WorldWideScience

Sample records for capillary tube formation

  1. 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

  2. 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/

  3. 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

  4. 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

  5. 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...

  6. 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.

  7. 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)

  8. 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.

  9. 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.

  10. Electropolishing the bore of metal capillary tubes: A technique for adjusting the critical flow.

    Science.gov (United States)

    Stoffels, J J; Ells, D R

    1979-12-01

    A technique has been developed for electropolishing the bore of metal capillary tubes. Although developed specifically for stainless-steel tubes, the technique should be directly applicable to other metals. Tubes with inside diameter as small as 0.20 mm and 110 mm long have been successfully electropolished. The electropolishing technique can be used to increase the critical flow of a capillary tube in a controllable way. PMID:18699437

  11. Investigation of pressure drop in capillary tube for mixed refrigerant Joule-Thomson cryocooler

    International Nuclear Information System (INIS)

    A capillary tube is commonly used in small capacity refrigeration and air-conditioning systems. It is also a preferred expansion device in mixed refrigerant Joule-Thomson (MR J-T) cryocoolers, since it is inexpensive and simple in configuration. However, the flow inside a capillary tube is complex, since flashing process that occurs in case of refrigeration and air-conditioning systems is metastable. A mixture of refrigerants such as nitrogen, methane, ethane, propane and iso-butane expands below its inversion temperature in the capillary tube of MR J-T cryocooler and reaches cryogenic temperature. The mass flow rate of refrigerant mixture circulating through capillary tube depends on the pressure difference across it. There are many empirical correlations which predict pressure drop across the capillary tube. However, they have not been tested for refrigerant mixtures and for operating conditions of the cryocooler. The present paper assesses the existing empirical correlations for predicting overall pressure drop across the capillary tube for the MR J-T cryocooler. The empirical correlations refer to homogeneous as well as separated flow models. Experiments are carried out to measure the overall pressure drop across the capillary tube for the cooler. Three different compositions of refrigerant mixture are used to study the pressure drop variations. The predicted overall pressure drop across the capillary tube is compared with the experimentally obtained value. The predictions obtained using homogeneous model show better match with the experimental results compared to separated flow models

  12. 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.

  13. 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.

  14. Optimized transcritical CO{sub 2} heat pumps: Performance comparison of capillary tubes against expansion valves

    Energy Technology Data Exchange (ETDEWEB)

    Agrawal, Neeraj; Bhattacharyya, Souvik [Department of Mechanical Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India)

    2008-05-15

    A capillary tube based CO{sub 2} heat pump is unique because of the transcritical nature of the system. The transcritical cycle has two independent parameters, pressure and temperature, unlike the subcritical cycle. In the present study, a steady state simulation model has been developed to evaluate the performance of a capillary tube based transcritical CO{sub 2} heat pump system for simultaneous heating and cooling at 73 C and 4 C, respectively against optimized expansion valve systems. Capillary tubes of various configurations having diameters of 1.4, 1.5 and 1.6 mm along with internal surface roughness of 0.001-0.003 mm have been tested to obtain the optimum design and operating conditions. Subcritical and supercritical thermodynamic and transport properties of CO{sub 2} are calculated employing a precision in-house property code. It is observed that the capillary tube system is quite flexible in response to changes in ambient temperature, almost behaving to offer an optimal pressure control. System performance is marginally better with a capillary tube at higher gas cooler exit temperature. Capillary tube length turns out to be the critical parameter that influences system optimum conditions. A novel nomogram has been developed that can be employed as a guideline to select the optimum capillary tube. (author)

  15. Superparamagnetic particle dynamics and mixing in a rotating capillary tube with a stationary magnetic field.

    Science.gov (United States)

    Lee, Jun-Tae; Abid, Aamir; Cheung, Ka Ho; Sudheendra, L; Kennedy, Ian M

    2012-09-01

    The dynamics of superparamagnetic particles subject to competing magnetic and viscous drag forces have been examined with a uniform, stationary, external magnetic field. In this approach, competing drag and magnetic forces were created in a fluid suspension of superparamagnetic particles that was confined in a capillary tube; competing viscous drag and magnetic forces were established by rotating the tube. A critical Mason number was determined for conditions under which the rotation of the capillary prevents the formation of chains from individual particles. The statistics of chain length were investigated by image analysis while varying parameters such as the rotation speed and the viscosity of the liquid. The measurements showed that the rate of particle chain formation was decreased with increased viscosity and rotation speed ; the particle dynamics could be quantified by the same dimensionless Mason number that has been demonstrated for rotating magnetic fields. The potential for enhancement of mixing in a bioassay was assessed using a fast chemical reaction that was diffusion-limited. Reducing the Mason below the critical value, so that chains were formed in the fluid, gave rise to a modest improvement in the time to completion of the reaction. PMID:23066382

  16. Visualization and void fraction measurement of decompressed boiling flow in a capillary tube

    International Nuclear Information System (INIS)

    A capillary tube is often used as a throttle for a refrigerating cycle. Subcooled refrigerant usually flows from a condenser into the capillary tube. Then, the refrigerant is decompressed along the capillary tube. When the static pressure falls below the saturation pressure for the liquid temperature, spontaneous boiling occurs. A vapor-liquid two-phase mixture is discharged from the tube. In designing a capillary tube, it is necessary to calculate the flow rate for given boundary conditions on pressure and temperature at the inlet and exit. Since total pressure loss is dominated by frictional and acceleration losses during two-phase flow, it is first necessary to specify the boiling inception point. However, there will be a delay in boiling inception during decompressed flow. This study aimed to clarify the boiling inception point and two-phase flow characteristics of refrigerant in a capillary tube. Refrigerant flows in a coiled copper capillary tube were visualized by neutron radiography. The one-dimensional distribution of volumetric average void fraction was measured from radiographs through image processing. From the void fraction distribution, the boiling inception point was determined. Moreover, a simplified CT method was successfully applied to a radiograph for cross-sectional measurements. The experimental results show the flow pattern transition from intermittent flow to annular flow that occurred at a void fraction of about 0.45.

  17. Visualization and void fraction measurement of decompressed boiling flow in a capillary tube

    Science.gov (United States)

    Asano, H.; Murakawa, H.; Takenaka, N.; Takiguchi, K.; Okamoto, M.; Tsuchiya, T.; Kitaide, Y.; Maruyama, N.

    2011-09-01

    A capillary tube is often used as a throttle for a refrigerating cycle. Subcooled refrigerant usually flows from a condenser into the capillary tube. Then, the refrigerant is decompressed along the capillary tube. When the static pressure falls below the saturation pressure for the liquid temperature, spontaneous boiling occurs. A vapor-liquid two-phase mixture is discharged from the tube. In designing a capillary tube, it is necessary to calculate the flow rate for given boundary conditions on pressure and temperature at the inlet and exit. Since total pressure loss is dominated by frictional and acceleration losses during two-phase flow, it is first necessary to specify the boiling inception point. However, there will be a delay in boiling inception during decompressed flow. This study aimed to clarify the boiling inception point and two-phase flow characteristics of refrigerant in a capillary tube. Refrigerant flows in a coiled copper capillary tube were visualized by neutron radiography. The one-dimensional distribution of volumetric average void fraction was measured from radiographs through image processing. From the void fraction distribution, the boiling inception point was determined. Moreover, a simplified CT method was successfully applied to a radiograph for cross-sectional measurements. The experimental results show the flow pattern transition from intermittent flow to annular flow that occurred at a void fraction of about 0.45.

  18. An Experimental Comparison of the Refrigerant Flow through Adiabatic and Non-Adiabatic Helical Capillary Tubes

    OpenAIRE

    Javidmand, Puya; Zareh, Masoud

    2014-01-01

    Capillary tubes are used as refrigerant controlling devices, expansion devices and also as heart of a small vapor compression refrigeration cycle. It connects outlet condenser to the inlet evaporator and balances the refrigeration cycle pressure and controls the refrigerant mass flux. Capillary tubes are relatively cheap, resulting in extensive implementations in small household refrigerators and freezers with nearly constant refrigeration load. In general, the inner diameter and length of a ...

  19. An Optical Fiber Viscometer Based on Long-Period Fiber Grating Technology and Capillary Tube Mechanism

    OpenAIRE

    Jian-Neng Wang; Jaw-Luen Tang

    2010-01-01

    This work addresses the development and assessment of a fiber optical viscometer using a simple and low-cost long-period fiber grating (LPFG) level sensor and a capillary tube mechanism. Previous studies of optical viscosity sensors were conducted by using different optical sensing methods. The proposed optical viscometer consists of an LPFG sensor, a temperature-controlled chamber, and a cone-shaped reservoir where gravitational force could cause fluid to flow through the capillary tube. We ...

  20. The Effect of the Capillary Tube Coil Number on the Refrigeration System Performance

    OpenAIRE

    Thamir K. Salim

    2012-01-01

    The capillary tube performance for (R134a) is experimentally investigated. The experimental setup is a real vapor compression refrigeration system. All properties of the refrigeration system are measured for various mass flow rate from (13 – 23 kg/hr) and capillary tube coil number (0-4) with fixed length (150 cm) and capillary diameter(2.5mm).The results showed that the theoretical compression power increases by (65.8 %) as the condenser temperature increases by (2.71%), also the theoretical...

  1. Tube Formation in Nanoscale Materials

    Directory of Open Access Journals (Sweden)

    Yan Chenglin

    2008-01-01

    Full Text Available Abstract The formation of tubular nanostructures normally requires layered, anisotropic, or pseudo-layered crystal structures, while inorganic compounds typically do not possess such structures, inorganic nanotubes thus have been a hot topic in the past decade. In this article, we review recent research activities on nanotubes fabrication and focus on three novel synthetic strategies for generating nanotubes from inorganic materials that do not have a layered structure. Specifically, thermal oxidation method based on gas–solid reaction to porous CuO nanotubes has been successfully established, semiconductor ZnS and Nb2O5nanotubes have been prepared by employing sacrificial template strategy based on liquid–solid reaction, and an in situ template method has been developed for the preparation of ZnO taper tubes through a chemical etching reaction. We have described the nanotube formation processes and illustrated the detailed key factors during their growth. The proposed mechanisms are presented for nanotube fabrication and the important pioneering studies are discussed on the rational design and fabrication of functional materials with tubular structures. It is the intention of this contribution to provide a brief account of these research activities.

  2. New empirical correlations for sizing adiabatic capillary tubes in refrigeration systems

    Science.gov (United States)

    Shodiya, S.; Aahar, A. A.; Henry, N.; Darus, A. N.

    2012-06-01

    This paper presents new empirical correlations that have been developed for sizing adiabatic capillary tubes used in small vapor compression refrigeration and air-conditioning systems. A numerical model which is based on the basic equations of conservation of mass, momentum and energy was developed. Colebrook's formulation was used to determine the single phase friction factor. The two-phase viscosity models - Cicchitti et al., Dukler et al. and McAdam et al. were used based on the recommendation from literature to determine the two-phase viscosity factor. The developed numerical model was validated using the experimental data from literature. The numerical model was used to study the effects of relevant parameters on capillary tube length and the results showed that the length of capillary tube increase with increase in condensing temperature, subcooling, and inner diameter of tube but decrease with increase in surface roughness and mass flow rate. Thereafter, empirical correlation of the capillary tube length with the five dependent variables was presented. The empirical models are validated using experimental data from literature. Different from the previous studies, the empirical models have a large set of refrigerants and wide operating conditions. The developed correlation can be used as an effective tool for sizing adiabatic capillary tube with system models working with alternative refrigerants.

  3. 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.

  4. The Effect of the Capillary Tube Coil Number on the Refrigeration System Performance

    Directory of Open Access Journals (Sweden)

    Thamir K. Salim

    2012-06-01

    Full Text Available The capillary tube performance for (R134a is experimentally investigated. The experimental setup is a real vapor compression refrigeration system. All properties of the refrigeration system are measured for various mass flow rate from (13 – 23 kg/hr and capillary tube coil number (0-4 with fixed length (150 cm and capillary diameter(2.5mm.The results showed that the theoretical compression power increases by (65.8 % as the condenser temperature increases by (2.71%, also the theoretical compression power decreases by (10.3 % as the capillary tube coil number increases.The study shows also that the cooling capacity increases by (65.3% as the evaporator temperature increases by (8.4 %, and the cooling capacity increases by (1.6%as the capillary tube coil number increases in the range (0-4.The coefficient of performance decreases by (43.4 %, as the mass flow rateincreases by (76.9%, also the coefficient of performance increases by (13.51 % as thecapillary tube coil number increases in the range (0-4.Through this study, it was found that the best coil number in refrigeration cycle at the lowest mass flow rate (31 Kg/hr and at high mass flow rate (23 Kg/hr is (coil number = 4, this will give the highest performance, cooling capacity and lowest theoretical compression power.

  5. Analytical modeling of capillary flow in tubes of nonuniform cross section.

    Science.gov (United States)

    Liou, William W; Peng, Yongqing; Parker, Peter E

    2009-05-01

    The interface rise for the flow in a capillary with a nonuniform cross section distribution along a straight center axis is investigated analytically in this paper. Starting from the Navier-Stokes equations, we derive a model equation for the time-dependent rise of the capillary interface by using an approximated three-dimensional flow velocity profiles. The derived nonlinear, second-order differential equation can be solved numerically using the Runge-Kutta method. The nonuniformity effect is included in the inertial and viscous terms of the proposed model. The present model is validated by comparing the solutions for a circular cylindrical tube, rectangular cylindrical microchannels, and convergent-divergent and divergent-convergent capillaries. The validated model has been applied to capillaries with parabolic varying wall, sinusoidal wall, and divergent sinusoidal wall. The inertial and viscous effects on the dynamic capillary rise and the equilibrium height are investigated in detail. PMID:19232635

  6. Low-Reynolds number swimming in a capillary tube

    CERN Document Server

    Zhu, Lailai; Brandt, Luca

    2013-01-01

    We use the boundary element method to study the low-Reynolds number locomotion of a spherical model microorganism in a circular tube. The swimmer propels itself by tangen- tial or normal surface motion in a tube whose radius is on the order of the swimmer size. Hydrodynamic interactions with the tube walls significantly affect the average swimming speed and power consumption of the model microorganism. In the case of swimming parallel to the tube axis, the locomotion speed is always reduced (resp. increased) for swimmers with tangential (resp. normal) deformation. In all cases, the rate of work nec- essary for swimming is increased by confinement. Swimmers with no force-dipoles in the far field generally follow helical trajectories, solely induced by hydrodynamic interactions with the tube walls, and in qualitative agreement with recent experimental observations for Paramecium. Swimmers of the puller type always display stable locomotion at a lo- cation which depends on the strength of their force dipoles: sw...

  7. Microfluidic and Capillary Tube Experimental Study of Forsterite Carbonation by CO2 Bearing Fluids

    Science.gov (United States)

    Yang, L.; Steefel, C. I.; Bechtel, H.

    2013-12-01

    .D capillary tube reactors at 95 C and 100 bars to simulate the coupled flow (the primary channel) and diffusion-only processes in the subsurface. The experiments demonstrated that no secondary carbonate minerals formed in the flow channel, as expected due to the high flushing rate. However, significant amounts of magnesite did form in the diffusion-controlled capillary tube reactor where the pH, alkalinity, and Mg2+ concentration had risen sufficiently high to allow magnesite precipitation. The profile of the magnesite precipitated along the diffusion reactor was quantified with RAMAN spectroscopy analysis and was interpreted with multicomponent reactive transport modeling to gain further insights on the secondary magnesite nucleation and growth kinetics. The experimental studies revealed that secondary carbonate formation, while thermodynamically inhibited in the main flow channel due to the low pH, could still occur in local micro-environments characterized by diffusion-controlled transport conditions. This highlights the importance of local heterogeneities in controlling minerals carbonation reactions in the subsurface during geological carbon sequestration.

  8. Propulsion by a Helical Flagellum in a Capillary Tube

    CERN Document Server

    Liu, Bin; Powers, Thomas R

    2014-01-01

    We study the microscale propulsion of a rotating helical filament confined by a cylindrical tube, using a boundary-element method for Stokes flow that accounts for helical symmetry. We determine the effect of confinement on swimming speed and power consumption. Except for a small range of tube radii at the tightest confinements, the swimming speed at fixed rotation rate increases monotonically as the confinement becomes tighter. At fixed torque, the swimming speed and power consumption depend only on the geometry of the filament centerline, except at the smallest pitch angles for which the filament thickness plays a role. We find that the `normal' geometry of \\textit{Escherichia coli} flagella is optimized for swimming efficiency, independent of the degree of confinement. The efficiency peaks when the arc length of the helix within a pitch matches the circumference of the cylindrical wall. We also show that a swimming helix in a tube induces a net flow of fluid along the tube.

  9. Based on MDCE to simulate bell-shaped interferograms produced by a capillary tube interferometer

    International Nuclear Information System (INIS)

    The vector theory to calculate the optical path length (OPL) of the rays passing through a capillary tube was given and the OPLs including the collimated lens in 3D space were calculated, the interferograms produced by the capillary tube were simulated. A pinhole localized at the focal point of the collimated lens was seen as a point source of light. Based on ray-tracing, the OPL distribution from the point source of light, passing by the collimated lens, a cylindrical lens, the capillary tube and a screen was calculated. Because the huge calculation in the ray-tracing, a distributed calculating net based on MATLAB Distributed Computing Engine (MDCE) was established to save time. In order to get the simulated interferograms from the envelope of the OPLs, Delaunay triangulation algorithm and cubic spline interpolation were used. We record the interferograms of the capillary tube filled with liquids with different refractive indices and compared with the simulated interferograms. The results showed the two coincided well.

  10. Chromatic dispersion of liquid crystal infiltrated capillary tubes and photonic crystal fibers

    DEFF Research Database (Denmark)

    Rasmussen, Per Dalgaard; Lægsgaard, Jesper; Bang, Ole

    2006-01-01

    We consider chromatic dispersion of capillary tubes and photonic crystal fibers infiltrated with liquid crystals. A perturbative scheme for inclusion of material dispersion of both liquid crystal and the surrounding waveguide material is derived. The method is used to calculate the chromatic...

  11. Tube Formation in Nanoscale Materials

    OpenAIRE

    Yan Chenglin; Liu Jun; Liu Fei; Wu Junshu; Gao Kun; Xue Dongfeng

    2008-01-01

    Abstract The formation of tubular nanostructures normally requires layered, anisotropic, or pseudo-layered crystal structures, while inorganic compounds typically do not possess such structures, inorganic nanotubes thus have been a hot topic in the past decade. In this article, we review recent research activities on nanotubes fabrication and focus on three novel synthetic strategies for generating nanotubes from inorganic materials that do not have a layered structure. Specifically, thermal ...

  12. Fission-fragment attachment to aerosols and their transport through capillary tubes

    International Nuclear Information System (INIS)

    The transport of radioactive aerosols was studied using equipment, collectively called the Helium jet, that has been constructed to provide basic nuclear physics data on fission product nuclides. The transport of the fission products in the system depends on their attachment to aerosol particles. The system consists of 1) a tube furnace which generates aerosols by the sublimation or evaporation of source material, 2) a helium stream used to transport the aerosols, 3) a 25 m settling tube to eliminate the larger aerosols and smaller aerosols that would deposit in the capillary, 4) a Californium-252 self-fissioning source of fission product nuclides, and 5) a small capillary to carry the radioactive aerosols from the hot cell to the laboratory. Different source materials were aerosolized but NaCl is generally used because it yielded the highest transport efficiencies through the capillary. Particle size measurments were made with NaCl aerosols by using a cascade impactor, an optical light scattering device, and the capillary itself as a diffusion battery by performing radiation measurements and/or electrical conductivity measurements. Both radioactive and nonradioactive aerosols were measured in order to investigate the possibility of a preferential size range for fission product attachment. The measured size distributions were then used to calculate attachment coefficients and finally an attachment time

  13. Visualization of the Refrigerant Flow at the Capillary Tube Inlet of a Houseold Refrigeration System

    OpenAIRE

    Martinez-Ballester, Santiago; Bardoulet, Laetitia; Pisano, Alessandro; Bordes-Costa, José M.; Corberán, José M.

    2014-01-01

    Capillary tube-suction line heat exchangers (CT-SLHX) introduce complex phenomena due to simultaneous 2-phase flow expansion and heat transfer such as: reverse heat transfer, flow hysteresis and flow oscillations. Some of the negative consequences of these phenomena are: noise due to re-condensation, which is becoming an important quality issue; and reduction of the SLHX effectiveness, which also affects the global efficiency. Studies about how to solve the noise problem show that it disappea...

  14. Theoretical Design of adiabatic capillary tube of a domestic refrigerator using refrigerant R-600a.

    Directory of Open Access Journals (Sweden)

    Sahoo. K. C

    2016-08-01

    Full Text Available This paper develops a more accurate theoretical procedure for the design of adiabatic capillary tube of a domestic refrigerator considering a rigorous pressure drop analysis on the refrigerant R-600a while expanding through that tube accompanied with phase change through flash vaporization. Here this eliminates the contradiction of existing concepts on the negative value of the frictional pressure drop after a short distance of expansion due to a large part contribution of the actual pressure drop towards the momentum gain pressure drop. Also this verifies that the momentum gain through phase change is by consumption of internal energy part of the enthalpy and no part of the actual pressure drop energy is used in this respect. So with the concept of nearly total pressure drop being used in overcoming the friction the design of an adiabatic capillary tube of available I mm diameter for 0.1 ton refrigeration capacity has been carried out here. This design procedure causes some increase in the required length of the capillary for a given refrigeration capacity due to the omission of momentum pressure drop concept of different references, but is more accurate with consideration of actual changes involved in the expansion. The procedure is applicable for any other refrigerant of any refrigeration capacity

  15. Available energy analysis of new tandem double-capillary tube refrigeration system for refrigerator-freezers

    Institute of Scientific and Technical Information of China (English)

    Maogang HE; Xinzhou SONG; Ying ZHANG; Jiantao ZHANG

    2008-01-01

    A new tandem double-capillary tube refri-geration system for refrigerator-freezers is proposed. A capillary tube was added between the two evaporators in the fresh and frozen food storage chests to raise the evaporation temperature of the refrigerating chamber, and reduce the heat exchange temperature difference and the available energy loss. Peng-Robinson (P-R) equation of state was adopted to calculate the thermodynamic properties of the refrigerants, and the available energy analysis of the vapor compression refrigeration cycle was programmed to calculate the thermodynamic perfor-mances of the new and the conventional refrigeration cycle of the refrigerator-freezer. The calculation results show that the available energy efficiency of the conven-tional refrigeration cycle of the refrigerator-freezer is 21.20% and 20.57%, respectively when the refrigerant is R12 and R134a, while that of the double-capillary tube refrigeration cycle of the refrigerator-freezer is 23.97% and 23.44%, respectively. By comparison, the available energy efficiency of the new refrigeration system increases by 13.07% and 13.95%, respectively.

  16. Measurement of tear glucose levels with amperometric glucose biosensor/capillary tube configuration.

    Science.gov (United States)

    Yan, Qinyi; Peng, Bo; Su, Gang; Cohan, Bruce E; Major, Terry C; Meyerhoff, Mark E

    2011-11-01

    An amperometric needle-type electrochemical glucose sensor intended for tear glucose measurements is described and employed in conjunction with a 0.84 mm i.d. capillary tube to collect microliter volumes of tear fluid. The sensor is based on immobilizing glucose oxidase on a 0.25 mm o.d. platinum/iridium (Pt/Ir) wire and anodically detecting the liberated hydrogen peroxide from the enzymatic reaction. Inner layers of Nafion and an electropolymerized film of 1,3-diaminobenzene/resorcinol greatly enhance the selectivity for glucose over potential interferences in tear fluid, including ascorbic acid and uric acid. Further, the new sensor is optimized to achieve very low detection limits of 1.5 ± 0.4 μM of glucose (S/N = 3) that is required to monitor glucose levels in tear fluid with a glucose sensitivity of 0.032 ± 0.02 nA/μM (n = 6). Only 4-5 μL of tear fluid in the capillary tube is required when the needle sensor is inserted into the capillary. The glucose sensor was employed to measure tear glucose levels in anesthetized rabbits over an 8 h period while also measuring the blood glucose values. A strong correlation between tear and blood glucose levels was found, suggesting that measurement of tear glucose is a potential noninvasive substitute for blood glucose measurements, and the new sensor configuration could aid in conducting further research in this direction. PMID:21961809

  17. Acoustic wave detection of chemical species electrokinetically transported within a capillary tube.

    Science.gov (United States)

    Li, Paul C H; Prasad, Ronald

    2003-06-01

    For the first time, we report the acoustic wave detection of chemical species being transported in a capillary tube to a region where acoustic coupling occurs. The measured parameter was a change in phase, which was originally only attributed to a change in solution density as the analyte passed by the detection region. Accordingly, we report the detection of change in phase as various chemical species (e.g. Cy5 dye, Cy5-derivatized glycine and underivatized glycine) were introduced into and migrated along a capillary tube through electrokinetic processes. To improve detection sensitivity, we modified various experimental parameters, such as run buffer concentration, capillary wall thickness and transducer frequency. Although acoustic wave detection was feasible, the peak width and detection limit were inadequate as compared to conventional detection methods for HPLC or CE. Nevertheless, the effects of various physical and chemical relaxation processes on acoustic wave absorption were discussed, and this has shed some light on explaining some observations, which cannot be explained by density differences alone. Accordingly, the acoustic wave method is suggested to investigate these processes, as studied in ultrasonic relaxation spectroscopy, in a flow system. PMID:12866892

  18. Analysis of Capillary Tube Sludge in Refrigeration Circuit with HFC 134 a

    Science.gov (United States)

    Nakayama, Yoshinori; Yamamoto, Thutomu; Takahashi, Yuuichi; Shimizu, Yasuhiko; Takizawa, Kikuo; Yamasita, Tsugito

    We conducted a continuous test with a refrigeration test circuit using HFC 134 a,and we made a study of the form and components of the sludge inside the capillary tube comparing different kinds of lubricant from this perspective. A rotary compressor was used for the test, and HAB oil, blended oil and ester oil were employed as the lubricants. The results showed that the capillary sludge consists mainly of a copper oxide which is caused by corrosion in the case of the HAB oil, and mainly a metal soap, a decomposition product and polymeric product of the lubricant, and zeolite in the case of the ester oil. In order to decrease the amount of these sludges, it is necessary, in the former case, to remove the remaining chlorine solvents and other impurities in the constituent parts of the refrigeration test circuit and, in the latter case, to develop a stabler lubricant and zeolite. In the case of the blended oil, we discovered that zeolite and ohter substances are deposited in the capillary tube over the course of time.

  19. Semiquantitative determination of some nitrogen compounds by the formation of charge-transfer complexes of diphenylamine with p-dimethylaminobenzaldehyde by capillary solid-state spot-tests

    Institute of Scientific and Technical Information of China (English)

    Ishaat; M.Khan

    2010-01-01

    The interactions of p-dimethylaminobenzaldehyde (p-DAB) and potassium hydrogen sulphate (PHS) in equimolar ratio with various concentration of diphenylamine (solid test material) have been investigated by capillary spot-tests technique in order to investigate the effect of temperature and volume of material in test-tube. The formation of the colored boundary in the capillary is taken for the detection of organic compounds by spot-tests at different temperature and volume of solid test material.

  20. Mass flow rate correlation for two-phase flow of R218 through a capillary tube

    Czech Academy of Sciences Publication Activity Database

    Vinš, Václav; Vacek, V.

    2009-01-01

    Roč. 29, 14-15 (2009), s. 2816-2823. ISSN 1359-4311 Institutional research plan: CEZ:AV0Z20760514 Keywords : artificial neural network * capillary tube * mass flow rate correlation * R218 Subject RIV: BK - Fluid Dynamics Impact factor: 1.922, year: 2009 http://www.sciencedirect.com/science?_ob=PublicationURL&_cdi=5687&_pubType=J&_acct=C000034318&_version=1&_urlVersion=0&_userid=640952&md5=fc314a471a010545ee185394a6c8f5f7&jchunk=29#29

  1. Thermal performance of capillary micro tubes integrated into the sandwich element made of concrete

    DEFF Research Database (Denmark)

    Mikeska, Tomas; Svendsen, Svend

    2013-01-01

    The thermal performance of radiant heating and cooling systems (RHCS) composed of capillary micro tubes (CMT) integrated into the inner plate of sandwich elements made of High Performance Concrete (HPC) was investigated in the article. Temperature distribution in HPC elements around integrated CMT...... integrated into the thin plate of sandwich element made of HPC can supply the energy needed for heating and cooling. The investigations were conceived as a low temperature concept, where the difference between the temperature of circulating fluid and air in the room was kept in range of 1 to 4°C. © (2013...

  2. Circumventing Imprecise Geometric Information and Development of a Unified Modeling Technique for Various Flow Regimes in Capillary Tubes

    Science.gov (United States)

    Abbasi, Bahman

    2012-11-01

    Owing to their manufacturability and reliability, capillary tubes are the most common expansion devices in household refrigerators. Therefore, investigating flow properties in the capillary tubes is of immense appeal in the said business. The models to predict pressure drop in two-phase internal flows invariably rely upon highly precise geometric information. The manner in which capillary tubes are manufactured makes them highly susceptible to geometric imprecisions, which renders geometry-based models unreliable to the point of obsoleteness. Aware of the issue, manufacturers categorize capillary tubes based on Nitrogen flow rate through them. This categorization method presents an opportunity to substitute geometric details with Nitrogen flow data as the basis for customized models. The simulation tools developed by implementation of this technique have the singular advantage of being applicable across flow regimes. Thus the error-prone process of identifying compatible correlations is eliminated. Equally importantly, compressibility and chocking effects can be incorporated in the same model. The outcome is a standalone correlation that provides accurate predictions, regardless of any particular fluid or flow regime. Thereby, exploratory investigations for capillary tube design and optimization are greatly simplified. Bahman Abbasi, Ph.D., is Lead Advanced Systems Engineer at General Electric Appliances in Louisville, KY. He conducts research projects across disciplines in the household refrigeration industry.

  3. Specific Accumulation of Tumor-Derived Adhesion Factor in Tumor Blood Vessels and in Capillary Tube-Like Structures of Cultured Vascular Endothelial Cells

    Science.gov (United States)

    Akaogi, Kotaro; Okabe, Yukie; Sato, Junji; Nagashima, Yoji; Yasumitsu, Hidetaro; Sugahara, Kazuyuki; Miyazaki, Kaoru

    1996-08-01

    Tumor-derived adhesion factor (TAF) was previously identified as a cell adhesion molecule secreted by human bladder carcinoma cell line EJ-1. To elucidate the physiological function of TAF, we examined its distribution in human normal and tumor tissues. Immunochemical staining with an anti-TAF monoclonal antibody showed that TAF was specifically accumulated in small blood vessels and capillaries within and adjacent to tumor nests, but not in those in normal tissues. Tumor blood vessel-specific staining of TAF was observed in various human cancers, such as esophagus, brain, lung, and stomach cancers. Double immunofluorescent staining showed apparent colocalization of TAF and type IV collagen in the vascular basement membrane. In vitro experiments demonstrated that TAF preferentially bound to type IV collagen among various extracellular matrix components tested. In cell culture experiments, TAF promoted adhesion of human umbilical vein endothelial cells to type IV collagen substrate and induced their morphological change. Furthermore, when the endothelial cells were induced to form capillary tube-like structures by type I collagen, TAF and type IV collagen were exclusively detected on the tubular structures. The capillary tube formation in vitro was prevented by heparin, which inhibited the binding of TAF to the endothelial cells. These results strongly suggest that TAF contributes to the organization of new capillary vessels in tumor tissues by modulating the interaction of endothelial cells with type IV collagen.

  4. Evaluation of Carbon Nanotubes Functionalized Polydimethylsiloxane Based Coatings for In-Tube Solid Phase Microextraction Coupled to Capillary Liquid Chromatography

    OpenAIRE

    Neus Jornet-Martínez; Pascual Serra-Mora; Yolanda Moliner-Martínez; Rosa Herráez-Hernández; Pilar Campíns-Falcó

    2015-01-01

    In the present work, the performance of carbon nanotubes (c-CNTs) functionalized polydimethylsiloxane (PDMS) based coatings as extractive phases for in-tube solid phase microextraction (IT-SPME) coupled to Capillary LC (CapLC) has been evaluated. Carboxylic-single walled carbon nanotubes (c-SWNTs) and carboxylic-multi walled carbon nanotubes (c-MWNTs) have been immobilized on the activated surface of PDMS capillary columns. The effect of different percentages of diphenyl groups in the PDMS ex...

  5. 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.

  6. MDA-MB-231细胞源exosome对人脐静脉内皮细胞(HUVEC)VEGF自分泌及体外成管作用的影响%Effects of exosomes derived from MDA-MB-231 on the expression of autocrine VEGF and capillary-like tube formation in HUVECs

    Institute of Scientific and Technical Information of China (English)

    隆霜; 沈宜; 谢莹珊; 范维珂; 姜蓉; 陈黎

    2012-01-01

    目的 研究人乳腺癌MDA-MB-231细胞源exosome对人脐静脉内皮细胞(human umbilical vein endothelial cell,HUVEC)血管内皮生长因子(vascular endothelial growth factor,VEGF)自分泌及体外成管作用的影响,探讨肿瘤细胞源exosome在肿瘤微环境中对血管内皮细胞血管生成的调控作用.方法 低温超速离心及密度梯度离心法提取乳腺癌MDA-MB-231细胞源exosome;酶联免疫吸附试验(ELISA)检测HUVEC与exosome共培养24 h后上清液中VEGF的变化水平;Western blot技术检测HUVEC与exosome共培养24 h后VEGF、VEGFR2及p-VEGFR2的蛋白表达情况;RT-PCR法检测HUVEC与exosome共培养24 h后VEGF的基因表达情况;观察HUVEC与exosome共培养24 h后的体外成管能力.结果 HUVEC与exosome共培养24 h后上清液中VEGF为(110.851±18.404)pg/mL,与对照组相比差异具有统计学意义(P<0.05);Western blot结果显示,HUVEC与exosome共培养24 h后VEGF和p-VEGFR2的蛋白表达水平均增加(P<0.05);RT-PCR结果显示,HUVEC与exosome共培养24 h后VEGF的基因表达水平增加(P<0.05);体外成管实验显示,exosome显著提高了HUVEC的管腔形成能力(P<0.05).结论 乳腺癌MDA-MB-231细胞源exosome促进了血管内皮细胞VEGF的表达及分泌,激活了血管内皮细胞VEGF/VEGFR2自分泌环并提高了血管内皮细胞的体外成管能力,对促肿瘤血管生成有一定的调控作用.%Objective To investigate the effects of exosomes derived from breast cancer cell line MDA-MB-231 on the expression of autocrine vascular endothelial growth factor (VEGF) and capillary-like tube formation in human umbilical vein endothelial cells ( HUVECs) , and to observe the regulatory effect of exosomes derived from cancer cells on angiogenesis in tumor microenvironment. Methods Exosomes were purified by serial ultracentrifugation and sugar density ultracentrifugation. The expression of autocrine VEGF in HUVECs with exosomes co-cultured 24 hours were detected by

  7. Capillary isoelectric focusing--useful tool for detection of the biofilm formation in Staphylococcus epidermidis.

    Science.gov (United States)

    Ruzicka, Filip; Horka, Marie; Hola, Veronika; Votava, Miroslav

    2007-03-01

    The biofilm formation is an important factor of S. epidermidis virulence. Biofilm-positive strains might be clinically more important than biofilm-negative ones. Unlike biofilm-negative staphylococci, biofilm-positive staphylococci are surrounded with an extracellular polysaccharide substance. The presence of this substance on the surface can affect physico-chemical properties of the bacterial cell, including surface charge. 73 S. epidermidis strains were examined for the presence of ica operon, for the ability to form biofilm by Christensen test tube method and for the production of slime by Congo red agar method. Isoelectric points (pI) of these strains were determined by means of Capillary Isoelectric Focusing. The biofilm negative strains focused near pI value 2.3, while the pI values of the biofilm positive strains were near 2.6. Isoelectric point is a useful criterion for the differentiation between biofilm-positive and biofilm-negative S. epidermidis strains. PMID:17157942

  8. Simulation of the migration in fracutred rock by a model based on capillary tubes

    International Nuclear Information System (INIS)

    In this paper the ability of a model based upon capillary tubes to reproduce the hydrodynamic dispersion in connection with flow of contaminated groundwater in fractured rock is investigated. It is assumed that the cross sectional areas are circular and that the flow is laminar. The molecular diffusion is neglected as well as the impact of variations in velocity over the cross-sectional area. It is assumed that the cross sectional areas in an ensemble of tubes belong to a gamma distribution. The velocity differences between tubes having different cross sectional area cause hydrodynamic dispersion. The model is applied to field tracer experiments at two sites. It is shown that the mean size of the cavities is smaller at a large depth and that the distribution is more narrow. The parameter in the gamma distribution has to be given different values to reproduce the breakthrough course at the different sites. It is also pointed out that there is no general relation between conductivity of a porous medium and its porosity without consideration of the pore size distribution. (au)

  9. A Capillary Tube-Refrigerant Charge Design Methodology for Household Refrigerators-Part II: Equivalent Diameter and Test Procedure

    OpenAIRE

    Boeng, Joel; Melo, Claudio

    2012-01-01

    In the first part of this work an experimental apparatus was designed and constructed to map the energy consumption of a household refrigerator subjected to several combinations of refrigerant charge and expansion restriction. In the second part, the expansion restriction imposed by the pair metering valve-capillary tube was converted into an equivalent tube diameter applying two different procedures: dry nitrogen flow and mathematical modeling. An empirical correlation to estimate the energy...

  10. From catastrophic acceleration to deceleration of liquid plugs in prewetted capillary tubes

    CERN Document Server

    Magniez, J C; Liu, C; Zoueshtiagh, F

    2016-01-01

    The dynamics of individual liquid plugs pushed at constant pressure head inside prewetted cylindrical capillary tubes is investigated experimentally and theoretically. It is shown that, depending on the thickness of the prewetting film and the magnitude of the pressure head, the plugs can either experience a continuous acceler ation leading to a catastrophic decrease of their size and eventually their rupture or conversely, a progressive deceleration associated with their growth. These behaviors are quantitatively reproduced with a simple nonlinear model [Baudoin et al., Proc. Nat. Ac. Sci. USA, 2013, 110, 859] adapted here for cylindrical channels. Furthermore, an analytical criterion for the transition between these two regimes is obtained and successfully compared with extensive experimental data. The implications of this work for pulmonary obstructive diseases are discussed.

  11. An Optical Fiber Viscometer Based on Long-Period Fiber Grating Technology and Capillary Tube Mechanism

    Directory of Open Access Journals (Sweden)

    Jian-Neng Wang

    2010-12-01

    Full Text Available This work addresses the development and assessment of a fiber optical viscometer using a simple and low-cost long-period fiber grating (LPFG level sensor and a capillary tube mechanism. Previous studies of optical viscosity sensors were conducted by using different optical sensing methods. The proposed optical viscometer consists of an LPFG sensor, a temperature-controlled chamber, and a cone-shaped reservoir where gravitational force could cause fluid to flow through the capillary tube. We focused on the use of LPFGs as level sensors and the wavelength shifts were not used to quantify the viscosity values of asphalt binders. When the LPFG sensor was immersed in the constant volume (100 mL AC-20 asphalt binder, a wavelength shift was observed and acquired using LabVIEW software and GPIB controller. The time spent between empty and 100 mL was calculated to determine the discharge time. We simultaneously measured the LPFG-induced discharge time and the transmission spectra both in hot air and AC-20 asphalt binder at five different temperatures, 60, 80, 100, 135, and 170 Celsius. An electromechanical rotational viscometer was also used to measure the viscosities, 0.15–213.80 Pa·s, of the same asphalt binder at the above five temperatures. A non-linear regression analysis was performed to convert LPFG-induced discharge time into viscosities. Comparative analysis shows that the LPFG-induced discharge time agreed well with the viscosities obtained from the rotational viscometer.

  12. Evaluation of Carbon Nanotubes Functionalized Polydimethylsiloxane Based Coatings for In-Tube Solid Phase Microextraction Coupled to Capillary Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    Neus Jornet-Martínez

    2015-08-01

    Full Text Available In the present work, the performance of carbon nanotubes (c-CNTs functionalized polydimethylsiloxane (PDMS based coatings as extractive phases for in-tube solid phase microextraction (IT-SPME coupled to Capillary LC (CapLC has been evaluated. Carboxylic-single walled carbon nanotubes (c-SWNTs and carboxylic-multi walled carbon nanotubes (c-MWNTs have been immobilized on the activated surface of PDMS capillary columns. The effect of different percentages of diphenyl groups in the PDMS extractive phase has also been evaluated. The extraction capability of the capillary columns has been tested for different organic pollutants, nitrogen heterocyclic compounds and polycyclic aromatic compounds (PAHs. The results indicated that the use of the c-CNTs-PDMS capillary columns improve pyriproxyfen and mainly PAH extraction. Triazines were better extracted by unmodified TRB-35 and modified c-CNTs-PDMSTRB-5. The results showed that the extraction capability of the c-CNT capillary columns depends not only on the polarity of the analytes (as it occurs with PDMS columns but also on the interactions that the analytes can establish with the immobilized c-CNTs on the PDMS columns. The extraction efficiency has been evaluated on the basis of the preconcentration rate that can be achieved, and, in this sense, the best c-CNTs-PDMS capillary column for each group of compounds can be proposed.

  13. 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

  14. An apparatus with a horizontal capillary tube intended for measurement of the surface tension of supercooled liquids

    Science.gov (United States)

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

    2015-05-01

    New experimental apparatus for measurement of the surface tension of liquids under the metastable supercooled state has been designed and assembled in the study. The measuring technique is similar to the method employed by P.T. Hacker [NACA TN 2510] in 1951. A short liquid thread of the liquid sample was sucked inside a horizontal capillary tube partly placed in a temperature-controlled glass chamber. One end of the capillary tube was connected to a setup with inert gas which allowed for precise tuning of the gas overpressure in order of hundreds of Pa. The open end of the capillary tube was precisely grinded and polished before the measurement in order to assure planarity and perpendicularity of the outer surface. The liquid meniscus at the open end was illuminated by a laser beam and observed by a digital camera. Application of an increasing overpressure of the inert gas at the inner meniscus of the liquid thread caused variation of the outer meniscus such that it gradually changed from concave to flat and subsequently convex shape. The surface tension at the temperature of the inner meniscus could be evaluated from the overpressure corresponding to exactly planar outer meniscus. Detailed description of the new setup together with results of the preliminary tests is provided in the study.

  15. 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...

  16. Underwater implosions of large format photo-multiplier tubes

    International Nuclear Information System (INIS)

    Large, deep, well shielded liquid detectors have become an important technology for the detection of neutrinos over a wide dynamic range from few MeV to TeV. The critical component of this technology is the large format semi-hemispherical photo-multiplier tube with diameters in the range of 25–50 cm. The survival of an assembled array of these photo-multiplier tubes under high hydrostatic pressure is the subject of this study. These are the results from an R and D program which is intended to understand the modes of failure when a photo-multiplier tube implodes under hydrostatic pressure. Our tests include detailed measurements of the shock wave which results from the implosion of a photo-multiplier tube and a comparison of the test data to modern hydrodynamic simulation codes. Using these results we can extrapolate to other tube geometries and make recommendation on deployment of the photo-multiplier tubes in deep water detectors with a focus on risk mitigation from a tube implosion shock wave causing a chain reaction loss of multiple tubes.

  17. Performance prediction for non-adiabatic capillary tube suction line heat exchanger: an artificial neural network approach

    International Nuclear Information System (INIS)

    This study presents an application of the artificial neural network (ANN) model using the back propagation (BP) learning algorithm to predict the performance (suction line outlet temperature and mass flow rate) of a non-adiabatic capillary tube suction line heat exchanger, basically used as a throttling device in small household refrigeration systems. Comparative studies were made by using an ANN model, experimental results and correlations to predict the performance. These studies showed that the proposed approach could successfully be used for performance prediction for the exchanger

  18. Study of thermal performance of capillary micro tubes integrated into the building sandwich element made of high performance concrete

    DEFF Research Database (Denmark)

    Mikeska, Tomas; Svendsen, Svend

    2013-01-01

    The thermal performance of radiant heating and cooling systems (RHCS) composed of capillary micro tubes (CMT) integrated into the inner plate of sandwich elements made of high performance concrete (HPC) was investigated in the article. Temperature distribution in HPC elements around integrated CMT...... and cooling purposes of future low energy buildings. The investigations were conceived as a low temperature concept, where the difference between the temperature of circulating fluid and air in the room was kept in range of 1–4 °C....

  19. An experimental and numerical investigation of thermocapillary driven phenomena for evaporating menisci in capillary tubes related to microelectronics cooling

    Science.gov (United States)

    Buffone, Cosimo

    The present work is an experimental and numerical investigation of the hydrodynamics of a meniscus formed by a liquid in capillary tubes undergoing phase change. The non uniform evaporation process along the liquid-vapour interface leads to self-induced temperature field that in turn generates surface tension gradients along the meniscus. The interfacial stress so created drives a vigorous liquid convection that is measured by using a micro-Particle Image Velocimetry (micro-PIV) technique. Temperature measurements using advanced Infra Red (IR) and Thermochromic Liquid Crystal (TLC) techniques allowed us to measure the interfacial temperature profile (IR) and external capillary tube temperature (TLC). Measuring velocity and temperature at such scales is not trivial because conventional techniques such as thermocouples cannot be used. Therefore, efforts have been made to compare the measurements gathered from different techniques: TLC and IR external wall measurements for the temperature field and micro-PIV measurements and numerical analysis for the velocity field. The TLC temperature measurements show the important sink effect close to the meniscus near contact line region. By measuring the evaporation mass flux and performing a heat transfer analysis based on the measured wall temperature of the system, a very good agreement was found, giving confidence to the temperature measurements performed with TLC. IR measurement of the external capillary tube wall was also taken and compares well with the TLC ones. Tube sizes ranging from 200 to 1,630 mm and four volatile liquids were investigated. Different experimental studies were conducted with both vertically and horizontally oriented capillaries, with and without external heating. It is observed that symmetrical flow patterns found in horizontal diametrical sections of the tube are dramatically distorted in vertical diametrical sections, presumably due to gravity. The IR measurements of the liquid-vapour interface

  20. Capillary wave formation on excited solder jet and fabrication of lead-free solder ball

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shu-guang; HE Li-jun; ZHU Xue-xin; ZHANG Shao-ming; SHI Li-kai; XU Jun

    2005-01-01

    A survey of solder ball production processes especially focusing on disturbed molten metal jet breakup process was made. Then the formation of capillary wave on tin melt jet in the way of rapid solidification was studied. A semi-empirical formula, which can be written as λ = Cvib (σ/ρ)1/3f-2/3 to predict the relationship between wavelength of capillary wave and frequency of imposed vibration was obtained. Sn-4.0Ag-0.5Cu lead free solder ball was successfully produced with tight distribution and good sphericity. The excited jet breakup process is promising for cost effectively producing solder ball.

  1. Germ Tube Formation Changes Surface Hydrophobicity of Candida Cells

    Directory of Open Access Journals (Sweden)

    A. F. Fonseca

    1999-01-01

    Full Text Available Hydrophobic interaction is generally considered to play an important role in the adherence of microorganisms to eukaryotic cells and also to certain inert surfaces. Using a microbe adhesion assay to hydrocarbons (n-hexadecane, 68 strains of Candida albicans and 30 non-albicans strains were studied. Influence of source of isolate, age of the culture, and percentage of germ tube formation on adhesion were studied. C: albicans blastoconidia were found to be hydrophilic; conversely, blastoconidia of non-albicans strains were slightly more hydrophobic. Germ tube formation was associated with a significant rise in cell surface hydrophobicity. Infect. Dis. Obstet. Gynecol. 7:222–226, 1999.

  2. 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...

  3. Extract of Indian green mussel, Perna viridis (L.) shows inhibition of blood capillary formation in vitro

    Digital Repository Service at National Institute of Oceanography (India)

    Mirshahi, M.; Mirshahi, P.; Negro, S.; Soria, J.; Sreekumar, P.K.; Kotnala, S.; Therwath, A.; Chatterji, A.

    Pertanika J. Trop. Agric. Sci. 32(1): 35 - 42 (2009) ISSN: 1511-3701 ©Universiti Putra Malaysia Press Received: 20 May 2008 Accepted: 8 October 2008 * Corresponding Author Extract of Indian Green Mussel, Perna viridis (L.) Shows Inhibition of Blood... the researchers to envisage further investigation on the possible role of the active substances contained in these extracts on the formation of blood capillary and angiogenesis at large. PDF compression, OCR, web optimization using a watermarked evaluation...

  4. Highly sensitive biosensing based on interference from light scattering in capillary tubes

    Science.gov (United States)

    Sørensen, Henrik S.; Larsen, Niels B.; Latham, Joey C.; Bornhop, Darryl J.; Andersen, Peter E.

    2006-10-01

    Human IgG interactions with surface bound protein A are monitored label-free using microinterferometric backscatter detection. An electromagnetic wave-based model is developed and used to quantitatively describe the change in interference pattern as a consequence of the molecular interaction with the affinity layer on the fused silica capillary. Within the framework of the model it is of paramount importance to establish a valid stop criterion for the infinite summations involved in the fringe pattern computations. The high sensitivity towards surface changes, ease of changing the surface chemistry to other specific interacting layers, and simplicity of the optical sensor make this technique a powerful tool in biosensing.

  5. Experimental sizing and assessment of two-phase pressure drop correlations for a capillary tube with transcritical and subcritical carbon dioxide flow

    International Nuclear Information System (INIS)

    In the last years, CO2 was proposed as an alternative refrigerant for different refrigeration applications (automotive air conditioning, heat pumps, refrigerant plants, etc.) In the case of low power refrigeration applications, as a household refrigerator, the use of too expensive components is not economically sustainable; therefore, even if the use of CO2 as the refrigerant is desired, it is preferable to use conventional components as much as possible. For these reasons, the capillary tube is frequently proposed as expansion system. Then, it is necessary to characterize the capillary in terms of knowledge of the evolving mass flow rate and the associate pressure drop under all possible operative conditions. For this aim, an experimental campaign has been carried out on the ENEA test loop 'CADORE' to measure the performance of three capillary tubes having same inner diameter (0.55 mm) but different lengths (4, 6 and 8 meters). The test range of inlet pressure is between about 60 and 110 bar, whereas external temperatures are between about 20 to 42 °C. The two-phase pressure drop through the capillary tube is detected and experimental values are compared with the predictions obtained with the more widely used correlations available in the literature. Correlations have been tested over a wide range of variation of inlet flow conditions, as a function of different inlet parameters.

  6. Experimental sizing and assessment of two-phase pressure drop correlations for a capillary tube with transcritical and subcritical carbon dioxide flow

    Science.gov (United States)

    Trinchieri, R.; Boccardi, G.; Calabrese, N.; Celata, G. P.; Zummo, G.

    2014-04-01

    In the last years, CO2 was proposed as an alternative refrigerant for different refrigeration applications (automotive air conditioning, heat pumps, refrigerant plants, etc.) In the case of low power refrigeration applications, as a household refrigerator, the use of too expensive components is not economically sustainable; therefore, even if the use of CO2 as the refrigerant is desired, it is preferable to use conventional components as much as possible. For these reasons, the capillary tube is frequently proposed as expansion system. Then, it is necessary to characterize the capillary in terms of knowledge of the evolving mass flow rate and the associate pressure drop under all possible operative conditions. For this aim, an experimental campaign has been carried out on the ENEA test loop "CADORE" to measure the performance of three capillary tubes having same inner diameter (0.55 mm) but different lengths (4, 6 and 8 meters). The test range of inlet pressure is between about 60 and 110 bar, whereas external temperatures are between about 20 to 42 °C. The two-phase pressure drop through the capillary tube is detected and experimental values are compared with the predictions obtained with the more widely used correlations available in the literature. Correlations have been tested over a wide range of variation of inlet flow conditions, as a function of different inlet parameters.

  7. Determination of urinary 8-hydroxy-2′-deoxyguanosine by capillary electrophoresis with molecularly imprinted monolith in-tube solid phase microextraction

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Urinary 8-hydroxy-2'-deoxyguanosine(8-OHdG) is an excellent marker of oxidative DNA damage.In this study,employing guanosine as dummy template a novel molecularly imprinted(MIP) monolithic capillary column had been synthesized,and that was used as medium of in-tube solid phase microextraction(SPME).Coupled with capillary electrophoresis-electrochemical detection(CE-ECD),the system of extraction and detection of 8-OHdG in urinary sample had been developed.Because of its greater phase ratio combined with c...

  8. Simple and rapid capillary electrophoresis analysis of formate in blood of methanol intoxicated persons

    Czech Academy of Sciences Publication Activity Database

    Pantůčková, Pavla; Kubáň, Pavel; Boček, Petr

    Česká farmaceutická společnost České lékařské společnosti J. E. Purkyně, 2013. s. 126-126. [Syntéza a analýza léčiv /42./. 02.09.2013-05.09.2013, Velké Karlovice] R&D Projects: GA ČR(CZ) GP13-05762S Institutional support: RVO:68081715 Keywords : blood samples * capillary electrophoresis * formate Subject RIV: CB - Analytical Chemistry, Separation

  9. Numerical Modelling of Performance of R22 and R290 in Adiabatic Capillary Tubes Considering Metastable Two-Phase Region--Theoretical Model Description and Validation

    Institute of Scientific and Technical Information of China (English)

    ZHOU Guobing; ZHANG Yufeng; HAO Hong

    2005-01-01

    A homogeneous theoretical model is developed to predict the performance of R22 and R290 in adiabatic capillary tubes. The model is based on conservation equations of mass, momentum and energy. Metastable both liquid and two-phase flow regions are considered in the model. In metastable two-phase region, superheated liquid is introduced into the metastable mixture viscosity and two methods are presented to evaluate it. The model is validated by comparing the predicted pressure and temperature profile and mass flow rate with several investigators′ experimental data of R22 and one of its alternatives R290 reported in literature. All of the predicted mass flow rates are within ±8% of measured values. Comparisons are also made between the present model and other investigators′ models or sizing correlation. The model can be used for design or simulation calculation of adiabatic capillary tubes.

  10. Low-temperature, low-cost growth of robust ATR GeO2 hollow fibers based on copper capillary tubes for transmission of CO2 laser light

    Science.gov (United States)

    Jing, Chengbin; Bai, Wei; Hu, Zhigao; Yang, Pingxiong; Liu, Aiyun; Lin, Fangtin; Shi, Yiwei; Chu, Junhao

    2014-02-01

    Attenuated total reflectance (ATR) infrared hollow waveguide attracts particular interest since it has both advantages of a hollow fiber and a light guiding mechanism similar to that of solid-core fibers. Presently, ATR hollow waveguides are mainly structured with single-crystal sapphire or glassy materials. These waveguides are somewhat brittle. More robust ATR hollow fibers are required in many military and domestic applications. In this work, ATR GeO2 hollow waveguides were prepared based on a copper capillary tube for transmitting CO2 laser light. The inner wall of the copper structural tube was polished using a high-pressure pulsed nanofluid technique. A hexagonal crystalline GeO2 reflective layer with sufficient thickness (>4 μm) was grown on the inner tube wall via a simple liquid phase deposition process at room temperature. The GeO2 coated copper hollow fiber exhibits a low-loss band within 10-11.5 μm. It can still be bent since the hollow-core size (1.4 mm) and the wall thickness (50 μm) are not too large. The transmissions of CO2 laser light are 91% and 43% under a straight condition and a 90° bend with a 30-cm radius condition, respectively. The waveguide displays high heat-resisting properties due to high thermal conductivity of the copper substrate tube and a high melting point (1115°C) of the GeO2 reflective layer. This work opens a door for low-temperature, low-cost growth of long ATR GeO2 infrared hollow fibers based on various substrate tubes, even including plastic capillary tubes.

  11. Formation of hydride blisters in zirconium alloy pressure tubes

    International Nuclear Information System (INIS)

    The fracture of the Zircaloy-2 pressure tube in the Pickering Unit 2 power reactor was associated with the growth of hydride blisters at points of contact between the pressure tube and the cooler calandria tube surrounding it. Similar blisters have been observed in a Zr-2.5 wt% Nb pressure tube in WR-1, an organic-cooled research reactor. These hydride blisters were formed and grew as a result of the thermal diffusion of hydrogen in the zirconium, a mechanism whereby hydrogen diffuses down a temperature gradient. If the terminal solid solubility of hydrogen is exceeded in the cooler regions, hydride will precipitate. In this paper, the time required to grow these hydride blisters will be estimated from the blister size and the hydrogen distribution in its neighborhood, by using simple equations derived from thermal diffusion theory

  12. A computational study of two-phase viscoelastic systems in a capillary tube with a sudden contraction/expansion

    Science.gov (United States)

    Muradoglu, Metin; Izbassarov, Daulet

    2015-11-01

    Two-phase viscoelastic systems are computationally studied in a pressure-driven tube with a sudden contraction and expansion using a finite-difference/front-tracking method. The effects of viscoelasticity in drop and bulk fluids are investigated including high Weissenberg and Reynolds number cases up to Wi = 100 and Re = 100 . The FENE-CR model is used to account for the fluid viscoelasticity. Extensive computations are performed to examine drop dynamics for a wide range of parameters. It is found that viscoelasticity interacts with drop interface in a non-monotonic and complicated way, and the two-phase viscoelastic systems exhibit very rich dynamics especially in the expansion region. At high Re , the drop undergoes large deformation in the contraction region followed by shape oscillations in the downstream of the expansion. For a highly viscous drop, a re-entrant cavity develops in the contraction region at the trailing edge which, in certain cases, grows and eventually causes encapsulation of ambient fluid. The re-entrant cavity formation is initiated at the entrance of the contraction and is highly influenced by the viscoelasticity. The effects of viscoelasticity are reversed in the constricted channel: Viscoelasticity in drop/continuous phase hinders/enhances format The authors are grateful to the Scientific and Technical Research Council of Turkey (TUBITAK) for the support of this research through Grant 112M181 and Turkish Academy of Sciences (TUBA).

  13. Erythorbic acid promoted formation of CdS QDs in a tube-in-tube micro-channel reactor

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Yan; Tan, Jiawei; Wang, Jiexin; Chen, Jianfeng [State Key Laboratory of Organic–Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Research Center of the Ministry of Education for High Gravity Engineering and Technology, Beijing University of Chemical Technology, Beijing 100029 (China); Sun, Baochang, E-mail: sunbc@mail.buct.edu.cn [State Key Laboratory of Organic–Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Research Center of the Ministry of Education for High Gravity Engineering and Technology, Beijing University of Chemical Technology, Beijing 100029 (China); Shao, Lei, E-mail: shaol@mail.buct.edu.cn [State Key Laboratory of Organic–Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Research Center of the Ministry of Education for High Gravity Engineering and Technology, Beijing University of Chemical Technology, Beijing 100029 (China)

    2014-12-15

    Erythorbic acid assistant synthesis of CdS quantum dots (QDs) was conducted by homogeneous mixing of two continuous liquids in a high-throughput microporous tube-in-tube micro-channel reactor (MTMCR) at room temperature. The effects of the micropore size of the MTMCR, liquid flow rate, mixing time and reactant concentration on the size and size distribution of CdS QDs were investigated. It was found that the size and size distribution of CdS QDs could be tuned in the MTMCR. A combination of erythorbic acid promoted formation technique with the MTMCR may be a promising pathway for controllable mass production of QDs.

  14. Reducing Mechanical Formation Damage by Minimizing Interfacial Tension and Capillary Pressure in Tight Gas

    International Nuclear Information System (INIS)

    Tight gas reservoirs incur problems and significant damage caused by low permeability during drilling, completion, stimulation and production. They require advanced improvement techniques to achieve flow gas at optimum rates. Water blocking damage (phase Trapping/retention of fluids) is a form of mechanical formation damage mechanism, which is caused by filtrate invasion in drilling operations mostly in fracturing. Water blocking has a noticeable impact on formation damage in gas reservoirs which tends to decrease relative permeability near the wellbore. Proper evaluation of damage and the factors which influence its severity is essential to optimize well productivity. Reliable data regarding interfacial tension between gas and water is required in order to minimize mechanical formation damage potential and to optimize gas production. This study was based on the laboratory experiments of interfacial tension by rising drop method between gas-brine, gas-condensate and gas-brine. The results showed gas condensate has low interfacial tension value 6 – 11 dynes/cm when compared to gas-brine and gas- diesel which were 44 – 58 dynes/cm and 14 – 19 dynes/cm respectively. In this way, the capillary pressure of brine-gas system was estimated as 0.488 psi, therefore diesel-gas system was noticed about 0.164 psi and 0.098 psi for condensate-gas system. A forecast model was used by using IFT values to predict the phase trapping which shows less severe phase trapping damage in case of condensate than diesel and brine. A reservoir simulation study was also carried out in order to better understand the effect of hysteresis on well productivity and flow efficiency affected due to water blocking damage in tight gas reservoirs

  15. CD13/APN is activated by angiogenic signals and is essential for capillary tube formation

    OpenAIRE

    Bhagwat, Shripad V.; Lahdenranta, Johanna; Giordano, Ricardo J.; Arap, Wadih; Pasqualini, Renata; Shapiro, Linda H.

    2001-01-01

    In the hematopoietic compartment, the CD13/APN metalloprotease is one of the earliest markers of cells committed to the myeloid lineage where it is expressed exclusively on the surface of myeloid progenitors and their differentiated progeny. CD13/APN is also found in nonhematopoietic tissues, and its novel expression on the endothelial cells of angiogenic, but not normal, vasculature was recently described. Treatment of animals with CD13/APN inhibitors significantly impaired retinal neovascul...

  16. Preparation and transmission characteristics of a mid-infrared attenuated total reflection hollow waveguide based on a stainless steel capillary tube.

    Science.gov (United States)

    Wang, Xu; Guo, Hong; Wang, Lin; Yue, Fangyu; Jing, Chengbin; Chu, Junhao

    2016-08-10

    Stainless steel (SUS) capillary tubes were examined as a category of structural tube for establishing a metallic attenuated total reflection (ATR) GeO2 hollow waveguide. GeO2 films were grown on the inner wall of SUS tubes by different liquid phase deposition (LPD) cycles. Fourier transform infrared (FTIR) spectra, scanning electronic microscope (SEM) image, and transmission loss for a CO2 laser were measured to investigate the effects of the LPD cycles on the transmission behavior of the hollow waveguide samples. The film thickness and surface roughness increase with every LPD cycle. The two LPD cycle sample has a film thickness equivalent to the CO2 laser wavelength, while the surface roughness is acceptable. This sample has the lowest transmission loss (0.27  dB/m) among these samples. The bending loss, output beam profile, and full divergence angle (FDA) were further studied. Higher-order modes are excited by bending the sample, inducing additional loss, decentralized beam profile, and larger FDA. PMID:27534486

  17. Visualizing biofilm formation in endotracheal tubes using endoscopic three-dimensional optical coherence tomography

    Science.gov (United States)

    Heidari, Andrew E.; Moghaddam, Samer; Troung, Kimberly K.; Chou, Lidek; Genberg, Carl; Brenner, Matthew; Chen, Zhongping

    2015-12-01

    Biofilm formation has been linked to ventilator-associated pneumonia, which is a prevalent infection in hospital intensive care units. Currently, there is no rapid diagnostic tool to assess the degree of biofilm formation or cellular biofilm composition. Optical coherence tomography (OCT) is a minimally invasive, nonionizing imaging modality that can be used to provide high-resolution cross-sectional images. Biofilm deposited in critical care patients' endotracheal tubes was analyzed in vitro. This study demonstrates that OCT could potentially be used as a diagnostic tool to analyze and assess the degree of biofilm formation and extent of airway obstruction caused by biofilm in endotracheal tubes.

  18. Microfluidic method for rapid turbidimetric detection of the DNA of Mycobacterium tuberculosis using loop-mediated isothermal amplification in capillary tubes

    International Nuclear Information System (INIS)

    We describe a microfluidic method for rapid isothermal turbidimetric detection of the DNA of Mycobacterium tuberculosis. Loop-mediated isothermal amplification is accomplished in capillary tubes for amplifying DNA in less than 15 min, and sensitivity and specificity were compared to conventional loop-mediated isothermal amplification (LAMP). The method can detect as little as 1 pg mL−1 DNA in a sample. Results obtained with clinical specimens indicated 90 % sensitivity and 95 % specificity for microfluidic LAMP in comparison to culture methods. No interference occurred due to the presence of nonspecific DNAs. The findings demonstrate the power of the new microfluidic LAMP test for rapid molecular detection of microorganisms even when using bare eyes. (author)

  19. Biofilm formation on tympanostomy tubes depends on methicillin-resistant Staphylococcus aureus genetic lineage.

    Science.gov (United States)

    Jotić, Ana; Božić, Dragana D; Milovanović, Jovica; Pavlović, Bojan; Ješić, Snežana; Pelemiš, Mijomir; Novaković, Marko; Ćirković, Ivana

    2016-03-01

    Bacterial biofilm formation has been implicated in the high incidence of persistent otorrhoea after tympanostomy tube insertion. The aim of the study was to investigate whether biofilm formation on tympanostomy tubes depends on the genetic profile of methicillin-resistant Staphylococcus aureus (MRSA) strains. Capacity of biofilm formation on fluoroplastic tympanostomy tubes (TTs) was tested on 30 MRSA strains. Identification and methicillin resistance were confirmed by PCR for nuc and mecA genes. Strains were genotypically characterised (SCCmec, agr and spa typing). Biofilm formation was tested in microtiter plate and on TTs. Tested MRSA strains were classified into SCCmec type I (36.7 %), III (23.3 %), IV (26.7 %) and V (13.3 %), agr type I (50 %), II (36.7 %) and III (13.3 %), and 5 clonal complexes (CCs). All tested MRSA strains showed ability to form biofilm on microtiter plate. Capacity of biofilm formation on TTs was as following: 13.3 % of strains belonged to the category of no biofilm producers, 50 % to the category of weak biofilm producers and 36.7 % to moderate biofilm producers. There was a statistically significant difference between CC, SCCmec and agr types and the category of biofilm production on TTs tubes (p tube otorrhea. PMID:25796207

  20. Albendazole inhibits endothelial cell migration, tube formation, vasopermeability, VEGF receptor-2 expression and suppresses retinal neovascularization in ROP model of angiogenesis

    International Nuclear Information System (INIS)

    The angiogenic process begins with the cell proliferation and migration into the primary vascular network, and leads to vascularization of previously avascular tissues and organs as well to growth and remodeling of the initially homogeneous capillary plexus to form a new microcirculation. Additionally, an increase in microvascular permeability is a crucial step in angiogenesis. Vascular endothelial growth factor (VEGF) plays a central role in angiogenesis. We have previously reported that albendazole suppresses VEGF levels and inhibits malignant ascites formation, suggesting a possible effect on angiogenesis. This study was therefore designed to investigate the antiangiogenic effect of albendazole in non-cancerous models of angiogenesis. In vitro, treatment of human umbilical vein endothelial cells (HUVECs) with albendazole led to inhibition of tube formation, migration, permeability and down-regulation of the VEGF type 2 receptor (VEGFR-2). In vivo albendazole profoundly inhibited hyperoxia-induced retinal angiogenesis in mice. These results provide new insights into the antiangiogenic effects of albendazole.

  1. From hydrodynamic plumes to chemical gardens: the concentration-dependent onset of tube formation.

    Science.gov (United States)

    Batista, Bruno C; Cruz, Patrick; Steinbock, Oliver

    2014-08-01

    Many inorganic precipitation reactions self-organize macroscopic tubes known as chemical gardens. We study the nonequilibrium formation of these structures by injecting aqueous sodium sulfide solution into a reservoir of iron(II) chloride solution. Our experiments reveal a distinct, concentration-dependent transition from convective plumes of reaction-induced, colloidal particles to mechanically connected, hollow tubes. The transition concentration (0.1 mol/L) is widely independent of the injection rate and causes a discontinuous change from the radius of the plume stalk to the radius of the tube. In addition, tubes have lower growth speeds than plumes. At the transition concentration, one observes the initial formation of a plume followed by the growth of a mechanically weak tube around a jet of upward-moving precipitation particles. We find that the plumes' morphology and geometric scaling are similar to that of laminar starting plumes in nonreactive systems. The characterization of dried tubes by X-ray diffraction indicates the presence of greigite and lepidocrocite. PMID:25014675

  2. The formation of vault-tubes: a dynamic interaction between vaults and vault PARP.

    Science.gov (United States)

    van Zon, Arend; Mossink, Marieke H; Schoester, Martijn; Houtsmuller, Adriaan B; Scheffer, George L; Scheper, Rik J; Sonneveld, Pieter; Wiemer, Erik A C

    2003-11-01

    Vaults are barrel-shaped cytoplasmic ribonucleoprotein particles that are composed of a major vault protein (MVP), two minor vault proteins [telomerase-associated protein 1 (TEP1), vault poly(ADP-ribose) polymerase (VPARP)] and small untranslated RNA molecules. Not all expressed TEP1 and VPARP in cells is bound to vaults. TEP1 is known to associate with the telomerase complex, whereas VPARP is also present in the nuclear matrix and in cytoplasmic clusters (VPARP-rods). We examined the subcellular localization and the dynamics of the vault complex in a non-small cell lung cancer cell line expressing MVP tagged with green fluorescent protein. Using quantitative fluorescence recovery after photobleaching (FRAP) it was shown that vaults move temperature independently by diffusion. However, incubation at room temperature (21 degrees C) resulted in the formation of distinct tube-like structures in the cytoplasm. Raising the temperature could reverse this process. When the vault-tubes were formed, there were fewer or no VPARP-rods present in the cytoplasm, suggesting an incorporation of the VPARP into the vault-tubes. MVP molecules have to interact with each other via their coiled-coil domain in order to form vault-tubes. Furthermore, the stability of microtubules influenced the efficiency of vault-tube formation at 21 degrees C. The dynamics and structure of the tubes were examined using confocal microscopy. Our data indicate a direct and dynamic relationship between vaults and VPARP, providing further clues to unravel the function of vaults. PMID:13130096

  3. Results of the combination of open transthoracic esophagectomy with laparoscopic gastric tube formation for esophageal cancer

    NARCIS (Netherlands)

    H.A. Cense; O.R.C. Busch; W.A. Bemelman; H. Obertop; J.J.B. van Lanschot

    2006-01-01

    Background: Postoperative complications after open transthoracic esophagectomy could possibly be reduced if the abdominal phase is performed laparoscopically. The aim of this study was to investigate the feasibility of laparoscopic mobilization of the stomach and gastric tube formation in patients u

  4. Formation of corrosion products protecting surfaces of the boiler proper tubes from the combustion chamber

    Directory of Open Access Journals (Sweden)

    M. Pietrzyk

    2007-04-01

    Full Text Available Purpose: The aim of this paper is to determine how the oxidation product layer of the steel applied for the radiant tubes should increase if we are going to obtain the lowest possible corrosion losses.Design/methodology/approach: Boiler tubes, made of 13CrMo4-5 steel were subjected to tests. In the boiler BP-1150, the tubes ø 30 x 5 mm are joined by fins and form a membrane shield. According to the maps of tube wall thickness, in the zone of the highest heat load, sectors of the shield were sampled in the places where the tube wall thickness was equal or greater than 4.3 mm, i.e. the minimum calculation thickness, according to the specifications given by the boiler manufacturer. It means that the corrosive loss could be determined as small, in spite of a long operation time (more than 60,000 hours.Findings: The authors have determined structure and chemical and phase compositions of products and deposits forming in the radiant tubes in the regions of low corrosive losses after long-lasting operation (up to 60,000 hours. Then, they discussed a mechanism of formation of a compact layer protecting a steel surface against excessive oxidation under combustion gases.Practical implications: The layer on the tubes with small losses of wall thickness are characterized by the following properties: good compactness, very good adhesion to the metallic base, low amount of sulfur, especially in magnetite, no aggressive components at the phase boundary product – steel, small development of the phase boundary product-steel. Owing to those properties, even presence of sulfur in the products do not reduce their passivation qualities.Originality/value: Determination of the oxidation product layer of the steel applied for the radiant tubes.

  5. Tube formation in the first trimester placental trophoblast cells: Differential effects of angiogenic growth factors and fatty acids.

    Science.gov (United States)

    Pandya, Abhilash D; Das, Mrinal K; Sarkar, Arnab; Vilasagaram, Srinivas; Basak, Sanjay; Duttaroy, Asim K

    2016-06-01

    The study aims to investigate whether cytosolic fatty acid-binding protein-4 (FABP4) is involved in angiogenic growth factors- and fatty acid-induced tube formation in first trimester placental trophoblast cells, HTR8/SVneo. We determined the tube formation both at basal as well as stimulated levels in the absence and presence of inhibitors of FABP4 and VEGF signaling pathways. Basal level of tube formation was maximally reduced in the presence of 50 µM of FABP4 inhibitor compared with those by VEGF signaling pathway inhibitors (rapamycin, L-NAME, and p38 MAP kinase inhibitor). Whereas docosahexaenoic acid, 22:6n-3 (DHA)-, and VEGF-induced tube formation was maximally inhibited by p38 MAP kinase inhibitor (63.7 and 34.5%, respectively), however, leptin-induced tube formation was inhibited maximally by FABP4 inhibitor (50.7%). ANGPTL4 and oleic acid (OA)-induced tube formation was not blocked by any of these inhibitors. The FABP4 inhibitor inhibited cell growth stimulated by DHA, leptin, VEGF, and OA (P DHA, and leptin, whereas it has little or no effect in ANGPTL4- and OA-induced tube formation in these cells. Thus, FABP4 may play a differential role in fatty acids and angiogenic growth factors-mediated tube formation in the first trimester trophoblast cells in vitro. PMID:26992362

  6. Formation of neuro-glio-capillary relation in neurohypophysis on different stages of postnatal period of ontogenesis

    Directory of Open Access Journals (Sweden)

    Zhurahivska O.Ja.

    2009-01-01

    Full Text Available Although the row of works is devoted to ontogenesis of hypophysis, a question on what stage of ontogenesis hypothalamic-neyrohypophysal system starts its functions is rather controversial and needs subsequent study. Therefore, our purpose was to research the patterns of becoming neyro-glio-capillary correlations of the posterior lobe of hypophysis on the stages of postnatal ontogenesis. The material for research were the pieces of neurohypophysis of 40 white purebred rats of males in age: new-born, 7, 45 and 90 days after birth. At the fence of material for electron microscopic research the generally accepted rules of speed of carving are observed and not traumatic. The research of ultrastructure of neurohypophysis of white rats showed that on the first week of their life the amount of axon-vessel synapses and neurosecretory granules had increased, among which a zonality of situation of different types of them is observed, that testifies to completion of neurosecretory structures formation. Submicroscopic structure of sinus capillaries in this term specifies on their high functional activity, in particular, about an enhanceable transendothelial transport. Thus, our research allows to draw a conclusion, that already dur-ing the first week of life in the structure of neurohypophysis of rats substantial high-quality and quantitative changes take place, which testify to completion of becoming of its neurosecretory structures and on later stages of postnatal development they are only perfected.

  7. Cytogenetic analysis of mechanism of formation of radiation-induced chromosome exchanges. [Crepis capillaris, x radiation

    Energy Technology Data Exchange (ETDEWEB)

    Azatyan, R.A.; Akif' ev, A.P.; Shavel' zon, R.A.; Voskanyan, A.Z.; Zakaryan, M.S.

    1977-01-01

    An unusual spectrum of aberrations, characterized by a sharp exchange deficiency, was demonstrated in germinating seeds of Crepis capillaris L. synchronized with 2'-deoxy-5-fluorouridine at the start of the S phase following exposure to 100 R x-rays. The modification of the cytogenetic effect of x-radiation of dry crepis seeds (10 and 15 kR) by 5-aminouracil consisted of a higher yield of aberrations without decrease in share of exchanges of the chromosome type. The obtained data are consistent with the hypothesis that exchange aberrations occur due to interaction between spontaneous single-stranded DNA defects limited to identical or similar repeated nucleotide sequences The exchange interactions are blocked when the cells move into the stage of DNA synthesis.

  8. Treatment with some anti-inflammatory drugs reduces germ tube formation in Candida albicans strains

    OpenAIRE

    Elena Rusu; Manuela Radu-Popescu; Diana Pelinescu; Tatiana Vassu

    2015-01-01

    Candida albicans is an opportunistic dimorphic fungus that inhabits various host mucosal sites. It can cause both superficial and serious systemic disease. Conversion from the yeast to the hyphal form has been associated with increased virulence and mucosal invasiveness. The aim of this study was to investigate the effect of sodium diclofenac and aspirin on germs tube formation of different Candida albicans strains. Prostaglandins may play an important role in fungal colonization. Nonsteroida...

  9. Statistical analysis of the factors induced defect formation during welding tubes for fuel channels

    International Nuclear Information System (INIS)

    Using as an example the welding of the mounting joints of 160x10mm 08Kh18N10T steel tubes for fuel channels of the RBM-K-1000 reactor, considered is the effect of the three main factors, causing formation of the defects in welded joints: constructional, technological and organizational. Emperic equations of the defectiveness and the above mentioned factors for the statistical analysis of the welding quality during the mounting of nuclear power stations are suggested

  10. The formation of an ion beam in a vacuum neutron tube

    Science.gov (United States)

    Agafonov, A. V.; Tarakanov, V. P.

    2014-09-01

    The formation of a deuteron beam in a diode with a plasma emitter that is integrated into the structure of a vacuum neutron tube is considered. Computations are carried out for plasma with given time dependences of parameters (density, relative concentration, and expansion velocity) at the inlet to an accelerating gap. It is shown that it is possible to increase the ion-beam current possible by sectioning the diode at the given external parameters.

  11. Treatment with some anti-inflammatory drugs reduces germ tube formation in Candida albicans strains

    Directory of Open Access Journals (Sweden)

    Elena Rusu

    2014-12-01

    Full Text Available Candida albicans is an opportunistic dimorphic fungus that inhabits various host mucosal sites. It can cause both superficial and serious systemic disease. Conversion from the yeast to the hyphal form has been associated with increased virulence and mucosal invasiveness. The aim of this study was to investigate the effect of sodium diclofenac and aspirin on germs tube formation of different Candida albicans strains. Prostaglandins may play an important role in fungal colonization. Nonsteroidal anti-inflammatory drugs are inhibitors of the cyclooxygenase isoenzymes. These drugs specifically block the biosynthesis of mammalian prostaglandins by inhibiting one or both of cyclooxygenase isoenzymes. In tests for germ tube formation sodium diclofenac reduced the filamentation to the 12.5%- 5.1%. In the presence of aspirin the filamentation was reduced up to 85-45% depending on the tested strain. Our results suggest that cyclooxygenase-depending synthesis of fungal prostaglandins is important for morphogenesis and fungal virulence. Inhibitors of cyclooxygenase isoensymes (aspirin and diclofenac are effective in decreasing germ tube formation of Candida albicans.

  12. QHREDGS enhances tube formation, metabolism and survival of endothelial cells in collagen-chitosan hydrogels.

    Directory of Open Access Journals (Sweden)

    Jason W Miklas

    Full Text Available Cell survival in complex, vascularized tissues, has been implicated as a major bottleneck in advancement of therapies based on cardiac tissue engineering. This limitation motivates the search for small, inexpensive molecules that would simultaneously be cardio-protective and vasculogenic. Here, we present peptide sequence QHREDGS, based upon the fibrinogen-like domain of angiopoietin-1, as a prime candidate molecule. We demonstrated previously that QHREDGS improved cardiomyocyte metabolism and mitigated serum starved apoptosis. In this paper we further demonstrate the potency of QHREDGS in its ability to enhance endothelial cell survival, metabolism and tube formation. When endothelial cells were exposed to the soluble form of QHREDGS, improvements in endothelial cell barrier functionality, nitric oxide production and cell metabolism (ATP levels in serum starved conditions were found. The functionality of the peptide was then examined when conjugated to collagen-chitosan hydrogel, a potential carrier for in vivo application. The presence of the peptide in the hydrogel mitigated paclitaxel induced apoptosis of endothelial cells in a dose dependent manner. Furthermore, the peptide modified hydrogels stimulated tube-like structure formation of encapsulated endothelial cells. When integrin αvβ3 or α5β1 were antibody blocked during cell encapsulation in peptide modified hydrogels, tube formation was abolished. Therefore, the dual protective nature of the novel peptide QHREDGS may position this peptide as an appealing augmentation for collagen-chitosan hydrogels that could be used for biomaterial delivered cell therapies in the settings of myocardial infarction.

  13. QHREDGS enhances tube formation, metabolism and survival of endothelial cells in collagen-chitosan hydrogels.

    Science.gov (United States)

    Miklas, Jason W; Dallabrida, Susan M; Reis, Lewis A; Ismail, Nesreen; Rupnick, Maria; Radisic, Milica

    2013-01-01

    Cell survival in complex, vascularized tissues, has been implicated as a major bottleneck in advancement of therapies based on cardiac tissue engineering. This limitation motivates the search for small, inexpensive molecules that would simultaneously be cardio-protective and vasculogenic. Here, we present peptide sequence QHREDGS, based upon the fibrinogen-like domain of angiopoietin-1, as a prime candidate molecule. We demonstrated previously that QHREDGS improved cardiomyocyte metabolism and mitigated serum starved apoptosis. In this paper we further demonstrate the potency of QHREDGS in its ability to enhance endothelial cell survival, metabolism and tube formation. When endothelial cells were exposed to the soluble form of QHREDGS, improvements in endothelial cell barrier functionality, nitric oxide production and cell metabolism (ATP levels) in serum starved conditions were found. The functionality of the peptide was then examined when conjugated to collagen-chitosan hydrogel, a potential carrier for in vivo application. The presence of the peptide in the hydrogel mitigated paclitaxel induced apoptosis of endothelial cells in a dose dependent manner. Furthermore, the peptide modified hydrogels stimulated tube-like structure formation of encapsulated endothelial cells. When integrin αvβ3 or α5β1 were antibody blocked during cell encapsulation in peptide modified hydrogels, tube formation was abolished. Therefore, the dual protective nature of the novel peptide QHREDGS may position this peptide as an appealing augmentation for collagen-chitosan hydrogels that could be used for biomaterial delivered cell therapies in the settings of myocardial infarction. PMID:24013716

  14. Salt effects in the formation of self-assembled lithocholate helical ribbons and tubes.

    Science.gov (United States)

    Terech, Pierre; K P Velu, Sabareesh; Pernot, Petra; Wiegart, Lutz

    2012-09-13

    The formation of self-assembled nanotubes is usually accounted for by anisotropic elastic properties of membranelike precursors. We present experimental data as evidence of the role played by electrostatics in the formation of self-assembled tubes in alkaline aqueous suspensions of lithocholic acid (LCA). Striking salt effects are characterized by comparing the rheological, dynamical, and scattering properties of systems prepared either in stoichiometric neutralization conditions (SC) of LCA or in a large excess of sodium hydroxide (EOC, experimentally optimized conditions) and finally, in two steps: stoichiometric neutralization followed by an appropriate addition of NaCl (AISC). The SC liquid system is originally made up of loose helical ribbons (previous transmission electron microscopy data), and upon aging they exhibit both intra- and interordering processes. Initially, the helical ribbons are loose and progressively wind around a cylinder (R = 330 Å) with their edges exposed to the solvent. They can be temporarily organized in a centered rectangular two-dimensional lattice (pgg, a = 224 Å, b = 687 Å). Upon further aging, the ribbons wind into more compact helical ribbons (or tubes with helical grooves): their edges are less-exposed and their ordering vanishes. Upon addition of NaCl salt (as in the AISC systems), the specific screening of the intra-aggregate electrostatic repulsions induces the closure of the ribbons into tubes (R(ext) = 260 Å, R(int) = 245 Å as in the EOC systems). Simultaneously with the closure of the ribbons into plain tubes, a drastic enhancement of their interconnectivity through van der Waals attractions develops. Eventually, gels are obtained with networks having hexagonal bundles of tubes. PMID:22905756

  15. Detection of blister formation and evaluation of pressure tube/calandria tube contact location by ultrasonic velocity ratio measurement technique

    International Nuclear Information System (INIS)

    Presence of hydrogen in zircaloy pressure tube affects the velocity of ultrasound propagation. Both longitudinal wave velocity (VL) and shear wave velocity (VS) are affected depending on the concentration of hydrogen. Velocity ratio (VL/VS) changes as per the concentrations of hydrogen in different locations along the length of pressure tube. A hydride blister which forms at the pressure tube and calandria tube contact point is a distinct zone containing hydrogen 2-3 order of magnitude more than the parent matrix and hence, can be detected by sharp change in velocity ratio. (author)

  16. Actinide oxalate complexes formation as a function of temperature by capillary electrophoresis coupled with inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Brunel, Benoit; Mendes, Mickael; Aupiais, Jean [CEA, DAM, DIF, Arpajon (France); Philippini, Violaine [Nice Univ. Sophia Antipolis (France). Inst. de Chimie de Nice

    2015-05-01

    Complexation of various actinides (U(VI), Np(V), Pu(V), Am(III)) by oxalato ligand was studied by capillary electrophoresis (ICPMS detection) in 0.1 mol L{sup -1} NaClO{sub 4} ionic strength solutions at various temperatures (15, 25, 35, 45 and 55 C). For each solution a unique peak was observed as a result of a fast equilibrium between the free ions and the complexes (labile systems). The results confirmed the formation of the 1:1, 1:2 and 1:3 complexes for U(VI) and Am(III); the formation of the 1:1 and 1:2 complexes for Np(V) and the formation of only 1 complex for Pu(V). For each complex, the thermodynamic parameters (the Gibbs energy Δ{sub r}G(T), the molar entropy change Δ{sub r}S(T) and the molar enthalpy change Δ{sub r}H(T{sup 0})) were fitted to the experimental data. The effect of the ionic medium was treated using the specific ion interaction theory and the thermodynamic parameters at zero ionic strength were compared to previously published data.

  17. Effect of steroid hormones and retinoids on the formation of capillary-like tubular structures of human microvascular endothelial cells in fibrin matrices is related to urokinase expression

    NARCIS (Netherlands)

    Lansink, M.; Koolwijk, P.; Hinsbergh, V. van; Kooistra, T.

    1998-01-01

    Angiogenesis, the formation of new capillary blood vessels, is a feature of a variety of pathological processes. To study the effects of a specific group of hormones (all ligands of the steroid/retinoid/thyroid hormone receptor superfamily) on the angiogenic process in humans, we have used a model s

  18. Protective Effects of N-Acetyl Cysteine against Diesel Exhaust Particles-Induced Intracellular ROS Generates Pro-Inflammatory Cytokines to Mediate the Vascular Permeability of Capillary-Like Endothelial Tubes.

    Directory of Open Access Journals (Sweden)

    Chia-Yi Tseng

    Full Text Available Exposure to diesel exhaust particles (DEP is associated with pulmonary and cardiovascular diseases. Previous studies using in vitro endothelial tubes as a simplified model of capillaries have found that DEP-induced ROS increase vascular permeability with rearrangement or internalization of adherens junctional VE-cadherin away from the plasma membrane. This allows DEPs to penetrate into the cell and capillary lumen. In addition, pro-inflammatory cytokines are up-regulated and mediate vascular permeability in response to DEP. However, the mechanisms through which these DEP-induced pro-inflammatory cytokines increase vascular permeability remain unknown. Hence, we examined the ability of DEP to induce permeability of human umbilical vein endothelial cell tube cells to investigate these mechanisms. Furthermore, supplementation with NAC reduces ROS production following exposure to DEP. HUVEC tube cells contributed to a pro-inflammatory response to DEP-induced intracellular ROS generation. Endothelial oxidative stress induced the release of TNF-α and IL-6 from tube cells, subsequently stimulating the secretion of VEGF-A independent of HO-1. Our data suggests that DEP-induced intracellular ROS and release of the pro-inflammatory cytokines TNF- α and IL-6, which would contribute to VEGF-A secretion and disrupt cell-cell borders and increase vasculature permeability. Addition of NAC suppresses DEP-induced ROS efficiently and reduces subsequent damages by increasing endogenous glutathione.

  19. 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.

  20. CD151 gene delivery increases eNOS activity and induces ECV304 migration, proliferation and tube formation

    Institute of Scientific and Technical Information of China (English)

    Zhen-zhong ZHENO; Zheng-xiang LIU

    2007-01-01

    Aim: To investigate the effects of CD151 on the activity of endothelial NO syn-thase (eNOS), and ECV304 migration, proliferation and tube formation. Methods:pAAV-CD151 and pAAV-anti-CD151 were constructed and used to transiently transfect ECV304 mediated with Lipofectamine 2000. After transfection, the ex-pression of CD151 was measured by Western blotting. Cell migration assay was performed using Boyden transwell; proliferation assay was evaluated using the 3-[4,5-dimethylthiazol-2-yl]-2,5, diphenyltetrazolium bromide (MTT) method, and tube formation test was examined on matrigel, eNOS activity was assayed by L-[3H]citrulline production from L-[3H]arginine. The involvement of eNOS was ex-plored using an eNOS inhibitor (L-NAME) and the effects in the process were observed. Results: CD151 promotes cell migration, proliferation and tube formation.In addition, CD151 increases eNOS activity. Moreover, cell migration, prolifera-tion and tube formation induced by CD151 are inhibited when L-NAME is used,which indicates that there is an involvement of eNOS in CD151-induced cell migration, cell proliferation and tube formation. Conclusion: CD151 promotes ECV304 migration, proliferation and tube formation. The mechanism is that CD151 increases eNOS activity. This result also suggests that eNOS is involved in the angiogenic effects of CD151.

  1. Rapamycin Inhibits Lymphatic Endothelial Cell Tube Formation by Downregulating Vascular Endothelial Growth Factor Receptor 3 Protein Expression

    Directory of Open Access Journals (Sweden)

    Yan Luo

    2012-03-01

    Full Text Available Mammalian target of rapamycin (mTOR controls lymphangiogenesis. However, the underlying mechanism is not clear. Here we show that rapamycin suppressed insulin-like growth factor 1 (IGF-1- or fetal bovine serum (FBS-stimulated lymphatic endothelial cell (LEC tube formation, an in vitro model of lymphangiogenesis. Expression of a rapamycin-resistant and kinase-active mTOR (S2035T, mTOR-T, but not a rapamycin-resistant and kinase-dead mTOR (S2035T/D2357E, mTOR-TE, conferred resistance to rapamycin inhibition of LEC tube formation, suggesting that rapamycin inhibition of LEC tube formation is mTOR kinase activity dependent. Also, rapamycin inhibited proliferation and motility in the LECs. Furthermore, we found that rapamycin inhibited protein expression of VEGF receptor 3 (VEGFR-3 by inhibiting protein synthesis and promoting protein degradation of VEGFR-3 in the cells. Down-regulation of VEGFR-3 mimicked the effect of rapamycin, inhibiting IGF-1- or FBS-stimulated tube formation, whereas over-expression of VEGFR-3 conferred high resistance to rapamycin inhibition of LEC tube formation. The results indicate that rapamycin inhibits LEC tube formation at least in part by downregulating VEGFR-3 protein expression.

  2. Wire-in-tube structure fabricated by single capillary electrospinning via nanoscale Kirkendall effect: the case of nickel-zinc ferrite

    Science.gov (United States)

    Fu, Jiecai; Zhang, Junli; Peng, Yong; Zhao, Changhui; He, Yongmin; Zhang, Zhenxing; Pan, Xiaojun; Mellors, Nigel J.; Xie, Erqing

    2013-11-01

    Wire-in-tube structures have previously been prepared using an electrospinning method by means of tuning hydrolysis/alcoholysis of a precursor solution. Nickel-zinc ferrite (Ni0.5Zn0.5Fe2O4) nanowire-in-nanotubes have been prepared as a demonstration. The detailed nanoscale characterization, formation process and magnetic properties of Ni0.5Zn0.5Fe2O4 nanowire-in-nanotubes has been studied comprehensively. The average diameters of the outer tubes and inner wires of Ni0.5Zn0.5Fe2O4 nanowire-in-nanotubes are around 120 nm and 42 nm, respectively. Each fully calcined individual nanowire-in-nanotube, either the outer-tube or the inner-wire, is composed of Ni0.5Zn0.5Fe2O4 monocrystallites stacked along the longitudinal direction with random orientation. The process of calcining electrospun polymer composite nanofibres can be viewed as a morphologically template nucleation and precursor diffusion process. This allows the nitrates precursor to diffuse toward the surface of the nanofibres while the oxides (decomposed from hydroxides and nitrates) products diffuse to the core region of the nanofibres; the amorphous nanofibres transforming thereby into crystalline nanowire-in-nanotubes. In addition, the magnetic properties of the Ni0.5Zn0.5Fe2O4 nanowire-in-nanotubes were also examined. It is believed that this nanowire-in-nanotube (sometimes called core-shell) structure, with its uniform size and well-controlled orientation of the long nanowire-in-nanotubes, is particularly attractive for use in the field of nano-fluidic devices and nano-energy harvesting devices.Wire-in-tube structures have previously been prepared using an electrospinning method by means of tuning hydrolysis/alcoholysis of a precursor solution. Nickel-zinc ferrite (Ni0.5Zn0.5Fe2O4) nanowire-in-nanotubes have been prepared as a demonstration. The detailed nanoscale characterization, formation process and magnetic properties of Ni0.5Zn0.5Fe2O4 nanowire-in-nanotubes has been studied comprehensively. The

  3. Oxidized LDL signals through Rho-GTPase to induce endothelial cell stiffening and promote capillary formation.

    Science.gov (United States)

    Oh, Myung-Jin; Zhang, Chongxu; LeMaster, Elizabeth; Adamos, Crystal; Berdyshev, Evgeny; Bogachkov, Yedida; Kohler, Erin E; Baruah, Jugajyoti; Fang, Yun; Schraufnagel, Dean E; Wary, Kishore K; Levitan, Irena

    2016-05-01

    Endothelial biomechanics is emerging as a key factor in endothelial function. Here, we address the mechanisms of endothelial stiffening induced by oxidized LDL (oxLDL) and investigate the role of oxLDL in lumen formation. We show that oxLDL-induced endothelial stiffening is mediated by CD36-dependent activation of RhoA and its downstream target, Rho kinase (ROCK), via inhibition of myosin light-chain phosphatase (MLCP) and myosin light-chain (MLC)2 phosphorylation. The LC-MS/MS analysis identifies 7-ketocholesterol (7KC) as the major oxysterol in oxLDL. Similarly to oxLDL, 7KC induces RhoA activation, MLCP inhibition, and MLC2 phosphorylation resulting in endothelial stiffening. OxLDL also facilitates formation of endothelial branching networks in 3D collagen gels in vitro and induces increased formation of functional blood vessels in a Matrigel plug assay in vivo. Both effects are RhoA and ROCK dependent. An increase in lumen formation was also observed in response to pre-exposing the cells to 7KC, an oxysterol that induces endothelial stiffening, but not to 5α,6α epoxide that does not affect endothelial stiffness. Importantly, loading cells with cholesterol prevented oxLDL-induced RhoA activation and the downstream signaling cascade, and reversed oxLDL-induced lumen formation. In summary, we show that oxLDL-induced endothelial stiffening is mediated by the CD36/RhoA/ROCK/MLCP/MLC2 pathway and is associated with increased endothelial angiogenic activity. PMID:26989083

  4. Glioblastoma-derived Leptin Induces Tube Formation and Growth of Endothelial Cells: Comparison with VEGF Effects

    International Nuclear Information System (INIS)

    Leptin is a pleiotropic hormone whose mitogenic and angiogenic activity has been implicated in the development and progression of several malignancies, including brain tumors. In human brain cancer, especially in glioblastoma multiforme (GBM), leptin and its receptor (ObR) are overexpressed relative to normal tissue. Until present, the potential of intratumoral leptin to exert proangiogenic effects on endothelial cells has not been addressed. Using in vitro models, we investigated if GBM can express leptin, if leptin can affect angiogenic and mitogenic potential of endothelial cells, and if its action can be inhibited with specific ObR antagonists. Leptin effects were compared with that induced by the best-characterized angiogenic regulator, VEGF. We found that GBM cell lines LN18 and LN229 express leptin mRNA and LN18 cells secrete detectable amounts of leptin protein. Both lines also expressed and secreted VEGF. The conditioned medium (CM) of LN18 and LN 229 cultures as well as 200 ng/mL pure leptin or 50 ng/mL pure VEGF stimulated proliferation of human umbilical vein endothelial cells (HUVEC) at 24 h of treatment. Mitogenic effects of CM were ~2-fold greater than that of pure growth factors. Furthermore, CM treatment of HUVEC for 24 h increased tube formation by ~5.5-fold, while leptin increased tube formation by ~ 80% and VEGF by ~60% at 8 h. The mitogenic and angiogenic effects of both CM were blocked by Aca 1, a peptide ObR antagonist, and by SU1498, which inhibits the VEGF receptor. The best anti-angiogenic and cytostatic effects of Aca1 were obtained with 10 nM and 25 nM, respectively, while for SU1498, the best growth and angiogenic inhibition was observed at 5 μM. The combination of 5 μM SU1498 and Aca1 at 25 nM (growth inhibition) or at 10 nM (reduction of tube formation) produced superior effects compared with single agent treatments. Our data provide the first evidence that LN18 and LN 229 human GBM cells express leptin mRNA and might produce

  5. 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.

  6. Investigation of energy dissipation due to contact angle hysteresis in capillary effect

    Science.gov (United States)

    Athukorallage, Bhagya; Iyer, Ram

    2016-06-01

    Capillary action or Capillarity is the ability of a liquid to flow in narrow spaces without the assistance of, and in opposition to, external forces like gravity. Three effects contribute to capillary action, namely, adhesion of the liquid to the walls of the confining solid; meniscus formation; and low Reynolds number fluid flow. We investigate the dissipation of energy during one cycle of capillary action, when the liquid volume inside a capillary tube first increases and subsequently decreases while assuming quasi-static motion. The quasi-static assumption allows us to focus on the wetting phenomenon of the solid wall by the liquid and the formation of the meniscus. It is well known that the motion of a liquid on an non-ideal surface involves the expenditure of energy due to contact angle hysteresis. In this paper, we derive the equations for the menisci and the flow rules for the change of the contact angles for a liquid column in a capillary tube at a constant temperature and volume by minimizing the Helmholtz free energy using calculus of variations. We describe the numerical solution of these equations and present results from computations for the case of a capillary tube with 1 mm diameter.

  7. Nuclear translocation of phosphorylated STAT3 regulates VEGF-A-induced lymphatic endothelial cell migration and tube formation

    Energy Technology Data Exchange (ETDEWEB)

    Okazaki, Hideki; Tokumaru, Sho; Hanakawa, Yasushi; Shiraishi, Ken; Shirakata, Yuji; Dai, Xiuju; Yang, Lijun; Tohyama, Mikiko; Hashimoto, Koji [Department of Dermatology, Ehime University Graduate School of Medicine, Toon, Ehime 791-0295 (Japan); Sayama, Koji, E-mail: sayama@m.ehime-u.ac.jp [Department of Dermatology, Ehime University Graduate School of Medicine, Toon, Ehime 791-0295 (Japan)

    2011-09-02

    Highlights: {yields} VEGF-A enhanced lymphatic endothelial cell migration and increased tube formation. {yields} VEGF-A treated lymphatic endothelial cell showed activation of STAT3. {yields} Dominant-negative STAT3 inhibited VEGF-A-induced lymphatic endothelial cell migration and tube formation. -- Abstract: Vascular endothelial growth factor (VEGF) is an endothelial cell-specific growth factor that regulates endothelial functions, and signal transducers and activators of transcription (STATs) are known to be important during VEGF receptor signaling. The aim of this study was to determine whether STAT3 regulates VEGF-induced lymphatic endothelial cell (LEC) migration and tube formation. VEGF-A (33 ng/ml) enhanced LEC migration by 2-fold and increased tube length by 25% compared with the control, as analyzed using a Boyden chamber and Matrigel assay, respectively. Western blot analysis and immunostaining revealed that VEGF-A induced the nuclear translocation of phosphorylated STAT3 in LECs, and this translocation was blocked by the transfection of LECs with an adenovirus vector expressing a dominant-negative mutant of STAT3 (Ax-STAT3F). Transfection with Ax-STAT3F also almost completely inhibited VEGF-A-induced LEC migration and tube formation. These results indicate that STAT3 is essential for VEGF-A-induced LEC migration and tube formation and that STAT3 regulates LEC functions.

  8. Effects of brefeldin A on the endomembrane system and germ tube formation of the tetraspore of Gelidium floridanum (Rhodophyta, Florideophyceae).

    Science.gov (United States)

    Simioni, Carmen; Rover, Ticiane; Schmidt, Éder C; de L Felix, Marthiellen R; Polo, Luz Karime; Santos, Rodrigo Dos; Costa, Giulia Burle; Kreusch, Marianne; Pereira, Debora T; Ouriques, Luciane C; Bouzon, Zenilda L

    2014-06-01

    Gelidium floridanum W.R. Taylor tetraspores are units of dispersal and are responsible for substrate attachment. This study aimed to examine evidence of direct interaction between germ tube formation and Golgi activity during tetraspore germination of G. floridanum. After release, the tetraspores were incubated with brefeldin A (BFA) in concentrations of 4 and 8 μM over a 6 h period. The controls and treatments were analyzed with light, fluorescence (FM4-64 dye) and transmission electron microscopy. In the control samples, the Golgi bodies were responsible for germ tube formation. In contrast, BFA-treated samples were observed to inhibit spore adhesion and germ tube formation. These tetraspores also showed an increase in volume (≥30 μm width). BFA treatment also resulted in the disassembly of Golgi cisternae and the formation of vesiculated areas of the cytoplasm, blocking the secretion of protein and amorphous matrix polysaccharides. When stained with FM4-64, the control samples showed fluorescence in the apical region of the germ tube, but the treated samples showed an intense fluorescence throughout the cytoplasm. From these results, we can conclude that the germ tube is formed by the incorporation of vesicles derived from Golgi. Thus, vesicle secretion and Golgi organization are basic processes and essential in adhesion and tube formation. By blocking the secretion of protein and amorphous matrix polysaccharides, BFA treatment precluded tetraspore germination. PMID:26988329

  9. Decreased Pseudomonas aeruginosa biofilm formation on nanomodified endotracheal tubes: a dynamic lung model

    Science.gov (United States)

    Machado, Mary C; Webster, Thomas J

    2016-01-01

    Ventilator-associated pneumonia (VAP) is a serious complication of mechanical ventilation that has been shown to be associated with increased mortality rates and medical costs in the pediatric intensive care unit. Currently, there is no cost-effective solution to the problems posed by VAP. Endotracheal tubes (ETTs) that are resistant to bacterial colonization and that inhibit biofilm formation could provide a novel solution to the problems posed by VAP. The objective of this in vitro study was to evaluate differences in the growth of Pseudomonas aeruginosa on unmodified polyvinyl chloride (PVC) ETTs and on ETTs etched with a fungal lipase, Rhizopus arrhizus, to create nanoscale surface features. These differences were evaluated using an in vitro model of the pediatric airway to simulate a ventilated patient in the pediatric intensive care unit. Each experiment was run for 24 hours and was supported by computational models of the ETT. Dynamic conditions within the ETT had an impact on the location of bacterial growth within the tube. These conditions also quantitatively affected bacterial growth especially within the areas of tube curvature. Most importantly, experiments in the in vitro model revealed a 2.7 log reduction in the number (colony forming units/mL) of P. aeruginosa on the nanoroughened ETTs compared to the untreated PVC ETTs after 24 hours. This reduction in total colony forming units/mL along the x-axis of the tube was similar to previous studies completed for Staphylococcus aureus. Thus, this dynamic study showed that lipase etching can create surface features of nanoscale roughness on PVC ETTs that decrease bacterial attachment of P. aeruginosa without the use of antibiotics and may provide clinicians with an effective and inexpensive tool to combat VAP. PMID:27563242

  10. Confirmation of vanadium complex formation using electrospray mass spectrometry and determination of vanadium speciation by sample stacking capillary electrophoresis

    International Nuclear Information System (INIS)

    Capillary zone electrophoresis (CZE) with UV detection was used to determine vanadium species. Nitrilotriacetic acid (NTA), hydroxyethylethylenediaminetriacetic acid (HEDTA), ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), ethylene glycol-bis(2-aminoethylether)-tetraacetic acid (EGTA) and 2,6-pyridinedicarboxylic acid (PDCA) were investigated to determine whether these ligands formed stable anionic complexes with vanadium. Of all the ligands studied HEDTA was the most suitable ligand because it gave the largest UV response with reasonable migration time. Electrospray mass spectrometry (ES-MS) was used to confirm the formation of [VO2(HEDTA)]2- and [VO(HEDTA)]1- in solution. An electrolyte containing 25 mM phosphate, 0.25 mM tetradecyltrimethylammonium bromide (TTAB) at pH 5.5 was optimum for the separation of these anionic vanadium complexes. Sample stacking techniques, including large-volume sample stacking (LVSS) and field-amplified sample injection (FASI), were tested to improve the sensitivity. Best sensitivity was obtained using FASI, with detection limits of 0.001 μM, equivalent to 0.4 μg L-1, for [VO2(HEDTA)]2- and 0.01 μM, equivalent to 3.4 μg L-1 for [VO(HEDTA)]1-. The utility of the method for the speciation of V(IV) and V(V) was demonstrated using ground water samples

  11. 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...

  12. 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.

  13. Inhibition of germ tube's formation of Candida albicans by lactobacillus spp.

    Institute of Scientific and Technical Information of China (English)

    TANG Huan; WEI Hong

    2006-01-01

    Objective:To investigate the effects of 6 strains of lactobacilli and their main culture metabolites on the morphogenesis of Candida albicans (C. albicans) so as to screen medicinal strains as antifungal agents. Methods: Spent culture supernatant (SCS) at different culture time points, live lactobacilli, heatkilled bacteria and bacterial short-chain fatty acids (SCFA) with different molarities were incubated with C. albicans respectively. Crystal violet-based germ tube assay was used to detect the germination of C. albicans and the inhibitory efficiency of each addition was tested by germination rate. Results: SCS of lactobacillus spp. decreased the germination significantly and live bacteria of L. rhamnosus. GG, L. acidophilus L050103-12 as well as L. johnsonii JCM1022 could partially inhibit the conversion, however, all the heatkilled bacteria failed to control the germ tube formation. In addition, only butyric acid blocked the conversion of yeast to hypha among all the SCFA. Conclusion: The excellent fungistasis activities make L.rhamnosus. GG, L. acidophilus L050103-12 and L. johnsonii JCM1022 potential strains as antifungal drugs and the inhibition seems to have direct correlation to the metabolites.

  14. IL-20 activates human lymphatic endothelial cells causing cell signalling and tube formation

    DEFF Research Database (Denmark)

    Hammer, Troels; Tritsaris, Katerina; Hübschmann, Martin V;

    2009-01-01

    IL-20 is an arteriogenic cytokine that remodels collateral networks in vivo, and plays a role in cellular organization. Here, we investigate its role in lymphangiogenesis using a lymphatic endothelial cell line, hTERT-HDLEC, which expresses the lymphatic markers LYVE-1 and podoplanin. Upon...... IL-20 induced phosphorylation of Erk1/2 and mTOR, and using the MEK inhibitor PD98059 and mTOR complex inhibitor rapamycin we demonstrated the importance of these signalling pathways in IL-20-mediated proliferation. IL-20 triggered actin polymerization and morphological changes resulting in elongated...... cell structures, and in matrigels, IL-20 caused tube formations of hTERT-HDLEC in a PI3K- and mTOR dependent way. In a sprouting assay we found that IL-20 caused cell migration within 24 h at a rate comparable to VEGF-C, and this migration could be inhibited by wortmannin and rapamycin. These data show...

  15. In-capillary formation of polymer/surfactant complexes-assisted reversed-migration micellar electrokinetic chromatography for facile analysis of neutral steroids.

    Science.gov (United States)

    Wu, Li-Chen; Hu, Ching-Yuan; Dung, Yi-Shiou; Wu, Tsung-Hung

    2013-03-30

    In this study we developed a novel approach, using in-capillary formation of polymer/surfactant complexes (IPSC)-assisted reversed-migration MEKC (RM-MEKC), for the analysis of neutral steroids. This process involved two sequential events: in-capillary polymer/surfactant complexes formation during sample preconcentration, followed by IPSC separation. The procedure began with a polymer-filled capillary. Initially, on-line preconcentration of the sample was performed at the sample plug. Meanwhile, free surfactants migrated to interact with polymers, forming polymer-surfactant complexes. Analytes were then kinetically partitioned between the mixed phases (micelles and polymer-SDS complexes). Sodium dodecyl sulfate (SDS) and poly(N-isopropylacrylamide) (PNIPAAm) were employed as pseudo-stationary phases (PSPs). This system allowed the successful separation of five steroids (testosterone, hydrocortisone 21-acetate, dexamethasone, prednisolone, hydrocortisone) in acetate buffer and the determination of urinary free hydrocortisone; it also exhibited excellent performance for sample on-line concentration. The limit of detection for hydrocortisone was 20.98 ng/mL (R(2)=0.9995). The polymer size, concentrations, end-group charges, and SDS concentrations were evaluated. This IPSC/RM-MEKC system, which can be adopted in commercial CE instruments, is easy to operate, suitable for combination with several sample preconcentration options, sensitive, robust, and environmentally sustainable. We suspect that such systems might have potential applications in clinical analyses and in microanalytical devices. PMID:23598239

  16. CONCENTRIC TUBE-FOULING RIG FOR INVESTIGATION OF FOULING DEPOSIT FORMATION FROM PASTEURISER OF VISCOUS FOOD LIQUID

    Directory of Open Access Journals (Sweden)

    N. I. KHALID

    2013-02-01

    Full Text Available This paper reports the work on developing concentric tube-fouling rig, a new fouling deposit monitoring device. This device can detect and quantify the level of fouling deposit formation. It can also functioning as sampler for fouling deposit study, which can be attached at any food processing equipment. The design is initiated with conceptual design. The rig is designed with inner diameter of 7 cm and with tube length of 37 cm. A spiral insert with 34.5 cm length and with 5.4 cm diameter is fitted inside the tube to ensure the fluid flows around the tube. In this work, the rig is attached to the lab-scale concentric tube-pasteurizer to test its effectiveness and to collect a fouling sample after pasteurization of pink guava puree. Temperature changes are recorded during the pasteurization and the data is used to plot the heat transfer profile. Thickness of the fouling deposit is also measured. The trends for thickness, heat resistance profile and heat transfer profile for concentric tube-fouling rig matched the trends obtained from lab-scale concentric tube-pasteurizer very well. The findings from this work have shown a good potential of this rig however there is a limitation with spiral insert, which is discussed in this paper.

  17. 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

  18. Supported liquid membrane extraction coupled in-line to commercial capillary electrophoresis for rapid determination of formate in undiluted blood samples.

    Science.gov (United States)

    Pantůčková, Pavla; Kubáň, Pavel; Boček, Petr

    2013-07-19

    A cheap, disposable sample pretreatment device with planar supported liquid membrane (SLM) was proposed, assembled and placed into an autosampler carousel of a commercial capillary electrophoresis (CE) instrument for automated pretreatment and analysis of formate in undiluted whole blood and serum samples. All analytical procedures except for filling the pretreatment device with donor and acceptor solutions, i.e., extraction across SLM, injection of the extracted sample and CE-UV determination of formate, were performed fully automatically. The pretreatment device required only μL volumes of blood sample and organic solvent per extraction and was disposed off after each extraction. Good repeatability of peak areas (≤7.7%) and migration times (≤1.5%), linear relationship (r(2)=0.998-0.999) and limits of detection (≤35μM) were achieved. The overall analytical process including blood withdrawal, filling the SLM device with respective solutions, extraction of blood sample, injection into separation capillary and CE separation of formate from other anions took less than 4min. The method was proved useful by direct determination of elevated formate concentrations in undiluted serum samples of a methanol intoxicated patient. Due to its compatibility with currently commercially available CE instrumentation, disposability of extraction devices, minimum sample handling/consumption, and short extraction/analysis times, the developed method might be attractive for rapid diagnosis of methanol poisoning in clinical and toxicological laboratories. PMID:23777836

  19. Formation of High Aspect Ratio TiO2 Nano tube Arrays by Anodization of Ti Foil in Organic Solution

    International Nuclear Information System (INIS)

    Titanium oxide (TiO2) nano tubes were successfully formed by anodization of pure titanium foil in a standard two-electrode bath consisting of ethylene glycol solution containing 5 wt % NH4F. The pH of the solution was ∼7 and the anodization voltage was 60 V. It was observed that such anodization condition results in ordered arrays of TiO2 nano tubes with smooth surface and a very high aspect ratio. It was observed that a minimum of 1 wt % water addition was required to form well ordered TiO2 nano tubes with length of approximately 18.5 μm. As-anodized sample, the self-organized TiO2 nano tubes have amorphous structure and annealing at 500 degree Celsius of the nano tubes promote formation of anatase and rutile phase. Photo catalytic activity of well ordered TiO2 nano tubes with two different lengths was evaluated by measuring the degradation of methyl orange (MO). The elaboration of this observation is described in detail in this paper. (author)

  20. Growth Temperature Effect on Carbon Nano tubes Formation by Spray Pyrolysis Method

    International Nuclear Information System (INIS)

    Carbon nano tubes has been produced by using spray pyrolysis method with no carrier gas. Carbon nano tubes were formulated from a mixture a ferrocene and benzene with certain ratio and then the mixture were injected by the sprayer into the furnace. Growth temperature was optimized in the range of 650 until 850 oC to get the high quality of carbon nano tubes. These were characterized by Scanning Electron Microscope (SEM) and Energy Dispersive X-ray (EDX). (author)

  1. Formation and characterization of hydride blisters in Zircaloy-4 cladding tubes

    Energy Technology Data Exchange (ETDEWEB)

    Hellouin de Menibus, Arthur, E-mail: arthur.hellouin-de-menibus@cea.fr [French Atomic Energy Comission - CEA Saclay/DEN/DANS/DMN/SRMA, 91191 Gif-sur-Yvette (France); Mines ParisTech/Centre des matériaux, CNRS UMR 7633, 91003 Evry (France); Auzoux, Quentin; Dieye, Ousmane [French Atomic Energy Comission - CEA Saclay/DEN/DANS/DMN/SEMI, 91191 Gif-sur-Yvette (France); Berger, Pascal [French Atomic Energy Comission - CEA Saclay/DSM/IRAMIS/SIS2M, 91191 Gif-sur-Yvette (France); CNRS UMR 3299, CEA-Saclay, 91191 Gif-sur-Yvette (France); Bosonnet, Sophie [French Atomic Energy Comission - CEA Saclay/DEN/DANS/DMN/SRMA, 91191 Gif-sur-Yvette (France); Foy, Eddy [French Atomic Energy Comission - CEA Saclay/DSM/IRAMIS/SIS2M, 91191 Gif-sur-Yvette (France); CNRS UMR 3299, CEA-Saclay, 91191 Gif-sur-Yvette (France); Macdonald, Vincent [French Atomic Energy Comission - CEA Saclay/DEN/DANS/DMN/SEMI, 91191 Gif-sur-Yvette (France); Besson, Jacques; Crépin, Jerome [Mines ParisTech/Centre des matériaux, CNRS UMR 7633, 91003 Evry (France)

    2014-06-01

    This article is focused on the formation of hydride blisters in zirconium alloys an experimental and theoretical standpoint, and their characterization in terms of morphology, hydrides crystallographic phases, hardness and hydrogen concentration. An experimental setup was developed to grow hydride blisters on pre-hydrided Zircaloy-4 cladding tubes by thermo-diffusion. The thermal conditions were optimized based on thermo-diffusion calculations, that take into account the hysteresis in the hydrogen solubility limit, to obtain a high blister growth rate. Micro-X-ray Diffraction (XRD), nano-hardness and Elastic Recoil Detection Analysis (ERDA) showed that the blisters contain a hydrogen gradient, with pure δ-hydride phase close to the external surface over one third of the blister depth. Thermo-diffusion calculations showed these half thickness blisters should grow in only a few days in PWR conditions. Eventually, the Diffusion Equilibrium Threshold (DET) was defined as a criterion that limits the blister growth, and emphasizes that the hysteresis in the hydrogen solubility limit in zirconium must be taken into account to model hydrogen thermo-diffusion in zirconium alloys.

  2. Formation and characterization of hydride blisters in Zircaloy-4 cladding tubes

    International Nuclear Information System (INIS)

    This article is focused on the formation of hydride blisters in zirconium alloys an experimental and theoretical standpoint, and their characterization in terms of morphology, hydrides crystallographic phases, hardness and hydrogen concentration. An experimental setup was developed to grow hydride blisters on pre-hydrided Zircaloy-4 cladding tubes by thermo-diffusion. The thermal conditions were optimized based on thermo-diffusion calculations, that take into account the hysteresis in the hydrogen solubility limit, to obtain a high blister growth rate. Micro-X-ray Diffraction (XRD), nano-hardness and Elastic Recoil Detection Analysis (ERDA) showed that the blisters contain a hydrogen gradient, with pure δ-hydride phase close to the external surface over one third of the blister depth. Thermo-diffusion calculations showed these half thickness blisters should grow in only a few days in PWR conditions. Eventually, the Diffusion Equilibrium Threshold (DET) was defined as a criterion that limits the blister growth, and emphasizes that the hysteresis in the hydrogen solubility limit in zirconium must be taken into account to model hydrogen thermo-diffusion in zirconium alloys

  3. Formation of corrosion products protecting surfaces of the boiler proper tubes from the combustion chamber

    OpenAIRE

    Pietrzyk, M.; S. Król

    2007-01-01

    Purpose: The aim of this paper is to determine how the oxidation product layer of the steel applied for the radiant tubes should increase if we are going to obtain the lowest possible corrosion losses.Design/methodology/approach: Boiler tubes, made of 13CrMo4-5 steel were subjected to tests. In the boiler BP-1150, the tubes ø 30 x 5 mm are joined by fins and form a membrane shield. According to the maps of tube wall thickness, in the zone of the highest heat load, sectors of the shield were s...

  4. Study of solvent effects on formation of dibenzo-18crown-6 complex with alkali metal ions by affinity capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Konášová, Renáta; Jaklová Dytrtová, Jana; Kašička, Václav

    Helsinki: -, 2015. YS2. [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) GA15-01948S Institutional support: RVO:61388963 Keywords : solvent effect * stability constant * affinity capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation

  5. Some aspects of the electrochemical formation of carbon micro-tubes from molten chlorides

    Directory of Open Access Journals (Sweden)

    Yaghmaee M.S.

    2003-01-01

    Full Text Available Carbon nano/micro-tubes have been successfully synthesized by an electrochemical way from the NaCl-KCl-5% MgCl2 molten salt on the surface of a graphite cathode. The length of the tubes is above 100 µm, while their diameter ranges from hundreds of nanometers to 1-2 µm. A new cleaning procedure of the carbon tubes from the remaining salt has been developed with acetone found to be the best cleaning agent. It has been shown that in addition to carbon micro-tubes, some tube-like or rod-like structures can be formed, which do not actually consist of carbon but of the remained salt.

  6. 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…

  7. Shock tube/laser absorption studies of the decomposition of methyl formate

    KAUST Repository

    Ren, Wei

    2013-01-01

    Reaction rate coefficients for the major high-temperature methyl formate (MF, CH3OCHO) decomposition pathways, MF → CH3OH + CO (1), MF →CH2O+CH2O (2), and MF→ CH4 + CO2 (3), were directly measured in a shock tube using laser absorption of CO (4.6 μm), CH2O (306 nm) and CH4 (3.4 μm). Experimental conditions ranged from 1202 to 1607 K and 1.36 to 1.72 atm, with mixtures varying in initial fuel concentration from 0.1% to 3% MF diluted in argon. The decomposition rate coefficients were determined by monitoring the formation rate of each target species immediately behind the reflected shock waves and modeling the species time-histories with a detailed kinetic mechanism [12]. The three measured rate coefficients can be well-described using two-parameter Arrhenius expressions over the temperature range in the present study: k1 = 1.1 × 1013 exp(-29556/T, K) s -1, k2 = 2.6 × 1012 exp(-32052/T, K) s-1, and k3 = 4.4 × 1011 exp(-29 078/T, K) s-1, all thought to be near their high-pressure limits. Uncertainties in the k1, k2 and k3 measurements were estimated to be ±25%, ±35%, and ±40%, respectively. We believe that these are the first direct high-temperature rate measurements for MF decomposition and all are in excellent agreement with the Dooley et al. [12] mechanism. In addition, by also monitoring methanol (CH3OH) and MF concentration histories using a tunable CO2 gas laser operating at 9.67 and 9.23 μm, respectively, all the major oxygen-carrying molecules were quantitatively detected in the reaction system. An oxygen balance analysis during MF decomposition shows that the multi-wavelength laser absorption strategy used in this study was able to track more than 97% of the initial oxygen atoms in the fuel. © 2012 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

  8. Blast Wave Formation by Laser-Sustained Nonequilibrium Plasma in the Laser-Driven In-Tube Accelerator Operation

    International Nuclear Information System (INIS)

    Understanding the dynamics of laser-produced plasma is essentially important for increasing available thrust force in a gas-driven laser propulsion system such as laser-driven in-tube accelerator. A computer code is developed to explore the formation of expanding nonequilibrium plasma produced by laser irradiation. Various properties of the blast wave driven by the nonequilibrium plasma are examined. It is found that the blast wave propagation is substantially affected by radiative cooling effect for lower density case

  9. Formation of molecular doping patterns in organic-inorganic hybrid films by a capillary electrophoresis doping technique

    International Nuclear Information System (INIS)

    A new technique is proposed for the fabrication of fine patterns of molecular doping in organic-inorganic hybrid materials by the combination of capillary electrophoresis doping (CED) and photolithography. The UV-induced polymerization of - -- C=C - -- bonds in organic groups yields a fine contrast of structures with the desired pattern in organic-inorganic hybrid films, and CED treatment introduces functional molecules only into unirradiated regions to form the doping patterns of molecules inside the films. The fine patterning of rhodamine-6G doping with from 2 to 4 μm resolution is demonstrated in hybrid films of 10 μm thickness.

  10. The matrix protein CCN1 (CYR61) promotes proliferation, migration and tube formation of endothelial progenitor cells

    International Nuclear Information System (INIS)

    Neovascularization and re-endothelialization relies on circulating endothelial progenitor cells (EPCs), but their recruitment and angiogenic roles are subjected to regulation by the vascular microenvironment, which remains largely unknown. The present study was designed to investigate the effects of mature ECs and matrix protein CCN1 on the properties of EPCs. In a coculture system, effects of ECs on proliferation, migration and participation in tube-like formation of EPCs were evaluated, and functional assays were employed to identify the exact role of CCN1 in EPCs vitality and function. We demonstrated that ECs, as an indispensable part of the cellular milieu, significantly promoted the proliferation, migration and tube formation activities of EPCs, and more importantly, CCN1 was potentially involved in such effects of ECs. Expression of CCN1 in EPCs was significantly increased by serum, VEGF, ECs-cocultivation and ECs conditioned medium. Moreover, Ad-CCN1-mediated overexpression of CCN1 directly enhanced migration and tube formation of EPCs, whereas silencing of endogenous CCN1 in EPCs inhibits cell functions. Furthermore, CCN1 induced the expressions of chemokines and growth factors, such as MCP-1 and VEGF, suggesting a complex interaction between those proangiogenic factors. Our data suggest that matrix protein CCN1 may play an important role in microenvironment-mediated biological properties of EPCs

  11. Assessment of Blasting Performance Using Electronic Vis-à-Vis Shock Tube Detonators in Strong Garnet Biotite Sillimanite Gneiss Formations

    Science.gov (United States)

    Sharma, Suresh Kumar; Rai, Piyush

    2016-04-01

    This paper presents a comparative investigation of the shock tube and electronic detonating systems practised in bench blasting. The blast trials were conducted on overburden rocks of Garnet Biotite Sillimanite Gneiss formations in one of the largest metalliferous mine of India. The study revealed that the choice of detonating system was crucial in deciding the fragment size and its distribution within the blasted muck-piles. The fragment size and its distribution affected the digging rate of excavators. Also, the shape of the blasted muck-pile was found to be related to the degree of fragmentation. From the present work, it may be inferred that in electronic detonation system, timely release of explosive energy resulted in better overall blasting performance. Hence, the precision in delay time must be considered in designing blast rounds in such overburden rock formations. State-of-art image analysis, GPS based muck-pile profile plotting techniques were rigorously used in the investigation. The study revealed that a mean fragment size (K50) value for shock tube detonated blasts (0.55-0.59 m) was higher than that of electronically detonated blasts (0.43-0.45 m). The digging rate of designated shovels (34 m3) with electronically detonated blasts was consistently more than 5000 t/h, which was almost 13 % higher in comparison to shock tube detonated blasts. Furthermore, favourable muck-pile shapes were witnessed in electronically detonated blasts from the observations made on the dozer performance.

  12. Computer simulation of oxide formation in ZR-NB pressure tubes

    International Nuclear Information System (INIS)

    Zr-2.5% Nb alloy pressure tubes are used in the core of CANDU nuclear reactors. During the operation of the reactor, oxidation takes place at both the interior and exterior surfaces of the pressure tube. The oxide film formed on the pressure tube surface serves as a protective barrier against hydrogen ingress. Therefore, it is important to predict and control the oxide texture, microstructure, and grain boundary distribution which ensures safe operation of the reactor. Our earlier research work has been focused on understanding the oxidation mechanism and oxide texture and microstructure development. Recently, efforts have been made to develop software that will eventually allow the prediction of oxide structure development which would result in optimizing the parameters that control the oxide structure. (author)

  13. Formation of polyhedral vesicles and polygonal membrane tubes induced by banana-shaped proteins

    Science.gov (United States)

    Noguchi, Hiroshi

    2015-12-01

    The shape transformations of fluid membranes induced by curved protein rods are studied using meshless membrane simulations. The rod assembly at low rod density induces a flat membrane tube and oblate vesicle. It is found that the polyhedral shapes are stabilized at high rod densities. The discrete shape transition between triangular and buckled discoidal tubes is obtained and their curvature energies are analyzed by a simple geometric model. For vesicles, triangular hosohedron and elliptic-disk shapes are formed in equilibrium, whereas tetrahedral and triangular prism shapes are obtained as metastable states.

  14. Shock wave formation in flame propagation in a gas-air mixture within a tube

    Energy Technology Data Exchange (ETDEWEB)

    Abinov, A.G.; Plotnikov, V.M.; Shebeko, Yu.N.; Eremenko, O.Ya.; Fialkov, B.S.; Muravlev, V.K.; Abramovich, A.L.; Chekhovskikh, A.M.

    1987-07-01

    Attention is given to determination of the inter-relationship of shock and pressure wave parameters (pressure and wave impulse) with the energy contained in the explosive cloud. The experiments were performed in shock tubes. Oscillograms are shown for the cases of strong (blasting cord) and weak (copper wire fuse) initiation. The dependence of shock-wave impulse for strong initiation on the reserve of chemical energy contained in the explosive mixture and on the cross-sectional area of the tube is give. The analogous relationships for weak initiation are shown and interpreted.

  15. 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

  16. Ethanol contamination in commercial buffers: ethanol contaminating tris-maleate and other commercial buffers induces germ tube formation in Candida albicans.

    OpenAIRE

    Pollack, J H; Hashimoto, T

    1984-01-01

    Evidence is presented for the presence of trace amounts of ethanol in certain commercial buffers. It was shown that germ tube formation occurring in Candida albicans suspended in the buffers was due to the contaminating ethanol.

  17. 微重力下圆管毛细流动解析近似解研究%The analytical approximate solutions of capillary flow in circular tubes under microgravity∗

    Institute of Scientific and Technical Information of China (English)

    李永强; 张晨辉; 刘玲; 段俐; 康琦

    2013-01-01

      应用同伦分析法研究微重力环境下圆管毛细流动解析近似解问题,给出了级数解的表达公式。不同于其他解析近似方法,该方法从根本上克服了摄动理论对小参数的过分依赖,其有效性与所研究的非线性问题是否含有小参数无关,适用范围广。同伦分析法提供了选取基函数的自由,可以选取较好的基函数,更有效地逼近问题的解,通过引入辅助参数和辅助函数来调节和控制级数解的收敛区域和收敛速度,同伦分析法为圆管毛细流动问题的解析近似求解开辟了一个全新的途径。通过具体算例,将同伦分析法与四阶龙格库塔方法数值解做了比较,结果表明,该方法具有很高的计算精度。%The capillary flow in a circular tube under microgravity environment is investigated by the homotopy analysis method (HAM), and the approximate analytical solution in the form of series solution is obtained. Different from other analytical approximate methods, the HAM is totally independent of small physical parameters, and thus it is suitable for most nonlinear problems. The HAM provides us a great freedom to choose basis functions of solution series, so that a nonlinear problem can be approximated more effectively, and it adjusts and controls the convergence region and the convergence rate of the series solution through introducing auxiliary parameter and the auxiliary function. The HAM hews out a new approach to the analytical approximate solutions of capillary flow in a circular tube. Through the specific example and comparing homotopy approximate analytical solution with the numerical solution which is obtained by the fourth-order Runge-Kutta method, the computed result indicate that this method has the good computational accuracy.

  18. 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.

  19. 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

  20. Bulge formation and necking in a polymer tube under dynamic expansion

    DEFF Research Database (Denmark)

    Lindgreen, Britta; Tvergaard, Viggo; Needleman, Alan

    2008-01-01

    imposed loading are prescribed: (i) a pressure that increases linearly with time and (ii) a change in enclosed volume that increases linearly with time. For both loading conditions, an axisymmetric bulge develops on the tube followed by necking in the bulge. The necks propagate in both the circumferential...

  1. Effects of an elastic membrane on tube waves in permeable formations

    Energy Technology Data Exchange (ETDEWEB)

    Liu, H.; Johnson, D.

    1996-10-01

    In this paper, the modified properties were calculated for tube wave propagation in a fluid-filled borehole penetrating a permeable rock due to the presence of a mudcake which forms on the borehole wall. The mudcake was characterized by an impermeable elastic layer. The mudcake partial sealing mechanism was simulated using a finite membrane stiffness. Consequently, it was shown that the mudcake can reduce, but not eliminate, the permeability effects on the tube wave slowness and attenuation. Moreover, this paper discusses a variety of values for the relevant parameters especially the mudcake thickness and membrane stiffness. The important combinations of mudcake parameters were clarified by using an analytic expression for the low-frequency limit.

  2. Formation and growth of hydride blisters in Zr-2.5Nb pressure tubes

    International Nuclear Information System (INIS)

    Hydride blisters were formed on the outer surface of Zr-2.5Nb pressure tube by a nonuniform steady thermal diffusion process. A thermal gradient was applied to the pressure tube with a heat bath kept at a temperature of 415 .deg. C and an aluminum cold finger cooled with flowing water of 15 .deg. C. Optical microscopy and three-dimensional laser profilometry were used to characterize the hydride blisters with different hydrogen concentrations and thermal diffusion time. Hydride blisters were expected to start at a hydrogen concentration of 30 - 70 ppm and a thermal diffusion time of 4 - 6x105 sec. The hydride blister size increases with higher hydrogen concentrations and longer thermal diffusion time. Some of the samples revealed cracks on the hydride blisters. The ratio of hydride blister depth to height was estimated as approximately 8:1

  3. 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)

  4. The formation and characteristics of hydride blisters in c.w. Zircaloy-2 pressure tubes

    International Nuclear Information System (INIS)

    Under the auspices of the IAEA, a consultants' meeting was arranged in Vienna, 1994 July 25-29, at which a Canadian delegation, consisting of AECL and Ontario Hydro Technologies personnel, presented information on their knowledge of the behaviour of hydride blisters in Zircaloy-2 pressure tubes. This document contains the 10 papers presented by the Canadian delegation to the meeting. It is believed that they represent a good reference document on hydride blister phenomena

  5. Modification of narrow ablating capillaries under the influence of multiple femtosecond laser pulses

    CERN Document Server

    Gubin, K V; Trunov, V I; Pestryakov, E V

    2016-01-01

    Powerful femtosecond laser pulses that propagate through narrow ablating capillaries cause modification of capillary walls, which is studied experimentally and theoretically. At low intensities, laser-induced periodic surface structures (LIPSS) and porous coating composed of sub-micron particles appear on the walls. At higher intensities, the surface is covered by deposited droplets of the size up to 10 $\\mu$m. In both cases, the ablated material forms a solid plug that completely blocks the capillary after several hundreds or thousands of pulses. The suggested theoretical model indicates that plug formation is a universal effect. It must take place in any narrow tube subject to ablation under the action of short laser pulses.

  6. In vitro approach to the mechanics of lipid membrane area regulation: vesicle absorption and tube formation

    Science.gov (United States)

    Staykova, Margarita; Holmes, Douglas; Read, Clarke; Stone, Howard A.

    2011-03-01

    We have designed an experimental approach that allows us to study the response of supported lipid bilayers to cycles of biaxial expansion and compression. We observed that the bilayer effectively adjusts its area during dilatational or compressive strains in order to reduce its tension. For example, if there is a sufficient lipid reservoir in the form of attached vesicles, then a lipid bilayer may accommodate strains tens of times larger than the critical strain for rupture by expanding its area. Additionally, upon compression the bilayer reduces its area by expelling lipid tubes out of its plane. These observations offer new insights into how cells regulate their surface area in response to various mechanical stimuli, i.e. during physiological volume changes, locomotion, cyclic expansion and compression of the uro- and the alveolar- epithelium, etc.

  7. α-Naphthoflavone Increases Lipid Accumulation in Mature Adipocytes and Enhances Adipocyte-Stimulated Endothelial Tube Formation

    Directory of Open Access Journals (Sweden)

    Mei-Lin Wang

    2015-04-01

    Full Text Available The aryl hydrocarbon receptor (AhR is a ligand-activated factor that regulates biological effects associated with obesity. The AhR agonists, such as environmental contaminants 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD and β-naphthoflavone (BNF, inhibit preadipocyte differentiation and interfere with the functions of adipose tissue, whereas the antagonist may have opposite or protective effects in obesity. This study investigated the effects of α-naphthoflavone (α-NF, an AhR antagonist, on adipogenesis- and angiogenesis-associated factors in mature adipocytes and on cross-talk of mature adipocytes with endothelial cells (ECs. Besides, the roles of the AhR on lipid accumulation and on secretion of vascular endothelial growth factor were also determined by introducing siRNA of AhR. Differentiated 3T3-L1 cells were treated with α-naphthoflavone (α-NF (1–5 μM for 16 h. Lipid accumulation and the expressions of AhR-associated factors in the cells were determined. The interaction between adipocytes and ECs was investigated by cultivating ECs with conditioned medium (CM from α-NF-treated mature adipocytes, followed by the determination of endothelial tube formation. The results showed that α-NF significantly increased triglyceride (TG accumulation in mature adipocytes, which was associated with increased expression of hormone-sensitive lipase (HSL, estrogen receptor (ER, as well as decreased expression of AhR, AhR nuclear translocator (ARNT, cytochrome P4501B1 (CYP1B1, and nuclear factor erythroid-2-related factor (NRF-2 proteins. In addition, CM stimulated formation of tube-like structures in ECs, and α-NF further enhanced such stimulation in association with modulated the secretions of various angiogenic mediators by mature adipocytes. Similarly, increased TG accumulation and vascular endothelial growth factor (VEGF secretion were observed in AhR-knockout cells. In conclusion, α-NF increased TG accumulation in mature adipocytes and

  8. Hydride blister formation in Zr-2.5wt%Nb pressure tube alloy

    International Nuclear Information System (INIS)

    Hydride blisters were grown over a period of 5-91 days under controlled thermal boundary condition using Zr-2.5wt%Nb pressure tube sections. Rectangular plate type specimens were hydrided to hydrogen concentration in the range of 20-250 ppm by weight and homogenized at 400 deg. C. These specimens were held in a specially fabricated jig capable of producing the required thermal gradients. The bulk specimen and the cold spot temperatures were maintained in the range of 270-400 deg. C and 40-100 deg. C respectively. Depending on the thermal gradients employed, two types of blister morphology were identified. The type I blister was single, round and located at the cold spot region whereas the type II blister consisted of several small blisters along a ring around the cold spot. Microstructural examination of the blister cross-section revealed three regions; a single-phase region consisting of hydrides, a region consisting of matrix containing both radial and circumferential hydrides, and another region consisting of matrix and circumferential hydrides. An attempt was made to rationalize the observed radial-circumferential hydride platelet orientation. Hydride blister growth rates were found to vary strongly with hydrogen concentration and bulk specimen temperature. The observed time for blister growth was found to be in agreement with the Sawatzky's model

  9. In-situ formation of solidified hydrogen thin-membrane targets using a pulse tube cryocooler

    Science.gov (United States)

    Astbury, S.; Bedacht, S.; Brummitt, P.; Carroll, D.; Clarke, R.; Crisp, S.; Hernandez-Gomez, C.; Holligan, P.; Hook, S.; Merchan, J. S.; Neely, D.; Ortner, A.; Rathbone, D.; Rice, P.; Schaumann, G.; Scott, G.; Spindloe, C.; Spurdle, S.; Tebartz, A.; Tomlinson, S.; Wagner, F.; Borghesi, M.; Roth, M.; Tolley, M. K.

    2016-04-01

    An account is given of the Central Laser Facility's work to produce a cryogenic hydrogen targetry system using a pulse tube cryocooler. Due to the increasing demand for low Z thin laser targets, CLF (in collaboration with TUD) have been developing a system which allows the production of solid hydrogen membranes by engineering a design which can achieve this remotely; enabling the gas injection, condensation and solidification of hydrogen without compromising the vacuum of the target chamber. A dynamic sealing mechanism was integrated which allows targets to be grown and then remotely exposed to open vacuum for laser interaction. Further research was conducted on the survivability of the cryogenic targets which concluded that a warm gas effect causes temperature spiking when exposing the solidified hydrogen to the outer vacuum. This effect was shown to be mitigated by improving the pumping capacity of the environment and reducing the minimum temperature obtainable on the target mount. This was achieved by developing a two-stage radiation shield encased with superinsulating blanketing; reducing the base temperature from 14 ± 0.5 K to 7.2 ± 0.2 K about the coldhead as well as improving temperature control stability following the installation of a high-performance temperature controller and sensor apparatus. The system was delivered experimentally and in July 2014 the first laser shots were taken upon hydrogen targets in the Vulcan TAP facility.

  10. Hydrides blister formation and induced embrittlement on zircaloy-4 cladding tubes in reactivity initiated conditions

    International Nuclear Information System (INIS)

    Our aim is to study the cladding fracture with mechanical tests more representative of RIA conditions, taking into account the hydrides blisters, representative strain rates and stress states. To obtain hydride blisters, we developed a thermodiffusion setup that reproduces blister growth in reactor conditions. By metallography, nano-hardness, XRD and ERDA, we showed that they are constituted by 80% to 100% of δ hydrides in a Zircaloy-4 matrix, and that the zirconium beneath has some radially oriented hydrides. We modeled the blister growth kinetics taking into account the hysteresis of the hydrogen solubility limit and defined the thermal gradient threshold for blister growth. The modeling of the dilatometric behavior of hydrided zirconium indicates the important role of the material crystallographic texture, which could explain differences in the blister shape. Mechanical tests monitored with an infrared camera showed that significant local heating occurred at strain rates higher than 0.1/s. In parallel, the Expansion Due to Compression test was optimized to increase the bi-axiality level from uniaxial stress to plane strain (HB-EDC and VHB-EDC tests). This increase in loading bi-axiality lowers greatly the fracture strain at 25 C and 350 C only in homogeneous material without blister. Eventually, the ductility decrease of unirradiated Zircaloy-4 cladding tube in function of the blister depth was quantified. (author)

  11. 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.

  12. Coiled tubing

    International Nuclear Information System (INIS)

    Oil and gas wells that flow on initial completion eventually reach a condition of liquid loading that kills the wells. This results form declining reservoir pressure, decreased gas volume (velocity), increased water production and other factors that cause liquids to accumulate at the bottom of the well and exert back pressure on the formation. This restricts or in some cases prevents fluid entry into the wellbore form the formation. Flowing production can be restored or increased by reducing surface backpressure, well bore stimulation, pressure maintenance or by installing a string of smaller diameter tubing. This paper reports on installation (hanging off) of a concentric string of coiled tubing inside existing production tubing which is an economically viable, safe, convenient and effective alterative for returning some of these liquid loaded )logged-up) wells to flowing status

  13. Influence of the original structure and aging temperature and time on the formation of sigma-phase in tubes of 12Kh18N12T steel

    International Nuclear Information System (INIS)

    An investigation was made of 32x6 mm steam superheater tubes of 12Kh18N12T steel containing 0.09% C and 0.50% Ti. It was established that the aging temperature, the length of the hold at the selected temperature, and the grain size of the original metal influence the formation of σ-phase. The microhardness of specimens taken from the tubes before and after straightening in relation to the investigated factors is shown. It is shown that an increase in aging temperature and time in combination with a coarse-grained structure of steam superheater tubes of 12Kh18N12T steel leads to precipitation of σ-phase in the grain boundaries, which may cause embrittlement of the tube metal in service of it

  14. Capillary regeneration in scleroderma: stem cell therapy reverses phenotype?

    Directory of Open Access Journals (Sweden)

    Jo N Fleming

    Full Text Available BACKGROUND: Scleroderma is an autoimmune disease with a characteristic vascular pathology. The vasculopathy associated with scleroderma is one of the major contributors to the clinical manifestations of the disease. METHODOLOGY/PRINCIPAL FINDINGS: We used immunohistochemical and mRNA in situ hybridization techniques to characterize this vasculopathy and showed with morphometry that scleroderma has true capillary rarefaction. We compared skin biopsies from 23 scleroderma patients and 24 normal controls and 7 scleroderma patients who had undergone high dose immunosuppressive therapy followed by autologous hematopoietic cell transplant. Along with the loss of capillaries there was a dramatic change in endothelial phenotype in the residual vessels. The molecules defining this phenotype are: vascular endothelial cadherin, a supposedly universal endothelial marker required for tube formation (lost in the scleroderma tissue, antiangiogenic interferon alpha (overexpressed in the scleroderma dermis and RGS5, a signaling molecule whose expression coincides with the end of branching morphogenesis during development and tumor angiogenesis (also overexpressed in scleroderma skin. Following high dose immunosuppressive therapy, patients experienced clinical improvement and 5 of the 7 patients with scleroderma had increased capillary counts. It was also observed in the same 5 patients, that the interferon alpha and vascular endothelial cadherin had returned to normal as other clinical signs in the skin regressed, and in all 7 patients, RGS5 had returned to normal. CONCLUSION/SIGNIFICANCE: These data provide the first objective evidence for loss of vessels in scleroderma and show that this phenomenon is reversible. Coordinate changes in expression of three molecules already implicated in angiogenesis or anti-angiogenesis suggest that control of expression of these three molecules may be the underlying mechanism for at least the vascular component of this disease

  15. Patterns and sources of variation in pollen deposition and pollen tube formation in flowers of the endemic monoecious shrub Cnidoscolus souzae (Euphorbiaceae).

    Science.gov (United States)

    Arceo-Gómez, G; Alonso, C; Abdala-Roberts, L; Parra-Tabla, V

    2016-07-01

    Pollen deposition and pollen tube formation are key components of angiosperm reproduction but intraspecific variation in these has rarely been quantified. Documenting and partitioning (populations, plants and flowers) natural variation in these two aspects of plant reproduction can help uncover spatial mosaics of reproductive success and underlying causes. In this study, we assess variation in pollen deposition and pollen tube formation for the endemic monoecious shrub Cnidoscolus souzae throughout its distribution range in Mexico, and determine how this variation is structured among populations, plants and flowers. We also infer the relative importance of pollen quantity and quality in determining pollination success in this species. While we found no evidence suggesting that pollen receipt limits C. souzae reproduction across 19 populations, we did find extensive variation in pollen load size and pollen tube number per flower. Total variation in pollen receipt and pollen tube number was mostly explained by intra-individual and among-population variance. Furthermore, pollen load size had a stronger effect on the number of pollen tubes at the base of the style than pollen germination rate, suggesting that pollen quantity may be more important than quality for pollen tube success in C. souzae. Our results suggest that both small within-plant flower differences and broad-scale differences in community attributes can play an important role in determining pollination success. We emphasise the need to evaluate patterns and sources of variation in pollen deposition and pollen tube formation as a first step in understanding the causes of variation in pollination success over broad spatial scales. PMID:26916543

  16. Experimental studies of formation and development of corrosion damages of heat exchanging tubes in steam generators at NPP with VVER-1000

    International Nuclear Information System (INIS)

    The report deals with the results of studies of the processes of formation and development of corrosion damages on heat exchanging tubes of steam generators at NPP with WWER-1000, obtained during tests at the simulator model of tube bundles of horizontal steam generator of PGV-1000 type presenting further development of the work with the results partially presented. Tests of the simulator model were performed by several stages when various operating conditions of steam generator were simulated (power operation, shutdown mode, standby mode, the mode of hydrotests for strength). The results of the last stage of the tests are given that were performed with measurements of electrochemical potential of the secondary side environment in the model under the conditions of simulation of the steam generation operation at power and shutdown modes when impurities get into the secondary side that leads to in change in water chemistry parameters. The results on material studies of defects on the model heat exchanging tubes and deposits after the last stage of the tests are given also. By the results of the performed tests and studies the analysis was carried out on the effect of various steam generator operation modes on formation of defects on heat exchanging tubes, and the structural model was specified for calculational evaluations of degradation of heat exchanging tubes in horizontal steam generators. It is demonstrated that defects identified during eddy current test of heat exchanging tubes are formed mainly in the course of standby and transient operation conditions, and formation of defects during power operation of steam generator is possible only with presence of considerable amount of oxidizer in corrosion deposits on the steam generator heat exchanging tubes. (author)

  17. 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.

  18. Novel Mechanisms of Compromised Lymphatic Endothelial Cell Homeostasis in Obesity: The Role of Leptin in Lymphatic Endothelial Cell Tube Formation and Proliferation.

    Directory of Open Access Journals (Sweden)

    Akinori Sato

    Full Text Available Leptin is a hormone produced by adipose tissue that regulates various physiological processes. Recent studies have shown that the level of circulating leptin is elevated in obese patients and have suggested a relationship between obesity and postoperative lymphedema. However, the mechanisms by which postoperative lymphedema develops in obese patients and the mechanisms by which leptin regulates lymphatic endothelial cell homeostasis such as tube formation and cell proliferation remain unknown. Here we report that leptin regulates tube formation and cell proliferation in human dermal lymphatic endothelial cells (HDLECs by activation of the signal transducer and activator of transcription 3 pathway, which is downstream signaling of the leptin receptor. Additionally, we found that upregulation of suppressor of cytokine signaling 3 underlies the mechanisms by which a high dose of leptin inhibits cell proliferation and tube formation. Leptin also enhanced expression of the proinflammatory cytokine IL-6 in HDLECs. Interestingly, IL-6 rescues the compromised cell proliferation and tube formation caused by treatment with a high dose of leptin in an autocrine or paracrine manner. Taken together, our findings reveal a novel mechanism by which compromised HDLECs maintain their homeostasis during inflammation mediated by leptin and IL-6. Thus, regulating the level of leptin or IL-6 may be a viable strategy to reduce the incidence of postoperative lymphedema.

  19. Novel Mechanisms of Compromised Lymphatic Endothelial Cell Homeostasis in Obesity: The Role of Leptin in Lymphatic Endothelial Cell Tube Formation and Proliferation

    Science.gov (United States)

    Kawata, Koji; Kawada, Masaya; Jitsukawa, Sumito; Yamashita, Keiji; Sato, Noriyuki; Himi, Tetsuo; Ichimiya, Shingo

    2016-01-01

    Leptin is a hormone produced by adipose tissue that regulates various physiological processes. Recent studies have shown that the level of circulating leptin is elevated in obese patients and have suggested a relationship between obesity and postoperative lymphedema. However, the mechanisms by which postoperative lymphedema develops in obese patients and the mechanisms by which leptin regulates lymphatic endothelial cell homeostasis such as tube formation and cell proliferation remain unknown. Here we report that leptin regulates tube formation and cell proliferation in human dermal lymphatic endothelial cells (HDLECs) by activation of the signal transducer and activator of transcription 3 pathway, which is downstream signaling of the leptin receptor. Additionally, we found that upregulation of suppressor of cytokine signaling 3 underlies the mechanisms by which a high dose of leptin inhibits cell proliferation and tube formation. Leptin also enhanced expression of the proinflammatory cytokine IL-6 in HDLECs. Interestingly, IL-6 rescues the compromised cell proliferation and tube formation caused by treatment with a high dose of leptin in an autocrine or paracrine manner. Taken together, our findings reveal a novel mechanism by which compromised HDLECs maintain their homeostasis during inflammation mediated by leptin and IL-6. Thus, regulating the level of leptin or IL-6 may be a viable strategy to reduce the incidence of postoperative lymphedema. PMID:27366905

  20. Comprehensive two-dimensional gas chromatography with a multi-capillary second dimension: A new column-set format for simultaneous optimum linear velocity operation

    NARCIS (Netherlands)

    D. Peroni; A.A.S. Sampat; W. van Egmond; S. de Koning; J. Cochran; R. Lautamo; H.-G. Janssen

    2013-01-01

    Comprehensive two-dimensional gas chromatography (GC x GC) suffers from the impossibility to operate both dimensions at their optimum carrier gas velocity at the same time due to the different inner diameters of the columns typically employed. The use of multiple parallel capillary columns in the se

  1. Direct analysis of formate in human plasma, serum and whole blood by in-line coupling of microdialysis to capillary electrophoresis for rapid diagnosis of methanol poisoning

    Czech Academy of Sciences Publication Activity Database

    Kubáň, Pavel; Boček, Petr

    2013-01-01

    Roč. 768, 21 JAN (2013), s. 82-89. ISSN 0003-2670 R&D Projects: GA ČR GAP206/10/1219 Institutional support: RVO:68081715 Keywords : capillary electrophoresis * in-line microdialysis * methanol intoxication Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.517, year: 2013

  2. Diamond synthesis at atmospheric pressure by microwave capillary plasma chemical vapor deposition

    International Nuclear Information System (INIS)

    Polycrystalline diamond has been synthesized on silicon substrates at atmospheric pressure, using a microwave capillary plasma chemical vapor deposition technique. The CH4/Ar plasma was generated inside of quartz capillary tubes using 2.45 GHz microwave excitation without adding H2 into the deposition gas chemistry. Electronically excited species of CN, C2, Ar, N2, CH, Hβ, and Hα were observed in the emission spectra. Raman measurements of deposited material indicate the formation of well-crystallized diamond, as evidenced by the sharp T2g phonon at 1333 cm−1 peak relative to the Raman features of graphitic carbon. Field emission scanning electron microscopy images reveal that, depending on the growth conditions, the carbon microstructures of grown films exhibit “coral” and “cauliflower-like” morphologies or well-facetted diamond crystals with grain sizes ranging from 100 nm to 10 μm

  3. Vascular Endothelial Growth Factor-A (VEGF-A) Mediates Activin A-Induced Human Trophoblast Endothelial-Like Tube Formation.

    Science.gov (United States)

    Li, Yan; Zhu, Hua; Klausen, Christian; Peng, Bo; Leung, Peter C K

    2015-11-01

    Remodeling of maternal spiral arteries during pregnancy requires a subpopulation of extravillous cytotrophoblasts (EVTs) to differentiate into endovascular EVTs. Activin A, which is abundantly expressed at the maternal-fetal interface, has been shown to promote trophoblast invasion, but its role in endovascular differentiation remains unknown. Vascular endothelial growth factor-A (VEGF-A) is well recognized as a key regulator in trophoblast endovascular differentiation. Whether and how activin A might regulate VEGF-A production in human trophoblasts and its relationship to endovascular differentiation have yet to be determined. In the present study, we found that activin A increased VEGF-A production in primary and immortalized (HTR8/SVneo) human EVT cells. In addition, activin A enhanced HTR8/SVneo endothelial-like tube formation, and these effects were attenuated by pretreatment with small interfering RNA targeting VEGF-A or the VEGF receptor 1/2 inhibitor SU4312. Pretreatment with the activin/TGF-β type 1 receptor (ALK4/5/7) inhibitor SB431542 abolished the stimulatory effects of activin A on phosphorylated mothers against decapentaplegic (SMAD)-2/3 phosphorylation, VEGF-A production, and endothelial-like tube formation. Moreover, small interfering RNA-mediated down-regulation of SMAD2, SMAD3, or common SMAD4 abolished the effects of activin A on VEGF-A production and endothelial-like tube formation. In conclusion, activin A may promote human trophoblast cell endothelial-like tube formation by up-regulating VEGF-A production in an SMAD2/3-SMAD4-dependent manner. These findings provide insight into the cellular and molecular events regulated by activin A during human implantation. PMID:26327470

  4. Prokineticin Receptor‐1 Is a New Regulator of Endothelial Insulin Uptake and Capillary Formation to Control Insulin Sensitivity and Cardiovascular and Kidney Functions

    OpenAIRE

    Dormishian, Mojdeh; Turkeri, Gulen; Urayama, Kyoji; Nguyen, Thu Lan; Boulberdaa, Mounia; Messaddeq, Nadia; Renault, Gilles; Henrion, Daniel; Nebigil, Canan G.

    2013-01-01

    Background Reciprocal relationships between endothelial dysfunction and insulin resistance result in a vicious cycle of cardiovascular, renal, and metabolic disorders. The mechanisms underlying these impairments are unclear. The peptide hormones prokineticins exert their angiogenic function via prokineticin receptor‐1 (PKR1). We explored the extent to which endothelial PKR1 contributes to expansion of capillary network and the transcapillary passage of insulin into the heart, kidney, and adip...

  5. In-line coupling of microextractions across polymer inclusion membranes to capillary zone electrophoresis for rapid determination of formate in blood samples

    Czech Academy of Sciences Publication Activity Database

    Pantůčková, Pavla; Kubáň, Pavel; Boček, Petr

    2015-01-01

    Roč. 887, AUG (2015), s. 111-117. ISSN 0003-2670 R&D Projects: GA ČR(CZ) GA13-05762S Grant ostatní: GA AV ČR(CZ) R200311404 Institutional support: RVO:68081715 Keywords : capillary electrophoresis * in-line coupling * polymer inclusion membrane extraction Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.513, year: 2014

  6. 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.

  7. Formação in vitro de túbulos capilares a partir de células de sangue de cordão umbilical humano com perspectivas para aplicação terapêutica In vitro formation of capillary tubules from human umbilical cord blood cells with perspectives for therapeutic application

    Directory of Open Access Journals (Sweden)

    Alexandra Cristina Senegaglia

    2008-12-01

    Full Text Available OBJETIVO: As células progenitoras endoteliais (CPE, caracterizadas pelo marcador CD133+, contribuem para a neovascularização, e o aumento no número dessas células pode ser uma ferramenta terapêutica promissora. O sangue de cordão umbilical humano contém um número significante de CPE, sugerindo a possibilidade do uso destas células para a revascularização de tecidos isquêmicos. O objetivo desse trabalho foi analisar a funcionalidade das células CD133+ diferenciadas in vitro. MÉTODOS: As células diferenciadas foram caracterizadas por citometria de fluxo; a expressão do mRNA de VEGF foi avaliada por RT-PCR e a funcionalidade, por meio de ensaios de formação de túbulos capilares. RESULTADOS: As células diferenciadas perderam os marcadores de CPE, mantiveram em níveis baixos os marcadores das linhagens hematopoética e monocíticas e aumentaram a expressão dos marcadores de células endoteliais adultas. As células diferenciadas apresentaram transcritos no mRNA de VEGF e mostraram-se capazes de formar túbulos capilares in vitro. CONCLUSÃO: As células CD133+ diferenciadas in vitro em células endoteliais demonstraram serem funcionalmente ativas, abrindo perspectiva para seu uso futuro em aplicações terapêuticas.OBJECTIVE: Endothelial progenitor cells (EPC caracterized by the CD133+ marker, contribute to the neovascularization. Increasing EPC number in vitro could be a promising therapeutic tool. Human umbilical cord blood maintains a significant number of EPC, suggesting the possibility to use these cells to induce the revascularization of ischemic tissues. The aim of this study was to analize the in vitro function of differentiated CD133+ cells. METHODS: Cells were characterized by flow cytometry, VEGF mRNA expression was evaluated by the RT-PCR analysis and the functionally by essays of capillary tubes formation. RESULTS: Differentiated cells lost EPC markers, maintained low levels of markers for hematopoietic and

  8. 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

  9. 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.

  10. 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

  11. Zinc-chelation contributes to the anti-angiogenic effect of ellagic acid on inhibiting MMP-2 activity, cell migration and tube formation.

    Directory of Open Access Journals (Sweden)

    Sheng-Teng Huang

    Full Text Available BACKGROUND: Ellagic acid (EA, a dietary polyphenolic compound, has been demonstrated to exert anti-angiogenic effect but the detailed mechanism is not yet fully understood. The aim of this study was to investigate whether the zinc chelating activity of EA contributed to its anti-angiogenic effect. METHODS AND PRINCIPAL FINDINGS: The matrix metalloproteinases-2 (MMP-2 activity, a zinc-required reaction, was directly inhibited by EA as examined by gelatin zymography, which was reversed dose-dependently by adding zinc chloride. In addition, EA was demonstrated to inhibit the secretion of MMP-2 from human umbilical vein endothelial cells (HUVECs as analyzed by Western blot method, which was also reversed by the addition of zinc chloride. Reversion-inducing cysteine-rich protein with Kazal motifs (RECK, known to down-regulate the MMP-2 activity, was induced by EA at both the mRNA and protein levels which was correlated well with the inhibition of MMP-2 activity. Interestingly, zinc chloride could also abolish the increase of EA-induced RECK expression. The anti-angiogenic effect of EA was further confirmed to inhibit matrix-induced tube formation of endothelial cells. The migration of endothelial cells as analyzed by transwell filter assay was suppressed markedly by EA dose-dependently as well. Zinc chloride could reverse these two effects of EA also in a dose-dependent manner. Since magnesium chloride or calcium chloride could not reverse the inhibitory effect of EA, zinc was found to be involved in tube formation and migration of vascular endothelial cells. CONCLUSIONS/SIGNIFICANCE: Together these results demonstrated that the zinc chelation of EA is involved in its anti-angiogenic effects by inhibiting MMP-2 activity, tube formation and cell migration of vascular endothelial cells. The role of zinc was confirmed to be important in the process of angiogenesis.

  12. Apolipoprotein(a) inhibits in vitro tube formation in endothelial cells: identification of roles for Kringle V and the plasminogen activation system.

    Science.gov (United States)

    Liu, Lei; Boffa, Michael B; Koschinsky, Marlys L

    2013-01-01

    Elevated plasma concentrations of lipoprotein(a) are associated with increased risk for atherothrombotic diseases. Apolipoprotein(a), the unique glycoprotein component of lipoprotein(a), is characterized by the presence of multiple kringle domains, and shares a high degree of sequence homology with the serine protease zymogen plasminogen. It has been shown that angiostatin, a proteolytic fragment of plasminogen containing kringles 1-4, can effectively inhibit angiogenesis. Moreover, proteolytic fragments of plasminogen containing kringle 5 are even more potent inhibitors of angiogenesis than angiostatin. Despite its strong similarity with plasminogen, the role of apolipoprotein(a) in angiogenesis remains controversial, with both pro- and anti-angiogenic effects reported. In the current study, we evaluated the ability of apolipoprotein(a) to inhibit VEGF- and angiopoietin-induced tube formation in human umbilical cord endothelial cells. A 17 kringle-containing form of recombinant apo(a) (17K), corresponding to a well-characterized, physiologically-relevant form of the molecule, effectively inhibited tube formation induced by either VEGF or angiopoietin-1. Using additional recombinant apolipoprotein(a) (r-apo(a)) variants, we demonstrated that this effect was dependent on the presence of an intact lysine-binding site in kringle V domain of apo(a), but not on the presence of the functional lysine-binding site in apo(a) kringle IV type 10; sequences within in the amino-terminal half of the molecule were also not required for the inhibitory effects of apo(a). We also showed that the apo(a)-mediated inhibition tube formation could be reversed, in part by the addition of plasmin or urokinase plasminogen activator, or by removal of plasminogen from the system. Further, we demonstrated that apo(a) treated with glycosidases to remove sialic acid was significantly less effective in inhibiting tube formation. This is the first report of a functional role for the glycosylation

  13. Apolipoprotein(a inhibits in vitro tube formation in endothelial cells: identification of roles for Kringle V and the plasminogen activation system.

    Directory of Open Access Journals (Sweden)

    Lei Liu

    Full Text Available Elevated plasma concentrations of lipoprotein(a are associated with increased risk for atherothrombotic diseases. Apolipoprotein(a, the unique glycoprotein component of lipoprotein(a, is characterized by the presence of multiple kringle domains, and shares a high degree of sequence homology with the serine protease zymogen plasminogen. It has been shown that angiostatin, a proteolytic fragment of plasminogen containing kringles 1-4, can effectively inhibit angiogenesis. Moreover, proteolytic fragments of plasminogen containing kringle 5 are even more potent inhibitors of angiogenesis than angiostatin. Despite its strong similarity with plasminogen, the role of apolipoprotein(a in angiogenesis remains controversial, with both pro- and anti-angiogenic effects reported. In the current study, we evaluated the ability of apolipoprotein(a to inhibit VEGF- and angiopoietin-induced tube formation in human umbilical cord endothelial cells. A 17 kringle-containing form of recombinant apo(a (17K, corresponding to a well-characterized, physiologically-relevant form of the molecule, effectively inhibited tube formation induced by either VEGF or angiopoietin-1. Using additional recombinant apolipoprotein(a (r-apo(a variants, we demonstrated that this effect was dependent on the presence of an intact lysine-binding site in kringle V domain of apo(a, but not on the presence of the functional lysine-binding site in apo(a kringle IV type 10; sequences within in the amino-terminal half of the molecule were also not required for the inhibitory effects of apo(a. We also showed that the apo(a-mediated inhibition tube formation could be reversed, in part by the addition of plasmin or urokinase plasminogen activator, or by removal of plasminogen from the system. Further, we demonstrated that apo(a treated with glycosidases to remove sialic acid was significantly less effective in inhibiting tube formation. This is the first report of a functional role for the

  14. Chaos and Formation of Structures in an Electron Flow with a Virtual Cathode in the Bounded Drift Tube

    OpenAIRE

    Hramov, Alexander

    2006-01-01

    The electron beam with a virtual cathode (VC) in the drift tube is investigated with the help of a 1.5-dimensional relativistic electromagnetic code. The existence of complex modes, including chaotic modes,is demonstrated. The dynamic nature of chaos in the considered system is revealed. Physical processes in the flow are investigated, and it is found that the initiation of chaotic dynamics of the electron beam with VC isrelated to the nonlinear interaction of structures formed in the system.

  15. Development of dissimilar welding technique between PNC-FMS wrapper tube and SUS316 steel. 1. Investigation of δ ferrite formation and evaluation of Charpy impact property

    International Nuclear Information System (INIS)

    Ferritic/Martensitic steel (PNC-FMS) with superior resistance to swelling is being developed as wrapper tube for the long-life core of large-scale fast breeder reactor. If the δ ferrite phase would be formed at heat affected zone (HAZ) in welding between PNC-FMS wrapper tube and SUS316 steel, and thus toughness degradation would be suspected due to δ ferrite formation. In this study, the formation of the δ ferrite in applying TIG welding and EB welding are investigated using base metal of 3 types, which are Nieq max./Creq min., Nieq min./Creq max. and the center of chemical composition in the specification. The effect of the amount of the δ ferrite formation and characteristics of toughness change with thermal aging were evaluated. The results are summarized as follows. 1. The δ ferrite generation can be suppressed in the combination of welding process and chemical composition. (1) In case of specification center, the δ ferrite formation can be suppressed about 1% by EB welding. (2) In case of Nieq max./Creq min. in the specification, the δ ferrite formation can be perfectly suppressed even in TIG welding or EB welding. 2. The relationship between δ ferrite content and Charpy impact value was investigated using 3 types of chemical composition in the specification. (1) Ductile Brittle Transition Temperature (DBTT) increased, when δ ferrite content increases. (2) DBTT shift by aging is within about 23degC. (3) DBTT is influenced by grain size and it is lower as the fine grain (grain no.11). (4) Upper Shelf Energy (USE) is not dependent on the δ ferrite content. (author)

  16. 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. 

  17. Effect of crystallographic orientation on the anodic formation of nanoscale pores/tubes in TiO2 films

    International Nuclear Information System (INIS)

    Self-organized nanopores and nanotubes have been produced in thin films of titanium (Ti) prepared using filtered cathodic vacuum arc (FCVA), DC- and RF-sputter deposition systems. The anodization process was performed using a neutral electrolyte containing fluoride ions with an applied potential between 2 and 20 V (for clarity the results are only presented for 5 V). Scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray diffraction (XRD) techniques were used to characterise the films. It was found that the crystallographic orientation of the Ti films played a significant role in determining whether pores or tubes were formed during the anodic etching process.

  18. Endovascular Treatment of Persistent Epistaxis due to Pseudoaneurysm Formation of the Ophthalmic Artery Secondary to Nasogastric Tube

    International Nuclear Information System (INIS)

    We present the case of a 60-year-old man with persistent epistaxis for 20 days that had started 2 weeks after removal of a nasogastric tube placed for an abdominal operation. There was no pathologic finding at selective facial and internal maxillary artery injections. An injury to the ethmoidal branches of the ophthalmic arteries or other arterial origins of bleeding was suspected. The internal carotid artery angiography revealed a pseudoaneurysm of an anterior ethmoidal branch of the left ophthalmic artery. The pseudoaneurysm was occluded with NBCA-histoacryl (25%) injection

  19. Analysis of transient coolant void formation during a guillotine-type HX tube rupture event in the Star-LM system employing a supercritical CO2 Brayton cycle

    International Nuclear Information System (INIS)

    One proposed concept for the STAR-LM Lead Fast Reactor (LFR) incorporates a supercritical CO2 gas turbine Brayton cycle to achieve high cycle efficiency and reduced plant footprint. In this design, 100+% of core full power is transferred by natural circulation from the core, located at the bottom of the reactor vessel, to in-vessel heat exchangers (HXs) located at the top of the vessel in the annulus between the core shroud and vessel inner wall. Although this approach extremely simplifies the plant design, the presence of the HXs within the vessel raises concerns regarding the potential rupture of a HX tube that would initiate a high-pressure blowdown of CO2 into the lead coolant. The principal issue is to what extent, if any, is void entrained downwards with the coolant and then upwards through the core where adverse reactivity effects or degraded heat removal could result. To address this question, a scoping analysis of transient void formation during a guillotine-type HX tube rupture event in the STAR-LM employing a supercritical CO2 Brayton cycle has been performed. The void formation process is evaluated by solving a coupled set of ordinary differential equations describing: i) the supercritical CO2 blowdown, ii) bubble center-of-mass trajectory, iii) bubble growth rate, iv) bubble gas internal energy, and v) discrete bubble formation rate due to Taylor instability at the bubble/coolant interface. The results indicate that for thermal hydraulic conditions consistent with the current STAR-LM design, the peak blowdown rate from a single tube rupture is ∼ 2.5 kg/sec. The void formation process is dominated by large coherent gas bubbles that penetrate minimally downwards into the coolant due to the large coolant density. Rather, the gas pockets are predicted to periodically rise due to buoyancy and vent to the core cover gas region, as opposed to being swept downwards with the coolant. Moreover, the total CO2 fraction that is rendered in the form of discrete

  20. 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

  1. 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.

  2. 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

  3. 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.

  4. Formate supplementation enhances folate-dependent nucleotide biosynthesis and prevents spina bifida in a mouse model of folic acid-resistant neural tube defects.

    Science.gov (United States)

    Sudiwala, Sonia; De Castro, Sandra C P; Leung, Kit-Yi; Brosnan, John T; Brosnan, Margaret E; Mills, Kevin; Copp, Andrew J; Greene, Nicholas D E

    2016-07-01

    The curly tail mouse provides a model for neural tube defects (spina bifida and exencephaly) that are resistant to prevention by folic acid. The major ct gene, responsible for spina bifida, corresponds to a hypomorphic allele of grainyhead-like 3 (Grhl3) but the frequency of NTDs is strongly influenced by modifiers in the genetic background. Moreover, exencephaly in the curly tail strain is not prevented by reinstatement of Grhl3 expression. In the current study we found that expression of Mthfd1L, encoding a key component of mitochondrial folate one-carbon metabolism (FOCM), is significantly reduced in ct/ct embryos compared to a partially congenic wild-type strain. This expression change is not attributable to regulation by Grhl3 or the genetic background at the Mthfd1L locus. Mitochondrial FOCM provides one-carbon units as formate for FOCM reactions in the cytosol. We found that maternal supplementation with formate prevented NTDs in curly tail embryos and also resulted in increased litter size. Analysis of the folate profile of neurulation-stage embryos showed that formate supplementation resulted in an increased proportion of formyl-THF and THF but a reduction in proportion of 5-methyl THF. In contrast, THF decreased and 5-methyl THF was relatively more abundant in the liver of supplemented dams than in controls. In embryos cultured through the period of spinal neurulation, incorporation of labelled thymidine and adenine into genomic DNA was suppressed by supplemental formate, suggesting that de novo folate-dependent biosynthesis of nucleotides (thymidylate and purines) was enhanced. We hypothesise that reduced Mthfd1L expression may contribute to susceptibility to NTDs in the curly tail strain and that formate acts as a one-carbon donor to prevent NTDs. PMID:26924399

  5. Cycle analysis of an alkali metal thermo-electric converter for small capillary type

    International Nuclear Information System (INIS)

    This paper describes the design of a small size Alkali Metal Thermal to Electric Converter (AMTEC) which employs a capillary structure for recirculating sodium working fluid. The cycle is based on the simple and small capillary type β-alumina and wick tube element. The proposed cell consists of the 37 conversion elements with capillary tube of 50μm in diameter and the sealed cylindrical vessel of 22mm in outer diameter. Results on the cycle analysis of sodium flow and heat transfer in the cell showed that the expected power output was 4.65 W and the conversion efficiency was 19% for the source temperature of 900 K

  6. microRNA-210 MODIFIED HUMAN UMBILICAL VEIN ENDOTHELIAL CELLS INDUCE CAPILLARY FORMATION%microRNA-210基因修饰人脐静脉内皮细胞诱导血管形成

    Institute of Scientific and Technical Information of China (English)

    娄远蕾; 高法梁; 谢安; 郭菲; 邓志锋; 汪泱

    2012-01-01

    Objective To construct human recombinant lentiviral expression vector of microRNA-210 (miR-210) and to explore the over-expression of miR-210 on the capillary formation in human umbilical vein endothelial cells 12 (HUVE-12). Methods The recombinant lentiviral expression vector of pGCSIL-green fluorescent protein (GFP)-pre-miR-210 was constructed by molecular cloning and transfected to HUVE-12 (LV-miR-210-GFP group), only pGCSIL-GFP was transfected as control group (LV-GFP group). The miR-210 expression activity was evaluated by GFP reporter through fluorescence detection and real-time fluorescent quantitative PCR. The ephrinA3 protein expression was measured by flow cytometry. The concentration of vascular endothelial growth factor (VEGF) in culture supernatant was determined by ELISA. The cells were cultured in 96-well culture plate coated with Matrigel to assess the ability of capillary formation. Results The recombinant plasmid pGCSIL-GFP-pre-miR-210 was confirmed by restriction endonuclease analysis and DNA sequencing. Fluorescence detection showed that the fluorescence intensity of GFP was highest between 48 and 72 hours after transfection. Real-time fluorescent quantitative PCR showed that the miR-210 expression of LV-miR-210-GFP group was 9.72 times higher than that in LV-GFP group ((t=—11.10, P=0.00). Flow cytometry analysis showed that the positive cell rate of enphrinA3 in LV-miR-210-GFP group (12.52% + 0.67%) was significantly lower than that in LV-GFP group (73.22% ± 1.45%) (t= -66.12, P=0.00). The concentration of VEGF in supernatant in LV-miR-210-GFP group was significantly higher than that in LV-GFP group [(305.29 + 16.52) pg/mL vs. (42.52 ±3.11)pg/mL, (=-27.06, P=0.00]. In vitro capillary-like formation assay showed that the number of capillaries was significantly larger in LV-miR-210-GFP group than in LV-GFP group (17.33 + 6.33 vs. 6.33 ± 2.33, t=-2.83, P=0.04). Conclusion The recombinant lentiviral expression vector of miR-210 is constructed

  7. INVESTIGATION OF FOULING DEPOSIT FORMATION DURING PASTEURIZATION OF CHILI SAUCE BY USING LAB-SCALE CONCENTRIC TUBE-PASTEURIZER

    Directory of Open Access Journals (Sweden)

    NUR ATIKA ALI

    2014-06-01

    Full Text Available This paper investigates the characteristics of fouling deposits obtained from chilli sauce pasteurization. A lab-scale concentric tube-pasteurizer was used to pasteurize the chilli sauce at 0.712 kg/min and 90±5°C. It was operated for 3 hours. Temperature changes were recorded during pasteurization and the data was used to plot the heat transfer profile and the fouling resistance profile. The thickness of the fouling deposit was also measured and the image was taken for every hour. The fouling deposit was collected at every hour to test its stickiness, hardness and flow behaviour. Proximate analysis was also performed and it shows that the fouling deposit from the chilli sauce is categorized as carbohydrate-based fouling deposits. Activation energy of chilli sauce is 7049.4 J.mole-1 which shows a greater effect of temperature on the viscosity. The hardness, stickiness of fouling deposit and the heat resistance increases as the chilli sauce continuously flows inside the heat exchanger.

  8. 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

  9. Intermediate Scale Laboratory Testing to Understand Mechanisms of Capillary and Dissolution Trapping during Injection and Post-Injection of CO2 in Heterogeneous Geological Formations

    Energy Technology Data Exchange (ETDEWEB)

    Illangasekare, Tissa [Colorado School of Mines, Golden, CO (United States); Trevisan, Luca [Colorado School of Mines, Golden, CO (United States); Agartan, Elif [Colorado School of Mines, Golden, CO (United States); Mori, Hiroko [Colorado School of Mines, Golden, CO (United States); Vargas-Johnson, Javier [Colorado School of Mines, Golden, CO (United States); Gonzalez-Nicolas, Ana [Colorado School of Mines, Golden, CO (United States); Cihan, Abdullah [Colorado School of Mines, Golden, CO (United States); Birkholzer, Jens [Colorado School of Mines, Golden, CO (United States); Zhou, Quanlin [Colorado School of Mines, Golden, CO (United States)

    2015-03-31

    Carbon Capture and Storage (CCS) represents a technology aimed to reduce atmospheric loading of CO2 from power plants and heavy industries by injecting it into deep geological formations, such as saline aquifers. A number of trapping mechanisms contribute to effective and secure storage of the injected CO2 in supercritical fluid phase (scCO2) in the formation over the long term. The primary trapping mechanisms are structural, residual, dissolution and mineralization. Knowledge gaps exist on how the heterogeneity of the formation manifested at all scales from the pore to the site scales affects trapping and parameterization of contributing mechanisms in models. An experimental and modeling study was conducted to fill these knowledge gaps. Experimental investigation of fundamental processes and mechanisms in field settings is not possible as it is not feasible to fully characterize the geologic heterogeneity at all relevant scales and gathering data on migration, trapping and dissolution of scCO2. Laboratory experiments using scCO2 under ambient conditions are also not feasible as it is technically challenging and cost prohibitive to develop large, two- or three-dimensional test systems with controlled high pressures to keep the scCO2 as a liquid. Hence, an innovative approach that used surrogate fluids in place of scCO2 and formation brine in multi-scale, synthetic aquifers test systems ranging in scales from centimeter to meter scale developed used. New modeling algorithms were developed to capture the processes controlled by the formation heterogeneity, and they were tested using the data from the laboratory test systems. The results and findings are expected to contribute toward better conceptual models, future improvements to DOE numerical codes, more accurate assessment of storage capacities, and optimized placement strategies. This report presents the experimental and modeling methods

  10. Phase Formation and Superconductivity of Fe-TUBE Encapsulated and Vacuum-Annealed MgB2

    Science.gov (United States)

    Singh, K. P.; Awana, V. P. S.; Shahabuddin, Md.; Husain, M.; Saxena, R. B.; Nigam, Rashmi; Ansari, M. A.; Gupta, Anurag; Narayan, Himanshu; Halder, S. K.; Kishan, H.

    We report optimization of the synthesis parameters viz. heating temperature (TH), and hold time (thold) for vacuum-annealed (10-5 Torr) and LN2 (liquid nitrogen) quenched MgB2 compound. These are single-phase compounds crystallizing in the hexagonal structure (space group P6/mmm) at room temperature. Our XRD results indicated that for phase-pure MgB2, the TH for 10-5 Torr annealed and LN2-quenched samples is 750°C. The right stoichiometry i.e., MgB2 of the compound corresponding to 10-5 Torr and TH of 750°C is found for the hold time (thold) of 2.30 hours. With varying thold from 1-4 hours at fixed TH (750°C) and vacuum (10-5 Torr), the c-lattice parameter decreases first and later increases with thold (hours) before a near saturation, while the a-lattice parameter first increases and later decreases beyond a thold of 2.30 hours. The c/a ratio versus thold plot showed an inverted bell-shaped curve, touching the lowest value of 1.141, which is the reported value for perfect stoichiometry of MgB2. The optimized stoichimetric MgB2 compound exhibited superconductivity at 39.2 K with a transition width of 0.6 K. In conclusion, the synthesis parameters for phase pure stoichimetric vacuum-annealed MgB2 compound are optimized and are compared with widely-reported Ta tube encapsulated samples.

  11. 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

  12. 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.

  13. 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.

  14. Capillary Flows along Open Channel Conduits: the Open-Star Section

    Science.gov (United States)

    Weislogel, Mark; Chen, Yongkang; Nguyen, Thanh; Geile, John; Callahan, Michael

    2014-11-01

    Capillary rise in tubes, channels, and grooves has received significant attention in the literature for over 100 years. In yet another incremental extension of related work, a transient capillary rise problem is solved for spontaneous flow along an interconnected array of open channels forming what is referred to as an ``open-star'' section. This geometry possesses several attractive characteristics including passive phase separations and high diffusive gas transport rates. Despite the complex geometry, novel and convenient approximations for capillary pressure and viscous resistance enable closed form predictions of the flow. As part of the solution, a combined scaling approach is applied that identifies unsteady-inertial-capillary, convective-inertial-capillary, and visco-capillary transient regimes in a single parameter. Drop tower experiments are performed employing 3-D printed conduits to corroborate all findings. NASA NNX09AP66A, Glenn Research Center.

  15. An integrated multiple capillary array electrophoresis system for high-throughput DNA sequencing

    Energy Technology Data Exchange (ETDEWEB)

    Lu, X.

    1998-03-27

    A capillary array electrophoresis system was chosen to perform DNA sequencing because of several advantages such as rapid heat dissipation, multiplexing capabilities, gel matrix filling simplicity, and the mature nature of the associated manufacturing technologies. There are two major concerns for the multiple capillary systems. One concern is inter-capillary cross-talk, and the other concern is excitation and detection efficiency. Cross-talk is eliminated through proper optical coupling, good focusing and immersing capillary array into index matching fluid. A side-entry excitation scheme with orthogonal detection was established for large capillary array. Two 100 capillary array formats were used for DNA sequencing. One format is cylindrical capillary with 150 {micro}m o.d., 75 {micro}m i.d and the other format is square capillary with 300 {micro}m out edge and 75 {micro}m inner edge. This project is focused on the development of excitation and detection of DNA as well as performing DNA sequencing. The DNA injection schemes are discussed for the cases of single and bundled capillaries. An individual sampling device was designed. The base-calling was performed for a capillary from the capillary array with the accuracy of 98%.

  16. 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)

  17. 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)

  18. Elevated AKR1C3 expression promotes prostate cancer cell survival and prostate cell-mediated endothelial cell tube formation: implications for prostate cancer progressioan

    International Nuclear Information System (INIS)

    Aldo-keto reductase (AKR) 1C family member 3 (AKR1C3), one of four identified human AKR1C enzymes, catalyzes steroid, prostaglandin, and xenobiotic metabolism. In the prostate, AKR1C3 is up-regulated in localized and advanced prostate adenocarcinoma, and is associated with prostate cancer (PCa) aggressiveness. Here we propose a novel pathological function of AKR1C3 in tumor angiogenesis and its potential role in promoting PCa progression. To recapitulate elevated AKR1C3 expression in cancerous prostate, the human PCa PC-3 cell line was stably transfected with an AKR1C3 expression construct to establish PC3-AKR1C3 transfectants. Microarray and bioinformatics analysis were performed to identify AKR1C3-mediated pathways of activation and their potential biological consequences in PC-3 cells. Western blot analysis, reverse transcription-polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA), and an in vitro Matrigel angiogenesis assays were applied to validate the pro-angiogenic activity of PC3-AKR1C3 transfectants identified by bioinformatics analysis. Microarray and bioinformatics analysis suggested that overexpression of AKR1C3 in PC-3 cells modulates estrogen and androgen metabolism, activates insulin-like growth factor (IGF)-1 and Akt signaling pathways, as well as promotes tumor angiogenesis and aggressiveness. Levels of IGF-1 receptor (IGF-1R) and Akt activation as well as vascular endothelial growth factor (VEGF) expression and secretion were significantly elevated in PC3-AKR1C3 transfectants in comparison to PC3-mock transfectants. PC3-AKR1C3 transfectants also promoted endothelial cell (EC) tube formation on Matrigel as compared to the AKR1C3-negative parental PC-3 cells and PC3-mock transfectants. Pre-treatment of PC3-AKR1C3 transfectants with a selective IGF-1R kinase inhibitor (AG1024) or a non-selective phosphoinositide 3-kinases (PI3K) inhibitor (LY294002) abolished ability of the cells to promote EC tube formation. Bioinformatics

  19. 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.

  20. 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

  1. 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

  2. Silencing heme oxygenase-1 gene expression in retinal pigment epithelial cells inhibits proliferation, migration and tube formation of cocultured endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wenjie [Ophthalmology Hospital, The First Affiliated Hospital of Harbin Medical University, 23 Youzheng Street, Harbin 150001 (China); Zhang, Xiaomei, E-mail: zhangxm667@163.com [Ophthalmology Hospital, The First Affiliated Hospital of Harbin Medical University, 23 Youzheng Street, Harbin 150001 (China); Lu, Hong [Ophthalmology Hospital, The First Affiliated Hospital of Harbin Medical University, 23 Youzheng Street, Harbin 150001 (China); Matsukura, Makoto [Laboratory of Clinical Pharmacology and Therapeutics, Faculty of Pharmaceutical Sciences, Sojo University, 4-22-1 Ikeda, Kumamoto 860-0082 (Japan); Zhao, Jien; Shinohara, Makoto [Ashikita Institution for Developmental Disabilities, 2813 Oaza Ashikita, Ashikita-machi, Ashikita, Kumamoto 869-5461 (Japan)

    2013-05-10

    Highlights: •HO-1 is highly induced in RPE cells by hypoxia. •Inhibition of HO-1 activity and knockdown of HO-1 expression inhibit VEGF expression in RPE cells under hypoxia. •Knockdown of HO-1 in RPE cells inhibits angiogenesis of endothelial cells in vitro. -- Abstract: Heme oxygenase-1 (HO-1) plays an important role in the vasculature and in the angiogenesis of tumors, wounds and other environments. Retinal pigment epithelial (RPE) cells and choroidal endothelial cells (CECs) are the main cells involved in choroidal neovascularization (CNV), a process in which hypoxia plays an important role. Our aim was to evaluate the role of human RPE-cell HO-1 in the angiogenic activities of cocultured endothelial cells under hypoxia. Small interfering RNA (siRNA) for HO-1 was transfected into human RPE cell line ARPE-19, and zinc protoporphyrin (ZnPP) was used to inhibit HO-1 activity. Knockdown of HO-1 expression and inhibition of HO-1 activity resulted in potent reduction of the expression of vascular endothelial growth factor (VEGF) under hypoxia. Furthermore, knockdown of HO-1 suppressed the proliferation, migration and tube formation of cocultured endothelial cells. These findings indicated that HO-1 might have an angiogenic effect in CNV through modulation of VEGF expression and might be a potential target for treating CNV.

  3. Silencing heme oxygenase-1 gene expression in retinal pigment epithelial cells inhibits proliferation, migration and tube formation of cocultured endothelial cells

    International Nuclear Information System (INIS)

    Highlights: •HO-1 is highly induced in RPE cells by hypoxia. •Inhibition of HO-1 activity and knockdown of HO-1 expression inhibit VEGF expression in RPE cells under hypoxia. •Knockdown of HO-1 in RPE cells inhibits angiogenesis of endothelial cells in vitro. -- Abstract: Heme oxygenase-1 (HO-1) plays an important role in the vasculature and in the angiogenesis of tumors, wounds and other environments. Retinal pigment epithelial (RPE) cells and choroidal endothelial cells (CECs) are the main cells involved in choroidal neovascularization (CNV), a process in which hypoxia plays an important role. Our aim was to evaluate the role of human RPE-cell HO-1 in the angiogenic activities of cocultured endothelial cells under hypoxia. Small interfering RNA (siRNA) for HO-1 was transfected into human RPE cell line ARPE-19, and zinc protoporphyrin (ZnPP) was used to inhibit HO-1 activity. Knockdown of HO-1 expression and inhibition of HO-1 activity resulted in potent reduction of the expression of vascular endothelial growth factor (VEGF) under hypoxia. Furthermore, knockdown of HO-1 suppressed the proliferation, migration and tube formation of cocultured endothelial cells. These findings indicated that HO-1 might have an angiogenic effect in CNV through modulation of VEGF expression and might be a potential target for treating CNV

  4. Polymer multilayers loaded with antifungal β-peptides kill planktonic Candida albicans and reduce formation of fungal biofilms on the surfaces of flexible catheter tubes.

    Science.gov (United States)

    Raman, Namrata; Lee, Myung-Ryul; Palecek, Sean P; Lynn, David M

    2014-10-10

    Candida albicans is the most common fungal pathogen responsible for hospital-acquired infections. Most C. albicans infections are associated with the implantation of medical devices that act as points of entry for the pathogen and as substrates for the growth of fungal biofilms that are notoriously difficult to eliminate by systemic administration of conventional antifungal agents. In this study, we report a fill-and-purge approach to the layer-by-layer fabrication of biocompatible, nanoscale 'polyelectrolyte multilayers' (PEMs) on the luminal surfaces of flexible catheters, and an investigation of this platform for the localized, intraluminal release of a cationic β-peptide-based antifungal agent. We demonstrate that polyethylene catheter tubes with luminal surfaces coated with multilayers ~700nm thick fabricated from poly-l-glutamic acid (PGA) and poly-l-lysine (PLL) can be loaded, post-fabrication, by infusion with β-peptide, and that this approach promotes extended intraluminal release of this agent (over ~4months) when incubated in physiological media. The β-peptide remained potent against intraluminal inoculation of the catheters with C. albicans and substantially reduced the formation of C. albicans biofilms on the inner surfaces of film-coated catheters. Finally, we report that these β-peptide-loaded coatings exhibit antifungal activity under conditions that simulate intermittent catheter use and microbial challenge for at least three weeks. We conclude that β-peptide-loaded PEMs offer a novel and promising approach to kill C. albicans and prevent fungal biofilm formation on surfaces, with the potential to substantially reduce the incidence of device-associated infections in indwelling catheters. β-Peptides comprise a promising new class of antifungal agents that could help address problems associated with the use of conventional antifungal agents. The versatility of the layer-by-layer approach used here thus suggests additional opportunities to

  5. On-column radioisotope detection for capillary electrophoresis

    International Nuclear Information System (INIS)

    Three on-line radioactivity detection schemes for capillary electrophoresis are described. The first detector system utilizes a commercially available semiconductor device positioned external to the separation channel and responding directly to impinging γ or high-energy β radiation. The second detector system utilizes a commercially available plastic scintillator material and a cooled photomultiplier tube operated in the photon counting mode. The third detector system utilizes a plastic scintillator material and two room-temperature photomultiplier tubes operated in the coincidence counting mode. The system performance and detector efficiency are evaluated for each of the detection schemes using synthetic mixtures of 32P-labeled sample molecules. The detection limits are determined to be in the low nanocurie range for separations performed under standard conditions (an injected sample quantity of 1 nanocurie corresponds to 110 x 10-18 moles of 32P). The lower limit of detection is extended to the sub-nanocurie level by using flow (voltage) programming to increase the residence time of labeled sample components in the detection volume. The separation of 32P-labeled oligonucleotide mixtures using polyacrylamide gel-filled capillaries and on-line radioisotope detection is also presented. When desired, the residence time can be made almost arbitrarily long by freezing the contents of the capillary, permitting autoradiograms to be recorded. This last technique is applied to gel-filled capillaries and provides a detection sensitivity of a few DPM per separated component, corresponding to subattomole amounts of radiolabel

  6. Diamond synthesis at atmospheric pressure by microwave capillary plasma chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Hemawan, Kadek W.; Gou, Huiyang; Hemley, Russell J. [Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Rd., NW, Washington, DC 20015 (United States)

    2015-11-02

    Polycrystalline diamond has been synthesized on silicon substrates at atmospheric pressure, using a microwave capillary plasma chemical vapor deposition technique. The CH{sub 4}/Ar plasma was generated inside of quartz capillary tubes using 2.45 GHz microwave excitation without adding H{sub 2} into the deposition gas chemistry. Electronically excited species of CN, C{sub 2}, Ar, N{sub 2}, CH, H{sub β}, and H{sub α} were observed in the emission spectra. Raman measurements of deposited material indicate the formation of well-crystallized diamond, as evidenced by the sharp T{sub 2g} phonon at 1333 cm{sup −1} peak relative to the Raman features of graphitic carbon. Field emission scanning electron microscopy images reveal that, depending on the growth conditions, the carbon microstructures of grown films exhibit “coral” and “cauliflower-like” morphologies or well-facetted diamond crystals with grain sizes ranging from 100 nm to 10 μm.

  7. Asymptotic Behaviour of Capillary Problems governed by Disjoining Pressure Potentials

    OpenAIRE

    Thomys, Oliver

    2010-01-01

    Introduction Capillarity describes the effects caused by the surface tension on liquids. When considering small amounts ofliquid,thesurfacetension becomes the dominating parameter. In this situation the arising mathematical task is to determine the occurring capillary surface. At the beginning of the research on this topic, problems such as the ascent of fluids in a circular tube, on a vertical wall or on a wedge were some of the first problems scientists were concerned with. At the beginning...

  8. A new in vivo capillary assay of coagulation in invertebrates

    Directory of Open Access Journals (Sweden)

    C Bajzek

    2012-10-01

    Full Text Available Greater understanding of insect clotting requires better tests that can be performed in whole, living insects. We found we could collect hemolymph bleeding from wounded Drosophila larvae in microcapillary tubes. The capillary assay showed a difference in the amount of bleeding between feeding and wandering stage third instar larvae, and performed well with clotting mutations. This new in vivo coagulation assay will be helpful for studies of coagulation in Drosophila and other invertebrates.

  9. Gas Dynamical Capillary Flowmeters of Small and Micro Flowrates of Gases

    OpenAIRE

    Stasiuk, Ivan

    2015-01-01

    The possibility of application of glass capillary tubes (CTs) as sensors of small and micro flowrates of gases was justified. The accuracy of a number of CTs flowrate equations was analyzed on the basis of experimental studies of CTs flowrate characteristics. It was shown that CTs can be applied as primary devices of small and micro flowrates of gases without individual calibration. The results of studies on the dynamic properties of gas dynamical capillary flowmeters of small and micro flowr...

  10. 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...

  11. 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

  12. A submicron synchrotron X-ray beam generated by capillary optics

    International Nuclear Information System (INIS)

    A novel capillary optics technique for focusing synchrotron X-ray beams has been applied in an experiment performed at the DORIS storage ring at HASYLAB. This new technqiue, which utilizes the total reflection properties of X-rays inside small capillaries, has recently been applied to generate microbeams of X-rays, with a beam size down to about 10 μm using conventional X-ray tubes. The result from our recent experiment shows that capillary optics can also be used to generate a submicron beam of X-rays from a synchrotron light source. A description of the capillary unit, and the alignment procedure is given. The influence of the thermal load on the device caused by the intense flux of synchrotron radiation will be discussed. Future perspectives of the capillary techniques as applied to synchrotron radiation will be discussed. (orig.)

  13. 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

  14. Mecanismos de Separação em Eletroforese Capilar Separation Mechanisms in Capillary Electrophoresis

    OpenAIRE

    Tavares, Marina F. M.

    1997-01-01

    Since its inception in the 80's, capillary electrophoresis has matured into a well established technique for the separation and analysis of complex samples. One of its strongest aspects is the ability to handle materials from a diversity of chemical classes, ranging from few to millions of Daltons. This is only possible because several modes of electrophoresis can be performed in a single capillary format. In this work, relevant aspects of capillary zone electrophoresis in its three modes (fr...

  15. Gastrostomy Tube (G-Tube)

    Science.gov (United States)

    ... endoscope (a thin, flexible tube with a tiny camera and light at the tip) inserted through the ... Nemours Foundation, iStock, Getty Images, Corbis, Veer, Science Photo Library, Science Source Images, Shutterstock, and Clipart.com

  16. Ear tube insertion

    Science.gov (United States)

    Myringotomy; Tympanostomy; Ear tube surgery; Pressure equalization tubes; Ventilating tubes; Ear infection - tubes; Otitis - tubes ... trapped fluid can flow out of the middle ear. This prevents hearing loss and reduces the risk ...

  17. 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.

  18. 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.

  19. 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

  20. Tube morphogenesis: closure, but many openings remain

    OpenAIRE

    Nelson, W. James

    2003-01-01

    Epithelial and endothelial tubes form the basic structure of many organs and tissues in the fruit fly Drosophila melanogaster, the nematode Caenorhabditis elegans, zebrafish and mammals. Comparison of how tubes form during development defines several pathways that generate a single unbranched tube or dichotomously branching tubular networks. The formation of tubes can be induced directly by intrinsic signals within epithelial primordia or by inductive signaling between adjacent epithelia and ...

  1. An alternative method to amplify RNA without loss of signal conservation for expression analysis with a proteinase DNA microarray in the ArrayTube® format

    Directory of Open Access Journals (Sweden)

    Wiederanders B

    2006-06-01

    Full Text Available Abstract Background Recent developments in DNA microarray technology led to a variety of open and closed devices and systems including high and low density microarrays for high-throughput screening applications as well as microarrays of lower density for specific diagnostic purposes. Beside predefined microarrays for specific applications manufacturers offer the production of custom-designed microarrays adapted to customers' wishes. Array based assays demand complex procedures including several steps for sample preparation (RNA extraction, amplification and sample labelling, hybridization and detection, thus leading to a high variability between several approaches and resulting in the necessity of extensive standardization and normalization procedures. Results In the present work a custom designed human proteinase DNA microarray of lower density in ArrayTube® format was established. This highly economic open platform only requires standard laboratory equipment and allows the study of the molecular regulation of cell behaviour by proteinases. We established a procedure for sample preparation and hybridization and verified the array based gene expression profile by quantitative real-time PCR (QRT-PCR. Moreover, we compared the results with the well established Affymetrix microarray. By application of standard labelling procedures with e.g. Klenow fragment exo-, single primer amplification (SPA or In Vitro Transcription (IVT we noticed a loss of signal conservation for some genes. To overcome this problem we developed a protocol in accordance with the SPA protocol, in which we included target specific primers designed individually for each spotted oligomer. Here we present a complete array based assay in which only the specific transcripts of interest are amplified in parallel and in a linear manner. The array represents a proof of principle which can be adapted to other species as well. Conclusion As the designed protocol for amplifying m

  2. 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

  3. 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

  4. Ear Tubes

    Science.gov (United States)

    ... of the ear drum or eustachian tube, Down Syndrome, cleft palate, and barotrauma (injury to the middle ear caused by a reduction of air pressure, ... specialist) may be warranted if you or your child has experienced repeated ... fluid in the middle ear, barotrauma, or have an anatomic abnormality that ...

  5. Dynamics of miscible displacements in round tubes

    Energy Technology Data Exchange (ETDEWEB)

    Meiburg, E.; Maxworthy, T.; Chen, C.Y. [Univ. of Southern California, Los Angeles, CA (United States); Petitjeans, P. [Ecole Superieure de Physique et de Chimie Industrielles, Paris (France)

    1995-12-31

    A combined experimental and numerical investigation of miscible two-phase flow in a capillary tube is reported. The fraction of fluid left behind on the wall is obtained as a function of the Peclet, Atwood, and Froude numbers. Scaling arguments are presented for two distinct flow regimes, dominated by diffusion and convection, respectively. In the latter one, an effective surface tension value can be estimated.

  6. 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

  7. The YouTube reader

    OpenAIRE

    2009-01-01

    YouTube has come to epitomize the possibilities of digital culture. With more than seventy million unique users a month and approximately eighty million videos online, this brand-name video distribution platform holds the richest repository of popular culture on the Internet. As the fastest growing site in the history of the Web, YouTube promises endless new opportunities for amateur video, political campaigning, entertainment formats, and viral marketing—a clip culture that has seemed to out...

  8. Electron tube

    Energy Technology Data Exchange (ETDEWEB)

    Suyama, Motohiro (Hamamatsu, JP); Fukasawa, Atsuhito (Hamamatsu, JP); Arisaka, Katsushi (Los Angeles, CA); Wang, Hanguo (North Hills, CA)

    2011-12-20

    An electron tube of the present invention includes: a vacuum vessel including a face plate portion made of synthetic silica and having a surface on which a photoelectric surface is provided, a stem portion arranged facing the photoelectric surface and made of synthetic silica, and a side tube portion having one end connected to the face plate portion and the other end connected to the stem portion and made of synthetic silica; a projection portion arranged in the vacuum vessel, extending from the stem portion toward the photoelectric surface, and made of synthetic silica; and an electron detector arranged on the projection portion, for detecting electrons from the photoelectric surface, and made of silicon.

  9. Neutron tubes

    Science.gov (United States)

    Leung, Ka-Ngo; Lou, Tak Pui; Reijonen, Jani

    2008-03-11

    A neutron tube or generator is based on a RF driven plasma ion source having a quartz or other chamber surrounded by an external RF antenna. A deuterium or mixed deuterium/tritium (or even just a tritium) plasma is generated in the chamber and D or D/T (or T) ions are extracted from the plasma. A neutron generating target is positioned so that the ion beam is incident thereon and loads the target. Incident ions cause D-D or D-T (or T-T) reactions which generate neutrons. Various embodiments differ primarily in size of the chamber and position and shape of the neutron generating target. Some neutron generators are small enough for implantation in the body. The target may be at the end of a catheter-like drift tube. The target may have a tapered or conical surface to increase target surface area.

  10. Straightening tubes

    International Nuclear Information System (INIS)

    Hexagonal wrapper tubes, especially for nuclear reactor core sub-assemblies, may suffer from unacceptable bow as a result of welding wear pads to the wrapper and heat treatment. Straightening of the bow is effected by a method wherein at each of a series of axially spaced locations the faces or vertices of the tube are measured relative to a reference to determine the direction of bow at the locations. From these measurements, the appropriate axial locations for the application of corrective loading can be determined, whereby by application of the loading at a selected face or vertex for such measurements the bow is reduced. Such loading, by an actuator, can be repeated at the locations until the bow is reduced to within tolerances. (author)

  11. 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)

  12. 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...

  13. 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.

  14. Polyimide polymer glass-free capillary columns for gas chromatography.

    Science.gov (United States)

    Webster, Jackie G; Marine, Susan S; Danielson, Neil D

    2011-01-01

    Polymeric polyimide capillary tubing, both uncoated and coated with stationary phases of two polarities, is explored for use as capillary columns for gas chromatography (GC). These glass-free polyimide columns are flexible and their small winding diameter of less than a cm around a solid support makes them compatible for potential use in portable GC instruments. Polyimide columns with dimensions of 0.32 mm i.d. × 3 m are cleaned, annealed at 300°C, and coated using the static method with phenylmethylsilicone (PMS). Separations of volatile organics are investigated isothermally on duplicate sets of polyimide columns by GC with a flame ionization detector using split injection. Unlike the uncoated ones, the coated polyimide columns successfully separate Grob test mix classes of alkanes, amines, and fatty acid methyl esters. The relative standard deviations for retention time and peak area are 0.5 and 2.5 , respectively. With the 3 m PMS-coated column connected to a retention gap to permit operation at its optimum flow rate of 30 cm/s, a plate count of 3200 or plate height of 1 mm is possible. Lack of retention and tailing peaks are evident for the polyimide polymer capillary columns as compared to that of a 3 m commercial cross-linked PMS fused silica capillary. However, headspace analyses of an aromatic hydrocarbon mix and a Clearcoat automotive paint sample are viable applications on the PMS polyimide polymer column. PMID:21682994

  15. Effects of Angelica Oil on Germ Tube Formation and Adhesion of Candida albicans%当归油对白色念珠菌芽管形成及黏附性的影响

    Institute of Scientific and Technical Information of China (English)

    苑天红; 罗喜荣; 佘晓玲; 贺娟; 杨军

    2012-01-01

    目的:研究当归油对白色念珠菌芽管形成及其黏附人口腔上皮细胞的影响.方法:将100、50、10mg/L当归油分别与白色念珠菌悬液、白色念珠菌与人口腔上皮细胞混合液共同孵育,显微镜下计数芽管形成率、白色念珠菌对人口腔上皮细胞的黏附百分率,分别设立阳性对照组和阴性对照组,重复5次试验.结果:当归油各剂量组白色念珠菌芽管生成率及对口腔上皮细胞黏附率低于阴性对照组(P<0.05),100mg/L当归油组白色念珠菌芽管生成率及对口腔上皮细胞黏附率低于50mg/L、10mg/L当归油组(P<0.05),与阳性对照组无统计学差异(P>0.05).结论:当归油对体外白色念珠菌的芽管形成及黏附性有较强抑制作用.%Objective; To investigate the effects of angelica oil on Candida albicans germ tube forma-tion and adhesion of Candida albicans to human oral epithelial cells. Methods: Candida albicans sus-pension and mixed suspension of Candida albicans with human oral epithelial cells were incubated with various concentrations of angelica oil (100, 50, 10 mg/L) respectively. The rates of germ tube forma-tion and Candida albicans adhering to human oral epithelial cells were counted under microscope. Re-sults : All concentrations of angelica oil inhibited Candida albicans germ tube formation and adhesion of Candida albicans to oral epithelial cells. Conclusions; Angelica oil could inhibit Candida albicans germ tube formation and adhesion of Candida albicans to oral epithelial cells.

  16. 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)

  17. 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

  18. Fiber pigtailed thin wall capillary coupler for excitation of microsphere WGM resonator.

    Science.gov (United States)

    Wang, Hanzheng; Lan, Xinwei; Huang, Jie; Yuan, Lei; Kim, Cheol-Woon; Xiao, Hai

    2013-07-01

    In this paper, we demonstrate a fiber pigtailed thin wall capillary coupler for excitation of Whispering Gallery Modes (WGMs) of microsphere resonators. The coupler is made by fusion-splicing an optical fiber with a capillary tube and consequently etching the capillary wall to a thickness of a few microns. Light is coupled through the peripheral contact between inserted microsphere and the etched capillary wall. The coupling efficiency as a function of the wall thickness was studied experimentally. WGM resonance with a Q-factor of 1.14 × 10(4) was observed using a borosilicate glass microsphere with a diameter of 71 μm. The coupler operates in the reflection mode and provides a robust mechanical support to the microsphere resonator. It is expected that the new coupler may find broad applications in sensors, optical filters and lasers. PMID:23842369

  19. Capillary flow of oil in a single foam microchannel

    CERN Document Server

    Piroird, Keyvan

    2013-01-01

    Under specific physico-chemical conditions, oil droplets are able to invade the liquid network of a foam without damaging it. We study experimentally the capillary suction of oil in a single foam channel, a Plateau border. Oil flows as an unbroken stream with a dynamics that differs from classical wicking in a capillary tube due to the deformability of the foam channel. The oil forms a long and stable liquid slug inside the Plateau border, which does not break into droplets as long as the oil is confined within the Plateau Border. Yet, destabilization occurs when oil is transferred from the Plateau border to a soap film, after the break-up of a soap film as may happen in real foams.

  20. photomultiplier tubes

    CERN Multimedia

    photomultiplier tubes. A device to convert light into an electric signal (the name is often abbreviated to PM). Photomultipliers are used in all detectors based on scintillating material (i.e. based on large numbers of fibres which produce scintillation light at the passage of a charged particle). A photomultiplier consists of 3 main parts: firstly, a photocathode where photons are converted into electrons by the photoelectric effect; secondly, a multiplier chain consisting of a serie of dynodes which multiply the number of electron; finally, an anode, which collects the resulting current.

  1. photomultiplier tube

    CERN Multimedia

    photomultiplier tubes. A device to convert light into an electric signal (the name is often abbreviated to PM). Photomultipliers are used in all detectors based on scintillating material (i.e. based on large numbers of fibres which produce scintillation light at the passage of a charged particle). A photomultiplier consists of 3 main parts: firstly, a photocathode where photons are converted into electrons by the photoelectric effect; secondly, a multiplier chain consisting of a serie of dynodes which multiply the number of electron; finally, an anode, which collects the resulting current.

  2. Experimental results for an experimental condensation heat exchanger with a spiral minichanel tube. Comparison to numerical imulations

    Directory of Open Access Journals (Sweden)

    Hrubý J.

    2013-04-01

    Full Text Available The paper describes new results for an experimental heat exchanger equipped with a single corrugated capillary tube, basic information about the measurements and the experimental setup. Some of the results were compared with numerical simulations.

  3. Examining the anti-candidal activity of 10 selected Indian herbs and investigating the effect of Lawsonia inermis extract on germ tube formation, protease, phospholipase, and aspartate dehydrogenase enzyme activity in Candida albicans

    Science.gov (United States)

    Ravichandran, Sripathy; Muthuraman, Sundararaman

    2016-01-01

    Objective: The objective of the study is to identify potential anti-candidal agents from natural resources and elucidate the effect of Lawsonia inermis extract on major virulent factors of Candida albicans. Materials and Methods: Plants, the most abundant and readily available resource of diverse bioactives, were chosen for the anti-candidal screening study. Ten different plants that were proven to have antimicrobial activity but not explored much for anti-candidal activity were chosen for this study. Ethyl acetate extract of these plant leaves were tested for the anti-candidal activity. Extracts with good anti-candidal activity were further screened for its effect in C. albicans germ tube formation and enzyme (protease, phospholipase, and aspartate dehydrogenase) activity. Results: Among 10 plants screened, L. inermis extract showed complete inhibition of C. albicans. On further evaluation, this extract completely inhibited C. albicans germ tube formation in serum until the end of incubation period (3 h). This extract also exhibited dose-dependent inhibitory activity against two major virulent enzymes of C. albicans, proteases (27–33%) and phospholipases (44.5%). In addition to it, this extract completely inhibited both the isoforms of constitutive candidal enzyme aspartate dehydrogenase, thereby affecting amino acid biosynthesis. Conclusion: Thus, this study confirms the anti-candidal potential of L. inermis and hence can be considered further for development of anti-candidal drug. PMID:26997722

  4. Surfactant influence on rivulet droplet flow in minitubes and capillaries and its downstream evolution.

    Science.gov (United States)

    Labib, Mohamed E; Dukhin, Stanislav; Murawski, Joseph; Tabani, Yacoob; Lai, Richard

    2011-08-10

    During our investigations of two-phase flow in long hydrophobic minitubes and capillaries, we have observed transformation of the main rivulet into different new hydrodynamic modes with the use of different kinds of surfactants. The destabilization of rivulet flow at air velocities liquid film. The surfactant influence on the behavior of the rivulets in minitubes is incomparably stronger than the classic example of the known surfactant stabilizing influence on a free jet. The evolution of a rivulet in the downstream flow inside a long minitube includes the following sequence of hydrodynamic modes/patterns: i) single rivulet; ii) rivulet and sub-rivulets; and iii) rivulet, sub-rivulets, sub-rivulet fragments, cornered droplets, linear droplet arrays, linear arrays of sub-rivulet fragments and annular film. The formation of these many different hydrodynamic patterns downstream is in drastic contrast with the known characteristics of two-phase flow, which demonstrates one mode for the entire tube length. Recent achievements in fluid mechanics regarding the stability of sliding thin films and in wetting dynamics have allowed us to interpret many of our findings. However, the most important phenomenon of the surfactant influence on sub-rivulet formation remains poorly understood. To achieve further progress in this new area, an interdisciplinary approach based on the use of methods of two-phase flow, wetting dynamics and interfacial rheology will be necessary. PMID:21652020

  5. 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

  6. 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.

  7. Template-assisted formation of microsized nanocrystalline CeO2 tubes and their catalytic performance in the carboxylation of methanol

    Directory of Open Access Journals (Sweden)

    Jörg J. Schneider

    2011-11-01

    Full Text Available Polymethylmethacrylate (PMMA/ceria composite fibres were synthesized by using a sequential combination of polymer electrospinning, spray-coating with a sol, and a final calcination step to yield microstructured ceria tubes, which are composed of nanocrystalline ceria particles. The PMMA template is removed from the organic/inorganic hybrid material by radio frequency (rf plasma etching followed by calcination of the ceramic green-body fibres. Microsized ceria (CeO2 tubes, with a diameter of ca. 0.75 µm, composed of nanocrystalline agglomerated ceria particles were thus obtained. The 1-D ceramic ceria material was characterized by X-ray diffraction, scanning electron microscopy (SEM, high-resolution transmission electron microscopy (HRTEM, UV–vis and photoluminescence spectroscopy (PL, as well as thermogravimetric analysis (TGA. Its catalytic performance was studied in the direct carboxylation of methanol with carbon dioxide leading to dimethyl carbonate [(CH3O2CO, DMC], which is widely employed as a phosgene and dimethyl sulfate substitute, and as well as a fuel additive.

  8. Effects of stoichiometric variation and cooling rate on the phase formation and critical current density of Bi-2223 powder-in-tube tapes made from aerosol precursor

    International Nuclear Information System (INIS)

    Powder-in-tube Bi-2223 is currently the most promising high-temperature superconductor that can be fabricated in long lengths by industrial processes, and is likely to be used as the conductor component in first-generation applications. Intensive investigations of these conductors have revealed that the critical current density of fully processed tapes is influenced by a large number of processing parameters. Among these are the thermomechanical processing schedule and the extent of Bi-2223 phase conversion. These parameters are, in turn, affected by the precursor stoichiometry. In this study, powder precursors with varying Cu content were prepared using an aerosol pyrolysis technique, and powder-in-tube conductors were fabricated using these precursors. Both fast and slow cooling rates were employed during thermomechanical processing, and different treatment schedules are correlated to the critical current density. The results indicate that the effect of excess Cu on Jc is minor compared to the large Jc enhancements obtained by employing one or more slow-cooling steps in the thermomechanical processing schedule. (author)

  9. The impact of capillary dilation on the distribution of red blood cells in artificial networks.

    Science.gov (United States)

    Schmid, Franca; Reichold, Johannes; Weber, Bruno; Jenny, Patrick

    2015-04-01

    Recent studies suggest that pericytes around capillaries are contractile and able to alter the diameter of capillaries. To investigate the effects of capillary dilation on network dynamics, we performed simulations in artificial capillary networks of different sizes and complexities. The unequal partition of hematocrit at diverging bifurcations was modeled by assuming that each red blood cell (RBC) enters the branch with the faster instantaneous flow. Network simulations with and without RBCs were performed to investigate the effect of local dilations. The results showed that the increase in flow rate due to capillary dilation was less when the effects of RBCs are included. For bifurcations with sufficient RBCs in the parent vessel and nearly equal flows in the branches, the flow rate in the dilated branch did not increase. Instead, a self-regulation of flow was observed due to accumulation of RBCs in the dilated capillary. A parametric study was performed to examine the dependence on initial capillary diameter, dilation factor, and tube hematocrit. Furthermore, the conditions needed for an efficient self-regulation mechanism are discussed. The results support the hypothesis that RBCs play a significant role for the fluid dynamics in capillary networks and that it is crucial to consider the blood flow rate and the distribution of RBCs to understand the supply of oxygen in the vasculature. Furthermore, our results suggest that capillary dilation/constriction offers the potential of being an efficient mechanism to alter the distribution of RBCs locally and hence could be important for the local regulation of oxygen delivery. PMID:25617356

  10. Places to Go: YouTube

    Science.gov (United States)

    Downes, Stephen

    2008-01-01

    Founded in 2005 by three former PayPal employees, YouTube has revolutionized the Internet, marking a change from the static Internet to the dynamic Internet. In this edition of Places to Go, Stephen Downes discusses how the rise of a ubiquitous media format--Flash video--has made YouTube's success possible and argues that Flash video has important…

  11. 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...

  12. 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...

  13. 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...

  14. Tracheostomy tube - eating

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000464.htm Tracheostomy tube - eating To use the sharing features on ... when you swallow foods or liquids. Eating and Tracheostomy Tubes When you get your tracheostomy tube, or ...

  15. 管内固相微萃取-气相色谱法在线联用技术用于水样中的痕量分析%On-Line Coupling of In-Tube Solid Phase Microextraction to Capillary Gas Chromatography for Trace Analysis of Aqueous Samples

    Institute of Scientific and Technical Information of China (English)

    关亚风; 王涵文; 刘文民

    2004-01-01

    Since the development of solid phase microextraction ( SPME ) method, many modifications have been made to improve the availability and application of the technique The in-tube SPME (ITSPME) was emerged and employed in high performance liquid chromatography (HPLC)

  16. 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.

  17. Titanium condenser tubes

    International Nuclear Information System (INIS)

    The corrosion resistance of titanium in sea water is extremely excellent, but titanium tubes are expensive, and the copper alloy tubes resistant in polluted sea water were developed, therefore they were not used practically. In 1970, ammonia attack was found on the copper alloy tubes in the air-cooled portion of condensers, and titanium tubes have been used as the countermeasure. As the result of the use, the galvanic attack an copper alloy tube plates with titanium tubes as cathode and the hydrogen absorption at titanium tube ends owing to excess electrolytic protection were observed, but the corrosion resistance of titanium tubes was perfect. These problems can be controlled by the application of proper electrolytic protection. The condensers with all titanium tubes adopted recently in USA are intended to realize perfectly no-leak condensers as the countermeasure to the corrosion in steam generators of PWR plants. Regarding large condensers of nowadays, three problems are pointed out, namely the vibration of condenser tubes, the method of joining tubes and tube plates, and the tubes of no coolant leak. These three problems in case of titanium tubes were studied, and the problem of the fouling of tubes was also examined. The intervals of supporting plates for titanium tubes should be narrowed. The joining of titanium tubes and titanium tube plates by welding is feasible and promising. The cleaning with sponge balls is effective to control fouling. (Kako, I.)

  18. 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.

  19. A capillary-based probe for in situ detection of enhanced fluorescence signals

    International Nuclear Information System (INIS)

    A simple, compact, and high sensitivity capillary-based probe for the in situ detection of fluorescence signals with high sensitivity is demonstrated. A home-made single–multi-mode fiber coupler that is coaxially aligned with the capillary-based probe provides for the transmission of excitation light and the collection and transmission of fluorescence. We propose a conceptually straightforward theoretical model to optimize the factors affecting the fluorescence-capture capability of the capillary-based probe. The fluorescence signal detected by fiber-optic spectroscopy non-linearly increases with the length of the capillary-based probe. In addition, the thicker the capillary tube wall is, the less the fluorescence signals determined are. The performance of the proposed probe is evaluated experimentally by measuring the fluorescence spectra of Cy5.5 dye and blue-green algae. The experimental results show that the proposed probe provides more than a ten-fold increase in fluorescence signal compared with direct measurements by a flat-tipped multi-mode fiber probe. The advantages of the capillary-based probe, which include its simple and compact structure, excellent light collection efficiency, requirement of small sample volume, and recoverability of samples, allow its wide application to in situ detection in the medical, forensic, biological, geological, and environmental fields with high sensitivity. (letter)

  20. The effect of capillary pressure for concave liquid-vapor interface on interfacial evaporation

    Institute of Scientific and Technical Information of China (English)

    张金涛; 王补宣; 彭晓峰

    2001-01-01

    The analysis in this paper demonstrates that the capillary pressure on the concave liquid-vapor interface will promote the interfacial evaporation, therefore clarifying the confusion over the great difference between the estimated and real rate of interfacial evaporation. This difference increases with decreasing capillary radius, and becomes more apparent for liquid with high latent heat. The present analysis also shows that the capillary pressure on the concave interface will result in a decrease in liquid phase equilibrium temperature, which can explain the possibility of vapor bubble formation on micro liquid layer interfacial evaporation under low superheat, or even below the nominal saturated temperature.

  1. The number of capillary bridges in a wet granular medium

    OpenAIRE

    Geromichalos, Dimitrios; Kohonen, Mika M.; Scheel, Mario; Herminghaus, Stephan

    2003-01-01

    We observed the appearance of capillary bridges in a granular medium consisting of glass beads after adding small amounts of liquid. We found the initial bridge formation depending on the bead roughness. Furthermore we obtained a statistics for the average number of bridges for randomly packed beads in dependence of the liquid content and were able to find an explanation therefore based on recent models and former experimental data.

  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. Modeling of low-capillary number segmented flows in microchannels using OpenFOAM

    OpenAIRE

    Hoang, D.A.; Van Steijn V.; Portela, L.M.; Kreutzer, M.T.; Kleijn, C. R.

    2012-01-01

    Modeling of low-Capillary number segmented flows in microchannels is important for the design of microfluidic devices. We present numerical validations of microfluidic flow simulations using the volume-of-fluid (VOF) method as implemented in OpenFOAM. Two benchmark cases were investigated to ensure the reliability of OpenFOAM in modeling complex physical phenomena in microfluidics, viz. 1) the steady motion of bubbles in capillaries, and 2) the formation of bubbles in T-junctions. We found th...

  4. 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...

  5. 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....

  6. 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 ...

  7. 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.

  8. Self-Assembled Colloidal Crystals in Capillary with Its Fiber Junction

    International Nuclear Information System (INIS)

    Silica microspheres self-assembled in glass capillary are investigated. Monodisperse silica microsphere dispersions in diameter 320 nm are self-organized into a bulk cylindrical colloidal crystal by evaporation induced nucleation and crystallization. The resulting colloidal crystals are characterized by optical microscopy and scanning electronic microscopy (SEM), and the SEM images show these crystals dominate in fcc lattice with its (111) crystallographic axis as longitudinal. The colloidal crystal filled capillary is packaged into a heat-shrink plastic tube and a fiber measurement system is designed to measure the optical property of colloidal bulk in capillary. It is found that an appreciable bandgap appears at wavelength 686 nm from the transmission spectroscopy, which is consistent with the theoretical estimation. A considerable photonic band gap of up to –10 dB and a steep photonic band edge of up to 0.25 dB/nm indicate that silica microspheres are promising for implementing optical filter applications in fiber systems

  9. 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.

  10. 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

  11. Physics of magnetic flux tubes

    CERN Document Server

    Ryutova, Margarita

    2015-01-01

    This book is the first account of the physics of magnetic flux tubes from their fundamental properties to collective phenomena in an ensembles of flux tubes. The physics of magnetic flux tubes is absolutely vital for understanding fundamental physical processes in the solar atmosphere shaped and governed by magnetic fields. High-resolution and high cadence observations from recent space and  ground-based instruments taken simultaneously at different heights and temperatures not only show the ubiquity of filamentary structure formation but also allow to study how various events are interconnected by system of magnetic flux tubes. The book covers both theory and observations. Theoretical models presented in analytical and phenomenological forms are tailored for practical applications. These are welded with state-of-the-art observations from early decisive ones to the most recent data that open a new phase-space for exploring the Sun and sun-like stars. Concept of magnetic flux tubes is central to various magn...

  12. Light-induced heat and mass transfer in a single-component gas in a capillary

    International Nuclear Information System (INIS)

    A theoretical analysis is presented of light-induced heat and mass transfer in a single-component gas in a capillary tube at arbitrary Knudsen numbers. Surface and collisional mechanisms of transfer are analyzed, due to differences in accommodation coefficient and collision cross section between excited-and ground-state particles, respectively. Analytical expressions for kinetic coefficients characterizing the gas drift and heat transfer in a capillary tube are obtained in the limits of low and high Knudsen numbers. Numerical computations are performed for intermediate Knudsen numbers. Both drift and heat fluxes are determined as functions of the light beam frequency. In the case of an inhomogeneously broadened absorption line, the light-induced fluxes are found to depend not only on the sign, but also on the amount, of light beam detuning from the absorption line center frequency

  13. 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)

  14. The physics of blood flow in capillaries. I. The nature of the motion.

    Science.gov (United States)

    PROTHERO, J; BURTON, A C

    1961-09-01

    In many capillaries erythrocytes travel singly, separated by segments of plasma (bolus flow). The peculiar flow pattern, within the plasma, has been studied visually in a model in which air bubbles separated by short columns of liquid flow through a glass tube. Injection of dye reveals an "eddy-like" motion, in that each fluid element repeatedly describes a closed circuit. The possible significance of this "mixing motion" in relation to gaseous equilibration (e.g., in pulmonary capillaries) has been studied in a thermal analogue. A copper tube passed first through a constant temperature bath which brought the fluid to a uniform temperature T(1), and then through a second smaller bath at a lower temperature T(2). From the final temperature T(3) of the fluid, which was collected in a thermally insulated flask, a calculation of the heat transfer was made (i.e., from the flow and the temperature drop (T(1)-T(3))). Bolus flow was up to twice as effective in transferring heat as Poiseuille flow (no bubbles in fluid). The theory of modelling was employed in order to apply this thermal data to gaseous equilibration, especially in pulmonary capillaries. It was concluded that gaseous equilibration may be considerably accelerated by bolus flow, though this may be more of a limiting factor in peripheral capillaries than in the pulmonary circulation. The result supports the assumption of complete mixing in plasma made by Roughton and Forster in 1957. PMID:14488985

  15. X-ray tests of microfocusing mono-capillary optic for protein crystallography

    CERN Document Server

    Bilderback, D H

    2001-01-01

    A single, borosilicate-glass capillary was drawn into a 30.5 cm long elliptical shape. The inside diameter was 0.40 mm at the large base end and 0.13 mm at the tip. With 12 keV X-rays from the CHESS D1 bending magnet, the single-bounce capillary produced a focus of better than 18 mu m in diameter (FHWM) at a 3 cm distance from the capillary tip. A flux gain of 110 in the focus position was observed along with a total flux in the spot of 4x10 sup 1 sup 0 X-rays/s (conditions: 5.3 GeV, 182 mA, 1.5% bandwidth multilayer, 12 keV X-rays). A measurement of the far field focus ring diameter yielded a divergence of 3.8 mrad, in good agreement with the 4 mrad design of the optic for protein crystallography. Using a small 25 mu m square beam, we measured the local reflectivity to be greater than 95% and the inner slope errors of the capillary to average about +-150 mu rad, both from raw and elliptically shaped tubing. Our conclusion is that more perfect starting tubing (i.e. one with lower slope errors) is needed to ma...

  16. 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

    The idea of reducing the Earth's greenhouse effect by sequestration of CO2 into the Earth's crust has been discussed and evaluated for more than two decades. Deep saline aquifers are the primary candidate formations for realization of this idea. Evaluation of reservoir capacity and the risk of CO2 leakage require a detailed modeling of the migration and distribution of CO2 in the subsurface structure. There is a finite risk that structural (or hydrodynamic) trapping by caprock may be compromised (e.g. by improperly abandoned wells, stratigraphic discontinuities, faults, etc.). Therefore, other trapping mechanisms (capillary trapping, dissolution, and mineralization) must be considered. Capillary trapping may be very important in providing a "secondary-seal", and is the focus of our investigation. The physical mechanism of CO2 trapping in porous media by capillary trapping incorporates three related processes, i.e. residual trapping, trapping due to hysteresis of the relative permeability, and trapping due to hysteresis of the capillary pressure. Additionally CO2 may be trapped in heterogeneous media due to difference in capillary pressure entry points for different materials. The amount of CO2 trapped by these processes is a complicated nonlinear function of the spatial distribution of permeability, permeability anisotropy, capillary pressure, relative permeability of brine and CO2, permeability hysteresis and residual gas saturation (as well as the rate, total amount and placement of injected CO2). Geological heterogeneities essentially affect the dynamics of a CO2 plume in subsurface environments. Recent studies have led to new conceptual and quantitative models for sedimentary architecture in fluvial deposits over a range of scales that are relevant to the performance of some deep saline reservoirs [1, 2]. We investigated how the dynamics of a CO2 plume, during and after injection, is influenced by the hierarchical and multi-scale stratal architecture in such

  17. 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

  18. Consideration of Sludge Formation in HFC-134a / Polyol Ester oil Refrigeration System

    Science.gov (United States)

    Yamamoto, Tsutomu; Yamamoto, Tethuya; Simizu, Yasuhiko; Nakayama, Yoshinori; Takizawa, Kikuo

    A refrigeration test employing HFC-134a and polyol ester oil was carried out in order to make clear the causes of the sludge formation in the capillary tube. Compressors used were two types: a hermetic reciprocating compressor and a rotary compressor. Installed dryer contained desiccant of the compound zeolite type. The results showed that the amount of capillary sludge increased as the compressor temperature rose. The capillary sludge was determined to consist of desiccant and metal dust for the reciprocating compressor, and of tar-like substance for the rotary compressor. Thermal stability test which was used to check the degree of deterioration of the ester oil, suggested that the presence of desiccant and high compressor temperature might produce tar-like substance by the break down and polymerization of the ester oil. In addition, it was confirmed that factors affecting the sludge formation were the dirtiness of the refrigeration circuit for the reciprocating compressor, and the presence of desiccant, for the rotary compressor.

  19. 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.

  20. 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...

  1. 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...

  2. High Throughput Sample Preparation and Analysis for DNA Sequencing, PCR and Combinatorial Screening of Catalysis Based on Capillary Array Technique

    Energy Technology Data Exchange (ETDEWEB)

    Yonghua Zhang

    2002-05-27

    Sample preparation has been one of the major bottlenecks for many high throughput analyses. The purpose of this research was to develop new sample preparation and integration approach for DNA sequencing, PCR based DNA analysis and combinatorial screening of homogeneous catalysis based on multiplexed capillary electrophoresis with laser induced fluorescence or imaging UV absorption detection. The author first introduced a method to integrate the front-end tasks to DNA capillary-array sequencers. protocols for directly sequencing the plasmids from a single bacterial colony in fused-silica capillaries were developed. After the colony was picked, lysis was accomplished in situ in the plastic sample tube using either a thermocycler or heating block. Upon heating, the plasmids were released while chromsomal DNA and membrane proteins were denatured and precipitated to the bottom of the tube. After adding enzyme and Sanger reagents, the resulting solution was aspirated into the reaction capillaries by a syringe pump, and cycle sequencing was initiated. No deleterious effect upon the reaction efficiency, the on-line purification system, or the capillary electrophoresis separation was observed, even though the crude lysate was used as the template. Multiplexed on-line DNA sequencing data from 8 parallel channels allowed base calling up to 620 bp with an accuracy of 98%. The entire system can be automatically regenerated for repeated operation. For PCR based DNA analysis, they demonstrated that capillary electrophoresis with UV detection can be used for DNA analysis starting from clinical sample without purification. After PCR reaction using cheek cell, blood or HIV-1 gag DNA, the reaction mixtures was injected into the capillary either on-line or off-line by base stacking. The protocol was also applied to capillary array electrophoresis. The use of cheaper detection, and the elimination of purification of DNA sample before or after PCR reaction, will make this approach an

  3. An accessible micro-capillary electrophoresis device using surface-tension-driven flow

    OpenAIRE

    Mohanty, Swomitra K; Warrick, Jay; Gorski, Jack; Beebe, David J.

    2009-01-01

    We present a rapidly fabricated micro-capillary electrophoresis chip that utilizes surface-tension-driven flow for sample injection and extraction of DNA. Surface-tension-driven flow (i.e. passive pumping) injects a fixed volume of sample that can be predicted mathematically. Passive pumping eliminates the need for tubing, valves, syringe pumps, and other equipment typically needed for interfacing with microelectrophoresis chips. This method requires a standard micropipette to load samples be...

  4. 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

  5. Multi-target PCR analysis by capillary electrophoresis and laser-induced fluorescence

    Science.gov (United States)

    Lu, Wei; Han, Dai-Shu; Yuan, Ju; Andrieu, Jean-Marie

    1994-03-01

    Quantitative analysis of polymerase chain reaction (PCR) amplified HIV-1 DNA or cDNA fragments is attained using an automated system that combines capillary-gel electrophoresis (CGE) for high-efficiency separation and laser-induced fluorescence (LIF) for high-sensitivity detection. This system enables the detection of PCR-amplified multiple target DNA or cDNA in the same tube by a single injection with high precision.

  6. 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...

  7. Capillary smectization and layering in a confined liquid crystal.

    Science.gov (United States)

    de Las Heras, D; Velasco, E; Mederos, L

    2005-01-14

    Using density-functional theory, we have analyzed the phase behavior of a model liquid crystal confined between two parallel, planar surfaces (i.e., the so-called slit pore). As a result of confinement, a rich phase behavior arises. The complete liquid-crystal phase diagram of the confined fluid is mapped out as a function of wall separation and chemical potential. Strong commensuration effects in the film with respect to wall separation lead to enhanced smectic ordering, which gives capillary smectization (i.e., formation of a smectic phase in the pore), or frustrated smectic ordering, which suppresses capillary smectization. These effects also produce layering transitions. Our nonlocal density-functional-based analysis provides a unified picture of all the above phenomena. PMID:15698132

  8. Separation of Trivalent Actinides from Lanthanides Using a Capillary Electrophoresis

    International Nuclear Information System (INIS)

    A separation of 241Am(III) from 152,154Eu(III) was carried out using a capillary electrophoresis technique in a mixed solvent (CH3OH/H2O) system containing thiocyanate ion. First, the formation constants (βn) between thiocyanate ion and Eu(III) or Am(III) were investigated in the mixed solvent solutions by a back-extraction technique using bis (2-ethylhexyl) hydrogen phosphate-toluene. The mean charges calculated on the basis of the data of βn for Eu(III) were comparatively higher than those for Am(III). Based on the differences between the mean charges of Eu(III) and Am(III), separations for Am(III)/Eu(III) by means of capillary electrophoresis technique were tried in the (H+, Na+)(SCN-, ClO4-) mixed solvent solutions. It was proved that Am(III) was completely separated from Eu(III). (authors)

  9. Single particles accelerate final stages of capillary break up

    CERN Document Server

    Lindner, Anke; Wagner, Christian

    2015-01-01

    Droplet formation of suspensions is present in many industrial and technological processes such as coating and food engineering. Whilst the finite time singularity of the minimum neck diameter in capillary break-up of simple liquids can be described by well known self-similarity solutions, the pinching of non-Brownian suspension depends in a complex way on the particle dynamics in the thinning thread. Here we focus on the very dilute regime where the filament contains only isolated beads to identify the physical mechanisms leading to the pronounced acceleration of the filament thinning observed. This accelerated regime is characterized by an asymmetric shape of the filament with an enhanced curvature that depends on the size and the spatial distribution of the particles within the capillary thread.

  10. Effective directional self-gathering of drops on spine of cactus with splayed capillary arrays

    Science.gov (United States)

    Liu, Chengcheng; Xue, Yan; Chen, Yuan; Zheng, Yongmei

    2015-12-01

    We report that the fast droplet transport without additional energy expenditure can be achieved on the spine of cactus (Gymnocalycium baldianum) with the assistance of its special surface structure: the cactus spine exhibits a cone-like structure covered with tilted scales. A single scale and the spine surface under it cooperatively construct a splayed capillary tube. The arrays of capillary tube formed by the overlapping scales build up the out layer of the spine. The serial drops would be driven by the asymmetric structure resulted from tilt-up scales-by-scales on the cone-shaped spine, and move directionally toward the bottom from top of spine, by means of the Laplace pressure in differences. In addition, after the past of the first droplet, thin liquid film of drop is trapped in the splayed capillary micro-tube on the surface of spine, which greatly reduces the friction of subsequential droplet transport in efficiency. This finding provides a new biological model which could be used to transport droplet spontaneously and directionally. Also this work offers a way to reduce the surface adhesion by constructing liquid film on the surface, which has great significance in prompting droplet transport efficiency.

  11. Effects of wetting and anchoring on capillary phenomena in a confined liquid crystal.

    Science.gov (United States)

    De Las Heras, D; Velasco, E; Mederos, L

    2004-03-01

    A fluid of hard spherocylinders of length-to-breadth ratio L/D=5 confined between two identical planar, parallel walls--forming a pore of slit geometry--has been studied using a version of the Onsager density-functional theory. The walls impose an exclusion boundary condition over the particle's centers of mass, while at the same time favoring a particular anchoring at the walls, either parallel or perpendicular to the substrate. We observe the occurrence of a capillary transition, i.e., a phase transition associated with the formation of a nematic film inside the pore at a chemical potential different from micro(b)-the chemical potential at the bulk isotropic-nematic transition. This transition terminates at an Ising-type surface critical point. In line with previous studies based on the macroscopic Kelvin equation and the mesoscopic Landau-de Gennes approach, our microscopic model indicates that the capillary transition is greatly affected by the wetting and anchoring properties of the semi-infinite system, i.e., when the fluid is in contact with a single wall or, equivalently, the walls are at a very large distance. Specifically, in a situation where the walls are preferentially wetted by the nematic phase in the semi-infinite system, one has the standard scenario with the capillary transition taking place at chemical potentials less than micro(b) (capillary nematization transition or capillary ordering transition). By contrast, if the walls tend to orientationally disorder the fluid, the capillary transition may occur at chemical potentials larger than micro(b), in what may be called a capillary isotropization transition or capillary disordering transition. Moreover, the anchoring transition that occurs in the semi-infinite system may affect very decisively the confinement properties of the liquid crystal and the capillary transitions may become considerably more complicated. PMID:15267357

  12. The dynamics of the annular liquid layer inside a cylindrical capillary

    Science.gov (United States)

    Zhang, Hua; Nikolov, Alex; Feng, Jianyuan; Wasan, Darsh

    2016-02-01

    When one fluid displaces another in a cylindrical capillary, a layer of the original fluid is often left behind on the capillary wall. We studied the dynamics of a cylindrical hexadecane layer deposited inside glass capillaries after the oil/air displacement experimentally and by a theoretical model prediction. Our experiments have shown that an annular oil layer is formed on the capillary wall after hexadecane is displaced by air. The oil layer subject to surface perturbation becomes unstable over time (Rayleigh instability), forming uniform, regularly spaced double concave meniscuses across the capillary that are bridged with dimples (collars). With time, the film between the meniscus and the dimple thins, but does not break, during the thinning process. The dynamics of the oil layer and the formation of the double concave meniscus with the dimple are more pronounced in a large capillary compared to those phenomena found in a small capillary. In order to reveal the phenomena of the film thinning and stability between the double concave meniscus and the dimple, we monitored an air bubble approaching a flat glass surface in hexadecane. We found that the oil film thinning in a cylindrical glass capillary and on a flat glass substrate was similar; the film did not break during the thinning process. The analysis also showed that the macroscopic contact angle (based on the Laplace solution-extrapolation to a solid substrate) was different from the microscopic contact angle (between the film and meniscus). We adapted the model proposed by Gauglitz and Radke ["An extended evolution equation for liquid film breakup in cylindrical capillaries," Chem. Eng. Sci. 43, 1457 (1988)] for our system (oil-air displacement) and solved it numerically. The numerical result shows a stable film between the liquid bridge and the dimple, which is consistent with our experimental observations. We also estimated the meniscus-film-dimple thickness profile and found it was in fair agreement

  13. 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.

  14. 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)

  15. 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

  16. 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.

  17. Streptavidin-functionalized capillary immune microreactor for highly efficient chemiluminescent immunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Yang Zhanjun [State Key Laboratory of Analytical Chemistry for Life Science, Department of Chemistry, Nanjing University, Nanjing 210093 (China); College of Chemistry and Engineering, Yangzhou University, 88 South University Avenue, Yangzhou 225002 (China); Zong Chen [State Key Laboratory of Analytical Chemistry for Life Science, Department of Chemistry, Nanjing University, Nanjing 210093 (China); Ju Huangxian, E-mail: hxju@nju.edu.cn [State Key Laboratory of Analytical Chemistry for Life Science, Department of Chemistry, Nanjing University, Nanjing 210093 (China); Yan Feng, E-mail: yanfeng2007@sohu.com [Jiangsu Institute of Cancer Prevention and Cure, Nanjing 210009 (China)

    2011-11-07

    Highlights: {yields} A novel capillary immune microreactor was proposed for highly efficient flow-through chemiluminescent immunoassay. {yields} The microreactor was prepared by functionalizing capillary inner wall with streptavidin for capture of biotinylated antibody. {yields} The proposed immunoassay method showed wide dynamic range, good reproducibility, stability and practicality. {yields} The microreactor was low-cost and disposable, and possessed several advantages over the conventional immunoreactors. - Abstract: A streptavidin functionalized capillary immune microreactor was designed for highly efficient flow-through chemiluminescent (CL) immunoassay. The functionalized capillary could be used as both a support for highly efficient immobilization of antibody and a flow cell for flow-through immunoassay. The functionalized inner wall and the capture process were characterized using scanning electron microscopy. Compared to conventional packed tube or thin-layer cell immunoreactor, the proposed microreactor showed remarkable properties such as lower cost, simpler fabrication, better practicality and wider dynamic range for fast CL immunoassay with good reproducibility and stability. Using {alpha}-fetoprotein as model analyte, the highly efficient CL flow-through immunoassay system showed a linear range of 3 orders of magnitude from 0.5 to 200 ng mL{sup -1} and a low detection limit of 0.1 ng mL{sup -1}. The capillary immune microreactor could make up the shortcoming of conventional CL immunoreactors and provided a promising alternative for highly efficient flow-injection immunoassay.

  18. The reopening of a collapsed fluid-filled elastic tube

    Science.gov (United States)

    Juel, Anne; Heap, Alexandra

    We present an experimental study of the reopening mechanics of a collapsed liquid-filled elastic tube. The experiment is a simple mechanical model of pulmonary airway reopening and aims to assess the robustness of existing theoretical models. A metre-long horizontal elastic tube of inner radius R_i {=} 4.88 ± 0.14mm is filled with silicone oil and is carefully collapsed mechanically. The injection of nitrogen at a constant flow rate results in the steady propagation of an air finger, after the decay of initial transients. This behaviour is observed over the realizable range of the capillary numbers Ca, which measures the ratio of viscous and capillary forces. With increasing Ca, the transition region between the collapsed and reopened sections of the tube shortens, and the height of the tube behind the bubble tip increases. We also find that air fingers can propagate in partially reopened tubes, in which the transmural pressure is negative far behind the finger tip.

  19. Coke from small-diameter tubes analyzed

    International Nuclear Information System (INIS)

    The mechanism for coke deposit formation and the nature of the coke itself can vary with the design of the ethylene furnace tube bank. In this article, coke deposits from furnaces with small-diameter pyrolysis tubes are examined. The samples were taken from four furnaces of identical design (Plant B). As in both the first and second installments of the series, the coke deposits were examined using a scanning electron microscope (SEM) and an energy dispersive X-ray analyzer (EDAX). The deposits from the small-diameter tubes are compared with the coke deposits from the furnace discussed in earlier articles. Analysis of the coke in both sets of samples are then used to offer recommendations for improved decoking procedures, operating procedures, better feed selection, and better selection of the metallurgy used in furnace tubes, to extend the operating time of the furnace tubes by reducing the amount and type of coke build up

  20. Neural Tube Defects

    Science.gov (United States)

    Neural tube defects are birth defects of the brain, spine, or spinal cord. They happen in the first month ... that she is pregnant. The two most common neural tube defects are spina bifida and anencephaly. In spina bifida, ...

  1. Tracheostomy tube - speaking

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000465.htm Tracheostomy tube - speaking To use the sharing features on ... are even speaking devices that can help you. Tracheostomy Tubes and Speaking Air passing through vocal cords ( ...

  2. Gastrostomy feeding tube - bolus

    Science.gov (United States)

    ... a gastrostomy tube. Delmar’s Fundamental and Advanced Nursing Skills . 2nd Ed. Albany, NY: Delmar Thomson Learning; 2003: 742-749. Simmons, Remmington R.The percutaneous endoscopic gastrostomy tube: a nurse's guide to PEG tubes. Medsurg Nurs . 2013 Mar- ...

  3. KER-2 tube history

    Energy Technology Data Exchange (ETDEWEB)

    Banister, W.C.

    1963-08-16

    Zirconium process tube No. 1986 was installed in KE Reactor tube channel No. 2864 on April 16, 1959. This report describes the history and the conditions to which it was exposed during its residence in the reactor. The tube was removed on May 31, 1963.

  4. Investigation of capillary nanosecond discharges in air at moderate pressure: comparison of experiments and 2D numerical modelling

    International Nuclear Information System (INIS)

    Nanosecond electrical discharges in the form of ionization waves are of interest for rapidly ionizing and exciting complex gas mixtures to initiate chemical reactions. Operating with a small discharge tube diameter can significantly increase the specific energy deposition and so enable optimization of the initiation process. Analysis of the uniformity of energy release in small diameter capillary tubes will aid in this optimization. In this paper, results for the experimentally derived characteristics of nanosecond capillary discharges in air at moderate pressure are presented and compared with results from a two-dimensional model. The quartz capillary tube, having inner and outer diameters of 1.5 and 3.4 mm, is about 80 mm long and filled with synthetic dry air at 27 mbar. The capillary tube with two electrodes at the ends is inserted into a break of the central wire of a long coaxial cable. A metal screen around the tube is connected to the cable ground shield. The discharge is driven by a 19 kV 35 ns voltage pulse applied to the powered electrode. The experimental measurements are conducted primarily by using a calibrated capacitive probe and back current shunts. The numerical modelling focuses on the fast ionization wave (FIW) and the plasma properties in the immediate afterglow after the conductive plasma channel has been established between the two electrodes. The FIW produces a highly focused region of electric field on the tube axis that sustains the ionization wave that eventually bridges the electrode gap. Results from the model predict FIW propagation speed and current rise time that agree with the experiment. (paper)

  5. Synthesis of a new family of Schiff base nonionic surfactants and evaluation of their corrosion inhibition effect on X-65 type tubing steel in deep oil wells formation water

    International Nuclear Information System (INIS)

    Some new Schiff base nonionic surfactants were synthesized and characterized using FTIR and 1H NMR spectroscopy. The corrosion inhibition effect of the synthesized surfactants on X-65 type tubing steel in deep oil wells formation water has been studied by polarization, electrochemical impedance spectroscopy (EIS) and weight loss measurements. Polarization data indicate that the selected surfactants act as mixed type (cathodic/anodic) inhibitors. EIS results show that the change in impedance parameters with the concentration of the surfactants studied is indicative of the adsorption of surfactant molecules on carbon steel surface. The adsorption of the inhibitors was well described by the Langmuir adsorption isotherm. Effect of temperature on the efficiency of the corrosion inhibition process was studied and the values of activation energy, enthalpy of activation and entropy of activation were calculated and discussed. The corrosion inhibition efficiency of the surfactants is correlated with surface tension measurements data. The protective film formed on the carbon steel surface was studied by scanning electron microscopy (SEM) and energy dispersive analysis of X-rays (EDX) techniques.

  6. 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

  7. 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.)

  8. 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.)

  9. Thru-tubing inflatable workover systems

    International Nuclear Information System (INIS)

    Recent technological advances in inflatable packing element design has allowed non-conventional workover techniques to be accomplished through the production tubing. The improved capabilities of these elements, coupled with new tool designs allowing workovers to be completed with coiled tubing or electric wireline, has seen growing applications. These workovers include, selective and zonal chemical treatments, temporary and permanent plugback operations, intermediate zone blankoff, production and injection flow profile modifications and formation fracturing. They are completed without pulling the production tubing from the well, and thus do not require a rig on the well. Since these tools are snubbed in the well with coiled tubing or electric wireline, thus eliminating the need to kill the well, heavy weight kill fluids, which may cause formation damage, are not required. These tools have been designed to operate with hydraulic pressure and workstring tension within the coiled tubing limitations. This paper outlines the development of these Thru-tubing systems and application techniques that have been developed as a result of their field use. It discusses case histories of applications using this technology and the resulting increase in well performance. This paper also describes auxiliary equipment that has been developed to allow these tool systems to be used safely on coiled tubing and electric wireline

  10. 21 CFR 868.5800 - Tracheostomy tube and tube cuff.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tracheostomy tube and tube cuff. 868.5800 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5800 Tracheostomy tube and tube cuff. (a) Identification. A tracheostomy tube and tube cuff is a device intended to be placed into...

  11. Direct withdrawal of zones during preparative capillary type isotachophoresis.

    Directory of Open Access Journals (Sweden)

    Yamada,Teruo

    1982-10-01

    Full Text Available This study used a Shimadzu IP-1B capillary type isotachophoretic apparatus with a potential gradient detector. An ipp-1 withdrawal cell was fitted to this and a technique for withdrawing individual components directly through this port was developed using a microsyringe. The recovery rate was up to 45% for individual target components. When 100% withdrawal of the target component was attempted by withdrawing a volume four times the calculated volume (so that the zones both before and after the target component were also included, the best recovery rate was only 78%. In all cases, the results varied less than 3%. The limit for analysis of individual components of a 0.01 M solution was around 3 microliters. If this volume was exceeded, the ion quantity was too large for the volume of the microcapillary tube and mixed zones formed such that complete separation and analysis of individual components became impossible.

  12. Imaging characteristics of glass capillary plate gas detector

    International Nuclear Information System (INIS)

    A glass capillary plate (CP) gas detector with gas mixtures of He, Ne, Ar, and Xe has been successfully operated as a visible and near-infrared (NIR) scintillation proportional counter. Gas gains of up to 104 can be achieved using these gas mixtures. The scintillation light emitted during the generation of electron avalanches can be observed using a photomultiplier tube (PMT) and a compact optical imaging system that consists of a CP gas detector and a cooled CCD camera coupled to lens optics. Using this optical imaging system, clearer X-ray images have been obtained with the above gas mixtures. The dependence of the imaging quality on the pressure in the range 0.25-1 atm was also investigated for the Ar (90%)+CF4 (10%) gas mixture. The successful operations using these gas mixtures have allowed us to realize a novel imaging device with a CP gas detector for gaseous PMTs sensitive to visible light.

  13. Developments of optical imaging capillary plate gas detector

    International Nuclear Information System (INIS)

    An optical imaging capillary plate (CP) gas detector has been successfully developed for a gas mixture of Ar+CF4. Gas gains of up to 104 can be achieved with a single CP. Scintillation light simultaneously emitted during the development of electron avalanches can be observed using a photomultiplier tube (PMT) and optical imaging system which consists of a CP gas detector and a cooled CCD camera coupled to lens optics. The energy resolutions obtained for the charge signal and the light signal were 22% and 24% for 10 keV X-rays, respectively. Using the optical imaging system, clearer images of X-rays have been obtained with the gas mixture. Successful operation with this gas mixture has allowed us to realise a novel-imaging device with CP for X-ray imaging, cold neutron imaging, medical imaging, and cellular function analysis

  14. A comparative study of Raman enhancement in capillaries

    Science.gov (United States)

    Eftekhari, Fatemeh; Irizar, Juan; Hulbert, Laila; Helmy, Amr S.

    2011-06-01

    This work reports on the comparative studies of Raman enhancement in liquid core waveguides (LCWs). The theoretical considerations that describe Raman enhancement in LCWs is adapted to analyze and compare the performance of hollow core photonic crystal fibers (HCPCFs) to conventional Teflon capillary tubes. The optical losses in both platforms are measured and used to predict their performance for different lengths. The results show that for an optimal waveguide length, two orders of magnitude enhancement in the Raman signal can be achieved for aqueous solutions using HCPCFs. This length, however, cannot be achieved using normal capillary effects. By integrating the interface of the fluidic pump and the HCPCF into a microfluidic chip, we are able to control fluid transport and fill longer lengths of HCPCFs regardless of the viscosity of the sample. The long-term stability and reproducibility of Raman spectra attained through this platform are demonstrated for naphthalenethiol, which is a well-studied organic compound. Using the HCPCF platform, the detection limit of normal Raman scattering in the range of micro-molars has been achieved. In addition to the higher signal-to-noise ratio of the Raman signal from the HCPCF-platform, more Raman modes of naphthalenethiol are revealed using this platform.

  15. Heat exchanger tube tool

    International Nuclear Information System (INIS)

    Certain types of heat-exchangers have tubes opening through a tube sheet to a manifold having an access opening offset from alignment with the tube ends. A tool for inserting a device, such as for inspection or repair, is provided for use in such instances. The tool is formed by a flexible guide tube insertable through the access opening and having an inner end provided with a connector for connection with the opening of the tube in which the device is to be inserted, and an outer end which remains outside of the chamber, the guide tube having adequate length for this arrangement. A flexible transport hose for internally transporting the device slides inside of the guide tube. This hose is long enough to slide through the guide tube, into the heat-exchanger tube, and through the latter to the extent required for the use of the device. The guide tube must be bent to reach the end of the heat-exchanger tube and the latter may be constructed with a bend, the hose carrying anit-friction elements at interspaced locations along its length to make it possible for the hose to negotiate such bends while sliding to the location where the use of the device is required

  16. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... NEI YouTube Videos > NEI YouTube Videos: Amblyopia NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration ... Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia NEI on Twitter NEI on YouTube ...

  17. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... YouTube Videos > NEI YouTube Videos: Amblyopia NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration Amblyopia ... of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia NEI on Twitter NEI on YouTube NEI ...

  18. 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

  19. Pediatric cuffed endotracheal tubes

    Directory of Open Access Journals (Sweden)

    Neerja Bhardwaj

    2013-01-01

    Full Text Available Endotracheal intubation in children is usually performed utilizing uncuffed endotracheal tubes for conduct of anesthesia as well as for prolonged ventilation in critical care units. However, uncuffed tubes may require multiple changes to avoid excessive air leak, with subsequent environmental pollution making the technique uneconomical. In addition, monitoring of ventilatory parameters, exhaled volumes, and end-expiratory gases may be unreliable. All these problems can be avoided by use of cuffed endotracheal tubes. Besides, cuffed endotracheal tubes may be of advantage in special situations like laparoscopic surgery and in surgical conditions at risk of aspiration. Magnetic resonance imaging (MRI scans in children have found the narrowest portion of larynx at rima glottides. Cuffed endotracheal tubes, therefore, will form a complete seal with low cuff pressure of <15 cm H 2 O without any increase in airway complications. Till recently, the use of cuffed endotracheal tubes was limited by variations in the tube design marketed by different manufacturers. The introduction of a new cuffed endotracheal tube in the market with improved tracheal sealing characteristics may encourage increased safe use of these tubes in clinical practice. A literature search using search words "cuffed endotracheal tube" and "children" from 1980 to January 2012 in PUBMED was conducted. Based on the search, the advantages and potential benefits of cuffed ETT are reviewed in this article.

  20. Nanoliter-scale sample preparation methods directly coupled to PMMA-based microchips and gel-filled capillaries for the analysis of oligonucleotides

    Science.gov (United States)

    Soper, Steven A.; Ford, Sean M.; Xu, Yichuan; Qi, Shize; McWhorter, Scott; Lassiter, Suzzane; Patterson, Don; Bruch, Richard C.

    1999-05-01

    We are currently developing miniaturized, chip-based electrophoresis devices fabricated in plastics for the high speed separation of oligonucleotides. One of the principal advantages associated with these devices is their small sample requirements, typically in the nanoliter to sub-nanoliter range. Unfortunately, most standard sample preparation protocols, especially for oligonucleotides, are done off-chip on a microliter-scale. Our work has focused on the development of capillary nano-reactors coupled to micro-separation platforms, such as micro-electrophoresis chips, for the preparation of sequencing ladders and also, PCR reactions. These nano-reactors consist of fused silica capillary tubes (length equals 10 - 20 cm; id equals 20 - 50 micrometer) with fluid pumping accomplished using the electro-osmotic flow generated by the tubes. These reactors were situated in fast thermal cyclers to perform cycle sequencing or PCR amplification of the DNAs. The reactors were interfaced to the micro-electrophoresis chips via capillary connectors micromachined in polymethylmethacrylate (PMMA) using deep X- ray etching (width equals 50 micrometer; depth equals 50 micrometer) and were situated directly on the PMMA-based microchip. This chip also contained an injector, separation channel (length equals 6 cm; width equals 30 micrometers; depth equals 50 micrometers) and a dual fiber optic, near- infrared fluorescence detector. The sequencing nano-reactor used surface immobilized templates attached to the wall via a biotin:streptavidin:biotin linkage produced by PCR using a biotinylated forward primer. Sequencing tracks could be directly injected into gel-filled capillary tubes with minimal degradation in the efficiency of the separation process. The nano-reactor could also be configured to perform PCR reactions by filling the capillary tube with the PCR reagents and template. After thermal cycling, the PCR cocktail could be injected into a capillary tube or a micro-chip device for

  1. Bulk metallic glass tube casting

    International Nuclear Information System (INIS)

    Research highlights: → Tubular specimens of Zr55Cu30Al10Ni5 cast in custom arc-melting furnace. → Tilt casting supplemented by suction casting. → Bulk metallic glass formed only with optimized processing parameters. → Fully amorphous tubes with 1.8 mm wall thickness and 25 mm diameter. - Abstract: Tubular bulk metallic glass specimens were produced, using a custom-built combined arc-melting tilt-casting furnace. Zr55Cu30Al10Ni5 tubes with outer diameter of 25 mm and 0.8-3 mm wall thicknesses were cast, with both tilt and suction casting to ensure mold filling. Tilt casting was found to fill one side of the tube mold first, with the rest of the tube circumference filled subsequently by suction casting. Optimized casting parameters were required to fully fill the mold and ensure glass formation. Too small melt mass and too low arc power filled the mold only partially. However, too large melt mass and higher arc power which lead to the best mold filling also lead to partial crystallization. Variations in processing parameters were explored, until a glassy ring with 1.8 mm thickness was produced. Different sections of the as-cast ring were investigated by X-ray diffraction (XRD), differential scanning calorimetry (DSC), and instrumented indentation to ensure amorphous microstructure. Atomic force microscopy (AFM) was used to compare the surface qualities of the first- and last-filled sections. These measurements confirmed the glassy structure of the cast ring, and that, the tilt cast tube section consistently showed better surface quality than the suction cast section. Optimized casting parameters are required to fully realize the potential of directly manufacturing complex shapes out of high-purity bulk metallic glasses by tilt casting.

  2. C18 silica packed capillary columns with monolithic frits prepared with UV light emitting diode: usefulness in nano-liquid chromatography and capillary electrochromatography.

    Science.gov (United States)

    D'Orazio, Giovanni; Fanali, Salvatore

    2012-04-01

    In this paper the potential of fused silica capillaries packed with RP18 silica particles entrapped with monolithic frits using both nano-liquid chromatography (nano-LC) and capillary electrochromatography (CEC) was investigated. Frits were prepared after removing a short part of the polyimide layer on the capillary wall and irradiating the polymerization mixture with an UV-light emitter diode (LED) at 370 nm. The capillary, was rotated during the polymerization procedure in order to obtain a homogeneous monolith. The distance of the LED from the capillary and the exposure time to UV light were studied in order to obtain frits with good porosity and high robustness. A mixture containing five alkylbenzenes was selected as sample and analyzed by both nano-LC and CEC. The standard mixture was baseline separated with good efficiency in the range 78,000-93,000 and 99,000-113,000 plates/m in nano-LC and CEC, respectively. The columns resulted to be very robust and the prepared monolithic frits allowed working with backpressure as high as 400 bar (nano-LC). In addition high voltages were applied in CEC (25-30 kV) without bubbles formation in absence of pressure assistance during runs. PMID:22189300

  3. Liquid metal folding patterns induced by electric capillary force

    Science.gov (United States)

    Wang, Lei; Liu, Jing

    2016-04-01

    A fundamental phenomenon regarding spontaneous formation of symmetrical folding patterns induced on liquid metal free surface with circular shape features was disclosed. The occurrence and evolution processes of the patterns were demonstrated and interpreted. The electric capillary force imposed on liquid metal due to surface tension gradient was found responsible for producing a variety of surface folding patterns like wheel-shape, dual concentric ring-shape, and so on. All the patterns display a property of axial symmetry and could be analogue to the Rayleigh-Benard convection which produces hexagonal patterns. This finding on liquid metal flow folding refreshes knowledge of classical fluid kinematics.

  4. Formation of MSeO4(aq) complexes (M2+ = Mg2+, Co2+, Ni2+, Cu2+, Cd2+) studied as a function of temperature by affinity capillary electrophoresis

    International Nuclear Information System (INIS)

    Complexation of divalent cations (Mg2+, Co2+, Ni2+, Cu2+, Cd2+) by selenate ligand was studied by ACE (UV indirect detection) in 0.1 mol/L NaNO3 ionic strength solutions at various temperatures (15, 25, 35, 45 and 55 C). For each solution, a unique peak was observed as a result of a fast equilibrium between the free ion and the complex (labile systems). The migration time corresponding to this peak changed as a function of the solution composition, namely the free and complexed metal concentrations, according to the complexation reactions. The results confirmed the formation of a unique 1:1 complex for each cation. The thermodynamic parameters were fitted to the experimental data at 0.1 mol/L ionic strength: ΔfG0.1M(MSeO4(aq))(25 C) = -(6.5 ± 0.3), -(7.5 ± 0.3), -(7.7 ± 0.3), -(7.7 ± 0.3), and -(8.1 ± 0.3) kJ/mol and ΔfH0.1M(MSeO4(aq)) = 2.5 ± 0.2, 4.7 ± 0.4, 4.5 ± 0.6, 8.4 ± 1.1, and 7.2 ± 0.6 kJ/mol for M2+ = Mg2+, Co2+, Ni2+, Cu2+, and Cd2+, respectively. Complexes with alkaline earth and transition metal cations could be distinguished by their relative stabilities. The effect of the ionic medium was treated using the specific ion interaction theory and the thermodynamic parameters at infinite dilution were compared to previously published data on metal-selenate, metal-sulfate, and metal-chromate complexes. (authors)

  5. Properties of Plasma Jets Emitted in Pulsed Capillary Discharges at Low Pressures

    International Nuclear Information System (INIS)

    The characteristic geometry of a pulsed capillary discharge (PCD), a narrow open end tube with a large aspect ratio, establishes natural conditions for the generation of plasma jets, that propagate in the neutral background gas surrounding the capillary. We have investigated the plasma jet emission in a PCD, with electron beam assisted on-axis initiation. A local storage capacitor, coaxial with the capillary assembly, is pulse charged up to a maximum of -11 kV, which results in an initial ∼ 10 ns, ∼ 2 kA current pulse. The discharge is operated in Argon and Nitrogen, in a continuous pulsing mode, at frequencies between 5 to 20 Hz, and in a pressure range between 300 to 1100 Torr. A fast Langmuir probe, placed at the anode side, close to the capillary exit, is used to measure the characteristic electron temperature (Te) and electron density (Ne) of the plasma jets. Results obtained in Nitrogen at 10 Hz indicate that Te is in the 10 to 60 eV range with Ne of the order of 1014 (cm-3). Significant changes in the probe floating potential are observed for a fixed operating pressure when the pulsing frequency is varied, which can be ascribed to the presence of metastables in the gas fed into the capillary, which result from the interaction of the plasma jet with the plenum gas, at the cathode side. The presence of metastables reduces the energy cost involved in the capillary plasma production, which results in a pulsing frequency dependence of the plasma parameters

  6. "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

  7. Conduction cooled tube supports

    Science.gov (United States)

    Worley, Arthur C.; Becht, IV, Charles

    1984-01-01

    In boilers, process tubes are suspended by means of support studs that are in thermal contact with and attached to the metal roof casing of the boiler and the upper bend portions of the process tubes. The support studs are sufficiently short that when the boiler is in use, the support studs are cooled by conduction of heat to the process tubes and the roof casing thereby maintaining the temperature of the stud so that it does not exceed 1400.degree. F.

  8. Tubing weld cracking test

    International Nuclear Information System (INIS)

    A tubing weld cracking (TWC) test was developed for applications involving advanced austenitic alloys (such as modified 800H and 310HCbN). Compared to the Finger hot cracking test, the TWC test shows an enhanced ability to evaluate the crack sensitivity of tubing materials. The TWC test can evaluate the cracking tendency of base as well as filter materials. Thus, it is a useful tool for tubing suppliers, filler metal producers and fabricators

  9. Carburization of stainless steel furnace tubes

    International Nuclear Information System (INIS)

    Stainless steel containing molybdenum are usually recommended to resist naphtenic acid corrosion in vacuum heaters. In 1993 the original 5Cr-1/2Mo roof tubes of the furnace in a vacuum unit were replaced by stainless steel 316 Ti to minimize tube replacement and increase heater reliability. Unexpectedly, some of the new tubes failed after only three years of service and just one year after undergoing the last inspection. The damage occurred in the form of deep holes and perforations, starting from the outside tube surface on the fireside. Coke build-up occurred due to severe operating conditions, overheating the tubes on the fireside, above 675 Centigrade. Metallographic and Scanning Electron Microscopy (Sem) examination revealed internal and external carburization of the material due to the presence of coke and combustion ashes, respectively. The increase in the skin metal temperature facilitated the diffusion of carbon from these carbon-rich deposits into the low carbon content material (0.023%). Depletion of chromium at the grain boundaries due to the massive formation of chromium carbides, resulted in a severe intergranular corrosion attack by molten salts rich in vanadium and sulfur produced by asphalt burning. Normal operating practice demands the use of steam for the heater tubes to control coke build-up. This practice had been first reduced and then eliminated, during the past two years prior to the failure, because of economic incentives. This paper describes the root cause analysis conducted to account for these premature tube failures. (Author)

  10. Characterization of antigens specific to the surface of germ tubes of Candida albicans by immunofluorescence.

    OpenAIRE

    Sundstrom, P M; Kenny, G. E.

    1984-01-01

    To characterize germ tube-specific antigens of Candida albicans, rabbit antiserum prepared to Formalin-treated yeast possessing germ tubes was adsorbed with stationary-phase blastospores. By immunofluorescence and enzyme-linked immunosorbent assay, this antibody did not react with blastospores but detected germ tube-specific antigens in hyphal forms. Germ tube-specific antigens appeared 30 min after placing blastospores in appropriate conditions for germ tube formation. Hyphae, formed by allo...

  11. Categorising YouTube

    OpenAIRE

    Thomas Mosebo Simonsen

    2011-01-01

    This article provides a genre analytical approach to creating a typology of the User Generated Content (UGC) of YouTube. The article investigates the construction of navigation processes on the YouTube website. It suggests a pragmatic genre approach that is expanded through a focus on YouTube’s technological affordances. Through an analysis of the different pragmatic contexts of YouTube, it is argued that a taxonomic understanding of YouTube must be analysed in regards to the vacillation of a...

  12. Calibrations of photomultiplier tubes

    International Nuclear Information System (INIS)

    The experimental methods for calibration photomultiplier tubes used in the multichannel fast-pulse-detection system of Thomson scattering measurements for nuclear fusion devices is reported. The most important parameters of the photomultiplier tubes to be calibrated include: linearity of output electric signals to input light signals, response time of pulsed light, spectral response, absolute responsibility, and sensitivity as a function of the chain voltage. The calibrations of all these parameters are carried out by using EMI 9558 B and RCA 7265 photomultiplier tubes respectively. The experimental methods presented in the paper are common to those quantitative measurements that require phomultiplier tubes as detectors

  13. Composite Pulse Tube

    Science.gov (United States)

    Martin, Jerry L.; Cloyd, Jason H.

    2007-01-01

    A modification of the design of the pulse tube in a pulse-tube cryocooler reduces axial thermal conductance while preserving radial thermal conductance. It is desirable to minimize axial thermal conductance in the pulse-tube wall to minimize leakage of heat between the warm and cold ends of the pulse tube. At the same time, it is desirable to maximize radial thermal conductance at the cold end of the pulse tube to ensure adequate thermal contact between (1) a heat exchanger in the form of a stack of copper screens inside the pulse tube at the cold end and (2) the remainder of the cold tip, which is the object to which the heat load is applied and from which heat must be removed. The modified design yields a low-heat-leak pulse tube that can be easily integrated with a cold tip. A typical pulse tube of prior design is either a thin-walled metal tube or a metal tube with a nonmetallic lining. It is desirable that the outer surface of a pulse tube be cylindrical (in contradistinction to tapered) to simplify the design of a regenerator that is also part of the cryocooler. Under some conditions, it is desirable to taper the inner surface of the pulse tube to reduce acoustic streaming. The combination of a cylindrical outer surface and a tapered inner surface can lead to unacceptably large axial conduction if the pulse tube is made entirely of metal. Making the pulse-tube wall of a nonmetallic, lowthermal- conductivity material would not solve the problem because the wall would not afford the needed thermal contact for the stack of screens in the cold end. The modified design calls for fabricating the pulse tube in two parts: a longer, nonmetallic part that is tapered on the inside and cylindrical on the outside and a shorter, metallic part that is cylindrical on both the inside and the outside. The nonmetallic part can be made from G-10 fiberglass-reinforced epoxy or other low-thermal-conductivity, cryogenically compatible material. The metallic part must have high

  14. Manual tube welding torch

    International Nuclear Information System (INIS)

    In a welding torch which fits over a tube intermediate the ends thereof for welding the juncture between the tube and a boss on the back side of a tube plate, a split housing encloses a tungsten electrode, a filler wire duct and a fiber optic bundle arranged to observe the welding process. A shielding gas duct is provided in the housing. A screw is provided for setting electrode/work distance. Difficult remote tube welding operations can be performed with the apparatus. (author)

  15. Steam generator tube performance

    International Nuclear Information System (INIS)

    A survey of steam generator operating experience for 1986 has been carried out for 184 pressurized water and pressurized heavy-water reactors, and 1 water-cooled, graphite-moderated reactor. Tubes were plugged at 75 of the reactors (40.5%). In 1986, 3737 tubes were plugged (0.14% of those in service) and 3148 tubes were repaired by sleeving. A small number of reactors accounted for the bulk of the plugged tubes, a phenomenon consistent with previous years. For 1986, the available tubesheet sludge data for 38 reactors has been compiled into tabular form, and sludge/deposit data will be incorporated into all future surveys

  16. 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

  17. 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 ...

  18. 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...

  19. 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

  20. 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...

  1. Organically-doped sol-gel based tube detectors: Determination of iron(II) in aqueous solutions.

    Science.gov (United States)

    Kuselman, I; Lev, O

    1993-05-01

    A novel type of disposable sensor for the determination of iron(II) in aqueous solution is described. The iron sensor serves to exemplify a new class of disposable field tests for field analysis of water pollutants. The sensors are comprised of capillary glass tubes filled with porous sol-gel silica powder doped with o-phenanthroline. When a sample solution is passed through a tube detector the iron ions are complexed by the immobilized o-phenanthroline and a stained section of the capillary develops. Metrological characteristics of these detectors including precision and accuracy and chemical interferences by heavy metals and humic acids are discussed. PMID:18965698

  2. Steam generator tube failures

    Energy Technology Data Exchange (ETDEWEB)

    MacDonald, P.E.; Shah, V.N.; Ward, L.W.; Ellison, P.G.

    1996-04-01

    A review and summary of the available information on steam generator tubing failures and the impact of these failures on plant safety is presented. The following topics are covered: pressurized water reactor (PWR), Canadian deuterium uranium (CANDU) reactor, and Russian water moderated, water cooled energy reactor (VVER) steam generator degradation, PWR steam generator tube ruptures, the thermal-hydraulic response of a PWR plant with a faulted steam generator, the risk significance of steam generator tube rupture accidents, tubing inspection requirements and fitness-for-service criteria in various countries, and defect detection reliability and sizing accuracy. A significant number of steam generator tubes are defective and are removed from service or repaired each year. This wide spread damage has been caused by many diverse degradation mechanisms, some of which are difficult to detect and predict. In addition, spontaneous tube ruptures have occurred at the rate of about one every 2 years over the last 20 years, and incipient tube ruptures (tube failures usually identified with leak detection monitors just before rupture) have been occurring at the rate of about one per year. These ruptures have caused complex plant transients which have not always been easy for the reactor operators to control. Our analysis shows that if more than 15 tubes rupture during a main steam line break, the system response could lead to core melting. Although spontaneous and induced steam generator tube ruptures are small contributors to the total core damage frequency calculated in probabilistic risk assessments, they are risk significant because the radionuclides are likely to bypass the reactor containment building. The frequency of steam generator tube ruptures can be significantly reduced through appropriate and timely inspections and repairs or removal from service.

  3. Steam generator tube failures

    International Nuclear Information System (INIS)

    A review and summary of the available information on steam generator tubing failures and the impact of these failures on plant safety is presented. The following topics are covered: pressurized water reactor (PWR), Canadian deuterium uranium (CANDU) reactor, and Russian water moderated, water cooled energy reactor (VVER) steam generator degradation, PWR steam generator tube ruptures, the thermal-hydraulic response of a PWR plant with a faulted steam generator, the risk significance of steam generator tube rupture accidents, tubing inspection requirements and fitness-for-service criteria in various countries, and defect detection reliability and sizing accuracy. A significant number of steam generator tubes are defective and are removed from service or repaired each year. This wide spread damage has been caused by many diverse degradation mechanisms, some of which are difficult to detect and predict. In addition, spontaneous tube ruptures have occurred at the rate of about one every 2 years over the last 20 years, and incipient tube ruptures (tube failures usually identified with leak detection monitors just before rupture) have been occurring at the rate of about one per year. These ruptures have caused complex plant transients which have not always been easy for the reactor operators to control. Our analysis shows that if more than 15 tubes rupture during a main steam line break, the system response could lead to core melting. Although spontaneous and induced steam generator tube ruptures are small contributors to the total core damage frequency calculated in probabilistic risk assessments, they are risk significant because the radionuclides are likely to bypass the reactor containment building. The frequency of steam generator tube ruptures can be significantly reduced through appropriate and timely inspections and repairs or removal from service

  4. Pyrotechnic Tubing Connector

    Science.gov (United States)

    Graves, Thomas J.; Yang, Robert A.

    1988-01-01

    Tool forms mechanical seal at joint without levers or hydraulic apparatus. Proposed tool intended for use in outer space used on Earth by heavily garbed workers to join tubing in difficult environments. Called Pyrotool, used with Lokring (or equivalent) fittings. Piston slides in cylinder when pushed by gas from detonating pyrotechnic charge. Impulse of piston compresses fittings, sealing around butting ends of tubes.

  5. Welding Tubes In Place

    Science.gov (United States)

    Meredith, R.

    1984-01-01

    Special welding equipment joins metal tubes that carry pressurized cyrogenic fluids. Equipment small enough to be used in confined spaces in which such tubes often mounted. Welded joints lighter in weight and more leak-proof than joints made with mechanical fittings.

  6. The effect of surface tension on flow condensation in vertical small-diameter tube

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The effect of surface tension on flow condensation in vertical small tube with inside diameter of 1-5 mm is compared with that of gravity and shear stress in different gravity environments at low Reynolds number, whichis less concerned in former studies. The present study indicates that surface tension is the most important factor affectingflow condensation, but it is weakened by shear stress as decreasing tube diameter in a microgravity environment. In anormal gravity environment, body force is the dominant effect that is weakened by shear stress as decreasing tube diame-ter, while the effect of capillary pressure drop due to surface tension is enhanced. The work will be helpful in under-standing the characteristics of heat pipe or capillary pumped loop (CPL) at low Reynolds number.

  7. Liquid Film Capillary Mechanism for Densification of Ceramic Powders during Flash Sintering

    Directory of Open Access Journals (Sweden)

    Rachman Chaim

    2016-04-01

    Full Text Available Recently, local melting of the particle surfaces confirmed the formation of spark and plasma during spark plasma sintering, which explains the rapid densification mechanism via liquid. A model for rapid densification of flash sintered ceramics by liquid film capillary was presented, where liquid film forms by local melting at the particle contacts, due to Joule heating followed by thermal runaway. Local densification is by particle rearrangement led by spreading of the liquid, due to local attractive capillary forces. Electrowetting may assist this process. The asymmetric nature of the powder compact represents an invasive percolating system.

  8. 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

  9. Categorising YouTube

    DEFF Research Database (Denmark)

    Simonsen, Thomas Mosebo

    2011-01-01

    This article provides a genre analytical approach to creating a typology of the User Generated Content (UGC) of YouTube. The article investigates the construction of navigation processes on the YouTube website. It suggests a pragmatic genre approach that is expanded through a focus on YouTube’s...... technological affordances. Through an analysis of the different pragmatic contexts of YouTube, it is argued that a taxonomic understanding of YouTube must be analysed in regards to the vacillation of a user-driven bottom-up folksonomy and a hierarchical browsing system that emphasises a culture of competition...... and which favours the already popular content of YouTube. With this taxonomic approach, the UGC videos are registered and analysed in terms of empirically based observations. The article identifies various UGC categories and their principal characteristics. Furthermore, general tendencies of the UGC...

  10. High-current carbon-epoxy capillary cathode

    Science.gov (United States)

    Gleizer, J. Z.; Queller, T.; Bliokh, Yu.; Yatom, S.; Vekselman, V.; Krasik, Ya. E.; Bernshtam, V.

    2012-07-01

    The results of experiments on the reproducible generation of an electron beam having a high current density of up to 300 A/cm2 and a satisfactorily uniform cross-sectional distribution of current density in a ˜200 kV, ˜450 ns vacuum diode with a carbon-epoxy capillary cathode are presented. It was found that the source of the electrons is the plasma formed as a result of flashover inside the capillaries. It is shown that the plasma formation occurs at an electric field ≤15 kV/cm and that the cathode sustains thousands of pulses without degradation in its emission properties. Time- and space-resolved visible light observation and spectroscopy analyses were used to determine the cathode plasma's density, temperature, and expansion velocity. It was found that the density of the cathode plasma decreases rapidly in relation to the distance from the cathode. In addition, it was found that the main reason for the short-circuiting of the accelerating gap is the formation and expansion of the anode plasma. Finally, it was shown that when an external guiding magnetic field is present, the injection of the electron beam into the drift space with a current amplitude exceeding its critical value changes the radial distribution of the current density of the electron beam because the inner electrons are reflected from the virtual cathode.

  11. 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

  12. 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

  13. High-temperature separation with polymer-coated fiber in packed capillary gas chromatography.

    Science.gov (United States)

    Saito, Yoshihiro; Ogawa, Mitsuhiro; Imaizumi, Motohiro; Ban, Kazuhiro; Abe, Akira; Takeichi, Tsutomu; Wada, Hiroo; Jinno, Kiyokatsu

    2005-06-01

    High-temperature gas chromatographic separation of several synthetic polymer mixtures with Dexsil-coated fiber-packed columns was studied. A bundle of heat-resistant filaments, Zylon, was longitudinally packed into a short metal capillary, followed by the conventional coating process with Dexsil 300 material. Prior to the packing process the metal capillary was deactivated by the formation of a silica layer. The typical size of the resulting column was 0.3-mm i.d., 0.5-mm o.d., 1-m length, and packed with about 170 filaments of the Dexsil-coated Zylon. The column temperature could be elevated up to 450 degrees C owing to the good thermal stability of the fiber, Dexsil coating, and metal capillary; furthermore, this allowed the separation of low-volatile compounds to be studied. PMID:15933854

  14. Analysis of protamine peptides in insulin pharmaceutical formulations by capillary electrophoresis.

    Science.gov (United States)

    Lamalle, Caroline; Servais, Anne-Catherine; Demelenne, Alice; Crommen, Jacques; Fillet, Marianne

    2016-03-01

    Protamines are a group of highly basic peptides that are sometimes added to insulin formulations to prolong the pharmacological action. In this study, different methods were investigated to identify protamine in insulin formulations. Capillary electrophoresis in aqueous and non-aqueous media was tested to separate these peptides with very close amino acid sequences. Different buffers (phosphate or formate, both acidified) and various additives (principally negatively charged and neutral surfactants) were investigated to optimize peptide separation. Finally, a micellar electrokinetic capillary chromatography method using a capillary of 120 cm effective length and an aqueous background electrolyte made up of 100 mM phosphate buffer (pH 2) and 50 mM Thesit® gave the best results, providing the separation of the four major protamine peptides within 25 min. PMID:26829340

  15. 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

  16. 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.

  17. 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...

  18. Relapse of diabetic ketoacidosis secondary to insulin pump malfunction diagnosed by capillary blood 3-hydroxybutyrate: a case report

    OpenAIRE

    Baird, John Scott

    2009-01-01

    A 14 year old female with type 1 diabetes mellitus and a subcutaneous insulin pump was treated for diabetic ketoacidosis presumed secondary to dietary indiscretion, and then restarted her subcutaneous insulin pump after exchanging the tubing. An hour later, nursing review determined that she was using outdated insulin in the pump, and it was exchanged. However, 5 hours later relapse was suggested by a rise in capillary blood 3-hydroxybutyrate, in spite of a normal serum anion gap and a minima...

  19. Pressure tube type reactor

    International Nuclear Information System (INIS)

    Heretofore, a pressure tube type reactor has a problem in that the evaluation for the reactor core performance is complicate and no sufficient consideration is made for the economical property, to increase the size of a calandria tank and make the cost expensive. Then, in the present invention, the inner diameter of a pressure tube is set to greater than 50% of the lattice gap in a square lattice like arrangement, and the difference between the inner and the outer diameters of the calandria tube is set smaller than 20% of the lattice gap. Further, the inner diameter of the pressure tube is set to greater than 40% and the difference between the inner and the outer diameters of the calandria tube is set smaller than 30% of the lattice gap in a triangle lattice arrangement. Then, heavy water-to-fuel volume ratio can be determined appropriately and the value for the coolant void coefficient is made more negative side, to improve the self controllability inherent to the reactor. In particular, when 72 to 90 fuel rods are arranged per one pressure tube, the power density per one fuel rod is can be increased by about twice. Accordingly, the number of the pressure tubes can be reduced about to one-half, thereby enabling to remarkably decrease the diameter of the reactor core and to reduce the size of the calandria, which is economical. (N.H.)

  20. 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.

  1. Cardiac function, microvascular structure, and capillary hematocrit in hearts of polycythemic rats.

    Science.gov (United States)

    Rakusan, K; Cicutti, N; Kolar, F

    2001-12-01

    The effect of polycythemia on the coronary microcirculation was studied in young male rats. Two experimental models of polycythemia were employed: cobalt-induced polycythemia, which mimics hypoxia-induced changes, and erythropoietin-induced polycythemia, which circumvents these changes. In both models, baseline left ventricular function was normal, whereas maximal systolic and developed pressures were decreased. In cobalt-treated rats the left ventricular functional reserve was also compromised. Morphometric analysis of the left ventricle confirmed previously described improved geometric conditions for oxygen supply at the distal portions of capillaries (smaller domain areas and shorter capillary segments). In cobalt-treated but not in erythropoietin-treated rats, increased capillary angiogenesis was also detected. In the hearts from rats with both types of polycythemia, a small but significant increase in the formation of arterioles was found. Capillary linear hematocrit was within the normal range in both types of polycythemia despite sizeable increases in systemic hematocrit. Significant differences in red blood cell distribution within capillaries were found between proximal and distal portions in all experimental groups. PMID:11709408

  2. 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

  3. 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.

  4. 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.

  5. YouTube, aneb tajemství videa a zvuku

    OpenAIRE

    Voců, Ondřej

    2011-01-01

    First part of this article describes basics of video and audio on PC. Multimedia containers, video codecs and audio formats are mentioned. In the second part, YouTube as a portal is analysed. The second part also consist of particular analysis of the five most important sites of YouTube – main page, video playback page, user channel page, account settings page and TestTube. At the end of second part of this article, three main ways of downloading video from YouTube are introduced. Third and l...

  6. Polyvinylpyrrolidone-sodium dodecylsulfate complex is a family of pseudo-polyanions with different charge densities: Evidence from capillary electrophoresis, capillary viscosimetry and conductometry.

    Science.gov (United States)

    Wu, Yefan; Chen, Jie; Fang, Yun; Zhu, Meng

    2016-10-01

    Accordance with the previously supposed polyelectrolyte-like behaviour of neutral polymer-anionic surfactant complexes, direct evidence for the formation of the pseudo-polyanions in polyvinylpyrrolidone (PVP)-sodium dodecylsulfate (SDS) solution is put forward in this paper by capillary electrophoresis (CE) experiments in assistance with capillary viscosimetry and conductometry. The contradictory phenomena of the absolute value of relative electrophoretic mobility (re) increasing while the ionization degree (α) decreasing with the increasing specific clusterization [Г] in aqueous PVP-SDS solution are explained by the finding that the PVP-SDS complex is eventually a family of PVP-SDS pseudo-polyanions with different charge densities. And it is found countercations playing an important role in the formation of the PVP-SDS pseudo-polyanions in virtue of bridge effect. PMID:27348481

  7. Influence of local capillary trapping on containment system effectiveness

    Energy Technology Data Exchange (ETDEWEB)

    Bryant, Steven [University Of Texas At Austin, Austin, TX (United States). Center for Petroleum and Geosystems Engineering

    2014-03-31

    Immobilization of CO2 injected into deep subsurface storage reservoirs is a critical component of risk assessment for geologic CO2 storage (GCS). Local capillary trapping (LCT) is a recently established mode of immobilization that arises when CO2 migrates due to buoyancy through heterogeneous storage reservoirs. This project sought to assess the amount and extent of LCT expected in storage formations under a range of injection conditions, and to confirm the persistence of LCT if the seal overlying the reservoir were to lose its integrity. Numerical simulation using commercial reservoir simulation software was conducted to assess the influence of injection. Laboratory experiments, modeling and numerical simulation were conducted to assess the effect of compromised seal integrity. Bench-scale (0.6 m by 0.6 m by 0.03 m) experiments with surrogate fluids provided the first empirical confirmation of the key concepts underlying LCT: accumulation of buoyant nonwetting phase at above residual saturations beneath capillary barriers in a variety of structures, which remains immobile under normal capillary pressure gradients. Immobilization of above-residual saturations is a critical distinction between LCT and the more familiar “residual saturation trapping.” To estimate the possible extent of LCT in a storage reservoir an algorithm was developed to identify all potential local traps, given the spatial distribution of capillary entry pressure in the reservoir. The algorithm assumes that the driving force for CO2 migration can be represented as a single value of “critical capillary entry pressure” Pc,entrycrit, such that cells with capillary entry pressure greater/less than Pc,entrycrit act as barriers/potential traps during CO2 migration. At intermediate values of Pc,entrycrit, the barrier regions become more laterally extensive in the reservoir

  8. The tracheal tube: gateway to ventilator-associated pneumonia

    OpenAIRE

    Zolfaghari, Parjam S; Wyncoll, Duncan LA

    2011-01-01

    Ventilator-associated pneumonia (VAP) is a major healthcare-associated complication with considerable attributable morbidity, mortality and cost. Inherent design flaws in the standard high-volume low-pressure cuffed tracheal tubes form a major part of the pathogenic mechanism causing VAP. The formation of folds in the inflated cuff leads to microaspiration of pooled oropharyngeal secretions into the trachea, and biofilm formation on the inner surface of the tracheal tube helps to maintain bac...

  9. Magnetic flux tube tunneling

    International Nuclear Information System (INIS)

    We present numerical simulations of the collision and subsequent interaction of orthogonal magnetic flux tubes. The simulations were carried out using a parallelized spectral algorithm for compressible magnetohydrodynamics. It is found that, under a wide range of conditions, the flux tubes can open-quotes tunnelclose quotes through each other, a behavior not previously seen in studies of either vortex tube or magnetic flux tube interactions. Two conditions must be satisfied for tunneling to occur: the magnetic field must be highly twisted with a field line pitch >1, and the Lundquist number must be somewhat large, ≥2880. An examination of magnetic field lines suggests that tunneling is due to a double-reconnection mechanism. Initially orthogonal field lines reconnect at two specific locations, exchange interacting sections, and open-quotes passclose quotes through each other. The implications of these results for solar and space plasmas are discussed. copyright 1997 The American Physical Society

  10. Integrated structure vacuum tube

    Science.gov (United States)

    Dimeff, J.; Kerwin, W. J. (Inventor)

    1976-01-01

    High efficiency, multi-dimensional thin film vacuum tubes suitable for use in high temperature, high radiation environments are described. The tubes are fabricated by placing thin film electrode members in selected arrays on facing interior wall surfaces of an alumina substrate envelope. Cathode members are formed using thin films of triple carbonate. The photoresist used in photolithography aids in activation of the cathodes by carbonizing and reacting with the reduced carbonates when heated in vacuum during forming. The finely powdered triple carbonate is mixed with the photoresist used to delineate the cathode locations in the conventional solid state photolithographic manner. Anode and grid members are formed using thin films of refractory metal. Electron flow in the tubes is between grid elements from cathode to anode as in a conventional three-dimensional tube.

  11. 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...

  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. Neural Tube Defects

    OpenAIRE

    Greene, Nicholas D. E.; Copp, Andrew J.

    2014-01-01

    Neural tube defects (NTDs), including spina bifida and anencephaly, are severe birth defects of the central nervous system that originate during embryonic development when the neural tube fails to close completely. Human NTDs are multifactorial, with contributions from both genetic and environmental factors. The genetic basis is not yet well understood, but several nongenetic risk factors have been identified as have possibilities for prevention by maternal folic acid supplementation. Mechani...

  15. Power vacuum tubes handbook

    CERN Document Server

    Whitaker, Jerry

    2012-01-01

    Providing examples of applications, Power Vacuum Tubes Handbook, Third Edition examines the underlying technology of each type of power vacuum tube device in common use today. The author presents basic principles, reports on new development efforts, and discusses implementation and maintenance considerations. Supporting mathematical equations and extensive technical illustrations and schematic diagrams help readers understand the material. Translate Principles into Specific Applications This one-stop reference is a hands-on guide for engineering personnel involved in the design, specification,

  16. Aeronautical tubes and pipes

    Science.gov (United States)

    Beauclair, N.

    1984-12-01

    The main and subcomponent French suppliers of aircraft tubes and pipes are discussed, and the state of the industry is analyzed. Quality control is essential for tubes with regard to their i.d. and metallurgical compositions. French regulations do not allow welded seam tubes in hydraulic circuits unless no other form is available, and then rustproofed steel must be installed. The actual low level of orders for any run of tubes dictates that the product is only one of several among the manufacturers' line. Automation, both in NDT and quality control, assures that the tubes meet specifications. A total of 10 French companies participate in the industry, serving both civil and military needs, with some companies specializing only in titanium, steel, or aluminum materials. Concerns wishing to enter the market must upgrade their equipment to meet the higher aeronautical specifications and be prepared to furnish tubes and pipes that serve both functional and structural purposes simultaneously. Additionally, pipe-bending machines must also perform to tight specifications. Pipes can range from 0.2 mm exterior diameter to 40 mm, with wall thicknesses from 0.02 mm to 3 mm. A chart containing a list of manufacturers and their respective specifications and characteristics is presented, and a downtrend in production with reduction of personnel is noted.

  17. 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.

  18. 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

  19. 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.

  20. 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

  1. 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.

  2. Copper phosphorus brazing for copper tubing. Dohaikan no rindo rozuke

    Energy Technology Data Exchange (ETDEWEB)

    Kanai, A. (Industrial Research Institute of Kanagawa Prefecture, Kanagawa (Japan))

    1993-04-01

    This paper explains copper phosphorus torch brazing for copper tubing used in construction facilities as the main object of discussion. Copper phosphorus brazing requires no flux in brazing copper with copper and copper with bronze because of self-fluxing action of phosphorus. Jointing steel tubing with copper tubing is impossible. Brazing is possible even at temperatures below the liquid-phase line where good beads can be obtained. It allows larger tolerance for clearance than soldering and silver brazing. In the working process, the final clean surface turns to bright copper while producing flux, Cu3P, slag and gas P2O5. According to void prediction based on the relation of clearance between a copper tube and a joint with capillary rising height, a brazed joint without a defect can be obtained if the nominal diameter is 32A or less. Six kinds of copper phosphorus brazing fillers are specified in JIS, the best filler being BCuP-3. The suitable temperature for brazing is in high temperature zones of about 800[degree]C, but a work is performed preferably while watching fillet being formed at about 700[degree]C. The minimum required penetration depth should be twice as much as the steel tube wall thickness, while the minimum bonding area should be quadruple as much. 10 figs., 1 tab.

  3. Prevention of Neural Tube Defects. ARC Q&A #101-45.

    Science.gov (United States)

    Arc, Arlington, TX.

    This fact sheet uses a question-and-answer format to summarize issues related to the prevention of neural tube defects. Questions and answers address the following topics: what neural tube defects are and the most common types (spina bifida and anencephaly); occurrence of neural tube defects during the first month of pregnancy; the frequency of…

  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. Capillary-force measurement on SiC surfaces.

    Science.gov (United States)

    Sedighi, M; Svetovoy, V B; Palasantzas, G

    2016-06-01

    Capillary forces have been measured by atomic force microscopy in the sphere-plate geometry, in a controlled humidity environment, between smooth silicon carbide and borosilicate glass spheres. The force measurements were performed as a function of the rms surface roughness ∼4-14 nm mainly due to sphere morphology, the relative humidity (RH) ∼0%-40%, the applied load on the cantilever, and the contact time. The pull-off force was found to decrease by nearly two orders of magnitude with increasing rms roughness from 8 to 14 nm due to formation of a few capillary menisci for the roughest surfaces, while it remained unchanged for rms roughness <8 nm implying fully wetted surface features leading to a single meniscus. The latter reached a steady state in less than 5 s for the smoothest surfaces, as force measurements versus contact time indicated for increased RH∼40%. Finally, the pull-off force increases and reaches a maximum with applied load, which is associated with plastic deformation of surface asperities, and decreases at higher loads. PMID:27415337

  6. 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.

  7. Thermal Energy Storage in the Ground of a Greenhouse by the Polypropylene Capillary Heat Exchanger

    Directory of Open Access Journals (Sweden)

    M. Lazâar

    2008-01-01

    Full Text Available The problem of temperature inversion is one of solar origin principal problems about which the cultures under shelters complain. Indeed, for the winter period, the temperature under greenhouse is very low at night and it is rather high during the day in summer. Consequently, the heating of the greenhouses is essential. In this work, we studied the advisability of using two exchangers coupled between them to manage thermal energy in a greenhouse. The first system is a battery of plaits with capillary tubes buried under ground with a depth of 70 cm. The second is an air exchanger based on plastic tubes black known as agrotherms suspended with two meters and half height. The hot water, which circulates in the exchangers, is provided by the hot-water tank of the electro-solar power station of the Center of Energy Researches and Technologies (CRTEn from Tunisia.

  8. Dynamics of drop formation of surfactant-containing liquids

    Science.gov (United States)

    Janakiram Subramani, Hariprasad

    2005-11-01

    Surfactants are used to control the breakup of jets and drops in applications as diverse as inkjet printing, pesticide spraying, and DNA microarraying. While the breakup of surfactant-free jets/drops has been exhaustively studied, little is known by comparison about interface rupture when the jet/drop liquids contain surfactants. High speed imaging is employed here to gain insights into differences between the dynamics of formation of drops of pure liquids, such as water, diethylene glycol, a 50 wt % solution of 20 cSt and 50 cSt polydimethyl siloxane, and those of solutions consisting of different concentrations of a nonionic surfactant, pentaethylene glycol monododecyl ether C12E5 in mixtures of 75 wt % (GW75) and 90 wt % (GW90) glycerol/water, from a capillary tube. Equilibrium surface tensions of solutions of C12E5 are fitted with the Langmuir-Szyskowski equation and the critical micelle concentrations (cmc) are found to be 0.25 and 0.40 mM. Changes in dynamics of drop breakup are studied by varying surfactant concentration (below and above cmc), flow rate, tube radius, and liquid viscosity.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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

  14. 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

  15. Geiger-Muller tubes

    International Nuclear Information System (INIS)

    A Geiger-Muller tube designed for use in an environment (for example, mounted on a rock drill) where subjected to mechanical shock and vibration has a tensioned anode wire secured by welding to securement members between first and second mounts at opposite ends of the tube envelope. The wire tension is adjusted to a high value with a screwable-adjustment means which is locked eg. by a spot-weld or by a locking nut, in the adjusted position, so that the natural frequency of the vibration of the tensioned wire does not resonate with (and may be much higher than) the frequencies to which the tube is subjected in use. The wire frequency is typically in excess of 400Hz and even 500Hz. The adjustment means may be included in the mount via which the envelope is evacuated and back-filled with the ionizible gas, and a gas-tight seal can be provided around this part of the mount, for example by sealing off the gas pump tube. However the adjustment means may be designed into another part of the tube, for example using telescopic parts of the envelope whose sliding junction is made gas tight with a flexible seal. (author)

  16. Categorising YouTube

    Directory of Open Access Journals (Sweden)

    Thomas Mosebo Simonsen

    2011-09-01

    Full Text Available This article provides a genre analytical approach to creating a typology of the User Generated Content (UGC of YouTube. The article investigates the construction of navigationprocesses on the YouTube website. It suggests a pragmatic genre approach that is expanded through a focus on YouTube’s technological affordances. Through an analysis of the different pragmatic contexts of YouTube, it is argued that a taxonomic understanding of YouTube must be analysed in regards to the vacillation of a user-driven bottom-up folksonomy and a hierarchical browsing system that emphasises a culture of competition and which favours the already popular content of YouTube. With this taxonomic approach, the UGC videos are registered and analysed in terms of empirically based observations. The article identifies various UGC categories and their principal characteristics. Furthermore, general tendencies of the UGC within the interacting relationship of new and old genres are discussed. It is argued that the utility of a conventional categorical system is primarily of analytical and theoretical interest rather than as a practical instrument.

  17. Effect of tube size on electromagnetic tube bulging

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The commercial finite code ANSYS was employed for the simulation of the electromagnetic tube bulging process. The finite element model and boundary conditions were thoroughly discussed. ANSYS/EMAG was used to model the time varying electromagnetic field in order to obtain the radial and axial magnetic pressure acting on the tube. The magnetic pressure was then used as boundary conditions to model the high velocity deformation of various length tube with ANSYS/LSDYNA. The time space distribution of magnetic pressure on various length tubes was presented. Effect of tube size on the distribution of radial magnetic pressure and axial magnetic pressure and high velocity deformation were discussed. According to the radial magnetic pressure ratio of tube end to tube center and corresponding dimensionless length ratio of tube to coil, the free electromagnetic tube bulging was studied in classification. The calculated results show good agreements with practice.

  18. 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

  19. 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

  20. 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.

  1. Model and Simulation of a Tunable Birefringent Fiber Using Capillaries Filled with Liquid Ethanol for Magnetic Quasiphase Matching In-Fiber Isolator

    Directory of Open Access Journals (Sweden)

    Clint Zeringue

    2010-01-01

    Full Text Available A technique to tune a magnetic quasi-phase matching in-fiber isolator through the application of stress induced by two mutually orthogonal capillary tubes filled with liquid ethanol is investigated numerically. The results show that it is possible to “tune” the birefringence in these fibers over a limited range depending on the temperature at which the ethanol is loaded into the capillaries. Over this tuning range, the thermal sensitivity of the birefringence is an order-of-magnitude lower than conventional fibers, making this technique well suited for magnetic quasi-phase matching.

  2. EBR-II Superheater Duplex Tube Examination

    International Nuclear Information System (INIS)

    After 30 years of operation, the Experimental Breeder Reactor II (EBR-II) Superheater 710 at Argonne National Laboratory-West (now Idaho National Laboratory) was decommissioned. As part of its post-service examination, four duplex tube sections were removed and Charpy impact testing was performed to characterize the crack arresting ability of nickel-bonded tube interfaces. Scanning electron microscopy (SEM) examination was also performed to characterize and identify changes in bond material microstructure. From room temperature to 400 degrees C, all samples demonstrated ductility and crack-stopping ability similar to that exhibited by beginning-of-life samples. However, at low temperature (-5 degrees C), samples removed from the lower region of the superheater (near the sodium inlet) failed while those from the upper region (near the sodium outlet) did not. SEM analysis revealed that all the tube-tube interfaces showed evidence of iron diffusion into the nickel braze, which resulted in the formation of a multiphase diffusion structure. Yet, significant void formation was only observed in the bond layer of the tubes removed from the lower region. This may be due to a change in the crystal microstructure of one of the phases within the bond layer that occurs in the 350 to 450 degrees C temperature range, which results in a lower density and the formation of porosity. Apparently, only the samples from the higher temperature region were exposed to this transition temperature, and the resulting large voids that developed acted as stress concentrators that led to low-temperature embrittlement and failure of the Charpy impact specimens

  3. 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.

  4. Kajian Efektifitas Sistem Struktur Tube Dengan Sistem Struktur Tube In Tube Di Bawah Beban Gempa

    OpenAIRE

    Sihotang, Dian Frisca

    2010-01-01

    Berkembangnya teknologi telah melahirkan berbagai sistem struktur bangunan tahan gempa, seperti penggunaan sistem tube.Tube adalah merupakan frame penahan gaya yang menahan gaya gaya lateral dengan struktur kantilever kotak yang memiliki jarak kolom yang berdekatan yang dipasang pada sekeliling gedung, sehingga penampilan wajah depan gedung seperti lubang jendela jendela yang terbuka. Rancangan tube ini kemudian dimodifikasi lagi dengan menambah pengaku pada bagian dalam ( konsep tube in tube...

  5. Neural tube defects

    OpenAIRE

    M.E. Marshall

    1981-01-01

    Neural tube defects refer to any defect in the morphogenesis of the neural tube, the most common types being spina bifida and anencephaly. Spina bifida has been recognised in skeletons found in north-eastern Morocco and estimated to have an age of almost 12 000 years. It was also known to the ancient Greek and Arabian physicians who thought that the bony defect was due to the tumour. The term spina bifida was first used by Professor Nicolai Tulp of Amsterdam in 1652. Many other terms have bee...

  6. Application of capillary fluid management techniques to the design of a phase separating microgravity bioreactor

    Science.gov (United States)

    Finger, Barry W.; Neville, Gale E., Jr.; Sager, John C.

    1993-01-01

    Manned space missions require the development of compact, efficient, and reliable life support systems. A number of aqueous biological conversion processes are associated with bioregenerative life support systems. Vessels, or bioreactors, capable of supporting these processes in microgravity must be developed. An annular flow bioreactor has been conceived. It has the potential to incorporate containment, phase separation, gas exchange, and illumination into a single vessel. The bioreactor utilizes capillary fluid management techniques and is configured as a cylindrical tube in which a two-phase liquid-gas flow is maintained. Vanes placed around the inner perimeter enhance capillary forces and cause the liquid phase to attach and flow along the interior surface of the tube. No physical barrier is required to complete phase separation. It is shown analytically that liquid film thickness is limited only by vane geometry and that an annular flow bioreactor capable of managing 284 liters would occupy 0.7 cubic m, less than half the volume of a Spacelab experiment rack.

  7. Study of capillary network directionality and irrigation of hypoxic tissue in an angiogenesis lattice model

    Science.gov (United States)

    Moglia, Belén; Guisoni, Nara; Albano, Ezequiel V.

    2013-12-01

    To shed light on the understanding of the angiogenesis process, we study a simplified lattice model for the capillary network formation between an existing blood vessel and an initially hypoxic tissue. We consider that the cells of the tissue surface can release growth factors that will diffuse, leading to the formation of new capillaries that ultimately arrive at the tissue. Additionally, we consider the local production of growth factors by the growing capillary network. We also propose the existence of an inhibition mechanism at the hypoxic surface, i.e., a fixed number of neighboring sites of an already irrigated site of the hypoxic tissue stop releasing growth factors due to the arrival of nutrients. Particularly, the goal of this work is to study the effect of the release of local growth factors and the inhibition mechanism on properties such as the directionality of the growing network and the irrigation of the hypoxic tissue. Therefore we propose the quantification of these two relevant features for angiogenesis modeling. We establish a relationship between the model behavior without the release of local growth factors in the presence of the inhibition mechanism and a normal angiogenesis process. In this situation, the model gives a directional capillary network and a good irrigation of the hypoxic tissue. On the other hand, for a large number of released local growth factors in the absence of the inhibition mechanism, the model could be appropriate for the description of tumor angiogenesis. In this case, the model provides a rather small directionality for the growing structure, with a worse degree of irrigation of the hypoxic tissue, as well as a more tortuous capillary network with many closed branches and loops.

  8. 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.

  9. Prawns in Bamboo Tube

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Ingredients: 400 grams Jiwei prawns, 25 grams pork shreds, 5 grams sliced garlic. Condiments: 5 grams cooking oil, minced ginger root and scallions, cooking wine, salt, pepper and MSG (optional) Method: 1. Place the Shelled prawns into a bowl and mix with all the condiments. 2. Stuff the prawns into a fresh bamboo tube,

  10. Thoughts of accelerator tubes

    International Nuclear Information System (INIS)

    A brief, subjective review is given of mechanisms that may be limiting electrostatic accelerator tubes to present levels of performance. Suggestions are made for attacking these limitations with the purpose of stimulating the thinking of designers and users of electrostatic accelerators

  11. 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)

  12. Determination of aflatoxins in food samples by automated on-line in-tube solid-phase microextraction coupled with liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Nonaka, Y; Saito, K; Hanioka, N; Narimatsu, S; Kataoka, H

    2009-05-15

    A simple and sensitive automated method for determination of aflatoxins (B1, B2, G1, and G2) in nuts, cereals, dried fruits, and spices was developed consisting of in-tube solid-phase microextraction (SPME) coupled with liquid chromatography-mass spectrometry (LC-MS). Aflatoxins were separated within 8 min by high-performance liquid chromatography using a Zorbax Eclipse XDB-C8 column with methanol/acetonitrile (60/40, v/v): 5mM ammonium formate (45:55) as the mobile phase. Electrospray ionization conditions in the positive ion mode were optimized for MS detection of aflatoxins. The pseudo-molecular ions [M+H](+) were used to detect aflatoxins in selected ion monitoring (SIM) mode. The optimum in-tube SPME conditions were 25draw/eject cycles of 40 microL of sample using a Supel-Q PLOT capillary column as an extraction device. The extracted aflatoxins were readily desorbed from the capillary by passage of the mobile phase, and no carryover was observed. Using the in-tube SPME LC-MS with SIM method, good linearity of the calibration curve (r>0.9994) was obtained in the concentration range of 0.05-2.0 ng/mL using aflatoxin M1 as an internal standard, and the detection limits (S/N=3) of aflatoxins were 2.1-2.8 pg/mL. The in-tube SPME method showed >23-fold higher sensitivity than the direct injection method (10 microL injection volume). The within-day and between-day precision (relative standard deviations) at the concentration of 1 ng/mL aflatoxin mixture were below 3.3% and 7.7% (n=5), respectively. This method was applied successfully to analysis of food samples without interference peaks. The recoveries of aflatoxins spiked into nuts and cereals were >80%, and the relative standard deviations were Aflatoxins were detected at <10 ng/g in several commercial food samples. PMID:19328492

  13. An air-pressure-free elastomeric valve for integrated nucleic acid analysis by capillary electrophoresis

    Science.gov (United States)

    Jung, Wooseok; Barrett, Matthew; Brooks, Carla; Rivera, Andrew; Birdsell, Dawn N.; Wagner, David M.; Zenhausern, Frederic

    2015-12-01

    We present a new elastomeric valve for integrated nucleic acid analysis by capillary electrophoresis. The valve functions include metering to capture a designated volume of biological sample into a polymerase chain reaction (PCR) chamber, sealing to preserve the sample during PCR cycling, and transfer of the PCR-products and on-chip formamide post-processing for the analysis of DNA fragments by capillary gel electrophoresis. This new valve differs from prior art polydimethylsiloxane (PDMS) valves in that the valve is not actuated externally by air-pressure or vacuum so that it simplifies a DNA analysis system by eliminating the need for an air-pressure or vacuum source, and off-cartridge solenoid valves, control circuit boards and software. Instead, the new valve is actuated by a thermal cycling peltier assembly integrated within the hardware instrument that tightly comes in contact with a microfluidic cartridge for thermal activation during PCR, so that it spontaneously closes the valve without an additional actuator system. The valve has bumps in the designated locations so that it has a self-alignment that does not require precise alignment of a valve actuator. Moreover, the thickness of the new valve is around 600 μm with an additional bump height of 400 μm so that it is easy to handle and very feasible to fabricate by injection molding compared to other PDMS valves whose thicknesses are around 30-100 μm. The new valve provided over 95% of metering performance in filling the fixed volume of the PCR chamber, preserved over 97% of the sample volume during PCR, and showed very comparable capillary electrophoresis peak heights to the benchtop assay tube controls with very consistent transfer volume of the PCR-product and on-chip formamide. The new valve can perform a core function for integrated nucleic acid analysis by capillary electrophoresis.

  14. An air-pressure-free elastomeric valve for integrated nucleic acid analysis by capillary electrophoresis

    International Nuclear Information System (INIS)

    We present a new elastomeric valve for integrated nucleic acid analysis by capillary electrophoresis. The valve functions include metering to capture a designated volume of biological sample into a polymerase chain reaction (PCR) chamber, sealing to preserve the sample during PCR cycling, and transfer of the PCR-products and on-chip formamide post-processing for the analysis of DNA fragments by capillary gel electrophoresis. This new valve differs from prior art polydimethylsiloxane (PDMS) valves in that the valve is not actuated externally by air-pressure or vacuum so that it simplifies a DNA analysis system by eliminating the need for an air-pressure or vacuum source, and off-cartridge solenoid valves, control circuit boards and software. Instead, the new valve is actuated by a thermal cycling peltier assembly integrated within the hardware instrument that tightly comes in contact with a microfluidic cartridge for thermal activation during PCR, so that it spontaneously closes the valve without an additional actuator system. The valve has bumps in the designated locations so that it has a self-alignment that does not require precise alignment of a valve actuator. Moreover, the thickness of the new valve is around 600 μm with an additional bump height of 400 μm so that it is easy to handle and very feasible to fabricate by injection molding compared to other PDMS valves whose thicknesses are around 30–100 μm. The new valve provided over 95% of metering performance in filling the fixed volume of the PCR chamber, preserved over 97% of the sample volume during PCR, and showed very comparable capillary electrophoresis peak heights to the benchtop assay tube controls with very consistent transfer volume of the PCR-product and on-chip formamide. The new valve can perform a core function for integrated nucleic acid analysis by capillary electrophoresis. (paper)

  15. A capillary-based perfusion phantom for simulation of brain perfusion for MRI

    International Nuclear Information System (INIS)

    Purpose: The measurement of the CBF is a non-standardized procedure and there are no reliable gold standards. This abstract shows a capillary-based perfusion-phantom for CE-DSC-MRI. It has equivalent flow properties to those within the tissue capillary system of the human brain and allows the validation of the Siemens Perfusion (MR) software. Materials and Methods: The perfusion phantom consists of a dialyzer for the simulation of the capillary system, a feeding tube for simulation of the AIF and a pulsatile pump for simulation of the heart. Using this perfusion phantom, the exact determination of the gold standard CBF due to the well-known geometry of the phantom is easy. It was validated based on different perfusion measurements. These measurements were investigated with standard software (Siemens Perfusion MR). The software determined the CBF within the capillary system. Based on this CBF, a comparison to the gold standard was made with several different flow speeds. After AIF selection, a total of 726 CBF data points were automatically extracted by the software. Results: This results in a comparison of the gold standard CBF to these 726 CBF values. Therefore, a reproducible and reliable deviation estimation between gold standard CBF and measured CBF using the software was computed. It can be shown that the deviation between gold standard and software-based evaluation ranges between 1 and 31 %. Conclusion: There is no significance for any correlation between flow speed and amount of deviation. The mean measured CBF is 11.4 % higher than the gold standard CBF (p-value < 0.001). Using this kind of perfusion-phantom, the validation of different software systems allows reliable conclusions about their quality. (orig.)

  16. The influence of van der Waals interactions on a bubble moving in a tube

    OpenAIRE

    Hammoud, Naima; Trinh, Philippe H.; Howell, Peter D.; Stone, Howard A.

    2016-01-01

    We consider the unsteady thin-film dynamics of a long bubble of negligible viscosity that advances at a uniform speed in a cylindrical capillary tube. The bubble displaces a viscous non-wetting fluid, creating a thin film between its interface and the tube walls. The film is considered thin enough that intermolecular forces in the form of van der Waals attractions are significant and thin-film rupture is possible. In the absence of intermolecular forces, the bubble has a steady-state where a ...

  17. Encapsulation of Viscous Foods in Agar Gel Tubes for Electron Microscopy

    OpenAIRE

    Kalab, Miloslav

    1988-01-01

    Viscous food is aspirated into a glass capillary tube with the inner diameter of approximately 0.5 mm if the food is to be examined by transmission electron microscopy. If the sample is destined for examination by scanning electron microscopy, it is aspirated into a Pasteur pipette having the diameter of 1.0 mm. In each case, the lower end of the glass tube is sealed with a droplet of 40°C warm 3% agar sol. After the sol solidifies, the pipette is dipped in the same agar sol and a coating, 0....

  18. Determination of synthetic dyes in food products by capillary zone electrophoresis in a hydrodynamically closed separation compartment.

    Science.gov (United States)

    Masár, M; Kaniansky, D

    1996-01-01

    The application of capillary zone electrophoresis (CZE) in a hydrodynamically closed separation system to determine synthetic food colorants added to food products was investigated. The CZE separations were carried out in a 300-micron-i.d. capillary tube made of fluorinated ethylene-propylene copolymer. The inner diameter of the capillary tube made it possible to enhance sample loads (100-nL injection volumes) so that 10-300 ppb limits of detection (LOD) values could be achieved for the studied dyes by a photometric absorbance detector operating at a 254-nm detection wave-length. With the exception of erythrosine (which exhibited a residual adsorption), very good reproducibilities of the determination were typical for 4- and 32-ppm concentrations of the dyes. This rapid CZE procedure (migration times of the resolved analytes were between 2.5 and 10.5 min) provided good selectivities in the determination of the dyes in various food matrices (soft drink concentrates, liqueurs, and chewing gums). Simple sample preparation steps were effective for the sample matrices used in the investigation. PMID:9384749

  19. Growth of ZnO nanolayers inside the capillaries of photonic crystal fibres

    CERN Document Server

    Konidakis, I; Zito, G; Pissadakis, S

    2013-01-01

    In this study, we describe the formation of ZnO nanolayers inside the air capillaries of a silica photonic crystal fibre (PCF), targeting random laser and organic vapor sensing applications. ZnO nanolayers were developed by infiltrating the capillaries of the silica PCF with Zn-acetate/methanol solutions of various concentrations, followed by annealing treatments. The growth and morphology of the synthesized ZnO nanolayers were characterized by means of scanning electron microscopy (SEM) and found to be affected by the concentration of the Zn-acetate/methanol infiltration solution. For low concentrations, inspection with SEM revealed the formation of 25 and 100-nm-thick ZnO nanolayers across the entire length of the infiltrated capillaries, whereas increasing the Zn-acetate concentration resulted to the formation of randomly placed isolated ZnO nanorods. Room temperature photoluminescence spectra of the ZnO nanolayers inside the PCF were measured and compared with the corresponding spectra reported for ZnO st...

  20. Cosmic R-string, R-tube and vacuum instability

    Energy Technology Data Exchange (ETDEWEB)

    Eto, Minoru [Yamagata Univ. (Japan). Dept. of Physics; Hamada, Yuta; Kobayashi, Tatsuo [Kyoto Univ. (Japan). Dept. of Physics; Kamada, Kohei [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Ohashi, Keisuke [Osaka City Univ. (Japan). Dept. of Mathematics and Physics; Ookouchi, Yutaka [Kyoto Univ. (Japan). Dept. of Physics; Kyoto Univ. (Japan). The Hakubi Center for Advanced Research

    2012-11-15

    We show that a cosmic string associated with spontaneous U(1) R symmetry breaking gives a constraint for supersymmetric model building. In some models, the string can be viewed as a tube-like domain wall with a winding number interpolating a false vacuum and a true vacuum. Such string causes inhomogeneous decay of the false vacuum to the true vacuum via rapid expansion of the radius of the tube and hence its formation would be inconsistent with the present Universe. However, we demonstrate that there exist metastable solutions which do not expand rapidly. Furthermore, when the true vacua are degenerate, the structure inside the tube becomes involved. As an example, we show a ''bamboo''-like solution, which suggests a possibility observing an information of true vacua from outside of the tube through the shape and the tension of the tube.

  1. Cosmic R-string, R-tube and vacuum instability

    International Nuclear Information System (INIS)

    We show that a cosmic string associated with spontaneous U(1) R symmetry breaking gives a constraint for supersymmetric model building. In some models, the string can be viewed as a tube-like domain wall with a winding number interpolating a false vacuum and a true vacuum. Such string causes inhomogeneous decay of the false vacuum to the true vacuum via rapid expansion of the radius of the tube and hence its formation would be inconsistent with the present Universe. However, we demonstrate that there exist metastable solutions which do not expand rapidly. Furthermore, when the true vacua are degenerate, the structure inside the tube becomes involved. As an example, we show a ''bamboo''-like solution, which suggests a possibility observing an information of true vacua from outside of the tube through the shape and the tension of the tube.

  2. Cosmic R-string, R-tube and vacuum instability

    Science.gov (United States)

    Eto, Minoru; Hamada, Yuta; Kamada, Kohei; Kobayashi, Tatsuo; Ohashi, Keisuke; Ookouchi, Yutaka

    2013-03-01

    We show that a cosmic string associated with spontaneous U(1) R symmetry breaking gives a constraint for supersymmetric model building. In some models, the string can be viewed as a tube-like domain wall with a winding number interpolating a false vacuum and a true vacuum. Such string causes inhomogeneous decay of the false vacuum to the true vacuum via rapid expansion of the radius of the tube and hence its formation would be inconsistent with the present Universe. However, we demonstrate that there exist metastable solutions which do not expand rapidly. Furthermore, when the true vacua are degenerate, the structure inside the tube becomes involved. As an example, we show a "bamboo"-like solution, which suggests a possibility observing an information of true vacua from outside of the tube through the shape and the tension of the tube.

  3. Cosmic R-string, R-tube and Vacuum Instability

    CERN Document Server

    Eto, Minoru; Kamada, Kohei; Kobayashi, Tatsuo; Ohashi, Keisuke; Ookouchi, Yutaka

    2012-01-01

    We show that a cosmic string associated with spontaneous $U(1)_R$ symmetry breaking gives a constraint for supersymmetric model building. In some models, the string can be viewed as a tube-like domain wall with a winding number interpolating a false vacuum and a true vacuum. Such string causes inhomogeneous decay of the false vacuum to the true vacuum via rapid expansion of the radius of the tube and hence its formation would be inconsistent with the present Universe. However, we demonstrate that there exist metastable solutions which do not expand rapidly. Furthermore, when the true vacua are degenerate, the structure inside the tube becomes involved. As an example, we show a "bamboo"-like solution, which suggests a possibility observing an information of true vacua from outside of the tube through the shape and the tension of the tube.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. Quarter-wave pulse tube

    Science.gov (United States)

    Swift, G. W.; Gardner, D. L.; Backhaus, S. N.

    2011-10-01

    In high-power pulse-tube refrigerators, the pulse tube itself can be very long without too much dissipation of acoustic power on its walls. The pressure amplitude, the volume-flow-rate amplitude, and the time phase between them evolve significantly along a pulse tube that is about a quarter-wavelength long. Proper choice of length and area makes the oscillations at the ambient end of the long pulse tube optimal for driving a second, smaller pulse-tube refrigerator, thereby utilizing the acoustic power that would typically have been dissipated in the first pulse-tube refrigerator's orifice. Experiments show that little heat is carried from the ambient heat exchanger to the cold heat exchanger in such a long pulse tube, even though the oscillations are turbulent and even when the tube is compactly coiled.

  11. Drift tubes of Linac 2

    CERN Multimedia

    Photographic Service

    1977-01-01

    Being redied for installation, those at the right are for tank 1, those on the left for tank 2. Contrary to Linac 1, which had drift-tubes supported on stems, here the tubes are suspended, for better mechanical stability.

  12. Laser welding of a tube

    International Nuclear Information System (INIS)

    For sleeving PWR steam generator tubes, the welding laser work is made under protection of a primary gas going out by the crossing window of the laser and under a secondary gas flowing axially through the head and the tube

  13. Tubing For Sampling Hydrazine Vapor

    Science.gov (United States)

    Travis, Josh; Taffe, Patricia S.; Rose-Pehrsson, Susan L.; Wyatt, Jeffrey R.

    1993-01-01

    Report evaluates flexible tubing used for transporting such hypergolic vapors as those of hydrazines for quantitative analysis. Describes experiments in which variety of tubing materials, chosen for their known compatibility with hydrazine, flexibility, and resistance to heat.

  14. 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

  15. 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...

  16. 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.

  17. 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...

  18. 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...

  19. 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.

  20. 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...

  1. 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

  2. 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.

  3. 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.

  4. 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

  5. Ultrasonic nondestructive tubing inspection system

    International Nuclear Information System (INIS)

    A system for measuring the extent of tube wall erosion in an inspection region of a heat exchanger tube of a nuclear steam generator, uses an ultrasonic means driven helically inside the eroded tube which may be filled with a fluid (e.g., water) to minimize ultrasonic wave attenuation. A control means cooperates with the ultrasonic means to produce a map of the tube wall thickness in an inspection region

  6. BcMF26a and BcMF26b Are Duplicated Polygalacturonase Genes with Divergent Expression Patterns and Functions in Pollen Development and Pollen Tube Formation in Brassica campestris.

    Science.gov (United States)

    Lyu, Meiling; Yu, Youjian; Jiang, Jingjing; Song, Limin; Liang, Ying; Ma, Zhiming; Xiong, Xingpeng; Cao, Jiashu

    2015-01-01

    Polygalacturonase (PG) is one of the cell wall hydrolytic enzymes involving in pectin degradation. A comparison of two highly conserved duplicated PG genes, namely, Brassica campestris Male Fertility 26a (BcMF26a) and BcMF26b, revealed the different features of their expression patterns and functions. We found that these two genes were orthologous genes of At4g33440, and they originated from a chromosomal segmental duplication. Although structurally similar, their regulatory and intron sequences largely diverged. QRT-PCR analysis showed that the expression level of BcMF26b was higher than that of BcMF26a in almost all the tested organs and tissues in Brassica campestris. Promoter activity analysis showed that, at reproductive development stages, BcMF26b promoter was active in tapetum, pollen grains, and pistils, whereas BcMF26a promoter was only active in pistils. In the subcellular localization experiment, BcMF26a and BcMF26b proteins could be localized to the cell wall. When the two genes were co-inhibited, pollen intine was formed abnormally and pollen tubes could not grow or stretch. Moreover, the knockout mutants of At4g33440 delayed the growth of pollen tubes. Therefore, BcMF26a/b can participate in the construction of pollen wall by modulating intine information and BcMF26b may play a major role in co-inhibiting transformed plants. PMID:26153985

  7. BcMF26a and BcMF26b Are Duplicated Polygalacturonase Genes with Divergent Expression Patterns and Functions in Pollen Development and Pollen Tube Formation in Brassica campestris.

    Directory of Open Access Journals (Sweden)

    Meiling Lyu

    Full Text Available Polygalacturonase (PG is one of the cell wall hydrolytic enzymes involving in pectin degradation. A comparison of two highly conserved duplicated PG genes, namely, Brassica campestris Male Fertility 26a (BcMF26a and BcMF26b, revealed the different features of their expression patterns and functions. We found that these two genes were orthologous genes of At4g33440, and they originated from a chromosomal segmental duplication. Although structurally similar, their regulatory and intron sequences largely diverged. QRT-PCR analysis showed that the expression level of BcMF26b was higher than that of BcMF26a in almost all the tested organs and tissues in Brassica campestris. Promoter activity analysis showed that, at reproductive development stages, BcMF26b promoter was active in tapetum, pollen grains, and pistils, whereas BcMF26a promoter was only active in pistils. In the subcellular localization experiment, BcMF26a and BcMF26b proteins could be localized to the cell wall. When the two genes were co-inhibited, pollen intine was formed abnormally and pollen tubes could not grow or stretch. Moreover, the knockout mutants of At4g33440 delayed the growth of pollen tubes. Therefore, BcMF26a/b can participate in the construction of pollen wall by modulating intine information and BcMF26b may play a major role in co-inhibiting transformed plants.

  8. Polyether ether ketone encased monolith frits made of polyether ether ketone tubing with a 0.25 mm opening resulting in an improved separation performance in liquid chromatography.

    Science.gov (United States)

    Park, Sin Young; Cheong, Won Jo

    2016-05-01

    Tiny polyether ether ketone encased monolith frits have been prepared by modified catalytic sulfonation of the inner surface of polyether ether tubing (1.6 mm od, 0.25 mm id) followed by modified formation of organic monolith and cutting of the tubing into slices. The frit was placed below the central hole of the column outlet union and supported by a combination of a silica capillary (0.365 mm od, 0.05 mm id) and a polyether ether ketone sleeve (1.6 mm od, 0.38 mm id) tightened with a nut and a ferrule when the column was packed to prevent sinking of the frit element into the union hole (0.25 mm opening) otherwise. The column packed this way with the frits investigated in this study has shown better separation performance owing to the reduced frit volume in comparison to the column packed with a commercial stainless-steel screen frit. This study establishes the strategy of disposable microcolumns in which cheap disposable frits are used whenever the column is re-packed to yield columns of even better chromatographic performance than the columns with commercial frits. PMID:26910135

  9. Sleeve puller salvages welded tubes

    Science.gov (United States)

    Weaver, J. F.

    1980-01-01

    Tool removes sleeve remnants without distorting or damaging tubes, unlike pliers and other conventional handtools. Tubes can be reused, saving time, labor, and material in many applications. Sleeve-removal fixture consists of pressure screw, swing arm, locking screws, and base. It removes sleeve remnant from tubing after welded joint has been sawed through.

  10. Highly sensitive biosensing based on interference from light scattering in capillary tubes

    DEFF Research Database (Denmark)

    Sørensen, H.S.; Larsen, N.B.; Latham, J.C.;

    2006-01-01

    Human IgG interactions with surface bound protein A are monitored label-free using microinterferometric backscatter detection. An electromagnetic wave-based model is developed and used to quantitatively describe the change in interference pattern as a consequence of the molecular interaction with...

  11. Milk Collection in the Rat Using Capillary Tubes and Estimation of Milk Fat Content by Creamatocrit.

    Science.gov (United States)

    Paul, Heather A; Hallam, Megan C; Reimer, Raylene A

    2015-01-01

    Milk, as the sole source of nutrition for the newborn mammal, provides the necessary nutrients and energy for offspring growth and development. It also contains a vast number of bioactive compounds that greatly affect the development of the neonate. The analysis of milk components will help elucidate key factors that link maternal metabolism and health with offspring growth and development. The laboratory rat represents a popular model organism for maternal studies, and rat milk can be used to examine the effect of various maternal physiological, nutritional, and pharmacological interventions on milk components, which may then impact offspring health. Here a simple method of manually collecting milk from the lactating rat that can be performed by a single investigator, does not require specialized vacuum or suction equipment, and provides sufficient milk for subsequent downstream analysis is described. A method for estimating the fat content of milk by measuring the percentage of cream within the milk sample, known as the creamatocrit, is also presented. These methods can ultimately be used to increase insight into maternal-child health and to elucidate maternal factors that are involved in proper growth and development of offspring. PMID:26709708

  12. Neural tube defects

    Directory of Open Access Journals (Sweden)

    M.E. Marshall

    1981-09-01

    Full Text Available Neural tube defects refer to any defect in the morphogenesis of the neural tube, the most common types being spina bifida and anencephaly. Spina bifida has been recognised in skeletons found in north-eastern Morocco and estimated to have an age of almost 12 000 years. It was also known to the ancient Greek and Arabian physicians who thought that the bony defect was due to the tumour. The term spina bifida was first used by Professor Nicolai Tulp of Amsterdam in 1652. Many other terms have been used to describe this defect, but spina bifida remains the most useful general term, as it describes the separation of the vertebral elements in the midline.

  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. Elongation, proliferation & migration differentiate endothelial cell phenotypes and determine capillary sprouting

    Directory of Open Access Journals (Sweden)

    Popel Aleksander S

    2009-01-01

    Full Text Available Abstract Background Angiogenesis, the growth of capillaries from preexisting blood vessels, has been extensively studied experimentally over the past thirty years. Molecular insights from these studies have lead to therapies for cancer, macular degeneration and ischemia. In parallel, mathematical models of angiogenesis have helped characterize a broader view of capillary network formation and have suggested new directions for experimental pursuit. We developed a computational model that bridges the gap between these two perspectives, and addresses a remaining question in angiogenic sprouting: how do the processes of endothelial cell elongation, migration and proliferation contribute to vessel formation? Results We present a multiscale systems model that closely simulates the mechanisms underlying sprouting at the onset of angiogenesis. Designed by agent-based programming, the model uses logical rules to guide the behavior of individual endothelial cells and segments of cells. The activation, proliferation, and movement of these cells lead to capillary growth in three dimensions. By this means, a novel capillary network emerges out of combinatorially complex interactions of single cells. Rules and parameter ranges are based on literature data on endothelial cell behavior in vitro. The model is designed generally, and will subsequently be applied to represent species-specific, tissue-specific in vitro and in vivo conditions. Initial results predict tip cell activation, stalk cell development and sprout formation as a function of local vascular endothelial growth factor concentrations and the Delta-like 4 Notch ligand, as it might occur in a three-dimensional in vitro setting. Results demonstrate the differential effects of ligand concentrations, cell movement and proliferation on sprouting and directional persistence. Conclusion This systems biology model offers a paradigm closely related to biological phenomena and highlights previously

  15. X-ray tubes

    International Nuclear Information System (INIS)

    An improved form of x-ray tube is described which consists of a rotatable anode disc and an electron beam source enclosed in an envelope. The beam of electrons strikes the edge of the anode disc at an acute angle, producing x-rays which are transmitted through a window in the envelope. To improve performance and life of the anode disc it is additionally reciprocated back and forth along its axis of rotation. Dimensions are specified. (U.K.)

  16. Primary fallopian tube carcinoma

    Directory of Open Access Journals (Sweden)

    Mladenović-Segedi Ljiljana

    2009-01-01

    Full Text Available Introduction. Primary fallopian tube carcinoma is extremely rare, making 0.3-1.6% of all female genital tract malignancies. Although the etymology of this tumor is unknown, it is suggested to be associated with chronic tubal inflammation, infertility, tuberculous salpingitis and tubal endometriosis. High parity is considered to be protective. Cytogenetic studies show the disease to be associated with over expression of p53, HER2/neu and c-myb. There is also some evidence that BRCA1 and BRCA2 mutations have a role in umorogeneis. Clinical features. The most prevailing symptoms with fallopian tube carcinoma are abdominal pain, abnormal vaginal discharge/bleeding and the most common finding is an adnexal mass. In many patients, fallopian tube carcinoma is asymptomatic. Diagnosis. Due to its rarity, preoperative diagnosis of primary fallopian tube carcinoma is rarely made. It is usually misdiagnosed as ovarian carcinoma, tuboovarian abscess or ectopic pregnancy. Sonographic features of the tumor are non-specific and include the presence of a fluid-filled adnexal structure with a significant solid component, a sausage-shaped mass, a cystic mass with papillary projections within, a cystic mass with cog wheel appearance and an ovoid-shaped structure containing an incomplete separation and a highly vascular solid nodule. More than 80% of patients have elevated pretreatment serum CA-125 levels, which is useful in follow-up after the definite treatment. Treatment. The treatment approach is similar to that of ovarian carcinoma, and includes total abdominal hysterectomy and bilateral salpingo-oophorectomy. Staging is followed with chemotherapy.

  17. Whacked and Rab35 polarize dynein-motor-complex-dependent seamless tube growth.

    Science.gov (United States)

    Schottenfeld-Roames, Jodi; Ghabrial, Amin S

    2012-04-01

    Seamless tubes form intracellularly without cell-cell or autocellular junctions. Such tubes have been described across phyla, but remain mysterious despite their simple architecture. In Drosophila, seamless tubes are found within tracheal terminal cells, which have dozens of branched protrusions extending hundreds of micrometres. We find that mutations in multiple components of the dynein motor complex block seamless tube growth, raising the possibility that the lumenal membrane forms through minus-end-directed transport of apical membrane components along microtubules. Growth of seamless tubes is polarized along the proximodistal axis by Rab35 and its apical membrane-localized GAP, Whacked. Strikingly, loss of whacked (or constitutive activation of Rab35) leads to tube overgrowth at terminal cell branch tips, whereas overexpression of Whacked (or dominant-negative Rab35) causes formation of ectopic tubes surrounding the terminal cell nucleus. Thus, vesicle trafficking has key roles in making and shaping seamless tubes. PMID:22407366

  18. Fabrication of seamless calandria tubes

    International Nuclear Information System (INIS)

    Full text: Calandria tube is a large diameter, thin walled zircaloy-4 tube and is an important structural component of PHWR type of reactors. These tubes are lifetime components and remain during the full life of the reactor. Calandria tubes are classified as extremely thin walled tubes with a diameter to wall thickness ratio of around 96. Such thin walled tubes are conventionally produced by seam welded route comprising of extrusion of slabs followed by a series of hot and rolling passes, shaping into O-shape and eventual welding. An alternative and superior method of fabricating the calandria tubes, the seamless route, has been developed, which involves hot extrusion of mother blanks followed by three successive cold pilger reductions. Eccentricity correction of the extruded blanks is carried out on a special purpose grinding equipment to bring the wall thickness variation within permissible limits. Predominant wall thickness reductions are given during cold pilgering to ensure high Q-factor values. The texture in the finished tubes could be closely, controlled with an average fr value of 0.65. Pilgering parameters and tube guiding system have been specially designed to facilities rolling of thin walled tubes. Seamless calandria tubes have distinct advantages over welded tubes. In addition to the absence of weld, they are dimensionally more stable, lighter in weight and possess uniform grains with superior grain size. The cycle time from billet to finished product is substantially reduced and the product is amenable to high level of quality assurance. The most significant feature of the seamless route is its material recovery over welded route. Residual stresses measured in the tubes indicate that these are negligible and uniform along the length of the tube. In view of their superior quality, the first charge of seamless calandria tubes will be rolled into the first 500 MWe Pressurised Heavy Water Reactor at Tarapur

  19. CFD simulation of the gas flow in a pulse tube cryocooler with two pulse tubes

    Science.gov (United States)

    Yin, C. L.

    2015-12-01

    In this paper, in order to instruct the next optimization work, a two-dimension Computational Fluid Dynamics (CFD) model is developed to simulate temperature distribution and velocity distribution of oscillating fluid in the DPTC by individual phase-shifting. It is found that the axial temperature distribution of regenerator is generally uniform and the temperatures near the center at the same cross setion of two pulse tubes are obviously higher than their near wall temperatures. The wall temperature difference about 0-7 K exists between the two pulse tubes. The velocity distribution near the center of the regenerator is uniform and there is obvious injection stream coming at the center of the pulse tubes from the hot end. The formation reason of temperature distribution and velocity distribution is explained.

  20. Clogging of feeding tubes.

    Science.gov (United States)

    Marcuard, S P; Perkins, A M

    1988-01-01

    This is a report of an in vitro study evaluating clotting ability of some formulas with intact protein and hydrolyzed protein sources in a series of buffers ranging from a pH of 1 thru 10. The following 10 products were tested: Ensure Plus, Ensure, Enrich, Osmolite, Pulmocare, Citrotein, Resource, Vivonex TEN, Vital, and Hepatic Acid II. Protein (10 and 20 g/liter) was added to Citrotein and Ensure Plus. All formulas were tested at full and some at half strength. Clotting occurred only in premixed intact protein formulas (Pulmocare, Ensure Plus, Osmolite, Enrich, Ensure) and in Resource. No clotting was observed for Citrotein (intact protein formula in powder form), Vital, Vivonex TEN, and Hepatic Aid II. Adding protein did not cause or increase clotting. In summary, clotting of some liquid formula diet appears to be an important factor causing possible gastric feeding tube occlusion. The following measures may help in preventing this problem: flushing before and after aspirating for gastric residuals to eliminate acid precipitation of formula in the feeding tube, advance the nasogastric feeding tube into the duodenum if possible, and avoid mixing these products with liquid medications having a pH value of 5.0 or less. PMID:3138452

  1. Traveling-Wave Tubes

    Science.gov (United States)

    Kory, Carol L.

    1998-01-01

    The traveling-wave tube (TWT) is a vacuum device invented in the early 1940's used for amplification at microwave frequencies. Amplification is attained by surrendering kinetic energy from an electron beam to a radio frequency (RF) electromagnetic wave. The demand for vacuum devices has been decreased largely by the advent of solid-state devices. However, although solid state devices have replaced vacuum devices in many areas, there are still many applications such as radar, electronic countermeasures and satellite communications, that require operating characteristics such as high power (Watts to Megawatts), high frequency (below 1 GHz to over 100 GHz) and large bandwidth that only vacuum devices can provide. Vacuum devices are also deemed irreplaceable in the music industry where musicians treasure their tube-based amplifiers claiming that the solid-state and digital counterparts could never provide the same "warmth" (3). The term traveling-wave tube includes both fast-wave and slow-wave devices. This article will concentrate on slow-wave devices as the vast majority of TWTs in operation fall into this category.

  2. CRL X-RAY TUBE

    OpenAIRE

    Kolchevsky, N. N.; Petrov, P. V.

    2015-01-01

    A novel types of X-ray tubes with refractive lenses are proposed. CRL-R X-ray tube consists of Compound Refractive Lens- CRL and Reflection X-ray tube. CRL acts as X-ray window. CRL-T X-ray consists of CRL and Transmission X-ray tube. CRL acts as target for electron beam. CRL refractive lens acts as filter, collimator, waveguide and focusing lens. Properties and construction of the CRL X-ray tube are discussed.

  3. Spectrometer beam tube dimensional optimization

    International Nuclear Information System (INIS)

    This project examined the optimization of the design of a beam tube. An ANSYS model was used to find the minimum tube thickness and the best camber in a beam tube under vacuum and preloaded by a pair of magnet poles. After the tube was modeled one version of it was built for use in the accelerator. This beam tube was put under a vacuum and the dimensional changes were recorded and compared to the ANSYS predictions. These deflection results were quite close to the predicted numbers and would suggest that the stresses are similar to the predictions as well

  4. 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

  5. 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.

  6. Reliability of steam generator tubing

    Energy Technology Data Exchange (ETDEWEB)

    Kadokami, E. [Mitsubishi Heavy Industries Ltd., Hyogo-ku (Japan)

    1997-02-01

    The author presents results on studies made of the reliability of steam generator (SG) tubing. The basis for this work is that in Japan the issue of defects in SG tubing is addressed by the approach that any detected defect should be repaired, either by plugging the tube or sleeving it. However, this leaves open the issue that there is a detection limit in practice, and what is the effect of nondetectable cracks on the performance of tubing. These studies were commissioned to look at the safety issues involved in degraded SG tubing. The program has looked at a number of different issues. First was an assessment of the penetration and opening behavior of tube flaws due to internal pressure in the tubing. They have studied: penetration behavior of the tube flaws; primary water leakage from through-wall flaws; opening behavior of through-wall flaws. In addition they have looked at the question of the reliability of tubing with flaws during normal plant operation. Also there have been studies done on the consequences of tube rupture accidents on the integrity of neighboring tubes.

  7. Microdischarges in DC accelerator tubes

    International Nuclear Information System (INIS)

    Voltage tests on the Daresbury ceramic/titanium accelerator tube have shown that microdischarges play an important role in the conditioning process. It has been found that the voltage onset for microdischarges in a tube is dependent on the surface contamination of the electrodes and the tube geometry (in particular the tube length). This geometrical effect can be related to the trajectories of secondary ions emitted from the electrode surfaces. Sensitive diagnostic techniques have been developed to study the mass and energy distribution of ions emitted along the axis of the tube during these predischarges. The energy distribution of protons (and H- ions) can be related to the origins of the discharges in the tube. Detailed results are presented for a particular tube geometry. (author)

  8. Drop size selection in axially heated co-axial fiber capillary instability

    Science.gov (United States)

    Mowlavi, Saviz; Brun, Pierre-Thomas; Gallaire, Francois

    2015-11-01

    We analyze the sphere size selection mechanism in silicon-in-silica sphere formation through the application of an external axial thermal gradient to a co-axial silicon-in-silica fiber (Gumennik et al., Nature Com., 2013). We first apply a convective/absolute stability analysis to the in-fibre capillary instability governing the sphere formation and demonstrate that the resulting wavelength selection predicts a finite but still too large wavelength. A global stability analysis is then pursued, which accounts for the spatial inhomogeneity of the base flow. F.G. acknowledges funding from ERC SimCoMiCs 280117.

  9. Seamless tube shape is constrained by endocytosis-dependent regulation of active Moesin

    OpenAIRE

    Schottenfeld-Roames, Jodi; Rosa, Jeffrey B.; Ghabrial, Amin S.

    2014-01-01

    Most tubes have “seams” – intercellular or autocellular junctions that seal membranes together into a tube – but “seamless” tubes also exist [1-3]. In Drosophila, stellate-shaped tracheal terminal cells make seamless tubes, with single branches running through each of dozens of cellular extensions. We find that mutations in braided impair terminal cell branching and cause formation of seamless tube cysts. We show that braided encodes Syntaxin7, and that cysts also form in cells deficient for ...

  10. 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...

  11. 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.

  12. 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...

  13. 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 ...

  14. Ultrasonic inspection of tube to tube plate welds

    International Nuclear Information System (INIS)

    To monitor the deterioration of a weld between a tube and tube plate which has been repaired by a repair sleeve inside the tube and brazed at one end to the tube, ultrasound from a crystal at the end of a rod is launched, in the form of Lamb-type waves, into the tube through the braze and allowed to travel along the tube to the weld and be reflected back along the tube. The technique may also be used for the type of heat exchanger in which, during construction, the tubes are welded to the tube plate via external sleeves in which case the ultrasound is used in a similar manner to inspect the sleeve/tube plate weld. an electromagnetic transducer may be used to generate the ultrasound. The ultrasonic head comprising the crystal and an acoustic baffle is mounted on a Perspex (RTM) rod which may be rotated by a stepping motor. Echo signals from the region of deterioration may be isolated by use of a time gate in the receiver. The device primarily detects circumferentially orientated cracks, and may be used in heat exchangers in nuclear power plants. (author)

  15. 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.

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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.

  1. 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)

  2. The Tip-Induced Twisted Bilayer Graphene Superlattice on HOPG: Capillary Attraction Effect

    CERN Document Server

    Yin, Long Jing; Feng, Ke Ke; Dou, Rui-Fen; Nie, Jia-Cai

    2014-01-01

    We use the tip of the scanning tunneling microscope (STM) to manipulate single weakly bound nanometer-sized sheets on the the highly oriented pyrolytic graphite (HOPG) surface through artifically increasing the tip and sample interaction in humid environment. By this means it is possible to tear apart a graphite sheet againt a step and fold this part onto the HOPG surface and thus generate the gaphene superlattices with hexagonal symmetry. The tip and sample surface interactions, including the van der Waals force, eletrostatic force and capillary attraction force originating from the Laplace pressure due to the formation of a highly curved fluid meniscus connecting the tip and sample, are discussed in details to understand the fromation mechnism of graphen superlattice induced by the STM tip. Especially, the capillary force is the key role in manipulating the graphite surface sheet in the hunmidity condition. Our approach may provides a simple and feasible route to prepare the controllable superlattices and g...

  3. Ultrafast Capillary Electrophoresis Isolation of DNA Aptamer for the PCR Amplification-Based Small Analyte Sensing

    Directory of Open Access Journals (Sweden)

    Emmanuelle eFiore

    2015-08-01

    Full Text Available Here, we report a new homogeneous DNA amplification-based aptamer assay for small analyte sensing. The aptamer of adenosine chosen as the model analyte was split into two fragments able to assemble in the presence of target. Primers were introduced at extremities of one fragment in order to generate the amplifiable DNA component. The amount of amplifiable fragment was quantifiable by Real-Time Polymerase Chain Reaction (RT-PCR amplification and directly reliable on adenosine concentration. This approach combines the very high separation efficiency and the homogeneous format (without immobilization of capillary electrophoresis and the sensitivity of real time PCR amplification. An ultrafast isolation of target-bound split aptamer (60 s was developed by designing a capillary electrophoresis input/ouput scheme. Such method was successfully applied to the determination of adenosine with a LOD of 1 µM.

  4. Demonstrating Chemical and Analytical Concepts in the Undergraduate Laboratory Using Capillary Electrophoresis and Micellar Electrokinetic Chromatography

    Science.gov (United States)

    Palmer, Christopher P.

    1999-11-01

    This paper describes instrumental analysis laboratory exercises that utilize capillary electrophoresis and micellar electrokinetic chromatography to demonstrate several analytical and chemical principles. Alkyl parabens (4-hydroxy alkyl benzoates), which are common ingredients in cosmetic formulations, are separated by capillary electrophoresis. The electrophoretic mobilities of the parabens can be explained on the basis of their relative size. 3-Hydroxy ethylbenzoate is also separated to demonstrate the effect of substituent position on the acid dissociation constant and the effect this has on electrophoretic mobility. Homologous series of alkyl benzoates and alkyl phthalates (common plasticizers) are separated by micellar electrokinetic chromatography at four surfactant concentrations. This exercise demonstrates the separation mechanism of micellar electrokinetic chromatography, the concept of chromatographic phase ratio, and the concepts of micelle formation. A photodiode array detector is used in both exercises to demonstrate the advantages and limitations of the detector and to demonstrate the effect of pH and substituent position on the spectra of the analytes.

  5. Ultrafast Capillary Electrophoresis Isolation of DNA Aptamer for the PCR Amplification-Based Small Analyte Sensing

    Science.gov (United States)

    Fiore, Emmanuelle; Dausse, Eric; Dubouchaud, Hervé; Peyrin, Eric; Ravelet, Corinne

    2015-08-01

    Here, we report a new homogeneous DNA amplification-based aptamer assay for small analyte sensing. The aptamer of adenosine chosen as the model analyte was split into two fragments able to assemble in the presence of target. Primers were introduced at extremities of one fragment in order to generate the amplifiable DNA component. The amount of amplifiable fragment was quantifiable by Real-Time Polymerase Chain Reaction (RT-PCR) amplification and directly reliable on adenosine concentration. This approach combines the very high separation efficiency and the homogeneous format (without immobilization) of capillary electrophoresis and the sensitivity of real time PCR amplification. An ultrafast isolation of target-bound split aptamer (60 s) was developed by designing a capillary electrophoresis input/ouput scheme. Such method was successfully applied to the determination of adenosine with a LOD of 1 µM.

  6. 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...

  7. 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

  8. 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

  9. 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...

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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.

  17. High-Throughput Analysis With 96-Capillary Array Electrophoresis and Integrated Sample Preparation for DNA Sequencing Based on Laser Induced Fluorescence Detection

    Energy Technology Data Exchange (ETDEWEB)

    Gang Xue

    2001-12-31

    The purpose of this research was to improve the fluorescence detection for the multiplexed capillary array electrophoresis, extend its use beyond the genomic analysis, and to develop an integrated micro-sample preparation system for high-throughput DNA sequencing. The authors first demonstrated multiplexed capillary zone electrophoresis (CZE) and micellar electrokinetic chromatography (MEKC) separations in a 96-capillary array system with laser-induced fluorescence detection. Migration times of four kinds of fluoresceins and six polyaromatic hydrocarbons (PAHs) are normalized to one of the capillaries using two internal standards. The relative standard deviations (RSD) after normalization are 0.6-1.4% for the fluoresceins and 0.1-1.5% for the PAHs. Quantitative calibration of the separations based on peak areas is also performed, again with substantial improvement over the raw data. This opens up the possibility of performing massively parallel separations for high-throughput chemical analysis for process monitoring, combinatorial synthesis, and clinical diagnosis. The authors further improved the fluorescence detection by step laser scanning. A computer-controlled galvanometer scanner is adapted for scanning a focused laser beam across a 96-capillary array for laser-induced fluorescence detection. The signal at a single photomultiplier tube is temporally sorted to distinguish among the capillaries. The limit of detection for fluorescein is 3 x 10{sup -11} M (S/N = 3) for 5-mW of total laser power scanned at 4 Hz. The observed cross-talk among capillaries is 0.2%. Advantages include the efficient utilization of light due to the high duty-cycle of step scan, good detection performance due to the reduction of stray light, ruggedness due to the small mass of the galvanometer mirror, low cost due to the simplicity of components, and flexibility due to the independent paths for excitation and emission.

  18. Blood-Vessel Mimicking Structures by Stereolithographic Fabrication of Small Porous Tubes Using Cytocompatible Polyacrylate Elastomers, Biofunctionalization and Endothelialization

    Directory of Open Access Journals (Sweden)

    Birgit Huber

    2016-04-01

    Full Text Available Blood vessel reconstruction is still an elusive goal for the development of in vitro models as well as artificial vascular grafts. In this study, we used a novel photo-curable cytocompatible polyacrylate material (PA for freeform generation of synthetic vessels. We applied stereolithography for the fabrication of arbitrary 3D tubular structures with total dimensions in the centimeter range, 300 µm wall thickness, inner diameters of 1 to 2 mm and defined pores with a constant diameter of approximately 100 µm or 200 µm. We established a rinsing protocol to remove remaining cytotoxic substances from the photo-cured PA and applied thio-modified heparin and RGDC-peptides to functionalize the PA surface for enhanced endothelial cell adhesion. A rotating seeding procedure was introduced to ensure homogenous endothelial monolayer formation at the inner luminal tube wall. We showed that endothelial cells stayed viable and adherent and aligned along the medium flow under fluid-flow conditions comparable to native capillaries. The combined technology approach comprising of freeform additive manufacturing (AM, biomimetic design, cytocompatible materials which are applicable to AM, and biofunctionalization of AM constructs has been introduced as BioRap® technology by the authors.

  19. Blood-Vessel Mimicking Structures by Stereolithographic Fabrication of Small Porous Tubes Using Cytocompatible Polyacrylate Elastomers, Biofunctionalization and Endothelialization.

    Science.gov (United States)

    Huber, Birgit; Engelhardt, Sascha; Meyer, Wolfdietrich; Krüger, Hartmut; Wenz, Annika; Schönhaar, Veronika; Tovar, Günter E M; Kluger, Petra J; Borchers, Kirsten

    2016-01-01

    Blood vessel reconstruction is still an elusive goal for the development of in vitro models as well as artificial vascular grafts. In this study, we used a novel photo-curable cytocompatible polyacrylate material (PA) for freeform generation of synthetic vessels. We applied stereolithography for the fabrication of arbitrary 3D tubular structures with total dimensions in the centimeter range, 300 µm wall thickness, inner diameters of 1 to 2 mm and defined pores with a constant diameter of approximately 100 µm or 200 µm. We established a rinsing protocol to remove remaining cytotoxic substances from the photo-cured PA and applied thio-modified heparin and RGDC-peptides to functionalize the PA surface for enhanced endothelial cell adhesion. A rotating seeding procedure was introduced to ensure homogenous endothelial monolayer formation at the inner luminal tube wall. We showed that endothelial cells stayed viable and adherent and aligned along the medium flow under fluid-flow conditions comparable to native capillaries. The combined technology approach comprising of freeform additive manufacturing (AM), biomimetic design, cytocompatible materials which are applicable to AM, and biofunctionalization of AM constructs has been introduced as BioRap(®) technology by the authors. PMID:27104576

  20. Steam generator tube integrity program

    Energy Technology Data Exchange (ETDEWEB)

    Dierks, D.R.; Shack, W.J. [Argonne National Laboratory, IL (United States); Muscara, J.

    1996-03-01

    A new research program on steam generator tubing degradation is being sponsored by the U.S. Nuclear Regulatory Commission (NRC) at Argonne National Laboratory. This program is intended to support a performance-based steam generator tube integrity rule. Critical areas addressed by the program include evaluation of the processes used for the in-service inspection of steam generator tubes and recommendations for improving the reliability and accuracy of inspections; validation and improvement of correlations for evaluating integrity and leakage of degraded steam generator tubes, and validation and improvement of correlations and models for predicting degradation in steam generator tubes as aging occurs. The studies will focus on mill-annealed Alloy 600 tubing, however, tests will also be performed on replacement materials such as thermally-treated Alloy 600 or 690. An overview of the technical work planned for the program is given.