WorldWideScience

Sample records for capillary water

  1. Uptake of water droplets by nonwetting capillaries

    CERN Document Server

    Willmott, Geoff R; Hendy, Shaun C

    2010-01-01

    We present direct experimental evidence that water droplets can spontaneously penetrate non-wetting capillaries, driven by the action of Laplace pressure due to high droplet curvature. Using high-speed optical imaging, microcapillaries of radius 50 to 150 micron, and water microdroplets of average radius between 100 and 1900 micron, we demonstrate that there is a critical droplet radius below which water droplets can be taken up by hydrophobised glass and polytetrafluoroethylene (PTFE) capillaries. The rate of capillary uptake is shown to depend strongly on droplet size, with smaller droplets being absorbed more quickly. Droplet size is also shown to influence meniscus motion in a pre-filled non-wetting capillary, and quantitative measurements of this effect result in a derived water-PTFE static contact angle between 96 degrees and 114 degrees. Our measurements confirm recent theoretical predictions and simulations for metal nanodroplets penetrating carbon nanotubes (CNTs). The results are relevant to a wide ...

  2. Capillary electrophoresis in tapered capillary manufactured by etching with sub-supercritical water

    Czech Academy of Sciences Publication Activity Database

    Karásek, Pavel; Horká, Marie; Šlais, Karel; Roth, Michal; Planeta, Josef

    Messina : Chromaleont S.r.L, 2012 - (Sandra, P.; Mondello, L.). s. 254 [International Symposium on Capillary Chromatography /36./ and GC x GC Symposium /9./. 27.5.2012-01.06.2012, Riva del Garda] R&D Projects: GA ČR(CZ) GAP206/11/0138; GA ČR(CZ) GAP106/12/0522; GA MV VG20112015021 Institutional research plan: CEZ:AV0Z40310501 Keywords : electrophoresis in tapered capillaries * supercritical water * complex samples Subject RIV: CB - Analytical Chemistry, Separation

  3. Water Films: Moisture that Extends Beyond the Capillary Wetting Front

    Science.gov (United States)

    Dragila, M. I.; Ambrowiak, G.

    2015-12-01

    Imbibition dynamics were investigated by measuring upward imbibition rates in laboratory vertical columns that were filled with sandy loam soil media. The contribution of films and capillary water which drives the infiltrating wetting front was successfully quantified. It was demonstrated that films move ahead of the wetting front only after capillary water has ceased driving percolation, and that the hydraulic diffusion coefficient (Dh) of film flow varied from 10-70% of the hydraulic diffusion coefficient of capillary water. The magnitude of Dh depended upon particle size distribution, surface roughness and initial moisture content of the media. What is the potential value of this mechanism in soil moisture dynamics research? (1) In coarse textured soils with low capillary potential, film that stretches well beyond the capillary wetting front can provide moisture to microbiota and mycorhyza, thereby increasing nutrient diffusion to a broader area than by capillary based models (e.g., modeling of drip irrigation systems). Even though the potential role of films in these processes has been previously discussed, the magnitude of potential moisture delivery has not been measured. (2) Films surging ahead of a decelerating capillary front may reduce the effect of subsurface water repellency. It is known that over time, moisture decreases both the contact angle of water against silica and water repellent soils. Therefore, in time, a film may predispose sandy soil to greater imbibition capacity. (3) The need to maximize water efficiency becomes exceedingly important in drought threatened, semi-arid irrigated agriculture. A thoughtful, yet realistic balance must be reached between water conservation and crop production. As our climate changes and water needs increase, protecting against crop failure will require a more comprehensive understanding of the mechanisms that control soil moisture dynamics. This study adds to this conversation by investigating higher level

  4. Dynamics of Gravity-Capillary Solitary Waves in Deep Water

    OpenAIRE

    Wang, Zhan; Milewski, Paul A.

    2012-01-01

    The dynamics of solitary gravity-capillary water waves propagating on the surface of a three-dimensional fluid domain is studied numerically. In order to accurately compute complex time dependent solutions, we simplify the full potential flow problem by taking a cubic truncation of the scaled Dirichlet-to-Neumann operator for the normal velocity on the free surface. This approximation agrees remarkably well with the full equations for the bifurcation curves, wave profiles and the dynamics of ...

  5. Thermal capillary waves in colloid-polymer mixtures in water

    International Nuclear Information System (INIS)

    We develop two colloid-polymer mixtures in water and study their phase and interface behaviour by means of confocal scanning laser microscopy. The systems consist either of silica or of poly(methylmethacrylate) particles, fluorescently labelled, with, as the polymer, xanthan. The fluid-fluid phase separation can be clearly followed in time and, depending on the concentrations and system details, we observe coarsening either of a bicontinuous spinodal structure or of a suspension of colloid-rich droplets. After phase separation has completed, we study the thermal capillary waves at the fluid-fluid interface. We construct correlation functions and compare with capillary wave theory. Finally, we demonstrate that these colloid-polymer systems are compatible with microfluidics.

  6. Thermal capillary waves in colloid-polymer mixtures in water

    Energy Technology Data Exchange (ETDEWEB)

    Jamie, E A G; Davies, G J; Howe, M D; Dullens, R P A; Aarts, D G A L [Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ (United Kingdom)], E-mail: dirk.aarts@chem.ox.ac.uk

    2008-12-10

    We develop two colloid-polymer mixtures in water and study their phase and interface behaviour by means of confocal scanning laser microscopy. The systems consist either of silica or of poly(methylmethacrylate) particles, fluorescently labelled, with, as the polymer, xanthan. The fluid-fluid phase separation can be clearly followed in time and, depending on the concentrations and system details, we observe coarsening either of a bicontinuous spinodal structure or of a suspension of colloid-rich droplets. After phase separation has completed, we study the thermal capillary waves at the fluid-fluid interface. We construct correlation functions and compare with capillary wave theory. Finally, we demonstrate that these colloid-polymer systems are compatible with microfluidics.

  7. Capillary pinching discharge as water window radiation source

    Czech Academy of Sciences Publication Activity Database

    Vrba, Pavel; Vrbová, M.; Jančárek, A.; Nevrkla, M.; Tamáš, M.; Stefanovic, M.

    Cancún: Institute of Physics(IOP), 2009 - (Juárez Reyes, A.), PB15-5-PB15-5. (ICPIG. 29). ISBN N. [The 29th International Conference on Phenomena in Ionized Gases 2009. Cancún (MX), 12.07.2009-17.07.2009] R&D Projects: GA ČR GA102/07/0275 Grant ostatní: GA MŠk.(CZ) LC528 Institutional research plan: CEZ:AV0Z20430508 Keywords : Capillary Z-pinch * water window radiation source * RHMD Z* engine Subject RIV: BH - Optics, Masers, Lasers http://www.icpig2009.unam.mx

  8. Pinching Capillary Discharge as a Water Window Radiation Source

    Czech Academy of Sciences Publication Activity Database

    Vrba, Pavel; Zakharov, S.V.; Jančárek, A.; Vrbová, M.; Nevrkla, M.; Kolař, P.

    2011-01-01

    Roč. 184, 3-6 (2011), s. 335-337. ISSN 0368-2048. [The 37th International Conference on Vacuum Ultraviolet and X-ray Physics (VUVX2010). Vancouver, 11.07.2010-16.07.2010] R&D Projects: GA MŠk LA08024 Institutional research plan: CEZ:AV0Z20430508 Keywords : Capillary Z-pinch * water window radiation * soft x-ray spectral diagnostics * RHMD Z* engine Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.958, year: 2011 http://www.sciencedirect.com/science/article/pii/S0368204810002847

  9. Dynamics of Gravity-Capillary Solitary Waves in Deep Water

    CERN Document Server

    Wang, Zhan

    2012-01-01

    The dynamics of solitary gravity-capillary water waves propagating on the surface of a three-dimensional fluid domain is studied numerically. In order to accurately compute complex time dependent solutions, we simplify the full potential flow problem by taking a cubic truncation of the scaled Dirichlet-to-Neumann operator for the normal velocity on the free surface. This approximation agrees remarkably well with the full equations for the bifurcation curves, wave profiles and the dynamics of solitary waves for a two-dimensional fluid domain. Fully localised solitary waves are then computed in the three-dimensional problem and the stability and interaction of both line and localized solitary waves are investigated via numerical time integration of the equations. The solitary wave branches are indexed by their finite energy at small amplitude, and the dynamics of the solitary waves is complex involving nonlinear focussing of wave packets, quasi-elastic collisions, and the generation of propagating, spatially lo...

  10. Regularity for steady periodic capillary water waves with vorticity.

    Science.gov (United States)

    Henry, David

    2012-04-13

    In the following, we prove new regularity results for two-dimensional steady periodic capillary water waves with vorticity, in the absence of stagnation points. Firstly, we prove that if the vorticity function has a Hölder-continuous first derivative, then the free surface is a smooth curve and the streamlines beneath the surface will be real analytic. Furthermore, once we assume that the vorticity function is real analytic, it will follow that the wave surface profile is itself also analytic. A particular case of this result includes irrotational fluid flow where the vorticity is zero. The property of the streamlines being analytic allows us to gain physical insight into small-amplitude waves by justifying a power-series approach. PMID:22393112

  11. Water Tank with Capillary Air/Liquid Separation

    Science.gov (United States)

    Ungar, Eugene K.; Smith, Frederick; Edeen, Gregg; Almlie, Jay C.

    2010-01-01

    A bladderless water tank (see figure) has been developed that contains capillary devices that allow it to be filled and emptied, as needed, in microgravity. When filled with water, the tank shields human occupants of a spacecraft against cosmic radiation. A membrane that is permeable by air but is hydrophobic (neither wettable nor permeable by liquid water) covers one inside surface of the tank. Grooves between the surface and the membrane allow air to flow through vent holes in the surface as the tank is filled or drained. A margin of wettable surface surrounds the edges of the membrane, and all the other inside tank surfaces are also wettable. A fill/drain port is located in one corner of the tank and is covered with a hydrophilic membrane. As filling begins, water runs from the hydrophilic membrane into the corner fillets of the tank walls. Continued filling in the absence of gravity will result in a single contiguous air bubble that will be vented through the hydrophobic membrane. The bubble will be reduced in size until it becomes spherical and smaller than the tank thickness. Draining the tank reverses the process. Air is introduced through the hydrophobic membrane, and liquid continuity is maintained with the fill/drain port through the corner fillets. Even after the tank is emptied, as long as the suction pressure on the hydrophilic membrane does not exceed its bubble point, no air will be drawn into the liquid line.

  12. Revisiting the applications of drainage capillary pressure curves in water-wet hydrocarbon systems

    Science.gov (United States)

    Nemes, István

    2016-01-01

    The main focus of the paper is to introduce a new approach at studying and modelling the relationship of initial water saturation profile and capillarity in water-wet hydrocarbon reservoirs, and describe the available measurement methods and possible applications. As a side track it aims to highlight a set of derivable parameters of mercury capillary curves using the Thomeer-method. Since the widely used mercury capillary pressure curves themselves can lead to over-, or underestimations regarding in-place and technical volumes and misinterpreted reservoir behaviour, the need for a proper capillary curve is reasonable. Combining the results of mercury and centrifuge capillary curves could yield a capillary curve preserving the strengths of both methods, while overcoming their weaknesses. Mercury injection capillary curves were normalized by using the irreducible water saturations derived from centrifuge capillary pressure measurements of the same core plug, and this new, combined capillary curve was applied for engineering calculations in order to make comparisons with other approaches. The most significant benefit of this approach is, that all of the measured data needed for a valid drainage capillary pressure curve represents the very same sample piece.

  13. Thermally excited capillary waves at vapor/liquid interfaces of water-alcohol mixtures

    International Nuclear Information System (INIS)

    The density profiles of liquid/vapor interfaces of water-alcohol (methanol, ethanol and propanol) mixtures were studied by surface-sensitive synchrotron x-ray scattering techniques. X-ray reflectivity and diffuse scattering measurements, from the pure and mixed liquids, were analyzed in the framework of capillary wave theory to address the characteristic length scales of the intrinsic roughness and the shortest capillary wavelength (alternatively, the upper wavevector cutoff in capillary wave theory). Our results establish that the intrinsic roughness is dominated by average interatomic distances. The extracted effective upper wavevector cutoff indicates capillary wave theory breaks down at distances of the order of bulk correlation lengths.

  14. Performance Evaluation of Automated Passive Capillary Sampler for Estimating Water Drainage in the Vadose Zone

    Science.gov (United States)

    Passive capillary samplers (PCAPs) are widely used to monitor, measure and sample drainage water under saturated and unsaturated soil conditions in the vadose zone. The objective of this study was to evaluate the performance and accuracy of automated passive capillary sampler for estimating drainage...

  15. Synthesis and Characterization of Water-Soluble Carboxymethyl-Cyclodextrin Polymer as Capillary Electrophoresis Chiral Selector

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The water-soluble carboxymethyl-cyclodextrin polymer (CM-CD polymer) was synthesized and used as capillary electrophoresis chiral selector.Verrapamil and thiopentorusodium were well separated using CM-CD polymer as chiral selector.

  16. A capillary network model for coupled gas and water flow in engineered barriers

    International Nuclear Information System (INIS)

    A two-dimensional capillary network model for gas migration through a water-saturated medium is presented. The model is an extension of previously developed capillary bundle models, and provides a discrete alternative to classical continuum Darcy models. The need for such an alternative has become apparent from recent experimental results that suggest gas migrates through low permeability water-saturated media via a small number of preferential pathways

  17. Capillary rise simulation of saline waters of different concentrations in sandy soils

    Directory of Open Access Journals (Sweden)

    Natthawit Jitrapinate

    2016-06-01

    Full Text Available Soil salinity causes corrosion of engineering structures worldwide. The main cause of soil salinization is capillary rise of saline groundwater. Soil salinity can be mitigated once the capillary rise of saline groundwater in soils is understood. The objective of this paper is to present experimental results of capillary rising rates of different salt concentration waters in three sandy soils. Each sample comprised of a soil column 300-mm height and 50-mm in diameter steeped in a 25-mm deep saline water pool for a time period to allow for the capillary action to develop. The salinity strength varied from fresh water, EC = 2 dS/m, to medium saline (50, 100, and 150 dS/m, and to high saline water (200 dS/m. It was found that the highest rate of capillary rise occurred in medium saline waters, while the lowest is the fresh water. The very saline water has lower rate than the medium ones but higher than fresh water.

  18. EFFECT OF SURFACTANT ON TWO-PHASE FLOW PATTERNS OF WATER-GAS IN CAPILLARY TUBES

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Flow patterns of liquid-gas two-phase flow were experimentally investigated. The experiments were carried out in both vertical and horizontal capillary tubes having inner diameters of 1.60 mm. The working liquid was the mixture of water and Sodium Dodecyl Benzoyl Sulfate (SDBS). The working gas was Nitrogen. For the water/SDBS mixture-gas flow in the vertical capillary tube, flow-pattern transitions occurred at lower flow velocities than those for the water-gas flow in the same tube. For the water/SDBS mixture-gas flow in the horizontal capillary tube, surface tension had little effect on the bubbly-intermittent transition and had only slight effect on the plug-slug and slug-annular transitions. However, surface tension had significant effect on the wavy stratified flow regime. The wavy stratified flow regime of water/SDBS mixture-gas flow expanded compared with that of water-gas.

  19. Water treated capillaries – Further options for CZE and CIEF analyses

    Czech Academy of Sciences Publication Activity Database

    Karásek, Pavel; Horká, Marie; Šlais, Karel; Planeta, Josef; Roth, Michal

    Veszprém: Hungarian Society for Separation Sciences, 2015. s. 73-73. ISBN 978-615-5270-18-5. [Balaton Symposium on High-Performance Separation Methods /10./. 02.09.2015-04.09.2015, Siófok] R&D Projects: GA MV VG20112015021 Institutional support: RVO:68081715 Keywords : capillary electromigration methods * supercritical water-treated fused-silica capillary * sensitivity enhancement Subject RIV: CB - Analytical Chemistry, Separation

  20. Determination of capillary motion of water in bricks using neutron radiography

    International Nuclear Information System (INIS)

    Vertical migration of water in several porous materials has been directly observed and recorded with the recently installed neutron and gamma radiography facility at Maria reactor of Institute of Atomic Energy, Swierk. The density profiles of water in samples were obtained from the optical density of digitalised images. A simple model (representing the porous material as a collection of capillary tubes of various radii) has been introduced to describe the liquid transport in porous materials in terms of capillary motion. The equation for viscous movement of water in porous material in presence of the gravitation is proposed. A good agreement of the calculated density profiles for vertical water migration with the data collected for siliceous bricks suggests that the thinnest capillary tubes determine the upper edge of the water density profile. (author)

  1. Asymmetric gravity-capillary solitary waves on deep water

    OpenAIRE

    Z. Wang; Vanden-Broeck, J-M; Milewski, P. A.

    2014-01-01

    We present new families of gravity–capillary solitary waves propagating on the surface of a two-dimensional deep fluid. These spatially localised travelling-wave solutions are non-symmetric in the wave propagation direction. Our computation reveals that these waves appear from a spontaneous symmetry-breaking bifurcation, and connect two branches of multi-packet symmetric solitary waves. The speed–energy bifurcation curve of asymmetric solitary waves features a zigzag behaviour with one or mor...

  2. A plethora of generalised solitary gravity-capillary water waves

    OpenAIRE

    Clamond, Didier; Dutykh, Denys; Durán, Angel

    2015-01-01

    The present study describes, first, an efficient algorithm for computing capillary-gravity solitary waves solutions of the irrotational Euler equations with a free surface and, second, provides numerical evidences of the existence of (likely) an infinite number of generalised solitary waves (solitary waves with undamped oscillatory wings). Using conformal mapping, the unknown fluid domain, which is to be determined, is mapped into a uniform strip of the complex plane. In the transformed domai...

  3. Capillary-driven spontaneous oil/water separation by superwettable twines

    Science.gov (United States)

    Xu, Li-Ping; Dai, Bing; Fan, Junbing; Wen, Yongqiang; Zhang, Xueji; Wang, Shutao

    2015-07-01

    A superwettable twine showing excellent absorption and self-removal capacity of oil and water from oil/water mixtures is reported. Superwettable materials are fabricated by simple modification of commercial twines with plasma and hydrophobic silica nanoparticles, respectively. We show that the absorption and self-transportation of oil and water are driven by the capillary force resulting from the microgaps and microgrooves on twines.A superwettable twine showing excellent absorption and self-removal capacity of oil and water from oil/water mixtures is reported. Superwettable materials are fabricated by simple modification of commercial twines with plasma and hydrophobic silica nanoparticles, respectively. We show that the absorption and self-transportation of oil and water are driven by the capillary force resulting from the microgaps and microgrooves on twines. Electronic supplementary information (ESI) available: Experimental details, characterization and XPS. See DOI: 10.1039/c5nr03670d

  4. A plethora of generalised solitary gravity-capillary water waves

    CERN Document Server

    Clamond, Didier; Duran, Angel

    2014-01-01

    The present study describes, first, an efficient algorithm for computing gravity-capillary solitary waves solutions of the irrotational Euler equations and, second, provides numerical evidences of the existence of (likely) an infinite number of generalised solitary waves (i.e. solitary waves with undamped oscillatory wings). Using conformal mapping, the unknown fluid domain (which is to be determined) is mapped into a uniform strip of the complex plane. A Babenko-like equation is then derived from a Lagrangian expressed in the transformed domain. The Babenko equation is then solved numerically using a Levenberg-Marquardt algorithm. Various interesting solutions are computed, some of them being known, some seem to be new. The emergence of generalised solitary waves is shown when the Bond number is increased.

  5. Near- and supercritical water as a diameter manipulation and surface roughening agent in fused silica capillaries

    Czech Academy of Sciences Publication Activity Database

    Karásek, Pavel; Planeta, Josef; Roth, Michal

    2013-01-01

    Roč. 85, č. 1 (2013), s. 327-333. ISSN 0003-2700 R&D Projects: GA ČR(CZ) GAP106/12/0522; GA ČR(CZ) GAP206/11/0138 Institutional support: RVO:68081715 Keywords : supercritical water * fused silica capillary * surface treatment Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 5.825, year: 2013

  6. Isoelectric focusing in continuously tapered fused silica capillary prepared by etching with supercritical water

    Czech Academy of Sciences Publication Activity Database

    Šlais, Karel; Horká, Marie; Karásek, Pavel; Planeta, Josef; Roth, Michal

    2013-01-01

    Roč. 85, č. 9 (2013), s. 4296-4300. ISSN 0003-2700 R&D Projects: GA ČR(CZ) GAP106/12/0522; GA MV VG20102015023 Institutional support: RVO:68081715 Keywords : capillary isoelectric focusing * resolution of ampholytes * supercritical water Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 5.825, year: 2013

  7. Near-surface viscosity effects on capillary rise of water in nanotubes.

    Science.gov (United States)

    Vo, Truong Quoc; Barisik, Murat; Kim, BoHung

    2015-11-01

    In this paper, we present an approach for predicting nanoscale capillary imbibitions using the Lucas-Washburn (LW) theory. Molecular dynamics (MD) simulations were employed to investigate the effects of surface forces on the viscosity of liquid water. This provides an update to the modified LW equation that considered only a nanoscale slip length. An initial water nanodroplet study was performed to properly elucidate the wetting behavior of copper and gold surfaces. Intermolecular interaction strengths between water and corresponding solid surfaces were determined by matching the contact angle values obtained by experimental measurements. The migration of liquid water into copper and gold capillaries was measured by MD simulations and was found to differ from the modified LW equation. We found that the liquid layering in the vicinity of the solid surface induces a higher density and viscosity, leading to a slower MD uptake of fluid into the capillaries than was theoretically predicted. The near-surface viscosity for the nanoscale-confined water was defined and calculated for the thin film of water that was sheared between the two solid surfaces, as the ratio of water shear stress to the applied shear rate. Considering the effects of both the interface viscosity and slip length of the fluid, we successfully predicted the MD-measured fluid rise in the nanotubes. PMID:26651781

  8. Near-surface viscosity effects on capillary rise of water in nanotubes

    Science.gov (United States)

    Vo, Truong Quoc; Barisik, Murat; Kim, BoHung

    2015-11-01

    In this paper, we present an approach for predicting nanoscale capillary imbibitions using the Lucas-Washburn (LW) theory. Molecular dynamics (MD) simulations were employed to investigate the effects of surface forces on the viscosity of liquid water. This provides an update to the modified LW equation that considered only a nanoscale slip length. An initial water nanodroplet study was performed to properly elucidate the wetting behavior of copper and gold surfaces. Intermolecular interaction strengths between water and corresponding solid surfaces were determined by matching the contact angle values obtained by experimental measurements. The migration of liquid water into copper and gold capillaries was measured by MD simulations and was found to differ from the modified LW equation. We found that the liquid layering in the vicinity of the solid surface induces a higher density and viscosity, leading to a slower MD uptake of fluid into the capillaries than was theoretically predicted. The near-surface viscosity for the nanoscale-confined water was defined and calculated for the thin film of water that was sheared between the two solid surfaces, as the ratio of water shear stress to the applied shear rate. Considering the effects of both the interface viscosity and slip length of the fluid, we successfully predicted the MD-measured fluid rise in the nanotubes.

  9. Symmetry breaking in periodic and solitary gravity-capillary waves on water of finite depth

    OpenAIRE

    Zufiria, Juan A.

    1987-01-01

    A weakly nonlinear model is developed from the Hamiltonian formulation of water waves, to study the bifurcation structure of gravity-capillary waves on water of finite depth. It is found that, besides a very rich structure of symmetric solutions, non-symmetric Wilton's ripples exist. They appear via a spontaneous symmetry breaking bifurcation from symmetric solutions. The bifurcation tree is similar to that for gravity waves. The solitary wave with surface tension is studied with the same mod...

  10. Effect of capillary-condensed water on the dynamic friction force at nanoasperity contacts

    Science.gov (United States)

    Sirghi, L.

    2003-05-01

    A single nanoasperity contact in ambient air is usually wetted by capillary condensation of water vapor and is surrounded by a water meniscus. This phenomenon strongly affects the contact friction, not only by the effect of meniscus loading force (superficial tension and capillary forces), but also by a friction force that accounts for the energy loss in the meniscus movement along with the sliding contact. Occurrence of the water-meniscus-generated friction is experimentally proved by atomic force microscopy measurements of the tip-sample friction force at minimum possible external load (before pull-off). A qualitative explanation for the observed dependence of the friction force on air humidity and solid surface wettability is proposed.

  11. Early Regimes of Water Capillary Flow in Slit Silica Nanochannels

    DEFF Research Database (Denmark)

    Oyarzua, Elton; Walther, Jens Honore; Mejia, Andres;

    2015-01-01

    Molecular dynamics simulations are conducted to investigate the initial stages of spontaneous imbibitionof water in slit silica nanochannels surrounded by air. An analysis is performed for the effects of nanoscopicconfinement, initial conditions of liquid uptake and air pressurization on the...

  12. Effect of air on water capillary flow in silica nanochannels

    DEFF Research Database (Denmark)

    Zambrano, Harvey; Walther, Jens Honore; Oyarzua, Elton

    2013-01-01

    Capillarity is a classical topic in fluid dynamics. The fundamental relationship between capillarity and surface tension is solidly established. Nevertheless, capillarity is an active research area especially as the miniaturization of devices is reaching the molecular scale. Currently, with the f...... which leads to changes in the dynamics contact angle of the water meniscus....

  13. Mapping Human Brain Capillary Water Lifetime: High-Resolution Metabolic Neuromaging

    Science.gov (United States)

    Rooney, William D.; Li, Xin; Sammi, Manoj K.; Bourdette, Dennis N.; Neuwelt, Edward A.; Springer, Charles S.

    2016-01-01

    Shutter-speed analysis of Dynamic-Contrast-Agent-(CA)-Enhanced normal, multiple sclerosis [MS], and glioblastoma [GBM] human brain data gives the mean capillary water molecule lifetime [τb] and blood volume fraction [vb; capillary density·volume product (′†·V)] in a high-resolution 1H2O MRI voxel [40 μL] or ROI. The equilibrium water extravasation rate constant, kpo [τb−1], averages 3.2 and 2.9 s−1 in resting-state normal white matter [NWM] and gray matter [NGM], respectively [n = 6]. The results {parenthesized} lead to three major conclusions. A) kpo differences are dominated by capillary water permeability [PW†], not size, differences. {NWM and NGM voxel kpo and vb values are independent. Quantitative analyses of concomitant population-averaged kpo,vb variations in normal and normal-appearing MS brain ROIs confirm PW† dominance.} B) PW† is dominated [> 95%] by a trans[endothelial]cellular pathway, not the PCA† para-cellular route. {In MS lesions and GBM tumors, PCA† increases but PW† decreases.} C) kpo tracks steady-state ATP production/consumption flux per capillary. {In normal, MS, and GBM brain, regional kpo correlates with literature MRSI ATP [positively] and Na+ [negatively] tissue concentrations. These suggest the PW† pathway is metabolically active. Excellent agreement of the relative NGM/NWM kpo·vb product ratio with the literature 31PMRSI-MT CMRoxphos ratio confirms the flux property.} We have previously shown the cellular water molecule efflux rate constant [kio] is proportional to plasma membrane P-type ATPase turnover, likely due to active trans-membrane water cycling. With synaptic proximities and synergistic metabolic co-operativities, polar brain endothelial, neuroglial, and neuronal cells form “gliovascular units.” We hypothesize a chain of water cycling processes transmits brain metabolic activity to kpo, letting it report neurogliovascular unit Na+,K+-ATPase activity. Cerebral kpo maps represent metabolic

  14. Customization of fused silica capillary properties by supercritical water treatment: Application in electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Karásek, Pavel; Horká, Marie; Roth, Michal; Šlais, Karel; Šalplachta, Jiří; Planeta, Josef

    Universidad de La Laguna, 2013. s. 220. [International Symposium on Electro- and Liquid Phase-separation Techniques /20./. 06.10.2013-09.10.2013, Puerto de la Cruz, Tenerife] R&D Projects: GA MV VG20112015021; GA ČR(CZ) GAP106/12/0522 Institutional support: RVO:68081715 Keywords : fused silica capillary * supercritical water * electromigration separations Subject RIV: CB - Analytical Chemistry, Separation

  15. Characteristics of AC capillary discharge produced in electrically conductive water solution

    Czech Academy of Sciences Publication Activity Database

    De Baerdemaeker, F.; Šimek, Milan; Schmidt, Jiří; Leys, C.

    2007-01-01

    Roč. 16, č. 2 (2007), s. 341-354. ISSN 0963-0252 R&D Projects: GA AV ČR IAA1043102 Institutional research plan: CEZ:AV0Z20430508 Keywords : water breakdown * capillary * AC discharge * conductive liquid * optical emission * decay time * vapour bubble * breakdown mechanism Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.120, year: 2007

  16. Influence of capillary forces on water injection into hot rock, saturated with superheated vapour

    Energy Technology Data Exchange (ETDEWEB)

    Tsypkin, G.G. [Institute for Problems in Mechanics, RAS, Vernadskogo Ave. 101, 119420 Moscow (Russian Federation); Calore, C. [Istituto di Geoscienze e Georisorse - CNR, Sezione di Firenze, via La Pira 4, 50121 Florence (Italy)

    2007-07-15

    The results of a theoretical study and numerical analysis of the role of capillary pressure of cold water injection into depleted geothermal reservoirs are presented. A simplified 1-D mathematical model is developed, that describes the motion of a sharp vaporization front. Some asymptotic estimates for a wide range of parameters are given and a similarity solution is derived. Analytical results are then compared with those obtained from the numerical reservoir simulator TOUGH2, showing a good agreement between the two. (author)

  17. Rapid capillary filling via ion-water interactions over the nanoscale

    Science.gov (United States)

    Bakli, Chirodeep; Chakraborty, Suman

    2016-03-01

    Giant frictional resistances are grand challenges against the rapid filling of nanoscale capillaries, as encountered in a wide variety of applications ranging from nature to energy. It is commonly believed that partially wettable charged nanocapillaries fill up considerably slower, compared to completely wettable ones, under the influence of a complex interplay between interfacial tension and electrical interactions. In sharp contrast to this common belief, here we discover a new non-intuitive regime of rapid filling of charged capillaries over the nanometer scale, by virtue of which a partially wettable capillary may fill up comparatively faster than a completely wettable one. We attribute the fundamental origin of this remarkable behavior to ion-water interactions over interfacial scales. The underlying novel electro-hydrodynamic mechanism, as unveiled here, may provide deeper insights into the physico-chemical interactions leading to augmentations in the rates of nanocapillary filling over hydrophobic regimes, bearing far-reaching implications in the transport of biological fluids, enhanced oil recovery, and miniaturized energy harvesting applications.Giant frictional resistances are grand challenges against the rapid filling of nanoscale capillaries, as encountered in a wide variety of applications ranging from nature to energy. It is commonly believed that partially wettable charged nanocapillaries fill up considerably slower, compared to completely wettable ones, under the influence of a complex interplay between interfacial tension and electrical interactions. In sharp contrast to this common belief, here we discover a new non-intuitive regime of rapid filling of charged capillaries over the nanometer scale, by virtue of which a partially wettable capillary may fill up comparatively faster than a completely wettable one. We attribute the fundamental origin of this remarkable behavior to ion-water interactions over interfacial scales. The underlying novel

  18. Sub-critical Column and Capillary Chromatography with Water as Mobile Phase and Flame Ionization Detection

    Institute of Scientific and Technical Information of China (English)

    LuFeng; LiLing; SunPeng; WuYutian

    2001-01-01

    A sub-critical chromatography (SubWC) with water as mobile phase and FID detection system is employed to separate several alcohols with high or medium polarity, with pure water as the eluent. The flow rate gets up to 50 μ1-min-1 for packed column (1 mm i.d.) and 70 μ1-min-1 for capillary (50 μm i.d.). Increasing the temperatureup to 140℃, together with temperature programming, markedly improves the separation and peak shapes within short analysis time. Sub-critical state is guaranteed.

  19. Increased Water Retention in Polymer Electrolyte Membranes at Elevated Temperatures Assisted by Capillary Condensation

    International Nuclear Information System (INIS)

    We establish a new systematic methodology for controlling the water retention of polymer electrolyte membranes. Block copolymer membranes comprising hydrophilic phases with widths ranging from 2 to 5 nm become wetter as the temperature of the surrounding air is increased at constant relative humidity. The widths of the moist hydrophilic phases were measured by cryogenic electron microscopy experiments performed on humid membranes. Simple calculations suggest that capillary condensation is important at these length scales. The correlation between moisture content and proton conductivity of the membranes is demonstrated.

  20. Increased Water Retention in Polymer Electrolyte Membranes at Elevated Temperatures Assisted by Capillary Condensation

    Energy Technology Data Exchange (ETDEWEB)

    Park, M.J.; Downing, K.H.; Jackson, A.; Gomez, E.D.; Minor, A.M.; Cookson, D.; Weber, A.Z.; Balsara, N.P. (UCB); (NIST); (LBNL); (UC)

    2008-10-03

    We establish a new systematic methodology for controlling the water retention of polymer electrolyte membranes. Block copolymer membranes comprising hydrophilic phases with widths ranging from 2 to 5 nm become wetter as the temperature of the surrounding air is increased at constant relative humidity. The widths of the moist hydrophilic phases were measured by cryogenic electron microscopy experiments performed on humid membranes. Simple calculations suggest that capillary condensation is important at these length scales. The correlation between moisture content and proton conductivity of the membranes is demonstrated.

  1. Analyses of Phytohormones in Coconut (Cocos Nucifera L. Water Using Capillary Electrophoresis-Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Swee Ngin Tan

    2014-12-01

    Full Text Available Capillary electrophoresis (CE coupled with mass spectrometry (MS or tandem mass spectrometry (MS/MS is reported as an alternative and potentially useful method for the simultaneous analysis of various classes of phytohormones with diversified structures, including indole-3-acetic acid (IAA, indole-3-butyric acid (IBA, abscisic acid (ABA, gibberellic acid (GA, zeatin (Z, N6-benzyladenine (BA, α-naphthaleneacetic acid (NAA and 2,4-dichlorophenoxyacetic acid (2,4-D. The key to the CE-MS/MS analysis was based on electroosmotic flow reversal using a cationic polymer-coated capillary. Under optimum conditions, a baseline separation of eight phytohormones was accomplished within 30 min using 60 mM ammonium formate/formic acid buffer of pH 3.8 with −20 kV as the separation voltage. The accessibility of MS/MS together with the characterization by migration properties obtained by CE allows for the development of CE-MS/MS as an emerging potential method for the analysis of different classes of phytohormones in a single run. The utility of the CE-MS/MS method was demonstrated by the comprehensive screening of phytohormones in coconut (Cocos nucifera L. water after pre-concentration and purification through solid-phase extraction (SPE cartridge. IAA, ABA, GA and Z were detected and quantified in the purified coconut water extract sample.

  2. Computational micro-scale model of control of extravascular water and capillary perfusion in the air blood barrier.

    Science.gov (United States)

    Mazzuca, Enrico; Aliverti, Andrea; Miserocchi, Giuseppe

    2016-07-01

    A computational model of a morphologically-based alveolar capillary unit (ACU) in the rabbit is developed to relate lung fluid balance to mechanical forces between capillary surface and interstitium during development of interstitial edema. We hypothesize that positive values of interstitial liquid pressure Pliq impact on capillary transmural pressure and on blood flow. ACU blood flow, capillary recruitment and filtration are computed by modulating vascular and interstitial pressures. Model results are compared with experimental data of Pliq increasing from ~-10 (control) up to ~4cmH2O in two conditions, hypoxia and collagenase injection. For hypoxia exposure, fitting data requires a linear increase in hydraulic conductivity Lp and capillary pressure PC, that fulfils the need of increase in oxygen delivery. For severe fragmentation of capillary endothelial barrier (collagenase injection), fitting requires a rapid increase in both hydraulic and protein permeability, causing ACU de-recruitment, followed by an increase in PC as a late response to restore blood flow. In conclusion, the model allows to describe the lung adaptive response to edemagenic perturbations; the increase in Pliq, related to the low interstitial compliance, provides an efficient control of extravascular water, by limiting microvascular filtration. PMID:27059893

  3. Routine quality control of recycled target [18O]water by capillary electrophoresis and gas chromatography

    International Nuclear Information System (INIS)

    Recycling of [18O]water for [18F]fluoride production can be accomplished with reliable results. We have developed sensitive, robust, and rapid analyses of impurities in [18O]water. Anions were quantitated by capillary electrophoresis and organic residuals were quantitated by gas chromatography using methods with excellent reproducibility and linearity. Kryptofix 222 (K-222) was quantitated by a sensitive LC-MS-MS technique. Isotopic composition was determined by GC-MS with satisfactory accuracy and precision. These methods were employed to evaluate recovered [18O]water purified by a novel electrolysis method. 2-[18F]FDG yields using purified [18O]water with very low levels of impurities are indistinguishable from newly purchased [18O]water. High (> 300 ppm) carbonate concentration reduces the fluoride trapping efficiency of QMA. The analyses of anions, organics, and isotopic enrichment were applied routinely for quality control of [18O]water to predict a satisfactory outcome of 2-[18F]FDG production

  4. Force exerted by a nanoscale capillary water bridge between two planar substrates.

    Science.gov (United States)

    Valenzuela, Gerson E; Saavedra, Jorge H; Rozas, Roberto E; Toledo, Pedro G

    2016-04-20

    Molecular dynamics simulation of a nanoscale capillary water bridge between two planar substrates is used to determine the resulting force between the substrates without arbitrariness regarding geometry and location of the free surface of the bridge. The substrates are moderately hydrophilic. The force changes continuously as the separation between the substrates changes except for small gaps where it becomes discontinuous because the bridge is unable to adopt stable configurations at any distance apart. Further exploration of the bridge and the force as the substrates approach each other reveals an underlying oscillatory force with an increasing repulsive component at separation distances equivalent to few water molecules. According to the average number of hydrogen bonds per water molecule (HBN), at very small gap sizes, water molecules which are very close to the surfaces are unable to maximize HBN thus contributing to the repulsive force. Our simulation results of force versus gap size agree with calculations based on other methods, some very different, and also reproduce the typical magnitude of the experimental force. Finally, a macroscopic force balance correctly describes the force-distance curve except for bridges constituted of water layers only. PMID:27049515

  5. Experimental study of crossover from capillary to viscous fingering for supercritical CO2-water displacement in a homogeneous pore network.

    Science.gov (United States)

    Wang, Ying; Zhang, Changyong; Wei, Ning; Oostrom, Mart; Wietsma, Thomas W; Li, Xiaochun; Bonneville, Alain

    2013-01-01

    Carbon sequestration in saline aquifers involves displacing brine from the pore space by supercritical CO(2) (scCO(2)). The displacement process is considered unstable due to the unfavorable viscosity ratio between the invading scCO(2) and the resident brine. The mechanisms that affect scCO(2)-water displacement under reservoir conditions (41 °C, 9 MPa) were investigated in a homogeneous micromodel. A large range of injection rates, expressed as the dimensionless capillary number (Ca), was studied in two sets of experiments: discontinuous-rate injection, where the micromodel was saturated with water before each injection rate was imposed, and continuous-rate injection, where the rate was increased after quasi-steady conditions were reached for a certain rate. For the discontinuous-rate experiments, capillary fingering and viscous fingering are the dominant mechanisms for low (logCa ≤ -6.61) and high injection rates (logCa ≥ -5.21), respectively. Crossover from capillary to viscous fingering was observed for logCa = -5.91 to -5.21, resulting in a large decrease in scCO(2) saturation. The discontinuous-rate experimental results confirmed the decrease in nonwetting fluid saturation during crossover from capillary to viscous fingering predicted by numerical simulations by Lenormand et al. (J. Fluid Mech.1988, 189, 165-187). Capillary fingering was the dominant mechanism for all injection rates in the continuous-rate experiment, resulting in monotonic increase in scCO(2) saturation. PMID:22676368

  6. Design Status of the Capillary Brine Residual in Containment Water Recovery System

    Science.gov (United States)

    Callahan, Michael R.; Sargusingh, Miriam

    2016-01-01

    One of the goals of the AES Life Support System (LSS) Project is to achieve 98% water loop closure for long duration human exploration missions beyond low Earth orbit. To meet this objective, the AES LSS Project is developing technologies to recover water from wastewater brine; highly concentrated waste products generated from a primary water recovery system. The state of the art system used aboard the International Space Station (ISS) has the potential to recover up to 85% water from unine wastewater, leaving a significant amounts of water in the waste brine, the recovery of which is a critical technology gap that must be filled in order to enable long duration human exploration. Recovering water from the urine wastewater brine is complicated by the concentration of solids as water is removed from the brine, and the concentration of the corrosive, toxic chemicals used to stabilize the urine which fouls and degrades water processing hardware, and poses a hazard to operators and crew. Brine Residual in Containment (BRIC) is focused on solids management through a process of "in-place" drying - the drying of brines within the container used for final disposal. Application of in-place drying has the potential to improve the safety and reliability of the system by reducing the exposure to crew and hardware to the problematic brine residual. Through a collaboration between the NASA Johnson Space Center and Portland Status University, a novel water recovery system was developed that utilizes containment geometry to support passive capillary flow and static phase separation allowing free surface evaporation to take place in a microgravity environment. A notional design for an ISS demonstration system was developed. This paper describes the concept for the system level design.

  7. Evaluation of capillary electrophoresis for in-flight ionic contaminant monitoring of SSF potable water

    Science.gov (United States)

    Mudgett, Paul D.; Schultz, John R.; Sauer, Richard L.

    1992-01-01

    Until 1989, ion chromatography (IC) was the baseline technology selected for the Specific Ion Analyzer, an in-flight inorganic water quality monitor being designed for Space Station Freedom. Recent developments in capillary electrophoresis (CE) may offer significant savings of consumables, power consumption, and weight/volume allocation, relative to IC technology. A thorough evaluation of CE's analytical capability, however, is necessary before one of the two techniques is chosen. Unfortunately, analytical methods currently available for inorganic CE are unproven for NASA's target list of anions and cations. Thus, CE electrolyte chemistry and methods to measure the target contaminants must be first identified and optimized. This paper reports the status of a study to evaluate CE's capability with regard to inorganic and carboxylate anions, alkali and alkaline earth cations, and transition metal cations. Preliminary results indicate that CE has an impressive selectivity and trace sensitivity, although considerable methods development remains to be performed.

  8. Supercritical water in analytical chemistry: A green solvent to manipulate fused-silica capillaries for separation methods

    Czech Academy of Sciences Publication Activity Database

    Karásek, Pavel; Horká, Marie; Šlais, Karel; Planeta, Josef; Roth, Michal

    Nottingham, 2013. O86. [International Conference on Green and Sustainable Chemistry /6./. 04.08.2013-07.08.2013, Nottingham] R&D Projects: GA ČR(CZ) GAP106/12/0522; GA MV VG20102015023 Institutional support: RVO:68081715 Keywords : supercritical water * fused silica capillary * analytical separation methods Subject RIV: CB - Analytical Chemistry , Separation

  9. Hydrolysis of polycarbonate in sub-critical water in fused silica capillary reactor with in situ Raman spectroscopy

    Science.gov (United States)

    Pan, Z.; Chou, I.-Ming; Burruss, R.C.

    2009-01-01

    The advantages of using fused silica capillary reactor (FSCR) instead of conventional autoclave for studying chemical reactions at elevated pressure and temperature conditions were demonstrated in this study, including the allowance for visual observation under a microscope and in situ Raman spectroscopic characterization of polycarbonate and coexisting phases during hydrolysis in subcritical water. ?? 2009 The Royal Society of Chemistry.

  10. Performance evaluation and accuracy of passive capillary samplers (PCAPs) for estimating real-time drainage water fluxes

    Science.gov (United States)

    Successful monitoring of pollutant transport through the soil profile requires accurate, reliable, and appropriate instrumentation to measure amount of drainage water or flux within the vadose layer. We evaluated the performance and accuracy of automated passive capillary wick samplers (PCAPs) for ...

  11. A purge-and-trap capillary column gas chromatographic method for the measurement of halocarbons in water and air

    Energy Technology Data Exchange (ETDEWEB)

    Happell, J.D.; Wallace, D.W.R.; Wills, K.D.; Wilke, R.J.; Neill, C.C.

    1996-06-01

    This report describes an automated, accurate, precise and sensitive capillary column purge- and -trap method capable of quantifying CFC-12, CFC-11, CFC-113, CH{sub 3}CCL{sub 3}, and CCL{sub 4} during a single chromatographic analysis in either water or gas phase samples.

  12. Capillary Electrophoresis Analysis of Cations in Water Samples: An Experiment for the Introductory Laboratory

    Science.gov (United States)

    Pursell, Christopher J.; Chandler, Bert; Bushey, Michelle M.

    2004-01-01

    Capillary electrophoresis is gradually working its way into the undergraduate laboratory curriculum. Typically, experiments utilizing this newer technology have been introduced into analytical or instrumental courses. The authors of this article have introduced an experiment into the introductory laboratory that utilizes capillary electrophoresis…

  13. Reverse polarity capillary zone electrophoresis analysis of nitrate and nitrite in natural water samples

    International Nuclear Information System (INIS)

    This paper describes the application of reverse polarity capillary zone electrophoresis (RPCE) for rapid and accurate determination of nitrate and nitrite in natural water samples. Using hexamethonium bromide (HMB) as an electroosmotic flow modifier in a borate buffer at pH 9.2, the resolution of nitrate and nitrite was accomplished in less than 3 minutes. RPCE was compared with ion chromatographic (IC) and cadmium reduction flow injection analysis (Cd-FIA) methods which are the two most commonly used standard methods for the analysis of natural water samples for nitrate and nitrite. When compared with the ion chromatographic method for the determination of nitrate and nitrite, RPCE reduced analysis time, decreased detection limits by a factor of 10, cut laboratory wastes by more than two orders of magnitude, and eliminated interferences commonly associated with IC. When compared with the cadmium reduction method, RPCE had the advantage of simultaneous determination of nitrate and nitrite, could be used in the presence of various metallic ions that normally interfere in cadmium reduction, and decreased detection limits by a factor of 10

  14. MRI investigation of water-oil two phase flow in straight capillary, bifurcate channel and monolayered glass bead pack.

    Science.gov (United States)

    Liu, Yu; Jiang, Lanlan; Zhu, Ningjun; Zhao, Yuechao; Zhang, Yi; Wang, Dayong; Yang, Mingjun; Zhao, Jiafei; Song, Yongchen

    2015-09-01

    The study of immiscible fluid displacement between aqueous-phase liquids and non-aqueous-phase liquids in porous media is of great importance to oil recovery, groundwater contamination, and underground pollutant migration. Moreover, the attendant viscous, capillary, and gravitational forces are essential to describing the two-phase flows. In this study, magnetic resonance imaging was used to experimentally examine the detailed effects of the viscous, capillary, and gravitational forces on water-oil flows through a vertical straight capillary, bifurcate channel, and monolayered glass-bead pack. Water flooding experiments were performed at atmospheric pressure and 37.8°C, and the evolution of the distribution and saturation of the oil as well as the characteristics of the two-phase flow were investigated and analyzed. The results showed that the flow paths, i.e., the fingers of the displacing phase, during the immiscible displacement in the porous medium were determined by the viscous, capillary, and gravitational forces as well as the sizes of the pores and throats. The experimental results afford a fundamental understanding of immiscible fluid displacement in a porous medium. PMID:25940392

  15. Environmental water monitoring by capillary electrophoresis and result comparison with solvent chemistry techniques.

    Science.gov (United States)

    Sirén, Heli; Väntsi, Sirpa

    2002-05-24

    The aim of this work was to determine inorganic ions from natural waters by capillary electrophoresis (CE) and to compare the results obtained with those measured with conventional solvent chemistry techniques. The project was part of a larger CE study, during which we measured inorganic ions from some lake and river systems and groundwaters in Southern Finland. Results obtained from contaminated Finnish waters were compared with samples from the River Rhine in the Düsseldorf area. Two CE methods were used for analysis: one for determination of chloride, sulfate, nitrite and nitrate at pH 7.7 and the other for ammonium, potassium, calcium, sodium and magnesium at pH 3.6, both methods using identification based on indirect UV detection. Two separation methods were used in order to prevent complex formation of metals with sulfate, hydroxide and decomposed organic matter present in the environmental samples. On the basis of the CE studies dilution was needed for those samples having more than 100 mg/l of sulfate, chloride, calcium and sodium. On average, the natural waters in the study contained ammonium, magnesium, sodium, potassium and calcium below 0.3, 20, 200, 20, and 200 mg/l, respectively. The concentrations of chloride, sulfate, nitrite and nitrate were below 20, 100, 10, and 10 mg/l, respectively. Correlation of the CE results with those acquired by titration, atomic absorption spectrometry, ion chromatography and flow injection analysis were obtained; R2 values for the comparison tests varied from 0.8816 to 0.9994 depending on the ion. The repeatabilities of the anion and cation CE methods were tested using laboratory-made reference sample mixtures with high and low salt concentration. PMID:12102308

  16. Capillary transport of water through textile-reinforced concrete applied in repairing and/or strengthening cracked RC structures

    Energy Technology Data Exchange (ETDEWEB)

    Lieboldt, M.; Mechtcherine, V., E-mail: mechtcherine@tu-dresden.de

    2013-10-15

    The use of textile-reinforced concrete (TRC) has great potential for innovative solutions in repairing, protecting, and strengthening concrete and RC structures. The article at hand reports on an investigation on composite concrete specimens made of cracked ordinary concrete as substrate and textile-reinforced concrete (TRC) as a cover layer for its strengthening and repair. The TRC cover layer was assessed with regard to its effectiveness as a protective layer against the ingress of water through capillary action. Since in real applications such TRC layers may be cracked or presumed to be so, thereby activating the load-carrying function of the textile reinforcement, the TRC layer was cracked for purposes of this study. The water transport in the cracked ordinary concrete specimens without the TRC layer was used as a reference. Gravimetric measurements and neutron radiography served as the testing techniques. In ordinary concrete quick and deep ingress of water through relatively wide macro-cracks of approximately 100 μm width, followed by transport through the capillary pore system, caused saturation of large areas in a rather short time. TRC applied to the RC surface reduced the ingress of water to a large extent. Its small crack widths of 15 to 20 μm changed suction behaviour fundamentally. In the cracked substrate of ordinary concrete, capillary suction was prevented, and transport through the pore system of the matrix became the prevailing transport mechanism of capillary action. Not only was the mechanism altered, but the transport of water deep into inner regions was markedly retarded as well.

  17. Capillary transport of water through textile-reinforced concrete applied in repairing and/or strengthening cracked RC structures

    International Nuclear Information System (INIS)

    The use of textile-reinforced concrete (TRC) has great potential for innovative solutions in repairing, protecting, and strengthening concrete and RC structures. The article at hand reports on an investigation on composite concrete specimens made of cracked ordinary concrete as substrate and textile-reinforced concrete (TRC) as a cover layer for its strengthening and repair. The TRC cover layer was assessed with regard to its effectiveness as a protective layer against the ingress of water through capillary action. Since in real applications such TRC layers may be cracked or presumed to be so, thereby activating the load-carrying function of the textile reinforcement, the TRC layer was cracked for purposes of this study. The water transport in the cracked ordinary concrete specimens without the TRC layer was used as a reference. Gravimetric measurements and neutron radiography served as the testing techniques. In ordinary concrete quick and deep ingress of water through relatively wide macro-cracks of approximately 100 μm width, followed by transport through the capillary pore system, caused saturation of large areas in a rather short time. TRC applied to the RC surface reduced the ingress of water to a large extent. Its small crack widths of 15 to 20 μm changed suction behaviour fundamentally. In the cracked substrate of ordinary concrete, capillary suction was prevented, and transport through the pore system of the matrix became the prevailing transport mechanism of capillary action. Not only was the mechanism altered, but the transport of water deep into inner regions was markedly retarded as well

  18. Growth of gravity-capillary waves in countercurrent air/water turbulence

    Science.gov (United States)

    Soldati, Alfredo; Zonta, Francesco; Onorato, Miguel

    2015-11-01

    We use Direct Numerical Simulation (DNS) of the Navier Stokes equations to analyze the dynamics of the interface between air and water when both phases are driven by opposite pressure gradients (countercurrent configuration). The Reynolds number (Reτ), the Weber number (We) and the Froude number (Fr) fully describe the physical problem. We examine the problem of the transient growth of interface waves for different combinations of physical parameters. Keeping Reτ constant and varying We and Fr , we show that, in the initial stages of the wave generation process, the amplitude of the interface elevation η grows in time as η ~t 2 / 5 . Wavenumber spectra, E (kx) , of the surface elevation in the capillary range are in good agreement with the prediction of the Wave Turbulence Theory. Finally, the wave-induced modification of the average wind and current velocity profiles will be addressed. Support from Regione Autonoma Friuli Venezia Giulia under grant PAR FSC 2007/2013 is gratefully acknowledged.

  19. A Capillary Electrophoresis Detection Scheme for Water-soluble Vitamins Based on Luminol - BrO- Chemiluminescence System

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A novel chemiluminescence detection scheme has been developed for detecting water-soluble vitamins following capillary electrophoresis (CE) separation. This detection was based on the inhibitory effect of vitamins on the CL reaction between luminol and BrO- in basic aqueous solution. Detection of vitamins was accomplished with a borate-based background electrolyte at pH 9.2. The luminol was used as a component of the separation carrier electrolyte.

  20. Surface Tension of Supercooled Water Down to -21°C Measured within a Horizontal Capillary Tube

    Czech Academy of Sciences Publication Activity Database

    Vinš, Václav; Hošek, Jan; Hykl, Jiří; Hrubý, Jan

    Boulder Colorado: National Institute of Standards and Technology, 2015. PaperID 2611. [Symposium on Thermophysical Properties /19./. 21.06.2015-26.06.2015, Boulder Colorado] R&D Projects: GA MŠk LG13056; GA ČR GJ15-07129Y Institutional support: RVO:61388998 Keywords : capillary tube * horizontal measurement * supercooled water Subject RIV: BJ - Thermodynamics http://thermosymposium.nist.gov/pdf/Abstract_2611.pdf ; http://thermosymposium.nist.gov/program.html

  1. Confirmation of phorate, terbufos, and their sulfoxides and sulfones in water by capillary gas chromatography/chemical ionization mass spectrometry

    International Nuclear Information System (INIS)

    A gas chromatographic/mass spectrometric method capable of confirming phorate, terbufos, their sulfoxides, and sulfones in water is reported. Parents and their metabolites are separated in less than 5 min using a short capillary GC column and high carrier gas linear velocities. Positive ion chemical ionization mass spectrometry generates (M + H) ions indicative of the different molecular weights of the analytes and at least one confirmatory fragment ion for each analyte. Residues have been qualitatively confirmed at the 1 ppb level in fortified water samples from a variety of sources. Apparent residues in control water were less than 0.1 ppb

  2. Table-top water-window soft X-ray microscope using a Z-pinching capillary discharge source

    Science.gov (United States)

    Nawaz, M. F.; Nevrkla, M.; Jancarek, A.; Torrisi, A.; Parkman, T.; Turnova, J.; Stolcova, L.; Vrbova, M.; Limpouch, J.; Pina, L.; Wachulak, P.

    2016-07-01

    The development and demonstration of a table-top transmission soft X-ray (SXR) microscope, using a laboratory incoherent capillary discharge source has been carried out. This Z-pinching capillary discharge water-window SXR source, is a first of its kind to be used for high spatial resolution microscopy at λ = 2.88 nm (430 eV) . A grazing incidence ellipsoidal condenser mirror is used for focusing of the SXR radiation at the sample plane. The Fresnel zone plate objective lens is used for imaging of the sample onto a back-illuminated (BI) CCD camera. The achieved half-pitch spatial resolution of the microscope approaches 100 nm, as demonstrated by the knife-edge test. Details about the source, and the construction of the microscope are presented and discussed. Additionally, the SXR images of various samples, proving applicability of such microscope for observation of objects in the nanoscale, are shown.

  3. Application of capillary electrophoresis to anion speciation in soil water extracts: 2. Arsenic

    Energy Technology Data Exchange (ETDEWEB)

    Naidu, R.; Smith, J.; McLaren, R.G.; Stevens, D.P.; Sumner, M.E.; Jackson, P.E.

    2000-02-01

    A method has been developed for the speciation of arsenic (AsO{sub 2}{sup {minus}}, AsO{sub 4}{sup 3{minus}}, and dimethylarsinic [DMA]) in natural soil solutions from contaminated sites in Australia. The separation of these anions was achieved by capillary zone electrophoresis (CZE) using a fused silica capillary with a basic chromate buffer and on-column indirect UV detection at 254 nm. Method parameters, such as electrolyte pH, run voltage, and capillary temperature were studied in order to establish suitable analytical conditions. The ideal separation for As(III) and DMA was achieved with a buffer pH of 8.0, a run voltage of 25 kV, and a capillary temperature of 30 C. Under these conditions, As(V) and orthophosphate ions comigrated. However, the use of a chromate buffer at pH 10, a run voltage of 20 kV, and capillary temperature of 20 C led to complete separation of As(V) and phosphate peaks. Results of these investigations together with recovery test data suggest that separation of the As species from soil solutions can be achieved in less than 5 min with detection limits of 0.50, 0.10, and 0.10 mg L{sup {minus}1} for As(III), As(V), and DMA, respectively.

  4. Experimental study of a water thermo-capillary loop; Etude experimentale d`une boucle thermocapillaire a eau

    Energy Technology Data Exchange (ETDEWEB)

    Lefriec, C.; Alexandre, A. [Ecole Nationale Superieure de Mecanique et d`Aerotechnique (ENSMA), 86 - Poitiers (France)

    1996-12-31

    This paper presents a bench scale experiment of a water thermo-capillary loop which allows to improve the understanding of its functioning mechanisms thanks to the internal visualisation of each component using transparent walls. The advantages of water are its non-toxicity, its high chemical compatibility with several materials and its low functioning pressure. The experimental device is presented and the functioning regimes of each component is analyzed: condenser (flow visualization, influence of tilt), evaporator (quality of heat exchange between teeth and porous medium, bubbles, heat exchange coefficient). (J.S.)

  5. Analysis of water from the Space Shuttle and Mir Space Station by ion chromatography and capillary electrophoresis

    Science.gov (United States)

    Orta, D.; Mudgett, P. D.; Ding, L.; Drybread, M.; Schultz, J. R.; Sauer, R. L.

    1998-01-01

    Drinking water and condensate samples collected from the US Space Shuttle and the Russian Mir Space Station are analyzed routinely at the NASA-Johnson Space Center as part of an ongoing effort to verify water quality and monitor the environment of the spacecraft. Water quality monitoring is particularly important for the Mir water supply because approximately half of the water consumed is recovered from humidity condensate. Drinking water on Shuttle is derived from the fuel cells. Because there is little equipment on board the spacecraft for monitoring the water quality, samples collected by the crew are transported to Earth on Shuttle or Soyuz vehicles, and analyzed exhaustively. As part of the test battery, anions and cations are measured by ion chromatography, and carboxylates and amines by capillary electrophoresis. Analytical data from Shuttle water samples collected before and after several missions, and Mir condensate and potable recovered water samples representing several recent missions are presented and discussed. Results show that Shuttle water is of distilled quality, and Mir recovered water contains various levels of minerals imparted during the recovery processes as designed. Organic ions are rarely detected in potable water samples, but were present in humidity condensate samples.

  6. A glass capillary based microfluidic electromembrane extraction of basic degradation products of nitrogen mustard and VX from water.

    Science.gov (United States)

    Tak, Vijay; Kabra, Ankur; Pardasani, Deepak; Goud, D Raghavender; Jain, Rajeev; Dubey, D K

    2015-12-24

    In this work, a glass capillary based microfluidic electromembrane extraction (μ-EME) was demonstrated for the first time. The device was made by connecting an auxillary borosilicate glass tubing (O.D. 3mm, I.D. 2mm) perpendicular to main borosilicate glass capillary just below one end of the capillary (O.D. 8mm, I.D. 1.2mm). It generated the distorted T-shaped device with inlet '1' and inlet '2' for the introduction of sample and acceptor solutions, respectively. At one end of this device (inlet '2'), a microsyringe containing acceptor solution along with hollow fiber (O.D. 1000μm) was introduced. This configuration creates the micro-channel between inner wall of glass capillary and outer surface of hollow fiber. Sample solution was pumped into the system through another end of glass capillary (inlet '1'), with a micro-syringe pump. The sample was in direct contact with the supported liquid membrane (SLM), consisted of 20% (w/w) di-(2-ethylhexyl)phosphate in 2-nitrophenyl octyl ether immobilized in the pores of the hollow fiber. In the lumen of the hollow fiber, the acceptor phase was present. The driving force for extraction was direct current (DC) electrical potential sustained over the SLM. Highly polar (logP=-2.5 to 1.4) basic degradation products of nitrogen mustard and VX were selected as model analytes. The influence of chemical composition of SLM, extraction time, voltage and pH of donor and acceptor phase were investigated. The model analytes were extracted from 10μL of pure water with recoveries ranging from 15.7 to 99.7% just after 3min of operation time. Under optimized conditions, good limits of detection (2-50ngmL(-1)), linearity (from 5-1000 to 100-1000ngmL(-1)), and repeatability (RSDs below 11.9%, n=3) were achieved. Applicability of the proposed μ-EME was proved by recovering triethanolamine (31.3%) from 10μL of five times diluted original water sample provided by the Organization for the Prohibition of Chemical Weapons during 28th official

  7. Separation of methicillin-resistant from methicillin-susceptible staphylococcus aureus by electrophoretic methods in fused silica capillaries etched with supercritical water

    Czech Academy of Sciences Publication Activity Database

    Horká, Marie; Karásek, Pavel; Růžička, F.; Dvořáčková, M.; Sittová, M.; Roth, Michal

    2014-01-01

    Roč. 86, č. 19 (2014), s. 9701-9708. ISSN 0003-2700 R&D Projects: GA MV VG20112015021; GA ČR(CZ) GAP106/12/0522 Institutional support: RVO:68081715 Keywords : Staphylococcus aureus strains * capillary zone electrophoresis * supercritical water-treated capillary Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 5.636, year: 2014 http://hdl.handle.net/11104/0236865

  8. Determination of zeta-potential, charge, and number of organic ligands on the surface of water soluble quantum dots by capillary electrophoresis

    OpenAIRE

    Voráčová, I. (Ivona); Klepárník, K. (Karel); Lišková, M. (Marcela); Foret, F

    2015-01-01

    The number of charges and/or organic ligands covalently attached to the surface of CdTe quantum dot nanoparticles has been determined from their electrophoretic mobilities measured in capillaries filled with free electrolyte buffers. Three sizes of water soluble CdTe quantum dots with 3-mercaptopropionic and thioglycolic acids as surface ligands were prepared. Their electrophoretic mobilities in different pH and ionic strength values of separation buffers were measured by capillary elect...

  9. Determination of alkyllead salts in water and whole eggs by capillary column gas chromatography with electron capture detection

    Energy Technology Data Exchange (ETDEWEB)

    Forsyth, D.S.; Marshall, W.D.

    1983-11-01

    Alkyllead salts (R/sub 3/Pb/sup +/ and R/sub 2/Pb/sup 2 +/, R = Methyl or Ethyl) are recovered from water or whole eggs by complexometric extraction with dithizone. The dithizonates are phenylated and speciated by capillary column gas chromatography with electron capture detection. The method is sensitive to low parts per billion levels of lead salts in 2.5 g egg homogenate. At these levels methyllead salts (but not ethyllead salts) interact strongly with the sample matrix. Treatment of the matrix with lipases and proteases releases them. 4 figures, 3 tables.

  10. Temperature-dependent capillary forces at nano-contacts for estimating the heat conduction through a water meniscus

    Science.gov (United States)

    Assy, Ali; Gomès, Séverine

    2015-09-01

    The temperature dependence of the capillary forces at nano-sized contacts is investigated. Two different resistive scanning thermal microscopy (SThM) nanoprobes are used in this study. Measurements of the capillary forces are reported as a function of the probe temperature on hydrophilic samples of different thermal properties. These forces appear to be largely reduced for probe temperatures larger than a threshold temperature, where the value depends on the sample thermal conductance. This could pave the way to an alternative solution to reduce the stiction in nano/ micro-electromechanical (NEMS/MEMS) devices. The dimensions of the water meniscus at the probe-sample contact were then estimated. Moreover, these results help the evaluation of thermal conductance through the water meniscus. It is found, through this work, that the values of the thermal conductance through the water meniscus can represent 6% of those of the contact thermal conductance in the case of the KNT probe (from Kelvin nanotechnology). These values can be equal to 4% of those of thermal conduction in the cantilever-sample air gap in the case of a doped-silicon probe.

  11. Temperature-dependent capillary forces at nano-contacts for estimating the heat conduction through a water meniscus.

    Science.gov (United States)

    Assy, Ali; Gomès, Séverine

    2015-09-01

    The temperature dependence of the capillary forces at nano-sized contacts is investigated. Two different resistive scanning thermal microscopy (SThM) nanoprobes are used in this study. Measurements of the capillary forces are reported as a function of the probe temperature on hydrophilic samples of different thermal properties. These forces appear to be largely reduced for probe temperatures larger than a threshold temperature, where the value depends on the sample thermal conductance. This could pave the way to an alternative solution to reduce the stiction in nano/ micro-electromechanical (NEMS/MEMS) devices. The dimensions of the water meniscus at the probe-sample contact were then estimated. Moreover, these results help the evaluation of thermal conductance through the water meniscus. It is found, through this work, that the values of the thermal conductance through the water meniscus can represent 6% of those of the contact thermal conductance in the case of the KNT probe (from Kelvin nanotechnology). These values can be equal to 4% of those of thermal conduction in the cantilever-sample air gap in the case of a doped-silicon probe. PMID:26245265

  12. Analyses of Phytohormones in Coconut (Cocos Nucifera L.) Water Using Capillary Electrophoresis-Tandem Mass Spectrometry

    OpenAIRE

    Swee Ngin Tan; Jean Wan Hong Yong; Liya Ge

    2014-01-01

    Capillary electrophoresis (CE) coupled with mass spectrometry (MS) or tandem mass spectrometry (MS/MS) is reported as an alternative and potentially useful method for the simultaneous analysis of various classes of phytohormones with diversified structures, including indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), abscisic acid (ABA), gibberellic acid (GA), zeatin (Z), N6-benzyladenine (BA), α-naphthaleneacetic acid (NAA) and 2,4-dichlorophenoxyacetic acid (2,4-D). The key to the CE-...

  13. Surface Tension of Supercooled Water Determined by Using a Counterpressure Capillary Rise Method

    Czech Academy of Sciences Publication Activity Database

    Vinš, Václav; Fransen, M. A. L. J.; Hykl, Jiří; Hrubý, Jan

    2015-01-01

    Roč. 119, č. 17 (2015), s. 5567-5575. ISSN 1520-6106 R&D Projects: GA MŠk LG13056; GA ČR GJ15-07129Y Institutional support: RVO:61388998 Keywords : capillary tube * interfacial tension * metastable liquid * supercooled liquid Subject RIV: BJ - Thermodynamics Impact factor: 3.302, year: 2014 http://pubs.acs.org/doi/abs/10.1021/acs.jpcb.5b00545

  14. Capillary trapping mechanism in strongly water wet systems: Comparison between experiment and percolation theory

    Science.gov (United States)

    Geistlinger, Helmut; Mohammadian, Sadjad

    2015-05-01

    To understand capillary trapping mechanism, we conduct a real Monte-Carlo experiment by using packed glass beads with nearly the same pore size distribution, but different stochastic realizations. We study gas phase trapping during imbibition for capillary numbers from 2 × 10-7 to 10-6 using X-ray micro tomography and compare the experimental results with predictions from percolation theory. We found excellent agreement. Percolation theory explains (i) that the capillary desaturation curves are not dependent on flow rate, (ii) the linear dependence of the total gas surface on gas saturation that is a direct consequence of the linear relationship between cluster surface area and cluster volume, which is a prediction from percolation theory for large finite clusters, (iii) the power-like cluster size distribution with an exponent τexp = 2.15 that only deviates by 2% from the theoretical one (τtheor = 2.19), and (iv) that the maximal z-extension of trapped large gas cluster is described by the cut-off correlation length ξB (B - bond number).

  15. The Interface Conditions for Pressures at Oil-water Flood Front in the Porous Media Considering Capillary Pressure

    CERN Document Server

    Peng, Xiaolong; Du, Zhimin

    2016-01-01

    Flood front is the jump interface where fluids distribute discontinuously, whose interface condition is the theoretical basis of a mathematical model of the multiphase flow in porous medium. The conventional interface condition at the jump interface is expressed as the continuous Darcy velocity and fluid pressure (named CPVCM). This paper has inspected it via the studying the water-oil displacement in one dimensional reservoir with considering capillary pressure but ignoring the compressibility and gravity. It is proved theoretically that the total Darcy velocity and total pressure (defined by Antoncev etc.), instead of the Darcy velocities and pressures of water and oil, are continuous at the flood front without considering the compressibility of fluid and porous media. After that, new interface conditions for the pressures and Darcy velocity of each fluid are established, which are collectively named as Jump Pressures and Velocities Conditions Model (JPVCM) because the model has shown the jump pressures and...

  16. Determination of Aniline and Its Derivatives in Environmental Water by Capillary Electrophoresis with On-Line Concentration

    Directory of Open Access Journals (Sweden)

    Jianzhi Sun

    2012-06-01

    Full Text Available This paper describes a simple, sensitive and environmentally benign method for the direct determination of aniline and its derivatives in environmental water samples by capillary zone electrophoresis (CZE with field-enhanced sample injection. The parameters that influenced the enhancement and separation efficiencies were investigated. Surprisingly, under the optimized conditions, two linear ranges for the calibration plot, 1–50 ng/mL and 50–1000 ng/mL (R > 0.998, were obtained. The detection limit was in the range of 0.29–0.43 ng/mL. To eliminate the effect of the real sample matrix on the stacking efficiency, the standard addition method was applied to the analysis of water samples from local rivers.

  17. On the Transition from Bulk to Ordered Form of Water: A Theoretical Model to Calculate Adhesion Force Due to Capillary and van der Waals Interaction

    OpenAIRE

    Yaqoob, M.A.; de, Rooij, R.; Schipper, D.J.

    2013-01-01

    The adhesion force due to capillary interaction between two hydrophilic surfaces is strongly dependent on the partial pressure of water and is often calculated using the Kelvin equation. The validity of the Kelvin equation is questionable at low relative humidity (RH) of water, like in high vacuum and dry nitrogen environments, where water is only present as layers of several molecules thick at the surfaces. A model from ordered to bulk form of water has been developed using the Brunauer, Emm...

  18. Efficiency of hydrogen peroxide production by ac capillary discharge in water solution

    International Nuclear Information System (INIS)

    Efficiency of hydrogen peroxide production by an ac driven underwater capillary discharge was investigated quantitatively. The concentration of formed hydrogen peroxide was measured by a colorimetric method using a specific reaction between H2O2 and a titanium reagent. The amount of formed H2O2 increases linearly during the first hour of the discharge duration. The initial rate and corresponding total energy yield of H2O2 formation by the capillary discharge were determined for initial electrical conductivity of aqueous solution in the range of 100-500 μS cm-1 and average applied power in the range 30-90 W. It comes out that the total energy yield of H2O2 formation, derived from the initial rate of H2O2 formation and the average applied power, increases linearly with average applied power and that solution conductivity has only a negligible effect on the energy yield. A maximum total energy yield of H2O2 formation of 0.9 g kWh-1 was obtained for a 500 μS cm-1 aqueous solution

  19. Effect of capillary number on the oil recovery using oil-water emulsion injection in core flooding experiments

    Energy Technology Data Exchange (ETDEWEB)

    Guillen Nunez, Victor Raul; Carvalho, Marcio da Silveira [Pontifical Catholic University of Rio de Janeiro (PUC-Rio), RJ (Brazil). Dept. of Mechanical Engineering], E-mail: msn@puc-rio.br; Basante, Vladimir Alvarado [University of Wyoming, Laramie, WY (United States). Dept. of Chemical/Petroleum Engineering], E-mail: valvard@uwyo.edu

    2010-07-01

    The Water injection flooding is a common method to improve reservoir sweep and pressure maintenance. The heavy-oil-recovery efficiency is in part limited by the high water-to-oil mobility ratio. Several enhanced oil recovery methods are being developed as more efficient alternatives to water flooding. Dispersion injection, in particular oil-water emulsion injection, has been tried with relative success as an enhanced oil recovery method, but the technique is not fully developed or understood. If emulsion injection proves to be an effective EOR method, its use would bring the added benefit of disposing produced water with small oil content that could be modified to serve as the injected oil-water emulsion. The use of such methods requires a detailed analysis of the different flow regimes of emulsions through the porous space of a reservoir rock. If the drop size of the disperse phase is of the same order of magnitude as the pore size, the drops may agglomerate and partially block water flow through pores. This flow regime may be used to control the mobility of the injected liquid, leading to higher recovery factor. We have shown in recent experiments of oil displacement in a sandstone core that, the oil recovery factor could be raised from approximately 40 %, obtained with water injection only, up to approximately 75 % by alternating water and emulsion injection. Although these results clearly show the improvement in the recovery factor, the mechanisms responsible for the phenomenon have not been clearly elucidated. In this work, two sandstone cores were used to demonstrate the effect of flow rate (capillary number) on the mobility control by emulsion injection. Figure 1 shows a schematic representation of the experiment set-up. The experiments show that raising the flow rate by a factor of 10 (0.03 ml/min to 0.3 ml/min), the oil recovered factor decreases considerably. (author)

  20. Subcritical water extraction of alkaloids in Sophora flavescens Ait. and determination by capillary electrophoresis with field-amplified sample stacking.

    Science.gov (United States)

    Wang, Haiyan; Lu, Yuchao; Chen, Jie; Li, Junchao; Liu, Shuhui

    2012-01-25

    The extraction and determination of cytisine, sophocarpine, matrine, sophoridine and oxymatrine in Sophora flavescens Ait. were performed using subcritical water extraction and capillary electrophoresis with field-amplified sample stacking. The effects of extraction temperature, pressure, time and cycle number on the extraction yields were investigated systematically for accelerated solvent extraction with ethanol (ASE) and accelerated solvent extraction with water (subcritical water extraction, SWE). The extraction yields obtained using SWE, ASE, water ultrasonic extraction and chloroform soaking extraction methods were compared. The electrophoresis separation buffer was monosodium phosphate (pH 3.0; 110 mM)-isopropanol (85:15, v/v). The effect of phosphoric acid added to the sample matrix on the reproducibility of the peak heights of the analytes was also examined. Cytisine, sophoridine and oxymatrine showed good linearity (R(2)>0.999) within 0.125-4.0 μg/mL, and sophocarpine and matrine exhibited good linearity (R(2)>0.998) within 0.0625-2.0 μg/mL, with the detection limits in the range of 0.004-0.0013 μg/mL. The five alkaloid contents in medicinal plants from different sources and Sophora instant granule were determined and compared. PMID:21996061

  1. Determination of low molecular weight organic acids in soil, plants, and water by capillary zone electrophoresis.

    Science.gov (United States)

    Li, Ying-Hui; Huang, Bi-Xia; Shan, Xiao-Quan

    2003-03-01

    Determination of low molecular weight organic acids in soils and plants by capillary zone electrophoresis was accomplished using a phthalate buffer and indirect UV detection mode. The influence of some crucial parameters, such as pH, buffer concentration and surfactant were investigated. A good separation of seven organic acids was achieved within 5 min using an electrolyte containing 15 mmol L(-1) potassium hydrogen phthalate, 0.5 mmol L(-1) myristyltrimethylammonium bromide (MTAB), and 5% methanol (MeOH) (v/v) at pH 5.60, separation voltage -20 kV, and temperature 25 degrees C. The relative standard deviation (n=5) of the method was found to be in range 0.18-0.56% for migration time and 3.2-4.8% for peak area. The limit of detection ranged between 0.5 micro mol L(-1) to 6 micro mol L(-1) at a signal-to-noise ratio of 3. The recovery of standard organic acids added to real samples ranged from 87 to 119%. This method was simple, rapid and reproducible, and could be applied to the simultaneous determination of organic acids in environmental samples. PMID:12664177

  2. How Capillary Rafts Sink

    CERN Document Server

    Protiere, S; Aristoff, J; Stone, H

    2010-01-01

    We present a fluid dynamics video showing how capillary rafts sink. Small objects trapped at an interface are very common in Nature (insects walking on water, ant rafts, bubbles or pollen at the water-air interface, membranes...) and are found in many multiphase industrial processes. Thanks to Archimedes principle we can easily predict whether an object sinks or floats. But what happens when several small particles are placed at an interface between two fluids. In this case surface tension also plays an important role. These particles self-assemble by capillarity and thus form what we call a "capillary raft". We show how such capillary rafts sink for varying sizes of particles and define how this parameter affects the sinking process.

  3. Multiresidue determination of penicillins in environmental waters and chicken muscle samples by means of capillary electrophoresis-tandem mass spectrometry.

    Science.gov (United States)

    Bailón-Pérez, M Isabel; García-Campaña, Ana M; del Olmo Iruela, Monsalud; Cruces-Blanco, Carmen; Gámiz Gracia, Laura

    2009-05-01

    A new analytical method based on CZE coupled with tandem MS detection (CE-MS/MS) has been developed for the simultaneous determination of nine penicillins of human and veterinary use (nafcillin, dicloxacillin, cloxacillin, oxacillin, ampicillin, penicillin G, amoxicillin, penicillin V and piperacillin), whose levels are regulated by the EU Council regulation No. 2377/90 in animal edible tissues. CE separation conditions, sheath liquid composition and electrospray parameters have been carefully optimized to reach high sensitivity and precision. Separation was carried out in a 96 cm total length fused-silica capillary (50 microm id, 360 microm od) using 60 mM ammonium acetate at pH 6.0 as running buffer. Lomefloxacin was used as internal standard. MS/MS experiments were carried out using an IT as analyzer operating in multiple reaction monitoring mode to achieve the minimum number of identification points established by the 2002/657/EC European Decision. The use of an SPE procedure in two steps, combining Oasis hydrophilic-liphophilic balance and Alumina N cartridges provide a satisfactory preconcentration and clean up treatment for meat samples after extraction of the compounds with ACN. Only Oasis hydrophilic-liphophilic balance cartridges were necessary in water samples to obtain adequate recoveries. The method has been characterized for its use in meat and water samples, using matrix-matched calibrations. For chicken muscle samples, LODs between 8 and 12 microg/kg have been obtained, in all cases lower than the maximum residue limits permitted. For water samples LODs from 0.18 to 0.26 microg/L could ensure its satisfactory application in aquatic samples. PMID:19391147

  4. Capillary gas chromatography with atomic emission detection for determining chlorophenols in water and soil samples

    Energy Technology Data Exchange (ETDEWEB)

    Campillo, Natalia [Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, E-30071 Murcia (Spain); Aguinaga, Nerea [Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, E-30071 Murcia (Spain); Vinas, Pilar [Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, E-30071 Murcia (Spain); Lopez-Garcia, Ignacio [Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, E-30071 Murcia (Spain); Hernandez-Cordoba, Manuel [Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, E-30071 Murcia (Spain)]. E-mail: hcordoba@um.es

    2005-11-03

    A purge-and-trap preconcentration system coupled to a GC equipped with a microwave-induced atomic emission detector was used to determine 2-chlorophenol (2-CP), 2,4-dichlorophenol (2,4-DCP) and 2,4,6-trichlorophenol (2,4,6-TCP) in water and soil samples. The analytes were previously leached from the solid matrices into a 5% (w/v) sodium carbonate solution using an ultrasonic probe. It was necessary to acetylate the compounds before purging them from the aqueous medium, which, at the same time, improved their chromatographic separation. After selecting the optimal experimental conditions, the performance of the system was evaluated. Each chromatographic run took 26 min, including the purge time. Detection limits for 5 ml water samples ranged from 23 to 150 ng l{sup -1}, which is lower than the limits reached using the methods proposed by the US Environmental Pollution Agency (EPA) for chlorophenols in water. For soil samples, detection limits were calculated for 7 g samples, the resulting values ranging between 80 and 540 pg g{sup -1} for 2,4,6-TCP and 2-CP, respectively. The accuracy of the method was checked by analysing a certified reference soil, as well as fortified water and soil samples.

  5. Immiscible displacement of oil by water in consolidated porous media due to capillary imbibition under ultrasonic waves.

    Science.gov (United States)

    Hamida, Tarek; Babadagli, Tayfun

    2007-09-01

    Numerous studies done in the last four decades have demonstrated that acoustic stimulation may enhance recovery in oil reservoirs. This technology is not only technically feasible, but also serves as an economical, environmentally friendly alternative to currently accepted enhanced oil recovery (EOR) method. It requires low capital expenditure, and yields almost immediate improvement without any additional EOR agents. Despite a vast body of empirical and theoretical support, this method lacks sufficient understanding to make meaningful and consistent engineering predictions. This is in part due to the complex nature of the physical processes involved, as well as due to a shortage of fundamental/experimental research. Much of what the authors believe is happening within acoustically stimulated porous media is speculative and theoretical. This paper focuses on the effects of ultrasound on the interfacial forces between immiscible fluids. Capillary (spontaneous) imbibition of an aqueous phase into oil (or air)-saturated Berea sandstone and Indiana limestone samples experiments were conducted. Solutions of water, brine (15,000 and 150,000 ppm NaCl), anionic surfactant (sodium dodecyl diphenyloxide disulfonate), nonionic surfactant (alcohol ethoxylate) and polymer (xanthan gum) were prepared as the aqueous phase. Both counter-current and co-current geometries were tested. Due to the intrinsically unforced, gentle nature of the process, and their strong dependence on wettability, interfacial tension, viscosity and density, such experiments provide valuable insight into some of the governing mechanisms behind ultrasonic stimulation. PMID:17927413

  6. Screening determination of pharmaceutical pollutants in different water matrices using dual-channel capillary electrophoresis coupled with contactless conductivity detection.

    Science.gov (United States)

    Le, Minh Duc; Duong, Hong Anh; Nguyen, Manh Huy; Sáiz, Jorge; Pham, Hung Viet; Mai, Thanh Duc

    2016-11-01

    In this study, the employment of purpose-made dual-channel compact capillary electrophoresis (CE) instrument with capacitively coupled contactless conductivity detection (C(4)D) as a simple and inexpensive solution for screening determination of various pharmaceutical pollutants frequently occurring in surface water and hospital wastewater in Hanoi, Vietnam is reported. Five negatively charged pharmaceutically active compounds, namely ibuprofen, diclofenac, bezafibrate, ketoprofen and mefenamic acid were determined using the first channel whereas three positively charged ones, namely diphenhydramine, metoprolol and atenolol were determined with the second channel of the CE-C(4)D instrument. Two different background electrolytes (BGEs) were used in these two CE channels independently. The best detection limits achieved were in the range of 0.2-0.8mg/L without sample pre-concentration. Enrichment factors up to 200 were obtainable with the inclusion of a solid phase extraction step. Good agreement between results obtained from CE-C(4)D and those with the standard confirmation method (HPLC-DAD) was achieved, with correlation coefficients higher than 0.98. PMID:27591645

  7. Comparison of different capillary models to predict the hydraulic conductivity from the water retention curve

    OpenAIRE

    Touma, Jaoudat

    2008-01-01

    According to the analysis of Hillel and Gardner (1969) for steady infiltration, the hydraulic resistance of the soil surface crust, Rc (h) is determined by − hs,c / K (hs,c), hs,c (cm) being the water pressure at the interface soil/crust and K (hs,c) (cm/h), the soil hydraulic conductivity corresponding to hs,c. For steady infiltration, K (hs,c) is equal to the infiltration rate so that the knowledge of the hydraulic conductivity curve allow the determination of the crust resistance in this c...

  8. Capillary electrophoresis

    International Nuclear Information System (INIS)

    After a short historical introduction, the different modes of separation in capillary electrophoresis are explained and illustrated by practical examples. In addition, the most important parameters that can be used to optimize the selectivity of the separation, are discussed. (author) 27 refs.; 8 figs

  9. NMR study comparing capillary trapping in Berea sandstone of air, carbon dioxide, and supercritical carbon dioxide after imbibition of water

    Science.gov (United States)

    Prather, Cody A.; Bray, Joshua M.; Seymour, Joseph D.; Codd, Sarah L.

    2016-02-01

    Nuclear magnetic resonance (NMR) techniques were used to study the capillary trapping mechanisms relevant to carbon sequestration. Capillary trapping is an important mechanism in the initial trapping of supercritical CO2 in the pore structures of deep underground rock formations during the sequestration process. Capillary trapping is considered the most promising trapping option for carbon sequestration. NMR techniques noninvasively monitor the drainage and imbibition of air, CO2, and supercritical CO2 with DI H2O at low capillary numbers in a Berea sandstone rock core under conditions representative of a deep underground saline aquifer. Supercritical CO2 was found to have a lower residual nonwetting (NW) phase saturation than that of air and CO2. Supercritical CO2 behaves differently than gas phase air or CO2 and leads to a reduction in capillary trapping. NMR relaxometry data suggest that the NW phase, i.e., air, CO2, or supercritical CO2, is preferentially trapped in larger pores. This is consistent with snap-off conditions being more favorable in macroscale pores, as NW fluids minimize their contact area with the solid and hence prefer larger pores.

  10. Loss of Propiconazole and Its Four Stereoisomers from the Water Phase of Two Soil-Water Slurries as Measured by Capillary Electrophoresis

    Directory of Open Access Journals (Sweden)

    Rebecca D. Miller

    2011-08-01

    Full Text Available Propiconazole is a chiral fungicide used in agriculture for control of many fungal diseases on a variety of crops. This use provides opportunities for pollution of soil and, subsequently, groundwater. The rate of loss of propiconazole from the water phase of two different soil-water slurries spiked with the fungicide at 50 mg/L was followed under aerobic conditions over five months; the t1/2 was 45 and 51 days for the two soil slurries. To accurately assess environmental and human risk, it is necessary to analyze the separate stereoisomers of chiral pollutants, because it is known that for most such pollutants, both biotransformation and toxicity are likely to be stereoselective. Micellar electrokinetic chromatography (MEKC, the mode of capillary electrophoresis used for analysis of neutral chemicals, was used for analysis of the four propiconazole stereoisomers with time in the water phase of the slurries. MEKC resulted in baseline separation of all stereoisomers, while GC-MS using a chiral column gave only partial separation. The four stereoisomers of propiconazole were lost from the aqueous phase of the slurries at experimentally equivalent rates, i.e., there was very little, if any, stereoselectivity. No loss of propiconazole was observed from the autoclaved controls of either soil, indicating that the loss from active samples was most likely caused by aerobic biotansformation, with a possible contribution by sorption to the non-autoclaved active soils. MEKC is a powerful tool for separation of stereoisomers and can be used to study the fate and transformation kinetics of chiral pesticides in water and soil.

  11. Slope wavenumber spectrum models of capillary and capillary-gravity waves

    Institute of Scientific and Technical Information of China (English)

    贾永君; 张杰; 王岩峰

    2010-01-01

    Capillary and capillary-gravity waves possess a random character, and the slope wavenumber spectra of them can be used to represent mean distributions of wave energy with respect to spatial scale of variability. But simple and practical models of the slope wavenumber spectra have not been put forward so far. In this article, we address the accurate definition of the slope wavenumber spectra of water surface capillary and capillary-gravity waves. By combining the existing slope wavenumber models and using th...

  12. Ascensão capilar de água em substratos de coco e de pinus Capillary water rise in coconut and pine bark substrates

    Directory of Open Access Journals (Sweden)

    Carlos Vinicius Garcia Barreto

    2012-01-01

    Full Text Available O uso da irrigação por capilaridade na produção de mudas em viveiros pode trazer vantagens ao uso de água e sua utilização adequada requer o conhecimento da capacidade de ascensão de água no meio de crescimento das raízes, atributo pouco estudado. Para avaliar esta condição fundamental, este trabalho tem como objetivo avaliar a ascensão de água em substratos comerciais de coco e pinus, em dois padrões de tamanho de partículas e em duas condições de umidade, para indicar aquele que possua as melhores características físicas para aplicação na irrigação por capilaridade. Utilizou-se o método de ascensão capilar, com colunas desmontáveis de anéis preenchidas com substratos, avaliando-se os seguintes tempos de contato do fundo da coluna com a lâmina de água: 0,25, 0,5, 1, 2, 4, 8, 16 e 24 horas, com 10 repetições por tempo testado. Pelos resultados, observou-se que a maior ascensão capilar acumulada em 24 horas de ensaio foi obtida para os substratos de textura fina de coco e de pinus. Além disso, a hidrofobia do substrato de coco seco recomenda que as irrigações nesse material devem ter frequências maiores que substratos de pinus, evitando seu secamento. O substrato de pinus, por não apresentar esse comportamento, deve ter turnos de rega mais espaçados, principalmente sob textura fina. Devido à sua maior retenção de água e capacidade de elevação de água quando umedecido, o substrato fino de coco é mais adequado à irrigação por capilaridade em recipientes como tubetes.The capillary irrigation in nursery production could give advantages in water use and its correct application demands knowledge about capillary water rise through root growth media, an attribute poorly studied. This research had as objective to evaluate water capillary rise in commercial pine and coconut substrates for two particle size distributions and two moisture conditions, to indicate the substrate with the best physical

  13. Measurements of capillary pressure and electric permittivity of gas-water systems in porous media at elevated pressures: application to geological storage of CO2 in aquifers and wetting behavior in coal

    OpenAIRE

    Plug, W.-J.

    2007-01-01

    Sequestration of CO2 in aquifers and coal layers is a promising technique to reduce greenhouse gas emissions. Considering the reservoir properties, e.g. wettability, heterogeneity and the caprocks sealing capacity, the capillary pressure is an important measure to evaluate the efficiency, the success and the safety of storage applications. In this research, the capillary pressure behavior was investigated for the CO2-water system in quartz and coal. Measurements were conducted at pressures an...

  14. Separation, identification of methicillin-resistant from methicillin-susceptible Staphylococcus aureus in blood and their antimicrobial susceptibility by electrophoretic methods in fused silica capillaries etched with supercritical water

    Czech Academy of Sciences Publication Activity Database

    Horká, Marie; Vykydalová, Marie; Karásek, Pavel; Růžička, F.; Šesták, Jozef; Kahle, Vladislav; Roth, Michal

    2014. s. 508-508. [International Conference on Antimicrobial Research (ICAR) /3./. 01.10.2014-03.10.2014, Madrid] R&D Projects: GA MV VG20112015021; GA MV VG20102015023; GA ČR(CZ) GAP106/12/0522 Institutional support: RVO:68081715 Keywords : capillary electrophoretic techniques * capillaries etched with supercritical water * MSSA and MRSA separation * identification and antibiotic resistance Subject RIV: CB - Analytical Chemistry, Separation

  15. Peptide profilig of tryptic digests of water soluble proteins from Bacillus thuringiensis - transgenic and non-transgenic maize species by capillary zone electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Sázelová, Petra; Kašička, Václav; Ibanez, E.; Cifuentes, A.

    Praha: Institute of Organic Chemistry and Biochemistry AS CR, v. v. i, 2011 - (Slaninová, J.), s. 123-126. (Collection Symposium Series. 13). ISBN 978-80-86241-44-9. [Biologically Active Peptides /12./. Praha (CZ), 27.04.2011-29.04.2011] R&D Projects: GA ČR(CZ) GA203/08/1428; GA ČR(CZ) GA203/09/0675 Institutional research plan: CEZ:AV0Z40550506 Keywords : capillary zone electrophoresis * Bt-transgenic maize * water soluble proteins/peptides Subject RIV: CC - Organic Chemistry

  16. Fast and simple method for determination of iodide in human serum, sea water and cooking salt by capillary zone electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Pantůčková, Pavla; Křivánková, Ludmila

    2003, s. 172. [HPLC 2003. Symposium on High Performance Liquid Phase Separations and Related Techniques /27./. Nice (CZ), 15.06.2003-19.06.2003] R&D Projects: GA ČR GA203/02/0023; GA ČR GA203/01/0401; GA AV ČR IAA4031103 Institutional research plan: CEZ:AV0Z4031919 Keywords : capillary zone electrophoresis * determination of iodide * body fluids Subject RIV: CB - Analytical Chemistry, Separation

  17. Trace determination of tetracyclines in water samples by capillary zone electrophoresis combining off-line and on-line sample preconcentration.

    Science.gov (United States)

    Moreno-González, David; Lupión-Enríquez, Isabel; García-Campaña, Ana M

    2016-05-01

    In this work, a sensitive and reliable method using capillary zone electrophoresis with UV detection has been developed for trace determination of tetracycline antibiotics in river, spring, and ground waters. A solid-phase extraction method using Oasis HLB was applied for off-line preconcentration and cleanup of water samples, in combination with an on-line preconcentration methodology named large volume sample stacking with polarity switching. Different parameters were optimized in order to obtain an adequate separation combined with the highest sensitivity, using 75 mM sodium carbonate (pH 10) and 1 mM EDTA as separation buffer, applying a voltage of 25 kV at 25°C. The samples were injected in water at 1 bar for 1 min, applying then -25 kV and starting the sample stacking. Sample matrix removal from the capillary was controlled by monitoring the electric current (when the 95% of the separation current is reached the stacking process is completed). The applied voltage was then switched from negative to a positive value of 25 kV in order to separate the compounds. Under optimum conditions, sensitivity enhancement factors ranged from 303 to 428 for the studied compounds. The combination of both off-line and on-line preconcentration procedures provided a total sensitivity enhancement factor about 20 000, obtaining detection limits from 67 to 167 ng/L. The precision (intra- and interday), expressed as %RSD was below 12%. Recoveries obtained from river, spring, and ground waters ranged from 87 to 96%. Thus, this procedure is suitable for monitoring these compounds in water samples. PMID:27135309

  18. Impacts on oil recovery from capillary pressure and capillary heterogeneities

    Energy Technology Data Exchange (ETDEWEB)

    Bognoe, Thomas

    2008-07-01

    The main conclusions drawn from this thesis are; 7 scientific papers are published on a broad variety of subjects, and describes in detail the experiments and research treated in this thesis. Scientific research has been performed, investigating the subjects of capillary pressure and capillary heterogeneities from different angles. This thesis discusses the findings in this study and aims to illustrate the benefits of the results obtained for further development of other experiments, and/or even the industrial benefits in field development. The methods for wettability alteration have developed throughout the work. From producing heterogeneous wettability alterations, the methods have improved to giving both radial and lateral uniform wettability alterations, which also remains unaltered throughout the duration of the experimental work. The alteration of wettability is dependent on initial water saturation, flow rate, aging time and crude oil composition. Capillary pressure and relative permeability curves have been measured for core plugs at different wettabilities using conventional centrifuge methods. The trends observed are mostly consistent with theory. The production mechanisms of strongly and moderately water wet chalk has been investigated. At strongly water wet conditions in fractured chalk; the flow is governed by capillary forces, showing strong impact from the fractures. At moderately water wet conditions, the impact of the fractures are absent, and a dispersed water front is observed during the displacement. The oil recovery is about the same, at the two wettabilities. Fracture crossing mechanisms at the same wettability conditions have been mapped. And the observations are consistent with those of the water floods. During strongly water wet displacement, the fracture crossing is occurring once the inlet core has reached endpoint of spontaneous imbibition. At moderately water wet conditions the fracture crossing is less abrupt, and creation of wetting

  19. Unilateral NMR: a Noninvasive Tool for Monitoring In Situ the Effectiveness of Intervention to Reduce the Capillary Raise of Water in an Ancient Deteriorated Wall Painting

    Directory of Open Access Journals (Sweden)

    Valeria Di Tullio

    2012-01-01

    Full Text Available Portable unilateral NMR was used to quantitatively map in a fully noninvasive way the moisture distribution in an ancient deteriorated wall painting before and after an intervention to reduce the capillary raise of water through the wall. Maps obtained at a depth of 0.5 cm clearly showed the path of the capillary raise and indicated that, after the intervention, the moisture level was reduced. Maps obtained by measuring the first layers of the wall painting were affected by the critical environmental conditions of the second hypogeous level of St. Clement Basilica, Rome, and by the presence of salts efflorescence and encrustations on the surface of the wall painting. The morphology and the elemental composition of salts investigated by SEM-EDS indicated that efflorescences and encrustations were mostly constituted of gypsum and calcite. The presence of these salts is explained with the presence of high concentration of carbon dioxide and sulphur-rich particles due to pollution which, along with the high-moisture level and the extremely feeble air circulation, cause recarbonation and sulphation processes on the plaster surface.

  20. Capillary electrophoresis strategy to monitor the released and remaining nitric oxide from the same single cell using a specially designed water-soluble fluorescent probe.

    Science.gov (United States)

    Zhang, Zi-Xing; Guo, Xiao-Feng; Wang, Hong; Zhang, Hua-Shan

    2015-04-01

    Gasotransmitters including nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H2S) have attracted more and more attention in the past decades due to their unique signaling and functions. However, as a fundamental issue in the investigations of gasotransmitters, the cell membrane permeability and release behavior of them is controversial in reports because of the lack of an efficient approach to determine gasotransmitters released out of and remaining in the same cells simultaneously. To solve such problem, taking NO as representative, a robust and facile strategy has been reported based on a completely water-soluble fluorescent probe and a commercially available capillary electrophoresis system. A specially designed boron-dipyrromethene (BODIPY)-based fluorescent probe with two sulfonate groups, disodium 2,6-disulfonate-1,3,5,7-tetramethyl-8-(3',4'-diaminophenyl) difluoroboradiaza-s-indance (TMDSDAB), has been developed. As a turn-on fluorescent probe, TMDSDAB can react with NO promptly in aqueous media, and 540-fold enhancement of fluorescence is obtained. Using TMDSDAB, the trapping and quantification of NO released out of and remaining in the same single cell was achieved by capillary electrophoresis with laser-induced fluorescence detection. The limit of detection is 0.5 nM for NO. The proposed method has been applied to estimate the release behavior of single macrophages, and the results indicated that the cell membrane should be a barrier to NO diffusion. PMID:25707954

  1. Determination of diffusion coefficients of carbon dioxide in water between 268 and 473 K in a high-pressure capillary optical cell with in situ Raman spectroscopic measurements

    Science.gov (United States)

    Lu, Wanjun; Guo, Huirong; Chou, I.-Ming; Burruss, R.C.; Li, Lanlan

    2013-01-01

    Accurate values of diffusion coefficients for carbon dioxide in water and brine at reservoir conditions are essential to our understanding of transport behavior of carbon dioxide in subsurface pore space. However, the experimental data are limited to conditions at low temperatures and pressures. In this study, diffusive transfer of carbon dioxide in water at pressures up to 45 MPa and temperatures from 268 to 473 K was observed within an optical capillary cell via time-dependent Raman spectroscopy. Diffusion coefficients were estimated by the least-squares method for the measured variations in carbon dioxide concentration in the cell at various sample positions and time. At the constant pressure of 20 MPa, the measured diffusion coefficients of carbon dioxide in water increase with increasing temperature from 268 to 473 K. The relationship between diffusion coefficient of carbon dioxide in water [D(CO2) in m2/s] and temperature (T in K) was derived with Speedy–Angell power-law approach as: D(CO2)=D0[T/Ts-1]m where D0 = 13.942 × 10−9 m2/s, Ts = 227.0 K, and m = 1.7094. At constant temperature, diffusion coefficients of carbon dioxide in water decrease with pressure increase. However, this pressure effect is rather small (within a few percent).

  2. Effect of capillary pressure on water flooding development in low permeability reservoir%低渗透油藏毛管压力对水驱开发效果的影响

    Institute of Scientific and Technical Information of China (English)

    周能德

    2015-01-01

    The dynamic effect of capillary force during oil-water phase seepage in low permeability reservoir is crucial in two-phase flow mechanism and water flooding effect.The research on the rules helps to improve the water flooding development effect in this reservoir.This article presents the influential factors of dynamic effect of capillary force and dynamic capillary force,as well as impacts of dynamic capillary force,water injection intensity,well spacing on water flooding effects in low permeability reservoir.%低渗透油藏油水两相渗流过程中毛管力的动态效应是影响两相渗流机理及水驱油效果的重要因素,掌握其规律有助于提高这一特殊油藏的水驱开发效果。分析了低渗透油藏油水两相渗流中毛管力的动态效应以及动态毛管力的影响因素,以及动态毛管力、注水强度、井距等因素对低渗透油藏水驱油效果的影响。

  3. Non-Aqueous Capillary Electrophoresis

    Science.gov (United States)

    Szumski, Michał; Buszewski, Bogusław

    Non-aqueous capillary electrophoresis and capillary electrochromatography are special variants of these techniques. Here, organic solvents or their mixtures with or without dissolved electrolytes are used as separation buffer or mobile phase, respectively. The most important features of non-aqueous systems are: better solubility of more hydrophobic ionic substances (many natural products) than in water, much less current and Joule heating allows for using highly concentrated buffers and/or larger capillary internal diameters, polar interactions are enhanced in organic solvents which is often highly advantageous in chiral separation systems. This chapter presents most frequently used solvents, their properties, as well as shows pH* scale which is often used in non-aqueous systems.

  4. A rapid and simple capillary electrophoresis method for indirect determination of the biocide 2,2-dibromo-3-nitrilo-propionamide (DBNPA) in cooling waters.

    Science.gov (United States)

    Shiroma, Letícia S; Marques, Thaís T; Jesus, Dosil P

    2015-01-01

    A capillary zone electrophoresis (CE) method was developed for the determination of the biocide 2,2-dibromo-3-nitrilo-propionamide (DBNPA) in water used in cooling systems. The biocide is indirectly determined by CE measurement of the concentration of bromide ions produced by the reaction between the DBNPA and bisulfite. The relationship between the bromide peak areas and the DBNPA concentrations showed a good linearity and a coefficient of determination (R²) of 0.9997 in the evaluated concentration range of 0-75 μmol L⁻¹. The detection and quantification limits for DBNPA were 0.23 and 0.75 μmol L⁻¹, respectively. The proposed CE method was successfully applied for the analysis of samples of tap water and cooling water spiked with DBNPA. The intra-day and inter-day (intermediary) precisions were lower than 2.8 and 6.2%, respectively. The DBNPA concentrations measured by the CE method were compared to the values obtained by a spectrophotometric method and were found to agree well. PMID:25714644

  5. 毛细管气相色谱法测定废水中元素磷%Capillary Gas Chromatographic Determination of Element Phosphorus in Waste Water

    Institute of Scientific and Technical Information of China (English)

    李学章

    2012-01-01

    Split injection port, toluene extraction of samples, separation by capillary column, a nitrogen phosphorus detector (NPD) test, established by gas chromatography method for determination of element phosphorus in waste water. This method of checking out a concentration of 0.02 μg/L (compared to 25 : 1), coefficient of variation of 6.13 %, the recovery rate is 97.62 %-100.74 %. The method for high sensitivity, reproducibility is good, simple, rapid, and does not interfere with the determination of pollutants in water, apply to the determination of element phosphorus in waste water.%采用分流进样口,甲苯萃取水样,通过毛细管柱分离,以氮磷检测器(NPD)检测,建立了用气相色谱法测定废水中元素磷的方法。此方法的检出浓度为0.02μg/L(相比为25:1),变异系数为6.13%,回收率为97.62%~100.74%。该方法灵敏度高,再现性好,简便快速,水中各种污染物不干扰测定,适用于各种废水中元素磷的测定。

  6. [Trace analysis of heavy metal ions in electroplate waste water by capillary electrophoresis with visual offline sample stacking via moving neutralization boundary].

    Science.gov (United States)

    Fan, Yinping; Li, Shan; Fan, Liuyin; Cao, Chengxi

    2012-08-01

    A moving neutralization boundary (MNB) was developed as a novel model of visual offline sample stacking for the trace analysis of heavy metal ions (HMIs) by capillary zone electrophoresis (CZE). In the stacking system, the motion direction of MNB to cathode was used with 2.1 mmol/L HCl-98 mmol/L KCl-trace metal ions in the anodic solution and 4.0 mmol/L NaOH-96 mmol/L KCl in the cathodic solution. The voltage was constant at 180 V and the flow rate of the anolyte and catholyte was 1 mL/min. The metal ions in the gel after stacking were detected by capillary electrophoresis. The calibration curves showed good linear relationship (r > or = 0.998 5) in the concentration range used in the experiments. The pre-concentration factors were up to 80 - 150 and the limits of detection (LODs) were 0.163, 0.256, 0.077, 0.153, 0.203, 0.062 and 0.142 mg/L for Cu(II), Zn(II), Ni(II), Mg(II), Ca(II), Cr(III) and Fe(III), respectively, obviously lower than the national standards. The intra-day and inter-day assay precisions were good (the relative standard deviations (RSDs) less than 7.42%). Finally, the developed method has been successfully used for the stacking and the detection of heavy metal ions in electroplate waste water. PMID:23256387

  7. Tilting oil-water contact in the chalk of Tyra Field as interpreted from capillary pressure data

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke; Rana, M.A.

    2010-01-01

    logging data in the remaining wells. A westerly dipping oil–water contact was found from logging data. Comparison of the depth-wise trends in normalized water saturation among the different wells indicates a regional pattern: in the western side of the field, the trends correspond to a situation of...... imbibition, where the free water level overlies an interval of residual oil, whereas in the eastern part of the field, the depth-wise trends in normalized water saturation correspond to a situation of drainage. The free water level apparently dips to the east due either to hydrodynamic action or to pressure......The Tyra Field in the central North Sea is located in Palaeogene and Upper Cretaceous chalk. It contains a natural gas zone underlain by an oil leg. Based on analysis of logs and core data from ten wells drilled prior to the field being put into production, normalized water saturation depth...

  8. Use of gold nanoparticle-coated sorbent materials for the selective preconcentration of sulfonylurea herbicides in water samples and determination by capillary liquid chromatography.

    Science.gov (United States)

    Lerma-García, María Jesús; Simó-Alfonso, Ernesto F; Zougagh, Mohammed; Ríos, Angel

    2013-02-15

    Two new gold nanoparticle (NP) coated materials (silica supported on gold NP with and without ionic liquid) were synthesized for solid phase extraction of sulfonylurea herbicides (SUHs), such as bensulfuron-methyl (BSM), metsulfuron-methyl (MSM), pyrazosulfuron-methyl (PSM), thifensulfuron-methyl (TFM) and triasulfuron (TS), from water samples, followed by capillary liquid chromatography coupled to diode array detection (CLC-DAD). Several factors influencing the preconcentration efficiency of SUHs and its subsequent determination, such as pH of the sample, eluent and reusability of sorbents, have been investigated. Under the optimum conditions, the developed method allowed the determination of BSM, MSM, PSM, TFM and TS in a linear range between 0.05 and 1.00 μg mL(-1), with relative standard deviation values lower than 4.5% (n=10), in all cases. Detection limits within 0.002-0.009 μg mL(-1) range were achieved. The usefulness of the proposed method was demonstrated by the analysis of river water samples, in which recoveries between 83.9 and 105.0% were obtained. The Au-NP-ionic liquid-functionalized silica sorbent showed higher recoveries (selectivity) for the SUHs than the commercially available C18 sorbents. PMID:23598033

  9. Analysis of major histocompatibility complex class II gene in water voles using capillary electrophoresis-single stranded conformation polymorphism

    Czech Academy of Sciences Publication Activity Database

    Bryja, Josef; Galan, M.; Charbonnel, N.; Cosson, J.-F.

    2005-01-01

    Roč. 5, č. 1 (2005), s. 173-176. ISSN 1471-8278 Institutional research plan: CEZ:AV0Z6093917 Keywords : water vole * population genetics Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.219, year: 2005

  10. X-ray computed-tomography imaging of gas migration in water-saturated sediments: From capillary invasion to conduit opening

    Science.gov (United States)

    Choi, Jeong-Hoon; Seol, Yongkoo; Boswell, Ray; Juanes, Ruben

    2011-09-01

    The strong coupling between multiphase flow and sediment mechanics determines the spatial distribution and migration dynamics of gas percolating through liquid-filled soft granular media. Here, we investigate, by means of controlled experiments and computed tomography (CT) imaging, the preferential mode of gas migration in three-dimensional samples of water-saturated silica-sand and silica-silt sediments. Our experimental system allowed us to independently control radial and axial confining stresses and pore pressure while performing continuous x-ray CT scanning. The CT image analysis of the three-dimensional gas migration provides the first experimental confirmation that capillary invasion preferentially occurs in coarse-grained sediments whereas grain displacement and conduit openings are dominant in fine-grained sediments. Our findings allow us to rationalize prior field observations and pore-scale modeling results, and provide critical experimental evidence to explain the means by which conduits for the transit of methane gas may be established through the gas hydrate stability zone in oceanic sediments, and cause large episodic releases of carbon into the deep ocean.

  11. A highly efficient capillary electrophoresis-based method for size determination of water-soluble CdSe/ZnS core-shell quantum dots

    International Nuclear Information System (INIS)

    This paper describes a highly efficient method for size determination of water-soluble CdSe/ZnS core-shell quantum dots (QDs) by capillary electrophoresis (CE) using polymer additive as sieving medium. The influence of some factors, such as kinds and concentrations of the sieving medium, pH, concentrations of the background electrolyte (BGE) and applied voltage, on the separation of QDs was investigated. Under the optimal separation conditions, four different sized QDs were successfully separated, and the relative standard deviation (RSD) of the migration times for these QDs was below 1.013%. In addition, an equation was fit by taking into account the correlation existing between the electrophoretic mobilities and the sizes of a set of QDs. The feasibility of this equation to measure the sizes of other QDs was confirmed by comparison with the sizes obtained by transmission electron microscopy (TEM) experiment. This work offers a novel method for size determination of QDs, and provides an important reference on the study of QDs based on CE.

  12. Intramedullary capillary haemangioma.

    LENUS (Irish Health Repository)

    Kelleher, T

    2012-02-03

    Intramedullary capillary haemangioma is extremely rare and only four cases have been previously reported. We describe a further case, outlining the clinical, radiological, surgical and pathological features.

  13. Quantitative Analysis of Phthalates Plasticizers in Traditional Egyptian Foods (Koushary and Foul Medams), Black Tea, Instant Coffee and Bottled Waters by Solid Phase Extraction-Capillary Gas Chromatography-Mass Spectroscopy

    OpenAIRE

    Abdallah S. Ammar; Mahmoud A. Mohamed

    2008-01-01

    In the present study, method of solid-phase extraction followed by capillary gas chromatography coupled to mass spectrometry (SPE-GC-MS) was used for quantitative analysis of trace levels of phthalates in the most tow Egyptians traditional food (foul medams and koushary) and drinks (black tea and instant black coffee) and bottled water samples.Method performance was evaluated in terms of accuracy, linearity, limits of detection and recovery. Also the practical application of extraction ...

  14. New methodology for capillary electrophoresis with ESI-MS detection: Electrophoretic focusing on inverse electromigration dispersion gradient. High-sensitivity analysis of sulfonamides in waters.

    Science.gov (United States)

    Malá, Zdena; Gebauer, Petr; Boček, Petr

    2016-09-01

    This article describes for the first time the combination of electrophoretic focusing on inverse electromigration dispersion (EMD) gradient, a new separation principle described in 2010, with electrospray-ionization (ESI) mass spectrometric detection. The separation of analytes along the electromigrating EMD profile proceeds so that each analyte is focused and concentrated within the profile at a particular position given by its pKa and ionic mobility. The proposed methodology combines this principle with the transport of the focused zones to the capillary end by superimposed electromigration, electroosmotic flow and ESI suction, and their detection by the MS detector. The designed electrolyte system based on maleic acid and 2,6-lutidine is suitable to create an inverse EMD gradient of required properties and its components are volatile enough to be compatible with the ESI interface. The characteristic properties of the proposed electrolyte system and of the formed inverse gradient are discussed in detail using calculated diagrams and computer simulations. It is shown that the system is surprisingly robust and allows sensitive analyses of trace amounts of weak acids in the pKa range between approx. 6 and 9. As a first practical application of electrophoretic focusing on inverse EMD gradient, the analysis of several sulfonamides in waters is reported. It demonstrates the potential of the developed methodology for fast and high-sensitivity analyses of ionic trace analytes, with reached LODs around 3 × 10(-9) M (0.8 ng mL(-1)) of sulfonamides in spiked drinking water without any sample pretreatment. PMID:27543034

  15. Dispersive liquid-liquid microextraction combined with nonaqueous capillary electrophoresis for the determination of fluoroquinolone antibiotics in waters.

    Science.gov (United States)

    Herrera-Herrera, Antonio V; Hernández-Borges, Javier; Borges-Miquel, Teresa M; Rodríguez-Delgado, Miguel Á

    2010-10-01

    Dispersive liquid-liquid microextraction (DLLME) was combined for the first time with NACE-UV for the selective determination of eight fluoroquinolone antibiotics (lomefloxacin, levofloxacin, marbofloxacin, ciprofloxacin, sarafloxacin, enrofloxacin, danofloxacin and difloxacin) in mineral and run-off waters. Field-enhanced sample injection was carried out in order to improve the sensitivity, whereas pipemidic acid was used as internal standard. The BGE that provided complete separation of the eight analytes and the internal standard was composed of 3 M acetic acid, 49 mM ammonium acetate in 55:45 v/v methanol:ACN. Optimum DLLME conditions (extraction of 5 mL of water at pH 7.6 with 685 μL of CHCl(3) and 1250 μL of ACN, extractant and disperser solvents, respectively) were achieved by means of experimental design methodology. Calibration curves of the whole method were obtained with correlation coefficients (R) higher than 0.994 in all cases. An accuracy and precision study was carried out at different levels of concentration, finding that there were no significant differences (Student's t-test) between real and spiked concentrations. PMID:20859952

  16. Capillary Network Low-Temperature Wall Radiant Heating System Based on Solar Water%基于太阳能热水的毛细管网壁面低温辐射采暖系统

    Institute of Scientific and Technical Information of China (English)

    冯国会; 崔洁; 黄凯良; 李慧星; 郭慧宇

    2013-01-01

    The objective of this study is to analyze the possibility of applying capillary network as efficient heating end in solar hot water heating system. This paper established a set of capillary network used in solar hot water heating system,and tested heat dissipation performance,then its influence on indoor thermal performance is analyzed,and an economic analysis is done between capillary network and common floor heating end. The result shows that the heat transfer coefficient K of the capillary network wall heating is 1. 638 W/ m2. K,thermal efficiency 79.9% ;the average room temperature keeps around 17. 65 ℃ while outdoor average temperature is - 22 ℃ and the supply and return water temperature were 40/35 ℃; The capillary network has better comprehensive performance than ordinary floor heating and the cost saves up to 9%. The capillary network is evenly distributed by very closely spaced parallel capillary tubes, which enlarges the heat exchange area, then the heat transfer way between the capillary network and interior is radiation, so that it makes the indoor temperature distribute uniform and offer the best thermal comfort;the combination of the solar energy and capillary radiation heating system not only saves lots of energy but also improves the space utilization.%目的 分析毛细管网作为高效的散热末端,应用于太阳能热水采暖系统的可行性.方法 建立了以毛细管网为散热末端的太阳能热水采暖系统,测试铺设于壁面的毛细管网的散热性能以及其对室内热性能的影响,对比了毛细管网与普通地板采暖散热末端的经济性.结果 研究表明:毛细管网墙壁采暖的传热系数k=1.638 W/(m2·k),换热效率为79.9%;在供回水温度40 ~ 35℃,室外平均温度-22℃情况下,运行期间能使房间平均温度维持在17.65℃;对太阳能热水采暖系统而言,毛细管网比普通地板采暖散热末端具有更好的综合性能,成本节约达9%.结论 毛细管

  17. QUANTITATIVE DETERMINATION OF CHIRAL DICHLORPROP AND MECOPROP ENANTIOMERS IN DRINKING AND SURFACE WATERS BY SOLID-PHASE EXTRACTION AND CAPILLARY ELECTROPHORESIS

    Czech Academy of Sciences Publication Activity Database

    Tříska, Jan; Vrchotová, Naděžda

    2002-01-01

    Roč. 11, č. 7 (2002), s. 332-336. ISSN 1018-4619 Institutional research plan: CEZ:AV0Z6087904 Keywords : capillary electrophoresis * solid-phase extraction * chiral herbicides Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 0.309, year: 2002

  18. Capillary saturation and desaturation.

    Science.gov (United States)

    Hilfer, R; Armstrong, R T; Berg, S; Georgiadis, A; Ott, H

    2015-12-01

    Capillary desaturation experiments produce disconnected (trapped) ganglia of mesoscopic sizes intermediate between pore size and system size. Experimental evidence for interactions between these mesoscale clusters during desaturation is analyzed and discussed within the established microscopic and macroscopic laws of Newton, Young-Laplace, and Darcy. A theoretical expression for capillary number correlations is introduced that seems to have remained unnoticed. It expresses capillary desaturation curves in terms of stationary capillary pressures and relative permeabilities. The theoretical expression shows that the plateau saturation in capillary desaturation curves may in general differ from the residual nonwetting saturation defined through the saturation limit of the main hysteresis loop. Hysteresis effects as well as the difference between wetting and nonwetting fluids are introduced into the analysis of capillary desaturation experiments. The article examines experiments with different desaturation protocols and discusses the existence of a mesoscopic length scale intermediate between pore scale and sample scale. The theoretical expression is derived entirely within the existing traditional theory of two-phase flow in porous media and compared to a recent experiment. PMID:26764820

  19. Capillary saturation and desaturation

    Science.gov (United States)

    Hilfer, R.; Armstrong, R. T.; Berg, S.; Georgiadis, A.; Ott, H.

    2015-12-01

    Capillary desaturation experiments produce disconnected (trapped) ganglia of mesoscopic sizes intermediate between pore size and system size. Experimental evidence for interactions between these mesoscale clusters during desaturation is analyzed and discussed within the established microscopic and macroscopic laws of Newton, Young-Laplace, and Darcy. A theoretical expression for capillary number correlations is introduced that seems to have remained unnoticed. It expresses capillary desaturation curves in terms of stationary capillary pressures and relative permeabilities. The theoretical expression shows that the plateau saturation in capillary desaturation curves may in general differ from the residual nonwetting saturation defined through the saturation limit of the main hysteresis loop. Hysteresis effects as well as the difference between wetting and nonwetting fluids are introduced into the analysis of capillary desaturation experiments. The article examines experiments with different desaturation protocols and discusses the existence of a mesoscopic length scale intermediate between pore scale and sample scale. The theoretical expression is derived entirely within the existing traditional theory of two-phase flow in porous media and compared to a recent experiment.

  20. Loss of Propiconazole and its Four Stereoisomers from the Water Phase of Two Soil-Water Slurries as Measured by Capillary Electrophoresis

    Science.gov (United States)

    Propiconazole is a chiral fungicide used in agriculture for control of many fungal diseases on a variety of crops. This use provides opportunities for pollution of soil and, subsequently, groundwater. The rate of loss of propiconazole from the water phase of two different soil-wa...

  1. 基于中子成像的水泥基材料毛细吸水动力学研究%Water capillary suction dynamics of cement-based materials based on neutron radiography method

    Institute of Scientific and Technical Information of China (English)

    张鹏; 赵铁军; Wittmann F.H.; Lehmann E.

    2011-01-01

    总结了国内外有关水泥基材料毛细吸水的动力学机理及其现有模型,应用中子成像技术对其毛细吸水过程进行了可视化再现,对水分侵入的空间分布规律进行了定量分析.结果表明,在毛细孔吸附力作用下,水分前锋不断向水泥基材料内部推进,在吸水初期速度较快,后趋于平缓直至稳定;水分侵入曲线在深度和含量上同时增长,可以由线性+反S形模型来描述其空间分布特点,并与实测结果吻合良好;现有的"时间开方"及其修正模型对毛细吸水的后期预测不太合理,本文提出的渗透系数双曲线衰减模型更符合真实结果.%Dynamic mechanism and current models for water capillary suction of cement-based materials are summarized. Neutron Radiography method was applied to visualize the time dependent process of capillary suction and quantitatively to analyze the spatial moisture distribution in the material during water capillary suction. Results indicate that water front moved deeper into the cement-based materials with higher speed at the beginning of contact followed by lower penetration speed until nearly equilibrium. Both in the direction of depth and quantity the moisture distribution curve increased, which variation can be described by linear-plus-reverse-sigmoid model. For the relationship between water penetration depth and contact time, current square-root-of-time model and its modified models are not perfect to predict capillary suction at the late age. A hyperbolic regression model for coefficient of water penetration is developed which is well accord with the observed data.

  2. PREDICTION OF CAPILLARY RISE IN POROUS MEDIA BASED ON SOIL WATER CHARACTERISTIC CURVE%基于土水特征曲线预测多孔介质毛细上升过程

    Institute of Scientific and Technical Information of China (English)

    杜红普; 刘波; 王华军; 齐承英

    2013-01-01

    Capillary suction is one of the vital physical parameters to porous media and has been widely concerned in engineering practice.This paper combines the Gardner soil-water characteristic curve model and the structure parameters obtained by Micro-CT tomography at first.The unsaturated capillary rise model and a specific quantification for capillary rise in the porous media are then developed using the fitting relationship between suction and saturation and the finite difference method.Furthermore,laboratory experiments are carried out to confirm the availability of the model,where the narrow sub-washed sand is chosen as object.Parameters of the capillary rise process and the stable distribution of moisture are measured actually.Results indicate that a good agreement is presented between test and theoretical values.The proposed theory is feasible to predict the capillary rise and the moisture distribution of sand.%多孔介质中毛细吸力作为其重要物性参数,有着重要的工程应用背景.本文结合Gardner模型的土水特征曲线和Micro-CT(Micro computerized tomography)断层扫描仪获取的多孔介质的结构形态参数,根据吸力和饱和度的拟合关系,建立了一维非饱和毛细上升模型.同时,采用有限差分方法对多孔介质非饱和毛细水上升模型进行非稳态求解,获取不同时刻湿度场和毛细吸力的分布情况,并给出了一种量化多孔介质毛细上升过程的理论方法.为验证该方法的有效性,本文在室内以窄筛分洗砂作为研究对象,通过室内试验测定其毛细吸渗上升过程及稳定时的湿度分布.结果证实,模拟结果和实测结果整体上具有较高的吻合性.本文提出的多孔介质毛细上升的预测方法具有可行性,可用于预测砂土的毛细水上升高度和湿度场的分布状态.

  3. Spectrophotometric sensor system based on a liquid waveguide capillary cell for the determination of titanium: Application to natural waters, sunscreens and a lake sediment

    OpenAIRE

    Páscoa, Ricardo N. M. J.; Ildikó V. Tóth; Almeida, Agostinho A.; Rangel, António O. S. S.

    2011-01-01

    An analytical procedure for the spectrophotometric determination of titanium at trace levels was developed. The procedure involves the use of a multipumping flow system (MPFS) coupled with a liquid waveguide capillary cell (LWCC) with 1.0 m path length, 550 mm i.d. and 250 mL internal volume, which enabled to enhance the sensitivity of the determination and thus avoid complex and timeconsuming preconcentration steps. The determination is based on the colorimetric reaction of...

  4. Determination of stability constants of dibenzo-18-crown-6-ether complexes with alkali metal ions in methanol/water mixtures by capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Norková, Renáta; Kašička, Václav

    Pardubice: Univerzita Pardubice, 2014 - (Horna, A.; Jandera, P.). s. 82 ISBN 978-80-7395-777-3. [ISSS 2014. International Symposium on Separation Sciences /20./. 30.08.2014-02.09.2014, Praha] R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR(CZ) GA13-17224S Institutional support: RVO:61388963 Keywords : dibenzo-18-crown-6 * capillary electrophoresis * stability constant Subject RIV: CB - Analytical Chemistry, Separation

  5. Capillary electrophoretic profiling of tryptic digests of water soluble proteins from Bacillus thuringiensis-transgenic and non-transgenic maize species

    Czech Academy of Sciences Publication Activity Database

    Sázelová, Petra; Kašička, Václav; Leon, C.; Ibanez, E.; Cifuentes, A.

    2012-01-01

    Roč. 134, č. 3 (2012), s. 1607-1615. ISSN 0308-8146 R&D Projects: GA ČR(CZ) GA203/08/1428 Grant ostatní: AV ČR(CZ) 2008CZ0019 Institutional research plan: CEZ:AV0Z40550506 Keywords : Bt-transgenic maize * capillary zone electrophoresis * maize proteins Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.334, year: 2012

  6. Fast and simple method for determination of iodide in human urine, serum, sea water, and cooking salt by capillary zone electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Pantůčková, Pavla; Křivánková, Ludmila

    2004-01-01

    Roč. 25, 7-8 (2004), s. 1102-1110. ISSN 0173-0835 R&D Projects: GA ČR GA203/02/0023; GA ČR GA203/01/0401; GA AV ČR IAA4031103 Institutional research plan: CEZ:AV0Z4031919 Keywords : capillary zone electrophoresis * cooking salt * human serum Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.743, year: 2004

  7. Capillary Rise of Liquids in Nanopores

    CERN Document Server

    Huber, Patrick; Kityk, Andriy V

    2006-01-01

    We present measurements on the spontaneous imbibition (capillary rise) of water, a linear hydrocarbon (n-C16H34) and a liquid crystal (8OCB) into the pore space of monolithic, nanoporous Vycor glass (mean pore radius 5 nm). Measurements on the mass uptake of the porous hosts as a function of time, m(t), are in good agreement with the Lucas-Washburn square root of time prediction, typical of imbibition of liquids into porous hosts. The relative capillary rise velocities scale as expected from the bulk fluid parameters.

  8. Features concerning capillary pressure and the effect on two-phase and three-phase flow

    OpenAIRE

    2008-01-01

    The effect of capillary pressure related to immiscible WAG (Water Alternate Gas) is studied by use of a numerical simulator. The capillary pressure is found to have a significant effect on the pressure gradient and the total oil production both in two-phase and three-phase flow situations. When the capillary pressure is included in the simulation the total oil production is considerably lower than when the capillary pressure is neglected. Experimentally measured two-phase capil...

  9. Adamantyl-group containing mixed-mode acrylamide-based continuous beds for capillary electrochromatography. Part I: study of a synthesis procedure including solubilization of N-adamantyl-acrylamide via complex formation with a water-soluble cyclodextrin.

    Science.gov (United States)

    Al-Massaedh, Ayat Allah; Pyell, Ute

    2013-04-19

    A new synthesis procedure for highly crosslinked macroporous amphiphilic N-adamantyl-functionalized mixed-mode acrylamide-based monolithic stationary phases for capillary electrochromatography (CEC) is investigated employing solubilization of the hydrophobic monomer by complexation with a cyclodextrin. N-(1-adamantyl)acrylamide is synthesized and characterized as a hydrophobic monomer forming a water soluble-inclusion complex with statistically methylated-β-cyclodextrin. The stoichiometry, the complex formation constant and the spatial arrangement of the formed complex are determined. Mixed-mode monolithic stationary phases are synthesized by in situ free radical copolymerization of cyclodextrin-solubilized N-adamantyl acrylamide, a water soluble crosslinker (piperazinediacrylamide), a hydrophilic monomer (methacrylamide), and a negatively charged monomer (vinylsulfonic acid) in aqueous medium in bind silane-pretreated fused silica capillaries. The synthesized monolithic stationary phases are amphiphilic and can be employed in the reversed- and in the normal-phase mode (depending on the composition of the mobile phase), which is demonstrated with polar and non-polar analytes. Observations made with polar analytes and polar mobile phase can only be explained by a mixed-mode retention mechanism. The influence of the total monomer concentration (%T) on the chromatographic properties, the electroosmotic mobility, and on the specific permeability is investigated. With a homologues series of alkylphenones it is confirmed that the hydrophobicity (methylene selectivity) of the stationary phase increases with increasing mass fraction of N-(1-adamantyl)acrylamide in the synthesis mixture. PMID:23489493

  10. Subsidence and capillary effects in chalks

    OpenAIRE

    Delage, Pierre; Schroeder, Christian; Cui, Yu-Jun

    1996-01-01

    Based on the concepts of the mechanics of unsaturated soils where capillary phenomena arise between the wetting fluid (water) and the non-wetting one (air), the subsidence of chalks containing oil (non-wetting fluid) during water injection (wetting fluid) is analysed. It is shown that the collapse phenomenon of unsaturated soils under wetting provides a physical explanation and a satisfactory prediction of the order of magnitude of the subsidence of the chalk. The use of a well established co...

  11. Capillary electrophoresis - electrospray ionization mass spectrometry in small diameter capillaries

    Energy Technology Data Exchange (ETDEWEB)

    Wahl, J.H.; Goodlett, D.R.; Udseth, H.R.; Smith, R.D.

    1992-06-01

    Methods (such as small inner diameter capillaries) are being explored to increase analyte sensitivity in capillary electrophoresis- electrospray ionization/mass spectroscopy(CE-ESI/MS). Results are reported for melittin in a protein mixture, with 10 to 100 {mu}m ID capillaries; and for a mixture of aprotinin, cytochrome c, myoglobin, and carbonic anhydrase, with 5 to 50 {mu}m ID capillaries. It is shown that an increase in solute sensitivity occurs when small ID capillaries ({lt} 20 {mu}m) are used in CE-ESI/MS for both a peptide and a protein mixture. 3 figs. (DLC)

  12. Peptide profiling of tryptic digests of water soluble proteins from Bacillus thuringiensis-transgenic and non-transgenic maize species by capillary zone electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Sázelová, Petra; Kašička, Václav; Ibanez, E.; Cifuentes, A.

    Praha: Ústav organické chemie a biochemie AV ČR, v.v.i, 2011 - (Slaninová, J.; Borovičková, L.). s. 58-58 ISBN 978-80-86241-36-4. [Biologically Active Peptides /12./. 27.04.2011-29.04.2011, Praha] R&D Projects: GA ČR(CZ) GA203/08/1428; GA ČR(CZ) GA203/09/0675 Institutional research plan: CEZ:AV0Z40550506 Keywords : capillary zone electrophoresis * transgenic maize * tryptic peptides Subject RIV: CC - Organic Chemistry

  13. Determination of methicillin-resistant and methicillin-susceptible Staphylococcus aureus bacteria in blood by capillary zone electrophoresis

    OpenAIRE

    Horká, M. (Marie); Tesařová, M. (Marie); Karásek, P. (Pavel); Růžička, F.; Holá, V.; Sittová, M.; Roth, M

    2015-01-01

    We used capillary zone electrophoresis in supercritical water-etched and modified fused silica capillaries to separate methicillin-resistant and methicillin-susceptible Staphylococcus aureus bacteria from clinical samples of whole blood.

  14. Pore capillary pressure and saturation of methane hydrate bearing sediments

    Institute of Scientific and Technical Information of China (English)

    SUN Shicai; LIU Changling; YE Yuguang; LIU Yufeng

    2014-01-01

    To better understand the relationship between the pore capillary pressure and hydrate saturation in sedi-ments, a new method was proposed. First, the phase equilibria of methane hydrate in fine-grained silica sands were measured. As to the equilibrium data, the pore capillary pressure and saturation of methane hydrate were calculated. The results showed that the phase equilibria of methane hydrates in fine-grained silica sands changed due to the depressed activity of pore water caused by the surface group and negatively charged characteristic of silica particles as well as the capillary pressure in small pores together. The capil-lary pressure increased with the increase of methane hydrate saturation due to the decrease of the available pore space. However, the capillary-saturation relationship could not yet be described quantitatively because of the stochastic habit of hydrate growth.

  15. Capillary Discharge XUV Radiation Source

    Directory of Open Access Journals (Sweden)

    M. Nevrkla

    2009-01-01

    Full Text Available A device producing Z-pinching plasma as a source of XUV radiation is described. Here a ceramic capacitor bank pulse-charged up to 100 kV is discharged through a pre-ionized gas-filled ceramic tube 3.2 mm in diameter and 21 cm in length. The discharge current has amplitude of 20 kA and a rise-time of 65 ns. The apparatus will serve as experimental device for studying of capillary discharge plasma, for testing X-ray optics elements and for investigating the interaction of water-window radiation with biological samples. After optimization it will be able to produce 46.9 nm laser radiation with collision pumped Ne-like argon ions active medium. 

  16. Demonstration of a high repetition rate capillary discharge waveguide

    International Nuclear Information System (INIS)

    A hydrogen-filled capillary discharge waveguide operating at kHz repetition rates is presented for parameters relevant to laser plasma acceleration (LPA). The discharge current pulse was optimized for erosion mitigation with laser guiding experiments and MHD simulation. Heat flow simulations and measurements showed modest temperature rise at the capillary wall due to the average heat load at kHz repetition rates with water-cooled capillaries, which is promising for applications of LPAs such as high average power radiation sources

  17. Demonstration of a high repetition rate capillary discharge waveguide

    Energy Technology Data Exchange (ETDEWEB)

    Gonsalves, A. J., E-mail: ajgonsalves@lbl.gov; Pieronek, C.; Daniels, J.; Bulanov, S. S.; Waldron, W. L.; Mittelberger, D. E.; Leemans, W. P. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Liu, F.; Antipov, S.; Butler, J. E. [Euclid TechLabs, Gaithersburg, Maryland 20879 (United States); Bobrova, N. A.; Sasorov, P. V. [Keldysh Institute of Applied Mathematics, Moscow (Russian Federation)

    2016-01-21

    A hydrogen-filled capillary discharge waveguide operating at kHz repetition rates is presented for parameters relevant to laser plasma acceleration (LPA). The discharge current pulse was optimized for erosion mitigation with laser guiding experiments and MHD simulation. Heat flow simulations and measurements showed modest temperature rise at the capillary wall due to the average heat load at kHz repetition rates with water-cooled capillaries, which is promising for applications of LPAs such as high average power radiation sources.

  18. Numerical simulations of capillary barrier field tests

    Energy Technology Data Exchange (ETDEWEB)

    Morris, C.E. [Univ. of Wollongong (Australia); Stormont, J.C. [Univ. of New Mexico, Albuquerque, NM (United States)

    1997-12-31

    Numerical simulations of two capillary barrier systems tested in the field were conducted to determine if an unsaturated flow model could accurately represent the observed results. The field data was collected from two 7-m long, 1.2-m thick capillary barriers built on a 10% grade that were being tested to investigate their ability to laterally divert water downslope. One system had a homogeneous fine layer, while the fine soil of the second barrier was layered to increase its ability to laterally divert infiltrating moisture. The barriers were subjected first to constant infiltration while minimizing evaporative losses and then were exposed to ambient conditions. The continuous infiltration period of the field tests for the two barrier systems was modelled to determine the ability of an existing code to accurately represent capillary barrier behavior embodied in these two designs. Differences between the field test and the model data were found, but in general the simulations appeared to adequately reproduce the response of the test systems. Accounting for moisture retention hysteresis in the layered system will potentially lead to more accurate modelling results and is likely to be important when developing reasonable predictions of capillary barrier behavior.

  19. Numerical simulations of capillary barrier field tests

    International Nuclear Information System (INIS)

    Numerical simulations of two capillary barrier systems tested in the field were conducted to determine if an unsaturated flow model could accurately represent the observed results. The field data was collected from two 7-m long, 1.2-m thick capillary barriers built on a 10% grade that were being tested to investigate their ability to laterally divert water downslope. One system had a homogeneous fine layer, while the fine soil of the second barrier was layered to increase its ability to laterally divert infiltrating moisture. The barriers were subjected first to constant infiltration while minimizing evaporative losses and then were exposed to ambient conditions. The continuous infiltration period of the field tests for the two barrier systems was modelled to determine the ability of an existing code to accurately represent capillary barrier behavior embodied in these two designs. Differences between the field test and the model data were found, but in general the simulations appeared to adequately reproduce the response of the test systems. Accounting for moisture retention hysteresis in the layered system will potentially lead to more accurate modelling results and is likely to be important when developing reasonable predictions of capillary barrier behavior

  20. Transversally periodic solitary gravity-capillary waves.

    Science.gov (United States)

    Milewski, Paul A; Wang, Zhan

    2014-01-01

    When both gravity and surface tension effects are present, surface solitary water waves are known to exist in both two- and three-dimensional infinitely deep fluids. We describe here solutions bridging these two cases: travelling waves which are localized in the propagation direction and periodic in the transverse direction. These transversally periodic gravity-capillary solitary waves are found to be of either elevation or depression type, tend to plane waves below a critical transverse period and tend to solitary lumps as the transverse period tends to infinity. The waves are found numerically in a Hamiltonian system for water waves simplified by a cubic truncation of the Dirichlet-to-Neumann operator. This approximation has been proved to be very accurate for both two- and three-dimensional computations of fully localized gravity-capillary solitary waves. The stability properties of these waves are then investigated via the time evolution of perturbed wave profiles. PMID:24399922

  1. Determination of Chloroprene in Surface Water by Headspace Capillary GC%顶空-毛细管气相色谱法测定地表水中氯丁二烯

    Institute of Scientific and Technical Information of China (English)

    刘志航; 戴晓莹; 张丰

    2012-01-01

    A method of headspace capillary GC for determination of chloroprene in surface water was establish.Chloroprene was separated by HP-INNOWAX capillary column.With optimal shunt ratio,chloroprene showed a good linear range from 1~90 μg/L(r=0.9994).The method detection limint(S/D=10) was 0.01 μg/L,recovery was in the range of 98.5 %~104.3 %,and RSD was 2.45 %.The established method is convenient,fast,sensitive and accurate,and can be used for determination of chloroprene in surface water.%建立了顶空-毛细管柱-FID气相色谱检测地表水中氯丁二烯的方法。采用HP-INNOWAX色谱柱分离,优化了分流比及顶空条件,氯丁二烯在1~90μg/L的范围内获得了良好的线性关系(r=0.9994),检出限(S/D=10)为0.01μg/L,地表水实际样品的加标回收率为98.5%~104.3%,相对标准偏差为2.45%。该方法操作简便、快速、灵敏度高,准确度和精密度均能满足检测要求,适用于地表水中氯丁二烯的检测。

  2. Capillary Electrophoresis in the Presence of Fosfomycin

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Fosfomyein, a sodim salt of cis-(3-methyloxiranyl) phosphonic acid, was used as electrolyte in binary methanol-water media for capillary electrophoresis. The variety of electroosmotic flow with pH*,methanol concentration and ionic strength was investigated. The migration behavior of nine bases was examined under various conditions, and the separation of thymine, cytosine, 5-flurouracil, 4,6-diamino-pyrimidine, purine was accomplished.

  3. Hydrogen peroxide production in capillary underwater discharges

    Czech Academy of Sciences Publication Activity Database

    De Baerdemaeker, F.; Šimek, Milan; Leys, C.

    2007-01-01

    Roč. 40, č. 9 (2007), s. 2801-2809. ISSN 0022-3727 R&D Projects: GA AV ČR IAA1043403 Institutional research plan: CEZ:AV0Z20430508 Keywords : water breakdown * capillary * AC discharge * conductive liquid * hydrogen peroxide formation * initial rate * energy yield Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.200, year: 2007

  4. Hydrogen peroxide production in capillary underwater discharges

    Czech Academy of Sciences Publication Activity Database

    De Baerdemaeker, F.; Šimek, Milan; Člupek, Martin; Lukeš, Petr; Leys, C.

    2006-01-01

    Roč. 56, suppl. B (2006), s. 1132-1139. ISSN 0011-4626. [Symposium on Plasma Physics and Technology/22nd./. Praha, 26.6.2006-29.6.2006] R&D Projects: GA AV ČR(CZ) IAA1043403 Institutional research plan: CEZ:AV0Z20430508 Keywords : water * capillary * AC discharge * hydrogen peroxide formation * initial rate Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.568, year: 2006

  5. Capillary permeability in adipose tissue

    DEFF Research Database (Denmark)

    Paaske, W P; Nielsen, S L

    1976-01-01

    A method for measurement of capillary permeability using external registration of gamma emitting isotopes after close arterial bolus injection was applied to the isolated inguinal fat pad in slightly fasting rabbits. An average extraction of 26 per cent for 51Cr-EDTA was found at a plasma flow of...... about 7 ml/100 g-min. This corresponds to a capillary diffusion capacity of 2.0 ml/100 g-min which is half the value reported for vasodilated skeletal muscle having approximately twice as great capillary surface area. Thus, adipose tissue has about the same capillary permeability during slight metabolic...

  6. Ground and microgravity results of a circumferentially microgrooved capillary evaporator

    International Nuclear Information System (INIS)

    A circumferentially microgrooved capillary evaporator is here proposed as a reliable alternative for ground and spacecraft thermal control system applications. In this paper, experimental results concerning the start-up and thermal behavior of a capillary evaporator at steady state operation are presented. A capillary pumped loop was developed and tested at ground and microgravity conditions, using deionized water as the working fluid. The capillary evaporator has internally machined circumferential grooves with an average opening of 33 μm opening at 215 μm step into a 19.05 mm (3/4 in) diameter aluminum tube. The corresponding capillary pumping pressure is about 1.5 kPa. In both tests, power inputs up to 10 W (4.55 kW/m2) were successfully applied to the external surface of the evaporator, showing good performance under ground and microgravity conditions. The capillary evaporator as proposed proved to be a reliable alternative for industrial and space applications. - Highlights: • Circumferentially grooved capillary evaporators as alternative for thermal control. • Successful start-up operation at ground and microgravity conditions. • Successful steady state operation at ground and microgravity conditions. • Easy repriming in case of dry-out

  7. 固相微萃取-毛细管气相色谱法测定水中的吡啶%Determination of Pyridine in Water by Solid Phase Microextraction-Capillary GC

    Institute of Scientific and Technical Information of China (English)

    颜慧; 钱玉亭; 陆野

    2011-01-01

    用固相微萃取富集水中吡啶,毛细管气相色谱分离分析。通过试验确定了固相微萃取的分析参数。方法的检出限可达0.001mg/L,标准曲线相关系数0.9990,相对标准偏差(RSD)在0.9%~3.1%(n=5),平均加标回收率在92.4%~104%,已用于饮用水及地表水水中吡啶的测定。%Pyridine in water were enriched using Solid Phase Microextration(SPM E) and analyzed using Capillary GC-FID.Through tests the parameters of SPME were determined.The minimum detection limit,correlation coefficient of standard curve,the relative standard deviation and the average spike recovery were 0.001 mg/L,0.9990,0.9%~3.1%(n=5) and 92.4%~104% respectively.It has been applied to determine pyridine in drinking water and surface water.

  8. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; determination of semivolatile organic compounds in bottom sediment by solvent extraction, gel permeation chromatographic fractionation, and capillary-column gas chromatography/mass spectrometry

    Science.gov (United States)

    Furlong, E.T.; Vaught, D.G.; Merten, L.M.; Foreman, W.T.; Gates, Paul M.

    1996-01-01

    A method for the determination of 79 semivolatile organic compounds (SOCs) and 4 surrogate compounds in soils and bottom sediment is described. The SOCs are extracted from bottom sediment by solvent extraction, followed by partial isolation using high-performance gel permeation chromatography (GPC). The SOCs then are qualitatively identified and quantitative concentrations determined by capillary-column gas chromatography/mass spectrometry (GC/MS). This method also is designed for an optional simultaneous isolation of polychlorinated biphenyls (PCBs) and organochlorine (OC) insecticides, including toxaphene. When OCs and PCBs are determined, an additional alumina- over-silica column chromatography step follows GPC cleanup, and quantitation is by dual capillary- column gas chromatography with electron-capture detection (GC/ECD). Bottom-sediment samples are centrifuged to remove excess water and extracted overnight with dichloromethane. The extract is concentrated, centrifuged, and then filtered through a 0.2-micrometer polytetrafluoro-ethylene syringe filter. Two aliquots of the sample extract then are quantitatively injected onto two polystyrene- divinylbenzene GPC columns connected in series. The SOCs are eluted with dichloromethane, a fraction containing the SOCs is collected, and some coextracted interferences, including elemental sulfur, are separated and discarded. The SOC-containing GPC fraction then is analyzed by GC/MS. When desired, a second aliquot from GPC is further processed for OCs and PCBs by combined alumina-over-silica column chromatography. The two fractions produced in this cleanup then are analyzed by GC/ECD. This report fully describes and is limited to the determination of SOCs by GC/MS.

  9. Tapered capillary optics

    Science.gov (United States)

    Hirsch, Gregory

    1998-01-01

    A metal or glass wire is etched with great precision into a very narrowly tapering cone which has the shape of the desired final capillary-optics bore. By controlling the rate of removal of the wire from an etchant bath, a carefully controlled taper is produced. A sensor measures the diameter of the wire as it leaves the surface of the etchant. This signal is used for feedback control of the withdrawal speed. The etched wire undergoes a treatment to produce an extremely low surface-roughness. The etched and smoothed wire is coated with the material of choice for optimizing the reflectivity of the radiation being focused. This could be a vacuum evaporation, sputtering, CVD or aqueous chemical process. The coated wire is either electroplated, built up with electroless plating, or encapsulated in a polymer cylinder such as epoxy to increase the diameter of the wire for easier handling and greater robustness. During this process, the wire is vertically oriented and tensioned to assure that the wire is absolutely straight. The coated and electroformed wire is bonded to a flat, rigid substrate and is then periodically segmented by cutting or etching a series of narrow slits or grooves into the wire. The wire is vertically oriented and tensioned during the bonding process to assure that it is straight. The original wire material is then chemically etched away through the slits or otherwise withdrawn to leave the hollow internal bore of the final tapered-capillary optical element.

  10. Capillary action in a crack on the surface of asteroids with an application to 433 Eros

    Science.gov (United States)

    Jiang, Yu; Baoyin, Hexi

    2016-08-01

    Some asteroids contain water ice, and a space mission landing on an asteroid may take liquid to the surface of the asteroid. Gas pressure is very weak on the surface of asteroids. Here we consider the capillary action in a crack on the surface of irregular asteroids. The crack is modeled as a capillary which has a fixed radius. An asteroid's irregular gravitational potential influences the height of the liquid in the capillary. The height of the liquid in the capillary on the surface of such asteroids is derived from the asteroid's irregular gravitational potential. Capillary mechanisms are expected to produce an inhomogeneaous distribution of emergent liquid on the surface. This result is applied to asteroid 433 Eros, which has an irregular, elongated, and concave shape. Two cases are considered: (1) we calculate the height of the liquid in the capillary when the direction of the capillary is perpendicular to the local surface of the asteroid; (2) we calculate the height of the liquid in the capillary when the direction of the capillary is parallel to the vector from the center of mass to the surface position. The projected height in the capillary on the local surface of the asteroid seems to depend on the assumed direction of the capillary.

  11. Capillary solitons on a levitated medium.

    Science.gov (United States)

    Perrard, S; Deike, L; Duchêne, C; Pham, C-T

    2015-07-01

    A water cylinder deposited on a heated channel levitates on its own generated vapor film owing to the Leidenfrost effect. This experimental setup permits the study of the one-dimensional propagation of surface waves in a free-to-move liquid system. We report the observation of gravity-capillary waves under a dramatic reduction of gravity (up to a factor 30), leading to capillary waves at the centimeter scale. The generated nonlinear structures propagate without deformation and undergo mutual collisions and reflections at the boundaries of the domain. They are identified as Korteweg-de Vries solitons with negative amplitude and subsonic velocity. The typical width and amplitude-dependent velocities are in excellent agreement with theoretical predictions based on a generalized Korteweg-de Vries equation adapted to any substrate geometry. When multiple solitons are present, they interact and form a soliton turbulencelike spectrum. PMID:26274114

  12. Biomedical applications of capillary electrophoresis

    Science.gov (United States)

    Kartsova, L. A.; Bessonova, E. A.

    2015-08-01

    The review deals with modern analytical approaches used in capillary electrophoresis for solving medical and biological problems: search for biomarkers of various diseases and rapid diagnosis based on characteristic profiles of biologically active compounds by capillary electrophoresis with mass spectrometric detection; monitoring of the residual drugs in biological fluids for evaluating the efficiency of drug therapy; testing of the enantiomeric purity of pharmaceutical products; the use of novel materials as components of stationary and pseudo-stationary phases in capillary electrophoresis and capillary electrochromatography to increase the selectivity of separation of components of complex matrices; and identification of various on-line preconcentration techniques to reduce the detection limits of biologically active analytes. A topical trend in capillary electrophoresis required in clinical practice, viz., the design of microfluidic systems, is discussed. The bibliography includes 173 references.

  13. Capillary optics for radiation focusing

    International Nuclear Information System (INIS)

    Capillary lens technology may ultimately bring benefits to neutron and x-ray-based science like conventional lenses with visible light. Although the technology is not yet 10 years old, these lenses have already had a significant impact in engineering, science, and medicine. Capillary lenses are advantageous when it is desirable to increase the radiation flux at a location without regard to its angular divergence. PNNL has worked to improve the technology in several ways. A single, optimally tapered capillary was manufactured, which allows intensity gains of a factor of 270 for an initially parallel, incident x-ray beam. Feasibility of constructing neutron lenses using 58Ni (particularly effective at reflecting neutrons) has been explored. Three applications for capillary optics have been identified and studied: neutron telescope, Gandolphi x-ray diffractometry, and neutron radiotherapy. A brief guide is given for determining which potential applications are likely to be helped by capillary optics

  14. OPTIMIZATION OF PURGING EFFICIENCY AND QUANTIFICATION OF ORGANIC CONTAMINANTS FROM WATER USING A 1-L CLOSED-LOOP-STRIPPING APPARATUS AND COMPUTERIZED CAPILLARY COLUMN GC/MS

    Science.gov (United States)

    Optimization of a HERL-designed 1-L closed-loop-stripping (CLS) system, using variations of sample water bath temperatures and purging times, was accomplished by spiking five 1-chloroalkanes (C6, C8, C12, C16, and C18) into low organic Milli-Q reagent water to determine the recov...

  15. Oxidized multi-walled carbon nanotubes for the dispersive solid-phase extraction of quinolone antibiotics from water samples using capillary electrophoresis and large volume sample stacking with polarity switching.

    Science.gov (United States)

    Herrera-Herrera, Antonio V; Ravelo-Pérez, Lidia M; Hernández-Borges, Javier; Afonso, María M; Palenzuela, J Antonio; Rodríguez-Delgado, Miguel Ángel

    2011-08-01

    In this work, a new method for the determination of eleven quinolone antibiotics (moxifloxacin, lomefloxacin, danofloxacin, ciprofloxacin, levofloxacin, marbofloxacin, enrofloxacin, difloxacin, pefloxacin, oxolinic acid and flumequine) in different water samples using dispersive solid-phase extraction (dSPE) and capillary zone electrophoresis with diode-array detection was developed. Oxidized multi-walled carbon nanotubes (o-MWCNTs) were used for the first time as stationary phases for the off-line preconcentration by dSPE of the antibiotics. A 65 mM phosphate buffer at pH 8.5 was found adequate for analyte separation while large volume sample stacking with polarity switching of the analytes dissolved in water containing 10% (v/v) of acetonitrile was carried out in order to improve the sensitivity. dSPE parameters, such as sample volume and pH, o-MWCNT amount, volume and type of eluent in dSPE were optimized. Application of the developed method to the analysis of spiked Milli-Q, mineral, tap, and wastewater samples resulted in good recoveries values ranging from 62.3 to 116% with relative standard deviation values lower than 7.7% in all cases. Limits of detection were in the range of 28-94 ng/L. The proposed method is very fast, simple, repeatable, accurate and highly selective. PMID:21726875

  16. Advances in capillary electrophoresis

    International Nuclear Information System (INIS)

    In the 1980s, capillary electrophoresis (CE) developed rapidly into a first-class analytical separation technique. Its advances in instru-mentation and method development will not only enhance or complement existing mature separation techniques such as liquid chromatography and conventional slab gel electrophoresis, but will also severely challenge these separation methods. A brief overview of most striking achievement of CE in the 1980s is given, which illustrates the challenge to liquid chromatography and conventional slab gel electrophoresis, and some detailed discussions are presented to highlight the advantages of CE. New developments in CE that can be expected for the 1990s include especially column technology, separation chemistry and instrumentation, which will serve further to diversify and improve the applicability of this technique in areas which are poorly addressed by other separation methods. This paper considers and speculates on the technological advancements that can be expected to emerge for CE in the 1990s. (author). 95 refs.; 14 figs

  17. Analysis of Capillary Rise in Asymmetric Branch-Like Capillary

    Science.gov (United States)

    Li, Caoxiong; Shen, Yinghao; Ge, Hongkui; Yang, Zhihui; Su, Shuai; Ren, Kai; Huang, Heyu

    2016-05-01

    Transport in porous media is common in nature, attracting many attentions for a long time. Tree-like network model is often used as a simplification for porous space, expressing the complexity of pore spaces instead of capillary bundle. To investigate spontaneous imbibition characteristics in this network, a dynamic asymmetric branch-like capillary model is used to represent basic network structure, using fractal method to represent tortuosity. This work investigates the influence of parameters on imbibition process in the branch-like capillary model. An analytical equation for the imbibition mass versus time is derived. Parameters from capillary structures to liquid properties are taken into account and analyzed based on the numerical solution of the equation. It is found that the imbibition process in asymmetric branch-like capillary model can be recognized by four sections and brunching tubes are positive for imbibition process. Concomitantly, meniscus arrest event is simulated and discussed. Moreover, the influence of parameters on imbibition process is discussed. These parameters can be classified as static and dynamic. Static parameters mainly change the capillary force, which are related to the ultimate imbibition mass or imbibition ability, while dynamic parameters mainly have influence on resistance of flowing fluid, which are related to the imbibition speed in the imbibition process.

  18. Determination of Chloroprene in Source Water by Headspace Capillary Gas Chromatography%毛细管顶空气相色谱法测定水源水中的氯丁二烯

    Institute of Scientific and Technical Information of China (English)

    胡彬; 周倩如; 杨长晓

    2011-01-01

    Objective To establish capillary GC method for the determination of chloroprene in source water. Methods After the sample was equilibrated in a water bath of 60 ℃ for 20 min, the headspace gas was injected into the chromatograph, and the analyte was detected by a FID and quantified by external standard method. Results The limit of detection ( LOD) of the method was 0. 53μg/L, the spiked recoveries were 91. 2% - 102. 8% , and the relative standard deviation ( RSD) were 4. 2% -8. 5% . The linear range of method was 0. 002 - 0. 40 mg/L. Conclusion This method is applicable to determine chloroprene in source water.%目的 建立水源水中氯丁二烯的毛细管气相色谱检测方法.方法 样品在60℃水浴中平衡20 min后,采用抽气顶空进样法,GC-火焰离子化检测器(FID)检测,外标法定量.结果 方法检出限为0.53μg/L,加标回收率为91.2%-102.8%,相对标准偏差(RSD)为4.2%-8.5%.线性范围为0.002-0.40 mg/L.结论 该法可用于水源水中氯丁二烯的检测.

  19. Surface Tension and Capillary Rise

    Science.gov (United States)

    Walton, Alan J.

    1972-01-01

    Discussion of the shortcomings of textbook explanations of surface tension, distinguishing between concepts of tension and capillary rise. The arguments require only a clear understanding of Newtonian mechanics, notably potential energy. (DF)

  20. Capillary Condensation in Confined Media

    CERN Document Server

    Charlaix, Elisabeth

    2009-01-01

    We review here the physics of capillary condensation of liquids in confined media, with a special regard to the application in nanotechnologies. The thermodynamics of capillary condensation and thin film adsorption are first exposed along with all the relevant notions. The focus is then shifted to the modelling of capillary forces, to their measurements techniques (including SFA, AFM and crack tips) and to their influence on AFM imaging techniques as well as on the static and dynamic friction properties of solids (including granular heaps and sliding nanocontacts). A great attention is spent in investigating the delicate role of the surface roughness and all the difficulties involved in the reduction of the probe size to nanometric dimensions. Another major consequence of capillary condensation in nanosystems is the activation of several chemical and corrosive processes that can significantly alter the surface properties, such as dissolution/redeposition of solid materials and stress-corrosion crack propagati...

  1. Capillary electrophoresis electrospray ionization mass spectrometry interface

    Science.gov (United States)

    Smith, Richard D.; Severs, Joanne C.

    1999-01-01

    The present invention is an interface between a capillary electrophoresis separation capillary end and an electrospray ionization mass spectrometry emitter capillary end, for transporting an anolyte sample from a capillary electrophoresis separation capillary to a electrospray ionization mass spectrometry emitter capillary. The interface of the present invention has: (a) a charge transfer fitting enclosing both of the capillary electrophoresis capillary end and the electrospray ionization mass spectrometry emitter capillary end; (b) a reservoir containing an electrolyte surrounding the charge transfer fitting; and (c) an electrode immersed into the electrolyte, the electrode closing a capillary electrophoresis circuit and providing charge transfer across the charge transfer fitting while avoiding substantial bulk fluid transfer across the charge transfer fitting. Advantages of the present invention have been demonstrated as effective in providing high sensitivity and efficient analyses.

  2. XUV Radiation Emitted by Capillary Pinching Discharge

    Czech Academy of Sciences Publication Activity Database

    Vrbová, M.; Jančárek, A.; Vrba, Pavel; Nevrkla, M.; Kolař, P.

    Vol. 136. Dordrecht: Springer Proceedings in Physics , 2010 - (Lee, J.; Nam, C.; Janulewicz, K.), s. 257-262. (Springer Proceedings in Physics . 136). ISBN 978-94-007-1185-3. ISSN 0930-8989. [International Conference on X-Ray Laser s 2010/12th./. Gwangju (KR), 30.05.2010-04.06.2010] R&D Projects: GA MŠk LA08024 Institutional research plan: CEZ:AV0Z20430508 Keywords : Capillary Z-pinch * water window radiation source * RHMD Z engine Subject RIV: BH - Optics, Masers, Laser s http://www.springer.com/series/361

  3. Dosages d'hydrocarbures dans l'eau et le sédiment marins par infrarouge et chromatographie gazeuse sur colonne capillaire Hydrocarbon Titration in Water and Marine Sediments by Infrared Analysis and Gas Chromatography in a Capillary Column

    Directory of Open Access Journals (Sweden)

    Morel G.

    2006-11-01

    Full Text Available Nous avons étudié l'évolution des hydrocarbures pétroliers dans un site confiné, celui de l'Aber-Benoît (Finistère, à la suite de l'accident du super-pétrolier Amoco-Cadiz en mars 1978. Pour ce faire, plusieurs méthodes ont été mises en oeuvre, et tout particulièrement la chromato-graphie gazeuse sur colonne capillaire : le protocole analytique est décrit pour l'eau et pour le sédiment, après optimisation des techniques de filtration, de préconcentration et de fractionnement préalables à la mesure. Il est possible de travailler sur des échantillons de deux litres d'eau de mer ou de cinquante grammes de sédiment, avec des seuils de détection du niveau de la partie par trillion (ppt dans l'eau et de la centaine de ppt dans le sédiment. The evolution of petroleum hydrocarbons was analyzed in a confined site, at Aber-Benoît in the Finistère department, following the accident of the supertanker Amoco Cadiz in March 1978. To do this, several methods were developed, including, in particular, capillary coulumn as chromatography. The analytical procedure is described for water and sediment after optimization of filtering, preconcentrating and fractionating techniques prior to measuring. Analyses can be made with two liters of seawater or fifty grams of sediment, with detection thresholds in parts per trillion (ppt in water and the hundredth of a ppt in sediment.

  4. 填充柱和毛细管亚临界水色谱-FID检测的研究%Sub-critical Column and Capillary Chromatography with Water as Mobile Phase and Flame Ionization Detection

    Institute of Scientific and Technical Information of China (English)

    陆峰; 李玲; 孙鹏; 吴玉田

    2001-01-01

    A sub-critical chromatography (SubWC) with water as mobile phase and FID detection system isemployed to separate several alcohols with high or medium polarity, with pure water as the eluent. The flow rate getsup to 50 μl@min-1 for packed column (1 mm i.d.) and 70 μl@min-1 for capillary (50 μm i.d.). Increasing the temperatureup to 140 ℃, together with temperature programming, markedly improves the separation and peak shapes withinshort analysis time. Sub-critical state is guaranteed.%本文采用纯水作流动相,在一定压力下升高系统温度以保证水处在亚临界状态,FID为检测器,分析了甲醇、异丙醇、正丁醇、2-丁醇、正戊醇、异戊醇、己醇等具有中等以上极性的醇.填充柱(1 mm i.d.)流速50μl@min-1,毛细管柱(50 μm i.d.)流速70 μl.min-1.升高温度至140℃,结合温度梯度,亚临界水可以模拟高效液相色谱常用的甲醇-水混合流动相的极性,可以显著缩短分析时间并改善峰形.分析系统保证了亚临界状态,并有望应用于无紫外吸收、含量极低的极性化合物的分析.

  5. Groundwater recharge and capillary rise in a clayey catchment: modulation by topography and the Arctic Oscillation

    OpenAIRE

    T. M. Schrøder; D. Rosbjerg

    2004-01-01

    The signature left by capillary rise in the water balance is investigated for a 16 km2 clayey till catchment in Denmark. Integrated modelling for 1981–99 substantiates a 30% uphill increase in average net recharge, caused by the reduction in capillary rise when the water table declines. Calibration of the groundwater module is constrained by stream flow separation and water table wells. Net recharge and a priori parameterisation has been estimated from those same data, an automatic rain ga...

  6. Groundwater recharge and capillary rise in a clayey catchment: modulation by topography and the Arctic Oscillation

    OpenAIRE

    T. M. Schrøder; D. Rosbjerg

    2002-01-01

    International audience The signature left by capillary rise in the water balance is investigated for a 16 km2 clayey till catchment in Denmark. Integrated modelling for 1981?99 substantiates a 30% uphill increase in average net recharge, caused by the reduction in capillary rise when the water table declines. Calibration of the groundwater module is constrained by stream flow separation and water table wells. Net recharge and a priori parameterisation has been estimated from those same dat...

  7. The use of novel ionic liquid-in-water microemulsion without the addition of organic solvents in a capillary electrophoretic system.

    Science.gov (United States)

    Cao, Jun; Qu, Haibin; Cheng, Yiyu

    2010-10-01

    In this work, a new ionic liquid-in-water (IL/W) microemulsion without requiring toxic organic solvents was investigated as a pseudostationary phase (PSP) in CE. As observed during the IL/W microemulsion system, a fast and an efficient separation of eight phenolic acids was achieved using 1-butyl-3-methylimidazolivmhexa fluorophosphate (bmimPF(6)) as oil drops, Tween 20 as the surfactant, and borate as the BGE. The effects of oil phase, surfactant, buffer and pH on the separation were explored in detail to evaluate the novel PSP. In contrast, the detection efficiency of these same analytes was markedly decreased using oil-in-water (O/W) MEEKC. We have also validated the practicality of the IL/W microemulsion method by quantitative determination of acidic compounds in pharmaceutical injection. The results obtained indicated that an additional association between the IL cations and analytes tested seemed to play a prominent role in the separation mechanism exhibited by this novel PSP compared with the conventional O/W MEEKC. PMID:20922759

  8. Use of capillary strings in the dewatering of gas sensors at RAG; Einsatz von Capillary Strings zur Entwaesserung von Gassonden in der RAG

    Energy Technology Data Exchange (ETDEWEB)

    Seywald, M. [Rohoel-Aufsuchungs AG, Gampern (Austria)

    2008-10-23

    Due to successful applications of Artificial Lift measures and different applications of foamers, 'Rohoel Aufsuchungs AG' (RAG, Gampern, Austria) possesses an outstanding know-how within all ranges to gas well deliquification. In the contribution under consideration the authors report on the employment of capillary strings to the drainage of gas probes. In July, 2007, a capillary string was built in a gas sensor for the first time in the history of RAG. By means of the capillary string technology a foaming agent is pumped directly in front of the open perforation by means of an additional capillary string. The efficiency of the used foaming means clearly is improved by the employment of capillary strings and production is increased by 50 to 100 per cent. Due to continuous production of water, beside production acceleration also a production incremental can be obtained.

  9. Modelization and simulation of capillary barriers

    International Nuclear Information System (INIS)

    Among the different underground transport phenomena, that due to water flows is of great relevance. Water flows in infiltration and percolation processes are responsible of the transport of hazardous wastes towards phreatic layers. From the industrial and geological standpoints, there is a great interest in the design of natural devices to avoid the flows transporting polluting substances. This interest is increased when devices are used to isolate radioactive waste repositories, whose life is to be longer than several hundred years. The so-called natural devices are those based on the superimposition of material with different hydraulic properties. In particular, the flow retention in this kind stratified media, in unsaturated conditions, is basically due to the capillary barrier effect, resulting from placing a low conductivity material over another with a high hydraulic conductivity. Covers designed from the effect above have also to allow a drainage of the upper layer. The lower cost of these covers, with respect to other kinds of protection systems, and the stability in time of their components make them very attractive. However, a previous investigation to determine their effectivity is required. In this report we present the computer code BCSIM, useful for easy simulations of unsaturated flows in a capillary barrier configuration with drainage, and which is intended to serve as a tool for designing efficient covers. The model, the numerical algorithm and several implementation aspects are described. Results obtained in several simulations, confirming the effectivity of capillary barriers as a technique to build safety covers for hazardous waste repositories, are presented. (Author)

  10. Analysis of Water Buffalo Caseins in South China by Capillary Zone Electrophoresis%基于毛细管区带电泳系统的南方水牛奶酪蛋白分析技术研究

    Institute of Scientific and Technical Information of China (English)

    王丽娜; 李子超; 李昀锴; 徐明芳

    2011-01-01

    A capillary zone electrophoresis(CZE) method was developed for the separation and quantitative analysis of water buffalo caseins. The effects of several parameters, including buffer system and concentration, pH value, urea concentration and injection time on the separation efficiency of water buffalo caseins were investigated on an uncoated fused-silica capillary column ( 50. 2 cm × 75μm i. d. ) using separation voltage of 25 kV and detection wavelength of 214 nm at 25 ℃. Under the optimal conditions, the calibration curves were linear in the range of 0. 5 - 5.0 g/L for α-CN, β-CN and κ-CN with correlation coefficients no less than 0. 998 O. The spiked recoveries of three main caseins were in the range of 98% - 106%. The relative standard deviations(RSDs) for migration time,peak area and peak height were no more than 0. 67% , 3.0% and 3.2% , respectively. This method was simple, rapid and accurate, and could be used for the quality control and quantitative analysis of water buffalo milk and dairy products.%该文建立了一种毛细管区带电泳(CZE)分离南方水牛奶酪蛋白(CN)的方法,并对其进行定量分析.采用50.2 cm×75μm i.d.的未涂层熔融石英毛细管柱,在运行电压为25 kv,柱温为25℃,检测波长为214 nm的条件下,研究了缓冲液体系、缓冲液浓度、pH、尿素浓度及进样时间等对水牛奶酪蛋白分离的影响.实验测得α-CN、β-CN、κ-CN在0.5~5.0 g/L范围内线性关系良好,相关系数均不低于0.998 0,加标回收率为98%~106%,酪蛋白各组分的保留时间、峰面积及峰高的相对标准偏差(RSD)分别不高于0.67%、3.0%及3.2%.该法简便、快速、准确,可用于水牛奶及其乳制品的质量控制和定量检测.

  11. Rapid inorganic ion analysis using quantitative microchip capillary electrophoresis

    NARCIS (Netherlands)

    Vrouwe, Elwin X.; Lüttge, Regina; Olthuis, Wouter; Berg, van den Albert

    2006-01-01

    Rapid quantitative microchip capillary electrophoresis (CE) for online monitoring of drinking water enabling inorganic ion separation in less than 15s is presented. Comparing cationic and anionic standards at different concentrations the analysis of cationic species resulted in non-linear calibratio

  12. Dynamics of pre-ionized fast capillary discharge

    Czech Academy of Sciences Publication Activity Database

    Hübner, Jakub; Vrba, Pavel; Štraus, Jaroslav; Jancárek, A.; Nevrkla, M.

    T161, May (2014), 014047-014047. ISSN 0031-8949 R&D Projects: GA ČR GAP102/12/2043 Institutional support: RVO:61389021 Keywords : Pre-ionization * capillary discharge * x-ray laser * water window radiation Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.126, year: 2014

  13. Laser-based capillary polarimeter.

    Science.gov (United States)

    Swinney, K; Hankins, J; Bornhop, D J

    1999-01-01

    A laser-based capillary polarimeter has been configured to allow for the detection of optically active molecules in capillary tubes with a characteristic inner diameter of 250 microm and a 39-nL (10(-9)) sample volume. The simple optical configuration consists of a HeNe laser, polarizing optic, fused-silica capillary, and charge-coupled device (CCD) camera in communication with a laser beam analyzer. The capillary scale polarimeter is based on the interaction between a polarized laser beam and a capillary tube, which results in a 360 degree fan of scattered light. This array of scattered light contains a set of interference fringe, which respond in a reproducible manner to changes in solute optical activity. The polarimetric utility of the instrument will be demonstrated by the analysis of two optically active solutes, R-mandelic acid and D-glucose, in addition to the nonoptically active control, glycerol. The polarimetric response of the system is quantifiable with detection limits facilitating 1.7 x 10(-3) M or 68 x 10(-12) nmol (7 psi 10(-9) g) sensitivity. PMID:11315158

  14. Investigation of resonances in gravity-capillary wave turbulence

    Science.gov (United States)

    Aubourg, Quentin; Mordant, Nicolas

    2016-06-01

    We report experimental results on nonlinear wave coupling in surface wave turbulence on water at scales close to the crossover between surface gravity waves and capillary waves. We study three-wave correlations either in the frequency domain or in the wave-vector domain. We observe that in a weakly nonlinear regime, the dominant nonlinear interactions correspond to waves that are collinear or close to collinear. Although the resonant coupling of pure gravity waves is supposed to involve four waves, at the capillary crossover we observe a nonlocal coupling between a gravity wave and two capillary waves. Furthermore, nonlinear spectral spreading permits three-gravity wave coupling. These observations raise the question of the relevance of these processes in the oceanographic context and in particular the range of frequencies of gravity waves that may be impacted.

  15. Investigation of resonances in gravity-capillary wave turbulence

    CERN Document Server

    Aubourg, Quentin

    2016-01-01

    We report experimental results on nonlinear wave coupling in surface wave turbulence on water at scales close to the crossover between surface gravity waves and capillary waves. We study 3-wave correlations either in the frequency domain or in wavevector domain. We observe that in a weakly nonlinear regime, the dominant nonlinear interactions correspond to waves that are collinear or close to collinear. Although the resonant coupling of pure gravity waves is supposed to involve 4 waves, at the capillary crossover we observe a nonlocal coupling between a gravity wave and 2 capillary waves. Furthermore nonlinear spectral spreading permits 3-gravity wave coupling. These observations raise the question of the relevance of these processes in the oceanographic context and in particular the range of frequencies of gravity waves that may be impacted.

  16. The availability of capillary barrier for the control of soil contamination

    International Nuclear Information System (INIS)

    Underground buried hazardous substances may migrate to the surface soil to cause a pollution problem mainly due to capillary phenomena. A possibility to suppress upward vertical migration of water and mass by the use of coarse grain soil as capillary barrier was studied experimentally. Control effect of the insertion of coarse sand layer on upward water and mass migration was studied with one-dimentional column experiments, which showed retardation of the upward migration of water and chloride ion. The particle radius of soil cover and the control layer effective for control of mass migration was searched and the influence of rainfall was examined. The advantage and disadvantage capillary barrier as water barrier was discussed in comparison with other methods. The capillary barrier cannot be used independently, but, may be used as a component of multiple control to enhance the reliability of the disposal sites. (T.H.)

  17. Filling kinetics of liquids in nanochannels as narrow as 27 nm by capillary force

    OpenAIRE

    HAN, Anpan; Mondin, Giampietro; Hegelbach, Nicole G.; De Rooij, Nicolaas F; Staufer, Urs

    2010-01-01

    We report the filling kinetics of different liquids in nanofabricated capillaries with rectangular cross-section by capillary force. Three sets of channels with different geometry were employed for the experiments. The smallest dimension of the channel cross-section was respectively 27, 50, and 73 nm. Ethanol, isopropanol, water and binary mixtures of ethanol and water spontaneously filled nanochannels with inner walls exposing silanol groups. For all the liquids the position of the moving li...

  18. Capillary thinning of polymeric filaments

    DEFF Research Database (Denmark)

    Kolte, Mette Irene; Szabo, Peter

    1999-01-01

    The capillary thinning of filaments of a Newtonian polybutene fluid and a viscoelastic polyisobutylene solution are analyzed experimentally and by means of numerical simulation. The experimental procedure is as follows. Initially, a liquid sample is placed between two cylindrical plates. Then, th...

  19. Capillary thinning of polymeric filaments

    DEFF Research Database (Denmark)

    Kolte, Mette Irene; Szabo, Peter; Hassager, Ole

    The capillary thinning of a polymeric filament is analysed experimentally as well as by means of numerical simulation. The experimental procedure is as follows. Initially a liquid sample is kept between two cylindrical plates. Then the bottom plate is lowered under gravity to yield a given strain...

  20. Ion guiding in alumina capillaries

    DEFF Research Database (Denmark)

    Juhász, Z.; Sulik, B.; Biri, S.;

    2009-01-01

    Transmission of a few keV impact energy Ne ions through capillaries in anodic alumina membranes has been studied with different ion counting methods using an energy dispersive electrostatic spectrometer, a multichannel plate (MCP) array and sensitive current-measurement. In the present work, we...

  1. Capillary Rise in a Wedge

    Science.gov (United States)

    Piva, M.

    2009-01-01

    In introductory-level physics courses, the concept of surface tension is often illustrated using the example of capillary rise in thin tubes. In this paper the author describes experiments conducted using a planar geometry created with two small plates forming a thin wedge. The distribution of the fluid entering the wedge can be studied as a…

  2. PKQuest: capillary permeability limitation and plasma protein binding – application to human inulin, dicloxacillin and ceftriaxone pharmacokinetics

    OpenAIRE

    Levitt, David G.

    2002-01-01

    Background It is generally assumed that the tissue exchange of antibiotics is flow limited (complete equilibration between the capillary and the tissue water). This assumption may not be valid if there is a large amount of plasma protein binding because the effective capillary permeability depends on the product of the intrinsic capillary permeability (PS) and the fraction of solute that is free in the blood (fwB). PKQuest, a new generic physiologically based pharmacokinetic software routine ...

  3. Measurements of capillary pressure and electric permittivity of gas-water systems in porous media at elevated pressures: application to geological storage of CO2 in aquifers and wetting behavior in coal

    NARCIS (Netherlands)

    Plug, W.-J.

    2007-01-01

    Sequestration of CO2 in aquifers and coal layers is a promising technique to reduce greenhouse gas emissions. Considering the reservoir properties, e.g. wettability, heterogeneity and the caprocks sealing capacity, the capillary pressure is an important measure to evaluate the efficiency, the succes

  4. Capillary Action in a Crack on the Surface of Asteroids with an Application to 433 Eros

    CERN Document Server

    Jiang, Yu

    2016-01-01

    Some asteroids contain water ice, and a space mission landing on an asteroid may take liquid to the surface of the asteroid. Gas pressure is very weak on the surface of asteroids. Here we consider the capillary action in a crack on the surface of irregular asteroids. The crack is modelled as a capillary which has a fixed radius. An asteroid s irregular gravitational potential influences the height of the liquid in the capillary. The height of the liquid in the capillary on the surface of such asteroids is derived from the asteroid s irregular gravitational potential. Capillary mechanisms are expected to produce an inhomogeneaous distribution of emergent liquid on the surface. This result is applied to asteroid 433 Eros, which has an irregular, elongated, and concave shape. Two cases are considered 1) we calculate the height of the liquid in the capillary when the direction of the capillary is perpendicular to the local surface of the asteroid; 2) we calculate the height of the liquid in the capillary when the...

  5. Determination of Pyridine in Water by Headspace - Capillary GC - FID%顶空-毛细管柱气相色谱法测定水中吡啶

    Institute of Scientific and Technical Information of China (English)

    钱玉亭; 颜慧; 陆野

    2011-01-01

    建立了顶空进样-气相色谱法测定水中吡啶的分析方法。选择氢火焰离子化检测器(FID)测定,用保留时间定性,外标法定量。吡啶质量浓度在0.2mg/L-5.0mg/L范围内有良好的线形关系,相关系数为0.9995.检出限为0.03mg/L。三组吡啶溶液的相对标准偏差分别为4.27%、2.13%、1.68%,加标回收率在78.0~95.3之间。该方法分离度高,精密度、检测灵敏度高,线性相关性强,符合GB3838—2002((地表水环境质量标准》的要求。同时还具有预处理简便,分析速度快,干扰少等优点。%In this paper, the method of determining pyridine in water by headspace - capillary GC - FID is developed. This method took retention time as the quality method and external standard as the quantity method which turned out to be correct. The correlation coefficient is 0. 999 5 in the range of pyridine's concentration from 0. 2 to 5.0 mg/L. The method detection limit is 0. 03 mg/L, the RSD was 1.39%-4. 26% , and the recovery rate of spiked sample ranges from 78.0% -95.3%. This method has high chromatographic resolution, favorable accuracy, linear responses and high sensitivity, and meets the requirement of GB 3838 - 2002. Some advantages of this method include convenient pretreatment, quick analysis and little interference etc.

  6. Prediction of Three-Phase Capillary Pressure using a Network Model Anchored to Two-Phase Data

    OpenAIRE

    Dale, Elisabeth Iren; Dijke, Marinus I. J. van; Skauge, Arne

    2008-01-01

    Three-phase capillary pressure is difficult to measure experimentally and therefore has to be estimated by other methods. In this work a network model was applied to generate a consistent set of two-phase and three-phase capillary pressure curves. Experimental data for two-phase, gas-oil and oil-water, capillary pressure from a North Sea reservoir was used in this study. The network model was anchored to the measured two-phase data, and three-phase capillary pressure was constr...

  7. Capillary hemangioma of palatal mucosa

    OpenAIRE

    Bharti, Vipin; Singh, Jagmohan

    2012-01-01

    Hemangiomas are common tumors characterized microscopically by proliferation of blood vessels. The congenital hemangioma is often present at birth and may become more apparent throughout life. They are probably developmental rather than neoplastic in origin. Despite their benign origin and behavior, hemangiomas in the oral cavity are always of clinical importance to the dental profession and require appropriate clinical management. This case report presents a case of capillary hemangioma of a...

  8. Exponential asymptotics and capillary waves

    OpenAIRE

    Chapman, S. J.; Vanden-Broeck, J.

    2002-01-01

    Recently developed techniques in exponential asymptotics beyond all orders are employed on the problem of potential flows with a free surface and small surface tension, in the absence of gravity. Exponentially small capillary waves are found to be generated on the free surface where the equipotentials from singularities in the flow (for example, stagnation points and corners) meet it. The amplitude of these waves is determined, and the implications are considered for many quite general flows....

  9. Nonlinear waves in capillary electrophoresis

    OpenAIRE

    Ghosal, Sandip; Chen, Zhen

    2012-01-01

    Electrophoretic separation of a mixture of chemical species is a fundamental technique of great usefulness in biology, health care and forensics. In capillary electrophoresis the sample migrates in a microcapillary in the presence of a background electrolyte. When the ionic concentration of the sample is sufficiently high, the signal is known to exhibit features reminiscent of nonlinear waves including sharp concentration ‘shocks’. In this paper we consider a simplified model consisting of a ...

  10. Inertial Rise in Short Capillaries

    CERN Document Server

    Shardt, Orest; Derksen, J J; Mitra, Sushanta K

    2013-01-01

    In this fluid dynamics video we show capillary rise experiments with diethyl ether in short tubes. The height of each short tube is less than the maximum height the liquid can achieve, and therefore the liquid reaches the top of the tube while still rising. Over a narrow range of heights, the ether bulges out from the top of the tube and spreads onto the external wall.

  11. Treelike networks accelerating capillary flow

    Science.gov (United States)

    Shou, Dahua; Ye, Lin; Fan, Jintu

    2014-05-01

    Transport in treelike networks has received wide attention in natural systems, oil recovery, microelectronic cooling systems, and textiles. Existing studies are focused on transport behaviors under a constant potential difference (including pressure, temperature, and voltage) in a steady state [B. Yu and B. Li, Phys. Rev. E 73, 066302 (2006), 10.1103/PhysRevE.73.066302; J. Chen, B. Yu, P. Xu, and Y. Li, Phys. Rev. E 75, 056301 (2007), 10.1103/PhysRevE.75.056301]. However, dynamic (time-dependent) transport in such systems has rarely been concerned. In this work, we theoretically investigate the dynamics of capillary flow in treelike networks and design the distribution of radius and length of local branches for the fastest capillary flow. It is demonstrated that capillary flow in the optimized tree networks is faster than in traditional parallel tube nets under fixed constraints. As well, the flow time of the liquid is found to increase approximately linearly with penetration distance, which differs from Washburn's classic description that flow time increases as the square of penetration distance in a uniform tube.

  12. Separation of selenium compounds by CE-ICP-MS in dynamically coated capillaries applied to selenized yeast samples

    DEFF Research Database (Denmark)

    Bendahl, Lars; Gammelgaard, Bente

    2004-01-01

    The selenium species in nutritional supplement tablets, based on selenized yeast, were separated by capillary zone electrophoresis using capillaries coated dynamically with poly(vinyl sulfonate) and detected by ICP-MS. Sample pre-treatment consisted of cold-water extraction by sonication and...

  13. Progression of Diabetic Capillary Occlusion: A Model.

    Directory of Open Access Journals (Sweden)

    Xiao Fu

    2016-06-01

    Full Text Available An explanatory computational model is developed of the contiguous areas of retinal capillary loss which play a large role in diabetic maculapathy and diabetic retinal neovascularization. Strictly random leukocyte mediated capillary occlusion cannot explain the occurrence of large contiguous areas of retinal ischemia. Therefore occlusion of an individual capillary must increase the probability of occlusion of surrounding capillaries. A retinal perifoveal vascular sector as well as a peripheral retinal capillary network and a deleted hexagonal capillary network are modelled using Compucell3D. The perifoveal modelling produces a pattern of spreading capillary loss with associated macular edema. In the peripheral network, spreading ischemia results from the progressive loss of the ladder capillaries which connect peripheral arterioles and venules. System blood flow was elevated in the macular model before a later reduction in flow in cases with progression of capillary occlusions. Simulations differing only in initial vascular network structures but with identical dynamics for oxygen, growth factors and vascular occlusions, replicate key clinical observations of ischemia and macular edema in the posterior pole and ischemia in the retinal periphery. The simulation results also seem consistent with quantitative data on macular blood flow and qualitative data on venous oxygenation. One computational model applied to distinct capillary networks in different retinal regions yielded results comparable to clinical observations in those regions.

  14. Effect of surfactant on kinetics of thinning of capillary bridges

    Science.gov (United States)

    Nowak, Emilia; Kovalchuk, Nina; Simmons, Mark

    2015-11-01

    Kinetics of thinning of capillary bridges is of great scientific and industrial interest being of vital importance for example in various emulsification and microfluidic processes. It is well known that the rate of bridge thinning is proportional to the interfacial tension. Therefore it is expected that the process should slow down by addition of surfactant. The kinetics of capillary bridges in the presence of surfactant was studied by the dripping of liquid from a capillary tip under conditions of nearly zero flow rate (We personal care products. The viscosity, surfactant activity and adsorption kinetics have been controlled by addition of glycerol and sodium chloride. The study has shown that the kinetics of capillary bridges are determined by dynamic surface tension rather than by its equilibrium value. In particular, the kinetics of the bridge thinning for the 0.1 g L-1 aqueous SLES solution is practically the same as that of pure water despite twice lower equilibrium surface tension. EPSRC Programme Grant, MEMPHIS, EP/K0039761/1.

  15. Effect of surfactant on kinetics of thinning of capillary bridges

    Science.gov (United States)

    Nowak, Emilia; Kovalchuk, Nina; Simmons, Mark

    2015-11-01

    Kinetics of thinning of capillary bridges is of great scientific and industrial interest being of vital importance for example in various emulsification and microfluidic processes. It is well known that the rate of bridge thinning is proportional to the interfacial tension. Therefore it is expected that the process should slow down by addition of surfactant. The kinetics of capillary bridges in the presence of surfactant was studied by the dripping of liquid from a capillary tip under conditions of nearly zero flow rate (We ether sulphate (SLES), which is broadly used in personal care products. The viscosity, surfactant activity and adsorption kinetics have been controlled by addition of glycerol and sodium chloride. The study has shown that the kinetics of capillary bridges are determined by dynamic surface tension rather than by its equilibrium value. In particular, the kinetics of the bridge thinning for the 0.1 g L-1 aqueous SLES solution is practically the same as that of pure water despite twice lower equilibrium surface tension. EPSRC Programme Grant, MEMPHIS, EP/K0039761/1.

  16. A capillary network model for gas migration in engineered barriers

    International Nuclear Information System (INIS)

    Gas may be generated in a waste repository by a number of mechanisms, including anaerobic corrosion of metals and microbial degradation. Scoping calculations indicate that a free gas phase will probably form. Here attention is focused on two hazards this may pose. First, a gas pressure buildup may damage engineered barriers. Second, migrating gas may displace contaminated pore water. In previous studies, Darcy two-phase flow models have been used to calculate gas pressures and pore water displacement. A two-dimensional capillary network model has been developed and implemented in a numerical code, GARNET. Example calculations of the migration of gas from a point source have been undertaken to demonstrate its functionality and to indicate how phenomena, such as intermittent gas fluxes, may be modelled. Results indicate that the capillary network model reproduces behaviour observed in gas migration through low permeability media, and is a viable alternative to Darcy two-phase flow models

  17. Anomalous capillary filling and wettability reversal in nanochannels

    CERN Document Server

    Gravelle, Simon; Bocquet, Lydéric; Joly, Laurent

    2016-01-01

    This work revisits capillary filling dynamics in the regime of nanometric to subnanometric channels. Using molecular dynamics simulations of water in carbon nanotubes, we show that for tube radii below one nanometer, both the filling velocity and the Jurin rise vary non-monotonically with the tube radius. Strikingly, with fixed chemical surface properties, this leads to confinement-induced reversal of the tube wettability from hydrophilic to hydrophobic for specific values of the radius. By comparing with a model liquid metal, we show that these effects are not specific to water. Using complementary data from slit channels, we then show that they can be described using the disjoin-ing pressure associated with the liquid structuring in confinement. This breakdown of the standard continuum framework is of main importance in the context of capillary effects in nanoporous media, with potential interests ranging from membrane selectivity to mechanical energy storage.

  18. Capillary pumped loop body heat exchanger

    Science.gov (United States)

    Swanson, Theodore D. (Inventor); Wren, deceased, Paul (Inventor)

    1998-01-01

    A capillary pumped loop for transferring heat from one body part to another body part, the capillary pumped loop comprising a capillary evaporator for vaporizing a liquid refrigerant by absorbing heat from a warm body part, a condenser for turning a vaporized refrigerant into a liquid by transferring heat from the vaporized liquid to a cool body part, a first tube section connecting an output port of the capillary evaporator to an input of the condenser, and a second tube section connecting an output of the condenser to an input port of the capillary evaporator. A wick may be provided within the condenser. A pump may be provided between the second tube section and the input port of the capillary evaporator. Additionally, an esternal heat source or heat sink may be utilized.

  19. Microfluidic PMMA interfaces for rectangular glass capillaries

    International Nuclear Information System (INIS)

    We present the design and fabrication of a polymeric capillary fluidic interface fabricated by micro-milling. The design enables the use of glass capillaries with any kind of cross-section in complex microfluidic setups. We demonstrate two different designs of the interface; a double-inlet interface for hydrodynamic focusing and a capillary interface with integrated pneumatic valves. Both capillary interfaces are presented together with examples of practical applications. This communication shows the design optimization and presents details of the fabrication process. The capillary interface opens up for the use of complex microfluidic systems in single-use glass capillaries. They also enable simple fabrication of glass/polymer hybrid devices that can be beneficial in many research fields where a pure polymer chip negatively affects the device's performance, e.g. acoustofluidics. (technical note)

  20. Investigation of resonances in gravity-capillary wave turbulence

    OpenAIRE

    Aubourg, Quentin; Mordant, Nicolas

    2016-01-01

    We report experimental results on nonlinear wave coupling in surface wave turbulence on water at scales close to the crossover between surface gravity waves and capillary waves. We study 3-wave correlations either in the frequency domain or in wavevector domain. We observe that in a weakly nonlinear regime, the dominant nonlinear interactions correspond to waves that are collinear or close to collinear. Although the resonant coupling of pure gravity waves is supposed to involve 4 waves, at th...

  1. Pump effect of a capillary discharge in electrically conductive liquids

    Czech Academy of Sciences Publication Activity Database

    De Baerdemaeker, F.; Šimek, Milan; Leys, C.; Verstraete, W.

    2007-01-01

    Roč. 27, č. 4 (2007), s. 473-485. ISSN 0272-4324 R&D Projects: GA AV ČR IAA1043403 Institutional research plan: CEZ:AV0Z20430508 Keywords : water * conductive * capillary * AC discharge * pump Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.747, year: 2007 http://www.springerlink.com/content/w802073563282272/fulltext.pdf

  2. Experimental Study on the Influence of Curing Conditions on Capillary Absorption of Concrete

    OpenAIRE

    Li-cheng WANG; Bao, Jiu-Wen; Cheng, Bao-Juan

    2016-01-01

    Both the hardening process and formation of microstructure of concrete are significantly influenced by the curing condition. The capillary absorption of concrete is closely related to the structure and distribution of the pores within the material. This paper presents an experimental study on the influence of four curing conditions, i.e., standard curing, natural curing, water curing, and sealed curing, on the capillary absorption of normal concrete. Compressive strength tests on the cylinder...

  3. Evaporation-induced evolution of the capillary force between two grains

    OpenAIRE

    Mielniczuk, Boleslaw; Hueckel, Tomasz; El Youssoufi, Moulay Saïd

    2014-01-01

    International audience The evolution of capillary forces during evap-oration and the corresponding changes in the geometrical characteristics of liquid (water) bridges between two glass spheres with constant separation are examined experimen-tally. For comparison, the liquid bridges were also tested for mechanical extension (at constant volume). The obtained results reveal substantial differences between the evolution of capillary force due to evaporation and the evolution due to extension...

  4. DNA Sequencing Using capillary Electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Barry Karger

    2011-05-09

    The overall goal of this program was to develop capillary electrophoresis as the tool to be used to sequence for the first time the Human Genome. Our program was part of the Human Genome Project. In this work, we were highly successful and the replaceable polymer we developed, linear polyacrylamide, was used by the DOE sequencing lab in California to sequence a significant portion of the human genome using the MegaBase multiple capillary array electrophoresis instrument. In this final report, we summarize our efforts and success. We began our work by separating by capillary electrophoresis double strand oligonucleotides using cross-linked polyacrylamide gels in fused silica capillaries. This work showed the potential of the methodology. However, preparation of such cross-linked gel capillaries was difficult with poor reproducibility, and even more important, the columns were not very stable. We improved stability by using non-cross linked linear polyacrylamide. Here, the entangled linear chains could move when osmotic pressure (e.g. sample injection) was imposed on the polymer matrix. This relaxation of the polymer dissipated the stress in the column. Our next advance was to use significantly lower concentrations of the linear polyacrylamide that the polymer could be automatically blown out after each run and replaced with fresh linear polymer solution. In this way, a new column was available for each analytical run. Finally, while testing many linear polymers, we selected linear polyacrylamide as the best matrix as it was the most hydrophilic polymer available. Under our DOE program, we demonstrated initially the success of the linear polyacrylamide to separate double strand DNA. We note that the method is used even today to assay purity of double stranded DNA fragments. Our focus, of course, was on the separation of single stranded DNA for sequencing purposes. In one paper, we demonstrated the success of our approach in sequencing up to 500 bases. Other

  5. A New Conductivity Detector for Capillary Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new conductivity detector for capillary electrophoresis consisting of an electrochemical cell and a conductive meter was developed. In the cell, the microelectrode and capillary were inserted through the cell wall and fixed by screws and sealing ring, the ends of microelectrode and capillary were located by a guide with two cross holes. LOD for K+ was 1.5×10-5 mol/L.

  6. Serum proteins analysis by capillary electrophoresis

    OpenAIRE

    Uji, Yoshinori; Okabe, Hiroaki

    2001-01-01

    The purpose of this study was to evaluate the efficacy of multi-capillary electrophoresis instrument in clinical laboratory. An automated clinical capillary electrophoresis system was evaluated for performing serum proteins electrophoresis and immuno-fixation electrophoresis by subtraction. In this study the performance of capillary electrophoresis was compared with the cellulose acetate membrane electrophoresis and agarose gel immunofixation electrophoresis for serum proteins. The results of...

  7. Cytokine Analysis by Immunoaffinity Capillary Electrophoresis

    OpenAIRE

    Mendonca, Mark; Kalish, Heather

    2013-01-01

    Immunoaffinity capillary electrophoresis (ICE) is a powerful tool used to detect and quantify target proteins of interest in complex biological fluids. The target analyte is captured and bound to antibodies immobilized onto the wall of a capillary, labeled in situ with a fluorescent dye, eluted and detected online using laser-induced fluorescence following electrophoretic separation. Here, we illustrate how to construct an immunoaffinity capillary and utilize it to run ICE in order to capture...

  8. Electromigration dispersion in Capillary Electrophoresis

    CERN Document Server

    Chen, Zhen; 10.1007/s11538-011-9708-7

    2012-01-01

    In a previous paper (S. Ghosal and Z. Chen Bull. Math. Biol. 2010, vol. 72, pg. 2047) it was shown that the evolution of the solute concentration in capillary electrophoresis is described by a nonlinear wave equation that reduced to Burger's equation if the nonlinearity was weak. It was assumed that only strong electrolytes (fully dissociated) were present. In the present paper it is shown that the same governing equation also describes the situation where the electrolytic buffer consists of a single weak acid (or base). A simple approximate formula is derived for the dimensionless peak variance which is shown to agree well with published experimental data.

  9. Microbeam-coupled capillary electrophoresis

    International Nuclear Information System (INIS)

    Within the first few microseconds following a charged particle traversal of a cell, numerous oxygen and nitrogen radicals are formed along the track. Presented here is a method, using capillary electrophoresis, for simultaneous measurement, within an individual cell, of specific reactive oxygen species, such as the superoxide radical (O2-*) as well as the native and oxidised forms of glutathione, an ubiquitous anti-oxidant that assists the cell in coping with these species. Preliminary data are presented as well as plans for integrating this system into the charged particle microbeam at Columbia University. (authors)

  10. Capillary electrophoresis theory and practice

    CERN Document Server

    Grossman, Paul D

    1992-01-01

    This book is designed to be a practical guide, used by wide audience, including those new to CE, those more experienced, routine users, those interested in technology development, and those involved with applications research. References have been emphasized to allow the reader to explore the detailed specifics and theoretical foundations.This book draws together the rapidly evolving, diverse, and multidisciplinary subject of capillary electrophoresis (CE). It is designed as a practical guide to be used by a wide audience, including those new to CE as well as more experienced users. T

  11. Exotic containers for capillary surfaces

    Science.gov (United States)

    Concus, Paul; Finn, Robert

    1991-01-01

    This paper discusses 'exotic' rotationally symmetric containers that admit an entire continuum of distinct equilibrium capillary free surfaces. The paper extends earlier work to a larger class of parameters and clarifies and simplifies the governing differential equations, while expressing them in a parametric form appropriate for numerical integration. A unified presentation suitable for both zero and nonzero gravity is given. Solutions for the container shapes are depicted graphically along with members of the free-surface continuum, and comments are given concerning possible physical experiments.

  12. Rise of the main meniscus in rectangular capillaries: Experiments and modeling.

    Science.gov (United States)

    Wu, Pingkeng; Zhang, Hua; Nikolov, Alex; Wasan, Darsh

    2016-01-01

    The rise of the main meniscus in rectangular capillaries is important in interpreting the phenomenon of fluid flow in porous media. Despite many experimental studies reported in the literature, there is no universal model for the rise of the main meniscus in either rectangular or square capillaries. In this work, we present an extensive experimental study and modeling of the rise of the main meniscus in both square and rectangular capillaries. Experimental work was carried out using three different liquids (water, ethanol, and hexadecane) in borosilicate glass and plastic (polystyrene) capillaries to investigate the effect of the contact angle and capillary size on the equilibrium main meniscus height. A universal model (an extended two-wall model) based on the Laplace equation was developed to predict the equilibrium height of the main meniscus in rectangular capillaries. Results have shown that, in a wide range of capillary sizes and contact angles, the predicted equilibrium heights of the main meniscus are in good agreement with the experimentally measured values. PMID:26402778

  13. CO2 Capillary-Trapping Processes in Deep Saline Aquifers

    Science.gov (United States)

    Gershenzon, Naum I.; Soltanian, Mohamadreza; Ritzi, Robert W., Jr.; Dominic, David F.

    2014-05-01

    reservoirs. The results strongly suggest that representing these small scales features, and representing how they are organized within a hierarchy of larger-scale features, is critical to understanding capillary trapping processes. References [1] Bridge, J.S. (2006), Fluvial facies models: Recent developments, in Facies Models Revisited, SEPM Spec. Publ., 84, edited by H. W. Posamentier and R. G. Walker, pp. 85-170, Soc. for Sediment. Geol. (SEPM), Tulsa, Okla [2] Ramanathan, R., A. Guin, R.W. Ritzi, D.F. Dominic, V.L. Freedman, T.D. Scheibe, and I.A. Lunt (2010), Simulating the heterogeneity in channel belt deposits: Part 1. A geometric-based methodology and code, Water Resources Research, v. 46, W04515.

  14. Modelling the effect of pore structure and wetting angles on capillary rise in soils having different wettabilities

    Science.gov (United States)

    Czachor, Henryk

    2006-09-01

    SummaryCapillary rise in axis symmetrical sinusoidal capillary (SC) has been modelled. Analytical formula for meniscus radius, capillary pressure and meniscus rate in SC have been found. Capillary shape described by wall waviness highly influences all of them. The limit between wettability and repellency in such capillary is described by critical value of contact angle θc which is related to the pore geometry by the equation ctg( θc) = πd2, where d2 - pore wall waviness. Kinetics of capillary rise in sinusoidal capillary has been determined by numerical integration of meniscus rate equation for a wide range of pore wall waviness and several values of contact angles. Application of Washburn theory to the data obtained from simulation gives the contact angle value much higher than the true one. In contrast, the obtained pore radius value is usually well correlated with capillary neck. However, in some cases a calculated radius can be even smaller. Above conclusions have been qualitatively confirmed by experiments performed on glass beads and soils. Contact angle measured on flat glass was 27.4°. The calculations concerning the data from capillary rise experiments on 90-1000 μm fraction of glass powder and Washburn theory gave values ca. 80°. The contact angle values for peat soils and loamy sand have close values, which supports the opinion that non-cylindrical shape of soil pores highly influences both the wettability/repellency and the water flux in soils.

  15. Sheathless interface for coupling capillary electrophoresis with mass spectrometry

    Science.gov (United States)

    Wang, Chenchen; Tang, Keqi; Smith, Richard D.

    2014-06-17

    A sheathless interface for coupling capillary electrophoresis (CE) with mass spectrometry is disclosed. The sheathless interface includes a separation capillary for performing CE separation and an emitter capillary for electrospray ionization. A portion of the emitter capillary is porous or, alternatively, is coated to form an electrically conductive surface. A section of the emitter capillary is disposed within the separation capillary, forming a joint. A metal tube, containing a conductive liquid, encloses the joint.

  16. Diagnostics of a high current capillary discharge

    International Nuclear Information System (INIS)

    We have demonstrated that thin (10 to 25 μm diameter) capillaries can be fabricated in suitably configured insulators for use in pulse power machines. Large currents can be used to heat these capillaries which produce photons with an energies greater than 1 keV

  17. Pulmonary capillary haemangiomatosis in a premature infant

    International Nuclear Information System (INIS)

    Pulmonary capillary haemangiomatosis (PCH) is a rare disorder characterized by widespread capillary proliferation in the lung, infiltrating the interstitium and the alveolar walls. We present the HRCT features of PCH in a surviving ex-premature infant. To our knowledge, this is a unique case of the radiological features of PCH in a young living infant. (orig.)

  18. Pulmonary capillary haemangiomatosis in a premature infant

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Cicero J.T.A.; Massie, John; Mandelstam, Simone A. [University of Melbourne, Royal Children' s Hospital, Parkville, VIC (Australia)

    2005-06-01

    Pulmonary capillary haemangiomatosis (PCH) is a rare disorder characterized by widespread capillary proliferation in the lung, infiltrating the interstitium and the alveolar walls. We present the HRCT features of PCH in a surviving ex-premature infant. To our knowledge, this is a unique case of the radiological features of PCH in a young living infant. (orig.)

  19. Study of capillary and chemical cover applied to reclamation of uranium mine tailings and rock waste

    International Nuclear Information System (INIS)

    The aim of this work is to evaluate the feasibility and the efficiency of the cover applied to uraniferous mining residues with natural products. The studied cover answers three functions, separately studied: the water input control, the oxygen input and radon output control, the infiltrations chemistry control. The infiltration control will be realized by the implementing of a capillary cover integrating a clayey layer. This layer ensures also the tightness function and limit the radon migration to the atmosphere. By a control of the water input in the storage, the capillary cover minimizes the polluted water bulks and limits the pollutants leaking in the environment. (A.L.B.)

  20. A Unified Elastoplastic Model of Unsaturated Soils Considering Capillary Hysteresis

    Directory of Open Access Journals (Sweden)

    Tiantian Ma

    2013-01-01

    Full Text Available Unlike its saturated counterparts, the mechanical behavior of an unsaturated soil depends not only upon its stress history but also upon its hydraulic history. In this paper, a soil-water characteristic relationship which is capable of describing the effect of capillary hysteresis is introduced to characterize the influence of hydraulic history on the skeletal deformation. The capillary hysteresis is viewed as a phenomenon associated with the internal structural rearrangements in unsaturated soils, which can be characterized by using a set of internal state variables. It is shown that both capillary hysteresis and plastic deformation can be consistently addressed in a unified theoretical framework. Within this context, a constitutive model of unsaturated soils is developed by generalizing the modified Cam-Clay model. A hardening function is introduced, in which both the matric suction and the degree of saturation are explicitly included as hardening variables, so that the effect of hydraulic history on the mechanical response can be properly addressed. The proposed model is capable of capturing the main features of the unsaturated soil behavior. The new model has a hierarchical structure, and, depending upon application, it can describe the stress-strain relation and the soil-water characteristics in a coupled or uncoupled manner.

  1. Underwater capillary discharge with air and oxygen addition

    International Nuclear Information System (INIS)

    The aim of this work was to present an effective method of generating an underwater capillary discharge at low power through gas injection (O2, air) and generating OH radicals. A flowing water (0.1 L/min) discharge was created in a quartz capillary tube (Φ = 4 mm outer; Φ = 2 mm inner; thickness = 2 mm) by applying a continuous negative DC voltage (0 - 4 kV) across tungsten electrodes (Φ = 0.5 mm) separated by a variable distance (1 - 2 mm) in the pin-pin electrode configuration. The air- and oxygen-injected capillary discharges at a constant water flow rate, similar gas injection variation rates, and two different interelectrode gaps were compared. A reduction in the breakdown voltage with increasing gas injection rate was shown. Compared to air, oxygen was proven to be more effective for generating an underwater discharge of a pulsating nature with the characteristics of high energy per pulse, higher power per pulse, short pulse width, and short pulse repetition rate. The emission spectrum of the oxygen-injected discharge showed a higher concentration of OH radicals than that of the air-injected discharge. The imaging diagnostic results showed that the discharge was brighter and more expanded when oxygen was added than it was when air was added.

  2. Generation of intense soft X-rays from capillary discharge plasmas

    Indian Academy of Sciences (India)

    Y B S R Prasad; S Nigam; K Aneesh; S Barnwal; P K Tripathi; P A Naik; C P Navathe; P D Gupta

    2011-06-01

    X-ray lasing through high voltage, high current discharges in gas filled capillaries has been demonstrated in several laboratories. This method gives highest number of X-ray photons per pulse. The fast varying current and the j x B magnetic force compress the plasma towards the axis forming a hot, dense, line plasma, wherein under appropriate discharge conditions lasing occurs. At Laser Plasma Division, RRCAT, a program on high voltage capillary discharge had been started. The system consists of a 400 kV Marx bank, water line capacitor, spark gap and capillary chamber. The initial results of the emission of intense short soft X-ray pulses (5–10 ns) from the capillary discharge are reported.

  3. Changes in capillary filling do not influence inspiratory-induced vasoconstrictive episodes

    Science.gov (United States)

    Rauh, Robert; Ochsmann, Elke; Kessler, Manfred; Mueck-Weymann, Michael

    2007-05-01

    Deep inspiration leads to sympathetically mediated vasoconstriction at the fingertip. This so-called inspiratory gasp response (IGR) is usually assessed by laser Doppler fluxmetry (LDF) and provides interesting information on the activity of the sympathetic nervous system. In this study we investigated if simple maneuvers which affect microcirculation have an effect on the IGR. For this we detected IGR with LDF in rest, after elevation of the arm to lower capillary filling, after venous congestion to increase capillary filling, and after heating up in warm water to induce vasodilation. Capillary filling was monitored with the Erlangen Microlightguide Spectrophotometer (EMPHO) by determination of the relative hemoglobin concentration. We found that IGR was not affected by microcirculatory starting conditions. Therefore, we conclude that diagnostic results of the IGR are not influenced by different capillary filling levels.

  4. Nonlocal resonances in weak turbulence of gravity-capillary waves.

    Science.gov (United States)

    Aubourg, Quentin; Mordant, Nicolas

    2015-04-10

    We report a laboratory investigation of weak turbulence of water surface waves in the gravity-capillary crossover. By using time-space-resolved profilometry and a bicoherence analysis, we observe that the nonlinear processes involve three-wave resonant interactions. By studying the solutions of the resonance conditions, we show that the nonlinear interaction is dominantly one dimensional and involves collinear wave vectors. Furthermore, taking into account the spectral widening due to weak nonlinearity explains why nonlocal interactions are possible between a gravity wave and high-frequency capillary ones. We observe also that nonlinear three-wave coupling is possible among gravity waves, and we raise the question of the relevance of this mechanism for oceanic waves. PMID:25910127

  5. Droplet motion driven by electro-elasto-capillary effects

    Science.gov (United States)

    Shah, Jaymeen; Yang, Xin; Sun, Ying

    2013-11-01

    The motion of droplets on natural and synthetic fibers underlines many technological applications including flexible displays, insulation, and smart filters. However, there is a lack of fundamental understanding of the coupled electrical, elastic, and capillary forces on droplets in fiber networks. In the present study, the motion of a water droplet suspended between two electrically insulated fibers of different Young's modulus, lengths and diameters are examined under electric fields. The results on rigid fibers reveal a critical voltage, under which the droplet remain stationary. Above this critical voltage, droplet self-propulsion is observed as a result of the interplay of electro, elasto and capillary forces on the droplet. The effects of the inter-fiber distance and Young's modulus on droplet motion are also discussed. The controllable motion of droplets can be used to manipulate or transport liquid at small scales.

  6. A combined capillary cooling system for cooling fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Ana Paula; Pelizza, Pablo Rodrigo; Galante, Renan Manozzo; Bazzo, Edson [Universidade Federal de Santa Catarina (LabCET/UFSC), Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica. Lab. de Combustao e Engenharia de Sistemas Termicos], Emails: ana@labcet.ufsc.br, pablo@labcet.ufsc.br, renan@labcet.ufsc.br, ebazzo@emc.ufsc.br

    2010-07-01

    The operation temperature control has an important influence over the PEMFC (Proton Exchange Membrane Fuel Cell) performance. A two-phase heat transfer system is proposed as an alternative for cooling and thermal control of PEMFC. The proposed system consists of a CPL (Capillary Pumped Loop) connected to a set of constant conductance heat pipes. In this work ceramic wick and stainless mesh wicks have been used as capillary structure of the CPL and heat pipes, respectively. Acetone has been used as the working fluid for CPL and deionized water for the heat pipes. Experimental results of three 1/4 inch stainless steel outlet diameter heats pipes and one CPL have been carried out and presented in this paper. Further experiments are planned coupling the proposed cooling system to a module which simulates the fuel cell. (author)

  7. Anion analysis using capillary electrophoresis in the Halden reactor

    International Nuclear Information System (INIS)

    A significant investment has been made over the last decade in water chemistry analysis capability at the Halden Reactor, reflecting both the need to maintain system reliability and to provide chemical analyses for the increasing number of corrosion and chemistry-related experiments being performed in the reactor. Control of concentrations of anionic species (chloride, sulphate and nitrate) is of crucial importance in reducing the potential of stainless steel components to undergo stress corrosion cracking. Currently at Halden, samples must be taken from the coolant in the reactor itself, several auxiliary systems and approximately 10 test loop systems. Previously, anion analyses were performed using ion chromatography. In 1996, this technique was superseded by capillary electrophoresis since the latter has several advantages over the former, including speed of analysis. This paper will present operational experience of using capillary electrophoresis from two different suppliers. A discussion of the advantages and disadvantages of the technique over ion chromatography is included. (author)

  8. Influence of Capillary Bridge Formation onto the Silica Nanoparticle Interaction Studied by Grand Canonical Monte Carlo Simulations

    OpenAIRE

    Leroch, Sabine; Wendland, Martin

    2013-01-01

    Adhesion forces between nanoparticles strongly depend on the amount of adsorbed condensed water from ambient atmosphere. Liquid water forms bridges in the cavities separating the particles, giving rise to the so-called capillary forces which in most cases dominate the van der Waals and long-range electrostatic interactions. Capillary forces promote the undesirable agglomeration of particles to large clusters, thereby hindering the flowability of dry powders in process containers. In process e...

  9. Geometry of the capillary net in human hearts.

    Science.gov (United States)

    Rakusan, K; Cicutti, N; Spatenka, J; Samánek, M

    1997-01-01

    The geometry of the coronary capillary bed in human hearts was studied using samples obtained during cardiac surgery of children operated for tetralogy of Fallot and samples from fresh normal hearts used for valve harvesting. The results revealed a similar coronary capillary density and heterogeneity of capillary spacing in samples from both groups. A double-staining method was used to distinguish between capillary segments close to the feeding arteriole (proximal capillaries) and segments distant from the arteriole (distal capillaries). In both groups of hearts, capillary segment length was consistently shorter on the venular than the arteriolar portion of the capillary. Similarly, capillary domain areas were also smaller and the resulting capillary supply unit was smaller along venular portions compared to arteriolar regions of the capillary bed. This distinctive geometry would provide advantageous geometric conditions for tissue oxygen supply. PMID:9176723

  10. Analysis of Evaporation Heat Transfer of Thin Liquid Film in a Capillary of Equilateral Triangular Cross-Section

    Institute of Scientific and Technical Information of China (English)

    Miao Jianyin; Wang Jinliang; Ma Tongze

    2001-01-01

    In this paper, theoretical analysis on evaporating heat transfer in capillary with equilateral triangular cross section is presented and numerical calculations based on glass-water system are carried out. Considering evaporation mechanism in capillary with polygonal section, one-dimensional model is used to describe the three-dimensional case. The evaporating meniscus in the capillary along axis can be divided into six regions. The following conclusions are obtained: (1) The local heat transfer coefficients and heat fluxes in capillary increase quickly in the first and second regions, and slowly in the third region. The maximum value appears at interline between the third and fourth regions, then gradually decreases in the last three regions. (2) The average heat transfer coefficients decrease when the sizes of the capillary section increase, and become larger under higher wall temperature.

  11. Water Fibers

    CERN Document Server

    Douvidzon, Mark L; Martin, Leopoldo L; Carmon, Tal

    2016-01-01

    Fibers constitute the backbone of modern communication and are used in laser surgeries; fibers also genarate coherent X-ray, guided-sound and supercontinuum. In contrast, fibers for capillary oscillations, which are unique to liquids, were rarely considered in optofluidics. Here we fabricate fibers by water bridging an optical tapered-coupler to a microlensed coupler. Our water fibers are held in air and their length can be longer than a millimeter. These hybrid fibers co-confine two important oscillations in nature: capillary- and electromagnetic-. We optically record vibrations in the water fiber, including an audio-rate fundamental and its 3 overtones in a harmonic series, that one can hear in soundtracks attached. Transforming Micro-Electro-Mechanical-Systems [MEMS] to Micro-Electro-Capillary-Systems [MECS], boosts the device softness by a million to accordingly improve its response to minute forces. Furthermore, MECS are compatible with water, which is a most important liquid in our world.

  12. Effects of intermediate wettability on entry capillary pressure in angular pores.

    Science.gov (United States)

    Rabbani, Harris Sajjad; Joekar-Niasar, Vahid; Shokri, Nima

    2016-07-01

    Entry capillary pressure is one of the most important factors controlling drainage and remobilization of the capillary-trapped phases as it is the limiting factor against the two-phase displacement. It is known that the entry capillary pressure is rate dependent such that the inertia forces would enhance entry of the non-wetting phase into the pores. More importantly the entry capillary pressure is wettability dependent. However, while the movement of a meniscus into a strongly water-wet pore is well-defined, the invasion of a meniscus into a weak or intermediate water-wet pore especially in the case of angular pores is ambiguous. In this study using OpenFOAM software, high-resolution direct two-phase flow simulations of movement of a meniscus in a single capillary channel are performed. Interface dynamics in angular pores under drainage conditions have been simulated under constant flow rate boundary condition at different wettability conditions. Our results shows that the relation between the half corner angle of pores and contact angle controls the temporal evolution of capillary pressure during the invasion of a pore. By deviating from pure water-wet conditions, a dip in the temporal evolution of capillary pressure can be observed which will be pronounced in irregular angular cross sections. That enhances the pore invasion with a smaller differential pressure. The interplay between the contact angle and pore geometry can have significant implications for enhanced remobilization of ganglia in intermediate contact angles in real porous media morphologies, where pores are very heterogeneous with small shape factors. PMID:27042823

  13. An enhanced capillary electrophoresis method for characterizing natural organic matter.

    Science.gov (United States)

    Cottrell, Barbara A; Cheng, Wei Ran; Lam, Buuan; Cooper, William J; Simpson, Andre J

    2013-02-21

    Natural organic matter (NOM) is ubiquitous and is one of the most complex naturally occurring mixtures. NOM plays an essential role in the global carbon cycle; atmospheric and natural water photochemistry; and the long-range transport of trace compounds and contaminants. There is a dearth of separation techniques capable of resolving this highly complex mixture. To our knowledge, this is the first reported use of ultrahigh resolution counterbalance capillary electrophoresis to resolve natural organic matter. The new separation strategy uses a low pH, high concentration phosphate buffer to reduce the capillary electroosmotic flow (EOF). Changing the polarity of the electrodes reverses the EOF to counterbalance the electrophoretic mobility. Sample stacking further improves the counterbalance separation. The combination of these conditions results in an electropherogram comprised up to three hundred peaks superimposed on the characteristic "humic hump" of NOM. Fraction collection, followed by three-dimensional emission excitation spectroscopy (EEMs) and UV spectroscopy generated a distinct profile of fluorescent and UV absorbing components. This enhanced counterbalance capillary electrophoresis method is a potentially powerful technique for the characterization and separation of NOM and complex environmental mixtures in general. PMID:23289095

  14. Determining CO2-brine relative permeability and capillary pressure simultaneously: an insight to capillary entrance and end effects

    Science.gov (United States)

    Chen, X.; Kianinejad, A.; DiCarlo, D. A.

    2014-12-01

    CO2-brine relative permeability relations are important parameters in modeling scenarios such as CO2 sequestration in saline aquifers and CO2 enhanced recovery in oil reservoir. Many steady-state experimental studies on CO2-brine relative permeability showed that the CO2-brine relative permeability differs greatly from typical oil-brine relative permeability. Particularly, they reported a very small endpoint CO2 relative permeability of 0.1~0.2 at a relative high residual water saturation of 0.4~0.6. In this study, we hypothesize the measured low endpoint CO2 relative permeability in previous studies was an experimental artifact that is primary due to low CO2 viscosity. We conducted steady-state CO2 drainage experiments by co-injecting equlibrated CO2 and brine into a long (60.8 cm) and low permeability (116-mD) Berea sandstone core at 20 °C and 1500 psi. During every experiment, both the overall pressure drop across the core and the pressure drops of the five independent and continuous sections of the core were monitored. The in-situ saturation was measured with a medical X-ray Computed Tomography (CT) scanner. In the center three sections where saturation was uniform, we determined the relative permeability to both brine and CO2 phases. In the entrance and exit sections, both measured pressure gradients and saturation were non-uniform. To cope with this, we make several self-consistent assumptions that reveal the nature of capillary entrance and effect in steady-state two-phase core flooding experiments. Based on these assumptions we determined the relative permeability to CO2 and CO2-brine capillary pressure simultaneously using measured pressure drops. We found: (1) a much higher endpoint CO2 relative permeability of 0.58 at a water saturation of 48%, (2) the entrance region with non-uniform saturation expanded CO2 relative permeability data to much lower water saturation, (3) the determined CO2-brine capillary pressure curve is self-consistent and matches

  15. "Getting the best sensitivity from on-capillary fluorescence detection in capillary electrophoresis" - A tutorial.

    Science.gov (United States)

    Galievsky, Victor A; Stasheuski, Alexander S; Krylov, Sergey N

    2016-09-01

    Capillary electrophoresis with Laser-Induced Fluorescence (CE-LIF) detection is being applied to new analytical problems which challenge both the power of CE separation and the sensitivity of LIF detection. On-capillary LIF detection is much more practical than post-capillary detection in a sheath-flow cell. Therefore, commercial CE instruments utilize solely on-capillary CE-LIF detection with a Limit of Detection (LOD) in the nM range, while there are multiple applications of CE-LIF that require pM or lower LODs. This tutorial analyzes all aspects of on-capillary LIF detection in CE in an attempt to identify means for improving LOD of CE-LIF with on-capillary detection. We consider principles of signal enhancement and noise reduction, as well as relevant areas of fluorophore photochemistry and fluorescent microscopy. PMID:27543015

  16. Fast plasma discharge capillary design as a high power throughput soft x-ray emission source

    Energy Technology Data Exchange (ETDEWEB)

    Wyndham, E. S.; Favre, M.; Valdivia, M. P.; Valenzuela, J. C.; Chuaqui, H.; Bhuyan, H. [Facultad de Fisica, Pontificia Universidad Catolica de Chile, Ave. Vicuna Mackenna 4860, Santiago (Chile)

    2010-09-15

    We present the experimental details and results from a low energy but high repetition rate compact plasma capillary source for extreme ultraviolet and soft x-ray research and applications. Two lengths of capillary are mounted in two versions of a closely related design. The discharge operates in 1.6 and 3.2 mm inner diameter alumina capillaries of lengths 21 and 36 mm. The use of water both as dielectric and as coolant simplifies the compact low inductance design with nanosecond discharge periods. The stored electrical energy of the discharge is approximately 0.5 J and is provided by directly charging the capacitor plates from an inexpensive insulated-gate bipolar transistor in 1 {mu}s or less. We present characteristic argon spectra from plasma between 30 and 300 A as well as temporally resolved x-ray energy fluence in discrete bands on axis. The spectra also allow the level of ablated wall material to be gauged and associated with useful capillary lifetime according to the chosen configuration and energy storage. The connection between the electron beams associated with the transient hollow cathode mechanism, soft x-ray output, capillary geometry, and capillary lifetime is reported. The role of these e-beams and the plasma as measured on-axis is discussed. The relation of the electron temperature and the ionization stages observed is discussed in the context of some model results of ionization in a non-Maxwellian plasma.

  17. Observation and Manipulation of a Capillary Jet in a Centrifuge-Based Droplet Shooting Device

    Directory of Open Access Journals (Sweden)

    Kazuki Maeda

    2015-10-01

    Full Text Available We report observation and manipulation of a capillary jet under ultra-high centrifugal gravity in a proposed capillary-based fluidic device for the synthesis of microparticles in a centrifugal tube called Centrifuge-Based Droplet Shooting Device (CDSD. Using a high-speed camera, we directly observed the dripping to jetting transition of a viscous capillary jet of water and Sodium alginate solution generated from a glass capillary-orifice of a diameter of O (100 m under centrifugal gravity ranging from 190 to 450 g. A non-dimensional analysis shows that the mechanism of the dripping-jetting transition in the CDSD may follow that previously reported for a dripping faucet under standard gravity. We also fabricated calcium alginate microparticles by gelating droplets of sodium alginate solution obtained in the break-up of the capillary jet in the jetting regime and demonstrated fabrication of microbeads-on-a-string structures. We confirmed that the jetting regime of the capillary jet could be used to fabricate smaller particles than that of the dripping regime. The results show that the CDSD would be a more useful device to fabricate various polymeric structures and understand the physics of fluid jets under ultra-high gravity.

  18. Chloroform and Carbon Tetrachloride Determination in Drinking Water with Headspace Capillary Column Gas Chromatography%顶空毛细管柱气相色谱法测定生活饮用水中的氯仿和四氯化碳

    Institute of Scientific and Technical Information of China (English)

    袁波; 徐文清

    2014-01-01

    本方法采用顶空气相色谱法,利用毛细管柱、μ-ECD微电子捕获检测器对饮用水中氯仿和四氯化碳残留量进行了检测分析,检出限分别为0.02和0.2μg/L,回收率90.4%~95.6%,本方法分析简便,容易操作。%Residue of chloroform and carbon tetrachloride in drinking water were measured by using headspace gas chromatography with capillary column or μ-ECD microelectronics capture detector. Detection limit was 0.02 and 0.2μg/L, respectively. Recovery was 90.4%-95.6%. This method was simple and sasy.

  19. Technology Solutions Case Study: Capillary Break Beneath a Slab: Polyethylene Sheeting over Aggregate, Southwestern Pennsylvania

    Energy Technology Data Exchange (ETDEWEB)

    None

    2014-07-01

    In this project, Building America team IBACOS worked with a builder of single- and multifamily homes in southwestern Pennsylvania (climate zone 5) to understand its methods of successfully using polyethylene sheeting over aggregate as a capillary break beneath the slab in new construction. This builder’s homes vary in terms of whether they have crawlspaces or basements. However, in both cases, the strategy protects the home from water intrusion via capillary action (e.g., water wicking into cracks and spaces in the slab), thereby helping to preserve the durability of the home.

  20. Capillary electrochromatography using fibers as stationary phases.

    Science.gov (United States)

    Jinno, K; Watanabe, H; Saito, Y; Takeichi, T

    2001-10-01

    Fiber-packed capillary columns have been evaluated in chromatographic performance in capillary electrochromatography (CEC). The change of electroosmotic flow (EOF) velocity and selectivity using different kinds of fiber materials was examined. Although the EOF velocity among the different fiber packed columns was almost the same, retention of parabens was larger on the Kevlar-packed column than on the Zylon-packed one, and was larger on the as-span-type fiber-packed column than on the high-modulus-type packed one. Using 200 microm ID x 5 cm Kevlar packed column combined with a 100 microm ID x 20 cm precolumn capillary and a 530 microm ID x 45 cm postcolumn capillary, the separation of three parabens within 30 s was achieved. Other compounds were also separated in a few minutes by the fiber-packed CEC method. PMID:11669512

  1. Capillary Electrophoresis coupled with Automated Fraction Collection

    OpenAIRE

    Huge, Bonnie Jaskowski; Flaherty, Ryan; Dada, Oluwatosin O.; Dovichi, Norman J.

    2014-01-01

    A fraction collector based on a drop-on-demand ink-jet printer was developed to interface capillary zone electrophoresis with a 96 well microtiter plate. We first evaluated the performance of the collector by using capillary zone electrophoresis to analyze a 1 mM solution of tetramethylrhodamine; a fluorescent microtiter plate reader was then used to detect the analyte and characterize fraction carryover between wells. Relative standard deviation in peak height was 20% and the relative standa...

  2. The capillary electrophoresis of the influenza viruses

    Czech Academy of Sciences Publication Activity Database

    Horká, Marie; Kubesová, Anna; Kubíček, O.; Kubíčková, Z.; Rosenbergová, K.; Šlais, Karel

    Tallinn: Tallinn University of Technology, 2009 - (Borissova, M.; Vaher, M.). s. 93 ISBN 978-9985-59-930-3. [Nordic Separation Science Society (NoSSS) International Conference /5./. 26.08.2009-29.08.2009, Tallinn] R&D Projects: GA AV ČR IAAX00310701 Institutional research plan: CEZ:AV0Z40310501 Keywords : capillary isoelectric focusing * capillary electrophoresis * influenza swine and equine viruses Subject RIV: CB - Analytical Chemistry, Separation

  3. Selectivity and detection in capillary electrophoresis

    OpenAIRE

    Khaled, Maha Yehia

    1994-01-01

    This work is a contribution to the minimization of some of the selectivity and detection limitations in capillary electrophoresis. A more practical design of an electrochemical detector is introduced with simultaneous on-line UV detection (1), for the selective detection of a number of pungent and neurological compounds, the piperines and the capsacinoids. Commercially available microelectrodes together with large 25 μm id fused silica capillary columns are used for the fir...

  4. Vectorial detection of sub-microscale capillary curvature by laser beam profile

    Science.gov (United States)

    Verma, Gopal; Singh, Kamal P.

    2015-10-01

    We demonstrate a simple and non-invasive optical technique to detect direction and magnitude of long-range, sub-microscale capillary curvature of fluid interfaces in various situations. By analyzing magnitude and direction of the distorted spatial profile of the laser beam, following its weak Fresnel's reflection from the air-water interface, ultra-low curvature of 0.1 μm-1 caused by dipped slides, glass tubes, and microscopic twisted silk fibers was measured up to six capillary lengths away from the object. The flexibility of this technique allows us to measure curvature of remotely placed fluid-fluid interfaces and interaction between capillary curves of multiple objects. The high sensitivity of our technique is demonstrated in measuring magnetic susceptibility of water and the full spatial profile of deformation under weak magnetic field. This technique might find applications in precision measurements in optofluidics and interface physics.

  5. Evaluation of capillary pore size characteristics in high-strength concrete at early ages

    International Nuclear Information System (INIS)

    The quantitative scanning electron microscope-backscattered electron (SEM-BSE) image analysis was used to evaluate capillary porosity and pore size distributions in high-strength concretes at early ages. The Powers model for the hydration of cement was applied to the interpretation of the results of image analysis. The image analysis revealed that pore size distributions in concretes with an extremely low water/binder ratio of 0.25 at early ages were discontinuous in the range of finer capillary pores. However, silica-fume-containing concretes with a water/binder ratio of 0.25 had larger amounts of fine pores than did concretes without silica fume. The presence of larger amounts of fine capillary pores in the concretes with silica fume may be responsible for greater autogenous shrinkage in the silica-fume-containing concretes at early ages

  6. Fast & Scalded: Capillary Leidenfrost Droplets in micro-Ratches

    CERN Document Server

    Marin, Alvaro G; Römer, Gert-Willem; Lohse, Detlef

    2013-01-01

    In this Fluid Dynamics Videos submitted to the 31st Gallery of Fluid Motion, we illustrate the special dynamics of capillary self-propelled Leidenfrost droplets in micrometric Ratchets. In order to be able to propel water droplets of sizes of the order of 1 mm, micro-ratchets were produced by direct material removal using a picosecond pulsed laser source. Surface micro-patterning with picosecond laser pulses allows creating a well controlled topography on a variety of substrates, with a resolution typically in the micron range. More information can be found in references.

  7. Ligand-assisted capillary electrophoresis separations of the lanthanides

    International Nuclear Information System (INIS)

    Capillary electrophoresis is used with simple organic ligands added to the electrolyte matrix to achieve separation of the individual lanthanide cations. Results for acetate (AC-) and malonate (MA-) yield good resolution for the lighter lanthanides, but not the heavier lanthanides. In contrast, α-hydroxyisobutyrate (HIB-) gives complete resolution for all of the lanthanide cations. These results are related to the complexation chemistry between the lanthanides and the ligands across the lanthanide series. In addition, preliminary results for lanthanide separations using AC- in mixed methanol:water solvent systems are provided. The presence of methanol improves resolution but slows the separation. (author)

  8. Three-Phase Capillary Pressure, Hysteresis and Trapping in a Porous Glass-Bead Column

    Science.gov (United States)

    Andersson, L.; Schlüter, S.; Li, T.; Brown, K. I.; Helland, J. O.; Wildenschild, D.

    2015-12-01

    Enhanced oil recovery (EOR) strategies employing water-alternate-gas (WAG) injections may improve oil mobility and production recovery. WAG injections for EOR create regions in the reservoir with simultaneous flow of oil, water and air dominated by capillary and gravity forces. As a result of the dynamics in the transition zones, the invading fluid may snap off compartments of the displaced fluid which could then be trapped in the pore space, contributing to the hysteresis of the three-phase capillary pressure curves. Three-phase capillary pressure curves are needed to model the three-phase transition zone movements in the reservoir. In reservoir simulation models, the common practice has been to implement three-phase capillary pressure curves based on two-phase gas-oil and oil-water capillary pressure data. However, experimental and modelling studies of three-phase fluid distributions at the pore scale have shown that this procedure is not always valid; three-phase capillary pressure curves exhibit hysteresis and depend on the saturation history of the three phases which cannot be derived from two-phase capillary pressure curves. We have developed three-phase experiments that provide capillary pressures and 3D-image data of fluid distributions in the entire saturation space of oil, water and air in water-wet porous glass-bead columns; a time-consuming and technically challenging exercise. The 3D data with a resolution of 6.38 μm were derived from high-resolution synchrotron x-ray computed micro-tomography (CMT), collected at the GSECARS beam line 13-BM-D at the Advanced Photon Source, Argonne National Laboratory. In particular, we discuss how three-phase pore-scale mechanisms, such as oil layer existence and multiple displacement events, affect the mobility and trapping of oil in the porous medium. We also show that wettability-alterations of the porous medium in contact with the three-phase fluid system and exposure to x-rays can be avoided by using iodine

  9. Direct measurement of the wetting front capillary pressure in a clay brick ceramic

    International Nuclear Information System (INIS)

    The absorption of a liquid into a rectangular bar of an initially dry porous material that is sealed on all surfaces except the inflow face is analysed in terms of Sharp Front theory. Sharp Front models are developed for both complete and incomplete displacement of air ahead of the advancing wetting front. Experiments are described from which a characteristic capillary potential of the material is obtained by measuring the equilibrium pressure of the air displaced and compressed ahead of the advancing wetting front. Results for the absorption of water and n-heptane by a fired clay brick ceramic suggest that this wetting front capillary pressure (or capillary potential) scales approximately with the surface tension and also that the permeability scales inversely with the liquid viscosity. The pressure of the air trapped in the wetted region is found to be the same as the pressure of the displaced air. For this material the wetting front capillary pressure for water at 20 C is 0.113 MPa, equivalent to a hydraulic tension head of 11.5 m and to a Young-Laplace pore diameter of 2.6 μm. The capillary pressure so measured is apparently a fundamental percolation property of the material that can be interpreted as the air pressure at which liquid phase continuity and unsaturated conductivity both vanish. The method described can be applied generally to porous materials

  10. Capillary fracture of soft gels.

    Science.gov (United States)

    Bostwick, Joshua B; Daniels, Karen E

    2013-10-01

    A liquid droplet resting on a soft gel substrate can deform that substrate to the point of material failure, whereby fractures develop on the gel surface that propagate outwards from the contact line in a starburst pattern. In this paper, we characterize (i) the initiation process, in which the number of arms in the starburst is controlled by the ratio of the surface tension contrast to the gel's elastic modulus, and (ii) the propagation dynamics showing that once fractures are initiated they propagate with a universal power law L[proportional]t(3/4). We develop a model for crack initiation by treating the gel as a linear elastic solid and computing the deformations within the substrate from the liquid-solid wetting forces. The elastic solution shows that both the location and the magnitude of the wetting forces are critical in providing a quantitative prediction for the number of fractures and, hence, an interpretation of the initiation of capillary fractures. This solution also reveals that the depth of the gel is an important factor in the fracture process, as it can help mitigate large surface tractions; this finding is confirmed with experiments. We then develop a model for crack propagation by considering the transport of an inviscid fluid into the fracture tip of an incompressible material and find that a simple energy-conservation argument can explain the observed material-independent power law. We compare predictions for both linear elastic and neo-Hookean solids, finding that the latter better explains the observed exponent. PMID:24229192

  11. Method of analysis and quality-assurance practices for determination of pesticides in water by solid-phase extraction and capillary-column gas chromatography/mass spectrometry at the U.S. Geological Survey California District Organic Chemistry Laboratory, 1996-99

    Science.gov (United States)

    Crepeau, Kathryn L.; Baker, Lucian M.; Kuivila, Kathryn M.

    2000-01-01

    A method of analysis and quality-assurance practices were developed to study the fate and transport of pesticides in the San Francisco Bay-Estuary by the U.S. Geological Survey. Water samples were filtered to remove suspended-particulate matter and pumped through C-8 solid-phase extraction cartridges to extract the pesticides. The cartridges were dried with carbon dioxide and the pesticides were eluted with three cartridge volumes of hexane:diethyl ether (1:1) solution. The eluants were analyzed using capillary-column gas chromatography/mass spectrometry in full-scan mode. Method detection limits for pesticides ranged from 0.002 to 0.025 microgram per liter for 1-liter samples. Recoveries ranged from 44 to 140 percent for 25 pesticides in samples of organic-free reagent water and Sacramento-San Joaquin Delta and Suisun Bay water fortified at 0.05 and 0.50 microgram per liter. The estimated holding time for pesticides after extraction on C-8 solid-phase extraction cartridges ranged from 10 to 257 days.

  12. Pulsed current wave shaping with a transmission line by utilizing superposition of a forward and a backward voltage wave for fast capillary Z-pinch discharge

    International Nuclear Information System (INIS)

    By using a water transmission line, current wave shaping was demonstrated for a fast capillary Z-pinch discharge recombination soft x-ray laser study. The pulsed power system consists of a water capacitor, a gap switch, a transmission line, and a capillary plasma load. A voltage wave initiated at the water capacitor propagates toward the capillary load through the transmission line. Control of the pulse delay that occurred in the transmission line provides the superposition of the forward and the backward voltage waves effectively in order to perform current wave shaping with higher current amplitude and rapid current decay.

  13. Use of capillary electrophoresis and indirect detection to quantitate in-capillary enzyme-catalyzed microreactions.

    Science.gov (United States)

    Zhang, Y; el-Maghrabi, M R; Gomez, F A

    2000-04-01

    The use of capillary electrophoresis and indirect detection to quantify reaction products of in-capillary enzyme-catalyzed microreactions is described. Migrating in a capillary under conditions of electrophoresis, plugs of enzyme and substrate are injected and allowed to react. Capillary electrophoresis is subsequently used to measure the extent of reaction. This technique is demonstrated using two model systems: the conversion of fructose-1,6-bisphosphate to dihydroxyacetone phosphate and glyceraldehyde-3-phosphate by fructose-biphosphate aldolase (ALD, EC 4.1.2.13), and the conversion of fructose-1,6-bisphosphate to fructose-6-phosphate by fructose-1,6-bisphospatase (FBPase, EC 3.1.3.11). These procedures expand the use of the capillary as a microreactor and offer a new approach to analyzing enzyme-mediated reactions. PMID:10892022

  14. A Novel Polybrene/Chondroitin Sulfate C Double Coated Capillary and Its Application in Capillary Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    DU,Ying-Xiang(杜迎翔); HONDA,Susumu; TAGA,Atsushi; LIU,Wen-Ying(刘文英); SUZUKI,Shigeo

    2002-01-01

    A new capillary coated by double polymer, polybrene/chondroitin sulfate C (P/CC), was developed using a simple procedure. The P/CC double coated capillary showed long lifetime,strong chemical stability and good reproducibility. It endured during more than 100 replicated analyses and was also tolerant to HCl (1 mol/L), NaOH (0.01 mol/L), CH3OH and CH3CN. The P/CC double coated capillary can be applied to basic drug analyses. The adsorption of basic drugs to the capillary wall was suppressed and the peak tailing greatly decreased. The use of the P/CC double coated capillary allowed excelent separation of the enantiomers of some basic drugs by using chondroitin sulfate C as the chiral selector, ami the peak symmetry of basic drugs was further improved under these conditions.

  15. Nanoparticle-based capillary electroseparation of proteins in polymer capillaries under physiological conditions

    DEFF Research Database (Denmark)

    Nilsson, C.; Harwigsson, I.; Becker, K.;

    2010-01-01

    of nanoparticles, i.e. in CE mode, the protein samples adsorbed completely to the capillary walls and could not be recovered. In contrast, nanoparticle-based capillary electroseparation resolved green fluorescent protein from several of its impurities within I min. Furthermore, a mixture of native green...... fluorescent protein and two of its single-amino-acid-substituted variants was separated within 2.5 min with efficiencies of 400 000 plates/m. The nanoparticles prevent adsorption by introducing a large interacting surface and by obstructing the attachment of the protein to the capillary wall. A one......Totally porous lipid-based liquid crystalline nanoparticles were used as pseudostationary phase for capillary electroseparation with LIF detection of proteins at physiological conditions using unmodified cyclic olefin copolymer capillaries (Topas (R), 6.7 cm effective length). In the absence...

  16. Capillary-Tube Model and Experiment of Multiphase Flow in Capillary Fringes

    Institute of Scientific and Technical Information of China (English)

    武晓峰; 唐杰; 吕贤弼

    2002-01-01

    Contamination of soil and groundwater by organic substances is causing more and more problems worldwide. Analysis of the movement and distribution of nonaqueous phase liquids (NAPLs) in subsurface domain is critical for contaminant remediation. Two-dimensional experiments were conducted in a transparent plexiglass trough (105.0 cm×70.0 cm×1.5 cm) to simulate the release and redistribution of gasoline and kerosene in porous media. The results show that before the contaminant distribution reaches equilibrium, the movement of light NAPLs (LNAPLs) can be divided into four sub-stages. After the contaminant front reaches the upper boundary of the capillary fringe, contaminant movement along the upper boundary of the capillary fringe is the primary transport process. Most of the contaminants then move into the capillary fringe except for the residual part. One-dimensional and two-dimensional capillary tube models were developed to analyze the movement of LNAPLs in the capillary fringe.

  17. Constant pressure-assisted head-column field-amplified sample injection in combination with in-capillary derivatization for enhancing the sensitivity of capillary electrophoresis.

    Science.gov (United States)

    Yan, Na; Zhou, Lei; Zhu, Zaifang; Zhang, Huige; Zhou, Ximin; Chen, Xingguo

    2009-05-15

    In this work, a novel method combining constant pressure-assisted head-column field-amplified sample injection (PA-HC-FASI) with in-capillary derivatization was developed for enhancing the sensitivity of capillary electrophoresis. PA-HC-FASI uses an appropriate positive pressure to counterbalance the electroosmotic flow in the capillary column during electrokinetic injection, while taking advantage of the field amplification in the sample matrix and the water of the "head column". Accordingly, the analytes were stacked at the stationary boundary between water and background electrolyte. After 600s PA-HC-FASI, 4-fluoro-7-nitro-2,1,3-benzoxadiazole as derivatization reagent was injected, followed by an electrokinetic step (5kV, 45s) to enhance the mixing efficiency of analytes and reagent plugs. Standing a specified time of 10min for derivatization reaction under 35 degrees C, then the capillary temperature was cooled to 25 degrees C and the derivatives were immediately separated and determined under 25 degrees C. By investigating the variables of the presented approach in detail, on-line preconcentration, derivatization and separation could be automatically operated in one run and required no modification of current CE commercial instrument. Moreover, the sensitivity enhancement factor of 520 and 800 together with the detection limits of 16.32 and 6.34pg/mL was achieved for model compounds: glufosinate and aminomethylphosphonic acid, demonstrating the high detection sensitivity of the presented method. PMID:19342058

  18. Experimental investigation of bubble formation during capillary filling of SiO2 nanoslits

    DEFF Research Database (Denmark)

    Thamdrup, Lasse Højlund; Persson, Karl Fredrik; Bruus, Henrik;

    2007-01-01

    Experimental results are presented regarding the influence of bubble formation on the capillary filling speed of water in SiO2 nanoslits with heights ranging from 33 to 158 nm. The formation of an isolated pinned bubble in a nanoslit with a height of 111 nm causes an immediate decrease in the...

  19. Capillary Waves on the Surface of Simple Liquids Measured by X-Ray Reflectivity

    OpenAIRE

    Braslau, A.; Pershan, Peter S.; Swislow, G.; Ocko, B.M.; Als-Nielsen, J.

    1988-01-01

    The properties of the liquid-vapor interface for three simple liquids (water, carbon tetrachloride, and methanol) have been measured using x-ray reflectivity. The measured surface roughness is interpreted using a model that combines the effects of thermally induced capillary waves and the dimensions of the constituent molecules.

  20. On the regularity of the flow map for the gravity-capillary equations

    OpenAIRE

    Chen, Robin Ming; Marzuola, Jeremy L.; Spirn, Daniel; Wright, J. Douglas

    2011-01-01

    We prove via explicitly constructed initial data that solutions to the gravity-capillary wave system in $\\mathbb{R}^3$ representing a 2d air-water interface immediately fails to be $C^3$ with respect to the initial data if the initial data $(h_0, \\psi_0) \\in H^{s+\\frac12} \\otimes H^{s}$ for $s

  1. The capillary hysteresis model HYSTR: User's guide

    International Nuclear Information System (INIS)

    The potential disposal of nuclear waste in the unsaturated zone at Yucca Mountain, Nevada, has generated increased interest in the study of fluid flow through unsaturated media. In the near future, large-scale field tests will be conducted at the Yucca Mountain site, and work is now being done to design and analyze these tests. As part of these efforts a capillary hysteresis model has been developed. A computer program to calculate the hysteretic relationship between capillary pressure φ and liquid saturation (S1) has been written that is designed to be easily incorporated into any numerical unsaturated flow simulator that computes capillary pressure as a function of liquid saturation. This report gives a detailed description of the model along with information on how it can be interfaced with a transport code. Although the model was developed specifically for calculations related to nuclear waste disposal, it should be applicable to any capillary hysteresis problem for which the secondary and higher order scanning curves can be approximated from the first order scanning curves. HYSTR is a set of subroutines to calculate capillary pressure for a given liquid saturation under hysteretic conditions

  2. Synthetic Capillaries to Control Microscopic Blood Flow

    Science.gov (United States)

    Sarveswaran, K.; Kurz, V.; Dong, Z.; Tanaka, T.; Penny, S.; Timp, G.

    2016-02-01

    Capillaries pervade human physiology. The mean intercapillary distance is only about 100 μm in human tissue, which indicates the extent of nutrient diffusion. In engineered tissue the lack of capillaries, along with the associated perfusion, is problematic because it leads to hypoxic stress and necrosis. However, a capillary is not easy to engineer due to its complex cytoarchitecture. Here, it is shown that it is possible to create in vitro, in about 30 min, a tubular microenvironment with an elastic modulus and porosity consistent with human tissue that functionally mimicks a bona fide capillary using “live cell lithography”(LCL) to control the type and position of cells on a composite hydrogel scaffold. Furthermore, it is established that these constructs support the forces associated with blood flow, and produce nutrient gradients similar to those measured in vivo. With LCL, capillaries can be constructed with single cell precision—no other method for tissue engineering offers such precision. Since the time required for assembly scales with the number of cells, this method is likely to be adapted first to create minimal functional units of human tissue that constitute organs, consisting of a heterogeneous population of 100-1000 cells, organized hierarchically to express a predictable function.

  3. EUV radiation from nitrogen capillary discharge

    Science.gov (United States)

    Frolov, Oleksandr; Kolacek, Karel; Schmidt, Jiri; Straus, Jaroslav

    2014-08-01

    In the last decade EUV sources attract interest from researchers over the world. One of the main motivations is EUV lithography, which could lead to further miniaturization in electronics. Nitrogen recombination laser at wavelength of 13.4 nm based on capillary discharge Z-pinch configuration could be used in experiments with testing of resolution of photoresist for EUV lithography (close to wavelength of 13.5 nm Si/Mo multilayer mirrors have a high reflectivity at normal incidence angles). In this work, pinching of nitrogen-filled capillary discharge is studied for the development of EUV laser, which is based on recombination pumping scheme. The goal of this study is achieving the required plasma conditions using a capillary discharge Z-pinch apparatus. In experiments with nitrogen, the capillary length was shortened from 232 mm to 90 mm and current quarter-period was changed from 60 ns to 50 ns in contrast with early experiments with Ne-like argon laser. EUV radiation from capillary discharge was registered by X-ray vacuum diode for different pressure, amplitude and duration of pre-pulse and charging voltage of the Marx generator.

  4. Analysis of hydrosoluble organic chelating agents. Potentialities of capillary electrophoresis and ionic chromatography

    International Nuclear Information System (INIS)

    Capillary electrophoresis and ion exchange chromatography are good techniques for the determination of organic chelating agents as mono or poly-carboxylates. Ion exchange chromatography allows to obtain very high sensitivities (a few μg/L). Capillary electrophoresis generates practically none analytical waste; this technique is then very interesting for nuclear industry. This microanalysis technique has been here carried out for the determination of organic chelating agents in leaching water of an old waste for which an important release rate of radio-toxic metals had been found. Thus, formate and especially acetate ions have been correlated with this unusual behaviour

  5. Influence of the nature of interfaces on the capillary transport in layered materials

    DEFF Research Database (Denmark)

    Derluyn, Hannelore; Janssen, Hans; Carmeliet, Jan

    2011-01-01

    This paper presents an experimental and quantitative analysis of capillary transport across the interface brick–mortar joint in masonry. Moisture profiles are measured with X-ray projection. The influence of curing conditions is analyzed by considering three types of mortars: cured in a mould......, between capillary wet and dry bricks. A decrease in moisture inflow for the mortars cured between bricks is measured. The pore structure and the moisture transport properties of mortar change significantly due to water extraction from the initially wet mortar to the bricks during curing. Numerical...... simulations reveal the existence of a hydraulic interface resistance between brick and wet/dry cured mortar....

  6. Confinement Correction to Mercury Intrusion Capillary Pressure of Shale Nanopores

    Science.gov (United States)

    Wang, Sen; Javadpour, Farzam; Feng, Qihong

    2016-02-01

    We optimized potential parameters in a molecular dynamics model to reproduce the experimental contact angle of a macroscopic mercury droplet on graphite. With the tuned potential, we studied the effects of pore size, geometry, and temperature on the wetting of mercury droplets confined in organic-rich shale nanopores. The contact angle of mercury in a circular pore increases exponentially as pore size decreases. In conjunction with the curvature-dependent surface tension of liquid droplets predicted from a theoretical model, we proposed a technique to correct the common interpretation procedure of mercury intrusion capillary pressure (MICP) measurement for nanoporous material such as shale. Considering the variation of contact angle and surface tension with pore size improves the agreement between MICP and adsorption-derived pore size distribution, especially for pores having a radius smaller than 5 nm. The relative error produced in ignoring these effects could be as high as 44%—samples that contain smaller pores deviate more. We also explored the impacts of pore size and temperature on the surface tension and contact angle of water/vapor and oil/gas systems, by which the capillary pressure of water/oil/gas in shale can be obtained from MICP. This information is fundamental to understanding multiphase flow behavior in shale systems.

  7. Confinement Correction to Mercury Intrusion Capillary Pressure of Shale Nanopores

    Science.gov (United States)

    Wang, Sen; Javadpour, Farzam; Feng, Qihong

    2016-01-01

    We optimized potential parameters in a molecular dynamics model to reproduce the experimental contact angle of a macroscopic mercury droplet on graphite. With the tuned potential, we studied the effects of pore size, geometry, and temperature on the wetting of mercury droplets confined in organic-rich shale nanopores. The contact angle of mercury in a circular pore increases exponentially as pore size decreases. In conjunction with the curvature-dependent surface tension of liquid droplets predicted from a theoretical model, we proposed a technique to correct the common interpretation procedure of mercury intrusion capillary pressure (MICP) measurement for nanoporous material such as shale. Considering the variation of contact angle and surface tension with pore size improves the agreement between MICP and adsorption-derived pore size distribution, especially for pores having a radius smaller than 5 nm. The relative error produced in ignoring these effects could be as high as 44%—samples that contain smaller pores deviate more. We also explored the impacts of pore size and temperature on the surface tension and contact angle of water/vapor and oil/gas systems, by which the capillary pressure of water/oil/gas in shale can be obtained from MICP. This information is fundamental to understanding multiphase flow behavior in shale systems. PMID:26832445

  8. Confinement Correction to Mercury Intrusion Capillary Pressure of Shale Nanopores.

    Science.gov (United States)

    Wang, Sen; Javadpour, Farzam; Feng, Qihong

    2016-01-01

    We optimized potential parameters in a molecular dynamics model to reproduce the experimental contact angle of a macroscopic mercury droplet on graphite. With the tuned potential, we studied the effects of pore size, geometry, and temperature on the wetting of mercury droplets confined in organic-rich shale nanopores. The contact angle of mercury in a circular pore increases exponentially as pore size decreases. In conjunction with the curvature-dependent surface tension of liquid droplets predicted from a theoretical model, we proposed a technique to correct the common interpretation procedure of mercury intrusion capillary pressure (MICP) measurement for nanoporous material such as shale. Considering the variation of contact angle and surface tension with pore size improves the agreement between MICP and adsorption-derived pore size distribution, especially for pores having a radius smaller than 5 nm. The relative error produced in ignoring these effects could be as high as 44%--samples that contain smaller pores deviate more. We also explored the impacts of pore size and temperature on the surface tension and contact angle of water/vapor and oil/gas systems, by which the capillary pressure of water/oil/gas in shale can be obtained from MICP. This information is fundamental to understanding multiphase flow behavior in shale systems. PMID:26832445

  9. Microjet formation in a capillary by laser-induced cavitation

    Science.gov (United States)

    Peters, Ivo R.; Tagawa, Yoshiyuki; van der Meer, Devaraj; Prosperetti, Andrea; Sun, Chao; Lohse, Detlef

    2010-11-01

    A vapor bubble is created by focusing a laser pulse inside a capillary that is partially filled with water. Upon creation of the bubble, a shock wave travels through the capillary. When this shock wave meets the meniscus of the air-water interface, a thin jet is created that travels at very high speeds. A crucial ingredient for the creation of the jet is the shape of the meniscus, which is responsible for focusing the energy provided by the shock wave. We examine the formation of this jet numerically using a boundary integral method, where we prepare an initial interface at rest inside a tube with a diameter ranging from 50 to 500 μm. To simulate the effect of the bubble we then apply a short, strong pressure pulse, after which the jet forms. We investigate the influence of the shape of the meniscus, and pressure amplitude and duration on the jet formation. The jet shape and velocity obtained by the simulation compare well with experimental data, and provides good insight in the origin of the jet.

  10. Preliminary capillary hysteresis simulations in fractured rocks, Yucca Mountain, Nevada

    Science.gov (United States)

    Niemi, A.; Bodvarsson, G. S.

    1988-12-01

    Preliminary simulations have been carried out to address the question of how hysteretic (history-dependent) capillary pressure-liquid saturation relation may affect the flow and liquid saturation distribution in a fractured rock system. Using a hysteresis model modified from the theoretically based dependent domain model of Mualem (1984), a system consisting of discrete fractures and rock matrix parts was simulated under periodically occurring infiltration pulses. Comparisons were made between the hysteretic case and the non-hysteretic case using the main drying curve alone. Material properties used represent values reported for the densely welded tuffs at Yucca Mountain, Nevada. Since no actual hysteresis measurements were available for the welded tuffs, the necessary data was derived based on information available in the soils literature The strongly hysteretic behavior in the uppermost layer of the matrix along with the overall lower matrix capillary suctions, generated higher fracture flows and a more "smeared" matrix liquid saturation vs. depth distribution for the hysteretic case. While the actual amounts of water being absorbed into the matrix were very similar, the distributions of this absorbed water were different and the matrix was affected up to greater depths in the hysteretic case in comparison to the non-hysteretic case.

  11. METHOD 521: DETERMINATION OF NITROSAMINES IN DRINKING WATER BY SOLID PHASE EXTRACTION AND CAPILLARY COLUMN GAS CHROMATOGRAPHY WITH LARGE VOLUME INJECTION AND CHEMICAL IONIZATION TANDEM MASS SPECTROMETRY (MS/MS)

    Science.gov (United States)

    NDMA is an emerging drinking water contaminant that is of interest to EPA and the environmental community. Its presence in drinking water is a potential health concern, because the EPA's IRIS data base lists the concentration of NDMA required to result in a one in one million li...

  12. Novel absorption detection techniques for capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Y.

    1994-07-27

    Capillary electrophoresis (CE) has emerged as one of the most versatile separation methods. However, efficient separation is not sufficient unless coupled to adequate detection. The narrow inner diameter (I.D.) of the capillary column raises a big challenge to detection methods. For UV-vis absorption detection, the concentration sensitivity is only at the {mu}M level. Most commercial CE instruments are equipped with incoherent UV-vis lamps. Low-brightness, instability and inefficient coupling of the light source with the capillary limit the further improvement of UV-vis absorption detection in CE. The goals of this research have been to show the utility of laser-based absorption detection. The approaches involve: on-column double-beam laser absorption detection and its application to the detection of small ions and proteins, and absorption detection with the bubble-shaped flow cell.

  13. Capillary filling in closed end nanochannels.

    Science.gov (United States)

    Phan, Vinh Nguyen; Nguyen, Nam-Trung; Yang, Chun; Joseph, Pierre; Djeghlaf, Lyes; Bourrier, David; Gue, Anne-Marie

    2010-08-17

    We investigated the interactions between liquid, gas, and solid phases in the capillary filling process of closed-end nanochannels. This paper presents theoretical models without and with absorption and diffusion of gas molecules in the liquid. Capillary filling experiments were carried out in closed-end silicon nanochannels with different lengths. The theoretical and measured characteristics of filling length versus time are compared. The results show that the filling process consists of two stages. The first stage resembles the capillary filling process in an open-end nanochannel. However, a remarkable discrepancy between the experimental results and the theory without gas absorption is observed in the second stage. A closer investigation of the second stage reveals that the dissolution of gas in the liquid is important and can be explained by the model with gas absorption and diffusion. PMID:20695566

  14. Determination of Benzenes in the Drinking Water after Carbon Disulfide Extracting by Capillary Column Gas Chromatography%二硫化碳萃取毛细管柱气相色谱法测定饮用水中苯系物

    Institute of Scientific and Technical Information of China (English)

    陈军; 朱建丰; 封蓉芳

    2011-01-01

    Objective:To develop a method for determining the benzenes in drinking water by capillary column gas chromatography.Methods: Used carbon disulfide to extract the benzenes in drinking water,Gas chromatography separation and detection.Results: The recoverie%目的:建立二硫化碳萃取毛细管柱气相色谱法测定饮用水中苯系物的方法。方法:用二硫化碳萃取饮用水中的苯系物,气相色谱法进行分离检测。结果:7种苯系物的加标回收率在87.0%~111.3%之间,在0.01~1.0mg/L之间线性关系良好。相对标准偏差(RSD)在3.2%~9.3%之间。结论:该方法简单、快速、准确、灵敏,适用于饮用水中苯系物的测定。

  15. Capillary interactions in nano-particle suspensions

    International Nuclear Information System (INIS)

    We have investigated the structures formed by colloidal particles suspended in solvents at volume fractions below 10% and interacting through capillary bridges. Such systems resemble colloidal gas of sticky nano-spheres that form pearl-necklace like chains that, in turn, induce strong viscoelasticity due to the formation of 3-D fractal network. The capillary force dominates the electrostatic and Van der Waals forces in solutions and can bridge multiple particles depending of the volume of the capillary bridge. We have investigated the morphology of the structures formed at different fractions of the bridging fluid. Small-angle neutron scattering (SANS) is used to study nanoparticles with an average diameter of 10 nm in polar and non-polar organic solvents at ambient temperatures. SANS intensity as a function of the scattering vector is analyzed as a product of a form factor, that depends on the particle shape, and a structure factor, that characterizes the interparticle inter reactions. The interaction of particles in polar solvents is considered to be through electrostatic repulsion and the data is successfully fitted by Hayter-Penfold mean spherical approximation (HPMSA). Computer simulations of a pearl necklace-like chain of spheres is conducted to explain the structure factor when capillary bridges are present. Alternatively, we have analyzed the slope of the intensity at low scattering vector in a double logarithmic plot to determine the dimension of the fractal structures formed by the particles at different volume fraction of the bridging fluid. We have also studied the properties of the capillary bridge between a pair of particles. The significance of this study is to explore the possibility of using capillary force as a tool to engineer new colloidal structures and materials in solutions and to optimize their viscoelastic properties. (author)

  16. Burst behavior at a capillary tip: Effect of low and high surface tension.

    Science.gov (United States)

    Agonafer, Damena D; Lopez, Ken; Palko, James W; Won, Yoonjin; Santiago, Juan G; Goodson, Kenneth E

    2015-10-01

    Liquid retention in micron and millimeter scale devices is important for maintaining stable interfaces in various processes including bimolecular separation, phase change heat transfer, and water desalination. There have been several studies of re-entrant geometries, and very few studies on retaining low surface tension liquids such as fluorocarbon-based dielectric liquids. Here, we study retention of a liquid with very low contact angles using borosilicate glass capillary tips. We analyzed capillary tips with outer diameters ranging from 250 to 840 μm and measured Laplace pressures up to 2.9 kPa. Experimental results agree well with a numerical model that predicts burst pressure (the maximum Laplace pressure for liquid retention), which is a function of the outer diameter (D) and capillary exit edge radius of curvature (r). PMID:26046980

  17. Fabrication of axicon microlenses on capillaries and microstructured fibers by wet etching.

    Science.gov (United States)

    Bachus, Kyle; Filho, Elton Soares de Lima; Wlodarczyk, Kamila; Oleschuk, Richard; Messaddeq, Younes; Loock, Hans-Peter

    2016-09-01

    A facile method is presented for the fabrication of microlenses at the facet of fused silica capillaries and microstructured fibers. After submersion in hydrogen fluoride solution water is pumped slowly through the center hole of the capillary microchannel to create an etchant gradient extending from the capillary axis. The desired axicon angle is generated by adjusting the etching time and/or concentration of the etchant. Similarly, flow- assisted HF etching of a custom microstructured fiber containing nine microchannels produces nine individual microlenses simultaneously at the fiber facet, where each microaxicon lens shows a similar focusing pattern. A theoretical model of the flow-assisted etching process is used to determine the axicon angle and post angle. Also, a simple ray-based model was applied to characterize the focusing properties of the microaxicons in good agreement with experimental observations. PMID:27607641

  18. A single-probe capillary microgripper induced by dropwise condensation and inertial release

    Science.gov (United States)

    Fan, Zenghua; Rong, Weibin; Wang, Lefeng; Sun, Lining

    2015-11-01

    A micromanipulation method based on liquid droplets is widely used as a non-destructive technology to pick-and-place micrometer-scale objects. We focus on the development of a single-probe capillary microgripper to execute reliable micromanipulation tasks. By controlling dropwise condensation on a probe tip, the water droplet volume on the hydrophobic tip surface can be varied dynamically, which helps establish appropriate capillary lifting forces during capturing tasks. An inertia-releasing strategy was utilized to implement a piezoelectric actuator integrated with the capillary microgripper and to address release problems caused by adhesion force action. The influence of droplet formation and the capillary lifting force generated during the manipulation process were characterized experimentally. Micromanipulation tests were conducted using a customized motion platform with viewing microscopes to verify the performance potential of the capillary microgripping tool. Experimental results indicated that polystyrene microspheres with 20-100 μm radii and micro-silicon chips (1.63-12.1 μN) were grasped reliably, and that adhered micro-objects could be placed on a target using the proposed microhandling technique of inertial release in ambient conditions.

  19. Biodegradation of phenol, salicylic acid, benzenesulfonic acid, and iomeprol by Pseudomonas fluorescens in the capillary fringe.

    Science.gov (United States)

    Hack, Norman; Reinwand, Christian; Abbt-Braun, Gudrun; Horn, Harald; Frimmel, Fritz H

    2015-12-01

    Mass transfer and biological transformation phenomena in the capillary fringe were studied using phenol, salicylic acid, benzenesulfonic acid, and the iodinated X-ray contrast agent iomeprol as model organic compounds and the microorganism strain Pseudomonas fluorescens. Three experimental approaches were used: Batch experiments (uniform water saturation and transport by diffusion), in static columns (with a gradient of water saturation and advective transport in the capillaries) and in a flow-through cell (with a gradient of water saturation and transport by horizontal and vertical flow: 2-dimension flow-through microcosm). The reactors employed for the experiments were filled with quartz sand of defined particle size distribution (dp=200...600 μm, porosity ε=0.42). Batch experiments showed that phenol and salicylic acid have a high, whereas benzenesulfonic acid and iomeprol have a quite low potential for biodegradation under aerobic conditions and in a matrix nearly close to water saturation. Batch experiments under anoxic conditions with nitrate as electron acceptor revealed that the biodegradation of the model compounds was lower than under aerobic conditions. Nevertheless, the experiments showed that the moisture content was also responsible for an optimized transport in the liquid phase of a porous medium. Biodegradation in the capillary fringe was found to be influenced by both the moisture content and availability of the dissolved substrate, as seen in static column experiments. The gas-liquid mass transfer of oxygen also played an important role for the biological activity. In static column experiments under aerobic conditions, the highest biodegradation was found in the capillary fringe (e.g. βt/β0 (phenol)=0 after t=6 d) relative to the zone below the water table and unsaturated zone. The highest biodegradation occurred in the flow-through cell experiment where the height of the capillary fringe was largest. PMID:26529301

  20. Biodegradation of phenol, salicylic acid, benzenesulfonic acid, and iomeprol by Pseudomonas fluorescens in the capillary fringe

    Science.gov (United States)

    Hack, Norman; Reinwand, Christian; Abbt-Braun, Gudrun; Horn, Harald; Frimmel, Fritz H.

    2015-12-01

    Mass transfer and biological transformation phenomena in the capillary fringe were studied using phenol, salicylic acid, benzenesulfonic acid, and the iodinated X-ray contrast agent iomeprol as model organic compounds and the microorganism strain Pseudomonas fluorescens. Three experimental approaches were used: Batch experiments (uniform water saturation and transport by diffusion), in static columns (with a gradient of water saturation and advective transport in the capillaries) and in a flow-through cell (with a gradient of water saturation and transport by horizontal and vertical flow: 2-dimension flow-through microcosm). The reactors employed for the experiments were filled with quartz sand of defined particle size distribution (dp = 200…600 μm, porosity ε = 0.42). Batch experiments showed that phenol and salicylic acid have a high, whereas benzenesulfonic acid and iomeprol have a quite low potential for biodegradation under aerobic conditions and in a matrix nearly close to water saturation. Batch experiments under anoxic conditions with nitrate as electron acceptor revealed that the biodegradation of the model compounds was lower than under aerobic conditions. Nevertheless, the experiments showed that the moisture content was also responsible for an optimized transport in the liquid phase of a porous medium. Biodegradation in the capillary fringe was found to be influenced by both the moisture content and availability of the dissolved substrate, as seen in static column experiments. The gas-liquid mass transfer of oxygen also played an important role for the biological activity. In static column experiments under aerobic conditions, the highest biodegradation was found in the capillary fringe (e.g. βt/β0 (phenol) = 0 after t = 6 d) relative to the zone below the water table and unsaturated zone. The highest biodegradation occurred in the flow-through cell experiment where the height of the capillary fringe was largest.

  1. A lymph nodal capillary-cavernous hemangioma.

    Science.gov (United States)

    Dellachà, A; Fulcheri, E; Campisi, C

    1999-09-01

    A capillary-cavernous hemangioma in an obturator lymph node was found incidentally in a 64 year-old woman who had undergone unilateral salpingo-oophorectomy and lymphadenectomy for an ovarian neoplasm. Vascular tumors of lymph nodes are briefly reviewed including eight previously described nodal capillary-cavernous hemangiomas. The association with other splanchnic hemangiomas is pointed out and the likelihood that the lesion is a hamartoma rather than a true neoplasm is addressed. Despite its rarity, this entity needs to be recognized by lymphologists who image lymph nodes by lymphangiography as well as by lymph nodal pathologists. PMID:10494525

  2. Intracerebral Capillary Hemangioma: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Youn, In Young; Kim, Jae Kyun; Byun, Jun Soo [Dept. of Radiology, Chung Ang University Medical Center, Chung Ang University College of Medicine, Seoul (Korea, Republic of); Park, Eon Sub [Dept. of Radiology, Chung Ang University Medical Center, Chung Ang University College of Medicine, Seoul (Korea, Republic of)

    2012-01-15

    Intracerebral capillary hemangiomas are very rare benign vascular tumors that mostly occur during infancy. We described a 69-year-old man with generalized tonic-clonic seizures who was diagnosed with an intracranial mass. Multidetector computed tomography, magnetic resonance imaging and digital subtraction angiography studies were performed for evaluation of brain, and there was a well-enhancing mass found in the right temporal lobe without a definite feeding vessel. The patient underwent surgery and the pathologic examination demonstrated marked proliferation of small vessels with a lobular pattern in the brain parenchyma, which was confirmed to be capillary hemangioma.

  3. Microfluidic chip-capillary electrophoresis devices

    CERN Document Server

    Fung, Ying Sing; Du, Fuying; Guo, Wenpeng; Ma, Tongmei; Nie, Zhou; Sun, Hui; Wu, Ruige; Zhao, Wenfeng

    2015-01-01

    Capillary electrophoresis (CE) and microfluidic chip (MC) devices are relatively mature technologies, but this book demonstrates how they can be integrated into a single, revolutionary device that can provide on-site analysis of samples when laboratory services are unavailable. By introducing the combination of CE and MC technology, Microfluidic Chip-Capillary Electrophoresis Devices broadens the scope of chemical analysis, particularly in the biomedical, food, and environmental sciences.The book gives an overview of the development of MC and CE technology as well as technology that now allows

  4. TESTICULAR CAPILLARY HEMANGIOMA: DESCRIPTION OF A CASE

    Directory of Open Access Journals (Sweden)

    A. S. Markova

    2014-07-01

    Full Text Available The paper describes a clinical case of testicular capillary hemangioma in a 24-year-old man undergone a partial resection of the testis with the intraoperative morphological examination. Testicular capillary hemangioma is a rare benign tumor of a vascular origin, which can be similar to malignant testicular tumors on the clinical presentation, as well as on the imaging methods, in particular to seminoma. The intraoperative histological study can assist in avoiding organ-removing surgical interventions in diagnostically ambiguous cases if a benign testicular tumor is diagnosed.

  5. A direct method for determining complete positive and negative capillary pressure curves for reservoir rock using the centrifuge

    Energy Technology Data Exchange (ETDEWEB)

    Spinler, E.A.; Baldwin, B.A. [Phillips Petroleum Co., Bartlesville, OK (United States)

    1997-08-01

    A method is being developed for direct experimental determination of capillary pressure curves from saturation distributions produced during centrifuging fluids in a rock plug. A free water level is positioned along the length of the plugs to enable simultaneous determination of both positive and negative capillary pressures. Octadecane as the oil phase is solidified by temperature reduction while centrifuging to prevent fluid redistribution upon removal from the centrifuge. The water saturation is then measured via magnetic resonance imaging. The saturation profile within the plug and the calculation of pressures for each point of the saturation profile allows for a complete capillary pressure curve to be determined from one experiment. Centrifuging under oil with a free water level into a 100 percent water saturated plug results in the development of a primary drainage capillary pressure curve. Centrifuging similarly at an initial water saturation in the plug results in the development of an imbibition capillary pressure curve. Examples of these measurements are presented for Berea sandstone and chalk rocks.

  6. Quantification of nucleotides by ICPMS: coupling of ICPMS with capillary electrophoresis or capillary HPLC

    International Nuclear Information System (INIS)

    Full text: Quantification of nucleotides in small volumes of biological samples has eagerly been demanded. A method using ICPMS coupled with capillary electrophoresis or capillary liquid chromatography is reported. A new interface system, which consists of a double tube nebulizer inserted with a fused silica capillary tube and a cylinder mini-chamber with a sheath gas inlet, was designed. Moreover, the surface conditions of the sampling and skimmer cones, and the introduction of H2 gas into the plasma were found to significantly improve the signal/background ratio for phosphorus determination at m/z 31. (author)

  7. Groundwater recharge and capillary rise in a clayey catchment: modulation by topography and the Arctic Oscillation

    Directory of Open Access Journals (Sweden)

    T. M. Schrøder

    2004-01-01

    Full Text Available The signature left by capillary rise in the water balance is investigated for a 16 km2 clayey till catchment in Denmark. Integrated modelling for 1981–99 substantiates a 30% uphill increase in average net recharge, caused by the reduction in capillary rise when the water table declines. Calibration of the groundwater module is constrained by stream flow separation and water table wells. Net recharge and a priori parameterisation has been estimated from those same data, an automatic rain gauge and electrical sounding. Evaluation of snow storage and compensation for a simplified formulation of unsaturated hydraulic conductivity contribute to a modelling of the precipitation-runoff relation that compares well with measurements in other underdrained clayey catchments. The capillary rise is assumed to be responsible for a 30% correlation between annual evapotranspiration and the North Atlantic Oscillation. The observed correlation, and the hypothesis of a hemispherical Arctic Oscillation linking atmospheric pressure with surface temperature, suggests that modelled evapotranspiration from clayey areas is better than precipitation records for identifying the region influenced by oscillation. Keywords: catchment modelling, MIKE SHE, capillary rise, degree-day model, climate

  8. Viscosity measurement in the capillary tube viscometer under unsteady flow

    International Nuclear Information System (INIS)

    The objective of the present study is to develop a new device that the viscous characteristics of fluids are determined by applying the unsteady flow concept to the traditional capillary tube viscometer. The capillary tube viscometer consists of a small cylindrical reservoir, capillary tube, a load cell system that measures the mass flow rate, interfaces, and computer. Due to the small size of the reservoir the height of liquid in the reservoir decreases as soon as the liquid in the reservoir drains out through the capillary and the mass flow rate in the capillary decreases as the hydrostatic pressure in the reservoir decreases resulting in a decrease of the shear rate in the capillary tube. The instantaneous shear rate and driving force in the capillary tube are determined by measuring the mass flow rate through the capillary, and the fluid viscosity is determined from the measured flow rate and the driving force

  9. A Rare Association of Trigeminal Autonomic Cephalgia: Pontine Capillary Telangiectasia

    OpenAIRE

    Gocmen, Rahsan; Kurt, Erdal; Arslan, Sabina; Unal-Cevik, Isin; Karli Oguz, Kader; Tezer, F Irsel

    2015-01-01

    This report describes a case of pontine capillary telangiectasia in a 43-year-old woman with a clinical diagnosis of trigeminal autonomic cephalgia. The possible association with pontine capillary telangiectasia and trigeminal autonomic cephalgia is discussed.

  10. Physico-chemical characterization of liposomes and drug substance-liposome interactions in pharmaceutics using capillary electrophoresis and electrokinetic chromatography

    DEFF Research Database (Denmark)

    Franzen, Ulrik; Østergaard, Jesper

    2012-01-01

    electrophoresis and liposome electrokinetic chromatography for the characterization of liposomes in a pharmaceutical context. Capillary electrophoretic techniques have been used for the measurement of electrophoretic mobility, which provides information on liposome surface charge, size and membrane permeability...... of liposomes. The use of liposome electrokinetic chromatography and capillary electrophoresis for determination of liposome/water partitioning and characterization of drug-liposome interactions is reviewed. A number of studies indicate that capillary electrophoresis may have a role in the...... characterization of liposome drug delivery systems, e.g., for the investigation of encapsulation efficiency and drug leakage. The well-known characteristics of capillary electrophoresis, i.e., low sample volume requirement, high separation efficiency in aqueous media without a stationary phase, minimal sample...

  11. Modelling capillary trapping using finite-volume simulation of two-phase flow directly on micro-CT images

    Science.gov (United States)

    Raeini, Ali Q.; Bijeljic, Branko; Blunt, Martin J.

    2015-09-01

    We study capillary trapping in porous media using direct pore-scale simulation of two-phase flow on micro-CT images of a Berea sandstone and a sandpack. The trapped non-wetting phase saturations are predicted by solving the full Navier-Stokes equations using a volume-of-fluid based finite-volume framework to simulate primary drainage followed by water injection. Using these simulations, we analyse the effects of initial non-wetting-phase saturation, capillary number and flow direction on the residual saturation. The predictions from our numerical method are in agreement with published experimental measurements of capillary trapping curves. This shows that our direct simulation method can be used to elucidate the effect of pore structure and flow pattern of capillary trapping and provides a platform to study the physics of multiphase flow at the pore scale.

  12. Numerical and experimental study of capillary-driven flow of PCR solution in hybrid hydrophobic microfluidic networks.

    Science.gov (United States)

    Ramalingam, Naveen; Warkiani, Majid Ebrahimi; Ramalingam, Neevan; Keshavarzi, Gholamreza; Hao-Bing, Liu; Hai-Qing, Thomas Gong

    2016-08-01

    Capillary-driven microfluidics is essential for development of point-of-care diagnostic micro-devices. Polymerase chain reaction (PCR)-based micro-devices are widely developed and used in such point-of-care settings. It is imperative to characterize the fluid parameters of PCR solution for designing efficient capillary-driven microfluidic networks. Generally, for numeric modelling, the fluid parameters of PCR solution are approximated to that of water. This procedure leads to inaccurate results, which are discrepant to experimental data. This paper describes mathematical modeling and experimental validation of capillary-driven flow inside Poly-(dimethyl) siloxane (PDMS)-glass hybrid micro-channels. Using experimentally measured PCR fluid parameters, the capillary meniscus displacement in PDMS-glass microfluidic ladder network is simulated using computational fluid dynamic (CFD), and experimentally verified to match with the simulated data. PMID:27432321

  13. Water

    Science.gov (United States)

    ... www.girlshealth.gov/ Home Nutrition Nutrition basics Water Water Did you know that water makes up more ... to drink more water Other drinks How much water do you need? top Water is very important, ...

  14. Application of CHESS single-bounce capillaries at synchrotron beamlines

    Science.gov (United States)

    Huang, R.; Szebenyi, T.; Pfeifer, M.; Woll, A.; Smilgies, D.-M.; Finkelstein, K.; Dale, D.; Wang, Y.; Vila-Comamala, J.; Gillilan, R.; Cook, M.; Bilderback, D. H.

    2014-03-01

    Single-bounce capillaries are achromatic X-ray focusing optics that can provide efficient and high demagnification focusing with large numerical apertures. Capillary fabrication at CHESS can be customized according to specific application requirements. Exemplary applications are reviewed in this paper, as well as recent progress on condensers for high-resolution transmission X-ray microscopy and small focal size capillaries.

  15. Direct determination of contact angles of model soils in comparison with wettability characterization by capillary rise

    Science.gov (United States)

    Ramírez-Flores, Juan Carlos; Bachmann, Jörg; Marmur, Abraham

    2010-03-01

    SummaryAn accurate method to determine contact angles (CA) of soils as a measure of water repellency is still missing. In the present research, we evaluated and compared different methods to determine the CA of dry soil samples. Experiments were made by using a set of porous materials (silt, sand and glass beads) with different levels of water repellency. The CAs were measured with the Capillary Rise Method ( θCRM; liquid penetration into a 3-d system), the Wilhelmy plate method ( θWPM; measurement of capillary forces acting on a plane sample) and the Sessile Drop Method ( θSDM; optical CA analysis of drop contour on a plane sample). Results were compared with the CAs calculated from capillary rise in long vertical columns ( θECR), where liquid profiles of the final capillary rise of water and ethanol, respectively, were used to derive the contact angle under the assumed equilibrium conditions. The results showed the overestimation of the CA by using the well established bi-liquid CRM technique for porous materials, in particular for material with a low degree of water repellency (CA < 40°) and for the finer textured materials. In contrast, a variant of the Wilhelmy plate method, i.e. the cosine-averaged advancing CA and receding CA ( θEWPM), as well as the Sessile Drop CA, θSDM, were close to the ones of θECR. We concluded that θEWPM and θSDM are apparent CA, but nevertheless able to predict the impact of wettability on the final capillary rise which is affected by pore topology as well as by wettability.

  16. Modeling of Throttling Process inside Capillary Tube

    Czech Academy of Sciences Publication Activity Database

    Vinš, Václav; Vacek, V.

    Praha : ČVUT, 2009, s. 250-251. ISBN 978-80-01-04286-1. [ANNUAL CTU UNIVERSITY-WIDE SEMINAR /18./. Praha (CZ), 16.02.2009-20.02.2009] Institutional research plan: CEZ:AV0Z20760514 Keywords : capillary tube * numerical model * metastable flow Subject RIV: BJ - Thermodynamics https://workshop.cvut.cz/2009/

  17. Planetary In Situ Capillary Electrophoresis System (PISCES)

    Science.gov (United States)

    Willis, P. A.; Stockton, A. M.; Mora, M. F.; Cable, M. L.; Bramall, N. E.; Jensen, E. C.; Jiao, H.; Lynch, E.; Mathies, R. A.

    2012-10-01

    We propose to develop PISCES, a 3-kg, 2W, flight-capable microfluidic lab-on-a-chip capillary electrophoresis analyzer capable of ingesting solid, liquid, or gas samples and performing a suite of chemical analyses with parts per trillion sensitivity.

  18. Imbibition of ``Open Capillary'': Fundamentals and Applications

    Science.gov (United States)

    Tani, Marie; Kawano, Ryuji; Kamiya, Koki; Okumura, Ko

    2015-11-01

    Control or transportation of small amount of liquid is one of the most important issues in various contexts including medical sciences or pharmaceutical industries to fuel delivery. We studied imbibition of ``open capillary'' both experimentally and theoretically, and found simple scaling laws for both statics and dynamics of the imbibition, similarly as that of imbibition of capillary tubes. Furthermore, we revealed the existence of ``precursor film,'' which developed ahead of the imbibing front, and the dynamics of it is described well by another scaling law for capillary rise in a corner. Then, to show capabilities of open capillaries, we demonstrated two experiments by fabricating micro mixing devices to achieve (1) simultaneous multi-color change of the Bromothymol blue (BTB) solution and (2) expression of the green florescent protein (GFP). This research was partly supported by ImPACT Program of Council for Science, Technology and Innovation (Cabinet Office, Government of Japan). M. T. is supported by the Japan Society for the Promotion of Science Research Fellowships for Young Scientists.

  19. Analytical biotechnology: Capillary electrophoresis and chromatography

    International Nuclear Information System (INIS)

    The papers describe the separation, characterization, and equipment required for the electrophoresis or chromatography of cyclic nucleotides, pharmaceuticals, therapeutic proteins, recombinant DNA products, pheromones, peptides, and other biological materials. One paper, On-column radioisotope detection for capillary electrophoresis, has been indexed separately for inclusion on the data base

  20. Macroscopic theory for capillary-pressure hysteresis.

    Science.gov (United States)

    Athukorallage, Bhagya; Aulisa, Eugenio; Iyer, Ram; Zhang, Larry

    2015-03-01

    In this article, we present a theory of macroscopic contact angle hysteresis by considering the minimization of the Helmholtz free energy of a solid-liquid-gas system over a convex set, subject to a constant volume constraint. The liquid and solid surfaces in contact are assumed to adhere weakly to each other, causing the interfacial energy to be set-valued. A simple calculus of variations argument for the minimization of the Helmholtz energy leads to the Young-Laplace equation for the drop surface in contact with the gas and a variational inequality that yields contact angle hysteresis for advancing/receding flow. We also show that the Young-Laplace equation with a Dirichlet boundary condition together with the variational inequality yields a basic hysteresis operator that describes the relationship between capillary pressure and volume. We validate the theory using results from the experiment for a sessile macroscopic drop. Although the capillary effect is a complex phenomenon even for a droplet as various points along the contact line might be pinned, the capillary pressure and volume of the drop are scalar variables that encapsulate the global quasistatic energy information for the entire droplet. Studying the capillary pressure versus volume relationship greatly simplifies the understanding and modeling of the phenomenon just as scalar magnetic hysteresis graphs greatly aided the modeling of devices with magnetic materials. PMID:25646688

  1. Capillary zone electrophoresis and capillary isotachophoresis applied to physicochemical characterization of oligo- and polypeptides

    Czech Academy of Sciences Publication Activity Database

    Kašička, Václav; Šolínová, Veronika; Tůmová, Tereza; Koval, Dušan; Ibrahim, A.; Chamieh, J.; Cottet, H.

    Helsinki: -, 2015. L4B. [International Symposium on Electro- and Liquid Phase-Separation Techniques (ITP2015) /22./ and Nordic Separation Science Symposium (NoSSS2015) /8./. 30.08.2015-03.09.2015, Helsinki] R&D Projects: GA ČR(CZ) GA13-17224S Institutional support: RVO:61388963 Keywords : capillary electrophoresis * capillary isotachophoresis * effective charge Subject RIV: CB - Analytical Chemistry, Separation

  2. Capillary isoelectric focusing of proteins and microorganisms in uncoated capillaries with UV and fluorimetric detection

    Czech Academy of Sciences Publication Activity Database

    Horká, Marie; Šlais, Karel; Růžička, F.; Holá, V.; Horký, J.

    Roma : Universita di Roma, 2004, P43. [ITP 2004. International Symposium on Capillary Electroseparation Techniques /14./. Roma (IT), 12.09.2004-15.09.2004] R&D Projects: GA AV ČR IAA4031302; GA AV ČR IBS4031201; GA ČR GA203/02/1447 Institutional research plan: CEZ:AV0Z4031919 Keywords : CIEF ioanalytes * uncoated capillaries Subject RIV: CB - Analytical Chemistry, Separation

  3. Effects of oleic acid on pulmonary capillary leak and thromboxanes

    International Nuclear Information System (INIS)

    The role of arachidonic acid metabolites in oleic acid-induced lung injury in anesthetized dogs was investigated. Oleic acid was administered as a bolus injection into the pulmonary artery after either indomethacin (10 mg/kg iv) or vehicle. Measurements of hemodynamic parameters, mean systemic (MAP), pulmonary capillary wedge, and pulmonary artery pressures (PAP), cardiac output, arterial blood gases, extravascular lung waters (EVLW) by thermaldye double indicator dilution techniques and plasma immunoreactive thromboxane B2 (iTxB2), by radioimmunoassay were obtained at zero time (baseline) and 20 min following each oleic acid injection. A new noninvasive technique was employed to measure pulmonary capillary protein leak by the scintigraphic analysis of intravenously administered technetium-99m radiolabeled human serum albumin (99mTc -HSA) in the cardiac and lung regions. Oleic acid injection caused a significant dose related fall in MAP, arterial pO2, and cardiac output, and increases in EVLW and plasma iTxB2 in the vehicle pretreated animals, while mean PAP remained unchanged. In contrast, in the indomethacin pretreated dogs, MAP, EVLW, cardiac output, and plasma iTxB2 levels did not change from baseline values and there was an increase in mean PAP. Pulmonary vascular resistance was significantly elevated in both groups

  4. Numerical Simulation of Microbiological Growth in the Capillary Fringe

    Science.gov (United States)

    Hron, P.; Jost, D.; Engwer, C.; Ippisch, O.; Bastian, P.

    2012-04-01

    The capillary fringe (CF) is a highly dynamic zone in a porous media at the interface between water-saturated aquifer and vadose zone, where steep biogeochemical gradients and thus high bioactivities are expected. In recent years, considerable effort has been undertaken to deepen the understanding of the physical (flow, diffusion, dispersion), geochemical (dissolution, precipitation) and biological (metabolism, excretion, biofilm formation) processes in the CF. We developed a numerical simulator for multiphase multicomponent flow in porous media which is able to consider simultaneously multiphase flow, component transport, phase exchange, geochemical reactions and microbiological processes. A splitting approach for phase transport, component transport and reaction/phase exchanges allows the usage of higher-order discretizations for the component transport. This reduces numerical dispersion significantly, which is especially important in the simulation of reactive flow. In a flow-through laboratory experiment performed at the Karlsruhe Institute of Technology, Germany, within the project "Dynamic Capillary Fringes - A Multidisciplinary Approach", the oxygen phase transfer, the growth and the transport of a bacteria (green fluorescent Escherichia coli) were investigated. The results of numerical simulations of the E. coli growth in the CF with a high nutrient supply under steady-state and transient flow conditions are compared to the experimental data.

  5. Viscosity measurement of alkali chlorides with capillary viscometer

    International Nuclear Information System (INIS)

    Viscosities of molten alkali chlorides have been measured by means of newly designed capillary viscometer made of fused quartz as shown in Fig. 1 and combined with a special transparent electric furnace which can be inverted. The viscometer was of a suspended level type and designed so as to minimize the error associated with the measurement, e.g., the effect of surface tension. Reynolds number of the capillary was less than 100. The sample was introduced into the viscometer through the quartz filter and then sealed under vacuum. Cell constants of the viscometer were determined by using distilled water as a calibration liquid. Efflux times were measured by direct visual observation using a digital stopwatch, and showed excellent reproducibility. The viscometer in the present investigation proved to be very precise and the errors accompanied were considered to be less than 0.7%. Viscosities obtained are collected in Table 1 and Figs. 3-1 -- 3-5 together with the previous data. Whereas the viscosity did not necessarily show any regularity, the activation energy for viscous flow increased with increasing cation size in the series of molten alkali chlorides. On the basis of a hard sphere model, the sizes of the flow units were considered to be nearly equal to those of cation-anion pairs. The viscosity of each molten alkali chloride at melting temperature increased with an increasing ratio of the flow unit volume to the hole volume. (author)

  6. Influence of capillary bridge formation onto the silica nanoparticle interaction studied by grand canonical Monte Carlo simulations.

    Science.gov (United States)

    Leroch, Sabine; Wendland, Martin

    2013-10-01

    Adhesion forces between nanoparticles strongly depend on the amount of adsorbed condensed water from ambient atmosphere. Liquid water forms bridges in the cavities separating the particles, giving rise to the so-called capillary forces which in most cases dominate the van der Waals and long-range electrostatic interactions. Capillary forces promote the undesirable agglomeration of particles to large clusters, thereby hindering the flowability of dry powders in process containers. In process engineering macroscopic theories based on the Laplace pressures are used to estimate the strength of the capillary forces. However, especially for low relative humidity and when the wetting of rough or small nanoparticles is studied, those theories can fail. Molecular dynamic simulations can help to give better insight into the water-particle interface. The simulated force versus distance curve as well as adhesion forces and the adsorption isotherm for silica nanoparticles at varying relative humidity will be discussed in comparison to experiments, theories, and simulations. PMID:24015790

  7. 静态顶空毛细管柱气相色谱法测定生活饮用水中三氯甲烷和四氯化碳%Determination on Trichloromethane and Carbon tetrachloride in Drinking Water by Static Headspace Capillary Gas Chromatography

    Institute of Scientific and Technical Information of China (English)

    纪增香

    2012-01-01

    建立了静态顶空毛细管柱气相色谱法测定生活饮用水中三氯甲烷和四氯化碳的方法。实验结果显示:三氯甲烷和四氯化碳在其测定范围内线性关系良好,相关系数为0.998~0.997,回收率为89.0%~107.0%。该方法简便、快速、可行。%To establish a static headspace capillary gas chromatography method for the determination of trichloromethane and carbon tetrachloride in drinking water.The results showed that the trichloromehane and carbon tetrachloride in the scope had a good linear relationship,the correlation coefficient were all 0.998~0.997,the recovery rate were 89%~107%.The method is simple,rapid and feasible.

  8. Automated dual capillary electrophoresis system with hydrodynamic injection for the concurrent determination of cations and anions

    International Nuclear Information System (INIS)

    Highlights: • Concurrent determination of cations and anions was carried out by electrophoretic separation. • Optimized conditions for each class of analystes was possible by using separate capillaries. • Simultaneous hydrodynamic injection was carried out. • Pneumatic actuation was used for flushing and sample handling. • The denitrification of drinking water was successfully demonstrated. - Abstract: The capillary electrophoresis instrument developed for the concurrent determination of cations and anions features two separate capillaries and individual detectors to allow independent optimization for each group of ions. The capillaries are joined in a common injector block. The sample is drawn into the injector with a small membrane pump and automated simultaneous injection into both capillaries is achieved by pressurization of the fluid with compressed air. Flushing of the injector and of the capillaries with the background electrolyte is also carried out automatically by the same means. The buffer consisted of 12 mM histidine and 2 mM 18-crown-6 adjusted to pH 4 with acetic acid and was suitable for the contactless conductivity detection employed. The system was optimized for the determination of cationic NH4+ and anionic NO3− and NO2−, and linear calibration curves from about 20 μM up to about 1.5 mM were obtained for these ions. In a test run over 8 h, the reproducibility for the peak areas was within ±7%. For demonstration, the instrument was successfully applied to the concurrent monitoring of the concentrations of the three ions during the biological removal of ammonium from contaminated groundwater in a sequencing batch reactor, where NO3− and NO2− are formed as intermediate products

  9. Automated dual capillary electrophoresis system with hydrodynamic injection for the concurrent determination of cations and anions

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Thi Thanh Thuy; Mai, Thanh Duc [University of Basel, Department of Chemistry, Spitalstrasse 51, Basel 4056 (Switzerland); Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Nguyen Trai Street 334, Hanoi (Viet Nam); Nguyen, Thanh Dam [Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Nguyen Trai Street 334, Hanoi (Viet Nam); Sáiz, Jorge [Department of Analytical Chemistry, Physical Chemistry and Chemical Engineering – University of Alcalá, Ctra. Madrid-Barcelona km 33.6, Alcalá de Henares, Madrid 28871 (Spain); Pham, Hung Viet, E-mail: phamhungviet@hus.edu.vn [Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Nguyen Trai Street 334, Hanoi (Viet Nam); Hauser, Peter C., E-mail: Peter.Hauser@unibas.ch [University of Basel, Department of Chemistry, Spitalstrasse 51, Basel 4056 (Switzerland)

    2014-09-02

    Highlights: • Concurrent determination of cations and anions was carried out by electrophoretic separation. • Optimized conditions for each class of analystes was possible by using separate capillaries. • Simultaneous hydrodynamic injection was carried out. • Pneumatic actuation was used for flushing and sample handling. • The denitrification of drinking water was successfully demonstrated. - Abstract: The capillary electrophoresis instrument developed for the concurrent determination of cations and anions features two separate capillaries and individual detectors to allow independent optimization for each group of ions. The capillaries are joined in a common injector block. The sample is drawn into the injector with a small membrane pump and automated simultaneous injection into both capillaries is achieved by pressurization of the fluid with compressed air. Flushing of the injector and of the capillaries with the background electrolyte is also carried out automatically by the same means. The buffer consisted of 12 mM histidine and 2 mM 18-crown-6 adjusted to pH 4 with acetic acid and was suitable for the contactless conductivity detection employed. The system was optimized for the determination of cationic NH{sub 4}{sup +} and anionic NO{sub 3}{sup −} and NO{sub 2}{sup −}, and linear calibration curves from about 20 μM up to about 1.5 mM were obtained for these ions. In a test run over 8 h, the reproducibility for the peak areas was within ±7%. For demonstration, the instrument was successfully applied to the concurrent monitoring of the concentrations of the three ions during the biological removal of ammonium from contaminated groundwater in a sequencing batch reactor, where NO{sub 3}{sup −} and NO{sub 2}{sup −} are formed as intermediate products.

  10. Capillary Interactions between a Probe Tip and a Nanoparticle

    Institute of Scientific and Technical Information of China (English)

    SUN Li-Ning; WANG Le-Feng; RONG Wei-Bin

    2008-01-01

    To understand capillary interactions between probe tips and nanoparticles under ambient conditions,a theoretical model of capillary forces between them is developed based on the geometric relations. It is found that the contribution of surface tension force to the total capillary force attains to similar order of magnitude as the capillary pressure force in many cases.It is also shown that the tip shape and the radial distance of the meniscus have great influence on the capillary force.The capillary force decreases with the increasing separation distances,and the variance of the contact angles may change the magnitudes of capillary forces several times at large radial distances.The applicability of the symmetric meniscus approximation is discussed.

  11. Capillary Penetration into Inclined Circular Glass Tubes.

    Science.gov (United States)

    Trabi, Christophe L; Ouali, F Fouzia; McHale, Glen; Javed, Haadi; Morris, Robert H; Newton, Michael I

    2016-02-01

    The spontaneous penetration of a wetting liquid into a vertical tube against the force of gravity and the imbibition of the same liquid into a horizontal tube (or channel) are both driven by capillary forces and described by the same fundamental equations. However, there have been few experimental studies of the transition from one orientation to the other. We report systematic measurements of capillary penetration of polydimethylsiloxane oils of viscosities 9.6, 19.2, and 48.0 mPa·s into glass capillary tubes. We first report the effect of tube radii R between 140 and 675 μm on the dynamics of spontaneous imbibition. We show that the data can be fitted using the exact numerical solution to the governing equations and that these are similar to fits using the analytical viscogravitational approximation. However, larger diameter tubes show a rate of penetration slower than expected using an equilibrium contact angle and the known value of liquid viscosity. To account for the slowness, an increase in viscosity by a factor (η/ρ)scaling is needed. We show full agreement with theory requires the ratio R/κ(-1) ∼ 0.1 or less, where κ(-1) is the capillary length. In addition, we propose an experimental method that enables the determination of the dynamic contact angle during imbibition, which gives values that agree with the literature values. We then report measurements of dynamic penetration into the tubes of R = 190 and 650 μm for a range of inclination angles to the horizontal, φ, from 5 to 90°. We show that capillary penetration can still be fitted using the viscogravitational solution, rather than the Bosanquet solution which describes imbibition without gravity, even for inclination angles as low as 10°. Moreover, at these low angles, the effect of the tube radius is found to diminish and this appears to relate to an effective capillary length, κ(-1)(φ) = (γLV/ρg sin φ)(1/2). PMID:26738739

  12. Four degree of freedom liquid dispenser for direct write capillary self-assembly with sub-nanoliter precision

    Science.gov (United States)

    Beroz, Justin; Bedewy, Mostafa; Reinker, Michael; Chhajer, Vipul; Awtar, Shorya; Hart, A. John

    2012-01-01

    Capillary forces provide a ubiquitous means of organizing micro- and nanoscale structures on substrates. In order to investigate the mechanism of capillary self-assembly and to fabricate complex ordered structures, precise control of the meniscus shape is needed. We present a precision instrument that enables deposition of liquid droplets spanning from 2 nl to 300 μl, in concert with mechanical manipulation of the liquid-substrate interface with four degrees of freedom. The substrate has sub-100 nm positioning resolution in three axes of translation, and its temperature is controlled using thermoelectric modules. The capillary tip can rotate about the vertical axis while simultaneously dispensing liquid onto the substrate. Liquid is displaced using a custom bidirectional diaphragm pump, in which an elastic membrane is hydraulically actuated by a stainless steel syringe. The syringe is driven by a piezoelectric actuator, enabling nanoliter volume and rate control. A quantitative model of the liquid dispenser is verified experimentally, and suggests that compressibility in the hydraulic line deamplifies the syringe stroke, enabling sub-nanoliter resolution control of liquid displacement at the capillary tip. We use this system to contact-print water and oil droplets by mechanical manipulation of a liquid bridge between the capillary and the substrate. Finally, we study the effect of droplet volume and substrate temperature on the evaporative self-assembly of monodisperse polymer microspheres from sessile droplets, and demonstrate the formation of 3D chiral assemblies of micro-rods by rotation of the capillary tip during evaporative assembly.

  13. A novel covalent coating of capillaries for capillary electrophoresis coupled to matrix assisted laser desorption ionization

    International Nuclear Information System (INIS)

    Capillary electrophoresis (CE) offers the advantage of flexibility and method development. It excels in the area of separation of ions, chiral, polar, and biological compounds (especially proteins and peptides). Masking the active sites on the inner surface of a bare fused-silica capillary wall is often necessary for CE separations of basic compounds, proteins and peptides. The use of capillary surface coatings is an approach to prevent adsorption phenomena and improve the repeatability of these analytes. In this work, new capillary coatings consisting of (I) derivatized polystyrene nanoparticles (PS) and (II) derivatized fullerenes, were investigated for the analysis of peptides and protein digest by CE. The coated capillaries showed excellent run-to-run and batch-to-batch reproducibility (RSD of migration time ≤ 0.5 % for run to run and ≤ 9.5 % for batch-to-batch experiments). Furthermore, the capillaries offer high stability from pH 2.0 up to pH 10.0. The actual potential of the coated capillaries was tested by combining CE with matrix-assisted laser desorption ionisation (MALDI) mass spectrometry (MS) for analysing complex samples, such as peptides, whereas the overall performance of the CE-MALDI-TOF-MS system was investigated by analysing a five protein digest mixture. Subsequently, the peak list (peptide mass fingerprint) generated from the mass spectra of each fraction was entered into the Swiss Prot database in order to search for matching tryptic fragments using the Mascot software. The sequence coverage of analysed proteins was between 36-68%. The established technology benefits from the synergism of high separation efficiency and the structure selective identification via MS. (author)

  14. a Comprehensive Model for Capillary Pressure Difference across a Drop/bubble Flowing Through a Constricted Capillary

    Science.gov (United States)

    Liang, Mingchao; Wei, Junhong; Han, Hongmei; Fu, Chengguo; Liu, Jianjun

    2015-09-01

    The capillary pressure is one of the crucial parameters in many science and engineering applications such as composite materials, interface science, chemical engineering, oil exploration, etc. The drop/bubble formation and its mechanisms that affect the permeability of porous media have steadily attracted much attention in the past. When a drop/bubble moves from a larger capillary to a smaller one, it is often obstructed by an additional pressure difference caused by the capillary force. In this paper, a comprehensive model is derived for the capillary pressure difference when a drop/bubble flows through a constricted capillary, i.e. a geometrically constricted passage with an abrupt change in radius. The proposed model is expressed as a function of the smaller capillary radius, pore-throat ratio, contact angle, surface tension and length of the drop/bubble in the smaller capillary. The model predictions are compared with the available experimental data, and good agreement is found between them.

  15. Capillary droplets on Leidenfrost micro-ratchets

    CERN Document Server

    Marin, Alvaro G; Römer, Gertwillem R B E; Pathiraj, B; Veld, Albertus Huis in 't; Lohse, Detlef

    2012-01-01

    Leidenfrost ratchets are structures with the ability of transporting liquid droplets when heated over the critical Leidenfrost temperature. Once this temperature is reached, the droplet levitates over the surface and moves in the direction marked by the slope of the ratchet at terminal velocities around 10 cm/s. Here we provide new experiments with micron-sized ratchets, which have been produced with picosecond pulse laser ablation. In the following work, we use a simple method to measure the thrust driving droplets of capillary size over the micro-ratchets. The mechanism responsible for the force acting on the drop on superheated ratchets has been recently under debate. We extend the recently proposed 'viscous mechanism' proposed by Dupeaux et al. [Europhys. Lett., 96, 58001 (2011)] to capillary droplets and find good agreement with our measurements.

  16. Capillary flow through heat-pipe wicks

    Science.gov (United States)

    Eninger, J. E.

    1975-01-01

    Theoretical expressions are obtained for the capillary-pressure limit and permeability of a fibrous wick in terms of the porosity and fiber diameter. Hysteresis in capillary pressure is included through the introduction of an empirical hysteresis constant. A partial-saturation model based on the statistical distribution of local porosity requires an additional empirical constant, the standard deviation. The theory is compared to results of a beta-ray absorption experiment that measured the liquid content of a partially saturated wick and to results of permeability measurements on partially and fully saturated wicks. A simple wick-weighing experiment is described that yields values for the empirical hysteresis constant and the standard deviation. Theoretical results are used to design an optimum wick.

  17. Capillary Hemangioma of the Fallopian Tube.

    Science.gov (United States)

    Katiyar, Richa; Patne, Shashikant C U; Bharti, Shreekant; Jain, Madhu

    2016-04-01

    Neoplastic lesions of the fallopian tube are rarely seen by surgical pathologists. Haemangioma of the fallopian tube is an extremely rare benign neoplasm. A 30-year-old lady with polymenorrhea and dysmenorrhea underwent hysterectomy and bilateral salpingo-oophorectomy. Her left fallopian tube showed a 2mm sized solid nodule in the wall. Histopathological examination revealed a well-defined vascular lesion in the left fallopian tube, consistent with capillary haemangioma. The vascular endothelium was highlighted by CD34 immunostaining. Our literature review has identified 10 cases of cavernous haemangioma of the fallopian tube. To the best of our knowledge, we report the first ever case of capillary haemangioma of the fallopian tube. This is also the smallest detected haemangioma in the fallopian tube. PMID:27190899

  18. Chemical Power for Microscopic Robots in Capillaries

    CERN Document Server

    Hogg, Tad

    2009-01-01

    The power available to microscopic robots (nanorobots) that oxidize bloodstream glucose while aggregated in circumferential rings on capillary walls is evaluated with a numerical model using axial symmetry and time-averaged release of oxygen from passing red blood cells. Robots about one micron in size can produce up to several tens of picowatts, in steady-state, if they fully use oxygen reaching their surface from the blood plasma. Robots with pumps and tanks for onboard oxygen storage could collect oxygen to support burst power demands two to three orders of magnitude larger. We evaluate effects of oxygen depletion and local heating on surrounding tissue. These results give the power constraints when robots rely entirely on ambient available oxygen and identify aspects of the robot design significantly affecting available power. More generally, our numerical model provides an approach to evaluating robot design choices for nanomedicine treatments in and near capillaries.

  19. The geometry and wetting of capillary folding

    CERN Document Server

    Péraud, Jean-Philippe

    2014-01-01

    Capillary forces are involved in a variety of natural phenomena, ranging from droplet breakup to the physics of clouds. The forces from surface tension can also be exploited in industrial application provided the length scales involved are small enough. Recent experimental investigations showed how to take advantage of capillarity to fold planar structures into three-dimensional configurations by selectively melting polymeric hinges joining otherwise rigid shapes. In this paper we use theoretical calculations to quantify the role of geometry and fluid wetting on the final folded state. Considering folding in two and three dimensions, studying both hydrophilic and hydrophobic situations with possible contact angle hysteresis, and addressing the shapes to be folded to be successively infinite, finite, curved, kinked, elastic, we are able to derive an overview of the geometrical parameter space available for capillary folding.

  20. EUV radiation from nitrogen capillary discharge

    Czech Academy of Sciences Publication Activity Database

    Frolov, Oleksandr; Koláček, Karel; Štraus, Jaroslav; Schmidt, Jiří

    Vol. 32. Singapore: World Scientific Publishing Co, 2014, "1460329-1 "-"1460329-7". ISSN 2010-1945. [International Conference on Plasma Science and Applications, ICPSA 2013. Singapore (SG), 04.12.2013-06.12.2013] R&D Projects: GA MŠk(CZ) LG13029 Institutional support: RVO:61389021 Keywords : EUV radiation * capillary discharge * EUV source * Z-pinch Subject RIV: BL - Plasma and Gas Discharge Physics http://www. world scientific.com/doi/abs/10.1142/S2010194514603299

  1. Electrical resistance of muscle capillary endothelium.

    OpenAIRE

    Olesen, S P; Crone, C

    1983-01-01

    A recently developed technique for in vivo determination of the electrical resistance of vascular endothelium in microvessels was applied to the vessels in a thin frog muscle, m. cutaneus pectoris. The technique consists of injection of current via a glass micropipette into a capillary and measurement of the resulting intra- and extravascular potential profiles with another micropipette placed at various distances from the current source. The theory of Peskoff and Eisenberg (1974) was used to...

  2. Identifying kinetically stable proteins with capillary electrophoresis

    OpenAIRE

    Zhang, Songjie; Xia, Ke; Chung, Wai Keen; Cramer, Steven M; Colón, Wilfredo

    2010-01-01

    Unlike most proteins, which are in equilibrium with partially and globally unfolded conformations, kinetically stable proteins (KSPs) are trapped in their native conformations and are often resistant to harsh environment. Based on a previous correlation between kinetic stability (KS) and a protein's resistance to sodium dodecyl sulfate (SDS), we show here a simple method to identify KSPs by SDS-capillary electrophoresis (CE). Control non-KSPs were fully denatured by SDS and formed protein:SDS...

  3. Separation of Peptides by Pressurized Capillary Electrochromatography

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A novel gradient pressurized capillary electrochromatography (pCEC) instrument wasdeveloped to separate peptides. Two gradient elution modes, hydrophobic and hydrophilicinteraction mode in pCEC, were performed on this instrument. Baseline separation of sixpeptides was obtained on two gradient modes with C18 column and strong cationic exchangecolumn respectively. The effects of mixer volume and total flow rate of pumps on resolutionwere also discussed.

  4. Familial Pulmonary Capillary Hemangiomatosis Early in Life

    OpenAIRE

    Speer, Christian P.; Mark, Eugene J.; Johannes Wirbelauer; Alexander Marx; Helge Hebestreit

    2011-01-01

    Background. Pulmonary capillary hemangiomatosis (PCH) is a rare disease, especially in infancy. Four infants have been reported up to the age of 12 months. So far, no familial patients are observed at this age. Patients. We report three siblings, two female newborns and a foetus of 15-week gestation of unrelated, healthy parents suffering from histologically proven PCH. The first girl presented with increased O2 requirements shortly after birth and patent ductus arteriosus (PDA). She subseque...

  5. Hydrophilic polymer systems in capillary electrophoretic separations

    Czech Academy of Sciences Publication Activity Database

    Guryča, Vilém; Novotný, M. V.; Michálek, Jiří; Pacáková, V.

    Praha : Charles University, Department of Chemistry, Albertov, 2005, s. 8-12. ISBN 80-903103-1-1. [International Student Conference ‘Modern Analytical Chemistry’/2./. Praha (CZ), 26.09.2005-27.09.2005] Grant ostatní: National Institute of General Medical Sciences, U.S. Department of Health and Human Services(US) GM24349 Institutional research plan: CEZ:AV0Z40500505 Keywords : analytical glycobiology * capillary electrochromatography * hydrophilic acrylamide monoliths Subject RIV: CD - Macromolecular Chemistry

  6. Highly conductive, printable pastes from capillary suspensions

    Science.gov (United States)

    Schneider, Monica; Koos, Erin; Willenbacher, Norbert

    2016-08-01

    We have used the capillary suspension phenomenon to design conductive pastes for printed electronic applications, such as front side metallization of solar cells, without non-volatile, organic additives that often deteriorate electrical properties. Adding a small amount of a second, immiscible fluid to a suspension creates a network of liquid bridges between the particles. This capillary force-controlled microstructure allows for tuning the flow behavior in a wide range. Yield stress and low-shear viscosity can be adjusted such that long-term stability is provided by inhibiting sedimentation, and, even more importantly, narrow line widths and high aspect ratios are accessible. These ternary mixtures, called capillary suspensions, exhibit a strong degree of shear thinning that allows for conventional coating or printing equipment to be used. Finally, the secondary fluid, beneficial for stability and processing of the wet paste, completely evaporates during drying and sintering. Thus, we obtained high purity silver and nickel layers with a conductivity two times greater than could be obtained with state-of-the-art, commercial materials. This revolutionary concept can be easily applied to other systems using inorganic or even organic conductive particles and represents a fundamental paradigm change to the formulation of pastes for printed electronics.

  7. Spatial reconstruction of facial skin capillaries

    Directory of Open Access Journals (Sweden)

    Makarchuk O.I.

    2010-01-01

    Full Text Available To define structural and functional changes of skin capillaries in women of different age groups in this work intraoperational biopsy material of skin of 205 women at the age from 19 to 75 years, that was taken during standard surgery instrumentations for different defects of face and neck skin correction, was investigated. Skin material of cheek face region, temple region of head and anterior neck region was morphologically processed. To define parameters of dermal capillars and spatial reconstruction of intrapapillary capillary loops, serial sections was investigated with the help of morphometry. It was determined, that microcirculation age changes include structural disorders of intrapapillary capillary loops. Essential struc-tural and functional changes observed in skin of cheek region in women of 33-40 years and in temple region of head and anterior neck region in women of 41-50 years. It is typical at the patients with nicotinic dependence, ischemic heart disease, hypertonic disease, a diabetes, and also adiposity of a different degree essential infringement of microvessels bed structure of a skin that gives the basis for allocation of the given contingent of patients as group high intraoperative and postoperative risk at carrying out of operative interventions for correction of face skin involutive changes.

  8. The order of condensation in capillary grooves.

    Science.gov (United States)

    Rascón, Carlos; Parry, Andrew O; Nürnberg, Robert; Pozzato, Alessandro; Tormen, Massimo; Bruschi, Lorenzo; Mistura, Giampaolo

    2013-05-15

    We consider capillary condensation in a deep groove of width L. The transition occurs at a pressure p(co)(L) described, for large widths, by the Kelvin equation p(sat) - p(co)(L) = 2σ cosθ/L, where θ is the contact angle at the side walls and σ is the surface tension. The order of the transition is determined by the contact angle of the capped end θcap; it is continuous if the liquid completely wets the cap, and first-order otherwise. When the transition is first-order, corner menisci at the bottom of the capillary lead to a pronounced metastability, determined by a complementary Kelvin equation Δp(L) = 2σ sinθcap/L. On approaching the wetting temperature of the capillary cap, the corner menisci merge and a single meniscus unbinds from the bottom of the groove. Finite-size scaling shifts, crossover behaviour and critical singularities are determined at mean-field level and beyond. Numerical and experimental results showing the continuous nature of condensation for θcap = 0 and the influence of corner menisci on adsorption isotherms are presented. PMID:23611878

  9. Capillary-scale polarimetry for flowing streams.

    Science.gov (United States)

    Swinney, K; Nodorft, J; Bornhop, D J

    2001-05-01

    A micro-polarimeter with a 40 nL probe volume was configured so that it is compatible with capillary-scale flowing stream analysis. The optical configuration consists of two polarizing optics, a capillary, a laser source and a photodetector which is very simple to configure with low cost components. This unique polarimeter is based upon the interaction of a linearly polarized laser beam and a capillary tube, in this case one with an inner diameter of 250 microns. Side illumination of the tube results in a 360 degrees fan of scattered light, which contains a set of interference fringes that change in response to optically active solutes. Solutes that exhibit optical activity are quantifiable and are detected by analyzing the polarization state of the backscattered light. The ability of the instrument to make extremely sensitive optical activity measurements in flowing streams is shown by the determination of (R)-mandelic acid, with a detection limit of 66 x 10(-6) M (507 x 10(-12) g), and the non-optically active control, glycerol. Additionally, the detector was configured to minimize refractive index perturbations. PMID:11394312

  10. Fabrication of a miniaturized capillary waveguide integrated fiber-optic sensor for fluoride determination.

    Science.gov (United States)

    Xiong, Yan; Wang, Chengjie; Tao, Tao; Duan, Ming; Tan, Jun; Wu, Jiayi; Wang, Dong

    2016-05-10

    Fluoride concentration is a key aspect of water quality and essential for human health. Too much or too little fluoride intake from water supplies is harmful to public health. In this study, a capillary waveguide integrated fiber-optic sensor was fabricated for fluoride measurement in water samples. The sensor was modularly designed with three parts, i.e., a light source, capillary flow cell and detector. When light propagated from a light emitting diode (LED) to the capillary waveguide cell through an excitation fiber, it interacted with the sensing reagent, and its intensity changed with different fluoride concentrations. Then, the light propagated to the detector through a detection fiber for absorption determination of fluoride according to Beer's law. This miniaturized sensor showed advantages of fast analysis (9.2 s) and small reagent demand (200 μL) per sample, and it also had a low detection limit (8 ppb) and high selectivity for fluoride determination. The sensor was applied to fluoride determination in different water samples. The results obtained were compared with those obtained by conventional spectrophotometry and ion chromatography, showing agreement and validating the sensor's potential application. PMID:27067512

  11. Elasto-capillary collapse of floating structures - Non-linear response of elastic structures under capillary forces

    CERN Document Server

    Adami, N; Roman, B; Bico, J; Caps, H

    2013-01-01

    Flexible rings and rectangle structures floating at the surface of water are prone to deflect under the action of surface pressure induced by the addition of surfactant molecules on the bath. While the frames of rectangles bend inward or outward for any surface pressure difference, circles are only deformed by compression beyond a critical buckling load. However, compressed frames also undergo a secondary buckling instability leading to a rhoboidal shape. Following the pioneering works of \\cite{Hu} and \\cite{Zell}, we describe both experimentally and theoretically the different elasto-capillary deflection and buckling modes as a function of the material parameters. In particular we show how this original fluid structure interaction may be used to probe the adsorption of surfactant molecules at liquid interfaces.

  12. Heatable sample holder for capillary experiments

    International Nuclear Information System (INIS)

    Complete text of publication follows. The transmission of charged particles through various types of capillaries has been recently in the center of interest. The observed ion guiding phenomenon offered new possibilities for fundamental investigations, characterization of the inner walls of the insulating tube and also holds various possible applications. Thereafter an intensive experimental investigation started to understand the basic properties of the guiding for ions using several insulating materials like PET, SiO2, and Al2O3. Another viewpoint of the experiments was how the guiding effect changes with the length or with the inner diameter of the capillary. Recently guiding of slow highly charged ions through a single glass macrocapillary has been studied, showing that guiding occurs even for macroscopic dimensions. As a completely new aspect we would like to measure the temperature dependence of the ion-guiding. The investigation of the temperature dependence of the guiding gives new possibilities both for a fundamental understanding of the guiding phenomenon and applications. The guiding maybe adjustable by changing the temperature of the capillary, namely it may improve the efficiency of the guiding power. In our future experiments we try to find the answer how the ion guiding ability of an insulating capillary changes as a function of temperature. For these experiments a completely new heatable sample holder was designed (see Fig. 1). Our preliminary results shows that the ion guiding ability of the capillary strongly decreases, when the temperature of the glass is raised from 20degC (room temperature) to 80degC. Acknowledgements The financial support received from the ITS-LEIF Project (RII3 026015) is gratefully acknowledged. This work was supported by the 'Stiftung Aktion Oesterreich-Ungarn', the grant 'Bolyai' from the Hungarian Academy of Sciences, the TeT Grant no. AT-7/2007, the Hungarian National Office for Research and Technology, as well as

  13. A covalent modified hydrophilic capillary for enhanced capillary electrophoresis of biopolymers

    Institute of Scientific and Technical Information of China (English)

    Lian Guo Shan; Xue Yu; Yin Mao Wei; Xiao Hui Zheng; Jian Bin Zheng

    2009-01-01

    δ-Gluconolactone was covalently coupled to aminopropyl derivatized capillary,which created hydrophilic brushes on the inner wall of the capillary.The coated capillary was shown to generate a stable electroosmotic flow(EOF)in the investigated pH range of 2.0-9.0 and to suppress effectively the adsorption of proteins.And it enabled separation of some biopolymer mixtures including basic proteins,DNA and tryptic digested bovine serum albumin(BSA)within 15 min with efficiencies up to 450,000 plates/m.The intra-and inter-day reproducibility of the coating referring to the retention times of proteins were satisfactory with mean relative standard deviations(R.S.D.)of 0.8 and 1.7%,respectively.

  14. An axial approach to detection in capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, J.A.

    1993-05-01

    Our approach involves on-axis illumination of the compounds inside the capillary detection region and is applied to absorbance and fluorescence detection. Absorbance measurements were made by focussing an incident laser beam into one capillary end; by using signals collected over the entire length of analyte band, this enhances the analytical path length of conventional absorbance detection 60x. This instrument offers a 15x improvement in detection limits. Three fluorescence detection experiments are discussed, all of which involve insertion of an optical fiber into capillary. The first uses a high refractive index liquid phase to obtain total internal reflectance along capillary axis, this reducing light scatter. The second uses a charge-coupled device camera for simultaneous imaging of a capillary array (this may be useful in genome sequencing, etc.). The third is a study of fluid motion inside the capillary under pressure-driven and electroosmotic flow. The thesis is divided into four parts. Figs, tabs.

  15. Slow Kinetics of Capillary Condensation in Confined Geometry: Experiment and Theory

    OpenAIRE

    Restagno, F.; Bocquet, L.; Crassous, J.; Charlaix, E.

    2001-01-01

    When two solid surfaces are brought in contact, water vapor present in the ambient air may condense in the region of the contact to form a liquid bridge connecting the two surfaces : this is the so-called capillary condensation. This phenomenon has drastic consequences on the contact between solids, modifying the macroscopic adhesion and friction properties. In this paper, we present a survey of the work we have performed both experimentally and theoretically to understand the microscopic fou...

  16. Determination of chlorophenols in environmental samples using electromembrane extraction and capillary electrophoresis

    OpenAIRE

    Šlampová, Andrea

    2013-01-01

    Combination of electromembrane extraction (EME) with capillary electrophoresis (CE) was used for determination of trace level chlorophenols (CPs) in environmental water samples. The analytes were transported across supported liquid membrane (SLM), composed of 1-ethyl-2-nitrobenzene (ENB), by the application of electrical field. A driving force of 150 V was applied to extract the analytes from neutral sample (donor solution) into strongly alkaline acceptor solutions. The acceptor soluti...

  17. Colloidal particle adsorption at liquid interfaces: Capillary driven dynamics and thermally activated kinetics

    OpenAIRE

    Rahmani, Amir M.; Wang, Anna; Manoharan, Vinothan N.; Colosqui, Carlos E.

    2016-01-01

    The adsorption of single colloidal microparticles (0.5--1 $\\mu$m radius) at a water-oil interface has been recently studied experimentally using digital holographic microscopy [Kaz \\textit{et al., Nat. Mater.}, 2012, \\textbf{11}, 138--142]. An initially fast adsorption dynamics driven by capillary forces is followed by an unexpectedly slow relaxation to equilibrium that is logarithmic in time and can span hours or days. The slow relaxation kinetics has been attributed to the presence of surfa...

  18. Further development of capillary electrophoresis for the quantitative determination of small inorganic anions

    OpenAIRE

    King, Marion

    2003-01-01

    Factors influencing the separation and indirect UV absorbance detection of common inorganic anions using capillary zone electrophoresis (CZE) have been investigated. Initially a number of different aspects of indirect background electrolyte (BGE) systems were studied, with the resultant observations indicating the requirements of an 'ideal' BGE system for the separation and detection of common inorganic anions in water samples. In addition to the above the correct use of buffers within BGE us...

  19. The spontaneous motion of a slug of miscible liquids in a capillary tube

    OpenAIRE

    Sellier, Mathieu; Verdier, Claude; Nock, Volker

    2015-01-01

    This contribution explores a droplet actuation mechanism which involves mixing two different liquids slugs in a glass capillary. The resulting contrast in surface tension which arises provides the necessary propulsive power for the droplet. The conceptual idea is demonstrated for an ethanol-water system. The droplet is observed to rapidly reach a peak velocity which then gradually decreases with time as the two miscible liquids mix. A model is proposed based on Newton’s second law which is ab...

  20. Fabrication of Microbeads with a Controllable Hollow Interior and Porous Wall Using a Capillary Fluidic Device

    OpenAIRE

    Choi, Sung-Wook; Zhang, Yu; Xia, Younan

    2009-01-01

    Poly(d,l-lactide-co-glycolide) (PLGA) microbeads with a hollow interior and porous wall are prepared using a simple fluidic device fabricated with PVC tubes, glass capillaries, and a needle. Using the fluidic device with three flow channels, uniform water-in-oil-in-water (W-O-W) emulsions with a single inner water droplet can be achieved with controllable dimensions by varying the flow rate of each phase. The resultant W-O-W emulsions evolve into PLGA microbeads with a hollow interior and por...

  1. Capillary remodeling in bleomycin-induced pulmonary fibrosis.

    OpenAIRE

    Schraufnagel, D. E.; Mehta, D.; Harshbarger, R.; Treviranus, K.; Wang, N. S.

    1986-01-01

    Lung fibrosis is a process in which collagen is laid down and the delicate capillary-alveolar relationship is disturbed. The architectural changes which occur in the capillaries, a main element of the oxygen transferring unit, are difficult to illustrate without a three-dimensional tool, such as scanning electron microscopy. Therefore, a scanning electron microscopic study was undertaken to show the capillary changes of lung fibrosis. Fibrosis was induced in rats by intratracheal instillation...

  2. Nicked-sleeve interface for two-dimensional capillary electrophoresis

    OpenAIRE

    Flaherty, Ryan J.; Huge, Bonnie J.; Bruce, Spencer M.; Dada, Oluwatosin O.; Dovichi, Norman J.

    2013-01-01

    We report an improved interface for two-dimensional capillary electrophoresis. This interface is based on capillary tubing and a Plexiglas chip, both of which were milled using a micro-dicing saw. The interface was evaluated and compared to a traditional interface design for both pseudo one-dimensional and two-dimensional capillary electrophoresis. We observe less than 70% transfer efficiency for the traditional design and greater than 90% transfer efficiency with this new interface.

  3. Modified monolithic silica capillary for preconcentration of catecholamines

    Institute of Scientific and Technical Information of China (English)

    Wei Chang; Tusyo-shi Komazu

    2009-01-01

    Preconcentration of catecholamines by the modified monolithic silica in the capillary was investigated in this study. In order to achieve a microchip-based method for determining catecholamines in the saliva, the monolithic silica was fabricated in the capillary and the monolithic silica was chemically modified by on-column reaction with phenylboronate. Different modified methods were compared. The concentration conditions were optimized. This study indicates the applicability of the modified monolithic silica capillary when it was used to concentrate catecholamines.

  4. Functional capillary rarefaction in mild blood pressure elevation

    OpenAIRE

    Cheng, Cynthia; Diamond, James J.; Falkner, Bonita

    2008-01-01

    Capillary rarefaction is described in patients with moderate to severe hypertension. The study objective was to determine if structural and/or functional capillary rarefaction is detectable and associated with endothelial dysfunction in patients with mild blood pressure elevation (HBP: Systolic blood pressure 130 – 160 mm Hg). Capillary density was quantified by direct capillaroscopy in 110 nondiabetic black and non-black subjects. Endothelial function was quantified by plethysmographic measu...

  5. Interaction of Treponema pallidum with isolated rabbit capillary tissues.

    OpenAIRE

    Quist, E E; Repesh, L A; Zeleznikar, R; Fitzgerald, T J

    1983-01-01

    Within infected tissue Treponema pallidum shows a characteristic predilection for perivascular areas. After intact capillaries had been prepared from rabbit brain tissue treponemes were incubated with isolated capillaries and visualised by darkfield, phase contrast, and scanning electron microscopy. The organisms rapidly attached to the surface of the capillaries at the tip of the treponeme; attached organisms retained motility for longer periods than unattached organisms. Treponema pertenue ...

  6. Capillary Micro-Flow Through a Fiber Bundle(Ⅰ)

    Institute of Scientific and Technical Information of China (English)

    ZHU Ying-dan; WANG Ji-hui; TAN Hua; GAO Guo-qiang

    2004-01-01

    The present work considered the capillary micro-flow through a fiber bundle. The resin heights in the fiber bundle as a function of time were used to determine the experimental values of capillary pressure and the permeability by the nonlinear regression fitting method. The fitting curves showed a good agreement with experiments. However, these values of capillary pressure from short- time experiments were much lower than the theoretical results from the Yang-Laplace Equation. More accurate capillary pressure was predicted from the presented long-run experiment.

  7. High Performance Wafer-Based Capillary Electrochromatography Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Phase II research comprises designing, constructing, and testing a chip-based capillary electrochromatography (CEC) prototype for separation and analysis of...

  8. Creeping motion of long bubbles and drops in capillary tubes

    DEFF Research Database (Denmark)

    Westborg, Henrik; Hassager, Ole

    1989-01-01

    The flow of inviscid bubbles and viscous drops in capillary tubes has been simulated by a Galerkin finite element method with surface tension included at the bubble/liquid interface. The results show good agreement with published experimental results. At low capillary numbers the front and the rear...... disappear at high capillary numbers. Furthermore the flow of a viscous drop through a doughnut shaped constriction in a capillary tube has been simulated. The simulations show that snap-off may be initiated by a sudden drop in the flow rate after the drops have protruded for some distance beyond the throat...

  9. Novel Micro-Capillary Electrochromatography for Mars Organic Detector Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Los Gatos Research proposes to develop a powerful new technology - next generation Micro-Capillary Electrochromatography - a high performance and low power...

  10. Novel Micro-Capillary Electrochromatography for Mars Organic Detector Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Los Gatos Research proposes to develop a powerful new technology - next generation Micro-Capillary Electrochromatography ? a high performance and low power...

  11. Capillary pericytes regulate cerebral blood flow in health and disease

    DEFF Research Database (Denmark)

    Hall, Catherine N; Reynell, Clare; Gesslein, Bodil;

    2014-01-01

    that neuronal activity and the neurotransmitter glutamate evoke the release of messengers that dilate capillaries by actively relaxing pericytes. Dilation is mediated by prostaglandin E2, but requires nitric oxide release to suppress vasoconstricting 20-HETE synthesis. In vivo, when sensory input...... increases blood flow, capillaries dilate before arterioles and are estimated to produce 84% of the blood flow increase. In pathology, ischaemia evokes capillary constriction by pericytes. We show that this is followed by pericyte death in rigor, which may irreversibly constrict capillaries and damage the...

  12. Capacitively coupled contactless conductivity detection and sequential injection analysis in capillary electrophoresis and capillary electro-chromatography

    OpenAIRE

    Mai, Thanh Duc

    2011-01-01

    This thesis focuses on the applications of capacitively coupled contactless conductivity detection (C4D) in capillary electrophoresis (CE) hybridized with high-performance liquid chromatography (HPLC), i.e. in capillary electrochromatography and pressure-assisted capillary electrophoresis, as well as on the development and applications of an extension of CE-C4D with sequential injection analysis (SIA). At first, the in-house built C4D was used for electro-chromatographic determinations of...

  13. Determination of glycyrrhizin in liqueurs by on-line coupled capillary isotachophoresis with capillary zone electrophoresis.

    Science.gov (United States)

    Kvasnicka, Frantisek; Voldrich, Michal; Vyhnálek, Josef

    2007-10-26

    An on-line coupled capillary isotachophoresis-capillary zone electrophoresis method for the determination of glycyrrhizin in liqueurs is described. The optimised electrolyte system was 5 mM HCl+11 mM epsilon-aminocaproic acid+0.05% hydroxyethylcellulose+30% methanol (leading electrolyte), 5 mM caproic acid+30% methanol (terminating electrolyte) and 20 mM caproic acid+10 mM histidine+0.1% hydroxyethylcellulose+30% methanol (background electrolyte). Method characteristics, i.e., linearity (20-500 ng/ml), accuracy (recovery 99+/-4%), intra-assay repeatability (2%), intermediate repeatability (3.8%) and detection limit (8 ng/ml) were determined. Speed of analysis, low laboriousness, high sensitivity and low-running cost are the typical attributes of the capillary isotachophoresis-capillary zone electrophoresis method. Developed method was successfully applied to analysis of liqueurs with liquorice extract and some foods (sweets and food supplements) containing liquorice. Found levels of glycyrrhizin in liqueurs, sweets and food supplements varied between 1-16 mg/l, 850-1050 mg/kg and 1.6-1.8 g/kg, respectively. PMID:17875310

  14. Capillary zone electrophoresis and packed capillary column liquid chromatographic analysis of recombinant human interleukin-4.

    Science.gov (United States)

    Bullock, J

    1993-02-24

    Capillary zone electrophoresis (CZE) and packed capillary column liquid chromatography (micro-LC) have been applied to the analysis of the recombinant human protein interleukin-4 (rhIL-4). Separations for both the parent protein and its enzymatic digest were developed for the purpose of characterizing protein purity and identity. CZE separations of the intact protein were investigated over the pH range of 4.5 to 8.0 using uncoated fused silica capillaries. Gradient reversed-phase micro-LC was performed using 0.32 mm packed capillary columns at flow-rates of 5-6 microliters/min. Emphasis was placed on the ability of these methods to separate close structural variants and degradation products of the protein. Peptide mapping of the tryptic digest of rhIL-4 using a combination of CZE and micro-LC provided complimentary high resolution methods for establishing protein identity. Reproducible separations were achieved using sub-picomol amounts of sample. The advantages and problems encountered with these two techniques for characterizing rhIL-4 were assessed. PMID:8450025

  15. Electroviscous effects in capillary filling of nanochannels

    DEFF Research Database (Denmark)

    Mortensen, Asger; Kristensen, Anders

    2008-01-01

    maximum in the mesoscopic regime where the channel height (or more generally the hydraulic radius) is comparable to the screening length. However, for realistic estimates of central parameters, we find that the electroviscous contribution to the apparent viscosity is at most a 1% effect.......We theoretically examine the widespread hypothesis of an electroviscous origin of the increase in apparent viscosity observed in recent experiments on capillary filling of nanochannels. Including Debye-layer corrections to the hydraulic resistance, we find that the apparent viscosity reaches a...

  16. Gas-Filled-Capillary Discharge Experiment

    Czech Academy of Sciences Publication Activity Database

    Schmidt, Jiří; Koláček, Karel; Frolov, Oleksandr; Prukner, Václav; Štraus, Jaroslav; Sobota, Jaroslav; Fořt, Tomáš

    Washington, DC: IEEE, 2010, s. 707-709. (IEEE Xplore). ISBN 978-1-4244-4064-1. [IEEE International Pulsed Power Conference/17th./. Washington, D.C. (US), 28.06.2010-02.07.2010] R&D Projects: GA MŠk(CZ) LC528; GA MŠk LA08024; GA AV ČR KJB100430702; GA AV ČR KAN300100702 Institutional research plan: CEZ:AV0Z20430508; CEZ:AV0Z20650511 Keywords : Capillary discharge * x-ray * laser Subject RIV: BL - Plasma and Gas Discharge Physics http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=5386405

  17. Analysis of antimicrobial peptides by capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Ehala, Sille; Niederhafner, Petr; Čeřovský, Václav; Řezanka, P.; Sýkora, D.; Král, V.; Kašička, Václav

    Praha : Institute of Organic Chemistry and Biochemistry AS CR, v. v. i, 2011 - (Slaninová, J.), s. 37-40 ISBN 978-80-86241-44-9. - (Collection Symposium Series. 13). [Biologically Active Peptides /12./. Praha (CZ), 27.04.2011-29.04.2011] R&D Projects: GA ČR(CZ) GA203/09/0675; GA ČR(CZ) GA203/08/1428 Institutional research plan: CEZ:AV0Z40550506 Keywords : capillary electrophoresis * antimicrobial peptides * gold nanoparticles Subject RIV: CC - Organic Chemistry

  18. High sensitivity radiation detector for capillary electrophoresis

    International Nuclear Information System (INIS)

    Capillary electrophoresis is an important new instrumental technique capable of high resolution separation and analysis of small quantities of nucleotides, amino acids, peptides, and proteins with very high efficiency and throughput. The unprecedented sensitivity of this technique will be useful for such new applications as in vivo labeling and identification of trace substances and single cell work. The principle limitation of this technique for radiolabeled molecules has been identified as the sensitivity of the detector, primarily due to the small sample volume (32P-labeled biomolecules with unprecedented sensitivity. This detector can be easily retrofitted into existing CE apparatus

  19. Study of antimicrobial peptides by capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Tůmová, Tereza; Monincová, Lenka; Čeřovský, Václav; Kašička, Václav

    Sofia: Bulgarian Peptide Society, 2015 - (Naydenova, E.; Pajpanova, T.; Danalev, D.), s. 304-305 ISBN 978-619-90427-2-4. [Peptides 2014. European Peptide Symposium /33./. Sofia (BG), 31.08.2014-05.09.2014] R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR(CZ) GA13-17224S Institutional support: RVO:61388963 Keywords : peptides * antimicrobial activity * capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation http://bulpepsoc.info/wp-content/uploads/2015/06/PEPTIDES-2014-electronic-version.pdf

  20. Gas-Filled-Capillary Discharge Experiment

    Czech Academy of Sciences Publication Activity Database

    Schmidt, Jiří; Koláček, Karel; Frolov, Oleksandr; Prukner, Václav; Štraus, Jaroslav

    Vol. IEEE Catalog Number: CFP09PPC. Piscataway : Institute of Electrical and Electronics Engineers, Inc, 2009. s. 245-245. ISBN 978-1-4244-4065-8. [IEEE International Pulsed Power Conference/17th./. 28.06.2009-02.07.2009, Washington, D.C.] R&D Projects: GA MŠk LA08024; GA AV ČR KJB100430702; GA AV ČR KAN300100702; GA MŠk(CZ) LC528 Institutional research plan: CEZ:AV0Z20430508 Keywords : Capillary discharge * x-ray * laser Subject RIV: BL - Plasma and Gas Discharge Physics http://ppc.missouri.edu/Abstracts.pdf

  1. Capillary Network, Cancer and Kleiber Law

    CERN Document Server

    Dattoli, G; Licciardi, S; Guiot, C; Deisboeck, T S

    2014-01-01

    We develop a heuristic model embedding Kleiber and Murray laws to describe mass growth, metastasis and vascularization in cancer. We analyze the relevant dynamics using different evolution equations (Verhulst, Gompertz and others). Their extension to reaction diffusion equation of the Fisher type is then used to describe the relevant metastatic spreading in space. Regarding this last point, we suggest that cancer diffusion may be regulated by Levy flights mechanisms and discuss the possibility that the associated reaction diffusion equations are of the fractional type, with the fractional coefficient being determined by the fractal nature of the capillary evolution.

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

    Science.gov (United States)

    Moreno-Gordaliza, Estefanía; Stigter, Edwin C A; Lindenburg, Petrus W; Hankemeier, Thomas

    2016-06-01

    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(-9) m(2) V(-1) s(-1)) when compared with unmodified fused silica (5.9 ± 0.1 10(-8) m(2) V(-1) s(-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. PMID:27155306

  3. Transverse vertical dispersion coefficients in the capillary fringe determined by a high resolution non-invasive method

    Science.gov (United States)

    Haberer, C. M.; Grathwohl, P.

    2009-12-01

    Mass transfer from the unsaturated to the saturated zone across the capillary fringe is a common mechanism for groundwater contamination by volatile compounds (McCarthy and Johnson 1993) but also for oxygen supply. Oxygen plays an important role for microbial processes in groundwater - either by influencing the redox conditions directly or by replenishing electron acceptors needed for microbial growth and respiration. Hydrodynamic transverse dispersion was found to be essential for the mass transfer of vapor phase compounds across the capillary fringe (Klenk and Grathwohl 2002). Thus the objective of this work was to determine transverse vertical dispersion coefficients in this transition zone and a non-invasive method was developed to measure oxygen gradients across the saturated/unsaturated interface at grain scale resolution. Bench-scale 2D-flow through experiments have been conducted and different horizontal flow velocities, grain sizes, water table fluctuation amplitudes and frequencies have been applied. Vertical oxygen concentration profiles across the capillary fringe were subsequently measured at distinct positions in flow direction and evaluated with regard to mass transfer of oxygen from the unsaturated to the saturated zone. To the authors knowledge this is the first time where the fibre optical sensor technique to measure oxygen concentrations is applied to this transition zone. Transverse dispersion coefficients were calculated for steady state flow conditions. Under transient conditions, i.e. having changed the position of the water table, the measured concentration profiles are different with regard to the process of imbibition or drainage. Whereas drainage does not produce a significant change in concentration profiles compared to the stationary case, increasing water tables result in entrapment of air bubbles, and thus also a flatter gradient in oxygen concentrations. The gradual dissolution of entrapped oxygen into the bypassing oxygen

  4. CMOS absorbance detection system for capillary electrophoresis

    International Nuclear Information System (INIS)

    This paper presents a cost-effective portable photodetection system for capillary electrophoresis absorptiometry. By using a CMOS BDJ (buried double p-n junction) detector, a dual-wavelength method for absorbance measurement is implemented. This system includes associated electronics for low-noise pre-amplification and A/D conversion, followed by digital signal acquisition and processing. Two signal processing approaches are adopted to enhance the signal to noise ratio. One is variable time synchronous detection, which optimizes the sensitivity and measuring rate compared to a conventional synchronous detection technique. The other is a statistical approach based on principal component analysis, which allows optimal estimation of detected signal. This system has been designed and tested in capillary electrophoresis conditions. Its operation has been verified with performances comparable to those of a commercialized spectrophotometric system (HP-3D CE). With potential on-chip integration of associated electronics, it may be operated as an integrable detection module for microchip electrophoresis and other microanalysis systems

  5. Capillary Electrophoresis coupled with Automated Fraction Collection

    Science.gov (United States)

    Huge, Bonnie Jaskowski; Flaherty, Ryan; Dada, Oluwatosin O.; Dovichi, Norman J.

    2014-01-01

    A fraction collector based on a drop-on-demand ink-jet printer was developed to interface capillary zone electrophoresis with a 96 well microtiter plate. We first evaluated the performance of the collector by using capillary zone electrophoresis to analyze a 1 mM solution of tetramethylrhodamine; a fluorescent microtiter plate reader was then used to detect the analyte and characterize fraction carryover between wells. Relative standard deviation in peak height was 20% and the relative standard deviation in migration time was 1%. The mean and standard deviation of the tetramethylrhodamine peak width was 5 ± 1 s and likely limited by the 4-s period between droplet deposition. We next injected a complex mixture of DNA fragments and used real-time PCR to quantify the product in a CE-SELEX experiment. The reconstructed electrophoretic peak was 27 s in duration. Finally, we repeated the experiment in the presence of a 30-μM thrombin solution under CE-SELEX conditions; fractions were collected and next-generation sequencing was used to characterize the DNA binders. Over 25,000 sequences were identified with close matches to known thrombin binding aptamers. PMID:25159411

  6. Capillary electrophoresis coupled with automated fraction collection.

    Science.gov (United States)

    Huge, Bonnie Jaskowski; Flaherty, Ryan J; Dada, Oluwatosin O; Dovichi, Norman J

    2014-12-01

    A fraction collector based on a drop-on-demand ink-jet printer was developed to interface capillary zone electrophoresis with a 96 well microtiter plate. We first evaluated the performance of the collector by using capillary zone electrophoresis to analyze a 1mM solution of tetramethylrhodamine; a fluorescent microtiter plate reader was then used to detect the analyte and characterize fraction carryover between wells. Relative standard deviation in peak height was 20% and the relative standard deviation in migration time was 1%. The mean and standard deviation of the tetramethylrhodamine peak width was 5 ± 1 s and likely limited by the 4-s period between droplet deposition. We next injected a complex mixture of DNA fragments and used real-time PCR to quantify the product in a CE-SELEX experiment. The reconstructed electrophoretic peak was 27 s in duration. Finally, we repeated the experiment in the presence of a 30-µM thrombin solution under CE-SELEX conditions; fractions were collected and next-generation sequencing was used to characterize the DNA binders. Over 25,000 sequences were identified with close matches to known thrombin binding aptamers. PMID:25159411

  7. Differentiation of enantiomers by capillary electrophoresis.

    Science.gov (United States)

    Scriba, Gerhard K E

    2013-01-01

    Capillary electrophoresis (CE) has matured to one of the major liquid phase enantiodifferentiation techniques since the first report in 1985. This can be primarily attributed to the flexibility as well as the various modes available including electrokinetic chromatography (EKC), micellar electrokinetic chromatography (MEKC), and microemulsion electrokinetic chromatography (MEEKC). In contrast to chromatographic techniques, the chiral selector is mobile in the background electrolyte. Furthermore, a large variety of chiral selectors are available that can be easily combined in the same separation system. In addition, the migration order of the enantiomers can be adjusted by a number of approaches. In CE enantiodifferentiations the separation principle is comparable to chromatography while the principle of the movement of the analytes in the capillary is based on electrophoretic phenomena. The present chapter will focus on mechanistic aspects of CE enantioseparations including enantiomer migration order and the current understanding of selector-selectand structures. Selected examples of the basic enantioseparation modes EKC, MEKC, and MEEKC will be discussed. PMID:23666080

  8. A two-dimensional model of the pressing section of a paper machine including dynamic capillary effects

    KAUST Repository

    Iliev, Oleg P.

    2013-05-15

    Paper production is a problem with significant importance for society; it is also a challenging topic for scientific investigation. This study is concerned with the simulation of the pressing section of a paper machine. A two-dimensional model is developed to account for the water flow within the pressing zone. A Richards-type equation is used to describe the flow in the unsaturated zone. The dynamic capillary pressure-saturation relation is adopted for the paper production process. The mathematical model accounts for the coexistence of saturated and unsaturated zones in a multilayer computational domain. The discretization is performed by the MPFA-O method. Numerical experiments are carried out for parameters that are typical of the production process. The static and dynamic capillary pressure-saturation relations are tested to evaluate the influence of the dynamic capillary effect. © 2013 Springer Science+Business Media Dordrecht.

  9. A FORTRAN program for interpretation of relative permeability from unsteady-state displacements with capillary pressure included

    Science.gov (United States)

    Udegbunam, E.O.

    1991-01-01

    This paper presents a FORTRAN program for the determination of two-phase relative permeabilities from unsteady-state displacement data with capillary pressure terms included. The interpretative model employed in this program combines the simultaneous solution of a variant of the fractional flow equation which includes a capillary pressure term and an integro-differential equation derived from Darcy's law without assuming the simplified Buckley-Leverett flow. The incorporation of capillary pressure in the governing equations dispenses with the high flowrate experimental requirements normally employed to overcome capillarity effects. An illustrative example is presented herein which implements this program for the determination of oil/water relative permeabilities from a sandstone core sample. Results obtained compares favorably with results previously given in the literature. ?? 1991.

  10. Improvements of the experimental apparatus for measurement of the surface tension of supercooled liquids using horizontal capillary tube

    Science.gov (United States)

    Vinš, Václav; Hošek, Jan; Hykl, Jiří; Hrubý, Jan

    2016-03-01

    An experimental apparatus with a horizontal capillary tube for measurement of the surface tension of supercooled liquids, i.e. liquids in a metastable state below the equilibrium freezing point, was designed and tested in the previous study [V. Vinš et al., EPJ Web Conf. 92, 02108 (2015)]. In this work, recent modifications of both the experimental setup and the measurement analysis are described. The main aim is to improve the accuracy and the reproducibility of measured surface tension and to achieve higher degrees of supercooling. Temperature probes measuring the temperature of cooling medium near the horizontal capillary tube were calibrated in the relevant temperature range from - 31 °C to + 45 °C. An additional pressure transducer was installed in the helium distribution setup at the position close to the capillary tube. The optical setup observing the liquid meniscus at the open end of the horizontal capillary tube together with the video analysis were thoroughly revised. The red laser illuminating the liquid meniscus, used at the original apparatus, was replaced by a fiber optic light source, which significantly improved the quality of the meniscus image. The modified apparatus was used for the measurement of surface tension of supercooled water at temperatures down to - 11 °C. The new data have a lower scatter compared to the previous horizontal measurements and show a good agreement with the other data obtained with a different measurement technique based on the modified capillary rise method.

  11. Soft x-ray amplification in an ablative capillary discharge

    International Nuclear Information System (INIS)

    Soft x-ray amplification in CVI 18.2 nm line is observed in an ablative UHMW-PE capillary discharge. The gain coefficient is measured to be 1.9 cm-1. The electron density is about 2 x 1019 cm-3. This indicates that capillary discharge pumping device can be a source for a compact soft x-ray laser. (author)

  12. Analysis of organic acids in Macedonian wines by capillary electrophoresis

    OpenAIRE

    Jancovska, Maja; Ivanova, Violeta; Gulaboski, Rubin; Belder, Detlev

    2013-01-01

    Capillary electrophoresis as a separation technique can be applied for analysis of organic acids in white and red wines, providing high resolution separation of the analytes. Organic acids such as of tartaric, malic, lactic citric and succinic acids have been analysed in many Macedonian red and white wines by capillary electrophoresis, and results have been discussed.

  13. Characterization and identification of microorganisms by capillary electrophoretic techniques

    Czech Academy of Sciences Publication Activity Database

    Moravcová, Dana; Horká, Marie; Vykydalová, Marie; Kubesová, Anna; Růžička, F.

    2014. s. 1-1. [World Congress on Targeting Microbiota - Towards Clinical Revolution /2./. 16.10.2014-17.10.2014, Paris] R&D Projects: GA MV VG20112015021 Institutional support: RVO:68081715 Keywords : capillary electrophoresis * capillary isoelectric focusing * bacteria Subject RIV: CB - Analytical Chemistry, Separation

  14. Blepharospasm in a patient with pontine capillary telangiectasia

    OpenAIRE

    Gilbert, AL; Dillon, WP; Horton, JC

    2012-01-01

    Blepharospasm is rarely due to an identifiable etiology. In the majority of cases, imaging fails to reveal any structural lesion. Here we describe an otherwise healthy patient with blepharospasm who was found to have pontine capillary telangiectasia. We propose a potential association between blepharospasm and pontine capillary telangiectasia. © 2012 The American Society of Ophthalmic Plastic and Reconstructive Surgery, Inc.

  15. A capillary pumping device utilizing super-hydrophobic silicon grass

    International Nuclear Information System (INIS)

    In this study, we show that a compact silicon grass surface can be generated by utilizing the induced coupled plasma method with suitably chosen fabrication parameters. This super-hydrophobic structure suspends deionized water on top of the grass and keeps the contact angle at around 153°. The silicon grass is used to improve the driving efficiency of a capillary pumping micro-duct (without sidewalls), which is completely defined by a bottom hydrophilic stripe (adjacent to a Teflon substrate) and a fully top-covered hydrophobic Teflon surface which is coated on a glass substrate. The channel has a height of 3 µm and a width of 100 µm. In this work, the Teflon substrate is replaced with the silicon grass surface. When the fluid is flowing through the micro-duct on the stripe, the interface between the silicon grass and the hydrophilic stripe forms a stable air cushion barrier to the fluid, thus effectively reducing the frictional force. By changing only the interface with this replacement, we demonstrate that the average measured velocities of the new design show improvements of 21% and 17% in the driving efficiency over the original design for transporting deionized water and human blood, respectively. It is also shown that the measured data of the present design are closer to the values predicted by a theoretical analysis which relates the flow velocity to the contact angles, surface tension and fluid viscosity

  16. Diffusing light photography of solitons and capillary-wave turbulence

    Energy Technology Data Exchange (ETDEWEB)

    Wright, W.; Budak, R.; Putterman, S. (Phys. Dept., UCLA, Los Angeles, CA 90024 (United States))

    1994-11-01

    The attenuation of light propagating through a slab of water (containing a dilute concentration of polyballs) is approximately proportional to its thickness. Application of this insight to the local elevation of a fluid surface has enabled us to use photography to determine the instantaneous global topography of the surface of a fluid in motion. Use of diffusing light enables us to obtain images that are free of the caustics which plague shadowgraphs. Applications include breather solitons and wave turbulence which results from the nonlinear interaction of a broadband spectrum of high amplitude surface ripples. Measurements indicate that as the amplitude of excitation of the surface of water is increased the wave number of the capillary motion displays a transition to a broadband spectrum. The temporal response of a single pixel yields the power spectrum of the surface height as a function of frequency [ital f].'' The numerous harmonics which can be seen at low amplitude merge at high amplitude into a broadband spectrum which goes as 1/[ital f][sup 3]. This technique should permit the measurement of turbulent parameters which go beyond the purported range of current theories. [Work supported by US DOE Division of Engineering and Geophysics and NASA Microgravity.

  17. Washing wedges: a capillary instability in a gradient of confinement

    Science.gov (United States)

    Keiser, Ludovic; Herbaut, Remy; Bico, Jose; Reyssat, Etienne

    2015-11-01

    When a drop of oil is introduced into a gradient of confinement (two glass plates forming a sharp wedge) capillary forces drive it toward the most confined regions, where the solid-fluid contact area is maximal. A surfactant solution subsequently introduced into the wedge undergoes the same movement until it reaches the oil previously added. If the aqueous phase wets the solid better than the oil, a complex exchange process between both phases occurs. The water-oil interface destabilizes, oil fingers grow in the water phase, pinch-off and lead to the formation of droplets that migrate away from the tip of the wedge. The whole oil phase is eventually extracted. A linear stability analysis of the interface is presented and captures the size of the oil droplets. The dynamics of the system is however not perfectly explained by a simple Poiseuille flow. Indeed, more refined models should account for the dissipation in meniscii and lubrication films. Finally, we suggest that our model experiment may constitute a useful tool to select optimal systems for oil recovery processes.

  18. Diffusing light photography of solitons and capillary-wave turbulence

    International Nuclear Information System (INIS)

    The attenuation of light propagating through a slab of water (containing a dilute concentration of polyballs) is approximately proportional to its thickness. Application of this insight to the local elevation of a fluid surface has enabled us to use photography to determine the instantaneous global topography of the surface of a fluid in motion. Use of diffusing light enables us to obtain images that are free of the caustics which plague shadowgraphs. Applications include breather solitons and wave turbulence which results from the nonlinear interaction of a broadband spectrum of high amplitude surface ripples. Measurements indicate that as the amplitude of excitation of the surface of water is increased the wave number of the capillary motion displays a transition to a broadband spectrum. The temporal response of a single pixel yields the power spectrum of the surface height as a function of frequency ''f.'' The numerous harmonics which can be seen at low amplitude merge at high amplitude into a broadband spectrum which goes as 1/f3. This technique should permit the measurement of turbulent parameters which go beyond the purported range of current theories. [Work supported by US DOE Division of Engineering and Geophysics and NASA Microgravity.

  19. Callibration of capillaries for density measurement of supercooled water

    Czech Academy of Sciences Publication Activity Database

    Peukert, Pavel; Duška, Michal; Hykl, Jiří; Sladký, Petr; Nikl, Zbyněk; Hrubý, Jan

    Les Ulis Cedex : E D P SCIENCES, 2015 - (Dančová, P.; Vít, T.), s. 469-474 ISSN 2100-014X. - (EPJ Web of Conferences). [Experimental Fluid Mechanics 2014. Český Krumlov (CZ), 18.11.2014-21.11.2014] R&D Projects: GA ČR(CZ) GAP101/11/1593; GA MŠk LA09011 Institutional support: RVO:61388998 Keywords : capillar * calibration * method

  20. Linear surface capillary-gravity short-crested waves on a current

    Institute of Scientific and Technical Information of China (English)

    HUANG Hu

    2008-01-01

    One of the forward situations in the study of water waves is the basic three-dimensional surface wave motion of short-crested waves. Capillary waves result in rich effects concerned closely with remote sensing in the open ocean. Ocean currents experience a complete process in surface wave motion. Based on the above ideas, a linear dynamical system of surface capillary-gravity short-crested waves is developed by considering the current effects, thus leading to the following analytical expressions of the kinematic and dynamic variables: the wave height, the wave steepness, the phase velocity, the wave-particle velocities, accelerations and trajectories and the wave pressure. A number of the classi-cal, typical and latest special wave cases can arise from these expressions.

  1. Single microdroplet ejection using an ultrasonic longitudinal mode with a PZT/tapered glass capillary.

    Science.gov (United States)

    Lee, Chung-Hoon; Lal, Amit

    2004-11-01

    We have developed an ultrasonic PZT/tapered glass capillary resonant actuator that can eject a single droplet every acoustic cycle without also generating satellite droplets. The mechanism of the actuation is resonant longitudinal motion-induced squeezing of a tapered volume. The actuator is driven at 160 kHz and requires voltages less than 2 Vpp to operate. In this paper, the droplet generation of isopropanol and water mixtures, which have different densities, viscosities, and surface tensions, is investigated. It is determined that the geometrical squeezing mechanism and the ejected jet breakup makes the droplet size independent of frequency, but more a function of the ejecting orifice diameter that is much smaller than the capillary wavelength. PMID:15600097

  2. Determination of Na and Al Ions in Semiconductor Cleaning Solution Using Capillary Electrophoresis

    International Nuclear Information System (INIS)

    The most common process chemical used in the manufacturing process is a standard cleaning (SC) solution, a mixture of ammonia and hydrogen peroxide in deionized water. Since the purity of the SC solution used in the process has been required to the level of sub-ppb range, accurate and reliable determination of ionic contaminants becomes increasingly difficult. In order to satisfy the requirement of impurity control, inductively coupled plasma-mass spectrometer (ICP-MS), graphite furnace atomic absorption spectrometer (GFAAS), and ion chromatography (IC) are currently the most common analytical instruments used in the process. However, those instruments are not designed for on-line monitoring but rather for off-line analysis. Recently, separation and detection of various particles, such as cells and nanoparticles, with capillary electrophoresis (CE) was reported, although the application of CE has been mostly limited to organic or biological samples. Capillary electrophoresis has been emerging as an alternative to ICPAES and AAS for trace metal analysis

  3. Water

    International Nuclear Information System (INIS)

    An up-date overview of the situation of the Austrian waters is given by analyzing the status of the water quality (groundwater, surface waters) and water protection measures. Maps containing information of nitrate and atrazine in groundwaters (analyses at monitoring stations), nitrate contents and biological water quality of running waters are included. Finally, pollutants (nitrate, orthophosphate, ammonium, nitrite, atrazine etc.) trends in annual mean values and median values for the whole country for the years 1992-1999 are presented in tables. Figs. 5. (nevyjel)

  4. Highly efficient capillary polymerase chain reaction using an oscillation droplet microreactor

    Energy Technology Data Exchange (ETDEWEB)

    Liu Dayu, E-mail: ruark@126.com [Laboratory of Clinical Chemical Technology, Department of Laboratory Medicine, Guangzhou First Municipal People' s Hospital, Affiliated to Guangzhou Medical College, 510180 Guangzhou (China); Liang Guangtie; Lei Xiuxia; Chen Bin; Wang Wei [Laboratory of Clinical Chemical Technology, Department of Laboratory Medicine, Guangzhou First Municipal People' s Hospital, Affiliated to Guangzhou Medical College, 510180 Guangzhou (China); Zhou Xiaomian, E-mail: zhouximi@yahoo.com [Laboratory of Clinical Chemical Technology, Department of Laboratory Medicine, Guangzhou First Municipal People' s Hospital, Affiliated to Guangzhou Medical College, 510180 Guangzhou (China)

    2012-03-09

    Graphical abstract: An oscillation-flow approach using a droplet reactor was developed to fully explore the potential of continuous-flow PCR. By fully utilizing interfacial chemistry, a water-in-oil (w/o) droplet was automatically generated by allowing an oil-water plug to flow through a polytetrafluoroethylene (PTFE) capillary. Due to the movement of aqueous phase relative to the oil phase, the droplet moves further into the middle of the oil plug with increase in migration distance. The resulting droplet was transported spanning the two heating zones and was employed as the reactor of oscillating-flow PCR. Highlights: Black-Right-Pointing-Pointer Droplet formation in a capillary. Black-Right-Pointing-Pointer Transport the droplet using oscillation-flow. Black-Right-Pointing-Pointer Oscillation droplet PCR. Black-Right-Pointing-Pointer Improved reaction efficiency. - Abstract: The current work presents the development of a capillary-based oscillation droplet approach to maximize the potential of a continuous-flow polymerase chain reaction (PCR). Through the full utilization of interfacial chemistry, a water-in-oil (w/o) droplet was generated by allowing an oil-water plug to flow along a polytetrafluoroethylene (PTFE) capillary. The w/o droplet functioned as the reactor for oscillating-flow PCR to provide a stable reaction environment, accelerate reagent mixing, and eliminate surface adsorption. The capillary PCR approach proposed in the current research offers high amplification efficiency, fast reaction speed, and easy system control attributable to the oscillation droplet reactor. Experimental results show that the droplet-based micro-PCR assay requires lower reaction volume (2 {mu}L) and shorter reaction time (12 min) compared with conventional PCR methods. Taking the amplification of the New Delhi metallo-beta-lactamase (NDM-1) gene as an example, the present work demonstrates that the oscillation droplet PCR assay is capable of achieving high efficiency up to

  5. Highly efficient capillary polymerase chain reaction using an oscillation droplet microreactor

    International Nuclear Information System (INIS)

    Graphical abstract: An oscillation-flow approach using a droplet reactor was developed to fully explore the potential of continuous-flow PCR. By fully utilizing interfacial chemistry, a water-in-oil (w/o) droplet was automatically generated by allowing an oil–water plug to flow through a polytetrafluoroethylene (PTFE) capillary. Due to the movement of aqueous phase relative to the oil phase, the droplet moves further into the middle of the oil plug with increase in migration distance. The resulting droplet was transported spanning the two heating zones and was employed as the reactor of oscillating-flow PCR. Highlights: ► Droplet formation in a capillary. ► Transport the droplet using oscillation-flow. ► Oscillation droplet PCR. ► Improved reaction efficiency. - Abstract: The current work presents the development of a capillary-based oscillation droplet approach to maximize the potential of a continuous-flow polymerase chain reaction (PCR). Through the full utilization of interfacial chemistry, a water-in-oil (w/o) droplet was generated by allowing an oil–water plug to flow along a polytetrafluoroethylene (PTFE) capillary. The w/o droplet functioned as the reactor for oscillating-flow PCR to provide a stable reaction environment, accelerate reagent mixing, and eliminate surface adsorption. The capillary PCR approach proposed in the current research offers high amplification efficiency, fast reaction speed, and easy system control attributable to the oscillation droplet reactor. Experimental results show that the droplet-based micro-PCR assay requires lower reaction volume (2 μL) and shorter reaction time (12 min) compared with conventional PCR methods. Taking the amplification of the New Delhi metallo-beta-lactamase (NDM-1) gene as an example, the present work demonstrates that the oscillation droplet PCR assay is capable of achieving high efficiency up to 89.5% and a detection limit of 10 DNA copies. The miniature PCR protocol developed in the current

  6. Validation of STR typing by capillary electrophoresis.

    Science.gov (United States)

    Moretti, T R; Baumstark, A L; Defenbaugh, D A; Keys, K M; Brown, A L; Budowle, B

    2001-05-01

    With the use of capillary electrophoresis (CE), high-resolution electrophoretic separation of short tandem repeat (STR) loci can be achieved in a semiautomated fashion. Laser-induced detection of fluorescently labeled PCR products and multicolor analysis enable the rapid generation of multilocus DNA profiles. In this study, conditions for typing PCR-amplified STR loci by capillary electrophoresis were investigated using the ABI Prism 310 Genetic Analyzer (Applied Biosystems). An internal size standard was used with each run to effectively normalize mobility differences among injections. Alleles were designated by comparison to allelic ladders that were run with each sample set. Multiple runs of allelic ladders and of amplified samples demonstrate that allele sizes were reproducible, with standard deviations typically less than 0.12 bases for fragments up to 317 bases in length (largest allele analyzed) separated in a 47 cm capillary. Therefore, 99.7% of all alleles that are the same length should fall within the measurement error window of +/- 0.36 bases. Microvariants of the tetranucleotide repeats were also accurately typed by the analytical software. Alleles differing in size by one base could be resolved in two-donor DNA mixtures in which the minor component comprised > or = 5% of the total DNA. Furthermore, the quantitative data format (i.e., peak amplitude) can in some instances assist in determining individual STR profiles in mixed samples. DNA samples from previously typed cases (typed for RFLP, AmpliType PM+DQA1, and/or D1S80) were amplified using AmpFlSTR Profiler Plus and COfiler and were evaluated using the ABI Prism 310. Most samples yielded typable results. Compared with previously determined results for other loci, there were no discrepancies as to the inclusion or exclusion of suspects or victims. CE thus provides efficient separation, resolution, sensitivity and precision, and the analytical software provides reliable genotyping of STR loci. The

  7. Rapid capillary coating by epoxy-poly-(dimethylacrylamide): Performance in capillary zone electrophoresis of protein and polystyrene carboxylate

    Czech Academy of Sciences Publication Activity Database

    Chiari, M.; Cretich, M.; Šťastná, Miroslava; Radko, S. P.; Chrambach, A.

    2001-01-01

    Roč. 22, č. 4 (2001), s. 656-659. ISSN 0173-0835 Institutional research plan: CEZ:AV0Z4031919 Keywords : capillary coating * capillary zone electrophoresis * proteins Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.282, year: 2001

  8. Silica-based monolithic capillary columns modified by liposomes for characterization of analyte-liposome interactions by capillary liquid chromatography

    Czech Academy of Sciences Publication Activity Database

    Moravcová, Dana; Planeta, Josef; Wiedmer, S. K.

    2013. P-269-W. [International Symposium on Capillary Chromatography /37./ and GC×GC Symposium /10./. 12.05.2013-16.05.2013, Palm Springs] R&D Projects: GA ČR(CZ) GAP206/11/0138; GA MV VG20112015021 Institutional support: RVO:68081715 Keywords : monolithic silica capillary column * immobilized liposomes * biomimicking stationary phase Subject RIV: CB - Analytical Chemistry, Separation

  9. Determination of Amino Acids in Single Human Lymphocytes after On-capillary Derivatization by Capillary Zone Electrophoresis with Electrochemical Detection

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Amino acids in individual human lymphocytes were determined by capillary zone electrophoresis with electrochemical detection after on-capillary derivatization. In order to inject cells easily, a cell injector was designed. Four amino acids (serine, alanine, taurine, and glycine) in single human lymphocytes have been identified. Quantitation has been accomplished through the use of calibration curves.

  10. Unsteady motion of the parasitic capillary ripples on the gravity-capillary waves

    International Nuclear Information System (INIS)

    Parasitic capillary ripples generated on the forward face of the gravity-capillary waves are investigated experimentally. Using the optical technique, the slope angle of the wave is measured with sufficient space and time resolution to characterize the small ripple fluctuations. The ripple generation and its steepness is considered from the point of dominant wave asymmetry. The unsteady motion of ripples is analyzed by the two-points optical measurements. Dominant wave has the same phase speed with ripple on average, however the relative distance to the dominant wave fluctuates which can't be negligible comparing with the ripple wavelength. That is, the non-linear interactions with the dominant wave assumed to be essential. (authors)

  11. Capillary electrophoretic determination of sulfite using the zone-passing technique of in-capillary derivatization.

    Science.gov (United States)

    Jankovskiene, G; Daunoravicius, Z; Padarauskas, A

    2001-11-16

    A new capillary electrophoretic (CE) method was developed for the simple and selective determination of sulfite. The proposed method is based on the in-capillary derivatization of sulfite with iodine using the zone-passing technique and direct UV detection of iodide formed. The optimal conditions for the separation and derivatization reaction were established by varying concentration of iodine, electrolyte pH and applied voltage. The optimised separations were carried out in 20 mmol l(-1) Tris-HCl electrolyte (pH 8.5) using direct UV detection at 214 nm. Experimental results showed that the injection of the iodine zone from anodic end of the capillary gives significantly better precision. Common UV absorbing anions such as Br-, l-, S2O3(2-), NO3-, NO2-, SCN- did not give any interferences. Valid calibration (r2=0.998) is demonstrated in the range 1 x 10(-5) - 8 x 10(-4) mol l(-1) of sulfite. The detection limit (SIN=3) was 2 x 10(-6) mol l(-1). The proposed system was applied to the determination of free sulfite in wines. The recovery tests established for wine samples were within the range 92-103%. The CE results were compared with those obtained by iodometric titration technique. PMID:11762765

  12. The Influence of Unconformities Along the Layer Interface on Capillary Barrier Flow

    Science.gov (United States)

    Wohnlich, S.; Dallery, M.; Lesón, M.; Bitomsky, K.

    2008-12-01

    Under unsaturated conditions the water flow in sediments is largely influenced by capillary forces. Especially if layers of fine grained sand overlay coarser layers of sand and gravel. The fine soil layer stores infiltrating water (capillary forces), acts like a drainage layer in sloping systems and thus is used to divert laterally the water under unsaturated conditions. This effect is used in waste technology as a barrier to downward flow. By far most of the present experiments with this respect were investigating undisturbed, straight construction of the interface between the two layers. Sedimentological unconformities in natural soils or uneven settlements of underlying waste are disturbing this distinct construction. These unconformities along the layer interface may change the flow pattern and cause vertical breakthrough. The experiments presented here are aimed to quantify the influence of interface discontinuities on the capillary flow. In the experimental set up a capillary layer (0.35 m sand) and capillary block (0.18 m gravel) were placed in an experimental tank of 6 m length, 1 m high, and 0.6 m width, with a slope of 11.3°. The tank is subdivided in 12 separately measurable drainage compartments, which enables the identification and quantification of local breakthrough. Inflow, outflow at all 14 segments, soil water tension (13 tensiometers), soil moisture (4 TDR probes) were automatically monitored. In addition tracers (NaCl and Amidorhodamine G) were used to visualize the flow pattern and determine hydraulic parameters. In a first set of experiments (3) the interface between sand and gravel were partially covered by a plastic membrane with variable openings. The second setup included two pillows filled with water, which were placed in the gravel during the construction each on the left and the right side of the tank, in a distance of 0.42 m from the upper end. In all setups the inflow rate was stepwise increased until reaching the lateral drainage

  13. Selective determination of cadmium(II) from divalent metal ions in environmental samples by capillary electrophoresis using in-capillary complexation with a lacunary Keggin-type [PW11O39]7- complex.

    Science.gov (United States)

    Himeno, Sadayuki; Kitano, Eri; Morishita, Kenta

    2007-08-01

    A novel capillary electrophoretic (CE) method, based on in-capillary complexation with [PW(11)O(39)](7-), was developed for the determination of cadmium(II) in natural water samples. When a sample solution is injected into a capillary containing 0.20 mM [PW(11)O(39)](7-) and 0.10 M malonate buffer (pH 3.0), the ternary Keggin-type complex, [P(Cd(II)W(11))O(39)](5-), which possesses high molar absorbtivities in the UV region, is formed in the capillary, and its migration toward the anode gives a well-defined migration peak in the electropherogram. An advantage of this method is that many divalent metal ions do not interfere. The proposed method was successfully applied to the determination of Cd(II) in environmental samples. The detection limits were 1 x 10(-7) and 5 x 10(-7) M for river-water and seawater samples, respectively (signal-to-noise ratio = 3). PMID:17690428

  14. Residual liquids saturation development during two and three phase flow under gravity in square capillaries at different temperatures

    International Nuclear Information System (INIS)

    Highlights: • Residual liquid saturations under gravity at different temperatures were analyzed. • If NT < 2.7E−2, residual oil saturation (Sor) was independent of viscous/gravity forces. • At T = 55 and 85 °C, the initial water saturation did not affect the amount of retained oil. • An empirical correlation for Sor was developed for free-fall gravity drainage. • This data will be useful in the assessment of thermal heavy-oil recovery applications. - Abstract: An experimental study on heavy oil with air (two phase flow) and water and air (three phase flow) at different temperatures was carried out in square capillaries under gravity drainage conditions. Fluid retention characteristics (in the corners of capillaries) were determined and evaluated using the trapping number (NT). In air–heavy oil systems, when NT < 2.7E−2, the residual oil saturation (Sor) was constant and equal at 55 and 85 °C. The Sor was controlled by capillary forces regardless of viscous and gravity forces, including free fall gravity drainage (FFGD). For higher NT, the Sor was a function of competition between gravity, viscous and capillary forces. The Sor was always higher at 85 °C compared to 55 °C for the same gas injection rate and the difference increased as the NT augmented. FFGD experiments demonstrated that heavy oil retention depended on the Bond number and increased linearly as the Bond number increased. In the three phase systems (air–heavy oil–water) the oil retention did not diminish with the presence of water, which was also constant for the entire interval of NT at 55 and 85 °C. High viscous forces originated from heavy oil were responsible for no change in the Sor. However, due to the water-wet nature of the capillary tubes, water was not completely swept. More Sor and residual water saturation were observed in air–water–heavy oil configuration, especially at 85 °C, due to the unfavorable viscosity ratio oil/water and the negative spreading

  15. Wood–water interactions

    DEFF Research Database (Denmark)

    Engelund, Emil Tang

    2011-01-01

    Predicting the performance of wood for decades ahead is important when using the material for structural purposes. The performance is closely related to the hierarchical material structure of wood and the dependent interaction with water in the structure. Accurately predicting wood performance...... therefore requires an understanding of material structure from molecular to macroscopic level as well as of the impact of water molecules. The objective of this work is to investigate the performance of wood in terms of mechanical response of the material and effect of water. To understand the latter, one...... must first know in which parts of the wood structure, water is located. If parts of the water in wood are held in capillaries in the wood structure, these water molecules interact with the material differently than those held within wood cell walls. In this study, the occurrence of capillary water in...

  16. Impact of Surface Roughness on Capillary Trapping Using 2D-Micromodel Visualization Experiments

    Science.gov (United States)

    Geistlinger, Helmut; Attaei-Dadavi, Iman; Vogel, Hans-Jörg

    2016-04-01

    Percolation theory, Water Resour Res, 51, doi:10.1002/2015WR017852. [2] H. Geistlinger, I. Ataei-Dadavi, and H.-J. Vogel (2016) Impact of Surface Roughness on Capillary Trapping Using 2D-Micromodel Visualization Experiments. Transport in Porous Med., in press.

  17. Guiding of charged particles through capillaries in insulating materials

    Science.gov (United States)

    Stolterfoht, Nikolaus; Yamazaki, Yasunori

    2016-04-01

    Studies of charged particle guiding through capillaries in insulating materials, performed during the last decade, are reviewed in a comprehensive manner. First, the principles of capillary guiding of slow highly charged ions are introduced describing the self-organized formation of charge patches. Basic quantities are defined, such as the guiding power characterizing a capillary. Challenges of the guiding experiments are pointed out. Then, experiments are described with emphasis on the guiding of highly charged ions in the keV energy range. Samples with an array of nanocapillaries as well as single macrocapillaries are treated. Emission profiles of transmitted ions are analyzed to establish scaling laws for the guiding angle, which quantifies the guiding power. Oscillations of the mean ion emission angle reveal the temporal dynamics of the charge patch formation. Next, experiments with ions of high (MeV) energies are focused on single tapered capillaries allowing for the production of a microbeam for various applications. Experiments concerning electrons are presented showing that apart from being elastically scattered these negative particles may enter into the capillary surface where they suffer energy losses. Finally, theoretical concepts of the capillary guiding are discussed. Simulations based on different charge transport methods clearly support the understanding of the guiding mechanisms. Altogether, capillary guiding involves several novel phenomena for which understanding have progressed far beyond their infancy.

  18. Extensional flow of low-viscosity fluids in capillary bridges formed by pulsed surface acoustic wave jetting

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharjee, P K; McDonnell, A G; Prabhakar, R; Yeo, L Y; Friend, J, E-mail: james.friend@monash.edu.au [MicroNanophysics Research Laboratory, Department of Mechanical and Aerospace Engineering, Monash University, Melbourne, VIC 3800 (Australia); Melbourne Centre for Nanofabrication, Melbourne, VIC 3800 (Australia)

    2011-02-15

    Forming capillary bridges of low-viscosity ({approx}<10 mPa s) fluids is difficult, making the study of their capillary-thinning behavior and the measurement of the fluid's extensional viscosity difficult as well. Current techniques require some time to form a liquid bridge from the stretching of a droplet. Rapidly stretching a liquid bridge using these methods can cause its breakup if the viscosity is too low. Stretching more slowly allows the bridge to thin and break up before a suitable bridge geometry can be established to provide reliable and accurate rheological data. Using a pulsed surface acoustic wave to eject a jet from a sessile droplet, a capillary bridge may be formed in about 7.5 ms, about seven times quicker than current methods. With this approach, capillary bridges may be formed from Newtonian and non-Newtonian fluids having much lower viscosities-water, 0.04% by weight solution of high-molecular-weight (7 MDa) polystyrene in dioctyl phthalate and 0.25% fibrinogen solution in demineralized water, for example. Details of the relatively simple system used to achieve these results are provided, as are experimental results indicating deviations from a Newtonian response by the low-viscosity non-Newtonian fluids used in our study.

  19. Measurement of capillary pressure in fuel cell diffusion media, micro-porous layers, catalyst layers, and interfaces

    Science.gov (United States)

    LaManna, Jacob M.; Bothe, James V.; Zhang, Feng Yuan; Mench, Matthew M.

    2014-12-01

    In this work, semi-empirical Leverett J-Function relationships relating capillary pressure and water saturation are experimentally derived for commercial and experimental polymer electrolyte fuel cell materials developed for automotive applications. Relationships were derived for Mitsubishi Rayon Corp. (MRC) U105 and General Motors (GM) experimental high tortuosity diffusion media (DM), the micro-porous layer (MPL), and the catalyst layer (CL). The standard Leverett J-Function under-predicted drainage curves for the DM at high saturation levels and significantly under-predicted the capillary pressure requirements for the MPL and CL across the entire saturation range. Composite structures were tested to understand interfacial effects for DM|MPL and MPL|CL. Each additional layer was found to superimpose its effects on capillary pressure onto the previous layers. The MPL formulation tested increased in porosity from a 136 nm peak average to a 153 nm peak average with increased surface porosity of the substrate. Additionally, small voids and pockets that accumulate liquid water were found to exist in the MPL|CL interface. The results of this work are useful for computational modelers seeking to enhance the resolution of their macroscopic multi-phase flow models which underestimate capillary pressure using the standard Leverett J-Function.

  20. Separation and quantification of cellulases and hemicellulases by capillary electrophoresis

    DEFF Research Database (Denmark)

    Jørgensen, Henning; Kutter, Jörg Peter; Olsson, Lisbeth

    2003-01-01

    . Current methods are limited in their ability to quantify all of these enzymes when all are present simultaneously in a mixture. Five different cellulases (two cellobiohydrolases and three endoglucanases) and one hemicellulase (endoxylanase) were separated using capillary electrophoresis (CE) in a fused...... silica capillary at pH values close to neutral. The improvement of the separation of these six proteins by the addition of alpha, omega-diaminoalkanes with chain lengths from three to seven carbon units was investigated. Dynamically coating the capillary with 1,3-diaminopropane resulted in separation of...

  1. Pepsin-modified chiral monolithic column for affinity capillary electrochromatography.

    Science.gov (United States)

    Hong, Tingting; Chi, Cuijie; Ji, Yibing

    2014-11-01

    Pepsin-modified affinity monolithic capillary electrochromatography, a novel microanalysis system, was developed by the covalent bonding of pepsin on silica monolith. The column was successfully applied in the chiral separation of (±)-nefopam. Furthermore, the electrochromatographic performance of the pepsin-functionalized monolith for enantiomeric analysis was evaluated in terms of protein content, pH of running buffer, sample volume, buffer concentration, applied voltage, and capillary temperature. The relative standard deviation (%RSD) values of retention time (intraday implied that the affinity monolith used in this research opens a new path of exploring particularly versatile class of enzymes to develop enzyme-modified affinity capillary monolith for enantioseparation. PMID:25146884

  2. An Amorphous Network Model for Capillary Flow and Dispersion in a Partially Saturated Porous Medium

    Science.gov (United States)

    Simmons, C. S.; Rockhold, M. L.

    2013-12-01

    Network models of capillary flow are commonly used to represent conduction of fluids at pore scales. Typically, a flow system is described by a regular geometric lattice of interconnected tubes. Tubes constitute the pore throats, while connection junctions (nodes) are pore bodies. Such conceptualization of the geometry, however, is questionable for the pore scale, where irregularity clearly prevails, although prior published models using a regular lattice have demonstrated successful descriptions of the flow in the bulk medium. Here a network is allowed to be amorphous, and is not subject to any particular lattice structure. Few network flow models have treated partially saturated or even multiphase conditions. The research trend is toward using capillary tubes with triangular or square cross sections that have corners and always retain some fluid by capillarity when drained. In contrast, this model uses only circular capillaries, whose filled state is controlled by a capillary pressure rule for the junctions. The rule determines which capillary participate in the flow under an imposed matric potential gradient during steady flow conditions. Poiseuille's Law and Laplace equation are used to describe flow and water retention in the capillary units of the model. A modified conjugate gradient solution for steady flow that tracks which capillary in an amorphous network contribute to fluid conduction was devised for partially saturated conditions. The model thus retains the features of classical capillary models for determining hydraulic flow properties under unsaturated conditions based on distribution of non-interacting tubes, but now accounts for flow exchange at junctions. Continuity of the flow balance at every junction is solved simultaneously. The effective water retention relationship and unsaturated permeability are evaluated for an extensive enough network to represent a small bulk sample of porous medium. The model is applied for both a hypothetically

  3. The Role of Capillary Barrier in Reducing Moisture Content on Waste Packages

    International Nuclear Information System (INIS)

    Assessment of the performance of engineered capillary barriers at the potential Yucca Mountain nuclear waste repository site, in which 1.67-m-diameter waste packages are to be emplaced in 5-m-diameter tunnels according to current design, brings up aspects not commonly considered in more typical applications of capillary barriers (e.g., near-surface landfills). Engineered capillary barriers typically consist of two layers of granular materials with a sloping interface, in which the contrast in capillarity between the layers keeps infiltrating water in the upper layer. One issue is the effect of thermohydrologic processes that would occur at elevated repository temperatures (and temperature gradients). For example, backfill materials may be altered from that of the as-placed material by the hydrothermal regime imposed by the emplacement of waste in the repository, changing hydrologic properties in a way that degrades the performance of the barrier. A reduction of permeability in the upper layer might diminish the capacity of the upper layer to divert incoming seepage or to cause a ''vapor lid'' whereby buoyant vapor flow would be trapped, then condense and drain onto waste packages. Other concerns are the result of highly spatially and temporally variable seepage distribution and the very limited spatial scale available for flow attenuation and diversion

  4. [Fractal characteristics of capillary finger flow for NAPLs infiltrated in porous media].

    Science.gov (United States)

    Li, Hui-Ying; Du, Xiao-Ming; Yang, Bin; Wu, Bin; Xu, Zhu; Shi, Yi; Fang, Ji-Dun; Li, Fa-Sheng

    2013-10-01

    Non-aqueous phase liquids (NAPLs) like petroleum hydrocarbons and chlorinated solvents have resulted in contamination of soils and ground water, which aroused widespread concern. It's quite important to delineate pollution area for remediation according to different soil types with pollutants properties in consideration. In this paper, a two-dimension visual sand box apparatus was constructed, with four typical NAPLs selected for infiltration experiments conducted in initially dry porous media. The main driving force was identified and fingering patterns were compared. The fractal dimension was used to give quantitative description. The present work indicates that the main driving force was capillary forces and the mechanism was the capillary fingering. The fingers varied from skeletal patterns to fleshy patterns and the infiltration area increased when the capillary number and the bond number decreased for NAPLs with the same level of viscosity. The high viscous force resulted in larger finger width and infiltration area. The same change between fluids happened in finer media. Fractal dimensions were positively correlated with the finger width and infiltration area, which is helpful in the pollution area characterization. PMID:24364331

  5. Stability of capillary-gravity interfacial waves between two bounded fluids

    Science.gov (United States)

    Christodoulides, Paul; Dias, Frédéric

    1995-12-01

    Two-dimensional periodic capillary-gravity waves at the interface between two bounded fluids of different densities are considered. Based on a variational formulation, the relation between wave frequency and wave amplitude is obtained through a weakly nonlinear analysis. All classes of space-periodic waves are studied: traveling and standing waves as well as a degenerate class of mixed waves. As opposed to water waves, mixed interfacial waves exist even for pure gravity waves. The stability of traveling and standing waves with respect to three-dimensional modulations is then studied. By using the method of multiple scales, Davey-Stewartson-type equations are obtained. A detailed stability analysis is performed in three cases: pure gravity waves, capillary-gravity waves when one layer is infinitely deep, and capillary-gravity waves when both layers are infinitely deep. The main results for oblique (i.e., combined longitudinal and transverse) modulations reveal a mostly stabilizing effect of the density ratio for traveling waves and a destabilizing effect for standing waves.

  6. Use of Spray Adhesives for the Manufacture of 3-D Capillary Origami Microstructures

    Science.gov (United States)

    de Los Reyes, Mithi

    2011-10-01

    The method of ``capillary origami''---using the surface tension of an evaporating water droplet to fold a flexible membrane into a 3-D polyhedron, as investigated by Py et al.---has shown promise as a way to create fully 3-D microstructures. However, the origami re-opens past a critical evaporation point, and previous attempts to prevent this re-opening have proven to be expensive and time-consuming. We therefore investigated the use of various spray adhesives in keeping these origami microstructures closed. Three characteristics were measured: efficiency, tackiness, and strength of the adhesive. Measurements of these three characteristics point to 3M Super 77 Spray Adhesive as an optimal adhesive for spraying microstructures. Furthermore, we designed a new method to measure adhesive strength by using an analytical balance to measure force applied by a micrometer to a microstructure. We also developed novel procedures to create uniformly-sized microstructures and to accelerate the folding process, all of which improve upon the original capillary origami method. These novel procedures, combined with measurements that indicate 3M Super 77 as an optimum adhesive, suggest a potential method for the mass-production of truly 3-D microstructures. Py, Charlotte, et al. ``Capillary origami: Spontaneous wrapping of a droplet with an elastic sheet.'' Physical Review Letters. 98.156103 (2007)

  7. Capillary rise of oil in an aqueous foam

    Science.gov (United States)

    Piroird, Keyvan; Lorenceau, Élise

    2012-11-01

    Oil is usually known as an anti-foaming agent. Yet, it has been shown that oil droplets present in the foaming solution can have the opposite effect and stabilize a foam when unable to cross the air/water interface. In these previous studies, oil is first emulsified and then mixed with air to generate a foam. In this work, we report experiments where an aqueous foam is put in direct contact with a large oil drop. With the appropriate choice of oil and surfactants, oil spontaneously invades the liquid network of the foam without damaging it. We study the dynamics of penetration at the scale of a single Plateau border, that acts as a ``liquid capillary tube'' in which oil flows in an unbroken stream. At the end of the experiment, a long and stable cylinder of oil is formed in the Plateau border. This cylinder breaks up into droplets when, following a rearrangement, oil is transferred from the Plateau border to a soap film.

  8. Capillary gas chromatography of metal chelates of diethyl dithiocarbamates

    Energy Technology Data Exchange (ETDEWEB)

    Arain, M.A.; Bhanger, M.I. [Center of Excellence in Analytical Chemistry (Pakistan); Khuhawar, M.Y. [M.A. Kazi Inst. of Chemistry, Univ. of Sindh, Jamshoro (Pakistan)

    2002-03-01

    Capillary GC of metal chelates of diethyl dithiocarbamate (DDTC) was examined on a methylsilicone DB-1 column, (25 meter, 0.2 mm. i.d) with a film thickness of 0.25 {mu}m. Elution was carried out at the initial column temperature of 180 C and programmed at 5 C min{sup -1} to 260 C. Detection was by FID or ECD. Symmetrical peaks with bse line separation were obtained with the metal chelates of copper(II), nickel(II), cobalt(III), manganese(II) and chromium(III). The ECD gave better sensitivity than the FID with a linear calibration range of 5 - 50 {mu}g mL{sup -1} and detection limits 2.0 - 6.0 {mu}g mL{sup -1}, corresponding to 111 - 333 pg of metal ion reaching the detector. The method was applied to the determination of metal ions in water and pharmaceutical preparations with a coefficient of variation (CV) within 4.0%. When compared with a standard flame AAS method the results revealed no significant difference. (orig.)

  9. Stability of capillary surfaces supported by a helical wire

    CERN Document Server

    Bernate, Jorge A

    2012-01-01

    In this fluid dynamics video, we report on experiments of large aspect ratio capillary surfaces supported by a helical wire. These open channels are potentially useful for fluid management at low Bond numbers. The experiments were performed in a Plateau tank, injecting 2-fluorotoluene into distilled water, density matched at 26.5 $^{o}$C. Extension springs with a nominal diameter of 0.24 inches and with a wire diameter of 0.018 inches were used. At small extensions, liquid can be injected into the spring from one side. The injected free-ended liquid columns are stable. Volume-constrained stability can be studied after injecting from both sides until coalescence. Stable states exist between lower and upper volume stability limits. The low volume instability is manifested by the growth of a neck that eventually breaks. The breakage sends a wave front; the interface ahead of the front is static while the interface behind the front undergoes oscillations. These oscillations eventually dampen as the free-ends retr...

  10. In situ observation and analysis of ultrasonic capillary effect in molten aluminium.

    Science.gov (United States)

    Tzanakis, I; Xu, W W; Eskin, D G; Lee, P D; Kotsovinos, N

    2015-11-01

    An in situ synchrotron radiographic study of a molten Al-10 wt% Cu alloy under the influence of an external ultrasonic field was carried out using the Diamond-Manchester Branchline pink X-ray imaging at the Diamond Light Source in UK. A bespoke test rig was used, consisting of an acoustic transducer with a titanium sonotrode coupled with a PID-controlled resistance furnace. An ultrasonic frequency of 30 kHz, with a peak to peak amplitude at 140 microns, was used, producing a pressure output of 16.9 MPa at the radiation surface of the 1-mm diameter sonotrode. This allowed quantification of not only the cavitation bubble formation and collapse, but there was also evidence of the previously hypothesised ultrasonic capillary effect (UCE), providing the first direct observations of this phenomenon in a molten metallic alloy. This was achieved by quantifying the re-filling of a pre-existing groove in the shape of a tube (which acted as a micro-capillary channel) formed by the oxide envelope of the liquid sample. Analytical solutions of the flow suggest that the filling process, which took place in very small timescales, was related to micro-jetting from the collapsing cavitation bubbles. In addition, a secondary mechanism of liquid penetration through the groove, which is related with the density distribution of the oxides inside the groove, and practically to the filtration of aluminium melt from oxides, was revealed. The observation of the almost instantaneous re-filling of a micro-capillary channel with the metallic melt supports the hypothesised sono-capillary effect in technologically important liquids other than water, like metallic alloys with substantially higher surface tension and density. PMID:26186822

  11. Filling kinetics of liquids in nanochannels as narrow as 27 nm by capillary force.

    Science.gov (United States)

    Han, Anpan; Mondin, Giampietro; Hegelbach, Nicole G; de Rooij, Nicolaas F; Staufer, Urs

    2006-01-01

    We report the filling kinetics of different liquids in nanofabricated capillaries with rectangular cross-section by capillary force. Three sets of channels with different geometry were employed for the experiments. The smallest dimension of the channel cross-section was respectively 27, 50, and 73 nm. Ethanol, isopropanol, water and binary mixtures of ethanol and water spontaneously filled nanochannels with inner walls exposing silanol groups. For all the liquids the position of the moving liquid meniscus was observed to be proportional to the square root of time, which is in accordance with the classical Washburn kinetics. The velocity of the meniscus decreased both with the dimension of the channel and the ratio between the surface tension and the viscosity. In the case of water, air-bubbles were spontaneously trapped as channels were filled. For a binary mixture of 40% ethanol and water, no trapping of air was observed anymore. The filling rate was higher than expected, which also corresponds to the dynamic contact angle for the mixture being lower than that of pure ethanol. Nanochannels and porous materials share many physicochemical properties, e.g., the comparable pores size and extremely high surface to volume ratio. These similarities suggest that our nanochannels could be used as an idealized model to study mass transport mechanisms in systems where surface phenomena dominate. PMID:16023663

  12. Development of tracking detectors based on capillaries with liquid scintillator

    International Nuclear Information System (INIS)

    Capillaries with a liquid scintillator used for high resolution tracking detectors have been investigated. The highest scintillation efficiency, 1.5 times higher than that of a standard polystyrene scintillator, has been attained for the solution of 1-methylnaphtalene with pyrasoline type dye MDP. The time properties of this liquid scintillator and locality of light emission have been studied. Light attenuations in quartz capillaries of different diameters have been measured. For the optimal concentration of MDP the attenuation lengths for capillaries of 30 and 60 μm diameter were 41 cm and 53 cm, respectively. For high resolution tracking detectors capillaries with a liquid scintillator are quite competitive with plastic fibres. 26 refs.; 7 figs

  13. Improved Refrigerant Characteristics Flow Predictions in Adiabatic Capillary Tube

    Directory of Open Access Journals (Sweden)

    Shodiya Sulaimon

    2012-07-01

    Full Text Available This study presents improved refrigerant characteristics flow predictions using homogenous flow model in adiabatic capillary tube, used in small vapor compression refrigeration system. The model is based on fundamental equations of mass, momentum and energy. In order to improve the flow predictions, the inception of vaporization in the capillary tube is determined by evaluating initial vapor quality using enthalpy equation of refrigerant at saturation point and the inlet entrance effect of the capillary tube is also accounted for. Comparing this model with experimental data from open literature showed a reasonable agreement. Further comparison of this new model with earlier model of Bansal showed that the present model could be use to improve the performance predictions of refrigerant flow in adiabatic capillary tube.

  14. Targeted Functionalization of Nanoparticle Thin Films via Capillary Condensation

    KAUST Repository

    Gemici, Zekeriyya

    2009-03-11

    Capillary condensation, an often undesired natural phenomenon in nanoporous materials, was used advantageously as a universal functionalization strategy in nanoparticle thin films assembled layer-by-layer. Judicious choice of nanoparticle (and therefore pore) size allowed targeted capillary condensation of chemical vapors of both hydrophilic and hydrophobic molecules across film thickness. Heterostructured thin films with modulated refractive index profiles produced in this manner exhibited broadband antireflection properties with an average reflectance over the visible region of the spectrum of only 0.4%. Capillary condensation was also used to modify surface chemistry and surface energy. Photosensitive capillary-condensates were UV-cross-linked in situ. Undesired adventitious condensation of humidity could be avoided by condensation of hydrophobic materials such as poly(dimethyl siloxane). © 2009 American Chemical Society.

  15. Improved dual photometric-contactless conductometric detector for capillary electrophoresis

    International Nuclear Information System (INIS)

    A new design of a dual, UV photometric - contactless conductometric detector is described. The separation capillary with an optical window created is pressed onto two semitubular electrodes, 3 mm wide and 2 mm apart. The electrodes form the detection cell of the contactless conductometric detector. An optical fiber, placed in the gap between the conductometric electrodes, brings radiation from the source. The radiation that passes through the separation capillary is recorded by a large-area photodiode. The optical fiber and the photodiode operate the photometric cell which is between the conductometric electrodes. The detector thus permits simultaneous photometric and conductometric detection in the same place of the capillary, while exchanging of the separation capillary is easy and without effect on the detector geometry and performance

  16. Optical emission spectroscopy observations of fast pulsed capillary discharge plasmas

    Science.gov (United States)

    Avaria, G.; Ruiz, M.; Guzmán, F.; Favre, M.; Wyndham, E. S.; Chuaqui, H.; Bhuyan, H.

    2014-05-01

    We present time resolved optical emission spectroscopic (OES) observations of a low energy, pulsed capillary discharage (PCD). The optical emission from the capillary plasma and plasma jets emitted from the capillary volume was recorded with with a SpectraPro 275 spectrograph, fitted with a MCP gated OMA system, with 15 ns time resolution. The discharge was operated with different gases, including argon, nitrogen, hydrogen and methane, in a repetitive pulsed discharge mode at 10-50 Hz, with, 10-12 kV pulses applied at the cathode side. The time evolution of the electron density was measured using Stark broadening of the Hβ line. Several features of the capillary plasma dynamics, such as ionization growth, wall effects and plasma jet evolution, are inferred from the time evolution of the optical emission.

  17. High Performance Wafer-Based Capillary Electrochromatography Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Los Gatos Research proposes to develop wafer-based capillary electrochromatography for lab-on-a-chip (LOC) applications. These microfluidic devices will be...

  18. Plasma Dynamics of Capillary Discharges for the BELLA project

    Science.gov (United States)

    Stoltz, Peter; Hakim, Ammar; Loverich, John; Fillmore, David; Johnson, Jeffrey; Geddes, Cameron; Esarey, Eric; Mittelberger, Daniel; Bulanov, Stepan; Gonsalves, Anthony; Leemans, Wim

    2010-11-01

    Capillary discharges to form a meter-scale plasma waveguide are important for 10 GeV scale laser plasma accelerator experiments on the BELLA laser in progress at Lawrence Berkeley National Laboratory. We present simulation results of capillary plasma properties, including radial density and temperature profiles, using the Nautilus code. An effect known to play a dominant role is the transfer of heat from the plasma to the capillary wall. We present benchmark results for heat transfer modeling with Nautilus in the regime of interest to capillary discharges. We also discuss the relative importance of diffusion, Ohm's law, and applied solenoidal fields on the radial profiles needed for experiments. For instance, some previous models estimate applied solenoidal fields could increase on-axis temperatures by roughly a factor of two, and we compare with these estimates. Finally, we compare radial profile results with other simulation results and with recent measurements made at LBNL.

  19. A capillary based chemiluminscent multi-target immunoassay.

    Science.gov (United States)

    Cao, Yuan-Cheng

    2015-05-01

    Renewed interest in capillary format immunoassays has lead to increasingly costly and complex approaches to preparation and readout. This study describes a simple multi-target method based on a capillary platform using horseradish peroxidase (HRP) labelled IgG to visualize an antibody antigen complex. When goat-anti-human IgG was employed as the probe and human IgG as target, the system allowed detection of target to less than 1 ng/mL using a standard detection approach. The capillaries were read visually or with a commercial grade CCD camera. Multi-target detection was demonstrated using a model system of rat-anti-mouse, goat-anti-human and mouse-anti-rat IgG. These probes were encoded to different locations in the capillary, providing a simple inexpensive approach to achieve multi-target assays. PMID:25731812

  20. Pulmonary Surfactant Surface Tension Influences Alveolar Capillary Shape and Oxygenation

    OpenAIRE

    Ikegami, Machiko; Weaver, Timothy E.; Grant, Shawn N.; Whitsett, Jeffrey A.

    2009-01-01

    Alveolar capillaries are located in close proximity to the alveolar epithelium and beneath the surfactant film. We hypothesized that the shape of alveolar capillaries and accompanying oxygenation are influenced by surfactant surface tension in the alveolus. To prove our hypothesis, surfactant surface tension was regulated by conditional expression of surfactant protein (SP)-B in Sftpb−/− mice, thereby inhibiting surface tension–lowering properties of surfactant in vivo within 24 hours after d...

  1. Spatiotemporal phase-matching in capillary high-harmonic generation

    OpenAIRE

    Rogers, Edward T.F.; Stebbings, Sarah L; de Paula, Ana M.; Froud, Christopher A.; Praeger, Matthew; Mills, Benjamin; Grant-Jacob, James; Brocklesby, William S; Frey, Jeremy G

    2012-01-01

    We present a simple phase-matching model that takes into account the full spatiotemporal nature of capillary high-harmonic generation. Spectra predicted from the model are compared to experimental results for a number of gases and are shown to reproduce the spectral envelope of experimentally generated harmonics. The model demonstrates that an ionization-induced phase mismatch is limiting the energy of the generated harmonics in current capillary high-harmonic generation experiments. The succ...

  2. Optimized photonic crystal fibers supporting efficient capillary electrophoresis

    Science.gov (United States)

    Calcerrada, M.; García-Ruiz, C.; Roy, P.; Gonzalez-Herraez, M.

    2013-05-01

    In this paper we present preliminary results on the use of Photonic Crystal Fibers (PCFs) in a conventional capillary electrophoresis system to separate and detect fluorescent species. PCFs show interesting advantages over conventional capillaries for this application, including larger surface-to-volume ratio and potential for higher resolution with comparable sensitivity. Our results illustrate some of these advantages, and we point out the need for stringent tolerances in the fabrication of specific PCFs for this application.

  3. Modified monolithic silica capillary for preconcentration of catecholamines

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Preconcentration of catecholamines by the modified monolithic silica in the capillary was investigated in this study. In order to achieve a microchip-based method for determining catecholamines in the saliva,the monolithic silica was fabricated in the capillary and the monolithic silica was chemically modified by on-column reaction with phenylboronate. Different modified methods were compared. The concentration conditions were optimized. This study indicates the applicability of the modified monolithic sili...

  4. Field-portable Capillary Electrophoresis Instrument with Conductivity Detection

    International Nuclear Information System (INIS)

    In this paper a novel capillary electrophoresis chip (CEC) is presented with integrated platinum electrodes and simplified conductivity detector. CEC is fabricated by the method of mechanical modification with probe on organic glass. Capillary electrophoresis chip can rapidly completed ion separation by simulation of concentration distribution and zone-broadening. Detection circuit is simple which can detect pA order current. This system has those advantages such as small volume, low power consumption and linearity, and well suit for field analysis

  5. Laser-based ultraviolet absorption detection in capillary electrophoresis

    International Nuclear Information System (INIS)

    Laser-based UV absorption in capillary electrophoresis is demonstrated. The use of vacuum photodiodes and an all-electronic noise canceller provides adequate baseline stability despite the large inherent intensity noise in UV lasers. A 4-fold improvement in the detection limit is achieved in comparison to that of commercial instruments. The main advantage here is the better optical coupling with small capillary tubes, maximizing the available optical pathlength for absorption

  6. Capillary Electrophoresis as a Fundamental Probe of Polymer Dynamics

    OpenAIRE

    Phillies, George D. J.

    2011-01-01

    Capillary electrophoresis has long been been recognized as a powerful analytic tool. Here it is demonstrated that the same capillary electrophoretic experiments also reveal dynamic properties of the polymer solutions being used as the support medium. The dependence of the electrophoretic mobility on the size of the probe and the properties of the matrix polymers shows a unity of behavior between electrophoresis and other methods of studying polymer properties.

  7. Fabrication and Visualization of Capillary Bridges in Slit Pore Geometry

    OpenAIRE

    Broesch, David J.; Frechette, Joelle

    2014-01-01

    A procedure for creating and imaging capillary bridges in slit-pore geometry is presented. High aspect ratio hydrophobic pillars are fabricated and functionalized to render their top surfaces hydrophilic. The combination of a physical feature (the pillar) with a chemical boundary (the hydrophilic film on the top of the pillar) provides both a physical and chemical heterogeneity that pins the triple contact line, a necessary feature to create stable long but narrow capillary bridges. The subst...

  8. Immunomodulation potential of Artemisia capillaris extract in rat splenocytes

    OpenAIRE

    Hyun-ji Lee; Tamanna Zerin; Young-hee kim; byung-eui lee; Ho-yeon Song

    2013-01-01

    The extract of Artemisia capillaris has been used as a traditional medicine for hepatitis or bilious disorder, and some recent studies have revealed its antimicrobial, antioxidant, antiobesity, anticarcinogenic, antioxidant, and anti-inflammatory potential. The current study was designed to evaluate the potential immunomodulatory effects of A. capillaris methanol extract on quiescent- and concanavalin A (Con A)-stimulated rat splenocytes. Proliferation of splenocytes was enhanced in response...

  9. Potential of polyE-323 coated capillaries for capillary electrophoresis of lipids.

    Science.gov (United States)

    Martma, Kert; Lindenburg, Petrus W; Habicht, Kaia-Liisa; Vulla, Kaspar; Resik, Kristiin; Kuut, Gunnar; Shimmo, Ruth

    2013-11-22

    In this note the feasibility of a polyamine-based capillary coating, polyE-323, for capillary electrophoresis (CE) of lipids is explored. PolyE-323 has previously been demonstrated to be suitable to suppress analyte-wall interaction of proteins in CE. However, the full applicability range of polyE-323 has not been exploited yet and it might be useful in the analysis of hydrophobic analytes, such as lipids. In this study, the stability of polyE-323 when using highly organic background electrolytes (BGEs), which are needed to solubilize the lipid analytes, was studied. For this, we used three different lipid samples: sphingomyelin, cardiolipin and a lipid extract from a cell culture. The highly organic BGEs that were used in this study consisted of 94.5% of organic solvents and 5.5% of an aqueous buffer. First, the influence of pure acetonitrile, methanol, propylene carbonate, isopropanol and chloroform on the polyE-323 coating was investigated. Then BGEs were developed and tested, using sphingomyelin and cardiolipin as test analytes in CE-UV experiments. After establishing the best BGEs (in terms of analysis time and repeatability) by CE-UV, sphingomyelin was used as a test analyte to demonstrate that method was also suitable for CE with mass-spectrometry detection (CE-MS). The LOD of sphingomyelin was estimated to be 100 nM and its migration time repeatability was 1.3%. The CE-MS analysis was further applied on a lipid extract obtained from human glioblastoma cells, which resulted in the separation and detection of a multitude of putative lipids. The results of our feasibility study indicate that CE systems based on polyE-323 coated capillaries and highly organic BGEs are promising for fast electromigration-based analysis of lipids. PMID:24011728

  10. Attractions between charged colloids at water interfaces

    OpenAIRE

    Oettel, M.; Dominguez, A; Dietrich, S.

    2005-01-01

    The effective potential between charged colloids trapped at water interfaces is analyzed. It consists of a repulsive electrostatic and an attractive capillary part which asymptotically both show dipole--like behavior. For sufficiently large colloid charges, the capillary attraction dominates at large separations. The total effective potential exhibits a minimum at intermediate separations if the Debye screening length of water and the colloid radius are of comparable size.

  11. Fabricating PFPE Membranes for Capillary Electrophoresis

    Science.gov (United States)

    Lee, Michael C.; Willis, Peter A.; Greer, Frank; Rolland, Jason

    2009-01-01

    A process has been developed for fabricating perfluoropolyether (PFPE) membranes that contain microscopic holes of precise sizes at precise locations. The membranes are to be incorporated into laboratory-on-a-chip microfluidic devices to be used in performing capillary electrophoresis. The present process is a modified version of part of the process, described in the immediately preceding article, that includes a step in which a liquid PFPE layer is cured into solid (membrane) form by use of ultraviolet light. In the present process, one exploits the fact that by masking some locations to prevent exposure to ultraviolet light, one can prevent curing of the PFPE in those locations. The uncured PFPE can be washed away from those locations in the subsequent release and cleaning steps. Thus, holes are formed in the membrane in those locations. The most straightforward way to implement the modification is to use, during the ultraviolet-curing step, an ultraviolet photomask similar to the photomasks used in fabricating microelectronic devices. In lieu of such a photomask, one could use a mask made of any patternable ultraviolet-absorbing material (for example, an ink or a photoresist).

  12. Strongly nonlinear waves in capillary electrophoresis

    Science.gov (United States)

    Chen, Zhen; Ghosal, Sandip

    2012-05-01

    In capillary electrophoresis, sample ions migrate along a microcapillary filled with a background electrolyte under the influence of an applied electric field. If the sample concentration is sufficiently high, the electrical conductivity in the sample zone could differ significantly from the background. Under such conditions, the local migration velocity of sample ions becomes concentration-dependent, resulting in a nonlinear wave that exhibits shocklike features. If the nonlinearity is weak, the sample concentration profile, under certain simplifying assumptions, can be shown to obey Burgers’ equation [Ghosal and Chen, Bull. Math. Biol.BMTBAP0092-824010.1007/s11538-010-9527-2 72, 2047 (2010)], which has an exact analytical solution for arbitrary initial condition. In this paper, we use a numerical method to study the problem in the more general case where the sample concentration is not small in comparison to the concentration of background ions. In the case of low concentrations, the numerical results agree with the weakly nonlinear theory presented earlier, but at high concentrations, the wave evolves in a way that is qualitatively different.

  13. Principles of Micellar Electrokinetic Capillary Chromatography Applied in Pharmaceutical Analysis

    Directory of Open Access Journals (Sweden)

    Árpád Gyéresi

    2013-02-01

    Full Text Available Since its introduction capillary electrophoresis has shown great potential in areas where electrophoretic techniques have rarely been used before, including here the analysis of pharmaceutical substances. The large majority of pharmaceutical substances are neutral from electrophoretic point of view, consequently separations by the classic capillary zone electrophoresis; where separation is based on the differences between the own electrophoretic mobilities of the analytes; are hard to achieve. Micellar electrokinetic capillary chromatography, a hybrid method that combines chromatographic and electrophoretic separation principles, extends the applicability of capillary electrophoretic methods to neutral analytes. In micellar electrokinetic capillary chromatography, surfactants are added to the buffer solution in concentration above their critical micellar concentrations, consequently micelles are formed; micelles that undergo electrophoretic migration like any other charged particle. The separation is based on the differential partitioning of an analyte between the two-phase system: the mobile aqueous phase and micellar pseudostationary phase. The present paper aims to summarize the basic aspects regarding separation principles and practical applications of micellar electrokinetic capillary chromatography, with particular attention to those relevant in pharmaceutical analysis.

  14. Conductivity detection for conventional and miniaturised capillary electrophoresis systems.

    Science.gov (United States)

    Guijt, Rosanne M; Evenhuis, Christopher J; Macka, Miroslav; Haddad, Paul R

    2004-12-01

    Since the introduction of capillary electrophoresis (CE), conductivity detection has been an attractive means of detection. No additional chemical properties are required for detection, and no loss in sensitivity is expected when miniaturising the detector to scale with narrow-bore capillaries or even to the microchip format. Integration of conductivity and CE, however, involves a challenging combination of engineering issues. In conductivity detection the resistance of the solution is most frequently measured in an alternating current (AC) circuit. The influence of capacitors both in series and in parallel with the solution resistance should be minimised during conductivity measurements. For contact conductivity measurements, the positioning and alignment of the detection electrodes is crucial. A contact conductivity detector for CE has been commercially available, but was withdrawn from the market. Microfabrication technology enables integration and precise alignment of electrodes, resulting in the popularity of conductivity detection in microfluidic devices. In contactless conductivity detection, the alignment of the electrodes with respect to the capillary is less crucial. Contactless conductivity detection (CCD) was introduced in capillary CE, and similar electronics have been applied for CCD using planar electrodes in microfluidic devices. A contactless conductivity detector for capillaries has been commercialised recently. In this review, different approaches towards conductivity detection in capillaries and chip-based CE are discussed. In contrast to previous reviews, the focus of the present review is on the technological developments and challenges in conductivity detection in CE. PMID:15597418

  15. Temperature control of ion guiding through tapered capillaries

    Energy Technology Data Exchange (ETDEWEB)

    Gruber, Elisabeth, E-mail: egruber@iap.tuwien.ac.at [Institute of Applied Physics, TU Wien – Vienna University of Technology, 1040 Vienna (Austria); Stolterfoht, Nikolaus [Helmholtz-Zentrum Berlin für Materialien und Energie, D-14109 Berlin (Germany); Allinger, Peter; Wampl, Stefan [Institute of Applied Physics, TU Wien – Vienna University of Technology, 1040 Vienna (Austria); Wang, Yuyu [Institute of Applied Physics, TU Wien – Vienna University of Technology, 1040 Vienna (Austria); Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, Gansu (China); Simon, Marius J. [Labor für Ionenstrahlphysik, ETH Zürich, 8093 Zürich (Switzerland); Aumayr, Friedrich, E-mail: aumayr@iap.tuwien.ac.at [Institute of Applied Physics, TU Wien – Vienna University of Technology, 1040 Vienna (Austria)

    2014-12-01

    We investigate the guiding of Ar{sup 7+} ions (kinetic energy of 4.5 keV) through a single macroscopic tapered glass capillary of conical shape as a function of capillary tilt angle with respect to the incident ion beam direction. At room temperature a minimum in the transmitted ion intensity appears around the forward direction, which was previously observed and interpreted by a blocking of the transmission by repulsive Coulomb forces due to a uniformly charged ring shaped region in the centre part of the capillary. By heating the tapered capillary to temperatures around 100 °C and thus drastically increasing the electrical conductivity of the capillary material we no longer observe a minimum in the transmission curve but the transmission curve now has its maximum in forward direction. Since the maximum transmission at high temperature in forward direction is still smaller than the minimum in transmitted intensity at room temperature, we conclude that even at room temperature and in forward direction the focusing effect due to guiding is dominant and only partially weakened by blocking. Our experimental results are well reproduced in simulations using a theoretical model originally developed for straight nano-capillaries.

  16. A Fractal Model for Capillary Pressure of Porous Media

    Directory of Open Access Journals (Sweden)

    Boqi Xiao

    2013-06-01

    Full Text Available Capillary pressure is a basic parameter in the study of the behavior of porous media containing two or more immiscible fluid phases. In this study, the capillary pressure of porous media is predicted based on based on fractal property of pore in porous media. The formula of calculating the capillary pressure of porous media is given. The capillary pressure of porous media is expressed as a function of porosity, fractal dimension of pore and saturation. Based on the parametric effect analysis, we conclude that the capillary pressure of porous media is negatively correlated with the porosity and saturation. Besides, it is shown that the capillary pressure of unsaturated porous media decreases with the increase of saturation. No additional empirical constant is introduced. This model contains less empirical constants than the conventional correlations. The model predictions are compared with the existing experimental data and good agreement between the model predictions and experimental data is found. The validity of the present fractal model is thus verified.

  17. Fabrication and visualization of capillary bridges in slit pore geometry.

    Science.gov (United States)

    Broesch, David J; Frechette, Joelle

    2014-01-01

    A procedure for creating and imaging capillary bridges in slit-pore geometry is presented. High aspect ratio hydrophobic pillars are fabricated and functionalized to render their top surfaces hydrophilic. The combination of a physical feature (the pillar) with a chemical boundary (the hydrophilic film on the top of the pillar) provides both a physical and chemical heterogeneity that pins the triple contact line, a necessary feature to create stable long but narrow capillary bridges. The substrates with the pillars are attached to glass slides and secured into custom holders. The holders are then mounted onto four axis microstages and positioned such that the pillars are parallel and facing each other. The capillary bridges are formed by introducing a fluid in the gap between the two substrates once the separation between the facing pillars has been reduced to a few hundred micrometers. The custom microstage is then employed to vary the height of the capillary bridge. A CCD camera is positioned to image either the length or the width of the capillary bridge to characterize the morphology of the fluid interface. Pillars with widths down to 250 µm and lengths up to 70 mm were fabricated with this method, leading to capillary bridges with aspect ratios (length/width) of over 100(1). PMID:24457446

  18. Experimental study of heterogeneity-induced capillary trapping in the context of leakage from geologic carbon sequestration sites

    Science.gov (United States)

    Liang, B.; Clarens, A. F.

    2014-12-01

    Leakage of CO2 from geologic carbon sequestration sites could undermine the long-term goal of reducing emissions to the atmosphere. Despite this, leakage processes, especially the vertical transport of gases through geologic formations overlaying target repositories, are poorly characterized. The goal of this work was to experimentally assess how sub-basin scale heterogeneity in overlaying formations could reduce CO2 leakage. High-pressure columns packed with sand and glass beads of different sizes were used to create a capillary barrier, which is an analog of low-permeability inter-beds. Transport of the resulting plume was recorded in real time using electrical resistivity. The effect of pressure, temperature, permeability, surface wettability, and CO2 flow rate were all assessed. Real-time monitoring and quantification of CO2 saturation suggests that capillary heterogeneity trapping is primarily controlled by permeability contrast, pressure, temperature and water/CO2 wettability on mineral surfaces. The amount of trapping was considerably enhanced when permeability contrasted increased, showing a good agreement with equilibrium capillary pressure - saturation analysis in the literature. Temperature and pressure controlled experiments demonstrated the sensitivity of capillary trapping to geothermal and pressure gradient. Wettability alterations also increased initial trapping when more CO2-philic materials is presented and a much greater increase in residual trapping (defined as 10 pore volume water re-imbibition). Variation of leakage rate was not shown to result in significant difference in the overall saturation values, but the stability of the trapped plume was reduced at high CO2 injection rates. These results suggest that local capillary trapping could contribute to secondary trapping and slow the buoyancy-driven rise of CO2. These measurements could have important implications for minimizing risk associated with leakage from carbon sequestration sites.

  19. Interaction between hydroxypropyl methylcellulose and biphasic calcium phosphate after steam sterilisation: capillary gas chromatography studies.

    OpenAIRE

    Bourges, Xavier; Schmitt, Michel; Amouriq, Yves; Daculsi, Guy; Legeay, Gilbert; Pierre WEISS

    2001-01-01

    The purpose of this study was to check the chemical stability of an injectable bone substitute (IBS) composed of a 50/50 w/w mixture of a 2.92% hydroxypropyl methylcellulose (HPMC) solution in deionised water containing biphasic calcium phosphate (BCP) granules (60% hydroxyapatite/40% β-tricalcium phosphate w/w). After separation of the organic and mineral phases, capillary gas chromatography (GC) was used to study the possible modification of HPMC due to the contact with BCP granules followi...

  20. Nitrogen capillary plasma as a source of intense monochromatic radiation at 2.88 nm

    Czech Academy of Sciences Publication Activity Database

    Vrba, Pavel; Vrbová, M.; Zakharov, S.V.; Zakharov, V.S.; Jančárek, A.; Nevrkla, M.

    2014-01-01

    Roč. 196, October (2014), s. 24-30. ISSN 0368-2048 R&D Projects: GA ČR GAP102/12/2043; GA MŠk(CZ) LG13029 Grant ostatní: GA MŠk(CZ) CZ.1.07/2.3.00/20.0092 Institutional support: RVO:61389021 Keywords : Capillary Z-pinch * Water window radiation source * RHMD Code Z* Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.436, year: 2014 http://dx.doi.org/10.1016/j.elspec.2013.12.015

  1. Multi-scale simulation of capillary pores and gel pores in Portland cement paste

    OpenAIRE

    Gao, Peng; YE, guang; Wei, Jiangxiong; Yu, Qijun

    2015-01-01

    The microstructures of Portland cement paste (water to cement ratio is 0.4, curing time is from 1 day to 28 days) are simulated based on the numerical cement hydration model, HUMOSTRUC3D (van Breugel, 1991; Koenders, 1997; Ye, 2003). The nanostructures of inner and outer C-S-H are simulated by the packing of monosized (5 nm) spheres. The pore structures (capillary pores and gel pores) of Portland cement paste are established by upgrading the simulated nanostructures of C-S-H to th...

  2. The alveolar-capillary membrane diffusing capacity and the pulmonary capillary blood volume in heart transplant candidates

    OpenAIRE

    Al-Rawas, O; Carter, R.; Stevenson, R; Naik, S; Wheatley, D

    2000-01-01

    OBJECTIVES—To determine the mechanism of impairment of pulmonary transfer factor for carbon monoxide (TLCO) in heart transplant candidates, as this is the most common lung function abnormality.
SETTING—Regional cardiopulmonary transplant centre.
METHODS—TLCO and its components (the diffusing capacity of the alveolar-capillary membrane (DM) and the pulmonary capillary blood volume (VC)) were measured using the Roughton and Forster method and the single breath technique in 38 patients with seve...

  3. Monte Carlo nanodosimetry of alpha particle passages through the capillary endothelial nucleus application to systemic Targeted Alpha Therapy

    International Nuclear Information System (INIS)

    Full text: The biological effects of Targeted Alpha Therapy are strongly affected by the heterogeneous specific energy delivered to tumor cells. For systemic Targeted Alpha Therapy, all blood vessels inevitably received a background radiation from non-targeted decays with the blood circulation. The Geant4 Monte Carlo code was adapted to simulate the spatial non-uniform distribution of the alpha emitting radioisotope sources 213Bi, 212Bi and 211At. A cylindrical annulus was taken as a geometrical model to approximate the capillary. The endothelial cell nucleus was set to be an ellipsoid filled with liquid water to simulate nanometric target volumes at unit density. The Geant4 Low Energy physics model, based on the Livermore approach, was selected to model the particle interactions with the material in the experimental setup. The threshold of production of secondary particles was 7 eV. We validated the program with published results using spheroid cell geometry. The specific energy deposited in a capillary endothelial cell nucleus per radioactive decay and the capillary endothelial cell survival rates were calculated for the source constrained in the capillary lumen or the source binding to the surface antigen on the perivascular cancer cells. The measurement of nanodosimetric event size spectra based on simulated nanodosimetric data is presented. The value and limitations of this approach are discussed. (author)

  4. Capillary electrophoresis: Imaging of electroosmotic and pressure driven flow profiles in fused silica capillaries

    Science.gov (United States)

    Williams, George O., Jr.

    1996-01-01

    This study is a continuation of the summer of 1994 NASA/ASEE Summer Faculty Fellowship Program. This effort is a portion of the ongoing work by the Biophysics Branch of the Marshall Space Flight Center. The work has focused recently on the separation of macromolecules using capillary electrophoresis (CE). Two primary goals were established for the effort this summer. First, we wanted to use capillary electrophoresis to study the electrohydrodynamics of a sample stream. Secondly, there was a need to develop a methodology for using CE for separation of DNA molecules of various sizes. In order to achieve these goals we needed to establish a procedure for detection of a sample plug under the influence of an electric field Detection of the sample with the microscope and image analysis system would be helpful in studying the electrohydrodynamics of this stream under load. Videotaping this process under the influence of an electric field in real time would also be useful. Imaging and photography of the sample/background electrolyte interface would be vital to this study. Finally, detection and imaging of electroosmotic flow and pressure driven flow must be accomplished.

  5. Influence of pore morphology and topology on capillary trapping in geological carbon dioxide sequestration

    Science.gov (United States)

    Andersson, L.; Harper, E.; Herring, A. L.; Wildenschild, D.

    2012-12-01

    Current carbon capture and storage (CCS) techniques could reduce the release of anthropogenic CO2 into the atmosphere by subsurface sequestration of CO2 in saline aquifers. In geological storage CO2 is injected into deep underground porous formations where CO2 is in the supercritical state. Deep saline aquifers are particularly attractive because of their abundance and potentially large storage volumes. Despite very broad research efforts there are still substantial uncertainties related to the effectiveness of the trapping, dissolution, and precipitation processes controlling the permanent storage of CO2. After injection of CO2 the saline water (brine) will imbibe back and reoccupy the pore space as the CO2 moves upwards, trapping a large part of the CO2. This trapping mechanism is known as capillary trapping and occurs as isolated CO2 bubbles are locked in the brine inside the pores of the porous rock. The large-scale movement of CO2 within the brine is thereby prevented. This mechanism thus constitutes an important storage mechanism after the CO2 injection until the subsequent dissolution trapping and precipitation of carbonate mineral. The capillary trapping of CO2 depends largely on the shape and interconnectivity of the pore space and it is therefore important to study the influence of pore scale morphology and topology to understand and optimize large scale capillary trapping. We use a high pressure set-up, designed for supercritical CO2 conditions, with a flow cell compatible with synchrotron-based X-ray computed micro-tomography (CMT) to generate high-resolution images to study capillary trapping. We use sintered glass bead columns as an approximation for unconsolidated reservoir systems. The smooth surface glass bead data allow us to separate the chemistry and surface roughness effects of the porous medium from the effect of the morphology and topology on the capillary trapping. We will relate these aspects of the pore space to the distribution of the

  6. Pressurized liquid extraction–capillary electrophoresis–mass spectrometry for the analysis of polar antioxidants in rosemary extracts

    OpenAIRE

    Herrero, Miguel; Arráez-Román, David; Segura-Carretero, Antonio; Kendler, Ernst; Gius, Beatrice; Raggi, Maria Augusta; Ibáñez, Elena; Cifuentes, Alejandro

    2005-01-01

    A method based on capillary electrophoresis–electrospray–mass spectrometry (CE–ESI–MS) was developed to qualitatively characterize natural antioxidants from rosemary (Rosmarinus officinalis L.) in different fractions obtained by pressurized liquid extraction (PLE) using subcritical water. The parameters of CE–ESI–MS were adjusted allowing the separation and characterization of different compounds from rosemary in the PLE fractions. These parameters for CE are kind, pH and concentrati...

  7. Study of a capillary and chemical cover applied to reclamation of uranium mine tailings and rock waste

    International Nuclear Information System (INIS)

    The aim of this study is the feasibility and efficiency evaluation of an uranium mine tailings cover by natural products. The studied cover realizes three functions: the water infiltration control, the oxygen infiltration and the radon emanations control and the infiltration chemistry control. These three functions have been separately studied during specific experiments. The author demonstrates that the capillary cover allows to minimize the polluted waters volumes and the pollutants migration, by a control of water infiltration in the storage. (A.L.B.)

  8. Advances in Capillary Chromatography%毛细管色谱的进展

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Capillary columns are used in both capillary liquid chromatography and capillary electrochromatography. The design for capillary liquid chromatography is discussed in comparison with capillary gas chromatography. The difference of diffusion coefficient in gas and liquid phase is a key role. The study for obtaining a high performance capillary liquid chromatography is discussed. Capillary electrochromatography is recently interesting for its instinct ability to realize a high performance chromatography. Capillary electrochromatography with and without pressurized flow is reviewed briefly. Instrumentation for capillary electrochromatography with pressurized flow is discussed. The port of splitting, and gradient elution of both solution and potential are described. The new findings of both the variation of column resistance and capacity factor according to the value of applied electric voltage are also discussed.

  9. Experimental investigation on diabatic flow of R-134a through spiral capillary tube

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Mohd. Kaleem [Department of Mechanical Engineering, Thapar University, Patiala 147 004 (India); Kumar, Ravi; Sahoo, Pradeep K. [Department of Mechanical and Industrial Engineering, Indian Institute of Technology, Roorkee 247 667, Uttarakhand (India)

    2009-03-15

    The present experimental investigation has been carried out to investigate the effects of various geometric parameters on the mass flow rate of R-134a through diabatic spiral capillary tube. In diabatic flow, the capillary tube is bonded with the compressor suction-line to form a counter-flow exchanger. The lateral type of diabatic capillary tube has been investigated in the present experimental study. The major geometric parameters investigated are capillary tube diameter, capillary tube length and coil pitch. In addition, effect of inlet subcooling on the mass flow rate through diabatic spiral capillary tube is also done. A comparison of the performance of diabatic spiral capillary tube has been made with adiabatic spiral capillary tube. Generalized empirical correlation for diabatic spiral capillary tube has also been proposed. It has been found that the predictions of the proposed correlation lie in the error band of {+-}7%. (author)

  10. Unseeded Large Scale PIV measurements accounting for capillary-gravity waves phase speed

    CERN Document Server

    Benetazzo,; Gamba,; M.,; Barbariol,; F,

    2016-01-01

    Large Scale Particle Image Velocimetry (LSPIV) is widely recognized as a reliable method to measure water surface velocity field in open channels and rivers. LSPIV technique is based on a camera view that frames the water surface in a sequence, and image-processing methods to compute water surface displacements between consecutive frames. Using LSPIV, high flow velocities, as for example flood conditions, were accurately measured, whereas determinations of low flow velocities is more challenging, especially in absence of floating seeding transported by the flow velocity. In fact, in unseeded conditions, typical surface features dynamics must be taken into account: besides surface structures convected by the current, capillary-gravity waves travel in all directions, with their own dynamics. Discrimination between all these phenomena is here discussed, providing a new method to distinguish and to correct unseeded LSPIV measurements associated with wavy structures, accounting for their phase speed magnitude and ...

  11. Tomographic Imaging of Water Injection and Withdrawal in PEMFC Gas Diffusion Layers

    Energy Technology Data Exchange (ETDEWEB)

    McGill U; Gostick, J. T.; Gunterman, H. P.; Weber, A. Z.; Newman, J. S.; Kienitz, B. L.; MacDowell, A. A.

    2010-06-25

    X-ray computed tomography was used to visualize the water configurations inside gas diffusion layers for various applied capillary pressures, corresponding to both water invasion and withdrawal. A specialized sample holder was developed to allow capillary pressure control on the small-scale samples required. Tests were performed on GDL specimens with and without hydrophobic treatments.

  12. Pressure resistance of glass capillaries for hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Holtappels, Kai; Beckmann-Kluge, Martin; Gebauer, Marek [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany); Eliezer, Dan

    2011-07-01

    A crucial problem in the development of new hydrogen technologies is the need for lightweight and safe storage of acceptable amounts of hydrogen, in particular for portable or mobile applications. A new and innovative technology based on capillary arrays has been developed. These systems ensure the safe infusion, storage, and controlled release of hydrogen gas, even when storage pressures of up to 1200 bar are applied. This technology enables the storage of a significantly higher amount of hydrogen than other approaches. It has already surpassed the US Department of Energy's 2010 target, and is expected to meet the DOE's 2015 target in the near future. The main determinant in this storage technology is the pressure resistance of glass capillaries. It is well known that quartz, for example, is three times stronger than steel. At the same time, the density is about three times lower which means that much less material is necessary to reach the same pressure resistance. The pressure resistance of single capillaries has been determined in relation to various capillary materials and dimensions, wall thicknesses etc. in order to find out optimal parameters for the 'final' capillaries. (orig.)

  13. Capillary plexuses are vulnerable to neutrophil extracellular traps.

    Science.gov (United States)

    Boneschansker, Leo; Inoue, Yoshitaka; Oklu, Rahmi; Irimia, Daniel

    2016-02-01

    Capillary plexuses are commonly regarded as reliable networks for blood flow and robust oxygen delivery to hypoxia sensitive tissues. They have high levels of redundancy to assure adequate blood supply when one or more of the capillaries in the network are blocked by a clot. However, despite having extensive capillary plexuses, many vital organs are often subject to secondary organ injury in patients with severe inflammation. Recent studies have suggested that neutrophils play a role in this pathology, even though their precise contribution remains elusive. Here we investigate the effect of chromatin fibres released from overly-activated neutrophils (neutrophil extracellular traps, NETs) on the flow of blood through microfluidic networks of channels replicating geometrical features of capillary plexuses. In an in vitro setting, we show that NETs can decouple the traffic of red blood cells from that of plasma in microfluidic networks. The effect is astonishingly disproportionate, with NETs from less than 200 neutrophils resulting in more than half of a 0.6 mm(2) microfluidic network to become void of red blood cell traffic. Importantly, the NETs are able to perturb the blood flow in capillary networks despite the presence of anti-coagulants. If verified to occur in vivo, this finding could represent a novel mechanism for tissue hypoxia and secondary organ injury during severe inflammation in patients already receiving antithrombotic and anticoagulant therapies. PMID:26797289

  14. MATHEMATICAL MODELING OF ELECTROCONVECTION IN THE CAPILLARIES. TRANSIENT BEHAVIOR

    Directory of Open Access Journals (Sweden)

    Kovalenko A. V.

    2015-06-01

    Full Text Available We propose a mathematical model of ion transport binary salt in electroosmotic flow in a capillary. The capillary is open on one side and immersed in a vessel of large volume, in which the concentration of the solution is maintained constant, and the other side closed ion exchange membrane. The walls are considered wettable, i.e. the solution adheres to the walls. This means that the mathematical modeling used to rate the condition of sticking. We study the boundary value problem for a coupled system of equations Nernst, Planck, Poisson and Navier-Stokes equations. Used boundary conditions of general form. The mathematical model is based on the general laws of transport and contains no adjustable parameters. Using this model, the basic laws of ion transport salt solution liquid flow, the emergence and development electroconvection, distribution of concentration of salt ions in the capillary with a small change in time, ie, in the initial (transitional regime. We have identified the presence of ion-exchange membrane surface electroconvective vortices and their influence on the mechanisms of ion transport of salt and fluid movement in different areas of the capillary. A feature of the capillary transport is to the right of the vortex region stagnant areas with a higher concentration of ions

  15. On the performance of capillary barriers as landfill cover

    Science.gov (United States)

    Kämpf, M.; Montenegro, H.

    Landfills and waste heaps require an engineered surface cover upon closure. The capping system can vary from a simple soil cover to multiple layers of earth and geosynthetic materials. Conventional design features a compacted soil layer, which suffers from drying out and cracking, as well as root and animal intrusion. Capillary barriers consisting of inclined fine-over-coarse soil layers are investigated as an alternative cover system. Under unsaturated conditions, the textural contrast delays vertical drainage by capillary forces. The moisture that builds up above the contact will flow downdip along the interface of the layers. Theoretical studies of capillary barriers have identified the hydraulic properties of the layers, the inclination angle, the length of the field and the infiltration rate as the fundamental characteristics of the system. However, it is unclear how these findings can lead to design criteria for capillary barriers. To assess the uncertainty involved in such approaches, experiments have been carried out in a 8 m long flume and on large scale test sites (40 m x 15 m). In addition, the ability of a numerical model to represent the relevant flow processes in capillary barriers has been examined.

  16. Basement membrane changes in capillaries of the ageing human retina

    Science.gov (United States)

    Powner, Michael B; Scott, Andrew; Zhu, Meidong; Munro, Peter M G; Foss, Alexander J E; Hageman, Gregory S; Gillies, Mark C; Fruttiger, Marcus

    2014-01-01

    Objectives The ultrastructural appearance of retinal capillaries can yield important information about disease mechanisms, but is not well characterised in human post mortem samples. We therefore aimed to create a baseline for the appearance of capillaries and establish how this is influenced by post mortem fixation delays and donor age. Methods Electron microscopy was used to characterise retinal capillaries in 20 anonymous donors (with no known eye diseases) of various ages and with various post mortem fixation delays. In addition, samples from six patients with conditions that are known to affect the retinal vasculature (four cases of type 2 diabetes without diabetic retinopathy, one case of diabetic retinopathy and one case of macular telangiectasia type 2) were analysed. Results Vacuoles were found in capillary basement membranes at the vessel—glia interface in all samples, from both the normal and disease cases. Vacuole frequency increased with donor age but was not influenced by post mortem fixation delays. Conclusion Vacuoles in the basement membrane are a normal feature of adult human retinal capillaries and do not indicate disease. Their incidence increases with age and might be a contributing factor to late-onset pathologies of the retinal vasculature. PMID:21606466

  17. Effect of dynamic contact angle in a volume of fluid (VOF) model for a microfluidic capillary flow.

    Science.gov (United States)

    Ashish Saha, Auro; Mitra, Sushanta K

    2009-11-15

    We perform three-dimensional numerical and experimental study of the dynamic contact angle using volume of fluid (VOF) method applied to microfluidic channels with integrated pillars. Initially, we evaluated different dynamic contact angle models (hydrodynamic, molecular kinetic and empirical) for capillary filling of a two-dimensional microchannel using analytical formulation. Further, the models which require a minimum prescription of adjustable parameters are only used for the study of capillary filling of microchannels with integrated pillars using different working fluids such as DI water, ethanol and isopropyl alcohol. Different microchannel geometry with varying diameter/height/spacing were studied for circular pillars. Effect of square pillars and changing the overall number of pillars on the capillary phenomena were also simulated. Our study demonstrated that the dynamic contact angle models modifies the transient response of the meniscus displacement and also the observed trends are model specific for the various microchannel geometries and working fluids. However, the different models have minimal effect on the meniscus profile. Different inlet boundary conditions were applied to observe the effect of grid resolution selected for numerical study on the capillary filling time. A grid dependent dynamic contact angle model which incorporates effective slip in the model was also used to observe the grid convergence of the numerical results. The grid independence was shown to improve marginally by applying the grid dependent dynamic contact angle model. Further we did numerical experiments of capillary filling considering variable surface wettability on the top and bottom walls of the microchannel with alternate hydrophilic-hydrophobic patterns. The meniscus front pinning was noticed for a high wetting contrast between the patterns. Non uniform streamline patterns indicated mixing of the fluid when using patterned walls. Such a microfluidic device with

  18. Applications on thermostable polar capillary GC columns

    Directory of Open Access Journals (Sweden)

    Lercker, G.

    2002-03-01

    Full Text Available The composition, the effect of processing and storage, and the overall quality of food lipids can be evaluated by gas chromatography (GC. GC analyses are carried out on non-polar or polar capillary columns, which separate the various lipid components according to their polarity and boiling points. However, there are components with high-boiling points that require higher temperatures in order to be better resolved. Thermostable polar GC columns with a relatively low column bleeding, can be used for this scope. These columns generate GC traces with different separation characteristics, which can lead to the identification of components that cannot be completely resolved with non-polar GC columns. Thermostable polar GC columns are suitable for the separation of different lipid classes and can be utilised for a fast screening of the total unsaponifiable matter of the oil or lipid extract. A series of examples for the analysis of food lipids with thermostable polar GC columns, are here described.La composición, el efecto del procesamiento y el almacenamiento, y la calidad total de los alimentos grasos se pueden evaluar por cromatografía de gases (GC. El análisis cromatográfico se lleva a cabo con columnas capilares polares y apolares que separan los diferentes componentes lipídicos de acuerdo a su polaridad y punto de ebullición. Sin embargo, existen componentes con altos puntos de ebullición que requieren temperaturas más elevadas para lograr una mejor separación. Las columnas polares termoestables de cromatografía de gases con un “sangrado” relativamente bajo, se pueden usar para esta actividad. Estas columnas generan cromatogramas con características diferentes que pueden conducir a la identificación de componentes que no pueden ser completamente resueltos con columnas no polares. Las columnas polares termoestables de cromatografía de gases son óptimas para la separación de las diferentes clases de lípidos y pueden ser

  19. Capillary flow in an interior corner

    Science.gov (United States)

    Weislogel, Mark M.; Lichter, Seth

    1998-10-01

    The design of fluids management processes in the low-gravity environment of space requires an accurate description of capillarity-controlled flow in containers. Here we consider the spontaneous redistribution of fluid along an interior corner of a container due to capillary forces. The analytical portion of the work presents an asymptotic formulation in the limit of a slender fluid column, slight surface curvature along the flow direction z, small inertia, and low gravity. The scaling introduced explicitly accounts for much of the variation of flow resistance due to geometry and so the effects of corner geometry can be distinguished from those of surface curvature. For the special cases of a constant height boundary condition and a constant flow condition, the similarity solutions yield that the length of the fluid column increases as t1/2 and t3/5, respectively. In the experimental portion of the work, measurements from a 2.2 s drop tower are reported. An extensive data set, collected over a previously unexplored range of flow parameters, includes estimates of repeatability and accuracy, the role of inertia and column slenderness, and the effects of corner angle, container geometry, and fluid properties. At short times, the fluid is governed by inertia (t[less, similar]tLc). Afterwards, an intermediate regime (tLc[less, similar]t[less, similar] tH) can be shown to be modelled by a constant-flow-like similarity solution. For t[gt-or-equal, slanted]tH it is found that there exists a location zH at which the interface height remains constant at a value h(zH, t)=H which can be shown to be well predicted. Comprehensive comparison is made between the analysis and measurements using the constant height boundary condition. As time increases, it is found that the constant height similarity solution describes the flow over a lengthening interval which extends from the origin to the invariant tip solution. For t[dbl greater-than sign]tH, the constant height solution

  20. Evaluation of two-phase relative permeability and capillary pressure relations for unstable displacements in a pore network

    Energy Technology Data Exchange (ETDEWEB)

    Dehoff, Karl J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Oostrom, Martinus [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zhang, Changyong [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Grate, Jay W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2012-10-29

    A series of displacement experiments was conducted using five wetting-nonwetting immiscible fluid pairs in a homogenous and uniform pore network. The micromodel was initially saturated with either polyethylene glycol 200 (PEG) or water as a wetting fluid, which was subsequently displaced by a nonwetting fluid (dodecane, hexadecane, or mineral oil) at different flow rates. The experiments were designed to allow determinations of nonwetting fluid relative permeabilities ( ), fluid saturations ( ), and capillary pressure heads ( ). In the displacements, nonwetting fluid saturations increased with increasing flow rates for all five fluid pairs, and viscous fingering, capillary fingering, and stable displacement were observed. Viscous fingering occurred when PEG was displaced by either dodecane or hexadecane. For the water displacements, capillary fingers were observed at low capillary numbers. Due to unstable fingering phenomena, values for the PEG displacements were smaller than for the water displacements. A fitting exercise using the Brooks-Corey (1964) relationship showed that the fitted entry pressure heads are reasonably close to the computed entry pressure head. The fitted pore geometry factor, Sn values for the displacements are considerably lower than what is expected for displacements in homogeneous, highly uniform, porous systems, demonstrating the impact of unstable displacement on the apparent value of Sn. It was shown that a continuum-based multiphase model could be used to predict the average behavior for wetting fluid drainage in a pore network as long as independently fitted - and - relations are used. The use of a coupled approach through the Brooks-Corey pore geometry factor underpredicts observed values.

  1. Determination of anions with an on-line capillary electrophoresis method; Anionien on-line maeaeritys kapillaarielektroforeesilla - MPKT 10

    Energy Technology Data Exchange (ETDEWEB)

    Siren, H.; Saerme, T.; Kotiaho, T.; Hiissa, T.; Savolahti, P.; Komppa, V. [VTT Chemical Technology, Espoo (Finland)

    1998-12-31

    The aim of the study was to set-up an on-line capillary electrophoresis method for determination of anions in process waters of pulp and paper industry with exporting the results to the process control system of the mill. The quantification is important, since it will give information about the possible causes of precipitation. In recent years, the capillary electrophoresis (CE) due to its high separation efficiency has been shown as a method to take into consideration when analyzing chemical species ranging from small inorganic anions to different macromolecules. Many compounds are not easily detected in their native state, why analysis methods must be developed to improve their detection. Especially, small inorganic and organic anions which do not have chromophores are not sensitive enough for direct-UV detection. In such analyses the anions are mostly detected with indirect-UV technique. Capillary electrophoresis instruments are used to analyze samples in off-line, which seldom represent the situation in process. Therefore, on-line instrument technology with autoanalyzing settings will be needed in quality control. The development of a fully automatic capillary electrophoresis system is underway in co-operation with KCL (The Finnish Pulp and Paper Research Institute). In our research, we have first concentrated on the determination of sulphate in waters of paper industry. The method used for detection of sulphate is based on indirect-UV detection with CE, where the background electrolyte (BGE) is an absorbing mixture of secondary amines. The whole procedure for quantification of sulphate is performed within 15 minutes, after which a new sample is analyzed automatically. The only sample pretreatment is filtration, which is necessary before analysis. The concentrations of sulphate in process waters tested were between 300 and 800 ppm. Our tests show that a simultaneous determination of chloride, sulphate, nitrate, nitrite, sulphite, carbonate and oxalate is also

  2. The history of the capillary wall: doctors, discoveries, and debates.

    Science.gov (United States)

    Hwa, Charlotte; Aird, William C

    2007-11-01

    In 1628, William Harvey provided definitive evidence that blood circulates. The notion that blood travels around the body in a circle raised the important question of how nutrients pass between blood and underlying tissue. Perhaps, Harvey posited, arterial blood pours into the flesh as into a sponge, only then to find its way into the veins. Far from solving this problem, Marcello Malpighi's discovery of the capillaries in 1661 only added to the dilemma: surely, some argued, these entities are little more than channels drilled into tissues around them. As we discuss in this review, it would take over 200 years to arrive at a consensus on the basic structure and function of the capillary wall. A consideration of the history of this period provides interesting insights into not only the central importance of the capillary as a focus of investigation, but also the enormous challenges associated with studying these elusive structures. PMID:17693543

  3. Computational modelling of slug flow in a capillary microreactor

    Science.gov (United States)

    Kashid, M. N.; Platte, F.; Agar, D. W.; Turek, S.

    2007-06-01

    The benefits of slug flow capillary microreactor exhibit the ability to adjust two individual transport mechanisms, i.e., convection inside the slug and diffusion between two consecutive slugs. The mass transfer rate is enhanced by internal circulation, which arises due to the shear between slug axis and continuous phase or capillary wall. The knowledge of circulation patterns within the slug plays an important role in the design of a capillary microreactor. Apart from this, well defined slug flow generation is a key activity in the development of methodology to study hydrodynamics and mass transfer. In the present paper we discuss computational fluid dynamics (CFD) modelling aspects of internal circulations (single phase) and slug flow generation (two-phase).

  4. Capillary-inertial colloidal catapults upon drop coalescence

    Science.gov (United States)

    Chavez, Roger L.; Liu, Fangjie; Feng, James J.; Chen, Chuan-Hua

    2016-07-01

    Surface energy released upon drop coalescence is known to power the self-propelled jumping of liquid droplets on superhydrophobic solid surfaces, and the jumping droplets can additionally carry colloidal payloads toward self-cleaning. Here, we show that drop coalescence on a spherical particle leads to self-propelled launching of the particle from virtually any solid surface. The main prerequisite is an intermediate wettability of the particle, such that the momentum from the capillary-inertial drop coalescence process can be transferred to the particle. By momentum conservation, the launching velocity of the particle-drop complex is proportional to the capillary-inertial velocity based on the drop radius and to the fraction of the liquid mass in the total mass. The capillary-inertial catapult is not only an alternative mechanism for removing colloidal contaminants, but also a useful model system for studying ballistospore launching.

  5. Exploring the pressure resistance limits of monolithic silica capillary columns.

    Science.gov (United States)

    Hara, Takeshi; Eeltink, Sebastiaan; Desmet, Gert

    2016-05-13

    We report on an experimental approach to measure the pressure stability and mechanical strength of monolithic silica capillary columns with different diameters (50 and 100μm i.d.) and considering two different domain sizes, typical for the second generation monoliths or smaller. The approach consists of exposing the capillaries to ultra-high pressures (gradually stepwise increased from 20 to 80MPa), with intermediate measurements of the column efficiency, permeability and retention factors to check the mechanical stability of the bed. It was observed that all tested columns withstood the imposed pressure stress, i.e., all the tested parameters remained unaffected up till the maximal test pressure of 80MPa. The applied pressure gradient corresponded to 320MPa/m. The two 100μm i.d.-capillary columns were also exposed to pressures between 80 and 90MPa for a prolonged time (8h), and this did not cause any damage either. PMID:27086284

  6. Dynamic capillary wetting studied with dissipative particle dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Cupelli, Claudio; Glatzel, Thomas; Zengerle, Roland; Santer, Mark [Laboratory for MEMS applications, Department of Microsystems Engineering (IMTEK), University of Freiburg, Georges-Koehler-Allee 106, 79110 Freiburg (Germany); Henrich, Bjoern; Moseler, Michael [Freiburg Materials Research Center (FMF), Stefan-Meier-Strasse 21, 79104 Freiburg (Germany)], E-mail: cupelli@imtek.de

    2008-04-15

    We present a study on dynamic capillary wetting in the framework of dissipative particle dynamics (DPD) based on a novel wall model for wetting on solid boundaries. We consider capillary impregnation of a slit pore in two situations: (i) forced (piston-driven) steady state flow and (ii) capillarity driven imbibition out of a finite reservoir. The dynamic contact angle behavior under condition (i) is consistent with the hydrodynamic theories of Cox under partial wetting conditions and Eggers for complete wetting. The flow field near the contact line shows a region of apparent slip flow which provides a natural way of avoiding a stress singularity at the triple line. The dynamics of the capillary imbibition, i.e. condition (ii), is consistently described by the Lucas-Washburn equation augmented by expressions that account for inertia and the influence of the dynamic contact angle.

  7. Rapid fabrication of supercapacitor electrodes using bionanoscaffolds in capillary microfluidics

    Science.gov (United States)

    Zang, F.; Chu, S.; Gerasopoulos, K.; Culver, J. N.; Ghodssi, R.

    2015-12-01

    This paper reports the utilization of capillary microfluidics to rapidly create nanostructure-patterned electrodes for energy storage applications. Using patterned photoresist as open-channel capillary microfluidics, Tobacco mosaic virus (TMV) bio-nanoscaffolds suspended in solution are autonomously delivered onto planar gold electrodes over a 1 cm2 area. The TMVs assemble on the electrode and form a dense bio-nanoscaffold layer due to enhanced evaporation-assisted assembly in the open-channel capillary microfluidic device within an hour. The TMV structures are coated with Ni/NiO through electroless plating and thermal oxidation to form supercapacitor electrodes. The galvanostatic charge/discharge cycle showed a 3.6-fold increase in areal capacitance for the nanostructured electrode compared to planar structures.

  8. Capacitive measurement of mercury column heights in capillaries.

    Science.gov (United States)

    Frey, Sarah; Richert, Ranko

    2010-03-01

    The detection of changes in volume, e.g., in expansivity or aging measurements, are often translated into mercury column height within a glass capillary. We propose a capacitive technique for measuring the meniscus position using a cylindrical capacitor with mercury as the inner electrode, the capillary material as the dielectric, and a metal coat covering the outside surface of the capillary as the second electrode. The measured capacitance changes linearly with meniscus height, as long as the top mercury level remains within the range of the outer electrode. With the demonstrated noise level of 48 nm for our preliminary setup, meniscus height changes beyond 100 nm can be observed via the capacitance. PMID:20370203

  9. Differential Capillary Effect Model of Fabric and Its Application

    Institute of Scientific and Technical Information of China (English)

    王其; 冯勋伟

    2003-01-01

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

  10. An improved interface for capillary zone electrophoresis-mass spectrometry

    International Nuclear Information System (INIS)

    We have recently developed an improved electrospray ionization interface for capillary electrophoresis mass-spectrometry (CZE-MS). Our initial interface employed a vacuum deposited metal film at the exit of the capillary to make an electrical contact with he eluting buffer and establish the electrospray field gradient. This interface did, however, impose significant limitations on the range of capillary electrophoretic (CE) separations that could be performed. To circumvent these limitations, an interface that does not require a metalized tip was designed nd developed. In the new approach, the electrical contact at the column exit is made through a flowing liquid sheath. The principal advantage of this interface is that it allows operation with a much broader range of electrophoresis conditions. The sheath flow can be readily varied in both composition and volume. An electrospray ionization spectrum is given for a previously intractable buffer solution. 5 refs., 2 figs

  11. Integration of amperometric sensors for microchip capillary electrophoresis application

    International Nuclear Information System (INIS)

    Capillary electrophoresis is a technique for the separation and analysis of chemical compounds. Techniques adopted from the microchip technology knowledge have led to recent developments of electrophoresis system with integration on microchip. Microchip Capillary Electrophoresis (μCE) systems offer a series of advantages as easy integration for Lab-on-a-chip applications, high performance, portability, speed, minimal solvent and sample requirements. A new technological challenge aims at the development of an economic modular microchip capillary electrophoresis systems using separable and independent units concerning the sensor. In this project we worked on the development of an interchangeable amperometric sensor in order to provide a solution to such electrode passivation and facilitating the use of tailored sensors for specific analyte detection besides. Fluidic chips have been machined from cyclic olefin polymer pallets (Zeonor) using a micro-injection molding machine.

  12. Acupuncture Sample Injection for Microchip Capillary Electrophoresis and Electrokinetic Chromatography.

    Science.gov (United States)

    Ha, Ji Won; Hahn, Jong Hoon

    2016-05-01

    A simple nanoliter-scale injection technique was developed for polydimethylsiloxane (PDMS) microfluidic devices to form the well-defined sample plugs in microfluidic channels. Sample injection was achieved by performing acupuncture on a channel with a needle and applying external pressure to a syringe. This technique allowed us to achieve reproducible injection of a 3-nL segment into a microchannel for PDMS microchip-based capillary electrophoresis (CE). Capillary zone electrophoresis (CZE) and capillary electrochromatography (CEC) with bead packing were successfully performed by applying a single potential in the most simplified straight channel. The advantages of this acupuncture injection over the electrokinetic injection in microchip CE include capability of minimizing sample loss and voltage control hardware, capability of serial injections of different sample solutions into a same microchannel, capability of injecting sample plugs into any position of a microchannel, independence on sample solutions during the loading step, and ease in making microchips due to the straight channel, etc. PMID:27056036

  13. First attempts to combine capillary tubes with photocathodes

    CERN Document Server

    Peskov, Vladimir; Sokolova, T; Radionov, I

    1999-01-01

    We describe our efforts to combine glass capillary plates, operating as a gas amplification structure at approx 1 atm, with photocathodes sensitive to visible light. Such capillary tubes are a by-product of the manufacture of Microchannel Plates and are commercially available. Preliminary tests indicate that gas gains >10 sup 3 could be achieved without photon feedback. With two capillary plates in tandem (double-step multiplication) overall gains up to 10 sup 5 were possible at counting rate <100 Hz/mm sup 2. This approach may open new possibilities for detection of visible photons by gaseous detectors. Potential advantages are: high gains, large sensitive area, high granularity, and insensitivity to magnetic fields.

  14. Numerical simulation of the resonantly excited capillary-gravity waves

    Science.gov (United States)

    Hanazaki, Hideshi; Hirata, Motonori; Okino, Shinya

    2015-11-01

    Capillary gravity waves excited by an obstacle are investigated by a direct numerical simulation. In the flow without capillary effects, it is well known that large-amplitude upstream advancing solitary waves are generated periodically under the resonant condition, i.e., when the phase velocity of the long surface waves and the mean flow velocity agrees. With capillary effects, solutions of the Euler equations show the generation of very short waves further upstream of the solitary waves and also in the depression region downstream of the obstacle. The overall characteristics of these waves agree with the solutions of the forced fifth-order KdV equation, while the weakly nonlinear theory generally overestimates the wavelength of the short waves.

  15. The fine structure of capillaries and small arteries.

    Science.gov (United States)

    MOORE, D H; RUSKA, H

    1957-05-25

    Details of capillary endothelia of the mammalian heart are described and compared with capillaries of other organs and tissues. Continuous invagination and pinching off of the plasma membrane to form small vesicles which move across the cytoplasm are suggested as constituting a means of active and selective transmission through capillary walls (12). This might be designated as cytopempsis (transmission by cell). The fine structure of the different layers in the walls of small heart arteries is demonstrated. Endothelial protrusions extend through windows of the elestica interna to make direct contact with smooth muscle plasma membranes. The elastica interna appears to vary greatly in both thickness and density, and probably restricts filtration, diffusion, and osmosis to such an extent that windows and the transport mechanisms described (cytopempsis) are necessary for the functional integrity of the smooth muscle layer. The contractile material consists of very fine, poorly oriented filaments. PMID:13438930

  16. Density functional study of condensation in capped capillaries.

    Science.gov (United States)

    Yatsyshin, P; Savva, N; Kalliadasis, S

    2015-07-15

    We study liquid adsorption in narrow rectangular capped capillaries formed by capping two parallel planar walls (a slit pore) with a third wall orthogonal to the two planar walls. The most important transition in confined fluids is arguably condensation, where the pore becomes filled with the liquid phase which is metastable in the bulk. Depending on the temperature T, the condensation in capped capillaries can be first-order (at T≤Tcw) or continuous (at T>Tcw), where Tcw is the capillary wetting temperature. At T>Tcw, the capping wall can adsorb mesoscopic amounts of metastable under-condensed liquid. The onset of condensation is then manifested by the continuous unbinding of the interface between the liquid adsorbed on the capping wall and the gas filling the rest of the capillary volume. In wide capped capillaries there may be a remnant of wedge filling transition, which is manifested by the adsorption of liquid drops in the corners. Our classical statistical mechanical treatment predicts a possibility of three-phase coexistence between gas, corner drops and liquid slabs adsorbed on the capping wall. In sufficiently wide capillaries we find that thick prewetting films of finite length may be nucleated at the capping wall below the boundary of the prewetting transition. Prewetting then proceeds in a continuous manner manifested by the unbinding interface between the thick and thin films adsorbed on the side walls. Our analysis is based on a detailed numerical investigation of the density functional theory for the fluid equilibria for a number of illustrative case studies. PMID:26086161

  17. Photo inactivation of virus particles in microfluidic capillary systems.

    Science.gov (United States)

    Ren, Yudan; Crump, Colin M; Mackley, Malcolm M; Li Puma, Gianluca; Reis, Nuno M

    2016-07-01

    It has long been established that UVC light is a very effective method for inactivating pathogens in a fluid, yet the application of UVC irradiation to modern biotechnological processes is limited by the intrinsic short penetration distance of UVC light in optically dense protein solutions. This experimental and numerical study establishes that irradiating a fluid flowing continuously in a microfluidic capillary system, in which the diameter of the capillary is tuned to the depth of penetration of UVC light, uniquely treats the whole volume of the fluid to UVC light, resulting in fast and effective inactivation of pathogens, with particular focus to virus particles. This was demonstrated by inactivating human herpes simplex virus type-1 (HSV-1, a large enveloped virus) on a dense 10% fetal calf serum solution in a range of fluoropolymer capillary systems, including a 0.75 mm and 1.50 mm internal diameter capillaries and a high-throughput MicroCapillary Film with mean hydraulic diameter of 206 μm. Up to 99.96% of HSV-1 virus particles were effectively inactivated with a mean exposure time of up to 10 s, with undetectable collateral damage to solution proteins. The kinetics of virus inactivation matched well the results from a new mathematical model that considers the parabolic flow profile in the capillaries, and showed the methodology is fully predictable and scalable and avoids both the side effect of UVC light to proteins and the dilution of the fluid in current tubular UVC inactivation systems. This is expected to speed up the industrial adoption of non-invasive UVC virus inactivation in clinical biotechnology and biomanufacturing of therapeutic molecules. Biotechnol. Bioeng. 2016;113: 1481-1492. © 2015 Wiley Periodicals, Inc. PMID:26694540

  18. Density functional study of condensation in capped capillaries

    Science.gov (United States)

    Yatsyshin, P.; Savva, N.; Kalliadasis, S.

    2015-07-01

    We study liquid adsorption in narrow rectangular capped capillaries formed by capping two parallel planar walls (a slit pore) with a third wall orthogonal to the two planar walls. The most important transition in confined fluids is arguably condensation, where the pore becomes filled with the liquid phase which is metastable in the bulk. Depending on the temperature T, the condensation in capped capillaries can be first-order (at T≤slant {{T}\\text{cw}} ) or continuous (at T\\gt {{T}\\text{cw}} ), where {{T}\\text{cw}} is the capillary wetting temperature. At T \\gt {{T}\\text{cw}} , the capping wall can adsorb mesoscopic amounts of metastable under-condensed liquid. The onset of condensation is then manifested by the continuous unbinding of the interface between the liquid adsorbed on the capping wall and the gas filling the rest of the capillary volume. In wide capped capillaries there may be a remnant of wedge filling transition, which is manifested by the adsorption of liquid drops in the corners. Our classical statistical mechanical treatment predicts a possibility of three-phase coexistence between gas, corner drops and liquid slabs adsorbed on the capping wall. In sufficiently wide capillaries we find that thick prewetting films of finite length may be nucleated at the capping wall below the boundary of the prewetting transition. Prewetting then proceeds in a continuous manner manifested by the unbinding interface between the thick and thin films adsorbed on the side walls. Our analysis is based on a detailed numerical investigation of the density functional theory for the fluid equilibria for a number of illustrative case studies.

  19. A novel ionic liquids grafted polysiloxane for capillary gas chromatography

    Institute of Scientific and Technical Information of China (English)

    Qing Quan Wei; Mei Ling Qi; Ruo Nong Fu

    2009-01-01

    A new ionic liquids grafted polysiloxane used as stationary phase for capillary gas chromatography(CGC)is described.The stationary phase of 1-vinyl-3-hexylimidazolium hexafluorophosphate anchored to polysiloxane(PMHS-[VHIm][PF6])was synthesized,characterized and coated onto capillary columns by static coating.The results show that the present stationary phase exhibits a very good chromatographic resolution and selectivity for Grob test mixture and alcohols with baseline resolution and symmetry peaks.The present work suggests that novel stationary phase has a great potential for further development and application.

  20. Separation and quantification of cellulases and hemicellulases by capillary electrophoresis

    DEFF Research Database (Denmark)

    Jørgensen, Henning; Kutter, Jörg Peter; Olsson, Lisbeth

    2003-01-01

    Cellulases and hemicellulases are two classes of enzymes produced by filamentous fungi and secreted into the cultivation medium. Both classes of enzymes consist of a subset of classes of which the fungi produce several enzymes with varying molecular mass and pI but similar enzymatic activities...... silica capillary at pH values close to neutral. The improvement of the separation of these six proteins by the addition of alpha, omega-diaminoalkanes with chain lengths from three to seven carbon units was investigated. Dynamically coating the capillary with 1,3-diaminopropane resulted in separation of...

  1. Freezing of capillary waves at the glass transition

    International Nuclear Information System (INIS)

    The freezing of capillary waves on glycerol surfaces is studied by in situ x-ray reflectivity measurements. A wide temperature range around the calorimetric glass transition temperature at Tg≅186 K is investigated. For T>250 K the obtained surface roughness as a function of the temperature differs significantly from the value predicted by the classical capillary waves theory. Below the temperature T≅250 K the magnitude of the roughness remains constant. Furthermore, a large hysteresis, i.e., a large difference of the roughnesses measured during cooling and heating of the sample, is observed. These findings are discussed in terms of viscosity effects

  2. Capillary zone electrophoresis for the analysis of glycoforms of cellobiohydrolase

    OpenAIRE

    Gupta R, Baldock S J, Fielden P R, Prest J E, Grieve B D

    2011-01-01

    Cellobiohydrolase (CBH) is an important enzyme for the conversion of lignocellulosic biomass to ethanol. This work separated the glycoforms of CBH possessing different numbers of neutral mannoses using capillary zone electrophoresis (CZE) in a 50 mM, pH 7.5 phosphate buffer. The method analysed CBH in an intact form using a polyacrylamide coated fused silica capillary without requiring additives or labelling of the enzyme. The migration time of the major peak was found to be 21.6 ± 0.1 min (n...

  3. A capillary-driven micromixer: idea and fabrication

    International Nuclear Information System (INIS)

    Microfluidic systems have been drawing attention upon the various branches of engineering science and the allied areas within biology and biomedicine. In this paper, a fabrication of a capillary-driven micromixer using photoresist JSR and glasses is proposed. We design three types of planar capillary-driven micormixers with different sizes of baffles in the channel. Flow tests have shown that the micromixer with a baffle gap of 100 μm and space of 100 μm reaches a best mixing performance of 93% in gray-level image analysis. (paper)

  4. A capillary-driven micromixer: idea and fabrication

    Science.gov (United States)

    Lee, Chun-Te; Lee, Chun-Che

    2012-10-01

    Microfluidic systems have been drawing attention upon the various branches of engineering science and the allied areas within biology and biomedicine. In this paper, a fabrication of a capillary-driven micromixer using photoresist JSR and glasses is proposed. We design three types of planar capillary-driven micormixers with different sizes of baffles in the channel. Flow tests have shown that the micromixer with a baffle gap of 100 μm and space of 100 μm reaches a best mixing performance of 93% in gray-level image analysis.

  5. Study of separation of PAMAM dendrimers by capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Sedláková, Pavla; Svobodová, Jana; Mikšík, Ivan; Tomás, H.

    Paris : Ecole Supérieure de Physique et Chimie Industrielles de Paris, 2006. s. 59-59. [ITP 2006 - International Symposium on Capillary Electroseparation Techniques /15./. 28.08.2006-30.08.2006, Paris] R&D Projects: GA MŠk(CZ) 1M0510; GA ČR(CZ) GA203/05/2539; GA ČR(CZ) GA203/06/1044 Institutional research plan: CEZ:AV0Z50110509 Keywords : dendrimer * capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation

  6. Surface tension in microsystems engineering below the capillary length

    CERN Document Server

    Lambert, Pierre

    2013-01-01

    This book describes how surface tension effects can be used by engineers to provide mechanical functions in miniaturized products (<1 mm). Even if precursors of this field such as Jurin or Laplace already date back to the 18th century, describing surface tension effects from a mechanical perspective is very recent.The originality of this book is to consider the effects of capillary bridges on solids, including forces and torques exerted both statically and dynamically by the liquid along the 6 degrees-of-freedom.It provides a comprehensive approach to various applications, such as capillary ad

  7. Electron acceleration in an ultraintense-laser-illuminated capillary

    International Nuclear Information System (INIS)

    An ultraintense laser injected a 10 J of power at 1.053 μm in 0.5 ps into a glass capillary of 1 cm long and 60 μm in diameter and accelerated plasma electrons to 100 MeV. One- and two-dimensional particle codes describe wakefields with 10 GV/m gradient excited behind the laser pulse, which are guided by a plasma density channel far beyond the Rayleigh range. The blueshift of the laser spectrum supports that a plasma of 1016 cm-3 is inside the capillary. A bump at the high energy tail suggests the electron trapping in the wakefield

  8. Laser-capillary interaction for the EXIN project

    Science.gov (United States)

    Bisesto, F. G.; Anania, M. P.; Bacci, A. L.; Bellaveglia, M.; Chiadroni, E.; Cianchi, A.; Curcio, A.; Di Giovenale, D.; Di Pirro, G.; Ferrario, M.; Galletti, M.; Gallo, A.; Ghigo, A.; Marocchino, A.; Mostacci, A.; Petrarca, M.; Pompili, R.; Rossi, A. R.; Serafini, L.; Vaccarezza, C.

    2016-09-01

    The EXIN project is under development within the SPARC_LAB facility of the National Laboratory of Frascati (LNF-INFN). This project aims to accelerate pre-existing electron bunches with high brightness by exploiting the wakefield plasma acceleration technique, while preserving the initial brightness. The wakefield is excited inside a dielectric capillary by high intensity laser pulses produced by the FLAME laser interacting with a gas. In this work, we present numerical simulations in order to optimize energy coupling between our laser with super-Gaussian transverse profile and a dielectric capillary. Moreover, an overview of the experimental layout will be given.

  9. [Determination of acetochlor and oxyfluorfen by capillary gas chromatography].

    Science.gov (United States)

    Xiang, Wen-Sheng; Wang, Xiang-Jing; Wang, Jing; Wang, Qing

    2002-09-01

    A method is described for the determination of acetochlor and oxyfluorfen by capillary gas chromatography with FID and an SE-30 capillary column (60 m x 0.53 mm i. d., 1.5 microm), using dibutyl phthalate as the internal standard. The standard deviations for acetochlor and oxyfluorfen concentration(mass fraction) were 0.44% and 0.47% respectively. The relative standard deviations for acetochlor and oxyfluorfen were 0.79% and 0.88% and the average recoveries for acetochlor and oxyfluorfen were 99.3% and 101.1% respectively. The method is simple, rapid and accurate. PMID:16358708

  10. Quantum Capillary Waves at the Superfluid—Mott-Insulator Interface

    Science.gov (United States)

    Rath, Steffen Patrick; Spivak, Boris; Zwerger, Wilhelm

    2011-10-01

    We discuss quantum fluctuations of the interface between a superfluid and a Mott-insulating state of ultracold atoms in a trap. The fluctuations of the boundary are due to a new type of surface modes, whose spectrum is similar—but not identical—to classical capillary waves. The corresponding quantum capillary length sets the scale for the penetration of the superfluid into the Mott-insulating regime by the proximity effect and may be on the order of several lattice spacings. It determines the typical magnitude of the interface width due to quantum fluctuations, which may be inferred from single-site imaging of ultracold atoms in an optical lattice.

  11. Capillary electrophoresis and isotachophoresis employed for physicochemical characterization of peptides

    Czech Academy of Sciences Publication Activity Database

    Kašička, Václav; Šolínová, Veronika; Koval, Dušan; Ibrahim, A.; Cottet, H.

    Natal: -, 2014. s. 41. [ITP & LACE 2014. International Symposium on Electro- and Liquid Phase-Separation Techniques /21./ and Latin-American Symposium on Biotechnology, Biomedical, Biopharmaceutical, and Industrial Applications of Capillary Electrophoresis and Microchip Technology /20./. 04.10.2014-08.10.2014, Natal] R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR(CZ) GA13-17224S Grant ostatní: GA AV ČR(CZ) M200551207 Institutional support: RVO:61388963 Keywords : capillary electrophoresis * peptides * electrophoretic mobility Subject RIV: CB - Analytical Chemistry, Separation

  12. Isocratic and gradient separations on sulfoalkylbetaine monolithic capillary column

    Czech Academy of Sciences Publication Activity Database

    Moravcová, Dana; Planeta, Josef; Kahle, Vladislav; Horká, Marie; Roth, Michal

    Messina : Chromaleont S.r.L, 2012 - (Sandra, P.; Mondello, L.). s. 239 [International Symposium on Capillary Chromatography /36./ and GC x GC Symposium /9./. 27.5.2012-01.06.2012, Riva del Garda] R&D Projects: GA MV VG20112015021; GA ČR(CZ) GAP206/11/0138; GA ČR(CZ) GAP106/12/0522 Institutional research plan: CEZ:AV0Z40310501 Keywords : monolithic capillary column * LC separations * Candida parapsilosis Subject RIV: CB - Analytical Chemistry, Separation

  13. Device for rapid transfer of condensable gases into a capillary

    Science.gov (United States)

    Halas, S.; Krouse, H. R.

    1984-07-01

    An inverted bellows-sealed vacuum valve was modified by replacing the Teflon pad on its stem by a stainless-steel dish with a knife-edge circumference and a capillary attached through its center. A Teflon cup for containing liquid air was threaded on top into the valve outlet. With the dish down, condensable gases could be frozen on a small surface area on the bottom of the cup. By pushing the dish upwards so the knife edge pushed into the Teflon, the gas was quantitatively transferred into the capillary upon warming.

  14. Capillary and microchip electrophoretic analysis of polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Ferey, Ludivine; Delaunay, Nathalie

    2015-04-01

    Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants which can reach the environment and food in different ways. Because of their high toxicity, two international regulatory institutions, the US Environmental Protection Agency and the European Food Safety Authority, have classified PAHs as priority pollutants, generating an important demand for the detection and identification of PAHs. Thus, sensitive, fast, and cheap methods for the analysis of PAHs in environmental and food samples are urgently needed. Within this context, electrophoresis, in capillary or microchip format, displays attractive features. This review presents and critically discusses the published literature on the different approaches to capillary and microchip electrophoresis analysis of PAHs. PMID:25542576

  15. Impact of groundwater capillary rises as lower boundary conditions for soil moisture in a land surface model

    Science.gov (United States)

    Vergnes, Jean-Pierre; Decharme, Bertrand; Habets, Florence

    2014-05-01

    Groundwater is a key component of the global hydrological cycle. It sustains base flow in humid climate while it receives seepage in arid region. Moreover, groundwater influences soil moisture through water capillary rise into the soil and potentially affects the energy and water budget between the land surface and the atmosphere. Despite its importance, most global climate models do not account for groundwater and their possible interaction with both the surface hydrology and the overlying atmosphere. This study assesses the impact of capillary rise from shallow groundwater on the simulated water budget over France. The groundwater scheme implemented in the Total Runoff Integrated Pathways (TRIP) river routing model in a previous study is coupled with the Interaction between Soil Biosphere Atmosphere (ISBA) land surface model. In this coupling, the simulated water table depth acts as the lower boundary condition for the soil moisture diffusivity equation. An original parameterization accounting for the subgrid elevation inside each grid cell is proposed in order to compute this fully-coupled soil lower boundary condition. Simulations are performed at high (1/12°) and low (0.5°) resolutions and evaluated over the 1989-2009 period. Compared to a free-drain experiment, upward capillary fluxes at the bottom of soil increase the mean annual evapotranspiration simulated over the aquifer domain by 3.12 % and 1.54 % at fine and low resolutions respectively. This process logically induces a decrease of the simulated recharge from ISBA to the aquifers and contributes to enhance the soil moisture memory. The simulated water table depths are then lowered, which induces a slight decrease of the simulated mean annual river discharges. However, the fully-coupled simulations compare well with river discharge and water table depth observations which confirms the relevance of the coupling formalism.

  16. A fully automated 384 capillary array for DNA sequencer. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qingbo; Kane, T

    2003-03-20

    Phase I SpectruMedix has successfully developed an automatic 96-capillary array DNA prototype based on the multiplexed capillary electrophoresis system originated from Ames Laboratory-USDOE, Iowa State University. With computer control of all steps involved in a 96-capillary array running cycle, the prototype instrument (the SCE9600) is now capable of sequencing 450 base pairs (bp) per capillary, or 48,000 bp per instrument run within 2 hrs. Phase II of this grant involved the advancement of the core 96 capillary technologies, as well as designing a high density 384 capillary prototype. True commercialization of the 96 capillary instrument involved finalization of the gel matrix, streamlining the instrument hardware, creating a more reliable capillary cartridge, and further advancement of the data processing software. Together these silos of technology create a truly commercializable product (the SCE9610) capable of meeting the operation needs of the sequencing centers.

  17. Short capillary tubing as fiber optic sensor of viscosity of liquids

    Science.gov (United States)

    Borecki, Michal; Korwin Pawlowski, Michael L.; Beblowska, Maria; Jakubowski, Andrzej

    2007-05-01

    Optical capillaries are used in capillary gas and liquid chromatography, capillary electrophoresis, absorbance spectroscopy, Raman spectroscopy etc. These micro-fluidic methods find applications in biotechnologies, medical diagnostic, drug discovery and environmental sciences. In the presented work we discuss some aspects of light guidance in capillary tubing made from silica glass or Teflon AF. The wide range of capillary constructions allows them to be used advantageously in specific applications. We have analyzed both theoretically and experimentally partially liquid filled optical capillaries as fiber optic sensor elements in laser light transmission and reflection conditions at 670, 1310 and 1550 nm. We have shown that the light transmission properties and signal in the reflectometric mode of work depend on capillary construction, their length and position of inserted liquid drop. The results obtained by us show that capillary tubing can be used as sensing elements in optical fiber sensors of surface tension and viscosity of small liquid samples with volume below 10 -8 cm 3.

  18. Ergot alkaloids as chiral selectors in capillary electrophoresis and other electromigration methods

    Czech Academy of Sciences Publication Activity Database

    Sinibaldi, M.; Messina, A.; Stodůlková, Eva; Flieger, Miroslav

    2010-01-01

    Roč. 1, č. 3 (2010), s. 233-243. ISSN 0976-5514 Institutional research plan: CEZ:AV0Z50200510 Keywords : capillary electrophoresis * capillary electrochromatography * chiral analysis Subject RIV: CB - Analytical Chemistry, Separation

  19. Monitoring antigenic protein integrity during glycoconjugate vaccine synthesis using capillary electrophoresis-mass spectrometry.

    Science.gov (United States)

    Tengattini, Sara; Domínguez-Vega, Elena; Temporini, Caterina; Terreni, Marco; Somsen, Govert W

    2016-09-01

    A capillary electrophoresis-mass spectrometry (CE-MS) method was developed for the characterization and integrity assessment of the Mycobacterium tuberculosis (MTB) antigens TB10.4 and Ag85B and their chemically produced glycoconjugates, which are glycovaccine candidates against tuberculosis (TB). In order to prevent protein adsorption to the inner capillary wall and to achieve efficient separation of the antigen proteoforms, a polyionic multilayer coating of polybrene-dextran sulfate-polybrene (PB-DS-PB) was used in combination with 1.5 M acetic acid as background electrolyte (BGE). Coupling of CE to high-resolution time-of-flight MS was achieved by a coaxial interface employing a sheath liquid of isopropanol-water (50:50, v/v) containing 0.1 % formic acid. The MTB antigens were exposed to experimental conditions used for chemical glycosylation (but no activated saccharide was added) in order to investigate their stability during glycovaccine production. CE-MS analysis revealed the presence of several closely related degradation products, including truncated, oxidized and conformational variants, which were assigned by accurate mass. Analysis of synthesized mannose conjugates of TB10.4 and Ag85B allowed the determination of the glycoform composition of the neo-glycoproteins next to the characterization of degradation products which were shown to be partly glycoconjugated. Moreover, the selectivity of CE-MS allowed specific detection of deamidated species (protein mass change of 1.0 Da only), indicating that chemical glycosylation increased susceptibility to deamidation. Overall, the results show that CE-MS represents a useful analytical tool for the detailed characterization and optimization of neo-glycoconjugate products. Graphical Abstract Flowchart illustrating Mycobacterium tuberculosis (MTB) antigen glycosylation, glycoconjugate variant and degradation product separation by capillary electrophoresis (CE) and their characterization by intact mass

  20. Single-bead arrays for fluorescence-based immunoassays on capillary-driven microfluidic chips

    Science.gov (United States)

    Temiz, Yuksel; Lim, Michel; Delamarche, Emmanuel

    2016-03-01

    We report a concept for the simple fabrication of easy-to-use chips for immunoassays in the context of point-of-care diagnostics. The chip concept comprises mainly three features: (1) the efficient integration of reagents using beads functionalized with receptors, (2) the generation of capillary-driven liquid flows without using external pumps, and (3) a high-sensitivity detection of analytes using fluorescence microscopy. We fabricated prototype chips using dry etching of Si wafers. 4.5-μm-diameter beads were integrated into hexagonal arrays by sedimentation and removing the excess using a stream of water. We studied the effect of different parameters and showed that array occupancies from 30% to 50% can be achieved by pipetting a 250 nL droplet of 1% bead solution and allowing the beads sediment for 3 min. Chips with integrated beads were sealed using a 50-μm-thick dry-film resist laminated at 45 °C. Liquids pipetted to loading pads were autonomously pulled by capillary pumps at a rate of 0.35 nL s-1 for about 30 min. We studied ligand-receptor interactions and binding kinetics using time-lapse fluorescence microscopy and demonstrated a 5 pM limit of detection (LOD) for an anti-biotin immunoassay. As a clinically-relevant example, we implemented an immunoassay to detect prostate specific antigen (PSA) and showed an LOD of 108 fM (i.e. 3.6 pg mL-1). While a specific implementation is provided here for the detection of PSA, we believe that combining capillary-driven microfluidics with arrays of single beads and fluorescence readout to be very flexible and sufficiently sensitive for the detection of other clinically-relevant analytes.