol-gel preparation of low oxygen content, high surface area silicon nitride and imidonitride materials.

    Science.gov (United States)

    Sardar, Kripasindhu; Bounds, Richard; Carravetta, Marina; Cutts, Geoffrey; Hargreaves, Justin S J; Hector, Andrew L; Hriljac, Joseph A; Levason, William; Wilson, Felix

    2016-04-01

    Reactions of Si(NHMe)4 with ammonia are effectively catalysed by small ammonium triflate concentrations, and can be used to produce free-standing silicon imide gels. Firing at various temperatures produces amorphous or partially crystallised silicon imidonitride/nitride samples with high surface areas and low oxygen contents. The crystalline phase is entirely α-Si3N4 and structural similarities are observed between the amorphous and crystallised materials. PMID:26931152

  17. Nanotextured gold coatings on carbon nanofiber scaffolds as ultrahigh surface-area electrodes

    OpenAIRE

    COLAVITA, PAULA

    2012-01-01

    PUBLISHED High surface area metal electrodes are desirable for applications in energy storage and energy conversion. Here, the formation and electrochemical characterization of a hybrid material made by electroless deposition of gold onto a scaffolding of vertically aligned carbon nanofibers is described. Vertically aligned carbon nanofibers, ~80 nm in diameter, provided mechanical support and electrical contact to the highly textured nanoscale gold coatings. By chemically functionalizing ...

  18. 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.

  19. METHODS TO DETECT ATMOSPHERIC AND SURFACE HEAT ISLANDS IN URBAN AREAS

    OpenAIRE

    I. HERBEL; A. E. CROITORU; A. M. IMBROANE; D. PETREA

    2015-01-01

    Intensification of the urbanization process and its associated climatic effects is nowadays a major problem of large cities worldwide. One of these climatic effects is the urban heat island (UHI), that implies increased air and surface temperature values in the city when compared to the nearby rural areas. This phenomenon threatens the health of the population, especially during heat waves, affects the quality of the environment and the quality of life, and also generates significant costs to...

  20. 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.

  1. Association of body surface area and body composition with heart structural characteristics of female swimmers

    OpenAIRE

    SHEIKHSARAF, BAHAREH; ALLAH, NIKBAKHT HOJAT; ALI, AZARBAYJANI MOHAMMAD

    2010-01-01

    In healthy nonathletic populations, some left ventricle (LV) parameters such as LV mass (LVM) and LV end diastolic dimension (LVEDD) can be predicted by some of body size parameters such as body surface area (BSA), fat-free mass (FFM), and height (H). These body size parameters use to remove covariate influence of body size from cardiac dimension variables and allow comparisons to be made between individuals and groups of different body size. Endurance exercise has been associated with change...

  2. Monolithic nanoporous gold disks with large surface area and high-density plasmonic hot-spots

    Science.gov (United States)

    Zhao, Fusheng; Zeng, Jianbo; Arnob, Md Masud Parvez; Santos, Greggy M.; Shih, Wei-Chuan

    2015-03-01

    Plasmonic metal nanostructures have shown great potential in sensing, photovoltaics, imaging and biomedicine, principally due to enhancement of the local electric field by light-excited surface plasmons, the collective oscillation of conduction band electrons. Thin films of nanoporous gold have received a great deal of interest due to the unique 3- dimensional bicontinuous nanostructures with high specific surface area. However, in the form of semi-infinite thin films, nanoporous gold exhibits weak plasmonic extinction and little tunability in the plasmon resonance, because the pore size is much smaller than the wavelength of light. Here we show that by making nanoporous gold in the form of disks of sub-wavelength diameter and sub-100 nm thickness, these limitations can be overcome. Nanoporous gold disks (NPGDs) not only possess large specific surface area but also high-density, internal plasmonic "hot-spots" with impressive electric field enhancement, which greatly promotes plasmon-matter interaction as evidenced by spectral shifts in the surface plasmon resonance. In addition, the plasmonic resonance of NPGD can be easily tuned from 900 to 1850 nm by changing the disk diameter from 300 to 700 nm. The coupling between external and internal nanoarchitecture provides a potential design dimension for plasmonic engineering. The synergy of large specific surface area, high-density hot spots, and tunable plasmonics would profoundly impact applications where plasmonic nanoparticles and non-plasmonic mesoporous nanoparticles are currently employed, e.g., in in-vitro and in-vivo biosensing, molecular imaging, photothermal contrast agents, and molecular cargos.

  3. Glacier melting and precipitation trends detected by surface area changes in Himalayan ponds

    Science.gov (United States)

    Salerno, Franco; Thakuri, Sudeep; Guyennon, Nicolas; Viviano, Gaetano; Tartari, Gianni

    2016-07-01

    Climatic time series for high-elevation Himalayan regions are decidedly scarce. Although glacier shrinkage is now sufficiently well described, the changes in precipitation and temperature at these elevations are less clear. This contribution shows that the surface area variations of unconnected glacial ponds, i.e. ponds not directly connected to glacier ice, but that may have a glacier located in their hydrological basin, can be considered as suitable proxies for detecting past changes in the main hydrological components of the water balance. On the south side of Mt Everest, glacier melt and precipitation have been found to be the main drivers of unconnected pond surface area changes (detected mainly with Landsat imagery). In general, unconnected ponds have decreased significantly by approximately 10 ± 5 % in terms of surface area over the last 50 years (1963-2013 period) in the study region. Here, an increase in precipitation occurred until the mid-1990s followed by a decrease until recent years. Until the 1990s, glacier melt was constant. An increase occurred in the early 2000s, while a declining trend in maximum temperature has caused a reduction in the glacier melt during recent years.

  4. 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

    2013-12-01

    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. PMID:24514516

  5. Surface area, crystal morphology and characterization of transition alumina powders from a new gibbsite precursor

    Directory of Open Access Journals (Sweden)

    Antonio Carlos Vieira Coelho

    2007-06-01

    Full Text Available A new procedure was used to prepare a microcrystalline powder constituted by thin euhedral hexagonal gibbsite plates, 0.2 to 0.6 µm in diameter and 32 nm thick. The powder, fired between 200 and 1000 °C, produced chi and kappa transition aluminas. Alpha-alumina is formed from 1000 °C and recrystallized up to 1500 °C. At 1000 °C, kappa- and alpha-alumina coexisted, but kappa-alumina could only be characterized by SAED. The details of the internal organization of the transition alumina pseudomorphs were clearly observable in TEM due to the great thinness of the I-gibbsite plates. The specific surface area varied from pristine I-gibbsite (24.9 m².g-1 to chi- and kappa transition aluminas (25.4 m².g-1 at 1000 °C to alpha-alumina (4.0 m².g-1 at 1500 °C. The maximum value of specific surface area is 347 m².g-1 in chi-alumina powder at 300 °C, a difference from Bayer gibbsite, in which the chi-alumina highest surface area is 370 m².g-1 at 400 °C.

  6. 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)

  7. Calculation of 8-methoxypsoralen dose according to body surface area in PUVA treatment

    Energy Technology Data Exchange (ETDEWEB)

    Sakuntabhai, A.; Farr, P.M. [Royal Victoria Infirmary, Newcastle upon Tyne (United Kingdom). Dept. of Dermatology; Diffey, B.L. [Dryburn Hospital, Durham (United Kingdom). Regional Medical Physics Department

    1995-12-01

    In 41 patients about to start PUVA, the dose of 8-methoxypsoralen (8-MOP) was calculated conventionally according to body weight (0.6 mg/kg), or according to body surface area (25 mg/m{sup 2}) predicted from height and weight measurements. The two different methods of dosing were used on consecutive treatment days and the plasma 8-MOP concentration was measured on each occasion 2 h after ingestion of the crystalline form of 8-MOP, given to the nearest 10 mg. Body weight calculated doses ranged from 30 to 60 mg with a significant difference in the plasma 8-MOP concentration between the dose groups, indicating a systematic variation according to the weight of the patient. When calculated according to body surface area, only two doses were used (40 or 50 mg), and there was no significant difference in plasma 8-MOP concentration between the groups. Calculation of the dose of 8-MOP using body surface area may be performed quickly and simply provided the height and weight of individual patients is known. We provide evidence that this method of dosing will improve the therapeutic effect of PUVA in psoriasis. (Author).

  8. Large area and deep sub-wavelength interference lithography employing odd surface plasmon modes

    Science.gov (United States)

    Liu, Liqin; Luo, Yunfei; Zhao, Zeyu; Zhang, Wei; Gao, Guohan; Zeng, Bo; Wang, Changtao; Luo, Xiangang

    2016-07-01

    In this paper, large area and deep sub-wavelength interference patterns are realized experimentally by using odd surface plasmon modes in the metal/insulator/metal structure. Theoretical investigation shows that the odd modes possesses much higher transversal wave vector and great inhibition of tangential electric field components, facilitating surface plasmon interference fringes with high resolution and contrast in the measure of electric field intensity. Interference resist patterns with 45 nm (∼λ/8) half-pitch, 50 nm depth, and area size up to 20 mm × 20 mm were obtained by using 20 nm Al/50 nm photo resist/50 nm Al films with greatly reduced surface roughness and 180 nm pitch exciting grating fabricated with conventional laser interference lithography. Much deeper resolution down to 19.5 nm is also feasible by decreasing the thickness of PR. Considering that no requirement of expensive EBL or FIB tools are employed, it provides a cost-effective way for large area and nano-scale fabrication.

  9. 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.

  10. Surface area and pore size distribution of activated carbon produced from low cost precursors

    International Nuclear Information System (INIS)

    Fast growing wood (Paulownia tomentos-PT, Ailanthus altissima-AA. Salvadara oleoides-SO) and animal bones were utilized for the preparation of activated carbon. The carbon samples were activated by thermal means (400-1000 degree C). The samples were characterized by surface area (Langmuir and BJH) with micropore and meso pores volume (BJH). The surface area of other carbon samples activated at 800 degree C was found in the sequence: 654.9 for Salvadora oleoides > 615.8 for Ailanthus altissima > 346.3 for Paulownia tomentosa > 300.0 for animal bones. BJH surface area (m/sup 2/g/sup -l/) analysis of the carbon samples activated at 800 degree C was found in the sequence: 274.6 for Salvadora oleoides > 261.76 for animal bones> 224.8 for Paulownia tomentosa > 200.2 for Ailanthus altissima. The micropore volume (BJH method) of 800 degree C activated carbon samples were in the sequence: 0.15 for Ailanthus altissima > 0.13 for Salvadora oleoides > 0.08 for animal bones. (author)

  11. ERROR BOUNDS FOR SURFACE AREA ESTIMATORS BASED ON CROFTON’S FORMULA

    Directory of Open Access Journals (Sweden)

    Markus Kiderlen

    2011-05-01

    Full Text Available According to Crofton's formula, the surface area S(A of a sufficiently regular compact set A in Rd is proportional to the mean of all total projections pA (u on a linear hyperplane with normal u, uniformly averaged over all unit vectors u. In applications, pA (u is only measured in k directions and the mean is approximated by a finite weighted sum bS(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 bS (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 in the sense that the relative error of the surface area estimator is very close to the minimal error.

  12. 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.

  13. METHODS TO DETECT ATMOSPHERIC AND SURFACE HEAT ISLANDS IN URBAN AREAS

    Directory of Open Access Journals (Sweden)

    I. HERBEL

    2015-10-01

    Full Text Available Intensification of the urbanization process and its associated climatic effects is nowadays a major problem of large cities worldwide. One of these climatic effects is the urban heat island (UHI, that implies increased air and surface temperature values in the city when compared to the nearby rural areas. This phenomenon threatens the health of the population, especially during heat waves, affects the quality of the environment and the quality of life, and also generates significant costs to ensure the inhabitants' thermal comfort. In this study we present a review of the UHI concept and three of the main methods used to detect the atmospheric and surface urban heat islands. Satellite image data analysis seems an easier and time-saving solution, but due to its limitations, we consider that a combination of both surfaces and lower atmospheric layer temperature data analysis is the best choice in order to get accurate results of the intensity and spatial extension of the UHI.

  14. 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

  15. 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.

  16. Towards evidence-based emergency medicine: Best BETs from the Manchester Royal Infirmary.

    Science.gov (United States)

    Mackway-Jones, Kevin C

    2013-07-01

    Best Evidence Topic reports (BETs) summarise the evidence pertaining to particular clinical questions. They are not systematic reviews, but rather contain the best (highest level) evidence that can be practically obtained by busy practicing clinicians. The search strategies used to find the best evidence are reported in detail in order to allow clinicians to update searches whenever necessary. Each BET is based on a clinical scenario and ends with a clinical bottom line which indicates, in the light of the evidence found, what the reporting clinician would do if faced with the same scenario again. The BETs published below were first reported at the Critical Appraisal Journal Club at the Manchester Royal Infirmary¹ or placed on the BestBETs website. Each BET has been constructed in the four stages that have been described elsewhere.² The BETs shown here together with those published previously and those currently under construction can be seen at http://www.bestbets.org.³ Three BETs are included in this issue of the journal. Capillary blood gases as an alternative to arterial puncture in diabetic ketoacidosis. Effect of warming local anaesthetics on pain of infiltration. Use of tamsulosin in patients with urinary calculi to increase spontaneous stone passage. PMID:23765766

  17. Liquidity, Market Efficiency and the Influence of Noise Traders: Quasi-Experimental Evidence from the Betting Industry

    OpenAIRE

    Raphael Flepp; Stephan Nüesch; Egon Franck

    2013-01-01

    This paper examines how liquidity affects market efficiency in a market environment where securities' true values are revealed at a predetermined point in time. We employ differences in minimum tick sizes at the betting exchange Betfair as a source of exogenous variation in liquidity. The results show that liquidity significantly decreases market efficiency for bets on weekend matches but not for bets on weekday matches. Because uninformed noise bettors are more likely to bet on weekends than...

  18. Near-Surface Seismic Refraction Methods to Characterize Areas of Karst Geology near Carlsbad, NM

    Science.gov (United States)

    Cafferky, S.; Bonal, N. D.; Barnhart, K.

    2012-12-01

    Near-surface seismic refraction methods applied to karst geology can give some ideas as to the nature of the void spaces as well as the stratigraphy of the area. A seismic geophone array was laid out near Carlsbad, NM, an area known to contain karst features. Using an impact (sledge hammer), seismic data was collected along two intersecting lines of geophones as well as two gridded areas to get three-dimensional information. The data was picked for the first arrivals of the P-wave, which were graphed and examined for changes in slope and inconsistencies in shape. The data analyzed shows a two-layer model and some inconsistencies such as polarity reversals and delayed arrival times that may represent karst features. Additional processing is used to enhances these features and map them in three-dimensions. The mapped features are compared with known karst features in the area (e.g. sinkholes) for ground-truth information. These methods may be used in the future for detection and classification of other near-surface voids. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  19. A Hybrid Surface Energy Balance Approach for Large Scale Evapotranspiration Estimation and Prediction in Agricultural Areas

    Science.gov (United States)

    Neale, C. M.; Vinukollu, R. K.; Chavez, J. L.

    2005-05-01

    Over the last few years, several surface energy balance methods for the estimation of latent heat fluxes from remotely sensed satellite imagery have been introduced and/or refined. These models have shown the ability of obtaining seasonal spatially distributed evapotranspiration fluxes at various scales and over large areas. In the arid western United States, water managers are challenged in balancing the high consumptive use of irrigated agriculture with competing urban and ecological uses of fresh water. Water managers from Irrigation Districts and Federal Agencies such as the US Bureau of Reclamation have a need for improved operational tools for the prediction of evapotranspiration and irrigation water demand on a five to ten day timeframe. The paper will present a hybrid model that couples the surface energy balance approach with a simple empirical reflectance-based crop coefficient model, for estimation and prediction of evapotranspiration over large agricultural areas. The model is applied to a rain-fed intensively cultivated agricultural area, close to Ames, Iowa during the summer of 2002. The satellite, airborne and ground fluxes were collected during the SMACEX 02 experiment. The model is run in both simulation and prediction mode and the derived latent heat fluxes are compared spatially and temporally to aircraft derived fluxes from the USU airborne system and ground measured fluxes at thirteen eddy covariance stations, using appropriate upwind footprint source area functions.

  20. 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

  1. 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.

  2. Surface ozone concentrations and solar radiation in polluted and remote areas in Egypt

    International Nuclear Information System (INIS)

    this work discusses sources of ozone in the troposphere, particularly with regard to the relative contributions of flues from the stratosphere and that created due to photochemical reactions in the troposphere. Measurements of surface ozone at cairo and the oases Dakhla are used as a a comparative study between the formation of ozone in a polluted area and that of clean atmosphere. The daily maximum ozone concentrations found to be 105 ppb in cairo and 52 ppb in Dakhla. The results show that the budget of ozone in the polluted air masses is dominated by photochemistry, and there is a significant correlation between the monthly mean value use of ozone and global radiation. The ozone budget in free troposphere and rural areas, where the diurnal variation is very low compared to that of polluted areas, is governed by vertical transport

  3. 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

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

    International Nuclear Information System (INIS)

    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

  5. Surface connection between different areas in Mediterranean Sea derived from drifter data

    Science.gov (United States)

    Celentano, Paolo; Carlson, Daniel F.; Falco, Pierpaolo; Zambianchi, Enrico

    2016-04-01

    The surface connection of five study areas in the Mediterranean Sea (Sicily Strait, Gulf of Lyon, Ionian Sea, Alborán Sea and Crete Passage) is studied by looking at the statistical properties of near-surface lagrangian trajectories. The choice of the areas is due to the geographical distribution of data and the key role of these sub-basins in the dynamics of the Mediterranean. We used Lagrangian drifter data taken from the Mediterranean Surface Velocity Programme (http://nettuno.ogs.trieste.it/sire/medsvp/). The most common surface drifter used is the CODE-type drifter (Davis, 1985), designed to follow the vertical average velocity of the upper 1 m layer of the water column. The dataset consist of 1547 trajectories, deployed between 1986 and 2015 in all Mediterranean sub basins. By examining the drifter paths through the study areas, we computed transit and residence time, pseudo-Eulerian statistics and connection probabilities. Given the small number of drifters and the non-normal distribution of transit times, it is possible to use a bootstrap method (Efron and Tibshirani, 1986) to estimate the average transit time. In particular, we divided it into forward and backward transit times to consider the time taken by drifters respectively, from the exit of study area to end of its trajectory and from the deployment position to the study area. The main results indicate that the transit time between Sicily Strait and coast of Libya is about 83-103 days and between the Strait and the Gulf of Lyon is approximately 134 days. The time to reach the Adriatic Sea from the Ionian is around 30-40 days; the drifters take around 70 days to go from Alborán Sea to Sardinia channel and 43 days between Crete and the Ionian Sea. The Ionian Sea due has the highest number of drifter trajectories and the highest residence time, about 42 days. Also the Crete Passage has a high value of residence time, approximately 35 days; the other study areas are characterized by residence times of

  6. 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.

  7. A betting interpretation for probabilities and Dempster-Shafer degrees of belief

    CERN Document Server

    Shafer, Glenn

    2010-01-01

    There are at least two ways to interpret numerical degrees of belief in terms of betting: (1) you can offer to bet at the odds defined by the degrees of belief, or (2) you can judge that a strategy for taking advantage of such betting offers will not multiply the capital it risks by a large factor. Both interpretations can be applied to ordinary additive probabilities and used to justify updating by conditioning. Only the second can be applied to Dempster-Shafer degrees of belief and used to justify Dempster's rule of combination.

  8. 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

  9. Digitized generalized areas where surface-water resources likely or potentially are susceptible to groundwater withdrawals in adjacent valleys, Great Basin National Park area, Nevada

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Polygons delineate generalized areas in and around Great Basin National Park where surface-water resources likely or potentially are susceptible to groundwater...

  10. Interaction between surface water areas and groundwater in Hanoi city, Viet Nam

    Science.gov (United States)

    Hayashi, T.; Kuroda, K.; Do Thuan, A.; Tran Thi Viet, N.; Takizawa, S.

    2012-12-01

    Hanoi is the capital of Viet Nam and the second largest city in this country (population: 6.45 million in 2009). Hanoi city has developed along the Red River and has many lakes, ponds and canals. However, recent rapid urbanization of this city has reduced number of natural water areas such as ponds and lakes by reclamation not only in the central area but the suburban area. Canals also have been reclaimed or cut into pieces. Contrary, number of artificial water areas such as fish cultivation pond has rapidly increased. On the other hand, various kind of waste water flows into these natural and artificial water areas and induces pollution and eutrophication. These waste waters also have possibility of pollution of groundwater that is one of major water resources in this city. In addition, groundwater in this area has high concentrations of Arsenic, Fe and NH4. Thus, groundwater use may causes re-circulation of Arsenic. However, studies on the interaction between surface water areas and groundwater and on the role of surface water areas for solute transport with water cycle are a few. Therefore, we focused on these points and took water samples of river, pond and groundwater from four communities in suburban areas: two communities are located near the Red River and other two are far from the River. Also, columnar sediment samples of these ponds were taken and pore water was abstracted. Major dissolved ions, metals and stable isotopes of oxygen and hydrogen of water samples were analyzed. As for water cycle, from the correlation between δ18O and δD, the Red River water (after GNIR) were distributed along the LMWL (δD=8.2δ18O+14.1, calculated from precipitation (after GNIP)). On the other hand, although the pond waters in rainy season were distributed along the LMWL, that in dry season were distributed along the local evaporation line (LEL, slope=5.6). The LEL crossed with the LMWL at around the point of weighted mean values of precipitation in rainy season and of

  11. 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.

  12. 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.

  13. Spatial heterogeneity of satellite derived land surface parameters and energy flux densities for LITFASS-area

    Directory of Open Access Journals (Sweden)

    A. Tittebrand

    2008-08-01

    Full Text Available Remote sensing data provide area integrated information of surface properties in different spatial or temporal resolutions according to different sensor features. Landsat ETM+, Terra MODIS and NOAA-AVHRR surface temperature and spectral reflectance were used to infer further surface parameters and radiant- and energy flux densities for LITFASS-area, a 20×20 km2 heterogeneous area in Eastern Germany, mainly characterized by the land use types forest, crop, grass and water. Based on the Penman-Monteith-approach the actual latent heat flux (L.E, as key quantity of the hydrological cycle, is determined for each sensor in the accordant spatial resolution with an improved parametrization. However, using three sensors, significant discrepancies between the inferred parameters can cause flux distinctions resultant from differences of the sensor filter response functions or atmospheric correction methods. The approximation of MODIS- and AVHRR- derived surface parameters to the reference parameters of ETM (via regression lines and histogram stretching, respectively, further the use of accurate land use classifications (CORINE and a new Landsat-classification, and a consistent parametrization for the three sensors were realized to obtain a uniform base for investigations of the spatial variability. For the target area the spatial heterogeneity is analysed investigating frequency distribution functions (PDF for surface parameters and energy fluxes. PDF is the most promising way to describe subgrid heterogeneity due to the given data in different spatial resolution. Aim of this study is to find typical distribution pattern of parameters (albedo, NDVI for the determination of L.E determined from the highly resolved ETM data within pixel on coarser scale (MODIS, AVHRR. The analyses for 4 scenes in 2002 and 2003 showed that clear distribution-pattern for forest for NDVI and albedo are found. Grass and crop distributions show higher

  14. 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.

  15. 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.

  16. Characteristics of surface O{sub 3} over Qinghai Lake area in Northeast Tibetan Plateau, China

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Zhenxing, E-mail: zxshen@mail.xjtu.edu.cn [Department of Environmental Sciences and Engineering, Xi' an Jiaotong University, Xi' an (China); Key Lab of Aerosol, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi' an (China); Cao, Junji [Key Lab of Aerosol, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi' an (China); Zhang, Leiming [Air Quality Research Division, Environment Canada, Toronto (Canada); Zhao, Zhuzi [Key Lab of Aerosol, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi' an (China); Dong, Jungang [School of Architecture, Xi' an University of Architecture and Technology, Xi' an 710055 (China); Wang, Linqing [Department of Environmental Sciences and Engineering, Xi' an Jiaotong University, Xi' an (China); Wang, Qiyuan; Li, Guohui; Liu, Suixin [Key Lab of Aerosol, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi' an (China); Zhang, Qian [Department of Environmental Sciences and Engineering, Xi' an Jiaotong University, Xi' an (China)

    2014-12-01

    Surface O{sub 3} was monitored continuously during Aug. 12, 2010 to Jul. 21, 2011 at a high elevation site (3200 m above sea level) in Qinghai Lake area (36°58′37″N, 99°53′56″E) in Northeast Tibetan Plateau, China. Daily average O{sub 3} ranged from 21.8 ppbv to 65.3 ppbv with an annual average of 41.0 ppbv. Seasonal average of O{sub 3} followed a decreasing order of summer > autumn > spring > winter. Diurnal variations of O{sub 3} showed low concentrations during daytime and high concentrations during late night and early morning. An intensive campaign was also conducted during Aug. 13–31, 2010 to investigate correlations between meteorological or chemical conditions and O{sub 3}. It was found that O{sub 3} was poorly correlated with solar radiation due to the insufficient NO{sub x} in the ambient air, thus limiting O{sub 3} formation under strong solar radiation. In contrast, high O{sub 3} levels always coincided with strong winds, suggesting that stratospheric O{sub 3} and long range transport might be the main sources of O{sub 3} in this rural area. Back-trajectory analysis supported this hypothesis and further indicated the transport of air masses from northwest, northeast and southeast directions. - Highlights: • Surface O{sub 3} was measured in Qinghai Lake area in Northeast Tibetan Plateau, China. • The O{sub 3} chemical formation was under a strong NOx-limited in Qinghai Lake areas. • Stratospheric O{sub 3} and transport might be the main sources of O{sub 3} in this area.

  17. Characteristics of surface O3 over Qinghai Lake area in Northeast Tibetan Plateau, China

    International Nuclear Information System (INIS)

    Surface O3 was monitored continuously during Aug. 12, 2010 to Jul. 21, 2011 at a high elevation site (3200 m above sea level) in Qinghai Lake area (36°58′37″N, 99°53′56″E) in Northeast Tibetan Plateau, China. Daily average O3 ranged from 21.8 ppbv to 65.3 ppbv with an annual average of 41.0 ppbv. Seasonal average of O3 followed a decreasing order of summer > autumn > spring > winter. Diurnal variations of O3 showed low concentrations during daytime and high concentrations during late night and early morning. An intensive campaign was also conducted during Aug. 13–31, 2010 to investigate correlations between meteorological or chemical conditions and O3. It was found that O3 was poorly correlated with solar radiation due to the insufficient NOx in the ambient air, thus limiting O3 formation under strong solar radiation. In contrast, high O3 levels always coincided with strong winds, suggesting that stratospheric O3 and long range transport might be the main sources of O3 in this rural area. Back-trajectory analysis supported this hypothesis and further indicated the transport of air masses from northwest, northeast and southeast directions. - Highlights: • Surface O3 was measured in Qinghai Lake area in Northeast Tibetan Plateau, China. • The O3 chemical formation was under a strong NOx-limited in Qinghai Lake areas. • Stratospheric O3 and transport might be the main sources of O3 in this area

  18. 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...

  19. 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... REGULATIONS § 334.1180 Strait of Juan de Fuca, Wash.; air-to-surface weapon range, restricted area. (a)...

  20. 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).

  1. 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.

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

    Science.gov (United States)

    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 and particulate phosphorous 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 indicate 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). PMID:17915711

  3. 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.

  4. Seasonal Distribution of Organic Carbon in the Surface Sediments of the Terengganu Nearshore Coastal Area

    Directory of Open Access Journals (Sweden)

    S. Hasrizal

    2009-01-01

    Full Text Available Problem statement: The distribution of organic carbon in the surface sediment is a crucial indicator for current productivity in the ocean especially in the nearshore area. The difference of organic carbon in the surface sediment reflects the influence of current movement on the bottom sediment. Approach: This study was carried out to oversee the difference of organic carbon distribution during pre and post-monsoon seasons. For the purpose of the study, 42 surface sediments in the Terengganu near shore area were collected and determined for organic carbon by using the wet dichromate acid method. Results: The concentration of organic carbon was significantly different between the seasons showing a relatively higher content during pre-monsoon seasons. In this study, the average concentration of organic carbon in pre-monsoon was 1.14±0.29% and varied from 0.60-1.80%. Meanwhile during post-monsoon seasons, the average concentration of organic carbon was slightly lower to 0.82±0.23% and ranged from 0.24-1.32%. Conclusion: Generally, the average concentration of organic carbon in South China Sea was low compared to the occurrence in riverine environment as well as the mangrove environment.

  5. 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.

  6. 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.

  7. Study of the nitric acid influence on the production of Ce O2 with high specific surface area

    International Nuclear Information System (INIS)

    The cerium oxide (Ce O2) main characteristics for use as catalyst in an exhaust gases purification system are: high specific surface area (approximately 30 m2/g after calcination at 800 deg C/ 2 hs), and thermal stability. The Ce O2 powders obtained by conventional route, i.e., precipitation, and submitted high temperature (800 deg C) heat treatments, showed low specific surface area. In this work nitric acid effects on the Ce O2 surface area values were investigated. The variables studied were nitric acid concentration, humidity content in the raw material, re pulp after leaching, addition of hydrogen peroxide (H2 O2) and starting material specific surface area. By this process, it was possible to obtain powders with specific surface area larger than 40 m2/g, after treatment at 800 deg C during two hours. (author)

  8. 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.

  9. 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...

  10. 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).

  11. Can formaldehyde column densities be used to estimate near-surface ozone in urban areas?

    Science.gov (United States)

    Schroeder, Jason

    2016-04-01

    Understanding pollutant exposure for populations in urban areas requires air quality monitoring at a finer scale than can be reasonably provided by surface networks. Satellite measurements of short-lived trace gases could potentially help shape our understanding of the distribution of near-surface ozone throughout entire regions, thus aiding the development of more effective mitigation strategies. In this work, the extensive vertical profiling performed by aircraft in support of NASA's DISCOVER-AQ field campaign is used to examine the relationship between formaldehyde column measurements and near-surface ozone. At large spatial and temporal scales, a fairly strong relationship exists between column formaldehyde and near-surface ozone, but this relationship often weakens at smaller spatial and temporal scales. The cause of these small-scale discrepancies was determined to be an artifact of the difference in lifetimes between ozone and formaldehyde. While ozone has a long lifetime (multiple days) and tends to accumulate throughout the day, formaldehyde has a very short lifetime (a couple hours) and tends to reflect the local hydrocarbon oxidation environment. In Maryland, where biogenic emissions dominate the hydrocarbon mix, a stronger correlation between ozone and formaldehyde was seen than in Texas, where anthropogenic emissions dominated the hydrocarbon mix. This is because in Maryland, while ozone was accumulating throughout the day, formaldehyde was also increasing in conjunction with changes in biogenic emissions. When data are segregated spatially and averaged over the duration of each campaign, a clear trend can be seen between column formaldehyde and surface ozone measurements. While not useful for day-to-day monitoring, this could be useful for long-term exposure estimates and could help facilitate the re-distribution of surface monitoring sites.

  12. Geomorphometric analysis of fine-scale morphology for extensive areas: a new surface-texture operator

    Science.gov (United States)

    Trevisani, Sebastiano; Rocca, Michele

    2014-05-01

    The application of geomorphometric analysis to high resolution digital terrain models (HRDTM) amplifies our capability to characterize and interpret fine-scale solid earth surface morphology. In this context it is possible to analyze fine-scale morphology in term of surface texture (e.g. Trevisani, 2012; Lucieer, 2005) and retrieve information linked to the different geomorphic processes and factors; this kind of analysis has an interesting potential to be exploited in the context of quantitative geomorphologic/geologic interpretation and geo-engineering. We developed a multiscale texture operator capable to synthetize the main characteristics of local surface texture in an efficient way. The proposed operator can be viewed as an hybrid between classical geostatistical spatial continuity indexes (e.g. variogram, Atkinson, 2000) and the well-known operator based on (rotation invariant) local binary patterns (Ojala, 2002). An important characteristic of the operator is to derive information on surface texture in an easily interpretable form so as to facilitate its use by experts for the interpretation of geomorphic processes and factors. Moreover this surface texture operator could be used for the derivation of more complex and ad-hoc surface texture indexes. We present the application of the operator in the analysis of different HRDTMs, mainly in the context of alpine environment. A particular interesting example is the application of the surface texture analysis in an extensive area (hundreds of km2), including also urbanized zones, and the evaluation of potential links between surface texture and lithological and geo-structural factors. References Atkinson, P.M. & Lewis, P. 2000, "Geostatistical classification for remote sensing: An introduction", Computers and Geosciences, vol. 26, no. 4, pp. 361-371. Lucieer, A., Stein, A., 2005. Texture-based landform segmentation of LiDAR imagery. International Journal of Applied Earth Observation and Geoinformation 6, 261

  13. Energy fluxes and surface characteristics over a cultivated area in Benin: daily and seasonal dynamics

    Directory of Open Access Journals (Sweden)

    O. Mamadou

    2013-08-01

    Full Text Available Latent and sensible heat fluxes are known as key factors in the West African monsoon dynamics. However, few long-term observations of these land surface fluxes are available to document their impact in the climate variability of this region. The present study took advantage of the Sudanian site of the AMMA-CATCH (African Monsoon Multidisciplinary Analysis – Coupling the Tropical Atmosphere and Hydrological Cycle observatory where turbulent fluxes were measured using the eddy covariance technique. One full year of data of energy budget over a cultivated site located in northern Benin was examined. Four contrasted seasons were identified and detailed focusing on their corresponding daily cycles. The flux partitioning was investigated through the evaporative fraction (EF and the Bowen ratio (β at both seasonal and daily scales. Finally, the surface conductance (Gs and the decoupling coefficient (Ω were calculated and confronted with specific bare soil or canopy models to identify the main processes for each season. The results pointed out the contrasted seasonal variations of sensible and latent heat fluxes due to changing atmospheric and surface conditions. During the wet season, surface conditions barely affected EF, which remained in steady regime (EF = 0.75, while latent heat flux was dominant and β was about 0.4. During the transitional periods, both EF and β were highly variable. A low but significant evapotranspiration was measured in the dry season (EF = 0.08 attributed to few scattered bushes, distributed on a bare area, possibly fed by the water table. Nevertheless, sensible heat fluxes were largely dominant (β ~ 10 during dry season. Moreover, β revealed the ligneous vegetation flowering dynamics during the dry season. The results also showed a strong surface atmosphere coupling, which suggests a systematic mixing of the flow within the canopy with the atmospheric surface layer whatever the atmospheric conditions and vegetation

  14. 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.

  15. 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.

  16. Topographic Effects on the Surface Emissivity of a Mountainous Area Observed by a Spaceborne Microwave Radiometer

    Science.gov (United States)

    Pulvirenti, Luca; Pierdicca, Nazzareno; Marzano, Frank S.

    2008-01-01

    A simulation study to understand the influence of topography on the surface emissivity observed by a satellite microwave radiometer is carried out. We analyze the effects 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 the relief extracted from a digital elevation model is exploited. The numerical simulation refers to 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 impact on surface emissivity, scattering of the radiation due to the atmosphere or neighboring elevated surfaces is not considered. C and X bands, for which atmospheric effects are negligible, and Ka band are analyzed. The results indicate that the changes in the local observation angle tend to lower the apparent emissivity of a radiometric pixel with respect to the corresponding flat surface characteristics. The effect of the rotation of the polarization plane enlarges (vertical polarization), or attenuates (horizontal polarization) this decrease. By doing some simplifying assumptions for the radiometer antenna, the conclusion is that the microwave emissivity at vertical polarization is underestimated, whilst the opposite occurs for horizontal polarization, except for Ka band, for which both under- and overprediction may occur. A quantification of the differences with respect to a flat soil and an approximate evaluation of their impact on soil moisture retrieval are yielded.

  17. 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...

  18. Functionality in Electrospun Nanofibrous Membranes Based on Fiber’s Size, Surface Area, and Molecular Orientation

    Directory of Open Access Journals (Sweden)

    Akihiko Tanioka

    2011-08-01

    Full Text Available Electrospinning is a versatile method for forming continuous thin fibers based on an electrohydrodynamic process. This method has the following advantages: (i the ability to produce thin fibers with diameters in the micrometer and nanometer ranges; (ii one-step forming of the two- or three-dimensional nanofiber network assemblies (nanofibrous membranes; and (iii applicability for a broad spectrum of molecules, such as synthetic and biological polymers and polymerless sol-gel systems. Electrospun nanofibrous membranes have received significant attention in terms of their practical applications. The major advantages of nanofibers or nanofibrous membranes are the functionalities based on their nanoscaled-size, highly specific surface area, and highly molecular orientation. These functionalities of the nanofibrous membranes can be controlled by their fiber diameter, surface chemistry and topology, and internal structure of the nanofibers. This report focuses on our studies and describes fundamental aspects and applications of electrospun nanofibrous membranes.

  19. 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...

  20. Adsorption of neon and tetrafluoromethane on carbon nanohorn aggregates: differences in specific surface area values

    Science.gov (United States)

    Krungleviciute, Vaiva; Yudasaka, Masako; Iijima, Sumio; Migone, Aldo

    2008-03-01

    We have measured adsorption isotherms for two different adsorbates, neon and tetrafluoromethane, on dahlia-like carbon nanohorn aggregates. The experiments were performed at similar relative temperatures for both gases. The measurements were conducted to explore the effect of adsorbate diameter on the behavior of the resulting adsorbed systems. We measured the effective specific surface area value of the nanohorn sample using both gases, and we found that this quantity was about 22% smaller when we determined this quantity using tetrafluoromethane, the larger molecule. Isosteric heat and binding energy values were also determined from our measurements. We will compare our experimental results with those from a computer simulation study performed by Prof. M. Calbi. The simulations help us understand the source of the observed differences in the measured specific surface values, as well as the coverage dependence of the isosteric heat of adsorption for both gases.

  1. 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)

  2. 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.

  3. Replication fidelity assessment of large area sub-μm structured polymer surfaces using scatterometry

    International Nuclear Information System (INIS)

    The present study addresses one of the key challenges in the product quality control of transparent structured polymer substrates, the replication fidelity of sub-μm structures over a large area. Additionally the work contributes to the development of new techniques focused on in-line characterization of large nanostructured surfaces using scatterometry. In particular an approach to quantify the replication fidelity of high volume manufacturing processes such as polymer injection moulding is presented. Both periodic channels and semi-spherical structures were fabricated on nickel shims used for later injection moulding of Cyclic-olefin-copolymer (COC) substrate were the sub-μm features where ultimately transferred. The scatterometry system was validated using calibrated atomic force microscopy measurements and a model based on scalar diffraction theory employed to calculate the expected angular distribution of the reflected and the transmitted intensity for the nickel surfaces and structured COC and, respectively. (paper)

  4. Large-Area, Highly Ordered Array of Graphitic Carbon Materials Using Surface Active Chitosan Prepatterns.

    Science.gov (United States)

    Baek, Youn-Kyoung; Kim, Dae Woo; Yang, Seung Bo; Lee, Jung-Goo; Kim, Young Kuk; Jung, Hee-Tae

    2015-02-01

    We demonstrate that chitosan prepatterns can generate not only highly periodic DNA pattern but also various types of graphitic carbon materials such as single-walled carbon nanotubes (SWNTs), graphene oxide (GO) and reduced graphene oxide (RGO). Scanning electron microscopy (SEM), fluorescence imaging and Raman spectroscopic results revealed that the graphitic carbon materials were selectively deposited on the surface of the periodic chitosan patterns by the electrostatic interaction between protonated amine groups of chitosan and the negative charged carbon materials. One proof-of-concept application of the system to the fabrication of electrical devices based on the micropatterns of SWNTs and RGO was also demonstrated. The strategy to use highly surface active chitosan pattern that can easily fabricate highly periodic pattern via a variety of lithographic tools may pave the way for the production of periodic arrays of graphitic carbon materials for large area device integration. PMID:26353637

  5. Loss aversion and mental accounting: The favorite-longshot bias in parimutuel betting

    OpenAIRE

    Qiu, Jianying

    2009-01-01

    Parimutuel betting markets are simpliï¬ ed ï¬ nancial markets, and can thus provide a clearer view of pricing issues which are more complicated elsewhere. Though empirical studies generally conclude that the parimutuel betting markets are surprisingly effcient, it is also found that for horses with lowest odds (favorites), market estimates of winning probabilities are smaller than objective winning probabilities; for horses with highest odds (longshot), the opposite is observed. This phenomen...

  6. Spatial heterogeneity of satellite derived land surface parameters and energy flux densities for LITFASS-area

    Directory of Open Access Journals (Sweden)

    A. Tittebrand

    2009-03-01

    Full Text Available Based on satellite data in different temporal and spatial resolution, the current use of frequency distribution functions (PDF for surface parameters and energy fluxes is one of the most promising ways to describe subgrid heterogeneity of a landscape. Objective of this study is to find typical distribution patterns of parameters (albedo, NDVI for the determination of the actual latent heat flux (L.E determined from highly resolved satellite data within pixel on coarser scale.

    Landsat ETM+, Terra MODIS and NOAA-AVHRR surface temperature and spectral reflectance were used to infer further surface parameters and radiant- and energy flux densities for LITFASS-area, a 20×20 km2 heterogeneous area in Eastern Germany, mainly characterised by the land use types forest, crop, grass and water. Based on the Penman-Monteith-approach L.E, as key quantity of the hydrological cycle, is determined for each sensor in the accordant spatial resolution with an improved parametrisation. However, using three sensors, significant discrepancies between the inferred parameters can cause flux distinctions resultant from differences of the sensor filter response functions or atmospheric correction methods. The approximation of MODIS- and AVHRR- derived surface parameters to the reference parameters of ETM (via regression lines and histogram stretching, respectively, further the use of accurate land use classifications (CORINE and a new Landsat-classification, and a consistent parametrisation for the three sensors were realized to obtain a uniform base for investigations of the spatial variability.

    The analyses for 4 scenes in 2002 and 2003 showed that for forest clear distribution-patterns for NDVI and albedo are found. Grass and crop distributions show higher variability and differ significantly to each other in NDVI but only marginal in albedo. Regarding NDVI-distribution functions NDVI was found to be the key variable for L.E-determination.

  7. 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.

  8. 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.

  9. 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.

  10. 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 ...

  11. Estimation of surface area and pore volume of activated carbons by methylene blue and iodine numbers

    Directory of Open Access Journals (Sweden)

    Cleiton A. Nunes

    2011-01-01

    Full Text Available Data of methylene blue number and iodine number of activated carbons samples were calibrated against the respective surface area, micropore volume and total pore volume using multiple regression. The models obtained from the calibrations were used in predicting these physical properties of a test group of activated carbon samples produced from several raw materials. In all cases, the predicted values were in good agreement with the expected values. The method allows extracting more information from the methylene blue and iodine adsorption studies than normally obtained with this type of material.

  12. Vector cavity solitons in broad area Vertical-Cavity Surface-Emitting Lasers.

    Science.gov (United States)

    Averlant, Etienne; Tlidi, Mustapha; Thienpont, Hugo; Ackemann, Thorsten; Panajotov, Krassimir

    2016-01-01

    We report the experimental observation of two-dimensional vector cavity solitons in a Vertical-Cavity Surface-Emitting Laser (VCSEL) under linearly polarized optical injection when varying optical injection linear polarization direction. The polarization of the cavity soliton is not the one of the optical injection as it acquires a distinct ellipticity. These experimental results are qualitatively reproduced by the spin-flip VCSEL model. Our findings open the road to polarization multiplexing when using cavity solitons in broad-area lasers as pixels in information technology. PMID:26847004

  13. 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.

  14. 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.

  15. 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.)

  16. 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.

  17. Surface water areas significantly impacted 2014 dengue outbreaks in Guangzhou, China.

    Science.gov (United States)

    Tian, Huaiyu; Huang, Shanqian; Zhou, Sen; Bi, Peng; Yang, Zhicong; Li, Xiujun; Chen, Lifan; Cazelles, Bernard; Yang, Jing; Luo, Lei; Jing, Qinlong; Yuan, Wenping; Pei, Yao; Sun, Zhe; Yue, Tianxiang; Kwan, Mei-Po; Liu, Qiyong; Wang, Ming; Tong, Shilu; Brownstein, John S; Xu, Bing

    2016-10-01

    Dengue transmission in urban areas is strongly influenced by a range of biological and environmental factors, yet the key drivers still need further exploration. To better understand mechanisms of environment-mosquito-urban dengue transmission, we propose an empirical model parameterized and cross-validated from a unique dataset including viral gene sequences, vector dynamics and human dengue cases in Guangzhou, China, together with a 36-year urban environmental change maps investigated by spatiotemporal satellite image fusion. The dengue epidemics in Guangzhou are highly episodic and were not associated with annual rainfall over time. Our results indicate that urban environmental changes, especially variations in surface area covered by water in urban areas, can substantially alter the virus population and dengue transmission. The recent severe dengue outbreaks in Guangzhou may be due to the surge in an artificial lake construction, which could increase infection force between vector (mainly Aedes albopictus) and host when urban water area significantly increased. Impacts of urban environmental change on dengue dynamics may not have been thoroughly investigated in the past studies and more work needs to be done to better understand the consequences of urbanization processes in our changing world. PMID:27336234

  18. Response and resistance to BET bromodomain inhibitors in triple-negative breast cancer.

    Science.gov (United States)

    Shu, Shaokun; Lin, Charles Y; He, Housheng Hansen; Witwicki, Robert M; Tabassum, Doris P; Roberts, Justin M; Janiszewska, Michalina; Huh, Sung Jin; Liang, Yi; Ryan, Jeremy; Doherty, Ernest; Mohammed, Hisham; Guo, Hao; Stover, Daniel G; Ekram, Muhammad B; Peluffo, Guillermo; Brown, Jonathan; D'Santos, Clive; Krop, Ian E; Dillon, Deborah; McKeown, Michael; Ott, Christopher; Qi, Jun; Ni, Min; Rao, Prakash K; Duarte, Melissa; Wu, Shwu-Yuan; Chiang, Cheng-Ming; Anders, Lars; Young, Richard A; Winer, Eric P; Letai, Antony; Barry, William T; Carroll, Jason S; Long, Henry W; Brown, Myles; Liu, X Shirley; Meyer, Clifford A; Bradner, James E; Polyak, Kornelia

    2016-01-21

    Triple-negative breast cancer (TNBC) is a heterogeneous and clinically aggressive disease for which there is no targeted therapy. BET bromodomain inhibitors, which have shown efficacy in several models of cancer, have not been evaluated in TNBC. These inhibitors displace BET bromodomain proteins such as BRD4 from chromatin by competing with their acetyl-lysine recognition modules, leading to inhibition of oncogenic transcriptional programs. Here we report the preferential sensitivity of TNBCs to BET bromodomain inhibition in vitro and in vivo, establishing a rationale for clinical investigation and further motivation to understand mechanisms of resistance. In paired cell lines selected for acquired resistance to BET inhibition from previously sensitive TNBCs, we failed to identify gatekeeper mutations, new driver events or drug pump activation. BET-resistant TNBC cells remain dependent on wild-type BRD4, which supports transcription and cell proliferation in a bromodomain-independent manner. Proteomic studies of resistant TNBC identify strong association with MED1 and hyper-phosphorylation of BRD4 attributable to decreased activity of PP2A, identified here as a principal BRD4 serine phosphatase. Together, these studies provide a rationale for BET inhibition in TNBC and present mechanism-based combination strategies to anticipate clinical drug resistance. PMID:26735014

  19. T-bet Activates Th1 Genes through Mediator and the Super Elongation Complex.

    Science.gov (United States)

    Hertweck, Arnulf; Evans, Catherine M; Eskandarpour, Malihe; Lau, Jonathan C H; Oleinika, Kristine; Jackson, Ian; Kelly, Audrey; Ambrose, John; Adamson, Peter; Cousins, David J; Lavender, Paul; Calder, Virginia L; Lord, Graham M; Jenner, Richard G

    2016-06-21

    The transcription factor T-bet directs Th1 cell differentiation, but the molecular mechanisms that underlie this lineage-specific gene regulation are not completely understood. Here, we show that T-bet acts through enhancers to allow the recruitment of Mediator and P-TEFb in the form of the super elongation complex (SEC). Th1 genes are occupied by H3K4me3 and RNA polymerase II in Th2 cells, while T-bet-mediated recruitment of P-TEFb in Th1 cells activates transcriptional elongation. P-TEFb is recruited to both genes and enhancers, where it activates enhancer RNA transcription. P-TEFb inhibition and Mediator and SEC knockdown selectively block activation of T-bet target genes, and P-TEFb inhibition abrogates Th1-associated experimental autoimmune uveitis. T-bet activity is independent of changes in NF-κB RelA and Brd4 binding, with T-bet- and NF-κB-mediated pathways instead converging to allow P-TEFb recruitment. These data provide insight into the mechanism through which lineage-specifying factors promote differentiation of alternative T cell fates. PMID:27292648

  20. T-bet Activates Th1 Genes through Mediator and the Super Elongation Complex

    Directory of Open Access Journals (Sweden)

    Arnulf Hertweck

    2016-06-01

    Full Text Available The transcription factor T-bet directs Th1 cell differentiation, but the molecular mechanisms that underlie this lineage-specific gene regulation are not completely understood. Here, we show that T-bet acts through enhancers to allow the recruitment of Mediator and P-TEFb in the form of the super elongation complex (SEC. Th1 genes are occupied by H3K4me3 and RNA polymerase II in Th2 cells, while T-bet-mediated recruitment of P-TEFb in Th1 cells activates transcriptional elongation. P-TEFb is recruited to both genes and enhancers, where it activates enhancer RNA transcription. P-TEFb inhibition and Mediator and SEC knockdown selectively block activation of T-bet target genes, and P-TEFb inhibition abrogates Th1-associated experimental autoimmune uveitis. T-bet activity is independent of changes in NF-κB RelA and Brd4 binding, with T-bet- and NF-κB-mediated pathways instead converging to allow P-TEFb recruitment. These data provide insight into the mechanism through which lineage-specifying factors promote differentiation of alternative T cell fates.

  1. 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.

  2. T-bet regulates T-independent IgG2a class switching.

    Science.gov (United States)

    Gerth, Andrea J; Lin, Ling; Peng, Stanford L

    2003-08-01

    The IgG2a Ig subclass plays a critical role in the pathogenesis of humoral autoimmunity and protection against pathogens. The T-box transcription factor T-bet has been implicated as a critical mediator of class-switch recombination (CSR) to IgG2a, but its relative importance to this process in various immune contexts remains incompletely defined. We report here that, surprisingly, T-bet is selectively required for IgG2a class switching in response to T-independent, but not T-dependent, stimuli. Specifically, T-dependent signaling through CD40, in contrast to T-independent signaling via lipopolysaccharide, can bypass a requirement for T-bet in IgG2a germline transcription and subsequent isotype switching. In contrast, T-bet-deficient B cells undergo class switching to other IgG isotypes at least as well as wild-type counterparts. Thus, T-bet is a class-specific regulator of IgG CSR and represents a unique regulator of B cell differentiation by participating in a T-independent, but not a T-dependent, activation pathway. T-bet-deficient B cells therefore represent a novel paradigm by which to investigate the regulation of humoral immune responses. PMID:12882831

  3. [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.

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

    Science.gov (United States)

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

    2015-01-01

    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. PMID:25411448

  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. AFM-based tribological study of nanopatterned surfaces: the influence of contact area instabilities

    International Nuclear Information System (INIS)

    Although the importance of morphology on the tribological properties of surfaces has long been proved, an exhaustive understanding of nanopatterning effects is still lacking due to the difficulty in both fabricating ‘really nano-’ structures and detecting their tribological properties. In the present work we show how the probe–surface contact area can be a critical parameter due to its remarkable local variability, making a correct interpretation of the data very difficult in the case of extremely small nanofeatures. Regular arrays of parallel 1D straight nanoprotrusions were fabricated by means of a low-dose focused ion beam, taking advantage of the amorphization-related swelling effect. The tribological properties of the patterns were detected in the presence of air and in vacuum (dry ambient) by atomic force microscopy. We have introduced a novel procedure and data analysis to reduce the uncertainties related to contact instabilities. The real time estimation of the radius of curvature of the contacting asperity enables us to study the dependence of the tribological properties of the patterns from their geometrical characteristics. The effect of the patterns on both adhesion and the coefficient of friction strongly depends on the contact area, which is linked to the local radius of curvature of the probe. However, a detectable hydrophobic character induced on the hydrophilic native SiO2 has been observed as well. The results suggest a scenario for capillary formation on the patterns. (paper)

  8. 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.

  9. Effect of lung injuries on [14C]urea permeability-surface area product in dogs

    International Nuclear Information System (INIS)

    To determine whether [14C]urea permeability-surface area product (PS) is a reliable indicator of changes in permeability in various injuries and its relationship to indicator-dilution and gravimetric lung water contents, we studied six groups of anesthetized, paralyzed, and mechanically ventilated dogs (5 animals each). The groups consisted of control dogs, those injured by intravenous alloxan, oleic acid, or glass beads, and those exposed to acute hypoxia or increased left atrial pressure from volume loading (Pla). Interanimal variation of PS was large (3.0-15.0 ml/s), but successive hourly values in individual animals were stable for 2 h in experimental groups and for 4 h in controls. The PS increased after alloxan, elevated Pla, and 2 h of hypoxia; PS decreased after oleic acid and micremboli. The gravimetric lung water increased after alloxan, oleic acid, and microemboli, and indicator-dilution lung water increased only after alloxan. We conclude (1) that intersubject variability requires normalization to enable detection of significant deviation from base line, and (2) that decreased PS after oleic acid and microvascular injury occurred because vascular obstruction, which decreased surface area, masked probable coexisting increases in capillary permeability

  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. 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

    2015-06-01

    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. PMID:25916491

  12. 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

  13. Spherical torus plasma interactions with large-area liquid lithium surfaces in CDX-U

    International Nuclear Information System (INIS)

    The current drive experiment-upgrade (CDX-U) device at the Princeton Plasma Physics Laboratory (PPPL) is a spherical torus (ST) dedicated to the exploration of liquid lithium as a potential solution to reactor first-wall problems such as heat load and erosion, neutron damage and activation, and tritium inventory and breeding. Initial lithium limiter experiments were conducted with a toroidally-local liquid lithium rail limiter (L3) from the University of California at San Diego (UCSD). Spectroscopic measurements showed a clear reduction of impurities in plasmas with the L3, compared to discharges with a boron carbide limiter. The evidence for a reduction in recycling was less apparent, however. This may be attributable to the relatively small area in contact with the plasma, and the presence of high-recycling surfaces elsewhere in the vacuum chamber. This conclusion was tested in subsequent experiments with a fully toroidal lithium limiter that was installed above the floor of the vacuum vessel. The new limiter covered over ten times the area of the L3 facing the plasma. Experiments with the toroidal lithium limiter have recently begun. This paper describes the conditioning required to prepare the lithium surface for plasma operations, and effect of the toroidal liquid lithium limiter on discharge performance

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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%.

  19. 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.

  20. 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.

  1. 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.

  2. Synthesis of high-surface-area {gamma}-Al{sub 2}O{sub 3} from aluminum scrap and its use for the adsorption of metals: Pb(II), Cd(II) and Zn(II)

    Energy Technology Data Exchange (ETDEWEB)

    Asencios, Yvan J.O., E-mail: yvan@iqsc.usp.br [Instituto de Quimica de Sao Carlos, Universidade de Sao Paulo, Av. Trabalhador Saocarlense, 400, 13560-970, Sao Carlos, SP (Brazil); Sun-Kou, Maria R., E-mail: msun@pucp.edu.pe [Seccion Quimica, Departamento de Ciencias, Pontificia Universidad Catolica del Peru, Av. Universitaria 1801, Lima 32 (Peru)

    2012-10-01

    Highlights: Black-Right-Pointing-Pointer Aluminum hydroxide obtained from aluminum scrap led to the formation of gamma alumina. Black-Right-Pointing-Pointer Acidic pH of precipitation favored the formation of small particles of high surface areas. Black-Right-Pointing-Pointer Higher aging temperature favored the formation of large structures of large pore sizes. Black-Right-Pointing-Pointer Higher aging temperature generated symmetrical solids of regular hexagonal prism forms. Black-Right-Pointing-Pointer Aluminas of large pores adsorbed metals as following: Pb (1.75 Angstrom-Sign ) > Cd (1.54 Angstrom-Sign ) > Zn (1.38 Angstrom-Sign ). - Abstract: Several types of alumina were synthesized from sodium aluminate (NaAlO{sub 2}) by precipitation with sulfuric acid (H{sub 2}SO{sub 4}) and subsequently calcination at 500 Degree-Sign C to obtain {gamma}-Al{sub 2}O{sub 3}. The precursor aluminate was derived from aluminum scrap. The various {gamma}-Al{sub 2}O{sub 3} synthesized were characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), adsorption-desorption of N{sub 2} (S{sub BET}) and scanning electron microscopy (SEM). XRD revealed that distinct phases of Al{sub 2}O{sub 3} were formed during thermal treatment. Moreover, it was observed that conditions of synthesis (pH, aging time and temperature) strongly affect the physicochemical properties of the alumina. A high-surface-area alumina (371 m{sup 2} g{sup -1}) was synthesized under mild conditions, from inexpensive raw materials. These aluminas were tested for the adsorption of Cd(II), Zn(II) and Pb(II) from aqueous solution at toxic metal concentrations, and isotherms were determined.

  3. [Spatial-temporal characteristics of land surface temperature in Tianshan Mountains area based on MODIS data].

    Science.gov (United States)

    Guan, Yan-long; Wang, Rang-hui; Li, Cheng; Yao, Jian; Zhang, Meng; Zhao, Jian-ping

    2015-03-01

    Based on the MODIS/MOD11A2 data from 2001 to 2013, this paper researched the characteristics of land surface temperature (LST) of Tianshan Mountains area. The results indicated that the average of LST in the study area was 1.73 °C , and LST was much higher in the east than in the west. The inter-annual variation range of LST in the northwest was significantly large than in other regions, with the largest above 0.55 °C in some areas. The LST tended to slowly increase with time, and the increase rate was 0.147 °C . a-1. It showed a significant seasonal difference, and the fluctuation of winter was significantly larger than in other seasons with the coefficient of variation reaching 12.7%. The LST difference of day time was greater than that at night, and that in summer was greater than in other seasons. The LST differed with land use types, and the fitted results were inconsistent between the LST and NDVI. With the increase of NDVI of woodland and grassland, the LST decreased dramatically. The LST of construction land and cropland under the influence of human activities had higher sensitivity with NDVI than other land types. PMID:26211048

  4. Application of three-dimensionally area-selective atomic layer deposition for selectively coating the vertical surfaces of standing nanopillars

    Science.gov (United States)

    Dong, Wenjing; Zhang, Kenan; Zhang, Yun; Wei, Tiaoxing; Sun, Yan; Chen, Xin; Dai, Ning

    2014-01-01

    We describe a strategy for selectively coating the vertical surfaces of standing nanopillars using area-selective atomic layer deposition (ALD). Hydrophobic self-assembled monolayers (SAMs) are utilised to selectively inhibit the coating of oxides on the modified horizontal regions to ensure that only the vertical surfaces of vertical standing nanorods are coated using ALD processes. This method makes it possible to fabricate vertical nanodevices using a simple process of depositing oxide layer on a vertical surface, and can also be applied to the area-selective surface passivation of other standing structures. PMID:24662775

  5. 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…

  6. 催化活化法制备杉木基超高比表面积颗粒活性炭%Preparation of Granular Activated Carbon from China Fir with Super-high Surface Area by Catalysis Activation

    Institute of Scientific and Technical Information of China (English)

    朱光真; 邓先伦; 郭昊; 张燕萍

    2014-01-01

    以杉木屑为原料,在传统磷酸法工艺过程中添加辅助催化剂浓硫酸,制备超高比表面积颗粒活性炭。研究浓硫酸添加量、浸渍时间以及浸渍比对颗粒活性炭比表面积的影响。结果表明,浓硫酸添加量和浸渍时间在磷酸法制备超高比表面积颗粒活性炭中发挥着重要的作用,当浸渍时间为15 h、浓硫酸添加量为6%、浸渍比为2.1:1和浸渍时间为5 h、浓硫酸添加量为3%、浸渍比为2.1:1时,分别制备出比表面积为2825、2811 m2/g 的颗粒活性炭、总孔容分别为1.60、1.59 cm3/g,丁烷工作容量分别为154.8、157.3 g/L。%Super-high specific surface area granular activated carbon ( GAC) from China fir sawdust was prepared through adding concentrated sulfuric acid in the traditional technology by phosphoric acid activation method. Influences of different dosage of concentrated sulfuric acid, impregnation time and impregnation ratio on specific surface area was studied. The results showed that both of the dosage of concentrated sulfuric acid and impregnation time had great influence on specific surface area of GAC by phosphoric acid method. The GACs prepared under the conditions of impregnation time 15 h, dosage of concentrated sulfuric acid 6 %, impregnation ratio 2. 1:1 and impregnation time 5h, dosage of concentrated sulfuric acid 3 %, impregnation ratio 2. 1:1 gave the BET surface area of 2 825 and 2 811 m2/g, the total pore volume of 1. 60 and 1. 59 cm3/g, and butane working capacity (BWC) of 154. 8 and 157. 3 g/L, respectively.

  7. 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.

  8. Application of 3D Scanned Imaging Methodology for Volume, Surface Area, and Envelope Density Evaluation of Densified Biomass

    Science.gov (United States)

    Measurement of surface area, volume, and density is an essential for quantifying, evaluating, and designing the biomass densification, storage, and transport operations. Acquiring accurate and repeated measurements of these parameters for hygroscopic densified biomass are not straightforward and on...

  9. 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.

  10. Trajectories of cortical surface area and cortical volume maturation in normal brain development

    Directory of Open Access Journals (Sweden)

    Simon Ducharme

    2015-12-01

    Full Text Available This is a report of developmental trajectories of cortical surface area and cortical volume in the NIH MRI Study of Normal Brain Development. The quality-controlled sample included 384 individual typically-developing subjects with repeated scanning (1–3 per subject, total scans n=753 from 4.9 to 22.3 years of age. The best-fit model (cubic, quadratic, or first-order linear was identified at each vertex using mixed-effects models, with statistical correction for multiple comparisons using random field theory. Analyses were performed with and without controlling for total brain volume. These data are provided for reference and comparison with other databases. Further discussion and interpretation on cortical developmental trajectories can be found in the associated Ducharme et al.׳s article “Trajectories of cortical thickness maturation in normal brain development – the importance of quality control procedures” (Ducharme et al., 2015 [1].

  11. 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.

  12. 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.

  13. 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.

  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. 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 ...

  16. 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.

  17. 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.

  18. 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%).

  19. 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.

  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. A strongly heterogeneous hydrothermal area imaged by surface waves: the case of Solfatara, Campi Flegrei, Italy

    Science.gov (United States)

    Serra, Marcello; Festa, Gaetano; Roux, Philippe; Gresse, Marceau; Vandemeulebrouck, Jean; Zollo, Aldo

    2016-06-01

    We investigated the shallow structure of the Solfatara, a volcano within the Campi Flegrei caldera, southern Italy, using surface waves as a diagnostic tool. We analysed data collected during the RICEN campaign, where a 3-D active seismic experiment was performed on a dense regular grid of 90 m × 115 m using a Vibroseis as the seismic source. After removal of the source time function, we analysed the surface wave contribution to the Green's function. Here, a 1-D approximation can hold for subgrids of 40 m × 40 m. Moreover, we stacked all of the signals in the subgrid according to source-receiver distance bins, despite the absolute location of the source and the receiver, to reduce the small-scale variability in the data. We then analysed the resulting seismic sections in narrow frequency bands between 7 and 25 Hz. We obtained phase and group velocities from a grid search, and a cost function based on the spatial coherence of both the waveforms and their envelopes. We finally jointly inverted the dispersion curves of the phase and group velocities to retrieve a 1-D S-wave model local to the subgrid. Together, the models provided a 3-D description of the S-wave model in the area. We found that the maximum penetration depth is 15 m. In the first 4 m, we can associate the changes in the S-wave field to the temperature gradient, while at greater depths, the seismic images correlate with the resistivity maps, which indicate the water layer close to the Fangaia area and an abrupt variation moving towards the northeast.

  3. Contrast structure and EDLC performances of activated spherical carbons with medium and large surface areas

    International Nuclear Information System (INIS)

    Two spherical carbons of 500 and 3000 m2/g, respectively, activated with NaOH (M500) and KOH (M3000), were examined in relation to their carbon structure and electrochemical behavior to explain their contrast capacitances as EDLC electrode. M500 and M3000 showed capacitances per weight (F/g) and volume (F/ml) of 35 and 35 (M500), 40 and 25 (M3000), respectively. The charge profile of M500 by galvanostat charge indicated that the charge took place rapidly below 1.5 V and then very gradually increased up to the final voltage of 2.7 V in the first charge. Such electrochemical behavior suggests electric field activation of this particular activated carbon at the charge. The charge profile of M3000 was conventional. The structure of M500 suffered a certain marked expansion at the charge, however the 0 0 2 diffractions profile shifted very slightly to a lower angle at the change. Such charge appears reversible while the structure of expansion was more or less irreversible. No expansion was observed with M3000 at the charge to the same voltage. Such a structure allows high efficiency of EDLC due to small pores and electric field activation to induce small pores among the graphitic units. In contrast, M3000 with its larger surface areas of relatively large pores in the graphitic structure showed a larger capacitance per weight. However many useless pores cause lower the capacitance per volume. In addition, large pores lose the efficiency for the formation of an electric double layer per unit surface area of the pore, while the non-graphitic wall of M3000 fails to introduce small pores with a higher capacitance

  4. Renal function maturation in children: is normalization to surface area valid?

    International Nuclear Information System (INIS)

    Full text: Gamma camera DTPA renograms were analysed to measure renal function by the rate at which the kidneys took up tracer from the blood. This was expressed either directly as the fractional uptake rate (FUR), which is not related to body size, or it was converted to a camera-based GFR by the formula GFR blood volume x FUR, and this GFR was normalized to a body surface area of 1.73 m2. Most of the patients studied had one completely normal kidney, and one kidney with reflux but normal function and no large scars. The completely normal kidneys contributed, on average, 50% of the total renal function. The results were considered in age bands, to display the effect of age on renal function. The camera-GFR measurements showed the conventional results of poor renal function in early childhood, with a slow rise to near-adult values by the age of 2 years, and somewhat low values throughout childhood. The uptake values showed a different pattern, with renal function rising to adult equivalent values by the age of 4 months, and with children having better renal function than adults throughout most of their childhood. The standard deviations expressed as coefficients of variation (CV) were smaller for the FUR technique than the GFR (Wilcoxon rank test, P < 0.01). These results resemble recent published measurements of absolute DMSA uptake, which are also unrelated to body size and show early renal maturation. The results also suggest that the reason children have lower serum creatinine levels than adults is that they have better renal function. If this were confirmed, it would raise doubts about the usefulness of normalizing renal function to body surface area in children

  5. Albedo and land surface temperature shift in hydrocarbon seepage potential area, case study in Miri Sarawak Malaysia

    International Nuclear Information System (INIS)

    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

  6. 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.

  7. 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.

  8. Acid/base bifunctional carbonaceous nanomaterial with large surface area: Preparation, characterization, and adsorption properties for cationic and anionic compounds

    International Nuclear Information System (INIS)

    Nanostructured carbonaceous materials are extremely important in the nano field, yet developing simple, mild, and “green” methods that can make such materials possess large surface area and rich functional groups on their surfaces still remains a considerable challenge. Herein, a one-pot and environment-friendly method, i.e., thermal treatment (180 °C; 18 h) of water mixed with glucose and chitosan (CTS), has been proposed. The resultant carbonaceous nanomaterials were characterized by field emitting scanning electron microscope, N2 adsorption/desorption, Fourier transform infrared spectroscope, X-ray photoelectron spectroscopy, and zeta-potential analysis. It was found that, in contrast to the conventional hydrothermally carbonized product from pure glucose, with low surface area (9.3 m2 g−1) and pore volume (0.016 cm3 g−1), the CTS-added carbonaceous products showed satisfactory textural parameters (surface area and pore volume up to 254 m2 g−1 and 0.701 cm3 g−1, respectively). Moreover, it was also interestingly found that these CTS-added carbonaceous products possessed both acidic (–COOH) and basic (–NH2) groups on their surfaces. Taking the advantages of large surface area and –COOH/–NH2 bifunctional surface, the carbonaceous nanomaterials exhibited excellent performance for adsorptions of cationic compound (i.e., methylene blue) at pH 10 and anionic compound (i.e., acid red 18) at pH 2, respectively. This work not only provides a simple and green route to prepare acid/base bifunctional carbonaceous nanomaterials with large surface area but also well demonstrates their potential for application in adsorption. - Highlights: • A simple and green method was proposed to prepare carbon nanomaterials. • The carbon product showed acid/base bifunctional surface with large surface area. • The carbon material could efficiently adsorb both cationic and anionic compounds

  9. Effect of surface area and chemisorbed oxygen on the SO2 adsorption capacity of activated char

    Science.gov (United States)

    Lizzio, A.A.; DeBarr, J.A.

    1996-01-01

    The objective of this study was to determine whether activated char produced from Illinois coal could be used effectively to remove sulfur dioxide from coal combustion flue gas. Chars were prepared from a high-volatile Illinois bituminous coal under a wide range of pyrolysis and activation conditions. A novel char preparation technique was developed to prepare chars with SO2 adsorption capacities significantly greater than that of a commercial activated carbon. In general, there was no correlation between SO2 adsorption capacity and surface area. Temperature-programmed desorption (TPD) was used to determine the nature and extent of carbon-oxygen (C-O) complexes formed on the char surface. TPD data revealed that SO2 adsorption was inversely proportional to the amount of C-O complex. The formation of a stable C-O complex during char preparation may have served only to occupy carbon sites that were otherwise reactive towards SO2 adsorption. A fleeting C(O) complex formed during SO2 adsorption is postulated to be the reaction intermediate necessary for conversion of SO2 to H2SO4. Copyright ?? 1996 Elsevier Science Ltd.

  10. 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.

  11. Study of Radiolaria in the surface sediments from the area east of Taiwan Island

    Institute of Scientific and Technical Information of China (English)

    CHENGZhenbo; SHIXuefa; TANZhiyuan; WUYonghua; WANGKunshan; JUXiaohua

    2004-01-01

    The species and characteristics of Radiolaria in the surface sediments were systematcally investigated in the sea east of Taiwan Island. One hundred and seventy-eight species of Radiolaria (including 21 unidentified species) have been identified in the surface sediments, and they belong to 2 orders, 34 families and 101 genera. Among them there are 19 families, 70 genera, 134 species of Spumellaria and 15 families, 31 genera, 44 species of NasseUaria. Of the 178 species of Radiolaria, the individual number of Spumellaria amounts to 88.1% of the total individual number, and that of Nassellaria amounts to 11.9% of the total individual number. It is shown that most of the dominant species belong to the tropical and subtropical dominant species and are brought into the area mainly by the Kuroshio, and some affecting factors including the submarine topography, submarine sediments, upwelling current east of Taiwan Island and carbonate dissolution play a secondary role in forming the Radiolaria distributions.

  12. Passivation of copper surfaces for selective-area ALD using a thiol self-assembled monolayer

    Science.gov (United States)

    Färm, Elina; Vehkamäki, Marko; Ritala, Mikko; Leskelä, Markku

    2012-07-01

    Self-assembled monolayers (SAMs) of 1-dodecanethiol (CH3(CH2)11SH) were prepared from the vapor phase and used as a passivation layer for selective-area ALD. Thiol SAMs have commonly been prepared by immersing the substrates into a solution containing alkyl thiols. Formation of SAMs from the vapor phase, however, has advantages compared to liquid phase preparation. Passivation of surface can be done as a part of the ALD process forming a SAM first and then continuing with the common ALD process. SAMs can also be applied to three-dimensional structures relying on chemical selectivity of the thiol SAM formation. For example in the copper damascene process the thiol SAMs should form only on the copper surface but not on the insulators. In this study, the SAMs were prepared by placing the substrate and the alkylthiol to the reaction chamber and heating the system to the temperature of 73 °C. Preparation time varied from 0.5 to 24 h. Passivation properties of SAMs were tested with ALD iridium and polyimide processes. Iridium was deposited at 250  ° C for 500 cycles and polyimide at 160  ° C for 20 cycles.

  13. 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)

  14. Surface-water hydrologic data for the Houston metropolitan area, Texas, water years 1990?95

    Science.gov (United States)

    Sneck-Fahrer, Debra A.; Liscum, Fred; East, Jeffrey W.

    2003-01-01

    Most of the Sacramento-San Joaquin Delta was leveed, drained, and converted to agricultural use by the 1930s. Land-surface elevations have since subsided by more than 20 feet in some areas. Subsidence increases the likelihood of levee failure and flooding, which, in turn, jeopardizes water delivery and water quality in the Delta. This is of major concern because the Delta supplies water to two-thirds of California. Previous research has shown that oxidation of peat soils is the primary cause of subsidence in the Delta. Therefore, a possible strategy for remedying this situation is to convert drained agricultural fields back to wetlands, which are flooded at least part of the year. Rehabilitation of wetlands would promote the growth of peat, thereby mitigating and possibly reversing subsidence. This report describes a study that evaluated this strategy. In three experimental enclosures or ponds, carbon inputs were measured in the form of plant biomass and outputs in the form of carbon dioxide (CO2) and methane (CH4) fluxes. Each of the ponds received one of the following water treatments: seasonally flooded, seasonally flooded and irrigated, or permanently flooded. Land-surface elevation, ground-water levels, and soil and air temperature also were measured. This report presents the data collected during the initial phase of the study, which ran from November 1992 through September 1995.

  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. Inhibition of Osteoclastogenesis and Inflammatory Bone Resorption by Targeting BET Proteins and Epigenetic Regulation

    Science.gov (United States)

    Park-Min, Kyung-Hyun; Lim, Elisha; Lee, Min Joon; Park, Sung Ho; Giannopoulos, Eugenia; Yarilina, Anna; van der Meulen, Marjolein; Zhao, Baohong; Smithers, Nicholas; Witherington, Jason; Lee, Kevin; Tak, Paul P.; Prinjha, Rab K.; Ivashkiv, Lionel B.

    2014-01-01

    Emerging evidence suggests that RANKL-induced changes in chromatin state are important for osteoclastogenesis, but these epigenetic mechanisms are not well understood and have not been therapeutically targeted. In this study we find that the small molecule I-BET151 that targets bromo and extra-terminal (BET) proteins that “read” chromatin states by binding to acetylated histones strongly suppresses osteoclastogenesis. I-BET151 suppresses pathologic bone loss in TNF-induced inflammatory osteolysis, inflammatory arthritis, and post-ovariectomy models. Transcriptome analysis identifies a MYC-NFAT axis important for osteoclastogenesis. Mechanistically, I-BET151 inhibits expression of the master osteoclast regulator NFATC1 by suppressing expression and recruitment of its newly identified upstream regulator MYC. MYC is elevated in rheumatoid arthritis and its induction by RANKL is important for osteoclastogenesis and TNF-induced bone resorption. These findings highlight the importance of an I-BET151-inhibited MYC-NFAT axis in osteoclastogenesis, and suggest targeting epigenetic chromatin regulators holds promise for treatment of inflammatory and estrogen deficiency-mediated pathologic bone resorption. PMID:25391636

  17. RVX-297- a novel BD2 selective inhibitor of BET bromodomains.

    Science.gov (United States)

    Kharenko, Olesya A; Gesner, Emily M; Patel, Reena G; Norek, Karen; White, Andre; Fontano, Eric; Suto, Robert K; Young, Peter R; McLure, Kevin G; Hansen, Henrik C

    2016-08-12

    Bromodomains are epigenetic readers that specifically bind to the acetyl lysine residues of histones and transcription factors. Small molecule BET bromodomain inhibitors can disrupt this interaction which leads to potential modulation of several disease states. Here we describe the binding properties of a novel BET inhibitor RVX-297 that is structurally related to the clinical compound RVX-208, currently undergoing phase III clinical trials for the treatment of cardiovascular diseases, but is distinctly different in its biological and pharmacokinetic profiles. We report that RVX-297 preferentially binds to the BD2 domains of the BET bromodomain and Extra Terminal (BET) family of protein. We demonstrate the differential binding modes of RVX-297 in BD1 and BD2 domains of BRD4 and BRD2 using X-ray crystallography, and describe the structural differences driving the BD2 selective binding of RVX-297. The isothermal titration calorimetry (ITC) data illustrate the related differential thermodynamics of binding of RVX-297 to single as well as dual BET bromodomains. PMID:27282480

  18. 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.

  19. 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

  20. 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

    ... stream, in the arid and semiarid regions of the United States, as an initial step in the permit process... application process, to separately determine the applicability of the statutory exclusions set forth in... farm's agricultural productivity and not related to surface coal operations. (c) Summary denial. If...

  1. Polychlorinated biphenyls in surface soil in urban and background areas of Mongolia

    International Nuclear Information System (INIS)

    Polychlorinated biphenyls (PCBs) were measured in soil in some industrial towns (Ulaanbaatar, Suhbaatar, Erdenet, Darhan, Tsetserleg, Hovd, Ulaangom, Altay, Bayanhongor, Arvayheer, Saynshand, Choybalsan) and in background and rural areas of Mongolia. The average sum of all investigated PCB congeners in soil of Mongolia comes to 7.4 ng/g dry weight (DW) and varies from 0.53 ng/g DW till 114 ng/g DW. PCB levels in soil from towns are significantly higher than those in soil from background and rural areas. The PCB homological composition in soil sampled in highly-PCB-polluted sites is similar to the PCB homological pattern in Sovol and Aroclor 1254. Significant correlation between soil organic carbon and low chlorinated PCB both for towns and background sites was found. Significant differences in PCB means in soil in different natural zones were found. -- Highlights: •First study to measure PCBs in surface soil sampled throughout Mongolia. •The PCB patterns in polluted soil were similar to those in Sovol or Aroclor 1254. •Significant differences in PCB means in soil in different natural zones were found. -- Polychlorinated biphenyls were measured in soils throughout Mongolia

  2. 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.

  3. Description of surface systems. Preliminary site description. Forsmark area Version 1.2

    International Nuclear Information System (INIS)

    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

  4. 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

  5. Nanoparticles in natural systems I: The effective reactive surface area of the natural oxide fraction in field samples.

    NARCIS (Netherlands)

    Hiemstra, T.; Antelo, J.; Rahnemaie, R.; Riemsdijk, van W.H.

    2010-01-01

    Information on the particle size and reactive surface area of natural samples is essential for the application of surface complexation models (SCM) to predict bioavailability, toxicity, and transport of elements in the natural environment. In addition, this information will be of great help to enlig

  6. 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.

  7. Molecular simulation of multi-component adsorption processes related to carbon capture in a high surface area, disordered activated carbon

    OpenAIRE

    Di Biase, Emanuela; Sarkisov, Lev

    2015-01-01

    We employ a previously developed model of a high surface area activated carbon, based on a random packing of small fragments of a carbon sheet, functionalized with hydroxyl surface groups, to explore adsorption of water and multicomponent mixtures under conditions representing typical carbon capture processes. Adsorption of water is initialized and proceeds through the growth of clusters around the surface groups, in a process predominantly governed by hydrogen bond interactions. In contrast,...

  8. 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.

  9. Efficiency of the exchange betting market for men's professional tennis: is there a favourite-longshot bias?

    OpenAIRE

    Valtonen, Ville-Veikko

    2013-01-01

    PURPOSE OF THE STUDY: Modern exchange betting markets represent an interesting phenomenon for economists since they closely resemble traditional financial markets. As such, they provide a practical real-life setup for testing the efficient market hypothesis. Unlike many financial assets, bets have finite life periods after which their true payoffs are revealed. Nevertheless, research on exchange betting markets is scarce to date. This thesis aspires to add to the previous literature by pr...

  10. Modification of Surface Roughness and Area of FeCrAl Substrate for Catalytic Converter using Ultrasonic Treatment

    OpenAIRE

    Yanuandri Putrasari; P Untoro; Sulaiman Hasan; Naili Huda; Darwin Sebayang

    2012-01-01

    Surface roughness and area play important role especially in deposition and reaction of the catalyst in the catalytic converter substrate. The aim of this paper is to show the modification of surface roughness and area of FeCrAl substrate for catalytic converter using ultrasonic method. The method was conducted by agitating the FeCrAl in 10 minutes 35 kHz ultrasonic cleaning bath. The  surface roughness, morphology, and chemical components of FeCrAl catalytic converter substrate after ultraso...

  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. Effect of uncertainty in Digital Surface Models on the boundary of inundated areas

    Science.gov (United States)

    Nalbantis, I.; Papageorgaki, I.; Sioras, P.; Ioannidis, Ch.

    2012-04-01

    The planning, design and operation of flood damage reduction works or non-structural measures require the construction of maps that indicate zones to be potentially inundated during floods. Referring to floods due to heavy rainfall, the common procedure for flood mapping consists of the following five computational steps: (1) Frequency analysis of extreme rainfall; (2) construction of design hyetographs for various return periods; (3) construction of the related direct runoff hydrographs; (4) routing of these hydrographs through the hydrographic network; (5) mapping of the inundated area that corresponds to the temporally maximum depth for each location in the flood plain. Steps 3 through 5 require the use of spatial information which can be easily obtained from a Digital Surface Model (DSM). The DSM contains grid-based elevations of the ground or overlying objects that influence the propagation of flood waves. In this work, the SCS-CN method is used in step 3 in combination with a synthetic Unit Hydrograph based on the SCS dimensionless Unit Hydrograph. In step 4, the full one-dimensional Saint Venant equations for non-uniform unsteady flow on fixed bed are used, which are numerically solved. The impact of uncertainty in the DSM on the inundated area boundary is investigated. For this the Monte Carlo simulation method is employed to produce a large number of erroneous DSMs through introducing errors in elevation with a standard deviation equal to σ. These DSMs are then used for delineating potentially flooded areas. The standard deviation of the distance (from the riverbed axis) of the boundary of these areas, herein denoted as σF, is used as the measure of the resulting uncertainty. The link between σ and σF is examined for a spectrum of large return periods (100 to 10000). A computer experiment was set up based on data from two drainage basins. The first basin is located in East Attica and is drained by a branch of the Erasinos Torrent named the South

  13. 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....

  14. 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.

    2015-09-01

    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.

  15. Temporal variations of surface water quality in urban, suburban and rural areas during rapid urbanization in Shanghai, China.

    Science.gov (United States)

    Wang, Junying; Da, Liangjun; Song, Kun; Li, Bai-Lian

    2008-03-01

    As the economic and financial center of China, Shanghai has experienced an extensive urban expansion since the early 1980s, with an attendant cost in environmental degradation. We use an integrated pollution index to study the temporal variations of surface water quality in urban, suburban and rural areas between 1982 and 2005. Data on monitored cross-sections were collected from the Shanghai Environmental Monitoring Center. The results indicated that the spatial pattern of surface water quality was determined by the level of urbanization. Surface water qualities in urban and suburban areas were improved by strengthening the environmental policies and management, but were worsening in rural areas. The relationship between economic growth and surface water quality in Shanghai showed an inversed-U-shaped curve, which reflected a similar pattern in most developed countries. This research suggests that decision makers and city officials should be more aware of the recent pollution increases in Shanghai.

  16. Modification of Surface Roughness and Area of FeCrAl Substrate for Catalytic Converter using Ultrasonic Treatment

    Directory of Open Access Journals (Sweden)

    Yanuandri Putrasari

    2012-03-01

    Full Text Available Surface roughness and area play important role especially in deposition and reaction of the catalyst in the catalytic converter substrate. The aim of this paper is to show the modification of surface roughness and area of FeCrAl substrate for catalytic converter using ultrasonic method. The method was conducted by agitating the FeCrAl in 10 minutes 35 kHz ultrasonic cleaning bath. The  surface roughness, morphology, and chemical components of FeCrAl catalytic converter substrate after ultrasonic treatment were analyzed using atomic force microscope (AFM and examined with scanning electron microscope (SEM in combination with energy dispersive X-ray spectroscopy (EDS. The ultrasonic treatment assisted with Al2O3 powders successfully increased the roughness and surface area of FeCrAl better than SiC powders. 

  17. Dynamic expression of T-bet and GATA3 by regulatory T cells maintains immune tolerance

    OpenAIRE

    Yu, Fang; Sharma, Suveena; Edwards, Julie; Feigenbaum, Lionel; Zhu, Jinfang

    2014-01-01

    Regulatory T (Treg) cells can express the transcription factors T-bet and GATA3 but the function of this expression and whether such cells represent stable subsets is still unknown. By using multiple reporter tools, we show that the expression of T-bet and GATA3 in Treg cells is dynamically influenced by the cytokine environment. Treg cell-specific deletion of either Tbx21 or Gata3 genes singly did not result in loss of Treg cell functions; however, mice with combined deficiency of both genes...

  18. Impact of alternative solid state forms and specific surface area of high-dose, hydrophilic active pharmaceutical ingredients on tabletability.

    Science.gov (United States)

    Paluch, Krzysztof J; Tajber, Lidia; Corrigan, Owen I; Healy, Anne Marie

    2013-10-01

    In order to investigate the effect of using different solid state forms and specific surface area (TBET) of active pharmaceutical ingredients on tabletability and dissolution performance, the mono- and dihydrated crystalline forms of chlorothiazide sodium and chlorothiazide potassium (CTZK) salts were compared to alternative anhydrous and amorphous forms, as well as to amorphous microparticles of chlorothiazide sodium and potassium which were produced by spray drying and had a large specific surface area. The tablet hardness and tensile strength, porosity, and specific surface area of single-component, convex tablets prepared at different compression pressures were characterized. Results confirmed the complexity of the compressibility mechanisms. In general it may be concluded that factors such as solid-state form (crystalline vs amorphous), type of hydration (presence of interstitial molecules of water, dehydrates), or specific surface area of the material have a direct impact on the tabletability of the powder. It was observed that, for powders of the same solid state form, those with a larger specific surface area compacted well, and better than powders of a lower surface area, even at relatively low compression pressures. Compacts prepared at lower compression pressures from high surface area porous microparticles presented the shortest times to dissolve, when compared with compacts made of equivalent materials, which had to be compressed at higher compression pressures in order to obtain satisfactory compacts. Therefore, materials composed of nanoparticulate microparticles (NPMPs) may be considered as suitable for direct compaction and possibly for inclusion in tablet formulations as bulking agents, APIs, carriers, or binders due to their good compactibility performance. PMID:23961942

  19. Lung ventilation injures areas with discrete alveolar flooding, in a surface tension-dependent fashion.

    Science.gov (United States)

    Wu, You; Kharge, Angana Banerjee; Perlman, Carrie E

    2014-10-01

    With proteinaceous-liquid flooding of discrete alveoli, a model of the edema pattern in the acute respiratory distress syndrome, lung inflation over expands aerated alveoli adjacent to flooded alveoli. Theoretical considerations suggest that the overexpansion may be proportional to surface tension, T. Yet recent evidence indicates proteinaceous edema liquid may not elevate T. Thus whether the overexpansion is injurious is not known. Here, working in the isolated, perfused rat lung, we quantify fluorescence movement from the vasculature to the alveolar liquid phase as a measure of overdistension injury to the alveolar-capillary barrier. We label the perfusate with fluorescence; micropuncture a surface alveolus and instill a controlled volume of nonfluorescent liquid to obtain a micropunctured-but-aerated region (control group) or a region with discrete alveolar flooding; image the region at a constant transpulmonary pressure of 5 cmH2O; apply five ventilation cycles with a positive end-expiratory pressure of 0-20 cmH2O and tidal volume of 6 or 12 ml/kg; return the lung to a constant transpulmonary pressure of 5 cmH2O; and image for an additional 10 min. In aerated areas, ventilation is not injurious. With discrete alveolar flooding, all ventilation protocols cause sustained injury. Greater positive end-expiratory pressure or tidal volume increases injury. Furthermore, we determine T and find injury increases with T. Inclusion of either plasma proteins or Survanta in the flooding liquid does not alter T or injury. Inclusion of 2.7-10% albumin and 1% Survanta together, however, lowers T and injury. Contrary to expectation, albumin inclusion in our model facilitates exogenous surfactant activity. PMID:25080924

  20. Electric field-enhanced surface area generation, drop coalescence, and fluid convection

    Energy Technology Data Exchange (ETDEWEB)

    Basaran, O.A. [Purdue Univ., West Lafayette, IN (United States)

    1996-05-01

    The interactions between electric fields and drops or bubbles have been recognized for more than a century and their scientific study was inaugurated by Lord Rayleigh`s seminal paper on the amount of surface charge that is required to destabilize an isolated, conducting liquid drop. Much like Lord Rayleigh, early workers in the field were motivated by the desire to understand the behavior of electrified rain drops in thunder clouds. Indeed, research in the first quarter of the 20th century by John Zeleny and C.T.R. Wilson, who invented the cloud chamber, and the great fluid mechanician G.I. Taylor demonstrated that under an externally applied electric field of sufficient strength, pendant drops and bubbles form conical ends from which issue charged jets. The subject virtually lay dormant the second half of the 20th century when Vonnegut and Neubauer reinvented electro-atomization in the 1950s and Taylor in England and James Melcher at MIT in the US laid the foundations of the modern science of electrohydrodynamics in the 1960s. Building on the works of these early pioneers and those of more recent contributors, a review is presented of the state-of-the art in understanding of how electric fields are and might be used to achieve great improvements in the efficiency of separations processes involving multiphase liquid-liquid and liquid-gas systems. In this presentation, the beneficial effects of an applied electric field on separations are illustrated in the context of solvent extraction. This is a particularly instructive example because in an electrically-driven solvent extractor, dispersion and surface area creation, fluid convection, mass transfer, and coalescence can all be enhanced by the application of an electric field.