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Sample records for fabric air permeability

  1. Absorption and Permeability of Air-jet Textured Glass Fiber Yarn and Its Fabric for Resin

    Institute of Scientific and Technical Information of China (English)

    马会英; 隋全侠; 邹祖伟

    2003-01-01

    The Absorption and permeability of air-jet textured glass fiber yarn and its fabric and bonded tenacity of the fabric have been studied in relation to the main parameters, air supplied pressure and overfeed ratio.It has been observed that increasing the level of main parameters improves the coated ratio of the textured yarn and its fabric as well as the bonded tenacity of the fabric made of textured yarn. Comparison of absorption or permeability between textured and supplied yarns, and comparison of absorption or permeability and bonded tenacity between the two kinds of fabrics have been elucidated.

  2. Influence of Shrinkage on Air and Water Vapour Permeability of Double-Layered Weft Knitted Fabrics

    Directory of Open Access Journals (Sweden)

    Asta BIVAINYTĖ

    2012-09-01

    Full Text Available Water vapour permeability and transport depends on the properties of the fibre and knitted fabric structure. It was designed double-layered fabrics knitted in plain plating pattern whose inner side was  made from synthetic fibres the PES, PA, PP, and Coolmax® (tetra-channel fibres by DuPont which do not absorb moisture and on the surface of the wear – natural cotton and bamboo fibres which have good absorption properties. In the present research it was established that the air permeability of all fabrics after washing and drying cycle decreased. It occurred because of the influence of shrinkage during washing and drying under the impact of moisture, heat, and mechanical action. After washing and drying cycle, the water vapour permeability of fabrics knitted from bamboo and synthetic yarns blend decreased predominantly and became similar to fabrics knitted from cotton and respective synthetic yarns blend. The water vapour permeability of fabrics knitted from cotton and synthetic yarns blend decreased significant less. Depending on the knitting structure, the most decrease of water vapour permeability was estimated to the plain plated fabrics.DOI: http://dx.doi.org/10.5755/j01.ms.18.3.2438

  3. Effect of Polyvinylpyrrolidone on the Morphologies of Latex Films and Air Permeability of the Latex Finished Fabrics

    Institute of Scientific and Technical Information of China (English)

    SHEN Yi-feng; YE Jia-jia; YANG Lei; WU Ming-hua; NI Tian-xiang

    2010-01-01

    Low air permeability is a common problem happening to the coating finished and pigment dyed fabrics.To tackle the problem,styrene and butyl acrylate copolymer latex was prepared and used as substitute for the binder.Then,polyvinylpyrrolidoue(PVP)was fed into the latex.It was expected that pores could form in the resulting latex film after being rinsed.The morphologies of the latex films were analysized by scanning electric microscope(SEM).It was found that the continuity of the latex films decreased greatly because of the addition of PVP,leading to the loss of the stress at break of the films.After rinsing with methanol aqueous solution,PVP was easily leached off and(macro)void was formed in the latex films.The size of the void decreased with the increase of the PVP concentration.Then,the latex with and without PVP was used to finish the cotton fabrics and engaged as binder in pigment dyeing.After PVP was rinsed out,the air permeability of the fabrics improved greatly,which recovered to that of the unfinished one.In the meantime,the color fastness to rubbing was little affected.So,the method of PVP addition could be termed as an efficient way to improve the air permeability in coating and dyeing industry.

  4. Macro fluid analysis of laminated fabric permeability

    Directory of Open Access Journals (Sweden)

    Qiu Li

    2016-01-01

    Full Text Available A porous jump model is put forward to predict the breathability of laminated fabrics by utilizing fluent software. To simplify the parameter setting process, the methods of determining the parameters of jump porous model by means of fabric layers are studied. Also, effects of single/multi-layer fabrics and thickness on breathability are analyzed, indicating that fabric breathability reduces with the increase of layers. Multi-layer fabric is simplified into a single layer, and the fabric permeability is calculated by proportion. Moreover, the change curve of fabric layer and face permeability, as well as the equation between the fabric layer and the face permeability are obtained. Then, face permeability and pressure-jump coefficient parameters setting of porous jump model could be integrated into single parameter (i. e. fabric layers, which simplifies the fluent operation process and realizes the prediction of laminated fabric permeability.

  5. Permeability of Non-Crimp Fabric Preforms

    NARCIS (Netherlands)

    Loendersloot, Richard; Lomov, Stepan V.

    2011-01-01

    Experimental permeability data of non-crimp fabrics (NCFs) is discussed in this chapter. The chapter starts with a general introduction on permeability, followed by a discussion on experimental permeability data. The infl uence of geometrical features of the textile architecture, in particular the s

  6. An apparatus for determining water vapour permeability of fabrics

    Directory of Open Access Journals (Sweden)

    B. L. Saksena

    1955-04-01

    Full Text Available An apparatus for the determination of water vapour permeability (W.V.P. of fabrics is described. The fabric partitions a closed space into two compartments in which are circulated air streams having high and low water vapour pressure respectively, without any overall pressure or temperature difference. The transfer of moisture from the high to the low humidity side of the fabric is gravimetrically measured. Results of tests are given.

  7. Experimental Research on Permeability of Airbag Fabrics at High Pressure Differential

    Institute of Scientific and Technical Information of China (English)

    WANG Xin-hou

    2004-01-01

    The air permeability of airbag fabrics was measured at high pressure differential up to 200kPa. It was found that permeability varied with pressure differential nonlinearly. The relationship between air permeability and the pressure differential was fitted well with power law curve. The study revealed that the coefficient c and exponent b in the power law equation had a strong correlation with porosity, which was chosen to characterize the airbag fabrics.

  8. Projection pursuit regression model for prediction of air permeability of woven fabrics%机织物透气性预测的投影寻踪回归模型

    Institute of Scientific and Technical Information of China (English)

    王健; 张晓丽; 刘陶

    2011-01-01

    In view of the difficulty in nonlinear modeling for prediction of woven fabric permeability, a projection pursuit regression ( PPR) model for prediction of air permeability of woven fabrics was established using the structural parameters such as the total tightness, thickness, and weight per square meter and average float as factors affecting the prediction of woven fabric permeability. The fitted values of tested samples and the predicted values of trained samples were analyzed with the means and standard deviations of relative error as the indicators and were compared with the results of BP neural network and multiple linear regression model. The results showed that the PPR model fitting and prediction accuracy was better than those of BP neural network and multiple linear regression model. In the case of less trained samples, the PPR model still had relatively high prediction accuracy and good generalization ability, providing a novel approach to the prediction of woven fabric permeability.%针对机织物透气性预测中存在非线性建模困难的问题,选择机织物总紧度、厚度、面密度及平均浮长等结构参数作为机织物透气性预测的影响因素,建立机织物透气性预测的投影寻踪回归模型.对模型训练样本的拟合值及检验样本的预测值以相对误差的均值及标准差为指标进行分析,并与BP神经网络及多元线性回归模型进行对比.结果表明,投影寻踪回归模型的拟合及预测精度均优于BP神经网络及多元线性回归模型,且在训练样本较少的情况下,投影寻踪回归模型仍有较高的预测精度和较强的泛化能力,可为机织物透气性预测提供一种新的方法.

  9. Investigating the Relationship between Knitted Fabric Porosity and Light Permeability

    Directory of Open Access Journals (Sweden)

    Manoj Kumar Imrith

    2016-01-01

    Full Text Available The present paper attempts to investigate the relationship between fabric porosity and light permeability of the knitted structures, namely, rib 1 × 1, rib 2 × 1, single jersey, and plain structure. The rationale is that pores (in a fabric would allow light to pass through but at the same time provide a quantitative assessment of the UV light permeability of the knitted fabrics, an indication of the protective capacity of the fabrics against UV radiation. The porosity and corresponding light permeability of the knitted structures were measured after varying the following knitting parameters: stitch length, stitch density, and tension on the machine. Furthermore, this work has enabled the development of an apparatus that can measure the amount of light transmitted through the knitted fabrics. The results generated by the equipment were validated through the use of regression equations.

  10. Study on Wet Permeability Models of Yarns and Knitted Fabrics

    Institute of Scientific and Technical Information of China (English)

    王其; 冯勋伟

    2001-01-01

    Water transport through the pore structure of the knitted fabric can occur only in place where the fiber-water surface attraction force is greater than the water weight in the capillary. To investigate wet permeability of the knitted yarn in the fabric, a liquid transport model is established. The main factors which have significant influences on the liquid transport have been analyzed. It is derived from the argument that the optimal design for the knitted fabric with quick sweat transport property can be obtained.

  11. Fractal Derivative Model for Air Permeability in Hierarchic Porous Media

    Directory of Open Access Journals (Sweden)

    Jie Fan

    2012-01-01

    Full Text Available Air permeability in hierarchic porous media does not obey Fick's equation or its modification because fractal objects have well-defined geometric properties, which are discrete and discontinuous. We propose a theoretical model dealing with, for the first time, a seemingly complex air permeability process using fractal derivative method. The fractal derivative model has been successfully applied to explain the novel air permeability phenomenon of cocoon. The theoretical analysis was in agreement with experimental results.

  12. Air-Inflated Fabric Structures

    Science.gov (United States)

    2006-11-05

    inflatable boats, temporary bridging, and energy absorbers such as automotive air bags. However, the advent of today’s high performance fibers...were constructed using adhesively bonded, piece-cut manufacturing methods. These methods were limited to relatively low pressures because of fabric...environmental exposure to ultraviolet rays, moisture, fire, chemicals, etc. Coating such as urethane , PVC (polyvinyl chloride), neoprene, EPDM (ethylene

  13. A Design Tool for Clothing Applications: Wind Resistant Fabric Layers and Permeable Vents

    Directory of Open Access Journals (Sweden)

    Phillip Gibson

    2014-01-01

    Full Text Available A computational clothing design tool is used to examine the effects of different clothing design features upon performance. Computational predictions of total heat and mass transfer coefficients of the clothing design tool showed good agreement with experimental measurements obtained using a sweating thermal manikin for four different clothing systems, as well as for the unclothed bare manikin. The specific clothing design features examined in this work are the size and placement of air-permeable fabric vents in a protective suit composed primarily of a fabric-laminated polymer film layer. The air-permeable vents were shown to provide additional ventilation and to significantly decrease both the total thermal insulation and the water vapor resistance of the protective suit.

  14. Air sparging in low permeability soils

    Energy Technology Data Exchange (ETDEWEB)

    Marley, M.C. [Envirogen, Inc., Canton, MA (United States)

    1996-08-01

    Sparging technology is rapidly growing as a preferred, low cost remediation technique of choice at sites across the United States. The technology is considered to be commercially available and relatively mature. However, the maturity is based on the number of applications of the technology as opposed to the degree of understanding of the mechanisms governing the sparging process. Few well documented case studies exist on the long term operation of the technology. Sparging has generally been applied using modified monitoring well designs in uniform, coarse grained soils. The applicability of sparging for the remediation of DNAPLs in low permeability media has not been significantly explored. Models for projecting the performance of sparging systems in either soils condition are generally simplistic but can be used to provide general insight into the effects of significant changes in soil and fluid properties. The most promising sparging approaches for the remediation of DNAPLs in low permeability media are variations or enhancements to the core technology. Recirculatory sparging systems, sparging/biosparging trenches or curtains and heating or induced fracturing techniques appear to be the most promising technology variants for this type of soil. 21 refs., 9 figs.

  15. The system of thermoelectric air conditioning based on permeable thermoelements

    Directory of Open Access Journals (Sweden)

    Cherkez R. G.

    2009-04-01

    Full Text Available There is thermoelectric air conditioner unit on the basis of permeable cooling thermoelements presented. In thermoelectric air conditioner unit the thermoelectric effects and the Joule–Thomson effect have been used for the air stream cooling. There have been described the method of temperature distribution analysis, the determinations of energy conversion power characteristics and design style of permeable thermoelement with maximum coefficient of performance described. The results of computer analysis concerning the application of the thermoelement legs material on the basis of Bi2Te3 have shown the possibility of coefficient of performance increase by a factor of 1,6—1,7 as compared with conventional thermoelectric systems.

  16. Wet Permeability and Moisture Vapor Transmission Characteristics of Soybean Knitted Fabrics

    Institute of Scientific and Technical Information of China (English)

    王其; 冯勋伟

    2001-01-01

    Wet permeability of fibrous assembly is mainly influenced by the properties of liquid and the configurations of the fiber which consist of diameter of fiber, twist angle and fiber alignment in a yarn. It can be seen from experimental results that the knitted fabric made of soybean (SB) fiber has goodproperties both in wet permeability and vapor transmission so that the knitting technology and fabric characteristics can be improved.

  17. A biomimic thermal fabric with high moisture permeability

    Directory of Open Access Journals (Sweden)

    Fan Jie

    2013-01-01

    Full Text Available Moisture comfort is an essential factor for functional property of thermal cloth, especially for thick thermal cloth, since thick cloth may hinder effective moisture permeation, and high moisture concentration in the micro-climate between skin and fabric would cause cold feeling. Here, we report a biomimic thermal fabric with excellent warm retention and moisture management properties. In this fabric, the warp yarn system constructs many tree-shaped channel nets in the thickness direction of the fabric. Experimental result indicates that the special hierarchic configuration of warp yarns endows the biomimic thermal fabric with a better warm retention and water vapor management properties compared with the traditional fabrics.

  18. Effect of the aggregate grading on the concrete air permeability

    Directory of Open Access Journals (Sweden)

    Argiz, C.

    2014-09-01

    Full Text Available Great durability problems are being found in concrete structures related to the penetrability of aggressive agents through the concrete (ie. chloride penetration, sulphate attack, carbonation, freezing and thawing, and so on. Air permeability coefficient is used as an effective tool to estimate the potential durability of concrete structures due to its direct relation with the microstructure and the moisture content. This paper discusses the effect of the aggregate grading and water/cement ratio on the air permeability coefficient. An aggregate grading with more sand than coarse aggregates has resulted more beneficial from the point of view of concrete air permeability. This fact can be attributed to a denser skeleton formed by the finer aggregates. With fine aggregates, the higher water/cement ratio, the lower air permeability. However, the contrary was found with coarse aggregates. Overall, a temperature increase from 20 °C to 60 °C during preconditioning led to a Dair increase of 40–80%.Se han encontrado una gran cantidad de problemas de durabilidad de estructuras de hormigón relacionados con la penetración de agentes agresivos externos (es decir, penetración de cloruros, ataque por sulfatos, carbonatación, hielo-deshielo, etc.. El coeficiente de permeabilidad al aire se utiliza como una herramienta eficaz para estimar la durabilidad potencial de las estructuras de hormigón debido a su relación directa con su microestructura y contenido de humedad. Se discute el efecto de la gradación de los áridos y relación agua/cemento en el coeficiente de permeabilidad al aire. Con áridos más finos que gruesos, el resultado es más beneficioso, lo que se atribuye a que la arena forma un esqueleto más denso. Con áridos más finos, al aumentar la relación agua/cemento, disminuye la permeabilidad al aire; pero con áridos más gruesos se ha observado lo contrario. Cuando se pre-acondiciona de 20 °C a 60 °C, se produce un aumento del Dair

  19. A new test method for measuring the water vapour permeability of fabrics

    Science.gov (United States)

    Huang, Jianhua; Qian, Xiaoming

    2007-09-01

    The water vapour permeability of textile fabrics is a critical determinant of wearer comfort. Existing test methods are either time consuming or require large amounts of material. A new test apparatus was developed for characterizing the water vapour permeability of fabrics. An aluminium cylinder covered with waterproof and vapour permeable PTFE laminate is used for generating water vapour source on one side of the sample. A dry nitrogen sweep gas stream is used to carry water vapour away. The calculation of the rate of water vapour transmission across the fabric is based on the measurement of the relative humidity of the outgoing nitrogen stream. This new measuring apparatus offers a short test time and calls for a small sample size. The comparison measurements show that the test results correlated well with those obtained from ISO 11092 and ASTM E96. Therefore, this test method provides a new technique to accurately and precisely characterize the water vapour transport properties of fabrics.

  20. Wet Permeability Characteristics of Double-layer Knitted Fabrics

    Institute of Scientific and Technical Information of China (English)

    WANG Qi; XI Bai-jun

    2007-01-01

    In order to solve the problem that sweat flows back into the internal layer from the external layer in doublelayer knits, a fabric structure model is set up and the conditions that keep the sweat from flowing back into the internal layer from the external layer are presented. It can be used to improve the design of the double-layer knitstheoretically.

  1. Microfluidic fabrication and micromechanics of permeable and impermeable elastomeric microbubbles.

    Science.gov (United States)

    Duncanson, Wynter J; Kodger, Thomas E; Babaee, Sahab; Gonzalez, Grant; Weitz, David A; Bertoldi, Katia

    2015-03-24

    We use droplet microfluidics to produce monodisperse elastomeric microbubbles consisting of gas encapsulated in a polydimethylsiloxane shell. These microbubbles withstand large, repeated deformations without rupture. We perform μN-scale compression tests on individual microbubbles and find their response to be highly dependent on the shell permeability; during deformation, the pressure inside impermeable microbubbles increases, resulting in an exponential increase in the applied force. Finite element models are used to interpret and extend these experimental results enabling the design and development of deformable microbubbles with a predictable mechanical response. Such microbubbles can be designed to repeatedly transit through the narrow constrictions found in a porous medium functioning as probes of the local pressure.

  2. Study on Longitudinal Gas Permeability of Air-dried Masson Pine Sapwood

    Institute of Scientific and Technical Information of China (English)

    HOU Zhuqiang; ZHANG Lifei; GUAN Ning; CHEN Guihua

    2006-01-01

    Measurement of the longitudinal gas permeability was made for air-dried sapwood specimens from Masson pine(Pinus massoniana).Results showed that air-dried Masson pine sapwood was one of the most permeable softwoods.The investigated specimens had an average longitudinal gas permeability of 4.60 ×10-13m3/m.and the permeability ranged from 1.06×10-13 to 1.12 ×10-12m3/m.The Kruskal-Wallis Test indicated that,generally,there was no correlation between the longitudinal gas permeability and the trees from which specimens were prepared,and tree height had no significant effect on the longitudinal gas permeability.

  3. Fibrous fabrics permeability. Study of the discrepancies; Permeabilite des renforts fibreux. Etude des ecarts experiences-predictions

    Energy Technology Data Exchange (ETDEWEB)

    Laine, B.; Boust, F. [Office National d' Etudes et de Recherches Aerospatiales, 92 - Chatillon (France); Boisse, Ph. [Institut National des Sciences Appliquees (INSA), Lab. de Mecanique des Contacts et des Solides (LaMCoS), UMR CNRS 5514, 69 - Villeurbanne (France); Hivet, G.; Laine, B. [Ecole Nationale Superieure de Mecanique et d' Aerotechnique (ENSMA-Polytech' Orleans), Lab. de Mecanique des Systemes et des Procedes, UMR CNRS 8106, (France); Lomov, St. [Katholieke Univ. Leuven, Dept. MTM (Belgium); Fanget, A. [Centre d' Etudes de Gramat, 46 (France)

    2005-07-01

    The knowledge of the fabric permeability is compulsory to simulate the RTM process. We display a 'numerical chain' which allows us to determine the permeability of fibrous fabrics using 3D geometric models. Numerical predictions are compared together with experimental values and microtomography used to validate the geometrical models. The incertitude, errors and statistical variations of the results are considered to explain the observed discrepancies. (authors)

  4. The effect of air permeability and water vapor permeability of cleanroom clothing on physiological responses and wear comfort.

    Science.gov (United States)

    Chen, Te-Hung; Chen, Wan-Ping; Wang, Mao-Jiun J

    2014-01-01

    The function of cleanroom clothing is to protect the product from contamination by people, and to dissipate electrostatic discharge. People in the cleanroom work environment often complain about the discomforts associated with the wearing of cleanroom clothing. The purpose of this study is to investigate the effect of air permeability and water vapor permeability of cleanroom clothing on the subject's physiological and subjective responses. Five male and five female subjects participated in this study. The experimental goal was to simulate the operator's regular tasks in a semiconductor manufacturing cleanroom. Each subject completed three treatment combinations with three different cleanroom clothing types. A three-factor experiment was designed (significance level p = 0.05). The independent variables included gender, cleanroom clothing, and duration. The dependent measures included heart rate, core temperature, skin temperature, micro-climate relative humidity, micro-climate temperature, and subjective responses. A total of 40 min was involved for each treatment condition. The results indicate that skin temperature, micro-climate temperature and micro-climate relative humidity were lower while wearing cleanroom clothing with high air permeability and high water vapor permeability. The significant gender difference was found in skin temperature. As the task time increased, the micro-climate temperature also increased but the micro-climate relative humidity decreased at first and then increased. In addition, the physiological responses showed significant positive correlations with the subjective perception of clothing comfort. The findings of this study may provide useful information for cleanroom clothing design and selection.

  5. Changes in Anatomical Features, Air Permeability and Sound Absorption Capability of Wood Induced by Delignification Treatment

    OpenAIRE

    Kang, Chunwon; Kang, Wook; MATSUMURA, Junji; Oda, KazuYuki

    2008-01-01

    To estimate the possibility of improving the sound absorption capability of wood by delignification treatment, the changes in anatomical features on the cross sectional surface, air permeability in the longitudinal direction and sound absorption capability of wood were evaluated. The intercellular substance gushed out and numerous small cracks were formed on the surface of the delignificated wood. Delignification treatment improved the air permeability of the wood in the longitudinal directio...

  6. Air-Filled porosity and permeability relationships during solid-waste fermentation

    NARCIS (Netherlands)

    Richard, T.L.; Veeken, A.H.M.; Wilde, de V.; Hamelers, H.V.M.

    2004-01-01

    An experimental apparatus was constructed to measure the structural parameters of organic porous media, i.,e. mechanical strength, air-filled porosity, air permeability, and the Ergun particle size. These parameters are critical to the engineering of aerobic bioconversion systems and were measured

  7. Density-Corrected Models for Gas Diffusivity and Air Permeability in Unsaturated Soil

    DEFF Research Database (Denmark)

    Chamindu, Deepagoda; Møldrup, Per; Schjønning, Per

    2011-01-01

    Accurate prediction of gas diffusivity (Dp/Do) and air permeability (ka) and their variations with air-filled porosity (e) in soil is critical for simulating subsurface migration and emission of climate gases and organic vapors. Gas diffusivity and air permeability measurements from Danish soil...... in subsurface soil. The data were regrouped into four categories based on compaction (total porosity F 0.4 m3 m-3) and soil texture (volume-based content of clay, silt, and organic matter 15%). The results suggested that soil compaction more than soil type was the major control on gas...... diffusivity and to some extent also on air permeability. We developed a density-corrected (D-C) Dp(e)/Do model as a generalized form of a previous model for Dp/ Do at -100 cm H2O of matric potential (Dp,100/Do). The D-C model performed well across soil types and density levels compared with existing models...

  8. A falling-pressure method for measuring air permeability of asphalt in laboratory

    Science.gov (United States)

    Li, Hailong; Jiao, Jiu Jimmy; Luk, Mario

    2004-01-01

    This paper presents a simple analytical solution for estimating air permeability using the test data obtained by a falling-pressure method in laboratory. The perimeter of the column-shaped sample is fixed in a steel cylinder with the upper sample surface open to the atmosphere. The lower surface of the sample and the cylinder form an air chamber. A water manometer is connected to the air chamber to measure the air pressure inside after the chamber is pressurized. The data of pressure versus time in the air chamber are recorded and analyzed. An approximate analytical solution is derived to describe the pressure-time relationship in the air chamber. The air permeability can be easily estimated using the approximate analytical solution based on the linear least-squares fitting to the recorded pressure-time test data. This method is used to estimate the falling-pressure test data of 15 asphalt samples. The agreement between the test data and the analytical prediction is satisfactory for all the samples. To investigate the error caused by the approximate analytical solution, the air permeabilities are also estimated based on fully numerical solutions. The permeability values obtained from analytical and numerical solutions are very close. The maximum relative error is less than 6% for samples with more than five pressure-time records. A quantitative condition is given under which the analytical solution applies with negligible estimation error. Compared with the common, steady-state method for measuring air permeability, the falling-pressure method has its advantages such as simplicity and economy. The steady-state method has to measure the air flux through the sample, while the falling-pressure method does not.

  9. 3D printed auxetic forms on knitted fabrics for adjustable permeability and mechanical properties

    Science.gov (United States)

    Grimmelsmann, N.; Meissner, H.; Ehrmann, A.

    2016-07-01

    The 3D printing technology can be applied into manufacturing primary shaping diverse products, from models dealing as examples for future products that will be produced with another technique, to useful objects. Since 3D printing is nowadays significantly slower than other possibilities to manufacture items, such as die casting, it is often used for small parts that are produced in small numbers or for products that cannot be created in another way. Combinations of 3D printing with other objects, adding novel functionalities to them, are thus favourable to a complete primary shaping process. Textile fabrics belong to the objects whose mechanical and other properties can notably be modified by adding 3D printed forms. This article mainly reports on a new possibility to change the permeability of textile fabrics by 3D printing auxetic forms, e.g. for utilising them in textile filters. In addition, auxetic forms 3D printed on knitted fabrics can bring about mechanical properties that are conducive to tensile constructions.

  10. Effects of Ambient Air Particulate Exposure on Blood-Gas Barrier Permeability and Lung Function

    DEFF Research Database (Denmark)

    Bräuner, Elvira Vaclavik; Mortensen, Jann; Møller, Peter

    2009-01-01

    Particulate air pollution is associated with increased risk of pulmonary diseases and detrimental outcomes related to the cardiovascular system, including altered vessel functions. This study's objective was too evaluate the effects of ambient particle exposure on the blood-gas permeability, lung.......5-15.8 microg/m(3) PM(10-2.5)) or filtered (91-542 particles/cm(3)) air collected above a busy street. The clearance rate of aerosolized (99m)Tc-labeled diethylenetriamine pentaacetic acid ((99m)Tc-DTPA) was measured as an index for the alveolar epithelial membrane integrity and permeability of the lung blood...... on the concentration of CC16 in plasma and urine or on the static and dynamic volumes or ventilation distribution of the lungs. The study thus demonstrates increased permeability of the alveolar blood-gas barrier following moderate exercise, whereas exposure to ambient levels of urban air particles has no detectable...

  11. Fabrication of monodisperse hollow silica spheres and effect on water vapor permeability of polyacrylate membrane.

    Science.gov (United States)

    Bao, Yan; Yang, Yongqiang; Ma, Jianzhong

    2013-10-01

    Polystyrene/silica core-shell spheres were fabricated using polystyrene as templates by hydrolysis and condensation of tetraethyl orthosilicate through a sol-gel process, in which polystyrene was synthesized by emulsion polymerization. Then, hollow silica spheres were obtained after selective removal of the organic polystyrene core from the polystyrene/silica core-shell spheres by tetrahydrofuran etching. The effect of hollow silica spheres on water vapor permeability, mechanical property, and water uptake of polyacrylate membrane were investigated. The microstructure analysis shows that the mean size and wall thickness of hollow silica spheres are 170 nm and 20 nm, respectively. The silica shells consist of amorphous silica seed assembly with a broad size distribution, which roughen the surfaces of hollow silica spheres greatly. The specific surface area of hollow silica spheres is bigger than that of polystyrene/silica core-shell spheres. Hollow silica spheres can significantly improve water vapor permeability of polyacrylate membrane, but lead to the reduction in mechanical property.

  12. Air flow paths and porosity/permeability change in a saturated zone during in situ air sparging.

    Science.gov (United States)

    Tsai, Yih-Jin

    2007-04-01

    This study develops methods to estimate the change in soil characteristics and associated air flow paths in a saturated zone during in situ air sparging. These objectives were achieved by performing combined in situ air sparging and tracer testing, and comparing the breakthrough curves obtained from the tracer gas with those obtained by a numerical simulation model that incorporates a predicted change in porosity that is proportional to the air saturation. The results reveal that revising the porosity and permeability according to the distribution of gas saturation is helpful in breakthrough curve fitting, however, these changes are unable to account for the effects of preferential air flow paths, especially in the zone closest to the points of air injection. It is not known the extent to which these preferential air flow paths were already present versus created, increased, or reduced as a result of the air sparging experiment. The transport of particles from around the sparging well could account for the overall increase in porosity and permeability observed in the study. Collection of soil particles in a monitoring well within 2m of the sparging well provided further evidence of the transport of particles. Transport of particles from near the sparging well also appeared to decrease the radius of influence (ROI). Methods for predicting the effects of pressurized air injection and water flow on the creation or modification of preferential air flow paths are still needed to provide a full description of the change in soil conditions that accompany air sparging.

  13. Graphene oxide membranes with high permeability and selectivity for dehumidification of air

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Yongsoon; Liu, Wei; Schwenzer, Birgit; Manandhar, Sandeep; Chase-Woods, Dylan G.; Engelhard, Mark H.; Devanathan, Ram; Fifield, Leonard S.; Bennett, Wendy D.; Ginovska-Pangovska, Bojana; Gotthold, David W.

    2016-09-01

    Hierarchically stacked 2D graphene oxide (GO) membranes are a fascinating and promising new class of materials with the potential for radically improved water vapor/gas separation with excellent selectivity and high permeability. This paper details dehumidification results from flowing gas mixtures through free-standing GO membrane samples prepared by a casting method. The first demonstrated use of free-standing GO membranes for water vapor separation reveals outstanding water vapor permeability and H2O/N2 selectivity. Free-standing GO membranes exhibit extremely high water vapor permeability of 1.82 x 105 Barrer and a water vapor permeance of 1.01 x 10-5 mol/m2sPa, while the nitrogen permeability was below the system’s detection limit, yielding a selectivity >104 in 80% relative humidity (RH) air at 30.8 °C. The results show great potential for a range of energy conversion and environmental applications

  14. Effects of air-drying in vitro on human dentine permeability.

    Science.gov (United States)

    Pashley, D H; Stewart, F P; Galloway, S E

    1984-01-01

    The effects of evaporation produced by air blasts of 0, 0.5, 2 or 5 min to dentine in vitro were evaluated by measuring dentine hydraulic conductance before and after each trial. When the tubules were filled with water, even prolonged evaporation had no effect on dentine permeability. Tubules filled with physiological salt solution produced a time-dependent decrease in dentine permeability. Tubules filled with 1.5 per cent albumin in water gave the largest reductions in dentine permeability. These effects were more marked in unetched as opposed to acid-etched dentine. The results suggest that part of the reduction in dentine sensitivity produced clinically by prolonged air blasts may be due to precipitation of organic and inorganic constituents of dentinal fluid at the surface.

  15. Estimating saturated hydraulic conductivity and air permeability from soil physical properties using state-space analysis

    DEFF Research Database (Denmark)

    Poulsen, Tjalfe; Møldrup, Per; Nielsen, Don

    2003-01-01

    field were used. Multiple regression and ARIMA models yielded similar prediction accuracy, whereas state-space models generally gave significantly higher accuracy. State-space modeling suggested K-S at a given location could be predicted using nearby values of K-S, k(a100) and air-filled porosity......Estimates of soil hydraulic conductivity (K) and air permeability (k(a)) at given soil-water potentials are often used as reference points in constitutive models for K and k(a) as functions of moisture content and are, therefore, a prerequisite for predicting migration of water, air, and dissolved...... and gaseous chemicals in the vadose zone. In this study, three modeling approaches were used to identify the dependence of saturated hydraulic conductivity (K-S) and air permeability at -100 cm H2O soil-water potential (k(a100)) on soil physical properties in undisturbed soil: (i) Multiple regression, (ii...

  16. Field test to study the pressure equilization on air permeable facade elements

    NARCIS (Netherlands)

    Bentum, C.A. van; Kalkman, I.M.; Geurts, C.P.W.

    2014-01-01

    The net wind load on the outer layer of a façade consisting of multiple layers is determined by the external pressure and the cavity pressure. For an air-permeable outer layer, the cavity pressure is dependent on the extent to which the external pressure equalizes over the openings. Minimizing the p

  17. Leak-Based Method for the Measurement of Air Permeability of Papers

    Directory of Open Access Journals (Sweden)

    Colard Stéphane

    2016-01-01

    Full Text Available The air permeability of cigarette paper is currently assessed according to the international standard ISO 2965 by applying a constant pressure difference of 1 kPa between the two faces of a sample and by measuring the corresponding airflow.

  18. Density-corrected models for gas diffusivity and air permeability in unsaturated soil

    DEFF Research Database (Denmark)

    Deepagoda Thuduwe Kankanamge Kelum, Chamindu; Møldrup, Per; Schjønning, Per

    2011-01-01

    . Also, a power-law ka model with exponent 1.5 (derived from analogy with a previous gas diffusivity model) used in combination with the D-C approach for ka,100 (reference point) seemed promising for ka(e) predictions, with good accuracy and minimum parameter requirements. Finally, the new D-C model......Accurate prediction of gas diffusivity (Dp/Do) and air permeability (ka) and their variations with air-filled porosity (e) in soil is critical for simulating subsurface migration and emission of climate gases and organic vapors. Gas diffusivity and air permeability measurements from Danish soil...... profile data (total of 150 undisturbed soil samples) were used to investigate soil type and density effects on the gas transport parameters and for model development. The measurements were within a given range of matric potentials (-10 to -500 cm H2O) typically representing natural field conditions...

  19. Versatile fabrication of nanocomposite microcapsules with controlled shell thickness and low permeability.

    Science.gov (United States)

    Yang, Yu; Wei, Zengjiang; Wang, Chaoyang; Tong, Zhen

    2013-04-10

    Novel ethyl phenylacetate (EPA)-loaded nanocomposite microcapsules with polyurea (PU) /poly (melamine formaldehyde) (PMF) shells were facilely and fabricated: by using silica nanoparticle-stabilized oil-in-water (o/w) emulsion template and subsequent interfacial reaction and in situ polymerization. SiO2 nanoparticles absorbed at the interface between oil and water to stabilize the o/w emulsions. The oil droplets containing EPA, isophorone diisocyanate (IPDI) and tolylene 2,4-diisocyanate-terminated poly (propylene glycol) (PPG-TDI) were subsequently reacted with MF prepolymer (pre-MF) dissolved in water phases. The interfacial reaction between pre-MF and IPDI produced interior PU walls. Meanwhile, the in situ polymerization of pre-MF generated exterior PMF walls. It was found that these in/out double walls were compact together. The resulting capsules had spherical shapes and rough exterior surfaces, and could be easily isolated, dried, and redispersed in epoxy resins. The size of the produced microcapsules was dependent on the concentration of SiO2 nanoparticles. The dynamic thermal gravimetric analysis (TGA) demonstrated that the capsules showed excellent thermal stability with little weight loss when exposed at 150 °C for 2 h. Interestingly, with a double PU/PMF shell, these capsules exhibited an extra-low permeability. Moreover, these microcapsules can also demonstrate exceelent magnetic responsiveness after introducing magnetic nanoparticles inside. We believe our microcapsules could be potential candidates in microcapsule engineering, self-healing composites, and drug-carrying systems.

  20. Technology & Mechanics Overview of Air-Inflated Fabric Structures

    Science.gov (United States)

    2006-12-04

    bridging, and energy absorbers such as automotive air bags and landing cushions for space vehicles. Recent advances in high performance fibers and...inflated fabric structures were constructed using adhesively bonded, piece-cut manufacturing methods. These methods were limited to relatively low...moisture, fire, chemicals, etc. Coating materials such as urethane , PVC (poly vinyl chloride), neoprene, EPDM (ethylene propylene diene monomer) are

  1. Design AND Fabrication OF Homemade Air Conditioner

    Directory of Open Access Journals (Sweden)

    Naikodi Mallappa,

    2014-04-01

    Full Text Available Human always tries for better comfort and sophistication at each level of his life. Considering air conditioning, evaporative cooler are used in less humidity and dry climate. The limitation of evaporative cooler is that it is not suitable in humid environment and also their performance is poor in the places where ventilation is not proper. The objective of this project is to increase the effectiveness of the ordinary table fan by using simple mechanism and overcome the limitation of evaporative cooler. In this project the table fan is wound with copper tube by copper wire. Vinyl tube is connected with one end of the copper tube and another end of vinyl tube is connected with pump. Pump immersed in the cooling chamber. Vinyl tube is connected with another end of copper tube another end of vinyl tube is immersed in the cooling chamber. Fan and pump connected with electricity pump and is sucks the cool water from the cooling chamber.

  2. Using soft computing techniques to predict corrected air permeability using Thomeer parameters, air porosity and grain density

    Science.gov (United States)

    Nooruddin, Hasan A.; Anifowose, Fatai; Abdulraheem, Abdulazeez

    2014-03-01

    Soft computing techniques are recently becoming very popular in the oil industry. A number of computational intelligence-based predictive methods have been widely applied in the industry with high prediction capabilities. Some of the popular methods include feed-forward neural networks, radial basis function network, generalized regression neural network, functional networks, support vector regression and adaptive network fuzzy inference system. A comparative study among most popular soft computing techniques is presented using a large dataset published in literature describing multimodal pore systems in the Arab D formation. The inputs to the models are air porosity, grain density, and Thomeer parameters obtained using mercury injection capillary pressure profiles. Corrected air permeability is the target variable. Applying developed permeability models in recent reservoir characterization workflow ensures consistency between micro and macro scale information represented mainly by Thomeer parameters and absolute permeability. The dataset was divided into two parts with 80% of data used for training and 20% for testing. The target permeability variable was transformed to the logarithmic scale as a pre-processing step and to show better correlations with the input variables. Statistical and graphical analysis of the results including permeability cross-plots and detailed error measures were created. In general, the comparative study showed very close results among the developed models. The feed-forward neural network permeability model showed the lowest average relative error, average absolute relative error, standard deviations of error and root means squares making it the best model for such problems. Adaptive network fuzzy inference system also showed very good results.

  3. Results of air-permeability testing in a vertical borehole at Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    LeCain, G.D. [Geological Survey, Denver, CO (United States); Walker, J.N. [Geological Survey, Mercury, NV (United States)

    1994-12-31

    Air-injection testing to determine air permeabilities was conducted in borehole UE-25 UZ No.16 as part of the Yucca Mountain Surface-Based Borehole Investigations Project. Air permeabilities of the rocks tested are: (1) Tiva Canyon Member; 2.0 E-13 m{sup 2} to 88.0 E-13 m{sup 2}; (2) Topopah Spring Member; 1.1 E-13 m{sup 2} to 12.0 E-13 m{sup 2}. Based on the moisture observed on the downhole equipment, the borehole wall is dry down to 268.3 meters below surface level and wet below this depth. Testing above 268.3 meters showed no wellbore storage or skin effects. Tests conducted below 268.3 meters showed both wellbore storage and skin effects. Tests that forced water out of the rock exhibited a characteristic pressure drop in the arithmetic pressure plots. The stabilization pressure of the steady-state testing following this pressure drop provides an estimate of the test interval in-situ capillary pressure. Permeabilities calculated from the steady-state period following the pressure drop were less than those calculated from the transient tests, because the steady-state analysis did not account for skin effects.

  4. Fabrication of Fe-based ribbon with controlled permeability by Joule heating under tensile stress

    Energy Technology Data Exchange (ETDEWEB)

    Yanai, T. [Department of Electrical and Electronic Engineering, Faculty of Engineering of the University of Nagasaki, Nagasaki 852-8521 (Japan)], E-mail: t-yanai@nagasaki-u.ac.jp; Takagi, K.; Takahashi, K.; Nakano, M. [Department of Electrical and Electronic Engineering, Faculty of Engineering of the University of Nagasaki, Nagasaki 852-8521 (Japan); Yoshizawa, Y. [Advanced Electronics Research Laboratory, Hitachi Metals Ltd., Kumagaya 360-0843 (Japan); Fukunaga, H. [Department of Electrical and Electronic Engineering, Faculty of Engineering of the University of Nagasaki, Nagasaki 852-8521 (Japan)

    2008-10-15

    We prepared an Fe-based ribbon with controlled permeability and low magnetic loss by continuous stress-annealing by joule heating (CSA-JH) method. The shortest annealing time necessary for the obtaining of the ribbons with completely developed anisotropy was 1 s, but in order to obtain the sufficiently crystallized ribbons with small saturation magnetostriction it is required to perform annealing longer than 2 s. A toroidal core was prepared from a long ribbon with controlled permeability and small saturation magnetostriction, and the magnetic loss and relative permeability of the core were evaluated in the frequency range of 0.1-3 MHz. The permeability was kept constant up to 2 MHz, and the magnetic loss is lower than that for other types of core with a similar permeability value. These results suggest that the CSA-JH method is a promising method for realizing an Fe-based core with excellent magnetic properties.

  5. Performance evaluation of PAN nanofiber air filter fabricated by electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung Cheol; Kim, Tae Eun; Lee, Jung Koo; Ahn, Ji Woong; Park, Sung Ho; Kim, Hyung Man [Dept. of Electronic, Telecommunications, Mechanical and Automotive Engineering, Inje University, Kimhae (Korea, Republic of)

    2015-11-15

    Nanomaterials possess unique mechanical, physical, and chemical properties. They are small, and have an ultrahigh surface area, making them suitable for air filter applications. Electrospinning has been recognized as an efficient technique for fabricating polymer nanofibers. In order to determine the optimum manufacturing conditions, the effects of several electrospinning process parameters on the diameter, orientation, and distribution of polyacrylonitrile (PAN) nanofiber are analyzed. To improve interlaminar fracture toughness and suppress delamination in the form of laminated non-woven fibers by using a heat roller, the performances of filter efficiency and pressure drop achieved with PAN nanofiber air filter are evaluated experimentally.

  6. Design, Fabrication and Testing Of Flapping Wing Micro Air Vehicle

    Directory of Open Access Journals (Sweden)

    K. P. Preethi Manohari Sai

    2016-01-01

    Full Text Available Flapping flight has the potential to revolutionize micro air vehicles (MAVs due to increased aerodynamic performance, improved maneuverability and hover capabilities. The purpose of this project is to design and fabrication of flapping wing micro air vehicle. The designed MAV will have a wing span of 40cm. The drive mechanism will be a gear mechanism to drive the flapping wing MAV, along with one actuator. Initially, a preliminary design of flapping wing MAV is drawn and necessary calculation for the lift calculation has been done. Later a CAD model is drawn in CATIA V5 software. Finally we tested by Flying.

  7. Relation of transverse air permeability with physical properties in different compositions of sugarcane bagasse particleboards

    Directory of Open Access Journals (Sweden)

    Lina Bufalino

    2013-02-01

    Full Text Available Studies concerning the production of particleboards with sugarcane bagasse as an alternative fibrous material have been carried out as an attempt to provide a sustainable and viable destination for this residue. This work aimed to evaluate the influence of several processing variables related to the microstructure of sugarcane bagasse particleboards (mat type, adhesive type and adhesive content on their permeability and water sorption properties. Air permeability data was collected by the rotameter method. Superficial air permeability (kg, Darcian constant (k1 and non-Darcian constant (k2 were measured. kg was related to sorption behavior of the particleboards. 1-layer particleboards presented significantly higher kg values than the 3-layer particleboards. In general, adhesive type, position and content did not influence kg of particleboards. However, these processing variables influenced interactions between fluid and material and tortuosity of the porous media. Particleboards produced with urea-formaldehyde with high kg presented higher water absorption and thickness swelling after 24 hours. Such relations were not observed in particleboards produced with melamine-urea-formaldehyde.

  8. The Influence of Antimicrobial Treatment on Air Permeability and Water Absorption of Knits

    Directory of Open Access Journals (Sweden)

    Agne Mickeviciene

    2015-03-01

    Full Text Available Antimicrobialfinishing is increasingly used for various purposes in textile products.Therefore, it is important to determine whether the antimicrobial finishchanging comfort properties (air permeability, water absorption, etc. ofknits. The objective of this research was to establish the influence ofantimicrobial treatment conditions on air permeability and water absorptionproperties of plain plated knits. The investigations were carried out with threegroups of single plain plated knits. The ground and plating yarns of I group ofknits is pure fiber cotton, man-made bamboo, polyester. The ground yarns of IIand III groups of knits are accordingly polyamide and elastane threads. Theplating yarns in mentioned groups are the same as in I group – cotton, man-madebamboo, polyester yarns. Part of the knits of all groups were treated in anantimicrobial solution of iSys AG and organic-inorganic binder iSys MTX (CHT,Germany as well as the other part of the knits were treated in the sameconditions as treated in antimicrobial solution, however, an antimicrobialmaterial and binder weren’t used.Itwas established that air permeability of investigated knits changedinsignificant regardless of whether reagents providing an antimicrobial effectwere used or not used in finishing process. This means that the chemicalsubstance used for antimicrobial finishing do not worsens an air permeabilityof knits. Meanwhile, the water absorption of antimicrobial treated knits wassignificantly lower than of blank treated knits because the organic-inorganicbinder, used in antimicrobial treatment, forms the sol-gel layer on the surfaceof fiber.DOI: http://dx.doi.org/10.5755/j01.ms.21.1.5503

  9. Permeability of Electrospun Superhydrophobic Nanofiber Mats

    Directory of Open Access Journals (Sweden)

    Sarfaraz U. Patel

    2012-01-01

    Full Text Available This paper discusses the fabrication and characterization of electrospun nanofiber mats made up of poly(4-methyl-1-pentene polymer. The polymer was electrospun in different weight concentrations. The mats were characterized by their basis weight, fiber diameter distribution, contact angles, contact angle hysteresis, and air permeability. All of the electrospun nonwoven fiber mats had water contact angles greater than 150 degrees making them superhydrophobic. The permeabilities of the mats were empirically fitted to the mat basis weight by a linear relation. The experimentally measured air permeabilities were significantly larger than the permeabilities predicted by the Kuwabara model for fibrous media.

  10. Fabrication of nanofiber non-wovens on the melt blowing die with air by-passes

    OpenAIRE

    Chen Ting; Yang Kang; Wu Li-Li

    2016-01-01

    The air flow field of the melt blowing die with air by-passes is simulated. The results show that fibers fabricated on the die with air by-passes are much finer than those without air by-passes, which indicates an energy-saving approach to fabricating nanofibers on the melt blowing equipment.

  11. Fabrication of nanofiber non-wovens on the melt blowing die with air by-passes

    Directory of Open Access Journals (Sweden)

    Chen Ting

    2016-01-01

    Full Text Available The air flow field of the melt blowing die with air by-passes is simulated. The results show that fibers fabricated on the die with air by-passes are much finer than those without air by-passes, which indicates an energy-saving approach to fabricating nanofibers on the melt blowing equipment.

  12. Fabrication and application of a wireless inductance-capacitance coupling microsensor with electroplated high permeability material NiFe

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y H; Chang, I N [Ph. D. Program in Electrical and Communications Engineering, Feng-Chia University, Taichung 40724, Taiwan (China); Chang, H C; Lai, C C, E-mail: hcchang@fcu.edu.tw [Department of Automatic Control Engineering, Feng-Chia University, Taichung 40724, Taiwan (China)

    2011-01-01

    A fully integrated wireless inductance-capacitance (LC) coupling microsensor was designed and fabricated by MEMS technology. The sensing loop was formed by connecting a deformable parallel-plated capacitor and a planar spiral inductor with a Ni(80)Fe(20) core. Polyimide and PMMA were used to isolate and package the devices. Typical dimension of the sensors was 5 x 5 mm{sup 2} x 0.77 mm. Different electroplated inductive coils (30, 40, and 60 turns) were fabricated to connect with a 4 x 4 mm{sup 2} plate capacitor in series. The LC sensing module for measuring liquid-level induced frequency responses was setup. Experimental results show that frequency response decreased as liquid level increased and sensitivity is about 7.01 kHz/cm with deviation less than 2%. Developed planar spiral inductor with high permeability magnetic core can provide a wide range of frequency variation in LC sensing applications.

  13. Gas diffusion, non-darcy air permeability and CT-scans for a traffic-affected clay subsoil

    DEFF Research Database (Denmark)

    Lamandé, Mathieu; Schjønning, Per; Berisso, Feto Esimo

    2013-01-01

    The objective of this study was to evaluate the long-term effect of compaction on the pore system at 0.5 m depth of a heavy clay soil in Jokioinen, Finland. Gas diffusion and air permeability measurements were combined with pycnometer-estimated air-filled pore volumes. We wanted to evaluate, to w...

  14. Hot air injection for removal of dense, non-aqueous-phase liquid contaminants from low-permeability soils

    Energy Technology Data Exchange (ETDEWEB)

    Payne, F.C.

    1996-08-01

    The performance of soil vapor extraction systems for the recovery of volatile and semi-volatile organic compounds is potentially enhanced by the injection of heated air to increase soil temperatures. The soil temperature increase is expected to improve soil vapor extraction (SVE) performance by increasing target compound vapor pressures and by increasing soil permeability through drying. The vapor pressure increase due to temperature rise relieves the vapor pressure limit on the feasibility of soil vapor extraction. However, the system still requires an air flow through the soil system to deliver heat and to recover mobilized contaminants. Although the soil permeability can be increased through drying, very low permeability soils and low permeability soils adjacent to high permeability air flow pathways will be treated slowly, if at all. AR thermal enhancement methods face this limitation. Heated air injection offers advantages relative to other thermal techniques, including low capital and operation costs. Heated air injection is at a disadvantage relative to other thermal techniques due to the low heat capacity of air. To be effective, heated air injection requires that higher air flows be established than for steam injection or radio frequency heating. Heated air injection is not economically feasible for the stratified soil system developed as a standard test for this document. This is due to the inability to restrict heated air flow to the clay stratum when a low-resistance air flow pathway is available in the adjoining sand. However, the technology should be especially attractive, both technically and economically, for low-volatile contaminant recovery from relatively homogeneous soil formations. 16 refs., 2 tabs.

  15. Experimental Study of the Feasibility of Air Flooding in an Ultra-Low Permeability Reservoir

    Directory of Open Access Journals (Sweden)

    Guohui Qu

    2016-09-01

    Full Text Available The development effect of water flooding in an ultra-low permeability reservoir is poor due to its poor physical properties and high shale content, so an experimental study of air flooding which helps to complement energy production was carried out. Based on the Accelerating Rate Calorimeter experimental results, the crude oil of N block in L oilfield can undergo low-temperature oxidation reactions, which are the basic condition for air flooding. Three groups of experimental natural cylinder cores designed for oil displacement, water flooding and air flooding were used respectively, and the relationship between differential pressure, oil recovery, injection capacity with injection volume was investigated. It is observed that the recovery efficiency increased 2.58%, the injection-production pressure difference dropped 60% and the injection capability increased 60% in the experiment of shifting air flooding after water flooding to 75% moisture content, compared with water flooding alone. It has been shown in the results that the recovery efficiency improved sharply more than water flooding, the effect of depressurization and augmented injection was obvious, and the air displacement was thus validated. We suggest that other science and technology workers should perform further tests and verify this result through numerical simulation.

  16. Evaluating the relative air permeability of porous media from their water retention curves

    Science.gov (United States)

    Assouline, S.; Tuli, A.; Hopmans, J. W.

    2016-05-01

    Accurate modeling of water and air flow in porous media requires the definition of the relevant hydraulic properties, namely, the water retention curve (WRC) and the relative hydraulic conductivity function (RHC), as well as the definition of the relative air permeability function (RAP). Capitalizing on the approach developed previously to represent the RHC, a new model allowing the prediction of RAP based on information resulting from the WRC is proposed. The power value ηa in the model is a decreasing exponential function of the coefficient of variation, ɛ, characterizing the pore size distribution of the porous medium, and derived from its WRC. The model was calibrated using data from 22 disturbed and undisturbed soil samples and was validated using data from eight soil types ranging from quartz sand to silty clay loam. The proposed model provided accurate prediction of the soil RAP and performed in some cases (sandy loam and silty clay loam soils) better than available alternative models.

  17. Modeling Air Permeability in Variably Saturated Soil from Two Natural Clay Gradients

    DEFF Research Database (Denmark)

    Chamindu, Deepagoda T K K; Arthur, Emmanuel; Møldrup, Per

    2013-01-01

    Understanding soil–gas phase properties and processes is important for finding solutions to critical environmental problems such as greenhouse gas emissions and transport of gaseous-phase contaminants in soils. Soil–air permeability, ka (μm2), is the key parameter governing advective gas movement...... in soil and is controlled by soil physical characteristics representing soil texture and structure. Models predicting ka as a function of air-filled porosity (ɛ) often use a reference-point measurement, for example, ka,1000 at ɛ1000 (where the measurement is done at a suction of –1000 cm H2O). Using ka...... measurements from two Danish arable fields, each located on natural clay gradients, this study presents a pore tortuosity–disconnectivity analysis to characterize the soil–gas phase. The main objective of this study is to investigate the effect of soil–moisture condition, clay content, and other potential...

  18. Fabrication Methods and Performance of Low-Permeability Microfluidic Components for a Miniaturized Wearable Drug Delivery System.

    Science.gov (United States)

    Mescher, Mark J; Swan, Erin E Leary; Fiering, Jason; Holmboe, Maria E; Sewell, William F; Kujawa, Sharon G; McKenna, Michael J; Borenstein, Jeffrey T

    2009-06-01

    In this paper, we describe low-permeability components of a microfluidic drug delivery system fabricated with versatile micromilling and lamination techniques. The fabrication process uses laminate sheets which are machined using XY milling tables commonly used in the printed-circuit industry. This adaptable platform for polymer microfluidics readily accommodates integration with silicon-based sensors, printed-circuit, and surface-mount technologies. We have used these methods to build components used in a wearable liquid-drug delivery system for in vivo studies. The design, fabrication, and performance of membrane-based fluidic capacitors and manual screw valves provide detailed examples of the capability and limitations of the fabrication method. We demonstrate fluidic capacitances ranging from 0.015 to 0.15 μL/kPa, screw valves with on/off flow ratios greater than 38 000, and a 45× reduction in the aqueous fluid loss rate to the ambient due to permeation through a silicone diaphragm layer.

  19. Design and fabrication of a micro zinc/air battery

    Science.gov (United States)

    Fu, L.; Luo, J. K.; Huber, J. E.; Lu, T. J.

    2006-04-01

    Micro-batteries are one of the key components that restrict the application of autonomous Microsystems. However little efforts were made to solve the problem. We have proposed a new planar zinc/air micro-battery, suitable for autonomous microsystem applications. The micro-battery has a layered structure of zinc electrode/alkaline electrolyte/air cathode. A 3D zinc electrode with a high density of posts was designed to obtain a high porosity, hence to offer a best performance. A model of the micro-battery is developed and the device performances were simulated and discussed. A four-mask process was developed to fabricate the prototype micro-batteries. The preliminary testing results showed the micro-batteries is able to deliver a maximum power up to 5 mW, and with an average power of 100 µW at a steady period for up to 2hrs. Fabrication process is still under optimization for further improvement.

  20. The Effects of Air Permeability, Background Ventilation and Lifestyle on Energy Performance, Indoor Air Quality and Risk of Condensation in Domestic Buildings

    Directory of Open Access Journals (Sweden)

    Arman Hashemi

    2015-04-01

    Full Text Available Effective and efficient ventilation is essential when improving energy performance and Indoor Air Quality (IAQ of buildings. Reducing air permeability can considerably improve the energy performance of buildings; however, making the buildings more airtight may result in lower rates of natural ventilation which may in turn increase the risks of condensation and unacceptable IAQ. This study evaluates the effects of different air permeability rates, background ventilation and occupants’ lifestyles on the energy performance as well as the risk of condensation and CO2 concentration in domestic buildings. Dynamic computer simulations were conducted in EnergyPlus. Results indicated direct relations between the ventilation rates, energy performance and IAQ. Higher air permeability along with background ventilation resulted in considerably better IAQ while energy consumption increased by up to four times. Occupants’ lifestyles were identified as a major contributor to the risk of condensation.

  1. 织物湿传导理论与实际的研究第二报:织物湿传导理论方程的研究%The research on the theory and practice of wet permeability of fabrics Ⅱ: Theoretical equations of wet permeability of fabrics

    Institute of Scientific and Technical Information of China (English)

    姚穆; 施楣梧

    2001-01-01

    Wet permeability in fabrics have many links:diffusion of wate r vapour in air,vaporization of water vapeur on water surface,condensa tion of water vapour in capillary ,vaporization of water vapour in copillary and water transfer in capillary etc.The theoretical equations of theses states are discussed in this paper .%研究了织物透湿过程中涉及的水蒸汽在湿空气中的扩散,水平液面上水蒸汽的蒸发,在毛细管中水蒸汽的凝结,毛细管中水蒸汽的蒸发和毛细管中液态水的输送等过程的状态和理论方程.

  2. Use of novel permeable membrane and air cathodes in acetate microbial fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Pant, Deepak, E-mail: deepak.pant@vito.b [Separation and Conversion Technology, VITO - Flemish Institute for Technological Research, Boeretang 200, Mol 2400 (Belgium); Van Bogaert, Gilbert; De Smet, Mark; Diels, Ludo; Vanbroekhoven, Karolien [Separation and Conversion Technology, VITO - Flemish Institute for Technological Research, Boeretang 200, Mol 2400 (Belgium)

    2010-11-01

    In the existing microbial fuel cells (MFCs), the use of platinized electrodes and Nafion as proton exchange membrane (PEM) leads to high costs leading to a burden for wastewater treatment. In the present study, two different novel electrode materials are reported which can replace conventional platinized electrodes and can be used as very efficient oxygen reducing cathodes. Further, a novel membrane which can be used as an ion permeable membrane (Zirfon) can replace Nafion as the membrane of choice in MFCs. The above mentioned gas porous electrodes were first tested in an electrochemical half cell configuration for their ability to reduce oxygen and later in a full MFC set up. It was observed that these non-platinized air electrodes perform very well in the presence of acetate under MFC conditions (pH 7, room temperature) for oxygen reduction. Current densities of -0.43 mA cm{sup -2} for a non-platinized graphite electrode and -0.6 mA cm{sup -2} for a non-platinized activated charcoal electrode at -200 mV vs. Ag/AgCl of applied potential were obtained. The proposed ion permeable membrane, Zirfonwas tested for its oxygen mass transfer coefficient, K{sub 0} which was compared with Nafion. The K{sub 0} for Zirfon was calculated as 1.9 x 10{sup -3} cm s{sup -1}.

  3. Two-Region Extended Archie's Law Model for Soil Air Permeability and Gas Diffusivity

    DEFF Research Database (Denmark)

    Hamamoto, Shoichiro; Møldrup, Per; Kawamoto, Ken

    2011-01-01

    The air permeability (ka) and soil gas diffusion coefficients (Dp) are controlling factors for gas transport and fate in variably saturated soils. We developed a unified model for ka and Dp based on the classical Archie's law, extended by: (i) allowing for two-region gas transport behavior...... for structured soils, with the natural field moisture condition (set at −100 cm H2O matric potential [pF 2]) as the reference (spliced) point between the large-pore (drained pore diameter ≥30 μm at pF ≤ 2) and the small-pore (subsequently drained pores 2) regions, and (ii) including a percolation...... threshold, set as 10% of the total porosity for structureless porous media or 10% of the porosity in the large-pore region for structured soils. The resulting extended Archie's law with reference point (EXAR) models for ka and Dp were fitted to the measured data. For both structureless and structured porous...

  4. Semi-permeable coatings fabricated from comb-polymers efficiently protect proteins in vivo

    Science.gov (United States)

    Liu, Mi; Johansen, Pål; Zabel, Franziska; Leroux, Jean-Christophe; Gauthier, Marc A.

    2014-11-01

    In comparison to neutral linear polymers, functional and architecturally complex (that is, non-linear) polymers offer distinct opportunities for enhancing the properties and performance of therapeutic proteins. However, understanding how to harness these parameters is challenging, and studies that capitalize on them in vivo are scarce. Here we present an in vivo demonstration that modification of a protein with a polymer of appropriate architecture can impart low immunogenicity, with a commensurably low loss of therapeutic activity. These combined properties are inaccessible by conventional strategies using linear polymers. For the model protein L-asparaginase, a comb-polymer bio-conjugate significantly outperformed the linear polymer control in terms of lower immune response and more sustained bioactivity. The semi-permeability characteristics of the coatings are consistent with the phase diagram of the polymer, which will facilitate the application of this strategy to other proteins and with other therapeutic models.

  5. Reducing compaction effort and incorporating air permeability in Proctor testing for design of urban green spaces on cohesive soils

    Science.gov (United States)

    It is well established that compaction negatively affects agronomic productivity, that air permeability is a sensitive measure of the degree of soil compaction and therefore a good indicator of soil productivity impairment from compaction. Cohesive soils in urban settings are often heavily compacted...

  6. The Structure Characteristics and Air Permeability of PA and PES Plain and Plated Knits Influenced of Antimicrobial Treatment Conditions

    Directory of Open Access Journals (Sweden)

    Agne MICKEVIČIENĖ

    2014-09-01

    Full Text Available Textile materials are usually exposed to thermal, physical and mechanical effects during treatment processes. These influence the changes of material dimensions. Designing knitted products it is important to predict direction and rate of dimensions change, because this can affect physical properties such as air permeability of knits. The objective of this research was to investigate the influence of antimicrobial treatment conditions on the structure characteristics, thickness and air permeability of plain and plaited knits. The investigations were carried out with two groups of plain and plated single jersey knits. The face yarns of these groups were cotton, bamboo viscose yarn and polyester (Dacron® thread. 10 tex × 2 textured polyamide (PA and 20 tex textured polyester (PES threads were used as the base threads in plated knits. Knitted samples were treated with antimicrobial material Isys AG and organic-inorganic binder Isys MTX (CHT, Germany. It was established that blank and antimicrobial treated knits changed structure parameters, thickness and air permeability. The changes of structure parameters, thickness and air permeability were more associated with conditions of treatment (temperature, treatment in solution, mechanical action rather than with antimicrobial and sol-gel substances used in treatment. DOI: http://dx.doi.org/10.5755/j01.ms.20.3.3196

  7. Fabrication of semi-aromatic polyamide/spherical mesoporous silica nanocomposite reverse osmosis membrane with superior permeability

    Science.gov (United States)

    Li, Qiang; Yu, Hui; Wu, Feiyang; Song, Jie; Pan, Xianhui; Zhang, Meng

    2016-02-01

    Semi-aromatic polyamide (SAP)/spherical mesoporous silica nanocomposite reverse osmosis (RO) membrane was successfully fabricated using m-phenylene diamine aqueous solution and cyclohexane-1,3,5-tricarbonyl chloride/mesoporous-silica-sphere (MSS) organic solution as main raw materials. The experimental suggests that the microstructures and surface features are significantly different from those of the contrast samples (the full- and semi-aromatic polyamide membranes), including the surface morphology, polymer framework structure, surface charge density, hydrophilicity, and the thickness of barrier layer. It was observed that many MSSs with ca. 1.5 nm of pore size are evenly embedded on the surface of the fabricated SAP/MSS RO membrane. Furthermore, the separation performance testing results indicate that the permeabilities range from 62.53 to 72.73 L/m2 h with the increase of the introduced MSSs from 0.02 to 0.08 w/v % under 1.5 MPa operating pressure and 2000 mg/L NaCl solution, which is obviously better than the contrast samples. Simultaneously, their salt rejections can be still maintained at a comparable level (94.78-91.46%). The excellent separation performance of the nanocomposite RO membrane is closely related to the higher-freedom-degree semi-aromatic framework, the incorporation of MSSs, the improved surface hydrophilicity, the thinner barrier layer, and the enhanced surface negative charge density.

  8. The Analyze of Soil air Permeability Daily Change Characteristics%土壤导气率日变化特征分析

    Institute of Scientific and Technical Information of China (English)

    王卫华; 王全九

    2011-01-01

    In this paper, under no rain, no irrigation conditions that the soil moisture content at a low level, almost no change, in that can be neglected on the rate of soil air permeability, the relationship between soil air permeability and temperature was studied. Using PL - 300 soil air permeability measurement, measured the soil surface air permeability of corn and apple land and under ground 5 cm air permeability for daily observation. At the same time, measured the local air temperature, surface temperature, and under ground 5cm temperature. Through the field experiment on soil air permeability of the day tracking, analyzing the diurnal variation of air permeability, the results were follows: air permeability of corn land changed with surface temperature, air permeability of corn and apple land measured has the liner relationship with air temperature. In this paper, we establish the predicted relationship between soil air permeability of and temperatures provide a reference value for the local soil permeability measurements.%土壤含水率处于较低水平时,可以忽略其对地表导气率的影响,单一研究温度与导气率之间的关系。针对陕西长武地区玉米地、果树地的土壤表层导气率、地表下5cm导气率进行全天跟踪测量,同时监测地温、气温,从而分析导气率日变化特征。结果表明,玉米地地表导气率随温度的变化而变化,玉米地和果树地表层导气率与气温存在显著线性关系,建立了当地通过地温预测导气率的关系式,为当地土壤导气率的测量提供参考值。

  9. Air Dispersion Characteristics and Thermal Comparison of Traditional and Fabric Ductwork using Computational Fluid Dynamics

    Science.gov (United States)

    Andreopoulou, Areti

    This thesis research compares the air dispersion and thermal comfort characteristics of conventional diffuser and fabric-based ductwork systems. Heating, ventilation, and air-conditioning (HVAC) systems in buildings produce and regulate airflow traveling through ductwork. The performance characteristics of conventional ductwork are compared with recent advancements in fabric-based ductwork. Using computational fluid dynamics (CFD) analysis, thermal and air distribution flow patterns are compared between the two types of ductwork and preliminary thermal comfort and efficiency conclusions are drawn. Results of the Air Distribution Performance Index (ADPI) for both ducting systems reflect that, under the given test conditions, the fabric duct system is approximately 23% more comfortable than the traditional diffuser system in terms of air speed flow uniformity into the space, while staying within the Effective Draft Temperature comfort zone of -3 to +2°F.

  10. Fabrication and Hydrogen Permeability of Palladium Membranes%钯膜制备及渗氢性能研究∗

    Institute of Scientific and Technical Information of China (English)

    钟博扬; 李芳芳; 陈长安; 罗文华

    2016-01-01

    With the continuous development of membrane separation technology,palladium membranes for hy-drogen permeation have been widely used for hydrogen purification and separation due to their excellent permeability, hydrogen selectivity,as well as chemical and thermal stabilities.The types of palladium membranes,permeation mechanism of hydrogen,and their fabrication methods are reviewed.The development and hydrogen permeation per-formance of palladium membranes are summarized from the initial pure palladium membranes to the palladium alloy membranes and palladium composite membranes.As a representative of new Pd/bcc composite membranes,the nio-bium and palladium composite membrane is mainly introduced.%随着膜分离技术的不断发展,渗氢用钯基膜由于具有优异的透氢速率、透氢选择性及良好的化学和热稳定性,已被广泛应用于氢提纯分离领域。介绍了钯透氢膜的种类、透氢机理和制备方法,总结了钯膜从最初的纯钯膜、钯合金膜到钯复合膜的发展历程和氢渗透性能研究,并重点介绍了以铌钯复合膜为代表的新型 Pd/bcc 型复合膜氢渗透性能的研究进展。

  11. Effect of weave tightness and structure on the in-plane and through-plane air permeability of woven carbon fibers for gas diffusion layers

    Energy Technology Data Exchange (ETDEWEB)

    Caston, Terry B.; Murphy, Andrew R.; Harris, Tequila A.L. [Department of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA (United States)

    2011-01-15

    In this study, woven gas diffusion layers (GDLs) with varying weave type and tightness are investigated. Plain and twill weave patterns were manufactured in-house. The in-plane and through-plane air permeability of the woven samples were tested, and mercury intrusion porosimetry (MIP) tests were performed to study the pore structure. It was found that the twill weave has a higher permeability than the plain weave, which is consistent with literature. Like non-woven carbon papers, woven GDLs have higher in-plane permeability than through-plane permeability; however it has been shown that it is possible to manufacture a GDL with higher through-plane permeability than in-plane permeability. It was also concluded that the percentage of macropores in the weave is the driving factor in determining the through-plane air permeability. This work lays the groundwork for future studies to attempt to characterize the relationship between the weave structure and the air permeability in woven GDLs. (author)

  12. Fabrication of VB2/air cells for electrochemical testing.

    Science.gov (United States)

    Stuart, Jessica; Lopez, Ruben; Lau, Jason; Li, Xuguang; Waje, Mahesh; Mullings, Matthew; Rhodes, Christopher; Licht, Stuart

    2013-08-05

    A technique to investigate the properties and performance of new multi-electron metal/air battery systems is proposed and presented. A method for synthesizing nanoscopic VB2 is presented as well as step-by-step procedure for applying a zirconium oxide coating to the VB2 particles for stabilization upon discharge. The process for disassembling existing zinc/air cells is shown, in addition construction of the new working electrode to replace the conventional zinc/air cell anode with a the nanoscopic VB2 anode. Finally, discharge of the completed VB2/air battery is reported. We show that using the zinc/air cell as a test bed is useful to provide a consistent configuration to study the performance of the high-energy high capacity nanoscopic VB2 anode.

  13. Fabrication of VB2/Air Cells for Electrochemical Testing

    OpenAIRE

    Stuart, Jessica; Lopez, Ruben; Lau, Jason; Li, Xuguang; Waje, Mahesh; Mullings, Matthew; Rhodes, Christopher; Licht, Stuart

    2013-01-01

    A technique to investigate the properties and performance of new multi-electron metal/air battery systems is proposed and presented. A method for synthesizing nanoscopic VB2 is presented as well as step-by-step procedure for applying a zirconium oxide coating to the VB2 particles for stabilization upon discharge. The process for disassembling existing zinc/air cells is shown, in addition construction of the new working electrode to replace the conventional zinc/air cell anode with a the nanos...

  14. Toward an Active Fabric-Based Air Decontamination System

    Science.gov (United States)

    2004-12-01

    of heterogeneous photo - catalysis on TiO2 . The infrared spectra acquired after irradiation indicate the degradation of CHCl3 due to the...against chemical warfare. Titanium dioxide is widely recognized as a powerful photo -oxidation catalyst.1-3 Research groups have shown TiO2 to be...Successful demonstration of titanium photo - catalysis on fabrics would aid in fostering the transition of this technology into service. Possible

  15. Gas diffusion, non-darcy air permeability and CT-scans for a traffic-affected clay subsoil

    DEFF Research Database (Denmark)

    Lamandé, Mathieu; Schjønning, Per; Berisso, Feto Esimo

    2013-01-01

    The objective of this study was to evaluate the long-term effect of compaction on the pore system at 0.5 m depth of a heavy clay soil in Jokioinen, Finland. Gas diffusion and air permeability measurements were combined with pycnometer-estimated air-filled pore volumes. We wanted to evaluate...... pressure drops. Compaction at 50 cm depth was persistent 29 years after the compaction event. Compaction diminished the size of vertical macropores that served as arterial pores, while the volume and role of marginal pores branching from the arterial pores were diminished. Compacted soil had...... the significantly lowest volume of blocked pores not in contact to the surrounding atmosphere. For this clay-holding soil, the long-term compaction effect is interpreted as a serious reduction of the aeration potential of the bulk soil matrix in between the vertical, arterial pores. Our data indicate a high degree...

  16. Fabrication of solid-cladding photonic band gap fiber with air core

    Science.gov (United States)

    Kujawa, I.; Pysz, D.; Buczyński, R.; Filipkowski, A.; Nowosielski, J.; Stępień, R.

    2008-06-01

    In this paper we report on fabrication of all-Solid photonic Cladding and Air Core fiber (SCAC fiber). As far as we know it is a first reported fabrication of such PCF. Microrods are made of commercially available lead-oxide F2 glass (SCHOTT Inc.) with a refractive index nD=1.619, while as background we use a borosilicate NC21 glass synthesized in-house at ITME with a refractive index nD=1.533. A fabricated fiber has a lattice constant of Λ~7.49μm and microrods diameter of d~4.0μm. Air core has a diameter of DR=3.67μm and total fiber diameter is Dfiber=123.80μm.

  17. Fabrication of a smart air intake structure using shape memory alloy wire embedded composite

    Science.gov (United States)

    Jung, Beom-Seok; Kim, Min-Saeng; Kim, Ji-Soo; Kim, Yun-Mi; Lee, Woo-Yong; Ahn, Sung-Hoon

    2010-05-01

    Shape memory alloys (SMAs) have been actively studied in many fields utilizing their high energy density. Applying SMA wire-embedded composite to aerospace structures, such as air intake of jet engines and guided missiles, is attracting significant attention because it could generate a comparatively large actuating force. In this research, a scaled structure of SMA wire-embedded composite was fabricated for the air intake of aircraft. The structure was composed of several prestrained Nitinol (Ni-Ti) SMA wires embedded in ∩-shape glass fabric reinforced plastic (GFRP), and it was cured at room temperature for 72 h. The SMA wire-embedded GFRP could be actuated by applying electric current through the embedded SMA wires. The activation angle generated from the composite structure was large enough to make a smart air intake structure.

  18. Fabrication of a smart air intake structure using shape memory alloy wire embedded composite

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Beom-Seok; Kim, Min-Saeng; Kim, Ji-Soo; Kim, Yun-Mi [School of Mechanical and Aerospace Engineering, Seoul National University, Shinlim-Dong San 56-1, Kwanak-Gu, Seoul 151-742 (Korea, Republic of); Lee, Woo-Yong [Agency for Defense Development, Jochiwongil 462, Yuseong-Gu, Daejeon 305-600 (Korea, Republic of); Ahn, Sung-Hoon, E-mail: ahnsh@snu.ac.k [School of Mechanical and Aerospace Engineering and Institute of Advanced Machinery and Design, Seoul National University, Shinlim-Dong San 56-1, Kwanak-Gu, Seoul 151-742 (Korea, Republic of)

    2010-05-01

    Shape memory alloys (SMAs) have been actively studied in many fields utilizing their high energy density. Applying SMA wire-embedded composite to aerospace structures, such as air intake of jet engines and guided missiles, is attracting significant attention because it could generate a comparatively large actuating force. In this research, a scaled structure of SMA wire-embedded composite was fabricated for the air intake of aircraft. The structure was composed of several prestrained Nitinol (Ni-Ti) SMA wires embedded in intersection -shape glass fabric reinforced plastic (GFRP), and it was cured at room temperature for 72 h. The SMA wire-embedded GFRP could be actuated by applying electric current through the embedded SMA wires. The activation angle generated from the composite structure was large enough to make a smart air intake structure.

  19. Design and Fabrication of Air-Based 1-3 Piezoelectric Composite Transducer for Air-Coupled Ultrasonic Applications

    Directory of Open Access Journals (Sweden)

    Cunfu He

    2016-01-01

    Full Text Available The air-based 1-3 piezoelectric composite transducers are designed and fabricated in order to solve the acoustic impedance matching problem. Firstly, a finite element model using honeycomb structure as the piezoelectric composite matrix is built to reduce the acoustic impedance of the sensitive element. Three important factors, volume fraction of piezoelectric materials φ, the thickness h, and the size s of the square cross section of piezoelectric column, are examined and verified in simulation. Then, according to the result of simulation, the piezoelectric composites and the air-coupled transducers are fabricated. The honeycomb structures of resin are produced by the method of 3D printing technology, with the volume fraction of air being 30%. The impedance characteristics and the excitation/reception performance of the air-coupled transducers are measured and optimized. Meanwhile, a scanning experiment is carried out to demonstrate the crack detection process in monocrystalline silicon. A0 mode of Lamb waves is excited and collected. The location and size of the defect will be determined by calculating the correlation coefficients of the received signals and reference signals. Finally, a 15 mm × 0.5 mm × 0.5 mm scratch is clearly distinguished.

  20. Approach of UV nanoimprint lithography using template with gas-permeable and gaseous adsorption for reduction of air-trapping issue

    Science.gov (United States)

    Takei, Satoshi; Sugino, Naoto; Kameda, Takao; Nakajima, Shinya; Hanabata, Makoto

    2016-10-01

    In this paper, we studied a novel approach, UV nanoimprint lithography using glucose-based template with gaspermeable and gaseous adsorption for reduction of air-trapping issue. The air-trapping issue in UV nanoimprint lithography resist is a cause of pattern failure in resist or UV curable materials. The results of 180 nm dense line patterning of UV curable patterning materials containing acetone in UV nanoimprint lithography using glucose-based template with gas-permeable and gaseous adsorption were effected to reduce the pattern failure as compared with that of the poly(dimethylsiloxane) without gas-permeable and gaseous adsorption as the reference. The proposed UV nanoimprint lithography using glucose-based template with gas-permeable and gaseous adsorption is one of the most promising processes ready to be investigated for mass-production of photomask applications.

  1. Anti-fouling and high water permeable forward osmosis membrane fabricated via layer by layer assembly of chitosan/graphene oxide

    Science.gov (United States)

    Salehi, Hasan; Rastgar, Masoud; Shakeri, Alireza

    2017-08-01

    To date, forward osmosis (FO) has received considerable attention due to its potential application in seawater desalination. FO does not require external hydraulic pressure and consequently is believed to have a low fouling propensity. Despite the numerous privileges of FO process, a major challenge ahead for its development is the lack of high performance membranes. In this study, we fabricated a novel highly-efficient FO membrane using layer-by-layer (LbL) assembly of positive chitosan (CS) and negative graphene oxide (GO) nanosheets via electrostatic interaction on a porous support layer. The support layer was prepared by blending hydrophilic sulfonated polyethersulfone (SPES) into polyethersulfone (PES) matrix using wet phase inversion process. Various characterization techniques were used to confirm successful fabrication of LbL membrane. The number of layers formed on the SPES-PES support layer was easily adjusted by repeating the CS and GO deposition cycles. Thin film composite (TFC) membrane was also prepared by the same SPES-PES support layer and polyamide (PA) active layer to compare membranes performances. The water permeability and salt rejection of the fabricated membranes were obtained by two kinds of draw solutions (including Na2SO4 and sucrose) under two different membrane orientations. The results showed that membrane coated by a CS/GO bilayers had water flux of 2-4 orders of magnitude higher than the TFC one. By increasing the number of CS/GO bilayers, the selectivity of the LbL membrane was improved. The novel fabricated LbL membrane showed better fouling resistance than the TFC one in the feed solution containing 200 ppm of sodium alginate as a foulant model.

  2. Research on Properties of Woven Fabrics Treated by High Pressure Water Jet

    Institute of Scientific and Technical Information of China (English)

    黄故

    2001-01-01

    The paper introduces a new technique for the treatment of the woven fabrics. Sprayed by high pressure water jet, the appearance, handle and stiffness of the fabric are improved. Other properties of the high pressure water treated fabrics like drape coefficient, air permeability, tenacity are also presented.

  3. EFFECTS OF DYNEL FIBER BLENDING ON YARN SHRINKAGE AND WOVEN-FABRIC PROPERTIES

    Science.gov (United States)

    A 50/50 picker blend warp was woven with fillings from the various blends and twists. The fabrics were scoured and treated for water repellency . Highest...results of yarn and fabric shrinkage and air permeability. All water repellency tests were poor; fabrics with low-twist fillings were better than those

  4. Weaving Processing Optimization of Waterproof Permeable Fabric%防水透湿织物织造工艺的优化

    Institute of Scientific and Technical Information of China (English)

    蔡东照; 胥正安

    2011-01-01

    探讨防水透湿织物的织造工艺要点.选用超细涤纶高收缩纤维,结合高密度织物组织设计,通过优选卷取方式、经纱张力、开口时间、送经张力补偿弹簧圈数、筘的空间率等工艺参数,认为选用W型卷取方式、适当降低经纱张力、适当提早开口时间、合理选择筘的空间率等,可使织机效率得到有效提高.%Weaving processing key points of waterproof permeable fabric were discussed. Superfine polyester shrinkage fiber was selected, combining high density fabric weave design, processing parameter was optimized including take-up style,warp tension, shed time,warp let-off tension compensation spring coils,reed density et al. It is considered that loom efficiency could be improved effectively when adopting W type take-up, reducing warp tension properly, setting shed time early,selecting reed density rationally et al.

  5. Oxygen permeable membrane for oxygen enriched combustion

    Energy Technology Data Exchange (ETDEWEB)

    Asakawa, S. (Matsushita Research Inst., Tokyo, Japan); Saito, Y.; Kawahito, M.; Ito, Y.; Tsuchiya, S.; Sugata, K.

    1983-02-01

    An oxygen enriched air production system using gas separation membranes has been developed to be used for fuel combustion systems. High oxygen permeable scopolymers, including three dimensional structure, have been synthesized through condensation of polyvinylphenol with some, ..cap alpha..,..omega..-bis (diethylamino) polydimethylsiloxanes. The experimental results showed that the oxygen permeability through the copolymer varies as a function of the dimethylsiloxane content of the copolymers. Such composition dependence of the oxygen permeability was explained on the basis of polymer constitution. Typical values of the oxygen permeability, 3.4 x 10/sup -8/ (cc x cm/cm/sup 2/ x sec x cmHg) and ..cap alpha.., 2.1, were obtained at 72% of dimethylsiloxane content. The copolymers are soluble in most common organic solvents and uniform, defect-free membranes as thin as 1000 Angstroms have been formed by spreading solutions of the copolymer on water. Composite membranes fabricated by applying the membranes to porous support materials were used for practical gas separation and 30% oxygen enriched air was produced from ambient air. A new type oxygen enriched combustion system, which is more efficient for energy saving, has been developed by utilizing oxygen enriched air thus produced. 15 references, 15 figures, 1 table.

  6. Electrospinning Fabrication and Performance Evaluation of Polyacrylonitrile Nanofiber for Air Filter Applications

    Directory of Open Access Journals (Sweden)

    Nguyen Duy Vinh

    2016-08-01

    Full Text Available Nano materials possess unique mechanical, physical, and chemical properties. They are small, and have an ultrahigh surface area, making them suitable for air filter applications since air filtration is necessary to protect sensitive components from harmful particulates and gaseous contaminants. The electrospinning method has been recognized as an efficient technique for fabricating polymer nanofibers. In order to determine the optimum manufacturing conditions, the effects of several electrospinning process parameters on the diameter, orientation, and distribution of polyacrylonitrile (PAN nanofiber are analyzed. To improve interlaminar fracture toughness and suppress the delamination in the form of laminated non-woven fibers by using a heat roller, the performances of filter efficiency and pressure drop achieved with the PAN nanofiber air filter are evaluated experimentally.

  7. Physical and Thermal Comfort Properties of Viscose Fabrics made from Vortex and Ring Spun Yarns

    Science.gov (United States)

    Thilagavathi, G.; Muthukumar, N.; Kumar, V. Kiran; Sadasivam, Sanjay; Sidharth, P. Mithun; Nikhil Jain, G.

    2016-11-01

    Viscose fiber is frequently preferred for various types of inner and outer knitwear products for its comfort and visual characteristics. In this study, the physical and thermal comfort properties of viscose fabrics made from ring and vortex yarns have been studied to explore the impact of spinning process on fabric properties. 100% viscose fibers were spun into yarns by ring and vortex spinning and the developed yarns were converted to single jersey fabrics. The results indicated that fabrics made from vortex spun yarns had better pilling resistance over that of those from ring spun yarns. There was no significant difference between bursting strength values of vortex and ring spun yarn fabrics. Fabrics made from ring yarn had better dimensional stability compared to fabrics made from vortex yarn. The air permeability and water vapour permeability of vortex yarn fabrics were higher than ring spun yarn fabrics. The vortex yarn fabrics had better thermal comfort properties compared to ring yarn fabrics.

  8. Fabrication

    Directory of Open Access Journals (Sweden)

    E.M.S. Azzam

    2013-12-01

    Full Text Available In the present work, the nanoclay composites were fabricated using the synthesized poly 6-(3-aminophenoxy hexane-1-thiol, poly 8-(3-aminophenoxy octane-1-thiol and poly 10-(3-aminophenoxy decane-1-thiol surfactants with gold nanoparticles. The polymeric thiol surfactants were first assembled on gold nanoparticles and then impregnated into the clay matrix. Different spectroscopic and microscopic techniques such as X-ray diffraction (XRD, Scanning electron microscope (SEM and Transmission microscope (TEM were used to characterize the fabricated nanoclay composites. The results showed that the polymeric thiol surfactants assembled on gold nanoparticles are located in the interlayer space of the clay mineral and affected the clay structure.

  9. Methods of PCM microcapsules application and the thermal properties of modified knitted fabric

    Energy Technology Data Exchange (ETDEWEB)

    Nejman, Alicja, E-mail: anejman@iw.lodz.pl [Textile Research Institute, Scientific Department of Unconventional Technologies and Textiles, 5/15 Brzezinska St., 92-103 Lodz (Poland); Cieślak, Małgorzata [Textile Research Institute, Scientific Department of Unconventional Technologies and Textiles, 5/15 Brzezinska St., 92-103 Lodz (Poland); Gajdzicki, Bogumił [Textile Research Institute, Scientific Department of Textile Chemistry and Products Modification, 5/15 Brzezinska St., 92-103 Lodz (Poland); Goetzendorf-Grabowska, Bogna; Karaszewska, Agnieszka [Textile Research Institute, Scientific Department of Unconventional Technologies and Textiles, 5/15 Brzezinska St., 92-103 Lodz (Poland)

    2014-08-10

    Highlights: • We applied microcapsules containing n-octadecane for the modification of knitted fabric. • We used printing, coating and padding techniques for the application of microcapsules. • M-PCM application methods allow to regulate the thermal properties of textiles. • M-PCM application methods allow to regulate the air permeability properties of textiles. - Abstract: The aim of the study is to analyze the impact of application methods of microcapsules containing n-octadecane as phase change materials (M-PCM) on the thermal properties and air permeability of modified textile fabric. Polyester knitted fabric, printing, coating and padding methods and polymer pastes with 20 wt.% of M-PCM were used. For the assessment of modification effects the differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) were used. DSC analysis showed that the highest enthalpy of phase transitions has printed fabric and the lowest padded fabric. The widest range of phase transitions temperatures was observed for printed fabric, slightly narrower for coated fabric and the narrowest for padded fabric. SEM analysis showed differences in the morphology of modified fabrics depending on incorporation techniques, which are compatible with differences in air permeability results. M-PCM application techniques allow to regulate the thermal and air permeability properties of fabric.

  10. Highly effective permeability and antifouling performances of polypropylene non-woven fabric membranes modified with graphene oxide by inkjet printing and immersion coating methods.

    Science.gov (United States)

    Zhao, Chuan-Qi; Xu, Xiao-Chen; Li, Rui-Yun; Chen, Jie; Yang, Feng-Lin

    2013-01-01

    In the current study, graphene oxide (GO)-modified polypropylene non-woven fabric (PP-NWF) membranes were prepared via inkjet printing and immersion coating methods. Scanning electron microscopy, Fourier transform infrared spectroscopy, contact angle measurements, pure water permeation (JPWP) and protein adsorption were tested to evaluate the impact of the GO nanosheet on the characteristics and performance of modified PP-NWF membranes. The results showed that the exfoliated GO nanosheets uniformly deposited on the membrane surface and firmly embedded into the interlaced fibers, resulting in the improvement of membrane hydrophilicity, permeability and antifouling properties comparing with original PP-NWF membranes. The GO-printed and GO-coated membranes had 113 and 188% higher fluxes, and 70.95 and 75.74% lower protein adsorptions than the original PP-NWF membranes, respectively. After cross-linked treatment, ultrasound processing was conducted to evaluate the stability of the modified PP-NWF membranes. The results demonstrated that there was almost no decrease in permeation after ultrasonic treatment indicating that the cross-linking treatment could enhance the immobilization of the GO nanosheets on and into the modified membranes.

  11. Diffuse plasma treatment of polyamide 66 fabric in atmospheric pressure air

    Science.gov (United States)

    Li, Lee; Peng, Ming-yang; Teng, Yun; Gao, Guozhen

    2016-01-01

    The polyamide 66 (PA66) fabrics are hard to be colored or glued in industrial production due to the poor hydrophily. Diffuse plasma is a kind of non-thermal plasma generated at atmospheric pressure in air. This paper proposes that large-scale diffuse plasma generated between wire electrodes can be employed for improving the hydrophily of PA66 fabrics. A repetitive nanosecond-pulse diffuse-discharge reactor using a cylindrical wire electrode configuration is presented, which can generate large-scale non-thermal plasmas steadily at atmospheric pressure without any barrier dielectric. Then the reactor is used to treat PA66 fabrics in different discharge conditions. The hydrophilicity property of modified PA66 is measured by wicking test method. The modified PA66 is also analyzed by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) to prove the surface changes in physical microstructure and chemical functional groups, respectively. What's more, the effects of treatment time and treatment frequency on surface modification are investigated and discussed.

  12. Prevention of asthma induced by cold air by cellulose-fabric face mask.

    Science.gov (United States)

    Millqvist, E; Bake, B; Bengtsson, U; Löwhagen, O

    1995-03-01

    We have tested the effect of a porous cellulose fabric face mask. Nine asthmatic patients, anamnestically sensitive to cold, took part in exercise tests on an ergometer bicycle at a temperature of approximately -10 degrees C, with and without a face mask. For comparison, exercise tests were also performed with breathing taking place through a woolen scarf. Three minutes after finishing the exercise test, there was an average fall in FEV1 of 32% in the group without a face mask. The corresponding fall in FEV1 was 6% with a face mask and 17% with a scarf. In order to get some idea of the patients' attitudes to the face mask, it was used by 25 asthma patients during a period of 2 weeks in winter, after which they were asked to answer a simple questionnaire. Eighty-eight percent of the patients stated that the face mask had provided satisfactory protection against asthma complaints induced by cold air, and 72% reported that they had been able to spend more time out-of-doors. The results show that porous cellulose fabric designed as a face mask offers effective protection against asthma complaints induced by cold air and exercise, and that the patients appear to appreciate this protective aid highly despite the cosmetic disadvantages.

  13. Unsaturated and Saturated Permeabilities of Fiber Reinforcement: Critics and Suggestions

    Directory of Open Access Journals (Sweden)

    Chung Hae ePARK

    2015-04-01

    Full Text Available In general, permeability measurement results show a strong scattering according to the measurement method, the type of test fluid and the fluid injection condition, even though permeability is regarded as a unique property of porous medium. In particular, the discrepancy between the unsaturated and saturated permeabilities for the same fabric has been widely reported. In the literature, relative permeability has been adopted to model the unsaturated flow. This approach has some limits in the modeling of double-scale porosity medium. We address this issue of permeability measurement by rigorously examining the mass conservation condition. Finally, we identify that the pressure gradient is non-linear with positive curvature in the unsaturated flow and a misinterpretation of pressure gradient is the main reason for the difference between the saturated and unsaturated permeabilities of the same fiber reinforcement. We propose to use a fixed value of permeability and to modify the mass conservation equation if there are air voids which are entrapped inside the fiber tow. Finally, we also suggest some guidelines and future perspectives to obtain more consistent permeability measurement results.

  14. Unsaturated and Saturated Permeabilities of Fiber Reinforcement: Critics and Suggestions

    Science.gov (United States)

    Park, Chung Hae; Krawczak, Patricia

    2015-04-01

    In general, permeability measurement results show a strong scattering according to the measurement method, the type of test fluid and the fluid injection condition, even though permeability is regarded as a unique property of porous medium. In particular, the discrepancy between the unsaturated and saturated permeabilities for the same fabric has been widely reported. In the literature, relative permeability has been adopted to model the unsaturated flow. This approach has some limits in the modeling of double-scale porosity medium. We address this issue of permeability measurement by rigorously examining the mass conservation condition. Finally, we identify that the pressure gradient is non-linear with positive curvature in the unsaturated flow and a misinterpretation of pressure gradient is the main reason for the difference between the saturated and unsaturated permeabilities of the same fiber reinforcement. We propose to use a fixed value of permeability and to modify the mass conservation equation if there are air voids which are entrapped inside the fiber tow. Finally, we also suggest some guidelines and future perspectives to obtain more consistent permeability measurement results.

  15. Fabrication of air-bridged Kerr nonlinear polymer photonic crystal slab structures in near-infrared region

    Institute of Scientific and Technical Information of China (English)

    Ziming Meng; Xiaolan Zhong; Chen Wang; Zhiyuan Li

    2012-01-01

    Fabrication details of air-bridged Kerr nonlinear polymer photonic crystal slab structures are presented.Both the two-dimensional photonic crystal slab and the one-dimensional nanobeam structures are fabricated using direct focused ion beam etching and subsequent wet chemical etching.The scanning electron microscopy images show the uniformity and homogeneity of the cylindrical air holes.The optical measurement in the near-infrared region is implemented using the tapered fiber coupling method,and the results agree with the numerical calculations by using the three-dimensional finite-difference time-domain method.

  16. Controllable Impregnation Via Inkjet Printing for the Fabrication of Solid Oxide Cell Air Electrodes

    KAUST Repository

    Da'as, E. H.

    2013-10-07

    The impregnation method has been considered as one of the most successful techniques for the fabrication of highly efficient electrodes for solid oxide fuel and electrolysis cells (SOCs) at the lab scale. However, because the impregnation is usually performed manually, its irreproducibility remains a major problem that can be solved by using controllable techniques, such as inkjet printing. In this paper, lanthanum strontium manganite (LSM)/yttria stabilized zirconia (YSZ) air electrodes were prepared by infiltrating YSZ porous bodies with LSM precursor solution using inkjet printing, followed by annealing at 800°C for 2 hours. XRD analysis confirmed the formation of the LSM phase, which was in the form of nanoparticles with size in the 50-70 nm range on the YSZ walls, as revealed by FEG-SEM observations. The effect of printing parameters on the distribution of the impregnated phase was investigated and discussed.

  17. ZnO nanorods/AZO photoanode for perovskite solar cells fabricated in ambient air

    Science.gov (United States)

    La Ferrara, Vera; De Maria, Antonella; Rametta, Gabriella; Della Noce, Marco; Vittoria Mercaldo, Lucia; Borriello, Carmela; Bruno, Annalisa; Delli Veneri, Paola

    2017-08-01

    ZnO nanorods are a good candidate for replacing standard photoanodes, such as TiO2, in perovskite solar cells and in principle superseding the high performances already obtained. This is possible because ZnO nanorods have a fast electron transport rate due to their large surface area. An array of ZnO nanorods is grown by chemical bath deposition starting from Al-doped ZnO (AZO) used both as a seed layer and as an efficient transparent anode in the visible spectral range. In particular, in this work we fabricate methylammonium lead iodide (CH3NH3PbI3) perovskite solar cells using glass/AZO/ZnO nanorods/perovskite/Spiro-OMeTAD/Au as the architecture. The growth of ZnO nanorods has been optimized by varying the precursor concentrations, growth time and solution temperature. All the fabrication process and photovoltaic characterizations have been carried out in ambient air and the devices have not been encapsulated. Power conversion efficiency as high as 7.0% has been obtained with a good stability over 20 d. This is the highest reported value to the best of our knowledge and it is a promising result for the development of perovskite solar cells based on ZnO nanorods and AZO.

  18. Properties of honeycomb polyester knitted fabrics

    Science.gov (United States)

    Feng, A. F.

    2016-07-01

    The properties of honeycomb polyester weft-knitted fabrics were studied to understand their advantages. Seven honeycomb polyester weft-knitted fabrics and one common polyester weft-knitted fabric were selected for testing. Their bursting strengths, fuzzing and pilling, air permeability, abrasion resistance and moisture absorption and perspiration were studied. The results show that the honeycomb polyester weft-knitted fabrics have excellent moisture absorption and liberation. The smaller their thicknesses and area densities are, the better their moisture absorption and liberation will be. Their anti-fuzzing and anti-pilling is good, whereas their bursting strengths and abrasion resistance are poorer compared with common polyester fabric's. In order to improve the hygroscopic properties of the fabrics, the proportion of the honeycomb microporous structure modified polyester in the fabrics should not be less than 40%.

  19. Studies with the USF/NASA toxicity screening test method - Effect of air flow and effect of fabric dye

    Science.gov (United States)

    Hilado, C. J.; Lopez, M. T.

    1976-01-01

    One sample each of commercial polyurethane and polychloroprene flexible foams were evaluated using the USF/NASA toxicity screening test method. Air flow rates of 0, 0.16, 16, and 48 ml/sec were used to determine the effect of air flow on relative toxicity. Time to first sign of incapacitation and time to death were substantially reduced with both polyurethane and polychloroprene flexible foams by the introduction of 16 to 48 ml/sec air flow. The relative toxicity rankings of these materials were not altered by changes in air flow. Under these test conditions, the polyurethane foam consistently appeared more toxic than the polychloroprene foam. Samples of six different colors from the same fabric were evaluated separately, using the USF/NASA toxicity screening test method, to determine the effect of fabric dye, if any. The material was an upholstery fabric, consisting of 46 percent cotton, 33 percent wool, and 21 percent nylon. There appeared to be no significant effect of fabric dye on relative toxicity, for this material under these test conditions.

  20. Microfabricated Air-Microfluidic Sensor for Personal Monitoring of Airborne Particulate Matter: Design, Fabrication, and Experimental Results

    Science.gov (United States)

    We present the design and fabrication of a micro electro mechanical systems (MEMS) air-microfluidic particulate matter (PM) sensor, and show experimental results obtained from exposing the sensor to concentrations of tobacco smoke and diesel exhaust, two commonly occurring P...

  1. STRETCH FABRICS IN LEATHER MANUFACTURING: PERFORMANCE PROPERTIES OF STRECH LEATHERS

    Directory of Open Access Journals (Sweden)

    ORK Nilay

    2016-05-01

    Full Text Available Product variability of manufactured leather goods such as garment leathers could be closely related to the wear comfort because each material forming the garments are affected the comfort properties of the products. Considering the significant demand to elastic woven stretch fabrics and the advantages provided to leather goods like allowing easy body movements, well-fitting and keeping the shape make the use of stretch fabrics focus in interest. In this study, the performance properties of stretch leathers, leathers and spandex fabrics were presented and the differences between the characteristic properties of the leathers were described. For this purpose, physical characteristics of leathers were investigated in terms of thickness, weight, drape ability, stiffness, bending stiffness, air and water vapor permeability. The drape ability, stiffness and bending stiffness properties were significantly affected by the stretch fabrics laminated on the suede side of the leathers. The drape ability, stiffness and bending values were increased due to the implementation of stretch fabrics. There was no significant difference between the air permeability values of the leathers prior and after the implementation of stretch fabrics in contrast to water vapor permeability. The results of this study showed that the aesthetic behavior of clothing materials such as drape and stiffness properties as well as water vapor permeability was mainly affected from the implementation of the stretch fabrics.

  2. Fine-Tuned Intrinsically Ultramicroporous Polymers Redefine the Permeability/Selectivity Upper Bounds of Membrane-Based Air and Hydrogen Separations

    KAUST Repository

    Swaidan, Raja

    2015-08-20

    Intrinsically ultramicroporous (<7 Å) polymers represent a new paradigm in materials development for membrane-based gas separation. In particular, they demonstrate that uniting intrachain “rigidity”, the traditional design metric of highly permeable polymers of intrinsic microporosity (PIMs), with gas-sieving ultramicroporosity yields high-performance gas separation membranes. Highly ultramicroporous PIMs have redefined the state-of-the-art in large-scale air (e.g., O2/N2) and hydrogen recovery (e.g., H2/N2, H2/CH4) applications with unprecedented molecular sieving gas transport properties. Accordingly, presented herein are new 2015 permeability/selectivity “upper bounds” for large-scale commercial membrane-based air and hydrogen applications that accommodate the substantial performance enhancements of recent PIMs over preceding polymers. A subtle balance between intrachain rigidity and interchain spacing has been achieved in the amorphous microstructures of PIMs, fine-tuned using unique bridged-bicyclic building blocks (i.e., triptycene, ethanoanthracene and Tröger’s base) in both ladder and semiladder (e.g., polyimide) structures.

  3. Flexible inverted polymer solar cells fabricated in air at low temperatures

    Science.gov (United States)

    Kuwabara, Takayuki; Wang, Xiaofan; Kusumi, Takuji; Yamaguchi, Takahiro; Taima, Tetsuya; Takahashi, Kohshin

    2016-08-01

    A series of modified indium tin oxide (ITO) materials, including sol-gel zinc-oxide-coated ITO (ITO/ZnO), ZnO nanoparticle-coated ITO (ITO/ZnO-NP), 1,4-bis(3-aminopropyl)piperazine (BAP)-modified ITO, and polyethylenimine ethoxylated (PEIE)-modified ITO, were used for electron-collection electrodes in inverted polymer solar cells (PSCs). The modified ITO electrodes were prepared in air at temperatures below 100 °C, using various ITO films on flexible poly(ethylene terephthalate) substrates (PET-ITO) with sheet resistances ranging from 12 to 60 Ω sq-1. The PET-ITO (12 Ω sq-1)/ZnO-NP PSC exhibited an improved power conversion efficiency (PCE) (2.93%), and this PCE was ˜90% of that observed for a cell using glass-ITO/ZnO-NP (sheet resistance = 10 Ω sq-1 PCE = 3.28%). Additionally, we fabricated a flexible inverted ZnO-NP PSC using an indene-C60 bisadduct (ICBA) as the acceptor material in place of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and obtained a PCE of 4.18%.

  4. Evaluation of Bed Cover Properties Produced from Double Fabric Based on Honeycomb

    Directory of Open Access Journals (Sweden)

    A. A. Salama

    2015-01-01

    Full Text Available This research aims to innovate a new fabric structure, which could be used as a bed cover based on double honeycomb fabric with self-stitching. The honeycomb air pockets were aimed at facing each other to form closed small air chambers which work to sequester the air. The double fabric increases fabric thickness. Thus, the opportunity to improve thermal comfort could be achieved. A number of samples were produced with different densities and counts of weft yarn. Thermal insulation and water vapour permeability were measured and compared with bed covers produced from reversible weft backed structure. Geometrical properties, abrasion resistance, and air permeability were also measured. The results showed that the innovated structure had higher values of thermal insulation than reversible weft backed structure at certain weft counts and densities.

  5. Permeability measuremens of brazilian Eucalyptus

    Directory of Open Access Journals (Sweden)

    Marcio Rogério da Silva

    2010-09-01

    Full Text Available The permeability of Brazilian Eucalyptus grandis and Eucalyptus citriodora wood was measured in a custom build gas analysis chamber in order to determine which species could be successfully treated with preservatives. Liquid permeability was tested using an emulsion of Neen oil and a control of distillated water. Air was used to test the gas phase permeability. For both Eucalyptus grandis and Eucalyptus citriodora, the longitudinal permeability of gas was shown to be about twice as great as the liquid phase permeability. No radial permeability was observed for either wood. The permeability of air and water through the sapwood of Eucalyptus grandis was greater than that through the sapwood of Eucalyptus citriodora. The permeability of neen oil preservative through the sapwood of Eucalyptus grandis was also greater than through the sapwood of E. Citradora, but the difference was not statistically significant. Scanning Electron Microscopy images showed that the distribution and obstruction in the vessels could be correlated with observed permeability properties. Irrespective of the causes of differences in permeability between the species, the fluid phase flux through the sapwood of both species was significant, indicating that both Eucalyptus grandis and Eucalyptus citriodora could be successfully treated with wood preservative.

  6. Notional Permeability

    NARCIS (Netherlands)

    Kik, R.; Van den Bos, J.P.; Maertens, J.; Verhagen, H.J.; Van der Meer, J.W.

    2012-01-01

    Different layer design of a rock slope and under layers has a large effect on the strengths on the rock slope itself. In the stability formula developed of VAN DER MEER [1988] this effect is represented by the term Notional Permeability with symbol P. A more open, or permeable, structure underneath

  7. A novel approach to regulate cell membrane permeability for ATP and NADH formation in Saccharomyces cerevisiae induced by air cold plasma

    Science.gov (United States)

    Xiaoyu, DONG; Tingting, LIU; Yuqin, XIONG

    2017-02-01

    Air cold plasma has been used as a novel method for enhancing microbial fermentation. The aim of this work was to explore the effect of plasma on membrane permeability and the formation of ATP and NADH in Saccharomyces cerevisiae, so as to provide valuable information for large-scale application of plasma in the fermentation industry. Suspensions of S. cerevisiae cells were exposed to air cold plasma for 0, 1, 2, 3, 4 and 5 min, and then subjected to various analyses prior to fermentation (0 h) and at the 9 and 21 h stages of fermentation. Compared with non-exposed cells, cells exposed to plasma for 1 min exhibited a marked increase in cytoplasmic free Ca2+ concentration as a result of the significant increase in membrane potential prior to fermentation. At the same time, the ATP level in the cell suspension decreased by about 40%, resulting in a reduction of about 60% in NADH prior to culturing. However, the levels of ATP and NADH in the culture at the 9 and 21 h fermentation stages were different from the level at 0 h. Taken together, the results indicated that exposure of S. cerevisiae to air cold plasma could increase its cytoplasmic free Ca2+ concentration by improving the cell membrane potential, consequently leading to changes in ATP and NADH levels. Supported by National Natural Science Foundation of China (Nos. 21246012, 21306015 and 21476032).

  8. Langmuir nanoarchitectonics: one-touch fabrication of regularly sized nanodisks at the air-water interface.

    Science.gov (United States)

    Mori, Taizo; Sakakibara, Keita; Endo, Hiroshi; Akada, Misaho; Okamoto, Ken; Shundo, Atsuomi; Lee, Michael V; Ji, Qingmin; Fujisawa, Takuya; Oka, Kenichiro; Matsumoto, Mutsuyoshi; Sakai, Hideki; Abe, Masahiko; Hill, Jonathan P; Ariga, Katsuhiko

    2013-06-18

    In this article, we propose a novel methodology for the formation of monodisperse regularly sized disks of several nanometer thickness and with diameters of less than 100 nm using Langmuir monolayers as fabrication media. An amphiphilic triimide, tri-n-dodecylmellitic triimide (1), was spread as a monolayer at the air-water interface with a water-soluble macrocyclic oligoamine, 1,4,7,10-tetraazacyclododecane (cyclen), in the subphase. The imide moieties of 1 act as hydrogen bond acceptors and can interact weakly with the secondary amine moieties of cyclen as hydrogen bond donors. The monolayer behavior of 1 was investigated through π-A isotherm measurements and Brewster angle microscopy (BAM). The presence of cyclen in the subphase significantly shifted isotherms and induced the formation of starfish-like microstructures. Transferred monolayers on solid supports were analyzed by reflection absorption FT-IR (FT-IR-RAS) spectroscopy and atomic force microscopy (AFM). The Langmuir monolayer transferred onto freshly cleaved mica by a surface touching (i.e., Langmuir-Schaefer) method contained disk-shaped objects with a defined height of ca. 3 nm and tunable diameter in the tens of nanometers range. Several structural parameters such as the disk height, molecular aggregation numbers in disk units, and 2D disk density per unit surface area are further discussed on the basis of AFM observations together with aggregate structure estimation and thermodynamic calculations. It should be emphasized that these well-defined structures are produced through simple routine procedures such as solution spreading, mechanical compression, and touching a substrate at the surface. The controlled formation of defined nanostructures through easy macroscopic processes should lead to unique approaches for economical, energy-efficient nanofabrication.

  9. Surface modification of polyester fabrics by atmospheric-pressure air/He plasma for color strength and adhesion enhancement

    Science.gov (United States)

    Zhang, Chunming; Zhao, Meihua; Wang, Libing; Qu, Lijun; Men, Yajing

    2017-04-01

    Surface properties of water-based pigmented inks for ink-jet printed polyester fabrics were modified with atmospheric-pressure air/He plasma to improve the color strength and pigment adhesion of the treated surfaces. The influence of various parameters, including the surface morphology, chemical compositions, surface energy and dynamic contact angles of the control and plasma treated samples was studied. Color strength and edge definition were used to evaluate the ink-jet printing performance of fabrics. The change in pigment adhesion to polyester fibers was analyzed by SEM (scanning electron microscopy). AFM (Atomic force microscope) and XPS (X-ray photoelectron spectroscopy) analyses indicated the increase in surface roughness and the oxygen-containing polar groups(Cdbnd O, Csbnd OH and COOH) reinforced the fixation of pigments on the fiber surface. The result from this study suggested that the improved pigment color yield was clearly affected by alteration of pigment adhesion enhanced by plasma surface modification. Polyester fabrics exhibited better surface property and ink-jet printing performance after the air/He mixture plasma treatment comparing with those after air plasma treatment.

  10. Moisture properties of raised 3-thread fleece fabric knitted with different face and fleecy yarns

    Directory of Open Access Journals (Sweden)

    Alaa Arafa Badr

    2016-09-01

    So, in this study, nine three-thread fleece fabrics of different composition materials have been studied, where these knitted fabrics are produced in a special circular knitted machine. The developed fabrics are taken to measure, water vapor permeability “WVP”, gain%, air permeability, drying time, color difference, immersion time and bursting strength. The test results were discussed statistically with single factor ANOVA. From the experimental results, it has been observed that the difference between face and fleecy yarns material was highly significant for the whole fabric in the water vapor permeability, gain%, color difference and immersion time. Three-thread Fleece fabric knitted with Egyptian cotton for the face and fleecy yarns has the maximum bursting strength compared to other samples having Bamboo and Tencel yarns.

  11. Water/oil repellent property of polyester fabrics after supercritical carbon dioxide finishing

    Directory of Open Access Journals (Sweden)

    Xu Yan-Yan

    2015-01-01

    Full Text Available The strong permeability and driving force of supercritical carbon dioxide renders it an ideal medium for fabrics finishing. This paper is to use supercritical carbon dioxide medium with a solution of organic fluorine to fabricate water/oil repellent polyester fabrics. A series of characterization methods including Fourier transform infrared spectrometry, energy dispersive spectrometry, and scanning electron microscopy were carried out to evaluate the fabrics finishing. Fourier transform infrared spectrometry showed that the transmittance peak appeared at 1202.4 and 1147.4 cm-1, indicating the presence of -CF2- group on the surface of polyester fabrics. The results of energy dispersive spectrometer and scanning electron microscopy showed that the fluorine was evenly distributed on the fibers surface. In addition, a series of physical properties were detected, including contact angel, air permeability, breaking strength, and wearing resistance. The average water and hexadecane contact angles were 147.58° and 143.78°, respectively. Compared with the initial fabrics, the treated one has little change in air permeability, while its strength increased greatly. The treated fabrics gained good water/oil repellent properties while keeping good air permeability and improving mechanical property.

  12. Fast fabrication of copper nanowire transparent electrodes by a high intensity pulsed light sintering technique in air.

    Science.gov (United States)

    Ding, Su; Jiu, Jinting; Tian, Yanhong; Sugahara, Tohru; Nagao, Shijo; Suganuma, Katsuaki

    2015-12-14

    Copper nanowire transparent electrodes have received increasing interest due to the low price and nearly equal electrical conductivity compared with other TEs based on silver nanowires and indium tin oxide (ITO). However, a post-treatment at high temperature in an inert atmosphere or a vacuum environment was necessary to improve the conductivity of Cu NW TEs due to the easy oxidation of copper in air atmosphere, which greatly cancelled out the low price advantage of Cu NWs. Here, a high intensity pulsed light technique was introduced to sinter and simultaneously deoxygenate these Cu NWs into a highly conductive network at room temperature in air. The strong light absorption capacity of Cu NWs enabled the welding of the nanowires at contact spots, as well as the removal of the thin layer of residual organic compounds, oxides and hydroxide of copper even in air. The Cu NW TE with a sheet resistance of 22.9 Ohm sq(-1) and a transparency of 81.8% at 550 nm has been successfully fabricated within only 6 milliseconds exposure treatment, which is superior to other films treated at high temperature in a hydrogen atmosphere. The HIPL process was simple, convenient and fast to fabricate easily oxidized Cu NW TEs in large scale in an air atmosphere, which will largely extend the application of cheap Cu NW TEs.

  13. Mechanics of Air-Inflated Drop-Stitch Fabric Panels Subject to Bending Loads

    Science.gov (United States)

    2013-08-15

    materials such as textiles , elastomers, and flexible composites are used for the structure, significant load-carrying capacity per unit weight (or...Drop-Stitch Fabrics Finite Element Analysis Experimental Mechanics Technical Textiles 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF...27 LIST OF ILLUSTRATIONS Figure Page 1 Example of a Drop-Stitch Fabric with Rubber- Laminated

  14. Investigation on the effect of RF air plasma and neem leaf extract treatment on the surface modification and antimicrobial activity of cotton fabric

    Science.gov (United States)

    Vaideki, K.; Jayakumar, S.; Rajendran, R.; Thilagavathi, G.

    2008-02-01

    A thorough investigation on the antimicrobial activity of RF air plasma and azadirachtin (neem leaf extract) treated cotton fabric has been dealt with in this paper. The cotton fabric was given a RF air plasma treatment to improve its hydrophilicity. The process parameters such as electrode gap, time of exposure and RF power have been varied to study their effect in improving the hydrophilicity of the cotton fabric and they were optimized based on the static immersion test results. The neem leaf extract (azadirachtin) was applied on fabric samples to impart antimicrobial activity. The antimicrobial efficacy of the samples have been analysed and compared with the efficacy of the cotton fabric treated with the antimicrobial finish alone. The investigation reveals that the RF air plasma has modified the surface of the fabric, which in turn increased the antimicrobial activity of the fabric when treated with azadirachtin. The surface modification due to RF air plasma treatment has been analysed by comparing the FTIR spectra of the untreated and plasma treated samples. The molecular interaction between the fabric, azadirachtin and citric acid which was used as a cross linking agent to increase the durability of the antimicrobial finish has also been analysed using FTIR spectra.

  15. Thermoelectric fabrics: toward power generating clothing.

    Science.gov (United States)

    Du, Yong; Cai, Kefeng; Chen, Song; Wang, Hongxia; Shen, Shirley Z; Donelson, Richard; Lin, Tong

    2015-03-23

    Herein, we demonstrate that a flexible, air-permeable, thermoelectric (TE) power generator can be prepared by applying a TE polymer (e.g. poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate)) coated commercial fabric and subsequently by linking the coated strips with a conductive connection (e.g. using fine metal wires). The poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) coated fabric shows very stable TE properties from 300 K to 390 K. The fabric device can generate a TE voltage output (V) of 4.3 mV at a temperature difference (ΔT) of 75.2 K. The potential for using fabric TE devices to harvest body temperature energy has been discussed. Fabric-based TE devices may be useful for the development of new power generating clothing and self-powered wearable electronics.

  16. Enhanced photovoltaic performance of planar perovskite solar cells fabricated in ambient air by solvent annealing treatment method

    Science.gov (United States)

    Obiozo Eze, Vincent; Mori, Tatsuo

    2016-12-01

    In this paper, we report on planar perovskite solar cells (PSCs) fabricated by a simple one-step solution process and an antisolvent bath (ASB) method in ambient air. The ASB method enabled the efficient extraction of the precursor solvent and induced the swift crystallization of uniform and highly smooth perovskite films with an average grain size of about 0.34 µm. The morphology and grain growth of the resultant perovskite film were further improved by solvent annealing (SA) under dimethyl sulfoxide (DMSO) vapor atmosphere at 150 °C for 10 min and thus an average power conversion efficiency (PCE) of 15.20% and a maximum efficiency of 16.77% were achieved. This work highlights the importance of solvent annealing for perovskite prepared by a one-step solution process and an ASB method, and offers a facile and attractive way to fabricate high-performance perovskite solar cells.

  17. Extended power-law scaling of heavy-tailed random air-permeability fields in fractured and sedimentary rocks

    Directory of Open Access Journals (Sweden)

    A. Guadagnini

    2012-09-01

    Full Text Available We analyze the scaling behaviors of two field-scale log permeability data sets showing heavy-tailed frequency distributions in three and two spatial dimensions, respectively. One set consists of 1-m scale pneumatic packer test data from six vertical and inclined boreholes spanning a decameters scale block of unsaturated fractured tuffs near Superior, Arizona, the other of pneumatic minipermeameter data measured at a spacing of 15 cm along three horizontal transects on a 21 m long and 6 m high outcrop of the Upper Cretaceous Straight Cliffs Formation, including lower-shoreface bioturbated and cross-bedded sandstone near Escalante, Utah. Order q sample structure functions of each data set scale as a power ξ(q of separation scale or lag, s, over limited ranges of s. A procedure known as extended self-similarity (ESS extends this range to all lags and yields a nonlinear (concave functional relationship between ξ(q and q. Whereas the literature tends to associate extended and nonlinear power-law scaling with multifractals or fractional Laplace motions, we have shown elsewhere that (a ESS of data having a normal frequency distribution is theoretically consistent with (Gaussian truncated (additive, self-affine, monofractal fractional Brownian motion (tfBm, the latter being unique in predicting a breakdown in power-law scaling at small and large lags, and (b nonlinear power-law scaling of data having either normal or heavy-tailed frequency distributions is consistent with samples from sub-Gaussian random fields or processes subordinated to tfBm or truncated fractional Gaussian noise (tfGn, stemming from lack of ergodicity which causes sample moments to scale differently than do their ensemble counterparts. Here we (i demonstrate that the above two data sets are consistent with sub-Gaussian random fields subordinated to tfBm or tfGn and (ii provide maximum likelihood estimates of parameters characterizing the

  18. Design Fabrication And Partial-Analysis Of A 2-Wheeler Prototype That Runs On Compressed Air

    OpenAIRE

    Vinay, P; Srivatsa G R; Venkatesh Datta; Dinesh Kumar A; Ramesha N; Dr. H K Govindaraju

    2015-01-01

    Abstract The primary objective of the project is to create a prototype of a purely air powered motorcycle by retrofitting its internal combustion engine to run on compressed air. Firstly the conventional spark plug was replaced with a solenoid valve. The solenoid valve was initially actuated using a reed switch and magnet duo but then later replaced with an optical crank position sensor circuit due to reasons that include lack of control over the amount of air injected during each stroke and ...

  19. Modelling the Effect of Weave Structure and Fabric Thread Density on Mechanical and Comfort Properties of Woven Fabrics

    Directory of Open Access Journals (Sweden)

    Maqsood Muhammad

    2016-09-01

    Full Text Available The paper investigates the effects of weave structure and fabric thread density on the comfort and mechanical properties of various test fabrics woven from polyester/cotton yarns. Three different weave structures, that is, 1/1 plain, 2/1 twill and 3/1 twill, and three different fabric densities were taken as input variables whereas air permeability, overall moisture management capacity, tensile strength and tear strength of fabrics were taken as response variables and a comparison is made of the effect of weave structure and fabric density on the response variables. The results of fabric samples were analysed in Minitab statistical software. The coefficients of determinations (R-sq values of the regression equations show a good predictive ability of the developed statistical models. The findings of the study may be helpful in deciding appropriate manufacturing specifications of woven fabrics to attain specific comfort and mechanical properties.

  20. Notional Permeability

    OpenAIRE

    Kik, R.; Van den Bos, J.P.; Maertens, J.; Verhagen, H.J.; van der Meer, J W

    2012-01-01

    Different layer design of a rock slope and under layers has a large effect on the strengths on the rock slope itself. In the stability formula developed of VAN DER MEER [1988] this effect is represented by the term Notional Permeability with symbol P. A more open, or permeable, structure underneath the armour layer has the ability to dissipate more wave energy and therefore requires less weight of the armour layer. The influence of this parameter is thus very important in economic sense. Up u...

  1. Fabrication of high performance Gd-Ba-Cu-O single grains in air using a practical melt processing technique

    Energy Technology Data Exchange (ETDEWEB)

    Cardwell, D.A., E-mail: dc135@cam.ac.u [Engineering Department, Trumpington Street, University of Cambridge, CB2 1PZ (United Kingdom); Shi, Y. [Engineering Department, Trumpington Street, University of Cambridge, CB2 1PZ (United Kingdom); Hari Babu, N. [Engineering Department, Trumpington Street, University of Cambridge, CB2 1PZ (United Kingdom); BCAST, Brunel University, West London UB8 3PH (United Kingdom); Iida, K. [Engineering Department, Trumpington Street, University of Cambridge, CB2 1PZ (United Kingdom)

    2009-10-15

    A practical processing route for the fabrication of LRE-Ba-Cu-O single grain superconductors has been developed at the University of Cambridge based on a generic, Mg-doped Nd-123 melt textured seed and suppression of the formation of the solid solution phase in air by enriching the precursors with higher Ba concentration. The processing of high performance Gd-Ba-Cu-O single grains using this processing route is described. The Mg-doped generic seed crystal has been used effectively to promote heterogeneous nucleation via a cold-seeding process. The Gd/Ba solid solution has been suppressed by enriching Gd-Ba-Cu-O precursor powders with two different Ba-rich compositions. This involved adding BaO{sub 2} and GdBa{sub 6}Cu{sub 3}O{sub y} (Gd-163) (a novel Ba-rich second phase) to the precursor powders, respectively. The Gd-163 phase has been observed not only to suppress formation of the solid solution phase, but also to promote increased heterogeneous grain size. A detailed further study has been carried out with an initial aim of optimizing the BaO{sub 2} and Gd-163 phase content of the precursor composition to produce a single grain almost free of solid solution. Based on the optimized parameters, large single grain Gd-Ba-Cu-O superconductors have been fabricated in an air atmosphere and demonstrated to exhibit record trapped magnetic fields for this material melt processed in air in relatively small single grain samples. The trapped fields of samples produced in air atmosphere are at least comparable to those processed under reduced oxygen partial pressure.

  2. Porosity Prediction of Plain Weft Knitted Fabrics

    Directory of Open Access Journals (Sweden)

    Muhammad Owais Raza Siddiqui

    2014-12-01

    Full Text Available Wearing comfort of clothing is dependent on air permeability, moisture absorbency and wicking properties of fabric, which are related to the porosity of fabric. In this work, a plug-in is developed using Python script and incorporated in Abaqus/CAE for the prediction of porosity of plain weft knitted fabrics. The Plug-in is able to automatically generate 3D solid and multifilament weft knitted fabric models and accurately determine the porosity of fabrics in two steps. In this work, plain weft knitted fabrics made of monofilament, multifilament and spun yarn made of staple fibers were used to evaluate the effectiveness of the developed plug-in. In the case of staple fiber yarn, intra yarn porosity was considered in the calculation of porosity. The first step is to develop a 3D geometrical model of plain weft knitted fabric and the second step is to calculate the porosity of the fabric by using the geometrical parameter of 3D weft knitted fabric model generated in step one. The predicted porosity of plain weft knitted fabric is extracted in the second step and is displayed in the message area. The predicted results obtained from the plug-in have been compared with the experimental results obtained from previously developed models; they agreed well.

  3. Herbal Extract Incorporated Nanofiber Fabricated by an Electrospinning Technique and its Application to Antimicrobial Air Filtration.

    Science.gov (United States)

    Choi, Jeongan; Yang, Byeong Joon; Bae, Gwi-Nam; Jung, Jae Hee

    2015-11-18

    Recently, with the increased attention to indoor air quality, antimicrobial air filtration techniques have been studied widely to inactivate hazardous airborne microorganisms effectively. In this study, we demonstrate herbal extract incorporated (HEI) nanofibers synthesized by an electrospinning technique and their application to antimicrobial air filtration. As an antimicrobial herbal material, an ethanolic extract of Sophora flavescens, which exhibits great antibacterial activity against pathogens, was mixed with the polymer solution for the electrospinning process. We measured various characteristics of the synthesized HEI nanofibers, such as fiber morphology, fiber size distribution, and thermal stability. For application of the electrospun HEI nanofibers, we made highly effective air filters with 99.99% filtration efficiency and 99.98% antimicrobial activity against Staphylococcus epidermidis. The pressure drop across the HEI nanofiber air filter was 4.75 mmH2O at a face air velocity of 1.79 cm/s. These results will facilitate the implementation of electrospun HEI nanofiber techniques to control air quality and protect against hazardous airborne microorganisms.

  4. Fabrication and Performance of All-Solid-State Li-Air Battery with SWCNTs/LAGP Cathode.

    Science.gov (United States)

    Liu, Yijie; Li, Bojie; Kitaura, Hirokazu; Zhang, Xueping; Han, Min; He, Ping; Zhou, Haoshen

    2015-08-12

    The all-solid-state Li-air battery has been fabricated, which is constructed by a lithium foil anode, a NASICON-type solid state electrolyte Li1+xAlyGe2-y(PO4)3 (LAGP) and single-walled carbon nanotubes (SWCNTs)/LAGP nanoparticles composite as air electrode. Its electrochemical performance was investigated in air atmosphere. Particularly, this battery exhibited a larger capacity about 2800 mAh g(-1) for the first cycle, while comparatively the battery with multiwalled carbon nanotubes (MWCNTs)/LAGP as cathode had a capacity of only about 1700 mAh g(-1). Also, the battery with SWCNTs/LAGP showed improved cycling performance with a reversible capacity of 1000 mAh g(-1) at a current density of 200 mA g(-1). Our result demonstrated that the all-solid-state Li-air battery with SWCNTs/LAGP as cathode catalyst has a considerable potential for practical application.

  5. Design Fabrication And Partial-Analysis Of A 2-Wheeler Prototype That Runs On Compressed Air

    Directory of Open Access Journals (Sweden)

    P Vinay

    2015-08-01

    Full Text Available Abstract The primary objective of the project is to create a prototype of a purely air powered motorcycle by retrofitting its internal combustion engine to run on compressed air. Firstly the conventional spark plug was replaced with a solenoid valve. The solenoid valve was initially actuated using a reed switch and magnet duo but then later replaced with an optical crank position sensor circuit due to reasons that include lack of control over the amount of air injected during each stroke and also for more precise control over the opening and closing of the valve. The torque brake power indicated power air consumption rate of the engine under load are calculated. Separate mounts for the modified engine and the cylindrical storage unit are designed and analysed using Catia v4. Also possible ways of future scope of the prototype are mentioned.

  6. Effect of air plasma treatment on the dyeing of Tencel fabric with C.I. Reactive Black 5

    Science.gov (United States)

    Zhang, L. S.; Liu, H. L.; Yu, W. D.

    2015-02-01

    The Tencel fabrics were treated by the atmospheric pressure plasma with air for different length of time and dyed with the C.I. Reactive Black 5 at 1%, 5% and 10% o.m.f. The effect of the prolonged plasma treatment time was characterized by both the weight loss and the whiteness index analyses, which implied that with the increase of the plasma treatment time, the treated fabrics were lighter and yellower than the untreated ones. The contact angle decreased dramatically from 139° to instantly spread. The results of SEM showed that, with the prolonged treatment time, more significant crater-like surface morphology on the fiber of Tencel samples was formed. Compared with untreated samples, the values of dye bath exhaustion and total fixation effect were higher. But they did not increase with the prolonged plasma treatment time. With the prolonged storage time after the plasma treatment, the result to ageing effect indicated that the values of dye bath exhaustion and total fixation effect reduced. The Integ values for characterizing the coloring effect were evaluated by the CIE system of color measurement. In most cases, the Integ values reached the highest ones when the plasma treatment time was 10 or 20 min. When the concentration of the dye bath was low (at 1% o.m.f.), the longer plasma treatment time was, the higher the Integ value was. However, if the fabrics after plasma treatment were stored for 21 days, the longer plasma treatment time did not cause the larger Integ value. When the concentration was 1%, the Integ value increased with the weight loss increasing, which was different from the values of fabrics with 5% and 10% concentration. If the dyeing concentration was low, the fixation had a more significant effect on the color fastness to wet rubbing; in contrast, if the dyeing concentration was high, the surface roughness had a more important effect on it.

  7. Fabrication of a polyvinylidene difluoride fiber with a metal core and its application as directional air flow sensor

    Science.gov (United States)

    Bian, Yixiang; Liu, Rongrong; Hui, Shen

    2016-09-01

    We fabricated a sensitive air flow detector that mimic the sensing mechanism found at the tail of some insects. [see Y. Yang, A. Klein, H. Bleckmann and C. Liu, Appl. Phys. Lett. 99(2) (2011); J. J. Heys, T. Gedeon, B. C. Knott and Y. Kim, J. Biomech. 41(5), 977 (2008); J. Tao and X. Yu, Smart Mat. Struct. 21(11) (2012)]. Our bionic airflow sensor uses a polyvinylidene difluoride (PVDF) microfiber with a molybdenum core which we produced with the hot extrusion tensile method. The surface of the fiber is partially coated with conductive silver adhesive that serve as surface electrodes. A third electrode, the metal core is used to polarize polyvinylidene difluoride (PVDF) under the surface electrodes. The cantilever beam structure of the prepared symmetric electrodes of metal core piezoelectric fiber (SMPF) is used as the artificial hair airflow sensor. The surface electrodes are used to measure output voltage. Our theoretical and experimental results show that the SMPF responds fast to air flow changes, the output charge has an exponential correlation with airflow velocity and a cosine relation with the direction of airflow. Our bionic airflow sensor with directional sensing ability can also measure air flow amplitude. [see H. Droogendijk, R. G. P. Sanders and G. J. M. Krijnen, New J. Phys. 15 (2013)]. By using two surface electrodes, our sensing circuit further improves sensitivity.

  8. Perspective: Maintaining surface-phase purity is key to efficient open air fabricated cuprous oxide solar cells

    Directory of Open Access Journals (Sweden)

    Robert L. Z. Hoye

    2015-02-01

    Full Text Available Electrochemically deposited Cu2O solar cells are receiving growing attention owing to a recent doubling in efficiency. This was enabled by the controlled chemical environment used in depositing doped ZnO layers by atomic layer deposition, which is not well suited to large-scale industrial production. While open air fabrication with atmospheric pressure spatial atomic layer deposition overcomes this limitation, we find that this approach is limited by an inability to remove the detrimental CuO layer that forms on the Cu2O surface. Herein, we propose strategies for achieving efficiencies in atmospherically processed cells that are equivalent to the high values achieved in vacuum processed cells.

  9. High performance air electrode for solid oxide regenerative fuel cells fabricated by infiltration of nano-catalysts

    Science.gov (United States)

    Lee, Sung-il; Kim, Jeonghee; Son, Ji-Won; Lee, Jong-Ho; Kim, Byung-Kook; Je, Hae-June; Lee, Hae-Weon; Song, Huesup; Yoon, Kyung Joong

    2014-03-01

    A high performance air electrode fabricated by infiltration of highly active nano-catalysts into a porous scaffold is demonstrated for high-temperature solid oxide regenerative fuel cells (SORFCs). The nitrate precursor solution for Sm0.5Sr0.5CoO3 (SSC) catalyst is impregnated into a porous La0.6Sr0.4Co0.2Fe0.8O3 (LSCF)-gadolinia-doped ceria (GDC) composite backbone, and extremely fine SSC nano-particles are uniformly synthesized by in-situ crystallization at the initial stage of SORFC operation via homogeneous nucleation induced by urea decomposition. The SSC nano-catalysts are in the size range of 40-80 nm and stable against coarsening upon the SORFC operation at 750 °C. The electrochemical performance is significantly improved by incorporation of SSC nano-catalysts in both power generation and hydrogen production modes. Systematic analysis on the impedance spectra reveals that the surface modification of the air electrode with nano-catalysts remarkably accelerates the chemical surface exchange reactions for both O2 reduction and O2- oxidation, which are the major limiting processes for SORFC performance.

  10. Modifying of Cotton Fabric Surface with Nano-ZnO Multilayer Films by Layer-by-Layer Deposition Method

    Directory of Open Access Journals (Sweden)

    Sarıışık Merih

    2010-01-01

    Full Text Available Abstract ZnO nanoparticle–based multilayer nanocomposite films were fabricated on cationized woven cotton fabrics via layer-by-layer molecular self-assembly technique. For cationic surface charge, cotton fabrics were pretreated with 2,3-epoxypropyltrimethylammonium chloride (EP3MAC by pad-batch method. XPS and SEM were used to examine the deposited nano-ZnO multilayer films on the cotton fabrics. The nano-ZnO films deposited on cotton fabrics exhibited excellent antimicrobial activity against Staphylococcus aureus bacteria. The results also showed that the coated fabrics with nano-ZnO multilayer films enhanced the protection of cotton fabrics from UV radiation. Physical tests (tensile strength of weft and warp yarns, air permeability and whiteness values were performed on the fabrics before and after the treatment with ZnO nanoparticles to evaluate the effect of layer-by-layer (LbL process on cotton fabrics properties.

  11. Design, fabrication, and characterization of multifunctional wings to harvest solar energy in flapping wing air vehicles

    Science.gov (United States)

    Perez-Rosado, Ariel; Gehlhar, Rachel D.; Nolen, Savannah; Gupta, Satyandra K.; Bruck, Hugh A.

    2015-06-01

    Currently, flapping wing unmanned aerial vehicles (a.k.a., ornithopters or robotic birds) sustain very short duration flight due to limited on-board energy storage capacity. Therefore, energy harvesting elements, such as flexible solar cells, need to be used as materials in critical components, such as wing structures, to increase operational performance. In this paper, we describe a layered fabrication method that was developed for realizing multifunctional composite wings for a unique robotic bird we developed, known as Robo Raven, by creating compliant wing structure from flexible solar cells. The deformed wing shape and aerodynamic lift/thrust loads were characterized throughout the flapping cycle to understand wing mechanics. A multifunctional performance analysis was developed to understand how integration of solar cells into the wings influences flight performance under two different operating conditions: (1) directly powering wings to increase operation time, and (2) recharging batteries to eliminate need for external charging sources. The experimental data is then used in the analysis to identify a performance index for assessing benefits of multifunctional compliant wing structures. The resulting platform, Robo Raven III, was the first demonstration of a robotic bird that flew using energy harvested from solar cells. We developed three different versions of the wing design to validate the multifunctional performance analysis. It was also determined that residual thrust correlated to shear deformation of the wing induced by torsional twist, while biaxial strain related to change in aerodynamic shape correlated to lift. It was also found that shear deformation of the solar cells induced changes in power output directly correlating to thrust generation associated with torsional deformation. Thus, it was determined that multifunctional solar cell wings may be capable of three functions: (1) lightweight and flexible structure to generate aerodynamic forces, (2

  12. Geometrical Modeling of Woven Fabrics Weavability-Limit New Relationships

    Directory of Open Access Journals (Sweden)

    Dalal Mohamed

    2017-03-01

    Full Text Available The weavability limit and tightness for 2D and 3D woven fabrics is an important factor and depends on many geometric parameters. Based on a comprehensive review of the literature on textile fabric construction and property, and related research on fabric geometry, a study of the weavability limit and tightness relationships of 2D and 3D woven fabrics was undertaken. Experiments were conducted on a representative number of polyester and cotton woven fabrics which have been woven in our workshop, using three machines endowed with different insertion systems (rapier, projectiles and air jet. Afterwards, these woven fabrics have been analyzed in the laboratory to determine their physical and mechanical characteristics using air permeability-meter and KES-F KAWABATA Evaluation System for Fabrics. In this study, the current Booten’s weavability limit and tightness relationships based on Ashenhurst’s, Peirce’s, Love’s, Russell’s, Galuszynskl’s theory and maximum-weavability is reviewed and modified as new relationships to expand their use to general cases (2D and 3D woven fabrics, all fiber materiel, all yarns etc…. The theoretical relationships were examined and found to agree with experimental results. It was concluded that the weavability limit and tightness relationships are useful tools for weavers in predicting whether a proposed fabric construction was weavable and also in predicting and explaining their physical and mechanical properties.

  13. Desalination of simulated seawater by purge-air pervaporation using an innovative fabricated membrane.

    Science.gov (United States)

    Naim, Mona; Elewa, Mahmoud; El-Shafei, Ahmed; Moneer, Abeer

    2015-01-01

    An innovative polymeric membrane has been invented, which presents a breakthrough in the field of desalination membranes. It can desalinate simulated seawater of exceptionally high concentration to produce a high flux of potable water with over 99.7% salt rejection (%SR) in a once-through purge-air pervaporation (PV) process. A set-up was constructed for conducting the desalination experiments and the effect of initial salt solution concentration (Ci) and pervaporation temperature (Tpv) on the water flux (J), %SR, separation factor, and pervaporation separation index were determined. The membrane was prepared by the phase-inversion technique, of a specially formulated casting solution consisting of five ingredients, after which the membrane was subjected to a post-treatment by which certain properties were conferred. The results confirmed that the salinity of the pervaporate was independent of Ci (all %SR above 99.7). The best result was at Tpv=70 °C, where J varied from 5.97 to 3.45 l/m2 h for Ci=40-140 g NaCl/l, respectively. The membrane morphology was confirmed to be asymmetric. The contact angle was immeasurable, indicating the membrane to be super-hydrophilic. Activation energies computed using Arrhenius law were, under all conditions investigated, less than 20 kJ/mol K.

  14. Design and Fabrication of Air-core Inductors for Power Conversion

    DEFF Research Database (Denmark)

    Lê Thanh, Hoà; Mizushima, Io; Tang, Peter Torben

    Microelectromechanical systems (MEMS) inductors are used for e.g. RF MEMS and microelectronics. A new application is for power electronics in switched mode power supplies (SMPS). High-performance power inductors, which can be combined with integrated circuits (IC), are required for future power s...... inductors that are impossible to make by wire-winding technology. As all process temperatures are kept below 200 ºC, the inductors can be integrated into CMOS wafers by MEMS post processing.......Microelectromechanical systems (MEMS) inductors are used for e.g. RF MEMS and microelectronics. A new application is for power electronics in switched mode power supplies (SMPS). High-performance power inductors, which can be combined with integrated circuits (IC), are required for future power...... supply on chip (PwrSoC) [1]. Examples of PwrSoC applications are power adaptors for LED illumination and the “Internet of Things”. We report an air-core MEMS inductor. Our process is scalable and universal for making inductors with versatile geometries e.g. spiral, solenoid, toroid, and advanced...

  15. Factors affecting the microstructural stability and durability of thermal barrier coatings fabricated by air plasma spraying

    Energy Technology Data Exchange (ETDEWEB)

    Helminiak, M.A.; Yanar, N.M.; Pettit, F.S.; Meier, G.H. [National Energy Technology Laboratory, Pittsburgh, PA 15236 (United States); Department of Mechanical Engineering and Materials Science, University of Pittsburgh, 636 Benedum Hall, 3700 O& #x27; Hara Street, Pittsburgh, PA 15261 (United States); Taylor, T.A. [Praxair Surface Technologies, Inc., 1400 Polco Street, Indianapolis, IN 46224 (United States)

    2012-10-15

    The high-temperature behavior of high-purity, low-density (HP-LD) air plasma sprayed (APS) thermal barrier coatings (TBCs) with NiCoCrAlY bond coats deposited by argon-shrouded plasma spraying is described. The high purity yttria-stabilized zirconia resulted in top coats which are highly resistant to sintering and transformation from the metastable tetragonal phase to the equilibrium mixture of monoclinic and cubic phases. The thermal conductivity of the as-processed TBC is low but increases during high temperature exposure even before densification occurs. The porous topcoat microstructure also resulted in good spallation resistance during thermal cycling. The actual failure mechanisms of the APS coatings were found to depend on topcoat thickness, topcoat density, and the thermal cycle frequency. The failure mechanisms are described and the durability of the HP-LD coatings is compared with that of state-of-the-art electron beam physical vapor deposition TBCs. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Permeability and air voids of cold recycled mixtures with asphalt emulsion%乳化沥青冷再生混合料的透水性与空隙特征

    Institute of Scientific and Technical Information of China (English)

    高磊; 倪富健; 罗海龙; 杨美坤

    2015-01-01

    为了研究乳化沥青冷再生混合料的透水性与空隙特征之间关系,通过测定渗透系数来评价其透水性,并利用工业CT扫描观测其内部细观空隙结构。根据乳化沥青冷再生混合料养生过程中空隙率的变化,探究水泥和水对其空隙形成的影响。结果发现,乳化沥青冷再生混合料在较高的空隙率下具有相对较低的透水性;其平均空隙尺寸略小于同级配的热拌沥青混合料,且大空隙较少,小空隙较多;乳化沥青冷再生混合料的空隙由压实空隙和养生空隙构成,水分的蒸发和水泥用量对养生空隙的形成具有显著的影响,随着水分的蒸发和水泥的水化,乳化沥青冷再生混合料内部形成了许多养生空隙;乳化沥青冷再生混合料的空隙尺寸以及分布特征是造成其低透水性的重要因素。%The relationship between the permeability and air voids of cold recycled mixtures with as-phalt emulsion was studied.The hydraulic conductivity was used to evaluate the permeability and the CT( computed tomography) scanning was applied to find the characteristics of air voids.The effects of Portland cement and water were evaluated according to the change of air void content.The results show that the cold recycled mixture has a relatively low permeability under a relatively high air void content.The average air void size of cold recycled mixture is a little smaller than that of hot mix as-phalt mixture, with less air voids in large size and more air voids in small size.The air voids of cold recycled mixture are developed during compaction and curing time.In the process of curing, the e-vaporation of water and hydration of cement affect the air void content significantly leading to the formation of more air voids.The size and distribution of air voids are important factors that contrib-ute to the relatively low permeability of cold recycled mixture.

  17. A multilayer structure to reduce the permeability of the tanks; Structure multicouche pour reduire la permeabilite des reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2004-09-01

    Atofina has launched in 2003, in collaboration with TI Automotive, a new multilayer structure for the fabrication of fuels tanks conformable to the legislation 'Partial Zero Emission Vehicle'. Composed of 6 layers, this multilayer has the advantage to present a very weak permeability reducing considerably the releases of gasoline vapors at the exterior of the fuel system, abating consequently the air pollution. (O.M.)

  18. Filtration Performances of Fabrics for Recirculated Air from Air Conditioning System in Manufacturing Department%卷烟车间空调回风过滤用毛绒滤料的过滤性能

    Institute of Scientific and Technical Information of China (English)

    杨磊; 范晓伟; 张勍; 赵航; 宋高举; 苗芊; 程爱霞; 董富文

    2014-01-01

    In order to assess the cleaning effects of new flocked filter fabrics on the recirculated air from air conditioning system in cigarette manufacturing department, two fabrics of different types were tested and their influencing factors were analyzed. The results showed that: 1) The filtration efficiency of pile fabric was influenced by air velocity more significantly with a standard deviation of filtration efficiency distribution of 21.4%. The filtration efficiency of nap fabric was less affected by air velocity fluctuation, and its highest standard deviation of filtration efficiency distribution was 5.2%. 2) Dust concentration did not affect the running resistance of the two filtration fabrics significantly. 3) The average dust retentivities of nap fabric and pile fabric were 359.2 and 707.1 g/m2, respectively. Though lower in dust retentivity, nap fabric was considered to be more applicable due to its advantages of lower filtration resistance and higher stabilities of filtration efficiency and filtration resistance when air velocity or dust concentration fluctuated.%为研究新型毛绒滤料应用于卷烟车间空调系统过滤段时,对空调回风的净化效果,分析了不同型号毛绒滤料对空调回风粉尘的过滤特性及其影响因素。结果表明:①长毛绒滤料过滤效率受过滤风速的影响较为显著,过滤效率分布的标准差高达21.4%;过滤风速变化时,短毛绒滤料的过滤效率较稳定,过滤效率分布的标准差最高为5.2%。②粉尘浓度对两种毛绒滤料的运行阻力的影响均不明显。③短毛绒滤料平均容尘量359.2 g/m2,小于长毛绒滤料平均容尘量707.1 g/m2。尽管短毛绒滤料容尘量较小,但其过滤阻力、过滤风速变化时过滤效率的稳定性、粉尘浓度变化时过滤阻力的稳定性等性能指标均优于长毛绒滤料。

  19. N-Halamine-modified antimicrobial polypropylene nonwoven fabrics for use against airborne bacteria.

    Science.gov (United States)

    Demir, Buket; Cerkez, Idris; Worley, S D; Broughton, R M; Huang, Tung-Shi

    2015-01-28

    Disinfecting, nonbleaching compound 1-chloro-2,2,5,5-tetramethyl-4-imidazolidinone (MC) was uniformly coated onto polypropylene melt-blown nonwoven fabrics having basis-weights of 22 and 50 g/m(2) in order to impart antimicrobial properties via a pad-dry technique. The antimicrobial efficacies of the tested fabrics loaded with MC compound were evaluated against bioaerosols of Staphylococcus aureus and Escherichia coli O157:H7 utilizing a colony counting method. It was determined that both types of coated fabrics exhibited superior antimicrobial efficacy upon exposure to aerosol generation for 3 h. The effect of the coating on air permeability was found to be minimal. Samples were stable for a 6 month time period when they were stored in darkness. However, when the fabrics were exposed to fluorescent light, partial chlorine loss was observed. The MC-coated fabrics exhibited great potential for use in protective face masks and air filters to combat airborne pathogens.

  20. Production of Engineered Fabrics Using Artificial Neural Network-Genetic Algorithm Hybrid Model

    Science.gov (United States)

    Mitra, Ashis; Majumdar, Prabal Kumar; Banerjee, Debamalya

    2015-10-01

    The process of fabric engineering which is generally practised in most of the textile mills is very complicated, repetitive, tedious and time consuming. To eliminate this trial and error approach, a new approach of fabric engineering has been attempted in this work. Data sets of construction parameters [comprising of ends per inch, picks per inch, warp count and weft count] and three fabric properties (namely drape coefficient, air permeability and thermal resistance) of 25 handloom cotton fabrics have been used. The weights and biases of three artificial neural network (ANN) models developed for the prediction of drape coefficient, air permeability and thermal resistance were used to formulate the fitness or objective function and constraints of the optimization problem. The optimization problem was solved using genetic algorithm (GA). In both the fabrics which were attempted for engineering, the target and simulated fabric properties were very close. The GA was able to search the optimum set of fabric construction parameters with reasonably good accuracy except in case of EPI. However, the overall result is encouraging and can be improved further by using larger data sets of handloom fabrics by hybrid ANN-GA model.

  1. An isopropanol-assisted fabrication strategy of pinhole-free perovskite films in air for efficient and stable planar perovskite solar cells

    Science.gov (United States)

    Ren, Ziqiu; Zhu, Menghua; Li, Xin; Dong, Cunku

    2017-09-01

    As a promising photovoltaic device, perovskite solar cells have attracted numerous attention in recent years, where forming a compact and pinhole-free perovskite film in air is of great importance. Herein, we evaluate highly efficient and air stable planar perovskite solar cells in air (relative humidity over 50%) with the modified two-step sequential deposition method by adjusting the CH3NH3I (MAI) concentrations and regulating the crystallization process of the perovskite film. The optimum MAI concentration is 60 mg mL-1 in isopropanol. With a planar structure of FTO/TiO2/MAPbI3/spiro-OMeTAD/Au, the efficient devices composed of compact and pinhole-free perovskite films are constructed in air, achieving a high efficiency of up to 15.10% and maintaining over 80% after 20 days storing without any encapsulation in air. With a facile fabrication process and high photovoltaic performance, this work represents a promising method for fabricating low-cost, highly efficient and stable photovoltaic device.

  2. A Negative Permeability Material at Red Light

    DEFF Research Database (Denmark)

    Yuan, Hsiao-Kuan; Chettiar, Uday K.; Cai, Wenshan;

    2007-01-01

    A negative permeability in a periodic array of pairs of thin silver strips is demonstrated experimentally for two distinct samples. The effect of the strip surface roughness on negative permeability is evaluated. The first sample, Sample A, is fabricated of thinner strips with a root mean square...... roughness of 7 nm, while Sample B is made of thicker strips with 3-nm roughness. The real part of permeability, μ ′ , is −1 at a wavelength of 770 nm in Sample A and −1.7 at 725 nm in Sample B. Relative to prototypes simulated with ideal strips, larger strip roughness acts to decrease μ ′ by a factor of 7...

  3. Gas and Water Permeability of Concrete

    Energy Technology Data Exchange (ETDEWEB)

    Villar, M. V.; Martin, P. L.; Romero, F. J.; Gutierrez-Rodirgo, V.; Barcala, J. M.

    2012-11-01

    The gas pressure of concrete samples was measured in an unsteady-state equipment working under low injection pressures and in a newly fine tuned steady-state setup working under different pressures. These measurements allowed the estimation of the intrinsic and relative gas permeability of the concrete and of the effect of boundary conditions on them. Permeability decreased with water content, but it was also greatly affected by the hydraulic history of concrete, i.e. if it had been previously dried or wetted. In particular, and for a given degree of saturation, the gas permeability of concrete previously saturated was lower than if the concrete had been just air dried or saturated after air drying. In any case, the gas permeability was about two orders of magnitude higher than the liquid water permeability (10-16 vs. 10-18 m2), probably due to the chemical reactions taking place during saturation (carbonation). The relative gas permeability of concrete increased sharply for water degrees of saturation smaller than 50%. The boundary conditions also affected the gas permeability, which seemed to be mostly conditioned by the back pressure and the confining pressure, increasing as the former increased and decreasing as the latter increased, i.e. decreasing as the effective pressure increased. Overall the increase of pressure head or injection pressure implied a decrease in gas permeability. External,microcracking during air-drying could not be ruled out as responsible for the decrease of permeability with confining pressure. The apparent permeability obtained applying the Klinkenberg method for a given effective pressure was only slightly smaller than the average of all the values measured for the same confining pressure range. For this reason it is considered that the Klinkenberg effect was not relevant in the range of pressures applied. (Author) 37 refs.

  4. Improvement in Tensile Strength of Bamboo Knitted Fabric by Sol-Gel Coating

    Directory of Open Access Journals (Sweden)

    Awais Khatri

    2013-07-01

    Full Text Available Textiles made of bamboo regenerated fibre are reported to have lower tensile strength than the other cellulosic fibres, due to high porosity of the fibre. This paper was aimed to modify the bamboo knitted fabric by the sol-gel coating to improve the tensile strength with minimum effect on its inherent morphology and ultimate relevant properties such as good absorbency and air permeability. The paddry- bake process was employed for the coating where tetraethyl-orthosilicate and nano-titanium-dioxide were used as the active ingredients. The treated fabrics were tested for the tensile behaviour in terms of breaking strength and elongation and the sol-gel process recipe and parameters were optimised. The absorbency, air-permeability and washing durability of the coating were also tested for the optimised process. Results showed the increase in tensile strength of the fabric by sol-gel coating, whereas absorbency and air-permeability were almost unaffected. The coating results were unaffected even after a washing treatment (equivalent to 5 industrial washings. Additionally, the wrinkle recovery angle of the coated fabric was also tested and found improved.

  5. The Effect of Fibre Blend on Comfort Characteristics of Elastic Knitted Fabrics Used for Pressure Garments

    Science.gov (United States)

    Bera, M.; Chattopadhay, R.; Gupta, D.

    2014-04-01

    Comfort characteristics of pressure garments are very important issue as these garments are recommended to wear for 23 h a day to recover from venous problem, scar maturation, orthopedic problems, post surgery, post pregnancy and many other problems. The patients mostly stop using such kind of medical devices because of itching, perspiration and other comfort relate problems. Mostly nylon, polyester and cotton fibres are used in the fabrics. Nylon, polyester are used for strength whereas cotton is used for good comfort related properties. It may be possible to get some certain type of strength and comfort property together by using both types of fibre. Less information is available in this aspect. In this paper, fabric samples were prepared in knit construction by varying the nylon and cotton blend percentage. Comfort properties in terms of air permeability, thermal property, water vapor permeability, surface friction behavior and wicking properties have been studied extensively. The results showed that, the fibre blend percentage did not have any influence on pressure generation. Air permeability and thermal properties were also not affected. However, water vapor permeability and wicking behavior vary significantly. Increase in nylon percentage increases both the water vapor permeability and wicking. It can be thus concluded that, manufacturers can choose fibre blend percentage according to the requirement.

  6. Comparison of different test methods for the measurement of fabric or garment moisture transfer properties

    Science.gov (United States)

    Kar, F.; Fan, J.; Yu, W.

    2007-07-01

    Several test methods exist for determining the water vapour permeability or resistance of textile fabrics or garments. The differences and interrelationships between these methods are not always clear, which presents a problem in comparing results from different test methods. This study is aimed at investigating the relationships between the test results from four typical test methods, including the moisture transmission test (Model CS-141), ASTM E96 cup method, sweating guarded hot plate method (ISO11092) and the sweating fabric manikin (Walter). For the range of air permeable knitted fabrics tested, it was found that good interrelationships exist between the results from the four types of test methods, although some discrepancies exist between different tests due to differences in testing conditions. Test results from different moisture transfer test methods can therefore be convertible with due consideration.

  7. Degradation of permeability resistance of high strength concrete after combustion

    Institute of Scientific and Technical Information of China (English)

    Min LI; Hongtao KAO; Chunxiang QIAN

    2008-01-01

    To evaluate the remaining durability of con-crete materials after combustion, the permeability of high strength concrete (HSC) after combustion was studied. The transport behavior of chloride ion, water and air in concrete after combustion and the effect of temperature, strength grade, and aggregation on the permeability of HSC after combustion are investigated by chloride ion permeability coefficient (Dc), water permeability coef-ficient (Dw) and air permeability coefficient (Da). The experiment results show that all three permeability coeffi-cients commendably reflect changes of permeability. The permeability coefficient increases with the evaluation tem-perature. After the same temperature, the permeability coefficient of HSC is lower than that of normal strength concrete (NSC). However, the degree of degradation of permeability coefficient of HSC is greater than that of NSC. The permeability resistance of HSC containing limestone is better than that of HSC containing basalt. Combining changes of compressive strength and per-meability, the remaining durability of concrete materials after combustion is appropriately evaluated.

  8. Relations Between Permeability and Structure of Wood

    Institute of Scientific and Technical Information of China (English)

    Bao Fucheng; Zhao Youke; Lü Jianxiong

    2003-01-01

    The permeability and the structure of heartwood and sapwood of the solvent-exchange dried and the air-dried green-wood of Chinese-fir (Cunninghamia lanceolata (Lamb.) Hook.) and masson pine (Pinus massoniana Lamb.) were measured inorder to study the relations between the permeability and the structure. The results showed that the permeability of sapwood of boththe air-dried and the solvent-exchange dried wood was higher than that of heartwood, and the permeability of the solvent-exchangeddried heartwood and sapwood was higher than that of the air-dried. A higher permeability of wood was attributed to, on the one hand,a bigger number of flow path per unit area of the wood perpendicular to the flow direction resulted from a bigger number ofunaspirated pits per unit area and a bigger number of effective pit openings per membrane, and on the other hand, a smaller numberof tracheid in series connection per unit length parallel to flow direction resulted from a longer tracheid length and an effectivetracheid length for permeability.

  9. Development of Multifunctional Anti Aging Military Raincoat Fabric by Using Fitting Technique

    Directory of Open Access Journals (Sweden)

    Chen Chun Xia

    2016-01-01

    Full Text Available Use Woodland camouflage paint Oxford fabric as base cloth, first the light pressure processing was used on the fabric, and then use polyurethane which has high water vapor permeability performance and other various additives as face glue and Bottom glue, the fabric was compounded a thin macromolecule hydrophilic polymer PU film, the fabric was water allocation processed after stripping, At last the fabric will have high performance of the windproof, waterproof and moisture permeability. After testing, the performance index of the fabric are: the smoothness appearance of fabrics after cleaning≥grade4.0; hydrostatic pressure≥10000mmH2O, after 20 times washing≥5000mmH2O, The surface water repellency level≥grade 4.0,after 20 times washing≥grade3.0, water vapor permeability≥3500g/(m2·24h; Electrostatic charge density≥2.5uc/m2; humid air accelerated aging grade≥4.0.Test data shows that the designed functional fabric meet the technology requirement of the standards, meet the demand of the customer’s use requirements.

  10. Air-tolerant Fabrication and Enhanced Thermoelectric Performance of n-Type Single-walled Carbon Nanotubes Encapsulating 1,1'-Bis(diphenylphosphino)ferrocene.

    Science.gov (United States)

    Nonoguchi, Yoshiyuki; Iihara, Yu; Ohashi, Kenji; Murayama, Tomoko; Kawai, Tsuyoshi

    2016-09-01

    The thermally-triggered n-type doping of single-walled carbon nanotubes is demonstrated using 1,1'-bis(diphenylphosphino)ferrocene, a novel n-type dopant. Through a simple thermal vacuum process, the phosphine compounds are moderately encapsulated inside single-walled carbon nanotubes. The encapsulation into SWNTs is carefully characterized using Raman/X-ray spectroscopy and transmission electron microscopy. This easy-to-handle doping with air-stable precursors for n-type SWNTs enables the large-scale fabrication of thermoelectric materials showing an excellent power factor exceeding approximately 240 μW mK(-2) .

  11. Estimation of soil permeability

    Directory of Open Access Journals (Sweden)

    Amr F. Elhakim

    2016-09-01

    Full Text Available Soils are permeable materials because of the existence of interconnected voids that allow the flow of fluids when a difference in energy head exists. A good knowledge of soil permeability is needed for estimating the quantity of seepage under dams and dewatering to facilitate underground construction. Soil permeability, also termed hydraulic conductivity, is measured using several methods that include constant and falling head laboratory tests on intact or reconstituted specimens. Alternatively, permeability may be measured in the field using insitu borehole permeability testing (e.g. [2], and field pumping tests. A less attractive method is to empirically deduce the coefficient of permeability from the results of simple laboratory tests such as the grain size distribution. Otherwise, soil permeability has been assessed from the cone/piezocone penetration tests (e.g. [13,14]. In this paper, the coefficient of permeability was measured using field falling head at different depths. Furthermore, the field coefficient of permeability was measured using pumping tests at the same site. The measured permeability values are compared to the values empirically deduced from the cone penetration test for the same location. Likewise, the coefficients of permeability are empirically obtained using correlations based on the index soil properties of the tested sand for comparison with the measured values.

  12. Study on Dynamic Heat-moisture Transfer Properties of Summer Fabrics Using Microclimatic Method

    Institute of Scientific and Technical Information of China (English)

    JIANG Pei-qing; YAN Hao-jing

    2004-01-01

    The temperature and humidity of the microclimatic zone of summer fabrics in the course of sweating - evaporating - drying were measured with an apparatus specially made for the purpose. It is pointed out that temperature and humidity changes in quantitative perspiration evaporation process in the microclimatic zone can express the dynamic heat-moisture comfortability. Characteristic values include temperature decline speed, temperature rising speed, humidity rising speed, humidity balance value, and humidity decline speed. Fabrics with good air permeability are beneficial to improving comfortability of summer fabrics, while temperature rising speed and humidity decline speed in the microclimatic zone of thick and heavy fabrics with good hygroscopicity are relatively slow. Through comparing fabrics'dynamic heat-moisture curves obtained respectively with Microclimatic Method and Heat Loss Method, the two methods are identical essentially.

  13. Fabrication of an anti-viral air filter with SiO₂-Ag nanoparticles and performance evaluation in a continuous airflow condition.

    Science.gov (United States)

    Joe, Yun Haeng; Woo, Kyoungja; Hwang, Jungho

    2014-09-15

    In this study, SiO2 nanoparticles surface coated with Ag nanoparticles (SA particles) were fabricated to coat a medium air filter. The pressure drop, filtration efficiency, and anti-viral ability of the filter were evaluated against aerosolized bacteriophage MS2 in a continuous air flow condition. A mathematical approach was developed to measure the anti-viral ability of the filter with various virus deposition times. Moreover, two quality factors based on the anti-viral ability of the filter, and a traditional quality factor based on filtration efficiency, were calculated. The filtration efficiency and pressure drop increased with decreasing media velocity and with increasing SA particle coating level. The anti-viral efficiency also increased with increasing SA particle coating level, and decreased by with increasing virus deposition time. Consequently, SA particle coating on a filter does not have significant effects on filtration quality, and there is an optimal coating level to produce the highest anti-viral quality.

  14. Integrated sampling and analysis unit for the determination of sexual pheromones in environmental air using fabric phase sorptive extraction and headspace-gas chromatography-mass spectrometry.

    Science.gov (United States)

    Alcudia-León, M Carmen; Lucena, Rafael; Cárdenas, Soledad; Valcárcel, Miguel; Kabir, Abuzar; Furton, Kenneth G

    2017-03-10

    This article presents a novel unit that integrates for the first time air sampling and preconcentration based on the use of fabric phase sorptive extraction principles. The determination of Tuta absoluta sexual pheromone traces in environmental air has been selected as analytical problem. For this aim, a novel laboratory-built unit made up of commercial brass elements as holder of the sol-gel coated fabric extracting phase has been designed and optimized. The performance of the integrated unit was evaluated analyzing environmental air sampled in tomato crops. The unit can work under sampling and analysis mode which eliminates any need for sorptive phase manipulation prior to instrumental analysis. In the sampling mode, the unit can be connected to a sampling pump to pass the air through the sorptive phase at a controlled flow-rate. In the analysis mode, it is placed in the gas chromatograph autosampler without any instrumental modification. It also diminishes the risk of cross contamination between sampling and analysis. The performance of the new unit has been evaluated using the main components of the sexual pheromone of Tuta absoluta [(3E,8Z,11Z)-tetradecatrien-1-yl acetate and (3E,8Z)-tetradecadien-1-yl acetate] as model analytes. The limits of detection for both compounds resulted to be 1.6μg and 0.8μg, respectively, while the precision (expressed as relative standard deviation) was better than 3.7%. Finally, the unit has been deployed in the field to analyze a number of real life samples, some of them were found positive. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Fact Sheets: Final Rule to Reduce Toxic Air Pollutants from Printing, Coating, and Dyeing of Fabrics and Other Textiles

    Science.gov (United States)

    This page contains the February 2003 and the October 2004 final rule fact sheet that contain information on the NESHAP for Printing, Coating, and Dyeing of Fabrics and Other Textiles. These documents provide a summary of the information for this NESHAP.

  16. Permeability prediction in chalks

    DEFF Research Database (Denmark)

    Alam, Mohammad Monzurul; Fabricius, Ida Lykke; Prasad, Manika

    2011-01-01

    The velocity of elastic waves is the primary datum available for acquiring information about subsurface characteristics such as lithology and porosity. Cheap and quick (spatial coverage, ease of measurement) information of permeability can be achieved, if sonic velocity is used for permeability....... The relationships between permeability and porosity from core data were first examined using Kozeny’s equation. The data were analyzed for any correlations to the specific surface of the grain, Sg, and to the hydraulic property defined as the flow zone indicator (FZI). These two methods use two different approaches...... to enhance permeability prediction fromKozeny’s equation. The FZI is based on a concept of a tortuous flow path in a granular bed. The Sg concept considers the pore space that is exposed to fluid flow and models permeability resulting from effective flow parallel to pressure drop. The porosity-permeability...

  17. The Study of Fabric Performance for Car Seats

    Directory of Open Access Journals (Sweden)

    Antonin Havelka

    2017-09-01

    Full Text Available This paper deals with the investigation of the performance of car seat fabrics in terms of physiological comfort of sitting, specifi cally their water vapour resistance and air permeability. The current work presents an alternative approach to increasing the effectiveness of car seat fabrics through a combination of newly designed middle layer with forced convection achieved by a supplementary suction ventilation device. The supplementary device was designed to measure water vapour permeability by means of the sweating guarded hot plate (SGHP system. It consists of two parts: a frame to grip a tested sample for measurements within the SGHP system and two suction ventilators which are arranged at one end of the mentioned frame in order to provide suction into the tested fabric plane during the SGHP test. The results of this investigation show that water vapour transport is increased by approximately 20% compared to the standard way of measurement by means of SGHP because of forced air flow in the plane of ribbed – channelled structure of the car seat middle layer. The findings of this study have a number of important implications for future practice. The combination of a car seat cover with channelled structure and forced air fl ow improves physiological comfort of sitting which is a key issue for both drivers and manufacturers. The suggested device for forced air flow convection in the plane of a car seat fabric has not yet been part of an actual car seat, however it is possible to use its principles in a smart car seat prototype.

  18. Functional finishing in cotton fabrics using zinc oxide nanoparticles

    Indian Academy of Sciences (India)

    A Yadav; Virendra Prasad; A A Kathe; Sheela Raj; Deepti Yadav; C Sundaramoorthy; N Vigneshwaran

    2006-11-01

    Nanotechnology, according to the National Nanotechnology Initiative (NNI), is defined as utilization of structure with at least one dimension of nanometer size for the construction of materials, devices or systems with novel or significantly improved properties due to their nano-size. The nanostructures are capable of enhancing the physical properties of conventional textiles, in areas such as anti-microbial properties, water repellence, soil-resistance, anti-static, anti-infrared and flame-retardant properties, dyeability, colour fastness and strength of textile materials. In the present work, zinc oxide nanoparticles were prepared by wet chemical method using zinc nitrate and sodium hydroxide as precursors and soluble starch as stabilizing agent. These nanoparticles, which have an average size of 40 nm, were coated on the bleached cotton fabrics (plain weave, 30 s count) using acrylic binder and functional properties of coated fabrics were studied. On an average of 75%, UV blocking was recorded for the cotton fabrics treated with 2% ZnO nanoparticles. Air permeability of the nano-ZnO coated fabrics was significantly higher than the control, hence the increased breathability. In case of nano-ZnO coated fabric, due to its nano-size and uniform distribution, friction was significantly lower than the bulk-ZnO coated fabric as studied by Instron® Automated Materials Testing System. Further studies are under way to evaluate wash fastness, antimicrobial properties, abrasion properties and fabric handle properties.

  19. Honeycomb Core Permeability Under Mechanical Loads

    Science.gov (United States)

    Glass, David E.; Raman, V. V.; Venkat, Venki S.; Sankaran, Sankara N.

    1997-01-01

    A method for characterizing the air permeability of sandwich core materials as a function of applied shear stress was developed. The core material for the test specimens was either Hexcel HRP-3/16-8.0 and or DuPont Korex-1/8-4.5 and was nominally one-half inch thick and six inches square. The facesheets where made of Hercules' AS4/8552 graphite/epoxy (Gr/Ep) composites and were nominally 0.059-in. thick. Cytec's Metalbond 1515-3M epoxy film adhesive was used for co-curing the facesheets to the core. The permeability of the specimens during both static (tension) and dynamic (reversed and non-reversed) shear loads were measured. The permeability was measured as the rate of air flow through the core from a circular 1-in2 area of the core exposed to an air pressure of 10.0 psig. In both the static and dynamic testing, the Korex core experienced sudden increases in core permeability corresponding to a core catastrophic failure, while the URP core experienced a gradual increase in the permeability prior to core failure. The Korex core failed at lower loads than the HRP core both in the transverse and ribbon directions.

  20. Effect of Weave Structure on Thermo-Physiological Properties of Cotton Fabrics

    Directory of Open Access Journals (Sweden)

    Ahmad Sheraz

    2015-03-01

    Full Text Available This paper aims to investigate the relationship between fabric weave structure and its comfort properties. The two basic weave structures and four derivatives for each selected weave structure were studied. Comfort properties, porosity, air permeability and thermal resistance of all the fabric samples were determined. In our research the 1/1 plain weave structure showed the highest thermal resistance making it suitable for cold climatic conditions. The 2/2 matt weave depicted the lowest thermal resistance which makes it appropriate for hot climatic conditions.

  1. Design Research on Mix Proportion of Watertight and Air Permeable Epoxy Asphalt Mixtures%密水透气环氧沥青混合料配合比设计研究

    Institute of Scientific and Technical Information of China (English)

    曾利文; 王中文; 张肖宁

    2012-01-01

    国内外大跨径钢桥面和混凝土桥面的环氧沥青铺装过分强调配合比的密水性,导致销装层内水分挥发不出去,经过夏季高温气化后形成早期“鼓泡”病害.用马歇尔试验确定最佳油石比,在可控范围内通过调整油石比来调整混合料的孔隙率,进行不同孔隙率混合料的“密水透气”性试验,用自行开发的试验设备,找出混合料“密水透气”空隙率区间,开发无“鼓泡”现象环氧沥青混合料配合比,解决早期“鼓泡”病害.研究成果在虎门大桥钢桥面维修铺装施工中得到应用和验证.%For large-span steel and concrete bridge decks at home and abroad, excessive emphasis on water tightness of the mix proportion during pavement of epoxy asphalt causes non-volatile moisture inside the pavements and earlier" bubble" disease after gasification at high temperature in summer. This paper determines the optimal asphalt aggregate ratio by means of Marshall Test and adjusts porosity factors of mixtures by adjusting asphalt aggregate ratio in controllable range to perform the " watertight and air permeable" test for mixtures with different porosity factors. With self-development test equipment, the paper finds out the "watertight and air permeable" interval of porosity factors of mixtures and develops mix ratio of epoxy asphalt mixtures without "bubble" phenomenon to remove earlier "bubble" disease. The results of research are applied and verified in construction of repairing pavement of steel deck of Humen Bridge.

  2. 提高喷气织机产品质量的措施%Measures to Improve the Quality of the Fabrics Weaved on Air-jet Loom

    Institute of Scientific and Technical Information of China (English)

    陈玉凤

    2001-01-01

    介绍了如何进一步发展喷气织机固有的质量优势,对原纱质量,上浆质量,生产过程的质量信息管理学,以及对提高喷织质量的生产经验作了全面分析阐述,为提高喷气织机生产效能提供参考。%The thesis introduces how to make further use of the inherent qualitative advantages of an air-jet loom by analysing the quality of raw yarn,starching quality and the informational administration of quality in production,and by comprehensive introduction to the experince in improving the quality of the fabrics weaved on the air-jet loom,the thesis is for reference with the aim to improve the productive efficacy of air-jet loom.

  3. Fabrication of Free Air Well Type Ionization Chamber and Calculational Assessment and Measurement of Its Operational Characteristics

    Directory of Open Access Journals (Sweden)

    Koroush Arbabi

    2007-12-01

    Full Text Available Introduction: Well type ionization chamber is a measuring device which is used to determine the activity of brachytherapy sources. The chamber has a cylindrical volume in which a cylindrical tube is mounted in the middle of the chamber. For the measurements, the brachytherapy sources are transferred to the middle of the tube. Materials and Methods: For designing the well type chamber, the measurement principals of well type chambers were considered and MCNP-4C code as a calculation tool was used. The designed chamber was simulated and the response of the chamber was evaluated. In this investigation, the chamber operational parameters such as operating voltage, leakage current, reproducibility, reference measuring point, recombination and polarization factors as well as response stability for 137Cs, 57Co and 241Am sources were studied. Results: The chamber leakage currents at the operating voltage in comparison to the chamber response for the measurement of the above mentioned sources were negligible. The responses of the fabricated chamber for these sources are reproducible and its reference measurement position for these sources was obtained at 6 cm from the bottom of the chamber. The recombination factor for the well type chamber was negligible and the polarization factor is close to 1. Therefore, these two factors were not considered in the measurements. The reproducibility of the measurements in different intervals shows the stability of the chamber response for each source. Also the results of the chamber current measurement in term of source strength were compared to the response of the simulated chamber for different source positions and energy ranges of the used sources. Discussion and Conclusion: The results show that the measurement of the reference positions for each source in the simulated and fabricated chamber is quite in a good agreement. Regarding the reliable operational properties of the fabricated chamber, this chamber can be

  4. Recent Progress in Fabrication and Applications of Superhydrophobic Coating on Cellulose-Based Substrates

    Science.gov (United States)

    Liu, Hui; Gao, Shou-Wei; Cai, Jing-Sheng; He, Cheng-Lin; Mao, Jia-Jun; Zhu, Tian-Xue; Chen, Zhong; Huang, Jian-Ying; Meng, Kai; Zhang, Ke-Qin; Al-Deyab, Salem S.; Lai, Yue-Kun

    2016-01-01

    Multifuntional fabrics with special wettability have attracted a lot of interest in both fundamental research and industry applications over the last two decades. In this review, recent progress of various kinds of approaches and strategies to construct super-antiwetting coating on cellulose-based substrates (fabrics and paper) has been discussed in detail. We focus on the significant applications related to artificial superhydrophobic fabrics with special wettability and controllable adhesion, e.g., oil-water separation, self-cleaning, asymmetric/anisotropic wetting for microfluidic manipulation, air/liquid directional gating, and micro-template for patterning. In addition to the anti-wetting properties and promising applications, particular attention is paid to coating durability and other incorporated functionalities, e.g., air permeability, UV-shielding, photocatalytic self-cleaning, self-healing and patterned antiwetting properties. Finally, the existing difficulties and future prospects of this traditional and developing field are briefly proposed and discussed. PMID:28773253

  5. Airspace Analyzer for Assessing Airspace Directional Permeability Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We build a software tool which enables the user (airline or Air Traffic Service Provider (ATSP)) the ability to analyze the flight-level-by-flight-level permeability...

  6. Lightweight, Low Permeability, Cryogenic Thoraeus RubberTM Inflatables Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NanoSonic has developed a candidate state-of-the-art inflatable as a novel bladder material for life critical, space habitats that maintains low air permeability...

  7. Fabrication of macromolecular gradients in aligned fiber scaffolds using a combination of in-line blending and air-gap electrospinning.

    Science.gov (United States)

    Kishan, Alysha P; Robbins, Andrew B; Mohiuddin, Sahar F; Jiang, Mingliang; Moreno, Michael R; Cosgriff-Hernandez, Elizabeth M

    2016-12-22

    Although a variety of fabrication methods have been developed to generate electrospun meshes with gradient properties, no platform has yet to achieve fiber alignment in the direction of the gradient that mimics the native tendon-bone interface. In this study, we present a method combining in-line blending and air-gap electrospinning to address this limitation in the field. A custom collector with synced rotation permitted fiber collection with uniform mesh thickness and periodic copper wires were used to induce fiber alignment. Two poly(ester urethane ureas) with different hard segment contents (BPUR 50, BPUR 10) were used to generate compositional gradient meshes with and without fiber alignment. The compositional gradient across the length of the mesh was characterized using a fluorescent dye and the results indicated a continuous transition from the BPUR 50 to the BPUR 10. As expected, the fiber alignment of the gradient meshes induced a corresponding alignment of adherent cells in static culture. Tensile testing of the sectioned meshes confirmed a graded transition in mechanical properties and an increase in anisotropy with fiber alignment. Finite element modeling was utilized to illustrate the gradient mechanical properties across the full length of the mesh and lay the foundation for future computational development work. Overall, these results indicate that this electrospinning method permits the fabrication of macromolecular gradients in the direction of fiber alignment and demonstrate its potential for use in interfacial tissue engineering.

  8. Facile and Scalable Fabrication of Highly Efficient Lead Iodide Perovskite Thin-Film Solar Cells in Air Using Gas Pump Method.

    Science.gov (United States)

    Ding, Bin; Gao, Lili; Liang, Lusheng; Chu, Qianqian; Song, Xiaoxuan; Li, Yan; Yang, Guanjun; Fan, Bin; Wang, Mingkui; Li, Chengxin; Li, Changjiu

    2016-08-10

    Control of the perovskite film formation process to produce high-quality organic-inorganic metal halide perovskite thin films with uniform morphology, high surface coverage, and minimum pinholes is of great importance to highly efficient solar cells. Herein, we report on large-area light-absorbing perovskite films fabrication with a new facile and scalable gas pump method. By decreasing the total pressure in the evaporation environment, the gas pump method can significantly enhance the solvent evaporation rate by 8 times faster and thereby produce an extremely dense, uniform, and full-coverage perovskite thin film. The resulting planar perovskite solar cells can achieve an impressive power conversion efficiency up to 19.00% with an average efficiency of 17.38 ± 0.70% for 32 devices with an area of 5 × 2 mm, 13.91% for devices with a large area up to 1.13 cm(2). The perovskite films can be easily fabricated in air conditions with a relative humidity of 45-55%, which definitely has a promising prospect in industrial application of large-area perovskite solar panels.

  9. Towards improving efficiency of control for blowing into a boundary layer through a permeable wall

    Science.gov (United States)

    Fomin, V. M.; Kornilov, V. I.; Boiko, A. V.

    2016-08-01

    The results of experimental and numerical investigations of the efficiency of control by an incompressible turbulent boundary layer with the help air blowing through a permeable wall fabricated with maintenance of most of the necessary requirements for the quality and configuration of microapertures and having a low effective roughness are analyzed. Various cases of modeling the process of air blowing into the boundary layer through a specified hi-tech finely perforated surface are considered, and the data for average parameters and characteristics of turbulence of the flow types under investigation are presented. A substantial decrease in the skin-friction coefficient along the model length, which can achieve 90% with increasing the blowing coefficient, is shown. The estimate of the energy consumption for the process of blowing under terrestrial conditions testifies to the high potential of this method of control capable to provide 4-5% gain in the total aerodynamic drag of a simple modeling configuration.

  10. 土壤气相抽提影响半径及透气率现场试验%Field Study on Radius of Influence of Soil Vapor Extraction and Air Permeability of Soil

    Institute of Scientific and Technical Information of China (English)

    王峰; 王慧玲

    2011-01-01

    土壤气相抽提技术(SVE)可有效去除非饱和土壤中的挥发性有机污染物。土壤透气率及气相抽提的影响半径是进行SVE系统设计的重要参数,可通过多种方法取得。文章通过在北京市某焦化厂进行SVE现场试验,监测系统运行的土壤气相压力变化,求取土壤透气率及抽气影响半径。监测结果表明:SVE系统运行后,土壤中气相压力降最初不断增大,可在某—时刻达到稳定;压力降以抽气井为中心,向外围逐渐减小,其压力降梯度也渐趋平缓。可在现场试验资料的基础上,利用公式或绘制真空度随距离变化的半对数曲线求取影响半径;利用公式或监测井真空度随时间变化的半对数曲线(直线图解法)确定土壤透气率。SVE现场试验土壤参数计算结果与经验值一致,说明现场试验方法是进行参数计算的有效方法。%Volatile organic contaminants can be removed from soil using technology of soil vapor extraction (SVE). This paper describes an on-site experiment of SVE used for contaminated soil remediation at a coking plant in Beijing, in which variation of soil vapor pressure is monitored and radius of influence (ROI) of soil permeability is calculated. Results of the field test are used to calculate the ROI and to determine air permeability of soil based on a formula or the data of monitoring wells which describe changes of vacuum against time. Values of soil data acquired are consistent with the empirical ones, which indicate the effectiveness of the field test method.

  11. Permeability of edible coatings.

    Science.gov (United States)

    Mishra, B; Khatkar, B S; Garg, M K; Wilson, L A

    2010-01-01

    The permeabilities of water vapour, O2 and CO2 were determined for 18 coating formulations. Water vapour transmission rate ranged from 98.8 g/m(2).day (6% beeswax) to 758.0 g/m(2).day (1.5% carboxymethyl cellulose with glycerol). O2 permeability at 14 ± 1°C and 55 ± 5% RH ranged from 1.50 to 7.95 cm(3)cm cm(-2)s(-1)Pa(-1), with CO2 permeability 2 to 6 times as high. Permeability to noncondensable gases (O2 and CO2) was higher for hydrophobic (peanut oil followed by beeswax) coatings as compared to hydrophilic (whey protein concentrate and carboxymethyl cellulose).

  12. Permeability of edible coatings

    OpenAIRE

    B Mishra; Khatkar, B. S.; Garg, M. K.; Wilson, L.A.

    2010-01-01

    The permeabilities of water vapour, O2 and CO2 were determined for 18 coating formulations. Water vapour transmission rate ranged from 98.8 g/m2.day (6% beeswax) to 758.0 g/m2.day (1.5% carboxymethyl cellulose with glycerol). O2 permeability at 14 ± 1°C and 55 ± 5% RH ranged from 1.50 to 7.95 cm3cm cm−2s−1Pa−1, with CO2 permeability 2 to 6 times as high. Permeability to noncondensable gases (O2 and CO2) was higher for hydrophobic (peanut oil followed by beeswax) coatings as compared to hydrop...

  13. Soils - Mean Permeability

    Data.gov (United States)

    Kansas Data Access and Support Center — This digital spatial data set provides information on the magnitude and spatial pattern of depth-weighted, mean soil permeability throughout the State of Kansas. The...

  14. Permeable pavement study (Edison)

    Data.gov (United States)

    U.S. Environmental Protection Agency — While permeable pavement is increasingly being used to control stormwater runoff, field-based, side-by-side investigations on the effects different pavement types...

  15. Wearability-Research of Cotton Bamboo Hemp Blended Fabric%棉竹浆汉麻混纺织物服用性能研究

    Institute of Scientific and Technical Information of China (English)

    唐建东; 王平; 李立成

    2012-01-01

    Wearability of cotton bamboo hemp blended fabric was researched. Wearability of cotton/bamboo/hemp 40/40/20 blended fabric, cotton/hemp 80/20 blended fabric and pure cotton fabric were tested. Air permeability, moisture permeability, drapability and crease recovery of the three fabrics were contrasted, the test results were analyzed. The result shows that air permeability, moisture permeability, drapability and crease recovery of cotton bamboo hemp blended fabric are the best. It is considered that the wearability of cotton bamboo hemp blended fabric is the best and can be developed as military uniform and high grade clothing.%研究棉竹浆汉麻混纺织物的服用性能.对相同规格的棉/竹浆/汉麻40/40/20混纺织物、棉/汉麻80/20混纺织物和纯棉织物做了服用性能对比试验,比较了织物的透气性、透湿性、悬垂性和抗皱性差异,并对试验结果进行了分析.结果表明:棉竹浆汉麻混纺织物的透气性、透湿性、悬垂性、折痕回复性均优于棉汉麻混纺织物和纯棉织物.认为:棉竹浆汉麻混纺织物服用性能最佳,可用于开发军用服装及高档服饰.

  16. Preparation of in situ secondary synthesis of indoor air purification functional fabric at low temperature%低温原位二次合成法制备室内空气净化功能织物

    Institute of Scientific and Technical Information of China (English)

    王振华; 刘保江; 何瑾馨

    2011-01-01

    Air purification functional fabric with practical value was prepared using in situ secondary synthesis method at low temperature.The surface morphology of air purification functional fabric was characterized by scanning electron microscope (SEM), energy dispersive spectrometer (EDS), atomic force microscopy (AFM) and X-ray diffraction (XRD).The good air purification ability of the treated fabric was confirmed by the degradation test of formaldehyde.In addition, the strength of TiO2 secondary synthesized cotton fabric distinctly increased,and the fabric showed excellent UV irradiation protection properties.%以低温原位二次合成法,制备了具有实用价值的空气净化功能织物.利用扫描电镜(SEM)、能谱分析(EDS)、原子力显微镜(AFM)和X射线衍射(XRD)表征空气净化功能织物表面的形态结构,并通过甲醛降解试验证明了其具有较好的空气净化能力.此外,棉织物经TiO2低温原位二次合成后强73增加明显,且具备极佳的紫外线防护特性.

  17. Engineering fabrics in transportation construction

    Science.gov (United States)

    Herman, S. C.

    1983-11-01

    The following areas are discussed: treatments for reduction of reflective cracking of asphalt overlays on jointed-concrete pavements in Georgia; laboratory testing of fabric interlayers for asphalt concrete paving: interim report; reflection cracking models: review and laboratory evaluation of engineering fabrics; optimum-depth method for design of fabric-reinforced unsurfaced roads; dynamic test to predict field behavior of filter fabrics used in pavement subdrains; mechanism of geotextile performance in soil-fabric systems for drainage and erosion control; permeability tests of selected filter fabrics for use with a loess-derived alluvium; geotextile filter criteria; use of fabrics for improving the placement of till on peat foundation; geotextile earth-reinforced retaining wall tests: Glenwood Canyon, Colorado; New York State Department of Transportation's experience and guidelines for use of geotextiles; evaluation of two geotextile installations in excess of a decade old; and, long-term in situ properties of geotextiles.

  18. Perméabilités à l'air et à l'eau d'une série de grès argileux. Mise en évidence de l'influence électrochimique et texturale de l'argile Permeabilities to Air and Water of a Shaly Sandstone Series. Demonstrating the Electrochemical and Textural Influence of Clay

    Directory of Open Access Journals (Sweden)

    Giouse H.

    2006-11-01

    Full Text Available Des mesures de perméabilités à l'air et à l'eau (solutions sodiques et calciques de différentes concentrations sur 18 grès argileux très divers sont présentées et discutées. L'argilosité des échantillons est définie par la capacité d'échange de cations, mesurée chimiquement ou calculée par l'interprétation des mesures de conductivité électrique suivant le modèle à deux eaux . La perméabilité à l'eau est variable suivant la concentration et la nature chimique de la solution qui circule. Des corrélations avec la conductivité Cw de la solution sont proposées et leur discussion souligne le double effet de l'argile : électrochimique par l'interaction de l'eau avec ses surfaces chargées et textural par l'augmentation de la tortuosité du milieu poreux. Measurements of air and water permeability (water is sodium or calcium solution, with various concentrations on 18 shaly sandstones (wide range of variation of the characteristics are presented and discussed. The shaliness of the samples is defined by cation exchange capacity, measured by chemical method or computed by interpreting with the dual watermodel some electrical conductivity measurements. The water permeability is a function of the concentration and the composition of the flowing brine. Some correlations with discussion emphasizes the double effect of the clay: electrochemical, due to the interaction of water with the charged surfaces, and textural due to an increase of the porous medium tortuosity.

  19. Permeability of Hollow Microspherical Membranes to Helium

    Science.gov (United States)

    Zinoviev, V. N.; Kazanin, I. V.; Pak, A. Yu.; Vereshchagin, A. S.; Lebiga, V. A.; Fomin, V. M.

    2016-01-01

    This work is devoted to the study of the sorption characteristics of various hollow microspherical membranes to reveal particles most suitable for application in the membrane-sorption technologies of helium extraction from a natural gas. The permeability of the investigated sorbents to helium and their impermeability to air and methane are shown experimentally. The sorption-desorption dependences of the studied sorbents have been obtained, from which the parameters of their specific permeability to helium are calculated. It has been established that the physicochemical modification of the original particles exerts a great influence on the coefficient of the permeability of a sorbent to helium. Specially treated cenospheres have displayed high efficiency as membranes for selective extraction of helium.

  20. Structural stability and oxygen permeability of BaCo{sub 1−x}Nb{sub x}O{sub 3−δ} ceramic membranes for air separation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Chengzhang, E-mail: wucz@shu.edu.cn [Shanghai Key Laboratory of Modern Metallurgy and Materials Processing, Shanghai University, Shanghai 200072 (China); Gai, Yongqian; Zhou, Jianfang; Tang, Xia; Zhang, Yunwen; Ding, Weizhong [Shanghai Key Laboratory of Modern Metallurgy and Materials Processing, Shanghai University, Shanghai 200072 (China); Sun, Chenghua [School of Chemistry, Monash University, Clayton, VIC 3800 (Australia)

    2015-07-25

    Highlights: • BCNx membranes with high oxygen permeation flux were prepared. • Oxygen permeability of BCNx membranes is stable at 900 °C. • Phase transition is governed by oxygen partial pressure and temperature. • Degradation mechanism of BCNx membrane is suggested. - Abstract: BaCo{sub 1−x}Nb{sub x}O{sub 3−δ} (BCNx, x = 0.1–0.2) membranes were synthesized through conventional solid-phase reactions. The introduction of niobium facilitates the formation of the cubic perovskite structure and decreases oxygen nonstoichiometry. BCNx membranes possess higher oxygen permeation flux compared with BaCo{sub 0.7}Fe{sub 0.2}Nb{sub 0.1}O{sub 3−δ} membrane at the same condition. A stable permeation flux as high as 2.61 ml cm{sup −2} min{sup −1} is obtained through BaCo{sub 0.9}Nb{sub 0.1}O{sub 3−δ} membrane at 900 °C under the Air/He gradient. Long-time permeation study shows that the oxygen fluxes of BCNx membranes are stable at 900 °C but degrade slowly with time at 850 °C. XRD and TG–DSC results indicate that the degradation behavior occured at 850 °C is due to the phase transition from the cubic perovskite to monoclinic or orthorhombic structure, which is governed by the oxygen partial pressure and temperature. The oxidation of cobalt ion is considered to be the nature for the phase transition, which makes the tolerance factor increasing and results in structural destabilization.

  1. Impenetrable infiltration: air permeability of Dutch dwellings

    NARCIS (Netherlands)

    Entrop, Bram; Hensen, Jan; Loomans, Marcel; Brons, Ron; Veldhoff, Alex; Averink, Jan

    2014-01-01

    Het is wenselijk dat gebouwen beschikken over voldoende en de juiste mogelijkheden om te ventileren. Buiten de benodigde ventilatievoorzieningen is het echter de bedoeling een gebouw zo luchtdicht mogelijk te maken ten einde comfortklachten en onnodig energiegebruik te voorkomen. In het Bouwbesluit

  2. Effect of anatomical and chemical structure in the permeability of "Amapá" wood

    OpenAIRE

    Edy Eime Pereira Baraúna; José Tarcísio Lima; Renato da Silva Vieira; José Reinaldo Moreira da Silva; Thiago Campos Monteiro

    2014-01-01

    This paper aimed to study the permeability to air and liquid, in the longitudinal direction of "amapá" wood (Brosimum parinarioides Ducke), originating from the Amazon Forest. Furthermore, the influence of anatomical and chemical characteristics in the permeability of the wood was investigated. For this study, samples were collected from three trees, in the state of Pará, Brazil, and submitted to permeability test, anatomical characterization, and chemical analyses. The permeability to the ai...

  3. Graphene Oxide Involved Air-Controlled Electrospray for Uniform, Fast, Instantly Dry, and Binder-Free Electrode Fabrication.

    Science.gov (United States)

    Fei, Ling; Yoo, Sang Ha; Villamayor, Rachel Ann R; Williams, Brian P; Gong, Seon Young; Park, Sunchan; Shin, Kyusoon; Joo, Yong Lak

    2017-03-22

    We report a facile air-controlled electrospray method to directly deposit binder-free active materials/graphene oxide (GO) onto current collectors. This method is inspired from an electrospinning process, and possesses all the advantages that electrospinning has such as low cost, easy scaling up, and simultaneous solvent evaporation during the spraying process. Moreover, the spray slurry is only a simple mixture of active materials and GO suspension in water, no binder polymer, organic solvent, and conductive carbon required. In our research, high-capacity Si nanoparticles (Si NP, 70-100 nm) and SiO microparticles (SiO MP, 3-10 μm) were selected to demonstrate the capability of this method to accommodate particles with different sizes. Their mixture with GO was sprayed onto a collector and then thermally annealed in an inert gas to obtain Si NP or SiO MP/reduced graphene oxide (RGO) binder-free electrodes. We are also able to directly deposit fairly large electrode sheets (e.g., 12 × 21 in.) upon the application requirement. To the best of our knowledge, this is the simplest approach to produce Si-related materials/RGO layered structures directly on current collector with controllable area and loading. Si and SiO MP/RGO are evaluated in both half and full lithium cells, showing good electrochemical performance. Prelithiation is also studied and gives a high first cycle Coulombic efficiency. In addition to Si-related materials, other materials with different shapes and sizes (e.g., MoO3 nanobelts, Sn/carbon nanofibers, and commercial sulfur particles) can also be sprayed. Beyond the preparation of battery electrodes, this approach can also be applied for other types of electrode preparation such as that of a supercapacitor, fuel cell, and solar cell.

  4. Ferritas Ni-Zn: breve revisão sobre o processo convencional de fabricação e as propriedades permeabilidade magnética e constante dielétrica Ni-Zn ferrites: brief review on the conventional method of fabrication and the magnetic permeability and dielectric constant properties

    Directory of Open Access Journals (Sweden)

    V. L. O. Brito

    2006-12-01

    Full Text Available As ferritas Ni-Zn são cerâmicas magnéticas que têm sido amplamente aplicadas na fabricação de componentes elétricos e eletrônicos. Esses materiais têm sido estudados há décadas por diversos autores, os quais têm definido a relação entre as propriedades magnéticas e elétricas dessas ferritas em função de diversos fatores, tais como as variáveis do processo de fabricação, composição química e microestrutura. Este trabalho mostra uma revisão dos principais fatores que influenciam as propriedades das ferritas Ni-Zn, com foco na permeabilidade magnética e constante dielétrica e enfatizando as características do método cerâmico convencional na fabricação desses materiais.Ni-Zn ferrites are magnetic ceramics that have been widely used on the fabrication of electrical and electronic components. Such materials have been studied for many years by several researchers and their magnetic and electrical properties have been assessed in relation to many factors, such as chemical composition, fabrication methods, and microstructure. This work makes a review of the main factors influencing the properties of Ni-Zn ferrites. It is emphasized the magnetic permeability and dielectric constant, as well as the characteristics of the conventional ceramic method on the fabrication of these ferrites.

  5. Biostable glucose permeable polymer

    DEFF Research Database (Denmark)

    2017-01-01

    A new biostable glucose permeable polymer has been developed which is useful, for example, in implantable glucose sensors. This biostable glucose permeable polymer has a number of advantageous characteristics and, for example, does not undergo hydrolytic cleavage and degradation, thereby providing...... a composition that facilitates long term sensor stability in vivo. The versatile characteristics of this polymer allow it to be used in a variety of contexts, for example to form the body of an implantable glucose sensor. The invention includes the polymer composition, sensor systems formed from this polymer...

  6. Development of Multifunctional Anti Aging Military Raincoat Fabric by Using Fitting Technique

    OpenAIRE

    Chen Chun Xia

    2016-01-01

    Use Woodland camouflage paint Oxford fabric as base cloth, first the light pressure processing was used on the fabric, and then use polyurethane which has high water vapor permeability performance and other various additives as face glue and Bottom glue, the fabric was compounded a thin macromolecule hydrophilic polymer PU film, the fabric was water allocation processed after stripping, At last the fabric will have high performance of the windproof, waterproof and moisture permeability. After...

  7. Análise fluido-dinâmica do escoamento em ensaio de permeabilidade ao ar de argamassas preparadas com cimento Portland de alto-forno Fluid-dynamic analysis of the flow in air permeability measurement of mortars prepared with blast-slag furnace Portland cement

    Directory of Open Access Journals (Sweden)

    V. M. Pereira

    2008-06-01

    . These studies not only have evaluated the permeability of porous media, but also to analyze the behavior of the fluid during the flow. Being about to the cement based materials, the measuring of the permeability becomes basic so that the durability of these can be estimate, therefore is the permeability that controls the rate of ingression and movement of deleterious agents inside these materials. Thus, diverse methodologies and mathematical equations have been used to foresee the permeability of cementitious materials, however, some discrepancies and nonsense in the results have been found. Amongst the used methodologies to measure the permeability of porous media, one meets developed it by Thenoz, which it has demonstrated good results in cement based materials. Thus, this work aims at, by means of assay of permeability to air, carried through in accordance with the methodology of Thenoz, to evaluate the fluid-dynamic behavior of air during the assay of permeability in mortars. For this, mortars prepared with two types of Portland cement of blast furnace (CP IIE-32 and CP III - 32, two relations water/cement (0.5 and 0.6 and ages of 14 and 28 days were used. By means of the gotten results it was possible to observe that during the draining the compressibility of air can be ignored, the regimen of draining can be considered as to plate, demonstrating that the methodology proposal for Thenoz and used mathematical equations can result in coefficients of trustworthy air permeability, therefore phenomena and considerations that could influence in this type of flow can be neglected, in accordance with what it is considered by literature.

  8. Measurement of relative permeability of fuel cell diffusion media

    KAUST Repository

    Hussaini, I.S.

    2010-06-01

    Gas diffusion layer (GDL) in PEM fuel cells plays a pivotal role in water management. Modeling of liquid water transport through the GDL relies on knowledge of relative permeability functions in the in-plane and through-plane directions. In the present work, air and water relative permeabilities are experimentally determined as functions of saturation for typical GDL materials such as Toray-060, -090, -120 carbon paper and E-Tek carbon cloth materials in their plain, untreated forms. Saturation is measured using an ex situ gravimetric method. Absolute and relative permeability functions in the two directions of interest are presented and new correlations for in-plane relative permeability of water and air are established. © 2010 Elsevier B.V. All rights reserved.

  9. Permeable Pavement Research at NRMRL’s Urban Watershed Research Facility (Poster 2)

    Science.gov (United States)

    Assess pollutant removal efficiency of porous pavement systems with regard to parking lot runoff. Bench-scale study will examine: Discharge volume Flow rate Total suspended solids (TSS) of influent vs. effluent Use of a geotextile permeable filter fabric...

  10. 地铁工程风管制作安装应注意的质量问题%Quality Problems Should Pay Attention in the Fabrication and Installation of Subway Air Pipe

    Institute of Scientific and Technical Information of China (English)

    王毅

    2013-01-01

    Because of the subway engineering air conditionin-g wind system is large, pipeline is huge and complex, coupled with the limitations of the subway space, making fabrication and instal ation of subway air pipe should be strict, in order to have no trouble.%  由于地铁工程空调风系统庞大、管线多且复杂,再加上地铁空间的局限性,地铁工程风管制作安装应严把质量关,以做到有备而无患。

  11. Practice of Producing Broad Width Fabric on Single Loom Beam Air Jet Loom%单织轴喷气织机生产宽幅织物的实践

    Institute of Scientific and Technical Information of China (English)

    王美红; 孙鉴丽

    2012-01-01

    Key technology measures of producing broad width fabric on single loom beam air jet loom were discussed. Problems existed in producing broad width fabric on two-beam air jet loom were analyzed, It is considered that supporting broad width warping machine and sizing machine should be selected in producing broad width fabric on single loom beam air jet loom. Processing parameter in each process should be selected rationally such as tension. Side yarn should be controlled well in weaving, temperature & humidity should be selected properly,finally loom efficiency can be reach above 92% , production demands can be reached.%探讨使用单织轴喷气织机生产宽幅织物的关键技术措施.通过分析双织轴喷气织机生产宽幅织物时存在的问题,认为:采用单织轴喷气织机生产宽幅织物时,应选用配套的宽幅整经机与宽幅浆纱机,各道工序合理配置张力等工艺参数;织造时加强边纱的控制,选择适宜的温湿度条件,最终使得织机效率达到92%,满足了生产要求.

  12. Dehumidification System with Steam Permeability Films

    Science.gov (United States)

    Ishikwa, Masaaki; Sekimori, Souji; Ogiwara, Shigeaki; Ochiai, Tetsunari; Hirata, Tetsuo

    In a factory with a clean room facility in cold regions, dew-condensation on walls of the facility is one of the most serious problems in winter. In this study, a new dehumidification system in which a steam permeability film is located between humid air in a clean room and dry air from outside to exchange steam is proposed. This system can treat a lot of humid air with small energy only for driving fans to flow air. Some films are examined in two kinds of steam exchangers; double tube type and flat p1ate type. Steam permeability resistance and therma1 resistance of each film are first obtained in a double tube type exchanger. An analytica1 model for a flat plate type exchanger is then proposed, which shows good agreement with experimental data. Steam and heat transfer characteristics of a flat plate type exchanger are also evaluated experimentally. One film on a flat plate type exchanger shows dehumidification capacity of 0.033g/s(=120g/h )with its area of 2.232m2.

  13. Fabric Selection for the Reference Clothing Destined for Ergonomics Test of Protective Clothing: Physiological Comfort Point of View

    Directory of Open Access Journals (Sweden)

    Bartkowiak Grażyna

    2016-12-01

    Full Text Available The currently used methods of ergonomic assessment of protective clothing depend on the subjective feeling of research participants and don’t take into consideration all aspects of its use. Therefore, more amount of work is undertaken toward the development of new research tools for the ergonomic assessment of protective clothing. Research was carried out at the Central Institute for Labour Protection – National Research Institute in Lodz. A new methodology will take into consideration a variant of reference clothing, which is related to the results of ergonomics research of protective clothing. Preparation of the reference clothing initiated by picking the appropriate fabric is based on the results of parameters influencing the physiological comfort and sensorial comfort. In the current part, results of different fabric parameters are presented, which are related to physiological comfort, i.e., the thermal resistance, water vapor resistance, hygroscopicity, and air permeability. In the next part of research, we will focus on the parameters related to objective sensorial feelings, i.e., total hand value and its components. Seven fabrics, including six cotton/polyester fabrics, diverse in terms of constituent fiber content and structure parameters (weave, thread density per 1 dm, thread linear density, mass per square meter, thickness, and Tencel/polyester fabric were tested. The best in terms of thermal resistance, water vapor resistance, and air permeability was the cotton/polyester fabric (35% cotton/65% PES with the smallest mass per square meter. This fabric also exhibits the high hygroscopicity of 7.5%, which puts it into the fourth position.

  14. Ammonia gas permeability of meat packaging materials.

    Science.gov (United States)

    Karim, Faris; Hijaz, Faraj; Kastner, Curtis L; Smith, J Scott

    2011-03-01

    Meat products are packaged in polymer films designed to protect the product from exterior contaminants such as light, humidity, and harmful chemicals. Unfortunately, there is almost no data on ammonia permeability of packaging films. We investigated ammonia permeability of common meat packaging films: low-density polyethylene (LDPE; 2.2 mil), multilayer polyolefin (MLP; 3 mil), and vacuum (V-PA/PE; 3 mil, 0.6 mil polyamide/2.4 mil polyethylene). The films were fabricated into 10 × 5 cm pouches and filled with 50 mL deionized water. Pouches were placed in a plexiglass enclosure in a freezer and exposed to 50, 100, 250, or 500 ppm ammonia gas for 6, 12, 24, and 48 h at -17 ± 3 °C and 21 ± 3 °C. At freezing temperatures, no ammonia residues were detected and no differences in pH were found in the water. At room temperature, ammonia levels and pH of the water increased significantly (P packaging materials have low ammonia permeability and protect meat products exposed to ammonia leaks during frozen storage.

  15. Moisture Management Behaviour of Knitted Fabric from Structurally Modified Ring and Vortex Spun Yarn

    Science.gov (United States)

    Sharma, Navendu; Kumar, Pawan; Bhatia, Dinesh; Sinha, Sujit Kumar

    2016-10-01

    The acceptability of a new product is decided by its performance, level of improvement in quality and economy of production. The basic aim of generating micro pores in a textile structure is to provide better thermo-physiological comfort by enhancing the breathability and hence improving moisture management behaviour. In the present study, an attempt has been made to create a relatively more open structure through removal of a component. A comparative assessment with a homogeneous and parent yarn was also made. Yarns of two linear densities, each from ring and vortex spinning systems were produced using 100 % polyester and 80:20 polyester/cotton blend. The modified yarn was produced by removing a component, viz; cotton, by treatment with sulphuric acid from the blended yarn. The knitted fabric from modified yarn was found to show significant improvement in air permeability, water vapour permeability and total absorbency while the wicking characteristic was found to decline.

  16. Relative permeability through fractures

    Energy Technology Data Exchange (ETDEWEB)

    Diomampo, Gracel, P.

    2001-08-01

    The mechanism of two-phase flow through fractures is of importance in understanding many geologic processes. Currently, two-phase flow through fractures is still poorly understood. In this study, nitrogen-water experiments were done on both smooth and rough parallel plates to determine the governing flow mechanism for fractures and the appropriate methodology for data analysis. The experiments were done using a glass plate to allow visualization of flow. Digital video recording allowed instantaneous measurement of pressure, flow rate and saturation. Saturation was computed using image analysis techniques. The experiments showed that gas and liquid phases flow through fractures in nonuniform separate channels. The localized channels change with time as each phase path undergoes continues breaking and reforming due to invasion of the other phase. The stability of the phase paths is dependent on liquid and gas flow rate ratio. This mechanism holds true for over a range of saturation for both smooth and rough fractures. In imbibition for rough-walled fractures, another mechanism similar to wave-like flow in pipes was also observed. The data from the experiments were analyzed using Darcy's law and using the concept of friction factor and equivalent Reynold's number for two-phase flow. For both smooth- and rough-walled fractures a clear relationship between relative permeability and saturation was seen. The calculated relative permeability curves follow Corey-type behavior and can be modeled using Honarpour expressions. The sum of the relative permeabilities is not equal one, indicating phase interference. The equivalent homogeneous single-phase approach did not give satisfactory representation of flow through fractures. The graphs of experimentally derived friction factor with the modified Reynolds number do not reveal a distinctive linear relationship.

  17. Fabrication Facilities

    Data.gov (United States)

    Federal Laboratory Consortium — The Fabrication Facilities are a direct result of years of testing support. Through years of experience, the three fabrication facilities (Fort Hood, Fort Lewis, and...

  18. Line focus by the ellipsoidal and hyperbolic mirrors, and the fabrication of the new type`s heated air engine. 1; Daenmenkyo to sokyokumenkyo ni yoru line focus to shingata netsu kuki engine no shisaku. 1

    Energy Technology Data Exchange (ETDEWEB)

    Shishido, K.; Kazimierski, Z.; Shoji, T. [Tohoku Gakuin University, Sendai (Japan). Faculty of Engineering; Sugiura, M. [Tohoku Gakuin Tsutsujigaoka High School, Sendai (Japan); Kobayashi, Y. [Tokyo Special Glass Co. Ltd., Tokyo (Japan)

    1996-10-27

    Line focusing by ellipsoidal and hyperbolic mirrors was devised for solar heat collection, and the new prototype heated air engine is under fabrication based on such focusing. Ellipse is a locus of the point at which the distance from the 2nd focus is equal to that from the circle with the 1st focus as a center and the major axis as a radius. Hyperbola can be also figured under similar geometric conditions. The link mechanism possible to machine quadratic surfaces based on the above principle has been developed. High-precision quadratic surface mirrors can be fabricated by the link mechanism for convergent solar heat power generation, achieving line focusing of light. The new prototype heated air engine is also proposed which is composed of the heating part by line focusing, cylinder, piston and cooling column. This engine is featured by simple function, light weight, compact body, high efficiency and safety, and is under fabrication. Although conventional converging mirrors use all the mirror surface, the new line focusing uses only the upper part of the mirror, and the lower part is turned over for protection of the mirror from strong wind. 9 figs.

  19. Feasibility Assessments of the Use of Recycled Fibers in Nonwoven Fabrics

    Directory of Open Access Journals (Sweden)

    Jia-Horng Lin

    2017-01-01

    Full Text Available Environmental protection has become an increasing concern, which makes recycling and reclaiming highly important. In addition to governmental campaigns and promotion, enterprises should examine each perspective thoroughly in order to prevent excessive resource consumption. In this study, recycled materials, including recycled far-infrared polyester (FPET fiber, three-dimensional crimped hollow flame-retarding (TPET fiber, and low-melting-point polyester (LPET fiber, are used to form nonwoven fabrics. The influence of different amounts of FPET fiber, 0–80 wt %, on the properties of nonwoven fabrics was examined. The sheath of LPET fibers can be melted as a result of hot pressing, which provides cohesion between fibers that mechanically improves the nonwoven fabrics. The tensile strength, tearing strength, air permeability, and far infrared (FIR emissivity of the nonwoven fabrics were examined, thereby determining the optimal parameters. The test results show that the thermally treated nonwoven fabrics have better mechanical properties and FIR emissivity, compared to those of non-thermally treated nonwoven fabrics. Moreover, more FPET fibers cause the mechanical properties along the cross machine direction (CD to decrease by 9% and that along the machine direction (MD to decrease by 5%. In particular, all the thermally treated samples exhibit a FIR emissivity of 0.8, which is health-promoting.

  20. Permeability studies on 3D Ni foam/graphene composites

    Science.gov (United States)

    Yang, Zhuxian; Chen, Hongmei; Wang, Nannan; Xia, Yongde; Zhu, Yanqiu

    2017-09-01

    This study investigates the permeability of new 3D Ni foam/graphene composites (Ni foam covered with graphene) using compressed air, Ar and N2 as the probe gases. The results show that the introduction of graphene on the surface of Ni foam via in situ chemical vapour deposition is not detrimental to the permeability of the composites; on the contrary, in some cases it improves permeability. A modified Ergun-type correlation has been proposed, which represents very well the permeability of the Ni foam/graphene composites, especially at flow rates higher than 0.3 m s-1. Further studies show that graphene also helps to improve the thermal conductivity of the composite. These results suggest that the graphene involvement will make the Ni foam/graphene composite a good candidate for potential applications such as filters or heat exchangers suitable for working under harsh conditions such as at high temperatures, in corrosive environments, etc.

  1. Permeability analysis for thermal binder removal from green ceramic bodies

    Science.gov (United States)

    Yun, Jeong Woo

    2007-12-01

    The permeability of unlaminated and laminated green tapes was determined as a function of binder content for binder removed by air oxidation. The tapes are comprised of barium titanate as the dielectric, and polyvinyl butyral and dioctyl phthalate as the main compoents of the binder mixture. The flow in porous media through the tapes was analyzed in terms of models for describing Knudsen, slip, and Poiseuille flow mechanisms. The characteristic pore size was determined to be 0.5-2 mum and thus Poiseuille flow was the dominant transport mechanism contributing to the flux. The permeability was then determined from Darcy's law for flow in porous media. The permeability was also determined from micro-structural attributes in terms of the specific surface, the pore fraction, and terms to account for tortuosity and constrictions. The permeability and adhesion strength of laminated green ceramic tapes were determined as a function of lamination conditions of time, temperature, and pressure.

  2. Low Permeability Polyimide Insulation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Resodyn Technologies proposes a new technology that enables the application of polyimide based cryogenic insulation with low hydrogen permeability. This effort...

  3. Influence of gold species (AuCl4(-) and AuCl2(-)) on self-assembly of PS-b-P2VP in solutions and morphology of composite thin films fabricated at the air/liquid interfaces.

    Science.gov (United States)

    Zhao, Xingjuan; Wang, Qian; Zhang, Xiaokai; Lee, Yong-Ill; Liu, Hong-Guo

    2016-01-21

    Composite thin films doped with Au species were fabricated at an air/liquid interface via a series of steps, including the mass transfer of polystyrene-b-poly(2-vinylpyridine) (PS-b-P2VP) across the liquid/liquid interface between a DMF/CHCl3 solution and an aqueous solution containing either AuCl4(-) or AuCl2(-), self-assembly of PS-b-P2VP in a mixed DMF-water solution, and adsorption and further self-organization of the formed aggregates at the air/liquid interface. This is a new approach for fabricating composite polymer films and can be completed within a very short time. AuCl4(-) and AuCl2(-) ions were found to significantly influence the self-assembly behavior of the block copolymer and the morphologies of the composite films, leading to the formation of nanowire arrays and a foam structure at the air/liquid interface, respectively, which originated from rod-like micelles and microcapsules that had formed in the respective solutions. The effect of the metal complex was analyzed based on the packing parameters of the amphiphilic polymer molecules in different microenvironments and the interactions between the pyridine groups and the metal chloride anions. In addition, these composite thin films exhibited stable and durable performance as heterogeneous catalysts for the hydrogenation of nitroaromatics in aqueous solutions.

  4. Effect of anatomical and chemical structure in the permeability of "Amapá" wood

    Directory of Open Access Journals (Sweden)

    Edy Eime Pereira Baraúna

    2014-12-01

    Full Text Available This paper aimed to study the permeability to air and liquid, in the longitudinal direction of "amapá" wood (Brosimum parinarioides Ducke, originating from the Amazon Forest. Furthermore, the influence of anatomical and chemical characteristics in the permeability of the wood was investigated. For this study, samples were collected from three trees, in the state of Pará, Brazil, and submitted to permeability test, anatomical characterization, and chemical analyses. The permeability to the air of the "amapá" wood was estimated at 63.7.10-9 m3.[m.(N.m-2.s]-1 and to the liquid was 2.07.10-9 m3.[m.(N.m-2.s]-1. There were low correlations between air and liquid permeability and the anatomical features.

  5. Laser deposition of TiO2 nanoparticles on glass fabric

    Science.gov (United States)

    Wiener, J.; Shahidi, S.; Goba, M. M.

    2013-02-01

    In this research work light laser irradiation was used for deposition of titanium dioxide nanoparticles on the surface of glass mat. For this purpose TiO2 nanoparticles were evenly applied on the surface of a glass fiber mat. The glass fiber mat containing the metals was then irradiated with the laser light beam (100 μs). The morphology of the fabrics was observed using a Scanning Electron Microscope. An X-ray fluorescence spectrum and energy dispersive X-ray were used for elemental analysis. Also mechanical properties and air permeability of the irradiated samples were analyzed and the results show that both tenacity and elongation of laser irradiated sample are reduced but the air permeability is improved after laser irradiation. The photocatalytic activities of TiO2 deposited glass fabrics were assessed by analyzing the decrease in concentration of the Orange II as a colorant after exposure to UV irradiation. The results clarify that the Orange II concentration decreases continuously, concomitant with the UV irradiation time up to 270 min.

  6. Triaxial Permeability Device

    Science.gov (United States)

    1988-01-01

    closing valves #16 and 19. Valves #11, 12, and 13 are then opened. The three way valves #5 and 8 should be set so flow is directed to the mercury manometer . The...in the influent mercury manometer leg to the maximum height using air pressure from the backpres- sure regulator. This drives much of the water out

  7. Permeability testing of biomaterial membranes

    Energy Technology Data Exchange (ETDEWEB)

    Dreesmann, L; Hajosch, R; Nuernberger, J Vaz; Schlosshauer, B [NMI Natural and Medical Sciences Institute at University Tuebingen, Markwiesenstr. 55, D-72770 Reutlingen (Germany); Ahlers, M [GELITA AG, Gammelsbacher Str. 2, D-69412 Eberbach (Germany)], E-mail: schlosshauer@nmi.de

    2008-09-01

    The permeability characteristics of biomaterials are critical parameters for a variety of implants. To analyse the permeability of membranes made from crosslinked ultrathin gelatin membranes and the transmigration of cells across the membranes, we combined three technical approaches: (1) a two-chamber-based permeability assay, (2) cell culturing with cytochemical analysis and (3) biochemical enzyme electrophoresis (zymography). Based on the diffusion of a coloured marker molecule in conjunction with photometric quantification, permeability data for a gelatin membrane were determined in the presence or absence of gelatin degrading fibroblasts. Cytochemical evaluation after cryosectioning of the membranes was used to ascertain whether fibroblasts had infiltrated the membrane inside. Zymography was used to investigate the potential release of proteases from fibroblasts, which are known to degrade collagen derivatives such as gelatin. Our data show that the diffusion equilibrium of a low molecular weight dye across the selected gelatin membrane is approached after about 6-8 h. Fibroblasts increase the permeability due to cavity formation in the membrane inside without penetrating the membrane for an extended time period (>21 days in vitro). Zymography indicates that cavity formation is most likely due to the secretion of matrix metalloproteinases. In summary, the combination of the depicted methods promises to facilitate a more rational development of biomaterials, because it provides a rapid means of determining permeability characteristics and bridges the gap between descriptive methodology and the mechanistic understanding of permeability alterations due to biological degradation.

  8. Low-cost fabrication of WO{sub 3} films using a room temperature and low-vacuum air-spray based deposition system for inorganic electrochromic device applications

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung-Ik [Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul (Korea, Republic of); Kim, Sooyeun, E-mail: sooyeunk@u.washington.edu [Department of Mechanical Engineering, University of Washington, Seattle, WA (United States); Choi, Jung-Oh; Song, Ji-Hyeon [Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul (Korea, Republic of); Taya, Minoru [Department of Mechanical Engineering, University of Washington, Seattle, WA (United States); Ahn, Sung-Hoon, E-mail: ahnsh@snu.ac.kr [Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul (Korea, Republic of); Institute of Advanced Machines and Design, Seoul (Korea, Republic of)

    2015-08-31

    We report the deposition of tungsten oxide (WO{sub 3}) thin films on fluorine-doped tin oxide (FTO) and indium-doped tin oxide (ITO) glass substrates by using a room-temperature deposition system based on low-vacuum air-spray for the fabrication of inorganic electrochromic windows. The structure of the WO{sub 3} films was characterized using X-ray diffraction, and the surface morphology and film thickness were investigated using scanning electron microscopy and atomic force microscopy. The color of the prepared WO{sub 3} films changed from slight yellow to dark blue under applied voltages, demonstrating electrochromism. The WO{sub 3} film coated FTO glass exhibited a large electrochromic contrast of up to 50% at a wavelength of 800 nm. The electrochemical properties of the films were examined using cyclic voltammetry and chronocoulometry. - Highlights: • WO{sub 3} thin films were fabricated using an air-spray based deposition system at room temperature under low-vacuum conditions. • Dry WO{sub 3} particles were directly deposited on FTO and ITO glasses by using a low-cost deposition system. • The FTO glass based WO{sub 3} film showed the optical contrast of 50% at a wavelength of 800 nm.

  9. Study on infrared differential thermal non-destructive testing technology of the permeability of hot mix asphalt pavements

    Science.gov (United States)

    Wang, Duanyi; Shi, Jicun

    2017-06-01

    In order to non-destructive test (NDT) the permeability coefficient of hot mix asphalt (HMA) pavements fast, A methodology for assessing the permeability coefficient was proposed by infrared differential thermal testing of pavement after rain. The relationship between permeability coefficient and air voids of HMA specimen deter-mined. Finite element method (FEM) models were built to calculate the surface temperature difference with different exposure time after precipitation. Simulated solar radiation source and fully saturated plate specimens were set in laboratory, tests verify that the different exposure time the specimen surface temperature difference. Infrared differential thermal detection permeable pavement hardware and corresponding software developed. Based on many test results, the evaluation index and criteria of permeability coefficient of HMA pavements tested by infrared differential thermal were developed. The results showed that: There is correlation between air voids and permeability coefficient of HMA specimen. Permeability coefficient of HMA pavements can be determined by different surface temperature at different exposure time. 9:00 am - 14:00 pm is the best time to detect permeability coefficient by infrared differential thermal NDT. Permeable asphalt pavement permeability can be achieved by infrared detector quickly and continuously, a lane testing; Per the permeable assessment criteria, in-place pavements permeability coefficients can be accurately evaluated.

  10. Novel highly sensitive and wearable pressure sensors from conductive three-dimensional fabric structures

    Science.gov (United States)

    Li, Jianfeng; Xu, Bingang

    2015-12-01

    Pressure sensors based on three-dimensional fabrics have all the excellent properties of the textile substrate: excellent compressibility, good air permeability and moisture transmission ability, which will find applications ranging from the healthcare industry to daily usage. In this paper, novel pressure sensors based on 3D spacer fabrics have been developed by a proposed multi-coating method. By this coating method, carbon black can be coated uniformly on the silicon elastomer which is attached and slightly cured on the 3D fabric surface beforehand. The as-made pressure sensors have good conductivity and can measure external pressure up to 283 kPa with an electrical conductivity range of 9.8 kΩ. The sensitivity of 3D fabric pressure sensors can be as high as 50.31×10-3 kPa-1, which is better than other textile based pressure sensors. When the as-made sensors are pressed, their electrical resistance will decrease because of more conductive connections and bending of fibers in the spacer layer. The sensing mechanism related to fiber bending has been explored by using an equivalent resistance model. The newly developed 3D sensor devices can be designed to exhibit different sensing performances by simply changing the structures of fabric substrate, which endows this kind of device more flexibility in related applications.

  11. Methods to Measure Water Permeability.

    Science.gov (United States)

    Solenov, Evgeniy I; Baturina, Galina S; Katkova, Liubov E; Zarogiannis, Sotirios G

    2017-01-01

    Water permeability is a key feature of the cell plasma membranes and it has seminal importance for a number of cell functions such as cell volume regulation, cell proliferation, cell migration, and angiogenesis to name a few. The transport of water occurs mainly through plasma membrane water channels , the aquaporins, who have very important function in physiological and pathophysiological states. Due to the above the experimental assessment of the water permeability of cells and tissues is necessary. The development of new methodologies of measuring water permeability is a vibrant scientific field that constantly develops during the past three decades along with the advances in imaging mainly. In this chapter we describe and critically assess several methods that have been developed for the measurement of water permeability both in living cells as well as in tissues with a focus in the first category.

  12. Geothermal Permeability Enhancement - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Joe Beall; Mark Walters

    2009-06-30

    The overall objective is to apply known permeability enhancement techniques to reduce the number of wells needed and demonstrate the applicability of the techniques to other undeveloped or under-developed fields. The Enhanced Geothermal System (EGS) concept presented in this project enhances energy extraction from reduced permeability zones in the super-heated, vapor-dominated Aidlin Field of the The Geysers geothermal reservoir. Numerous geothermal reservoirs worldwide, over a wide temperature range, contain zones of low permeability which limit the development potential and the efficient recovery of heat from these reservoirs. Low permeability results from poorly connected fractures or the lack of fractures. The Enhanced Geothermal System concept presented here expands these technologies by applying and evaluating them in a systematic, integrated program.

  13. Deposited metamaterial thin film with negative refractive index and permeability in the visible regime.

    Science.gov (United States)

    Jen, Yi-Jun; Chen, Chih-Hui; Yu, Ching-Wei

    2011-03-15

    Thin films are fabricated from arrays of silver nanorods with thicknesses of 160 nm and 200 nm, to function as a metamaterial. The negative refractive index and negative permeability are retrieved from measured reflection and transmission coefficients using walk-off interferometer in the visible regime. A negative-index-material thin film with negative permittivity or (and) permeability can be produced by glancing angle deposition.

  14. Use of Interface Treatment to Reduce Emissions from Residuals in Lower Permeability Zones to Groundwater flowing Through More Permeable Zones (Invited)

    Science.gov (United States)

    Johnson, P.; Cavanagh, B.; Clifton, L.; Daniels, E.; Dahlen, P.

    2013-12-01

    Many soil and groundwater remediation technologies rely on fluid flow for contaminant extraction or reactant delivery (e.g., soil vapor extraction, pump and treat, in situ chemical oxidation, air sparging, enhanced bioremediation). Given that most unconsolidated and consolidated settings have permeability contrasts, the outcome is often preferential treatment of more permeable zones and ineffective treatment of the lower permeability zones. When this happens, post-treatment contaminant emissions from low permeability zone residuals can cause unacceptable long-term impacts to groundwater in the transmissive zones. As complete remediation of the impacted lower permeability zones may not be practicable with conventional technologies, one might explore options that lead to reduction of the contaminant emissions to acceptable levels, rather than full remediation of the lower permeability layers. This could be accomplished either by creating a sustained emission reaction/attenuation zone at the high-low permeability interface, or by creating a clean soil zone extending sufficiently far into the lower permeability layer to cause the necessary reduction in contaminant concentration gradient and diffusive emission. These options are explored in proof-of-concept laboratory-scale physical model experiments. The physical models are prepared with two layers of contrasting permeability and either dissolved matrix storage or nonaqueous phase liquid (NAPL) in the lower permeability layer. A dissolved oxidant is then delivered to the interface via flow across the higher permeability layer and changes in contaminant emissions from the low permeability zone are monitored before, during, and after oxidant delivery. The use of three oxidants (dissolved oxygen, hydrogen peroxide and sodium persulfate) for treatment of emissions from petroleum hydrocarbon residuals is examined.

  15. Preparation and oxygen permeability of Bi26Mo10O69 porous layer modified ionic-electronic mixed conductor on air side%Bi26Mo10O69多孔涂层空气侧改性混合离子导体的制备及其增进透氧性能

    Institute of Scientific and Technical Information of China (English)

    王太和; 李榕; 甄强; 程琳

    2016-01-01

    Bi26Mo10O69 nanopowder was prepared by hydrothermal method and used as a surface modification material for oxygen separation membrane to enhance oxygen permeability. Thermal decomposition behavior and phase variation of the precursor were investigated by thermal analyzer (TG-DSC) and high-temperature X-ray diffraction (HT-XRD). Bi26Mo10O69 porous layer was coated on the air side of BaCo0.7Fe0.2Nb0.1O3−δ (BCFN) oxygen permeable membrane by dipping method. In the partial oxidation experiment of coke oven gas (COG), the Bi26Mo10O69-coated BCFN membrane exhibits higher oxygen permeability and CH4 conversion than the uncoated BCFN membrane. When the thickness of BCFN membrane was 1 mm and the COG and air fluxes were 120 and 100 mL/min, the oxygen permeation flux reached 16.48 mL/(min·cm2) at 875 °C, which was 16.96% higher than the uncoated BCFN membrane. Therefore, Bi26Mo10O69 porous layer on the air side will be promising modification coating on the oxygen permeability of BCFN membrane.%通过水热法合成Bi26Mo10O69纳米粉体,并作为表面改性材料用于提高氧分离膜的透氧性能。通过TG−DSC和高温XRD(HT-XRD)对前驱体的热分解行为及物相变化进行研究。采用浸渍法在BaCo0.7Fe0.2Nb0.1O3−δ(BCFN)的空气侧涂覆Bi26Mo10O69多孔涂层。在焦炉煤气(COG)的部分氧化重整实验中,涂覆Bi26Mo10O69多孔涂层的BCFN 膜的透氧量和CH4转化率均高于无涂层的BCFN 膜。当BCFN透氧膜厚度为1mm,COG流量和空气流量分别为120 mL/min 和100 mL/min 时,875°C透氧速率达到16.48 mL/(min·cm2),比无涂层的BCFN 膜高16.96%。因此,空气侧Bi26Mo10O69多孔涂层有望作为改性涂层提高BCFN膜的透氧性能。

  16. Digital fabrication

    CERN Document Server

    2012-01-01

    The Winter 2012 (vol. 14 no. 3) issue of the Nexus Network Journal features seven original papers dedicated to the theme “Digital Fabrication”. Digital fabrication is changing architecture in fundamental ways in every phase, from concept to artifact. Projects growing out of research in digital fabrication are dependent on software that is entirely surface-oriented in its underlying mathematics. Decisions made during design, prototyping, fabrication and assembly rely on codes, scripts, parameters, operating systems and software, creating the need for teams with multidisciplinary expertise and different skills, from IT to architecture, design, material engineering, and mathematics, among others The papers grew out of a Lisbon symposium hosted by the ISCTE-Instituto Universitario de Lisboa entitled “Digital Fabrication – A State of the Art”. The issue is completed with four other research papers which address different mathematical instruments applied to architecture, including geometric tracing system...

  17. The generation and evolution of anisotropic gas-permeability during viscous deformation in conduit-filling ignimbrites

    Science.gov (United States)

    Kolzenburg, Stephan; Russell, Kelly

    2015-04-01

    Gas-permeability plays a governing role in the pre-explosive pressurization of volcanic edifices. Pressurization may only occur once the total volume flux of gases emitted by an underlying magmatic or hydrothermal source exceeds the flow capacity of the permeable pathways present in the edifice. We have measured the physical properties (strain, porosity, permeability and ultrasonic wave velocities) of breadcrust bombs recovered from the deposits of the 2350 B.P. eruption of Mt Meager, BC, Canada. These rocks represent a conduit-infilling pyroclastic breccia that underwent various degrees of welding and deformation and present a remarkable opportunity to constrain the nature and timescale of mechanical processes operating within explosive volcanic conduits during repose periods between eruptive cycles. Here we present data from permeability measurements along the directions of maximum and minimum shortening which help quantifying the effect of vesicle microstructure on permeability. Permeability is measured by applying a range of confining pressures (between 3.4 and 17.2 MPa) to each sample and imposing a constant head (of 0.2 to 3.5 MPa) across the sample. The permeability is then determined using a modified version of Darcy's law applicable to compressible fluids. These rocks display a profound directionality in the measured physical properties resulting from the deformation-induced fabric. For all samples the permeability across the elongation fabric is highly correlated to the sample porosity whereas along the elongation fabric there is little effect of porosity on permeability. At porosity values of about 20% the permeability seems to reach a minimum at 10-16 m2 and does not change significantly with further reduction of porosity. Further, the effect of confining pressure on the permeability of these samples appears to be more pronounced across the elongation fabric than along the elongation fabric. The deformation fabric has a significant effect on the gas-permeability

  18. Photovoltaic fabrics

    Science.gov (United States)

    2015-04-22

    during wire fabrication. Weaving was demonstrated for both military-type nylon -cotton blend (NYCO) warp fibers and cotton-polyester warp fibers. A...Lowell, MA 01852 14. ABSTRACT This report describes a project to improve photovoltaic fabrics. It had four objectives: 1) Efficiency – make PV wires on...a continuous basis that exhibit 7% efficiency; 2) Automated Welding – demonstrate an automated means of interconnecting the electrodes of one wire

  19. Differential Capillary Effect Model of Fabric and Its Application

    Institute of Scientific and Technical Information of China (English)

    王其; 冯勋伟

    2003-01-01

    The concept of the differential capillary effect was presented by foreign scholars several years ago, and the principle was used to design sportswear fabrics with good wet permeability and good drying functions for famous sports teams. Because the differential capillary effect model was not established in theory,it was impossible to fulfill the best functions. In this paper, by setting up the differential capillary effect of fabric, the factors to influence wet permeability and drying functions of the model is discussed in theory, and the means to optimize the design of the fabric is presented and proven practically by the experiment. The optimum fabric with good permeability and good drying functions can be designed using the model at last.

  20. Bentonite Permeability at Elevated Temperature

    Directory of Open Access Journals (Sweden)

    Katherine A. Daniels

    2017-01-01

    Full Text Available Repository designs frequently favour geological disposal of radioactive waste with a backfill material occupying void space around the waste. The backfill material must tolerate the high temperatures produced by decaying radioactive waste to prevent its failure or degradation, leading to increased hydraulic conductivity and reduced sealing performance. The results of four experiments investigating the effect of temperature on the permeability of a bentonite backfill are presented. Bentonite is a clay commonly proposed as the backfill in repository designs because of its high swelling capacity and very low permeability. The experiments were conducted in two sets of purpose-built, temperature controlled apparatus, designed to simulate isotropic pressure and constant volume conditions within the testing range of 4–6 MPa average effective stress. The response of bentonite during thermal loading at temperatures up to 200 °C was investigated, extending the previously considered temperature range. The results provide details of bentonite’s intrinsic permeability, total stress, swelling pressure and porewater pressure during thermal cycles. We find that bentonite’s hydraulic properties are sensitive to thermal loading and the type of imposed boundary condition. However, the permeability change is not large and can mostly be accounted for by water viscosity changes. Thus, under 150 °C, temperature has a minimal impact on bentonite’s hydraulic permeability.

  1. Experimental investigation of turbulent flow over a permeable rough wall

    Science.gov (United States)

    Kim, T.; Blois, G.; Best, J.; Christensen, K. T.

    2015-12-01

    Permeable walls are encountered in a variety of geophysical flows, including alluvial river beds, canopies and urban environments. Permeable walls possess very different boundary conditions as compared to classic impermeable walls (i.e. the slip condition and penetration of flow into the bed). Permeability allows flow interactions across the wall interface, resulting in notable mass, momentum and energy exchange. Such exchange takes place in the so-called transition layer and often occurs through turbulent flow mechanisms. It is increasingly recognized that turbulence plays a key role in a number of important natural functions, including biogeochemical as well as geomorphological processes. However, the flow physics of the transition layer are still poorly understood due to a lack of quantitative investigation of these permeable systems within which physical and optical access are severely compromised. This is particularly true for state-of-the-art flow measurement techniques such as particle image velocimetry (PIV) that require unaberrated optical access to the measurement locations. To overcome optical limitations, a refractive index matching (RIM) technique was employed herein to gain full optical access to the transition layer. Sodium Iodide aqueous solution (63% by weight and RI ~ 1.496 at 20°C) served as a working fluid, and an acrylic resin (RI ~ 1.499) was chosen for fabricating wall models. Measurements were performed using high-resolution planar PIV in different configurations to characterize the turbulent boundary layer and the transition layer. The wall models comprised uniform spheres packed in a cubic arrangement, and two cases were modeled - impermeable and permeable walls that were both rough. To eliminate the effect of roughness, and thus isolate the effect of permeability, the surface roughness of the two wall models was kept identical. This allowed us to obtain a more meaningful comparison and highlight the impact of wall permeability in natural

  2. Adaptability study of air-foam flooding technique in shallow ultra-low permeability and low temperature reservoir%空气泡沫调驱技术在浅层特低渗透低温油藏的适应性研究

    Institute of Scientific and Technical Information of China (English)

    杨红斌; 蒲春生; 吴飞鹏; 张新春; 杨兴利; 李星红; 郑黎明

    2012-01-01

    空气泡沫调驱技术综合了空气驱和泡沫驱的优点,可提高波及系数和驱油效率,在中高温油藏中取得了很好的应用效果,但是在浅层特低渗透低温油藏中的应用较少.根据陕北油区特低渗透油藏地质特征,以甘谷驿油田唐114井区为例,通过理论研究、室内实验和现场试验研究了空气泡沫调驱技术在浅层特低渗透低温油藏的适应性.结果表明:室内实验低渗透层中的原油被明显启动,驱油效率由水驱阶段的8.33%升高到50.55%;矿场试验井组含水率由98%下降至73%,产液量由3m3/d降至0.8 m3/d,平均单井产油量由0.05 m3/d增至0.2m3/d.空气泡沫调驱技术在甘谷驿油田具有较强的适应性,可大幅度提高油田采收率,对同类油藏的增油控水具有一定的借鉴作用.%The air-foam flooding technique which combines the advantage of air injection displacement and foam flooding has enhanced the sweep efficiency and oil displacement efficiency and achieved well application effect in middle-high temperature reservoirs, however, it is less applicable in shallow ultra -low permeability and low temperature reservoirs. According to the reservoir characteristics of ultra-low permeability reservoirs in Northern Shaanxi, we analyzed the suitability of the air-foam flooding technique in these reservoirs through theoretical studies, laboratory test and field test, taking Tang 114 well area in Ganguyi oil field as an example. The results show that the crude oil in low permeability layers is obvious motivated in the lab experiment, the oil displacement efficiency rises from 8. 33% to 50. 55% , the water content of the field test well group decreased from 98% to 73% , the daily fluid production rate dropped 2 m , and the daily oil production is 6 times of that of the original. The air-foam flooding technique has strong suitability in Ganguyi oil field and oil recovery can be greatly enhanced. It has certain reference

  3. Permeability of Aluminium Foams Produced by Replication Casting

    Directory of Open Access Journals (Sweden)

    Maxim L. Cherny

    2012-12-01

    Full Text Available The replication casting process is used for manufacturing open-pore aluminum foams with advanced performances, such as stability and repeatability of foam structure with porosity over 60%. A simple foam structure model based on the interaction between sodium chloride solid particles poorly wetted by melted aluminum, which leads to the formation of air pockets (or “air collars”, is proposed for the permeability of porous material. The equation for the minimum pore radius of replicated aluminum foam is derived. According to the proposed model, the main assumption of the permeability model consists in a concentration of flow resistance in a circular aperture of radius rmin. The permeability of aluminum open-pore foams is measured using transformer oil as the fluid, changing the fractions of initial sodium chloride. Measured values of minimum pore size are close to theoretically predicted ones regardless of the particle shape. The expression for the permeability of replicated aluminum foam derived on the basis of the “bottleneck” model of porous media agrees well with the experimental data. The obtained data can be applied for commercial filter cells and pneumatic silencers.

  4. Vacuum-driven power-free microfluidics utilizing the gas solubility or permeability of polydimethylsiloxane (PDMS).

    Science.gov (United States)

    Xu, Linfeng; Lee, Hun; Jetta, Deekshitha; Oh, Kwang W

    2015-10-21

    Suitable pumping methods for flow control remain a major technical hurdle in the path of biomedical microfluidic systems for point-of-care (POC) diagnostics. A vacuum-driven power-free micropumping method provides a promising solution to such a challenge. In this review, we focus on vacuum-driven power-free microfluidics based on the gas solubility or permeability of polydimethylsiloxane (PDMS); degassed PDMS can restore air inside itself due to its high gas solubility or gas permeable nature. PDMS allows the transfer of air into a vacuum through it due to its high gas permeability. Therefore, it is possible to store or transfer air into or through the gas soluble or permeable PDMS in order to withdraw liquids into the embedded dead-end microfluidic channels. This article provides a comprehensive look at the physics of the gas solubility and permeability of PDMS, a systematic review of different types of vacuum-driven power-free microfluidics, and guidelines for designing solubility-based or permeability-based PDMS devices, alongside existing applications. Advanced topics and the outlook in using micropumping that utilizes the gas solubility or permeability of PDMS will be also discussed. We strongly recommend that microfluidics and lab-on-chip (LOC) communities harness vacuum energy to develop smart vacuum-driven microfluidic systems.

  5. NCSX Vacuum Vessel Fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Viola, M. E.; Brown, T.; Heitzenroeder, P.; Malinowski, F.; Reiersen, W.; Sutton, L.; Goranson, P.; Nelson, B.; Cole, M.; Manuel, M.; McCorkle, D.

    2005-10-07

    The National Compact Stellarator Experiment (NCSX) is being constructed at the Princeton Plasma Physics Laboratory (PPPL) in conjunction with the Oak Ridge National Laboratory (ORNL). The goal of this experiment is to develop a device which has the steady state properties of a traditional stellarator along with the high performance characteristics of a tokamak. A key element of this device is its highly shaped Inconel 625 vacuum vessel. This paper describes the manufacturing of the vessel. The vessel is being fabricated by Major Tool and Machine, Inc. (MTM) in three identical 120º vessel segments, corresponding to the three NCSX field periods, in order to accommodate assembly of the device. The port extensions are welded on, leak checked, cut off within 1" of the vessel surface at MTM and then reattached at PPPL, to accommodate assembly of the close-fitting modular coils that surround the vessel. The 120º vessel segments are formed by welding two 60º segments together. Each 60º segment is fabricated by welding ten press-formed panels together over a collapsible welding fixture which is needed to precisely position the panels. The vessel is joined at assembly by welding via custom machined 8" (20.3 cm) wide spacer "spool pieces." The vessel must have a total leak rate less than 5 X 10-6 t-l/s, magnetic permeability less than 1.02μ, and its contours must be within 0.188" (4.76 mm). It is scheduled for completion in January 2006.

  6. Simple fabrication of air-stable black phosphorus heterostructures with large-area hBN sheets grown by chemical vapor deposition method

    Science.gov (United States)

    Sinha, Sapna; Takabayashi, Yuya; Shinohara, Hisanori; Kitaura, Ryo

    2016-09-01

    We have developed a facile and general method to passivate thin black phosphorus (BP) flakes with large-area high-quality monolayer hexagonal boron nitride (hBN) sheets grown by the chemical vapor deposition (CVD) method. In spite of the one-atom-thick structure, the high-quality CVD-grown monolayer hBN has proven to be useful to prevent the degradation of thin BP flakes exfoliated on substrates. Mechanically exfoliated BP flakes prepared on a Si substrate are covered by the monolayer hBN sheet to preserve (otherwise unstable) atomic layered BP flakes from degradation. The present technique can generally be applied to fabricating BP-based electronic devices with much easiness.

  7. Gravity Current in Horizontal Porous Media with A Permeability Gradient

    Science.gov (United States)

    Zheng, Zhong; Tsai, Peichun; Al-Housseiny, Talal; Stone, Howard; Complex Fluid Group Team

    2011-11-01

    We study the influence of a power-law porosity and permeability gradient on the front propagation of a gravity current in an unconfined porous media. We neglect mass transfer and surface tension on the interface. A similarity solution is found for the propagating front, which is different from the homogeneous case. Experiments have been performed using liquid pushing air in a Hele-Shaw cell with a constant gradient in gap thickness in the vertical direction. We measure the speed of the front and the shape of the interface. We observe a third layer of trapped air in the region where the permeability is low, while it appears that the propagating front still satisfies the similarity solution with a modified coefficient. This work is supported by a funding from Carbon Mitigation Initiative at Princeton University

  8. Processing and Electromagnetic Shielding Properties of Multifunctional Metal Composite Knitted Fabric used as Socks

    Directory of Open Access Journals (Sweden)

    Yu Zhicai

    2016-01-01

    Full Text Available In this research, a type of bamboo charcoal polyester (BC-PET/antibacterial nylon(AN/stainless steel wire (SSW metal composite yarn was prepared with a hollow spindle spinning machine, which using the SSW as the core material, the BC-PET and AN as the outer and inner wrapped yarns, respectively. The wrapping numbers was set at 8.0turns/cm for the produced metal composite yarns. Furthermore, a type of plated knitted fabric was designed and produced by using the automatic jacquard knitting machine. The plated knitted fabric presents the BC-PET/AN/SSW metal composite yarn on the knitted fabric face and the crisscross-section polyester (CSP on the knit back. The effect of lamination numbers and angles on the electromagnetic shielding effectiveness (EMSE were discussed in this study. EMSE measurement showed that the lamination angles will influence the EMSE, but not affect the air permeability. Finally, a novel EM shielding socks was designed with the produced plated knitted fabric. Finally, the performance of thermal resistance and evaporation resistance was also test usingThe sweating guarded hot plate apparatus.

  9. Experimental research of the energy characteristics of a permeable thermoelement

    Directory of Open Access Journals (Sweden)

    Cherkez R. G.

    2012-06-01

    Full Text Available The construction of permeable thermoelement used for cooling and heating of gas or liquid flux has been designed. Energy characteristics of the semiconductor thermal element based on Bi—Te—Se—Sb materials have been presented. The results showed the possibility of ensuring the temperature difference of 5—15°С during cooling or heating of air, with the energy efficiency exceeding by 5—9% that of the traditional thermoelectric elements.

  10. Transfer-printing of active layers to achieve high quality interfaces in sequentially deposited multilayer inverted polymer solar cells fabricated in air.

    Science.gov (United States)

    Vohra, Varun; Anzai, Takuya; Inaba, Shusei; Porzio, William; Barba, Luisa

    2016-01-01

    Polymer solar cells (PSCs) are greatly influenced by both the vertical concentration gradient in the active layer and the quality of the various interfaces. To achieve vertical concentration gradients in inverted PSCs, a sequential deposition approach is necessary. However, a direct approach to sequential deposition by spin-coating results in partial dissolution of the underlying layers which decreases the control over the process and results in not well-defined interfaces. Here, we demonstrate that by using a transfer-printing process based on polydimethylsiloxane (PDMS) stamps we can obtain increased control over the thickness of the various layers while at the same time increasing the quality of the interfaces and the overall concentration gradient within the active layer of PSCs prepared in air. To optimize the process and understand the influence of various interlayers, our approach is based on surface free energy, spreading parameters and work of adhesion calculations. The key parameter presented here is the insertion of high quality hole transporting and electron transporting layers, respectively above and underneath the active layer of the inverted structure PSC which not only facilitates the transfer process but also induces the adequate vertical concentration gradient in the device to facilitate charge extraction. The resulting non-encapsulated devices (active layer prepared in air) demonstrate over 40% increase in power conversion efficiency with respect to the reference spin-coated inverted PSCs.

  11. Capillary permeability in adipose tissue

    DEFF Research Database (Denmark)

    Paaske, W P; Nielsen, S L

    1976-01-01

    of about 7 ml/100 g-min. This corresponds to a capillary diffusion capacity of 2.0 ml/100 g-min which is half the value reported for vasodilated skeletal muscle having approximately twice as great capillary surface area. Thus, adipose tissue has about the same capillary permeability during slight metabolic...

  12. Two-Scale Modeling Approach to Predict Permeability of Fibrous Media

    OpenAIRE

    Sudhakar Jaganathan; Behnam Pourdeyhimi, Ph.D.; Hooman V. Tafreshi, Ph.D.

    2008-01-01

    We previously demonstrated how one can develop a 3-D geometry to model the fibrous microstructure of a nonwoven fiberweb and use it to simulate its permeability at fiber level [1-6]. Developing 3-D models of most nonwoven fabrics (bonded fiberwebs), however, is cumbersome, as in the case of hydroentangled fabrics, for instance. In such cases, microscopic techniques are often used to generate 3-D images of the media’s microstructures. Nevertheless, whether the microstructure is modeled or obta...

  13. The relation among porosity, permeability, and specific surface of chalk from the Gorm field, Danish North Sea

    DEFF Research Database (Denmark)

    Jeanette, Mortensen; Engstrøm, Finn; Lind, Ida

    1998-01-01

    The origin to the difference in the relationship between permeability and porosity for Danian and Maastrichtian chalk from the Gorm field offshore Denmark has been investigated. The investigation was based on 300 sets of core data (He-expansion porosity and air permeability) from the well Gorm N-...... analytically from a simple porosity model and Poiseuilles law....

  14. Fabrication of a multi-walled carbon nanotube-deposited glass fiber air filter for the enhancement of nano and submicron aerosol particle filtration and additional antibacterial efficacy.

    Science.gov (United States)

    Park, Jae Hong; Yoon, Ki Young; Na, Hyungjoo; Kim, Yang Seon; Hwang, Jungho; Kim, Jongbaeg; Yoon, Young Hun

    2011-09-01

    We grew multi-walled carbon nanotubes (MWCNTs) on a glass fiber air filter using thermal chemical vapor deposition (CVD) after the filter was catalytically activated with a spark discharge. After the CNT deposition, filtration and antibacterial tests were performed with the filters. Potassium chloride (KCl) particles (pressure drop across the filter. When a pristine glass fiber filter that had no CNTs was used, the particle filtration efficiencies at particle sizes under 30 nm and near 500 nm were 48.5% and 46.8%, respectively. However, the efficiencies increased to 64.3% and 60.2%, respectively, when the CNT-deposited filter was used. The reduction in the number of viable cells was determined by counting the colony forming units (CFU) of each test filter after contact with the cells. The pristine glass fiber filter was used as a control, and 83.7% of the E. coli were inactivated on the CNT-deposited filter.

  15. Quantifying Evaporation in a Permeable Pavement System

    Science.gov (United States)

    Studies quantifying evaporation from permeable pavement systems are limited to a few laboratory studies and one field application. This research quantifies evaporation for a larger-scale field application by measuring the water balance from lined permeable pavement sections. Th...

  16. Fabrication Technology

    Energy Technology Data Exchange (ETDEWEB)

    Blaedel, K.L.

    1993-03-01

    The mission of the Fabrication Technology thrust area is to have an adequate base of manufacturing technology, not necessarily resident at Lawrence Livermore National Laboratory (LLNL), to conduct the future business of LLNL. The specific goals continue to be to (1) develop an understanding of fundamental fabrication processes; (2) construct general purpose process models that will have wide applicability; (3) document findings and models in journals; (4) transfer technology to LLNL programs, industry, and colleagues; and (5) develop continuing relationships with the industrial and academic communities to advance the collective understanding of fabrication processes. The strategy to ensure success is changing. For technologies in which they are expert and which will continue to be of future importance to LLNL, they can often attract outside resources both to maintain their expertise by applying it to a specific problem and to help fund further development. A popular vehicle to fund such work is the Cooperative Research and Development Agreement with industry. For technologies needing development because of their future critical importance and in which they are not expert, they use internal funding sources. These latter are the topics of the thrust area. Three FY-92 funded projects are discussed in this section. Each project clearly moves the Fabrication Technology thrust area towards the goals outlined above. They have also continued their membership in the North Carolina State University Precision Engineering Center, a multidisciplinary research and graduate program established to provide the new technologies needed by high-technology institutions in the US. As members, they have access to and use of the results of their research projects, many of which parallel the precision engineering efforts at LLNL.

  17. Fabrication Technology

    Energy Technology Data Exchange (ETDEWEB)

    Blaedel, K.L.

    1993-03-01

    The mission of the Fabrication Technology thrust area is to have an adequate base of manufacturing technology, not necessarily resident at Lawrence Livermore National Laboratory (LLNL), to conduct the future business of LLNL. The specific goals continue to be to (1) develop an understanding of fundamental fabrication processes; (2) construct general purpose process models that will have wide applicability; (3) document findings and models in journals; (4) transfer technology to LLNL programs, industry, and colleagues; and (5) develop continuing relationships with the industrial and academic communities to advance the collective understanding of fabrication processes. The strategy to ensure success is changing. For technologies in which they are expert and which will continue to be of future importance to LLNL, they can often attract outside resources both to maintain their expertise by applying it to a specific problem and to help fund further development. A popular vehicle to fund such work is the Cooperative Research and Development Agreement with industry. For technologies needing development because of their future critical importance and in which they are not expert, they use internal funding sources. These latter are the topics of the thrust area. Three FY-92 funded projects are discussed in this section. Each project clearly moves the Fabrication Technology thrust area towards the goals outlined above. They have also continued their membership in the North Carolina State University Precision Engineering Center, a multidisciplinary research and graduate program established to provide the new technologies needed by high-technology institutions in the US. As members, they have access to and use of the results of their research projects, many of which parallel the precision engineering efforts at LLNL.

  18. Comfort and Functional Properties of Far-Infrared/Anion-Releasing Warp-Knitted Elastic Composite Fabrics Using Bamboo Charcoal, Copper, and Phase Change Materials

    Directory of Open Access Journals (Sweden)

    Ting-Ting Li

    2016-02-01

    Full Text Available Elastic warp-knitted composite fabrics with far-infrared emissivity and an anion-releasing property were prepared using bamboo charcoal (BC, copper (Cu, and phase-change material (PCM. The functional composite fabric, which was composed of self-made complex yarns with various twisting degrees and material composition, were created using a rotor twister and ring-spinning technique. The fabric structure was diversified by the feeding modes of weft yarn into a crochet-knitting machine. The twist number of complex yarns was optimized by tensile tenacity, twist contraction, and hairiness, and analysis showed that twisting at 12 twists per inch produced the highest tensile tenacity and appropriate twist contraction and hairiness. Comfort evaluation showed that the elastic composite fabrics with BC weft yarns exhibited higher water–vapor transmission rate and air permeability, reaching 876 g/m2∙ day and 73.2 cm3/s/cm2, respectively. Three structures of composite fabric with various weft yarns had >0.85 ε far-infrared emissivity and 350–420 counts/cm3 anion amount. The prepared elastic warp-knitted fabrics can provide a comfortable, dry, and breathable environment to the wearer and can thus be applied as health-care textiles in the future.

  19. Tritium Permeability of Incoloy 800H and Inconel 617

    Energy Technology Data Exchange (ETDEWEB)

    Philip Winston; Pattrick Calderoni; Paul Humrickhouse

    2012-07-01

    Design of the Next Generation Nuclear Plant (NGNP) reactor and its high-temperature components requires information regarding the permeation of fission generated tritium and hydrogen product through candidate heat exchanger alloys. Release of fission-generated tritium to the environment and the potential contamination of the helium coolant by permeation of product hydrogen into the coolant system represent safety basis and product contamination issues. Of the three potential candidates for high-temperature components of the NGNP reactor design, only permeability for Incoloy 800H has been well documented. Hydrogen permeability data have been published for Inconel 617, but only in two literature reports and for partial pressures of hydrogen greater than one atmosphere, far higher than anticipated in the NGNP reactor. To support engineering design of the NGNP reactor components, the tritium permeability of Inconel 617 and Incoloy 800H was determined using a measurement system designed and fabricated at Idaho National Laboratory. The tritium permeability of Incoloy 800H and Inconel 617, was measured in the temperature range 650 to 950°C and at primary concentrations of 1.5 to 6 parts per million volume tritium in helium. (partial pressures of 10-6 atm)—three orders of magnitude lower partial pressures than used in the hydrogen permeation testing. The measured tritium permeability of Incoloy 800H and Inconel 617 deviated substantially from the values measured for hydrogen. This may be due to instrument offset, system absorption, presence of competing quantities of hydrogen, surface oxides, or other phenomena. Due to the challenge of determining the chemical composition of a mixture with such a low hydrogen isotope concentration, no categorical explanation of this offset has been developed.

  20. Tritium Permeability of Incoloy 800H and Inconel 617

    Energy Technology Data Exchange (ETDEWEB)

    Philip Winston; Pattrick Calderoni; Paul Humrickhouse

    2011-09-01

    Design of the Next Generation Nuclear Plant (NGNP) reactor and its high-temperature components requires information regarding the permeation of fission generated tritium and hydrogen product through candidate heat exchanger alloys. Release of fission-generated tritium to the environment and the potential contamination of the helium coolant by permeation of product hydrogen into the coolant system represent safety basis and product contamination issues. Of the three potential candidates for high-temperature components of the NGNP reactor design, only permeability for Incoloy 800H has been well documented. Hydrogen permeability data have been published for Inconel 617, but only in two literature reports and for partial pressures of hydrogen greater than one atmosphere, far higher than anticipated in the NGNP reactor. To support engineering design of the NGNP reactor components, the tritium permeability of Inconel 617 and Incoloy 800H was determined using a measurement system designed and fabricated at Idaho National Laboratory. The tritium permeability of Incoloy 800H and Inconel 617, was measured in the temperature range 650 to 950 C and at primary concentrations of 1.5 to 6 parts per million volume tritium in helium. (partial pressures of 10-6 atm) - three orders of magnitude lower partial pressures than used in the hydrogen permeation testing. The measured tritium permeability of Incoloy 800H and Inconel 617 deviated substantially from the values measured for hydrogen. This may be due to instrument offset, system absorption, presence of competing quantities of hydrogen, surface oxides, or other phenomena. Due to the challenge of determining the chemical composition of a mixture with such a low hydrogen isotope concentration, no categorical explanation of this offset has been developed.

  1. Different Methods of Predicting Permeability in Shale

    DEFF Research Database (Denmark)

    Mbia, Ernest Ncha; Fabricius, Ida Lykke; Krogsbøll, Anette

    Permeability is often very difficult to measure or predict in shale lithology. In this work we are determining shale permeability from consolidation tests data using Wissa et al., (1971) approach and comparing the results with predicted permeability from Kozeny’s model. Core and cuttings materials...

  2. Single-Step Fabrication Using a Phase Inversion Method of Poly(vinylidene fluoride) (PVDF) Activated Carbon Air Cathodes for Microbial Fuel Cells

    KAUST Repository

    Yang, Wulin

    2014-10-14

    Air cathodes used in microbial fuel cells (MFCs) need to have high catalytic activity for oxygen reduction, but they must also be easy to manufacture, inexpensive, and watertight. A simple one-step, phase inversion process was used here to construct an inexpensive MFC cathode using a poly(vinylidene fluoride) (PVDF) binder and an activated carbon catalyst. The phase inversion process enabled cathode preparation at room temperatures, without the need for additional heat treatment, and it produced for the first time a cathode that did not require a separate diffusion layer to prevent water leakage. MFCs using this new type of cathode produced a maximum power density of 1470 ± 50 mW m–2 with acetate as a substrate, and 230 ± 10 mW m–2 with domestic wastewater. These power densities were similar to those obtained using cathodes made using more expensive materials or more complex procedures, such as cathodes with a polytetrafluoroethylene (PTFE) binder and a poly(dimethylsiloxane) (PDMS) diffusion layer, or a Pt catalyst. Even though the PVDF cathodes did not have a diffusion layer, they withstood up to 1.22 ± 0.04 m of water head (∼12 kPa) without leakage, compared to 0.18 ± 0.02 m for cathodes made using PTFE binder and PDMS diffusion layer. The cost of PVDF and activated carbon ($3 m–2) was less than that of the stainless steel mesh current collector ($12 m–2). PVDF-based AC cathodes therefore are inexpensive, have excellent performance in terms of power and water leakage, and they can be easily manufactured using a single phase inversion process at room temperature.

  3. Characterization of preform permeability and flow behavior for liquid composite molding

    Science.gov (United States)

    Sommerlot, Stephen Joseph

    Preform characterization is an important step in the processing of high-performance parts with liquid composite molding. A better understanding of preform compressibility and permeability creates more accurate process models, ultimately leading to high-quality finished composites. Without characterization, mold design and processing parameters are subject to guess-work and ad hoc optimization methods, which can result in poor infusions and inconsistent part quality. In this study, a complex architecture fiber reinforcement was characterized in compaction and permeability for liquid composite molding. Preforms of a four-harness satin carbon fabric were assembled with and without a novel inter-layer tackifier for experimentation. Compaction and permeability were measured to investigate the effects of the tackifier system, debulking, preform layup, and other processing parameters. Permeability and flow behavior was measured through saturated and unsaturated techniques, including investigations of fluid effects and high-flow rate infusions. The tackifier was seen to decrease permeability in both saturated and unsaturated cases, while notably influencing the orientation of first principal permeability. Tackified preforms also displayed a sensitivity to fluid type that non-tackified samples did not. Experimentally derived permeability was also used to generate numerical mold fill simulations of radially injected infusions, which produced favorable results.

  4. Permeability equipment for porous friction surfaces

    Science.gov (United States)

    Standiford, D. L.; Graul, R. A.; Lenke, L. R.

    1985-04-01

    Hydroplaning is the loss of traction between tires and pavement due to the presence of a layer of water. This loss of traction can result in loss of vehicle control. A porous friction surface (PFS) applied over an existing pavement permits the water to drain laterally and vertically away from the tire path, effectively lowering hydroplaning potential. Equipment used to measure pavement drainage (permeability) is discussed with respect to usage on porous friction surface. Background information on hydroplaning, flow theory, and PFS field performance as they are affected by permeability are also presented. Two dynamic test devices and four static devices are considered for measuring PFS permeability. Permeability tests are recommended to measure PFS permeability for maintenance purposes and construction control. Dynamic devices cited could possibly estimate hydroplaning potential; further research must be done to determine this. Permeability devices cannot be used to accurately estimate friction of a pavement surface, however, decreased permeability of a pavement infers a decrease in friction.

  5. On the permeability of fractal tube bundles

    CERN Document Server

    Zinovik, I

    2011-01-01

    The permeability of a porous medium is strongly affected by its local geometry and connectivity, the size distribution of the solid inclusions and the pores available for flow. Since direct measurements of the permeability are time consuming and require experiments that are not always possible, the reliable theoretical assessment of the permeability based on the medium structural characteristics alone is of importance. When the porosity approaches unity, the permeability-porosity relationships represented by the Kozeny-Carman equations and Archie's law predict that permeability tends to infinity and thus they yield unrealistic results if specific area of the porous media does not tend to zero. The goal of this paper is an evaluation of the relationships between porosity and permeability for a set of fractal models with porosity approaching unity and a finite permeability. It is shown that the two-dimensional foams generated by finite iterations of the corresponding geometric fractals can be used to model poro...

  6. Rose-like monodisperse bismuth subcarbonate hierarchical hollow microspheres: One-pot template-free fabrication and excellent visible light photocatalytic activity and photochemical stability for NO removal in indoor air

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Fan [College of Environmental and Biological Engineering, Chongqing Technology and Business University, Chongqing, 400067 (China); Department of Civil and Structural Engineering, Research Center for Environmental Technology and Management, The Hong Kong Polytechnic University, Hong Kong (China); Department of Environmental Engineering, Zhejiang University, Hangzhou 310027 (China); Lee, S.C., E-mail: ceslee@polyu.edu.hk [Department of Civil and Structural Engineering, Research Center for Environmental Technology and Management, The Hong Kong Polytechnic University, Hong Kong (China); Wu, Zhongbiao [Department of Environmental Engineering, Zhejiang University, Hangzhou 310027 (China); Huang, Yu [Department of Civil and Structural Engineering, Research Center for Environmental Technology and Management, The Hong Kong Polytechnic University, Hong Kong (China); Fu, Min [College of Environmental and Biological Engineering, Chongqing Technology and Business University, Chongqing, 400067 (China); Ho, Wing-Kei [Nano and Advanced Materials Institute Limited, Hosted by The Hong Kong University of Science and Technology, Hong Kong (China); Zou, Shichun [School of Marine Sciences, Sun Yat-Sen University, Guangzhou, 510275 (China); Wang, Bo [Department of Civil and Structural Engineering, Research Center for Environmental Technology and Management, The Hong Kong Polytechnic University, Hong Kong (China)

    2011-11-15

    Graphical abstract: Rose-like monodisperse hierarchical nitrogen doped (BiO){sub 2}CO{sub 3} hollow microspheres fabricated by a one-pot template-free method exhibit excellent visible light photocatalytic activity and photochemical stability in the removal of NO in indoor air. The special hierarchical microstructure, the high charge separation efficiency and two-band-gap structure in all contribute to the outstanding photocatalytic performance. Highlights: {yields} Rose-like monodisperse hierarchical (BiO){sub 2}CO{sub 3} hollow microspheres are fabricated. {yields} The (BiO){sub 2}CO{sub 3} microspheres are self-assembled of single-crystalline nanosheets. {yields} Nitrogen is in situ doped into the lattice of hierarchical (BiO){sub 2}CO{sub 3} microspheres. {yields} The (BiO){sub 2}CO{sub 3} microspheres exhibit outstanding visible light activity for NO removal. {yields} The (BiO){sub 2}CO{sub 3} microspheres also exhibit high photochemical stability. - Abstract: Rose-like monodisperse hierarchical (BiO){sub 2}CO{sub 3} hollow microspheres are fabricated by a one-pot template-free method for the first time based on hydrothermal treatment of ammonia bismuth citrate and urea in water. The microstructure and band structure of the as-prepared (BiO){sub 2}CO{sub 3} superstructure are characterized in detail by X-ray diffraction, Raman spectroscopy, Fourier transform-infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, N{sub 2} adsorption-desorption isotherms, X-ray photoelectron spectroscopy and UV-vis diffuse reflectance spectroscopy. The monodisperse hierarchical (BiO){sub 2}CO{sub 3} microspheres are constructed by the self-assembly of single-crystalline nanosheets. The aggregation of nanosheets result in the formation of three dimensional hierarchical framework containing mesopores and macropores, which is favorable for efficient transport of reaction molecules and harvesting of photo-energy. The result reveals the existence of

  7. Structural determinants of glomerular permeability.

    Science.gov (United States)

    Deen, W M; Lazzara, M J; Myers, B D

    2001-10-01

    Recent progress in relating the functional properties of the glomerular capillary wall to its unique structure is reviewed. The fenestrated endothelium, glomerular basement membrane (GBM), and epithelial filtration slits form a series arrangement in which the flow diverges as it enters the GBM from the fenestrae and converges again at the filtration slits. A hydrodynamic model that combines morphometric findings with water flow data in isolated GBM has predicted overall hydraulic permeabilities that are consistent with measurements in vivo. The resistance of the GBM to water flow, which accounts for roughly half that of the capillary wall, is strongly dependent on the extent to which the GBM surfaces are blocked by cells. The spatial frequency of filtration slits is predicted to be a very important determinant of the overall hydraulic permeability, in keeping with observations in several glomerular diseases in humans. Whereas the hydraulic resistances of the cell layers and GBM are additive, the overall sieving coefficient for a macromolecule (its concentration in Bowman's space divided by that in plasma) is the product of the sieving coefficients for the individual layers. Models for macromolecule filtration reveal that the individual sieving coefficients are influenced by one another and by the filtrate velocity, requiring great care in extrapolating in vitro observations to the living animal. The size selectivity of the glomerular capillary has been shown to be determined largely by the cellular layers, rather than the GBM. Controversial findings concerning glomerular charge selectivity are reviewed, and it is concluded that there is good evidence for a role of charge in restricting the transmural movement of albumin. Also discussed is an effect of albumin that has received little attention, namely, its tendency to increase the sieving coefficients of test macromolecules via steric interactions. Among the unresolved issues are the specific contributions of the

  8. The Membrane Permeability Outcome study.

    Science.gov (United States)

    Locatelli, Francesco; Cavalli, Andrea; Manzoni, Celestina; Pontoriero, Giuseppe

    2011-01-01

    Many observational studies have consistently shown that high-flux hemodialysis has positive effects on the survival and morbidity of uremic patients when compared with low-flux hemodialysis. However, the HEMO study, a randomized trial designed to evaluate the effect of membrane permeability on patient survival, showed only an 8% non-statistically significant reduction of mortality, albeit a secondary analysis suggested an advantage for high-flux membranes in certain patient subgroups. The prospective, randomized Membrane Permeability Outcome (MPO) study investigated the impact of membrane permeability on survival in incident hemodialysis patients who had low albumin (≤4 g/dl) and normal albumin ( >4 g/dl) as separate randomization groups. Patients with serum albumin ≤4 g/dl had significantly better survival rates in the high-flux group compared with the low-flux group (p = 0.032). Moreover, a post-hoc secondary analysis showed that high-flux membranes may significantly improve survival in diabetic patients. No difference was found in patients with normal albumin levels. Considering the increasing number of dialysis patients with low serum albumin levels and with diabetes, the relevance of the MPO study led to the publication of a position statement by the European Renal Best Practice Advisory Board. This board strongly recommended that high-flux hemodialysis should be used for high-risk patients and, with a lower degree of evidence, even also for low-risk subjects due to the substantial reduction in β(2)-microglobulin levels observed in the high-flux group. Copyright © 2011 S. Karger AG, Basel.

  9. Permeability of normal versus carious dentin.

    Science.gov (United States)

    Pashley, E L; Talman, R; Horner, J A; Pashley, D H

    1991-10-01

    Although a number of reports have been published demonstrating that carious dentin is less permeable than normal dentin, these reports have been qualitative rather than quantitative. The purpose of this in vitro study was to apply a quantitative technique to the study of the permeability of carious human teeth before and after excavation, before and after removal of the smear layer and before and after preparation of a control cavity of similar size and depth in normal dentin subjected to the same measurements, for comparative purposes. Dentin permeability was measured as a hydraulic conductance. The permeability values measured at each step in the protocol were expressed as a percent of the maximum permeability of both cavities, permitting each tooth the serve as its own control. Carious lesions exhibited a slight degree of permeability (2.3 +/- 0.6% of controls) which remained unchanged after excavation of the lesions. Removal of the smear layer in the excavated carious lesions increased the permeability significantly to 6.9 +/- 3.2%. Preparation of a control cavity of the same area and depth increased the permeability slightly. Removal of its smear layer increased the permeability of the dentin 91%. These results confirm previous qualitative studies that carious dentin, even after excavation and removal of the smear layer has a very low permeability.

  10. Seasonal evolution of snow permeability under equi-temperature and temperature-gradient conditions

    Directory of Open Access Journals (Sweden)

    F. Domine

    2013-12-01

    Full Text Available The permeability (K of snow to air flow affects the transfer of energy, water vapor and chemical species between the snow and the atmosphere. Yet today little is known about the temporal evolution of snow permeability as a function of metamorphic regime. Furthermore, our ability to simulate snow permeability over the seasonal evolution of a snowpack has not been tested. Here we have measured the evolution of snow permeability in a subarctic snowpack subject to high temperature-gradient (TG metamorphism. We have also measured the evolution of the same snowpack deposited over tables so that it evolved in the equi-temperature (ET regime. Permeability varies in the range 31 × 10−10 (ET regime to 650 × 10−10 m2 (TG regime. Permeability increases over time in TG conditions and decreases under ET conditions. Using measurements of density ρ and of specific surface area (SSA, from which the equivalent sphere radius r is determined, we show that the equation linking SSA, density ρ and permeability, K = 3.0 r2 e(−0.013 ρ (with K in m2, r in m and ρ in kg m−3 obtained in a previous study adequately predicts permeability values. The detailed snowpack model Crocus is used to simulate the physical properties of the TG and ET snowpacks. For the most part, all variables are well reproduced. Simulated permeabilities are up to a factor of two greater than measurements for depth hoar layers, which we attribute to snow microstructure and its aerodynamic properties. Finally, the large difference in permeabilities between ET and TG metamorphic regimes will impact atmosphere-snow energy and mass exchanges. These effects deserve consideration in predicting the effect of climate change on snow properties and snow–atmosphere interactions.

  11. Seasonal evolution of snow permeability under equi-temperature and temperature-gradient conditions

    Directory of Open Access Journals (Sweden)

    F. Domine

    2013-06-01

    Full Text Available The permeability K of snow to air flow affects the transfer of energy, water vapor and chemical species between the snow and the atmosphere. Yet today little is known of the temporal evolution of snow permeability as a function of metamorphic regime. Furthermore, our ability to simulate snow permeability over the seasonal evolution of a snowpack has not been tested. Here we have measured the evolution of snow permeability in a subarctic snowpack subject to high temperature-gradient (TG metamorphism. We have also measured the evolution of the same snowpack deposited over tables so that it evolved in the equi-temperature (ET regime. Permeability varies in the range 31 × 10–10 (ET regime to 650 × 10–10 m2 (TG regime. Permeability increases over time in TG conditions and decreases under ET conditions. Using measurements of density ρ and of specific surface area (SSA, from which the equivalent sphere radius r is determined, we show that the equation linking SSA, density ρ and permeability, K = 3.0 r2 e(–0.013 ρ (with K in m2, r in m and ρ in kg m−3 obtained in a previous study adequately predicts permeability values. The detailed snowpack model Crocus is used to simulate the physical properties of the TG and ET snowpacks. For the most part, all variables are well reproduced. Simulated permeabilities are up to a factor of two greater than measurements for depth hoar layers, which we attribute to snow microstructure, as the aerodynamic properties of hollow depth hoar crystals are different from those of spheres. Finally, the large difference in permeabilities between ET and TG metamorphic regimes will impact atmosphere-snow energy and mass exchanges and these effects deserve consideration in predicting the effect of climate change on snow properties and snow-atmosphere interactions.

  12. Microscale diffusion measurements and simulation of a scaffold with a permeable strut.

    Science.gov (United States)

    Lee, Seung Youl; Lee, Byung Ryong; Lee, Jongwan; Kim, Seongjun; Kim, Jung Kyung; Jeong, Young Hun; Jin, Songwan

    2013-10-10

    Electrospun nanofibrous structures provide good performance to scaffolds in tissue engineering. We measured the local diffusion coefficients of 3-kDa FITC-dextran in line patterns of electrospun nanofibrous structures fabricated by the direct-write electrospinning (DWES) technique using the fluorescence recovery after photobleaching (FRAP) method. No significant differences were detected between DWES line patterns fabricated with polymer supplied at flow rates of 0.1 and 0.5 mL/h. The oxygen diffusion coefficients of samples were estimated to be ~92%-94% of the oxygen diffusion coefficient in water based on the measured diffusion coefficient of 3-kDa FITC-dextran. We also simulated cell growth and distribution within spatially patterned scaffolds with struts consisting of either oxygen-permeable or non-permeable material. The permeable strut scaffolds exhibited enhanced cell growth. Saturated depths at which cells could grow to confluence were 15% deeper for the permeable strut scaffolds than for the non-permeable strut scaffold.

  13. Microscale Diffusion Measurements and Simulation of a Scaffold with a Permeable Strut

    Directory of Open Access Journals (Sweden)

    Songwan Jin

    2013-10-01

    Full Text Available Electrospun nanofibrous structures provide good performance to scaffolds in tissue engineering. We measured the local diffusion coefficients of 3-kDa FITC-dextran in line patterns of electrospun nanofibrous structures fabricated by the direct-write electrospinning (DWES technique using the fluorescence recovery after photobleaching (FRAP method. No significant differences were detected between DWES line patterns fabricated with polymer supplied at flow rates of 0.1 and 0.5 mL/h. The oxygen diffusion coefficients of samples were estimated to be ~92%–94% of the oxygen diffusion coefficient in water based on the measured diffusion coefficient of 3-kDa FITC-dextran. We also simulated cell growth and distribution within spatially patterned scaffolds with struts consisting of either oxygen-permeable or non-permeable material. The permeable strut scaffolds exhibited enhanced cell growth. Saturated depths at which cells could grow to confluence were 15% deeper for the permeable strut scaffolds than for the non-permeable strut scaffold.

  14. Polybenzimidazole-based mixed membranes with exceptional high water vapor permeability and selectivity

    KAUST Repository

    Akhtar, Faheem Hassan

    2017-09-13

    Polybenzimidazole (PBI), a thermal and chemically stable polymer, is commonly used to fabricate membranes for applications like hydrogen recovery at temperatures of more than 300 °C, fuel cells working in a highly acidic environment, and nanofiltration in aggressive solvents. This report shows for the first time use of PBI dense membranes for water vapor/gas separation applications. They showed an excellent selectivity and high water vapor permeability. Incorporation of inorganic hydrophilic titanium-based nano-fillers into the PBI matrix further increased the water vapor permeability and water vapor/N2 selectivity. The most selective mixed matrix membrane with 0.5 wt% loading of TiO2 nanotubes yielded a water vapor permeability of 6.8×104 Barrer and a H2O/N2 selectivity of 3.9×106. The most permeable membrane with 1 wt% loading of carboxylated TiO2 nanoparticles had a 7.1×104 Barrer water vapor permeability and a H2O/N2 selectivity of 3.1×106. The performance of these membranes in terms of water vapor transport and selectivity is among the highest reported ones. The remarkable ability of PBI to efficiently permeate water versus other gases opens the possibility to fabricate membranes for dehumidification of streams in harsh environments. This includes the removal of water from high temperature reaction mixtures to shift the equilibrium towards products.

  15. Two-Scale Modeling Approach to Predict Permeability of Fibrous Media

    Directory of Open Access Journals (Sweden)

    Sudhakar Jaganathan

    2008-06-01

    Full Text Available We previously demonstrated how one can develop a 3-D geometry to model the fibrous microstructure of a nonwoven fiberweb and use it to simulate its permeability at fiber level [1-6]. Developing 3-D models of most nonwoven fabrics (bonded fiberwebs, however, is cumbersome, as in the case of hydroentangled fabrics, for instance. In such cases, microscopic techniques are often used to generate 3-D images of the media’s microstructures. Nevertheless, whether the microstructure is modeled or obtained from 3-D imaging, extensive computational resources are required to use them in fluid flow simulations [7]. To circumvent this problem, a two-scale modeling approach is proposed here that allows us to simulate the entire thickness of a commercial fabric/filter on a personal computer. In particular, the microscale permeability of a hydroentangled nonwoven is computed using 3-D reconstructed microstructures obtained from Digital Volumetric Imaging (DVI. The resulting microstructural permeability tensors are then used in a macroscale porous model to simulate the flow through the material’s thickness and the calculation of its overall permeability.

  16. Steam-water relative permeability

    Energy Technology Data Exchange (ETDEWEB)

    Ambusso, W.; Satik, C.; Home, R.N. [Stanford Univ., CA (United States)

    1997-12-31

    A set of relative permeability relations for simultaneous flow of steam and water in porous media have been measured in steady state experiments conducted under the conditions that eliminate most errors associated with saturation and pressure measurements. These relations show that the relative permeabilities for steam-water flow in porous media vary approximately linearly with saturation. This departure from the nitrogen/water behavior indicates that there are fundamental differences between steam/water and nitrogen/water flows. The saturations in these experiments were measured by using a high resolution X-ray computer tomography (CT) scanner. In addition the pressure gradients were obtained from the measurements of liquid phase pressure over the portions with flat saturation profiles. These two aspects constitute a major improvement in the experimental method compared to those used in the past. Comparison of the saturation profiles measured by the X-ray CT scanner during the experiments shows a good agreement with those predicted by numerical simulations. To obtain results that are applicable to general flow of steam and water in porous media similar experiments will be conducted at higher temperature and with porous rocks of different wetting characteristics and porosity distribution.

  17. Vortex rings impinging on permeable boundaries

    Science.gov (United States)

    Mujal-Colilles, Anna; Dalziel, Stuart B.; Bateman, Allen

    2015-01-01

    Experiments with vortex rings impinging permeable and solid boundaries are presented in order to investigate the influence of permeability. Utilizing Particle Image Velocimetry, we compared the behaviour of a vortex ring impinging four different reticulated foams (with permeability k ˜ 26 - 85 × 10-8 m2) and a solid boundary. Results show how permeability affects the stretching phenomena of the vortex ring and the formation and evolution of the secondary vortex ring with opposite sign. Moreover, permeability also affects the macroscopic no-slip boundary condition found on the solid boundary, turning it into an apparent slip boundary condition for the most permeable boundary. The apparent slip-boundary condition and the flux exchange between the ambient fluid and the foam are jointly responsible for both the modified formation of the secondary vortex and changes on the vortex ring diameter increase.

  18. Clogging in permeable concrete: A review.

    Science.gov (United States)

    Kia, Alalea; Wong, Hong S; Cheeseman, Christopher R

    2017-05-15

    Permeable concrete (or "pervious concrete" in North America) is used to reduce local flooding in urban areas and is an important sustainable urban drainage system. However, permeable concrete exhibits reduction in permeability due to clogging by particulates, which severely limits service life. This paper reviews the clogging mechanism and current mitigating strategies in order to inform future research needs. The pore structure of permeable concrete and characteristics of flowing particulates influence clogging, which occurs when particles build-up and block connected porosity. Permeable concrete requires regular maintenance by vacuum sweeping and pressure washing, but the effectiveness and viability of these methods is questionable. The potential for clogging is related to the tortuosity of the connected porosity, with greater tortuosity resulting in increased potential for clogging. Research is required to develop permeable concrete that can be poured on-site, which produces a pore structure with significantly reduced tortuosity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Modelling of water permeability in cementitious materials

    DEFF Research Database (Denmark)

    Guang, Ye; Lura, Pietro; van Breugel, K.

    2006-01-01

    This paper presents a network model to predict the permeability of cement paste from a numerical simulation of its microstructure. Based on a linked list pore network structure, the effective hydraulic conductivity is estimated and the fluid flow is calculated according to the Hagen-Poiseuille law....... The pressure gradient at all nodes is calculated with the Gauss elimination method and the absolute permeability of the pore network is calculated directly from Darcy's law. Finally, the permeability model is validated by comparison with direct water permeability measurements. According to this model......, the predicted permeability of hydrating cement pastes is extremely sensitive to the particle size distribution of the cement and especially to the minimum size of the cement particles. Both in simulations and experiments, the permeability of cement pastes is mainly determined by the critical diameter...

  20. Calculation of High Frequency Complex Permeability of Carbonyl Iron Flakes in a Nomagnetic Matrix

    Institute of Scientific and Technical Information of China (English)

    WEN Fu-Sheng; QIAO Liang; YI Hai-Bo; ZHOU Dong; LI Fa-Shen

    2008-01-01

    The carbonyl iron flakes are fabricated by high-energy ball milling.The effective permeability is measured and calculated for the composite consisting of flakes embedded in a nonmagnetic matrix.The magnetic flakes with a shape anisotropy and random spatial distribution of normal direction are considered to calculate the complex permeability of magnetic flake materials.Its analytical model is derived from the Landau-Lifshitz- Gilbert equation and Bruggeman's effective medium theory.The calculated results agree well with the experiment.

  1. An Ethology of Urban Fabric(s)

    DEFF Research Database (Denmark)

    Fritsch, Jonas; Thomsen, Bodil Marie Stavning

    2014-01-01

    The article explores a non-metaphorical understanding of urban fabric(s), shifting the attention from a bird’s eye perspective to the actual, textural manifestations of a variety of urban fabric(s) to be studied in their real, processual, ecological and ethological complexity within urban life. We...... effectuate this move by bringing into resonance a range of intersecting fields that all deal with urban fabric(s) in complementary ways (interaction design and urban design activism, fashion, cultural theory, philosophy, urban computing)....

  2. An Ethology of Urban Fabric(s)

    DEFF Research Database (Denmark)

    Fritsch, Jonas; Thomsen, Bodil Marie Stavning

    2014-01-01

    The article explores a non-metaphorical understanding of urban fabric(s), shifting the attention from a bird’s eye perspective to the actual, textural manifestations of a variety of urban fabric(s) to be studied in their real, processual, ecological and ethological complexity within urban life. We...... effectuate this move by bringing into resonance a range of intersecting fields that all deal with urban fabric(s) in complementary ways (interaction design and urban design activism, fashion, cultural theory, philosophy, urban computing)....

  3. Vascular permeability in cerebral cavernous malformations.

    Science.gov (United States)

    Mikati, Abdul G; Khanna, Omaditya; Zhang, Lingjiao; Girard, Romuald; Shenkar, Robert; Guo, Xiaodong; Shah, Akash; Larsson, Henrik B W; Tan, Huan; Li, Luying; Wishnoff, Matthew S; Shi, Changbin; Christoforidis, Gregory A; Awad, Issam A

    2015-10-01

    Patients with the familial form of cerebral cavernous malformations (CCMs) are haploinsufficient for the CCM1, CCM2, or CCM3 gene. Loss of corresponding CCM proteins increases RhoA kinase-mediated endothelial permeability in vitro, and in mouse brains in vivo. A prospective case-controlled observational study investigated whether the brains of human subjects with familial CCM show vascular hyperpermeability by dynamic contrast-enhanced quantitative perfusion magnetic resonance imaging, in comparison with CCM cases without familial disease, and whether lesional or brain vascular permeability correlates with CCM disease activity. Permeability in white matter far (WMF) from lesions was significantly greater in familial than in sporadic cases, but was similar in CCM lesions. Permeability in WMF increased with age in sporadic patients, but not in familial cases. Patients with more aggressive familial CCM disease had greater WMF permeability compared to those with milder disease phenotype, but similar lesion permeability. Subjects receiving statin medications for routine cardiovascular indications had a trend of lower WMF, but not lesion, permeability. This is the first demonstration of brain vascular hyperpermeability in humans with an autosomal dominant disease, as predicted mechanistically. Brain permeability, more than lesion permeability, may serve as a biomarker of CCM disease activity, and help calibrate potential drug therapy.

  4. ABOUT CORRELATION BETWEEN THE PERCOLATION RATE OF MOISTURE THROUGH THE SEMI-PERMEABLE MEMBRANES AND THE STANDARD MEASUREMENTS OF THEIR PERMEABILITY OR EVAPORATIVE RESISTANCE

    Directory of Open Access Journals (Sweden)

    В.Б. Роганков

    2015-02-01

    Full Text Available A variety of test methods to estimate the water vapour transmission (WVT-rate of thin membranes do not provide, unfortunately, the reliable basis to compare the permeability of different fabrics. Their results are crucially dependent on the details and construction of experimental methodologies as well as on the accepted by the different authors conditions of measurement. In this work, we propose the universal approach and demonstrate its adequate realization to compare the transport properties of any semi-permeable membranes measured by the conventional test-methods. The purpose is to avoid any confusion in such procedure of comparison. We have analysed below the WVT-rates measured by six alternative test-methods, which have been applied step-by-step to six different fabrics. In opposite to the widespread search for a pair correlation between the above results obtained by any two methods we treat them, in total, for each fabric in terms of the reduced variables. This approach is based on the novel concept of the moisture percolation (MP-rate which combines the diffusion and convective contributions in a transport process. It leads to the well-established general estimates of the normalized WVT-rates measured by the standard test-methods. Another advantage of the developed approach is its thermodynamic consistency, which offers the appropriate fluctuation model to take into account the porosity of any semi-permeable membranes.

  5. Plastron Respiration Using Commercial Fabrics

    OpenAIRE

    2014-01-01

    A variety of insect and arachnid species are able to remain submerged in water indefinitely using plastron respiration. A plastron is a surface-retained film of air produced by surface morphology that acts as an oxygen-carbon dioxide exchange surface. Many highly water repellent and hydrophobic surfaces when placed in water exhibit a silvery sheen which is characteristic of a plastron. In this article, the hydrophobicity of a range of commercially available water repellent fabrics and polymer...

  6. Air Brush Fabricated Carbon Nanotube Supercapacitor Electrodes

    Science.gov (United States)

    2010-09-01

    dispersant is not contributing to the capacitance. The electrochemical, cyclic voltametry , measurements were made using a Keithley 4200 Semiconductor...reference electrode. The cyclic voltamogram (CV) was performed in potential ranges of anywhere between –0.9–0.5 V at scan rates ranging from 1–100 mV...Symbols, Acronyms, and Abbreviations AL aluminum CNT carbon nanotube Cu copper CV cyclic voltamogram ESEM environmental scanning electron microscope

  7. Fabrics for atopic dermatitis.

    Science.gov (United States)

    Mason, Rupert

    2008-01-01

    The type of fabric worn by sufferers from atopic dermatitis should not exacerbate the condition but, if possible, help to control it. Synthetic fabrics and wool tend to produce itching and irritate the skin. Cotton is traditionally recommended but its structure contains short fibres which expand and contract, causing a rubbing movement that can irritate delicate skin. Dyes used in cotton garments can increase the potential of a sensitivity reaction. Cotton is also prone to bacterial and fungal attack. Silk garments are often closely woven which impedes the flow of air, and some people are allergic to the sericin protein in silk. Published studies suggest that a specially treated silk material (DermaSilk), which is loosely knitted, has had the sericin removed and has a microbial agent (AEM 5772/5) permanently bonded to it, is well tolerated and has beneficial effects on the skin of children and adults with atopic dermatitis. Atopic dermatitis often becomes infected, commonly with Staphylococcus aureus. Some studies have investigated the use of clothing materials impregnated with substances such as silver, which has antimicrobial properties. However, these are still unproven and there are concerns about bacterial resistance and the local and environmental effects of silver. The use of the antimicrobial AEM 5772/5, which does not transfer to the skin of the patient, is a new development in the control of atopic dermatitis. Further studies are needed to determine whether an antimicrobial shield bonded to clothing material will reduce the colonisation of atopic skin by S. aureus.

  8. Shape-dependent microwave permeability of Fe3O4 nanoparticles: a combined experimental and theoretical study.

    Science.gov (United States)

    Yang, Yong; Yang, Yang; Xiao, Wen; Neo, Chye Poh; Ding, Jun

    2015-07-03

    Shape anisotropy is crucial for the microwave permeability of magnetic nanoparticles. In this work, we conduct a systematic study on the shape-dependent microwave permeability of magnetic nanoparticles. Three kinds of Fe3O4 nanoparticles with different geometric shapes (rod, disc, and octahedron) are fabricated by chemical methods and their permeability is investigated through both theoretical calculation and experiment. The results suggest that the rod could exhibit the highest resonance frequency (fr), while the lowest resonance frequency could be found in the octahedron. An opposite trend is observed in the initial permeability (μ0). In order to confirm the experimental permeability, we establish an improved LL-G model, which could take both the shape anisotropy and magnetic domain structure into account by introducing a local effective anisotropy field (Heff). The good agreement between the calculated and experimental permeability proves that the model can reproduce shape-dependent microwave permeability of magnetic nanoparticles. More importantly, no fitting process is involved in this model, enabling us to predict the permeability of magnetic nanostructures independent of experiment results.

  9. Temperature Dependency of Water Vapor Permeability of Shape Memory Polyurethane

    Institute of Scientific and Technical Information of China (English)

    ZENG Yue-min; HU Jin-lian; YAN Hao-jing

    2002-01-01

    Solution-cast films of shape memory polyurethane have beea investigated. Differential scanning calorimetry,DMA, tensile test, water vapor permeability and the shape merry effect were carried out to characterize these polyurethane membranes. Samples cast at higher temperatures contained more hard segment in the crystalline state than a sample cast at lower temperature. The change in the water vapor permeability (WVP) of SMPU films with respect to the temperature follows an S- shaped curve, and increases abruptly at Tm of the soft segment for the fractional free volume (FFV, the ratio of free volume and specific volume in polymers) increased linearly with temperature. The water vapor permeability dependency of the temperature and humidity contribute to the result of the change of diffusion and solubility with the surrounding air condition. The diffusion coefficient (D)are the function of temperature and show good fit the Arrhenius form but show different parameter values when above and below Tg. The crystalline state hardsegment is necessary for the good shape memory effect.

  10. Intercomparison on measurement of water vapour permeability

    DEFF Research Database (Denmark)

    Hansen, Kurt Kielsgaard

    Three different materials are tested - hard woodfibre board - damp proof course - underlay for roofing The water vapour permeability has been measured according to EN ISO 12572 (2001).......Three different materials are tested - hard woodfibre board - damp proof course - underlay for roofing The water vapour permeability has been measured according to EN ISO 12572 (2001)....

  11. Crustal permeability: Introduction to the special issue

    Science.gov (United States)

    Ingebritsen, Steven E.; Gleeson, Tom

    2015-01-01

    The topic of crustal permeability is of broad interest in light of the controlling effect of permeability on diverse geologic processes and also timely in light of the practical challenges associated with emerging technologies such as hydraulic fracturing for oil and gas production (‘fracking’), enhanced geothermal systems, and geologic carbon sequestration. This special issue of Geofluids is also motivated by the historical dichotomy between the hydrogeologic concept of permeability as a static material property that exerts control on fluid flow and the perspective of economic geologists, geophysicists, and crustal petrologists who have long recognized permeability as a dynamic parameter that changes in response to tectonism, fluid production, and geochemical reactions. Issues associated with fracking, enhanced geothermal systems, and geologic carbon sequestration have already begun to promote a constructive dialog between the static and dynamic views of permeability, and here we have made a conscious effort to include both viewpoints. This special issue also focuses on the quantification of permeability, encompassing both direct measurement of permeability in the uppermost crust and inferential permeability estimates, mainly for the deeper crust.

  12. Accurate determination of characteristic relative permeability curves

    Science.gov (United States)

    Krause, Michael H.; Benson, Sally M.

    2015-09-01

    A recently developed technique to accurately characterize sub-core scale heterogeneity is applied to investigate the factors responsible for flowrate-dependent effective relative permeability curves measured on core samples in the laboratory. The dependency of laboratory measured relative permeability on flowrate has long been both supported and challenged by a number of investigators. Studies have shown that this apparent flowrate dependency is a result of both sub-core scale heterogeneity and outlet boundary effects. However this has only been demonstrated numerically for highly simplified models of porous media. In this paper, flowrate dependency of effective relative permeability is demonstrated using two rock cores, a Berea Sandstone and a heterogeneous sandstone from the Otway Basin Pilot Project in Australia. Numerical simulations of steady-state coreflooding experiments are conducted at a number of injection rates using a single set of input characteristic relative permeability curves. Effective relative permeability is then calculated from the simulation data using standard interpretation methods for calculating relative permeability from steady-state tests. Results show that simplified approaches may be used to determine flowrate-independent characteristic relative permeability provided flow rate is sufficiently high, and the core heterogeneity is relatively low. It is also shown that characteristic relative permeability can be determined at any typical flowrate, and even for geologically complex models, when using accurate three-dimensional models.

  13. A Tracer Test to Characterize Treatment of TCE in a Permeable Reactive Barrier

    Science.gov (United States)

    A tracer test was conducted to characterize the flow of ground water surrounding a permeable reactive barrier constructed with plant mulch (a biowall) at the OU-1 site on Altus Air Force Base, Oklahoma. This biowall is intended to intercept and treat ground water contaminated by ...

  14. Fabrication and Prototyping Lab

    Data.gov (United States)

    Federal Laboratory Consortium — Purpose: The Fabrication and Prototyping Lab for composite structures provides a wide variety of fabrication capabilities critical to enabling hands-on research and...

  15. Permeability Tests on Eastern Scheldt Sand

    DEFF Research Database (Denmark)

    Jakobsen, Kim Parsberg

    The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends on the charact......The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends...... on the characteristics of the soil matrix, the permeability is determined for different void ratios. All tests are performed on reconstituted specimens of Eastern Scheldt Sand. The permeability is determined by use of a falling head apparatus. Finally the test results are briefly summarised and a relationship between...... void ratio and permeability is established....

  16. Permeability measurement and control for epoxy composites

    Science.gov (United States)

    Chang, Tsun-Hsu; Tsai, Cheng-Hung; Wong, Wei-Syuan; Chen, Yen-Ren; Chao, Hsien-Wen

    2017-08-01

    The coupling of the electric and magnetic fields leads to a strong interplay in materials' permittivity and permeability. Here, we proposed a specially designed cavity, called the mu cavity. The mu cavity, consisting of a mushroom structure inside a cylindrical resonator, is exclusively sensitive to permeability, but not to permittivity. It decouples materials' electromagnetic properties and allows an accurate measurement of the permeability. With the help of an epsilon cavity, these two cavities jointly determine the complex permeability and permittivity of the materials at microwave frequencies. Homemade epoxy-based composite materials were prepared and tested. Measurement and manipulation of the permeability and permittivity of the epoxy composites will be shown. The results will be compared with the effective medium theories.

  17. Fabrication of recyclable superhydrophobic cotton fabrics

    Science.gov (United States)

    Han, Sang Wook; Park, Eun Ji; Jeong, Myung-Geun; Kim, Il Hee; Seo, Hyun Ook; Kim, Ju Hwan; Kim, Kwang-Dae; Kim, Young Dok

    2017-04-01

    Commercial cotton fabric was coated with SiO2 nanoparticles wrapped with a polydimethylsiloxane (PDMS) layer, and the resulting material surface showed a water contact angle greater than 160°. The superhydrophobic fabric showed resistance to water-soluble contaminants and maintained its original superhydrophobic properties with almost no alteration even after many times of absorption-washing cycles of oil. Moreover, superhydrophobic fabric can be used as a filter to separate oil from water. We demonstrated a simple method of fabrication of superhydrophobic fabric with potential interest for use in a variety of applications.

  18. Compact rock material gas permeability properties

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Huanling, E-mail: whl_hm@163.com [Key Laboratory of Coastal Disaster and Defence, Ministry of Education, Hohai University, Nanjing 210098 (China); LML, University of Lille, Cite Scientifique, 59655 Villeneuve d’Ascq (France); Xu, Weiya; Zuo, Jing [Institutes of Geotechnical Engineering, Hohai University, Nanjing 210098 (China)

    2014-09-15

    Natural compact rocks, such as sandstone, granite, and rock salt, are the main materials and geological environment for storing underground oil, gas, CO{sub 2,} shale gas, and radioactive waste because they have extremely low permeabilities and high mechanical strengths. Using the inert gas argon as the fluid medium, the stress-dependent permeability and porosity of monzonitic granite and granite gneiss from an underground oil storage depot were measured using a permeability and porosity measurement system. Based on the test results, models for describing the relationships among the permeability, porosity, and confining pressure of rock specimens were analyzed and are discussed. A power law is suggested to describe the relationship between the stress-dependent porosity and permeability; for the monzonitic granite and granite gneiss (for monzonitic granite (A-2), the initial porosity is approximately 4.05%, and the permeability is approximately 10{sup −19} m{sup 2}; for the granite gneiss (B-2), the initial porosity is approximately 7.09%, the permeability is approximately 10{sup −17} m{sup 2}; and the porosity-sensitivity exponents that link porosity and permeability are 0.98 and 3.11, respectively). Compared with moderate-porosity and high-porosity rocks, for which φ > 15%, low-porosity rock permeability has a relatively lower sensitivity to stress, but the porosity is more sensitive to stress, and different types of rocks show similar trends. From the test results, it can be inferred that the test rock specimens’ permeability evolution is related to the relative particle movements and microcrack closure.

  19. OBSERVATION AND ANALYSIS OF A PRONOUNCED PERMEABILITY AND POROSITY SCALE-EFFECT IN UNSATURATED FRACTURED TUFF

    Energy Technology Data Exchange (ETDEWEB)

    V. VESSELINOV; ET AL

    2001-01-01

    Over 270 single-hole (Guzman et al., 1996) and 44 cross-hole pneumatic injection tests (Illman et al., 1998; Illman, 1999) have been conducted at the Apache Leap Research Site (ALRS) near Superior, Arizona. They have shown that the pneumatic pressure behavior of fractured tuff at the site is amenable to analysis by methods which treat the rock as a continuum on scales ranging from meters to tens of meters, and that this continuum is representative primarily of interconnected fractures. Both the single-hole and cross-hole test results are free of skin effect. Single-hole tests have yielded estimates of air permeability at various locations throughout the tested rock volume, on a nominal support scale of about 1 m. The corresponding log permeability data exhibit spatial behavior characteristic of a random fractal and yield a kriged estimate of how these 1-m scale log permeabilities vary in three-dimensional space (Chen et al., 2000). Cross-hole tests have been analyzed by means of a three-dimensional inverse model (Vesselinov et al., 2000) in two ways: (a) by interpreting pressure records from individual borehole monitoring intervals, one at a time, while treating the rock as if it was spatially uniform; and (b) by using the inverse model to interpret pressure records from multiple tests and borehole monitoring intervals simultaneously, while treating the rock as a random fractal characterized by a power variogram. The first approach has yielded equivalent air permeabilities and air-filled porosities for a rock volume characterized by a length-scale of several tens of meters. Comparable results have been obtained by means of type-curves (Illman and Neuman, 2001). The second approach amounts to three-dimensional pneumatic tomography, or stochastic imaging, of the rock. It has yielded a high-resolution geostatistical estimate of how air permeability and air-filled porosity, defined over grid blocks having a length-scale of 1 m, vary throughout the modeled rock volume

  20. Observation and analysis of a pronounced permeability and porosity scale-effect in unsaturated fractured tuff

    Energy Technology Data Exchange (ETDEWEB)

    Illman, W. A. (Walter A.); Hyun, Y. (Yunjung); Neuman, S. P.; Di Federico, V. (Vittorio); Tartakovsky, D. M. (Daniel M.); Vesselinov, V. V. (Velimir V.)

    2001-01-01

    Over 270 single-hole (Guzman et d., 1996) and 44 cross-hole pneumatic injection tests (Illman et al., 1998; Illman, 1999) have been conducted at the Apache Leap Research Site (ALRS) near Superior, Arizona. They have shown that the pneumatic pressure behavior of fractured tuff at the site is amenable to analysis by methods which treat the rock as a continuum on scales ranging from meters to tens of meters, and that this continuum is representative primarily of interconnected fractures. Both the single-hole and cross-hole test results are free of skin effect. Single-Role tests have yielded estimates of air permeability at various locations throughout the tested rock volume, on a nonind support scale of about 1 m. The corresponding log permeability data exhibit. spatial behavior characteristic of a random fractal and yield a kriged estimate (Fig. 1) of how these 1-m scale log permeabilities vary in three-dimemional space (Chen et al., 2000). Cross-hole tests have been analyzed by means of a thee-dimensional inverse model (Vesselinov et al., 2000) in two ways: (a) by interpreting pressure 1n:ccirds from individual borehole monitoring intervals, one at a time, while treating the rock as if it was spatially uniform; and (b) by using the inverse model to interpret pressure records from multiple tests and borehole monitoring intervals simultaneously, while treating the rock as a random fractal characterized by a power variogram. The first approach has yielded equivalent air permeabilities and air-filled porosities for a rock volume characterized by a length-scale of several tens of meters. Comparable results have been obtained by means of type-curves (Illman and Neuman, 2001). The second approach mounts to three-tlimensional pneumatic tomography, or stochastic imaging, of the rock. It has yielded a high-resolution geostatistical estimate of how air permeability and air-filled porosity, defined over grid blocks having a length-scale of 1 m, vary throughout the modeled rock

  1. Characterization of facies and permeability patterns in carbonate reservoirs based on outcrop analogs. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kerans, C.; Lucia, F.J.; Senger, R.K.; Fogg, G.E.; Nance, H.S.; Hovorka, S.D.

    1993-07-01

    The primary objective of this research is to develop methods for better describing the three-dimensional geometry of carbonate reservoir flow units as related to conventional or enhanced recovery of oil. San Andres and Grayburg reservoirs were selected for study because of the 13 Bbbl of remaining mobile oil and 17 Bbbl of residual oil in these reservoirs. The key data base is provided by detailed characterization of geologic facies and rock permeability in reservior-scale outcrops of the Permian San Andres Formation in the Guadalupe Mountains of New Mexico. Emphasis is placed on developing an outcrop analog for San Andres strata that can be used as (1) a guide to interpreting the regional and local geologic framework of the subsurface reservoirs (2) a data source illustrating the scales and patterns of variability of rock-fabric facies and petrophysical properties, particularly in lateral dimension, and on scales that cannot be studied during subsurface reservoir characterization. The research approach taken to achieve these objectives utilizes the integration of geologic description, geostatistical techniques, and reservoir flow simulation experiments. Results from this research show that the spatial distribution of facies relative to the waterflood direction can significantly affect how the reservoir produces. Bypassing of unswept oil occurs due to cross flow of injected water from high permeability zones into lower permeability zones were high permeability zones terminate. An area of unswept oil develops because of the slower advance of the water-injection front in the lower permeability zones. When the injection pattern is reversed, the cross-flow effect changes due to the different arrangements of rock-fabric flow units relative to the flow of injected water, and the sweep efficiency is significantly different. Flow across low-permeability mudstones occurs showing that these layers do not necessarily represent flow barriers.

  2. Plant actin controls membrane permeability.

    Science.gov (United States)

    Hohenberger, Petra; Eing, Christian; Straessner, Ralf; Durst, Steffen; Frey, Wolfgang; Nick, Peter

    2011-09-01

    The biological effects of electric pulses with low rise time, high field strength, and durations in the nanosecond range (nsPEFs) have attracted considerable biotechnological and medical interest. However, the cellular mechanisms causing membrane permeabilization by nanosecond pulsed electric fields are still far from being understood. We investigated the role of actin filaments for membrane permeability in plant cells using cell lines where different degrees of actin bundling had been introduced by genetic engineering. We demonstrate that stabilization of actin increases the stability of the plasma membrane against electric permeabilization recorded by penetration of Trypan Blue into the cytoplasm. By use of a cell line expressing the actin bundling WLIM domain under control of an inducible promotor we can activate membrane stabilization by the glucocorticoid analog dexamethasone. By total internal reflection fluorescence microscopy we can visualize a subset of the cytoskeleton that is directly adjacent to the plasma membrane. We conclude that this submembrane cytoskeleton stabilizes the plasma membrane against permeabilization through electric pulses. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Inferring Firn Permeability from Pneumatic Testing: A Case Study on the Greenland Ice Sheet

    Science.gov (United States)

    Sommers, Aleah N.; Rajaram, Harihar; Weber, Eliezer P.; MacFerrin, Michael J.; Colgan, William T.; Stevens, C. Max

    2017-03-01

    Across the accumulation zone of the Greenland ice sheet, summer temperatures can be sufficiently warm to cause widespread melting, as was the case in July 2012 when the entire ice sheet experienced a brief episode of enhanced surface ablation. The resulting meltwater percolates into the firn and refreezes, to create ice lenses and layers within the firn column. This is an important process to consider when estimating the surface mass balance of the ice sheet. The rate of meltwater percolation depends on the permeability of the firn, a property that is not well constrained in the presence of refrozen ice layers and lenses. We present a novel, inexpensive method for measuring in-situ firn permeability using pneumatic testing, a well-established technique used in environmental engineering and hydrology. To illustrate the capabilities of this method, we estimate both horizontal and vertical permeability from pilot tests at six sites on the Greenland ice sheet: KAN-U, DYE-2, EKT, NASA-SE, Saddle, and EastGRIP. These sites cover a range of conditions from mostly dry firn (EastGRIP), to firn with several ice layers and lenses from refrozen meltwater (Saddle, NASA-SE, EKT), to firn with extensive ice layers (DYE-2 and KAN-U). The estimated permeability in firn without refrozen ice layers at EastGRIP agrees well with the range previously reported using an air permeameter to measure permeability through firn core samples at Summit, Greenland. At sites with ice lenses or layers, we find high degrees of anisotropy, with vertical permeability much lower than horizontal permeability. Pneumatic testing is a promising and low-cost technique for measuring firn permeability, particularly as meltwater production increases in the accumulation zone and ice layers and lenses from refrozen melt layers become more prevalent. In these initial proof-of-concept tests, the estimated permeabilities represent effective permeability at the meter scale. With appropriately higher vacuum pressures

  4. Rose-like monodisperse bismuth subcarbonate hierarchical hollow microspheres: one-pot template-free fabrication and excellent visible light photocatalytic activity and photochemical stability for NO removal in indoor air.

    Science.gov (United States)

    Dong, Fan; Lee, S C; Wu, Zhongbiao; Huang, Yu; Fu, Min; Ho, Wing-Kei; Zou, Shichun; Wang, Bo

    2011-11-15

    Rose-like monodisperse hierarchical (BiO)(2)CO(3) hollow microspheres are fabricated by a one-pot template-free method for the first time based on hydrothermal treatment of ammonia bismuth citrate and urea in water. The microstructure and band structure of the as-prepared (BiO)(2)CO(3) superstructure are characterized in detail by X-ray diffraction, Raman spectroscopy, Fourier transform-infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, N(2) adsorption-desorption isotherms, X-ray photoelectron spectroscopy and UV-vis diffuse reflectance spectroscopy. The monodisperse hierarchical (BiO)(2)CO(3) microspheres are constructed by the self-assembly of single-crystalline nanosheets. The aggregation of nanosheets result in the formation of three dimensional hierarchical framework containing mesopores and macropores, which is favorable for efficient transport of reaction molecules and harvesting of photo-energy. The result reveals the existence of special two-band-gap structure (3.25 and 2.0 eV) for (BiO)(2)CO(3). The band gap of 3.25 eV is intrinsic and the formation of smaller band gap of 2.0 eV can be ascribed to the in situ doped nitrogen in lattice. The performance of hierarchical (BiO)(2)CO(3) microspheres as efficient photocatalyst are further demonstrated in the removal of NO in indoor air under both visible light and UV irradiation. It is found that the hierarchical (BiO)(2)CO(3) microspheres not only exhibit excellent photocatalytic activity but also high photochemical stability during long term photocatalytic reaction. The special microstructure, the high charge separation efficiency due to the inductive effect, and two-band-gap structure in all contribute to the outstanding photocatalytic activities. The discovery of monodisperse hierarchical nitrogen doped (BiO)(2)CO(3) hollow structure is significant because of its potential applications in environmental pollution control, solar energy conversion, catalysis and other related

  5. Polymorphous computing fabric

    Science.gov (United States)

    Wolinski, Christophe Czeslaw; Gokhale, Maya B.; McCabe, Kevin Peter

    2011-01-18

    Fabric-based computing systems and methods are disclosed. A fabric-based computing system can include a polymorphous computing fabric that can be customized on a per application basis and a host processor in communication with said polymorphous computing fabric. The polymorphous computing fabric includes a cellular architecture that can be highly parameterized to enable a customized synthesis of fabric instances for a variety of enhanced application performances thereof. A global memory concept can also be included that provides the host processor random access to all variables and instructions associated with the polymorphous computing fabric.

  6. Gut Permeability in Autism Spectrum Disorders

    OpenAIRE

    2014-01-01

    ObjectiveTo test whether gut permeability is increased in autism spectrum disorders (ASD) by evaluating gut permeability in a population-derived cohort of children with ASD compared with age- and intelligence quotient-matched controls without ASD but with special educational needs (SEN).Patients and MethodsOne hundred thirty-three children aged 10–14 years, 103 with ASD and 30 with SEN, were given an oral test dose of mannitol and lactulose and urine collected for 6 hr. Gut permeability was a...

  7. Experimental study of void space, permeability and elastic anisotropy in crustal rocks under ambient and hydrostatic pressure

    Science.gov (United States)

    Benson, Philip Michael

    Anisotropy in the physical and transport properties of crustal rocks is a key influence on crustal evolution and energy resource management. Data from deep seismic soundings, borehole logging and laboratory measurement all show that the physical properties of the earth are anisotropic. Such anisotropy generally results from the superposition of fabric development during diagenesis and/or petrogenesis, and the application of anisotropic tectonic stresses. This leads to an aligned crack and pore fabric in crustal rocks that, in turn, leads to seismic velocity anisotropy and permeability anisotropy. This thesis describes an experimental study which aims to investigate the relationships between pressure, pore fabric geometry and seismic and permeability anisotropy under hydrostatic pressures from room pressure to ~4km depth equivalence within the Earth's crust. Firstly, pore fabric analyses of three representative crustal rock types is presented. These rock types represent a range of crack and pore fabrics. The average void space shape and orientation is determined 3-D using the methods of anisotropy of magnetic susceptibility and velocity anisotropy. Scanning electron microscopy and fluorescent-dye crack imaging techniques further aid in the void space characterisation. Secondly, the development and application of an apparatus capable of contemporaneously measuring elastic wave velocity, porosity and permeability at effective pressures of up to 100 MPa is described. Results are analysed in terms of applied effective pressure and the rock pore fabric type and orientation. Finally, the laboratory data are used to test models that attempt to predict geophysical parameters such as permeability and elastic wave velocity from microstructural attributes. This multi-facetted analysis allows a number of conclusions to be drawn, expanding the state-of-the-art in how the pore fabric microstructure of crustal rock is represented by the methods of elastic wave velocity and

  8. Coating of cellulose-TiO2 nanoparticles on cotton fabric for durable photocatalytic self-cleaning and stiffness.

    Science.gov (United States)

    Kale, Bandu Madhukar; Wiener, Jakub; Militky, Jiri; Rwawiire, Samson; Mishra, Rajesh; Jacob, Karl I; Wang, Youjiang

    2016-10-01

    A new route to make cotton fabric self-cleaning and permanently stiff by coating cellulose-TiO2 on its surface is demonstrated herein. Cellulose-TiO2 dispersion was used for coating and was prepared by mixing TiO2 nanoparticles with cellulose in 60% H2SO4 solution. The surface morphology of cellulose-TiO2 nanoparticles coated sample was analyzed by SEM. The appearance of white TiO2 particles on the surface of the cotton fabric confirmed the successful coating process. The Orange II dye was used as stain and its degradation was observed under UV light. X-ray diffraction analysis showed that cellulose II content increases slightly (by 5.3%) after the solvent treatment. Washing fastness study showed that the fabric stiffness was permanent and self-cleaning properties were stable with 1, 3 and 5% TiO2 coated samples. Air and water vapor permeability was not decreased considerably, whereas tensile strength was increased significantly after coating.

  9. Microwave permeability of stripe patterned FeCoN thin film

    Science.gov (United States)

    Wu, Yuping; Yang, Yong; Ma, Fusheng; Zong, Baoyu; Yang, Zhihong; Ding, Jun

    2017-03-01

    Magnetic stripe patterns are of great importance for microwave applications owing to their highly tunable microwave permeability by adjusting the geometrical dimensions. In this work, stripe patterned FeCoN films with 160 nm thickness are fabricated by using standard UV photolithography. Their microwave permeability are investigated systematically via both experiment and micromagnetic simulation. The good agreement between experimental and simulation results suggests that stripe width is crucial for the microwave magnetic properties of the stripe pattern. It is demonstrated by simulation that with increasing stripe width from 1 to 80 μm the initial permeability shows a continuous growth from about 8-322, whiles the resonance frequency drops dramatically from 18.7 to 3.1 GHz at 4 μm gap size. Smaller gap size would result in slightly increased initial permeability due to larger magnetic volume ratio, accompanied by decreased resonance frequency because of stronger magnetostatic interaction. Moreover, the experimental investigation on stripe length effect indicates that the stripe length should be kept as long as possible to achieve uniform bulk resonance mode and high permeability value. Insufficient stripe length would result in low frequency edge mode and decayed bulk mode. This study could provide valuable guidelines on the selection of proper geometry dimensions of FeCoN stripe patterns for high frequency applications.

  10. Novel porous calcium aluminate/phosphate nanocomposites: in situ synthesis, microstructure and permeability

    Science.gov (United States)

    Yang, Jingzhou; Hu, Xiaozhi; Huang, Juntong; Chen, Kai; Huang, Zhaohui; Liu, Yangai; Fang, Minghao; Sun, Xudong

    2016-02-01

    Permeable porous nanomaterials have extensive applications in engineering fields. Here, we report a novel system of porous calcium aluminate/phosphate (CaAl-CaP) nanocomposites fabricated by pore generator free processing. The CaAl rich samples have close micropores and are not permeable. Interestingly, the CaP rich composites have a unique three-dimensional nanosieve structure with interconnected nanopores and exhibit excellent liquid permeability and adsorbability. The pore size has a narrow distribution of 200-500 nm. The CaAl nanoplatelets in the CaP rich composite have a thickness of 202 nm, a diameter of 1600 nm and an aspect ratio of 8. The porosity is from 19% to 40%. The bending strength and compressive strength are 40.3 MPa and 195 MPa, respectively. The CaP rich nanocomposite is highly permeable so that a water droplet can completely penetrate in 10 seconds (1 mm thick disk). The blue dye can be desorbed in 45 min by ultrasonic vibration. Given the nanosieve porous structure, good permeability/adsorbability and high mechanical properties, the CaP rich nanocomposite has big potential in applications for chemical engineering, biomedical engineering and energy/environmental engineering.

  11. Relative permeability of fractured wellbore cement: an experimental investigation using electrical resistivity monitoring for moisture content

    Science.gov (United States)

    Um, W.; Rod, K. A.; Strickland, C. E.

    2016-12-01

    Permeability is a critical parameter needed to understand flow in subsurface environments; it is particularly important in deep subsurface reservoirs where multiphase fluid flow is common, such as carbon sequestration and geothermal reservoirs. Cement is used in the annulus of wellbores due to its low permeable properties to seal aquifers, reducing leaks to adjacent strata. Extreme subsurface environments of CO2 storage and geothermal production conditions will eventually reduce the cement integrity, propagating fracture networks and increasing the permeability for air and/or water. To date, there have been no reproducible experimental investigations of relative permeability in fractured wellbore cement published. To address this gap, we conducted a series of experiments using fractured Portland cement monoliths with increasing fracture networks. The monolith cylinder sides were jacketed with heavy-duty moisture-seal heat-shrink tubing, then fractured using shear force applied via a hydraulic press. Fractures were generated with different severity for each of three monoliths. Stainless steel endcaps were fixed to the monoliths using the same shrink-wrapped jacket. Fracture characteristics were determined using X-ray microtomography and image analysis. Flow controllers were used to control flow of water and air to supply continuous water or water plus air, both of which were delivered through the influent end cap. Effluent air flow was monitored using a flow meter, and water flow was measured gravimetrically. To monitor the effective saturation of the fractures, a RCON2 concrete bulk electrical resistivity test device was attached across both endcaps and a 0.1M NaNO3 brine was used as the transport fluid to improve resistivity measurements. Water content correlated to resistivity measurements with a r2 > 0.96. Data from the experiments was evaluated using two relative permeability models, the Corey-curve, often used for modeling relative permeability in porous media

  12. Role of void space geometry in permeability evolution in crustal rocks at elevated pressure

    Science.gov (United States)

    Benson, Philip M.; Meredith, Philip G.; Schubnel, Alexandre

    2006-12-01

    A key consequence of the presence of void space within rock is their significant influence upon fluid transport properties. In this study, we measure changes in elastic wave velocities (P and S) contemporaneously with changes in permeability and porosity at elevated pressure for three rock types with widely different void space geometries: a high-porosity sandstone (Bentheim), a tight sandstone (Crab Orchard), and a microcracked granodiorite (Takidani). Laboratory data are then used with the permeability models of Guéguen and Dienes and Kozeny-Carman to investigate the characteristics that different void space geometries impart to measured permeabilities. Using the Kachanov effective medium theory, elastic wave velocities are inverted, permitting the recovery of crack density evolution with increasing effective pressure. The crack densities are then used as input to the microcrack permeability model of Guéguen and Dienes. The classic Kozeny-Carman approach of Walsh and Brace is also applied to the measured permeability data via a least squares fit in order to extract tortuosity data. We successfully predict the evolution of permeability with increasing effective pressure, as directly measured in experiments, and report the contrast between permeability changes observed in rock where microcracks or equant pores dominate the microstructure. Additionally, we show how these properties are affected by anisotropy of the rock types via the measured anisotropic fabrics in each rock. The combined experimental and modeling results illustrate the importance of understanding the details of how rock microstructure changes in response to an external stimulus in predicting the simultaneous evolution of different rock physical properties.

  13. Polymer liquid membrane for nanofiber fabrication

    Directory of Open Access Journals (Sweden)

    Kong Hai-Yan

    2013-01-01

    Full Text Available This paper finds that a polymer liquid membrane can be effectively used for nanomaterials fabrication using a blowing air and an electronic force. Polyvinyl alcohol solution is used to produce membrane on a rotating ring, which passes through periodically the solution, the membrane is deformed into a bubble by the blowing air under the presence of an electrostatic field. The experimental data show that the receptor distance affects the fiber size greatly.

  14. Variability of permeability with diameter of conduit

    Indian Academy of Sciences (India)

    J A Adegoke; J A Olowofela

    2008-05-01

    An entry length is always observed before laminar flow is achieved in fluid flowing in a conduit. This depends on the Reynolds number of the flow and the degree of smoothness of the conduit. This work examined this region and the point where laminar flow commences in the context of flow through conduit packed with porous material like beads, of known porosity. Using some theoretical assumptions, it is demonstrated that permeability varies from zero at wall-fluid boundary to maximum at mid-stream, creating a permeability profile similar to the velocity profile. An equation was obtained to establish this. We also found that peak values of permeability increase with increasing porosity, and therefore entry length increases with increasing porosity with all other parameters kept constant. A plot of peak permeability versus porosity revealed that they are linearly related.

  15. Effect of temperature on sandstone permeability

    DEFF Research Database (Denmark)

    Rosenbrand, Esther; Kjøller, Claus

    assumptions would be required in order to estimate sandstone permeability based on the Kozeny equation. An effective specific surface area per pore volume for permeability was estimated by using image analysis and pore size distributions as from nuclear magnetic resonance (NMR) transverse relaxation data...... be determined based on the Klinkenberg (1941) procedure, which accounts for effects on permeability of gas slip on the fluid-solid interface by means of several permeability measurements with different pore pressures. A comparison between the equivalent pore sizes as estimated using the Kozeny equation...... at 80°C than at 20°C; at 80°C the main effect might be due to an alteration of pore fluid rheology, whereas at 20°C particles might be filtered in pore constrictions. DLVO theory (Derjaguin and Landau (1941); Verwey and Overbeek (1948)) was used to compare effects of temperature and salinity on surface...

  16. Measuring Permeability of Composite Cryotank Laminants

    Science.gov (United States)

    Oliver, Stanley T.; Selvidge, Shawn; Watwood, Michael C.

    2004-01-01

    This paper describes a test method developed to identify whether certain materials and material systems are suitable candidates for large pressurized reusable cryogenic tanks intended for use in current and future manned launch systems. It provides a quick way to screen numerous candidate materials for permeability under anticipated loading environments consistent with flight conditions, as well as addressing reusability issues. cryogenic tank, where the major design issue was hydrogen permeability. It was successfully used to evaluate samples subjected to biaxial loading while maintaining test temperatures near liquid hydrogen. After each sample was thermally preconditioned, a cyclic pressure load was applied to simulate the in-plane strain. First permeability was measured while a sample was under load. Then the sample was unloaded and allowed to return to ambient temperature. The test was repeated to simulate reusability, in order to evaluate its effects on material permeability.

  17. Lunar electrical conductivity and magnetic permeability

    Science.gov (United States)

    Dyal, P.; Parkin, C. W.; Daily, W. D.

    1975-01-01

    Improved analytical techniques are applied to a large Apollo magnetometer data set to yield values of electroconductivity, temperature, magnetic permeability, and iron abundance. Average bulk electroconductivity of the moon is calculated to be .0007 mho/m; a rapid increase with depth to about .003 mho/m within 250 km is indicated. The temperature profile, obtained from the electroconductivity profile for olivine, indicates high lunar temperatures at relatively shallow depths. Magnetic permeability of the moon relative to its environment is calculated to be 1.008 plus or minus .005; a permeability relative to free space of 1.012 plus 0.011, minus 0.008 is obtained. Lunar iron abundances corresponding to this permeability value are 2.5 plus 2.3, minus 1.7 wt% free iron and 5.0-13.5 wt% total iron for a moon composed of a combination of free iron, olivine, and orthopyroxene.

  18. Permeable landscapes for wildlife in the Northeast

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Landscape permeability, also referred to as "habitat connectivity," is the ability of a diverse land area to provide for passage of animals. This project will...

  19. Food Packaging Permeability Behaviour: A Report

    OpenAIRE

    Valentina Siracusa

    2012-01-01

    The use of polymer materials in food packaging field is one of the largest growing market area. Actually the optimization behaviour of packaging permeability is of crucial importance, in order to extend the food shelf-life and to reach the best engineering solution. Studying the permeability characterization of the different polymer material (homogeneous and heterogeneous polymer system) to the different packaging gases, in different environmental condition, is crucial to understand if the se...

  20. Pneumatic fracturing of low permeability media

    Energy Technology Data Exchange (ETDEWEB)

    Schuring, J.R. [New Jersey Institute of Technology, Newark, NJ (United States)

    1996-08-01

    Pneumatic fracturing of soils to enhance the removal and treatment of dense nonaqueous phase liquids is described. The process involves gas injection at a pressure exceeding the natural stresses and at a flow rate exceeding the permeability of the formation. The paper outlines geologic considerations, advantages and disadvantages, general technology considerations, low permeability media considerations, commercial availability, efficiency, and costs. Five case histories of remediation using pneumatic fracturing are briefly summarized. 11 refs., 2 figs., 1 tab.

  1. Properties of cotton fabrics finished by olive oil microcapsules%橄榄油微胶囊整理棉织物的性能

    Institute of Scientific and Technical Information of China (English)

    于丹凤; 裴广玲

    2012-01-01

    In order to prolong the acting time of olive oil with fabrics, olive oil microcapsules were prepared using gelatin and Arabic gum as wall materials and applied to finish the cotton fabric. The effects of pre-drying and curing temperature and time, and volume ratio of finishing agent to adhesive agent on the properties of the finished fabric were investigated. The olive oil percentage and air and moisture permeability of the finished fabric were tested as well. The results showed that the oil content of finished cotton fabric was up to 2% -5% when pre-drying temperature was 70 ℃ , curing temperature was 120℃ for 1 min, solid content of finishing agent was 5 % , and the volume ratio of finishing agent to adhesive agent was 1:1. Moreover, the finished fabric had good slow-release property, good air and moisture permeability, and considerable washing fastness, being able to satisfy the common serviceability requirements.%为延长橄榄油在纺织品及服饰上的作用时间,以明胶和阿拉伯胶为壁材,将其制备成橄榄油微胶囊.并采用自制的橄榄油微胶囊,对棉织物进行整理.考察预烘、焙烘温度和时间、微胶囊材料与黏合剂的比例等对织物性能的影响.并对整理后棉织物含油率、透气透湿性能等进行测试.结果表明,当预烘温度为70℃、焙烘温度为120℃、焙烘时间为1 min、整理剂固含量为5%、整理剂与黏合剂的体积比为1∶1时,整理过的棉织物含油率在2% ~5%,透气透湿性较好,具有较好的缓释性能和一定的耐水洗性,能够满足一般服用要求.

  2. Permeability of lateritic soil by various methods

    Directory of Open Access Journals (Sweden)

    Tatiana Tavares Rodriguez

    2015-10-01

    Full Text Available Soil Permeability is an important property of soil used to dimension several types of engineering works, and it can be quantified by the permeability rates. Despite of the great use, the type of the re doubts about the best way to determine de permeability rates. The main questions are: (1 the type of the method and (2 the reproducibility of samples in tropical soils. So, the objective of this work is to evaluate the permeability of a lateritic soil by comparing values of permeability coefficient determined for laboratory and in situ testing. For this, it was chosen the lateritic soil of Campo Experimental de Engenharia Geotécncia (CEEG of the Universidade Estadual de Londrina (UEL and four equipments: constant and variable head permeameters, Guelph permeameter and infiltrometer. The results show that all the methods present mean value of permeability coefficient on the order of 10-3 cm/s whit variation coefficient in range of 37% to 92% , except the constant permeameter. The heterogeneous structure of lateritic soil (in macro and micro pores is the probably determinant of the variability observed.

  3. Dynamic compressibility of air in porous structures at audible frequencies

    DEFF Research Database (Denmark)

    Lafarge, Denis; Lemarinier, Pavel; Allard, Jean F.;

    1997-01-01

    Measurements of dynamic compressibility of air-filled porous sound-absorbing materials are compared with predictions involving two parametere, the static thermal permeability k'_0 and the thermal characteristic dimension GAMMA'. Emphasis on the notion of dynamic and static thermal permeability...

  4. Comparative field permeability measurement of permeable pavements using ASTM C1701 and NCAT permeameter methods.

    Science.gov (United States)

    Li, Hui; Kayhanian, Masoud; Harvey, John T

    2013-03-30

    Fully permeable pavement is gradually gaining support as an alternative best management practice (BMP) for stormwater runoff management. As the use of these pavements increases, a definitive test method is needed to measure hydraulic performance and to evaluate clogging, both for performance studies and for assessment of permeability for construction quality assurance and maintenance needs assessment. Two of the most commonly used permeability measurement tests for porous asphalt and pervious concrete are the National Center for Asphalt Technology (NCAT) permeameter and ASTM C1701, respectively. This study was undertaken to compare measured values for both methods in the field on a variety of permeable pavements used in current practice. The field measurements were performed using six experimental section designs with different permeable pavement surface types including pervious concrete, porous asphalt and permeable interlocking concrete pavers. Multiple measurements were performed at five locations on each pavement test section. The results showed that: (i) silicone gel is a superior sealing material to prevent water leakage compared with conventional plumbing putty; (ii) both methods (NCAT and ASTM) can effectively be used to measure the permeability of all pavement types and the surface material type will not impact the measurement precision; (iii) the permeability values measured with the ASTM method were 50-90% (75% on average) lower than those measured with the NCAT method; (iv) the larger permeameter cylinder diameter used in the ASTM method improved the reliability and reduced the variability of the measured permeability.

  5. Frictional stability-permeability relationships for fractures in shales: Friction-Permeability Relationships

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Yi [Department of Energy and Mineral Engineering, EMS Energy Institute, and G3 Center, Pennsylvania State University, University Park Pennsylvania USA; Elsworth, Derek [Department of Energy and Mineral Engineering, EMS Energy Institute, and G3 Center, Pennsylvania State University, University Park Pennsylvania USA; Department of Geosciences, EMS Energy Institute, and G3 Center, Pennsylvania State University, University Park Pennsylvania USA; Wang, Chaoyi [Department of Energy and Mineral Engineering, EMS Energy Institute, and G3 Center, Pennsylvania State University, University Park Pennsylvania USA; Ishibashi, Takuya [Department of Energy and Mineral Engineering, EMS Energy Institute, and G3 Center, Pennsylvania State University, University Park Pennsylvania USA; Fukushima Renewable Energy Institute, National Institute of Advanced Industrial Science and Technology, Koriyama Japan; Fitts, Jeffrey P. [Department of Civil and Environmental Engineering, Princeton University, Princeton New Jersey USA

    2017-01-01

    There is wide concern that fluid injection in the subsurface, such as for the stimulation of shale reservoirs or for geological CO2 sequestration (GCS), has the potential to induce seismicity that may change reservoir permeability due to fault slip. However, the impact of induced seismicity on fracture permeability evolution remains unclear due to the spectrum of modes of fault reactivation (e.g., stable versus unstable). As seismicity is controlled by the frictional response of fractures, we explore friction-stability-permeability relationships through the concurrent measurement of frictional and hydraulic properties of artificial fractures in Green River shale (GRS) and Opalinus shale (OPS). We observe that carbonate-rich GRS shows higher frictional strength but weak neutral frictional stability. The GRS fracture permeability declines during shearing while an increased sliding velocity reduces the rate of permeability decline. By comparison, the phyllosilicate-rich OPS has lower friction and strong stability while the fracture permeability is reduced due to the swelling behavior that dominates over the shearing induced permeability reduction. Hence, we conclude that the friction-stability-permeability relationship of a fracture is largely controlled by mineral composition and that shale mineral compositions with strong frictional stability may be particularly subject to permanent permeability reduction during fluid infiltration.

  6. FABRIC QUALITY CONTROL SYSTEMS

    Directory of Open Access Journals (Sweden)

    Özlem KISAOĞLU

    2006-02-01

    Full Text Available Woven fabric quality depends on yarn properties at first, then weaving preparation and weaving processes. Defect control of grey and finished fabric is done manually on the lighted tables or automatically. Fabrics can be controlled by the help of the image analysis method. In image system the image of fabrics can be digitized by video camera and after storing controlled by the various processing. Recently neural networks, fuzzy logic, best wavelet packet model on automatic fabric inspection are developed. In this study the advantages and disadvantages of manual and automatic, on-line fabric inspection systems are given comparatively.

  7. RADIOMETRIC PROPERTIES OFAGRICULTURAL PERMEABLE COVERINGS

    Directory of Open Access Journals (Sweden)

    Sergio Castellano

    2010-06-01

    Full Text Available Nets are commonly used for agricultural applications. However, only little is known about the radiometric properties of net types and how to influence them. In order to investigate the influence of net construction parameters on their radiometric properties, a set of radiometric tests were performed on 45 types of agricultural nets. Laboratory tests on large size net samples was performed using a large and a small integrating sphere. Open field radiometric test were carried out by means of an experimental set up (120x120x50 cm and a full scale shade house. Small differences (less than 5% occurred between laboratory and open field tests. Results highlighted that the porosity and the mesh size, combined with the colour and secondarily, with the fabric and the kind of threads of the net influenced the shading performance of the net. The colour influenced the spectral distribution of the radiation passing through the net absorbing its complementary colours. Since nets are three-dimensional structures the transmissivity of direct light under different angles of incident of solar radiation changes when installed in the warp or weft direction. Transmissivity could be considered one of the main parameters involved in the agronomic performances of the netting system.

  8. Experimental Measurement of Relative Permeability Functions for Fuel Cell GDL Materials

    KAUST Repository

    Hussaini, Irfan

    2009-01-01

    Gas diffusion layer in PEM fuel cells plays a pivotal role in water management. Modeling of liquid water transport through the GDL relies on knowledge of relative permeability functions in the in-plane and through-plane directions. In the present work, air and water relative permeabilities are experimentally determined as functions of saturation for typical GDL materials such as Toray-060, -090, -120 carbon paper and E-Tek carbon cloth materials in their plain, untreated forms. Saturation is measured using an ex-situ gravimetric method. Absolute and relative permeability functions in the two directions of interest are presented. Significant departure from the generally assumed cubic function of saturation is observed. ©The Electrochemical Society.

  9. Development of coffee carbon seamless underwear fabrics and the properties study%咖啡炭无缝内衣面料的开发与性能研究

    Institute of Scientific and Technical Information of China (English)

    王琳; 冯向伟; 曹秋玲

    2015-01-01

    选用咖啡炭涤纶长丝分别与棉纱、天竹纱、棉氨包芯纱和涤纶长丝交织,在全成型针织无缝内衣机上设计生产了5种添纱内衣面料。对织物进行性能测试可知,咖啡炭长丝织物较咖啡炭长丝与短纤纱交织织物的顶破强力和耐磨性好;咖啡炭长丝与棉纱、天竹纱交织,能够改善织物的透气、透湿和导湿性;咖啡炭纤维适宜用来制作直接接触皮肤的无缝内衣面料。%5 kinds of seamless underwear fabrics are developed through seamless underwear knitting machine by using coffee car-bon filament interwoven with cotton yarn,bamboo pulp fiber yarn,cotton and spandex core-spun yarn or polyester filament. The prop-erties of the products are tested and the conclusion is that bursting strength and wear resistance of coffee carbon filament fabric is better than that of coffee carbon fabric interwoven with spun yarn;air permeability,the moisture permeability and moisture conductivity of coffee carbon fabric interwoven with cotton or bamboo pulp fiber yarn are excellent. Coffee carbon filament is suitable for the seamless underwear fabric with direct contact to skin.

  10. Relative permeability in dual porosity porous media

    Energy Technology Data Exchange (ETDEWEB)

    Deghmoum, A. [SONATRACH CRD, Boumerdes (Algeria); Tiab, D. [Oklahoma Univ., Norman, OK (United States); Mazouzi, A. [SONATRACH PED (Algeria)

    2000-06-01

    One of the important factors in the field of reservoir simulation of dual-porosity systems is reliable relative permeability data. Laboratory limitations hinder measurements. The real behaviour of naturally fractures reservoirs is not reflected in the reservoir core samples, which as a rule originate from zones without induced or natural fractures. Therefore, it is commonly assumed that the relative permeability of a naturally fractured system is a straight line, which can cause errors. The authors undertook to conduct special core analyses on Berea outcrop core samples, to simulate fracture opening through the cutting of the samples to get different fracture apertures, to study the effects of dual porosity on the shape of capillary pressure curves, and to evaluate absolute and relative permeability, as they are affected by fracture opening. The correlation obtained between absolute permeability and fracture aperture was good, and capillary pressure curves permitted the observation of the effect of dual porosity. High residual oil saturation was present in the matrix, since the fractures became the easiest route for water flow, and this situation prevented the use of unsteady-state tests to measure relative permeability on the samples. Instead, the centrifuge technique was successfully used. A naturally fractured reservoir (NFR), the Tin Fouye Tabankort (TFT) reservoir in Algeria was selected to extend the findings. The site was principally selected due to the availability of naturally fractured cores and published data. Core observations, well test analysis and borehole imager tools were all TFT natural fracture indicators presented in the paper. Representative data of relative permeability was obtained by conducting a displacement test on a full diameter core to solve the laboratory limitations. The correlation between permeability and fracture opening was used to estimate the aperture of natural fractures in TFT reservoir. 17 refs., 2 tabs., 24 figs.

  11. Comfort Characterization of Various Fabrics for Extremity Protection

    Science.gov (United States)

    2013-09-01

    Soldier Research, Development, and Engineering Center Mike Dalzell Physical Protection Group, Defence Science and Technology Laboratory (UK...Materials Evaluation Team, Natick, MA 01760 † Physical Protection Group, Defence Science and Technology Laboratory, Porton Down, UK Ministry of Defence...offer high air and water vapor permeability with stretchability and low resistance to bending. Correlations between these measurements and garment

  12. In vivo human buccal permeability of nicotine

    DEFF Research Database (Denmark)

    Adrian, Charlotte L; Olin, Helle B D; Dalhoff, Kim

    2006-01-01

    The aim was to examine the in vivo buccal pH-dependent permeability of nicotine in humans and furthermore compare the in vivo permeability of nicotine to previous in vitro permeability data. The buccal permeability of nicotine was examined in a three-way cross-over study in eight healthy non......-smokers using a buccal perfusion cell. The disappearance of nicotine from perfusion solutions with pH 6.0, 7.4, and 8.1 was studied for 3h. The apparent permeability of nicotine (P(app)) was determined at each pH value. Parotid saliva was collected in an attempt to assess systemic levels of nicotine....... The disappearance rate of nicotine increased significantly as the pH increased, which resulted in P(app) values of 0.57+/-0.55 x 10(-4), 2.10+/-0.23 x 10(-4), and 3.96+/-0.54 x 10(-4)cms(-1) (mean+/-S.D.) at pH 6.0, 7.4, and 8.1, respectively. A linear relationship (R(2)=0.993) was obtained between the P...

  13. Permeability Tests on Silkeborg Sand No. 0000

    DEFF Research Database (Denmark)

    Lund, Willy; Jakobsen, Kim Parsberg

    The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends on the charact......The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends...... on the characteristics of the soil matrix, the permeability is determined for different void ratios. All tests are performed on reconstituted specimens of Silkeborg Sand No. 0000. The permeability is determined by use of a falling head apparatus. The apparatus, test procedures and the analysis method are described...... in the succeeding sections. Finally the test results are briefly summarised and a relationship between void ratio l and permeability is established....

  14. Vascular permeability in cerebral cavernous malformations

    DEFF Research Database (Denmark)

    Mikati, Abdul G; Khanna, Omaditya; Zhang, Lingjiao;

    2015-01-01

    Patients with the familial form of cerebral cavernous malformations (CCMs) are haploinsufficient for the CCM1, CCM2, or CCM3 gene. Loss of corresponding CCM proteins increases RhoA kinase-mediated endothelial permeability in vitro, and in mouse brains in vivo. A prospective case-controlled observ......Patients with the familial form of cerebral cavernous malformations (CCMs) are haploinsufficient for the CCM1, CCM2, or CCM3 gene. Loss of corresponding CCM proteins increases RhoA kinase-mediated endothelial permeability in vitro, and in mouse brains in vivo. A prospective case......-controlled observational study investigated whether the brains of human subjects with familial CCM show vascular hyperpermeability by dynamic contrast-enhanced quantitative perfusion magnetic resonance imaging, in comparison with CCM cases without familial disease, and whether lesional or brain vascular permeability...... correlates with CCM disease activity. Permeability in white matter far (WMF) from lesions was significantly greater in familial than in sporadic cases, but was similar in CCM lesions. Permeability in WMF increased with age in sporadic patients, but not in familial cases. Patients with more aggressive...

  15. Material Transport with Air Jet

    Directory of Open Access Journals (Sweden)

    István Patkó

    2005-11-01

    Full Text Available In the field of industry, there are only a very few examples of material transportwith air jet, and one of these is the air jet loom. In this weaving technology, the weft (thetransversal yarn of the fabric is shot by air jet. This paper will set up the mathematicalmodel of yarn end movement. For a special case, I will specify a solution of the model.

  16. Comparison between traditional laboratory tests, permeability measurements and CT-based fluid flow modelling for cultural heritage applications

    Energy Technology Data Exchange (ETDEWEB)

    De Boever, Wesley, E-mail: Wesley.deboever@ugent.be [UGCT/PProGRess, Dept. of Geology, Ghent University, Krijgslaan 281, 9000 Ghent (Belgium); Bultreys, Tom; Derluyn, Hannelore [UGCT/PProGRess, Dept. of Geology, Ghent University, Krijgslaan 281, 9000 Ghent (Belgium); Van Hoorebeke, Luc [UGCT/Radiation Physics, Dept. of Physics & Astronomy, Ghent University, Proeftuinstraat 86, 9000 Ghent (Belgium); Cnudde, Veerle [UGCT/PProGRess, Dept. of Geology, Ghent University, Krijgslaan 281, 9000 Ghent (Belgium)

    2016-06-01

    In this paper, we examine the possibility to use on-site permeability measurements for cultural heritage applications as an alternative for traditional laboratory tests such as determination of the capillary absorption coefficient. These on-site measurements, performed with a portable air permeameter, were correlated with the pore network properties of eight sandstones and one granular limestone that are discussed in this paper. The network properties of the 9 materials tested in this study were obtained from micro-computed tomography (μCT) and compared to measurements and calculations of permeability and the capillary absorption rate of the stones under investigation, in order to find the correlation between pore network characteristics and fluid management characteristics of these sandstones. Results show a good correlation between capillary absorption, permeability and network properties, opening the possibility of using on-site permeability measurements as a standard method in cultural heritage applications. - Highlights: • Measurements of capillary absorption are compared to in-situ permeability. • We obtain pore size distribution and connectivity by using micro-CT. • These properties explain correlation between permeability and capillarity. • Correlation between both methods is good to excellent. • Permeability measurements could be a good alternative to capillarity measurement.

  17. Influence of yarn folding on UV protection properties of hemp knitted fabrics

    Directory of Open Access Journals (Sweden)

    Kocić Ana A.

    2016-01-01

    fabrics construction and physical properties were also determined. Bearing in mind that plain knitted fabrics are particularly susceptible to relaxation, they were subjected to relaxation and shrinkage by wetting process, and testing procedure was repeated on the water-treated samples. The results obtained indicated that the folding operation influences UV protection properties of knitted fabrics through an influence on a loop configuration, i.e. the fabric openness. Relaxation and shrinkage of the knitted fabrics due to wet relaxation caused the reduction of macro-porosity increasing the UPF of the knitted fabrics. Although the knitted fabric produced from single hemp yarn was characterized by higher UPF, the UVR transmittance of the folded hemp yarn knitted fabric after wet relaxation placed it in the “excellent UV protection category” (according to European Standard EN 13758-2. This fact together with the better thermal comfort manifested itself in higher air permeability, confirmed the potential of folding operation in terms of UV protection properties of textile materials.

  18. Comparison between traditional laboratory tests, permeability measurements and CT-based fluid flow modelling for cultural heritage applications.

    Science.gov (United States)

    De Boever, Wesley; Bultreys, Tom; Derluyn, Hannelore; Van Hoorebeke, Luc; Cnudde, Veerle

    2016-06-01

    In this paper, we examine the possibility to use on-site permeability measurements for cultural heritage applications as an alternative for traditional laboratory tests such as determination of the capillary absorption coefficient. These on-site measurements, performed with a portable air permeameter, were correlated with the pore network properties of eight sandstones and one granular limestone that are discussed in this paper. The network properties of the 9 materials tested in this study were obtained from micro-computed tomography (μCT) and compared to measurements and calculations of permeability and the capillary absorption rate of the stones under investigation, in order to find the correlation between pore network characteristics and fluid management characteristics of these sandstones. Results show a good correlation between capillary absorption, permeability and network properties, opening the possibility of using on-site permeability measurements as a standard method in cultural heritage applications.

  19. Tunable permeability of magnetic wires at microwaves

    Science.gov (United States)

    Panina, L. V.; Makhnovskiy, D. P.; Morchenko, A. T.; Kostishin, V. G.

    2015-06-01

    This paper presents the analysis into microwave magnetic properties of magnetic microwires and their composites in the context of applications in wireless sensors and tunable microwave materials. It is demonstrated that the intrinsic permeability of wires has a wide frequency dispersion with relatively large values in the GHz band. In the case of a specific magnetic anisotropy this results in a tunable microwave impedance which could be used for distributed wireless sensing networks in functional composites. The other range of applications is related with developing the artificial magnetic dielectrics with large and tunable permeability. The composites with magnetic wires with a circumferential anisotropy have the effective permeability which differs substantially from unity for a relatively low concentration (less than 10%). This can make it possible to design the wire media with a negative and tunable index of refraction utilising natural magnetic properties of wires.

  20. Gyroid Nanoporous Membranes with Tunable Permeability

    DEFF Research Database (Denmark)

    Li, Li; Schulte, Lars; Clausen, Lydia D.

    2011-01-01

    Understanding the relevant permeability properties of ultrafiltration membranes is facilitated by using materials and procedures that allow a high degree of control on morphology and chemical composition. Here we present the first study on diffusion permeability through gyroid nanoporous cross......-sided skin membranes, much faster than expected by a naive resistance-in-series model; the flux through the two-sided skin membranes even increases with the membrane thickness. We propose a model that captures the physics behind the observed phenomena, as confirmed by flow visualization experiments...... the effective diffusion coefficients of a series of antibiotics, proteins, and other biomolecules; solute permeation is discussed in terms of hindered diffusion. The combination of uniform bulk morphology, isotropically percolating porosity, controlled surface chemistry, and tunable permeability is distinctive...

  1. Ammonia and urea permeability of mammalian aquaporins

    DEFF Research Database (Denmark)

    Litman, Thomas; Søgaard, Rikke; Zeuthen, Thomas

    2009-01-01

    The human aquaporins,AQP3,AQP7, AQP8,AQP9, and possibly AQP10, are permeable to ammonia, and AQP7, AQP9, and possibly AQP3, are permeable to urea. In humans, these aquaporins supplement the ammonia transport of the Rhesus (Rh) proteins and the urea transporters (UTs). The mechanism by which...... ammonium is transported by aquaporins is not fully resolved. A comparison of transport equations, models, and experimental data shows that ammonia is transported in its neutral form, NH(3). In the presence of NH(3), the aquaporin stimulates H(+) transport. Consequently, this transport of H(+) is only...... significant at alkaline pH. It is debated whether the H(+) ion passes via the aquaporin or by some external route; the investigation of this problem requires the aquaporin-expressing cell to be voltage-clamped. The ammonia-permeable aquaporins differ from other aquaporins by having a less restrictive aromatic...

  2. Food Packaging Permeability Behaviour: A Report

    Directory of Open Access Journals (Sweden)

    Valentina Siracusa

    2012-01-01

    Full Text Available The use of polymer materials in food packaging field is one of the largest growing market area. Actually the optimization behaviour of packaging permeability is of crucial importance, in order to extend the food shelf-life and to reach the best engineering solution. Studying the permeability characterization of the different polymer material (homogeneous and heterogeneous polymer system to the different packaging gases, in different environmental condition, is crucial to understand if the selected material is adapted to the chosen food contact field. Temperature and humidity parameters are of crucial importance for food quality preservation, especially in real life situations, like food market, and house long-life use. The aim of this report was to collect information about the state of the art on the permeability characteristics of the polymer packages used on food field.

  3. Magnetohydrodynamic Flow Past a Permeable Bed

    Directory of Open Access Journals (Sweden)

    R. Venugopal

    1983-01-01

    Full Text Available The paper evaluates mass flow velocity heat transfer rates and velocity/temperature distributions in the viscous, incompressible and slightly conducting fluid past a permeable bed in three different configurations namely (1 Couette flow (2 Poiseuille flow and (3 free surface flow, under the influence of a uniform transverse magnetic field. To discuss the solution, the flow region is divided into two zones : Zone 1 (from the impermeable upper rigid plate to the permeable bed in which the flow is laminar and governed by Navier-Stokes equations, and Zone 2 (the permeable bed below the nominal surface in which the flow is governed by Darcy law. The paper also investigates the effects of magnetic field, porosity and Biot number on the physical quantities mentioned above.

  4. Quantifying porosity, compressibility and permeability in Shale

    DEFF Research Database (Denmark)

    Mbia, Ernest Ncha; Fabricius, Ida Lykke; Frykman, Peter

    (XRD) of shale samples show about 50% silt and high content of kaolinite in the clay fraction when compared with offshore samples from the Central Graben. Porosity measurements from helium porosimetry-mercury immersion (HPMI), mercury injection capillary pressure (MICP) and nuclear magnetic resonance...... (NMR) show that, the MICP porosity is 9-10% points lower than HPMI and NMR porosity. Compressibility result shows that deep shale is stiffer in situ than normally assumed in geotechnical modelling and that static compressibility corresponds with dynamic one only at the begining of unloading stress...... strain data. We found that Kozeny's modelled permeability fall in the same order of magnitude with measured permeability for shale rich in kaolinite but overestimates permeability by two to three orders of magnitudes for shale with high content of smectite. The empirical Yang and Aplin model gives good...

  5. Magnetic levitation from negative permeability materials

    Energy Technology Data Exchange (ETDEWEB)

    Coffey, Mark W., E-mail: mcoffey@mines.edu [Department of Physics, Colorado School of Mines, Golden, CO 80401 (United States)

    2012-09-03

    As left-handed materials and metamaterials are becoming more prevalent, we examine the effect of negative permeability upon levitation force. We first consider two half spaces of differing permeability and a point magnetic source, so that the method of images may be employed. We determine that the resulting force may be larger than for conventional magnetic materials. We then illustrate the inclusion of a finite sample thickness. -- Highlights: ► The effect of negative permeability upon levitation force is considered. ► Such an effect could be realized with metamaterials. ► The resulting force may be larger than with conventional materials. ► The analysis is extended to allow for a finite sample thickness. ► Representative numerical values are given.

  6. Blood flow and permeability in microvessels

    Science.gov (United States)

    Sugihara-Seki, Masako; Fu, Bingmei M.

    2005-07-01

    The mechanics of blood flow in microvessels and microvessel permeability are reviewed. In the first part, characteristics of blood flow in vivo and in vitro are described from a fluid-mechanical point of view, and mathematical models for blood flow in microvessels are presented. Possible causes of the increased flow resistance obtained in vivo compared to in vitro are examined, including the effects of irregularities of vessel lumen, the presence of endothelial surface glycocalyx and white blood cells. In the second part, the ultrastructural pathways and mechanisms whereby endothelial cells and the clefts between the cells modulate microvessel permeability to water and solutes are introduced. Previous and current models for microvessel permeability to water and solutes are reviewed. These models examine the role of structural components of interendothelial cleft, such as junction strands and surface glycocalyx, in the determination of water and solute transport across the microvessel walls. Transport models in the tissue space surrounding the microvessel are also described.

  7. Preparation and properties of silver electroless plated PET fabrics%化学镀银涤纶织物的制备及其性能

    Institute of Scientific and Technical Information of China (English)

    徐文龙; 熊杰; 徐勤; 刘志才; 焦玉雪; 陈虎

    2011-01-01

    利用化学镀方法制备镀银电磁屏蔽涤纶织物.分别采用场发射电镜( FE-SEM)、电子能谱(EDS)和X射线衍射(XRD)表征镀层的表面形貌、成分和结晶情况;考察了织物的厚度、增重率、耐摩擦色牢度、表面电阻、抗静电性、拉伸断裂强力、断裂伸长率、刚柔性、悬垂性以及透气性.结果表明:镀层为高纯度立方面心结构的单质银;化学镀银后织物的抗静电性能、拉伸断裂强力、断裂伸长率、抗弯刚度及悬垂性增加,而透气性下降;耐摩擦色牢度随着增重率的增加而减小,增重率为35%时,织物的耐摩擦色牢度和导电性均比较优越.%Electromagnetic shielding poly ( ethylene terephthalate) ( PET) fabrics were prepared by electroless plating of silver. The silver plated fabrics were characterized by surface morphology, chemical composition and crystal structure using FE-SEM, EDS and XRD. An investigation of thickness, mass gain, color fastness to rubbing, surface resistance, anti-static property, tensile strength, breaking elongation, stiffness, draping and air permeability of PET fabrics before and after electroless plating of silver. The Results revealed that the metal-layer is high purity sliver with face cubic central structure. Sliver plated polyester fabric has higher anti-static property, tensile strength, elongation, stiffness, and draping, but lower air permeability. The color fastness to rubbing decreases with the increase of mass gain. The fabrics show good color fastness to rubbing and conductivity when the mass gain 35% .

  8. Small-bowel permeability in collagenous colitis

    DEFF Research Database (Denmark)

    Wildt, Signe; Madsen, Jan L; Rumessen, Jüri J

    2006-01-01

    Collagenous colitis (CC) is a chronic inflammatory bowel disease that affects the colon. However, some patients with CC present with accompanying pathologic small-bowel manifestations such as coeliac disease, defects in bile acid absorption and histopathologic changes in small-intestinal biopsies......, indicating that CC is a pan-intestinal disease. In small-intestinal disease, the intestinal barrier function may be impaired, and the permeability of the small intestine altered. The purpose of this research was to study small-bowel function in patients with CC as expressed by intestinal permeability....

  9. Liquid Permeability of Ceramic Foam Filters

    OpenAIRE

    Zhang, Kexu

    2012-01-01

    This project is in support of the PhD project: ‘Removal of Inclusions from Liquid Aluminium using Electromagnetically Modified Filtration’. The purpose of this project was to measure the tortuosity, and permeability of ~50mm thick: 30, 40, 50 and 80 pores per inch (ppi) commercial alumina ceramic foam filters (CFFs). Measurements have been taken of: cell (pore), window and strut sizes, porosity, tortuosity and liquid permeability. Water velocity from ~0.015-0.77 m/s have been used ...

  10. Development of an Improved Permeability Modification Simulator

    Energy Technology Data Exchange (ETDEWEB)

    Gao, H.W.; Elphnick, J.

    1999-03-09

    This report describes the development of an improved permeability modification simulator performed jointly by BDM Petroleum Technologies and Schlumberger Dowell under a cooperative research and development agreement (CRADA) with the US Department of Energy. The improved simulator was developed by modifying NIPER's PC-GEL permeability modification simulator to include a radial model, a thermal energy equation, a wellbore simulator, and a fully implicit time-stepping option. The temperature-dependent gelation kinetics of a delayed gel system (DGS) is also included in the simulator.

  11. The Permeability of Rubble Mound Breakwaters

    DEFF Research Database (Denmark)

    Williams, A.F.; Burcharth, H. F.; Adel, H. den

    1992-01-01

    The results of an extensive series of permeability experiments originally analysed by Shih (1990) are reinterpreted in the light of new experiments. It is proposed that the Forchheimer equation might not fully describe flow at the high Reynolds numbers found in the interior of rubble material....... A new series of tests designed to test for deviations from the Forchheimer equation and investigate the effects of material shape are described. While no evidence can be found to indicate a deviation from the Forchheimer equation a dependency of permeability and the surface roughness the material...

  12. Partial oxidation of methane to syngas in a mixed-conducting oxygen permeable membrane reactor

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Mixed-conducting oxygen permeable membranes represent a class of novel ceramic membranes, which exhibit mixed oxygen ionic and electronic conductivities. At high temperatures, oxygen can permeate through the membrane from the high to low oxygen pressure side under an oxygen concentration gradient. Theoretically, the permselectivity of oxygen is 100%. Recently, a novel mixed-conducting membrane--Ba0.5Sr0.5Co0.8Fe0.2O3-δ has been developed, which shows extremely high oxygen permeability and promising stability. Furthermore, the reactor made with such membranes was successfully applied to the partial oxidation of methane to syngas reaction using air as the oxygen source, which realized the coupling of the separation of oxygen from air and the partial oxidation of membrane reaction in one process. At 850℃, methane conversion >88%, CO selectivity >97% and oxygen permeation rate of about 7.8 mL/(cm2.min) were obtained.

  13. Examining the role of Microcracks in Modelling the Permeability Evolution of Crustal Rocks at Elevated Hydrostatic Pressure.

    Science.gov (United States)

    Benson, P. M.; Schubnel, A.; Meredith, P. G.; Young, P.

    2005-12-01

    A key consequence of the presence of void space within rock is its significant influence upon fluid transport properties. This observation is fundamental to our understanding of crustal evolution and energy resource management, for example the efficient recovery of hydrocarbon and water resources, and the safe disposal of hazardous waste. However, the processes responsible for porosity formation are diverse, ranging from depositional processes such as sedimentary sorting and grain alignment, through diagenetic processes such as compaction and cementation, to deformational processes such as microcracking. The porosity that evolves from the superposition of these processes over time may therefore have a complex geometry or fabric. In addition, many of these processes have an inherent directionality which may lead to anisotropy of the void space, and all have been shown to play important roles in influencing the fluid transport properties of rock. The measurement of permeability at elevated pressures and the calculation of permeability from other data (such as elastic wave velocity) remains non-trivial. In particular, in order to test models that predict such relations, ideally both elastic wave velocity and permeability should be measured simultaneously. In this study, we use a novel apparatus in order to measure elastic wave velocities (P and S) contemporaneously with permeability and porosity for three rock types, a high porosity sandstone (Bentheim), a tight sandstone (Crab Orchard), and a microcracked granite (Takidani). This laboratory data is then used with permeability models of Gueguen and Dienes and Kozeny-Carman to investigate the role that void space of differing apertures imparts on the measured permeability of different rock types. Using the Kachanov non-interactive effective medium theory, measured elastic wave velocities are inverted using a least square fit, permitting the recovery of crack density evolution with increasing hydrostatic pressure. This

  14. The use of reflective and permeable pavements as a potential practice for heat island mitigation and stormwater management

    Science.gov (United States)

    Li, H.; Harvey, J. T.; Holland, T. J.; Kayhanian, M.

    2013-03-01

    To help address the built environmental issues of both heat island and stormwater runoff, strategies that make pavements cooler and permeable have been investigated through measurements and modeling of a set of pavement test sections. The investigation included the hydraulic and thermal performance of the pavements. The permeability results showed that permeable interlocking concrete pavers have the highest permeability (or infiltration rate, ˜0.5 cm s-1). The two permeable asphalt pavements showed the lowest permeability, but still had an infiltration rate of ˜0.1 cm s-1, which is adequate to drain rainwater without generating surface runoff during most typical rain events in central California. An increase in albedo can significantly reduce the daytime high surface temperature in summer. Permeable pavements under wet conditions could give lower surface temperatures than impermeable pavements. The cooling effect highly depends on the availability of moisture near the surface layer and the evaporation rate. The peak cooling effect of watering for the test sections was approximately 15-35 °C on the pavement surface temperature in the early afternoon during summer in central California. The evaporative cooling effect on the pavement surface temperature at 4:00 pm on the third day (25 h after watering) was still 2-7 °C lower compared to that on the second day, without considering the higher air temperature on the third day. A separate and related simulation study performed by UCPRC showed that full depth permeable pavements, if designed properly, can carry both light-duty traffic and certain heavy-duty vehicles while retaining the runoff volume captured from an average California storm event. These preliminarily results indicated the technical feasibility of combined reflective and permeable pavements for addressing the built environment issues related to both heat island mitigation and stormwater runoff management.

  15. 2D InP photonic crystal fabrication process development

    NARCIS (Netherlands)

    Rong, B.; Van der Drift, E.; Van der Heijden, R.W.; Salemink, H.W.M.

    2006-01-01

    We have developed a reliable process to fabricate high quality 2D air-hole and dielectric column InP photonic crystals with a high aspect ratio on a STS production tool using ICP N2+Cl2 plasma. The photonic crystals have a triangular lattice with lattice constant of 400 nm and air-hole and dielectri

  16. Membrane-based air conditioning. Decentral desiccant cooling; Membranbasierte Raumklimatisierung. Dezentrale sorptionsgestuetzte Klimatisierung

    Energy Technology Data Exchange (ETDEWEB)

    Rosenbaum, Hannes [Institut fuer Luft- und Kaeltetechnik gGmbH, Dresden (Germany)

    2012-04-15

    Semipermeable membranes have a considerable potential use in air conditioning systems due to their properties. As water resistant but water vapor permeable functional separation layers, they allow desiccant air-conditioning processes in decentral air conditioning systems and a condensate-free air dehumidification at cooling ceiling elements. (orig.)

  17. Nitric oxide turnover in permeable river sediment

    DEFF Research Database (Denmark)

    Schreiber, Frank; Stief, Peter; Kuypers, Marcel M M

    2014-01-01

    We measured nitric oxide (NO) microprofiles in relation to oxygen (O2) and all major dissolved N-species (ammonium, nitrate, nitrite, and nitrous oxide [N2O]) in a permeable, freshwater sediment (River Weser, Germany). NO reaches peak concentrations of 0.13 μmol L-1 in the oxic zone and is consumed...

  18. Water permeability in human airway epithelium

    DEFF Research Database (Denmark)

    Pedersen, Peter Steen; Procida, Kristina; Larsen, Per Leganger;

    2005-01-01

    Osmotic water permeability (P(f)) was studied in spheroid-shaped human airway epithelia explants derived from nasal polyps by the use of a new improved tissue collection and isolation procedure. The fluid-filled spheroids were lined with a single cell layer with the ciliated apical cell membrane...

  19. Quantitative permeability imaging of plant tissues

    NARCIS (Netherlands)

    Sibgatullin, T.; Vergeldt, F.J.; Gerkema, E.; As, van H.

    2010-01-01

    A method for mapping tissue permeability based on time-dependent diffusion measurements is presented. A pulsed field gradient sequence to measure the diffusion encoding time dependence of the diffusion coefficients based on the detection of stimulated spin echoes to enable long diffusion times is co

  20. Vascular permeability and drug delivery in cancers

    Directory of Open Access Journals (Sweden)

    Sandy eAzzi

    2013-08-01

    Full Text Available The endothelial barrier strictly maintains vascular and tissue homeostasis, and therefore modulates many physiological processes such as angiogenesis, immune responses, and dynamic exchanges throughout organs. Consequently, alteration of this finely tuned function may have devastating consequences for the organism. This is particularly obvious in cancers, where a disorganized and leaky blood vessel network irrigates solid tumors. In this context, vascular permeability drives tumor-induced angiogenesis, blood flow disturbances, inflammatory cell infiltration, and tumor cell extravasation. This can directly restrain the efficacy of conventional therapies by limiting intravenous drug delivery. Indeed, for more effective anti-angiogenic therapies, it is now accepted that not only should excessive angiogenesis be alleviated, but also that the tumor vasculature needs to be normalized. Recovery of normal state vasculature requires diminishing hyperpermeability, increasing pericyte coverage, and restoring the basement membrane, to subsequently reduce hypoxia and interstitial fluid pressure. In this review, we will introduce how vascular permeability accompanies tumor progression and, as a collateral damage, impacts on efficient drug delivery. The molecular mechanisms involved in tumor-driven vascular permeability will next be detailed, with a particular focus on the main factors produced by tumor cells, especially the emblematic vascular endothelial growth factor (VEGF. Finally, new perspectives in cancer therapy will be presented, centered on the use of anti-permeability factors and normalization agents.

  1. [Graphic recording of the maxillary ostium permeability].

    Science.gov (United States)

    Rosique, M; Pastor, A; Hellín, D; García-Ortega, F P

    1993-01-01

    Currently we practise salpingography for evaluating Eustachian tube permeability. In a similar mode, we describe a technique of graphic search, with impedianciometry, of patency in the osteomeatal complex, after puncture and placing Foley's catheter in the maxillary sinus. In several cases without opening, we make topical treatment though catheter. For this technique, we propose the term of infundibulography.

  2. Water permeability of pigmented waterborne coatings

    NARCIS (Netherlands)

    Donkers, P.A.J.; Huinink, H.P.; Erich, S.J.F.; Reuvers, N.J.W.; Adan, O.C.G.

    2013-01-01

    Coatings are used in a variety of applications. Last decades more and more coating systems are transforming from solvent to waterborne coating systems. In this study the influence of pigments on the water permeability of a waterborne coating system is studied, with special interest in the possible i

  3. Pump and treat in low permeability media

    Energy Technology Data Exchange (ETDEWEB)

    Mackay, D.M. [Univ. of Waterloo, Ontario (Canada)

    1996-08-01

    Pump and Treat (P&T) is a commonly applied technology whose primary promise for the low permeability environments of interest to these technology reviews is almost certainly containment of the problem. Conventional P&T would be expected to offer little promise of complete restoration in such environments, unless very long time frames (decades or centuries) are considered. A variety of approaches have been proposed to enhance the efficiency of P&T; some appear to offer little promise in low or mixed permeability environments, while others may offer more promise (e.g. hydro- or pneumatic-fracturing, which are described elsewhere in this document, and application of vacuum to the extraction well(s), which is a proprietary technology whose promise is currently difficult to assess objectively). Understanding the potential advantages and means of optimizing these enhancement approaches requires more understanding of the basic processes limiting P&T performance in low or mixed permeability media. These efforts are probably also necessary to understand the advantages and means of optimizing many of the very different remedial technologies that may be applicable to low or mixed permeability environments. Finally, since a reasonably certain capability of P&T is containment (i.e. prevention of further migration of contaminants), P&T may generally be required as a sort of safety net around sites at which the alternative technologies are being tested or applied. 23 refs.

  4. Foam film permeability: theory and experiment.

    Science.gov (United States)

    Farajzadeh, R; Krastev, R; Zitha, Pacelli L J

    2008-02-28

    The mass transfer of gas through foam films is a prototype of various industrial and biological processes. The aim of this paper is to give a perspective and critical overview of studies carried out to date on the mass transfer of gas through foam films. Contemporary experimental data are summarized, and a comprehensive overview of the theoretical models used to explain the observed effects is given. A detailed description of the processes that occur when a gas molecule passes through each layer that forms a foam film is shown. The permeability of the film-building surfactant monolayers plays an important role for the whole permeability process. It can be successfully described by the models used to explain the permeability of surfactant monolayers on aqueous sub-phase. For this reason, the present paper briefly discusses the surfactant-induced resistance to mass transfer of gases through gas-liquid interface. One part of the paper discusses the experimental and theoretical aspects of the foam film permeability in a train of foam films in a matrix or a cylinder. This special case is important to explain the gas transfer in porous media or in foams. Finally, this paper will highlight the gaps and challenges and sketch possible directions for future research.

  5. Tunable permeability of magnetic wires at microwaves

    Energy Technology Data Exchange (ETDEWEB)

    Panina, L.V., E-mail: lpanina@plymouth.ac.uk [National University of Science and Technology, MISiS, Moscow (Russian Federation); Institute for Design Problems in Microelectronics, RAN, Moscow (Russian Federation); Makhnovskiy, D.P. [School of Computing and Mathematics, University of Plymouth (United Kingdom); Morchenko, A.T.; Kostishin, V.G. [National University of Science and Technology, MISiS, Moscow (Russian Federation)

    2015-06-01

    This paper presents the analysis into microwave magnetic properties of magnetic microwires and their composites in the context of applications in wireless sensors and tunable microwave materials. It is demonstrated that the intrinsic permeability of wires has a wide frequency dispersion with relatively large values in the GHz band. In the case of a specific magnetic anisotropy this results in a tunable microwave impedance which could be used for distributed wireless sensing networks in functional composites. The other range of applications is related with developing the artificial magnetic dielectrics with large and tunable permeability. The composites with magnetic wires with a circumferential anisotropy have the effective permeability which differs substantially from unity for a relatively low concentration (less than 10%). This can make it possible to design the wire media with a negative and tunable index of refraction utilising natural magnetic properties of wires. - Highlights: • Applications of magnetic microwires for functional composites and distributed sensor networks are proposed. • Diluted composites with magnetic microwires can demonstrate tunable left-handed properties. • Large microwave permeability combined with a specific magnetic structure lead to a large and sensitive microwave magnetoimpedance. • Microwave magnetoimpedance highly sensitive to temperature is demonstrated.

  6. Research on the antibacterial and wash-resistant performance of different fabric with Ag carrying antibacterial agent%载银抗菌剂在不同织物上的抑菌及水洗性能研究

    Institute of Scientific and Technical Information of China (English)

    王英沣; 毕松梅; 阎琳

    2014-01-01

    对不同的棉织物进行抗菌后整理,并对各组织物的抗菌性能、耐水洗性能以及透气性能等进行研究,探讨棉织物的纱线线密度、经纬密度等因素对织物各项性能的影响。研究结果表明:织物经纬密度越大,纱线越粗,越有利于抗菌剂的附着,其最终的抗菌性能较好,但相应造成织物透气性有一定下降;在耐水洗性方面,织物经纬密度越大,纱线越粗,最终的耐水洗性能以及抗菌性能保留率较好,经40次水洗,抗菌性能保留率仍能达到40%以上。%Based on the antibacterial finishing , the antibacterial , wash-resistant performance and air permeability of different cotton fabrics were studied .The effects of yarn tex and thread density on the performance of the cotton fabrics were also studied .The result showed ,the greater in yarn tex and thread density , the better the antibacterial properties ,but the air permeability of farbic would decline correspondingly .In terms of water-resistant, the greater in yarn tex and thread density , the better antibacterial properties of re-tention rate and the better water-resistant of the fabric after washing .After 40 times of washing , the reten-tion rate of antibacterial properties could reach more than 40%.

  7. 湿法涂层制备涤纶洁净服面料%Polyester cleanroom fabrics prepared by wet coating process

    Institute of Scientific and Technical Information of China (English)

    高静; 沈安京; 李芮

    2009-01-01

    采用聚偏氟乙烯(PVDF)涂层液对涤纶织物进行湿法涂层以制备洁净服面料,讨论各工艺因素对涂层面料性能的影响.试验获得的优化工艺条件为:PVDF用量14%,添加剂LiCl 3%,预挥发时间30s,凝固浴的组成为氯化钠:去离子水=5:95,涂层量5-7g/m~2.采用优化工艺制得的洁净服面料,滤尘性高达90%,透湿和透气性也较好.%Polyester cleanroom fabrics were prepared by wet coating process using polyvinylidene fluoride. The effects of process conditions on the coated fabric properties were studied. It was found that the optimum process conditions were as fol-lows: PVDF mass fraction 14%, LiCI 3%, pre-evaporating time 30 s, the composition of coagulation bath NaCI: H_2O =5 :95,coating amounts 5 ~ 7 g/m~2. The particle filtration of the dustproof fabric was as high as 90%; the moisture and air permeabili-ty were excellent meanwhile.

  8. Double permeability peaks in Ce9Fe91films with in-plane uniaxial anisotropy

    Science.gov (United States)

    Zhou, Xueyun; Yao, Dongsheng; Hou, Cuiling; Chen, Rong; Shen, Hong

    2017-09-01

    Ce9Fe91films were fabricated at different temperature by Rf magnetron sputtering. The static and dynamic magnetic properties of these films have been investigated in details. The results reveal that the two films prepared at 293 K and 623 K with the critical film thickness exhibit weak stripe domains and a small perpendicular anisotropy, and their correlated dynamic permeability spectra show one resonance peak, implying the coherent precession of magnetization at such critical thickness. However, the film prepared at 523 K possesses an in-plane uniaxial anisotropy and lower coercive field. And the permeability spectrum displays two peaks, which can be ascribed to the coexistence of the rotatable anisotropy and in-plane uniaxial anisotropy.

  9. Isotropic negative permeability composite based on Mie resonance of the BST-MgO dielectric medium

    Institute of Scientific and Technical Information of China (English)

    ZHAO Qian; KANG Lei; DU Bo; ZHAO HongJie; XIE Qin; LI Bo; ZHOU Ji; LI LongTu; MENG YongGang

    2008-01-01

    Isotropic negative permeability composite, composed of BST-MgO dielectric cubes with high permit-tivity dispersed in the Teflon substrate with low permittivity, was designed and fabricated based on Mie resonance and the effective medium theory. Measurements and simulations showed that the dielectric composite exhibited a strong sub-wavelength magnetic resonance at the first Mie resonance and possessed isotropic negative permeability, which resulted from the displacement current excited in the cubes. The dielectric particle was equivalent to a magnetic dipole at the magnetic resonance, which could be adjusted by the size and permitllvity of the particles. It may provide a convenient method to design isotropic metamaterials and invisible cloak at infrared and visible frequencies.

  10. Permeability Measurements On Hot Rock Samples

    Science.gov (United States)

    Mueller, S.; Spieler, O.; Scheu, B.; Dingwell, D. B.

    Gas permeability is an important issue with regards to the explosive behaviour of Si- rich volcanoes. It directly affects the gas pressure within the volcano which influences the eruptive behaviour of the volcano. To date permeability measurements have only been performed on cold porous rocks (e.g. Eichelberger et al. 1986, Klug &Cashman 1996), because measurements with higher temperatures are not possible with common gas permeameters. Investigating the permeability of volcanic rocks in a hot state (up to 850 C) provides a better insight into the degassing processes under natural condi- tions. Therefore, any new experimental setup is expected to yield information about the temperature dependency of permeability in volcanic rocks. The present experi- ments have been performed on samples with a wide range of porosities. The samples were collected from block-and-ash flows on Merapi (Indonesia), Unzen (Japan) and pumices on Lipari Island (Italy). Permeabiltiy was measured using a modified setup of the fragmentation apparatus. A cylindrical rock sample (Æ = 25mm, l = 60 mm), glued gas tight in a sample container, was placed in a steel autoclave. Below the sample was a defined volume of argon gas at a known pressure. After the rupture of a diaphragm, the pressure above the sample drops rapidly to atmospheric conditions and the pres- surized gas flows through the porous rock sample until the pressure is equalized. The length of time from the beginning of the pressure drop to equilization delivers the basis for the calculation of the gas flow rate. The measurements we have performed at room temperature and at 850C to study the temperature dependency of the permeability.

  11. Air Pollution

    Science.gov (United States)

    Air pollution is a mixture of solid particles and gases in the air. Car emissions, chemicals from factories, ... Ozone, a gas, is a major part of air pollution in cities. When ozone forms air pollution, it's ...

  12. Simultaneous estimation of relative permeability and porosity/permeability fields by history matching production data

    Energy Technology Data Exchange (ETDEWEB)

    Eydinov, D. [Scandpower, Kjeller (Norway); Gao, G. [Chevron, San Ramon, CA (United States); Li, G.; Reynolds, A.C. [Tulsa Univ., Tulsa, OK (United States)

    2007-07-01

    Relative permeability curves are typically obtained through core flood tests. This paper provided details of a procedure that used automatic history matching of 3-phase flow production data to estimate permeability curves with grid block porosities. The method used a B-spline approximation to represent sets of permeability curves with a log transformation of parameters to ensure that curves were monotonic or convex. It was assumed that the model vector was a multivariate Gaussian distribution. The history matching problem was considered in a Bayesian framework. The method was then compared with a power law model using the same data from a synthetic reservoir model. Results showed that the B-spline model obtained more accurate permeability curves than the power law model. The randomized maximum likelihood (RML) method was used to quantify uncertainties in the model parameters. 19 refs., 17 figs.

  13. A Novel Empirical Equation for Relative Permeability in Low Permeability Reservoirs☆

    Institute of Scientific and Technical Information of China (English)

    Yulei Ge; Shurong Li; Kexin Qu

    2014-01-01

    In this paper, a novel empirical equation is proposed to calculate the relative permeability of low permeability res-ervoir. An improved item is introduced on the basis of Rose empirical formula and Al-Fattah empirical formula, with one simple model to describe oil/water relative permeability. The position displacement idea of bare bones particle swarm optimization is applied to change the mutation operator to improve the RNA genetic algorithm. The param-eters of the new empirical equation are optimized with the hybrid RNA genetic algorithm (HRGA) based on the ex-perimental data. The data is obtained from a typical low permeability reservoir wel 54 core 27-1 in GuDong by unsteady method. We carry out matlab programming simulation with HRGA. The comparison and error analysis show that the empirical equation proposed is more accurate than the Rose empirical formula and the exponential model. The generalization of the empirical equation is also verified.

  14. Analysis of the Porosity Changing after Moisture Absorption in Functional Knitted Fabrics

    Institute of Scientific and Technical Information of China (English)

    DU Yan-feng; SHEN Wei; FENG Xun-wei

    2007-01-01

    The paper analyses the effect of stitch geometricalmodality changing after moisture absorption on the porosityof knitted fabrics, and educes the formulas between porosityand stitch parameters. Regarding as the cell stitch, theincreasing of yam diameter brings the porosity decreasingand the fabric shrinking in the wale direction. While thediameter keeps invariability, the yarn elongating brings thefabric humping up as well as the increasing porosity. Theair-permeability experiments have been conducted to validatethe theoretical analysis, and there is reasonable agreementbetween the theories and experiments.

  15. Plastron Respiration Using Commercial Fabrics

    Directory of Open Access Journals (Sweden)

    Shaun Atherton

    2014-01-01

    Full Text Available A variety of insect and arachnid species are able to remain submerged in water indefinitely using plastron respiration. A plastron is a surface-retained film of air produced by surface morphology that acts as an oxygen-carbon dioxide exchange surface. Many highly water repellent and hydrophobic surfaces when placed in water exhibit a silvery sheen which is characteristic of a plastron. In this article, the hydrophobicity of a range of commercially available water repellent fabrics and polymer membranes is investigated, and how the surface of the materials mimics this mechanism of underwater respiration is demonstrated allowing direct extraction of oxygen from oxygenated water. The coverage of the surface with the plastron air layer was measured using confocal microscopy. A zinc/oxygen cell is used to consume oxygen within containers constructed from the different membranes, and the oxygen consumed by the cell is compared to the change in oxygen concentration as measured by an oxygen probe. By comparing the membranes to an air-tight reference sample, it was found that the membranes facilitated oxygen transfer from the water into the container, with the most successful membrane showing a 1.90:1 ratio between the cell oxygen consumption and the change in concentration within the container.

  16. Multifunctional non-woven fabrics of interfused graphene fibres.

    Science.gov (United States)

    Li, Zheng; Xu, Zhen; Liu, Yingjun; Wang, Ran; Gao, Chao

    2016-11-30

    Carbon-based fibres hold promise for preparing multifunctional fabrics with electrical conductivity, thermal conductivity, permeability, flexibility and lightweight. However, these fabrics are of limited performance mainly because of the weak interaction between fibres. Here we report non-woven graphene fibre fabrics composed of randomly oriented and interfused graphene fibres with strong interfibre bonding. The all-graphene fabrics obtained through a wet-fusing assembly approach are porous and lightweight, showing high in-plane electrical conductivity up to ∼2.8 × 10(4 )S m(-1) and prominent thermal conductivity of ∼301.5 W m(-1 )K(-1). Given the low density (0.22 g cm(-3)), their specific electrical and thermal conductivities set new records for carbon-based papers/fabrics and even surpass those of individual graphene fibres. The as-prepared fabrics are further used as ultrafast responding electrothermal heaters and durable oil-adsorbing felts, demonstrating their great potential as high-performance and multifunctional fabrics in real-world applications.

  17. Quantitative Prediction of Structural Fractures in Low Permeability Reservoir

    Institute of Scientific and Technical Information of China (English)

    Zeng Lianbo; Tian Chonglu

    1996-01-01

    @@ Low -permeability fractured reservoirs will become increasingly prominent along with the enhanced exploration extent and the emerging moderate-high water content in most of the moderate-high permeability reservoirs of the oil fields in eastern China.

  18. Considerations about the internodal permeability evaluation in reservoir simulation

    Energy Technology Data Exchange (ETDEWEB)

    Cordazzo, Jonas; Maliska, Clovis R. [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica. Lab. Computacional de Dinamica dos Fluidos]. E-mails: jonas@sinmec.ufsc.br; maliska@sinmec.ufsc.br; Romeu, Regis K. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas]. E-mail: regis@cenpes.petrobras.com.br

    2003-07-01

    This work reports some numerical problems caused by the using of harmonic average in the inter nodal permeability calculation during the petroleum reservoir simulation. This paper begins with a brief review, showing, in the sequence the approach used by commercial simulators in interpreting the permeability map. Then, the results of using harmonic averaging to determine the inter nodal permeability are presented by solving the 2D chessboard problem. Finally, the Element-based Finite Volume Method (EbFVM) is analyzed considering the permeability evaluation. It is demonstrated that this method, besides dealing with triangular and quadrilateral elements, can also deal with the permeability map without averaging. The two possibilities of storing the physical properties and their implications in the permeability evaluation are addressed. The permeability storage in the center of the elements, instead of in the center of control volumes, avoids the need of weighting the permeability values in the interfaces of the control volumes. (author)

  19. Influence of salinity on permeability characteristics of marine sediments

    Digital Repository Service at National Institute of Oceanography (India)

    Jose, U.V.; Bhat, S.T.; Nayak, B.U.

    that permeability increases with an increase in salt concentration for a given void ratio. This is explained by diffused double layer theory. Also, the rate of increase in permeability decreases with increase in salt concentration. The effect of salt concentration...

  20. Intestinal permeability study of minoxidil: assessment of minoxidil as a high permeability reference drug for biopharmaceutics classification.

    Science.gov (United States)

    Ozawa, Makoto; Tsume, Yasuhiro; Zur, Moran; Dahan, Arik; Amidon, Gordon L

    2015-01-05

    The purpose of this study was to evaluate minoxidil as a high permeability reference drug for Biopharmaceutics Classification System (BCS). The permeability of minoxidil was determined in in situ intestinal perfusion studies in rodents and permeability studies across Caco-2 cell monolayers. The permeability of minoxidil was compared with that of metoprolol, an FDA reference drug for BCS classification. In rat perfusion studies, the permeability of minoxidil was somewhat higher than that of metoprolol in the jejunum, while minoxidil showed lower permeability than metoprolol in the ileum. The permeability of minoxidil was independent of intestinal segment, while the permeability of metoprolol was region-dependent. Similarly, in mouse perfusion study, the jejunal permeability of minoxidil was 2.5-fold higher than that of metoprolol. Minoxidil and metoprolol showed similar permeability in Caco-2 study at apical pH of 6.5 and basolateral pH of 7.4. The permeability of minoxidil was independent of pH, while metoprolol showed pH-dependent transport in Caco-2 study. Minoxidil exhibited similar permeability in the absorptive direction (AP-BL) in comparison with secretory direction (BL-AP), while metoprolol had higher efflux ratio (ER > 2) at apical pH of 6.5 and basolateral pH of 7.4. No concentration-dependent transport was observed for either minoxidil or metoprolol transport in Caco-2 study. Verapamil did not alter the transport of either compounds across Caco-2 cell monolayers. The permeability of minoxidil was independent of both pH and intestinal segment in intestinal perfusion studies and Caco-2 studies. Caco-2 studies also showed no involvement of carrier mediated transport in the absorption process of minoxidil. These results suggest that minoxidil may be an acceptable reference drug for BCS high permeability classification. However, minoxidil exhibited higher jejunal permeability than metoprolol and thus to use minoxidil as a reference drug would raise the

  1. Effects of Fiber Denier, Fiber Cross-Sectional Shape and Fabric Density on Acoustical Behavior of Vertically Lapped Nonwoven Fabrics

    Directory of Open Access Journals (Sweden)

    Mevlut Tascan, Ph.D.

    2008-06-01

    Full Text Available Acoustical insulation and absorption properties of nonwoven fabrics depend on fiber geometry and fiber arrangement within the fabric structure. The different structures of the fibers result in different total surface areas of nonwoven fabrics. Nonwoven fabrics such as vertically lapped fabrics are ideal materials for use as acoustical insulation products, because they have high total surface. Vertically lapped nonwoven technology consists of carding, perpendicular layering of the carded webs, and through-air bonding using synthetic binder fibers. The surface area of the fabric is directly related to the denier and cross-sectional shape of the fibers in the fabric. Smaller deniers yield more fibers per unit weight of the material, higher total fiber surface area, and greater possibilities for a sound wave to interact with the fibers in the fabric structure.The research in the literature uses two methods for measuring acoustical properties of fabric materials: the impedance tube and reverberation room method. Small test samples are in the impedance tube method and sound absorption coefficient is determined at each frequency. Large reverberation rooms and large test samples are used for the reverberation room method. A direct comparative acoustical properties measurement device that was designed and fabricated at Clemson University School of Materials Science & Engineering was used to measure acoustical insulation in this research. This paper provides a description of the measurement devices and acoustical measurement data for vertically lapped nonwoven fabrics made from three different polyester fiber shape and two denier levels.

  2. Fabricating architectural volume

    DEFF Research Database (Denmark)

    Feringa, Jelle; Søndergaard, Asbjørn

    2015-01-01

    The 2011 edition of Fabricate inspired a number of collaborations, this article seeks to highlight three of these. There is a common thread amongst the projects presented: sharing the ambition to close the rift between design and fabrication while incorporating structural design aspects early on...

  3. 21 CFR 886.5916 - Rigid gas permeable contact lens.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Rigid gas permeable contact lens. 886.5916 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5916 Rigid gas permeable contact lens. (a) Identification. A rigid gas permeable contact lens is a device intended to be worn...

  4. Determination of permeability using fractal method for porous media

    Institute of Scientific and Technical Information of China (English)

    施明恒; 陈永平

    2001-01-01

    A theoretical formulation was developed to express permeability as a function of different fractal dimensions and other scales for porous media . The effective fractal void ratio, the spectral dimension and the fractal dimension of particle mass distribution were introduced. The permeabilities for different soils in China are calculated. The predicted permeability for rice soil was compared with the measured data available in literature.

  5. Scanning electron microscopy and dentinal permeability analysis of smear layer.

    Science.gov (United States)

    Prati, C; Mongiorgi, R; Pashley, D H; Riva di Sanseverino, L

    1991-05-01

    The aim of the present study was to evaluate the surface morphology and the permeability of dentine after different acid treatments: polyacrylic acid, maleic acid, phosphoric acid and saline solution as control. Dentine permeability was expressed as hydraulic conductance. All the acid treatments removed the smear layer and increased the dentine permeability.

  6. High-resolution nanopatterning of biodegradable polylactide by thermal nanoimprint lithography using gas permeable mold

    Directory of Open Access Journals (Sweden)

    Satoshi Takei

    2017-03-01

    Full Text Available We report high-resolution (150 nm nanopatterning of biodegradable polylactide by thermal nanoimprint lithography using dichloromethane as a volatile solvent for improving the liquidity and a porous cyclodextrin-based gas-permeable mold. This study demonstrates the high-resolution patterning of polylactic acid and other non-liquid functional materials with poor fluidity by thermal nanoimprinting. Such a patterning is expected to expand the utility of thermal nanoimprint lithography and fabricate non-liquid functional materials suitable for eco-friendly and biomedical applications.

  7. High-resolution nanopatterning of biodegradable polylactide by thermal nanoimprint lithography using gas permeable mold

    Science.gov (United States)

    Takei, Satoshi; Hanabata, Makoto

    2017-03-01

    We report high-resolution (150 nm) nanopatterning of biodegradable polylactide by thermal nanoimprint lithography using dichloromethane as a volatile solvent for improving the liquidity and a porous cyclodextrin-based gas-permeable mold. This study demonstrates the high-resolution patterning of polylactic acid and other non-liquid functional materials with poor fluidity by thermal nanoimprinting. Such a patterning is expected to expand the utility of thermal nanoimprint lithography and fabricate non-liquid functional materials suitable for eco-friendly and biomedical applications.

  8. Electrostatically gated membrane permeability in inorganic protocells

    Science.gov (United States)

    Li, Mei; Harbron, Rachel L.; Weaver, Jonathan V. M.; Binks, Bernard P.; Mann, Stephen

    2013-06-01

    Although several strategies are now available to produce functional microcompartments analogous to primitive cell-like structures, little progress has been made in generating protocell constructs with self-controlled membrane permeability. Here we describe the preparation of water-dispersible colloidosomes based on silica nanoparticles and delineated by a continuous semipermeable inorganic membrane capable of self-activated, electrostatically gated permeability. We use crosslinking and covalent grafting of a pH-responsive copolymer to generate an ultrathin elastic membrane that exhibits selective release and uptake of small molecules. This behaviour, which depends on the charge of the copolymer coronal layer, serves to trigger enzymatic dephosphorylation reactions specifically within the protocell aqueous interior. This system represents a step towards the design and construction of alternative types of artificial chemical cells and protocell models based on spontaneous processes of inorganic self-organization.

  9. Permeability of cork for water and ethanol.

    Science.gov (United States)

    Fonseca, Ana Luisa; Brazinha, Carla; Pereira, Helena; Crespo, Joao G; Teodoro, Orlando M N D

    2013-10-01

    Transport properties of natural (noncompressed) cork were evaluated for water and ethanol in both vapor and liquid phases. The permeability for these permeants has been measured, as well as the sorption and diffusion coefficients. This paper focuses on the differences between the transport of gases' relevant vapors and their liquids (water and ethanol) through cork. A transport mechanism of vapors and liquids is proposed. Experimental evidence shows that both vapors and liquids permeate not only through the small channels across the cells (plasmodesmata), as in the permeation of gases, but also through the walls of cork cells by sorption and diffusion as in dense membranes. The present study also shows that cork permeability for gases was irreversibly and drastically decreased after cork samples were exposed to ethanol or water in liquid phase.

  10. Anisotropic permeability in deterministic lateral displacement arrays

    CERN Document Server

    Vernekar, Rohan; Loutherback, Kevin; Morton, Keith; Inglis, David

    2016-01-01

    We investigate anisotropic permeability of microfluidic deterministic lateral displacement (DLD) arrays. A DLD array can achieve high-resolution bimodal size-based separation of micro-particles, including bioparticles such as cells. Correct operation requires that the fluid flow remains at a fixed angle with respect to the periodic obstacle array. We show via experiments and lattice-Boltzmann simulations that subtle array design features cause anisotropic permeability. The anisotropy, which indicates the array's intrinsic tendency to induce an undesired lateral pressure gradient, can lead to off-axis flows and therefore local changes in the critical separation size. Thus, particle trajectories can become unpredictable and the device useless for the desired separation duty. We show that for circular posts the rotated-square layout, unlike the parallelogram layout, does not suffer from anisotropy and is the preferred geometry. Furthermore, anisotropy becomes severe for arrays with unequal axial and lateral gaps...

  11. Monitoring pulmonary vascular permeability using radiolabeled transferrin

    Energy Technology Data Exchange (ETDEWEB)

    Basran, G.S.; Hardy, J.G.

    1988-07-01

    A simple, noninvasive technique for monitoring pulmonary vascular permeability in patients in critical care units is discussed. High vascular permeability is observed in patients with clinically defined adult respiratory distress syndrome (ARDS) but not in patients with hydrostatic pulmonary edema or in patients with minor pulmonary insults who are considered to be at risk of developing ARDS. The technique has been used in the field of therapeutics and pharmacology to test the effects of the putative antipermeability agents methylprednisolone and terbutaline sulfate. There appears to be a good correlation between the acute inhibitory effect of either drug on transferrin exudation and patient prognosis. Thus, a byproduct of such drug studies may be an index of survival in patients with established ARDS.

  12. Permittivity and permeability tensors for cloaking applications

    CERN Document Server

    Choudhury, Balamati; Jha, Rakesh Mohan

    2016-01-01

    This book is focused on derivations of analytical expressions for stealth and cloaking applications. An optimal version of electromagnetic (EM) stealth is the design of invisibility cloak of arbitrary shapes in which the EM waves can be controlled within the cloaking shell by introducing a prescribed spatial variation in the constitutive parameters. The promising challenge in design of invisibility cloaks lies in the determination of permittivity and permeability tensors for all the layers. This book provides the detailed derivation of analytical expressions of the permittivity and permeability tensors for various quadric surfaces within the eleven Eisenhart co-ordinate systems. These include the cylinders and the surfaces of revolutions. The analytical modeling and spatial metric for each of these surfaces are provided along with their tensors. This mathematical formulation will help the EM designers to analyze and design of various quadratics and their hybrids, which can eventually lead to design of cloakin...

  13. Gravity filtration of suspensions: permeability effects

    Science.gov (United States)

    Soori, Tejaswi; Wang, Mengyu; Ward, Thomas

    2015-11-01

    This paper examines the filtration rates of mono-modal suspensions as a function of time and a cake layer builds up through theory and experimentation. Darcy's Law, which describes fluid flow through porous media, was applied along with the Kynch theory of sedimentation, which provides the basis for analyzing low concentration (ϕ filter media. A CCD camera was used to capture images of the cake formation and fluid drainage processes, and subsequent image and theoretical analysis found the fluid flow experienced a constant pressure loss due to the permeability of the filter media, whereas the experienced pressure loss due to the cake formation varies as a function of time, ϕ and d. The rate of cake formation was also found to be independent of ϕ but dependent on d which can be attributed to a change in porosity affecting permeability. Studies on similar systems with multi-modal suspensions are in-progress.

  14. Changes of Intestinal Permeability in Cholelithiasis Patients

    Institute of Scientific and Technical Information of China (English)

    Shao-long Sun; Shuo-dong Wu; Dong-xu Cui; Bao-lin Liu; Xian-wei Dai

    2009-01-01

    @@ In normal condition,intestine mucosa possesses barrier function.When the barrier function of intestine mucosa was damaged,intestinal bacteria,endotoxin,or other substances would enter blood.It is generally accepted that biliary bacteria origins from the intestine either via duodenal papilla or intestinal mucosa.In this study,we aimed to investigate the intestinal permeability changes of cholelithiasis patients to elucidate the possible pathogenesis of cholelithiasis.

  15. Cation Permeability in Soybean Aleurone Layer

    OpenAIRE

    Noda, Hiroko; Fukuda, Mitsuru

    1998-01-01

    The permeation of water and ions into bean seeds is essential for processing and cooking of beans. The permeability of cations, K, Na, Ca, and Mg ions, into soybean seed tissue, especially aleurone layer, during water uptake was investigated to characterize the ion permeation into soybeans. Aleurone layers and seed coats contained relatively high concentration of endogenous K and Ca ions, and endogenous Ca ion, respectively. The amounts of Ca ion entered seed coats and aleurone layers were gr...

  16. Creating permeable fracture networks for EGS: Engineered systems versus nature

    Energy Technology Data Exchange (ETDEWEB)

    Stephen L Karner

    2005-10-01

    The United States Department of Energy has set long-term national goals for the development of geothermal energy that are significantly accelerated compared to historical development of the resource. To achieve these goals, it is crucial to evaluate the performance of previous and existing efforts to create enhanced geothermal systems (EGS). Two recently developed EGS sites are evaluated from the standpoint of geomechanics. These sites have been established in significantly different tectonic regimes: 1. compressional Cooper Basin (Australia), and 2. extensional Soultz-sous-Fôrets (France). Mohr-Coulomb analyses of the stimulation procedures employed at these sites, coupled with borehole observations, indicate that pre-existing fractures play a significant role in the generation of permeability networks. While pre-existing fabric can be exploited to produce successful results for geothermal energy development, such fracture networks may not be omnipresent. For mostly undeformed reservoirs, it may be necessary to create new fractures using processes that merge existing technologies or use concepts borrowed from natural hydrofracture examples (e.g. dyke swarms).

  17. A Reconciliation of Packed Column Permeability Data: Column Permeability as a Function of Particle Porosity

    Directory of Open Access Journals (Sweden)

    Hubert M. Quinn

    2014-01-01

    Full Text Available In his textbook teaching of packed bed permeability, Georges Guiochon uses mobile phase velocity as the fluid velocity term in his elaboration of the Darcy permeability equation. Although this velocity frame makes a lot of sense from a thermodynamic point of view, it is valid only with respect to permeability at a single theoretical boundary condition. In his more recent writings, however, Guiochon has departed from his long-standing mode of discussing permeability in terms of the Darcy equation and has embraced the well-known Kozeny-Blake equation. In this paper, his teaching pertaining to the constant in the Kozeny-Blake equation is examined and, as a result, a new correlation coefficient is identified and defined herein based on the velocity frame used in his teaching. This coefficient correlates pressure drop and fluid velocity as a function of particle porosity. We show that in their experimental protocols, Guiochon et al. have not adhered to a strict material balance of permeability which creates a mismatch of particle porosity and leads to erroneous conclusions regarding the value of the permeability coefficient in the Kozeny-Blake equation. By correcting the experimental data to properly reflect particle porosity we reconcile the experimental results of Guiochon and Giddings, resulting in a permeability reference chart which is presented here for the first time. This reference chart demonstrates that Guiochon’s experimental data, when properly normalized for particle porosity and other related discrepancies, corroborates the value of 267 for the constant in the Kozeny-Blake equation which was derived by Giddings in 1965.

  18. Effects of the Addition of Sodium Alginate and the Concentration of Calcium Chloride on the Properties of Composite Nonwoven Fabrics

    Directory of Open Access Journals (Sweden)

    Lou Ching-Wen

    2016-01-01

    Full Text Available Nonwoven fabrics have merits, and for example, they can be simply and quickly processed with a variety of materials and an easily changeable manufacturing process. This study aims to examine the influences of the addition of sodium alginate (SA and the concentration of calcium chloride (CaCl2 on the properties of the composite nonwoven fabrics. Chitosan (CS micro-particles and SA solution are cross-linked with CaCl2 with various concentrations, combined with farir heat preservative staples (FT/cotton (C nonwoven fabrics, and then freeze-dried to form CS/SA/FT/C composite nonwoven fabrics. Afterwards, physical property tests are performed on the resulting composite nonwoven fabrics to determine their properties as related to various concentrations of CaCl2. The addition of SA decreases the water vapor permeability of FT/C nonwoven fabrics by 15 %, but the concentrations of CaCl2 do not influence the water vapor permeability. Compared to FT/C nonwoven fabrics, CS/SA/FT/C composite nonwoven fabrics have significantly lower water absorbency and water vapor permeability, but a greater stiffness.

  19. Permeability- and Surface-Energy-Tunable Polyurethane Acrylate Molds for Capillary Force Lithography.

    Science.gov (United States)

    Suh, Dongchul; Tak, Hyowon; Choi, Se-jin; Kim, Tae-il

    2015-11-04

    A permeability- and surface-energy-controllable polyurethane acrylate (PUA) mold, a "capillary-force material (CFM)" mold, is introduced for capillary-force lithography (CFL). In CFL, the surface energy and gas permeability of the mold are crucial. However, the modulation of these two main factors at a time is difficult. Here, we introduce new CFM molds in which the surface energy and permeability can be modified by controlling the degree of cross-linking of the CFM. As the degree of cross-linking of the CFM mold increases, the surface energy and air permeability decrease. The high average functionality of the mold material makes it possible to produce patterns relatively finely and rapidly due to the high rate of capillary rise and stiffness, and the low functionality allows for patterns to form on a curved surface with conformal contact. CFMs with different functionality and controllable-interfacial properties will extend the capabilities of capillary force lithography to overcome the geometric limitations of patterning on a scale below 100 nm and micro- and nanopatterning on the curved region.

  20. Change in Properties of Wool Fabrics by Low Temperature Plasma Treatment

    OpenAIRE

    奥野, 温子; 江川, 文; 浅野, 昌美; 吉田, 恭子; 安田, 武

    1999-01-01

    The effect of plasma treatment using various gases on the end use properties of wool fabrics was investigated. The results are summarized as follows: The etching by air plasma generated remarkable irregularities on the surface of the wool fabrics, and the static friction coefficient tended to increase. However, the treatment softened the fabric handling. On the other hand, the plasma treatment using CF_4 and N_2 gas hardly changed the fabric handling in spite of a large weight loss of the sam...

  1. Total Wear Comfort Index as an Objective Parameter for Characterization of Overall Wearability of Cotton Fabrics

    Directory of Open Access Journals (Sweden)

    Sheela Raj

    2009-12-01

    Full Text Available The state of physical comfort experienced by awearer under a given environmental condition isgreatly influenced by the tactile, thermal andmoisture transport properties of the fabric. An indepthstudy carried out to understand fabric handleand wear comfort in relation to fiber, yarn and fabricstructural parameter is presented in this paper. Theresults obtained from this study provide an invaluableinsight into engineering of required quality featuresinto the cotton fabrics so as to provide optimum wearcomfort. A comprehensive grading indexincorporating the transport attributes (air permeabilityand moisture and thermal transport of the fabric hasbeen derived to grade end use efficiency of the fabricjuxtaposing with fabric hand, which would finallydecide the overall quality of the apparel fabric.

  2. A computational assessment of the permeability and salt rejection of carbon nanotube membranes and their application to water desalination.

    Science.gov (United States)

    Thomas, Michael; Corry, Ben

    2016-02-13

    Membranes made from nanomaterials such as nanotubes and graphene have been suggested to have a range of applications in water filtration and desalination, but determining their suitability for these purposes requires an accurate assessment of the properties of these novel materials. In this study, we use molecular dynamics simulations to determine the permeability and salt rejection capabilities for membranes incorporating carbon nanotubes (CNTs) at a range of pore sizes, pressures and concentrations. We include the influence of osmotic gradients and concentration build up and simulate at realistic pressures to improve the reliability of estimated membrane transport properties. We find that salt rejection is highly dependent on the applied hydrostatic pressure, meaning high rejection can be achieved with wider tubes than previously thought; while membrane permeability depends on salt concentration. The ideal size of the CNTs for desalination applications yielding high permeability and high salt rejection is found to be around 1.1 nm diameter. While there are limited energy gains to be achieved in using ultra-permeable CNT membranes in desalination by reverse osmosis, such membranes may allow for smaller plants to be built as is required when size or weight must be minimized. There are diminishing returns in further increasing membrane permeability, so efforts should focus on the fabrication of membranes containing narrow or functionalized CNTs that yield the desired rejection or selection properties rather than trying to optimize pore densities.

  3. Multiple—tube Permeable Element for Combined Blowing Converter

    Institute of Scientific and Technical Information of China (English)

    YANGWen-yuan; XUWei-hua; 等

    1994-01-01

    The method consisting of cold test and hot simulating has been proved to be reliable for designing permeable ele-ments.The carbon-magnesia multiple-tube permeable ele-ments which are formed by isostatical pressure have higher density,high heat resistance and good thermoshock resis-tance,The brickwork ,maintenance and erosion meha-nism of permeable elements were studied.The tehnology of combined blowing wa established based on the peculiari-ties of semi-steel refining at Panzhihua Irom& Steel Co.(PZISC).The service life of permeable elements reahed 600 heats,that means the permeable elements can work synchronitially with converter lining.

  4. New polymorphous computing fabric.

    Energy Technology Data Exchange (ETDEWEB)

    Wolinski, C. (Christophe); Gokhale, M. (Maya); McCabe, K. P. (Kevin P.)

    2002-01-01

    This paper introduces a new polymorphous computing Fabric well suited to DSP and Image Processing and describes its implementation on a Configurable System on a Chip (CSOC). The architecture is highly parameterized and enables customization of the synthesized Fabric to achieve high performance for a specific class of application. For this reason it can be considered to be a generic model for hardware accelerator synthesis from a high level specification. Another important innovation is the Fabric uses a global memory concept, which gives the host processor random access to all the variables and instructions on the Fabric. The Fabric supports different computing models including MIMD, SPMD and systolic flow and permits dynamic reconfiguration. We present a specific implementation of a bank of FIR filters on a Fabric composed of 52 cells on the Altera Excalibur ARM running at 33 MHz. The theoretical performance of this Fabric is 1.8 GMACh. For the FIR application we obtain 1.6 GMAC/s real performance. Some automatic tools have been developed like the tool to provide a host access utility and assembler.

  5. [Effects of air pollution on pulmonary blood vessels].

    Science.gov (United States)

    Zaiats, L M

    1995-01-01

    The experiments on white rats provided histological and electron-microscopic evidence on the damage which may be done to pulmonary vessels by the chemicals present in polluted atmospheric air. There appeared impairment of vascular permeability and perivascular edema late in the experiment course (within 3 months). Alveolar capillaries proved most sensitive to air pollution.

  6. Permeability and permeability anisotropy in Crab Orchard sandstone: Experimental insights into spatio-temporal effects

    Science.gov (United States)

    Gehne, Stephan; Benson, Philip M.

    2017-08-01

    Permeability in tight crustal rocks is primarily controlled by the connected porosity, shape and orientation of microcracks, the preferred orientation of cross-bedding, and sedimentary features such as layering. This leads to a significant permeability anisotropy. Less well studied, however, are the effects of time and stress recovery on the evolution of the permeability hysteresis which is becoming increasingly important in areas ranging from fluid migration in ore-forming processes to enhanced resource extraction. Here, we report new data simulating spatio-temporal permeability changes induced using effective pressure, simulating burial depth, on a tight sandstone (Crab Orchard). We find an initially (measured at 5 MPa) anisotropy of 2.5% in P-wave velocity and 180% in permeability anisotropy is significantly affected by the direction of the effective pressure change and cyclicity; anisotropy values decrease to 1% and 10% respectively after 3 cycles to 90 MPa and back. Furthermore, we measure a steadily increasing recovery time (10-20 min) for flow parallel to cross-bedding, and a far slower recovery time (20-50 min) for flow normal to cross-bedding. These data are interpreted via strain anisotropy and accommodation models, similar to the ;seasoning; process often used in dynamic reservoir extraction.

  7. Evaluating Permeability Enchancement Using Electrical Techniques

    Energy Technology Data Exchange (ETDEWEB)

    John W. Pritchett

    2008-09-01

    Enhanced Geothermal Systems (EGS) development projects involve the artificial stimulation of relatively impermeable high-temperature underground regions (at depths of 2-4 kilometers or more) to create sufficient permeability to permit underground fluid circulation, so that hot water can be withdrawn from production wells and used to generate electric power. Several major research projects of this general type have been undertaken in the past in New Mexico (Fenton Hill), Europe, Japan and Australia. Recent U.S. activities along these lines focus mainly on stimulating peripheral areas of existing operating hydrothermal fields rather than on fresh 'greenfield' sites, but the long-term objective of the Department of Energy's EGS program is the development of large-scale power projects based on EGS technology (MIT, 2006; NREL, 2008). Usually, stimulation is accomplished by injecting water into a well at high pressure, enhancing permeability by the creation and propagation of fractures in the surrounding rock (a process known as 'hydrofracturing'). Beyond just a motivation, low initial system permeability is also an essential prerequisite to hydrofracturing. If the formation permeability is too high, excessive fluid losses will preclude the buildup of sufficient pressure to fracture rock. In practical situations, the actual result of injection is frequently to re-open pre-existing hydrothermally-mineralized fractures, rather than to create completely new fractures by rupturing intact rock. Pre-existing fractures can often be opened using injection pressures in the range 5-20 MPa. Creation of completely new fractures will usually require pressures that are several times higher. It is preferable to undertake development projects of this type in regions where tectonic conditions are conducive to shear failure, so that when pre-existing fractures are pressurized they will fail by shearing laterally. If this happens, the fracture will often stay open

  8. Analysis of Basis Weight Uniformity of Microfiber Nonwovens and Its Impact on Permeability and Filtration Properties

    Science.gov (United States)

    Amirnasr, Elham

    It is widely recognized that nonwoven basis weight non-uniformity affects various properties of nonwovens. However, few studies can be found in this topic. The development of uniformity definition and measurement methods and the study of their impact on various web properties such as filtration properties and air permeability would be beneficial both in industrial applications and in academia. They can be utilized as a quality control tool and would provide insights about nonwoven behaviors that cannot be solely explained by average values. Therefore, for quantifying nonwoven web basis weight uniformity we purse to develop an optical analytical tool. The quadrant method and clustering analysis was utilized in an image analysis scheme to help define "uniformity" and its spatial variation. Implementing the quadrant method in an image analysis system allows the establishment of a uniformity index that can be used to quantify the degree of uniformity. Clustering analysis has also been modified and verified using uniform and random simulated images with known parameters. Number of clusters and cluster properties such as cluster size, member and density was determined. We also utilized this new measurement method to evaluate uniformity of nonwovens produced with different processes and investigated impacts of uniformity on filtration and permeability. The results of quadrant method shows that uniformity index computed from quadrant method demonstrate a good range for non-uniformity of nonwoven webs. Clustering analysis is also been applied on reference nonwoven with known visual uniformity. From clustering analysis results, cluster size is promising to be used as uniformity parameter. It is been shown that non-uniform nonwovens has provide lager cluster size than uniform nonwovens. It was been tried to find a relationship between web properties and uniformity index (as a web characteristic). To achieve this, filtration properties, air permeability, solidity and

  9. Effective stress law for the permeability of a limestone

    CERN Document Server

    Ghabezloo, Siavash; Guédon, Sylvine; Martineau, François

    2008-01-01

    The effective stress law for the permeability of a limestone is studied experimentally by performing constant head permeability tests in a triaxial cell with different conditions of confining pressure and pore pressure. Test results have shown that a pore pressure increase and a confining pressure decrease both result in an increase of the permeability, and that the effect of the pore pressure change on the variation of the permeability is more important than the effect of a change of the confining pressure. A power law is proposed for the variation of the permeability with the effective stress. The permeability effective stress coefficient increases linearly with the differential pressure and is greater than one as soon the differential pressure exceeds few bars. The test results are well reproduced using the proposed permeability-effective stress law. A conceptual pore-shell model based on a detailed observation of the microstructure of the studied limestone is proposed. This model is able to explain the ex...

  10. The Accelerated Test of Chloride Permeability of Concrete

    Institute of Scientific and Technical Information of China (English)

    TAN Ke-feng; ODD E Gjφrv

    2003-01-01

    The availability of accelerated chloride permeability test and the effect of w/c ratio, incorporation of silica fume, maximum aggregate size and aggregate type on the chloride permeability were studied. The mathematic analysis certifies that there is a linear relationship between accelerated test and natural diffusion. Test results show that the chloride permeability of concrete increases as w/c ratio increases whilst a limited amount of replacement of cement with silica fume, the chloride permeability decreases dramatically. The maximum aggregate size in the range of 8 to 25 mm seems also affect chloride permeability but with a much less significant level. The chloride permeability of silica fume lightweight aggregate concrete is very low, especially the concrete made with dry lightweight concrete. The chloride permeability can be evaluated by this accelerated test method.

  11. Upscaling of permeability field of fractured rock system: Numerical examples

    KAUST Repository

    Bao, K.

    2012-01-01

    When the permeability field of a given porous medium domain is heterogeneous by the existence of randomly distributed fractures such that numerical investigation becomes cumbersome, another level of upscaling may be required. That is such complex permeability field could be relaxed (i.e., smoothed) by constructing an effective permeability field. The effective permeability field is an approximation to the real permeability field that preserves certain quantities and provides an overall acceptable description of the flow field. In this work, the effective permeability for a fractured rock system is obtained for different coarsening scenarios starting from very coarse mesh all the way towards the fine mesh simulation. In all these scenarios, the effective permeability as well as the pressure at each cell is obtained. The total flux at the exit boundary is calculated in all these cases, and very good agreement is obtained.

  12. Objective Evaluation of Fabric Drape

    Institute of Scientific and Technical Information of China (English)

    XU Jun; YAO Mu

    2002-01-01

    On the basis of our previous research work, an expressing index was proposed for the lively degree of dynamic fabric drape. Meanwhile, the main factoranalysis for parameters of fabric drape was applied and the 5 main factors, comprehensive indexes of expressing aesthetics of fabric drape, were obtained. Through the scored diagrams of main factors of fabric drape aesthetics, 100 kinds of fabric samples could be identified and catalogued. A new method was found out for the objective evaluation of aesthetics of fabric drape.

  13. Permeability-porosity relationships of subduction zone sediments

    Science.gov (United States)

    Gamage, K.; Screaton, E.; Bekins, B.; Aiello, I.

    2011-01-01

    Permeability-porosity relationships for sediments from the northern Barbados, Costa Rica, Nankai, and Peru subduction zones were examined based on sediment type, grain size distribution, and general mechanical and chemical compaction history. Greater correlation was observed between permeability and porosity in siliciclastic sediments, diatom oozes, and nannofossil chalks than in nannofossil oozes. For siliciclastic sediments, grouping of sediments by percentage of clay-sized material yields relationships that are generally consistent with results from other marine settings and suggests decreasing permeability as percentage of clay-sized material increases. Correction of measured porosities for smectite content improved the correlation of permeability-porosity relationships for siliciclastic sediments and diatom oozes. The relationship between permeability and porosity for diatom oozes is very similar to the relationship in siliciclastic sediments, and permeabilities of both sediment types are related to the amount of clay-size particles. In contrast, nannofossil oozes have higher permeability values by 1.5 orders of magnitude than siliciclastic sediments of the same porosity and show poor correlation between permeability and porosity. More indurated calcareous sediments, nannofossil chalks, overlap siliciclastic permeabilities at the lower end of their measured permeability range, suggesting similar consolidation patterns at depth. Thus, the lack of correlation between permeability and porosity for nannofossil oozes is likely related to variations in mechanical and chemical compaction at shallow depths. This study provides the foundation for a much-needed global database with fundamental properties that relate to permeability in marine settings. Further progress in delineating controls on permeability requires additional carefully documented permeability measurements on well-characterized samples. ?? 2010 Elsevier B.V.

  14. Alloy Fabrication Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — At NETL’s Alloy Fabrication Facility in Albany, OR, researchers conduct DOE research projects to produce new alloys suited to a variety of applications, from gas...

  15. Experimental Fabrication Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Provides aviation fabrication support to special operations aircraft residing at Fort Eustis and other bases in the United States. Support is also provided to AATD...

  16. Fabric Structures Team Overview

    Science.gov (United States)

    2009-11-01

    SUPPLEMENTARY NOTES 6th Bi-Annual DOD JOCOTAS Meeting with Rigid & Soft Wall Shelter Industry & Indoor & Outdoor Exhibition, 2-4 Nov 2009, Panama City...Maintenance Shelter Demonstrated in July 09 • Designed and fabricated by Hunter Defense Technologies/Vertigo Shelters (prime), Johnson Outdoors ...Congressionally directed program with Nemo , Inc., Nashua, NH f• Designs include novel in latable airbeam technology and tensioned fabric/pole

  17. Nuclear Fabrication Consortium

    Energy Technology Data Exchange (ETDEWEB)

    Levesque, Stephen [EWI, Columbus, OH (United States)

    2013-04-05

    This report summarizes the activities undertaken by EWI while under contract from the Department of Energy (DOE) Office of Nuclear Energy (NE) for the management and operation of the Nuclear Fabrication Consortium (NFC). The NFC was established by EWI to independently develop, evaluate, and deploy fabrication approaches and data that support the re-establishment of the U.S. nuclear industry: ensuring that the supply chain will be competitive on a global stage, enabling more cost-effective and reliable nuclear power in a carbon constrained environment. The NFC provided a forum for member original equipment manufactures (OEM), fabricators, manufacturers, and materials suppliers to effectively engage with each other and rebuild the capacity of this supply chain by : Identifying and removing impediments to the implementation of new construction and fabrication techniques and approaches for nuclear equipment, including system components and nuclear plants. Providing and facilitating detailed scientific-based studies on new approaches and technologies that will have positive impacts on the cost of building of nuclear plants. Analyzing and disseminating information about future nuclear fabrication technologies and how they could impact the North American and the International Nuclear Marketplace. Facilitating dialog and initiate alignment among fabricators, owners, trade associations, and government agencies. Supporting industry in helping to create a larger qualified nuclear supplier network. Acting as an unbiased technology resource to evaluate, develop, and demonstrate new manufacturing technologies. Creating welder and inspector training programs to help enable the necessary workforce for the upcoming construction work. Serving as a focal point for technology, policy, and politically interested parties to share ideas and concepts associated with fabrication across the nuclear industry. The report the objectives and summaries of the Nuclear Fabrication Consortium

  18. Fabrics with tunable oleophobicity

    OpenAIRE

    McKinley, Gareth H.; Choi, Wonjae; Cohen, Robert E.; Tuteja, Anish; Chhatre, Shreerang S.; Mabry, Joseph M.

    2009-01-01

    A simple “dip-coating” process that imbues oleophobicity to various surfaces that inherently possess re-entrant texture, such as commercially available fabrics, is reported. These dip-coated fabric surfaces exhibit reversible, deformation-dependent, tunable wettability, including the capacity to switch their surface wetting properties (between super-repellent and super-wetting) against a wide range of polar and nonpolar liquids.

  19. CO2 breakthrough pressure and permeability for unsaturated low-permeability sandstone of the Ordos Basin

    Science.gov (United States)

    Zhao, Yan; Yu, Qingchun

    2017-07-01

    With rising threats from greenhouse gases, capture and injection of CO2 into suitable underground formations is being considered as a method to reduce anthropogenic emissions of CO2 to the atmosphere. As the injected CO2 will remain in storage for hundreds of years, the safety of CO2 geologic sequestration is a major concern. The low-permeability sandstone of the Ordos Basin in China is regarded as both caprock and reservoir rock, so understanding the breakthrough pressure and permeability of the rock is necessary. Because part of the pore volume experiences a non-wetting phase during the CO2 injection and migration process, the rock may be in an unsaturated condition. And if accidental leakage occurs, CO2 will migrate up into the unsaturated zone. In this study, breakthrough experiments were performed at various degrees of water saturation with five core samples of low-permeability sandstone obtained from the Ordos Basin. The experiments were conducted at 40 °C and pressures of >8 MPa to simulate the geological conditions for CO2 sequestration. The results indicate that the degree of water saturation and the pore structure are the main factors affecting the rock breakthrough pressure and permeability, since the influence of calcite dissolution and clay mineral swelling during the saturation process is excluded. Increasing the average pore radius or most probable pore radius leads to a reduction in the breakthrough pressure and an increase by several orders of magnitude in scCO2 effective permeability. In addition, the breakthrough pressure rises and the scCO2 effective permeability decreases when the water saturation increases. However, when the average pore radius is greater than 0.151 μm, the degree of water saturation will has a little effect on the breakthrough pressure. On this foundation, if the most probable pore radius of the core sample reaches 1.760 μm, the breakthrough pressure will not be impacted by the increasing water saturation. We establish

  20. Air Consumption Analysis of Air-Jet Weaving

    Directory of Open Access Journals (Sweden)

    RAJ KUMAR KHIANI

    2016-07-01

    Full Text Available In Textile industry, production is mostly key concern for Industry owner. This always has attracted researchers and machines manufacturers to make new developments in process and machines. Air-jet is one of the leading and successful highest productive weaving machines. However, it is now well established that due to add of charges of compressed air, manufacturing cost of air-jet weaving machine is higher as compared with rapier and projectile weaving machines. This is why countries having energy issues do not prefer air-jet weaving machines comparing projectile weaving machines. In this regard, several researchers and machine manufacturers have continuously been working to improve the efficiency of air-jet weft insertion. However, industry practice is as important as design made by researchers. The aim of this research is to investigate the air consumption of air-jet weaving on industrial scale practice. In this study, five weaving machine of same manufacturer and model were selected. It was observed that despite of manufacturing same quality of fabric, air consumption was varying almost in all weaving machines. Conventionally, mill workers adopt hit and trial practice in weaving industry including airpressure setting which leads to variation of nozzle pressure. Main reason of disparity of air consumption in air-jet weaving machines may be variation of distance from compressor to weaving machines, number of joints, un-necessary valve opening and pipes leakages cause an increase of compressed air consumption.

  1. Comparison of Dentin Permeability After Tooth Cavity Preparation with Diamond Bur and Er:YAG Laser

    Directory of Open Access Journals (Sweden)

    Masoumeh Hasani Tabatabaei

    2016-05-01

    Full Text Available Objectives: The aim of this study was to compare the permeability of dentin after using diamond bur and Er:YAG laser.Materials and Methods: Seventy-two recently extracted, intact, and restoration-free human permanent molars were used in this study. The samples were randomly divided into three groups of 24 each and class I cavities were prepared as follows. Group 1: High speed diamond bur with air and water spray. Group 2: Er:YAG laser. Group 3: Er:YAG laser followed by additional sub-ablative laser treatment. Each group consisted of two subgroups with different cavity depths of 2mm and 4mm.  The entire cavity floor was in dentin. Two samples from each subgroup were observed under scanning electron microscope (SEM. The external surfaces of other samples were covered with nail varnish (except the prepared cavity and immersed in 0.5% methylene blue solution for 48 hours.  After irrigation of samples with water, they were sectioned in bucco-lingual direction. Then, the samples were evaluated under a stereomicroscope at ×160 magnification. The data were analyzed using two-way ANOVA and Tukey’s HSD test.Results: Two-way ANOVA showed significant difference in permeability between groups 2 and 3 (laser groups with and without further treatment and group 1 (bur group. The highest permeability was seen in the group 1. There was no significant difference in dentin permeability between groups 2 and 3 and no significant difference was observed between different depths (2mm and 4mm.Conclusion: Cavities prepared by laser have less dentin permeability than cavities prepared by diamond bur.

  2. Engineered Trehalose Permeable to Mammalian Cells.

    Directory of Open Access Journals (Sweden)

    Alireza Abazari

    Full Text Available Trehalose is a naturally occurring disaccharide which is associated with extraordinary stress-tolerance capacity in certain species of unicellular and multicellular organisms. In mammalian cells, presence of intra- and extracellular trehalose has been shown to confer improved tolerance against freezing and desiccation. Since mammalian cells do not synthesize nor import trehalose, the development of novel methods for efficient intracellular delivery of trehalose has been an ongoing investigation. Herein, we studied the membrane permeability of engineered lipophilic derivatives of trehalose. Trehalose conjugated with 6 acetyl groups (trehalose hexaacetate or 6-O-Ac-Tre demonstrated superior permeability in rat hepatocytes compared with regular trehalose, trehalose diacetate (2-O-Ac-Tre and trehalose tetraacetate (4-O-Ac-Tre. Once in the cell, intracellular esterases hydrolyzed the 6-O-Ac-Tre molecules, releasing free trehalose into the cytoplasm. The total concentration of intracellular trehalose (plus acetylated variants reached as high as 10 fold the extracellular concentration of 6-O-Ac-Tre, attaining concentrations suitable for applications in biopreservation. To describe this accumulation phenomenon, a diffusion-reaction model was proposed and the permeability and reaction kinetics of 6-O-Ac-Tre were determined by fitting to experimental data. Further studies suggested that the impact of the loading and the presence of intracellular trehalose on cellular viability and function were negligible. Engineering of trehalose chemical structure rather than manipulating the cell, is an innocuous, cell-friendly method for trehalose delivery, with demonstrated potential for trehalose loading in different types of cells and cell lines, and can facilitate the wide-spread application of trehalose as an intracellular protective agent in biopreservation studies.

  3. [Corneal permeability of topically applied pirenzepine solution].

    Science.gov (United States)

    Wang, Kai-di; Zhang, Jin-song; Yan, Pan-shi

    2006-06-01

    To study the corneal permeability of three different pirenzepine eye-drop solutions and provide reference for further clinical use. Sixty-three New Zealand white rabbits were divided into three groups. Each group of rabbits received 2% pirenzepine (pirenzepine group), 2% pirenzepine with 0.1% hyaluronic acid (hyaluronic acid group), or 2% pirenzepine with 0.1% azone (azone group). One drop eye-drops was applied to conjunctive sac every 5 min for six times. Aqueous samples were obtained from each group at 0.5, 1.0, 2.0, 4.0, 8.0, 12.0, 24.0 h after the last drop, respectively. Concentration of pirenzepine in these samples was determined by the HPLC (high pressure liquid chromatography). Stimulation symptom of rabbit eyes was also observed. The concentrations of pirenzepine in aqueous humor were (0.40 +/- 0.06) microg/ml at 0.5 h, (0.53 +/- 0.03) microg/ml at 1.0 h, (1.52 +/- 0.33) microg/ml at 2.0 h and (0.15 +/- 0.02) microg/ml at 4.0 h in pirenzepine group. Aqueous humor concentration of pirenzepine in both 2% pirenzepine with 0.1% azone and 2% pirenzepine with 0.1% hyaluronic acid were significantly higher than that of single pirenzepine application, and their bioavailability in the groups with combinations of pirenzepine with 0.1% azone or 0.1% hyaluronic acid were 23.0 times and 3.4 times higher than that of single pirenzepine usage. No obvious irritate symptom was found in rabbit of all three groups after eye-drop applying. The combination application of pirenzepine with azone or hyaluronic acid has higher corneal permeability compared with pirenzepine alone. This result indicates that azone and hyaluronic acid could be used in pirenzepine eye-drop solution to increase corneal permeability.

  4. Effective Permeability Change in Wellbore Cement with Carbon Dioxide Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Um, Wooyong; Jung, Hun Bok; Martin, Paul F.; McGrail, B. Peter

    2011-11-01

    -sized calcite on the outside surface of cement, which resulted in the decrease in BJH pore volume and BET surface area. Cement carbonation and pore structure change are significantly dependent on pressure and temperature conditions as well as the phase of CO{sub 2}, which controls the balance between precipitation and dissolution in cement matrix. Geochemical modeling result suggests that ratio of solid (cement)-to-solution (carbonated water) has a significant effect on cement carbonation, thus the cement-CO{sub 2} reaction experiment needs to be conducted under realistic conditions representing the in-situ wellbore environment of carbon sequestration field site. Total porosity and air permeability for a duplicate cement column with water-to-cement ratio of 0.38 measured after oven-drying by Core Laboratories using Boyle's Law technique and steady-state method were 31% and 0.576 mD. A novel method to measure the effective liquid permeability of a cement column using X-ray micro-tomography images after injection of pressurized KI (potassium iodide) is under development by PNNL. Preliminary results indicate the permeability of a cement column with water-to-cement ratio of 0.38 is 4-8 mD. PNNL will apply the method to understand the effective permeability change of Portland cement by CO{sub 2}(g) reaction under a variety of pressure and temperature conditions to develop a more reliable well-bore leakage risk model.

  5. The influence of low-permeability cap on capillary pressure during pumping in unconfined aquifer

    Institute of Scientific and Technical Information of China (English)

    黄辉; 钱家忠; 匡星星; 陈冰宇; 马雷; 吴亚楠

    2013-01-01

    The pumping test in an unconfined aquifer with and without a low-permeability soil was studied experimentally to reveal the influence of the negative air pressure (NP) caused by the upper layer on the water content(w), the water pressure(Pw), as well as on the capillary pressure(Pc). The study demonstrates that the NP generated in the vadose zone during pumping in the capper aquifer has a significant influence onw,wP andPc. ThecP obtained from the capped aquifer is smaller than that without the upper layer. After the NP reaches a peak, the influence of the NP onPc is gradually declined as the air inflows through the upper layer which makes the NP gradually return to zero. When the air pressure returns to the atmospheric pressure,Pc in the vadose zone is only correlated withPw, the same as the case with no upper layer.

  6. PERMEABILITY OF SALTSTONE MEASUREMENT BY BEAM BENDING

    Energy Technology Data Exchange (ETDEWEB)

    Harbour, J; Tommy Edwards, T; Vickie Williams, V

    2008-01-30

    One of the goals of the Saltstone variability study is to identify (and, quantify the impact of) the operational and compositional variables that control or influence the important processing and performance properties of Saltstone mixes. A performance property for Saltstone mixes that is important but not routinely measured is the liquid permeability or saturated hydraulic conductivity of the cured Saltstone mix. The value for the saturated hydraulic conductivity is an input into the Performance Assessment for the SRS Z-Area vaults. Therefore, it is important to have a method available that allows for an accurate and reproducible measurement of permeability quickly and inexpensively. One such method that could potentially meet these requirements for the measurement of saturated hydraulic conductivity is the technique of beam bending, developed by Professor George Scherer at Princeton University. In order to determine the feasibility of this technique for Saltstone mixes, a summer student, David Feliciano, was hired to work at Princeton under the direction of George Scherer. This report details the results of this study which demonstrated the feasibility and applicability of the beam bending method to measurement of permeability of Saltstone samples. This research effort used samples made at Princeton from a Modular Caustic side solvent extraction Unit based simulant (MCU) and premix at a water to premix ratio of 0.60. The saturated hydraulic conductivities for these mixes were measured by the beam bending technique and the values determined were of the order of 1.4 to 3.4 x 10{sup -9} cm/sec. These values of hydraulic conductivity are consistent with independently measured values of this property on similar MCU based mixes by Dixon and Phifer. These values are also consistent with the hydraulic conductivity of a generic Saltstone mix measured by Langton in 1985. The high water to premix ratio used for Saltstone along with the relatively low degree of hydration for

  7. Altered permeability barrier structure in cholesteatoma matrix

    DEFF Research Database (Denmark)

    Svane-Knudsen, Viggo; Halkier-Sørensen, Lars; Rasmussen, Gurli

    2002-01-01

    The stratum corneum of the cholesteatoma epithelium comprises the greater part of the cholesteatoma matrix. The permeability barrier that militates against diffusion and penetration of infectious and toxic agents into and through the epithelium is situated here. The multiple long sheets of lamellar...... lipid structures filling the intercellular spaces mainly control the barrier function. The barrier in cholesteatoma epithelium is several times thicker than in unaffected skin but presents distinctive features of a defective barrier as seen in other scaling skin diseases. The intercellular spaces appear...

  8. Gas permeability measurements for film envelope materials

    Energy Technology Data Exchange (ETDEWEB)

    Ludtka, Gerard M. (Oak Ridge, TN); Kollie, Thomas G. (Oak Ridge, TN); Watkin, David C. (Clinton, TN); Walton, David G. (Knoxville, TN)

    1998-01-01

    Method and apparatus for measuring the permeability of polymer film materials such as used in super-insulation powder-filled evacuated panels (PEPs) reduce the time required for testing from several years to weeks or months. The method involves substitution of a solid non-outgassing body having a free volume of between 0% and 25% of its total volume for the usual powder in the PEP to control the free volume of the "body-filled panel". Pressure versus time data for the test piece permit extrapolation to obtain long term performance of the candidate materials.

  9. Gas permeability measurements for film envelope materials

    Energy Technology Data Exchange (ETDEWEB)

    Ludtka, G.M.; Kollie, T.G.; Watkin, D.C.; Walton, D.G.

    1998-05-12

    Method and apparatus for measuring the permeability of polymer film materials such as used in super-insulation powder-filled evacuated panels (PEPs) reduce the time required for testing from several years to weeks or months. The method involves substitution of a solid non-outgassing body having a free volume of between 0% and 25% of its total volume for the usual powder in the PEP to control the free volume of the ``body-filled panel.`` Pressure versus time data for the test piece permit extrapolation to obtain long term performance of the candidate materials. 4 figs.

  10. On the dynamic viscous permeability tensor symmetry.

    Science.gov (United States)

    Perrot, Camille; Chevillotte, Fabien; Panneton, Raymond; Allard, Jean-François; Lafarge, Denis

    2008-10-01

    Based on a direct generalization of a proof given by Torquato for symmetry property in static regime, this express letter clarifies the reasons why the dynamic permeability tensor is symmetric for spatially periodic structures having symmetrical axes which do not coincide with orthogonal pairs being perpendicular to the axis of three-, four-, and sixfold symmetry. This somewhat nonintuitive property is illustrated by providing detailed numerical examples for a hexagonal lattice of solid cylinders in the asymptotic and frequency dependent regimes. It may be practically useful for numerical implementation validation and/or convergence assessment.

  11. Gas-Flow Tailoring Fabrication of Graphene-like Co-Nx-C Nanosheet Supported Sub-10 nm PtCo Nanoalloys as Synergistic Catalyst for Air-Cathode Microbial Fuel Cells.

    Science.gov (United States)

    Cao, Chun; Wei, Liling; Zhai, Qiran; Ci, Jiliang; Li, Weiwei; Wang, Gang; Shen, Jianquan

    2017-07-12

    In this work, we presented a novel, facile, and template-free strategy for fabricating graphene-like N-doped carbon as oxygen reduction catalyst in sustainable microbial fuel cells (MFCs) by using an ion-inducing and spontaneous gas-flow tailoring effect from a unique nitrogen-rich polymer gel precursor which has not been reported in materials science. Remarkably, by introduction of trace platinum- and cobalt- precursor in polymer gel, highly dispersed sub-10 nm PtCo nanoalloys can be in situ grown and anchored on graphene-like carbon. The as-prepared catalysts were investigated by a series of physical characterizations, electrochemical measurements, and microbial fuel cell tests. Interestingly, even with a low Pt content (5.13 wt %), the most active Co/N codoped carbon supported PtCo nanoalloys (Co-N-C/Pt) exhibited dramatically improved catalytic activity toward oxygen reduction reaction coupled with superior output power density (1008 ± 43 mW m(-2)) in MFCs, which was 29.40% higher than the state of the art Pt/C (20 wt %). Notability, the distinct catalytic activity of Co-N-C/Pt was attributed to the highly efficient synergistic catalytic effect of Co-Nx-C and PtCo nanoalloys. Therefore, Co-N-C/Pt should be a promising oxygen reduction catalyst for application in MFCs. Further, the novel strategy for graphene-like carbon also can be widely used in many other energy conversion and storage devices.

  12. The development of polymer membranes and modules for air separation

    Science.gov (United States)

    Vinogradov, N. E.; Kagramanov, G. G.

    2016-09-01

    Technology of hollow fiber membrane and modules for air separation was developed. Hollow fibers from the polyphenylene oxide (PPO) having a diameter of 500 μm were obtained. The permeability of the fibers by oxygen was up to 250 Ba, while the separation factor by O2/N2 was 4.3. The membrane module has been made by using these fibers and tested for permeability of individual gases.

  13. Fabrication and characterization of non-linear parabolic microporous membranes.

    Science.gov (United States)

    Rajasekaran, Pradeep Ramiah; Sharifi, Payam; Wolff, Justin; Kohli, Punit

    2015-01-01

    Large scale fabrication of non-linear microporous membranes is of technological importance in many applications ranging from separation to microfluidics. However, their fabrication using traditional techniques is limited in scope. We report on fabrication and characterization of non-linear parabolic micropores (PMS) in polymer membranes by utilizing flow properties of fluids. The shape of the fabricated PMS corroborated well with simplified Navier-Stokes equation describing parabolic relationship of the form L - t(1/2). Here, L is a measure of the diameter of the fabricated micropores during flow time (t). The surface of PMS is smooth due to fluid surface tension at fluid-air interface. We demonstrate fabrication of PMS using curable polydimethylsiloxane (PDMS). The parabolic shape of micropores was a result of interplay between horizontal and vertical fluid movements due to capillary, viscoelastic, and gravitational forces. We also demonstrate fabrication of asymmetric "off-centered PMS" and an array of PMS membranes using this simple fabrication technique. PMS containing membranes with nanoscale dimensions are also possible by controlling the experimental conditions. The present method provides a simple, easy to adopt, and energy efficient way for fabricating non-linear parabolic shape pores at microscale. The prepared parabolic membranes may find applications in many areas including separation, parabolic optics, micro-nozzles / -valves / -pumps, and microfluidic and microelectronic delivery systems.

  14. Estimation of permeability and permeability anisotropy in horizontal wells through numerical simulation of mud filtrate invasion

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Nelson [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Exploracao e Producao; Altman, Raphael; Rasmus, John; Oliveira, Jansen [Schlumberger Servicos de Petroleo Ltda., Rio de Janeiro, RJ (Brazil)

    2008-07-01

    This paper describes how permeability and permeability anisotropy is estimated in horizontal wells using LWD (logging-while-drilling) laterolog resistivity data. Laterolog-while-drilling resistivity passes of while-drilling and timelapse (while reaming) were used to capture the invasion process. Radial positions of water based mud invasion fronts were calculated from while-drilling and reaming resistivity data. The invasion process was then recreated by constructing forward models with a fully implicit, near-wellbore numerical simulation such that the invasion front at a given time was consistent with the position of the front predicted by resistivity inversions. The radial position of the invasion front was shown to be sensitive to formation permeability. The while-drilling environment provides a fertile scenario to investigate reservoir dynamic properties because mud cake integrity and growth is not fully developed which means that the position of the invasion front at a particular point in time is more sensitive to formation permeability. The estimation of dynamic formation properties in horizontal wells is of particular value in marginal fields and deep-water offshore developments where running wireline and obtaining core is not always feasible, and where the accuracy of reservoir models can reduce the risk in field development decisions. (author)

  15. Micro fabrication of biodegradable polymer drug delivery devices

    DEFF Research Database (Denmark)

    Nagstrup, Johan

    The pharmaceutical industry is presently facing several obstacles in developing oral drug delivery systems. This is primarily due to the nature of the discovered drug candidates. The discovered drugs often have poor solubility and low permeability across the gastro intestinal epithelium. Furtherm...... the developed devices. Additionally, it has been shown that it is possible to control the release of drug by adding polymeric coatings........ Furthermore, they are often degraded before they can be absorbed. The result is low bioavailability of the drugs. To overcome these challenges, better drug delivery systems need to be developed. Recently, micro systems have emerged as promising candidates to solve the challenges of poor solubility, low...... permeability and degradation. These systems are for the majority based on traditional materials used in micro technology, such as SU-8, silicon, poly(methyl methacrylate). The next step in developing these new drug delivery systems is to replace classical micro fabrication materials with biodegradable polymers...

  16. Modeling of microvascular permeability changes after electroporation.

    Directory of Open Access Journals (Sweden)

    Selma Corovic

    Full Text Available Vascular endothelium selectively controls the transport of plasma contents across the blood vessel wall. The principal objective of our preliminary study was to quantify the electroporation-induced increase in permeability of blood vessel wall for macromolecules, which do not normally extravasate from blood into skin interstitium in homeostatic conditions. Our study combines mathematical modeling (by employing pharmacokinetic and finite element modeling approach with in vivo measurements (by intravital fluorescence microscopy. Extravasation of fluorescently labeled dextran molecules of two different sizes (70 kDa and 2000 kDa following the application of electroporation pulses was investigated in order to simulate extravasation of therapeutic macromolecules with molecular weights comparable to molecular weight of particles such as antibodies and plasmid DNA. The increase in blood vessel permeability due to electroporation and corresponding transvascular transport was quantified by calculating the apparent diffusion coefficients for skin microvessel wall (D [μm2/s] for both molecular sizes. The calculated apparent diffusion coefficients were D = 0.0086 μm2/s and D = 0.0045 μm2/s for 70 kDa and 2000 kDa dextran molecules, respectively. The results of our preliminary study have important implications in development of realistic mathematical models for prediction of extravasation and delivery of large therapeutic molecules to target tissues by means of electroporation.

  17. Modeling the pharmacodynamics of passive membrane permeability

    Science.gov (United States)

    Swift, Robert V.; Amaro, Rommie E.

    2011-11-01

    Small molecule permeability through cellular membranes is critical to a better understanding of pharmacodynamics and the drug discovery endeavor. Such permeability may be estimated as a function of the free energy change of barrier crossing by invoking the barrier domain model, which posits that permeation is limited by passage through a single "barrier domain" and assumes diffusivity differences among compounds of similar structure are negligible. Inspired by the work of Rezai and co-workers (JACS 128:14073-14080, 2006), we estimate this free energy change as the difference in implicit solvation free energies in chloroform and water, but extend their model to include solute conformational affects. Using a set of eleven structurally diverse FDA approved compounds and a set of thirteen congeneric molecules, we show that the solvation free energies are dominated by the global minima, which allows solute conformational distributions to be effectively neglected. For the set of tested compounds, the best correlation with experiment is obtained when the implicit chloroform global minimum is used to evaluate the solvation free energy difference.

  18. Haemophilia, AIDS and lung epithelial permeability

    Energy Technology Data Exchange (ETDEWEB)

    O' Doherty, M.J.; Page, C.J.; Harrington, C.; Nunan, T.; Savidge, G. (Haemophilia Centre and Coagulation Research Unit, Department of Nuclear Medicine, Rayne Institute, St. Thomas' Hospital, London (United Kingdom))

    1990-01-01

    Lung {sup 99m}Tc DTPA transfer was measured in HIV antibodypositive haemophiliacs (11 smokers, 26 nonsmokers, 5 patients with Pneumocystis carinii pneumonia (PCP)). Lung {sup 99m}Tc DTPA transfer as a marker of lung epithelial permeability was measured as the half time of transfer (from airspace into blood). This half time was faster in smokers compred to nonsmokers and the transfer curve was monoexponential. In nonsmokers no difference was observed between asymptomatic HIV-positive haemophiliacs and normal subjects, with the exception of the lung bases. At the lung basis in HIV-positive haemophiliac nonsmokers the transfer was faster than in normal individuals, implying increased alveolar permeability. Pneumocystis carinii pneumonia resulted in a rapid transfer of {sup 99m}Tc DTPA (mean T50 of 2 minutes) and the transfer curve was biphasic, confirming previous observations in homosexual HIV antibody-positive patients with PCP. These changes returned to a monoexponential profile by 6 weeks following successful treatment. The DTPA lung transfer study may enable clinicians to instigate therapy for PCP without the need for initial bronchoscopy and provide a noninvasive method for the reassessment of patients should further respiratory signs or symptoms develop. This method is considered to be highly cost-effective in that it obviates the use of factor VIII concentrates required to cover bronchoscopic procedures and, with its early application and ease of use as a follow-up investigation, permits the evaluation of patients on an outpatient basis, thus reducing hospital costs. (au).

  19. Modeling of microvascular permeability changes after electroporation.

    Science.gov (United States)

    Corovic, Selma; Markelc, Bostjan; Dolinar, Mitja; Cemazar, Maja; Jarm, Tomaz

    2015-01-01

    Vascular endothelium selectively controls the transport of plasma contents across the blood vessel wall. The principal objective of our preliminary study was to quantify the electroporation-induced increase in permeability of blood vessel wall for macromolecules, which do not normally extravasate from blood into skin interstitium in homeostatic conditions. Our study combines mathematical modeling (by employing pharmacokinetic and finite element modeling approach) with in vivo measurements (by intravital fluorescence microscopy). Extravasation of fluorescently labeled dextran molecules of two different sizes (70 kDa and 2000 kDa) following the application of electroporation pulses was investigated in order to simulate extravasation of therapeutic macromolecules with molecular weights comparable to molecular weight of particles such as antibodies and plasmid DNA. The increase in blood vessel permeability due to electroporation and corresponding transvascular transport was quantified by calculating the apparent diffusion coefficients for skin microvessel wall (D [μm2/s]) for both molecular sizes. The calculated apparent diffusion coefficients were D = 0.0086 μm2/s and D = 0.0045 μm2/s for 70 kDa and 2000 kDa dextran molecules, respectively. The results of our preliminary study have important implications in development of realistic mathematical models for prediction of extravasation and delivery of large therapeutic molecules to target tissues by means of electroporation.

  20. Enhanced CO2 permeability of membranes by incorporating polyzwitterion@CNT composite particles into polyimide matrix.

    Science.gov (United States)

    Liu, Ye; Peng, Dongdong; He, Guangwei; Wang, Shaofei; Li, Yifan; Wu, Hong; Jiang, Zhongyi

    2014-08-13

    In this study, polyzwitterion is introduced into a CO2 separation membrane. Composite particles of polyzwitterion coated carbon nanotubes (SBMA@CNT) are prepared via a precipitation polymerization method. Hybrid membranes are fabricated by incorporating SBMA@CNT in polyimide matrix and utilized for CO2 separation. The prepared composite particles and hybrid membranes are characterized by transmission electron microscopy (TEM) with element mapping, field emission scanning electron microscopy (FESEM), Fourier transform infrared (FTIR) spectra, differential scanning calorimetry (DSC) and an electronic tensile machine. Water uptake and water state of membranes are measured to probe the relationship among water uptake, water state and CO2 transport behavior. Hybrid membranes show significantly enhanced CO2 permeability compared to an unfilled polyimide membrane at a humidified state. A hybrid membrane with 5 wt % SBMA@CNT exhibits the maximum CO2 permeability of 103 Barrer with a CO2/CH4 selectivity of 36. The increase of CO2 permeability is attributed to the incorporation of the SBMA@CNT composite particles. First, SBMA@CNT form interconnected channels for CO2 transport due to the facilitated transport effect of the quaternary ammonium in repeat unit of pSBMA. Second, SBMA@CNT improve water uptake and adjust water state of membrane, which further increases CO2 permeability. Meanwhile, the variation of CO2/CH4 selectivity is dependent on the bound water portion in the membrane. A gas permeation test at a dry state and a pressure test are conducted to further probe the membrane separation performance.

  1. Fabrication of PDMS architecture

    Science.gov (United States)

    Adam, Tijjani; Hashim, U.

    2017-03-01

    The study report novel, yet simple and flexible fabrication method for micro channel patterning PDMS thin mold on glass surfaces, the method allows microstructures with critical dimensions to be formed using PDMS. Micro channel production is a two-step process. First, soft photolithography methods are implemented to fabricate a reusable mold. The mold is then used to create the micro channel, which consists of SU8, PDMS and glass. The micro channel design was performed using AutoCAD and the fabrication begins by creating a replicable mold. The mold is created on a glass slide. by spin-coating speed between 500 to 1250rpm with an acceleration of 100 rpm/s for 100 and 15 second ramp up and down speed respectively. Channel flow rate based on concentration were measured by analyzing the recorded flow profiles which was collected from the high powered microscope at. 80µ, 70µm, 50µm for inlet channel 1, 2, 3 respectively the channel flow were compared for flow efficiency at different concentrations and Re. Thus, the simplicity of device structure and fabrication makes it feasible to miniaturize it for the development of point-of-care kits, facilitating its use in both clinical and non-clinical environments. With its simple geometric structure and potential for mass commercial fabrication, the device can be developed to become a portable photo detection sensor that can be use for both environmental and diagnostic application.

  2. Therapeutic benefits of enhancing permeability barrier for atopic eczema

    Directory of Open Access Journals (Sweden)

    George Man

    2015-06-01

    Full Text Available The regulatory role of epidermal permeability barrier function in cutaneous inflammation has been well appreciated. While barrier disruption induces cutaneous inflammation, improvement of permeability barrier function alleviates inflammation. Studies have demonstrated that improvement of epidermal permeability barrier function not only prevents the development of atopic eczema, but also delays the relapse of these diseases. Moreover, enhancing the epidermal permeability barrier also alleviates atopic eczema. Furthermore, co-applications of barrier enhancing products with glucocorticoids can increase the therapeutic efficacy and reduce the adverse effects of glucocorticoids in the treatment of atopic eczema. Therefore, utilization of permeability barrier enhancing products alone or in combination with glucocorticoids could be a valuable approach in the treatment of atopic eczema. In this review, we discuss the benefits of improving the epidermal permeability barrier in the management of atopic eczema.

  3. Herbal medicines that benefit epidermal permeability barrier function

    Directory of Open Access Journals (Sweden)

    Lizhi Hu

    2015-06-01

    Full Text Available Epidermal permeability barrier function plays a critical role in regulating cutaneous functions. Hence, researchers have been searching for effective and affordable regimens to enhance epidermal permeability barrier function. In addition to topical stratum corneum lipids, peroxisome proliferator-activated receptor, and liver X receptor ligands, herbal medicines have been proven to benefit epidermal permeability barrier function in both normal and diseased skin, including atopic dermatitis, glucocorticoid-induced skin damage, and UVB-damaged skin. The potential mechanisms by which herbal medicines improve the permeability barrier include stimulation of epidermal differentiation, lipid production, antimicrobial peptide expression, and antioxidation. Therefore, utilization of herbal medicines could be a valuable alternative approach to enhance epidermal permeability barrier function in order to prevent and/or treat skin disorders associated with permeability barrier abnormalities.

  4. Calculation of large scale relative permeabilities from stochastic properties of the permeability field and fluid properties

    Energy Technology Data Exchange (ETDEWEB)

    Lenormand, R.; Thiele, M.R. [Institut Francais du Petrole, Rueil Malmaison (France)

    1997-08-01

    The paper describes the method and presents preliminary results for the calculation of homogenized relative permeabilities using stochastic properties of the permeability field. In heterogeneous media, the spreading of an injected fluid is mainly sue to the permeability heterogeneity and viscosity fingering. At large scale, when the heterogeneous medium is replaced by a homogeneous one, we need to introduce a homogenized (or pseudo) relative permeability to obtain the same spreading. Generally, is derived by using fine-grid numerical simulations (Kyte and Berry). However, this operation is time consuming and cannot be performed for all the meshes of the reservoir. We propose an alternate method which uses the information given by the stochastic properties of the field without any numerical simulation. The method is based on recent developments on homogenized transport equations (the {open_quotes}MHD{close_quotes} equation, Lenormand SPE 30797). The MHD equation accounts for the three basic mechanisms of spreading of the injected fluid: (1) Dispersive spreading due to small scale randomness, characterized by a macrodispersion coefficient D. (2) Convective spreading due to large scale heterogeneities (layers) characterized by a heterogeneity factor H. (3) Viscous fingering characterized by an apparent viscosity ration M. In the paper, we first derive the parameters D and H as functions of variance and correlation length of the permeability field. The results are shown to be in good agreement with fine-grid simulations. The are then derived a function of D, H and M. The main result is that this approach lead to a time dependent . Finally, the calculated are compared to the values derived by history matching using fine-grid numerical simulations.

  5. Temperature influences on water permeability and chlorpyrifos uptake in aquatic insects with differing respiratory strategies

    Science.gov (United States)

    Buchwalter, D.B.; Jenkins, J.J.; Curtis, L.R.

    2003-01-01

    Aquatic insects have evolved diverse respiratory strategies that range from breathing atmospheric air to breathing dissolved oxygen. These strategies result in vast morphological differences among taxa in terms of exchange epithelial surface areas that are in direct contact with the surrounding water that, in turn, affect physiological processes. This paper examines the effects of acute temperature shifts on water permeability and chlorpyrifos uptake in aquatic insects with different respiratory strategies. While considerable differences existed in water permeability among the species tested, acute temperature shifts raised water influx rates similarly in air-breathing and gill-bearing taxa. This contrasts significantly with temperature-shift effects on chlorpyrifos uptake. Temperature shifts of 4.5??C increased 14C-chlorpyrifos accumulation rates in the gill-bearing mayfly Cinygma sp. and in the air-breathing hemipteran Sigara washingtonensis. However, the temperature-induced increase in 14C-chlorpyrifos uptake after 8 h of exposure was 2.75-fold higher in Cinygma than in Sigara. Uptake of 14C-chlorpyrifos was uniformly higher in Cinygma than in Sigara in all experiments. These findings suggest that organisms with relatively large exchange epithelial surface areas are potentially more vulnerable to both osmoregulatory distress as well as contaminant accumulation. Temperature increases appear more likely to impact organisms that have relatively large exchange epithelial surface areas, both as an individual stressor and in combination with additional stressors such as contaminants.

  6. Modelling of Longwall Mining-Induced Strata Permeability Change

    Science.gov (United States)

    Adhikary, D. P.; Guo, H.

    2015-01-01

    The field measurement of permeability within the strata affected by mining is a challenging and expensive task, thus such tests may not be carried out in large numbers to cover all the overburden strata and coal seams being affected by mining. However, numerical modelling in conjunction with a limited number of targeted field measurements can be used efficiently in assessing the impact of mining on a regional scale. This paper presents the results of underground packer testing undertaken at a mine site in New South Wales in Australia and numerical simulations conducted to assess the mining-induced strata permeability change. The underground packer test results indicated that the drivage of main headings (roadways) had induced a significant change in permeability into the solid coal barrier. Permeability increased by more than 50 times at a distance of 11.2-11.5 m from the roadway rib into the solid coal barrier. The tests conducted in the roof strata above the longwall goaf indicated more than 1,000-fold increase in permeability. The measured permeability values varied widely and strangely on a number of occasions; for example the test conducted from the main headings at the 8.2-8.5 m test section in the solid coal barrier showed a decline in permeability value as compared to that at the 11.2-11.5 m section contrary to the expectations. It is envisaged that a number of factors during the tests might have had affected the measured values of permeability: (a) swelling and smearing of the borehole, possibly lowering the permeability values; (b) packer bypass by larger fractures; (c) test section lying in small but intact (without fractures) rock segment, possibly resulting in lower permeability values; and (d) test section lying right at the extensive fractures, possibly measuring higher permeability values. Once the anomalous measurement data were discarded, the numerical model results could be seen to match the remaining field permeability measurement data

  7. Understanding core conductor fabrics

    Energy Technology Data Exchange (ETDEWEB)

    Swenson, D E, E-mail: deswenson@affinity-esd.com [Affinity Static Control Consulting, LLC 2609 Quanah Drive, Round Rock, Texas, 78681 (United States)

    2011-06-23

    ESD Association standard test method ANSI/ESD STM2.1 - Garments (STM2.1), provides electrical resistance test procedures that are applicable for materials and garments that have surface conductive or surface dissipative properties. As has been reported in other papers over the past several years{sup 1} fabrics are now used in many industries for electrostatic control purposes that do not have surface conductive properties and therefore cannot be evaluated using the procedures in STM2.1{sup 2}. A study was conducted to compare surface conductive fabrics with samples of core conductor fibre based fabrics in order to determine differences and similarities with regards to various electrostatic properties. This work will be used to establish a new work item proposal within WG-2, Garments, in the ESD Association Standards Committee in the USA.

  8. Neural Approach for Calculating Permeability of Porous Medium

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ji-Cheng; LIU Li; SONG Kao-Ping

    2006-01-01

    @@ Permeability is one of the most important properties of porous media. It is considerably difficult to calculate reservoir permeability precisely by using single well-logging response and simple formula because reservoir is of serious heterogeneity, and well-logging response curves are badly affected by many complicated factors underground. We propose a neural network method to calculate permeability of porous media. By improving the algorithm of the back-propagation neural network, convergence speed is enhanced and better results can be achieved. A four-layer back-propagation network is constructed to effectively calculate permeability from well log data.

  9. Characteristics of permeability in carbonate areas of Korea

    Science.gov (United States)

    Park, Y.; Lee, J.; Lim, H.; Keehm, Y.

    2010-12-01

    Permeability (hydraulic conductivity) in carbonate areas is affected by various factors such as fracture, pore and degree of weathering and diagenesis. Also, caves developed in carbonate area are main factors. This study was performed to understand factors controlling the permeability in carbonate areas in Korea. In order to conduct this study, the permeability and well logging data (n=30) were collected from many literatures and rock samples were collected around wells. Vertical profile of the carbonate areas can be classified into soil, weathered carbonate and fresh carbonate zone. They show a different range at each region. Most of the rock samples were hardly weathered. The permeability showed wide ranges (0.009 to 1.1 m/day). The average value of the permeability was 0.159 m/day. However, 80% (n=24) of total data had the permeability valves lower than 0.1 m/day. The permeability values were distinguished according to degree of development of fractures. The permeability showed low values (approximately 0.5 m/day) in highly fractured carbonate. These results mean that fractures are dominant factors controlling the permeability in carbonate areas of Korea than others. This work was supported by Energy Resource R&D program (2009T100200058) under the Ministry of Knowledge Economy, Republic of Korea.

  10. Gut permeability in neonates after a stage 1 Norwood procedure.

    Science.gov (United States)

    Malagon, Ignacio; Onkenhout, Willem; Klok, Margreet; van der Poel, Petrus F H; Bovill, James G; Hazekamp, Mark G

    2005-09-01

    Intestinal mucosal ischemia can occur during and after cardiac surgery. Severe decreases in mucosal perfusion may be a causative factor for postoperative mortality or complications such as necrotizing enterocolitis. Mesenteric perfusion is challenged preoperatively due to an imbalance between the systemic and pulmonary circulations and challenged intraoperatively due to hypothermic circulatory arrest. We have investigated gut permeability in seven patients undergoing stage 1 of the Norwood procedure, applying the dual sugar permeability test with L-rhamnose and lactulose. Seven patients with hypoplastic left heart syndrome: clinical presentation, gut permeability findings, and outcome. A 10-bed mixed pediatric intensive care unit in a university hospital. Seven patients admitted for postoperative care after cardiac surgery. Determination of gut permeability with the dual sugar permeability test using lactulose and rhamnose. Intestinal permeability was measured after induction of anesthesia and 12 and 24 hrs later. : All patients had abnormal lactulose/rhamnose ratios. One patient, who had a lactulose/rhamnose ratio 12 hrs after surgery of 2.3 (46-times normal), developed necrotizing enterocolitis postoperatively and died 3 days after surgery. Gut permeability as assessed by the dual sugar permeability test is abnormal in patients with hypoplastic left heart syndrome before and after surgery. Lactulose/rhamnose ratios 46 times the normal value reflect a highly permeable small intestine. This may be a sign of a low output state and may help to identify patients at risk of developing necrotizing enterocolitis.

  11. Influence of decenylsuccinic Acid on water permeability of plant cells.

    Science.gov (United States)

    Lee, O Y; Stadelmann, E J; Weiser, C J

    1972-11-01

    Decenylsuccinic acid altered permeability to water of epidermal cells of bulb scales of Allium cepa and of the leaf midrib of Rhoeo discolor. Water permeability, as determined by deplasmolysis time measurements, was related to the dose of undissociated decenylsuccinic acid (mm undissociated decenylsuccinic acid x minute). No relationship was found between permeability and total dose of decenylsuccinic acid, or dose of dissociated decenylsuccinic acid, suggesting that the undissociated molecule was the active factor in permeability changes and injury.At doses which did not damage cells (0.0008 to 0.6 [mm of the undissociated molecule x minute]) decenylsuccinic acid decreased water permeability. At higher doses (e.g., 4 to 8 [mm x minute]) injury to cells was common and decenylsuccinic acid increased permeability. Doses above the 10 to 20 (mm x minute) range were generally lethal. The plasmolysis form of uninjured cells was altered and protoplasmic swelling occasionally was observed. The dose-dependent reversal of water permeability changes (decreased to increased permeability) may reflect decenylsuccinic acid-induced changes in membrane structure. Reported effects of decenylsuccinic acid on temperature dependence of permeability and frost resistance were not verified.

  12. Dentin permeability: effects of endodontic procedures on root slabs.

    Science.gov (United States)

    Fogel, H M; Pashley, D H

    1990-09-01

    The permeability of human radicular dentin was measured as a hydraulic conductance before and after treatment with K files and before and after subsequent treatment of the endodontic smear layer with NaOCl, 50% citric acid, or 3% monopotassium-monohydrogen oxalate. Filing reduced dentin permeability 25 to 49%, respectively, depending upon whether outer or inner root dentin was filed. The permeability of these smear layers was unaffected by 5% NaOCl but increased many times after treatment with 50% citric acid for 2 min. Oxalate treatment lowered root dentin permeability to levels below that produced by creation of smear layers due to the production of a crystalline precipitate.

  13. Reduced bleed air extraction for DC-10 cabin air conditioning

    Science.gov (United States)

    Newman, W. H.; Viele, M. R.; Hrach, F. J.

    1980-01-01

    It is noted that a significant fuel savings can be achieved by reducing bleed air used for cabin air conditioning. Air in the cabin can be recirculated to maintain comfortable ventilation rates but the quality of the air tends to decrease due to entrainment of smoke and odors. Attention is given to a development system designed and fabricated under the NASA Engine Component Improvement Program to define the recirculation limit for the DC-10. It is shown that with the system, a wide range of bleed air reductions and recirculation rates is possible. A goal of 0.8% fuel savings has been achieved which results from a 50% reduction in bleed extraction from the engine.

  14. Langmuir and Langmuir-Blodgett films of capsules of haemoglobin at air/water and solid/air interfaces

    Indian Academy of Sciences (India)

    J Maheshkumar; A Dhathathreyan

    2013-03-01

    Organized assemblies of capsules of haemoglobin (Hb), in the size range of 0.1 to 0.3 in Langmuir films have been studied at air/water interface below and above the isoelectric point. Spread films of these organizates suggest that there is no expulsion of individual particles or particle assemblies at the interface and the particles are stable. Dynamic surface tension and the associated dilational and shear visco-elasticity in these films suggest that the capsules are highly elastic. Multilayer films of the capsules using Langmuir-Blodgett technique have been fabricated by sequential deposition on solid surfaces. These films have been characterized by circular dichroism spectroscopy (CD), atomic force microscopy (AFM), quartz crystal microbalance (QCM) and Fourier transform infrared with reflection absorption spectroscopy (FTIR-RAS). No appreciable change in the secondary structural features of Hb is seen from CD studies indicating the stability of the protein in these organized assemblies. Sizes of these capsules change near the isoelectric point and large swollen multiwalled capsules are formed. The elastic films of capsules of Hb provide a useful post preparation approach for modification of the surface roughness, porosity, and permeability of pre-assembled polypeptide microcapsules.

  15. Development of carbon free diffusion layer for activated carbon air cathode of microbial fuel cells.

    Science.gov (United States)

    Yang, Wulin; Kim, Kyoung-Yeol; Logan, Bruce E

    2015-12-01

    The fabrication of activated carbon air cathodes for larger-scale microbial fuel cells requires a diffusion layer (DL) that is highly resistant to water leakage, oxygen permeable, and made using inexpensive materials. A hydrophobic polyvinylidene fluoride (PVDF) membrane synthesized using a simple phase inversion process was examined as a low cost ($0.9/m(2)), carbon-free DL that prevented water leakage at high pressure heads compared to a polytetrafluoroethylene/carbon black DL ($11/m(2)). The power density produced with a PVDF (20%, w/v) DL membrane of 1400±7mW/m(2) was similar to that obtained using a wipe DL [cloth coated with poly(dimethylsiloxane)]. Water head tolerance reached 1.9m (∼19kPa) with no mesh supporter, and 2.1m (∼21kPa, maximum testing pressure) with a mesh supporter, compared to 0.2±0.05m for the wipe DL. The elimination of carbon black from the DL greatly simplified the fabrication procedure and further reduced overall cathode costs.

  16. Compaction and Permeability Reduction of Castlegate Sandstone under Pore Pressure Cycling

    Science.gov (United States)

    Bauer, S. J.

    2014-12-01

    We investigate time-dependent compaction and permeability changes by cycling pore pressure with application to compressed air energy storage (CAES) in a reservoir. Preliminary experiments capture the impacts of hydrostatic stress, pore water pressure, pore pressure cycling, chemical, and time-dependent considerations near a borehole in a CAES reservoir analog. CAES involves creating an air bubble in a reservoir. The high pressure bubble serves as a mechanical battery to store potential energy. When there is excess grid energy, bubble pressure is increased by air compression, and when there is energy needed on the grid, stored air pressure is released through turbines to generate electricity. The analog conditions considered are depth ~1 km, overburden stress ~20 MPa and a pore pressure ~10MPa. Pore pressure is cycled daily or more frequently between ~10 MPa and 6 MPa, consistent with operations of a CAES facility at this depth and may continue for operational lifetime (25 years). The rock can vary from initially fully-to-partially saturated. Pore pressure cycling changes the effective stress.Jacketed, room temperature tap water-saturated samples of Castlegate Sandstone are hydrostatically confined (20 MPa) and subjected to a pore pressure resulting in an effective pressure of ~10 MPa. Pore pressure is cycled between 6 to 10 MPa. Sample displacement measurements yielded determinations of volumetric strain and from water flow measurements permeability was determined. Experiments ran for two to four weeks, with 2 to 3 pore pressure cycles per day. The Castlegate is a fluvial high porosity (>20%) primarily quartz sandstone, loosely calcite cemented, containing a small amount of clay.Pore pressure cycling induces compaction (~.1%) and permeability decreases (~20%). The results imply that time-dependent compactive processes are operative. The load path, of increasing and decreasing pore pressure, may facilitate local loosening and grain readjustments that results in the

  17. Comparison of Dentin Permeability After Tooth Cavity Preparation with Diamond Bur and Er:YAG Laser

    OpenAIRE

    Masoumeh Hasani Tabatabaei; Sara Shirmohammadi; Esmaeil Yasini; Mansoureh Mirzaei; Sakineh Arami; Hamid Kermanshah; Ladan Ranjbar Omrani; Azar Alimi; Nasim Chiniforush; Afrooz Nakhostin; Mahdi Abbasi

    2015-01-01

    Objectives: The aim of this study was to compare the permeability of dentin after using diamond bur and Er:YAG laser.Materials and Methods: Seventy-two recently extracted, intact, and restoration-free human permanent molars were used in this study. The samples were randomly divided into three groups of 24 each and class I cavities were prepared as follows. Group 1: High speed diamond bur with air and water spray. Group 2: Er:YAG laser. Group 3: Er:YAG laser followed by additional sub-ablative...

  18. Application of the antistatic agent P on polyester fabric%抗静电剂P在涤纶织物上的应用

    Institute of Scientific and Technical Information of China (English)

    刘晓云; 钟少锋; 王晓芳

    2012-01-01

    The antistatic properties and application process of self-made finishing agent P on polyester fabric were investigated. The color shade, color fastness and wearabilities of treated fabrics were further discussed. The antistatic properties of polyester fabrics were examined by measuring the peak value of the static voltage, its half life and the contact angle, and the durability of the antistatic property of the fabrics after 20 washing cycles. The effect of finishing agent on the wearabilities of polyester fabrics was further discussed by measuring the bending length, air permeability and breaking strength. The effects of finishing agent on the hue and color fastness of dyed fabric were investigated through measuring the K/S value, color difference, color fastness to rubbing and washing. The results indicate that the finishing agent P shows excellent antistatic properties and washing durability. The optimized conditions were: finishing agent P 5 g/L, two dipping and padding with 70%~75% of pick-up, drying temperature 70 ℃. The polyester fabric retained good handle, but the air permeability and breaking strength decreased slightly, which would not affect the wearability. The effect of finishing agent on the color shade and color fastness was very little.%研究了自制整理剂P在涤纶织物上的应用工艺和抗静电性能,并对其整理织物的色光、色牢度以及服用性能进行分析探讨.通过测量静电峰值电压、半衰期、接触角分析整理织物抗静电性能,检测经20次洗涤后抗静电性能的耐久性.测定抗弯长度、透气率和断裂强度,分析整理剂对涤纶织物服用性能的影响.测定整理前后织物的K/S值、色差、耐洗牢度和耐摩擦牢度,研究整理剂对染色织物色光和染色牢度的影响.结果表明:抗静电剂P整理的涤纶织物具有优良的抗静电性能和耐洗性能.无需焙烘工艺,最佳应用工艺为整理剂P5g/L,二浸二轧,轧余率70%~75%,70℃烘

  19. Study on Performance Comparison between Linen Fabric and Cotton Fabric%亚麻织物与棉织物性能对比研究

    Institute of Scientific and Technical Information of China (English)

    熊芳; 蒋颖刚; 眭建华

    2012-01-01

    选用规格、结构相近的亚麻织物和棉织物,测定样品的拉伸、撕破、磨损、抗皱、悬垂、透气、透湿等性能指标,通过对比分析探讨亚麻织物性能特征。结果表明:亚麻成品布的撕破、耐磨、抗皱、悬垂等性能差于棉成品布,而拉伸、透气、透湿等性能优于棉成品布。经处理后的亚麻成品布的断裂强力、撕破强力、耐磨性、抗皱性均有所降低,而透气、透湿及悬垂性能却均有所提高。%To explore the characteristics of linen fabric performance, we comparatively analysis the performance of linen fabric and cotton fabric, which are similar in specification and structure. A series of performance test are made, such as tensile, tear, wear, anti-wrinkle and drape, breathability, moisture permeability and other performance indicators. The results show that the performance of linen finished cloth, such as tear, wear, anti-wrinkle and drape performance, is worse than cotton finished fabrics. While the stretch, breathability and moisture permeability properties are superior to cotton finished fabrics. After treatment, the fracture strength, tear strength, abrasion resist- ance and wrinkle resistance of linen fabric are decrease. While the breathability, moisture permeability and drape are improved.

  20. Carbon Nanotube-Based Permeable Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Holt, J K; Park, H G; Bakajin, O; Noy, A; Huser, T; Eaglesham, D

    2004-04-06

    A membrane of multiwalled carbon nanotubes embedded in a silicon nitride matrix was fabricated for use in studying fluid mechanics on the nanometer scale. Characterization by fluorescent tracer diffusion and scanning electron microscopy suggests that the membrane is void-free near the silicon substrate on which it rests, implying that the hollow core of the nanotube is the only conduction path for molecular transport. Assuming Knudsen diffusion through this nanotube membrane, a maximum helium transport rate (for a pressure drop of 1 atm) of 0.25 cc/sec is predicted. Helium flow measurements of a nanoporous silicon nitride membrane, fabricated by sacrificial removal of carbon, give a flow rate greater than 1x10{sup -6} cc/sec. For viscous, laminar flow conditions, water is estimated to flow across the nanotube membrane (under a 1 atm pressure drop) at up to 2.8x10{sup -5} cc/sec (1.7 {micro}L/min).

  1. Small-bowel permeability in collagenous colitis

    DEFF Research Database (Denmark)

    Wildt, Signe; Madsen, Jan L; Rumessen, Jüri J

    2006-01-01

    OBJECTIVE: Collagenous colitis (CC) is a chronic inflammatory bowel disease that affects the colon. However, some patients with CC present with accompanying pathologic small-bowel manifestations such as coeliac disease, defects in bile acid absorption and histopathologic changes in small-intestin......OBJECTIVE: Collagenous colitis (CC) is a chronic inflammatory bowel disease that affects the colon. However, some patients with CC present with accompanying pathologic small-bowel manifestations such as coeliac disease, defects in bile acid absorption and histopathologic changes in small......-intestinal biopsies, indicating that CC is a pan-intestinal disease. In small-intestinal disease, the intestinal barrier function may be impaired, and the permeability of the small intestine altered. The purpose of this research was to study small-bowel function in patients with CC as expressed by intestinal...

  2. Composite binders for concrete with reduced permeability

    Science.gov (United States)

    Fediuk, R.; Yushin, A.

    2016-02-01

    Composite binder consisting of cement (55%), acid fly ash (40%) and limestone (5%) has been designed. It is obtained by co-milling to a specific surface of 550 kg/m2, it has an activity of 77.3 MPa and can produce a more dense cement stone structure. Integrated study revealed that the concrete on the composite binder basis provides an effective diffusion coefficient D. So we can conclude that the concrete layer protects buildings from toxic effects of expanded polystyrene. Low water absorption of the material (2.5% by weight) is due to the structure of its cement stone pore space. Besides lime powder prevents the penetration of moisture, reduces water saturation of the coverage that has a positive effect on useful life period. It also explains rather low water vapor permeability of the material - 0.021 mg/(m- hour-Pa).

  3. Lattice Boltzmann modelling of intrinsic permeability

    CERN Document Server

    Li, Jun; Wu, Lei; Zhang, Yonghao

    2016-01-01

    Lattice Boltzmann method (LBM) has been applied to predict flow properties of porous media including intrinsic permeability, where it is implicitly assumed that the LBM is equivalent to the incompressible (or near incompressible) Navier-Stokes equation. However, in LBM simulations, high-order moments, which are completely neglected in the Navier-Stokes equation, are still available through particle distribution functions. To ensure that the LBM simulation is correctly working at the Navier-Stokes hydrodynamic level, the high-order moments have to be negligible. This requires that the Knudsen number (Kn) is small so that rarefaction effect can be ignored. In this technical note, we elaborate this issue in LBM modelling of porous media flows, which is particularly important for gas flows in ultra-tight media.

  4. Cadmium substituted high permeability lithium ferrite

    Indian Academy of Sciences (India)

    S S Bellad; S C Watawe; A M Shaikh; B K Chougule

    2000-04-01

    Polycrystalline Li0.5–/2 Cd Fe2.5–/2O4 ferrites where = 0, 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6 were prepared by a double sintering ceramic technique and characterized by X-ray diffraction and scanning electron microscopy (SEM). The lattice parameter is found to increase monotonically with the cadmium content. It is explained in terms of the sizes of component ions. The grain size of the samples increases up to = 0.3 and then it decreases for higher values of . A similar trend is observed in the variation of Ms with Cd2+ content. The initial permeability () is however found to increase continuously with . The increase in is attributed to decrease of anisotropy constant K1 and higher grain size of the samples.

  5. Nitric oxide turnover in permeable river sediment

    DEFF Research Database (Denmark)

    Schreiber, Frank; Stief, Peter; Kuypers, Marcel M M;

    2014-01-01

    We measured nitric oxide (NO) microprofiles in relation to oxygen (O2) and all major dissolved N-species (ammonium, nitrate, nitrite, and nitrous oxide [N2O]) in a permeable, freshwater sediment (River Weser, Germany). NO reaches peak concentrations of 0.13 μmol L-1 in the oxic zone and is consumed...... in the oxic-anoxic transition zone. Apparently, NO is produced by ammonia oxidizers under oxic conditions and consumed by denitrification under microoxic conditions. Experimental percolation of sediment cores with aerated surface water resulted in an initial rate of NO production that was 12 times higher than...... the net NO production rate in steady state. This initial NO production rate is in the same range as the net ammonia oxidation rate, indicating that NO is transiently the main product of ammonia oxidizers. Stable isotope labeling experiments with the 15N-labeled chemical NO donor S...

  6. Parallel artificial membrane permeability assay for blood-brain permeability determination of illicit drugs and synthetic analogues.

    Science.gov (United States)

    Clemons, Kristina; Kretsch, Amanda; Verbeck, Guido

    2014-09-01

    With the number of designer drugs on the streets rampantly on the rise, it's becoming more and more important to be able to rapidly characterize them in a biologically relevant way. Using a parallel artificial membrane permeability assay (PAMPA) to assess the blood brain barrier permeability has shown to be a high throughput way to compare new drugs with currently controlled substances via their effective permeability values. This combined with direct infusion electrospray ionization-mass spectrometry creates a rapid technique for characterization of new designer drugs. PAMPA has successfully determined the effective permeabilities of cocaine, methamphetamine, heroin, MDMA, and several tryptamine derivatives.

  7. Numerical modeling and simulation of flow through porous fabric surface

    Science.gov (United States)

    Gao, Zheng; Li, Xiaolin

    We designed a numerical scheme to model the permeability of the fabric surface in an incompressible fluid by coupling the projection method with the Ghost Fluid Method in the front tracking framework. The pressure jump condition is obtained by adding a source term to the Poisson's equation in the projection step without modifications on its coefficients. The numerical results suggest that this approach has the ability to reproduce the relationship between pressure drop and relative velocity observed in the experiments. We use this algorithm to study the effects of porosity on the drag force and stability of parachutes during its inflation and deceleration.

  8. Back diffusion from thin low permeability zones.

    Science.gov (United States)

    Yang, Minjune; Annable, Michael D; Jawitz, James W

    2015-01-06

    Aquitards can serve as long-term contaminant sources to aquifers when contaminant mass diffuses from the aquitard following aquifer source mass depletion. This study describes analytical and experimental approaches to understand reactive and nonreactive solute transport in a thin aquitard bounded by an adjacent aquifer. A series of well-controlled laboratory experiments were conducted in a two-dimensional flow chamber to quantify solute diffusion from a high-permeability sand into and subsequently out of kaolinite clay layers of vertical thickness 15 mm, 20 mm, and 60 mm. One-dimensional analytical solutions were developed for diffusion in a finite aquitard with mass exchange with an adjacent aquifer using the method of images. The analytical solutions showed very good agreement with measured breakthrough curves and aquitard concentration distributions measured in situ by light reflection visualization. Solutes with low retardation accumulated more stored mass with greater penetration distance in the aquitard compared to high-retardation solutes. However, because the duration of aquitard mass release was much longer, high-retardation solutes have a greater long-term back diffusion risk. The error associated with applying a semi-infinite domain analytical solution to a finite diffusion domain increases as a function of the system relative diffusion length scale, suggesting that the solutions using image sources should be applied in cases with rapid solute diffusion and/or thin clay layers. The solutions presented here can be extended to multilayer aquifer/low-permeability systems to assess the significance of back diffusion from thin layers.

  9. Turbulent Hyporheic Exchange in Permeable Sediments

    Science.gov (United States)

    Roche, K. R.; Aubeneau, A. F.; Li, A.; Packman, A. I.

    2015-12-01

    Solute delivery from the water column into a streambed strongly influences metabolism in rivers. Current hydrological models simplify surface-subsurface (hyporheic) exchange by treating each domain separately, constraining turbulent flows to the water column. Studies have shown, however, that turbulence penetrates into permeable sediments. Evidence is lacking for how this highly coupled flow regime influences hyporheic exchange. We characterized the dynamics of turbulent exchange between surface and porewaters in a 2.5 m recirculating flume. The channel was packed with 3.8 cm PVC spheres to form a coarse gravel bed, with a total depth of 21 cm. We implanted microsensors onto an array of spheres to measure in situsalt concentrations within the streambed. Water was recirculated in the channel, and concentrated salt solution was continuously injected upstream of the sensor array. We observed solute exchange increased with free-stream Reynolds number and decreased with depth in the sediment bed. Mass of injected solute remaining in the bed decreased rapidly in all cases, with only 10-30% of mass recovered 50 cm downstream of the injection point at Re = 25,000. We observed high-frequency (1-10 Hz) concentration fluctuations at bed depths of at least 4.75 cm, and sporadic low-frequency fluctuations at depths of 12.5 cm. Spectral analysis revealed increased filtering of high frequencies with depth. We used particle-tracking simulations to fit depth-dependent turbulent diffusion profiles to experimental results. These results demonstrate that free-stream turbulence impacts hyporheic mixing deep into permeable streambeds, and mixing is strongly influenced by the coupled surface-subsurface flow field.

  10. Permeability of Dental Adhesives - A SEM Assessment.

    Science.gov (United States)

    Malacarne-Zanon, Juliana; de Andrade E Silva, Safira M; Wang, Linda; de Goes, Mario F; Martins, Adriano Luis; Narvaes-Romani, Eliene O; Anido-Anido, Andrea; Carrilho, Marcela R O

    2010-10-01

    To morphologically evaluate the permeability of different commercial dental adhesives using scanning electron microscopy. SEVEN ADHESIVE SYSTEMS WERE EVALUATED: one three-step system (Scotchbond Multi-Purpose - MP); one two-step self-etching primer system (Clearfil SE Bond - SE); three two-step etch-and-rinse systems (Single Bond 2 - SB; Excite - EX; One-Step - OS); and two single-step self-etching adhesives (Adper Prompt - AP; One-Up Bond F - OU). The mixture of primer and bond agents of the Clearfil SE Bond system (SE-PB) was also tested. The adhesives were poured into a brass mold (5.8 mm x 0.8 mm) and light-cured for 80 s at 650 mW/cm2. After a 24 h desiccation process, the specimens were immersed in a 50% ammoniac silver nitrate solution for tracer permeation. Afterwards, they were sectioned in ultra-fine slices, carbon-coated, and analyzed under backscattered electrons in a scanning electron microscopy. MP and SE showed slight and superficial tracer permeation. In EX, SB, and OS, permeation extended beyond the inner superficies of the specimens. SE-PB did not mix well, and most of the tracer was precipitated into the primer agent. In AP and OU, "water-trees" were observed all over the specimens. Different materials showed distinct permeability in aqueous solution. The extent of tracer permeation varied according to the composition of each material and it was more evident in the more hydrophilic and solvated ones.

  11. Permeability of alkaline magmas: a study from Campi Flegrei, Italy

    Science.gov (United States)

    Polacci, M.; Bouvet de Maissoneuve, C.; Giordano, D.; Piochi, M.; Degruyter, W.; Bachmann, O.; Mancini, L.

    2012-04-01

    Knowledge of permeability is of paramount importance for understanding the evolution of magma degassing during pre-, syn- and post-eruptive volcanic processes. Most permeability estimates existing to date refer to magmas of calc-alkaline compositions. We report here the preliminary results of permeability measurements performed on alkali-trachyte products erupted from the Campanian Ignimbrite (CI) and Monte Nuovo (MTN), two explosive eruptions from Campi Flegrei (CF), an active, hazardous caldera west of Naples, Southern Italy. Darcian (viscous) permeability spans a wide range between 10^-11 and 10^-14 m^2. We observe that the most permeable samples are the scoria clasts from the upper units of MTN; pumice samples from the Breccia Museo facies of CI are instead the least permeable. Non-Darcian (inertial) permeability follows the same trend as Darcian permeability. The first implication of this study is that porosity in alkaline as well as calc-alkaline magmas does not exert a first order control on permeability (e.g. the MTN samples are the most permeable but not the most porous). Second, sample geometry exhibits permeability anisotropy (higher permeability in the direction of vesicle elongation), suggesting stronger degassing in the vertical direction in the conduit. In addition, inertial effects are higher across the sample. As inertial effects are potentially generated by tortuosity (or tortuous vesicle paths), tortuosity is likely higher horizontally than vertically in the conduit. Finally, the measured CF permeability values overlap with those of rhyolitic pumice clasts from the Kos Plateau Tuff (Bouvet de Maisonneuve et al., 2009), together with CI one of the major Quaternary explosive eruptions of the Mediterranean region. This indicates that gas flow is strongly controlled by the geometry of the porous media, which is generated by the bubble dynamics during magma ascent. Therefore, permeability will depend on composition through the rheological properties

  12. Fabrication activity for nanophotonics

    DEFF Research Database (Denmark)

    Malureanu, Radu; Chung, Il-Sug; Carletti, Luca

    We present the fabrication and characterization of new structures and materials to be used in nanophotonics. The first structure presented is a fractal metallic metasurface designed to be used as a high-sensitivity sensor for 810nm wavelength. A second structure is a high index contrast grating...

  13. Crimp-Imbalanced Fabrics

    Science.gov (United States)

    2011-03-30

    tows (non-twisted yarns) of alternative cross-sections. Many ballistic fabrics employ non-circular cross-section yarns such as rectangular...coating. The temporary coatings can be wax (paraffin), latex (vinyl acetate , butadiene 27 and acrylic monomers), plastic (poly vinyl chloride

  14. Text-Fabric

    NARCIS (Netherlands)

    Roorda, Dirk

    2016-01-01

    Text-Fabric is a Python3 package for Text plus Annotations. It provides a data model, a text file format, and a binary format for (ancient) text plus (linguistic) annotations. The emphasis of this all is on: data processing; sharing data; and contributing modules. A defining characteristic is that T

  15. Non-isothermal two-phase flow in low-permeable porous media

    Science.gov (United States)

    Kolditz, O.; De Jonge, J.

    In this paper, we consider non-isothermal two-phase flow of two components (air and water) in gaseous and liquid phases in extremely low-permeable porous media through the use of the finite element method (FEM). Interphase mass transfer of the components between any of the phases is evaluated by assuming local thermodynamic equilibrium between the phases. Heat transfer occurs by conduction and multiphase advection. General equations of state for phase changes (Clausius-Clapeyron and Henry law) as well as multiphase properties for the low-permeable bentonites are implemented in the code. Additionally we consider the impact of swelling/shrinking processes on porosity and permeability changes. The numerical model is implemented in the context of the simulator RockFlow/RockMech (RF/RM), which is based on object-oriented programming techniques. The finite element formulations are written in terms of dimensionless quantities. This has proved to be advantageous for preconditioning composite system matrices of coupled multi-field problems. Three application examples are presented. The first one examines differences between the Richards' approximation and the multicomponent/multiphase approach, and between two numerical coupling schemes. The second example serves as partial verification against experimental results and to demonstrate coherence between different element types. The last example shows simultaneous desaturation and resaturation in one system.

  16. Remediation of DNAPLs in Low Permeability Soils. Innovative Technology Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    None

    2000-09-01

    Dense, non-aqueous phase liquid (DNAPL) compounds like trichloroethene (TCE) and perchloroethene (PCE) are prevalent at U. S. Department of Energy (DOE), other government, and industrial sites. Their widespread presence in low permeability media (LPM) poses severe challenges for assessment of their behavior and implementation of effective remediation technologies. Most remedial methods that involve fluid flow perform poorly in LPM. Hydraulic fracturing can improve the performance of remediation methods such as vapor extraction, free-product recovery, soil flushing, steam stripping, bioremediation, bioventing, and air sparging in LPM by enhancing formation permeability through the creation of fractures filled with high-permeability materials, such as sand. Hydraulic fracturing can improve the performance of other remediation methods such as oxidation, reductive dechlorination, and bioaugmentation by enhancing delivery of reactive agents to the subsurface. Hydraulic fractures are typically created using a 2-in. steel casing and a drive point pushed into the subsurface by a pneumatic hammer. Hydraulic fracturing has been widely used for more than 50 years to stimulate the yield of wells recovering oil from rock at great depth and has recently been shown to stimulate the yield of wells recovering contaminated liquids and vapors from LPM at shallow depths. Hydraulic fracturing is an enabling technology for improving the performance of some remedial methods and is a key element in the implementation of other methods. This document contains information on the above-mentioned technology, including description, applicability, cost, and performance data.

  17. Dyeing fabrics with metals

    Science.gov (United States)

    Kalivas, Georgia

    2002-06-01

    Traditionally, in textile dyeing, metals have been used as mordants or to improve the color produced by a natural or synthetic dye. In biomedical research and clinical diagnostics gold colloids are used as sensitive signals to detect the presence of pathogens. It has been observed that when metals are finely divided, a distinct color may result that is different from the color of the metal in bulk. For example, when gold is finely divided it may appear black, ruby or purple. This can be seen in biomedical research when gold colloids are reduced to micro-particles. Bright color signals are produced by few nanometer-sized particles. Dr. William Todd, a researcher in the Department of Veterinary Science at the Louisiana State University, developed a method of dyeing fabrics with metals. By using a reagent to bond the metal particles deep into the textile fibers and actually making the metal a part of the chemistry of the fiber. The chemicals of the fabric influence the resulting color. The combination of the element itself, the size of the particle, the chemical nature of the particle and the interaction of the metal with the chemistry of the fabric determine the actual hue. By using different elements, reagents, textiles and solvents a broad range of reproducible colors and tones can be created. Metals can also be combined into alloys, which will produce a variety of colors. The students of the ISCC chapter at the Fashion Institute of Technology dyed fabric using Dr. Todd's method and created a presentation of the results. They also did a demonstration of dyeing fabrics with metals.

  18. Fabrication of semi-transparent superoleophobic thin film from fabrics and nanoparticle-based hierarchical structure

    Directory of Open Access Journals (Sweden)

    Nishizawa S.

    2013-08-01

    Full Text Available Superoleophobic thin films have many potential applications including fluid transfer, fluid power systems, stain resistant and antifouling materials, and microfluidics among others. Transparency is also desired with superhydrophobicity for their numerous applications; however transparency and oleophobicity are almost incompatible relationship with each other in the point of surface structure. Because oleophobicity required rougher structure at nano-micro scale than hydrophobicity, and these rough structure brings light scattering. So far, there is very few report of the compatible of transparency and superoleophobicity. In this report, we proposed the see-through type fabrics using the nanoparticle-based hierarchical structure thin film for improving both of oleophobicity and transparency. The vacant space between fibrils of fabrics has two important roles: the one is to through the light, another one is to introduce air layer to realize Cassie state of liquid droplet on thin film. To realize the low surface energy and nanoscale rough structure surface on fibrils, we used the spray method with perfluoroalkyl methacrylic copolymer (PMC, silica nano particles and volatile solvent. From the SEM image, the hierarchical structures of nanoparticle were formed uniformly on the fabrics. The transparency of thin film obtained was approximately 61% and the change of transparency between pre-coated fabrics and coated was 11%. From investigation of the surface wettability, the contact angles of oils (rapeseed oil and hexadecane and water droplet on the fabricated film were over 150 degree.

  19. Nanocarbon foam: Fabrication, characterization and application

    Science.gov (United States)

    Liu, Teng

    This thesis is a continuous effort contributed to the field of developing a new type of functional porous materials - Nanocarbon Foam (NCF) by crosslinking multi-walled carbon nanotubes (MWNTs) into networks in three-dimensional (3D). Synthetic routes and characterizations of NCF, and their applications as strain-gauge sensors and electrode materials in lithium-air (Li-air) battery are described. In this research, the first accomplishment is proposing a robust methodology for creating superealstic 3D macroscopic NCF with controlled cellular structure. The key contributions contain: (1) understanding the premise of the design that gives the NCF with desired structure and porosity; (2) designing fabrication protocol for NCFs with controlled densities and macroscopic structure; (3) fabricating varied NCF with tunable porosity and structures, which in turn will endow the NCF with different characteristics. This experimental methodology for systematic and quantitative investigation of the processing-structure relationships provides a means for the fabrication optimization of NCF with desired structures. Though the mechanical, electronic, and thermal properties of CNTs have been extensively studied, for NCF that is a mixture of pristine and functionalized CNTs, it will not only have the collective behavior of the individual tubes, but will also have properties generated from the interactions between the tubes and engineered components. To understand the structure-properties relationship of NCF, the second accomplishment is studying the properties of obtained NCFs. Density, specific surface area, porosity, compressive behavior, mechanical robustness, electrical and electromechanical properties of NCF have been characterized in details. For comparison, properties originated from cellular structures built of other materials, such as polymeric foam, fiber aerogels, etc., are compared with that of NCF. Moreover, some engineering applications of NCF have been discussed. With

  20. Permeability of crust is key to crispness retention

    NARCIS (Netherlands)

    Hirte, A.; Hamer, R.J.; Meinders, M.B.J.; Primo-Martin, C.

    2010-01-01

    Bread loses crispness rapidly after baking because water originating from the wet crumb accumulates in the dry crust. This water accumulation might be increased by the dense and low permeable character of the bread crust. Our objective was to investigate the influence of permeability of the crust on

  1. Permeability dependence of streaming potential coefficient in porous media

    NARCIS (Netherlands)

    L.D. Thanh; R. Sprik

    2015-01-01

    In theory, the streaming potential coefficient depends not only on the zeta potential but also on the permeability of the rocks that partially determines the surface conductivity of the rocks. However, in practice, it is hard to show the permeability dependence of streaming potential coefficients be

  2. Permeability dependence of streaming potential coefficient in porous media

    NARCIS (Netherlands)

    Thanh, L.D.; Sprik, R.

    2015-01-01

    In theory, the streaming potential coefficient depends not only on the zeta potential but also on the permeability of the rocks that partially determines the surface conductivity of the rocks. However, in practice, it is hard to show the permeability dependence of streaming potential coefficients

  3. Duration of ultrasound-mediated enhanced plasma membrane permeability

    NARCIS (Netherlands)

    Lammertink, Bart; Deckers, Roel; Storm, Gert; Moonen, Chrit; Bos, Clemens

    2015-01-01

    Ultrasound (US) induced cavitation can be used to enhance the intracellular delivery of drugs by transiently increasing the cell membrane permeability. The duration of this increased permeability, termed temporal window, has not been fully elucidated. In this study, the temporal window was investiga

  4. Selective permeability of PVA membranes. I - Radiation-crosslinked membranes

    Science.gov (United States)

    Katz, M. G.; Wydeven, T., Jr.

    1981-01-01

    The water and salt transport properties of ionizing radiation crosslinked poly(vinyl alcohol) (PVA) membranes were investigated. The studied membranes showed high permeabilities and low selectivities for both water and salt. The results were found to be in accord with a modified solution-diffusion model for transport across the membranes, in which pressure-dependent permeability coefficients are employed.

  5. Selective Permeability of PVA Membranes. I: Radiation-Crosslinked Membranes

    Science.gov (United States)

    Katz, Moshe G.; Wydeven, Theodore, Jr.

    1981-01-01

    The water and salt transport properties of ionizing radiation crosslinked poly(vinyl alcohol) (PVA) membranes were investigated. The studied membranes showed high permeabilities and low selectivities for both water and salt. The results were found to be in accord with a modified solution-diffusion model for transport across the membranes, in which pressure-dependent permeability coefficients are employed.

  6. Recovery of Porosity and Permeability for High Plasticity Clays

    DEFF Research Database (Denmark)

    Krogsbøll, Anette; Foged, Niels Nielsen

    Clays, which have been loaded to a high stress level, will under certain conditions keep low porosity and permeability due to the high degree of compression. In some situations it seems that porosity and permeability will recover to a very high extent when the clay is unloaded. This seems...... the clay will expand to an even higher porosity....

  7. Duration of ultrasound-mediated enhanced plasma membrane permeability

    NARCIS (Netherlands)

    Lammertink, Bart; Deckers, Roel; Storm, Gerrit; Moonen, Chrit; Bos, Clemens

    2015-01-01

    Ultrasound (US) induced cavitation can be used to enhance the intracellular delivery of drugs by transiently increasing the cell membrane permeability. The duration of this increased permeability, termed temporal window, has not been fully elucidated. In this study, the temporal window was

  8. Permeability of crust is key to crispness retention

    NARCIS (Netherlands)

    Hirte, A.; Hamer, R.J.; Meinders, M.B.J.; Primo-Martin, C.

    2010-01-01

    Bread loses crispness rapidly after baking because water originating from the wet crumb accumulates in the dry crust. This water accumulation might be increased by the dense and low permeable character of the bread crust. Our objective was to investigate the influence of permeability of the crust on

  9. Nitrogen Transformations in Three Types of Permeable Pavement

    Science.gov (United States)

    In 2009, USEPA constructed a 0.4-ha (1-ac) parking lot at the Edison Environmental Center in Edison, NJ, that incorporated three different permeable pavement types - permeable interlocking concrete pavers (PICP), pervious concrete (PC), and porous asphalt (PA). The driving lanes...

  10. Formation and liquid permeability of dense colloidal cube packings

    NARCIS (Netherlands)

    Castillo, Sonja I R; Thies-Weesie, Dominique M E; Philipse, Albert P.

    2015-01-01

    The liquid permeability of dense random packings of cubic colloids with rounded corners is studied for solid hematite cubes and hollow microporous silica cubes. The permeabilities of these two types of packings are similar, confirming that the micropores in the silica shell of the hollow cubes do

  11. 21 CFR 876.5860 - High permeability hemodialysis system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false High permeability hemodialysis system. 876.5860... hemodialysis system. (a) Identification. A high permeability hemodialysis system is a device intended for use... toxemic conditions by performing such therapies as hemodialysis, hemofiltration, hemoconcentration,...

  12. Compliance Timeline for Printing, Coating, and Dyeing of Fabrics and Other Textiles National Emission Standards

    Science.gov (United States)

    This August 2003 document contains a diagram of dates and events for compliance with the National Emission Standards for Hazardous Air Pollutants (NESHAP) for Printing, Coating, and Dyeing of Fabrics and Other Textiles.

  13. Status report, canister fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Claes-Goeran; Eriksson, Peter; Westman, Marika [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Emilsson, Goeran [CSM Materialteknik AB, Linkoeping (Sweden)

    2004-06-01

    The report gives an account of the development of material and fabrication technology for copper canisters with cast inserts during the period from 2000 until the start of 2004. The engineering design of the canister and the choice of materials in the constituent components described in previous status reports have not been significantly changed. In the reference canister, the thickness of the copper shell is 50 mm. Fabrication of individual components with a thinner copper thickness is done for the purpose of gaining experience and evaluating fabrication and inspection methods for such canisters. As a part of the development of cast inserts, computer simulations of the casting processes and techniques used at the foundries have been performed for the purpose of optimizing the material properties. These properties have been evaluated by extensive tensile testing and metallographic inspection of test material taken from discs cut at different points along the length of the inserts. The testing results exhibit a relatively large spread. Low elongation values in certain tensile test specimens are due to the presence of poorly formed graphite, porosities, slag or other casting defects. It is concluded in the report that it will not be possible to avoid some presence of observed defects in castings of this size. In the deep repository, the inserts will be exposed to compressive loading and the observed defects are not critical for strength. An analysis of the strength of the inserts and formulation of relevant material requirements must be based on a statistical approach with probabilistic calculations. This work has been initiated and will be concluded during 2004. An initial verifying compression test of a canister in an isostatic press has indicated considerable overstrength in the structure. Seamless copper tubes are fabricated by means of three methods: extrusion, pierce and draw processing, and forging. It can be concluded that extrusion tests have revealed a

  14. Development of Coffee Carbon Cut Pile Knitted Fabric and Its Performance Study%咖啡炭割圈绒产品的开发与性能研究

    Institute of Scientific and Technical Information of China (English)

    张新杰; 丛洪莲

    2015-01-01

    In terms of the problems of the pure polyester cut pile fabrics with poor comfort and easy to breed bacteria,the paper develops a new kind of coffee carbon cut pile knitted fabric with good anti-bacterial and heat preservation properties,by using coffee carbon yarn and moisture absorption and fast-dry polyester DTY inter-knit⁃ted. In addition, the thermal and moist comfort properties and anti-bacterial of the product are tested and com⁃pared. The results show that the coffee carbon cut pile knitted fabric has excellent anti-bacterial,heat preserva⁃tion properties,warmth retention,air permeability and moisture transfer properties,whose anti-bacterial rate and warmth retention rate can reach 62.63% and 58.69%. In addition, the CLO value is 0.49, air permeability is 1 154 L/(m2·s),and the wicking effect of which is much better than that of pure polyester fabrics.%为解决纯涤纶割圈绒产品舒适性差、易滋生细菌等问题,利用咖啡炭纱与吸湿快干涤纶低弹丝交织,开发一款咖啡炭割圈绒产品。详细介绍编织工艺,如设备参数、原料选择、织针排列、编织图等,以及染色和后整理工艺等。测试该咖啡炭割圈绒织物的热湿性和抗菌性,结果表明:该产品具有良好的抗菌性、保暖性、透气性及导湿性,其抑菌率为62.63%、58.69%,保温率为54.81%,克罗值为0.49,透气量为1154 L/(m2·s),芯吸效应明显优于纯涤纶织物,为纬编割圈绒家居面料和服装用面料的开发提供参考。

  15. Microwave complex permeability of Fe3O4 nanoflake composites with and without magnetic field-induced rotational orientation

    Science.gov (United States)

    Liu, Xianguo; Wing Or, Siu; Ming Leung, Chung; Ho, S. L.

    2013-05-01

    Magnetite (Fe3O4) nanoflakes with widths of 100-200 nm and thicknesses of 10-80 nm were prepared by a hydrothermal synthesis method. Fe3O4 nanoflake composites with and without magnetic field-induced rotational orientation of flake planes of Fe3O4 nanoflakes in paraffin binder were fabricated using 35 wt. % Fe3O4 nanoflakes. The rotationally oriented composite showed higher permeability and resonance frequency than the nonoriented one, and its value of (μ0-1)fr reached 214.8 GHz and exceeded the Snoek's limit. Considering a uniform and a random distribution of flake planes of Fe3O4 nanoflakes in the oriented and nonoriented composites, respectively, the complex permeability of both composites was calculated using the Landau-Lifshitz-Gilbert equation and the Bruggeman's effective medium theory in the 2-18 GHz microwave frequency range.

  16. Chloride permeability of concrete under static and repeated compressive loading

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Mitsuru; Ishimori, Hiroshi [Kanazawa Inst. of Technology, Ishikawa (Japan)

    1995-05-01

    The chloride permeability of normal weight concrete subjected to static and repeated compressive loading was evaluated by using the AASHTO T277 test method. The results of concrete under static loading showed that the application of loads up to 90% of the ultimate strength had little effect on the chloride permeability. It was found from the results of concrete under repeated loading that load repetitions at the maximum stress levels of 60% or more caused the chloride permeability to increase significantly. The test results also indicated that the chloride permeability of concrete subjected to static and repeated loading increased at an increasing rate with its residual strain. The relation between the chloride permeability obtained and the cracking behavior of concrete previously reported was discussed.

  17. Two-phase relative permeability models in reservoir engineering calculations

    Energy Technology Data Exchange (ETDEWEB)

    Siddiqui, S.; Hicks, P.J.; Ertekin, T.

    1999-01-15

    A comparison of ten two-phase relative permeability models is conducted using experimental, semianalytical and numerical approaches. Model predicted relative permeabilities are compared with data from 12 steady-state experiments on Berea and Brown sandstones using combinations of three white mineral oils and 2% CaCl1 brine. The model results are compared against the experimental data using three different criteria. The models are found to predict the relative permeability to oil, relative permeability to water and fractional flow of water with varying degrees of success. Relative permeability data from four of the experimental runs are used to predict the displacement performance under Buckley-Leverett conditions and the results are compared against those predicted by the models. Finally, waterflooding performances predicted by the models are analyzed at three different viscosity ratios using a two-dimensional, two-phase numerical reservoir simulator. (author)

  18. Permeability characterization of polymer matrix composites by RTM/VARTM

    Science.gov (United States)

    Naik, N. K.; Sirisha, M.; Inani, A.

    2014-02-01

    Cost effective manufacturing of high performance polymer matrix composite structures is an important consideration for the growth of its use. Resin transfer moulding (RTM) and vacuum assisted resin transfer moulding (VARTM) are the efficient processes for the cost effective manufacturing. These processes involve transfer of resin from the tank into the reinforcing preform loaded into a closed mould. Resin flow within the preform and reinforcement wetting can be characterized using the permeability properties. Different reinforcement and resin properties and process parameters affecting the permeability are discussed based on state of art literature review covering experimental studies. General theory for the determination of permeability is presented. Based on the literature review, permeability values for different reinforcement architecture, resin and processing conditions are presented. Further, possible sources of error during experimental determination of permeability and issues involved with reproducibility are discussed.

  19. Permeability of mono- and bi-dispersed porous media

    Directory of Open Access Journals (Sweden)

    Kim S.J.

    2013-04-01

    Full Text Available In this study, the permeability of mono- and bi-dispersed porous media is considered. The effects of the particle size distribution and the packing structure of particles on the permeability are investigated experimentally and analytically. Both experimental and analytic results suggest that the particlesize distribution is close to the log-normal distribution, and the permeability of the mono-dispersed porous media quasi-linearly decreases as the range of the particle size distribution increases. On the other hand, the effect of packing structure of particles on the permeability is shown to be negligible.The permeability of the bidispersed porous media quasi-linearly decreases as the range of cluster size increases, and nearly independent of the particle size distribution. The present model is valid over the range of parameters typically found in heat transfer applications.

  20. Stochastic back analysis of permeability coefficient using generalized Bayesian method

    Institute of Scientific and Technical Information of China (English)

    Zheng Guilan; Wang Yuan; Wang Fei; Yang Jian

    2008-01-01

    Owing to the fact that the conventional deterministic back analysis of the permeability coefficient cannot reflect the uncertainties of parameters, including the hydraulic head at the boundary, the permeability coefficient and measured hydraulic head, a stochastic back analysis taking consideration of uncertainties of parameters was performed using the generalized Bayesian method. Based on the stochastic finite element method (SFEM) for a seepage field, the variable metric algorithm and the generalized Bayesian method, formulas for stochastic back analysis of the permeability coefficient were derived. A case study of seepage analysis of a sluice foundation was performed to illustrate the proposed method. The results indicate that, with the generalized Bayesian method that considers the uncertainties of measured hydraulic head, the permeability coefficient and the hydraulic head at the boundary, both the mean and standard deviation of the permeability coefficient can be obtained and the standard deviation is less than that obtained by the conventional Bayesian method. Therefore, the present method is valid and applicable.

  1. Hyperbolic Metamaterial Feasible for Fabrication with Direct Laser Writing Processes

    CERN Document Server

    Zhang, Xu; Güney, Durdu Ö

    2015-01-01

    Stimulated emission depletion microscopy inspired direct laser writing (STED-DLW) processes can offer diffraction-unlimited fabrication of 3D-structures, not possible with traditional electron-beam or optical lithography. We propose a hyperbolic metamaterial for fabrication with STED-DLW. First, we design meandering wire structures with three different magnetic dipoles which can be excited under different incidences of light. Then, based on effective parameters corresponding to normal incidence and lateral incidence, we find that the hyperbolic dispersion relation for five-layer structure appears between 15THz to 20THz. Finally, we investigate the influence of imaginary parts of the effective parameters on the metamaterial dispersion. The proposed metamaterial structure has also potential for three-dimensionally isotropic permeability despite geometric anisotropy.

  2. The fabrication and microwave characterisation of ferromagnetic thin films

    CERN Document Server

    Hood, K A

    2001-01-01

    This thesis discusses work carried out on the examination of the magnetic and microwave properties of samples based on the ferromagnetic material, METGLAS 2605SC. Sputter deposited thin film samples were stacked together to produce arrays and their permittivity and permeability was measured over a frequency range of 8-12 GHz. Powdered METGLAS 2605SC was mixed with wax and moulded to form composite samples for similar testing over the frequency range 2-20 GHz. The fabrication of the samples was monitored at each stage, and the measurement techniques were shown to be precise and accurate. Similar work in this field is discussed, as is the basic theory used in this project. It is hoped that this thesis constitutes a comprehensive text on the fabrication and measurement and analysis of magnetic samples at microwave frequencies should this work he continued.

  3. Permeability, storage and hydraulic diffusivity controlled by earthquakes

    Science.gov (United States)

    Brodsky, E. E.; Fulton, P. M.; Xue, L.

    2016-12-01

    Earthquakes can increase permeability in fractured rocks. In the farfield, such permeability increases are attributed to seismic waves and can last for months after the initial earthquake. Laboratory studies suggest that unclogging of fractures by the transient flow driven by seismic waves is a viable mechanism. These dynamic permeability increases may contribute to permeability enhancement in the seismic clouds accompanying hydraulic fracking. Permeability enhancement by seismic waves could potentially be engineered and the experiments suggest the process will be most effective at a preferred frequency. We have recently observed similar processes inside active fault zones after major earthquakes. A borehole observatory in the fault that generated the M9.0 2011 Tohoku earthquake reveals a sequence of temperature pulses during the secondary aftershock sequence of an M7.3 aftershock. The pulses are attributed to fluid advection by a flow through a zone of transiently increased permeability. Directly after the M7.3 earthquake, the newly damaged fault zone is highly susceptible to further permeability enhancement, but ultimately heals within a month and becomes no longer as sensitive. The observation suggests that the newly damaged fault zone is more prone to fluid pulsing than would be expected based on the long-term permeability structure. Even longer term healing is seen inside the fault zone of the 2008 M7.9 Wenchuan earthquake. The competition between damage and healing (or clogging and unclogging) results in dynamically controlled permeability, storage and hydraulic diffusivity. Recent measurements of in situ fault zone architecture at the 1-10 meter scale suggest that active fault zones often have hydraulic diffusivities near 10-2 m2/s. This uniformity is true even within the damage zone of the San Andreas fault where permeability and storage increases balance each other to achieve this value of diffusivity over a 400 m wide region. We speculate that fault zones

  4. Quantifying porosity and permeability of fractured carbonates and fault rocks in natural groundwater reservoirs

    Science.gov (United States)

    Pirmoradi, Reza; Wolfmayr, Mariella; Bauer, Helene; Decker, Kurt

    2017-04-01

    This study presents porosity and permeability data for a suite of different carbonate rocks from two major groundwater reservoirs in eastern Austria that supply more than 60% of Vienna`s drinking water. Data includes a set of lithologically different, unfractured host rocks, fractured rocks with variable fracture intensities, and fault rocks such as dilation breccias, different cataclasites and dissolution-precipitation fault rocks. Fault rock properties are of particular importance, since fault zones play an important role in the hydrogeology of the reservoirs. The reservoir rocks are exposed at two major alpine karst plateaus in the Northern Calcareous Alps. They comprise of various Triassic calcareous strata of more than 2 km total thickness that reflect facies differentiation since Anisian times. Rocks are multiply deformed resulting in a partly dense network of fractures and faults. Faults differ in scale, fault rock content, and fault rock volumes. Methods used to quantify the porosity and permeability of samples include a standard industry procedure that uses the weight of water saturated samples under hydrostatic uplift and in air to determine the total effective (matrix and fracture) porosity of rocks, measurements on plugs with a fully automated gas porosity- and permeameter using N2 gas infiltrating plugs under a defined confining pressure (Coreval Poro 700 by Vinci technologies), and percolation tests. The latter were conducted in the field along well known fault zones in order to test the differences in fractured rock permeability in situ and on a representative volume, which is not ensured with plug measurements. To calculate hydraulic conductivity by the Darcy equation the measured elapsed time for infiltrating a standard volume of water into a small borehole has been used. In general, undisturbed host rock samples are all of low porosity (average around 1%). The open porosity of the undisturbed rocks belonging to diverse formations vary from 0

  5. Preparation of highly permeable BPPO microfiltration membrane with binary porous structures on a colloidal crystal substrate by the breath figure method.

    Science.gov (United States)

    Yuan, Hua; Yu, Bing; Cong, Hailin; Peng, Qiaohong; Yang, Zhen; Luo, Yongli; Chi, Ming

    2016-01-01

    A highly permeable brominated poly(phenylene oxide) (BPPO) microfiltration membrane with binary porous structures was fabricated by combination of the breath figure and colloidal crystal template methods. The pore size in the bottom layer of the membrane was adjusted by the diameter of SiO2 microspheres in the colloidal crystal template, while the pore size in the top layer of the membrane was adjusted by varying the BPPO concentration in the casting solution. The permeability of the membrane cast on the colloidal crystal substrate was much higher than that of the membrane cast on a bare silicon wafer. The binary porous BPPO membrane with high permeability and antifouling property was used for microfiltration applications.

  6. Extreme Rainfall Impacts in Fractured Permeable Catchments

    Science.gov (United States)

    Ireson, A. M.; Butler, A. P.

    2009-12-01

    Serious groundwater flooding events have occurred on Chalk catchments in both the UK and north west Europe in the last decade, causing substantial amounts of disruption and economic damage. These fractured, permeable catchments are characterized by low surface runoff, high baseflow indices and strongly attenuated streamflow hydrographs. They have a general resilience to drought and pluvial/fluvial flooding. The small pore size of the Chalk matrix (~ 1 µm) exerts a high suction, such that dynamic storage is primarily due to the fractures, and amounts to ~ 1% of the total volume. As a result, under sustained rainfall the water table can rise up to exceptional levels leading to surface water emergence from springs and valleys. Floodwater may slowly drain with the topography, or, in localized depressions, it may simply pond until the groundwater levels decline. In winter 2000/1, a sequence of individually unexceptional rainfall events over several months led to large scale flooding in the Pang catchment, Berkshire, UK. By contrast, an extreme rainfall event on 20th July 2007 in the same catchment caused a very rapid response at the water table, but due to the antecedent conditions did not lead to flooding. The objective of this study is to quantify how the water table in a fractured permeable catchment responds to different types of rainfall, and the implications of this for groundwater flooding. We make use of measurements from the Pang catchment, including: rainfall (tipping bucket gauges); actual evaporation (eddy flux correlation); soil water content (profile probes and neutron probes); near surface matric potential (tensiometers and equitensiometers); deep (>10m) matric potential (deep jacking tensiometers); and water table elevation (piezometers). Conventional treatment of recharge in Chalk aquifers considers a fixed bypass component of rainfall, normally 15%, to account for the role of the fractures. However, interpretation of the field data suggest three modes

  7. Materials for microfluidic chip fabrication.

    Science.gov (United States)

    Ren, Kangning; Zhou, Jianhua; Wu, Hongkai

    2013-11-19

    Through manipulating fluids using microfabricated channel and chamber structures, microfluidics is a powerful tool to realize high sensitive, high speed, high throughput, and low cost analysis. In addition, the method can establish a well-controlled microenivroment for manipulating fluids and particles. It also has rapid growing implementations in both sophisticated chemical/biological analysis and low-cost point-of-care assays. Some unique phenomena emerge at the micrometer scale. For example, reactions are completed in a shorter amount of time as the travel distances of mass and heat are relatively small; the flows are usually laminar; and the capillary effect becomes dominant owing to large surface-to-volume ratios. In the meantime, the surface properties of the device material are greatly amplified, which can lead to either unique functions or problems that we would not encounter at the macroscale. Also, each material inherently corresponds with specific microfabrication strategies and certain native properties of the device. Therefore, the material for making the device plays a dominating role in microfluidic technologies. In this Account, we address the evolution of materials used for fabricating microfluidic chips, and discuss the application-oriented pros and cons of different materials. This Account generally follows the order of the materials introduced to microfluidics. Glass and silicon, the first generation microfluidic device materials, are perfect for capillary electrophoresis and solvent-involved applications but expensive for microfabriaction. Elastomers enable low-cost rapid prototyping and high density integration of valves on chip, allowing complicated and parallel fluid manipulation and in-channel cell culture. Plastics, as competitive alternatives to elastomers, are also rapid and inexpensive to microfabricate. Their broad variety provides flexible choices for different needs. For example, some thermosets support in-situ fabrication of

  8. Fabrication of diamond shells

    Energy Technology Data Exchange (ETDEWEB)

    Hamza, Alex V.; Biener, Juergen; Wild, Christoph; Woerner, Eckhard

    2016-11-01

    A novel method for fabricating diamond shells is introduced. The fabrication of such shells is a multi-step process, which involves diamond chemical vapor deposition on predetermined mandrels followed by polishing, microfabrication of holes, and removal of the mandrel by an etch process. The resultant shells of the present invention can be configured with a surface roughness at the nanometer level (e.g., on the order of down to about 10 nm RMS) on a mm length scale, and exhibit excellent hardness/strength, and good transparency in the both the infra-red and visible. Specifically, a novel process is disclosed herein, which allows coating of spherical substrates with optical-quality diamond films or nanocrystalline diamond films.

  9. Atomically Traceable Nanostructure Fabrication.

    Science.gov (United States)

    Ballard, Josh B; Dick, Don D; McDonnell, Stephen J; Bischof, Maia; Fu, Joseph; Owen, James H G; Owen, William R; Alexander, Justin D; Jaeger, David L; Namboodiri, Pradeep; Fuchs, Ehud; Chabal, Yves J; Wallace, Robert M; Reidy, Richard; Silver, Richard M; Randall, John N; Von Ehr, James

    2015-07-17

    Reducing the scale of etched nanostructures below the 10 nm range eventually will require an atomic scale understanding of the entire fabrication process being used in order to maintain exquisite control over both feature size and feature density. Here, we demonstrate a method for tracking atomically resolved and controlled structures from initial template definition through final nanostructure metrology, opening up a pathway for top-down atomic control over nanofabrication. Hydrogen depassivation lithography is the first step of the nanoscale fabrication process followed by selective atomic layer deposition of up to 2.8 nm of titania to make a nanoscale etch mask. Contrast with the background is shown, indicating different mechanisms for growth on the desired patterns and on the H passivated background. The patterns are then transferred into the bulk using reactive ion etching to form 20 nm tall nanostructures with linewidths down to ~6 nm. To illustrate the limitations of this process, arrays of holes and lines are fabricated. The various nanofabrication process steps are performed at disparate locations, so process integration is discussed. Related issues are discussed including using fiducial marks for finding nanostructures on a macroscopic sample and protecting the chemically reactive patterned Si(100)-H surface against degradation due to atmospheric exposure.

  10. Density and permeability of a loess soil: long-term organic matter effect and the response to compressive stress

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Schjønning, Per; Møldrup, Per

    2013-01-01

    Pa). Investigated indicators for compression resistance included compression index, precompression stress, and resistance and resilience indices based on measured soil physical properties (bulk density, air-filled porosity, air permeability, and void ratio). Soil resilience was assessed following exposure...... of compacted cores to freeze-thaw (FT) and wet-dry (WD) cycles. The OC content increased with increased fertilisation and resulted in decreased initial bulk density, higher air-filled and total porosities, and increased organisation of the pore space. Soil resistance decreased with increasing OC content...... but the correlation was not significant. However, initial bulk density (ρbi) and initial gravimetric water content (wi) were significantly positively correlated to the indices of soil compression resistance, with the effect of ρbi being significantly stronger. Significant recovery of airfilled porosity and air...

  11. 智能防水透湿聚氨酯研究进展%Development of Shape Memory Polyurethane on Intelligent Waterproof and Water Vapour Permeable

    Institute of Scientific and Technical Information of China (English)

    王玮玲; 于伟东

    2014-01-01

    简要介绍了实现形状记忆聚氨酯( SMPU)的智能透湿机理,综述了SMPU在智能透湿性方面的研究进展及智能防水透湿膜和织物研究中存在的问题,提出了研究开发具有创新功能的智能防水透湿织物是未来纺织工业发展的趋势。%The mechanism of waterproof and water vapor permeable of shape memory polyurethane was brief in⁃troduced. The research progress of shape memory polyurethane(SMPU) in intelligent water vapor permeability and problem which existed in membrane and fabrics of smart waterproof breathable were summerized. The research of in⁃telligent water proof and breathable fabrics with innovation function was the trend of textiles in the future.

  12. Drainage hydraulics of permeable friction courses

    Science.gov (United States)

    Charbeneau, Randall J.; Barrett, Michael E.

    2008-04-01

    This paper describes solutions to the hydraulic equations that govern flow in permeable friction courses (PFC). PFC is a layer of porous asphalt approximately 50 mm thick that is placed as an overlay on top of an existing conventional concrete or asphalt road surface to help control splash and hydroplaning, reduce noise, and enhance quality of storm water runoff. The primary objective of this manuscript is to present an analytical system of equations that can be used in design and analysis of PFC systems. The primary assumptions used in this analysis are that the flow can be modeled as one-dimensional, steady state Darcy-type flow and that slopes are sufficiently small so that the Dupuit-Forchheimer assumptions apply. Solutions are derived for cases where storm water drainage is confined to the PFC bed and for conditions where the PFC drainage capacity is exceeded and ponded sheet flow occurs across the pavement surface. The mathematical solutions provide the drainage characteristics (depth and residence time) as a function of rainfall intensity, PFC hydraulic conductivity, pavement slope, and maximum drainage path length.

  13. Electrically Driven Ion Separations in Permeable Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Bruening, Merlin [Michigan State Univ., East Lansing, MI (United States)

    2017-04-21

    Membranes are attractive for a wide range of separations due to their low energy costs and continuous operation. To achieve practical fluxes, most membranes consist of a thin, selective skin on a highly permeable substrate that provides mechanical strength. Thus, this project focused on creating new methods for forming highly selective ultrathin skins as well as modeling transport through these coatings to better understand their unprecedented selectivities. The research explored both gas and ion separations, and the latter included transport due to concentration, pressure and electrical potential gradients. This report describes a series of highlights of the research and then provides a complete list of publications supported by the grant. These publications have been cited more than 4000 times. Perhaps the most stunning finding is the recent discovery of monovalent/divalent cation and anion selectivities around 1000 when modifying cation- and anion-exchange membranes with polyelectrolyte multilayers (PEMs). This discovery builds on many years of exciting research. (Citation numbers refer to the journal articles in the bibliography.)

  14. Second law violations, continuum mechanics, and permeability

    Science.gov (United States)

    Ostoja-Starzewski, Martin

    2016-03-01

    The violations of the second law are relevant as the length and/or time scales become very small. The second law then needs to be replaced by the fluctuation theorem and mathematically, the irreversible entropy is a submartingale. First, we discuss the consequences of these results for the axioms of continuum mechanics, arguing in favor of a framework relying on stochastic functionals of energy and entropy. We next determine a Lyapunov function for diffusion-type problems governed by stochastic rather than deterministic functionals of internal energy and entropy, where the random field coefficients of diffusion are not required to satisfy the positive definiteness everywhere. Next, a formulation of micropolar fluid mechanics is developed, accounting for the lack of symmetry of stress tensor on molecular scales. This framework is then applied to employed to show that spontaneous random fluctuations of the microrotation field will arise in Couette—and Poiseuille-type flows in the absence of random (turbulence-like) fluctuations of the classical velocity field. Finally, while the permeability is classically modeled by the Darcy law or its modifications, besides considering the violations of the second law, one also needs to account for the spatial randomness of the channel network, implying a modification of the hierarchy of scale-dependent bounds on the macroscopic property of the network.

  15. Design and Fabrication of Pneumatic Powered Two Wheeler

    Directory of Open Access Journals (Sweden)

    P.Madhu Raghava

    2017-05-01

    Full Text Available This project is design, fabrication and development of a design and fabrication of pneumatic bicycle it is rear wheel drive. The conceptual design of this model is taken from manually operated bicycle. The complete body looks like a bicycle in which manual operation followed .this product is a pneumatic vehicle, useful for handicapped people, and also normal persons. The power transmission takes place from rear wheel through chain drive. The entire arrangement of power transmission by means of connecting rod of the actuator is taken along with the chain sprocket. When the cylinder is connected to, it would give a driving force due the pressure at which air is sent. Only one person is allowed on the bicycle at any time. The material, mild steel is choose as a main structure fastening by joint, and main components of this project is , air cylinder, solenoid valve, electrical control unit, pneumatic actuator, power transmitting chain, sprocket wheel, two wheeler rear wheel components of model attach by welding, part by part create then be fabricating together. At the end of the project, the model is tested by several people and their comment then being recorded and performed some tests. The concept of compressed air bicycle in practice reduces the air pollution to large extend as its exhaust is nothing but air.

  16. Update to Permeable Pavement Research at the Edison Environmental Center - proceedings

    Science.gov (United States)

    The EPA’s Urban Watershed Management Branch (UWMB) has been monitoring the permeable pavement demonstration site at the Edison Environmental Center, NJ since 2010. This site has three different types of permeable pavements including interlocking concrete permeable pavers, p...

  17. Fabrication of High T

    Science.gov (United States)

    Apperley, Miles Hyam

    1992-01-01

    Metal-clad high-T_{rm c} superconductor wires have been fabricated by conventional hot extrusion and wire drawing techniques. The fabrication processes which were used influenced the microstructure which, in turn, governed the superconducting properties of metal-clad Y-Ba-Cu-O (YBCO) and Bi-Pb-Sr-Ca-Cu-O (BPSCCO) superconductors. The ability to form these materials into long thin wires and the electrical properties of the wires were assessed. Extruded metal-clad wire was fabricated by coextruding a Cu billet containing a Ag-clad superconductor core at 920^circC and 800 ^circC for YBCO and BPSCCO materials, respectively. The deformation behaviour of the composite billets was investigated by extruding through dies with semicone angle alpha = 30 ^circ and using a range of core diameters and reduction ratios. For combinations of initial core diameter and reduction ratio, domains of deformation behaviour were established including sound flow, nonuniform flow, core fracture and sleeve fracture. Hot extruded YBCO and BPSCCO superconductor had densities estimated to be between 95% and 98% of the theoretical values. The material contained transverse cracks except for a sample of YBCO which had an addition of 10 wt% Ag. The microstructure of the YBCO material consisted of YBa _2Cu_3O{_{7-x}}, while the BPSCCO material contained an intimate mixture of the high-T _{rm c} (Bi,Pb)_2 Sr_2Ca_2Cu _3O{_ {10-x}} (110 K) and low-T _{rm c} (Bi,Pb)_2 Sr_2Ca_1Cu _2O{_ {8-x}} (80 K) phases with Ca _2CuO_3 and Sr-Ca -Cu-O impurity particles. X-ray polefigure goniometry of extruded BPSCCO superconductor revealed that the material was relatively untextured. As-extruded YBCO and BPSCCO were semiconducting. Oxygen treated YBCO had a lower normal-state resistivity than the as-extruded material, and a superconducting transition above 77 K was not achieved. Heat treatment of extruded BPSCCO regenerated superconductivity above 77 K, with the transition behaviour dependent on the proportion of high

  18. Hydrogen permeable high-temperature membranes. Development and application in gas separation processes and in hydrogen-producing reactions for process heat utilization. Wasserstoffpermeable Hochtemperaturmembranen. Entwicklung und Einsatz in Gastrennprozessen und in Wasserstoff erzeugenden Reaktionen zur Nutzung von Prozesswaerme

    Energy Technology Data Exchange (ETDEWEB)

    Weirich, W.

    1990-04-03

    The thesis deals with hydrogen-permeable, high-temperature membranes consisting of metal-bare or ceramic-base materials, discussing their fabrication and properties as well as the analyses and experimentes performed for studying the applicability of these membranes in hydrogen production processes or in energy conversion processes for the utilization of process heat from HTGR-type reactors. (orig.)

  19. An apparent permeability model of shale gas under formation conditions

    Science.gov (United States)

    Chen, Peng; Jiang, Shan; Chen, Yan; Wang, Shanshan

    2017-08-01

    There are various types of pores in shale, mainly consisting of nanopores and micropores, causing flow regime variations and apparent permeability changes during the development of the reservoir. In this paper, a Knudsen number calculation model is proposed with the actual conditions of gas in a shale reservoir. Then, based on the distribution of pores in shale, an apparent permeability model is established using hydrodynamics, and a calculation method is put forward for the actual permeability of a reservoir. Finally, the Knudsen number model and the permeability correction coefficient model are used to analyze the flow regime and permeability correction coefficients in pores during the development of the shale gas reservoir. Results show that with a decreasing of pressure, the Knudsen number increases, the flow regime changes from continuous flow and slip flow to transition flow or free molecular flow. When the Knudsen number is Kn > 0.1, and with a further increasing of Kn, gas molecule slippage greatly intensifies and the permeability correction coefficient K app/Kd significantly increases. While the Knudsen number increases, the permeability correction coefficient significantly increases in the micropores and the small pores, but this does not appear in the macropores and the mesopores. These results can be used to guide flow regime analysis and production forecasting in shale gas reservoirs.

  20. Characterization and estimation of permeability correlation structure from performance data

    Energy Technology Data Exchange (ETDEWEB)

    Ershaghi, I.; Al-Qahtani, M. [Univ. of Southern California, Los Angeles, CA (United States)

    1997-08-01

    In this study, the influence of permeability structure and correlation length on the system effective permeability and recovery factors of 2-D cross-sectional reservoir models, under waterflood, is investigated. Reservoirs with identical statistical representation of permeability attributes are shown to exhibit different system effective permeability and production characteristics which can be expressed by a mean and variance. The mean and variance are shown to be significantly influenced by the correlation length. Detailed quantification of the influence of horizontal and vertical correlation lengths for different permeability distributions is presented. The effect of capillary pressure, P{sub c1} on the production characteristics and saturation profiles at different correlation lengths is also investigated. It is observed that neglecting P{sub c} causes considerable error at large horizontal and short vertical correlation lengths. The effect of using constant as opposed to variable relative permeability attributes is also investigated at different correlation lengths. Next we studied the influence of correlation anisotropy in 2-D reservoir models. For a reservoir under five-spot waterflood pattern, it is shown that the ratios of breakthrough times and recovery factors of the wells in each direction of correlation are greatly influenced by the degree of anisotropy. In fully developed fields, performance data can aid in the recognition of reservoir anisotropy. Finally, a procedure for estimating the spatial correlation length from performance data is presented. Both the production performance data and the system`s effective permeability are required in estimating the correlation length.