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Sample records for wettability rock framework

  1. Improved Oil Recovery in Chalk. Spontaneous Imbibition affected by Wettability, Rock Framework and Interfacial Tension

    Energy Technology Data Exchange (ETDEWEB)

    Milter, J.

    1996-12-31

    The author of this doctoral thesis aims to improve the oil recovery from fractured chalk reservoirs, i.e., maximize the area of swept zones and their displacement efficiencies. In order to identify an improved oil recovery method in chalk, it is necessary to study wettability of calcium carbonate and spontaneous imbibition potential. The thesis contains an investigation of thin films and wettability of single calcite surfaces. The results of thin film experiments are used to evaluate spontaneous imbibition experiments in different chalk types. The chalk types were described detailed enough to permit considering the influence of texture, pore size and pore throat size distributions, pore geometry, and surface roughness on wettability and spontaneous imbibition. Finally, impacts of interfacial tension by adding anionic and cationic surfactants to the imbibing water phase are studied at different wettabilities of a well known chalk material. 232 refs., 97 figs., 13 tabs.

  2. Pore-Scale Study of the Impact of Fracture and Wettability on Two-Phase Flow Properties of Rock

    Energy Technology Data Exchange (ETDEWEB)

    Silin, D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ajo-Franklin, J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Helland, J. O. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Jettestuen, E. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hatzignatiou, D. G. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-08-01

    Fractures and wettability are among other factors that can strongly affect the twophase flow properties of porous media. Maximal-inscribed spheres (MIS) and finite-difference flow simulations on computer-generated structures mimicking micro-CT images of fractured rock suggest the character of the capillary pressure and relative permeability curves modification by natural or induced fracture and wettability alteration.

  3. CO2-Water-Rock Wettability: Variability, Influencing Factors, and Implications for CO2Geostorage.

    Science.gov (United States)

    Iglauer, Stefan

    2017-05-16

    Carbon geosequestration (CGS) has been identified as a key technology to reduce anthropogenic greenhouse gas emissions and thus significantly mitigate climate change. In CGS, CO 2 is captured from large point-source emitters (e.g., coal fired power stations), purified, and injected deep underground into geological formations for disposal. However, the CO 2 has a lower density than the resident formation brine and thus migrates upward due to buoyancy forces. To prevent the CO 2 from leaking back to the surface, four trapping mechanisms are used: (1) structural trapping (where a tight caprock acts as a seal barrier through which the CO 2 cannot percolate), (2) residual trapping (where the CO 2 plume is split into many micrometer-sized bubbles, which are immobilized by capillary forces in the pore network of the rock), (3) dissolution trapping (where CO 2 dissolves in the formation brine and sinks deep into the reservoir due to a slight increase in brine density), and (4) mineral trapping (where the CO 2 introduced into the subsurface chemically reacts with the formation brine or reservoir rock or both to form solid precipitates). The efficiency of these trapping mechanisms and the movement of CO 2 through the rock are strongly influenced by the CO 2 -brine-rock wettability (mainly due to the small capillary-like pores in the rock which form a complex network), and it is thus of key importance to rigorously understand CO 2 -wettability. In this context, a substantial number of experiments have been conducted from which several conclusions can be drawn: of prime importance is the rock surface chemistry, and hydrophilic surfaces are water-wet while hydrophobic surfaces are CO 2 -wet. Note that CO 2 -wet surfaces dramatically reduce CO 2 storage capacities. Furthermore, increasing pressure, salinity, or dissolved ion valency increases CO 2 -wettability, while the effect of temperature is not well understood. Indeed theoretical understanding of CO 2 -wettability and the

  4. WETTABILITY ALTERATION OF CARBONATE ROCK MEDIATED BY BIOSURFACTANT PRODUCED FROM HIGH-STARCH AGRICULTURAL EFFLUENTS

    Energy Technology Data Exchange (ETDEWEB)

    Mehdi Salehi; Stephen Johnson; Gregory Bala; Jenn-Tai Liang

    2006-09-01

    Surfactants can be used to alter wettability of reservoir rock, increasing spontaneous imbibition and thus improving oil yields. Commercial synthetic surfactants are often prohibitively expensive and so a crude preparation of the anionic biosurfactant, surfactin, from Bacillus subtilis grown on high-starch industrial and agricultural effluents has been proposed as an economical alternative. To assess the effectiveness of the surfactin, it is compared to commercially available surfactants. In selecting a suitable benchmark surfactant, two metrics are examined: the ability of the surfactants to alter wettability at low concentrations, and the degree to which they are absorbed onto reservoir matrix. We review the literature to survey the adsorption models that have been developed to describe surfactant adsorption in porous media. These models are evaluated using the experimental data from this study. Crushed carbonate rock samples are cleaned and aged in crude oil. The wettability change mediated by dilute solutions of commercial anionic surfactants and surfactin is assessed using a two-phase separation; and surfactant loss due to retention and adsorption the rock is determined.

  5. A Percolation Study of Wettability Effect on the Electrical Properties of Reservoir Rocks

    DEFF Research Database (Denmark)

    Zhou, Dengen; Arbabi, Sepehr; Stenby, Erling Halfdan

    1997-01-01

    Measurements of the electrical resistivity of oil reservoirs are commonly used to estimate other properties of reservoirs, such as porosity and hydrocarbon reserves. However, the interpretation of the measurements is based on empirical correlations, because the underlying mechanisms that control...... the electrical properties of oil bearing rocks have not been well understood. In this paper, we employ percolation concepts to investigate the effect of wettability on the electrical conductivity of a reservoir formation. A three-dimensional simple cubic network is used to represent an ideal reservoir formation...

  6. Nano-scale experimental investigation of in-situ wettability and spontaneous imbibition in ultra-tight reservoir rocks

    Science.gov (United States)

    Akbarabadi, Morteza; Saraji, Soheil; Piri, Mohammad; Georgi, Dan; Delshad, Mohammad

    2017-09-01

    We investigated spontaneous imbibition behavior, three-dimensional fluid occupancy maps, and in-situ wettability at the nano scale in five ultra-tight and shale reservoir rock samples. For this purpose, we developed a novel technique by integrating a custom-built in-situ miniature fluid-injection module with a non-destructive high-resolution X-ray imaging system. Small cylindrical core samples (15-60 μm in diameter) were prepared from reservoir rocks using Focused-Ion Beam (FIB) milling technique. The pore network inside the samples were first characterized using ultra-high resolution three-dimensional images obtained at initial state by X-ray nano-tomography (Nano-CT) and FIB-Scanning Electron Microscopy (FIB-SEM) techniques at the nano scale. The petrophysical parameters, including porosity, permeability, pore-size distribution, and organic content were computed for each sample using image analysis. We then performed series of imbibition experiments using brine, oil, and surfactant solutions on each core sample. We observed that both oil and brine phases spontaneously imbibe into the pore network of the rock samples at various quantities. We also, for the first time, examined fluid distribution in individual pores and found a complex wettability behavior at the pore scale in the reservoir rock samples. Three pore types were identified with water-wet, oil-wet, and fractionally-wet behaviors. This work opens a new path to developing an improved understanding of the pore-level physics involved in multi-phase flow and transport not only in tight rock samples but also in other nanoporous material used in different science and engineering applications.

  7. Effect of Brine Composition on Wettability Alteration and Oil Recovery from Oil-wet Carbonate Rocks

    Science.gov (United States)

    Purswani, P.; Karpyn, Z.

    2016-12-01

    Brine composition is known to affect the effectiveness of waterflooding during enhanced oil recovery from carbonate reservoirs. Recent studies have identified Mg2+, Ca2+ and SO42- as critical ions, responsible for incremental oil recovery via wettability alteration. To investigate the underlying mechanism of wettability alteration and, to evaluate the individual contribution of these ions towards improving oil recovery, a series of coreflooding experiments are performed. Various characterization techniques like zeta potential (ZP), drop angle analysis and inductively coupled plasma mass spectrometry (ICP MS) analysis are performed to evaluate the surface interactions taking place at the carbonate core samples, brine solution and crude oil interfaces. Total dissolved solids and electrical conductivity measurements confirm the ionic strength of the brine samples. Acid number calculations, ZP and contact angle measurements confirm the initial oil-wetting state of the core. ICP MS analysis of the effluent brine, confirm the relationship between the ionic interactions and oil recovery.

  8. Investigation of CO2 Enhanced Oil Recovery Using Dimensionless Groups in Wettability Modified Chalk and Sandstone Rocks

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    Vahid Alipour Tabrizy

    2014-01-01

    Full Text Available The paper addresses enhanced oil recovery in chalk and sandstone rocks by CO2 injection, with different wettability, porosity, and permeability as well as injection rate and flooding conditions. Results indicate that an increase in Bond number has a positive effect on oil recovery whereas for capillary number, there is a limit in which recovery is improving. This limit is estimated when the pressure drop by viscous force is approximately equal to the threshold balance between capillary and gravity forces. A dimensionless group is proposed that combines the effect of capillarity, injection rate, permeability, and CO2 diffusion on the oil recovery. Recovery from all experiments in this study and reported data in the literature shows a satisfactory relationship with the proposed group.

  9. Characterization of Rock Wettability Though Dielectric Measurements Caractérisation de la mouillabilité des roches au moyen de mesures diélectriques

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    Bona N.

    2006-12-01

    Full Text Available The wettability of glass filters and Berea sandstone was investigated using the electric response in the interval 10² - 10 (to the power of 8 Hz. The natural wettability of the materials was modified to get two different sets of samples, one with strong water and the other with strong oil wettability. The samples were saturated to various degrees up to 40% with deionized water or brine. Measurements showed that the electric responses of water-wet and oil-wet samples were markedly different and more complex than those predicted by two standard models. The dispersivity and the loss tangent were found to be the most suitable parameters to check the wettability of the samples. La mouillabilité de filtres de verre et de grès de Béréa a été caractérisée par leur réponse électrique dans l'intervalle 10² - 10 puissance 8 Hz. Au moyen de traitements appropriés, la mouillabilité naturelle des matériaux a été modifiée afin d'obtenir deux séries différentes d'échantillons ayant respectivement de fortes mouillabilités à l'eau et à l'huile. Les échantillons ont été saturés à des degrés variés (pas plus de 40 % avec de l'eau permutée ou de la saumure. Les mesures ont montré que les réponses électriques des échantillons mouillables à l'eau ou mouillables à l'huile étaient nettement différentes et plus compliquées que celles prédites par deux modèles standard. En outre, on a pu constater que la dispersivité et la tangente de pertes constituent les paramètres les plus pertinents pour caractériser la mouillabilité des échantillons.

  10. 76 FR 771 - Reorganization/Expansion of Foreign-Trade Zone 14 Under Alternative Site Framework; Little Rock, AR

    Science.gov (United States)

    2011-01-06

    ... Framework; Little Rock, AR Pursuant to its authority under the Foreign-Trade Zones Act of June 18, 1934, as... White Counties, Arkansas, within and adjacent to the Little Rock Customs and Border ] Protection port of...

  11. Wettability Studies Using Zeta Potential Measurements

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    Ghada Bassioni

    2015-01-01

    Full Text Available Wettability studies have been carried out on reservoir rocks using different techniques such as the Amott-Harvey method, the USBM method, and the contact angle method, all with limitations. In this study, the wettability is studied by discussing the surface charge using zeta potential measurements. The study relies on the finding that carbonated reservoir rocks, consisting of CaCO3 mainly, are positively charged and their surface has the potential to adsorb significant quantities of anions. Moreover, heavy fractions such as asphaltenes are reported to remain afloat depending on dispersive forces present in the oil and its various fractions. Experiments are carried out on aqueous limestone suspension with the addition of crude oil. The experiment is repeated with the use of polymeric inhibitors, A and B. The zeta potential is found to alter depending on the sequence of polymeric inhibitor in oil/water addition. The inhibitor is found to adsorb on the limestone surface, with a net negative charge, causing repulsion between crude oil and the inhibitor and, hence, preventing the deposition of heavy fractions and particularly asphaltenes. This study gives a comprehensive insight on the mechanism of polymeric inhibitor interaction with the surface and the effect of wettability on its performance.

  12. Wettability of graphene.

    Science.gov (United States)

    Raj, Rishi; Maroo, Shalabh C; Wang, Evelyn N

    2013-04-10

    Graphene, an atomically thin two-dimensional material, has received significant attention due to its extraordinary electronic, optical, and mechanical properties. Studies focused on understanding the wettability of graphene for thermo-fluidic and surface-coating applications, however, have been sparse. Meanwhile, wettability results reported in literature via static contact angle measurement experiments have been contradictory and highlight the lack of clear understanding of the underlying physics that dictates wetting behavior. In this work, dynamic contact angle measurements and detailed graphene surface characterizations were performed to demonstrate that the defects present in CVD grown and transferred graphene coatings result in unusually high contact angle hysteresis (16-37°) on these otherwise smooth surfaces. Hence, understanding the effect of the underlying substrate based on static contact angle measurements as reported in literature is insufficient. The advancing contact angle measurements on mono-, bi-, and trilayer graphene sheets on copper, thermally grown silica (SiO2), and glass substrates were observed to be independent of the number of layers of graphene and in good agreement with corresponding molecular dynamics simulations and theoretical calculations. Irrespective of the number of graphene layers, the advancing contact angle values were also in good agreement with the advancing contact angle on highly ordered pyrolytic graphite (HOPG), reaffirming the negligible effect of the underlying substrate. These results suggest that the advancing contact angle is a true representation of a graphene-coated surface while the receding contact angle is significantly influenced by intrinsic defects introduced during the growth and transfer processes. These observations, where the underlying substrates do not affect the wettability of graphene coatings, is shown to be due to the large interlayer spacing resulting from the loose interlamellar coupling between

  13. Étude de la mouillabilité des roches réservoir à l'échelle du pore par cryomicroscopie électronique à balayage Wettability of Reservoir Rock At the Pore Scale: Contribution of Cryo-Scanning Electron Microscopy

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    Fassi-Fihri O.

    2006-11-01

    éralogie qui est plutôt homogène. Wettability is generally considered to be one of the principal parameters influencing the distribution, saturation and flow of fluids in porous media. Reservoir rock wettability has long been approached by overall or indirect methods [1] (capillary pressure or relative permeability curves, contact angle, fluid displacement, etc. . Few studies until now have led to a detailed description of porous media with intermediate wettability. - Is there any evidence of an intermediate behavior of fluids in contact with minerals distributed homogeneously throughout the medium, or is there a heterogeneous distribution of water- and oil-wettabilities within the porous medium?- What influence does the local heterogeneity of the minerals (size, geometry, surface chemistry, etc. have on fluid distribution [2 to 7]?The answer to these questions requires a microscopic-scale description of saturated porous media [8 to 11]. By using the imaging and analytical capabilities of a scanning electron microscope coupled with a cold stage unit, fluids can be visualized and identified by detection of their natural tracer element (sulfur for oil and chlorine for brine, and their relative distribution within the pore space can be analyzed in terms of wettability. Results presented here illustrate both the interest of the method and its applicability to actual reservoir rocks. Small cores of the chosen porous media were first saturated with brine, flooded to irreducible water saturation by centrifuging in oil, aged in oil for one month and finally flooded to residual oil saturation by centrifuging in brine. Samples were then frozen in nitrogen slush, freeze fractured and coated before being transferred to the cold stage of the microscope for observation. Experiments were first conducted on porous media with controlled wettability : model sintered glass media, natural clean sandstone (Fontainebleau and clayey sandstones (Vosges, Velaines. All these porous media are

  14. Experimental investigation of wettability alteration on residual oil saturation using nonionic surfactants: Capillary pressure measurement

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    Masoud Amirpour

    2015-12-01

    Full Text Available Introducing the novel technique for enhancing oil recovery from available petroleum reservoirs is one of the important issues in future energy demands. Among of all operative factors, wettability may be the foremost parameter affecting residual oil saturation in all stage of oil recovery. Although wettability alteration is one of the methods which enhance oil recovery from the petroleum reservoir. Recently, the studies which focused on this subject were more than the past and many contributions have been made on this area. The main objective of the current study is experimentally investigation of the two nonionic surfactants effects on altering wettability of reservoir rocks. Purpose of this work is to change the wettability to preferentially the water-wet condition. Also reducing the residual oil saturation (Sor is the other purpose of this work. The wettability alteration of reservoir rock is measured by two main quantitative methods namely contact angle and the USBM methods. Results of this study showed that surfactant flooding is more effective in oil-wet rocks to change their wettability and consequently reducing Sor to a low value. Cedar (Zizyphus Spina Christi is low priced, absolutely natural, and abundantly accessible in the Middle East and Central Asia. Based on the results, this material can be used as a chemical surfactant in field for enhancing oil recovery.

  15. The Influence Factors Analysis and Characteristics Research of Shale Wettability

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    Su, Siyuan; jiang, Zhenxue

    2017-04-01

    Shales have become one of the leading unconventional oil and gas resources in the world today. The wettability is an important indicator of the rock that reflects the lipophilic and hydrophilic which not only affect oil and water distribution but also can affect the capillary pressure, relative permeability and irreducible water saturation. We present a study of shale wettability using Nuclear Magnetic Resonance (NMR) to monitor sequential imbibition of brine and oil (Dodecane).A total of eleven shale samples of Jiyang Depression of China were analyzed and compared abundance of organic matter, the movable hydrocarbon content, clay content and carbonate content with different wettability. The results showed that the contents of total organic carbon (TOC) with mixed wetting characteristic of shale samples are greater than just water wetting characteristic of shale samples that shows with the increase of TOC content, porosity can be convert into oil wetting by water wetting and the inorganic pores convert into organic pores. It indicates the presence of organic matter is the root cause of mix wettability with the organics contributing mainly to the oil-wetness of the shale samples. The samples that have oil-wetness are higher than the samples only water wetting on movable hydrocarbon contents and clay contents which shows the organic matters are accompanied with clay in the study area. But the samples that only for water wetting have the higher carbonate contents than the oil-wetness samples which indicate the inorganic pores are mainly formed by carbonate rocks. In summary, the shale reservoirs with mix wettability can be used as shale oil enriched favorable exploration targets.

  16. Modeling Wettability Variation during Long-Term Water Flooding

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    Renyi Cao

    2015-01-01

    Full Text Available Surface property of rock affects oil recovery during water flooding. Oil-wet polar substances adsorbed on the surface of the rock will gradually be desorbed during water flooding, and original reservoir wettability will change towards water-wet, and the change will reduce the residual oil saturation and improve the oil displacement efficiency. However there is a lack of an accurate description of wettability alternation model during long-term water flooding and it will lead to difficulties in history match and unreliable forecasts using reservoir simulators. This paper summarizes the mechanism of wettability variation and characterizes the adsorption of polar substance during long-term water flooding from injecting water or aquifer and relates the residual oil saturation and relative permeability to the polar substance adsorbed on clay and pore volumes of flooding water. A mathematical model is presented to simulate the long-term water flooding and the model is validated with experimental results. The simulation results of long-term water flooding are also discussed.

  17. Predicting reservoir wettability via well logs

    Science.gov (United States)

    Feng, Cheng; Fu, Jinhua; Shi, Yujiang; Li, Gaoren; Mao, Zhiqiang

    2016-06-01

    Wettability is an important factor in controlling the distribution of oil and water. However, its evaluation has so far been a difficult problem because no log data can directly indicate it. In this paper, a new method is proposed for quantitatively predicting reservoir wettability via well log analysis. Specifically, based on the J function, diagenetic facies classification and the piecewise power functions, capillary pressure curves are constructed from conventional logs and a nuclear magnetic resonance (NMR) log respectively. Under the influence of wettability, the latter is distorted while the former remains unaffected. Therefore, the ratio of the median radius obtained from the two kinds of capillary pressure curve is calculated to reflect wettability, a quantitative relationship between the ratio and reservoir wettability is then established. According to the low-permeability core sample capillary pressure curve, NMR {{T}2} spectrum and contact angle experimental data from the bottom of the Upper Triassic reservoirs in western Ordos Basin, China, two kinds of constructing capillary pressure curve models and a predictive wettability model are calibrated. The wettability model is verified through the Amott wettability index and saturation exponent from resistivity measurement and their determined wettability levels are comparable, indicating that the proposed model is quite reliable. In addition, the model’s good application effect is exhibited in the field study. Thus, the quantitatively predicting reservoir wettability model proposed in this paper provides an effective tool for formation evaluation, field development and the improvement of oil recovery.

  18. WETTABILITY AND PREDICTION OF OIL RECOVERY FROM RESERVOIRS DEVELOPED WITH MODERN DRILLING AND COMPLETION FLUIDS

    Energy Technology Data Exchange (ETDEWEB)

    Jill S. Buckley; Norman R. Morrow

    2006-01-01

    The objectives of this project are: (1) to improve understanding of the wettability alteration of mixed-wet rocks that results from contact with the components of synthetic oil-based drilling and completion fluids formulated to meet the needs of arctic drilling; (2) to investigate cleaning methods to reverse the wettability alteration of mixed-wet cores caused by contact with these SBM components; and (3) to develop new approaches to restoration of wetting that will permit the use of cores drilled with SBM formulations for valid studies of reservoir properties.

  19. Wettability of magnesium based alloys

    Science.gov (United States)

    Ornelas, Victor Manuel

    The premise of this project was to determine the wettability behavior of Mg-based alloys using three different liquids. Contact angle measurements were carried out along with utilizing the Zisman method for obtaining values for the critical surface tension. Adhesion energy values were also found through the use of the Young-Dupre equation. This project utilized the Mg-based alloy Mg-2Zn-2Gd with supplemented alpha-Minimum Essential Medium (MEM), Phosphate Buffer Saline solution (PBS), and distilled water. These three liquids are commonly used in cell cultivation and protein adsorption studies. Supplemented alpha-MEM consisted of alpha-MEM, fetal bovine serum, and penicillin-streptomycin. Mg-2Zn-2Gd was used because of observed superior mechanical properties and better corrosion resistance as compared to conventional Mg-alloys. These attractive properties have made it possible for this alloy to be used in biomedical devices within the human body. However, the successful use of this alloy system in the human body requires knowledge in the response of protein adsorption on the alloy surface. Protein adsorption depends on many parameters, but one of the most important factors is the wettability behavior at the surface.

  20. Characterisation of surface wettability based on nanoparticles.

    Science.gov (United States)

    Gao, Nan; Yan, Yuying

    2012-04-07

    Nanoparticles are becoming frequently used in the research area of creating functional surfaces because they can be more versatile than just making dimensions smaller. Particularly, a variety of nanoparticles have been applied for the construction of superhydrophobic and superhydrophilic surfaces with micro- and nano-scaled structures. As nanoparticles can also be fashioned and modified, their effects will be of great importance to the formed surface structures. In the present paper, we review the recent research progress in the utilization of nanoparticles to form extremely wettable/non-wettable surface structures and their influence on surface wettability. This report manifests an apparent inclination of nanoparticle structured surfaces using the multidisciplinary approaches, from the viewpoint of engineer/scientist. Therefore, the typical methodologies with regard to the use of nanoparticles, including the preparation and functionalisation processes, for the realization of surface wettabilities are discussed in this work. The discussions also represent some of the size-determined phenomena that are related to wettable/non-wettable surfaces. This Review thus provides an insight into the connection between nanoparticles and surface wettability. This journal is © The Royal Society of Chemistry 2012

  1. Integrated, Multi-Scale Characterization of Imbibition and Wettability Phenomena Using Magnetic Resonance and Wide-Band Dielectric Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Mukul M. Sharma; Steven L. Bryant; Carlos Torres-Verdin; George Hirasaki

    2007-09-30

    The petrophysical properties of rocks, particularly their relative permeability and wettability, strongly influence the efficiency and the time-scale of all hydrocarbon recovery processes. However, the quantitative relationships needed to account for the influence of wettability and pore structure on multi-phase flow are not yet available, largely due to the complexity of the phenomena controlling wettability and the difficulty of characterizing rock properties at the relevant length scales. This project brings together several advanced technologies to characterize pore structure and wettability. Grain-scale models are developed that help to better interpret the electric and dielectric response of rocks. These studies allow the computation of realistic configurations of two immiscible fluids as a function of wettability and geologic characteristics. These fluid configurations form a basis for predicting and explaining macroscopic behavior, including the relationship between relative permeability, wettability and laboratory and wireline log measurements of NMR and dielectric response. Dielectric and NMR measurements have been made show that the response of the rocks depends on the wetting and flow properties of the rock. The theoretical models can be used for a better interpretation and inversion of standard well logs to obtain accurate and reliable estimates of fluid saturation and of their producibility. The ultimate benefit of this combined theoretical/empirical approach for reservoir characterization is that rather than reproducing the behavior of any particular sample or set of samples, it can explain and predict trends in behavior that can be applied at a range of length scales, including correlation with wireline logs, seismic, and geologic units and strata. This approach can substantially enhance wireline log interpretation for reservoir characterization and provide better descriptions, at several scales, of crucial reservoir flow properties that govern oil

  2. Wettability of nonwoven polymeric nanofiber mats

    Science.gov (United States)

    Munoz, Edgar

    The wettability of heterogeneous materials has been attracting special interest by academia and industrial sector given the need to development self-cleaning Nonwoven nanofiber mats have demonstrated potential given its hydrophobicity granted by the ultimate structure of the system, small fiber diameter and small pores giving rise to effects such as the Cassie-Baxter. This thesis analyzed the wettability of a wide range of polymeric systems. Nanofiber mats were manufactured using the ForcespinningRTM technology. Samples were prepared at different polymeric concentrations and rotational speeds to alter fiber size; density of the mat was also altered to evaluate the effect of porosity on the wettability. Scanning Electron Microscopy (SEM) was used to characterize the mats and contact angle studies were conducted to better understand wettability of the developed surfaces.

  3. Changing Emulsion Dynamics with Heterogeneous Surface Wettability

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    Tsai, Peichun Amy; Meng, Qiang; Zhang, Yali; Li, Jiang; Lammertink, Rob; Chen, Haosheng

    2015-11-01

    We elucidate the effect of heterogeneous surface wettability on the morphology and dynamics of microfluidic emulsions, generated by a co-flowing device. We first design a useful methodology of modifying a micro-capillary with desired heterogeneous wettability, such as alternating hydrophilic and hydrophobic regions. Subsequently, the effects of flow rates and heterogeneous wettability on the emulsion morphology and motion in the micro-capillary are investigated. Our experimental data reveal a universal critical time scale of advective emulsions, above which the microfluidic emulsions remain intact, whereas below this time-scale emulsions become adhesive or inverse. A simple model based on a force balance can be used to explain this critical transition. These results show a control of emulsion dynamics by tuning the droplet size and the Capillary number, the ratio of viscous to surface effects, with heterogeneous surface wettability.

  4. WETTABILITY ALTERATION OF POROUS MEDIA TO GAS-WETTING FOR IMPROVING PRODUCTIVITY AND INJECTIVITY IN GAS-LIQUID FLOWS

    Energy Technology Data Exchange (ETDEWEB)

    Abbas Firoozabadi

    2003-12-01

    Wettability alteration to intermediate gas-wetting in porous media by treatment with FC-759, a fluoropolymer polymer, has been studied experimentally. Berea sandstone was used as the main rock sample in our work and its wettability before and after chemical treatment was studied at various temperatures from 25 to 93 C. We also studied recovery performance for both gas/oil and oil/water systems for Berea sandstone before and after wettability alteration by chemical treatment. Our experimental study shows that chemical treatment with FC-759 can result in: (1) wettability alteration from strong liquid-wetting to stable intermediate gas-wetting at room temperature and at elevated temperatures; (2) neutral wetting for gas, oil, and water phases in two-phase flow; (3) significant increase in oil mobility for gas/oil system; and (4) improved recovery behavior for both gas/oil and oil/water systems. This work reveals a potential for field application for improved gas-well deliverability and well injectivity by altering the rock wettability around wellbore in gas condensate reservoirs from strong liquid-wetting to intermediate gas-wetting.

  5. Salinity Influence on Interfacial Area, Wettability, and NAPL Recovery

    Science.gov (United States)

    Zhong, L.; Valenta, M. M.

    2007-12-01

    Wettability, the tendency of rock or sediment particle surfaces to be preferentially wet by one fluid phase, has a strong influence on the distribution and flow of immiscible fluids in oil reservoirs or aquifers. The efficiency of oil and non-aqueous phase liquid (NAPL) recovery processes and the displacement and production of oil/NAPL by fluids injected into the reservoir or aquifer depend on the wetting properties of the rock/sediment particle surfaces. Effects of salinity on wettability and residual oil saturation during water flooding are of particular interest in the petroleum industry with some reservoirs. It was indicated that the residual oil saturation may be reduced significantly by flooding with low salinity water instead of seawater or brine. This observation may be also true in NAPL recovery from contaminated aquifers. NAPL recovery enhancement may be achieved by manipulating the salinity of the remedial fluid. Two sets of 8 core-flooding column experiments have been completed, using decane and Alaska North Slope (ANS) crude oil as surrogate NAPLs. Unconsolidated sand packs were used as representative porous media. NAPL removal was conducted by flushing column at residual NAPL saturation using water with salinity ranging from 0% to 8% wt of NaCl. The NAPL-water interfacial area (anw, cm-1) was measured and used as an indicator for the wettability characteristics of the packed sand. Sodium Dodecyl Benzene Sulfonate (SDBS) was used as an interfacial partitioning tracer and Pentafluoro Benzoic acid (PFBA) was used as a non-reactive and non-partitioning tracer. NAPL was imbibed into an initially water saturated column, using positive displacement methods. NAPL was then flushed out using water at certain salinity. When the column attained a residual NAPL saturation after each water flushing displacement, the partitioning and conservative tracer experiments were conducted separately, to characterize the specific NAPL-water interfacial areas, and the

  6. Investigation on the anisotropic mechanical behaviour of the Callovo-Oxfordian clay rock within the framework of ANDRA/GRS cooperation programme. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chun-Liang [Gesellschaft fuer Anlagen- und Reaktorsicherheit mbH (GRS), Koeln (Germany); Armand, Gilles; Conil, Nathalie [French Agence Nationale Pour la Gestion de Dechets Radioactifs (ANDRA), Chatenay-Malabry (France)

    2015-01-15

    An underground repository for disposal of radioactive waste is planned to be constructed in the sedimentary Callovo-Oxfordian argillaceous formation (COX) in France /AND 05/. The clay rock exhibits inherent anisotropy with bedding structure, which leads to directional dependences of the rock properties (e.g. mineralogical, physical, mechanical, hydraulic, thermal, etc.) with respect to the bedding planes. For the design of the repository and the assessment of its safety during the operation and post-closure phases it is necessary to characterise and predict the anisotropic properties and processes in the host rock, particularly in the excavation damaged zone (EDZ) near the openings. Within the framework of the bilateral cooperation agreement between the French National Radioactive Waste Management Agency (ANDRA) and the German Federal Ministry of Economics and Technology (BMWi), concerning the research activities in the Meuse/Haute-Marne Underground Research Laboratory (MHM-URL), a joint research programme was initiated by ANDRA and GRS in 2013 to investigate mechanical anisotropy of the COX clay rock for the purpose of precise characterization, better understanding and reliable prediction of the development of EDZ around the repository. This programme was funded by ANDRA under contract number 059844 and performed by GRS during the time period of November 2013 to December 2014. GRS gratefully acknowledges the financial support from and the fruitful cooperation with ANDRA.

  7. First attempt to study rock glaciers in New Zealand using the Schmidt-hammer - framework and preliminary results

    Science.gov (United States)

    Winkler, Stefan; Lambiel, Christophe; Sattler, Katrin; Büche, Thomas; Springer, Johanna

    2016-04-01

    Although not uncommon within the dryer eastern parts of the Southern Alps, New Zealand, comparatively few previous studies have previously focused on rock glacier dynamics and spatial distribution. Neither investigations of their chronological constraints nor any studies on actual rock glacier velocities have yet been carried out. Rock glaciers and periglacial processes still largely constitute a largely unexplored albeit potentially valuable field of research in the Southern Alps. The high-altitude valley head of Irishman Stream in the Ben Ohau Range between Lakes Ohau and Pukaki, roughly 30 km southeast of the Main Divide, contains a few morphologically intact rock glaciers and some appear to be active features (Sattler et al. 2016). Previous work focusing on the Late-glacial and early Holocene moraines in the valley head below the rock glaciers (Kaplan et al. 2010) provided 10Be-ages that could be utilised as fixed points for SHD (Schmidt-hammer exposure-age dating). Apart from detailed Schmidt-hammer sampling on the Late-glacial and early Holocene moraines, two altitudinal transects from the toe to their apex have been measured in detail on selected rock glaciers. On each of the multiple ridges of the rock glacier surface three sites of 50 boulders have been sampled with one impact each by the hammer (an N-type electronic SilverSchmidt by Proceq). Apart from getting some age constraints of these periglacial features in comparison to the well-dated moraines, the Schmidt-hammer measurements also had the aim to provide some insight into their genetic development resulting in a quite complex morphology of the rock glaciers and partial interaction with some of the moraines. Both altitudinal transects reveal a clear and continuous trend of increasing means (i.e. less weathered/younger exposure ages) towards their apex. The values for the individual ridges show, however, a transitional character with adjacent ridges albeit the abovementioned trend not statistically

  8. WETTABILITY STUDIES OF LEAD-FREE SOLDERS

    African Journals Online (AJOL)

    2012-03-01

    Mar 1, 2012 ... wettability, solder, lead, alloy, tin. 1. Introduction. Tin-lead solder has been the standard mate- rial used in electronic, chemical, automotive and other industries due to its low cost and unique material properties like low melting point, avail- ability etc. However, the toxicity of lead during industrial production of ...

  9. Wettability alteration properties of fluorinated silica nanoparticles in liquid-loaded pores: An atomistic simulation

    Science.gov (United States)

    Sepehrinia, Kazem; Mohammadi, Aliasghar

    2016-05-01

    Control over the wettability of reservoir rocks is of crucial importance for enhancing oil and gas recovery. In order to develop chemicals for controlling the wettability of reservoir rocks, we present a study of functionalized silica nanoparticles as candidates for wettability alteration and improved gas recovery applications. In this paper, properties of fluorinated silica nanoparticles were investigated in water or decane-loaded pores of mineral silica using molecular dynamics simulation. Trifluoromethyl groups as water and oil repellents were placed on the nanoparticles. Simulating a pore in the presence of trapped water or decane molecules leads to liquid bridging for both of the liquids. Adsorption of nanoparticles on the pore wall reduces the density of liquid molecules adjacent to the wall. The density of liquid molecules around the nanoparticles decreases significantly with increasing the number of trifluoromethyl groups on the nanoparticles' surfaces. An increased hydrophobicity of the pore wall was observed in the presence of adsorbed fluorinated silica nanoparticles. Also, it is observed that increasing the number of the trifluoromethyl groups results in weakening of liquid bridges. Moreover, the free energy of adsorption on mineral surface was evaluated to be more favorable than that of aggregation of nanoparticles, which suggests nanoparticles adsorb preferably on mineral surface.

  10. Direct pore-scale reactive transport modelling of dynamic wettability changes induced by surface complexation

    Science.gov (United States)

    Maes, Julien; Geiger, Sebastian

    2018-01-01

    Laboratory experiments have shown that oil production from sandstone and carbonate reservoirs by waterflooding could be significantly increased by manipulating the composition of the injected water (e.g. by lowering the ionic strength). Recent studies suggest that a change of wettability induced by a change in surface charge is likely to be one of the driving mechanism of the so-called low-salinity effect. In this case, the potential increase of oil recovery during waterflooding at low ionic strength would be strongly impacted by the inter-relations between flow, transport and chemical reaction at the pore-scale. Hence, a new numerical model that includes two-phase flow, solute reactive transport and wettability alteration is implemented based on the Direct Numerical Simulation of the Navier-Stokes equations and surface complexation modelling. Our model is first used to match experimental results of oil droplet detachment from clay patches. We then study the effect of wettability change on the pore-scale displacement for simple 2D calcite micro-models and evaluate the impact of several parameters such as water composition and injected velocity. Finally, we repeat the simulation experiments on a larger and more complex pore geometry representing a carbonate rock. Our simulations highlight two different effects of low-salinity on oil production from carbonate rocks: a smaller number of oil clusters left in the pores after invasion, and a greater number of pores invaded.

  11. In situ characterization of wettability alteration and displacement mechanisms governing recovery enhancement due to low-salinity waterflooding

    Science.gov (United States)

    Khishvand, M.; Alizadeh, A. H.; Oraki Kohshour, I.; Piri, M.; Prasad, R. S.

    2017-05-01

    A series of micro-scale core-flooding experiments were performed on reservoir core samples at elevated temperature and pressure conditions to develop better insights into wettability alteration and pore-scale displacement mechanisms taking place during low-salinity waterflooding (LSWF). Two individual miniature core samples were cut from a preserved reservoir whole core, saturated to establish initial reservoir fluid saturation conditions, and subsequently waterflooded with low-salinity and high-salinity brines. A third miniature sister core sample was also cut, solvent-cleaned, and subjected to a dynamic wettability restoration process (to reestablish native state wettability) and then a low-salinity waterflood. All samples were imaged during the experiments using a micro-CT scanner to obtain fluid occupancy maps and measure in situ oil-water contact angles. The results of the experiments performed on the preserved core samples show a significantly improved performance of low-salinity waterflooding compared to that of high-salinity waterflooding (HSWF). Pore-scale contact angle measurements provide direct evidence of wettability alteration from weakly oil-wet toward weakly water-wet conditions during LSWF, whereas contact angles measured during HSWF remain unchanged. We believe that the reduction in oil-water contact angles toward increased water-wetness lowers the threshold water pressure needed to displace oil from some medium-sized pore elements. Contact angles measured during the dynamic wettability restoration process show an equilibrium wettability state very similar to the initial one observed in the preserved samples. This indicates that drilling fluid contaminants had a negligible effect on the reservoir rock wettability. The experimental results also reveal similarities between saturation trends for the preserved-LSWF and restored-LSWF tests.

  12. Wettability and Oil Recovery by Imbibition and Viscous Displacement from Fractured and Heterogeneous Carbonates

    Energy Technology Data Exchange (ETDEWEB)

    Norman R. Morrow; Jill Buckley

    2006-04-01

    About one-half of U.S. oil reserves are held in carbonate formations. The remaining oil in carbonate reservoirs is regarded as the major domestic target for improved oil recovery. Carbonate reservoirs are often fractured and have great complexity even at the core scale. Formation evaluation and prediction is often subject to great uncertainty. This study addresses quantification of crude oil/brine/rock interactions and the impact of reservoir heterogeneity on oil recovery by spontaneous imbibition and viscous displacement from pore to field scale. Wettability-alteration characteristics of crude oils were measured at calcite and dolomite surfaces and related to the properties of the crude oils through asphaltene content, acid and base numbers, and refractive index. Oil recovery was investigated for a selection of limestones and dolomites that cover over three orders of magnitude in permeability and a factor of four variation in porosity. Wettability control was achieved by adsorption from crude oils obtained from producing carbonate reservoirs. The induced wettability states were compared with those measured for reservoir cores. The prepared cores were used to investigate oil recovery by spontaneous imbibition and viscous displacement. The results of imbibition tests were used in wettability characterization and to develop mass transfer functions for application in reservoir simulation of fractured carbonates. Studies of viscous displacement in carbonates focused on the unexpected but repeatedly observed sensitivity of oil recovery to injection rate. The main variables were pore structure, mobility ratio, and wettability. The potential for improved oil recovery from rate-sensitive carbonate reservoirs by increased injection pressure, increased injectivity, decreased well spacing or reduction of interfacial tension was evaluated.

  13. Wettability alteration of sandstones by silica nanoparticle dispersions in light and heavy crude oil

    Science.gov (United States)

    Huibers, Britta M. J.; Pales, Ashley R.; Bai, Lingyun; Li, Chunyan; Mu, Linlin; Ladner, David; Daigle, Hugh; Darnault, Christophe J. G.

    2017-09-01

    Unlike conventional oil production methods, enhanced oil recovery (EOR) processes can recover most oil products from the reservoir. One method, known as wettability alteration, changes the hydrophilicity of the reservoir rock via decreased surface interactions with crude oils. The mitigation of these attractive forces enhances petroleum extraction and increases the accessibility of previously inaccessible rock deposits. In this work, silica nanoparticles (NPs) have been used to alter the wettability of two sandstone surfaces, Berea and Boise. Changes in wettability were assessed by measuring the contact angle and interfacial tension of different systems. The silica NPs were suspended in brine and a combined solution of brine and the Tween®20 nonionic surfactant at concentrations of 0, 0.001, and 0.01 wt% NP with both light and heavy crude oil. The stability of the different nanofluids was characterized by the size, zeta potential, and sedimentation of the particles in suspension. Unlike the NPs, the surfactant had a greater effect on the interfacial tension by influencing the liquid-liquid interactions. The introduction of the surfactant decreased the interfacial tension by 57 and 43% for light and heavy crude oil samples, respectively. Imaging and measurements of the contact angle were used to assess the surface-liquid interactions and to characterize the wettability of the different systems. The images reflect that the contact angle increased with the addition of NPs for both sandstone and oil types. The contact angle in the light crude oil sample was most affected by the addition of 0.001 wt% NP, which altered both sandstones' wettability. Increases in contact angle approached 101.6% between 0 and 0.001 wt% NPs with light oil on the Berea sandstone. The contact angle however remained relatively unaffected by addition of higher NP concentrations, thus indicating that low NP concentrations can effectively be used for enhancing crude oil recovery. While the

  14. The dynamics of liquid drops and their interaction with solids of varying wettabilities

    KAUST Repository

    Sprittles, J. E.

    2012-01-01

    Microdrop impact and spreading phenomena are explored as an interface formation process using a recently developed computational framework. The accuracy of the results obtained from this framework for the simulation of high deformation free-surface flows is confirmed by a comparison with previous numerical studies for the large amplitude oscillations of free liquid drops. Our code\\'s ability to produce high resolution benchmark calculations for dynamic wetting flows is then demonstrated by simulating microdrop impact and spreading on surfaces of greatly differing wettability. The simulations allow one to see features of the process which go beyond the resolution available to experimental analysis. Strong interfacial effects which are observed at the microfluidic scale are then harnessed by designing surfaces of varying wettability that allow new methods of flow control to be developed. © 2012 American Institute of Physics.

  15. Continuum-based DFN-consistent numerical framework for the simulation of oxygen infiltration into fractured crystalline rocks

    Science.gov (United States)

    Trinchero, Paolo; Puigdomenech, Ignasi; Molinero, Jorge; Ebrahimi, Hedieh; Gylling, Björn; Svensson, Urban; Bosbach, Dirk; Deissmann, Guido

    2017-05-01

    We present an enhanced continuum-based approach for the modelling of groundwater flow coupled with reactive transport in crystalline fractured rocks. In the proposed formulation, flow, transport and geochemical parameters are represented onto a numerical grid using Discrete Fracture Network (DFN) derived parameters. The geochemical reactions are further constrained by field observations of mineral distribution. To illustrate how the approach can be used to include physical and geochemical complexities into reactive transport calculations, we have analysed the potential ingress of oxygenated glacial-meltwater in a heterogeneous fractured rock using the Forsmark site (Sweden) as an example. The results of high-performance reactive transport calculations show that, after a quick oxygen penetration, steady state conditions are attained where abiotic reactions (i.e. the dissolution of chlorite and the homogeneous oxidation of aqueous iron(II) ions) counterbalance advective oxygen fluxes. The results show that most of the chlorite becomes depleted in the highly conductive deformation zones where higher mineral surface areas are available for reactions.

  16. Continuum-based DFN-consistent numerical framework for the simulation of oxygen infiltration into fractured crystalline rocks.

    Science.gov (United States)

    Trinchero, Paolo; Puigdomenech, Ignasi; Molinero, Jorge; Ebrahimi, Hedieh; Gylling, Björn; Svensson, Urban; Bosbach, Dirk; Deissmann, Guido

    2017-05-01

    We present an enhanced continuum-based approach for the modelling of groundwater flow coupled with reactive transport in crystalline fractured rocks. In the proposed formulation, flow, transport and geochemical parameters are represented onto a numerical grid using Discrete Fracture Network (DFN) derived parameters. The geochemical reactions are further constrained by field observations of mineral distribution. To illustrate how the approach can be used to include physical and geochemical complexities into reactive transport calculations, we have analysed the potential ingress of oxygenated glacial-meltwater in a heterogeneous fractured rock using the Forsmark site (Sweden) as an example. The results of high-performance reactive transport calculations show that, after a quick oxygen penetration, steady state conditions are attained where abiotic reactions (i.e. the dissolution of chlorite and the homogeneous oxidation of aqueous iron(II) ions) counterbalance advective oxygen fluxes. The results show that most of the chlorite becomes depleted in the highly conductive deformation zones where higher mineral surface areas are available for reactions. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Wettability between molten slag and dolomitic refractory

    OpenAIRE

    Shen, Ping; Zhang, Lifeng; Wang, Yi; Sridhar, Seetharaman; Wang, Qiangqiang

    2016-01-01

    In the current study, the wettability between molten slag and dolomitic refractory materials used in the ladle during steel refining was investigated. The contact angle between molten slag and dolomitic substrate decreased with increasing temperature. The slag with lower basicity spread on the substrate more easily and penetrated deeper into the substrate. The penetration depth of slag into the refractory increased with the extension of holding time. The CaO in the refractory dissolved into s...

  18. Wettability Improvement with Enzymes: Application to Enhanced Oil Recovery under Conditions of the North Sea Reservoirs

    DEFF Research Database (Denmark)

    Khusainova, Alsu; Shapiro, Alexander; Stenby, Erling Halfdan

    2012-01-01

    , proteases and oxidoreductases, provided by Novozymes, have been investigated. Two commercial mixtures containing enzymes: Apollo-GreenZyme™ and EOR-ZYMAX™ have also been applied. The North Sea dead oil and the synthetic sea water were used as test fluids. Internal surface of a carbonate rock has been...... interfacially active oil compounds. Application of the commercial product Apollo-GreenZyme™ has also resulted in positive wettability changes, but according to the observations the working mechanisms are different. In an attempt to assess validity of the proposed mechanisms, the reference experiments have been...

  19. Hydrophobically associated polymers for wettability alteration and enhanced oil recovery – Article review

    Directory of Open Access Journals (Sweden)

    A.N. El-hoshoudy

    2017-09-01

    Full Text Available Crude oil and other petroleum products are crucial to the global economy today due to increasing energy demand approximately (∼1.5% per year and significant oil remaining after primary and secondary oil recovery (∼45–55% of original oil in place, OOIP, which accelerates the development of enhanced oil recovery (EOR technologies to maximize the recovered oil amount by non-conventional methods as polymer flooding. This review discusses enhanced oil recovery methods specially polymer flooding techniques and their effects on rock wettability alteration.

  20. Metal oxide-based nanoparticles: revealing their potential to enhance oil recovery in different wettability systems

    Science.gov (United States)

    Hendraningrat, Luky; Torsæter, Ole

    2015-02-01

    This paper presents systematic studies of hydrophilic metal oxide nanoparticles (NPs) dispersed in brine intended to reveal their potential to enhance oil recovery (EOR) in various rock wettability systems. The stability in suspension (nanofluid) of the NPs has been identified as a key factor related to their use as an EOR agent. Experimental techniques have been developed for nanofluid stability using three coupled methods: direct visual observation, surface conductivity and particle size measurements. The use of a dispersant has been investigated and has been shown to successfully improve metal oxide nanofluid stability as a function of its concentration. The dispersant alters the nanofluid properties, i.e. surface conductivity, pH and particle size distribution. A two-phase coreflood experiment was conducted by injecting the stable nanofluids as a tertiary process (nano-EOR) through core plugs with various wettabilities ranging from water-wet to oil-wet. The combination of metal oxide nanofluid and dispersant improved the oil recovery to a greater extent than either silica-based nanofluid or dispersant alone in all wettability systems. The contact angle, interfacial tension (IFT) and effluent were also measured. It was observed that metal oxide-based nanofluids altered the quartz plates to become more water-wet, and the results are consistent with those of the coreflood experiment. The particle adsorption during the transport process was identified from effluent analysis. The presence of NPs and dispersant reduced the IFT, but its reduction is sufficient to yield significant additional oil recovery. Hence, wettability alteration plays a dominant role in the oil displacement mechanism using nano-EOR.

  1. Testing of the wettability during brazing

    Directory of Open Access Journals (Sweden)

    Alin Asavei

    2008-10-01

    Full Text Available This paper aims to present the process of brazing using laser, with the goal of determining the wettability resulted from the brazing process. For the experimental work there was applied only one type of brasing alloy on two different zinc plated sheets. The results of the experiments carried out revealed that the quality of the zinc layer may lead to different behyaviour of the sample surface during the brazing process. Moreover, there was observed that the obtained contact angle is inversely proportional to the advancing speed of the table from the laser device.

  2. Relative wettability alteration of calcite surfaces

    Science.gov (United States)

    Prabhakar, Sanjay; Liu, Jian; Pantelides, Sokrates

    Enhancement of crude oil recovery from calcite reservoirs remains a major challenge in the oil industry. Crude oil recovery can be enhanced by modifying the relative wettability of calcite reservoirs by injecting sea water. In this work, we consider acetic acid as a model component of crude oil and use the changes of adsorption energies of oil and water molecules induced by additives as a measure of relative wettability alteration of the calcite surface. More specifically, we investigate the influence of Na+, Mg2+, Ca2+, SO42- and Cl- ions on the adsorption energies of water and acetic acid. It is expected that crude oil recovery is enhanced if the modified acetic acid molecule binds weaker than acetic acid. We use density functional theory calculations and show that the presence of Na+ ions reduces oil recovery whereas the presence of Mg and SO4 ions enhance oil recovery. Additionally, we propose a novel possibility of lifting two oil molecules by one Mg2+ ion, which yields enhanced oil recovery, as observed. We also found that Cl merely binds to the surface and has no effect on the adsorption energy of acetic acid, which means that Cl has no effect on oil recovery. This work was supported by a Grant from the Petroleum Institute of Abu Dhabi.

  3. Pool boiling of nanoparticle-modified surface with interlaced wettability

    KAUST Repository

    Hsu, Chin-Chi

    2012-01-01

    This study investigated the pool boiling heat transfer under heating surfaces with various interlaced wettability. Nano-silica particles were used as the coating element to vary the interlaced wettability of the surface. The experimental results revealed that when the wettability of a surface is uniform, the critical heat flux increases with the more wettable surface; however, when the wettability of a surface is modified interlacedly, regardless of whether the modified region becomes more hydrophilic or hydrophobic, the critical heat flux is consistently higher than that of the isotropic surface. In addition, this study observed that critical heat flux was higher when the contact angle difference between the plain surface and the modified region was smaller. © 2012 Hsu et al.

  4. Wettability alteration in petroleum systems: the role of polar non-hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, B.; Larter, S.R. [Calgary Univ., Alberta (Canada). Dept. of Geology and Geophysics; Buckman, J.O. [Heriot-Watt Univ., Edinburgh (United Kingdom). Dept. of Petroluem Engineering; Bowler, B.F.J. [Newcastle upon Tyne Univ. (United Kingdom). School of Civil Engineering and Geosciences

    2004-07-01

    Compositional changes amongst surface active components of petroleum are brought about by crude oil/brine/rock interactions. The behaviour of petroleum components following simulated petroleum migration through an initially water-saturated continuous siltstone (89.7 cm x 5 cm) core was investigated. A suite of produced oils and core extract petroleum from the core-flood experiment were analysed by Iatroscan and Gas Chromatography-Mass Spectrometry (GC-MS). Dramatic changes were observed in the composition and distributions of polar non-hydrocarbons, namely, fluoren-9-ones, carbazoles, benzocarbazoles and C0 -C3 phenols indicating varying degrees of surface activity within the core-flood system. Following flooding, environmental scanning electron microscopy (ESEM) was used to view water condensation behaviour on freshly exposed core chips. Samples prepared from the original unflooded core and core material sectioned towards the outlet of the core flood displayed surfaces exhibiting hydrophilic tendencies. Meanwhile, hydrophobic behaviour was observed in a sample from the core inlet. The ESEM descriptions of the interaction of water on core surfaces appear to be consistent with the compositional changes encountered in the core extract petroleum. Wettability was altered most strongly at the core inlet where surface active compounds are rapidly removed from the migrating petroleum. In particular, small hydrophilic moieties, such as alkylphenols, appear to rapidly precondition mineral surfaces, changing wettability and subsequently allowing larger hydrophobicmolecules to sorb. Hence, petroleum surface active compounds are capable of rapidly (days to months) facilitating wettability alteration in crude oil/brine/rock systems that are initially water wet. (author)

  5. Wettability alteration properties of fluorinated silica nanoparticles in liquid-loaded pores: An atomistic simulation

    Energy Technology Data Exchange (ETDEWEB)

    Sepehrinia, Kazem; Mohammadi, Aliasghar, E-mail: amohammadi@sharif.edu

    2016-05-15

    Highlights: • Properties of fluorinated silica nanoparticles were investigated in water or decane-loaded pores of mineral silica using molecular dynamics simulation. • The water or decane-loaded pores represent liquid bridging. • Addition of nanoparticles to liquid-loaded pores results in weakening of the liquid bridge. • The hydrophobicity of the pore wall increases in the presence of adsorbed fluorinated silica nanoparticles. - Abstract: Control over the wettability of reservoir rocks is of crucial importance for enhancing oil and gas recovery. In order to develop chemicals for controlling the wettability of reservoir rocks, we present a study of functionalized silica nanoparticles as candidates for wettability alteration and improved gas recovery applications. In this paper, properties of fluorinated silica nanoparticles were investigated in water or decane-loaded pores of mineral silica using molecular dynamics simulation. Trifluoromethyl groups as water and oil repellents were placed on the nanoparticles. Simulating a pore in the presence of trapped water or decane molecules leads to liquid bridging for both of the liquids. Adsorption of nanoparticles on the pore wall reduces the density of liquid molecules adjacent to the wall. The density of liquid molecules around the nanoparticles decreases significantly with increasing the number of trifluoromethyl groups on the nanoparticles’ surfaces. An increased hydrophobicity of the pore wall was observed in the presence of adsorbed fluorinated silica nanoparticles. Also, it is observed that increasing the number of the trifluoromethyl groups results in weakening of liquid bridges. Moreover, the free energy of adsorption on mineral surface was evaluated to be more favorable than that of aggregation of nanoparticles, which suggests nanoparticles adsorb preferably on mineral surface.

  6. Wettability of graphene-laminated micropillar structures

    Science.gov (United States)

    Bong, Jihye; Seo, Keumyoung; Park, Ji-Hoon; Ahn, Joung Real; Ju, Sanghyun

    2014-12-01

    The wetting control of graphene is of great interest for electronic, mechanical, architectural, and bionic applications. In this study, the wettability of graphene-laminated micropillar structures was manipulated by changing the height of graphene-laminated structures and employing the trichlorosilane (HDF-S)-based self-assembly monolayer. Graphene-laminated micropillar structures with HDF-S exhibited higher hydrophobicity (contact angle of 129.5°) than pristine graphene thin film (78.8°), pristine graphene-laminated micropillar structures (97.5°), and HDF-S self-assembled graphene thin film (98.5°). Wetting states of the graphene-laminated micropillar structure with HDF-S was also examined by using a urea solution, which flowed across the surface without leaving any residues.

  7. Rock fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Brown, W.S.; Green, S.J.; Hakala, W.W.; Hustrulid, W.A.; Maurer, W.C. (eds.)

    1976-01-01

    Experts in rock mechanics, mining, excavation, drilling, tunneling and use of underground space met to discuss the relative merits of a wide variety of rock fragmentation schemes. Information is presented on novel rock fracturing techniques; tunneling using electron beams, thermocorer, electric spark drills, water jets, and diamond drills; and rock fracturing research needs for mining and underground construction. (LCL)

  8. Effect of Calendering on Electrode Wettability in Lithium Ion Batteries

    OpenAIRE

    Yangping eSheng; Christopher R. Fell; Yong Kyu Son; Metz, Bernhard M.; Junwei eJiang; Benjamin C. Church

    2014-01-01

    Controlling the wettability between the porous electrode and the electrolyte in lithium-ion batteries can improve both the manufacturing process and the electrochemical performance of the cell. The wetting rate, which is the electrolyte transport rate in the porous electrode, can be quantified using the wetting balance. The effect of the calendering process on the wettability of anode electrodes was investigated. A graphite anode film with an as-coated thickness of 59 μm was used as baseline ...

  9. Numerical Study of the Influence of Cavity on Immiscible Liquid Transport in Varied-Wettability Fractures

    Directory of Open Access Journals (Sweden)

    Zhi Dou

    2015-01-01

    Full Text Available Field evidence indicates that cavities often occur in fractured rocks, especially in a Karst region. Once the immiscible liquid flows into the cavity, the cavity has the immiscible liquid entrapped and results in a low recovery ratio. In this paper, the immiscible liquid transport in cavity-fractures was simulated by Lattice Boltzmann Method (LBM. The interfacial and surface tensions were incorporated by Multicomponent Shan-Chen (MCSC model. Three various fracture positions were generated to investigate the influence on the irreducible nonwetting phase saturation and displacement time. The influences of fracture aperture and wettability on the immiscible liquid transport were discussed and analyzed. It was found that the cavity resulted in a long displacement time. Increasing the fracture aperture with the corresponding decrease in displacement pressure led to the long displacement time. This consequently decreased the irreducible nonwetting phase saturation. The fracture positions had a significant effect on the displacement time and irreducible saturation. The distribution of the irreducible nonwetting phase was strongly dependent on wettability and fracture position. Furthermore, this study demonstrated that the LBM was very effective in simulating the immiscible two-phase flow in the cavity-fracture.

  10. Enhanced Wettability Modification and CO2 Solubility Effect by Carbonated Low Salinity Water Injection in Carbonate Reservoirs

    Directory of Open Access Journals (Sweden)

    Ji Ho Lee

    2017-01-01

    Full Text Available Carbonated water injection (CWI induces oil swelling and viscosity reduction. Another advantage of this technique is that CO2 can be stored via solubility trapping. The CO2 solubility of brine is a key factor that determines the extent of these effects. The solubility is sensitive to pressure, temperature, and salinity. The salting-out phenomenon makes low saline brine a favorable condition for solubilizing CO2 into brine, thus enabling the brine to deliver more CO2 into reservoirs. In addition, low saline water injection (LSWI can modify wettability and enhance oil recovery in carbonate reservoirs. The high CO2 solubility potential and wettability modification effect motivate the deployment of hybrid carbonated low salinity water injection (CLSWI. Reliable evaluation should consider geochemical reactions, which determine CO2 solubility and wettability modification, in brine/oil/rock systems. In this study, CLSWI was modeled with geochemical reactions, and oil production and CO2 storage were evaluated. In core and pilot systems, CLSWI increased oil recovery by up to 9% and 15%, respectively, and CO2 storage until oil recovery by up to 24% and 45%, respectively, compared to CWI. The CLSWI also improved injectivity by up to 31% in a pilot system. This study demonstrates that CLSWI is a promising water-based hybrid EOR (enhanced oil recovery.

  11. Dynamics of water evaporation from saline porous media with mixed wettability

    Science.gov (United States)

    Bergstad, Mina; Shokri, Nima

    2016-04-01

    Understanding of the dynamics of salt transport and precipitation in porous media during evaporation is of crucial concern in various environmental and hydrological applications such as soil salinization, rock weathering, terrestrial ecosystem functioning, microbiological activities and biodiversity in vadose zone. Vegetation, plant growth and soil organisms can be severely limited in salt-affected land. This process is influenced by the complex interaction among atmospheric conditions, transport properties of porous media and properties of the evaporating solution (1-5). We investigated effects of mixed wettability conditions on salt precipitation during evaporation from saline porous media. To do so, we conducted a series of evaporation experiments with sand mixtures containing different fractions of hydrophobic grains saturated with NaCl solutions. The dynamics of salt precipitation at the surface of sand columns (mounted on digital balances to record the evaporation curves) as well as the displacement of the receding drying front (the interface between wet and partially wet zone) were recorded using an automatic imaging system at well-defined time intervals. The experiments were conducted with sand packs containing 0, 25, 40, 50, 65, and 80% fraction of hydrophobic grains. All experiments were conducted in an environmental chamber in which the relative humidity and ambient temperature were kept constant at 30% and 30 C, respectively. Our results show that partial wettability conditions had minor impacts on the evaporative mass losses from saline sand packs due to the presence of salt. This is significantly different than what is normally observed during evaporation from mixed wettability porous media saturated with pure water (6). In our experiments, increasing the fraction of hydrophobic grains did not result in any notable reduction of the evaporative mass losses from saline porous media. Our results show that the presence of hydrophobic grains on the surface

  12. Impact of Solvents Treatment on the Wettability of Froth Solids

    Science.gov (United States)

    Yang, Fan

    The purpose of this study is to investigate the impact of solvent addition to bitumen froth on the wettability of froth solids. The wettability of solids determines the transportation/partitioning of the solids between phases, which in turn affects the solids and water rejection in a Clark hot water extraction process (CHWE). The impact of solvents treatment on the wettability of froth solids was studied using both a model system and a real bitumen froth system. The vulnerabilities of four kinds of model minerals to hydrocarbon contamination/wettability alteration in different solvents were compared and discussed by considering solvent composition and mineral types. The wettability of solids extracted from the industrial froth using different solvents was also compared. The XRD analysis on these solids confirmed the partitioning behavior of solids observed in model solids system. The results from this study indicate that the composition of paraffinic/aromatic solvent in an industrial froth treatment process could be tailor-optimized to achieve a better solids/water rejection.

  13. Wettability transition of laser textured brass surfaces inside different mediums

    Science.gov (United States)

    Yan, Huangping; Abdul Rashid, Mohamed Raiz B.; Khew, Si Ying; Li, Fengping; Hong, Minghui

    2018-01-01

    Hydrophobic surface on brass has attracted intensive attention owing to its importance in scientific research and practical applications. Laser texturing provides a simple and promising method to achieve it. Reducing wettability transition time from hydrophilicity to hydrophobicity or superhydrophobicity remains a challenge. Herein, wettability transition of brass surfaces with hybrid micro/nano-structures fabricated by laser texturing was investigated by immersing the samples inside different mediums. Scanning electron microscopy, energy-dispersive X-ray analysis, X-ray photoelectron spectroscopy and surface contact angle measurement were employed to characterize surface morphology, chemical composition and wettability of the fabricated surfaces of brass samples. Wettability transition time from hydrophilicity to hydrophobicity was shortened by immersion into isopropyl alcohol for a period of 3 h as a result of the absorption and accumulation of organic substances on the textured brass surface. When the textured brass sample was immersed into sodium bicarbonate solution, flower-like structures on the sample surface played a key role in slowing down wettability transition. Moreover, it had the smallest steady state contact angle as compared to the others. This study provides a facile method to construct textured surfaces with tunable wetting behaviors and effectively extend the industrial applications of brass.

  14. Switch isotropic/anisotropic wettability via dual-scale rods

    Directory of Open Access Journals (Sweden)

    Yang He

    2014-10-01

    Full Text Available It is the first time to demonstrate the comparison of isotropic/anisotropic wettability between dual-scale micro-nano-rods and single-scale micro-rods. Inspired by the natural structures of rice leaf, a series of micro-nano-rods and micro-rods with different geometric parameters were fabricated using micro-fabrication technology. Experimental measured apparent contact angles and advancing and receding contact angles from orthogonal orientations were characterized. The difference of contact angles from orthogonal orientation on dual-scale rods was much smaller than those on single-scale rods in both static and dynamic situation. It indicated that the dual-scale micro-nano-rods showed isotropic wettability, while single-scale micro-rods showed anisotropic wettability. The switch of isotropic/anisotropic wettability could be illustrated by different wetting state and contact line moving. It offers a facial way to switch isotropic/anisotropic wettability of the surface via dual-scale or single-scale structure.

  15. Visible light guided manipulation of liquid wettability on photoresponsive surfaces

    Science.gov (United States)

    Kwon, Gibum; Panchanathan, Divya; Mahmoudi, Seyed Reza; Gondal, Mohammed A.; McKinley, Gareth H.; Varanasi, Kripa K.

    2017-04-01

    Photoresponsive titania surfaces are of great interest due to their unique wettability change upon ultraviolet light illumination. However, their applications are often limited either by the inability to respond to visible light or the need for special treatment to recover the original wettability. Sensitizing TiO2 surfaces with visible light-absorbing materials has been utilized in photovoltaic applications. Here we demonstrate that a dye-sensitized TiO2 surface can selectively change the wettability towards contacting liquids upon visible light illumination due to a photo-induced voltage across the liquid and the underlying surface. The photo-induced wettability change of our surfaces enables external manipulation of liquid droplet motion upon illumination. We show demulsification of surfactant-stabilized brine-in-oil emulsions via coalescence of brine droplets on our dye-sensitized TiO2 surface upon visible light illumination. We anticipate that our surfaces will have a wide range of applications including microfluidic devices with customizable wettability, solar-driven oil-water clean-up and demulsification technologies.

  16. Wettability of Chalk and Argillaceous Sandstones Assessed from T1/T2 Ratio

    DEFF Research Database (Denmark)

    Katika, Konstantina; Saidian, M.; Fabricius, Ida Lykke

    Low-field NMR relaxation of the fluids inside the porous rock is the result of bulk and surface relaxation of the protons inside the pore fluid. Bulk relaxation is a fluid property when the solid-fluid interaction is minimized. Surface relaxation is the result of the solid-fluid interaction related...... with water, oil or oil/water at irreducible water saturation. The T1/T2 ratio obtained from T1-T2 maps reflects the T2-shortening. We compare the T1/T2 ratio for the same type of rock, saturated with different fluids. The chalk shows high affinity for water, Berea sandstone has no clear preference for oil...... ratio can quantify the affinity between the rock and wetting pore fluid. The affinity is a measure directly linked to wettability. In order to investigate the T2-shortening, we performed T1-T2 NMR experiments on different samples of chalk, Berea sandstone, and chloritic greensand, saturated either...

  17. Ash wettability conditions splash erosion in the postfire

    Science.gov (United States)

    Gordillo-Rivero, Ángel J.; de Celis, Reyes; García-Moreno, Jorge; Jiménez-Compán, Elizabeth; Alanís, Nancy; Cerdà, Artemi; Pereira, Paulo; Zavala, Lorena M.; Jordán, Antonio

    2015-04-01

    à and Doerr, 2008; Woods and Balfour, 2008; Zavala et al., 2009). The presence of an ash layer may be ephemeral, as it often is quickly removed or redistributed by water and wind erosion, animals or traffic (Zavala et al., 2009a). Many authors have observed that the capacity of ash to protect soil depends on properties as the topography, the meteorological conditions and the thickness of ash coverage (Cerdà and Doerr, 2008; Pereira et al., 2013; Woods and Balfour, 2010; Zavala et al., 2009). Taking this into account, in this study we hypothesized that the wettability / hydrophobicity of the ash layer may have a significant effect on the soil response to splash erosion. Therefore, the aim of this study is to evaluate the dispersion of sediments produced by the impact of raindrops in function of ash wettability after a prescribed fire at plot scale. 2. MATERIAL AND METHODS In 20 November 2012, a prescribed fire was carried out in an area located in the public mount "Las Navas", near Almaden de la Plata, Sevilla (approx. 37° 50' 44.44'' N / 6° 3' 7.44''W and 428 masl). Soils are acidic and shallow, developed from acidic metamorphic rocks (schists, slates and pyrophyllites). Vegetation is dominated by shrub legumes (Calicotome villosa and several species of Ulex and Genista). The experimental area was framed and plowed to eliminate the risk of fire spreading during the experiment. Previously to burn, level staffs were installed for determination of flame height. The temperature reached in the soil was monitored during the fire by a set of six thermocouples which were buried in soil (2 cm depth) and connected to a data-logger for monitoring the topsoil temperature every 60 s. The environmental conditions were also monitored during the experiment by a mobile weather station. At the moment of the ignition, the temperature was around 20 °C and the wind speed was near 0.0 m/s. After ignition, the experimental area was allowed to burn during 2.5 h. During burning, flames

  18. Multiscale liquid drop impact on wettable and textured surfaces

    Science.gov (United States)

    Zhang, Rui; Farokhirad, Samaneh; Lee, Taehun; Koplik, Joel

    2014-08-01

    The impact of microscopic liquid drops on solids with a variety of surface characteristics is studied using numerical simulations. The focus is on relatively low impact velocities leading to bouncing or spreading drops, and the effects of wettability. Molecular dynamics and lattice Boltzmann simulation methods are used for nanometer-sized and continuum drops, respectively, and the results of the two methods are compared in terms of scaled variables. We consider surfaces which are flat, curved or pillared, with either homogeneous interactions or cross-shaped patterns of wettability. In most situations we observe similar drop behavior at both length scales; the two methods agree best at low impact velocities on wettable surfaces while discrepancies are most pronounced for strongly hydrophobic surfaces and for higher velocities.

  19. Doping-Driven Wettability of Two-Dimensional Materials: A Multiscale Theory.

    Science.gov (United States)

    Tian, Tian; Lin, Shangchao; Li, Siyu; Zhao, Lingling; Santos, Elton J G; Shih, Chih-Jen

    2017-10-27

    Engineering molecular interactions at two-dimensional (2D) materials interfaces enables new technological opportunities in functional surfaces and molecular epitaxy. Understanding the wettability of 2D materials represents the crucial first step toward quantifying the interplay between the interfacial forces and electric potential of 2D materials interfaces. Here we develop the first theoretical framework to model the wettability of the doped 2D materials by properly bridging the multiscale physical phenomena at the 2D interfaces, including (i) the change of 2D materials surface energy (atomistic scale, several angstroms), (ii) the molecular reorientation of liquid molecules adjacent to the interface (molecular scale, 10(0)-10(1) nm), and (iii) the electrical double layer (EDL) formed in the liquid phase (mesoscopic scales, 10(0)-10(4) nm). The latter two effects are found to be the major mechanisms responsible for the contact angle change upon doping, while the surface energy change of a pure 2D material has no net effect on the wetting property. When the doping level is electrostatically tuned, we demonstrate that 2D materials with high quantum capacitances (e.g., transition metal dichalcogenides, TMDCs) possess a wider range of tunability in the interfacial tension, under the same applied gate voltage. Furthermore, practical considerations such as defects and airborne contamination are also quantitatively discussed. Our analysis implies that the doping level can be another variable to modulate the wettability at 2D materials interfaces, as well as the molecular packing behavior on a 2D material-coated surface, essentially facilitating the interfacial engineering of 2D materials.

  20. Microfluidic Dispensing Device Using Wettability Gradient and Electrowetting

    Science.gov (United States)

    Yasuda, Takashi; Harada, Shouhei; Daimon, Katsuya

    We have designed a novel microfluidic dispensing device using automatic droplet transportation on a wettability gradient surface that is sequentially followed by electrowetting-based liquid handling. While a droplet moves along the wettability gradient in a main channel, a portion of the droplet is drawn into a side channel and stored in a reservoir temporarily. Next, the stored liquid is dispensed into a mixing channel when a voltage is applied between two electrodes. The fabricated device succeeded in dispensing two liquids of different nanoscale volumes after extracting them from a microscale volume droplet.

  1. Absorption mechanism study of benzoic acid on calcite. Influence on the wettability; Etude du mecanisme d`absorption de l`acide benzoique sur la calcite. Incidence sur la mouillabilite

    Energy Technology Data Exchange (ETDEWEB)

    Legens, Ch.

    1997-12-03

    A pure carbonate rock is strongly water-wet whereas oil accumulations study shows that most of carbonate reservoirs are oil-wet or of mixed-wettability. This is one of the main difficulties to extract crude oil. This change of behavior is due to the adsorption of some crude oil compounds on the mineral surface. We have mainly studied the interactions between acid molecules by adsorption on a calcite powder in an organic phase (benzoic acid and lauric acid) and in an aqueous phase (benzoic acid and lauric sodium salt). The technics which enabled us to define and characterize adsorption are thermogravimetry infrared diffuse reflection and thermal analysis with controlled kinetic linked to a mass spectrometer. Molecular modelling calculations have completed these analysis. It has been showed that when crude oil fills the biggest pores of the reservoir rock, the aqueous film is unstable and acids adsorb via ionic bonds on mineral calcium ions. Wettability is evaluated thanks to contact angle measurements of a water droplet deposited on a compacted powder pellet. Calcite wettability changes were all the greater as hydro-carbonated chains were longer, as it confers molecule hydrophobia. It has been also investigated acid molecules diffusion from the organic to the aqueous phase which saturates the smallest pores. Molecules which are able to diffuse from the first to the second medium do not adsorb on the surface. As a consequence, carbonate rock wettability changes require a direct contact between crude oil and mineral that involves aqueous film instability. (author) 128 refs.

  2. Altering Reservoir Wettability to Improve Production from Single Wells

    Energy Technology Data Exchange (ETDEWEB)

    W. W. Weiss

    2006-09-30

    Many carbonate reservoirs are naturally fractured and typically produce less than 10% original oil in place during primary recovery. Spontaneous imbibition has proven an important mechanism for oil recovery from fractured reservoirs, which are usually weak waterflood candidates. In some situations, chemical stimulation can promote imbibition of water to alter the reservoir wettability toward water-wetness such that oil is produced at an economic rate from the rock matrix into fractures. In this project, cores and fluids from five reservoirs were used in laboratory tests: the San Andres formation (Fuhrman Masho and Eagle Creek fields) in the Permian Basin of Texas and New Mexico; and the Interlake, Stony Mountain, and Red River formations from the Cedar Creek Anticline in Montana and South Dakota. Solutions of nonionic, anionic, and amphoteric surfactants with formation water were used to promote waterwetness. Some Fuhrman Masho cores soaked in surfactant solution had improved oil recovery up to 38%. Most Eagle Creek cores did not respond to any of the tested surfactants. Some Cedar Creek anticline cores had good response to two anionic surfactants (CD 128 and A246L). The results indicate that cores with higher permeability responded better to the surfactants. The increased recovery is mainly ascribed to increased water-wetness. It is suspected that rock mineralogy is also an important factor. The laboratory work generated three field tests of the surfactant soak process in the West Fuhrman Masho San Andres Unit. The flawlessly designed tests included mechanical well clean out, installation of new pumps, and daily well tests before and after the treatments. Treatments were designed using artificial intelligence (AI) correlations developed from 23 previous surfactant soak treatments. The treatments were conducted during the last quarter of 2006. One of the wells produced a marginal volume of incremental oil through October. It is interesting to note that the field

  3. Wettability control on multiphase flow in patterned microfluidics.

    Science.gov (United States)

    Zhao, Benzhong; MacMinn, Christopher W; Juanes, Ruben

    2016-09-13

    Multiphase flow in porous media is important in many natural and industrial processes, including geologic CO2 sequestration, enhanced oil recovery, and water infiltration into soil. Although it is well known that the wetting properties of porous media can vary drastically depending on the type of media and pore fluids, the effect of wettability on multiphase flow continues to challenge our microscopic and macroscopic descriptions. Here, we study the impact of wettability on viscously unfavorable fluid-fluid displacement in disordered media by means of high-resolution imaging in microfluidic flow cells patterned with vertical posts. By systematically varying the wettability of the flow cell over a wide range of contact angles, we find that increasing the substrate's affinity to the invading fluid results in more efficient displacement of the defending fluid up to a critical wetting transition, beyond which the trend is reversed. We identify the pore-scale mechanisms-cooperative pore filling (increasing displacement efficiency) and corner flow (decreasing displacement efficiency)-responsible for this macroscale behavior, and show that they rely on the inherent 3D nature of interfacial flows, even in quasi-2D media. Our results demonstrate the powerful control of wettability on multiphase flow in porous media, and show that the markedly different invasion protocols that emerge-from pore filling to postbridging-are determined by physical mechanisms that are missing from current pore-scale and continuum-scale descriptions.

  4. Wettability Modification of Nanomaterials by Low-Energy Electron Flux

    Directory of Open Access Journals (Sweden)

    Torchinsky I

    2009-01-01

    Full Text Available Abstract Controllable modification of surface free energy and related properties (wettability, hygroscopicity, agglomeration, etc. of powders allows both understanding of fine physical mechanism acting on nanoparticle surfaces and improvement of their key characteristics in a number of nanotechnology applications. In this work, we report on the method we developed for electron-induced surface energy and modification of basic, related properties of powders of quite different physical origins such as diamond and ZnO. The applied technique has afforded gradual tuning of the surface free energy, resulting in a wide range of wettability modulation. In ZnO nanomaterial, the wettability has been strongly modified, while for the diamond particles identical electron treatment leads to a weak variation of the same property. Detailed investigation into electron-modified wettability properties has been performed by the use of capillary rise method using a few probing liquids. Basic thermodynamic approaches have been applied to calculations of components of solid–liquid interaction energy. We show that defect-free, low-energy electron treatment technique strongly varies elementary interface interactions and may be used for the development of new technology in the field of nanomaterials.

  5. Directional transport of droplets on wettability patterns at high temperature

    Science.gov (United States)

    Huang, Shuai; Yin, Shaohui; Chen, Fengjun; Luo, Hu; Tang, Qingchun; Song, Jinlong

    2018-01-01

    Directional transport of liquid has attracted increasing interest owing to its potential of application in lab-on-a-chip, microfluidic devices and thermal management technologies. Although numerous strategies have been developed to achieve directional transport of liquid at low temperature, controlling the directional transport of liquid at high temperature remains to be a challenging issue. In this work, we reported a novel strategy in which different parts of droplet contacted with surface with different wettability patterns, resulting in a discrepant evaporative vapor film to achieve the directional transport of liquid. The experimental results showed that the state of the liquid on wettability patterned surface gradually changed from contact boiling to Leidenfrost state with the increase of substrate temperature Ts, and liquid on superhydrophilic surface was in composite state of contact boiling and Leidenfrost when Ts was higher than 200 °C. Inspired by the different evaporation states of droplet on the wettability boundary, controlling preferential motion of droplets was observed at high temperature. By designing a surface with wettability pattern on which superhydrophobic region and superhydrophilic region are alternately arranged, a controlled directional transport of droplet can be achieved at high temperature.

  6. An investigation of factors affecting wettability of some southern hardwoods

    Science.gov (United States)

    Todd F. Shupe; Chung Y. Hse; Wan H. Wang

    1999-01-01

    >Wettability of sanded and nonsanded transverse and tangential sections of 22 southern hardwood species were[was] judged by measurement of contact angles using phenol-formaldehyde resins. As ex­pected, contact angle values on transverse sec­tions were higher than on tangential sections for both sanded and...

  7. Effect of Calendering on Electrode Wettability in Lithium Ion Batteries

    Directory of Open Access Journals (Sweden)

    Yangping eSheng

    2014-12-01

    Full Text Available Controlling the wettability between the porous electrode and the electrolyte in lithium ion batteries can improve both the manufacturing process and the electrochemical performance of the cell. The wetting rate, which is the electrolyte transport rate in the porous electrode, can be quantified using the wetting balance. The effect of the calendering process on the wettability of anode electrodes was investigated. A graphite anode film with an as-coated thickness of 59 μm was used as baseline electrode film and was calendered to produce films with thickness ranging from 55 to 41 µm. Results show that wettability is improved by light calendering from an initial thickness of 59 μm to a calendered thickness of 53 μm where the wetting rate increased from 0.375 to 0.589 mm/s0.5. Further calendering below 53 µm resulted in a decrease in wetting rates to a minimum observed value of 0.206 mm/s0.5 at a calendered thickness of 41 μm. Under the same electrolyte, wettability of the electrode is controlled to a great extent by the pore structure in the electrode film which includes parameters such as porosity, pore size distribution, pore geometry and topology. Relations between the wetting behavior and the pore structure as characterized by mercury intrusion and electron microscopy exist and can be used to manipulate the wetting behavior of electrodes.

  8. Brownian motion as a new probe of wettability

    Science.gov (United States)

    Mo, Jianyong; Simha, Akarsh; Raizen, Mark G.

    2017-04-01

    Understanding wettability is crucial for optimizing oil recovery, semiconductor manufacturing, pharmaceutical industry, and electrowetting. In this letter, we study the effects of wettability on Brownian motion. We consider the cases of a sphere in an unbounded fluid medium, as well as a sphere placed in the vicinity of a plane wall. For the first case, we show the effects of wettability on the statistical properties of the particles' motion, such as velocity autocorrelation, velocity, and thermal force power spectra over a large range of time scales. We also propose a new method to measure wettability based on the particles' Brownian motion. In addition, we compare the boundary effects on Brownian motion imposed by both no-slip and perfect-slip flat walls. We emphasize the surprising boundary effects on Brownian motion imposed by a perfect-slip wall in the parallel direction, such as a higher particle mobility parallel to a perfect flat wall compared to that in the absence of the wall, as well as compared to a particle near a no-slip flat wall.

  9. Pore-scale modeling of wettability alteration during primary drainage

    Science.gov (United States)

    Kallel, W.; van Dijke, M. I. J.; Sorbie, K. S.; Wood, R.

    2017-03-01

    While carbonate reservoirs are recognized to be weakly-to-moderately oil-wet at the core-scale, pore-scale wettability distributions remain poorly understood. In particular, the wetting state of micropores (pores polar non-hydrocarbon compounds from the oil-phase into the water-phase. We implement a diffusion/adsorption model for these compounds that triggers a wettability alteration from initially water-wet to intermediate-wet conditions. This mechanism is incorporated in a quasi-static pore-network model to which we add a notional time-dependency of the quasi-static invasion percolation mechanism. The model qualitatively reproduces experimental observations where an early rapid wettability alteration involving these small polar species occurred during primary drainage. Interestingly, we could invoke clear differences in the primary drainage patterns by varying both the extent of wettability alteration and the balance between the processes of oil invasion and wetting change. Combined, these parameters dictate the initial water saturation for waterflooding. Indeed, under conditions where oil invasion is slow compared to a fast and relatively strong wetting change, the model results in significant non-zero water saturations. However, for relatively fast oil invasion or small wetting changes, the model allows higher oil saturations at fixed maximum capillary pressures, and invasion of micropores at moderate capillary pressures.

  10. Comparative Microstructural and Wettability Studies of 63sn-37pb ...

    African Journals Online (AJOL)

    The respective wettability values (in percentage) of the total area of the copper grid covered by the molten solder are: 8.3%, and 8.6% The alloy also have the following Vicker's Hardness Values of 18.58VHN and 16.32VHN. The microstructures of the developed alloys were studied and analyzed. The alloy's microstructures ...

  11. Recreating Rocks

    DEFF Research Database (Denmark)

    Posth, Nicole R

    2008-01-01

    Nicole Posth and colleagues spent a month touring South African rock formations in their quest to understand the origin of ancient iron and silicate layers.......Nicole Posth and colleagues spent a month touring South African rock formations in their quest to understand the origin of ancient iron and silicate layers....

  12. Care solution effects on contact lens in vivo wettability.

    Science.gov (United States)

    Fagehi, Raied; Pearce, E Ian; Oliver, Katherine; Abusharha, Ali A; Tomlinson, Alan

    2017-11-01

    The aim of the study was to evaluate the effect of care solutions on contact lens in vivo wettability using Doane's interferometric technique. Thirteen subjects (aged 26.6 ± 6.3 years) participated for contact lens wettability evaluation after soaking in five care solutions namely Opti-Free EverMoist (now called puremoist), Opti-Free Express (Alcon), COMPLETE (AMO), ReNu and Biotrue (Bausch & Lomb). A new pair of lenses was soaked in the solutions for eight hours (prior to wear) or taken directly from pack solutions (as control) and worn by the subjects. The total number of pairs of lenses tested was 13 by six (78 lenses; 13 pairs of lenses wetted in five care solutions plus the pack solution). Doane's interferometer was used to capture images of the pre-lens film on a single type of contact lens, Acuvue Oasys (Johnson & Johnson). The lens in vivo wettability was evaluated after 15 minutes and eight hours of wear by each subject. Four parameters: onset latency, drying duration, maximum speed and peak latency were used to assess the lens wettability. After eight hours, the solutions showing significant reduction in contact lens wettability were the following. For onset latency: Pack solution, Biotrue Opti-Free EverMoist and Express; for drying duration: pack solution, ReNu and Opti-Free EverMoist; for peak latency; pack solution, Biotrue and Opti-Free EverMoist. Regarding the maximum speed, lenses soaked in Pack solution, ReNu and Opti-Free EverMoist showed a significant increase (worsening). The comparative study showed that there were significant differences among the performance of the care solutions. This novel thin film interferometric technique was able to measure, objectively, contact lens in vivo wettability, following the use of care solutions. COMPLETE was the only solution that showed no significant change in the lens wettability (with the all parameters) between the initial and the end of day. © 2017 Optometry Australia.

  13. Geologic framework of pre-Cretaceous rocks in the Southern Ute Indian Reservation and adjacent areas, southwestern Colorado and northwestern New Mexico

    Science.gov (United States)

    Condon, Steven M.

    1992-01-01

    This report is a discussion and summary of Jurassic and older rocks in the Southern Ute Indian Reservation and adjacent areas, southwestern Colorado and northwestern New Mexico, and is based on analysis of geophysical logs and observations of outcrops. The Reservation, which is located in the northern San Juan Basin, has been the site of deposition of sediments for much of the Phanerozoic. Geologic times represented on the Reservation are the Precambrian, Cambrian, Devonian, Mississippian, Pennsylvanian, Permian, Triassic, Jurassic, Cretaceous, Tertiary, and Quaternary. Rocks of Ordovician and Silurian age have not been reported in this region. Thicknesses of pre-Cretaceous sedimentary rocks range from about 750 feet (229 meters) on the Archuleta arch, east of the Reservation, to more than 8,300 feet (2,530 meters) just northwest of the Reservation. About 5,500 feet (1,676 meters) of pre-Cretaceous sedimentary rocks occur in the central part of the Reservation, near Ignacio. At Ignacio the top of the Jurassic lies at a depth of 7,600 feet (2,316 meters) below the surface, which is composed of Tertiary rocks. As much as 2,500 feet (762 meters) of Tertiary rocks occur in the area. More than 10,000 feet (3,048 meters) of Cretaceous and younger rocks, and 15,600 feet (4,755 meters) of all Phanerozoic sedimentary rocks occur in the vicinity of the Reservation. In the early Paleozoic the area that includes the Southern Ute Reservation was on the stable western shelf of the craton. During this time sediments that compose the following shallow-marine clastic and carbonate rocks were deposited: the Upper Cambrian Ignacio Quartzite (0-150 feet; 0-46 meters), Upper Devonian Elbert Formation (50-200 feet; 15-61 meters), Upper Devonian Ouray Limestone (10-75 feet; 3-23 meters), and Mississippian Leadville Limestone (0-250 feet; 0-76 meters). Mixed carbonate and clastic deposition, which was punctuated by a unique episode of deposition of evaporite sediments, continued through

  14. Microbial enhanced oil recovery and wettability research program

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, C.P.; Bala, G.A.; Duvall, M.L.

    1991-07-01

    This report covers research results for the microbial enhanced oil recovery (MEOR) and wettability research program conducted by EG G Idaho, Inc. at the Idaho National Engineering Laboratory (INEL). The isolation and characterization of microbial species collected from various locations including target oil field environments is underway to develop more effective oil recovery systems for specific applications. The wettability research is a multi-year collaborative effort with the New Mexico Petroleum Recovery Research Center (NMPRRC), to evaluate reservoir wettability and its effects on oil recovery. Results from the wettability research will be applied to determine if alteration of wettability is a significant contributing mechanism for MEOR systems. Eight facultatively anaerobic surfactant producing isolates able to function in the reservoir conditions of the Minnelusa A Sands of the Powder River Basin in Wyoming were isolated from naturally occurring oil-laden environments. Isolates were characterized according to morphology, thermostability, halotolerance, growth substrates, affinity to crude oil/brine interfaces, degradative effects on crude oils, and biochemical profiles. Research at the INEL has focused on the elucidation of microbial mechanisms by which crude oil may be recovered from a reservoir and the chemical and physical properties of the reservoir that may impact the effectiveness of MEOR. Bacillus licheniformis JF-2 (ATCC 39307) has been used as a benchmark organism to quantify MEOR of medium weight crude oils (17.5 to 38.1{degrees}API) the capacity for oil recovery of Bacillus licheniformis JF-2 utilizing a sucrose-based nutrient has been elucidated using Berea sandstone cores. Spacial distribution of cells after microbial flooding has been analyzed with scanning electron microscopy. Also the effect of microbial surfactants on the interfacial tensions (IFT) of aqueous/crude oil systems has been measured. 87 refs., 60 figs., 15 tabs.

  15. Art Rocks with Rock Art!

    Science.gov (United States)

    Bickett, Marianne

    2011-01-01

    This article discusses rock art which was the very first "art." Rock art, such as the images created on the stone surfaces of the caves of Lascaux and Altimira, is the true origin of the canvas, paintbrush, and painting media. For there, within caverns deep in the earth, the first artists mixed animal fat, urine, and saliva with powdered minerals…

  16. Pore-scale modeling of wettability effects on CO2-brine displacement during geological storage

    Science.gov (United States)

    Basirat, Farzad; Yang, Zhibing; Niemi, Auli

    2017-11-01

    Wetting properties of reservoir rocks and caprocks can vary significantly, and they strongly influence geological storage of carbon dioxide in deep saline aquifers, during which CO2 is supposed to displace the resident brine and to become permanently trapped. Fundamental understanding of the effect of wettability on CO2-brine displacement is thus important for improving storage efficiency and security. In this study, we investigate the influence of wetting properties on two-phase flow of CO2 and brine at the pore scale. A numerical model based on the phase field method is implemented to simulate the two-phase flow of CO2-brine in a realistic pore geometry. Our focus is to study the pore-scale fluid-fluid displacement mechanisms under different wetting conditions and to quantify the effect of wettability on macroscopic parameters such as residual brine saturation, capillary pressure, relative permeability, and specific interfacial area. Our simulation results confirm that both the trapped wetting phase saturation and the normalized interfacial area increase with decreasing contact angle. However, the wetting condition does not appear to influence the CO2 breakthrough time and saturation. We also show that the macroscopic capillary pressures based on the pressure difference between inlet and outlet can differ significantly from the phase averaging capillary pressures for all contact angles when the capillary number is high (log Ca > -5). This indicates that the inlet-outlet pressure difference may not be a good measure of the continuum-scale capillary pressure. In addition, the results show that the relative permeability of CO2 can be significantly lower in strongly water-wet conditions than in the intermediate-wet conditions.

  17. Rock Physics

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke

    2017-01-01

    Rock physics is the discipline linking petrophysical properties as derived from borehole data to surface based geophysical exploration data. It can involve interpretation of both elastic wave propagation and electrical conductivity, but in this chapter focus is on elasticity. Rock physics is based...... on continuum mechanics, and the theory of elasticity developed for statics becomes the key to petrophysical interpretation of velocity of elastic waves. In practice, rock physics involves interpretation of well logs including vertical seismic profiling (VSP) and analysis of core samples. The results...

  18. Evaluating the Influence of Pore Architecture and Initial Saturation on Wettability and Relative Permeability in Heterogeneous, Shallow-Shelf Carbonates

    Energy Technology Data Exchange (ETDEWEB)

    Byrnes, Alan P.; Bhattacharya, Saibal; Victorine, John; Stalder, Ken

    2007-09-30

    Thin (3-40 ft thick), heterogeneous, limestone and dolomite reservoirs, deposited in shallow-shelf environments, represent a significant fraction of the reservoirs in the U.S. midcontinent and worldwide. In Kansas, reservoirs of the Arbuckle, Mississippian, and Lansing-Kansas City formations account for over 73% of the 6.3 BBO cumulative oil produced over the last century. For these reservoirs basic petrophysical properties (e.g., porosity, absolute permeability, capillary pressure, residual oil saturation to waterflood, resistivity, and relative permeability) vary significantly horizontally, vertically, and with scale of measurement. Many of these reservoirs produce from structures of less than 30-60 ft, and being located in the capillary pressure transition zone, exhibit vertically variable initial saturations and relative permeability properties. Rather than being simpler to model because of their small size, these reservoirs challenge characterization and simulation methodology and illustrate issues that are less apparent in larger reservoirs where transition zone effects are minor and most of the reservoir is at saturations near S{sub wirr}. These issues are further augmented by the presence of variable moldic porosity and possible intermediate to mixed wettability and the influence of these on capillary pressure and relative permeability. Understanding how capillary-pressure properties change with rock lithology and, in turn, within transition zones, and how relative permeability and residual oil saturation to waterflood change through the transition zone is critical to successful reservoir management and as advanced waterflood and improved and enhanced recovery methods are planned and implemented. Major aspects of the proposed study involve a series of tasks to measure data to reveal the nature of how wettability and drainage and imbibition oil-water relative permeability change with pore architecture and initial water saturation. Focus is placed on

  19. Evaluation of Reservoir Wettability and its Effect on Oil Recovery

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, Jill S.

    1999-07-01

    The objective of this five-year project are: (1) to achieve improved understanding of the surface and interfacial properties of crude oils and their interactions with mineral surfaces, (2) to apply the results of surface studies to improve predictions of oil production from laboratory measurements, and (3) to use the results of this research to recommend ways to improve oil recovery by waterflooding. During the second year of this project we have tested the generality of the proposed mechanisms by which crude oil components can alter wetting. Using these mechanisms, we have begun a program of characterizing crude oils with respect to their wettability altering potential. Wettability assessment has been improved by replacing glass with mica as a standard surface material and crude oils have been used to alter wetting in simple square glass capillary tubes in which the subsequent imbibition of water can be followed visually.

  20. Conductive Polymer Porous Film with Tunable Wettability and Adhesion

    Directory of Open Access Journals (Sweden)

    Yuqi Teng

    2015-04-01

    Full Text Available A conductive polymer porous film with tunable wettability and adhesion was fabricated by the chloroform solution of poly(3-hexylthiophene (P3HT and [6,6]-phenyl-C61-butyricacid-methyl-ester (PCBM via the freeze drying method. The porous film could be obtained from the solution of 0.8 wt%, whose pore diameters ranged from 50 nm to 500 nm. The hydrophobic porous surface with a water contact angle (CA of 144.7° could be transferred into a hydrophilic surface with CA of 25° by applying a voltage. The water adhesive force on the porous film increased with the increase of the external voltage. The electro-controllable wettability and adhesion of the porous film have potential application in manipulating liquid collection and transportation.

  1. Wettability of southern pine veneer by phenol formaldehyde wood adhesives

    Science.gov (United States)

    Chung-Yun Hse

    1972-01-01

    Wettability of southern pine veneers was judged by measuring the contact angles made by 36 phenol formaldehyde resins. Formulation of the resins was by factorial design, the molar ratios of sodium hydroxide to phenol being 0.4, 0.7, and 1.0, the levels of resin solids content in the reaction mixture 37, 40, and 43 percent, and the molar ratios of formaldehyde to phenol...

  2. Evaluation of wettability of binders used in moulding sands

    Directory of Open Access Journals (Sweden)

    Hutera B.

    2007-01-01

    Full Text Available Binders used in moulding sand have the differential properties. One of the main parameters influencing on moulding sand properties is wettability of the sand grain by binding material. In the article some problems concerned with wettability evaluation have been presented and the importance of this parameter for quantity description of process occurring in system: binder- sand grain has been mentioned. The procedure of wetting angle measurement and operation of prototype apparatus for wettability investigation of different binders used in moulding sand have been described, as well as the results of wetting angle measurement for different binders at different conditions. The addition of little amount of proper diluent to binder results in the state of equilibrium reached almost immediately. Such addition can also reduce the value of equilibrium contact angle. The uniform distribution of binder on the surface of the sand grains and reducing of the required mixing time can be obtained. It has also a positive effect on the moulding sand strength.

  3. Photoresponsive wettability in monolayer films from sinapinic acid.

    Science.gov (United States)

    Moura, Cleverson A S; Gomes, Douglas J C; de Souza, Nara C; Silva, Josmary R

    2013-01-01

    Sinapinic acid is an interesting material because it is both antioxidant and antibacterial agent. In addition, when illuminated with ultraviolet light, it can exhibit the so-called photodimerization process. In this paper, we report on the investigation of monolayer films from 3,5-dimethoxy-4-hydroxycinnamic acid (sinapinic acid, SinA) deposited onto poly(allylamine hydrochloride), PAH, films. SinA monolayers were prepared by using the layer-by-layer (LbL) self-assembly technique. Adsorption kinetics curves were well fitted by a biexponential function suggesting that the adsorption process is determined by two mechanisms: nucleation and growth of aggregates. By using wetting contact angle analysis, we have found that SinA monolayers exhibit photoresponsive wettability under UV irradiation (365 nm); that is, wettability decreases with increasing UV irradiation time. The photoresponse of wettability was attributed to photodimerization process. This hypothesis was supported by the dependence of surface morphological structure and absorption on UV irradiation time. The mechanism found in the well-known transcinnamic acid crystals is used to explain the photodimerization process in SinA monolayers.

  4. Photoresponsive Wettability in Monolayer Films from Sinapinic Acid

    Directory of Open Access Journals (Sweden)

    Cleverson A. S. Moura

    2013-01-01

    Full Text Available Sinapinic acid is an interesting material because it is both antioxidant and antibacterial agent. In addition, when illuminated with ultraviolet light, it can exhibit the so-called photodimerization process. In this paper, we report on the investigation of monolayer films from 3,5-dimethoxy-4-hydroxycinnamic acid (sinapinic acid, SinA deposited onto poly(allylamine hydrochloride, PAH, films. SinA monolayers were prepared by using the layer-by-layer (LbL self-assembly technique. Adsorption kinetics curves were well fitted by a biexponential function suggesting that the adsorption process is determined by two mechanisms: nucleation and growth of aggregates. By using wetting contact angle analysis, we have found that SinA monolayers exhibit photoresponsive wettability under UV irradiation (365 nm; that is, wettability decreases with increasing UV irradiation time. The photoresponse of wettability was attributed to photodimerization process. This hypothesis was supported by the dependence of surface morphological structure and absorption on UV irradiation time. The mechanism found in the well-known transcinnamic acid crystals is used to explain the photodimerization process in SinA monolayers.

  5. WETTABILITY AND IMBIBITION: MICROSCOPIC DISTRIBUTION OF WETTING AND ITS CONSEQUENCES AT THE CORE AND FIELD SCALES

    Energy Technology Data Exchange (ETDEWEB)

    Jill S. Buckley; Norman R. Morrow; Chris Palmer; Purnendu K. Dasgupta

    2003-02-01

    The questions of reservoir wettability have been approached in this project from three directions. First, we have studied the properties of crude oils that contribute to wetting alteration in a reservoir. A database of more than 150 different crude oil samples has been established to facilitate examination of the relationships between crude oil chemical and physical properties and their influence on reservoir wetting. In the course of this work an improved SARA analysis technique was developed and major advances were made in understanding asphaltene stability including development of a thermodynamic Asphaltene Solubility Model (ASM) and empirical methods for predicting the onset of instability. The CO-Wet database is a resource that will be used to guide wettability research in the future. The second approach is to study crude oil/brine/rock interactions on smooth surfaces. Contact angle measurements were made under controlled conditions on mica surfaces that had been exposed to many of the oils in the CO-Wet database. With this wealth of data, statistical tests can now be used to examine the relationships between crude oil properties and the tendencies of those oils to alter wetting. Traditionally, contact angles have been used as the primary wetting assessment tool on smooth surfaces. A new technique has been developed using an atomic forces microscope that adds a new dimension to the ability to characterize oil-treated surfaces. Ultimately we aim to understand wetting in porous media, the focus of the third approach taken in this project. Using oils from the CO-Wet database, experimental advances have been made in scaling the rate of imbibition, a sensitive measure of core wetting. Application of the scaling group to mixed-wet systems has been demonstrated for a range of core conditions. Investigations of imbibition in gas/liquid systems provided the motivation for theoretical advances as well. As a result of this project we have many new tools for studying

  6. Source rock

    Directory of Open Access Journals (Sweden)

    Abubakr F. Makky

    2014-03-01

    Full Text Available West Beni Suef Concession is located at the western part of Beni Suef Basin which is a relatively under-explored basin and lies about 150 km south of Cairo. The major goal of this study is to evaluate the source rock by using different techniques as Rock-Eval pyrolysis, Vitrinite reflectance (%Ro, and well log data of some Cretaceous sequences including Abu Roash (E, F and G members, Kharita and Betty formations. The BasinMod 1D program is used in this study to construct the burial history and calculate the levels of thermal maturity of the Fayoum-1X well based on calibration of measured %Ro and Tmax against calculated %Ro model. The calculated Total Organic Carbon (TOC content from well log data compared with the measured TOC from the Rock-Eval pyrolysis in Fayoum-1X well is shown to match against the shale source rock but gives high values against the limestone source rock. For that, a new model is derived from well log data to calculate accurately the TOC content against the limestone source rock in the study area. The organic matter existing in Abu Roash (F member is fair to excellent and capable of generating a significant amount of hydrocarbons (oil prone produced from (mixed type I/II kerogen. The generation potential of kerogen in Abu Roash (E and G members and Betty formations is ranging from poor to fair, and generating hydrocarbons of oil and gas prone (mixed type II/III kerogen. Eventually, kerogen (type III of Kharita Formation has poor to very good generation potential and mainly produces gas. Thermal maturation of the measured %Ro, calculated %Ro model, Tmax and Production index (PI indicates that Abu Roash (F member exciting in the onset of oil generation, whereas Abu Roash (E and G members, Kharita and Betty formations entered the peak of oil generation.

  7. Scattering from Rock and Rock Outcrops

    Science.gov (United States)

    2015-09-30

    Scattering from Rock and Rock Outcrops Derek R. Olson The Pennsylvania State University Applied Research Laboratory, P.O. Box 30 State...In terms of target detection and classification, scattering from exposed rock on the seafloor, (i.e., individual rocks and rock outcrops) presents...levels, and other statistical measures of acoustic scattering from rocks and rock outcrops is therefore critical. Unfortunately (and curiously

  8. Wettability testing of unconsolidated oil sands using low field NMR technology

    Energy Technology Data Exchange (ETDEWEB)

    Ji, X.; Kantzas, A.; Bryan, J. [University of Calgary/TIPM Laboratory (Canada)

    2011-07-01

    In an oil field it is important to understand wettability within the reservoir as it has an important impact on several parameters. However it is difficult to measure wettability in oil sands since conventional Amott/USBM testing cannot be applied. The aim of this paper is to develop protocols to assess wettability from NMR spectra in heavy oil reservoirs. Research was conducted on water wet and oil wet conditions; 3 sets of experiments were carried out with oil phases of different viscosity. Results showed that the signal from oil is insensitive to the location of the oil when viscosity increases but that water relaxation times are linked to the presence of water so water peak shifts can be used to determine different wettability states. This study determined that using water phase NMR relaxation presents several advantages to extract wettability information in unconsolidated sand systems and a technique was developed to interpret wettability.

  9. Wettability transition of plasma-treated polystyrene micro/nano pillars-aligned patterns

    Directory of Open Access Journals (Sweden)

    2010-12-01

    Full Text Available This paper reports the wettability transition of plasma-treated polystyrene (PS micro/nano pillars-aligned patterns. The micro/nano pillars were prepared using hot embossing on silicon microporous template and alumina nanoporous template, which were fabricated by ultraviolet (UV lithography and inductive coupled plasma (ICP etching, and two-step anodic oxidation, respectively. The results indicate that the combination of micro/nano patterning and plasma irradiation can easily regulate wettabilities of PS surfaces, i.e. from hydrophilicity to hydrophobicity, or from hydrophobicity to superhydrophilicity. During the wettability transition from hydrophobicity to hydrophilicity there is only mild hydrophilicity loss. After plasma irradiation, moreover, the wettability of PS micro/nano pillars-aligned patterns is more stable than that of flat PS surfaces. The observed wettability transition and wettability stability of PS micro/nano pillars-aligned patterns are new phenomena, which may have potential in creating programmable functional polymer surfaces.

  10. Study of Surface Wettability Change of Unconsolidated Sand Using Diffuse Reflectance Infrared Fourier Transform Spectroscopy and Thermogravimetric Analysis.

    Science.gov (United States)

    Gómora-Herrera, Diana; Navarrete Bolaños, Juan; Lijanova, Irina V; Olivares-Xometl, Octavio; Likhanova, Natalya V

    2018-01-01

    The effects exerted by the adsorption of vapors of a non-polar compound (deuterated benzene) and a polar compound (water) on the surface of Ottawa sand and a sample of reservoir sand (Channel), which was previously impregnated with silicon oil or two kinds of surfactants, (2-hydroxyethyl) trimethylammonium oleate (HETAO) and (2-hydroxyethyl)trimethylammonium azelate (HETAA), were studied by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and thermogravimetric analysis (TGA). The surface chemistry of the sandstone rocks was elucidated by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX). Terminal surface groups such as hydroxyls can strongly adsorb molecules that interact with these surface groups (surfactants), resulting in a wettability change. The wettability change effect suffered by the surface after treating it with surfactants was possible to be detected by the DRIFTS technique, wherein it was observed that the surface became more hydrophobic after being treated with silicon oil and HETAO; the surface became more hydrophilic after treating it with HETAA.

  11. Effect of wettability on scale-up of multiphase flow from core-scale to reservoir fine-grid-scale

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Y.C.; Mani, V.; Mohanty, K.K. [Univ. of Houston, TX (United States)

    1997-08-01

    Typical field simulation grid-blocks are internally heterogeneous. The objective of this work is to study how the wettability of the rock affects its scale-up of multiphase flow properties from core-scale to fine-grid reservoir simulation scale ({approximately} 10{prime} x 10{prime} x 5{prime}). Reservoir models need another level of upscaling to coarse-grid simulation scale, which is not addressed here. Heterogeneity is modeled here as a correlated random field parameterized in terms of its variance and two-point variogram. Variogram models of both finite (spherical) and infinite (fractal) correlation length are included as special cases. Local core-scale porosity, permeability, capillary pressure function, relative permeability functions, and initial water saturation are assumed to be correlated. Water injection is simulated and effective flow properties and flow equations are calculated. For strongly water-wet media, capillarity has a stabilizing/homogenizing effect on multiphase flow. For small variance in permeability, and for small correlation length, effective relative permeability can be described by capillary equilibrium models. At higher variance and moderate correlation length, the average flow can be described by a dynamic relative permeability. As the oil wettability increases, the capillary stabilizing effect decreases and the deviation from this average flow increases. For fractal fields with large variance in permeability, effective relative permeability is not adequate in describing the flow.

  12. Biomedical devices engineered based on the control of the surface wettability

    OpenAIRE

    Oliveira, Nuno Miguel Ribeiro de

    2017-01-01

    Tese de Doutoramento em Engenharia de Tecidos, Medicina Regenerativa e Células Estaminais The wettability control has been showed as an important parameter for several systems and applications on the biomedical field. Once the surface wettability has crucial influence in protein adsorption and cell adhesion. Here, the focus was on the technology development based on the advanced control of wettability in surfaces, tuning directly the surface characteristics or modifying surface...

  13. CHARACTERIZATION OF MIXED WETTABILITY AT DIFFERENT SCALES AND ITS IMPACT ON OIL RECOVERY EFFICIENCY

    Energy Technology Data Exchange (ETDEWEB)

    Mukul M. Sharma; George J. Hirasaki

    2003-09-01

    The objectives of the this research project were to: (1) Quantify the pore scale mechanisms that determine the wettability state of a reservoir; (2) Study the effect of crude oil, brine and mineral compositions in the establishment of mixed wet states; (3) Clarify the effect of mixed-wettability on oil displacement efficiency in waterfloods; and (4) Develop a new tracer technique to measure wettability, fluid distributions, residual saturations and relative permeabilities.

  14. Intellektuaalne rock

    Index Scriptorium Estoniae

    2007-01-01

    Briti laulja-helilooja ja näitleja Toyah Willcox ning Bill Rieflin ansamblist R.E.M. ja Pat Mastelotto King Krimsonist esinevad koos ansamblitega The Humans ja Tuner 25. okt. Tallinnas Rock Cafés ja 27. okt Tartu Jaani kirikus

  15. Characterization of Mixed Wettability at Different Scales and its Impact on Oil Recovery Efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Mukul M.; Hirasaki, George J.

    2002-01-28

    The objectives of this project was to: (1) quantify the pore scale mechanisms that determine the wettability state of a reservoir, (2) study the effect of crude oil, brine and mineral compositions in the establishment of mixed wet states, (3) clarify the effect of mixed - wettability on oil displacement efficiency in waterfloods, (4) develop a new tracer technique to measure wettability, fluid distributions, residual saturation's and relative permeabilities, and (5) develop methods for properly incorporating wettability in up-scaling from pore to core to reservoir scales.

  16. Igneous Rocks

    Science.gov (United States)

    Doe, Bruce R.

    “Igneous Rocks was written for undergraduate geology majors who have had a year of college-level chemistry and a course in mineralogy … and for beginning graduate students. Geologists working in industry, government, or academia should find this text useful as a guide to the technical literature up to 1981 and as an overview of topics with which they have not worked but which may have unanticipated pertinence to their own projects.” So starts the preface to this textbook.As one who works part time in research on igneous rocks, especially as they relate to mineral deposits, I have been looking for such a book with this avowed purpose in a field that has a choking richness of evolving terminology and a bewildering volume of interdisciplinary literature. In addition to the standard topics of igneous petrology, the book contains a chapter on the role of igneous activity in the genesis of mineral deposits, its value to geothermal energy, and the potential of igneous rocks as an environment for nuclear waste disposal. These topics are presented rather apologetically in the preface, but the author is to be applauded for including this chapter. The apology shows just how new these interests are to petrology. Recognition is finally coming that, for example, mineral deposits are not “sports of nature,” a view held even by many economic geologists as recently as the early 1960's; instead they are perfectly ordinary geochemical features formed by perfectly ordinary geologic processes. In fact, the mineral deposits and their attendant alteration zones probably have as much to tell us about igneous rocks as the igneous rocks have to tell us about mineral deposits.

  17. Mouillabilité et réservoirs pétroliers Wettability and Oil Reservoirs

    Directory of Open Access Journals (Sweden)

    Cuiec L.

    2006-11-01

    Full Text Available Dans la première partie de cet article, des considérations générales relatives à la mouillabilité sont exposées, en particulier sur les points suivants : - définition; - importance sur le comportement d'un système milieu poreux/fluide 1/fluide 2; - méthodes d'évaluation. Puis, différents aspects des problèmes posés par ce paramètre lors de l'étude des gisements sont abordés. Tout d'abord, le problème de l'obtention d'échantillons de roche-réservoir ayant des propriétés de surface représentatives est examiné; en effet, une telle obtention est indispensable pour réaliser des expériences de laboratoire significatives. Les causes de modification des propriétés de surface entre le réservoir et le laboratoire sont passées en revue. L'impossibilité d'empêcher à coup sûr de telles modifications justifie l'utilisation d'une procédure de restauration des propriétés originelles qui est ensuite décrite. L'existence de réservoirs non mouillables à l'eau n'est pas aussi rare que d'aucuns le pensaient il y a seulement une dizaine d'années. De nombreux travaux extraits de la littérature ou réalisés à l'Institut Français du Pétrole (IFP illustrent ce point. Enfin, l'état des connaissances concernant l'origine de la non-mouillabilité à l'eau est présenté. In the first part of this paper, general considerations about wettability are given, including:(a definition;(b importance of this parameter on the behavior of a porous-medium/fluid 1/fluid 2 system;(c methods of evaluation. Then we will examine various aspects of problems that arise for petroleum engineers because of this parameter. First of all, we will take up the problem of obtaining representative samples from the standpoint of surface properties. Obtaining such samples is indispensable for performing meaningful laboratory experiments. The causes of changes, in the surface properties of reservoir rock samples between the field and the laboratory will be

  18. Wettability of supercritical carbon dioxide/water/quartz systems: simultaneous measurement of contact angle and interfacial tension at reservoir conditions.

    Science.gov (United States)

    Saraji, Soheil; Goual, Lamia; Piri, Mohammad; Plancher, Henry

    2013-06-11

    Injection of carbon dioxide in deep saline aquifers is considered as a method of carbon sequestration. The efficiency of this process is dependent on the fluid-fluid and rock-fluid interactions inside the porous media. For instance, the final storage capacity and total amount of capillary-trapped CO2 inside an aquifer are affected by the interfacial tension between the fluids and the contact angle between the fluids and the rock mineral surface. A thorough study of these parameters and their variations with temperature and pressure will provide a better understanding of the carbon sequestration process and thus improve predictions of the sequestration efficiency. In this study, the controversial concept of wettability alteration of quartz surfaces in the presence of supercritical carbon dioxide (sc-CO2) was investigated. A novel apparatus for measuring interfacial tension and contact angle at high temperatures and pressures based on Axisymmetric Drop Shape Analysis with no-Apex (ADSA-NA) method was developed and validated with a simple system. Densities, interfacial tensions, and dynamic contact angles of CO2/water/quartz systems were determined for a wide range of pressures and temperatures relevant to geological sequestration of CO2 in the subcritical and supercritical states. Image analysis was performed with ADSA-NA method that allows the determination of both interfacial tensions and contact angles with high accuracy. The results show that supercritical CO2 alters the wettability of quartz surface toward less water-wet conditions compared to subcritical CO2. Also we observed an increase in the water advancing contact angles with increasing temperature indicating less water-wet quartz surfaces at higher temperatures.

  19. Wettability study using transmitted electrons in environmental scanning electron microscope

    Science.gov (United States)

    Barkay, Z.

    2010-05-01

    A method for quantitative wettability study at nanoscale is presented. It is based on measuring transmitted electrons through nanodroplets using wet scanning transmission electron microscope (wet-STEM) detector in environmental scanning electron microscope. The quantitative information of the nanodroplet shape and contact angle is obtained by fitting Monte Carlo simulation results for transmitted electrons through spherical cap geometry with the experimental wet-STEM results. The characterization is demonstrated for particles and for initial stages of water droplet condensation over a nonhomogeneous holey carbon grid. The method is suggested for application in thin polymer and biological films.

  20. Effects of aluminium surface morphology and chemical modification on wettability

    DEFF Research Database (Denmark)

    Rahimi, Maral; Fojan, Peter; Gurevich, Leonid

    2014-01-01

    Aluminium alloys are some of the predominant metals in industrial applications such as production of heat exchangers, heat pumps. They have high heat conductivity coupled with a low specific weight. In cold working conditions, there is a risk of frost formation on the surface of aluminium...... of a monolayer of fluorinated silane, and a combination of those. The effect of these surface modification techniques on roughness and wettability of the aluminium surfaces was elucidated by ellipsometry, contact angle measurements and atomic force microscopy. We demonstrated that by employing different types...

  1. White Rock

    Science.gov (United States)

    2002-01-01

    (Released 19 April 2002) The Science 'White Rock' is the unofficial name for this unusual landform which was first observed during the Mariner 9 mission in the early 1970's. As later analysis of additional data sets would show, White Rock is neither white nor dense rock. Its apparent brightness arises from the fact that the material surrounding it is so dark. Images from the Mars Global Surveyor MOC camera revealed dark sand dunes surrounding White Rock and on the floor of the troughs within it. Some of these dunes are just apparent in the THEMIS image. Although there was speculation that the material composing White Rock could be salts from an ancient dry lakebed, spectral data from the MGS TES instrument did not support this claim. Instead, the White Rock deposit may be the erosional remnant of a previously more continuous occurrence of air fall sediments, either volcanic ash or windblown dust. The THEMIS image offers new evidence for the idea that the original deposit covered a larger area. Approximately 10 kilometers to the southeast of the main deposit are some tiny knobs of similarly bright material preserved on the floor of a small crater. Given that the eolian erosion of the main White Rock deposit has produced isolated knobs at its edges, it is reasonable to suspect that the more distant outliers are the remnants of a once continuous deposit that stretched at least to this location. The fact that so little remains of the larger deposit suggests that the material is very easily eroded and simply blows away. The Story Fingers of hard, white rock seem to jut out like icy daggers across a moody Martian surface, but appearances can be deceiving. These bright, jagged features are neither white, nor icy, nor even hard and rocky! So what are they, and why are they so different from the surrounding terrain? Scientists know that you can't always trust what your eyes see alone. You have to use other kinds of science instruments to measure things that our eyes can

  2. On the influence of flow conditions and wettability on blood material interactions

    NARCIS (Netherlands)

    Spijker, HT; Graaff, R; Boonstra, PW; Busscher, HJ; van Oeveren, W

    2003-01-01

    In this review, we hypothesise that, next to biocompatibility, optimal blood compatibility depends on a combination of biomaterials wettability and the shear stress prevailing in the device. The wettability is discussed in seven different categories of devices, that differ substantially from each

  3. Retracted: Study of the wettability of ZnO nanofilms

    Directory of Open Access Journals (Sweden)

    Ujjwal M Joshi

    2012-04-01

    Full Text Available Al-doped and un-doped ZnO thin films deposited on quartz substrates by the nebulized spray pyrolysis method were studied to investigate the wettability of the surface. The main objective of the present study was to investigate the wettability of ZnO thin film by changing the concentration of Al doping. Microstructure and water contact angles of the films were measured by scanning electron microscopy (SEM and using a contact angle goniometer. SEM studies revealed that the grain size within the film increases with the doping concentration. The contact angles were studied to see the effect of aluminum doping on the hydrophilicity of the film. ZnO films were found to be hydrophobic in nature. A good correlation was observed between the SEM micrographs and contact angle results. The nature of the film was found to change from being hydrophobic to hydrophilic after the treatment in low-pressure DC glow discharge plasma, which, however, was reversible with the storage time.

  4. A travel in the Echeveria genus wettability's world

    Science.gov (United States)

    Godeau, Guilhem; Laugier, Jean-Pierre; Orange, François; Godeau, René-Paul; Guittard, Frédéric; Darmanin, Thierry

    2017-07-01

    Nature is a constant source of inspiration for researchers and engineers. In this work, we study the wettability of various species from the genus Echeveria. All species studied present very strong hydrophobic properties with various water adhesions. Echeveria 'Perle von Nürnberg' has properties very close to superhydrophobicity with low water adhesion (sliding angle α = 15° and contact angle hysteresis H = 9°) while Echeveria pallida and Echeveria runyonii are completely sticky (parahydrophobic) and water droplets do not move even if the surface is inclined to 90°. This work shows that most of the differences in the hydrophobic properties depend on the amount of wax crystallization. However, Echeveria pulvinata shows special wettability results. Their leaves possess long hairs. When a water droplet is placed on the surface, the water droplet is completely sticky. When the size of the droplets becomes critical, the water droplets spread across the leaf surface displaying superhydrophilic properties. More investigations reveal that the hairs are highly hydrophobic and rough due to the presence of wax crystals while the bottom of the surface is smooth and hydrophilic. Such materials are excellent candidates for water harvesting systems and oil/water separation membranes.

  5. Femtosecond laser-induced surface wettability modification of polystyrene surface

    Science.gov (United States)

    Wang, Bing; Wang, XinCai; Zheng, HongYu; Lam, YeeCheong

    2016-12-01

    In this paper, we demonstrated a simple method to create either a hydrophilic or hydrophobic surface. With femtosecond laser irradiation at different laser parameters, the water contact angle (WCA) on polystyrene's surface can be modified to either 12.7° or 156.2° from its original WCA of 88.2°. With properly spaced micro-pits created, the surface became hydrophilic probably due to the spread of the water droplets into the micro-pits. While with properly spaced micro-grooves created, the surface became rough and more hydrophobic. We investigated the effect of laser parameters on WCAs and analyzed the laser-treated surface roughness, profiles and chemical bonds by surface profilometer, scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). For the laser-treated surface with low roughness, the polar (such as C—O, C=O, and O—C=O bonds) and non-polar (such as C—C or C—H bonds) groups were found to be responsible for the wettability changes. While for a rough surface, the surface roughness or the surface topography structure played a more significant role in the changes of the surface WCA. The mechanisms involved in the laser surface wettability modification process were discussed.

  6. Effects of surface wettability on gecko adhesion underwater.

    Science.gov (United States)

    Peng, Z L; Wang, C; Chen, S H

    2014-10-01

    Recent experiments have shown that gecko adhesion underwater depends significantly on surface wettability. Theoretical models of a gecko seta adhering on different substrates are firstly established in order to disclose such an adhesion mechanism. The results show that the capillary force induced by nano-bubbles between gecko seta and the substrate is the mainly influencing factor. The capillary force exhibits an attractive feature between gecko setae and hydrophobic surfaces underwater. However, it is extremely weak or even repulsive on hydrophilic surfaces underwater. A self-similarly splitting model is further considered to simulate multiple gecko setae on substrates underwater. It is interesting to find that the total capillary force depends significantly on the number of nano-bubble bridges and wettability of substrates. The total force is attractive and increases monotonically with the increase of the splitting number on hydrophobic substrates underwater. However, it decreases drastically or even becomes repulsive on hydrophilic substrates underwater. The present result can not only give a reasonable explanation on the existing experimental observations but also be helpful for the design of novel biomimetic adhesives. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Influence of Bulk PDMS Network Properties on Water Wettability

    Science.gov (United States)

    Melillo, Matthew; Walker, Edwin; Klein, Zoe; Efimenko, Kirill; Genzer, Jan

    Poly(dimethylsiloxane) (PDMS) is one of the most common elastomers, with applications ranging from sealants and marine antifouling coatings to absorbents for water treatment. Fundamental understanding of how liquids spread on the surface of and absorb into PDMS networks is of critical importance for the design and use of another application - medical devices. We have systematically studied the effects of polymer molecular weight, loading of tetra-functional crosslinker, and end-group chemical functionality on the mechanical and surface properties of end-linked PDMS networks. Wettability was investigated through the sessile drop technique, wherein a DI water droplet was placed on the bulk network surface and droplet volume, shape, surface area, and contact angle were monitored as a function of time. Various silicone substrates ranging from incredibly soft and flexible materials (E' 50 kPa) to highly rigid networks (E' 5 MPa) were tested. The dynamic behavior of the droplet on the surfaces demonstrated equilibration times between the droplet and surface on the order of 5 minutes. Similar trends were observed for the commercial PDMS material, Sylgard-184. Our results have provided new evidence for the strong influence that substrate modulus and molecular network structure have on the wettability of PDMS elastomers. These findings will aid in the design and implementation of efficient, accurate, and safe PDMS-based medical devices and microfluidic materials that involve aqueous media.

  8. Water transport and purification in nanochannels controlled by asymmetric wettability.

    Science.gov (United States)

    Chen, Qinwen; Meng, Lingyi; Li, Qikai; Wang, Dong; Guo, Wei; Shuai, Zhigang; Jiang, Lei

    2011-08-08

    Biomimetic asymmetric nanochannels have recently attracted increasing attention from researchers, especially in the aspect of the asymmetric wettability (a hydrophilic-hydrophobic system), which can be utilized to control the wetting behavior of aqueous media and to offer a means for guiding water motion. By using molecular dynamics simulations, a design for a potentially efficient water filter is presented based on (n, n) single-walled carbon nanotubes, where n = 6, 8, 10 and 12, asymmetrically modified with hydrophilic groups (carboxyl, -COOH) at one tip and hydrophobic groups (trifluoromethyl, -CF(3) ) at the other. The reduced water density on the hydrophobic sides of the functionalized nanotubes are observed in both pure water and aqueous electrolyte solution, except for the functionalized (6, 6) tube, due to the change of dipole orientation of the single-file water wire within it. The functionalized (8, 8) tube can significantly maintain the low water density on the hydrophobic side. Both (6, 6) and (8, 8) tubes have relatively high energy barriers at their tips for ion permeation, which can be obtained by calculating the potential of mean force. Such tip functionalization of a nanotube therefore suggests the great possibilities of water transport and filtration, dominated by asymmetric wettability. The functionalized (8, 8) tube could act as a nanofluidic channel for water purification, not only for ion exclusion but also as a stable water column structure. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Wettability of AlSi5Mg on Spodumene

    Science.gov (United States)

    Fankhänel, Beate; Stelter, Michael; Voigt, Claudia; Aneziris, Christos G.

    2015-02-01

    The development of new filters for the aluminum industry requires investigations on the wettability of aluminum and its alloys on novel filter materials. The requested filter effects require not only an adequate wetting but also information about the interaction between the filter material and the metal. In the present work the wettability of an AlSi5Mg alloy on spodumene (LiAl[Si2O6]) containing substrates is investigated using the sessile drop technique. These measurements were carried out at 1223 K (950 °C) under vacuum. The spodumene-based substrates showed a completely different wetting behavior compared with an alumina substrate. The contact angel reduced more quickly and leveled out at a lower value (75 ± 2 deg) than in case of a pure alumina substrate (90 ± 1 deg). The reason for this behavior is a reaction between the LiAl(Si2O6) and the alloy droplet which supported deoxidation and formed a silica-rich reaction layer at the droplet/substrate interface.

  10. Experimental Investigation of Evaporation and Drainage in Wettable and Water-Repellent Sands

    Directory of Open Access Journals (Sweden)

    Dae Hyun Kim

    2015-05-01

    Full Text Available This study presents experimental results on evaporation and drainage in both wettable and water-repellent sands whose surface wettability was artificially modified by silanization. The 2D optical and 3D X-ray computed tomographic imaging was performed during evaporation and the water retention during cyclic drainage and infiltration was measured to assess effects of wettability and initial wetting conditions. The evaporation gradually induces its front at the early stage advance regardless of the wettability and sand types, while its rate becomes higher in water-repellent Ottawa sand than the wettable one. Jumunjin sand which has a smaller particle size and irregular particle shape than Ottawa sand exhibits a similar evaporation rate independent of wettability. Water-repellent sand can facilitate the evaporation when both wettable and water-repellent sands are naturally in contact with each other. The 3D X-ray imaging reveals that the hydraulically connected water films in wettable sands facilitate the propagation of the evaporation front into the soil such that the drying front deeply advances into the soil. For cyclic drainage-infiltration testing, the evolution of water retention is similar in both wettable and water-repellent sands when both are initially wet. However, when conditions are initially dry, water-repellent sands exhibit low residual saturation values. The experimental observations made from this study propose that the surface wettability may not be a sole factor while the degree of water-repellency, type of sands, and initial wetting condition are predominant when assessing evaporation and drainage behaviors.

  11. Water and oil wettability of anodized 6016 aluminum alloy surface

    Science.gov (United States)

    Rodrigues, S. P.; Alves, C. F. Almeida; Cavaleiro, A.; Carvalho, S.

    2017-11-01

    This paper reports on the control of wettability behaviour of a 6000 series aluminum (Al) alloy surface (Al6016-T4), which is widely used in the automotive and aerospace industries. In order to induce the surface micro-nanostructuring of the surface, a combination of prior mechanical polishing steps followed by anodization process with different conditions was used. The surface polishing with sandpaper grit size 1000 promoted aligned grooves on the surface leading to static water contact angle (WCA) of 91° and oil (α-bromonaphthalene) contact angle (OCA) of 32°, indicating a slightly hydrophobic and oleophilic character. H2SO4 and H3PO4 acid electrolytes were used to grow aluminum oxide layers (Al2O3) by anodization, working at 15 V/18° C and 100 V/0 °C, respectively, in one or two-steps configuration. Overall, the anodization results showed that the structured Al surfaces were hydrophilic and oleophilic-like with both WCA and OCA below 90°. The one-step configuration led to a dimple-shaped Al alloy surface with small diameter of around 31 nm, in case of H2SO4, and with larger diameters of around 223 nm in case of H3PO4. The larger dimples achieved with H3PO4 electrolyte allowed to reach a slight hydrophobic surface. The thicker porous Al oxide layers, produced by anodization in two-step configuration, revealed that the liquids can penetrate easily inside the non-ordered porous structures and, thus, the surface wettability tended to superhydrophilic and superoleophilic character (CA < 10°). These results indicate that the capillary-pressure balance model, described for wettability mechanisms of porous structures, was broken. Moreover, thicker oxide layers with narrow pores of about 29 nm diameter allowed to achieve WCA < OCA. This inversion in favour of the hydrophilic-oleophobic surface behaviour is of great interest either for lubrication of mechanical components or in water-oil separation process.

  12. Controllable wettability and morphology of electrodeposited surfaces on zinc substrates

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Binyan; Lu, Shixiang, E-mail: shixianglu@bit.edu.cn; Xu, Wenguo, E-mail: wenguoxu60@bit.edu.cn; Cheng, Yuanyuan

    2016-01-01

    Graphical abstract: Superhydrophobic surfaces combining hierarchical micro/nanostructures were fabricated on zinc substrates by etching, electrodeposition of ZnO coatings and annealing. Such superhydrophobic surfaces offer possibilities for chemical, biological, electronic and microfluidic applications. - Highlights: • Superhydrophobic surface was fabricated via electrodeposition of ZnO and annealing. • The ZnO hierarchical micro/nanostructures contribute to the surface superhydrophobicity. • Surface wettability and morphology can be controlled by varying process conditions. • The anti-icing properties and reversible wetting behaviors of the ZnO coatings were studied. - Abstract: Superhydrophobic surfaces combining hierarchical micro/nanostructures were fabricated on zinc substrates by etching in hydrochloric acid solution, electrodeposition of ZnO coatings and subsequent thermal annealing. The optimal coatings were electrodeposited at −1.25 V for 900 s on the etched zinc substrates and then annealed at 200 °C for 60 min, which could achieve a maximum water contact angle of 170 ± 2° and an ultra-low sliding angle of approximately 0°. By conducting SEM and water CA analysis, we found that the morphology and wettability of prepared samples were controllable by the fabrication process. Interestingly, even without any additional modification, the samples prepared under different electrodeposition conditions (including Zn(CH{sub 3}COO){sub 2} concentration from 5 mM to 40 mM and deposition time from 300 s to 1500 s) exhibited superhydrophobic character. The influences of the Zn(CH{sub 3}COO){sub 2} concentration, deposition time, annealing temperature and annealing time on the wetting behaviors were also discussed in detail. Such superhydrophobic surfaces possess long-term stability, and good corrosion resistance as well as self-cleaning ability. In addition, the anti-icing properties of the ZnO films were investigated. These surfaces could be rapidly and

  13. Substrate wettability requirement for the direct transfer of graphene

    Science.gov (United States)

    Du, F.; Duan, H. L.; Xiong, C. Y.; Wang, J. X.

    2015-10-01

    The direct transfer method, wherein graphene is transferred from its growth metal to a soft substrate, is widely used to fabricate various devices, and the interfacial bonding condition between the substrate and the graphene is vital for transfer success. In this letter, we present a theoretical model to derive the wettability requirements of the soft substrate to sustain the direct transfer of graphene, and verify the theoretical analysis with experiments. We find that the surface energy components of the substrate have a crucial effect upon the graphene transfer, and that substrates possessing a strong polar surface energy are not suitable for transfer. The theoretical model predicts the critical water contact angle of the soft substrate for graphene transfer to be about 50°, and the experiments measure it to be about 60°. These results provide guidelines for choosing proper substrates to transfer graphene during the fabrication of graphene-based flexible devices.

  14. Using Statistical Analysis Software to Advance Nitro Plasticizer Wettability

    Energy Technology Data Exchange (ETDEWEB)

    Shear, Trevor Allan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-08-29

    Statistical analysis in science is an extremely powerful tool that is often underutilized. Additionally, it is frequently the case that data is misinterpreted or not used to its fullest extent. Utilizing the advanced software JMP®, many aspects of experimental design and data analysis can be evaluated and improved. This overview will detail the features of JMP® and how they were used to advance a project, resulting in time and cost savings, as well as the collection of scientifically sound data. The project analyzed in this report addresses the inability of a nitro plasticizer to coat a gold coated quartz crystal sensor used in a quartz crystal microbalance. Through the use of the JMP® software, the wettability of the nitro plasticizer was increased by over 200% using an atmospheric plasma pen, ensuring good sample preparation and reliable results.

  15. Effect of wettability alteration on long-term behavior of fluids in subsurface

    Energy Technology Data Exchange (ETDEWEB)

    Bandara, Uditha C.; Palmer, Bruce J.; Tartakovsky, Alexandre M.

    2016-01-13

    Wettability is an important factor affecting fluid behavior in the subsurface, including oil, gas, and supercritical CO$_2$ in deep geological reservoirs. For example, CO$_2$ is generally assumed to behave as a non-wetting fluid, which favors safe storage. However, because of chemical heterogeneity of the reservoirs, mixed wettability conditions can exist. Furthermore, recent experiments suggest that with time, the wettability of super-critical CO$_2$ may change from non-wetting to partially-wetting due to changes in electrostatic interactions. These changes are caused by chemical reactions between dissolved CO$_2$ and its environment. To date, the effect of wettability alteration and mixed wettability on the long term fate of injected CO$_2$ has not well been studied. Here, we use the multiphase Pairwise Force Smoothed Particle Hydrodynamics (PF-SPH) Model to study complex pore-scale processes involved in geological CO$_2$ sequestration, including the effect of spatial and temporal wettability variations on long-term distribution of CO$_2$ in porous media. Results reveal that in the absence of dissolution of supercritical CO$_2$ and precipitation of carbonate minerals (mineral trapping), the amount of trapped supercritical CO$_2$ significantly decreases as the wettability of the porous media changes from brine-wet to partial-wet or CO$_2$-wet.

  16. Surface wettability enhancement of silicone hydrogel lenses by processing with polar plastic molds.

    Science.gov (United States)

    Lai, Y C; Friends, G D

    1997-06-05

    In the quest for hydrogel contact lenses with improved extended wear capability, the use of siloxane moieties in the lens materials was investigated. However, the introduction of hydrophobic siloxane groups gave rise to wettability and lipidlike deposit problems. It was found that when polysiloxane-based compositions for hydrogels were processed with polar plastic molds, such as those fabricated from an acrylonitrile-based polymer, the hydrogel lenses fabricated were wettable, with minimized lipidlike deposits. These findings were supported by the wettability of silicone hydrogel films, silicon, and nitrogen element contents near lens surfaces, as well as the results from clinical assessment of silicone hydrogel lenses.

  17. Surface wettability effects on critical heat flux of boiling heat transfer using nanoparticle coatings

    KAUST Repository

    Hsu, Chin-Chi

    2012-06-01

    This study investigates the effects of surface wettability on pool boiling heat transfer. Nano-silica particle coatings were used to vary the wettability of the copper surface from superhydrophilic to superhydrophobic by modifying surface topography and chemistry. Experimental results show that critical heat flux (CHF) values are higher in the hydrophilic region. Conversely, CHF values are lower in the hydrophobic region. The experimental CHF data of the modified surface do not fit the classical models. Therefore, this study proposes a simple model to build the nexus between the surface wettability and the growth of bubbles on the heating surface. © 2012 Elsevier Ltd. All rights reserved.

  18. Overview of the potential and identified petroleum source rocks of the Appalachian basin, eastern United States: Chapter G.13 in Coal and petroleum resources in the Appalachian basin: distribution, geologic framework, and geochemical character

    Science.gov (United States)

    Coleman, James L.; Ryder, Robert T.; Milici, Robert C.; Brown, Stephen; Ruppert, Leslie F.; Ryder, Robert T.

    2014-01-01

    The Appalachian basin is the oldest and longest producing commercially viable petroleum-producing basin in the United States. Source rocks for reservoirs within the basin are located throughout the entire stratigraphic succession and extend geographically over much of the foreland basin and fold-and-thrust belt that make up the Appalachian basin. Major source rock intervals occur in Ordovician, Devonian, and Pennsylvanian strata with minor source rock intervals present in Cambrian, Silurian, and Mississippian strata.

  19. CERN Rocks

    CERN Multimedia

    2004-01-01

    The 15th CERN Hardronic Festival took place on 17 July on the terrace of Rest 3 (Prévessin). Over 1000 people, from CERN and other International Organizations, came to enjoy the warm summer night, and to watch the best of the World's High Energy music. Jazz, rock, pop, country, metal, blues, funk and punk blasted out from 9 bands from the CERN Musiclub and Jazz club, alternating on two stages in a non-stop show.  The night reached its hottest point when The Canettes Blues Band got everybody dancing to sixties R&B tunes (pictured). Meanwhile, the bars and food vans were working at full capacity, under the expert management of the CERN Softball club, who were at the same time running a Softball tournament in the adjacent "Higgs Field". The Hardronic Festival is the main yearly CERN music event, and it is organized with the support of the Staff Association and the CERN Administration.

  20. Fundamentals of reservoir surface energy as related to surface properties, wettability, capillary action, and oil recovery from fractured reservoirs by spontaneous imbibition

    Energy Technology Data Exchange (ETDEWEB)

    Norman R. Morrow; Herbert Fischer; Yu Li; Geoffrey Mason; Douglas Ruth; Siddhartha Seth; Jason Zhengxin Tong; Peigui Yin; Shaochang Wo

    2006-02-01

    -wet rocks. Imbibition measurements will include novel sensitive pressure measurements designed to elucidate the basic mechanisms that determine induction time and drive the very slow rate of spontaneous imbibition commonly observed for mixed-wet rocks. In further demonstration of concepts, three approaches to improved oil recovery from fractured reservoirs will be tested; use of surfactants to promote imbibition in oil wet rocks by wettability alteration: manipulation of injection brine composition: reduction of the capillary back pressure which opposes production of oil at the fracture face.

  1. Fundamentals of reservoir surface energy as related to surface properties, wettability, capillary action, and oil recovery from fractured reservoirs by spontaneous imbibition

    Energy Technology Data Exchange (ETDEWEB)

    Norman R. Morrow; Herbert Fischer; Yu Li; Geoffrey Mason; Douglas Ruth; Siddhartha Seth; Jason Zhengxin Tong; Peigui Yin; Shaochang Wo

    2006-06-08

    -wet rocks. Imbibition measurements will include novel sensitive pressure measurements designed to elucidate the basic mechanisms that determine induction time and drive the very slow rate of spontaneous imbibition commonly observed for mixed-wet rocks. In further demonstration of concepts, three approaches to improved oil recovery from fractured reservoirs will be tested; use of surfactants to promote imbibition in oil wet rocks by wettability alteration: manipulation of injection brine composition: reduction of the capillary back pressure which opposes production of oil at the fracture face.

  2. Fundamentals of Reservoir Surface Energy as Related to Surface Properties, Wettability, Capillary Action, and Oil Recovery from Fractured Reservoirs by Spontaneous Imbibition

    Energy Technology Data Exchange (ETDEWEB)

    Norman Morrow; Herbert Fischer; Yu Li; Geoffrey Mason; Douglas Ruth; Siddhartha Seth; Zhengxin Tong; Evren Unsal; Siluni Wickramathilaka; Shaochang Wo; Peigui Yin

    2008-06-30

    -wet rocks. Imbibition measurements will include novel sensitive pressure measurements designed to elucidate the basic mechanisms that determine induction time and drive the very slow rate of spontaneous imbibition commonly observed for mixed-wet rocks. In further demonstration of concepts, three approaches to improved oil recovery from fractured reservoirs will be tested; use of surfactants to promote imbibition in oil wet rocks by wettability alteration: manipulation of injection brine composition: reduction of the capillary back pressure which opposes production of oil at the fracture face.

  3. FUNDAMENTALS OF RESERVOIR SURFACE ENERGY AS RELATED TO SURFACE PROPERTIES, WETTABILITY, CAPILLARY ACTION, AND OIL RECOVERY FROM FRACTURED RESERVOIRS BY SPONTANEOUS IMBIBITION

    Energy Technology Data Exchange (ETDEWEB)

    Norman R. Morrow; Herbert Fischer; Yu Li; Geoffrey Mason; Douglas Ruth; Siddhartha Seth; Peigui Yin; Shaochang Wo

    2004-10-01

    -wet rocks. Imbibition measurements will include novel sensitive pressure measurements designed to elucidate the basic mechanisms that determine induction time and drive the very slow rate of spontaneous imbibition commonly observed for mixed-wet rocks. In further demonstration of concepts, three approaches to improved oil recovery from fractured reservoirs will be tested; use of surfactants to promote imbibition in oil wet rocks by wettability alteration: manipulation of injection brine composition: reduction of the capillary back pressure which opposes production of oil at the fracture face.

  4. Wettability conundrum: Discrepancies of soft contact lens performance in vitro and in vivo

    Science.gov (United States)

    Svitova, T. F.; Lin, M. C.

    2011-08-01

    The recognition and appreciation of soft contact lenses as simple, efficient and aesthetically gratifying vision-correction devices is ever growing, especially among younger population. Stable thin tear film uniformly spread over corrective lens surface is essential for acute vision, and also for comfortable and safe contact lens wear. The significant efforts have been invested by the contact lens industry to develop soft lens surface that is completely wet by tear aqueous in the ocular environment. Number of the publications dedicated to the wettability properties of the soft hydrogel lenses is on the steady rise. However, the clinical results show that no unambiguous correlation emerges when lens surface wettability in vitro is judged against tear film stability evaluated in vivo. This paper assesses and compares the modern techniques used for evaluation of soft contact lens surface wettability and reports some findings regarding relations between lens surface wettability in vitro and in vivo.

  5. Effects of the natural microstructures on the wettability of leaf surfaces

    Directory of Open Access Journals (Sweden)

    L.F. Wang

    2016-06-01

    Full Text Available The effects of natural microstructures on the wettability are investigated based on the systematic analysis on the contact angles and morphology of the leaf surfaces of four kinds of plants, Photinia serrulata, Ginkgo, Aloe vera and Hypericum monogynum. P. serrulata possesses the most wettable leaf surface due to the small corrugation and raised boundary of the microstructures, while H. monogynum leaf shows the largest contact angle as it exhibits corrugated microstructures with smaller pitch value and larger height compared with that of Aloe vera. The long-shaped and well aligned microstructures, which are beneficial for the diffusion of water, make the Ginkgo leaf surface to be hydrophilic. The study elaborates the effects of microstructures on the surface wettability, which shed light on the design of surfaces for different wettable needs.

  6. Influence of Aggregate Wettability with Different Lithology Aggregates on Concrete Drying Shrinkage

    OpenAIRE

    Yuanchen Guo; Jueshi Qian; Xue Wang; Zhengyi Yan; Huadong Zhong

    2015-01-01

    The correlation of the wettability of different lithology aggregates and the drying shrinkage of concrete materials is studied, and some influential factors such as wettability and wetting angle are analyzed. A mercury porosimeter is used to measure the porosities of different lithology aggregates accurately, and the pore size ranges that significantly affect the drying shrinkage of different lithology aggregate concretes are confirmed. The pore distribution curve of the different coarse aggr...

  7. Surface energy and wettability of van der Waals structures

    Science.gov (United States)

    Annamalai, Meenakshi; Gopinadhan, Kalon; Han, Sang A.; Saha, Surajit; Park, Hye Jeong; Cho, Eun Bi; Kumar, Brijesh; Patra, Abhijeet; Kim, Sang-Woo; Venkatesan, T.

    2016-03-01

    The wetting behaviour of surfaces is believed to be affected by van der Waals (vdW) forces; however, there is no clear demonstration of this. With the isolation of two-dimensional vdW layered materials it is possible to test this hypothesis. In this paper, we report the wetting behaviour of vdW heterostructures which include chemical vapor deposition (CVD) grown graphene, molybdenum disulfide (MoS2) and tungsten disulfide (WS2) on few layers of hexagon boron nitride (h-BN) and SiO2/Si. Our study clearly shows that while this class of two-dimensional materials are not completely wetting transparent, there seems to be a significant amount of influence on their wetting properties by the underlying substrate due to dominant vdW forces. Contact angle measurements indicate that graphene and graphene-like layered transitional metal dichalcogenides invariably have intrinsically dispersive surfaces with a dominating London-vdW force-mediated wettability.The wetting behaviour of surfaces is believed to be affected by van der Waals (vdW) forces; however, there is no clear demonstration of this. With the isolation of two-dimensional vdW layered materials it is possible to test this hypothesis. In this paper, we report the wetting behaviour of vdW heterostructures which include chemical vapor deposition (CVD) grown graphene, molybdenum disulfide (MoS2) and tungsten disulfide (WS2) on few layers of hexagon boron nitride (h-BN) and SiO2/Si. Our study clearly shows that while this class of two-dimensional materials are not completely wetting transparent, there seems to be a significant amount of influence on their wetting properties by the underlying substrate due to dominant vdW forces. Contact angle measurements indicate that graphene and graphene-like layered transitional metal dichalcogenides invariably have intrinsically dispersive surfaces with a dominating London-vdW force-mediated wettability. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr06705

  8. Wettability measurement apparatus for porous material using the modified Washburn method

    Science.gov (United States)

    Thakker, Manish; Karde, Vikram; Shah, Dinesh O.; Shukla, Premal; Ghoroi, Chinmay

    2013-12-01

    In this work a cost-effective instrument for measuring the wettability of powder materials was designed and developed, which works on the modified Washburn method. The instrument measures the mass gain against time due to penetration of the liquid into the powder materials using a microbalance and LabVIEW-based data acquisition system. The wettability characteristic of different powders was determined from the contact angle using the modified Washburn equation. To demonstrate the performance of the developed instrument, the wettability of as-received corn starch and nano-coated corn starch powders was estimated with water as a test liquid. The corn starch powders coated with hydrophilic grade (Aerosil 200P) and hydrophobic grade (Aerosil R972) nanoparticles at different coating levels showed expected changes in their contact angle. Some of the results were also verified against the available standard instrument for wettability measurement and found to be consistent. The present configuration of the instrument costs about 500 US which is 15 to 20 times less than the available advanced models. The developed instrument is thus a cost-effective solution for wettability measurement which can be used for materials in food processing, pharmaceuticals, horticulture, textile manufacturing, civil engineering etc. The developed instrument is expected to help many small scale industries or research labs who cannot afford an expensive instrument for wettability studies.

  9. A review on the wettability of dental implant surfaces I: theoretical and experimental aspects.

    Science.gov (United States)

    Rupp, Frank; Gittens, Rolando A; Scheideler, Lutz; Marmur, Abraham; Boyan, Barbara D; Schwartz, Zvi; Geis-Gerstorfer, Jürgen

    2014-07-01

    The surface wettability of biomaterials determines the biological cascade of events at the biomaterial/host interface. Wettability is modulated by surface characteristics, such as surface chemistry and surface topography. However, the design of current implant surfaces focuses mainly on specific micro- and nanotopographical features, and is still far from predicting the concomitant wetting behavior. There is an increasing interest in understanding the wetting mechanisms of implant surfaces and the role of wettability in the biological response at the implant/bone or implant/soft tissue interface. Fundamental knowledge related to the influence of surface roughness (i.e. a quantification of surface topography) on titanium and titanium alloy surface wettability, and the different associated wetting regimes, can improve our understanding of the role of wettability of rough implant surfaces on the biological outcome. Such an approach has been applied to biomaterial surfaces only in a limited way. Focusing on titanium dental and orthopaedic implants, the present study reviews the current knowledge on the wettability of biomaterial surfaces, encompassing basic and applied aspects that include measurement techniques, thermodynamic aspects of wetting and models predicting topographical and roughness effects on the wetting behavior. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  10. Laser processing of metallic biomaterials: An approach for surface patterning and wettability control

    Science.gov (United States)

    Razi, Sepehr; Mollabashi, Mahmoud; Madanipour, Khosro

    2015-12-01

    Q -switched Nd:YAG laser is used to manipulate the surface morphology and wettability characteristic of 316L stainless steel (SS) and titanium biomaterials. Water and glycerol are selected as wettability testing liquids and the sessile drop method is used for the contact angle measurements. Results indicate that on both of the metals, wettability toward water improves significantly after the laser treatment. Different analyses including the study of the surface morphology, free energy and oxidation are assessed in correlation with wettability. Beside the important role of the laser-induced surface patterns, the increase in the surface roughness, oxygen content and the polar component of the surface energy, are detected as the most important physical and chemical phenomena controlling the improvement in the wettability. However, all the processed hydrophilic surfaces that are exposed to air become hydrophobic over time. The time dependency of the surface wettability is related to the chemical activities on the treated surfaces and the reduction of oxygen/carbon (O/C) ratio on them. The behavior is further studied with investigating the effect of the keeping environment and changes of the components of the surface tension. Results show that the pulsed laser treatment is a versatile approach to create either hydrophobic or super hydrophilic surfaces for industrial and medical applications.

  11. Wettability controls slow immiscible displacement through local interfacial instabilities

    Science.gov (United States)

    Jung, Michael; Brinkmann, Martin; Seemann, Ralf; Hiller, Thomas; Sanchez de La Lama, Marta; Herminghaus, Stephan

    2016-11-01

    Immiscible fluid displacement with average front velocities in the capillary-dominated regime is studied in a transparent Hele-Shaw cell with cylindrical posts. Employing various combinations of fluids and wall materials allows us to cover a range of advancing contact angles 46∘≤θa≤180∘ of the invading fluid in our experiments. In parallel, we study the displacement process in particle-based simulations that account for wall wettability. Considering the same arrangement of posts in experiments and simulation, we find a consistent crossover between stable interfacial displacement at θa≲80∘ and capillary fingering at high contact angles θa≳120∘ . The position of the crossover is quantified through the evolution of the interface length and the final saturation of the displaced fluid. A statistical analysis of the local displacement processes demonstrates that the shape evolution of the fluid front is governed by local instabilities as proposed by Cieplak and Robbins for a quasistatic interfacial displacement [Cieplak and Robbins, Phys. Rev. Lett. 60, 2042 (1988), 10.1103/PhysRevLett.60.2042]. The regime of stable front advances coincides with a corresponding region of contact angles where cooperative interfacial instabilities prevail. Capillary fingering, however, is observed only for large θa, where noncooperative instabilities dominate the invasion process.

  12. Wettability of naturally aged silicone and EPDM composite insulators

    Energy Technology Data Exchange (ETDEWEB)

    Gubanski, S.M. (Royal Inst. of Tech., Stockholm (Sweden)); Vlastos, A.E. (Chalmers Univ. of Tech., Goeteborg (Sweden))

    1990-07-01

    This paper reports the wettability of aged surfaces and of the bulk of naturally aged silicone and EPDM insulator housings and of silicone elastomer insulator coatings studied. The samples were taken either directly from the insulators or treated by exposing them to corona discharges and/or to saline pollution. The results show that the contact angles of the silicone rubber insulator surfaces are larger than the contact angles of the RTV silicone rubber coating and of the EPDM rubber insulator surfaces, especially when the surfaces are aged. When the insulators were exposed to corona discharges, the contact angles of the silicone rubber insulators are reduced but after the exposure they recover with time. The contact angles of the EPDM rubber insulators, however, after the exposure, continue to reduce. When exposed to artificial saline pollution, the silicone rubber insulators show a limited recovery of their contact angles with time, while, when exposed to corona discharge, they show a recovery of the contact angle after the exposure. The time for recovery is dependent on the exposure time to the corona discharges.

  13. The wettability of PTFE and glass surfaces by nanofluids.

    Science.gov (United States)

    Chaudhuri, Rajib Ghosh; Paria, Santanu

    2014-11-15

    Wetting of solid surfaces by surfactant solutions is well focused in the literature compared that of nanofluids. Similar to the surfactant solutions nanofluids are also able to reduce the surface tension as well as influence on contact angle at the solid, liquid and gas interface. The surface tension and wettability of two different nanofluids containing hydrophilic (TiO2) and hydrophobic (S) particles have been experimentally studied here. The surface tension reduction of nanofluids strongly depends on material property, particle size and as well as concentration. These parameters also influence the change in contact angle on both hydrophilic (glass) and hydrophobic (PTFE) surfaces. Three important factors such as surface tension, surface hydrophobicity after deposition of particles on a solid surface, and the disjoining pressure influence the final contact angle of nanofluids on a solid surface. Sulfur nanofluids show maximum enhancement in contact angle (30.6°) on the glass surface; on the other hand TiO2 nanofluids show maximum reductions in surface tension (25.4 mN/m) and contact angle on the PTFE surface (17.7°) with respect to pure water. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Surface wettability plays a significant role in gecko adhesion underwater.

    Science.gov (United States)

    Stark, Alyssa Y; Badge, Ila; Wucinich, Nicholas A; Sullivan, Timothy W; Niewiarowski, Peter H; Dhinojwala, Ali

    2013-04-16

    Although we now have thousands of studies focused on the nano-, micro-, and whole-animal mechanics of gecko adhesion on clean, dry substrates, we know relatively little about the effects of water on gecko adhesion. For many gecko species, however, rainfall frequently wets the natural surfaces they navigate. In an effort to begin closing this gap, we tested the adhesion of geckos on submerged substrates that vary in their wettability. When tested on a wet hydrophilic surface, geckos produced a significantly lower shear adhesive force (5.4 ± 1.33 N) compared with a dry hydrophilic surface (17.1 ± 3.93 N). In tests on an intermediate wetting surface and a hydrophobic surface, we found no difference in shear adhesion between dry and wet contact. Finally, in tests on polytetrafluoroethylene (PTFE), we found that geckos clung significantly better to wet PTFE (8.0 ± 1.09 N) than dry PTFE (1.6 ± 0.66 N). To help explain our results, we developed models based on thermodynamic theory of adhesion for contacting surfaces in different media and found that we can predict the ratio of shear adhesion in water to that in air. Our findings provide insight into how geckos may function in wet environments and also have significant implications for the development of a synthetic gecko mimic that retains adhesion in water.

  15. Atmospheric Water Harvesting: Role of Surface Wettability and Edge Effect

    KAUST Repository

    Jin, Yong

    2017-06-23

    Atmospheric water is emerging as an important potable water source. The present work experimentally and theoretically investigates water condensation and collection on flat surfaces with contrasting contact angles and contact angle hysteresis (CAH) to elucidate their roles on water mass collection efficiency. The experimental results indicate that a hydrophilic surface promotes nucleation and individual droplets growth, and a surface with a low CAH tends to let a smaller droplet to slide down, but the overall water mass collection efficiency is independent of both surface contact angle and CAH. The experimental results agree well with our theoretical calculations. During water condensation, a balance has to be struck between single droplet growth and droplet density on a surface so as to maintain a constant water droplet surface coverage ratio, which renders the role of both surface wettability and hysteresis insignificant to the ultimate water mass collection. Moreover, water droplets on the edges of a surface grow much faster than those on the non-edge areas and thus dominate the contribution to the water mass collection by the entire surface, directly pointing out the very important role of edge effect on water condensation and collection.

  16. Rollerjaw Rock Crusher

    Science.gov (United States)

    Peters, Gregory; Brown, Kyle; Fuerstenau, Stephen

    2009-01-01

    The rollerjaw rock crusher melds the concepts of jaw crushing and roll crushing long employed in the mining and rock-crushing industries. Rollerjaw rock crushers have been proposed for inclusion in geological exploration missions on Mars, where they would be used to pulverize rock samples into powders in the tens of micrometer particle size range required for analysis by scientific instruments.

  17. Fluid-Rock Characterization and Interactions in NMR Well Logging

    Energy Technology Data Exchange (ETDEWEB)

    George J. Hirasaki; Kishore K. Mohanty

    2005-09-05

    The objective of this report is to characterize the fluid properties and fluid-rock interactions that are needed for formation evaluation by NMR well logging. The advances made in the understanding of NMR fluid properties are summarized in a chapter written for an AAPG book on NMR well logging. This includes live oils, viscous oils, natural gas mixtures, and the relation between relaxation time and diffusivity. Oil based drilling fluids can have an adverse effect on NMR well logging if it alters the wettability of the formation. The effect of various surfactants on wettability and surface relaxivity are evaluated for silica sand. The relation between the relaxation time and diffusivity distinguishes the response of brine, oil, and gas in a NMR well log. A new NMR pulse sequence in the presence of a field gradient and a new inversion technique enables the T{sub 2} and diffusivity distributions to be displayed as a two-dimensional map. The objectives of pore morphology and rock characterization are to identify vug connectivity by using X-ray CT scan, and to improve NMR permeability correlation. Improved estimation of permeability from NMR response is possible by using estimated tortuosity as a parameter to interpolate between two existing permeability models.

  18. Exploring the Role of Habitat on the Wettability of Cicada Wings.

    Science.gov (United States)

    Oh, Junho; Dana, Catherine E; Hong, Sungmin; Román, Jessica K; Jo, Kyoo Dong; Hong, Je Won; Nguyen, Jonah; Cropek, Donald M; Alleyne, Marianne; Miljkovic, Nenad

    2017-08-16

    Evolutionary pressure has pushed many extant species to develop micro/nanostructures that can significantly affect wettability and enable functionalities such as droplet jumping, self-cleaning, antifogging, antimicrobial, and antireflectivity. In particular, significant effort is underway to understand the insect wing surface structure to establish rational design tools for the development of novel engineered materials. Most studies, however, have focused on superhydrophobic wings obtained from a single insect species, in particular, the Psaltoda claripennis cicada. Here, we investigate the relationship between the spatially dependent wing wettability, topology, and droplet jumping behavior of multiple cicada species and their habitat, lifecycle, and interspecies relatedness. We focus on cicada wings of four different species: Neotibicen pruinosus, N. tibicen, Megatibicen dorsatus, and Magicicada septendecim and take a comparative approach. Using spatially resolved microgoniometry, scanning electron microscopy, atomic force microscopy, and high speed optical microscopy, we show that within cicada species, the wettability of wings is spatially homogeneous across wing cells. All four species were shown to have truncated conical pillars with widely varying length scales ranging from 50 to 400 nm in height. Comparison of the wettability revealed three cicada species with wings that are superhydrophobic (>150°) with low contact angle hysteresis (wing wettability yielded little connection as wetter, swampy environments do not necessarily equate to higher measured wing hydrophobicity. The results, however, do point to species relatedness and reproductive strategy as a closer proxy for predicting wettability and surface structure and resultant enhanced wing surface functionality. This work not only elucidates the differences between inter- and intraspecies cicada wing topology, wettability, and water shedding behavior but also enables the development of rational design

  19. A general and facile chemical avenue for the controlled and extreme regulation of water wettability in air and oil wettability under water.

    Science.gov (United States)

    Parbat, Dibyangana; Gaffar, Sana; Rather, Adil Majeed; Gupta, Aditi; Manna, Uttam

    2017-09-01

    The controlled modulation of both oil (under water) and water (in air) wettability is an emerging approach to develop several functional materials for various prospective applications including oil/water separation, anti-corrosive coatings, underwater robotics, protein crystallization, drug delivery, open microfluidics, water harvesting etc. Here, we report a 'reactive' and covalently cross-linked coating through a facile and robust Michael addition reaction, which is suitable for the controlled and extreme regulation of both water and oil wettability in air and under water respectively. Along with extremes (super-philicity and super-phobicity) of water (in air) and oil (under water) wettability, this single multilayer construction was also able to display special liquid wettability (i.e.; extremely liquid repellent-but with controlled adhesive properties) both in air and under water, after strategic post chemical modifications, again through 1,4-conjugate addition reaction. The super-wetting properties in the materials were able to withstand various physical and chemical insults including adhesive tape test, sand drop test, and exposure to extremes of pH, salt, and surfactant contaminated aqueous media. Moreover, this approach also allowed the decoration of various flexible and rigid substrates (i.e.; wood, Al-foil, synthetic fabric etc.) with various bio-inspired wettability properties including (1) non-adhesive superhydrophobicity (lotus leaf), (2) adhesive superhydrophobicity (rose petal), (3) underwater superoleophobicity (fish scale) etc. This single polymeric coating-which is capable of displaying several bio-inspired interfaces both in air and under water, even after harsh physical/chemical insults-would be useful in various prospective and relevant applications for practical scenarios.

  20. Base Layer Influence on Protonated Aminosilane Gradient Wettability.

    Science.gov (United States)

    Ashraf, Kayesh M; Wang, Chenyu; Nair, Sithara S; Wynne, Kenneth J; Higgins, Daniel A; Collinson, Maryanne M

    2017-05-02

    Protonated amine gradients have been prepared on silicon wafers via programmed controlled rate infusion (CRI) with varying degrees of hydrophobicity and characterized by X-ray photoelectron spectroscopy (XPS) and static and Wilhelmy plate dynamic contact angle measurements. Initially, base layers were spin coated from sols containing tetramethoxysilane (TMOS) and either phenyltrimethoxysilane (PTMOS), dimethyldimethoxysilane (DMDMOS), or octyltrimethoxysilane (OTMOS, C8). Amine gradients were then prepared from 3-aminopropyltriethoxysilane (APTEOS) via CRI. Gradients were exposed to concentrated HCl vapor for amine protonation. XPS showed that NH2 functional groups were distributed in a gradient fashion as a result of CRI controlling the time of exposure to APTEOS. Interestingly, the overall extent of N modification depended on the type of base layer used for gradient formation. The C8-derived base layer had about half the amount of nitrogen on the surface as compared to those prepared from TMOS, which was attributed to a reduction in the number and accessibility of surface silanol groups. The wettability and contact angle (CA) hysteresis were also dependent on the base layer and varied along the length of the gradient. The greatest CA change across the length of the gradient was observed on the gradient formed on the C8-derived base layer. Likewise, the CA hysteresis was approximately 2 times larger on the C8-modified surfaces, indicative of greater chemical inhomogeneity. In contrast to uniformly modified substrates, Wilhelmy plate CA analysis that involves the immersion of samples gave a unique S-shaped CA distance curve for the gradients. The three curve segments correspond to hydrophilic, hydrophobic, and a middle connecting region. Importantly, these curves give precise CAs along the gradient that reflect the surface chemistry and coverage defined by programmed CRI processing.

  1. Influence of Aggregate Wettability with Different Lithology Aggregates on Concrete Drying Shrinkage

    Directory of Open Access Journals (Sweden)

    Yuanchen Guo

    2015-01-01

    Full Text Available The correlation of the wettability of different lithology aggregates and the drying shrinkage of concrete materials is studied, and some influential factors such as wettability and wetting angle are analyzed. A mercury porosimeter is used to measure the porosities of different lithology aggregates accurately, and the pore size ranges that significantly affect the drying shrinkage of different lithology aggregate concretes are confirmed. The pore distribution curve of the different coarse aggregates is also measured through a statistical method, and the contact angle of different coarse aggregates and concrete is calculated according to the linear fitting relationship. Research shows that concrete strength is determined by aggregate strength. Aggregate wettability is not directly correlated with concrete strength, but wettability significantly affects concrete drying shrinkage. In all types’ pores, the greatest impacts on wettability are capillary pores and gel pores, especially for the pores of the size locating 2.5–50 nm and 50–100 nm two ranges.

  2. Effect of wettability of a porous stainless steel on thermally induced liquid–vapor interface behavior

    Science.gov (United States)

    Oka, C.; Odagiri, K.; Nagano, H.

    2017-12-01

    Control of thermally induced liquid–vapor interface behavior at the contact surface of porous media is crucial for development of two-phase heat transfer devices such as loop heat pipes. The behavior experiences three modes with increase of heat flux, and the middle mode possesses the highest heat transfer performance. In this paper, the effect of improving wettability of the porous media is demonstrated experimentally and numerically for the first time, in particular with regard to the effect on a domain of the middle mode. Ethanol wettability of a porous stainless steel was improved via a facile method, which was a simple acid treatment. As a result, the domain of the middle mode was extended as a consequence of the wettability improvement. The mode transfers from the middle to the last one when the pressure drop in the liquid supply exceeds the capillary pressure of liquid bridges formed between the heating plate and the porous medium. Hence, the extension of the domain suggested that the capillary pressure was increased by the wettability improvement. This was verified via numerical calculation. The calculated capillary pressure was increased by 7% after improving wettability, which resulted in the extension of the domain of the middle mode.

  3. Time dependent wettability of graphite upon ambient exposure: The role of water adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Amadei, Carlo A.; Lai, Chia-Yun; Heskes, Daan; Chiesa, Matteo, E-mail: mchiesa@masdar.ac.ae [Laboratory for Energy and NanoScience (LENS), Institute Center for Future Energy (iFES), Masdar Institute of Science and Technology, Abu Dhabi (United Arab Emirates)

    2014-08-28

    We report the temporal evolution of the wettability of highly ordered pyrolytic graphite (HOPG) exposed to environmental conditions. Macroscopic wettability is investigated by static and dynamic contact angles (SCA and DCA) obtaining values comparable to the ones presented in the literature. SCA increases from ∼68° to ∼90° during the first hour of exposure after cleaving, whereas DCA is characterized by longer-scale (24 h) time evolution. We interpret these results in light of Fourier transform infrared spectroscopy, which indicates that the evolution of the HOPG wettability is due to adsorption of molecules from the surrounding atmosphere. This hypothesis is further confirmed by nanoscopic observations obtained by atomic force microscope (AFM)-based force spectroscopy, which monitor the evolution of surface properties with a spatial resolution superior to macroscopic experiments. Moreover, we observe that the results of macro- and nanoscale measurements evolve in similar fashion with time and we propose a quantitative correlation between SCA and AFM measurements. Our results suggest that the cause of the transition in the wettability of HOPG is due to the adsorption of hydrocarbon contaminations and water molecules from the environment. This is corroborated by annealing the HOPG is vacuum conditions at 150°, allowing the desorption of molecules on the surface, and thus re-establishing the initial macro and nano surface properties. Our findings can be used in the interpretation of the wettability of more complicated systems derived from HOPG (i.e., graphene)

  4. Rocks Can Wow? Yes, Rocks Can Wow!

    Science.gov (United States)

    Hardman, Sally; Luke, Sue

    2016-01-01

    Rocks and fossils appear in the National Curriculum of England science programmes of study for children in year 3 (ages 7-8). A frequently asked question is "How do you make the classification of rocks engaging?" In response to this request from a school, a set of interactive activities was designed and organised by tutors and students…

  5. Robotic Rock Classification

    Science.gov (United States)

    Hebert, Martial

    1999-01-01

    This report describes a three-month research program undertook jointly by the Robotics Institute at Carnegie Mellon University and Ames Research Center as part of the Ames' Joint Research Initiative (JRI.) The work was conducted at the Ames Research Center by Mr. Liam Pedersen, a graduate student in the CMU Ph.D. program in Robotics under the supervision Dr. Ted Roush at the Space Science Division of the Ames Research Center from May 15 1999 to August 15, 1999. Dr. Martial Hebert is Mr. Pedersen's research adviser at CMU and is Principal Investigator of this Grant. The goal of this project is to investigate and implement methods suitable for a robotic rover to autonomously identify rocks and minerals in its vicinity, and to statistically characterize the local geological environment. Although primary sensors for these tasks are a reflection spectrometer and color camera, the goal is to create a framework under which data from multiple sensors, and multiple readings on the same object, can be combined in a principled manner. Furthermore, it is envisioned that knowledge of the local area, either a priori or gathered by the robot, will be used to improve classification accuracy. The key results obtained during this project are: The continuation of the development of a rock classifier; development of theoretical statistical methods; development of methods for evaluating and selecting sensors; and experimentation with data mining techniques on the Ames spectral library. The results of this work are being applied at CMU, in particular in the context of the Winter 99 Antarctica expedition in which the classification techniques will be used on the Nomad robot. Conversely, the software developed based on those techniques will continue to be made available to NASA Ames and the data collected from the Nomad experiments will also be made available.

  6. Rock Slope Design Criteria

    Science.gov (United States)

    2010-06-01

    Based on the stratigraphy and the type of slope stability problems, the flat lying, Paleozoic age, sedimentary : rocks of Ohio were divided into three design units: 1) competent rock design unit consisting of sandstones, limestones, : and siltstones ...

  7. Rock slope design guide.

    Science.gov (United States)

    2011-04-01

    This Manual is intended to provide guidance for the design of rock cut slopes, rockfall catchment, and : rockfall controls. Recommendations presented in this manual are based on research presented in Shakoor : and Admassu (2010) entitled Rock Slop...

  8. The Rock Cycle

    Science.gov (United States)

    Singh, Raman J.; Bushee, Jonathan

    1977-01-01

    Presents a rock cycle diagram suitable for use at the secondary or introductory college levels which separates rocks formed on and below the surface, includes organic materials, and separates products from processes. (SL)

  9. Manipulating surface wettability and oil absorbency of diatomite depending on processing and ambient conditions

    Science.gov (United States)

    Özen, İlhan; Şimşek, Süleyman; Okyay, Gamze

    2015-03-01

    In this study, a diatomite sample, which is a natural inorganic mineral with inherently high water and oil absorption capacity, was subjected to grinding before surface modification. Afterwards, the diatomite surface was modified via facile methods using a fluorocarbon (FC) chemical and stearic acid (SA) in addition to the sol-gel fluorosilanization (FS) process. The water and oil wettability, and oil absorbency properties of the unmodified and modified diatomites were investigated in addition to diatomite characterizations such as chemical content, surface area, particle size distribution, morphology, and modification efficiency. It was revealed that the wettability was changed completely depending on the surface modification agent and the media used, while the oil absorbency property surprisingly did not change. On the other hand, the oil absorbency was worsened by the grinding process, whereas the wettability was not affected.

  10. Wettability and Reaction between Solder and Silver Busbar during the Tabbing Process for Silicon Photovoltaic Modules

    Science.gov (United States)

    Lee, Beom-Yong; Hoang, Thi-Lien; Cho, Sung-Bin; Huh, Joo-Youl; Lee, Young-Sik

    2012-10-01

    The soldering quality of a Cu ribbon onto the Ag busbars of solar cells is one of the key factors affecting the cell-to-module loss and durability of a silicon photovoltaic module. In this study, we examined the effects of the surface chemistry and morphology of the screen-printed Ag busbars on the solder wettability and bonding uniformity of the Cu ribbon over the length of the busbar during the tabbing process. The surface of the as-fired Ag busbar was covered by a thin glass layer originating from the glass frit contained in the Ag paste. The presence of the thin glass layer significantly decreased the wettability of the solder, leading to the formation of voided regions at the solder/busbar interface. Although it had only a minor influence on solder wettability, increasing the roughness of the busbar surface resulted in the formation of more voided regions at the solder/busbar interface.

  11. Bio-Inspired Polymeric Structures with Special Wettability and Their Applications: An Overview

    Directory of Open Access Journals (Sweden)

    Zihe Pan

    2017-12-01

    Full Text Available It is not unusual for humans to be inspired by natural phenomena to develop new advanced materials; such materials are called bio-inspired materials. Interest in bio-inspired polymeric superhydrophilic, superhydrophobic, and superoleophobic materials has substantially increased over the last few decades, as has improvement in the related technologies. This review reports the latest developments in bio-inspired polymeric structures with desired wettability that have occurred by mimicking the structures of lotus leaf, rose petals, and the wings and shells of various creatures. The intrinsic role of surface chemistry and structure on delivering superhydrophilicity, superhydrophobicity, and superoleophobicity has been extensively explored. Typical polymers, commonly used structures, and techniques involved in developing bio-inspired surfaces with desired wettability are discussed. Additionally, the latest applications of bio-inspired structures with desired wettability in human activities are also introduced.

  12. The effect of rinsing time periods on wettability of elastomeric impression materials: in vitro study

    Directory of Open Access Journals (Sweden)

    Özlem Acar

    2016-01-01

    Full Text Available OBJECTIVE: The aim of this study was to determine whether different rinsing time periods affected the wettability of polymerized elastomeric impression materials. MATERIALS AND METHOD: Panasil Contact Plus (PCP, Panasil Contact Non-Surfactant (PCNS, Panasil Initial Contact (PIC, Express (EXP and Impregum (IMP impression materials were tested. Standardized samples were rinsed with water for 10 s, 15 s or 20 s, and the wettability was determined by contact angle measurement through an evaluation period of 60 seconds (n=7. Non-rinsed groups were used as control. Measurements were made at 5 time points (at 0, 6, 15, 30 and 60 seconds. Kruskal Wallis test and Conover’s multiple comparison tests were used for all multiple comparisons. Bonferroni adjustment was applied for controlling Type I error (p0.002. CONCLUSION: Rinsing the surfactant-containing polyvinylsiloxane impression materials decreased their wettability, whereas no such effect was seen for the surfactant free polyvinylsiloxane and polyether impression materials.

  13. Structural, morphological, and wettability study of electrochemically anodized 1D TiO2 nanotube arrays

    Science.gov (United States)

    Patil, Jyoti V.; Mali, Sawanta S.; Hong, Chang K.; Kim, Jin H.; Patil, Pramod S.

    2017-10-01

    In the present investigation, anatase titanium dioxide (TiO2) nanotube arrays (NTAs) have been successfully synthesized by a simple and cost-effective electrochemical anodization of titanium (Ti) foil. To investigate the effect of reaction time on the TiO2 NTAs, the reaction time was varied from 6, 12, 18, and 24 h and studied its morphological changes. Furthermore, the synthesized TiO2 NTAs were characterized by X-ray diffraction, FT-Raman spectroscopy, X-ray photospectroscopy, scanning electron microscopy, field-emission scanning electron microscopy, and the wettability measurement to study detailed investigation of structural, morphological, and wettability characteristics. These results demonstrated that the anodization time is strongly affecting on the morphology and wettability of the TiO2 NTAs. In addition, these results will be useful in dye-sensitized solar cell and supercapacitor applications.

  14. My Pet Rock

    Science.gov (United States)

    Lark, Adam; Kramp, Robyne; Nurnberger-Haag, Julie

    2008-01-01

    Many teachers and students have experienced the classic pet rock experiment in conjunction with a geology unit. A teacher has students bring in a "pet" rock found outside of school, and the students run geologic tests on the rock. The tests include determining relative hardness using Mohs scale, checking for magnetization, and assessing luster.…

  15. Influence of biochar and terra preta substrates on wettability and erodibility of soils

    Science.gov (United States)

    Smetanova, A.; Dotterweich, M.; Diehl, D.; Ulrich, U.; Fohrer, N.

    2012-04-01

    Biochar (BC) and terra preta substrates (TPS) have recently been promoted as soil amendments suitable for soil stabilization, soil amelioration and long-term carbon sequestration. BC is a carbon-enriched substance produced by thermal decomposition of organic material. TPS is composed of liquid and solid organic matter, including BC, altered by acid-lactic fermentation. Their effect on wettability, soil erodibility and nutrient discharge through overland flow was studied by laboratory experiments. At water contents between 0 and 100% BC is water repellent, while TPS changes from a wettable into a repellent state. The 5 and 10 vol % mixtures of BC and 10 and 20 vol% mixtures of TPS with sand remain mainly wettable during drying but repellency maxima are shifted to higher water contents with respect to pure sand and are mainly of subcritical nature. The runoff response was dominated by infiltration properties of the substrates rather than their wettability.Only one mixtures (20% TPS) produced more runoff than sandy-loamy soil on a 15% slope at an intensity of 25 mm•h-1. The 10% BC decreased runoff by up to 40%. At higher rainfall intensities (45 and 55 mm•h-1) the 10% TPS7 was up to 35% less erodible than 10% BC. Despite the TPS containing more nutrients, nutrient discharge varied between types of nutrients, slopes, rainfall intensities and mixtures. The application of a 1 cm layer onto the soil surface instead of 10% mixtures is not recommended due to high nutrient concentrations in the runoff and the wettability of pure substrates. The usage of 10% BC in lowland areas with low frequency and low-intensity precipitation and 10% TPS7 in areas with higher rainfall intensities appears to be appropriate and commendable according to current results. However, together with reversibility of repellency, it needs to undergo further examination in the field under different environmental and land use conditions Key words: biochar, terra preta substrate, wettability

  16. DYNAMIC ADHESIVE WETTABILITY OF POPLAR VENEER WITH COLD OXYGEN PLASMA TREATMENT

    OpenAIRE

    Lijuan Tang,; Rong Zhang,; Xiaoyan Zhou,; Mingzhu Pan,; Minzhi Chen,; Xuehui Yang,; Ping Zhou,; Zhao Chen

    2012-01-01

    Effects of cold oxygen plasma treatment on activating the surface of poplar veneers and improving its wettability were investigated. The veneers were treated with cold oxygen plasma for 1, 3, 5, 7, and 9 min, and aged in air for 1, 3, 7, 14, 21, and 28 days. The dynamic adhesive wettability of veneers was assessed using the contact angle, K-value analysis, and surface free energy. The shear strength of three-layer panels produced from untreated and cold oxygen plasma treated veneers was exami...

  17. Enhanced wettability performance of ultrathin ZnO nanotubes by coupling morphology and size effects.

    Science.gov (United States)

    Yang, Peihua; Wang, Kun; Liang, Zhiwen; Mai, Wenjie; Wang, Cheng-xin; Xie, Weiguang; Liu, Pengyi; Zhang, Long; Cai, Xiang; Tan, Shaozao; Song, Jinhui

    2012-09-21

    In this work, we report on the detailed characterization and mechanism analysis of the improved wettability performance of a new type of ZnO nanostructure, the ultrathin ZnO nanotube, whose growth is induced by screw-dislocation. The newly discovered enhanced wettability properties are suggested to be caused by coupling the morphology and size effects of the nanostructured surface. These ultrathin nanotubes with low density and small dimension form a wet-hair-like hierarchical morphology, which shows a further improved superhydrophobic property with an 8.6 ± 1.6° larger contact angle than that of ZnO nanorods due to the morphology effect. In addition, owing to the large surface to volume ratio and increased effective UV-irradiated area of the ultrathin tubular structure, the ZnO nanotubes exhibit ∼5 times faster superhydrophobicity to superhydrophilicity conversion speed than nanorods under 254 nm UV illumination. Furthermore, UV light with a wavelength of 254 nm exhibits ∼40 times faster wettability conversion speed for nanotubes than that of 365 nm, which is suggested to be a result of the band gap shift at the nanoscale. The combined advantages of enhanced superhydrophobicity, improved sensitivity, and faster conversion speed by coupling morphology and size effects of these ZnO nanotubes should give them broad applications in self-cleaning surfaces and wettability switches.

  18. Basic evaluation of typical nanoporous silica nanoparticles in being drug carrier: Structure, wettability and hemolysis.

    Science.gov (United States)

    Li, Jing; Guo, Yingyu

    2017-04-01

    Herein, the present work devoted to study the basic capacity of nanoporous silica nanoparticles in being drug carrier that covered structure, wettability and hemolysis so as to provide crucial evaluation. Typical nanoporous silica nanoparticles that consist of nanoporous silica nanoparticles (NSN), amino modified nanoporous silica nanoparticles (amino-NSN), carboxyl modified nanoporous silica nanoparticles (carboxyl-NSN) and hierachical nanoporous silica nanoparticles (hierachical-NSN) were studied. The results showed that their wettability and hemolysis were closely related to structure and surface modification. Basically, wettability became stronger as the amount of OH on the surface of NSN was higher. Both large nanopores and surface modification can reduce the wettability of NSN. Furthermore, NSN series were safe to be used when they circulated into the blood in low concentration, while if high concentration can not be avoided during administration, high porosity or amino modification of NSN were safer to be considered. It is believed that the basic evaluation of NSN can make contribution in providing scientific instruction for designing drug loaded NSN systems. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Effects of surface wettability and edge geometry on drop motion through an orifice

    Science.gov (United States)

    Bordoloi, Ankur; Longmire, Ellen

    2012-11-01

    In geothermal energy recovery and CO2 sequestration, drops move through a porous structure by displacing a surrounding liquid. Both the pore geometry and surface wettability influence the drop motion. We simplify the pore structure to a thin plate with a circular orifice. The plate is held horizontally inside a rectangular tank filled with silicone oil. Drops of water/glycerin with Bond numbers (Bo) of 1-10 are released above and axisymmetric to the orifice, encountering the plate after reaching their terminal speed. We use high speed imaging to examine the effects of orifice-to-drop diameter ratio (d/D), orifice surface wettability (hydrophilic/hydrophobic) and edge geometry on the passage of drop fluid through the orifice. We generate regime maps for d/D and Bo delineating domains of drop capture, passage, and passage with breakup. For d/D < 1, sharp edges are observed to yield contact between the drop and orifice so that surface wettability influences the subsequent dynamics. On the other hand, rounded edges appear to prevent direct contact so that the dynamics are unaffected by the surface wettability. Supported by DOE (DOE EERE-PMC-10EE0002764).

  20. Effect of wood grain and veneer side on loblolly pine veneer wettability

    Science.gov (United States)

    Todd E. Shupe; Chung Y. Hse; Elvin T. Choong; Leslie H. Groom

    1998-01-01

    Research was initiated to determine the effect of veneer side (tight or loose), and wood grain (earlywood or latewood) on the wettability of loblolly pine veneer. Contact angle measurements were performed with phenol-formaldehyde resin and distilled water. The resin and distilled water showed slightly higher contact angle mean values on the latewood portion for both...

  1. Control of surface wettability using tripodal light-activated molecular motors.

    Science.gov (United States)

    Chen, Kuang-Yen; Ivashenko, Oleksii; Carroll, Gregory T; Robertus, Jort; Kistemaker, Jos C M; London, Gábor; Browne, Wesley R; Rudolf, Petra; Feringa, Ben L

    2014-02-26

    Monolayers of fluorinated light-driven molecular motors were synthesized and immobilized on gold films in an altitudinal orientation via tripodal stators. In this design the functionalized molecular motors are not interfering and preserve their rotary function on gold. The wettability of the self-assembled monolayers can be modulated by UV irradiation.

  2. Contact lenses wettability in vitro: effect of surface-active ingredients.

    Science.gov (United States)

    Lin, Meng C; Svitova, Tatyana F

    2010-06-01

    To investigate the release of surface-active agents (surfactants) from unworn soft contact lenses (SCLs) and their influence on the lens surface wettability in vitro. Surface tension (ST) of blister pack solutions was measured by pendant-drop technique. STs at the air-aqueous interface and contact angles (CAs) of four conventional and seven silicone hydrogel SCLs were evaluated in a dynamic-cycling regime using a modified captive-bubble tensiometer-goniometer. Measurements were performed immediately after removal from blister packs, and after soaking in a glass vial filled with a surfactant-free solution, which was replaced daily for 1 week. Lens surface wettability was expressed as adhesion energy according to Young equation. STs of all blister pack solutions were lower than the reference ST of pure water (72.5 mN/m), indicating the presence of surfactants. When lenses were depleted of surfactants by soaking, the STs for all studied lenses and advancing CAs of selected lenses increased (p lenses were 12 degrees +/- 5 degrees and were not affected by the presence of surfactants. For most of the conventional lenses, the surface wettability was largely dependent on surfactants, and reduced significantly after surfactant depletion. In contrast, most silicone hydrogel lenses exhibited stable and self-sustained surface wettability in vitro. The manufacturer-added surfactants affected wetting properties of all studied SCLs, although to different degrees.

  3. Effects of surfactant treatment on the wettability and wetting rate of a Sphagnum peat growing medium

    NARCIS (Netherlands)

    Dekker, L.W.; Oostindie, K.; Ritsema, C.J.

    2001-01-01

    This study evaluated the effectiveness of a new wetting agent, PsiMATRIC, on the wettability of a Sphagnum peat growing medium. A mixture of Sphagnum peat, perlite and vermiculite treated with 0.26 g of PsiMATRIC per litre was compared with the untreated blend. Water repellency tests (water drop

  4. Creation of wettability contrast patterns on metallic surfaces via pen drawn masks

    Science.gov (United States)

    Choi, Won Tae; Yang, Xiaolong; Breedveld, Victor; Hess, Dennis W.

    2017-12-01

    Micropatterned surfaces with wettability contrast have attracted considerable attention due to potential applications in 2D microfluidics, bioassays, and water harvesting. A simple method to develop wettability contrast patterns on metallic surfaces by using a commercial marker is described. A marker-drawn ink pattern on a copper surface displays chemical resistance to an aqueous solution of sodium bicarbonate and ammonium persulfate, thereby enabling selective nanowire growth in areas where ink is absent. Subsequent ink removal by an organic solvent followed by fluorocarbon film deposition yields a stable hydrophobic/super-hydrophobic patterned copper surface. Using this approach, hydrophobic dot and line patterns were constructed. The adhesion force of water droplets to the dots was controlled by adjusting pattern size, thus enabling controlled droplet transfer between two surfaces. Anisotropy of water droplet adhesion to line patterns can serve as a basis for directional control of water droplet motion. This general approach has also been employed to generate wettability contrast on aluminum surfaces, thereby demonstrating versatility. Due to its simplicity, low cost, and virtual independence of solid surface material, ink marker pens can be employed to create wettability patterns for a variety of applications, in fields as diverse as biomedicine and energy.

  5. Effect of matrix wettability CO2 assisted gas-oil garvity drainage in naturally fractured reservoirs

    NARCIS (Netherlands)

    Amerighasrodashti, A.; Farajzadeh, R.; Shojai Kaveh, N.; Suicmez, S.; Wolf, K.H.A.A.; Bruining, J.

    2015-01-01

    The wettability behavior of the matrix block is one of the major factors controlling the effectiveness of the employed EOR methods in NFRs. Water injection in NFRs with mixed-wet or effectively oil-wet matrix blocks usually results in low oil recoveries. In this case, gas injection is considered to

  6. Contact Lenses Wettability In Vitro: Effect of Surface-Active Ingredients

    Science.gov (United States)

    Lin, Meng C.; Svitova, Tatyana F.

    2010-01-01

    Purpose To investigate the release of surface-active agents (surfactants) from unworn soft contact lenses and their influence on the lens surface wettability in vitro. Methods Surface tension (ST) of blister pack solutions was measured by pendant-drop technique. STs at the air-aqueous interface and contact angles (CAs) of four conventional and seven silicone hydrogel (SiH) soft contact lenses (SCLs) were evaluated in a dynamic-cycling regime using a modified captive-bubble tensiometer-goniometer. Measurements were performed immediately after removal from blister packs, and after soaking in a glass vial filled with a surfactant-free solution, which was replaced daily for one week. Lens surface wettability was expressed as adhesion energy (AE) according to Young’s equation. Results STs of all blister pack solutions were lower than the reference ST of pure water (72.5 mN/m), indicating the presence of surfactants. When lenses were depleted of surfactants by soaking, the STs of all studied lenses and advancing CAs of selected lenses increased (p lenses were 12° ± 5° and were not affected by the presence of surfactants. For most of the conventional lenses, the surface wettability was largely dependent on surfactants, and reduced significantly after surfactant depletion. In contrast, most SiH lenses exhibited stable and self-sustained surface wettability in vitro. Conclusions The manufacturer-added surfactants affected wetting properties of all studied SCLs, although to different degrees. PMID:20400924

  7. Polymer membrane with a mineral coating for enhanced curling resistance and surface wettability.

    Science.gov (United States)

    Yang, Hao-Cheng; Chen, Yi-Fu; Ye, Chen; Jin, Yi-Ning; Li, Hanying; Xu, Zhi-Kang

    2015-08-18

    Zirconia-wrapped membranes were fabricated via a mineralization process on polydopamine/polyethyleneimine-deposited surfaces. The rigid and hydrophilic mineral coating simultaneously endows the membranes with enhanced curling resistance and surface wettability, enabling the membranes to separate oil-in-water emulsions.

  8. Cellular Behavior of Human Adipose-Derived Stem Cells on Wettable Gradient Polyethylene Surfaces

    Directory of Open Access Journals (Sweden)

    Hyun Hee Ahn

    2014-01-01

    Full Text Available Appropriate surface wettability and roughness of biomaterials is an important factor in cell attachment and proliferation. In this study, we investigated the correlation between surface wettability and roughness, and biological response in human adipose-derived stem cells (hADSCs. We prepared wettable and rough gradient polyethylene (PE surfaces by increasing the power of a radio frequency corona discharge apparatus with knife-type electrodes over a moving sample bed. The PE changed gradually from hydrophobic and smooth surfaces to hydrophilic (water contact angle, 90° to ~50° and rough (80 to ~120 nm surfaces as the power increased. We found that hADSCs adhered better to highly hydrophilic and rough surfaces and showed broadly stretched morphology compared with that on hydrophobic and smooth surfaces. The proliferation of hADSCs on hydrophilic and rough surfaces was also higher than that on hydrophobic and smooth surfaces. Furthermore, integrin beta 1 gene expression, an indicator of attachment, and heat shock protein 70 gene expression were high on hydrophobic and smooth surfaces. These results indicate that the cellular behavior of hADSCs on gradient surface depends on surface properties, wettability and roughness.

  9. Influence of surface wettability on competitive protein adsorption and initial attachment of osteoblasts.

    Science.gov (United States)

    Wei, Jianhua; Igarashi, Toshio; Okumori, Naoto; Igarashi, Takayasu; Maetani, Takashi; Liu, Baolin; Yoshinari, Masao

    2009-08-01

    This study investigated the influence of surface wettability on competitive protein adsorption and the initial attachment of osteoblasts. A thin-film coating of hexamethyldisiloxane (HMDSO) and subsequent O(2)-plasma treatment was carried out on substrates with a mirror surface in order to create a wide range of wettabilities. The adsorption behavior of fibronectin (Fn) and albumin (Alb) in both individual and competitive mode, and the initial attachment of mouse osteoblastic cells (MC3T3-E1) over a wide range of wettabilities were investigated. The contact angle of HMDSO coatings without O(2)-plasma treatment against double-distilled water was more than 100 degrees, whereas it dramatically decreased after the O(2)-plasma treatment to almost 0 degrees, resulting in super-hydrophilicity. Individually, Fn adsorption showed a biphasic inclination, whereas Alb showed greater adsorption to hydrophobic surfaces. In the competitive mode, in a solution containing both Fn and Alb, Fn showed greater adsorption on hydrophilic surfaces, whereas Alb predominantly adsorbed on hydrophobic surfaces. The initial attachment of osteoblastic cells increased with an increase in surface wettability, in particular, on a super-hydrophilic surface, which correlated well with Fn adsorption in the competitive mode. These results suggest that Fn adsorption may be responsible for increasing cell adhesion on hydrophilic surfaces in a body fluid or culture media under physiological conditions.

  10. Reactivity and wettability of SiC by Ni and Ni-Si alloys

    Energy Technology Data Exchange (ETDEWEB)

    Rado, C. [INPG, 38 - Saint Martin d`Heres (France). LTPCM; Kalogeropoulou, S. [INPG, 38 - Saint Martin d`Heres (France). LTPCM; Eustathopoulos, N. [INPG, 38 - Saint Martin d`Heres (France). LTPCM

    1996-08-01

    Wettability of SiC by Ni and Ni-Si alloys was studied at 1633K by the sessile drop technique under high vacuum or pure He. It is shown that reactivity in this system can be controlled and even nearly suppressed while obtaining good wetting and strong interface. (orig.)

  11. Wettability of poultry litter biochars at variable pyrolysis temperatures and their impact on soil wettability and water retention relationships

    Science.gov (United States)

    Yi, S. C.; Witt, B.; Guo, M.; Chiu, P.; Imhoff, P. T.

    2012-12-01

    To reduce the impact of poultry farming on greenhouse gas emissions, poultry farming waste - poultry litter - can be converted to biofuel and biochar through slow-pyrolysis, with the biochar added to agricultural soil for nutrient enrichment and carbon sequestration. While biochars from source materials other than poultry litter have been shown to sequester carbon and increase soil fertility, there is considerable variability in biochar behavior - even with biochars created from the same source material. This situation is exacerbated by our limited understanding of how biochars alter physical, chemical, and biological processes in agricultural soils. The focus of this work is to develop a mechanistic understanding of how poultry litter (PL) biochars affect the hydrology, microbial communities, N2O emissions, and nitrogen cycling in agricultural soils. The initial focus is on the impact of PL biochar on soil hydrology. PL from Perdue AgriRecycle, LLC (Seaford, Delaware) was used to produce biochars at pyrolysis temperatures from 300°C to 600°C. To explore the impact of these biochars on soil wettability, the PL biochars were mixed with a 30/40 Accusand in mass fractions from 0% to 100%. The water contact angle was then measured using a goniometer on these sand/biochar mixtures using the sessile drop method and a single layer of sample particles. The PL biochars produced at temperatures between 300°C to 400°C were hydrophobic, while those pyrolized at > 400°C were hydrophilic. Water contact angles for samples with 100% biochar varied systematically with pyrolysis temperature, decreasing from 101.12° to 20.57° as the pyrolysis temperature increased from 300 to 600°C. Even for small amounts of hydrophobic biochar added to the hydrophilic sand, the contact angle of the mixture was altered: for sand/biochar mixtures containing only 2% hydrophobic PL biochar by weight, the contact angle of the mixture increased from ~ 8° (0% biochar) to 20° (2% biochar). For

  12. Microbial Enhanced Oil Recovery and Wettability Research Program. Annual report, FY 1991

    Energy Technology Data Exchange (ETDEWEB)

    Bala, G.A.; Barrett, K.B.; Eastman, S.L.; Herd, M.D.; Jackson, J.D.; Robertson, E.P.; Thomas, C.P.

    1993-09-01

    This report covers research results for fiscal year 1991 for the Microbial Enhanced Oil Recovery (MEOR) and Wettability Research Program conducted by EG&G Idaho, Inc. at the Idaho National Engineering Laboratory ONEL) for the US Department of Energy Idaho Field Office (DOE-ID). The program is funded by the Assistant Secretary of Fossil Energy, and managed by DOE-ID and the Bartlesville Project Office (BPO). The objectives of this multi-year program are to develop MEOR systems for application to reservoirs containing medium to heavy crude oils and to design and implement an industry cost-shared field demonstration project of the developed technology. An understanding of the controlling mechanisms will first be developed through the use of laboratory scale testing to determine the ability of microbially mediated processes to recover oil under reservoir conditions and to develop the design criteria for scale-up to the field. Concurrently with this work, the isolation and characterization of microbial species collected from various locations including target oil field environments is underway to develop more effective oil recovery systems for specific applications. Research focus includes the study of biogenic product and formation souring processes including mitigation and prevention. Souring research performed in FY 1991 also included the development of microsensor probe technology for the detection of total sulfide in collaboration with the Montana State University Center for Interfacial Microbial Process Engineering (CIMPE). Wettability research is a multi-year collaborative effort with the New Mexico Petroleum Recovery Research Center (NMPRRC) at the New Mexico institute of Mining and Technology, Socorro, NM to evaluate reservoir wettability and its effects on oil recovery. Results from the wettability research will be applied to determine if alteration of wettability is a significant contributing mechanism for MEOR systems.

  13. Effects of surface wettability and liquid viscosity on the dynamic wetting of individual drops.

    Science.gov (United States)

    Chen, Longquan; Bonaccurso, Elmar

    2014-08-01

    In this paper, we experimentally investigated the dynamic spreading of liquid drops on solid surfaces. Drop of glycerol water mixtures and pure water that have comparable surface tensions (62.3-72.8 mN/m) but different viscosities (1.0-60.1 cP) were used. The size of the drops was 0.5-1.2 mm. Solid surfaces with different lyophilic and lyophobic coatings (equilibrium contact angle θ(eq) of 0°-112°) were used to study the effect of surface wettability. We show that surface wettability and liquid viscosity influence wetting dynamics and affect either the coefficient or the exponent of the power law that describes the growth of the wetting radius. In the early inertial wetting regime, the coefficient of the wetting power law increases with surface wettability but decreases with liquid viscosity. In contrast, the exponent of the power law does only depend on surface wettability as also reported in literature. It was further found that surface wettability does not affect the duration of inertial wetting, whereas the viscosity of the liquid does. For low viscosity liquids, the duration of inertial wetting corresponds to the time of capillary wave propagation, which can be determined by Lamb's drop oscillation model for inviscid liquids. For relatively high viscosity liquids, the inertial wetting time increases with liquid viscosity, which may due to the viscous damping of the surface capillary waves. Furthermore, we observed a viscous wetting regime only on surfaces with an equilibrium contact angle θ(eq) smaller than a critical angle θ(c) depending on viscosity. A scaling analysis based on Navier-Stokes equations is presented at the end, and the predicted θ(c) matches with experimental observations without any additional fitting parameters.

  14. Exploration of the crystalline underground by extension drilling of the Urach 3 well in the framework of a feasibility study for a hot dry rock demonstration project; Erkundung des kristallinen Untergrunds mit der Vertiefungsbohrung Urach 3 im Rahmen einer Machbarkeitsstudie fuer ein Hot-Dry-Rock-Demonstrationsprojekt

    Energy Technology Data Exchange (ETDEWEB)

    Tenzer, H. [Stadtwerke Bad Urach (Germany); Genter, A.; Hottin, A.M. [BRGM/GIG, Orleans (France)

    1997-12-01

    The prerequisites for specific research into the use of Hot Dry Rock geothermal energy at great depths and temperatures of up to 147 C. In Europe were created with the drilling and completition of the 3334 m deep research drill hole Urach 3 in its phase I (1977/78), and its subsequent extension to 3488 m in phase II (1982/83) within the metamorphic gneiss rock of Urach. A single hole circulation system was tested. Basic results concerning the temperature field, joint system, stress field and hydraulic behavior of the rock were achieved. According to the European HDR guidelines data from depths were a mean reservoir temperature of 175-180 C prevails were necessary to carry out a HDR pilot project. Within the scope of a feasibility study the already existing drill hole Urach 3 was extended from 3488 m to 4445 m depth where the required rock temperature of >170 C was expected. The objective of the project was to determine rock parameters at depth of high temperatures. The bottom hole temperature at true vertical depth of 4394.72 m was determined with 170 C. It can be proved that the temperature gradient is constant with 2.9 K/100 m depth. Due to the results of the investigations it is proposed that the Urach site located in a widespread tectonic horizontal strike-slip system is suitable for a HDR demonstration project. The results can be applied in south German and northern Swiss regions and in other large regions of Europe. Many potential consumers of geothermal energy produced by the HDR concept are situated close around the Urach 3 drill site. (orig./AKF) [Deutsch] Die Forschungsarbeiten zur Weiterentwicklung des Hot-Dry-Rock-Verfahrens begannen am Standort Bad Urach im Jahr 1975. In einer ersten Phase wurde die Bohrung Urach 3 1977/78 auf 3334 m mit einer Gesteinstemperatur von 143 C abgeteuft. Umfangreiche Hydraulische Tests und Frac-Versuche erfolgten. Hiermit wurden die Voraussetzungen fuer die Erkundung des Hot-Dry-Rock-Konzeptes in grossen Tiefen und

  15. Impact of capillarity and wettability on fracturing in granular media

    Science.gov (United States)

    Juanes, R.; Trojer, M.; De Anna, P.

    2016-12-01

    The flow of two or more immiscible phases in porous media is important in natural and industrial processes like geologic CO2 sequestration, enhanced oil recovery, water infiltration in soil, and methane venting from submerged organic-rich sediments. Hydrocarbon recovery from low-permeability geologic formations relies on hydraulic fracturing—a well-known reservoir stimulation technique by which the permeability of the near-wellbore region is enhanced through the opening of fractures within the rock. Here we study this phenomenon experimentally in a horizontal Hele-Shaw cell filled with a granular medium. We inject a low-viscosity fluid into a thin bed of glass beads initially saturated with a more viscous fluid. We investigate the role of three control variables: (1) the injection rate, (2) the confining stress, and (3) the contact angle between the beads and the two fluids. We control the contact angle by carefully choosing the fluid pairs to achieve a wide range of wetting properties, from drainage to imbibition. We image the fluid-fluid displacement and the branching network of fractures via fluorescence tagging, and quantify the displacement of the granular pack by means of particle image velocimetry (PIV). We demonstrate the emergence of fracturing and, crucially, we show that the wetting properties exert a strong, non-monotonic impact on fracture morphology.

  16. Probabilistic Rock Slope Engineering.

    Science.gov (United States)

    1984-06-01

    distances or may reflect errors or uncertainties in sample collection and evaluation. 58. Typical variograms for fracture set properties are illustrated... uncertainties in their measurement and estimation imply the probabilistic nature of parameters re- quired for rock slope engineering. Therefore, statistical...strengths of geologic discontinuities and also by the local stress field. Natural variabilities in these rock mass properties and uncertainties in their

  17. Rock Cycle Roulette.

    Science.gov (United States)

    Schmidt, Stan M.; Palmer, Courtney

    2000-01-01

    Introduces an activity on the rock cycle. Sets 11 stages representing the transitions of an earth material in the rock cycle. Builds six-sided die for each station, and students move to the stations depending on the rolling side of the die. Evaluates students by discussing several questions in the classroom. Provides instructional information for…

  18. Droplet motion in one-component fluids on solid substrates with wettability gradients

    KAUST Repository

    Xu, Xinpeng

    2012-05-11

    Droplet motion on solid substrates has been widely studied not only because of its importance in fundamental research but also because of its promising potentials in droplet-based devices developed for various applications in chemistry, biology, and industry. In this paper, we investigate the motion of an evaporating droplet in one-component fluids on a solid substrate with a wettability gradient. As is well known, there are two major difficulties in the continuum description of fluid flows and heat fluxes near the contact line of droplets on solid substrates, namely, the hydrodynamic (stress) singularity and thermal singularity. To model the droplet motion, we use the dynamic van der Waals theory [Phys. Rev. E 75, 036304 (2007)] for the hydrodynamic equations in the bulk region, supplemented with the boundary conditions at the fluid-solid interface. In this continuum hydrodynamic model, various physical processes involved in the droplet motion can be taken into account simultaneously, e.g., phase transitions (evaporation or condensation), capillary flows, fluid velocity slip, and substrate cooling or heating. Due to the use of the phase field method (diffuse interface method), the hydrodynamic and thermal singularities are resolved automatically. Furthermore, in the dynamic van der Waals theory, the evaporation or condensation rate at the liquid-gas interface is an outcome of the calculation rather than a prerequisite as in most of the other models proposed for evaporating droplets. Numerical results show that the droplet migrates in the direction of increasing wettability on the solid substrates. The migration velocity of the droplet is found to be proportional to the wettability gradients as predicted by Brochard [Langmuir 5, 432 (1989)]. The proportionality coefficient is found to be linearly dependent on the ratio of slip length to initial droplet radius. These results indicate that the steady migration of the droplets results from the balance between the

  19. Development of a Freeze-Dried Fungal Wettable Powder Preparation Able to Biodegrade Chlorpyrifos on Vegetables: e103558

    National Research Council Canada - National Science Library

    Jie Liu; Yue He; Shaohua Chen; Ying Xiao; Meiying Hu; Guohua Zhong

    2014-01-01

    .... Based on a chlorpyrifos-degrading fungus Cladosporium cladosporioides strain Hu-01 (collection number: CCTCC M 20711), a fungal wettable powder preparation was developed aiming to efficiently remove chlorpyrifos residues from vegetables...

  20. Wettability characteristics of carbon steel modified with CO2, Nd:YAG, Excimer and high power diode lasers

    OpenAIRE

    Lawrence, Jonathan; Li, Lin

    2000-01-01

    Interaction of CO2, Nd:YAG, excimer and high power diode laser (HPDL) radiation with the surface of a common mild steel (EN8) was found to effect changes in the wettability characteristics of the steel, namely changes in the measured contact angle. These modifications are related to changes in the surface roughness, changes in the surface oxygen content and changes in the surface energy of the mild steel. The wettability characteristics of the selected mild steel could be controll...

  1. Validation of Methods for the Optical Characterisation of the Wettability of Polymeric Films for Food Packaging

    Directory of Open Access Journals (Sweden)

    Giulio D’Emilia

    2014-01-01

    Full Text Available A methodology is described for the theoretical-experimental evaluation of the measurement uncertainty of the polar and dispersive components of the surface free energy (SFE in polypropylene films; these parameters are related to the film wettability of adhesives and inks. The proposed method is based on the measurement by means of a vision system of the contact angles of liquid drops deposited on the film itself, which allows for obtaining, through mathematical models drawn from the literature, the physical quantities of interest. The effect of the principal influence parameters has been experimentally evaluated, and testing has allowed the defining of the technical procedures readily transferable in the industry. The uncertainty assessment is interesting not only to correctly evaluate experimental data but also to characterise the reproducibility of the effects of techniques for improving the wettability of films, such as surface treatments.

  2. Evidence for Cambrian petroleum source rocks in the Rome trough of West Virginia and Kentucky, Appalachian basin: Chapter G.8 in Coal and petroleum resources in the Appalachian basin: distribution, geologic framework, and geochemical character

    Science.gov (United States)

    Ryder, Robert T.; Harris, David C.; Gerome, Paul; Hainsworth, Timothy J.; Burruss, Robert A.; Lillis, Paul G.; Jarvie, Daniel M.; Pawlewicz, Mark J.; Ruppert, Leslie F.; Ryder, Robert T.

    2014-01-01

    A 130-foot-thick Cambrian black shale sampled from a core between 11,150 and 11,195 feet in the Exxon No. 1 Smith well in Wayne County, W. Va., has been identified as a good to very good source rock. The black shale is located in the Middle Cambrian Rogersville Shale of the Conasauga Group. Total organic carbon (TOC) values of four samples that range from 1.2 to 4.4 weight percent (average 2.6 weight percent) are the highest reported to date in the pre-Knox section of the Rome trough. Although the samples are probably in the zone of gas generation based on their low hydrogen index values (55 to 63) and temperature maximum of second hydrocarbon peak (S2) values of about 465°C, first hydrocarbon peak (S1) values of 0.81 to 2.71 indicate that they contain free extractable hydrocarbons. A bitumen sample extracted from the Rogersville Shale is characterized by (1) a broad spectrum of n-alkanes from n-C11 through n-C30, (2) strong odd-carbon predominance in the n-C13 to n-C19 range, and (3) small but detectable amounts of isoprenoids pristane and phytane. The strong odd-carbon predominance of the n-C15 to n-C19 n-alkanes is commonly attributed to the Ordovician alga Gloeocapsomorpha prisca. This occurrence of G. prisca is among the first to be reported in Cambrian rocks. Thin black shale beds collected from the Lower to Middle Cambrian Rome Formation in the Texaco No. 1 Kirby well in Garrard County, Ky., have TOC values as high as 3.2 percent, hydrogen index values as high as 417, and bitumen extract characteristics similar to the Rogersville Shale.

  3. Deposit buildup on prosthetic eye material (in vitro) and its effect on surface wettability.

    Science.gov (United States)

    Pine, Keith Raymond; Sloan, Brian; Han, Kyuyeon Ivy; Swift, Simon; Jacobs, Robert John

    2013-01-01

    The aim of this in-vitro study was to investigate the effect of different polishing standards on prosthetic eye material (poly(methyl methacrylate) [PMMA]) on surface wettability and the rate of protein and lipid buildup. Sample disks (12 mm diameter × 1 mm thickness) of PMMA were polished to three different standards of surface finish: low, normal, and optical quality contact lens standard. The sample disks were incubated in a protein-rich artificial tear solution (ATS) for the following periods of time: 1 second, 30 minutes, 1 hour, 4 hours, 24 hours, and 14 days. Surface wettability was measured with a goniometer before and after protein deposits were removed. One-way analysis of variance and paired-samples t-test were used for the statistical analysis. Between 13.64 and 62.88 μg of protein adhered to the sample disks immediately upon immersion in ATS. Sample disks with the highest polish attracted less protein deposits. The sample disks polished to optical quality contact lens standard were more wettable than those less highly polished, and wettability significantly decreased following removal of protein deposits. The addition of lipids to protein-only ATS made no difference to the amount of protein deposited on the sample disks for any of the standards of surface polish tested. The findings are consistent with the results of the in-vivo investigation reported previously by the authors. Our view that the minimum standard of polish for prosthetic eyes should be optical quality contact lens standard and that deposits on PMMA prosthetic eyes improve the lubricating properties of the socket fluids has been reinforced by the results of this study.

  4. Wettability, structural and optical properties investigation of TiO{sub 2} nanotubular arrays

    Energy Technology Data Exchange (ETDEWEB)

    Zalnezhad, E., E-mail: erfan@hanyang.ac.kr [Department of Mechanical Convergence Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Maleki, E. [Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); Banihashemian, S.M. [Low Dimensional Materials Research Center, Department of Physics, Science Faculty, University Malaya, 50603 Kuala Lumpur (Malaysia); Park, J.W. [Department of Materials Science and Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Kim, Y.B. [Department of Mechanical Convergence Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Sarraf, M.; Sarhan, A.A.D.M.; Ramesh, S. [Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2016-06-15

    Graphical abstract: FESEM images of the TiO 2 nanotube layers formed at 0.5 wt% NH4F/ glycerol. - Highlights: • Structural property investigation of TiO{sub 2} nanotube. • Evaluation of wettability of TiO{sub 2} nanotube. • Study on optical properties of TiO{sub 2} nanotube. • The effect of anatase phase on optical and wettability properties of TiO{sub 2.} - Abstract: In this study, the effect of microstructural evolution of TiO{sub 2} nanotubular arrays on wettability and optical properties was investigated. Pure titanium was deposited on silica glass by PVD magnetron sputtering technique. The Ti coated substrates were anodized in an electrolyte containing NH{sub 4}F/glycerol. The structures of the ordered anodic TiO{sub 2} nanotubes (ATNs) as long as 175 nm were studied using field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). The result shows a sharp peak in the optical absorbance spectra around the band gap energy, 3.49–3.42 eV for annealed and non-annealed respectively. The thermal process induced growth of the grain size, which influence on the density of particles and the index of refraction. Furthermore, the wettability tests' result displays that the contact angle of intact substrate (θ = 74.7°) was decreased to 31.4° and 17.4° after anodization for amorphous and heat treated (450 °C) ANTs coated substrate, respectively.

  5. Surface roughness and wettability of enamel and dentine surfaces prepared with different dental burs.

    Science.gov (United States)

    Al-Omari, W M; Mitchell, C A; Cunningham, J L

    2001-07-01

    The aim of dental adhesive restorations is to produce a long lasting union between the restoration and the tooth structure. This bond depends on many variables including the geometry of the preparation and the type of bonding agent or luting cement. It is therefore suggested that the topography of the tooth surface may influence the wettability and the bonding quality of adhesive systems. This study measured the surface roughness and wettability of enamel and dentine after preparation with different dental burs. The mesial and distal surfaces of 15 extracted sound human premolar teeth were prepared with a tungsten carbide crown bur, a diamond bur and a tungsten carbide finishing bur and finished in enamel or dentin, respectively. The prepared surfaces were analysed with a surface profilometer and scanning electron microscopy (SEM). The contact angle of distilled water on each of the prepared surfaces was used as the measure of wettability. The differences in average surface roughness (Ra) were significant between the rotary instrument groups, as revealed by a two-way ANOVA test. No differences were detected between enamel and dentine surfaces prepared with the same type of dental bur. The smoothest surfaces were those completed with tungsten carbide finishing burs. The diamond bur preparations were intermediate in the roughness assessment and the tungsten carbide crown burs gave the roughest surfaces. There were no significant differences in the contact angle measurements for the various groups. It was concluded that the surface roughness of enamel and dentine prepared by different rotary instruments had no significant influence on the wettability of distilled water on these surfaces.

  6. Contact angles and wettability of ionic liquids on polar and non-polar surfaces.

    Science.gov (United States)

    Pereira, Matheus M; Kurnia, Kiki A; Sousa, Filipa L; Silva, Nuno J O; Lopes-da-Silva, José A; Coutinho, João A P; Freire, Mara G

    2015-12-21

    Many applications involving ionic liquids (ILs) require the knowledge of their interfacial behaviour, such as wettability and adhesion. In this context, herein, two approaches were combined aiming at understanding the impact of the IL chemical structures on their wettability on both polar and non-polar surfaces, namely: (i) the experimental determination of the contact angles of a broad range of ILs (covering a wide number of anions of variable polarity, cations, and cation alkyl side chain lengths) on polar and non-polar solid substrates (glass, Al-plate, and poly-(tetrafluoroethylene) (PTFE)); and (ii) the correlation of the experimental contact angles with the cation-anion pair interaction energies generated by the Conductor-like Screening Model for Real Solvents (COSMO-RS). The combined results reveal that the hydrogen-bond basicity of ILs, and thus the IL anion, plays a major role through their wettability on both polar and non-polar surfaces. The increase of the IL hydrogen-bond accepting ability leads to an improved wettability of more polar surfaces (lower contact angles) while the opposite trend is observed on non-polar surfaces. The cation nature and alkyl side chain lengths have however a smaller impact on the wetting ability of ILs. Linear correlations were found between the experimental contact angles and the cation-anion hydrogen-bonding and cation ring energies, estimated using COSMO-RS, suggesting that these features primarily control the wetting ability of ILs. Furthermore, two-descriptor correlations are proposed here to predict the contact angles of a wide variety of ILs on glass, Al-plate, and PTFE surfaces. A new extended list is provided for the contact angles of ILs on three surfaces, which can be used as a priori information to choose appropriate ILs before a given application.

  7. Structural, surface wettability and antibacterial properties of HPMC-ZnO nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Rao, B. Lakshmeesha; Asha, S.; Madhukumar, R.; Latha, S.; Gowda, Mahadeva; Shetty, G. Rajesha; Sangappa, E-mail: syhalabhavi@yahoo.co.in [Department of Studies in Physics, Mangalore University, Mangalagangotri - 574199 (India); Chandra, K. Sharath; Naik, Prashantha [Department of Biosciences, Mangalore University, Mangalagangotri - 574199 (India)

    2014-04-24

    The developed hydroxypropyl methylcellulose (HPMC)/Zinc oxide (ZnO) nanocomposite films were examined for structural property and surface wettability using X-ray diffraction and contact angle measurement. Antibacterial activity of these films was evaluated as a function of ZnO concentration. The microstructuralline parameters ( and (g in %)) decreased with increasing concentration of ZnO nanoparticles and there was increase in hydrophilicity. Addition of ZnO nanoparticles in films resulted in antimicrobial activity against tested microorganisms.

  8. Effect of coating current density on the wettability of electrodeposited copper thin film on aluminum substrate

    Directory of Open Access Journals (Sweden)

    Arun Augustin

    2016-09-01

    Full Text Available Copper is the only one solid metal registered by the US Environmental Protection Agency as an antimicrobial touch surface. In touch surface applications, wettability of the surface has high significance. The killing rate of the harmful microbes depends on the wetting of pathogenic solution. Compared to the bulk copper, coated one on aluminum has the advantage of economic competitiveness and the possibility of manufacturing complex shapes. In the present work, the copper coating on the aluminum surface has successfully carried out by electrodeposition using non cyanide alkaline bath. To ensure good adhesion strength, the substrate has been pre-zincated prior to copper deposition. The coating current density is one of the important parameters which determine the nucleation density of the copper on the substrate. To understand the effect of current density on wettability, the coating has done at different current densities in the range of 3 A dm−2 to 9 A dm−2 for fixed time interval. The grain size has been measured from TEM micrographs and showed that as current density increases, grain size reduces from 62 nm to 35 nm. Since the grain size reduces, grain boundary volume has increases. As a result the value of strain energy (calculated by Williamson–Hall method has increased. The density of nodular morphology observed in SEM analysis has been increased with coating current density. Further, wettability studies with respect to double distilled water on the electrodeposited copper coatings which are coated at different current densities are carried out. At higher current density the coating is more wettable by water because at these conditions grain size of the coating decreases and morphology of grain changes to a favorable dense nodularity.

  9. Soil wettability can be explained by the chemical composition of particle interfaces - An XPS study

    OpenAIRE

    Woche, Susanne K.; Goebel, Marc-O.; Mikutta, Robert; Schurig, Christian; Kaestner, Matthias; Guggenberger, Georg; Bachmann, J?rg

    2017-01-01

    Soil wettability (quantified in terms of contact angle, CA) is crucial for physical, chemical, and biological soil functioning. As the CA is determined by components present within the outmost nanometer of particles, this study applied X-ray photoelectron spectroscopy (XPS) with a maximum analysis depth of 10 nm to test the relationship between CA and surface elemental composition, using soil samples from a chronosequence where CA increased from 0° (0 yrs) to about 98° (120 yrs). Concurrently...

  10. Influence of thin fluoropolymer film deposition on wettability of the silicon oxide nanowires array

    Directory of Open Access Journals (Sweden)

    Baranov Evgeniy

    2016-01-01

    Full Text Available In this work, we studied influence of fluoropolymer thin film deposition on wettability of the silicon oxide nanowires array. Deposition of fluoropolymer coating on the silicon oxide nanowires array changes the surface properties from hydrophilic to hydrophobic, and micro and nano scale surface roughness does not change significantly. In addition, it was shown that the deposition of fluoropolymer coating on nanowires protects the nanostructures from bundling together as a result of the attractive capillary forces that arise during evaporative drying.

  11. Morphing and vectoring impacting droplets by means of wettability-engineered surfaces

    OpenAIRE

    Schutzius, Thomas M.; Graeber, Gustav; Elsharkawy, Mohamed; Oreluk, James; Megaridis, Constantine M.

    2014-01-01

    Driven by its importance in nature and technology, droplet impact on solid surfaces has been studied for decades. To date, research on control of droplet impact outcome has focused on optimizing pre-impact parameters, e.g., droplet size and velocity. Here we follow a different, post-impact, surface engineering approach yielding controlled vectoring and morphing of droplets during and after impact. Surfaces with patterned domains of extreme wettability (high or low) are fabricated and implemen...

  12. Addition of silver nanoparticles reduces the wettability of methacrylate and silorane-based composites

    Directory of Open Access Journals (Sweden)

    Shahin Kasraei

    2012-12-01

    Full Text Available Incorporation of silver nanoparticles into composite resins is recommended for their reported antibacterial properties, but this incorporation can affect the wettability of such materials. Therefore, this study evaluated the effect of nano-silver addition to silorane-based and methacrylate-based composites on their contact angle. Nano-silver particles were added to Z250 (methacrylate-based and P90 (silorane-based composites at 0.5% and 1% by weight. The control group had no additions. SEM-EDX analysis was performed to confirm the homogeneity of the nano-silver distribution. Seventy-two composite discs were prepared and standardized to the identical surface roughness values, and then distributed randomly into 6 groups containing 12 samples each (N = 12. Two random samples from each group were observed by atomic force microscopy. Distilled water contact angle measurements were performed for the wettability measurement. Two-way ANOVA, followed by the Tukey-HSD test, with a significance level of 5%, were used for data analysis. It was observed that wettability was significantly different between the composites (p = 0.0001, and that the addition of nano-silver caused a significant reduction in the contact angle (p = 0.0001. Wettability varied depending on the concentration of the nano silver (p = 0.008. Silorane-based composites have a higher contact angle than methacrylate-based composites. Within the limitations of this study, it can be concluded that the addition of 0.5% nano-silver particles to the composites caused a decrease in the contact angle of water.

  13. Wettability of dentin after Yb:KYW thin-disk femtosecond ablation.

    Science.gov (United States)

    Liu, Jing; Lü, Peijun; Sun, Yuchun; Wang, Yong

    2015-08-01

    The aim of this study was to quantitatively evaluate the wettability of dentin after Yb:KYW thin-disk femtosecond-pulsed laser ablation by measuring the contact angle. Different laser parameters were used including different fluences (F), scanning speeds, and scanning line spacings. Crowns of 15 extracted human teeth were cut longitudinally into slices approximately 1.5-mm thick with a cutting instrument. The samples were randomly divided into ten groups (n = 3/group). Samples in groups 1-8 were irradiated with a femtosecond-pulsed laser. The dentin samples were fixed on a stage at the focal plane, and the laser beam irradiated the samples through a galvanometric scanning system so rectangular movement could be achieved. Samples in groups 9 and 10 were prepared with grinding instruments. Following ablation and preparation, the samples were examined for contact angle with an optical contact angle measuring instrument. The results showed that scanning speed and scanning line spacing had little influence on the wettability of dentin following femtosecond-pulsed laser ablation, except when F = 6 J/cm(2). For six out of the eight laser ablation groups, when a lower fluence was used, the dentin contact angle was higher and vice versa. Most of the dentin which had been ablated using the femtosecond-pulsed laser had improved wettability compared to samples prepared with the grinding instruments. This study showed that various laser fluences, scanning speeds, and scanning line spacings can alter dentin wettability. Therefore, adequate parameters should be chosen to achieve proper therapeutic benefits.

  14. Fast light-induced reversible wettability of a zinc oxide nanorod array coated with a thin gold layer

    Science.gov (United States)

    Wei, Yuefan; Du, Hejun; Kong, Junhua; Tran, Van-Thai; Koh, Jia Kai; Zhao, Chenyang; He, Chaobin

    2017-11-01

    Zinc oxide (ZnO) has gained much attention recently due to its excellent physical and chemical properties, and has been extensively studied in energy harvesting applications such as photovoltaic and piezoelectric devices. In recent years, its reversible wettability has also attracted increasing interest. The wettability of ZnO nanostructures with various morphologies has been studied. However, to the best of our knowledge, there is still a lack of investigations on further modifications on ZnO to provide more benefits than pristine ZnO. Comprehensive studies on the reversible wettability are still needed. In this study, a ZnO nanorod array was prepared via a hydrothermal process and subsequently coated with thin gold layers with varied thickness. The morphologies and structures, optical properties and wettability were investigated. It is revealed that the ZnO-Au system possesses recoverable wettability upon switching between visible-ultraviolet light and a dark environment, which is verified by the contact angle change. The introduction of the thin gold layer to the ZnO nanorod array effectively increases the recovery rate of the wettability. The improvements are attributed to the hierarchical structures, which are formed by depositing thin gold layers onto the ZnO nanorod array, the visible light sensitivity due to the plasmonic effect of the deposited gold, as well as the fast charge-induced surface status change upon light illumination or dark storage. The improvement is beneficial to applications in environmental purification, energy harvesting, micro-lenses, and smart devices.

  15. Water-wettable polypropylene fibers by facile surface treatment based on soy proteins.

    Science.gov (United States)

    Salas, Carlos; Genzer, Jan; Lucia, Lucian A; Hubbe, Martin A; Rojas, Orlando J

    2013-07-24

    Modification of the wetting behavior of hydrophobic surfaces is essential in a variety of materials, including textiles and membranes that require control of fluid interactions, adhesion, transport processes, sensing, etc. This investigation examines the enhancement of wettability of an important class of textile materials, viz., polypropylene (PP) fibers, by surface adsorption of different proteins from soybeans, including soy flour, isolate,glycinin, and β-conglycinin. Detailed investigations of soy adsorption from aqueous solution (pH 7.4, 25 °C) on polypropylene thin films is carried out using quartz crystal microbalance (QCM) and surface plasmon resonance (SPR). A significant amount of protein adsorbs onto the PP surfaces primarily due to hydrophobic interactions. We establish that adsorption of a cationic surfactant, dioctadecyldimethylammonium bromide (DODA) onto PP surfaces prior to the protein deposition dramatically enhances its adsorption. The adsorption of proteins from native (PBS buffer, pH 7.4, 25 °C) and denatured conditions (PBS buffer, pH 7.4, 95 °C) onto DODA-treated PP leads to a high coverage of the proteins on the PP surface as confirmed by a significant improvement in water wettability. A shift in the contact angle from 128° to completely wettable surfaces (≈0°) is observed and confirmed by imaging experiments conducted with fluorescence tags. Furthermore, the results from wicking tests indicate that hydrophobic PP nonwovens absorb a significant amount of water after protein treatment, i.e., the PP-modified surfaces become completely hydrophilic.

  16. A study on air bubble wetting: Role of surface wettability, surface tension, and ionic surfactants

    Science.gov (United States)

    George, Jijo Easo; Chidangil, Santhosh; George, Sajan D.

    2017-07-01

    Fabrication of hydrophobic/hydrophilic surfaces by biomimicking nature has attracted significant attention recently due to their potential usage in technologies, ranging from self-cleaning to DNA condensation. Despite the potential applications, compared to surfaces of tailored wettability, less attention has been paid towards development and understanding of air bubble adhesion and its dynamics on surfaces with varying wettability. In this manuscript, following the commonly used approach of oxygen plasma treatment, polydimethylsiloxane surfaces with tunable wettability are prepared. The role of plasma treatment conditions on the surface hydrophilicity and the consequent effect on adhesion dynamics of an underwater air bubble is explored for the first time. The ATR-FTIR spectroscopic analysis reveals that the change in hydrophilicity arises from the chemical modification of the surface, manifested as Si-OH vibrations in the spectra. The thickness of the formed thin liquid film at the surface responsible for the experimentally observed air bubble repellency is estimated from the augmented Young-Laplace equation. The concentration dependent studies using cationic as well as anionic surfactant elucidate that the reduced surface tension of the aqueous solution results in a stable thicker film and causes non-adherence of air bubble to the aerophilic surface. Furthermore, the study carried out to understand the combined effect of plasma treatment and surfactants reveals that even below critical micelle concentration, a negatively charged surface results in air bubble repellency for the anionic surfactant, whereas only enhanced air bubble contact angle is observed for the cationic surfactant.

  17. Wettability modification of human tooth surface by water and UV and electron-beam radiation

    Energy Technology Data Exchange (ETDEWEB)

    Tiznado-Orozco, Gaby E., E-mail: gab0409@gmail.com [UMET, Bâtiment C6, Université de Lille 1, Sciences et Technologies, 59650 Villeneuve d' Ascq (France); Unidad Académica de Odontología, Universidad Autónoma de Nayarit, Edificio E7, Ciudad de la Cultura “Amado Nervo”, C.P. 63190 Tepic, Nayarit (Mexico); Reyes-Gasga, José, E-mail: jreyes@fisica.unam.mx [UMET, Bâtiment C6, Université de Lille 1, Sciences et Technologies, 59650 Villeneuve d' Ascq (France); Instituto de Física, UNAM, Circuito de la Investigación s/n, Ciudad Universitaria, 04510 Coyoacan, México, D.F. (Mexico); Elefterie, Florina, E-mail: elefterie_florina@yahoo.com [UMET, Bâtiment C6, Université de Lille 1, Sciences et Technologies, 59650 Villeneuve d' Ascq (France); Beyens, Christophe, E-mail: christophe.beyens@ed.univ-lille1.fr [UMET, Bâtiment C6, Université de Lille 1, Sciences et Technologies, 59650 Villeneuve d' Ascq (France); Maschke, Ulrich, E-mail: Ulrich.Maschke@univ-lille1.fr [UMET, Bâtiment C6, Université de Lille 1, Sciences et Technologies, 59650 Villeneuve d' Ascq (France); Brès, Etienne F., E-mail: etienne.bres@univ-lille1.fr [UMET, Bâtiment C6, Université de Lille 1, Sciences et Technologies, 59650 Villeneuve d' Ascq (France)

    2015-12-01

    The wettability of the human tooth enamel and dentin was analyzed by measuring the contact angles of a drop of distilled water deposited on the surface. The samples were cut along the transverse and longitudinal directions, and their surfaces were subjected to metallographic mirror-finish polishing. Some samples were also acid etched until their microstructure became exposed. Wettability measurements of the samples were done in dry and wet conditions and after ultraviolet (UV) and electron beam (EB) irradiations. The results indicate that water by itself was able to increase the hydrophobicity of these materials. The UV irradiation momentarily reduced the contact angle values, but they recovered after a short time. EB irradiation raised the contact angle and maintained it for a long time. Both enamel and dentin surfaces showed a wide range of contact angles, from approximately 10° (hydrophilic) to 90° (hydrophobic), although the contact angle showed more variability on enamel than on dentin surfaces. Whether the sample's surface had been polished or etched did not influence the contact angle value in wet conditions. - Highlights: • Human tooth surface wettability changes in dry/wet and UV/EB radiation conditions. • More variability in contact angle is observed on enamel than on dentin surfaces. • Water by itself increases the hydrophobicity of the human tooth surface. • UV irradiation reduces momentarily the human tooth surface hydrophobicity. • EB irradiation increases and maintains the hydrophobicity for a long time.

  18. The effect of reflow process variables on the wettability of lead-free solders

    Science.gov (United States)

    Melton, Cindy

    1993-07-01

    A quantitative dynamic solder wettability measurement was utilized to evaluate the effects of reflow processing on the wettability parameters associated with the lead-free solders 96.5Sn-3.5Ag and 58Bi-42Sn. Solder wettability was determined with respect to the final degree of spread and the extent of solder wetting onto the terminal areas of surface-mount components. The solder alloy composition of 96.5Sn-3.5Ag exhibited better wetting characteristics than the 58Bi-42Sn alloy. This wetting behavior was enhanced under the reflow conditions of a nitrogen atmosphere and the use of a gold metallization. The wetting of the conventional 63Sn-37Pb solder alloy was improved over the comparatively processed 58Bi-42Sn alloy. However, the 63Sn-37Pb solder alloy displayed a greater sensitivity to reflow atmosphere than the 96.5Sn-3.5Ag alloy, which generally exhibited better wetting characteristics than the Sn-Pb alloy.

  19. Rapidly switched wettability of titania films deposited by dc magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Shirolkar, Mandar; Abyaneh, Majid Kazemian; Singh, Akanksha; Kulkarni, Sulabha [DST Unit on Nanoscience, Department of Physics, University of Pune (India); Tomer, Anju; Choudhary, Ram; Sathe, Vasant; Phase, Deodatta [UGC-DAE Consortium for Scientific Research Indore Centre, University Campus, Khandwa Road, Indore (India)], E-mail: skk@physics.unipune.ernet.in

    2008-08-07

    Rapid switching (5-15 minutes) in the wettability of titania (TiO{sub 2}) thin films in the anatase phase has been observed after UV irradiation. The film surface becomes superhydrophilic when exposed to UV radiation. The relationship between wettability, thickness and crystallinity of TiO{sub 2} films has been investigated. Amorphous and anatase TiO{sub 2} thin films have been deposited by varying the argon to oxygen gas ratio, using the reactive dc magnetron sputtering technique. It was found that the gas ratio primarily affects thickness, crystallinity, morphology and wettability of the films. The highest contact angle that has been reported so far, namely, 170 deg. -176 deg., has been observed for film thickness varying from 112-500 nm in the case of pristine anatase TiO{sub 2} films. On the other hand, amorphous films show a variation in the contact angle from 120 deg. to 140 deg. as the thickness varied from 70 to 145 nm. The deposition is extremely robust and has an ultralow hysteresis in the contact angle. The films exhibit a morphology similar to the lotus leaf and the water hyacinth.

  20. Influence of plasma treatment on wettability and scratch resistance of Ag-coated polymer substrates

    Directory of Open Access Journals (Sweden)

    Wojcieszak Damian

    2016-06-01

    Full Text Available Rapid progress in thin-film coatings based on metals, which can be deposited on polymers, has been recently observed. In this work discussion on the properties of modified polymers and silver thin films deposited on polytetrafluoroethylene (PTFE and polycarbonate (PC substrates has been presented. Surface of these polymer substrates were exposed to argon plasma discharge. Additionally, silver thin films were deposited on their surface by electron beam evaporation method. The surfaces of the modified polymers were studied by different methods, i.e. topography, wettability and scratch resistance measurements were performed. The ageing effect of treated substrates was also discussed. It was shown that plasma modification of PTFE and PC substrates increased wettability of their surfaces. The value of water contact angle decreased of about 40 % and 25 % for PTFE and PC surface, respectively. The change of hydrophobic to hydrophilic properties was observed. Plasma modification of substrates improved adhesion between silver coating and polymer substrates. However, it did not influence wettability of Ag coating.

  1. Effects of Surface Wettability and Roughness on the Heat Transfer Performance of Fluid Flowing through Microchannels

    Directory of Open Access Journals (Sweden)

    Jing Cui

    2015-06-01

    Full Text Available The surface characteristics, such as wettability and roughness, play an important role in heat transfer performance in the field of microfluidic flow. In this paper, the process of a hot liquid flowing through a microchannel with cold walls, which possesses different surface wettabilities and microstructures, is simulated by a transient double-distribution function (DDF two-phase thermal lattice Boltzmann BGK (LBGK model. The Shan-Chen multiphase LBGK model is used to describe the flow field and the independent distribution function is introduced to solve the temperature field. The simulation results show that the roughness of the channel wall improves the heat transfer, no matter what the surface wettability is. These simulations reveal that the heat exchange characteristics are directly related to the flow behavior. For the smooth-superhydrophobic-surface flow, a gas film forms that acts as an insulating layer since the thermal conductivity of the gas is relatively small in comparison to that of a liquid. In case of the rough-superhydrophobic-surface flow, the vortex motion of the gas within the grooves significantly enhances the heat exchange between the fluid and wall.

  2. Electrical potential induced switchable wettability of super-aligned carbon nanotube films

    Science.gov (United States)

    Zhang, Guang; Duan, Zheng; Wang, Qinggong; Li, Long; Yao, Wei; Liu, Changhong

    2018-01-01

    Controlling of the wettability of micro-nano scale surfaces not only plays important roles in basic science but also presents some significant applications in interference shielding materials, microfluidics and phase-change heat transfer enhancement, etc. Here, the superhydrophobic super-aligned carbon nanotube (SACNT) films are firstly obtained by the chemical vapor deposition method and the annealing process. Then their wettabilities are in-situ switched by the electrowetting strategy. Specifically, the fascinating transformation of superhydrophobicity to the superhydrophilicity is achieved by exerting external DC voltages across the CNT-liquid interfaces, and the transitions of Cassie-to-Wenzel states are observed on the multilayer SACNT films. In addition, the electrowetting induced salt absorption of the porous SACNT is also reported here. Finally, the threshold voltages of the electrowetting behaviors for different liquids on the SACNT films and unit capacitances across the CNT-liquid interfaces are obtained, which reveal that the SACNT films have much more outstanding electrowetting properties than the previously reported works. Our approach reported here demonstrates that the wettability of SACNT films could be simply, effectively and in-situ controlled by the electrowetting method, which will have many profound implications in numerous applications such as phase-change heat transfer enhancement, optical lens with variable focal length and microfluidics, etc.

  3. Substrate material affects wettability of surfaces coated and sintered with silica nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Kang; Zeng, Hansong [Laboratory for Biomedical Microsystems, Department of Biomedical Engineering, The Ohio State University, Columbus, OH (United States); Zhao, Yi, E-mail: zhao.178@osu.edu [Laboratory for Biomedical Microsystems, Department of Biomedical Engineering, The Ohio State University, Columbus, OH (United States)

    2013-05-15

    Silica nanoparticles coating and sintering is a widely-used approach for creating hydrophobic and superhydrophobic surfaces. The role of substrate material in this process, however, has not been thoroughly investigated. In this work, the role of substrate material is examined by measuring surface wettability of three different substrate materials (glass, polyimide and copper) under systematically varied conditions. These surfaces are modulated from hydrophilic (water contact angle (WCA) < 90°) to superhydrophobic (WCA > 150°) by coating and sintering silica nanoparticles, followed by assembling a layer of fluorine compound. Static WCA characterization shows that surface wettability is not solely dependent on the concentration of the coating colloidal, but is also on the substrate material. In particular, copper substrate exhibits a larger WCA than glass and polyimide substrates. Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDS) and Atomic Force Microscopy (AFM) characterizations show that the substrate material-dependent wettability is attributed to thermal-induced nanostructures on the copper surface, which contributes to the hierarchical micro-/nano- topography. This finding is important for designing hydrophobic/superhydrophobic surfaces comprised of different materials, especially those that would experience thermal cycles in surface functionalization and subsequent use.

  4. The Effect of Nano-ZnO Surface Wettability on Modulating Protein Adsorption

    Science.gov (United States)

    Hu, Qian; Ding, Yadan; Shao, Hong; Cong, Tie; Yang, Xiaoguang; Hong, Xia

    2017-07-01

    Although surface wettability plays a major role in regulating protein adsorption and nanostructured ZnO has shown great potential in various biomedical fields, few reports have examined the influence of nano-ZnO surface wettability on protein adsorption. Herein, we explored the adsorption behavior of bovine serum albumin (BSA) on the superhydrophilic, hydrophilic, hydrophobic and superhydrophobic nano-ZnO surfaces. The adsorption amount of BSA increased with increase of hydrophilicity because of increased adsorption sites on the hydrophilic surface. The protein adsorption was proved to occur along with the desorption and conformational changes by well-fitted kinetic adsorption curves with the Spreading Particle Model and Fourier transformation infrared spectral analysis. The rates of BSA adsorption and desorption increased with hydrophobicity of the ZnO surfaces, which was considered to be related with the energy barrier created by water bound to the ZnO surfaces via hydrogen bonding. The rate of conformational change varied in a complex way, which might be influenced by the surface wettability of ZnO and some other factors. The present work may open up a new avenue to design nano-bio interfacial materials for advanced biological study and clinical applications.

  5. Special wettable nanostructured copper mesh achieved by a facile hot water treatment process

    Science.gov (United States)

    Saadi, Nawzat S.; Hassan, Laylan B.; Brozak, Matt; Karabacak, Tansel

    2017-09-01

    In this research, a special wettable copper mesh with superhydrophobicity and superoleophilicity properties is reported using a low-cost, eco-friendly, rapid, and scalable synthesis method. Hot water treatment (HWT) method is used to integrate the micro-textured copper mesh surface with a nanoscale roughness to achieve a hierarchical micro-nano structured surface. The surface energy of the nanoscale roughened copper mesh reduced by coating the hot water treated mesh with polymer ligands containing thiol or fluorine functional groups of low energy. Surface morphology characterization showed the formation of copper oxide nanostructures on the mesh surface by hot water process performed at 95 °C and under a low dissolved oxygen condition. X-ray diffraction patterns reveal the development of stable, uniformly distributed, and compactly arranged, cubic and plate-like nanostructures of cuprous oxide (Cu2O) on the copper mesh surface. The surface wettability of the as-prepared copper mesh was assessed by contact angle (CA) measurement for water and several oils and organic solvents. CA values showed the formation of special wettable copper mesh surface with superhydrophobic property with water contact angle of about 157° and superoleophilic property with oil contact angle as low as 0°. In addition, the effect of the mesh’s geometry on the wetting property was examined through correlations between wire diameter, pore size, and optimal values for the highest water CA.

  6. Long-range spontaneous droplet self-propulsion on wettability gradient surfaces.

    Science.gov (United States)

    Liu, Chaoran; Sun, Jing; Li, Jing; Xiang, Chenghao; Che, Lufeng; Wang, Zuankai; Zhou, Xiaofeng

    2017-08-08

    The directional and long-range droplet transportation is of great importance in microfluidic systems. However, it usually requires external energy input. Here we designed a wettability gradient surface that can drive droplet motion by structural topography. The surface has a wettability gradient range of over 150° from superhydrophobic to hydrophilic, which was achieved by etching silicon nanopillars and adjusting the area of hydrophilic silicon dioxide plane. We conducted force analysis to further reveal the mechanism for droplet self-propulsion, and found that the nanostructures are critical to providing a large driving force and small resistance force. Theoretical calculation has been used to analyze the maximal self-propulsion displacement on different gradient surfaces with different volumes of droplets. On this basis, we designed several surfaces with arbitrary paths, which achieved directional and long-range transportation of droplet. These results clarify a driving mechanism for droplet self-propulsion on wettability gradient surfaces, and open up new opportunities for long-range and directional droplet transportation in microfluidic system.

  7. Proposition of stair climb of a drop using chemical wettability gradient

    Science.gov (United States)

    Seerha, Prabh P. S.; Kumar, Parmod; Das, Arup K.; Mitra, Sushanta K.

    2017-07-01

    We propose a passive technique for a drop to climb along the staircase textured surface using chemical wettability gradients. The stair structure, droplet configuration, and contact angle gradient are modeled using Lagrangian smoothed particle hydrodynamics. The stair climb efficiency of the droplet is found to be a function of wettability gradient strength. Using analytical balance of actuation and resistive forces across droplets, physical reasons behind stair climbing are established and influencing parameters are identified. Evolution of the droplet shape along with the advancing and the receding contact angles is presented from where instantaneous actuation and hysteresis forces are calculated. Using history of Lagrangian particles, circulation at the foot of stairs and progressing development of the advancing drop front are monitored. Higher efficiency in stair climbing in the case of a bigger sized drop than smaller one is obtained from simulation results and realized from force balance. Difficulty in climbing steeper stairs is also demonstrated to delineate the effect of gravitational pull against the actuation force due to the wettability gradient.

  8. Wettability and Coalescence of Cu Droplets Subjected to Two-Wall Confinement.

    Science.gov (United States)

    Li, Xiongying; Ren, Hongru; Wu, Weikang; Li, Hui; Wang, Long; He, Yezeng; Wang, Junjun; Zhou, Yi

    2015-10-13

    Controlling droplet dynamics via wettability or movement at the nanoscale is a significant goal of nanotechnology. By performing molecular dynamics simulations, we study the wettability and spontaneous coalescence of Cu droplets confined in two carbon walls. We first focus on one drop in the two-wall confinement to reveal confinement effects on wettability and detaching behavior of metallic droplets. Results show that Cu droplets finally display three states: non-detachment, semi-detachment and full detachment, depending on the height of confined space. The contact angle ranges from 125° to 177°, and the contact area radius ranges from 12 to ~80 Å. The moving time of the detached droplet in the full detachment state shows a linear relationship with the height of confined space. Further investigations into two drops subjected to confinement show that the droplets, initially distant from each other, spontaneously coalesce into a larger droplet by detachment. The coalescing time and final position of the merged droplet are precisely controlled by tailoring surface structures of the carbon walls, the height of the confined space or a combination of these approaches. These findings could provide an effective method to control the droplet dynamics by confinement.

  9. A review on the wettability of dental implant surfaces II: Biological and clinical aspects.

    Science.gov (United States)

    Gittens, Rolando A; Scheideler, Lutz; Rupp, Frank; Hyzy, Sharon L; Geis-Gerstorfer, Jürgen; Schwartz, Zvi; Boyan, Barbara D

    2014-07-01

    Dental and orthopedic implants have been under continuous advancement to improve their interactions with bone and ensure a successful outcome for patients. Surface characteristics such as surface topography and surface chemistry can serve as design tools to enhance the biological response around the implant, with in vitro, in vivo and clinical studies confirming their effects. However, the comprehensive design of implants to promote early and long-term osseointegration requires a better understanding of the role of surface wettability and the mechanisms by which it affects the surrounding biological environment. This review provides a general overview of the available information about the contact angle values of experimental and of marketed implant surfaces, some of the techniques used to modify surface wettability of implants, and results from in vitro and clinical studies. We aim to expand the current understanding on the role of wettability of metallic implants at their interface with blood and the biological milieu, as well as with bacteria, and hard and soft tissues. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  10. Morphing and vectoring impacting droplets by means of wettability-engineered surfaces.

    Science.gov (United States)

    Schutzius, Thomas M; Graeber, Gustav; Elsharkawy, Mohamed; Oreluk, James; Megaridis, Constantine M

    2014-11-13

    Driven by its importance in nature and technology, droplet impact on solid surfaces has been studied for decades. To date, research on control of droplet impact outcome has focused on optimizing pre-impact parameters, e.g., droplet size and velocity. Here we follow a different, post-impact, surface engineering approach yielding controlled vectoring and morphing of droplets during and after impact. Surfaces with patterned domains of extreme wettability (high or low) are fabricated and implemented for controlling the impact process during and even after rebound--a previously neglected aspect of impact studies on non-wetting surfaces. For non-rebound cases, droplets can be morphed from spheres to complex shapes--without unwanted loss of liquid. The procedure relies on competition between surface tension and fluid inertial forces, and harnesses the naturally occurring contact-line pinning mechanisms at sharp wettability changes to create viable dry regions in the spread liquid volume. Utilizing the same forces central to morphing, we demonstrate the ability to rebound orthogonally-impacting droplets with an additional non-orthogonal velocity component. We theoretically analyze this capability and derive a We(-.25) dependence of the lateral restitution coefficient. This study offers wettability-engineered surfaces as a new approach to manipulate impacting droplet microvolumes, with ramifications for surface microfluidics and fluid-assisted templating applications.

  11. Reversible wettability conversion of electrodeposited graphene oxide/titania nanocomposite coating: Investigation of surface structures

    Energy Technology Data Exchange (ETDEWEB)

    Naghdi, Samira; Jaleh, Babak, E-mail: bkjaleh@yahoo.com; Shahbazi, Nima

    2016-04-15

    Graphical abstract: - Highlights: • Electrophoretic deposition of Graphene oxide/titania on aluminum surface. • Superhydrophilicity of the GO/TiO{sub 2} coating (WCA ≈ 5°). • Wettability switching of the coating via thermal annealing to superhyrophobic. • The superhydrophobic coating was changed to superhydrophilic due to UV irradiance. • The GO/TiO{sub 2} coating has reversible wettability. - Abstract: Graphene oxide/titania (GO/TiO{sub 2}) nanocomposite have been successfully prepared by a simple method and deposited on the surface of aluminum (Al) by the electrophoretic deposition method. The effect of thermal annealing on wettability of GO/TiO{sub 2} coating has been investigated. According to the obtained results, the water contact angle (WCA) increased with an increase in annealing temperature which may be attributed to the regulation of coating from superhydrophilic (WCA ≈ 5°) to superhydrophobic (WCA ≈ 148°) via thermal annealing. Moreover, the superhydrophobic coating was changed to a superhydrophilic one by using ultraviolet irradiation and this effect was reversible by heat treatment.

  12. Scattering from Rock and Rock Outcrops

    Science.gov (United States)

    2018-01-23

    quantities correspond to values of 0.86 and 18 respectively. SCATTERING FROM ROCKS 3 Figure 2. ( color online) Rough interface results from a glacially abraded...surface in (a) the low-resolution mode, and (b) the high-resolution mode. The glaciers flowed in the negative y direction. The color bar corresponds...to height reference to the surface mean, and the brightness, or black/ white information communicates the surface slope. The dashed box in (a

  13. Rock Equity Holdings, LLC

    Science.gov (United States)

    The EPA is providing notice of an Administrative Penalty Assessment in the form of an Expedited Storm Water Settlement Agreement against Rock Equity Holdings, LLC, for alleged violations at The Cove at Kettlestone/98th Street Reconstruction located at 3015

  14. Eclogite facies rocks

    National Research Council Canada - National Science Library

    Carswell, D. A

    1990-01-01

    ... of eclogite evolution and genesis. The authors present a thorough treatment of the stability relations and geochemistry of these rocks, their intimate association with continental plate collision zones and suture zones...

  15. Pop & rock / Berk Vaher

    Index Scriptorium Estoniae

    Vaher, Berk, 1975-

    2001-01-01

    Uute heliplaatide Redman "Malpractice", Brian Eno & Peter Schwalm "Popstars", Clawfinger "A Whole Lot of Nothing", Dario G "In Full Color", MLTR e. Michael Learns To Rock "Blue Night" lühitutvustused

  16. Rock kinoekraanil / Katrin Rajasaare

    Index Scriptorium Estoniae

    Rajasaare, Katrin

    2008-01-01

    7.-11. juulini kinos Sõprus toimuval filminädalal "Rock On Screen" ekraanile jõudvatest rockmuusikuid portreteerivatest filmidest "Lou Reed's Berlin", "The Future Is Unwritten: Joe Strummer", "Control: Joy Division", "Hurriganes", "Shlaager"

  17. Rock and Soil Rheology

    Science.gov (United States)

    Cristescu, Nicolae; Ene, Horia I.

    The first part of the volume contains theoretical considerations of the physical properties of soils and rocks. Articles on the mechanical and kinematical behavior of rocks as well as mathematical models are the base for the understanding of the physical properties of natural systems. In the second part articles deal with experiments and applications regarding creep deformation of clay, underground cavities, tunnels and deformation of sand and lamistrine sediments.

  18. Parallel Control over Surface Charge and Wettability Using Polyelectrolyte Architecture: Effect on Protein Adsorption and Cell Adhesion.

    Science.gov (United States)

    Guo, Shanshan; Zhu, Xiaoying; Li, Min; Shi, Liya; Ong, June Lay Ting; Jańczewski, Dominik; Neoh, Koon Gee

    2016-11-09

    Surface charge and wettability, the two prominent physical factors governing protein adsorption and cell adhesion, have been extensively investigated in the literature. However, a comparison between these driving forces in terms of their independent and cooperative effects in affecting adhesion is rarely explored on a systematic and quantitative level. Herein, we formulate a protocol that features two-dimensional control over both surface charge and wettability with limited cross-parameter influence. This strategy is implemented by controlling both the polyion charge density in the layer-by-layer (LbL) assembly process and the polyion side-chain chemical structures. The 2D property matrix spans surface isoelectric points ranging from 5 to 9 and water contact angles from 35 to 70°, with other interferential factors (e.g., roughness) eliminated. The interplay between these two surface variables influences protein (bovine serum albumin, lysozyme) adsorption and 3T3 fibroblast cell adhesion. For proteins, we observe the presence of thresholds for surface wettability and electrostatic driving forces necessary to affect adhesion. Beyond these thresholds, the individual effects of electrostatic forces and wettability are observed. For fibroblast, both surface charge and wettability have an effect on its adhesion. The combined effects of positive charge and hydrophilicity lead to the highest cell adhesion, whereas negative charge and hydrophobicity lead to the lowest cell adhesion. Our design strategy can potentially form the basis for studying the distinct behaviors of electrostatic force or wettability driven interfacial phenomena and serve as a reference in future studies assessing protein adsorption and cell adhesion to surfaces with known charge and wettability within the property range studied here.

  19. THE STRUCTURAL FRAMEWORK UNDERLYING THE ...

    African Journals Online (AJOL)

    The structural framework underlying the metamorphic aspect of the various rocks in Kazaure schist belt (KZSB) was studied. The KZSB consists of metasediments and metavolcanics that are bounded by Older Granites and gneisses. Detailed structural analysis of the Kazaure schist belt revealed the occurrence of structures ...

  20. Fluid-Rock Characterization and Interactions in NMR Well Logging

    Energy Technology Data Exchange (ETDEWEB)

    Hirasaki, George J.; Mohanty, Kishore, K.

    2001-07-13

    The objective of this project is to characterize the fluid properties and fluid-rock interactions that are needed for formation evaluation by NMR well logging. This is the first annual progress report submitted to the DOE. It reports on the work completed during the reporting period even if it may have started before this period. This project is a partnership between Professor George J. Hirasaki at Rice University and Professor Kishore Mohanty at University of Houston. In addition to the DOE, this project is supported by a consortium of oil companies and service companies. The fluid properties characterization has emphasized the departure of live oils from correlations based on dead oils. Also, asphaltic components can result in a difference between the T1 and T2 relaxation time distributions as well as reduce the hydrogen index. The fluid rock characterizations that are reported here are the effects of wettability and internal magnetic field gradients. A pore reconstruction method ha s been developed to recreate three-dimensional porous media from two-dimensional images that reproduce some of their key statistical properties. A Monte Carlo simulation technique has been developed to calculate the magnetization decay in fluid saturated porous media given their pore structure.

  1. Improving wettability of photo-resistive film surface with plasma surface modification for coplanar copper pillar plating of IC substrates

    Energy Technology Data Exchange (ETDEWEB)

    Xiang, Jing; Wang, Chong; Chen, Yuanming; Wang, Shouxu; Hong, Yan; Zhang, Huaiwu [State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054 (China); Gong, Lijun [Research and Development Department, Guangzhou Fastprint Circuit Tech Co., Ltd., Guangzhou 510663 (China); He, Wei, E-mail: heweiz@uestc.edu.cn [State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054 (China); Research and Development Department, Guangdong Guanghua Sci-Tech Co., Ltd., Shantou 515000 (China)

    2017-07-31

    Highlights: • Air atmosphere plasmacould generatehydrophilic groups of photo-resistive film. • Better wettability of photo-resistive filmled tohigher plating uniformity of copper pillars. • New flow isreduced cost, simplified process and elevated productivity. - Abstract: The wettability of the photo-resistive film (PF) surfaces undergoing different pretreatments including the O{sub 2}−CF{sub 4} low-pressure plasma (OCLP) and air plasma (AP), is investigated by water contact angle measurement instrument (WCAMI) before the bottom-up copper pillar plating. Chemical groups analysis performed by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectra (XPS) shows that after the OCLP and wash treatment, the wettability of PF surface is attenuated, because embedded fluorine and decreased oxygen content both enhance hydrophobicity. Compared with OCLP treatment, the PF surface treatment by non-toxic air plasma displays features of C−O, O−C=O, C=O and −NO{sub 2} by AIR-FTIR and XPS, and a promoted wettability by WCAM. Under the identical electroplating condition, the surface with a better wettability allows electrolyte to spontaneously soak all the places of vias, resulting in improved copper pillar uniformity. Statistical analysis of metallographic data shows that more coplanar and flat copper pillars are achieved with the PF treatment of air plasma. Such modified copper-pillar-plating technology meets the requirement of accurate impedance, the high density interconnection for IC substrates.

  2. The Effect of Hydrofluoric Acid Etching Duration on the Surface Micromorphology, Roughness, and Wettability of Dental Ceramics

    Directory of Open Access Journals (Sweden)

    Ravikumar Ramakrishnaiah

    2016-05-01

    Full Text Available The current laboratory study is evaluating the effect of hydrofluoric acid etching duration on the surface characteristics of five silica-based glass ceramics. Changes in the pore pattern, crystal structure, roughness, and wettability were compared and evaluated. Seventy-five rectangularly shaped specimens were cut from each material (IPS e-max™, Dentsply Celtra™, Vita Suprinity™, Vita mark II™, and Vita Suprinity FC™; the sectioned samples were finished, polished, and ultrasonically cleaned. Specimens were randomly assigned into study groups: control (no etching and four experimental groups (20, 40, 80 and 160 s of etching. The etched surfaces’ microstructure including crystal structure, pore pattern, pore depth, and pore width was studied under a scanning electron microscope, and the surface roughness and wettability were analyzed using a non-contact surface profilometer and a contact angle measuring device, respectively. The results were statistically analyzed using one-way analysis of variance (ANOVA and the post hoc Tukey’s test. The results showed a significant change in the pore number, pore pattern, crystal structure, surface roughness, and wettability with increased etching duration. Etching for a short time resulted in small pores, and etching for longer times resulted in wider, irregular grooves. A significant increase in the surface roughness and wettability was observed with an increase in the etching duration. The findings also suggested a strong association between the surface roughness and wettability.

  3. An exploration of self-efficacy as a motivation for rock climbing and its impact on frequency of climbs

    Science.gov (United States)

    Edwin Gomez; Eddie Hill; Amy Ackerman

    2008-01-01

    This study utilizes the theoretical framework of self-efficacy to explore the role it plays in rock climbing. Data were gathered from on-site self-administered surveys to rock-climbers in three different locations (N=72). A conceptual model was developed to consider the relationship between selfefficacy and frequency of rock climbing. The initial factor of self-...

  4. Session: Hard Rock Penetration

    Energy Technology Data Exchange (ETDEWEB)

    Tennyson, George P. Jr.; Dunn, James C.; Drumheller, Douglas S.; Glowka, David A.; Lysne, Peter

    1992-01-01

    This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of five presentations: ''Hard Rock Penetration - Summary'' by George P. Tennyson, Jr.; ''Overview - Hard Rock Penetration'' by James C. Dunn; ''An Overview of Acoustic Telemetry'' by Douglas S. Drumheller; ''Lost Circulation Technology Development Status'' by David A. Glowka; ''Downhole Memory-Logging Tools'' by Peter Lysne.

  5. Layered Rocks in Ritchey

    Science.gov (United States)

    2004-01-01

    14 May 2004 This March 2004 Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows light- and dark-toned layered rock outcrops on the floor of Ritchey Crater, located near 28.9oS, 50.8oW. Some or all of these rocks may be sedimentary in origin. Erosion has left a couple of buttes standing on a more erosion-resistant plain. This picture covers an area approximately 3 km (1.9 mi) across and is illuminated by sunlight from the upper left.

  6. Studies of electrical properties of low-resistivity sandstones based on digital rock technology

    Science.gov (United States)

    Yan, Weichao; Sun, Jianmeng; Zhang, Jinyan; Yuan, Weiguo; Zhang, Li; Cui, Likai; Dong, Huaimin

    2018-02-01

    Electrical properties are important parameters to quantitatively calculate water saturation in oil and gas reservoirs by well logging interpretation. It is usual that oil layers show high resistivity responses, while water layers show low-resistivity responses. However, there are low-resistivity oil zones that exist in many oilfields around the world, leading to difficulties for reservoir evaluation. In our research, we used digital rock technology to study different internal and external factors to account for low rock resistivity responses in oil layers. We first constructed three-dimensional digital rock models with five components based on micro-computed tomography technology and x-ray diffraction experimental results, and then oil and water distributions in pores were determined by the pore morphology method. When the resistivity of each component was assigned, rock resistivities were calculated by using the finite element method. We collected 20 sandstone samples to prove the effectiveness of our numerical simulation methods. Based on the control variate method, we studied the effects of different factors on the resistivity indexes and rock resistivities. After sensitivity analyses, we found the main factors which caused low rock resistivities in oil layers. For unfractured rocks, influential factors arranged in descending order of importance were porosity, clay content, temperature, water salinity, heavy mineral, clay type and wettability. In addition, we found that the resistivity index could not provide enough information to identify a low-resistivity oil zone by using laboratory rock–electric experimental results. These results can not only expand our understandings of the electrical properties of low-resistivity rocks from oil layers, but also help identify low-resistivity oil zones better.

  7. Droplet spreading and permeating on the hybrid-wettability porous substrates: a lattice Boltzmann method study

    Directory of Open Access Journals (Sweden)

    Ge Wen-Kai

    2016-01-01

    Full Text Available The spreading and permeation of droplets on porous substrates is a fundamental process in a variety of applications, such as coating, dyeing, and printing. The spreading and permeating usually occur synchronously but play different roles in the practical applications. The mechanisms of the competition between spreading and permeation is significant but still unclear. A lattice Boltzmann method is used to study the spreading and permeation of droplets on hybrid-wettability porous substrates, with different wettability on the surface and the inside pores. The competition between the spreading and the permeation processes is studied in this work from the effects of the substrate and the fluid properties, including the substrate wettability, the porous parameters, as well as the fluid surface tension and viscosity. The results show that increasing the surfacewettability and the porosity contact angle both inhibit the spreading and the permeation processes. When the inside porosity contact angle is larger than 90° (hydrophobic, the permeation process does not occur. The droplets suspend on substrates with Cassie state. The droplets are more easily to permeate into substrates with a small inside porosity contact angle (hydrophilic, as well as large pore sizes. Otherwise, the droplets are more easily to spread on substrate surfaces with small surface contact angle (hydrophilic and smaller pore sizes. The competition between droplet spreading and permeation is also related to the fluid properties. The permeation process is enhanced by increasing of surface tension, leading to a smaller droplet lifetime. The goals of this study are to provide methods to manipulate the spreading and permeation separately, which are of practical interest in many industrial applications.

  8. Seasonal variability of interception and water wettability of common oak leaves

    Directory of Open Access Journals (Sweden)

    Anna Klamerus-Iwan

    2017-07-01

    Full Text Available Wettability of leaves and the resulting amount of interception loss of tree crowns is an important component of the atmosphere-tree stand-soil system balance. In the study, we hypothesized that changes occurring in leaves during the vegetation period can significantly affect the amount of rainwater retained by plants and wettability of leaves which is expressed by the contact angle between drops and leaves. We evaluated the hypothesis based on measurement series, which combined direct spraying of leaves with water at different stages of development at a constant temperature with observations made with an electron scanner which was used to determine changes occurring within a leaf, while the photographic method was used to analyze the contact angle of drops. The study involved common oak (Quercus robur. Samples of twigs derived from this species were collected in the area of Przedbórz (Poland forest district, in particular from the trees with well-developed crowns. Twigs were collected from 10 trees of similar age (35–40 years. The resulting database contained experimental data on changes of raindrop adhesion on oak leaves throughout the growing season. The internal contact angle of drops was within the range of 150° on the upper side of the leaf and 160° on the underside in May, up to 15° and 35° in November on the upper and underside of the leaves. Loss of interception was established at 6% at the beginning of the growing season up to 22% in autumn. It was concluded that the wettability and the level of interception increases in line with the age of a leaf.

  9. Dominant Albumin-Surface Interactions under Independent Control of Surface Charge and Wettability.

    Science.gov (United States)

    Guo, Shanshan; Pranantyo, Dicky; Kang, En-Tang; Loh, Xian Jun; Zhu, Xiaoying; Jańczewski, Dominik; Neoh, Koon Gee

    2018-02-06

    Understanding protein adsorption behaviors on solid surfaces constitutes an important step toward development of efficacious and biocompatible medical devices. Both surface charge and wettability have been shown to influence protein adsorption attributes, including kinetics, quantities, deformation, and reversibility. However, determining the dominant interaction in these surface-induced phenomena is challenging because of the complexity of inter-related mechanisms at the liquid/solid interface. Herein, we reveal the dominant interfacial forces in these essential protein adsorption attributes under the influence of a combination of surface charge and wettability, using quartz crystal microbalance with dissipation monitoring and atomic force microscopy-based force spectroscopy on a series of model surfaces. These surfaces were fabricated via layer-by-layer assembly, which allowed two-dimensional control of surface charge and wettability with minimal cross-parameter dependency. We focused on a soft globular protein, bovine serum albumin (BSA), which is prone to conformational changes during adsorption. The information obtained from the two techniques shows that both surface charge and hydrophobicity can increase the protein-surface interaction forces and the adsorbed amount. However, surface hydrophobicity triggered a greater extent of deformation in the adsorbed BSA molecules, leading to more dehydration, spreading, and resistance to elution by ionic strength changes regardless of the surface charge. The role played by the surface charge in the adsorbed protein conformation and extent of desorption induced by changes in the ionic strength is secondary to that of surface hydrophobicity. These findings advance the understanding of how surface chemistry and properties can be tailored for directing protein-substrate interactions.

  10. Fault Rock Variation as a Function of Host Rock Lithology

    Science.gov (United States)

    Fagereng, A.; Diener, J.

    2013-12-01

    Fault rocks contain an integrated record of the slip history of a fault, and thereby reflect the deformation processes associated with fault slip. Within the Aus Granulite Terrane, Namibia, a number of Jurassic to Cretaceous age strike-slip faults cross-cut Precambrian high grade metamorphic rocks. These strike-slip faults were active at subgreenschist conditions and occur in a variety of host rock lithologies. Where the host rock contains significant amounts of hydrous minerals, representing granulites that have undergone retrogressive metamorphism, the fault rock is dominated by hydrothermal breccias. In anhydrous, foliated rocks interlayered with minor layers containing hydrous phyllosilicates, the fault rock is a cataclasite partially cemented by jasper and quartz. Where the host rock is an isotropic granitic rock the fault rock is predominantly a fine grained black fault rock. Cataclasites and breccias show evidence for multiple deformation events, whereas the fine grained black fault rocks appear to only record a single slip increment. The strike-slip faults observed all formed in the same general orientation and at a similar time, and it is unlikely that regional stress, strain rate, pressure and temperature varied between the different faults. We therefore conclude that the type of fault rock here depended on the host rock lithology, and that lithology alone accounts for why some faults developed a hydrothermal breccia, some cataclasite, and some a fine grained black fault rock. Consequently, based on the assumption that fault rocks reflect specific slip styles, lithology was also the main control on different fault slip styles in this area at the time of strike-slip fault activity. Whereas fine grained black fault rock is inferred to represent high stress events, hydrothermal breccia is rather related to events involving fluid pressure in excess of the least stress. Jasper-bearing cataclasites may represent faults that experienced dynamic weakening as seen

  11. Deposit buildup on prosthetic eye material (in vitro and its effect on surface wettability

    Directory of Open Access Journals (Sweden)

    Pine KR

    2013-02-01

    Full Text Available Keith Raymond Pine,1 Brian Sloan,2 KyuYeon Ivy Han,1 Simon Swift,3 Robert John Jacobs11Department of Optometry and Vision Science, New Zealand National Eye Centre, The University of Auckland, Auckland, New Zealand; 2New Zealand National Eye Centre, The University of Auckland, Auckland, New Zealand; 3Department of Molecular Medicine and Pathology, School of Medical Sciences, The University of Auckland, Auckland, New ZealandBackground: The aim of this in-vitro study was to investigate the effect of different polishing standards on prosthetic eye material (poly(methyl methacrylate [PMMA] on surface wettability and the rate of protein and lipid buildup.Methods: Sample disks (12 mm diameter × 1 mm thickness of PMMA were polished to three different standards of surface finish: low, normal, and optical quality contact lens standard. The sample disks were incubated in a protein-rich artificial tear solution (ATS for the following periods of time: 1 second, 30 minutes, 1 hour, 4 hours, 24 hours, and 14 days. Surface wettability was measured with a goniometer before and after protein deposits were removed. One-way analysis of variance and paired-samples t-test were used for the statistical analysis.Results: Between 13.64 and 62.88 µg of protein adhered to the sample disks immediately upon immersion in ATS. Sample disks with the highest polish attracted less protein deposits. The sample disks polished to optical quality contact lens standard were more wettable than those less highly polished, and wettability significantly decreased following removal of protein deposits. The addition of lipids to protein-only ATS made no difference to the amount of protein deposited on the sample disks for any of the standards of surface polish tested.Conclusion: The findings are consistent with the results of the in-vivo investigation reported previously by the authors. Our view that the minimum standard of polish for prosthetic eyes should be optical quality contact

  12. Wettability in the liquid Cu-Ag alloy – fireproof material – gas phase system

    Directory of Open Access Journals (Sweden)

    G. Siwiec

    2013-07-01

    Full Text Available In the present paper, results of wettability studies on the liquid metal – fireproof material – gas phase system using copper and Cu-Ag alloys as well as typical fireproof materials, i.e. aluminium oxide, magnesium oxide and graphite, are presented. Contact angle measurements were conducted at 1 373–1 573 K by means of a high-temperature microscope coupled with a camera and a computer equipped with a program for recording and analysing images. For the measurements, the sessile drop method was used.

  13. Wettability of water droplet on misoriented graphene bilayer sructure: A molecular dynamics study

    Directory of Open Access Journals (Sweden)

    Qingchang Liu

    2015-06-01

    Full Text Available Graphene continues to attract growing attention with its exceptional physical and mechanical properties, and more than one layer graphene structure with an orientation mismatch is often involved in practice. Using molecular dynamics (MD simulations, we report the wettability of water droplet on a misoriented graphene bilayer structure. The contact angle of water droplet will change with the interlayer orientation of bilayer graphene structure, and reaches a maximum of 97.97 ± 1.15° at orientation mismatch of 40°. Comprehensive understanding on density profile and hydrogen bonding of water molecules and water-carbon interactive energy is explored to reveal the molecular mechanism.

  14. Wettability and bond strength between leucite-reinforced dental porcelains and Co-Cr alloy.

    Science.gov (United States)

    Yao, Lan; Peng, Cheng; Wu, Jianqing

    2013-12-01

    A series of methods has been used to evaluate metal ceramic bond strength. However, little attention has been paid to the wettability and interfacial reactions of dental porcelain/alloy systems, which may affect the bond strength of metal ceramic restorations. The purpose of this study was to understand the wetting and spreading behaviors, the interfacial reactions, and the bonding mechanism of ceramic to metal with TiO2 and MoO3 added to the dental porcelain. Two leucite-reinforced dental porcelains were used in the study. Twelve Co-Cr alloy sheets (15 × 10 × 2 mm) divided into 2 groups were used to evaluate the wetting process, and 12 Co-Cr alloy sheets (25 × 3 × 0.5 mm) (Bego) divided into 2 groups were used for the 3-point bond strength test. The wetting process of the porcelain/alloy systems was observed in situ with a Tommi optical dimension measurement system using a modified sessile drop method. The reaction products of the interfacial region were determined by Raman spectra analyses. Metal ceramic specimens were tested in 3-point bending at a crosshead speed of 1.5 mm/min according to ISO 9693 requirements, and the results were statistically analyzed with 1-way ANOVA (α=.05). The addition of TiO2 and MoO3 in the dental porcelain improved the wettability of the dental porcelain/Co-Cr alloy system. The bond strength of the porcelain modified with TiO2 and MoO3 was 43 ±2 MPa and that of the unmodified porcelain was 38 ±3 MPa. The fracture of the 2 metal ceramic systems occurred near the porcelain layer. The application of TiO2 and MoO3 to the leucite-reinforced porcelain can improve the wettability of porcelain on alloy. Porcelain/alloy wettability can be used as a guide to improve the bonding property between dental porcelain and alloys. Copyright © 2013 Editorial Council for the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

  15. STUDIES ON WETTABILITY OF STAINLESS STEEL 316L POWDER IN LASER MELTING PROCESS

    Directory of Open Access Journals (Sweden)

    KURIAN ANTONY

    2014-10-01

    Full Text Available Laser sintering is one of the techniques used in additive manufacturing processes. The main objective of the work is to study the effects of process parameters on wetting phenomenon and interfacial energy during laser melting of stainless steel powder. This paper reports wetting of laser melted powder particles and its use for the determination of surface energy of stainless steel powder under laser beam exposure. Process parameters such as laser power, scan speed and beam diameter are considered for study. This study also identifies the process parameters for better wettability which produces smooth surfaces.

  16. Fluids in metamorphic rocks

    NARCIS (Netherlands)

    Touret, J.L.R.

    2001-01-01

    Basic principles for the study of fluid inclusions in metamorphic rocks are reviewed and illustrated. A major problem relates to the number of inclusions, possibly formed on a wide range of P-T conditions, having also suffered, in most cases, extensive changes after initial trapping. The

  17. Rock support design

    Energy Technology Data Exchange (ETDEWEB)

    Vandewalle, M. [N.V. Bekaert (Belgium)

    1999-02-01

    Steel fibre imparts to concrete and shotcrete a high degree of ductibility which not only allow the linings to absorb rock movement but also increases its bearing capacity by a redistribution of the loads. The article discusses the variety of uses of shotcrete for support of underground excavations, mainly for support of permanent mine openings such as ramps, haulages, shaft stations and crusher chambers.

  18. The River Rock School.

    Science.gov (United States)

    Gereaux, Teresa Thomas

    1999-01-01

    In the early 1920s, the small Appalachian community of Damascus, Virginia, used private subscriptions and volunteer labor to build a 15-classroom school made of rocks from a nearby river and chestnut wood from nearby forests. The school building's history, uses for various community activities, and current condition are described. (SV)

  19. Reducing Rock Climbing Risks.

    Science.gov (United States)

    Attarian, Aram

    1998-01-01

    Provides checklists that can be used as risk-management tools to evaluate rock-climbing programs: developing goals, policies, and procedures; inspecting the climbing environment; maintaining and inspecting equipment; protecting participants; and managing staff (hiring, training, retraining, and evaluating) and campers (experience level, needs, and…

  20. Umhlanga Rocks coastal defense

    NARCIS (Netherlands)

    De Jong, L.; De Jong, B.; Ivanova, M.; Gerritse, A.; Rietberg, D.; Dorrepaal, S.

    2014-01-01

    The eThekwini coastline is a vulnerable coastline subject to chronic erosion and damage due to sea level rise. In 2007 a severe storm caused major physical and economic damage along the coastline, proving the need for action. Umhlanga Rocks is a densely populated premium holiday destination on the

  1. Teaching the Rock Cycle with Ease.

    Science.gov (United States)

    Bereki, Debra

    2000-01-01

    Describes a hands-on lesson for teaching high school students the concept of the rock cycle using sedimentary, metamorphic, and igneous rocks. Students use a rock cycle diagram to identify pairs of rocks. From the rock cycle, students explain on paper how their first rock became the second rock and vice versa. (PVD)

  2. Reversible wettability of electron-beam deposited indium-tin-oxide driven by ns-UV irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Persano, Luana [NNL, National Nanotechnology Laboratory of CNR-Istituto Nanoscienze, Universita del Salento, via Arnesano, I-73100 Lecce (Italy); Center for Biomolecular Nanotechnologies UNILE, Istituto Italiano di Tecnologia, Via Barsanti, I-73010 Arnesano-LE (Italy); Del Carro, Pompilio [NNL, National Nanotechnology Laboratory of CNR-Istituto Nanoscienze, Universita del Salento, via Arnesano, I-73100 Lecce (Italy); Pisignano, Dario [NNL, National Nanotechnology Laboratory of CNR-Istituto Nanoscienze, Universita del Salento, via Arnesano, I-73100 Lecce (Italy); Center for Biomolecular Nanotechnologies UNILE, Istituto Italiano di Tecnologia, Via Barsanti, I-73010 Arnesano-LE (Italy); Dipartimento di Matematica e Fisica ' ' Ennio De Giorgi' ' , Universita del Salento, via Arnesano, I-73100 Lecce (Italy)

    2012-04-09

    Indium tin oxide (ITO) is one of the most widely used semiconductor oxides in the field of organic optoelectronics, especially for the realization of anode contacts. Here the authors report on the control of the wettability properties of ITO films deposited by reactive electron beam deposition and irradiated by means of nanosecond-pulsed UV irradiation. The enhancement of the surface water wettability, with a reduction of the water contact angle larger than 50 deg., is achieved by few tens of seconds of irradiation. The analyzed photo-induced wettability change is fully reversible in agreement with a surface-defect model, and it can be exploited to realize optically transparent, conductive surfaces with controllable wetting properties for sensors and microfluidic circuits.

  3. A study of metal-ceramic wettability in SiC-Al using dynamic melt infiltration of SiC

    Science.gov (United States)

    Asthana, R.; Rohatgi, P. K.

    1993-01-01

    Pressure-assisted infiltration with a 2014 Al alloy of plain and Cu-coated single crystal platelets of alpha silicon carbide was used to study particulate wettability under dynamic conditions relevant to pressure casting of metal-matrix composites. The total penetration length of infiltrant metal in porous compacts was measured at the conclusion of solidification as a function of pressure, infiltration time, and SiC size for both plain and Cu-coated SiC. The experimental data were analyzed to obtain a threshold pressure for the effect of melt intrusion through SiC compacts. The threshold pressure was taken either directly as a measure of wettability or converted to an effective wetting angle using the Young-Laplace capillary equation. Cu coating resulted in partial but beneficial improvements in wettability as a result of its dissolution in the melt, compared to uncoated SiC.

  4. Three-phase flow in heterogeneous wettability porous media; Deplacements triphasiques en milieux poreux de mouillabilite heterogene

    Energy Technology Data Exchange (ETDEWEB)

    Jaffrennou-Laroche, C.

    1998-11-26

    Better understanding and modelling of three-phase flow through porous media is of great interest, especially for improved oil recovery methods such as gas injection processes. Early theoretical and experimental studies have already demonstrated that the wettability characteristics of the solid surface and the spreading characteristics of the fluid system hold the key roles. This observation is confirmed by our theoretical results using DLP theory on the stability and the thickness of static oil films. In most of the works related to three-phase flow processes, homogeneous wettability is assumed. There exist only a few studies demonstrating the tremendous impact of the wettability heterogeneities on gas injection. The objective of the present work is twofold: to demonstrate the effect of small scale wettability heterogeneities on gas injection efficiency, and to develop a tool to predict this impact for various patterns and spatial distributions. To this end an experimental investigation in transparent glass micro-models is performed and a theoretical simulator is developed. Secondary and tertiary gas injections are performed for different heterogeneity patterns obtained by selective silane grafting. Displacement sequences are video-recorded and fluid saturations are determined by image analysis. Visualization of the displacement mechanisms provides the network model with the basic rules for water/oil and water/oil/gas motion. In water/oil displacement, drainage and imbibition occur according to the local wettability. Three-phase displacement is dominated by drainage mechanisms. The simulator allows the flow of oil through wetting films in the oil-wet regions and through spreading films on water in the water-wet regions. The effect of the wettability heterogeneities on: displacement mechanisms, sweep efficiency, and fluid distribution in three-phase gas injection is clearly demonstrated and successfully described by the network simulator. (author) 175 refs.

  5. Nanosecond laser texturing of uniformly and non-uniformly wettable micro structured metal surfaces for enhanced boiling heat transfer

    Energy Technology Data Exchange (ETDEWEB)

    Zupančič, Matevž, E-mail: matevz.zupancic@fs.uni-lj.si; Može, Matic; Gregorčič, Peter; Golobič, Iztok

    2017-03-31

    Highlights: • Surfaces with periodically changed wettability were produced by a ns marking laser. • Heat transfer was investigated on uniformly and non-uniformly wettable surfaces. • Microporous surfaces with non-uniform wettability enhance boiling heat transfer. • The most bubble nucleations were observed in the vicinity of the microcavities. • Results agree with the predictions of the nucleation criteria. - Abstract: Microstructured uniformly and non-uniformly wettable surfaces were created on 25-μm-thin stainless steel foils by laser texturing using a marking nanosecond Nd:YAG laser (λ = 1064 nm) and utilizing various laser fluences and scan line separations. High-speed photography and high-speed IR thermography were used to investigate nucleate boiling heat transfer on the microstructured surfaces. The most pronounced results were obtained on a surface with non-uniform microstructure and non-uniform wettability. The obtained results show up to a 110% higher heat transfer coefficients and 20–40 times higher nucleation site densities compared to the untextured surface. We show that the number of active nucleation sites is significantly increased in the vicinity of microcavities that appeared in areas with the smallest (10 μm) scan line separation. Furthermore, this confirms the predictions of nucleation criteria and proves that straightforward, cost-effective nanosecond laser texturing allows the production of cavities with diameters of up to a few micrometers and surfaces with non-uniform wettability. Additionally, this opens up important possibilities for a more deterministic control over the complex boiling process.

  6. Factors affecting the wettability of different surface materials with vegetable oil at high temperatures and its relation to cleanability

    DEFF Research Database (Denmark)

    Ashokkumar, Saranya; Adler-Nissen, Jens; Møller, Per

    2012-01-01

    The main aim of the work was to investigate the wettability of different surface materials with vegetable oil (olive oil) over the temperature range of 25–200°C to understand the differences in cleanability of different surfaces exposed to high temperatures in food processes. The different surface...... different levels of roughness. The cosine of the contact angle of olive oil on different surface materials rises linearly with increasing temperature. Among the materials analyzed, polymers (PTFE, silicone) gave the lowest cosθ values. Studies of the effect of roughness and surface flaws on wettability...

  7. Improvement of wettability and absorbancy of textile using atmospheric pressure dielectric barrier discharge

    Science.gov (United States)

    Ghimire, Bhagirath; Subedi, Deepak Prasad; Khanal, Raju

    2017-08-01

    In this study, cotton textile samples, commonly used in making quilt covers were subjected to atmospheric pressure dielectric barrier discharge treatment to study their surface wettability and absorbancy. Samples were treated in the discharge using a rotatory mechanism and the effects of plasma treatment were examined by contact angle measurement and weight measurement. Air plasma treatment was successful in incorporating hydrophilic functional groups on the textile surface due to which wettability as well as absorbancy immediately after the treatment were highly improved. Effects of plasma treatment started to appear only after 20 cycles (9 mins) and got saturated after 24 cycles (10.8 mins) of treatment. The contact angle reduced from 137 ° (untreated sample) to a value less than 30 ° while absorbancy increased by more than two times as compared to untreated sample. Also, the aging behavior of the plasma treated samples were studied for about a week after plasma treatment. It was observed that the induced oxygen containing groups re-oriented into the bulk of the material during their storage in the environment due to which initial properties of the samples recovered gradually. Our results indicate that low temperature plasma can be successfully applied to modify the properties of textiles and textile industries could utilize this by standardization.

  8. Selective separation of oil and water with special wettability mesh membranes

    KAUST Repository

    Liu, Defei

    2017-02-24

    Due to the different interfacial effects of oil and water, utilizing the special wettability of solid surfaces to design an oil and water separation process has been demonstrated to be an effective approach for oil/water separation. In this report, a simple process has been developed to fabricate special surface wettability mesh membranes. The carbon nanoparticles with diameters of 10 nm were first coated onto the surface of steel wires based on a candle soot coating process. These templates of carbon nanoparticles were then coated with a more stable layer of silica (SiO2) particles via a facile chemical vapor deposition route. After being modified by two separate methods, a superhydrophobic/superoleophilic membrane was obtained by the use of 1H,1H,2H,2H-perfluorooctyltrichlorosilane (PFOTS) and a oleophobic/superhydrophilic membrane was obtained by using poly(diallyldimethylammonium-perfluorooctanoate) (PDDA–PFO). Separation experiments show that these superhydrophobic/superoleophilic or oleophobic/superhydrophilic mesh membranes can be used to selectively separate oil/water with a high flux of more than 930 L m−2 h−1 and a collecting efficiency of over 97%. Furthermore, the repetitions of the separation experiments demonstrate that these superhydrophobic/superoleophilic or oleophobic/superhydrophilic mesh membranes are durable, stable and reusable, making them encouraging candidates for practical oil-polluted water treatment.

  9. Surface-Wettability Patterning for Distributing High-Momentum Water Jets on Porous Polymeric Substrates.

    Science.gov (United States)

    Sen, Uddalok; Chatterjee, Souvick; Sinha Mahapatra, Pallab; Ganguly, Ranjan; Dodge, Richard; Yu, Lisha; Megaridis, Constantine M

    2018-02-07

    Liquid jet impingement on porous materials is particularly important in many applications of heat transfer, filtration, or in incontinence products. Generally, it is desired that the liquid not penetrate the substrate at or near the point of jet impact, but rather be distributed over a wider area before reaching the back side. A facile wettability-patterning technique is presented, whereby a water jet impinging orthogonally on a wettability-patterned nonwoven substrate is distributed on the top surface and through the porous matrix, and ultimately dispensed from prespecified points underneath the sample. A systematic approach is adopted to identify the optimum design that allows for a uniform distribution of the liquid on horizontally mounted substrates of ∼50 cm 2 area, with minimal or no spilling over the sample edges at jet flow rates exceeding 1 L/min. The effect of the location of jet impingement on liquid distribution is also studied, and the design is observed to perform well even under offset jet impact conditions.

  10. Wettability, polarity, and water absorption of holm oak leaves: effect of leaf side and age.

    Science.gov (United States)

    Fernández, Victoria; Sancho-Knapik, Domingo; Guzmán, Paula; Peguero-Pina, José Javier; Gil, Luis; Karabourniotis, George; Khayet, Mohamed; Fasseas, Costas; Heredia-Guerrero, José Alejandro; Heredia, Antonio; Gil-Pelegrín, Eustaquio

    2014-09-01

    Plant trichomes play important protective functions and may have a major influence on leaf surface wettability. With the aim of gaining insight into trichome structure, composition, and function in relation to water-plant surface interactions, we analyzed the adaxial and abaxial leaf surface of holm oak (Quercus ilex) as a model. By measuring the leaf water potential 24 h after the deposition of water drops onto abaxial and adaxial surfaces, evidence for water penetration through the upper leaf side was gained in young and mature leaves. The structure and chemical composition of the abaxial (always present) and adaxial (occurring only in young leaves) trichomes were analyzed by various microscopic and analytical procedures. The adaxial surfaces were wettable and had a high degree of water drop adhesion in contrast to the highly unwettable and water-repellent abaxial holm oak leaf sides. The surface free energy and solubility parameter decreased with leaf age, with higher values determined for the adaxial sides. All holm oak leaf trichomes were covered with a cuticle. The abaxial trichomes were composed of 8% soluble waxes, 49% cutin, and 43% polysaccharides. For the adaxial side, it is concluded that trichomes and the scars after trichome shedding contribute to water uptake, while the abaxial leaf side is highly hydrophobic due to its high degree of pubescence and different trichome structure, composition, and density. Results are interpreted in terms of water-plant surface interactions, plant surface physical chemistry, and plant ecophysiology. © 2014 American Society of Plant Biologists. All Rights Reserved.

  11. Enhanced adhesion of osteoblastic cells on polystyrene films by independent control of surface topography and wettability

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Seung Yun [National Creative Research Center for Block Copolymer Self-Assembly, Departments of Environmental Science and Engineering and Chemical Engineering, Pohang University of Science and Technology, Pohang, 790-784 (Korea, Republic of); Kim, Eung-Sam [School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, 790-784 (Korea, Republic of); Jeon, Gumhye [National Creative Research Center for Block Copolymer Self-Assembly, Departments of Environmental Science and Engineering and Chemical Engineering, Pohang University of Science and Technology, Pohang, 790-784 (Korea, Republic of); Choi, Kwan Yong, E-mail: kchoi@postech.ac.kr [School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, 790-784 (Korea, Republic of); Department of Life Science, Division of Molecular and Life Science, Pohang University of Science and Technology, Pohang, 790-784 (Korea, Republic of); Kim, Jin Kon, E-mail: jkkim@postech.ac.kr [National Creative Research Center for Block Copolymer Self-Assembly, Departments of Environmental Science and Engineering and Chemical Engineering, Pohang University of Science and Technology, Pohang, 790-784 (Korea, Republic of)

    2013-04-01

    We independently controlled surface topography and wettability of polystyrene (PS) films by CF{sub 4} and oxygen plasma treatments, respectively, to evaluate the adhesion and proliferation of human fetal osteoblastic (hFOB) cells on the films. Among the CF{sub 4} plasma-treated PS films with the average surface roughness ranging from 0.9 to 70 nm, the highest adhesion of hFOB cells was observed on a PS film with roughness of ∼ 11 nm. When this film was additionally treated by oxygen plasma to provide a hydrophilic surface with a contact angle less than 10°, the proliferation of bone-forming cell was further enhanced. Thus, the plasma-based independent modification of PS film into an optimum nanotexture for human osteoblast cells could be appplied to materials used in bone tissue engineering. Highlights: ► New approach based on plasma treatment to independently control the surface topography and wettability ► The adhesion of human fetal osteoblast (hFOB) was enhanced on a surface with an average roughness of ∼ 11 nm. ► The adhesion and proliferation of hFOB was maximized when nanotextured surface became highly hydrophilic.

  12. Water wettability and zeta-potential of polystyrene surface modified by Ne or Na implantation

    Energy Technology Data Exchange (ETDEWEB)

    Nakao, Aiko; Suzuki, Yoshiaki; Iwaki, Masaya [Inst. of Physical and Chemical Research, Wako, Saitama (Japan). Div. of Surface Characterization

    1998-01-15

    A study has been made of the modification of the wettability and the surface potential of polystyrene by ion bombardment and implantation. Substrates used were polystyrene (PS) dishes. Ne bombardment and Na ion implantation were performed at energies of 50 and 150 keV with fluences between 1 {times} 10{sup 14} to 1 {times} 10{sup 17} ions/cm{sup 2}. The surface potential was examined by measurements of {zeta}-potential and the wettability was examined by the contact angle of water. The contact angle of water and the {zeta}-potential are found to change, depending on ion species and fluences. Two kinds of relationships between the contact angle of water and the {zeta}-potential are found, classified by region A and region B. From XPS results, region A means that PS surfaces modified by radiation effects of Ne-bombardment or Na-implantation have new functional groups and amorphous carbon. In region B, Na implanted PS surfaces with a high fluence show not only new functional groups and amorphous carbon but also Na atoms with chemical bonding states.

  13. Development of a freeze-dried fungal wettable powder preparation able to biodegrade chlorpyrifos on vegetables.

    Directory of Open Access Journals (Sweden)

    Jie Liu

    Full Text Available Continuous use of the pesticide chlorpyrifos has resulted in harmful contaminations in environment and species. Based on a chlorpyrifos-degrading fungus Cladosporium cladosporioides strain Hu-01 (collection number: CCTCC M 20711, a fungal wettable powder preparation was developed aiming to efficiently remove chlorpyrifos residues from vegetables. The formula was determined to be 11.0% of carboxymethyl cellulose-Na, 9.0% of polyethylene glycol 6000, 5.0% of primary alcohol ethoxylate, 2.5% of glycine, 5.0% of fucose, 27.5% of kaolin and 40% of freeze dried fungi by response surface methodology (RSM. The results of quality inspection indicated that the fungal preparation could reach manufacturing standards. Finally, the degradation of chlorpyrifos by this fungal preparation was determined on pre-harvest cabbage. Compared to the controls without fungal preparation, the degradation of chlorpyrifos on cabbages, which was sprayed with the fungal preparation, was up to 91% after 7 d. These results suggested this freeze-dried fungal wettable powder may possess potential for biodegradation of chlorpyrifos residues on vegetables and provide a potential strategy for food and environment safety against pesticide residues.

  14. Neutralized wettability effect of superhydrophilic Cr-layered surface on pool boiling critical heat flux

    Energy Technology Data Exchange (ETDEWEB)

    Son, Hong Hyun; Jeong, Ui Ju; Seo, Gwang Hyeok; Jeun, Gyoo Dong; Kim, Sung Joong [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    The former method is deemed challenging due to longer development period and license issue. In this regard, FeCrAl, Cr, and SiC have been received positive attention as ATF coating materials because they are highly resistant to high temperature steam reaction causing massive hydrogen generation. In this study, Cr was selected as a target deposition material on the metal substrate because we found that Cr-layered surface becomes superhydrophilic, favorable to delaying the triggering of the critical heat flux (CHF). Thus in order to investigate the effect of Cr-layered superhydrophilic surfaces (under explored coating conditions) on pool boiling heat transfer, pool boiling experiment was conducted in the saturated deionized water under atmospheric pressure. As a physical vapor deposition (PVD) method, the DC magnetron sputtering technique was introduced to develop Cr-layered nanostructure. As a control variable of DC sputtering, substrate temperature was selected. Surface wettability and nanostructure were analyzed as major surface parameters on the CHF. We believe that highly dense micro/nano structure without nucleation cavities and inner pores neutralized the wettability effect on the CHF. Moreover, superhydrophilic surface with deficient cavity density rather hinders active nucleation. This emphasizes the importance of micro/nano structure surface for enhanced boiling heat transfer.

  15. Morphology and wettability of ZnO nanostructures prepared by hydrothermal method on various buffer layers

    Science.gov (United States)

    Li, Bao-jia; Huang, Li-jing; Zhou, Ming; Ren, Nai-fei

    2013-12-01

    Zinc oxide (ZnO) nanostructures were prepared by hydrothermal method on glass substrates with various buffer layers: Ag, Al, aluminum-doped zinc oxide (AZO) and tin-doped indium oxide (ITO). The structure, morphology and wettability of the ZnO nanostructured surfaces were investigated by using X-ray diffraction, scanning electron microscopy and water contact angle (WCA) analysis methods, respectively. All the nanostructures grown on glass with various buffer layers exhibited strong growth orientation along the (1 0 1) plane. The nature of the buffer layer was found to have remarkable effect on the morphology and wettability of the ZnO nanostructures. Whether the buffer layers were hydrophilic or low hydrophobic, all the ZnO nanostructures grown on the various buffer layers showed high hydrophobic property, and that grown on the AZO buffer layer even exhibited superhydrophobicity with a WCA of 151.1°. This work may provide a scientific basis for self-cleaning ZnO-based optoelectronic device applications.

  16. [Effect of Membrane Wettability on Membrane Fouling and Chemical Durability of SPG Membranes].

    Science.gov (United States)

    Zhang, Jing; Xiao, Tai-min; Zhang, Jing; Cao, Li-ya; Du, Ya-wei; Liu, Chun; Zhang, Lei

    2015-05-01

    Shirasu porous glass (SPG) membranes have been applied for microbubble aeration in aerobic wastewater treatment. In the present study, both hydrophilic and hydrophobic SPG membranes were used in a microbubble-aerated biofilm reactor with online chemical cleaning, and their membrane fouling and chemical durability were determined to be strongly dependent on the membrane wettability. The fouling layer formed on the surface of both membranes was confirmed to be mainly organic fouling, and the hydrophobic membrane showed a relatively stronger resistance to the organic fouling. The severe chemical corrosion of the hydrophilic membrane was observed due to exposure to the alkaline sodium hypochlorite solution used for chemical cleaning, which resulted in significant increases in the median pore diameter and the porosity. On the other hand, the pore structure of the hydrophobic membrane changed slightly when exposed to the alkaline sodium hypochlorite solution, suggesting its strong alkali-resistance due to the non-wetting surface. However, the surface hydrophobic groups of hydrophobic membrane could be oxidized by sodium hypochlorite solution, resulting in more wettable membrane surface. The hydrophobic membrane also showed better performance in the respects of oxygen transfer, contaminant removal and energy-saving. Therefore, the hydrophobic membrane seemed more appropriate to be applied for microbubble aeration in aerobic wastewater treatment process.

  17. Soil wettability can be explained by the chemical composition of particle interfaces - An XPS study.

    Science.gov (United States)

    Woche, Susanne K; Goebel, Marc-O; Mikutta, Robert; Schurig, Christian; Kaestner, Matthias; Guggenberger, Georg; Bachmann, Jörg

    2017-02-17

    Soil wettability (quantified in terms of contact angle, CA) is crucial for physical, chemical, and biological soil functioning. As the CA is determined by components present within the outmost nanometer of particles, this study applied X-ray photoelectron spectroscopy (XPS) with a maximum analysis depth of 10 nm to test the relationship between CA and surface elemental composition, using soil samples from a chronosequence where CA increased from 0° (0 yrs) to about 98° (120 yrs). Concurrently, as seen by XPS, C and N content increased and the content of O and the mineral-derived cations (Si, Al, K, Na, Ca, Mg, Fe) decreased. The C content was positively correlated with CA and least squares fitting indicated increasing amounts of non-polar C species with soil age. The contents of O and the mineral-derived cations were negatively correlated with CA, suggesting an increasing organic coating of the minerals that progressively masked the underlying mineral phase. The atomic O/C ratio was found to show a close negative relationship with CA, which applied as well to further sample sets of different texture and origin. This suggests the surface O/C ratio to be a general parameter linking surface wettability and surface elemental composition.

  18. Improvement of wettability and absorbancy of textile using atmospheric pressure dielectric barrier discharge

    Directory of Open Access Journals (Sweden)

    Bhagirath Ghimire

    2017-08-01

    Full Text Available In this study, cotton textile samples, commonly used in making quilt covers were subjected to atmospheric pressure dielectric barrier discharge treatment to study their surface wettability and absorbancy. Samples were treated in the discharge using a rotatory mechanism and the effects of plasma treatment were examined by contact angle measurement and weight measurement. Air plasma treatment was successful in incorporating hydrophilic functional groups on the textile surface due to which wettability as well as absorbancy immediately after the treatment were highly improved. Effects of plasma treatment started to appear only after 20 cycles (9 mins and got saturated after 24 cycles (10.8 mins of treatment. The contact angle reduced from 137 ° (untreated sample to a value less than 30 ° while absorbancy increased by more than two times as compared to untreated sample. Also, the aging behavior of the plasma treated samples were studied for about a week after plasma treatment. It was observed that the induced oxygen containing groups re-oriented into the bulk of the material during their storage in the environment due to which initial properties of the samples recovered gradually. Our results indicate that low temperature plasma can be successfully applied to modify the properties of textiles and textile industries could utilize this by standardization.

  19. Enhanced mixing of droplets during coalescence on a surface with a wettability gradient.

    Science.gov (United States)

    Lai, Yu-Hsuan; Hsu, Miao-Hsing; Yang, Jing-Tang

    2010-11-21

    We investigated the dynamics of head-on collisions between a moving droplet and a stationary droplet on a surface with a wettability gradient. The mixing of fluids is achieved passively through convective mass transfer caused by the release of surface energy during coalescence, and also through diffusive mass transfer. The coalescence dynamics were visualized with a high-speed camera; the internal flow patterns were resolved with measurement of micro-PIV (particle image velocimetry). The results show that the released surface energy creates a pair recirculation flow inside the merged droplet when the stationary droplet is placed near the gradient, whereas most released surface energy is converted into oscillation when the stationary droplet is far from the gradient. This distinction is attributed to the motion of the contact line during coalescence. The mixing of fluorescently labeled oligonucleotides in these two modes is revealed with confocal micro-laser induced fluorescence technique. The results of 3D scans demonstrate that the motion of the contact line during coalescence distributes the fluids in a complicated manner, thus beneficial for mixing. This mechanism of enhanced mixing is applicable also for platforms other than a surface with a wettability gradient; prospective applications include improving the mixing of biochemical fluids.

  20. Study of surface wettability effect on cavitation inception by implementation of the lattice Boltzmann method

    Science.gov (United States)

    Ezzatneshan, Eslam

    2017-11-01

    Cavitating flow through the orifice is numerically solved by implementation of the lattice Boltzmann method. The pseudo-potential single-component multiphase Shan-Chen model is used to resolve inter-particle interactions and phase change between the liquid and its vapor. The effect of surface wettability on the cavity formation and shape is studied by imposing an appropriate wall boundary condition for the contact angle between the liquid-vapor interface and the solid surface. Efficiency of the numerical approach presented is examined by computing the cavitation inception, growth, and collapse for internal cavitating flows over a sack-wall obstacle placed inside a channel and through a convergent-divergent nozzle section. The results obtained demonstrate that hydrophobic walls act as surface nuclei and contribute to the process of cavitation inception even at high cavitation numbers. In contrast, the solid wall with hydrophilic properties shows no contribution to the onset of cavitation in the geometries studied. High values for the flow velocity corresponding to low cavitation numbers are needed to observe the cavitation inception over the geometries studied with the hydrophilic solid wall. The study shows that the present computational technique based on the implementation of the lattice Boltzmann method with the Shan-Chen model employed is robust and efficient to predict the cavitation phenomena by considering surface wettability effects and also accurate enough for computing the cavitating flow properties at different conditions.

  1. Wettability and impact dynamics of water droplets on rice ( Oryza sativa L.) leaves

    Science.gov (United States)

    Kwon, Dae Hee; Huh, Hyung Kyu; Lee, Sang Joon

    2014-03-01

    We investigated the wettability and impact dynamics of water droplets on rice leaves at various leaf inclination angles and orientations. Contact angle, contact angle hysteresis (CAH), and roll-off angle ( α roll) of water droplets were measured quantitatively. Results showed that droplet motion exhibited less resistance along the longitudinal direction. Impact dynamic parameters, such as impact behaviors, maximum spreading factor, contact distance, and contact time were also investigated. Three different impact behaviors were categorized based on the normal component of Weber number irrespective of the inclination angle of the rice leaf. The asymmetric impact behavior induced by the tangential Weber number was also identified. Variation in the maximum spreading factor according to the normal Weber number was measured and compared with theoretical value obtained according to scaling law to show the wettability of the rice leaves. The contact distance of the impacting droplets depended on the inclination angle of the leaves. Along the longitudinal direction of rice leaves, contact distance was farther than that along the transverse direction. This result is consistent with the smaller values of CAH and α roll along the longitudinal direction.

  2. Wettability and corrosion of alumina embedded nanocomposite MAO coating on nanocrystalline AZ31B magnesium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Gheytani, M.; Aliofkhazraei, M., E-mail: maliofkh@gmail.com; Bagheri, H.R.; Masiha, H.R.; Rouhaghdam, A. Sabour

    2015-11-15

    In this paper, micro- and nanocrystalline AZ31B magnesium alloy were coated by micro-arc oxidation method. In order to fabricate nanocrystalline surface layer, surface mechanical attrition treatment was performed and nano-grains with average size of 5–10 nm were formed on the surface of the samples. Coating process was carried out at different conditions including two coating times and two types of electrolyte. Alumina nanoparticles were utilized as suspension in electrolyte to form nanocomposite coatings by micro-arc oxidation method. Potentiodynamic polarization, percentage of porosity, and wettability tests were performed to study various characteristics of the coated samples. The results of scanning electron microscope imply that samples coated in silicate-based electrolyte involve much lower surface porosity (∼25%). Besides, the results of wettability test indicated that the maximum surface tension with deionized water is for nanocrystalline sample. In this regard, the sample coated in silicate-based suspension was 4 times more hydrophilic than the microcrystalline sample. - Highlights: • MAO in phosphate electrolyte needs higher energy as compared to silicate electrolyte. • Less porosity and finer grain size on free surface of the silicate-based coatings. • Observed porosity from top surface of coating shows the effect of the final MAO sparks. • SMAT affects surface roughness and accelerates growth kinetics.

  3. Direct Numerical Study of a Molten Metal Drop Solidifying on a Cold Plate with Different Wettability

    Directory of Open Access Journals (Sweden)

    Truong V. Vu

    2018-01-01

    Full Text Available This paper presents a direct numerical simulation of solidification of a molten metal drop on a cold plate with various wettability by an axisymmetric front-tracking method. Because of the plate kept at a temperature below the fusion value of the melt, a thin solid layer forms at the plate and evolves upwards. The numerical results show that the solidifying front is almost flat except near the triple point with a high solidification rate at the beginning and final stages of solidification. Two solid-to-liquid density ratios ρsl = 0.9 (volume change and 1.0 (no change in volume, with two growth angles φ0 = 0° and 12° are considered. The presence of volume change and a non-zero growth angle results in a solidified drop with a conical shape at the top. The focusing issue is the effects of the wettability of the plate in terms of the contact angle φ0. Increasing the contact angle in the range of 45° to 120° increases time for completing solidification, i.e., solidification time. However, it has a minor effect on the conical angle at the top of the solidified drop and the difference between the initial liquid and final solidified heights of the drop. The effects of the density ratio and growth angle are also presented.

  4. Rock critics as 'Mouldy Modernists'

    OpenAIRE

    Shepherd, Becky

    2011-01-01

    Contemporary rock criticism appears to be firmly tied to the past. The specialist music press valorise rock music of the 1960s and 1970s, and new emerging artists are championed for their ‘retro’ sounding music by journalists who compare the sound of these new artists with those included in the established ‘canon’ of rock music. This article examines the narrative tropes of authenticity and nostalgia that frame the retrospective focus of this contemporary rock writing, and most significantly,...

  5. A Comparison of Splash Erosion Behavior between Wettable and Water Repellent 'Soil' Particles

    Science.gov (United States)

    Ahn, S.; Hamlett, C. A.; Doerr, S.; Bryant, R.; Shirtcliffe, N.; McHale, G.; Newton, M.

    2011-12-01

    Wildfires remove vegetation and litter cover and expose soil surfaces to particle detachment by rain splash. This can serve as an agent of initial soil modification and erosion in the post-fire period. Splash behavior is mainly determined by the kinetic energy delivered by impacting water drops (erosivity), and the detachability (erodibility) of surface particles, affected by their size, aggregate stability and shear strength. Soil detachability may also be affected by water repellency (hydrophobicity). This soil characteristic is influenced by wildfire and may affect splash behavior by reducing capillary forces between particles. Previous work on splash behavior using cumulative drop impact reported larger ejection droplets and lower and shorter trajectories of ejections for water repellent soil compared with wettable soil (Terry and Shakesby 1993). A water film generated by delayed infiltration on water repellent soil was suggested to account for the difference. This study compares the trajectories of ejected wettable and hydrophobic model soil particles from single water drop impacts in order to isolate the effect of soil particle wettability on splash erosion behavior. Acid-washed (wettable) and hydrophobized (water repellent) glass beads used as model soil particles were held in an array within a squat cylinder of 1.5 cm diameter in the centre of a 20 cm diameter disk covered with a viscous adhesive film. A distilled water drop (20μL) was released 40 cm above the centre of the array and the resultant impact was recorded at 976 frames per second using a high speed video camera. The populations of, and distances travelled by, the particles were measured for three arrays of bead sizes within the range (180-400 μm). Three to five replications were made for each test. The trajectory of each ejected particle was traced on video frames and corrected for the actual distance and direction of travel measured from the adhesive film. The initial velocity and ejecting

  6. Novel Application of the Flotation Technique To Measure the Wettability Changes by Ionically Modified Water for Improved Oil Recovery in Carbonates

    DEFF Research Database (Denmark)

    Sohal, Muhammad Adeel Nassar; Thyne, Geoffrey; Søgaard, Erik Gydesen

    2016-01-01

    equipment. Using this technique we were able to quantify the wettability alteration caused by low salinity and potential determining anions (PDAs) such as SO42−, BO33−, and PO43−. The wettability data show maximum oil recovery by dilution is coincident with maximum wettability alteration. The experiments...... the wettability, we need to understand the initial wetting conditions and design an ionically modified water (advanced water) to alter wettability and improve oil recovery. If a reservoir has already been reached to the optimum wetting conditions by injecting formation water or any other fluid......, then there is no need for ionically modified water. A number of methods have been devised to identify the wetting conditions including contact angle measurements, spontaneous imbibition, and chromatographic separation, etc. But contact angle measurement requires surfaces that lack natural surface roughness, spontaneous...

  7. Rock burst governance of working face under igneous rock

    Science.gov (United States)

    Chang, Zhenxing; Yu, Yue

    2017-01-01

    As a typical failure phenomenon, rock burst occurs in many mines. It can not only cause the working face to cease production, but also cause serious damage to production equipment, and even result in casualties. To explore how to govern rock burst of working face under igneous rock, the 10416 working face in some mine is taken as engineering background. The supports damaged extensively and rock burst took place when the working face advanced. This paper establishes the mechanical model and conducts theoretical analysis and calculation to predict the fracture and migration mechanism and energy release of the thick hard igneous rock above the working face, and to obtain the advancing distance of the working face when the igneous rock fractures and critical value of the energy when rock burst occurs. Based on the specific conditions of the mine, this paper put forward three kinds of governance measures, which are borehole pressure relief, coal seam water injection and blasting pressure relief.

  8. PHP frameworks

    OpenAIRE

    SRŠA, ALJAŽ

    2016-01-01

    The thesis presents one of the four most popular PHP web frameworks: Laravel, Symfony, CodeIgniter and CakePHP. These frameworks are compared with each other according to the four criteria, which can help with the selection of a framework. These criteria are size of the community, quality of official support, comprehensibility of framework’s documentation and implementation of functionalities in individual frameworks, which are automatic code generation, routing, object-relational mapping and...

  9. Framework Nette

    OpenAIRE

    Tölg, Jan

    2012-01-01

    This thesis deals with an interesting Czech PHP framework called Nette. The first part of the thesis introduces the reader to general ideas, design patterns used in Nette and also describes the main properties of the framework. Goal of the second part is focused on real-life application demonstration of the framework while developing a web application. This thesis is not an instructional material, but helps to explain the main advantages of the framework and can thus offer a more detailed des...

  10. Rock and mineral magnetism

    CERN Document Server

    O’Reilly, W

    1984-01-01

    The past two decades have witnessed a revolution in the earth sciences. The quantitative, instrument-based measurements and physical models of. geophysics, together with advances in technology, have radically transformed the way in which the Earth, and especially its crust, is described. The study of the magnetism of the rocks of the Earth's crust has played a major part in this transformation. Rocks, or more specifically their constituent magnetic minerals, can be regarded as a measuring instrument provided by nature, which can be employed in the service of the earth sciences. Thus magnetic minerals are a recording magnetometer; a goniometer or protractor, recording the directions of flows, fields and forces; a clock; a recording thermometer; a position recorder; astrain gauge; an instrument for geo­ logical surveying; a tracer in climatology and hydrology; a tool in petrology. No instrument is linear, or free from noise and systematic errors, and the performance of nature's instrument must be assessed and ...

  11. Uranium in alkaline rocks

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, M.; Wollenberg, H.; Strisower, B.; Bowman, H.; Flexser, S.; Carmichael, I.

    1978-04-01

    Geologic and geochemical criteria were developed for the occurrence of economic uranium deposits in alkaline igneous rocks. A literature search, a limited chemical analytical program, and visits to three prominent alkaline-rock localities (Ilimaussaq, Greenland; Pocos de Caldas, Brazil; and Powderhorn, Colorado) were made to establish criteria to determine if a site had some uranium resource potential. From the literature, four alkaline-intrusive occurrences of differing character were identified as type-localities for uranium mineralization, and the important aspects of these localities were described. These characteristics were used to categorize and evaluate U.S. occurrences. The literature search disclosed 69 U.S. sites, encompassing nepheline syenite, alkaline granite, and carbonatite. It was possible to compare two-thirds of these sites to the type localities. A ranking system identified ten of the sites as most likely to have uranium resource potential.

  12. Limados : Rock peruano

    OpenAIRE

    García Morete, Ramiro

    2013-01-01

    Incentivado por la corriente nuevaolera que llegaba de México, fue señalado por especialistas como pionero del punk. Aunque el plan, era tocar con lo que hubiera. Un recodo ínfimo de un período breve pero sorprendentemente poderoso, los 60 en un país que hizo del rock una expresión propia de su cultura. Facultad de Periodismo y Comunicación Social

  13. Rock pushing and sampling under rocks on Mars

    Science.gov (United States)

    Moore, H.J.; Liebes, S.; Crouch, D.S.; Clark, L.V.

    1978-01-01

    Viking Lander 2 acquired samples on Mars from beneath two rocks, where living organisms and organic molecules would be protected from ultraviolet radiation. Selection of rocks to be moved was based on scientific and engineering considerations, including rock size, rock shape, burial depth, and location in a sample field. Rock locations and topography were established using the computerized interactive video-stereophotogrammetric system and plotted on vertical profiles and in plan view. Sampler commands were developed and tested on Earth using a full-size lander and surface mock-up. The use of power by the sampler motor correlates with rock movements, which were by plowing, skidding, and rolling. Provenance of the samples was determined by measurements and interpretation of pictures and positions of the sampler arm. Analytical results demonstrate that the samples were, in fact, from beneath the rocks. Results from the Gas Chromatograph-Mass Spectrometer of the Molecular Analysis experiment and the Gas Exchange instrument of the Biology experiment indicate that more adsorbed(?) water occurs in samples under rocks than in samples exposed to the sun. This is consistent with terrestrial arid environments, where more moisture occurs in near-surface soil un- der rocks than in surrounding soil because the net heat flow is toward the soil beneath the rock and the rock cap inhibits evaporation. Inorganic analyses show that samples of soil from under the rocks have significantly less iron than soil exposed to the sun. The scientific significance of analyses of samples under the rocks is only partly evaluated, but some facts are clear. Detectable quantities of martian organic molecules were not found in the sample from under a rock by the Molecular Analysis experiment. The Biology experiments did not find definitive evidence for Earth-like living organisms in their sample. Significant amounts of adsorbed water may be present in the martian regolith. The response of the soil

  14. Rock in Rio: forever young

    Directory of Open Access Journals (Sweden)

    Ricardo Ferreira Freitas

    2014-12-01

    Full Text Available The purpose of this article is to discuss the role of Rock in Rio: The Musical, as herald of megafestival Rock in Rio. Driven by the success that musicals have reached in Brazil, we believe that the design of this spectacle of music, dance and staging renews the brand of the rock festival, once it adds the force of young and healthy bodies to its concept. Moreover, the musical provides Rock in Rio with some distance from the controversal trilogy of sex, drugs and rock and roll, a strong mark of past festivals around the world. Thus, the musical expands the possibilities of growth for the brand.

  15. 75 FR 1421 - BlackRock, Inc.; Notice of Application

    Science.gov (United States)

    2010-01-11

    ... affiliation between Merrill Lynch (the solicitor's parent entity) and BlackRock (the recommended adviser's parent entity) such that, within the policy framework of the Cash Solicitation Rule, these additional... Solicitation Rule, (ii) requiring strict compliance with the Independent Solicitor Provision would create risks...

  16. Microbial biofilm growth versus tissue integration on biomaterials with different wettabilities and a polymer-brush coating

    NARCIS (Netherlands)

    Subbiahdoss, Guruprakash; Grijpma, Dirk W.; van der Mei, Henny C.; Busscher, Henk J.; Kuijer, Roel

    2010-01-01

    Biomaterials-associated infections (BAI) constitute a major clinical problem and often necessitate implant replacement. In this study, the race for the surface between Staphylococcus epidermidis ATCC 35983 and U2OS osteosarcoma cells is studied on biomaterials with different wettabilities and on a

  17. Microbial biofilm growth versus tissue integration on biomaterials with different wettabilities and a polymer-brush coating

    NARCIS (Netherlands)

    Subbiahdoss, Guruprakash; Grijpma, Dirk W.; van der Mei, Henny C.; Busscher, Henk J.; Kuijer, Roel

    Biomaterials-associated infections (BAI) constitute a major clinical problem and often necessitate implant replacement. In this study, the race for the surface between Staphylococcus epidermidis ATCC 35983 and U2OS osteosarcoma cells is studied on biomaterials with different wettabilities and on a

  18. Effect of surface mechanical attrition treatment (SMAT) on microhardness, surface roughness and wettability of AISI 316L

    NARCIS (Netherlands)

    Arifvianto, B.; Suyitno, [No Value; Mahardika, M.; Dewo, P.; Iswanto, P. T.; Salim, U. A.

    2011-01-01

    Surface roughness and wettability are among the surface properties which determine the service lifetime of materials. Mechanical treatments subjected to the surface layer of materials are often performed to obtain the desired surface properties and to enhance the mechanical strength of materials. In

  19. A Brief Research Review for Improvement Methods the Wettability between Ceramic Reinforcement Particulate and Aluminium Matrix Composites

    Science.gov (United States)

    Razzaq, Alaa Mohammed; Majid, Dayang Laila Abang Abdul; Ishak, M. R.; B, Uday M.

    2017-05-01

    The development of new methods for addition fine ceramic powders to Al aluminium alloy melts, which would lead to more uniform distribution and effective incorporation of the reinforcement particles into the aluminium matrix alloy. Recently the materials engineering research has moved to composite materials from monolithic, adapting to the global need for lightweight, low cost, quality, and high performance advanced materials. Among the different methods, stir casting is one of the simplest ways of making aluminium matrix composites. However, it suffers from poor distribution and combination of the reinforcement ceramic particles in the metal matrix. These problems become significantly effect to reduce reinforcement size, more agglomeration and tendency with less wettability for the ceramic particles in the melt process. Many researchers have carried out different studies on the wettability between the metal matrix and dispersion phase, which includes added wettability agents, fluxes, preheating the reinforcement particles, coating the reinforcement particles, and use composting techniques. The enhancement of wettability of ceramic particles by the molten matrix alloy and the reinforcement particles distribution improvement in the solidified matrix is the main objective for many studies that will be discussed in this paper.

  20. Flexible, High-Wettability and Fire-Resistant Separators Based on Hydroxyapatite Nanowires for Advanced Lithium-Ion Batteries.

    Science.gov (United States)

    Li, Heng; Wu, Dabei; Wu, Jin; Dong, Li-Ying; Zhu, Ying-Jie; Hu, Xianluo

    2017-10-16

    Separators play a pivotal role in the electrochemical performance and safety of lithium-ion batteries (LIBs). The commercial microporous polyolefin-based separators often suffer from inferior electrolyte wettability, low thermal stability, and severe safety concerns. Herein, a novel kind of highly flexible and porous separator based on hydroxyapatite nanowires (HAP NWs) with excellent thermal stability, fire resistance, and superior electrolyte wettability is reported. A hierarchical cross-linked network structure forms between HAP NWs and cellulose fibers (CFs) via hybridization, which endows the separator with high flexibility and robust mechanical strength. The high thermal stability of HAP NW networks enables the separator to preserve its structural integrity at temperatures as high as 700 °C, and the fire-resistant property of HAP NWs ensures high safety of the battery. In particular, benefiting from its unique composition and highly porous structure, the as-prepared HAP/CF separator exhibits near zero contact angle with the liquid electrolyte and high electrolyte uptake of 253%, indicating superior electrolyte wettability compared with the commercial polyolefin separator. The as-prepared HAP/CF separator has unique advantages of superior electrolyte wettability, mechanical robustness, high thermal stability, and fire resistance, thus, is promising as a new kind of separator for advanced LIBs with enhanced performance and high safety. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Adhesion of blood platelets under flow to wettability gradient polyethylene surfaces made in a shielded gas plasma

    NARCIS (Netherlands)

    Spijker, HT; Busscher, HJ; Graaff, R; van Oeveren, W; Bos, R.R.M.

    2002-01-01

    Adhesion and activation of platelets are important steps in the thrombosis of blood after contact with a biomaterial surface and are governed, in part, by the wettability of the surface. Since most implanted devices are in contact with blood under flow conditions, it is important to study the effect

  2. Amyloid proteins are highly abundant in water-repellent but not wettable soils: microbial differentiation matters to soils

    Science.gov (United States)

    van Keulen, Geertje; Quinn, Gerry; Sinclair, Kat; Dudley, Ed; Swain, Martin; Doerr, Stefan; Matthews, Peter; Francis, Lewis; Gazze, Andrea; Hallin, Ingrid

    2017-04-01

    Soil water repellency is a common phenomenon affecting the hydrological responses of many soil and land use types in different climates. This in turn leads to decreased water infiltration, reduced vegetation cover, fertiliser run off and soil erosion. The fundamental (biological) causes of (bulk) soil repellency and its dynamic behaviour remain poorly understood. We have applied soil metaproteomics, the systemic extraction and identification of proteins from a soil, to understand the biological (adaptive) processes and potential for bio-modification of mineral surfaces, which occur at the molecular level in soils switching between wettable and repellent states. Extreme, moderate and sub-critical water-repellent UK silt-loam soils under permanent grass vegetation, including Park Grass at Rothamsted Research, were sampled below the root zone depth under wettable and repellent conditions. Soils were subjected to our new extraction methods for determining the specific ultrahydrophobic and total metaproteomes. Using our ultrahydrophobic extraction protocol, we have identified more than 200, mostly novel amyloid, proteins, which could be extracted from water-repellent soils, but were absent in the comparable wettable soils. One of the novel amyloid proteins was highly abundant in all soils, which has the potential as a soil biomarker for precision land management, especially in irrigation. Comparative profiling of the total metaproteomes of wettable and repellent soils has revealed similarities and dissimilarities in microbial diversity and their activities, which have created a deeper understanding of soil system processes common and adaptive to soil moisture and to the severity of repellence.

  3. Surface Modification of Anisotropic Dielectric Elastomer Actuators with Uni- and Bi-axially Wrinkled Carbon Electrodes for Wettability Control.

    Science.gov (United States)

    Jun, Kiwoo; Kim, Donggyu; Ryu, Seunghwa; Oh, Il-Kwon

    2017-07-20

    Interest in soft actuators for next-generation electronic devices, such as wearable electronics, haptic feedback systems, rollable flexible displays, and soft robotics, is rapidly growing. However, for more practical applications in diverse electronic devices, soft actuators require multiple functionalities including anisotropic actuation in three-dimensional space, active tactile feedback, and controllable wettability. Herein, we report anisotropic dielectric elastomer actuators with uni- and bi-axially wrinkled carbon black electrodes that are formed through pre-streching and relaxation processes. The wrinkled dielectric elastomer actuator (WDEA) that shows directional actuation under electric fields is used to control the anisotropic wettability. The morphology changes of the electrode surfaces under various electric stimuli are investigated by measuring the contact angles of water droplets, and the results show that the controllable wettability has a broad range from 141° to 161° along the wrinkle direction. The present study successfully demonstrates that the WDEA under electrically controlled inputs can be used to modulate the uni- or bi-axially wrinkled electrode surfaces with continous roughness levels. The controllable wrinkled structures can play an important role in creating adaptable water repellency and tunable anisotropic wettability.

  4. Modulation of the wettability of excipients by surfactant and its impacts on the disintegration and release of tablets.

    Science.gov (United States)

    Yang, Baixue; Xu, Lu; Wang, Qiuxiao; Li, Sanming

    2016-12-01

    To investigate the modulation of the wettability of excipients by different types of surfactants and its impacts on the disintegration of tablets and drug release. The critical micelle concentration (CMC) of surfactants, including sodium dodecyl sulfate (SDS), sodium dodecyl benzene sulfonate (SDBS), dodecyl trimethyl ammonium bromide (DTAB), cetyltrimethyl ammonium bromide (CTAB) and polysorbate (Tween-20 and Tween-80), was obtained using the platinum ring method. Contact angles of surfactant solutions on the excipient compacts and double-distilled water on the mixture of surfactant and the other excipient (magnesium stearate (MgSt) or sodium alginate (SA)) were measured by the sessile drop technique. Besides, surface free energy of excipients was calculated by the Owens method. Finally, the disintegration of tablets and in vitro dissolution testing were performed according to the method described in USP. The wettability of excipients could be enhanced to different extent with low concentration of surfactant solutions and maintained stable basically after CMC. For MgSt (hydrophobic excipient), the shorter the hydrophobic chain (C12, including SDS and DTAB), the better the wettability with the addition of surfactant in the formulation, leading to the shorter disintegration time of tablets and higher drug release rate. In contrast, the wettability of SA (hydrophilic excipient) was reduced by adding surfactant, resulting in the longer disintegration time of tablets and lower release rate. The modulation of the wetting of pharmaceutical excipients by surfactant had changed the disintegration time of tablets and drug release rate to a greater extent.

  5. Improving wettability of photo-resistive film surface with plasma surface modification for coplanar copper pillar plating of IC substrates

    Science.gov (United States)

    Xiang, Jing; Wang, Chong; Chen, Yuanming; Wang, Shouxu; Hong, Yan; Zhang, Huaiwu; Gong, Lijun; He, Wei

    2017-07-01

    The wettability of the photo-resistive film (PF) surfaces undergoing different pretreatments including the O2sbnd CF4 low-pressure plasma (OCLP) and air plasma (AP), is investigated by water contact angle measurement instrument (WCAMI) before the bottom-up copper pillar plating. Chemical groups analysis performed by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectra (XPS) shows that after the OCLP and wash treatment, the wettability of PF surface is attenuated, because embedded fluorine and decreased oxygen content both enhance hydrophobicity. Compared with OCLP treatment, the PF surface treatment by non-toxic air plasma displays features of Csbnd O, Osbnd Cdbnd O, Cdbnd O and sbnd NO2 by AIR-FTIR and XPS, and a promoted wettability by WCAM. Under the identical electroplating condition, the surface with a better wettability allows electrolyte to spontaneously soak all the places of vias, resulting in improved copper pillar uniformity. Statistical analysis of metallographic data shows that more coplanar and flat copper pillars are achieved with the PF treatment of air plasma. Such modified copper-pillar-plating technology meets the requirement of accurate impedance, the high density interconnection for IC substrates.

  6. Effects of ionic and nonionic surfactants on milk shell wettability during co-spray-drying of whole milk particles.

    Science.gov (United States)

    Lallbeeharry, P; Tian, Y; Fu, N; Wu, W D; Woo, M W; Selomulya, C; Chen, X D

    2014-09-01

    Mixing surfactants with whole milk feed before spray drying could be a commercially favorable approach to produce instant whole milk powders in a single step. Pure whole milk powders obtained directly from spray drying often have a high surface fat coverage (up to 98%), rendering them less stable during storage and less wettable upon reconstitution. Dairy industries often coat these powders with lecithin, a food-grade surfactant, in a secondary fluidized-bed drying stage to produce instant powders. This study investigated the changes in wetting behavior on the surface of a whole milk particle caused by the addition of surfactants before drying. Fresh whole milk was mixed with 0.1% (wt/wt) Tween 80 or 1% (wt/wt) lecithin (total solids), and the wetting behavior of the shell formed by each sample was captured using a single-droplet drying device at intermediate drying stages as the shell was forming. The addition of surfactants improved shell wettability from the beginning of shell formation, producing more wettable milk particles after drying. The increase in surfactant loading by 10 times reduced the wetting time from around 30s to 30s). We proposed that Tween 80 could adsorb at the oil-water interface of fat globules, making the surface fat more wettable, whereas lecithin tends to combine with milk proteins to form a complex, which then competes for the air-water surface with fat globules. Spray-drying experiments confirmed the greatly improved wettability of whole milk powders by the addition of either 0.1% (wt/wt) Tween 80 or 1% (wt/wt) lecithin; wetting time was reduced from 35±4s to drying system has been used to elucidate the complex interactions between ionic or nonionic surfactants and milk components (both proteins and fat), as well as the resultant effect on the development of milk particle functionality during drying. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  7. Impact of surfactant-induced wettability alterations on DNAPL invasion in quartz and iron oxide-coated sand systems.

    Science.gov (United States)

    Molnar, Ian L; O'Carroll, Denis M; Gerhard, Jason I

    2011-01-25

    Dense non-aqueous phase liquids (DNAPLs) present in the subsurface may contain surface active compounds that impact DNAPL migration and distribution. While a number of studies have revealed the role surface active compounds play in altering the wettability of quartz sand, few have considered the implications for other minerals common to contaminated sites. This study extends understanding of DNAPL/surfactant wettability to iron oxide surfaces. Specifically, quartz and iron oxide-coated sands in a tetrachloroethene (PCE)/water system containing the organic base (an organic molecule that acts as a base) dodecylamine (DDA) were compared at a variety of scales. Wettability of the minerals' surfaces, and the impact of wettability on capillary resistance to DNAPL entry, were assessed as a function of pH through: (i) advancing and receding contact angles, (ii) primary drainage capillary pressure-saturation experiments, and (iii) small, two-dimensional, flow cell experiments. The work revealed that, at neutral pH and under identical boundary capillary pressures, DNAPL invaded quartz sand but not iron oxide-coated sand; however, at low pH, DNAPL invaded both sands equally. These differences were demonstrated to be due to wettability alterations associated with the strength of attractive forces between DDA and the mineral surface, dictated by the isolectric point of the minerals and system pH. Observed differences in DNAPL invasion behavior were consistent with measured intrinsic contact angles and P(c)-S relationships, the latter requiring scaling by the operative contact angle inside the porous medium for a meaningful comparison. This study suggests that the distribution of minerals (and, more specifically, their isoelectric points), as well as the aqueous phase pH at a given site, may have a significant impact on the DNAPL source zone architecture. Copyright © 2010 Elsevier B.V. All rights reserved.

  8. Tuning of wettability of PANI-GNP composites using keV energy ions

    Energy Technology Data Exchange (ETDEWEB)

    Lakshmi, G.B.V.S., E-mail: lakshmigbvs@gmail.com [Inter University Accelerator Centre, New Delhi 67 (India); Avasthi, D.K. [Amity University, Noida 201313, Uttar Pradesh (India)

    2016-07-15

    Polyaniline nanofiber composites with various nanomaterials have several applications in electrochemical biosensors. The surface properties of these composites coated electrodes play crucial role in enzyme absorption and analyte detection process. In the present study, Polyaniline-Graphene nanopowder (PANI-GNP) composites were prepared by rapid-mixing polymerization method. The films were prepared on ITO coated glass substrates and irradiated with 42 keV He{sup +} ions produced by indigenously fabricated accelerator at IUAC, New Delhi. The films were characterized before and after irradiation by SEM, Raman spectroscopy and contact angle measurements. The as-prepared films show superhydrophilic nature and after irradiation the films show highly hydrophobic nature with water contact angle (135°). The surface morphology was studied by SEM and structural changes were studied by Raman spectra. The surface morphological modifications induced by keV energy ions helps in tuning the wettability at different ion fluences.

  9. Predicting wettability behavior of fluorosilica coated metal surface using optimum neural network

    Science.gov (United States)

    Taghipour-Gorjikolaie, Mehran; Valipour Motlagh, Naser

    2018-02-01

    The interaction between variables, which are effective on the surface wettability, is very complex to predict the contact angles and sliding angles of liquid drops. In this paper, in order to solve this complexity, artificial neural network was used to develop reliable models for predicting the angles of liquid drops. Experimental data are divided into training data and testing data. By using training data and feed forward structure for the neural network and using particle swarm optimization for training the neural network based models, the optimum models were developed. The obtained results showed that regression index for the proposed models for the contact angles and sliding angles are 0.9874 and 0.9920, respectively. As it can be seen, these values are close to unit and it means the reliable performance of the models. Also, it can be inferred from the results that the proposed model have more reliable performance than multi-layer perceptron and radial basis function based models.

  10. Surface wettability of (3-aminopropyl)triethoxysilane self-assembled monolayers.

    Science.gov (United States)

    Zeng, Xiangxuan; Xu, Guohua; Gao, Yuan; An, Yue

    2011-01-27

    The (3-aminopropyl)triethoxysilane (APTES) self-assembled monolayer (SAM) has been widely used in fundamental research and engineering applications; however, characterization of its surface wetting properties remains problematic. Surface wetting properties of the APTES SAM were systematically investigated using different contact angle measurement techniques. The observed unique nonideal wetting was related to the APTES SAM structure, including surface hydrogen bond formation, the surface roughness, and the effect of water penetration. The contact angle decreased dramatically with the residence time on the APTES SAM surface, and a special contact angle hysteresis phenomenon was observed. The contact angle could be distorted by the calculation method used for the nonideal APTES SAM surface. Values calculated by the tangent-leaning method were thought to be more accurate and credible. Our findings demonstrated that static advancing contact angles were the most stable and credible for characterizing the APTES SAM surface wettability.

  11. Wettability and Corrosion Behavior of Chemically Modified Plasma Electrolytic Oxidation Nanocomposite Coating

    Science.gov (United States)

    Farhadi, S. S.; Aliofkhazraei, M.; Barati Darband, Gh.; Abolhasani, A.; Sabour Rouhaghdam, A.

    2017-10-01

    The aim of this paper was to investigate the effect of potassium stearate on the wettability behavior, corrosion resistance, roughness and thickness of reinforced and unreinforced plasma electrolytic oxidation (PEO) coatings with Si3N4 nanopowders. Morphological characteristic, corrosion behavior and wetting properties of the coatings were evaluated using SEM, cyclic polarization and Wilhelmy plate method, respectively. In order to obtain a better evaluation of the contact angle, roughness of the coatings was studied by AFM. The results indicated that the nanocomposite hydrophobic coatings have the best corrosion resistance. Potassium stearate could repel water from the holes of coating by reacting with aluminum and producing aluminum stearate. The contact angle of nanocomposite and normal PEO coatings was increased up to 65° due to the addition of potassium stearate. This additive could also increase the hysteresis contact angle up to 51°.

  12. Tuning of wettability of PANI-GNP composites using keV energy ions

    Science.gov (United States)

    Lakshmi, G. B. V. S.; Avasthi, D. K.

    2016-07-01

    Polyaniline nanofiber composites with various nanomaterials have several applications in electrochemical biosensors. The surface properties of these composites coated electrodes play crucial role in enzyme absorption and analyte detection process. In the present study, Polyaniline-Graphene nanopowder (PANI-GNP) composites were prepared by rapid-mixing polymerization method. The films were prepared on ITO coated glass substrates and irradiated with 42 keV He+ ions produced by indigenously fabricated accelerator at IUAC, New Delhi. The films were characterized before and after irradiation by SEM, Raman spectroscopy and contact angle measurements. The as-prepared films show superhydrophilic nature and after irradiation the films show highly hydrophobic nature with water contact angle (135°). The surface morphology was studied by SEM and structural changes were studied by Raman spectra. The surface morphological modifications induced by keV energy ions helps in tuning the wettability at different ion fluences.

  13. Improved thermal stability and wettability behavior of thermoplastic polyurethane / barium metaborate composites

    Energy Technology Data Exchange (ETDEWEB)

    Baştürka, Emre; Madakbaş, Seyfullah; Kahraman, Memet Vezir, E-mail: smadakbas@marmara.edu.tr [Department of Chemistry, Marmara University, Istanbul (Turkey)

    2016-03-15

    In this paper, it was targeted to the enhance thermal stability and wettability behavior of thermoplastic polyurethane (TPU) by adding barium metaborate. TPU-Barium metaborate composites were prepared by adding various proportions of barium metaborate to TPU. The chemical structures of the composites were characterised by fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis. All prepared composites have extremely high Tg and thermal stability as determined from DSC and TGA analysis. All composite materials have the Tg ranging from 15 to 35 °C. The surface morphologies of the composites were investigated by a scanning electron microscopy. Mechanical properties of the samples were characterized with stress-strain test. Hydrophobicity of the samples was determined by the contact angle measurements. The obtained results proved that thermal, hydrophobic and mechanical properties were improved. (author)

  14. Wettability, Shrinkage and Color Changes of Araucaria angustifolia After Heating Treatment

    Directory of Open Access Journals (Sweden)

    Rodrigo Marques de Oliveira

    2010-09-01

    Full Text Available The effects of thermal treatment on the wettability and shrink resistance of Araucaria angustifolia (Parana pine were studied from 20 to 200 °C. The contact angles of water droplets on untreated and heat-treated samples were measured by the sessile drop method in the grain of heartwood and sapwood cut in the radial, longitudinal, and tangential directions. A significant increase of the contact angles was verified for the samples from room temperature to 120 °C, in particular in the radial and tangential directions; at higher temperatures, the contact angles assumed almost constant values. From 120 to 200 °C, the sapwood of Araucaria angustifolia showed better dimensional stability and lower thermal resistance when compared to the heartwood. Variations of color were also studied by using the CIELab system, which showed to be capable of accurately distinguishing samples treated at different temperatures.

  15. Polymeric Shape-Memory Micro-Patterned Surface for Switching Wettability with Temperature

    Directory of Open Access Journals (Sweden)

    Nuria García-Huete

    2015-09-01

    Full Text Available An innovative method to switch the wettability of a micropatterned polymeric surface by thermally induced shape memory effect is presented. For this purpose, first polycyclooctene (PCO is crosslinked with dycumil peroxide (DCP and its melting temperature, which corresponds with the switching transition temperature (Ttrans, is measured by Dynamic Mechanical Thermal Analysis (DMTA in tension mode. Later, the shape memory behavior of the bulk material is analyzed under different experimental conditions employing a cyclic thermomechanical analysis (TMA. Finally, after creating shape memory micropillars by laser ablation of crosslinked thermo-active polycyclooctene (PCO, shape memory response and associated effect on water contact angle is analyzed. Thus, deformed micropillars cause lower contact angle on the surface from reduced roughness, but the original hydrophobicity is restored by thermally induced recovery of the original surface structure.

  16. From stones to rocks

    Science.gov (United States)

    Mortier, Marie-Astrid; Jean-Leroux, Kathleen; Cirio, Raymond

    2013-04-01

    With the Aquila earthquake in 2009, earthquake prediction is more and more necessary nowadays, and people are waiting for even more accurate data. Earthquake accuracy has increased in recent times mainly thanks to the understanding of how oceanic expansion works and significant development of numerical seismic prediction models. Despite the improvements, the location and the magnitude can't be as accurate as citizen and authorities would like. The basis of anticipating earthquakes requires the understanding of: - The composition of the earth, - The structure of the earth, - The relations and movements between the different parts of the surface of the earth. In order to answer these questions, the Alps are an interesting field for students. This study combines natural curiosity about understanding the predictable part of natural hazard in geology and scientific skills on site: observing and drawing landscape, choosing and reading a representative core drilling, replacing the facts chronologically and considering the age, the length of time and the strength needed. This experience requires students to have an approach of time and space radically different than the one they can consider in a classroom. It also limits their imagination, in a positive way, because they realize that prediction is based on real data and some of former theories have become present paradigms thanks to geologists. On each location the analyzed data include landscape, core drilling and the relation established between them by students. The data is used by the students to understand the meaning, so that the history of the formation of the rocks tells by the rocks can be explained. Until this year, the CBGA's perspective regarding the study of the Alps ground allowed students to build the story of the creation and disappearance of the ocean, which was a concept required by French educational authorities. But not long ago, the authorities changed their scientific expectations. To meet the

  17. Investigation of antibacterial and wettability behaviours of plasma-modified PMMA films for application in ophthalmology

    Science.gov (United States)

    Rezaei, Fatemeh; Abbasi-Firouzjah, Marzieh; Shokri, Babak

    2014-02-01

    The main objective of this research is the experimental investigation of the surface properties of polymethyl methacrylate (PMMA) such as wettability and the roughness effect on Escherichia coli (gram negative) cell adhesion. Radio frequency (RF; 13.56 MHz) oxygen plasma was used to enhance the antibacterial and wettability properties of this polymer for biomedical applications, especially ophthalmology. The surface was activated by O2 plasma to produce hydrophilic functional groups. Samples were treated with various RF powers from 10 to 80 W and different gas flow rates from 20 to 120 sccm. Optical emission spectroscopy was used to monitor the plasma process. The modified surface hydrophilicity, morphology and transparency characteristics were studied by water contact angle measurements, atomic force microscopy and UV-vis spectroscopy, respectively. Based on the contact angle measurements of three liquids, surface free energy variations were investigated. Moreover, the antibacterial properties were evaluated utilizing the method of plate counting of Escherichia coli. Also, in order to investigate stability of the plasma treatment, an ageing study was carried out by water contact angle measurements repeated in the days after the treatment. For biomedical applications, especially eye lenses, highly efficient antibacterial surfaces with appropriate hydrophilicity and transparency are of great importance. In this study, it is shown that the plasma process is a reliable and convenient method to achieve these purposes. A significant alteration in the hydrophilicity of a pristine PMMA surface was observed after treatment. Also, our results indicated that the plasma-modified PMMAs exhibit appropriate antibacterial performance. Moreover, surface hydrophilicity and surface charge have more influence on bacterial adhesion rate than surface roughness. UV-vis analysis results do not show a considerable difference for transparency of samples after plasma treatment.

  18. Preparation of spray-dried wettable powder formulations of Bacillus thuringiensis-based biopesticides.

    Science.gov (United States)

    Teera-Arunsiri, Aroonrat; Suphantharika, Manop; Ketunuti, Uthai

    2003-04-01

    Bacillus thuringiensis is the most widely used biopesticide among many methods available to control insects. To make a saleable product, B. thuringiensis must be substantially concentrated by removal of water and formulated to improve longevity, efficacy, and ease of transport of the product. B. thuringiensis subsp. aizawai culture broth as an active ingredient was mixed with various adjuvants and then spray dried. The optimum conditions for spray drying were found to be an outlet temperature of 60-85 degrees C and an inlet temperature of 120-180 degrees C. Various adjuvants had different effects on physical and biological properties of the dried product. Gelatinized tapioca starch and milk powder improved suspensibility but adversely affected wettability of the dried formulated product. Vegetable oil and Tween 20 enhanced wettability but resulted in poor suspensibility. Silica fume was used to enhance flowability because it reduced clumping and caking of the powder resulting from the addition of vegetable oil. Formulation containing 10% wt:wt B. thuringiensis, 10% wt:wt gelatinized tapioca starch, 10% wt:wt sucrose, 38% wt:wt tapioca starch, 20% wt:wt milk powder, 10% wt:wt silica fume, 2% wt:wt polyvinyl alcohol, 5% vol:vol Tween 20, 1% vol:vol refined rice bran oil, and 1% vol:vol antifoam solution was found to be optimum in terms of the physical and biological properties of the dried product. This formulation had 55% suspensibility, 24 s for wetting time, and 5.69 x 10(4) CFU/ml of LC50 value against Spodoptera exigua larvae.

  19. Microstructure and wettability of root canal dentine and root canal filling materials after different chemical irrigation

    Energy Technology Data Exchange (ETDEWEB)

    Antonijevic, Djordje; Milovanovic, Petar [Laboratory for Anthropology, Institute for Anatomy, Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Brajkovic, Denis [Department of Dentistry, Faculty of Medical Sciences, University of Kragujevac, Kragujevac (Serbia); Ilic, Dragan [Department of Restorative Medicine, School of Dental Medicine, University of Belgrade, Belgrade (Serbia); Hahn, Michael; Amling, Michael [Department of Osteology and Biomechanics (IOBM), University Medical Center Hamburg-Eppendorf, Lottestr. 55A, 22529 Hamburg (Germany); Rakocevic, Zlatko [Laboratory for Atomic Physics, Institute for Nuclear Science “Vinca”, University of Belgrade, Belgrade (Serbia); Djuric, Marija [Laboratory for Anthropology, Institute for Anatomy, Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Busse, Björn, E-mail: b.busse@uke.uni-hamburg.de [Department of Osteology and Biomechanics (IOBM), University Medical Center Hamburg-Eppendorf, Lottestr. 55A, 22529 Hamburg (Germany)

    2015-11-15

    Graphical abstract: - Highlights: • Different irrigation solutions and disinfectants were used for treatment of root canal dentine and gutta-percha points. • Materials surface characteristics were assessed using quantitative backscattered electron imaging, reference point indentation, and contact angle analyzer. • The most significant differences in mineralization, indentation, and adhesive outcomes were observed after ethylenediaminetetraacetic acid treatment. • Irrigation solutions confer to superior sealing ability of endodontic filling materials. • Micromechanical characteristics of dentine after irrigation are considerable reduced. - Abstract: The objective of this study was to determine the effects of various irrigation solutions on root canal dentine and gutta-percha surface properties. In addition, the effects of disinfectant chemicals on the wettability and surface morphological properties of the filling materials were evaluated. Ethylenediaminetetraacetic acid (EDTA), citric acid, and ozone were employed as irrigation solutions for dentine and gutta-percha treatment. Thereafter, the samples’ microstructure, degree of mineralization, and mechanical properties were assessed by means of quantitative backscattered electron imaging (qBEI) and reference point indentation (RPI). A contact angle analyzer was used to measure adhesion on the tested materials. Here, EDTA had the most significant affect on both the mechanical properties and the adhesive behavior of dentine. Citric acid did not affect dentine wettability, whereas the indentation properties and the mineralization were reduced. Similar effects were observed when ozone was used. The dentinal tubules were significantly widened in citric acid compared to the ozone group. EDTA causes considerable micromechanical surface alteration of dentine and gutta-percha, but represents the best option in clinical cases where a high adhesiveness of the filling materials is desired.

  20. Aespoe Hard Rock Laboratory Annual report 2003

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-09-01

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a deep geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site for a deep repository. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create an opportunity for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. Aespoe HRL has been in operation since 1995 and the associated research, development, and demonstration tasks, have so far attracted considerable interest. A summary of work performed at Aespoe HRL during 2003 is given below. Seven organisations from six countries participated in the co-operation at Aespoe HRL during 2003 in addition to SKB. Most of the organisations are interested in groundwater flow, radionuclide transport and rock characterisation. Several of the organisations are participating in the experimental work as well as in the Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes. SKB is through Repository Technology co-ordinating three EC contracts and takes part in several EC projects of which the representation in five projects is channelled through Repository Technology. SKB takes also part in work within the IAEA framework.

  1. Characterization and Alteration of Wettability States of Alaskan Reserviors to Improve Oil Recovery Efficiency (including the within-scope expansion based on Cyclic Water Injection - a pulsed waterflood for Enhanced Oil Recovery)

    Energy Technology Data Exchange (ETDEWEB)

    Abhijit Dandekar; Shirish Patil; Santanu Khataniar

    2008-12-31

    Numerous early reports on experimental works relating to the role of wettability in various aspects of oil recovery have been published. Early examples of laboratory waterfloods show oil recovery increasing with increasing water-wetness. This result is consistent with the intuitive notion that strong wetting preference of the rock for water and associated strong capillary-imbibition forces gives the most efficient oil displacement. This report examines the effect of wettability on waterflooding and gasflooding processes respectively. Waterflood oil recoveries were examined for the dual cases of uniform and non-uniform wetting conditions. Based on the results of the literature review on effect of wettability and oil recovery, coreflooding experiments were designed to examine the effect of changing water chemistry (salinity) on residual oil saturation. Numerous corefloods were conducted on reservoir rock material from representative formations on the Alaska North Slope (ANS). The corefloods consisted of injecting water (reservoir water and ultra low-salinity ANS lake water) of different salinities in secondary as well as tertiary mode. Additionally, complete reservoir condition corefloods were also conducted using live oil. In all the tests, wettability indices, residual oil saturation, and oil recovery were measured. All results consistently lead to one conclusion; that is, a decrease in injection water salinity causes a reduction in residual oil saturation and a slight increase in water-wetness, both of which are comparable with literature observations. These observations have an intuitive appeal in that water easily imbibes into the core and displaces oil. Therefore, low-salinity waterfloods have the potential for improved oil recovery in the secondary recovery process, and ultra low-salinity ANS lake water is an attractive source of injection water or a source for diluting the high-salinity reservoir water. As part of the within-scope expansion of this project

  2. Rock Properties Model

    Energy Technology Data Exchange (ETDEWEB)

    C. Lum

    2004-09-16

    The purpose of this model report is to document the Rock Properties Model version 3.1 with regard to input data, model methods, assumptions, uncertainties and limitations of model results, and qualification status of the model. The report also documents the differences between the current and previous versions and validation of the model. The rock properties model provides mean matrix and lithophysae porosity, and the cross-correlated mean bulk density as direct input to the ''Saturated Zone Flow and Transport Model Abstraction'', MDL-NBS-HS-000021, REV 02 (BSC 2004 [DIRS 170042]). The constraints, caveats, and limitations associated with this model are discussed in Section 6.6 and 8.2. Model validation accomplished by corroboration with data not cited as direct input is discussed in Section 7. The revision of this model report was performed as part of activities being conducted under the ''Technical Work Plan for: The Integrated Site Model, Revision 05'' (BSC 2004 [DIRS 169635]). The purpose of this revision is to bring the report up to current procedural requirements and address the Regulatory Integration Team evaluation comments. The work plan describes the scope, objectives, tasks, methodology, and procedures for this process.

  3. A smart rock

    Science.gov (United States)

    Pressel, Phil

    2014-12-01

    This project was to design and build a protective weapon for a group of associations that believed in aliens and UFO's. They collected enough contributions from societies and individuals to be able to sponsor and totally fund the design, fabrication and testing of this equipment. The location of this facility is classified. It also eventually was redesigned by the Quartus Engineering Company for use at a major amusement park as a "shoot at targets facility." The challenge of this project was to design a "smart rock," namely an infrared bullet (the size of a gallon can of paint) that could be shot from the ground to intercept a UFO or any incoming suspicious item heading towards the earth. Some of the challenges to design this weapon were to feed cryogenic helium at 5 degrees Kelvin from an inair environment through a unique rotary coupling and air-vacuum seal while spinning the bullet at 1500 rpm and maintain its dynamic stability (wobble) about its spin axis to less than 10 micro-radians (2 arc seconds) while it operated in a vacuum. Precision optics monitored the dynamic motion of the "smart rock."

  4. Rock critics as 'Mouldy Modernists'

    Directory of Open Access Journals (Sweden)

    Becky Shepherd

    2011-08-01

    Full Text Available Contemporary rock criticism appears to be firmly tied to the past. The specialist music press valorise rock music of the 1960s and 1970s, and new emerging artists are championed for their ‘retro’ sounding music by journalists who compare the sound of these new artists with those included in the established ‘canon’ of rock music. This article examines the narrative tropes of authenticity and nostalgia that frame the retrospective focus of this contemporary rock writing, and most significantly, the maintenance of the rock canon within contemporary popular culture. The article concludes by suggesting that while contemporary rock criticism is predominately characterised by nostalgia, this nostalgia is not simply a passive romanticism of the past. Rather, this nostalgia fuels a process of active recontextualisation within contemporary popular culture.

  5. An experimental and theoretical study to relate uncommon rock/fluid properties to oil recovery. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Watson, R.

    1995-07-01

    Waterflooding is the most commonly used secondary oil recovery technique. One of the requirements for understanding waterflood performance is a good knowledge of the basic properties of the reservoir rocks. This study is aimed at correlating rock-pore characteristics to oil recovery from various reservoir rock types and incorporating these properties into empirical models for Predicting oil recovery. For that reason, this report deals with the analyses and interpretation of experimental data collected from core floods and correlated against measurements of absolute permeability, porosity. wettability index, mercury porosimetry properties and irreducible water saturation. The results of the radial-core the radial-core and linear-core flow investigations and the other associated experimental analyses are presented and incorporated into empirical models to improve the predictions of oil recovery resulting from waterflooding, for sandstone and limestone reservoirs. For the radial-core case, the standardized regression model selected, based on a subset of the variables, predicted oil recovery by waterflooding with a standard deviation of 7%. For the linear-core case, separate models are developed using common, uncommon and combination of both types of rock properties. It was observed that residual oil saturation and oil recovery are better predicted with the inclusion of both common and uncommon rock/fluid properties into the predictive models.

  6. Droplet infiltration dynamics and soil wettability related to soil organic matter of soil aggregate coatings and interiors

    Directory of Open Access Journals (Sweden)

    Fér Miroslav

    2016-06-01

    Full Text Available The organo-mineral coatings of soil aggregates, cracks, and biopores control sorption and macropore-matrix exchange during preferential flow, in particular in the clay-illuvial Bt-horizon of Luvisols. The soil organic matter (SOM composition has been hypothesized to explain temporal changes in the hydraulic properties of aggregate surfaces. The objective of this research was to find relations between the temporal change in wettability, in terms of droplet infiltration dynamics, and the SOM composition of coated and uncoated aggregate surfaces. We used 20 to 40 mm sized soil aggregates from the Bt2 horizon of a Haplic Luvisol from loess that were (i coated, (ii not coated (both intact, and (iii aggregates from which coatings were removed (cut. The SOM composition of the aggregate surfaces was characterized by infrared spectroscopy in the diffuse reflection mode (DRIFT. A potential wettability index (PWI was calculated from the ratio of hydrophobic and hydrophilic functional groups in SOM. The water drop penetration times (WDPT and contact angles (CA during droplet infiltration experiments were determined on dry and moist aggregate samples of the three types. The decrease in the CA with time was described using the power function (CA(t = at−b. For dry aggregates, the WDPT values were larger for coated as compared to uncoated regions on the aggregate surfaces, and increased with increasing PWI value (R2 = 0.75. The a parameter was significantly related to the WDPT (R2 = 0.84 and to the PWI (R2 = 0.64. The relations between the b parameter and the WDPT (R2 = 0.61 and the PWI (R2 = 0.53 were also significant. The WDPT values of wet soil aggregates were higher than those of dry aggregates due to high water contents, which limited the droplet infiltration potential. At the wet aggregate surfaces, the WDPT values increased with the PWI of the SOM (R2 = 0.64. In contrast to dry samples, no significant relationships were found between parameters a or b

  7. Rock the Globe

    CERN Multimedia

    Laëtitia Pedroso

    2010-01-01

    Created in 2005, the Swiss rock band "Wind of Change" is now candidate for the Eurovision Song Contest 2011 with a new song " Night & Light " with the music video filmed at CERN.   With over 20 gigs under their belt and two albums already released, the five members of the band (Alex Büchi, vocals; Arthur Spierer, drums; David Gantner, bass; Romain Mage and Yannick Gaudy, guitar) continue to excite audiences. For their latest composition "Night & Light", the group filmed their music video in the Globe of Science and Innovation. Winning the Eurovision contest would be a springboard in their artistic career for these young musicians. The selection results will be available December 11, 2010.      

  8. Effect of wettability-distribution pattern of the gas diffusion layer with a microgrooved separator on polymer electrolyte fuel cell performance

    Science.gov (United States)

    Utaka, Yoshio; Koresawa, Ryo

    2017-09-01

    In this study, the combination of a gas diffusion layer (GDL) with wettability distribution and gas-flow channels with microgrooves is proposed to reduce the concentration overvoltage of polymer electrolyte fuel cells. The effects of the wettability-distribution pattern and linear angle of the stripe-wise wettability distribution of the GDL on the cell performance are experimentally investigated. Examination of the wettability-distribution pattern show that not only the liquid-water distribution inside a hybrid GDL but also the liquid-water control on the GDL surface are important factors to consider in reducing the concentration overvoltage. Furthermore, in considering the hybrid angle effect, when the angle with the gas channel is shallow, especially at 20°, the critical current and maximum power are maximized.

  9. The Rock Climbing Teaching Guide.

    Science.gov (United States)

    Kudlas, John

    The product of 10 years of rock climbing instruction, this guide provides material from which an instructor can teach basic climbing concepts and safety skills as well as conduct a safe, enjoyable rock climbing class in a high school setting. It is designed for an instructor with limited experience in climbing; however, the need for teacher…

  10. Rockin' around the Rock Cycle

    Science.gov (United States)

    Frack, Susan; Blanchard, Scott Alan

    2005-01-01

    In this activity students will simulate how sedimentary rocks can be changed into metamorphic rocks by intense pressure. The materials needed are two small pieces of white bread, one piece of wheat bread, and one piece of a dark bread (such as pumpernickel or dark rye) per student, two pieces of waxed paper, scissors, a ruler, and heavy books.…

  11. Bakhtin's Dialogics and Rock Lyrics.

    Science.gov (United States)

    Knight, Jeff Parker

    Rock music is ideological both implicitly (in its intrinsic valuing of change, and resistance to authority, for instance), and explicitly (in political records from activist artists such as John Lennon and U2). The texts of the rock genre offer rhetorical experiences. A dialogic conception may help scholars to account for and describe the…

  12. Rock suitability classification RSC 2012

    Energy Technology Data Exchange (ETDEWEB)

    McEwen, T. (ed.) [McEwen Consulting, Leicester (United Kingdom); Kapyaho, A. [Geological Survey of Finland, Espoo (Finland); Hella, P. [Saanio and Riekkola, Helsinki (Finland); Aro, S.; Kosunen, P.; Mattila, J.; Pere, T.

    2012-12-15

    This report presents Posiva's Rock Suitability Classification (RSC) system, developed for locating suitable rock volumes for repository design and construction. The RSC system comprises both the revised rock suitability criteria and the procedure for the suitability classification during the construction of the repository. The aim of the classification is to avoid such features of the host rock that may be detrimental to the favourable conditions within the repository, either initially or in the long term. This report also discusses the implications of applying the RSC system for the fulfilment of the regulatory requirements concerning the host rock as a natural barrier and the site's overall suitability for hosting a final repository of spent nuclear fuel.

  13. [The influence of macro- and microstructure on the surface wettability and retention properties of endodontic posts in vitro].

    Science.gov (United States)

    Worm, Felix; Lurtz, Claudia; Behrend, Detlef; Schmitt, Lena; Schmitz, Klaus-Peter; Ottl, Peter; von Schwanewede, Heinrich

    2009-08-01

    Aesthetical and biomechanical requirements on fiber-reinforced endodontic posts play an important role in clinical application. Leading to a long-term clinical success, post systems must ensure an adequate force transmission and optimal retention behavior into the root channel. The aim of this study was to determine the microstructure and morphology of commonly used fiber reinforced endodontic posts in vitro. Post-specific fiber diameter, fiber arrangement over the cross-sections and length, and fiber-matrix ratio could be associated with mechanical properties, such as three-point bending strength and structure modulus. Furthermore, our investigation focused on the quantification of the wettability of the post surface. By using a modified contact-angle measurement, the meniscus on the post surface was characterized. In additional investigations, posts were inserted in artificial root channels and the extraction force was measured. The results show a strong correlation between the extraction force and the wettability of the post surface.

  14. Study of wettability of calcite surfaces using oil-brine-enzyme systems for enhanced oil recovery applications

    DEFF Research Database (Denmark)

    Khusainova, Alsu; Nielsen, Sidsel Marie; Pedersen, Hanne Høst

    2015-01-01

    action has been found to be replacement of oil at the solid surface by the enzyme. Other mechanisms (modification of the surface tension or catalytic modification of hydrocarbons resulting in reducing the oil viscosity) have shown to be much less pronounced from the measurements reported here.......Enzymes have recently been considered as possible agents for enhanced oil recovery (EOR) acting at the liquid-solid interface. One way to assess this is via measuring the wettability of calcite surfaces, important for EOR methods in carbonaceous reservoirs. In the present work, we have...... experimentally investigated the effect of enzymes on the wettability of calcite mineral surfaces with oil-brine systems. The action of various enzymes, including esterases/lipases, carbohydrases, proteases and oxidoreductases (along with two commercial mixtures) was studied by contact angle measurements...

  15. Effect of Temperature on Wettability and Optimum Wetting Conditions for Maximum Oil Recovery in Carbonate Reservoir System

    DEFF Research Database (Denmark)

    Sohal, Muhammad Adeel Nassar; Thyne, Geoffrey; Søgaard, Erik Gydesen

    2017-01-01

    The additional oil recovery from fractured & oil-wet carbonates by ionically modified water is principally based on changing wettability and often attributed to an improvement in water wetness. The influence of different parameters like dilution of salinity, potential anions, temperature, pressure......, lithology, pH, oil acid and base numbers to improve water wetting has been tested in recovery experiments. In these studies temperature is mainly investigated to observe the reactivity of potential anions (SO42-, PO33-, and BO33-) at different concentrations. But the influence of systematically increasing...... temperature on wetting conditions has not been thoroughly investigated. In this experimental study the effect of different temperatures on wettability for brines of different ionic strength and composition has been investigated in depth. A series of flotation experiments were conducted at 23, 50 and 100o...

  16. Selective Area Modification of Silicon Surface Wettability by Pulsed UV Laser Irradiation in Liquid Environment.

    Science.gov (United States)

    Liu, Neng; Moumanis, Khalid; Dubowski, Jan J

    2015-11-09

    The wettability of silicon (Si) is one of the important parameters in the technology of surface functionalization of this material and fabrication of biosensing devices. We report on a protocol of using KrF and ArF lasers irradiating Si (001) samples immersed in a liquid environment with low number of pulses and operating at moderately low pulse fluences to induce Si wettability modification. Wafers immersed for up to 4 hr in a 0.01% H2O2/H2O solution did not show measurable change in their initial contact angle (CA) ~75°. However, the 500-pulse KrF and ArF lasers irradiation of such wafers in a microchamber filled with 0.01% H2O2/H2O solution at 250 and 65 mJ/cm(2), respectively, has decreased the CA to near 15°, indicating the formation of a superhydrophilic surface. The formation of OH-terminated Si (001), with no measurable change of the wafer's surface morphology, has been confirmed by X-ray photoelectron spectroscopy and atomic force microscopy measurements. The selective area irradiated samples were then immersed in a biotin-conjugated fluorescein-stained nanospheres solution for 2 hr, resulting in a successful immobilization of the nanospheres in the non-irradiated area. This illustrates the potential of the method for selective area biofunctionalization and fabrication of advanced Si-based biosensing architectures. We also describe a similar protocol of irradiation of wafers immersed in methanol (CH3OH) using ArF laser operating at pulse fluence of 65 mJ/cm(2) and in situ formation of a strongly hydrophobic surface of Si (001) with the CA of 103°. The XPS results indicate ArF laser induced formation of Si-(OCH3)x compounds responsible for the observed hydrophobicity. However, no such compounds were found by XPS on the Si surface irradiated by KrF laser in methanol, demonstrating the inability of the KrF laser to photodissociate methanol and create -OCH3 radicals.

  17. Factors affecting the wettability of different surface materials with vegetable oil at high temperatures and its relation to cleanability

    Energy Technology Data Exchange (ETDEWEB)

    Ashokkumar, Saranya, E-mail: saras@food.dtu.dk [Accoat A/S, Munkegardsvej 16, 3490 Kvistgard (Denmark); Food Production Engineering, DTU FOOD, Technical University of Denmark, 2800 Kgs. Lyngby (Denmark); Adler-Nissen, Jens [Food Production Engineering, DTU FOOD, Technical University of Denmark, 2800 Kgs. Lyngby (Denmark); Moller, Per [Department of Materials Science and Engineering, DTU Mechanical Engineering, Technical University of Denmark, 2800 Kgs. Lyngby (Denmark)

    2012-12-15

    Graphical abstract: Plot of cos {theta} versus temperature for metal and ceramic surfaces where cos {theta} rises linearly with increase in temperature. Highlights: Black-Right-Pointing-Pointer cos {theta} of olive oil on different surface materials rises linearly with increase in temperature. Black-Right-Pointing-Pointer Slopes are much higher for quasicrystalline and polymers than for ceramics. Black-Right-Pointing-Pointer Increase in surface roughness and surface flaws increases surface wettability. Black-Right-Pointing-Pointer Contact angle values gave information for grouping easy-clean polymers from other materials. Black-Right-Pointing-Pointer Contact angle measurements cannot directly estimate the cleanability of a surface. - Abstract: The main aim of the work was to investigate the wettability of different surface materials with vegetable oil (olive oil) over the temperature range of 25-200 Degree-Sign C to understand the differences in cleanability of different surfaces exposed to high temperatures in food processes. The different surface materials investigated include stainless steel (reference), PTFE (polytetrafluoroethylene), silicone, quasicrystalline (Al, Fe, Cr) and ceramic coatings: zirconium oxide (ZrO{sub 2}), zirconium nitride (ZrN) and titanium aluminum nitride (TiAlN). The ceramic coatings were deposited on stainless steel with two different levels of roughness. The cosine of the contact angle of olive oil on different surface materials rises linearly with increasing temperature. Among the materials analyzed, polymers (PTFE, silicone) gave the lowest cos {theta} values. Studies of the effect of roughness and surface flaws on wettability revealed that the cos {theta} values increases with increasing roughness and surface flaws. Correlation analysis indicates that the measured contact angle values gave useful information for grouping easy-clean polymer materials from the other materials; for the latter group, there is no direct relation between

  18. Improved wettability and adhesion of polylactic acid/chitosan coating for bio-based multilayer film development

    Energy Technology Data Exchange (ETDEWEB)

    Gartner, Hunter [School of Packaging, Michigan State University, East Lansing, Michigan (United States); Li, Yana [Mechanical Engineering College, Wuhan Polytechnic University (China); Almenar, Eva, E-mail: ealmenar@msu.edu [School of Packaging, Michigan State University, East Lansing, Michigan (United States)

    2015-03-30

    Graphical abstract: - Highlights: • Surface tension between PLA/CS blend solution and PLA film modified by MDI. • Better wettability between PLA/CS blend solution and PLA film by increasing MDI. • Increased breaking strength by increasing MDI due to the increased H-bonding. • Increased number of physical entanglements between PLA/CS coating and PLA film. • Development of a suitable bio-based multilayer film for food packaging applications. - Abstract: The objective of this study was to investigate the effect of methyldiphenyl diisocyanate (MDI) concentration (0, 0.2, 1, 2, and 3%) on the wettability and adhesion of blend solutions of poly(lactic acid) (PLA) and chitosan (CS) when coated on PLA film for development of a bio-based multi-layer film suitable for food packaging and other applications. Characterization was carried out by attenuated total reflectance infrared spectrometry (ATR-FTIR), contact angle (θ), mechanical adhesion pull-off testing, and scanning electron microscopy (SEM). The θ of the PLA/CS blend shifted to a lower value (41–35°) with increasing MDI concentration showing that the surface tension was modified between the PLA/CS blend solution and PLA film and better wettability was achieved. The increase in MDI also resulted in an increased breaking strength (228–303 kPa) due to the increased H-bonding resulting from the more urethane groups formed within the PLA/CS blend as shown by ATR-FTIR. The improved adhesion was also shown by the increased number of physical entanglements observed by SEM. It can be concluded that MDI can be used to improve wettability and adhesion between PLA/CS coating and PLA film.

  19. Understanding physical rock properties and their relation to fluid-rock interactions under supercritical conditions

    Science.gov (United States)

    Kummerow, Juliane; Raab, Siegfried; Meyer, Romain

    2017-04-01

    The electrical conductivity of rocks is, in addition to lithological factors (mineralogy, porosity) and physical parameters (temperature, pressure) sensitive to the nature of pore fluids (phase, salinity), and thus may be an indicative measure for fluid-rock interactions. Especially near the critical point, which is at 374.21° C and 22.12 MPa for pure water, the physico-chemical properties of aqueous fluids change dramatically and mass transfer and diffusion-controlled chemical reactivity are enhanced, which in turn leads to the formation of element depletion/ enrichment patterns or cause mineral dissolution. At the same time, the reduction of the dielectric constant of water promotes ion association and consequently mineral precipitation. All this cause changes in the electrical conductivity of geothermal fluids and may have considerable effects on the porosity and hydraulic properties of the rocks with which they are in contact. In order to study the impact of fluid-rock interactions on the physical properties of fluids and rocks in near- and supercritical geological settings in more detail, in the framework of the EU-funded project "IMAGE" (Integrated Methods for Advanced Geothermal Exploration) hydraulic and electrical properties of rock cores from different active and exhumed geothermal areas on Iceland were measured up to supercritical conditions (Tmax = 380° C, pfluid = 23 MPa) during long-term (2-3 weeks) flow-through experiments in an internally heated gas pressure vessel at a maximum confining pressure of 42 MPa. In a second flow-through facility both the intrinsic T-dependent electrical fluid properties as well as the effect of mineral dissolution/ precipitation on the fluid conductivity were measured for increasing temperatures in a range of 24 - 422° C at a constant fluid pressure of 31 MPa. Petro- and fluid physical measurements were supplemented by a number of additional tests, comprising microstructural investigations as well as the chemical

  20. Study of Wettability Effect on Pressure Drop and Flow Pattern of Two-Phase Flow in Rectangular Microchannel

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Chi Woong; Yu, Dong In; Kim, Moo Hwan [Pohang University of Science and Technology, Pohang (Korea, Republic of)

    2009-12-15

    Wettability is a critical parameter in micro-scale two-phase system. Several previous results indicate that wettability has influential affect on two-phase flow pattern in a microchannel. However, previous studies conducted using circular microtube, which was made by conventional fabrication techniques. Although most applications for micro thermal hydraulic system has used a rectangular microchannel, data for the rectangular microchannel is totally lack. In this study, a hydrophilic rectangular microchannel was fabricated using a photosensitive glass. And a hydrophobic rectangular microchannel was prepared using silanization of glass surfaces with OTS (octa-dethy1-trichloro-siliane). Experiments of two-phase flow in the hydrophilic and the hydrophobic rectangular microchannels were conducted using water and nitrogen gas. Visualization of two-phase flow pattern was carried out using a high-speed camera and a long distance microscope. Visualization results show that the wettability was important for two-phase flow pattern in rectangular microchannel. In addition, two-phase frictional pressure drop was highly related with flow patterns. Finally, Two-phase frictional pressure drop was analyzed with flow patterns.

  1. Programmable Shape Recovery Process of Water-Responsive Shape-Memory Poly(vinyl alcohol) by Wettability Contrast Strategy.

    Science.gov (United States)

    Fang, Zhiqiang; Kuang, Yudi; Zhou, Panpan; Ming, Siyi; Zhu, Penghui; Liu, Yu; Ning, Honglong; Chen, Gang

    2017-02-15

    Water-responsive shape-memory polymers (SMPs) are desirable for biomedical applications, but their limited shape recovery process is problematic. Herein, we demonstrate a shape-memory poly(vinyl alcohol) (SM-PVA) with programmable multistep shape recovery processes in water via a wettability contrast strategy. A hexamethyldisilazane (HMDS)-treated SiO2 nanoparticle layer with varying loading weights was rationally deposited onto the surface of SM-PVA, aiming to create surface-wettability contrast. The varying wettability led to different water adsorption behaviors of SM-PVA that could be well-described by the pseudo-first-order kinetic model. The results calculated from the kinetic model showed that both the pseudo-first order-adsorption rate constant and the saturated water absorption of SM-PVA demonstrated a declining trend as the loading weight of SiO2 increased, which laid the foundation for the local regulation of the water-responsive rate of SM-PVA. Finally, two proof-of-concept drug-delivery devices with diverse three-dimensional structures and actuations are presented based on the water-responsive SM-PVA with preprogrammed multistep shape recovery processes. We believe the programmable shape-memory behavior of water-responsive SM-PVA could highly extend its use in drug delivery, tissue engineering scaffolds, and smart implantable devices, etc.

  2. Boosting Gas Involved Reactions at Nanochannel Reactor with Joint Gas-Solid-Liquid Interfaces and Controlled Wettability.

    Science.gov (United States)

    Mi, Li; Yu, Jiachao; He, Fei; Jiang, Ling; Wu, Yafeng; Yang, Lijun; Han, Xiaofeng; Li, Ying; Liu, Anran; Wei, Wei; Zhang, Yuanjian; Tian, Ye; Liu, Songqin; Jiang, Lei

    2017-08-02

    The low solubility of gases in aqueous solution is the major kinetic limitation of reactions that involve gases. To address this challenge, we report a nanochannel reactor with joint gas-solid-liquid interfaces and controlled wettability. As a proof of concept, a porous anodic alumina (PAA) nanochannel membrane with different wettability is used for glucose oxidase (GOx) immobilization, which contacts with glucose aqueous solution on one side, while the other side gets in touch with the gas phase directly. Interestingly, it is observed that the O2 could participate in the enzymatic reaction directly from gas phase through the proposed nanochannels, and a hydrophobic interface is more favorable for the enzymatic reaction due to the rearrangement of GOx structure as well as the high gas adhesion. As a result, the catalytic efficiency of GOx in the proposed interface is increased up to 80-fold compared with that of the free state in traditional aqueous air-saturated electrolyte. This triphase interface with controlled wettability can be generally applied to immobilize enzymes or catalysts with gas substrates for high efficiency.

  3. Upper limb injuries associated with rock climbing.

    OpenAIRE

    Bannister, P; Foster, P

    1986-01-01

    Four cases of upper limb injuries secondary to rock-climbing or training for rock climbing are presented. All four cases had diagnosis and treatment delayed because of unawareness of the range of injuries seen in high grade rock climbing.

  4. They will rock you!

    CERN Multimedia

    Anaïs Schaeffer

    2013-01-01

    On 30 September, CERN will be the venue for one of the most prestigious events of the year: the concert for the Bosons&More event, the Organization’s celebration of the remarkable performance of the LHC and all its technical systems, as well as the recent fundamental discoveries. Topping the bill will be the Orchestre de la Suisse Romande, the CERN Choir, the Zürcher Sing-Akademie and the Alan Parsons Live Project rock group, who have joined forces to create an unforgettable evening’s entertainment.   The Orchestre de la Suisse Romande, directed by Maestro Neeme Järvi, artistic and musical director of the OSR. (Image: Grégory Maillot). >>> From the Orchestre de la Suisse Romande… Henk Swinnen, General Manager of the Orchestre de la Suisse Romande (OSR), answers some questions for the CERN Bulletin, just a few days before the event. How did this project come about? When CERN invited us to take part in the B...

  5. Shotgun cartridge rock breaker

    Energy Technology Data Exchange (ETDEWEB)

    Ruzzi, Peter L. (Eagan, NM); Morrell, Roger J. (Bloomington, MN)

    1995-01-01

    A rock breaker uses shotgun cartridges or other firearm ammunition as the explosive charge at the bottom of a drilled borehole. The breaker includes a heavy steel rod or bar, a gun with a firing chamber for the ammunition which screws onto the rod, a long firing pin running through a central passage in the rod, and a firing trigger mechanism at the external end of the bar which strikes the firing pin to fire the cartridge within the borehole. A tubular sleeve surround the main body of the rod and includes slits the end to allow it to expand. The rod has a conical taper at the internal end against which the end of the sleeve expands when the sleeve is forced along the rod toward the taper by a nut threaded onto the external end of the rod. As the sleeve end expands, it pushes against the borehole and holds the explosive gasses within, and also prevents the breaker from flying out of the borehole. The trigger mechanism includes a hammer with a slot and a hole for accepting a drawbar or drawpin which, when pulled by a long cord, allows the cartridge to be fired from a remote location.

  6. Adaptive wettability-enhanced surfaces ordered on molded etched substrates using shrink film

    Science.gov (United States)

    Jayadev, Shreshta; Pegan, Jonathan; Dyer, David; McLane, Jolie; Lim, Jessica; Khine, Michelle

    2013-01-01

    Superhydrophobic surfaces in nature exhibit desirable properties including self-cleaning, bacterial resistance, and flight efficiency. However, creating such intricate multi-scale features with conventional fabrication approaches is difficult, expensive, and not scalable. By patterning photoresist on pre-stressed shrink-wrap film, which contracts by 95% in surface area when heated, such features over large areas can be obtained easily. Photoresist serves as a dry etch mask to create complex and high-aspect ratio microstructures in the film. Using a double-shrink process, we introduce adaptive wettability-enhanced surfaces ordered on molded etched (AWESOME) substrates. We first create a mask out of the children’s toy ‘Shrinky-Dinks’ by printing dots using a laserjet printer. Heating this thermoplastic sheet causes the printed dots to shrink to a fraction of their original size. We then lithographically transfer the inverse pattern onto photoresist-coated shrink-wrap polyolefin film. The film is then plasma etched. After shrinking, the film serves as a high-aspect ratio mold for polydimethylsiloxane, creating a superhydrophobic surface with water contact angles >150° and sliding angles <10°. We pattern a microarray of ‘sticky’ spots with a dramatically different sliding angle compared to that of the superhydrophobic region, enabling microtiter-plate type assays without the need for a well plate.

  7. Diverse wettability of superoleophilicity and superoleophobicity for oil spill cleanup and recycling

    Science.gov (United States)

    Xu, Mengya; Wang, Gang; Zeng, Zhixiang; Chen, Junjun; Zhang, Xingyuan; Wang, Longsheng; Song, Weiguang; Xue, Qunji

    2017-12-01

    The frequent marine oil spill accidents in nowadays has aroused great attention all over the world. Lots of superwetting absorption materials with 2D or 3D structures are fabricated to efficiently remove oil spill, but the desorption of the absorbed oil is more difficult. Oil contaminants adhere on the surface will decline the performance and reusability of the absorption materials. Discarding or burning them will bring secondary pollution. Faced with these problems, we prepared an oil extractor integrated by a superhydrophobic-superoleophilic stainless steels wire mesh and a 3D porous cellulose sponge with superhydrophilicity-superoleophilicity in air and superoleophobicity in water. The oil extractor can in situ collect oil spill no matter on the water or under the water. More importantly, it is good at underwater oil desorption, which ensure the recovery and reuse of oil, and meanwhile avoid the materials being fouled by oils. More than 85.5% of crude oil could be successfully discharged only in 2 min when the oil-contaminated sponge was placed in water. The findings in this work not only put forward a new strategy for collection and reuse of various "oils", but also offer a facile method to achieve a combination of two kinds of materials with diverse wettability.

  8. Study of Wettability of Clayey Ceramic and Fluorescent Lamp Glass Waste Powders

    Science.gov (United States)

    Morais, Alline Sardinha Cordeiro; Monteiro, Sergio Neves; Ribeiro, Sebastião; Sardinha, Leonardo Carneiro; Vieira, Carlos Maurício Fontes

    The glass tube of spent fluorescent lamps is contaminated with mercury, which might be a serious hazard in the case of conventional recycling by melting with other glasses. A possible solution could be its incorporation into a clay body to fabricate common fired ceramics such as bricks and tiles. The objective of this work is to characterize a type of fluorescent lamp glass waste to be incorporated into a clayey ceramic. The characterization was performed in terms of wettability tests to evaluate the interaction between the surface of the clayey ceramic and glass waste as a function of the firing temperature. The results showed that the contact angle decreased with increasing temperature, reaching a value of 79°, at a temperature of 1100°C, but not sufficient to completely wet the ceramic. However, compatible chemical composition and reduction of porosity by the flow of soft glass waste between the clay particles favor the consolidation of the ceramics structure above 900°C.

  9. Etchant wettability in bulk micromachining of Si by metal-assisted chemical etching

    Science.gov (United States)

    Yoon, Sung-Soo; Lee, Yeong Bahl; Khang, Dahl-Young

    2016-05-01

    Wet bulk micromachining of Si by metal-assisted chemical etching (MaCE) has successfully been demonstrated. Based on the mechanism of defective etching results from Ag and Au metal catalyst experiments, the wettability of etchant solution, in addition to metal type, has been found to have profound effect on the etching process. Addition of low surface tension co-solvent, ethanol in this work, into conventional etchant formulation has enabled complete wetting of etchant on surface, which prevents hydrogen bubble attachment on sample surface during the etching. The complete elimination of bubble attachment guarantees very uniform etch rate on all over the sample surface, and thus prevents premature fragmentation/rupture of catalyst metal layer. Under the optimized etching conditions, the MaCE could be done for up to 12 h without any noticeable film rupture and thus etching defects. Thanks to very smooth surface of the etched patterns, conformal contact and direct bonding of elastomer on such surface has been easily accomplished. The method demonstrated here can pave the way for application of simple, low-cost MaCE process in the bulk micromachining of Si for various applications.

  10. Controlled preparation of titania nanofilm by a template of polydopamine film and its reversible wettability

    Energy Technology Data Exchange (ETDEWEB)

    Zheng Longzhen, E-mail: zlz@ecjtu.jx.cn; Liu Qiang; Xiong Leyan; Li Yindi; Han Kui; Liu Wen; Tao Kun; Yang Shaoming; Xia Jian

    2012-01-31

    Titanium oxide (TiO{sub 2}) nanofilm was prepared by a simple method of sol-gel deposition on the glass substrate, which was pre-modified with a polydopamine (PDA) film. The as-prepared TiO{sub 2} nanofilm was analyzed by X-ray diffraction, scanning electron microscopy, and atomic force microscopy. The thickness of TiO{sub 2} film can be controlled by the thickness of PDA film, which was dependent on the polymerization time. The mechanism of wettability conversion on TiO{sub 2} film was investigated by means of contact angle measurements in different experimental conditions. The results demonstrated that humidity was the major factor for converting the hydrophobic surface of TiO{sub 2} film into hydrophilic surface under ultra-violet (UV) irradiation. And atmospheric oxygen played dominant role in reconverting the hydrophilic surface of TiO{sub 2} film into hydrophobic surface when it was stored in the dark. The TiO{sub 2} nanofilm showed reversible hydrophobic/hydrophilic conversion in the condition of alternating between UV irradiation and storage in the dark.

  11. Capillary flow-driven microfluidic device with wettability gradient and sedimentation effects for blood plasma separation

    Science.gov (United States)

    Maria, M. Sneha; Rakesh, P. E.; Chandra, T. S.; Sen, A. K.

    2017-01-01

    We report a capillary flow-driven microfluidic device for blood-plasma separation that comprises a cylindrical well between a pair of bottom and top channels. Exposure of the well to oxygen-plasma creates wettability gradient on its inner surface with its ends hydrophilic and middle portion hydrophobic. Due to capillary action, sample blood self-infuses into bottom channel and rises up the well. Separation of plasma occurs at the hydrophobic patch due to formation of a ‘self-built-in filter’ and sedimentation. Capillary velocity is predicted using a model and validated using experimental data. Sedimentation of RBCs is explained using modified Steinour’s model and correlation between settling velocity and liquid concentration is found. Variation of contact angle on inner surface of the well is characterized and effects of well diameter and height and dilution ratio on plasma separation rate are investigated. With a well of 1.0 mm diameter and 4.0 mm height, 2.0 μl of plasma was obtained (from <10 μl whole blood) in 15 min with a purification efficiency of 99.9%. Detection of glucose was demonstrated with the plasma obtained. Wetting property of channels was maintained by storing in DI water under vacuum and performance of the device was found to be unaffected over three weeks. PMID:28256564

  12. Wettability and morphology of the leaf surface in cashew tree from the Amazon, Northern Brazil

    Directory of Open Access Journals (Sweden)

    Glenda Quaresma Ramos

    2016-10-01

    Full Text Available Leaves surfaces, which represent an interface with plants and the environment, have several structures with specific functions. Some foliar properties, including wettability and mechanical containment, are inferred in terms of cellular adaptation and the presence or absence of cuticular wax. Various morphological parameters, ranging from macro- to nano scales, are analyzed and contribute to the study of taxonomy, pharmacognosy, and ecology of plants. The aim of this paper was to analyze the effect and influence of epicuticular wax granules on the hydrophobicity of Anacardium occidentale L. leaf surfaces. Leaf specimens were directly examined with an environmental scanning electron microscope without metal coating. Images revealed epidermis ornament, stomata type, was, and trichomes. Static contact angle between water and the surface was also measured on both sides. On the adaxial side, an angle of 104.09° ± 0.95° was found, suggesting that adaxial surface is hydrophobic. On the abaxial side, the angle was 62.20° ± 1.60°, which indicates a hydrophilic nature, probably because of the greater amount of epicuticular wax on the adaxial leaf surface. The present investigation provided an important contribution to morphological and ultrastructural characterization of leaves of cashew tree, which is a plant of great medicinal and economic importance.

  13. Wettability study of lead free solder paste and its effect towards multiple reflow

    Directory of Open Access Journals (Sweden)

    Idris Siti Rabiatull Aisha

    2016-01-01

    Full Text Available Nowadays, wafer bumping using solder paste has come into focus as it provides a low cost method. However, since the industries are moving towards lead-free electronic packaging, a new type of no-clean flux was produced specifically for lead-free solder paste. Therefore, this study is used to evaluate the wettability of two different types of no-clean flux onto copper substrate. Besides, its effect towards multiple reflow was also studied. Reflow soldering was conducted for both types of solder paste that contained different type of no-clean flux for up to double reflow. Two different reflow profile was used. The results showed that the Flux A exhibit better soldering performance after first and second reflow soldering. In addition, type of intermetallic compound (IMC found after first reflow remain the same even after second reflow which was Cu-Sn based. This is shows that Flux A manage to control the diffusion process which will finally leads to a better solder joint performance. Nevertheless, mechanical testing should be carried out in order to evaluate the solder joint strength.

  14. Adhesion forces in liquid media: effect of surface topography and wettability.

    Science.gov (United States)

    Serro, A P; Colaço, R; Saramago, B

    2008-09-15

    This work was motivated by the unexpected values of adhesion forces measured between an atomic force microscopy tip and the hydrophobic surface of ultra-high-molecular-weight polyethylene. Two types of samples with different roughness but similar wettability were tested. Adhesion forces of similar magnitude were obtained in air and in polar liquids (water and Hank's Balanced Salt Solution, a saline solution) with the rougher sample. In contrast, the adhesion forces measured on the smoother sample in air were much higher than those measured in water or in the aqueous solution. Those experimental results suggested the presence of nanobubbles at the interface between the rough sample and the polar liquids. The existence of the nanobubbles was further confirmed by the images of the interface obtained in noncontact tapping mode. The adhesion forces measured in a nonpolar liquid (hexadecane) were small and of the same order of magnitude for both samples and their values were in good agreement with the predictions of the London-Hamaker approach for the van der Waals interactions. Finally, we correlate the appearance of nanobubbles with surface topography. The conclusion of this work is that adhesion forces measured in aqueous media may be strongly affected by the presence of nanobubbles if the surface presents topographical accidents.

  15. Effects of aperture variability and wettability on immiscible displacement in fractures

    Science.gov (United States)

    Yang, Zhibing; Méheust, Yves; Neuweiler, Insa

    2017-04-01

    Fluid-fluid displacement in porous and fractured media is an important process. Understanding and controlling this process is key to many practical applications, such as hydrocarbon recovery, geological storage of CO2, groundwater remediation, etc. Here, we numerically study fluid-fluid displacement in rough-walled fractures. We focus on the combined effect of wettability and fracture surface topography on displacement patterns and interface growth. We develop a novel numerical model to simulate dynamic fluid invasion under the influence of capillary and viscous forces. The capillary force is calculated using the two principal curvatures (aperture-induced curvature and in-plane curvature) at the fluid-fluid interface, and the viscous force is taken into account by solving the fluid pressure distribution. The aperture field of a fracture is represented by a spatially correlated random field, which is described by a power spectrum for the fracture wall topography and a cutoff wave-length. We numerically produce displacement patterns ranging from stable displacement, capillary fingering, and viscous fingering, as well as the transitions between them. We show that both reducing the aperture variability and increasing the contact angle (from drainage to weak imbibition) stabilize the displacement due to the influence of the in-plane curvature, an effect analogous to that of the cooperative pore filling in porous media. Implications of these results will be discussed.

  16. The relationship study between texture vibrating plate dynamic wettability and elastic wave scattering

    Science.gov (United States)

    Xu, Jing; Li, Bin; Zhou, Chuanping; Xiao, Jing; Ni, Jing

    2017-07-01

    An experimental investigation of wetting behavior of liquid droplet on texture vibrating substrate and the theoretical calculations of elastic wave scattering with two holes which based on the elastodynamics, employing complex functions are investigated to study the relationship between texture vibrating plate dynamic wettability and elastic wave scattering. Experimental results show the dynamic behavior of droplet was unstable. In 0 to π/2 cycle, droplet appeared the waveform with front steep and rear gentle along the flow direction. In π/2 to π cycle, droplet appeared slightly periodic oscillation and accompanied by a certain ripple. Based on the dynamic wetting phenomenon in a single cycle, the influence of elastic wave scattering on wetting property are analyzed. Analysis has shown that the stress concentration is caused by complex elastic wave scattering. The more concentrated the stress, the more concentrated the elastic wave energy. Compared with the single hole, the variations of dynamic stress concentration factors for two holes are complex due to the influence of interaction between two holes. Droplet emerge movement is response to the local vibration. The vibration spread in elastic plate at a time of strain, this elastic force cause droplet displacement and vibration, and accompanied with energy transfer.

  17. Effect of Hydrofluoric Acid Etching Time on Titanium Topography, Chemistry, Wettability, and Cell Adhesion.

    Directory of Open Access Journals (Sweden)

    R Zahran

    Full Text Available Titanium implant surface etching has proven an effective method to enhance cell attachment. Despite the frequent use of hydrofluoric (HF acid, many questions remain unresolved, including the optimal etching time and its effect on surface and biological properties. The objective of this study was to investigate the effect of HF acid etching time on Ti topography, surface chemistry, wettability, and cell adhesion. These data are useful to design improved acid treatment and obtain an improved cell response. The surface topography, chemistry, dynamic wetting, and cell adhesiveness of polished Ti surfaces were evaluated after treatment with HF acid solution for 0, 2; 3, 5, 7, or 10 min, revealing a time-dependent effect of HF acid on their topography, chemistry, and wetting. Roughness and wetting increased with longer etching time except at 10 min, when roughness increased but wetness decreased. Skewness became negative after etching and kurtosis tended to 3 with longer etching time. Highest cell adhesion was achieved after 5-7 min of etching time. Wetting and cell adhesion were reduced on the highly rough surfaces obtained after 10-min etching time.

  18. Effect of liquid immersion of PEDOT: PSS-coated polyester fabric on surface resistance and wettability

    Science.gov (United States)

    Getnet Tadesse, Melkie; Loghin, Carmen; Chen, Yan; Wang, Lichuan; Catalin, Dumitras; Nierstrasz, Vincent

    2017-06-01

    Coating of textile fabrics with poly (3, 4-ethylenedioxythiophene): poly (styrene sulfonate) (PEDOT:PSS) is one of the methods used for obtaining functional or smart applications. In this work, we prepared PEDOT:PSS polymer with certain additives such as polyethylene glycol, methanol (MeOH), and ethylene glycol on polyester fabric substrates by a simple immersion process. Surface resistance was measured and analyzed with analysis of variance to determine the coating parameters at 95% confidence level. Fourier transform infrared (FTIR) analysis and scanning electron microscopy (SEM) study of the samples were performed. Contact angle and washing fastness measurements were conducted, to observe the wettability and washing fastness of the samples, respectively. Surface resistance values were decreased by a factor of 100, due to conductive enhancers. As the immersion time and temperature condition varies, surface resistance showed no difference, statistically. FTIR analysis supports the idea that the mechanism responsible for the conductivity enhancement is the partial replacement of PSS from PEDOT chain by forming a hydrogen bond with hydroxyl ion (OH) of the conductive enhancers. A SEM images showed that PEDOT:PSS is well distributed to the surface of the fabrics. Contact angle measurements showed morphology change in the samples. The conductivity was reasonably stable after 10 washing cycles. Altogether, an effective simple immersion of coated polyester fabric is presented to achieve functional textiles that offer a broad range of possible applications.

  19. The Effect of Wettability on the Dynamical Behaviors of Single-Walled Carbon Nanotube

    Directory of Open Access Journals (Sweden)

    Yan Yan

    2015-01-01

    Full Text Available The dynamical behaviors of single-walled carbon nanotube (SWCNT with the internal and external wettability are studied based on a multiple flexible shell model in the paper. The SWCNT-water system comprises five constituent parts, that is, the SWCNT, the absorbed inner and outer layers of water molecules, the water in the center of the SWCNT, and the water surrounding the absorbed outer water layer. Here we consider the absorbed water layers as infinitesimally thin shells, which interact with the nanotube via a continuum Lennard-Jones potential, and the water in the center of the SWCNT and the counterpart surrounding the absorbed outer water layer as the potential flow. It is found that the interactions of SWCNT and the water layer are responsible for an upshift in the frequency of the SWCNT and the total upshift is approximately the sum of the two corresponding upshifts. The vdW interactions also cause the increase of the frequency of internal and external water shells. We hope that the paper can offer a new modeling approach to determine whether carbon nanotubes have adsorbed fluids inside their pores and could be used for detecting changes in their filling state.

  20. Maximum spreading of liquid drop on various substrates with different wettabilities

    Science.gov (United States)

    Choudhury, Raihan; Choi, Junho; Yang, Sangsun; Kim, Yong-Jin; Lee, Donggeun

    2017-09-01

    This paper describes a novel model developed for a priori prediction of the maximal spread of a liquid drop on a surface. As a first step, a series of experiments were conducted under precise control of the initial drop diameter, its falling height, roughness, and wettability of dry surfaces. The transient liquid spreading was recorded by a high-speed camera to obtain its maximum spreading under various conditions. Eight preexisting models were tested for accurate prediction of the maximum spread; however, most of the model predictions were not satisfactory except one, in comparison with our experimental data. A comparative scaling analysis of the literature models was conducted to elucidate the condition-dependent prediction characteristics of the models. The conditioned bias in the predictions was mainly attributed to the inappropriate formulations of viscous dissipation or interfacial energy of liquid on the surface. Hence, a novel model based on energy balance during liquid impact was developed to overcome the limitations of the previous models. As a result, the present model was quite successful in predicting the liquid spread in all the conditions.

  1. Open Fluidics: A Cell Culture Flow System Developed Over Wettability Contrast-Based Chips.

    Science.gov (United States)

    Oliveira, Nuno M; Reis, Rui L; Mano, João F

    2017-10-16

    Biological tissues are recurrently exposed to several dynamic mechanical forces that influence cell behavior. On this work, the focus is on the shear stress forces induced by fluid flow. The study of flow-induced effects on cells leads to important advances in cardiovascular, cancer, stem cell, and bone biology understanding. These studies are performed using cell culture flow (CCF) systems, mainly parallel plate flow chambers (PPFC), and microfluidic systems. Here, it is proposed an original CCF system based on the open fluidics concept. The system is developed using a planar superhydrophobic platform with hydrophilic paths. The paths work as channels to drive cell culture medium flows without using walls for liquid confinement. The liquid streams are controlled just based on the wettability contrast. To validate the concept, the effect of the shear stress stimulus in the osteogenic differentiation of C2C12 myoblast cells is studied. Combining bone morphogenic protein (specifically BMP-2) stimulation with this mechanical stimulus, a synergistic effect is found on osteoblast differentiation. This effect is confirmed by the enhancement of alkaline phosphatase activity, a well-known early marker of osteogenic differentiation. The suggested CCF system combines characteristics and advantages of both the PPFC and microfluidic systems. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Dynamic rock fragmentation: thresholds for long runout rock avalanches

    Directory of Open Access Journals (Sweden)

    E.T. Bowman

    2014-10-01

    Full Text Available The dynamic fragmentation of rock within rock avalanches is examined using the fragmentation concepts introduced by Grady and co-workers. The analyses use typical material values for weak chalk and limestone in order to determine theoretical strain rate thresholds for dynamic fragmentation and resulting fragment sizes. These are found to compare favourably with data obtained from field observations of long runout rock avalanches and chalk cliff collapses in spite of the simplicity of the approach used. The results provide insight as to the energy requirements to develop long runout behaviour and hence may help to explain the observed similarities between large rock avalanches and much smaller scale chalk cliff collapses as seen in Europe.

  3. Multiverso: Rock'n'Astronomy

    Science.gov (United States)

    Caballero, J. A.

    2012-05-01

    In the last few years, there have been several projects involving astronomy and classical music. But have a rock band ever appeared at a science conference or an astronomer at a rock concert? We present a project, Multiverso, in which we mix rock and astronomy, together with poetry and video art (Caballero, 2010). The project started in late 2009 and has already reached tens of thousands people in Spain through the release of an album, several concert-talks, television, radio, newspapers and the internet.

  4. Classification scheme for sedimentary and igneous rocks in Gale crater, Mars

    Science.gov (United States)

    Mangold, N.; Schmidt, M. E.; Fisk, M. R.; Forni, O.; McLennan, S. M.; Ming, D. W.; Sautter, V.; Sumner, D.; Williams, A. J.; Clegg, S. M.; Cousin, A.; Gasnault, O.; Gellert, R.; Grotzinger, J. P.; Wiens, R. C.

    2017-03-01

    Rocks analyzed by the Curiosity rover in Gale crater include a variety of clastic sedimentary rocks and igneous float rocks transported by fluvial and impact processes. To facilitate the discussion of the range of lithologies, we present in this article a petrological classification framework adapting terrestrial classification schemes to Mars compositions (such as Fe abundances typically higher than for comparable lithologies on Earth), to specific Curiosity observations (such as common alkali-rich rocks), and to the capabilities of the rover instruments. Mineralogy was acquired only locally for a few drilled rocks, and so it does not suffice as a systematic classification tool, in contrast to classical terrestrial rock classification. The core of this classification involves (1) the characterization of rock texture as sedimentary, igneous or undefined according to grain/crystal sizes and shapes using imaging from the ChemCam Remote Micro-Imager (RMI), Mars Hand Lens Imager (MAHLI) and Mastcam instruments, and (2) the assignment of geochemical modifiers based on the abundances of Fe, Si, alkali, and S determined by the Alpha Particle X-ray Spectrometer (APXS) and ChemCam instruments. The aims are to help understand Gale crater geology by highlighting the various categories of rocks analyzed by the rover. Several implications are proposed from the cross-comparisons of rocks of various texture and composition, for instance between in place outcrops and float rocks. All outcrops analyzed by the rover are sedimentary; no igneous outcrops have been observed. However, some igneous rocks are clasts in conglomerates, suggesting that part of them are derived from the crater rim. The compositions of in-place sedimentary rocks contrast significantly with the compositions of igneous float rocks. While some of the differences between sedimentary rocks and igneous floats may be related to physical sorting and diagenesis of the sediments, some of the sedimentary rocks (e

  5. Evolution of wettability in terms of petroleum and petroleum fractions adsorption. An approach by the Wilhelmy method; Evolution de la mouillabilite en fonction de l`adsorption du petrole et de ses fractions. Approche par la methode des angles de contact dynamiques

    Energy Technology Data Exchange (ETDEWEB)

    Mattos Saliba, A.

    1996-12-06

    Reservoir wettability is very important to petroleum recovery by waterflooding and other processes. It is a key parameter controlling multiphase flow and fluids distribution in a porous medium. Nevertheless, the original water-wetness can be modified by the petroleum`s natural surfactants (asphaltenes and resins) adsorption onto the rock surface. This adsorption may reduce petroleum recovery. In this study, the adsorption of model molecules (pyridine and benzo-quinoline), of rude oil and of its heavier fractions (asphaltenes and resins) has been investigated in terms of wettability alteration for initially water-wet surfaces (glass or quartz). In this case, the dynamic Wilhelmy plate technique provides quantitative values of wetting preference to either oil or water. The results show that, at ambient conditions, adsorption depends on concentration, adsorbent/adsorbate interaction time, pH, solvent type, substrate surface, brine concentration and environment liquid phase (water or oil). However, the initial water film on the surface does not strongly influence this phenomena. (author) 222 refs.

  6. Chemical methods of rock analysis

    National Research Council Canada - National Science Library

    Jeffery, P. G; Hutchison, D

    1981-01-01

    A practical guide to the methods in general use for the complete analysis of silicate rock material and for the determination of all those elements present in major, minor or trace amounts in silicate...

  7. Defending dreamer’s rock

    OpenAIRE

    Beck, Günter U.

    2007-01-01

    Defending dreamer’s rock : Geschichte, Geschichtsbewusstsein und Geschichtskultur im Native drama der USA und Kanadas. - Trier : WVT Wiss. Verl. Trier, 2007. - 445 S. - (CDE - Studies ; 14). - Zugl.: Augsburg, Univ., Diss., 2006

  8. Beach rock from Goa Coast

    Digital Repository Service at National Institute of Oceanography (India)

    Setty, M.G.A.P.; Wagle, B.G.

    constituents of beach rock found along Goa coast is dealt with in detail. While discussing the various views on its origin, it is emphasized that the process of cementation is chiefly controlled by ground water evaporation, inorganic precipitation and optimum...

  9. The Chronology of Rock Art

    Indian Academy of Sciences (India)

    Such phases are tentatively ascribed to different archaeological cultures on the basis of the contextual availability, stylistic similarities and so on. Ethnographic analogies are also attempted in the dating of rock art .

  10. Microscopic surface wettability electrochemical characterization of tight sandstone with infrared spectra testing

    Science.gov (United States)

    Song, L.; Ning, Z. F.; Li, N.; Zhang, B.; Ding, G. Y.

    2017-08-01

    The distribution of charge density on the surface of microscopic tight oil is studied by using Stern double electric layer theory, and the mathematical flow model of polar fluid with micro powers in tight oil reservoir is established. The Fourier transform infrared (FTIR) were used to investigate the interaction of rock surface functional groups with fluids. The results show that: (1) When the external fluid of the polar group passes through the dense micro-nano pore, it will form an electric double layer on the surface of the rock, there will be a certain thickness of the liquid membrane, the fluid migration has a certain Of the electrical viscosity effect, will have a certain flow resistance. (2) The Fourier transform infrared spectroscopy of the Chang 7 tight reservoir rock samples exists and distributes different kinds of peaks. The left peak trend determines the presence of hydroxyl groups. The four fronts and types of the right side can be used to obtain that calcium carbonate CO3 2- exists. (3) There are CO3 2- and hydroxyl functional minerals in the Chang 7 tight sandstone samples. It is consistent with the basic mineral analysis measured by X-ray diffraction. When the external fluid affects the rock surface, the surface will occur in the physical van der Waals force and chemical bond interaction, so it will affect the flow of water on the surface.

  11. Proceedings of the scientific visit on crystalline rock repository development.

    Energy Technology Data Exchange (ETDEWEB)

    Mariner, Paul E.; Hardin, Ernest L.; Miksova, Jitka [RAWRA, Czech Republic

    2013-02-01

    A scientific visit on Crystalline Rock Repository Development was held in the Czech Republic on September 24-27, 2012. The visit was hosted by the Czech Radioactive Waste Repository Authority (RAWRA), co-hosted by Sandia National Laboratories (SNL), and supported by the International Atomic Energy Agency (IAEA). The purpose of the visit was to promote technical information exchange between participants from countries engaged in the investigation and exploration of crystalline rock for the eventual construction of nuclear waste repositories. The visit was designed especially for participants of countries that have recently commenced (or recommenced) national repository programmes in crystalline host rock formations. Discussion topics included repository programme development, site screening and selection, site characterization, disposal concepts in crystalline host rock, regulatory frameworks, and safety assessment methodology. Interest was surveyed in establishing a %E2%80%9Cclub,%E2%80%9D the mission of which would be to identify and address the various technical challenges that confront the disposal of radioactive waste in crystalline rock environments. The idea of a second scientific visit to be held one year later in another host country received popular support. The visit concluded with a trip to the countryside south of Prague where participants were treated to a tour of the laboratory and underground facilities of the Josef Regional Underground Research Centre.

  12. ROCK PROPERTIES MODEL ANALYSIS MODEL REPORT

    Energy Technology Data Exchange (ETDEWEB)

    Clinton Lum

    2002-02-04

    ) Development of geostatistical simulations of porosity; (4) Generation of derivative property models via linear coregionalization with porosity; (5) Post-processing of the simulated models to impart desired secondary geologic attributes and to create summary and uncertainty models; and (6) Conversion of the models into real-world coordinates. The conversion to real world coordinates is performed as part of the integration of the RPM into the Integrated Site Model (ISM) 3.1; this activity is not part of the current analysis. The ISM provides a consistent volumetric portrayal of the rock layers, rock properties, and mineralogy of the Yucca Mountain site and consists of three components: (1) Geologic Framework Model (GFM); (2) RPM, which is the subject of this AMR; and (3) Mineralogic Model. The interrelationship of the three components of the ISM and their interface with downstream uses are illustrated in Figure 1. Figure 2 shows the geographic boundaries of the RPM and other component models of the ISM.

  13. Emakumeak Punk-Rock taldeetan

    OpenAIRE

    Altuna Etxeberria, Maialen

    2010-01-01

    Ikerketa honen helburua emakumeek punk-rock taldeetan izan duten parte hartzea aztertzea da. Lanaren abiapuntua galdera bat izan da: zergatik daude hain emakume gutxi punk-rock musika eremuko taldeetan parte hartzen eta are gutxiago instrumentuak jotzen? Genero sistemak parte hartze urri horretan izan duen eragina aztertzeko lehenik eta behin musika herrikoia eta generoaren inguruan egindako lanetara hurbilpena egin da. Bestalde, punk-rockak izan duen ibilbidea aztertu da. Behin gaia kok...

  14. Thermally induced rock stress increment and rock reinforcement response

    Energy Technology Data Exchange (ETDEWEB)

    Hakala, M. [KMS Hakala Oy, Nokia (Finland); Stroem, J.; Nujiten, G.; Uotinen, L. [Rockplan, Helsinki (Finland); Siren, T.; Suikkanen, J.

    2014-07-15

    This report describes a detailed study of the effect of thermal heating by the spent nuclear fuel containers on the in situ rock stress, any potential rock failure, and associated rock reinforcement strategies for the Olkiluoto underground repository. The modelling approach and input data are presented together repository layout diagrams. The numerical codes used to establish the effects of heating on the in situ stress field are outlined, together with the rock mass parameters, in situ stress values, radiogenic temperatures and reinforcement structures. This is followed by a study of the temperature and stress evolution during the repository's operational period and the effect of the heating on the reinforcement structures. It is found that, during excavation, the maximum principal stress is concentrated at the transition areas where the profile changes and that, due to the heating from the deposition of spent nuclear fuel, the maximum principal stress rises significantly in the tunnel arch area of NW/SW oriented central tunnels. However, it is predicted that the rock's crack damage (CD, short term strength) value of 99 MPa will not be exceeded anywhere within the model. Loads onto the reinforcement structures will come from damaged and loosened rock which is assumed in the modelling as a free rock wedge - but this is very much a worst case scenario because there is no guarantee that rock cracking would form a free rock block. The structural capacity of the reinforcement structures is described and it is predicted that the current quantity of the rock reinforcement is strong enough to provide a stable tunnel opening during the peak of the long term stress state, with damage predicted on the sprayed concrete liner. However, the long term stability and safety can be improved through the implementation of the principles of the Observational Method. The effect of ventilation is also considered and an additional study of the radiogenic heating effect on the

  15. Our world was rocked.

    Science.gov (United States)

    Hironaka, L Kari; Trozzi, Maria; Augustyn, Marilyn

    2010-06-01

    Nicole is a beautiful 14-month wide-eyed girl who presents for routine health care maintenance in your office. Since her 9 month visit, her weight has fallen from the 25th percentile to significantly less than the 5th percentile. Her height has dropped from the 10th percentile to slightly less than the 5th percentile, while her head circumference has remained at about the 25th percentile. Her language, motor, cognitive, and social development are normal. She is 2 months late for this visit as her family has recently had significant family loss because of the earthquake in Haiti. When you take a feeding history, she seems to eat age-appropriate foods--macaroni, chicken pieces--but her mother notes that she tends to be restless and fidgety while eating and will no longer sit still in her mother's lap while she feeds her. Her stools tend to be frequent, with particles of food seen. Urine is normal. There are no symptoms of respiratory or neurological disease, and her review of systems is otherwise negative. She has been a healthy child and this is the first time they have fallen behind in routine health care maintenance visits. Her medical history is entirely unremarkable. She was born at term, weighing 3.5 kg, without any perinatal complications. The family has lived in the United States for the last 10 years. Mother recalls that there were other children in her family who were deemed small as young children but who caught up later in childhood. Mother describes a history of increased sadness and worry in the last 2 months. They receive phone calls from family in Haiti several times per week and she admits to being upset during and after these calls. When asked how the event has impacted her family, she states, "It has rocked our entire world but Nicole is just a baby who won't eat!" Parents are married, and there is no history of abuse or violence in the household. Her physical examination is essentially normal. Her anterior fontanelle is still open, roughly 2 cm

  16. Impact of the extreme 2009 wildfire Victoria the wettability of naturally highly water repellent soils

    Science.gov (United States)

    Doerr, Stefan H.; Shakesby, Richard A.; Sheridan, Gary J.; Lane, Patrick Nj; Smith, Hugh G.; Bell, Tina; Blake, William H.

    2010-05-01

    The recent catastrophic wildfires near Melbourne, which peaked on Feb. 7 2009, burned ca 400,000 ha and caused the tragic loss of 173 people. They occurred during unprecedented extreme fire weather where dry northerly winds gusting up to 100 km/h coincided with the highest temperatures ever recorded in this region. These conditions, combined with the very high biomass of mature eucalypt forests, very low fuel moisture conditions and steep slopes, generated extreme burning conditions. A rapid response project was launched under the NERC Urgency Scheme aimed at determining the effects of this extreme event on soil properties. Three replicate sites each were sampled for extremely high burn severity, high burn severity and unburnt control terrain, within mature mixed-species eucalypt forests near Marysville in April 2009. Ash and surface soil (0-2.5 cm and 2.5-5 cm) were collected at 20 sample grid points at each site. Here we report on outcomes from Water Drop Penetration Time (WDPT) tests carried out on soil samples to determine the impact of this extreme event on the wettability of a naturally highly water repellent soil. Field assessment suggested that the impact of this extreme wildfire on the soil was less than might be supposed given the extreme burn severity (indicated by the complete elimination of the ground vegetation). This was confirmed by the laboratory results. No major difference in WDPT was detected between (i) burned and control samples, and (ii) between surface and subsurface WDPT patterns, indicating that soil temperatures in the top 0-2.5 cm did not exceed ~200° C. Seedling germination in burned soil was reduced by at least 2/3 compared to the control samples, however, this reduction is indicative an only modest heat input into the soil. The limited heat input into the soil stands in stark contrast to the extreme burn severity (based on vegetation destruction parameters). We speculate that limited soil heating resulted perhaps from the unusually

  17. Membrane fouling and wetting in membrane distillation and their mitigation by novel membranes with special wettability.

    Science.gov (United States)

    Wang, Zhangxin; Lin, Shihong

    2017-04-01

    Membrane distillation (MD) has been identified as a promising technology to desalinate the hypersaline wastewaters from fracking and other industries. However, conventional hydrophobic MD membranes are highly susceptible to fouling and/or wetting by the hydrophobic and/or amphiphilic constituents in these wastewaters of complex compositions. This study systematically investigates the impact of the surface wetting properties on the membrane wetting and/or fouling behaviors in MD. Specifically, we compare the wetting and fouling resistance of three types of membranes of different wetting properties, including hydrophobic and omniphobic membranes as well as composite membranes with a hydrophobic substrate and a superhydrophilic top surface. We challenged the MD membranes with hypersaline feed solutions that contained a relatively high concentration of crude oil with and without added synthetic surfactants, Triton X-100. We found that the composite membranes with superhydrophilic top surface were robustly resistant to oil fouling in the absence of Triton X-100, but were subject to pore wetting in the presence of Triton X-100. On the other hand, the omniphobic membranes were easily fouled by oil-in-water emulsion without Triton X-100, but successfully sustained stable MD performance with Triton X-100 stabilized oil-in-water emulsion as the feed solution. In contrast, the conventional hydrophobic membranes failed readily regardless whether Triton X-100 was present, although via different mechanisms. These findings are corroborated by contact angle measures as well as oil-probe force spectroscopy. This study provides a holistic picture regarding how a hydrophobic membrane fails in MD and how we can leverage membranes with special wettability to prevent membrane failure in MD operations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Topography, Wettability, and Electrostatic Charge Consist Major Surface Properties of Intraocular Lenses.

    Science.gov (United States)

    Yang, Na; Zhang, Dong-Dong; Li, Xue-Dong; Lu, Yuan-Yuan; Qiu, Xiao-Hui; Zhang, Jin-Song; Kong, Jun

    2017-02-01

    To quantify potential relevant factors that affect the biocompatibility and functionality of intraocular lenses (IOLs) by analyzing the surface properties of various IOL materials. Eleven IOL models with the same dioptric power made by different manufacturers were studied. The IOLs were made of poly-methyl methacrylate (PMMA), hydrophobic acrylate, hydrophilic acrylate, and silicone. The IOL surface topography was evaluated using atomic force microscopy (AFM). Surface potential was measured by electric force microscopy (EFM). Surface wettability was assessed with the water contact angle using the sessile drop method. The PMMA IOLs had statistically significant surface irregularities with the highest surface roughness values while the silicone and hydrophilic acrylic IOLs had the lowest values. Surface potentials on IOLs revealed that all IOL models made of PMMA had positive charge. The hydrophobic acrylic IOL had a significantly higher positive charge (6.2v ± 0.1v), while the hydrophobic acrylic with blue blocker exhibited negative charge. Negative charge was also observed on hydrophilic acrylic IOLs (-72mv ± 5mv) and silicone IOLs (-5.06v ± 0.02v). Contact angle values of PMMA IOLs ranged from 49° to 64°. Heparin modification resulted in significant reduction of the contact angle value. IOL models made of hydrophobic acrylate had contact angle values between 78° and 89°. The silicone IOL appeared to be significantly hydrophobic with the highest mean value of 107°. The variance of the parameters of surface roughness, contact angle, and electrostatic charge on the surfaces of PMMA, hydrophobic acrylic, hydrophilic acrylic, and silicone IOLs is useful to the interpretation of the differences in clinical behaviors of these materials. The negative surface charge of silicone and hydrophilic IOLs might account for the occurrence of IOL calcification.

  19. Early osseointegration driven by the surface chemistry and wettability of dental implants

    Directory of Open Access Journals (Sweden)

    Suelen Cristina SARTORETTO

    2015-06-01

    Full Text Available Objective The objective of this study was to investigate the impact of two different commercially available dental implants on osseointegration. The surfaces were sandblasting and acid etching (Group 1 and sandblasting and acid etching, then maintained in an isotonic solution of 0.9% sodium chloride (Group 2. Material and Methods X-ray photoelectron spectroscopy (XPS was employed for surface chemistry analysis. Surface morphology and topography was investigated by scanning electron microscopy (SEM and confocal microscopy (CM, respectively. Contact angle analysis (CAA was employed for wetting evaluation. Bone-implant-contact (BIC and bone area fraction occupied (BAFO analysis were performed on thin sections (30 μm 14 and 28 days after the installation of 10 implants from each group (n=20 in rabbits' tibias. Statistical analysis was performed by ANOVA at the 95% level of significance considering implantation time and implant surface as independent variables. Results Group 2 showed 3-fold less carbon on the surface and a markedly enhanced hydrophilicity compared to Group 1 but a similar surface roughness (p>0.05. BIC and BAFO levels in Group 2 at 14 days were similar to those in Group 1 at 28 days. After 28 days of installation, BIC and BAFO measurements of Group 2 were approximately 1.5-fold greater than in Group 1 (p<0.05. Conclusion The surface chemistry and wettability implants of Group 2 accelerate osseointegration and increase the area of the bone-to-implant interface when compared to those of Group 1.

  20. Silicon wafer wettability and aging behaviors: Impact on gold thin-film morphology

    KAUST Repository

    Yang, Xiaoming

    2014-10-01

    This paper reports on the wettability and aging behaviors of the silicon wafers that had been cleaned using a piranha (3:1 mixture of sulfuric acid (H2SO4, 96%) and hydrogen peroxide (H2O 2, 30%), 120 °C), SC1 (1:1:5 mixture of NH4OH, H 2O2 and H2O, at 80°C) or HF solution (6 parts of 40% NH4F and 1 part of 49% HF, at room temperature) solution, and treated with gaseous plasma. The silicon wafers cleaned using the piranha or SC1 solution were hydrophilic, and the water contact angles on the surfaces would increase along with aging time, until they reached the saturated points of around 70°. The contact angle increase rate of these wafers in a vacuum was much faster than that in the open air, because of loss of water, which was physically adsorbed on the wafer surfaces. The silicon wafers cleaned with the HF solution were hydrophobic. Their contact angle decreased in the atmosphere, while it increased in the vacuum up to 95°. Gold thin films deposited on the hydrophilic wafers were smoother than that deposited on the hydrophobic wafers, because the numerous oxygen groups formed on the hydrophilic surfaces would react with gold adatoms in the sputtering process to form a continuous thin film at the nucleation stage. The argon, nitrogen, oxygen gas plasma treatments could change the silicon wafer surfaces from hydrophobic to hydrophilic by creating a thin (around 2.5 nm) silicon dioxide film, which could be utilized to improve the roughness and adhesion of the gold thin film. © 2014 Elsevier Ltd. All rights reserved.

  1. Stable Wettability Control of Nanoporous Microstructures by iCVD Coating of Carbon Nanotubes.

    Science.gov (United States)

    Sojoudi, Hossein; Kim, Sanha; Zhao, Hangbo; Annavarapu, Rama Kishore; Mariappan, Dhanushkodi; Hart, A John; McKinley, Gareth H; Gleason, Karen K

    2017-11-13

    Scalable manufacturing of structured materials with engineered nanoporosity is critical for applications in energy storage devices (i.e. batteries and supercapacitors) and wettability control of surfaces (i.e. superhydrophobic and superomniphobic surfaces). Patterns formed in arrays of vertically aligned carbon nanotubes (VA-CNTs) have been extensively studied for these applications. However, the as-deposited features are often undesirably altered upon liquid infiltration and evaporation due to capillarity-driven aggregation of the low density CNTs. Here, it is found that an ultrathin, conformal, and low surface energy layer of poly-perfluorodecylacrylate, poly-(1H, 1H, 2H, 2H-perfluorodecylacrylate) (pPFDA) makes the VA-CNTs robust against surface-tension driven aggregation and densification. This single vapor-deposition step allows the fidelity of the as-deposited VA-CNT patterns to be retained during wet processing such as inking and subsequent drying. It is demonstrated how to establish omniphobicity or liquid infiltration by controlling the surface morphology. Retaining a crust of entangled CNTs and pPFDA clusters on top of the patterned VA-CNTs, produces micropillars with re-entrant features that prevent the infiltration of low surface tension liquids and thus gives rise to stable omniphobicity. Plasma treatments before and after polymer deposition removes the crust of the entangled CNTs and the pPFDA clusters, enabling liquid infiltration yet preventing densification of the highly-porous CNTs. The latter observation indicates the protective character of the pPFDA coating with potential application of these surfaces for direct contact printing of microelectronic features.

  2. Activated carbon as a carrier for amorphous drug delivery: Effect of drug characteristics and carrier wettability.

    Science.gov (United States)

    Miriyala, Nikhila; Ouyang, Defang; Perrie, Yvonne; Lowry, Deborah; Kirby, Daniel J

    2017-06-01

    Recent research on porous silica materials as drug carriers for amorphous and controlled drug delivery has shown promising results. However, due to contradictory literature reports on toxicity and high costs of production, it is important to explore alternative safe and inexpensive porous carriers. In this study, the potential of activated carbon (AC) as an amorphous drug carrier was investigated using paracetamol (PA) and ibuprofen (IBU) as model drugs. The solution impregnation method was used for drug loading, with loading efficiency determined by UV spectroscopy and drug release kinetics studied using USP II dissolution apparatus. The physical state of the drug in the complex was characterised using differential scanning calorimetry and X-ray diffractions techniques, whilst sites of drug adsorption were studied using Fourier transform infrared spectroscopy and N 2 adsorption techniques. In addition, the cytotoxicity of AC on human colon carcinoma (Caco-2) cells was assessed using the MTT assay. Results presented here reveal that, for PA/AC and IBU/AC complexes, the saturation solubility of the drug in the loading solvent appears to have an effect on the drug loading efficiency and the physical state of the drug loaded, whilst drug release kinetics were affected by the wettability of the activated carbon particles. Furthermore, activated carbon microparticles exhibited very low cytotoxicity on Caco-2 cells at the concentrations tested (10-800μg/mL). This study, therefore, supports the potential of activated carbon as a carrier for amorphous drug delivery. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. 30 CFR 57.3461 - Rock bursts.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Rock bursts. 57.3461 Section 57.3461 Mineral...-Underground Only § 57.3461 Rock bursts. (a) Operators of mines which have experienced a rock burst shall— (1) Within twenty four hours report to the nearest MSHA office each rock burst which: (i) Causes persons to...

  4. Mathematical development of stress-strain law for rock block contacts

    OpenAIRE

    Galindo Aires, Rubén Ángel; Serrano Gonzalez, Alcibiades; Olalla Marañón, Claudio

    2014-01-01

    The fracture behavior of rock block contacts has been studied for many years. Unfortunately, up to now, there is not a rigorous formulation or a solid theoretical foundation to support it. A mathematical development to represent the failure mechanism which occurs in the contacts between rock blocks is presented to evaluate the performance of breaking mechanism of such blocks relating it to the morphology of the contact and mechanical parameters of the material. The examined framework includes...

  5. Characterization of the Intrinsic Water Wettability of Graphite Using Contact Angle Measurements: Effect of Defects on Static and Dynamic Contact Angles.

    Science.gov (United States)

    Kozbial, Andrew; Trouba, Charlie; Liu, Haitao; Li, Lei

    2017-01-31

    Elucidating the intrinsic water wettability of the graphitic surface has increasingly attracted research interests, triggered by the recent finding that the well-established hydrophobicity of graphitic surfaces actually results from airborne hydrocarbon contamination. Currently, static water contact angle (WCA) is often used to characterize the intrinsic water wettability of graphitic surfaces. In the current paper, we show that because of the existence of defects, static WCA does not necessarily characterize the intrinsic water wettability. Freshly exfoliated graphite of varying qualities, characterized using atomic force microscopy and Raman spectroscopy, was studied using static, advancing, and receding WCA measurements. The results showed that graphite of different qualities (i.e., defect density) always has a similar advancing WCA, but it could have very different static and receding WCAs. This finding indicates that defects play an important role in contact angle measurements, and the static contact angle does not always represent the intrinsic water wettability of pristine graphite. On the basis of the experimental results, a qualitative model is proposed to explain the effect of defects on static, advancing, and receding contact angles. The model suggests that the advancing WCA reflects the intrinsic water wettability of pristine (defect-free) graphite. Our results showed that the advancing WCA for pristine graphite is 68.6°, which indicates that graphitic carbon is intrinsically mildly hydrophilic.

  6. Functional groups grafted nonwoven fabrics for blood filtration-The effects of functional groups and wettability on the adhesion of leukocyte and platelet

    Science.gov (United States)

    Yang, Chao; Cao, Ye; Sun, Kang; Liu, Jiaxin; Wang, Hong

    2011-01-01

    In this work, the effects of grafted functional groups and surface wettability on the adhesion of leukocyte and platelet were investigated by the method of blood filtration. The filter materials, poly(butylene terephthalate) nonwoven fabrics bearing different functional groups including hydroxyl (OH), carboxyl (COOH), sulfonic acid group (SO3H) and zwitterionic sulfobetaine group (⊕N((CH3)2)(CH2)3SO3⊖) with controllable wettability were prepared by UV radiation grafting vinyl monomers with these functional groups. Our results emphasized that both surface functional groups and surface wettability had significant effects on the adhesion of leukocyte and platelet. In the case of filter materials with the same wettability, leukocytes adhering to filter materials decreased in the order: the surface bearing OH only > the surface bearing both OH and COOH > the surface bearing sulfobetaine group > the surface bearing SO3H, while platelets adhering to filter materials decreased as the following order: the surface bearing SO3H > the surface bearing both OH and COOH > the surface bearing OH only > the surface bearing sulfobetaine group. As the wettability of filter materials increased, both leukocyte and platelet adhesion to filter materials declined, except that leukocyte adhesion to the surface bearing OH only remained unchanged.

  7. Surface wettability of plasma SiOx:H nanocoating-induced endothelial cells' migration and the associated FAK-Rho GTPases signalling pathways

    Science.gov (United States)

    Shen, Yang; Wang, Guixue; Huang, Xianliang; Zhang, Qin; Wu, Jiang; Tang, Chaojun; Yu, Qingsong; Liu, Xiaoheng

    2012-01-01

    Vascular endothelial cell (EC) adhesion and migration are essential processes in re-endothelialization of implanted biomaterials. There is no clear relationship and mechanism between EC adhesion and migration behaviour on surfaces with varying wettabilities. As model substrates, plasma SiOx:H nanocoatings with well-controlled surface wettability (with water contact angles in the range of 98.5 ± 2.3° to 26.3 ± 4.0°) were used in this study to investigate the effects of surface wettability on cell adhesion/migration and associated protein expressions in FAK-Rho GTPases signalling pathways. It was found that EC adhesion/migration showed opposite behaviour on the hydrophilic and hydrophobic surfaces (i.e. hydrophobic surfaces promoted EC migration but were anti-adhesions). The number of adherent ECs showed a maximum on hydrophilic surfaces, while cells adhered to hydrophobic surfaces exhibited a tendency for cell migration. The focal adhesion kinase (FAK) inhibitor targeting the Y-397 site of FAK could significantly inhibit cell adhesion/migration, suggesting that EC adhesion and migration on surfaces with different wettabilities involve (p)FAK and its downstream signalling pathways. Western blot results suggested that the FAK-Rho GTPases signalling pathways were correlative to EC migration on hydrophobic plasma SiOx:H surfaces, but uncertain to hydrophilic surfaces. This work demonstrated that surface wettability could induce cellular behaviours that were associated with different cellular signalling events. PMID:21715399

  8. Functional groups grafted nonwoven fabrics for blood filtration-The effects of functional groups and wettability on the adhesion of leukocyte and platelet

    Energy Technology Data Exchange (ETDEWEB)

    Yang Chao [State Key Lab of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Cao Ye [Institute of Blood Transfusion, Chinese Academy of Medical Sciences and Peking Union Medical College, Chengdu 610081 (China); Sun Kang, E-mail: ksun@sjtu.edu.cn [State Key Lab of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Liu Jiaxin; Wang Hong [Institute of Blood Transfusion, Chinese Academy of Medical Sciences and Peking Union Medical College, Chengdu 610081 (China)

    2011-01-15

    In this work, the effects of grafted functional groups and surface wettability on the adhesion of leukocyte and platelet were investigated by the method of blood filtration. The filter materials, poly(butylene terephthalate) nonwoven fabrics bearing different functional groups including hydroxyl (OH), carboxyl (COOH), sulfonic acid group (SO{sub 3}H) and zwitterionic sulfobetaine group ({sup +}N((CH{sub 3}){sub 2})(CH{sub 2}){sub 3}SO{sub 3}{sup Circled-Minus }) with controllable wettability were prepared by UV radiation grafting vinyl monomers with these functional groups. Our results emphasized that both surface functional groups and surface wettability had significant effects on the adhesion of leukocyte and platelet. In the case of filter materials with the same wettability, leukocytes adhering to filter materials decreased in the order: the surface bearing OH only > the surface bearing both OH and COOH > the surface bearing sulfobetaine group > the surface bearing SO{sub 3}H, while platelets adhering to filter materials decreased as the following order: the surface bearing SO{sub 3}H > the surface bearing both OH and COOH > the surface bearing OH only > the surface bearing sulfobetaine group. As the wettability of filter materials increased, both leukocyte and platelet adhesion to filter materials declined, except that leukocyte adhesion to the surface bearing OH only remained unchanged.

  9. The effect of amorphous silicon surface hydrogenation on morphology, wettability and its implication on the adsorption of proteins

    Energy Technology Data Exchange (ETDEWEB)

    Filali, Larbi, E-mail: larbifilali5@gmail.com [Laboratoire de Physique des Couches Minces et Matériaux pour l' Electronique, Université d' Oran 1, Ahmed Ben Bella, BP 1524, El M' naouar 31100 Oran (Algeria); Brahmi, Yamina; Sib, Jamal Dine [Laboratoire de Physique des Couches Minces et Matériaux pour l' Electronique, Université d' Oran 1, Ahmed Ben Bella, BP 1524, El M' naouar 31100 Oran (Algeria); Bouhekka, Ahmed [Laboratoire de Physique des Couches Minces et Matériaux pour l' Electronique, Université d' Oran 1, Ahmed Ben Bella, BP 1524, El M' naouar 31100 Oran (Algeria); Département de Physique, Université Hassiba Ben Bouali, 02000 Chlef (Algeria); Benlakehal, Djamel; Bouizem, Yahya; Kebab, Aissa; Chahed, Larbi [Laboratoire de Physique des Couches Minces et Matériaux pour l' Electronique, Université d' Oran 1, Ahmed Ben Bella, BP 1524, El M' naouar 31100 Oran (Algeria)

    2016-10-30

    Highlights: • Hydrogenation of the surfaces had the effect of reducing the roughness by way of shadow etching. • Roughness was the driving factor affecting the wettability of the hydrogenated surfaces. • Bovine Serum Albumin proteins favored the surfaces with highest hydrogen content. • Surface modification induced secondary structure change of adsorbed proteins. - Abstract: We study the effect of amorphous silicon (a-Si) surface hydrogenation on Bovine Serum Albumin (BSA) adsorption. A set of (a-Si) films was prepared by radio frequency magnetron sputtering (RFMS) and after deposition; they were treated in molecular hydrogen ambient at different pressures (1–3 Pa). Fourier transform infrared attenuated total reflection (FTIR-ATR) spectroscopy and spectroscopic ellipsometry (SE) were used to study the hydrogenation effect and BSA adsorption. Atomic force microscopy (AFM) was used to evaluate morphological changes caused by hydrogenation. The wettability of the films was measured using contact angle measurement, and in the case of the hydrogenated surfaces, it was found to be driven by surface roughness. FTIR-ATR spectroscopy and SE measurements show that proteins had the strongest affinity toward the surfaces with the highest hydrogen content and their secondary structure was affected by a significant decrease of the α-helix component (-27%) compared with the proteins adsorbed on the un-treated surface, which had a predominantly α-helix (45%) structure. The adsorbed protein layer was found to be densely packed with a large thickness (30.9 nm) on the hydrogen-rich surfaces. The most important result is that the surface hydrogen content was the dominant factor, compared to wettability and morphology, for protein adsorption.

  10. Surface wettability and energy effects on the biological performance of poly-3-hydroxybutyrate films treated with RF plasma

    Energy Technology Data Exchange (ETDEWEB)

    Syromotina, D.S. [Department of Experimental Physics, National Research Tomsk Polytechnic University, 634050 Tomsk (Russian Federation); Surmenev, R.A., E-mail: rsurmenev@gmail.com [Department of Experimental Physics, National Research Tomsk Polytechnic University, 634050 Tomsk (Russian Federation); Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, 70569 Stuttgart (Germany); Surmeneva, M.A. [Department of Experimental Physics, National Research Tomsk Polytechnic University, 634050 Tomsk (Russian Federation); Boyandin, A.N.; Nikolaeva, E.D. [Institute of Biophysics of Siberian Branch of Russian Academy of Sciences, 50/50 Akademgorodok, Krasnoyarsk 660036 (Russian Federation); School of Fundamental Biology and Biotechnology, Siberian Federal University, 79 Svobodny pr., 660041 Krasnoyarsk (Russian Federation); Prymak, O.; Epple, M. [Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, 45117 Essen (Germany); Ulbricht, M. [Technical Chemistry II and Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, 45141 Essen (Germany); Oehr, C. [Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, 70569 Stuttgart (Germany); Volova, T.G. [Institute of Biophysics of Siberian Branch of Russian Academy of Sciences, 50/50 Akademgorodok, Krasnoyarsk 660036 (Russian Federation); School of Fundamental Biology and Biotechnology, Siberian Federal University, 79 Svobodny pr., 660041 Krasnoyarsk (Russian Federation)

    2016-05-01

    The surface properties of poly-3-hydroxybutyrate (P3HB) membranes were modified using oxygen and an ammonia radio-frequency (RF, 13.56 MHz) plasma. The plasma treatment procedures used in the study only affected the surface properties, including surface topography, without inducing any significant changes in the crystalline structure of the polymer, with the exception being a power level of 250 W. The wettability of the modified P3HB surfaces was significantly increased after the plasma treatment, irrespective of the treatment procedure used. It was revealed that both surface chemistry and surface roughness changes caused by the plasma treatment affected surface wettability. A treatment-induced surface aging effect was observed and resulted in an increase in the water contact angle and a decrease in the surface free energy. However, the difference in the water contact angle between the polymers that had been treated for 4 weeks and the untreated polymer surfaces was still significant. A dependence between cell adhesion and proliferation and the polar component of the surface energy was revealed. The increase in the polar component after the ammonia plasma modification significantly increased cell adhesion and proliferation on biodegradable polymer surfaces compared to the untreated P3HB and the P3HB modified using an oxygen plasma. - Highlights: • Plasma treatment affected the topography of poly(3-hydroxybutyrate) (P3HB). • Plasma treatment resulted in improvement of the surface wettability. • No alteration of the bulk properties of the polymers was observed. • The ammonia plasma treatment at 150 W improved the cell adhesion and proliferation.

  11. Rock Pore Structure as Main Reason of Rock Deterioration

    Directory of Open Access Journals (Sweden)

    Ondrášik Martin

    2014-03-01

    Full Text Available Crashed or dimensional rocks have been used as natural construction material, decoration stone or as material for artistic sculptures. Especially old historical towns not only in Slovakia have had experiences with use of stones for construction purposes for centuries. The whole buildings were made from dimensional stone, like sandstone, limestone or rhyolite. Pavements were made especially from basalt, andesite, rhyolite or granite. Also the most common modern construction material - concrete includes large amounts of crashed rock, especially limestone, dolostone and andesite.

  12. Wettability of Ti3SiC2 by Ag-Cu and Ag-Cu-Ti melts

    OpenAIRE

    Dezellus, Olivier; Voytovych, R.; Li A., P.-H.; Constantin, G.; Bosselet, F.; Viala, J.C.

    2009-01-01

    International audience; Recently, the ternary carbide Ti3SiC2 has gained much attention due to its unique characteristics combining the properties of metals and ceramics (i.e., a low density, decent thermal and electrical conductivities, an excellent thermal shock resistance, a good machinability, damage tolerance, low friction and so on). The present study describes an investigation of the wettability in high vacuum of bulk Ti3SiC2 by a classical braze alloy based on the Ag-Cu-Ti system. Two...

  13. Wettability characteristics of a modified mild steel with CO2, Nd:YAG, excimer and high power diode lasers

    OpenAIRE

    Lawrence, Jonathan; Li, Lin

    1999-01-01

    Interaction of CO2, Nd:YAG, excimer and high-power diode laser radiation with the surface of a common mild steel (EN8) was found to effect changes in the wettability characteristics of the steel, namely changes in the measured contact angle of certain liquids. Such changes were identified as being due to modifications to (i) the surface roughness, (ii) changes in the surface oxygen content and (iii) changes in the surface energy of the mild steel. However, it was found that changes in the wet...

  14. Polygon/Cracked Sedimentary Rock

    Science.gov (United States)

    2004-01-01

    4 December 2004 Exposures of sedimentary rock are quite common on the surface of Mars. Less common, but found in many craters in the regions north and northwest of the giant basin, Hellas, are sedimentary rocks with distinct polygonal cracks in them. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows an example from the floor of an unnamed crater near 21.0oS, 311.9oW. Such cracks might have formed by desiccation as an ancient lake dried up, or they might be related to ground ice freeze/thaw cycles or some other stresses placed on the original sediment or the rock after it became lithified. The 300 meter scale bar is about 328 yards long. The scene is illuminated by sunlight from the upper left.

  15. The permeability of heterogeneous rocks

    Science.gov (United States)

    Selvadurai, Patrick

    2017-04-01

    Darcy's original concept of permeability is largely associated with estimation of the hydraulic conductivity characteristics of isotropic and homogeneous porous media where the fluid flow characteristics can be estimated by appeal to a single scalar measure. Naturally occurring geomaterials are heterogeneous and the estimation of the effective permeability characteristics of such geomaterials presents a challenge not only in terms of the experimental procedures that should be used to ensure flow through the porous medium but also in the correct use of the theoretical concepts needed to accurately interpret the data. Relatively widely referred to rocks such as Indiana Limestone can exhibit spatial heterogeneity in the permeability characteristics even though the visual appearance can suggest the absence of such spatial and directional attributes (Selvadurai and Selvadurai, 2010). Argillaceous rocks such as the Cobourg Limestone found in southern Ontario, Canada can display hydraulic heterogeneity that is attributed to the presence of dolomitic and calcite nodular regions separated by calcite rock partings that contain an argillaceous component (Figure 1). Also, these rocks have extremely low permeability that requires the use of transient hydraulic pulse tests for the estimation of permeability. The performance of such pulse tests will be influenced by the bulk compressibility and bulk porosity of the porous skeleton consisting of the identifiable phases and their spatial distributions. The concepts of effective compressibilities and porosities therefore needs to be introduced if convenient procedures are to be developed for the accurate interpretation of even bench scale experiments (Selvadurai and Gɫowacki, 2017). The paper will describe both experimental and theoretical approaches for interpreting the effective Darcy permeability of the heterogeneous rocks using both experimental and computational approaches. In particular, the applicability of the "Geometric

  16. Flow heterogeneity in reservoir rocks

    Energy Technology Data Exchange (ETDEWEB)

    Rosman, A.; Simon, R.

    1975-01-01

    A study by Chevron Oil Field Research Co. shows that microscopic flow heterogeneity values are essential for interpreting laboratory displacement data and properly evaluating field displacement projects. Chevron discusses microscopic flow heterogeneity in reservoir rocks: a measuring method, results of some measurements, and several applications to reservoir engineering problems. Heterogeneity is expressed in terms of both breakthrough recovery and the Dykstra-Parsons permeability variation. Microscopic flow heterogeneity in a reservoir rock is related to pore size, pore shape, and location of the different pore sizes that determine flow paths of various permeabilities. This flow heterogeneity affects secondary recovery displacement efficiency, residual oil and water saturations, and capillary pressure measurements.

  17. Evaluation of Rock Joint Coefficients

    Science.gov (United States)

    Audy, Ondřej; Ficker, Tomáš

    2017-10-01

    A computer method for evaluation of rock joint coefficients is described and several applications are presented. The method is based on two absolute numerical indicators that are formed by means of the Fourier replicas of rock joint profiles. The first indicator quantifies the vertical depth of profiles and the second indicator classifies wavy character of profiles. The absolute indicators have replaced the formerly used relative indicators that showed some artificial behavior in some cases. This contribution is focused on practical computations testing the functionality of the newly introduced indicators.

  18. Range sections as rock models for intensity rock scene segmentation

    CSIR Research Space (South Africa)

    Mkwelo, S

    2007-11-01

    Full Text Available can be used to extract intensity edges of relevance in terms of orientation and position. Conventional polynomial fitting is used to extract the underlying rock shape as a final segmentation. Preliminary results on a small laboratory data set using...

  19. Comparison of flow and transport experiments on 3D printed 'rocks' with direct numerical simulations

    Science.gov (United States)

    Watson, F. E.; Geiger, S.; Mackay, E.; Singleton, M.; McGravie, T.; Anouilh, T.; Jobe, D.; Zhang, S.; Agar, S. M.; Ishutov, S.; Hasiuk, F.; Chalaturnyk, R. J.

    2016-12-01

    3D printing technology has the potential to revolutionise modelling of fluid flow and mass transport in porous media. Using 3D printing to replicate pore geometries from real rocks quickly and cheaply, and being able to assign specific properties to the samples, would enable us to repeat experiments where things such as permeability, porosity, reactivity, or wettability are known a priori. Destructive tests, such as reactive transport experiments, could then be performed using the same, realistic, initial geometry, in a repeatable fashion; in addition, specific properties of the porous media (e.g. the reactivity of individual grains) could be altered in a controlled way. Similarly, two-phase flow experiments could be carried out where relevant properties (e.g. individual grain wettability) are modified between experiments. Results from such experiments would shed new light on key physio-chemical processes occurring at the pore-scale during multi-phase reactive flow and would allow us to validate the suite of emerging direct numerical simulation techniques (e.g. Lattice Boltzman, Volume of Fluid) currently used to model pore-scale flow and transport. We have developed a novel experimental setup to investigate single-phase flow and transport through translucent 3D printed and Perspex samples and to visualise the experiments for comparison with numerical simulations. Dyed fluid is injected at one end of the sample and the behaviour of the system is recorded using a digital camera situated directly above it. Image processing techniques are employed to quantify dye concentration and location through time. We use the finite volume method to simulate the flow experiments in OpenFOAM, using the same input geometry that was used to print the sample. Comparison of experimental results with simulations enables us to identify similarities and differences between flow and transport observed in the 3D printed samples and behaviour expected from the numerical simulations.

  20. Framework Spring

    OpenAIRE

    Bobkov, Pavel

    2010-01-01

    The aim of the thesis is to introduce reader to the Spring framework and describe it as a convenient tool for rapid application development and launching projects. It is necessary to grab the Spring issue in a broader context. That's why thesis is trying to note all the relevant technologies that are closely related to Spring, or which is Spring based on. The first step to understanding Spring is a basic knowledge of Java EE. Thesis presents the architecture of Java EE while arguing its flaws...

  1. Flow split characterization of two immiscible phases with different wettability scenarios: a numerical investigation using a coupled Cahn-Hilliard and Navier-Stokes system

    KAUST Repository

    Bao, Kai

    2017-12-23

    Numerical investigation of flow branching of two-phase immiscible fluids in a Y-shaped, planner channel is conducted by solving the coupled Cahn-Hilliard and Naiver-Stokes system with finite element method. In this system a horizontal channel is branched into two identical and symmetric branches with the walls of the channels assigned several different wettability values. The studied scenarios consider a blob of one phase initially encompassed by the other phase. When an applied pressure difference induces flow, it is found that the motion of the blob in the two branches is significantly influenced by the wettability conditions at the channel walls. For the scenarios in which symmetric wettability configurations are applied, the blob divides equally among the two branches. For all the other scenarios in which the wettability configurations are asymmetric, the blob splits unequally. Comparisons between the different scenarios are performed in terms of the volume of the blob in each branch to investigate the percentage of the blob volume moving in each branch. In addition, we also considered the effect of the flow rate on the branching scenarios. In this work it is demonstrated that even though the pressure gradient is the same among the two symmetric branches, the phases partition differently when asymmetric wettability conditions are applied. The significance of this work may be that it provides evidences that relative permeability (a concept that has been introduced in the study of multiphase flow in porous media) may be more complex than just a mere scalar quantity function of saturation. It also highlights the importance of including the effects of wettability conditions in capillary pressure relationships

  2. Study on the Microstructure and Wettability of an Al-Cu-Si Braze Containing Small Amounts of Rare Earth Erbium

    Science.gov (United States)

    Shi, Yaowu; Yu, Yang; Li, Yapeng; Xia, Zhidong; Lei, Yongping; Li, Xiaoyan; Guo, Fu

    2009-04-01

    The effect of adding small amounts of rare earth Er on the microstructure of an Al-Cu-Si braze alloy has been investigated. Several Al-20Cu-7Si braze alloys containing various contents of Er were prepared, and their melting temperature, microstructure, hardness, and wettability in contact with 3003 aluminum alloy substrates were determined. The results indicate that the constituents of the microstructure of Al-20Cu-7Si-Er braze alloys are similar to those in the Al-20Cu-7Si alloy, and comprise of solid solutions of aluminum, silicon, and the intermetallic compound CuAl2. When the Er content increases, the size of the Al phase decreases, and the needle-like Si phase is thickened, and transformed to a blocky shape. Moreover, small amounts of Er can improve the wettability and hardness of the Al-20Cu-7Si braze alloy; however, the melting temperature of the Al-20Cu-7Si alloy does not change.

  3. Photoirradiation Caused Controllable Wettability Switching of Sputtered Highly Aligned c-Axis-Oriented Zinc Oxide Columnar Films

    Directory of Open Access Journals (Sweden)

    P. W. Chi

    2014-01-01

    Full Text Available This study presents the microstructure morphology and UV photoirradiation coupling effects of the c-axis-oriented zinc oxide (ZnO columnar films. Highly aligned c-axis-oriented films have been deposited onto glass substrates at room temperature by radio-frequency (RF magnetron sputtering without introducing any oxygen source under different sputtering powers ranging from 50 to 150 W. Self-assembled ZnO columnar structures that were successfully obtained belong to wurtzite structure, and the corresponding columnar structures and crystalline orientation were confirmed by the FE-SEM and XRD, respectively. All the ZnO columnar films exhibit good transparency with a visible light averaged transmittance over 82%. According to water contact angle (CA measurement, ZnO columnar films exhibit hydrophobic behavior. After exposing to photoirradiation under ultraviolet (UV environment, all the ZnO samples showed remarkable transition from hydrophobic to superhydrophilic surfaces and could return to their original hydrophobicity after being placed in the dark. It is demonstrated that the controllable wettability of ZnO columnar films under changing between the UV photoirradiation and dark storage is due to the surface charges accumulation and discharging processes. As a result, this study could provide important applications for many fields such as ZnO-based hybrid sensors/solar cells functional devices with photoirradiation disinfection surfaces accompanied with reversible wettability switches.

  4. Bio-inspired micro-nano structured surface with structural color and anisotropic wettability on Cu substrate

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yan [Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022 (China); State Key Laboratory of Automotive Simulation and Control, Jilin University, Changchun 130022 (China); Li, Shuyi; Niu, Shichao [Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022 (China); Cao, Xiaowen [Key Laboratory on Integrated Optoelectronics College of Electronic Science and Engineering, Jilin University, Changchun 130012 (China); Han, Zhiwu, E-mail: zwhan@jlu.edu.cn [Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022 (China); Ren, Luquan [Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022 (China)

    2016-08-30

    Highlights: • We have prepared a biomimetic hydrophobic surface on copper substrate by one-step femtosecond laser technique. • The hydrophobicity mechanism relies on morphology and chemical component on surface. • The hydrophobic surfaces exhibit different structural colors and a anisotropic wettability. - Abstract: Inspired by the unique creatures in the nature, the femtosecond laser technology has been usually used to fabricate the periodic microstructures due to its advantages of rapidness, simplicity, ease of large-area fabrication, and simultaneously offering dual micro/nano-scale structures simply via one-step process for a wide variety of materials. By changing the experimental conditions, multi-functional surfaces which possess superhydrophobicity and structural colors could be achieved on copper substrate. In addition, the apparent contact angle can reach 144.3° without any further modification, which also exhibits the anisotropic wettability. Moreover, it can be inferred that higher laser fluence can lead to a larger CA within a certain range. At the same time, due to the change of laser processing parameters, the obtained surfaces present different structural colors. This study may expand the applications of bio-inspired functional materials because multiple colors and hydrophobicity are both important features in the real life and industrial applications, such as display, decoration, and anti-counterfeiting technology etc.

  5. Wettability, Polarity, and Water Absorption of Holm Oak Leaves: Effect of Leaf Side and Age1[OPEN

    Science.gov (United States)

    Fernández, Victoria; Sancho-Knapik, Domingo; Guzmán, Paula; Peguero-Pina, José Javier; Gil, Luis; Karabourniotis, George; Khayet, Mohamed; Fasseas, Costas; Heredia-Guerrero, José Alejandro; Heredia, Antonio; Gil-Pelegrín, Eustaquio

    2014-01-01

    Plant trichomes play important protective functions and may have a major influence on leaf surface wettability. With the aim of gaining insight into trichome structure, composition, and function in relation to water-plant surface interactions, we analyzed the adaxial and abaxial leaf surface of holm oak (Quercus ilex) as a model. By measuring the leaf water potential 24 h after the deposition of water drops onto abaxial and adaxial surfaces, evidence for water penetration through the upper leaf side was gained in young and mature leaves. The structure and chemical composition of the abaxial (always present) and adaxial (occurring only in young leaves) trichomes were analyzed by various microscopic and analytical procedures. The adaxial surfaces were wettable and had a high degree of water drop adhesion in contrast to the highly unwettable and water-repellent abaxial holm oak leaf sides. The surface free energy and solubility parameter decreased with leaf age, with higher values determined for the adaxial sides. All holm oak leaf trichomes were covered with a cuticle. The abaxial trichomes were composed of 8% soluble waxes, 49% cutin, and 43% polysaccharides. For the adaxial side, it is concluded that trichomes and the scars after trichome shedding contribute to water uptake, while the abaxial leaf side is highly hydrophobic due to its high degree of pubescence and different trichome structure, composition, and density. Results are interpreted in terms of water-plant surface interactions, plant surface physical chemistry, and plant ecophysiology. PMID:24913938

  6. Electromagnetic, magnetorheological and stability properties of polysiloxane elastomers based on silane-modified carbonyl iron particles with enhanced wettability

    Science.gov (United States)

    Cvek, Martin; Moucka, Robert; Sedlacik, Michal; Pavlinek, Vladimir

    2017-10-01

    Soft carbonyl iron (CI) particles were successfully modified with a thin layer of tetraethoxysilane (TEOS) to enhance the wettability of their surface in hydrophobic media. The contact angle investigations and tensiometric analysis revealed and helped quantify the significantly enhanced wettability and, thus, the better interfacial adhesion of the TEOS-coated CI particles (CI-TEOS) with the non-polar siloxane-based materials. Therefore, stable magnetorheological elastomers (MREs) based on CI-TEOS particles and polydimethyl siloxane matrix were fabricated. The prepared composites had different particle loadings and microstructural characteristics: isotropic and anisotropic. These structural differences were confirmed by scanning electron microscopy and were found to considerably affect dielectric properties of the MREs due to various charge transport mechanisms within the particle clusters. Furthermore, the magnetorheological (MR) performances of isotropic MRE variants were analysed before and after exposure to acidic environment. After the corrosion test, the MRE based on bare CI particles exhibited dramatically decreased relative MR effect and mechanical properties when compared with its analogue containing CI-TEOS.

  7. Wettability Investigation of UV/O3 and Acid Functionalized MWCNT and MWCNT/PMMA Nanocomposites by Contact Angle Measurement

    Directory of Open Access Journals (Sweden)

    Seil Kim

    2015-01-01

    Full Text Available The dispersion state of individual MWCNT in the polymer matrix influences the mechanical, thermal, and electrical properties of the resulting composite. One method of obtaining a good dispersion state of MWCNT in a polymer matrix is to functionalize the surface of MWCNT using various treatments to enhance the surface energy and increase the dispersibility of MWCNT. In this study, wettability and surface energy of UV/O3 and acid-treated multiwall carbon nanotubes (MWCNTs and its polymethyl methacrylate (PMMA polymer nanocomposites were measured using contact angle analysis in various solvent media. Contact angle analysis was based on ethylene glycol-water-glycerol probe liquid set and data was further fitted into geometric mean (Fowkes, van Oss-Chaudhury-Good (GvOC, and Chang-Qing-Chen (CQC models to determine both nonpolar and acid base surface energy components. Analysis was conducted on MWCNT thin films subjected to different levels of UV/O3 and acid treatments as well as their resulting MWCNT/PMMA nanocomposites. Contact angle analysis of thin films and nanocomposites revealed that the total surface energy of all samples was well fitted with each other. In addition, CQC model was able to determine the surface nature and polarity of MWCNT and its nanocomposites. Results indicated that the wettability changes in the thin film and its nanocomposites are due to the change in surface chemistry. Finally, electrical properties of nanocomposites were measured to investigate the effect of surface functionality (acid or basic on the MWCNT surfaces.

  8. Vaporization and Poor Wettability as the Main Challenges in Fabrication of TiB2-Cu Cermets Studied by SPS

    Directory of Open Access Journals (Sweden)

    Marta Ziemnicka-Sylwester

    2014-12-01

    Full Text Available TiB2-Cu cermets with various volume fractions of copper (from 3 to 30 vol. % were produced via liquid phase sintering at the temperature range 1100–1200 °C in vacuum using spark plasma sintering (SPS technique. Full densification could not be achieved as the consequence of poor wettability and vaporizing Cu. The quantitative Rietveld analysis indicated that insignificant reduction in Cu content occurred only in sample with initially 3 vol. % of Cu, but then densification was negligible. The relative density improved along with increasing volume content of Cu (10–20 vol. %, but then predominant amount of Cu introduced was reduced as the effect of vaporization or swelling, which caused that pellet with intended 20 or 30 vol. % of Cu contained respectively only 6 or 17 vol. % after sintering. Moreover, Cu droplets were released from the die at the temperature of 1000–1030 °C near the Cu melting point. The effect of vaporization was successfully reduced by increased heating rate and when isothermal annealing process was skipped, however, it could not be entirely eliminated. The experimental results on Cu vaporization are confronted with parameters that are commonly considered in the production of cermets, such as oxidation, wettability, contact angle and viscosity as well as their impact on densification.

  9. Fast wettability transition from hydrophilic to superhydrophobic laser-textured stainless steel surfaces under low-temperature annealing

    Science.gov (United States)

    Ngo, Chi-Vinh; Chun, Doo-Man

    2017-07-01

    Recently, the fabrication of superhydrophobic metallic surfaces by means of pulsed laser texturing has been developed. After laser texturing, samples are typically chemically coated or aged in ambient air for a relatively long time of several weeks to achieve superhydrophobicity. To accelerate the wettability transition from hydrophilicity to superhydrophobicity without the use of additional chemical treatment, a simple annealing post process has been developed. In the present work, grid patterns were first fabricated on stainless steel by a nanosecond pulsed laser, then an additional low-temperature annealing post process at 100 °C was applied. The effect of 100-500 μm step size of the textured grid upon the wettability transition time was also investigated. The proposed post process reduced the transition time from a couple of months to within several hours. All samples showed superhydrophobicity with contact angles greater than 160° and sliding angles smaller than 10° except samples with 500 μm step size, and could be applied in several potential applications such as self-cleaning and control of water adhesion.

  10. Density control and wettability enhancement by functionalizing carbon nanotubes with nickel oxide in aluminum-carbon nanotube system.

    Science.gov (United States)

    Kim, Tae-Hoon; Park, Min-Ho; Song, Kwan-Woo; Bae, Jee-Hwan; Lee, Jae-Wook; Lee, Choong Do; Yang, Cheol-Woong

    2013-11-01

    Excellent mechanical properties of carbon nanotubes (CNTs) make them ideal reinforcements for synthesizing light weight, high strength metal matrix composite. Aluminum is attractive matrix due to its light weight and Al/CNT composites are promising materials for various industrial applications. Powder metallurgy and casting techniques are normally used for bulk fabrications of composites. Casting process which can mass-produce delicate product is more suitable than existing powder metallurgy in view point of application in industries. In CNT-metal matrix composites, however, composite bulk fabrication has been limited because of the large density gap and poor wettability between the metal and CNTs. This study suggests a method for alleviating such problems. It was found that the wettability between aluminum and CNT could be enhanced by functionalizing the CNTs with nickel oxide. This functionalization of CNTs with heavier element also reduces the density gap between the matrix and reinforcements. It is suggested that this method could possibly be used in a casting process to enable mass fabrication of CNT-metal matrix composites.

  11. Black Silicon/Elastomer Composite Surface with Switchable Wettability and Adhesion between Lotus and Rose Petal Effects by Mechanical Strain.

    Science.gov (United States)

    Park, Jun Kyu; Yang, Zining; Kim, Seok

    2017-09-27

    Although many recent studies demonstrate surfaces with switchable wettability under various external stimuli, a deliberate effort to self-propel liquid droplets utilizing a surface wetting mode switch between slippery lotus and adhesive rose petal states via a mechanical strain has not been made yet, which would otherwise further benefit microfluidic applications. In this work, we present a black silicon/elastomer (bSi/elastomer) composite surface which shows switchable wettability and adhesion across the two wetting modes by mechanical stretching. The composite surface is composed of a scale-like nanostructured silicon platelet array that covers an elastomer surface. The gap between the neighboring silicon platelets is reversibly changeable as a function of a mechanical strain, leading to the transition between the two wetting modes. Moreover, the composite surface is highly flexible although its wetting properties primarily originate from superhydrophobic bSi platelets. Different wetting characteristics of the composite surface in various mechanical strains are studied, and droplet manipulation such as droplet self-propulsion and pick-and-place using the composite surface is demonstrated, which highlights its potentials for microfluidic applications.

  12. Gelatin-Based Nanocomplex-Stabilized Pickering Emulsions: Regulating Droplet Size and Wettability through Assembly with Glucomannan.

    Science.gov (United States)

    Jin, Weiping; Zhu, Jieyu; Jiang, Yike; Shao, Ping; Li, Bin; Huang, Qingrong

    2017-02-22

    Particle size and surface wettability play leading roles in the distribution of particles on the oil-water interface and the stability of emulsions. This work utilized nanocomplexes assembled from gelatin and tannic acid to stabilize Pickering emulsions. The sizes and surface wettability of particles were further regulated by using a polysaccharide. The sizes of nanocomplexes ranged from 205.8 to 422.2 nm and increased with the addition of polysaccharide. Their contact angles decreased from 84.1° to 59.3°, revealing their hydrophilic nature. Results of fluorescence microscopy and cryo-scanning electron microscopy indicated that nanocomplexes were located at the oil-water interface. Interfacial shear and dilatational rheological data revealed a fast and irreversible adsorption behavior, which differed from rearrangement of gelatin molecules at the oil-water interface. The minimal concentration of nanocomplexes required to stabilize emulsions was 0.1 wt %. Our results demonstrated that protein-polyphenol-polysaccharide nanocomplexes had the potential to be applied to form stable surfactant-free food emulsions for the delivery of nutraceuticals.

  13. Linking Findings in Microfluidics to Membrane Emulsification Process Design: The Importance of Wettability and Component Interactions with Interfaces

    Directory of Open Access Journals (Sweden)

    Karin Schroën

    2016-05-01

    Full Text Available In microfluidics and other microstructured devices, wettability changes, as a result of component interactions with the solid wall, can have dramatic effects. In emulsion separation and emulsification applications, the desired behavior can even be completely lost. Wettability changes also occur in one phase systems, but the effect is much more far-reaching when using two-phase systems. For microfluidic emulsification devices, this can be elegantly demonstrated and quantified for EDGE (Edge-base Droplet GEneration devices that have a specific behavior that allows us to distinguish between surfactant and liquid interactions with the solid surface. Based on these findings, design rules can be defined for emulsification with any micro-structured emulsification device, such as direct and premix membrane emulsification. In general, it can be concluded that mostly surface interactions increase the contact angle toward 90°, either through the surfactant, or the oil that is used. This leads to poor process stability, and very limited pressure ranges at which small droplets can be made in microfluidic systems, and cross-flow membrane emulsification. In a limited number of cases, surface interactions can also lead to lower contact angles, thereby increasing the operational stability. This paper concludes with a guideline that can be used to come to the appropriate combination of membrane construction material (or any micro-structured device, surfactants and liquids, in combination with process conditions.

  14. Classification Scheme for Diverse Sedimentary and Igneous Rocks Encountered by MSL in Gale Crater

    Science.gov (United States)

    Schmidt, M. E.; Mangold, N.; Fisk, M.; Forni, O.; McLennan, S.; Ming, D. W.; Sumner, D.; Sautter, V.; Williams, A. J.; Gellert, R.

    2015-01-01

    The Curiosity Rover landed in a lithologically and geochemically diverse region of Mars. We present a recommended rock classification framework based on terrestrial schemes, and adapted for the imaging and analytical capabilities of MSL as well as for rock types distinctive to Mars (e.g., high Fe sediments). After interpreting rock origin from textures, i.e., sedimentary (clastic, bedded), igneous (porphyritic, glassy), or unknown, the overall classification procedure (Fig 1) involves: (1) the characterization of rock type according to grain size and texture; (2) the assignment of geochemical modifiers according to Figs 3 and 4; and if applicable, in depth study of (3) mineralogy and (4) geologic/stratigraphic context. Sedimentary rock types are assigned by measuring grains in the best available resolution image (Table 1) and classifying according to the coarsest resolvable grains as conglomerate/breccia, (coarse, medium, or fine) sandstone, silt-stone, or mudstone. If grains are not resolvable in MAHLI images, grains in the rock are assumed to be silt sized or smaller than surface dust particles. Rocks with low color contrast contrast between grains (e.g., Dismal Lakes, sol 304) are classified according to minimum size of apparent grains from surface roughness or shadows outlining apparent grains. Igneous rocks are described as intrusive or extrusive depending on crystal size and fabric. Igneous textures may be described as granular, porphyritic, phaneritic, aphyric, or glassy depending on crystal size. Further descriptors may include terms such as vesicular or cumulate textures.

  15. Plant Communities of Rough Rock.

    Science.gov (United States)

    Jacobs, Linda

    A unit of study on plants grown in the Navajo community of Rough Rock, Arizona, is presented in sketches providing the common Navajo name for the plant, a literal English translation, the English name of the plant, and the Latin name. A brief description of each plant includes where the plant grows, how the Navajos use the plant, and the color and…

  16. Stress wave propagation in rock

    Energy Technology Data Exchange (ETDEWEB)

    Grady, D.E

    1977-01-01

    Earth penetration, design and hardening of structures to explosive or earthquake-induced ground shock effects, rapid excavation, and in situ preparation of coal, shale, or geothermal deposits are representative problems in which accurate constitutive descriptions of the geological medium are required to provide meaningful predictions. The rock or rock masses involved undergo complex, finite amplitude deformation during the process of transient dynamic loading, and quasi-static experimental compression techniques are normally used to provide much of the necessary data base. Strain rates typically range between 10/sup 1//s and 10/sup 5//s in the problems of interest, however, and further studies are required to determine the importance of rate dependence in the mechanical constitutive behavior of rock. Material response at the higher strain rates can be investigated with impact generated stress waves where controlled strain rates between about 10/sup 4//s to 10/sup 7//s can be achieved. Experimental methods have been developed to conduct and analyze impact-induced shock wave, ramp wave, and tensile fracture studies. Experimental results on some select crustal silicate and carbonate rocks show that strain rate dependence and the processes of phase transformation, compressive yielding, and fracture are important features in the dynamic constitutive response.

  17. Metamorphic Rocks in West Irian

    NARCIS (Netherlands)

    Wegen, van der G.

    1971-01-01

    Low-grade metamorphics of West Irian occur to the east of Geelvink Bay associated with two narrow belts of basic and ultrabasic igneous rocks which represent ophiolitic suites of an eugeosynclinical development beginning in Early Mesozoic time. In both of these belts there are indications of

  18. Rock Music and Music Videos.

    Science.gov (United States)

    Hendren; Strasburger

    1993-10-01

    Sex, violence, sexual violence, drugs, suicide, satanic worship, and racism are common themes in modern rock lyrics. The authors examine their effect on adolescent development and identity, concluding with a discussion of the roles of parents and health care professionals in addressing the problem.

  19. Los abuelos de nuestro rock

    Directory of Open Access Journals (Sweden)

    Jacobo Celnik

    2016-12-01

    Full Text Available Los Yetis. Una bomba atómica a go go. La historia de los abuelos de nuestro rock. Diego Londoño; Pulso & Letra Editores, Instituto para el Desarrollo de Antioquia, Instituto de Cultura y Patrimonio de Antioquia, 2014, 98 págs., fotografías.

  20. Simulation of rock deformation behavior

    Directory of Open Access Journals (Sweden)

    Я. И. Рудаев

    2016-12-01

    Full Text Available A task of simulating the deformation behavior of geomaterials under compression with account of over-extreme branch has been addressed. The physical nature of rock properties variability as initially inhomogeneous material is explained by superposition of deformation and structural transformations of evolutionary type within open nonequilibrium systems. Due to this the description of deformation and failure of rock is related to hierarchy of instabilities within the system being far from thermodynamic equilibrium. It is generally recognized, that the energy function of the current stress-strain state is a superposition of potential component and disturbance, which includes the imperfection parameter accounting for defects not only existing in the initial state, but also appearing under load. The equation of state has been obtained by minimizing the energy function by the order parameter. The imperfection parameter is expressed through the strength deterioration, which is viewed as the internal parameter of state. The evolution of strength deterioration has been studied with the help of Fokker – Planck equation, which steady form corresponds to rock statical stressing. Here the diffusion coefficient is assumed to be constant, while the function reflecting internal sliding and loosening of the geomaterials is assumed as an antigradient of elementary integration catastrophe. Thus the equation of state is supplemented with a correlation establishing relationship between parameters of imperfection and strength deterioration. While deformation process is identified with the change of dissipative media, coupled with irreversible structural fluctuations. Theoretical studies are proven with experimental data obtained by subjecting certain rock specimens to compression.

  1. Compressibility of granulated rock salt

    Energy Technology Data Exchange (ETDEWEB)

    Stinebaugh, R.E.

    1979-08-01

    Crushed rock salt will be used extensively at the Waste Isolation Pilot Plant as a material for backfilling underground openings. This document addresses one of the characteristics of crushed salt which must be known to assess the consequences of its usage, namely, compressibility.

  2. Wettability of Chalk and Argillaceous Sandstones Assessed from T1/T2 Ratio

    OpenAIRE

    Katika, Konstantina; Saidian, M.; Fabricius, Ida Lykke

    2016-01-01

    Low-field NMR relaxation of the fluids inside the porous rock is the result of bulk and surface relaxation of the protons inside the pore fluid. Bulk relaxation is a fluid property when the solid-fluid interaction is minimized. Surface relaxation is the result of the solid-fluid interaction related to mineral properties. Thus, longitudinal, T1, and transverse, T2, relaxation times should in principle be similar. However, microscopic magnetic gradients related to minerals can shorten T2 as com...

  3. Effect of polar organic components on wettability as studied by adsorption and contact angles

    Energy Technology Data Exchange (ETDEWEB)

    Standal, S.; Haavik, J.; Blokhus, A.M. [Department of Chemistry, University of Bergen, Allegaten 41, 5007 Bergen (Norway); Skauge, A. [Norsk Hydro Research Centre, Bergen (Norway)

    1999-12-01

    Adsorption of polar organic components onto the rock surface is one of the mechanisms that is believed to cause wetting alteration of a reservoir rock. Polar compounds in crude oil that are believed to be responsible for surface interactions and wetting properties include carboxylic and phenolic acids, organic bases and metal complexes. Known compounds, representative of these naturally occurring polar organic compounds in crude oil, have been chosen for adsorption and contact angle studies. Contact angles and adsorption isotherms in solid-oil-brine model systems have been examined as a function of component concentration in either water or oil and of salinity and pH of the water phase. The systems investigated consist of isooctane oil phase and water solutions of NaCl and CaCl{sub 2} as the water phase. Silicate glass and {alpha}-alumina were used as solid phases. The polar compounds were 1-naphtoic acid, 5-indanol, quinoline, vanadyl-octaethyl-porphyrin (VO OEP) and dihydrogen-octaethyl-porphyrin (H{sub 2} OEP). The compounds chosen represent functionalities that are found in polar crude oil fractions, such as asphaltenes, but still can be considered well-defined model substances. The components were adsorbed from the oil phase as well as from the water phase, both for contact angle and adsorption isotherm experiments. The results demonstrate the difference in adsorption behaviour between compounds with different functional groups of varying polarity and acidity. The importance of solid-solute interactions compared to solvent-solute interactions is demonstrated.

  4. Effect of Temperature, Wettability and Relative Permeability on Oil Recovery from Oil-wet Chalk

    Directory of Open Access Journals (Sweden)

    Omid Karoussi

    2008-07-01

    Full Text Available It is customary, for convenience, to use relative permeability data produced at room temperature. This paper shows that this practice underestimates oil recovery rates and ultimate recovery from chalk rocks for high temperature reservoirs. Above a certain temperature (80°C in this work a reduction of oil recovery was observed. The reduction in oil recovery is reflected by the shift of relative permeability data towards more oil-wet at high temperature (tested here 130°C. However, both IFT and contact angle measurements indicate an increase in water wetness as temperature increases, which contradict the results obtained by relative permeability experiments. This phenomenon may be explained based on the total interaction potential, which basically consists of van der Waals attractive and short-range Born repulsive and double layer electrostatic forces. The fluid/rock interactions is shown to be dominated by the repulsive forces above 80°C, hence increase fine detachment enhancing oil trapping. In other words the indicated oil wetness by relative permeability is misleading.

  5. Regulation of ROCK Activity in Cancer

    DEFF Research Database (Denmark)

    Morgan-Fisher, Marie; Wewer, Ulla M; Yoneda, Atsuko

    2013-01-01

    regulators of the actin cytoskeleton acting downstream of the small GTPase Rho. ROCK is associated with cancer progression, and ROCK protein expression is elevated in several types of cancer. ROCKs exist in a closed, inactive conformation under quiescent conditions, which is changed to an open, active......, these findings demonstrate additional modes to regulate ROCK activity. This review describes the molecular mechanisms of ROCK activity regulation in cancer, with emphasis on ROCK isoform-specific regulation and interaction partners, and discusses the potential of ROCKs as therapeutic targets in cancer.......Cancer-associated changes in cellular behavior, such as modified cell-cell contact, increased migratory potential, and generation of cellular force, all require alteration of the cytoskeleton. Two homologous mammalian serine/threonine kinases, Rho-associated protein kinases (ROCK I and II), are key...

  6. Rock glaciers, Central Andes, Argentina, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — Primary rock glaciers are fed by avalanche chutes. At the El Salto rock glacier, surveys have been undertaken in order to determine the creep rate. Between 1981 and...

  7. Rock Slope Design Criteria : Executive Summary Report

    Science.gov (United States)

    2010-06-01

    Based on the stratigraphy and the type of slope stability problems, the flat lying, Paleozoic age, sedimentary rocks of Ohio were divided into three design units: 1) competent rock design unit consisting of sandstones, limestones, and siltstones that...

  8. NUMERICAL MODELLING OF DISCONTINUOUS ROCK MASS IN THE ELASTIC DOMAIN

    Directory of Open Access Journals (Sweden)

    Biljana Kovačević-Zelić

    1995-12-01

    Full Text Available Constitutive relationships of rock materials are an important component of the numerical modelling, it is not possible to find a generally acceptable constitutive law for rock materials, because of their complex nature. In this paper, the applicability of some models within the framework of theory of elasticity are examined. The analyses are carried out using next models: isotropic and transversely isotropic model, and 'equivalent' material approach The parametric study is also made to examine the influence of discontinuities on the parameters of the equivalent materials the comparison of above mentioned models is made through numerical modelling of the direct shear test. The analysis were performed with finite difference code FLAC (the paper is published in Croatian.

  9. The Lower Paleozoic rock units in Egypt: An overview

    Directory of Open Access Journals (Sweden)

    H.A. Wanas

    2011-10-01

    Integrated stratigraphic and sedimentological studies of the Lower Paleozoic rocks permit reconstruction of the paleogeography of Egypt at that time. Egypt has been largely controlled since the Cambrian by the pre-existing structural framework of the pre-Phanerozoic basement rocks inherited from the Late Proterozoic Pan-African event. Additionally, sedimentation processes were controlled during Cambro-Ordovician times by tectonic movements, whereas glacio-eustatic control predominated during the Late Ordovician–Silurian Period. These studies suggest that most areas of Egypt were exposed lands with episodically transgression by epi-continental seas related to the paleo-Tethys. These lands formed a part of a stable subsiding shelf at the northern Gondwana margin.

  10. Prehistoric Rock Structures of the Idaho National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Brenda R Pace

    2007-04-01

    Over the past 13,500 years, human populations have lived in and productively utilized the natural resources offered by the cold desert environment of the northeastern Snake River Plain in eastern Idaho. Within an overall framework of hunting and gathering, groups relied on an intimate familiarity with the natural world and developed a variety of technologies to extract the resources that they needed to survive. Useful items were abundant and found everywhere on the landscape. Even the basaltic terrain and the rocks, themselves, were put to productive use. This paper presents a preliminary classification scheme for rock structures built on the Idaho National Laboratory landscape by prehistoric aboriginal populations, including discussions of the overall architecture of the structures, associated artifact assemblages, and topographic placement. Adopting an ecological perspective, the paper concludes with a discussion of the possible functions of these unique resources for the desert populations that once called the INL home.

  11. Correlation chart of Pennsylvanian rocks in Alabama, Tennessee, Kentucky, Virginia, West Virginia, Ohio, Maryland, and Pennsylvania showing approximate position of coal beds, coal zones, and key stratigraphic units: Chapter D.2 in Coal and petroleum resources in the Appalachian basin: distribution, geologic framework, and geochemical character

    Science.gov (United States)

    Ruppert, Leslie F.; Trippi, Michael H.; Slucher, Ernie R.; Ruppert, Leslie F.; Ryder, Robert T.

    2014-01-01

    The Appalachian basin, one of the largest Pennsylvanian bituminous coal-producing regions in the world, currently contains nearly one-half of the top 15 coal-producing States in the United States (Energy Information Agency, 2006). Anthracite of Pennsylvanian age occurs in synclinal basins in eastern Pennsylvania, but production is minimal. A simplified correlation chart was compiled from published and unpublished sources as a means of visualizing currently accepted stratigraphic relations between the rock formations, coal beds, coal zones, and key stratigraphic units in Alabama, Tennessee, Kentucky, Virginia, West Virginia, Ohio, Maryland, and Pennsylvania. The thickness of each column is based on chronostratigraphic divisions (Lower, Middle, and Upper Pennsylvanian), not the thickness of strata. Researchers of Pennsylvanian strata in the Appalachian basin also use biostratigraphic markers and other relative and absolute geologic age associations between the rocks to better understand the spatial relations of the strata. Thus, the stratigraphic correlation data in this chart should be considered provisional and will be updated as coal-bearing rocks within the Appalachian coal regions continue to be evaluated.

  12. Rock-degrading endophytic bacteria in cacti

    Science.gov (United States)

    M. Esther Puente; Ching Y. Li; Yoav Bashan

    2009-01-01

    A plant-bacterium association of the cardon cactus (Pachycereus pringlei) and endophytic bacteria promotes establishment of seedlings and growth on igneous rocks without soil. These bacteria weather several rock types and minerals, unbind significant amounts of useful minerals for plants from the rocks, fix in vitro N2. produce...

  13. Upper limb injuries associated with rock climbing.

    Science.gov (United States)

    Bannister, P; Foster, P

    1986-01-01

    Four cases of upper limb injuries secondary to rock-climbing or training for rock climbing are presented. All four cases had diagnosis and treatment delayed because of unawareness of the range of injuries seen in high grade rock climbing. PMID:3730754

  14. An ecological dynamics framework for the acquisition of perceptual-motor skills in climbing

    NARCIS (Netherlands)

    Seifert, Ludovic; Orth, Dominic; Button, Chris; Brymer, Eric; Davids, Keith

    2016-01-01

    Uncertainty in extreme sports performance environments, like rock and ice climbing, provides considerable psycho-emotional and physiological demands which challenge the acquisition of perceptual-motor skills. An ecological dynamics theoretical framework adopts concepts and tools of nonlinear

  15. Mechanism of Rock Burst Occurrence in Specially Thick Coal Seam with Rock Parting

    Science.gov (United States)

    Wang, Jian-chao; Jiang, Fu-xing; Meng, Xiang-jun; Wang, Xu-you; Zhu, Si-tao; Feng, Yu

    2016-05-01

    Specially thick coal seam with complex construction, such as rock parting and alternative soft and hard coal, is called specially thick coal seam with rock parting (STCSRP), which easily leads to rock burst during mining. Based on the stress distribution of rock parting zone, this study investigated the mechanism, engineering discriminant conditions, prevention methods, and risk evaluation method of rock burst occurrence in STCSRP through setting up a mechanical model. The main conclusions of this study are as follows. (1) When the mining face moves closer to the rock parting zone, the original non-uniform stress of the rock parting zone and the advancing stress of the mining face are combined to intensify gradually the shearing action of coal near the mining face. When the shearing action reaches a certain degree, rock burst easily occurs near the mining face. (2) Rock burst occurrence in STCSRP is positively associated with mining depth, advancing stress concentration factor of the mining face, thickness of rock parting, bursting liability of coal, thickness ratio of rock parting to coal seam, and difference of elastic modulus between rock parting and coal, whereas negatively associated with shear strength. (3) Technologies of large-diameter drilling, coal seam water injection, and deep hole blasting can reduce advancing stress concentration factor, thickness of rock parting, and difference of elastic modulus between rock parting and coal to lower the risk of rock burst in STCSRP. (4) The research result was applied to evaluate and control the risk of rock burst occurrence in STCSRP.

  16. Wettability of natural root mucilage studied by atomic force microscopy and contact angle: Links between nanoscale and macroscale surface properties

    Science.gov (United States)

    Kaltenbach, Robin; Diehl, Dörte; Schaumann, Gabriele E.

    2017-04-01

    Organic coatings are considered as main cause of soil water repellency (SWR). This phenomenon plays a crucial role in the rhizosphere, at the interface of plant water uptake and soil hydraulics. Still, there is little knowledge about the nanoscale properties of natural soil compounds such as root-mucilage and its mechanistic effect on wettability. In this study, dried films of natural root-mucilage from Sorghum (Sorghum sp., MOENCH) on glass substrates were studied in order to explore experimental and evaluation methods that allow to link between macroscopic wettability and nano-/microscopic surface properties in this model soil system. SWR was assessed by optical contact angle (CA) measurements. The nanostructure of topography and adhesion forces of the mucilage surfaces was revealed by atomic force microscopy (AFM) measurements in ambient air, using PeakForce Quantitative Nanomechanical Mapping (PFQNM). Undiluted mucilage formed hydrophobic films on the substrate with CA > 90° and rather homogeneous nanostructure. Contact angles showed reduced water repellency of surfaces, when concentration of mucilage was decreased by dilution. AFM height and adhesion images displayed incomplete mucilage surface coverage for diluted samples. Hole-like structures in the film frequently exhibited increased adhesion forces. Spatial analysis of the AFM data via variograms enabled a numerical description of such 'adhesion holes'. The use of geostatistical approaches in AFM studies of the complex surface structure of soil compounds was considered meaningful in view of the need of comprehensive analysis of large AFM image data sets that exceed the capability of comparative visual inspection. Furthermore, force curves measured with the AFM showed increased break-free distances and pull-off forces inside the observed 'adhesion holes', indicating enhanced capillary forces due to adsorbed water films at hydrophilic domains for ambient RH (40 ± 2 %). This offers the possibility of

  17. Application of photo-excitation reaction on titanium oxide thin film for control of wettability; Sanka chitann hakumakujo no hikari reiki hanno no nuresei seigyo eno oyo

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, T.; Nakajima, A.; Hashimoto, K. [The Univ. of Tokyo, Tokyo (Japan); Takada, Y. [Kyushu Univ., Fukuoka (Japan)

    2000-03-31

    It is clarified that the photo-excitation hydrophilic reaction increasing wettability remarkably is induced by changing surface structure of titanium oxide radiated light. There are already many examples being in practical use of coating products applied hydrophilic reaction of titanium oxide surface such as drip-proof side millers for automobiles, self-cleaning building materials, and the like. When surface of titanium oxide having high activities for oxidisation and decomposition is coated organic materials and radiated light, wettability of surface changes as organic materials are decomposed. If it is possible to change wettability shaping pattern drastically by radiating light, the possibility of application for printing materials will be developed. After increasing contact angle by coating water and oil repellent on the titanium oxide thin film, images can be shaped by radiating light into pattern for changing surface of titanium oxide to be ultra hydrophilicity as decomposition of repellent. At that time, contact angle is 150 degree in water, 80 degree in oil, for not radiated aria, and is 0 degree in water and oil for radiated aria. Application for control technology of wettability keeps possibility of broader development to itself, not staying ability of self-cleaning and drip-proof. (NEDO)

  18. Impact of viscous droplets on different wettable surfaces: Impact phenomena, the maximum spreading factor, spreading time and post-impact oscillation.

    Science.gov (United States)

    Lin, Shiji; Zhao, Binyu; Zou, Song; Guo, Jianwei; Wei, Zheng; Chen, Longquan

    2017-12-30

    In this paper, we experimentally investigated the impact dynamics of different viscous droplets on solid surfaces with diverse wettabilities. We show that the outcome of an impinging droplet is dependent on the physical property of the droplet and the wettability of the surface. Whereas only deposition was observed on lyophilic surfaces, more impact phenomena were identified on lyophobic and superlyophobic surfaces. It was found that none of the existing theoretical models can well describe the maximum spreading factor, revealing the complexity of the droplet impact dynamics and suggesting that more factors need to be considered in the theory. By using the modified capillary-inertial time, which considers the effects of liquid viscosity and surface wettability on droplet spreading, a universal scaling law describing the spreading time was obtained. Finally, we analyzed the post-impact droplet oscillation with the theory for damped harmonic oscillators and interpreted the effects of liquid viscosity and surface wettability on the oscillation by simple scaling analyses. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Imaging of rock climbing injuries.

    Science.gov (United States)

    Martinoli, Carlo; Bianchi, Stefano; Cotten, Anne

    2005-12-01

    Competition climbing has grown increasingly in popularity, and many people are being drawn to this sport with a parallel increase in the occurrence of sport-related injuries. One of the most common and unique lesions occurring in the rock climbing population is the closed rupture of the flexor pulley system of the fingers. This lesion is strictly related to some climbing techniques in which the entire body weight is placed on fingerholds, which causes bowstringing of the flexor tendons with subsequent loss of strength across the full range of motion of the finger. This article summarizes the current literature regarding the application of imaging modalities in the diagnosis of rock climbing injuries with a specific focus on ultrasound and magnetic resonance imaging. Biomechanics of the sporting activity and resultant pathophysiologic and clinical considerations concerning flexor pulley system injuries are also discussed.

  20. ESR dating of fault rocks

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hee Kwon [Kangwon National Univ., Chuncheon (Korea, Republic of)

    2002-03-15

    Past movement on faults can be dated by measurement of the intensity of ESR signals in quartz. These signals are reset by local lattice deformation and local frictional heating on grain contacts at the time of fault movement. The ESR signals then trow back as a result of bombardment by ionizing radiation from surrounding rocks. The age is obtained from the ratio of the equivalent dose, needed to produce the observed signal, to the dose rate. Fine grains are more completely reset during faulting, and a plot of age vs grain size shows a plateau for grains below critical size : these grains are presumed to have been completely zeroed by the last fault activity. We carried out ESR dating of fault rocks collected from the Yangsan fault system. ESR dates from the this fault system range from 870 to 240 ka. Results of this research suggest that long-term cyclic fault activity continued into the pleistocene.

  1. Toppling analysis of the Echo Cliffs precariously balanced rock

    Science.gov (United States)

    Veeraraghavan, Swetha; Hudnut, Kenneth W.; Krishnan, Swaminathan

    2017-01-01

    Toppling analysis of a precariously balanced rock (PBR) can provide insight into the nature of ground motion that has not occurred at that location in the past and, by extension, can constrain peak ground motions for use in engineering design. Earlier approaches have targeted 2D models of the rock or modeled the rock–pedestal contact using spring‐damper assemblies that require recalibration for each rock. Here, a method to model PBRs in 3D is presented through a case study of the Echo Cliffs PBR. The 3D model is created from a point cloud of the rock, the pedestal, and their interface, obtained using terrestrial laser scanning. The dynamic response of the model under earthquake excitation is simulated using a rigid‐body dynamics algorithm. The veracity of this approach is demonstrated through comparisons against data from shake‐table experiments. Fragility maps for toppling probability of the Echo Cliffs PBR as a function of various ground‐motion parameters, rock–pedestal interface friction coefficient, and excitation direction are presented. These fragility maps indicate that the toppling probability of this rock is low (less than 0.2) for peak ground acceleration (PGA) and peak ground velocity (PGV) lower than 3  m/s2 and 0.75  m/s, respectively, suggesting that the ground‐motion intensities at this location from earthquakes on nearby faults have most probably not exceeded the above‐mentioned PGA and PGV during the age of the PBR. Additionally, the fragility maps generated from this methodology can also be directly coupled with existing probabilistic frameworks to obtain direct constraints on unexceeded ground motion at a PBR’s location.

  2. Thermophysical Properties of Selected Rocks.

    Science.gov (United States)

    1974-04-01

    phase, pure substances exemplified by many metals , elemental materials, and certain man-made and natural compounds for which thermophysical properties...for Dresser basalt. Specific Heat. Heat content studies of Krawza and Lindroth [351 indicate a distinct phase transition near 848 K, near a-# quartz...0.08 Chlorite (secondary) 0.05 Chalcopyrite 0.02 Texture. The rock is medium-grained and has a hypidiomorphic granular texture. Average grain diameter

  3. 20020113: Rock (1), panel (1)

    OpenAIRE

    None

    2002-01-01

    Rock Art photograph, Panel 1, glyph [cam element='coordinate' qualifier='longitude']W 70deg34'55.9"[/cam][cam element='coordinate' qualifier='latitude']S 32deg49'49.0"[/cam][cam element='coordinate' qualifier='altitude']924[/cam][cam element='coordinate' qualifier='bearing']125[/cam][cam element='coordinate' qualifier='inclination']0[/cam][cam element='coordinate' qualifier='cartesian'](1.950,1.640,2.190)[/cam

  4. Martian rocks, minerals, and mantles

    OpenAIRE

    Albee, Arden

    2002-01-01

    The variable nature of Mars was first observed almost 400 years ago and modern observations began almost 40 years ago, culminating with the flotilla of spacecraft now at or heading for Mars. We now know that the atmosphere, which produced the visible variation of Mars, has also covered it with a mantle that makes difficult any detailed investigation of the rocks and minerals of Mars.

  5. The impact of mechanical properties of rock to the collision of rock piece

    Directory of Open Access Journals (Sweden)

    Borut Macuh

    2007-06-01

    Full Text Available The paper presents the analytical solution of the rock piece motion considering influences of geometrical and mechanical characteristics of rock mass on the arbitrary slope. The main objective of the paper is to determine the motion of the rock piece considering possibility of rock piece failure due to collision. Brief description of the analytical solution of the rock piece motion on a steep slope is given. The laboratory tests were performed to determine uniaxial compressive strength and elastic properties of the considered rock mass. Further, velocities that cause rock piece failure were determined. These maximum velocities indirectly belong to certain mass of rock piece and can be lower than velocities calculated in rock-fall analysis for certain slope geometry. Consequently, the energy magnitude is limited, because at certain velocity and mass of rock piece bigger pieces crash at collision.

  6. ESR dating of fault rocks

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hee Kwon [Kangwon National Univ., Chuncheon (Korea, Republic of)

    2003-02-15

    Past movement on faults can be dated by measurement of the intensity of ESR signals in quartz. These signals are reset by local lattice deformation and local frictional heating on grain contacts at the time of fault movement. The ESR signals then grow back as a result of bombardment by ionizing radiation from surrounding rocks. The age is obtained from the ratio of the equivalent dose, needed to produce the observed signal, to the dose rate. Fine grains are more completely reset during faulting, and a plot of age vs. grain size shows a plateau for grains below critical size; these grains are presumed to have been completely zeroed by the last fault activity. We carried out ESR dating of fault rocks collected near the Gori nuclear reactor. Most of the ESR signals of fault rocks collected from the basement are saturated. This indicates that the last movement of the faults had occurred before the Quaternary period. However, ESR dates from the Oyong fault zone range from 370 to 310 ka. Results of this research suggest that long-term cyclic fault activity of the Oyong fault zone continued into the Pleistocene.

  7. The physical principles of rock magnetism

    CERN Document Server

    Stacey, Frank

    1974-01-01

    Developments in Solid Earth Geophysics 5: The Physical Principles of Rock Magnetism explores the physical principles of rock magnetism, with emphasis on the properties of finely divided magnetic materials. It discusses the origin and stability of rock magnetizations, the role of remanent magnetism in interpreting magnetic surveys, magnetic anisotropy as an indicator of rock fabric, and the relationship between piezomagnetic changes and seismic activity. Organized into 13 chapters, this volume discusses the properties of solids, magnetite and hematite grains, and rocks with magnetite grains

  8. Exploration of Wettability and Optical Aspects of ZnO Nano Thin Films Synthesized by Radio Frequency Magnetron Sputtering

    Directory of Open Access Journals (Sweden)

    Kartik H. Patel

    2016-03-01

    Full Text Available This paper aims to explore structural, optical and wettabil‐ ity aspects of zinc oxide (ZnO nano thin films prepared by radio frequency (RF magnetron sputtering. The deposition time is varied from 10 to 50 minutes and sputtering pressure from 0.5 to 8.0 Pa. The increase of deposition time from 10 to 50 minutes leads to formation of a single (002 peak for ZnO films; (100, (101 and (110 peaks are not observed under these conditions. The intensity for (100, (002, (101 and (110 peaks decreases with a sputtering pressure value of 3.5 Pa and above. The optical transmis‐ sion and band gaps are measured by a UV-Vis-NIR spectrophotometer. The wettability and contact-angle hysteresis (CAH for deposited ZnO nano thin films are investigated for water, ethylene glycol, sunflower oil and formamide using a contact-angle goniometer.

  9. The Effect of Reflow on Wettability of Sn 96.5 Ag 3 Cu 0.5 Solder

    Directory of Open Access Journals (Sweden)

    Zoltán Weltsch

    2012-11-01

    Full Text Available Surface conditions on Printed Circuit Board (PCB final finishes have an important impact on the wetting behaviour with lead-free solder. The improvement of wettability in liquid Sn 96.5 Ag 3 Cu 0.5 Solder alloy on PCB substrate was measured with a sessile drop method at 523 K temperature. Wetting properties was determined in normal atmospheric air and inert atmosphere. The wetting angles increasing with the number of reflows both atmosphere. The effect of the atmosphere has a huge importance of the oxidation which manifests itself of the measured wetting angles. One of the most important factors to the wetting properties is the amount of oxygen in the soldering atmosphere. Using the inert atmosphere is crucial to Pb-free solders, particularly after reflows.

  10. THE EFFECT OF REFLOW ON WETTABILITY OF Sn 96.5 Ag 3 Cu 0.5 SOLDER

    Directory of Open Access Journals (Sweden)

    Zoltán Weltsch

    2012-12-01

    Full Text Available Surface conditions on Printed Circuit Board (PCB final finishes have an important impact on the wetting behavior with lead-free solder. The improvement of the wettability in liquid Sn 96.5 Ag 3 Cu 0.5 Solder alloy on PCB substrate was measured with a sessile drop method at 523 K temperature. Wetting properties were determined in normal atmospheric air and inert atmosphere. The wetting angles increasing with the number of reflows both atmosphere. The effect of the atmosphere has a huge importance of the oxidation which manifests itself of the measured wetting angles. One of the most important factors affecting the wetting properties is the amount of oxygen in the soldering atmosphere. Using the inert atmosphere is crucial in case of Pb-free solders, particularly after reflows.

  11. Corrosion Resistance, EIS and Wettability of the Implants Made of 316 LVM Steel Used in Chest Deformation Treatment

    Directory of Open Access Journals (Sweden)

    Kajzer A.

    2016-06-01

    Full Text Available The paper presents the influence of mechanical surface damage on the physicochemical properties of plates after implantation made of CrNiMo stainless steel, used in the treatment of anterior surface deformity of the chest. Analysis of the data allowed us to investigate the effect of implant design and condition of their surface on the results of chest deformation treatment. Results of electrochemical, impedance and surface wettability tests and SEM observations were compared with clinical observations. When removing the plates we found only slight inflammatory-periosteal reactions. On the basis of obtained results, it can be stated that plates, in spite of mechanical damage of the surface, were characterized by good corrosion resistance, a fact which is confirmed by the results of clinical evaluation.

  12. Wettability of Surface on Aluminum Alloy Based on Laser Micro-textured and Self-assembled Technique

    Directory of Open Access Journals (Sweden)

    LI Jie

    2018-01-01

    Full Text Available Micron texture was first introduced on aluminum alloy substrate by laser manufacturing. Subsequently,perfluorodecyltrichlorosilane(FDTS was deposited on these surfaces by nanocoating technology through a self-assembly route to form hydrophobic/superhydrophobic aluminum alloy surface. Scanning electron microscope, surface profiler and contact angle measurement were used to characterize the surface properties, and wettability of specimens. The results indicate that the joint action of micron level rough structure of microtexture by laser manufacturing and SAMs plays an important role in preparing superhydrophobic surface. Contact angle of the water droplet on the substrate increases with pitch decreasing(50-100μm,and is related to the type of laser microtexture. The carrying capacity experiments of floating platform show that superhydrophobic surface is in accord with the Cassie-Baxter model state, and can effectively improve the carrying capacity of the floating platform.

  13. Technique for characterization of the wettability properties of gas diffusion media for proton exchange membrane fuel cells.

    Science.gov (United States)

    Gurau, Vladimir; Mann, J Adin

    2010-10-15

    In this paper, a measurement technique based on the capillary penetration method is presented for use in estimating the wettability properties of gas diffusion media (GDM), a component for proton exchange membrane fuel cells (PEMFCs). The present method solves several critical issues, including the formation of an external meniscus and the evaporation of imbibed solvent, both of which greatly affect the apparent rate of solvent imbibition. Solvent evaporation is prevented by inserting a GDM sample between two thin stainless steel plates to form a tri-layer structure having non-porous evaporation covers on each side of the porous GDM sample. The presence of stainless steel plates in contact with the GDM sample was demonstrated to have a negligible impact on the evaluation of the Washburn material constant. Copyright 2010 Elsevier Inc. All rights reserved.

  14. Aging effects on the microstructure, surface characteristics and wettability of Cu pretinned with Sn-Pb solders

    Energy Technology Data Exchange (ETDEWEB)

    Linch, Heidi Sue [Univ. of California, Berkeley, CA (United States)

    1993-11-01

    This study investigates effects of aging in air and argon at 170 C on Cu coupons which were pretinned with 75Sn-25Pb, 8Sn-92Pb, and 5Sn-95Pb solders. Coatings were applied using electroplating or hot dipping techniques. The coating thickness was controlled between 3 to 3μm and the specimens were aged for 0 hours, 2 hours, 24 hours and 2 weeks. Wetting balance tests were used to evaluate the wettability of the test specimens. Microstructural development was evaluated using X-ray diffraction, energy dispersive X-ray and Auger spectroscopy, as well as optical and scanning electron microscopy. The wetting behavior of the test specimens is interpreted with respect to observed microstructural changes and as a function of aging time, solder composition, and processing conditions.

  15. Multiscale properties of unconventional reservoir rocks

    Science.gov (United States)

    Woodruff, W. F.

    A multidisciplinary study of unconventional reservoir rocks is presented, providing the theory, forward modeling and Bayesian inverse modeling approaches, and laboratory protocols to characterize clay-rich, low porosity and permeability shales and mudstones within an anisotropic framework. Several physical models characterizing oil and gas shales are developed across multiple length scales, ranging from microscale phenomena, e.g. the effect of the cation exchange capacity of reactive clay mineral surfaces on water adsorption isotherms, and the effects of infinitesimal porosity compaction on elastic and electrical properties, to meso-scale phenomena, e.g. the role of mineral foliations, tortuosity of conduction pathways and the effects of organic matter (kerogen and hydrocarbon fractions) on complex conductivity and their connections to intrinsic electrical anisotropy, as well as the macro-scale electrical and elastic properties including formulations for the complex conductivity tensor and undrained stiffness tensor within the context of effective stress and poroelasticity. Detailed laboratory protocols are described for sample preparation and measurement of these properties using spectral induced polarization (SIP) and ultrasonics for the anisotropic characterization of shales for both unjacketed samples under benchtop conditions and jacketed samples under differential loading. An ongoing study of the effects of kerogen maturation through hydrous pyrolysis on the complex conductivity is also provided in review. Experimental results are catalogued and presented for various unconventional formations in North America including the Haynesville, Bakken, and Woodford shales.

  16. Rock Magnetism: Successes and Mysteries

    Science.gov (United States)

    Dunlop, D. J.

    2011-12-01

    Louis Néel once proposed making ships "invisible" (i.e., magnetically undetectable) by giving them a permanent or remanent magnetism that would cancel the signal induced by the Earth's magnetic field. Like much of rock magnetism, this borders on the magical. Rocks possess a magnetic memory that verges on the phenomenal. An adequate magnetic lifetime for your credit card is until its expiry date and one must avoid exposure to magnetic fields and heat. But a rock's magnetic memory is forever, and the recipe for that durability includes, for igneous and metamorphic rocks, exposure to ancient fields while hot - near the Curie temperature in fact. The thermal remanent magnetism (TRM) thus produced is largely immune to later field changes at lower temperatures although luckily a fraction - a partial TRM overprint - does record later heating events, e.g., burial during major orogenies. When we lift the veil and look closely, on a microscale or nanoscale, it is perplexing to understand why paleomagnetism works so well when rocks seemingly contain so few of Néel's ideal recorders: single-domain grains with tightly coupled atomic spins. In larger grains with multiple domains, the walls between neighbouring domains move readily, like dislocations in crystals, enlarging some domains at the expense of others. This mutability makes any magnetic memory of multi-domain grains suspect. But around the threshold between single-domain and multi-domain structures - a specific grain size that varies widely from one magnetic mineral to another - there are recent predictions and observations of novel structures, including linked magnetic moments of nearby grains and interfacial moments of exsolved phases, that could go some way towards explaining why single-domain-like behaviour is so widespread. Many magnetic properties show an almost continuous variation with grain size, quite unlike the expected discontinuity at the single-domain threshold. Among these is initial susceptibility which

  17. Wettability of Y2O3: A Relative Analysis of Thermally Oxidized, Reactively Sputtered and Template Assisted Nanostructured Coatings

    Directory of Open Access Journals (Sweden)

    Natarajan T. Manikandanath

    2012-02-01

    Full Text Available The wettability of reactively sputtered Y2O3, thermally oxidized Y-Y2O3 and Cd-CdO template assisted Y2O3 coatings has been studied. The wettability of as-deposited Y2O3 coatings was determined by contact angle measurements. The water contact angles for reactively sputtered, thermally oxidized and template assisted Y2O3 nanostructured coatings were 99°, 117° and 155°, respectively. The average surface roughness values of reactively sputtered, thermally oxidized and template assisted Y2O3 coatings were determined by using atomic force microscopy and the corresponding values were 3, 11 and 180 nm, respectively. The low contact angle of the sputter deposited Y2O3 and thermally oxidized Y-Y2O3 coatings is attributed to a densely packed nano-grain like microstructure without any void space, leading to low surface roughness. A water droplet on such surfaces is mostly in contact with a solid surface relative to a void space, leading to a hydrophobic surface (low contact angle. Surface roughness is a crucial factor for the fabrication of a superhydrophobic surface. For Y2O3 coatings, the surface roughness was improved by depositing a thin film of Y2O3 on the Cd-CdO template (average roughness = 178 nm, which resulted in a contact angle greater than 150°. The work of adhesion of water was very high for the reactively sputtered Y2O3 (54 mJ/m2 and thermally oxidized Y-Y2O3 coatings (43 mJ/m2 compared to the Cd-CdO template assisted Y2O3 coating (7 mJ/m2.

  18. Effect of wettability on two-phase quasi-static displacement: validation of two pore scale modeling approaches

    KAUST Repository

    Verma, Rahul

    2018-01-06

    Understanding of pore-scale physics for multiphase flow in porous media is essential for accurate description of various flow phenomena. In particular, capillarity and wettability strongly influence capillary pressure-saturation and relative permeability relationships. Wettability is quantified by the contact angle of the fluid-fluid interface at the pore walls. In this work we focus on the non-trivial interface equilibria in presence of non-neutral wetting and complex geometries. We quantify the accuracy of a volume-of-fluid (VOF) formulation, implemented in a popular open-source computational fluid dynamics code, compared with a new formulation of a level set (LS) method, specifically developed for quasi-static capillarity-dominated displacement. The methods are tested in rhomboidal packings of spheres for a range of contact angles and for different rhomboidal configurations and the accuracy is evaluated against the semi-analytical solutions obtained by Mason and Morrow (1994). While the VOF method is implemented in a general purpose code that solves the full Navier-Stokes (NS) dynamics in a finite volume formulation, with additional terms to model surface tension, the LS method is optimised for the quasi-static case and, therefore, less computationally expensive. To overcome the shortcomings of the finite volume NS-VOF system for low capillary number flows, and its computational cost, we introduce an overdamped dynamics and a local time stepping to speed up the convergence to the steady state, for every given imposed pressure gradient (and therefore saturation condition). Despite these modifications, the methods fundamentally differ in the way they capture the interface, as well as in the number of equations solved and in the way the mean curvature (or equivalently capillary pressure) is computed. This study is intended to provide a rigorous validation study and gives important indications on the errors committed by these methods in solving more complex geometry

  19. ZEND FRAMEWORK

    Directory of Open Access Journals (Sweden)

    Lupasc Adrian

    2013-12-01

    Full Text Available In this paper we present Zend Architecture, which is an open source technology for developing web applications and services, based on object-oriented components, and the Model-View-Controller architectural pattern, also known as MVC, which is the fundament of this architecture. The MVC presentation emphasises its main characteristics, such as facilitating the components reuse by dividing the application into distinct interconnected modules, tasks distribution in the process of developing an application, the MVC life cycle and also the essential features of the components in which it separates the application: model, view, controller. The controller coordinates the models and views and it’s responsible with manipulating the user events through the corresponding actions. The model contains application rules, respectively the scripts that implement the database manipulation. The third component, the view represents the controllers interface with the user or the way it displays the response to the event triggered by the user. Another aspect treated in this paper consists in highlighting the Zend architecture advantages and disadvantages. Among the framework advantages, we can enumerate good code organization, due to its delimitation into three sections, presentation, logic and data access, and dividing the code into components, which facilitates the code reuse and testing. Other advantages are the open-source license and the support for multiple database systems. The main disadvantages are represented by its size and complexity, that makes it hard to understand for a beginner programmer, the resources it needs etc. The last section of the paper presents a comparison between Zend and other PHP architectures, like Symphony, CakePHP and CodeIgniter, which includes their essential features and points out their similarities and differences, based on the unique functions that set them apart from others. The main thing that distinguishes ZF from the

  20. Modeling the proportion of cut slopes rock on forest roads using artificial neural network and ordinal linear regression.

    Science.gov (United States)

    Babapour, R; Naghdi, R; Ghajar, I; Ghodsi, R

    2015-07-01

    Rock proportion of subsoil directly influences the cost of embankment in forest road construction. Therefore, developing a reliable framework for rock ratio estimation prior to the road planning could lead to more light excavation and less cost operations. Prediction of rock proportion was subjected to statistical analyses using the application of Artificial Neural Network (ANN) in MATLAB and five link functions of ordinal logistic regression (OLR) according to the rock type and terrain slope properties. In addition to bed rock and slope maps, more than 100 sample data of rock proportion were collected, observed by geologists, from any available bed rock of every slope class. Four predictive models were developed for rock proportion, employing independent variables and applying both the selected probit link function of OLR and Layer Recurrent and Feed forward back propagation networks of Neural Networks. In ANN, different numbers of neurons are considered for the hidden layer(s). Goodness of the fit measures distinguished that ANN models produced better results than OLR with R (2) = 0.72 and Root Mean Square Error = 0.42. Furthermore, in order to show the applicability of the proposed approach, and to illustrate the variability of rock proportion resulted from the model application, the optimum models were applied to a mountainous forest in where forest road network had been constructed in the past.

  1. Hot Dry Rock; Geothermal Energy

    Energy Technology Data Exchange (ETDEWEB)

    None

    1990-01-01

    The commercial utilization of geothermal energy forms the basis of the largest renewable energy industry in the world. More than 5000 Mw of electrical power are currently in production from approximately 210 plants and 10 000 Mw thermal are used in direct use processes. The majority of these systems are located in the well defined geothermal generally associated with crustal plate boundaries or hot spots. The essential requirements of high subsurface temperature with huge volumes of exploitable fluids, coupled to environmental and market factors, limit the choice of suitable sites significantly. The Hot Dry Rock (HDR) concept at any depth originally offered a dream of unlimited expansion for the geothermal industry by relaxing the location constraints by drilling deep enough to reach adequate temperatures. Now, after 20 years intensive work by international teams and expenditures of more than $250 million, it is vital to review the position of HDR in relation to the established geothermal industry. The HDR resource is merely a body of rock at elevated temperatures with insufficient fluids in place to enable the heat to be extracted without the need for injection wells. All of the major field experiments in HDR have shown that the natural fracture systems form the heat transfer surfaces and that it is these fractures that must be for geothermal systems producing from naturally fractured formations provide a basis for directing the forthcoming but, equally, they require accepting significant location constraints on HDR for the time being. This paper presents a model HDR system designed for commercial operations in the UK and uses production data from hydrothermal systems in Japan and the USA to demonstrate the reservoir performance requirements for viable operations. It is shown that these characteristics are not likely to be achieved in host rocks without stimulation processes. However, the long term goal of artificial geothermal systems developed by systematic

  2. Infiltration Flow Path Distributions in Unsaturated Rocks

    Science.gov (United States)

    Tokunaga, T. K.; Olson, K. R.; Wan, J.

    2004-12-01

    Spatial distributions of infiltration flow paths through rock formations are complex networks that determine flow velocities, control rates of natural geochemical reactions in the subsurface, as well as rates of contaminant transport to underlying groundwater. Despite these important consequences, distributions of infiltration paths and locally fast seepage rates through rocks are not well understood. Laboratory-based studies on fractured rocks cannot easily be conducted on systems large enough to include sufficient fracture network complexity, so that inferences of field-scale flux distributions cannot be reliably made. Field-based studies to date have permitted quantification of only a small fraction of the flow distribution, typically while imposing extremely high fluxes, and therefore have not allowed comprehensive delineation of flow distributions expected under natural recharge. Based on hydraulic scaling considerations, we hypothesize that unsaturated flow path distributions in rock deposits will be similar to those occurring in fractured rock formations under low overall infiltration rates. Talus rock deposits and mine waste rock piles control flow and transport into their respective underlying groundwaters. All of these reasons motivated infiltration experiments in rock packs. Experiments have been conducted on 4 different rock types and system scales ranging from 1 to 46 rock layers. Our experiments showed that infiltration through rocks conforms to no previously reported behavior in soils, and that flow paths do not progressively converge into fewer and fewer flow paths. Instead, a fundamentally different hydraulic structure develops, having an exponential (geometric) flux distribution, with the characteristic scale determined by the characteristic rock size. Although the phenomena are very different, the evolution of flow path distributions and local seepage rate distributions is predictable based on a statistical mechanical model for energy

  3. Punk rock as popular theatre

    OpenAIRE

    Double, Oliver

    2007-01-01

    Punk rock performance consciously draws on popular theatre forms like music hall and\\ud stand-up comedy, as exemplified by the occasion when Max Wall appeared with Ian Dury\\ud at the Hammersmith Odeon. Oliver Double traces the historical and stylistic connections\\ud between punk, music hall and stand-up, and argues that punk shows can be considered a\\ud form of popular theatre in their own right. He examines a wide range of punk bands and\\ud performers- including Sex Pistols, Iggy Pop, Devo, ...

  4. Big Bang Day : Physics Rocks

    CERN Multimedia

    Brian Cox; John Barrowman; Eddie Izzard

    2008-01-01

    Is particle physics the new rock 'n' roll? The fundamental questions about the nature of the universe that particle physics hopes to answer have attracted the attention of some very high profile and unusual fans. Alan Alda, Ben Miller, Eddie Izzard, Dara O'Briain and John Barrowman all have interests in this branch of physics. Brian Cox - CERN physicist, and former member of 90's band D:Ream, tracks down some very well known celebrity enthusiasts and takes a light-hearted look at why this subject can appeal to all of us.

  5. Wettability Effect of PECVD-SiOx Films on Poly(lactic acid) Induced by Oxygen Plasma on Protein Adsorption and Cell Attachment

    Science.gov (United States)

    Sarapirom, S.; Lee, J. S.; Jin, S. B.; Song, D. H.; Yu, L. D.; Han, J. G.; Chaiwong, C.

    2013-04-01

    Surface wettability is an important property of biomaterials. Silicon oxide films have a wide range of applications due to a range of the properties such as the mechanical strength and surface wettability. This paper reports effect of the surface wettability of silicon oxide (SiOx) films on protein adsorption and cell attachment and proliferation. SiOx films were deposited onto poly(lactic acid) (PLA) substrate using plasma enhanced chemical vapor deposition (PECVD). Octamethylcyclotetrasiloxane (OMCTS:Si4O4C8H24) was used as a precursor with O2 as a carrier gas. After deposition, the films were treated with O2-plasma to adapt wettability. It was found that O2-plasma enhanced the wettability of the films without changing the film thickness, while made the surface morphology slightly smoother. The polar component increased after O2-plasma treatment as observed in the contact angle measurements. The surface energy of the films was calculated by means of the Owens-Wendt method to resolve the contributions of polar and dispersive components. The chemical structure was characterized using attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. The films were dense with a high Si-network structure. The reduced carbon content (-CHn, Si-CH3) and increased hydrogen content (-OH) of the O2-plasma treated SiOx films led to the polar components enhancing the SiOx wettability. Adsorption of bovine serum albumin (BSA) on the films was investigated by using x-ray photoelectron spectroscopy (XPS). More BSA was adsorbed onto the O2-plasma treated SiOx films. Attachment and proliferation of MC3T3-E1 mouse pre-osteoblasts and L929 mouse fibroblasts cells on the SiOx films were evaluated via MTT assay. The cells were attached more to the untreated SiOx films but proliferated more on the surface of the O2-plasma treated SiOx films depending on the cell types.

  6. Multiversos: Rock'n'Astronomy

    Science.gov (United States)

    Caballero, J. A.; Arias, A.; García, N.

    2011-11-01

    Imagine that you can use your fingers only for typing target coordinates at thetelescope, reduce images and spectra with IRAF, or write papers for Astronomy &Astrophysics, but you would never be able to play an electric guitar.Imagine that you love music, work in front of the computer always withheadphones, and dream of playing with your favourite rock band in a tumultuousconcert.Imagine that you are an astronomer who, after a "cosmic fluke", share stagewith the band which themes you have always hummed since you were a teenager.Imagine that you were born for rock, played a main role in the best Spanishalbum of the 90s (Omega, with Enrique Morente), and your songs arerutinary played by Radio 3, but you would never be able to detect an exoplanetor a galaxy at a high redshift.Imagine that you love Astronomy, try to see the Moon craters and Andromeda withyour small telescope through the light pollution of your city, and explain yourdaughter that Pluto is not a planet any longer. Imagine that you are a musician who, after a "cosmic fluke", give a talk justafter a Nobel laureate that discovered the cosmic microwave backgroundradiation.Such "cosmic flukes" sometimes happen. If you were not at the dinner of the SEA meeting and do not believe us, visithttp://www.myspace.com/antonioariasmultiverso or open the proceedings DVD andlisten "El ordenador simula el nacimiento de las estrella...".

  7. Laboratory characterization of rock joints

    Energy Technology Data Exchange (ETDEWEB)

    Hsiung, S.M.; Kana, D.D.; Ahola, M.P.; Chowdhury, A.H.; Ghosh, A. [Southwest Research Inst., San Antonio, TX (United States). Center for Nuclear Waste Regulatory Analyses

    1994-05-01

    A laboratory characterization of the Apache Leap tuff joints under cyclic pseudostatic and dynamic loads has been undertaken to obtain a better understanding of dynamic joint shear behavior and to generate a complete data set that can be used for validation of existing rock-joint models. Study has indicated that available methods for determining joint roughness coefficient (JRC) significantly underestimate the roughness coefficient of the Apache Leap tuff joints, that will lead to an underestimation of the joint shear strength. The results of the direct shear tests have indicated that both under cyclic pseudostatic and dynamic loadings the joint resistance upon reverse shearing is smaller than that of forward shearing and the joint dilation resulting from forward shearing recovers during reverse shearing. Within the range of variation of shearing velocity used in these tests, the shearing velocity effect on rock-joint behavior seems to be minor, and no noticeable effect on the peak joint shear strength and the joint shear strength for the reverse shearing is observed.

  8. Rock breakage mechanisms with a PDC cutter

    Energy Technology Data Exchange (ETDEWEB)

    1985-01-01

    Some aspects of chip generation by a polycrystalline diamond compact (PDC) cutter moving through a rock can be understood by examining the shapes of the chips and the fracture patterns in the remaining rock. Data from laboratory experiments have led to general conclusions about the uniformity of chip generation mechanisms in different kinds of rock and about crack nucleation position relative to the cutter tip. 20 refs., 12 figs., 2 tabs.

  9. Combination of minimum enclosing balls classifier with SVM in coal-rock recognition.

    Directory of Open Access Journals (Sweden)

    QingJun Song

    Full Text Available Top-coal caving technology is a productive and efficient method in modern mechanized coal mining, the study of coal-rock recognition is key to realizing automation in comprehensive mechanized coal mining. In this paper we propose a new discriminant analysis framework for coal-rock recognition. In the framework, a data acquisition model with vibration and acoustic signals is designed and the caving dataset with 10 feature variables and three classes is got. And the perfect combination of feature variables can be automatically decided by using the multi-class F-score (MF-Score feature selection. In terms of nonlinear mapping in real-world optimization problem, an effective minimum enclosing ball (MEB algorithm plus Support vector machine (SVM is proposed for rapid detection of coal-rock in the caving process. In particular, we illustrate how to construct MEB-SVM classifier in coal-rock recognition which exhibit inherently complex distribution data. The proposed method is examined on UCI data sets and the caving dataset, and compared with some new excellent SVM classifiers. We conduct experiments with accuracy and Friedman test for comparison of more classifiers over multiple on the UCI data sets. Experimental results demonstrate that the proposed algorithm has good robustness and generalization ability. The results of experiments on the caving dataset show the better performance which leads to a promising feature selection and multi-class recognition in coal-rock recognition.

  10. Combination of minimum enclosing balls classifier with SVM in coal-rock recognition.

    Science.gov (United States)

    Song, QingJun; Jiang, HaiYan; Song, Qinghui; Zhao, XieGuang; Wu, Xiaoxuan

    2017-01-01

    Top-coal caving technology is a productive and efficient method in modern mechanized coal mining, the study of coal-rock recognition is key to realizing automation in comprehensive mechanized coal mining. In this paper we propose a new discriminant analysis framework for coal-rock recognition. In the framework, a data acquisition model with vibration and acoustic signals is designed and the caving dataset with 10 feature variables and three classes is got. And the perfect combination of feature variables can be automatically decided by using the multi-class F-score (MF-Score) feature selection. In terms of nonlinear mapping in real-world optimization problem, an effective minimum enclosing ball (MEB) algorithm plus Support vector machine (SVM) is proposed for rapid detection of coal-rock in the caving process. In particular, we illustrate how to construct MEB-SVM classifier in coal-rock recognition which exhibit inherently complex distribution data. The proposed method is examined on UCI data sets and the caving dataset, and compared with some new excellent SVM classifiers. We conduct experiments with accuracy and Friedman test for comparison of more classifiers over multiple on the UCI data sets. Experimental results demonstrate that the proposed algorithm has good robustness and generalization ability. The results of experiments on the caving dataset show the better performance which leads to a promising feature selection and multi-class recognition in coal-rock recognition.

  11. Regulation of ROCK Activity in Cancer

    Science.gov (United States)

    Morgan-Fisher, Marie; Wewer, Ulla M.

    2013-01-01

    Cancer-associated changes in cellular behavior, such as modified cell-cell contact, increased migratory potential, and generation of cellular force, all require alteration of the cytoskeleton. Two homologous mammalian serine/threonine kinases, Rho-associated protein kinases (ROCK I and II), are key regulators of the actin cytoskeleton acting downstream of the small GTPase Rho. ROCK is associated with cancer progression, and ROCK protein expression is elevated in several types of cancer. ROCKs exist in a closed, inactive conformation under quiescent conditions, which is changed to an open, active conformation by the direct binding of guanosine triphosphate (GTP)–loaded Rho. In recent years, a number of ROCK isoform-specific binding partners have been found to modulate the kinase activity through direct interactions with the catalytic domain or via altered cellular localization of the kinases. Thus, these findings demonstrate additional modes to regulate ROCK activity. This review describes the molecular mechanisms of ROCK activity regulation in cancer, with emphasis on ROCK isoform-specific regulation and interaction partners, and discusses the potential of ROCKs as therapeutic targets in cancer. PMID:23204112

  12. Estética del rock

    OpenAIRE

    Rey, Sebastián

    2014-01-01

    El objetivo del presente artículo es el de analizar la estética del Rock en términos de la experiencia que ofrece este género musical. En primer lugar se construirá una relación entre el Nacimiento de la tragedia de Nietzsche y el surgimiento del Rock, bajo la premisa de que el origen del Rock es eminentemente dionisíaco; luego se mostrará una forma de la experiencia en la vida cotidiana de quien escucha Rock, en donde se da cuenta de la necesidad de expresar los sentimientos de placer y disp...

  13. Prediction of rock brittleness using nondestructive methods for hard rock tunneling

    Directory of Open Access Journals (Sweden)

    Rennie B. Kaunda

    2016-08-01

    Full Text Available The material and elastic properties of rocks are utilized for predicting and evaluating hard rock brittleness using artificial neural networks (ANN. Herein hard rock brittleness is defined using Yagiz' method. A predictive model is developed using a comprehensive database compiled from 30 years' worth of rock tests at the Earth Mechanics Institute (EMI, Colorado School of Mines. The model is sensitive to density, elastic properties, and P- and S-wave velocities. The results show that the model is a better predictor of rock brittleness than conventional destructive strength-test based models and multiple regression techniques. While the findings have direct implications on intact rock, the methodology can be extrapolated to rock mass problems in both tunneling and underground mining where rock brittleness is an important control.

  14. Effects of Oxidation and fractal surface roughness on the wettability and critical heat flux of glass-peened zirconium alloy tubes

    Energy Technology Data Exchange (ETDEWEB)

    Fong, R.W.L.; Nitheanandan, T.; Bullock, C.D.; Slater, L.F.; McRae, G.A

    2003-05-01

    Glass-bead peening the outside surfaces of zirconium alloy tubes has been shown to increase the Critical Heat Flux (CHF) in pool boiling of water. The CHF is found to correlate with the fractal roughness of the metal tube surfaces. In this study on the effect of oxidation on glass-peened surfaces, test measurements for CHF, surface wettability and roughness have been evaluated using various glass-peened and oxidized zirconium alloy tubes. The results show that oxidation changes the solid-liquid contact angle (i.e., decreases wettability of the metal-oxide surface), but does not change the fractal surface roughness, appreciably. Thus, oxidation of the glass-peened surfaces of zirconium alloy tubes is not expected to degrade the CHF enhancement obtained by glass-bead peening. (author)

  15. Water and oil wettability of hybrid organic-inorganic titanate-silicate thin films deposited via a sol-gel route

    Science.gov (United States)

    Houmard, M.; Vasconcelos, D. C. L.; Vasconcelos, W. L.; Berthomé, G.; Joud, J. C.; Langlet, M.

    2009-09-01

    Hybrid organic-inorganic titanate-silicate thin films were deposited on silicium wafer via a sol-gel route. Hybrid sols were formulated by mixing an inorganic titanium alkoxide solution with solutions of hybrid organic-inorganic silicon alkoxides partially substituted with non-hydrolysable alkyl chains. Three organo-silicate precursors were used to introduce methyl, octyl, or hexadecyl chains in the oxide network. Physico-chemical and morphological properties of derived hybrid films have been studied by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, ellipsometry, and atomic force microscopy. Contact angle measurements have also been performed to assess the water and mineral oil wettability of hybrid films. Wettability properties of these films are discussed with respect to physico-chemical and morphological features. It is shown that increasing the fraction and length of alkyl chains in the oxide network conjointly increases water and oil contact angles measured on such hybrid films.

  16. Wettability, soil organic matter and structure-properties of typical chernozems under the forest and under the arable land

    Science.gov (United States)

    Bykova, Galina; Umarova, Aminat; Tyugai, Zemfira; Milanovskiy, Evgeny; Shein, Evgeny

    2017-04-01

    Intensive tillage affects the properties of soil: decrease in content of soil organic matter and in hydrophobicity of the soil's solid phase, the reduction of amount of water stable aggregates - all this leads to deterioration of the structure of the soil and affects the process of movement of moisture in the soil profile. One of the hypotheses of soil's structure formation ascribes the formation of water stable aggregates with the presence of hydrophobic organic substances on the surface of the soil's solid phase. The aim of this work is to study the effect of tillage on properties of typical chernozems (pachic Voronic Chernozems, Haplic Chernozems) (Russia, Kursk region), located under the forest and under the arable land. The determination of soil-water contact angle was performed by a Drop Shape Analyzer DSA100 (Krüss GmbH, Germany) by the static sessile drop method. For all samples the content of total and organic carbon by dry combustion in oxygen flow and the particle size distribution by the laser diffraction method on the device Analysette 22 comfort, FRITCH, Germany were determined. The estimation of aggregate composition was performed by dry sieving (AS 200, Retsch, Germany), the content of water stable aggregates was estimated by the Savvinov method. There was a positive correlation between the content of organic matter and soil's wettability in studied soils, a growth of contact angle with the increasing the content of organic matter. Under the forest the content of soil organic matter was changed from 6,41% on the surface up to 1,9% at the depth of 100 cm. In the Chernozem under the arable land the organic carbon content in arable horizon is almost two times less. The maximum of hydrophobicity (78.1o) was observed at the depth of 5 cm under the forest. In the profile under the arable land the contact angle value at the same depth was 50o. The results of the structure analysis has shown a decrease in the content of agronomically valuable and water

  17. An investigation of rock fall and pore water pressure using LIDAR in Highway 63 rock cuts.

    Science.gov (United States)

    2014-07-01

    The purpose of this research work is compare LIDAR scanning measurements of rock fall with the natural changes in groundwater level to determining the effect of water pressures (levels) on rock fall. To collect the information of rock cut volume chan...

  18. Computational Models of Rock Failure

    Science.gov (United States)

    May, Dave A.; Spiegelman, Marc

    2017-04-01

    Practitioners in computational geodynamics, as per many other branches of applied science, typically do not analyse the underlying PDE's being solved in order to establish the existence or uniqueness of solutions. Rather, such proofs are left to the mathematicians, and all too frequently these results lag far behind (in time) the applied research being conducted, are often unintelligible to the non-specialist, are buried in journals applied scientists simply do not read, or simply have not been proven. As practitioners, we are by definition pragmatic. Thus, rather than first analysing our PDE's, we first attempt to find approximate solutions by throwing all our computational methods and machinery at the given problem and hoping for the best. Typically this approach leads to a satisfactory outcome. Usually it is only if the numerical solutions "look odd" that we start delving deeper into the math. In this presentation I summarise our findings in relation to using pressure dependent (Drucker-Prager type) flow laws in a simplified model of continental extension in which the material is assumed to be an incompressible, highly viscous fluid. Such assumptions represent the current mainstream adopted in computational studies of mantle and lithosphere deformation within our community. In short, we conclude that for the parameter range of cohesion and friction angle relevant to studying rocks, the incompressibility constraint combined with a Drucker-Prager flow law can result in problems which have no solution. This is proven by a 1D analytic model and convincingly demonstrated by 2D numerical simulations. To date, we do not have a robust "fix" for this fundamental problem. The intent of this submission is to highlight the importance of simple analytic models, highlight some of the dangers / risks of interpreting numerical solutions without understanding the properties of the PDE we solved, and lastly to stimulate discussions to develop an improved computational model of

  19. Efficacies of wettable pellet and fresh culture of Trichoderma asperellum biocontrol products in growth promoting and reducing dirty panicles of rice

    Directory of Open Access Journals (Sweden)

    Phraomas Charoenrak

    2016-07-01

    Full Text Available Wettable pellets and fresh culture (fungus-colonized rice seeds bioproducts of Trichoderma asperellum isolates 01-52 and CB-Pin-01, respectively, were evaluated for their efficacy in reducing dirty panicle or seed discoloration, and to increase the growth and yield of rice var. Chai Nat 1. Rice seeds were soaked (Sk in a spore suspension of wettable pellets (20 g/20 L or a fresh culture of bioproducts (100 g/20 L of the fungus for 24 h. Soaked seeds were incubated for another 24 h before sowing. The 21-day-old seedlings were transplanted into small plots (1 m2 × 3 m2. Rice plants were sprayed (Sp three times during the growing period with a spore suspension from the two bioproducts. The results indicated that both wettable pellet 01-52 (Sk + Sp and fresh culture CB-Pin-01 (Sk + Sp formulations significantly increased the plant height, number of tillers per hill, 1000-seed weight and total yield of rice compared to the untreated control. The incidence of dirty whole rice panicles, dirty panicle infected seed and empty seed were significantly reduced, while healthy seed were increased compared to the untreated control. Rice root colonization by T. asperellum isolates 01-52 and CB-Pin-01 were detected from the seedling through to the harvesting stage. The seedling vigor index and seedling health index of seedlings grown from 5 month-stored healthy and dirty panicle infected seeds treated by both wettable pellet 01-52 (Sk + Sp and fresh culture CB-Pin-01 (Sk + Sp bioproducts were significantly higher than the untreated control. All Trichoderma treatments increased whole kernels plus head rice and reduced broken rice in milled brown rice.

  20. Improved Surface Wettability of Water by Applying SiC/Ti6Al4V Coatings on Carbon/Carbon Composites

    Directory of Open Access Journals (Sweden)

    Lei-Lei Zhang

    2013-01-01

    Full Text Available SiC/Ti6Al4V coatings were applied on carbon/carbon composites to improve the surface wettability of water. SiC interlayers were preprepared by pack cementation to bond both the carbon/carbon composites and the Ti6Al4V, and then the Ti6Al4V coatings were applied by magnetron sputtering technique. The morphology and crystalline of the SiC/Ti6Al4V coatings were analyzed by scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction. The surface wettability of the coatings was tested by video-based contact angle measuring device. The results showed that SiC can serve as an interlayer between the carbon/carbon composites and Ti6Al4V. The SiC/Ti6Al4V coatings covered the carbon/carbon composites uniformly with spherical morphology. The coatings improved the surface wettability of carbon/carbon composites with the contact angle of water decreasing from 85.7 ± 4.1° to 26.5 ± 0.1°.

  1. Toe rock stability for rubble mound breakwaters

    NARCIS (Netherlands)

    Baart, S.; Ebbens, R.; Nammuni-Krohn, J.; Verhagen, H.J.

    2010-01-01

    Present design tools, as found in the Rock Manual or Coastal Engineering Manual, for the determination of toe rock size for rubble mound breakwaters are based on test data with a large spread: data is relatively dispersed around the centre and descriptive equations have limited applicability ranges.

  2. Rock Cycle. K-6 Science Curriculum.

    Science.gov (United States)

    Blueford, J. R.; And Others

    Rock Cycle is one of the units of a K-6 unified science curriculum program. The unit consists of four organizing sub-themes: (1) chemistry (introducing the topics of matter, elements, compounds, and chemical bonding); (2) characteristics (presenting hands-on activities with rocks and minerals); (3) minerals (emphasizing the aesthetic and economic…

  3. Rock Music and Korean Adolescent's Antisocial Behavior.

    Science.gov (United States)

    Kim, Inkyung; Kwak, Keumjoo; Chang, Geunyoung; Yang, Jinyoung

    The relationship between rock music preference and antisocial behavior among Korean adolescents was examined. The Korean versions of the Sensation Seeking Scale and the Antisocial Behavior Checklist were used to measure sensation seeking motivation and delinquency. Adolescents (N=1,079) were categorized as "rock/metal,""dance,"…

  4. Hot-dry-rock feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    1981-08-01

    The hot-dry-rock project tasks are covered as follows: hot-dry-rock reservoir; generation facilities; water resources; transmission requirements; environmental issues; government and community institutional factors; leasing, ownership and management of facilities; regulations, permits, and laws; and financial considerations. (MHR)

  5. Optically stimulated luminescence dating of rock surfaces

    DEFF Research Database (Denmark)

    Sohbati, Reza

    There are many examples of rock surfaces, rock art and stone structures whose ages are of great importance to the understanding of various phenomena in geology, climatology and archaeology. Optically stimulated luminescence (OSL) dating is a well-established chronological tool that has successfully...... determined the depositional age of a wide variety of fine-grained sediments, from several years to several hundred thousands of years. However, there is no routine OSL dating method applicable to larger clasts such as cobbles, boulders and other rock surfaces. Here the application of quartz OSL to the dating...... of rock surfaces is successfully tested by application to two different quartz-rich rock types (sandstone and quartzite). Together with the measurement of infrared stimulated luminescence (IRSL) signals as a function of depth into the surface of different granites it is clear that both OSL and IRSL can...

  6. Thermally induced rock breakdown on asteroid Itokawa

    Science.gov (United States)

    Kitazato, Kohei; Hirata, Naru; Demura, Hirohide; Inasawa, Tomoki; Abe, Masanao; Yamamoto, Yukio; Miura, Akira; Kawaguchi, Jun'ichiro

    2017-10-01

    On airless bodies of the inner solar system, changes in surface temperature due to insolation yield thermal cracking of rocks. This has been considered as a leading cause of rock breakdown, crater degradation and regolith production. However, it is poorly understood what thermal conditions are actually required to cause damage in rocks. Here we present a new evidence of thermally induced rock breakdown found on asteroid Itokawa. We analyzed the visible and near-infrared spectra of Shirakami and Muses-C regio, both of which are located within the concave part of Itokawa, and found that less space weathered debris generated from Shirakami are deposited on Muses-C regio. In addition, we performed thermophysical analysis to calculate the thermal conditions of Itokawa surface, which indicates that the rock breakdown on Shirakami would be caused by rapid temperature changes related to shadowing.

  7. Improvement of surface wettability and interfacial adhesion of poly-(p-phenylene terephthalamide) by incorporation of the polyamide benzimidazole segment

    Science.gov (United States)

    Cai, Ren-Qin; Peng, Tao; Wang, Feng-De; Ye, Guang-Dou; Xu, Jian-Jun

    2011-09-01

    In order to investigate the effect of the polyamide benzimidazole group on the surface wettability and interfacial adhesion of fiber/matrix composites, surface features of two kinds of aramid fibers, poly (p-phenylene terephthalamide) fiber (Kevlar-49) and poly-(polyamide benzimidazole-co-p-phenylene terephthalamide) (DAFIII), have been analyzed by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and contact angle analysis (CAA) system, respectively. The results show that with the incorporation of the polyamide benzimidazole segment, more polar functional groups exist on DAFIII surface. The contact angles of water and diiodomethane on DAFIII surface get smaller. The surface free energy of DAFIII increases to 36.5 mJ/m 2, which is 2.3% higher than that of Kevlar-49. In addition, DAFIII has a larger rough surface compared with that of Kevlar-49 due to different spinning processes. The interfacial shear strength (IFSS) of DAFIII/matrix composite is 25.7% higher than that of Kevlar-49/matrix composite, in agreement with the observed results from surface feature tests. SEM micrographs of failed micro-droplet specimens reveal a strong correlation between the fracture features and the observed test data.

  8. Improvement of surface wettability and interfacial adhesion of poly-(p-phenylene terephthalamide) by incorporation of the polyamide benzimidazole segment

    Energy Technology Data Exchange (ETDEWEB)

    Cai Renqin [State key Laboratory of Polymer Materials Engineering, College of Polymer Science and Engineering, Sichuan University, Chengdu 610065 (China); Peng Tao [State key Laboratory of Polymer Materials Engineering, College of Polymer Science and Engineering, Sichuan University, Chengdu 610065 (China); China Blue Star Chengrand Chemical Co. Ltd., Chengdu, 610041 (China); Wang Fengde [China Blue Star Chengrand Chemical Co. Ltd., Chengdu, 610041 (China); Ye Guangdou [State key Laboratory of Polymer Materials Engineering, College of Polymer Science and Engineering, Sichuan University, Chengdu 610065 (China); Xu Jianjun, E-mail: xujj@scu.edu.cn [State key Laboratory of Polymer Materials Engineering, College of Polymer Science and Engineering, Sichuan University, Chengdu 610065 (China)

    2011-09-01

    In order to investigate the effect of the polyamide benzimidazole group on the surface wettability and interfacial adhesion of fiber/matrix composites, surface features of two kinds of aramid fibers, poly (p-phenylene terephthalamide) fiber (Kevlar-49) and poly-(polyamide benzimidazole-co-p-phenylene terephthalamide) (DAFIII), have been analyzed by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and contact angle analysis (CAA) system, respectively. The results show that with the incorporation of the polyamide benzimidazole segment, more polar functional groups exist on DAFIII surface. The contact angles of water and diiodomethane on DAFIII surface get smaller. The surface free energy of DAFIII increases to 36.5 mJ/m{sup 2}, which is 2.3% higher than that of Kevlar-49. In addition, DAFIII has a larger rough surface compared with that of Kevlar-49 due to different spinning processes. The interfacial shear strength (IFSS) of DAFIII/matrix composite is 25.7% higher than that of Kevlar-49/matrix composite, in agreement with the observed results from surface feature tests. SEM micrographs of failed micro-droplet specimens reveal a strong correlation between the fracture features and the observed test data.

  9. Low temperature growth of ZnO nanostructures on flexible polystyrene substrates for optical, photoluminescence and wettability applications

    Science.gov (United States)

    Durga Prasad, Muvva; Pasha Shaik, Ummar; Madhurima, V.; Ghanashyam Krishna, M.

    2016-08-01

    The growth of ZnO nanostructures on flexible polystyrene substrates by a simple vacuum thermal evaporation process is reported. The ZnO films are deposited on polystyrene surfaces of 6 μm thickness which are initially anchored on glass substrates. The as-deposited films are annealed at temperatures up to 180 °C for 6-24 h after which the polystyrene is lifted off from the glass substrates to yield nanostructured films on a flexible substrate. At 180 °C there is transformation of the partially oxidized as-deposited films into nearly stoichiometric ZnO. This is accompanied by the formation of nanostructures such as nanorods, nanotubes and nanodoughnuts. The films, which were 50-200 nm in thickness, are polycrystalline in nature and also exhibit Zn/ZnO core-shell structures under favorable conditions. The nanostructures exhibit transmission greater than 80% in the visible and near infrared regions and band gaps of the order of 4 eV. The films exhibit strong blue photoluminescence and the peak position as well as intensity of emission can be tuned by varying thickness and annealing conditions. To demonstrate the flexibility, the ZnO coated polystyrene substrates were wrapped around a LED to show UV blocking property. Wettability studies indicate that films are hydrophobic with water contact angles between 92°-95°.

  10. Effect of dielectric barrier discharge treatment on surface nanostructure and wettability of polylactic acid (PLA) nonwoven fabrics

    Science.gov (United States)

    Ren, Yu; Xu, Lin; Wang, Chunxia; Wang, Xiaona; Ding, Zhirong; Chen, Yuyue

    2017-12-01

    Polylactic acid (PLA) nonwoven fabrics are treated with atmospheric dielectric barrier discharge (DBD) plasma to improve surface wettability. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) show that micro- to nano-scale textures appear on the treated PLA surfaces dependent on the treatment time. X-ray photoelectron spectroscopy (XPS) analysis reveals that the DBD plasma treatments result in decreased carbon contents and increased oxygen contents as well as slightly increased nitrogen contents. The water contact angle decreases sharply with the increase of the DBD plasma treatment time. The super hydrophilic PLA surfaces (the water contact angle reached 0°) are obtained when the treatment time is longer than 90 s. Ninety days after the DBD plasma treatment, the XPS analysis shows that Csbnd O/Csbnd N and Cdbnd O/Osbnd Cdbnd O percentages decline for all treatment groups. However, the water contact angle is kept constant at 0° for the groups treated above 90 s, which could be due to the oxidized nano-structured layer on the DBD plasma treated PLA surfaces.

  11. Electrokinetics over charge-modulated surfaces in the presence of patterned wettability: Role of the anisotropic streaming potential

    Science.gov (United States)

    Ghosh, Uddipta; Chakraborty, Suman

    2013-09-01

    In the present study, we focus on evaluating the induced streaming electric field along the orthogonal directions in a narrow fluidic confinement in the presence of patterned surface wettability and modulated surface charges. We attempt to assess the implications of such modulations on the related important quantities and pinpoint the regimes of improved induced streaming potential field and the resulting anisotropy in the induced potential. Our results reveal that for certain combinations of the parameters characterizing the modulated slip, a significant amount of augmentation in the streaming electric field might be obtained, whereas in other cases the effects may lead to adverse consequences. We further demonstrate that the presence of anisotropic modulations on the channel walls give rise to considerable off-diagonal effects, which makes the streaming potential “disoriented” with the applied pressure gradient, when the same is not applied along one of the orthogonal directions. Our analysis also shows that one can remove such “mis-orientations” by finely tuning several relevant flow and geometric parameters, which may bear immense scientific and technological consequences towards an improved design of miniaturized energy conversion devices.

  12. Multiphysics Simulation and Experimental Investigation of Aluminum Wettability on a Titanium Substrate for Laser Welding-Brazing Process

    Directory of Open Access Journals (Sweden)

    Morgan Dal

    2017-06-01

    Full Text Available The control of metal wettability is a key-factor in the field of brazing or welding-brazing. The present paper deals with the numerical simulation of the whole phenomena occurring during the assembly of dissimilar alloys. The study is realized in the frame of potential applications for the aircraft industry, considering the case of the welding-brazing of aluminum Al5754 and quasi-pure titanium Ti40. The assembly configuration, presented here, is a simplification of the real experiment. We have reduced the three-dimensional overlap configuration to a bi-dimensional case. In the present case, an aluminum cylinder is fused onto a titanium substrate. The main physical phenomena which are considered here are: the heat transfers, the fluid flows with free boundaries and the mass transfer in terms of chemical species diffusion. The numerical problem is implemented with the commercial software Comsol Multiphysics™, by coupling heat equation, Navier-Stokes and continuity equations and the free boundary motion. The latter is treated with the Arbitrary Lagrangian Eulerian method, with a particular focus on the contact angle implementation. The comparison between numerical and experimental results shows a very satisfactory agreement in terms of droplet shape, thermal field and intermetallic layer thickness. The model validates our numerical approach.

  13. The wettability between etching solutions and the surface of multicrystalline silicon wafer during metal-assisted chemical etching process

    Science.gov (United States)

    Niu, Y. C.; Liu, Z.; Liu, X. J.; Gao, Y.; Lin, W. L.; Liu, H. T.; Jiang, Y. S.; Ren, X. K.

    2017-01-01

    In order to investigate the wettability of multicrystalline silicon (mc-Si) with the etching solutions during metal-assisted chemical etching process, different surface structures were fabricated on the p-type multi-wire slurry sawn mc-Si wafers, such as as-cut wafers, polished wafers, and wafers etched in different solutions. The contact angles of different etching solutions on the surfaces of the wafers were measured. It was noted that all contact angles of etching solutions were smaller than the corresponding ones of deionized water, but the contact angles of different etching solutions were quite different. Among the contact angles of the etching solutions of AgNO3-HF, H2O2-HF, TMAH and HNO3-HF, the contact angle of TMAH solution was much larger than the others and that of HNO3-HF solution was much smaller. It is suggested that the larger contact angle may lead to an unevenly etching of silicon wafer due to the long retention of big bubbles on the wafers in the etching reaction, which should be paid attention to and overcome.

  14. Characterization of highly hydrophobic textiles by means of X-ray microtomography, wettability analysis and drop impact

    Science.gov (United States)

    Santini, M.; Guilizzoni, M.; Fest-Santini, S.; Lorenzi, M.

    2017-11-01

    Highly hydrophobic surfaces have been intensively investigated in the last years because their properties may lead to very promising technological spillovers encompassing both everyday use and high-tech fields. Focusing on textiles, hydrophobic fabrics are of major interest for applications ranging from clothes to architecture to environment protection and energy conversion. Gas diffusion media – made by a gas diffusion layer (GDL) and a microporous layer (MPL) – for fuel cells are a good benchmark to develop techniques aimed at characterizing the wetting performances of engineered textiles. An experimental investigation was carried out about carbon-based, PTFE-treated GDLs with and without MPLs. Two samples (woven and woven-non-woven) were analysed before and after coating with a MPL. Their three-dimensional structure was reconstructed and analysed by computer-aided X-ray microtomography (µCT). Static and dynamic wettability analyses were then carried out using a modified axisymmetric drop shape analysis technique. All the surfaces exhibited very high hydrophobicity, three of them near to a super-hydrophobic behavior. Water drop impacts were performed, evidencing different bouncing, sticking and fragmentation outcomes for which critical values of the Weber number were identified. Finally, a µCT scan of a drop on a GDL was performed, confirming the Cassie-Baxter wetting state on such surface.

  15. Microbial biofilm growth versus tissue integration on biomaterials with different wettabilities and a polymer-brush coating.

    Science.gov (United States)

    Subbiahdoss, Guruprakash; Grijpma, Dirk W; van der Mei, Henny C; Busscher, Henk J; Kuijer, Roel

    2010-08-01

    Biomaterials-associated infections (BAI) constitute a major clinical problem and often necessitate implant replacement. In this study, the race for the surface between Staphylococcus epidermidis ATCC 35983 and U2OS osteosarcoma cells is studied on biomaterials with different wettabilities and on a polymer-brush coating. S. epidermidis was deposited on the different surfaces in a parallel plate flow chamber and then U2OS cells were seeded. Subsequently, staphylococci and U2OS cells were allowed to grow simultaneously on the surfaces for 48 h under low flow conditions. The presence of staphylococci reduced cell growth on all surfaces, but adhering cells spread equally well in the absence and presence of staphylococci. A hydrophilic polymer-brush coating discouraged bacterial and cellular adhesion and growth. Thus, whereas the biomaterials evaluated support both biofilm formation and tissue integration, polymer-brush coatings support neither. Therewith, the outcome of the race for the surface on these surfaces remains uncertain, emphasizing the need for biofunctionalized surfaces that discourage biofilm formation and support tissue growth at the same time. (c) 2010 Wiley Periodicals, Inc.

  16. Tunable surface wettability and water adhesion of Sb{sub 2}S{sub 3} micro-/nanorod films

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Xin; Zhao, Huiping [Key Laboratory for Green Chemical Process of Ministry of Education and Hubei Novel Reactor and Green Chemical Technology Key Laboratory, Wuhan Institute of Technology, Xiongchu Street, Wuhan 430073 (China); Yang, Hao, E-mail: hyangwit@hotmail.com [Key Laboratory for Green Chemical Process of Ministry of Education and Hubei Novel Reactor and Green Chemical Technology Key Laboratory, Wuhan Institute of Technology, Xiongchu Street, Wuhan 430073 (China); Liu, Yunling [State Key laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012 (China); Yan, Guoping [Key Laboratory for Green Chemical Process of Ministry of Education and Hubei Novel Reactor and Green Chemical Technology Key Laboratory, Wuhan Institute of Technology, Xiongchu Street, Wuhan 430073 (China); Chen, Rong, E-mail: rchenhku@hotmail.com [Key Laboratory for Green Chemical Process of Ministry of Education and Hubei Novel Reactor and Green Chemical Technology Key Laboratory, Wuhan Institute of Technology, Xiongchu Street, Wuhan 430073 (China)

    2014-01-15

    Antimony sulfide (Sb{sub 2}S{sub 3}) films were successfully prepared by spin coating Sb{sub 2}S{sub 3} micro-/nanorods with different sizes on glass slides, which was synthesized via a facile and rapid microwave irradiation method. The prepared Sb{sub 2}S{sub 3} micro-/nanorods and films were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and water contact angle (CA). The as-prepared Sb{sub 2}S{sub 3} films exhibited different surface wettabilities ranging from superhydrophilicity to superhydrophobicity, which was strongly dependent on the diameter of Sb{sub 2}S{sub 3} micro-/nanorod. Sb{sub 2}S{sub 3} film made by nanorods possessed superhydrophobic surface and high water adhesive property. After surface modification with stearic acid, the superhydrophobic surface exhibited an excellent self-cleaning property owing to its low adhesive force. The clarification of three possible states including Wenzel's state, “Gecko” state and Cassie's state for Sb{sub 2}S{sub 3} film surfaces was also proposed to provide a better understanding of interesting surface phenomena on Sb{sub 2}S{sub 3} films.

  17. Compositional Modeling for Optimum Design of Water-Alternating CO2-LPG EOR under Complicated Wettability Conditions

    Directory of Open Access Journals (Sweden)

    Jinhyung Cho

    2015-01-01

    Full Text Available The addition of LPG to the CO2 stream leads to minimum miscible pressure (MMP reduction that causes more oil swelling and interfacial tension reduction compared to CO2 EOR, resulting in improved oil recovery. Numerical study based on compositional simulation has been performed to examine the injectivity efficiency and transport behavior of water-alternating CO2-LPG EOR. Based on oil, CO2, and LPG prices, optimum LPG concentration and composition were designed for different wettability conditions. Results from this study indicate how injected LPG mole fraction and butane content in LPG affect lowering of interfacial tension. Interfacial tension reduction by supplement of LPG components leads to miscible condition causing more enhanced oil recovery. The maximum enhancement of oil recovery for oil-wet reservoir is 50% which is greater than 22% for water-wet reservoir. According to the result of net present value (NPV analysis at designated oil, CO2, propane, and butane prices, the optimal injected LPG mole fraction and composition exist for maximum NPV. At the case of maximum NPV for oil-wet reservoir, the LPG fraction is about 25% in which compositions of propane and butane are 37% and 63%, respectively. For water-wet reservoir, the LPG fraction is 20% and compositions of propane and butane are 0% and 100%.

  18. Continuous, high-flux and efficient oil/water separation assisted by an integrated system with opposite wettability

    Science.gov (United States)

    Li, Jian; Long, Yifei; Xu, Changcheng; Tian, Haifeng; Wu, Yanxia; Zha, Fei

    2018-03-01

    To resolve the drawbacks that single-mesh involved for oil/water separation, such as batch processing mode, only one phase was purified and the quick decrease in flux et al., herein, a two-way separation T-tube device was designed by integrating a pair of meshes with opposite wettability, i.e., underwater superoleophobic and superhydrophobic/superoleophilic properties. Such integrated system can continuously separate both oil and water phase from the oil/water mixtures simultaneously through one-step procedure with high flux (above 3.675 L m-2 s-1) and high separation efficiency larger than 99.8% regardless of the heavy oil or light oil involved in the mixture. Moreover, the as-prepared two meshes still maintained high separation efficiency larger than above 98.9% even after 50 cycle-usages. It worthy mentioned that this two-way separation mode essentially solves the oil liquid accumulation problem that is the single separation membrane needs to tolerate a large hydrostatic pressure caused by the accumulated liquid. We deeply believe this two-way separation system would provide a new strategy for realizing practical applications in oil spill clean-up via a continuous mode.

  19. Low-Pressure H2, NH3 Microwave Plasma Treatment of Polytetrafluoroethylene (PTFE Powders: Chemical, Thermal and Wettability Analysis

    Directory of Open Access Journals (Sweden)

    Harald Hunke

    2015-04-01

    Full Text Available Functionalization of Polytetrafluoroethylene (PTFE powders of ~6 μm particle size is carried out using low-pressure 2.45 GHz H2, NH3 microwave plasmas for various durations (2.5, 10 h to chemically modify their surface and alter their surface energy. The X-ray Photoelectron Spectroscopy (XPS analyses reveal that plasma treatment leads to significant defluorination (F/C atomic ratio of 1.13 and 1.30 for 10 h NH3 and H2 plasma treatments, respectively vs. 1.86 for pristine PTFE, along with the incorporation of functional polar moieties on the surface, resulting in enhanced wettability. Analysis of temperature dependent XPS revealed a loss of surface moieties above 200 °C, however, the functional groups are not completely removable even at higher temperatures (>300 °C, thus enabling the use of plasma treated PTFE powders as potential tribological fillers in high temperature engineering polymers. Ageing studies carried over a period of 12 months revealed that while the surface changes degenerate over time, again, they are not completely reversible. These functionalised PTFE powders can be further used for applications into smart, high performance materials such as tribological fillers for engineering polymers and bio-medical, bio-material applications.

  20. The physiology of rock climbing.

    Science.gov (United States)

    Giles, Luisa V; Rhodes, Edward C; Taunton, Jack E

    2006-01-01

    In general, elite climbers have been characterised as small in stature, with low percentage body fat and body mass. Currently, there are mixed conclusions surrounding body mass and composition, potentially because of variable subject ability, method of assessment and calculation. Muscular strength and endurance in rock climbers have been primarily measured on the forearm, hand and fingers via dynamometry. When absolute hand strength was assessed, there was little difference between climbers and the general population. When expressed in relation to body mass, elite-level climbers scored significantly higher, highlighting the potential importance of low body mass. Rock climbing is characterised by repeated bouts of isometric contractions. Hand grip endurance has been measured by both repeated isometric contractions and sustained contractions, at a percentage of maximum voluntary contraction. Exercise times to fatigue during repeated isometric contractions have been found to be significantly better in climbers when compared with sedentary individuals. However, during sustained contractions until exhaustion, climbers did not differ from the normal population, emphasising the importance of the ability to perform repeated isometric forearm contractions without fatigue becoming detrimental to performance. A decrease in handgrip strength and endurance has been related to an increase in blood lactate, with lactate levels increasing with the angle of climbing. Active recovery has been shown to provide a better rate of recovery and allows the body to return to its pre-exercised state quicker. It could be suggested that an increased ability to tolerate and remove lactic acid during climbing may be beneficial. Because of increased demand placed upon the upper body during climbing of increased difficulty, possessing greater strength and endurance in the arms and shoulders could be advantageous. Flexibility has not been identified as a necessary determinant of climbing success

  1. Impact of Stress on Anomalous Transport in Fractured Rock

    Science.gov (United States)

    Kang, P. K.; Lei, Q.; Lee, S.; Dentz, M.; Juanes, R.

    2016-12-01

    Fluid flow and transport in fractured rock controls many natural and engineered processes in the subsurface. However, characterizing flow and transport through fractured media is challenging due to the large heterogeneity of fractured rock properties. In addition to these "static" challenges, geologic fractures are always under significant overburden stress, and changes in the stress state can lead to changes in the fracture's ability to conduct fluids. While confining stress has been shown to impact fluid flow through fractures in a fundamental way, the impact of confining stress on transport through fractured rock remains largely unexplored. The link between anomalous (non-Fickian) transport and confining stress has been shown only recently, at the level of a single rough fracture [1]. Here, we investigate the impact of confining stress on flow and transport through discrete fracture networks. We model geomechanical effects in 2D fractured rock by means of a finite-discrete element method (FEMDEM), which can capture the deformation of matrix blocks, reactivation and propagation of cracks. We implement a joint constitutive model within the FEMDEM framework to simulate the effect of fracture roughness. We apply the model to a fracture network extracted from the geological map of an actual outcrop to obtain the aperture field at different stress conditions (Figure 1). We then simulate fluid flow and particle transport through the stressed fracture networks. We observe that anomalous transport emerges in response to confining stress on the fracture networks, and show that this anomalous behavior can be linked to the stress state of the rock. Finally, we develop an effective transport model that captures the anomalous transport through stressed fractures. Our results point to a heretofore unrecognized link between geomechanics and anomalous transport in discrete fractured networks. [1] P. K. Kang, S. Brown, and R. Juanes, Emergence of anomalous transport in stressed

  2. Rock physical aspects of CO{sub 2} injection in chalk

    Energy Technology Data Exchange (ETDEWEB)

    Alam, M.M.

    2011-04-15

    Impact of supercritical CO{sub 2} on the petrophysical and rock-mechanics properties of Ekofisk Formation and Tor Formation chalk from South Arne field, Danish North Sea, chalk was investigated. A series of laboratory experiments was performed on core material collected from the reservoir zone of the South Arne field in order to reveal the changes with respect to porosity, specific surface, pore stiffness, wettability, mineralogy and mechanical failure. In addition, a theoretical rock physical background was also established in order to be able to make sensible interpretation of laboratory data. Sound wave velocity was used as the central tool to study any change in petrophysical and rock mechanical properties. The main focus was to achieve a better understanding of effective stress coefficient (also known as Biot's coefficient); by means of which effective stress can be predicted more accurately. Independent theoretical studies were made on diagenesis, surface properties and stiffness of chalk and their relation with sonic velocity (or Biot's coefficient calculated from sonic velocity). The knowledge and experience from these studies was combined to achieve the main research objective of monitoring changes in hydrocarbon reservoirs in chalk due to CO{sub 2} injection. In order to understand the development of chalk from calcareous ooze and achieving pore stiffness, the diagenesis process of a sedimentary sequence from Kerguelen Plateau in the Indian Ocean was studied. The principal objective of the study was to explore how different porosity reduction mechanisms change the strength of these deep sea carbonate-rich sediments and how these mechanisms can be traced from the change in Biot's coefficient, alpha. In calcareous ooze, alpha was found close to one. Mechanical compaction reduces porosity, but only leads to a minor decrease in alpha. Recrystallization process renders particles smoother, but do not lead to reduction in alpha unless it gives

  3. Programming Entity Framework

    CERN Document Server

    Lerman, Julia

    2010-01-01

    Get a thorough introduction to ADO.NET Entity Framework 4 -- Microsoft's core framework for modeling and interacting with data in .NET applications. The second edition of this acclaimed guide provides a hands-on tour of the framework latest version in Visual Studio 2010 and .NET Framework 4. Not only will you learn how to use EF4 in a variety of applications, you'll also gain a deep understanding of its architecture and APIs. Written by Julia Lerman, the leading independent authority on the framework, Programming Entity Framework covers it all -- from the Entity Data Model and Object Service

  4. Rock stars for the day

    CERN Multimedia

    Stefania Pandolfi

    2015-01-01

    After a two-year hiatus, the CERN Hardronic Festival is back! On 8 August, ten CERN MusiClub bands will take to the stage for the popular event. As usual, the non-stop show will take place on the terrace of Restaurant 3 and will run until after midnight.   The Canettes Blues Band, part of the CERN MusiClub, performing live on the Music In The Park stage at the Montreux Jazz Festival, on 18 July 2013. A large range of musical styles will entertain the audience: from Irish folk, via 70s/80s/90s rock, to pop, blues and R&B. Alongside the music there will be activities for kids and food and drink stands. This year, the income from food sales will be donated to charity. The spirit that has characterised the festival ever since the first event in 1989 is that of a staff party. Any band who volunteers to play also helps to organise the event and set up the stage. “This is a really good thing because a festival that has been growing for many years requires a considerable amount of har...

  5. Reappraisal of hydrocarbon biomarkers in Archean rocks.

    Science.gov (United States)

    French, Katherine L; Hallmann, Christian; Hope, Janet M; Schoon, Petra L; Zumberge, J Alex; Hoshino, Yosuke; Peters, Carl A; George, Simon C; Love, Gordon D; Brocks, Jochen J; Buick, Roger; Summons, Roger E

    2015-05-12

    Hopanes and steranes found in Archean rocks have been presented as key evidence supporting the early rise of oxygenic photosynthesis and eukaryotes, but the syngeneity of these hydrocarbon biomarkers is controversial. To resolve this debate, we performed a multilaboratory study of new cores from the Pilbara Craton, Australia, that were drilled and sampled using unprecedented hydrocarbon-clean protocols. Hopanes and steranes in rock extracts and hydropyrolysates from these new cores were typically at or below our femtogram detection limit, but when they were detectable, they had total hopane (hydrocarbons and diamondoids, which exceed blank concentrations, exhibit individual concentrations up to 80 ng per gram of rock in rock extracts and up to 1,000 ng per gram of rock in hydropyrolysates from the ultraclean cores. These results demonstrate that previously studied Archean samples host mixtures of biomarker contaminants and indigenous overmature hydrocarbons. Therefore, existing lipid biomarker evidence cannot be invoked to support the emergence of oxygenic photosynthesis and eukaryotes by ∼ 2.7 billion years ago. Although suitable Proterozoic rocks exist, no currently known Archean strata lie within the appropriate thermal maturity window for syngenetic hydrocarbon biomarker preservation, so future exploration for Archean biomarkers should screen for rocks with milder thermal histories.

  6. Rock cavern storage of spent fuel

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Won Jin; Kim, Kyung Soo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kwon, Sang Ki [Inha University, Incheon (Korea, Republic of)

    2015-12-15

    The rock cavern storage for spent fuel has been assessed to apply in Korea with reviewing the state of the art of the technologies for surface storage and rock cavern storage of spent fuel. The technical feasibility and economic aspects of the rock cavern storage of spent fuel were also analyzed. A considerable area of flat land isolated from the exterior are needed to meet the requirement for the site of the surface storage facilities. It may, however, not be easy to secure such areas in the mountainous region of Korea. Instead, the spent fuel storage facilities constructed in the rock cavern moderate their demands for the suitable site. As a result, the rock cavern storage is a promising alternative for the storage of spent fuel in the aspect of natural and social environments. The rock cavern storage of spent fuel has several advantages compared with the surface storage, and there is no significant difference on the viewpoint of economy between the two alternatives. In addition, no great technical difficulties are present to apply the rock cavern storage technologies to the storage of domestic spent fuel.

  7. The Usability of Rock-Like Materials for Numerical Studies on Rocks

    Science.gov (United States)

    Zengin, Enes; Abiddin Erguler, Zeynal

    2017-04-01

    The approaches of synthetic rock material and mass are widely used by many researchers for understanding the failure behavior of different rocks. In order to model the failure behavior of rock material, researchers take advantageous of different techniques and software. But, the majority of all these instruments are based on distinct element method (DEM). For modeling the failure behavior of rocks, and so to create a fundamental synthetic rock material model, it is required to perform related laboratory experiments for providing strength parameters. In modelling studies, model calibration processes are performed by using parameters of intact rocks such as porosity, grain size, modulus of elasticity and Poisson ratio. In some cases, it can be difficult or even impossible to acquire representative rock samples for laboratory experiments from heavily jointed rock masses and vuggy rocks. Considering this limitation, in this study, it was aimed to investigate the applicability of rock-like material (e.g. concrete) to understand and model the failure behavior of rock materials having complex inherent structures. For this purpose, concrete samples having a mixture of %65 cement dust and %35 water were utilized. Accordingly, intact concrete samples representing rocks were prepared in laboratory conditions and their physical properties such as porosity, pore size and density etc. were determined. In addition, to acquire the mechanical parameters of concrete samples, uniaxial compressive strength (UCS) tests were also performed by simultaneously measuring strain during testing. The measured physical and mechanical properties of these extracted concrete samples were used to create synthetic material and then uniaxial compressive tests were modeled and performed by using two dimensional discontinuum program known as Particle Flow Code (PFC2D). After modeling studies in PFC2D, approximately similar failure mechanism and testing results were achieved from both experimental and

  8. "All Yugoslavia Is Dancing Rock and Roll"

    DEFF Research Database (Denmark)

    Jovanovic, Zlatko

    The thesis examines the sense of Yugoslav-ness in the Yugoslav rock music culture in the specific socio-politico-economic situation of 1980s Yugoslavia. The main question in the thesis focuses on how this sense of community was caught up in the system of references to the country’s specific...... with the arrival of New Wave into the country in the late 1970s. The study is carried through micro-historical analyses of the local rock scenes in the country’s four principal rock centres: Belgrade, Zagreb, Sarajevo and Ljubljana. The scenes are used as empirical platforms for discussing broader issues...

  9. Acoustics in rock and pop music halls

    DEFF Research Database (Denmark)

    Adelman-Larsen, Niels Werner; Thompson, Eric Robert; Gade, Anders Christian

    2007-01-01

    The existing body of literature regarding the acoustic design of concert halls has focused almost exclusively on classical music, although there are many more performances of rhythmic music, including rock and pop. Objective measurements were made of the acoustics of twenty rock music venues...... in Denmark and a questionnaire was used in a subjective assessment of those venues with professional rock musicians and sound engineers. Correlations between the objective and subjective results lead, among others, to a recommendation for reverberation time as a function of hall volume. Since the bass...

  10. Sliding rocks on Racetrack Playa, Death Valley National Park: first observation of rocks in motion.

    Directory of Open Access Journals (Sweden)

    Richard D Norris

    Full Text Available The engraved trails of rocks on the nearly flat, dry mud surface of Racetrack Playa, Death Valley National Park, have excited speculation about the movement mechanism since the 1940s. Rock movement has been variously attributed to high winds, liquid water, ice, or ice flotation, but has not been previously observed in action. We recorded the first direct scientific observation of rock movements using GPS-instrumented rocks and photography, in conjunction with a weather station and time-lapse cameras. The largest observed rock movement involved > 60 rocks on December 20, 2013 and some instrumented rocks moved up to 224 m between December 2013 and January 2014 in multiple move events. In contrast with previous hypotheses of powerful winds or thick ice floating rocks off the playa surface, the process of rock movement that we have observed occurs when the thin, 3 to 6 mm, "windowpane" ice sheet covering the playa pool begins to melt in late morning sun and breaks up under light winds of -4-5 m/s. Floating ice panels 10 s of meters in size push multiple rocks at low speeds of 2-5 m/min. along trajectories determined by the direction and velocity of the wind as well as that of the water flowing under the ice.

  11. A Novel Mobile Testing Equipment for Rock Cuttability Assessment: Vertical Rock Cutting Rig (VRCR)

    Science.gov (United States)

    Yasar, Serdar; Yilmaz, Ali Osman

    2017-04-01

    In this study, a new mobile rock cutting testing apparatus was designed and produced for rock cuttability assessment called vertical rock cutting rig (VRCR) which was designed specially to fit into hydraulic press testing equipment which are available in almost every rock mechanics laboratory. Rock cutting trials were initiated just after the production of VRCR along with calibration of the measuring load cell with an external load cell to validate the recorded force data. Then, controlled rock cutting tests with both relieved and unrelieved cutting modes were implemented on five different volcanic rock samples with a standard simple-shaped wedge tool. Additionally, core cutting test which is an important approach for roadheader performance prediction was simulated with VRCR. Mini disc cutters and point attack tools were used for execution of experimental trials. Results clearly showed that rock cutting tests were successfully realized and measuring system is delicate to rock strength, cutting depth and other variables. Core cutting test was successfully simulated, and it was also shown that rock cutting tests with mini disc cutters and point attack tools are also successful with VRCR.

  12. COMPARISON OF GEO-MECHANICAL PROPERTIES OF WHITE ROCK SALT AND PINK ROCK SALT IN KŁODAWA SALT DIAPIR

    National Research Council Canada - National Science Library

    Malwina Kolano; Danuta Flisiak

    2013-01-01

    .... The present article introduces strength-strain properties of white rock salt, building the nucleus of northeastern edge anticline, and pink rock salt that belongs to the series of youngest rock salt...

  13. The ARCON modeling framework

    NARCIS (Netherlands)

    Afsarmanesh, H.; Camarinha-Matos, L.M.; Camarinha-Matos, L.M.; Afsarmanesh, H.

    2008-01-01

    A framework is defined for ARCON reference modeling, introducing multiple modeling perspectives of: Environment characteristics, life cycle stages, and modeling intents. This novel modeling framework takes into account contributions from previous related works, mainly on enterprise modeling, and

  14. Investigating the Effect of Saturation and Wettability on Spectral Induced Polarization of Biodegraded Oil in Porous Media

    Science.gov (United States)

    Abdel Aal, G. Z.; Atekwana, E. A.

    2012-12-01

    Spectral induced polarization (SIP) has been suggested as the technique most sensitive to the presence of contaminants as well as accompanying bio-physicochemical processes associated with hydrocarbon biodegradation. Previous laboratory investigations have suggested that wettability is an important factor to consider when investigating the SIP response of oil bearing sands. The results to date provide experimental data for mostly fresh oil. However, these results differ significantly from field investigations where the oil is mostly in the degraded form. In this study we extend the work of Schmutz and others and Revil and others by investigating the SIP response of biodegraded oil in porous media. Laboratory experiments were conducted to investigate the effect of different oil saturation (0.2-0.8) and wettability (water wet and oil wet) on SIP of biodegraded and fresh oil in sand columns. The laboratory experiments were performed using a sand column filled with a mix of oil, artificial ground water (AGW) with a conductivity of 0.01 S/m and fine sands. Each experiment was conducted with clean sands mixed with oil (oil wet case) or AGW (water wet case). The proportions of oil and water were calculated to obtain the desired oil and water saturations, and using the same amount of sand. SIP measurements were made using a National Instruments NI 4551 dynamic signal analyzer and four electrodes technique. Phase shift between current stimulus-voltage signal and conductivity magnitude were measured between 0.1 and 1000 Hz and the real and imaginary components of the complex surface conductivity were calculated. The same experimental procedure was repeated using fresh oil as background and for comparison with biodegraded oil results. The results show that when water is the wetting phase, there is no significant difference in the IP parameters measured for both the fresh and degraded oil. Furthermore, both the fresh and biodegraded oil showed an increase in the magnitude of

  15. Biogenic Cracks in Porous Rock

    Science.gov (United States)

    Hemmerle, A.; Hartung, J.; Hallatschek, O.; Goehring, L.; Herminghaus, S.

    2014-12-01

    Microorganisms growing on and inside porous rock may fracture it by various processes. Some of the mechanisms of biofouling and bioweathering are today identified and partially understood but most emphasis is on chemical weathering, while mechanical contributions have been neglected. However, as demonstrated by the perseverance of a seed germinating and cracking up a concrete block, the turgor pressure of living organisms can be very significant. Here, we present results of a systematic study of the effects of the mechanical forces of growing microbial populations on the weathering of porous media. We designed a model porous medium made of glass beads held together by polydimethylsiloxane (PDMS), a curable polymer. The rheological properties of the porous medium, whose shape and size are tunable, can be controlled by the ratio of crosslinker to base used in the PDMS (see Fig. 1). Glass and PDMS being inert to most chemicals, we are able to focus on the mechanical processes of biodeterioration, excluding any chemical weathering. Inspired by recent measurements of the high pressure (~0.5 Mpa) exerted by a growing population of yeasts trapped in a microfluidic device, we show that yeast cells can be cultured homogeneously within porous medium until saturation of the porous space. We investigate then the effects of such an inner pressure on the mechanical properties of the sample. Using the same model system, we study also the complex interplay between biofilms and porous media. We focus in particular on the effects of pore size on the penetration of the biofilm within the porous sample, and on the resulting deformations of the matrix, opening new perspectives into the understanding of life in complex geometry. Figure 1. Left : cell culture growing in a model porous medium. The white spheres represent the grains, bonds are displayed in grey, and microbes in green. Right: microscopy picture of glass beads linked by PDMS bridges, scale bar: 100 μm.

  16. Physiology of difficult rock climbing.

    Science.gov (United States)

    Watts, Phillip B

    2004-04-01

    The purpose of this review is to explore existing research on the physiological aspects of difficult rock climbing. Findings will be categorized into the areas of an athlete profile and an activity model. An objective here is to describe high-level climbing performance; thus the focus will primarily be on studies that involve performances at the 5.11/6c (YDS/French) level of difficulty or higher. Studies have found climbers to be small in stature with low body mass and low body fat. Although absolute strength values are not unusual, strength to body mass ratio is high in accomplished climbers. There is evidence that muscular endurance and high upper body power are important. Climbers do not typically possess extremely high aerobic power, typically averaging between 52-55 ml.kg(-1).min(-1) for maximum oxygen uptake. Performance time for a typical ascent ranges from 2 to 7 min and oxygen uptake (VO2) averages around 20-25 ml.kg(-1).min(-1) over this period. Peaks of over 30 ml.kg(-1).min(-1) for VO2 have been reported. VO2 tends to plateau during sustained climbing yet remains elevated into the post-climb recovery period. Blood lactate accumulates during ascent and remains elevated for over 20 min post-climbing. Handgrip endurance decreases to a greater degree than handgrip strength with severe climbing. On the basis of this review, it appears that a specific training program for high-level climbing would include components for developing high, though not elite-level, aerobic power; specific muscular strength and endurance; ATP-PC and anaerobic glycolysis system power and capacity; and some minimum range of motion for leg and arm movements.

  17. Corrosion, wettability and thrombogenicity investigation of ion beam modified HAP/Al{sub 2}O{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Shikha, Deep; Shahid, Md.; Jha, Ush [Department of Chemistry, BIT Mesra, Ranchi 835215 (India); Sinha, Sanjay Kumar, E-mail: sksinha@bitmesra.ac.in [Department of Physics, BIT Mesra, Ranchi 835215 (India); Reddy, V. Raghavendra [UGC-DAE Consortium for Scientific Research Indore (India); Ojha, Sunil; Kumar, P.; Kanjilal, Dinakar [IUAC, Aruna Asaf Ali road, New Delhi (India)

    2015-08-01

    Hydroxyapatite Ca{sub 10}(PO4){sub 6}(OH){sub 2}, is a biosensitive ceramic which promotes bone growth in human fluid. However due to its weak mechanical strength it is often coated on chemically inert material such as alumina. In the present work hydroxyapatite (HAP) of thickness 1 μm is deposited on alumina using sol–gel process and the stoichiometric ratio of Ca:P = 1.67 is maintained. Surface property of HAP is further improved by Ar{sup +} ion implantation. The samples were irradiated with 1.4 MeV Ar{sup +} ions with fluence ranging from 5 × 10{sup 14} to 1 × 10{sup 16} ions/cm{sup 2}. After irradiation, the surface is characterized using Atomic Force Microscope (AFM), Scanning Electron Microscope (SEM), electron dispersive X-ray spectroscopy (EDX), Glancing incidence X-ray diffraction (GXRD) and Rutherford backscattering Spectroscopy (RBS) techniques. Corrosion resistances and impedance analysis were carried out in Ringer solution. RBS and EDX were used to confirm the stoichiometric ratio of the film. Compound formation before and after ion implantation was studied using GXRD. Nanohardness, wettability and thrombogenicity of all the samples were studied. Correlation among surface morphology, improvement in corrosion resistance, hardness, wetability and thrombogenicity before and after ion implantation are discussed in this paper. - Highlights: • .People have worked on HAP coated on metallic alloy and even alumina but the characterization done here are all different. • Throbmobogenicity, corrosion resistance and wetability have all been carried out first time. • Improvement of Surface and interface using energetic inert ions like argon is carried out first time. • The best ion fluence for orthopaedic implants is proposed.

  18. Laser shock peening without coating induced residual stress distribution, wettability characteristics and enhanced pitting corrosion resistance of austenitic stainless steel

    Science.gov (United States)

    Prabhakaran, S.; Kulkarni, Aniket; Vasanth, G.; Kalainathan, S.; Shukla, Pratik; Vasudevan, Vijay K.

    2018-01-01

    Low energy laser shock peening without coating (LSPwC) was conducted on AISI 304 austenitic stainless steel specimens with varying pulse densities or overlapping. Highest magnitude of compressive residual stress (CRS) was achieved for an optimized pulse density of 2500 pulses/cm2 (75% overlapping). The 2-D and 3-D topographical analysis were indicative of the fact that controlled roughening of the surface was achieved after the LSPwC process. After the LSPwC process, the hydrophilic unpeened surface was converted into the hydrophobic surface, thus decreasing the wettability characteristics of the surface. The X-ray diffraction (XRD) results reveal that there is a beginning of the martensite transformation and the rise in the intensity value of the peaks after LSPwC indicates the presence of compressive residual stresses induced in the specimen. The optical microscope and high-resolution transmission electron microscope results provided evidence of grain refinement and deformation induced refinement features such as multidirectional mechanical twinning, dislocations lines, micro shear cells and stacking faults in the near and sub-surface areas. The average hardness value of the LSPwC specimens was found to be increased by 28% more than the untreated specimen. The potentiodynamic polarization revealed that there was a considerable amount of increase in the pitting corrosion resistance after the LSPwC process, thus, supporting to extend the fatigue life of the specimen. The electrochemical impedance spectroscopic (EIS) analysis depicts that the LSPwC process supports the formation of the strong passivation layer in 3.5% NaCl solution.

  19. One-step synthesis, wettability and foaming properties of high-performance non-ionic hydro-fluorocarbon hybrid surfactants

    Science.gov (United States)

    Peng, Ying-ying; Lu, Feng; Tong, Qing-Xiao

    2018-03-01

    In this work, a series of non-ionic hydro-fluorocarbon hybrid surfactants (C9F19CONH(CH2)3N(CmH2m+1)2, abbreviated as C9F19AM (m = 1), C9F19AE (m = 2) and C9F19AB (m = 4) were easily synthesized by one-step reaction and characterized by 1HNMR, 19FNMR and MS spectroscopy. Unlike conventional non-ionic surfactants (most hydrophilic units consisted of hydroxy or ether groups), their hydrophilic groups were composed of amide group, an eco-friendly unit. The surface activity, wettability, thermal stability and foaming performance were investigated. The results showed that the C9F19AE (C9F19CONH(CH2)3N[CH2CH3]2) had superior surface and interface activities, which could reduce the surface tension of water down to 15.37 mN/m and the interfacial tension (cyclohexane/water/surfactants) to 5.8 mN/m with a low cmc (critical micelle concentration) of 0.12 mmol/L. Through the calculation of Amin (the minimum area occupied per-surfactant molecule), we speculated this higher surface activity was related to the compatibility between hydrocarbon and fluorocarbon chains. When used as wetting and foaming agents, the C9F19AE also outperformed great advantages over conventional non-ionic fluorocarbon and hydrocarbon surfactants, which could decrease the contact angle of water on PTFE plate from 107.7° to 3.6°, and increase the foam integrated value F to 536 500 ± 3066.5 mL s. Moreover, the decomposition temperature (Td) of C9F19AE could reach up to 173 °C. This work demonstrates a valuable strategy to develop a kind of high-efficiency foaming agent via facile synthesis.

  20. Barnacle settlement and the adhesion of protein and diatom microfouling to xerogel films with varying surface energy and water wettability.

    Science.gov (United States)

    Finlay, John A; Bennett, Stephanie M; Brewer, Lenora H; Sokolova, Anastasiya; Clay, Gemma; Gunari, Nikhil; Meyer, Anne E; Walker, Gilbert C; Wendt, Dean E; Callow, Maureen E; Callow, James A; Detty, Michael R

    2010-08-01

    Previous work has shown that organosilica-based xerogels have the potential to control biofouling. In this study, modifications of chemistry were investigated with respect to their resistance to marine slimes and to settlement of barnacle cyprids. Adhesion force measurements of bovine serum albumin (BSA)-coated atomic force microscopy (AFM) tips to xerogel surfaces prepared from aminopropylsilyl-, fluorocarbonsilyl-, and hydrocarbonsilyl-containing precursors, indicated that adhesion was significantly less on the xerogel surfaces in comparison to a poly(dimethylsiloxane) elastomer (PDMSE) standard. The strength of adhesion of BSA on the xerogels was highest on surfaces with the highest and the lowest critical surface tensions, gamma(C) and surface energies, gamma(S), and duplicated the 'Baier curve'. The attachment to and removal of cells of the diatom Navicula perminuta from a similar series of xerogel surfaces were examined. Initial attachment of cells was comparable on all of the xerogel surfaces, but the percentage removal of attached cells by hydrodynamic shear stress increased with gamma(C) and increased wettability as measured by the static water contact angle, theta(Ws), of the xerogel surfaces. The percentage removal of cells of Navicula was linearly correlated with both properties (R(2) = 0.74 for percentage removal as a function of theta(Ws) and R(2) = 0.69 for percentage removal as a function of gamma(C)). Several of the aminopropylsilyl-containing xerogels showed significantly greater removal of Navicula compared to a PDMSE standard. Cypris larvae of the barnacle B. amphitrite showed preferred settlement on hydrophilic/higher energy surfaces. Settlement was linearly correlated with theta(Ws) (R(2) = 0.84) and gamma(C) (R(2) = 0.84). Hydrophilic xerogels should prove useful as coatings for boats in regions where fouling is dominated by microfouling (protein and diatom slimes).