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Sample records for non-porous separating layer

  1. Capillary liquid chromatography separations using non-porous pillar array columns

    NARCIS (Netherlands)

    de Malsche, Wim; de Bruyne, S.; op de Beek, J.; Sandra, P.; Gardeniers, Johannes G.E.; Desmet, G.; Lynen, F.

    2012-01-01

    We report on a series of explorative experiments wherein a non-porous pillar array column (NP-PAC) is coupled to a commercial capillary LC instrument. The performance of the system was evaluated by both non-retained and retained experiments using several types of samples. In order to minimize

  2. Capillary liquid chromatography separations using non-porous pillar array columns

    NARCIS (Netherlands)

    Malsche, de D.M.W.; Bruyne, de S.; Beek, op de J.; Sandra, P.; Gardeniers, J.G.E.; Desmet, G.; Lynen, F.

    2012-01-01

    We report on a series of explorative experiments wherein a non-porous pillar array column (NP-PAC) is coupled to a commercial capillary LC instrument. The performance of the system was evaluated by both non-retained and retained experiments using several types of samples. In order to minimize interf

  3. Non-porous metal membranes for selective separation of hydrogen from gas mixtures at higher temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Winkelmann, U.; Schulten, R.; Weirich, W.; Kuegler, B.; Luecke, L.; Oertel, M.; Pietsch, M.; Schmitz, J.

    1986-10-01

    Materials for selective separation of hydrogen from gas mixtures by means of a metal membrane must have high permeability for dissolved oxygen, catalytically active surfaces, and mechanical stability in a hydrogen atmosphere. The transition metals Nb, Ta, and V have high hydrogen permeability, but they must be coated with a catalytically active Pd alloy in order to permit hydrogen permeation. The alloy TiNi can be used without a noble metal coating.

  4. Dense, layered membranes for hydrogen separation

    Science.gov (United States)

    Roark, Shane E.; MacKay, Richard; Mundschau, Michael V.

    2006-02-21

    This invention provides hydrogen-permeable membranes for separation of hydrogen from hydrogen-containing gases. The membranes are multi-layer having a central hydrogen-permeable layer with one or more catalyst layers, barrier layers, and/or protective layers. The invention also relates to membrane reactors employing the hydrogen-permeable membranes of the invention and to methods for separation of hydrogen from a hydrogen-containing gas using the membranes and reactors. The reactors of this invention can be combined with additional reactor systems for direct use of the separated hydrogen.

  5. Stability of separating subsonic boundary layers

    Science.gov (United States)

    Masad, Jamal A.; Nayfeh, Ali H.

    1994-01-01

    The primary and subharmonic instabilities of separating compressible subsonic two-dimensional boundary layers in the presence of a two-dimensional roughness element on a flat plate are investigated. The roughness elements considered are humps and forward- and backward-facing steps. The use of cooling and suction to control these instabilities is studied. The similarities and differences between the instability characteristics of separating boundary layers and those of the boundary layer over a flat plate with a zero pressure gradient are pointed out and discussed. The theoretical results agree qualitatively and quantitatively with the experimental data of Dovgal and Kozlov. Cooling and suction decrease the growth rates of primary and subharmonic waves in the attached-flow regions but increase them in the separated-flow regions.

  6. Experimental studies on transitional separated boundary layers

    OpenAIRE

    Serna Serrano, José

    2013-01-01

    Separated transitional boundary layers appear on key aeronautical processes such as the flow around wings or turbomachinery blades. The aim of this thesis is the study of these flows in representative scenarios of technological applications, gaining knowledge about phenomenology and physical processes that occur there and, developing a simple model for scaling them. To achieve this goal, experimental measurements have been carried out in a low speed facility, ensuring the flow homogeneity and...

  7. Separating a Walkable Environment into Layers

    NARCIS (Netherlands)

    Hillebrand, A.; van den Akker, J.M.; Geraerts, R.J.; Hoogeveen, J.A.

    2016-01-01

    A multi-layered environment is a representation of the walkable environment in a 3D virtual environment that comprises a set of two-dimensional layers together with the locations where the different layers touch, which are called connections. This representation can be used for crowd simulations, e.

  8. Separation of zirconium by thin-layer chromatography.

    Science.gov (United States)

    Oguma, K

    1969-03-01

    The thin-layer Chromatographie separation of a number of metal ions [Sc, Y, Zr, La, Sm, Th, U(VI), etc.] with solvent mixtures of mesityl oxide, ethanol and 5M nitric acid on silica gel-cellulose (5:1) thin-layer plates is reported. Zirconium remains stationary whilst the other metal ions move with the solvent, thus allowing a selective separation of zirconium from about 20 metal ions in ratios ranging from 100:1 to 1:100. Mixtures of various metal ions can also be separated.

  9. Use of quantum dots in aqueous solution to detect blood fingermarks on non-porous surfaces.

    Science.gov (United States)

    Becue, Andy; Moret, Sébastien; Champod, Christophe; Margot, Pierre

    2009-10-30

    A new and original reagent based on the use of highly fluorescent cadmium telluride (CdTe) quantum dots (QDs) in aqueous solution is proposed to detect weak fingermarks in blood on non-porous surfaces. To assess the efficiency of this approach, comparisons were performed with one of the most efficient blood reagents on non-porous surfaces, Acid Yellow 7 (AY7). To this end, four non-porous surfaces were studied, i.e. glass, transparent polypropylene, black polyethylene, and aluminium foil. To evaluate the sensitivity of both reagents, sets of depleted fingermarks were prepared, using the same finger, initially soaked with blood, which was then successively applied on the same surface without recharging it with blood or latent secretions. The successive marks were then cut in halves and the halves treated separately with each reagent. The results showed that QDs were equally efficient to AY7 on glass, polyethylene and polypropylene surfaces, and were superior to AY7 on aluminium. The use of QDs in new, sensitive and highly efficient latent and blood mark detection techniques appears highly promising. Health and safety issues related to the use of cadmium are also discussed. It is suggested that applying QDs in aqueous solution (and not as a dry dusting powder) considerably lowers the toxicity risks.

  10. Streaming effect of wall oscillation to boundary layer separation

    Science.gov (United States)

    Wu, X. H.; Wu, J. Z.; Wu, J. M.

    1991-01-01

    This paper presents a preliminary theoretical result on the time averaged streaming effect of local forcing excitation to the boundary layer separation from smooth surface. The problem is formulated as a periodic disturbance to a basic steady breakaway separating flow, for which the data are taken from a numerical triple-deck solution. The ratio of Strouhal number St and Reynolds number Re plays an important role, both being assumed sufficiently high. The analytical and numerical results show that this streaming effect is quite strong at proper values of St/Re exp 1/4, which may delay or even suppress the separation.

  11. Streaming effect of wall oscillation to boundary layer separation

    Science.gov (United States)

    Wu, X. H.; Wu, J. Z.; Wu, J. M.

    1991-01-01

    This paper presents a preliminary theoretical result on the time averaged streaming effect of local forcing excitation to the boundary layer separation from smooth surface. The problem is formulated as a periodic disturbance to a basic steady breakaway separating flow, for which the data are taken from a numerical triple-deck solution. The ratio of Strouhal number St and Reynolds number Re plays an important role, both being assumed sufficiently high. The analytical and numerical results show that this streaming effect is quite strong at proper values of St/Re exp 1/4, which may delay or even suppress the separation.

  12. Amorphous carbon buffer layers for separating free gallium nitride films

    Science.gov (United States)

    Altakhov, A. S.; Gorbunov, R. I.; Kasharina, L. A.; Latyshev, F. E.; Tarala, V. A.; Shreter, Yu. G.

    2016-11-01

    The possibility of using amorphous diamond-like carbon (DLC) films for self-separation of gallium nitride (GaN) layers grown by hydride vapor-phase epitaxy has been analyzed. DLC films have been synthesized by plasma-enhanced chemical vapor deposition under low pressure on sapphire (Al2O3) substrates with a (0001) crystallographic orientation. The samples have been studied by the methods of Raman scattering and X-ray diffraction analysis. It is shown that thin DLC films affect only slightly the processes of nucleation and growth of gallium nitride films. Notably, the strength of the "GaN film-Al2O3" substrate interface decreases, which facilitates separation of the GaN layers.

  13. Plasmons in spatially separated double-layer graphene nanoribbons

    Science.gov (United States)

    Bagheri, Mehran; Bahrami, Mousa

    2014-05-01

    Motivated by innovative progresses in designing multi-layer graphene nanostructured materials in the laboratory, we theoretically investigate the Dirac plasmon modes of a spatially separated double-layer graphene nanoribbon system, made up of a vertically offset armchair and metallic graphene nanoribbon pair. We find striking features of the collective excitations in this novel Coulomb correlated system, where both nanoribbons are supposed to be either intrinsic (undoped/ungated) or extrinsic (doped/gated). In the former, it is shown the low-energy acoustical and the high-energy optical plasmon modes are tunable only by the inter-ribbon charge separation. In the later, the aforementioned plasmon branches are modified by the added doping factor. As a result, our model could be useful to examine the existence of a linear Landau-undamped low-energy acoustical plasmon mode tuned via the inter-ribbon charge separation as well as doping. This study might also be utilized for devising novel quantum optical waveguides based on the Coulomb coupled graphene nanoribbons.

  14. Polymer coatings as separator layers for microbial fuel cell cathodes

    KAUST Repository

    Watson, Valerie J.

    2011-03-01

    Membrane separators reduce oxygen flux from the cathode into the anolyte in microbial fuel cells (MFCs), but water accumulation and pH gradients between the separator and cathode reduces performance. Air cathodes were spray-coated (water-facing side) with anion exchange, cation exchange, and neutral polymer coatings of different thicknesses to incorporate the separator into the cathode. The anion exchange polymer coating resulted in greater power density (1167 ± 135 mW m-2) than a cation exchange coating (439 ± 2 mW m-2). This power output was similar to that produced by a Nafion-coated cathode (1114 ± 174 mW m-2), and slightly lower than the uncoated cathode (1384 ± 82 mW m-2). Thicker coatings reduced oxygen diffusion into the electrolyte and increased coulombic efficiency (CE = 56-64%) relative to an uncoated cathode (29 ± 8%), but decreased power production (255-574 mW m-2). Electrochemical characterization of the cathodes ex situ to the MFC showed that the cathodes with the lowest charge transfer resistance and the highest oxygen reduction activity produced the most power in MFC tests. The results on hydrophilic cathode separator layers revealed a trade off between power and CE. Cathodes coated with a thin coating of anion exchange polymer show promise for controlling oxygen transfer while minimally affecting power production. © 2010 Elsevier B.V. All rights reserved.

  15. Small particle reagent based on crystal violet dye for developing latent fingerprints on non-porous wet surfaces

    Directory of Open Access Journals (Sweden)

    Richa Rohatgi

    2015-12-01

    Full Text Available Small particle reagent (SPR is a widely used method for developing latent fingerprints on non-porous wet surfaces. SPR based on zinc carbonate hydroxide monohydrate, ZnCo3·2Zn(OH2·H2O – also called basic zinc carbonate – has been formulated. The other ingredients of the formulation are crystal violet dye and a commercial liquid detergent. The composition develops clear, sharp and detailed fingerprints on non-porous items, after these were immersed separately in clean and dirty water for variable periods of time. The ability of the present formulation to detect weak and faint chance prints not only enhances its utility, but also its potentiality in forensic case work investigations. The raw materials used to prepare the SPR are cost-effective and non-hazardous.

  16. Wall-layer model for LES with massive separation

    Science.gov (United States)

    Fakhari, Ahmad; Armenio, Vincenzo; Roman, Federico

    2016-11-01

    Currently, Wall Functions (WF) work well under specific conditions, mostly exhibit drawbacks specially in flows with separation beyond curvatures. In this work, we propose a more general WF which works well in attached and detached flows, in presence and absence of Immersed Boundaries (IB). First we modified an equilibrium stress WF for boundary-fitted geometry making dynamic the computation of the k (von Karman constant) of the log-law; the model was first applied to a periodic open channel flow, and then to the flow over a 2D single hill using uniform coarse grids; the model captured separation with reasonable accuracy. Thereafter IB Method by Roman et al. was improved to avoid momentum loss at the interface between the fluid-solid regions. This required calibration of interfacial eddy viscosity; also a random stochastic forcing was used in wall-normal direction to increase Reynolds stresses and improve mean velocity profile. Finally, to reproduce flow separation, a simplified boundary layer equation was applied to construct velocity at near wall computational nodes. The new scheme was tested on the 2D single hill and periodic hills applying Cartesian and curvilinear grids; good agreement with references was obtained with reduction in cost and complexity. Financial support from project COSMO "CFD open source per opera morta" PAR FSC 2007-2013, Friuli Venezia Giulia.

  17. Mixed mosaic membranes prepared by layer-by-layer assembly for ionic separations.

    Science.gov (United States)

    Rajesh, Sahadevan; Yan, Yu; Chang, Hsueh-Chia; Gao, Haifeng; Phillip, William A

    2014-12-23

    Charge mosaic membranes, which possess distinct cationic and anionic domains that traverse the membrane thickness, are capable of selectively separating dissolved salts from similarly sized neutral solutes. Here, the generation of charge mosaic membranes using facile layer-by-layer assembly methodologies is reported. Polymeric nanotubes with pore walls lined by positively charged polyethylenimine moieties or negatively charged poly(styrenesulfonate) moieties were prepared via layer-by-layer assembly using track-etched membranes as sacrificial templates. Subsequently, both types of nanotubes were deposited on a porous support in order to produce mixed mosaic membranes. Scanning electron microscopy demonstrates that the facile deposition techniques implemented result in nanotubes that are vertically aligned without overlap between adjacent elements. Furthermore, the nanotubes span the thickness of the mixed mosaic membranes. The effects of this unique nanostructure are reflected in the transport characteristics of the mixed mosaic membranes. The hydraulic permeability of the mixed mosaic membranes in piezodialysis operations was 8 L m(-2) h(-1) bar(-1). Importantly, solute rejection experiments demonstrate that the mixed mosaic membranes are more permeable to ionic solutes than similarly sized neutral molecules. In particular, negative rejection of sodium chloride is observed (i.e., the concentration of NaCl in the solution that permeates through a mixed mosaic membrane is higher than in the initial feed solution). These properties illustrate the ability of mixed mosaic membranes to permeate dissolved ions selectively without violating electroneutrality and suggest their utility in ionic separations.

  18. Comparison of several methods for predicting separation in a compressible turbulent boundary layer

    Science.gov (United States)

    Gerhart, P. M.; Bober, L. J.

    1974-01-01

    Several methods for predicting the separation point for a compressible turbulent boundary layer were applied to the flow over a bump on a wind-tunnel wall. Measured pressure distributions were used as input. Two integral boundary-layer methods, three finite-difference boundary-layer methods, and three simple methods were applied at five free-stream Mach numbers ranging from 0.354 to 0.7325. Each of the boundary-layer methods failed to explicitly predict separation. However, by relaxing the theoretical separation criteria, several boundary-layer methods were made to yield reasonable separation predictions, but none of the methods accurately predicted the important boundary-layer parameters at separation. Only one of the simple methods consistently predicted separation with reasonable accuracy in a manner consistent with the theory. The other methods either indicated several possible separation locations or only sometimes predicted separation.

  19. Sticking of molecules on non-porous amorphous water ice

    CERN Document Server

    He, Jiao; Vidali, Gianfranco

    2016-01-01

    Accurate modeling of physical and chemical processes in the interstellar medium requires detailed knowledge of how atoms and molecule adsorb on dust grains. However, the sticking coefficient, a number between 0 and 1 that measures the first step in the interaction of a particle with a surface, is usually assumed in simulations of ISM environments to be either 0.5 or 1. Here we report on the determination of the sticking coefficient of H$_2$, D$_2$, N$_2$, O$_2$, CO, CH$_4$, and CO$_2$ on non-porous amorphous solid water (np-ASW). The sticking coefficient was measured over a wide range of surface temperatures using a highly collimated molecular beam. We showed that the standard way of measuring the sticking coefficient --- the King-Wells method --- leads to the underestimation of trapping events in which there is incomplete energy accommodation of the molecule on the surface. Surface scattering experiments with the use of a pulsed molecular beam are used instead to measure the sticking coefficient. Based on th...

  20. Integration Process Development for Improved Compatibility with Organic Non-Porous Ultralow-k Dielectric Fluorocarbon on Advanced Cu Interconnects

    Science.gov (United States)

    Gu, Xun; Tomita, Yugo; Nemoto, Takenao; Miyatani, Kotaro; Saito, Akane; Kobayashi, Yasuo; Teramoto, Akinobu; Kuroda, Rihito; Kuroki, Shin-Ichiro; Kawase, Kazumasa; Nozawa, Toshihisa; Matsuoka, Takaaki; Sugawa, Shigetoshi; Ohmi, Tadahiro

    2012-05-01

    Integration of an organic non-porous ultralow-k dielectric, fluorocarbon (k= 2.2), into advanced Cu interconnects was demonstrated. The challenges of process-induced damage, such as delamination and variances of both the structure and electrical properties of the fluorocarbon during fabrication, were investigated on Cu/fluorocarbon damascene interconnects. A titanium-based barrier layer, instead of a tantalum-based barrier layer, was used to avoid delamination between Cu and fluorocarbon in Cu/fluorocarbon interconnects. A moisture-hermetic dielectric protective layer was also effective to avoid damage induced by wet chemical cleaning. On the other hand, a post-etching nitrogen plasma treatment to form a stable protective layer on the surface of the fluorocarbon was proposed for the practical minimization of damage introduction to fluorocarbon in the following damascene process, such as post-etching cleaning.

  1. Membranes having aligned 1-D nanoparticles in a matrix layer for improved fluid separation

    Energy Technology Data Exchange (ETDEWEB)

    Revanur, Ravindra; Lulevich, Valentin; Roh, Il Juhn; Klare, Jennifer E.; Kim, Sangil; Noy, Aleksandr; Bakajin, Olgica

    2015-12-22

    Membranes for fluid separation are disclosed. These membranes have a matrix layer sandwiched between an active layer and a porous support layer. The matrix layer includes 1-D nanoparticles that are vertically aligned in a porous polymer matrix, and which substantially extend through the matrix layer. The active layer provides species-specific transport, while the support layer provides mechanical support. A matrix layer of this type has favorable surface morphology for forming the active layer. Furthermore, the pores that form in the matrix layer tend to be smaller and more evenly distributed as a result of the presence of aligned 1-D nanoparticles. Improved performance of separation membranes of this type is attributed to these effects.

  2. Decomposition Methods For a Piv Data Analysis with Application to a Boundary Layer Separation Dynamics

    Directory of Open Access Journals (Sweden)

    Václav URUBA

    2010-12-01

    Full Text Available Separation of the turbulent boundary layer (BL on a flat plate under adverse pressure gradient was studied experimentally using Time-Resolved PIV technique. The results of spatio-temporal analysis of flow-field in the separation zone are presented. For this purpose, the POD (Proper Orthogonal Decomposition and its extension BOD (Bi-Orthogonal Decomposition techniques are applied as well as dynamical approach based on POPs (Principal Oscillation Patterns method. The study contributes to understanding physical mechanisms of a boundary layer separation process. The acquired information could be used to improve strategies of a boundary layer separation control.

  3. Mechanically durable, superoleophobic coatings prepared by layer-by-layer technique for anti-smudge and oil-water separation

    OpenAIRE

    Philip S. Brown; Bhushan, Bharat

    2015-01-01

    Superoleophobic surfaces are of interest for anti-fouling, self-cleaning, anti-smudge, low-drag, anti-fog, and oil-water separation applications. Current bioinspired surfaces are of limited use due to a lack of mechanical durability. A so-called layer-by-layer approach, involving charged species with electrostatic interactions between layers, can provide the flexibility needed to improve adhesion to the substrate while providing a low surface tension coating at the air interface. In this work...

  4. Software Based Traffic Separation at the Access Layer

    Directory of Open Access Journals (Sweden)

    Yona Andegelile

    2014-07-01

    Full Text Available Access Network is the subscriber part of the telecommunications network or the network connecting the subscribers to the Internet Service Providers (ISP [1]. In many countries including Tanzania access network is still predominantly made up of the copper cable based or other point to point wireless connections. This has kept the network in large proportions passive, inflexible and relatively unreliable [2]. This traditional network has long been tailored to the services generally provided i.e. voice, leased lines, Internet, corporate data and video conference, sometimes each provided by separate equipment and networks. This paper presents the study on approaches used by ISP in Tanzania to separate traffic in the access network. The paper also presents the effective way of traffic separation, whereby multiple hardware used to separate traffic currently has been replaced with single hardware. The traffic separation technique is based on creating logical links (software based for each traffic type inside single physical link, providing a differentiated QoS support for each type of traffic according to its individual QoS requirements.

  5. Development of Techniques for Separating Waterproof Layer from XLPE Cable Sheath by Hot Water Heating

    Science.gov (United States)

    Okazaki, Masato; Nakade, Masahiko; Okashita, Minoru; Tanimoto, Mihoko

    Waterproof layer is used to prevent penetration of water which is one of the factors of dielectric breakdown in XLPE cables more than 66kV class. A XLPE cable sheath with waterproof layer is done landfill disposal as industrial waste because separation of waterproof layer is difficult for technology and cost. However, around 20 years passes after waterproof layer was introduced, and social consciousness for environment changes during these 20 years, and responsibility of company for environment of a society grows bigger. We report the result that examined techniques for separating waterproof layer.

  6. On Pattern Separating Function in a Two-Layered Random Nerve Net with Feedforward Inhibitory Connections

    Institute of Scientific and Technical Information of China (English)

    ToyoshiTorioka; 汪嘉业

    1989-01-01

    In this paper, we derive a theory for investigating the pattern separating function in the nerve net. Then, we consider some effects of the stochastic parameters constructing the nerve net, firing rates of the second layer and input patterns on the pattern separating faction through the theory. As a result ,we reveal that a nerve net excellent in pattern separating fuuction is obtained when the stochastic parameters are selected properly . We also shew that the pattern separating function is enhanced by controlling the firing rate of the second layer to a small value. Furthermore, the input patterns are separated large|y when the firing rates of them are latge.

  7. The calculation of incompressible separated turbulent boundary layers

    Science.gov (United States)

    Kogan, A.; Migemi, S.

    1990-02-01

    The algebraic turbulent model of Baldwin-Lomax was incorporated into the incompressible Navier-Stokes code FIDAP. This model has been extensively tested in the past in finite difference codes. We believe that the incorporation of the model into the finite element code also has resulted in a practical method to compute a variety of separated turbulent two-dimensional flows. Firstly, the model is used to compute the attached flow about an airfoil. Next, the application of the model to separated flows is presented, by computing the flows at high angles of attack up to maximum lift. It is shown that the model is capable of predicting separation, steady stall and C(sub L MAX). As a difficult test of the model, we compute the laminar separation bubble development directly, using the full Navier-Stokes finite elements code. As far as we know, this approach has not been reported previously. The importance of using an appropriate upwinding is discussed. When possible, comparison of computed results with experiments is presented and the agreement is good.

  8. Identification of separate flow features in the shear layer

    Science.gov (United States)

    Mulleners, Karen; Krishna, Swathi; Green, Melissa

    2016-11-01

    Analyzing unsteady flow fields primarily involves the identification of dynamically significant regions of vorticity in the flow. Detection of all the flow features is essential for an accurate description of the physics of the flow, which eventually helps in improving flow modeling and predictions. Eulerian criteria such as λ2 and Γ2 successfully identify large scale structures based on local velocity gradients and topology but do not detect the coherent vortices with the concentrated vorticity in a shear layer. The identification of these smaller structures within the shear layer is important when predicting the overall circulatory contribution to the aerodynamic forces produced, in applications such as flapping wing design. In order to detect the smaller flow features along with the prominent large scale vortices, an alternative method of vortex identification is proposed in which the flow structures are detected based on the vorticity contours. This method is applied to numerical and experimental data of a pitching panel to highlight its robustness. In addition, the finite time Lyapunov exponent (FTLE) is calculated to show that the boundaries of the material lines and identified vorticity contours coincide.

  9. On Pattern Separating Function in a Two-Layered Random Nerve Net with Feedforward Inhibitory Connections

    Institute of Scientific and Technical Information of China (English)

    ToyoshiTorioka; 汪嘉业

    1989-01-01

    In this paper,we derive a theory for investigating the pattern separating function in the nerve net ,then,we consider some effects of the stochastic parameters constructing the nerve net,firing rates of the second layer and input patterns on the pattern separating function through the stochastic parameters are selected proerly.we also show that the pattern separating function is enhanced by controlling the firing rate of the second layer to a small value.Furthermore,the input patterns are separated largely when the firing rates of them are large.

  10. Turbulent Heat Transfer Characteristics in the Shear Layer of a Separated Flow

    Science.gov (United States)

    Jovic, S.; Kutler, Paul F. (Technical Monitor)

    1994-01-01

    Experiments were performed to study the evolution of the heat transfer structure in a separated free shear layer region of an incompressible separated turbulent boundary layer flow behind a backward-facing step. While there is an abundance of velocity field measurements of separated flows, heat transfer measurements are rather scarce, thus limiting assessment of the heat transfer physics and its accurate modeling. The purpose of the paper is twofold: to improve an understanding of effects of flow separation on heat transfer characteristics, and to provide data for turbulence modeling and computation. The boundary layer upstream of the step was turbulent and fully developed. A constant temperature surface boundary condition was imposed upstream and downstream of the step for the heat transfer study. An internal mixing-layer like flow forms and grows from the step lip within the original boundary layer. The turbulent structure of the flow evolving downstream, however, does not switch immediately to that of a mixing layer over the entire shear layer thickness. Measurements of mean and fluctuating velocity and temperature fields indicate that the internal layer spreads gradually in the transverse direction while the outer part of the original boundary layer is effectively unperturbed. The results in this paper have not been previously reported.

  11. Metal separators coated with carbon/resin composite layers for PEFCs

    Energy Technology Data Exchange (ETDEWEB)

    Kitta, Shigehiro [Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4 Takeda, Kofu 400-8510 (Japan); Asktechnica Corp., 1488 Ichikawadaimon, Nishi-yatsushiro 409-3601 (Japan); Uchida, Hiroyuki [Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4 Takeda, Kofu 400-8510 (Japan); Watanabe, Masahiro [Clean Energy Research Center, University of Yamanashi, 4 Takeda, Kofu 400-8510 (Japan)

    2007-12-31

    A new type of metal separator coated with corrosion-resistant and electronically conductive carbon/resin composite layers has been developed. A flat, stainless steel plate was coated with a thin composite layer, and then ribs were formed of a similar composite over the thin layer as gas flow channels. The composite consisted of graphite, epoxy resin and a phenol hardener. By optimizing the combination and composition of materials, target values for the bulk electric conductivity and the chemical stability in hot water were cleared. The separator pieces exhibited a good corrosion resistance during soaking tests in 0.1 M H{sub 2}SO{sub 4} at 90 C over 2000 h or even at 120 C over 1200 h. The area-specific resistance of the separator coated with the thin protecting layer and the rib layer was less than 13.8 m{omega} cm{sup 2}. (author)

  12. Mechanically durable, superoleophobic coatings prepared by layer-by-layer technique for anti-smudge and oil-water separation

    Science.gov (United States)

    Brown, Philip S.; Bhushan, Bharat

    2015-03-01

    Superoleophobic surfaces are of interest for anti-fouling, self-cleaning, anti-smudge, low-drag, anti-fog, and oil-water separation applications. Current bioinspired surfaces are of limited use due to a lack of mechanical durability. A so-called layer-by-layer approach, involving charged species with electrostatic interactions between layers, can provide the flexibility needed to improve adhesion to the substrate while providing a low surface tension coating at the air interface. In this work, a polyelectrolyte binder, SiO2 nanoparticles, and a fluorosurfactant are spray deposited separately to create a durable, superoleophobic coating. Polydiallyldimethylammonium chloride (PDDA) polyelectrolyte was complexed with a fluorosurfactant layer (FL), which provides oil repellency while being hydrophilic. This oleophobic/superhydrophilic behavior was enhanced through the use of roughening with SiO2 particles resulting in a superoleophobic coating with hexadecane contact angles exceeding 155° and tilt angles of less than 4°. The coating is also superhydrophilic, which is desirable for oil-water separation applications. The durability of these coatings was examined through the use of micro- and macrowear experiments. These coatings currently display characteristics of transparency. Fabrication of these coatings via the layer-by-layer technique results in superoleophobic surfaces displaying improved durability compared to existing work where either the durability or the oil-repellency is compromised.

  13. Mechanically durable, superoleophobic coatings prepared by layer-by-layer technique for anti-smudge and oil-water separation

    Science.gov (United States)

    Brown, Philip S.; Bhushan, Bharat

    2015-01-01

    Superoleophobic surfaces are of interest for anti-fouling, self-cleaning, anti-smudge, low-drag, anti-fog, and oil-water separation applications. Current bioinspired surfaces are of limited use due to a lack of mechanical durability. A so-called layer-by-layer approach, involving charged species with electrostatic interactions between layers, can provide the flexibility needed to improve adhesion to the substrate while providing a low surface tension coating at the air interface. In this work, a polyelectrolyte binder, SiO2 nanoparticles, and a fluorosurfactant are spray deposited separately to create a durable, superoleophobic coating. Polydiallyldimethylammonium chloride (PDDA) polyelectrolyte was complexed with a fluorosurfactant layer (FL), which provides oil repellency while being hydrophilic. This oleophobic/superhydrophilic behavior was enhanced through the use of roughening with SiO2 particles resulting in a superoleophobic coating with hexadecane contact angles exceeding 155° and tilt angles of less than 4°. The coating is also superhydrophilic, which is desirable for oil-water separation applications. The durability of these coatings was examined through the use of micro- and macrowear experiments. These coatings currently display characteristics of transparency. Fabrication of these coatings via the layer-by-layer technique results in superoleophobic surfaces displaying improved durability compared to existing work where either the durability or the oil-repellency is compromised. PMID:25731716

  14. Enhancement of capillary electrochromatographic separation performance by conductive polymer in a layer-by-layer fabricated graphene stationary phase.

    Science.gov (United States)

    Zhang, Juan; Zhang, Wenpeng; Bao, Tao; Chen, Zilin

    2014-04-25

    In this work, we fabricated a novel graphene-based capillary column for open-tubular capillary electrochromatography (OT-CEC) by a layer-by-layer strategy. To immobilize graphene onto the inner surface of silica capillary, a bio-inspired method was first used to functionalize the capillary surface with a layer of polydopamine (PDA). Graphene oxide (GO) was then introduced and can covalently react with polydopamine, realizing immobilization of graphene as a result. To enhance the modification efficiency of polydopamine, a conductive polymer, polyaniline (PANI) was introduced to be a sub-layer; polydopamine was then introduced following with GO, to generate a multilayer GO-PDA-PANI@capillary. Interestingly, separation efficiency of the graphene-based capillary was enhanced significantly by using conductive PANI as a sub-layer. The morphology of different layers modified on the capillary column was characterized by scanning electron microscopy (SEM). The electroosmotic flow (EOF) characteristics of capillaries modified with different layers were also investigated by varying the pH value of mobile phase. GO-PDA-PANI@capillary showed good separation efficiency towards alkylbenzenes by OT-CEC mode, with theoretic plate numbers up to 133,918 for benzene. The separation was found to follow a reversed-phase chromatographic retention mechanism. Repeatability of the GO-PDA-PANI@capillary was studied, with relative standard deviations for intra-day and inter-day runs less than 2.89%, and column-to-column runs less than 6.17%. The separation performance of GO-PDA-PANI@capillary was also compared with that of the reported graphene modified capillary.

  15. Development of optimized mobile phases for protein separation by high performance thin layer chromatography.

    Science.gov (United States)

    Biller, Julia; Morschheuser, Lena; Riedner, Maria; Rohn, Sascha

    2015-10-09

    In recent years, protein chemistry tends inexorably toward the analysis of more complex proteins, proteoforms, and posttranslational protein modifications. Although mass spectrometry developed quite fast correspondingly, sample preparation and separation of these analytes is still a major issue and quite challenging. For many years, electrophoresis seemed to be the method of choice; nonetheless its variance is limited to parameters such as size and charge. When taking a look at traditional (thin-layer) chromatography, further parameters such as polarity and different mobile and stationary phases can be utilized. Further, possibilities of detection are manifold compared to electrophoresis. Similarly, two-dimensional separation can be also performed with thin-layer chromatography (TLC). As the revival of TLC developed enormously in the last decade, it seems to be also an alternative to use high performance thin-layer chromatography (HPTLC) for the separation of proteins. The aim of this study was to establish an HPTLC separation system that allows a separation of protein mixtures over a broad polarity range, or if necessary allowing to modify the separation with only few steps to improve the separation for a specific scope. Several layers and solvent systems have been evaluated to reach a fully utilized and optimized separation system. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Unsteady separated boundary layer in a transonic diffuser flow with self-excited oscillations

    Science.gov (United States)

    Hsieh, T.; Coakley, T. J.

    1986-01-01

    A numerical investigation of two-dimensional unsteady boundary layer in a transonic diffuser flow with self-excited oscillations and strong flow separation by solving the compressible, Reynolds-averaged, thin-layer Navier-Stokes equations with two-equations turbulence model is described. Three different meshes with constant streamwise mesh distribution and varying vertical mesh distribution were used. Results obtained indicate that a refinement of mesh studied here has minimal effect on the mean boundary layer flow but significantly increases the amplitude of oscillation of all flow variables. Comparisons of unsteady wall pressure, velocity profile, terminal shock, and separation pocket among computations and with experiment are presented.

  17. Solving Nonlinearly Separable Classifications in a Single-Layer Neural Network.

    Science.gov (United States)

    Conaway, Nolan; Kurtz, Kenneth J

    2017-03-01

    Since the work of Minsky and Papert ( 1969 ), it has been understood that single-layer neural networks cannot solve nonlinearly separable classifications (i.e., XOR). We describe and test a novel divergent autoassociative architecture capable of solving nonlinearly separable classifications with a single layer of weights. The proposed network consists of class-specific linear autoassociators. The power of the model comes from treating classification problems as within-class feature prediction rather than directly optimizing a discriminant function. We show unprecedented learning capabilities for a simple, single-layer network (i.e., solving XOR) and demonstrate that the famous limitation in acquiring nonlinearly separable problems is not just about the need for a hidden layer; it is about the choice between directly predicting classes or learning to classify indirectly by predicting features.

  18. Enhancing the separation performance by introducing bioadhesive bonding layer in composite pervaporation membranes for ethanol dehydration

    Institute of Scientific and Technical Information of China (English)

    Hong Wu; Tiantian Zhou; Xianshi Li; Cuihong Zhao; Zhongyi Jiang

    2015-01-01

    A high performance composite membrane was prepared under the inspiration of bioadhesion principles for pervaporative dehydration of ethanol. Chitosan (CS) and polyacrylonitrile (PAN) ultrafiltration membranes were used as the active layer and the support layer, respectively. Guar gum (GG), a natural bioadhesive, was in-troduced as the intermediate bonding layer to improve the separation performance and stability of the fabricated CS/GG/PAN composite membranes. The contact angle of the GG layer was just between those of the CS layer and the PAN layer, minimizing the difference of hydrophilicity between the active layer and the support layer. The peeling strength of the composite membrane was significantly enhanced after the introduction of the GG layer. The effects of preparation conditions and operation conditions including GG concentration, operating tempera-ture and ethanol concentration in feed on the pervaporation performance were investigated. The as-fabricated CS/GG/PAN composite membrane showed the optimum performance with a permeation flux of up to 804 g·m−2·h−1 and a separation factor higher than 1900. Besides, the composite membranes exhibited a desir-able long-term operational stability.

  19. Application of DDES and IDDES with shear layer adapted subgrid length-scale to separated flows

    Science.gov (United States)

    Guseva, E. K.; Garbaruk, A. V.; Strelets, M. Kh

    2016-11-01

    A comparative study is conducted of the original versions of Delayed Detached- Eddy Simulation (DDES) and Improved DDES (IDDES) and these approaches combined with “shear-layer-adapted” (SLA) subgrid length-scale proposed recently for resolving the issue of delayed RANS-to-LES transition in separated shear layers in global hybrid RANS-LES approaches. Computations were carried out of two separated flows: a transonic flow past M 219 cavity and a subsonic flow over NASA wall mounted hump. Results of the computations suggest that the use of the SLA subgrid length-scale considerably accelerates transition to resolved three-dimensional turbulence in the separated shear layers and substantially improves agreement with the experimental data.

  20. Chromatographic separation of inorganic ions on thin layers of titanium phosphate ion-exchanger.

    Science.gov (United States)

    Ghoulipour, Vanik; Safari, Moharram

    2014-12-01

    The chromatographic behavior of 30 inorganic cations has been studied on thin layers of titanium phosphate ion-exchanger using several aqueous, organic and mixed mobile phases. The separation of one ion from several other ions and also ternary and binary separations have been developed. Some important analytical separations are reported. The effect of pH of the mobile phase on retention factor (Rf) values of the cations in the presence of complex-forming anion along with the separation power of the ion-exchanger were studied. This ion-exchanger exhibits high sorption capacity and varying selectivity towards metal ions and makes it a suitable stationaiy phase in thin layer chromatography.

  1. Chromatographic separation of inorganic ions on thin layers of titanium phosphate ion-exchanger

    Institute of Scientific and Technical Information of China (English)

    Vanik GHOULIPOUR; Moharram SAFARI

    2014-01-01

    The chromatographic behavior of 30 inorganic cations has been studied on thin layers of titanium phosphate ion-exchanger using several aqueous,organic and mixed mobile phases. The separation of one ion from several other ions and also ternary and binary separations have been developed. Some important analytical separations are reported. The effect of pH of the mobile phase on retention factor(Rf)values of the cations in the presence of complex-forming anion along with the separation power of the ion-exchanger were studied. This ion-exchanger exhibits high sorption capacity and varying selectivity towards metal ions and makes it a suitable stationary phase in thin layer chromatography.

  2. Determination of optimal source-detector separation in measuring chromophores in layered tissue with diffuse reflectance

    Institute of Scientific and Technical Information of China (English)

    Yunhan Luo; Houxin Cui; Xiaoyu Gu; Rong Liu; Kexin Xu

    2005-01-01

    Based on analysis of the relation between mean penetration depth and source-detector separation in a threelayer model with the method of Monte-Carlo simulation, an optimal source-detector separation is derived from the mean penetration depth referring to monitoring the change of chromophores concentration of the sandwiched layer. In order to verify the separation, we perform Monte-Carlo simulations with varied absorption coefficient of the sandwiched layer. All these diffuse reflectances are used to construct a calibration model with the method of partial least square (PLS). High correlation coefficients and low root mean square error of prediction (RMSEP) at the optimal separation have confirmed correctness of the selection. This technique is expected to show light on noninvasive diagnosis of near-infrared spectroscopy.

  3. Modifications of the law of the wall and algebraic turbulence modelling for separated boundary layers

    Science.gov (United States)

    Baldwin, B. S.; Maccormack, R. W.

    1976-01-01

    Various modifications of the conventional algebraic eddy viscosity turbulence model are investigated for application to separated flows. Friction velocity is defined in a way that avoids singular behavior at separation and reattachment but reverts to the conventional definition for flows with small pressure gradients. This leads to a modified law of the wall for separated flows. The effect on the calculated flow field of changes in the model that affect the eddy viscosity at various distances from the wall are determined by (1) switching from Prandtl's form to an inner layer formula due to Clauser at various distances from the wall, (2) varying the constant in the Van Driest damping factor, (3) using Clauser's inner layer formula all the way to the wall, and (4) applying a relaxation procedure in the evaluation of the constant in Clauser's inner layer formula. Numerical solutions of the compressible Navier-Stokes equations are used to determine the effects of the modifications. Experimental results from shock-induced separated flows at Mach numbers 2.93 and 8.45 are used for comparison. For these cases improved predictions of wall pressure distribution and positions of separation and reattachment are obtained from the relaxation version of the Clauser inner layer eddy viscosity formula.

  4. Enhanced charge separation and oxidation kinetics of BiVO4 photoanode by double layer structure

    Science.gov (United States)

    Yang, Lin; Xiong, Yuli; Dong, Hongmei; Peng, Huarong; Zhang, Yunhuai; Xiao, Peng

    2017-03-01

    Monoclinic bismuth vanadate (BiVO4) is a promising semiconductor for photoelectrochemical water splitting. Here, we developed a facile fabrication of BiVO4 double layer photoanode on the fluorine-doped tin oxide substrate by electrodeposition. The BiVO4 double layer photoanode is composed by a dense BiVO4 film as the inner layer and a nanoporous BiVO4 film as the outer layer. Compared to the BiVO4 single layer photoanode, the optimized BiVO4 double layer photoanode produced a much higher photocurrent of 1.15 mA/cm2 at 0.6 V vs. Ag/AgCl under AM 1.5G (100 mW/cm2) illumination. The results of the photoelectric conversion kinetics for different samples revealed that the charge separation and oxidation kinetics efficiencies for the BiVO4 double layer are 47.2% and 51.6% at 0.6 V vs. Ag/AgCl, while the values for BiVO4 single layer are 32.3% and 35.8%, respectively. The improved photoelectrochemical performance for BiVO4 double layer is mainly ascribed to the decrease of defect state at the interface after inserting a dense BiVO4 as an inner layer to prevent the recombination of photogenerated electron-hole pairs.

  5. Separation attenuation in swept shock wave-boundary-layer interactions using different microvortex generator geometries

    Science.gov (United States)

    Martis, R. R.; Misra, A.

    2017-03-01

    A numerical study is conducted to determine the effectiveness of six different microvortex generator geometries in controlling swept shock wave/boundary-layer interactions. The geometries considered are base ramp, base ramp with declining angle of 45°, blunt ramp, split ramp, thick vanes, and ramped vanes. Microvortex generators with a gap were found to be better suited for delaying the separation. Thick vanes showed the largest delay in separation among the devices studied.

  6. Separation attenuation in swept shock wave-boundary-layer interactions using different microvortex generator geometries

    Science.gov (United States)

    Martis, R. R.; Misra, A.

    2017-09-01

    A numerical study is conducted to determine the effectiveness of six different microvortex generator geometries in controlling swept shock wave/boundary-layer interactions. The geometries considered are base ramp, base ramp with declining angle of 45°, blunt ramp, split ramp, thick vanes, and ramped vanes. Microvortex generators with a gap were found to be better suited for delaying the separation. Thick vanes showed the largest delay in separation among the devices studied.

  7. Thin-layer Chromatographic (TLC) Separations and Bioassays of Plant Extracts to Identify Antimicrobial Compounds

    OpenAIRE

    Kagan, Isabelle A.; Flythe, Michael D.

    2014-01-01

    A common screen for plant antimicrobial compounds consists of separating plant extracts by paper or thin-layer chromatography (PC or TLC), exposing the chromatograms to microbial suspensions (e.g. fungi or bacteria in broth or agar), allowing time for the microbes to grow in a humid environment, and visualizing zones with no microbial growth. The effectiveness of this screening method, known as bioautography, depends on both the quality of the chromatographic separation and the care taken wit...

  8. Thin-layer chromatographie separation of alkaline earth metals on diethylaminoethyl cellulose.

    Science.gov (United States)

    Ishida, K

    1969-12-01

    Thin-layer Chromatographic behaviour of magnesium, calcium, strontium and barium on diethylaminoethyl cellulose has been investigated in methanol-nitric acid mixtures. R(f) values are in the order magnesium > calcium > strontium > barium. The differences in R(f) values are large enough to allow good separations of the four metal ions from each other. The best separation is obtained by the ascending technique with methanol-8M nitric acid (20:1, v v ).

  9. Polymeric molecular sieve membranes for gas separation

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Sheng; Qiao, Zhenan; Chai, Songhai

    2017-08-15

    A porous polymer membrane useful in gas separation, the porous polymer membrane comprising a polymeric structure having crosslinked aromatic groups and a hierarchical porosity in which micropores having a pore size less than 2 nm are present at least in an outer layer of the porous polymer membrane, and macropores having a pore size of over 50 nm are present at least in an inner layer of the porous polymer membrane. Also described are methods for producing the porous polymer membrane in which a non-porous polymer membrane containing aromatic rings is subjected to a Friedel-Crafts crosslinking reaction in which a crosslinking molecule crosslinks the aromatic rings in the presence of a Friedel-Crafts catalyst and organic solvent under sufficiently elevated temperature, as well as methods for using the porous polymer membranes for gas or liquid separation, filtration, or purification.

  10. Numerical study and control method of interaction of nucleation and boundary layer separation in condensing flow

    Institute of Scientific and Technical Information of China (English)

    Liansuo AN; Zhi WANG; Zhonghe HAN

    2009-01-01

    The spontaneous nucleation flow in turbine cascade was numerically studied. The model was imple-mented within a full Navier-Stokes viscous flow solution procedure and the process of condensation was calculated by the quadrature method of moments that shows good accuracy with very broad size distributions.Results were presented for viscous and inviscous flow,showing the influence of boundary layer separation and wake vortices on spontaneous nucleation. The results show that the degree of flow separation in wet steam flow is greater than that in superheated steam flow due to condensation shock and that the loss cannot be neglected.Furthermore, the impact of boundary layer separation and wake vortices on velocity profiles and its implications for profile loss were considered. The calculations showed that layer separation and wake vortices influence nucleation rate, leading to different droplet distributions. A method for controlling homogeneous nucleation and for reducing degree of flow separation in high-speed transonic wet steam flow was presented. The liquid phase parameter distribution is sensitive to the suction side profile of turbine cascade, which impacts the nucleation rate distribution leading to different droplet distributions and affects the degree of flow separation. The numerical study provides a practical design method for turbine blade to reduce wetness losses.

  11. Charge separation in contact systems with CdSe quantum dot layers

    Energy Technology Data Exchange (ETDEWEB)

    Zillner, Elisabeth Franziska

    2013-03-06

    Quantum dot (QD) solar cells are a fast developing area in the field of solution processed photovoltaics. Central aspects for the application of QDs in solar cells are separation and transport of charge carriers in the QD layers and the formation of charge selective contacts. Even though efficiencies of up to 7% were reached in QD solar cells, these processes are not yet fully understood. In this thesis the mechanisms of charge separation, transport and recombination in CdSe QD layers and layer systems were studied. Charge separation was measured via surface photovoltage (SPV) at CdSe QD layers with thicknesses in the range of monolayers. To determine the influence of interparticle distance of QDs and trap states on the surface of QDs on charge separation, QDs with four different surfactant layers were studied. Layers of CdSe QDs were prepared on ITO, Si, SiO{sub 2} and CdS by dip coating under inert atmosphere. The layers were characterized by Rutherford backscattering spectrometry, UV-vis spectroscopy, step profilometry and scanning electron microscopy to determine the areal density, the absorption and thickness of CdSe QD monolayers. SPV measurements show that initial charge separation from the CdSe QDs on ITO only happened from the fi rst monolayer of QDs. Electrons, photo-excited in the fi rst monolayer of CdSe QDs, were trapped on the ITO surface. The remaining free holes were trapped in surface states and/or diffused into the neighboring QD layers. The thick surfactant layer ({approx} 1.6 nm) of pristine QDs had to be reduced by washing and/or ligand exchange for separation of photo-excited charge carriers. Both, interparticle distance and trap density, influenced the processes of charge separation and recombination. SPV transients of CdSe monolayers could be described by a single QD approximation model, based on Miller-Abrahams hopping of holes between the delocalized excitonic state, traps on the surface of the QD and the filled trap on the ITO surface

  12. Mechanics Principle and Engineering Application of Split Layer and Bed Separation of Mining Overburden

    Institute of Scientific and Technical Information of China (English)

    YU Guang-ming; ZHANG Chun-hui; SU Zhong-jie; FAN Xue-li; PAN Yong-zhan; LIU Fu-shun

    2005-01-01

    To control land surface subsidence caused the underground mineral exploitation and the catastrophic phenomena such as serious damage of buildings, waterbodies, cultivated lands, railways, bridges caused by land subsidence, bed separation grouting technology of overburden is put forward. To provide theoretical support for the technology, the characteristics and the mechanics mechanism of mining overburden from layer-split to formation of bed separation are studied. On the basis of elastic sheet board theory, calculation formula of rock sheet deflection is presented, and the mechanics criteria of the separation formation and the calculation formula of bed separation volume are set up. Finally, the applications and technics of bed separation grout technology of mining overburden to control land subsidence in china are introduced.

  13. Effects of boundary-layer separation controllers on a desktop fume hood.

    Science.gov (United States)

    Huang, Rong Fung; Chen, Jia-Kun; Hsu, Ching Min; Hung, Shuo-Fu

    2016-10-02

    A desktop fume hood installed with an innovative design of flow boundary-layer separation controllers on the leading edges of the side plates, work surface, and corners was developed and characterized for its flow and containment leakage characteristics. The geometric features of the developed desktop fume hood included a rearward offset suction slot, two side plates, two side-plate boundary-layer separation controllers on the leading edges of the side plates, a slanted surface on the leading edge of the work surface, and two small triangular plates on the upper left and right corners of the hood face. The flow characteristics were examined using the laser-assisted smoke flow visualization technique. The containment leakages were measured by the tracer gas (sulphur hexafluoride) detection method on the hood face plane with a mannequin installed in front of the hood. The results of flow visualization showed that the smoke dispersions induced by the boundary-layer separations on the leading edges of the side plates and work surface, as well as the three-dimensional complex flows on the upper-left and -right corners of the hood face, were effectively alleviated by the boundary-layer separation controllers. The results of the tracer gas detection method with a mannequin standing in front of the hood showed that the leakage levels were negligibly small (≤0.003 ppm) at low face velocities (≥0.19 m/s).

  14. An INDEHISCENT-Controlled Auxin Response Specifies the Separation Layer in Early Arabidopsis Fruit

    NARCIS (Netherlands)

    van Gelderen, Kasper; van Rongen, Martin; Liu, An'an; Otten, Anne; Offringa, Remko

    2016-01-01

    Seed dispersal is an important moment in the life cycle of a plant species. In Arabidopsis thaliana, it is dependent on transcription factor INDEHISCENT (IND)-mediated specification of a separation layer in the dehiscence zone found in the margin between the valves (carpel walls) and the central rep

  15. Double-Layer Magnetic Nanoparticle-Embedded Silica Particles for Efficient Bio-Separation.

    Directory of Open Access Journals (Sweden)

    San Kyeong

    Full Text Available Superparamagnetic Fe3O4 nanoparticles (NPs based nanomaterials have been exploited in various biotechnology fields including biomolecule separation. However, slow accumulation of Fe3O4 NPs by magnets may limit broad applications of Fe3O4 NP-based nanomaterials. In this study, we report fabrication of Fe3O4 NPs double-layered silica nanoparticles (DL MNPs with a silica core and highly packed Fe3O4 NPs layers. The DL MNPs had a superparamagnetic property and efficient accumulation kinetics under an external magnetic field. Moreover, the magnetic field-exposed DL MNPs show quantitative accumulation, whereas Fe3O4 NPs single-layered silica nanoparticles (SL MNPs and silica-coated Fe3O4 NPs produced a saturated plateau under full recovery of the NPs. DL MNPs are promising nanomaterials with great potential to separate and analyze biomolecules.

  16. Covalent layer-by-layer grafting (LBLG) functionalized superhydrophobic stainless steel mesh for oil/water separation

    Science.gov (United States)

    Jiang, Bin; Zhang, Hongjie; Sun, Yongli; Zhang, Luhong; Xu, Lidong; Hao, Li; Yang, Huawei

    2017-06-01

    A superhydrophobic and superoleophilic stainless steel (SS) mesh for oil/water separation has been developed by using a novel, facile and inexpensive covalent layer-by-layer grafting (LBLG) method. Hierarchical micro/nanostructure surface was formed through grafting the (3-aminopropyl) triethoxysilane (SCA), polyethylenimine (PEI) and trimesoyl chloride (TMC) onto the mesh in sequence, accompanied with SiO2 nanoparticles subtly and firmly anchored in multilayers. Superhydrophobic characteristic was realized by self-assembly grafting of hydrophobic groups onto the surface. The as-prepared mesh exhibits excellent superhydrophobicity with a water contact angle of 159°. Moreover, with a low sliding angle of 4°, it shows the ;lotus effect; for self-cleaning. As for application evaluation, the as-prepared mesh can be used for large-scale separation of oil/water mixtures with a relatively high separation efficiency after 30 times reuse (99.88% for n-octane/water mixture) and a high intrusion pressure (3.58 kPa). More importantly, the mesh exhibited excellent stability in the case of vibration situation, long-term storage as well as saline corrosion conditions, and the compatible pH range was determined to be 1-13. In summary, this work provides a brand new method of modifying SS mesh in a covalent LBLG way, and makes it possible to introduce various functionalized groups onto the surface.

  17. Experimental and Analytical Method for Determining a Drag Coefficient of the Double-Layer Liquid Separator

    Directory of Open Access Journals (Sweden)

    A. A. Pozhalostin

    2015-01-01

    Full Text Available The paper considers a problem of small axisymmetric oscillations of two-layer liquid with a foam-based separator. The separator is supposed to be rigid and non-deformable, liquid flow through the separator is modeled as a stream with a certain linear-viscous resistance. The liquid is assumed to be ideal and incompressible, its stream being potential. The paper presents experimental and analytical method for finding such a drag coefficient.The work [1] considered the problem of oscillations of a two-layer liquid divided by nondeforming permeable separator where, taking into consideration the interaction between liquid and separator, a reduced drag coefficient is introduced, which is expected to be determined experimentally, thereby generalizing the results of works [4] and [5] in case of moving two-layer liquid through a resistance. The work [6] investigated the motion of ideal incompressible and non-stratified liquid together with the elastic bottom. The work [7] studied a stability of the free liquid surface in low gravity. The paper [8] examined free axially symmetric oscillations of a two-layer liquid with an impermeable separator.Analytical dependence for the drag coefficient obtained in the paper [1] contains the frequency values of free harmonic oscillation system with no resistance (with a missing delimiter and the damping coefficient for the system with resistance (with a separator available. These values can be obtained experimentally if the tank model oscillations with a separator and without it are excited and the natural frequencies of these oscillations are determined. The model under consideration can be used to analyze dynamic interaction between liquid and phase separator of the upper stage or launch vehicle stage and provide ground experimental method for the starting systems from the gravity-free state and low gravity one.The article shows the relationship of the analytic dependence of the damping coefficient at symmetric

  18. Flowfield measurements in a separated and reattached flat plate turbulent boundary layer

    Science.gov (United States)

    Patrick, William P.

    1987-03-01

    The separation and reattachment of a large-scale, two-dimensional turbulent boundary layer at low subsonic speed on a flat plate has been studied experimentally. The separation bubble was 55 cm long and had a maximum bubble thickness, measured to the height of the mean dividing streamline, of 17 cm, which was twice the thickness of the inlet boundary layer. A combination of laser velocimetry, hot-wire anemometry, pneumatic probing techniques, and flow visualization were used as diagnostics. Principal findings were that an outer inviscid rotational flow was defined which essentially convected over the blockage associated with the inner, viscously dominated bubble recirculation region. A strong backflow region in which the flow moved upstream 100 percent of the time was measured near the test surface over the central 35 percent of the bubble. A laminar backflow boundary layer having pseudo-turbulent characteristics including a log-linear velocity profile was generated under the highly turbulent backflow. Velocity profile shapes in the reversed flow region matched a previously developed universal backflow profile at the upstream edge of the separation region but not in the steady backflow region downstream. A smoke flow visualization movie and hot-film measurements revealed low frequency nonperiodic flapping at reattachment. However, forward flow fraction data at reattachment and mean velocity profiles in the redeveloping boundary layer downstream of reattachment correlated with backward-facing step data when the axial dimension was scaled by the distance from the maximum bubble thickness to reattachment.

  19. Separation control in a hypersonic shock wave / turbulent boundary-layer interaction

    Science.gov (United States)

    Schreyer, Anne-Marie; Bermejo-Moreno, Ivan; Kim, Jeonglae; Urzay, Javier

    2016-11-01

    Hypersonic vehicles play a key role for affordable access to space. The associated flow fields are strongly affected by shock wave/turbulent boundary-layer interactions, and the inherent separation causes flow distortion and low-frequency unsteadiness. Microramp sub-boundary layer vortex generators are a promising means to control separation and diminish associated detrimental effects. We investigate the effect of a microramp on the low-frequency unsteadiness in a fully separated interaction. A large eddy simulation of a 33 ∘ -compression-ramp interaction was performed for an inflow Mach number of 7.2 and a Reynolds number based on momentum thickness of Reθ = 3500 , matching the experiment of Schreyer et al. (2011). For the control case, we introduced a counter-rotating vortex pair, as induced by a single microramp, into the boundary layer through the inflow conditions. We applied a dynamic mode decomposition (DMD) on both cases to identify coherent structures that are responsible for the dynamic behavior. Based on the DMD, we discuss the reduction of the separation zone and the stabilization of the shock motion achieved by the microramp, and contribute to the description of the governing mechanisms. Pursued during the 2016 CTR Summer Program at Stanford University.

  20. Spontaneous reconnection at a separator current layer. II. Nature of the waves and flows

    CERN Document Server

    Stevenson, Julie E H

    2015-01-01

    Sudden destabilisations of the magnetic field, such as those caused by spontaneous reconnection, will produce waves and/or flows. Here, we investigate the nature of the plasma motions resulting from spontaneous reconnection at a 3D separator. In order to clearly see the perturbations generated by the reconnection, we start from a magnetohydrostatic equilibrium containing two oppositely-signed null points joined by a generic separator along which lies a twisted current layer. The nature of the magnetic reconnection initiated in this equilibrium as a result of an anomalous resistivity is discussed in detail in \\cite{Stevenson15_jgra}. The resulting sudden loss of force balance inevitably generates waves that propagate away from the diffusion region carrying the dissipated current. In their wake a twisting stagnation-flow, in planes perpendicular to the separator, feeds flux back into the original diffusion site (the separator) in order to try to regain equilibrium. This flow drives a phase of slow weak impulsiv...

  1. Thin layer chromatographic separation of cobalt from nickel on impregnated silica gel layers:quantitative determination by digital image analysis%Thin layer chromatographic separation of cobalt from nickel on impregnated silica gel layers: quantitative determination by digital image analysis

    Institute of Scientific and Technical Information of China (English)

    P A MOHAMED NAJAR; R G SONALI; M T NIMJE; K V RAMANA RAO

    2012-01-01

    Thin layer chromatography (TLC) of cobalt and nickel has been performed on silica gel layers induced with alkali mediated cellulose extract.A novel combination of 10% aqueous solutions of Tween-20 and potassium thiocyanate in 1∶ 1 (v/v) was identified as the best mobile phase for the selective separation of Co2+ from Ni2+ on the impregnated Silica Gel G layers.The chromatographic characteristics of the cations were studied and the limits of detection as well as the limits of quantification for Co2+ and Ni2+ were determined.The quantitative estimation of the cations was achieved from the digital image analysis of respective chromatograms.The proposed quantitative method was successfully applied with 0-0.50% error for the determination of Co2+ from Ni2+ in spiked samples of bauxite,soil and rock containing common cations such as Al3+,Fe2+,Ti4+,Zn2+,Mn2+,Cu2+,Cr6+,Mg2+ etc.under the optimized chromatographic conditions.

  2. Stability and phase separation in mixed monopolar lipid/bolalipid layers.

    Science.gov (United States)

    Longo, Gabriel S; Thompson, David H; Szleifer, I

    2007-10-15

    The phase stability of a fluid lipid layer that is a mixture of conventional monopolar lipids and C20 bipolar bolalipids was studied using a mean field theory that explicitly includes molecular details and configurational properties of the lipid molecules. The effect of changing the fraction of bolalipids, as well as the length of the hydrocarbon chain of the monopolar lipids, was probed. A phase separation between two liquid lipid phases was found when a mismatch exists in the optimal hydrophobic thicknesses of the pure bolalipid and monopolar lipid layers. The lipid mixture phase separates into a thin bolalipid-rich layer and a thicker monopolar-rich layer. The thin membrane phase is mainly composed of transmembrane bolalipid molecules whose polar heads are positioned at opposite membrane-water interfaces. In the monopolar lipid-rich phase, bolalipids are the minor component and most of them assume a looping configuration where both headgroups are present at the same membrane-water interface. For mixed layers that form a single lipid phase across all bolalipid concentrations, the hairpin-transmembrane ratio strongly depends on the hydrocarbon chain length of the monopolar lipid and the bolalipid concentration. The C-D bond order parameters of the different species have been calculated. Our findings suggest that the concentration-dependent phase transition should be experimentally observable by measuring of the order parameters through quadrupolar splitting experiments. The driving force for the phase separation in the monopolar lipid/bolalipid mixture is the packing mismatch between hydrophobic regions of the monopolar lipid hydrocarbon chains and the membrane-spanning bolalipid chains. The results from the molecular theory may be useful in the design of stable lipid layers for integral membrane protein sensing.

  3. Fingerprint detection and using intercalated CdSe nanoparticles on non-porous surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Algarra, Manuel, E-mail: malgarra67@gmail.com [Centro de Geología da Universidade do Porto, Departamento de Geociências, Ambiente e Ordenamemto do Territorio do Porto, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Radotić, Ksenija; Kalauzi, Aleksandar; Mutavdžić, Dragosav; Savić, Aleksandar [Institute for Multidisciplinary Research, University of Belgrade, Kneza Višeslava 1, 11000 Beograd (Serbia); Jiménez-Jiménez, José; Rodríguez-Castellón, Enrique [Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos s/n, 29071Málaga (Spain); Silva, Joaquim C.G. Esteves da [Centro de Investigação em Química (CIQ-UP). Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Guerrero-González, Juan José [Policía Científica, Cuerpo Nacional de Policía, Málaga (Spain)

    2014-02-17

    Graphical abstract: -- Highlights: •Fluorescent nanocomposite based on the inclusion of CdSe quantum dots in porous phosphate heterostructures. •Characterized by FTIR, XRD and fluorescence spectroscopies. •Deconvolution of the emission spectra was confirmed by using multivariate curve resolution (MCR) method. •Application for fingerprint detection and analysis on different non-porous surfaces. -- Abstract: A fluorescent nanocomposite based on the inclusion of CdSe quantum dots in porous phosphate heterostructures, functionalized with amino groups (PPH-NH{sub 2}@CdSe), was synthesized, characterized and used for fingerprint detection. The main scopes of this work were first to develop a friendly chemical powder for detecting latent fingerprints, especially in non-porous surfaces; their further intercalation in PPH structure enables not to spread the fluorescent nanoparticles, for that reason very good fluorescent images can be obtained. The fingerprints, obtained on different non-porous surfaces such as iron tweezers, mobile telephone screen and magnetic band of a credit card, treated with this powder emit a pale orange luminescence under ultraviolet excitation. A further image processing consists of contrast enhancement that allows obtaining positive matches according to the information supplied from a police database, and showed to be more effective than that obtained with the non-processed images. Experimental results illustrate the effectiveness of proposed methods.

  4. Preparation of Immobilized Metal Affinity Chromatographic Packings Based on Monodisperse Hydrophilic Non-porous Beads and Their Application

    Institute of Scientific and Technical Information of China (English)

    BO Chun-Miao; GONG Bo-Lin; HU Wen-Zhi

    2008-01-01

    Three hydrophilic immobilized metal affinity chromatographic packings for HPLC have been synthesized by chemical modification of 3.0 μm monodisperse non-porous poly(glycidyl methacrylate-co-ethylenedimethacrylate)(PGMMEDMA)beads.The retention behavior of proteins on the metal ion chelated columns loaded with copper(Ⅱ),nickel(Ⅱ)and zin(Ⅱ)ion was studied.The effect of pH on the protein retention Was investigated on both the naked and metal ion chelated columns in the range from 4.0 to 9.0.Four proteins were quickly separated in 3.0 min with linear gradient elution at a flow rate of 3.0 mL/min by using the synthesized Ni2+ -IDA(iminodiacetic acid)packings.The separation time was shorter than other immobilized metal affinity chromatography reported in the literature.Purification of lysozyme from egg white and trypsin on the commercially available trypsin was performed on the naked-IDA and Cu2+ -IDA columns,respectively.The purities of the purified trypsin and lysozyme were more than 92%and 95%,respectively.

  5. Separate Layer Production and Water Injection Technology Developed in Daqing Oil Field

    Institute of Scientific and Technical Information of China (English)

    Liu He

    2004-01-01

    @@ Effects of separate layer production and water injection With the improvement of geological research and development degree, the requirements to water injection are also higher than ever before. The development of water injection technology in Daqing oilfield experienced the following four stages: (1) Commingled water injection, (2)concentric water injection, (3) eccentric water injection, and (4) integrated water injection.Through the above improvements, the development technology improved quickly.

  6. Passive Separation Control on a Symmetric Airfoil via Elastic-Layer

    Directory of Open Access Journals (Sweden)

    Chedhli Hafien

    2016-01-01

    Full Text Available The passive control of flow-separation at averaged Reynolds Number (Re=3.42×105 using self-adapting flexible-flaps in the upper side of the wing, is presented. The two-way Fluid-Structure Interaction (FSI in an elastic-layer up on the airfoil (NACA 0012 is investigated numerically by Coupling between the Transient Structural and Fluid Flow (Fluent in ANSYS-Workbench14.0. During the fluid-structure interaction, the transient deformation of the elastic-layer provokes the modification of the flow topology at large-scale. There are reductions of the size and intensity of the vortex-shedding and an increase in the Strouhal number. This explains the increase of the lift-to-drag ratio. The study of the flap flexibility shows that the deformation of the elastic-layer and the variation of aeronautical efforts are inversely proportional to the Young Modulus.

  7. Investigation of Shock-Induced Laminar Separation Bubble in a Supersonic Boundary Layer

    Science.gov (United States)

    Sivasubramanian, Jayahar; Fasel, Hermann

    2015-11-01

    The interaction between an impinging oblique shock and a laminar boundary-layer on a flat plate is investigated using DNS. In particular, the two-dimensional separation bubble resulting from the shock/boundary-layer interaction (SBLI) at freestream Mach number of 2.0 is investigated in detail. The flow parameters used for the present investigation match the laboratory conditions in the experiments by Hakkinen et al. The skin friction and pressure distribution from the simulations are compared to the experimental measurements and numerical results available in the literature. Our results confirm the asymmetric nature of the separation bubble as reported in the literature. In addition to the steady flow field calculations, the response to low-amplitude disturbances is investigated in order to study the linear stability behavior of the separation bubble. For comparison, both the development of two-dimensional and three-dimensional (oblique) disturbances are studied with and without the impinging oblique shock. Furthermore, the effects of the shock incidence angle and Reynolds number are also investigated. Finally, three-dimensional simulations were performed in order to explore the laminar-turbulent transition process in the presence of a laminar separation bubble. Funded by the Air Force Office of Scientific Research under grant FA9550-14-1-0195.

  8. Boundary layer separation and reattachment detection on airfoils by thermal flow sensors.

    Science.gov (United States)

    Sturm, Hannes; Dumstorff, Gerrit; Busche, Peter; Westermann, Dieter; Lang, Walter

    2012-10-24

    A sensor concept for detection of boundary layer separation (flow separation, stall) and reattachment on airfoils is introduced in this paper. Boundary layer separation and reattachment are phenomena of fluid mechanics showing characteristics of extinction and even inversion of the flow velocity on an overflowed surface. The flow sensor used in this work is able to measure the flow velocity in terms of direction and quantity at the sensor's position and expected to determine those specific flow conditions. Therefore, an array of thermal flow sensors has been integrated (flush-mounted) on an airfoil and placed in a wind tunnel for measurement. Sensor signals have been recorded at different wind speeds and angles of attack for different positions on the airfoil. The sensors used here are based on the change of temperature distribution on a membrane (calorimetric principle). Thermopiles are used as temperature sensors in this approach offering a baseline free sensor signal, which is favorable for measurements at zero flow. Measurement results show clear separation points (zero flow) and even negative flow values (back flow) for all sensor positions. In addition to standard silicon-based flow sensors, a polymer-based flexible approach has been tested showing similar results.

  9. Bacterial surface layer proteins as a novel capillary coating material for capillary electrophoretic separations

    Energy Technology Data Exchange (ETDEWEB)

    Moreno-Gordaliza, Estefanía, E-mail: emorenog@ucm.es [Division of Analytical Biosciences, Leiden Academic Centre for Drug Research, Universiteit Leiden, Einsteinweg 55, 2300, RA, Leiden (Netherlands); Department of Analytical Chemistry, Faculty of Chemistry, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040, Madrid (Spain); Stigter, Edwin C.A. [Division of Analytical Biosciences, Leiden Academic Centre for Drug Research, Universiteit Leiden, Einsteinweg 55, 2300, RA, Leiden (Netherlands); Department of Molecular Cancer Research, Universitair Medisch Centrum Utrecht, Wilhelmina Kinder Ziekenhuis, Lundlaan 6, 3584, EA Utrecht (Netherlands); Lindenburg, Petrus W.; Hankemeier, Thomas [Division of Analytical Biosciences, Leiden Academic Centre for Drug Research, Universiteit Leiden, Einsteinweg 55, 2300, RA, Leiden (Netherlands)

    2016-06-07

    A novel concept for stable coating in capillary electrophoresis, based on recrystallization of surface layer proteins on hydrophobized fused silica capillaries, was demonstrated. Surface layer protein A (SlpA) from Lactobacillus acidophilus bacteria was extracted, purified and used for coating pre-silanized glass substrates presenting different surface wettabilities (either hydrophobic or hydrophilic). Contact angle determination on SlpA-coated hydrophobic silica slides showed that the surfaces turned to hydrophilic after coating (53 ± 5°), due to a protein monolayer formation by protein-surface hydrophobic interactions. Visualization by atomic force microscopy demonstrated the presence of a SlpA layer on methylated silica slides displaying a surface roughness of 0.44 ± 0.02 nm. Additionally, a protein layer was visualized by fluorescence microscopy in methylated silica capillaries coated with SlpA and fluorescein isothiocyanate-labeled. The SlpA-coating showed an outstanding stability, even after treatment with 20 mM NaOH (pH 12.3). The electroosmotic flow in coated capillaries showed a partial suppression at pH 7.50 (3.8 ± 0.5 10{sup −9} m{sup 2} V{sup −1} s{sup −1}) when compared with unmodified fused silica (5.9 ± 0.1 10{sup −8} m{sup 2} V{sup −1} s{sup −1}). To demonstrate the potential of this novel coating, the SlpA-coated capillaries were applied for the first time for electrophoretic separation, and proved to be very suitable for the isotachophoretic separation of lipoproteins in human serum. The separations showed a high degree of repeatability (absolute migration times with 1.1–1.8% coefficient-of-variation (CV) within a day) and 2–3% CV inter-capillary reproducibility. The capillaries were stable for more than 100 runs at pH 9.40, and showed to be an exceptional alternative for challenging electrophoretic separations at long-term use. - Highlights: • New coating using recrystallized surface-layer proteins on

  10. Characterization of an incipiently separated shock wave/turbulent boundary layer interaction

    Science.gov (United States)

    Schreyer, A.-M.; Dussauge, J.-P.; Krämer, E.

    2017-03-01

    The turbulence structure in a shock wave/turbulent boundary layer interaction at incipient separation was investigated in order to get insight into turbulence generation and amplification mechanisms in such flow fields. The flow along a two-dimensional 11.5° compression corner was studied experimentally at a Mach number of M=2.53 and with a momentum-thickness Reynolds number of Re_{θ }=5370. From hot-wire boundary layer traverses and surface heat-flux density fluctuation measurements with the fast-response atomic layer thermopile, the turbulence structure and amplification was described. Space-time correlations of the mass-flux fluctuations across the boundary layer and the surface heat-flux density fluctuations were measured to further characterize the development of the turbulence structure across the interaction. The large-scale boundary layer structures are concealed by shock-related effects in the strongly disturbed shock-foot region. Shortly downstream, however, large-scale structures dominate the signal again, just as in the incoming flow. A mechanism explaining this behavior is suggested.

  11. Three Dimensional Separation with Spiral-Focus in a Decelerating Duct Flow (Effect of Asymmetric Inlet Boundary Layer Thickness)

    Institute of Scientific and Technical Information of China (English)

    Yoichi Kinoue; Toshiaki Setoguchi; Kenji Kaneko; Mamun Mohammad; Masahiro Inoue

    2003-01-01

    An experimental apparatus was developed to study the three dimensional separated flow with spiral-foci. The internal decelerating flow was generated by the air suction from a side wall to produce the separation on an opposite-side wall. The relation between the upstream boundary layer and the generation of spiral-foci in the separation region was observed by a tuft method. As a result, it was clarified that the spiral-focus type separation could be produced on the side wall and its behavior was closely related to the vortices supplied into the separation region from the boundary layer developing along top wall or bottom one.

  12. STUDY OF THREE-DIMENSIONAL SEPARATION OF BOUNDARY LAYER OVER BLUNT BODIES

    Institute of Scientific and Technical Information of China (English)

    ATMANI R.; BRIMA A.; ASKOVIC R.

    2009-01-01

    In the case of three-dimensional flows,the separation can be defined in more than one way.Discussions about three-dimensional boundary layer separation in the literature have found a rational extension of the zero skin friction.Attempts have been made to establish the identity of "separation lines".Among definitions,these may be found:(1)envelopes of limiting streamlines,(2)lines dividing flow which has come from different regions,(3)lines of singularities(problems of topology),(4)lines on which some component of the skin friction vanishes.Each of these is valid under certain conditions,but none is universally valid.In the present work,we use the definition(4),i.e.at low incidence of a blunt body the separation line is identified as the zero of the meridian skin friction component(Wang 1975).So the separation line on a flattened spheroid(6:3:1)at 6o of incidence is calculated,as well as experimentally determined by using the electrochemical method,which allows to follow the evolution of the parietal velocity gradient.

  13. LS Channel Estimation and Signal Separation for UHF RFID Tag Collision Recovery on the Physical Layer.

    Science.gov (United States)

    Duan, Hanjun; Wu, Haifeng; Zeng, Yu; Chen, Yuebin

    2016-03-26

    In a passive ultra-high frequency (UHF) radio-frequency identification (RFID) system, tag collision is generally resolved on a medium access control (MAC) layer. However, some of collided tag signals could be recovered on a physical (PHY) layer and, thus, enhance the identification efficiency of the RFID system. For the recovery on the PHY layer, channel estimation is a critical issue. Good channel estimation will help to recover the collided signals. Existing channel estimates work well for two collided tags. When the number of collided tags is beyond two, however, the existing estimates have more estimation errors. In this paper, we propose a novel channel estimate for the UHF RFID system. It adopts an orthogonal matrix based on the information of preambles which is known for a reader and applies a minimum-mean-square-error (MMSE) criterion to estimate channels. From the estimated channel, we could accurately separate the collided signals and recover them. By means of numerical results, we show that the proposed estimate has lower estimation errors and higher separation efficiency than the existing estimates.

  14. Micro vortex generator control of axisymmetric high-speed laminar boundary layer separation

    Science.gov (United States)

    Estruch-Samper, D.; Vanstone, L.; Hillier, R.; Ganapathisubramani, B.

    2015-09-01

    Interest in the development of micro vortex generators (MVGs) to control high-speed flow separation has grown in the last decade. In contrast to conventional vortex generators, MVGs are fully submerged in the boundary layer and have the potential of inducing surface flow mixing with marginal drag penalty when suitably designed. Also, they do not result in undesired reduced mass flow such as with suction methods. The flow mechanisms at the location of MVGs are not yet fully understood, and optimal designs are difficult to establish given that both numerical predictions and experiments are particularly challenged for short element heights, yet optimal MVGs are generally expected to be at least shorter than half the local boundary layer thickness. The present work aims at investigating experimentally the fundamental flow physics concerning an individual MVG element (of `canonical' or simplified geometry) at a range of near-wall heights. A fully laminar base flow is considered so as to isolate the effect of incoming turbulence as well as the more complex physics that may occur when specific and/or multiple elements are used. Tests were performed in a gun tunnel at a freestream Mach number of 8.9 and Reynolds number of /m, and the basic test model consisted of a blunt-nosed cylinder which produced an axisymmetric laminar boundary layer with an edge Mach number of 3.4 and Reynolds number of /m at the MVG location. A laminar shock-wave/boundary layer interaction with separation was induced by a flare located further downstream on the model. Measurements consisted of time-resolved surface heat transfer obtained in the axial direction immediately downstream of the MVG and along the interaction, together with simultaneous high-speed schlieren imaging. The height () of the MVG element used in a `diamond' configuration (square planform with one vertex facing the flow) was adjusted between tests ranging from = 0.03 to 0.58, where the local undisturbed boundary layer thickness

  15. Turbulent boundary layer separation control using plasma actuator at Reynolds number 2000000

    Institute of Scientific and Technical Information of China (English)

    Zhang Xin; Huang Yong; Wang Xunnian; Wang Wanbo; Tang Kun; Li Huaxing

    2016-01-01

    An experimental investigation was conducted to evaluate the effect of symmetrical plasma actuators on turbulent boundary layer separation control at high Reynolds number. Com-pared with the traditional control method of plasma actuator, the whole test model was made of aluminum and acted as a covered electrode of the symmetrical plasma actuator. The experimental study of plasma actuators’ effect on surrounding air, a canonical zero-pressure gradient turbulent boundary, was carried out using particle image velocimetry (PIV) and laser Doppler velocimetry (LDV) in the 0.75 m ? 0.75 m low speed wind tunnel to reveal the symmetrical plasma actuator characterization in an external flow. A half model of wing-body configuration was experimentally investigated in the £ 3.2 m low speed wind tunnel with a six-component strain gauge balance and PIV. The results show that the turbulent boundary layer separation of wing can be obviously sup-pressed and the maximum lift coefficient is improved at high Reynolds number with the symmetri-cal plasma actuator. It turns out that the maximum lift coefficient increased by approximately 8.98% and the stall angle of attack was delayed by approximately 2? at Reynolds number 2 ? 106. The effective mechanism for the turbulent separation control by the symmetrical plasma actuators is to induce the vortex near the wing surface which could create the relatively large-scale disturbance and promote momentum mixing between low speed flow and main flow regions.

  16. Separated effects of ions, metastables and photons on the properties of barrier layers on polymers

    Science.gov (United States)

    Biskup, Beatrix; Boeke, Marc; Benedikt, Jan; von Keudell, Achim

    2016-09-01

    Analyses of a-C:H /a-Si:H multilayers on polymer substrates indicated that prolonged ion bombardment influences negatively the properties of the barrier layer, while a short plasma pretreatment can improve the barrier effect. This work is motivated by these results and investigates the influence of different reactive plasma components, namely ions, metastables and VUV-photons, on the properties of the grown barrier layer. To separate the different species and their influence on plasma pretreatment and film growth, we build a grid system, which repels the ions from the substrate, so that only metastables and VUV-photons have an effect on the layer. An integral part of this investigation is, to measure the photon fluxes to the substrate by an intensity calibrated VUV monochromator. For that, a differentially pumped monochromator with a spectral range 30 - 300 nm is used, where the two most prominent argon lines at 104.9 and 106.8 nm can be measured. In this approach we are able to study the different effects of the plasma species and also possible synergy effects, to improve the properties of the barrier layer. This work is supported by the DFG within the SFB-TR 87.

  17. Separation of catechins and O-methylated (-)-epigallocatechin gallate using polyamide thin-layer chromatography.

    Science.gov (United States)

    Wang, Kunbo; Chen, Qincao; Lin, Yong; Yu, Shuangshang; Lin, Haiyan; Huang, Jianan; Liu, Zhonghua

    2016-04-01

    Thin-layer chromatography (TLC) method for the separation and quantitative determination of seven related compounds: (+)-catechin (C), (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG), (-)-epigallocatechin gallate (EGCG), (-)-epigallocatechin-3-O-(3-O-methyl) gallate (EGCG3″Me) and (-)-epigallocatechin- 3-O-(4-O-methyl) gallate (EGCG4″Me) has been developed. The above-mentioned seven compounds have been resolved using polyamide TLC plates using a double-development with methanol followed by acetone/acetic acid (2:1, v/v). In addition, separation of the phenolic acids namely gallic acid, chlorogenic acid, and caffeic acid was achieved using the same solvent system. The applicability of the method was checked by screening of extracts of green, black, oolong, white tea and tea cultivars leaves. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Dielectric barrier discharge ionization in characterization of organic compounds separated on thin-layer chromatography plates.

    Science.gov (United States)

    Cegłowski, Michał; Smoluch, Marek; Babij, Michał; Gotszalk, Teodor; Silberring, Jerzy; Schroeder, Grzegorz

    2014-01-01

    A new method for on-spot detection and characterization of organic compounds resolved on thin layer chromatography (TLC) plates has been proposed. This method combines TLC with dielectric barrier discharge ionization (DBDI), which produces stable low-temperature plasma. At first, the compounds were separated on TLC plates and then their mass spectra were directly obtained with no additional sample preparation. To obtain good quality spectra the center of a particular TLC spot was heated from the bottom to increase volatility of the compound. MS/MS analyses were also performed to additionally characterize all analytes. The detection limit of proposed method was estimated to be 100 ng/spot of compound.

  19. Thin-layer chromatographic (TLC) separations and bioassays of plant extracts to identify antimicrobial compounds.

    Science.gov (United States)

    Kagan, Isabelle A; Flythe, Michael D

    2014-03-27

    A common screen for plant antimicrobial compounds consists of separating plant extracts by paper or thin-layer chromatography (PC or TLC), exposing the chromatograms to microbial suspensions (e.g. fungi or bacteria in broth or agar), allowing time for the microbes to grow in a humid environment, and visualizing zones with no microbial growth. The effectiveness of this screening method, known as bioautography, depends on both the quality of the chromatographic separation and the care taken with microbial culture conditions. This paper describes standard protocols for TLC and contact bioautography with a novel application to amino acid-fermenting bacteria. The extract is separated on flexible (aluminum-backed) silica TLC plates, and bands are visualized under ultraviolet (UV) light. Zones are cut out and incubated face down onto agar inoculated with the test microorganism. Inhibitory bands are visualized by staining the agar plates with tetrazolium red. The method is applied to the separation of red clover (Trifolium pratense cv. Kenland) phenolic compounds and their screening for activity against Clostridium sticklandii, a hyper ammonia-producing bacterium (HAB) that is native to the bovine rumen. The TLC methods apply to many types of plant extracts and other bacterial species (aerobic or anaerobic), as well as fungi, can be used as test organisms if culture conditions are modified to fit the growth requirements of the species.

  20. Improved separation and analysis of glycolipids by Iatroscan thin-layer chromatography-flame ionization detection.

    Science.gov (United States)

    Gašparović, Blaženka; Kazazić, Snježana P; Cvitešić, Ana; Penezić, Abra; Frka, Sanja

    2015-08-28

    We demonstrate improved power of Iatroscan thin layer chromatography/flame ionization detection (TLC-FID) technique for analysis of complex marine lipid mixture by developing protocol for the separation and analysis of glycolipids including sulfoquinovosyldiacylglycerols (SQDG), monogalactosyldiacylglycerols (MGDG) and digalactosyldiacylglycerols (DGDG). We have modified the common protocol used so far for the analysis of lipid classes by replacing the elution step which uses pure acetone for the elution of acetone mobile polar lipids, with the elution step containing chloroform-acetone (72:28, v:v) for separation of MGDG and DGDG. To separate SQDG from the complex lipid matrix we introduced solvent mixture acetone-chloroform-methanol-formic acid (33:33:33:0.6, v:v:v:v). Quantification of glycolipid classes was performed after calibration with glycolipid standards for the masses between 0.2 and 2.7-5.0μg. With this new protocol we have successfully separated three glycolipids from the complex particulate lipid mixture of the seawater samples. Such an approach extends the power of existing protocol for the analysis of lipids which altogether ensure detection and quantification of 18 lipid classes what was demonstrated on seawater samples. This enables to gain a very broad system overview of the particularly complex environments as are seas, oceans and freshwaters. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Spontaneous reconnection at a separator current layer: 2. Nature of the waves and flows

    Science.gov (United States)

    Stevenson, J. E. H.; Parnell, C. E.

    2015-12-01

    Sudden destabilizations of the magnetic field, such as those caused by spontaneous reconnection, will produce waves and/or flows. Here we investigate the nature of the plasma motions resulting from spontaneous reconnection at a 3-D separator. In order to clearly see these perturbations, we start from a magnetohydrostatic equilibrium containing two oppositely signed null points joined by a generic separator along which lies a twisted current layer. The nature of the magnetic reconnection initiated in this equilibrium as a result of an anomalous diffusivity is discussed in detail in Stevenson and Parnell (2015). The resulting sudden loss of force balance inevitably generates waves that propagate away from the diffusion region carrying the dissipated current. In their wake a twisting stagnation flow, in planes perpendicular to the separator, feeds flux back into the original diffusion site (the separator) in order to try to regain equilibrium. This flow drives a phase of slow weak impulsive bursty reconnection that follows on after the initial fast-reconnection phase.

  2. Boundary layer and separation control on wings at low Reynolds numbers

    Science.gov (United States)

    Yang, Shanling

    Results on boundary layer and separation control through acoustic excitation at low Re numbers are reported. The Eppler 387 profile is specifically chosen because of its pre-stall hysteresis and bi-stable state behavior in the transitional Re regime, which is a result of flow separation and reattachment. External acoustic forcing on the wing yields large improvements (more than 70%) in lift-to-drag ratio and flow reattachment at forcing frequencies that correlate with the measured anti-resonances in the wind tunnel. The optimum St/Re1/2 range for Re = 60,000 matches the proposed optimum range in the literature, but there is less agreement for Re = 40,000, which suggests that correct St scaling has not been determined. The correlation of aerodynamic improvements to wind tunnel resonances implies that external acoustic forcing is facility-dependent, which inhibits practical application. Therefore, internal acoustic excitation for the same wing profile is also pursued. Internal acoustic forcing is designed to be accomplished by embedding small speakers inside a custom-designed wing that contains many internal cavities and small holes in the suction surface. However, initial testing of this semi-porous wing model shows that the presence of the small holes in the suction surface completely transforms the aerodynamic performance by changing the mean chordwise separation location and causing an originally separated, low-lift state flow to reattach into a high-lift state. The aerodynamic improvements are not caused by the geometry of the small holes themselves, but rather by Helmholtz resonance that occurs in the cavities, which generate tones that closely match the intrinsic flow instabilities. Essentially, opening and closing holes in the suction surface of a wing, perhaps by digital control, can be used as a means of passive separation control. Given the similarity of wing-embedded pressure tap systems to Helmholtz resonators, particular attention must be given to the

  3. Nanoporous layered silicate AMH-3/cellulose acetate nanocomposite membranes for gas separations

    KAUST Repository

    Kim, Wun-gwi

    2013-08-01

    Nanoporous layered silicate/polymer composite membranes are of interest because they can exploit the high aspect ratio of exfoliated selective flakes/layers to enhance molecular sieving and create a highly tortuous transport path for the slower molecules. In this work, we combine membrane synthesis, detailed microstructural characterization, and mixed gas permeation measurements to demonstrate that nanoporous flake/polymer membranes allows significant improvement in gas permeability while maintaining selectivity. We begin with the primary-amine-intercalated porous layered silicate SAMH-3 and show that it can be exfoliated using a high shear rate generated by a high-speed mixer. The exfoliated SAMH-3 flakes were used to form SAMH-3/cellulose acetate (CA) membranes. Their microstructure was analyzed by small angle X-ray scattering (SAXS), revealing a high degree of exfoliation of AMH-3 layers in the CA membrane with a small number of layers (4-8) in the exfoliated flakes. TEM analysis visualized the thickness of the flakes as 15-30nm, and is consistent with the SAXS analysis. The CO2/CH4 gas separation performance of the CA membrane was significantly increased by incorporating only 2-6wt% of SAMH-3 flakes. There was a large increase in CO2 permeability with maintenance of selectivity. This cannot be explained by conventional models of transport in flake-containing membranes, and indicates complex transport paths in the membrane. It is also in contrast to the much higher loadings of isotropic particles required for similar enhancements. The present approach may allow avoidance of particle aggregation and poor interfacial adhesion associated with larger quantities of inorganic fillers. © 2013 Elsevier B.V.

  4. REVIEW ON POROUS AND NON-POROUS FLAT PLATE AIR COLLECTOR WITH MIRROR ENCLOSURE

    Directory of Open Access Journals (Sweden)

    M. PRADHAPRAJ,

    2010-09-01

    Full Text Available In solar air heater, flat plat collectors are the best heat transferring devices. But the effectiveness of these collectorsis very low because of lack of technology. Solar assisted heated air is successfully used for drying applications and space heating under controlled conditions. From the solar flat plate air heater the hot air is transferred to a conventional dryer or to the combined heater and drying chamber directly. Hence, solar assisted air heaters arecheaper and reliable. The important factors affecting these systems are the solar radiation, mechanical loading, temperature and leakage. The air heater efficiency depends on the design of the system as well as the construction materials and the assembly. The solar air heating systems has acceptable life span of 15 to 20 years. The addition ofside mirror enclosures is to increase the amount of solar radiation absorption at the collector plate so that the collector increases the yield and operate in a higher temperature range. Therefore with the addition of side mirrors one can able to maximize the output of fixed flat plate collectors. A flat plate air collector will be more efficient if it is made up of porous medium when comparing it with the non porous collectors according to the study. In this paper, the performances of porous and non-porous absorber plates are discussed. Also the possible methods of finding out air leakages and the methodology adopted for the performance and efficiency calculations are also discussed.

  5. Novel polydopamine imprinting layers coated magnetic carbon nanotubes for specific separation of lysozyme from egg white.

    Science.gov (United States)

    Gao, Ruixia; Zhang, Lili; Hao, Yi; Cui, Xihui; Liu, Dechun; Zhang, Min; Tang, Yuhai

    2015-11-01

    Novel core-shell nanocomposites, consisting of magnetic carbon nanotubes (MCNTs) core surrounded by a thin polydopamine (PDA) imprinting shell for specific recognition of lysozyme (Lyz), were fabricated for the first time. The obtained products were characterized and the results showed that the PDA layer was successfully attached onto the surface of MCNTs and the corresponding thickness of imprinting layer was just about 10nm which could enable the template access the recognition cavities easily. The polymerization conditions and adsorption performance of the resultant nanomaterials were investigated in detail. The results indicated that the obtained imprinted polymers showed fast kinetic and high affinity towards Lyz and could be used to specifically separate Lyz from real egg white. In addition, the prepared materials had excellent stability and no obvious deterioration after five adsorption-regeneration cycles. Easy preparation, rapid separation, high binding capacity, and satisfactory selectivity for the template protein make this polymer attractive in biotechnology and biosensors. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Turbulent boundary layer separation control using plasma actuator at Reynolds number 2000000

    Directory of Open Access Journals (Sweden)

    Zhang Xin

    2016-10-01

    Full Text Available An experimental investigation was conducted to evaluate the effect of symmetrical plasma actuators on turbulent boundary layer separation control at high Reynolds number. Compared with the traditional control method of plasma actuator, the whole test model was made of aluminum and acted as a covered electrode of the symmetrical plasma actuator. The experimental study of plasma actuators’ effect on surrounding air, a canonical zero-pressure gradient turbulent boundary, was carried out using particle image velocimetry (PIV and laser Doppler velocimetry (LDV in the 0.75 m × 0.75 m low speed wind tunnel to reveal the symmetrical plasma actuator characterization in an external flow. A half model of wing-body configuration was experimentally investigated in the ∅ 3.2 m low speed wind tunnel with a six-component strain gauge balance and PIV. The results show that the turbulent boundary layer separation of wing can be obviously suppressed and the maximum lift coefficient is improved at high Reynolds number with the symmetrical plasma actuator. It turns out that the maximum lift coefficient increased by approximately 8.98% and the stall angle of attack was delayed by approximately 2° at Reynolds number 2 × 106. The effective mechanism for the turbulent separation control by the symmetrical plasma actuators is to induce the vortex near the wing surface which could create the relatively large-scale disturbance and promote momentum mixing between low speed flow and main flow regions.

  7. Active Control of Airfoil Boundary Layer Separation and Wake using Ns-DBD Plasma Actuators

    Science.gov (United States)

    Durasiewicz, Claudia; Castro Maldonado, Jorge; Little, Jesse

    2016-11-01

    Nanosecond pulse driven dielectric barrier discharge (ns-DBD) plasma actuators are employed to control boundary layer separation and the wake of a NACA 0012 airfoil having aspect ratio of three. Ns-DBD plasma actuators are known to operate via a thermal mechanism in contrast to ac-DBDs which are momentum-based devices. Nominally 2D forcing is applied to the airfoil leading edge with pulse energy of 0.35 mJ/cm. Experiments are conducted at a Reynolds number of 0 . 74 ×106 primarily at 18° incidence which is well within the stalled regime. Baseline and controlled flow fields are studied using surface pressure measurements, constant temperature anemometry (CTA) and PIV. Forcing at a dimensionless frequency of F+ = fc /U∞ = 1 . 14 results in reattachment of nominally separated flow to the airfoil surface. Lower frequency forcing is less optimal for separation control, but produces strong fluctuations in the wake which are intended for use in the study of vortex body interaction in the future. Actuation below F+ = 0 . 23 shows behavior consistent with an impulse-like response while forcing in the range 0 . 23

  8. Layered double hydroxide functionalized textile for effective oil/water separation and selective oil adsorption.

    Science.gov (United States)

    Liu, Xiaojuan; Ge, Lei; Li, Wei; Wang, Xiuzhong; Li, Feng

    2015-01-14

    The removal of oil and organic pollutants from water is highly desired due to frequent oil spill accidents, as well as the increase of industrial oily wastewater. Here, superhydrophobic and superoleophilic textile has been successfully prepared for the application of effective oil/water separation and selective oil adsorption. This textile was fabricated by functionalizing the commercial textile with layered double hydroxide (LDH) microcrystals and low surface energy molecules. The LDH microcrystals were immobilized on the microfibers of the textile through an in situ growth method, and they formed a nestlike microstructure. The combination of the hierarchical structure and the low surface energy molecules made the textile superhydrophobic and superoleophilic. Further experiments demonstrated that the as-prepared textile not only can be applied as effective membrane materials for the separation of oil and water mixtures with high separation efficiency (>97%), but also can be used as a bag for the selective oil adsorption from water. Thus, such superhydrophobic and superoleophilic textile is a very promising material for the application of oil spill cleanup and industrial oily wastewater treatment.

  9. Methods for calculating the transonic boundary layer separation for V/STOL inlets at high incidence angles

    Science.gov (United States)

    Chou, D. C.; Lee, H. C.; Luidens, R. W.; Stockman, N. O.

    1978-01-01

    A semi-empirical scheme for the prediction of transonic pressure distribution on the surface of V/STOL inlets at high incidence angles has been developed. The investigation is intended to improve the boundary layer calculation and separation prediction by including the effects of shock wave-boundary layer interaction into the Lewis Inlet Viscous Computer Program. Wind-tunnel results and theoretical pressure calculation for critical cases are used in constructing the transonic pressure distribution. The program, which describes the development of the boundary layer and predicts the possible flow separation, can handle the cases of inlets at high incidence angles where local supersonic region may occur in the flow.

  10. Investigation of a transonic separating/reattaching shear layer by means of PIV

    Directory of Open Access Journals (Sweden)

    S. Scharnowski

    2015-01-01

    Full Text Available The separating/reattaching flow over an axisymmetric backward-facing step is analyzed experimentally by means of particle image velocimetry (PIV. The main purpose of the measurements is the investigation of the mean flow field as well as of the Reynolds stress distributions at a Mach number of 0.7 and at a Reynolds number of 3.3×105 based on the step height. Due to the strong progress of optical flow measurements in the last years it was possible to resolve all flow scales down to 180μm (≈1% of the step height with high precision. Thanks to the high spatial resolution it was found for the first time that the Reynolds stress distribution features a local minimum between the first part of the shear layer and a region inside the recirculation region. This implies a more complex wake dynamics than assumed before.

  11. Separation of nonionic compounds by electrokinetic chromatography using an inorganic layered compound as a pseudostationary phase.

    Science.gov (United States)

    Koike, Ryo; Kitagawa, Fumihiko; Otsuka, Koji

    2008-03-01

    The use of an inorganic layered compound as a pseudostationary phase (PSP) in EKC was investigated. A synthetic smectite, which is the most typical swellable clay mineral, with an average diameter of 130 nm was selected as the PSP. The retention characteristics of the smectite and on-line sample concentration by sweeping were examined for the analysis of polyoxyethylene mono phenyl ethers (PPEs) with different degrees of ethoxylation. The retention factor was increased with increase in the number of ethylene oxide groups and a good separation of the PPE homologs was achieved by smectite-EKC. The RSD of the migration time, plate number, and peak area were 0.60, 8.3, and 2.7% (n = 5), respectively. The developed method can be applied to the analysis of PPEs in commercially available consumer products without any sample pretreatments. In addition, ca. 100-fold sensitivity enhancements for the PPEs with high retention factors were obtained by sweeping.

  12. Preparation and Characterization of Non-porous Superparamagnetic Microspheres with Epoxy Groups by Dispersion Polymerization

    Institute of Scientific and Technical Information of China (English)

    马志亚; 官月平; 刘先桥; 刘会洲

    2005-01-01

    Non-porous superparamagnetic polymer microspheres with epoxy groups were prepared by dispersion polymerization of glycidyl methacrylate (GMA) in the presence of magnetic iron oxide (Fe3O4) nanoparticles coated with oleic acid. The polymerization was carried out in the ethanol/water medium using polyvinylpyrrolidone (PVP) and 2,2’-azobisisobutyronitrile (AIBN) as stabilizer and initiator, respectively. The magnetic microspheres obtained were characterized with scanning electron microscopy (SEM), vibrating sample magnetometry (VSM) and Fourier transform infrared spectroscopy (FTIR). The results showed that the magnetic microspheres had an average size of-1μm with superparamagnetic characteristics. The saturation magnetization was found to be 4.5emu.g-1. There was abundance of epoxy groups with density of 0.028 mmol·g-1 in microspheres. The magnetic PGMA microspheres have extensive potential uses in magnetic bioseparation and biotechnology.

  13. Selective separation and determination of isoproterenol on thin layers of bismuth silicate ion-exchanger.

    Science.gov (United States)

    Ghoulipour Vanik; Hassankhani-Majd Zahra

    2015-06-01

    A simple and sensitive method for the separation and determination of isoproterenol from other doping drugs has been developed on thin layers of bismuth silicate, a synthetic inorganic ion exchanger as adsorbent in thin layer chromatography (TLC). A mixture of methanol and 0.1 mol/L formic acid (3:7, v/v) was employed as the mobile phase. The development time was 32 min. The quantitative measurement were performed with a Camag TLC Scanner-3 at wavelength (λ) of 410 nm. The isoproterenol recovery in this procedure was 98.9%. The linear correlation coefficient was greater than 0. 987 1 and the relative standard deviation (RSD) was less than 0.94. The limit of detection (LOD) and limit of quantification ( LOQ) were 7.7 x 10(-7) mol/L and 3.85 x 10(-6) mol/L, respectively. This method has been applied in the determination of isoproterenol in dosage forms and in biological fluids.

  14. Selective separation and determination of isoproterenol on thin layers of bismuth silicate ion-exchanger

    Institute of Scientific and Technical Information of China (English)

    Vanik GHOULIPOUR; Zahra HASSANKHANI-MAJD

    2015-01-01

    A simple and sensitive method for the separation and determination of isoproterenol from other do-ping drugs has been developed on thin layers of bismuth silicate,a synthetic inorganic ion exchanger as adsor-bent in thin layer chromatography(TLC). A mixture of methanol and 0. 1 mol/L formic acid(3:7,v/v)was employed as the mobile phase. The development time was 32 min. The quantitative measurement were per-formed with a Camag TLC Scanner-3 at wavelength(λ)of 410 nm. The isoproterenol recovery in this procedure was 98. 9%. The linear correlation coefficient was greater than 0. 987 1 and the relative standard deviation (RSD)was less than 0.94. The limit of detection(LOD)and limit of quantification(LOQ)were 7.7×10-7 mol/L and 3. 85 ×10-6 mol/L,respectively. This method has been applied in the determination of isoproterenol in dosage forms and in biological fluids.

  15. Open-loop control of noise amplification in a separated boundary layer flow

    CERN Document Server

    Boujo, Edouard; Gallaire, François

    2014-01-01

    Linear optimal gains are computed for the subcritical two-dimensional separated boundary-layer flow past a bump. Very large optimal gain values are found, making it possible for small-amplitude noise to be strongly amplified and to destabilize the flow. The optimal forcing is located close to the summit of the bump, while the optimal response is the largest in the shear layer. The largest amplification occurs at frequencies corresponding to eigenvalues which first become unstable at higher Reynolds number. Nonlinear direct numerical simulations show that a low level of noise is indeed sufficient to trigger random flow unsteadiness, characterized here by large-scale vortex shedding. Next, a variational technique is used to compute efficiently the sensitivity of optimal gains to steady control (through source of momentum in the flow, or blowing/suction at the wall). A systematic analysis at several frequencies identifies the bump summit as the most sensitive region for control with wall actuation. Based on thes...

  16. The Role Seemingly of Amorphous Silica Gel Layers in Chiral Separations by Planar Chromatography

    Directory of Open Access Journals (Sweden)

    Teresa Kowalska

    2007-12-01

    Full Text Available In planar chromatography, silica gel appears as the most frequently used adsorbent. Its preference as planar chromatographic stationary phase is due to its high specific surface area (ca. 700 m2 g-1 and relatively simple active sites (silanol groups, Si-OH. The high specific surface area of silica gel and a high density of coverage of its surface with the silanol active sites contribute jointly to an excellent separation performance of this adsorbent. In our experiments on chiral separation of the enantiomer pairs by planar chromatography, contradictory behavior of the silica gel layers versus the chiral compounds was observed. The migration tracks of chiral compounds in the ascending planar chromatographic mode were not vertical but bent on either side being a function of analyte chirality. This deviation of the analyte’s migration track was noticed, when using the densitometric scanner to quantify the respective chromatograms. In order to confirm the hypothesis as to the microcrystalline nature of silica gel used in liquid chromatography, it was further investigated through circular dichroism (CD and the data thereof confirmed that the ‘chromatographic’ silica gels are not amorphous but microcrystalline, contributing to the (partial horizontal enantioseparation of the antimer pairs. This paper summarizes the results of our investigation on the microcrystalline nature of silica gels used in planar chromatography and their impact on enantioseparation of the selected pairs of antimers.

  17. Corner Separation Control by Boundary Layer Suction Applied to a Highly Loaded Axial Compressor Cascade

    Directory of Open Access Journals (Sweden)

    Yangwei Liu

    2014-11-01

    Full Text Available Control of corner separation has attracted much interest due to its improvement of performance and energy utilization in turbomachinery. Numerical studies have been performed under both design and off-design flow conditions to investigate the effects of boundary layer suction (BLS on corner separation in a highly loaded compressor cascade. Two new BLS slot configurations are proposed and a total of five suction slot configurations were studied and compared. Averaged static pressure rise, exit loss coefficient, passage blockage and flow turning angle have been given and compared systematically over a range of operation incidence angles. Distributions of significant loss removal, blade loading, exit deviation and total pressure loss at 3 degree and 7 degree incidence have also been studied. Under the same suction mass flows of 0.7% of the inlet mass flows, the pitchwise suction slot on the endwall shows a better optimal performance over the whole operation incidence among single suction slots. By using of the new proposed compound slot configuration with one spanwise slot on the blade suction side and one pitchwise slot on the endwall, the maximum reduction of total pressure loss at 7 degree incidence can be 39.4%.

  18. Investigation of void formation beneath thin AlN layers by decomposition of sapphire substrates for self-separation of thick AlN layers grown by HVPE

    Science.gov (United States)

    Kumagai, Yoshinao; Enatsu, Yuuki; Ishizuki, Masanari; Kubota, Yuki; Tajima, Jumpei; Nagashima, Toru; Murakami, Hisashi; Takada, Kazuya; Koukitu, Akinori

    2010-09-01

    Void formation at the interface between thick AlN layers and (0 0 0 1) sapphire substrates was investigated to form a predefined separation point of the thick AlN layers for the preparation of freestanding AlN substrates by hydride vapor phase epitaxy (HVPE). By heating 50-200 nm thick intermediate AlN layers above 1400 °C in a gas flow containing H 2 and NH 3, voids were formed beneath the AlN layers by the decomposition reaction of sapphire with hydrogen diffusing to the interface. The volume of the sapphire decomposed at the interface increased as the temperature and time of the heat treatment was increased and as the thickness of the AlN layer decreased. Thick AlN layers subsequently grown at 1450 °C after the formation of voids beneath the intermediate AlN layer with a thickness of 100 nm or above self-separated from the sapphire substrates during post-growth cooling with the aid of voids. The 79 μm thick freestanding AlN substrate obtained using a 200 nm thick intermediate AlN layer had a flat surface with no pits, high optical transparency at wavelengths above 208.1 nm, and a dislocation density of 1.5×10 8 cm -2.

  19. Separation of transition and heavy metals using stationary phase gradients and thin layer chromatography.

    Science.gov (United States)

    Stegall, Stacy L; Ashraf, Kayesh M; Moye, Julie R; Higgins, Daniel A; Collinson, Maryanne M

    2016-05-13

    Stationary phase gradients for chelation thin layer chromatography (TLC) have been investigated as a tool to separate a mixture of metal ions. The gradient stationary phases were prepared using controlled rate infusion (CRI) from precursors containing mono-, bi-, and tri-dentate ligands, specifically 3-aminopropyltriethoxysilane, N-[3-(trimethoxysilyl)propyl] ethylenediamine, and N-[3-(trimethoxysilyl)propyl] diethylenetriamine. The presence and the extent of gradient formation were confirmed using N1s X-ray photoelectron spectroscopy (XPS). XPS results showed that the degree of modification was dependent on the aminosilane precursor, its concentration, and the rate of infusion. The separation of four transition and heavy metals (Co(2+), Pb(2+), Cu(2+), and Fe(3+)) on gradient and uniformly modified plates was compared using a mobile phase containing a stronger chelating agent, ethylenediaminetetraacetic acid (EDTA). The retention of the metal ions was manipulated by varying the surface concentration of the chelating ligands. The order of retention on unmodified plates and on plates modified with a monodentate ligand was Fe(3+)>Cu(2+)∼Pb(2+)∼Co(2+), while the order of retention on plates modified with bi- and tri-dentate ligands was Fe(3+)>Cu(2+)>Pb(2+)∼Co(2+). Fe(3+) and Cu(2+) were much more sensitive to the concentration of chelating ligand on the surface (displaying lower Rf values with increasing ligand concentration) than Pb(2+) and Co(2+). Complete separation was achieved using a high concentration of the tridentate ligand coupled with a longer time for modification, yielding a retention order of Fe(3+)>Cu(2+)>Co(2+)>Pb(2+). Copyright © 2016 Elsevier B.V. All rights reserved.

  20. An ODE for boundary layer separation on a sphere and a hyperbolic space

    Science.gov (United States)

    Chan, Chi Hin; Czubak, Magdalena; Yoneda, Tsuyoshi

    2014-07-01

    Ma and Wang derived an equation linking the separation location and times for the boundary layer separation of incompressible fluid flows. The equation gave a necessary condition for the separation (bifurcation) point. The purpose of this paper is to generalize the equation to other geometries, and to phrase it as a simple ODE. Moreover we consider the Navie-Stokes equation with the Coriolis effect, which is related to the presence of trade winds on Earth. A ∂-singular point (bifurcation point) occurs at t0 iff a function α1(t) satisfies α1(t0)=0. The above result is a generalization of [10] which is considered in the Euclidean space R2. We can regard α1(t), α2(t) and α3(t) as a part of the inflow profile. However η(t) is not. Let us be more precise. Choose p˜∈∂K close to p0∈∂K, and let K˜≔{p∈M-K:d(p,p˜)0. It is reasonable to assume uθ does not grow polynomially for the r direction (this is due to the observation of the "boundary layer", since the flow should be a uniform one away from the boundary). Thus, it should be reasonable to focus on the following two cases: (Poiseuille type profile) -k2α1(t)+2kα2(t)0, α2(t)0, α3(t)0 and dp=Δu on the boundary. Our method can be applied to geophysics, in particular, to the "trade winds" on Earth. The trade winds are the easterly surface winds that can be found in the tropics, within the lower portion of the Earth's atmosphere near the equator. The Coriolis effect is responsible for deflecting the surface air, which flows from subtropical high-pressure belts towards the Equator, towards the west in both hemispheres. In the corollary below, we consider the Navie-Stokes equation with the Coriolis effect on a rotating sphere. The equation is

  1. A chip-type thin-layer electrochemical cell coupled with capillary electrophoresis for online separation of electrode reaction products

    Energy Technology Data Exchange (ETDEWEB)

    He, Jian-Bo, E-mail: jbhe@hfut.edu.cn; Cui, Ting; Zhang, Wen-Wen; Deng, Ning

    2013-07-05

    Graphical abstract: -- Highlights: •A new coupling of thin-layer electrolysis with capillary electrophoresis (CE). •Rapid electrolysis, direct sampling followed by online CE separation. •At least 13 products of quercetin oxidation were separated. •Thermodynamic and kinetic parameters were determined from CE peak areas. -- Abstract: A coupling technique of thin-layer electrolysis with high-performance capillary electrophoresis/UV–vis technique(EC/HPCE/UV–vis) is developed for online separation and determination of electrode reaction products. A chip-type thin-layer electrolytic (CTE) cell was designed and fabricated, which contains a capillary channel and a background electrolyte reservoir, allowing rapid electrolysis, direct sampling and online electrophoretic separation. This chip-type setup was characterized based on an electrophoresis expression of Nernst equation that was applied to the redox equilibrium of o-tolidine at different potentials. The utility of the method was demonstrated by separating and determining the electro-oxidation products of quercetin in different pH media. Two main products were always found in the studied time, potential and pH ranges. The variety of products increased not only with increasing potential but also with increasing pH value, and in total, at least 13 products were observed in the electropherograms. This work illustrates a novel example of capillary electrophoresis used online with thin-layer electrolysis to separate and detect electrode reaction products.

  2. Monolithic Superhydrophobic Polymer Layer with Photopatterned Virtual Channel for the Separation of Peptides Using Two-Dimensional Thin Layer Chromatography-Desorption Electrospray Ionization Mass Spectrometry

    Science.gov (United States)

    Han, Yehua; Levkin, Pavel; Abarientos, Irene; Liu, Huwei; Svec, Frantisek; Fréchet, Jean M.J.

    2010-01-01

    Superhydrophobic monolithic porous polymer layers with a photopatterned hydrophilic channel have been prepared. These layers were used for two-dimensional thin layer chromatography of peptides. The 50 μm thin poly(butyl methacrylate-co-ethylene dimethacrylate) layers supported onto 4.0 × 3.3 cm glass plates were prepared using UV-initiated polymerization in a simple glass mold. Photografting of a mixture of 2-acrylamido-2-methyl-1-propanesulfonic acid and 2-hydroxyethyl methacrylate carried out through a mask afforded a 600 μm wide virtual channel along one side of the layer. This channel, which contains ionizable functionalities, enabled the first dimension separation in ion exchange mode. The aqueous mobile phase migrates only through the channel due to the large difference in surface tension at the interface of the hydrophilic channel and the superhydrophobic monolith. The unmodified part of the layer featuring hydrophobic chemistry was then used for the reversed phase separation in the orthogonal second dimension. Practical application of our technique was demonstrated with a rapid 2D separation of a mixture of model peptides differing in hydrophobicity and isoelectric point using a combination of ion-exchange and reversed phase modes. In the former mode, the peptides migrated 11 mm in less than 1 min. Detection of fluorescently labeled peptides was achieved through UV light visualization. Separation of the native peptides was monitored directly using a desorption electrospray ionization (DESI) source coupled to a mass spectrometer. Unidirectional surface scanning with the DESI source was found suitable to determine both the location of each separated peptide and its molecular mass. PMID:20151661

  3. Spot morphology of non-contact printed protein molecules on non-porous substrates with a range of hydrophobicities

    NARCIS (Netherlands)

    Mujawar, L.H.; Norde, W.; Amerongen, van A.

    2013-01-01

    Non-contact inkjet printing technology is one of the most promising tools for producing microarrays. The quality of the microarray depends on the type of the substrate used for printing biomolecules. Various porous and non-porous substrates have been used in the past, but due to low production cost

  4. Spot morphology of non-contact printed protein molecules on non-porous substrates with a range of hydrophobicities

    NARCIS (Netherlands)

    Mujawar, L.H.; Norde, W.; Amerongen, van A.

    2013-01-01

    Non-contact inkjet printing technology is one of the most promising tools for producing microarrays. The quality of the microarray depends on the type of the substrate used for printing biomolecules. Various porous and non-porous substrates have been used in the past, but due to low production cost

  5. Large-eddy simulation of separation and reattachment of a flat plate turbulent boundary layer

    KAUST Repository

    Cheng, W.

    2015-11-11

    © 2015 Cambridge University Press. We present large-eddy simulations (LES) of separation and reattachment of a flat-plate turbulent boundary-layer flow. Instead of resolving the near wall region, we develop a two-dimensional virtual wall model which can calculate the time- and space-dependent skin-friction vector field at the wall, at the resolved scale. By combining the virtual-wall model with the stretched-vortex subgrid-scale (SGS) model, we construct a self-consistent framework for the LES of separating and reattaching turbulent wall-bounded flows at large Reynolds numbers. The present LES methodology is applied to two different experimental flows designed to produce separation/reattachment of a flat-plate turbulent boundary layer at medium Reynolds number Reθ based on the momentum boundary-layer thickness θ. Comparison with data from the first case at demonstrates the present capability for accurate calculation of the variation, with the streamwise co-ordinate up to separation, of the skin friction coefficient, Reθ, the boundary-layer shape factor and a non-dimensional pressure-gradient parameter. Additionally the main large-scale features of the separation bubble, including the mean streamwise velocity profiles, show good agreement with experiment. At the larger Reθ = 11000 of the second case, the LES provides good postdiction of the measured skin-friction variation along the whole streamwise extent of the experiment, consisting of a very strong adverse pressure gradient leading to separation within the separation bubble itself, and in the recovering or reattachment region of strongly-favourable pressure gradient. Overall, the present two-dimensional wall model used in LES appears to be capable of capturing the quantitative features of a separation-reattachment turbulent boundary-layer flow at low to moderately large Reynolds numbers.

  6. Experimental investigation of separated shear layer from a leading edge subjected to various angles of attack with tail flap deflections

    Indian Academy of Sciences (India)

    K Anand; S Sarkar

    2015-05-01

    Shear layer development over a thick flat plate with a semi-circular leading edge is investigated for a range of angles of attack under different pressure gradients for a Reynolds number of 2.44×105 (based on chord and free-stream velocity). The characteristics of the separated shear layer are very well documented through a combination of surface pressure measurement and smoke flow visualization. The instability of the separated layer occurs because of enhanced receptivity of perturbations leading to the development of significant unsteadiness and three-dimensional motions in the second-half of the bubble. The onset of separation, transition and the point of reattachment are identified for varying angles of attack and pressure gradients imposed by tail flap deflections. The data concerning bubble length, laminar portion and reattachment points agree well with the literature.

  7. High-rate/high-temperature capability of a single-layer zicar-separator nickel-hydrogen cell

    Science.gov (United States)

    Wheeler, James R.

    1995-01-01

    A 50 Ampere-hour nickel-hydrogen cell with a single-layer Zircar separator stack design was fully charged and then discharged at a 2C current rate to an end voltage of 1 volt. This extreme test resulted in high temperatures which were recorded at three locations on the cell, i.e., the cell wall, the boss (barrel of the compression seal), and a terminal. The results provide new information about the high-temperature and high-discharge-rate capabilities of nickel-hydrogen cells. This information also adds to the growing data base for single-layer zirconium-oxide-cloth (Zircar) separator cell designs.

  8. Coulomb screening effects on the optoelectronic far-infrared properties of spatially separated few-layer graphene

    Science.gov (United States)

    Yang, C. H.; Wan, P.; Li, Q. F.; Ao, Z. M.

    2016-10-01

    We investigate the longitudinal optical conductivity of spatially separated few-layer graphene analytically and numerically. Each layer could be monolayer or bilayer graphene. The density-density correlation function has been screened by the dielectric function using the random phase approximation, which includes the inter-layer Coulomb coupling. In the presence of the potential function between the layers, the carrier densities in each layer can be tuned respectively. In these two-dimensional layered structures, the main contributions to the optical conductivity are from the intra- and inter-band transition channels in a same layer. In the infrared region, the Drude optical conductivity was observed by the unscreened intra-band transition process. But in the presence of the inter-layer Coulomb interaction, one peak structure of the optical conductivity is observed which can be modified by the dielectric environment. From the number of turning points and the turning positions, the carrier density, the Fermi wavevector, and the layered structure can be determined.

  9. Diffusion and Clustering of Carbon Dioxide on non-porous Amorphous Solid Water

    CERN Document Server

    He, Jiao; Vidali, Gianfranco

    2016-01-01

    Observations by ISO and Spitzer towards young stellar objects (YSOs) showed that CO$_2$ segregates in the icy mantles covering dust grains. Thermal processing of ice mixture was proposed as responsible for the segregation. Although several laboratory studied thermally induced segregation, a satisfying quantification is still missing. We propose that the diffusion of CO$_2$ along pores inside water ice is the key to quantify segregation. We combined Temperature Programmed Desorption (TPD) and Reflection Absorption InfraRed Spectroscopy (RAIRS) to study how CO$_2$ molecules interact on a non-porous amorphous solid water (np-ASW) surface. We found that CO$_2$ diffuses significantly on a np-ASW surface above 65~K and clusters are formed at well below one monolayer. A simple rate equation simulation finds that the diffusion energy barrier of CO$_2$ on np-ASW is 2150$\\pm$50 K, assuming a diffusion pre-exponential factor of 10$^{12}$ s$^{-1}$. This energy should also apply to the diffusion of CO$_2$ on wall of pores...

  10. The biocompatibility of porous vs non-porous bone cements: a new methodological approach

    Directory of Open Access Journals (Sweden)

    C. Dall'Oca

    2014-06-01

    Full Text Available Composite cements have been shown to be biocompatible, bioactive, with good mechanical properties and capability to bind to the bone. Despite these interesting characteristic, in vivo studies on animal models are still incomplete and ultrastructural data are lacking. The acquisition of new ultrastructural data is hampered by uncertainties in the methods of preparation of histological samples due to the use of resins that melt methacrylate present in bone cement composition. A new porous acrylic cement composed of polymethylmetacrylate (PMMA and β-tricalciumphosphate (β-TCP was developed and tested on an animal model. The cement was implanted in femurs of 8 New Zealand White rabbits, which were observed for 8 weeks before their sacrifice. Histological samples were prepared with an infiltration process of LR white resin and then the specimens were studied by X-rays, histology and scanning electron microscopy (SEM. As a control, an acrylic standard cement, commonly used in clinical procedures, was chosen. Radiographic ultrastructural and histological exams have allowed finding an excellent biocompatibility of the new porous cement. The high degree of osteointegration was demonstrated by growth of neo-created bone tissue inside the cement sample. Local or systemic toxicity signs were not detected. The present work shows that the proposed procedure for the evaluation of biocompatibility, based on the use of LR white resin allows to make a thorough and objective assessment of the biocompatibility of porous and non-porous bone cements.

  11. A potential-flow/boundary-layer method for calculating subsonic and transonic airfoil flow with trailing-edge separation

    Science.gov (United States)

    Barnwell, R. W.

    1981-01-01

    The development of a potential-flow/boundary-layer method for calculating subsonic and transonic turbulent flow past airfoils with trailing-edge separation is reported. A moment-of-momentum integral boundary-layer method is used which employs the law-of-the-wall/law-of-the-wake velocity profile and a two-layer eddy-viscosity model and ignores the laminar sublayer. All integrals across the boundary layer are obtained in closed form. Separation is assumed to occur when the shearing-stress velocity vanishes. A closed-form solution is derived for separated-flow regions where the shearing stress is negligible. In the potential-flow method, the exact form of the airfoil boundary condition is used, but it is applied at the chord line rather than the airfoil surface. This allows the accurate computation of flow about airfoils at large angles of attack but permits the use of body-oriented Cartesian computational grids. The governing equation for the perturbation velocity potential contains several terms in addition to the classical small-disturbance terms.

  12. Thin-layer chromatographic specification and separation of Cu(1+), Cu(2+), Ni(2+), and Co(2+) cations.

    Science.gov (United States)

    Savasci, Sahin; Akçay, Mehmet; Ergül, Soner

    2010-07-01

    The M(PyDTC)(2) (M: Cu, Co, or Ni) and CuPyDTC complexes, prepared by reactions of ammonium pyrrolidinedithiocarbamate with metal nitrates, are examined for qualitative analysis, speciation, and mutual separation using thin-layer chromatography systems. These complexes and their mixtures are spotted to the activated and non-activated thin layers of silica gel 60GF(254) (Si-60GF(254)) with a 250-microm thickness. Toluene-dichloromethane mixtures (4:1, 1:1, 1:4 v/v) are used as mobile phases for running of the complexes. All of these chromatographic systems are successfully used for speciation of Cu(2+) and Cu(1+) cations. The best analytical separation for the qualitative analysis of corresponding metal cations and mutual separation of components in M(PyDTC)(2) and CuPyDTC complexes are obtained when using pure toluene-dichloromethane (1:1 v/v) on the activated layer. This study shows that it is possible to qualitatively analyze and satisfactorily separate a mixture of Cu(1+), Cu(2+), Ni(2+), and Co(2+) cations on cited chromatographic systems. These results may be also said for the adaptability or validity on column chromatography.

  13. Separation of pigment formulations by high-performance thin-layer chromatography with automated multiple development.

    Science.gov (United States)

    Stiefel, Constanze; Dietzel, Sylvia; Endress, Marc; Morlock, Gertrud E

    2016-09-02

    Food packaging is designed to provide sufficient protection for the respective filling, legally binding information for the consumers like nutritional facts or filling information, and an attractive appearance to promote the sale. For quality and safety of the package, a regular quality control of the used printing materials is necessary to get consistently good print results, to avoid migration of undesired ink components into the food and to identify potentially faulty ink batches. Analytical approaches, however, have hardly been considered for quality assurance so far due to the lack of robust, suitable methods for the analysis of rarely soluble pigment formulations. Thus, a simple and generic high-performance thin-layer chromatography (HPTLC) method for the separation of different colored pigment formulations was developed on HPTLC plates silica gel 60 by automated multiple development. The gradient system provided a sharp resolution for differently soluble pigment constituents like additives and coating materials. The results of multi-detection allowed a first assignment of the differently detectable bands to particular chemical substance classes (e.g., lipophilic components), enabled the comparison of different commercially available pigment batches and revealed substantial variations in the composition of the batches. Hyphenation of HPTLC with high resolution mass spectrometry and infrared spectroscopy allowed the characterization of single unknown pigment constituents, which may partly be responsible for known quality problems during printing. The newly developed, precise and selective HPTLC method can be used as part of routine quality control for both, incoming pigment batches and monitoring of internal pigment production processes, to secure a consistent pigment composition resulting in consistent ink quality, a faultless print image and safe products. Hyphenation of HPTLC with the A. fischeri bioassay gave first information on the bioactivity or rather

  14. Diffusion and Clustering of Carbon Dioxide on Non-porous Amorphous Solid Water

    Science.gov (United States)

    He, Jiao; Emtiaz, Shahnewaj M.; Vidali, Gianfranco

    2017-03-01

    Observations by ISO and Spitzer toward young stellar objects showed that CO2 segregates in the icy mantles covering dust grains. Thermal processing of the ice mixture was proposed as being responsible for the segregation. Although several laboratories studied thermally induced segregation, a satisfying quantification is still missing. We propose that the diffusion of CO2 along pores inside water ice is the key to quantify segregation. We combined Temperature Programmed Desorption and Reflection Absorption InfraRed Spectroscopy to study how CO2 molecules interact on a non-porous amorphous solid water (np-ASW) surface. We found that CO2 diffuses significantly on an np-ASW surface above 65 K and clusters are formed at well below one monolayer. A simple rate equation simulation finds that the diffusion energy barrier of CO2 on np-ASW is 2150 ± 50 K, assuming a diffusion pre-exponential factor of 1012 s‑1. This energy should also apply to the diffusion of CO2 on the wall of pores. The binding energy of CO2 from CO2 clusters and CO2 from H2O ice has been found to be 2415 ± 20 K and 2250 ± 20 K, respectively, assuming the same prefactor for desorption. CO2–CO2 interaction is stronger than CO2–H2O interaction, in agreement with the experimental finding that CO2 does not wet the np-ASW surface. For comparison, we carried out similar experiments with CO on np-ASW, and found that the CO–CO interaction is always weaker than CO–H2O. As a result, CO wets the np-ASW surface. This study should be of help to uncover the thermal history of CO2 on the icy mantles of dust grains.

  15. Microfluidic Separation of a Soluble Substance Using Transverse Diffusion in a Layered Flow

    Directory of Open Access Journals (Sweden)

    Xuan Don Nguyen

    2016-12-01

    Full Text Available This paper presents a practical flow-through method to separate anisole and ethyl phenylacetate, respectively, from a polystyrene mixture. The microfluidic separation uses different diffusive dynamics of the substances transverse to the lamination flow formed in a microchannel. The effect of inlet flow rates and ambient temperature on separation is examined. Additionally, the possibility of the separation of the light substance from the mixture with different molecular weight is shown numerically and experimentally. The separation efficiency is explained by the facts that the relaxation time depends on the inlet flow rate and that the diffusivity depends on the ambient temperature. This method can be applied to separate monomers from aggregates.

  16. Turbulent boundary layer heat transfer experiments - A separate effects study on a convexly-curved wall

    Science.gov (United States)

    Simon, T. W.; Moffat, R. J.

    1981-01-01

    Surface heat transfer rates have been measured for several different flows on an isothermal, convexly curved surface. The freestream velocity, boundary layer thickness, acceleration parameter, and unheated starting length were varied systematically, and both turbulent and transitional boundary layers were studied. The effect of convex curvature on heat transfer rates is significant with Stanton numbers reduced 20-25% below flat wall values for the same enthalpy thickness Reynolds number. Heat transfer rates recovered slowly on a flat wall downstream of the curved wall, and after 60 cm, the Stanton numbers were still 15-20% below flat wall values. The behavior of the boundary layer suggests the existence of an asymptotic condition. Boundary layer thickness, freestream velocity, and boundary layer maturity affect the initial response to the introduction of curvature and the rate at which the asymptotic state is approached. Convex curvature appears to increase the boundary layer's sensitivity to acceleration; it also delays and retards transition. Near-laminar or early-transitional boundary layers recover from curvature rapidly, whereas late-transitional and mature boundary layers recover slowly.

  17. Investigation of Critical Heat Flux Enhancement for Porous and Non-porous Structures without Surface Wettability Improvement

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Han; Bang, In Cheol [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2014-05-15

    Nanoparticles and nano-sheets have been used in base fluids to enhance the BHT and CHF. Nanoparticles such as Al{sub 2}O{sub 3}, TiO{sub 2}, ZnO, Ag, Au and SiC have been studied for investigating the enhancement in the BHT and CHF. Most of the studies illustrated the enhancement in the heat transfer and CHF based on nanoparticle deposition during boiling occurrences. Research on nanotechnology in boiling experiments such as the deposition of particles on heating surfaces, nanowires, and thin film coatings laid on a substrate was investigated as point of effective heat transfer methods. A theoretical model to predict the CHF based on the dynamic receding contact angle, which includes surface-liquid interaction effects, was accommodated the change of surface wettability due to the deposition of nanoparticles. Park et al., however, reported the reverse results that the enhancement in the CHF could not be explained by the relation of the improved surface wettability. They focused on the change of hydrodynamic instability wavelength due to the deposition of nanoparticles and concluded that the change of instability wavelength could be considered as the CHF enhancement mechanism. Therefore, an experimental CHF study without the change of surface wettability should be conducted to define the parameters attributing to the CHF. This paper presents a study on the enhancement BHT and CHF with porous and non-porous surfaces deposited on a bare indium tin oxide (ITO) surface using FC-72 refrigerant. Plasma enhanced chemical vapor deposition (PECVD) system was applied to deposit the SiC surface as non-porous structure and porous SiC-coated surface was manufactured by deposition of nanoparticles. For graphene surface, rapid thermal annealing (RTA) method and nanoparticles of graphene oxide were used for non-porous and porous structure, respectively. In the present work the study of the BHT and CHF is conducted using non-porous and porous heater surfaces without the effect of

  18. Many-body correlation effects in the spatially separated electron and hole layers in the coupled quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Babichenko, V.S. [RRC Kurchatov Institute, Kurchatov Sq., 1, 123182 Moscow (Russian Federation); Polishchuk, I.Ya., E-mail: iyppolishchuk@gmail.com [RRC Kurchatov Institute, Kurchatov Sq., 1, 123182 Moscow (Russian Federation); Moscow Institute of Physics and Technology, 141700, 9, Institutskii per., Dolgoprudny, Moscow Region (Russian Federation)

    2014-11-15

    The many-body correlation effects in the spatially separated electron and hole layers in the coupled quantum wells are investigated. A special case of the many-component electron–hole system is considered. It is shown that if the hole mass is much greater than the electron mass, the negative correlation energy is mainly determined by the holes. The ground state of the system is found to be the 2D electron–hole liquid with the energy smaller than the exciton phase. It is shown that the system decays into the spatially separated neutral electron–hole drops if the initially created charge density in the layers is smaller than the certain critical value n{sub eq}.

  19. Enhanced charge separation by sieve-layer mediation in high-efficiency inorganic-organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Chien-Hung; Lee, Jiun-Haw [Graduate Institute of Photonics and Optoelectronics and Department of Electrical Engineering, National Taiwan University, Taipei (China); Chattopadhyay, Surojit [Institute of Biophotonics, National Yang Ming University, Taipei (China); Hsu, Chia-Wen; Hwang, Jih-Shang [Institute of Optoelectronic Sciences, National Taiwan Ocean University, Keelung (China); Wu, Meng-Hsiu; Chen, Wei-Chao [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei (China); Wu, Chien-Ting; Tseng, Shao-Chin; Chen, Chun-Wei [Department of Material Science and Engineering, National Taiwan University, Taipei (China); Chen, Cheng-Hsuan; Chen, Li-Chyong [Center for Condensed Matter Sciences, National Taiwan University, Taipei (China); Chen, Kuei-Hsien [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei (China); Center for Condensed Matter Sciences, National Taiwan University, Taipei (China)

    2009-02-16

    The introduction of a thin electronic sieve layer of a material with a wide bandgap, such as lithium fluoride (LiF) or silicon oxide (SiO{sub x}), at the inorganic-organic interface of an organic photovoltaic device enhances the charge separation and improves the efficiency by more than an order to a maximum of 6.04%. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  20. Disassembly and physical separation of electric/electronic components layered in printed circuit boards (PCB).

    Science.gov (United States)

    Lee, Jaeryeong; Kim, Youngjin; Lee, Jae-chun

    2012-11-30

    Although printed circuit boards (PCBs) contain various elements, only the major elements (i.e., those with content levels in wt% or over grade) of and precious metals (e.g., Ag, Au, and platinum groups) contained within PCBs can be recycled. To recover other elements from PCBs, the PCBs should be properly disassembled as the first step of the recycling process. The recovery of these other elements would be beneficial for efforts to conserve scarce resources, reuse electric/electronic components (EECs), and eliminate environmental problems. This paper examines the disassembly of EECs from wasted PCBs (WPCBs) and the physical separation of these EECs using a self-designed disassembling apparatus and a 3-step separation process of sieving, magnetic separation, and dense medium separation. The disassembling efficiencies were evaluated by using the ratio of grinding area (E(area)) and the weight ratio of the detached EECs (E(weight)). In the disassembly treatment, these efficiencies were improved with an increase of grinder speed and grinder height. 97.7% (E(area)) and 98% (E(weight)) could be accomplished ultimately by 3 repetitive treatments at a grinder speed of 5500 rpm and a grinder height of 1.5mm. Through a series of physical separations, most groups of the EECs (except for the diode, transistor, and IC chip groups) could be sorted at a relatively high separation efficiency of about 75% or more. To evaluate the separation efficiency with regard to the elemental composition, the distribution ratio (R(dis)) and the concentration ratio (R(conc)) were used. 15 elements could be separated with the highest R(dis) and R(conc) in the same separated division. This result implies that the recyclability of the elements is highly feasible, even though the initial content in EECs is lower than several tens of mg/kg.

  1. Separation of Gases Using Ultra-Thin Porous Layers of Monodisperse Nanoparticles

    Directory of Open Access Journals (Sweden)

    Bubenchikov Mikhail A

    2016-01-01

    Full Text Available The present paper deals with a numerical solution of the two-dimensional problem of helium and methane molecules motion through an ultra-thin layer of a porous material composed of spherical nanoparticles of the same size. The interaction potential “nanoparticle-molecule” is obtained by integrating paired molecular interactions over the nanoparticle volume. Using the method of classical molecular dynamics, permeability of a layer having the size of about 10−8 m is studied.

  2. Monolithic polymer layer with gradient of hydrophobicity for separation of peptides using two-dimensional thin layer chromatography and MALDI-TOF-MS detection.

    Science.gov (United States)

    Urbanova, Iva; Svec, Frantisek

    2011-08-01

    Superhydrophobic monolithic porous polymer layers supported onto glass plates with a gradient of hydrophobicity have been prepared and used for 2-D thin layer chromatography of peptides. The 50 μm-thin poly(glycidyl methacrylate-co-ethylene dimethacrylate) layers prepared using UV-initiated polymerization in a simple mold were first hydrolyzed using dilute sulfuric acid and then hydrophilized via two-step grafting of poly(ethylene glycol) methacrylate to obtain superhydrophilic plates. The hydrophobicity was then formed by photografting of lauryl methacrylate. The exposure to UV light that initiates photografting was spatially controlled using moving shutter that enabled forming of the diagonal gradient of hydrophobicity. This new concept enables the solutes to encounter the gradient for each of the two sequential developments. Practical application of our novel plates was demonstrated with a rapid 2-D separation of a mixture of model peptides gly-tyr, val-tyr-val, leucine enkephalin, and oxytocin in dual reversed-phase mode using different mobile phases in each direction. Detection of fluorescent-labeled peptides was achieved through UV light visualization while separation of native leucine enkephalin and oxytocin was monitored directly using MALDI mass spectrometry. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Spot morphology of non-contact printed protein molecules on non-porous substrates with a range of hydrophobicities.

    Science.gov (United States)

    Mujawar, Liyakat Hamid; Norde, Willem; van Amerongen, Aart

    2013-01-21

    Non-contact inkjet printing technology is one of the most promising tools for producing microarrays. The quality of the microarray depends on the type of the substrate used for printing biomolecules. Various porous and non-porous substrates have been used in the past, but due to low production cost and easy availability, non-porous substrates like glass and plastic are preferred over porous substrates. On these non-porous substrates, obtaining spot uniformity and a high signal to noise ratio is a big challenge. In our research work, we have modified pristine glass slides using various silanes to produce a range of hydrophobic glass substrates. The hydrophobicities of the slides expressed in the contact angle (θ) of a sessile drop of water were 49°, 61°, 75°, 88° and 103°. Using a non-contact inkjet printer, microarrays of biotinylated biomolecules (BSA and IgG) were produced on these modified glass substrates, pristine (untreated) glass and also on HTA polystyrene slides. The uniformity of the spots, reflecting the distribution of the biomolecules in the spots, was analyzed and compared using confocal laser scanning microscopy (CLSM). The quality of the spots was superior on the glass slide with a contact angle of ∼75°. We also investigated the influence of the hydrophobicity of the substrate on a two-step, real diagnostic antibody assay. This nucleic acid microarray immunoassay (NAMIA) for the detection of Staphylococcus aureus showed that on highly hydrophilic (θ 100°) the assay signal was low, whereas an excellent signal was obtained on the substrates with intermediate contact angles, θ ∼ 61° and θ ∼ 75°, respectively.

  4. Separation of the Carotenoid Bixin from Annatto Seeds Using Thin-Layer and Column Chromatography

    Science.gov (United States)

    McCullagh, James V.; Ramos, Nicholas

    2008-01-01

    In this experiment the carotenoid bixin is isolated from annatto ("Bixa orellana") seeds using column chromatography. The experiment has several key advantages over previous pigment separation experiments. First, unlike other experiments significant quantities of the carotenoid (typically 20 to 25 mg) can be isolated from small quantities of plant…

  5. Separation of the Carotenoid Bixin from Annatto Seeds Using Thin-Layer and Column Chromatography

    Science.gov (United States)

    McCullagh, James V.; Ramos, Nicholas

    2008-01-01

    In this experiment the carotenoid bixin is isolated from annatto ("Bixa orellana") seeds using column chromatography. The experiment has several key advantages over previous pigment separation experiments. First, unlike other experiments significant quantities of the carotenoid (typically 20 to 25 mg) can be isolated from small quantities of plant…

  6. Sound field separation with a double layer velocity transducer array (L)

    DEFF Research Database (Denmark)

    Fernandez Grande, Efren; Jacobsen, Finn

    2011-01-01

    In near-field acoustic holography sound field separation techniques make it possible to distinguish between sound coming from the two sides of the array. This is useful in cases where the sources are not confined to only one side of the array, e.g., in the presence of additional sources or reflec...

  7. Accommodative Behavior of Non-porous Molecular crystal at Solid-Gas and Solid-Liquid Interface

    OpenAIRE

    Mande, Hemant M.; Ghalsasi, Prasanna S.

    2015-01-01

    Molecular crystals demonstrate drastically different behavior in solid and liquid state, mainly due to their difference in structural frameworks. Therefore, designing of unique structured molecular compound which can work at both these interfaces has been a challenge. Here, we present remarkable ‘molecular’ property by non-porous molecular solid crystal, dinuclear copper complex (C6H5CH(X)NH2)2CuCl2, to reversibly ‘adsorb’ HCl gas at solid-gas interface as well as ‘accommodate’ azide anion at...

  8. Effect of Hydrograph Separation on Suspended Sediment Concentration Predictions in a Forested Headwater with Thick Soil and Weathered Gneiss Layers

    Directory of Open Access Journals (Sweden)

    Naoki Kabeya

    2014-06-01

    Full Text Available Two-component hydrograph separation using oxygen-18 concentrations was conducted at a sediment runoff observation weir installed in a small subcatchment of a forested gneiss catchment in Japan. The mean soil thickness of this catchment is 7.27 m, which comprises 3.29 m of brown forest soil (A and B layers and a 3.98-m layer of heavily weathered gneiss. Data were collected for a storm on 20–21 May 2003, and the percentage of event water separated by the stable isotope ratio in comparison with the total rainfall amount was about 1%. This value is within the ratio of a riparian zone in a drainage area. Temporal variation of suspended sediment concentration exhibited higher correlation with the event water component than with the total runoff or pre-event water component. This shows that the riparian zone causes rainwater to flow out quickly during a rain event, and that this is an important area of sediment production and transportation in a forested headwater with thick soil and weathered gneiss layers.

  9. Experimental Investigation of Upstream Boundary Layer Acceleration on Unsteadiness of Shock-Induced Separation

    Science.gov (United States)

    2007-11-02

    part of the upstream boundary layer and the shock foot motion. Furthermore, their measurements confirmed the observation that there is no correlation...The “dot card” target is composed of equally spaced dots and a single cross in the lower part of the image (an example image is shown in Fig. 9...University of Tokyo, Hongo Bunkyo-ku, Tokyo 113, Japan, Oct. 25-29, 1987. 12 Figure 1. Schematic diagram of the test section with compression

  10. Plasma treatment of hydrophobic sub-layers to prepare uniform multi-layered films and high-performance gas separation membranes

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Xiuxiu; Kanezashi, Masakoto; Nagasawa, Hiroki; Tsuru, Toshinori, E-mail: tsuru@hiroshima-u.ac.jp

    2015-09-15

    Highlights: • TEOS and BTESE films were improved by coating sols on plasma-treated Me-SiO{sub 2} films. • BTESO sols were well coated on Me-SiO{sub 2} films with and without plasma treatment. • The gas performance of BTESE/Me-SiO{sub 2} membrane was improved with plasma treatment. - Abstract: Uniform and defect-free silica films were prepared by spin-coating silica sols on plasma-treated hydrophobic sub-layers. Three kinds of silica films were prepared using tetraethoxysilane (TEOS), bis(triethoxysilyl)ethane (BTESE) and bis(triethoxysily)octane (BTESO) via sol–gel method. First, hydrophobic sub-layers were pre-coated on silicon wafers with Me-SiO{sub 2} sols prepared from mixtures of methyltrimethoxysilane (MTMS) and TEOS. After firing at 400 °C, the films showed water contact angles of 120°. Then TEOS- and BTESE-derived sols were directly spin-coated on the Me-SiO{sub 2} films, resulting in separated and scattered coatings. A H{sub 2}O/N{sub 2} plasma modification method was used to change the properties of the Me-SiO{sub 2} films from hydrophobicity to hydrophilicity without damaging either the surface morphology or the bulk chemistry. After the treatment, the TEOS- and BTESE-derived sols formed homogenous films. On the other hand, the Me-SiO{sub 2} films were fully coated with BTESO either with or without plasma treatment. This was probably due to both the polar (–OH) and non-polar (long –CH{sub 2}) portions of the BTESO-derived sols. For gas separation applications, the corresponding BTESE membranes showed great improvement in gas selectivity after the plasma treatment of hydrophobic Me-SiO{sub 2} layers.

  11. Formation of separating layers under conditions of the thermal aging of sorbents modified by fluorinated polyimide

    Science.gov (United States)

    Yakovleva, E. Yu.; Shundrina, I. K.; Gerasimov, E. Yu.; Vaganova, T. A.

    2014-03-01

    Thermogravimetry, elemental analysis, low-temperature nitrogen adsorption, high-resolution electron microscopy, and gas chromatography are used to study the effect of the content of perfluorinated polyimide when used as a stationary phase for modifying Chromosorb P NAW diatomite supports and aluminum oxide, and the effect of thermal aging conditions on changes in their texture and chromatographic characteristics. It is shown that Chromosorb P NAW + 5 wt % of polyimide (PI) adsorbent thermally aged at 700°C in a flow of inert gas exhibits properties of carbon molecular sieves, while aluminum oxide impregnated with 10 wt % of PI and thermally aged at 250°C allows us to selectively separate permanent and organic gases, as well separate saturated and unsaturated hydrocarbons.

  12. Separation of eight selected flavan-3-ols on cellulose thin-layer chromatographic plates.

    Science.gov (United States)

    Vovk, Irena; Simonovska, Breda; Vuorela, Heikki

    2005-06-10

    The potential of microcristaline cellulose as sorbent in the separation of eight compounds: (+)-catechin (C), (-)-epicatechin (EC), (-)-gallocatechin (GC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECg), (-)-epigallocatechin gallate (EGCg), procyanidin B1 and procyanidin B2 was studied. Cellulose HPTLC plates prewashed in water (not necessary, when water was used as developing solvent) and dried with a hair dryer, bandwise application and development in horizontal developing chamber (sandwich configuration) gave the best results. Detection was performed using vanillin-H3PO4 reagent. Four new developing solvent systems were proposed: water, 1-propanol-water (20:80, v/v), 1-propanol-water-acetic acid (4:2:1, v/v) and 1-propanol-water-acetic acid (20:80:1, v/v), and at least two of them were needed for the differentiation between all eight compounds. Surprisingly, water enabled the separation of epimers C from EC and GC from EGC, as well as the dimers procianidin B1 and B2. Additionally, C, EGC, B1 and B2 were separated from all the other compounds. The best choice for developing solvent is given for each of the studied compounds. The best separation of the five main catechins (EC, GC, EGC, ECg, EGCg) present in green tea extract was achieved using 1-propanol-water-acetic acid (20:80:1, v/v). The chromatograms of oak bark extract developed in solvents with higher water content (1-propanol-water (1:4, v/v) and 1-propanol-water-acetic acid (20:80:1, v/v)) showed less bands than chromatograms developed in solvents with higher organic modifier content (e.g. 1-propanol-water-acetic acid (4:2:1, v/v)). It was proved that such behavior was due to the presence of procyanidins beside the main component catechin.

  13. Transition to Turbulence in the Separated Shear Layers of Yawed Circular Cylinders

    Science.gov (United States)

    2010-04-15

    where her hot - wire anemometer measurements found their streamwise appearance (after separation) to be inversely proportional to the cylinder Reynolds...Smith (1986) conducted hot - wire anemometer measurements where they reported expo- nents b = 0.87 and b = 0.773, respectively, for the Bloor power- law...measured when using anemometry . Prasad and Wil- liamson (1996) compiled their anemometer measurements along with those of Bloor as well as Wei and

  14. Rational Integration of Polypropylene/Graphene Oxide/Nafion as Ternary-Layered Separator to Retard the Shuttle of Polysulfides for Lithium-Sulfur Batteries.

    Science.gov (United States)

    Zhuang, Ting-Zhou; Huang, Jia-Qi; Peng, Hong-Jie; He, Lian-Yuan; Cheng, Xin-Bing; Chen, Cheng-Meng; Zhang, Qiang

    2016-01-20

    The reversible electrochemical transformation from lithium (Li) and sulfur (S) into Li2 S through multielectron reactions can be utilized in secondary Li-S batteries with very high energy density. However, both the low Coulombic efficiency and severe capacity degradation limits the full utilization of active sulfur, which hinders the practical applications of Li-S battery system. The present study reports a ternary-layered separator with a macroporous polypropylene (PP) matrix layer, graphene oxide (GO) barrier layer, and Nafion retarding layer as the separator for Li-S batteries with high Coulombic efficiency and superior cyclic stability. In the ternary-layered separator, ultrathin layer of GO (0.0032 mg cm(-2) , estimated to be around 40 layers) blocks the macropores of PP matrix, and a dense ion selective Nafion layer with a very low loading amount of 0.05 mg cm(-2) is attached as a retarding layer to suppress the crossover of sulfur-containing species. The ternary-layered separators are effective in improving the initial capacity and the Coulombic efficiency of Li-S cells from 969 to 1057 mAh g(-1) , and from 80% to over 95% with an LiNO3 -free electrolyte, respectively. The capacity degradation is reduced from 0.34% to 0.18% per cycle within 200 cycles when the PP separator is replaced by the ternary-layered separators. This work provides the rational design strategy for multifunctional separators at cell scale to effective utilizing of active sulfur and retarding of polysulfides, which offers the possibility of high energy density Li-S cells with long cycling life.

  15. Analysis of the separated boundary layer flow on the surface and in the wake of blunt trailing edge airfoils

    Science.gov (United States)

    Goradia, S. H.; Mehta, J. M.; Shrewsbury, G. S.

    1977-01-01

    The viscous flow phenomena associated with sharp and blunt trailing edge airfoils were investigated. Experimental measurements were obtained for a 17 percent thick, high performance GAW-1 airfoil. Experimental measurements consist of velocity and static pressure profiles which were obtained by the use of forward and reverse total pressure probes and disc type static pressure probes over the surface and in the wake of sharp and blunt trailing edge airfoils. Measurements of the upper surface boundary layer were obtained in both the attached and separated flow regions. In addition, static pressure data were acquired, and skin friction on the airfoil upper surface was measured with a specially constructed device. Comparison of the viscous flow data with data previously obtained elsewhere indicates reasonable agreement in the attached flow region. In the separated flow region, considerable differences exist between these two sets of measurements.

  16. In situ Silver Spot Preparation and on-Plate Surface-Enhanced Raman Scattering Detection in Thin Layer Chromatography Separation

    Science.gov (United States)

    Herman, K.; Mircescu, N. E.; Szabo, L.; Leopold, L. F.; Chiş, V.; Leopold, N.

    2013-05-01

    An improved approach for surface-enhanced Raman scattering (SERS) detection of mixture constituents after thin layer chromatography (TLC) separation is presented. A SERS active silver substrate was prepared under open air conditions, directly on the thin silica film by photo-reduction of silver nitrate, allowing the detection of binary mixtures of cresyl violet, bixine, crystal violet, and Cu(II) complex of 4-(2-pyridylazo)resorcinol. The recorded SERS spectrum provides a unique spectral fingerprint for each molecule; therefore the use of analyte standards is avoided, thus rendering the presented procedure advantageous compared to the conventional detection methodology in TLC.

  17. Chromatographic separation studies of penicillins, cephalosporins and carbapenems on transition-metal silicate modified silica layers.

    Science.gov (United States)

    Singh, Dhruv K; Maheshwari, Gunjan

    2012-01-01

    The chromatographic behavior of penicillins, cephalosporins and carbapenems has been studied on the thin layers of transition-metal ion (viz. Ni(2+)/Zn(2+)/Cu(2+)/Co(2+)) silicate modified silica. Transition-metal silicate (3.92%) and silica (96.08%) were found to be optimum and resulted in spherical-compact spots and improved resolution of the analytes. The effect of various mobile phases was also investigated. The chromatograms were visualized as yellow spots by placing in an I(2)-chamber. The method has been found to be reproducible and convenient for routine analysis.

  18. In vivo guided vascular regeneration with a non-porous elastin-like polypeptide hydrogel tubular scaffold.

    Science.gov (United States)

    Mahara, Atsushi; Kiick, Kristi L; Yamaoka, Tetsuji

    2017-01-28

    Herein, we demonstrate a new approach for small-caliber vascular reconstruction using a non-porous elastin-like polypeptide hydrogel tubular scaffold, based on the concept of guided vascular regeneration (GVR). The scaffolds are composed of elastin-like polypeptide, (Val-Pro-Gly-Ile-Gly)n , for compliance matching and antithrombogenicity and an Arg-Gly-Asp (RGD) motif for connective tissue regeneration. When the polypeptide was mixed with an aqueous solution of β-[Tris(hydroxymethyl)phosphino]propionic acid at 37°C, the polypeptide hydrogel was rapidly formed. The elastic modulus of the hydrogel was 4.4kPa. The hydrogel tubular scaffold was formed in a mold and reinforced with poly(lactic acid) nanofibers. When tubular scaffolds with an inner diameter of 1 mm and length of 5 mm were implanted into rat abdominal aortae, connective tissue grew along the scaffold luminal surface from the flanking native tissues, resulting in new blood vessel tissue with a thickness of 200 μm in 1 month. In contrast, rats implanted with control scaffolds without the RGD motif died. These results indicate that the non-porous hydrogel tubular scaffold containing the RGD motif effectively induced rapid tissue regeneration and that GVR is a promising strategy for the regeneration of small-diameter blood vessels. This article is protected by copyright. All rights reserved.

  19. Persistence of the 2009 pandemic influenza A (H1N1 virus in water and on non-porous surface.

    Directory of Open Access Journals (Sweden)

    Amélie Dublineau

    Full Text Available Knowledge of influenza A virus survival in different environmental conditions is a key element for the implementation of hygiene and personal protection measures by health authorities. As it is dependent on virus isolates even within the same subtype, we studied the survival of the 2009 H1N1 pandemic (H1N1pdm virus in water and on non-porous surface. The H1N1pdm virus was subjected to various environmental parameters over time and tested for infectivity. In water, at low and medium salinity levels and 4°C, virus survived at least 200 days. Increasing temperature and salinity had a strong negative effect on the survival of the virus which remained infectious no more than 1 day at 35°C and 270 parts per thousand (ppt of salt. Based on modeled data, the H1N1pdm virus retained its infectivity on smooth non-porous surface for at least 7 days at 35°C and up to 66 days at 4°C. The H1N1pdm virus has thus the ability to persist in water and on glass surface for extended periods of time, even at 35°C. Additional experiments suggest that external viral structures in direct contact with the environment are mostly involved in loss of virus infectivity.

  20. Imidazole-Functionalized Fullerene as a Vertically Phase-Separated Cathode Interfacial Layer of Inverted Ternary Polymer Solar Cells.

    Science.gov (United States)

    Li, Dan; Liu, Qing; Zhen, Jieming; Fang, Zhimin; Chen, Xiang; Yang, Shangfeng

    2017-01-25

    By using a facile one-pot nucleophilic addition reaction, we synthesized a novel imidazole (IMZ)-functionalized fullerene (C60-IMZ), and applied it as a third component of inverted ternary polymer solar cells (PSCs), leading to dramatic efficiency enhancement. According to FT-IR, XPS spectroscopic characterizations, and elemental analysis, the chemical structure of C60-IMZ was determined with the average IMZ addition number estimated to be six. The lowest unoccupied molecular orbital (LUMO) level of C60-IMZ measured by cyclic voltammetry was -3.63 eV, which is up-shifted relative to that of 6,6-phenyl C61-butyric acid methyl ester (PC61BM). Upon doping C60-IMZ as a third component into an active layer blend of poly(3-hexylthiophene) (P3HT) and PC61BM, the power conversion efficiency (PCE) of the inverted ternary PSCs was 3.4% under the optimized doping ratio of 10 wt %, dramatically higher than that of the control device ITO/P3HT:PC61BM/MoO3/Ag based on the binary P3HT:PC61BM blend (1.3%). The incorporation of C60-IMZ results in enhancement of the absorption of P3HT:PC61BM blend film, increase of the electron mobility of the device, and rougher film surface of the P3HT:PC61BM active layer beneficial for interfacial contact with the Ag anode. Furthermore, C60-IMZ doped in P3HT:PC61BM blend may migrate to the surface of ITO cathode via vertical phase separation as revealed by XPS depth analysis, consequently forming a cathode interfacial layer (CIL), which can lower the work function (WF) of ITO cathode. Thus, the interfacial contact between the active layer and ITO cathode is improved, facilitating electron transport from the active layer to ITO cathode. The effectiveness of C60-IMZ as a vertically phase-separated CIL on efficiency enhancement of inverted ternary PSCs is further verified by doping it into another active layer system comprised of a low-bandgap conjugated polymer, poly(thieno[3,4-b]-thiophene/benzodithiophene) (PTB7), blended with [6,6]-phenyl C71

  1. Spatially Distributed Forcing for Boundary Layer Separation Control on a Wall Mounted Hump

    Science.gov (United States)

    Borgmann, David; Little, Jesse; Woszidlo, Rene

    2016-11-01

    Numerous successful efforts on controlling flow separation have been demonstrated using spatially distributed actuators. These include both steady and unsteady forcing from discrete locations in the vicinity of separation. Despite this, there are many open questions on the actual flow control mechanism. A canonical hump model is used to investigate these physics in a subsonic wind tunnel. Reynolds number independence is achieved above 0.72 ×106 and testing is performed up to 2.2 ×106. The efficacy of discrete steady jets is studied as a function of spacing, momentum coefficient, velocity ratio and mass flux. Highly-resolved surface pressure data for the controlled flow are compared to an inviscid solution establishing a figure of merit. Results indicate the inviscid limit is reached for a momentum coefficient of 1% with actuator spacing of 0.5% span. A comparison of steady discrete jets with sweeping jets actuators of equivalent cross-sectional area is undertaken. Surface flow visualization and PIV are employed to extract detailed information on the baseline and controlled flow field. This importance of establishing critical baseline features is also discussed with respect to establishing proper boundary conditions for accompanying numerical simulations. Supported by The Boeing Company.

  2. Passive Boundary Layer Separation Control on a NACA2415 Airfoil at High Reynolds Numbers

    Science.gov (United States)

    Parikh, Agastya; Hultmark, Marcus

    2016-11-01

    The design and analysis of a passive flow control system for a NACA2415 airfoil is undertaken. There exists a vast body of knowledge on airfoil boundary layer control with the use of controlled mass flux, but there is little work investigating passive mass flux-based methods. A simple duct system that uses the upper surface pressure gradient to force blowing near the leading edge and suction near the trailing edge is proposed and evaluated. 2D RANS analyses at Rec 1 . 27 ×106 were used to generate potential configurations for experimental tests. Initial computational results suggest drag reductions of approximately 2 - 7 % as well as lift increases of 4 - 5 % at α = 10 .0° and α = 12 .5° . A carbon composite-aluminum structure model that implements the most effective configurations, according to the CFD predictions, has been designed and fabricated. Experiments are being performed to evaluate the CFD results and the feasibility the duct system.

  3. HYDROPHILIC NANOFILTRATION MEMBRANES WITH SELF-POLYMERIZED AND STRONGLY-ADHERED POLYDOPAMINE AS SEPARATING LAYER

    Institute of Scientific and Technical Information of China (English)

    Xiao-lin Li; Li-ping Zhu; Jin-hong Jiang; Zhuan Yi; Bao-ku Zhu; You-yi Xu

    2012-01-01

    Inspired by the self-polymerization and strong adhesion characteristics of dopamine in aqueous conditions,a novel hydrophilic nanofiltration (NF) membrane was fabricated by simply dipping polysulfone (PSf) ultrafiltration (UF) substrate in dopamine solution.The changes in surface chemical composition and morphology of membranes were determined by Fourier transform infrared spectroscopy (FTIR-ATR),X-ray photoelectron spectroscopy (XPS),scanning electron microscopy (SEM) and atomic force microscopy (AFM).The experimental results indicated that the self-polymerized dopamine formed an ultrathin and defect-free barrier layer on the PSf UF membrane.The surface hydrophilicity of membranes was evaluated through water contact angle measurements.It was found that membrane hydrophilicity was significantly improved after coating a polydopamine (pDA) layer,especially after double coating.The dyes filtration experiments showed that the double-coated membranes were able to reject completely the dyes of brilliant blue,congo red and methyl orange with a pure water flux of 83.7 L/(m2·h) under 0.6 MPa.The zeta potential determination revealed the positively-charged characteristics of PSf/pDA composite membrane in NF process.The salt rejection of the membranes was characterized by 0.01 mmol/L of salts filtration experiment.It was demonstrated that the salts rejections followed the sequence:NaCl < Na2SO4 < MgSO4 < MgCl2 < CaCl2,and the rejection to CaCl2 reached 68.7%.Moreover,the composite NF membranes showed a good stability in water-phase filtration process.

  4. Numerical simulation and experimental visualization of the separated cavitating boundary layer over NACA2412

    Directory of Open Access Journals (Sweden)

    Kozák Jiří

    2015-01-01

    Full Text Available Cavitation is physical phenomenon of crucial impact on the operation range and service lifetime of the hydraulic machines (pumps, turbines, valves etc.. Experimental measurement of cavitation is expensive and time consuming process, while some important characteristic of the flow are difficult to measure due to the nature of the phenomenon. Current possibilities of computational fluid dynamics provide a way for deeper understanding of cavitation which is important for many applications in the hydraulic machines industry such as expanding operation range or extending lifetime of the hydraulic machines. Simplified model consists of NACA 2412 hydrofoil with 8 degrees angle of attack fixed in between the walls of cavitation tunnel. Present investigation focuses on comparison of vapor volume fractions obtained by 3D CFD simulations and high speed visualization of the real cavitation phenomena. Several operating regimes corresponding to different cavitation numbers are studied with aim to assess the dynamics of the separated cavitating sheets/clouds

  5. Aerodynamics of wings at low Reynolds numbers: Boundary layer separation and reattachment

    Science.gov (United States)

    McArthur, John

    Due to advances in electronics technology, it is now possible to build small scale flying and swimming vehicles. These vehicles will have size and velocity scales similar to small birds and fish, and their characteristic Reynolds number will be between 104 and 105. Currently, these flying and swimming vehicles do not perform well, and very little research has been done to characterize them, or to explain why they perform so poorly. This dissertation documents three basic investigations into the performance of small scale lifting surfaces, with Reynolds numbers near 104. Part I. Low Reynolds number aerodynamics. Three airfoil shapes were studied at Reynolds numbers of 1 and 2x104: a flat plate airfoil, a circular arc cambered airfoil, and the Eppler 387 airfoil. Lift and drag force measurements were made on both 2D and 3D conditions, with the 3D wings having an aspect ratio of 6, and the 2D condition being approximated by placing end plates at the wing tips. Comparisons to the limited number of previous measurements show adequate agreement. Previous studies have been inconclusive on whether lifting line theory can be applied to this range of Re, but this study shows that lifting line theory can be applied when there are no sudden changes in the slope of the force curves. This is highly dependent on the airfoil shape of the wing, and explains why previous studies have been inconclusive. Part II. The laminar separation bubble. The Eppler 387 airfoil was studied at two higher Reynolds numbers: 3 and 6x10 4. Previous studies at a Reynolds number of 6x104 had shown this airfoil experiences a drag increase at moderate lift, and a subsequent drag decrease at high lift. Previous studies suggested that the drag increase is caused by a laminar separation bubble, but the experiments used to show this were conducted at higher Reynolds numbers and extrapolated down. Force measurements were combined with flow field measurements at Reynolds numbers 3 and 6x104 to determine whether

  6. Thermal separation in near-axis boundary layers with intense swirl

    Science.gov (United States)

    Herrada, M. A.; Pérez-Saborid, M.; Barrero, A.

    1999-12-01

    Swirling flows have a wide range of applications and exhibit a variety of interesting features. Gas cooling near the axis in these flows, the so-called Ranque-Hilsch effect, is one of them. To gain insight into this phenomenon, we have analyzed the thermal, near-axis boundary layer of a gas jet driven by a class of conical inviscid quasi-incompressible flows whose axial and azimuthal velocity components, w and v, and stagnation temperature, Tt, behave near the axis as w=W0rm-2,v=LW0rm-2, and Tt-Tr=T0r2(m-2), where z and r are the axial and radial coordinates, L is the Squire number directly related to the swirl strength, m is any real number such as 1⩽mvortex core for some range of values of both L and Pr (Ranque-Hilsch effect) when the effect of both heat conduction and the work done by viscous forces are taken into account. It is also found that there exists an optimum value Lop for which the cooling effect reaches a sharp maximum and that small deviations of L from Lop reduce drastically the cooling effect. The appropriate tuning of Lop can be dramatically important for the efficient operation of Ranque-Hilsch tubes. The influence of the Prandtl number and the rest of the parameters of the problem has been also considered.

  7. Effect of silica nanoparticles/poly(vinylidene fluoride-hexafluoropropylene) coated layers on the performance of polypropylene separator for lithium-ion batteries

    Institute of Scientific and Technical Information of China (English)

    Hongyu Liu; Zehui Dai; Jun Xu; Baohua Guo; Xiangming He

    2014-01-01

    In an effort to reduce thermal shrinkage and improve electrochemical performance of porous polypropylene (PP) separators for lithium-ion batteries, a new composite separator is developed by introducing ceramic coated layers on both sides of PP separator through a dip-coating process. The coated layers are comprised of heat-resistant and hydrophilic silica nanoparticles and polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) binders. Highly porous honeycomb structure is formed and the thickness of the layer is only about 700 nm. In comparison to the pristine PP separator, the composite separator shows significant reduction in thermal shrinkage and improvement in liquid electrolyte uptake and ionic conduction, which play an important role in improving cell performance such as discharge capacity, C-rate capability, cycle performance and coulombic efficiency.

  8. Flowing atmospheric pressure afterglow combined with laser ablation for direct analysis of compounds separated by thin-layer chromatography.

    Science.gov (United States)

    Cegłowski, Michał; Smoluch, Marek; Reszke, Edward; Silberring, Jerzy; Schroeder, Grzegorz

    2016-01-01

    A thin-layer chromatography-mass spectrometry (TLC-MS) setup for characterization of low molecular weight compounds separated on standard TLC plates has been constructed. This new approach successfully combines TLC separation, laser ablation, and ionization using flowing atmospheric pressure afterglow (FAPA) source. For the laser ablation, a low-priced 445-nm continuous-wave diode laser pointer, with a power of 1 W, was used. The combination of the simple, low-budget laser pointer and the FAPA ion source has made this experimental arrangement broadly available, also for small laboratories. The approach was successfully applied for the characterization of low molecular weight compounds separated on TLC plates, such as a mixture of pyrazole derivatives, alkaloids (nicotine and sparteine), and an extract from a drug tablet consisting of paracetamol, propyphenazone, and caffeine. The laser pointer used was capable of ablating organic compounds without the need of application of any additional substances (matrices, staining, etc.) on the TLC spots. The detection limit of the proposed method was estimated to be 35 ng/cm(2) of a pyrazole derivative.

  9. Organic phototransistors with nanoscale phase-separated polymer/polymer bulk heterojunction layers.

    Science.gov (United States)

    Hwang, Hyemin; Kim, Hwajeong; Nam, Sungho; Bradley, Donal D C; Ha, Chang-Sik; Kim, Youngkyoo

    2011-05-01

    Low-cost detectors for sensing photons at a low light intensity are of crucial importance in modern science. Phototransistors can deliver better signals of low-intensity light by electrical amplification, but conventional inorganic phototransistors have a limitation owing to their high temperature processes in vacuum. In this work, we demonstrate organic phototransistors with polymer/polymer bulk heterojunction blend films (mixtures of p-type and n-type semiconducting polymers), which can be fabricated by inexpensive solution processes at room temperature. The key idea here is to effectively exploit hole charges (from p-type polymer) as major signaling carriers by employing p-type transistor geometry, while the n-type polymer helps efficient charge separation from excitons generated by incoming photons. Results showed that the present organic transistors exhibited proper functions as p-type phototransistors with ∼4.3 A W(-1) responsivity at a low light intensity (1 µW cm(-2)), which supports their encouraging potential to replace conventional cooled charge coupled devices (CCD) for low-intensity light detection applications.

  10. Parcels and Land Ownership, Separate county layers for an eleven county region. Each layer uses a common field structure. The same information is not available for all counties., Published in 2007, NC Dept of Commerce - DCA.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Parcels and Land Ownership dataset, was produced all or in part from Other information as of 2007. It is described as 'Separate county layers for an eleven...

  11. Ion Exchange and Thin Layer Chromatographic Separation and Identification of Amino Acids in a Mixture: An Experiment for General Chemistry and Biotechnology Laboratories

    Science.gov (United States)

    Brunauer, Linda S.; Caslavka, Katelyn E.; Van Groningen, Karinne

    2014-01-01

    A multiday laboratory exercise is described that is suitable for first-year undergraduate chemistry, biochemistry, or biotechnology students. Students gain experience in performing chromatographic separations of biomolecules, in both a column and thin layer chromatography (TLC) format. Students chromatographically separate amino acids (AA) in an…

  12. Ion Exchange and Thin Layer Chromatographic Separation and Identification of Amino Acids in a Mixture: An Experiment for General Chemistry and Biotechnology Laboratories

    Science.gov (United States)

    Brunauer, Linda S.; Caslavka, Katelyn E.; Van Groningen, Karinne

    2014-01-01

    A multiday laboratory exercise is described that is suitable for first-year undergraduate chemistry, biochemistry, or biotechnology students. Students gain experience in performing chromatographic separations of biomolecules, in both a column and thin layer chromatography (TLC) format. Students chromatographically separate amino acids (AA) in an…

  13. Silica-decorated polypropylene microfiltration membranes with a mussel-inspired intermediate layer for oil-in-water emulsion separation.

    Science.gov (United States)

    Yang, Hao-Cheng; Pi, Jun-Ke; Liao, Kun-Jian; Huang, He; Wu, Qing-Yun; Huang, Xiao-Jun; Xu, Zhi-Kang

    2014-08-13

    Silica-decorated polypropylene microfiltration membranes were fabricated via a facile biomimetic silicification process on the polydopamine/polyethylenimine-modified surfaces. The membranes exhibit superhydrophilicity and underwater superoleophobicity derived from the inherent hydrophilicity and the well-defined micronanocomposite structures of the silica-decorated surfaces. They can be applied in varieties of oil-in-water emulsions separation with high permeate flux (above 1200 L/m(2)h under 0.04 MPa) and oil rejection (above 99%). The membranes also have relatively high oil breakthrough pressure reaching 0.16 MPa due to the microporous structure, showing great potential for practical applications. Furthermore, such mussel-inspired intermediate layer provides us a convenient and powerful tool to fabricate organic-inorganic hybrid membranes for advanced applications.

  14. Separation of Berberine Hydrochloride and Tetrahydropalmatine and Their Quantitative Analysis with Thin Layer Chromatography Involved with Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Jing Lu

    2015-01-01

    Full Text Available [BMIM]OH was used in mobile and stationary phase of thin layer chromatography (TLC to analyze berberine hydrochloride and tetrahydropalmatine for the first time. Supported imidazole ionic liquid with hydroxide ion on silica gel (SiO2·Im+·OH− was synthesized through simple procedure and characterized by Fourier transform infrared spectroscopy (FT-IR, elemental analysis, and scanning electron microscope (SEM. Moreover, on the plates prepared by SiO2·Im+·OH−, the contents of the above alkaloids in the Chinese patent medicine (CPM of “Stomacheasy” capsule were successfully determined by TLC scanner. The key conditions and chromatographic behaviors were also investigated in detail. According to similar ways, ionic liquids (ILs also can be used in other planar chromatographies in two modes. This study is expected to be helpful in expanding the application of IL and its bonded silica gel in TLC separation field.

  15. STUDY ON THE SEPARATION THROUGH THIN LAYER CHROMATOGRAPHY OF THE CHOLESTEROL IN THE BUFFALO MILK ORIGINATING IN THE MESENDORF FARM

    Directory of Open Access Journals (Sweden)

    AURELIA PECE

    2013-12-01

    Full Text Available Within the present study, we conducted a thin layer chromatographic separation of neuter fats in buffalo milk, following sodium metoxyde saponification and the exposition to λ=366 nm. The extraction of free and esterized milk cholesterol was conducted according to the Folch et al. (1957 method. The free and esterized cholesterol, as well as triglycerids appear as brown spots (iodine complexes with the double connections between the compounds under anlysis. Qualitative identification was conducted through the comparison of Rfs for free and esterized cholesterol, in the samples analyzed with existing standards. The semi-quantitative anlysis was conducted through a visual comparison of the intensity encountered in free cholesterol spots within samples under anlysis and the standard of different concentrations applied on the same board. Buffalo milk samples originated in the Mesendorf Farm, considered and certified as an ecologic farm.

  16. Anodic etching of GaN based film with a strong phase-separated InGaN/GaN layer: Mechanism and properties

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Qingxue [School of Physics, Shandong University, Jinan, 250100 (China); Liu, Rong [Department of Fundamental Theories, Shandong Institute of Physical Education and Sports, Jinan 250063 (China); Xiao, Hongdi, E-mail: hdxiao@sdu.edu.cn [School of Physics, Shandong University, Jinan, 250100 (China); Cao, Dezhong; Liu, Jianqiang; Ma, Jin [School of Physics, Shandong University, Jinan, 250100 (China)

    2016-11-30

    Highlights: • GaN film with a strong phase-separated InGaN/GaN layer was etched by electrochemical etching. • Vertically aligned nanopores in n-GaN films were buried underneath the InGaN/GaN structures. • The relaxation of compressive stress in the MQW structure was found by PL and Raman spectra. - Abstract: A strong phase-separated InGaN/GaN layer, which consists of multiple quantum wells (MQW) and superlattices (SL) layers and can produce a blue wavelength spectrum, has been grown on n-GaN thin film, and then fabricated into nanoporous structures by electrochemical etching method in oxalic acid. Scanning electron microscopy (SEM) technique reveals that the etching voltage of 8 V leads to a vertically aligned nanoporous structure, whereas the films etched at 15 V show branching pores within the n-GaN layer. Due to the low doping concentration of barriers (GaN layers) in the InGaN/GaN layer, we observed a record-low rate of etching (<100 nm/min) and nanopores which are mainly originated from the V-pits in the phase-separated layer. In addition, there exists a horizontal nanoporous structure at the interface between the phase-separated layer and the n-GaN layer, presumably resulting from the high transition of electrons between the barrier and the well (InGaN layer) at the interface. As compared to the as-grown MQW structure, the etched MQW structure exhibits a photoluminescence (PL) enhancement with a partial relaxation of compressive stress due to the increased light-extracting surface area and light-guiding effect. Such a compressive stress relaxation can be further confirmed by Raman spectra.

  17. Particle Image Velocimetry Measurements of a Two/Three-dimensional Separating/Reattaching Boundary Layer Downstream of an Axisymmetric Backward-facing Step

    Science.gov (United States)

    Hudy, Laura M.; Naguib, Ahmed M.; Humphreys, William M.; Bartram, Scott M.

    2005-01-01

    Planar Particle Image Velocimetry measurements were obtained in the separating/reattaching flow region downstream of an axisymmetric backward-facing step. Data were acquired for a two-dimensional (2D) separating boundary layer at five different Reynolds numbers based on step height (Re(sub h)), spanning 5900-33000, and for a three-dimensional (3D) separating boundary layer at Re(sub h) = 5980 and 8081. Reynolds number effects were investigated in the 2D cases using mean-velocity field, streamwise and wall-normal turbulent velocity, and Reynolds stress statistics. Results show that both the reattachment length (x(sub r)) and the secondary separation point are Reynolds number dependent. The reattachment length increased with rising Re(sub h) while the secondary recirculation region decreased in size. These and other Re(sub h) effects were interpreted in terms of changes in the separating boundary layer thickness and wall-shear stress. On the other hand, in the 3D case, it was found that the imposed cross-flow component was relatively weak in comparison to the streamwise component. As a result, the primary influences of three dimensionality only affected the near-separation region rather than the entire separation bubble.

  18. Water structure near single and multi-layer nanoscopic hydrophobic plates of varying separation and interaction potentials

    Indian Academy of Sciences (India)

    Malay Rana; Amalendu Chandra

    2008-06-01

    We have performed a series of molecular dynamics simulations of water containing two nanoscopic hydrophobic plates to investigate the modifications of the density and hydrogen bond distributions of water in the vicinity of the surfaces. Our primary goal is to look at the effects of plate thickness, solute–solvent interaction and also interplate separation on the solvent structure in the confined region between two graphite-like plates and also near the outer surfaces of the plates. The thickness of the plates is varied by considering single and triple-layer graphite plates and the interaction potential is varied by tuning the attractive strength of the 12–6 pair interaction potential between a carbon atom of the graphite plates and a water molecule. The calculations are done for four different values of the tuning parameter ranging from fully Lennard–Jones to pure repulsive pair interactions. It is found that both the solvation characteristics and hydrogen bond distributions can depend rather strongly on the strength of the attractive part of the solute–water interaction potential. The thickness of the plates, however, is found to have only minor effects on the density profiles and hydrogen bond network. This indicates that the long range electrostatic interactions between water molecules on the two opposite sides of the same plate do not make any significant contribution to the overall solvation structure of these hydrophobic plates. The solvation characteristics are primarily determined by the balance between the loss of energy due to hydrogen bond network disruption, cavity repulsion potential and offset of the same by attractive component of the solute–water interactions. Our studies with different system sizes show that the essential features of solvation properties, e.g. wetting and dewetting characteristics for different interplate separations and interaction potentials, are also present in relatively smaller systems consisting of a few hundred

  19. LARGE-EDDY SIMULATIONS OF A SEPARATION/REATTACHMENT BUBBLE IN A TURBULENT-BOUNDARY-LAYER SUBJECTED TO A PRESCRIBED UPPER-BOUNDARY, VERTICAL-VELOCITY PROFILE

    KAUST Repository

    Cheng, Wan

    2015-06-30

    We describe large-eddy simulations of turbulent boundary-layer flow over a flat plate at high Reynolds number in the presence of an unsteady, three-dimensional flow separation/reattachment bubble. The stretched-vortex subgrid-scale model is used in the main flow domain combined with a wall-model that is a two-dimensional extension of that developed by Chung & Pullin (2009). Flow separation and re-attachment of the incoming boundary layer is induced by prescribing wall-normal velocity distribution on the upper boundary of the flow domain that produces an adverse-favorable stream-wise pressure distribution at the wall. The LES predicts the distribution of mean shear stress along the wall including the interior of the separation bubble. Several properties of the separation/reattachment flow are discussed.

  20. Use of peak sharpening effects to improve the separation of chiral compounds with molecularly imprinted porous polymer layer open-tubular capillaries.

    Science.gov (United States)

    Kulsing, Chadin; Yang, Yuanzhong; Chowdhury, Jamil M; Boysen, Reinhard I; Hearn, Milton T W

    2017-02-17

    This investigation demonstrates the application of a new peak sharpening technique to improve the separation of difficult-to-resolve racemic mixtures in capillary electro-chromatography. Molecularly imprinted porous layer open tubular (MIP-PLOT) capillaries, prepared by a layer-on-layer polymerization approach with Z-l-Asp-OH as the template, were selected to validate the approach. SEM revealed that the polymer film thickness can be varied by changes in both the polymer composition and the layer-on-layer regime. Capillaries made with methacrylic acid as the functional monomer could not separate the Z-Asp-OH racemate, due to weak interactions between the MIP-PLOT material and the target analytes. In contrast, MIP-PLOT capillaries prepared with 4-vinylpyridine as the functional monomer resulted in increased ionic interactions with the target analytes. Separation of the enantiomers could be enhanced when a peak zone sharpening effect was exploited through the use of specific BGE compositions and by taking advantage of eigenpeak phenomena. In this manner, the position of a sharpening zone and the peak shape of the sample analytes could be fine-tuned, so that when the sharpening zone and the target analyte co-migrated the separation of the Z-l-Asp-OH enantiomer from its d-enantiomer in a racemic mixture could be achieved under overloading conditions.

  1. Grafting effect on the wetting and electrochemical performance of carbon cloth electrode and polypropylene separator in electric double layer capacitor

    Science.gov (United States)

    Stepniak, Izabela; Ciszewski, Aleksander

    Activated carbon (AC) fiber cloths and hydrophobic microporous polypropylene (PP) membrane, both modified by plasma-induced graft polymerization of acrylic acid (AAc) under UV irradiation, and filled with saturated lithium hydroxide solution were used as electrodes, a separator and electrolyte in electric double layer capacitors (EDLCs). The modification process changed the hydrophobic character of AC and PP materials to hydrophilic, made them wettable and serviceable as components of an electrochemical capacitor. The presence of poly(acrylic acid) on the AC and PP surface was confirmed by SEM and XPS methods. Electrochemical characteristics of EDLCs were investigated by cyclic voltammetry and galvanostatic charge-discharge cycle tests and also by impedance spectroscopy. At the 1000th cycle of potential cycling (1 A g -1) the specific capacitance of 110 F g -1 was obtained with a specific energy of 11 Wh kg -1 at power density of 1 kW kg -1. The above results provide valuable information which may be used when developing novel compositions of EDLCs.

  2. Bromate formation on the non-porous TiO2 photoanode in the photoelectrocatalytic system.

    Science.gov (United States)

    Selcuk, Huseyin; Sarikaya, Hasan Z; Bekbolet, Miray; Anderson, Marc A

    2006-02-01

    The increasing use of ozone in water disinfection processes has been the focus of considerable concern in regards to inorganic disinfection by product formation of bromate in waters containing bromide. Due to the public health risk caused by the presence of bromate as a suspected carcinogen, attention had been addressed to the conditions under which bromate is formed. In this study, photoanodic bromine generation and bromate (BrO(3)(-)) formation were investigated using a TiO(2) electrode in a photoelectrocatalytic (PEC) treatment process. The separation of anodic and cathodic reactions in the PEC system resulted in a pH decrease from 9.3 to 3.0 in the photoanode compartment and an increase to 11.0 in the cathode compartment. Under a photo-illumination intensity of 5.7 m W cm(-2) UV, a biasing potential of +1.0V vs SCE, a pH of 6.0 and at a NaBr concentration of 1.0 x 10(-2) M, active bromine formation increased over time with 2.4 x 10(-6) M min(-6) rate and reached a steady-state concentration of 1.44 x 10(-4) M in 60 min. Bromate formation was detected after a lag-period of 15 min and exhibited a continuous increasing trend with respect to irradiation time. No bromate formation was observed below pH 6.5 whereas an increasing bromate concentrations and pH up to pH=8.5 were noted.

  3. Separating semiconductor devices from substrate by etching graded composition release layer disposed between semiconductor devices and substrate including forming protuberances that reduce stiction

    Science.gov (United States)

    Tauke-Pedretti, Anna; Nielson, Gregory N; Cederberg, Jeffrey G; Cruz-Campa, Jose Luis

    2015-05-12

    A method includes etching a release layer that is coupled between a plurality of semiconductor devices and a substrate with an etch. The etching includes etching the release layer between the semiconductor devices and the substrate until the semiconductor devices are at least substantially released from the substrate. The etching also includes etching a protuberance in the release layer between each of the semiconductor devices and the substrate. The etch is stopped while the protuberances remain between each of the semiconductor devices and the substrate. The method also includes separating the semiconductor devices from the substrate. Other methods and apparatus are also disclosed.

  4. Anodic etching of GaN based film with a strong phase-separated InGaN/GaN layer: Mechanism and properties

    Science.gov (United States)

    Gao, Qingxue; Liu, Rong; Xiao, Hongdi; Cao, Dezhong; Liu, Jianqiang; Ma, Jin

    2016-11-01

    A strong phase-separated InGaN/GaN layer, which consists of multiple quantum wells (MQW) and superlattices (SL) layers and can produce a blue wavelength spectrum, has been grown on n-GaN thin film, and then fabricated into nanoporous structures by electrochemical etching method in oxalic acid. Scanning electron microscopy (SEM) technique reveals that the etching voltage of 8 V leads to a vertically aligned nanoporous structure, whereas the films etched at 15 V show branching pores within the n-GaN layer. Due to the low doping concentration of barriers (GaN layers) in the InGaN/GaN layer, we observed a record-low rate of etching (partial relaxation of compressive stress due to the increased light-extracting surface area and light-guiding effect. Such a compressive stress relaxation can be further confirmed by Raman spectra.

  5. Cobalt Ferrite Bearing Nitrogen-Doped Reduced Graphene Oxide Layers Spatially Separated with Microporous Carbon as Efficient Oxygen Reduction Electrocatalyst.

    Science.gov (United States)

    Kashyap, Varchaswal; Singh, Santosh K; Kurungot, Sreekumar

    2016-08-17

    The present work discloses how high-quality dispersion of fine particles of cobalt ferrite (CF) could be attained on nitrogen-doped reduced graphene oxide (CF/N-rGO) and how this material in association with a microporous carbon phase could deliver significantly enhanced activity toward electrochemical oxygen reduction reaction (ORR). Our study indicates that the microporous carbon phase plays a critical role in spatially separating the layers of CF/N-rGO and in creating a favorable atmosphere to ensure the seamless distribution of the reactants to the active sites located on CF/N-rGO. In terms of the ORR current density, the heat-treated hybrid catalyst at 150 °C (CF/N-rGO-150) is found to be clearly outperforming (7.4 ± 0.5 mA/cm(2)) the state-of-the-art 20 wt % Pt-supported carbon catalyst (PtC) (5.4 ± 0.5 mA/cm(2)). The mass activity and stability of CF-N-rGO-150 are distinctly superior to PtC even after 5000 electrochemical cycles. As a realistic system level exploration of the catalyst, testing of a primary zinc-air battery could be demonstrated using CF/N-rGO-150 as the cathode catalyst. The battery is giving a galvanostatic discharge time of 15 h at a discharge current density of 20 mA/cm(2) and a specific capacity of ∼630 mAh g(-1) in 6 M KOH by using a Zn foil as the anode. Distinctly, the battery performance of this system is found to be superior to that of PtC in less concentrated KOH solution as the electrolyte.

  6. Wall-pressure-array measurements beneath a two/three-dimensional separating/reattaching boundary layer over an axisymmetric backward-facing-step

    Science.gov (United States)

    Hudy, Laura; Naguib, Ahmed; Humphreys, J. R.; Bartram, Scott

    2003-11-01

    The surface-pressure signature of the structure within a separated flow region was investigated using a microphone array in the NASA Langley Subsonic Basic Research Tunnel. The experimental set-up consisted of an axisymmetric backward-facing step with a section upstream of the step that could rotate to create a 3D boundary layer at separation. In the flow region, 32 flush-mounted Emkay electret microphones detected the pressure signature and 56 static pressure taps characterized the mean pressure. The taps were also used to align the model in the tunnel. Data were acquired for 2D and 3D flow configurations for Reynolds numbers of 5250 and 10500, based on the step height. A spatio-temporal analysis of the data revealed the dominant flow modes in the separating shear layer and their convective characteristics for both the 2D and 3D cases. Furthermore, similarities and differences between the two situations were investigated.

  7. A supermolecular building layer approach for gas separation and storage applications: The eea and rtl MOF platforms for CO2 capture and hydrocarbon separation

    KAUST Repository

    Chen, Zhijie

    2015-01-01

    The supermolecular building layer (SBL) approach was employed to deliberately synthesize five novel metal-organic frameworks (1-5) with an exposed array of amide or amine functionalities within their pore system. The ability to decorate the pores with nitrogen donor moieties offers potential to evaluate/elucidate the structure-adsorption property relationship. Two MOF platforms, eea-MOF and rtl-MOF, based on pillaring of kgm-a or sql-a layers with heterofunctional 3-connected organic building blocks were targeted and constructed to purposely introduce and expose the desired amide or amine functionalities. Interestingly, gas adsorption properties of eea-MOF-4 (1) and eea-MOF-5 (2) showed that by simply altering the nitrogen donor position within the ligand, it is possible to relatively reduce the pore size of the related eea-MOF material and subsequently increase the associated CO2 uptake. The slightly confined pore space in 2, relative to 1, has enabled an enhancement of the pore local charge density and thus the observed relative increase in the CO2 and H2 isosteric heat of adsorption (Qst). In addition, light hydrocarbon adsorption studies revealed that 2 is more selective toward C2H6 and C3H8 over CH4 than 1, as exemplified for C2H6:CH4 (5:95) or C3H8:CH4 (5:95) binary gas mixtures. This journal is

  8. A supermolecular building layer approach for gas separation and storage applications: the eea and rtl MOF platforms for CO 2 capture and hydrocarbon separation

    KAUST Repository

    Chen, Zhijie

    2015-02-11

    The supermolecular building layer (SBL) approach was employed to deliberately synthesize five novel metal–organic frameworks (1–5) with an exposed array of amide or amine functionalities within their pore system. The ability to decorate the pores with nitrogen donor moieties offers potential to evaluate/elucidate the structure–adsorption property relationship. Two MOF platforms, eea-MOF and rtl-MOF, based on pillaring of kgm-a or sql-a layers with heterofunctional 3-connected organic building blocks were targeted and constructed to purposely introduce and expose the desired amide or amine functionalities. Interestingly, gas adsorption properties of eea-MOF-4 (1) and eea-MOF-5 (2) showed that by simply altering the nitrogen donor position within the ligand, it is possible to relatively reduce the pore size of the related eea-MOF material and subsequently increase the associated CO2 uptake. The slightly confined pore space in 2, relative to 1, has enabled an enhancement of the pore local charge density and thus the observed relative increase in the CO2 and H2 isosteric heat of adsorption (Qst). In addition, light hydrocarbon adsorption studies revealed that 2 is more selective toward C2H6 and C3H8 over CH4 than 1, as exemplified for C2H6 : CH4 (5 : 95) or C3H8 : CH4 (5 : 95) binary gas mixtures.

  9. Separation of FFA from Partially Hydrogenated Soybean Oil Hydrolysate by Means of Membrane Processing

    DEFF Research Database (Denmark)

    Jala, Ram Chandra Reddy; Guo, Zheng; Xu, Xuebing

    2011-01-01

    Different types of commercial porous and non-porous polymeric membranes have been investigated for their capabilities to separate free fatty acids (FFA) from hydrolysate of partially hydrogenated soybean oil. A regenerated cellulose (RC, PLAC) membrane exhibited the most prominent difference...

  10. Separation of H2O/CO2 Mixtures with Layered Adsorption Method for Greenhouse Gas Control

    Institute of Scientific and Technical Information of China (English)

    XU Dong; ZHANG Jun; LI Gang; XIAO Penny; ZHAI Yu-chun

    2012-01-01

    Multiple-layered vacuum swing adsorption technique was used and investigated in order to effectively keep the feed gas that flows into zeolite 13X zone being dry and keep the CAPEX down(not adding pre-treatment equipment).Activated carbon fiber(ACF) and alumina CDX were laid at the lower parts of the column as pre-layers to selectively adsorb moisture.Zeolite 13X was laid on the top of those two adsorbents as the main layer to capture CO2.Systematic cyclic experiments show that water vapor was successfully contained within the ACF and CDX layers at cyclic steady states.It was also found that ultimate vacuum pressure played a decisive factor for stabilizing the water front,and achieving good CO2 purity and recovery.The findings also reveal the pathway for large-scale CO2 capture process.

  11. Feasibility of correlating separation of ternary mixtures of neutral analytes via thin layer chromatography with supercritical fluid chromatography in support of green flash separations.

    Science.gov (United States)

    Ashraf-Khorassani, M; Yan, Q; Akin, A; Riley, F; Aurigemma, C; Taylor, L T

    2015-10-30

    Method development for normal phase flash liquid chromatography traditionally employs preliminary screening using thin layer chromatography (TLC) with conventional solvents on bare silica. Extension to green flash chromatography via correlation of TLC migration results, with conventional polar/nonpolar liquid mixtures, and packed column supercritical fluid chromatography (SFC) retention times, via gradient elution on bare silica with a suite of carbon dioxide mobile phase modifiers, is reported. Feasibility of TLC/SFC correlation is individually described for eight ternary mixtures for a total of 24 neutral analytes. The experimental criteria for TLC/SFC correlation was assumed to be as follows: SFC/UV/MS retention (tR) increases among each of the three resolved mixture components; while, TLC migration (Rf) decreases among the same resolved mixture components. Successful correlation of TLC to SFC was observed for most of the polar organic solvents tested, with the best results observed via SFC on bare silica with methanol as the CO2 modifier and TLC on bare silica with a methanol/dichloromethane mixture. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Stochastic rocket dynamics under random nozzle side loads: Ornstein-Uhlenbeck boundary layer separation and its coarse grained connection to side loading and rocket response

    CERN Document Server

    Keanini, R G; Tkacik, Peter T; Weggel, David C; Knight, P Douglas

    2011-01-01

    A long-standing, though ill-understood problem in rocket dynamics, rocket response to random, altitude-dependent nozzle side-loads, is investigated. Side loads arise during low altitude flight due to random, asymmetric, shock-induced separation of in-nozzle boundary layers. In this paper, stochastic evolution of the in-nozzle boundary layer separation line, an essential feature underlying side load generation, is connected to random, altitude-dependent rotational and translational rocket response via a set of simple analytical models. Separation line motion, extant on a fast boundary layer time scale, is modeled as an Ornstein-Uhlenbeck process. Pitch and yaw responses, taking place on a long, rocket dynamics time scale, are shown to likewise evolve as OU processes. Stochastic, altitude-dependent rocket translational motion follows from linear, asymptotic versions of the full nonlinear equations of motion; the model is valid in the practical limit where random pitch, yaw, and roll rates all remain small. Comp...

  13. Gold nanoparticles grafted modified silica gel as a new stationary phase for separation and determination of steroid hormones by thin layer chromatography

    Directory of Open Access Journals (Sweden)

    Mitra Amoli-Diva

    2015-06-01

    Full Text Available A new thin layer chromatographic layer using gold nanoparticles grafted 3-triethoxysilyl propylamine modified silica gel (Au NPs-APTS modified silica gel was developed as a stationary phase for separation and determination of two steroid hormones, namely progesterone and testosterone. Acetone–n-hexane 25:75 (v/v was used as the mobile phase, and the results were compared with those obtained using plain (i.e., unmodified silica gel plates. Some chromatographic parameters used for separation of the two steroids on an Au NPs-APTS modified silica gel plate as well as on a plain silica gel plate, including ΔRF, separation factor (α, and resolution (RS, were evaluated and compared. The reproducibility of RF values was also determined by analysis of the two steroids in 7 consecutive days on both plates. Validity of the method was investigated, and a wide linear range of 1–200 ng per spot, and low detection limits of 0.16 ng and 0.13 ng per spot, low quantification limits of 0.51 ng and 0.40 ng per spot, and good precision (expressed as percent relative standard deviation lower than 3.1% and 2.7% were obtained for progesterone and testosterone, respectively. As the results revealed, the proposed method is rapid and sensitive, and it is applicable to separation and determination of progesterone and testosterone in biological matrices such as urine samples.

  14. Layered Poly(ethylene-co-vinyl acetate)/Poly(ethylene-co-vinyl alcohol) Membranes with Enhanced Water Separation Selectivity and Performance.

    Science.gov (United States)

    Soto Puente, J A; Fatyeyeva, K; Chappey, C; Marais, S; Dargent, E

    2017-02-22

    A three-layered membrane based on poly(ethylene-co-vinyl acetate) (EVA) and hydrolyzed EVA-poly(ethylene-co-vinyl alcohol) (EVOH), was elaborated by the surface hydrolysis of a dense EVA membrane. Because of the chemical modifications, the three-layered EVOH/EVA/EVOH membrane was characterized by the particular microstructure (amorphous EVA and semicrystalline EVOH) and the tunable hydrophilic/hydrophobic balance. Also, these modifications led to the membrane with the selective barrier properties compared with the pure EVA and completely hydrolyzed EVOH membranes. The water barrier behavior was related to the strong hydrogen-bond interactions of water and vinyl alcohol groups, whereas the weak chemical interactions were revealed for gases (N2 and O2). Furthermore, the influence of the polymer rubbery or glassy state on the permeation kinetics was established. In the case of the three-layered membrane, the considerably high selectivity values were obtained for H2O/O2 (∼11 900) and H2O/N2 (∼48 000) at 25 °C. In addition to these highly selective properties, the three-layered structure does not present delamination features due to its elaboration procedure. Thus, these new layered membranes are very promising as selective materials for the water and gas separation and can be potentially used in food packaging or for the gas dehydration.

  15. Diffusion membrane and process for separating hydrogen from gas mixture

    Energy Technology Data Exchange (ETDEWEB)

    Behr, F.; Schulten, R.; Weirich, W.

    1985-01-29

    For separation of hydrogen and its isotopes by diffusion through a membrane virtually impermeable to other gases, a non-porous hydrogen-permeable metallic membrane is provided on the gas access side with a coating of an alloy of palladium with at least 45 atomic % Cu or at least 50 atomic percent Ag or at least 7 atomic % Y, the membrane itself containing Cu, Ag or Y respectively in a concentration at least equilibrated with the coating at operation temperature. Preferably the membrane consists of a metal of niobium and/or tantalum bases especially of an alloy containing from 10 to 30 % Ti, 3 to 10 % V, 0 to 25 % Nb and at least 30 % Ta, all by weight, and preferably it is of a composition of 20 to 25 % Ti, 5 to 7,5 % V, 0 to 25 Nb, and at least 50 % Ta, being saturated with copper and or silver, while a copper and/or silver palladium alloy coating is used. Such inherently oxidation sensitive membranes can be stabilized by provision of an internal intermediate layer in the form of a melt forming or containing an alkaline metal hydride and/or an alkaline earth metal hydride. A melt containing alkaline metal and/or alkaline earth metal which forms a hydride, brought into contact on the secondary side of a membrane in accordance with the invention, provides a hydrogen sink on the secondary side and inhibits internal hydride formation and secondary side oxidation of the membrane.

  16. Separation optimization of long porous-layer open-tubular columns for nano-LC-MS of limited proteomic samples.

    Science.gov (United States)

    Rogeberg, Magnus; Vehus, Tore; Grutle, Lene; Greibrokk, Tyge; Wilson, Steven Ray; Lundanes, Elsa

    2013-09-01

    The single-run resolving power of current 10 μm id porous-layer open-tubular (PLOT) columns has been optimized. The columns studied had a poly(styrene-co-divinylbenzene) porous layer (~0.75 μm thickness). In contrast to many previous studies that have employed complex plumbing or compromising set-ups, SPE-PLOT-LC-MS was assembled without the use of additional hardware/noncommercial parts, additional valves or sample splitting. A comprehensive study of various flow rates, gradient times, and column length combinations was undertaken. Maximum resolution for LC conditions or long silica monolith nanocolumns. Nearly 500 proteins (1958 peptides) could be identified in just one single injection of an extract corresponding to 1000 BxPC3 beta catenin (-/-) cells, and ~1200 and 2500 proteins in extracts of 10,000 and 100,000 cells, respectively, allowing detection of central members and regulators of the Wnt signaling pathway.

  17. A three-dimensional boundary-layer method for flow over delta wings with leading-edge separation

    Science.gov (United States)

    Woodson, S. H.; Dejarnette, F. R.

    1985-01-01

    A three-dimensional, laminar boundary-layer method is applied to the incompressible flow over a slender delta wing at incidence. The predictor-corrector finite-difference scheme of Matsuno is used to difference the governing equations. The method has the advantages that no iterations are required to advance the solution and the cross-flow derivatives are formed independent of the cross-field direction. The difference scheme is demonstrated to yield accurate numerical results when compared to the exact solution of the three-dimensional boundary-layer equations for parabolic flow over a moving flat plate. The method is applied to delta wings of various sweep angles at angles of attack up to 20 deg., with the inviscid solution determined using a higher-order, three-dimensional panel method.

  18. Separation and Detection of Ceramides by HPLC Followed by Evaporative Light-Scattering Detection and Thin Layer Chromatography

    Institute of Scientific and Technical Information of China (English)

    张琳; 周全; 傅学奇; 陈国强

    2002-01-01

    Ceramides are important signaling molecules involved in a variety of cellular processes, including cell growth, differentiation, and apoptosis. Currently, different methods are used for ceramide analysis, some of which are insensitive or cumbersome. This paper described methods utilizing thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC) followed by evaporative light scattering detection (ELSD) to detect ceramide directly in cell extracts without derivatization, which was proved to be efficient and reproducible. Five kinds of ceramides were used as standards. Both TLC and normal-phase HPLC/ELSD results indicate that yeast contains several kinds of ceramides.

  19. 油藏分注设计的层段组合参数优化%Research on Optimization Method of Layer Period Combination Parameter for Separated Layer Water Injection Design

    Institute of Scientific and Technical Information of China (English)

    吴义志

    2012-01-01

    With reservoir numerical simulation method, technology boundaries for layer period combination are given in the water-injection development. Permeability, viscosity, effective thickness, water injection time, number of segments, recovery have great effect on separated layer water injection. On this basis, quantitative optimization coefficient is put forward, and calculated with Grey correlation method. Results show that optimization coefficient and recovery of each layer have a good linear correlation which can be used as a basis of layer period combination. Optimization coefficient solves the nonuniqueness problem of the traditional layer period combination based on single factor and is advantageous to the reservoir layer evaluation and combination.%现场实施分层注水时,层段组合方式对油田的采出效果影响较大.运用油藏数值模拟的方法,系统研究了注水开发中层段组合的技术界限.研究表明隔层面积、渗透率级差、原油黏度级差、油层有效厚度等因素对于分层注水有较大的影响.在此基础上,提出了可量化的优化系数概念,并利用灰色关联方法进行计算.结果表明优化系数和采出程度之间有良好的线性相关性,可以作为标定油层品味的依据.解决了传统的以单因素为基准划分层系过程中出现的划分结果相互交叉、不唯一的问题,有利于对储层进行正确的评价与组合.

  20. Improving biogas separation and methane storage with multilayer graphene nanostructure via layer spacing optimization and lithium doping: a molecular simulation investigation.

    Science.gov (United States)

    Chen, Jie-Jie; Li, Wen-Wei; Li, Xue-Liang; Yu, Han-Qing

    2012-09-18

    Methane is a desirable alternative to conventional fossil fuels, and also a main component of biogas from anaerobic fermentation of organic wastes. However, its relatively lower purity and poor storage by existing adsorbent materials negatively affect its wide application. Thus, efficient, cost-effective, and safe adsorbent materials for methane purification and storage are highly desired. In this study, multilayer graphene nanostructures (MGNs) with optimized structure are investigated as a potential adsorbent for this purpose. The effects of layer distance and Li doping on MGN performance in terms of methane storage and acid gas (H(2)S and CO(2)) separation from biogas are examined by molecular simulations. The mechanisms for the interactions between gas molecules and substrates are elucidated by analyzing the binding energy, geometric structures, and charge distribution from the first-principles calculations. The results show that nonhydrocarbons in biogas can be effectively separated using Li-doped MGNs with the optimal layer distance of 0.68 nm, and then the pure methane gas can be stored in MGNs with capacity satisfying the DOE target. This work offers a molecular-level insight into the interactions between gas molecules and MGNs and might provide useful information for development of new materials for methane purification and storage.

  1. Porous TiO2 Nanotubes with Spatially Separated Platinum and CoOx Cocatalysts Produced by Atomic Layer Deposition for Photocatalytic Hydrogen Production.

    Science.gov (United States)

    Zhang, Jiankang; Yu, Zhuobin; Gao, Zhe; Ge, Huibin; Zhao, Shichao; Chen, Chaoqiu; Chen, Shuai; Tong, Xili; Wang, Meihua; Zheng, Zhanfeng; Qin, Yong

    2017-01-16

    Efficient separation of photogenerated electrons and holes, and associated surface reactions, is a crucial aspect of efficient semiconductor photocatalytic systems employed for photocatalytic hydrogen production. A new CoOx /TiO2 /Pt photocatalyst produced by template-assisted atomic layer deposition is reported for photocatalytic hydrogen production on Pt and CoOx dual cocatalysts. Pt nanoclusters acting as electron collectors and active sites for the reduction reaction are deposited on the inner surface of porous TiO2 nanotubes, while CoOx nanoclusters acting as hole collectors and active sites for oxidation reaction are deposited on the outer surface of porous TiO2 nanotubes. A CoOx /TiO2 /Pt photocatalyst, comprising ultra-low concentrations of noble Pt (0.046 wt %) and CoOx (0.019 wt %) deposited simultaneously with one atomic layer deposition cycle, achieves remarkably high photocatalytic efficiency (275.9 μmol h(-1) ), which is nearly five times as high as that of pristine TiO2 nanotubes (56.5 μmol h(-1) ). The highly dispersed Pt and CoOx nanoclusters, porous structure of TiO2 nanotubes with large specific surface area, and the synergetic effect of the spatially separated Pt and CoOx dual cocatalysts contribute to the excellent photocatalytic activity.

  2. Railroad Lines, Separate layers for active and inactive railroad lines for an eleven county region. Data is a subset from NCOneMap., Published in 2007, NC Dept of Commerce - DCA.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Railroad Lines dataset, was produced all or in part from Other information as of 2007. It is described as 'Separate layers for active and inactive railroad...

  3. Peak broadening in paper chromatography and related techniques VI. The efficiency of various kinds of chromatography paper and thin-layer cellulose powder for the separation of amino acids

    NARCIS (Netherlands)

    Ligny, C.L. de; Kok, E.C.M.

    1968-01-01

    The efficiency of several chromatography papers and thin-layer cellulose powders for the separation of amino acids is investigated, using the minimum elution time for a given resolution as the criterion.

  4. Peak broadening in paper chromatography and related techniques VI. The efficiency of various kinds of chromatography paper and thin-layer cellulose powder for the separation of amino acids

    NARCIS (Netherlands)

    Ligny, C.L. de; Kok, E.C.M.

    1968-01-01

    The efficiency of several chromatography papers and thin-layer cellulose powders for the separation of amino acids is investigated, using the minimum elution time for a given resolution as the criterion.

  5. Visualization of boundary layer separation and passive flow control on airfoils and bodies in wind-tunnel and in-flight experiments

    Science.gov (United States)

    Popelka, Lukas; Kuklova, Jana; Simurda, David; Souckova, Natalie; Matejka, Milan; Uruba, Vaclav

    2012-04-01

    Infrared camera, Particle Image Velocimetry, smoke-wire, tuft filaments and oil-flow visualization techniques were used for wind-tunnel and in-flight investigation of boundary layer separation, both stall and separation bubbles, related to the low-Reynolds numbers transition mechanism. Airfoils of Wortmann FX66 series and FX66 series wing-fuselage interaction, as well as modern airfoils and their wing-fuselage geometry were subject to study. The presence of previously identified structures in the CFD modelling, such as horse-shoe vortices, was confirmed in the flow. Wind-tunnels and in-flight measurements on sailplanes were carried out and effect of passive flow control devices - vortex generators - was surveyed; namely counter-rotating vortex generators and Zig-zag type turbulators were applied. Separation suppression and consequent drag coefficient reduction of test aircrafts was reached. PIV investigation was further extended by Time-Resolved techniques. An important study on structure of the turbulent flow in the lower atmosphere, creating an environment of the soaring flight, was presented.

  6. Visualization of boundary layer separation and passive flow control on airfoils and bodies in wind-tunnel and in-flight experiments

    Directory of Open Access Journals (Sweden)

    Matejka Milan

    2012-04-01

    Full Text Available Infrared camera, Particle Image Velocimetry, smoke-wire, tuft filaments and oil-flow visualization techniques were used for wind-tunnel and in-flight investigation of boundary layer separation, both stall and separation bubbles, related to the low-Reynolds numbers transition mechanism. Airfoils of Wortmann FX66 series and FX66 series wing-fuselage interaction, as well as modern airfoils and their wing-fuselage geometry were subject to study. The presence of previously identified structures in the CFD modelling, such as horse-shoe vortices, was confirmed in the flow. Wind-tunnels and in-flight measurements on sailplanes were carried out and effect of passive flow control devices - vortex generators - was surveyed; namely counter-rotating vortex generators and Zig-zag type turbulators were applied. Separation suppression and consequent drag coefficient reduction of test aircrafts was reached. PIV investigation was further extended by Time-Resolved techniques. An important study on structure of the turbulent flow in the lower atmosphere, creating an environment of the soaring flight, was presented.

  7. Polymeric molecular sieve membranes via in situ cross-linking of non-porous polymer membrane templates

    Science.gov (United States)

    Qiao, Zhen-An; Chai, Song-Hai; Nelson, Kimberly; Bi, Zhonghe; Chen, Jihua; Mahurin, Shannon M.; Zhu, Xiang; Dai, Sheng

    2014-04-01

    High-performance polymeric membranes for gas separation are attractive for molecular-level separations in industrial-scale chemical, energyand environmental processes. Molecular sieving materials are widely regarded as the next-generation membranes to simultaneously achieve high permeability and selectivity. However, most polymeric molecular sieve membranes are based on a few solution-processable polymers such as polymers of intrinsic microporosity. Here we report an in situ cross-linking strategy for the preparation of polymeric molecular sieve membranes with hierarchical and tailorable porosity. These membranes demonstrate exceptional performance as molecular sieves with high gas permeabilities and selectivities for smaller gas molecules, such as carbon dioxide and oxygen, over larger molecules such as nitrogen. Hence, these membranes have potential for large-scale gas separations of commercial and environmental relevance. Moreover, this strategy could provide a possible alternative to ‘classical’ methods for the preparation of porous membranes and, in some cases, the only viable synthetic route towards certain membranes.

  8. Separation of Scaptotrigona postica workers into defined task groups by the chemical profile on their epicuticle wax layer.

    Science.gov (United States)

    Poiani, Silvana B; Morgan, E David; Drijfhout, Falko P; da Cruz-Landim, Carminda

    2014-04-01

    During evolution, the cuticle surface of insects acquired functions in communication, such as inter- and intra-specific recognition, identification of gender, physiological state, and fertility. In eusocial bees, the information in the cuticular surface is important not only to discriminate nestmates from non-nestmates but also to identify an individual's class, life phase or task. A comparative study of the cuticular surface chemical profile of workers of Scaptotrigona postica in different phases of life, i.e., newly emerged workers (NE), brood comb area workers (CA), and forager workers (FO) was undertaken by gas chromatography linked to mass spectrometry. Multivariate statistical analysis was performed to verify how workers are grouped according to their chemical profile and to determine which compounds are responsible for separating them into groups. The cuticle surface of workers contains mainly hydrocarbons and a small amount of oxygenated compounds. Multivariate statistical analysis showed qualitative and quantitative variation in relation to the life phases/tasks performed, and all groups were distinct. The most abundant compound found in NE and CA was n-heptacosane, while in FO, it was (Z)-9-heptacosene. The compounds that differentiate NE from other groups are n-tricosane and n-hexacosane. A (Z)-X-octacosene and n-nonacosane are the chemicals that distinguish CA from NE and FO, while 11- and 13-methylpentacosane, (Z)-X-hexacosene, and (Z)-9-heptacosene characterize FO as distinct from NE and CA. The probable function of alkenes is nestmate recognition, mainly in FO. The results show that the cuticle surfaces of workers are characteristic of the phase of life/task performed by workers, allowing intra-colonial recognition.

  9. pH triggered superior selective adsorption and separation of both cationic and anionic dyes and photocatalytic activity on a fully exfoliated titanate layer-natural polymer based nanocomposite.

    Science.gov (United States)

    Sarkar, Amit Kumar; Saha, Arka; Panda, Asit Baran; Pal, Sagar

    2015-11-18

    A fully exfoliated titanate layer-natural polymer amylopectin based nanocomposite, with pH responsive superior selective adsorption, separation of both cationic (MB: 599 mg g(-1) at pH 9) and anionic (MO: 558 mg g(-1) at pH 3) dyes and photodegradation properties, has been realized through simultaneous in situ layered titanate formation, exfoliation and polymerization.

  10. Thermal desorption characteristics of CO, O2 and CO2 on non-porous water, crystalline water and silicate surfaces at sub-monolayer and multilayer coverages

    CERN Document Server

    Noble, J A; Dulieu, F; Fraser, H J

    2011-01-01

    The desorption characteristics of molecules on interstellar dust grains are important for modelling the behaviour of molecules in icy mantles and, critically, in describing the solid-gas interface. In this study, a series of laboratory experiments exploring the desorption of three small molecules from three astrophysically relevant surfaces are presented. The desorption of CO, O2 and CO2 at both sub-monolayer and multilayer coverages was investigated from non-porous water, crystalline water and silicate surfaces. Experimental data was modelled using the Polanyi-Wigner equation to produce a mathematical description of the desorption of each molecular species from each type of surface, uniquely describing both the monolayer and multilayer desorption in a single combined model. The implications of desorption behaviour over astrophysically relevant timescales are discussed.

  11. Combined urea-thin layer chromatography and silver nitrate-thin layer chromatography for micro separation and determination of hard-to-detect branched chain fatty acids in natural lipids.

    Science.gov (United States)

    Yan, Yuanyuan; Wang, Xingguo; Liu, Yijun; Xiang, Jingying; Wang, Xiaosan; Zhang, Huijun; Yao, Yunping; Liu, Ruijie; Zou, Xiaoqiang; Huang, Jianhua; Jin, Qingzhe

    2015-12-18

    A simple, fast and efficient procedure was developed for micro separation and enrichment of branched chain fatty acids (BCFA) from natural products using successive thin layer chromatography (TLC) technique coupling novel urea-TLC with AgNO3-TLC, which rely on the formation of urea adduction and AgNO3 bonding in methanol. These natural lipids contain a significant amount of straight chain fatty acids (FA). Fresh and fast urea-TLC and AgNO3-TLC plate making techniques were developed with more even coating and less coating material contamination before being utilized for separation. Goat milk fat was used as a model. Various experimental parameters that affect urea-TLC and AgNO3-TLC separation of BCFA were investigated and optimized, including coating of urea, concentration of original oil sample, mobile phase and sample application format. High efficiency of removal of straight chain FA was achieved with a low amount of sample in an easy and fast way. A total BCFA mix with much higher purity than previous studies was successfully achieved. The developed method has also been applied for the concentration and analysis of BCFA in cow milk fat and Anchovy oil. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Integral Characteristics of Stability of Coal-Water Slurries and Coal-Water Slurries Containing Petrochemicals By Evaluation of Separation Into Layers

    Directory of Open Access Journals (Sweden)

    Dmitrienko Margarita A.

    2016-01-01

    Full Text Available For wide use of coal and oil processing wastes in heat power industry we investigated the structural stability of coal-water slurries (CWS and coal-water slurries containing petrochemicals (CWSP. Three methods of evaluating slurry stability were considered. The method of evaluation of separation (into layers of the slurry was chosen to determine the stability of fuel compositions based on bituminous and brown coal, filter cakes of bituminous coals, waste motor, turbine, transformer, compressor oils, oil, oiled mixture and mazut. The experiments shown, that the addition of waste oils (with mass fraction of 10 % to investigated fuel compositions leads to increase of slurry segmental stability is almost by 2 times.

  13. Characterisation of surface ionisation and adsorption of phenol and 4-nitrophenol on non-porous carbon blacks

    OpenAIRE

    Carrott, Peter; Carrott, Manuela; Vale, Tania; Valente Nabais, Joao; Mourao, Paulo

    2008-01-01

    The adsorption of phenol and 4-nitrophenol from aqueous solutions by carbon blacks was studied. Particular attention was paid to the characterisation of the surface chemistry and ionisation of the carbon blacks by use of a simple carbon surface ionisation model, as well as the use of a normalised form of the Freundlich equation for the analysis of the adsorption isotherms. The results indicated that the solutes interact directly with the graphene layers and that the adsorpti...

  14. Reducing the Drag and Damage of a High-Speed Train by Analyzing and Optimizing its Boundary Layer Separation and Roll-up into Wake Vortices

    Science.gov (United States)

    Jiang, Chung-Hsiang; Marcus, Philip

    2012-11-01

    We present numerical calculations of the boundary layers and shed wake vortices behind several aerodynamic bodies and generic models of high-speed trains. Our calculations illustrate new visual diagnostics that we developed that clearly show where the separation of a boundary layer occurs and where, how, and with what angles (with respect to the stream-wise direction) the wake vortices form. The calculations also illustrate novel 3D morphing and mesh ``pushing and pulling'' techniques that allow us to change the shapes of aerodynamic bodies and models in a controlled and automated manner without spurious features appearing. Using these tools we have examined the patterns of the shed vortices behind generic bodies and trains and correlated them with the changes in the drag as well as with the effects of the shed vortices on the environment. In particular, we have applied these techniques to the end car of a next-generation, high-speed train in order to minimize the drag and to minimize the adverse effects of the shed vortices on the track ballast.

  15. Stochastic estimation of a two/three-dimensional separating/reattaching boundary layer flow field downstream of an axisymmetric backward-facing step

    Science.gov (United States)

    Hudy, Laura; Naguib, Ahmed; Humphreys, William; Bartram, Scott

    2004-11-01

    The spatio-temporal characteristics of a separating/reattaching flow region were investigated. The experimental set-up consisted of an axisymmetric backward-facing step with a section upstream of the step that could rotate to create a 3D boundary layer at separation. Beneath the flow region, 32 flush-mounted microphones detected the pressure signature that was acquired simultaneously with PIV measurements, which captured the velocity field above the surface. Data were obtained for different Reynolds numbers (Re), based on step height: five Re for the 2D flow case, ranging from 6100 to 33200, and two Re, 6100 and 8300, for the 3D case. Multi-point stochastic estimation was used to estimate the dominant flow structures above the wall from the wall-pressure signature and the results were compared with the instantaneous structures obtained from the PIV measurements. In addition, Re effects were explored in the 2D case. Supported by NSF grant CTS0116907 and partial support from ONR

  16. Aerogels of 1D Coordination Polymers: From a Non-Porous Metal-Organic Crystal Structure to a Highly Porous Material

    Directory of Open Access Journals (Sweden)

    Adrián Angulo-Ibáñez

    2016-01-01

    Full Text Available The processing of an originally non-porous 1D coordination polymer as monolithic gel, xerogel and aerogel is reported as an alternative method to obtain novel metal-organic porous materials, conceptually different to conventional crystalline porous coordination polymer (PCPs or metal-organic frameworks (MOFs. Although the work herein reported is focused upon a particular kind of coordination polymer ([M(μ-ox(4-apy2]n, M: Co(II, Ni(II, the results are of interest in the field of porous materials and of MOFs, as the employed synthetic approach implies that any coordination polymer could be processable as a mesoporous material. The polymerization conditions were fixed to obtain stiff gels at the synthesis stage. Gels were dried at ambient pressure and at supercritical conditions to render well shaped monolithic xerogels and aerogels, respectively. The monolithic shape of the synthesis product is another remarkable result, as it does not require a post-processing or the use of additives or binders. The aerogels of the 1D coordination polymers are featured by exhibiting high pore volumes and diameters ranging in the mesoporous/macroporous regions which endow to these materials the ability to deal with large-sized molecules. The aerogel monoliths present markedly low densities (0.082–0.311 g·cm−3, an aspect of interest for applications that persecute light materials.

  17. ASTM D395 Short-Term Compression Set of Solid (Non-Porous) Siloxanes: SE 1700, Sylgard 184, and "New" M9787

    Energy Technology Data Exchange (ETDEWEB)

    Small, Ward [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Pearson, Mark A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Jensen, Wayne A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-09-13

    Compression set of solid (non-porous) Dow Corning SE 1700, Sylgard 184, and “new” M9787 siloxane elastomers was measured according to ASTM D395 Method B. Specimens of SE 1700 were made using (1) the manufacturer’s suggested cure of 150°C for 30 min and (2) an extended cure of 60°C for 6 h and 150°C for 1 h followed by a post-cure under nitrogen purge at 125°C for 12 h. Four specimens of each material were aged at 25-27% compressive strain at 70°C under nitrogen purge for 70 h. Final thickness of each specimen was measured after a 30-min cooling/relaxation period, and compression set relative to deflection was calculated. The average compression set relative to deflection was 6.0% for SE 1700 made using the extended cure and post-cure, 11.3% for SE 1700 made using the manufacturer’s suggested cure, 12.1% for Sylgard 184, and 1.9% for M9787. The extended cure and post-cure reduced the amount of compression set in SE 1700.

  18. A facile approach to the synthesis of non-porous and microporous sub-micron spherical zirconia and alumina-zirconia solid solution.

    Science.gov (United States)

    Ghotbi, Mohammad Yeganeh; Nasiri, Vida; Rafiee, Mehdi

    2013-01-01

    Amorphous monodisperse sub-micron spherical zirconia and alumina/zirconia solid solution particles were prepared by hydrolysis of zirconium and aluminum salts in ethanol. The heat-treatment process of the amorphous materials in air atmosphere at 500°C for 2h leaded to the production of non-porous zirconia and alumina/zirconia solid solution in tetragonal phase. The alkaline etching process of the as-prepared alumina/zirconia solid solution resulted in the formation of mono-modal microporous material with specific surface area of 125.0 m(2) g(-1) in comparison with 2. 9m(2) g(-1) for the parent material. Thermal analysis of the solid solution revealed that the incorporation of aluminum ions in the zirconia structure has decreased the phase transformation temperature from amorphous to crystalline structure. Moreover, optical study confirmed the presence of oxygen vacancy defect by substitution of tetravalent cations, Zr(4+) by trivalent cations, Al(3+) in zirconia lattice.

  19. Mortadella sausage formulations with mechanically separated layer hen meat preblended with antioxidants Mortadela elaborada com cms de galinhas poedeiras pré-misturada com antioxidantes

    Directory of Open Access Journals (Sweden)

    Marco Antonio Trindade

    2006-06-01

    Full Text Available At the end of the laying cycle, layer hens can be used for production of mechanically separated meat (MSML for sausage manufacture. However, mechanically separated meats are susceptible to lipid and pigment oxidation during storage, problems that could be prevented by the use of antioxidants present in curing additives traditionally used in meat processing. The objective of this work was to evaluate the quality and stability of Mortadella produced with MSML added of sodium erythorbate (1000 ppm and sodium nitrite (150 ppm through preblending or during chopper processing (control treatment, after long term frozen storage of raw meat ingredient. The products were stored for 40 days at 7ºC and evaluated in regard to the oxidative stability of lipids (TBARS values, objective color, and microbiological and sensory attributes. Preblending MSML lessened rancidity of the final product in comparison to the control (0.2 and 2.2 mg malonaldehyde per kg, respectively, and elicited better color (a* = 7.5 and 10.5, respectively. Total counts of psychrotrophic microorganisms were similar for both treatments (2 log CFU g-1. Previous blending of nitrite (150 ppm and erythorbate (1000 ppm in mechanically separated meat soon after the extraction is recommended when the raw material will eventually go through prolonged frozen storage before its use in Mortadella sausage processing.Uma das formas de utilização das galinhas poedeiras ao final do ciclo de postura é a obtenção de carne mecanicamente separada (MSML para a elaboração de embutidos. Entretanto, carnes mecanicamente separadas apresentam alta susceptibilidade à oxidação lipídica e dos pigmentos. O uso de antioxidantes tradicionalmente utilizados na cura de carne para incorporação prévia à matéria prima poderia evitar estes problemas. Assim, o objetivo deste trabalho foi avaliar a qualidade e a estabilidade de mortadelas elaboradas com MSML com adição de eritorbato (1000 ppm e nitrito (150

  20. Different effects of surface heterogeneous atoms of porous and non-porous carbonaceous materials on adsorption of 1,1,2,2-tetrachloroethane in aqueous environment.

    Science.gov (United States)

    Chen, Weifeng; Ni, Jinzhi

    2017-05-01

    The surface heterogeneous atoms of carbonaceous materials (CMs) play an important role in adsorption of organic pollutants. However, little is known about the surface heterogeneous atoms of CMs might generate different effect on adsorption of hydrophobic organic compounds by porous carbonaceous materials - activated carbons (ACs) and non-porous carbonaceous materials (NPCMs). In this study, we observed that the surface oxygen and nitrogen atoms could decrease the adsorption affinity of both ACs and NPCMs for 1,1,2,2-tetrachloroethane (TeCA), but the degree of decreasing effects were very different. The increasing content of surface oxygen and nitrogen ([O + N]) caused a sharper decrease in adsorption affinity of ACs (slope of lg (kd/SA) vs [O + N]: -0.098∼-0.16) than that of NPCMs (slope of lg (kd/SA) vs [O + N]: -0.025∼-0.059) for TeCA. It was due to the water cluster formed by the surface hydrophilic atoms that could block the micropores and generate massive invalid adsorption sites in the micropores of ACs, while the water cluster only occupied the surface adsorption sites of NPCMs. Furthermore, with the increasing concentration of dissolved TeCA, the effect of surface area on adsorption affinity of NPCMs for TeCA kept constant while the effect of [O + N] decreased due to the competitive adsorption between water molecule and TeCA on the surface of NPCMs, meanwhile, both the effects of micropore volume and [O + N] on adsorption affinity of ACs for TeCA were decreased due to the mechanism of micropore volume filling. These findings are valuable for providing a deep insight into the adsorption mechanisms of CMs for TeCA.

  1. Integration of biohydrogen fermentation and gas separation processes to recover and enrich hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Belafi-Bako, K.; Bucsu, D. [Research Institute of Chemical and Process Engineering, University of Veszprem, Egyetem u. 2., 8200 Veszprem (Hungary); Pientka, Z. [Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovsky sq. 2., Prague (Czech Republic); Balint, B.; Herbel, Z.; Kovacs, K.L. [Department of Biotechnology and Institute of Biophysics, Biological Research Center, Hungarian Academy of Sciences, University of Szeged, Temesvari krt. 62., 6726 Szeged (Hungary); Wessling, M. [Membrane Technology Group, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands)

    2006-09-15

    An integrated system for biohydrogen production and separation was designed, constructed and operated where biohydrogen was fermented by Thermococcus litoralis, a heterotrophic archaebacterium, and a two-step gas separation process was coupled to recover and concentrate hydrogen. A special liquid seal system was built to deliver, compress and collect the laboratory scale, low volume gas mixtures consisting of hydrogen, nitrogen and carbon dioxide. As a result, gas mixture with 73% high hydrogen content was produced by a combination of a porous and a non-porous gas separation membrane. (author)

  2. Application of Wireless Intelligent Separate Layer Injection Technology in Toothbrush-shape Reservoir%无线智能分注技术在牙刷状油藏上的应用∗

    Institute of Scientific and Technical Information of China (English)

    雷创; 马永忠; 安淑凯; 王桂林; 郭栋; 李小永

    2016-01-01

    为提高牙刷状油藏的分注效果,应用了无线智能分注技术。该技术通过采集存储井下分层流量和压力等数据,测试资料准确性高。根据需要设定时间自动验封测调,下井前配水器设定打开时间,坐封安装井口后即可注水,无需单独下电缆开水嘴,同时应用无线通信功能,提高了测试成功率和分注合格率。在4口注水井上进行了现场试验,措施后4口井均正常投注,测试成功率100%,分注合格率100%,对应9口油井中7口油井见效,当年累计增油2658 t。无线智能分注技术对于同类型牙刷状油藏的分层注水开发具有很好的增产效果。%To improve the water injection performance of the toothbrush⁃shaped reservoir, wireless intelligent separate layer water injection technology has been taken to acquire and store each layer’ s flow and pressure data, thus results in high⁃accuracy test data. Seal test, testing and adjustment could be automatically done according to the pre⁃set time. Water regulator opening time is set before run⁃in⁃hole. Water injection could begin once the packer is set and the wellhead is installed, eliminating the need of run⁃in cable to open the water nozzle. The application of wireless communication improves the success rate of testing and separate layer water injection. In field application, four water injection wells were all normally put into injection with the testing success rate of 100% and the separate layer water injection pass rate of 100%. 7 wells of the 9 corresponding wells have been observed enhanced oil recov⁃ery with cumulative oil of 2 658 t. Wireless intelligent separate layer water injection technology has a good effect for the separate layer waterflooding development of similar type of toothbrush⁃shape reservoir.

  3. RACORO Continental Boundary Layer Cloud Investigations: 3. Separation of Parameterization Biases in Single-Column Model CAM5 Simulations of Shallow Cumulus

    Science.gov (United States)

    Lin, Wuyin; Liu, Yangang; Vogelmann, Andrew M.; Fridlind, Ann; Endo, Satoshi; Song, Hua; Feng, Sha; Toto, Tami; Li, Zhijin; Zhang, Minghua

    2015-01-01

    Climatically important low-level clouds are commonly misrepresented in climate models. The FAst-physics System TEstbed and Research (FASTER) Project has constructed case studies from the Atmospheric Radiation Measurement Climate Research Facility's Southern Great Plain site during the RACORO aircraft campaign to facilitate research on model representation of boundary-layer clouds. This paper focuses on using the single-column Community Atmosphere Model version 5 (SCAM5) simulations of a multi-day continental shallow cumulus case to identify specific parameterization causes of low-cloud biases. Consistent model biases among the simulations driven by a set of alternative forcings suggest that uncertainty in the forcing plays only a relatively minor role. In-depth analysis reveals that the model's shallow cumulus convection scheme tends to significantly under-produce clouds during the times when shallow cumuli exist in the observations, while the deep convective and stratiform cloud schemes significantly over-produce low-level clouds throughout the day. The links between model biases and the underlying assumptions of the shallow cumulus scheme are further diagnosed with the aid of large-eddy simulations and aircraft measurements, and by suppressing the triggering of the deep convection scheme. It is found that the weak boundary layer turbulence simulated is directly responsible for the weak cumulus activity and the simulated boundary layer stratiform clouds. Increased vertical and temporal resolutions are shown to lead to stronger boundary layer turbulence and reduction of low-cloud biases.

  4. Spatially separated atomic layer deposition of Al2O3, a new option for high-throughput Si solar cell passivation

    NARCIS (Netherlands)

    Vermang, B.; Werner, F.; Stals, W; Lorenz, A.; Rothschild, A.; Racz, A.; John, J.; Poortmans, J.; Mertens, R.; Gortzen, R.M.W.; Poodt, P.W.G.; Tiba, V.; Roozeboom, F.; Schmidt, J.

    2011-01-01

    A next generation material for surface passivation of crystalline Si is Al2O3. It has been shown that both thermal and plasma-assisted (PA) atomic layer deposition (ALD) A l2O3 provide an adequate level of surface passivation for both p- and n-type Si substrates. However, conventional time-resolved

  5. Using an improved 1D boundary layer model with CFD for flux prediction in gas-sparged tubular membrane ultrafiltration.

    Science.gov (United States)

    Smith, R; Taha, T; Cui, Z F

    2005-01-01

    Tubular membrane ultrafiltration and microfiltration are important industrial separation and concentration processes. Process optimisation requires reduction of membrane build-up. Gas slug introduction has been shown to be a useful approach for flux enhancement. However, process quantification is required for design and optimisation. In this work we employ a non-porous wall CFD model to quantify hydrodynamics in the two-phase slug flow process. Mass transfer is subsequently quantified from wall shear stress, which was determined from the CFD. The mass transfer model is an improved one-dimensional boundary layer model, which empirically incorporates effects of wall suction and analytically includes edge effects for circular conduits. Predicted shear stress profiles are in agreement with experimental results and flux estimates prove more reliable than that from previous models. Previous models ignored suction effects and employed less rigorous fluid property inclusion, which ultimately led to under-predictive flux estimates. The presented model offers reliable process design and optimisation criteria for gas-sparged tubular membrane ultrafiltration.

  6. Amorphous-crystalline dual-layer structures resulting from metastable liquid phase separation in (Fe50Co25B15Si10)8oCu20 melt-spun ribbons

    Institute of Scientific and Technical Information of China (English)

    Cao Chong-De; Gong Su-Lian; Guo Jin-Bo; Song Rui-Bo; Sun Zhan-Bo; Yang Sen; Wang Wei-Min

    2012-01-01

    (Fe50Co25B15Si10)80Cu20 ribbons are prepared by using the single-roller melt-spinning method.A dual-layer structure consisting of a (Fe,Co)-rich amorphous phase and a Cu-rich crystalline phase forms due to metastable liquid phase separation before solidification.The magnetic hysteresis loops of the as-quenched and annealed samples are measured at room temperature.It is indicated that the coercivity of the ribbon is almost zero in the as-quenched state.The crystallization leads to the increase of coercivity and decrease of saturation magnetization.

  7. Seeing Beyond the Painting Surface with Terahertz Time-Domain Imaging (THz-TDI): a signal separation method for extracting images of buried individual layers in paintings

    DEFF Research Database (Denmark)

    Filtenborg, Troels Folke; Skou-Hansen, Jakob; Koch Dandolo, Corinna Ludovica

    2015-01-01

    In this study, the 18C easel painting The Dying Messalina and her Mother, by Nicolai Abildgaard (Statens Museum for Kunst collection, Copenhagen, Denmark), has been investigated by Terahertz Time-Domain Imaging (THz-TDI) in reflection set-up. Despite the validity of traditional deconvolution...... and denoising methods used to resolve temporal features of THz reflected signals, they result impractical if applied to large images analysis. Therefore, we presented a simple, fast and effective method to separate single THz pulses of interest from the entire signal recorded at each spatial coordinate...

  8. Direct coupling of thin-layer chromatography-bioautography with electrostatic field induced spray ionization-mass spectrometry for separation and identification of lipase inhibitors in lotus leaves.

    Science.gov (United States)

    Zhang, Lei; Shi, Jiyao; Tang, Jihe; Cheng, Zhihong; Lu, Xiaohui; Kong, Yao; Wu, Tao

    2017-05-15

    In situ profiling compounds in complex matrices is important technology to develop in analytic chemistry. The aim of this study is to develop a direct coupling method of thin layer chromatography (TLC) to mass spectrometry (MS) via electrostatic field induced spray ionization (EFISI). We proposed a surface treatment method of normal-phase thin layer chromatography (TLC) plates with dimethyl silicone oil coating which successfully allowed TLC to couple to MS via EFISI. Different parameters affecting the ionization efficiency were investigated and optimized, including silicone oil concentrations, air-drying times, applied voltages, and TLC plate types. This optimized TLC-EFISI-MS method was successfully applied to examine lipase inhibitory components present in lotus leaves. Six active alkaloids including three aporphines and three benzylisoquinolines were profiled with their MS(n) (n = 4) data, or with a comparison with reference substances. This is the first report on the coupling EFISI-MS to TLC or TLC bioautography for in situ identification of active natural products. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Separation of flow

    CERN Document Server

    Chang, Paul K

    2014-01-01

    Interdisciplinary and Advanced Topics in Science and Engineering, Volume 3: Separation of Flow presents the problem of the separation of fluid flow. This book provides information covering the fields of basic physical processes, analyses, and experiments concerning flow separation.Organized into 12 chapters, this volume begins with an overview of the flow separation on the body surface as discusses in various classical examples. This text then examines the analytical and experimental results of the laminar boundary layer of steady, two-dimensional flows in the subsonic speed range. Other chapt

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

    Science.gov (United States)

    Utaka, Yoshio; Koresawa, Ryo

    2017-09-01

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

  11. Resolution and isolation of enantiomers of (±)-isoxsuprine using thin silica gel layers impregnated with L-glutamic acid, comparison of separation of its diastereomers prepared with chiral derivatizing reagents having L-amino acids as chiral auxiliaries.

    Science.gov (United States)

    Bhushan, Ravi; Nagar, Hariom

    2015-03-01

    Thin silica gel layers impregnated with optically pure l-glutamic acid were used for direct resolution of enantiomers of (±)-isoxsuprine in their native form. Three chiral derivatizing reagents, based on DFDNB moiety, were synthesized having l-alanine, l-valine and S-benzyl-l-cysteine as chiral auxiliaries. These were used to prepare diastereomers under microwave irradiation and conventional heating. The diastereomers were separated by reversed-phase high-performance liquid chromatography on a C18 column with detection at 340 nm using gradient elution with mobile phase containing aqueous trifluoroacetic acid and acetonitrile in different compositions and by thin-layer chromatography (TLC) on reversed phase (RP) C18 plates. Diastereomers prepared with enantiomerically pure (+)-isoxsuprine were used as standards for the determination of the elution order of diastereomers of (±)-isoxsuprine. The elution order in the experimental study of RP-TLC and RP-HPLC supported the developed optimized structures of diastereomers based on density functional theory. The limit of detection was 0.1-0.09 µg/mL in TLC while it was in the range of 22-23 pg/mL in HPLC and 11-13 ng/mL in RP-TLC for each enantiomer. The conditions of derivatization and chromatographic separation were optimized. The method was validated for accuracy, precision, limit of detection and limit of quantification.

  12. Mechanically separated meat of broiler breeder and white layer spent hens Carne mecanicamente separada de galinhas poedeiras e matrizes pesadas de descarte

    Directory of Open Access Journals (Sweden)

    Marco Antonio Trindade

    2004-04-01

    Full Text Available There are aproximately 90 millions of hens housed in Brazil, that concluding their production cycle, become available for slaughter. The poultry industry has economical interest in the use of spent hen meat through adequate processes. This review evaluates the quality of mechanically separated spent hen meat by chemical and functional characteristics, such as proximate composition, colagen, cholesterol, bones, calcium and iron contents, fatty acid profile, pH and emulsifying capacity, and as raw material for sausage production. The mechanical separation of meat migth be a good alternative use for spent hen carcasses.O Brasil dispõe de aproximadamente 90 milhões de galinhas poedeiras e matrizes pesadas de corte comerciais alojadas, que tornam-se disponíveis para abate ao final do ciclo de postura. Uma melhor utilização da carne de galinhas de descarte, através de processamentos adequados, interessa economicamente para a indústria avícola. Esta revisão avaliou a qualidade da carne mecanicamente separada de galinhas, através de características químicas, nutricionais e de funcionalidade tais como composição centesimal, teores de colágeno, colesterol, ossos, cálcio e ferro, perfil de ácidos graxos, valor de pH ecapacidade de emulsificação, como matéria-prima para a fabricação de embutidos. A separação mecânica da carne pode representar uma boa alternativa para utilização das carcaças destas aves.

  13. Separation membrane development

    Energy Technology Data Exchange (ETDEWEB)

    Lee, M.W. [Savannah River Technology Center, Aiken, SC (United States)

    1998-08-01

    A ceramic membrane has been developed to separate hydrogen from other gases. The method used is a sol-gel process. A thin layer of dense ceramic material is coated on a coarse ceramic filter substrate. The pore size distribution in the thin layer is controlled by a densification of the coating materials by heat treatment. The membrane has been tested by permeation measurement of the hydrogen and other gases. Selectivity of the membrane has been achieved to separate hydrogen from carbon monoxide. The permeation rate of hydrogen through the ceramic membrane was about 20 times larger than Pd-Ag membrane.

  14. Rigid, non-porous and tunable hybrid p-aminobenzoate/TiO2 materials: Toward a fine structural determination of the immobilized RhCl(Ph3)3 complex

    KAUST Repository

    Espinas, Jeff

    2015-05-01

    By exchange of ligands, Wilkinson complex RhCl(PPh3)3 are immobilized on p-aminobenzoate/TiO2 with different organic loading (6, 11 and 16%). This new hybrid material exhibit a linear correlation between the ligand content of the starting TiO2 and the rhodium loading, showing the accessibility of all surfaces amines fonctions on the non-porous parent materials. 1H, 13C, and 1D, 2D INAQUEDATE refocused and J-resolved 31P solid-state NMR confirm the well-defined structure [(≡TiO)2(n{right tail}2-O2C-C6H4-NH2)RhCl-cis-(PPh3)2]. New immobilized catalysts show interesting activity in cyclohexene hydroformylation.

  15. 小麦麸皮结构层干法分离的初步研究%Preliminary Study on the Dry-Process Separation of Different Wheat Bran Structral Layers

    Institute of Scientific and Technical Information of China (English)

    陈中伟; 王莉; 杨春霞; 吴保承; 田燕宁; 陈正行

    2013-01-01

    研究了干法分离麦麸结构层.首先对小麦麸皮进行微粉碎,通过粒径分析出麦麸粉体的粒径分散性最好的粉碎时间,利用旋振筛对此时的麦麸进行筛分,得到粒径不同的4种麦麸粉体,然后对各个麦麸粉体进行荧光定性和生化标示物定量研究.结果表明,筛分后,外皮层和中间层集中在200目筛上物的麦麸中,约占78.9%,麦麸糊粉层的细胞壁主要集中在200目筛下物和325目筛上物中,比例达41.7%,而小颗粒的麦麸糊粉层细胞内容物则集中在325目筛下物.研究初步表明,通过微粉碎和筛分的方法可以对不同麦麸结构层进行富集,为麦麸的深加工提供了一种简单的干法分离途径.%In this paper, we studied the dry - process separation of different wheat bran structural layers. After crushing wheat bran into powders, we analyzed the crushing time for the best particle size dispersibility of the powders. After sieving the wheat bran with vibrating sieves we obtained four kinds of wheat bran powders of different particle sizes and then conducted fluorescent qualitative study and quantitative research of biochemical marker composition for various wheat bran powders. As the results showed, after the sieving, the exodermis and intermediate layers were concentrated in the wheat bran powders on the sieve of 200 mesh with an occupied proportion of 78. 9% , aleu-rone layer cell wall between the sieve of. 200 mesh and 325 mesh with the proportion of up to 41. 7% , and short grained aleurone layer cellular contents under the sieve of 325 mesh. This study premilinarily indicated that the different layers of wheat bran could be enriched through the methods of crushing and sieving, which provided a simple dry - process sepatation method for wheat bran deep processing.

  16. Additional heat treatment of non-porous coatings obtained on medium carbon steel substrates by electron beam cladding of a Ti-Mo-C powder composition

    Science.gov (United States)

    Mul, D. O.; Drobyaz, E. A.; Zimoglyadova, T. A.; Bataev, V. A.; Lazurenko, D. V.; Shevtsova, L. I.

    2016-04-01

    The structure and microhardness of surface layers, obtained by non-vacuum electron beam cladding of Ti-Mo-C powder mixture on a steel substrate after different types of heat treatment, were investigated. After cladding samples were heat treated in a furnace at 200...500 °C, as well as quenched at 860 ° C and then underwent high-temperature tempering. Heat treatment of cladded coatings induced tempering of martensite and precipitation of cementite particles (Fe3C). Transmission electron microscopy of the samples after heating and holding at 300 ° C revealed precipitation of nanosized cubical TiC particles. The formation of hard nanosized particles led to the surface layer microhardness growth. The highest level of microhardness (which was 1.2...1.5-fold higher in comparison with coating microhardness after heat treatment) was achieved after heating of the claded material at 300 °C and 400 °C Additional quenching of samples at 860 °C did not increase the microhardness level.

  17. 低雷诺数涡轮叶片边界层转捩及分离特性测量%Measurement of the Transition and Separation for Turbine Blade Boundary Layer with Low-Reynolds Number

    Institute of Scientific and Technical Information of China (English)

    乔渭阳; 赵磊; 罗华玲; 伊进宝; 张军胜

    2012-01-01

    低雷诺数工作条件下涡轮流场特征及其控制设计,是航空发动机低压涡轮部件设计的难点和重点。针对低雷诺数涡轮叶栅流场开展了实验研究工作,利用油流显示、表面静压、边界层压力探针等测量手段研究了涡轮叶片边界层的分离和转捩。结果表明雷诺数降低导致了流动损失的增大,且存在一个临界雷诺数。当雷诺数小于临界雷诺数时,发生在吸力面的流动分离是开式的层流分离泡,不会再附与叶片;当雷诺数大于临界雷诺数时,分离流会在尾缘前重新附着于叶片吸力面,形成闭式分离泡。随着雷诺数的减小,出口尾迹变宽,出口流动损失、出口速度亏损和出口气流角偏离增大,尾迹中心向吸力面方向移动。%The flow field characteristics and its control under Low-Reynolds numbers work condition are essential for the Aero-Engine Low Pressure Turbine design. An experimental investigation was conducted on the turbine cascade flow field with the low - Reynolds numbers. The separation and transition of the boundary layer on the suction side of turbine blade were in- vestigated with the special oil flow display, surface static pressure holes, and boundary layer pressure probe. The detailed measurement results for the turbine cascade outflow field and blade surface boundary layer were presented. The results show that the flow losses increase with the decrease of Reynolds number, and a critical Reynolds number is in existence. When the Reynolds number is less than this critical value, the flow separation occurs on the suction surface with an open laminar separa- tion bubble, and flow can not reattach. When the Reynolds number is larger than the critical value, the separated flow reat- taches before the blade trailing and a closed separation bubble is formed. As the Reynolds number decreases, the exit wake is broadened, while exit flow loss and exit velocity deficit, as well

  18. Separation Logic

    DEFF Research Database (Denmark)

    Reynolds, John C.

    2002-01-01

    expressions) for accessing and modifying shared structures, and for explicit allocation and deallocation of storage. Assertions are extended by introducing a "separating conjunction" that asserts that its sub-formulas hold for disjoint parts of the heap, and a closely related "separating implication". Coupled......, dynamically allocated arrays, and recursive procedures. We will also discuss promising future directions....

  19. Measurements of a Separating Turbulent Boundary Layer.

    Science.gov (United States)

    1980-04-01

    operational. Diana Cantu, Judy Whirley, and Yolanda Contreras put the figures, tables, and manuscript into the present form. I I ~I ’I m_ I TABLE OF...high overheat ratio was used since Wood (1975) I showed that the range of flat frequency response is improved with a higher m overheat ratio. Standard...67, pp. 125-143. I Wood , N. B. 1975 "A Method for Determination and Control of the Frequency Response of the Constant-Temperature Hot-Wire Anemometer

  20. Synthesis and characterization of ceramic-supported and metal-supported membrane layers for the separation of CO{sub 2} in fossil-fuel power plants; Herstellung und Charakterisierung von keramik- und metallgestuetzten Membranschichten fuer die CO{sub 2}-Abtrennung in fossilen Kraftwerken

    Energy Technology Data Exchange (ETDEWEB)

    Hauler, Felix

    2010-07-01

    The separation of CO{sub 2} in fossil fuel power plants has become a very important issue due to the contribution of this greenhouse gas to global warming. Thin microporous membranes are promising candidates for separating CO{sub 2} from gas flow before being exhausted into the atmosphere. The membrane demands are good permeation and separation properties and high stability under operation conditions. Novel sol-gel derived materials composed of TiO{sub 2}/ZrO{sub 2} and stabilized SiO{sub 2} seem to be promising due to their good chemical stability and microporous character, especially for the separation of H{sub 2} and CO{sub 2}. Metallic substrates should be preferred as membrane support because they exhibit practical advantages combining good mechanical stability and the benefit of facilitated joining. The present thesis deals with the development of sol-gel derived microporous membrane layers on ceramic and metallic supports for the separation of CO{sub 2}. In this context, the optimized preparation of high-quality membranes with TiO{sub 2}/ZrO{sub 2} and Ni, Co, Zr, Ti doped SiO{sub 2} top layers is presented. These multilayered membranes consist of a graded pore structure to provide a smooth transition of the pore size from the support to the functional layer. Due to the good surface properties, the ceramic substrates only need one interlayer, whereas the rough metallic substrates exhibiting larger pores require a total of three interlayers to obtain an enhanced surface quality. On both types of supports, crack-free functional layers with a thickness below 100 nm were deposited by dip-coating. The unsupported and supported sol-gel materials used for the top layers were investigated in terms of structural properties by thermal analysis, sorption measurements, X-ray diffraction and electron microscopy. Gas permeation tests with He, H{sub 2}, CO{sub 2} und N{sub 2} were carried out to determine the membrane performance with regard to permeation rates and

  1. Hydrogen separation process

    Science.gov (United States)

    Mundschau, Michael [Longmont, CO; Xie, Xiaobing [Foster City, CA; Evenson, IV, Carl; Grimmer, Paul [Longmont, CO; Wright, Harold [Longmont, CO

    2011-05-24

    A method for separating a hydrogen-rich product stream from a feed stream comprising hydrogen and at least one carbon-containing gas, comprising feeding the feed stream, at an inlet pressure greater than atmospheric pressure and a temperature greater than 200.degree. C., to a hydrogen separation membrane system comprising a membrane that is selectively permeable to hydrogen, and producing a hydrogen-rich permeate product stream on the permeate side of the membrane and a carbon dioxide-rich product raffinate stream on the raffinate side of the membrane. A method for separating a hydrogen-rich product stream from a feed stream comprising hydrogen and at least one carbon-containing gas, comprising feeding the feed stream, at an inlet pressure greater than atmospheric pressure and a temperature greater than 200.degree. C., to an integrated water gas shift/hydrogen separation membrane system wherein the hydrogen separation membrane system comprises a membrane that is selectively permeable to hydrogen, and producing a hydrogen-rich permeate product stream on the permeate side of the membrane and a carbon dioxide-rich product raffinate stream on the raffinate side of the membrane. A method for pretreating a membrane, comprising: heating the membrane to a desired operating temperature and desired feed pressure in a flow of inert gas for a sufficient time to cause the membrane to mechanically deform; decreasing the feed pressure to approximately ambient pressure; and optionally, flowing an oxidizing agent across the membrane before, during, or after deformation of the membrane. A method of supporting a hydrogen separation membrane system comprising selecting a hydrogen separation membrane system comprising one or more catalyst outer layers deposited on a hydrogen transport membrane layer and sealing the hydrogen separation membrane system to a porous support.

  2. CENTRIFUGAL SEPARATORS

    Science.gov (United States)

    Skarstrom, C.

    1959-03-10

    A centrifugal separator is described for separating gaseous mixtures where the temperature gradients both longitudinally and radially of the centrifuge may be controlled effectively to produce a maximum separation of the process gases flowing through. Tbe invention provides for the balancing of increases and decreases in temperature in various zones of the centrifuge chamber as the result of compression and expansions respectively, of process gases and may be employed effectively both to neutralize harmful temperature gradients and to utilize beneficial temperaturc gradients within the centrifuge.

  3. Ionic liquids as additive in thin layer chromatography on separation of amino acids%离子液体作薄层色谱添加剂对氨基酸分离的研究

    Institute of Scientific and Technical Information of China (English)

    刘建平; 何丽君

    2011-01-01

    The separation of two alkaline amino acids ( argi-nine and lysine) was performed using 1-butyl-3-methylimid-azolium tetrafluoroborate ionic liquid ( [ Bmim ] BF4 ) as the eluent additives in thin layer chromatography. The addition of ionic liquid improved the separation the free silanol group markedly. The retardation factor ( R1) of the analytes firstly increased and then remained constant with the increase of the concentration of ionic liquids. In addition,the comparison results showed that the inhibition effect of [ Bmim ] PF6 for free silanol group was more effective than that of [ Bmim] BF4.%将1-丁基-3-甲基咪唑基四氟硼酸盐([Bmim]BF4)离子液体作为薄层色谱展开剂添加剂,讨论了[Bmim]BF4浓度对精氨酸和赖氨酸两种碱性氨基酸分离的影响.结果表明:添加离子液体能有效改善碱性氨基酸的展开效果,而且分析物的Rf值随离子液体浓度的增加而增加,浓度增加到一定后Rf保持不变.另外,比较了[Bmim]PF6和[Bmim]BF4两种离子液体对自由硅羟基抑制作用的效果,前者对自由硅羟基的抑制作用比后者更有效.

  4. Separation techniques: Chromatography

    Science.gov (United States)

    Coskun, Ozlem

    2016-01-01

    Chromatography is an important biophysical technique that enables the separation, identification, and purification of the components of a mixture for qualitative and quantitative analysis. Proteins can be purified based on characteristics such as size and shape, total charge, hydrophobic groups present on the surface, and binding capacity with the stationary phase. Four separation techniques based on molecular characteristics and interaction type use mechanisms of ion exchange, surface adsorption, partition, and size exclusion. Other chromatography techniques are based on the stationary bed, including column, thin layer, and paper chromatography. Column chromatography is one of the most common methods of protein purification. PMID:28058406

  5. Study on Thin-layer Chromatography Separation and Anti-bacterial Activity of Mentha spicata Linn Essential Oil%留兰香挥发油的薄层分离及抗菌活性研究

    Institute of Scientific and Technical Information of China (English)

    张晓伟; 李青雨; 王德国; 石倩倩; 王佳华

    2011-01-01

    [目的]对留兰香挥发油的组分及抗菌活性进行研究.[方法]采用薄层色谱法对留兰香挥发油的组分进行初步分离,采用扩散法及紫外可见分光光度法对留兰香挥发油的抗菌活性进行测定.[结果]以石油醚:乙酸乙酯(V:V=6:1)为层析液时,留兰香挥发油的分离效果最好,分离出4种主要物质;留兰香精油对3种试验菌株的抑菌性为枯草芽孢杆菌(Bacillus subtdis)>金黄色葡萄球菌(Staphylococcus aureus)>大肠杆菌(Escherichia coli);对枯草芽孢杆菌、金黄色葡萄球菌、大肠杆菌的最低抑菌浓度(MIC)分别为:0.50,1.00,3.50μl/ml.[结论]留兰香挥发油具有抑菌作用,这为综合开发留兰香提供了理论基础.%[ Objective ] To study the composition and the anti-bacterial activity of volatile oil from Mentha spicata Linn. [ Method ] Using thin-layer chromatography ( TLC ), the compositions of essential oil from Mentha spicata Linn were separated. The inhibitory activity was determined by diffusion method combining with UV spectrophotometry. [ Result] Using petroleum ether- ethyl acetate ( V: V =6:1 ) as chromatography liquid, the essential oil from Mentha spicata Linn was best in separation and four components were obtained. The inhibitory effect of volatile oil from Mentha spicata Linn to three test strains was determined to be Bacillus subtilis > Staphylococcus aureus > Escherichia coli with MIC value of 0.50, 1.00 and 3.50 ul/ml, respectively. [ Conclusion ] The volatile oil from Mentha spicata Linn had anti-bacterial effect, which provided theoretical basis for comprehensive development of Mentha spicata Linn.

  6. Flow Separation

    Science.gov (United States)

    1975-11-01

    Born, Constantin Caratheodory, Richard Couiant, Kurt Friedrichs, Werner Heisenberg, Gustav Herglotz, Erich von Hoist, Pascual Jordan, Walther Nernst...existence of these two flow regimes in boundary layers was discovered by PRANDTL when EIFFEL [8] published in 1912 his measurements on the drag of...simultaneously by G. EIFFEL in Paris and became so successful that other wind tunnels were modelled after it in many countries. Fig. 18 gives an impression of

  7. GPS Separator

    CERN Multimedia

    2016-01-01

    Footage of the 70 degree ISOLDE GPS separator magnet MAG70 as well as the switchyard for the Central Mass and GLM (GPS Low Mass) and GHM (GPS High Mass) beamlines in the GPS separator zone. In the GPS20 vacuum sector equipment such as the long GPS scanner 482 / 483 unit, faraday cup FC 490, vacuum valves and wiregrid piston WG210 and WG475 and radiation monitors can also be seen. Also the RILIS laser guidance and trajectory can be seen, the GPS main beamgate switch box and the actual GLM, GHM and Central Beamline beamgates in the beamlines as well as the first electrostatic quadrupoles for the GPS lines. Close up of the GHM deflector plates motor and connections and the inspection glass at the GHM side of the switchyard.

  8. HRS Separator

    CERN Multimedia

    2016-01-01

    Footage of the 90 and 60 degree ISOLDE HRS separator magnets in the HRS separator zone. In the two vacuum sectors HRS20 and HRS30 equipment such as the HRS slits SL240, the HRS faraday cup FC300 and wiregrid WG210 can be spotted. Vacuum valves, turbo pumps, beamlines, quadrupoles, water and compressed air connections, DC and signal cabling can be seen throughout the video. The HRS main and user beamgate in the beamline between MAG90 and MAG60 and its switchboxes as well as all vacuum bellows and flanges are shown. Instrumentation such as the HRS scanner unit 482 / 483, the HRS WG470 wiregrid and slits piston can be seen. The different quadrupoles and supports are shown as well as the RILIS guidance tubes and installation at the magnets and the different radiation monitors.

  9. 茶叶中儿茶素薄层色谱分离所用展开剂的优化%Optimization of developing solvents of high performance thin-layer chromatography for separating catechins in tea

    Institute of Scientific and Technical Information of China (English)

    王丽丽; 王坤波; 黄建安; 徐仲溪

    2012-01-01

    室温条件下,以硅胶板为固定相,用5种展开剂(体积比9:9:2的甲苯-丙酮-甲酸、5.0:10.0:1.0:0.5的甲苯-甲酸乙酯-甲醇-甲酸、8.0:5.0:15.0:0.3的甲苯-三氯钾烷-丙酮-甲酸、12.5:7.5:1.8:0.6的三氯钾烷-丙酮-甲醇-水、12.5:7.5:1.8:0.6的三氯钾烷-丙酮-甲酸-水)对茶叶中的儿茶素进行薄层色谱分离,筛选出其中较优的展开剂后,进一步优化其配比,并用其分离绿茶和白茶提取物中的儿茶素以进行验证.结果表明,以体积比12.5:7.5:2.2的三氯甲烷-丙酮-甲酸为展开剂,茶叶内主要的4种儿茶素单体(EGCg、EGC、ECg、EC)可得到良好分离,绿茶与白茶提取物中的儿茶素能较好地得以分离.%At room temperature, methylbenzene-acetone-formic acid (9∶9 ∶ 2, V/V), methylbenzene-ethyl formatemethanol-formic acid (5.0 ∶10.0∶ 1.0 ∶0.5, V/V), methylbenzene-chloroform-acetone-formic acid (8.0 ∶5.0∶ 15.0∶ 0.3, V/V), chloroform-acetone-methanol-water(12.5 ∶7.5 ∶1.8 ∶ 0.6, V/V) and chloroform-acetone-formic acid-water (12.5 ∶ 7.5 ∶ 1.8 ∶ 0.6, V/V) on silica gel marked as solvent Ⅰ,Ⅱ,Ⅲ,Ⅳ and Ⅴ respectively were applied as developing solvent respectively in high performance thin-layer chromatography (HPTLC) for isolating catechins in the tea. Among them, solvent Ⅴ was found to be the best for separation of catechins, this solvent was then modified mainly regarding the volume ratios of formic acid. The results showed the modified solvent Ⅴ, namely, chloroform- acetone- formic acid (12.5 ∶ 7.5 ∶2.2, V/V) was the optimum for separation of the four main catechins (EGCg, EGC, Ecg, EC) in the tea. The applicability of the optimized developing solvent was further confirmed by separation of catechins in the extracts of the green and the white tea.

  10. Organic Separation Test Results

    Energy Technology Data Exchange (ETDEWEB)

    Russell, Renee L.; Rinehart, Donald E.; Peterson, Reid A.

    2014-09-22

    Separable organics have been defined as “those organic compounds of very limited solubility in the bulk waste and that can form a separate liquid phase or layer” (Smalley and Nguyen 2013), and result from three main solvent extraction processes: U Plant Uranium Recovery Process, B Plant Waste Fractionation Process, and Plutonium Uranium Extraction (PUREX) Process. The primary organic solvents associated with tank solids are TBP, D2EHPA, and NPH. There is concern that, while this organic material is bound to the sludge particles as it is stored in the tanks, waste feed delivery activities, specifically transfer pump and mixer pump operations, could cause the organics to form a separated layer in the tank farms feed tank. Therefore, Washington River Protection Solutions (WRPS) is experimentally evaluating the potential of organic solvents separating from the tank solids (sludge) during waste feed delivery activities, specifically the waste mixing and transfer processes. Given the Hanford Tank Waste Treatment and Immobilization Plant (WTP) waste acceptance criteria per the Waste Feed Acceptance Criteria document (24590-WTP-RPT-MGT-11-014) that there is to be “no visible layer” of separable organics in the waste feed, this would result in the batch being unacceptable to transfer to WTP. This study is of particular importance to WRPS because of these WTP requirements.

  11. 分散聚合法合成含有环氧基的无孔超顺磁性微球及其表征%Preparation and Characterization of Non-porous Superparamagnetic Microspheres with Epoxy Groups by Dispersion Polymerization

    Institute of Scientific and Technical Information of China (English)

    马志亚; 官月平; 刘先桥; 刘会洲

    2005-01-01

    Non-porous superparamagnetic polymer microspheres with epoxy groups were prepared by dispersion polymerization of glycidyl methacrylate (GMA) in the presence of magnetic iron oxide (Fe3 O4) nanoparticles coated with oleic acid. The polymerization was carried out in the ethanol/water medium using polyvinylpyrrolidone (PVP)and 2,2'-azobisisobutyronitrile (AIBN) as stabilizer and initiator, respectively. The magnetic microspheres obtained were characterized with scanning electron microscopy (SEM), vibrating sample magnetometry (VSM) and Fourier transform infrared spectroscopy (FTIR). The results showed that the magnetic microspheres had an average size of have extensive potential uses in magnetic bioseparation and biotechnology.

  12. A new method of separation and quantitation of mucus glycoprotein in rat gastric mucus gel layer and its application to mucus secretion induced by 16,16-dimethyl PGE2.

    Science.gov (United States)

    Komuro, Y; Ishihara, K; Ohara, S; Saigenji, K; Hotta, K

    1991-10-01

    A method was established for recovering the mucus gel layer of rat gastric mucosa without damage to underlying surface epithelium. The mucus gel was solubilized by stirring the gastric mucosa in a solution of N-acetylcysteine (NAC), a mucolytic agent. Optimal mucus gel solubilization was possible by treatment with 2% NAC for 5 minutes at room temperature. Mucus glycoprotein was quantitatively extracted and measured from the mucus gel sample obtained by the NAC treatment. This treatment caused no damage to surface epithelial cells, as observed by a light microscope. Besides NAC, pronase solution was also adequate for solubilizing the mucus gel layer without any damage to the surface epithelium. However, extraction and measurement of mucus glycoprotein from the pronase-treated mucus gel sample was not possible due to contamination by high molecular hexose-containing substances which were eluted along with the mucus glycoprotein from the column of Bio-Gel A-1.5m. This NAC method was used to examine changes in mucus glycoprotein content in the mucus gel at one hour following the oral administration of 16,16-dimethyl prostaglandin E2. A significant increase in mucus glycoprotein of the gel was brought about by the prostaglandin treatment. Thus, the present method was suitable for estimating the amount of mucus secreted in to the mucus gel layer.

  13. Double-Layer Systems at Zero Magnetic Field

    OpenAIRE

    ~Hanna, C. ~B.; Haas, Dylan; Diaz-Velez, J.C.

    2000-01-01

    We investigate theoretically the effects of intralayer and interlayer exchange in biased double-layer electron and hole systems, in the absence of a magnetic field. We use a variational Hartree-Fock-like approximation to analyze the effects of layer separation, layer density, tunneling, and applied gate voltages on the layer densities and on interlayer phase coherence. In agreement with earlier work, we find that for very small layer separations and low layer densities, an interlayer-correlat...

  14. 边界层分离点实时数据采集与处理系统的设计与实现%Real Time Signal Collection and Processing System for Detecting Boundary Layer Separation Point of Micro-Aircraft

    Institute of Scientific and Technical Information of China (English)

    丁英涛; 李博; 王竹萍; 仲顺安

    2011-01-01

    通过分析实时数据采集与处理的基本原理和系统构架,搭建了适用于微型飞行器边界层分离点检测的实时信号采集与处理系统.该系统主要由模拟低通滤波电路、模数转换电路(ADC)、场可编程门阵列(FPGA)控制电路及USB接口电路构成.测试结果为:基准电平0.1mV,峰峰值407 mV,频率1 kHz,满足边界层分离点实时检测和判定的要求.%The accurate detection of the boundary layer separation point in real time has a great benefit to improve micro-aircraft's climb, maneuvering and pneumatic abilities. By analyzing the principle and framework of real time data collecting and processing system, a real time signal collecting and processing system, which could be applied to detect the boundary layer separation point of micro-aircrafts, has been proposed and developed. The system mainly consists of analog low-pass filter, analog to digital converter (ADC), FPGA controlling circuits and USB interface circuits. The testing results show that the performance of developed system is good, which is well suitable for detecting and estimating the boundary layer separation point in real time.

  15. Air-stable conversion of separated carbon nanotube thin-film transistors from p-type to n-type using atomic layer deposition of high-κ oxide and its application in CMOS logic circuits.

    Science.gov (United States)

    Zhang, Jialu; Wang, Chuan; Fu, Yue; Che, Yuchi; Zhou, Chongwu

    2011-04-26

    Due to extraordinary electrical properties, preseparated, high purity semiconducting carbon nanotubes hold great potential for thin-film transistors (TFTs) and integrated circuit applications. One of the main challenges it still faces is the fabrication of air-stable n-type nanotube TFTs with industry-compatible techniques. Here in this paper, we report a novel and highly reliable method of converting the as-made p-type TFTs using preseparated semiconducting nanotubes into air-stable n-type transistors by adding a high-κ oxide passivation layer using atomic layer deposition (ALD). The n-type devices exhibit symmetric electrical performance compared with the p-type devices in terms of on-current, on/off ratio, and device mobility. Various factors affecting the conversion process, including ALD temperature, metal contact material, and channel length, have also been systematically studied by a series of designed experiments. A complementary metal-oxide-semiconductor (CMOS) inverter with rail-to-rail output, symmetric input/output behavior, and large noise margin has been further demonstrated. The excellent performance gives us the feasibility of cascading multiple stages of logic blocks and larger scale integration. Our approach can serve as the critical foundation for future nanotube-based thin-film macroelectronics.

  16. The multiple layer solar collector

    Science.gov (United States)

    Kenna, J. P.

    1983-01-01

    An analytical model is developed for obtaining numerical solutions for differential equations describing the performance of separate layers in a multiple layer solar collector. The configurations comprises heat transfer fluid entering at the top of the collector and travelling down through several layers. A black absorber plate prevents reemission of thermal radiation. The overall performance is shown to depend on the number of layers, the heat transfer coefficient across each layer, and the absorption properties of the working fluid. It is found that the multiple layer system has a performance inferior to that of flat plate selective surface collectors. Air gaps insulating adjacent layers do not raise the efficiency enough to overcome the relative deficiency.

  17. Fictional Separation Logic

    DEFF Research Database (Denmark)

    Jensen, Jonas Buhrkal; Birkedal, Lars

    2012-01-01

    , separation means physical separation. In this paper, we introduce \\emph{fictional separation logic}, which includes more general forms of fictional separating conjunctions P * Q, where "*" does not require physical separation, but may also be used in situations where the memory resources described by P and Q...

  18. Enhancing spin state phase separation by strontium addition in the Y (Ba{sub 1-x}Sr{sub x})Co{sub 2}O{sub 5.5} layered cobaltite

    Energy Technology Data Exchange (ETDEWEB)

    Aurelio, G; Curiale, J; Sanchez, R D [Consejo Nacional de Investigaciones Cientificas y Tecnicas, Centro Atomico Bariloche-Comision Nacional de Energia Atomica, Avenida Bustillo 9500, 8400 San Carlos de Bariloche, RN (Argentina); Cuello, G J, E-mail: gaurelio@cab.cnea.gov.a [Department of Applied Physics II, Ikerbasque, UPV/EHU, E-48080 Bilbao (Spain)

    2009-08-12

    In this paper we present a neutron diffraction study of the effects of replacing Ba with smaller Sr cations in the layered cobaltite YBaCo{sub 2}O{sub 5+{delta}} for {delta}{approx}0.5. Neutron thermodiffractograms are reported in the temperature range 20 K<=T<=300 K, as well as high-resolution neutron diffraction experiments at selected temperatures. The systematic refinement of the series of samples with Sr substituting at the Ba site permits the understanding of the complex magnetic behaviour of this system, and reinforces a two-phase scenario for the parent compound. We have found that Sr addition destabilizes the ferrimagnetic spin state ordered phase, as well as the '122' order characteristic of cobaltites with delta = 0.5, favouring instead a tetragonal and less ordered structure.

  19. Analysis and Methane Gas Separations Studies for City of Marsing, Idaho An Idaho National Laboratory Technical Assistance Program Study

    Energy Technology Data Exchange (ETDEWEB)

    Christopher Orme

    2012-08-01

    Introduction and Background Large amounts of methane in well water is a wide spread problem in North America. Methane gas from decaying biomass and oil and gas deposits escape into water wells typically through cracks or faults in otherwise non-porous rock strata producing saturated water systems. This methane saturated water can pose several problems in the delivery of drinking water. The problems range from pumps vapor locking (cavitating), to pump houses exploding. The City of Marsing requested Idaho National Laboratory (INL) to assist with some water analyses as well as to provide some engineering approaches to methane capture through the INL Technical Assistance Program (TAP). There are several engineering approaches to the removal of methane and natural gas from water sources that include gas stripping followed by compression and/or dehydration; membrane gas separators coupled with dehydration processes, membrane water contactors with dehydration processes.

  20. Separation Anxiety (For Parents)

    Science.gov (United States)

    ... Kids to Be Smart About Social Media Separation Anxiety KidsHealth > For Parents > Separation Anxiety Print A A ... both of you get through it. About Separation Anxiety Babies adapt pretty well to other caregivers. Parents ...

  1. Separation Anxiety (For Parents)

    Science.gov (United States)

    ... Feeding Your 1- to 2-Year-Old Separation Anxiety KidsHealth > For Parents > Separation Anxiety A A A ... both of you get through it. About Separation Anxiety Babies adapt pretty well to other caregivers. Parents ...

  2. Cyclone with boundary layer displacement

    Energy Technology Data Exchange (ETDEWEB)

    Gorton-Huelgerth, A.; Hoffmann, D.; Staudinger, G. [Technische Universitaet Graz, Graz (Austria). Inst. fuer Verfahrenstechnik, Abt. fuer Apparatebau und Mechanische Verfahrenstechnik

    1998-12-31

    In a cyclone the boundary layers at the cover plate and outside of the vortex finder are considered to affect the separation efficiency of a cyclone. To improve separation efficiency, the boundary layers at and the space between vortex finder and cover plate were investigated. Two identical cyclones, 400 mm diameter and 990 mm long were manufactured with high precision from stainless steel. One was equipped with openings for insertion of velocity probes; the opening could be closed with glass windows to allow Laser Doppler Anemometry. The other cyclone was used for testing separation efficiency. Velocity measurements by both conventional pressure probes and Laser Doppler Anemometry revealed that only a minor part of the boundary layer at the outside of the vortex finder reaches the lower end of it, because the axial velocity is slowed down drastically. Light sheet visualization showed that there exists a heavily particle loaded boundary layer at the cover plate. There are no particles at the lower part of the vortex finder. This can be explained by the radial mass exchange. The effect of vortex finder length on separation efficiency was investigated by varying the length of the vortex finder and measuring the separation efficiency using a limestone powder as test material. It was found that the separation efficiency is not sensitive to the length of the vortex finder. Particle slip increases only where the vortex finder is definitely shorter than its diameter. It was tried to improve the separation efficiency by introducing an air curtain along the vortex finder. The positive effect on separation efficiency and particle cut size is minimal. Results from velocity measurements with cylinder pressure probes in the boundary layer do not fit the results from other measurement techniques. Many older measurements were made with these probes. The conclusions drawn and the design rules deduced are to be questioned. 17 refs., 21 figs., 2 tabs.

  3. Nonmixing layers

    Science.gov (United States)

    Gaillard, Pierre; Giovangigli, Vincent; Matuszewski, Lionel

    2016-12-01

    We investigate the impact of nonideal diffusion on the structure of supercritical cryogenic binary mixing layers. This situation is typical of liquid fuel injection in high-pressure rocket engines. Nonideal diffusion has a dramatic impact in the neighborhood of chemical thermodynamic stability limits where the components become quasi-immiscible and ultimately form a nonmixing layer. Numerical simulations are performed for mixing layers of H2 and N2 at a pressure of 100 atm and temperature around 120-150 K near chemical thermodynamic stability limits.

  4. Controlling Separation in Turbomachines

    Science.gov (United States)

    Evans, Simon; Himmel, Christoph; Power, Bronwyn; Wakelam, Christian; Xu, Liping; Hynes, Tom; Hodson, Howard

    2010-01-01

    Four examples of flow control: 1) Passive control of LP turbine blades (Laminar separation control). 2) Aspiration of a conventional axial compressor blade (Turbulent separation control). 3) Compressor blade designed for aspiration (Turbulent separation control). 4.Control of intakes in crosswinds (Turbulent separation control).

  5. Application of separate layer fracturing technology with Y341 double packer by one trip string in North Jiangsu oil field%Y341双封一趟管柱分压工艺在苏北油田的应用

    Institute of Scientific and Technical Information of China (English)

    张建; 张宏录

    2015-01-01

    由于苏北阜宁组储层埋藏深、物性差、薄互油层多、低孔低渗,具有采收率低、裂缝延伸压力高、改造难度大、单井产能低等特点。采用常规分层压裂工艺,作业工序多、周期长,部分低渗储层改造不充分,造成措施效果不理想。为缓解层间矛盾,加强低孔低渗层压裂改造效果,采取Y341双封一趟管柱分层改造技术手段,借助裂缝设计软件模拟优化工艺参数进行储层改造。这项工艺技术的成功应用极大地缩短了作业周期,节省成本,提高了储层的改造程度。返排完机抽,改造初期与周围井相比平均多产油5.9 t/d,且产量较稳定。%With deep buried, bad property, multiple thin interbedded reservoir and low permeability reservoir, Funing group of North Jiangsu oil field has the characteristics of low recovery efficiency, high fracture extension pressure, difficult transformation, and low single-well productivity. Common separate layer fracturing process takes more work processes and long operating cycles, or causes inadequate of part of low permeability reservoir transformation, resulting that measures are not ideal. To ease the contra⁃diction between layers and strengthen the fracturing effects of the low porosity and permeability layer, the reservoir was reconstruct⁃ed by taking separate layer fracturing technology with Y341 double packer by one trip string and the crack design software to simu⁃late and optimize process parameters. The successful application of this technology greatly shortens the operating cycle, reduces cost savings, and improves the degree of reservoir transformation. After flowback and followed by the machine pumping, the oil pro⁃duction was 5.9 t/d more than average compared to the adjacent wells in the early transformation with stable yield.

  6. Ontology of the Layer. A Post-Human Object

    Directory of Open Access Journals (Sweden)

    Leonardo Caffo

    2015-09-01

    Full Text Available What is a layer? A separator or something separated? Is there such a thing as a layer or is it a different concept, or rather object, depending on the discipline? There are two philosophical questions regarding the layer: Does it exist? (ontology and What is it? (metaphysics.

  7. Some thoughts on separation control strategies

    Indian Academy of Sciences (India)

    P R Viswanath

    2007-02-01

    Separation control has received considerable emphasis in literature both owing to fundamental flow physics and technological applications. Flow separation generally leads to increased energy losses, instability and so on, and its control is essential to improve aerodynamic performance. Here a brief review is presented of three broad strategies for separation control: these include methods that involve energization of the boundary layer upstream of separation, those that involve altering the bubble flow or dead air zone, and those that may influence the shear layer reattachment directly. Examples from recent research in our laboratories are reviewed and it is suggested that direct manipulation of the reattachment process could lead to effective control/management.

  8. Experimental Research on Flow Separation Control using Synthetic Jet Actuators

    NARCIS (Netherlands)

    Koopmans, E.; Hoeijmakers, H.W.M.

    2014-01-01

    Airplane wings can suffer from flow separation, which greatly decreases their aerodynamic per-formance. The flow separates due to the bound-ary layer possessing insufficient momentum to engage the adverse pressure gradient along the airfoil surface. Flow separation control actively influences the fl

  9. Experimental research on flow separation control using synthetic jet actuators

    NARCIS (Netherlands)

    Koopmans, E.; Hoeijmakers, H.W.M.

    2014-01-01

    Airplane wings can suffer from flow separation, which greatly decreases their aerodynamic per-formance. The flow separates due to the bound-ary layer possessing insufficient momentum to engage the adverse pressure gradient along the airfoil surface. Flow separation control actively influences the fl

  10. Wetting and phase separation at surfaces

    Indian Academy of Sciences (India)

    Sanjay Puri; Kurt Binder

    2005-06-01

    We study the problem of surface-directed spinodal decomposition, viz., the dynamical interplay of wetting and phase separation at surfaces. In particular, we focus on the kinetics of wetting-layer growth in a semi-infinite geometry for arbitrary surface potentials and mixture compositions. We also present representative results for phase separation in confined geometries, e.g., cylindrical pores, thin films, etc.

  11. A three-layered nano-carbonated hydroxyapatite/collagen/PLGA composite membrane for guided tissue regeneration.

    Science.gov (United States)

    Liao, Susan; Wang, Wei; Uo, Motohiro; Ohkawa, Shoji; Akasaka, Tsukasa; Tamura, Kazuchika; Cui, Fuzhai; Watari, Fumio

    2005-12-01

    Functional graded materials (FGM) provided us one new concept for guided tissue regeneration (GTR) membrane design with graded component and graded structure where one face of the membrane is porous thereby allowing cell growth thereon and the opposite face of the membrane is smooth, thereby inhibiting cell adhesion in periodontal therapy. The goal of the present study was to develop a three-layered graded membrane, with one face of 8% nano-carbonated hydroxyapatite/collagen/poly(lactic-co-glycolic acid) (nCHAC/PLGA) porous membrane, the opposite face of pure PLGA non-porous membrane, the middle layer of 4% nCHAC/PLGA as the transition through layer-by-layer casting method. Then the three layers were combined well with each other with flexibility and enough high mechanical strength as membrane because the three layers all contained PLGA polymer that can be easily used for practical medical application. This high biocompatibility and osteoconductivity of this biodegraded composite membrane was enhanced by the nCHAC addition, for the same component and nano-level crystal size with natural bone tissue. The osteoblastic MC3T3-E1 cells were cultured on the three-layered composite membrane, the primary result shows the positive response compared with pure PLGA membrane.

  12. Wet separation processes as method to separate limestone and oil shale

    Science.gov (United States)

    Nurme, Martin; Karu, Veiko

    2015-04-01

    Biggest oil shale industry is located in Estonia. Oil shale usage is mainly for electricity generation, shale oil generation and cement production. All these processes need certain quality oil shale. Oil shale seam have interlayer limestone layers. To use oil shale in production, it is needed to separate oil shale and limestone. A key challenge is find separation process when we can get the best quality for all product types. In oil shale separation typically has been used heavy media separation process. There are tested also different types of separation processes before: wet separation, pneumatic separation. Now oil shale industry moves more to oil production and this needs innovation methods for separation to ensure fuel quality and the changes in quality. The pilot unit test with Allmineral ALLJIG have pointed out that the suitable new innovation way for oil shale separation can be wet separation with gravity, where material by pulsating water forming layers of grains according to their density and subsequently separates the heavy material (limestone) from the stratified material (oil shale)bed. Main aim of this research is to find the suitable separation process for oil shale, that the products have highest quality. The expected results can be used also for developing separation processes for phosphorite rock or all others, where traditional separation processes doesn't work property. This research is part of the study Sustainable and environmentally acceptable Oil shale mining No. 3.2.0501.11-0025 http://mi.ttu.ee/etp and the project B36 Extraction and processing of rock with selective methods - http://mi.ttu.ee/separation; http://mi.ttu.ee/miningwaste/

  13. Outer layer effects in wind-farm boundary layers: Coriolis forces and boundary layer height

    Science.gov (United States)

    Allaerts, Dries; Meyers, Johan

    2015-11-01

    In LES studies of wind-farm boundary layers, scale separation between the inner and outer region of the atmospheric boundary layer (ABL) is frequently assumed, i.e., wind turbines are presumed to fall within the inner layer and are not affected by outer layer effects. However, modern wind turbine and wind farm design tends towards larger rotor diameters and farm sizes, which means that outer layer effects will become more important. In a prior study, it was already shown for fully-developed wind farms that the ABL height influences the power performance. In this study, we use the in-house LES code SP-Wind to investigate the importance of outer layer effects on wind-farm boundary layers. In a suite of LES cases, the ABL height is varied by imposing a capping inversion with varying inversion strengths. Results indicate the growth of an internal boundary layer (IBL), which is limited in cases with low inversion layers. We further find that flow deceleration combined with Coriolis effects causes a change in wind direction throughout the farm. This effect increases with decreasing boundary layer height, and can result in considerable turbine wake deflection near the end of the farm. The authors are supported by the ERC (ActiveWindFarms, grant no: 306471). Computations were performed on VSC infrastructiure (Flemish Supercomputer Center), funded by the Hercules Foundation and the Flemish Government-department EWI.

  14. Separation anxiety in children

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/001542.htm Separation anxiety in children To use the sharing features on this page, please enable JavaScript. Separation anxiety in children is a developmental stage in which ...

  15. Ionene membrane battery separator

    Science.gov (United States)

    Moacanin, J.; Tom, H. Y.

    1969-01-01

    Ionic transport characteristics of ionenes, insoluble membranes from soluble polyelectrolyte compositions, are studied for possible application in a battery separator. Effectiveness of the thin film of separator membrane essentially determines battery lifetime.

  16. Magnetic separation of algae

    Energy Technology Data Exchange (ETDEWEB)

    Nath, Pulak; Twary, Scott N.

    2016-04-26

    Described herein are methods and systems for harvesting, collecting, separating and/or dewatering algae using iron based salts combined with a magnetic field gradient to separate algae from an aqueous solution.

  17. Kinetic Gravity Separation

    NARCIS (Netherlands)

    Van Kooy, L.; Mooij, M.; Rem, P.

    2004-01-01

    Separations by density, such as the separation of non-ferrous scrap into light and heavy alloys, are often realized by means of heavy media. In principle, kinetic gravity separations in water can be faster and cheaper, because they do not rely on suspensions or salt solutions of which the density

  18. Identification of low molecular weight proteins isolated by 2-D liquid separations.

    Science.gov (United States)

    Zhu, Kan; Miller, Fred R; Barder, Timothy J; Lubman, David M

    2004-07-01

    Proteins with molecular mass (M(r)) <20 kDa are often poorly separated in 2-D sodium dodecyl sulfate polyacrylamide gel electrophoresis. In addition, low-M(r) proteins may not be readily identified using peptide mass fingerprinting (PMF) owing to the small number of peptides generated in tryptic digestion. In this work, we used a 2-D liquid separation method based on chromatofocusing and non-porous silica reversed-phase high-performance liquid chromatography to purify proteins for matrix-assisted laser desorption/ionization time-of-flight mass spectrometric (MALDI-TOFMS) analysis and protein identification. Several proteins were identified using the PMF method where the result was supported using an accurate M(r) value obtained from electrospray ionization TOFMS. However, many proteins were not identified owing to an insufficient number of peptides observed in the MALDI-TOF experiments. The small number of peptides detected in MALDI-TOFMS can result from internal fragmentation, the few arginines in its sequence and incomplete tryptic digestion. MALDI-QTOFMS/MS can be used to identify many of these proteins. The accurate experimental M(r) and pI confirm identification and aid in identifying post-translational modifications such as truncations and acetylations. In some cases, high-quality MS/MS data obtained from the MALDI-QTOF spectrometer overcome preferential cleavages and result in protein identification.

  19. Efficient solar water splitting by enhanced charge separation in a bismuth vanadate-silicon tandem photoelectrode.

    Science.gov (United States)

    Abdi, Fatwa F; Han, Lihao; Smets, Arno H M; Zeman, Miro; Dam, Bernard; van de Krol, Roel

    2013-01-01

    Metal oxides are generally very stable in aqueous solutions and cheap, but their photochemical activity is usually limited by poor charge carrier separation. Here we show that this problem can be solved by introducing a gradient dopant concentration in the metal oxide film, thereby creating a distributed n(+)-n homojunction. This concept is demonstrated with a low-cost, spray-deposited and non-porous tungsten-doped bismuth vanadate photoanode in which carrier-separation efficiencies of up to 80% are achieved. By combining this state-of-the-art photoanode with an earth-abundant cobalt phosphate water-oxidation catalyst and a double- or single-junction amorphous Si solar cell in a tandem configuration, stable short-circuit water-splitting photocurrents of ~4 and 3 mA cm(-2), respectively, are achieved under 1 sun illumination. The 4 mA cm(-2) photocurrent corresponds to a solar-to-hydrogen efficiency of 4.9%, which is the highest efficiency yet reported for a stand-alone water-splitting device based on a metal oxide photoanode.

  20. Efficient solar water splitting by enhanced charge separation in a bismuth vanadate-silicon tandem photoelectrode

    Science.gov (United States)

    Abdi, Fatwa F.; Han, Lihao; Smets, Arno H. M.; Zeman, Miro; Dam, Bernard; van de Krol, Roel

    2013-07-01

    Metal oxides are generally very stable in aqueous solutions and cheap, but their photochemical activity is usually limited by poor charge carrier separation. Here we show that this problem can be solved by introducing a gradient dopant concentration in the metal oxide film, thereby creating a distributed n+-n homojunction. This concept is demonstrated with a low-cost, spray-deposited and non-porous tungsten-doped bismuth vanadate photoanode in which carrier-separation efficiencies of up to 80% are achieved. By combining this state-of-the-art photoanode with an earth-abundant cobalt phosphate water-oxidation catalyst and a double- or single-junction amorphous Si solar cell in a tandem configuration, stable short-circuit water-splitting photocurrents of ~4 and 3 mA cm-2, respectively, are achieved under 1 sun illumination. The 4 mA cm-2 photocurrent corresponds to a solar-to-hydrogen efficiency of 4.9%, which is the highest efficiency yet reported for a stand-alone water-splitting device based on a metal oxide photoanode.

  1. Rapid chemical separations

    CERN Document Server

    Trautmann, N

    1976-01-01

    A survey is given on the progress of fast chemical separation procedures during the last few years. Fast, discontinuous separation techniques are illustrated by a procedure for niobium. The use of such techniques for the chemical characterization of the heaviest known elements is described. Other rapid separation methods from aqueous solutions are summarized. The application of the high speed liquid chromatography to the separation of chemically similar elements is outlined. The use of the gas jet recoil transport method for nuclear reaction products and its combination with a continuous solvent extraction technique and with a thermochromatographic separation is presented. Different separation methods in the gas phase are briefly discussed and the attachment of a thermochromatographic technique to an on-line mass separator is shown. (45 refs).

  2. Acoustofluidic bacteria separation

    Science.gov (United States)

    Li, Sixing; Ma, Fen; Bachman, Hunter; Cameron, Craig E.; Zeng, Xiangqun; Huang, Tony Jun

    2017-01-01

    Bacterial separation from human blood samples can help with the identification of pathogenic bacteria for sepsis diagnosis. In this work, we report an acoustofluidic device for label-free bacterial separation from human blood samples. In particular, we exploit the acoustic radiation force generated from a tilted-angle standing surface acoustic wave (taSSAW) field to separate Escherichia coli from human blood cells based on their size difference. Flow cytometry analysis of the E. coli separated from red blood cells shows a purity of more than 96%. Moreover, the label-free electrochemical detection of the separated E. coli displays reduced non-specific signals due to the removal of blood cells. Our acoustofluidic bacterial separation platform has advantages such as label-free separation, high biocompatibility, flexibility, low cost, miniaturization, automation, and ease of in-line integration. The platform can be incorporated with an on-chip sensor to realize a point-of-care sepsis diagnostic device.

  3. Exploring Pore Formation of Atomic Layer Deposited Overlayers by In Situ Small- and Wide-Angle X-ray Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Li, Tao; Karwal, Saurabh; Aoun, Bachir; Zhao, Haiyan; Ren, Yang; Canlas, Christian; Elam, Jeffrey W.; Winans, Randall E.

    2016-10-11

    In this work, we explore the pore structure of overcoated materials by in situ synchrotron small- and wide-angle X-ray scattering (SAXS)/(WAXS). Thin films of aluminum oxide (Al2O3) and titanium dioxide (TiO2) with thicknesses of 4.9 and 2.5 nm, respectively, are prepared by atomic layer deposition (ALD) on non-porous nanoparticles. In situ X-ray measurements reveal that porosity is induced in the ALD films by annealing the samples at high temperature. Moreover, this pore formation can be attributed to densification resulting from an amorphous to crystalline phase transition of the ALD films as confirmed by high resolution X-ray diffraction (XRD) and pair distribution function (PDF). Simultaneous SAXS/WAXS results not only show that the porosity is formed by this phase transition but also that the pore size increases with temperature.

  4. Boundary layer transition studies

    Science.gov (United States)

    Watmuff, Jonathan H.

    1995-02-01

    A small-scale wind tunnel previously used for turbulent boundary layer experiments was modified for two sets of boundary layer transition studies. The first study concerns a laminar separation/turbulent reattachment. The pressure gradient and unit Reynolds number are the same as the fully turbulent flow of Spalart and Watmuff. Without the trip wire, a laminar layer asymptotes to a Falkner & Skan similarity solution in the FPG. Application of the APG causes the layer to separate and a highly turbulent and approximately 2D mean flow reattachment occurs downstream. In an effort to gain some physical insight into the flow processes a small impulsive disturbance was introduced at the C(sub p) minimum. The facility is totally automated and phase-averaged data are measured on a point-by-point basis using unprecedently large grids. The evolution of the disturbance has been tracked all the way into the reattachment region and beyond into the fully turbulent boundary layer. At first, the amplitude decays exponentially with streamwise distance in the APG region, where the layer remains attached, i.e. the layer is viscously stable. After separation, the rate of decay slows, and a point of minimum amplitude is reached where the contours of the wave packet exhibit dispersive characteristics. From this point, exponential growth of the amplitude of the disturbance is observed in the detached shear layer, i.e. the dominant instability mechanism is inviscid. A group of large-scale 3D vortex loops emerges in the vicinity of the reattachment. Remarkably, the second loop retains its identify far downstream in the turbulent boundary layer. The results provide a level of detail usually associated with CFD. Substantial modifications were made to the facility for the second study concerning disturbances generated by Suction Holes for laminar flow Control (LFC). The test section incorporates suction through interchangeable porous test surfaces. Detailed studies have been made using isolated

  5. Boundary layer transition studies

    Science.gov (United States)

    Watmuff, Jonathan H.

    1995-01-01

    A small-scale wind tunnel previously used for turbulent boundary layer experiments was modified for two sets of boundary layer transition studies. The first study concerns a laminar separation/turbulent reattachment. The pressure gradient and unit Reynolds number are the same as the fully turbulent flow of Spalart and Watmuff. Without the trip wire, a laminar layer asymptotes to a Falkner & Skan similarity solution in the FPG. Application of the APG causes the layer to separate and a highly turbulent and approximately 2D mean flow reattachment occurs downstream. In an effort to gain some physical insight into the flow processes a small impulsive disturbance was introduced at the C(sub p) minimum. The facility is totally automated and phase-averaged data are measured on a point-by-point basis using unprecedently large grids. The evolution of the disturbance has been tracked all the way into the reattachment region and beyond into the fully turbulent boundary layer. At first, the amplitude decays exponentially with streamwise distance in the APG region, where the layer remains attached, i.e. the layer is viscously stable. After separation, the rate of decay slows, and a point of minimum amplitude is reached where the contours of the wave packet exhibit dispersive characteristics. From this point, exponential growth of the amplitude of the disturbance is observed in the detached shear layer, i.e. the dominant instability mechanism is inviscid. A group of large-scale 3D vortex loops emerges in the vicinity of the reattachment. Remarkably, the second loop retains its identify far downstream in the turbulent boundary layer. The results provide a level of detail usually associated with CFD. Substantial modifications were made to the facility for the second study concerning disturbances generated by Suction Holes for laminar flow Control (LFC). The test section incorporates suction through interchangeable porous test surfaces. Detailed studies have been made using isolated

  6. PRESSURE DRIVEN CONDUCTING POLYMER MEMBRANES DERIVED FROM LAYER BY LAYER FORMATION AND CHARACTERIZATION: A REVIEW

    Directory of Open Access Journals (Sweden)

    IZZATI IZNI YUSOFF

    2016-08-01

    Full Text Available The layer-by-layer method is a technique used for the fabrication of ultra-thin defect free films which involves alternating sequential adsorption of polycations and polyanions, while conducting polymer is characterized by a conjugated structure of alternating single and double bonds. The use of layer-by-layer in producing a membrane for separation has received considerable interest due to its properties. However, the introduction of conducting polymer as a base membrane is relatively new. Therefore, in this review, we discuss in detail three types of LBL techniques (dip, spin and spray layer-by-layer along with their parameters. We will also summarize current developments on the characterization of modified membrane prepared using the layer-by-layer techniques in terms of morphology, physical and chemical properties, and separation performances.

  7. Oily Bilgewater Separators

    Science.gov (United States)

    2011-11-01

    central core (permeate tube). Each sheet consists of oleophobic (oil repelling) outer layers and a hydrophilic (water attracting) central layer to...without clogging. Each membrane sheet has two oleophobic (oil repelling) outer surfaces and a hydrophilic (water attracting) inner layer. This...fewer alarms for the crew and minimizes potential for accidental discharge. • Cleans in place without clogging The SPIR-O-LA TOR Membranes’ oleophobic

  8. Computation of Three-Dimensional Boundary Layers Including Separation

    Science.gov (United States)

    1987-02-01

    The mixing length hypothesis consists of assuming that the mean flow imposes its time scale to the turbulent flow and we get : u . 9U 1 = 3y...turbulence is the shear 3u/3y which imposes its time scale to the energy-containing eddies. 1-6 By considering the equations for the kinetic energy of the...ormat in bo but nd th tion flow ine an H corr xcept 5 6.1 -dimen figura ng to e wall heory ion of undary t can at it of sue with

  9. Effect of catalyst distribution in the active layers of proton exchange membrane fuel cells; Effet de la distribution du catalyseur dans les couches actives de piles a combustible de type PEMFC

    Energy Technology Data Exchange (ETDEWEB)

    Bultel, Y.; Durand, R.; Ozil, P. [Ecole Nationale Superieure d' Electrochimie et d' Electrometallurgie, Lab. d' Electrochimie et de Physico-chimie des Materiaux et des Interfaces, UMR 5631, 38 - Grenoble (France); Antoine, O. [Geneva Univ., Dept. de Chimie Minerale, Analytique et Appliquee, Sciences 2 (Switzerland)

    2000-07-01

    The aim of this work is to study the influence of the distribution of the platinum catalyst in the active layers on the performances of proton exchange membrane fuel cells (PEMFC) electrodes. In the one hand, the results predicted by the classical models and those in which the active layers is modified have been compared; these results have allowed to demonstrate theoretically the effect of the discrete distribution of the platinum catalyst in the form of nano-particles. On the other hand, the influence of a distribution gradient of the platinum catalyst for porous and non-porous active layers of PEMFC cathode has been experimentally demonstrated and predicted by numerical simulations. (O.M.)

  10. [Separation anxiety in children].

    Science.gov (United States)

    Purper-Ouakil, Diane; Franc, Nathalie

    2010-06-20

    Separation anxiety disorder can be differentiated from developmental anxiety because of its intensity, persistence and negative impact on adaptive functioning. This disorder is closely linked to other anxiety and mood disorders and can also be associated with externalizing psychopathology in children and adolescents. Severe separation anxiety can result in school refusal and intra-familial violence. Cognitive behavioral therapies have the best evidence-based support for the treatment of separation anxiety disorder in children and adolescents. In addition, it is important to detect factors associated with persistence of anxiety such as systematic avoidance of separation and parental overprotection. The role of pediatricians and general practitioners in recognizing clinical separation anxiety and encouraging appropriate care and positive parental attitudes is essential, as separation anxiety is often associated with a variety of somatic symptoms.

  11. [Separation anxiety. Theoretical considerations].

    Science.gov (United States)

    Blandin, N; Parquet, P J; Bailly, D

    1994-01-01

    The interest in separation anxiety is nowadays increasing: this disorder appearing during childhood may predispose to the occurrence of anxiety disorders (such as panic disorder and agoraphobia) and major depression into adulthood. Psychoanalytic theories differ on the nature of separation anxiety and its place in child development. For some authors, separation anxiety must be understood as resulting from the unconscious internal conflicts inherent in the individuation process and gradual attainment of autonomy. From this point of view, the fear of loss of mother by separation is not regarded as resulting from a real danger. However, Freud considers the primary experience of separation from protecting mother as the prototype situation of anxiety and compares the situations generating fear to separation experiences. For him, anxiety originates from two factors: the physiological fact is initiated at the time of birth but the primary traumatic situation is the separation from mother. This point of view may be compared with behavioral theories. Behavioral theories suggest that separation anxiety may be conditioned or learned from innate fears. In Freud's theory, the primary situation of anxiety resulting from the separation from mother plays a role comparable to innate fears. Grappling with the problem of separation anxiety, Bowlby emphasizes then the importance of the child's attachment to one person (mother or primary caregiver) and the fact that this attachment is instinctive. This point of view, based on the watch of infants, is akin to ethological theories on behaviour of non human primates. Bowlby especially shows that the reactions of infant separated from mother evolve on three stages: the phase of protestation which may constitute the prototype of adulthood anxiety, the phase of desperation which may be the prototype of depression, and the phase of detachment. He emphasizes so the role of early separations in the development of vulnerability to depression

  12. 隔膜对双电层电容器和混合型电池-超级电容器的电化学性能的影响%Effects of Separator on the Electrochemical Performance of Electrical Double-Layer Capacitor and Hybrid Battery-Supercapacitor

    Institute of Scientific and Technical Information of China (English)

    孙现众; 张熊; 黄博; 马衍伟

    2014-01-01

    隔膜是双电层电容器和混合型电池-超级电容器等电化学储能器件的重要组成元件.本文采用1 mol∙L-1四乙基四氟硼酸铵的丙烯碳酸酯电解液制备了基于活性炭的扣式双电层电容器,并采用1 mol∙L-1六氟磷酸锂锂离子电解液制备了(LiNi0.5Co0.2Mn0.3O2+活性炭)/石墨体系的混合型电池-超级电容器.研究了不同类型隔膜的物理化学性能,以及其对双电层电容器和混合型电池-超级电容器的电化学性能的影响.四种隔膜分别是无纺布聚丙烯毡、多孔聚丙烯薄膜、Al2O3涂层的聚丙烯薄膜和纤维素纸隔膜.进行了表面形貌、差示扫描量热、电解液吸液量和表观接触角测试表征.电化学测试表明,采用纤维素隔膜的双电层电容器具有最高的比电容和更优的倍率性能,电容器的自放电性能差别不大.而对于混合型电池-超级电容器,采用聚丙烯薄膜和无纺布聚丙烯毡隔膜器件的比容量比其它器件约高20%,且采用纤维素隔膜的器件自放电率最高.%Separators are important components in electrochemical energy storage devices such as electrical double layer capacitors (EDLCs) and hybrid battery-supercapacitors. We prepared activated carbon-based EDLCs using an electrolyte of 1 mol∙L-1 tetraethyl ammonium tetrafluoroborate (Et4NBF4) in propylene carbonate (PC), and (LiNi0.5Co0.2Mn0.3O2+activated carbon)/graphite hybrid battery-supercapacitors using a 1 mol∙L-1 lithium hexafluorophate (LiPF6) Li-ion electrolyte. The physicochemical properties and effect of various separators on the electrochemical properties of the EDLC and hybrid battery-supercapacitor were studied. The four separators were nonwoven polypropylene (PP) mat, porous PP membrane, Al2O3-coated PP membrane, and cellulose paper. The surface morphology, differential scanning calorimetry, electrolyte uptake, and apparent contact angle were investigated. The electrochemical

  13. The separation of adult separation anxiety disorder.

    Science.gov (United States)

    Baldwin, David S; Gordon, Robert; Abelli, Marianna; Pini, Stefano

    2016-08-01

    The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) categorization of mental disorders places "separation anxiety disorder" within the broad group of anxiety disorders, and its diagnosis no longer rests on establishing an onset during childhood or adolescence. In previous editions of DSM, it was included within the disorders usually first diagnosed in infancy, childhood, or adolescence, with the requirement for an onset of symptoms before the age of 18 years: symptomatic adults could only receive a retrospective diagnosis, based on establishing this early onset. The new position of separation anxiety disorder is based upon the findings of epidemiological studies that revealed the unexpectedly high prevalence of the condition in adults, often in individuals with an onset of symptoms after the teenage years; its prominent place within the DSM-5 group of anxiety disorders should encourage further research into its epidemiology, etiology, and treatment. This review examines the clinical features and boundaries of the condition, and offers guidance on how it can be distinguished from other anxiety disorders and other mental disorders in which "separation anxiety" may be apparent.

  14. Method for producing substrates for superconducting layers

    DEFF Research Database (Denmark)

    2013-01-01

    There is provided a method for producing a substrate (600) suitable for supporting an elongated superconducting element, wherein, e.g., a deformation process is utilized in order to form disruptive strips in a layered solid element, and where etching is used to form undercut volumes (330, 332......) between an upper layer (316) and a lower layer (303) of the layered solid element. Such relatively simple steps enable providing a substrate which may be turned into a superconducting structure, such as a superconducting tape, having reduced AC losses, since the undercut volumes (330, 332) may be useful...... for separating layers of material. In a further embodiment, there is placed a superconducting layer on top of the upper layer (316) and/or lower layer (303), so as to provide a superconducting structure with reduced AC losses....

  15. Isolation, Separation, and Identification of Synthetic Food Colors.

    Science.gov (United States)

    Dixon, E. A.; Renyk, G.

    1982-01-01

    Describes a simple, inexpensive experiment for extraction of synthetic dyes permitted in foodstuffs, and their separation and identification using thin-layer chromatography and ultraviolet/visible spectroscopy. (Author/SK)

  16. Working with Separation

    Science.gov (United States)

    Krugman, Dorothy C.

    1971-01-01

    Discusses the role of the caseworker in providing support to children experiencing separation from their families and emphasizes the need to recognize that there are differences between those separation experiences dictated by the needs of children and those dictated by arbitrary or noncasework factors. (AJ)

  17. Separation anxiety disorder

    NARCIS (Netherlands)

    Nauta, M.H.; Emmelkamp, P.M.G.; Sturmey, P.; Hersen, M.

    2012-01-01

    Separation anxiety disorder (SAD) is the only anxiety disorder that is specific to childhood; however, SAD has hardly ever been addressed as a separate disorder in clinical trials investigating treatment outcome. So far, only parent training has been developed specifically for SAD. This particular t

  18. Social Separation in Monkeys.

    Science.gov (United States)

    Mineka, Susan; Suomi, Stephen J.

    1978-01-01

    Reviews phenomena associated with social separation from attachment objects in nonhuman primates. Evaluates four theoretical treatments of separation in light of existing data: Bowlby's attachment-object-loss theory, Kaufman's conservation-withdrawal theory, Seligman's learned helplessness theory, and Solomon and Corbit's opponent-process theory.…

  19. Nonterminal Separating Macro Grammars

    NARCIS (Netherlands)

    Hogendorp, Jan Anne; Asveld, P.R.J.; Nijholt, A.; Verbeek, Leo A.M.

    1987-01-01

    We extend the concept of nonterminal separating (or NTS) context-free grammar to nonterminal separating $m$-macro grammar where the mode of derivation $m$ is equal to "unrestricted". "outside-in' or "inside-out". Then we show some (partial) characterization results for these NTS $m$-macro grammars.

  20. Spiral microfluidic nanoparticle separators

    Science.gov (United States)

    Bhagat, Ali Asgar S.; Kuntaegowdanahalli, Sathyakumar S.; Dionysiou, Dionysios D.; Papautsky, Ian

    2008-02-01

    Nanoparticles have potential applications in many areas such as consumer products, health care, electronics, energy and other industries. As the use of nanoparticles in manufacturing increases, we anticipate a growing need to detect and measure particles of nanometer scale dimensions in fluids to control emissions of possible toxic nanoparticles. At present most particle separation techniques are based on membrane assisted filtering schemes. Unfortunately their efficiency is limited by the membrane pore size, making them inefficient for separating a wide range of sizes. In this paper, we propose a passive spiral microfluidic geometry for momentum-based particle separations. The proposed design is versatile and is capable of separating particulate mixtures over a wide dynamic range and we expect it will enable a variety of environmental, medical, or manufacturing applications that involve rapid separation of nanoparticles in real-world samples with a wide range of particle components.

  1. A composite chitosan-gelatin bi-layered, biomimetic macroporous scaffold for blood vessel tissue engineering.

    Science.gov (United States)

    Badhe, Ravindra V; Bijukumar, Divya; Chejara, Dharmesh R; Mabrouk, Mostafa; Choonara, Yahya E; Kumar, Pradeep; du Toit, Lisa C; Kondiah, Pierre P D; Pillay, Viness

    2017-02-10

    A composite chitosan-gelatin macroporous hydrogel-based scaffold with bi-layered tubular architecture was engineered by solvent casting-co-particulate leaching. The scaffold constituted an inner macroporous layer concealed by a non-porous outer layer mimicking the 3D matrix of blood vessels with cellular adhesion and proliferation. The scaffold was evaluated for its morphological, physicochemical, physicomechanical and biodurability properties employing SEM, FTIR, DSC, XRD, porositometry, rheology and texture analysis. The fluid uptake and biodegradation in the presence of lysozymes was also investigated. Cellular attachment and proliferation was analysed using human dermal fibroblasts (HDF-a) seeded onto the scaffold and evaluated by MTT assay, SEM, and confocal microscopy. Results demonstrated that the scaffold had a desirable tensile strength=95.81±11kPa, elongation at break 112.5±13%, porosity 82% and pores between 100 and 230μm, 50% in vitro biodegradation at day 16 and proliferated fibroblasts over 20 days. These results demonstrate that scaffold may be an excellent tubular archetype for blood vessel tissue engineering.

  2. Preparation of Monosized Hydrophilic Non-Porous Beads and Their Application in Separation of Biopolymers%无孔单分散亲水性树脂的合成及其在生物大分子分离中的应用

    Institute of Scientific and Technical Information of China (English)

    朱金霞; 龚波林

    2006-01-01

    建立了一条从分散聚合法制备种子到一步种子溶胀聚合法制备粒径5.0μm的无孔单分散亲水性交联聚甲基丙烯酸环氧丙酯树脂的新方法,对其表面用新的化学方法改性后得到一种新型的弱阳离子交换色谱填料.实验考察了流动相的流速及有机溶剂等对蛋白质保留的影响.结果表明,该填料具有良好的色谱性能,在流速为5 mL/min时4种蛋白可在3min内达到基线分离,将其应用于鸡蛋清中溶菌酶的快速分离纯化,取得了较好的效果.

  3. Method and device for the separation of particles

    NARCIS (Netherlands)

    Rem, P.C.; Van Kooy, L.A.

    2004-01-01

    The invention relates to a method of in a liquid separating a mixture of particles that within chosen limits have different physical property values, wherein the particles to be separated are supplied via a feeder to a screen upon which a layer of facilitating particles is disposed, the size of the

  4. Radiochemical separation of Cobalt

    NARCIS (Netherlands)

    Erkelens, P.C. van

    1961-01-01

    A method is described for the radiochemical separation of cobalt based on the extraordinary stability of cobalt diethyldithiocarbamate. Interferences are few; only very small amounts of zinc and iron accompany cobalt, which is important in neutron-activation analysis.

  5. On Separate Universes

    CERN Document Server

    Dai, Liang; Schmidt, Fabian

    2015-01-01

    The separate universe conjecture states that in General Relativity a density perturbation behaves locally (i.e. on scales much smaller than the wavelength of the mode) as a separate universe with different background density and curvature. We prove this conjecture for a spherical compensated tophat density perturbation of arbitrary amplitude and radius in $\\Lambda$CDM. We then use Conformal Fermi Coordinates to generalize this result to scalar perturbations of arbitrary configuration and scale in a general cosmology with a mixture of fluids, but to linear order in perturbations. In this case, the separate universe conjecture holds for the isotropic part of the perturbations. The anisotropic part on the other hand is exactly captured by a tidal field in the Newtonian form. We show that the separate universe picture is restricted to scales larger than the sound horizons of all fluid components. We then derive an expression for the locally measured matter bispectrum induced by a long-wavelength mode of arbitrary...

  6. Electroextraction separation of dyestuffs

    Energy Technology Data Exchange (ETDEWEB)

    Luo, G.S.; Yu, M.J.; Jiang, W.B.; Zhu, S.L.; Dai, Y.Y. [Tsinghua Univ., Beijing (China). Dept. of Chemical Engineering

    1999-03-01

    Electroseparation technologies have prospects for significant growth well into the next century. Electroextraction, a coupled separation technique of solvent extraction with electrophoresis, was used to remove dyestuffs from their aqueous stream. A study on the characteristics of the separation technique was carried out with n-butanol/acid-chrom blue K/water and n-butanol/methyl blue/water as working systems. A continuous separation equipment was designed and sued in this work. The influences of two-phase flow, field strength, and concentration of the feed on the recovery of solute were studied. The results showed that much higher recovery of solute with less solvent consumption could be achieved by using this technique to remove dyes from their aqueous streams, especially for the separation of the dilute solution. When the field strength is increased, the recovery and mass flux increase. When the feed flow rate and the initial solute concentration are increased, the recovery decreases and the mass flux increases.

  7. Shoulder separation - aftercare

    Science.gov (United States)

    ... and top of your shoulder blade A severe shoulder separation You may need surgery right away if you have: Numbness in your fingers Cold fingers Muscle weakness in your arm Severe deformity of the joint

  8. Radiochemical separation of Cobalt

    NARCIS (Netherlands)

    Erkelens, P.C. van

    1961-01-01

    A method is described for the radiochemical separation of cobalt based on the extraordinary stability of cobalt diethyldithiocarbamate. Interferences are few; only very small amounts of zinc and iron accompany cobalt, which is important in neutron-activation analysis.

  9. Safe Separators for Treewidth

    NARCIS (Netherlands)

    Bodlaender, H.L.; Koster, A.M.C.A.

    2003-01-01

    A set of vertices S Í V is called a safe separator for treewidth, if S is a separator of G, and the treewidth of G equals the maximum of the treewidth over all connected components W of G - S of the graph, obtained by making S a clique in the subgraph of G, induced by W È S. We show that such safe s

  10. Separation techniques: Chromatography

    OpenAIRE

    Coskun, Ozlem

    2016-01-01

    Chromatography is an important biophysical technique that enables the separation, identification, and purification of the components of a mixture for qualitative and quantitative analysis. Proteins can be purified based on characteristics such as size and shape, total charge, hydrophobic groups present on the surface, and binding capacity with the stationary phase. Four separation techniques based on molecular characteristics and interaction type use mechanisms of ion exchange, surface adsorp...

  11. Distal humeral epiphyseal separation.

    Science.gov (United States)

    Moucha, Calin S; Mason, Dan E

    2003-10-01

    Distal humeral epiphyseal separation is an uncommon injury that is often misdiagnosed upon initial presentation. To make a timely, correct diagnosis, the treating physician must have a thorough understanding of basic anatomical relationships and an awareness of the existence of this injury. This is a case of a child who sustained a separation of the distal humeral epiphysis, as well as multiple other bony injuries, secondary to child abuse.

  12. 十八烷基键合硅胶的原子层沉积法封尾及其在碱性化合物分离中的应用%Endcapping of Octadecyl Bonded Silica by Atomic Layer Deposition for Separation of Basic Compounds

    Institute of Scientific and Technical Information of China (English)

    郭志强; 陈磊; 万谦宏

    2009-01-01

    采用原子层沉积法对十八烷基键合硅胶进行端基封尾.以六甲基二硅氮烷为封端试剂,在250 ℃下与键合硅胶样品反应6 h,制备了对碱性化合物具有高惰性的反相色谱填料.分别以吡啶/苯酚和萘/阿米替林为分子探针,考察了经原子层沉积法和传统液相有机溶剂法封尾处理的十八烷基键合硅胶的色谱性能,并与商品十八烷基硅胶Zorbax SB-C_(18)和Kromasil C_(18)进行对比.结果表明,原子层沉积法封尾的十八烷基硅胶对碱性化合物的分离特性明显优于传统液相法,其色谱性能已超过Zorbax SB-C_(18),与Kromasil C_(18)相当.本方法无需有机溶剂,操作简便,反应耗时短,易于放大生产,封尾反应完全,应用前景良好.%Atomic layer deposition has been employed for postsynthesis treatment of octadecyl bonded silica (ODS) as a typical reversed-phase stationary phase for high performance liquid chromatography (HPLC) ,in an effort to alleviate peak tailing for basic compounds. With hexamethyldisilazane( HMDS) as an endcapping agent,the ODS packing materials were heated to 250℃,and maintained at that temperature for 6 h,affording packing materials which are highly inert to basic compounds. Chromatographic performance in terms of retention factor and tailing factor of the resulting phases was evaluated using phenol/pyridine and naphthalene/ami-triptyline pairs as probes. The results were compared with those for the same packing treated by liquid phase method and for the commercial products including Zorbax SB-C_(18) and Kromasil C_(18). The separation characteristics of the ODS phase obtained by atomic layer deposition appear to be superior to that by liquid phase method and,comparable with or even better than the commercial products studied. Being solvent-free process amenable to mass production,the described method provides an economical and eco-friendly approach to manufacturing HPLC packing materials on industrial scale.

  13. Response of axisymmetric separated flow to its spatially localized perturbation

    Science.gov (United States)

    Dovgal, A. V.; Zanin, B. Yu.; Sorokin, A. M.

    2016-11-01

    The flow past an axisymmetric body with laminar boundary-layer separation in a low-velocity air stream has been studied. The hot-wire technique was employed to identify the variation of velocity field induced by a local stationary perturbation of separation region at the stern of the experimental model. A large-scale influence upon the near-wall flow due to a cylinder roughness element provided on the model surface was observed. The obtained data substantiate the possibility of controlling the laminar boundary-layer separation on an axisymmetric body using a local external forcing.

  14. Wireless physical layer security

    Science.gov (United States)

    Poor, H. Vincent; Schaefer, Rafael F.

    2017-01-01

    Security in wireless networks has traditionally been considered to be an issue to be addressed separately from the physical radio transmission aspects of wireless systems. However, with the emergence of new networking architectures that are not amenable to traditional methods of secure communication such as data encryption, there has been an increase in interest in the potential of the physical properties of the radio channel itself to provide communications security. Information theory provides a natural framework for the study of this issue, and there has been considerable recent research devoted to using this framework to develop a greater understanding of the fundamental ability of the so-called physical layer to provide security in wireless networks. Moreover, this approach is also suggestive in many cases of coding techniques that can approach fundamental limits in practice and of techniques for other security tasks such as authentication. This paper provides an overview of these developments.

  15. Templated quasicrystalline molecular layers

    Science.gov (United States)

    Smerdon, Joe; Young, Kirsty; Lowe, Michael; Hars, Sanger; Yadav, Thakur; Hesp, David; Dhanak, Vinod; Tsai, An-Pang; Sharma, Hem Raj; McGrath, Ronan

    2014-03-01

    Quasicrystals are materials with long range ordering but no periodicity. We report scanning tunneling microscopy (STM) observations of quasicrystalline molecular layers on five-fold quasicrystal surfaces. The molecules adopt positions and orientations on the surface consistent with the quasicrystalline ordering of the substrate. Carbon-60 adsorbs atop sufficiently-separated Fe atoms on icosahedral Al-Cu-Fe to form a unique quasicrystalline lattice whereas further C60 molecules decorate remaining surface Fe atoms in a quasi-degenerate fashion. Pentacene (Pn) adsorbs at tenfold-symmetric points around surface-bisected rhombic triacontahedral clusters in icosahedral Ag-In-Yb. These systems constitute the first demonstrations of quasicrystalline molecular ordering on a template. EPSRC EP/D05253X/1, EP/D071828/1, UK BIS.

  16. Exploring Pore Formation of Atomic Layer-Deposited Overlayers by in Situ Small- and Wide-Angle X-ray Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Li, Tao; Karwal, Saurabh; Aoun, Bachir; Zhao, Haiyan; Ren, Yang; Canlas, Christian P.; Elam, Jeffrey W.; Winans, Randall E.

    2016-10-11

    In this work, we explore the pore structure of overcoated materials by in situ synchrotron small- and wide-angle X-ray scattering (SAXS)/(WAXS). Thin films of aluminum oxide (Al2O3) and titanium dioxide (TiO2) with thicknesses of 4.9 and 2.5 nm, respectively, are prepared by atomic layer deposition (ALD) on non-porous nanoparticles. In situ X-ray measurements reveal that porosity is induced in the ALD films by annealing the samples at high temperature. Moreover, this pore formation can be attributed to densification resulting from an amorphous to crystalline phase transition of the ALD films as confirmed by high resolution X-ray diffraction (XRD) and pair distribution function (PDF). Simultaneous SAXS/WAXS results not only show the porosity is formed by the phase transition but also that the pore size increases with temperature.

  17. Gulf stream separation dynamics

    Science.gov (United States)

    Schoonover, Joseph

    Climate models currently struggle with the more traditional, coarse ( O(100 km) ) representation of the ocean. In these coarse ocean simulations, western boundary currents are notoriously difficult to model accurately. The modeled Gulf Stream is typically seen exhibiting a mean pathway that is north of observations, and is linked to a warm sea-surface temperature bias in the Mid-Atlantic Bight. Although increased resolution ( O(10 km) ) improves the modeled Gulf Stream position, there is no clean recipe for obtaining the proper pathway. The 70 year history of literature on the Gulf Stream separation suggests that we have not reached a resolution on the dynamics that control the current's pathway just south of the Mid-Atlantic Bight. Without a concrete knowledge on the separation dynamics, we cannot provide a clean recipe for accurately modeling the Gulf Stream at increased resolutions. Further, any reliable parameterization that yields a realistic Gulf Stream path must express the proper physics of separation. The goal of this dissertation is to determine what controls the Gulf Stream separation. To do so, we examine the results of a model intercomparison study and a set of numerical regional terraforming experiments. It is argued that the separation is governed by local dynamics that are most sensitive to the steepening of the continental shelf, consistent with the topographic wave arrest hypothesis of Stern (1998). A linear extension of Stern's theory is provided, which illustrates that wave arrest is possible for a continuously stratified fluid.

  18. Separably injective Banach spaces

    CERN Document Server

    Avilés, Antonio; Castillo, Jesús M F; González, Manuel; Moreno, Yolanda

    2016-01-01

    This monograph contains a detailed exposition of the up-to-date theory of separably injective spaces: new and old results are put into perspective with concrete examples (such as l∞/c0 and C(K) spaces, where K is a finite height compact space or an F-space, ultrapowers of L∞ spaces and spaces of universal disposition). It is no exaggeration to say that the theory of separably injective Banach spaces is strikingly different from that of injective spaces. For instance, separably injective Banach spaces are not necessarily isometric to, or complemented subspaces of, spaces of continuous functions on a compact space. Moreover, in contrast to the scarcity of examples and general results concerning injective spaces, we know of many different types of separably injective spaces and there is a rich theory around them. The monograph is completed with a preparatory chapter on injective spaces, a chapter on higher cardinal versions of separable injectivity and a lively discussion of open problems and further lines o...

  19. Mass Separation by Metamaterials.

    Science.gov (United States)

    Restrepo-Flórez, Juan Manuel; Maldovan, Martin

    2016-02-25

    Being able to manipulate mass flow is critically important in a variety of physical processes in chemical and biomolecular science. For example, separation and catalytic systems, which requires precise control of mass diffusion, are crucial in the manufacturing of chemicals, crystal growth of semiconductors, waste recovery of biological solutes or chemicals, and production of artificial kidneys. Coordinate transformations and metamaterials are powerful methods to achieve precise manipulation of molecular diffusion. Here, we introduce a novel approach to obtain mass separation based on metamaterials that can sort chemical and biomolecular species by cloaking one compound while concentrating the other. A design strategy to realize such metamaterial using homogeneous isotropic materials is proposed. We present a practical case where a mixture of oxygen and nitrogen is manipulated using a metamaterial that cloaks nitrogen and concentrates oxygen. This work lays the foundation for molecular mass separation in biophysical and chemical systems through metamaterial devices.

  20. Phaco slice and separate.

    Science.gov (United States)

    Arshinoff, S A

    1999-04-01

    Phaco slice and separate retains the advantages of the chopping techniques of Nagahara, Koch, and Fukasaku but replaces chopping or snapping with slicing across the center of the phaco-tip-stabilized nucleus using a Nagahara chopper and then repositioning the chopper to optimally separate the divided lens halves. As the lens is rotated in the capsular bag, small pieces of the nuclear pie are sliced off, separated, emulsified, and aspirated. Emulsification and aspiration can alternatively be left until most or all the slices have been made. This technique works with a broader range of lens densities than other chopping techniques and uses no sculpting and very little phaco time. The phaco time required for this technique is relatively independent of nuclear density compared with a sculpting technique.

  1. Membrane separation of hydrocarbons

    Science.gov (United States)

    Chang, Y. Alice; Kulkarni, Sudhir S.; Funk, Edward W.

    1986-01-01

    Mixtures of heavy oils and light hydrocarbons may be separated by passing the mixture through a polymeric membrane. The membrane which is utilized to effect the separation comprises a polymer which is capable of maintaining its integrity in the presence of hydrocarbon compounds and which has been modified by being subjected to the action of a sulfonating agent. Sulfonating agents which may be employed will include fuming sulfuric acid, chlorosulfonic acid, sulfur trioxide, etc., the surface or bulk modified polymer will contain a degree of sulfonation ranging from about 15 to about 50%. The separation process is effected at temperatures ranging from about ambient to about 100.degree. C. and pressures ranging from about 50 to about 1000 psig.

  2. Polysulfide intercalated layered double hydroxides for metal capture applications

    Science.gov (United States)

    Kanatzidis, Mercouri G.; Ma, Shulan

    2017-04-04

    Polysulfide intercalated layered double hydroxides and methods for their use in vapor and liquid-phase metal capture applications are provided. The layered double hydroxides comprise a plurality of positively charged host layers of mixed metal hydroxides separated by interlayer spaces. Polysulfide anions are intercalated in the interlayer spaces.

  3. Polysulfide intercalated layered double hydroxides for metal capture applications

    Energy Technology Data Exchange (ETDEWEB)

    Kanatzidis, Mercouri G.; Ma, Shulan

    2017-04-04

    Polysulfide intercalated layered double hydroxides and methods for their use in vapor and liquid-phase metal capture applications are provided. The layered double hydroxides comprise a plurality of positively charged host layers of mixed metal hydroxides separated by interlayer spaces. Polysulfide anions are intercalated in the interlayer spaces.

  4. Thin layer chromatography.

    Science.gov (United States)

    Santiago, Marina; Strobel, Scott

    2013-01-01

    In many experiments, it is important to be able to separate a mixture into its chemical components in order to isolate one compound or to assess the purity of the mixture. Thin layer chromatography (TLC) is one of the easiest and most versatile methods of doing this because of its low cost, simplicity, quick development time, high sensitivity, and good reproducibility. TLC is used by many industries and fields of research, including pharmaceutical production, clinical analysis, industrial chemistry, environmental toxicology, food chemistry, water, inorganic, and pesticide analysis, dye purity, cosmetics, plant materials, and herbal analysis. In its simplest form, glass plates are coated with a uniform layer of silica gel (SiO2). The dissolved sample is placed on the plate, and the plate is inserted into a screw-top jar containing the developing solvent and a piece of filter paper. When the solvent has risen to near the top of the plate, the plate is removed, dried, and visualized using UV light. Variations on this protocol are used for different purposes, including pretreating the sample, changing the sorbent, plate material, the solvent system, the development techniques, and method of detection and visualization or by coupling TLC to other techniques. © 2013 Elsevier Inc. All rights reserved.

  5. Functionalized inorganic membranes for gas separation

    Science.gov (United States)

    Ku, Anthony Yu-Chung; Ruud, James Anthony; Molaison, Jennifer Lynn; Schick, Louis Andrew ,; Ramaswamy, Vidya

    2008-07-08

    A porous membrane for separation of carbon dioxide from a fluid stream at a temperature higher than about 200.degree. C. with selectivity higher than Knudsen diffusion selectivity. The porous membrane comprises a porous support layer comprising alumina, silica, zirconia or stabilized zirconia; a porous separation layer comprising alumina, silica, zirconia or stabilized zirconia, and a functional layer comprising a ceramic oxide contactable with the fluid stream to preferentially transport carbon dioxide. In particular, the functional layer may be MgO, CaO, SrO, BaO, La.sub.2O.sub.3, CeO.sub.2, ATiO.sub.3, AZrO.sub.3, AAl.sub.2O.sub.4, A.sup.1FeO.sub.3, A.sup.1MnO.sub.3, A.sup.1CoO.sub.3, A.sup.1NiO.sub.3, A.sup.2HfO.sub.3, A.sup.3CeO.sub.3, Li.sub.2ZrO.sub.3, Li.sub.2SiO.sub.3, Li.sub.2TiO.sub.3 or a mixture thereof; wherein A is Mg, Ca, Sr or Ba; A.sup.1 is La, Ca, Sr or Ba; A.sup.2 is Ca, Sr or Ba; and A.sup.3 is Sr or Ba.

  6. Gas separation membranes

    Science.gov (United States)

    Schell, William J.

    1979-01-01

    A dry, fabric supported, polymeric gas separation membrane, such as cellulose acetate, is prepared by casting a solution of the polymer onto a shrinkable fabric preferably formed of synthetic polymers such as polyester or polyamide filaments before washing, stretching or calendering (so called griege goods). The supported membrane is then subjected to gelling, annealing, and drying by solvent exchange. During the processing steps, both the fabric support and the membrane shrink a preselected, controlled amount which prevents curling, wrinkling or cracking of the membrane in flat form or when spirally wound into a gas separation element.

  7. Learning Isometric Separation Maps

    CERN Document Server

    Vasiloglou, Nikolaos; Anderson, David V

    2008-01-01

    Maximum Variance Unfolding (MVU) and its variants have been very successful in embedding data-manifolds in lower dimensionality spaces, often revealing the true intrinsic dimensions. In this paper we show how to also incorporate supervised class information into an MVU-like method without breaking its convexity. We call this method the Isometric Separation Map and we show that the resulting kernel matrix can be used for a binary/multiclass Support Vector Machine in a semi-supervised (transductive) framework. We also show that the method always finds a kernel matrix that linearly separates the training data exactly without projecting them in infinite dimensional spaces.

  8. Separators for electrochemical cells

    Science.gov (United States)

    Carlson, Steven Allen; Anakor, Ifenna Kingsley

    2014-11-11

    Provided are separators for use in an electrochemical cell comprising (a) an inorganic oxide and (b) an organic polymer, wherein the inorganic oxide comprises organic substituents. Preferably, the inorganic oxide comprises an hydrated aluminum oxide of the formula Al.sub.2O.sub.3.xH.sub.2O, wherein x is less than 1.0, and wherein the hydrated aluminum oxide comprises organic substituents, preferably comprising a reaction product of a multifunctional monomer and/or organic carbonate with an aluminum oxide, such as pseudo-boehmite and an aluminum oxide. Also provided are electrochemical cells comprising such separators.

  9. Separation of magnetic phases in alloys

    Energy Technology Data Exchange (ETDEWEB)

    Takacs, J. [Department of Engineering Science, University of Oxford, 5. Pound Close, Yarnton, Oxon OX5 1QG, Oxford (United Kingdom)], E-mail: jenotakacs@aol.com; Meszaros, I. [Department of Materials Science and Technology, Budapest University of Technology and Economics, Budapest (Hungary)

    2008-09-01

    In this paper we present a study of the separation of phases in multi-phase alloys. The proposed technique is based on the hyperbolic model of magnetization. By using this model it is possible to decompose the magnetic phases of alloys and determine their magnetic properties separately. Experimental verification was carried out on a transformer-like setup, constructed from layered samples representing the various magnetic phases. The samples were constructed from elements of strongly different magnetic properties. The results given by the model are in an excellent agreement with the experimental results, giving justification for the proposed method of decomposition. The proposed method is the first step towards the recognition and the separation of magnetic constituencies of different magnetic properties in an alloy by analytical means.

  10. Instrument platforms for thin-layer chromatography.

    Science.gov (United States)

    Bernard-Savary, Pierre; Poole, Colin F

    2015-11-20

    High performance column and thin-layer chromatography are both instrumental techniques but differ in that column chromatography requires a fully integrated instrument platform with high pressure capability while for thin-layer chromatography separate devices are used for each unit operation, usually at or close to atmospheric pressure, and afford higher flexibility supporting on-line or off-line operation. The unit operations of thin-layer chromatography are defined as sample application, development and evaluation with derivatization as an optional step. The diversity of equipment for each operation contributes to the flexibility of analysis by thin-layer chromatography and supports manual, semi-automated or full-automation of the separation process. Instrument platforms are more than a convenience as they affect performance, repeatability, sample detectability, and time management. The current trend in thin-layer chromatography is to make the unit operations independent of the user so that analysts can perform other tasks while each step is performed. In addition, in thin-layer chromatography it is general practice to separate several samples simultaneously, and instrument platforms are required to accommodate this feature. In this article, we review contemporary instrumentation employed in thin-layer chromatography for sample application, development, derivatization, photodocumentation, densitometric evaluation, and hyphenation with spectroscopic detectors with an emphasis on the variety and performance of commercially available systems. Some suggestions for best practices and avoidance of common mistakes are included. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. diffusive phase separation

    Directory of Open Access Journals (Sweden)

    Nobuyuki Kenmochi

    1996-01-01

    w is constrained to have double obstacles σ*≤w≤σ* (i.e., σ* and σ* are the threshold values of w. The objective of this paper is to discuss the semigroup {S(t} associated with the phase separation model, and construct its global attractor.

  12. Phase separation micro molding

    NARCIS (Netherlands)

    Vogelaar, Laura

    2005-01-01

    The research described in this thesis concerns the development of a new microfabrication method, Phase Separation Micro Molding (PSμM). While microfabrication is still best known from semiconductor industry, where it is used to integrate electrical components on a chip, the scope has immensely expan

  13. Fathering After Marital Separation

    Science.gov (United States)

    Keshet, Harry Finkelstein; Rosenthal, Kristine M.

    1978-01-01

    Deals with experiences of a group of separated or divorced fathers who chose to remain fully involved in the upbringing of their children. As they underwent transition from married parenthood to single fatherhood, these men learned that meeting demands of child care contributed to personal stability and growth. (Author)

  14. Isotope hydrograph separation

    Energy Technology Data Exchange (ETDEWEB)

    Fritz, P. [UFZ-Umweltforschungszentrum, Centre of Environmental Research Leipzig-Halle, Leipzig (Germany)

    2000-07-01

    Storm-runoff thus reflects the complex hydraulic behaviour of drainage basins and water-links of such systems. Water of different origin may participate in the events and in this lecture, the application of isotope techniques to separate storm hydrographs into different components will be presented.

  15. Unity Through Separation

    DEFF Research Database (Denmark)

    Dabelsteen, Hans B.

    This PhD thesis asks how we can conceptualize the current separation doctrine of religion and politics in a country like Denmark, where the structure of the established church and peoplehood overlap. In order to answer this question, Hans Bruun Dabelsteen maps the current discussion of secularism...

  16. Acromioclavicular Joint Separations

    Science.gov (United States)

    2013-01-01

    Published online: 16 December 2012 # Springer Science+Business Media New York 2012 Abstract Acromioclavicular (AC) joint separations are common...injuries. The sports most likely to cause AC joint dislocations are football, soccer , hockey, rugby, and skiing, among others [9, 28, 29]. The major cause

  17. Pre-Separation Guide

    Science.gov (United States)

    1992-03-04

    SEPARATEES Defense Outplacement Referral System (DORS) Since most of us are not independently wealthy, we will need a job after separation. DORS is...Job Assistance SPOUSES OF ALL SEPARATEES As a spouse you may take advantage of preparing Standard Form 17 1’s and resu- the outplacement services

  18. Separation of Powers.

    Science.gov (United States)

    Bill of Rights in Action, 1987

    1987-01-01

    The dimensions of the separation of powers principle are explored through three lessons in the subject areas of U.S. history, U.S. government, and world history. In 1748, a French nobleman, Baron de Montesquieu, wrote a book called "The Spirit of the Laws," in which he argued that there could be no liberty when all government power was…

  19. AutoCAD discipline layering convention. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, B.L.

    1995-05-17

    This document is a user`s guide to establishing layering standards for drawing development. Uniform layering standards are established to exchange of AutoCAD datasets between organizations and companies. Consistency in the layering conventions assists the user through logical separation and identification of drawing data. This allows the user to view and plot related aspects of a drawing separately or in combination. The use of color and Linetype by layer is the preferred layering convention method, however to accommodate specific needs, colors and linetypes can also be assigned on an entity basis. New drawing setup files (also identified in AutoCAD documentation as Prototype drawings) use this layering convention to establish discipline drawing layers that are routinely used. Additions, deletions or revisions to the layering conventions are encourage.

  20. Microgravity Passive Phase Separator

    Science.gov (United States)

    Paragano, Matthew; Indoe, William; Darmetko, Jeffrey

    2012-01-01

    A new invention disclosure discusses a structure and process for separating gas from liquids in microgravity. The Microgravity Passive Phase Separator consists of two concentric, pleated, woven stainless- steel screens (25-micrometer nominal pore) with an axial inlet, and an annular outlet between both screens (see figure). Water enters at one end of the center screen at high velocity, eventually passing through the inner screen and out through the annular exit. As gas is introduced into the flow stream, the drag force exerted on the bubble pushes it downstream until flow stagnation or until it reaches an equilibrium point between the surface tension holding bubble to the screen and the drag force. Gas bubbles of a given size will form a front that is moved further down the length of the inner screen with increasing velocity. As more bubbles are added, the front location will remain fixed, but additional bubbles will move to the end of the unit, eventually coming to rest in the large cavity between the unit housing and the outer screen (storage area). Owing to the small size of the pores and the hydrophilic nature of the screen material, gas does not pass through the screen and is retained within the unit for emptying during ground processing. If debris is picked up on the screen, the area closest to the inlet will become clogged, so high-velocity flow will persist farther down the length of the center screen, pushing the bubble front further from the inlet of the inner screen. It is desired to keep the velocity high enough so that, for any bubble size, an area of clean screen exists between the bubbles and the debris. The primary benefits of this innovation are the lack of any need for additional power, strip gas, or location for venting the separated gas. As the unit contains no membrane, the transport fluid will not be lost due to evaporation in the process of gas separation. Separation is performed with relatively low pressure drop based on the large surface

  1. Shock Wave Induced Separation Control by Streamwise Vortices

    Institute of Scientific and Technical Information of China (English)

    Ryszard SZWABA

    2005-01-01

    Control of shock wave and boundary layer interaction finds still a lot of attention. Methods of this interaction control have been especially investigated in recent decade. This research was mostly concerned with flows without separation. However, in many applications shock waves induce separation often leads to strong unsteady effects. In this context it is proposed to use streamwise vortices for the interaction control. The results of experimental investigations are presented here. The very promising results were obtained, meaning that the incipient separation was postponed and the separation size was reduced for the higher Mach numbers. The decrease of the RMS of average shock wave oscillation was also achieved.

  2. GPS Separator HD

    CERN Multimedia

    2016-01-01

    Footage of the 70 degree ISOLDE GPS separator magnet MAG70 as well as the switchyard for the Central Mass and GLM (GPS Low Mass) and GHM (GPS High Mass) beamlines in the GPS separator zone. In the GPS20 vacuum sector equipment such as the long GPS scanner 482 / 483 unit, faraday cup FC 490, vacuum valves and wiregrid piston WG210 and WG475 and radiation monitors can also be seen. Also the RILIS laser guidance and trajectory can be seen, the GPS main beamgate switch box and the actual GLM, GHM and Central Beamline beamgates in the beamlines as well as the first electrostatic quadrupoles for the GPS lines. Close up of the GHM deflector plates motor and connections and the inspection glass at the GHM side of the switchyard.

  3. HRS Separator HD

    CERN Multimedia

    2016-01-01

    Footage of the 90 and 60 degree ISOLDE HRS separator magnets in the HRS separator zone. In the two vacuum sectors HRS20 and HRS30 equipment such as the HRS slits SL240, the HRS faraday cup FC300 and wiregrid WG210 can be spotted. Vacuum valves, turbo pumps, beamlines, quadrupoles, water and compressed air connections, DC and signal cabling can be seen throughout the video. The HRS main and user beamgate in the beamline between MAG90 and MAG60 and its switchboxes as well as all vacuum bellows and flanges are shown. Instrumentation such as the HRS scanner unit 482 / 483, the HRS WG470 wiregrid and slits piston can be seen. The different quadrupoles and supports are shown as well as the RILIS guidance tubes and installation at the magnets and the different radiation monitors.

  4. Nylon separators. [thermal degradation

    Science.gov (United States)

    Lim, H. S.

    1977-01-01

    A nylon separator was placed in a flooded condition in K0H solution and heated at various high temperatures ranging from 60 C to 110 C. The weight decrease was measured and the molecular weight and decomposition product were analyzed to determine: (1) the effect of K0H concentration on the hydrolysis rate; (2) the effect of K0H concentration on nylon degradation; (3) the activation energy at different K0H concentrations; and (4) the effect of oxygen on nylon degradation. The nylon hydrolysis rate is shown to increase as K0H concentration is decreased 34%, giving a maximum rate at about 16%. Separator hydrolysis is confirmed by molecular weight decrease in age of the batteries, and the reaction of nylon with molecular oxygen is probably negligible, compared to hydrolysis. The extrapolated rate value from the high temperature experiment correlates well with experimental values at 35 degrees.

  5. Battery separator manufacturing process

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, N.I.; Sugarman, N.

    1974-12-27

    A battery with a positive plate, a negative plate, and a separator of polymeric resin having a degree of undesirable hydrophobia, solid below 180/sup 0/F, extrudable as a hot melt, and resistant to degradation by at least either acids or alkalies positioned between the plates is described. The separator comprises a nonwoven mat of fibers, the fibers being comprised of the polymeric resin and a wetting agent in an amount of 0.5 to 20 percent by weight based on the weight of the resin with the amount being incompatible with the resin below the melting point of the resin such that the wetting agent will bloom over a period of time at ambient temperatures in a battery, yet being compatible with the resin at the extrusion temperature and bringing about blooming to the surface of the fibers when the fibers are subjected to heat and pressure.

  6. Unity Through Separation

    DEFF Research Database (Denmark)

    Dabelsteen, Hans B.

    analysis, Dabelsteen study Danish secularism as an ideological concept. He finds that the conceptual structure of Danish secularism holds separation-as-principled distance at its core. Institutionally this particularly pertains to the establishment arrangement, and in practice it translates...... and proposes two conceptual expansions. The first is to include modest establishment in a framework of secularism defensible by political liberalism, and the second is to consider secularism in close connection to a theory of peoplehood. Methodologically positioned between interpretive realism and policy...... into the principle of treating everybody equally (with religious freedom, equality and Danish peoplehood as the most important principles adjacent to secularism). In a study of the historical roots of the separation doctrine and two current policy cases (same-sex marriage and reforms of church governance...

  7. Acoustophoresis separation method

    Science.gov (United States)

    Heyman, Joseph S. (Inventor)

    1993-01-01

    A method and apparatus are provided for acoustophoresis, i.e., the separation of species via acoustic waves. An ultrasonic transducer applies an acoustic wave to one end of a sample container containing at least two species having different acoustic absorptions. The wave has a frequency tuned to or harmonized with the point of resonance of the species to be separated. This wave causes the species to be driven to an opposite end of the sample container for removal. A second ultrasonic transducer may be provided to apply a second, oppositely directed acoustic wave to prevent undesired streaming. In addition, a radio frequency tuned to the mechanical resonance and coupled with a magnetic field can serve to identify a species in a medium comprising species with similar absorption coefficients, whereby an acoustic wave having a frequency corresponding to this gyrational rate can then be applied to sweep the identified species to one end of the container for removal.

  8. Separation of enantiomers

    CERN Document Server

    Todd , Matthew H

    2014-01-01

    In one handy volume this handbook summarizes the most common synthetic methods for the separation of racemic mixtures, allowing an easy comparison of the different strategies described in the literature.Alongside classical methods, the authors also consider kinetic resolutions, dynamic kinetic resolutions, divergent reactions of a racemic mixture, and a number of ""neglected"" cases not covered elsewhere, such as the use of circularly polarized light, polymerizations, ""ripening"" processes, dynamic combinatorial chemistry, and several thermodynamic processes. The result is a thorough introdu

  9. Separation Logic and Concurrency

    Science.gov (United States)

    Bornat, Richard

    Concurrent separation logic is a development of Hoare logic adapted to deal with pointers and concurrency. Since its inception, it has been enhanced with a treatment of permissions to enable sharing of data between threads, and a treatment of variables as resource alongside heap cells as resource. An introduction to the logic is given with several examples of proofs, culminating in a treatment of Simpson's 4-slot algorithm, an instance of racy non-blocking concurrency.

  10. Joint Scheme for Physical Layer Error Correction and Security

    OpenAIRE

    Oluwayomi Adamo; Varanasi, M. R.

    2011-01-01

    We present a joint scheme that combines both error correction and security at the physical layer. In conventional communication systems, error correction is carried out at the physical layer while data security is performed at an upper layer. As a result, these steps are done as separate steps. However there has been a lot of interest in providing security at the physical layer. As a result, as opposed to the conventional system, we present a scheme that combines error correction and data sec...

  11. Innovative Separations Technologies

    Energy Technology Data Exchange (ETDEWEB)

    J. Tripp; N. Soelberg; R. Wigeland

    2011-05-01

    Reprocessing used nuclear fuel (UNF) is a multi-faceted problem involving chemistry, material properties, and engineering. Technology options are available to meet a variety of processing goals. A decision about which reprocessing method is best depends significantly on the process attributes considered to be a priority. New methods of reprocessing that could provide advantages over the aqueous Plutonium Uranium Reduction Extraction (PUREX) and Uranium Extraction + (UREX+) processes, electrochemical, and other approaches are under investigation in the Fuel Cycle Research and Development (FCR&D) Separations Campaign. In an attempt to develop a revolutionary approach to UNF recycle that may have more favorable characteristics than existing technologies, five innovative separations projects have been initiated. These include: (1) Nitrogen Trifluoride for UNF Processing; (2) Reactive Fluoride Gas (SF6) for UNF Processing; (3) Dry Head-end Nitration Processing; (4) Chlorination Processing of UNF; and (5) Enhanced Oxidation/Chlorination Processing of UNF. This report provides a description of the proposed processes, explores how they fit into the Modified Open Cycle (MOC) and Full Recycle (FR) fuel cycles, and identifies performance differences when compared to 'reference' advanced aqueous and fluoride volatility separations cases. To be able to highlight the key changes to the reference case, general background on advanced aqueous solvent extraction, advanced oxidative processes (e.g., volumetric oxidation, or 'voloxidation,' which is high temperature reaction of oxide UNF with oxygen, or modified using other oxidizing and reducing gases), and fluorination and chlorination processes is provided.

  12. Colour Separation and Aversion

    Directory of Open Access Journals (Sweden)

    Sarah M Haigh

    2012-05-01

    Full Text Available Aversion to achromatic patterns is well documented but relatively little is known about discomfort from chromatic patterns. Large colour differences are uncommon in the natural environment and deviation from natural statistics makes images uncomfortable (Fernandez and Wilkins 2008, Perception, 37(7, 1098–113; Juricevic et al 2010, Perception, 39(7, 884–899. We report twelve studies documenting a linear increase in aversion to chromatic square-wave gratings as a function of the separation in UCS chromaticity between the component bars, independent of their luminance contrast. Two possible explanations for the aversion were investigated: (1 accommodative response, or (2 cortical metabolic demand. We found no correlation between chromaticity separation and accommodative lag or variance in lag, measured using an open-field autorefractor. However, near infrared spectroscopy of the occipital cortex revealed a larger oxyhaemoglobin response to patterns with large chromaticity separation. The aversion may be cortical in origin and does not appear to be due to accommodation.

  13. Growing Multiplex Networks with Arbitrary Number of Layers

    CERN Document Server

    Fotouhi, Babak

    2015-01-01

    This paper focuses on the problem of growing multiplex networks. Currently, the results on the inter-layer degree distribution of growing multiplex networks present in the literature pertain to the case of two layers, and are confined to the special case of homogeneous growth. In the present paper, we obtain closed-form solutions for the inter-layer degree distribution of heterogeneously growing multilayer networks with arbitrary number of layers in the steady state. Heterogeneous growth means that each incoming node establishes different numbers of links in different layers. We first briefly consider the problem for two layers: we consider the cases of preferential attachment and uniform attachment separately, and we obtain closed-form expressions for the inter-layer degree distribution and expected degree distributions in each layer. Then for both attachment schemes, we generalize the problem to $M$ layers, and provide solutions for the joint degree distribution across all layers.

  14. Impactfactors and optimization method on the separation of active components in licorice by micellar thin layer chromatography%胶束薄层色谱分离甘草活性成分的影响因素及优化方法

    Institute of Scientific and Technical Information of China (English)

    崔淑芬; 林焕冰; 王小如

    2012-01-01

    目的:为甘草的胶束薄层色谱指纹图谱寻找最优胶束流动相.方法:首先采用单因子法,寻找影响甘草胶束薄层色谱的影响因素,在此基础上,采用控制加权可变步长单纯形优化法进行甘草胶束薄层色谱指纹图谱的流动相优化.结果:对甘草的胶束薄层色谱分离条件(表面活性剂的种类和含量、醇和酸改性剂的影响等)进行了实验,表明纯胶束薄层色谱的柱效较低,加入醇和酸类改性剂后柱效有明显提高.通过对改性胶束的进一步优化(控制加权可变步长单纯形优化法),得到优化的甘草改性胶束展开剂组成为:0.23 mol·L-1的SDS+ 16%(v/v)正丁醇+11%(v/v)甲酸.本研究对胶束薄层色谱的一些分离机理亦进行了探讨.结论:胶束薄层色谱的表面活性剂和各添加剂间存在交互作用,需采用合适的优化方法,才能达到分离中药材复杂活性成分群的目的.%Objective: To seek the best mobile phase of micellar thin - layer chromatography ( MTLC) of licorice fingerprint. Method: Single impact factor of mobile phase in licorice MTLC fingerprint was tested individually and controlled weighted centroid simplex method was used finally to optimize the mobile phase of licorice MTLC fingerprint. Results: The selectivity of micellar TLC was studied for the separation of active components in licorice under various operation variables including concentrations of surfactant and co - surfactant, surfactant type, addition of acid modifier,et al. The results show that the low chromatography efficiency of micellar TLC could be improved by the addition of alcohol and acid modifier. Using controlled weighted centroid simplex method,optimization micellar TLC developing system of licorice was achieved which consists of 0. 23 mol · L-1 SDS,16% (v/v)n -butanol and 11% (v/v)methyl acid. In addition,the separation mechanism of micellar TLC was also discussed. Conclusion: he appropriate optimization method should

  15. Innovation in Layer-by-Layer Assembly.

    Science.gov (United States)

    Richardson, Joseph J; Cui, Jiwei; Björnmalm, Mattias; Braunger, Julia A; Ejima, Hirotaka; Caruso, Frank

    2016-12-14

    Methods for depositing thin films are important in generating functional materials for diverse applications in a wide variety of fields. Over the last half-century, the layer-by-layer assembly of nanoscale films has received intense and growing interest. This has been fueled by innovation in the available materials and assembly technologies, as well as the film-characterization techniques. In this Review, we explore, discuss, and detail innovation in layer-by-layer assembly in terms of past and present developments, and we highlight how these might guide future advances. A particular focus is on conventional and early developments that have only recently regained interest in the layer-by-layer assembly field. We then review unconventional assemblies and approaches that have been gaining popularity, which include inorganic/organic hybrid materials, cells and tissues, and the use of stereocomplexation, patterning, and dip-pen lithography, to name a few. A relatively recent development is the use of layer-by-layer assembly materials and techniques to assemble films in a single continuous step. We name this "quasi"-layer-by-layer assembly and discuss the impacts and innovations surrounding this approach. Finally, the application of characterization methods to monitor and evaluate layer-by-layer assembly is discussed, as innovation in this area is often overlooked but is essential for development of the field. While we intend for this Review to be easily accessible and act as a guide to researchers new to layer-by-layer assembly, we also believe it will provide insight to current researchers in the field and help guide future developments and innovation.

  16. Method of transferring a thin crystalline semiconductor layer

    Science.gov (United States)

    Nastasi, Michael A.; Shao, Lin; Theodore, N. David

    2006-12-26

    A method for transferring a thin semiconductor layer from one substrate to another substrate involves depositing a thin epitaxial monocrystalline semiconductor layer on a substrate having surface contaminants. An interface that includes the contaminants is formed in between the deposited layer and the substrate. Hydrogen atoms are introduced into the structure and allowed to diffuse to the interface. Afterward, the thin semiconductor layer is bonded to a second substrate and the thin layer is separated away at the interface, which results in transferring the thin epitaxial semiconductor layer from one substrate to the other substrate.

  17. Eddy current separation apparatus, separation module, separation method and method for adjusting an eddy current separation apparatus

    NARCIS (Netherlands)

    Rem, P.C.; Bakker, M.C.M.; Berkhout, S.P.M.; Rahman, M.A.

    2012-01-01

    Eddy current separation apparatus (1) for separating particles (20) from a particle stream (w), wherein the apparatus (1) comprises a separator drum (4) adapted to create a first particle fraction (21) and a second particle fraction (23), a feeding device (2) upstream of the separator drum (4) for s

  18. SEPARATION OF PLUTONIUM

    Science.gov (United States)

    Maddock, A.G.; Smith, F.

    1959-08-25

    A method is described for separating plutonium from uranium and fission products by treating a nitrate solution of fission products, uranium, and hexavalent plutonium with a relatively water-insoluble fluoride to adsorb fission products on the fluoride, treating the residual solution with a reducing agent for plutonium to reduce its valence to four and less, treating the reduced plutonium solution with a relatively insoluble fluoride to adsorb the plutonium on the fluoride, removing the solution, and subsequently treating the fluoride with its adsorbed plutonium with a concentrated aqueous solution of at least one of a group consisting of aluminum nitrate, ferric nitrate, and manganous nitrate to remove the plutonium from the fluoride.

  19. POLONIUM SEPARATION PROCESS

    Science.gov (United States)

    Karraker, D.G.

    1959-07-14

    A liquid-liquid extraction process is presented for the recovery of polonium from lead and bismuth. According to the invention an acidic aqueous chloride phase containing the polonium, lead, and bismuth values is contacted with a tributyl phosphate ether phase. The polonium preferentially enters the organic phase which is then separated and washed with an aqueous hydrochloric solution to remove any lead or bismuth which may also have been extracted. The now highly purified polonium in the organic phase may be transferred to an aqueous solution by extraction with aqueous nitric acid.

  20. PLUTONIUM SEPARATION METHOD

    Science.gov (United States)

    Beaufait, L.J. Jr.; Stevenson, F.R.; Rollefson, G.K.

    1958-11-18

    The recovery of plutonium ions from neutron irradiated uranium can be accomplished by bufferlng an aqueous solutlon of the irradiated materials containing tetravalent plutonium to a pH of 4 to 7, adding sufficient acetate to the solution to complex the uranyl present, adding ferric nitrate to form a colloid of ferric hydroxide, plutonlum, and associated fission products, removing and dissolving the colloid in aqueous nitric acid, oxldizlng the plutonium to the hexavalent state by adding permanganate or dichromate, treating the resultant solution with ferric nitrate to form a colloid of ferric hydroxide and associated fission products, and separating the colloid from the plutonlum left in solution.

  1. A Classroom Demonstration of Water-Induced Phase Separation of Alcohol-Gasoline Biofuel Blends

    Science.gov (United States)

    Mueller, Sherry A.; Anderson, James E.; Wallington, Timothy J.

    2009-01-01

    A significant issue associated with ethanol-gasoline blends is the phase separation that occurs with the addition of small volumes of water, producing an ethanol-deficient gasoline layer and an ethanol-rich aqueous layer. The gasoline layer may have a lower-than-desired octane rating due to the decrease in ethanol content, resulting in engine…

  2. A Classroom Demonstration of Water-Induced Phase Separation of Alcohol-Gasoline Biofuel Blends

    Science.gov (United States)

    Mueller, Sherry A.; Anderson, James E.; Wallington, Timothy J.

    2009-01-01

    A significant issue associated with ethanol-gasoline blends is the phase separation that occurs with the addition of small volumes of water, producing an ethanol-deficient gasoline layer and an ethanol-rich aqueous layer. The gasoline layer may have a lower-than-desired octane rating due to the decrease in ethanol content, resulting in engine…

  3. Printed Spacecraft Separation System

    Energy Technology Data Exchange (ETDEWEB)

    Holmans, Walter [Planetary Systems Corporation, Silver Springs, MD (United States); Dehoff, Ryan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-10-01

    In this project Planetary Systems Corporation proposed utilizing additive manufacturing (3D printing) to manufacture a titanium spacecraft separation system for commercial and US government customers to realize a 90% reduction in the cost and energy. These savings were demonstrated via “printing-in” many of the parts and sub-assemblies into one part, thus greatly reducing the labor associated with design, procurement, assembly and calibration of mechanisms. Planetary Systems Corporation redesigned several of the components of the separation system based on additive manufacturing principles including geometric flexibility and the ability to fabricate complex designs, ability to combine multiple parts of an assembly into a single component, and the ability to optimize design for specific mechanical property targets. Shock absorption was specifically targeted and requirements were established to attenuate damage to the Lightband system from shock of initiation. Planetary Systems Corporation redesigned components based on these requirements and sent the designs to Oak Ridge National Laboratory to be printed. ORNL printed the parts using the Arcam electron beam melting technology based on the desire for the parts to be fabricated from Ti-6Al-4V based on the weight and mechanical performance of the material. A second set of components was fabricated from stainless steel material on the Renishaw laser powder bed technology due to the improved geometric accuracy, surface finish, and wear resistance of the material. Planetary Systems Corporation evaluated these components and determined that 3D printing is potentially a viable method for achieving significant cost and savings metrics.

  4. Virus separation using membranes.

    Science.gov (United States)

    Grein, Tanja A; Michalsky, Ronald; Czermak, Peter

    2014-01-01

    Industrial manufacturing of cell culture-derived viruses or virus-like particles for gene therapy or vaccine production are complex multistep processes. In addition to the bioreactor, such processes require a multitude of downstream unit operations for product separation, concentration, or purification. Similarly, before a biopharmaceutical product can enter the market, removal or inactivation of potential viral contamination has to be demonstrated. Given the complexity of biological solutions and the high standards on composition and purity of biopharmaceuticals, downstream processing is the bottleneck in many biotechnological production trains. Membrane-based filtration can be an economically attractive and efficient technology for virus separation. Viral clearance, for instance, of up to seven orders of magnitude has been reported for state of the art polymeric membranes under best conditions.This chapter summarizes the fundamentals of virus ultrafiltration, diafiltration, or purification with adsorptive membranes. In lieu of an impractical universally applicable protocol for virus filtration, application of these principles is demonstrated with two examples. The chapter provides detailed methods for production, concentration, purification, and removal of a rod-shaped baculovirus (Autographa californica M nucleopolyhedrovirus, about 40 × 300 nm in size, a potential vector for gene therapy, and an industrially important protein expression system) or a spherical parvovirus (minute virus of mice, 22-26 nm in size, a model virus for virus clearance validation studies).

  5. Laser-induced phase separation of silicon carbide

    Science.gov (United States)

    Choi, Insung; Jeong, Hu Young; Shin, Hyeyoung; Kang, Gyeongwon; Byun, Myunghwan; Kim, Hyungjun; Chitu, Adrian M.; Im, James S.; Ruoff, Rodney S.; Choi, Sung-Yool; Lee, Keon Jae

    2016-11-01

    Understanding the phase separation mechanism of solid-state binary compounds induced by laser-material interaction is a challenge because of the complexity of the compound materials and short processing times. Here we present xenon chloride excimer laser-induced melt-mediated phase separation and surface reconstruction of single-crystal silicon carbide and study this process by high-resolution transmission electron microscopy and a time-resolved reflectance method. A single-pulse laser irradiation triggers melting of the silicon carbide surface, resulting in a phase separation into a disordered carbon layer with partially graphitic domains (~2.5 nm) and polycrystalline silicon (~5 nm). Additional pulse irradiations cause sublimation of only the separated silicon element and subsequent transformation of the disordered carbon layer into multilayer graphene. The results demonstrate viability of synthesizing ultra-thin nanomaterials by the decomposition of a binary system.

  6. Sound field separation with sound pressure and particle velocity measurements

    DEFF Research Database (Denmark)

    Fernandez Grande, Efren; Jacobsen, Finn; Leclère, Quentin

    2012-01-01

    separation techniques make it possible to distinguish between outgoing and incoming waves from the two sides, and thus NAH can be applied. In this paper, a separation method based on the measurement of the particle velocity in two layers and another method based on the measurement of the pressure...... and the velocity in a single layer are proposed. The two methods use an equivalent source formulation with separate transfer matrices for the outgoing and incoming waves, so that the sound from the two sides of the array can be modeled independently. A weighting scheme is proposed to account for the distance...... pressure-velocity method, although it requires an additional measurement surface. On the whole, the separation methods can be useful when the disturbance of the incoming field is significant. Otherwise the direct reconstruction is more accurate and straightforward. © 2012 Acoustical Society of America....

  7. Two-Dimensional Turbulent Separated Flow. Volume 1

    Science.gov (United States)

    1985-06-01

    of detached turbulent boundary layers, even when the sign of U is changed to account for mean backflows. Thus, earlier researchers, such as Kuhn and...Turbulent Shear Layer," Third Symposium on Turbulent Shear Flows, pp. 16.23-16.29. Hillier, R., Latour , M.E.M.P., and Cherry, N.J. (1983), "Unsteady...344. Kuhn , G.D. and Nielsen, J.N. (1971), "An Analytical Method for Calculating Turbulent Separated Flows Due to Adverse Pressure Gradients

  8. Plasma separation: physical separation at the molecular level

    Science.gov (United States)

    Gueroult, Renaud; Rax, Jean-Marcel; Fisch, Nathaniel J.

    2016-09-01

    Separation techniques are usually divided in two categories depending on the nature of the discriminating property: chemical or physical. Further to this difference, physical and chemical techniques differ in that chemical separation typically occurs at the molecular level, while physical separation techniques commonly operate at the macroscopic scale. Separation based on physical properties can in principle be realized at the molecular or even atomic scale by ionizing the mixture. This is in essence plasma based separation. Due to this fundamental difference, plasma based separation stands out from other separation techniques, and features unique properties. In particular, plasma separation allows separating different elements or chemical compounds based on physical properties. This could prove extremely valuable to separate macroscopically homogeneous mixtures made of substances of similar chemical formulation. Yet, the realization of plasma separation techniques' full potential requires identifying and controlling basic mechanisms in complex plasmas which exhibit suitable separation properties. In this paper, we uncover the potential of plasma separation for various applications, and identify the key physics mechanisms upon which hinges the development of these techniques.

  9. Membranes for separation of carbon dioxide

    Science.gov (United States)

    Ku, Anthony Yu-Chung; Ruud, James Anthony; Ramaswamy, Vidya; Willson, Patrick Daniel; Gao, Yan

    2011-03-01

    Methods for separating carbon dioxide from a fluid stream at a temperature higher than about 200.degree. C. with selectivity higher than Knudsen diffusion selectivity include contacting a porous membrane with the fluid stream to preferentially transport carbon dioxide. The porous membrane includes a porous support and a continuous porous separation layer disposed on a surface of the porous support and extending between the fluid stream and the porous support layer. The porous support comprises alumina, silica, zirconia, stabilized zirconia, stainless steel, titanium, nickel-based alloys, aluminum-based alloys, zirconium-based alloys or a combination thereof. Median pore size of the porous separation layer is less than about 10 nm, and the porous separation layer comprises titania, MgO, CaO, SrO, BaO, La.sub.2O.sub.3, CeO.sub.2, HfO.sub.2, Y.sub.2O.sub.3, VO.sub.z, NbO.sub.z, TaO.sub.z, ATiO.sub.3, AZrO.sub.3, AAl.sub.2O.sub.4, A.sup.1FeO.sub.3, A.sup.1MnO.sub.3, A.sup.1CoO.sub.3, A.sup.1NiO.sub.3, A.sup.2HfO.sub.3, A.sup.3 CeO.sub.3, Li.sub.2ZrO.sub.3, Li.sub.2SiO.sub.3, Li.sub.2TiO.sub.3, Li.sub.2HfO.sub.3, A.sup.4N.sup.1.sub.yO.sub.z, Y.sub.xN.sup.1.sub.yO.sub.z, La.sub.xN.sup.1.sub.yO.sub.z, HfN.sup.2.sub.yO.sub.z, or a combination thereof; wherein A is La, Mg, Ca, Sr or Ba; A.sup.1 is La, Ca, Sr or Ba; A.sup.2 is Ca, Sr or Ba; A.sup.3 is Sr or Ba; A.sup.4 is Mg, Ca, Sr, Ba, Ti or Zr; N.sup.1 is V, Nb, Ta, Cr, Mo, W, Mn, Si or Ge; N.sup.2 is V, Mo, W or Si; x is 1 or 2; y ranges from 1 to 3; and z ranges from 2 to 7.

  10. Particle separator scroll vanes

    Energy Technology Data Exchange (ETDEWEB)

    Lastrina, F. A.; Mayer, J. C.; Pommer, L. M.

    1985-07-09

    An inlet particle separator for a gas turbine engine is provided with unique vanes distributed around an entrance to a particle collection chamber. The vanes are uniquely constructed to direct extraneous particles that enter the engine into the collection chamber and prevent the particles from rebounding back into the engine's air flow stream. The vanes are provided with several features to accomplish this function, including upstream faces that are sharply angled towards air flow stream direction to cause particles to bounce towards the collection chamber. In addition, throat regions between the vanes cause a localized air flow acceleration and a focusing of the particles that aid in directing the particles in a proper direction.

  11. Nebulized therapy. SEPAR year.

    Science.gov (United States)

    Olveira, Casilda; Muñoz, Ana; Domenech, Adolfo

    2014-12-01

    Inhaled drugs are deposited directly in the respiratory tract. They therefore achieve higher concentrations with faster onset of action and fewer side effects than when used systemically. Nebulized drugs are mainly recommended for patients that require high doses of bronchodilators, when they need to inhale drugs that only exist in this form (antibiotics or dornase alfa) or when they are unable to use other inhalation devices. Technological development in recent years has led to new devices that optimize pulmonary deposits and reduce the time needed for treatment. In this review we focus solely on drugs currently used, or under investigation, for nebulization in adult patients; basically bronchodilators, inhaled steroids, antibiotics, antifungals, mucolytics and others such as anticoagulants, prostanoids and lidocaine. Copyright © 2014 SEPAR. Published by Elsevier Espana. All rights reserved.

  12. Block copolymer battery separator

    Energy Technology Data Exchange (ETDEWEB)

    Wong, David; Balsara, Nitash Pervez

    2016-04-26

    The invention herein described is the use of a block copolymer/homopolymer blend for creating nanoporous materials for transport applications. Specifically, this is demonstrated by using the block copolymer poly(styrene-block-ethylene-block-styrene) (SES) and blending it with homopolymer polystyrene (PS). After blending the polymers, a film is cast, and the film is submerged in tetrahydrofuran, which removes the PS. This creates a nanoporous polymer film, whereby the holes are lined with PS. Control of morphology of the system is achieved by manipulating the amount of PS added and the relative size of the PS added. The porous nature of these films was demonstrated by measuring the ionic conductivity in a traditional battery electrolyte, 1M LiPF.sub.6 in EC/DEC (1:1 v/v) using AC impedance spectroscopy and comparing these results to commercially available battery separators.

  13. Block copolymer battery separator

    Science.gov (United States)

    Wong, David; Balsara, Nitash Pervez

    2016-04-26

    The invention herein described is the use of a block copolymer/homopolymer blend for creating nanoporous materials for transport applications. Specifically, this is demonstrated by using the block copolymer poly(styrene-block-ethylene-block-styrene) (SES) and blending it with homopolymer polystyrene (PS). After blending the polymers, a film is cast, and the film is submerged in tetrahydrofuran, which removes the PS. This creates a nanoporous polymer film, whereby the holes are lined with PS. Control of morphology of the system is achieved by manipulating the amount of PS added and the relative size of the PS added. The porous nature of these films was demonstrated by measuring the ionic conductivity in a traditional battery electrolyte, 1M LiPF.sub.6 in EC/DEC (1:1 v/v) using AC impedance spectroscopy and comparing these results to commercially available battery separators.

  14. Gravity separation for oil wastewater treatment

    OpenAIRE

    Golomeova, Mirjana; Zendelska, Afrodita; Krstev, Boris; Krstev, Aleksandar

    2010-01-01

    In this paper, the applications of gravity separation for oil wastewater treatment are presented. Described is operation on conventional gravity separation and parallel plate separation. Key words: gravity separation, oil, conventional gravity separation, parallel plate separation.

  15. Gravity separation for oil wastewater treatment

    OpenAIRE

    Golomeova, Mirjana; Zendelska, Afrodita; Krstev, Boris; Krstev, Aleksandar

    2010-01-01

    In this paper, the applications of gravity separation for oil wastewater treatment are presented. Described is operation on conventional gravity separation and parallel plate separation. Key words: gravity separation, oil, conventional gravity separation, parallel plate separation.

  16. Atomic Layer Deposition of Chemical Passivation Layers and High Performance Anti-Reflection Coatings on Back-Illuminated Detectors

    Science.gov (United States)

    Hoenk, Michael E. (Inventor); Greer, Frank (Inventor); Nikzad, Shouleh (Inventor)

    2014-01-01

    A back-illuminated silicon photodetector has a layer of Al2O3 deposited on a silicon oxide surface that receives electromagnetic radiation to be detected. The Al2O3 layer has an antireflection coating deposited thereon. The Al2O3 layer provides a chemically resistant separation layer between the silicon oxide surface and the antireflection coating. The Al2O3 layer is thin enough that it is optically innocuous. Under deep ultraviolet radiation, the silicon oxide layer and the antireflection coating do not interact chemically. In one embodiment, the silicon photodetector has a delta-doped layer near (within a few nanometers of) the silicon oxide surface. The Al2O3 layer is expected to provide similar protection for doped layers fabricated using other methods, such as MBE, ion implantation and CVD deposition.

  17. Multi-layered, chemically bonded lithium-ion and lithium/air batteries

    Energy Technology Data Exchange (ETDEWEB)

    Narula, Chaitanya Kumar; Nanda, Jagjit; Bischoff, Brian L; Bhave, Ramesh R

    2014-05-13

    Disclosed are multilayer, porous, thin-layered lithium-ion batteries that include an inorganic separator as a thin layer that is chemically bonded to surfaces of positive and negative electrode layers. Thus, in such disclosed lithium-ion batteries, the electrodes and separator are made to form non-discrete (i.e., integral) thin layers. Also disclosed are methods of fabricating integrally connected, thin, multilayer lithium batteries including lithium-ion and lithium/air batteries.

  18. Multi-layered, chemically bonded lithium-ion and lithium/air batteries

    Science.gov (United States)

    Narula, Chaitanya Kumar; Nanda, Jagjit; Bischoff, Brian L; Bhave, Ramesh R

    2014-05-13

    Disclosed are multilayer, porous, thin-layered lithium-ion batteries that include an inorganic separator as a thin layer that is chemically bonded to surfaces of positive and negative electrode layers. Thus, in such disclosed lithium-ion batteries, the electrodes and separator are made to form non-discrete (i.e., integral) thin layers. Also disclosed are methods of fabricating integrally connected, thin, multilayer lithium batteries including lithium-ion and lithium/air batteries.

  19. Selectivity in capillary electrokinetic separations

    NARCIS (Netherlands)

    de Zeeuw, R.A; de Jong, G.J.; Ensing, K

    1999-01-01

    This review gives a survey of selectivity modes in capillary electrophoresis separations in pharmaceutical analysis and bioanalysis. Despite the high efficiencies of these separation techniques, good selectivity is required to allow quantitation or identification of a Chemistry and Toxicology, parti

  20. Physical Separation in the Workplace

    DEFF Research Database (Denmark)

    Stea, Diego; Foss, Nicolai Juul; Holdt Christensen, Peter

    2015-01-01

    Physical separation is pervasive in organizations, and has powerful effects on employee motivation and organizational behaviors. However, research shows that workplace separation is characterized by a variety of tradeoffs, tensions, and challenges that lead to both positive and negative outcomes...

  1. Separation of spin Seebeck effect and anomalous Nernst effect in Co/Cu/YIG

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Dai [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218 (United States); State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433 (China); Li, Yufan; Qu, D.; Chien, C. L., E-mail: clchien@jhu.edu [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Jin, Xiaofeng [State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433 (China)

    2015-05-25

    The spin Seebeck effect (SSE) and Anomalous Nernst effect (ANE) have been observed in Co/Cu/YIG (yttrium iron garnet) multi-layer structure, where the ferromagnetic insulator YIG acts as the pure spin injector and the ferromagnetic metal Co layer acts as the spin current detector. With the insertion of 5 nm Cu layer, the two ferromagnetic layers are decoupled, thus allowing unambiguous separation of the SSE and ANE contributions under the same experimental conditions in the same sample.

  2. Separation of spin Seebeck effect and anomalous Nernst effect in Co/Cu/YIG

    Science.gov (United States)

    Tian, Dai; Li, Yufan; Qu, D.; Jin, Xiaofeng; Chien, C. L.

    2015-05-01

    The spin Seebeck effect (SSE) and Anomalous Nernst effect (ANE) have been observed in Co/Cu/YIG (yttrium iron garnet) multi-layer structure, where the ferromagnetic insulator YIG acts as the pure spin injector and the ferromagnetic metal Co layer acts as the spin current detector. With the insertion of 5 nm Cu layer, the two ferromagnetic layers are decoupled, thus allowing unambiguous separation of the SSE and ANE contributions under the same experimental conditions in the same sample.

  3. Determine separations process strategy decision

    Energy Technology Data Exchange (ETDEWEB)

    Slaathaug, E.J.

    1996-01-01

    This study provides a summary level comparative analysis of selected, top-level, waste treatment strategies. These strategies include No Separations, Separations (high-level/low-level separations), and Deferred Separations of the tank waste. These three strategies encompass the full range of viable processing alternatives based upon full retrieval of the tank wastes. The assumption of full retrieval of the tank wastes is a predecessor decision and will not be revisited in this study.

  4. Composite separators and redox flow batteries based on porous separators

    Science.gov (United States)

    Li, Bin; Wei, Xiaoliang; Luo, Qingtao; Nie, Zimin; Wang, Wei; Sprenkle, Vincent L.

    2016-01-12

    Composite separators having a porous structure and including acid-stable, hydrophilic, inorganic particles enmeshed in a substantially fully fluorinated polyolefin matrix can be utilized in a number of applications. The inorganic particles can provide hydrophilic characteristics. The pores of the separator result in good selectivity and electrical conductivity. The fluorinated polymeric backbone can result in high chemical stability. Accordingly, one application of the composite separators is in redox flow batteries as low cost membranes. In such applications, the composite separator can also enable additional property-enhancing features compared to ion-exchange membranes. For example, simple capacity control can be achieved through hydraulic pressure by balancing the volumes of electrolyte on each side of the separator. While a porous separator can also allow for volume and pressure regulation, in RFBs that utilize corrosive and/or oxidizing compounds, the composite separators described herein are preferable for their robustness in the presence of such compounds.

  5. Separating Underdetermined Convolutive Speech Mixtures

    DEFF Research Database (Denmark)

    Pedersen, Michael Syskind; Wang, DeLiang; Larsen, Jan

    2006-01-01

    a method for underdetermined blind source separation of convolutive mixtures. The proposed framework is applicable for separation of instantaneous as well as convolutive speech mixtures. It is possible to iteratively extract each speech signal from the mixture by combining blind source separation...

  6. General Motors sidestream separator

    Energy Technology Data Exchange (ETDEWEB)

    Tessier, R.J.

    1981-01-01

    On February 15, 1980, the United States Environmental Protection Agency, acting pursuant to Paragraph 113(D) (4) of the Clean Air Act, issued to General Motors an innovative technology order covering fifteen coal-fired spreader-stoker boilers located at six General Motors plants in Ohio. The purpose and effect of this order was to permit General Motors time to develop a new, innovative technique for controlling particulate emissions from the specified boilers before compliance with the federally approved Ohio particulate control regulation was required. This new technology was christened, The Sidestream Separator, by General Motors. It provides a highly cost effective means of reducing particulate emissions below levels currently obtainable with conventionally used high efficiency mechanical collectors. These improvements could prove to be of substantial benefit to many industrial facilities with spreader-stoker coal-fired boilers that cannot be brought into compliance with applicble air pollution regulations except by application of far more expensive and unwieldly electrostatic precipitators (ESP's) or fabric filters (baghouses).

  7. PARAFFIN SEPARATION VACUUM DISTILLATION

    Directory of Open Access Journals (Sweden)

    Zaid A. Abdulrahman

    2013-05-01

    Full Text Available Simulated column performance curves were constructed for existing paraffin separation vacuum distillation column in LAB plant (Arab Detergent Company/Baiji-Iraq. The variables considered in this study are the thermodynamic model option, top vacuum pressure, top and bottom temperatures, feed temperature, feed composition & reflux ratio. Also simulated columns profiles for the temperature, vapor & liquid flow rates composition were constructed. Four different thermodynamic model options (SRK, TSRK, PR, and ESSO were used, affecting the results within 1-25% variation for the most cases.The simulated results show that about 2% to 8 % of paraffin (C10, C11, C12, & C13 present at the bottom stream which may cause a problem in the LAB plant. The major variations were noticed for the top temperature & the  paraffin weight fractions at bottom section with top vacuum pressure. The bottom temperature above 240 oC is not recommended because the total bottom flow rate decreases sharply, where as  the weight fraction of paraffins decrease slightly. The study gives evidence about a successful simulation with CHEMCAD

  8. On Poor Separation in Magnetically Driven Shock Tube

    DEFF Research Database (Denmark)

    Chang, C.T.

    1973-01-01

    Observations made at steady-state running conditions in a magnetically driven shock tube, with parallel-plate electrodes, showed that for a given discharge voltage, sufficient separation between the shock and the current-sheet occurred only at relatively high discharge pressures. As a comparison......, poor separations were also noted in conventional diaphragm-type shock tubes running at low initial pressures. It is demonstrated that the observed poor separation can be explained by a mass leakage, instead of through the wall boundary layer, but through the current-sheet itself....

  9. A mechanism of raft formation on both plasma membrane layers

    Science.gov (United States)

    Sornbundit, Kan; Modchang, Charin; Triampo, Wannapong; Triampo, Darapond; Nuttavut, Narin

    2013-10-01

    A double-layered membrane model is proposed to explain raft formation and induction on extracellular (outer) and cytoplasmic (inner) leaflets of plasma membranes in a situation where only the outer layer has a tendency to phase-separate. In the model, lipid exchange with the surrounding medium is allowed on both layers, but lipid exchange between layers is not allowed. Simulations display domain stabilization on both layers. The effect of the lipid recycling frequencies on stationary domain sizes is also investigated. It is found that stationary domain sizes decrease when lipid recycling frequencies are stronger. Linear stability analysis is used to verify the results.

  10. Bloch oscillations in chirped layered structures with metamaterials.

    Science.gov (United States)

    Davoyan, Arthur R; Shadrivov, Ilya V; Sukhorukov, Andrey A; Kivshar, Yuri S

    2008-03-01

    We analyze the Bloch oscillations of electromagnetic waves in chirped layered structures with alternating layers of negative-index metamaterial and conventional dielectric under the condition of the zero average refractive index. We consider the case when the chirp is introduced by varying the thickness of the layers linearly across the structure. We demonstrate that such structures can support three different types of the Bloch oscillations for electromagnetic waves associated with either propagating or evanescent guided modes. In particular, we predict a novel type of the Bloch oscillations associated with coupling between surface waves excited at the interfaces separating the layers of negative-index metamaterial and the layers of the conventional dielectric.

  11. VSWI Wetlands Advisory Layer

    Data.gov (United States)

    Vermont Center for Geographic Information — This dataset represents the DEC Wetlands Program's Advisory layer. This layer makes the most up-to-date, non-jurisdictional, wetlands mapping avaiable to the public...

  12. Basic Ozone Layer Science

    Science.gov (United States)

    Learn about the ozone layer and how human activities deplete it. This page provides information on the chemical processes that lead to ozone layer depletion, and scientists' efforts to understand them.

  13. Ozone Layer Protection

    Science.gov (United States)

    ... Search Search Ozone Layer Protection Share Facebook Twitter Google+ Pinterest Contact Us Ozone Layer Protection Welcome to ... Managing Refrigerant Emissions Stationary Refrigeration and Air Conditioning Car and Other Mobile Air Conditioning GreenChill Partnership Responsible ...

  14. On the scaling and unsteadiness of shock induced separation

    NARCIS (Netherlands)

    Souverein, L.J.

    2010-01-01

    Shock wave boundary layer interactions (SWBLI) are a common phenomenon in transonic and supersonic flows. The presence of shock waves, induced by specific geometrical configurations, causes a rapid increase of the pressure, which can lead to flow separation. Examples of such interactions are found i

  15. Niobia-silica and silica membranes for gas separation

    NARCIS (Netherlands)

    Boffa, Vittorio

    2008-01-01

    This thesis describes the development of ceramic membranes suitable for hydrogen separation and CO2 recovery from gaseous streams. The research work was focused on the three different parts of which gas selective ceramic membranes are composed, i.e., the microporous gas selective silica layer, the m

  16. Method of making a partial interlaminar separation composite system

    Science.gov (United States)

    Elber, W. (Inventor)

    1981-01-01

    An interlaminar separation system for composites is disclosed a thin layer of a perforated foil film is interposed between adjacent laminae of a composite formed from prepreg tapes. Laminae adherence takes place through the perforations and a composite structure with improved physical property characteristics is produced.

  17. Modeling the summertime Arctic cloudy boundary layer

    Energy Technology Data Exchange (ETDEWEB)

    Curry, J.A.; Pinto, J.O. [Univ. of Colorado, Boulder, CO (United States); McInnes, K.L. [CSIRO Division of Atmospheric Research, Mordialloc (Australia)

    1996-04-01

    Global climate models have particular difficulty in simulating the low-level clouds during the Arctic summer. Model problems are exacerbated in the polar regions by the complicated vertical structure of the Arctic boundary layer. The presence of multiple cloud layers, a humidity inversion above cloud top, and vertical fluxes in the cloud that are decoupled from the surface fluxes, identified in Curry et al. (1988), suggest that models containing sophisticated physical parameterizations would be required to accurately model this region. Accurate modeling of the vertical structure of multiple cloud layers in climate models is important for determination of the surface radiative fluxes. This study focuses on the problem of modeling the layered structure of the Arctic summertime boundary-layer clouds and in particular, the representation of the more complex boundary layer type consisting of a stable foggy surface layer surmounted by a cloud-topped mixed layer. A hierarchical modeling/diagnosis approach is used. A case study from the summertime Arctic Stratus Experiment is examined. A high-resolution, one-dimensional model of turbulence and radiation is tested against the observations and is then used in sensitivity studies to infer the optimal conditions for maintaining two separate layers in the Arctic summertime boundary layer. A three-dimensional mesoscale atmospheric model is then used to simulate the interaction of this cloud deck with the large-scale atmospheric dynamics. An assessment of the improvements needed to the parameterizations of the boundary layer, cloud microphysics, and radiation in the 3-D model is made.

  18. Fundamentals and Theory of HPTLC-Based Separation

    Science.gov (United States)

    Variyar, Prasad S.; Chatterjee, Suchandra; Sharma, Arun

    High-performance thin-layer chromatography (HPTLC) is a form of thin-layer chromatography (TLC) that provides superior separation power using optimized coating material, novel procedures for mobile-phase feeding, layer conditioning, and improved sample application. It promotes for higher separation efficiencies, shorter analysis time, lower amounts of mobile phase, and efficient data acquisition and processing. The major parameters that influence separation of the constituents within a mixture are the partition coefficients, retention factor (R f ), and capacity factor of the individual constituents on the plate, selectivity of the mobile and stationary phase to the solutes, and the plate height that decide the separation efficiency as well as resolution of the individual constituents within a mixture. The partition coefficient is defined as the molar concentration of the analyte in the stationary phase to that in the mobile phase. R f , a fundamental qualitative value, is expressed as the ratio of migration distances of an individual components of a mix relative to the mobile phase. Capacity factor (k) is a fundamental characteristic of a substance that determines its qualitative chromatographic behavior. It can be expressed as the ratio of the retention time of the substance in the stationary to that in the mobile phase and is influenced by the chemical nature of the two phases. The separation number (SN) that influences separation power of HPLC is defined as the highest possible number of components that are completely separated in a mixture under a gradient-free isocratic TLC. The efficacy of separation of two components of a mixture in a chromatogram is termed as resolution and is influenced by the selectivity of the components between the stationary and the mobile phase, mobile phase flow rate influenced by particle size and solvent strength that influence capacity factors.

  19. Separation of colloidal two dimensional materials by density gradient ultracentrifugation

    Energy Technology Data Exchange (ETDEWEB)

    Kuang, Yun; Song, Sha [State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Huang, Jinyang, E-mail: huangjy@mail.buct.edu.cn [Department of Mathematics, College of Science, Beijing University of Chemical Technology, Beijing 100029 (China); Sun, Xiaoming, E-mail: sunxm@mail.buct.edu.cn [State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029 (China)

    2015-04-15

    Two-dimensional (2D) materials have been made through various approaches but obtaining monodispersed simply by synthesis optimization gained little success, which highlighted the need for introducing nanoseparation methods. Density gradient ultracentrifugation method has emerged as a versatile and scalable method for sorting colloidal 2D nanomaterials. Isopycnic separation was applied on thickness-dependent separation of graphene nanosheets. And rate-zonal separation, as a more versatile separation method, demonstrated its capability in sorting nanosheets of chemically modified single layered graphene, layered double hydroxide, and even metallic Ag. Establishing such density gradient ultracentrifugation method not only achieves monodispersed nanosheets and provides new opportunities for investigation on size dependent properties of 2D materials, but also makes the surface modification possible by introducing “reaction zones” during sedimentation of the colloids. - Graphical abstract: Two-dimensional (2D) materials have been made through various approaches but obtaining monodispersed simply by synthesis optimization gained little success, which highlighted the need for introducing nanoseparation methods. Density gradient ultracentrifugation method has emerged as a versatile and scalable method for sorting colloidal 2D nanomaterials according to their size of thickness difference. Establishing such density gradient ultracentrifugation method not only achieves monodispersed nanosheets and provides new opportunities for investigation on size dependent properties of 2D materials, but also makes the surface modification possible by introducing “reaction zones” during sedimentation of the colloids. - Highlights: • Density gradient ultracentrifugation was applied on size separation of 2D material. • Isopycnic separation was applied on separation of low density materials. • Rate-zonal separation was applied on separation of large density materials. • Size

  20. An Undergraduate Organic Experiment Using Thin-Layer Chromatography.

    Science.gov (United States)

    Jones, Taylor B.; Jones, Tappey H.

    1985-01-01

    The separation of derivatives of aliphatic compounds (2,4-dinitrophenylhydrazones) is used to introduce methods and techniques typically employed in thin layer chromatography and to provide a clear illustration of chromatographic principles in general. Procedures used in the separation are presented. (JN)

  1. Content layer progressive coding of digital maps

    DEFF Research Database (Denmark)

    Forchhammer, Søren; Jensen, Ole Riis

    2000-01-01

    A new lossless context based method is presented for content progressive coding of limited bits/pixel images, such as maps, company logos, etc., common on the WWW. Progressive encoding is achieved by separating the image into content layers based on other predefined information. Information from...... already coded layers are used when coding subsequent layers. This approach is combined with efficient template based context bi-level coding, context collapsing methods for multi-level images and arithmetic coding. Relative pixel patterns are used to collapse contexts. The number of contexts are analyzed....... The new methods outperform existing coding schemes coding digital maps and in addition provide progressive coding. Compared to the state-of-the-art PWC coder, the compressed size is reduced to 60-70% on our layered test images....

  2. Properties of Ultra-Thin Hafnium Oxide and Interfacial Layer Deposited by Atomic Layer Deposition

    Institute of Scientific and Technical Information of China (English)

    Taeho Lee; Young-Bae Kim; Kyung-Il Hong; Duck-Kyun Choi; Jinho Ahn

    2004-01-01

    Ultra-thin hafnium-oxide gate dielectric films deposited by atomic layer deposition technique using HfCl4 and H2O precursor on a hydrogen-terminated Si substrate were investigated. X-ray photoelectron spectroscopy indicates that the interface layer is Hf-silicate rather than phase separated Hf-silicide and silicon oxide structure. The Hf-silicate interfacial layer partially changes into SiOx after high temperature annealing, resulting in a complex HfO2-silicate-SiOx dielectric structure. Electrical measurements confirms that HfO2 on Si is stable up to 700 ℃ for 30 s under N2 ambient.

  3. Injection Induced Mixing in Flows Separating From Smooth Surfaces

    Science.gov (United States)

    Adamczyk, John J. (Technical Monitor); Wundrow, David W.

    2004-01-01

    An analytic model for predicting the effect of unsteady local surface injection on the flow separating from a streamlined body at angle of attack is proposed. The model uses the premise that separation control results from enhanced mixing along the shear layer that develops between the main stream and the fluid in the underlying recirculation zone. High-Reynolds-number asymptotic methods are used to connect the unsteady surface injection to an instability wave propagating on the separating shear layer and then to the large-scale coherent structures that produce the increased mixing. The results is a tool that can guide the choice of fluid-actuator parameters to maximize flow-control effectiveness and may also facilitate computer-based numerical experiments.

  4. Laminar circular hydraulic jumps without separation

    Science.gov (United States)

    Dasgupta, Ratul; Tomar, Gaurav; Govindarajan, Rama

    2009-11-01

    The traditional inviscid criterion for the occurrence of a planar, standing hydraulic jump is to have the Froude number decrease downstream and go through a value of 1 at some location. Here, upstream propagating, small-amplitude, long, non-dispersive gravity waves are trapped, and non-linear steepening is said to result in a near-discontinuous height profile, but it is not clear how. Such a condition on the Froude number is shown in the present axisymmetric Navier-Stokes computations to hold for a circular jump as well. The relevance of non-linear steepening to a circular jump is therefore a question we wish to answer. In circular jumps, moreover, a region of recirculation is usually observed underneath the jump, underlining the importance of viscosity in this process. This led Tani (J. Phys. Soc. Japan, 1949) to hypothesise that boundary-layer separation was the cause of the circular jump. This hypothesis has been debated extensively and the possibility of circular jumps without separation hinted at. In our simulations, we are able to obtain circular hydraulic jumps without any flow separation. This, and the necessity or otherwise of viscosity in jump formation will be discussed.

  5. Modification of flow perturbations in a laminar separation bubble by heat transfer

    Science.gov (United States)

    Boiko, A. V.; Dovgal, A. V.; Sorokin, A. M.

    2017-02-01

    Laminar boundary layer separation in conditions of localized heat transfer is investigated at low subsonic velocity through wind-tunnel measurements and linear stability analysis. A backward-facing step flow is subjected to a stationary temperature variation generated by Peltier elements installed on the test model directly downstream of the separation line. The experimental and theoretical data clarify the response of velocity disturbances in the separation region to the temperature variation, the latter appearing primarily as a modifier of the initial wave spectrum of the amplifying separated layer oscillations.

  6. Intercalation of Layered Silicates, Layered Double Hydroxides, and Lead Iodide: Synthesis, Characterization and Properties.

    Science.gov (United States)

    Mehrotra, Vivek

    Layered silicates, layered double hydroxides, and lead iodide are lamellar solids that can incorporate guest species into the galleries between their layers. Various intercalated forms of these layered materials have been synthesized and their properties studied. The dielectric behavior of pristine fluorohectorite, a typical layered silicate, and Zn-Al layered double hydroxide is explained by considering the structural ordering and mobility of the intercalated water molecules, as well as models invoking fractal time processes and fractal structure. Intercalative polymerization of aniline and pyrrole into fluorohectorite leads to a multilayered structure consisting of single polymer chains alternately stacked with the 9.6 A thick silicate layers. The polymer chains are confined to the quasi two-dimensional interlayer space between the rigid host layers. The hybrid films exhibit highly anisotropic properties. The optical, electrical and mechanical behavior is discussed in terms of the molecular confinement of the polymer chains. Ethylenediamine functionalized C _{60} clusters have also been intercalated into fluorohectorite via an ion-exchange procedure. Intercalation results in an improved thermal stability of the functionalized C_{60} clusters. Rutherford backscattering spectrometry has been used to elucidate the mechanism of intercalative ion exchange of silver in muscovite mica, a layered silicate with a layer charge density of 2e per unit cell. It is proposed that ion-exchange progresses by intercalating successive galleries through the edges of the mica layers. Guest-host interactions have been studied in the system aniline-PbI_2. The optical and structural effects of aniline intercalation in lead iodide thin films is discussed. Intercalation leads to a large shift in the optical band gap of PbI_2. The observed change in band gap is not only due to the increased separation between the PbI_2 layers but also because of an electrostatic interaction between the

  7. Separators - Technology review: Ceramic based separators for secondary batteries

    Science.gov (United States)

    Nestler, Tina; Schmid, Robert; Münchgesang, Wolfram; Bazhenov, Vasilii; Schilm, Jochen; Leisegang, Tilmann; Meyer, Dirk C.

    2014-06-01

    Besides a continuous increase of the worldwide use of electricity, the electric energy storage technology market is a growing sector. At the latest since the German energy transition ("Energiewende") was announced, technological solutions for the storage of renewable energy have been intensively studied. Storage technologies in various forms are commercially available. A widespread technology is the electrochemical cell. Here the cost per kWh, e. g. determined by energy density, production process and cycle life, is of main interest. Commonly, an electrochemical cell consists of an anode and a cathode that are separated by an ion permeable or ion conductive membrane - the separator - as one of the main components. Many applications use polymeric separators whose pores are filled with liquid electrolyte, providing high power densities. However, problems arise from different failure mechanisms during cell operation, which can affect the integrity and functionality of these separators. In the case of excessive heating or mechanical damage, the polymeric separators become an incalculable security risk. Furthermore, the growth of metallic dendrites between the electrodes leads to unwanted short circuits. In order to minimize these risks, temperature stable and non-flammable ceramic particles can be added, forming so-called composite separators. Full ceramic separators, in turn, are currently commercially used only for high-temperature operation systems, due to their comparably low ion conductivity at room temperature. However, as security and lifetime demands increase, these materials turn into focus also for future room temperature applications. Hence, growing research effort is being spent on the improvement of the ion conductivity of these ceramic solid electrolyte materials, acting as separator and electrolyte at the same time. Starting with a short overview of available separator technologies and the separator market, this review focuses on ceramic-based separators

  8. Mathematical modelling of membrane separation

    DEFF Research Database (Denmark)

    Vinther, Frank

    This thesis concerns mathematical modelling of membrane separation. The thesis consists of introductory theory on membrane separation, equations of motion, and properties of dextran, which will be the solute species throughout the thesis. Furthermore, the thesis consist of three separate mathemat......This thesis concerns mathematical modelling of membrane separation. The thesis consists of introductory theory on membrane separation, equations of motion, and properties of dextran, which will be the solute species throughout the thesis. Furthermore, the thesis consist of three separate....... It is found that the probability of entering the pore is highest when the largest of the radii in the ellipse is equal to half the radius of the pore, in case of molecules with circular radius less than the pore radius. The results are directly related to the macroscopic distribution coefficient...

  9. Capillary Separation: Micellar Electrokinetic Chromatography

    Science.gov (United States)

    Terabe, Shigeru

    2009-07-01

    Micellar electrokinetic chromatography (MEKC), a separation mode of capillary electrophoresis (CE), has enabled the separation of electrically neutral analytes. MEKC can be performed by adding an ionic micelle to the running solution of CE without modifying the instrument. Its separation principle is based on the differential migration of the ionic micelles and the bulk running buffer under electrophoresis conditions and on the interaction between the analyte and the micelle. Hence, MEKC's separation principle is similar to that of chromatography. MEKC is a useful technique particularly for the separation of small molecules, both neutral and charged, and yields high-efficiency separation in a short time with minimum amounts of sample and reagents. To improve the concentration sensitivity of detection, several on-line sample preconcentration techniques such as sweeping have been developed.

  10. Separable programming theory and methods

    CERN Document Server

    Stefanov, Stefan M

    2001-01-01

    In this book, the author considers separable programming and, in particular, one of its important cases - convex separable programming Some general results are presented, techniques of approximating the separable problem by linear programming and dynamic programming are considered Convex separable programs subject to inequality equality constraint(s) and bounds on variables are also studied and iterative algorithms of polynomial complexity are proposed As an application, these algorithms are used in the implementation of stochastic quasigradient methods to some separable stochastic programs Numerical approximation with respect to I1 and I4 norms, as a convex separable nonsmooth unconstrained minimization problem, is considered as well Audience Advanced undergraduate and graduate students, mathematical programming operations research specialists

  11. Separation process using microchannel technology

    Science.gov (United States)

    Tonkovich, Anna Lee; Perry, Steven T.; Arora, Ravi; Qiu, Dongming; Lamont, Michael Jay; Burwell, Deanna; Dritz, Terence Andrew; McDaniel, Jeffrey S.; Rogers, Jr.; William A.; Silva, Laura J.; Weidert, Daniel J.; Simmons, Wayne W.; Chadwell, G. Bradley

    2009-03-24

    The disclosed invention relates to a process and apparatus for separating a first fluid from a fluid mixture comprising the first fluid. The process comprises: (A) flowing the fluid mixture into a microchannel separator in contact with a sorption medium, the fluid mixture being maintained in the microchannel separator until at least part of the first fluid is sorbed by the sorption medium, removing non-sorbed parts of the fluid mixture from the microchannel separator; and (B) desorbing first fluid from the sorption medium and removing desorbed first fluid from the microchannel separator. The process and apparatus are suitable for separating nitrogen or methane from a fluid mixture comprising nitrogen and methane. The process and apparatus may be used for rejecting nitrogen in the upgrading of sub-quality methane.

  12. Wastewater treatment with acoustic separator

    Science.gov (United States)

    Kambayashi, Takuya; Saeki, Tomonori; Buchanan, Ian

    2017-07-01

    Acoustic separation is a filter-free wastewater treatment method based on the forces generated in ultrasonic standing waves. In this report, a batch-system separator based on acoustic separation was demonstrated using a small-scale prototype acoustic separator to remove suspended solids from oil sand process-affected water (OSPW). By applying an acoustic separator to the batch use OSPW treatment, the required settling time, which was the time that the chemical oxygen demand (COD) decreased to the environmental criterion (<200 mg/L), could be shortened from 10 to 1 min. Moreover, for a 10 min settling time, the acoustic separator could reduce the FeCl3 dose as coagulant in OSPW treatment from 500 to 160 mg/L.

  13. Hereditary separability in Hausdorff continua

    Directory of Open Access Journals (Sweden)

    D. Daniel

    2012-04-01

    Full Text Available We consider those Hausdorff continua S such that each separable subspace of S is hereditarily separable. Due to results of Ostaszewski and Rudin, respectively, all monotonically normal spaces and therefore all continuous Hausdorff images of ordered compacta also have this property. Our study focuses on the structure of such spaces that also possess one of various rim properties, with emphasis given to rim-separability. In so doing we obtain analogues of results of M. Tuncali and I. Loncar, respectively.

  14. Turbulence Modeling of Flows with Extensive Crossflow Separation

    Directory of Open Access Journals (Sweden)

    Argyris G. Panaras

    2015-07-01

    Full Text Available The reasons for the difficulty in simulating accurately strong 3-D shock wave/turbulent boundary layer interactions (SBLIs and high-alpha flows with classical turbulence models are investigated. These flows are characterized by the appearance of strong crossflow separation. In view of recent additional evidence, a previously published flow analysis, which attributes the poor performance of classical turbulence models to the observed laminarization of the separation domain, is reexamined. According to this analysis, the longitudinal vortices into which the separated boundary layer rolls up in this type of separated flow, transfer external inviscid air into the part of the separation adjacent to the wall, decreasing its turbulence. It is demonstrated that linear models based on the Boussinesq equation provide solutions of moderate accuracy, while non-linear ones and others that consider the particular structure of the flow are more efficient. Published and new Reynolds Averaged Navier–Stokes (RANS simulations are reviewed, as well as results from a recent Large Eddy Simulation (LES study, which indicate that in calculations characterized by sufficient accuracy the turbulent kinetic energy of the reverse flow inside the separation vortices is very low, i.e., the flow is almost laminar there.

  15. Piezoelectric Resonator with Two Layers

    Science.gov (United States)

    Stephanou, Philip J. (Inventor); Black, Justin P. (Inventor)

    2013-01-01

    A piezoelectric resonator device includes: a top electrode layer with a patterned structure, a top piezoelectric layer adjacent to the top layer, a middle metal layer adjacent to the top piezoelectric layer opposite the top layer, a bottom piezoelectric layer adjacent to the middle layer opposite the top piezoelectric layer, and a bottom electrode layer with a patterned structure and adjacent to the bottom piezoelectric layer opposite the middle layer. The top layer includes a first plurality of electrodes inter-digitated with a second plurality of electrodes. A first one of the electrodes in the top layer and a first one of the electrodes in the bottom layer are coupled to a first contact, and a second one of the electrodes in the top layer and a second one of the electrodes in the bottom layer are coupled to a second contact.

  16. Using a Microscale Approach to Rapidly Separate and Characterize Three Photosynthetic Pigment Species from Fern

    Science.gov (United States)

    Ayudhya, Theppawut Israsena Na; Posey, Frederick T.; Tyus, Jessica C.; Dingra, Nin N.

    2015-01-01

    A rapid separation of three photosynthetic pigments (chlorophyll "a" and "b" and xanthophyll) from fern ("Polystichum acrostichoides") is described using microscale solvent extraction and traditional thin layer chromatography that minimizes use of harmful chemicals and lengthy procedures. The experiment introduces…

  17. Building biomedical materials layer-by-layer

    Directory of Open Access Journals (Sweden)

    Paula T. Hammond

    2012-05-01

    Full Text Available In this materials perspective, the promise of water based layer-by-layer (LbL assembly as a means of generating drug-releasing surfaces for biomedical applications, from small molecule therapeutics to biologic drugs and nucleic acids, is examined. Specific advantages of the use of LbL assembly versus traditional polymeric blend encapsulation are discussed. Examples are provided to present potential new directions. Translational opportunities are discussed to examine the impact and potential for true biomedical translation using rapid assembly methods, and applications are discussed with high need and medical return.

  18. Multi-layers castings

    Directory of Open Access Journals (Sweden)

    J. Szajnar

    2010-01-01

    Full Text Available In paper is presented the possibility of making of multi-layers cast steel castings in result of connection of casting and welding coating technologies. First layer was composite surface layer on the basis of Fe-Cr-C alloy, which was put directly in founding process of cast carbon steel 200–450 with use of preparation of mould cavity method. Second layer were padding welds, which were put with use of TIG – Tungsten Inert Gas surfacing by welding technology with filler on Ni matrix, Ni and Co matrix with wolfram carbides WC and on the basis on Fe-Cr-C alloy, which has the same chemical composition with alloy, which was used for making of composite surface layer. Usability for industrial applications of surface layers of castings were estimated by criterion of hardness and abrasive wear resistance of type metal-mineral.

  19. Parental separation and pediatric cancer

    DEFF Research Database (Denmark)

    Grant, Sally; Carlsen, Kathrine; Bidstrup, Pernille Envold Hansen

    2012-01-01

    The purpose of this study was to determine the risk for separation (ending cohabitation) of the parents of a child with a diagnosis of cancer.......The purpose of this study was to determine the risk for separation (ending cohabitation) of the parents of a child with a diagnosis of cancer....

  20. Fast Monaural Separation of Speech

    DEFF Research Database (Denmark)

    Pontoppidan, Niels Henrik; Dyrholm, Mads

    2003-01-01

    a Factorial Hidden Markov Model, with non-stationary assumptions on the source autocorrelations modelled through the Factorial Hidden Markov Model, leads to separation in the monaural case. By extending Hansens work we find that Roweis' assumptions are necessary for monaural speech separation. Furthermore we...

  1. Metals Separation by Liquid Extraction.

    Science.gov (United States)

    Malmary, G.; And Others

    1984-01-01

    As part of a project focusing on techniques in industrial chemistry, students carry out experiments on separating copper from cobalt in chloride-containing aqueous solution by liquid extraction with triisoctylamine solvent and search the literature on the separation process of these metals. These experiments and the literature research are…

  2. Vision 2020: 2000 Separations Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    Adler, Stephen [Center for Waster Reduction Technologies; Beaver, Earl [Practical Sustainability; Bryan, Paul [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Robinson, Sharon [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Watson, Jack [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2000-01-01

    This report documents the results of four workshops on the technology barriers, research needs, and priorities of the chemical, agricultural, petroleum, and pharmaceutical industries as they relate to separation technologies utilizing adsorbents, crystallization, distillation, extraction, membranes, separative reactors, ion exchange, bioseparations, and dilute solutions.

  3. Electrostatically enhanced core separator system

    Energy Technology Data Exchange (ETDEWEB)

    Easom, B.H.; Smolensky, L.A.; Altman, R.F. [LSR Technologies, Inc., Acton, MA (United States)

    1997-12-31

    The Electrostatically Enhanced Core Separator (EECS) system employs the same design principles as the mechanical Core Separator system plus an electrostatic separation enhancing technique. The EECS system contains a special type of separator, the EECS element, a conventional solids collector and means for flow recirculation. In the EECS system solids separation and collection are accomplished in two different components. The EECS element acts as a separator, not as a collector so particles are not collected on its walls. This eliminates or at least mitigates the problems associated with reentrainment (due to high or low dust resistivity), seepage (due to gas flow below the precipitator plates and over the hoppers), sneakage (due to gas flow both above and below the precipitator plates), and rapping reentrainment. If the EECS separation efficiency is high enough, particles cannot leave the system with the process stream. They recirculate until they are extracted by the collector. As a result, the separation efficiency of the EECS element determines the efficiency of the system, even if the collector efficiency is relatively low. 8 refs., 3 figs.

  4. Relational Parametricity and Separation Logic

    DEFF Research Database (Denmark)

    Birkedal, Lars; Yang, Hongseok

    2008-01-01

    Separation logic is a recent extension of Hoare logic for reasoning about programs with references to shared mutable data structures. In this paper, we provide a new interpretation of the logic for a programming language with higher types. Our interpretation is based on Reynolds's relational...... parametricity, and it provides a formal connection between separation logic and data abstraction. Udgivelsesdato: 2008...

  5. Testing Orions Fairing Separation System

    Science.gov (United States)

    Martinez, Henry; Cloutier, Chris; Lemmon, Heber; Rakes, Daniel; Oldham, Joe; Schlagel, Keith

    2014-01-01

    Traditional fairing systems are designed to fully encapsulate and protect their payload from the harsh ascent environment including acoustic vibrations, aerodynamic forces and heating. The Orion fairing separation system performs this function and more by also sharing approximately half of the vehicle structural load during ascent. This load-share condition through launch and during jettison allows for a substantial increase in mass to orbit. A series of component-level development tests were completed to evaluate and characterize each component within Orion's unique fairing separation system. Two full-scale separation tests were performed to verify system-level functionality and provide verification data. This paper summarizes the fairing spring, Pyramidal Separation Mechanism and forward seal system component-level development tests, system-level separation tests, and lessons learned.

  6. SUPPORTED DENSE CERAMIC MEMBRANES FOR OXYGEN SEPARATION

    Energy Technology Data Exchange (ETDEWEB)

    Timothy L. Ward

    2002-07-01

    Mixed-conducting ceramics have the ability to conduct oxygen with perfect selectivity at elevated temperatures, making them extremely attractive as membrane materials for oxygen separation and membrane reactor applications. While the conductivity of these materials can be quite high at elevated temperatures (typically 800-1000 C), much higher oxygen fluxes, or, alternatively, equivalent fluxes at lower temperatures, could be provided by supported thin or thick film membrane layers. Based on that motivation, the objective of this project was to explore the use of ultrafine aerosol-derived powder of a mixed-conducting ceramic material for fabrication of supported thick-film dense membranes. The project focused on the mixed-conducting ceramic composition SrCo{sub 0.5}FeO{sub x} (SCFO) because of the desirable permeability and stability of that material, as reported in the literature. Appropriate conditions to produce the submicron SrCo{sub 0.5}FeO{sub x} powder using aerosol pyrolysis were determined. Porous supports of the same composition were produced by partial sintering of a commercially obtained powder that possessed significantly larger particle size than the aerosol-derived powder. The effects of sintering conditions (temperature, atmosphere) on the porosity and microstructure of the porous discs were studied, and a standard support fabrication procedure was adopted. Subsequently, a variety of paste and slurry formulations were explored utilizing the aerosol-derived SCFO powder. These formulations were applied to the porous SCFO support by a doctor blade or spin coating procedure. Sintering of the supported membrane layer was then conducted, and additional layers were deposited and sintered in some cases. The primary characterization methods were X-ray diffraction and scanning electron microscopy, and room-temperature nitrogen permeation was used to assess defect status of the membranes.We found that non-aqueous paste/slurry formulations incorporating

  7. Analysis of low Reynolds number separation bubbles using semiempirical methods

    Science.gov (United States)

    Schmidt, Gordon S.; Mueller, Thomas J.

    1989-01-01

    The formation and growth of transitional separation bubbles can significantly affect boundary-layer development on airfoils operating at low chord Reynolds numbers. Of primary concern is the change in boundary-layer thickness between laminar separation and turbulent reattachment. This can be estimated using semiempirical methods, such as the one devised by Horton (1968), which are based on solutions to the integral forms of the boundary-layer equations. The applicability of these methods at low Reynolds numbers was investigated using hot-wire measurements of bubbles formed on an NACA 66(3)-018 airfoil at chord Reynolds numbers of 50,000-200,000. The momentum thickness growth between separation and transition was found to be similar to that predicted for a laminar half-jet and appears to be influenced by the momentum thickness Reynolds number at separation. This parameter also was found to have a noticeable effect on the Reynolds number based on the length of a bubble's laminar portion.

  8. Micro-separation toward systems biology.

    Science.gov (United States)

    Liu, Bi-Feng; Xu, Bo; Zhang, Guisen; Du, Wei; Luo, Qingming

    2006-02-17

    Current biology is experiencing transformation in logic or philosophy that forces us to reevaluate the concept of cell, tissue or entire organism as a collection of individual components. Systems biology that aims at understanding biological system at the systems level is an emerging research area, which involves interdisciplinary collaborations of life sciences, computational and mathematical sciences, systems engineering, and analytical technology, etc. For analytical chemistry, developing innovative methods to meet the requirement of systems biology represents new challenges as also opportunities and responsibility. In this review, systems biology-oriented micro-separation technologies are introduced for comprehensive profiling of genome, proteome and metabolome, characterization of biomolecules interaction and single cell analysis such as capillary electrophoresis, ultra-thin layer gel electrophoresis, micro-column liquid chromatography, and their multidimensional combinations, parallel integrations, microfabricated formats, and nano technology involvement. Future challenges and directions are also suggested.

  9. Ceria Based Composite Membranes for Oxygen Separation

    DEFF Research Database (Denmark)

    Gurauskis, Jonas; Ovtar, Simona; Kaiser, Andreas

    2014-01-01

    . Composite thin film was deposited on tubular structural support made of porous MgO phase. Porous CGO layers (20 μm) were implemented as backbones for catalytic phase on both sides of a composite membrane (Fig. 1). During initial trials, the catalytic phase free CGO/LSF composite membranes demonstrated......Mixed ionic-electronic conducting membranes for oxygen gas separation are attracting a lot of interest due to their promising potential for the pure oxygen and the syngas production. Apart from the need for a sufficiently high oxygen permeation fluxes, the prolonged stability of these membranes...... under the large oxygen potential gradients at elevated temperatures is decisive for the future applications. The gadolinium doped cerium oxide (CGO) based composite membranes are considered as promising candidates due to inherent stability of CGO phase. The CGO matrix is a main oxygen ion transporter...

  10. Metallic Membranes for High Temperature Hydrogen Separation

    DEFF Research Database (Denmark)

    Ma, Y.H.; Catalano, Jacopo; Guazzone, Federico

    2013-01-01

    Composite palladium membranes have extensively been studied in laboratories and, more recently, in small pilot industrial applications for the high temperature separation of hydrogen from reactant mixtures such as water-gas shift (WGS) reaction or methane steam reforming (MSR). Composite Pd...... membrane fabrication methods have matured over the last decades, and the deposition of very thin films (1–5 µm) of Pd over porous ceramics or modified porous metal supports is quite common. The H2 permeances and the selectivities achieved at 400–500 °C were in the order of 50–100 Nm3/m/h/bar0.5 and greater...... than 1000, respectively. This chapter describes in detail composite Pd-based membrane preparation methods, which consist of the grading of the support and the deposition of the dense metal layer, their performances, and their applications in catalytic membrane reactors (CMRs) at high temperatures (400...

  11. Optical and Electrical Characteristics of Graphene Double Layer Formed by a Double Transfer of Graphene Single Layers.

    Science.gov (United States)

    Kim, Young Jun; Bae, Gi Yoon; Chun, Sungwoo; Park, Wanjun

    2016-03-01

    We demonstrate formation of double layer graphene by means of a double transfer using two single graphene layers grown by a chemical vapor deposition method. It is observed that shiftiness and broadness in the double-resonance of Raman scattering are much weaker than those of bilayer graphene formed naturally. Transport characteristics examined from transmission line measurements and field effect transistors show the similar behavior with those of single layer graphene. It indicates that interlayer separation, in electrical view, is large enough to avoid correlation between layers for the double layer structure. It is also observed from a transistor with the double layer graphene that molecules adsorpted on two inner graphene surfaces in the double layered structure are isolated and conserved from ambient environment.

  12. Pseudo-stationary separation materials for highly parallel separations.

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Anup K.; Palmer, Christopher (University of Montana, Missoula, MT)

    2005-05-01

    Goal of this study was to develop and characterize novel polymeric materials as pseudostationary phases in electrokinetic chromatography. Fundamental studies have characterized the chromatographic selectivity of the materials as a function of chemical structure and molecular conformation. The selectivities of the polymers has been studied extensively, resulting in a large body of fundamental knowledge regarding the performance and selectivity of polymeric pseudostationary phases. Two polymers have also been used for amino acid and peptide separations, and with laser induced fluorescence detection. The polymers performed well for the separation of derivatized amino acids, and provided some significant differences in selectivity relative to a commonly used micellar pseudostationary phase. The polymers did not perform well for peptide separations. The polymers were compatible with laser induced fluorescence detection, indicating that they should also be compatible with chip-based separations.

  13. WASTE PRINTED CIRCUIT BOARDS SEPARATION IN ELECTROSTATIC SEPARATOR

    Directory of Open Access Journals (Sweden)

    Branimir Fuk

    2012-12-01

    Full Text Available Printed circuit boards from electronic waste are very important source of precious metals by recycling. The biggest challenge is liberation and separation of useful components; thin film which contains copper, zinc, tin, lead and precious metals like silver, gold and palladium from non useful components; polymers, ceramics and glass fibbers. The paper presents results for separation of shredded printed circuit boards from TV sets in electrostatic separator. Testing where conducted with material class 2/1 and 1/0.5 mm in laboratory on equipment for mineral processing. Results showed influence from independent variable; separation knife gradient, drum rotation speed and voltage on concentrate quality and recovery (the paper is published in Croatian.

  14. Multi-layer coatings for bipolar rechargeable batteries with enhanced terminal voltage

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, Joseph C.; Kaschmitter, James; Pierce, Steve

    2017-06-06

    A method for producing a multi-layer bipolar coated cell according to one embodiment includes applying a first active cathode material above a substrate to form a first cathode; applying a first solid-phase ionically-conductive electrolyte material above the first cathode to form a first electrode separation layer; applying a first active anode material above the first electrode separation layer to form a first anode; applying an electrically conductive barrier layer above the first anode; applying a second active cathode material above the anode material to form a second cathode; applying a second solid-phase ionically-conductive electrolyte material above the second cathode to form a second electrode separation layer; applying a second active anode material above the second electrode separation layer to form a second anode; and applying a metal material above the second anode to form a metal coating section. In another embodiment, the anode is formed prior to the cathode. Cells are also disclosed.

  15. Hydrogen isotope separation; Separation isotopique de l'hydrogene

    Energy Technology Data Exchange (ETDEWEB)

    Leterq, D.; Guidon, H. [CEA Bruyeres-le-Chatel, 91 (France)

    2001-12-01

    CEA-DAM has been operating for more than 20 years hydrogen isotopes separation by batch chromatography with palladium coated on alumina as absorbing material. The efforts have been focused on the development of two new separation processes: TCAP (Thermal Cycling Absorption Process) and chromatography an molecular sieve at 77 K. H{sub 2}/D{sub 2} first tests results are promising. (authors)

  16. Particle separations by electrophoretic techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ballou, N.E.; Petersen, S.L.; Ducatte, G.R.; Remcho, V.T.

    1996-03-01

    A new method for particle separations based on capillary electrophoresis has been developed and characterized. It uniquely separates particles according to their chemical nature. Separations have been demonstrated with chemically modified latex particles and with inorganic oxide and silicate particles. Separations have been shown both experimentally and theoretically to be essentially independent of particle size in the range of about 0.2 {mu}m to 10 {mu}m. The method has been applied to separations of U0{sub 2} particles from environmental particulate material. For this, an integrated method was developed for capillary electrophoretic separation, collection of separated fractions, and determinations of U0{sub 2} and environmental particles in each fraction. Experimental runs with the integrated method on mixtures of UO{sub 2} particles and environmental particulate material demonstrated enrichment factors of 20 for UO{sub 2} particles in respect to environmental particles in the U0{sub 2}containing fractions. This enrichment factor reduces the costs and time for processing particulate samples by the lexan process by a factor of about 20.

  17. Human dermis separation via ultra-short pulsed laser plasma-mediated ablation

    Energy Technology Data Exchange (ETDEWEB)

    Huang Huan; Guo Zhixiong, E-mail: guo@jove.rutgers.ed [Department of Mechanical and Aerospace Engineering, Rutgers, State University of New Jersey, Piscataway, NJ 08854 (United States)

    2009-08-21

    In vitro layer separation of human dermal tissues via laser plasma-mediated ablation was successfully conducted for the first time. The ablation of wet dermis was generated using a 900 fs ultra-short pulsed laser with the wavelength centred at 1552 nm. The ablation and separation results were imaged and measured by scanning electron microscopy. The dermis ablation threshold was determined as 9.65 {+-} 1.21 J cm{sup -2} and the incubation factor was found as 0.46 {+-} 0.03. Histological examinations were performed to find proper laser parameters for dermis ablation and separation with minimal thermal damage. No thermal damage was found in the single line ablation results when the pulse overlap rate was not over 5 pulses {mu}m{sup -1}. Even in the multi-line ablation, thermal damage was insignificant and the lateral damage zone was generally within 5 {mu}m in the results with 100 continuously repeated line scans. The separation of a whole piece of wet dermal tissue into two thin layers was presented. Several separation tests with different layer thicknesses from 200 to 600 {mu}m were completed. The unevenness of the separated layers was generally under 10%. The cohesion and morphology of the separated tissue layers were not altered.

  18. Correlated lateral phase separations in stacks of lipid membranes

    Energy Technology Data Exchange (ETDEWEB)

    Hoshino, Takuma, E-mail: hoshino-takuma@ed.tmu.ac.jp [Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Tokyo 192-0397 (Japan); Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Ramat Aviv, Tel Aviv 69978 (Israel); Kavli Institute for Theoretical Physics China, CAS, Beijing 100190 (China); Komura, Shigeyuki, E-mail: komura@tmu.ac.jp [Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Tokyo 192-0397 (Japan); Kavli Institute for Theoretical Physics China, CAS, Beijing 100190 (China); Andelman, David, E-mail: andelman@post.tau.ac.il [Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Ramat Aviv, Tel Aviv 69978 (Israel); Kavli Institute for Theoretical Physics China, CAS, Beijing 100190 (China)

    2015-12-28

    Motivated by the experimental study of Tayebi et al. [Nat. Mater. 11, 1074 (2012)] on phase separation of stacked multi-component lipid bilayers, we propose a model composed of stacked two-dimensional Ising spins. We study both its static and dynamical features using Monte Carlo simulations with Kawasaki spin exchange dynamics that conserves the order parameter. We show that at thermodynamical equilibrium, due to strong inter-layer correlations, the system forms a continuous columnar structure for any finite interaction across adjacent layers. Furthermore, the phase separation shows a faster dynamics as the inter-layer interaction is increased. This temporal behavior is mainly due to an effective deeper temperature quench because of the larger value of the critical temperature, T{sub c}, for larger inter-layer interaction. When the temperature ratio, T/T{sub c}, is kept fixed, the temporal growth exponent does not increase and even slightly decreases as a function of the increased inter-layer interaction.

  19. Controlled topological transitions in thin film phase separation

    CERN Document Server

    Hennessy, Matthew G; Goriely, Alain; Münch, Andreas; Wagner, Barbara

    2014-01-01

    In this paper the evolution of a binary mixture in a thin-film geometry with a wall at the top and bottom is considered. By bringing the mixture into its miscibility gap so that no spinodal decomposition occurs in the bulk, a slight energetic bias of the walls towards each one of the constituents ensures the nucleation of thin boundary layers that grow until the constituents have moved into one of the two layers. These layers are separated by an interfacial region where the composition changes rapidly. Conditions that ensure the separation into two layers with a thin interfacial region are investigated based on a phase-field model. Using matched asymptotic expansions a corresponding sharp-interface problem for the location of the interface is established. It is then argued that this newly created two-layer system is not at its energetic minimum but destabilizes into a controlled self-replicating pattern of trapezoidal vertical stripes by minimizing the interfacial energy between the phases while conserving th...

  20. Controlled Topological Transitions in Thin-Film Phase Separation

    KAUST Repository

    Hennessy, Matthew G.

    2015-01-01

    © 2015 Society for Industrial and Applied Mathematics. In this paper the evolution of a binary mixture in a thin-film geometry with a wall at the top and bottom is considered. By bringing the mixture into its miscibility gap so that no spinodal decomposition occurs in the bulk, a slight energetic bias of the walls toward each one of the constituents ensures the nucleation of thin boundary layers that grow until the constituents have moved into one of the two layers. These layers are separated by an interfacial region where the composition changes rapidly. Conditions that ensure the separation into two layers with a thin interfacial region are investigated based on a phase-field model. Using matched asymptotic expansions a corresponding sharp-interface problem for the location of the interface is established. It is then argued that this newly created two-layer system is not at its energetic minimum but destabilizes into a controlled self-replicating pattern of trapezoidal vertical stripes by minimizing the interfacial energy between the phases while conserving their area. A quantitative analysis of this mechanism is carried out via a thin-film model for the free interfaces, which is derived asymptotically from the sharp-interface model.

  1. 2007 Program of Study: Boundary Layers

    Science.gov (United States)

    2008-06-01

    PM Coalescence of charged water droplets Andrew Belmonte, Pennsylvania State University August 9 - 10:30 AM Multiscale analysis of strongly...Properties of Helium Near the Liquid-Vapor Critical Point. J. low Temp. Phys. 46, 115-135. [15] Polezhaev, V. I. and Soboleva, E. B. 2004 Rayleigh...through which potassium permanganate was added in most of the experiments in order to detect a possible appearance of boundary layer separation and

  2. Efficient separations & processing crosscutting program

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-08-01

    The Efficient Separations and Processing Crosscutting Program (ESP) was created in 1991 to identify, develop, and perfect chemical and physical separations technologies and chemical processes which treat wastes and address environmental problems throughout the DOE complex. The ESP funds several multiyear tasks that address high-priority waste remediation problems involving high-level, low-level, transuranic, hazardous, and mixed (radioactive and hazardous) wastes. The ESP supports applied research and development (R & D) leading to the demonstration or use of these separations technologies by other organizations within the Department of Energy (DOE), Office of Environmental Management.

  3. Towards a fully printable battery : robocast deposition of separators.

    Energy Technology Data Exchange (ETDEWEB)

    Atanassov, Plamen Borissov (University of New Mexico); Fenton, Kyle Ross (University of New Mexico); Apblett, Christopher Alan

    2010-04-01

    The development of thin batteries has presented several interesting problems which are not seen in traditional battery sizes. As the size of a battery reaches a minimum, the usable capacity of the battery decreases due to the fact that the major constituent of the battery becomes the package and separator. As the size decreases, the volumetric contribution from the package and separator increases. This can result in a reduction of capacity from these types of batteries of nearly all of the available power. The development of a method for directly printing the battery layers, including the package, in place would help to alleviate this problem. The technology used in this paper to directly print battery components is known as robocasting and is capable of direct writing of slurries in complex geometries. This method is also capable of conformally printing on three dimensional surfaces, opening up the possibility of novel batteries based on tailoring battery footprints to conform to the available substrate geometry. Interfacial resistance can also be reduced by using the direct write method. Each layer is printed in place on the battery stack instead of being stacked one at a time. This ensures an intimate contact and seal at every interface within the cell. By limiting the resistance at these interfaces, we effectively help increase the useable capacity of our battery through increase transport capability. We have developed methodology for printing several different separator materials for use in a lithium cell. When combined with a printable cathode comprised of LiFePO{sub 4} (as seen in Figure 1) and a lithium anode, our battery is capable of delivering a theoretical capacity of 170 mAh g{sup -1}. This capacity is diminished by transport phenomena within the cell which limit the transport rate of the lithium ions during the discharge cycle. The material set chosen for the printable separator closely resemble those used in commercially available separators in order

  4. Study of frequency and time responses of a separated absorption and multiplication region avalanche photodiode

    CERN Document Server

    Banoushi, A; Setayeshi, S

    2003-01-01

    In this paper, the frequency and time responses of a separated absorption and multiplication avalanche photodiode are studied by solving the carrier continuity equations, in the low gain regime. The discrepancy between the carrier velocities in different layers is considered for the first time. It is shown that considerable error occurs, if the device d characteristics are calculated assuming uniformly distributed velocities in the depletion layer, especially when the different layers have almost equal thickness.

  5. Lunar Soil Particle Separator Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Lunar Soil Particle Separator (LSPS) is an innovative method to beneficiate soil prior to in-situ resource utilization (ISRU). The LSPS improves ISRU oxygen...

  6. Selective Photoinitiated Electrophoretic Separator Project

    Data.gov (United States)

    National Aeronautics and Space Administration — To address NASA Johnson Space Center needs for gas separation and collection technology for lunar in-situ resource utilization, Physical Optics Corporation (POC)...

  7. Magnetic separation in microfluidic systems

    DEFF Research Database (Denmark)

    Smistrup, Kristian

    2007-01-01

    This Ph.D. thesis presents theory, modeling, design, fabrication, experiments and results for microfluidic magnetic separators. A model for magnetic bead movement in a microfluidic channel is presented, and the limits of the model are discussed. The effective magnetic field gradient is defined...... for fabrication of silicon based systems. This fabrication scheme is explained, and it is shown how, it is applied with variations for several designs of magnetic separators. An experimental setup for magnetic separation experiments has been developed. It has been coupled with an image analysis program....... It is shown conceptually how such a system can be applied for parallel biochemical processing in a microfluidic system. ’Passive’ magnetic separators are presented, where on-chip soft magnetic elements are magnetized by an external magnetic field and create strong magnetic fields and gradients inside...

  8. Chiral separation of agricultural fungicides.

    Science.gov (United States)

    Pérez-Fernández, Virginia; García, Maria Ángeles; Marina, Maria Luisa

    2011-09-23

    Fungicides are very important and diverse environmental and agricultural concern species. Their determination in commercial formulations or environmental matrices, requires highly efficient, selective and sensitive methods. A significant number of these chemicals are chiral with the activity residing usually in one of the enantiomers. The different toxicological and degradation behavior observed in many cases for fungicide enantiomers, results in the need to investigate them separately. For this purpose, separation techniques such as GC, HPLC, supercritical fluid chromatography (SFC) and CE have widely been employed although, at present, HPLC still dominates chromatographic chiral analysis of fungicides. This review covers the literature concerning the enantiomeric separation of fungicides usually employed in agriculture grouping the chiral separation methodologies developed for their analysis in environmental, biological, and food samples.

  9. Lunar Soil Particle Separator Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Lunar Soil Particle Separator (LSPS) is an innovative method to beneficiate soil prior to in-situ resource utilization (ISRU). The LSPS can improve ISRU oxygen...

  10. Article separation apparatus and method for unit operations

    Science.gov (United States)

    Pardini, Allan F.; Gervais, Kevin L.; Mathews, Royce A.; Hockey, Ronald L.

    2010-06-22

    An apparatus and method are disclosed for separating articles from a group of articles. The apparatus includes a container for containing one or more articles coupled to a suitable fluidizer for suspending articles within the container and transporting articles to an induction tube. A portal in the induction tube introduces articles singly into the induction tube. A vacuum pulls articles through the induction tube separating the articles from the group of articles in the container. The apparatus and method can be combined with one or more unit operations or modules, e.g., for inspecting articles, assessing quality of articles, or ascertaining material properties and/or parameters of articles, including layers thereof.

  11. Microfluidic Device for Continuous Magnetophoretic Separation of Red Blood Cells

    CERN Document Server

    Iliescu, Ciprian; Avram, Marioara; Xu, G; Avram, Andrei

    2008-01-01

    This paper presents a microfluidic device for magnetophoretic separation red blood cells from blood under contionous flow. The separation method consist of continous flow of a blood sample (diluted in PBS) through a microfluidic channel which presents on the bottom "dots" of feromagnetic layer. By appling a magnetic field perpendicular on the flowing direction, the feromagnetic "dots" generates a gradient of magnetic field which amplifies the magnetic force. As a result, the red blood cells are captured on the bottom of the microfluidic channel while the rest of the blood is collected at the outlet. Experimental results show that an average of 95 % of red blood cells are trapped in the device

  12. Shark Skin Bristling as a Passive Mechanism for Separation Control

    Science.gov (United States)

    Wheelus, Jennifer; Lang, Amy; Jones, Emily

    2011-11-01

    The skin of fast-swimming sharks is proposed to have mechanisms to reduce drag and delay flow separation. The skin of fast-swimming and agile sharks is covered with small teeth-like denticles on the order of 0.2 mm. The shortfin mako is one of the fastest and most agile ocean predators creating the need to minimize its pressure drag by controlling flow separation. Biological studies of the shortfin mako skin have shown the passive bristling angle of their denticles to exceed 50 degrees in areas on the flank corresponding to the locations likely to experience separation first. It is proposed that reversing flow, as occurs at the onset of separation in a turbulent boundary layer, would activate denticle bristling and hinder local separation from leading to global separation over the shark. This study focuses on the denticle reaction to various reversed flow conditions using a pulsating jet. Mako shark skin was subjected to numerous reversed flow velocities to determine the bristling onset velocity. Digital Particle Image Velocimetry (DPIV) and digital video were used to determine the flow conditions and denticle behavior. The effect of reversed flow velocity on denticle bristling and its relation to separation control will be discussed. Research funded by NSF (award 0932352).

  13. Robust multiculturality emerges from layered social influence

    CERN Document Server

    Battiston, Federico; Latora, Vito; Miguel, Maxi San

    2016-01-01

    Why is our society multicultural? Based on the two mechanisms of homophily and social influence, the classical model for the dissemination of cultures proposed by Axelrod predicts the existence of a fragmented regime where different cultures can coexist in a social network. However, in such model the multicultural regime is achievable only when a high number of cultural traits is present, and is not robust against cultural drift, i.e. the spontaneous mutations of agents' traits. In real systems, social influence is inherently organised in layers, meaning that individuals tend to diversify their connections according to the topic on which they interact. In this work we show that the observed persistence of multiculturality in real-world social systems is a natural consequence of the layered organisation of social influence. We find that the critical number of cultural traits that separates the monocultural and the multicultural regimes depends on the redundancy of pairwise connections across layers. Surprising...

  14. Separators for Lithium Ion Batteries

    Institute of Scientific and Technical Information of China (English)

    G.C.Li; H.P.Zhang; Y.P.Wu

    2007-01-01

    1 Results A separator for rechargeable batteries is a microporous membrane placed between electrodes of opposite polarity, keeping them apart to prevent electrical short circuits and at the same time allowing rapid transport of lithium ions that are needed to complete the circuit during the passage of current in an electrochemical cell, and thus plays a key role in determining the performance of the lithium ion battery. Here provides a comprehensive overview of various types of separators for lithium io...

  15. Lithium isotope separation by laser

    Energy Technology Data Exchange (ETDEWEB)

    Arisawa, T.; Maruyama, Y.; Suzuki, Y.; Shiba, K.

    1982-01-01

    A lithium isotope separation was performed using a laser isotope separation method. It was found that the lithium atoms with a natural isotopic abundance enhanced its /sup 6/Li concentration up to over 90% by tuning the laser wavelength to the /sup 2/Psub(1/2) of /sup 6/Li. Too high power, however, leads to a loss of enrichment due to the power broadening effect which was analysed by the equation of motion of density matrices.

  16. Fuel-Cell Water Separator

    Science.gov (United States)

    Burke, Kenneth Alan; Fisher, Caleb; Newman, Paul

    2010-01-01

    The main product of a typical fuel cell is water, and many fuel-cell configurations use the flow of excess gases (i.e., gases not consumed by the reaction) to drive the resultant water out of the cell. This two-phase mixture then exits through an exhaust port where the two fluids must again be separated to prevent the fuel cell from flooding and to facilitate the reutilization of both fluids. The Glenn Research Center (GRC) has designed, built, and tested an innovative fuel-cell water separator that not only removes liquid water from a fuel cell s exhaust ports, but does so with no moving parts or other power-consuming components. Instead it employs the potential and kinetic energies already present in the moving exhaust flow. In addition, the geometry of the separator is explicitly intended to be integrated into a fuel-cell stack, providing a direct mate with the fuel cell s existing flow ports. The separator is also fully scalable, allowing it to accommodate a wide range of water removal requirements. Multiple separators can simply be "stacked" in series or parallel to adapt to the water production/removal rate. GRC s separator accomplishes the task of water removal by coupling a high aspect- ratio flow chamber with a highly hydrophilic, polyethersulfone membrane. The hydrophilic membrane readily absorbs and transports the liquid water away from the mixture while simultaneously resisting gas penetration. The expansive flow path maximizes the interaction of the water particles with the membrane while minimizing the overall gas flow restriction. In essence, each fluid takes its corresponding path of least resistance, and the two fluids are effectively separated. The GRC fuel-cell water separator has a broad range of applications, including commercial hydrogen-air fuel cells currently being considered for power generation in automobiles.

  17. Development of Radiochemical Separation Technology

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eil Hee; Kim, K. W.; Yang, H. B. (and others)

    2007-06-15

    This project of the second phase was aimed at the development of basic unit technologies for advanced partitioning, and the application tests of pre-developed partitioning technologies for separation of actinides by using a simulated multi-component radioactive waste containing Am, Np, Tc, U and so on. The goals for recovery yield of TRU, and for purity of Tc are high than 99% and about 99%, respectively. The work scopes and contents were as follows. 1). For the development of basic unit technologies for advanced partitioning. 1. Development of technologies for co-removal of TRU and for mutual separation of U and TRU with a reduction-complexation reaction. 2. Development of extraction system for high-acidity co-separation of An(+3) and Ln(+3) and its radiolytic evaluation. 3. Synthesis of extractants for the selective separation of An(+3) and its relevant extraction system development. 4. Development of a hybrid system for the recovery of noble metals and its continuous separation tests. 5. Development of electrolytic system for the decompositions of N-NO3 and N-NH3 compounds to nitrogen gas. 2). For the application test of pre-developed partitioning technologies for the separation of actinide elements in a simulated multi-component solution equivalent to HLW level. 1. Co-separation of Tc, Np and U by a (TBP-TOA)/NDD system. 2. Mutual-separation of Am, Cm and RE elements by a (Zr-DEHPA)/NDD system. All results will be used as the fundamental data for the development of advanced partitioning process in the future.

  18. Optics of mass separator I

    Energy Technology Data Exchange (ETDEWEB)

    Balestrini, S.J.

    1981-07-01

    The ion optics of an existing mass separator are documented. The elctrostatic and magnetic stages are analyzed theoretically, both separately and in combination, by paying particular attention to the ion trajectories, the linear and angular magnifications, and the dispersion. The possibility of converting the magnet into a tunable unit by means of current-carrying elements in the gap is demonstrated. The feasibility of correction coils constructed from printed circuit board is shown.

  19. Nanostructural drug-inorganic clay composites: Structure, thermal property and in vitro release of captopril-intercalated Mg Al-layered double hydroxides

    Science.gov (United States)

    Zhang, Hui; Zou, Kang; Guo, Shaohuan; Duan, Xue

    2006-06-01

    A nanostructural drug-inorganic clay composite involving a pharmaceutically active compound captopril (Cpl) intercalated Mg-Al-layered double hydroxides (Cpl-LDHs) with Mg/Al molar ratio of 2.06 has been assembled by coprecipitation method. Powder X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR) and Raman spectra analysis indicate a successful intercalation of Cpl between the layers with a vertical orientation of Cpl disulphide-containing S-S linkage. SEM photo indicates that as-synthesized Cpl-LDHs possess compact and non-porous structure with approximately and linked elliptical shape particles of ca. 50 nm. TG-DTA analyses suggest that the thermal stability of intercalated organic species is largely enhanced due to host-guest interaction involving the hydrogen bond compared to pure form before intercalation. The in vitro release studies show that both the release rate and release percentages markedly decrease with increasing pH from 4.60 to 7.45 due to possible change of release mechanism during the release process. The kinetic simulation for the release data, and XRD and FT-IR analyses for samples recovered from release media indicate that the dissolution mechanism is mainly responsible for the release behaviour of Cpl-LDHs at pH 4.60, while the ion-exchange one is responsible for that at pH 7.45.

  20. Separation mechanisms and fluid flow in oil/water separation

    Energy Technology Data Exchange (ETDEWEB)

    Celius, H.K.; Knudsen, B. [IKU Petroleumsforskning A/S, Trondheim (Norway); Hafskjold, B.; Hansen, E.W. [Selskapet for Industriell og Teknisk Forskning, Trondheim (Norway)

    1996-12-31

    This paper describes work aimed at physical and numerical modeling of separation rates of oil/water systems in order to establish better tools for design and operation of offshore operators. This work aims to integrate the chemical and physical phenomena behind coalescence and settling with those of fluid flow in the system, in order to develop tools for design and operational analysis of separation equipment. The work includes the development of a high pressure, bench-scale test rig to perform separation tests on live oil and water samples, and a rationale in the form of a computer code that can be used to interpret the test results and transform them to a form siutable for operational purposes. This involves a formulation of a mathematical description of the chemical and physical mechanisms behind the emulsification and separation process, and to establish a link to the hydrdynamic properties of the separator vessel. The Emucol computer program is used in the analysis. 12 refs., 5 figs.

  1. The Equatorial Ekman Layer

    CERN Document Server

    Marcotte, Florence; Soward, Andrew

    2016-01-01

    The steady incompressible viscous flow in the wide gap between spheres rotating about a common axis at slightly different rates (small Ekman number E) has a long and celebrated history. The problem is relevant to the dynamics of geophysical and planetary core flows, for which, in the case of electrically conducting fluids, the possible operation of a dynamo is of considerable interest. A comprehensive asymptotic study, in the limit E<<1, was undertaken by Stewartson (J. Fluid Mech. 1966, vol. 26, pp. 131-144). The mainstream flow, exterior to the E^{1/2} Ekman layers on the inner/outer boundaries and the shear layer on the inner sphere tangent cylinder C, is geostrophic. Stewartson identified a complicated nested layer structure on C, which comprises relatively thick quasi-geostrophic E^{2/7} (inside C) and E^{1/4} (outside C) layers. They embed a thinner E^{1/3} ageostrophic shear layer (on C), which merges with the inner sphere Ekman layer to form the E^{2/5} Equatorial Ekman layer of axial length E^{...

  2. Fluid physics of a rotating membrane separator

    Science.gov (United States)

    Akonur, Alp

    Rotating membrane separation is a powerful dynamic filtration technique used in separation and filtration of suspensions. Rotating membrane separation is superior compared to the conventional filtration techniques owing to the special character of the flow field, namely the supercritical cylindrical Couette flow, observed in the form of nonwavy and wavy toroidal vortices. The underlying physics are investigated by extending the previous particle image velocity (PIV) measurements performed in a radial-axial plane to a radial-azimuthal plane for nonwavy Taylor Couette flow and wavy cylindrical Couette flow. These measurements are matched to previous measurements to obtain the first time- resolved, three-dimensional, three-component velocity field for cylindrical Couette flow. The nonwavy toroidal vortices of Taylor-Couette flow become stronger with increasing Taylor number. The azimuthal velocity varies axially due to the redistribution of the azimuthal momentum by the vortical motion, which results in a substantial increase in the angular momentum at outflow regions and a decrease at inflow regions. For wavy vortex flow, the waviness of the vortices results in a variation of the azimuthal velocity in any given latitudinal place. Streams of axial flow carry fluid along the length of the annulus winding around the vortices radially from the inner cylinder to the outer cylinder, and azimuthally about one-half wavelength. The azimuthal velocity near the centers of the vortices is similar to the velocity of the traveling azimuthal wave. Large shear stresses occur near the inner and outer cylinders especially at the high Taylor numbers. In the middle of the annulus, the shear stress is substantially less. In filtration flow, where radial and axial flows are imposed on cylindrical Couette flow, simultaneous use of particle image velocimetry (PIV) and particle tracking velocimetry (PTV) provides fluid and particle velocities. Results indicate no major differences in the

  3. The Application of Layer Theory to Design: The Control Layer

    Science.gov (United States)

    Gibbons, Andrew S.; Langton, Matthew B.

    2016-01-01

    A theory of design layers proposed by Gibbons ("An Architectural Approach to Instructional Design." Routledge, New York, 2014) asserts that each layer of an instructional design is related to a body of theory closely associated with the concerns of that particular layer. This study focuses on one layer, the control layer, examining…

  4. Multi-layer coatings

    Energy Technology Data Exchange (ETDEWEB)

    Maghsoodi, Sina; Brophy, Brenor L.; Abrams, Ze' ev R.; Gonsalves, Peter R.

    2016-06-28

    Disclosed herein are coating materials and methods for applying a top-layer coating that is durable, abrasion resistant, highly transparent, hydrophobic, low-friction, moisture-sealing, anti-soiling, and self-cleaning to an existing conventional high temperature anti-reflective coating. The top coat imparts superior durability performance and new properties to the under-laying conventional high temperature anti-reflective coating without reducing the anti-reflectiveness of the coating. Methods and data for optimizing the relative thickness of the under-layer high temperature anti-reflective coating and the top-layer thickness for optimizing optical performance are also disclosed.

  5. Catalytic Polymer Multilayer Shell Motors for Separation of Organics.

    Science.gov (United States)

    Lin, Zhihua; Wu, Zhiguang; Lin, Xiankun; He, Qiang

    2016-01-26

    A catalytic polymer multilayer shell motor has been developed, which effects fast motion-based separation of charged organics in water. The shell motors are fabricated by sputtering platinum onto the exposed surface of silica templates embedded in Parafilm, followed by layer-by-layer assembly of polyelectrolyte multilayers to the templates. The catalytic shell motors display high bubble propulsion with speeds of up to 260 μm s(-1) (13 body lengths per second). Moreover, the polyelectrolyte multilayers assembled at high pH (pH>9.0) adsorb approximately 89% of dye molecules from water, owing to the electrostatic interaction between the positively charged polymers and the anionic dye molecules, and subsequently release them at neutral pH in a microfluidic device. The efficient propulsion coupled with the effective adsorption behavior of the catalytic shell motors in a microfluidic device results in accelerated separation of organics in water and thus holds considerable promise for water analysis.

  6. Application of 1H NMR spectroscopy method for determination of characteristics of thin layers of water adsorbed on the surface of dispersed and porous adsorbents.

    Science.gov (United States)

    Turov, V V; Leboda, R

    1999-02-01

    The paper presents 1H NMR spectroscopy as a perspective method of the studies of the characteristics of water boundary layers in the hydrated powders and aqueous dispergated suspensions of the adsorbents. The method involves measurements of temperature dependence proton signals intensity in the adsorbed water at temperatures lower than 273 K. Free energy of water molecules at the adsorbent/water interface is diminished due to the adsorption interactions causing the water dosed to the adsorbent surface freezes at T water can be determined from the intensity of the water signal of 1H NMR during the freezing-thawing process. Due to a disturbing action of the adsorbent surface, water occurs in the quasi-liquid state. As a result, it is observed in the 1H NMR spectra as a relatively narrow signal. The signal of ice is not registered due to great differences in the transverse relaxation times of the adsorbed water and ice. The method of measuring the free surface energy of the adsorbents from the temperature dependence of the signal intensity of non-freezing water is based on the fact that the temperature of water freezing decreases by the quantity which depends on the surface energy and the distance of the adsorbed molecules from the solid surface. The water at the interface freezes when the free energies of the adsorbed water and ice are equal. To illustrate the applicability of the method under consideration the series of adsorption systems in which the absorbents used differed in the surface chemistry and porous structure. In particular, the behaviour of water on the surface of the following adsorbents is discussed: non-porous and porous silica (aerosils, silica gels); chemically and physically modified non-porous and porous silica (silanization, carbonization, biopolymer deposition); and pyrogeneous Al2O3 and aluminasilicas. The effect of preliminary treatment of the adsorbent (thermal, high pressure, wetting with polar and non-polar solvents) on the characteristics

  7. Hyperthin Organic Membranes for Gas Separations

    Science.gov (United States)

    Wang, Minghui

    Gas separation is practically important in many aspects, e.g., clean energy production and global warming prevention. Compared to other separation technologies like cryogenic distillation and pressure swing adsorption, membrane separation is considered to be more energy efficient. For practical purposes, the ultimate goal is to construct membranes producing high flux and high gas permeation selectivity at the same time. Based on the inverse relationship between flux and membrane thickness, it is clear that fabricating highly selective membranes as thin as possible could increase the flux through the membrane without sacrificing selectivity. But it has proven to be challenging to manufacture selective membranes in the hyperthin (poly(1-trimethylsilyl-1-propyne) (PTMSP), using Langmuir-Blodgett (LB) and Layer-by-Layer (LbL) deposition methods. A "gluing" strategy has been successfully introduced into LB films by our laboratory recently, in which LB monolayers are ionically crosslinked with polyelectrolytes. This success stimulated the pursuance of LB films with improved gas separation properties by: (i) examining calix[n]arene-based surfactants with different sizes (ii) using polymeric surfactants as LB forming materials, and (iii) optimizing the condition of the subphase containing polyelectrolytes. Both a strong polyelectrolyte poly(4-styrene sulfonate) (PSS) and a weak polyelectrolyte poly(acrylic acid) (PAA) were used to create glued LB bilayers. The gas permeation through PSS or PAA-glued LB bilayers made of calix[n]arenes was found to be dominated by solution-diffusion rather than molecular-sieving mechanism. The porous nature of calix[n]arene-based surfactants also turned out to be unnecessary for constructing LB films with high gas selectivities, because a single PAA-glued LB bilayer made of a nonporous polymeric surfactant (ca. 7 nm) was found to exhibit a much higher H2/CO2 selectivity (200), which reached the "upper bound". The key factors that are likely

  8. Addressing Ozone Layer Depletion

    Science.gov (United States)

    Access information on EPA's efforts to address ozone layer depletion through regulations, collaborations with stakeholders, international treaties, partnerships with the private sector, and enforcement actions under Title VI of the Clean Air Act.

  9. Numerical study on the suppression of shock induced separation on the non-adiabatic wall

    Science.gov (United States)

    Lee, Doug-Bong

    2000-12-01

    A numerical model is constructed to simulate the interaction of supersonic ( M=2.4) oblique shock wave / turbulent boundary layer on a strongly heated wall. The heated wall temperature is two times higher than the adiabatic wall temperature and the shock wave is strong enough to induce boundary layer separation. The turbulence model is Spalart-Allmaras model. The comparison of the wall pressure distribution with the experimental data ensures the validity of this numerical model. The effect of strong wall heating enlarges the separation region upstream and downstream. In order to eliminate the separation, wall bleeding is applied at the shock foot position. As a result of the parametric study, the best position of the bleeding slot is selected. The position of the bleeding is very important for the separation suppression. If the bleeding is applied upstream of shock foot, then separation reoccurs after the bleeding slot. If the bleeding is applied downstream of shock foot, the upstream boundary layer is little influenced and still separated. The bleeding vent width is about same as the upstream boundary layer thickness and suction mass flow is 20 to 80 % of the flow rate in the upstream boundary layer. The bleeding mass flow rate is very sensitive to the bleeding vent position if we fix the vent outlet pressure. The final configuration of the shock reflection pattern approaches to the non-viscous value when wall bleeding is applied at the shock impinging point.

  10. Membrane manufacture for peptide separations

    KAUST Repository

    Kim, Dooli

    2016-06-07

    Nanostructured polymeric membranes are key tools in biomedical applications such as hemodialysis, protein separations, in the food industry, and drinking water supply from seawater. Despite of the success in different separation processes, membrane manufacture itself is at risk, since the most used solvents are about to be banned in many countries due to environmental and health issues. We propose for the first time the preparation of polyethersulfone membranes based on dissolution in the ionic liquid 1-ethyl-3-methylimidazolium dimethylphosphate ([EMIM]DEP). We obtained a series of membranes tailored for separation of solutes with molecular weight of 30, 5, 1.3, and 1.25 kg mol-1 with respective water permeances of 140, 65, 30 and 20 Lm-2h-1bar-1. We demonstrate their superior efficiency in the separation of complex mixtures of peptides with molecular weights in the range of 800 to 3500 gmol-1. Furthermore, the thermodynamics and kinetics of phase separation leading to the pore formation in the membranes were investigated. The rheology of the solutions and the morphology of the prepared membranes were examed and compared to those of polyethersulfone in organic solvents currently used for membrane manufacture.

  11. Charged Polymer-Coated Separators by Atmospheric Plasma-Induced Grafting for Lithium-Ion Batteries.

    Science.gov (United States)

    Han, Mina; Kim, Dong-Won; Kim, Yeong-Cheol

    2016-10-05

    A simple and fast method of atmospheric plasma-induced grafting was applied over a polyethylene membrane to enhance its performance as a separator for lithium-ion batteries. The process of grafting has formed a thin, durable, and uniform layer on the surface of the porous membrane. The charges of grafted polymers affected the performance of batteries in many ways besides the change of hydrophilicity. Negative charges in polymers improve the capacity retention of batteries and the uniformity of the SEI layer. On the other hand, the electrostatic attraction between different charges contributed to small increases of thermal stability and mechanical strength of separators. Polyampholyte was grafted by using the mixtures of monomers, and the composition of the grafted layer was optimized. The formation of stable uniform SEI layers and the marked improvement in capacity retention were observed in the full cell tests of the lithium battery with the polyampholyte-grafted separators when the polyampholyte has a negative net charge.

  12. Structured luminescence conversion layer

    Science.gov (United States)

    Berben, Dirk; Antoniadis, Homer; Jermann, Frank; Krummacher, Benjamin Claus; Von Malm, Norwin; Zachau, Martin

    2012-12-11

    An apparatus device such as a light source is disclosed which has an OLED device and a structured luminescence conversion layer deposited on the substrate or transparent electrode of said OLED device and on the exterior of said OLED device. The structured luminescence conversion layer contains regions such as color-changing and non-color-changing regions with particular shapes arranged in a particular pattern.

  13. Layered circle packings

    Directory of Open Access Journals (Sweden)

    David Dennis

    2005-01-01

    Full Text Available Given a bounded sequence of integers {d0,d1,d2,…}, 6≤dn≤M, there is an associated abstract triangulation created by building up layers of vertices so that vertices on the nth layer have degree dn. This triangulation can be realized via a circle packing which fills either the Euclidean or the hyperbolic plane. We give necessary and sufficient conditions to determine the type of the packing given the defining sequence {dn}.

  14. The Signal Space Separation method

    CERN Document Server

    Taulu, S; Simola, J; Taulu, Samu; Kajola, Matti; Simola, Juha

    2004-01-01

    Multichannel measurement with hundreds of channels essentially covers all measurable degrees of freedom of a curl and source free vector field, like the magnetic field in a volume free of current sources (e.g. in magnetoencephalography, MEG). A functional expansion solution of Laplace's equation enables one to separate signals arising from the sphere enclosing the interesting sources, e.g. the currents in the brain, from the rest of the signals. The signal space separation (SSS) is accomplished by calculating individual basis vectors for each term of the functional expansion solution to create a signal basis covering all measurable signal vectors. Any signal vector has a unique SSS decomposition with separate coefficients for the interesting signals and signals coming from outside the interesting volume. Thus, SSS basis provides an elegant method to remove external disturbances, and to transform the interesting signals to virtual sensor configurations. SSS can also be used in compensating the movements of the...

  15. Rare Earth Separation in China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    During the last decade, China rare earth (RE) industry has made significant progress and become one of the most important producers in the world. In this paper, the recent developments in both fundamental research and industrial application are briefly reviewed: (1) the development and application of Theory of Countercurrent Extraction, (2) the novel solvent extraction process and its application in industry for separating heavy rare earth elements (Tm, Yb, Lu), yttrium (Y), and scandium (Sc), (3) the on-line analysis and automatic control of countercurrent extraction, (4) the eco-friendly process for RE/Th separation of bastnasite in Sichuan Province and electrochemical process for Eu/RE separation, and (5) the optimized flowcharts for typical rare earth minerals in China.

  16. Source Separation with One Ear: Proposition for an Anthropomorphic Approach

    Directory of Open Access Journals (Sweden)

    Ramin Pichevar

    2005-06-01

    Full Text Available We present an example of an anthropomorphic approach, in which auditory-based cues are combined with temporal correlation to implement a source separation system. The auditory features are based on spectral amplitude modulation and energy information obtained through 256 cochlear filters. Segmentation and binding of auditory objects are performed with a two-layered spiking neural network. The first layer performs the segmentation of the auditory images into objects, while the second layer binds the auditory objects belonging to the same source. The binding is further used to generate a mask (binary gain to suppress the undesired sources from the original signal. Results are presented for a double-voiced (2 speakers speech segment and for sentences corrupted with different noise sources. Comparative results are also given using PESQ (perceptual evaluation of speech quality scores. The spiking neural network is fully adaptive and unsupervised.

  17. Thermographic Detection of separated Flow

    Science.gov (United States)

    Dollinger, C.; Balaresque, N.; Schaffarczyk, A. P.; Fischer, A.

    2016-09-01

    Thermographic wind tunnel measurements, both on a cylinder as well as on a 2D airfoil, were performed at various Reynolds numbers in order to evaluate the possibility of detecting and visualizing separated flow areas. A new approach by acquiring a series of thermographic images and applying a spatial-temporal statistical analysis allows improving both the resolution and the information content of the thermographic images. Separated flow regions become visible and laminar/turbulent transitions can be detected more accurately. The knowledge about possibly present stall cells can be used to confirm two-dimensional flow conditions and support the development of more effective and silent rotorblades.

  18. Separation processes, I: Azeotropic rectification

    Directory of Open Access Journals (Sweden)

    Milojević Svetomir

    2005-01-01

    Full Text Available In a series of two articles, the problems of azeotrope separation (part I and the design of separation units (part II were analyzed. The basic definition and equations of vapour-liquid equilibria for ideal and non-ideal systems, the importance of the activity coefficient calculation necessary for the analysis of non-ideal equilibrium systems, as well as theoretical aspects of azeotrope rectification and the determination of the optimal third component (modifier or azeotrope agent are presented in the first part.

  19. Separable metrics and radiating stars

    Indian Academy of Sciences (India)

    G Z ABEBE; S D MAHARAJ

    2017-01-01

    We study the junction condition relating the pressure to heat flux at the boundary of an accelerating and expanding spherically symmetric radiating star. We transform the junction condition to an ordinary differential equation by making a separability assumption on the metric functions in the space–time variables. The condition of separability on the metric functions yields several new exact solutions. A class of shear-free models is found which contains a linear equation of state and generalizes a previously obtained model. Four new shearing models are obtained; all the gravitational potentials can be written explicitly. A brief physical analysis indicates that the matter variables are well behaved.

  20. SOFC and Gas Separation Membranes

    DEFF Research Database (Denmark)

    Hagen, Anke; Hendriksen, Peter Vang; Søgaard, Martin

    2009-01-01

    from air. Subsequent separation and sequestration of CO2 is therefore easier on a SOFC plant than on conventional power plants based on combustion. Oxide ion conducting materials may be used for gas separation purposes with close to 100 % selectivity. They typically work in the same temperature range...... as SOFCs. Such membranes can potentially be used in Oxyfuel processes as well as in IGCC (Integrated Gasification Combined Cycle) power plants for supply of process oxygen, which may reduce cost of carbon capture and storage as dilution of the flue gas with nitrogen is avoided. Both technologies are very...

  1. Separation and confirmation of showers

    Science.gov (United States)

    Neslušan, L.; Hajduková, M.

    2017-01-01

    Aims: Using IAU MDC photographic, IAU MDC CAMS video, SonotaCo video, and EDMOND video databases, we aim to separate all provable annual meteor showers from each of these databases. We intend to reveal the problems inherent in this procedure and answer the question whether the databases are complete and the methods of separation used are reliable. We aim to evaluate the statistical significance of each separated shower. In this respect, we intend to give a list of reliably separated showers rather than a list of the maximum possible number of showers. Methods: To separate the showers, we simultaneously used two methods. The use of two methods enables us to compare their results, and this can indicate the reliability of the methods. To evaluate the statistical significance, we suggest a new method based on the ideas of the break-point method. Results: We give a compilation of the showers from all four databases using both methods. Using the first (second) method, we separated 107 (133) showers, which are in at least one of the databases used. These relatively low numbers are a consequence of discarding any candidate shower with a poor statistical significance. Most of the separated showers were identified as meteor showers from the IAU MDC list of all showers. Many of them were identified as several of the showers in the list. This proves that many showers have been named multiple times with different names. Conclusions: At present, a prevailing share of existing annual showers can be found in the data and confirmed when we use a combination of results from large databases. However, to gain a complete list of showers, we need more-complete meteor databases than the most extensive databases currently are. We also still need a more sophisticated method to separate showers and evaluate their statistical significance. Tables A.1 and A.2 are also available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc

  2. Barriers in Concurrent Separation Logic

    Science.gov (United States)

    Hobor, Aquinas; Gherghina, Cristian

    We develop and prove sound a concurrent separation logic for Pthreads-style barriers. Although Pthreads barriers are widely used in systems, and separation logic is widely used for verification, there has not been any effort to combine the two. Unlike locks and critical sections, Pthreads barriers enable simultaneous resource redistribution between multiple threads and are inherently stateful, leading to significant complications in the design of the logic and its soundness proof. We show how our logic can be applied to a specific example program in a modular way. Our proofs are machine-checked in Coq.

  3. Convolutive Blind Source Separation Methods

    DEFF Research Database (Denmark)

    Pedersen, Michael Syskind; Larsen, Jan; Kjems, Ulrik

    2008-01-01

    During the past decades, much attention has been given to the separation of mixed sources, in particular for the blind case where both the sources and the mixing process are unknown and only recordings of the mixtures are available. In several situations it is desirable to recover all sources from....... This may help practitioners and researchers new to the area of convolutive source separation obtain a complete overview of the field. Hopefully those with more experience in the field can identify useful tools, or find inspiration for new algorithms....

  4. Level measurement and control strategies for subsea separators

    Science.gov (United States)

    Hjertaker, Bjorn T.; Johansen, Geir A.; Jackson, Peter

    2001-07-01

    Level monitoring instrumentation is an essential part of hydrocarbon processing facilities, and has, together with separator technology, been widely addressed over the last decade. Key issues are production capacity, product enhancement, and well-flow control. The reliability and accuracy of the level instrumentation, and its ability to monitor all the interface layers of the separator, including the thickness of the foam and the oil-water emulsion, are particularly important when considering the level instrumentation as the main sensing element in the automatic control of the separator vessel. Lately, industry focus has been placed on optimal automatic control to improve the quality of the production output, and to minimize the use of expensive and environmentally undesirable separation enhancing chemicals. Recent developments in hydrocarbon production include subsea separation stations, where the constraints placed on the reliability and accuracy of the level instrumentation are especially demanding. This paper presents level interface monitoring developments based on electrical, ultrasonic, thermal, and nucleonic physical principles for three-phase hydrocarbon separators, and introduces the notion of tomometry, meaning multi-point cross-sectional metering aiming to acquire information on the cross-sectional flow-component distribution in the process vessel intended for control purposes.

  5. Roughness induced flow separation in adverse pressure gradient

    Science.gov (United States)

    Joo, Jongwook; Emory, Mike; Bose, Sanjeeb; Medic, Gorazd; Sharma, Om

    2016-11-01

    Surface roughness does not only increase turbulent mixing, but also thickens boundary-layers, making flows more susceptible to separation. Detailed flow physics related to the separation is not understood well. Bammert and Milsch (1972) demonstrates a clear example of surface roughness induced separation under adverse pressure gradient. In the study, compressor cascades with NACA 65 airfoils are systematically roughened and the flow over suction surface gradually separates early as roughness increases. A set of Large-Eddy Simulations (LES) over the Bammert's case is investigated, since RANS simulations using roughness models suffer from capturing the separation. In the current study, surface roughness is represented in two different approaches; 1) Realistic rough surface represented by stochastically distributed hills and valleys are gridded and solved with unstructured finite volume method, 2) Using block-structured grid, surface roughness is gridded as a staggered array of 3D rectangles, in a similar way of the previous study for roughened low pressure turbine (GT2016-57912). The current LES's capture rich features of the flow phenomena, which will bring comprehensive understanding of the roughness induced separation. This collaboration is made through 2016 CTR Summer Program.

  6. Strong Effect of Azodye Layer Thickness on RM-Stabilized Photoalignment

    Science.gov (United States)

    2017-05-21

    Polymerizable azodyes[3] as well as passivation of the azodye film by spin -coating with a layer of reactive mesogen[4] are currently proposed solutions...either 0.1% or 2% BY by weight in DMF were spin coated onto glass substrates at 1500 rpm for 30 s to obtain a uniform BY film. After spin coating...layer with the desired alignment and then creating a surface localized polymer layer on top of the photoalignment layer through phase separation

  7. Magnetic separation apparatus and methods

    NARCIS (Netherlands)

    Tibbe, Arjan; Scholtens, Tycho M.; Terstappen, Leon W.M.M.

    2010-01-01

    Apparatuses and methods for separating, immobilizing, and quantifying biological substances from within a fluid medium. Biological substances are observed by employing a vessel (6) having a chamber therein, the vessel comprising a transparent collection wall (5). A high internal gradient magnetic ca

  8. Separating Device for solid Particles

    NARCIS (Netherlands)

    De Jong, T.P.R.; Kattentidt, H.U.R.; Schokker, E.A.

    2001-01-01

    The invention relates to a separating device for solid fragments, comprising a conveyor belt for supplying the fragments, at least one sensor for detecting the fragments, and an ejector for dislodging the fragments from the belt. The ejector is embodied as mechanical impulse-transmitting organ opera

  9. Operation of Electromagnetic Isotope Separator

    Institute of Scientific and Technical Information of China (English)

    MI; Ya-jing

    2015-01-01

    In 2015,we mainly completed the installation of the electromagnetic isotope separator comprehensive technical transformation projects,including the work of installation,debugging,commissioning and acceptance.In June 30,2015,according to the schedule requirements,the project

  10. 33rd Actinide Separations Conference

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, L M; Wilk, P A

    2009-05-04

    Welcome to the 33rd Actinide Separations Conference hosted this year by the Lawrence Livermore National Laboratory. This annual conference is centered on the idea of networking and communication with scientists from throughout the United States, Britain, France and Japan who have expertise in nuclear material processing. This conference forum provides an excellent opportunity for bringing together experts in the fields of chemistry, nuclear and chemical engineering, and actinide processing to present and discuss experiences, research results, testing and application of actinide separation processes. The exchange of information that will take place between you, and other subject matter experts from around the nation and across the international boundaries, is a critical tool to assist in solving both national and international problems associated with the processing of nuclear materials used for both defense and energy purposes, as well as for the safe disposition of excess nuclear material. Granlibakken is a dedicated conference facility and training campus that is set up to provide the venue that supports communication between scientists and engineers attending the 33rd Actinide Separations Conference. We believe that you will find that Granlibakken and the Lake Tahoe views provide an atmosphere that is stimulating for fruitful discussions between participants from both government and private industry. We thank the Lawrence Livermore National Laboratory and the United States Department of Energy for their support of this conference. We especially thank you, the participants and subject matter experts, for your involvement in the 33rd Actinide Separations Conference.

  11. Working inside an electrostatic separator

    CERN Multimedia

    1980-01-01

    This type of separators with electrodes of a length of 2 m and a field of 100 kV/cm were still in use for secondary beams in the East Hall at the PS. Michel Zahnd is on foreground, left, and Pierre Simon on background, right.

  12. Development of Separator for Soybeans

    NARCIS (Netherlands)

    Vries, de H.C.P.; Rijpma, P.J.; Owaa, J.S.E.

    1997-01-01

    A simple and effective separator for soybeans was developed for small-scale farmers in Uganda, to clean the seeds from foreign material, chaff, broken beans etc. as demanded by local and world markets. It will help to avoid losses during post-harvest time and to reduce human drudgery of cleaning the

  13. Separation technology 2005; Separasjonsteknologi 2005

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    The conference comprises 13 presentations on the topics of separation technology aspects with emphasis on technology assessment. Some topics of particular interest are emulsion stabilization, sand technology and handling, water handling and reservoir injection, technical equipment and compression and pressure aspects.

  14. Separating proteins with activated carbon.

    Science.gov (United States)

    Stone, Matthew T; Kozlov, Mikhail

    2014-07-15

    Activated carbon is applied to separate proteins based on differences in their size and effective charge. Three guidelines are suggested for the efficient separation of proteins with activated carbon. (1) Activated carbon can be used to efficiently remove smaller proteinaceous impurities from larger proteins. (2) Smaller proteinaceous impurities are most efficiently removed at a solution pH close to the impurity's isoelectric point, where they have a minimal effective charge. (3) The most efficient recovery of a small protein from activated carbon occurs at a solution pH further away from the protein's isoelectric point, where it is strongly charged. Studies measuring the binding capacities of individual polymers and proteins were used to develop these three guidelines, and they were then applied to the separation of several different protein mixtures. The ability of activated carbon to separate proteins was demonstrated to be broadly applicable with three different types of activated carbon by both static treatment and by flowing through a packed column of activated carbon.

  15. Gas Separations using Ceramic Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Paul KT Liu

    2005-01-13

    This project has been oriented toward the development of a commercially viable ceramic membrane for high temperature gas separations. A technically and commercially viable high temperature gas separation membrane and process has been developed under this project. The lab and field tests have demonstrated the operational stability, both performance and material, of the gas separation thin film, deposited upon the ceramic membrane developed. This performance reliability is built upon the ceramic membrane developed under this project as a substrate for elevated temperature operation. A comprehensive product development approach has been taken to produce an economically viable ceramic substrate, gas selective thin film and the module required to house the innovative membranes for the elevated temperature operation. Field tests have been performed to demonstrate the technical and commercial viability for (i) energy and water recovery from boiler flue gases, and (ii) hydrogen recovery from refinery waste streams using the membrane/module product developed under this project. Active commercializations effort teaming with key industrial OEMs and end users is currently underway for these applications. In addition, the gas separation membrane developed under this project has demonstrated its economical viability for the CO2 removal from subquality natural gas and landfill gas, although performance stability at the elevated temperature remains to be confirmed in the field.

  16. Black layers on historical architecture.

    Science.gov (United States)

    Toniolo, Lucia; Zerbi, Carlotta M; Bugini, Roberto

    2009-03-01

    separation is particularly evident in 'recent' crust, where the sulphation process is more active. Black compact deposits show a higher porosity than black crusts because gypsum is not coming from the chemical corrosion of the substrate but from outside; actually, in the former case, the substrate is sound. Encrustations show a highly regular crystal organisation of gypsum (close packed tabular crystals) that cannot be traced back to casual atmospheric deposit or to corrosion of the substrate but rather to the crystallisation of a solution coming from an external source. Also in this case, the marble is sound; evidence of the effect of some protection treatment is pointed out. In spite of the apparent similarity of the examined samples, analytical results have evidenced three main types of black crusts: black crust with decayed substrate, compact deposit and black encrustation showing a sound substrate underneath. Experimental evidence of calcite grains sulphation in progress, taking place according to a model recently proposed, has been observed. Sulphation process is prevented where particular conservation treatments had been applied in the past. New experimental studies can be focussed to understand the specific conditions (measurements of micro-climatic and thermodynamic parameters) and mechanisms for black crusts formation in situ. The problem of the kinetic of the sulphation process of marble, the assessment of black layers formation in the case of different carbonate stone materials and the study of acid attack in presence of surface protecting layers deserve further investigation.

  17. Magnetic separation for environmental remediation

    Energy Technology Data Exchange (ETDEWEB)

    Schake, A.R.; Avens, L.R.; Hill, D.D.; Padilla, D.D.; Prenger, F.C.; Romero, D.A.; Worl, L.A. [Los Alamos National Lab., NM (United States); Tolt, T.L. [Lockheed Environmental Systems and Technologies Co., Las Vegas, NV (United States)

    1994-11-01

    High Gradient Magnetic Separation (HGMS) is a form of magnetic separation used to separate solids from other solids, liquids or gases. HGMS uses large magnetic field gradients to separate ferromagnetic and paramagnetic particles from diamagnetic host materials. The technology relies only on physical properties, and therefore separations can be achieved while producing a minimum of secondary waste. Actinide and fission product wastes within the DOE weapons complex pose challenging problems for environmental remediation. Because the majority of actinide complexes and many fission products are paramagnetic, while most host materials are diamagnetic, HGMS can be used to concentrate the contaminants into a low volume waste stream. The authors are currently developing HGMS for applications to soil decontamination, liquid waste treatment, underground storage tank waste treatment, and actinide chemical processing residue concentration. Application of HGMS usually involves passing a slurry of the contaminated mixture through a magnetized volume. Field gradients are produced in the magnetized volume by a ferromagnetic matrix material, such as steel wool, expanded metal, iron shot, or nickel foam. The matrix fibers become trapping sites for ferromagnetic and paramagnetic particles in the host material. The particles with a positive susceptibility are attracted toward an increasing magnetic field gradient and can be extracted from diamagnetic particles, which react in the opposite direction, moving away from the areas of high field gradients. The extracted paramagnetic contaminants are flushed from the matrix fibers when the magnetic field is reduced to zero or when the matrix canister is removed from the magnetic field. Results are discussed for the removal of uranium trioxide from water, PuO{sub 2}, U, and Pu from various soils (Fernald, Nevada Test Site), and the waste water treatment of Pu and Am isotopes using HGMS.

  18. A self-cleaning underwater superoleophobic mesh for oil-water separation

    KAUST Repository

    Zhang, Lianbin

    2013-07-31

    Oil-water separation has recently become a global challenging task because of the frequent occurrence of oil spill accidents due to the offshore oil production and transportation, and there is an increasing demand for the development of effective and inexpensive approaches for the cleaning-up of the oily pollution in water system. In this study, a self-cleaning underwater superoleophobic mesh that can be used for oil-water separation is prepared by the layer-by-layer (LbL) assembly of sodium silicate and TiO2 nanoparticles on the stainless steel mesh. The integration of the self-cleaning property into the all-inorganic separation mesh by using TiO2 enables the convenient removal of the contaminants by ultraviolet (UV) illumination, and allows for the facile recovery of the separation ability of the contaminated mesh, making it promising for practial oil-water separation applications.

  19. The Dynamics of Controlled Flow Separation within a Diverter Duct Diffuser

    Science.gov (United States)

    Peterson, C. J.; Vukasinovic, B.; Glezer, A.

    2016-11-01

    The evolution and receptivity to fluidic actuation of the flow separation within a rectangular, constant-width, diffuser that is branched off of a primary channel is investigated experimentally at speeds up to M = 0.4. The coupling between the diffuser's adverse pressure gradient and the internal separation that constricts nearly half of the flow passage through the duct is controlled using a spanwise array of fluidic actuators on the surface upstream of the diffuser's inlet plane. The dynamics of the separating surface vorticity layer in the absence and presence of actuation are investigated using high-speed particle image velocimetry combined with surface pressure measurements and total pressure distributions at the primary channel's exit plane. It is shown that the actuation significantly alters the incipient dynamics of the separating vorticity layer as the characteristic cross stream scales of the boundary layer upstream of separation and of the ensuing vorticity concentrations within the separated flow increase progressively with actuation level. It is argued that the dissipative (high frequency) actuation alters the balance between large- and small-scale motions near separation by intensifying the large-scale motions and limiting the small-scale dynamics. Controlling separation within the diffuser duct also has a profound effect on the global flow. In the presence of actuation, the mass flow rate in the primary duct increases 10% while the fraction of the diverted mass flow rate in the diffuser increases by more than 45% at 0.7% actuation mass fraction. Supported by the Boeing Company.

  20. Superfluid Boundary Layer

    Science.gov (United States)

    Stagg, G. W.; Parker, N. G.; Barenghi, C. F.

    2017-03-01

    We model the superfluid flow of liquid helium over the rough surface of a wire (used to experimentally generate turbulence) profiled by atomic force microscopy. Numerical simulations of the Gross-Pitaevskii equation reveal that the sharpest features in the surface induce vortex nucleation both intrinsically (due to the raised local fluid velocity) and extrinsically (providing pinning sites to vortex lines aligned with the flow). Vortex interactions and reconnections contribute to form a dense turbulent layer of vortices with a nonclassical average velocity profile which continually sheds small vortex rings into the bulk. We characterize this layer for various imposed flows. As boundary layers conventionally arise from viscous forces, this result opens up new insight into the nature of superflows.

  1. Layered Systems Engineering Engines

    Science.gov (United States)

    Breidenthal, Julian C.; Overman, Marvin J.

    2009-01-01

    A notation is described for depicting the relationships between multiple, contemporaneous systems engineering efforts undertaken within a multi-layer system-of-systems hierarchy. We combined the concepts of remoteness of activity from the end customer, depiction of activity on a timeline, and data flow to create a new kind of diagram which we call a "Layered Vee Diagram." This notation is an advance over previous notations because it is able to be simultaneously precise about activity, level of granularity, product exchanges, and timing; these advances provide systems engineering managers a significantly improved ability to express and understand the relationships between many systems engineering efforts. Using the new notation, we obtain a key insight into the relationship between project duration and the strategy selected for chaining the systems engineering effort between layers, as well as insights into the costs, opportunities, and risks associated with alternate chaining strategies.

  2. Teaching Separations: Why, What, When, and How?

    Science.gov (United States)

    Wankat, Phillip C.

    2001-01-01

    Describes how and when to teach separation science to chemical engineering students. Separation science is important for industrial businesses involving the manufacture of adsorption systems, distillation columns, extractors, and other separation equipment and techniques. (Contains 13 references.) (YDS)

  3. The effects of forcing on a single stream shear layer and its parent boundary layer

    Science.gov (United States)

    Haw, Richard C.; Foss, John F.

    1990-01-01

    Forcing and its effect on fluid flows has become an accepted tool in the study and control of flow systems. It has been used both as a diagnostic tool, to explore the development and interaction of coherent structures, and as a method of controlling the behavior of the flow. A number of forcing methods have been used in order to provide a perturbation to the flow; among these are the use of an oscillating trailing edge, acoustically driven slots, external acoustic forcing, and mechanical piston methods. The effect of a planar mechanical piston forcing on a single stream shear layer is presented; it can be noted that this is one of the lesser studied free shear layers. The single stream shear layer can be characterized by its primary flow velocity scale and the thickness of the separating boundary layer. The velocity scale is constant over the length of the flow field; theta (x) can be used as a width scale to characterize the unforced shear layer. In the case of the forced shear layer the velocity field is a function of phase time and definition of a width measure becomes somewhat problematic.

  4. Reinforcing the mineral layer

    Energy Technology Data Exchange (ETDEWEB)

    Pishchulin, V.V.; Kuntsevich, V.I.; Seryy, A.M.; Shirokov, A.P.

    1980-05-15

    A way of reinforcing the mineral layer includes drilling holes and putting in anchors that are longer than the width of the layer strip being extracted. It also includes shortening the anchors as the strip is mined and reinforcing the remaining part of the anchor in the mouth of the hole. To increase the productivity and safety of the work, the anchors are shortened by cutting them as the strip is mined and are reinforced through wedging. The device for doing this has auxilliary lengthwise grooves in the shaft located along its length at an interval equal to the width of the band being extracted.

  5. Selective Photo-Initiated Electrophoretic Separator Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Physical Optics Corporation (POC) proposes to develop a Selective Photoinitiated Electrophoretic Separator (SPIES) System to address NASA's volatile gas separation...

  6. Field-induced layer formation in dipolar nanofilms.

    Science.gov (United States)

    Jordanovic, Jelena; Klapp, Sabine H L

    2008-07-18

    Using molecular dynamics simulations, we demonstrate that the layering of confined colloidal particles with dipolar interactions, such as ferrofluids, in slablike geometries can be controlled by homogeneous external fields. For suitable surface separations, strong fields directed perpendicular to the film plane do not only align the particles but create additional layers in the system. The reverse effect occurs with an in-plane field which can induce a collapse of layers. Both effects are accompanied by pronounced particle rearrangements in lateral directions. Our simulation results are consistent with recent experiments of ferrofluids at surfaces.

  7. Measurement of a thin layers thickness using independent component analysis of ground penetrating radar data

    Institute of Scientific and Technical Information of China (English)

    LI Xiang-tang; ZHANG Xiao-ning; WANG Duan-yi

    2008-01-01

    To detect overlapped echoes due to the thin pavement layers, we present a thickness measurement approach for the very thin layer of pavement structures. The term "thin" is relative to the incident wavelength or pulse. By means of independent component analysis of noisy signals received by a single radar sensor, the over-lapped echoes can be successfully separated. Once the echoes from the top and bottom side of a thin layer have been separated, the time delay and the layer thickness determination follow immediately. Results of the simula-tion and real data re fy the feasibility of the presented method.

  8. Fragment separator momentum compression schemes

    Energy Technology Data Exchange (ETDEWEB)

    Bandura, Laura, E-mail: bandura@anl.gov [Facility for Rare Isotope Beams (FRIB), 1 Cyclotron, East Lansing, MI 48824-1321 (United States); National Superconducting Cyclotron Lab, Michigan State University, 1 Cyclotron, East Lansing, MI 48824-1321 (United States); Erdelyi, Bela [Argonne National Laboratory, Argonne, IL 60439 (United States); Northern Illinois University, DeKalb, IL 60115 (United States); Hausmann, Marc [Facility for Rare Isotope Beams (FRIB), 1 Cyclotron, East Lansing, MI 48824-1321 (United States); Kubo, Toshiyuki [RIKEN Nishina Center, RIKEN, Wako (Japan); Nolen, Jerry [Argonne National Laboratory, Argonne, IL 60439 (United States); Portillo, Mauricio [Facility for Rare Isotope Beams (FRIB), 1 Cyclotron, East Lansing, MI 48824-1321 (United States); Sherrill, Bradley M. [National Superconducting Cyclotron Lab, Michigan State University, 1 Cyclotron, East Lansing, MI 48824-1321 (United States)

    2011-07-21

    We present a scheme to use a fragment separator and profiled energy degraders to transfer longitudinal phase space into transverse phase space while maintaining achromatic beam transport. The first order beam optics theory of the method is presented and the consequent enlargement of the transverse phase space is discussed. An interesting consequence of the technique is that the first order mass resolving power of the system is determined by the first dispersive section up to the energy degrader, independent of whether or not momentum compression is used. The fragment separator at the Facility for Rare Isotope Beams is a specific application of this technique and is described along with simulations by the code COSY INFINITY.

  9. Fragment separator momentum compression schemes.

    Energy Technology Data Exchange (ETDEWEB)

    Bandura, L.; Erdelyi, B.; Hausmann, M.; Kubo, T.; Nolen, J.; Portillo, M.; Sherrill, B.M. (Physics); (MSU); (Northern Illinois Univ.); (RIKEN)

    2011-07-21

    We present a scheme to use a fragment separator and profiled energy degraders to transfer longitudinal phase space into transverse phase space while maintaining achromatic beam transport. The first order beam optics theory of the method is presented and the consequent enlargement of the transverse phase space is discussed. An interesting consequence of the technique is that the first order mass resolving power of the system is determined by the first dispersive section up to the energy degrader, independent of whether or not momentum compression is used. The fragment separator at the Facility for Rare Isotope Beams is a specific application of this technique and is described along with simulations by the code COSY INFINITY.

  10. Causal and causally separable processes

    Science.gov (United States)

    Oreshkov, Ognyan; Giarmatzi, Christina

    2016-09-01

    The idea that events are equipped with a partial causal order is central to our understanding of physics in the tested regimes: given two pointlike events A and B, either A is in the causal past of B, B is in the causal past of A, or A and B are space-like separated. Operationally, the meaning of these order relations corresponds to constraints on the possible correlations between experiments performed in the vicinities of the respective events: if A is in the causal past of B, an experimenter at A could signal to an experimenter at B but not the other way around, while if A and B are space-like separated, no signaling is possible in either direction. In the context of a concrete physical theory, the correlations compatible with a given causal configuration may obey further constraints. For instance, space-like correlations in quantum mechanics arise from local measurements on joint quantum states, while time-like correlations are established via quantum channels. Similarly to other variables, however, the causal order of a set of events could be random, and little is understood about the constraints that causality implies in this case. A main difficulty concerns the fact that the order of events can now generally depend on the operations performed at the locations of these events, since, for instance, an operation at A could influence the order in which B and C occur in A’s future. So far, no formal theory of causality compatible with such dynamical causal order has been developed. Apart from being of fundamental interest in the context of inferring causal relations, such a theory is imperative for understanding recent suggestions that the causal order of events in quantum mechanics can be indefinite. Here, we develop such a theory in the general multipartite case. Starting from a background-independent definition of causality, we derive an iteratively formulated canonical decomposition of multipartite causal correlations. For a fixed number of settings and

  11. Chaotic attractors with separated scrolls

    Energy Technology Data Exchange (ETDEWEB)

    Bouallegue, Kais, E-mail: kais-bouallegue@yahoo.fr [Department of Electrical Engineering, Higher Institute of Applied Sciences and Technology of Sousse, Sousse (Tunisia)

    2015-07-15

    This paper proposes a new behavior of chaotic attractors with separated scrolls while combining Julia's process with Chua's attractor and Lorenz's attractor. The main motivation of this work is the ability to generate a set of separated scrolls with different behaviors, which in turn allows us to choose one or many scrolls combined with modulation (amplitude and frequency) for secure communication or synchronization. This set seems a new class of hyperchaos because each element of this set looks like a simple chaotic attractor with one positive Lyapunov exponent, so the cardinal of this set is greater than one. This new approach could be used to generate more general higher-dimensional hyperchaotic attractor for more potential application. Numerical simulations are given to show the effectiveness of the proposed theoretical results.

  12. Bayesian Source Separation and Localization

    CERN Document Server

    Knuth, K H

    1998-01-01

    The problem of mixed signals occurs in many different contexts; one of the most familiar being acoustics. The forward problem in acoustics consists of finding the sound pressure levels at various detectors resulting from sound signals emanating from the active acoustic sources. The inverse problem consists of using the sound recorded by the detectors to separate the signals and recover the original source waveforms. In general, the inverse problem is unsolvable without additional information. This general problem is called source separation, and several techniques have been developed that utilize maximum entropy, minimum mutual information, and maximum likelihood. In previous work, it has been demonstrated that these techniques can be recast in a Bayesian framework. This paper demonstrates the power of the Bayesian approach, which provides a natural means for incorporating prior information into a source model. An algorithm is developed that utilizes information regarding both the statistics of the amplitudes...

  13. Magnetic Separator Enhances Treatment Possibilities

    Science.gov (United States)

    2008-01-01

    Since the earliest missions in space, NASA specialists have performed experiments in low gravity. Protein crystal growth, cell and tissue cultures, and separation technologies such as electrophoresis and magnetophoresis have been studied on Apollo 14, Apollo 16, STS-107, and many other missions. Electrophoresis and magnetophoresis, respectively, are processes that separate substances based on the electrical charge and magnetic field of a molecule or particle. Electrophoresis has been studied on over a dozen space shuttle flights, leading to developments in electrokinetics, which analyzes the effects of electric fields on mass transport (atoms, molecules, and particles) in fluids. Further studies in microgravity will continue to improve these techniques, which researchers use to extract cells for various medical treatments and research.

  14. Extraction and separation of proteoglycans.

    Science.gov (United States)

    Yanagishita, Masaki; Podyma-Inoue, Katarzyna Anna; Yokoyama, Miki

    2009-11-01

    Proteoglycans contain a unique carbohydrate component, glycosaminoglycan, which consists of repeating, typically sulfated disaccharides, and is capable of interacting with diverse molecules. Specific, clustered arrangements of sulfate on the glycosaminoglycan backbone form binding sites for many biologically important ligands such as extracellular matrix molecules and growth factors. Core proteins of proteoglycans also show molecular interactions necessary for organizing scaffolds in the extracellular matrix or for anchoring proteoglycans to the plasma membrane. Experimental protocols aiming at extracting maximal amounts of proteoglycans from tissues or cells require disruption of molecular interactions involving proteoglycans by denaturing solvents. Among many of the proteoglycan separation procedures, anion exchange chromatography, which takes advantage of the presence of highly negatively charged glycosaminoglycans in all proteoglycans, serves one of the most convenient general separation techniques.

  15. Neurointerventional participation in craniopagus separation

    OpenAIRE

    Alokaili, Riyadh Nasser; Ahmed, Muhammad Ejaz; Al Feryan, Ahmed; Goodrich, James T; Aloraidi, Ahmed

    2015-01-01

    Craniopagus-type conjoined twins (joined at the head) are exceedingly rare. Separation of craniopagus conjoined twins is a challenging task mainly owing to complex vascular anatomy and limited experience with this disorder. Modern neuroimaging techniques including digital subtraction angiography can be used to preoperatively assess the cerebral vascular system. These techniques can also provide the raw data to fabricate three-dimensional true-scale models. We report a case in which endovascul...

  16. Separations innovative concepts: Project summary

    Energy Technology Data Exchange (ETDEWEB)

    Lee, V.E. (ed.)

    1988-05-01

    This project summary includes the results of 10 innovations that were funded under the US Department's Innovative Concept Programs. The concepts address innovations that can substantially reduce the energy used in industrial separations. Each paper describes the proposed concept, and discusses the concept's potential energy savings, market applications, technical feasibility, prior work and state of the art, and future development needs.

  17. LISA propulsion module separation study

    Energy Technology Data Exchange (ETDEWEB)

    Merkowitz, S M [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Ahmad, A [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Hyde, T T [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Sweetser, T [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Ziemer, J [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Conkey, S [Swales Aerospace, 5050 Powder Mill Road, Beltsville, MD 20705 (United States); III, W Kelly [Swales Aerospace, 5050 Powder Mill Road, Beltsville, MD 20705 (United States); Shirgur, B [Swales Aerospace, 5050 Powder Mill Road, Beltsville, MD 20705 (United States)

    2005-05-21

    The Laser Interferometer Space Antenna (LISA) mission is a space-borne gravitational wave detector consisting of three sciencecraft in heliocentric orbit. Each sciencecraft is delivered to its operational orbit by a propulsion module. Because of the strict thermal and mass balancing requirements of LISA, the baseline mission concept requires that the propulsion module separate from the sciencecraft after delivery. The only propulsion system currently included in the sciencecraft design are micronewton level thrusters, such as field emission electric propulsion (FEEP) or colloid thrusters, that are used to balance the 30-40 {mu}N of solar radiation pressure and provide the drag-free and attitude control of the sciencecraft. Due to these thrusters' limited authority, the separation of the propulsion module from the sciencecraft must be well controlled to not induce a large tip-off rotation of the sciencecraft. We present here the results of a study of the propulsion module separation system requirements that are necessary to safely deliver the three LISA sciencecraft to their final operational orbits.

  18. Analytical Analysis of Motion Separability

    Directory of Open Access Journals (Sweden)

    Marjan Hadian Jazi

    2013-01-01

    Full Text Available Motion segmentation is an important task in computer vision and several practical approaches have already been developed. A common approach to motion segmentation is to use the optical flow and formulate the segmentation problem using a linear approximation of the brightness constancy constraints. Although there are numerous solutions to solve this problem and their accuracies and reliabilities have been studied, the exact definition of the segmentation problem, its theoretical feasibility and the conditions for successful motion segmentation are yet to be derived. This paper presents a simplified theoretical framework for the prediction of feasibility, of segmentation of a two-dimensional linear equation system. A statistical definition of a separable motion (structure is presented and a relatively straightforward criterion for predicting the separability of two different motions in this framework is derived. The applicability of the proposed criterion for prediction of the existence of multiple motions in practice is examined using both synthetic and real image sequences. The prescribed separability criterion is useful in designing computer vision applications as it is solely based on the amount of relative motion and the scale of measurement noise.

  19. Robust Simulations and Significant Separations

    CERN Document Server

    Fortnow, Lance

    2010-01-01

    We define and study a new notion of "robust simulations" between complexity classes which is intermediate between the traditional notions of infinitely-often and almost-everywhere, as well as a corresponding notion of "significant separations". A language L has a robust simulation in a complexity class C if there is a language in C which agrees with L on arbitrarily large polynomial stretches of input lengths. There is a significant separation of L from C if there is no robust simulation of L in C. The new notion of simulation is a cleaner and more natural notion of simulation than the infinitely-often notion. We show that various implications in complexity theory such as the collapse of PH if NP = P and the Karp-Lipton theorem have analogues for robust simulations. We then use these results to prove that most known separations in complexity theory, such as hierarchy theorems, fixed polynomial circuit lower bounds, time-space tradeoffs, and the theorems of Allender and Williams, can be strengthened to signifi...

  20. Improved electron transport layer

    DEFF Research Database (Denmark)

    2012-01-01

    The present invention provides: a method of preparing a coating ink for forming a zinc oxide electron transport layer, comprising mixing zinc acetate and a wetting agent in water or methanol; a coating ink comprising zinc acetate and a wetting agent in aqueous solution or methanolic solution...