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Sample records for surface characteristics influence

  1. The influence of fabric surface characteristics on satellite bloodstain morphology.

    Science.gov (United States)

    Miles, H F; Morgan, R M; Millington, J E

    2014-07-01

    Bloodstains on fabrics such as clothing, soft furnishings or carpets are often encountered in casework. These stains often have a distinctive morphology that includes satellite stains, thought to be a highly sensitive feature that is a function of surface roughness. This study presents the findings of experimental studies conducted with proxy blood on two fabrics, similar in labeled composition, to assess the influence of fabric type on satellite stain generation. The morphology of proxy blood stains on the two fabric types were found to be statistically distinguishable from one another, with the volume of satellite stains generated being dependent upon the surface roughness of the fabric. These findings provide an initial step that illustrates the viability of providing an empirical evidence base for the interpretation of satellite stains in forensic blood pattern analysis (BPA). Copyright © 2014 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.

  2. Influence of shear velocity on frictional characteristics of rock surface

    Indian Academy of Sciences (India)

    Friction at the interface of the rock samples was developed by increasing shear strain at a con- stant rate by applying constant velocity using the tribometer. For shaly sandstone, state para- meters (a and b) played a major role in determining the friction values and roughness of the contact surfaces as well. Higher values of b ...

  3. Influence of shear velocity on frictional characteristics of rock surface

    Indian Academy of Sciences (India)

    Friction at the interface of the rock samples was developed by increasing shear strain at a constant rate by applying constant velocity using the tribometer. For shaly sandstone, state parameters ( and ) played a major role in determining the friction values and roughness of the contact surfaces as well. Higher values of  ...

  4. Influence of the surface layer characteristics on the regularities of the cutting process

    Directory of Open Access Journals (Sweden)

    Krainev Dmitriy V.

    2017-01-01

    Full Text Available The article considers the influence of the surface layer characteristics on the regularities of the cutting process and the formation of the quality of the surface machined. This effect has been confirmed by the study results of the combined cutting method with advanced plastic deformation (APD. The work estimates the impact of the change in the surface layer properties on the forces and temperature of cutting, stability of the chip formation and quality parameters of the surface machined.

  5. Influence of the surface finishing on electrochemical corrosion characteristics of AISI 316L stainless steel

    Directory of Open Access Journals (Sweden)

    Sylvia Dundeková

    2015-05-01

    Full Text Available Stainless steels from 316 group are very often and successfully uses for medical applications where the good mechanical and chemical properties in combination with non-toxicity of the material assure its safe and long term usage. Corrosion properties of AISI 361L stainless steel are strongly influenced by surface roughness and treatment of the engineering parts (specimens and testing temperature. Electrochemical characteristics of ground, mechanically polished and passivated AISI 316L stainless steel specimens were examined with the aim to identify the polarization resistance evolution due to the surface roughness decrease. Results obtained on mechanically prepared specimens where only natural oxide layer created due to the exposure of the material to the corrosion environment was protecting the materials were compared to the passivated specimens with artificial oxide layer. Also the influence of temperature and stabilization time before measurement were taken into account when discussing the obtained results. Positive influence of decreasing surface roughness was obtained as well as increase of polarization resistance due to the chemical passivation of the surface. Increase of the testing temperature and short stabilization time of the specimen in the corrosion environment were observed negatively influencing corrosion resistance of AISI 316L stainless steel.

  6. Influence of the cooling liquid on surface quality characteristics in milling

    Science.gov (United States)

    Tampu, N. C.; Brabie, G.; Chirita, B. A.; Herghelegiu, E.; Radu, M. C.

    2015-11-01

    Cooling system and cooling liquid characteristics are among the main factors influencing surface quality and tool wear. The aim of this study is to analyse the effect of the cooling liquid, used in different concentrations and at different temperatures, on the quality of the surface layer processed by milling. In order to make this analysis a Minimum Quantity Lubrication (MQL) cooling device is used. Three different volumetric ratios were used to modify the concentration of the cooling fluid (25% water to 75% emulsion, 50% water to 50% emulsion, 75% water to 25% emulsion) and three different temperatures. The studies revealed that surface roughness can be correlated with the variation of the cooling liquid temperature while surface flatness can be correlated to both, cooling liquid temperature and concentration.

  7. Influence of skin surface roughness degree on energy characteristics of light scattered by a biological tissue

    Science.gov (United States)

    Barun, V. V.; Ivanov, A. P.

    2017-05-01

    We present the results of modelling of photometric characteristics of light in soft tissues illuminated by a parallel beam along the normal to the surface, obtained with allowance for the skin roughness parameters and the angular structure of radiation approaching the surface from within the tissue. The depth structure of the fluence rate and the spectra of the diffuse reflection of light by the tissue in the interval of wavelengths 300 - 1000 nm are considered. We discuss the influence of the tilt angle variance of rough surface microelements and light refraction on the studied characteristics. It is shown that these factors lead to the reduction of the radiation flux only in the near-surface tissue layer and practically do not affect the depth of light penetration into the tissue. On the other hand, the degree of the surface roughness and the conditions of its illumination from within the tissue essentially affect the coefficient of diffuse reflection of light and lead to its considerable growth compared to the cases of a smooth interface and completely diffuse illumination, often considered to simplify the theoretical problem solution. The role of the roughness of skin surface is assessed in application to the solution of different direct and inverse problems of biomedical optics.

  8. Influence of ground surface characteristics on the mean radiant temperature in urban areas.

    Science.gov (United States)

    Lindberg, Fredrik; Onomura, Shiho; Grimmond, C S B

    2016-09-01

    The effect of variations in land cover on mean radiant temperature (T mrt ) is explored through a simple scheme developed within the radiation model SOLWEIG. Outgoing longwave radiation is parameterised using surface temperature observations on a grass and an asphalt surface, whereas outgoing shortwave radiation is modelled through variations in albedo for the different surfaces. The influence of ground surface materials on T mrt is small compared to the effects of shadowing. Nevertheless, altering ground surface materials could contribute to a reduction in T mrt to reduce the radiant load during heat-wave episodes in locations where shadowing is not an option. Evaluation of the new scheme suggests that despite its simplicity it can simulate the outgoing fluxes well, especially during sunny conditions. However, it underestimates at night and in shadowed locations. One grass surface used to develop the parameterisation, with very different characteristics compared to an evaluation grass site, caused T mrt to be underestimated. The implications of using high temporal resolution (e.g. 15 minutes) meteorological forcing data under partly cloudy conditions are demonstrated even for fairly proximal sites.

  9. Analysis of the Scattering Characteristics of Sea Surface with the Influence from Internal Wave

    Directory of Open Access Journals (Sweden)

    Wei Yi-wen

    2015-06-01

    Full Text Available The internal wave travels beneath the sea surface and modulate the roughness of the sea surface through the wave-current interaction. This makes some dark and bright bands can be observed in the Synthetic Aperture Radar (SAR images. In this paper, we first establish the profile of the internal wave based on the KdV equations; then, the action balance equation and the wave-current interaction source function are used to modify the sea spectrum; finally, the two-scale theory based facet model is combined with the modified sea spectrum to calculate the scattering characteristics of the sea. We have simulated the scattering coefficient distribution of the sea with an internal wave traveling through. The influence on the scattering coefficients and the Doppler spectra under different internal wave parameters and sea state parameters are analyzed.

  10. Influence of activated carbon characteristics on toluene and hexane adsorption: Application of surface response methodology

    Science.gov (United States)

    Izquierdo, Mª Teresa; de Yuso, Alicia Martínez; Valenciano, Raquel; Rubio, Begoña; Pino, Mª Rosa

    2013-01-01

    The objective of this study was to evaluate the adsorption capacity of toluene and hexane over activated carbons prepared according an experimental design, considering as variables the activation temperature, the impregnation ratio and the activation time. The response surface methodology was applied to optimize the adsorption capacity of the carbons regarding the preparation conditions that determine the physicochemical characteristics of the activated carbons. The methodology of preparation produced activated carbons with surface areas and micropore volumes as high as 1128 m2/g and 0.52 cm3/g, respectively. Moreover, the activated carbons exhibit mesoporosity, ranging from 64.6% to 89.1% the percentage of microporosity. The surface chemistry was characterized by TPD, FTIR and acid-base titration obtaining different values of surface groups from the different techniques because the limitation of each technique, but obtaining similar trends for the activated carbons studied. The exhaustive characterization of the activated carbons allows to state that the measured surface area does not explain the adsorption capacity for either toluene or n-hexane. On the other hand, the surface chemistry does not explain the adsorption results either. A compromise between physical and chemical characteristics can be obtained from the appropriate activation conditions, and the response surface methodology gives the optimal activated carbon to maximize adsorption capacity. Low activation temperature, intermediate impregnation ratio lead to high toluene and n-hexane adsorption capacities depending on the activation time, which a determining factor to maximize toluene adsorption.

  11. Influence of urban surface properties and rainfall characteristics on surface water flood outputs - insights from a physical modelling environment

    Science.gov (United States)

    Green, Daniel; Pattison, Ian; Yu, Dapeng

    2017-04-01

    Surface water (pluvial) flooding occurs when excess rainfall from intense precipitation events is unable to infiltrate into the subsurface or drain via natural or artificial drainage channels. Surface water flood events pose a major hazard to urban regions across the world, with nearly two thirds of flood damages in the UK being caused by surface water flood events. The perceived risk of surface water flooding appears to have increased in recent years due to several factors, including (i) precipitation increases associated with climatic change and variability; (ii) population growth meaning more people are occupying flood risk areas, and; (iii) land-use changes. Because urban areas are often associated with a high proportion of impermeable land-uses (e.g. tarmacked or paved surfaces and buildings) and a reduced coverage of vegetated, permeable surfaces, urban surface water flood risk during high intensity precipitation events is often exacerbated. To investigate the influence of urbanisation and terrestrial factors on surface water flood outputs, rainfall intensity, catchment slope, permeability, building density/layout scenarios were designed within a novel, 9m2 physical modelling environment. The two-tiered physical model used consists of (i) a low-cost, nozzle-type rainfall simulator component which is able to simulate consistent, uniformly distributed rainfall events of varying duration and intensity, and; (ii) a reconfigurable, modular plot surface. All experiments within the physical modelling environment were subjected to a spatiotemporally uniform 45-minute simulated rainfall event, while terrestrial factors on the physical model plot surface were altered systematically to investigate their hydrological response on modelled outflow and depth profiles. Results from the closed, controlled physical modelling experiments suggest that meteorological factors, such as the duration and intensity of simulated rainfall, and terrestrial factors, such as model slope

  12. Influence of repetitive pulsed laser irradiation on the surface characteristics of an aluminum alloy in the melting regime

    International Nuclear Information System (INIS)

    Choi, Sung Ho; Jhang, Kyung Young

    2015-01-01

    We have investigated the influence of repetitive near-infrared (NIR) pulsed laser shots in the melting regime on the surface characteristics of an aluminum 6061-T6 alloy. Characteristics of interest include surface morphology, surface roughness, and surface hardness in the melted zone as well as the size of the melted zone. For this study, the proper pulse energy for inducing surface melting at one shot is selected using numerical simulations that calculate the variation in temperature at the laser beam spot for various input pulse energies in order to find the proper pulse energy for raising the temperature to the melting point. In this study, 130 mJ was selected as the input energy for a Nd:YAG laser pulse with a duration of 5 ns. The size of the melted zone measured using optical microscopy (OM) increased logarithmically with an increasing shot number. The surface morphology observed by scanning electron microscopy (SEM) clearly showed a re-solidified microstructure evolution after surface melting. The surface roughness and hardness were measured by atomic force microscopy (AFM) and nano-indentation, respectively. The surface roughness showed almost no variation due to the surface texturing after laser shots over 10. The hardness inside the melted zone was lower than that outside the zone because the β'' phase was transformed to a β phase or dissolved into a matrix.

  13. Influence on grip of knife handle surface characteristics and wearing protective gloves.

    Science.gov (United States)

    Claudon, Laurent

    2006-11-01

    Ten subjects were asked to apply maximum torques on knife handles with either their bare hand or their hand wearing a Kevlar fibre protective glove. Four knife handles (2 roughnesses, 2 hardnesses) were tested. Surface electromyograms of 6 upper limb and shoulder muscles were recorded and subject opinions on both knife handle hardness and friction in the hand were also assessed. The results revealed the significant influence of wearing gloves (pgloves greatly increased the torque independently of the other two parameters. Under the bare hand condition, a 90 degrees ShA slightly rough handle provided the greatest torque. Subject opinion agreed with the observed effects on recorded torque values except for the hardness factor, for which a preference for the 70 degrees ShA value over the 90 degrees ShA value emerged.

  14. Influence of Surface Roughness on Optical Characteristics of Multilayer Solar Cells

    Directory of Open Access Journals (Sweden)

    Lubomir Scholtz

    2014-01-01

    Full Text Available Increasing efficiency of solar cells is still a discussed problem. Even if it is well-known that specially formed substrates as Asahi U-type for solar cells are produced, there is still a continuing attention given to the applications of surface roughness to achieve better light trapping and absorptance in solar cells. It was found out the even an exact interface morphology can play an important role in light trapping. In this paper we focused on the issue how final absorptance of a solar cell structure could be affected and possibly increased. The goal of this article is to show which of interfaces has the greatest influence on specular absorptance of the whole structure.

  15. Quantifying the influence of land-use and surface characteristics on spatial variability in the urban heat island

    Science.gov (United States)

    Hart, Melissa A.; Sailor, David J.

    2009-03-01

    The urban thermal environment varies not only from its rural surroundings but also within the urban area due to intra-urban differences in land-use and surface characteristics. Understanding the causes of this intra-urban variability is a first step in improving urban planning and development. Toward this end, a method for quantifying causes of spatial variability in the urban heat island has been developed. This paper presents the method as applied to a specific test case of Portland, Oregon. Vehicle temperature traverses were used to determine spatial differences in summertime ~2 m air temperature across the metropolitan area in the afternoon. A tree-structured regression model was used to quantify the land-use and surface characteristics that have the greatest influence on daytime UHI intensity. The most important urban characteristic separating warmer from cooler regions of the Portland metropolitan area was canopy cover. Roadway area density was also an important determinant of local UHI magnitudes. Specifically, the air above major arterial roads was found to be warmer on weekdays than weekends, possibly due to increased anthropogenic activity from the vehicle sector on weekdays. In general, warmer regions of the city were associated with industrial and commercial land-use. The downtown core, whilst warmer than the rural surroundings, was not the warmest part of the Portland metropolitan area. This is thought to be due in large part to local shading effects in the urban canyons.

  16. The Influence of Ballistic Damage on the Aeroelastic Characteristics of Lifting Surfaces.

    Science.gov (United States)

    1979-07-01

    tunnel wall was sealed with a flexible rubber gasket. The pressure measurements were made using Scanivalve pressure multiplexers and DRUCK pressure...discharge, having a 1.52 by 2.13 m (5 x 7 ft) test section. The drive system comprises four fans of 200 hp each, DRUCK model PDCR differential pressure...3, 4, 5, 6, 8, 9 Surface # IC LS 1 3 2 2 4 2 3 2 2 4 3 2 5 4 2 6 2 2 7 3 3 8 4 3 9 2 3 Damaged - Cases: ID, 2D, 3D , 4D, 5D, 6D, 8D, 9D 1 .Surface # IC

  17. Influence of surface texture on the galling characteristics of lean duplex and austenitic stainless steels

    DEFF Research Database (Denmark)

    Wadman, Boel; Eriksen, J.; Olsson, M.

    2010-01-01

    Two simulative test methods were used to study galling in sheet forming of two types of stainless steel sheet: austenitic (EN 1.4301) and lean duplex LDX 2101 (EN 1.4162) in different surface conditions. The pin-on-disc test was used to analyse the galling resistance of different combinations...

  18. Influence of the surface finishing on electrochemical corrosion characteristics of AISI 316L stainless steel

    Czech Academy of Sciences Publication Activity Database

    Dundeková, S.; Hadzima, B.; Fintová, Stanislava

    2015-01-01

    Roč. 22, č. 2 (2015), s. 77-84 ISSN 1335-0803 Institutional support: RVO:68081723 Keywords : AISI 316L stainless steel * EIS * Corrosion Subject RIV: JK - Corrosion ; Surface Treatment of Materials http://ojs.mateng.sk/index.php/Mateng/article/view/167/278

  19. Influence of silver doping on surface defect characteristics of TiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Tripathi, S. K., E-mail: surya@pu.ac.in [Department of Physics, Center of Advanced Study in Physics, Panjab University, Chandigarh-160 014 (India); Rani, Mamta [Department of Physics, Center of Advanced Study in Physics, Panjab University, Chandigarh-160 014 (India); Department of Physics, DAV University Jalandhar, - 144 001, Punjab (India)

    2015-08-28

    In the present work, we proposed a novel silver doped TiO{sub 2} polyethylene conjugated films to improve the performance of DSSCs. Oxides nanoparticles dispersed in a semiconducting polymer form the active layer of a solar cell. Localized surface plasmon resonance effects associated with spatially dispersed silver (Ag) nanoparticles can be exploited to enhance the light-harvesting efficiency, the photocurrent density and the overall light-to electrical-energy-conversion efficiency of high-area DSSCs based TiO{sub 2} photoanodes. Silver doped titanium dioxide (TiO{sub 2}:Ag) is prepared by sol-gel technique and deposited on fluorine doped indium oxide (FTO) coated glass substrates by using doctor blade technique at 550°C from aqueous solutions of titanium butoxide and silver nitrate precursors. The effect of Ag doping on electrical properties of films is studied. The Ag-TiO{sub 2} films are about 548 times more photosensitive as compare to the pure TiO{sub 2} sample. The presence of metallic Ag nanoparticles and oxygen vacancy on the surface of TiO{sub 2} nanoparticles promotes the separation of photogenerated electron-hole pairs and thus enhances the photosensitivity. Photoconduction mechanism of all prepared samples is investigated by performing transient photoconductivity measurements on TiO{sub 2} and Ag-TiO{sub 2} films keeping intensity of light constant.

  20. Oxidative regeneration of toluene-saturated natural zeolite by gaseous ozone: The influence of zeolite chemical surface characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Alejandro, Serguei [Laboratorio de Tecnologías Limpias (F. Ingeniería), Universidad Católica de la Santísima Concepción, Alonso de Ribera 2850, Concepción (Chile); Núcleo de Energías Renovables (F. Ingeniería), Universidad Católica de Temuco, Rudecindo Ortega 02950, Temuco (Chile); Valdés, Héctor, E-mail: hvaldes@ucsc.cl [Laboratorio de Tecnologías Limpias (F. Ingeniería), Universidad Católica de la Santísima Concepción, Alonso de Ribera 2850, Concepción (Chile); Manéro, Marie-Hélène [Université de Toulouse (France); INPT, UPS (France); Laboratoire de Génie Chimique, 4, Allée Emile Monso, F–31030 Toulouse (France); CNRS (France); Laboratoire de Génie Chimique, F–31030 Toulouse (France); Zaror, Claudio A. [Departamento de Ingeniería Química (F. Ingeniería), Universidad de Concepción, Concepción, Correo 3, Casilla 160–C (Chile)

    2014-06-01

    Highlights: • Surface acidity of modified natural zeolite is related to its chemical reactivity. • Brønsted acid sites are associated to toluene adsorption. • Lewis acid sites could decompose ozone generating surface active oxygen species. • Infrared spectra evidence active atomic oxygen and oxidation by-product formation. • 2NH4Z1 sample shows the highest reactivity toward adsorbed toluene. - Abstract: In this study, the effect of zeolite chemical surface characteristics on the oxidative regeneration of toluene saturated-zeolite samples is investigated. A Chilean natural zeolite (53% clinoptilolite, 40% mordenite and 7% quartz) was chemically modified by acid treatment with hydrochloric acid and by ion-exchange with ammonium sulphate. Thermal pre-treatments at 623 and 823 K were applied and six zeolite samples with different chemical surface characteristics were generated. Chemical modification of natural zeolite followed by thermal out-gassing allows distinguishing the role of acidic surface sites on the regeneration of exhausted zeolites. An increase in Brønsted acid sites on zeolite surface is observed as a result of ammonium-exchange treatment followed by thermal treatment at 623 K, thus increasing the adsorption capacity toward toluene. High ozone consumption could be associated to a high content of Lewis acid sites, since these could decompose ozone into atomic active oxygen species. Then, surface oxidation reactions could take part among adsorbed toluene at Brønsted acid sites and surface atomic oxygen species, reducing the amount of adsorbed toluene after the regenerative oxidation with ozone. Experimental results show that the presence of adsorbed oxidation by-products has a negative impact on the recovery of zeolite adsorption capacity.

  1. Oxidative regeneration of toluene-saturated natural zeolite by gaseous ozone: The influence of zeolite chemical surface characteristics

    International Nuclear Information System (INIS)

    Alejandro, Serguei; Valdés, Héctor; Manéro, Marie-Hélène; Zaror, Claudio A.

    2014-01-01

    Highlights: • Surface acidity of modified natural zeolite is related to its chemical reactivity. • Brønsted acid sites are associated to toluene adsorption. • Lewis acid sites could decompose ozone generating surface active oxygen species. • Infrared spectra evidence active atomic oxygen and oxidation by-product formation. • 2NH4Z1 sample shows the highest reactivity toward adsorbed toluene. - Abstract: In this study, the effect of zeolite chemical surface characteristics on the oxidative regeneration of toluene saturated-zeolite samples is investigated. A Chilean natural zeolite (53% clinoptilolite, 40% mordenite and 7% quartz) was chemically modified by acid treatment with hydrochloric acid and by ion-exchange with ammonium sulphate. Thermal pre-treatments at 623 and 823 K were applied and six zeolite samples with different chemical surface characteristics were generated. Chemical modification of natural zeolite followed by thermal out-gassing allows distinguishing the role of acidic surface sites on the regeneration of exhausted zeolites. An increase in Brønsted acid sites on zeolite surface is observed as a result of ammonium-exchange treatment followed by thermal treatment at 623 K, thus increasing the adsorption capacity toward toluene. High ozone consumption could be associated to a high content of Lewis acid sites, since these could decompose ozone into atomic active oxygen species. Then, surface oxidation reactions could take part among adsorbed toluene at Brønsted acid sites and surface atomic oxygen species, reducing the amount of adsorbed toluene after the regenerative oxidation with ozone. Experimental results show that the presence of adsorbed oxidation by-products has a negative impact on the recovery of zeolite adsorption capacity

  2. Influence of different instrumentation modalities on the surface characteristics and biofilm formation on dental implant neck, in vitro.

    Science.gov (United States)

    Schmidt, Kristina Emily; Auschill, Thorsten Mathias; Heumann, Christian; Frankenberger, Roland; Eick, Sigrun; Sculean, Anton; Arweiler, Nicole Birgit

    2017-04-01

    To evaluate surface characteristics of implants after using different instruments and biofilm formation following instrumentation. Thirty-five commercially available dental implants were embedded into seven plastic models, attached to a phantom head and randomly assigned to seven instrumentation groups: (1) stainless steel (SSC) or (2) titanium curettes (TC); air-polisher using glycine-based (3) perio (PP) or (4) soft (SP) powders or (5) erythritol powder (EP); and an ultrasonic device using (6) stainless steel (PS) or (7) plastic-coated instruments (PI). Half of each implant neck in each group (n = 5) was treated once (30 s), while the other half was left uninstrumented (control). An eighth (8) treatment group used a bur/polisher to smooth two implants (SM). Following instrumentation implants were rinsed (5 ml Ringer's solution), analysed under a scanning electron microscope (SEM) and subjected twice (separately) to bacterial colonization with Streptococcus gordonii (2 h) and a mixed culture (S. gordonii, Actinomyces naeslundii, Fusobacterium nucleatum, Porphyromonas gingivalis and Tannerella forsythia; 24 h). Visual assessment of SEM pictures revealed surface modifications (smoothening to roughening) following instrumentation. These alterations differed between the instrument groups and from the control. Quantitative scoring of the photographs revealed that SSC caused a significantly rougher surface compared to other instruments (P  0.05) were evident between instrumented or control surfaces in either culture. Overall, no significant differences were observed in the surface characteristics (except for SSC) or bacterial colonization based on one-time instrumentation. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Investigation of the influence of pretreatment parameters on the surface characteristics of amorphous metal for use in power industry

    Science.gov (United States)

    Nieroda, Jolanta; Rybak, Andrzej; Kmita, Grzegorz; Sitarz, Maciej

    2018-05-01

    Metallic glasses are metallic materials, which exhibit an amorphous structure. These are mostly three or more component alloys, and some of them are magnetic metals. Materials of this kind are characterized by high electrical resistivity and at the same time exhibit very good magnetic properties (e.g. low-magnetization loss). The above mentioned properties are very useful in electrical engineering industry and this material is more and more popular as a substance for high-efficiency electrical devices production. This industry area is still evolving, and thus even higher efficiency of apparatus based on amorphous material is expected. A raw material must be carefully investigated and characterized before the main production process is started. Presented work contains results of complementary examination of amorphous metal Metglas 2605. Studies involve two ways to obtain clean and oxidized surface with high reactivity, namely degreasing followed by annealing process and plasma treatment. The amorphous metal parameters were examined by means of several techniques: surface free energy (SFE) measurements by sessile drop method, X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and both ex situ and in situ Raman spectroscopy. Additionally, influence of plasma parameters on wetting properties were optimized in systematic way with Design of Experiments (DOE) method. A wide range of used methods allow to fully investigate the amorphous metal material during preliminary preparation of surface. Obtained results provide information about appropriate parameters that should be applied in order to obtain highly reactive surface with functional oxide layer on it.

  4. Influence of processing parameters on the characteristics of surface layers of low temperature plasma nitrocarburized AISI 630 martensitic stainless steel

    Science.gov (United States)

    Lee, Insup

    2017-11-01

    Plasma nitrocarburizing was performed on solution-treated AISI 630 martensitic precipitation hardening stainless steel samples with a gas mixture of H2, N2, and CH4 with changing temperature, discharge voltage and amount of CH4. When nitrocarburized with increasing temperature from 380 °C to 430 °C at fixed 25% N2 and 6% CH4, the thickness of expanded martensite (α'N) layer and surface hardness increased up to 10 μm and 1323 HV0.05, respectively but the corrosion resistance decreased. Though the increase of discharge voltage from 400 V to 600 V increased α'N layer thickness and surface hardness (up to 13 μm and 1491 HV0.05, respectively), the treated samples still showed very poor corrosion behavior. Thus, to further improve the corrosion resistance, the influence of variation of the amount of CH4 in the nitrocarburizing process was investigated. Increasing the CH4 percentage aided higher corrosion resistance, although it decreased the α'N layer thickness. The most appropriate conditions for moderate α'N layer thickness, high surface hardness and better corrosion resistance than the solution-treated bare sample were established, which is plasma nitrocarburizing at 400 °C with 400 V discharge voltage and containing 25% N2 and 4% CH4.

  5. Influence of Femtosecond Laser Parameters and Environment on Surface Texture Characteristics of Metals and Non-Metals - State of the Art

    Science.gov (United States)

    Bharatish, A.; Soundarapandian, S.

    2018-04-01

    Enhancing the surface functionality by ultrashort pulsed laser texturing has received the considerable attention from researchers in the past few decades. Femtosecond lasers are widely adopted since it provides high repeatability and reproducibility by minimizing the heat affected zone (HAZ) and other collateral damages to a great extent. The present paper reports some recent studies being made worldwide on femtosecond laser surface texturing of metals, ceramics, polymers, semiconductors, thinfilms and advanced nanocomposites. It presents the state of the art knowledge in femtosecond laser surface texturing and the potential of this technology to improve properties in terms of biological, tribological and wetting performance. Since the texture quality and functionality are enhanced by the proper selection of appropriate laser parameters and ambient conditions for individual application, reporting the influence of laser parameters on surface texture characteristics assume utmost importance.

  6. The study of base and surface-active substances influence on biopharmaceutical characteristics of suppository with praziquantel

    Directory of Open Access Journals (Sweden)

    D. M. Romanina

    2016-12-01

    Full Text Available Acne dermatoses (rosacea, perioral dermatitis, seborrheic dermatitis etc. are one of the most actual problems in dermatology. Praziquantel is an antiparasitic medication effective towards trematodes, cestodes. Investigations developed by domestic scientists revealed antidemodicosis activity of praziquantel. Use of semisolid dosage forms for rectal administration will allow to increase its efficacy and minimize the risks of adverse reactions. The aim of this work is the study of influence of excipients (bases and surfactants use in suppository manufacturing on the biopharmaceutical characteristics of praziquantel rectal dosage form. Methods and results. As excipients for praziquantel rectal dosage form we have investigated suppository bases and surfactants, which are widely used in manufacturing and compounding of semisolid dosage forms and are described in literature. Suppositories were made by the fusion method. Concentration of surfactants in all compositions was 2%, praziquantel – 0,6 g on one suppository. Investigation was carried out by the 2-factors dispersive analysis with repeated observations. Suppository compounding was carried out by the suspension type. After thorough pulverization of praziquantel, it was mixed with some part of the base and then obtained mixture was added to the all melted base. As optimization parameter the praziquantel releasing was chosen as the first step of bioavailability investigation. Praziquantel releasing from suppository was studied by the equilibrium dialysis by Kruvchinsky. Ethyl alcohol was chosen as a dialysis medium considering the solubility of praziquantel. Concentration of released praziquantel after 30 minutes of the dialysis was determined by spectrophotometric analysis. Conclusion. It has been established that the sort of the base and surfactant have significant influence on praziquantel releasing from rectal suppository. It has been revealed that sort of base has the greatest influence on

  7. [The influence of autoclave sterilization on surface characteristics and cyclic fatigue resistance of 3 nickel-titanium rotary instruments].

    Science.gov (United States)

    Li, Xiang-fen; Zheng, Ping; Xu, Li; Su, Qin

    2015-12-01

    To investigate the effects of autoclave sterilization on surface characteristics and cyclic fatigue resistance of 3 types of nickel-titanium rotary instruments (K3, Mtwo, ProTaper). Three brands of NiTi rotary endodontic instruments of the same size (tip diameter 0.25 mm and constant 0.06 taper) were selected: K3, Mtwo and Protaper (F2). 24 instruments for each brand were used to evaluate the effects of autoclave sterilization on inner character in the as-received condition and after subjection to 0, 1, 5, and 10 sterilization cycles (6 for each group). Time to fracture (TtF) from the start of the test to the moment of file breakage and the length of the fractured fragment were recorded. Means and standard deviations of TtF and fragment length were calculated. The data was analyzed with SPSS13.0 software package. Another 12 NiTi rotary instruments for each brand were used, 6 subjected to 10 autoclave sterilization cycles and the other as control. Scanning electron microscope was used to observe the changes in surface topography and inner character. For cyclic fatigue resistance, when sterilization was not performed, K3 showed the highest value of TtF means and ProTaper the lowest. The differences between each brand were statistically significant (Pautoclave sterilization cycled 5 times and 10 times. The difference between 10 cycles of sterilization and the control was statistically significant (PAutoclave sterilization may increase fatigue resistance of the 3 brands. Autoclave sterilization may increase the surface roughness and inner defects in cross section.

  8. Influence of duration of phosphoric acid pre-etching on bond durability of universal adhesives and surface free-energy characteristics of enamel.

    Science.gov (United States)

    Tsujimoto, Akimasa; Barkmeier, Wayne W; Takamizawa, Toshiki; Watanabe, Hidehiko; Johnson, William W; Latta, Mark A; Miyazaki, Masashi

    2016-08-01

    The purpose of this study was to evaluate the influence of duration of phosphoric acid pre-etching on the bond durability of universal adhesives and the surface free-energy characteristics of enamel. Three universal adhesives and extracted human molars were used. Two no-pre-etching groups were prepared: ground enamel; and enamel after ultrasonic cleaning with distilled water for 30 s to remove the smear layer. Four pre-etching groups were prepared: enamel pre-etched with phosphoric acid for 3, 5, 10, and 15 s. Shear bond strength (SBS) values of universal adhesive after no thermal cycling and after 30,000 or 60,000 thermal cycles, and surface free-energy values of enamel surfaces, calculated from contact angle measurements, were determined. The specimens that had been pre-etched showed significantly higher SBS and surface free-energy values than the specimens that had not been pre-etched, regardless of the aging condition and adhesive type. The SBS and surface free-energy values did not increase for pre-etching times of longer than 3 s. There were no significant differences in SBS values and surface free-energy characteristics between the specimens with and without a smear layer. The results of this study suggest that phosphoric acid pre-etching of enamel improves the bond durability of universal adhesives and the surface free-energy characteristics of enamel, but these bonding properties do not increase for phosphoric acid pre-etching times of longer than 3 s. © 2016 Eur J Oral Sci.

  9. The influence of data characteristics on detecting wetland/stream surface-water connections in the Delmarva Peninsula, Maryland and Delaware

    Science.gov (United States)

    Vanderhoof, Melanie; Distler, Hayley; Lang, Megan W.; Alexander, Laurie C.

    2018-01-01

    The dependence of downstream waters on upstream ecosystems necessitates an improved understanding of watershed-scale hydrological interactions including connections between wetlands and streams. An evaluation of such connections is challenging when, (1) accurate and complete datasets of wetland and stream locations are often not available and (2) natural variability in surface-water extent influences the frequency and duration of wetland/stream connectivity. The Upper Choptank River watershed on the Delmarva Peninsula in eastern Maryland and Delaware is dominated by a high density of small, forested wetlands. In this analysis, wetland/stream surface water connections were quantified using multiple wetland and stream datasets, including headwater streams and depressions mapped from a lidar-derived digital elevation model. Surface-water extent was mapped across the watershed for spring 2015 using Landsat-8, Radarsat-2 and Worldview-3 imagery. The frequency of wetland/stream connections increased as a more complete and accurate stream dataset was used and surface-water extent was included, in particular when the spatial resolution of the imagery was finer (i.e., water interactions with streams during spring 2015. This translated into a range of 50–94% of the watershed contributing direct surface water runoff to streamflow. This finding suggests that our interpretation of the frequency and duration of wetland/stream connections will be influenced not only by the spatial and temporal characteristics of wetlands, streams and potential flowpaths, but also by the completeness, accuracy and resolution of input datasets.

  10. The influence of data characteristics on detecting wetland/stream surface-water connections in the Delmarva Peninsula, Maryland and Delaware

    Science.gov (United States)

    Vanderhoof, Melanie; Distler, Hayley; Lang, Megan W.; Alexander, Laurie C.

    2018-01-01

    The dependence of downstream waters on upstream ecosystems necessitates an improved understanding of watershed-scale hydrological interactions including connections between wetlands and streams. An evaluation of such connections is challenging when, (1) accurate and complete datasets of wetland and stream locations are often not available and (2) natural variability in surface-water extent influences the frequency and duration of wetland/stream connectivity. The Upper Choptank River watershed on the Delmarva Peninsula in eastern Maryland and Delaware is dominated by a high density of small, forested wetlands. In this analysis, wetland/stream surface water connections were quantified using multiple wetland and stream datasets, including headwater streams and depressions mapped from a lidar-derived digital elevation model. Surface-water extent was mapped across the watershed for spring 2015 using Landsat-8, Radarsat-2 and Worldview-3 imagery. The frequency of wetland/stream connections increased as a more complete and accurate stream dataset was used and surface-water extent was included, in particular when the spatial resolution of the imagery was finer (i.e., <10 m). Depending on the datasets used, 12–60% of wetlands by count (21–93% of wetlands by area) experienced surface-water interactions with streams during spring 2015. This translated into a range of 50–94% of the watershed contributing direct surface water runoff to streamflow. This finding suggests that our interpretation of the frequency and duration of wetland/stream connections will be influenced not only by the spatial and temporal characteristics of wetlands, streams and potential flowpaths, but also by the completeness, accuracy and resolution of input datasets.

  11. Influence of surface losses and the self-pumping effect on current-voltage characteristics of a long Josephson junction

    DEFF Research Database (Denmark)

    Pankratov, A.L.; Sobolev, A.S.; Koshelets, V.P.

    2007-01-01

    )] in the millimeter and submillimeter range. The study is performed in the frame of a modified sine-Gordon model, which includes surface losses, self-pumping effect, and in an empirical way the superconducting gap. The electromagnetic coupling to the environment is modeled by a simple resistor-capacitor load (RC load...

  12. Influence of the geologic and geomorphologic characteristics and of crab burrows on the interrelation between surface water and groundwater in an estuarine coastal wetland

    Science.gov (United States)

    Carol, Eleonora S.; Kruse, Eduardo E.; Pousa, Jorge L.

    2011-06-01

    SummaryThe interrelation between surface water and groundwater in intertidal flats is often studied through mathematical models. In many cases these models need to be supported by an integral analysis of the geologic, geomorphologic, hydrologic and biological characteristics of the environment that are to be obtained from field surveys. The marshy environment of the River Ajo in the Samborombon Bay wetland, Argentina, is a typical example of an estuarine coastal zone. Geologic and geomorphologic surveys were carried out, as well as measurements of surface water and groundwater level changes as a response of the aquifer to tidal forcing. The banks of the River Ajo are either scarped with storm flats, or mildly sloped with intertidal flats and numerous crab burrows. Sediments are mainly silty-clayey with low permeability, and lie over silty-sandy layers. At the erosion scarps the tidal wave enters the aquifer as a sub-horizontal flow through the pore space of the sediments. The tidal range in the aquifer depends on the lithological characteristics of the sediments and on the side changes of their hydraulic conductivity. The rise of the water table at high water and its subsequent fall are nearly sinusoidal, with a period similar to that of the tide at the river. At the intertidal flats, instead, the tidal wave enters the aquifer mainly as a sub-vertical flow through the crab burrows. As the crab burrows are not interconnected, they are not distinct pathways for preferential flow. Therefore, the groundwater flux into the river is very slow during low water, and the recovery of the water table takes a long time. The tidal influence upon the water table on both kinds of banks affects only a narrow strip of the aquifer. Not only are the characteristics of the marshy environment of the River Ajo representative of most of the Samborombon Bay wetland; they can also be extended to other similar coastal wetlands to help preserve these invaluable environments.

  13. SURFACE ENERGETIC CHARACTERISTICS OF ACRYLIC BIOMATERIALS

    Directory of Open Access Journals (Sweden)

    Mihaela-Papusa Vasiliu (Diaconu

    2011-09-01

    Full Text Available Introduction: Surface energetic characteristics of biomaterials influence their adherence to cells and bacteria, surface adsobtion of plasmatic proteins, as well as the capacity of such surfaces of immobilizing some biological species extremely important in medicine. Materials and method: Acrylic surfaces with an area of approximately 2 cm² were employed for the experiments: Duracryl® Plus (Spofa/Dental Product, Czechia, Duracryl® Plus covered with Palaseal (Heraeus Kulzer GmbH, Wehrheim, Germany; artificial saliva AFNOR S90-701 (pH 8.01 was used as a working solution. Results and discussion: Drops of distilled water and artificial saliva, deposited on the working materials: Duracryl and Duracryl covered with Palaseal, were photographed with an optical device, after which each drop was computer-processed, and the contact angle for each liquid surface on the surfaces of the biomaterials here under investigation was determined. On the basis of the determinations made for each material in part, the arihtmetic mean was established. Conclusions: The wettability of dental materials is wholly characterized by the values of the contact angle between the drop of biological liquid and the surface. Low values of the contact angles indicate a good wettability. The results obtained support the conclusion that the surface energy of the solid and rugosity are essential for controlling the adhesive properties of saliva unto dental materials.

  14. Polyspecies biofilm formation on implant surfaces with different surface characteristics

    Directory of Open Access Journals (Sweden)

    Patrick R. SCHMIDLIN

    2013-01-01

    Full Text Available Objective To investigate the microbial adherence and colonization of a polyspecies biofilm on 7 differently processed titanium surfaces. Material and Methods Six-species biofilms were formed anaerobically on 5-mm-diameter sterilized, saliva-preconditioned titanium discs. Material surfaces used were either machined, stained, acid-etched or sandblasted/acid-etched (SLA. Samples of the latter two materials were also provided in a chemically modified form, with increased wettability characteristics. Surface roughness and contact angles of all materials were determined. The discs were then incubated anaerobically for up to 16.5 h. Initial microbial adherence was evaluated after 20 min incubation and further colonization after 2, 4, 8, and 16.5 h using non-selective and selective culture techniques. Results at different time points were compared using ANOVA and Scheffé post hoc analysis. Results The mean differences in microorganisms colonizing after the first 20 min were in a very narrow range (4.5 to 4.8 log CFU. At up to 16.5 h, the modified SLA surface exhibited the highest values for colonization (6.9±0.2 log CFU, p<0.05 but increasing growth was observed on all test surfaces over time. Discrepancies among bacterial strains on the differently crafted titanium surfaces were very similar to those described for total log CFU. F. nucleatum was below the detection limit on all surfaces after 4 h. Conclusion Within the limitations of this in vitro study, surface roughness had a moderate influence on biofilm formation, while wettability did not seem to influence biofilm formation under the experimental conditions described. The modified SLA surface showed the highest trend for bacterial colonization.

  15. Influence of carvacrol and thymol on the physiological attributes, enterotoxin production and surface characteristics of Staphylococcus aureus strains isolated from foods

    Directory of Open Access Journals (Sweden)

    E.L. Souza

    2013-01-01

    Full Text Available This study evaluated the influence of the phenolic compounds carvacrol (CAR and thymol (THY on some physiological characteristics and on the modulation of the secretion of some staphylococcal virulence factors, that is, coagulase and enterotoxin. This study also investigated possible mechanisms for the establishment of the anti-staphylococcal activity of these compounds. Sublethal concentrations (0.3 and 0.15 µL/mL of CAR and THY inhibited the activity of the enzymes coagulase and lipase and led to a decrease in salt tolerance. At the tested sublethal concentrations, both CAR and THY led to a total suppression of enterotoxin production. The loss of a 260-nm-absorbing material and an efflux of potassium ions occurred immediately after the addition of CAR and THY at 0.6 and 1.2 µL/mL and increased up to 120 min of exposure. Electron microscopy of cells exposed to CAR and THY (0.6 µL/mL revealed that individual cells appeared to be deformed, with projections of cellular material. The observations of leakage of cellular material and an altered cell surface suggest that gross damage to a cell's cytoplasmic membrane, which results in a disruption in protein secretion, could be responsible for the anti-staphylococcal properties of CAR and THY.

  16. Surface Organization Influences Bistable Vision

    Science.gov (United States)

    Graf, Erich W.; Adams, Wendy J.

    2008-01-01

    A priority for the visual system is to construct 3-dimensional surfaces from visual primitives. Information is combined across individual cues to form a robust representation of the external world. Here, it is shown that surface completion relying on multiple visual cues influences relative dominance during binocular rivalry. The shape of a…

  17. The influence of Span-20 surfactant and micro-/nano-Chromium (Cr) Powder Mixed Electrical Discharge Machining (PMEDM) on the surface characteristics of AISI D2 hardened steel

    Science.gov (United States)

    Hosni, N. A. J.; Lajis, M. A.

    2018-04-01

    The application of powder mixed dielectric to improve the efficiency of electrical discharge machining (EDM) has been extensively studied. Therefore, PMEDM have attracted the attention of many researchers since last few decades. Improvement in EDM process has resulted in the use of span-20 surfactant and Cr powder mixed in dielectric fluid, which results in increasing machiniability, better surface quality and faster machining time. However, the study of powder suspension size of surface charateristics in EDM field is still limited. This paper presents the improvement of micro-/nano- Cr powder size on the surface characteristics of the AISI D2 hardened steels in PMEDM. It has found that the reacst layer in PMEDM improved by as high as 41-53 % compared to conventional EDM. Also notably, the combination of added Cr powder and span-20 surfactant reduced the recast layer thickness significantly especially in nano-Cr size. This improvement was great potential adding nano-size Cr powder to dielectric for machining performance.

  18. MAGELLAN SURFACE CHARACTERISTICS VECTOR DATA RECORD

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains the Magellan Surface Characteristics Vector Data Record (SCVDR) which is an orbit-by-orbit reduction of Magellan scattering and emission...

  19. Influence of various fluoride agents on working properties and surface characteristics of uncoated, rhodium coated and nitrified nickel-titanium orthodontic wires.

    Science.gov (United States)

    Katić, Višnja; Mandić, Vilko; Ježek, Damir; Baršić, Gorana; Špalj, Stjepan

    2015-05-01

    To analyze the effect of various fluoride formulations in commercially available agents on working properties of various nickel-titanium orthodontic wires. Uncoated (NiTi), rhodium coated (RhNiTi) and nitrified (NNiTi) wires were immersed to dH2O, MiPaste, Elmex and Mirafluor for 1 h. Unloading slope characteristics (average force, bending action of the force and average plateau length) and the percentage of useable constant force during unloading were observed. Surface roughness (Ra) was measured. SEM and EDS were used for observation of the surface. NiTi had decreased loading and unloading elastic modulus (E) and yield strength (YS) after immersion to MIPaste and Mirafluor. The unloading YS decreased in the RhNiTi by the MIPaste. The loading and unloading YS of the NNiTi increased in Elmex and increased average plateau force. RhNiTi showed higher average plateau length and the percentage of useful constant force during unloading in Mirafluor and the average plateau force lowered after immersion to MIPaste. The unloading slope characteristics for NiTi were affected by all three prophylactic agents, mostly by Mirafluor, and produced significantly lower forces during both loading and unloading, similarly to the NNiTi wires. The RhNiTi had the lowest forces during both loading and unloading in MIPaste. All results were at significance; pwires lose less working force when combined with Elmex. The RhNiTi improve their working properties with Mirafluor and deteriorate when combined with MiPaste.

  20. Biomimetic coating of organic polymers with a protein-functionalized layer of calcium phosphate: the surface properties of the carrier influence neither the coating characteristics nor the incorporation mechanism or release kinetics of the protein.

    Science.gov (United States)

    Wu, Gang; Liu, Yuelian; Iizuka, Tateyuki; Hunziker, Ernst B

    2010-12-01

    Polymers that are used in clinical practice as bone-defect-filling materials possess many essential qualities, such as moldability, mechanical strength and biodegradability, but they are neither osteoconductive nor osteoinductive. Osteoconductivity can be conferred by coating the material with a layer of calcium phosphate, which can be rendered osteoinductive by functionalizing it with an osteogenic agent. We wished to ascertain whether the morphological and physicochemical characteristics of unfunctionalized and bovine-serum-albumin (BSA)-functionalized calcium-phosphate coatings were influenced by the surface properties of polymeric carriers. The release kinetics of the protein were also investigated. Two sponge-like materials (Helistat® and Polyactive®) and two fibrous ones (Ethisorb™ and poly[lactic-co-glycolic acid]) were tested. The coating characteristics were evaluated using state-of-the-art methodologies. The release kinetics of BSA were monitored spectrophotometrically. The characteristics of the amorphous and the crystalline phases of the coatings were not influenced by either the surface chemistry or the surface geometry of the underlying polymer. The mechanism whereby BSA was incorporated into the crystalline layer and the rate of release of the truly incorporated depot were likewise unaffected by the nature of the polymeric carrier. Our biomimetic coating technique could be applied to either spongy or fibrous bone-defect-filling organic polymers, with a view to rendering them osteoconductive and osteoinductive.

  1. Influence of biodiesel on injection, fuel spray, and engine characteristics

    OpenAIRE

    Kegl, Breda; Pehan, Stanislav

    2012-01-01

    This paper discusses the influence of biodiesel on the injection, spray, and engine characteristics with the aim to reduce harmful emissions. The considered engine is a bus diesel engine with injection M system. The injection, fuel spray, and engine characteristics, obtained with biodiesel, are compared to those obtained with mineral diesel under peak torque and rated conditions. The considered fuel is neat biodiesel from rapeseed oil. Its density, viscosity, surface tension, and sound veloci...

  2. [Comperative study of implant surface characteristics].

    Science.gov (United States)

    Katona, Bernadett; Daróczi, Lajos; Jenei, Attila; Bakó, József; Hegedus, Csaba

    2013-12-01

    The osseointegration between the implant and its' bone environment is very important. The implants shall meet the following requirements: biocompatibility, rigidity, resistance against corrosion and technical producibility. In our present study surface morphology and material characteristics of different implants (Denti Bone Level, Denti Zirconium C, Bionika CorticaL, Straumann SLA, Straumann SLA Active, Dentsply Ankylos and Biotech Kontact implant) were investigated with scanning electron microscopy and energy-dispersive X-ray spectroscopy. The possible surface alterations caused by the manufacturing technology were also investigated. During grit-blasting the implants' surface is blasted with hard ceramic particles (titanium oxide, alumina, calcium phosphate). Properties of blasting material are critical because the osseointegration of dental implants should not be hampered. The physical and chemical features of blasting particles could importantly affect the produced surfaces of implants. Titanium surfaces with micro pits are created after immersion in mixtures of strong acids. On surfaces after dual acid-etching procedures the crosslinking between fibrin and osteogenetic cells could be enhanced therefore bone formation could be directly facilitated on the surface of the implant. Nowadays there are a number of surface modification techniques available. These can be used as a single method or in combination with each other. The effect of the two most commonly used surface modifications (acid-etching and grit-blasting) on different implants are demonstrated in our investigation.

  3. Influence Of Agriculture Undergraduates\\' Personal Characteristics ...

    African Journals Online (AJOL)

    The paper examines the influence of agriculture undergraduates\\' personal characteristics on their perception of agricultural extension. Data for the study was collected with the aid of questionnaire from 109 randomly selected respondents in the School of Agriculture and Agricultural Technology of the Federal University of ...

  4. Study on influence of Surface roughness of Ni-Al2O3 nano composite coating and evaluation of wear characteristics

    Science.gov (United States)

    Raghavendra, C. R.; Basavarajappa, S.; Sogalad, Irappa

    2018-02-01

    Electrodeposition is one of the most technologically feasible and economically superior techniques for producing metallic coating. The advancement in the application of nano particles has grabbed the attention in all fields of engineering. In this present study an attempt has been made on the Ni-Al2O3nano particle composite coating on aluminium substrate by electrodeposition process. The aluminium surface requires a specific pre-treatment for better adherence of coating. In light of this a thin zinc layer is coated on the aluminium substrate by electroless process. In addition to this surface roughness is an important parameter for any coating method and material. In this work Ni-Al2O3 composite coating were successfully coated by varying the process parameters such as bath temperature, current density and particle loading. The experimentation was performed using central composite design based 20 trials of experiments. The effect of process parameters and surface roughness before and after coating is analyzed on wear rate and coating thickness. The results shown a better wear resistance of Ni-Al2O3 composite electrodeposited coating compared to Ni coating. The particle loading and interaction effect of current density with temperature has greater significant effect on wear rate. The surface roughness is significantly affected the wear behaviour and thickness of coating.

  5. Influence of biodiesel on injection, fuel spray, and engine characteristics

    Directory of Open Access Journals (Sweden)

    Kegl Breda

    2008-01-01

    Full Text Available This paper discusses the influence of biodiesel on the injection, spray, and engine characteristics with the aim to reduce harmful emissions. The considered engine is a bus diesel engine with injection M system. The injection, fuel spray, and engine characteristics, obtained with biodiesel, are compared to those obtained with mineral diesel under peak torque and rated conditions. The considered fuel is neat biodiesel from rapeseed oil. Its density, viscosity, surface tension, and sound velocity are determined experimentally and compared to those of mineral diesel. The experimentally obtained results are used to analyze the most important injection, fuel spray, and engine characteristics. Furthermore, the influence of biodiesel usage on lubrication is presented briefly. The results indicate that, by using biodiesel, harmful emissions (NOx, CO, HC, smoke, and PM can be reduced to some extent by adjusting the injection pump timing properly while keeping other engine characteristics within acceptable limits. Furthermore, the results indicate better lubrication conditions when biodiesel is used.

  6. Anisotropic reflectance characteristics of natural Earth surfaces.

    Science.gov (United States)

    Brennan, B; Bandeen, W R

    1970-02-01

    The patterns of reflection of solar radiation from cloud, water, and land surfaces were measured with an aircraft-borne medium resolution radiometer. Reflectances in the 0.2-4.0-micro and 0.55-0.85-micro portions of the electromagnetic spectrum were investigated. Results indicate that the reflectance characteristics of most of the surface types measured are anisotropic. The anisotropy is dependent on the type of surface and the angles of incidence and reflection. In general, the anisotropy increases with increasing solar zenith angle. Clouds and forests show similar reflectance patterns, with forward and backward scattering peaks. Ocean surfaces yield a pattern similar to those of the clouds and forests but with an additional peak which is associated with sun glitter. Reflectances measured in the 0.2-4.0-micro band are generally lower than those in the 0.55-0.85-micro band under cloudy conditions. Anisotropy and spectral bandwidth should be accounted for when computing the albedo of the earth from narrow field-of-view measurements from satellites; otherwise, large errors may be expected to occur.

  7. Comparison of the influence of acoustically enhanced pulsating water jet on selected surface integrity characteristics of CW004A copper and CW614N brass

    Czech Academy of Sciences Publication Activity Database

    Lehocká, D.; Klichová, Dagmar; Foldyna, Josef; Hloch, Sergej; Hvizdoš, P.; Fides, M.; Botko, F.

    2017-01-01

    Roč. 110, November 2017 (2017), s. 230-238 ISSN 0263-2241 R&D Projects: GA MŠk(CZ) LO1406; GA MŠk ED2.1.00/03.0082 Institutional support: RVO:68145535 Keywords : pulsating water jet * surface integrity * mass material removal * copper * nanoindentation Subject RIV: JQ - Machines ; Tools Impact factor: 2.359, year: 2016 http://ac.els-cdn.com/S0263224117304396/1-s2.0-S0263224117304396-main.pdf?_tid=783a1e88-7d09-11e7-9063-00000aacb362&acdnat=1502286708_794e233dee7c309f6d1566e4775d6ff0

  8. Comparison of the influence of acoustically enhanced pulsating water jet on selected surface integrity characteristics of CW004A copper and CW614N brass

    Czech Academy of Sciences Publication Activity Database

    Lehocká, D.; Klichová, Dagmar; Foldyna, Josef; Hloch, Sergej; Hvizdoš, P.; Fides, M.; Botko, F.

    2017-01-01

    Roč. 110, November 2017 (2017), s. 230-238 ISSN 0263-2241 R&D Projects: GA MŠk(CZ) LO1406; GA MŠk ED2.1.00/03.0082 Institutional support: RVO:68145535 Keywords : pulsating water jet * surface integrity * mass material removal * copper * nanoindentation Subject RIV: JQ - Machines ; Tools OBOR OECD: Mechanical engineering Impact factor: 2.359, year: 2016 http://ac.els-cdn.com/S0263224117304396/1-s2.0-S0263224117304396-main.pdf?_tid=783a1e88-7d09-11e7-9063-00000aacb362&acdnat=1502286708_794e233dee7c309f6d1566e4775d6ff0

  9. Successful aging: early influences and contemporary characteristics.

    Science.gov (United States)

    Pruchno, Rachel A; Wilson-Genderson, Maureen; Rose, Miriam; Cartwright, Francine

    2010-12-01

    positing that successful aging has independent, yet related, dimensions that are both objective and subjective, we examine how early influences and contemporary characteristics define 4 groups of people. data were gathered from 5,688 persons aged 50-74 years living in New Jersey who participated in telephone interviews. Latent profile analysis defined people who age successfully according to both objective and subjective criteria, neither criteria, and one, but not the other, criteria. Multinomial logistic regression was used to examine the extent to which early influences and contemporary characteristics predict group membership. although characteristics observable early in life predict group membership, their influence is modified by current health behaviors and social support. The roles of education and incarceration feature prominently. Marital, work, and volunteer statuses, as well as moderate alcohol consumption, distinguish those aging successfully according to both criteria from the other 3 groups. results help to define successful aging as a multidimensional construct having both objective and subjective dimensions, provide greater clarity regarding its correlates, and increase understanding of its modifiable aspects.

  10. 10 CFR 960.5-2-8 - Surface characteristics.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Surface characteristics. 960.5-2-8 Section 960.5-2-8... Closure § 960.5-2-8 Surface characteristics. (a) Qualifying condition. The site shall be located such that, considering the surface characteristics and conditions of the site and surrounding area, including surface...

  11. Characteristics of depositional sequences, systems tracts and bounding surfaces in Early Ordovician greenhouse passive margin carbonates to Late Ordovician glacio-eustatic influenced foreland basin facies

    Energy Technology Data Exchange (ETDEWEB)

    Pope, M.C.; Read, J.F. (Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Geology)

    1994-03-01

    Passive margin, cyclic carbonates of the Early Ordovician Knox Group, Appalachians are dominated by meter scale dolomitized carbonate cycles. These are stacked into 1 to 5 m.y. depositional sequences that appear to be relatively conformable. The sequences are defined by stacking patterns on Fischer plots that graph long term changes in accommodation with thick less dolomitized cycles in the TST, and thin, highly dolomitized cycles in the HST, becoming quartzose in the late HST and LST. Sequence and systems tract boundaries are subtle and typically marked by zones of cycles rather than single discrete surfaces. In contrast, sequences in the later Ordovician foreland basin fill locally show: (1) sequence bounding unconformities on the Knox, the Camp Nelson and on top of the Ordovician, (2) well defined low stand deposits as in the subaerial breccias and detrital dolomite muds veneering the Knox unconformity; redbeds and associated quartz sands and conglomerates with intercalated peritidal carbonate layers and their distal equivalent peritidal laminites; (3) TST's in the lower part of the Middle Ordovician limestones include regionally traceable cyclic peritidal carbonates or in the lower Lexington Limestone, transgressive high energy grainstones; (4) HST's consist of poorly cyclic deeper water up into shallow water grainstone bank and northward prograding peritidal carbonate facies; The ongoing study of detailed logs of outcrop and core should help refine the understanding of the fine scale makeup of sequences developed in these contrasting tectonic and global climatic settings.

  12. Tribological influence of tool surface roughness within microforming

    DEFF Research Database (Denmark)

    Eriksen, Rasmus Solmer; Weidel, S.; Hansen, Hans Nørgaard

    2010-01-01

    A comparative friction study of tooling dies with a simple internal cylindrical geometry has been performed. The purpose of the experiment consist of studying the influence of the surface characteristics of tooling dies on the frictional behaviour in a micro bulk forming operation. This research ...

  13. Laser glass marking: influence of pulse characteristics

    Science.gov (United States)

    Rolo, Ana; Coelho, João; Pires, Margarida

    2005-09-01

    Laser glass marking is currently used in several glass materials for different purposes, such as bar codes for product tracking, brand logos or just decoration. Systems with a variety of different laser sources, with inherent power ranges, wavelengths and pulse regimes have been used, namely CO2, Nd:YAG, Excimer, Ti-Sapphire lasers. CO2 Lasers systems, although being a reliable tool for materials processing, and very compact in the case of sealed low power lasers, are usually associated with a localized thermal loading on the material, causing brittle materials like glass to crack around the irradiated area. In this experimental study a pulsed CO2 laser was used to direct marking the glass surface. The temporal characteristics of the laser pulse--pulse length, period and duty cycle were varied, and glass materials with different thermal properties were used in order to correlate the marking process--cracking or softening with or without material removal with the laser and material characteristics. Glass materials with major industrial application, such as soda-lima, borosilicate (PYREX) glasses and crystal have been investigated. Laser marked areas have been characterized in terms of surface optical properties, like diffuse and direct reflectance and transmittance for white light, directly related with marked surface quality.

  14. Surface roughness influences on the behaviour of flow inside microchannels

    Science.gov (United States)

    Farias, M. H.; Castro, C. S.; Garcia, D. A.; Henrique, J. S.

    2018-03-01

    This work discusses influence of the surface roughness on the behavior of liquids flowing inside microchannels. By measuring the flow profile using the micro-PIV technique, the flow of water inside two rectangular microchannels of different wall roughness and in a circular smooth microchannel was studied. Comparisons were made among the experimental results, showing that a metrological approach concerning surface characteristics of microdevices is required to ensure reliability of the measurements for flow analyses in microfluidic processes.

  15. Influence of rainfall and catchment characteristics on urban stormwater quality.

    Science.gov (United States)

    Liu, An; Egodawatta, Prasanna; Guan, Yuntao; Goonetilleke, Ashantha

    2013-02-01

    The accuracy and reliability of urban stormwater quality modelling outcomes are important for stormwater management decision making. The commonly adopted approach where only a limited number of factors are used to predict urban stormwater quality may not adequately represent the complexity of the quality response to a rainfall event or site-to-site differences to support efficient treatment design. This paper discusses an investigation into the influence of rainfall and catchment characteristics on urban stormwater quality in order to investigate the potential areas for errors in current stormwater quality modelling practices. It was found that the influence of rainfall characteristics on pollutant wash-off is step-wise based on specific thresholds. This means that a modelling approach where the wash-off process is predicted as a continuous function of rainfall intensity and duration is not appropriate. Additionally, other than conventional catchment characteristics, namely, land use and impervious surface fraction, other catchment characteristics such as impervious area layout, urban form and site specific characteristics have an important influence on both, pollutant build-up and wash-off processes. Finally, the use of solids as a surrogate to estimate other pollutant species was found to be inappropriate. Individually considering build-up and wash-off processes for each pollutant species should be the preferred option. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Assessment of Surface Area Characteristics of Dental Implants with Gradual Bioactive Surface Treatment

    Science.gov (United States)

    Czan, Andrej; Babík, Ondrej; Miklos, Matej; Záušková, Lucia; Mezencevová, Viktória

    2017-10-01

    Since most of the implant surface is in direct contact with bone tissue, shape and integrity of said surface has great influence on successful osseointegration. Among other characteristics that predetermine titanium of different grades of pureness as ideal biomaterial, titanium shows high mechanical strength making precise miniature machining increasingly difficult. Current titanium-based implants are often anodized due to colour coding. This anodized layer has important functional properties for right usage and also bio-compatibility of dental implants. Physical method of anodizing and usage of anodizing mediums has a significant influence on the surface quality and itself functionality. However, basic requirement of the dental implant with satisfactory properties is quality of machined surface before anodizing. Roughness, for example, is factor affecting of time length of anodizing operation and so whole productivity. The paper is focused on monitoring of surface and area characteristics, such as roughness or surface integrity after different cutting conditions of miniature machining of dental implants and their impact on suitability for creation of satisfactory anodized layer with the correct biocompatible functional properties.

  17. The Mean Curvature of the Influence Surface of Wave Equation With Sources on a Moving Surface

    Science.gov (United States)

    Farassat, F.; Farris, Mark

    1999-01-01

    The mean curvature of the influence surface of the space-time point (x, t) appears in linear supersonic propeller noise theory and in the Kirchhoff formula for a supersonic surface. Both these problems are governed by the linear wave equation with sources on a moving surface. The influence surface is also called the Sigma - surface in the aeroacoustic literature. This surface is the locus, in a frame fixed to the quiescent medium, of all the points of a radiating surface f(x, t) = 0 whose acoustic signals arrive simultaneously to an observer at position x and at the time t. Mathematically, the Sigma- surface is produced by the intersection of the characteristic conoid of the space-time point (x, t) and the moving surface. In this paper, we derive the expression for the local mean curvature of the Sigma - space of the space-time point for a moving rigid or deformable surface f(x, t) = 0. This expression is a complicated function of the geometric and kinematic parameters of the surface f(x, t) = 0. Using the results of this paper, the solution of the governing wave equation of high speed propeller noise radiation as well as the Kirchhoff formula for a supersonic surface can be written as very compact analytic expression.

  18. Surface sediment characteristics and tower karst dissolution, Guilin, southern China

    Science.gov (United States)

    Tang, Tao

    2003-01-01

    Dissolution of extensive outcrops of limestone and dolostone in humid tropical and subtropical southern China produced numerous caves and residual hills that are referred as tower karst. This study identifies and relates the physical and chemical characteristics of the surface sediment with the limestone bedrock in Guilin to assess the influence of the limestone dissolution process on sediment composition. The results of this study indicated that (i) both limestone and dolostone of the region are very pure (99.5% and 98.5% of CaCO 3 and MgCO 3, respectively); (ii) the material composition of limestone and dolostone is different from that of soil and sediment of the region: constituents of surface sediments are highly related with the clastic sedimentary rocks, such as the mudstone, but show negative correlation with limestone and dolostone; (iii) the limestone formations are highly resistant to physical weathering and disintegration; their durability versus physical weathering and their high susceptibility to chemical dissolution account for why residual towers can form and persist; (iv) a dual-zone environmental structure exists vertically downward from the surface in Guilin: the zone of unconsolidated clastic sediments that is predominantly acidic, and the zone of karstified limestone that is predominantly basic. The evidence suggests that the environment and processes differ in these two zones. The chemical dissolution of limestone that formed tower karst of the region is not mainly responsible for the accumulation of clastic sediment on the surface.

  19. Euler characteristic and quadrilaterals of normal surfaces

    Indian Academy of Sciences (India)

    In particular, if F is an oriented, closed and connected normal surface of genus g, g ≤. 7. 2. Q. DEFINITION 1.2. Let F be a normal surface in M. Let t be a normal triangle of F that lies in a tetrahedron . The triangle t is said to link a vertex v of if t separates ∂ into two disks such that the disk containing v has no other vertices of .

  20. Surface characteristics and bioactivity of a novel natural HA/Zircon nanocomposite coated on dental implants

    NARCIS (Netherlands)

    Karamian, E.; Khandan, A.; Motamedi, M.R.K.; Mirmohammadi, H.

    2014-01-01

    The surface characteristics of implant which influence the speed and strength of osseointegration include surface chemistry, crystal structure and crystallinity, roughness, strain hardening, and presence of impurities. The aim of this study was to evaluate the bioactivity and roughness of a novel

  1. Non-Destructive Analysis of Basic Surface Characteristics of Titanium Dental Implants Made by Miniature Machining

    Science.gov (United States)

    Babík, Ondrej; Czán, Andrej; Holubják, Jozef; Kameník, Roman; Pilc, Jozef

    2016-12-01

    One of the most best-known characteristic and important requirement of dental implant is made of biomaterials ability to create correct interaction between implant and human body. The most implemented material in manufacturing of dental implants is titanium of different grades of pureness. Since most of the implant surface is in direct contact with bone tissue, shape and integrity of said surface has great influence on the successful osseointegration. Among other characteristics of titanium that predetermine ideal biomaterial, it shows a high mechanical strength making precise machining miniature Increasingly difficult. The article is focused on evaluation of the resulting quality, integrity and characteristics of dental implants surface after machining.

  2. Surface energy and viscoelasticity influence caramel adhesiveness.

    Science.gov (United States)

    Wagoner, Ty B; Foegeding, Edward Allen

    2017-08-26

    Adhesion is an important textural attribute that directs consumer eating patterns and behaviors and can be a negative attribute during food processing. The objectives of this study were to modify caramel formulation and compare adhesion to different materials to quantify the influence of surface energetics and viscoelasticity on caramel adhesiveness. Mechanical adhesion was viewed in the context of pressure sensitive tack theory, where adhesion is controlled by viscoelasticity of the adhesive material and the surface energy relationship of material and probe. Caramel samples varied in total amount of fat and protein, and mechanical adhesion was measured using a series of materials with total surface energies of 39.7-53.2 mJ/m 2 . Adhesiveness decreased as fat and protein content increased, with a significant effect of total surface energy. Viscoelasticity was modeled using creep recovery data fit to a four-element Burger mechanistic model. Burger model parameters representing retarded elasticity correlated strongly with adhesiveness. The results suggest two zones of adhesion based on formulation, one driven by both surface energy relationships-most notably dispersive and total surface energy-and viscoelasticity, and the other driven solely by viscoelasticity. Relationships between mechanical properties and adhesion have been explored but are still not well understood, and could aid in the design of food products with a controlled level of adhesion. The results of this study indicate the importance of considering material surface energy when measuring mechanical adhesion or texture profile analysis. Understanding the relationships between viscoelastic behavior and adhesion can be used to make inferences on perceived texture. © 2017 Wiley Periodicals, Inc.

  3. Influence of surface roughness of a desert

    Science.gov (United States)

    Sud, Y. C.; Smith, W. E.

    1984-01-01

    A numerical simulation study, using the current GLAS climate GCM, was carried out to examine the influence of low bulk aerodynamic drag parameter in the deserts. The results illustrate the importance of yet another feedback effect of a desert on itself, that is produced by the reduction in surface roughness height of land once the vegetation dies and desert forms. Apart from affecting the moisture convergence, low bulk transport coefficients of a desert lead to enhanced longwave cooling and sinking which together reduce precipitation by Charney's (1975) mechanism. Thus, this effect, together with albedo and soil moisture influence, perpetuate a desert condition through its geophysical feedback effect. The study further suggests that man made deserts is a viable hypothesis.

  4. The Influence of Personality Characteristics on Children's Intrinsic Reading Motivation

    Science.gov (United States)

    Medford, Emma; McGeown, Sarah P.

    2012-01-01

    Research suggests that children's motivation to read is influenced by their level of reading skill and reading self-concept. However, it is possible that characteristics unrelated to reading, such as underlying personality characteristics, may also influence children's motivation to read. The current study examined the extent to which children's…

  5. Sesquinary reimpacts dominate surface characteristics on Phobos

    Science.gov (United States)

    Nayak, Michael

    2018-01-01

    We use topographic data to show that impact craters with pitted floor deposits are among the deepest on Mars. This is consistent with the interpretation of pitted materials as primary crater-fill impactite deposits emplaced during crater formation. Our database consists of 224 pitted material craters ranging in size from ˜1 to 150 km in diameter. Our measurements are based on topographic data from the Mars Orbiter Laser Altimeter (MOLA) and the High-Resolution Stereo Camera (HRSC). We have used these craters to measure the relationship between crater diameter and the initial post-formation depth. Depth was measured as maximum rim-to-floor depth, (dr), but we also report the depth measured using other definitions. The database was down-selected by refining or removing elevation measurements from "problematic" craters affected by processes and conditions that influenced their dr/D, such as pre-impact slopes/topography and later overprinting craters. We report a maximum (deepest) and mean scaling relationship of dr = (0.347±0.021)D0.537±0.017 and dr = (0.323±0.017)D0.538±0.016, respectively. Our results suggest that significant variations between previously-reported MOLA-based dr vs. D relationships may result from the inclusion of craters that: 1) are influenced by atypical processes (e.g., highly oblique impact), 2) are significantly degraded, 3) reside within high-strength regions, and 4) are transitional (partially collapsed). By taking such issues into consideration and only measuring craters with primary floor materials, we present the best estimate to date of a MOLA-based relationship of dr vs. D for the least-degraded complex craters on Mars. This can be applied to crater degradation studies and provides a useful constraint for models of complex crater formation.

  6. Assessment of hydrogeologic terrains, well-construction characteristics, groundwater hydraulics, and water-quality and microbial data for determination of surface-water-influenced groundwater supplies in West Virginia

    Science.gov (United States)

    Kozar, Mark D.; Paybins, Katherine S.

    2016-08-30

    In January 2014, a storage tank leaked, spilling a large quantity of 4-methylcyclohexane methanol into the Elk River in West Virginia and contaminating the water supply for more than 300,000 people. In response, the West Virginia Legislature passed Senate Bill 373, which requires the West Virginia Department of Health and Human Resources (WVDHHR) to assess the susceptibility and vulnerability of public surface-water-influenced groundwater supply sources (SWIGS) and surface-water intakes statewide. In response to this mandate for reassessing SWIGS statewide, the U.S. Geological Survey (USGS), in cooperation with the WVDHHR, Bureau of Public Health, Office of Environmental Health Services, compiled available data and summarized the results of previous groundwater studies to provide the WVDHHR with data that could be used as part of the process for assessing and determining SWIGS.

  7. Do leaf surface characteristics affect Agrobacterium infection in tea ...

    Indian Academy of Sciences (India)

    The host range specificity of Agrobacterium with five tea cultivars and an unrelated species (Artemisia parviflora) having extreme surface characteristics was evaluated in the present study. The degree of Agrobacterium infection in the five cultivars of tea was affected by leaf wetness, micro-morphology and surface chemistry.

  8. Dynamic characteristics of numerical systems for induction surface heating

    Science.gov (United States)

    Kozulina, T.; Blinov, K.; Galunin, S.

    2018-01-01

    This paper describes the development, investigation and optimization of induction surface heating process of a workpice taking into account its rotation by numerical simulation in a commercial package ANSYS® [1]. During the investigation it is necessary to select the optimal dynamic characteristics of the heating process in order to obtain the required temperature level and uniform temperature distribution on the surface of the workpiece.

  9. Effect of processing method on surface and weathering characteristics of wood-flour/HDPE composites

    Science.gov (United States)

    Nicole M. Stark; Laurent M. Matuana; Craig M. Clemons

    2004-01-01

    Wood-plastic lumber is promoted as a low maintenance high-durability product. When exposed to accelerated weathering, however, wood-plastic composites may experience a color change and/or loss in mechanical properties. Different methods of manufacturing wood-plastic composites lead to different surface characteristics, which can influence weathering, In this study, 50...

  10. How Friendship Network Characteristics Influence Subjective Well-Being

    Science.gov (United States)

    van der Horst, Mariska; Coffe, Hilde

    2012-01-01

    This article explores how friendship network characteristics influence subjective well-being (SWB). Using data from the 2003 General Social Survey of Canada, three components of the friendship network are differentiated: number of friends, frequency of contact, and heterogeneity of friends. We argue that these characteristics shape SWB through the…

  11. Influence of surface topography on elastically backscattered electrons

    International Nuclear Information System (INIS)

    Ding, X; Da, B; Gong, J B; Ding, Z J; Mao, S F

    2014-01-01

    A Monte Carlo simulation, taking into account of the detailed surface roughness of a realistic solid sample, has been performed to study the surface topography influence on elastic peak intensity. To describe quantitatively the surface topography effect, here we introduce surface roughness parameter (SRP) according to the ratio of elastic peak intensities between a rough surface and an ideal planar surface. Simulation results for Al sample have shown that SRP varies with surface roughness particularly at large incidence/emission angles

  12. Role of surface characteristics in urban meteorology and air quality

    Energy Technology Data Exchange (ETDEWEB)

    Sailor, David Jean [Univ. of California, Berkeley, CA (United States)

    1993-08-01

    Urbanization results in a landscape with significantly modified surface characteristics. The lower values of reflectivity to solar radiation, surface moisture availability, and vegetative cover, along with the higher values of anthropogenic heat release and surface roughness combine to result higher air temperatures in urban areas relative to their rural counterparts. Through their role in the surface energy balance and surface exchange processes, these surface characteristics are capable of modifying the local meteorology. The impacts on wind speeds, air temperatures, and mixing heights are of particular importance, as they have significant implications in terms of urban energy use and air quality. This research presents several major improvements to the meteorological modeling methodology for highly heterogeneous terrain. A land-use data-base is implemented to provide accurate specification of surface characteristic variability in simulations of the Los Angeles Basin. Several vegetation parameterizations are developed and implemented, and a method for including anthropogenic heat release into the model physics is presented. These modeling advancements are then used in a series of three-dimensional simulations which were developed to investigate the potential meteorological impact of several mitigation strategies. Results indicate that application of moderate tree-planting and urban-lightening programs in Los Angeles may produce summertime air temperature reductions on the order of 4°C with a concomitant reduction in air pollution. The analysis also reveals several mechanisms whereby the application of these mitigation strategies may potentially increase pollutant concentrations. The pollution and energy use consequences are discussed in detail.

  13. Effect of Surface Treatment on the Surface Characteristics of AISI 316L Stainless Steel

    Science.gov (United States)

    Trigwell, Steve; Selvaduray, Guna

    2005-01-01

    The ability of 316L stainless steel to maintain biocompatibility, which is dependent upon the surface characteristics, is critical to its effectiveness as an implant material. The surfaces of mechanically polished (MP), electropolished (EP) and plasma treated 316L stainless steel coupons were characterized by X-ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES) for chemical composition, Atomic Force Microscopy for surface roughness, and contact angle measurements for critical surface tension. All surfaces had a Ni concentration that was significantly lower than the bulk concentration of -43%. The Cr content of the surface was increased significantly by electropolishing. The surface roughness was also improved significantly by electropolishing. Plasma treatment had the reverse effect - the surface Cr content was decreased. It was also found that the Cr and Fe in the surface exist in both the oxide and hydroxide states, with the ratios varying according to surface treatment.

  14. Impact of the surface wind flow on precipitation characteristics over the southern Himalayas: GPM observations

    Science.gov (United States)

    Zhang, Aoqi; Fu, Yunfei; Chen, Yilun; Liu, Guosheng; Zhang, Xiangdong

    2018-04-01

    The distribution and influence of precipitation over the southern Himalayas have been investigated on regional and global scales. However, previous studies have been limited by the insufficient emphasis on the precipitation triggers or the lack of droplet size distribution (DSD) data. Here, precipitating systems were identified using Global Precipitation Mission dual-frequency radar data, and then categorized into five classes according to surface flow from the European Centre for Medium-Range Weather Forecast Interim data. The surface flow is introduced to indicate the precipitation triggers, which is validated in this study. Using case and statistical analysis, we show that the precipitating systems with different surface flow had different precipitation characteristics, including spatio-temporal features, reflectivity profile, DSD, and rainfall intensity. Furthermore, the results show that the source of the surface flow influences the intensity and DSD of precipitation. The terrain exerts different impacts on the precipitating systems of five categories, leading to various distributions of precipitation characteristics over the southern Himalayas. Our results suggest that the introduction of surface flow and DSD for precipitating systems provides insight into the complex precipitation of the southern Himalayas. The different characteristics of precipitating systems may be caused by the surface flow. Therefore, future study on the orographic precipitations should take account the impact of the surface flow and its relevant dynamic mechanism.

  15. Wetting characteristics of 3-dimensional nanostructured fractal surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Ethan, E-mail: ethan.davis4@huskers.unl.edu [Nano & Microsystems Research Laboratory, Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, W342 Nebraska Hall, Lincoln, NE 68588-0526 (United States); Liu, Ying; Jiang, Lijia; Lu, Yongfeng [Laser Assisted Nano Engineering Lab, Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, 209N Scott Engineering Center, Lincoln, NE 68588-0511 (United States); Ndao, Sidy, E-mail: sndao2@unl.edu [Nano & Microsystems Research Laboratory, Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, W342 Nebraska Hall, Lincoln, NE 68588-0526 (United States)

    2017-01-15

    Highlights: • Hierarchically structured surfaces were fabricated on the micro/nano-scale. • These structures reduced the contact angle of the inherently hydrophilic material. • Similar surfaces have applications in two-phase heat transfer and microfluidics. - Abstract: This article reports the fabrication and wetting characteristics of 3-dimensional nanostructured fractal surfaces (3DNFS). Three distinct 3DNFS surfaces, namely cubic, Romanesco broccoli, and sphereflake were fabricated using two-photon direct laser writing. Contact angle measurements were performed on the multiscale fractal surfaces to characterize their wetting properties. Average contact angles ranged from 66.8° for the smooth control surface to 0° for one of the fractal surfaces. The change in wetting behavior was attributed to modification of the interfacial surface properties due to the inclusion of 3-dimensional hierarchical fractal nanostructures. However, this behavior does not exactly obey existing surface wetting models in the literature. Potential applications for these types of surfaces in physical and biological sciences are also discussed.

  16. Influence of seawater on swelling characteristics of bentonite buffer material

    International Nuclear Information System (INIS)

    Naoi, Yutaka; Komine, Hideo; Yasuhara, Kazuya; Murakami, Satoshi; Momose, Kazuo; Sakagami, Takeharu

    2005-01-01

    A high level radioactive waste disposal facility may be built on a coastal area. Therefore, it is important to investigate the influence of seawater on bentonite buffer material. The purpose of this study is to investigate the influence of seawater on the swelling pressure and swelling deformation characteristics of five typical kinds of bentonites. This experimental work clarified the relations between the influence grade of seawater and compaction density, type of exchangeable-cation, montmorillonite content of the bentonite, and vertical pressure condition. Based on experimental results, a specification for the buffer material which can overcome the influence of seawater was defined. (author)

  17. Do leaf surface characteristics affect Agrobacterium infection in tea ...

    Indian Academy of Sciences (India)

    Unknown

    necity of Agrobacterium tumefaciens in galls of Populus L. from as single nursery; Appl. Environ. Microbiol. 53 655–659. Pandey S and Nagar P K 2002 Leaf surface wetness and mor- phological characteristics of Valeriana jatamansi grown under open and shade habitats; Biol. Planta. 45 291–294. Pandey S and Nagar P K ...

  18. Zero cycles on certain surfaces in arbitrary characteristic

    Indian Academy of Sciences (India)

    Let be a field of arbitrary characteristic. Let be a singular surface defined over with multiple rational curve singularities and suppose that the Chow group of zero cycles of its normalisation S ¯ is finite dimensional. We give numerical conditions under which the Chow group of zero cycles of is finite dimensional.

  19. Wintertime land surface characteristics in climatic simulations over ...

    Indian Academy of Sciences (India)

    Most of the surface characteristics show that major interplay between topography and western disturbances (WDs) takes place along the foothills rather than over the higher peaks of the western Himalayas. ... Present address: Hydrospheric Atmospheric Research Center (HyARC), Nagoya University, Nagoya, Japan.

  20. Surface Characteristics and Biofilm Development on Selected Dental Ceramic Materials

    Directory of Open Access Journals (Sweden)

    Kyoung H. Kim

    2017-01-01

    Full Text Available Background. Intraoral adjustment and polishing of dental ceramics often affect their surface characteristics, promoting increased roughness and consequent biofilm growth. This study correlated surface roughness to biofilm development with four commercially available ceramic materials. Methods. Four ceramic materials (Vita Enamic®, Lava™ Ultimate, Vitablocs Mark II, and Wieland Reflex® were prepared as per manufacturer instructions. Seventeen specimens of each material were adjusted and polished to simulate clinical intraoral procedures and another seventeen remained unaltered. Specimens were analysed by SEM imaging, confocal microscopy, and crystal violet assay. Results. SEM images showed more irregular surface topography in adjusted specimens than their respective controls. Surface roughness (Ra values were greater in all materials following adjustments. All adjusted materials with the exception of Vitablocs Mark II promoted significantly greater biofilm growth relative to controls. Conclusion. Simulated intraoral polishing methods resulted in greater surface roughness and increased biofilm accumulation.

  1. Development of surface wettability characteristics for enhancing pool boiling heat transfer

    International Nuclear Information System (INIS)

    Kim, Moo Hwan; Jo, Hang Jin

    2010-05-01

    For several centuries, many boiling experiments have been conducted. Based on literature survey, the characteristic of heating surface in boiling condition played as an important role which mainly influenced to boiling performance. Among many surface factor, the fact that wettability effect is significant to not only the enhancement of critical heat flux(CHF) but also the nucleate boiling heat transfer is also supported by other kinds of boiling experiments. In this regard, the excellent boiling performance (a high CHF and heat transfer performance) in pool boiling could be achieved through some favorable surface modification which satisfies the optimized wettability condition. To find the optimized boiling condition, we design the special heaters to examine how two materials, which have different wettability (e.g. hydrophilic and hydrophobic), affect the boiling phenomena. The special heaters have hydrophobic dots on hydrophilic surface. The contact angle of hydrophobic surface is 120 .deg. to water at the room temperature. The contact angle of hydrophilic surface is 60 .deg. at same conditions. To conduct the experiment with new surface condition, we developed new fabrication method and design the pool boiling experimental apparatus. Through this facility, we can the higher CHF on pattern surface than that on hydrophobic surface, and the higher boiling heat transfer performance on pattern surface than that on hydrophilic surface. Based on this experimental results, we concluded that we proposed new heating surface condition and surface fabrication method to realize the best boiling condition by modified heating surface condition

  2. Do leaf surface characteristics affect Agrobacterium infection in tea

    Indian Academy of Sciences (India)

    Caffeine fraction of tea promoted Agrobacterium infection even in leaves poor in wax (Upasi-10), whereas caffeine-free wax inhibited both Agrobacterium growth and infection. Thus, study suggests the importance of leaf surface features in influencing the Agrobacterium infection in tea leaf explants. Our study also provides a ...

  3. The impact of airport characteristics on airport surface accidents and incidents.

    Science.gov (United States)

    Wilke, Sabine; Majumdar, Arnab; Ochieng, Washington Y

    2015-06-01

    Airport surface safety and in particular runway and taxiway safety is acknowledged globally as one of aviation's greatest challenges. To improve this key area of aviation safety, it is necessary to identify and understand the causal and contributing factors on safety occurrences. While the contribution of human factors, operations, and procedures has been researched extensively, the impact of the airport and its associated characteristics itself has received little or no attention. This paper introduces a novel methodology for risk and hazard assessment of airport surface operations, and models the relationships between airport characteristics, and (a) the rate of occurrences, (b) the severity of occurrences, and (c) the causal factors underlying occurrences. The results show for the first time how the characteristics of airports, and in particular its infrastructure and operations, influence the safety of surface operations. Copyright © 2015 Elsevier Ltd. and National Safety Council. Published by Elsevier Ltd. All rights reserved.

  4. How Friendship Network Characteristics Influence Subjective Well-Being

    OpenAIRE

    van der Horst, Mariska; Coffé, Hilde

    2011-01-01

    This article explores how friendship network characteristics influence subjective well-being (SWB). Using data from the 2003 General Social Survey of Canada, three components of the friendship network are differentiated: number of friends, frequency of contact, and heterogeneity of friends. We argue that these characteristics shape SWB through the benefits they bring. Benefits considered are more social trust, less stress, better health, and more social support. Results confirm that higher fr...

  5. Human influences on streamflow drought characteristics in England and Wales

    Directory of Open Access Journals (Sweden)

    E. Tijdeman

    2018-02-01

    Full Text Available Human influences can affect streamflow drought characteristics and propagation. The question is where, when and why? To answer these questions, the impact of different human influences on streamflow droughts were assessed in England and Wales, across a broad range of climate and catchments conditions. We used a dataset consisting of catchments with near-natural flow as well as catchments for which different human influences have been indicated in the metadata (Factors Affecting Runoff of the UK National River Flow Archive (NRFA. A screening approach was applied on the streamflow records to identify human-influenced records with drought characteristics that deviated from those found for catchments with near-natural flow. Three different deviations were considered, specifically deviations in (1 the relationship between streamflow drought duration and the base flow index, BFI (specifically, BFIHOST, the BFI predicted from the hydrological properties of soils, (2 the correlation between streamflow and precipitation and (3 the temporal occurrence of streamflow droughts compared to precipitation droughts, i.e. an increase or decrease in streamflow drought months relative to precipitation drought months over the period of record. The identified deviations were then related to the indicated human influences. Results showed that the majority of catchments for which human influences were indicated did not show streamflow drought characteristics that deviated from those expected under near-natural conditions. For the catchments that did show deviating streamflow drought characteristics, prolonged streamflow drought durations were found in some of the catchments affected by groundwater abstractions. Weaker correlations between streamflow and precipitation were found for some of the catchments with reservoirs, water transfers or groundwater augmentation schemes. An increase in streamflow drought occurrence towards the end of their records was found for

  6. Human influences on streamflow drought characteristics in England and Wales

    Science.gov (United States)

    Tijdeman, Erik; Hannaford, Jamie; Stahl, Kerstin

    2018-02-01

    Human influences can affect streamflow drought characteristics and propagation. The question is where, when and why? To answer these questions, the impact of different human influences on streamflow droughts were assessed in England and Wales, across a broad range of climate and catchments conditions. We used a dataset consisting of catchments with near-natural flow as well as catchments for which different human influences have been indicated in the metadata (Factors Affecting Runoff) of the UK National River Flow Archive (NRFA). A screening approach was applied on the streamflow records to identify human-influenced records with drought characteristics that deviated from those found for catchments with near-natural flow. Three different deviations were considered, specifically deviations in (1) the relationship between streamflow drought duration and the base flow index, BFI (specifically, BFIHOST, the BFI predicted from the hydrological properties of soils), (2) the correlation between streamflow and precipitation and (3) the temporal occurrence of streamflow droughts compared to precipitation droughts, i.e. an increase or decrease in streamflow drought months relative to precipitation drought months over the period of record. The identified deviations were then related to the indicated human influences. Results showed that the majority of catchments for which human influences were indicated did not show streamflow drought characteristics that deviated from those expected under near-natural conditions. For the catchments that did show deviating streamflow drought characteristics, prolonged streamflow drought durations were found in some of the catchments affected by groundwater abstractions. Weaker correlations between streamflow and precipitation were found for some of the catchments with reservoirs, water transfers or groundwater augmentation schemes. An increase in streamflow drought occurrence towards the end of their records was found for some of the

  7. The influence of housing characteristics on leisure-time sitting

    DEFF Research Database (Denmark)

    Saidj, Madina; Jørgensen, Torben; Kart Jacobsen, Rikke

    2015-01-01

    was to examine if housing characteristics were cross-sectionally and prospectively related to leisure-time sitting in adults. METHODS: In the Danish Health2006 cohort, 2308 adults were followed for 5 years. At baseline, subjects self-reported housing characteristics (habitat type, habitat surface area...... and household size), moderate-to-vigorous physical activity (MVPA) and socio-demographic factors. Leisure-time sitting was self-reported at baseline and 5-year follow-up. Multiple linear regression was used to assess cross-sectional and prospective associations. RESULTS: At baseline habitat surface area...

  8. Mechanical properties and surface characteristics of three archwire alloys.

    Science.gov (United States)

    Krishnan, Vinod; Kumar, K Jyothindra

    2004-12-01

    Recent developments in material science have presented newer archwire materials as well as improvements in the properties of existing ones. Proper selection and understanding of the biomechanical requirement of each case requires proper characterization studies on archwire alloys. The present study characterizes and compares three orthodontic archwire alloys, stainless steel, beta titanium alloy (TMA), and a newly introduced titanium alloy (TiMolium), for the parameters (1) ultimate tensile strength (UTS), 0.02% offset yield strength (YS), and modulus of elasticity (E); (2) load deflection characteristics; (3) frictional properties; (4) surface characteristics and (5) elemental analysis for TiMolium. Seven specimens of each archwire alloy were used for evaluating each parameter. An instron universal testing machine was used for tensile testing, three-point bend testing, and evaluation of frictional characteristics. Scanning electron microscope was used for surface evaluation and X-ray fluorescence for elemental analysis of TiMolium wire specimens. Stainless steel was the strongest archwire alloy with high UTS, E, 0.02% offset YS, and less friction at the archwire-bracket interface. TMA wires exhibited better load deflection characteristics with less stiffness than the other two wires. The surface of TMA appeared rough and exhibited very high values for friction at the archwire-bracket interface. TiMolium appeared to be an alpha-beta titanium alloy composed of titanium, aluminum, and vanadium and intermediate in nature for all the parameters evaluated.

  9. Extracting sea ice surface characteristics using spectral unmixing

    Science.gov (United States)

    Barrett, A.; Stroeve, J.

    2016-12-01

    The surface of the Arctic Ocean is a mixture of bare sea ice, snow covered sea ice, melt ponds, leads and open ocean. The composition of this mixture changes throughout the summer melt season. The mixture of surface types influences albedo at a range of scales, from local to global. The spatial variability of surface types often occurs at a scale smaller than the spatial resolution of remotely sensed imagery, resulting in a "mixed-pixel" problem. Therefore, it is important to quantify the fractions of surface types in each pixel. Multiple endmember spectral mixture analysis (MESMA) allows fractional area of surface types to be estimated. In this paper we explore classifying RS imagery collected over the Arctic Ocean into surface types using a spectral mixture analysis. MESMA is only as good as the endmembers. We use a library of spectra collected in-situ at Barrow, Resolute and the Surface Heat Budget of the Arctic Ocean over bare and snow covered sea ice, melt ponds, and leads as our endmembers. The separability of spectra is first examined. For the spectral unmixing, we follow a similar approach to the MEM/MODSCAG algorithm for snow covered area. Endmember spectra for each of the four surface types are selected to find the best linear combination of spectra. The algorithm is tested on MODIS imagery for selected dates throughout the 2007 melt season. The approach is validated using high-resolution Quickbird imagery collected at the same time as the MODIS images.

  10. Microscopic Study of Surface Microtopographic Characteristics of Dental Implants

    Science.gov (United States)

    Sezin, M.; Croharé, L.; Ibañez, J.C.

    2016-01-01

    Objective: To determine and compare the micro topographic characteristics of dental implants submitted to different surface treatments, using scanning electron microscopy (SEM). Materials and Methods: Implants were divided into 7 groups of 3 specimens each, according to the surface treatment used: group 1: Osseotite, BIOMET 3i; group 2: SLA surface, Institut Straumann AG; group 3: Oxalife surface, Tree-Oss implant; group 4: B&W implant surface; group 5: Q-implant surface; group 6: ML implant surface; group 7: RBM surface, Rosterdent implant. The surfaces were examined under SEM (Carl Zeiss FE-SEM-SIGMA). Image Proplus software was used to determine the number and mean diameter of pores per area unit (mm). The data obtained were analyzed with the Mann-Whitney test. A confocal laser microscope (LEXT-OLS4100 Olympus) was used to conduct the comparative study of surface roughness (Ra). Data were analyzed using Tukey's HSD test. Results: The largest average pore diameter calculated in microns was found in group 5 (3.45 µm+/-1.91) while the smallest in group 7 (1.47µm+/-1.29). Significant differences were observed among each one of the groups studied (p<0.05). The largest number of pores/mm2 was found in group 2 (229343) and the smallest number in group 4 (10937). Group 2 showed significant differences regarding the other groups (p<0.05). The greatest roughness (Ra) was observed in group 2 (0.975µm+/-0.115) and the smallest in group 4 (0.304µm+/-0.063). Group 2 was significantly different from the other groups (p<0.05). Conclusion: The micro topography observed in the different groups presented dissimilar and specific features, depending on the chemical treatment used for the surfaces.. PMID:27335615

  11. Reflection characteristics of a composite planar AMC surface

    Directory of Open Access Journals (Sweden)

    Ruey-Bing Hwang

    2012-03-01

    Full Text Available This study investigates the reflection characteristics of a composite Artificial Magnetic Conductor (AMC surface consisting of multiple orthogonal gradient AMC surfaces arranged in a two-dimensional periodic pattern. The gradient AMC surface in this study consists of square metal patches of variable size printed on a grounded dielectric substrate. Due to the orthogonal placement of the gradient AMC surface, the incident energy of a plane wave normally incident on the composite AMC surface will be reflected into four major lobes away from the impinging direction. To achieve a systematical design, a simple formula based on array antenna theory was developed to determine the reflection pattern of the gradient AMC surface illuminated by a normal incident plane wave. A time-domain full-wave simulation was also carried out to calculate the electromagnetic fields in the structure and the far-field patterns. The scattering patterns of the structure were measured in an electromagnetic anechoic chamber. Results confirm the design principle and procedures in this research. Since such a composite AMC surface can be easily fabricated using the standard printed circuit board technique without via-hole process, it may have potential applications in beam-steering and radar cross section reduction.

  12. Influence of mulch on agronomic characteristics and disease ...

    African Journals Online (AJOL)

    Influence of mulch on agronomic characteristics and disease incidence in spinach (Spinacia oleraceae L.) EM Ossom, DW Mngometulu. Abstract. No Abstract. Uniswa Research Journal of Agriculture, Science and Technology Vol. 9 (1) 2006: pp. 77-84. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL ...

  13. The influence of personality characteristics and gender on ...

    African Journals Online (AJOL)

    This study investigated the influence of personality characteristics and gender on Organizational Citizenship Behaviour (OCB). One hundred and fifty (150) respondents comprising eighty (80) males and seventy (70) females were randomly drawn from the Ministries of Finance, Health, Lands and Survey; State Government ...

  14. Influence of hydrophobic characteristic of organo-modified precursor ...

    Indian Academy of Sciences (India)

    Influence of hydrophobic characteristic of organo-modified precursor on wettability of silica film ... 202, 6th district, P.O. Box 35-174, 060021 Bucharest, Romania; Faculty of Physics, University of Bucharest, 3Nano-SAE Research Centre, P.O. Box MG-38, 077125 Bucharest-Magurele, Romania; Faculty of Chemistry, ...

  15. Direction of travel can influence canine gait characteristics

    DEFF Research Database (Denmark)

    Miles, James Edward; Vitger, Anne Désiré; Poulsen, Helle Harding

    . Statement Direction of travel may influence gait characteristics and thereby both determination of local reference intervals and discriminatory ability between normal and abnormal limbs. Consistent walkway room setup and use of multiple passes in both directions appear sensible in order to minimise error...

  16. Influence of growth stage at harvest on fermentative characteristics ...

    African Journals Online (AJOL)

    An experiment was conducted to investigate the influence of stage of growth at harvest on fermentative characteristics of Panicum maximum silage. The treatments were three different growth stages (early vegetative, boot and full bloom stage) that were ensiled directly or wilted prior to ensiling. Directly ensiled and wilted ...

  17. Socio-economic characteristics of small-holder farmers influencing ...

    African Journals Online (AJOL)

    Socio-economic characteristics of small-holder farmers influencing their utilisation of microcredit in the central agricultural zone of Cross River state. ... The findings revealed that about thirty – four percent (33.6%) of the crop farmers fell between 41-50 years while about 51% of the livestock farmers fell between 31-40 years.

  18. Influence of hydrophobic characteristic of organo-modified precursor ...

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... Influence of hydrophobic characteristic of organo-modified precursor on wettability of silica film ... 202, 6th district, P.O. Box 35-174, 060021 Bucharest, Romania; Faculty of Physics, University of Bucharest, 3Nano-SAE Research Centre, P.O. Box MG-38, 077125 Bucharest-Magurele, Romania; Faculty of ...

  19. Characteristics and factors influencing fast food intake of young ...

    African Journals Online (AJOL)

    2010-03-13

    Mar 13, 2010 ... Original Research: Characteristics and factors influencing fast food intake of young adult consumers. 2010;23(3) ... intake were identified that provide health educators and policy makers with useful information for health promotion. ... malls were selected on the basis of a previous market research study.

  20. Influence of water and soil characteristics on abundance of ...

    African Journals Online (AJOL)

    Influence of water and soil characteristics on abundance of chlorophyll 'A\\' in Elechi creek, Niger Delta, Nigeria. UU Gabriel, MB Inko-Tariah, NO Olu, OA Akinrotimi. Abstract. No Abstract. International Journal of Natural and Applied Sciences Vol. 4 (3) 2008: pp. 174-180. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT

  1. Engineering Influence of compaction delay on some characteristics ...

    African Journals Online (AJOL)

    Engineering Influence of compaction delay on some characteristics of lateritic soils stabilized with. F. F. UDOEYO, M. A. ABUBAKAR. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/gjpas.v7i4.16313 · AJOL African Journals Online. HOW TO ...

  2. Influence of Socio-Economic Characteristics of Yam Sellers on ...

    African Journals Online (AJOL)

    The study investigated the influence of demographic characteristics of yam wholesalers on the marketing margin of yam in Delta State. Data were collected from 80 randomly selected wholesale marketers of yam from 10 markets in 2 LGAs of the state. Findings show that wholesale market of yam is dominated by males ...

  3. Influence of Personal Characteristics on Job Performance Among ...

    African Journals Online (AJOL)

    This paper examined the influence of personal characteristics of extension agents and researchers on their job performance. The results indicate that extension agents had a mean of 36. 5 years with majority being male and married as well as having HND certificates. They have also spent between 21 and 30 years in ...

  4. Nanoscale topography influences polymer surface diffusion.

    Science.gov (United States)

    Wang, Dapeng; He, Chunlin; Stoykovich, Mark P; Schwartz, Daniel K

    2015-02-24

    Using high-throughput single-molecule tracking, we studied the diffusion of poly(ethylene glycol) chains at the interface between water and a hydrophobic surface patterned with an array of hexagonally arranged nanopillars. Polymer molecules displayed anomalous diffusion; in particular, they exhibited intermittent motion (i.e., immobilization and "hopping") suggestive of continuous-time random walk (CTRW) behavior associated with desorption-mediated surface diffusion. The statistics of the molecular trajectories changed systematically on surfaces with pillars of increasing height, exhibiting motion that was increasingly subdiffusive and with longer waiting times between diffusive steps. The trajectories were well-described by kinetic Monte Carlo simulations of CTRW motion in the presence of randomly distributed permeable obstacles, where the permeability (the main undetermined parameter) was conceptually related to the obstacle height. These findings provide new insights into the mechanisms of interfacial transport in the presence of obstacles and on nanotopographically patterned surfaces.

  5. Evaluation of Cellulosic Fabrics Surface Characteristics after Different Treatments

    OpenAIRE

    Vitalija MASTEIKAITĖ; Ulzan SMAILOVA; Maira NURZHASAROVA; Virginija SACEVIČIENĖ; Tadas KLEVECKAS

    2014-01-01

    Various clothes treatments during their manufacture and wear change the fabrics physical and surface characteristics. The different testing methods for fabrics quality evaluation are used in this research. The aim of this work is to examine the effect of enzyme treatment, laundering and abrasion on the appearance of different cellulosic fabrics. Six cotton and cotton blend woven fabrics used for faded garments production were chosen for this examination. Treatments such, as enzyme wash, domes...

  6. Characteristics of surface signatures of Mediterranean water eddies

    Science.gov (United States)

    Bashmachnikov, I.; Carton, X.; Belonenko, T. V.

    2014-10-01

    In this work, we obtain new results on the manifestation of meddies (or of other deep eddies) at the sea-surface, further developing the results by Bashmachnikov and Carton (2012). The quasi-geostrophic equations are used to describe a near-axisymmetric vortex in the upper ocean, forced at its lower boundary by the isopycnal elevation of a moving meddy. The solution thus obtained provides a better approximation of the characteristics of meddy surface signals. The results show that in subtropics large meddies with dynamic radius Rm ≥ 30 km are always seen at the sea-surface with AVISO altimetry, that medium-size meddies with Rm = 20 km may be seen at the sea-surface only if they are sufficiently shallow and strong, while small meddies with Rm = 10 km generally cannot be detected with the present accuracy of altimetry data. The intensity of meddy surface signals decreases to the south with the decrease of the f/N ratio. The seasonal variation in intensity of the surface signal for northern meddies (45°N) is on the order of 2-3 cm, but for subtropical meddies (35°N) it can be on the order of 5-10 cm. The radii of meddy surface signals range from 1 to 2 times the radii of the corresponding meddies. For most of the observed subtropical meddies, the upper limit should be used. Numerical experiments show that surface signals of meddies translated with β-drift are efficiently dispersed by the radiation of Rossby waves. At the same time, for meddies translated by a background current, the surface signal does not show strong dissipation.

  7. Characteristics of Turbulent Airflow Deduced from Rapid Surface Thermal Fluctuations: An Infrared Surface Anemometer

    Science.gov (United States)

    Aminzadeh, Milad; Breitenstein, Daniel; Or, Dani

    2017-12-01

    The intermittent nature of turbulent airflow interacting with the surface is readily observable in fluctuations of the surface temperature resulting from the thermal imprints of eddies sweeping the surface. Rapid infrared thermography has recently been used to quantify characteristics of the near-surface turbulent airflow interacting with the evaporating surfaces. We aim to extend this technique by using single-point rapid infrared measurements to quantify properties of a turbulent flow, including surface exchange processes, with a view towards the development of an infrared surface anemometer. The parameters for the surface-eddy renewal (α and β ) are inferred from infrared measurements of a single-point on the surface of a heat plate placed in a wind tunnel with prescribed wind speeds and constant mean temperatures of the surface. Thermally-deduced parameters are in agreement with values obtained from standard three-dimensional ultrasonic anemometer measurements close to the plate surface (e.g., α = 3 and β = 1/26 (ms)^{-1} for the infrared, and α = 3 and β = 1/19 (ms)^{-1} for the sonic-anemometer measurements). The infrared-based turbulence parameters provide new insights into the role of surface temperature and buoyancy on the inherent characteristics of interacting eddies. The link between the eddy-spectrum shape parameter α and the infrared window size representing the infrared field of view is investigated. The results resemble the effect of the sampling height above the ground in sonic anemometer measurements, which enables the detection of larger eddies with higher values of α . The physical basis and tests of the proposed method support the potential for remote quantification of the near-surface momentum field, as well as scalar-flux measurements in the immediate vicinity of the surface.

  8. Relationship between enamel bond fatigue durability and surface free-energy characteristics with universal adhesives.

    Science.gov (United States)

    Nagura, Yuko; Tsujimoto, Akimasa; Barkmeier, Wayne W; Watanabe, Hidehiko; Johnson, William W; Takamizawa, Toshiki; Latta, Mark A; Miyazaki, Masashi

    2018-04-01

    The relationship between enamel bond fatigue durability and surface free-energy characteristics with universal adhesives was investigated. The initial shear bond strengths and shear fatigue strengths of five universal adhesives to enamel were determined with and without phosphoric acid pre-etching. The surface free-energy characteristics of adhesive-treated enamel with and without pre-etching were also determined. The initial shear bond strength and shear fatigue strength of universal adhesive to pre-etched enamel were higher than those to ground enamel. The initial shear bond strength and shear fatigue strength of universal adhesive to pre-etched enamel were material dependent, unlike those to ground enamel. The surface free-energy of the solid (γ S ) and the hydrogen-bonding force (γSh) of universal adhesive-treated enamel were different depending on the adhesive, regardless of the presence or absence of pre-etching. The bond fatigue durability of universal adhesives was higher to pre-etched enamel than to ground enamel. In addition, the bond fatigue durability to pre-etched enamel was material dependent, unlike that to ground enamel. The surface free-energy characteristics of universal adhesive-treated enamel were influenced by the adhesive type, regardless of the presence or absence of pre-etching. The surface free-energy characteristics of universal adhesive-treated enamel were related to the results of the bond fatigue durability. © 2018 Eur J Oral Sci.

  9. [Surface physicochemical and fractal characteristics of sediments in desilting basin from Yellow River diversion reservoir].

    Science.gov (United States)

    Hu, Kang-Bo; Wang, Yi-Li; Li, Jun-Qing; Gui, Ping; Jiang, Yan-Ling

    2011-07-01

    Surface morphology and pore surface fractal characteristics of the sediment in the desilting basin of Queshan Reservoir were studied. Six sediment samples were collected and particle size, morphology, pore structure and fractal characteristics, surface elements distribution were analyzed as well. The objectives of this study were to investigate the reason for the differences among the pore surface fractal dimensions and fractal scales on the basis of different models, and discuss the effect of surface morphology of these sediment particles on their surface elements distribution. The results showed that these sediment particles with average diameter of 18-83 microm were mainly composed of clay, silt and fine sand. Their complex surface morphology and pore size distribution were reflected by wide range of the BET surface area (8.248-31.60 m2/g), average pore diameter (3.977-7.850 nm) and pore-size distribution (1.870-60.78 nm). Although the pore surface fractal dimensions (D(s)), based on fractal FHH or thermodynamic models, were 2.67-2.89, and their fractal scales generally ranged from several nanometers to tens of nanometers, the differences were still observed in D(s) values calculated from above two models because of inhomogeneity in surface pore size distribution. Therefore, the D(s) based on pore-size distribution were 2.12-2.60, these values close to D(s) calculated from fractal FHH models revealed that pore-size distribution could contribute significantly to D(s) calculation. In addition, the heterogeneous surface adsorption sites of these sediment particles caused by much complex surface morphology had strong influence on the each element distribution on the particle surface.

  10. Influence of the surface finishing on ultrasound velocity in wood

    Directory of Open Access Journals (Sweden)

    Tomáš Špaček

    2008-01-01

    Full Text Available Non-destructive diagnostic methods are very useful for monumental buildings. This paper deals with one of these technique, namely with ultrasound testing and influence of surface finishing on ultrasound velocity measured by means of device the Arborsonic Decay Detector. Surface finishing (Primalex – thick synthetic film of the surface finishing, Luxol – Extra – thin synthetic film of the surface finishing and Impranal Profi SL – thick acryl film the surface finishing were selected and tested in this research. The transmittion time was measured and velocity was converted from it. This was compared before and after application of surface finishing.

  11. The Influence of Top Management Team Characteristics on BPD Performance

    Directory of Open Access Journals (Sweden)

    Joy Elly Tulung

    2015-12-01

    Full Text Available Based on ”upper echelons theory”, this paper investigates the relation between top management team composition and BPD performance. For top management team characteristics, we employ age, level of education, background of education, gender, and functional background, while for measured the BPD performance we employ return on asset (ROA, return on equity (ROE, capital adequacy ratio (CAR, net interest margin (NIM, loan to deposit ratio (LDR, non-performing loan (NPL and operation expenses to operation income (BOPO. The results show that all characteristics have positive significant influences on BPD performance.

  12. Evaluation of Cellulosic Fabrics Surface Characteristics after Different Treatments

    Directory of Open Access Journals (Sweden)

    Vitalija MASTEIKAITĖ

    2014-09-01

    Full Text Available Various clothes treatments during their manufacture and wear change the fabrics physical and surface characteristics. The different testing methods for fabrics quality evaluation are used in this research. The aim of this work is to examine the effect of enzyme treatment, laundering and abrasion on the appearance of different cellulosic fabrics. Six cotton and cotton blend woven fabrics used for faded garments production were chosen for this examination. Treatments such, as enzyme wash, domestic laundering, abrasion using IT-2 and Martindale (Mesdan instruments and rubbing were applied in order to evaluate the worn look of the different fabrics. The degree of fabrics distortion was determined by using abrasion resistance and weight change characteristics. Also, the colour fastness and staining after different dry and wet treatments were analysed. The results of this research show that the surface characteristics of cellulosic fabrics depend on the properties of the fabrics and the type of treatment. Most of the tested cellulosic fabrics have changed their difference in colour not only after the enzyme wash but also after successive abrading and cyclical domestic launderings. Both colour fading of the fabrics and staining of cotton white fabric may appear after rubbing in dry and especially in wet conditions. The received results show that during tested fabrics laundering, the cotton and nylon parts of multifibre fabric were stained more heavily. DOI: http://dx.doi.org/10.5755/j01.ms.20.3.4331

  13. Development of Fractal Dimension and Characteristic Roughness Models for Turned Surface of Carbon Steels

    Science.gov (United States)

    Zuo, Xue; Zhu, Hua; Zhou, Yuankai; Ding, Cong; Sun, Guodong

    2016-08-01

    Relationships between material hardness, turning parameters (spindle speed and feed rate) and surface parameters (surface roughness Ra, fractal dimension D and characteristic roughness τ∗) are studied and modeled using response surface methodology (RSM). The experiments are carried out on a CNC lathe for six carbon steel material AISI 1010, AISI 1020, AISI 1030, AISI 1045, AISI 1050 and AISI 1060. The profile of turned surface and the surface roughness value are measured by a JB-5C profilometer. Based on the profile data, D and τ∗ are computed through the root-mean-square method. The analysis of variance (ANOVA) reveals that spindle speed is the most significant factors affecting Ra, while material hardness is the most dominant parameter affecting τ∗. Material hardness and spindle speed have the same influence on D. Feed rate has less effect on three surface parameters than spindle speed and material hardness. The second-order models of RSM are established for estimating Ra, D and τ∗. The validity of the developed models is approximately 80%. The response surfaces show that a surface with small Ra and large D and τ∗ can be obtained by selecting a high speed and a large hardness material. According to the established models, Ra, D and τ∗ of six carbon steels surfaces can be predicted under cutting conditions studied in this paper. The results have an instructive meaning to estimate the surface quality before turning.

  14. Experimental Study on Influence of Distribution Line Support System on Flashover Characteristics

    Science.gov (United States)

    Sekioka, Shozo; Hayashi, Tomoyuki; Miyazaki, Teru; Sakamoto, Yoshiki; Okabe, Shigemitsu

    This paper describes experimental results of flashover characteristics of medium-voltage insulators to support an insulated cable which is used in Japanese power distribution lines. The experimental study is targeted for direct lightning strokes to a shielding wire or top of a reinforced concrete pole in the distribution line. Lightning impulse voltage is applied to a metallic cross arm to represent the direct lightning stroke. 50% flashover voltage, voltage vs. flashover time characteristic and a photograph of the discharge are measured. This paper investigates the flashover characteristics of three types of cable support system such as suspension support, dead-end support and strain support. The flashover characteristics are dependent on the supporting system. Surface discharge on the insulated cable due to the flashover is observed, causes the discrepancy of the flashover characteristics. This paper presents constants in the integration method, which is a flashover model and can consider the influence of applied voltage waveform in order for accurate lightning surge analysis.

  15. Impact of cranberry on Escherichia coli cellular surface characteristics

    International Nuclear Information System (INIS)

    Johnson, Brandy J.; Lin Baochuan; Dinderman, Michael A.; Rubin, Robert A.; Malanoski, Anthony P.; Ligler, Frances S.

    2008-01-01

    The anti-adhesive effects of cranberry have been attributed to both interactions of its components with the surface of bacterial cells and to inhibition of p-fimbriae expression. Previous reports also suggested that the presence of cranberry juice changed the Gram stain characteristics of Escherichia coli. Here, we show that the morphology of E. coli is changed when grown in the presence of juice or extract from Vaccinium macrocarpon (cranberry). Gene expression analysis indicates the down regulation of flagellar basal body rod and motor proteins. Consistent with this finding and previous reports, the SEM images indicate a decrease in the visible p-fimbriae. The iodine used in Gram-staining protocols was found to interact differently with the bacterial membrane when cells were cultured in spiked media. Slight alterations in the Gram stain protocol demonstrated that culturing in the presence of cranberry juice does not change the Gram stain characteristics contradicting other reports.

  16. Surface wave propagation characteristics in atmospheric pressure plasma column

    International Nuclear Information System (INIS)

    Pencheva, M; Benova, E; Zhelyazkov, I

    2007-01-01

    In the typical experiments of surface wave sustained plasma columns at atmospheric pressure the ratio of collision to wave frequency (ν/ω) is much greater than unity. Therefore, one might expect that the usual analysis of the wave dispersion relation, performed under the assumption ν/ω = 0, cannot give adequate description of the wave propagation characteristics. In order to study these characteristics we have analyzed the wave dispersion relationship for arbitrary ν/ω. Our analysis includes phase and wave dispersion curves, attenuation coefficient, and wave phase and group velocities. The numerical results show that a turning back point appears in the phase diagram, after which a region of backward wave propagation exists. The experimentally observed plasma column is only in a region where wave propagation coefficient is higher than the attenuation coefficient. At the plasma column end the electron density is much higher than that corresponding to the turning back point and the resonance

  17. Surface characteristics and in vitro biocompatibility of a manganese-containing titanium oxide surface

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jin-Woo, E-mail: jinwoo@knu.ac.kr [Department of Periodontology, School of Dentistry, Kyungpook National University, 188-1, Samduk 2Ga, Jung-Gu, Daegu 700-412 (Korea, Republic of); Kim, Youn-Jeong; Jang, Je-Hee [Department of Periodontology, School of Dentistry, Kyungpook National University, 188-1, Samduk 2Ga, Jung-Gu, Daegu 700-412 (Korea, Republic of)

    2011-11-01

    This study investigated the surface characteristics and in vitro biocompatibility of a titanium (Ti) oxide layer incorporating the manganese ions (Mn) obtained by hydrothermal treatment with the expectation of utilizing potent integrin-ligand binding enhancement effect of Mn for future applications as an endosseous implant surface. The surface characteristics were evaluated by scanning electron microscopy, thin-film X-ray diffractometry, X-ray photoelectron spectroscopy, optical profilometry and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The in vitro biocompatibility of the Mn-containing Ti oxide surface was evaluated in comparison with untreated bare Ti using a mouse calvaria-derived osteoblastic cell line (MC3T3-E1). The hydrothermal treatment produced a nanostructured Mn-incorporated Ti oxide layer approximately 0.6 {mu}m thick. ICP-AES analysis demonstrated that the Mn ions were released from the hydrothermally treated surface into the solution. Mn incorporation notably decreased cellular attachment, spreading, proliferation, alkaline phosphatase activity, and osteoblast phenotype gene expression compared with the bare Ti surface (p < 0.05). The results indicate that the Mn-incorporation into the surface Ti oxide layer has no evident beneficial effects on osteoblastic cell function, but instead, actually impaired cell behavior.

  18. Effect of surface roughness variation on the transmission characteristics of D-shaped fibers with ambient index change

    International Nuclear Information System (INIS)

    Kim, Hyun-Joo; Kwon, Oh-Jang; Han, Young-Geun

    2010-01-01

    The influence of surface roughness on the sensitivity of D-shaped fibers to changes in the ambient index was investigated. In order to obtain D-shaped fibers with different surface roughness, we polished one side of the fibers by using different abrasive grits. The topographies of the surfaces of the polished D-shaped fibers were then observed by using atomic force microscopy (AFM). The light scattered from the rough surfaces of the D-shaped fibers was measured by using optical microscopy. The effect of an ambient index change on the transmission characteristics of D-shaped fibers was measured for various values of the surface roughness. The experimental results indicate that variations in the surface roughness have a considerable influence on the sensitivity of the transmission characteristics of D-shaped fibers to changes in the ambient index.

  19. Influence of surface topography on friction, film breakdown and running-in in the mixed lubrication regime

    NARCIS (Netherlands)

    Lugt, Pieter Martin; Severt, R.W.M.; Fogelström, J.; Tripp, J.H.

    2001-01-01

    The influence of surface topography on the lubricant film build-up ability and the friction characteristics of potential rolling bearing surfaces has been investigated by experiments on two-disc rigs. Traction-friction torque measurements were made for a variety of surface combinations, together

  20. Factors influencing graphene growth on metal surfaces

    International Nuclear Information System (INIS)

    Loginova, E; Bartelt, N C; McCarty, K F; Feibelman, P J

    2009-01-01

    Graphene forms from a relatively dense, tightly bound C-adatom gas when elemental C is deposited on or segregates to the Ru(0001) surface. Nonlinearity of the graphene growth rate with C-adatom density suggests that growth proceeds by addition of C atom clusters to the graphene edge. The generality of this picture has now been studied by use of low-energy electron microscopy (LEEM) to observe graphene formation when Ru(0001) and Ir(111) surfaces are exposed to ethylene. The finding that graphene growth velocities and nucleation rates on Ru have precisely the same dependence on adatom concentration as for elemental C deposition implies that hydrocarbon decomposition only affects graphene growth through the rate of adatom formation. For ethylene, that rate decreases with increasing adatom concentration and graphene coverage. Initially, graphene growth on Ir(111) is like that on Ru: the growth velocity is the same nonlinear function of adatom concentration (albeit with much smaller equilibrium adatom concentrations, as we explain with DFT calculations of adatom formation energies). In the later stages of growth, graphene crystals that are rotated relative to the initial nuclei nucleate and grow. The rotated nuclei grow much faster. This difference suggests firstly, that the edge-orientation of the graphene sheets relative to the substrate plays an important role in the growth mechanism, and secondly, that attachment of the clusters to the graphene is the slowest step in cluster addition, rather than formation of clusters on the terraces.

  1. Do Neighborhood Characteristics in Amsterdam Influence Adiposity at Preschool Age?

    Science.gov (United States)

    Hrudey, E. Jessica; Kunst, Anton E.; Stronks, Karien; Vrijkotte, Tanja G.M.

    2015-01-01

    Background: Neighborhood characteristics may contribute to adiposity in young children, but results in the current literature are inconsistent. This study aimed to investigate whether objective (socioeconomic status (SES)) and subjective (perceived safety, satisfaction with green spaces and perceived physical disorder) neighborhood characteristics directly influence child adiposity (as measured by BMI, percent body fat (%BF) and waist-to-height ratio (WHtR)). Methods: Data on child BMI, %BF and WHtR were obtained from the Amsterdam Born Children and their Development cohort at 5–6 years of age. Three thousand four hundred and sixty nine (3469) children were included in the analyses. Mixed models, using random intercepts for postal code area to account for neighborhood clustering effects, were used to analyze the relationships of interest. Results: Associations were observed for both perceived safety and neighborhood SES with %BF after adjustment for maternal education and ethnicity. All relationships were eliminated with the inclusion of individual covariates and parental BMI into the models. Conclusions: In general, child adiposity at age 5–6 years was not independently associated with neighborhood characteristics, although a small relationship between child %BF and both neighborhood SES and perceived safety cannot be ruled out. At this young age, familial and individual factors probably play a more important role in influencing child adiposity than neighborhood characteristics. PMID:26006128

  2. Do Neighborhood Characteristics in Amsterdam Influence Adiposity at Preschool Age?

    Directory of Open Access Journals (Sweden)

    E. Jessica Hrudey

    2015-05-01

    Full Text Available Background: Neighborhood characteristics may contribute to adiposity in young children, but results in the current literature are inconsistent. This study aimed to investigate whether objective (socioeconomic status (SES and subjective (perceived safety, satisfaction with green spaces and perceived physical disorder neighborhood characteristics directly influence child adiposity (as measured by BMI, percent body fat (%BF and waist-to-height ratio (WHtR. Methods: Data on child BMI, %BF and WHtR were obtained from the Amsterdam Born Children and their Development cohort at 5–6 years of age. Three thousand four hundred and sixty nine (3469 children were included in the analyses. Mixed models, using random intercepts for postal code area to account for neighborhood clustering effects, were used to analyze the relationships of interest. Results: Associations were observed for both perceived safety and neighborhood SES with %BF after adjustment for maternal education and ethnicity. All relationships were eliminated with the inclusion of individual covariates and parental BMI into the models. Conclusions: In general, child adiposity at age 5–6 years was not independently associated with neighborhood characteristics, although a small relationship between child %BF and both neighborhood SES and perceived safety cannot be ruled out. At this young age, familial and individual factors probably play a more important role in influencing child adiposity than neighborhood characteristics.

  3. Gender influence on occlusal characteristics in the primary dentition

    Directory of Open Access Journals (Sweden)

    Nisha Rani Yadav

    2014-01-01

    Full Text Available Objectives: The objective of this study was to assess and discuss the influence of gender on occlusal characteristics of primary dentition. Materials and Methods: In this study, cluster randomized sampling was done to select 4-6-year-old children from Government primary schools of Farukh Nagar block, Gurgaon, Haryana, India. Children were evaluated clinically for occlusal characteristics of primary dentition such as molar relation, Canine relation, overjet, overbite, openbite, scissors bite, and crossbite. Chi-square test was used to compare the occlusal characteristics of both genders. Results: Flush terminal plane, Class I Canine relation and both primate as well as developmental spaces were found to be prevalent in the study population, in percentages of 62.4%, 67.2%, and 37.6%, respectively. It was observed that females had more spacing, distal step molar relation and increased overjet as compared to males. Males had more Class II Canine relation, crowding, openbite, overbite, and incompetent lips as compared to females. Significant differences were found between males and females w.r.t various occlusal characteristics. Conclusion: Most of the children had gender influence on malocclusion, which indicates the need for early interception or correction of malocclusion traits based on the gender of the child.

  4. INFLUENCE OF POLYMERIC-DISPERSED REINFORCEMENT ADDITIVES ON THE PERFORMANCE CHARACTERISTICS OF ASPHALT CONCRETE

    Directory of Open Access Journals (Sweden)

    Chernov Sergey Anatolevych

    2017-07-01

    Full Text Available The technique and results of the studies of the influence of a polymeric-dispersed reinforcement additive on the performance characteristics of road hot asphalt concrete, namely, its resistance to fatigue failures, rutting and development of residual deformation are described. It is shown that the proposed method of modification of asphalt-concrete mixtures ensures an increase in the durability of layers of pavement road surface.

  5. Influence of surface roughness on the friction property of textured surface

    OpenAIRE

    Yuankai Zhou; Hua Zhu; Wenqian Zhang; Xue Zuo; Yan Li; Jianhua Yang

    2015-01-01

    In contrast with dimple textures, surface roughness is a texture at the micro-scale, essentially which will influence the load-bearing capacity of lubricant film. The numerical simulation was carried out to investigate the influence of surface roughness on friction property of textured surface. The lubricant film pressure was obtained using the method of computational fluid dynamics according to geometric model of round dimple, and the renormalization-group k–ε turbulent model was adopted in ...

  6. Bio-activated titanium surface utilizable for mimetic bone implantation in dentistry—Part III: Surface characteristics and bone implant contact formation

    Science.gov (United States)

    Strnad, Jakub; Strnad, Zdeněk; Šesták, Jaroslav; Urban, Karel; Povýšil, Ctibor

    2007-05-01

    This study was carried out to quantify the effect of an alkali-modified surface on the bone implant interface formation during healing using an animal model. A total of 24 screw-shaped, self-tapping, (c.p.) titanium dental implants, divided into test group B—implants with alkali-modified surface (Bio surface) and control group M—implants with turned, machined surface, were inserted without pre-tapping in the tibiae of three beagle dogs. The animals were sacrificed after 2, 5 and 12 weeks and the bone implant contact (BIC%) was evaluated histometrically. The surface characteristics that differed between the implant surfaces, i.e. specific surface area, contact angle, may represent factors that influence the rate of osseointegration and the secondary implant stability. The alkali-treated surface enhances the BIC formation during the first 2 5 weeks of healing compared to the turned, machined surface.

  7. ANALYSES OF THE INFLUENCE OF MATERIAL CHARACTERISTICS ON PAVEMENT DESIGN

    Directory of Open Access Journals (Sweden)

    Nino Vukobratović

    2017-01-01

    Full Text Available Currently, only empirical design methods are used in the application of well-known standards for pavement structure design. Given this fact, it is assumed that material characteristics correspond to average quality materials. Thus, the aim of this study included examining the influence of material characteristics on pavement design analyzing changes in the cement bound base layer (CBL characteristics with respect to the occurrence of cracks and changes in the asphalt layer given typical seasonal changes. The study involved varying CBL modulus as 15 GPa, 10 GPa, and 5 GPa. Additionally, the moduli of asphalt layers were varied from 6 MPa to 2 MPa to simulate real conditions in pavement structure life. The analyses indicated that there was a significant difference in pavement behavior with respect to changes in material characteristics. Given these significant differences, it is extremely important to properly define material characteristics while using empirical design methods. Proper material characterization combined with the utilization of empirical and analytical methods increases the possibility of reducing layers thickness to design cost-effective structures.

  8. Biochemical characteristics and bacterial community structure of the sea surface microlayer in the South Pacific Ocean

    Directory of Open Access Journals (Sweden)

    I. Obernosterer

    2008-05-01

    Full Text Available The chemical and biological characteristics of the surface microlayer were determined during a transect across the South Pacific Ocean in October-December 2004. Concentrations of particulate organic carbon (1.3 to 7.6-fold and nitrogen (1.4 to 7-fold, and POC:PON ratios were consistently higher in the surface microlayer as compared to surface waters (5 m. The large variability in particulate organic matter enrichment was negatively correlated to wind speed. No enhanced concentrations of dissolved organic carbon were detectable in the surface microlayer as compared to 5 m, but chromophoric dissolved organic matter was markedly enriched (by 2 to 4-fold at all sites. Based on pigment analysis and cell counts, no consistent enrichment of any of the major components of the autotrophic and heterotrophic microbial community was detectable. CE-SSCP fingerprints and CARD FISH revealed that the bacterial communities present in the surface microlayer had close similarity (>76% to those in surface waters. By contrast, bacterial heterotrophic production (3H-leucine incorporation was consistently lower in the surface microlayer than in surface waters. By applying CARD-FISH and microautoradiography, we observed that Bacteroidetes and Gammaproteobacteria dominated leucine uptake in the surface microlayer, while in surface waters Bacteroidetes and Alphaproteobacteria were the major groups accounting for leucine incorporation. Our results demonstrate that the microbial community in the surface microlayer closely resembles that of the surface waters of the open ocean. Even a short residence in the surface microlayer influences leucine incorporation by different bacterial groups, probably as a response to the differences in the physical and chemical nature of the two layers.

  9. Impact of catchment geophysical characteristics and climate on the regional variability of dissolved organic carbon (DOC) in surface water.

    Science.gov (United States)

    Cool, Geneviève; Lebel, Alexandre; Sadiq, Rehan; Rodriguez, Manuel J

    2014-08-15

    Dissolved organic carbon (DOC) is a recognized indicator of natural organic matter (NOM) in surface waters. The aim of this paper is twofold: to evaluate the impact of geophysical characteristics, climate and ecological zones on DOC concentrations in surface waters and, to develop a statistical model to estimate the regional variability of these concentrations. In this study, multilevel statistical analysis was used to achieve three specific objectives: (1) evaluate the influence of climate and geophysical characteristics on DOC concentrations in surface waters; (2) compare the influence of geophysical characteristics and ecological zones on DOC concentrations in surface waters; and (3) develop a model to estimate the most accurate DOC concentrations in surface waters. The case study involved 115 catchments from surface waters in the Province of Quebec, Canada. Results showed that mean temperatures recorded 60 days prior to sampling, total precipitation 10 days prior to sampling and percentages of wetlands, coniferous forests and mixed forests have a significant positive influence on DOC concentrations in surface waters. The catchment mean slope had a significant negative influence on DOC concentrations in surface waters. Water type (lake or river) and deciduous forest variables were not significant. The ecological zones had a significant influence on DOC concentrations. However, geophysical characteristics (wetlands, forests and slope) estimated DOC concentrations more accurately. A model describing the variability of DOC concentrations was developed and can be used, in future research, for estimating DBPs in drinking water as well evaluating the impact of climate change on the quality of surface waters and drinking water. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Factors influencing the surface quality of polished tool steels

    International Nuclear Information System (INIS)

    Rebeggiani, S; Rosén, B-G

    2014-01-01

    Today’s demands on surface quality of moulds for injection moulding of plastic components involve no/low defect contents and roughness levels in the nm-range for high gloss applications. Material properties as well as operating conditions influence the mould finish, and thus the final surface of moulded products. This paper focuses on how particle content and different polishing strategies influence final surface qualities of moulds. Visual estimations of polished tool steel samples were combined with non-contact 3D-surface texture analysis in order to correlate traditional assessments to more quantitative methods, and to be able to analyse the surfaces at nanometre-level. It was found that steels with a lower proportion of particles, like carbides and oxides, gave rise to smoother polished surfaces. In a comparative study of polishers from different polishing shops, it was found that while different surface preparation strategies can lead to similar final roughness, similar preparation techniques can produce high-quality surfaces from different steel grades. However, the non-contact 3D-surface texture analysis showed that not all smooth polished surfaces have desirable functional topographies for injection moulding of glossy plastic components. (paper)

  11. Grinding and its influence to ground surface durability

    Science.gov (United States)

    Holesovsky, F.; Novak, M.

    2011-01-01

    A number of parameters of running process effect on the formed surface at grinding. Above all, the following influences can be mentioned: grinding wheel speed, workpiece speed, tool properties, rigidity of machine tool, etc. The plastic deformation and thermal load of surface layer are evoked at the action of cutting conditions. A new surface keeps the definite properties, which are given by its roughness, surface profile, geometry accuracy, intensity and residual stress distribution, respectively microhardness course in surface layer and changes of microstructure in this layer. The surface properties predict the surface behaviour in the real machinery at the dynamical, respectively static loading. At the load, the changes of surface properties proceed, e.g. roughness, residual stress. Simultaneously, changes of surface properties influence the durability of machine part and can also lead to surface damage and machine part breakdown. The slackness can also evoke the cracks, which leads to the fracture. The behaviour of part differs in the operating environment without and with oil or in the corrosion environment.

  12. Light, shadows and surface characteristics: the multispectral Portable Light Dome

    Science.gov (United States)

    Watteeuw, Lieve; Hameeuw, Hendrik; Vandermeulen, Bruno; Van der Perre, Athena; Boschloos, Vanessa; Delvaux, Luc; Proesmans, Marc; Van Bos, Marina; Van Gool, Luc

    2016-11-01

    A multispectral, multidirectional, portable and dome-shaped acquisition system is developed within the framework of the research projects RICH (KU Leuven) and EES (RMAH, Brussels) in collaboration with the ESAT-VISICS research group (KU Leuven). The multispectral Portable Light Dome (MS PLD) consists of a hemispherical structure, an overhead camera and LEDs emitting in five parts of the electromagnetic spectrum regularly covering the dome's inside surface. With the associated software solution, virtual relighting and enhancements can be applied in a real-time, interactive manner. The system extracts genuine 3D and shading information based on a photometric stereo algorithm. This innovative approach allows for instantaneous alternations between the computations in the infrared, red, green, blue and ultraviolet spectra. The MS PLD system has been tested for research ranging from medieval manuscript illuminations to ancient Egyptian artefacts. Preliminary results have shown that it documents and measures the 3D surface structure of objects, re-visualises underdrawings, faded pigments and inscriptions, and examines the MS results in combination with the actual relief characteristics of the physical object. Newly developed features are reflection maps and histograms, analytic visualisations of the reflection properties of all separate LEDs or selected areas. In its capacity as imaging technology, the system acts as a tool for the analysis of surface materials (e.g. identification of blue pigments, gold and metallic surfaces). Besides offering support in answering questions of attribution and monitoring changes and decay of materials, the PLD also contributes to the identification of materials, all essential factors when making decisions in the conservation protocol.

  13. Influence of surface topography on the sputtering yields of silver

    International Nuclear Information System (INIS)

    Pan Jisheng; Wang Zhenxia; Tao Zhenlan; Zhang Jiping

    1992-01-01

    The sputtering yields of silver have been measured as a function of the fluence of incident Ar + ions (27 keV) using the collector technique and RBS analysis. The irradiated surface was examined by scanning electron microscopy (SEM). It is shown that the sputtering yields of surfaces with topography are enhanced relative to smooth surfaces of silver, but the extent of the enhancement depends on the irradiation dose. The experimental results can be explained assuming that the surface topography and sputtering yield are a function of incident angle. It is obvious that the surface topography is an important factor to influence the sputtering yield. The term ''apparent sputtering yield'' has specifically been used when referring to the experimental sputtering yield of a surface with topography, to emphasize the difference with a smooth surface. (orig.)

  14. The baffle influence on sound radiation characteristics of a plate

    Directory of Open Access Journals (Sweden)

    Bao Liu

    2017-01-01

    Full Text Available The acoustic radiation characteristics of the baffle plates and unbaffle plates are calculated and compared by single-layer potential and double-layer potential. Based on the boundary integral equation, the sound pressure integral equation of the baffle and the baffle are deduced respectively. According to the boundary compatibility condition, the sound pressure and the vibration velocity of the plates are obtained. Further, the dynamic equation of the structure is substituted into the vibration equation in the form of the baffle plate and the baffle plate. The sound pressure difference and the displacement of a plate surface are in the form of the vibration mode superposition and the acoustic radiation impedance of the double integral form is obtained, which determines vibration mode coefficient and sound radiation parameters. The effect of the baffle on the acoustic radiation characteristics of the thin plate is analyzed by comparing the acoustic radiation parameters with the simple and simple rectangular plate in water.

  15. Chemistry in interstellar space. [environment characteristics influencing reaction dynamics

    Science.gov (United States)

    Donn, B.

    1973-01-01

    The particular characteristics of chemistry in interstellar space are determined by the unique environmental conditions involved. Interstellar matter is present at extremely low densities. Large deviations from thermodynamic equilibrium are, therefore, to be expected. A relatively intense ultraviolet radiation is present in many regions. The temperatures are in the range from 5 to 200 K. Data concerning the inhibiting effect of small activation energies in interstellar clouds are presented in a table. A summary of measured activation energies or barrier heights for exothermic exchange reactions is also provided. Problems of molecule formation are discussed, taking into account gas phase reactions and surface catalyzed processes.

  16. Improvements and validation of the linear surface characteristics scheme

    International Nuclear Information System (INIS)

    Santandrea, S.; Jaboulay, J.C.; Bellier, P.; Fevotte, F.; Golfier, H.

    2009-01-01

    In this paper we present the last improvements of the recently proposed linear surface (LS) characteristics scheme for unstructured meshes. First we introduce a new numerical tracking technique, specifically adapted to the LS method, which tailors transverse integration weights to take into account the geometrical discontinuities that appear along the pipe affected to every trajectory in classical characteristics schemes. Another development allows using the volumetric flux variation of the LS method to re-compute step-wise constant fluxes to be used in other parts of a computational scheme. This permits to take greater advantage of the higher precision of the LS method without necessarily conceiving specialized theories for all the modular functionalities of a spectral code such as APOLLO2. Moreover we present a multi-level domain decomposition method for solving the synthetic acceleration operator that is used to accelerate the free iterations for the LS method. We discuss all these new developments by illustrating some benchmarks results obtained with the LS method. This is done by detailed comparisons with Monte-Carlo calculations. In particular we show that the new method can be used not only as a reference tool, but also inside a suitable industrial calculation scheme

  17. [Surface ECG characteristics of right and left atrial flutter].

    Science.gov (United States)

    Rostock, Thomas; Konrad, Torsten; Sonnenschein, Sebastian; Mollnau, Hanke; Ocete, Blanca Quesada; Bock, Karsten; Spittler, Raphael; Huber, Carola; Theis, Cathrin

    2015-09-01

    Atrial tachycardia in virtually all areas of both atria has become more important in the clinical management of patients with previous complex atrial fibrillation ablation. Accurate interpretation of surface electrocardiogram (ECG) characteristics is of paramount importance to localize the origin of atrial tachycardia, particularly for planning interventional treatment. This article highlights the ECG features of different types of right and left atrial tachycardia. Typical right atrial flutter through the cavotricuspid isthmus conducts septally in a cranial direction and demonstrates sawtooth-like flutter waves which start negative in II, III and aVF and then show a steep slope upwards to the isoelectric line. The flutter rate typically ranges between 240-250 beats/min. In contrast, right atrial flutter in a clockwise rotation, flutter around the vena cava inferior or superior and around a scar (e.g. after cardiac surgery) show positive or biphasic flutter waves (lower or upper loop reentry). Left atrial flutter waves (e.g. around the mitral valve or around the pulmonary veins) are very heterogeneous and are typically positive in V1 as the left atrium is located in the posterior mediastinum. Specific knowledge of flutter wave morphology in surface ECG facilitates planning and performance of the ablation strategy.

  18. The influence of maternal psychosocial characteristics on infant feeding styles.

    Science.gov (United States)

    Barrett, Katherine J; Thompson, Amanda L; Bentley, Margaret E

    2016-08-01

    Maternal feeding styles in infancy and early childhood are associated with children's later risk for overweight and obesity. Maternal psychosocial factors that influence feeding styles during the complementary feeding period, the time during which infants transition from a milk-based diet to one that includes solid foods and other non-milk products, have received less attention. The present study explores how maternal psychosocial factors-specifically self-esteem, parenting self-efficacy, parenting satisfaction, and depression symptoms-influence mothers' infant feeding styles at nine months of age, a time during which solid foods eating habits are being established. Participants included 160 low-income, African-American mother-infant pairs in central North Carolina who were enrolled in the Infant Care and Risk of Obesity Study. Regression models tested for associations between maternal psychosocial characteristics and pressuring and restrictive feeding styles. Models were first adjusted for maternal age, education, marital status and obesity status. To account for infant characteristics, models were then adjusted for infant weight-for-length, distress to limitations and activity level scores. Maternal self-esteem was negatively associated with pressuring to soothe. Maternal parenting self-efficacy was positively associated with restriction-diet quality. Maternal parenting satisfaction and depression symptoms were not associated with feeding styles in the final models. Focusing on strengthening maternal self-esteem and parenting self-efficacy may help to prevent the development of less desirable infant feeding styles. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Relationship between wettability and lubrication characteristics of the surfaces of contacting phospholipid-based membranes.

    Science.gov (United States)

    Pawlak, Zenon; Petelska, Aneta D; Urbaniak, Wieslaw; Yusuf, Kehinde Q; Oloyede, Adekunle

    2013-04-01

    The wettability of the articular surface of cartilage depends on the condition of its surface active phospholipid overlay, which is structured as multi-bilayer. Based on a hypothesis that the surface of cartilage facilitates the almost frictionless lubrication of the joint, we examined the characteristics of this membrane surface entity in both its normal and degenerated conditions using a combination of atomic force microscopy, contact angle measurement, and friction test methods. The observations have led to the conclusions that (1) the acid-base equilibrium condition influences the lubrication effectiveness of the surface of cartilage and (2) the friction coefficient is significantly dependent on the hydrophobicity of the surface of the tissue, thereby confirming the hypothesis tested in this paper. Both wettability angle and interfacial energy were obtained for varying conditions of the cartilage surface both in its wet, dry and lipid-depleted conditions. The interfacial energy also increased with mole fraction of the lipid species reaching an asymptotic value after 0.6. Also, the friction coefficient was found to decrease to an asymptotic level as the wettability angle increased. The result reveal that the interfacial energy increased with pH till pH = 4.0, and then decreased from pH = 4.0 to reach equilibrium at pH = 7.0.

  20. The characteristics of surface oxidation and corrosion resistance of nitrogen implanted zircaloy-4

    International Nuclear Information System (INIS)

    Tang, G.; Choi, B.H.; Kim, W.; Jung, K.S.; Kwon, H.S.; Lee, S.J.; Lee, J.H.; Song, T.Y.; Shon, D.H.; Han, J.G.

    1997-01-01

    This work is concerned with the development and application of ion implantation techniques for improving the corrosion resistance of zircaloy-4. The corrosion resistance in nitrogen implanted zircaloy-4 under a 120 keV nitrogen ion beam at an ion dose of 3 x 10 17 cm -2 depends on the implantation temperature. The characteristics of surface oxidation and corrosion resistance were analyzed with the change of implantation temperature. It is shown that as implantation temperature rises from 100 to 724 C, the colour of specimen surface changes from its original colour to light yellow at 100 C, golden at 175 C, pink at 300 C, blue at 440 C and dark blue at 550 C. As the implantation temperature goes above 640 C, the colour of surface changes to light black, and the surface becomes a little rough. The corrosion resistance of zircaloy-4 implanted with nitrogen is sensitive to the implantation temperature. The pitting potential of specimens increases from 176 to 900 mV (SCE) as the implantation temperature increases from 100 to 300 C, and decreases from 900 to 90 mV(SCE) as the implantation temperature increases from 300 to 640 C. The microstructure, the distribution of oxygen, nitrogen and carbon elements, the oxide grain size and the feature of the precipitation in the implanted surface were investigated by optical microscope, TEM, EDS, XRD and AES. The experimental results reveal that the ZrO 2 is distributed mainly on the outer surface. The ZrN is distributed under the ZrO 2 layer. The characteristics of the distribution of ZrO 2 and ZrN in the nitrogen-implanted zircaloy-4 is influenced by the implantation temperature of the sample, and in turn the corrosion resistance is influenced. (orig.)

  1. Influence of the Surface Layer on the Electrochemical Deposition of Metals and Semiconductors into Mesoporous Silicon

    Energy Technology Data Exchange (ETDEWEB)

    Chubenko, E. B., E-mail: eugene.chubenko@gmail.com; Redko, S. V.; Sherstnyov, A. I.; Petrovich, V. A.; Kotov, D. A.; Bondarenko, V. P. [Belarusian State University of Information and RadioElectronics (Belarus)

    2016-03-15

    The influence of the surface layer on the process of the electrochemical deposition of metals and semiconductors into porous silicon is studied. It is shown that the surface layer differs in structure and electrical characteristics from the host porous silicon bulk. It is established that a decrease in the conductivity of silicon crystallites that form the surface layer of porous silicon has a positive effect on the process of the filling of porous silicon with metals and semiconductors. This is demonstrated by the example of nickel and zinc oxide. The effect can be used for the formation of nanocomposite materials on the basis of porous silicon and nanostructures with a high aspect ratio.

  2. Influence of Surface Energy Effects on Elastic Fields of a Layered Elastic Medium under Surface Loading

    Directory of Open Access Journals (Sweden)

    Supakorn Tirapat

    2017-01-01

    Full Text Available This paper presents the analysis of a layered elastic half space under the action of axisymmetric surface loading and the influence of the surface energy effects. The boundary value problems for the bulk and the surface are formulated based on classical linear elasticity and a complete Gurtin-Murdoch constitutive relation. An analytical technique using Love’s representation and the Hankel integral transform is employed to derive an integral-form solution for both displacement and stress fields. An efficient numerical quadrature is then applied to accurately evaluate all involved integrals. Selected numerical results are presented to portray the influence of various parameters on elastic fields. Numerical results indicate that the surface stress displays a significant influence on both displacement and stress fields. It is also found that the layered half space becomes stiffer with the presence of surface stresses. In addition, unlike the classical elasticity solution, size-dependent behavior of elastic fields is noted. The present analytical solutions provide fundamental understanding of the influence of surface energy on layered elastic materials. It can also be used as a benchmark solution for the development of numerical techniques such as FEM and BEM, for analysis of more complex problems involving a layered medium under the influence of surface energy effects.

  3. Influence of surface treatments on corrosion resistance of stainless steels. Residual stresses in metals

    International Nuclear Information System (INIS)

    Berge, J. Philippe

    1968-05-01

    In a first part, this research thesis proposes presentation of the definition of a surface condition: chemical characteristics such as passivity and contamination, physical characteristics (obtained through micrographic methods, X ray diffusion, magnetic methods), and micro-geometrical characteristics. The author notably discusses the measurement of characteristics either by appropriate conventional methods or by an original method in the case of passivity. In a second part, the author reports the study of the influence of surface condition on different types of corrosion of stainless steels in chemical environments (corrosion in sulphuric acid, intergranular corrosion, stress corrosion cracking in magnesium chloride, pitting corrosion) and of high temperature oxidation (corrosion in pressurized water, oxidation in dry vapour or in carbon dioxide)

  4. Investigation of surface roughness influence on hyperbolic metamaterial performance

    Directory of Open Access Journals (Sweden)

    S. Kozik

    2014-12-01

    Full Text Available The main goal of this work was to introduce simple model of surface roughness which does not involve objects with complicated shapes and could help to reduce computational costs. We described and proved numerically that the influence of surface roughness at the interfaces in metal-dielectric composite materials could be described by proper selection of refractive index of dielectric layers. Our calculations show that this model works for roughness with RMS value about 1 nm and below.

  5. Influence of starting material particle size on pellet surface roughness.

    Science.gov (United States)

    Sarkar, Srimanta; Ang, Bee Hwee; Liew, Celine Valeria

    2014-02-01

    The purpose of this study was to investigate the effect of pelletization aids, i.e., microcrystalline cellulose (MCC) and cross-linked polyvinyl pyrrolidone (XPVP), and filler, i.e., lactose, particle size on the surface roughness of pellets. Pellets were prepared from powder blends containing pelletization aid/lactose in 1:3 ratio by extrusion-spheronization. Surface roughness of pellets was assessed quantitatively and qualitatively using optical interferometry and scanning electron microscopy, respectively. Both quantitative and qualitative surface studies showed that surface roughness of pellets depended on the particle size of XPVP and lactose used in the formulation. Increase in XPVP or lactose particle size resulted in rougher pellets. Formulations containing MCC produced pellets with smoother surfaces than those containing XPVP. Furthermore, surface roughness of the resultant pellets did not appear to depend on MCC particle size. Starting material particle size was found to be a critical factor for determining the surface roughness of pellets produced by extrusion-spheronization. Smaller particles can pack well with lower peaks and valleys, resulting in pellets with smoother surfaces. Similar surface roughness of pellets containing different MCC grades could be due to the deaggregation of MCC particles into smaller subunits with more or less similar sizes during wet processing. Hence, for starting materials that deaggregate during the wet processing, pellet surface roughness is influenced by the particle size of the material upon deaggregation.

  6. Effects of Surface Treatment of Activated Carbon on Its Surface and Cr(VI) Adsorption Characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Park, Soo Jin; Jang, Yu Sin [Advanced Materials Division., Korea Research Institute of Chimical Technology, Taejon (Korea)

    2001-04-01

    In this work, the effect of surface treatments on activated carbons (ACs) has been studied in the context of gas and liquid adsorption behaviors. The chemical solutions used in this experiment were 35% sodium hydroxide, and these were used for the acidic and basic treatments, respectively. The surface properties have been determined by pH, acid-base values, and FT-IR. The adsorption isotherms of Cr(VI) ion on activated carbons have been studied with the 5 mg/l concentration at ambient temperature. N{sub 2} adsorption isotherm characteristics, which include the specific surface area, micro pore volume, and microporosity, were determined by BET and Boer's-plot methods. In case of the acidic treatment of activated carbons, it was observed that the adsorption of Cr(VI) ion was more effective due to the increase acid value (or acidic functional group) of activated carbon surfaces. However, the basic treatment on activated carbons was caused no significant effects, probably due to the decreased specific surface area and total pore volume. 27 refs., 7 figs., 4 tabs.

  7. Influence of substrate surfaces on the growth of organic films

    Science.gov (United States)

    Das, A.; Salvan, G.; Kampen, T. U.; Hoyer, W.; Zahn, D. R. T.

    2003-05-01

    3,4,9,10-Perylene tetracarboxylic dianhydride (PTCDA) films were grown by organic molecular beam deposition (OMBD) under UHV conditions on hydrogen terminated Si(1 0 0) and sulphur passivated GaAs(1 0 0) surfaces. X-ray diffraction (XRD), X-ray reflectivity (XRR), Raman spectroscopy, and atomic force microscopy (AFM) are employed to study the influence of substrate surfaces on the structural properties of the organic films. Both phases of PTCDA, α- and β-polymorphs, are found to grow on both substrates. The substrate surfaces determine the preferential growth of α- and β-phases of PTCDA crystals at room temperature.

  8. Influence of polymer additive molecular weight on surface and ...

    Indian Academy of Sciences (India)

    The adsorbed layer formed of PEG and chloride ion (Cl−) in the presence of copper ions has a definite role in controlling the deposition mechanism and the coating characteristics. The adsorption behaviour and suppressor nature of PEG with different MW (200–20000) on the physicochemical and the surface morphological ...

  9. Surface characteristics, corrosion and bioactivity of chemically treated biomedical grade NiTi alloy.

    Science.gov (United States)

    Chembath, Manju; Balaraju, J N; Sujata, M

    2015-11-01

    The surface of NiTi alloy was chemically modified using acidified ferric chloride solution and the characteristics of the alloy surface were studied from the view point of application as a bioimplant. Chemically treated NiTi was also subjected to post treatments by annealing at 400°C and passivation in nitric acid. The surface of NiTi alloy after chemical treatment developed a nanogrid structure with a combination of one dimensional channel and two dimensional network-like patterns. From SEM studies, it was found that the undulations formed after chemical treatment remained unaffected after annealing, while after passivation process the undulated surface was filled with oxides of titanium. XPS analysis revealed that the surface of passivated sample was enriched with oxides of titanium, predominantly TiO2. The influence of post treatment on the corrosion resistance of chemically treated NiTi alloy was monitored using Potentiodynamic Polarization and Electrochemical Impedance Spectroscopy (EIS) in Phosphate Buffered Saline (PBS) solution. In the chemically treated condition, NiTi alloy exhibited poor corrosion resistance due to the instability of the surface. On the other hand, the breakdown potential (0.8V) obtained was highest for the passivated samples compared to other surface treated samples. During anodic polarization, chemically treated samples displayed dissolution phenomenon which was predominantly activation controlled. But after annealing and passivation processes, the behavior of anodic polarization was typical of a diffusion controlled process which confirmed the enhanced passivity of the post treated surfaces. The total resistance, including the porous and barrier layer, was in the range of mega ohms for passivated surfaces, which could be attributed to the decrease in surface nickel content and formation of compact titanium oxide. The passivated sample displayed good bioactivity in terms of hydroxyapatite growth, noticed after 14days immersion in

  10. Influence of the crystallographic structure of the electrode surface on the structure of the electrical double layer and adsorption of organic molecules

    International Nuclear Information System (INIS)

    Kochorovski, Z.; Zagorska, I.; Pruzhkovska-Drakhal, R.; Trasatti, S.

    1995-01-01

    The results of systematic investigation of influence of crystal structure of Bi-, Sb- and Cd-electrode surfaces on regularities of double electric layer structure in aqueous and nonaqueous solutions of surface-nonactive electrolyte are given. Influence of electrode surface characteristics on adsorptive behaviour of different organic molecules has been studied. General regularities of of chemical nature influence and surface crystallographic structure on the double layer structure and on organic compounds adsorption have been established. 57 refs., 7 figs., 4 tabs

  11. INFLUENCE OF WORKPIECE SURFACE PREPARATION ON THERMAL BARRIER COATING DURABILITY

    Directory of Open Access Journals (Sweden)

    M. A. Petrova

    2014-01-01

    Full Text Available Article deals with the impact of workpiece surface quality on adhesive strength and durability of thermal barrier coating. The result revealed that the roughness of metal layer influences on the adhesion of ceramic coating and depends the thickness of ceramic crystals when using method of Electron beam deposition.

  12. Surface water assessment on the influence of space distribution on ...

    African Journals Online (AJOL)

    In this work, the influence of space distribution on physico-chemical parameters of refinery effluent discharge has been studied, using treated effluent water discharged from the Port Harcourt Refinery Company (PHRC) into the Ekerekana Creek in Okrika as reference. Samples were collected at surface level from the ...

  13. Influence of deposition rate on PL spectrum and surface morphology ...

    Indian Academy of Sciences (India)

    Influence of deposition rate on PL spectrum and surface morphology of ZnO nanolayers deposited on Si (100) substrate. A ZENDEHNAM. ∗. , M MIRZAEE and S MIRI. Thin Film Laboratory, Department of Physics, Faculty of Science, Arak University, Arak 38156-8-8349, Iran. MS received 26 March 2012; revised 5 May 2012.

  14. Influence of rigid boundary on the propagation of torsional surface ...

    Indian Academy of Sciences (India)

    Influence of rigid boundary on the propagation of torsional surface wave in an inhomogeneous layer. Shishir Gupta. ∗. , Rehena Sultana and Santimoy Kundu. Department of Applied Mathematics, Indian School of Mines, Dhanbad 826 004, India. ∗. Corresponding author. e-mail: shishir ism@yahoo.com. The present work ...

  15. Surface sterilization and duration of seed storage influenced ...

    African Journals Online (AJOL)

    The effects of factorial combinations of four storage duration (in days after seed extraction) and surface sterilization with three dilution levels of sodium hypochlorite on seedling emergence and seedling quality of African breadfruit were studied. Storage duration significantly influenced days to seedling emergence, ...

  16. [Backscattering Characteristics of Machining Surfaces and Retrieval of Surface Multi-Parameters].

    Science.gov (United States)

    Tao, Hui-rong; Zhang, Fu-min; Qu, Xing-hua

    2015-07-01

    For no cooperation target laser ranging, the backscattering properties of the long-range and real machined surfaces are uncertain which seriously affect the ranging accuracy. It is an important bottleneck restricting the development of no cooperation ranging technology. In this paper, the backscattering characteristics of three typical machining surfaces (vertidal milling processing method, horizontal milling processing method and plain grinding processing method) under the infrared laser irradiation with 1550 nm were measured. The relation between the surface nachining texture, incident azimuth, roughness and the backscattering distribution were analyzed and the reasons for different processing methods specific backscattering field formed were explored. The experimental results show that the distribution of backscattering spectra is greatly affected by the machined processing methods. Incident angle and roughness have regularity effect on the actual rough surface of each mode. To be able to get enough backscattering, knowing the surface texture direction and the roughness of machined metal is essential for the optimization of the non-contact measurement program in industry. On this basis, a method based on an artificial neural network (ANN) and genetic algorithm (GA), is proposed to retrieve the surface multi-parameters of the machined metal. The generalized regression neural network (GRNN) was investigated and used in this application for the backscattering modeling. A genetic algorithm was used to retrieve the multi-parameters of incident azimuth angle, roughness and processing methods of machined metal sur face. Another processing method of sample (planer processing method) was used to validate data. The final results demonstrated that the method presented was efficient in parameters retrieval tasks. This model can accurately distinguish processing methods and the relative error of incident azimuth and roughness is 1.21% and 1.03%, respectively. The inversion

  17. Influence of Biomass Chemical Properties on Torrefaction Characteristics

    DEFF Research Database (Denmark)

    Saleh, Suriyati Binti; Hansen, Brian Brun; Jensen, Peter Arendt

    2013-01-01

    Different biomass types may differ with respect to torrefaction characteristics, and an improved understanding and ability to predict the torrefaction performance is, therefore, desired. In this study, the influence of the chemical properties (lignocellulose composition and alkali content......) on the torrefaction behavior with respect to mass loss and grindability is investigated by simultaneous thermal analysis (STA) and by using a combined torrefaction and grinding reactor. The torrefaction behavior of six raw biomass samples and selected pretreated samples (washed and impregnated with KCl and K2CO3) has...... of the torrefied products was evaluated by determining the d50 value of the particle size distribution of the biomass before and after torrefaction in the combined torrefaction and mill reactor. A significant decrease in d50 value was observed when the alkali content increased from 0 to 0.2 wt % db, whereas...

  18. Soil-geomorphic significance of land surface characteristics in an arid mountain range, Mojave Desert, USA

    Science.gov (United States)

    Hirmas, D.R.; Graham, R.C.; Kendrick, K.J.

    2011-01-01

    Mountains comprise an extensive and visually prominent portion of the landscape in the Mojave Desert, California. Landform surface properties influence the role these mountains have in geomorphic processes such as dust flux and surface hydrology across the region. The primary goal of this study was to describe and quantify land surface properties of arid-mountain landforms as a step toward unraveling the role these properties have in soil-geomorphic processes. As part of a larger soil-geomorphic study, four major landform types were identified within the southern Fry Mountains in the southwestern Mojave Desert on the basis of topography and landscape position: mountaintop, mountainflank, mountainflat (intra-range low-relief surface), and mountainbase. A suite of rock, vegetation, and morphometric land surface characteristic variables was measured at each of 65 locations across the study area, which included an associated piedmont and playa. Our findings show that despite the variation within types, landforms have distinct land surface properties that likely control soil-geomorphic processes. We hypothesize that surface expression influences a feedback process at this site where water transports sediment to low lying areas on the landscape and wind carries dust and soluble salts to the mountains where they are washed between rocks, incorporated into the soil, and retained as relatively long-term storage. Recent land-based video and satellite photographs of the dust cloud emanating from the Sierra Cucapá Mountains in response to the 7.2-magnitude earthquake near Mexicali, Mexico, support the hypothesis that these landforms are massive repositories of dust.

  19. Reflectance variability of surface coatings reveals characteristic eigenvalue spectra

    Science.gov (United States)

    Medina, José M.; Díaz, José A.; Barros, Rui

    2012-10-01

    We have examined the trial-to-trial variability of the reflectance spectra of surface coatings containing effect pigments. Principal component analysis of reflectances was done at each detection angle separately. A method for classification of principal components is applied based on the eigenvalue spectra. It was found that the eigenvalue spectra follow characteristic power laws and depend on the detection angle. Three different subsets of principal components were examined to separate the relevant spectral features related to the pigments from other noise sources. Reconstruction of the reflectance spectra by taking only the first subset indicated that reflectance variability was higher at near-specular reflection, suggesting a correlation with the trial-to-trial deposition of effect pigments. Reconstruction by using the second subset indicates that variability was higher at short wavelengths. Finally, reconstruction by using only the third subset indicates that reflectance variability was not totally random as a function of the wavelength. The methods employed can be useful in the evaluation of color variability in industrial paint application processes.

  20. Influence of the atomic structure of crystal surfaces on the surface diffusion in medium temperature range

    International Nuclear Information System (INIS)

    Cousty, J.P.

    1981-12-01

    In this work, we have studied the influence of atomic structure of crystal surface on surface self-diffusion in the medium temperature range. Two ways are followed. First, we have measured, using a radiotracer method, the self-diffusion coefficient at 820 K (0.6 T melting) on copper surfaces both the structure and the cleanliness of which were stable during the experiment. We have shown that the interaction between mobile surface defects and steps can be studied through measurements of the anisotropy of surface self diffusion. Second, the behavior of an adatom and a surface vacancy is simulated via a molecular dynamics method, on several surfaces of a Lennard Jones crystal. An inventory of possible migration mechanisms of these surface defects has been drawn between 0.35 and 0.45 Tsub(m). The results obtained with both the methods point out the influence of the surface atomic structure in surface self-diffusion in the medium temperature range [fr

  1. Influence of shear velocity on frictional characteristics of rock surface

    Indian Academy of Sciences (India)

    stress (Pa), μ0 the initial coefficient of friction, a, b the experimentally determined constant, V the displacement rate (m/s), θ the 'state' variables, Dc the critical slip distance and V0 the initial displace- ment rate (m/s). In order to study the velocity effect on fric- tion for shaly sandstone, the two blocks were kept one over the ...

  2. Influence of shear velocity on frictional characteristics of rock surface

    Indian Academy of Sciences (India)

    Author Affiliations. T N Singh1 A K Verma2 Tanmay Kumar3 Avi Dutt3. Department of Earth Sciences, Indian Institute of Technology, Powai, Mumbai 400 056, India. CeRES, The Energy and Resources Institute, Darbari Seth Block, IHC Complex, Lodhi Road, New Delhi 110 003, India. Institute of Technology, Banaras Hindu ...

  3. [INVITED] Laser treatment of Inconel 718 alloy and surface characteristics

    Science.gov (United States)

    Yilbas, B. S.; Ali, H.; Al-Aqeeli, N.; Karatas, C.

    2016-04-01

    Laser surface texturing of Inconel 718 alloy is carried out under the high pressure nitrogen assisting gas. The combination of evaporation and melting at the irradiated surface is achieved by controlling the laser scanning speed and the laser output power. Morphological and metallurgical changes in the treated surface are analyzed using the analytical tools including optical, electron scanning, and atomic force microscopes, energy dispersive spectroscopy, and X-ray diffraction. Microhardnes and friction coefficient of the laser treated surface are measured. Residual stress formed in the surface region is determined from the X-ray diffraction data. Surface hydrophobicity of the laser treated layer is assessed incorporating the sessile drop method. It is found that laser treated surface is free from large size asperities including cracks and the voids. Surface microhardness increases significantly after the laser treatment process, which is attributed to the dense layer formation at the surface under the high cooling rates, dissolution of Laves phase in the surface region, and formation of nitride species at the surface. Residual stress formed is compressive in the laser treated surface and friction coefficient reduces at the surface after the laser treatment process. The combination of evaporation and melting at the irradiated surface results in surface texture composes of micro/nano-poles and pillars, which enhance the surface hydrophobicity.

  4. Dispersion states and surface characteristics of physically blended polyhedral oligomeric silsesquioxane/polymer hybrid nanocomposites

    Science.gov (United States)

    Misra, Rahul

    Control of dispersion and segregation states of nanostructured additives is one of the biggest challenges in realizing the optimum potential of high performance hybrid polymer nanocomposites. Polyhedral oligomeric silsesquioxane (POSS) nanostructured chemicals, with their hybrid organic-inorganic nature and flexible functionalization with a variety of organic substituents, yield possibilities to control dispersion and tune compatibility in a wide range of polymer systems. The overall goal of this research is to investigate the fundamental parameters that influence the dispersion and segregation states of POSS nanostructured chemicals, and to understand chain dynamics and conformations in physically blended POSS hybrid polymer nanocomposites (HPNC's). Multiple structural and mechanical factors influencing macro to nano scale surface and bulk properties were successfully investigated and correlated. A strategy based on thermodynamic principles for selective control of POSS dispersion states in a given polymer matrix is developed and discussed. This dissertation consists of eight chapters. Chapter 1 provides a detailed introduction about the development and current research interest in POSS/polymer nanocomposites. This chapter also discusses limitations of current advanced nanoprobe techniques. Chapter 2 establishes the overall goal of this research and specific research ii objectives. Chapter 3 establishes the preferential surface migration behavior of physically dispersed, non-reactive, closed cage octaisobutyl POSS (Oib-POSS) in a non-polar polypropylene matrix. Furthermore, influence of POSS surface segregation on the surface properties, especially nano-tribomechanical behavior is also discussed. Chapter 4 expands the studies by melt blending two different types of POSS molecules, a non-reactive, closed cage Oib-POSS and an open cage trisilanolphenyl POSS (Tsp-POSS), in a nylon 6 matrix. This chapter discusses the morphology, nano-dispersion and macro- to

  5. Influence of surface structure and chemistry on water droplet splashing.

    Science.gov (United States)

    Koch, Kerstin; Grichnik, Roland

    2016-08-06

    Water droplet splashing and aerosolization play a role in human hygiene and health systems as well as in crop culturing. Prevention or reduction of splashing can prevent transmission of diseases between animals and plants and keep technical systems such as pipe or bottling systems free of contamination. This study demonstrates to what extent the surface chemistry and structures influence the water droplet splashing behaviour. Smooth surfaces and structured replicas of Calathea zebrina (Sims) Lindl. leaves were produced. Modification of their wettability was done by coating with hydrophobizing and hydrophilizing agents. Their wetting was characterized by contact angle measurement and splashing behaviour was observed with a high-speed video camera. Hydrophobic and superhydrophilic surfaces generally showed fewer tendencies to splash than hydrophobic ones. Structuring amplified the underlying behaviour of the surface chemistries, increasing hydrophobic surfaces' tendency to splash and decreasing splash on hydrophilic surfaces by quickly transporting water off the impact point by capillary forces. The non-porous surface structures found in C. zebrina could easily be applied to technical products such as plastic foils or mats and coated with hydrophilizing agents to suppress splash in areas of increased hygiene requirements or wherever pooling of liquids is not desirable.This article is part of the themed issue 'Bioinspired hierarchically structured surfaces for green science'. © 2016 The Author(s).

  6. Influence of building resolution on surface water inundation outputs

    Science.gov (United States)

    Green, Daniel; Yu, Dapeng; Pattison, Ian

    2016-04-01

    Surface water (pluvial) flooding occurs when intense precipitation events overwhelm the drainage capacity of an area and excess water is unable to infiltrate into the ground or drain via natural or artificial drainage channels. In the UK, over 3 million properties are at risk from surface water flooding alone, accounting for approximately one third of all UK flood risk. This risk is predicted to increase due to future climatic changes resulting in an increasing magnitude and frequency of intense precipitation events. Numerical modelling is a well-established method of investigating surface water flood risk, allowing the researcher to gain an understanding of the depth, extent and severity of actual or hypothetical flood scenarios. Although numerical models allow the simulation of surface water inundation in a particular region, the model parameters (e.g. roughness, hydraulic conductivity) and resolution of topographic data have been shown to exert a profound influence on the inundation outputs which often leads to an over- or under-estimation of flood depths and extent without the use of external validation data to calibrate model outputs. Although previous research has demonstrated that model outputs are highly sensitive to Digital Elevation Model (DEM) mesh resolution, with flood inundation over large and complex topographies often requiring mesh resolutions coarser than the structural features (e.g. buildings) present within the study catchment, the specific influence of building resolution on surface flowpaths and connectivity during a surface water flood event has not been investigated. In this study, a LiDAR-derived DEM and OS MasterMap buildings layer of the Loughborough University campus, UK, were rasterized into separate 1m, 5m and 10m resolution layers. These layers were combined to create a series of Digital Surface Models (DSM) with varying, mismatching building and DEM resolutions (e.g. 1m DEM resolution, 10m building resolution, etc.) to understand

  7. Influence of technological factors on characteristics of hybrid fluid-film bearings

    Science.gov (United States)

    Koltsov, A.; Prosekova, A.; Rodichev, A.; Savin, L.

    2017-08-01

    The influence of the parameters of micro- and macrounevenness on the characteristics of a hybrid bearing with slotted throttling is considered in the present paper. The quantitative assumptions of calculation of pressure distribution, load capacity, lubricant flow rate and power loss due to friction in a radial hybrid bearing with slotted throttling are taken into account, considering the shape, dimensions and roughness of the support surfaces inaccuracies. Numerical simulation of processes in the lubricating layer is based on the finite-difference solution of the Reynolds equation using an uneven orthogonal computational grid with adaptive condensation. The results of computational and physical experiments are presented.

  8. Do Individual and Neighborhood Characteristics Influence Perceived Air Quality?

    Science.gov (United States)

    Deguen, Séverine; Padilla, Manon; Padilla, Cindy; Kihal-Talantikite, Wahida

    2017-12-12

    subjective and objective measures of air pollution in many population sub-groups with different combinations of individual characteristics. The relationship is less clear among the oldest population, which confirms previous findings. Our finding highlights that age combined with low level of education and unemployment, or women or health problems as well as the neighborhood deprivation index influence the level of air quality satisfaction.

  9. Do Individual and Neighborhood Characteristics Influence Perceived Air Quality?

    Directory of Open Access Journals (Sweden)

    Séverine Deguen

    2017-12-01

    between the subjective and objective measures of air pollution in many population sub-groups with different combinations of individual characteristics. The relationship is less clear among the oldest population, which confirms previous findings. Our finding highlights that age combined with low level of education and unemployment, or women or health problems as well as the neighborhood deprivation index influence the level of air quality satisfaction.

  10. Wetlands inform how climate extremes influence surface water expansion and contraction

    Directory of Open Access Journals (Sweden)

    M. K. Vanderhoof

    2018-03-01

    Full Text Available Effective monitoring and prediction of flood and drought events requires an improved understanding of how and why surface water expansion and contraction in response to climate varies across space. This paper sought to (1 quantify how interannual patterns of surface water expansion and contraction vary spatially across the Prairie Pothole Region (PPR and adjacent Northern Prairie (NP in the United States, and (2 explore how landscape characteristics influence the relationship between climate inputs and surface water dynamics. Due to differences in glacial history, the PPR and NP show distinct patterns in regards to drainage development and wetland density, together providing a diversity of conditions to examine surface water dynamics. We used Landsat imagery to characterize variability in surface water extent across 11 Landsat path/rows representing the PPR and NP (images spanned 1985–2015. The PPR not only experienced a 2.6-fold greater surface water extent under median conditions relative to the NP, but also showed a 3.4-fold greater change in surface water extent between drought and deluge conditions. The relationship between surface water extent and accumulated water availability (precipitation minus potential evapotranspiration was quantified per watershed and statistically related to variables representing hydrology-related landscape characteristics (e.g., infiltration capacity, surface storage capacity, stream density. To investigate the influence stream connectivity has on the rate at which surface water leaves a given location, we modeled stream-connected and stream-disconnected surface water separately. Stream-connected surface water showed a greater expansion with wetter climatic conditions in landscapes with greater total wetland area, but lower total wetland density. Disconnected surface water showed a greater expansion with wetter climatic conditions in landscapes with higher wetland density, lower infiltration and less

  11. Wetlands inform how climate extremes influence surface water expansion and contraction

    Science.gov (United States)

    Vanderhoof, Melanie K.; Lane, Charles R.; McManus, Michael G.; Alexander, Laurie C.; Christensen, Jay R.

    2018-03-01

    Effective monitoring and prediction of flood and drought events requires an improved understanding of how and why surface water expansion and contraction in response to climate varies across space. This paper sought to (1) quantify how interannual patterns of surface water expansion and contraction vary spatially across the Prairie Pothole Region (PPR) and adjacent Northern Prairie (NP) in the United States, and (2) explore how landscape characteristics influence the relationship between climate inputs and surface water dynamics. Due to differences in glacial history, the PPR and NP show distinct patterns in regards to drainage development and wetland density, together providing a diversity of conditions to examine surface water dynamics. We used Landsat imagery to characterize variability in surface water extent across 11 Landsat path/rows representing the PPR and NP (images spanned 1985-2015). The PPR not only experienced a 2.6-fold greater surface water extent under median conditions relative to the NP, but also showed a 3.4-fold greater change in surface water extent between drought and deluge conditions. The relationship between surface water extent and accumulated water availability (precipitation minus potential evapotranspiration) was quantified per watershed and statistically related to variables representing hydrology-related landscape characteristics (e.g., infiltration capacity, surface storage capacity, stream density). To investigate the influence stream connectivity has on the rate at which surface water leaves a given location, we modeled stream-connected and stream-disconnected surface water separately. Stream-connected surface water showed a greater expansion with wetter climatic conditions in landscapes with greater total wetland area, but lower total wetland density. Disconnected surface water showed a greater expansion with wetter climatic conditions in landscapes with higher wetland density, lower infiltration and less anthropogenic drainage

  12. Wetlands inform how climate extremes influence surface water expansion and contraction

    Science.gov (United States)

    Vanderhoof, Melanie; Lane, Charles R.; McManus, Michael L.; Alexander, Laurie C.; Christensen, Jay R.

    2018-01-01

    Effective monitoring and prediction of flood and drought events requires an improved understanding of how and why surface water expansion and contraction in response to climate varies across space. This paper sought to (1) quantify how interannual patterns of surface water expansion and contraction vary spatially across the Prairie Pothole Region (PPR) and adjacent Northern Prairie (NP) in the United States, and (2) explore how landscape characteristics influence the relationship between climate inputs and surface water dynamics. Due to differences in glacial history, the PPR and NP show distinct patterns in regards to drainage development and wetland density, together providing a diversity of conditions to examine surface water dynamics. We used Landsat imagery to characterize variability in surface water extent across 11 Landsat path/rows representing the PPR and NP (images spanned 1985–2015). The PPR not only experienced a 2.6-fold greater surface water extent under median conditions relative to the NP, but also showed a 3.4-fold greater change in surface water extent between drought and deluge conditions. The relationship between surface water extent and accumulated water availability (precipitation minus potential evapotranspiration) was quantified per watershed and statistically related to variables representing hydrology-related landscape characteristics (e.g., infiltration capacity, surface storage capacity, stream density). To investigate the influence stream connectivity has on the rate at which surface water leaves a given location, we modeled stream-connected and stream-disconnected surface water separately. Stream-connected surface water showed a greater expansion with wetter climatic conditions in landscapes with greater total wetland area, but lower total wetland density. Disconnected surface water showed a greater expansion with wetter climatic conditions in landscapes with higher wetland density, lower infiltration and less anthropogenic

  13. Fractal characteristics of an asphaltene deposited heterogeneous surface

    International Nuclear Information System (INIS)

    Amin, J. Sayyad; Ayatollahi, Sh.; Alamdari, A.

    2009-01-01

    Several methods have been employed in recent years to investigate homogeneous surface topography based on image analysis, such as AFM (atomic force microscopy) and SEM (scanning electron microscopy). Fractal analysis of the images provides fractal dimension of the surface which is used as one of the most common surface indices. Surface topography has generally been considered to be mono-fractal. On the other hand, precipitation of organic materials on a rough surface and its irregular growth result in morphology alteration and converts a homogeneous surface to a heterogeneous one. In this case a mono-fractal description of the surface does not completely describe the nature of the altered surface. This work aims to investigate the topography alteration of a glass surface as a result of asphaltene precipitation and its growth at various pressures using a bi-fractal approach. The experimental results of the deposited surfaces were clearly indicating two regions of micro- and macro-asperities namely, surface types I and II, respectively. The fractal plots were indicative of bi-fractal behavior and for each surface type one fractal dimension was calculated. The topography information of the surfaces was obtained by two image analyses, AFM and SEM imaging techniques. Results of the bi-fractal analysis demonstrated that topography alteration in surface type II (macro-asperities) is more evident than that in surface type I (micro-asperities). Compared to surface type II, a better correlation was observed between the fractal dimensions inferred from the AFM images (D A ) and those of the SEM images (D S ) in surface type I.

  14. Attribution of observed surface humidity changes to human influence.

    Science.gov (United States)

    Willett, Katharine M; Gillett, Nathan P; Jones, Philip D; Thorne, Peter W

    2007-10-11

    Water vapour is the most important contributor to the natural greenhouse effect, and the amount of water vapour in the atmosphere is expected to increase under conditions of greenhouse-gas-induced warming, leading to a significant feedback on anthropogenic climate change. Theoretical and modelling studies predict that relative humidity will remain approximately constant at the global scale as the climate warms, leading to an increase in specific humidity. Although significant increases in surface specific humidity have been identified in several regions, and on the global scale in non-homogenized data, it has not been shown whether these changes are due to natural or human influences on climate. Here we use a new quality-controlled and homogenized gridded observational data set of surface humidity, with output from a coupled climate model, to identify and explore the causes of changes in surface specific humidity over the late twentieth century. We identify a significant global-scale increase in surface specific humidity that is attributable mainly to human influence. Specific humidity is found to have increased in response to rising temperatures, with relative humidity remaining approximately constant. These changes may have important implications, because atmospheric humidity is a key variable in determining the geographical distribution and maximum intensity of precipitation, the potential maximum intensity of tropical cyclones, and human heat stress, and has important effects on the biosphere and surface hydrology.

  15. Morphological characteristics of primary enamel surfaces versus permanent enamel surfaces: SEM digital analysis.

    Science.gov (United States)

    Lucchese, A; Storti, E

    2011-09-01

    The morphology of permanent and primary enamel surface merits further analysis. The objective of this study was to illustrate a method of SEM digital image processing able to quantify and discriminate between the morphological characteristics of primary and permanent tooth enamel. Sixteen extracted teeth, 8 primary teeth and 8 permanent teeth, kept in saline solution, were analysed. The teeth were observed under SEM. The SEM images were analysed by means of digitally processed algorithms. The two algorithms used were: Local standard deviation to measure surface roughness with the roughness index (RI); Hough's theorem to identify linear structures with the linear structure index (LSI). The SEM images of primary teeth enamel show smooth enamel with little areas of irregularity. No linear structures are apparent. The SEM images of permanent enamel show a not perfectly smooth surface; there are furrows and irregularities of variable depth and width. In the clinical practice a number of different situations require the removal of a thin layer of enamel. Only a good morphological knowledge of both permanent and primary tooth enamel gives the opportunity to identify and exploit the effects of rotary tools on enamel, thus allowing for a correct finishing technique.

  16. Wintertime land surface characteristics in climatic simulations over ...

    Indian Academy of Sciences (India)

    eastward moving low-pressure synoptic weather systems, called Western Disturbances (WDs). (Pisharoty and Desai .... Land surface processes are controlled by surface roughness and albedo. Different land surfaces will have different roughness length and albedo. Table 1 illustrates vegetation types and their correspond-.

  17. Influence of surface roughness on the friction property of textured surface

    Directory of Open Access Journals (Sweden)

    Yuankai Zhou

    2015-02-01

    Full Text Available In contrast with dimple textures, surface roughness is a texture at the micro-scale, essentially which will influence the load-bearing capacity of lubricant film. The numerical simulation was carried out to investigate the influence of surface roughness on friction property of textured surface. The lubricant film pressure was obtained using the method of computational fluid dynamics according to geometric model of round dimple, and the renormalization-group k–ε turbulent model was adopted in the computation. The numerical simulation results suggest that there is an optimum dimensionless surface roughness, and near this value, the maximum load-bearing capacity can be achieved. The load-bearing capacity is determined by the surface texture, the surface roughness, and the interaction between them. To get information of friction coefficient, the experiments were conducted. This experiment was used to evaluate the simulation. The experimental results show that for the frequency of 4 and 6 Hz, friction coefficient decreases at first and then increases with decreasing surface roughness, which indicates that there exists the optimum region of surface roughness leading to the best friction reduction effect, and it becomes larger when area fractions increase from 2% to 10%. The experimental results agree well with the simulation results.

  18. Gamma radiation influence on technological characteristics of wheat flour

    International Nuclear Information System (INIS)

    Teixeira, Christian A.H.M.; Inamura, Patricia Y.; Uehara, Vanessa B.; Mastro, Nelida L.d.

    2012-01-01

    This study aimed at determining the influence of gamma radiation on technological characteristics of wheat (Triticum sativum) flour and physical properties of pan breads made with this flour. The bread formulation included wheat flour, water, milk, salt, sugar, yeast and butter. The α-amylase activity of wheat flour irradiated with 1, 3 and 9 kGy in a Gammacell 220 (AECL), one day, five days and one month after irradiation was evaluated. Deformation force, height and weight of breads prepared with the irradiated flour were also determined. The enzymatic activity increased—reduction of falling number time—as radiation dose increased, their values being 397 s (0 kGy), 388 s (1 kGy), 343 s (3 kGy) and 293 s (9 kGy) respectively, remaining almost constant over the period of one month. Pan breads prepared with irradiated wheat flour showed increased weight. Texture analysis showed that bread made of irradiated flour presented an increase in maximum deformation force. The results indicate that wheat flour ionizing radiation processing may confer increased enzymatic activity on bread making and depending on the irradiation dose, an increase in weight, height and deformation force parameters of pan breads made of it. - Highlights: ► We study the influence of gamma radiation on wheat flour and properties of breads. ► Falling number decreased with radiation remaining almost constant up to one month. ► Ionizing radiation may confer an increase in texture parameters, weight and height on the bread.

  19. Thermal surface characteristics of coal fires 1 results of in-situ measurements

    Science.gov (United States)

    Zhang, Jianzhong; Kuenzer, Claudia

    2007-12-01

    Natural underground coal fires are fires in coal seams occurring subsurface. The fires are ignited through a process named spontaneous combustion, which occurs based on a natural reaction but is usually triggered through human interaction. Coal mining activities expose coal to the air. This leads to the exothermal oxidation of the carbon in the coal with the air's oxygen to CO 2 and - under certain circumstances - to spontaneous combustion. Coal fires occur in many countries world wide - however, currently the Chinese coal mining industry faces the biggest problems with coal fires. Coal fires destroy the valuable resource coal and furthermore lead to many environmental degradation phenomena such as the deterioration of surrounding vegetation, land subsidence and the emission of toxic gasses (CO, N 2O). They additionally contribute to the emission of green house relevant gasses such as CO 2 and CH 4 to the atmosphere. In this paper we present thermal characteristics of coal fires as measured in-situ during a field campaign to the Wuda coal fire area in south-central Inner Mongolia, China. Thermal characteristics include temperature anomaly measurements at the surface, spatial surface temperature profiles of fire areas and unaffected background areas, diurnal temperature profiles, and temperature measurements inside of coal fire induced cracks in the overlying bedrock. For all the measurements the effects of uneven solar heating through influences of slope and aspect are considered. Our findings show that coal fires result in strong or subtle thermal surface anomalies. Especially the latter can easily be influenced by heating of the surrounding background material through solar influences. Temperature variation of background rocks with different albedo, slope, aspect or vegetation cover can substantially influence the detectability of thermal anomalies. In the worst case coal fire related thermal anomalies can be completely masked by solar patterns during the daytime

  20. Motion direction influences surface segmentation in stereo transparency.

    Science.gov (United States)

    Goutcher, Ross

    2016-12-01

    To perceive multiple overlapping surfaces in the same location of the visual field (transparency), the visual system must determine which surface elements belong together, and should be integrated, and which should be kept apart. Spatial relations between surfaces, such as depth order, must also be determined. This article details two experiments examining the interaction of motion direction and disparity cues on the perception of depth order and surface segmentation in transparency. In Experiment 1, participants were presented with random-dot stereograms, where transparent planes were defined by differences in motion direction and disparity. Participants reported the direction of motion of the front surface. Results revealed marked effects of motion direction on perceived depth order. These biases interact with disparity in an additive manner, suggesting that the visual system integrates motion direction with other available cues to surface segmentation. This possibility was tested further in Experiment 2. Participants were presented with two intervals: one containing motion and disparity defined transparent planes, the other containing a volume of moving dots. Interplane disparity was varied to find thresholds for the correct identification of the transparent interval. Thresholds depended on motion direction: Thresholds were lower when disparities and directions in the transparency interval matched participants' preferred depth order, compared to conditions where disparity and direction were in conflict. These results suggest that motion direction influences the judgment of depth order even in the presence of other visual cues, and that the assignment of depth order may play an important role in segmentation.

  1. Surface plasmon resonance for detecting clenbuterol: Influence of monolayer structure

    Science.gov (United States)

    Suherman; Morita, Kinichi; Kawaguchi, Toshikazu

    2015-03-01

    Surface plasmon resonance sensor equipped with a fabricated immunosensor chip is used for detecting clenbuterol in this study. Since clenbuterol is a small analyte, indirect competitive inhibition immunoassay is employed. For fabricating the immunosurface, the Au-chip was functionalized by succinimidyl-terminated alkanethiol, and the terminal N-hydroxysuccinimide group of the self-assembled monolayer was either replaced with clenbuterol or blocked with ethanolamine. Scanning tunneling microscope experiments and electrochemical measurements depicted the domain structures of the succinimide group of succinimidyl-terminated propanethiol monolayer. The surface concentration and the orientation of succinimide group was significantly dependent on the concentration of dithiobis(succinimidyl) propionate (DSP) used in fabricating the monolayer. Furthermore, the structure of monolayer significantly influenced both the surface concentration and the orientation of clenbuterol on the sensor surface. Consequently, high coverage and standing-up configuration of clenbuterol showed high affinity for clenbuterol antibody. However, high affinity constant exhibited by the sensor surface was coupled with a low sensitivity. By contrast, lowest concentration of DSP solution (0.1 mM) used in fabricating the immunosurface showed a detection sensitivity of 3 ppt - the highest reported sensitivity for clenbuterol. For regeneration the immunosurface, 0.1 M NaOH was used and the same sensor surface could be reused for performing >100 rapid immunoreaction.

  2. An opaque surface influences the depth from the Pulfrich phenomenon.

    Science.gov (United States)

    Kham, Keetaek

    2004-01-01

    When a pendulum, swinging in a frontoparallel plane, is viewed with a neutral density filter before one eye, the pendulum bob appears to rotate in an elliptical path. This illusion, known as the Pulfrich phenomenon, was used to examine depth cue interaction in a natural environment. An opaque surface was placed behind the pendulum. This intervention put the 'Pulfrich depth' of the pendulum in conflict with the information provided by other depth cues, such as interposition, and observers reported that the 'far' part of the pendulum's Pulfrich trajectory appeared to be flat. This was not the case when the surface was transparent. If the opaque surface was placed farther behind the pendulum's physical path, the far trajectory became increasingly elliptical. These results suggest that the opaque surface influences the pendulum's depth qualitatively and quantitatively. That is, the depth order between the surface and the pendulum is determined by interposition, but the absolute depth of the pendulum's Pulfrich trajectory is constrained by the surface's depth.

  3. Factors influencing hysteresis characteristics of concrete dam deformation

    Directory of Open Access Journals (Sweden)

    Jia-he Zhang

    2017-04-01

    Full Text Available Thermal deformation of a concrete dam changes periodically, and its variation lags behind the air temperature variation. The lag, known as the hysteresis time, is generally attributed to the low velocity of heat conduction in concrete, but this explanation is not entirely sufficient. In this paper, analytical solutions of displacement hysteresis time for a cantilever beam and an arch ring are derived. The influence of different factors on the displacement hysteresis time was examined. A finite element model was used to verify the reliability of the theoretical analytical solutions. The following conclusions are reached: (1 the hysteresis time of the mean temperature is longer than that of the linearly distributed temperature difference; (2 the dam type has a large impact on the displacement hysteresis time, and the hysteresis time of the horizontal displacement of an arch dam is longer than that of a gravity dam; (3 the reservoir water temperature variation lags behind of the air temperature variation, which intensifies the differences in the horizontal displacement hysteresis time between the gravity dam and the arch dam; (4 with a decrease in elevation, the horizontal displacement hysteresis time of a gravity dam tends to increase, whereas the horizontal displacement hysteresis time of an arch dam is likely to increase initially, and then decrease; and (5 along the width of the dam, the horizontal displacement hysteresis time of a gravity dam decreases as a whole, while the horizontal displacement hysteresis time of an arch dam is shorter near the center and longer near dam surfaces.

  4. The influence of adherent surface preparation on bond durability

    International Nuclear Information System (INIS)

    Rider, A.N.; Arnott, D.R.; Olsson-Jacques, C.L.

    1999-01-01

    Full text: One of the major factors limiting the use of adhesive bonding is the problem associated with the production of adhesive joints that can maintain their initial strength over long periods of time in hostile environments. It is well known that the adherent surface preparation method is critical to the formation of a durable adhesive bond. Work presented in this paper focuses on the critical aspects of the surface preparation of aluminium employed for the manufacture of aluminium-epoxy joints. The surface preparation procedure examined is currently employed by the RAAF for repairs requiring metal to adhesive bonding. The influence of each step in the surface preparation on the ultimate bond durability performance of the adhesive joint is examined by a combination of methods. Double cantilever wedge style adhesive joints are loaded in mode 1 opening and then exposed to a humid environment. X-ray photoelectron spectroscopy (XPS) and contact angle measurements of the aluminium adherent before bonding provides information about the adherent surface chemistry. XPS is also employed to analyse the surfaces of the bonded specimens post failure to establish the locus of fracture. This approach provides important information regarding the properties influencing bond durability as well as the bond failure mechanisms. A two step bond degradation model was developed to qualitatively describe the observed bond durability performance and fracture data. The first step involves controlled moisture ingress by stress induced microporosity of the adhesive in the interfacial region. The second step determines the locus of fracture through the relative dominance of one of three competitive processes, viz: oxide degradation, polymer desorption, or polymer degradation. A key element of the model is the control exercised over the interfacial microporosity by the combined interaction of stress and the relative densities of strong and weak linkages at the metal to adhesive interface

  5. Polyurethane-based microparticles: formulation and influence of processes variables on its characteristics.

    Science.gov (United States)

    Campos, Elisa; Cordeiro, Rosemeyre; Alves, Patrícia; Rasteiro, M G; Gil, M H

    2008-05-01

    This study reports the development of polyurethane-based microparticles and the influence of some processes variables on its characteristics. These microparticles were prepared by emulsion polymerization, using poly(caprolactone) diol (PCL) and poly(propylene glycol), tolylene 2,4-diisocyanate terminated (TDI) or poly(propylene oxide)-based tri-isocyanated pre-polymer (TI). The reaction of polymerization was confirmed by attenuated total internal reflection Fourier transformed infrared spectroscopy (ATR-FTIR). Their thermal characteristics were investigated by dynamical mechanical thermal analysis (DMTA) and thermogravimetric analysis (TGA). For good microparticles formation, formulation 80/20 (mass ratio isocyanate/PCL) was the most indicated. Their spherical shape and smooth surface were observed by optical and scanning electron microscopy (SEM). Zeta potential measurements suggest that ionized carbonyl groups existent at the surface can be responsible for the negative potentials obtained. Respecting size and size distribution of the particles, measured by laser diffraction spectroscopy (LDS), the stirring speed and type were the process variables that most influenced it.

  6. Skin Friction Reduction Characteristics of Nonsmooth Surfaces Inspired by the Shapes of Barchan Dunes

    Directory of Open Access Journals (Sweden)

    Xiao-wen Song

    2017-01-01

    Full Text Available A new type of nonsmooth surface inspired by the shape of barchan dunes has been proposed and is intended to reduce skin friction, a major cause of overall drag. Simulations were carried out to obtain skin friction reduction characteristics for the nonsmooth surface using the commercial computational fluid dynamics software Fluent. A realizable k-ε model was employed to assess the influence of the nonsmooth structure on turbulent flow and velocity fields. The numerical simulation results showed that the new nonsmooth surface possesses the desired skin friction reduction effect and that the maximum skin friction reduction percentage reached 33.63% at a fluid speed of 30 m/s. Various aspects of the skin friction reduction mechanism were discussed, including the distribution of velocity vectors and shear stress contours and the variations in boundary layer thickness. The accuracy of the flow field for the nonsmooth unit was further verified by particle image velocimetry test results. The new bionic nonsmooth surface, which exceeds the limitations of existing nonsmooth bionic structures, can effectively reduce skin friction and should provide insights into engineering applications in the future.

  7. Surface Modified Characteristics of the Tetracalcium Phosphate as Light-Cured Composite Resin Fillers

    Directory of Open Access Journals (Sweden)

    Wen-Cheng Chen

    2014-01-01

    Full Text Available The objectives of this study are to characterize the properties of light-cured composite resins that are reinforced with whisker surface-modified particles of tetracalcium phosphate (TTCP and to investigate the influence of thermal cycling on the reinforced composites properties. The characteristics of ultimate diametral tensile strength (DTS, moduli, pH values, and fracture surfaces of the samples with different amounts of surface-modified TTCP (30%–60% were determined before and after thermal cycling between 5°C and 55°C in deionized water for 600 cycles. The trends of all groups were ductile prior to thermal cycling and the moduli of all groups increased after thermal cycling. The ductile property of the control group without filler was not significantly affected. Larger amounts of fillers caused the particles to aggregate, subsequently decreasing the resin’s ability to disperse external forces and leading to brittleness after thermal cycling. Therefore, the trend of composite resins with larger amounts of filler would become more brittle and exhibited higher moduli after thermal cycling. This developed composite resin with surface modified-TTCP fillers has the potential to be successful dental restorative materials.

  8. Surface characteristics and bioactivity of a novel natural HA/zircon nanocomposite coated on dental implants.

    Science.gov (United States)

    Karamian, Ebrahim; Khandan, Amirsalar; Motamedi, Mahmood Reza Kalantar; Mirmohammadi, Hesam

    2014-01-01

    The surface characteristics of implant which influence the speed and strength of osseointegration include surface chemistry, crystal structure and crystallinity, roughness, strain hardening, and presence of impurities. The aim of this study was to evaluate the bioactivity and roughness of a novel natural hydroxyapatite/zircon (NHA/zircon) nanobiocomposite, coated on 316L stainless steel (SS) soaked in simulated body fluid (SBF). NHA/zircon nanobiocomposite was fabricated with 0 wt.%, 5 wt.%, 10 wt.%, and 15 wt.% of zircon in NHA using ball mill for 20 minutes. The composite mixture was coated on 316L SS using plasma spray method. The results are estimated using the scanning electron microscopy (SEM) observation to evaluate surface morphology, X-ray diffraction (XRD) to analyze phase composition, and transmission electron microscopy (TEM) technique to evaluate the shape and size of prepared NHA. Surfaces roughness tester was performed to characterize the coated nanocomposite samples. The maximum average R a (14.54 μm) was found in the NHA 10 wt.% of zircon coating. In addition, crystallinity (X c ) was measured by XRD data, which indicated the minimum value (X c = 41.1%) for the sample containing 10 wt.% of zircon. Maximum bioactivity occurred in the sample containing 10 wt.% of zircon, which was due to two reasons: first, the maximum roughness and, second, the minimum crystallinity of nanobiocomposite coating.

  9. A Facile Method to Modify the Characteristics and Corrosion Behavior of 304 Stainless Steel by Surface Nanostructuring toward Biomedical Applications.

    Science.gov (United States)

    Thangaraj, Balusamy; Nellaiappan, Sankara Narayanan T S; Kulandaivelu, Ravichandran; Lee, Min Ho; Nishimura, Toshiyasu

    2015-08-19

    The study addresses how surface nanostructuring of AISI 304 stainless steel (SS) by surface mechanical attrition treatment (SMAT) influences its characteristic properties and corrosion behavior in Ringer's solution. SMAT of 304 SS induced plastic deformation, enabled surface nanocrystallization, refined the grain size, transformed the austenite phase to strain induced α'-martensite phase, increased the surface roughness, induced defects/dislocations, imparted compressive residual stresses at the surface, decreased the contact angle, and increased surface energy. The change in properties of 304 SS following treatment using 5 and 8 mm ⌀ balls for 15, 30, 45, and 60 min has caused a deleterious influence on its corrosion resistance in Ringer's solution, while an improvement in corrosion behavior is observed for those treated using 2 mm ⌀ balls. The increase in surface roughness, transformation of the austenite to α'-martensite phase, a higher extent of deformation, and the presence of larger number of defects/dislocations are main factors responsible for the lower corrosion resistance observed for 304 SS treated using 5 and 8 mm ⌀ balls in Ringer's solution. In spite of having these attributes with a relatively lower extent, 304 SS treated using 2 mm ⌀ balls offered a better corrosion resistance and exhibits a better passivity. For those treated using 2 mm ⌀ balls, the ability of the nanocrystalline surface to promote passivation outweighs the deleterious influences caused by the limited amount of deformation and defects/dislocations. Based on the findings of this study, it is recommend that SMAT of 304 SS using 2 mm ⌀ balls for 15-30 min is the optimum condition to achieve the suitable surface profile, surface characteristics with better corrosion resistance.

  10. Do leaf surface characteristics affect Agrobacterium infection in tea ...

    Indian Academy of Sciences (India)

    Unknown

    tive to the epidermis for horizontally positioned leaf discs and criteria for judging surface wettability were based on those of Crisp (1963), where θ 130 as a non-wettable surface. 2.3 Estimation of epicuticular wax and total phenols. Epicuticular wax content was estimated according to. Barnes et al ...

  11. Influence of radioactivity on surface charging and aggregation kinetics of particles in the atmosphere.

    Science.gov (United States)

    Kim, Yong-Ha; Yiacoumi, Sotira; Lee, Ida; McFarlane, Joanna; Tsouris, Costas

    2014-01-01

    Radioactivity can influence surface interactions, but its effects on particle aggregation kinetics have not been included in transport modeling of radioactive particles. In this research, experimental and theoretical studies have been performed to investigate the influence of radioactivity on surface charging and aggregation kinetics of radioactive particles in the atmosphere. Radioactivity-induced charging mechanisms have been investigated at the microscopic level, and heterogeneous surface potential caused by radioactivity is reported. The radioactivity-induced surface charging is highly influenced by several parameters, such as rate and type of radioactive decay. A population balance model, including interparticle forces, has been employed to study the effects of radioactivity on particle aggregation kinetics in air. It has been found that radioactivity can hinder aggregation of particles because of similar surface charging caused by the decay process. Experimental and theoretical studies provide useful insights into the understanding of transport characteristics of radioactive particles emitted from severe nuclear events, such as the recent accident of Fukushima or deliberate explosions of radiological devices.

  12. Influence of Microalgae onto submerged surfaces on Fouling

    Science.gov (United States)

    Kong, M.; Eom, C.; Yoon, B.; Yoon, H.; Kim, B.; Chung, K.

    2012-12-01

    Lots of algae together with organic matter deposited on the submerged surface can be easily observed occurring in the shallower water along the coast. This is mainly because only those organisms with the ability to adapt to the new situations created by man can firmly adhere enough to avoid being washed off. Chemical and microbiological characteristics of the fouling microalgae developed on various surfaces in contact with the seawater were made. The microbial compositions of the microalgae formed on the submerged surfaces were tested for. The quantities of the diverse microalgae in the samples developed on the prohibiting submerged surface were larger when there was no concern about materials for special selection for fouling. To confirm formation of microalgae on adsorbents was done SEM-EDS (Scanning Electron Microscope-Spectrometer) analysis. Microbial identified using optical microscope. In addition to, we quantified attaching microalgae as pass time. Experiment results, ten species which are Nitzshhia sp., Eucampia sp., Coscinodiscus sp., Licmophora sp., Rhizosolenia sp., Cylindrotheca sp., Striateela sp., Thalassionema sp., Guinardia sp., and Helicostomella sp. discovered to reservoir formed biofouling. They showed the important role microbial activity in fouling and corrosion of the surfaces in contact with the any seawater.

  13. Influence of surface charge on lysozyme adsorption to ceria nanoparticles

    International Nuclear Information System (INIS)

    Wang Binghui; Wu Peng; Yokel, Robert A.; Grulke, Eric A.

    2012-01-01

    Understanding mechanisms for forming protein coronas on nanomaterial surfaces is essential to designing drug delivery systems and designing and interpreting the results of nanomaterial toxicity tests. The study reports the adsorption behavior of a positively charged protein, lysozyme, on cerium dioxide (ceria) nanoparticles with three different surface charges. Adsorption isotherms were modeled with the Toth and Sips equations. Isotherm loading levels were compared to monolayer coverage estimate for ‘side-on’ and ‘end-on’ lysozyme orientations as well as random packing (jamming) and maximum packing limits. Evaluation of adsorption site energy distributions (generated using the model coefficients) suggested that the negatively charged ceria surface had a very broad site energy distribution and that its surface heterogeneity controls the adsorption process. By contrast, the adsorption of lysozyme on the positively charged nanoparticles appears to be influenced by lateral effects from adsorbed protein species. The results illustrate the importance of nanoparticle surface chemistry to protein adsorption. The modeling and site energy distribution evaluations may be useful for interpreting the formation of protein coronas on nanoparticles.

  14. Effects of pavement surface texture on noise and frictional characteristics.

    Science.gov (United States)

    1987-02-01

    An experimental modification of the transverse groove : surface texture of a section of an urban interstate highway was : performed by the Iowa Department of Transportation. Transverse : groove texturing is a design feature required by the Federal : ...

  15. Acid-base characteristics of powdered-activated-carbon surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Reed, B.E. (West Virginia Univ., Morgantown (United States)); Jensen, J.N.; Matsumoto, M.R. (State Univ. of New York, Buffalo (United States))

    Adsorption of heavy metals onto activated carbon has been described using the surface-complex-formation (SCF) model, a chemical equilibrium model. The SCF model requires a knowledge of the amphoteric nature of activated carbon prior to metal adsorption modeling. In the past, a single-diprotic-acid-site model had been employed to describe the amphoteric nature of activated-carbon surfaces. During this study, the amphoteric nature of two powdered activated carbons were investigated, and a three-monoprotic site surface model was found to be a plausible alternative. The single-diprotic-acid-site and two-monoprotic-site models did not describe the acid-base behavior of the two carbons studied adequately. The two-diprotic site was acceptable for only one of the study carbons. The acid-base behavior of activated carbon surfaces seem to be best modeled as a series of weak monoprotic acids.

  16. Unsupervised Classification of Mercury's Surface Spectral and Chemical Characteristics

    Science.gov (United States)

    D'Amore, M.; Helbert, J.; Ferrari, S.; Maturilli, A.; Nittler, L. R.; Domingue, D. L.; Vilas, F.; Weider, S. Z.; Starr, R. D.; Crapster-Pregont, E. J.; Ebel, D. S.; Solomon, S. C.

    2014-12-01

    The spectral reflectance of Mercury's surface has been mapped in the 400-1145 nm wavelength range by the Mercury Atmospheric and Surface Composition Spectrometer (MASCS) instrument during orbital observations by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft. Under the hypothesis that surface compositional information can be efficiently derived from such spectral measurements with the use of statistical techniques, we have conducted unsupervised hierarchical clustering analyses to identify and characterize spectral units from MASCS observations. The results display a large-scale dichotomy, with two spectrally distinct units: polar and equatorial, possibly linked to differences in surface environment or composition. The spatial extent of the polar unit in the northern hemisphere correlates approximately with that of the northern volcanic plains. To explore possible relations between composition and spectral behavior, we have compared the spectral units with elemental abundance maps derived from MESSENGER's X-Ray Spectrometer (XRS). It is important to note that the mapping coverage for XRS differs from that of MASCS, particularly for the heavy elements. Nonetheless, by comparing the visible and near-infrared MASCS and XRS datasets and investigating the links between them, we seek further clues to the formation and evolution of Mercury's crust. Moreover, the methodology will permit automation of the production of new maps of the spectral and chemical signature of the surface.

  17. The relative influence of road characteristics and habitat on adjacent lizard populations in arid shrublands

    Science.gov (United States)

    Hubbard, Kaylan A.; Chalfoun, Anna D.; Gerow, Kenneth G.

    2016-01-01

    As road networks continue to expand globally, indirect impacts to adjacent wildlife populations remain largely unknown. Simultaneously, reptile populations are declining worldwide and anthropogenic habitat loss and fragmentation are frequently cited causes. We evaluated the relative influence of three different road characteristics (surface treatment, width, and traffic volume) and habitat features on adjacent populations of Northern Sagebrush Lizards (Sceloporus graciosus graciosus), Plateau Fence Lizards (S. tristichus), and Greater Short-Horned Lizards (Phrynosoma hernandesi) in mixed arid shrubland habitats in southwest Wyoming. Neither odds of lizard presence nor relative abundance was significantly related to any of the assessed road characteristics, although there was a trend for higher Sceloporus spp. abundance adjacent to paved roads. Sceloporus spp. relative abundance did not vary systematically with distance to the nearest road. Rather, both Sceloporus spp. and Greater Short-Horned Lizards were associated strongly with particular habitat characteristics adjacent to roads. Sceloporus spp. presence and relative abundance increased with rock cover, relative abundance was associated positively with shrub cover, and presence was associated negatively with grass cover. Greater Short-Horned Lizard presence increased with bare ground and decreased marginally with shrub cover. Our results suggest that habitat attributes are stronger correlates of lizard presence and relative abundance than individual characteristics of adjacent roads, at least in our system. Therefore, an effective conservation approach for these species may be to consider the landscape through which new roads and their associated development would occur, and the impact that placement could have on fragment size and key habitat elements.

  18. Influence of Ecological Factors on Estimation of Impervious Surface Area Using Landsat 8 Imagery

    Directory of Open Access Journals (Sweden)

    Yuqiu Jia

    2017-07-01

    Full Text Available Estimation of impervious surface area is important to the study of urban environments and social development, but surface characteristics, as well as the temporal, spectral, and spatial resolutions of remote sensing images, influence the estimation accuracy. To investigate the effects of regional environmental characteristics on the estimation of impervious surface area, we divided China into seven sub-regions based on climate, soil type, feature complexity, and vegetation phenology: arid and semi-arid areas, Huang-Huai-Hai winter wheat production areas, typical temperate regions, the Pearl River Delta, the middle and lower reaches of the Yangtze River, typical tropical and subtropical regions, and the Qinghai Tibet Plateau. Impervious surface area was estimated from Landsat 8 images of five typical cities, including Yinchuan, Shijiazhuang, Shenyang, Ningbo, and Kunming. Using the linear spectral unmixing method, impervious and permeable surface areas were determined at the pixel-scale based on end-member proportions. We calculated the producer’s accuracy, user’s accuracy, and overall accuracy to assess the estimation accuracy, and compared the accuracies among images acquired from different seasons and locations. In tropical and subtropical regions, vegetation canopies can confound the identification of impervious surfaces and, thus, images acquired in winter, early spring, and autumn are most suitable; estimations in the Pearl River Delta, the middle and lower reaches of the Yangtze River are influenced by soil, vegetation phenology, vegetation canopy, and water, and images acquired in spring, summer, and autumn provide the best results; in typical temperate areas, images acquired from spring to autumn are most effective for estimations; in winter wheat-growing areas, images acquired throughout the year are suitable; and in arid and semi-arid areas, summer and early autumn, during which vegetation is abundant, are the optimal seasons for

  19. Numerical Analysis of Aerodynamic Characteristics of the Finned Surfaces with Cross-inclined Fins

    Directory of Open Access Journals (Sweden)

    Lagutin A. E.

    2016-12-01

    Full Text Available This paper presents results of numerical research and analyses air-side hydraulic performance of tube bundles with cross inclined fins. The numerical simulation of the fin-tube heat exchanger was performed using the Comsol Femlab software. The results of modeling show the influence of fin inclination angle and tube pitch on hydraulic characteristics of finned surfaces. A series of numerical tests were carried out for tube bundles with different inclination angles (γ =900, 850, 650, 60, the fin pitch u=4 mm. The results indicate that tube bundles with cross inclined fins can significantly enhance the average integral value of the air flow rate in channel between fins in comparison with conventional straight fins. Aerodynamic processes on both sides of modificated channel between inclined fins were analyzed. The verification procedures for received results of numerical modeling with experimental data were performed.

  20. Dynamic and reversible surface topography influences cell morphology.

    Science.gov (United States)

    Kiang, Jennifer D; Wen, Jessica H; del Álamo, Juan C; Engler, Adam J

    2013-08-01

    Microscale and nanoscale surface topography changes can influence cell functions, including morphology. Although in vitro responses to static topography are novel, cells in vivo constantly remodel topography. To better understand how cells respond to changes in topography over time, we developed a soft polyacrylamide hydrogel with magnetic nickel microwires randomly oriented in the surface of the material. Varying the magnetic field around the microwires reversibly induced their alignment with the direction of the field, causing the smooth hydrogel surface to develop small wrinkles; changes in surface roughness, ΔRRMS , ranged from 0.05 to 0.70 μm and could be oscillated without hydrogel creep. Vascular smooth muscle cell morphology was assessed when exposed to acute and dynamic topography changes. Area and shape changes occurred when an acute topographical change was imposed for substrates exceeding roughness of 0.2 μm, but longer-term oscillating topography did not produce significant changes in morphology irrespective of wire stiffness. These data imply that cells may be able to use topography changes to transmit signals as they respond immediately to changes in roughness. Copyright © 2013 Wiley Periodicals, Inc.

  1. Influence of surface vacancy defects on the carburisation of Fe 110 surface by carbon monoxide

    International Nuclear Information System (INIS)

    Chakrabarty, Aurab; Bouhali, Othmane; Mousseau, Normand; Becquart, Charlotte S.; El-Mellouhi, Fedwa

    2016-01-01

    Adsorption and dissociation of gaseous carbon monoxide (CO) on metal surfaces is one of the most frequently occurring processes of carburisation, known as primary initiator of metal dusting corrosion. Among the various factors that can significantly influence the carburisation process are the intrinsic surface defects such as single surface vacancies occurring at high concentrations due to their low formation energy. Intuitively, adsorption and dissociation barriers of CO are expected to be lowered in the vicinity of a surface vacancy, due to the strong attractive interaction between the vacancy and the C atom. Here the adsorption energies and dissociation pathways of CO on clean and defective Fe 110 surface are explored by means of density functional theory. Interestingly, we find that the O adatom, resulting from the CO dissociation, is unstable in the electron-deficit neighbourhood of the vacancy due to its large electron affinity, and raises the barrier of the carburisation pathway. Still, a full comparative study between the clean surface and the vacancy-defected surface reveals that the complete process of carburisation, starting from adsorption to subsurface diffusion of C, is more favourable in the vicinity of a vacancy defect.

  2. Surface characteristics of chitin-based shape memory polyurethane elastomers.

    Science.gov (United States)

    Zia, Khalid Mahmood; Zuber, Mohammad; Barikani, Mehdi; Bhatti, Ijaz Ahmad; Khan, Mohammad Bilal

    2009-09-01

    Shape memory polyurethanes (SMPUs) were prepared from polycaprolactone diol 4000 (PCL 4000), 1,4-butanediol (BDO), chitin, dimethylol propionic acid (DMPA), triethylamine (TEA) and 4,4'-diphenylmethane diisocyanate (MDI), and the structures of the synthesized materials were verified by infrared spectroscopy. The effects of chitin and DMPA contents in the polyurethane formulation on surface properties were investigated. DMPA provides function of making hydrophilic polyurethanes. The crystalline structure of chitin enhanced the hydrophobicity of the synthesized materials. Contact angle, water absorption, surface free energy, work of water adhesion and swelling behavior of the synthesized polyurethanes were affected by varying the DMPA and chitin contents. The interactions of the PU films with solvents on the surface were clearly related to the contents of DMPA and chitin in the final polyurethane formulation.

  3. Physico-chemical characteristics of surface and groundwater in ...

    African Journals Online (AJOL)

    musa kizito ojochenemi

    and bicarbonate water type which represents recently recharged water of meteoric origin that resulted from the dissolution of alluminosilicate minerals. Comparison of the chemical characteristic of groundwater in Obajana and its environs, and the. WHO/SON baseline standard for drinking water quality confirms that at the ...

  4. Resonant characteristics and sensitivity dependency on the contact surface in QCM-micropillar-based system of coupled resonator sensors

    International Nuclear Information System (INIS)

    Kashan, M A M; Kalavally, V; Ramakrishnan, N; Lee, H W

    2016-01-01

    We report the characteristics and sensitivity dependence over the contact surface in coupled resonating sensors (CRSs) made of high aspect ratio resonant micropillars attached to a quartz crystal microbalance (QCM). Through experiments and simulation, we observed that when the pillars of resonant heights were placed in maximum displacement regions the resonance frequency of the QCM increased following the coupled resonance characteristics, as the pillar offered elastic loading to the QCM surface. However, the same pillars when placed in relatively lower displacement regions, in spite of their resonant dimension, offered inertial loading and resulted in a decrease in QCM resonance frequency, as the displacement amplitude was insufficient to couple the vibrations from the QCM to the pillars. Accordingly, we discovered that the coupled resonance characteristics not only depend on the resonant structure dimensions but also on the contact regions in the acoustic device. Further analysis revealed that acoustic pressure at the contact surface also influences the resonance frequency characteristics and sensitivity of the CRS. To demonstrate the significance of the present finding for sensing applications, humidity sensing is considered as the example measurand. When a sensing medium made of resonant SU-8 pillars was placed in a maximum displacement region on a QCM surface, the sensitivity increased by 14 times in comparison to a resonant sensing medium placed in a lower displacement region of a QCM surface. (paper)

  5. Resonant characteristics and sensitivity dependency on the contact surface in QCM-micropillar-based system of coupled resonator sensors

    Science.gov (United States)

    Kashan, M. A. M.; Kalavally, V.; Lee, H. W.; Ramakrishnan, N.

    2016-05-01

    We report the characteristics and sensitivity dependence over the contact surface in coupled resonating sensors (CRSs) made of high aspect ratio resonant micropillars attached to a quartz crystal microbalance (QCM). Through experiments and simulation, we observed that when the pillars of resonant heights were placed in maximum displacement regions the resonance frequency of the QCM increased following the coupled resonance characteristics, as the pillar offered elastic loading to the QCM surface. However, the same pillars when placed in relatively lower displacement regions, in spite of their resonant dimension, offered inertial loading and resulted in a decrease in QCM resonance frequency, as the displacement amplitude was insufficient to couple the vibrations from the QCM to the pillars. Accordingly, we discovered that the coupled resonance characteristics not only depend on the resonant structure dimensions but also on the contact regions in the acoustic device. Further analysis revealed that acoustic pressure at the contact surface also influences the resonance frequency characteristics and sensitivity of the CRS. To demonstrate the significance of the present finding for sensing applications, humidity sensing is considered as the example measurand. When a sensing medium made of resonant SU-8 pillars was placed in a maximum displacement region on a QCM surface, the sensitivity increased by 14 times in comparison to a resonant sensing medium placed in a lower displacement region of a QCM surface.

  6. SURFACE FAULT CHARACTERISTICS OF THE 1995 HYOGOKEN-NAMBU EARTHQUAKE

    OpenAIRE

    Takashi, NAKATA; Kiyoshi, YOMOGIDA; Professor, Department of Geography, Hiroshima University:Associate Professor, Department of Earth and Planetary Systems Science, Hiroshima University; Professor, Department of Geography, Hiroshima University:Associate Professor, Department of Earth and Planetary Systems Science, Hiroshima University

    1995-01-01

    Distinctive ruptures in the surface faulting that generated the destructive 1995 Hyogoken-nambu earthquake (Ms = 7.2) appeared along the Nojima fault, an active fault on the northwestern coast of Awaji Island, Japan. These surface fault ruptures extend continuously southwestward for 10 km from Ezaki lighthouse, near the epicenter to Toshima Town in Hokudan, and display prominent right-lateral off-sets of roads, paddy dikes and so on of 1.9 m maximum with vertical displacement of 1.2 m maximum...

  7. Thermal and induced flow characteristics of radio frequency surface dielectric barrier discharge plasma actuation at atmospheric pressure

    International Nuclear Information System (INIS)

    Wang Wei-long; Li Jun; Song Hui-min; Jin Di; Jia Min; Wu Yun

    2017-01-01

    Thermal and induced flow velocity characteristics of radio frequency (RF) surface dielectric barrier discharge (SDBD) plasma actuation are experimentally investigated in this paper. The spatial and temporal distributions of the dielectric surface temperature are measured with the infrared thermography at atmospheric pressure. In the spanwise direction, the highest dielectric surface temperature is acquired at the center of the high voltage electrode, while it reduces gradually along the chordwise direction. The maximum temperature of the dielectric surface raises rapidly once discharge begins. After several seconds (typically 100 s), the temperature reaches equilibrium among the actuator’s surface, plasma, and surrounding air. The maximum dielectric surface temperature is higher than that powered by an AC power supply in dozens of kHz. Influences of the duty cycle and the input frequency on the thermal characteristics are analyzed. When the duty cycle increases, the maximum dielectric surface temperature increases linearly. However, the maximum dielectric surface temperature increases nonlinearly when the input frequency varies from 0.47 MHz to 1.61 MHz. The induced flow velocity of the RF SDBD actuator is 0.25 m/s. (paper)

  8. Surface properties and field emission characteristics of chemical vapor deposition diamond grown on Fe/Si substrates

    International Nuclear Information System (INIS)

    Hirakuri, Kenji; Yokoyama, Takahiro; Enomoto, Hirofumi; Mutsukura, Nobuki; Friedbacher, Gernot

    2001-01-01

    Electron field emission characteristics of diamond grains fabricated on iron dot-patterned silicon (Fe/Si) substrates at different methane concentrations have been investigated. The characteristics of the samples could be improved by control of the methane concentration during diamond fabrication. Etching treatment of the as-grown diamond has enhanced the emission properties both with respect to current and threshold voltage. In order to study the influence of etching effects on the field emission characteristics, the respective surfaces were studied by Raman spectroscopy, Auger electron spectroscopy, and electron spectroscopy for chemical analysis (ESCA). ESCA revealed intensive graphite and FeO x peaks on the sample surface grown at high methane concentration. For the etched samples, the peaks of diamond and silicon carbide were observed, and the peaks of nondiamond carbon disappeared. The experimental results show that the etching process removes graphitic and nondiamond carbon components. [copyright] 2001 American Institute of Physics

  9. Variability in surface inversion characteristics over India in winter ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 120; Issue 1. Variability in surface inversion ... Decadal variations in inversion strength show weak inversion frequencies decreasing from the 1st to the 3rd decade while moderate/strong inversions occur more frequently at most stations. Frequencies of very strong ...

  10. Characteristics of surface wind structure of tropical cyclones over the ...

    Indian Academy of Sciences (India)

    Bessho et al. 2006) to create global satellite-only surface wind analysis. The method makes use of a variational data fitting technique on a cylindrical grid that allows variable data weights in combination with bulk quality con- trol (Knaff et al. 2007).

  11. Evaluation of surface characteristics of rotary nickel‑titanium ...

    African Journals Online (AJOL)

    Background: Instrument fracture is a serious concern in endodontic practice. Objective: The aim of this study was to investigate the surface quality of new and used rotary nickel‑titanium (NiTi) instruments manufactured by the traditional grinding process and twisting methods. Materials and Methods: Total 16 instruments of ...

  12. Evaluation of surface characteristics of rotary nickel‑titanium ...

    African Journals Online (AJOL)

    2015-05-26

    May 26, 2015 ... Background: Instrument fracture is a serious concern in endodontic practice. Objective: The aim of this study was to investigate the surface quality of new and used rotary nickel‑titanium (NiTi) instruments manufactured by the traditional grinding process and twisting methods. Materials and Methods: Total 16 ...

  13. Tyre - Road Noise, Surface Characteristics and Material Properties

    NARCIS (Netherlands)

    Li, M.

    2013-01-01

    Noise levels due to road traffic have reached intolerable high levels in and around many urban areas all around the world. Because of health reasons and reasons of well- being these noise levels have to be reduced. The noise produced from the interaction between the rolling tyre and road surface is

  14. Variability in surface inversion characteristics over India in winter ...

    Indian Academy of Sciences (India)

    a serious threat to the health of the public while reduced visibility due to fog is hazardous for avia- tion and surface transport. Therefore, knowledge of inversions may help in understanding the dispersal of pollutants and fog, both of which will immensely benefit the public at large, especially in the cities, which has expanded ...

  15. Characteristics of surface wind structure of tropical cyclones over the ...

    Indian Academy of Sciences (India)

    the effective utilization of above-mentioned multi- platform-based satellite-derived wind product is very essential to minimize the error in intensity and structure monitoring and forecast. So, a study has been undertaken to analyze the mean character- istics of surface wind distribution and hence the structure of TC based on ...

  16. Effect of Autoclave Cycles on Surface Characteristics of S-File Evaluated by Scanning Electron Microscopy

    OpenAIRE

    Razavian, Hamid; Iranmanesh, Pedram; Mojtahedi, Hamid; Nazeri, Rahman

    2015-01-01

    Introduction: Presence of surface defects in endodontic instruments can lead to unwanted complications such as instrument fracture and incomplete preparation of the canal. The current study was conducted to evaluate the effect of autoclave cycles on surface characteristics of S-File by scanning electron microscopy (SEM). Methods and Materials: In this experimental study, 17 brand new S-Files (#30) were used. The surface characteristics of the files were examined in four steps (without autocla...

  17. Measurement of fog and haze extinction characteristics and availability evaluation of free space optical link under the sea surface environment.

    Science.gov (United States)

    Wu, Xiaojun; Wang, Hongxing; Song, Bo

    2015-02-10

    Fog and haze can lead to changes in extinction characteristics. Therefore, the performance of the free space optical link is highly influenced by severe weather conditions. Considering the influential behavior of weather conditions, a state-of-the-art solution for the observation of fog and haze over the sea surface is presented in this paper. A Mie scattering laser radar, with a wavelength of 532 nm, is used to observe the weather conditions of the sea surface environment. The horizontal extinction coefficients and visibilities are obtained from the observation data, and the results are presented in the paper. The changes in the characteristics of extinction coefficients and visibilities are analyzed based on both the short-term (6 days) severe weather data and long-term (6 months) data. Finally, the availability performance of the free space optical communication link is evaluated under the sea surface environment.

  18. Influence of oxidant and fuel on the powder characteristics of ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 40; Issue 1. Influence of ... Although the LiNbO3 synthesis by combustion method has been investigated with particular attention recently, the influence of oxidants and different fuels' sources on the synthesized powders has not yet been thoroughly studied. In this work ...

  19. Mars radar clutter and surface roughness characteristics from MARSIS data

    Science.gov (United States)

    Campbell, Bruce A.; Schroeder, Dustin M.; Whitten, Jennifer L.

    2018-01-01

    Radar sounder studies of icy, sedimentary, and volcanic settings can be affected by reflections from surface topography surrounding the sensor nadir location. These off-nadir ;clutter; returns appear at similar time delays to subsurface echoes and complicate geologic interpretation. Additionally, broadening of the radar echo in delay by surface returns sets a limit on the detectability of subsurface interfaces. We use MARSIS 4 MHz data to study variations in the nadir and off-nadir clutter echoes, from about 300 km to 1000 km altitude, R, for a wide range of surface roughness. This analysis uses a new method of characterizing ionospheric attenuation to merge observations over a range of solar zenith angle and date. Mirror-like reflections should scale as R-2, but the observed 4 MHz nadir echoes often decline by a somewhat smaller power-law factor because MARSIS on-board processing increases the number of summed pulses with altitude. Prior predictions of the contributions from clutter suggest a steeper decline with R than the nadir echoes, but in very rough areas the ratio of off-nadir returns to nadir echoes shows instead an increase of about R1/2 with altitude. This is likely due in part to an increase in backscatter from the surface as the radar incidence angle at some round-trip time delay declines with increasing R. It is possible that nadir and clutter echo properties in other planetary sounding observations, including RIME and REASON flyby data for Europa, will vary in the same way with altitude, but there may be differences in the nature and scale of target roughness (e.g., icy versus rocky surfaces). We present global maps of the ionosphere- and altitude-corrected nadir echo strength, and of a ;clutter; parameter based on the ratio of off-nadir to nadir echoes. The clutter map offers a view of surface roughness at ∼75 m length scale, bridging the spatial-scale gap between SHARAD roughness estimates and MOLA-derived parameters.

  20. Influence of milling process in the surface energy of glass tile frits

    International Nuclear Information System (INIS)

    Tamayo, A.; Rubio, F.; Otero, J. L.; Rubio, J.

    2013-01-01

    In this work has been studied the influence of the milling process of two ceramic frits used in the ceramic tile industry. Both glass frits were of similar chemical composition changing SiO 2 by 5% of B 2 O 3 and both of them were water or dry milled. Glass frit surfaces were characterized by FT-IR, Karl-Fischer (K-F) titration and Inverse Gas Chromatography at Infinite Dilution (IGC-ID). By K-F titration it was observed that water milled frits presented 28 and 26 OH groups for 100 A 2 if they do not contain or contain boron, respectively. These surface changes are also observed by IGC-ID. Thus, the glass frit without boron and dry milled presented the highest dispersive surface energy (44 mJ.m - 2) and the less acidic constant (0.13 kJ.mol - 1). Both glass frits are amphoteric with acidic and base surface active sites, and that frit without boron presents the higher basicity. Milling process influences in the acid-base surface characteristics of both frits by increasing the basicity for the one without boron and increasing for the other one. This has been assigned to the different location of hydroxyl groups where the higher interaction is the one that does not contain boron and dry milled as K-F results. (Author)

  1. The influence of surface curvature on polymer behavior at inorganic surfaces

    Science.gov (United States)

    Nunnery, Grady A.

    Nanoscale surfaces were examined in order to determine the influence of surface curvature on polymer behavior at polymer-ceramic interfaces, as well as the influence of nanoparticles in cellulosic media. Poly(methyl methacrylate) and block copolymers thereof were adsorbed onto porous alumina substrates of various pore sizes in order to determine how polymer and copolymer adsorption behavior at nanoscale surfaces differs from adsorption onto flat surfaces. It was determined that chain density on concave surfaces dramatically decreases as curvature increases in much the same way that it does on convex surfaces (e.g. on the surface of nanoparticles), and physical models are provided to explain this similarity. Diblock copolymer adsorption is observed to vary dramatically with solvent quality and block asymmetry and can be correlated with the surface curvature very similarly to the adsorptive behavior of homopolymers on those same surfaces. The addition of nanoparticles to cellulosic media was investigated as a means to significantly modify the properties of cellulosic composites with minimal additions of nanoparticles. Although cellulose is among the most abundant polymers on earth, its primary uses are limited to bulk commodity goods, such as paper and textiles. This work demonstrates a simple means to control cellulosic fluid viscosity, thereby increasing the versatility of these biopolymers in additional applications with higher value-added potential. The formation of iron-cellulosic nanocomposites by the in-situ thermolysis of metal carbonyls to form metallic nanoparticles was performed and was analyzed by viscometry among other techniques. It was determined that the nanocomposites that were formed exhibited significantly increased viscosity, up to the point of gelation. Additionally, an introduction to the expansive field of nanocomposites is provided, including how and why composite properties change abruptly as filler size approaches the nanoscale. An extensive

  2. Surface characteristics changes in polymeric material by swift ion beam

    Science.gov (United States)

    Abdul-Kader, A. M.; El-Gendy, Y. A.

    2018-03-01

    In this work, polyethylene (PE) samples were subjected to 9 MeV Cl+2 ions with fluences ranging from 1 × 1013 to 5 × 1014 ion/cm2. Rutherford back scattering spectrometry (RBS), X-ray diffraction (XRD), ultraviolet-visible (UV-vis) spectroscopy and Vicker's micro-hardness (Hv) techniques were used to investigate the compositional transformation, changes in the structure, optical and surface hardness of bombarded samples. The adhesion parameters were analyzed using the contact angle measurements. The obtained results showed that the ion irradiation caused a decrease in the crystallinity of polyethylene and increase in absorption of oxygen on the polymer surface as well. The absorption edge shifted towards the red shift as Cl-ion fluence increases. It was found that the hardness and adhesion parameters increase with increasing the ion beam fluence.

  3. CYGNSS Surface Wind Validation and Characteristics in the Maritime Continent

    Science.gov (United States)

    Asharaf, S.; Waliser, D. E.; Zhang, C.; Wandala, A.

    2017-12-01

    Surface wind over tropical oceans plays a crucial role in many local/regional weather and climate processes and helps to shape the global climate system. However, there is a lack of consistent high quality observations for surface winds. The newly launched NASA Cyclone Global Navigation Satellite System (CYGNSS) mission provides near surface wind speed over the tropical ocean with sampling that accounts for the diurnal cycle. In the early phase of the mission, validation is a critical task, and over-ocean validation is typically challenging due to a lack of robust validation resources that a cover a variety of environmental conditions. In addition, it can also be challenging to obtain in-situ observation resources and also to extract co-located CYGNSS records for some of the more scientifically interesting regions, such as the Maritime Continent (MC). The MC is regarded as a key tropical driver for the mean global circulation as well as important large-scale circulation variability such as the Madian-Julian Oscillation (MJO). The focus of this project and analysis is to take advantage of local in-situ resources from the MC regions (e.g. volunteer shipping, marine buoys, and the Year of Maritime Continent (YMC) campaign) to quantitatively characterize and validate the CYGNSS derived winds in the MC region and in turn work to unravel the complex multi-scale interactions between the MJO and MC. This presentation will show preliminary results of a comparison between the CYGNSS and the in-situ surface wind measurements focusing on the MC region. Details about the validation methods, uncertainties, and planned work will be discussed in this presentation.

  4. Early Life And In Service Friction Characteristics Of Runway Surface

    OpenAIRE

    Widyatmoko, I.; Fergusson, C.

    2012-01-01

    This paper presents friction data gathered from seven regional and major international airports in the UK, covering different surface courses, from the time of installation to in service. The wet friction monitoring at these airports was carried out by using Continuous Friction Measurement Equipments (CFME) over 4 years in service. Some materials showed reduction in the wet friction values during a few days after installation but then followed by a steady increase in the values, even without ...

  5. Root surface characteristics of children teeth with periodontal diseases.

    Science.gov (United States)

    Bimstein, E; Wignall, W; Cohen, D; Katz, J

    2008-01-01

    The present study examined the root surfaces of teeth from children with or without periodontal diseases and with or without systemic diseases. Light microscopy revealed that when compared to control teeth: teeth with chronic periodontitis had similar radicular histology; teeth from children with leukocyte adhesion deficiency, Down syndrome and aggressive periodontitis had narrower cementum areas; teeth from children with hypophosphatasia showed cementum aplasia. Cementum anomalies may facilitate the establishment and progress of periodontitis in children.

  6. Influence of physical properties of activated carbons on characteristics of electric double-layer capacitors

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Mitsuhiro [FDK Corp., Shizuoka (Japan). Research and Development Div.; Nakanishi, Masanori [FDK Corp., Shizuoka (Japan). Research and Development Div.; Yamamoto, Kohei [FDK Corp., Shizuoka (Japan). Research and Development Div.

    1996-06-01

    Electrochemical characterization has been carried out for several activated carbons used as polarizable electrodes of electric double-layer capacitors in an aqueous electrolytic solution. The rest potential of the activated carbon was proportional to the logarithm of the oxygen content or to the concentration of the acidic surface functional groups of the activated carbon. The result of triangular voltage-sweep cyclic voltammetry was the same as that of the residual current measurement. The oxygen content and concentration of the acidic surface groups of activated carbon influenced the electrochemical characteristics of the activated carbon. Under anodic polarization, gas evolution was observed at the electrode surface of activated carbon with high oxygen content at 0.8 V versus saturated calomel electrode (SCE). Gas evolution was not observed at the electrode surface of activated carbon with low oxygen content even to 1.0 V versus SCE. Under cathodic polarization of activated carbon with high oxygen content, the peak was observed at approximately -0.2 V versus SCE, but there was no gas evolution at the electrode surface of the activated carbon. Bubbles were not observed at the electrode surface of activated carbon with low oxygen content at -0.5 V versus SCE. Electric double-layer capacitors were made from activated carbons used for electrochemical measurements; load-life tests have been carried out. Thickness and internal resistance of the capacitor composed of activated carbon with high oxygen content increased. The changes in thickness and internal resistance of the capacitor composed of activated carbon with low oxygen content were small. (orig.)

  7. The Influence of Job Characteristics and Self-Directed Learning Orientation on Workplace Learning

    Science.gov (United States)

    Raemdonck, Isabel; Gijbels, David; van Groen, Willemijn

    2014-01-01

    Given the increasing importance of learning at work, we set out to examine the factors which influence workplace learning behaviour. The study investigated the influence of the job characteristics from Karasek's Job Demand Control Support model and the personal characteristic self-directed learning orientation on workplace learning. A total…

  8. Altering surface characteristics of polypropylene mesh via sodium hydroxide treatment.

    Science.gov (United States)

    Regis, Shawn; Jassal, Manisha; Mukherjee, Nilay; Bayon, Yves; Scarborough, Nelson; Bhowmick, Sankha

    2012-05-01

    Incisional hernias represent a serious and common complication following laparotomy. The use of synthetic (e.g. polypropylene) meshes to aid repair of these hernias has considerably reduced recurrence rates. While polypropylene is biocompatible and has a long successful clinical history in treating hernias and preventing reherniation, this material may suffer some limitations, particularly in challenging patients at risk of wound failure due to, for example, an exaggerated inflammation reaction, delayed wound healing, and infection. Surface modification of the polypropylene mesh without sacrificing its mechanical properties, critical for hernia repair, represents one way to begin to address these clinical complications. Our hypothesis is treatment of a proprietary polypropylene mesh with sodium hydroxide (NaOH) will increase in vitro NIH/3T3 cell attachment, predictive of earlier and improved cell colonization and tissue integration of polypropylene materials. Our goal is to achieve this altered surface functionality via enhanced removal of chemicals/oils used during material synthesis without compromising the mechanical properties of the mesh. We found that NaOH treatment does not appear to compromise the mechanical strength of the material, despite roughly a 10% decrease in fiber diameter. The treatment increases in vitro NIH/3T3 cell attachment within the first 72 h and this effect is sustained up to 7 days in vitro. This research demonstrates that sodium hydroxide treatment is an efficient way to modify the surface of polypropylene hernia meshes without losing the mechanical integrity of the material. This simple procedure could also allow the attachment of a variety of biomolecules to the polypropylene mesh that may aid in reducing the complications associated with polypropylene meshes today. Copyright © 2012 Wiley Periodicals, Inc.

  9. Wavelet theory and belt finishing process, influence of wavelet shape on the surface roughness parameter values

    International Nuclear Information System (INIS)

    Khawaja, Z; Mazeran, P-E; Bigerelle, M; Guillemot, G; Mansori, M El

    2011-01-01

    This article presents a multi-scale theory based on wavelet decomposition to characterize the evolution of roughness in relation with a finishing process or an observed surface property. To verify this approach in production conditions, analyses were developed for the finishing process of the hardened steel by abrasive belts. These conditions are described by seven parameters considered in the Tagushi experimental design. The main objective of this work is to identify the most relevant roughness parameter and characteristic length allowing to assess the influence of finishing process, and to test the relevance of the measurement scale. Results show that wavelet approach allows finding this scale.

  10. Surface coating influence on elastic properties of spruce wood by means of holographic vibration mode visualization

    Science.gov (United States)

    Bongova, M.; Urgela, Stanislav

    1999-07-01

    Physicoacoustical properties of wood influenced by surface coating are studied by modal analysis. Resonant spruce plates were coated by stain, nitrocellulose varnish, special violin paint and shellac. The modal testing was performed by electronic speckle pattern interferometry. For this purpose, equipment called VIBROVIZER was used. The collected values of physicoacoustical characteristics (density, Young's modulus, acoustic constant) were compared using the graphic plots of data. The 3D plots help to evaluate wooden plates from a viewpoint of the quality control. This fact offers new opportunity for musical instrument manufacturers.

  11. Study of surface phenomena in biomaterials: The influence of physical factors

    Science.gov (United States)

    Sachelarie, Liliana; Vasiliu, Mihaela Papusa; Ciobanu, Catalina

    2015-10-01

    This study's purpose is pointing out the phenomenon that occurs at time of interaction between the tissue with implant. The materials used are Ti and its alloys. The oral tissue must be compatible with the materials used in surgical implant to human body. The bio-materials surface behavior is influenced by physical characteristics. The methods we use show a number of bio-compatibility aspects. The success of an implant in a hard tissue depends not only on the initial attachment and the osteogenic cells consecutive proliferation, but also on their capacity to create a new bone.

  12. Study of surface phenomena in biomaterials: The influence of physical factors

    Energy Technology Data Exchange (ETDEWEB)

    Sachelarie, Liliana, E-mail: lisachero@yahoo.com; Vasiliu, Mihaela Papusa; Ciobanu, Catalina

    2015-10-15

    This study's purpose is pointing out the phenomenon that occurs at time of interaction between the tissue with implant. The materials used are Ti and its alloys. The oral tissue must be compatible with the materials used in surgical implant to human body. The bio-materials surface behavior is influenced by physical characteristics. The methods we use show a number of bio-compatibility aspects. The success of an implant in a hard tissue depends not only on the initial attachment and the osteogenic cells consecutive proliferation, but also on their capacity to create a new bone.

  13. Influence of oxygen doping on resistive-switching characteristic of a-Si/c-Si device

    Science.gov (United States)

    Zhang, Jiahua; Chen, Da; Huang, Shihua

    2017-12-01

    The influence of oxygen doping on resistive-switching characteristics of Ag/a-Si/p+-c-Si device was investigated. By oxygen doping in the growth process of amorphous silicon, the device resistive-switching performances, such as the ON/OFF resistance ratios, yield and stability were improved, which may be ascribed to the significant reduction of defect density because of oxygen incorporation. The device I–V characteristics are strongly dependent on the oxygen doping concentration. As the oxygen doping concentration increases, the Si-rich device gradually transforms to an oxygen-rich device, and the device yield, switching characteristics, and stability may be improved for silver/oxygen-doped a-Si/p+-c-Si device. Finally, the device resistive-switching mechanism was analyzed. Project supported by the Zhejiang Provincial Natural Science Foundation of China (No. LY17F040001), the Open Project Program of Surface Physics Laboratory (National Key Laboratory) of Fudan University (No. KF2015_02), the Open Project Program of National Laboratory for Infrared Physics, Chinese Academy of Sciences (No. M201503), the Zhejiang Provincial Science and Technology Key Innovation Team (No. 2011R50012), and the Zhejiang Provincial Key Laboratory (No. 2013E10022).

  14. Aerodynamics characteristic of axisymmetric surface protuberance in supersonic regime

    KAUST Repository

    Qamar, Adnan

    2012-01-01

    The present work deals with the problem of an axi-symmetric surface protuberance mounted on a spherical nosed body of revolution. The numerical computations are carried out for laminar supersonic viscous flow for trapezoidal shape axi-symmetric protuberances. A free stream Mach number ranging from 3 to 8 in steps of 1 at a fixed free stream Reynolds number of 1.8x10(4) has been used in the present study. The steady solutions are obtained using a time marching approach. A newly developed Particle Velocity Upwinding (PVU) scheme has been used for the computation. The spatial flow pattern exhibits a strong bow shock in front of the hemispherical nose, which engulfs the entire base body. Near the protuberance, the fluid particle decelerates due to the adverse pressure created by the protuberance and thus the flow separates in front of the protuberance. This point of separation is found to be a function of Mach number and the protuberance shape. A low-pressure expansion region dominates the base region of the obstacle. The reattachment point for the base separation is also a function of Mach number. As the Mach number is increased the reattachment point shifts toward the protuberances base. A weak recompression shock is also seen in the base, which affects the separated zone behind the protuberance. The important design parameters such as skin friction, heat transfer, drag, and surface pressure coefficients are reported extensively.

  15. Influence of technological deviations on the basic operational characteristics of hydrodynamic bearings

    Science.gov (United States)

    Tarasevych, Y.; Savchenko, I.; Sovenko, N.

    2017-08-01

    The main purpose of this paper is to define a methodology to determine the analytical approximate closed-form expression of probabilistic characteristics of load capacity of liquid-lubricated journal bearings in the case of a steady flow regime. Influence of random change of basic geometrical parameters of journal bearings (gap value and eccentricity) on the load capacity of bearing is considered. It is shown that the actual value of hydrodynamic force in bearing can substantially differ from a calculation one. The got results confirm the necessity of application of such approach at consideration both geometrical and operating parameters of bearing, for example, axes misalignment, deviation of surface form, roughness and others, which have casual nature too.

  16. Lubrication of oral surfaces by food emulsions: the importance of surface characteristics

    NARCIS (Netherlands)

    Hoog, de E.H.A.; Prinz, J.F.; Huntjens, L.; Dresselhuis, D.M.; Aken, van G.A.

    2006-01-01

    The friction between surfaces in relative motion lubricated by food emulsions has been measured. Different types of surfaces were tested, including metal, glass, rubber, and mucosal surfaces (pig tongue and pig esophagus). We demonstrate that the load-dependent behavior of the coefficient of kinetic

  17. Lubrication of oral surfaces by food emulsions: The importance of surface characteristics

    NARCIS (Netherlands)

    Hoog, E.H.A. de; Prinz, J.F.; Huntjens, L.; Dresselhuis, D.M.; Aken, G.A. van

    2006-01-01

    The friction between surfaces in relative motion lubricated by food emulsions has been measured. Different types of surfaces were tested, including metal, glass, rubber, and mucosal surfaces (pig tongue and pig esophagus). We demonstrate that the load-dependent behavior of the coefficient of kinetic

  18. The surface heat island of Rotterdam and its relationship with urban surface characteristics

    NARCIS (Netherlands)

    Klok, L.; Zwart, S.; Verhagen, H.; Mauri, E.

    2012-01-01

    Thermal infrared high resolution satellite images from Landsat sensors were used to spatially quantify the surface heat island (SHI) of Rotterdam in the Netherlands. Based on surface temperature maps retrieved on 15 summer days since 1984, the average surface temperature of each district and

  19. Influence of feedback characteristics on perceived learning value of feedback in clerkships: does culture matter?

    OpenAIRE

    Suhoyo, Yoyo; Van Hell, Elisabeth A.; Kerdijk, Wouter; Emilia, Ova; Sch?nrock-Adema, Johanna; Kuks, Jan B. M.; Cohen-Schotanus, Janke

    2017-01-01

    Background: Various feedback characteristics have been suggested to positively influence student learning. It is not clear how these feedback characteristics contribute to students' perceived learning value of feedback in cultures classified low on the cultural dimension of individualism and high on power distance. This study was conducted to validate the influence of five feedback characteristics on students' perceived learning value of feedback in an Indonesian clerkship context. Methods: W...

  20. [Distribution characteristics and influencing factors of children with allergic rhinitis in a domestic dust mites allergens content distribution characteristics and influencing factors].

    Science.gov (United States)

    Ji, Dong; Gui, Xiaozhong; Jiang, Wanjin; Wang, Qin

    2015-03-01

    To observe the household environment dust mites allergens content distribution characteristics and influence factors of children with allergic rhinitis to dust mites in Wuhu. Collect the surface dust in bedroom and living room floor, mattresses, pillows, sofa of 102 children with allergic rhinitis families. Dust mite allergen components 1 (Der f1) and house dust mites allergens 1 components (Der p1) of the dust samples were determined by enzyme-linked immunosorbent assay (ELISA). One hundred and twenty samples were collected . In a domestic dust mites samples, with a median of M (Min and Max) said dust mite allergen levels, Der f1 and Der p1 content was 2.66 (0.03, 26.63), 3.48 (0, 03, 33.68), respectively. Der f1 was significantly less than Der p1, and the difference was statistically significant (P dust mites content of urban was significantly more than that of villages and towns, the difference was statistically significant (P dust mites allergens content in either boy's or girl's family were similar, there was no statistically significant difference (P > 0.05). The household dust mites of children allergic rhinitisin Wuhu area is given priority to with Der p1, and urban dust mites are significantly more than village's and town's. Enhancing health education, controlling dust mites allergens contamination inside the bedroom, especially urban areas, are positive differences for the prevention and treatment of allergic diseases such as allergic rhinitis in children.

  1. Influence of strain on transport characteristics of HTSC

    Science.gov (United States)

    Moroz, A. N.; Maksimova, A. N.; Kashurnikov, V. A.; Rudnev, I. A.

    2017-12-01

    By using the Monte-Carlo method, the dependencies of transport characteristics of a type-II superconductor on the degree of bending strain applied to the sample have been numerically studied. Multiple series of voltage-current characteristics have been acquired for a sample of a high-temperature superconductor for different numbers of strain-induced cracks, as well as various point defects concentrations and different values of external magnetic field. Some peculiarities of the voltage-current characteristics have been detected. Average vortex configurations have been acquired showing that in the points of peculiarities the vortex lattice “freezes” in spaces between cracks. The results for the increasing number of cracks have shown a significant degradation of critical current density.

  2. Mars analog minerals' spectral reflectance characteristics under Martian surface conditions

    Science.gov (United States)

    Poitras, J. T.; Cloutis, E. A.; Salvatore, M. R.; Mertzman, S. A.; Applin, D. M.; Mann, P.

    2018-05-01

    We investigated the spectral reflectance properties of minerals under a simulated Martian environment. Twenty-eight different hydrated or hydroxylated phases of carbonates, sulfates, and silica minerals were selected based on past detection on Mars through spectral remote sensing data. Samples were ground and dry sieved to Mars, only losing adsorbed H2O while maintaining their diagnostic spectral features. Sulfates were less stable, often with shifts in the band position of the SO, Fe, and OH absorption features. Silicas displayed spectral shifts related to SiOH and hydration state of the mineral surface, while diagnostic bands for quartz were stable. Previous detection of carbonate minerals based on 2.3-2.5 μm and 3.4-3.9 μm features appears to be consistent with our results. Sulfate mineral detection is more questionable since there can be shifts in band position related to SO4. The loss of the 0.43 μm Fe3+ band in many of the sulfates indicate that there are fewer potential candidates for Fe3+ sulfates to permanently exist on the Martian surface based on this band. The gypsum sample changed phase to basanite during desiccation as demonstrated by both reflectance and XRD. Silica on Mars has been detected using band depth ratio at 1.91 and 1.96 μm and band minimum position of the 1.4 μm feature, and the properties are also used to determine their age. This technique continues to be useful for positive silica identifications, however, silica age appears to be less consistent with our laboratory data. These results will be useful in spectral libraries for characterizing Martian remote sensed data.

  3. Influence of surface topography on the secondary electron yield of clean copper samples.

    Science.gov (United States)

    Hu, Xiao-Chuan; Cao, Meng; Cui, Wan-Zhao

    2016-11-01

    Secondary electron yield (SEY) due to electron impact depends strongly on surface topography. The SEY of copper samples after Ar-ion bombardment is measured in situ in a multifunctional ultrahigh vacuum system. Increasing the ion energy or duration of ion bombardment can even enlarge the SEY, though it is relatively low under moderate bombardment intensity. The results obtained with scanning electron microscopy and atomic force microscopy images demonstrate that many valley structures of original sample surfaces can be smoothed due to ion bombardment, but more hill structures are generated with stronger bombardment intensity. With increasing the surface roughness in the observed range, the maximum SEY decreases from 1.2 to 1.07 at a surface characterized by valleys, while it again increases to 1.33 at a surface spread with hills. This phenomenon indicates that hill and valley structures are respectively effective in increasing and decreasing the SEY. These obtained results thus provide a comprehensive insight into the surface topography influence on the secondary electron emission characteristics in scanning electron microscopy. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Characteristics of the surface chemistry of linden pyrochar after removal of labile organic matter

    Science.gov (United States)

    Valeeva, A. A.; Smirnova, E. V.; Giniyatullin, K. G.; Vorobev, V. V.; Biktasheva, L. R.; Grachev, A. N.

    2018-01-01

    The changes of chemical properties of the pyrochar surface were studied in the laboratory experiment that simulated pedogenic transformation of pyrochar under the influence of soil biota. The native pyrochar samples were obtained by pyrolysis of linden wood residues at the temperature of 250°C, 450°C and 650°C. Their modified samples were obtained by removing an easily degradable pool of organic substances that can be used by microorganisms during the first months after application to the soil. In low-temperature linden pyrochar (250°C and 450°C) dominated carboxylic and phenolic surface groups, in high-temperature (650°C) - lactonic groups. After removal of readily decomposable organic substances the acidity of the phenolic and lactonic groups in pyrochar of low-temperature pyrolysis sharply decreased. Characteristic feature of all studied samples is the presence in IR spectra of absorption bands of gyroxyl, carbonyl, methylene groups and organosilicon polymers. The feature of IR spectra of linden pyrochar (250°C and 450°C) is the presence of absorption bands of the stretching vibrations of the tertiary alcohols and phenols C-O group.

  5. Impact of the surface characteristics on the quality of INSAR elevation data

    Science.gov (United States)

    Heidelmeyer, G.; Klingauf, U.

    2006-09-01

    Due to upcoming new data driven technologies in the aviation the impact of digital terrain data is growing conspicuously. Especially for ground near operations reliable terrain information is necessarily demanded. Based on modern earth observation technologies a new generation of elevation data is obtainable. However it shall be analysed how far data derived from remote sensing techniques like INSAR or LIDAR can be applied for aviation purposes. Formerly terrain data were represented in relation to the bare earth to obtain a "Digital Terrain Model" (DTM). For aviation purposes a "Digital Surface Model" (DSM) representing the real surface of the earth including all cover like vegetation and buildings is recommended. Due to the characteristics of active remote sensors the derived model always describes an in between of the two elevation representations. To satisfy the special requirements the Institute of Flight Systems and Automatic Control (FSR) at the Technische Universitaet Darmstadt is dealing with the determination of the influencing factors which affect the quality of the terrain models being appropriate to be used as a DSM. In order to enhance the integrity of the data a "safety buffer" is created to allow the applicability for dedicated applications (figure 1).

  6. influence of dietary lipid sources on sensory characteristics of broiler ...

    African Journals Online (AJOL)

    source used during dietary manipulation also has a significant positive effect on production performance and carcass composition. After appearance and tenderness, flavour is the most important characteristic of meat quality perceived by the consumer (Love, 1994). The development of the aroma and flavour of cooked meat ...

  7. Influence of sward characteristics on grazing behaviour and short ...

    African Journals Online (AJOL)

    The feasibility of intensifying grazing studies in the tropics, particularly in Nigeria, to examine the behaviour of ruminants in highly heterogeneous pastures has the potential to provide integrated (sward, animal, management) strategies for sustainable livestock production in Nigeria. Key Words: Sward characteristics; Grazing ...

  8. Filter characteristics influencing circulating tumor cell enrichment from whole blood.

    NARCIS (Netherlands)

    Coumans, F.A.W.; van Dalum, Guus; Beck, Markus; Terstappen, Leonardus Wendelinus Mathias Marie

    2013-01-01

    A variety of filters assays have been described to enrich circulating tumor cells (CTC) based on differences in physical characteristics of blood cells and CTC. In this study we evaluate different filter types to derive the properties of the ideal filter for CTC enrichment. Between 0.1 and 10 mL of

  9. Filter Characteristics Influencing Circulating Tumor Cell Enrichment from Whole Blood

    NARCIS (Netherlands)

    Coumans, Frank A. W.; van Dalum, Guus; Beck, Markus; Terstappen, Leon W. M. M.

    2013-01-01

    A variety of filters assays have been described to enrich circulating tumor cells (CTC) based on differences in physical characteristics of blood cells and CTC. In this study we evaluate different filter types to derive the properties of the ideal filter for CTC enrichment. Between 0.1 and 10 mL of

  10. The role of urban space design characteristics in influencing social ...

    African Journals Online (AJOL)

    This paper is based on a study carried out in Old Town Mombasa, a Swahili city in Kenya, situated along the East African Coast. Its focus is on social life of the town's street system as a correlate of urban space design characteristics. Urban design elements within the streets have been disregarded resulting in spaces that do ...

  11. Influence of Molding Water Content on Shear Strength Characteristic ...

    African Journals Online (AJOL)

    A laboratory investigation was carried out to determine the shear strength characteristics of compacted cement kiln dust treated lateritic soils for use in liners and covers with up to 12.5% cement kiln dust by dry weight of soil. Specimens were prepared at molding water contents of -2, 0, +2 and +4% of the optimum moisture ...

  12. Effect of titanium surface characteristics on the behavior and function of oral fibroblasts.

    Science.gov (United States)

    Att, Wael; Yamada, Masahiro; Ogawa, Takahiro

    2009-01-01

    The purpose of this study was to evaluate the effect of different titanium surface characteristics on the behavior and function of oral fibroblasts as well as the deposition pattern of collagen within the extracellular matrix. Titanium surfaces created by machining, acid etching with sulfuric acid (AE1), or acid etching with hydrofluoric acid (AE2) were analyzed using scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy. Rat oral fibroblasts were cultured on different surfaces. Cell spread and morphology of extracellular matrix were evaluated using SEM. Attachment and proliferation of cells were examined by comparing the numbers of attached to detached cells and cell count, respectively. Gene expression was analyzed via reverse transcriptase polymerase chain reaction. Collagen production and deposition were examined via a Sirius red-based stain assay and confocal laser scanning microscopy. The machined surface showed a flat profile with isotropic grooves, the AE1 surface showed a uniformly microscale roughened surface, and the AE2 surface had a grooved profile with intermediate surface roughness. The AE2 surface contained fluoride atoms (2.45%+/-0.44% as F/Ti atomic ratio). Cell attachment was significantly weaker on the machined surface than on the AE1 and AE2 surfaces, whereas no differences were observed between the AE1 and AE2 surfaces. The cell counts on the machined and AE2 surfaces were higher, with a parallel orientation, whereas the cell count was lower and randomly distributed on the AE1 surface. The expression level of fibroblastic genes was similar among surfaces for all time points tested. Collagen production was highest on the machined surface, followed by AE2 and AE1 surfaces. Collagen deposition displayed a parallel pattern on the machined surface, while it was multidirectional on the AE1 and AE2 surfaces. The surface characteristics of titanium affect attachment, spread, and proliferative activity of oral fibroblasts as well

  13. Surface agents' influence on the flexural strength of bilaminated ceramics

    Directory of Open Access Journals (Sweden)

    Julia Magalhaes Costa Lima

    2013-07-01

    Full Text Available The objective of this study was to evaluate the influence of different surface agents on the flexural strength of a ceramic system. Eighty bar-shaped specimens of zirconia were divided into four groups according to the agent to be used: group Control - to be cleaned with alcohol; group VM9 - application of a fluid layer of porcelain; group Effect Bonder - application of a bonding agent; and group Coloring Liquid - application of coloring liquid. All specimens received the porcelain application by the layering technique and were then subjected to thermocycling. The four-point bending test was performed to calculate the strength values (σ, MPa and the failure modes were classified. ANOVA did not detect significant differences among the groups. The Weibull modulus were 5 (Control, VM9 and Effect Bonder and 6 (Coloring Liquid. The cracking of the porcelain ceramic toward the interface was the predominant failure mode. It was concluded that the surface agents tested had no effect on the flexural strength of the bilaminated ceramic specimens.

  14. The Influence of Slope Breaks on Lava Flow Surface Disruption

    Science.gov (United States)

    Glaze, Lori S.; Baloga, Stephen M.; Fagents, Sarah A.; Wright, Robert

    2014-01-01

    Changes in the underlying slope of a lava flow impart a significant fraction of rotational energy beyond the slope break. The eddies, circulation and vortices caused by this rotational energy can disrupt the flow surface, having a significant impact on heat loss and thus the distance the flow can travel. A basic mechanics model is used to compute the rotational energy caused by a slope change. The gain in rotational energy is deposited into an eddy of radius R whose energy is dissipated as it travels downstream. A model of eddy friction with the ambient lava is used to compute the time-rate of energy dissipation. The key parameter of the dissipation rate is shown to be rho R(sup 2/)mu, where ? is the lava density and mu is the viscosity, which can vary by orders of magnitude for different flows. The potential spatial disruption of the lava flow surface is investigated by introducing steady-state models for the main flow beyond the steepening slope break. One model applies to slow-moving flows with both gravity and pressure as the driving forces. The other model applies to fast-moving, low-viscosity, turbulent flows. These models provide the flow velocity that establishes the downstream transport distance of disrupting eddies before they dissipate. The potential influence of slope breaks is discussed in connection with field studies of lava flows from the 1801 Hualalai and 1823 Keaiwa Kilauea, Hawaii, and 2004 Etna eruptions.

  15. Effect of elemental sulfur in precursors on the pore structure and surface chemical characteristics of high-surface area activated carbon

    Directory of Open Access Journals (Sweden)

    Jing Zhao

    2017-09-01

    Full Text Available Analog sulfur-containing precursors (ASCPs have been prepared by adding a certain amount of elemental sulfur (ES into petroleum coke (PC for synthesis of high-surface area activated carbon (HAC. ASCPs make it feasible to control the speciation and content of sulfur in ASCPs, so as to accurately investigate the influence of ES on the pore structure and surface chemical characteristics of the resultant HAC. The results indicate that ES in ASCPs can react with activator KOH and consume a part of KOH amount, thus leading to the deficiency of actual KOH amount for PC activation, eventually making a decrease in the specific surface area and pore volume of HAC. Interestingly, some of ES in ASCPs is transformed into organic sulfur thioether (C–S–C and sulfate (C–SO4–C or sulfonate (C–SO3–C on HAC surface during the activation process. Therefore, the surface chemical characteristics of HAC are modified correspondingly.

  16. Influence of storm characteristics on soil erosion and storm runoff

    Science.gov (United States)

    Johnny M. III Grace

    2008-01-01

    Unpaved forest roads can be major sources of sediment from forested watersheds. Storm runoff from forest roads are a concern due to their potential delivery of sediments and nutrients to stream systems resulting in degraded water quality. The volume and sediment concentrations of stormwater runoff emanating from forest roads can be greatly influenced by storm...

  17. Influence of hydrophobic characteristic of organo-modified precursor ...

    Indian Academy of Sciences (India)

    The aim of this contribution is to show the influence of different organic chains attached on silica nanoparticles which accomplish hydrophobic properties related to the sol- vents with different polarities (high hydrophilic-water, gly- cerol; high hydrophobic-α-bromonaphthalene; intermediate, dimethylsulfoxide (DMSO).

  18. influence of molding water content on shear strength characteristic

    African Journals Online (AJOL)

    eobe

    INFLUENCE OF MOLDING WATER CONTENT ON SHEAR STRENGTH OF COMPACTED CEMENT KILN DUST, K. J. Osinub. K. J. Osinub. K. J. Osinubi, et al. Nigerian Journal of Technology,. Vol. 34, No. 2, April 2015 267 pavements or as waste containment materials. Therefore, recent studies have been geared towards.

  19. Circulation and water characteristics on isanosteric surfaces in the Northern Arabian Sea during February-April

    Digital Repository Service at National Institute of Oceanography (India)

    Das, V.K.; Gouveia, A.D.; Varma, K.K.

    Distribution of water characteristics and circulation were studied on 260, 160, 140, 120 and 80 cl/t surfaces using isanosteric analysis and geostrophic computation The circulation pattern consisted of several eddies and meanders The most prominent...

  20. Reciprocal Influences of Personality and Job Characteristics Across Middle Adulthood

    OpenAIRE

    Sutin, Angelina R.; Costa, Paul T.

    2010-01-01

    The present research uses an economically diverse, middle-aged sample to examine the concurrent and longitudinal interplay between personality and occupational experiences. Using the Five-Factor Model of personality and the Demand-Control Model of the occupational environment as guiding frameworks, participants (N = 722) reported on their personality, job characteristics, and occupational history; a subset (n = 297) made the same ratings approximately 10 years later. Measured concurrently, em...

  1. The Influence of Maternal Psychosocial Characteristics on Infant Feeding Styles

    OpenAIRE

    Barrett, Katherine J.; Thompson, Amanda L.; Bentley, Margaret E.

    2016-01-01

    Maternal feeding styles in infancy and early childhood are associated with children’s later risk for overweight and obesity. Maternal psychosocial factors that influence feeding styles during the complementary feeding period, the time during which infants transition from a milk-based diet to one that includes solid foods and other non-milk products, have received less attention. The present study explores how maternal psychosocial factors—specifically self-esteem, parenting ...

  2. Heterogeneity of soil surface ammonium concentration and other characteristics, related to plant specific variability in a Mediterranean-type ecosystem

    International Nuclear Information System (INIS)

    Cruz, Cristina; Bio, Ana M.F.; Jullioti, Aldo; Tavares, Alice; Dias, Teresa; Martins-Loucao, Maria Amelia

    2008-01-01

    Heterogeneity and dynamics of eight soil surface characteristics essential for plants-ammonium and nitrate concentrations, water content, temperature, pH, organic matter, nitrification and ammonification rates-were studied in a Mediterranean-type ecosystem on four occasions over a year. Soil properties varied seasonally and were influenced by plant species. Nitrate and ammonium were present in the soil at similar concentrations throughout the year. The positive correlation between them at the time of greatest plant development indicates that ammonium is a readily available nitrogen source in Mediterranean-type ecosystems. The results presented here suggest that plant cover significantly affects soil surface characteristics. - In Mediterranean-type ecosystems ammonium is present in the soil throughout the year and its concentration is dependent on plant cover

  3. Multivariate analysis of attachment of biofouling organisms in response to material surface characteristics.

    Science.gov (United States)

    Gatley-Montross, Caitlyn M; Finlay, John A; Aldred, Nick; Cassady, Harrison; Destino, Joel F; Orihuela, Beatriz; Hickner, Michael A; Clare, Anthony S; Rittschof, Daniel; Holm, Eric R; Detty, Michael R

    2017-12-29

    Multivariate analyses were used to investigate the influence of selected surface properties (Owens-Wendt surface energy and its dispersive and polar components, static water contact angle, conceptual sign of the surface charge, zeta potentials) on the attachment patterns of five biofouling organisms (Amphibalanus amphitrite, Amphibalanus improvisus, Bugula neritina, Ulva linza, and Navicula incerta) to better understand what surface properties drive attachment across multiple fouling organisms. A library of ten xerogel coatings and a glass standard provided a range of values for the selected surface properties to compare to biofouling attachment patterns. Results from the surface characterization and biological assays were analyzed separately and in combination using multivariate statistical methods. Principal coordinate analysis of the surface property characterization and the biological assays resulted in different groupings of the xerogel coatings. In particular, the biofouling organisms were able to distinguish four coatings that were not distinguishable by the surface properties of this study. The authors used canonical analysis of principal coordinates (CAP) to identify surface properties governing attachment across all five biofouling species. The CAP pointed to surface energy and surface charge as important drivers of patterns in biological attachment, but also suggested that differentiation of the surfaces was influenced to a comparable or greater extent by the dispersive component of surface energy.

  4. The influence of surface functionalisation on the electrical properties and thermal stability of nanodiamonds

    Energy Technology Data Exchange (ETDEWEB)

    Welch, Joseph O; Li, Pei; Chaudhary, Aysha; Edgington, Robert; Jackman, Richard B., E-mail: r.jackman@ucl.ac.uk [London Centre for Nanotechnology and the Department of Electronic and Electrical Engineering, University College London, 17-19 Gordon Street, London WC1H 0AH (United Kingdom)

    2014-10-07

    Detonation nanodiamond (ND) has recently emerged as a useful new class of diamond material. However, to date there has been little investigation of the electrical properties of this material. Due to the nanoscale dimensions, the surface functionalisation of the individual ND is of particular importance to the characteristics of ND films. Here, hydrogen and oxygen termination of ND, verified using Fourier transform infrared spectroscopy, are shown to strongly influence the electronic properties of NDs. Hydrogen terminated ND exhibiting a far greater resilience to thermal decomposition when compared to the oxygen terminated NDs. Moreover, H-NDs also displayed so-called “surface conductivity,” a property displayed by hydrogen-terminated bulk diamond films, whilst O-NDs display properties high resistivity. These results indicate that under the correct conditions ND layers can display similar electrical properties to “bulk” diamond thin films.

  5. Influence of non-adherent yeast cells on electrical characteristics of diamond-based field-effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Procházka, Václav, E-mail: prochazkav@fzu.cz [Faculty of Electrical Engineering, Czech Technical University in Prague, Technická 2, 16627 Prague (Czech Republic); Institute of Physics, The Czech Academy of Sciences, Cukrovarnická 10/112, 162 00 Prague (Czech Republic); Cifra, Michal [Institute of Photonics and Electronics, The Czech Academy of Sciences, Chaberská 57, 182 51 Prague (Czech Republic); Kulha, Pavel [Faculty of Electrical Engineering, Czech Technical University in Prague, Technická 2, 16627 Prague (Czech Republic); Institute of Physics, The Czech Academy of Sciences, Cukrovarnická 10/112, 162 00 Prague (Czech Republic); Ižák, Tibor [Institute of Physics, The Czech Academy of Sciences, Cukrovarnická 10/112, 162 00 Prague (Czech Republic); Rezek, Bohuslav [Faculty of Electrical Engineering, Czech Technical University in Prague, Technická 2, 16627 Prague (Czech Republic); Institute of Physics, The Czech Academy of Sciences, Cukrovarnická 10/112, 162 00 Prague (Czech Republic); Kromka, Alexander [Institute of Physics, The Czech Academy of Sciences, Cukrovarnická 10/112, 162 00 Prague (Czech Republic); Faculty of Civil Engineering, Czech Technical University in Prague, Thákurova 7, 16629 Prague (Czech Republic)

    2017-02-15

    Highlights: • Interaction of non-adherent yeast cells with H-terminated diamond described. • Effect of cell culture solutions on H-diamond SGFET (positive potential shifts). • H-diamond sensitive to metabolic activity of yeast cells (negative potential shift). - Abstract: Diamond thin films provide unique features as substrates for cell cultures and as bio-electronic sensors. Here we employ solution-gated field effect transistors (SGFET) based on nanocrystalline diamond thin films with H-terminated surface which exhibits the sub-surface p-type conductive channel. We study an influence of yeast cells (Saccharomyces cerevisiae) on electrical characteristics of the diamond SGFETs. Two different cell culture solutions (sucrose and yeast peptone dextrose–YPD) are used, with and without the cells. We have found that transfer characteristics of the SGFETs exhibit a negative shift of the gate voltage by −26 mV and −42 mV for sucrose and YPD with cells in comparison to blank solutions without the cells. This effect is attributed to a local pH change in close vicinity of the H-terminated diamond surface due to metabolic processes of the yeast cells. The pH sensitivity of the diamond-based SGFETs, the role of cell and protein adhesion on the gate surface and the role of negative surface charge of yeast cells on the SGFETs electrical characteristics are discussed as well.

  6. Influence on rod-pinch diode performance of suppressing electron emission from different cathode surfaces

    International Nuclear Information System (INIS)

    Gao Yi; Lv Min; Qiu Aici; Yang Hailiang; Liang Tianxue; Zhang Zhong

    2010-01-01

    The electron pinching process of a rod-pinch diode is simulated with UNIPIC. It indicates that the pinching characteristics of the electrons emitted from different cathode surfaces differ significantly. The electrons emitted from the downstream surface pinch worst, with large amount of electrons hitting upstream of the rod, which increases the axial bremsstrahlung X-ray spot size. The simulation results show that suppressing electron emission from the downstream surface will reduce the axial X-ray spot size and improve the pinching quality. Composite cathodes are designed to investigate the influence of suppressing electron emission from the upstream or downstream surface. Experiments are performed on the new-built IVA (Inductive Voltage Adder) device at the peak voltage of ∼1.5 MV, and the peak current of ∼44 kA. It is shown that the composite cathode is effective in suppressing electron emission from the specific surface, the axial X-ray spot size in the case of downstream suppression is about 14.5% less than the case of upstream suppression and in both cases, the axis-on X-ray dose at 1 meter from the rod tip is ∼1.9rads, validating the simulation results. (authors)

  7. Influence of changes in surface layer properties on tire/pavement noise

    NARCIS (Netherlands)

    Li, M.; Van Keulen, W.; Ceylan, H.; Van de Ven, M.F.C.; Molenaar, A.A.A.

    2013-01-01

    This paper investigates changes in tire/pavement noise caused by variations in the road surface characteristics. This research is based on the analysis of noise and surface characteristics collected from sections with 25 mm thickness thin layer surfacings in the Netherlands. Investigations are first

  8. Characteristics of leadership that influence clinical learning: a narrative review.

    Science.gov (United States)

    Walker, Rachel; Cooke, Marie; Henderson, Amanda; Creedy, Debra K

    2011-11-01

    Leadership has been consistently implied in fostering clinical learning. However there is a lack of clarity about the form leadership should take. Limited quantitative research indicated a narrative approach to review literature from a broad perspective. A framework to guide the synthesis was developed to ensure a rigorous review process. Preliminary reading and review of papers using search terms nursing and leadership and clinical learning and learning culture narrowed the inclusion criteria to 245 papers published between 2000 and 2010. Given the diversity of the papers' focus, aim and context, a refined screening process justified the inclusion of twenty-six papers in the review. A critical appraisal of these peer-reviewed quantitative, qualitative and commentary papers identified factors/elements integral to effective leadership. Across the literature leadership was discussed in relation to two broad themes: influence of leadership on organisational learning and development and; influence of leadership on undergraduate clinical education. The factors central to leadership emerged as transformative principles, the role of the nurse unit/ward manager, collaboration and relationship building and role-modelling. The review has raised some suggestions for future research aimed at examining the impact of a leadership capacity building intervention that supports clinical learning. Copyright © 2010 Elsevier Ltd. All rights reserved.

  9. Incubation Temperature during Fetal Development Influences Morphophysiological Characteristics and Preferred Ambient Temperature of Chicken Hatchlings.

    Directory of Open Access Journals (Sweden)

    Viviane de Souza Morita

    Full Text Available Skin and feather characteristics, which play a critical role in body temperature maintenance, can be affected by incubation circumstances, such as incubation temperature. However, no study to date has assessed the influence of incubation temperature during the fetal stage on morphometric characteristics and vascular development of the skin, feather characteristics, and their relationship to hormone levels and preferred temperature in later life in chickens. Broiler breeder eggs were exposed to low (36°C, control (37.5°C, or high (39°C temperatures (treatments LT, CK, and HT, respectively from day 13 of incubation onward, because it is known that the endocrine axes are already established at this time. During this period, eggshell temperature of HT eggs (38.8±0.33°C was higher than of LT (37.4±0.08°C and CK eggs (37.8 ±0.15°C. The difference between eggshell and incubator air temperature diminished with the increasing incubation temperature, and was approximately zero for HT. HT hatchlings had higher surface temperature on the head, neck, and back, and thinner and more vascularized skin than did CK and LT hatchlings. No differences were found among treatments for body weight, total feather weight, number and length of barbs, barbule length, and plasma T4 concentration. LT hatchlings showed lower plasma T3 and GH, as well as lower T3/T4 ratio and decreased vascularity in the neck, back, and thigh skin compared to CK hatchlings. On the other hand, HT hatchlings had decreased skin thickness and increased vascularity, and preferred a higher ambient temperature compared to CK and HT hatchlings. In addition, for all treatments, surface temperature on the head was higher than of the other body regions. We conclude that changes in skin thickness and vascularity, as well as changes in thyroid and growth hormone levels, are the result of embryonic strategies to cope with higher or lower than normal incubation temperatures. Additionally exposure to

  10. Influence of surface treatments on the surface properties of different zirconia cores and adhesion of zirconia-veneering ceramic systems.

    Science.gov (United States)

    Elsaka, Shaymaa E

    2013-10-01

    The aim of this study was to assess the influence of surface treatments on the surface characteristics of different zirconia cores and the adhesion of the zirconia-veneering ceramic systems by means of strain energy release rate (G-value, J/m(2)). Three types of zirconia cores (NANOZR (NZ), Vita In-Ceram YZ (VZ), and IPS e.max ZirCAD (IZ)) were used. The specimens were divided into four groups in each test according to the surface treatment used; Gr 1 (control; no treatment), Gr 2 (sandblasted), Gr 3 (CH2Cl2 for 60min), and Gr 4 (experimental hot etching solution for 60min). AFM, SEM, EDS, and XRD were carried out. Two types of veneering ceramics (Vita VM9 (V9) and IPS e.max Ceram (IC)) were used for testing the adhesion. The G-value (J/m(2)) was measured with a four-point bending configuration. Following fracture testing specimens were examined with SEM. Data were analyzed using ANOVA and Tukey's test. NZ treated with the experimental hot etching solution showed the highest Ra values (206.06±9.98nm) compared with the other groups (Pveneering ceramic systems. The experimental hot etching solution could be considered as alternative treatment modality to sandblasting for zirconia cores to avoid phase transition at the surface from tetragonal to monoclinic that may be detrimental for the longevity of the zirconia-veneering ceramic restoration. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  11. Influence of production technology and design on characteristics neutron-sensitive P-I-N diodes

    International Nuclear Information System (INIS)

    Perevertaylo, V.L.; Kovrygin, V.I.

    2012-01-01

    This paper presents the results of tests on neutron-sensitive p-i-n diode with local p-n junction, which allows to measure not only the integral dose by nonionizing energy loss (NIEL), but also the real-time dose and dose rate because of ionizing energy losses (IEL). The influence of design and process parameters and the lifetime of minority carriers on the radiation characteristics of the device considered. Sensitivity at low doses (from one to ten rad) is limited due to a decrease in the lifetime because of influence of lateral sides of cut. The sensitivity and accuracy of dose can be increased by moving of p-n junction away from the cut surface. The dependence of the voltage drop across the diode on the neutron dose irradiation up to 5 krad received, and the sensitivity was 2 - 3 mV/rad. We have demonstrated that replacement of the bulk p-i-n diode with total p-n junction by new diodes with local p-n junction allow for increase sensitivity, accuracy of dose and application in NIEL and IEL measurements simultaneously. Explanation for the extinction of a direct current through the diode with increasing doses of neutron irradiation proposed

  12. The influence of small urban parks characteristics on bird diversity

    DEFF Research Database (Denmark)

    Jasmani, Zanariah; Ravn, Hans Peter; van den Bosch, Cecil C.Konijnendijk

    2017-01-01

    of tree canopy cover, open grass/ground, native-exotic plants) are the important predictors of bird species richness and abundance. The percentage of canopy covers (negative relation) and park area (positive relation) are the best predictors of bird species richness in small urban parks. Meanwhile......, the best predictors for bird abundance are the percentage of canopy covers (negative relation) and native vegetation species (positive relation). Human activities and park surroundings have a marginal effect on the presence of bird species in small parks. Based on the findings, we provide two general...... using the combined field survey method of structured observation and field measurements. The measured variables were divided into three broad categories of physical characteristics, species richness and human factors. Bird species richness and abundance were used as the indicators for assessing...

  13. Influence of Main Characteristic Features of Spot Welding on Welded Connection/Joint Strength

    Science.gov (United States)

    Al Quran, Firas M. F.; Matarneh, M. I.; Belik, A. G.

    2014-03-01

    To provide the required quality of welded connection in spot welding, an investigation of the influence of characteristic features of welding conditions on the welded connection strength and choice of the best process parameters are carried out.

  14. Study of the Accelerating Channel Wall Property Influence on the Hall Thruster Discharge Characteristics

    National Research Council Canada - National Science Library

    Vesselovzorov, Alexandre

    2004-01-01

    According to the work program and schedule there was developed the methodology of experiments on the discharge chamber material influence on the Hall thruster characteristics there was prepared Hall...

  15. Influence of pectin supplementation on feed fermentation characteristics in rats and pigs

    NARCIS (Netherlands)

    Tian, L.

    2016-01-01

    The physiological effects of dietary fiber (DFs) depend on several factors including structural features of the DFs, composition and activity of colonic microbiota, and products formed during fermentation. In this thesis, the influence of pectin supplementation to feed fermentation characteristics

  16. Influence of distribution characteristics and associated seabed features on exploitation of cobalt-rich manganese deposits

    Digital Repository Service at National Institute of Oceanography (India)

    Yamazaki, T.; Sharma, R.; Tsurusaki, K.

    Method of exploitation, selection of mine site and desing of mining system of cobalt-rich manganese deposits on seamounts would be greatly influenced by the distribution characteristics as well as the associated seabed features, wuch as the seabed...

  17. Building defects in Danish construction: project characteristics influencing the occurrence of defects at handover

    DEFF Research Database (Denmark)

    Schultz, Casper Siebken; Jørgensen, Kirsten; Bonke, Sten

    2015-01-01

    characteristics are the planning of budgetary conditions, time schedules and early, continuous quality control. Furthermore, this study also indicates collaboration between stakeholders plus skills and safety initiatives as having a positive influence on the performance measured as defects at handover....

  18. Influence of mechanical strain on magnetic characteristics of spin valves

    Science.gov (United States)

    Áč, V.; Anwarzai, B.; Luby, S.; Majkova, E.

    2008-03-01

    Giant magnetoresistance (GMR) of Co and Fe-Co based e-beam evaporated spin valves with Cu and Au spacers was studied. The effect of strain on samples, which is detrimental in standard GMR sensors, was measured in a bending configuration. The different dependences of coercivity Hc and magnetic field Hip in the point of inflection of MR loops vs. strain were found. For sample with Co/Au/Co core, Hc, Hip increase with increasing compressive stress, whereas for sample with FeCo/Cu/Co core they increase with tensile stress. The highest relative change of MR ratio vs. bending in the strain interval ± 300 × 10-6 is 1-2 % of the basic magnetoresistance and, practically, it does not influence the SV output.

  19. Influence of disorder on transfer characteristics of organic electrochemical transistors

    KAUST Repository

    Friedlein, Jacob T.

    2017-07-13

    Organic electrochemical transistors (OECTs) are receiving a great deal of attention as transducers of biological signals due to their high transconductance. A ubiquitous property of these devices is the non-monotonic dependence of transconductance on gate voltage. However, this behavior is not described by existing models. Using OECTs made of materials with different chemical and electrical properties, we show that this behavior arises from the influence of disorder on the electronic transport properties of the organic semiconductor and occurs even in the absence of contact resistance. These results imply that the non-monotonic transconductance is an intrinsic property of OECTs and cannot be eliminated by device design or contact engineering. Finally, we present a model based on the physics of electronic conduction in disordered materials. This model fits experimental transconductance curves and describes strategies for rational material design to improve OECT performance in sensing applications.

  20. Influence of degradation process on rheological characteristics of polymer materials

    Directory of Open Access Journals (Sweden)

    Michaela Vojsovičová

    2012-09-01

    Full Text Available Rheological properties of thermoplastic polymer materials before and after exposure in chemical solution were evaluated using Frequency sweep test, which monitors changes in viscoelastic properties of polymers with respect to their molecular structure and their behavior in thermoplastic processes. As experimental material thermoplastic polyethylene and polypropylene samples were used and subjected to influence of n‑hexane solution for period of 3 and 6 months. Measurements were performed using oscillating rheometer Physica Rheometer MCR 301 and carried out at the temperature of 160 °C and 180 °C. Degradation process resulted in changes of complex dynamic viscosity, storage and loss modulus, changes in molar mass and its distribution which sufficiently prove the rheological changes.

  1. Influence of mechanical strain on magnetic characteristics of spin valves

    International Nuclear Information System (INIS)

    Ac, V; Anwarzai, B; Luby, S; Majkova, E

    2008-01-01

    Giant magnetoresistance (GMR) of Co and Fe-Co based e-beam evaporated spin valves with Cu and Au spacers was studied. The effect of strain on samples, which is detrimental in standard GMR sensors, was measured in a bending configuration. The different dependences of coercivity H c and magnetic field H ip in the point of inflection of MR loops vs. strain were found. For sample with Co/Au/Co core, H c , H ip increase with increasing compressive stress, whereas for sample with FeCo/Cu/Co core they increase with tensile stress. The highest relative change of MR ratio vs. bending in the strain interval ± 300 x 10 -6 is 1-2 % of the basic magnetoresistance and, practically, it does not influence the SV output

  2. Influence of disorder on transfer characteristics of organic electrochemical transistors

    Science.gov (United States)

    Friedlein, Jacob T.; Rivnay, Jonathan; Dunlap, David H.; McCulloch, Iain; Shaheen, Sean E.; McLeod, Robert R.; Malliaras, George G.

    2017-07-01

    Organic electrochemical transistors (OECTs) are receiving a great deal of attention as transducers of biological signals due to their high transconductance. A ubiquitous property of these devices is the non-monotonic dependence of transconductance on gate voltage. However, this behavior is not described by existing models. Using OECTs made of materials with different chemical and electrical properties, we show that this behavior arises from the influence of disorder on the electronic transport properties of the organic semiconductor and occurs even in the absence of contact resistance. These results imply that the non-monotonic transconductance is an intrinsic property of OECTs and cannot be eliminated by device design or contact engineering. Finally, we present a model based on the physics of electronic conduction in disordered materials. This model fits experimental transconductance curves and describes strategies for rational material design to improve OECT performance in sensing applications.

  3. Fog collecting biomimetic surfaces: Influence of microstructure and wettability

    International Nuclear Information System (INIS)

    Azad, M A K; Ellerbrok, D; Barthlott, W; Koch, K

    2015-01-01

    We analyzed the fog collection efficiency of three different sets of samples: replica (with and without microstructures), copper wire (smooth and microgrooved) and polyolefin mesh (hydrophilic, superhydrophilic and hydrophobic). The collection efficiency of the samples was compared in each set separately to investigate the influence of microstructures and/or the wettability of the surfaces on fog collection. Based on the controlled experimental conditions chosen here large differences in the efficiency were found. We found that microstructured plant replica samples collected 2–3 times higher amounts of water than that of unstructured (smooth) samples. Copper wire samples showed similar results. Moreover, microgrooved wires had a faster dripping of water droplets than that of smooth wires. The superhydrophilic mesh tested here was proved more efficient than any other mesh samples with different wettability. The amount of collected fog by superhydrophilic mesh was about 5 times higher than that of hydrophilic (untreated) mesh and was about 2 times higher than that of hydrophobic mesh. (paper)

  4. Influence of steam parameters on static and dynamic characteristics of labyrinth seal

    Directory of Open Access Journals (Sweden)

    HE Wenqiang

    2017-10-01

    Full Text Available [Objectives] In order to study the influence of working medium parameters on the static and dynamic characteristics of seals in turbomachinery,[Methods] a three-dimensional model of a labyrinth seal was created, and air and steam were applied in the numerical simulation. The Computational Fluid Dynamics (CFD method and a rotating frame were applied to analyze the influence of different steam parameters on the leakage characteristics and dynamic characteristic coefficients.[Results] The results show that great differences in leakage flow rate are apparent under different air and steam conditions, and the fluid-induced force shows linear and nonlinear variation with the increasing whirl speed. When the steam temperature increases, the system stability decreases as the dynamic characteristic coefficients change.[Conclusions] In consequence, working medium parameters are of great significance for turbine stability, and the influence of working medium parameters on the static and dynamic characteristics of seals should be given great attention in practical application.

  5. Influence of pH on the physicochemical and sensorial characteristics of strawberry frozen yogurt

    OpenAIRE

    Pereira, Gustavo das Graças; Rafael, Leonardo Mesquita; Gajo, Adriano Alvarenga; Ramos, Thaís de Melo; Pinto, Sandra Maria; Resende, Jaime Vilela de; Abreu, Luiz Ronaldo de

    2012-01-01

    Frozen yogurt is a frozen fermented dessert which presents structural characteristics similar to ice cream and nutritional and sensorial properties which resemble to yogurt. The acidification of ice cream mix by means of lactic bacteria can influence the properties of frozen yogurt. For that reason, the present work aimed to evaluate the influence of pH on the physicochemical and sensorial characteristics of strawberry frozen yogurt. The formulation consisted of 6 % of milk fat, 10 % of milk ...

  6. Influence of Surface Roughness of Stainless steel on Microbial Adhesion

    DEFF Research Database (Denmark)

    Bagge, D.; Hilbert, Lisbeth Rischel; Gram, L.

    2002-01-01

    status of the surface; it is assumed that microorganisms hide in scratches and cracks. It is also believed that the smoother a surface the better. And a surface with a few microorganisms after cleaning and disinfection is more hygienic and has a lower risk for cross contamination than a surface with many...

  7. INFLUENCE OF THE ENVIRONMENT CHARACTERISTICS ON INDUSTRY SYSTEM EVOLUTION

    Directory of Open Access Journals (Sweden)

    Markov L. S.

    2014-09-01

    Full Text Available On the basis of the constructed evolutionary model in relation to branch of production of steam coals its structural transformation at taking note of various environmental characteristics is considered: endogenous competition, antimonopoly and anti-recessionary regulation. As an indicator of evolution of system it is offered to consider its structural change (Herfindahl-Hirschman index. The executed modeling showed that the speed of evolution of system, more intensive processes of concentration is in direct dependence on a price factor and in inverse relationship from rigidity of criteria of a dominant position. Frequency of transformation of system grows at increase in sensitivity of market price to a ratio of supply and demand and at cancellation of restrictions on the maximum volume, and decreases at liberalization of anti-recessionary regulation. It is shown that actions of antimonopoly and antirecessionary regulation can make sense in the short-term period, but in long-term prospect they lead to braking of development of system.

  8. Coronary angiographic characteristics that influence fractional flow reserve.

    Science.gov (United States)

    Natsumeda, Makoto; Nakazawa, Gaku; Murakami, Tsutomu; Torii, Sho; Ijichi, Takeshi; Ohno, Yohei; Masuda, Naoki; Shinozaki, Norihiko; Ogata, Nobuhiko; Yoshimachi, Fuminobu; Ikari, Yuji

    2015-01-01

    Percutaneous coronary intervention (PCI) guided with fractional flow reserve (FFR) has been shown to improve clinical outcome. Although coronary angiography is the standard method for PCI guidance, the visual severity of stenosis is not always correlated with functional severity, suggesting that there are additional angiographic factors that affect functional ischemia. To evaluate angiographic predictors of positive FFR in stenotic lesions, angiographic characteristics of 260 consecutive patients (362 lesions) who underwent FFR testing from April 2009 to September 2012 were analyzed. A scoring system (STABLED score) using these predictors was developed and compared with quantitative coronary angiography (QCA). %Diameter stenosis >50% (OR, 8.43; P20 mm (OR, 5.40; P=0.0002), and distance from ostium <20 mm (OR, 1.94; P=0.028) were determined as independent predictors of positive FFR. Area under the ROC curve for probability of positive FFR using the STABLED score (Stenosis 2 points, TAndem lesion 1 point, Bifurcation 1 point, LEsion length 1 point, Distance from ostium 1 point) was 0.85, higher than that for QCA stenosis alone (0.76). STABLED score ≥3 had 72.3% sensitivity and 83.6% specificity for predicting positive FFR, and PPV was 76.7%. Specific angiographic features are applicable for predicting functional ischemia. STABLED score correlates well with FFR.

  9. Influence of potassium hydroxide activation on characteristics and environmental risk of heavy metals in chars derived from municipal sewage sludge.

    Science.gov (United States)

    Li, Zhengjia; Deng, Hui; Yang, Le; Zhang, Genlin; Li, Yuqi; Ren, Yansen

    2018-05-01

    To investigate the influence of KOH activation on characteristics and environmental risk of heavy metals in chars, sludge was pyrolyzed with varying amount of KOH. The analyzation of characteristics and potential ecological risk evaluation of heavy metals were conducted by surface area analyzer, FTIR, XRD and BCR sequential extraction. The activated chars have higher surface area and lower content of silica compared to those without being activated. The activation of KOH promoted residual fraction of Cd, meanwhile, Zinc, Cr, Ni and Mn were converted to relatively unstable fractions (F2 and F3). The results of risk assessment indicated that the potential ecological risk level of Cd was reduced in activated chars, while risk level of Zn, Cr, Ni and Mn were increased after pyrolysis with KOH activation. The potential ecological risk of heavy metals in activated chars was further declined, and the risk level transformed from moderate to low. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Heat transfer characteristics in closed-loop spray cooling of micro-structured surfaces

    International Nuclear Information System (INIS)

    Zhang Wei; Wang Zhaoliang; Xu Minghai

    2012-01-01

    With water as the working fluid, experiments on the heat transfer characteristics of spray cooling of micro-structured surfaces were performed in a closed loop system. Experimental data were analyzed in the view of the ratio between convective heat transfer and phase change heat transfer. The results indicate that heat transfer is obviously enhanced for micro-channel surfaces relative to the flat surface because of higher phase change heat transfer. For the geometries tested at lower surface temperature, the straight finned surface has the largest heat flux; while at higher surface temperature, the cubic pin finned surface has the largest heat flux. Heat fluxes of all the surfaces grow with increasing flow rates, except for the straight finned surface under lower surface temperature. The ratio of phase change to total heat transfer is bigger than 20% for the flat surface, and higher than 50% for micro-structured surface. Critical heat fluxes of 159.1 W/cm 2 , 120.2 W/cm 2 , and 109.8 W/cm 2 are attained respectively for cubic pin finned, straight finned and flat surfaces when the flow rate is 15.9 mL/min, and the corresponding evaporation efficiency are 96.0%, 72.5%, 67.1%. (authors)

  11. Influence of feedback characteristics on perceived learning value of feedback in clerkships : does culture matter?

    NARCIS (Netherlands)

    Suhoyo, Yoyo; Van Hell, Elisabeth A.; Kerdijk, Wouter; Emilia, Ova; Schonrock-Adema, Johanna; Kuks, Jan B. M.; Cohen-Schotanus, Janke

    2017-01-01

    Background: Various feedback characteristics have been suggested to positively influence student learning. It is not clear how these feedback characteristics contribute to students' perceived learning value of feedback in cultures classified low on the cultural dimension of individualism and high on

  12. Herd characteristics influence farmers’ preferences for trait improvements in Danish Red and Danish Jersey cows

    DEFF Research Database (Denmark)

    Slagboom, Margot; Kargo, Morten; Edwards, David

    2016-01-01

    of a cluster analysis, three distinct clusters of farmers were identified per breed. Comparisons of herd characteristics between clusters suggest that farmers choose to improve traits that are problematic in their herds. This study shows that heterogeneity exists in farmers’ preferences for trait improvements...... and that herd characteristics influence these preferences in DR and DJ....

  13. Manual Signing in Adults with Intellectual Disability: Influence of Sign Characteristics on Functional Sign Vocabulary

    Science.gov (United States)

    Meuris, Kristien; Maes, Bea; De Meyer, Anne-Marie; Zink, Inge

    2014-01-01

    Purpose: The purpose of this study was to investigate the influence of sign characteristics in a key word signing (KWS) system on the functional use of those signs by adults with intellectual disability (ID). Method: All 507 signs from a Flemish KWS system were characterized in terms of phonological, iconic, and referential characteristics.…

  14. The influence of perceived characteristics of management development programs on employee outcomes.

    NARCIS (Netherlands)

    Ardts, J.C.A.; van der Velde, M.E.G.; Maurer, T.

    2010-01-01

    Employees’ perceptions of Management Development (MD) programs is the topic of this study. The purpose is to examine the influence of three important perceived characteristics of MD programs on relevant MD outcomes. The MD characteristics are: availability of role models, perceived control, and

  15. A study of soil surface characteristics in a small watershed in the hilly, gullied area on the Chinese Loess Plateau

    NARCIS (Netherlands)

    Liu Guobin,; Xu Mingxiang,; Ritsema, C.J.

    2003-01-01

    Soil surface characteristics are closely related to soil surface depressional storage, infiltration, runoff generation and soil erosion, especially in highly erodible loess soil. Soil surface random roughness, soil cohesion and aggregate stability are necessary parameters in the Limburg Soil Erosion

  16. Surface flux density distribution characteristics of bulk high-T c superconductor in external magnetic field

    International Nuclear Information System (INIS)

    Nishikawa, H.; Torii, S.; Yuasa, K.

    2005-01-01

    This paper describes the measured results of the two-dimensional flux density distribution of a YBCO bulk under applied AC magnetic fields with various frequency. Melt-processed oxide superconductors have been developed in order to obtain strong pinning forces. Various electric mechanical systems or magnetic levitation systems use those superconductors. The major problem is that cracks occur because the bulk superconductors are brittle. The bulk may break in magnetizing process after cracks make superconducting state instable. The trapped flux density and the permanent current characteristics of bulk superconductors have been analyzed, so as to examine the magnetizing processes or superconducting states of the bulk. In those studies, the two-dimensional surface flux density distributions of the bulk in static fields are discussed. On the other hand, the distributions in dynamic fields are little discussed. We attempted to examine the states of the bulk in the dynamic fields, and made a unique experimental device which has movable sensors synchronized with AC applied fields. As a result, the two-dimensional distributions in the dynamic fields are acquired by recombining the one-dimensional distributions. The dynamic states of the flux of the bulk and the influences of directions of cracks are observed from the distributions. In addition, a new method for measuring two-dimensional flux density distribution under dynamic magnetic fields is suggested

  17. Lubrication and thermal characteristics of mechanical seal with porous surface based on cavitation

    Science.gov (United States)

    Huilong, Chen; Muzi, Zuo; Tong, Liu; Yu, Wang; Cheng, Xu; Qiangbo, Wu

    2014-04-01

    The theory model of mechanical seals with laser-textured porous surface (LST-MS) was established. The liquid film of LST-MS was simulated by the Fluent software, using full cavitation model and non-cavitation model separately. Dynamic mesh technique and relationship between viscosity and temperature were applied to simulate the internal flow field and heat characteristics of LST-MS, based on the more accurate cavitation model. Influence of porous depth ratio porous diameter ɛ and porous density SP on lubrication performance and the variation of lubrication and thermal properties with shaft speed and sealing pressure were analyzed. The results indicate that the strongest hydrodynamic pressure effect and the biggest thickness of liquid film are obtained when ɛ and SP are respectively about 0.025 and 0.5 which were thought to be the optimum value. The frictional heat leads to the increase of liquid film temperature and the decrease of medium viscosity with the shaft speed increasing. The hydrodynamic pressure effect increases as shaft speed increasing, however it decreases as the impact of frictional heat.

  18. Filter characteristics influencing circulating tumor cell enrichment from whole blood.

    Directory of Open Access Journals (Sweden)

    Frank A W Coumans

    Full Text Available A variety of filters assays have been described to enrich circulating tumor cells (CTC based on differences in physical characteristics of blood cells and CTC. In this study we evaluate different filter types to derive the properties of the ideal filter for CTC enrichment. Between 0.1 and 10 mL of whole blood spiked with cells from tumor cell lines were passed through silicon nitride microsieves, polymer track-etched filters and metal TEM grids with various pore sizes. The recovery and size of 9 different culture cell lines was determined and compared to the size of EpCAM+CK+CD45-DNA+ CTC from patients with metastatic breast, colorectal and prostate cancer. The 8 µm track-etched filter and the 5 µm microsieve had the best performance on MDA-231, PC3-9 and SKBR-3 cells, enriching >80% of cells from whole blood. TEM grids had poor recovery of ∼25%. Median diameter of cell lines ranged from 10.9-19.0 µm, compared to 13.1, 10.7, and 11.0 µm for breast, prostate and colorectal CTC, respectively. The 11.4 µm COLO-320 cell line had the lowest recovery of 17%. The ideal filter for CTC enrichment is constructed of a stiff, flat material, is inert to blood cells, has at least 100,000 regularly spaced 5 µm pores for 1 ml of blood with a ≤10% porosity. While cell size is an important factor in determining recovery, other factors must be involved as well. To evaluate a filtration procedure, cell lines with a median size of 11-13 µm should be used to challenge the system.

  19. Potential of hyperspectral imaging to assess the stability of mudflat surfaces by mapping sediment characteristics

    Science.gov (United States)

    Smith, Geoff; Thomson, Andrew; Moller, Iris; Kromkamp, Jacco

    2003-03-01

    This work assessed the suitability of hyperspectral data for estimating mudflat surface characteristics related to stability. Due to the inaccessibility of intertidal areas, precise ground-based measurements of mudflat stability are difficult to conduct. Remote sensing can provide full spatial coverage and non-intrusive measurement. As stability changes on mudflats are linked to subtle differences in mudflat surface characteristics, they can potentially be mapped by hyperspectral data. Hyperspectral images were collected along with near contemporary ground measurements. An unsupervised classification gave a map which confirmed that a channel bar was mainly sand whereas soft mud dominated an adjacent embayment. Multiple regression analysis was used to relate surface characteristics to hyperspectral data to construct regression equations. Erosion shear stress was estimated directly from the hyperspectral data and also by a relationship with the surface characteristics. The results of the thematic class map matched well with the known situation at the site during image acquisition. The maps of surface characteristics highlighted the additional information that can be extracted from hyperspectral data. Stability maps, based on the erosion shear stress, can be used as a basis for predicting the likely future behaviour in this dynamic environment and will be of use for coastal zone management.

  20. Analysis of dynamic characteristics of stochastic influences in cognitive systems

    Directory of Open Access Journals (Sweden)

    Alexander A. Solodov

    2017-01-01

    Full Text Available The aim of the study is to provide an analytical description of the dynamics of the processes to form images in the cognitive system and their subsequent processing by the consciousness, as well as the study of the simplest characteristics of the quality of the cognitive system functioning in the form of the signal/noise ratio.In accordance with the ideas of the cognitive theory, it is believed that images (schemes, categories, Gestalt, systems, archetypes, etc. are firstly generated in the human brain and then processed by the consciousness.These images are formed at random in time and are characterized by a random force of effects and subsequently processed by the consciousness.The images are characterized by random numbers, the common interpretation of which is the amount of information corresponding to the appearance of a certain image. The times of appearance are points on the time axis; their number and position are random as well.The work consists of a logically completed model including the following components:• Justification of a statistical model of the appearance of effects during the operation of the cognitive system in the form of the Poisson point process, characterized by the intensity of occurrence of effects and the random values of those effects.• Development of a mathematical model in the consciousness processing of the random effects in the form of reducing response function, which depends on the current time, the time of occurrence of effects and the magnitudes of these effects. To obtain applied results, exponential response function was applied and the analytical results for the mathematical expectations of the processed and not processed information by the consciousness were received.• Introduction for consideration of the signal/noise ratio, characterizing the performance of cognitive systems in the presence of interference and study of its behavior in the situations with the presence of random background noise

  1. The relative influence of body characteristics on humid heat stress response

    NARCIS (Netherlands)

    Havenith, G.; Luttikholt, V. G.; Vrijkotte, T. G.

    1995-01-01

    The present study was designed to determine the relative importance of individual characteristics such as maximal oxygen uptake (VO2max), adiposity, DuBois body surface area (AD), surface to mass ratio (AD: mass) and body mass, for the individual's reaction to humid heat stress. For this purpose 27

  2. Surface passivation of HgCdTe by CdZnTe and its characteristics

    Science.gov (United States)

    Lee, T. S.; Choi, K. K.; Jeoung, Y. T.; Kim, H. K.; Kim, J. M.; Kim, Y. H.; Chang, J. M.; Song, W. S.; Kim, S. U.; Park, M. J.; Lee, S. D.

    1997-06-01

    In this paper, we report the results of capacitance-voltage measurements conducted on several metal-insulator semiconductor (MIS) capacitors in which HgCdTe surfaces are treated with various surface etching and oxidation processes. CdZnTe passivation layers were deposited on HgCdTe surfaces by thermal evaporation after the surfaces were etched with 0.5-2.0% bromine in methanol solution, or thin oxide layers (tox ˜ few ten Å) were grown on the surfaces, in order to investigate effects of the surface treatments on the electrical properties of the surfaces, as determined from capacitance-voltage (C-V) measurements at 80K and 1 MHz. A negative flat band voltage has been observed for MIS capacitors fabricated after etching of HgCdTe surfaces with bromine in methanol solutions, which is reported to make the surface Te-rich. It is inferred that residual Te on the surface is a positive charge, Te4+. C-V characteristics for MIS capacitors fabricated on oxide surfaces grown by air-exposure and electrolytic process have shown large hysteresis effects, from which it is inferred that imperfect and electrically active oxide compounds and HgTe particles near the surface become slow interface states.

  3. Characteristics of meter-scale surface electrical discharge propagating along water surface at atmospheric pressure

    Czech Academy of Sciences Publication Activity Database

    Hoffer, Petr; Sugiyama, Y.; Hosseini, S.H.R.; Akiyama, H.; Lukeš, Petr; Akiyama, M.

    2016-01-01

    Roč. 49, č. 41 (2016), č. článku 415202. ISSN 0022-3727 Institutional support: RVO:61389021 Keywords : water surface * spectroscopy * high-speed photography * pulsed plasma discharge * Atmospheric-pressure plasmas * electric discharges * liquids * water Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.588, year: 2016 http://iopscience.iop.org/article/10.1088/0022-3727/49/41/415202

  4. Influence of a nanoporous zirconia implant surface of on cell viability of human osteoblasts

    NARCIS (Netherlands)

    Aboushelib, M.N.; Osman, E.; Jansen, I.; Everts, V.; Feilzer, A.J.

    2013-01-01

    Purpose: The dense nonretentive surface of zirconia implants was modified into a nanoporous surface using selective infiltration etching surface treatment. The aim of this study was to investigate the influence of such a nanoporous modified zirconia surface on the attachment of human osteoblasts.

  5. Biochar production from coffee residues: Optimization of surface characteristics and sorptive behavior

    Science.gov (United States)

    Fotopoulou, Kalliopi; Manariotis, Ioannis D.; Karapanagioti, Hrissi K.

    2015-04-01

    Biochar with high surface area is a promising sorbent for environmental remediation and is produced by heating biomass in an oxygen-limited environment. Knowing the surface characteristics increases our understanding of biochar interactions with pollutants. The hypothesis of the present study is that by controlling pyrolysis conditions, the surface characteristics and subsequently the sorption behavior of produced biochars can be optimized. Coffee residues were dried overnight at 50oC and then pyrolized into a gradient furnace at 850oC. Different solid/oxygen ratios during pyrolysis were tested as well as the up scaling of the process. The biochars produced were systematically characterized for their surface characteristics such as BET surface area, open surface area, pore and micropore volume, and average pore size. The effect of pyrolysis on the biochar suspension pH was examined with the mass addition technique that involves the addition of increasing amounts of the biochar to bottles containing 0.1 M NaNO3. FTIR analysis was used in order to determine the functional groups of the coffee residue and of the biochars. The macrostructure of the biochars was visualized by Scanning Electron Microscopy (SEM). Total Carbon (TC) in the samples was determined by Carlo Erba Elemental Analyzer CHNS, EO 1108 after calibration with standard samples. The sorption behavior of produced biochars was tested with two different pollutants (Hg(II), phenanthrene) using batch reactors with the same initial single-compound solution and the same mass of coffee residue and different biochars. The biochars produced exhibited a wide range of surface area from 21 to 770 m2/g and open surface area due to macropores from 21 to 65 m2/g. This suggests that the surface area in the biochars with high surface area results from the formation of pores. Actually for the biochar with the highest surface area, it was calculated that up to 90

  6. Approaches for Controlled Ag+ Ion Release: Influence of Surface Topography, Roughness, and Bactericide Content.

    Science.gov (United States)

    Sukhorukova, I V; Sheveyko, A N; Shvindina, N V; Denisenko, E A; Ignatov, S G; Shtansky, D V

    2017-02-01

    Silver is the most famous bactericidal element known from ancient times. Its antibacterial and antifungal effects are typically associated with the Ag ionization and concentration of Ag + ions in a bacterial culture. Herein we thoroughly studied the influence of surface topography and roughness on the rate of Ag + ion release. We considered two types of biocompatible and bioactive TiCaPCON-Ag films with 1 and 2 at. % of Ag and nine types of Ti surfaces with an average roughness varying in the range from 5.4 × 10 -2 to 12.6 μm and different topographic features obtained through polishing, sandblasting, laser treatment, and pulsed electrospark deposition. It is demonstrated that the Ag + ion release rates do not depend on the Ag content in the films as the main parameter, and it is other factors, such as the state of Ag agglomeration, surface topography and roughness, as well as kinetics of surface oxidation, that play a critical role. The obtained results clearly show a synergistic effect of the Ag content in the film and surface topography and roughness on Ag + ion release. By changing the surface topographical features at a constant content of bactericidal element, we showed that the Ag + ion release can be either accelerated by 2.5 times or almost completely suppressed. Despite low Ag + ion concentration in physiological solution (antibacterial effect already after 3 h of immersion in E. coli bacterial culture. Thus, our results open up new possibilities for the production of cost-effective, scalable, and biologically safe implants with pronounced antibacterial characteristics for future applications in the orthopedic field.

  7. Prevalence and characteristics of ESBL-producing E. coli in Dutch recreational waters influenced by wastewater treatment plants.

    Science.gov (United States)

    Blaak, Hetty; de Kruijf, Patrick; Hamidjaja, Raditijo A; van Hoek, Angela H A M; de Roda Husman, Ana Maria; Schets, Franciska M

    2014-07-16

    Outside health care settings, people may acquire ESBL-producing bacteria through different exposure routes, including contact with human or animal carriers or consumption of contaminated food. However, contact with faecally contaminated surface water may also represent a possible exposure route. The current study investigated the prevalence and characteristics of ESBL-producing Escherichia coli in four Dutch recreational waters and the possible role of nearby waste water treatment plants (WWTP) as contamination source. Isolates from recreational waters were compared with isolates from WWTP effluents, from surface water upstream of the WWTPs, at WWTP discharge points, and in connecting water bodies not influenced by the studied WWTPs. ESBL-producing E. coli were detected in all four recreational waters, with an average concentration of 1.3 colony forming units/100ml, and in 62% of all samples. In surface waters not influenced by the studied WWTPs, ESBL-producing E. coli were detected in similar concentrations, indicating the existence of additional ESBL-E. coli contamination sources. Isolates with identical ESBL-genes, phylogenetic background, antibiotic resistance profiles, and sequence type, were obtained from effluent and different surface water sites in the same watershed, on the same day; occasionally this included isolates from recreational waters. Recreational waters were identified as a potential exposure source of ESBL-producing E. coli. WWTPs were shown to contribute to the presence of these bacteria in surface waters, but other (yet unidentified) sources likely co-contribute. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Identification card and codification of the chemical and morphological characteristics of 14 dental implant surfaces.

    Science.gov (United States)

    Dohan Ehrenfest, David M; Vazquez, Lydia; Park, Yeong-Joon; Sammartino, Gilberto; Bernard, Jean-Pierre

    2011-10-01

    Dental implants are commonly used in daily practice; however, most surgeons do not really know the characteristics of these biomedical devices they are placing in their patients. The objective of this work is to describe the chemical and morphological characteristics of 14 implant surfaces available on the market and to establish a simple and clear identification (ID) card for all of them, following the classification procedure developed in the Dohan Ehrenfest et al (2010) Codification (DEC) system. Fourteen implant surfaces were characterized: TiUnite (Nobel Biocare), Ospol (Ospol), Kohno HRPS (Sweden & Martina), Osseospeed (AstraTech), Ankylos (Dentsply Friadent), MTX (Zimmer), Promote (Camlog), BTI Interna (Biotechnology Institute), EVL Plus (SERF), Twinkon Ref (Tekka), Ossean (Intra-Lock), NanoTite (Biomet 3I), SLActive (ITI Straumann), Integra-CP/NanoTite (Bicon). Three samples of each implant were analyzed. Superficial chemical composition was analyzed using X-ray photoelectron spectroscopy/electron spectroscopy for chemical analysis, and the 100 nm in-depth profile was established using Auger electron spectroscopy. The microtopography was quantified using light interferometry. The general morphology and nanotopography were evaluated using a field emission-scanning electron microscope. Finally, the characterization code of each surface was established using the DEC system, and the main characteristics of each surface were summarized in a reader-friendly ID card. From a chemical standpoint, of the 14 different surfaces, 10 were based on a commercially pure titanium (grade 2 or 4), 3 on a titanium-aluminum alloy (grade 5 titanium), and one on a calcium phosphate core. Nine surfaces presented different forms of chemical impregnation or discontinuous coating of the titanium core, and 3 surfaces were covered with residual aluminablasting particles. Twelve surfaces presented different degrees of inorganic pollutions, and 2 presented a severe organic pollution

  9. Dynamic behavior of water droplets and flashover characteristics on a superhydrophobic silicone rubber surface

    Science.gov (United States)

    Li, Yufeng; Jin, Haiyun; Nie, Shichao; Zhang, Peng; Gao, Naikui

    2017-05-01

    In this paper, a superhydrophobic surface is used to increase the flashover voltage when water droplets are present on a silicone rubber surface. The dynamic behavior of a water droplet and the associated flashover characteristics are studied on common and superhydrophobic silicone rubber surfaces under a high DC voltage. On common silicone rubber, the droplet elongates and the flashover voltage decreases with increasing droplet volume and conductivity. In contrast, the droplet slides off the superhydrophobic surface, leading to an increased flashover voltage. This droplet sliding is due to the low adhesion of the superhydrophobic surface and a sufficiently high electrostatic force provided by the DC voltage. Experimental results show that a superhydrophobic surface is effective at inhibiting flashover.

  10. Influence of Mineralogical Characteristics of Iron Ore on Formation and Flow of Liquid Phase

    Science.gov (United States)

    Su, Bo; Wu, Sheng-li; Zhang, Guo-liang

    The mineralogical characteristics of iron ores can influence their high temperature sintering performance. In this study, eight iron ore samples from Brazil, Australia, and South Africa were characterized by their chemical composition, mineral types, particle morphology, and gangue dispersity. Meanwhile the influence rules between the mineralogical characteristics and the high temperature characteristics were evaluated and analyzed. The results showed that the effect of SiO2 on assimilation characteristic of iron ores was relatively complex, Al2O3 and LOI of iron ores had negative correlation with assimilation temperature of iron ores, the dense slab-flaky mineral granule restrained to the assimilation characteristics of iron ores; liquid phase of iron ores with high SiO2 content and low Al2O3 content had high fluidity, and the higher dispersity of gangue minerals in iron ores was good to the fluidity of liquid phase.

  11. An investigation on the effect of surface characteristics on adhesion between polymer melts and replication tools

    DEFF Research Database (Denmark)

    Delaney, Kevin D.; Kennedy, Jonathan David; Bissacco, Giuliano

    2012-01-01

    Understanding interfacial characteristics between a polymer and its associated tool surface is critical to successful optimization of processes such as injection moulding, embossing and extrusion used to produce polymer parts. One of the factors characterizing the strength of the polymer-tool int......Understanding interfacial characteristics between a polymer and its associated tool surface is critical to successful optimization of processes such as injection moulding, embossing and extrusion used to produce polymer parts. One of the factors characterizing the strength of the polymer...

  12. Influence of surface modification on friction coefficient of the titanium-elastomer couple.

    Science.gov (United States)

    Chladek, Wiesław; Hadasik, Eugeniusz; Chladek, Grzegorz

    2007-01-01

    This paper presents the results of a study of the friction coefficient of titanium-elastomer couple. The study was carried out with a view to potential future utilization of its results for constructing retentive elements of implanted prostheses. Changes in the friction force were recorded while removing titanium specimens placed between two silicone counter specimens made of Ufi Gel. The influence of the titanium specimen movement speed in relation that of to the counter specimens and the influence of clamping force on the friction force were assessed. Additionally, the surface roughness of titanium specimens differed; in one case, titanium was coated with polyethylene. The effect of introducing artificial saliva between the cooperating surfaces on the friction force and friction coefficient was analyzed as well. Based on the characteristics recorded, the possibilities of shaping the friction coefficient have been assessed, since it is the friction coefficient that determines effective operation of a friction couple through increasing the titanium specimen roughness. The artificial saliva being introduced between the specimens reduces considerably the friction coefficient through a change of the phenomenon model. An increase in the pressure force for the specimens of high roughness entails a reduction of the friction coefficient. The study carried out allows us to identify the roughness parameters, which in turn will enable obtaining the prescribed retention force for friction/membrane couplings.

  13. Sound propagation through a rarefied gas. Influence of the gas–surface interaction

    International Nuclear Information System (INIS)

    Kalempa, Denize; Sharipov, Felix

    2012-01-01

    Highlights: ► Non-equilibrium gas properties due to sound propagation. ► Influence of gas–surface accommodation coefficients. ► Heat transfer due to thermo-acoustic waves. ► Reciprocal relations. ► Range of validity of the Navier–Stokes equations. - Abstract: Acoustic waves propagating through a rarefied gas between two plates induced by both oscillation and unsteady heating of one of them are considered on the basis of a model of the linearized Boltzmann equation. The gas flow is considered as fully established so that the dependence of all quantities on time is harmonical. The problem is solved for several values of two main parameters determining its solution, namely, the gas rarefaction defined as the ratio of the distance between the plates to the equivalent free path of gaseous molecules, and the oscillation parameter given as the ratio of the intermolecular collision frequency to the wave frequency. The reciprocal relation for such flows is obtained and verified numerically. An influence of the gas–surface accommodation coefficients on the wave characteristics is analyzed by employing the Cercignani–Lampis scattering kernel to the boundary conditions.

  14. Influence of Forest Cutting and Mountain Farming on some Vegetation, Surface Soil and Surface Runoff Characteristics

    Science.gov (United States)

    Robert E. Dils

    1953-01-01

    With the increasing demands made on our water supplies within the past few decades has come the realization that fundamental research concerning this basic natural resource is woefully lacking. Because the water resource is so closely linked with climate, it was the consensus of opinion for many centuries that man could alter it no more than he could the weather. This...

  15. Influence of wastewater characteristics on methane potential in food-processing industry wastewaters

    DEFF Research Database (Denmark)

    Maya Altamira, Larisa; Baun, Anders; Angelidaki, Irini

    2008-01-01

    In this study, we identified the influence of wastewater characteristics on the theoretical and practical methane potential using different food industrial wastewaters as substrates. Ten composite wastewater samples from five industries were investigated. The ultimate practical methane yields (Bo......) were compared to the theoretical methane yields (Bo,th) in order to evaluate the biodegradability of the tested wastewaters and the influence of their physico-chemical characteristics. The analytical method applied to quantify the wastewaters’ organic content proved to influence the estimation...... of their theoretical yields. The substrate:inoculum ratio as well as the dilution factor of the wastewaters influenced the ultimate practical methane yields differently in each of the wastewaters assessed. Substrate chemical oxygen demand (COD) concentrations did not present any influence on ultimate practical methane...

  16. Surface characteristics of bioactive Ti fabricated by chemical treatment for cartilaginous-integration.

    Science.gov (United States)

    Miyajima, Hiroyuki; Ozer, Fusun; Imazato, Satoshi; Mante, Francis K

    2017-09-01

    Artificial hip joints are generally expected to fail due to wear after approximately 15years and then have to be replaced by revision surgery. If articular cartilage can be integrated onto the articular surfaces of artificial joints in the same way as osseo-integration of titanium dental implants, the wear of joint implants may be reduced or prevented. However, very few studies have focused on the relationship between Ti surface and cartilage. To explore the possibility of cartilaginous-integration, we fabricated chemically treated Ti surfaces with H 2 O 2 /HCl, collagen type II and SBF, respectively. Then, we evaluated surface characteristics of the prepared Ti samples and assessed the cartilage formation by culturing chondrocytes on the Ti samples. When oxidized Ti was immersed in SBF for 7days, apatite was formed on the Ti surface. The surface characteristics of Ti indicated that the wettability was increased by all chemical treatments compared to untreated Ti, and that H 2 O 2 /HCl treated surface had significantly higher roughness compared to the other three groups. Chondrocytes produced significantly more cartilage matrix on all chemically treated Ti surfaces compared to untreated Ti. Thus, to realize cartilaginous-integration and to prevent wear of the implants in joints, application of bioactive Ti formed by chemical treatment would be a promising and effective strategy to improve durability of joint replacement. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Influence of graphite and serpentine minerals along landslide failure surfaces

    Science.gov (United States)

    Alberti, Stefano; Battista Crosta, Giovanni; Wang, Gonghui; Dattola, Giuseppe; Bertolo, Davide

    2017-04-01

    Landslides and deep-seated gravitational slope deformation (DSGSD) often are concentrated in sedimentary and metasedimentary rocks (e.g. Ambrosi and Crosta, 2006) and in carbonaceous materials (CM), where weaker slip surfaces can be generated more easily, with a behaviour similar to that of fault zone (e.g. Zulauf et al., 1990; Craw, 2002; Oohashi et al., 2011, Nakamura et al., 2015). Among the carbonaceous minerals, graphite (grouped with other silicate sheet minerals) acts as a "solid lubrificant" and plays a key role on frictional properties of the slip surface (Yamasaki et al., 2015). These minerals have one key characteristic in common: the presence of weak bonding along (001) planes. Graphite also has one of the weakest bonding in the crystal structure, and it is characterized by a markedly low coefficient of friction (ca 0.1). A similar behaviour is found in serpentine minerals series and chlorite. We performed these tests on different samples derived from Mont de La Saxe landslide and Chervaz landslide. The first one is located in the upper Aosta Valley, the second in the central part of the Aosta Valley. Both these landslides are characterized by metasedimentary sequences. The undisturbed samples derived by core recovery surveys. We performed a petrographic characterization by XRD (X-Ray Diffraction), XRF (X-Ray Refraction) and SEM (Scansion Electron Microscope) with microprobe in addition to laboratory tests on samples from shear zones. Along these shear zones grains are crushed, their size and shapes are changed and these changes necessarily affect pore-water pressure due to volume change in the shear zone. We performed tests using a dynamic-loading ring-shear apparatus (DPRI-5, Sassa et al., 1997). This apparatus allows to simulate the entire process of failure, from initial static or dynamic loading, through shear failure, pore-pressure changes and possible liquefaction, to large-displacement, steady-state shear movement. It is also possible to

  18. Bacteriophage T4 Nanoparticles as Materials in Sensor Applications: Variables That Influence Their Organization and Assembly on Surfaces

    Directory of Open Access Journals (Sweden)

    Jinny L. Liu

    2009-08-01

    Full Text Available Bacteriophage T4 nanoparticles possess characteristics that make them ideal candidates as materials for sensors, particularly as sensor probes. Their surface can be modified, either through genetic engineering or direct chemical conjugation to display functional moieties such as antibodies or other proteins to recognize a specific target. However, in order for T4 nanoparticles to be utilized as a sensor probe, it is necessary to understand and control the variables that determine their assembly and organization on a surface. The aim of this work is to discuss some of variables that we have identified as influencing the behavior of T4 nanoparticles on surfaces. The effect of pH, ionic strength, substrate characteristics, nanoparticle concentration and charge was addressed qualitatively using atomic force microscopy (AFM.

  19. How do features of dressage arenas influence training surface properties which are potentially associated with lameness?

    Science.gov (United States)

    Murray, Rachel C; Walters, Juli; Snart, Hannah; Dyson, Sue; Parkin, Tim

    2010-11-01

    Results from a previous study indicated that there are specific arena surface characteristics that are associated with an increased likelihood of lameness in dressage horses. It is important to understand what modifiable arena factors lead to these detrimental surface characteristics. The aim of this study was to describe the use of training surfaces and arenas for United Kingdom dressage horses and to investigate any relationships between arena/surface variables and detrimental surface characteristics. Data from a questionnaire returned by 22.5% of all 11,363 registered members of British Dressage were used for the study. Univariate and multivariable logistic regression models were developed with each of the previously identified surface characteristics as dependent variables. Respondents reported that the majority of arenas were privately owned, sized 20 × 40 m and had a sand and rubber surface. The results indicated that wax-coated and sand and rubber surfaces were associated with less detrimental surface properties than sand, sand and PVC, woodchips or grass. Woodchips were most strongly associated with the detrimental characteristic of slipping, and sand with tripping. The findings indicated that any arena surface should have a base, with limestone the recommended surface, and that crushed concrete was best avoided. This information supported previous studies in racehorses that indicated that surface maintenance is essential, especially when many horses are using an arena daily. Problems were less likely if an arena was privately owned. Copyright © 2010. Published by Elsevier Ltd.

  20. The effects of crushing surface roughness on the crushing characteristics of composite tubes

    Science.gov (United States)

    Farley, Gary L.; Wolterman, Richard L.; Kennedy, John M.

    1992-01-01

    The effects of crushing-surface roughness on the energy-absorption capability of graphite and glass-epoxy composite tubes were investigated. Fifty different combinations of fiber, matrix, and specimen ply orientation were evaluated. Two different crushing surface roughnesses were used in this investigation. Crushing surface significantly influences the energy-absorption capability only of tubes that crush in the lamina bending crushing mode; tubes that crush in other modes are not influenced because their lamina bundles do not slide against the crushing surface. Those tubes that crush in the lamina bending mode can achieve higher, lower, or no change in energy-absorption capability as crushing surface roughness increases. If the fiber failure strain of tubes that crush in the lamina bending crushing mode exceeds the matrix failure strain then the energy-absorption capability increases as crushing surface roughness increases. However, if the matrix failure strain exceeds the fiber failure strain then the energy-absorption capability increases as crushing surface roughness decreases. Energy-absorption capability is uninfluenced by crushing surface roughness for tubes that have equal fiber and matrix failure strains.

  1. Does the microclimate under hail nets influence micromorphological characteristics of apple leaves and cuticles?

    Science.gov (United States)

    Hunsche, Mauricio; Blanke, Michael M; Noga, Georg

    2010-08-15

    A higher frequency of hail storms, possibly due to climate change, has led to increased installation of hail nets worldwide. The objective of the present work was to investigate potential effects of the microclimate under these hail nets on micromorphological characteristics of the leaves and adaxial leaf cuticles. Leaves of apple cultivars 'Pinova' and 'Fuji' grown on trees under white (highly translucent) or red-black (low transmittance) hail nets or on uncovered (control) trees were evaluated in June, August, September and October. The microclimate under the colored hail nets had no impact on leaf micromorphology, amount of cuticular wax, or leaf thickness. Similarly, no differences in thickness and permeability for calcium could be established between cuticles of leaves grown on trees under the two types of hail nets or uncovered trees. For all evaluated parameters, significant differences were detected between the two cultivars examined. In both cultivars, leaf wax synthesis followed a characteristic curve, increasing from the first to the second evaluation, and then decreasing continuously without affecting cuticular penetration of calcium. Overall, our results show that a reduction of the hail nets by 6-10% in both light and humidity was insufficient to influence the surface properties of apple leaves and permeability of cuticles. This may suggest that pest management strategies, i.e. formulation of agrochemicals, their application and dose, do not need to be adapted when used under hail nets. Overall, the present results indicate that the microclimatic changes brought about by colored hail nets are sufficient to enhance the vegetative growth and induce the 'shade avoidance syndrome', but do not appear to affect the leaf cuticular properties. Copyright 2010 Elsevier GmbH. All rights reserved.

  2. Microbiological influenced corrosion resistance characteristics of a 304L-Cu stainless steel against Escherichia coli.

    Science.gov (United States)

    Nan, Li; Xu, Dake; Gu, Tingyue; Song, Xiu; Yang, Ke

    2015-03-01

    Cu-bearing antibacterial stainless steels have been gaining popularity in recent years due to their strong antibacterial performances. However, only a few studies were reported for their actual performances against microbiologically influenced corrosion (MIC). In this study, electrochemical methods and surface analytical techniques were applied to study the MIC resistance characteristics of a 304L-Cu stainless steel (SS) against Escherichia coli in comparison with 304L SS as control. Corrosion tests for specimens after a 21-day exposure to a Luria-Bertani (LB) culture medium with E. coli demonstrated that the 304L-Cu SS considerably reduced the maximum MIC pit depth and the specific weight loss compared with 304L SS (8.3μm and 0.2mg/cm(2) vs. 13.4μm and 0.6mg/cm(2)). Potentiodynamic polarization tests showed that the corrosion current density of the 304L-Cu SS was as much as 4 times lower than that of the 304L SS, indicating that the 304L-Cu SS is a better choice for applications in MIC-prone environments. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Comparison of biological characteristics of mesenchymal stem cells grown on two different titanium implant surfaces

    International Nuclear Information System (INIS)

    Wang Chengyue; Zhao Baohong; Ai Hongjun; Wang Yiwei

    2008-01-01

    This study examined the biological characteristics of mesenchymal stem cells (MSCs) grown on sand-blasted, large-grit, acid-etched (SLA) surface and hydroxyapatite (HA) coating on the SLA (HA/SLA) surface of titanium dental implants. The HA/SLA surfaces of titanium dental implants were formed by the ion beam assisted deposition (IBAD) method. Rabbit bone marrow derived mesenchymal stem cells cultured in vitro were seeded onto the surface of SLA and HA/SLA; the growth states of MSCs on the two samples were observed by a scanning electron microscope; the proliferation index, alkaline phosphatase (ALP) activity, osteocalcin (OCN) content of MSCs and mRNA relative expression level of osteopontin (opn) were compared between two groups. MSCs were found to be easier to adhere to the HA/SLA surface compared to the SLA surface. At the same time, the ALP activity and the OCN content of MSCs grown on the HA/SLA surface were obviously higher, and the relative expression level of opn mRNA was 4.78 times higher than that on the SLA surface. The HA coating formed by the IBAD method on the SLA surface of titanium dental implants significantly improves proliferation and well-differentiated osteoblastic phenotype of MSCs, which indicates a promising method for the surface modification of titanium dental implants

  4. Characteristics of Asperity Damage and Its Influence on the Shear Behavior of Granite Joints

    Science.gov (United States)

    Meng, Fanzhen; Zhou, Hui; Wang, Zaiquan; Zhang, Chuanqing; Li, Shaojun; Zhang, Liming; Kong, Liang

    2018-02-01

    Surface roughness significantly affects the shear behavior of rock joints; thus, studies on the asperity damage characteristics and its influence on the shear behavior of joints are extremely important. In this paper, shear tests were conducted on tensile granite joints; asperity damage was evaluated based on acoustic emission (AE) events; and the influence of asperity damage on joint shear behavior was analyzed. The results indicated that the total AE events tended to increase with normal stress. In addition, the asperity damage initiation shear stress, which is defined as the transition point from slow growth to rapid growth in the cumulative events curve, was approximately 0.485 of the peak shear strength regardless of the normal stress. Moreover, 63-85% of the AE events were generated after the peak shear stress, indicating that most of the damage occurred in this stage. Both the dilation and the total AE events decreased with shear cycles because of the damage inflicted on asperities during the previous shear cycle. Two stages were observed in the normal displacement curves under low normal stress, whereas three stages (compression, dilation and compression again) were observed at a higher normal stress; the second compression stage may be caused by tensile failure outside the shear plane. The magnitude of the normal stress and the state of asperity are two important factors controlling the post-peak stress drop and stick-slip of granite joints. Serious deterioration of asperities will stop stick-slip from recurring under the same normal stress because the ability to accumulate energy is decreased. The AE b-value increases with the number of shear cycles, indicating that the stress concentration inside the fault plane is reduced because of asperity damage; thus, the potential for dynamic disasters, such as fault-slip rockbursts, will be decreased.

  5. Surface influence on convoy electron emission at low energies

    International Nuclear Information System (INIS)

    Sanchez, E.A.

    1988-01-01

    It is studied the dependence of the production of convoy electrons induced by H + - 60 KeV with surface conditions of Al targets by in situ deposition of Na and O. The conclusion is that convoy electron production increases with the work function of the surface. (A.C.A.S.) [pt

  6. Surface plasma functionalization influences macrophage behavior on carbon nanowalls

    Energy Technology Data Exchange (ETDEWEB)

    Ion, Raluca [University of Bucharest, Department of Biochemistry and Molecular Biology, 91-95 Spl. Independentei, 050095 Bucharest (Romania); Vizireanu, Sorin [National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor, PO Box MG-36, 077125, Magurele, Bucharest (Romania); Stancu, Claudia Elena [National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor, PO Box MG-36, 077125, Magurele, Bucharest (Romania); Leibniz Institute for Plasma Science and Technology (INP Greifswald), Felix-Hausdorff-Str. 2, 17489 Greifswald (Germany); Luculescu, Catalin [National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor, PO Box MG-36, 077125, Magurele, Bucharest (Romania); Cimpean, Anisoara, E-mail: anisoara.cimpean@bio.unibuc.ro [University of Bucharest, Department of Biochemistry and Molecular Biology, 91-95 Spl. Independentei, 050095 Bucharest (Romania); Dinescu, Gheorghe [National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor, PO Box MG-36, 077125, Magurele, Bucharest (Romania)

    2015-03-01

    The surfaces of carbon nanowall samples as scaffolds for tissue engineering applications were treated with oxygen or nitrogen plasma to improve their wettability and to functionalize their surfaces with different functional groups. X-ray photoelectron spectroscopy and water contact angle results illustrated the effective conversion of the carbon nanowall surfaces from hydrophobic to hydrophilic and the incorporation of various amounts of carbon, oxygen and nitrogen functional groups during the treatments. The early inflammatory responses elicited by un-treated and modified carbon nanowall surfaces were investigated by quantifying tumor necrosis factor-alpha and macrophage inflammatory protein-1 alpha released by attached RAW 264.7 macrophage cells. Scanning electron microscopy and fluorescence studies were employed to investigate the changes in macrophage morphology and adhesive properties, while MTT assay was used to quantify cell proliferation. All samples sustained macrophage adhesion and growth. In addition, nitrogen plasma treatment was more beneficial for cell adhesion in comparison with un-modified carbon nanowall surfaces. Instead, oxygen plasma functionalization led to increased macrophage adhesion and spreading suggesting a more activated phenotype, confirmed by elevated cytokine release. Thus, our findings showed that the chemical surface alterations which occur as a result of plasma treatment, independent of surface wettability, affect macrophage response in vitro. - Highlights: • N{sub 2} and O{sub 2} plasma treatments alter the CNW surface chemistry and wettability. • Cells seeded on CNW scaffolds are viable and metabolically active. • Surface functional groups, independent of surface wettability, affect cell response. • O{sub 2} plasma treatment of CNW leads to a more activated macrophage phenotype.

  7. [Surface Property and Sorption Characteristics of Phosphorus onto Surface Sediments in Sanggou Bay].

    Science.gov (United States)

    Zhu, Jia-mei; Cao, Xiao-yan; Liu, Su-mei; Wang, Li-sha; Yang, Gui-peng; Ge, Cheng-feng; Lu, Min

    2016-02-15

    Kinetic curves and isotherms were investigated to study the sorption mechanism of phosphorus onto the sediments of Sanggou Bay, together with the surface charge properties of sediments and the forms of phosphorus studied. The results showed that the sorption including a fast process and a slow one, and could be described by a two-compartment first order equation. The thermodynamic isotherms were well fitted with a modified Langmuir equation. The maximum adsorption capacity was larger in summer than in spring, and the smaller particle size was favorable to the sorption. The maximum adsorption capacities (Qm) were 0.0471-0.1230 mg x g(-1), and the zero equilibrium phosphorus concentration (EPC0) of the sediments ranged from 0.0596 mg x L(-1) to 0.1927 mg x L(-1), which indicated that the sediments from Sanggou Bay were sources of phosphorus. Inorganic phosphorus (IP) was the main form of total phosphorus (TP). The contents of exchangeable or loosely absorbed P and Fe-bound P increased significantly in the samples after sorption. The sorption process involved physical sorption and chemical sorption, with the former being the predominant.

  8. Spatio-temporal variations in surface characteristics over the North American Monsoon region

    Science.gov (United States)

    In this paper we summarize the surface characteristics for six locations in western Mexico and southwestern USA (from a subhumid climate in Jalisco, Mexico to the Sonoran Desert climate in Arizona, USA),that lie along a meridional transect within the North American Monsoon (NAM) core region using av...

  9. Leaf size and surface characteristics of Betula papyrifera exposed to elevated CO2 and O3

    Science.gov (United States)

    Johanna Riikonen; Kevin E. Percy; Minna Kivimaenpaa; Mark E. Kubiske; Neil D. Nelson; Elina Vapaavuori; David F. Karnosky

    2010-01-01

    Betula papyrifera trees were exposed to elevated concentrations of CO2 (1.4 x ambient), O3 (1.2 x ambient) or CO2 + O3 at the Aspen Free-air CO2 Enrichment Experiment. The treatment effects on leaf surface characteristics were studied...

  10. Surface characteristics analysis of dry EDMed AISI D2 steel using modified tool design

    International Nuclear Information System (INIS)

    Pragadish, N.; Kumar, M. Pradeep

    2015-01-01

    A modified tool design is proposed which helps in drilling holes without any central core, and also enables the effective removal of the debris particles. Experiments were conducted on AISI D2 Steel using copper electrode as tool in both conventional EDM and dry EDM processes and the performance of both processes is compared. Experiments were designed using Taguchi's L27 orthogonal array. Discharge current (I), gap voltage (V), pulse on time (T ON ), gas pressure (P) and tool rotational speed (N) were chosen as the various input parameters, and their effect on the material removal rate (MRR), surface roughness (SR), surface morphology, microstructure and elemental composition of the machined surface is analyzed. The experimental results show better surface characteristics in the surface machined under dry EDM process.

  11. The Influence of Industry Characteristics and Dynamic Capabilities on Firms’ Profitability

    Directory of Open Access Journals (Sweden)

    Maja Pervan

    2017-12-01

    Full Text Available The aim of this research was to explore one of the most intriguing dimensions of every firm’s business—its performance. Aside from analysing the influence of industry’s characteristics on the firm’s performance, the authors addressed the characteristics of dynamic capabilities and their role in contribution to the firm’s ultimate success. The analysis was conducted on a sample of 118 small Croatian manufacturing companies. The application of the Structural Equation Modelling (SEM approach revealed a statistically significant influence of both the industry’s characteristics (represented by Porter’s five forces framework and dynamic capabilities (based on Teece’s theory on the firm’s performance, where the influence of dynamic capabilities is proven to be larger than that of the industry.

  12. The influence of vegetation and soil characteristics on active-layer thickness of permafrost soils in boreal forest.

    Science.gov (United States)

    Fisher, James P; Estop-Aragonés, Cristian; Thierry, Aaron; Charman, Dan J; Wolfe, Stephen A; Hartley, Iain P; Murton, Julian B; Williams, Mathew; Phoenix, Gareth K

    2016-09-01

    Carbon release from thawing permafrost soils could significantly exacerbate global warming as the active-layer deepens, exposing more carbon to decay. Plant community and soil properties provide a major control on this by influencing the maximum depth of thaw each summer (active-layer thickness; ALT), but a quantitative understanding of the relative importance of plant and soil characteristics, and their interactions in determine ALTs, is currently lacking. To address this, we undertook an extensive survey of multiple vegetation and edaphic characteristics and ALTs across multiple plots in four field sites within boreal forest in the discontinuous permafrost zone (NWT, Canada). Our sites included mature black spruce, burned black spruce and paper birch, allowing us to determine vegetation and edaphic drivers that emerge as the most important and broadly applicable across these key vegetation and disturbance gradients, as well as providing insight into site-specific differences. Across sites, the most important vegetation characteristics limiting thaw (shallower ALTs) were tree leaf area index (LAI), moss layer thickness and understory LAI in that order. Thicker soil organic layers also reduced ALTs, though were less influential than moss thickness. Surface moisture (0-6 cm) promoted increased ALTs, whereas deeper soil moisture (11-16 cm) acted to modify the impact of the vegetation, in particular increasing the importance of understory or tree canopy shading in reducing thaw. These direct and indirect effects of moisture indicate that future changes in precipitation and evapotranspiration may have large influences on ALTs. Our work also suggests that forest fires cause greater ALTs by simultaneously decreasing multiple ecosystem characteristics which otherwise protect permafrost. Given that vegetation and edaphic characteristics have such clear and large influences on ALTs, our data provide a key benchmark against which to evaluate process models used to predict

  13. Water environmental planning considering the influence of non-linear characteristics.

    Science.gov (United States)

    Zeng, Guang-ming; Qin, Xiao-sheng; Wang, Wei; Huang, Guo-he; Jian-bing, Li; Statzner, B

    2003-11-01

    In practical water environmental planning, the influence of the non-linear characteristics on the benefit of environmental investment was seldom taken into consideration. This paper demonstrates that there exist a lot of non-linear behaviors in water environment by emphatically analyzing the influence of the non-linear characteristics of the economic scale, the meandering river and the model on water environmental planning, which will make a certain impact on the water environmental planning that sometimes cannot be neglected. This paper also preliminarily explores how to integrate the non-linear characteristics into water environmental planning. The results showed that compared with traditional methods, water environmental planning considering non-linear characteristics has its prevalence and it is necessary to develop the relevant planning theories and methods.

  14. Influence of water on the surface of graphene

    Science.gov (United States)

    Kaya, Yunus; Kalkan, Yalçin; Veenhof, Rob

    2018-02-01

    We have studied how water modifies the surface of graphene and in particular how the surface conductivity of graphene is affected. According to the literature, two types of interactions should be distinguished: physical, where a water molecule remains intact and is located at some distance from the mesh, and chemical, where a water molecule is imbricated in the graphene bond structure. We have developed theoretical models for both types of interactions using the density functional theory (DFT) with the B3LYP hybrid functional combined with the 6-31G(d) basis set. Our calculations show that the surface conductivity of graphene is reduced in the presence of water.

  15. Surface characteristics determining the cell compatibility of ionically cross-linked alginate gels

    International Nuclear Information System (INIS)

    Machida-Sano, Ikuko; Hirakawa, Makoto; Matsumoto, Hiroki; Kamada, Mitsuki; Ogawa, Sakito; Satoh, Nao; Namiki, Hideo

    2014-01-01

    In this study we investigated differences in the characteristics determining the suitability of five types of ion (Fe 3+ , Al 3+ , Ca 2+ , Ba 2+ and Sr 2+ )-cross-linked alginate films as culture substrates for cells. Human dermal fibroblasts were cultured on each alginate film to examine the cell affinity of the alginates. Since cell behavior on the surface of a material is dependent on the proteins adsorbed to it, we investigated the protein adsorption ability and surface features (wettability, morphology and charge) related to the protein adsorption abilities of alginate films. We observed that ferric, aluminum and barium ion-cross-linked alginate films supported better cell growth and adsorbed higher amounts of serum proteins than other types. Surface wettability analysis demonstrated that ferric and aluminum ion-cross-linked alginates had moderate hydrophilic surfaces, while other types showed highly hydrophilic surfaces. The roughness was exhibited only on barium ion-cross-linked alginate surface. Surface charge measurements revealed that alginate films had negatively charged surfaces, and showed little difference among the five types of gel. These results indicate that the critical factors of ionically cross-linked alginate films determining the protein adsorption ability required for their cell compatibility may be surface wettability and morphology. (paper)

  16. Electrochemical Characteristics of Titanium for Dental Implants in Case of the Electroless Surface Modification

    Directory of Open Access Journals (Sweden)

    Klimecka-Tatar D.

    2016-06-01

    Full Text Available In the paper the results of research under effect of electroless phosphate coating of titanium dental implants on potentiokinetic polarization characteristic obtained in artificial saliva were presented. On the basis of electrochemical studies it was concluded that the electroless process of phosphating beneficialy effect on corrosion characteristic of titanium determined in solution simulating the oral cavity. Furthermore, the proposed technique of chemical treatment of titanium surface is conducive to the homogeneous development of the surface, which is extremely important from the point of view of titanium implants biointegration. Phosphating treatment affect on the development of surface geometry, resulting in a slight increase in roughness parameters (Ra, Rz and Rmax. The temperature increase of electroless phosphating treatment promotes the rate of conversion layer formation, whereas the effect of temperature of the chemical treatment efficiency is secondary important at longer exposure times (e.g. 45 minutes.

  17. An Assessment of Land Surface and Lightning Characteristics Associated with Lightning-Initiated Wildfires

    Science.gov (United States)

    Coy, James; Schultz, Christopher J.; Case, Jonathan L.

    2017-01-01

    Can we use modeled information of the land surface and characteristics of lightning beyond flash occurrence to increase the identification and prediction of wildfires? Combine observed cloud-to-ground (CG) flashes with real-time land surface model output, and Compare data with areas where lightning did not start a wildfire to determine what land surface conditions and lightning characteristics were responsible for causing wildfires. Statistical differences between suspected fire-starters and non-fire-starters were peak-current dependent 0-10 cm Volumetric and Relative Soil Moisture comparisons were statistically dependent to at least the p = 0.05 independence level for both polarity flash types Suspected fire-starters typically occurred in areas of lower soil moisture than non-fire-starters. GVF value comparisons were only found to be statistically dependent for -CG flashes. However, random sampling of the -CG non-fire starter dataset revealed that this relationship may not always hold.

  18. Influence of surface treatment on the oxidation behavior of zirconium and zircaloy-4

    International Nuclear Information System (INIS)

    Costa, I.; Ramanathan, L.V.

    1986-01-01

    The influence of fluoride concentration in surface treatment solutions on the oxidation behavior of Zr and Zircaloy-4 in the temperature range 350-760 0 C have been studied by means of thermogravimetric analysis. Two solutions containing different concentrations of hydrofluoric acid have been used for surface treatments, following which surface roughness measurements were also carried out. The influence of fluoride ion concentration on oxidation behavior has been found to be significant at higher temperatures. (Author) [pt

  19. Influence of stress factors and socio-demographic characteristics on the sleep quality of nursing students

    OpenAIRE

    Benavente, Sonia Betzabeth Ticona; Silva, Rodrigo Marques da; Higashi, Aline Baraldi; Guido, Laura de Azevedo; Costa, Ana Lucia Siqueira

    2014-01-01

    Objective:To analyze the influence of stress factors and socio-demographic characteristics on the sleep quality of nursing students. Method: An analytical cross-sectional and quantitative study, conducted with 151 nursing students in São Paulo between March and April of 2012. A form for socio-demographic characteristics, the Instrument to Evaluate Stress in Nursing Students and the Pittsburgh Sleep Index were applied. Results: High levels of stress was predominant for Time Management (27.8%) ...

  20. Influence of real photons diffraction contribution on parametric X-ray observed characteristics

    Science.gov (United States)

    Laktionova, S. A.; Pligina, O. O.; Sidnin, M. A.; Vnukov, I. E.

    2014-05-01

    It is proposed and implemented a simple method of calculating of the output of the diffracted real photons of bremsstrahlung and transition radiation from perfect crystals of arbitrary thickness up to a primary extinction lengths. It is shown that for small thickness of crystals and observation angles concerning the center of the diffraction of reflex, contribution of diffraction of real photon is comparable with the output of parametric X-radiation. Influence of experimental equipment characteristic on observed characteristics of radiation is discussed.

  1. Site Characteristics Influencing the Translation of Clinical Research Into Clinical Practice

    DEFF Research Database (Denmark)

    Smed, Marie; Getz, Kenneth A.

    2014-01-01

    Investigative sites participating in clinical trials play an instrumental role in aiding market adoption. Site experiences in clinical research help physician investigators and research professionals gain familiarity with and exposure to investigational treatments. This knowledge may be passed...... on to sponsor companies and may ultimately assist in positioning new products and driving commercialization success. This study evaluates site characteristics that influence the acquisition and sharing of knowledge gained through clinical trial experience. The impact of 2 central site characteristics...

  2. The Influence of Wind on HF Radar Surface Current Forecasts

    National Research Council Canada - National Science Library

    De Almeida, Francisco M

    2008-01-01

    The ability to predict surface currents can have a beneficial impact in several activities, such as Search and Rescue and Oil Spill Response, as well as others more purely scientific, operational or economic...

  3. Shaft Position Influence on Technical Characteristics of Universal Two-Stages Helical Speed Reducers

    OpenAIRE

    Мilan Rackov; Zeljko Kanovic; Sinisa Kuzmanovic; Ruzica Trbojevic

    2005-01-01

    Purchasers of speed reducers decide on buying those reducers, that can the most approximately satisfy their demands with much smaller costs. Amount of used material, ie. mass and dimensions of gear unit influences on gear units price. Mass and dimensions of gear unit, besides output torque, gear unit ratio and efficiency, are the most important parameters of technical characteristics of gear units and their quality. Centre distance and position of shafts have significant influence on output t...

  4. The Influence of Redundant Structural System Characteristics on the Value of SHM Information

    DEFF Research Database (Denmark)

    Thöns, Sebastian

    2015-01-01

    This paper addresses the influence of deteriorating structural system characteristics on the value of structural health monitoring (SHM) before its implementation. The value of SHM is quantified as the difference between the life cycle benefits with and without SHM for a structural system subjected...... to fatigue deterioration. The results indicate that the value of SHM is strongly influenced by the component reliability, comparably moderately by the resistance correlation and conditional moderately by the deterioration correlation between the structural components....

  5. Influence of the Human Activity on the Propagation Characteristics of 60 GHz Indoor Channels

    OpenAIRE

    Collonge , Sylvain; Zaharia , Gheorghe; El Zein , Ghais

    2003-01-01

    International audience; The 60 GHz frequency band appears to he very promising for wireless multimedia services in the next years. The 60 GHz propagation channel has to he accurately characterized for an appropriate design of high data rate systems (>IO0 Mh/s). In this paper, our interest is to determine the influence of the human activity on the propagation characteristics at 60 GHz. This influence is hardly ever taking into account in the published studies on the 60 GHz channel characteriza...

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

    Science.gov (United States)

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

    2013-11-01

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

  7. Effect of Autoclave Cycles on Surface Characteristics of S-File Evaluated by Scanning Electron Microscopy.

    Science.gov (United States)

    Razavian, Hamid; Iranmanesh, Pedram; Mojtahedi, Hamid; Nazeri, Rahman

    2016-01-01

    Presence of surface defects in endodontic instruments can lead to unwanted complications such as instrument fracture and incomplete preparation of the canal. The current study was conducted to evaluate the effect of autoclave cycles on surface characteristics of S-File by scanning electron microscopy (SEM). In this experimental study, 17 brand new S-Files (#30) were used. The surface characteristics of the files were examined in four steps (without autoclave, 1 autoclave cycle, 5 autoclave cycles and 10 autoclave cycles) by SEM under 200× and 1000× magnifications. Data were analyzed using the SPSS software and the paired sample t-test, independent sample t-test and multifactorial repeated measures ANOVA. The level of significance was set at 0.05. New files had debris and pitting on their surfaces. When the autoclave cycles were increased, the mean of surface roughness also increased at both magnifications (Pautoclave increased the surface roughness of the files and this had was directly related to the number of autoclave cycles.

  8. The influence of a thin gold film on the optical spectral characteristics of a porous anodic aluminum-oxide membrane

    Science.gov (United States)

    Ushakov, N. M.; Vasilkov, M. Yu.; Fedorov, F. S.

    2017-07-01

    We have experimentally studied how a thin mesostructured gold film, deposited onto one side of a porous anodic aluminum-oxide membrane, influences its optical spectral characteristics in a 200-900 nm wavelength range. It is established that the gold film only modifies the spectral characteristics of the composite membrane at light wavelengths above 500 nm. The presence of a thin gold film ensures the surface conductivity of membrane on a level of 3.4 × 106 Ω-1 m-1, retains optical transparency within 10-20%, leads to the appearance of anomalous dispersion in the long-wavelength part of the transmission spectrum, and reduces the bandgap width from 5.61 eV (in anodic aluminum oxide) to 4.51 eV (in the composite). The obtained anodic aluminum-oxide membranes with thin gold films can be used as transparent conducting electrodes in optoelectronic devices with large light transmitter/receiver active areas.

  9. Influence of the carbon fiber surface microstructure on the surface chemistry generated by a thermo-chemical surface treatment

    International Nuclear Information System (INIS)

    Vautard, F.; Ozcan, S.; Paulauskas, F.; Spruiell, J.E.; Meyer, H.; Lance, M.J.

    2012-01-01

    Highlights: ► Continuous thermo-chemical surface treatment used to functionalize different types of carbon fibers. ► Surface density of functional groups directly correlated to the size of the surface microstructure. ► Preferential creation of hydroxyls and carboxylic acids confirmed regardless of the type of carbon fiber. ► Effective surface treatment regardless of the fiber surface microstructure. ► Potential alternative to electro-chemical surface treatment. - Abstract: Carbon fibers made of textile and aerospace grade polyacrylonitrile precursor fibers were surface treated by a continuous gas phase thermochemical treatment. The surface chemistry generated by the surface treatment was characterized by X-ray photoelectron spectroscopy. The surface and the average entire microstructure of the fibers were characterized by Raman spectroscopy and X-ray diffraction, respectively. Depending on the grade of the precursor, the final surface concentration of oxygen was comprised between 14% and 24%, whereas the typical commercial electrochemical surface treatments led to concentrations of around 8% with the same fibers. The final concentration of oxygen was directly correlated to the size of the crystallites which was a function of the grade of the polyacrylonitrile precursor and to the corresponding surface microstructure. The thermochemical surface treatment enabled a better control of the nature of the oxygen-containing functionalities as well. Whatever the grade of the precursor, desired hydroxyl groups and carboxylic acid functionalities were preferably generated, which is observed to be difficult with electrochemical surface treatments.

  10. Comparison surface characteristics and chemical composition of conventional metallic and Nickel-Free brackets

    Directory of Open Access Journals (Sweden)

    Ricardo Lima SHINTCOVSK

    2015-01-01

    Full Text Available This study aims at comparing conventional and nickel-free metal bracket surface characteristics with elemental composition by scanning electron microscopy (SEM, using energy dispersive spectroscopy (EDS. The sample consisted of 40 lower incisor brackets divided into four groups: ABZ = conventional brackets, Kirium Abzil 3M® (n = 10; RL = conventional brackets, Roth Light Morelli® (n = 10; NF = nickel-free brackets, Nickel-Free Morelli® (n = 10; and RM = nickel-free brackets, Roth Max Morelli® (n = 10. Qualitative evaluation of the bracket surface was performed using SEM, whereby surface features were described and compared. The elemental composition was analyzed by EDS. According to surface analysis,groups ABZ and RL showed a homogeneous surface, with better finishing, whereas the surfaces in groups NF and RM were rougher. The chemical components with the highest percentage were Fe, Cr and C. Groups NF and MR showed no nickel in their composition. In conclusion, the bracket surface of the ABZ and RL groups was more homogeneous, with grooves and pores, whereas the surfaces in groups NF and RM showed numerous flaws, cracks, pores and grooves. The chemical composition analysis confirmed that the nickel-free brackets had no Ni in their composition, as confirmed by the manufacturer’s specifications, and were therefore safe to use in patients with a medical history of allergy to this metal.

  11. Effects of Near Soil Surface Characteristics on the Soil Detachment Process in a Chronological Series of Vegetation Restoration

    Science.gov (United States)

    Wang, Bing

    2017-04-01

    The effects of near soil surface characteristics on the soil detachment process might be different at different stages of vegetation restoration. This study was performed to investigate the effects of the near soil surface factors of plant litter, biological soil crusts (BSCs), dead roots and live roots on the soil detachment process by overland flow at different stages of restoration. Soil samples (1 m long, 0.1 m wide, and 0.05 m high) under four treatment conditions were collected from 1-yr-old and 24-yr-old natural grasslands and subjected to flow scouring under five different shear stresses ranging from 5.3 to 14.6 Pa. The results indicated that the effects of near soil surface characteristics on soil detachment were substantial during the process of vegetation restoration. The total reduction in the soil detachment capacity of the 1-yr-old grassland was 98.1%, and of this total, 7.9%, 30.0% and 60.2% was attributed to the litter, BSCs and plant roots, respectively. In the 24-yr-old grassland, the soil detachment capacity decreased by 99.0%, of which 13.2%, 23.5% and 62.3% was caused by the litter, BSCs and plant roots, respectively. Combined with the previously published data of a 7-yr-old grassland, the influence of plant litter on soil detachment was demonstrated to increase with restoration time, but soil detachment was also affected by the litter type and composition. The role of BSCs was greater than that of plant litter in reducing soil detachment during the early stages of vegetation recovery. However, its contribution weakened with time since restoration. The influence of plant roots accounted for at least half or up to two-thirds of the total near soil surface factors, of which more than 72.6% was attributed to the physical binding effects of the roots. The chemical bonding effect of the roots increased with time since restoration and was greater than the effect of the litter on soil detachment in the late stages of vegetation restoration. The

  12. Influence of multi-wavelength laser irradiation of enamel and dentin surfaces on surface morphology and permeability

    Science.gov (United States)

    Chang, Nai-Yuan N.; Jew, Jamison; Simon, Jacob C.; Chan, Kenneth H.; Lee, Robert C.; Fried, William A.; Cho, Jinny; Darling, Cynthia L.; Fried, Daniel

    2017-02-01

    UV and IR lasers can be used to specifically target protein, water, and the mineral phase of dental hard tissues to produce varying changes in surface morphology. In this study, we irradiated enamel and dentin surfaces with various combinations of lasers operating at 0.355, 2.94, and 9.4 μm, exposed those surfaces to topical fluoride, and subsequently evaluated the influence of these changes on surface morphology and permeability. Digital microscopy and surface dehydration rate measurements were used to monitor changes in the samples overtime. The surface morphology and permeability (dehydration rate) varied markedly with the different laser treatments on enamel. On dentin, fluoride was most effective in reducing the permeability.

  13. Influence of water on the surface of graphene

    Directory of Open Access Journals (Sweden)

    Kaya Yunus

    2018-01-01

    Full Text Available We have studied how water modifies the surface of graphene and in particular how the surface conductivity of graphene is affected. According to the literature, two types of interactions should be distinguished: physical, where a water molecule remains intact and is located at some distance from the mesh, and chemical, where a water molecule is imbricated in the graphene bond structure. We have developed theoretical models for both types of interactions using the density functional theory (DFT with the B3LYP hybrid functional combined with the 6-31G(d basis set. Our calculations show that the surface conductivity of graphene is reduced in the presence of water.

  14. Investigation of electrical characteristics of no-insulation coil wound with surface-processed HTS tape

    Science.gov (United States)

    Jeon, Haeryong; Lee, Woo Seung; Kim, Jinsub; Baek, Geonwoo; Jeon, Sangsu; Yoon, Yong Soo; Ko, Tae Kuk

    2017-08-01

    This paper deals with the electrical characteristics of no-insulation coil wound with surface-processed HTS tape. The bypassing current path through turn-to-turn contacts within a coil is formed in the no-insulation coil, and this bypassing current path determines two characteristics: 1) self-protection and 2) charge-discharge delay. The amplitude of bypassing current is determined by contact resistance between the turn-to-turn contacts of the no-insulation coil. The surface roughness of the HTS tape is one of the parameters to change the contact resistance. The HTS tapes were processed to roughen by bead blast and abrasive paper, and the no-insulation coil is fabricated using processed HTS tape. We have studied the charge-discharge delay and self-protecting characteristic of each no-insulation coil by 1) sudden discharge tests and 2) overcurrent tests. The FEM simulations of contact resistance of no-insulation coil were carried out. The contact surface resistance of a case processed by abrasive paper has almost three times larger than that of reference no-insulation coil, and a case processed by bead blast presents almost same contact surface resistance with reference no-insulation coil.

  15. Influence of polishing on surface roughness following toothbrushing wear of composite resins.

    Science.gov (United States)

    Dalla-Vecchia, Karine Battestin; Taborda, Talita Damas; Stona, Deborah; Pressi, Heloísa; Burnett Júnior, Luiz Henrique; Rodrigues-Junior, Sinval Adalberto

    2017-01-01

    This study aimed to evaluate the influence of different polishing systems on the surface roughness of composite resins following procedures to simulate the effects of toothbrushing over time. Four currently available commercial composites were used to make 128 cylindrical specimens. The specimens were randomly allocated to polishing with a 1-step polisher or 1 of 3 multistep polishers (n = 8 per group). The baseline surface roughness was measured, and the specimens were submitted to 5000, 10,000, and 20,000 brushing cycles to represent toothbrushing throughout 6, 12, and 24 months, respectively. Results showed that surface roughness was influenced by the type of composite and polishing system and was not influenced by the simulated toothbrushing time. However, the surface roughness, as challenged by toothbrushing wear, was affected by the interaction among the composite, the polisher, and the toothbrushing time. The 1-step polisher produced the highest surface roughness and influenced toothbrushing wear resistance of some composites.

  16. Cultural Influences on Hepatitis B Surface Antigen Seropositivity in ...

    African Journals Online (AJOL)

    Objective: To determine the role of cultural influences, namely: circumcision, ear piercing and traditional scarification, on HbsAg seropositivity among primary school children in Nnewi. Subjects and Method: Two hundred and thirty seven randomly selected primary school children aged 5-12 years, were screened for HbsAg.

  17. Influence of discharged effluent on the quality of surface water ...

    African Journals Online (AJOL)

    ... higher values of determinants obtained from sampling points close to the wastewater treatment plant and the mine exit channels strongly revealed their influence on the general quality of the stream. Detection of metals such as cadmium and lead above acceptable limits has dire consequences across the food chain.

  18. Numerical modeling of the effects of a free surface on the operating characteristics of Marine Hydrokinetic Turbines

    Science.gov (United States)

    Adamski, Samantha; Aliseda, Alberto

    2012-11-01

    Marine Hydrokinetic (MHK) turbines are a growing area of research in the renewable energy field because tidal currents are a highly predictable clean energy source. The presence of a free surface may influence the flow around the turbine and in the wake, critically affecting turbine performance and environmental effects through modification of wake physical variables. The characteristic Froude number that control these processes is still a matter of controversy, with the channel depth and turbine's depth, blade tip depth and diameter as potential candidates for a length scale used in literature. We use the Volume of Fluid model to track the free surface dynamics in a RANS simulation with a BEMT model of the turbine to understand the physics of the wake-free surface interactions. Pressure and flow rate boundary conditions for channel's inlet, outlet and air side have been tested in an effort to determine the optimum set of simulation conditions for MHK turbines in rivers or estuaries. Stability and accuracy in terms of power extraction and kinetic and potential energy budgets are considered. The goal of this research is to determine, quantitatively in non dimensional parameter space, the limit between negligible and significant free surface effects on MHK turbine analysis. Supported by DOE through the National Northwest Marine Renewable Energy Center.

  19. The inaccuracy of heat transfer characteristics for non-insulated and insulated spherical containers neglecting the influence of heat radiation

    International Nuclear Information System (INIS)

    Wong, King-Leung; Salazar, Jose Luis Leon; Prasad, Leo; Chen, Wen-Lih

    2011-01-01

    In this investigation, the differences of heat transfer characteristics for insulated and non-insulated spherical containers between considering and neglecting the influence of heat radiation are studied by the simulations in some practical situations. It is found that the heat radiation effect cannot be ignored in conditions of low ambient convection heat coefficients (such ambient air) and high surface emissivities, especially for the non-insulated and thin insulated cases. In most practical situations when ambient temperature is different from surroundings temperature and the emissivity of insulation surface is different from that of metal wall surface, neglecting heat radiation will result in inaccurate insulation effect and heat transfer errors even with very thick insulation. However, the insulation effect considering heat radiation will only increase a very small amount after some dimensionless insulated thickness (such insulation thickness/radius ≥0.2 in this study), thus such dimensionless insulated thickness can be used as the optimum thickness in practical applications. Meanwhile, wrapping a material with low surface emissivity (such as aluminum foil) around the oxidized metal wall or insulation layer (always with high surface emissivity) can achieve very good insulated effect for the non-insulated or thin insulated containers.

  20. Influence of limestone fillers on combustion characteristics of asphalt mortar for pavements

    DEFF Research Database (Denmark)

    Ke, Wu; Kai, Zhu; Wu, Hao

    2014-01-01

    Asphalt materials will be ignited and release significant toxic fumes within tunnel fires. Thus, combustion characteristics of asphalt materials used in road tunnel should be studied in order to limit such an adverse effect. In the present work we study the influence of limestone fillers on combu...

  1. Influence of various manufacturing parameters on some characteristics of UO2 powders and their sintering behaviour

    International Nuclear Information System (INIS)

    Mintz, M.H.; Vaknin, Sh.; Kremener, A.; Hadari, Z.

    1977-02-01

    Various parameters in the process of manufacturing uranium dioxide are examined and their influence on the characteristics and sintering behaviour of the powders obtained established. In addition some correlations between the powder aggregates microstructure and their adhesion properties and sintering behaviour are indicated. Shrinkage during the sintering process is also discussed

  2. Bran characteristics influencing quality attributes of whole wheat Chinese steamed bread

    Science.gov (United States)

    This study investigated the variations in the characteristics of brans obtained from a pilot-scale milling of 17 soft red winter wheat varieties and their influences on the quality of whole wheat northern-style Chinese steamed bread (CSB) prepared from blends of a base flour and brans of different w...

  3. Sediment deposition from forest roads at stream crossings as influenced by road characteristics

    Science.gov (United States)

    A.J. Lang; W.M. Aust; M.C. Bolding; K.J. McGuire

    2015-01-01

    Recent controversies associated with ditched forest roads and stream crossings in the Pacific Northwest have focused national attention on sediment production and best management practices (BMPs) at stream crossings. Few studies have quantified soil erosion rates at stream crossings as influenced by road characteristics and compared them to modeled rates. Soil erosion...

  4. Biomarkers of asbestos-induced lung injury: the influence of fiber characteristics and exposure methodology

    Science.gov (United States)

    ATS 2013 Biomarkers of asbestos-induced lung injury: the influence of fiber characteristics and exposure methodology Urmila P Kodavanti, Debora Andrews, Mette C Schaldweiler, Jaime M Cyphert, Darol E Dodd, and Stephen H Gavett NHEERL, U.S. EPA, Research Triangle Park, NC; NIEH...

  5. Do general practice characteristics influence uptake of an information technology (IT innovation in primary care?

    Directory of Open Access Journals (Sweden)

    Josie Evans

    2008-05-01

    Conclusions The analyses show that structural characteristics of a practice are not associated with uptake of a new IT facility, but that its use may be influenced by post-graduate education in the relevant clinical condition. For this diabetes system at least, practice nurse use was critical in spreading uptake beyond initial GP enthusiasts and for sustained and rising use in subsequent years.

  6. The influence of series resistance on the I-V characteristics of CdTe ...

    African Journals Online (AJOL)

    The influence of series resistance (Rs) on the current (I) – voltage(V) characteristics of evaporated cadmium telluride(CdTe) thin films has been investigated. CdTe films of thickness 1000Å were deposited by thermal evaporation in a vacuum of about 10-5torr. For the I – V measurements, the two point probe configuration ...

  7. Characterization of surface dielectric barrier discharge influenced by intermediate frequency for ozone production

    International Nuclear Information System (INIS)

    Abdelaziz, Ayman A; Ishijima, Tatsuo; Seto, Takafumi; Otani, Yoshio; Osawa, Naoki; Wedaa, Hassan

    2016-01-01

    The aim of this study is to investigate the effect of the intermediate frequency (1–10 kHz) of the sinusoidal driving voltage on the characteristics of a developed surface dielectric barrier discharge (SDBD)-based reactor having spikes on its discharge electrode. Moreover, its influence on the production of ozone and nitrogen oxide byproducts is evaluated. The results show that SDBD is operated in the filamentary mode at all the frequencies. Nevertheless, the pulses of the discharge current at high frequencies are much denser and have higher amplitudes than those at low frequencies. The analysis of the power consumed in the reactor shows that a small portion of the input power is dissipated in the dielectric material of SDBD source, whereas the major part of the power is consumed in the plasma discharge. The results of the ozone production show that higher frequencies have a slightly adverse effect on the ozone production at relatively high energy density values, where the ozone concentration is slightly decreased when the frequency is increased at the same energy density. The temperature of the discharge channels and gas is not a crucial factor for the decomposition of ozone in this reactor, while the results of the measurements of nitrogen oxides characteristics indicate that the formation of NO and NO 2 has a significant adverse effect on the production efficiency of ozone due to their oxidation to another nitrogen oxides and their catalytic effect. (paper)

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

    Science.gov (United States)

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

  9. Influence of argon plasma treatment on polyethersulphone surface

    Indian Academy of Sciences (India)

    2013-01-09

    Jan 9, 2013 ... waste water treatment from heavy and toxic metals, low-level nuclear waste management and separation of Zr from uranium in their wastes and enzyme immobilization. The aim of this work is to improve superficial hydrophilic properties of PES films by measuring contact angle (surface free energy, SFE), ...

  10. Influence of Ear Surface Area on Heat Tolerance of Composite ...

    African Journals Online (AJOL)

    Low correlation (r = 0.12) was observed between body weight and ear width. There were no correlations between ear width, respiratory rates and pulse rate. However, a residual correlation (r = -0.03) was obtained between ear width and body temperature. Large ear surface area in composite rabbits enhances better ...

  11. An Investigation of Ice Surface Albedo and Its Influence on the High-Altitude Lakes of the Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Jiahe Lang

    2018-02-01

    Full Text Available Most high-altitude lakes are more sensitive to global warming than the regional atmosphere. However, most existing climate models produce unrealistic surface temperatures on the Tibetan Plateau (TP lakes, and few studies have focused on the influence of ice surface albedo on high-altitude lakes. Based on field albedo measurements, moderate resolution imaging spectrometer (MODIS albedo products and numerical simulation, this study evaluates the ice albedo parameterization schemes in existing lake models and investigates the characteristics of the ice surface albedo in six typical TP lakes, as well as the influence of ice albedo error in the FLake model. Compared with observations, several ice albedo schemes all clearly overestimate the lake ice albedo by 0.26 to 0.66, while the average bias of MODIS albedo products is only 0.07. The MODIS-observed albedo of a snow-covered lake varies with the snow proportion, and the lake surface albedo in a snow-free state is approximately 0.15 during the frozen period. The MODIS-observed ice surface (snow-free albedos are concentrated within the ranges of 0.14–0.16, 0.08–0.10 and 0.10–0.12 in Aksai Chin Lake, Nam Co Lake and Ngoring Lake, respectively. The simulated lake surface temperature is sensitive to variations in lake ice albedo especially in the spring and winter.

  12. Influence of surface roughness of stainless steel on microbial adhesion and corrosion resistance

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel; Bagge-Ravn, Dorthe; Kold, John

    2003-01-01

    was evaluated in a commercial disinfectant and in 1 M NaCl. Electropolished and grit 4000 polished steel proved more corrosion resistant as opposed to grit 80 and 120 polished surfaces. In conclusion, the surface finish did not influence bacterial attachment, colonisation, or removal, but is an important...... was not affected by surface roughness (Ra) ranging from grit 4000 polished stainless steel (Ra resistance...... parameter for the corrosion resistance of the surface....

  13. Significant improvement in the electrical characteristics of Schottky barrier diodes on molecularly modified Gallium Nitride surfaces

    Science.gov (United States)

    Garg, Manjari; Naik, Tejas R.; Pathak, C. S.; Nagarajan, S.; Rao, V. Ramgopal; Singh, R.

    2018-04-01

    III-Nitride semiconductors face the issue of localized surface states, which causes fermi level pinning and large leakage current at the metal semiconductor interface, thereby degrading the device performance. In this work, we have demonstrated the use of a Self-Assembled Monolayer (SAM) of organic molecules to improve the electrical characteristics of Schottky barrier diodes (SBDs) on n-type Gallium Nitride (n-GaN) epitaxial films. The electrical characteristics of diodes were improved by adsorption of SAM of hydroxyl-phenyl metallated porphyrin organic molecules (Zn-TPPOH) onto the surface of n-GaN. SAM-semiconductor bonding via native oxide on the n-GaN surface was confirmed using X-ray photoelectron spectroscopy measurements. Surface morphology and surface electronic properties were characterized using atomic force microscopy and Kelvin probe force microscopy. Current-voltage characteristics of different metal (Cu, Ni) SBDs on bare n-GaN were compared with those of Cu/Zn-TPPOH/n-GaN and Ni/Zn-TPPOH/n-GaN SBDs. It was found that due to the molecular monolayer, the surface potential of n-GaN was decreased by ˜350 mV. This caused an increase in the Schottky barrier height of Cu and Ni SBDs from 1.13 eV to 1.38 eV and 1.07 eV to 1.22 eV, respectively. In addition to this, the reverse bias leakage current was reduced by 3-4 orders of magnitude for both Cu and Ni SBDs. Such a significant improvement in the electrical performance of the diodes can be very useful for better device functioning.

  14. Influence of the surface roughness of coated and uncoated papers on the digital print mottle

    Directory of Open Access Journals (Sweden)

    Ivana Jurič

    2014-07-01

    Full Text Available Many factors influence the occurrence of print mottle in prints. In printing process three main components are involved: printing press, substrate and toner. They can be considered as separate components, but in most cases their interaction influences the quality of the print. The goal of this work was to examine the influence of surface roughness of different types of paper (coated and uncoated on print mottle of electrophotographic digital prints. We set up a hypothesis that print mottle will be more apparent on rougher surfaces. In the experimental part we printed four different substrates with different surface properties on electrophotographic printing press. Morphology of the papers surface was analysed using atomic force microscopy (AFM from which surface properties were calculated. For print mottle characterization Gray level co-occurrence matrix (GLCM method was used. Based on the measurements and results we can conclude, contrary to the initial hypothesis, that uncoated papers with rougher surfaces produce smaller print mottle values.

  15. The influences of soil and nearby structures on dispersion characteristics of wave propagating along buried plastic pipes

    Science.gov (United States)

    Liu, Shuyong; Jiang, J.; Parr, Nicola

    2016-09-01

    Water loss in distribution systems is a global problem for the water industry and governments. According to the international water supply association (IWSA), as a result of leaks from distribution pipes, 20% to 30% of water is lost while in transit from treatment plants to consumers. Although governments have tried to push the water industry to reduce the water leaks, a lot of experts have pointed out that a wide use of plastic pipes instead of metal pipes in recent years has caused difficulties in the detection of leaks using current acoustic technology. Leaks from plastic pipes are much quieter than traditional metal pipes and comparing to metal pipes the plastic pipes have very different coupling characteristics with soil, water and surrounding structures, such as other pipes, road surface and building foundations. The dispersion characteristics of wave propagating along buried plastic pipes are investigated in this paper using finite element and boundary element based models. Both empty and water- filled pipes were considered. Influences from nearby pipes and building foundations were carefully studied. The results showed that soil condition and nearby structures have significant influences on the dispersion characteristics of wave propagating along buried plastic pipes.

  16. The effects of liquid-phase oxidation of multiwall carbon nanotubes on their surface characteristics

    Science.gov (United States)

    Burmistrov, I. N.; Muratov, D. S.; Ilinykh, I. A.; Kolesnikov, E. A.; Godymchuk, A. Yu; Kuznetsov, D. V.

    2016-01-01

    The development of new sorbents based on nanostructured carbon materials recently became a perspective field of research. Main topic of current study is to investigate the effect of different regimes of multiwall carbon nanotubes (MWCNT) surface modification process on their structural characteristics. MWCNT samples were treated with nitric acid at high temperature. Structural properties were studied using low temperature nitrogen adsorption and acid-base back titration methods. The study showed that diluted nitric acid does not affect MWCNT structure. Concentrated nitric acid treatment leads to formation of 2.8 carboxylic groups per 1 nm2 of the sample surface.

  17. Research on Pin Tumbler Locks and the Characteristics of Surface Traces Formed by Unlocking Guns

    Science.gov (United States)

    Yi, Gao; Yifeng, Jin; Yanping, Bai; Hongcheng, Mei; Zhen, Xu

    2018-02-01

    In this paper, taking the structure of the pin tumbler locks and the principle of opening and closing locks as breakthrough point, we have studied the machining traces of pin tumbler components and trace characters of pin surface during normal operating. At the same time, taking the unlocking gun as an example, the paper analyzes the unlocking technology and the formation of traces, and summarizes the changing rules of the surface traces of elastic bead locks by comparing the positions and the characteristics of the traces, which provides technical support for the future study of traces of pin tumbler locks.

  18. Modifications of mechanical characteristics and iron corrosion by ionic implantation on surface

    International Nuclear Information System (INIS)

    Baumvol, I.J.

    1980-01-01

    Tin ionic implantation on pure iron surface at moderate doses (5x10 15 to 5x10 16 ) Sn + Cu -2 ) has proven to be very efficient in improving the metal characteristics to oxidation and abrasion at high temperature. The abrasion volumetric coefficient K v , is reduced from up to 100 times, and the oxidation tax constant is reduced from up to 10 times. The physical mechanisms responsible for these phenomena are studied using different techniques of surface analysis; as Rutherford backscattering of alpha particles, Moessbauer spectroscopy of conversion electrons and sweeping electronic microscopy. (A.C.A.S.) [pt

  19. Nanoscale surface modifications to control capillary flow characteristics in PMMA microfluidic devices

    Directory of Open Access Journals (Sweden)

    Mukhopadhyay Subhadeep

    2011-01-01

    Full Text Available Abstract Polymethylmethacrylate (PMMA microfluidic devices have been fabricated using a hot embossing technique to incorporate micro-pillar features on the bottom wall of the device which when combined with either a plasma treatment or the coating of a diamond-like carbon (DLC film presents a range of surface modification profiles. Experimental results presented in detail the surface modifications in the form of distinct changes in the static water contact angle across a range from 44.3 to 81.2 when compared to pristine PMMA surfaces. Additionally, capillary flow of water (dyed to aid visualization through the microfluidic devices was recorded and analyzed to provide comparison data between filling time of a microfluidic chamber and surface modification characteristics, including the effects of surface energy and surface roughness on the microfluidic flow. We have experimentally demonstrated that fluid flow and thus filling time for the microfluidic device was significantly faster for the device with surface modifications that resulted in a lower static contact angle, and also that the incorporation of micro-pillars into a fluidic device increases the filling time when compared to comparative devices.

  20. Shaft Position Influence on Technical Characteristics of Universal Two-Stages Helical Speed Reducers

    Directory of Open Access Journals (Sweden)

    Мilan Rackov

    2005-10-01

    Full Text Available Purchasers of speed reducers decide on buying those reducers, that can the most approximately satisfy their demands with much smaller costs. Amount of used material, ie. mass and dimensions of gear unit influences on gear units price. Mass and dimensions of gear unit, besides output torque, gear unit ratio and efficiency, are the most important parameters of technical characteristics of gear units and their quality. Centre distance and position of shafts have significant influence on output torque, gear unit ratio and mass of gear unit through overall dimension of gear unit housing. Thus these characteristics are dependent on each other. This paper deals with analyzing of centre distance and shaft position influence on output torque and ratio of universal two stages gear units.

  1. Nanometer polymer surface features: the influence on surface energy, protein adsorption and endothelial cell adhesion

    Science.gov (United States)

    Carpenter, Joseph; Khang, Dongwoo; Webster, Thomas J.

    2008-12-01

    Current small diameter (lactic-co-glycolic acid) (PLGA) surfaces elevated endothelial cell adhesion, proliferation, and extracellular matrix synthesis when compared to nanosmooth surfaces. Nonetheless, these studies failed to address the importance of lateral and vertical surface feature dimensionality coupled with surface free energy; nor did such studies elicit an optimum specific surface feature size for promoting endothelial cell adhesion. In this study, a series of highly ordered nanometer to submicron structured PLGA surfaces of identical chemistry were created using a technique employing polystyrene nanobeads and poly(dimethylsiloxane) (PDMS) molds. Results demonstrated increased endothelial cell adhesion on PLGA surfaces with vertical surface features of size less than 18.87 nm but greater than 0 nm due to increased surface energy and subsequently protein (fibronectin and collagen type IV) adsorption. Furthermore, this study provided evidence that the vertical dimension of nanometer surface features, rather than the lateral dimension, is largely responsible for these increases. In this manner, this study provides key design parameters that may promote vascular graft efficacy.

  2. Surface characteristics of hydroxyapatite films deposited on anodized titanium by an electrochemical method

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kang [Research Institute, Kuwotech, 970–88, Wolchul-dong, Buk-ku, Gwangju (Korea, Republic of); Department of Dental Materials and Research Center of Nano-Interface Activation for Biomaterials, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Jeong, Yong-Hoon; Brantley, William A. [Division of Restorative, Prosthetic and Primary Care Dentistry, College of Dentistry, The Ohio State, University, Columbus, OH (United States); Choe, Han-Cheol, E-mail: hcchoe@chosun.ac.kr [Department of Dental Materials and Research Center of Nano-Interface Activation for Biomaterials, School of Dentistry, Chosun University, Gwangju (Korea, Republic of)

    2013-11-01

    The biocompatibility of anodized titanium (Ti) was improved by an electrochemically deposited calcium phosphate (CaP) layer. The CaP layer was grown on the anodized Ti surface in modified simulated body fluid (M-SBF) at 85 °C. The phases and morphologies for the CaP layers were influenced by the electrolyte concentration. Nano flake-like precipitates that formed under low M-SBF concentrations were identified as hydroxyapatite (HAp) crystals orientated in the c-axis direction. In high M-SBF concentrations, the CaP layer formed micro plate-like precipitates on anodized Ti, and micropores were covered with HAp. Proliferation of murine preosteoblast cell (MC3T3-E1) on the HAp/anodized Ti surfaces was significantly higher than for untreated Ti and anodized Ti surfaces. - Highlights: • CaP layers were grown on anodized Ti surfaces by an electrochemical deposition process. • Phases and morphologies of layers were influenced by the electrolyte concentration. • Superior cell proliferation was observed on hydroxyapatite-coated anodized surfaces.

  3. Gait Characteristics Associated with Trip-Induced Falls on Level and Sloped Irregular Surfaces

    Directory of Open Access Journals (Sweden)

    Andrew Merryweather

    2011-11-01

    Full Text Available Same level falls continue to contribute to an alarming number of slip/trip/fall injuries in the mining workforce. The objective of this study was to investigate how walking on different surface types and transverse slopes influences gait parameters that may be associated with a trip event. Gait analysis was performed for ten subjects on two orientations (level and sloped on smooth, hard surface (control and irregular (gravel, larger rocks surfaces. Walking on irregular surfaces significantly increased toe clearance compared to walking on the smooth surface. There was a significant (p < 0.05 decrease in cadence (steps/min, stride length (m, and speed (m/s from control to gravel to larger rocks. Significant changes in external rotation and increased knee flexion while walking on irregular surfaces were observed. Toe and heel clearance requirements increased on irregular surfaces, which may provide an explanation for trip-induced falls; however, the gait alterations observed in the experienced workers used as subjects would likely improve stability and recovery from a trip.

  4. Influence of surface roughness skewness on rolling contact fatigue life

    Science.gov (United States)

    Akamatsu, Yoshinobu; Tsushima, Noriyuki; Goto, Toshihide; Hibi, Kenji

    1992-10-01

    This paper evaluates the effects of randomly distributed small indentations, or pits, on the lubricating properties when operating under these mixed or boundary lubrication conditions. Rings and needle rollers were textured with randomly distributed small indentations, or pits, for evaluation. Skewness (Sk) was used as a measure of surface finish to characterize the degree to which the material of these modified parts was above the mean line, a positive value, or below the mean line, a negative value. Fatigue life tests were conducted on these rolling elements, whose skewness ranged from -1.2 to -2.0, under mixed or boundary lubrication conditions. Test results showed rolling bearing fatigue life to increase with a decrease in skewness as related to the depth, width, and distribution of the surface indentations, or pits, on the parts.

  5. Investigating the influence of effective parameters on molecular characteristics of bovine serum albumin nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Rohiwal, S.S.; Satvekar, R.K.; Tiwari, A.P.; Raut, A.V.; Kumbhar, S.G.; Pawar, S.H., E-mail: pawar_s_h@yahoo.com

    2015-04-15

    Graphical abstract: The physiochemical properties of nanoparticles provide the basic aspects about the conformational transitions which could have a strong bearing on the bioavailability for bioactive molecules such as peptides and hormones. - Highlights: • Synthesis and surface and structural properties of Bovine Serum Albumin nanoparticles (BSANPs). • Study of conformational transitions of BSANPs by spectroscopic techniques. • Studies on the effect of pH and protein concentration on formulation of BSANPs. - Abstract: The protein nanoparticles formulation is a challenging task as they are prone to undergo conformational transitions while processing which may affect bioavailability for bioactive compounds. Herein, a modified desolvation method is employed to prepare Bovine Serum Albumin nanoparticles, with controllable particle size ranging from 100 to 300 nm and low polydispersity index. The factors influencing the size and structure of BSA NPs viz. protein concentration, pH and the conditions for purification are well investigated. The structure of BSA NPs is altered due to processing, and may affect the effective binding ability with drugs and bioactive compounds. With that aims, investigations of molecular characteristics of BSA NPs are carried out in detail by using spectroscopic techniques. UV–visible absorption and Fourier Transform Infrared demonstrate the alteration in protein structure of BSA NPs whereas the FT-Raman spectroscopy investigates changes in the secondary and tertiary structures of the protein. The conformational changes of BSA NPs are observed by change in fluorescence intensity and emission maximum wavelength of tryptophan residue by fluorescence spectroscopy. The field emission scanning electron and atomic force microscopy micrographs confirm the size and semi-spherical morphology of the BSA NPs. The effect of concentration and pH on particle size distribution is studied by particle size analyzer.

  6. Influence of geometrical parameters on turbulent flow and heat transfer characteristics in outward helically corrugated tubes

    International Nuclear Information System (INIS)

    Wang, Wei; Zhang, Yaning; Li, Bingxi; Han, Huaizhi; Gao, Xiaoyan

    2017-01-01

    Highlights: • The outward helically corrugated tube is suitable for high pressure fluids. • The effects of corrugation height and pitch on turbulent flow are investigated. • The relationships among swirl, rotational flow and heat transfer are discussed. - Abstract: Concerning a novel outward helically corrugated tube manufactured through hydraulic forming under 290 MPa, a numerical study was conducted to investigate the mechanism of turbulent flow dynamics and heat transfer enhancement based on the Reynolds stress model (RSM) using the FLUENT software. A validation of the Reynolds stress model for turbulent flow over a wavy surface was performed, and the results were then compared with the results from a large eddy simulation (LES) model and with experimental measurements. The helically corrugated tubes with different corrugation height-to-diameter ratios and pitch-to-diameter ratios are then evaluated to explore their influence on turbulent flow and heat transfer. It was found that the intensity of swirl flow was enhanced with an increase in the corrugation height, and it increased with a decrease in the corrugation pitch, the intensification of the swirl flow strengthens the heat transfer and resistance characteristics. The intensity of rotational flow was enhanced with an increase in the corrugation height, and increased with an increase in the corrugation pitch; the enhanced rotational flow causes an inhibition effect on heat transfer and resistance. Moreover, the maximum values of the local Nusselt number and the friction factor along the walls were observed at the reattachment point, and their minimum values appeared at the core of the swirl flow. It is therefore reasonable to keep the corrugation height-to-diameter ratios be less than 0.1, and the pitch-to-diameter ratios be less than 2 to ensure that the growth rate of the heat transfer is greater than the growth rate of the flow resistance.

  7. Surface Analytical Techniques for Microbiologically Influenced Corrosion. A Review

    Science.gov (United States)

    1994-01-01

    natural waters and colonize surfaces to produce biofilms. The biofilms are varied in composition but usually include bacteria, algae, and fungi, in...potential and dissolved oxgen oicitlauios associated ivith ate Anain, sp.ference andd tentation l biofili ptiuder a 61h light/dark regime. Ligtht ...depositing bacteria. and (c) crosssco thilrough pie 1%ed %en natural waters! has re Ited i areas conducive t acteri: should be known TING WAGNER AND RAY ON

  8. Study on team characteristics influencing on nuclear safety culture in Korea based on Bayesian networks

    International Nuclear Information System (INIS)

    Young-gab, K.; Chan-ho, S.; Jeong-jin, P.

    2014-01-01

    The safety culture of Korean nuclear power plants has been settled down as an organizational culture since the Chernobyl accident in 1986. Reason (1997) proposed that safety culture is a sub-culture of corporate culture and sub-culture is a term that can be used interchangeably to a sub-group of people (i.e., department, workgroup). Therefore, the safety culture of organization comprised of various teams can be told as a culture to reflect team characteristics and interact with each other. Team characteristics have something to do with a successful task performance and task efficiency. However, the team characteristics in nuclear power plant have to consider safety preferentially rather than performance. Team characteristics for a safety are necessary to ensure and enhance the safety of safety-critical system. This paper proposed team characteristics for a safety which influence on the strong and vulnerable area of safety culture. These characteristics were analyzed on the basis of the safety culture evaluation which was performed to measure the level of plant workers' safety culture in 2013. The model of team characteristics was constructed considering Bayesian inference and the result was proposed according to workers' awareness. Safety team characteristics have a direct or indirect effect on the safety of nuclear power plants. Therefore, if they are improved and trained continuously, the safety of nuclear power plants might be enhanced. (author)

  9. Processes setting the characteristics of sea surface cooling induced by tropical cyclones

    OpenAIRE

    Vincent, E.M.; Lengaigne, Matthieu; Madec, G.; Vialard, Jérôme; Samson, G.; Jourdain, N.C.; Menkès, Christophe; Jullien, S.

    2012-01-01

    A 1/2 degrees resolution global ocean general circulation model is used to investigate the processes controlling sea surface cooling in the wake of tropical cyclones (TCs). Wind forcing related to more than 3000 TCs occurring during the 1978-2007 period is blended with the CORE II interannual forcing, using an idealized TC wind pattern with observed magnitude and track. The amplitude and spatial characteristics of the TC-induced cooling are consistent with satellite observations, with an aver...

  10. Coupling characteristics of dielectric-loaded surface plasmon polariton waveguides: a simple method of analysis.

    Science.gov (United States)

    Srivastava, Triranjita; Kumar, Arun

    2009-11-01

    A simple method to obtain the coupling characteristics of a directional coupler consisting of two dielectric-loaded surface plasmon polariton waveguides is reported. The method is found to give accurate results in comparison with the widely used effective index method. Theoretical results are also found to match excellently with recently reported measurements on coupling lengths in such waveguides [Opt. Lett.34, 310 (2009)OPLEDP0146-959210.1364/OL.34.000310].

  11. [Effects of surface roughness of bone cements on histological characteristics of induced membranes].

    Science.gov (United States)

    Liu, Hai-Xiao; Xu, Hua-Zi; Zhang, Yu; Hu, Gang; Shen, Yue; Cheng, Xiao-Jie; Peng, Lei

    2012-08-01

    To explore surface roughness of bone cement and surround tissue on histological characteristic of induced membranes. Bone cements with smooth and rough surface were implanted in radius bone defect, intramuscular and subcutaneous sites of rabbits, and formed induced membranes. Membranes were obtained and stained (HE) 6 weeks later. Images of membrane tissue were obtained and analyzed with an automated image analysis system. Five histological parameters of membranes were measured with thickness,area,cell density,ECM density and microvessel density. Double factor variance analysis was used to evaluate the effect of the two factors on histological characteristics of induced membranes. Membranes can be induced by each kind of bone cement and at all the three tissue sites. In histological parameters of thickness,area and micro vessel,there were significant differences among the membranes induced at different tissue sites (P = 0.000, P = 0.000, P = 0.000); whereas, there were no significant differences in histological parameters of cell density and ECM density (P = 0.734, P = 0.638). In all five histological parameters of membranes, there were no significant differences between the membranes induced by bone cements with different surface roughness (P = 0.506, P = 0.185, P = 0.883, P = 0.093, P = 0.918). Surround tissue rather than surface roughness of bone cements can affect the histological characteristics of induced membranes. The fibrocystic number, vascularity, mechanical tension and micro motion of the surround tissue may be closely correlated with the histological characteristics of induced membranes.

  12. Research into action of surface soil moistening, drying or freezing on electrical characteristics of grounding device

    Directory of Open Access Journals (Sweden)

    I.V. Nizhevskiy

    2014-03-01

    Full Text Available The analysis made has shown expediency of modernization rather than reconstruction of earth electrodes, after inspection of long operating substations grounding grids, via building a two-level structure. It will result in both technical and economic effects. The novelty of the results consists in studying, by means of a mathematical model, electrical characteristics of a two-level earth electrode versus the depth of surface soil drying or freezing.

  13. How characteristic routines of clinical departments influence students' self-regulated learning: A grounded theory study.

    Science.gov (United States)

    Berkhout, J J; Slootweg, I A; Helmich, E; Teunissen, P W; van der Vleuten, C P M; Jaarsma, A D C

    2017-11-01

    In clerkships, students are expected to self-regulate their learning. How clinical departments and their routine approach on clerkships influences students' self-regulated learning (SRL) is unknown. This study explores how characteristic routines of clinical departments influence medical students' SRL. Six focus groups including 39 purposively sampled participants from one Dutch university were organized to study how characteristic routines of clinical departments influenced medical students' SRL from a constructivist paradigm, using grounded theory methodology. The focus groups were audio recorded, transcribed verbatim and were analyzed iteratively using constant comparison and open, axial and interpretive coding. Students described that clinical departments influenced their SRL through routines which affected the professional relationships they could engage in and affected their perception of a department's invested effort in them. Students' SRL in a clerkship can be supported by enabling them to engage others in their SRL and by having them feel that effort is invested in their learning. Our study gives a practical insight in how clinical departments influenced students' SRL. Clinical departments can affect students' motivation to engage in SRL, influence the variety of SRL strategies that students can use and how meaningful students perceive their SRL experiences to be.

  14. Hydrochemical characteristic of surface and groundwater Lisichansk and Almazno-Marevske geological and industrial districts Nnorth-Eastern Donbas

    Directory of Open Access Journals (Sweden)

    Udalov Y.V.

    2014-12-01

    Full Text Available Incorporates a complex of problems accompanying the operation of coal deposits of Donbass. See hydrochemical characteristics of surface and groundwater Lisichansk and Almazno-Maryevskogo geological and industrial areas of the North-Eastern Donbass. Identified the main hydrochemical features of the waste mine waters of the enterprises of the coal industry on the territory of the studies. It is established that the surface waters of the study area exposed to intensive anthropogenic influence. Set content of basic elements-pollutants in surface waters. It is revealed that this pollution is of a complex nature. Identifies key elements contained in the effluent of industrial enterprises. Analyzed that a change of the chemical composition of groundwater has led to increased hardness and mineralization of water in the main water intakes of the research area. Identifies key elements-contaminants in groundwater. It was found that as a result of mine dewatering groundwater level fell over an area of 200km2, far exceeding the area of coal mining. This operational reserves fresh underground waters in the groundwater runoff module 1.2 dm3 / sec. km2 decreased by 200 - 300 m3 / day. Within funnel depression hydraulic connection is created not only a few confined aquifers, but also located near the mine fields. For example, in the area of Stakhanov the Luhansk region in general depression funnel width of about 25 km and a depth of 600-800m were 8 mine ("Central Irmino", "Maximovska" Ilyich, named after I.V. Chesnokov, "Krivoy Rog", 11-RAD "Brjankovsky" and "Dzerzhinsk". The purpose of research is general hydrochemical characteristics and identification of key elements polluting surface and groundwater Lisichanskiy and diamond-Marevskogo geological and industrial areas of the North-East Donbas.

  15. Effect of Material Composition on Cohesion Characteristics of Styrene-Butadiene-Styrene-Modified Asphalt Using Surface Free Energy

    Directory of Open Access Journals (Sweden)

    Xing-jun Zhang

    2017-01-01

    Full Text Available Styrene-butadiene-styrene- (SBS- modified asphalts were prepared by mixing different base asphalts, SBS modifier, extracting oil, and stabilizing agents. The contact angles between SBS-modified asphalt and distilled water, glycerol, and formamide were detected by the sessile drop method. Based on the surface energy theory, the surface free energy and cohesive power of SBS-modified asphalt were calculated. The influence of the raw materials composition, such as the virgin asphalt and SBS modifier types as well as the extracting oil and stabilizing agent contents, on the cohesive characteristics of SBS-modified asphalt was discussed. The results showed that virgin asphalt was compatible with SBS modifiers to improve cohesiveness. The cohesive power of branched SBS-modified asphalt was larger than that of linear SBS-modified asphalt. The cohesion of SBS-modified asphalt was improved as the SBS modifier and stabilizer contents increased but was reduced for excessive extraction oil contents. The cohesive characteristics of the SBS-modified asphalt were improved by the formation of stable three-dimensional network structures by cross-linking, winding, and grafting among different raw materials.

  16. Response surface methodology for predicting quality characteristics of beef patties added with flaxseed and tomato paste.

    Science.gov (United States)

    Valenzuela Melendres, M; Camou, J P; Torrentera Olivera, N G; Alvarez Almora, E; González Mendoza, D; Avendaño Reyes, L; González Ríos, H

    2014-05-01

    Response surface methodology was used to study the effect of flaxseed flour (FS) and tomato paste (TP) addition, from 0 to 10% and 0 to 20% respectively, on beef patty quality characteristics. The assessed quality characteristics were color (L, a, and b), pH and texture profile analysis (TPA). Also, sensory analysis was performed for the assessment of color, juiciness, firmness, and general acceptance. FS addition reduced L and a values and decreased weight loss of cooked products (Pparameters decreased when percentages of FS and TP were increased in the formulation of beef patties. Furthermore, FS and TP addition adversely affected the sensory characteristics of the cooked product (P5.6). Thus FS and TP are ingredients that can be used in beef patty preparation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Mathematical relationships for metal build-up on urban road surfaces based on traffic and land use characteristics.

    Science.gov (United States)

    Gunawardena, Janaka; Ziyath, Abdul M; Egodawatta, Prasanna; Ayoko, Godwin A; Goonetilleke, Ashantha

    2014-03-01

    The study investigated the influence of traffic and land use parameters on metal build-up on urban road surfaces. Mathematical relationships were developed to predict metals originating from fuel combustion and vehicle wear. The analysis undertaken found that nickel and chromium originate from exhaust emissions, lead, copper and zinc from vehicle wear, cadmium from both exhaust and wear and manganese from geogenic sources. Land use does not demonstrate a clear pattern in relation to the metal build-up process, though its inherent characteristics such as traffic activities exert influence. The equation derived for fuel related metal load has high cross-validated coefficient of determination (Q(2)) and low Standard Error of Cross-Validation (SECV) values which indicates that the model is reliable, while the equation derived for wear-related metal load has low Q(2) and high SECV values suggesting its use only in preliminary investigations. Relative Prediction Error values for both equations are considered to be well within the error limits for a complex system such as an urban road surface. These equations will be beneficial for developing reliable stormwater treatment strategies in urban areas which specifically focus on mitigation of metal pollution. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. The influences of consumer characteristics on the amount of rice consumption

    Science.gov (United States)

    Supriana, T.; Pane, TC

    2018-02-01

    This study aimed to analyze the characteristics of rice consumers and the influences of consumer characteristics on the amount of rice consumption. The research areas were determined purposively in the sub-districts with the most significant population in Medan City. The analytical methods used were descriptive and multiple linear regression analysis. The results showed that consumers in the study areas have various characteristics, concerning age, income, family size, health, and education. Simultaneously, characteristics of rice consumers have the significant effect on the amount of rice consumed. Partially, age and the number of family members have the significant effect on the amount of rice consumed. The implications of this research are, need different policies toward consumers of rice based on their income strata. Rice policies cannot be generalized.

  19. The influence of wind speed on surface layer stability and turbulent ...

    Indian Academy of Sciences (India)

    wind regime (Mahrt et al. ... Influence of wind speed on surface layer stability and turbulent fluxes. 1401. Table 1. Specifications of the eddy ..... different soil and vegetation properties and other regional climatic factors. Earlier, it was found that.

  20. Influence of engineered surface on cell directionality and motility

    International Nuclear Information System (INIS)

    Tang, Qing Yuan; Pang, Stella W; Tong, Wing Yin; Shi, Peng; Lam, Yun Wah; Shi, Jue

    2014-01-01

    Control of cell migration is important in numerous key biological processes, and is implicated in pathological conditions such as cancer metastasis and inflammatory diseases. Many previous studies indicated that cell migration could be guided by micropatterns fabricated on cell culture surfaces. In this study, we designed a polydimethylsiloxane cell culture substrate with gratings punctuated by corners and ends, and studied its effects on the behavior of MC3T3-E1 osteoblast cells. MC3T3-E1 cells elongated and aligned with the gratings, and the migration paths of the cells appeared to be guided by the grating pattern. Interestingly, more than 88% of the cells cultured on these patterns were observed to reverse their migration directions at least once during the 16 h examination period. Most of the reversal events occurred at the corners and the ends of the pattern, suggesting these localized topographical features induce an abrupt loss in directional persistence. Moreover, the cell speed was observed to increase temporarily right after each directional reversal. Focal adhesion complexes were more well-established in cells on the angular gratings than on flat surfaces, but the formation of filipodia appeared to be imbalanced at the corners and the ends, possibly leading to the loss of directional persistence. This study describes the first engineered cell culture surface that consistently induces changes in the directional persistence of adherent cells. This will provide an experimental model for the study of this phenomenon and a valuable platform to control the cell motility and directionality, which can be used for cell screening and selection. (paper)

  1. Space-time Characteristics and Experimental Analysis of Broadening First-order Sea Clutter in HF Hybrid Sky-surface Wave Radar

    Directory of Open Access Journals (Sweden)

    Y.J. Li

    2014-09-01

    Full Text Available In high frequency (HF hybrid sky-surface wave radar, the first-order sea clutter broadening is very complex and serious under the influence of ionosphere and bistatic angle, which affects the detection of ship target. This paper analyzes the space-time characteristics based on the HF sky-surface wave experimental system. We first introduce the basic structure, working principle and position principle based on our experimental system. Also analyzed is the influence of ionosphere and bistatic angle on the space-time coupling characteristics of broadening first-order sea clutter and the performance of space-time adaptive processing (STAP. Finally, the results of theoretic analysis are examined with the experimental data. Simulation results show that the results of experiment consist with that of theoretic analysis.

  2. [Distribution Characteristics of Fluoroquinolones Antibiotics in Surface Water and Groundwater from Typical Areas in A City].

    Science.gov (United States)

    Cui, Ya-feng; He, Jiang-tao; Su, Si-hui; Yang, Lei; Qiao, Xiao-cui

    2015-11-01

    In order to investigate the characteristics of 5 typical kinds of fluoroquinolones (FQs) pollution in waters from a city, surface water and groundwater samples from main drainage rivers and typical areas were collected, respectively. The conventional test and FQs concentrations analysis of the water samples were conducted. The results showed the concentration and composition of FQs in groundwater differed substantially from those in surface water. The average concentration of FQs in surface water was 789.1 ng x L(-1) with the main components of ofloxacin (OFL) and lomefloxacin (LOM). This value was higher than the average concentration of FQs in groundwater: 342.7 ng x L(-1) with the main components of norfloxacin (NOR) and lomefloxacin (LOM). The enrofloxacin (ENR) exhibited relatively lower levels in both surface water and groundwater as compared to others. The highest FQs concentrations in surface water were found in trenches, followed by tributaries and the main stream. For groundwater, FQs concentrations were relatively higher in the sewage riverside. A decreasing trend of FQs concentration was monitored with the increasing distance of sampling points to the drainage rivers and all components mentioned above showed similar changing trends. The results of this study preliminarily indicated that FQs in groundwater along the riverside probably came from the surface water.

  3. The relationship of seismic velocity structure and surface fracture characteristics of basalt outcrops to rippability estimates

    International Nuclear Information System (INIS)

    Kay, S.E.; Dougherty, M.E.; Pelton, J.R.

    1994-01-01

    Seismic velocity has been shown in previous engineering studies to be related to the fracture characteristics and rippability of rock outcrops. However, common methods of measuring seismic velocity in outcrops do not take into account the many possible travel paths for wave propagation and the fact that velocity zones may exist within an outcrop. Presented here are the results of using raytracing inversion of first-arrival travel-time data to map P-velocity structure in basalt outcrops, and also the investigation of the relationship of the mapped velocities to observed surface fractures and hand-sample P-velocities. It is shown that basalt outcrops commonly consist of an irregular near-surface low-velocity zone underlain by higher velocity material; that velocity gradients can exist in outcrops; that hand-sample velocity measurements are typically higher than outcrop-scale measurements; and that the characteristics of surface fractures are empirically related to near-surface P-velocity. All of these findings are relevant to the estimated rippability of rock in geotechnical engineering. The data for this study are derived from eleven sites on basalt outcrops of the Troodos Ophiolite in Cyprus. The basalt types include pillow basalts, massive flows, and a pillow breccia. A commonly available raytracing inversion program (RAYINVR) was used to produce a velocity profile of each outcrop. Different velocity zones were detailed by inverting observed travel times to produce a model of outcrop velocity structure which produces rippability profiles for each outcrop. 16 refs., 9 figs

  4. The influence of housing characteristics on rural migrants’ living condition in Beijing Fengtai District

    Directory of Open Access Journals (Sweden)

    Liu Wen Tao

    2015-08-01

    Full Text Available The study analyzes the influence of housing characteristics on rural migrants’ living condition in Beijing Fengtai District, China. The researcher will identify rural migrants in Beijing, examine their housing characteristics (housing crowding, housing privacy and housing facility and the influence on their living condition. Also, some suggestions are given to improve their housing characteristics and living condition. The government should revise the migrant housing policy and hukou management. Also, the rural migrants should try to increase their education level and social skills. For the occupation, the local government should give the rural migrants more job opportunity. These issues are analyzed in relation to local government attitudes toward the rural migrants. The analysis is based on data collected from two types of interviews: rural migrants and management interviews which examine the rural migrants’ housing and managerial aspects of this research, respectively. It is also supported by the utilization of secondary data. The findings of the study indicate that the rural migrants’ housing characteristics (housing crowding, housing privacy and housing facility highly influence their living condition in Beijing Fengtai District. Therefore, the local government should give some assistance to this group people in the big cities. This paper reports on the findings of a study to seek acknowledged definitions of the terms Project and Project Management. The study was based on a conventional review and analysis of the definitions from a series of texts.

  5. Influence of sociodemographic characteristics on different dimensions of household food insecurity in Montevideo, Uruguay.

    Science.gov (United States)

    Rossi, Máximo; Ferre, Zuleika; Curutchet, María Rosa; Giménez, Ana; Ares, Gastón

    2017-03-01

    To determine the factor structure of the Latin American & Caribbean Household Food Security Scale (ELCSA) and to study the influence of sociodemographic characteristics on each of the identified dimensions in Montevideo, Uruguay. Cross-sectional survey with a representative sample of urban households. Household food insecurity was measured using the ELCSA. The percentage of respondents who gave affirmative responses for each of the items of the ELCSA was determined. Exploratory factor analysis was carried out to determine the ELCSA's factor structure. A probit model was used to determine the impact of some individual and household sociodemographic characteristics on the identified dimensions of food insecurity. Metropolitan area centred on Montevideo, the capital city of Uruguay, April-September 2014. Adults aged between 18 and 93 years (n 742). The percentage of affirmative responses to the items of the ELCSA ranged from 4·4 to 31·7 %. Two factors were identified in the exploratory factor analysis performed on data from households without children under 18 years old, whereas three factors were identified for households with children. The identified factors were associated with different severity levels of food insecurity. Likelihood of experiencing different levels of food insecurity was affected by individual characteristics of the respondent as well as characteristics of the household. The influence of sociodemographic variables varied among the ELCSA dimensions. Household income had the largest influence on all dimensions, which indicates a strong relationship between income and food insecurity.

  6. Seasonal features of atmospheric surface-layer characteristics over a tropical coastal station in Southern India

    International Nuclear Information System (INIS)

    Hari Prasad, K.B.R.R.; Srinivas, C.V.; Baskaran, R.; Venkatraman, B.

    2016-01-01

    Dispersion of air-borne effluents occurs in the atmospheric boundary layer (ABL) where turbulence is the main physical processes. In the surface layer of ABL, the mechanical (shear) generation of turbulence exceeds the buoyant generation or consumption of turbulence. In this layer, under steady state and horizontally homogeneous conditions various forces in the governing equation can be neglected and one can apply Monin-Obukhov Similarity Theory (MOST) to estimate the turbulent fluxes and other surface layer variables. Understanding the turbulent characteristics of the surface layer is vital for modeling of turbulent diffusion in regional numerical weather and pollution dispersion models. The objective of this study is to verify the validity of the MOST at the coastal site Kalpakkam under various atmospheric stability conditions with respect to different seasons for modeling atmospheric dispersion of radioactive effluents

  7. A comparative study of the influence of nickel oxide layer on the FTO surface of organic light emitting diode

    Science.gov (United States)

    Saikia, Dhrubajyoti; Sarma, Ranjit

    2018-03-01

    The influence of thin layer of nickel oxide (NiO) over the fluorine-doped tin oxide (FTO) surface on the performance of Organic light-emitting diode (OLED) is reported. With an optimal thickness of NiO (10 nm), the luminance efficiency is found to be increased as compared to the single FTO OLED. The performance of OLED is studied by depositing NiO films at different thicknesses on the FTO surface and analyzed their J-V and L-V characteristics. Further analysis is carried out by measuring sheet resistance and optical transmittance. The surface morphology is studied with the help of FE-SEM images. Our results indicate that NiO (10 nm) buffer layer is an excellent choice to increase the efficiency of FTO based OLED devices within the charge tunneling region. The maximum value of current efficiency is found to be 7.32 Cd/A.

  8. Study on decaying characteristics of activated sludge from a circular plug-flow reactor using response surface methodology.

    Science.gov (United States)

    Xie, En; Ding, Aizhong; Dou, Junfeng; Zheng, Lei; Yang, Jin

    2014-10-01

    Using pH values, temperature, and dissolved oxygen as the influencing factors, a decaying characteristics experiment of activated sludge was carried out by combining the LIVE/DEAD® Baclight technique with the 2,3,5-triphenyl tetrazolium chloride - dehydrogenase activity determination method. Using batch experiments, a response surface methodology was applied in the experimental design to determine the most important influential factor in the decay of activated sludge. The activated sludge mixed liquor for the experiment was generated in a laboratory-scale circular plug-flow reactor, which has already been approved for an invention patent. The analyzed results revealed that the most important influential factor in sludge activity decay is the pH, followed by temperature and then dissolved oxygen. After the decay experiment, 40.94-90.03% of sludge activity decay is caused by reduced cell activity, and the rest is due to cell death. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Influence of the brittle behavior of work materials on polishing characteristics

    Science.gov (United States)

    Sakamoto, Satoshi; Gemma, Masaya; Hayashi, Keitoku; Kondo, Yasuo; Yamaguchi, Kenji; Yakou, Takao; Arakawa, Susumu

    2017-09-01

    Diamond electrodeposited wire tools are frequently used to cut thin wafers from hard and brittle materials. However, microcracks sometimes appear during the slicing process. The appearance of microcracks adversely affects slicing efficiency and slicing accuracy. In this study, we examine the influence of brittle behavior on the polishing characteristics such as polishing depth and tool wear. This is the first step toward investigating the influence of the brittle behavior of work materials on slicing characteristics. Ceramics such as alumina, silicon carbide, and zirconia are used as work materials. Even with the same degree of hardness, we found that the polishing depth values were greater for materials exhibiting brittle behavior. In the polishing of high-hardness materials, abrasive grains were badly damaged during the initial stages of polishing. Damage to the abrasive paper was less in wet polishing as compared with dry polishing. Moreover, wet polishing had a greater polishing depth than dry polishing. The polishing characteristics of the brittle materials were similar to the grooving characteristics produced using wire tools; however, both these characteristics depend on the brittle behavior of the work materials. Therefore, by performing simple polishing tests, estimating the state of grooving or slicing using wire tools is possible.

  10. Influence of surface activated carbon nano fibres on mechanical properties of poly ether ketone (PEK)

    Science.gov (United States)

    Ajeesh, G.; Bhowmik, S.; Sivakumar, V.; Varshney, L.

    2017-05-01

    This investigation highlights different surface functionalization processes of Carbon Nano Fibres (CNF’s) and their effects on mechanical properties of Polyetherketone (PEK) nano composite. Surfaces of CNF’s were modified by low pressure plasma process. There is a significant change in physico-chemical characteristics of CNF’s after low plasma treatment as evident from Transmission Electron Microscopy (TEM) and Fourier Transform infrared Spectroscopic (FTIR) studies. Significant modification in surface morphology and oxygen functionalities are observed as a result of surface modification. There is a significant increase in mechanical properties of high performance polymeric nano composites when surface functionalized CNF’s are dispersed in polymeric matrix.

  11. Anisotropic wetting characteristics versus roughness on machined surfaces of hydrophilic and hydrophobic materials

    International Nuclear Information System (INIS)

    Liang, Yande; Shu, Liming; Natsu, Wataru; He, Fuben

    2015-01-01

    Graphical abstract: - Highlights: • The aim is to investigate the influence of roughness on anisotropic wetting on machined surfaces. • The relationship between roughness and anisotropic wetting is modeled by thermodynamical analysis. • The effect of roughness on anisotropic wetting on hydrophilic materials is stronger than that on hydrophobic materials. • The energy barrier existing in the direction perpendicular to the lay is one of the main reasons for the anisotropic wetting. • The contact angle in the parallel direction is larger than that in the perpendicular direction. - Abstract: Anisotropic wetting of machined surfaces is widely applied in industries which can be greatly affected by roughness and solid's chemical properties. However, there has not been much work on it. A free-energy thermodynamic model is presented by analyzing geometry morphology of machined surfaces (2-D model surfaces), which demonstrates the influence of roughness on anisotropic wetting. It can be concluded that the energy barrier is one of the main reasons for the anisotropic wetting existing in the direction perpendicular to the lay. In addition, experiments in investigating anisotropic wetting, which was characterized by the static contact angle and droplet's distortion, were performed on machined surfaces with different roughness on hydrophilic and hydrophobic materials. The droplet's anisotropy found on machined surfaces increased with mean slope of roughness profile Kr. It indicates that roughness on anisotropic wetting on hydrophilic materials has a stronger effect than that on hydrophobic materials. Furthermore, the contact angles predicted by the model are basically consistent with the experimentally ones

  12. Influence of hydrophobic surface treatment toward performance of air filter

    Science.gov (United States)

    Shahfiq Zulkifli, Nazrul; Zaini Yunos, Muhamad; Ahmad, Azlinnorazia; Harun, Zawati; Akhair, Siti Hajar Mohd; Adibah Raja Ahmad, Raja; Hafeez Azhar, Faiz; Rashid, Abdul Qaiyyum Abd; Ismail, Al Emran

    2017-08-01

    This study investigated the performance of hydrophobic surface treatment by using silica aerogel powder via spray coating techniques. Hydrophobic properties were determined by measuring the level of the contact angle. Meanwhile, performance was evaluated in term of the hydrogen gas flow and humidity rejection. The results are shown by contact angle that the microstructure filter, especially in the upper layer and sub-layer has been changed. The results also show an increase of hydrophobicity due to the increased quantity of silica aerogel powder. Results also showed that the absorption and rejection filter performance filter has increased after the addition of silica aerogel powder. The results showed that with the addition of 5 grams of powder of silica aerogel have the highest result of wetting angle 134.11°. The highest humidity rejection found with 5 grams of powder of silica aerogel.

  13. Evaluation of the influence of seasonality and landscape on the physicochemical characteristics of propolis

    Directory of Open Access Journals (Sweden)

    Elaine Maria Loureiro

    2013-12-01

    Full Text Available This study aimed at verifying the influence of the seasonality and landscape of the place of apiaries in the production and physicochemical quality of propolis produced in Cáceres-MT. Within August/2006 and July/2007 twenty-three propolis samples were collected monthly. The physicochemical quality of propolis was determined by the characteristic: loss by drying, wax, mechanical mass, oxidation activity, dry extract, flavonoids and total phenolics. The production of propolis was analyzed through correlation with seasonality (dry and wet. The same statistic model was used to correlate the production with the landscape (highland and flood plain. For each physicochemical characteristic were used statistic model of correlation described for the production of propolis. The seasonality did not influence on propolis production and on physicochemical quality. The landscape did not influence on propolis production and physicochemical quality loss by drying and mechanical mass, however, it determined the physicochemical quality for wax (x=22.44%, oxidation activity (x=9.73'', dry extract (x=22.31%, flavonoids (x=1.94% and total phenolics (x=0.02% in the highland of the Pantanal of Cáceres. This way it concludes that the production and physicochemical quality of propolis were not influenced by seasonality. The landscape influenced positively on physicochemical quality of propolis in the highland of the Pantanal of Cáceres.

  14. Fabrication of high aspect ratio nanopillars and micro/nano combined structures with hydrophobic surface characteristics by injection molding

    Science.gov (United States)

    Zhou, Mingyong; Xiong, Xiang; Jiang, Bingyan; Weng, Can

    2018-01-01

    Polymer products with micro/nano-structures have excellent mechanical and optical properties, chemical resistance, and other advantages. Injection molding is one of the most potential techniques to fabricate polymer products with micro/nano-structures artificially in large numbers. In this study, a surface approach to fabricate high aspect ratio nanopillars and micro/nano combined structures was presented. Mold insert with micropillar arrays and nanopillars on its surface was prepared by combing anodic aluminum oxide (AAO) template and etched plate. Anti-sticking modification was done on the template to realize a better demolding quality. The influences of mold temperature and polymer material on the final replication quality were investigated. The results showed that the final replication quality of high aspect ratio nanopillars was greatly improved as compared with the unprocessed template. Polymer with low elongation at break was not suitable to fabricate structures with high aspect ratio via injection molding. For polypropylene surface, the experimental results of static contact angles were almost consistent with Cassie-Baxter equation. When the mold temperature reached 178 °C, hair-like polycarbonate nanopillars were observed, resulting in an excellent hydrophobic characteristic.

  15. Influence of magnet eddy current on magnetization characteristics of variable flux memory machine

    Science.gov (United States)

    Yang, Hui; Lin, Heyun; Zhu, Z. Q.; Lyu, Shukang

    2018-05-01

    In this paper, the magnet eddy current characteristics of a newly developed variable flux memory machine (VFMM) is investigated. Firstly, the machine structure, non-linear hysteresis characteristics and eddy current modeling of low coercive force magnet are described, respectively. Besides, the PM eddy current behaviors when applying the demagnetizing current pulses are unveiled and investigated. The mismatch of the required demagnetization currents between the cases with or without considering the magnet eddy current is identified. In addition, the influences of the magnet eddy current on the demagnetization effect of VFMM are analyzed. Finally, a prototype is manufactured and tested to verify the theoretical analyses.

  16. The influence of the pyrolysis conditions in a rotary oven on the characteristics of the products

    OpenAIRE

    Acevedo Muñoz, Beatriz; Barriocanal Rueda, Carmen

    2014-01-01

    The pyrolysis of 1:1 blends of reinforcing fibre (RF) from tyre wastes with low rank bituminous coal was carried out in a rotary oven. The pyrolysis conditions were modified in order to study their influence on the yield and characteristics of the char and oil obtained. The variables studied were as follows: rotation speed, final pyrolysis temperature, N2 flow and heating rate. The textural characteristics of the char were studied by means of N2 adsorption at 77 K, whereas the oil composition...

  17. The Influence of Top Management Team Characteristics on BPD Performance (P.155-166

    Directory of Open Access Journals (Sweden)

    Joy Elly Tulung

    2017-01-01

    Full Text Available Based on ”upper echelons theory”, this paper investigates the relation between top management team composition and BPD performance. For top management team characteristics, we employ age, level of education, background of education, gender, and functional background, while for measured the BPD performance we employ return on asset (ROA, return on equity (ROE, capital adequacy ratio (CAR, net interest margin (NIM, loan to deposit ratio (LDR, non-performing loan (NPL and operation expenses to operation income (BOPO. The results show that all characteristics have positive significant influences on BPD performance.Keywords: Top Management Team,BPD Performance, Upper Echelons Theory 

  18. INFLUENCE OF PLANNING, ORGANIZATIONAL CHARACTERISTICS AND REGULATION ON ROAD TRAFFIC SAFETY OF PEDESTRIANS

    Directory of Open Access Journals (Sweden)

    G. M. Kuharenok

    2011-01-01

    Full Text Available The paper presents results of research on planning, organizational characteristics and regulation modes at  the regulated pedestrian crossings, located out of crossroads in the street and road network of Minsk. Some regularities pertaining to the influence of the investigated characteristics on road traffic safety of pedestrians are revealed in the paper. Practical offers on increase of road traffic safety of pedestrians in the Republic of Belarus have been developed on the basis of the executed investigations and cited in the paper. 

  19. The influence of spectral and spatial characteristics of early reflections on speech intelligibility

    DEFF Research Database (Denmark)

    Arweiler, Iris; Buchholz, Jörg; Dau, Torsten

    mostly been addressed by manipulating the temporal characteristics of ERs. To achieve a more complete picture, the present study investigates the influence of the spectral and spatial characteristics of ERs on speech intelligibility. Speech intelligibility tests were performed with 9 normal-hearing and 8...... hearing-impaired listeners in a virtual auditory environment. In this setup with 29 loudspeakers, the amplitude of the DS and the ERs could be varied independently. The ER pattern was taken from a classroom simulated with the room acoustic software Odeon. Thus, the spectral, spatial and temporal...

  20. The influence of education on chosen typographical characteristics perception in documents

    Directory of Open Access Journals (Sweden)

    Petra Talandová

    2008-01-01

    Full Text Available This paper concentrates on the problems of documents quality evaluation and perception. It presents the results of our own research which was made at our faculty in last months. The research was aimed at marketing materials, their quality and their evaluation by customers. After another comparative research we have concentrated on the question of typography and its evaluation by customers. It has been proved that typography, although not very visible for many readers, does influence readers' evaluation of the whole document.Quality evaluation is influenced by what readers usually see around them but also by what are they taught at schools. For that reason we should influence readers and teach them how should be documents designed. Future specialist should know about this problem.Aim of the research was to find how typography influences readers and whether is the typographic quality evaluation influenced by teaching at school. We have been comparing two groups of respondents, of which one was influenced by typography education and one was not. Respondent were asked to fill in a questionnaire which concentrated on right and wrong characteristic of the text. Result analysis has proved that the group influenced by typography lessons had better results. These conclusions will be applied in the new education plan for an innovation of education courses.

  1. Influence of moulding conditions and mould characteristics on the contraction defects appearance in ductile iron castings

    International Nuclear Information System (INIS)

    Sertucha, J.; Suarez, R.; Legazpi, J.; Gacetabeitia, P.

    2007-01-01

    Shrinkage defects appearance in cast iron has traditionally been related to the solidification processes of the metal and the feedings ability among the different sections of castings. Recent studies have demonstrated that sand moulds properties and their thermal behaviour after pouring step have an important influence on these defects formation too. The influence of the moulding process parameters and the mould characteristics on the contraction defects is analysed in this work using test casting designed specifically for this purpose. Additionally the most important parameters are determined in order to control the manufacturing process and minimise the shrinkage appearance in the castings. (Author) 14 refs

  2. Influence of surface microstructure and chemistry on osteoinduction and osteoclastogenesis by biphasic calcium phosphate discs.

    NARCIS (Netherlands)

    Davison, N.L.; Su, J.; Yuan, H.; Beucken, J.J.J.P van den; Bruijn, J.D. de; rrere-de Groot, F. Ba

    2015-01-01

    It has been reported that surface microstructural dimensions can influence the osteoinductivity of calcium phosphates (CaPs), and osteoclasts may play a role in this process. We hypothesised that surface structural dimensions of

  3. Influence of surface preparation on the corrosion performance of epoxy coatings for ship ballast tank

    NARCIS (Netherlands)

    Zhang, X.; Buter, S.J.; Ferrari, G.M.

    2011-01-01

    The surface preparation has influence on the adhesion for coatings and consequently affect the corrosion performance of the coatings. The international Maritime Organization (IMO) has adopted a Performance Standard for Protective Coatings (PSPC) on the surface preparation for ballast tanks. However,

  4. Influence of Surface Morphology on the Antimicrobial Effect of Transition Metal Oxides in Polymer Surface.

    Science.gov (United States)

    Oh, Yoo Jin; Hubauer-Brenner, Michael; Hinterdorfer, Peter

    2015-10-01

    In this study, the physical properties of transition metal oxide surfaces were examined using scanning probe microscopic (SPM) techniques for elucidating the antimicrobial activity of molybdenum trioxide (MoO3), tungsten trioxide (WO3), and zinc oxide (ZnO) embedded into the polymers thermoplastic polyurethane (TPU) and polypropylene (PP). We utilized atomic force microscopy (AFM) in the contact imaging mode and its derivative single-pass Kelvin probe force microscopy for investigating samples that were presumably identical in their compositions, but showed different antimicrobial activity in bacterial adhesion tests. Our results revealed that surfaces with larger roughness and higher surface potential variation showed stronger antimicrobial activities compared to smoother and homogeneously charge-distributed surfaces. In addition, capacitance gradient (dC/dZ) measurements were performed to elucidate the antimicrobial activity arising from the different dielectric behavior of the transition metal oxides in this heterogeneous polymer surface. We found that the nano-scale exposure of transition metal oxides on polymer surfaces provided strong antimicrobial effects. Applications arising from our studies will be useful for public and healthcare environments.

  5. Oxidation characteristics of the electron beam surface-treated Alloy 617 in high temperature helium environments

    International Nuclear Information System (INIS)

    Lee, Ho Jung; Sah, Injin; Kim, Donghoon; Kim, Hyunmyung; Jang, Changheui

    2015-01-01

    The oxidation characteristics of the electron beam surface-treated Alloy 617, which has an Al-rich surface layer, were evaluated in high temperature helium environments. Isothermal oxidation tests were performed in helium (99.999% purity) and VHTR-helium (helium of prototypical VHTR chemistry containing impurities like CO, CO 2 , CH 4 , and H 2 ) environments at 900 °C for up to 1000 h. The surface-treated Alloy 617 showed an initial transient oxidation stage followed by the steady-state oxidation in all test environments. In addition, the steady-state oxidation kinetics of the surface-treated Alloy 617 was 2-order of magnitude lower than that of the as-received Alloy 617 in both helium environments as well as in air. The improvement in oxidation resistance was primarily due to the formation of the protective Al 2 O 3 layer on the surface. The weight gain was larger in the order of air, helium, and VHTR-helium, while the parabolic rate constants (k p ) at steady-state were similar for all test environments. In both helium environments, the oxide structure consisted of the outer transition Al 2 O 3 with a small amount of Cr 2 O 3 and inner columnar structured Al 2 O 3 without an internal oxide. In the VHTR-helium environment, where the impurities were added to helium, the initial transient oxidation increased but the steady state kinetics was not affected

  6. Evaluation of Acid Etching on Surface Characteristics, Strength and Biological Response of Glass-Infiltrated Zirconia.

    Science.gov (United States)

    Vu, Van Thi; Oh, Gye-Jeong; Lim, Hyun-Pil; Yun, Kwi-Dug; Kim, Ji-Won; Park, Sang-Won

    2018-03-01

    This study evaluated the effect of acid etching on surface characteristics, flexural strength and osteoblast cell response of glass-infiltrated zirconia. Zirconia specimens were divided into six groups: untreated zirconia (Z); glass-infiltrated zirconia (ZG); glass-infiltrated and sandblasted zirconia (ZGS); glass-infiltrated, sandblasted and 5 min acid-etched zirconia (ZGS-E5); glassinfiltrated, sandblasted and 15 min acid-etched zirconia (ZGS-E15); glass-infiltrated, sandblasted and 25 min acid-etched zirconia (ZGS-E25). Surface roughness, biaxial flexural strength and MC3T3-E1 cell proliferation were evaluated. When increasing etching time, surface roughness significantly increased while flexural strength decreased. Cell proliferation rate at day 3 on group ZGS-E15 and ZGS-E25 was significantly higher than that of other groups. Surface roughness and flexural strength of glass-infiltrated zirconia can be controlled by adjusting etching time. Rough surface made by acid etching following glass infiltration significantly enhanced osteoblast cell response. Glass infiltration improved strength of zirconia but severe acid etching slightly reduced strength of zirconia.

  7. Influence of Sea Surface Roughness on the Electromagnetic Wave Propagation in the Duct Environment

    OpenAIRE

    Zhao, X.; Huang, S.

    2010-01-01

    This paper deals with a study of the influence of sea surface roughness on the electromagnetic wave propagation in the duct environment. The problem of electromagnetic wave propagation is modeled by using the parabolic equation method. The roughness of the sea surface is computed by modifying the smooth surface Fresnel reflection coefficient to account for the reduction in the specular reflection due to the roughness resulting from sea wind speed. The propagation model is solved by the mixed ...

  8. Influence of sampling points on inspection accuracy of free-form surfaces using coordinate measuring machine

    Science.gov (United States)

    Xie, Mengmin; Chen, Yueping; Zhang, Anshe; Fang, Rui

    2018-03-01

    The inspection accuracy of free-form surfaces is mainly affected by the processing, the number of sampling points, the distribution of sampling points, the measurement equipment and other factors. This paper focuses on the influence of sampling points on inspection accuracy of free-form surfaces, and isoparametric distribution was used in sample point distribution. Different sampling points number was compared on a same surface and a probe, the measurement data were analyzed and the optimal sampling points number was obtained.

  9. Body mass index in multiethnic midlife women: influence of demographic characteristics and physical activity.

    Science.gov (United States)

    Choi, Jiwon; Guiterrez, Yolanda; Gilliss, Catherine; Lee, Kathryn A

    2011-12-01

    We examined the influence of demographic characteristics and physical activity on body mass index (BMI) in multiethnic midlife women. A sample of 236 African, European, and Mexican/Central Americans aged 40-50 completed the initial, 1-year, and 2-year assessments. The effects of demographic characteristics and physical activity on BMI at the 2-year assessment were evaluated using hierarchical multiple regression analysis. After controlling for other demographic factors, ethnicity, annual household income, and physical activity at the initial assessments were significant predictors of BMI. Body mass index (BMI) may be influenced by socioeconomic status as well as ethnicity. Regular physical activity should be encouraged to maintain a healthy BMI in midlife women.

  10. Biological characteristics that influence the SEUROP system classification for Czech fleckvieh and Holstein bull carcasses

    Directory of Open Access Journals (Sweden)

    Radek Filipčík

    2006-01-01

    Full Text Available The aim of this work was to analyse the influence of certain characteristics (aptitude, age, carcass weight, net daily gain, feeding on the final carcass classification in the SEUROP system. 703 Czech Fleckvieh bulls and 642 Holstein bulls were studied. The animals were slaughtered and evaluated at a designated beef processing company. Combine aptitude carcasses shown significant differences between characteristics. Remarkable differences of group averages (P>0, 01 were established between farms and they were due to various rearing conditions. Also the levels of net daily gain between aptitudes were proved significantly. Holstein breed showed significant difference among The net daily gain < 500 g.day–1 and levels 551–600; 601–650 and above 651 g.day–1. The SEUROP system is influenced the most by the feeding regime, which is described by a net daily gain in this work, and farm impact.

  11. Electrical conductivity of conductive carbon blacks: influence of surface chemistry and topology

    International Nuclear Information System (INIS)

    Pantea, Dana; Darmstadt, Hans; Kaliaguine, Serge; Roy, Christian

    2003-01-01

    Conductive carbon blacks from different manufacturers were studied in order to obtain some insight into the relation between their electrical conductivity and their surface properties. The surface chemistry was studied by X-ray photoelectron spectroscopy (XPS) and static secondary ion mass spectroscopy (SIMS), whereas the topology of the carbon black surface was investigated using low-pressure nitrogen adsorption. All these techniques yield information on the graphitic character of the surface. In general, the electrical conductivity of the conductive blacks increases with the graphitic character of the surface. For low surface area conductive blacks, the electrical conductivity correlates well with the surface chemistry. In the case of the XPS and SIMS data, this correlation is also valid when other types of carbon blacks such as thermal and furnace blacks are included, confirming the determining influence of the carbon black surface chemistry on the electrical conductivity

  12. Surface energy characteristics of zeolite embedded PVDF nanofiber films with electrospinning process

    Science.gov (United States)

    Kang, Dong Hee; Kang, Hyun Wook

    2016-11-01

    Electrospinning is a nano-scale fiber production method with various polymer materials. This technique allows simple fiber diameters control by changing the physical conditions such as applied voltage and polymer solution viscosity during the fabrication process. The electrospun polymer fibers form a thin porous film with high surface area to volume ratio. Due to these unique characteristics, it is widely used for many application fields such as photocatalyst, electric sensor, and antibacterial scaffold for tissue engineering. Filtration is one of the main applications of electrospun polymer fibers for specific application of filtering out dust particles and dehumidification. Most polymers which are commonly used in electrospinning are hard to perform the filtering and dehumidification simultaneously because of their low hygroscopic property. To overcome this obstacle, the desiccant polymers are developed such as polyacrylic acid and polysulfobetaine methacrylate. However, the desiccant polymers are generally expensive and need special solvent for electrospinning. An alternating way to solve these problems is mixing desiccant material like zeolite in polymer solution during an electrospinning process. In this study, the free surface energy characteristics of electrospun polyvinylidene fluoride (PVDF) film with various zeolite concentrations are investigated to control the hygroscopic property of general polymers. Fundamental physical property of wettability with PVDF shows hydrophobicity. The electrospun PVDF film with small weight ratio with higher than 0.1% of zeolite powder shows diminished contact angles that certifying the wettability of PVDF can be controlled using desiccant material in electrospinning process. To quantify the surface energy of electrospun PVDF films, sessile water droplets are introduced on the electrospun PVDF film surface and the contact angles are measured. The contact angles of PVDF film are 140° for without zeolite and 80° for with 5

  13. Influencing factors of domestic waste characteristics in rural areas of developing countries.

    Science.gov (United States)

    Han, Zhiyong; Liu, Yong; Zhong, Min; Shi, Guozhong; Li, Qibin; Zeng, Dan; Zhang, Yu; Fei, Yongqiang; Xie, Yanhua

    2018-02-01

    Waste management in rural areas has become a major challenge for governments of developing countries. The success of waste management decisions directly lies in the accuracy and reliability of the data on which choices are based; many factors influence these data. Here, we examined the factors influencing domestic waste in rural areas of developing countries (RADIC), using both field surveys and by reviewing previous literature. The social factors included population, education and culture. There was a positive linear relationship between waste generation amount and population size (R 2  = 0.9405). Environmental education, training and demonstration projects played a positive role in improving people's awareness of the benefits of recycling and reducing waste. Traditional and national cultures, consumption and living habits contributed to variations in the generation and composition of domestic waste. Generally, practices related to conservation of and reverence for nature and green consumption encourage people to reduce, reuse and recycle waste in their daily life. Economic factors included household income and expenditure, energy and fuel structure, and types of industry that occurred in villages. A Kuznets inverted "U" curve relationship existed between domestic waste generation and people's income in rural areas of China. However, the waste generation rate had a linear relationship with the gross national income per capita in RADIC. The composition, bulk density and calorific value of domestic waste were variously affected by the energy and fuel structure and the types of industry that occurred. The natural factors included geography and climate (including rainfall, humidity, temperature and harvest seasons). The moisture content of waste was directly influenced by rainfall and humidity. Temperature affected waste characteristics by influencing residential heating modes. The waste characteristics were also influenced by the mixing of agricultural and

  14. The stratified flows' characteristics: A numerical study of the influence of technological parameters

    Science.gov (United States)

    Bachurina, Maria V.; Trufanova, Nataliia M.; Kazakov, Alexey V.

    2014-05-01

    Made of polymers with certain supplements multilayer insulation and shielding coatings have a great potential nowadays. An extrusion method of insulation is still the most practically feasible one. Since the covering technology is a simultaneous imposition of all necessary layers (two the semiconducting shields on the insulation and on the conductor and the insulation), of current importance analysis of the influence of various factors on stratified flows' characteristics.

  15. Influence the Rubber Seed Type and Altitude on Characteristic of Seed, Oil and Biodiesel

    OpenAIRE

    Salni Salni; Poedji Loekitowati Hariani; Hanifa Marisa Hanifa

    2017-01-01

    This research studies the influence of the type of rubber seed that is superior and local, altitude plant in South Sumatra province to the characteristic of seed, oil and biodiesel (methyl ester). Rubber plants planted from local rubber seed by seeds seedlings and superior rubber seed by selected clones. In the study, rubber plants planted at a different altitude, namely in Banyuasin district (18 m above sea level), Prabumulih District (176 m above sea level) and Lahat District (627 m above s...

  16. Influence of the Rubber Seed Type and Altitude on Characteristic of Seed, Oil and Biodiesel

    OpenAIRE

    Salni, Salni; Hariani, Poedji Loekitowati; Hanifa, Hanifa Marisa

    2017-01-01

    This research studies the influence of the type of rubber seed that is superior and local, altitude plant in South Sumatra province to the characteristic of seed, oil and biodiesel (methyl ester). Rubber plants planted from local rubber seed by seeds seedlings and superior rubber seed by selected clones. In the study, rubber plants planted at a different altitude, namely in Banyuasin district (18 m above sea level), Prabumulih District (176 m above sea level) and Lahat District (627 m above s...

  17. Work ability of Chinese migrant workers: the influence of migration characteristics.

    Science.gov (United States)

    Han, Lu; Shi, Leiyu; Lu, Liming; Ling, Li

    2014-04-13

    Migrant workers have become a vital labor supply to China's economy. Their migration process and work conditions may influence their health and work ability. The work ability of migrant workers in China and the influence of the migration process on work ability have not been explored extensively in previous studies. The objective of this study is to evaluate the association of migration characteristics and work-related factors with work ability among migrant workers in the Pearl River Delta. In this cross-sectional survey, the study population consisted of 907 migrant workers from ten factories in the Pearl River Delta who were exposed to organic solvents during work. The primary dependent variable of the study was work ability, measured by the Work Ability Index (WAI). The independent variables were individual characteristics, migration characteristics, and work-related factors. Logistic regression models were used to determine the influence of different factors on work ability and three dimensions of WAI. The result shows that among migration characteristics, social support was significantly associated with all three dimensions of the work ability index. Permanent migration intention and longer length of migration were negatively associated with the mental resource dimension of WAI. WAI was also influenced by individual and work-related factors. The findings of this study suggest that expanding migrants' social networks and social support systems in their work place or living community, (i.e. expanding the functions of labor unions) would be an effective way to improve migrant workers' work ability. Improving of migrant workers' physical and psychosocial related work environments would also increase their work ability.

  18. Work ability of Chinese migrant workers: the influence of migration characteristics

    Science.gov (United States)

    2014-01-01

    Background Migrant workers have become a vital labor supply to China’s economy. Their migration process and work conditions may influence their health and work ability. The work ability of migrant workers in China and the influence of the migration process on work ability have not been explored extensively in previous studies. The objective of this study is to evaluate the association of migration characteristics and work-related factors with work ability among migrant workers in the Pearl River Delta. Methods In this cross-sectional survey, the study population consisted of 907 migrant workers from ten factories in the Pearl River Delta who were exposed to organic solvents during work. The primary dependent variable of the study was work ability, measured by the Work Ability Index (WAI). The independent variables were individual characteristics, migration characteristics, and work-related factors. Logistic regression models were used to determine the influence of different factors on work ability and three dimensions of WAI. Results The result shows that among migration characteristics, social support was significantly associated with all three dimensions of the work ability index. Permanent migration intention and longer length of migration were negatively associated with the mental resource dimension of WAI. WAI was also influenced by individual and work-related factors. Conclusions The findings of this study suggest that expanding migrants’ social networks and social support systems in their work place or living community, (i.e. expanding the functions of labor unions) would be an effective way to improve migrant workers’ work ability. Improving of migrant workers’ physical and psychosocial related work environments would also increase their work ability. PMID:24725332

  19. Surface characteristics, equipment height, and the occurrence and severity of playground injuries.

    Science.gov (United States)

    Laforest, S; Robitaille, Y; Lesage, D; Dorval, D

    2001-03-01

    To evaluate whether surface characteristics (absorption level (g-max), material) and the height of play equipment are related to the occurrence and severity of injuries from falls. During the summers of 1991 and 1995, conformity of play equipment to Canadian standards was assessed in a random sample (n = 102) of Montreal public playgrounds. Surface absorption (g-max) was tested using a Max Hic instrument and the height of equipment was measured. Concurrently, all injuries presenting at the emergency department of Montreal's two children's hospitals were recorded and parents were interviewed. Inspected equipment was implicated in 185 injuries. The g-max measurements (1995 only) were available for 110 of these playground accidents. One third of falls (35 %) occurred on a surface exceeding 200 g and the risk of injury was three times greater than for g level lower than 150 (95% confidence interval (CI) 1.45 to 6.35). On surfaces having absorption levels between 150 g and 200 g, injuries were 1.8 times more likely (95% CI 0.91 to 3.57). Injuries were 2.56 times more likely to occur on equipment higher than 2 m compared with equipment lower than 1.5 m. Analysis of risk factors by severity of injury failed to show any positive relationships between the g-max or height and severity, whereas surface material was a good predictor of severity. This study confirms the relationships between risk of injury, surface resilience, and height of equipment, as well as between type of material and severity of injury. Our data suggest that acceptable limits for surface resilience be set at less than 200 g, and perhaps even less than 150 g, and not exceed 2 m for equipment height. These findings reinforce the importance of installing recommended materials, such as sand, beneath play equipment.

  20. The spatial heterogeneity of land surface conditions and its influence on surface fluxes over a typical underlying surface in the Tibetan Plateau

    Science.gov (United States)

    Sun, Genhou; Hu, Zeyong; Wang, Jiemin; Ma, Weiqiang; Gu, Lianglei; Sun, Fanglin; Xie, Zhipeng; Yan, Xiaoqiang

    2018-01-01

    Accurately estimating the surface fluxes of over the heterogeneous land surface in Tibetan Plateau will be helpful to advance the understanding of its influence on regional climate and hydrology. This paper presents a study on the spatial heterogeneity of land surface parameters in terms of the spatial variability and spatial structure of land surface parameters and the influence on surface fluxes over a typical land surface in Tibetan Plateau. The results suggest that the sensible heat fluxes (H) and latent heat fluxes (LE) in the study area in the rain and dry seasons show apparent spatial variabilities due to the spatial heterogeneity in the leaf area index (LAI) and land surface undulations. The relative frequency distribution of H and LE at the spatial resolution of 30 m suggests that the spatial variability of surface fluxes has a close relationship with the spatial heterogeneity of land surface temperature (LST) and LAI. The variogram analyses of LST, LAI, H, and LE in the study area in rain season indicate that the spatial structures of LST and LAI are different and the spatial structures of H and LE are strongly influenced by the spatial structures of LST and LAI in both rain and dry seasons. The optimal pixel sizes for LST, LAI, H, and LE in the study area are 506, 156, 500, and 225 m in the rain season. The optimal pixel sizes for LST, H, and LE in the study area are 165, 165, and 162 m in the dry season. An analysis of the relative frequency distributions (RFDs) of the LST, LAI, H, and LE at different spatial resolutions in the rain and dry seasons reveals that their values at the maximum relative frequency keep stable although their spatial variabilities become weak as the spatial resolution decreases. The averages of LST, LAI, H, and LE of different spatial resolutions of the study area in rain and dry seasons vary within small ranges, suggesting that the influence of spatial resolution on the averaged land surface parameters and surface fluxes in the

  1. The impacts of urban surface characteristics on radiation balance and meteorological variables in the boundary layer around Beijing in summertime

    Science.gov (United States)

    Liu, Ruiting; Han, Zhiwei; Wu, Jian; Hu, Yonghong; Li, Jiawei

    2017-11-01

    In this study, some key geometric and thermal parameters derived from recent field and satellite observations in Beijing were collected and incorporated into WRF-UCM (Weather Research and Forecasting) model instead of previous default ones. A series of sensitivity model simulations were conducted to investigate the influences of these parameters on radiation balance, meteorological variables, turbulence kinetic energy (TKE), as well as planetary boundary layer height (PBLH) in regions around Beijing in summer 2014. Model validation demonstrated that the updated parameters represented urban surface characteristics more realistically and the simulations of meteorological variables were evidently improved to be closer to observations than the default parameters. The increase in building height tended to increase and slightly decrease surface air temperature at 2 m (T2) at night and around noon, respectively, and to reduce wind speed at 10 m (WS10) through a day. The increase in road width led to significant decreases in T2 and WS10 through the whole day, with the maximum changes in early morning and in evening, respectively. Both lower surface albedo and inclusion of anthropogenic heat (AH) resulted in increases in T2 and WS10 over the day, with stronger influence from AH. The vertical extension of the impact of urban surface parameters was mainly confined within 300 m at night and reached as high as 1600 m during daytime. The increase in building height tended to increase TKE and PBLH and the TKE increase was larger at night than during daytime due to enhancements of both mechanical and buoyant productions. The increase in road width generally reduced TKE and PBLH except for a few hours in the afternoon. The lower surface albedo and the presence of AH consistently resulted in increases of TKE and PBLH through both day and night. The increase in building height induced a slight divergence by day and a notable convergence at night, whereas the increase in road width

  2. Responses of herbaceous plants to urban air pollution: Effects on growth, phenology and leaf surface characteristics

    International Nuclear Information System (INIS)

    Honour, Sarah L.; Bell, J. Nigel B.; Ashenden, Trevor W.; Cape, J. Neil; Power, Sally A.

    2009-01-01

    Vehicle exhaust emissions are a dominant feature of urban environments and are widely believed to have detrimental effects on plants. The effects of diesel exhaust emissions on 12 herbaceous species were studied with respect to growth, flower development, leaf senescence and leaf surface wax characteristics. A diesel generator was used to produce concentrations of nitrogen oxides (NO x ) representative of urban conditions, in solardome chambers. Annual mean NO x concentrations ranged from 77 nl l -l to 98 nl l -1 , with NO:NO 2 ratios of 1.4-2.2, providing a good experimental simulation of polluted roadside environments. Pollutant exposure resulted in species-specific changes in growth and phenology, with a consistent trend for accelerated senescence and delayed flowering. Leaf surface characteristics were also affected; contact angle measurements indicated changes in surface wax structure following pollutant exposure. The study demonstrated clearly the potential for realistic levels of vehicle exhaust pollution to have direct adverse effects on urban vegetation. - Fumigation experiments demonstrate adverse effects of exhaust emissions on urban vegetation

  3. Correlation characteristics of signals reflected by the wavy surface of ocean in mirror direction

    Science.gov (United States)

    Zhitkovskiy, Y. Y.; Nosov, A. V.; Savelyev, V. V.

    1985-06-01

    An experimental study was carried out to determine the correlation characteristics of pseudonoise signals reflected from a wave-covered surface in the mirror direction. The major measured quantity was the reciprocal correlation coefficient between the transmitted signal and the reflected signal. The transmitter was lowered from a ship on a 150 m cable. The receiver and preamplifier were lowered to the same depth from a buoy which was allowed to drift from the ship to a distance of 100-500 m, the changing distance changing the angle of the beam reflected from the surface of the ocean back down to the hydrophone. The radiator transmitted a pulsed signal with a pseudonoise carrier. The results were interpreted within the framework of ordinary correlation theory by processing several recordings, calculating the sign and ordinary correlation coefficients to determine the variation in sign correlation coefficient as a function of the ordinary correlation coefficient. Graphs of the average variation are presented. It was found that the medium did not distort the signal as it propagated through the water mass (within the limits of experimental accuracy). The correlation coefficient between the transmitted and reflected signals is thus determined entirely by the characteristics of reradiation of the sound by the wavecovered surface.

  4. Influence of borehole and formation characteristics on elemental standard spectra in geochemical logging

    Science.gov (United States)

    Wu, Wensheng; Yue, Aizhong; Xiang, Wei; Wang, Shusheng; Fan, Dechang

    2017-10-01

    Accurate acquisition of elemental standard spectra is one of the key links in geochemical elemental logging. Because elemental standard spectra are affected by borehole and formation characteristics, it is necessary to study the borehole and formation conditions required for the acquisition of ideal spectra. For these, we constructed a model comprising instruments, borehole and formation; applied the Monte Carlo N-Particle Transport Code to simulate elemental standard spectral responses under different borehole and formation conditions; and performed a comparative analysis of these responses. The results demonstrate that, for the standard capture spectra of an element, a fresh water borehole yields spectra with good statistical properties and significant characteristic peaks. For elements with a high capture cross section and prominent characteristic peaks, a borehole of small diameter yields ideal spectra; conversely, a borehole of slightly larger diameter is suitable for elements with a low capture cross section and insignificant characteristic peaks. A formation containing a certain number of pores full of fresh water can yield better standard spectra except for elements that have a giant capture cross section such as Gd. A formation composed of various compounds of an element yields standard spectra with different effects, which means that an elemental compound has to be selected to get an ideal standard spectrum. For the standard inelastic spectrum of an element, the influence of the borehole fluid or pore fluid should be avoided as much as possible except for oxygen; formations composed of an elementary substance, or chlorides or hydrides of an element yields a better standard spectrum than one composed of its oxides, carbonates or other compounds containing elements with a large inelastic cross section. The compactness of the formation influences the characteristic peaks and statistical properties of the standard spectra. The simulation method takes fully

  5. Influence of pulsed nanosecond volume discharge in atmospheric-pressure air on the electrical characteristics of MCT epitaxial films

    Science.gov (United States)

    Grigoryev, Denis V.; Voitsekhovskii, Alexandr V.; Lozovoy, Kirill A.; Nesmelov, Sergey N.; Dzyadukh, Stanislav M.; Tarasenko, Viktor F.; Shulepov, Michail A.; Dvoretskii, Sergei A.

    2015-12-01

    The purpose of this paper was investigating the effect of volume nanosecond discharge in air at atmospheric pressure on the electro-physical properties of the HgCdTe (MCT) epitaxial films grown by molecular beam epitaxy. Hall measurements of electro-physical parameters of MCT samples after irradiation have shown that there is a layer of epitaxial films exhibiting n-type conductivity that is formed in the near-surface area. After more than 600 pulses of influence parameters and thickness of the resulting n-layer is such that the measured field dependence of Hall coefficient corresponds to the material of n-type conductivity. Also it is shown that the impact of the discharge leads to significant changes in electro-physical characteristics of MIS structures. This fact is demonstrated by increase in density of positive fixed charge, change in the hysteresis type of the capacitance-voltage characteristic, an increase in density of surface states. The preliminary results show that it is possible to use such actions in the development of technologies of the controlled change in the properties of MCT.

  6. Atmospheric teleconnection influence on North American land surface phenology

    Science.gov (United States)

    Dannenberg, Matthew P.; Wise, Erika K.; Janko, Mark; Hwang, Taehee; Kolby Smith, W.

    2018-03-01

    Short-term forecasts of vegetation activity are currently not well constrained due largely to our lack of understanding of coupled climate-vegetation dynamics mediated by complex interactions between atmospheric teleconnection patterns. Using ecoregion-scale estimates of North American vegetation activity inferred from remote sensing (1982-2015), we examined seasonal and spatial relationships between land surface phenology and the atmospheric components of five teleconnection patterns over the tropical Pacific, north Pacific, and north Atlantic. Using a set of regression experiments, we also tested for interactions among these teleconnection patterns and assessed predictability of vegetation activity solely based on knowledge of atmospheric teleconnection indices. Autumn-to-winter composites of the Southern Oscillation Index (SOI) were strongly correlated with start of growing season timing, especially in the Pacific Northwest. The two leading modes of north Pacific variability (the Pacific-North American, PNA, and West Pacific patterns) were significantly correlated with start of growing season timing across much of southern Canada and the upper Great Lakes. Regression models based on these Pacific teleconnections were skillful predictors of spring phenology across an east-west swath of temperate and boreal North America, between 40°N-60°N. While the North Atlantic Oscillation (NAO) was not strongly correlated with start of growing season timing on its own, we found compelling evidence of widespread NAO-SOI and NAO-PNA interaction effects. These results suggest that knowledge of atmospheric conditions over the Pacific and Atlantic Oceans increases the predictability of North American spring phenology. A more robust consideration of the complexity of the atmospheric circulation system, including interactions across multiple ocean basins, is an important step towards accurate forecasts of vegetation activity.

  7. Influence of the shape of soaring particle based on coal-water slurry containing petrochemicals on ignition characteristics

    Directory of Open Access Journals (Sweden)

    Valiullin Timur R.

    2017-01-01

    Full Text Available This paper examines the laws of stable ignition of organic coal-water slurry containing petrochemicals (CWSP. The CWSP is based on the filter cake of coal and scavenge oil. The experiments are performed for individual CWSP particles soaring in a special set-up. The temperature and velocity of an oxidizer flow are varied between 500-1200 K, and 0.5-3 m/s. The dimensions (longitudinal and transverse of particles range are from 0.5 mm to 5 mm. The study indicates how the shape of a fuel particle (sphere, ellipsoid, and polyhedron influences its ignition characteristics (delay time, minimum temperature, modes, stages. Based on the experimental results, the paper explains why the surface configuration of particles influences the conditions of heat transfer with an oxidizer. The results obtained for soaring particles are compared with the results for fixed CWSP particles having different surface configurations (sphere, ellipsoid, and polyhedron. In general, the study may contribute to the expansion of the fuel resource base. The experimental data may be used for the development of the technologies of burning CWSP prepared by recycling traditional fuels. As a result of this study, several recommendations for the practical application of research results are made.

  8. The influence of spherical cavity surface charge distribution on the sequence of partial discharge events

    Energy Technology Data Exchange (ETDEWEB)

    Illias, Hazlee A [Department of Electrical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); Chen, George; Lewin, Paul L, E-mail: h.illias@um.edu.my [Tony Davies High Voltage Laboratory, School of Electronics and Computer Science, University of Southampton, Southampton, SO17 1BJ (United Kingdom)

    2011-06-22

    In this work, a model representing partial discharge (PD) behaviour of a spherical cavity within a homogeneous dielectric material has been developed to study the influence of cavity surface charge distribution on the electric field distribution in both the cavity and the material itself. The charge accumulation on the cavity surface after a PD event and charge movement along the cavity wall under the influence of electric field magnitude and direction has been found to affect the electric field distribution in the whole cavity and in the material. This in turn affects the likelihood of any subsequent PD activity in the cavity and the whole sequence of PD events. The model parameters influencing cavity surface charge distribution can be readily identified; they are the cavity surface conductivity, the inception field and the extinction field. Comparison of measurement and simulation results has been undertaken to validate the model.

  9. The influence of machining condition and cutting tool wear on surface roughness of AISI 4340 steel

    Science.gov (United States)

    Natasha, A. R.; Ghani, J. A.; Che Haron, C. H.; Syarif, J.

    2018-01-01

    Sustainable machining by using cryogenic coolant as the cutting fluid has been proven to enhance some machining outputs. The main objective of the current work was to investigate the influence of machining conditions; dry and cryogenic, as well as the cutting tool wear on the machined surface roughness of AISI 4340 steel. The experimental tests were performed using chemical vapor deposition (CVD) coated carbide inserts. The value of machined surface roughness were measured at 3 cutting intervals; beginning, middle, and end of the cutting based on the readings of the tool flank wear. The results revealed that cryogenic turning had the greatest influence on surface roughness when machined at lower cutting speed and higher feed rate. Meanwhile, the cutting tool wear was also found to influence the surface roughness, either improving it or deteriorating it, based on the severity and the mechanism of the flank wear.

  10. Temporal and spatial distribution characteristics and influencing factors of air quality index in Xuchang

    Science.gov (United States)

    Wang, Zhenghua; Tian, Zhihui

    2018-01-01

    In recent years, the problem of air pollution becomes more and more serious. Based on the geographic and seasonal climatic characteristics of Xuchang City, this paper studies the temporal and spatial distribution characteristics of air quality index. The results show that: from the time point of view, air quality index shows seasonal difference. Air quality index is highest in winter and is lowest in summer. From the space point of view, there are differences between the north and the south to a certain extent. Changge City, Yuzhou city and central Xuchang county is higher than the southeast of Xiangcheng county and Yanling county. The spatial and temporal variation characteristics of air quality index in Xuchang are influenced by natural factors and human activities, and the economic development and population are the important factors affecting the urban air quality.

  11. Influence of stress factors and socio-demographic characteristics on the sleep quality of nursing students

    Directory of Open Access Journals (Sweden)

    Sonia Betzabeth Ticona Benavente

    2014-06-01

    Full Text Available Objective:To analyze the influence of stress factors and socio-demographic characteristics on the sleep quality of nursing students. Method: An analytical cross-sectional and quantitative study, conducted with 151 nursing students in São Paulo between March and April of 2012. A form for socio-demographic characteristics, the Instrument to Evaluate Stress in Nursing Students and the Pittsburgh Sleep Index were applied. Results: High levels of stress was predominant for Time Management (27.8% and Professional Training (30.5% and low sleep quality (78.8%. The Professional Communication, Professional Training and Theoretical Activity are positively correlated to sleep quality. Work activity, academic year and time for daily studies contributed to a low quality of sleep. Conclusion: Few stress factors from the academic environment and some socio-demographic characteristics contributed to the reduction of sleep quality in students.

  12. [Influence of stress factors and socio-demographic characteristics on the sleep quality of nursing students].

    Science.gov (United States)

    Benavente, Sonia Betzabeth Ticona; Silva, Rodrigo Marques da; Higashi, Aline Baraldi; Guido, Laura de Azevedo; Costa, Ana Lucia Siqueira

    2014-06-01

    To analyze the influence of stress factors and socio-demographic characteristics on the sleep quality of nursing students. An analytical cross-sectional and quantitative study, conducted with 151 nursing students in São Paulo between March and April of 2012. A form for socio-demographic characteristics, the Instrument to Evaluate Stress in Nursing Students and the Pittsburgh Sleep Index were applied. High levels of stress was predominant for Time Management (27.8%) and Professional Training (30.5%) and low sleep quality (78.8%). The Professional Communication, Professional Training and Theoretical Activity are positively correlated to sleep quality. Work activity, academic year and time for daily studies contributed to a low quality of sleep. Few stress factors from the academic environment and some socio-demographic characteristics contributed to the reduction of sleep quality in students.

  13. The influence of acceleration loading curve characteristics on traumatic brain injury.

    Science.gov (United States)

    Post, Andrew; Blaine Hoshizaki, T; Gilchrist, Michael D; Brien, Susan; Cusimano, Michael D; Marshall, Shawn

    2014-03-21

    To prevent brain trauma, understanding the mechanism of injury is essential. Once the mechanism of brain injury has been identified, prevention technologies could then be developed to aid in their prevention. The incidence of brain injury is linked to how the kinematics of a brain injury event affects the internal structures of the brain. As a result it is essential that an attempt be made to describe how the characteristics of the linear and rotational acceleration influence specific traumatic brain injury lesions. As a result, the purpose of this study was to examine the influence of the characteristics of linear and rotational acceleration pulses and how they account for the variance in predicting the outcome of TBI lesions, namely contusion, subdural hematoma (SDH), subarachnoid hemorrhage (SAH), and epidural hematoma (EDH) using a principal components analysis (PCA). Monorail impacts were conducted which simulated falls which caused the TBI lesions. From these reconstructions, the characteristics of the linear and rotational acceleration were determined and used for a PCA analysis. The results indicated that peak resultant acceleration variables did not account for any of the variance in predicting TBI lesions. The majority of the variance was accounted for by duration of the resultant and component linear and rotational acceleration. In addition, the components of linear and rotational acceleration characteristics on the x, y, and z axes accounted for the majority of the remainder of the variance after duration. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Study on the characteristics of coal rock electromagnetic radiation (EMR) and the main influencing factors

    Science.gov (United States)

    Song, Xiaoyan; Li, Xuelong; Li, Zhonghui; Zhang, Zhibo; Cheng, Fuqi; Chen, Peng; Liu, Yongjie

    2018-01-01

    Coal rock would produce electromagnetic radiation (EMR) in the loading process, but study on the influence factors influence on the coal rock EMR characteristics in the mesoscopic level is not insufficient. In the paper, the EMR characteristics of coal and rock samples under uniaxial loading are studied. Several typical microcosmic mechanisms affecting the characteristics of EMR are discussed, such as strength, composition and microstructure of the samples. Results show that the macroscopic structure of the outburst coal is soft, the corresponding EMR signal increases slowly with the loading increase and the EMR peak is smaller. The rockburst coal has a strong brittleness, the EMR signal increases quickly and EMR peak appears while the coal breaks is larger than the outburst coal. The EMR characteristics of rock samples are similar to the rockburst coal, but the EMR peak is the largest. When the coal rock microstructure is complete, the coal rock block is larger and the brittleness is stronger, then the corresponding strength would be larger. And the free charge generated by thermal excitation, field emission and intergranular chemical bond breakage would also be more. In the meantime, the crack propagation rate becomes greater, therefore the EMR is more stronger. The piezoelectric effect is mainly caused by the linear elastic stage of the specimen deformation and rupture, which contributes less to the EMR signals. This study is of great theoretical and practical value for assessing the mechanical state of coal rock through EMR technology, and accurately monitoring and predicting the coal rock dynamic disasters.

  15. Numerical study of influence of biofuels on the combustion characteristics and performance of aircraft engine system

    International Nuclear Information System (INIS)

    Zhou, Li; Liu, Zeng-wen; Wang, Zhan-xue

    2015-01-01

    The atomization and combustion flowfield of the combustion chamber with swirl-nozzle were simulated using different biofuels; the thermodynamic cycle of the aircraft engine system were also analyzed, influences of biofuels on the combustion characteristics and performance of aircraft engine system were explored. Results show that viscosity and caloric value are key factors affecting the atomization and combustion characteristics of biofuels, and then dominate the distribution of the temperature and NO concentration. Due to the characteristic of low viscosity and low caloric value for biofuels adopted, the biofuels accumulate near the head of combustion chamber, and the corresponding NO emission is lower than that it has for conventional kerosene. When biofuels with low caloric value are used under the operation condition which is same as the condition for the conventional kerosene, lower turbine inlet temperature, lower thrust and higher specific fuel consumption would be achieved for the aircraft engine. - Highlights: • Influences of biofuels properties on combustion characteristic are explored. • Effects of biofuels on cycle parameters of aircraft engine are discussed. • Viscosity and caloric value are key factors affecting combustion of biofuels. • NO emission becomes lower when biofuels with low caloric value is adopted. • The performance of aircraft engine becomes worse for biofuels with low caloric value.

  16. Which characteristics of nursing home residents relate to factors influencing their dignity?

    Science.gov (United States)

    Oosterveld-Vlug, Mariska G; de Vet, Henrica C W; Pasman, H Roeline W; van Gennip, Isis E; Willems, Dick L; Onwuteaka-Philipsen, Bregje D

    Aim of this study was to explore which characteristics of nursing home residents relate to factors influencing their dignity. Questionnaires containing the Measurement Instrument for Dignity AMsterdam - for Long-Term Care facilities (MIDAM-LTC) were administered to 95 nursing home residents, residing on the general medical wards of six nursing homes in the Netherlands. Associations between residents' characteristics and each MIDAM-LTC item as well as the total number of items considerably influencing dignity were calculated. Results showed that not being optimistic, being male and/or being heavily dependent predispose nursing home residents to have their dignity undermined. Residents with these characteristics should therefore be given special attention in the provision of dignity-conserving care. Age, cultural background, religion, length of stay and socioeconomic status were very rarely related to individual MIDAM-LTC items. Knowledge of associations between characteristics and factors undermining dignity can be used to raise nursing home staff's sensitivity toward these factors. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Influence of micronutrients on rheological characteristics and bread-making quality of flour.

    Science.gov (United States)

    Sudha, M L; Leelavathi, K

    2008-03-01

    Studies were carried out to see the influence of different iron and calcium salts along with some vitamins on the rheological characteristics and bread-making quality of wheat flour. Fortification with iron (30-90 ppm) from different sources showed a marginal increase in water absorption (2%). Calcium ranging between 800 and 1,600 ppm did not show any influence on the mixing properties of the dough. Except for ethylenediamine tetraacetic acid and calcium lactate, all other salts did not have any influence on the alveograph characteristics. The gelatinization temperature slightly increased by about 2-3 degrees C and the cold paste viscosity increased from 468 to 524 BU. Addition of micronutrient premix containing ferrous sulphate, calcium carbonate and vitamins such as thiamine (thiamine hydrochloride), riboflavin, niacin (nicotinic acid) and folic acid at different levels showed a marginal effect on the rheological parameters. There was no significant influence of micronutrient premix on the objective and subjective evaluation of the breads, except for the crumb colour. Fortification with the vitamin-mineral premix did not affect the theological parameters and bread-making quality of flour, even after storage.

  18. Influence of geometric design characteristics on safety under heterogeneous traffic flow

    Directory of Open Access Journals (Sweden)

    Praveen Vayalamkuzhi

    2016-12-01

    Full Text Available This paper focuses on analysing the influence of geometric design characteristics on traffic safety using bi-directional data on a divided roadway operated under heterogeneous traffic conditions in India. The study was carried out on a four lane divided inter-city highway in plain and rolling terrain. Statistical modelling approach by Poisson regression and Negative binomial regression were used to assess the safety performance as occurrence of crashes are random events and to identify the influence of the geometric design variables on the crash frequency. Negative binomial regression model was found to be more suitable to identify the variables contributing to road crashes. The study enabled better understanding of the factors related to road geometrics that influence road crash frequency. The study also established that operating speed has a significant contribution to the total number of crashes. Negative binomial models are found to be appropriate to predict road crashes on divided roadways under heterogeneous traffic conditions.

  19. Influence of snow cover changes on surface radiation and heat balance based on the WRF model

    Science.gov (United States)

    Yu, Lingxue; Liu, Tingxiang; Bu, Kun; Yang, Jiuchun; Chang, Liping; Zhang, Shuwen

    2017-10-01

    The snow cover extent in mid-high latitude areas of the Northern Hemisphere has significantly declined corresponding to the global warming, especially since the 1970s. Snow-climate feedbacks play a critical role in regulating the global radiation balance and influencing surface heat flux exchange. However, the degree to which snow cover changes affect the radiation budget and energy balance on a regional scale and the difference between snow-climate and land use/cover change (LUCC)-climate feedbacks have been rarely studied. In this paper, we selected Heilongjiang Basin, where the snow cover has changed obviously, as our study area and used the WRF model to simulate the influences of snow cover changes on the surface radiation budget and heat balance. In the scenario simulation, the localized surface parameter data improved the accuracy by 10 % compared with the control group. The spatial and temporal analysis of the surface variables showed that the net surface radiation, sensible heat flux, Bowen ratio, temperature and percentage of snow cover were negatively correlated and that the ground heat flux and latent heat flux were positively correlated with the percentage of snow cover. The spatial analysis also showed that a significant relationship existed between the surface variables and land cover types, which was not obviously as that for snow cover changes. Finally, six typical study areas were selected to quantitatively analyse the influence of land cover types beneath the snow cover on heat absorption and transfer, which showed that when the land was snow covered, the conversion of forest to farmland can dramatically influence the net radiation and other surface variables, whereas the snow-free land showed significantly reduced influence. Furthermore, compared with typical land cover changes, e.g., the conversion of forest into farmland, the influence of snow cover changes on net radiation and sensible heat flux were 60 % higher than that of land cover changes

  20. Experimental Study on Triggering Characteristics of a Surface Flashover Triggered Vacuum Switch

    International Nuclear Information System (INIS)

    Yao Xueling; Chen Jingliang; Sun Wei

    2010-01-01

    Triggering characteristics of triggered vacuum switch (TVS), including the discharge delay time, delay jitter, range of operational voltage and peak of pulsed current, are investigated. Both structure and experimental circuit of TVS are presented. The results indicate that TVS, as a surface flashover triggering device with high dielectric permittivity material, is with excellent triggering characteristics. When the hold-off voltage reaches 120 kV, the minimum operational voltage is 1.3 kV, and the minimum discharge delay time and jitter are 100 ns and ±10 ns, respectively. The peak current is up to 240 kA when the operational voltage reaches 100 kV. TVS can well satisfy the main demands of high voltage and current applications, and can also be used under a multi-crowbar circuit.

  1. The Analyses of Turbulence Characteristics in the Atmospheric Surface Layer Using Arbitrary-Order Hilbert Spectra

    Science.gov (United States)

    Wei, W.; Schmitt, F. G.; Huang, Y. X.; Zhang, H. S.

    2016-05-01

    Turbulent characteristics in the atmospheric surface layer are investigated using a data-driven method, Hilbert spectral analysis. The results from empirical mode decomposition display a set of intrinsic mode functions whose characteristic scales suggest a dyadic filter-bank property. It can be concluded from the joint probability density function of the intrinsic mode functions that the turbulent properties are totally different under different stratifications: the amplitudes (or energies) are arranged according to the stability parameter [InlineEquation not available: see fulltext.] for stable conditions, but tend to cluster randomly for unstable cases. The intermittency analyses reveal that second-order Hilbert marginal spectra display a power-law behaviour in the inertial subrange, and that the scaling exponent functions deviate from the theoretical values due to the strong intermittency in the stable boundary layer.

  2. Investigation of game characteristics of elite tennis players on different surfaces.

    Directory of Open Access Journals (Sweden)

    Bülent KİLİT

    2017-03-01

    Full Text Available Aim: The purpose of this study was to investigation of game characteristics of elite tennis players on different surfaces (grass, clay and hard. Material and Methods: As a data collection tool used in the official web pages (www.rolandgarros.com, www.wimbledon.com, www.usopen.org in 2015 Grand Slam tennis tournaments. The study monitored the following game characteristics: 1st service %, aces, double faults, unforced error, winning % on 1st serve, winning % on 2nd serve, winners (including service, average 1st serve speed, average 2nd serve speed, average duration of games, average game number, total match duration, average duration of sets. One way ANOVA and Scheffe post-hoc test was performed in order to evaluate the game characteristics in this study. Results: Wimbledon had a significant more responses in terms of 1st service %, aces, winning % on 1st serve, average 1st and 2nd serve speed in male tennis players (p<0.05. For female tennis players, American open had more double faults, while Wimbledon had more aces, winning % on 1st Serve, winning % on 1st serve, average 1st and 2nd serve speed, winners responses (p<0.05. Conclusion: According to these results, serve values in fast court like Wimbledon were more than the others. Similar game characteristics were seen in French open (slow court and American open (medium court.

  3. Chemical characteristics of fulvic acids from Arctic surface waters: Microbial contributions and photochemical transformations

    Science.gov (United States)

    Cory, Rose M.; McKnight, Diane M.; Chin, Yu-Ping; Miller, Penney; Jaros, Chris L.

    2007-12-01

    Dissolved organic matter (DOM) originating from the extensive Arctic tundra is an important source of organic material to the Arctic Ocean. Chemical characteristics of whole water dissolved organic matter (DOM) and the fulvic acid fraction of DOM were studied from nine surface waters in the Arctic region of Alaska to gain insight into the extent of microbial and photochemical transformation of this DOM. All the fulvic acids had a strong terrestrial/higher plant signature, with uniformly depleted δ13C values of -28‰, and low fluorescence indices around 1.3. Several of the measured chemical characteristics of the Arctic fulvic acids were related to water residence time, a measure of environmental exposure to sunlight and microbial activity. For example, fulvic acids from Arctic streams had higher aromatic contents, higher specific absorbance values, lower nitrogen content, lower amino acid-like fluorescence and were more depleted in δ15N relative to fulvic acids isolated from lake and coastal surface waters. The differences in the nitrogen signature between the lake and coastal fulvic acids compared to the stream fulvic acids indicated that microbial contributions to the fulvic acid pool increased with increasing water residence time. The photo-lability of the fulvic acids was positively correlated with water residence time, suggesting that the fulvic acids isolated from source waters with larger water residence times (i.e., lakes and coastal waters) have experienced greater photochemical degradation than the stream fulvic acids. In addition, many of the initial differences in fulvic acid chemical characteristics across the gradient of water residence times were consistent with changes observed in fulvic acid photolysis experiments. Taken together, results from this study suggest that photochemical processes predominantly control the chemical character of fulvic acids in Arctic surface waters. Our findings show that hydrologic transport in addition to

  4. Influence of surface free energy of denture base and liner materials on Candida albicans biofilms.

    Science.gov (United States)

    da Silva, Wander J; Leal, Cristiane Maria B; Viu, Flávia C; Gonçalves, Letícia M; Barbosa, Célia Marisa R; Del Bel Cury, Altair A

    2015-05-01

    This study aimed to evaluate the influence of surface free energy (SFE) of denture base and liner materials on Candida albicans biofilm development. Discs were fabricated using poly(methyl methacrylate) acrylic resin and poly(ethyl methacrylate) denture liner, according to the manufacturers' instructions. For SFE test, discs were pellicle-coated with saliva alone, saliva + blood plasma, or blood plasma alone. Candida albicans biofilms were allowed to form on pellicle-coated discs for 48 h. Biofilms were evaluated for cell counts, metabolic activity, and structural characteristics at adhesion phase (after 1.5 h of development) and at biofilm maturity (after 48 h of development). Data were analyzed by anova and Tukey tests using a significance level of 5%. Saliva + blood plasma pellicles had a higher SFE compared to pellicles of saliva or blood plasma alone (P  0.05). In contrast, the presence of blood plasma resulted in higher cell counts, biovolume, and thickness of mature biofilms on both materials (P < 0.001). Increases in SFE from pellicle-coating leads to robust mature C. albicans biofilms on both denture materials. © 2014 Wiley Publishing Asia Pty Ltd.

  5. Influence of steam generator surface state on corrosion and oxide formation

    International Nuclear Information System (INIS)

    Mazenc, Arnaud; Leclercq, Stephanie; Seyeux, Antoine; Galtayries, Anouk; Marcus, Philippe

    2012-09-01

    The corrosion and release of nickel-based alloy Steam Generator tubes are partly due to their surface state. Among the most important parameters influencing the corrosion, the effect of grain size and the effect of grain crystallographic orientation have been chosen to be studied. The aim of this study is to determine how these parameters have an impact on the corrosion of Steam Generator tubes. Thermal treatments (700 deg. C and 1050 deg. C) have been performed on several samples in Alloy 690 to obtain homogeneous grain sizes, varying from 25 μm to 110 μm. Two samples have been oxidised for four days in a recirculating autoclave, reproducing primary conditions. The changes of oxide composition and thickness were examined by ToF-SIMS on samples exposed to primary water conditions. The intensity profiles versus thicknesses of characteristic oxide anions, such as CrO - , NiO - or FeO - enable us to evaluate the effect of grain size and crystallographic orientation on the formation of an enriched inner chromium layer. As regards to the grain size, there was no effect on the growth, but smaller grains led to a chromium-rich oxide layer. The effect of crystallographic orientation was observed on the oxidation kinetics and the composition of oxide scales. (authors)

  6. Doppler lidar investigation of wind turbine wake characteristics and atmospheric turbulence under different surface roughness.

    Science.gov (United States)

    Zhai, Xiaochun; Wu, Songhua; Liu, Bingyi

    2017-06-12

    Four field experiments based on Pulsed Coherent Doppler Lidar with different surface roughness have been carried out in 2013-2015 to study the turbulent wind field in the vicinity of operating wind turbine in the onshore and offshore wind parks. The turbulence characteristics in ambient atmosphere and wake area was analyzed using transverse structure function based on Plane Position Indicator scanning mode. An automatic wake processing procedure was developed to determine the wake velocity deficit by considering the effect of ambient velocity disturbance and wake meandering with the mean wind direction. It is found that the turbine wake obviously enhances the atmospheric turbulence mixing, and the difference in the correlation of turbulence parameters under different surface roughness is significant. The dependence of wake parameters including the wake velocity deficit and wake length on wind velocity and turbulence intensity are analyzed and compared with other studies, which validates the empirical model and simulation of a turbine wake for various atmosphere conditions.

  7. Tree-shaped fractal meta-surface with left-handed characteristics for absorption application

    Science.gov (United States)

    Faruque, M. R. I.; Hasan, M. M.; Islam, M. T.

    2018-02-01

    A tri-band fractal meta-surface absorber composed of metallic branches of a tree connected with a straight metal strip has been presented in this paper for high absorption application. The proposed tree-shaped structure shows resonance in C-, X-, and Ku-bands and left-handed characteristics in 14.15 GHz. The dimension of the tree-shaped meta-surface single unit cell structure is 9 × 9 mm2 and the effective medium ratio is 5.50. In addition, the designed absorber structure shows absorption above 84%, whereas the absorber structure printed on epoxy resin fiber substrate material. The FIT-based CST-MWS has been utilized for the design, simulation, and analysis purposes. Fabrication is also done for the experimental validation.

  8. Understanding Changes in Modeled Land Surface Characteristics Prior to Lightning-Initiated Holdover Fire Breakout

    Science.gov (United States)

    Schultz, Christopher J.; Case, Jonathan L.; Hain, Christopher R.; White, Kristopher; Wachter, J. Brent; Nauslar, Nicholas; MacNamara, Brittany

    2018-01-01

    Lightning initiated wildfires are only 16% of the total number of wildfires within the United States, but account for 56% of the acreage burned. One of the challenges with lightning-initiated wildfires is their ability to "holdover" which means smolder for up to 2+ weeks before breaking out into a full fledged fire. This work helps characterize the percentage of holdover events due to lightning, and helps quantify changes in the land surface characteristics to help understand trends in soil moisture and vegetation stress that potentially contribute to the fire breaking out into a full wildfire.

  9. A Modelling Method of Bolt Joints Based on Basic Characteristic Parameters of Joint Surfaces

    Science.gov (United States)

    Yuansheng, Li; Guangpeng, Zhang; Zhen, Zhang; Ping, Wang

    2018-02-01

    Bolt joints are common in machine tools and have a direct impact on the overall performance of the tools. Therefore, the understanding of bolt joint characteristics is essential for improving machine design and assembly. Firstly, According to the experimental data obtained from the experiment, the stiffness curve formula was fitted. Secondly, a finite element model of unit bolt joints such as bolt flange joints, bolt head joints, and thread joints was constructed, and lastly the stiffness parameters of joint surfaces were implemented in the model by the secondary development of ABAQUS. The finite element model of the bolt joint established by this method can simulate the contact state very well.

  10. Spectral-Modulation Characteristics of Vertical-Cavity Surface-Emitting Lasers

    Science.gov (United States)

    Vas'kovskaya, M. I.; Vasil'ev, V. V.; Zibrov, S. A.; Yakovlev, V. P.; Velichanskii, V. L.

    2018-01-01

    The requirements imposed on vertical-cavity surface-emitting lasers in a number of metrological problems in which optical pumping of alkali atoms is used are considered. For lasers produced by different manufacturers, these requirements are compared with the experimentally observed spectral characteristics at a constant pump current and in the microwave modulation mode. It is shown that a comparatively small number of lasers in the microwave modulation mode make it possible to obtain the spectrum required for atomic clocks based on the coherent population-trapping effect.

  11. Influence of the spectral distribution of light on the characteristics of photovoltaic panel. Comparison between simulation and experimental

    Science.gov (United States)

    Chadel, Meriem; Bouzaki, Mohammed Moustafa; Chadel, Asma; Petit, Pierre; Sawicki, Jean-Paul; Aillerie, Michel; Benyoucef, Boumediene

    2017-02-01

    We present and analyze experimental results obtained with a laboratory setup based on a hardware and smart instrumentation for the complete study of performance of PV panels using for illumination an artificial radiation source (Halogen lamps). Associated to an accurate analysis, this global experimental procedure allows the determination of effective performance under standard conditions thanks to a simulation process originally developed under Matlab software environment. The uniformity of the irradiated surface was checked by simulation of the light field. We studied the response of standard commercial photovoltaic panels under enlightenment measured by a spectrometer with different spectra for two sources, halogen lamps and sunlight. Then, we bring a special attention to the influence of the spectral distribution of light on the characteristics of photovoltaic panel, that we have performed as a function of temperature and for different illuminations with dedicated measurements and studies of the open circuit voltage and short-circuit current.

  12. Surface modification of TiO2 nanoparticles via photocataliticaly induced reaction: Influence of functionality of silane coupling agent

    International Nuclear Information System (INIS)

    Tomovska, Radmila; Daniloska, Vesna; Asua, Jose M.

    2013-01-01

    Highlights: ► TiO 2 nanoparticles were modified by photocatalytic induced surface reaction. ► TiO 2 nanoparticles were subjects of modification and catalysts for the reaction. ► No cleavage of Si-C bond in silane coupling agent 3-triethoxysilyl propyl isocianate. ► High influence of functional group in silane on the Si-C cleavage was determined. ► Different electronegativity of the functionalities in the silane determines reaction way. - Abstract: In the present work the surface modification of TiO 2 nanoparticles by photocatalyticaly induced reaction with silane coupling agent 3-triethoxysilyl propyl isocianate (PIC) has been presented. It was demonstrated establishing of covalent Ti-O-Si bond between the nanoparticles and the PIC molecule. In comparison with previous results, it was demonstrated the high influence of the functional group from the silane coupling agent on the reaction course during surface functionalziation of TiO 2 nanoparticles. Depending on the amount and type (electronegativity of the end-functionalities) of the silane compound, high control of the surface characteristics of TiO 2 nanoparticles could be achieved.

  13. Influence of manufacturing processes on cell surface properties of probiotic strain Lactobacillus rhamnosus Lcr35®.

    Science.gov (United States)

    Nivoliez, Adrien; Veisseire, Philippe; Alaterre, Elina; Dausset, Caroline; Baptiste, Fabrice; Camarès, Olivier; Paquet-Gachinat, Marylise; Bonnet, Muriel; Forestier, Christiane; Bornes, Stéphanie

    2015-01-01

    The influence of the industrial process on the properties of probiotics, administered as complex manufactured products, has been poorly investigated. In the present study, we comparatively assessed the cell wall characteristics of the probiotic strain Lactobacillus rhamnosus Lcr35® together with three of its commercial formulations with intestinal applications. Putative secreted and transmembrane-protein-encoding genes were initially searched in silico in the genome of L. rhamnosus Lcr35®. A total of 369 candidate genes were identified which expressions were followed using a custom Lactobacillus DNA chip. Among them, 60 or 67 genes had their expression either upregulated or downregulated in the Lcr Restituo® packet or capsule formulations, compared to the native Lcr35® strain. Moreover, our data showed that the probiotic formulations (Lcr Lenio®, Lcr restituo® capsule and packet) showed a better capacity to adhere to intestinal epithelial Caco-2 cells than the native Lcr35® strain. Microbial (MATS) tests showed that the probiotic was an electron donor and that they were more hydrophilic than the native strain. The enhanced adhesion capacity of the active pharmaceutical ingredients (APIs) to epithelial Caco-2 cells and their antipathogen effect could be due to this greater surface hydrophilic character. These findings suggest that the manufacturing process influences the protein composition and the chemical properties of the cell wall. It is therefore likely that the antipathogen effect of the formulation is modulated by the industrial process. Screening of the manufactured products' properties would therefore represent an essential step in evaluating the effects of probiotic strains.

  14. Influence of viscoelastic property on laser-generated surface acoustic waves in coating-substrate systems

    International Nuclear Information System (INIS)

    Sun Hongxiang; Zhang Shuyi; Xu Baiqiang

    2011-01-01

    Taking account of the viscoelasticity of materials, the pulsed laser generation of surface acoustic waves in coating-substrate systems has been investigated quantitatively by using the finite element method. The displacement spectra of the surface acoustic waves have been calculated in frequency domain for different coating-substrate systems, in which the viscoelastic properties of the coatings and substrates are considered separately. Meanwhile, the temporal displacement waveforms have been obtained by applying inverse fast Fourier transforms. The numerical results of the normal surface displacements are presented for different configurations: a single plate, a slow coating on a fast substrate, and a fast coating on a slow substrate. The influences of the viscoelastic properties of the coating and the substrate on the attenuation of the surface acoustic waves have been studied. In addition, the influence of the coating thickness on the attenuation of the surface acoustic waves has been also investigated in detail.

  15. Assessment of the dimensions and surface characteristics of orthodontic wires and bracket slots

    Directory of Open Access Journals (Sweden)

    Gabriel Schmidt Dolci

    2013-04-01

    Full Text Available OBJECTIVE: The purpose of this study was to evaluate the dimensions and surface characteristics of orthodontic wires and bracket slots of different commercial brands. METHODS: Thirty metallic brackets (0.022 x 0.028-in and 0.022 x 0.030-in were divided in three groups: DYN/3M group = Dyna-Lock, 3M/Unitek (stainless steel, or SS; STD/MO group = Slim Morelli (SS; and Ni-Free/MO group = Slim Morelli (Ni-Free. The stainless steel wires (0.019 x 0.025in were divided into two groups: MO group = Morelli; and 3M group = 3M/Unitek. The bracket and wire measurements were done by two methods: (a Surface Electron Microscopy (SEM, and (b Profile projection. The surface analysis was done qualitatively, based on SEM images and/or by a rugosimeter. The quantitative results were analyzed by ANOVA with Tukey's test (p < 0.05 and Student's t test. RESULTS: A significant difference in the dimensions of slots was observed, and the NiFree/MO group showed the greatest changes when compared to the other groups. The analysis of surface topography of the brackets indicated greater homogeneity of the metallic matrix for DYN/3M and STD/MO groups. As for the dimensions of the wires, groups showed statistically different mean heights. CONCLUSIONS: It was concluded that wires and brackets slots can present altered dimensions, which might directly and unintentionally affect the planned tooth movement.

  16. Adhesion strength and spreading characteristics of EPS on membrane surfaces during lateral and central growth.

    Science.gov (United States)

    Tansel, Berrin; Tansel, Derya Z

    2013-11-01

    Deposition of extracellular polymeric substances (EPS) on membrane surfaces is a precursor step for bacterial attachment. The purpose of this study was to analyze the morphological changes on a clean polysulfone ultrafilration membrane after exposure to effluent from a membrane bioreactor. The effluent was filtered to remove bacteria before exposing the membrane. The morphological characterization was performed by atomic force microscopy (AFM). The lateral (2D) and central growth characteristics (3D) of the EPS deposits were evaluated by section and topographical analyses of the height images. The contact angle of single EPS units was 9.07 ± 0.50° which increased to 24.41 ± 1.00° for large clusters (over 10 units) and decreased to 18.68 ± 1.00° for the multilayered clusters. The surface tension of the single EPS units was 49.34 ± 1.70 mNm(-1). The surface tension of single layered small and large EPS clusters were 51.26 ± 2.05 and 53.48 ± 2.01 mNm(-1), respectively. For the multilayered clusters, the surface tension was 51.43 ± 2.05 mNm(-1). The spreading values were negative for all deposits on the polysulfone membrane indicating that the EPS clusters did not have tendency to spread but preferred to retain their shapes. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Surface and magnetic characteristics of Ni-Mn-Ga/Si (100) thin film

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S. Vinodh; Pandyan, R. Kodi; Mahendran, M., E-mail: manickam-mahendran@tce.edu, E-mail: perialangulam@gmail.com [Smart Materials Lab, Department of Physics, Thiagarajar College of Engineering, Madurai – 625 015 (India); Raja, M. Manivel [Defence Metallurgical Research Laboratory, Hyderabad – 500 058 (India); Pandi, R. Senthur [School of Advanced Sciences, VIT University, Vellore – 632 014 (India)

    2016-05-23

    Polycrystalline Ni-Mn-Ga thin films have been deposited on Si (100) substrate with different film thickness. The influence of film thickness on the phase structure and magnetic domain of the films has been examined by scanning electron microscope, atomic force microscopy and magnetic force microscopy. Analysis of structural parameters indicates that the film at lower thickness exhibits the coexistence of both austenite and martensite phase, whereas at higher thickness L1{sub 2} cubic non magnetic phase is noticed. The grains size and the surface roughness increase along with the film thickness and attain the maximum of 45 nm and 34.96 nm, respectively. At lower film thickness, the magnetic stripe domain is found like maze pattern with dark and bright images, while at higher thickness the absence of stripe domains is observed. The magnetic results reveal that the films strongly depend on their phase structure and microstructure which influence by the film thickness.

  18. Modification of titanium alloys surface properties by plasma electrolytic oxidation (PEO) and influence on biological response.

    Science.gov (United States)

    Echeverry-Rendón, Mónica; Galvis, Oscar; Aguirre, Robinson; Robledo, Sara; Castaño, Juan Guillermo; Echeverría, Félix

    2017-09-27

    Surface characteristics can mediate biological interaction improving or affecting the tissue integration after implantation of a biomaterial. Features such as topography, wettability, surface energy and chemistry can be key determinants for interactions between cells and materials. Plasma electrolytic oxidation (PEO) is a technique used to control this kind of parameters by the addition of chemical species and the production of different morphologies on the surfaces of titanium and its alloys. With the purpose to improve the biological response, surfaces of c.p titanium and Ti6Al4V were modified by using PEO. Different electrolytes, voltages, current densities and anodizing times were tested in order to obtain surfaces with different characteristics. The obtained materials were characterized by different techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM) and glow discharge optical emission spectroscopy (GDOES). Wettability of the obtained surfaces were measured and the corresponding surface energies were calculated. Superhydrophilic surfaces with contact angles of about 0 degrees were obtained without any other treatment but PEO and this condition in some cases remains stable after several weeks of anodizing; crystal phase composition (anatase-rutile) of the anodic surface appears to be critical for obtaining this property. Finally, in order to verify the biological effect of these surfaces, osteoblast were seeded on the samples. It was found that cell behavior improves as SFE (surface free energy) and coating porosity increases whereas it is affected negatively by roughness. Techniques for surface modification allow changes in the coatings such as surface energy, roughness and porosity. As a consequence of this, biological response can be altered. In this paper, surfaces of c.p Ti and Ti6Al4V were modified by using plasma electrolytic oxidation (PEO) in order to accelerate the cell adhesion process.

  19. Influence of ultrasound probe treatment time and protease type on functional and physicochemical characteristics of egg white protein hydrolysates.

    Science.gov (United States)

    Stefanovic, Andrea B; Jovanovic, Jelena R; Balanc, Bojana D; Šekuljica, Nataša Ž; Tanaskovic, Sonja M Jakovetic; Dojcinovic, Marina B; Kneževic-Jugovic, Zorica D

    2018-03-05

    The objective of this study was to discover the relationship between the ultrasound probe treatment (UPT) on egg white proteins (EWPs) before EWPs hydrolysis by different proteases, and the functional properties of the obtained hydrolysates. To fulfill this goal, the protein solubility, foaming, and emulsifying properties were studied as a function of the UPT time and then related to the surface characteristics and structural properties. The changes in the hydrolysates microstructures and macromolecular conformation, induced by the UPT, were followed using scanning electron microscope analyzis (SEM) and Fourier transforms infrared spectroscopy (FTIR). The results showed that UPT influenced (P < 0.05) the proteolysis of egg white proteins for all examined treatment times. Alcalase hydrolysates (AHs) and papain hydrolysates (PHs) were found to have a higher solubility, as a consequence of their relatively higher foaming, and emulsifying properties compared to the untreated hydrolysates. The changes in surface hydrophobicity, sulfhydryl content and surface charge of AHs and PHs indicated unfolding of EWPs affected by ultrasound. SEM analyzis showed that UPT destroyed the microstructures of AHs and PHs, while FTIR spectra indicated remarkable changes in the macromolecular conformation of AHs and PHs after UPT. This study revealed that by combining ultrasound pre-hydrolysis treatment under controlled conditions with thoughtful proteases selection, hydrolysates with improved functional properties could be produced, enhancing utilization of EWPs in food products.

  20. Effects of surface characteristics on the plantar shape of feet and subjects' perceived sensations.

    Science.gov (United States)

    Witana, Channa P; Goonetilleke, Ravindra S; Xiong, Shuping; Au, Emily Y L

    2009-03-01

    Orthotics and other types of shoe inserts are primarily designed to reduce injury and improve comfort. The interaction between the plantar surface of the foot and the load-bearing surface contributes to foot and surface deformations and hence to perceived comfort, discomfort or pain. The plantar shapes of 16 participants' feet were captured when standing on three support surfaces that had different cushioning properties in the mid-foot region. Foot shape deformations were quantified using 3D laser scans. A questionnaire was used to evaluate the participant's perceptions of perceived shape and perceived feeling. The results showed that the structure in the mid-foot could change shape, independent of the rear-foot and forefoot regions. Participants were capable of identifying the shape changes with distinct preferences towards certain shapes. The cushioning properties of the mid-foot materials also have a direct influence on perceived feelings. This research has strong implications for the design and material selection of orthotics, insoles and footwear.

  1. Hydrochemical characteristics and water quality assessment of surface water and groundwater in Songnen plain, Northeast China.

    Science.gov (United States)

    Zhang, Bing; Song, Xianfang; Zhang, Yinghua; Han, Dongmei; Tang, Changyuan; Yu, Yilei; Ma, Ying

    2012-05-15

    Water quality is the critical factor that influence on human health and quantity and quality of grain production in semi-humid and semi-arid area. Songnen plain is one of the grain bases in China, as well as one of the three major distribution regions of soda saline-alkali soil in the world. To assess the water quality, surface water and groundwater were sampled and analyzed by fuzzy membership analysis and multivariate statistics. The surface water were gather into class I, IV and V, while groundwater were grouped as class I, II, III and V by fuzzy membership analysis. The water samples were grouped into four categories according to irrigation water quality assessment diagrams of USDA. Most water samples distributed in category C1-S1, C2-S2 and C3-S3. Three groups were generated from hierarchical cluster analysis. Four principal components were extracted from principal component analysis. The indicators to water quality assessment were Na, HCO(3), NO(3), Fe, Mn and EC from principal component analysis. We conclude that surface water and shallow groundwater are suitable for irrigation, the reservoir and deep groundwater in upstream are the resources for drinking. The water for drinking should remove of the naturally occurring ions of Fe and Mn. The control of sodium and salinity hazard is required for irrigation. The integrated management of surface water and groundwater for drinking and irrigation is to solve the water issues. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Influence of carbon monoxide to the surface layer of uranium metal and its oxides

    International Nuclear Information System (INIS)

    Wang Xiaoling; Fu Yibei; Xie Renshou; Huang Ruiliang

    1996-09-01

    The surface structures of uranium metal and triuranium octaoxide (U 3 O 8 ) and the influence of carbon monoxide to the surface layers have been studied by X-ray photoelectron spectroscopy (XPS). After exposure to carbon monoxide, contents of oxygen in the surface oxides of uranium metal and U 3 O 8 are decreased and O/U ratios decrease 7.2%, 8.0% respectively. The investigation indicated the surface layers of uranium metal and its oxides were forbidden to further oxidation in the atmosphere of carbon monoxide. (11 refs., 9 figs., 2 tabs.)

  3. Surface deformation and friction characteristic of nano scratch at ductile-removal regime for optical glass BK7.

    Science.gov (United States)

    Li, Chen; Zhang, Feihu; Ding, Ye; Liu, Lifei

    2016-08-20

    Nano scratch for optical glass BK7 based on the ductile-removal regime was carried out, and the influence rule of scratch parameters on surface deformation and friction characteristic was analyzed. Experimental results showed that, with increase of normal force, the deformation of burrs in the edge of the scratch was more obvious, and with increase of the scratch velocity, the deformation of micro-fracture and burrs in the edge of the scratch was more obvious similarly. The residual depth of the scratch was measured by atomic force microscope. The experimental results also showed that, with increase of normal force, the residual depth of the scratch increased linearly while the elastic recovery rate decreased. Furthermore, with increase of scratch velocity, the residual depth of the scratch decreased while the elastic recovery rate increased. The scratch process of the Berkovich indenter was divided into the cutting process of many large negative rake faces based on the improved cutting model, and the friction characteristic of the Berkovich indenter and the workpiece was analyzed. The analysis showed that the coefficient of friction increased and then tended to be stable with the increase of normal force. Meanwhile, the coefficient of friction decreased with the increase of scratch velocity, and the coefficients, k ln(v) and μ0, were introduced to improve the original formula of friction coefficient.

  4. Spectral reflectance characteristics of different snow and snow-covered land surface objects and mixed spectrum fitting

    Science.gov (United States)

    Zhang, J.-H.; Zhou, Z.-M.; Wang, P.-J.; Yao, F.-M.; Yang, L.

    2011-01-01

    The field spectroradiometer was used to measure spectra of different snow and snow-covered land surface objects in Beijing area. The result showed that for a pure snow spectrum, the snow reflectance peaks appeared from visible to 800 nm band locations; there was an obvious absorption valley of snow spectrum near 1030 nm wavelength. Compared with fresh snow, the reflection peaks of the old snow and melting snow showed different degrees of decline in the ranges of 300~1300, 1700~1800 and 2200~2300 nm, the lowest was from the compacted snow and frozen ice. For the vegetation and snow mixed spectral characteristics, it was indicated that the spectral reflectance increased for the snow-covered land types(including pine leaf with snow and pine leaf on snow background), due to the influence of snow background in the range of 350~1300 nm. However, the spectrum reflectance of mixed pixel remained a vegetation spectral characteristic. In the end, based on the spectrum analysis of snow, vegetation, and mixed snow/vegetation pixels, the mixed spectral fitting equations were established, and the results showed that there was good correlation between spectral curves by simulation fitting and observed ones(correlation coefficient R2=0.9509).

  5. Influence of feedback characteristics on perceived learning value of feedback in clerkships: does culture matter?

    Science.gov (United States)

    Suhoyo, Yoyo; Van Hell, Elisabeth A; Kerdijk, Wouter; Emilia, Ova; Schönrock-Adema, Johanna; Kuks, Jan B M; Cohen-Schotanus, Janke

    2017-04-05

    Various feedback characteristics have been suggested to positively influence student learning. It is not clear how these feedback characteristics contribute to students' perceived learning value of feedback in cultures classified low on the cultural dimension of individualism and high on power distance. This study was conducted to validate the influence of five feedback characteristics on students' perceived learning value of feedback in an Indonesian clerkship context. We asked clerks in Neurology (n = 169) and Internal Medicine (n = 132) to assess on a 5-point Likert scale the learning value of the feedback they received. We asked them to record whether the feedback provider (1) informed the student what went well, (2) mentioned which aspects of performance needed improvement, (3) compared the student's performance to a standard, (4) further explained or demonstrated the correct performance, and (5) prepared an action plan with the student to improve performance. Data were analyzed using multilevel regression. A total of 250 students participated in this study, 131 from Internal Medicine (response rate 99%) and 119 from Neurology (response rate 70%). Of these participants, 225 respondents (44% males, 56% females) completed the form and reported 889 feedback moments. Students perceived feedback as more valuable when the feedback provider mentioned their weaknesses (β = 0.153, p perceived learning value of feedback. No gender differences were found for perceived learning value. In Indonesia, we could validate four out of the five characteristics for effective feedback. We argue that our findings relate to culture, in particular to the levels of individualism and power distance. The recognized characteristics of what constitutes effective feedback should be validated across cultures.

  6. Do coder characteristics influence validity of ICD-10 hospital discharge data?

    Directory of Open Access Journals (Sweden)

    Beck Cynthia A

    2010-04-01

    Full Text Available Abstract Background Administrative data are widely used to study health systems and make important health policy decisions. Yet little is known about the influence of coder characteristics on administrative data validity in these studies. Our goal was to describe the relationship between several measures of validity in coded hospital discharge data and 1 coders' volume of coding (≥13,000 vs. Methods This descriptive study examined 6 indicators of face validity in ICD-10 coded discharge records from 4 hospitals in Calgary, Canada between April 2002 and March 2007. Specifically, mean number of coded diagnoses, procedures, complications, Z-codes, and codes ending in 8 or 9 were compared by coding volume and employment status, as well as hospital type. The mean number of diagnoses was also compared across coder characteristics for 6 major conditions of varying complexity. Next, kappa statistics were computed to assess agreement between discharge data and linked chart data reabstracted by nursing chart reviewers. Kappas were compared across coder characteristics. Results 422,618 discharge records were coded by 59 coders during the study period. The mean number of diagnoses per record decreased from 5.2 in 2002/2003 to 3.9 in 2006/2007, while the number of records coded annually increased from 69,613 to 102,842. Coders at the tertiary hospital coded the most diagnoses (5.0 compared with 3.9 and 3.8 at other sites. There was no variation by coder or site characteristics for any other face validity indicator. The mean number of diagnoses increased from 1.5 to 7.9 with increasing complexity of the major diagnosis, but did not vary with coder characteristics. Agreement (kappa between coded data and chart review did not show any consistent pattern with respect to coder characteristics. Conclusions This large study suggests that coder characteristics do not influence the validity of hospital discharge data. Other jurisdictions might benefit from

  7. Importance of surface characteristics of QUARTZ DQ 12 for acute inflammation

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, C.; Becher, A.; Scins, R.P.F.; Hoehr, D.; Unfried, K.; Knaapen, A.M.; Borm, P.J.A. [Institut fuer medizinische Forschung (IUF), Duesseldorf (Germany)

    2004-07-01

    Although quartz is known to induce inflammation in rat lungs, mechanisms are not yet fully understood. The importance of particle surface characteristics was investigated in vivo after intratracheal instillation of different preparations of quartz in rat lungs. Three days after instillation of 2 mg DQ12 quartz, or DQ12 coated with polyvinylpyridine-N-oxide (PVNO) or Aluminium lactate (AL), lungs of female Wistar rats were lavaged in situ to determine markers of inflammation. Control rats received saline or the coating substances alone. DQ12 induced a marked inflammatory response, as indicated by a significant increase in the number of neutrophils and macrophages, as well as in the levels of b-glucuronidase and myeloperoxidase. None of these inflammatory markers was increased for both coated quartz preparations, with the exception of neutrophil influx which was also increased after treatment with AL quartz. Our results indicate that surface characteristics are important in the onset of quartz-induced lung inflammation which could imply a different development of persistent inflammation. This will be investigated in later follow-up time points of the same animal study. (orig.)

  8. Significance of frost action and surface soil characteristics to wind erosion at Rocky Flats, Colorado. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Caine, N.

    1978-09-01

    This study of the potential links between soil freezing and wind erosion was conducted at Rocky Flats during 4 winters. Most of the study has involved the conditions leading to the growth of segregation ice in the surface soil and the ground heave which that produces. This occurs about 15 times in the average winter at Rocky Flats, always on a diurnal cycle. Such frost action is preferentially distributed in time and space and cannot be estimated from air temperatures alone. November and March are the months of most frequent frost heave, and then only in the days following precipitation or snowmelt. The most marked frost effects are found on exposed interfluve and hillcrest situations, where there are patches of bare soil. Almost no effects are found on the valley floors. Soil disturbance by segregation ice leads to a marked decrease in soil bulk density, and presumably in soil strength though this change has not been quantitatively defined. However, this does not lead to wind erosion of the soil at the study site because that surface is more influenced by the vegetation cover than by the soil characteristics.

  9. Influence of surface roughness on the corrosion behaviour of magnesium alloy

    International Nuclear Information System (INIS)

    Walter, R.; Kannan, M. Bobby

    2011-01-01

    Research highlights: → Surface roughness of AZ91 magnesium alloy plays a critical role in the passivation behaviour of the alloy. → The passivation behaviour of the alloy influences the pitting tendency. → Increase in surface roughness of AZ91 magnesium alloy increases the pitting tendency of the alloy. -- Abstract: In this study, the influence of surface roughness on the passivation and pitting corrosion behaviour of AZ91 magnesium alloy in chloride-containing environment was examined using electrochemical techniques. Potentiodynamic polarisation and electrochemical impedance spectroscopy tests suggested that the passivation behaviour of the alloy was affected by increasing the surface roughness. Consequently, the corrosion current and the pitting tendency of the alloy also increased with increase in the surface roughness. Scanning electron micrographs of 24 h immersion test samples clearly revealed pitting corrosion in the highest surface roughness (Sa 430) alloy, whereas in the lowest surface roughness (Sa 80) alloy no evidence of pitting corrosion was observed. Interestingly, when the passivity of the alloy was disturbed by galvanostatically holding the sample at anodic current for 1 h, the alloy underwent high pitting corrosion irrespective of their surface roughness. Thus the study suggests that the surface roughness plays a critical role in the passivation behaviour of the alloy and hence the pitting tendency.

  10. Influences of surface hydrophilicity on frost formation on a vertical cold plate under natural convection conditions

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zhongliang; Zhang, Xinghua; Wang, Hongyan; Meng, Sheng; Cheng, Shuiyuan [Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education and Key Laboratory of Heat Transfer and Energy Conversion, Beijing Education Commission, College of Environmental and Energy Engineering, Beijing University of Technology, Pingleyuan 100, Beijing 100022 (China)

    2007-07-15

    Surface hydrophilicity has a strong influence on frost nucleation according to phase transition theory. To study this effect, a close observation of frost formation and deposition processes on a vertical plate was made under free convection conditions. The formation and shape variation of frost crystals during the initial period are described and the frost thickness variation with time on both hydrophobic and plain copper cold surfaces are presented. The various influencing factors are discussed in depth. The mechanism of surface hydrophilicity influence on frost formation was analyzed theoretically. This revealed that increasing the contact angle can increase the potential barrier and restrain crystal nucleation and growth and thus frost deposition. The experimental results show that the initial water drops formed on a hydrophobic surface are smaller and remain in the liquid state for a longer time compared with ones formed on a plain copper surface. It is also observed that the frost layer deposited on a hydrophobic surface is loose and weak. Though the hydrophobic surface can retard frost formation to a certain extent and causes a looser frost layer, our experimental results show that it does not depress the growth of the frost layer. (author)

  11. Influence of heat treatment on physicochemical and rheological characteristics of natural yogurts

    Directory of Open Access Journals (Sweden)

    Juliana Aparecida Célia

    2017-08-01

    Full Text Available The aim of this study was to assess the influence of heat treatment on physicochemical and rheological characteristics of natural yogurts, as well as the influence of lyophilization process on natural yogurts after reconstitution. In the first experiment, three yogurt treatments were processed, as follows: Treatment 1, yogurt produced with raw refrigerated milk; Treatment 2, yogurt produced with refrigerated pasteurized milk; and Treatment 3, yogurt produced with UHT (ultra-high temperature milk, in addition to analyses of fat, protein, moisture, titratable acidity, and pH. The shelf life of yogurts at 1, 8, 15, 22, and 29 days of storage, as well as pH, acidity, syneresis, viscosity, viable lactic bacteria, and total coliforms were also assessed. In the second experiment, yogurts were submitted to lyophilization process, performed by scanning electron microscopy analysis and subsequently in those reconstituted, in addition to being assessed the physicochemical, rheological, and viable lactic bacteria characteristics. The results found in the first experiment showed that heat treatment was positive for viscosity, syneresis, and lactic bacteria, being viable until the 15th day of storage only for yogurts submitted to heat treatment. In the second experiment, lyophilization preserved the physicochemical characteristics of yogurts, but the number of initial lactic bacteria was different, also negatively affecting yogurt viscosity.

  12. THE INFLUENCE OF TOP MANAGEMENT DEMOGRAPHIC CHARACTERISTICS ON DECISION MAKING APPROACHES

    Directory of Open Access Journals (Sweden)

    Ivana Bulog

    2016-12-01

    Full Text Available Today’s organizational environment requires managers to be an excellent decision maker with the ability to make effective decisions which will shape business performance. Because of the role that managers have in today’s business settings, research interest in the relationship between individual characteristics and managerial decision making in all its aspects has increased over the last decade. This paper aims to provide an overview and discussion of how individuals make choices and decisions by examining the influence of top management demographic characteristics on decision making approaches. Findings suggest that demographic characteristics appear to be valuable for predicting which decision making approach managers prefer. The results of the study show that the average age and education level of decision makers is positively related to the rational decision making approach and negatively to the intuitive decision making approach. Tenure is positively related to the intuitive decision making approach, but the influence is not statistically significant. Also, a difference in the decision making approach was found with respect to gender. In light of the research findings, implications and limitations were discussed and some possibilities for future research are suggested.

  13. Phytoremediation in the tropics - influence of heavy crude oil on root morphological characteristics of graminoids

    Energy Technology Data Exchange (ETDEWEB)

    Merkl, Nicole [Institute of Plant Production and Agroecology in the Tropics and Subtropics, Department of Biodiversity and Land Rehabilitation, University of Hohenheim, D-70593 Stuttgart (Germany) and PDVSA - Intevep, Centro de Investigacion y Apoyo Tecnologico de Petroleos de Venezuela S.A., Departamento de Ecologia y Ambiente, P.O. Box 76343, Caracas 1070-A (Venezuela)]. E-mail: nmerkl@uni-hohenheim.de; Schultze-Kraft, Rainer [Institute of Plant Production and Agroecology in the Tropics and Subtropics, Department of Biodiversity and Land Rehabilitation, University of Hohenheim, D-70593 Stuttgart (Germany)]. E-mail: rsk@uni-hohenheim.de; Infante, Carmen [PDVSA - Intevep, Centro de Investigacion y Apoyo Tecnologico de Petroleos de Venezuela S.A., Departamento de Ecologia y Ambiente, P.O. Box 76343, Caracas 1070-A (Venezuela) and Universidad Simon Bolivar (USB), FUNINDES, Unidad de Gestion Ambiental, Caracas (Venezuela)]. E-mail: luchoben@cantv.net

    2005-11-15

    When studying species for phytoremediation of petroleum-contaminated soils, one of the main traits is the root zone where enhanced petroleum degradation takes place. Root morphological characteristics of three tropical graminoids were studied. Specific root length (SRL), surface area, volume and average root diameter (ARD) of plants grown in crude oil-contaminated and uncontaminated soil were compared. Brachiaria brizantha and Cyperus aggregatus showed coarser roots in polluted soil compared to the control as expressed in an increased ARD. B. brizantha had a significantly larger specific root surface area in contaminated soil. Additionally, a shift of SRL and surface area per diameter class towards higher diameters was found. Oil contamination also caused a significantly smaller SRL and surface area in the finest diameter class of C. aggregatus. The root structure of Eleusine indica was not significantly affected by crude oil. Higher specific root surface area was related to higher degradation of petroleum hydrocarbons found in previous studies. - Describing the effect of crude oil on root morphology of tropical graminoids the work assists in the selection of plant species for phytoremediation of oil-contaminated soils.

  14. Environmental mobility of cobalt-Influence of solid phase characteristics and groundwater chemistry

    International Nuclear Information System (INIS)

    Payne, T.E.; Itakura, T.; Comarmond, M.J.; Harrison, J.J.

    2009-01-01

    The adsorption of cobalt on samples from a potential waste repository site in an arid region was investigated in batch experiments, as a function of various solution phase parameters including the pH and ionic strength. The samples were characterized using a range of techniques, including BET surface area measurements, total clay content and quantitative X-ray diffraction. The statistical relationships between the measured cobalt distribution coefficients (K d values) and the solid and liquid phase characteristics were assessed. The sorption of cobalt increased with the pH of the aqueous phase. In experiments with a fixed pH value, the measured K d values were strongly correlated to the BET surface area, but not to the amount of individual clay minerals (illite, kaolinite or smectite). A further set of sorption experiments was undertaken with two samples of distinctive mineralogy and surface area, and consequently different sorption properties. A simple surface complexation model (SCM) that conceptualized the surface sites as having equivalent sorption properties to amorphous Fe-oxide was moderately successful in explaining the pH dependence of the sorption data on these samples. Two different methods of quantifying the input parameters for the SCM were assessed. While a full SCM for cobalt sorption on these complex environmental substrates is not yet possible, the basic applicability and predictive capability of this type of modeling is demonstrated. A principal requirement to further develop the modeling approach is adequate models for cobalt sorption on component mineral phases of complex environmental sorbents.

  15. Influence of TiO{sub 2} Surface Properties on Water Pollution Treatment and Photocatalytic Activity

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Min [Southwest Univ. of Science and Technology, Mianyang (China)

    2013-03-15

    The titania surface showed different characteristics depending on the charge of the dye molecules. Compared with the MB molecules, the negatively charged MO molecules strongly adsorbed on the titania surface. Furthermore, the decomposition kinetics of the dye molecules by the photocatalytic activity also deepened with the charge of the dye molecules. The relation between the UV irradiation time and the molar ratio of the decomposed dye molecules followed the Avrami equation. According to the results of the analysis by using the Avrami equation, the MO molecules were decomposed on the titania particle surface. In contrast, the MB molecules were decomposed in the aqueous solution. The difference in kinetics was related to the interaction of the dye molecules and the titania surface. These preferential adsorption and decomposition characteristics will improve its applications in water pollution treatment.

  16. Influence of nozzle arrangement on flow and heat transfer characteristics of arrays of circular impinging jets

    Directory of Open Access Journals (Sweden)

    Perapong Tekasakul

    2013-04-01

    Full Text Available The effect of jet arrangements on flow and heat transfer characteristics was experimentally and numerically investigatedfor arrays of impinging jets. The air jets discharge from round orifices and perpendicularly impinge on a surface within arectangular duct. Both the in-line and staggered arrangements, which have an array of 6×4 nozzles, were examined. A jet-toplate distance (H and jet-to-jet distance (S were fixed at H=2D and S=3D, respectively (where D is the round orificediameter. The experiments were carried out at jet Reynolds number Re=5,000, 7,500 and 13,400. Temperature distributions onthe impingement surface were measured using a Thermochromic Liquid Crystal sheet, and Nusselt number distributions wereevaluated using an image processing method. The flow characteristics on the impingement surface were visualized using theoil film technique. The numerical simulation employed to gain insight into the fluid flow of jets between the orifice plate andthe impingement wall was via computational fluid dynamics. The results reveal that the effect of crossflow on the impingingjets for the staggered arrangement is stronger than that in the case of in-line arrangement. In the latter case of in-line arrangement, the crossflow could pass throughout the passage between the rows of jets, whereas in the former case the crossflowwas hampered by the downstream jets. The average Nusselt number of the in-line arrangement is higher than that of thestaggered arrangement by approx. 13-20% in this study.

  17. Evaluation of the physicochemical characteristics of crospovidone that influence solid dispersion preparation.

    Science.gov (United States)

    Nakanishi, Sayaka; Fujii, Makiko; Sugamura, Yuka; Suzuki, Ayako; Shibata, Yusuke; Koizumi, Naoya; Watanabe, Yoshiteru

    2011-07-15

    A solid dispersion (SD) powder of indomethacin (IM) with crospovidone (CrosPVP) shows useful characteristics for manufacturing dosage forms. Four types of commercial CroPVP, Polyplasdone XL (XL) used as the initial carrier, Polyplasdone XL10 and INF-10 manufactured by milling XL, and Kollidon CL (CL) marketed by another company, were compared. The limit of the IM-CrosPVP weight ratio with which an SD can be prepared (maximum IM content) was calculated on the basis of the heat of fusion of physical mixtures of IM and CrosPVP with various weight ratios. When Polyplasdones were used, the maximum IM content increased with the specific surface area of the CrosPVP. When CL was used, however, it was about half of that obtained with XL, even though the difference between XL and CL was not observed in the physicochemical characteristics (particle size, specific surface area, flowability, glass transition temperature, IR spectra, and solid state NMR spectra). As determined by pore size distribution measurement, the volume of pore of which size is larger than the particle size of IM was less in CL than in XL. Therefore, the effective surface area of CrosPVP that comes in contact with IM is important for the preparation of the SD. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. INFLUENCE OF AISI 316Ti STAINLESS STELL SURFACE TREATMENT ON PITTING CORROSION IN VARIOUS SOLUTIONS

    Directory of Open Access Journals (Sweden)

    Pavol Fajnor

    2010-12-01

    Full Text Available Investigation of the surface treatment effect on the resistance of AISI 316Ti stainless steel to pitting corrosion is presented in this paper. The grinded surfaces without additional chemical treatment, grinded and pickled, grinded, pickled and passivated surfaces are tested. The corrosion tests are carried out by exposition in solution which evoke pitting and by electrochemical cyclic potential - sweep method. According to the results the surface treatment has a great influence on the resistance of the tested material to pitting. It is not possible to estimate the best surface treatment because behavior of AISI 316Ti stainless steel with different surface state depends on the mechanism of corrosion processes which vary in the used experimental methods.

  19. Trends of urban surface temperature and heat island characteristics in the Mediterranean

    Science.gov (United States)

    Benas, Nikolaos; Chrysoulakis, Nektarios; Cartalis, Constantinos

    2017-11-01

    Urban air temperature studies usually focus on the urban canopy heat island phenomenon, whereby the city center experiences higher near surface air temperatures compared to its surrounding non-urban areas. The Land Surface Temperature (LST) is used instead of urban air temperature to identify the Surface Urban Heat Island (SUHI). In this study, the nighttime LST and SUHI characteristics and trends in the seventeen largest Mediterranean cities were investigated, by analyzing satellite observations for the period 2001-2012. SUHI averages and trends were based on an innovative approach of comparing urban pixels to randomly selected non-urban pixels, which carries the potential to better standardize satellite-derived SUHI estimations. A positive trend for both LST and SUHI for the majority of the examined cities was documented. Furthermore, a 0.1 °C decade-1 increase in urban LST corresponded to an increase in SUHI by about 0.04 °C decade-1. A longitudinal differentiation was found in the urban LST trends, with higher positive values appearing in the eastern Mediterranean. Examination of urban infrastructure and development factors during the same period revealed correlations with SUHI trends, which can be used to explain differences among cities. However, the majority of the cities examined show considerably increased trends in terms of the enhancement of SUHI. These findings are considered important so as to promote sustainable urbanization, as well as to support the development of heat island adaptation and mitigation plans in the Mediterranean.

  20. Evaluation of surface characteristics under fretting of electrical contacts: Removal behaviour of hot dipped tin coating

    International Nuclear Information System (INIS)

    Park, Young Woo; Ramesh Bapu, G.N.K.; Lee, Kang Yong

    2009-01-01

    The fretting corrosion behaviour of hot dipped tin coating is investigated at low fretting cycles at ±25 μm displacement amplitude, 0.5N normal load, 3 Hz frequency, 45-50% relative humidity, and 25 ± 1 deg. C temperature. The typical characteristics of the change in contact resistance with fretting cycles are explained. The fretted surface is examined using laser scanning microscope, scanning electron microscope and energy dispersive X-ray analysis to assess the surface profile, extent of fretting damage, extent of oxidation and elemental distribution across the contact zone. The interdependence of extent of wear and oxidation increases the complexity of the fretting corrosion behaviour of tin coating. The variation of contact resistance clearly revealed the fretting of tin coating from 50 to 1200 cycles and the fretting of the substrate above 1200 cycles. The observed low and stable contact resistance region and the fluctuating resistance region at various fretting cycles are explained and substantiated with Scanning electron microscopy (SEM), laser scanning microscope (LSM) and energy dispersive analysis of X-rays (EDAX) analysis results of the fretted surface.