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Sample records for advancing contact line

  1. Anomalous contact angle hysteresis of a captive bubble: advancing contact line pinning.

    PubMed

    Hong, Siang-Jie; Chang, Feng-Ming; Chou, Tung-He; Chan, Seong Heng; Sheng, Yu-Jane; Tsao, Heng-Kwong

    2011-06-07

    Contact angle hysteresis of a sessile drop on a substrate consists of continuous invasion of liquid phase with the advancing angle (θ(a)) and contact line pinning of liquid phase retreat until the receding angle (θ(r)) is reached. Receding pinning is generally attributed to localized defects that are more wettable than the rest of the surface. However, the defect model cannot explain advancing pinning of liquid phase invasion driven by a deflating bubble and continuous retreat of liquid phase driven by the inflating bubble. A simple thermodynamic model based on adhesion hysteresis is proposed to explain anomalous contact angle hysteresis of a captive bubble quantitatively. The adhesion model involves two solid–liquid interfacial tensions (γ(sl) > γ(sl)′). Young’s equation with γ(sl) gives the advancing angle θ(a) while that with γ(sl)′ due to surface rearrangement yields the receding angle θ(r). Our analytical analysis indicates that contact line pinning represents frustration in surface free energy, and the equilibrium shape corresponds to a nondifferential minimum instead of a local minimum. On the basis of our thermodynamic model, Surface Evolver simulations are performed to reproduce both advancing and receding behavior associated with a captive bubble on the acrylic glass.

  2. Theory of Wetting-Induced Fluid Entrainment by Advancing Contact Lines on Dry Surfaces

    NASA Astrophysics Data System (ADS)

    Ledesma-Aguilar, R.; Hernández-Machado, A.; Pagonabarraga, I.

    2013-06-01

    We report on the onset of fluid entrainment when a contact line is forced to advance over a dry solid of arbitrary wettability. We show that entrainment occurs at a critical advancing speed beyond which the balance between capillary, viscous, and contact-line forces sustaining the shape of the interface is no longer satisfied. Wetting couples to the hydrodynamics by setting both the morphology of the interface at small scales and the viscous friction of the front. We find that the critical deformation that the interface can sustain is controlled by the friction at the contact line and the viscosity contrast between the displacing and displaced fluids, leading to a rich variety of wetting-entrainment regimes. We discuss the potential use of our theory to measure contact-line forces using atomic force microscopy and to study entrainment under microfluidic conditions exploiting colloid-polymer fluids of ultralow surface tension.

  3. Theory of wetting-induced fluid entrainment by advancing contact lines on dry surfaces.

    PubMed

    Ledesma-Aguilar, R; Hernández-Machado, A; Pagonabarraga, I

    2013-06-28

    We report on the onset of fluid entrainment when a contact line is forced to advance over a dry solid of arbitrary wettability. We show that entrainment occurs at a critical advancing speed beyond which the balance between capillary, viscous, and contact-line forces sustaining the shape of the interface is no longer satisfied. Wetting couples to the hydrodynamics by setting both the morphology of the interface at small scales and the viscous friction of the front. We find that the critical deformation that the interface can sustain is controlled by the friction at the contact line and the viscosity contrast between the displacing and displaced fluids, leading to a rich variety of wetting-entrainment regimes. We discuss the potential use of our theory to measure contact-line forces using atomic force microscopy and to study entrainment under microfluidic conditions exploiting colloid-polymer fluids of ultralow surface tension.

  4. Tungsten Contact and Line Resistance Reduction with Advanced Pulsed Nucleation Layer and Low Resistivity Tungsten Treatment

    NASA Astrophysics Data System (ADS)

    Chandrashekar, Anand; Chen, Feng; Lin, Jasmine; Humayun, Raashina; Wongsenakhum, Panya; Chang, Sean; Danek, Michal; Itou, Takamasa; Nakayama, Tomoo; Kariya, Atsushi; Kawaguchi, Masazumi; Hizume, Shunichi

    2010-09-01

    This paper describes electrical testing results of new tungsten chemical vapor deposition (CVD-W) process concepts that were developed to address the W contact and bitline scaling issues on 55 nm node devices. Contact resistance (Rc) measurements in complementary metal oxide semiconductor (CMOS) devices indicate that the new CVD-W process for sub-32 nm and beyond - consisting of an advanced pulsed nucleation layer (PNL) combined with low resistivity tungsten (LRW) initiation - produces a 20-30% drop in Rc for diffused NiSi contacts. From cross-sectional bright field and dark field transmission electron microscopy (TEM) analysis, such Rc improvement can be attributed to improved plugfill and larger in-feature W grain size with the advanced PNL+LRW process. More experiments that measured contact resistance for different feature sizes point to favorable Rc scaling with the advanced PNL+LRW process. Finally, 40% improvement in line resistance was observed with this process as tested on 55 nm embedded dynamic random access memory (DRAM) devices, confirming that the advanced PNL+LRW process can be an effective metallization solution for sub-32 nm devices.

  5. Dynamics of the Molten Contact Line

    NASA Technical Reports Server (NTRS)

    Sonin, Ain A.; Schiaffino, Stefano

    1996-01-01

    In contrast to the ordinary contact line problem, virtually no information is available on the similar problem associated with a molten material spreading on a solid which is below the melt's fusion point. The latter is a more complex problem which heat transfer and solidification take place simultaneously with spreading, and requires answers not only for the hot melt's advance speed over the cold solid as a function of contact angle, but also for how one is to predict the point of the molten contact line's arrest by freezing. This issues are of importance in evolving methods of materials processing. The purpose of our work is to develop, based on both experiments and theory, an understanding of the dynamic processes that occur when a molten droplet touches a subcooled solid, spreads partly over it by capillary action, and freezes. We seek answers to the following basic questions. First, what is the relationship between the melt's contact line speed and the apparent (dynamic) contact angle? Secondly, at what point will the contact line modon be arrested by freezing? The talk will describe three components of our work: (1) deposition experiments with small molten droplets; (2) investigation of the dynamics of the molten contact line by means of a novel forced spreading method; and (3) an attempt to provide a theoretical framework for answering the basic questions posed above.

  6. Microscale hydrodynamics near moving contact lines

    NASA Technical Reports Server (NTRS)

    Garoff, Stephen; Chen, Q.; Rame, Enrique; Willson, K. R.

    1994-01-01

    The hydrodynamics governing the fluid motions on a microscopic scale near moving contact lines are different from those governing motion far from the contact line. We explore these unique hydrodynamics by detailed measurement of the shape of a fluid meniscus very close to a moving contact line. The validity of present models of the hydrodynamics near moving contact lines as well as the dynamic wetting characteristics of a family of polymer liquids are discussed.

  7. Contact angle and local wetting at contact line.

    PubMed

    Li, Ri; Shan, Yanguang

    2012-11-06

    This theoretical study was motivated by recent experiments and theoretical work that had suggested the dependence of the static contact angle on the local wetting at the triple-phase contact line. We revisit this topic because the static contact angle as a local wetting parameter is still not widely understood and clearly known. To further clarify the relationship of the static contact angle with wetting, two approaches are applied to derive a general equation for the static contact angle of a droplet on a composite surface composed of heterogeneous components. A global approach based on the free surface energy of a thermodynamic system containing the droplet and solid surface shows the static contact angle as a function of local surface chemistry and local wetting state at the contact line. A local approach, in which only local forces acting on the contact line are considered, results in the same equation. The fact that the local approach agrees with the global approach further demonstrates the static contact angle as a local wetting parameter. Additionally, the study also suggests that the wetting described by the Wenzel and Cassie equations is also the local wetting of the contact line rather than the global wetting of the droplet.

  8. Probing with a laser sheet the contact angle distribution along a contact line.

    PubMed

    Rio, E; Daerr, A; Limat, L

    2004-01-01

    An optical method for probing contact angle distribution along contact lines of any shape using a laser sheet is proposed. This method is applied to a dry patch formed inside a film flowing along an inclined plane, both liquid and solid being transparent. Falling normally to the plane, a laser sheet cuts the contact line and is moved along this line. Distortions of the sheet trace observed on a screen put below the plane allow us to extract the contact angle distribution and the local line inclination along the line. Our results show that the contact angle around a dry patch is nearly constant and equal to the static advancing angle, at least when the evolution of its shape is followed for increasing flow rates. This supports a model of dry patch shape recently proposed by Podgorski and co-workers. Preliminary results obtained for decreasing flow are also qualitatively observed.

  9. Contact line and contact angle dynamics in superhydrophobic channels.

    PubMed

    Zhang, Junfeng; Kwok, Daniel Y

    2006-05-23

    The dynamics of the wetting and movement of a three-phase contact line confined between two superhydrophobic surfaces were studied using a mean-field free-energy lattice Boltzmann model. Principle features of superhydrophobic surfaces, such as trapped vapor/air between rough microstructures, high contact angles, reduced contact angle hysteresis, and low resistance to fluid flow, were all observed. Movement of the three-phase contact line over a well-patterned superhydrophobic surface displays a periodic stick-jump-slip behavior, while the dynamic contact angle changes accordingly from maximum to minimum. Two regimes were found for the flow velocity as a function of surface roughness and can be related directly to the balance between driving force and flow resistance. This work provides a better understanding of dynamic wetting and fluid flow behaviors over superhydrophobic surfaces and hence could be useful in related applications.

  10. High Reynolds number oscillating contact lines

    NASA Astrophysics Data System (ADS)

    Liu, Ziyuan; Schultz, William W.; Perlin, Marc

    1999-11-01

    Stainless steel, instead of Ting and Perlin's (1995) glass, is used in vertically oscillating plate experiments for a large range of Reynolds numbers. We used the non-wetting stainless steel to minimize the static meniscus that we ignore in our analysis. Except for the different static contact angle serving as an initial condition, the dynamic features in both cases are similar. In low Reynolds number oscillation, a pinned-edge condition can appropriately describe the contact line motion. In high Reynolds number oscillation, contact-line behavior becomes nonlinear and very complicated. The periodic, non-sinusoidal motion exhibits three types of motion: stick (associated with contact angle hysteresis), partial stick, and total slip. Increasing the Reynolds number, reduces the hysteresis phenomenon that still cannot be ignored. An edge condition allowing both the static range and dynamic interface behavior uses a slip coefficient mode that varies with time, stroke amplitude and frequency by introducing additional harmonic modes. Using this edge condition, we calculate the dynamic contact angle and the contact-line position for both stick and slip motion and compare them to our experimental data. Results show that the inviscid, linearized boundary-value problem combined with our slip coefficient model provides an improved prediction of the contact-line behavior.

  11. The Micromechanics of the Moving Contact Line

    NASA Technical Reports Server (NTRS)

    Han, Minsub; Lichter, Seth; Lin, Chih-Yu; Perng, Yeong-Yan

    1996-01-01

    The proposed research is divided into three components concerned with molecular structure, molecular orientation, and continuum averages of discrete systems. In the experimental program, we propose exploring how changes in interfacial molecular structure generate contact line motion. Rather than rely on the electrostatic and electrokinetic fields arising from the molecules themselves, we augment their interactions by an imposed field at the solid/liquid interface. By controling the field, we can manipulate the molecular structure at the solid/liquid interface. In response to controlled changes in molecular structure, we observe the resultant contact line motion. In the analytical portion of the proposed research we seek to formulate a system of equations governing fluid motion which accounts for the orientation of fluid molecules. In preliminary work, we have focused on describing how molecular orientation affects the forces generated at the moving contact line. Ideally, as assumed above, the discrete behavior of molecules can be averaged into a continuum theory. In the numerical portion of the proposed research, we inquire whether the contact line region is, in fact, large enough to possess a well-defined average. Additionally, we ask what types of behavior distinguish discrete systems from continuum systems. Might the smallness of the contact line region, in itself, lead to behavior different from that in the bulk? Taken together, our proposed research seeks to identify and accurately account for some of the molecular dynamics of the moving contact line, and attempts to formulate a description from which one can compute the forces at the moving contact line.

  12. Dynamics of the Molten Contact Line

    NASA Technical Reports Server (NTRS)

    Sonin, Ain A.; Duthaler, Gregg; Liu, Michael; Torresola, Javier; Qiu, Taiqing

    1999-01-01

    The purpose of this program is to develop a basic understanding of how a molten material front spreads over a solid that is below its melting point, arrests, and freezes. Our hope is that the work will contribute toward a scientific knowledge base for certain new applications involving molten droplet deposition, including the "printing" of arbitrary three-dimensional objects by precise deposition of individual molten microdrops that solidify after impact. Little information is available at this time on the capillarity-driven motion and arrest of molten contact line regions. Schiaffino and Sonin investigated the arrest of the contact line of a molten microcrystalline wax spreading over a subcooled solid "target" of the same material. They found that contact line arrest takes place at an apparent liquid contact angle that depends primarily on the Stefan number S=c(T(sub f) -T(sub t)/L based on the temperature difference between the fusion point and the target temperature, and proposed that contact line arrest occurs when the liquid's dynamic contact angle approaches the angle of attack of the solidification front just behind the contact line. They also showed, however, that the conventional continuum equations and boundary conditions have no meaningful solution for this angle. The solidification front angle is determined by the heat flux just behind the contact line, and the heat flux is singular at that point. By comparing experiments with numerical computations, Schiaffino and Sonin estimated that the conventional solidification model must break down within a distance of order 0.1 - 1 microns of the contact line. The physical mechanism for this breakdown is as yet undetermined, and no first-principles theory exists for the contact angle at arrest. Schiaffino and Sonin also presented a framework for understanding how to moderate Weber number molten droplet deposition in terms of similarity laws and experimentation. The study is based on experiments with three molten

  13. Moving contact line of a volatile fluid.

    PubMed

    Janeček, V; Andreotti, B; Pražák, D; Bárta, T; Nikolayev, V S

    2013-12-01

    Interfacial flows close to a moving contact line are inherently multiscale. The shape of the interface and the flow at meso- and macroscopic scales inherit an apparent interface slope and a regularization length, both named after Voinov, from the microscopic inner region. Here, we solve the inner problem associated with the contact line motion for a volatile fluid at equilibrium with its vapor. The evaporation or condensation flux is then controlled by the dependence of the saturation temperature on interface curvature-the so-called Kelvin effect. We derive the dependencies of the Voinov angle and of the Voinov length as functions of the parameters of the problem. We then identify the conditions under which the Kelvin effect is indeed the mechanism regularizing the contact line motion.

  14. The Micromechanics of the Moving Contact Line

    NASA Technical Reports Server (NTRS)

    Lichter, Seth

    1999-01-01

    A transient moving contact line is investigated experimentally. The dynamic interface shape between 20 and 800 microns from the contact line is compared with theory. A novel experiment is devised, in which the contact line is set into motion by electrically altering the solid-liquid surface tension gamma(sub SL). The contact line motion simulates that of spontaneous wetting along a vertical plate with a maximum capillary number Ca approx. = 4 x 10(exp -2). The images of the dynamic meniscus are analyzed as a funtion of Ca. For comparison, the steady-state hydrodynamic equation based on the creeping flow model in a wedge geometry and the three-region uniform perturbation expansion of Cox (1986) is adopted. The interface shape is well depicted by the uniform solutions for Ca <= 10(exp -3). However, for Ca > 10(exp -3), the uniform solution over-predicts the viscous bending. This over-prediction can be accounted for by modifying the slip coefficient within the intermediate solution. With this correction, the measured interface shape is seen to match the theoretical prediction for all capillary numbers. The amount of slip needed to fit the measurements does not scale with the capillary number.

  15. Coating with colloids by receding contact line

    NASA Astrophysics Data System (ADS)

    Berteloot, Guillaume; Laurent, Limat; Francois, Lequeux; Pham, Chi-Tuong; Daerr, Adrian; Receveur, Mathieu

    2008-11-01

    Many coating processes use evaporation. But such coatings are usually inhomogeneous because of the evaporation singularity at the contact line. We are thus investigating the effect of this singularity on dip-coating. In dip-coating, two flows are in competition: one inwards due to the receding contact line, the other outwards due to evaporation, and the equiibrium of thes flows predicts the thicknes of the deposit. There are two dip-coating regimes: one controlled by evaporation, and the known Landau-Levich regime. A minimum deposit thickness is expected between these two regimes. Using different microscopy techniques, we found out that there was a minimum in the deposit thickness, but that the actual mesoscopic order strongly varies depending on the contact line velocity. In the stick-slip regime, we can also link the spatial frequency of the stick-slip motion with the contact line velocity. Eventually, the thinnest deposits exhibits iridescence, which means that we are close to a photonic cristal structure.

  16. On multiscale moving contact line theory

    PubMed Central

    Li, Shaofan; Fan, Houfu

    2015-01-01

    In this paper, a multiscale moving contact line (MMCL) theory is presented and employed to simulate liquid droplet spreading and capillary motion. The proposed MMCL theory combines a coarse-grained adhesive contact model with a fluid interface membrane theory, so that it can couple molecular scale adhesive interaction and surface tension with hydrodynamics of microscale flow. By doing so, the intermolecular force, the van der Waals or double layer force, separates and levitates the liquid droplet from the supporting solid substrate, which avoids the shear stress singularity caused by the no-slip condition in conventional hydrodynamics theory of moving contact line. Thus, the MMCL allows the difference of the surface energies and surface stresses to drive droplet spreading naturally. To validate the proposed MMCL theory, we have employed it to simulate droplet spreading over various elastic substrates. The numerical simulation results obtained by using MMCL are in good agreement with the molecular dynamics results reported in the literature. PMID:26345090

  17. Line Tension Measurements through Drop Size Dependence of Contact Angle.

    PubMed

    Amirfazli; Kwok; Gaydos; Neumann

    1998-09-01

    Experiments with different organic liquids have been conducted to study the drop size dependence of the contact angles on a self-assembled monolayer (SAM) surface of 1-octadecanethiol (HS(CH2)17CH3) on gold. Low-rate dynamic advancing contact angles were measured for sessile drops in vapor-saturated air using Axisymmetric Drop Shape Analysis-Profile (ADSA-P). The experiments were performed using a minimum of eight separately prepared SAM surfaces for each liquid. Although a degree of scatter in the measured contact angles existed, the general trend observed for each run was that the contact angles decreased as the radius of the three-phase line for the sessile drop increased from approximately 1 to 5 mm. To obtain a better view of the overall trend, the contact angles from all of the individual runs for each liquid were averaged at corresponding radii. Subsequently, the averaged results from these experiments were interpreted using the modified Young equation. It was found that the drop size dependence of contact angles was due to a positive line tension. The line tension values are of the order of 1 µJ/m with a trend toward larger values for higher liquid surface tensions. Copyright 1998 Academic Press.

  18. Taming contact line instability for pattern formation

    PubMed Central

    Deblais, A.; Harich, R.; Colin, A.; Kellay, H.

    2016-01-01

    Coating surfaces with different fluids is prone to instability producing inhomogeneous films and patterns. The contact line between the coating fluid and the surface to be coated is host to different instabilities, limiting the use of a variety of coating techniques. Here we take advantage of the instability of a receding contact line towards cusp and droplet formation to produce linear patterns of variable spacings. We stabilize the instability of the cusps towards droplet formation by using polymer solutions that inhibit this secondary instability and give rise to long slender cylindrical filaments. We vary the speed of deposition to change the spacing between these filaments. The combination of the two gives rise to linear patterns into which different colloidal particles can be embedded, long DNA molecules can be stretched and particles filtered by size. The technique is therefore suitable to prepare anisotropic structures with variable properties. PMID:27506626

  19. Predictive models for moving contact line flows

    NASA Technical Reports Server (NTRS)

    Rame, Enrique; Garoff, Stephen

    2003-01-01

    Modeling flows with moving contact lines poses the formidable challenge that the usual assumptions of Newtonian fluid and no-slip condition give rise to a well-known singularity. This singularity prevents one from satisfying the contact angle condition to compute the shape of the fluid-fluid interface, a crucial calculation without which design parameters such as the pressure drop needed to move an immiscible 2-fluid system through a solid matrix cannot be evaluated. Some progress has been made for low Capillary number spreading flows. Combining experimental measurements of fluid-fluid interfaces very near the moving contact line with an analytical expression for the interface shape, we can determine a parameter that forms a boundary condition for the macroscopic interface shape when Ca much les than l. This parameter, which plays the role of an "apparent" or macroscopic dynamic contact angle, is shown by the theory to depend on the system geometry through the macroscopic length scale. This theoretically established dependence on geometry allows this parameter to be "transferable" from the geometry of the measurement to any other geometry involving the same material system. Unfortunately this prediction of the theory cannot be tested on Earth.

  20. Torque balance at a line of contact

    NASA Astrophysics Data System (ADS)

    Bukman, Dirk Jan

    2003-03-01

    Kerins and Boiteux (Physica A 117 (1983) 575) were the first to apply Noether's theorem to the van der Waals theory of non-uniform fluids. In particular, for a three-phase line of contact, they showed that the translation invariance of the variational integral for the excess free energy implies a balance of forces at the three-phase line. In this paper we consider the implications of the rotation invariance of the variational integral for the excess free energy. Intuitively, one would expect this invariance to lead to an equation of torque balance, and this is indeed the case-the total moment of the forces around the line of contact is zero. In the course of the calculation it will be necessary to find an expression for the surface of tension for a model with a multi-component density, which is a simple extension of earlier work by Fisher and Wortis (Phys. Rev. 29 (1984) 6252). At the same time, we extend to multi-component densities those authors’ results for the Tolman length and the equimolar surface, making contact with a more general calculation by Groenewold and Bedeaux (Physica A 214 (1995) 356).

  1. Interface structure behind a moving contact line

    NASA Astrophysics Data System (ADS)

    He, Mengfei; Nagel, Sidney

    2016-11-01

    When a flat solid substrate straddles the boundary between two fluids (e.g., water and air), there is a contact line where the two fluids and the solid meet. When the substrate is forced to penetrate further in either direction, it distorts the fluid interface and carries along with it a wedge of the trailing fluid. Numerous studies have investigated the onset of the contact-line motion in a two-dimensional geometry where it was assumed that no flows occurred in the direction along the surface of the substrate transverse to its direction of motion. Contrary to this assumption, we discovered that in steady state the fluid interface develops dramatic three-dimensional structure; there are multiple thin and thick regions of the fluid film alternating in the transverse direction. Thus the dynamics behind the contact line is not invariant in the transverse direction suggesting the existence of a new instability. We use interference to map the relative shape of this wedge-shaped region and a new interference technique to identify the absolute thickness of the wedge. It is particularly noteworthy that the same structure appears both in dewetting (when a substrate is removed from a liquid into the air) and in wetting (when it is plunged into the liquid).

  2. Contact line arrest in solidifying spreading drops

    NASA Astrophysics Data System (ADS)

    de Ruiter, Rielle; Colinet, Pierre; Snoeijer, Jacco; Gelderblom, Hanneke

    2016-11-01

    When does a drop, deposited on a cold substrate, stop spreading? Despite the practical relevance of this question, for example in airplane icing and 3D metal printing, the exact mechanism of arrest in solidifying spreading drops has not yet been unraveled. Here, we consider the spreading and arrest of hexadecane drops of constant volume on two smooth wettable substrates; copper with a high thermal conductivity and glass with a low thermal conductivity. We record the spreading radius and contact angle in time for a range of substrate temperatures. We show that our measurements on both copper and glass are well explained by a contact line arrest condition based on crystallization kinetics, which takes into account the effect of kinetic undercooling and the thermal conductivity of the substrate.

  3. The debate on the dependence of apparent contact angles on drop contact area or three-phase contact line: A review

    NASA Astrophysics Data System (ADS)

    Erbil, H. Yildirim

    2014-12-01

    A sessile drop is an isolated drop which has been deposited on a solid substrate where the wetted area is limited by the three-phase contact line and characterized by contact angle, contact radius and drop height. Although, wetting has been studied using contact angles of drops on solids for more than 200 years, the question remains unanswered: Is wetting of a rough and chemically heterogeneous surface controlled by the interactions within the solid/liquid contact area beneath the droplet or only at the three-phase contact line? After the publications of Pease in 1945, Extrand in 1997, 2003 and Gao and McCarthy in 2007 and 2009, it was proposed that advancing, receding contact angles, and contact angle hysteresis of rough and chemically heterogeneous surfaces are determined by interactions of the liquid and the solid at the three-phase contact line alone and the interfacial area within the contact perimeter is irrelevant. As a consequence of this statement, the well-known Wenzel (1934) and Cassie (1945) equations which were derived using the contact area approach are proposed to be invalid and should be abandoned. A hot debate started in the field of surface science after 2007, between the three-phase contact line and interfacial contact area approach defenders. This paper presents a review of the published articles on contact angles and summarizes the views of the both sides. After presenting a brief history of the contact angles and their measurement methods, we discussed the basic contact angle theory and applications of contact angles on the characterization of flat, rough and micropatterned superhydrophobic surfaces. The weak and strong sides of both three-phase contact line and contact area approaches were discussed in detail and some practical conclusions were drawn.

  4. Advanced high efficiency wraparound contact solar cell

    NASA Technical Reports Server (NTRS)

    Scott-Monck, J. A.; Uno, F. M.; Thornhill, J. W.

    1977-01-01

    A significant advancement in the development of thin high efficiency wraparound contact silicon solar cells has been made by coupling space and terrestrial processing procedures. Although this new method for fabricating cells has not been completely reduced to practice, some of the initial cells have delivered over 20 mW/sq cm when tested at 25 C under AMO intensity. This approach not only yields high efficiency devices, but shows promise of allowing complete freedom of choice in both the location and size of the wraparound contact pad area

  5. Advanced high efficiency wraparound contact solar cell

    NASA Technical Reports Server (NTRS)

    Scott-Monck, J. A.; Uno, F. M.; Thornhill, J. W.

    1977-01-01

    A significant advancement in the development of thin high efficiency wraparound contact silicon solar cells has been made by coupling space and terrestrial processing procedures. Although this new method for fabricating cells has not been completely reduced to practice, some of the initial cells have delivered over 20 mW/sq cm when tested at 25 C under AMO intensity. This approach not only yields high efficiency devices, but shows promise of allowing complete freedom of choice in both the location and size of the wraparound contact pad area.

  6. Response of driven sessile drops with contact-line dissipation.

    PubMed

    Bostwick, Joshua B; Steen, Paul H

    2016-11-04

    A partially-wetting sessile drop is driven by a sinusoidal pressure field that produces capillary waves on the liquid/gas interface. Response diagrams and phase shifts for the droplet, whose contact-line moves with contact-angle that is a smooth function of the contact line speed, are reported. Contact-line dissipation originating from the contact-line speed condition leads to damping for drops with finite contact-line mobility, even for inviscid fluids. The critical mobility and associated driving frequency to generate the largest contact-line dissipation is computed. Viscous dissipation is approximated using the irrotational flow and the critical Ohnesorge number bounding regions beyond which a given mode becomes over-damped is computed. Regions of modal coexistence where two modes can be simultaneously excited by a single forcing frequency are identified. Predictions compare favorably to related experiments on vibrated drops.

  7. Geysers advanced direct contact condenser research

    SciTech Connect

    Henderson, J.; Bahning, T.; Bharathan, D.

    1997-12-31

    The first geothermal application of the Advanced Direct Contact Condenser (ADCC) technology developed by the National Renewable Energy Laboratory (NREL) is now operational and is being tested at The Geysers Power Plant Unit 11. This major research effort is being supported through the combined efforts of NREL, The Department of Energy (DOE), and Pacific Gas and Electric (PG&E). NREL and PG&E have entered into a Cooperative Research And Development Agreement (CRADA) for a project to improve the direct-contact condenser performance at The Geysers Power Plant. This project is the first geothermal adaptation of an advanced condenser design developed for the Ocean Thermal Energy Conversion (OTEC) systems. PG&E expects this technology to improve power plant performance and to help extend the life of the steam field by using steam more efficiently. In accordance with the CRADA, no money is transferred between the contracting parties. In this case the Department of Energy is funding NREL for their efforts in this project and PG&E is contributing funds in kind. Successful application of this technology at The Geysers will provide a basis for NREL to continue to develop this technology for other geothermal and fossil power plant systems.

  8. Contact Line Pinning by Microfabricated Patterns: Effects of Microscale Topography

    PubMed Central

    Kalinin, Yevgeniy V.; Berejnov, Viatcheslav; Thorne, Robert E.

    2010-01-01

    We study how the microscale topography of a solid surface affects the apparent advancing and receding angles at the contact line of a liquid drop pinned to this surface. Photolithographic methods are used to produce continuous circular polymer rings of varying cross-sectional size and shape on hydrophilic silicon wafer surfaces. Drops of water and glycerol are dispensed into the areas bounded by these rings, and critical apparent advancing and receding angles are measured and correlated with the parameters that characterize the ring cross-section. For much of the examined parameter space, the apparent critical angles are independent of ring height and width and are determined primarily by the slope of the ring's sidewalls, consistent with a model due to Gibbs. For ring heights below a few micrometers, the critical angles decrease below the values predicted by the sidewall slopes alone. These results provide data for calculation of hysteresis on naturally rough surfaces, and demonstrate a simple method for controlling and enhancing contact line pinning on solid surfaces. PMID:19317420

  9. On some relations between advancing, receding and Young's contact angles.

    PubMed

    Chibowski, Emil

    2007-05-31

    Problems of experimental determination and theoretical verification of equilibrium contact angles are discussed basing on the literature data. A relationship between the advancing and receding contact angles versus the equilibrium contact angle is described and then verified using the literature contact angles determined on paraffin wax and polypropylene. Using the proposed relationship and experimentally determined equilibrium contact angles, obtained by plotting the advancing and receding contact angles versus the contact angle hysteresis or by applying vibration of the system liquid drop/solid surface, it is found that the same value of the surface free energy for paraffin wax is calculated from the contact angles of water and ethylene glycol. However, in the case of polypropylene some inconsistency appears between the equilibrium contact angles of the probe liquid used and the calculated surface free energy. More experimental data of the equilibrium contact angle are needed to verify further the relationship.

  10. Universal contact-line dynamics at the nanoscale.

    PubMed

    Rivetti, Marco; Salez, Thomas; Benzaquen, Michael; Raphaël, Elie; Bäumchen, Oliver

    2015-12-28

    The relaxation dynamics of the contact angle between a viscous liquid and a smooth substrate is studied at the nanoscale. Through atomic force microscopy measurements of polystyrene nanostripes we simultaneously monitor both the temporal evolution of the liquid-air interface and the position of the contact line. The initial configuration exhibits high curvature gradients and a non-equilibrium contact angle that drive liquid flow. Both these conditions are relaxed to achieve the final state, leading to three successive regimes in time: (i) stationary contact line levelling; (ii) receding contact line dewetting; (iii) collapse of the two fronts. For the first regime, we reveal the existence of a self-similar evolution of the liquid interface, which is in excellent agreement with numerical calculations from a lubrication model. For different liquid viscosities and film thicknesses we provide evidence for a transition to dewetting featuring a universal critical contact angle and dimensionless time.

  11. Fluctuations of a receding contact line near the entrainment transition

    NASA Astrophysics Data System (ADS)

    Bico, Jose; Delon, Giles; Fermigier, Marc

    2004-11-01

    We study experimentally the fluctuations of a contact line receding on a plane solid substrate. The contact line is perturbed by localized defects and we follow the relaxation of perturbations induced by these defects, as a function of the mean contact line speed and wavelengths characteristic of the perturbations. We compare our results with theoretical predictions by Golestanian and Raphael showing a divergence of the relaxation time at the entrainment transition (when the receding velocity exceeds a critical value, the liquid is entrained by the solid).

  12. Determination of the contact line for protective goggles

    SciTech Connect

    Boyarov, M.M.; Kaiyumov, Kh.M.; Larina, Zh.G.; Zhuk, G.V.

    1982-11-01

    The contact line of protective goggles of closed type should correspond to the anthropometric structure of the face and head, whose dimensional characteristics vary from one person to another. It is therefore desirable to determine average statistical values characterizing the line of contact. Up to now, the parameters of the contact line have been determined from practical experience in the design of protective goggles in view of the absence of scientific data on the detailed structure of the face and head. This organization has devised a special stereophotogrammetric apparatus and a method of defining the parameters required in the design of means of protecting the eyes and face.

  13. Self-Pinning by Colloids Confined at a Contact Line

    NASA Astrophysics Data System (ADS)

    Weon, Byung Mook; Je, Jung Ho

    2013-01-01

    Colloidal particles suspended in a fluid usually inhibit complete wetting of the fluid on a solid surface and cause pinning of the contact line, known as self-pinning. We show differences in spreading and drying behaviors of pure and colloidal droplets using optical and confocal imaging methods. These differences come from spreading inhibition by colloids confined at a contact line. We propose a self-pinning mechanism based on spreading inhibition by colloids. We find a good agreement between the mechanism and the experimental result taken by directly tracking individual colloids near the contact lines of evaporating colloidal droplets.

  14. Thermal fluctuations of an interface near a contact line.

    PubMed

    Belardinelli, D; Sbragaglia, M; Gross, M; Andreotti, B

    2016-11-01

    The effect of thermal fluctuations near a contact line of a liquid interface partially wetting an impenetrable substrate is studied analytically and numerically. Promoting both the interface profile and the contact line position to random variables, we explore the equilibrium properties of the corresponding fluctuating contact line problem based on an interfacial Hamiltonian involving a "contact" binding potential. To facilitate an analytical treatment, we consider the case of a one-dimensional interface. The effective boundary condition at the contact line is determined by a dimensionless parameter that encodes the relative importance of thermal energy and substrate energy at the microscopic scale. We find that this parameter controls the transition from a partial wetting to a pseudopartial wetting state, the latter being characterized by a thin prewetting film of fixed thickness. In the partial wetting regime, instead, the profile typically approaches the substrate via an exponentially thinning prewetting film. We show that, independently of the physics at the microscopic scale, Young's angle is recovered sufficiently far from the substrate. The fluctuations of the interface and of the contact line give rise to an effective disjoining pressure, exponentially decreasing with height. Fluctuations therefore provide a regularization of the singular contact forces occurring in the corresponding deterministic problem.

  15. Thermal fluctuations of an interface near a contact line

    NASA Astrophysics Data System (ADS)

    Belardinelli, D.; Sbragaglia, M.; Gross, M.; Andreotti, B.

    2016-11-01

    The effect of thermal fluctuations near a contact line of a liquid interface partially wetting an impenetrable substrate is studied analytically and numerically. Promoting both the interface profile and the contact line position to random variables, we explore the equilibrium properties of the corresponding fluctuating contact line problem based on an interfacial Hamiltonian involving a "contact" binding potential. To facilitate an analytical treatment, we consider the case of a one-dimensional interface. The effective boundary condition at the contact line is determined by a dimensionless parameter that encodes the relative importance of thermal energy and substrate energy at the microscopic scale. We find that this parameter controls the transition from a partial wetting to a pseudopartial wetting state, the latter being characterized by a thin prewetting film of fixed thickness. In the partial wetting regime, instead, the profile typically approaches the substrate via an exponentially thinning prewetting film. We show that, independently of the physics at the microscopic scale, Young's angle is recovered sufficiently far from the substrate. The fluctuations of the interface and of the contact line give rise to an effective disjoining pressure, exponentially decreasing with height. Fluctuations therefore provide a regularization of the singular contact forces occurring in the corresponding deterministic problem.

  16. Microdroplet evaporation with a forced pinned contact line.

    PubMed

    Gleason, Kevin; Putnam, Shawn A

    2014-09-02

    Experimental and numerical investigations of water microdroplet evaporation on heated, laser patterned polymer substrates are reported. The study is focused on both (i) controlling a droplet's contact line dynamics during evaporation to identifying how the contact line influences evaporative heat transfer and (ii) validating numerical simulations with experimental data. Droplets are formed on the polymer surface using a bottom-up methodology, where a computer-controlled syringe pump feeds water through a 200 μm diameter fluid channel within the heated polymer substrate. This methodology facilitates precise control of the droplet's growth rate, size, and inlet temperature. In addition to this microchannel supply line, the substrate surfaces are laser patterned with a moatlike trench around the fluid-channel outlet, adding additional control of the droplet's contact line motion, area, and contact angle. In comparison to evaporation on a nonpatterned polymer surface, the laser patterned trench increases contact line pinning time by ∼60% of the droplet's lifetime. Numerical simulations of diffusion controlled evaporation are compared the experimental data with a pinned contact line. These diffusion based simulations consistently over predict the droplet's evaporation rate. In efforts to improve this model, a temperature distribution along the droplet's liquid-vapor interface is imposed to account for the concentration distribution of saturated vapor along the interface, which yields improved predictions within 2-4% of the experimental data throughout the droplet's lifetime on heated substrates.

  17. Thermally activated depinning motion of contact lines in pseudopartial wetting.

    PubMed

    Du, Lingguo; Bodiguel, Hugues; Colin, Annie

    2014-07-01

    We investigate pressure-driven motion of liquid-liquid menisci in circular tubes, for systems in pseudopartial wetting conditions. The originality of this type of wetting lies in the coexistence of a macroscopic contact angle with a wetting liquid film covering the solid surface. Focusing on small capillary numbers, we report observations of an apparent contact angle hysteresis at first sight similar to the standard partial wetting case. However, this apparent hysteresis exhibits original features. We observe very long transient regimes before steady state, up to several hundreds of seconds. Furthermore, in steady state, the velocities are nonzero, meaning that the contact line is not strongly pinned to the surface defects, but are very small. The velocity of the contact line tends to vanish near the equilibrium contact angle. These observations are consistent with the thermally activated depinning theory that has been proposed to describe partial wetting systems on disordered substrates and suggest that a single physical mechanism controls both the hysteresis (or the pinning) and the motion of the contact line. The proposed analysis leads to the conclusion that the depinning activated energy is lower with pseudopartial wetting systems than with partial wetting ones, allowing the direct observation of the thermally activated motion of the contact line.

  18. Self-pinning by colloids confined at a contact line

    NASA Astrophysics Data System (ADS)

    Weon, Byung; Je, Jung

    2013-03-01

    Colloidal particles suspended in a fluid usually inhibit complete wetting of the fluid on a solid surface and cause pinning of the contact line, known as self-pinning. We show differences in spreading and drying behaviors of pure and colloidal droplets using optical and confocal imaging methods. These differences come from spreading inhibition by colloids confined at a contact line. We propose a self-pinning mechanism based on spreading inhibition by colloids. We find a good agreement between the mechanism and the experimental result taken by directly tracking individual colloids near the contact lines of evaporating colloidal droplets. This research was supported by the Creative Research Initiatives (Functional X-ray Imaging) of MEST/NRF.

  19. Spreading, evaporation, and contact line dynamics of surfactant-laden microdrops.

    PubMed

    Gokhale, Shripad J; Plawsky, Joel L; Wayner, Peter C

    2005-08-30

    An optical technique based on the reflectivity measurements of a thin film was used to experimentally study the spreading, evaporation, contact line motion, and thin film characteristics of drops consisting of a water-surfactant (polyalkyleneoxide-modified heptamethyltrisiloxane, called superspreader) solution on a fused silica surface. On the basis of the experimental observations, we concluded that the surfactant adsorbs primarily at the solid-liquid and liquid-vapor interfaces near the contact line region. At equilibrium, the completely wetting corner meniscus was associated with a flat adsorbed film having a thickness of approximately 31 nm. The calculated Hamaker constant, A = -4.47 x 10(-)(20) J, shows that this thin film was stable under equilibrium conditions. During a subsequent evaporation/condensation phase-change process, the thin film of the surfactant solution was unstable, and it broke into microdrops having a finite contact angle. The thickness of the adsorbed film associated with the drops was lower than that of the equilibrium meniscus. The drop profiles were experimentally measured and analyzed during the phase-change process as the contact line advanced and receded. The apparent contact angle, the maximum concave curvature near the contact line region, and the convex curvature of the drop increased as the drop grew during condensation, whereas these quantities decreased during evaporation. The position of the maximum concave curvature of the drop moved toward the center of the drop during condensation, whereas it moved away from the center during evaporation. The contact line velocity was correlated to the observed experimental results and was compared with the results of the drops of a pure alcohol. The experimentally obtained thickness profiles, contact angle profiles, and curvature profiles of the drops explain how the surfactant adsorption affects the contact line motion. We found that there was an abrupt change in the velocity of the

  20. Dynamic contact angle and three-phase contact line of water drop on copper surface

    NASA Astrophysics Data System (ADS)

    Orlova, E. G.; Feoktistov, D. V.; Batishcheva, K. A.

    2015-10-01

    Nowadays there is a lack of experimental data describing the physical process of drop spreading on a solid metal surface for developing wetting and spreading theory. The experimental data obtained by using the high speed video-recording will allow to identify unknown previously spreading modes as well as the change of the dynamic contact angle and the three-phase contact line. The purpose of the work is to determine the effect of the drop growth rate and the copper substrate surface roughness on the dynamic contact angle and the three-phase contact line speed at distilled water drop spreading. Shadow and Schlieren methods are used to obtain experimental data. Three drop spreading modes on the rough surfaces were identified. Time dependences of the dynamic contact angle and contact line speed were obtained. Experimental results can be used for assessing the validity of the developed mathematical models of wetting and spreading processes in the field of micro- and nanoelectronics, ink jet printing, thin-film coatings, spray cooling, and optoelectronics.

  1. Numerical Simulation of Dynamic Contact Angles and Contact Lines in Multiphase Flows using Level Set Method

    NASA Astrophysics Data System (ADS)

    Pendota, Premchand

    Many physical phenomena and industrial applications involve multiphase fluid flows and hence it is of high importance to be able to simulate various aspects of these flows accurately. The Dynamic Contact Angles (DCA) and the contact lines at the wall boundaries are a couple of such important aspects. In the past few decades, many mathematical models were developed for predicting the contact angles of the inter-face with the wall boundary under various flow conditions. These models are used to incorporate the physics of DCA and contact line motion in numerical simulations using various interface capturing/tracking techniques. In the current thesis, a simple approach to incorporate the static and dynamic contact angle boundary conditions using the level set method is developed and implemented in multiphase CFD codes, LIT (Level set Interface Tracking) (Herrmann (2008)) and NGA (flow solver) (Desjardins et al (2008)). Various DCA models and associated boundary conditions are reviewed. In addition, numerical aspects such as the occurrence of a stress singularity at the contact lines and grid convergence of macroscopic interface shape are dealt with in the context of the level set approach.

  2. Traction in elastohydrodynamic line contacts for two synthesized hydrocarbon fluids

    NASA Technical Reports Server (NTRS)

    Trachman, E. G.; Cheng, H. S.

    1973-01-01

    The paper describes the disk machine designed and constructed for the investigation of the traction in elastohydrodynamic line contacts for two synthesized hydrocarbon fluids. The results of this experimental study are presented and compared with the theoretical predictions of traction according to the thermal and non-Newtonian theory recently presented by the authors.

  3. Unusual Contact-Line Dynamics of Thick Films and Drops

    NASA Technical Reports Server (NTRS)

    Veretennikov, Igor; Agarwal, Abhishek; Indeikina, Alexandra; Chang, Hsueh-Chia

    1999-01-01

    We report several novel phenomena In contact-line and fingering dynamics of macroscopic spinning drops and gravity-driven films with dimensions larger than the capillary length. It is shown through experimental and theoretical analysis that such macroscopic films can exhibit various interfacial shapes, including multi valued ones, near the contact line due to a balance between the external body forces with capillarity. This rich variety of front shapes couples with the usual capillary, viscous, and intermolecular forces at the contact line to produce a rich and unexpected spectrum of contact-line dynamics. A single finger develops when part of the front becomes multivalued on a partially wetting macroscopic spinning drop in contrast to a different mechanism for microscopic drops of completely wetting fluids. Contrary to general expectation, we observe that, at high viscosity and low frequencies of rotation, the speed of a glycerine finger increases with increasing viscosity. Completely wetting Dow Corning 200 Fluid spreads faster over a dry inclined plane than a prewetted one. The presence of a thin prewetted film suppresses fingering both for gravity-driven flow and for spin coating. We analyze some of these unique phenomena in detail and offer qualitative physical explanations for the others.

  4. Interfacial waves generated by electrowetting-driven contact line motion

    NASA Astrophysics Data System (ADS)

    Ha, Jonghyun; Park, Jaebum; Kim, Yunhee; Shin, Bongsu; Bae, Jungmok; Kim, Ho-Young

    2016-10-01

    The contact angle of a liquid-fluid interface can be effectively modulated by the electrowetting-on-dielectric (EWOD) technology. Rapid movement of the contact line can be achieved by swift changes of voltage at the electrodes, which can give rise to interfacial waves under the strong influence of surface tension. Here we experimentally demonstrate EWOD-driven interfacial waves of overlapping liquids and compare their wavelength and decay length with the theoretical results obtained by a perturbation analysis. Our theory also allows us to predict the temporal evolution of the interfacial profiles in either rectangular or cylindrical containers, as driven by slipping contact lines. This work builds a theoretical framework to understand and predict the dynamics of capillary waves of a liquid-liquid interface driven by EWOD, which has practical implications on optofluidic devices used to guide light.

  5. Interferometric control of contact line, shape, and aberrations of liquid lenses

    NASA Astrophysics Data System (ADS)

    Voitenko, Igor; Storm, Ronald; Westfall, Raymond; Rogers, Stanley

    2007-09-01

    An optical system consisting of an aqueous electrolyte resting on a polymer/gold/indium-tin-oxide (ITO) layer deposited onto a glass substrate is analyzed to acquire contact angle - focal distance data as a function of applied voltage. The shape factor of a liquid lens and its dependence on the perimeter of contact line and contact angle was analyzed in the presence of an electrical field applied between the electrolyte and planar electrode system. The contact angle of a liquid on a thin, transparent film of gold (20 nm thick) - on ITO under electrolyte solution could be varied from 110 +/- 3° when the gold was held at -2.4 V to 41 +/- 3° without voltage. The behavior of a water-based electrolyte and water-soluble polymer blend and its influence on the shape of contact line and profile of the lens were investigated by employing a holographic setup at wavelengths of 632.8 and 543.5 nm. Optical micrographs showing the profile of the lens, aberration-less aperture, deformation of contact line, and shape of the liquid lens, respectively, were analyzed in reflection and transmission. Both the advancing and receding contact angles were measured directly from digitized images of the profile of the lens. The dynamic range of linear beam steering and dependence of the focal length of the liquid lens on the applied voltage are discussed.

  6. Experimental investigation of contact angle, curvature, and contact line motion in dropwise condensation and evaporation.

    PubMed

    Gokhale, Shripad J; Plawsky, Joel L; Wayner, Peter C

    2003-03-15

    Image-analyzing interferometry is used to measure the apparent contact angle and the curvature of a drop and a meniscus during condensation and evaporation processes in a constrained vapor bubble (CVB) cell. The apparent contact angle is found to be a function of the interfacial mass flux. The interfacial velocity for the drop during condensation and evaporation is a function of the apparent contact angle and the rate of change of radius of curvature. The dependence of velocity on the apparent contact angle is consistent with Tanner's scaling equation. The results support the hypothesis that evaporation/condensation is an important factor in contact line motion. The main purpose of this article is to present the experimental technique and the data. The equilibrium contact angle for the drop is found experimentally to be higher than that for the corner meniscus. The contact angle is a function of the stress field in the fluid. The equilibrium contact angle is related to the thickness of the thin adsorbed film in the microscopic region and depends on the characteristics of the microscopic region. The excess interfacial free energy and temperature jump were used to calculate the equilibrium thickness of the thin adsorbed film in the microscopic region.

  7. Nucleation at the Contact Line Observed on Nanotextured Surfaces

    NASA Astrophysics Data System (ADS)

    Kostinski, A. B.; Gurganus, C.; Charnawskas, J. C.; Shaw, R. A.

    2015-12-01

    Surface nucleation, and contact nucleation in particular, are important for many physical processes, including pharmaceutical drug synthesis, metallurgy, and heterogeneous ice nucleation. It has been conjectured that roughness plays a role in surface nucleation, the tendency for freezing to begin preferentially at the liquid-gas interface. Using high speed imaging, we sought evidence for freezing at the contact line on catalyst substrates with imposed characteristic length scales (texture). It is found that nano-scale texture causes a shift in the nucleation of ice in super-cooled water to the three-phase contact line, while micro-scale texture does not. The reduction in the Gibbs barrier for nucleation at the droplet triple line suggests that a line tension, inversely proportional to the surface feature length scale, may be the relevant physical mechanism. A survey of line tension values in literature supports this hypothesis. This work suggests that the physical morphology of a particle, and not just its chemical composition, is important for characterizing a nucleation catalyst.

  8. Lattice boltzmann study on the contact angle and contact line dynamics of liquid-vapor interfaces.

    PubMed

    Zhang, Junfeng; Kwok, Daniel Y

    2004-09-14

    The moving contact line problem of liquid-vapor interfaces was studied using a mean-field free-energy lattice Boltzmann method recently proposed [Phys. Rev. E 2004, 69, 032602]. We have examined the static and dynamic interfacial behaviors by means of the bubble and capillary wave tests and found that both the Laplace equation of capillarity and the dispersion relation were satisfied. Dynamic contact angles followed the general trend of contact line velocity observed experimentally and can be described by Blake's theory. The velocity fields near the interface were also obtained and are in good agreement with fluid mechanics and molecular dynamics studies. Our simulations demonstrated that incorporating interfacial effects into the lattice Boltzmann model can be a valuable and powerful alternative in interfacial studies.

  9. Effect of contact line dynamics on the thermocapillary motion of a droplet on an inclined plate.

    PubMed

    Karapetsas, George; Sahu, Kirti Chandra; Matar, Omar K

    2013-07-16

    We study the two-dimensional dynamics of a droplet on an inclined, nonisothermal solid substrate. We use lubrication theory to obtain a single evolution equation for the interface, which accounts for gravity, capillarity, and thermo-capillarity, brought about by the dependence of the surface tension on temperature. The contact line motion is modeled using a relation that couples the contact line speed to the difference between the dynamic and equilibrium contact angles. The latter are allowed to vary dynamically during the droplet motion through the dependence of the liquid-gas, liquid-solid, and solid-gas surface tensions on the local contact line temperature, thereby altering the local substrate wettability at the two edges of the drop. This is an important feature of our model, which distinguishes it from previous work wherein the contact angle was kept constant. We use finite-elements for the discretization of all spatial derivatives and the implicit Euler method to advance the solution in time. A full parametric study is carried out in order to investigate the interplay between Marangoni stresses, induced by thermo-capillarity, gravity, and contact line dynamics in the presence of local wettability variations. Our results, which are generated for constant substrate temperature gradients, demonstrate that temperature-induced variations of the equilibrium contact angle give rise to complex dynamics. This includes enhanced spreading rates, nonmonotonic dependence of the contact line speed on the applied substrate temperature gradient, as well as "stick-slip" behavior. The mechanisms underlying this dynamics are elucidated herein.

  10. Stick-Slip to Sliding Transition of Dynamic Contact Lines under AC Electrowetting.

    PubMed

    't Mannetje, D J C M; Mugele, F; van den Ende, D

    2013-12-03

    We show that at low velocities the dynamics of a contact line of a water drop moving over a Teflon-like surface under ac electrowetting must be described as stick-slip motion, rather than one continuous movement. At high velocities we observe a transition to a slipping regime. In the slipping regime the observed dependence of the contact angle is well described by a linearization of both the hydrodynamic and the molecular-kinetic model for the dynamic contact line behavior. The overall geometry of the drop also has a strong influence on the contact angle: if the drop is confined to a disk-like shape with radius R, much larger than the capillary length, and height h, smaller than the capillary length, the advancing angle increases steeper with velocity as the aspect ratio h/R is smaller. Although influence of the flow field near a contact line on the contact angle behavior has also been observed in other experiments, these observations do not fit either model. Finally, in our ac experiments no sudden increase of the hysteresis beyond a certain voltage and velocity was observed, as reported by other authors for a dc voltage, but instead we find with increasing voltage a steady decrease of the hysteresis.

  11. Coffee Drops and Coffee Rings: Contact Line Deposits from Evaporation

    NASA Astrophysics Data System (ADS)

    Huber, Greg

    1997-03-01

    When a small drop of coffee placed on a counter top dries, it deposits a thin ring of concentrated solute at the perimeter of the drop. Similar rings form for a wide range of surfaces, solutes, and solvents, provided the contact line is pinned to the surface. An old result of Maxwell can be used to partially explain these dense rings. The predicted rate of ring deposition is shown to agree quantitatively with experimental measurements.

  12. Obtaining macroscopic quantities for the contact line problem from Density Functional Theory using asymptotic methods

    NASA Astrophysics Data System (ADS)

    Sibley, David; Nold, Andreas; Kalliadasis, Serafim

    2015-11-01

    Density Functional Theory (DFT), a statistical mechanics of fluids approach, captures microscopic details of the fluid density structure in the vicinity of contact lines, as seen in computations in our recent study. Contact lines describe the location where interfaces between two fluids meet solid substrates, and have stimulated a wealth of research due to both their ubiquity in nature and technological applications and also due to their rich multiscale behaviour. Whilst progress can be made computationally to capture the microscopic to mesoscopic structure from DFT, complete analytical results to fully bridge to the macroscale are lacking. In this work, we describe our efforts to bring asymptotic methods to DFT to obtain results for contact angles and other macroscopic quantities in various parameter regimes. We acknowledge financial support from European Research Council via Advanced Grant No. 247031.

  13. Classifying dynamic contact line modes in drying drops.

    PubMed

    Baldwin, Kyle Anthony; Fairhurst, David John

    2015-02-28

    Although the evaporation mode of sessile droplets is almost universally characterized as either constant contact radius (CCR) or constant contact angle (CCA), here we investigate two alternatives where the contact line speed is either constant or inversely proportional to the droplet radius. We present supporting evidence from our experiments on poly(ethylene oxide) (PEO) polymer solutions and blood, and from literature on pure and binary liquids, colloidal suspensions, soft substrates, reactive dewetting and hole nucleation. We introduce the use of novel "clock-drop" images to visualize droplet evolution and dimensionless height-radius plots to characterize the evaporative pathways. Combining these with a simple scaling argument, we show that receding speed is inversely proportional to the three-phase contact radius R, with a constant of proportionality A, which is dependent on the drying conditions and drop shape, but independent of drop volume. We have shown that this is equivalent to a linear decrease in contact area with time. By varying only A, which we achieved experimentally by choosing solutions whose precipitate constricts after deposition, the evaporation mode can be altered continuously to include the two established modes CCR and CCA, and two new modes which we term "slowly receding" and "rapidly receding", which are characterised by fully dried "doughnut" and "pillar" deposits respectively.

  14. The inner region of the moving contact line - diffusive and nanoscale models

    NASA Astrophysics Data System (ADS)

    Nold, Andreas; Sibley, David N.; Goddard, Ben D.; Kalliadasis, Serafim

    2015-11-01

    Much of the work within the Complex Multiphase Systems group at Imperial College London for the last number of years has been to understand the moving contact line problem. In, it was shown that contrary to the classical asymptotic theory at the moving contact line, the intermediate region is in fact an overlap region between the inner and the outer regions. Here, we investigate the inner region independently for the Navier-Stokes/ Cahn-Hilliard (NS/CH) model for binary fluids, as well as dynamic density functional theory (DDFT) for a simple fluid. We show that in the NS/CH model, the overlap region is recovered in the sharp-interface limit, and we link the slip length to the mobility of the system. In contrast, DDFT, which is based on statistical mechanics of fluids, allows to incorporate nanoscale details. Results are presented for advancing and receding contact lines for a wide range of contact angles. The numerical method employs spectral methods in an unbounded domain along the surface. Advantages are discussed, both for differential and integral DDFT equations. We acknowledge financial support from ERC Advanced Grant No. 247031 and Imperial College through a DTG International Studentship.

  15. Convex nanobending at a moving contact line: the missing mesoscopic link in dynamic wetting.

    PubMed

    Chen, Lei; Yu, Jiapeng; Wang, Hao

    2014-11-25

    The morphological information on the very front of a spreading liquid is fundamental to our understanding of dynamic wetting. Debate has lasted for years concerning the nanoscopic local angles and the transition from them to the macroscopic counterpart, θ(D). This study of nonvolatile liquids analyzes the interface profile near the advancing contact line using an advanced atomic force microscopy. The interface is found following the macroscopic profile until bending in a convex profile around 20 nm from the substrate. This shoe-tip-like feature is common in partially wetting while absent for completely wetting, and its curvature varies with advancing speed. The observation ends the long-standing debate about the nanoscopic contact angles and their speed dependency. The convex nanobending provides a mesoscopic link and effectively complicates the dynamic wetting behaviors.

  16. Characterizing the microscopic physics near moving contact lines using dynamic contact angle data.

    PubMed

    Ramé, E; Garoff, S; Willson, K R

    2004-09-01

    Directly probing the fluid flow and liquid-vapor interface shape in the microscopic immediate vicinity of the moving contact line can only be accomplished in very specific and isolated cases. Yet this physics is critical to macroscopic dynamic wetting. Here we examine the microscopic (or inner) physics of spreading silicone fluids using data of macroscopic dynamic contact angle versus Capillary number Ca=U mu/sigma. This dynamic contact angle is precisely defined so that it can be related back to the microscopic behavior through detailed theory. Our results indicate that the parameters describing the inner region have a detectable dependence on spreading velocity when this velocity exceeds a critical value. This dependence is not scaled (i.e., the data are not collapsed) by Ca, which suggests that an additional time scale must be present in the model of the inner region.

  17. Asymmetric and speed-dependent contact angle hysteresis and relaxation of a suddenly stopped moving contact line

    NASA Astrophysics Data System (ADS)

    Guan, Dongshi; Wang, Yong Jian; Charlaix, Elisabeth; Tong, Penger

    We report direct atomic-force-microscope measurements of capillary force hysteresis and relaxation of a circular moving contact line (CL) formed on a long micron-sized hydrophobic fiber intersecting a water-air interface. The measured capillary force hysteresis and CL relaxation show a strong asymmetric speed dependence in the advancing and receding directions. A unified model based on force-assisted barrier-crossing is utilized to find the underlying energy barrier Eb and size λ associated with the defects on the fiber surface. The experiment demonstrates that the pinning (relaxation) and depinning dynamics of the CL can be described by a common microscopic frame-work, and the advancing and receding CLs are influenced by two different sets of relatively wetting and non-wetting defects on the fiber surface. Work supported in part by the Research Grants Council of Hong Kong SAR.

  18. Measuring contact-line mobility during inertial spreading

    NASA Astrophysics Data System (ADS)

    Steen, Paul; Daniel, Susan; Xia, Yi

    2016-11-01

    During "inertial spreading", when inertia drives a partially wetting liquid across a solid, the role of bulk viscosity may be neglected. For such inertial-capillary motions, behavior of the moving contact-line (CL) can be understood within the context of ideal (or nearly ideal) fluid motion, provided an alternate to the Voinov-Hocking-Cox model of mobility is adopted. The alternate we adopt is the so-called Hocking condition. In this talk, we report experiments with Resonantly-Driven Droplets (RDD) whereby the bulk resonance of the drop amplifies the small and fast CL motion sufficiently to be measurable. The RDD approach enables us to measure a CL mobility and to infer a CL dissipation for droplets on a number of hydrophobic surfaces, surfaces with varying contact-angle hysteresis. Our results are compared to prior results in the literature, measured with alternative approaches. National Science Foundation Grant No. CBET-1236582.

  19. Mathematical modeling of moving contact lines in heat transfer applications

    NASA Astrophysics Data System (ADS)

    Ajaev, Vladimir S.; Klentzman, J.; Sodtke, C.; Stephan, P.

    2007-10-01

    We provide an overview of research on the mathematical modeling of apparent contact lines in non-isothermal systems conducted over the past several decades and report a number of recent developments in the field. The latter involve developing mathematical models of evaporating liquid droplets that account not only for liquid flow and evaporation, but also for unsteady heat conduction in the substrate. The droplet is placed on a flat heated solid substrate and is assumed to be in contact with a saturated vapor. Furthermore, we discuss a careful comparison between mathematical models and experimental work that involves simultaneous measurement of shapes of evaporating droplets and temperature profiles in the solid substrate. The latter is accomplished using thermochromic liquid crystals. Applications to new research areas, such as studies of the effect of evaporation on fingering instabilities in gravity-driven liquid films, are also discussed.

  20. Modeling the initial contact line dynamics of dewetting bubbles

    NASA Astrophysics Data System (ADS)

    Menesses, Mark; Laurent, Matthieu; Bird, James

    2016-11-01

    When a rising bubble comes to rest beneath a solid horizontal surface, the resulting liquid film dewets to minimize the total free energy of the three phase system. For partially wetting surfaces, the presence of the contact angle yields dynamics which are assumed to be governed by viscous effects. In contrast, the early-time dynamics for drops spreading on partially wetting surfaces are dominated by inertial effects. Motivated by the discrepancy between these two systems, we conduct experiments on dewetting bubbles and find that the short-time dynamics fail to obey purely viscous or inertial scalings. We draw from previously proposed dewetting and spreading models to develop a new model that can rationalize the anomalous scalings that we observe. Our results suggest that the speed that a bubble adheres to a partially wetting surface is set by an interplay of capillary waves and contact line motion. We acknowledge support from ONR, Saint-Gobain, and NSF GRFP.

  1. Description of the three-phase contact line expansion

    NASA Astrophysics Data System (ADS)

    Váchová, Tereza; Brabcová, Zuzana; Basařová, Pavlína

    2014-03-01

    Knowledge of bubble-particle interaction is important in many industrial processes such as in flotation. While the collision (first interaction sub-process) between bubbles and particles is influenced only by hydrodynamic forces, the bubble behaviour during the attachment (second sub-process) is influenced both by hydrodynamic and surface forces. This work is focused on the study of the three-phase contact (TPC) line expansion during bubble adhesion on hydrophobic surface and on its experimental and mathematical description. The experiments were carried out in pure water where mobile bubble surface is expected. The rising bubble was studied in dynamic arrangement, whereas the stationary bubble was analysed in static arrangement. The attachment process was recorded using a high-speed digital camera and evaluated using image analysis. The diameter of the expanding TPC line as well as the dynamic contact angle was determined. Two approaches - the hydrodynamic and the molecular-kinetic - were used for mathematical description of the TPC line expansion. According to our results, the hydrodynamic model is suitable for the description of the initial fast phase of the expansion. The molecular-kinetic model was assessed as appropriate for almost whole range of TPC expansion. Parameters of the model were evaluated and compared for both types of arrangement.

  2. Fixed contact line helical interfaces in zero gravity

    NASA Astrophysics Data System (ADS)

    Lowry, Brian J.; Thiessen, David B.

    2007-02-01

    Fluid interfaces supported in microgravity by a helical structure are shown to have a more robust stability than more common structures such as liquid bridges. In particular, helical interfaces can take the form of infinite right circular cylinders over a broad range of configurations. In the case of a single fixed contact line support, the infinite cylinder is stable for all cases in which the pitch to diameter ratio is less than π /√3 (more tightly coiled interfaces). When there are two or more equally spaced fixed contact line supports, the infinite cylinder is stable for all configurations. Furthermore, in the two support case (the double helix), stability persists for all volumes from the cylinder to zero volume, when the pitch to diameter ratio is greater than 2.082 (more loosely coiled interfaces). The equivalent to the axisymmetric Young-Laplace equation is derived for helical interfaces. Interfacial stability is determined from equilibrium branch structure following the application of Maddocks' method by Lowry and Steen [Proc. R. Soc. London, Ser. A 449, 411 (1995)]. Perturbations to finite wavelength disturbances are considered for the case of a single helical support. Overall stability envelopes are presented for single and multiple support cases. Limited experimental results verify the infinite length stability limit for the single helical support case.

  3. Direct determination of three-phase contact line properties on nearly molecular scale

    NASA Astrophysics Data System (ADS)

    Winkler, P. M.; McGraw, R. L.; Bauer, P. S.; Rentenberger, C.; Wagner, P. E.

    2016-05-01

    Wetting phenomena in multi-phase systems govern the shape of the contact line which separates the different phases. For liquids in contact with solid surfaces wetting is typically described in terms of contact angle. While in macroscopic systems the contact angle can be determined experimentally, on the molecular scale contact angles are hardly accessible. Here we report the first direct experimental determination of contact angles as well as contact line curvature on a scale of the order of 1nm. For water nucleating heterogeneously on Ag nanoparticles we find contact angles around 15 degrees compared to 90 degrees for the corresponding macroscopically measured equilibrium angle. The obtained microscopic contact angles can be attributed to negative line tension in the order of ‑10‑10 J/m that becomes increasingly dominant with increasing curvature of the contact line. These results enable a consistent theoretical description of heterogeneous nucleation and provide firm insight to the wetting of nanosized objects.

  4. Direct determination of three-phase contact line properties on nearly molecular scale.

    PubMed

    Winkler, P M; McGraw, R L; Bauer, P S; Rentenberger, C; Wagner, P E

    2016-05-17

    Wetting phenomena in multi-phase systems govern the shape of the contact line which separates the different phases. For liquids in contact with solid surfaces wetting is typically described in terms of contact angle. While in macroscopic systems the contact angle can be determined experimentally, on the molecular scale contact angles are hardly accessible. Here we report the first direct experimental determination of contact angles as well as contact line curvature on a scale of the order of 1nm. For water nucleating heterogeneously on Ag nanoparticles we find contact angles around 15 degrees compared to 90 degrees for the corresponding macroscopically measured equilibrium angle. The obtained microscopic contact angles can be attributed to negative line tension in the order of -10(-10) J/m that becomes increasingly dominant with increasing curvature of the contact line. These results enable a consistent theoretical description of heterogeneous nucleation and provide firm insight to the wetting of nanosized objects.

  5. Direct determination of three-phase contact line properties on nearly molecular scale

    PubMed Central

    Winkler, P. M.; McGraw, R. L.; Bauer, P. S.; Rentenberger, C.; Wagner, P. E.

    2016-01-01

    Wetting phenomena in multi-phase systems govern the shape of the contact line which separates the different phases. For liquids in contact with solid surfaces wetting is typically described in terms of contact angle. While in macroscopic systems the contact angle can be determined experimentally, on the molecular scale contact angles are hardly accessible. Here we report the first direct experimental determination of contact angles as well as contact line curvature on a scale of the order of 1nm. For water nucleating heterogeneously on Ag nanoparticles we find contact angles around 15 degrees compared to 90 degrees for the corresponding macroscopically measured equilibrium angle. The obtained microscopic contact angles can be attributed to negative line tension in the order of −10−10 J/m that becomes increasingly dominant with increasing curvature of the contact line. These results enable a consistent theoretical description of heterogeneous nucleation and provide firm insight to the wetting of nanosized objects. PMID:27183880

  6. Numerical simulations of the moving contact line problem using a diffuse-interface model

    NASA Astrophysics Data System (ADS)

    Afzaal, Muhammad; Sibley, David; Duncan, Andrew; Yatsyshin, Petr; Duran-Olivencia, Miguel A.; Nold, Andreas; Savva, Nikos; Schmuck, Markus; Kalliadasis, Serafim

    2015-11-01

    Moving contact lines are a ubiquitous phenomenon both in nature and in many modern technologies. One prevalent way of numerically tackling the problem is with diffuse-interface (phase-field) models, where the classical sharp-interface model of continuum mechanics is relaxed to one with a finite thickness fluid-fluid interface, capturing physics from mesoscopic lengthscales. The present work is devoted to the study of the contact line between two fluids confined by two parallel plates, i.e. a dynamically moving meniscus. Our approach is based on a coupled Navier-Stokes/Cahn-Hilliard model. This system of partial differential equations allows a tractable numerical solution to be computed, capturing diffusive and advective effects in a prototypical case study in a finite-element framework. Particular attention is paid to the static and dynamic contact angle of the meniscus advancing or receding between the plates. The results obtained from our approach are compared to the classical sharp-interface model to elicit the importance of considering diffusion and associated effects. We acknowledge financial support from European Research Council via Advanced Grant No. 247031.

  7. Vibration spectroscopy of a sessile drop and its contact line.

    PubMed

    Mettu, S; Chaudhury, M K

    2012-10-02

    Resonance frequencies of small sessile liquid drops (1-20 μL) were estimated from the power spectra of their height fluctuations after subjecting them to white noise vibration. Various resonance modes could be identified with this method as a function of the mass of the drop. Studies with water drops on such supports as polystyrene (θ ≈ 80°) and a superhydrophobic surface of microfibrillar silicone rubber (θ ≈ 162°) demonstrated that the resonant frequency decreases with the contact angle, θ. This trend is in remarkable agreement with the current models of the resonant vibration of sessile drops. A novel aspect of this study is the analysis of the modes of a slipping contact line that indicated that its higher frequency modes are more severely damped than its lower ones. Another case is with the glycerol-water solutions, where the resonance frequency decreases with the concentration of glycerol purely due to the capillary effects. The interface fluctuation, on the other hand, is strongly correlated with the kinematic viscosity of the liquid. Thus, these experiments provide a means to measure the surface tension and the viscosity of very small droplets.

  8. Dynamics of contact line depinning during droplet evaporation based on thermodynamics.

    PubMed

    Yu, Dong In; Kwak, Ho Jae; Doh, Seung Woo; Ahn, Ho Seon; Park, Hyun Sun; Kiyofumi, Moriyama; Kim, Moo Hwan

    2015-02-17

    For several decades, evaporation phenomena have been intensively investigated for a broad range of applications. However, the dynamics of contact line depinning during droplet evaporation has only been inductively inferred on the basis of experimental data and remains unclear. This study focuses on the dynamics of contact line depinning during droplet evaporation based on thermodynamics. Considering the decrease in the Gibbs free energy of a system with different evaporation modes, a theoretical model was developed to estimate the receding contact angle during contact line depinning as a function of surface conditions. Comparison of experimentally measured and theoretically modeled receding contact angles indicated that the dynamics of contact line depinning during droplet evaporation was caused by the most favorable thermodynamic process encountered during constant contact radius (CCR mode) and constant contact angle (CCA mode) evaporation to rapidly reach an equilibrium state during droplet evaporation.

  9. Coffee Stains from Drops with Receding Contact Lines

    NASA Astrophysics Data System (ADS)

    Freed-Brown, Julian

    2015-03-01

    We present a framework for calculating the surface density profile of a coffee stain deposited by a drying drop with a receding contact line. For standard coffee stains, the fluid pins to the substrate, forces flow towards the exterior of the drop and deposits a thin, concentrated ring of particles. Unlike a pinned drop, a receding drop pushes fluid towards its interior and continuously deposits mass across its substrate as it evaporates. This gives rise to a new class of mountain-like morphologies that are not seen in the standard coffee ring effect but are reminiscent of recent experimental results. For a thin, circular drop with uniform evaporation, we calculate the surface density profile analytically and find that it diverges towards the center of the drop as η ~r - 1 / 2 , where r is the distance from the center. We estimate how this divergence is softened due to solute interactions at the final stage of drying. Our framework can easily be extended numerically or analytically to investigate novel stain morphologies left by drying drops of different shapes and evaporation profiles. This work is part of a thesis project advised by Tom Witten. It was supported in part by the National Science Foundation's MRSEC Program under Award Number DMR 0820054.

  10. Modified Contact Line Dynamics about a Surface-Piercing Hydrofoil

    NASA Astrophysics Data System (ADS)

    Grivel, Morgane; Jeon, David; Gharib, Morteza

    2016-11-01

    The contact line around a surface-piercing hydrofoil is modified by introducing alternating hydrophobic and hydrophilic bands along one side of the body. These bands are either aligned perpendicular or parallel to the flow direction. The other side of the hydrofoil is un-patterned and retains its original, uniformly hydrophilic properties. The hydrofoil is mounted onto air bearings, such that it can freely move side-to-side in the water tunnel. A force sensor is attached to the setup via a universal joint in order to measure the forces acting on the body for several Reynolds numbers (ranging from 104 to 105) and angles of attack (ranging from -10o to 10o) . Cameras are also used to record the resulting flow structures and free surface elevation. The generation of wave trains and an altered free-surface elevation (also associated with the generation of surface waves) are observed over a wide range flow conditions. Force measurements elucidate how introducing these flow features impacts the forces acting on the hydrofoil, specifically with regards to the generation of lateral forces due to the asymmetric wetting conditions on either side of the hydrofoil. Work is funded by ONR Grant N00014-11-1-0031 and NSF GRFP Grant DGE-1144469.

  11. NASDA's Advanced On-Line System (ADOLIS)

    NASA Technical Reports Server (NTRS)

    Yamamoto, Yoshikatsu; Hara, Hideo; Yamada, Shigeo; Hirata, Nobuyuki; Komatsu, Shigenori; Nishihata, Seiji; Oniyama, Akio

    1993-01-01

    Spacecraft operations including ground system operations are generally realized by various large or small scale group work which is done by operators, engineers, managers, users and so on, and their positions are geographically distributed in many cases. In face-to-face work environments, it is easy for them to understand each other. However, in distributed work environments which need communication media, if only using audio, they become estranged from each other and lose interest in and continuity of work. It is an obstacle to smooth operation of spacecraft. NASDA has developed an experimental model of a new real-time operation control system called 'ADOLIS' (ADvanced On-Line System) adopted to such a distributed environment using a multi-media system dealing with character, figure, image, handwriting, video and audio information which is accommodated to operation systems of a wide range including spacecraft and ground systems. This paper describes the results of the development of the experimental model.

  12. Liquid-bridge breakup in contact-drop dispensing: Liquid-bridge stability with a free contact line.

    PubMed

    Akbari, Amir; Hill, Reghan J; van de Ven, Theo G M

    2015-08-01

    The static stability of weightless liquid bridges with a free contact line with respect to axisymmetric and nonaxisymmetric perturbations is studied. Constant-volume and constant-pressure stability regions are constructed in slenderness versus cylindrical volume diagrams for fixed contact angles. Bifurcations along the stability-region boundaries are characterized by the structure of axisymmetric bridge branches and families of equilibria. A wave-number definition is presented based on the pieces-of-sphere states at branch terminal points to classify equilibrium branches and identify branch connections. Compared with liquid bridges pinned at two equal disks, the free contact line breaks the equatorial and reflective symmetries, affecting the lower boundary of the constant-volume stability region where axisymmetric perturbations are critical. Stability is lost at transcritical bifurcations and turning points along this boundary. Our results furnish the maximum-slenderness stability limit for drop deposition on real surfaces when the contact angle approaches the receding contact angle.

  13. Liquid-bridge breakup in contact-drop dispensing: Liquid-bridge stability with a free contact line

    NASA Astrophysics Data System (ADS)

    Akbari, Amir; Hill, Reghan J.; van de Ven, Theo G. M.

    2015-08-01

    The static stability of weightless liquid bridges with a free contact line with respect to axisymmetric and nonaxisymmetric perturbations is studied. Constant-volume and constant-pressure stability regions are constructed in slenderness versus cylindrical volume diagrams for fixed contact angles. Bifurcations along the stability-region boundaries are characterized by the structure of axisymmetric bridge branches and families of equilibria. A wave-number definition is presented based on the pieces-of-sphere states at branch terminal points to classify equilibrium branches and identify branch connections. Compared with liquid bridges pinned at two equal disks, the free contact line breaks the equatorial and reflective symmetries, affecting the lower boundary of the constant-volume stability region where axisymmetric perturbations are critical. Stability is lost at transcritical bifurcations and turning points along this boundary. Our results furnish the maximum-slenderness stability limit for drop deposition on real surfaces when the contact angle approaches the receding contact angle.

  14. Advanced Nacelle Acoustic Lining Concepts Development

    NASA Technical Reports Server (NTRS)

    Bielak, G.; Gallman, J.; Kunze, R.; Murray, P.; Premo, J.; Kosanchick, M.; Hersh, A.; Celano, J.; Walker, B.; Yu, J.; Parrott, Tony L. (Technical Monitor)

    2002-01-01

    The work reported in this document consisted of six distinct liner technology development subtasks: 1) Analysis of Model Scale ADP Fan Duct Lining Data (Boeing): An evaluation of an AST Milestone experiment to demonstrate 1995 liner technology superiority relative to that of 1992 was performed on 1:5.9 scale model fan rig (Advanced Ducted Propeller) test data acquired in the NASA Glenn 9 x 15 foot wind tunnel. The goal of 50% improvement was deemed satisfied. 2) Bias Flow Liner Investigation (Boeing, VCES): The ability to control liner impedance by low velocity bias flow through liner was demonstrated. An impedance prediction model to include bias flow was developed. 3) Grazing Flow Impedance Testing (Boeing): Grazing flow impedance tests were conducted for comparison with results achieved at four different laboratories. 4) Micro-Perforate Acoustic Liner Technology (BFG, HAE, NG): Proof of concept testing of a "linear liner." 5) Extended Reaction Liners (Boeing, NG): Bandwidth improvements for non-locally reacting liner were investigated with porous honeycomb core test liners. 6) Development of a Hybrid Active/Passive Lining Concept (HAE): Synergism between active and passive attenuation of noise radiated by a model inlet was demonstrated.

  15. Advances in Non-Contact Measurement of Creep Properties

    NASA Technical Reports Server (NTRS)

    Hyers, Robert; Canepari, Stacy; White, Erica Bischoff; Cretegny, Laurent; Rogers, jan

    2009-01-01

    As the required service temperatures for superalloys increases, so do the demands on testing for development of these alloys. Non-contact measurement of creep of refractory metals using electrostatic levitation has been demonstrated at temperatures up to 2300 C using samples of only 20-40 mg. These measurements load the spherical specimen by inertial forces due to rapid rotation. However, the first measurements relied on photon pressure to accelerate the samples to the high rotational rates of thousands of rotations per second, limiting the applicability to low stresses and high temperatures. Recent advances in this area extend this measurement to higher stresses and lower-temperatures through the use of an induction motor to drive the sample to such high rotational speeds. Preliminary results on new measurements on new materials will be presented.

  16. Coupling between precipitation and contact-line dynamics: multiring stains and stick-slip motion.

    PubMed

    Maheshwari, Siddharth; Zhang, Lu; Zhu, Yingxi; Chang, Hsueh-Chia

    2008-02-01

    The contact line in an evaporating drop can stay pinned to form a single ring or can shrink in a discontinuous stepwise manner and generate multiple rings. We demonstrate the latter with DNA solutions and attribute it to a pinning-depinning cycle that generates new contact lines. The new contact line recedes after depinning and is repinned at an internal precipitate ring that determines the location of the next contact line. Each precursor ring is formed when DNAs are trapped by an internal microstagnation flow and precipitation dynamics hence control this unsteady drop motion.

  17. Study of the advancing and receding contact angles: liquid sorption as a cause of contact angle hysteresis.

    PubMed

    Lam, C N C; Wu, R; Li, D; Hair, M L; Neumann, A W

    2002-02-25

    Two types of experiments were used to study the behavior of both advancing and receding contact angles, namely the dynamic one-cycle contact angle (DOCA) and the dynamic cycling contact angle (DCCA) experiments. For the preliminary study, DOCA measurements of different liquids on different solids were performed using an automated axisymmetric drop shape analysis-profile (ADSA-P). From these experimental results, four patterns of receding contact angle were observed: (1) time-dependent receding contact angle; (2) constant receding contact angle; (3) 'stick/slip'; (4) no receding contact angle. For the purpose of illustration, results from four different solid surfaces are shown. These solids are: FC-732-coated surface; poly(methyl methacrylate/n-butyl methacrylate) [P(MMA/nBMA)]; poly(lactic acid) (DL-PLA); and poly(lactic/glycolic acid) 50/50 (DL-PLGA 50/50). Since most of the surfaces in our studies exhibit time dependence in the receding contact angle, a more extended study was conducted using only FC-732-coated surfaces to better understand the possible causes of decreasing receding contact angle and contact angle hysteresis. Contact angle measurements of 21 liquids from two homologous series (i.e. n-alkanes and 1-alcohols) and octamethylcyclotetrasiloxane (OCMTS) on FC-732-coated surfaces were performed. It is apparent that the contact angle hysteresis decreases with the chain length of the liquid. It was found that the receding contact angle equals the advancing angle when the alkane molecules are infinitely large. These results strongly suggest that the chain length and size of the liquid molecule could contribute to contact angle hysteresis phenomena. Furthermore, DCCA measurements of six liquids from the two homologous series on FC-732-coated surfaces were performed. With these experimental results, one can construe that the time dependence of contact angle hysteresis on relatively smooth and homogeneous surfaces is mainly caused by liquid retention

  18. Contact-line friction of liquid drops on self-assembled monolayers: chain-length effects.

    PubMed

    Voué, M; Rioboo, R; Adao, M H; Conti, J; Bondar, A I; Ivanov, D A; Blake, T D; De Coninck, J

    2007-04-24

    The static and dynamic wetting properties of self-assembled alkanethiol monolayers of increasing chain length were studied. The molecular-kinetic theory of wetting was used to interpret the dynamic contact angle data and evaluate the contact-line friction on the microscopic scale. Although the surfaces had a similar static wettability, the coefficient of contact-line friction zeta0 increased linearly with alkyl chain length. This result supports the hypothesis of energy dissipation due to a local deformation of the nanometer-thick layer at the contact line.

  19. Numerical analysis of contact line dynamics passing over a single wettable defect on a wall

    NASA Astrophysics Data System (ADS)

    Yamamoto, Yasufumi; Higashida, Shohei; Tanaka, Hiroyuki; Wakimoto, Tatsuro; Ito, Takahiro; Katoh, Kenji

    2016-08-01

    In this study, the dynamics of a contact line passing a single defect, which was represented by a locally wettable part (whose static contact angle is less than the other part, namely, chemically heterogeneous and physically flat part), was analyzed using numerical simulations employing the front-tracking method and the generalized Navier boundary condition. We observed that the contact line was distorted with a logarithmic shape far from the defect; however, the distortion was dependent on the wall velocity. The apparent (averaged) dynamic contact angle of the wall with a defect was evaluated using a macroscopic energy balance. The apparent dynamic contact angles estimated from the energy balance agree well with the arithmetic averaged angles obtained from the present simulations. The macroscopic energy balance is useful to consider the effect of heterogeneity or roughness of the wall on the relation between the dynamic contact angle and contact line speed.

  20. Modeling of Two-Phase Immiscible Flow with Moving Contact Lines

    NASA Astrophysics Data System (ADS)

    Abu Alsaud, Moataz; Soulaine, Cyprien; Riaz, Amir; Tchelepi, Hamdi; Stanford University Collaboration; University of Maryland, College Park Collaboration

    2015-11-01

    A new numerical method based on the implicit interface approach on Cartesian grids is proposed for modeling two-phase immiscible flow with moving contact lines. The reinitialization of level-set function by computing the minimum distance to linearly reconstructed interface to obtain signed distance function is extended to include the contact angle boundary condition. The physics of contact line dynamics is implemented using the Cox-Voinov hydrodynamic theory that efficiently captures the effect of the microscopic contact line region. The numerical method is validated through various examples. Parasitic currents are studied in the case of static and constantly advected parabolic interface intersecting the domain boundary with an imposed contact angle. Moving contact line in the viscous dominated regime is studied and verified through comparison with experiments.

  1. Thermal singularity and contact line motion in pool boiling: Effects of substrate wettability.

    PubMed

    Taylor, M T; Qian, Tiezheng

    2016-03-01

    The dynamic van der Waals theory [Phys. Rev. E 75, 036304 (2007)] is employed to model the growth of a single vapor bubble in a superheated liquid on a flat homogeneous substrate. The bubble spreading dynamics in the pool boiling regime has been numerically investigated for one-component van der Waals fluids close to the critical point, with a focus on the effect of the substrate wettability on bubble growth and contact line motion. The substrate wettability is found to control the apparent contact angle and the rate of bubble growth (the rate of total evaporation), through which the contact line speed is determined. An approximate expression is derived for the contact line speed, showing good agreement with the simulation results. This demonstrates that the contact line speed is primarily governed by (1) the circular shape of interface (for slow bubble growth), (2) the constant apparent contact angle, and (3) the constant bubble growth rate. It follows that the contact line speed has a sensitive dependence on the substrate wettability via the apparent contact angle which also determines the bubble growth rate. Compared to hydrophilic surfaces, hydrophobic surfaces give rise to a thinner shape of bubble and a higher rate of total evaporation, which combine to result in a much faster contact line speed. This can be linked to the earlier formation of a vapor film and hence the onset of boiling crisis.

  2. Thermal singularity and contact line motion in pool boiling: Effects of substrate wettability

    NASA Astrophysics Data System (ADS)

    Taylor, M. T.; Qian, Tiezheng

    2016-03-01

    The dynamic van der Waals theory [Phys. Rev. E 75, 036304 (2007), 10.1103/PhysRevE.75.036304] is employed to model the growth of a single vapor bubble in a superheated liquid on a flat homogeneous substrate. The bubble spreading dynamics in the pool boiling regime has been numerically investigated for one-component van der Waals fluids close to the critical point, with a focus on the effect of the substrate wettability on bubble growth and contact line motion. The substrate wettability is found to control the apparent contact angle and the rate of bubble growth (the rate of total evaporation), through which the contact line speed is determined. An approximate expression is derived for the contact line speed, showing good agreement with the simulation results. This demonstrates that the contact line speed is primarily governed by (1) the circular shape of interface (for slow bubble growth), (2) the constant apparent contact angle, and (3) the constant bubble growth rate. It follows that the contact line speed has a sensitive dependence on the substrate wettability via the apparent contact angle which also determines the bubble growth rate. Compared to hydrophilic surfaces, hydrophobic surfaces give rise to a thinner shape of bubble and a higher rate of total evaporation, which combine to result in a much faster contact line speed. This can be linked to the earlier formation of a vapor film and hence the onset of boiling crisis.

  3. Models of adsorption at a line of three-phase contact.

    PubMed

    Widom, B

    2006-11-09

    Two model density distributions at a line of three-phase contact for which the adsorptions are readily calculated are analyzed. One of them provides a numerical illustration of a recently found surprising fact about the thermodynamics of adsorption at such contact lines. A form of the line analogue of the Gibbs adsorption equation is conjectured, and it is noted that the conjecture is in principle testable by computer simulation and by experiment.

  4. Direct determination of three-phase contact line properties on nearly molecular scale

    SciTech Connect

    Winkler, P. M.; McGraw, R. L.; Bauer, P. S.; Rentenberger, C.; Wagner, P. E.

    2016-05-17

    Wetting phenomena in multi-phase systems govern the shape of the contact line which separates the different phases. For liquids in contact with solid surfaces wetting is typically described in terms of contact angle. While in macroscopic systems the contact angle can be determined experimentally, on the molecular scale contact angles are hardly accessible. Here we report the first direct experimental determination of contact angles as well as contact line curvature on a scale of the order of 1nm. For water nucleating heterogeneously on Ag nanoparticles we find contact angles around 15 degrees compared to 90 degrees for the corresponding macroscopically measured equilibrium angle. The obtained microscopic contact angles can be attributed to negative line tension in the order of –10–10 J/m that becomes increasingly dominant with increasing curvature of the contact line. Furthermore, these results enable a consistent theoretical description of heterogeneous nucleation and provide firm insight to the wetting of nanosized objects.

  5. Direct determination of three-phase contact line properties on nearly molecular scale

    DOE PAGES

    Winkler, P. M.; McGraw, R. L.; Bauer, P. S.; ...

    2016-05-17

    Wetting phenomena in multi-phase systems govern the shape of the contact line which separates the different phases. For liquids in contact with solid surfaces wetting is typically described in terms of contact angle. While in macroscopic systems the contact angle can be determined experimentally, on the molecular scale contact angles are hardly accessible. Here we report the first direct experimental determination of contact angles as well as contact line curvature on a scale of the order of 1nm. For water nucleating heterogeneously on Ag nanoparticles we find contact angles around 15 degrees compared to 90 degrees for the corresponding macroscopicallymore » measured equilibrium angle. The obtained microscopic contact angles can be attributed to negative line tension in the order of –10–10 J/m that becomes increasingly dominant with increasing curvature of the contact line. Furthermore, these results enable a consistent theoretical description of heterogeneous nucleation and provide firm insight to the wetting of nanosized objects.« less

  6. Thoughts on some outstanding issues in the physics of equilibrium wetting and conceptual understanding of contact lines

    NASA Astrophysics Data System (ADS)

    Sefiane, K.

    2011-08-01

    Equilibrium wetting is a fundamental phenomenon, relevant to many scientific areas. Since the pioneering work on equilibrium wetting of Thomas Young (1805) [1], researchers strived to advance our understanding of this fundamental problem. Despite its apparent simplicity, equilibrium wetting phenomenon still holds many unanswered questions and represents a challenge to modern physicists and engineers. The relationship between quantities amenable to measurements, like macroscopic wetting contact angle, and other surface ener- gies and physical properties remains to be fully elucidated. Wetting is a physical problem which spans over two length scales, inner region ("microscopic") length scale and outer region ("macroscopic"). The three-phase contact line, where the macroscopic region meets the micro- scopic one, and underlying surface forces, represents a challenge to fully understand and model. In this paper, a brief review of the basics of wetting and existing concepts is first presented. Then two important questions are discussed in the light of the latest experimental findings: first the relevance of the continuum concept when describing interfaces near the three-phase contact line, and second the effect of adsorption on interfacial energies and its use to explain some interesting observations like the dependence of equilibrium contact angle on pressure and size of droplets. These recent observations raise some fundamental questions about how the three-phase contact line is conceptualised.

  7. Nanoscale measurement of apparent slip velocity near a moving contact line

    NASA Astrophysics Data System (ADS)

    Park, Joonsik; Breuer, Kenneth; Brown University Team

    2016-11-01

    We report the nanoscale flow measurements within tens of microns from a moving contact line on hydrophobic substrates. A moving contact line was generated using a liquid bridge instability induced by retreating syringe. Contact line speeds ranging from 0.15 to 3 mm/s were recorded. The motions of tracer nanoparticles were measured using two independent experimental techniques: multi-layer flood illumination and Total Internal Reflection Fluorescence Microscopy. The flow field was derived using a novel probabilistic particle tracking velocimetry, which allows the accurate estimation of the rapidly changing flow field near a contact line without bias due to binning or fitting. The results confirm that for distances larger than a few microns from the contact line, the velocity field scales with the instantaneous contact line speed and agrees well with the corner flow solution predicted by the biharmonic equation. A significant slip velocity is shown to exist close to the contact line, decaying rapidly within a few microns. The authors gratefully acknowledge the National Science Foundation, Grants CBET 0854148 and CBET 106614, for the support of this research.

  8. Colloid retention at the meniscus-wall contact line in an open microchannel.

    PubMed

    Zevi, Yuniati; Gao, Bin; Zhang, Wei; Morales, Verónica L; Cakmak, M Ekrem; Medrano, Evelyn A; Sang, Wenjing; Steenhuis, Tammo S

    2012-02-01

    Colloid retention mechanisms in partially saturated porous media are currently being researched with an array of visualization techniques. These visualization techniques have refined our understanding of colloid movement and retention at the pore scale beyond what can be obtained from breakthrough experiments. One of the remaining questions is what mechanisms are responsible for colloid immobilization at the triple point where air, water, and soil grain meet. The objective of this study was to investigate how colloids are transported to the air-water-solid (AWS) contact line in an open triangular microchannel, and then retained as a function of meniscus contact angle with the wall and solution ionic strength. Colloid flow path, meniscus shape and meniscus-wall contact angle, and colloid retention at the AWS contact line were visualized and quantified with a confocal microscope. Experimental results demonstrated that colloid retention at the AWS contact line was significant when the meniscus-wall contact angle was less than 16°, but was minimal for the meniscus-wall contact angles exceeding 20°. Tracking of individual colloids and computational hydrodynamic simulation both revealed that for small contact angles (e.g., 12.5°), counter flow and flow vortices formed near the AWS contact line, but not for large contact angles (e.g., 28°). This counter flow helped deliver the colloids to the wall surface just below the contact line. In accordance with DLVO and hydrodynamic torque calculations, colloid movement may be stopped when the colloid reached the secondary minimum at the wall near the contact line. However, contradictory to the prediction of the torque analysis, colloid retention at the AWS contact line decreased with increasing ionic strength for contact angles of 10-20°, indicating that the air-water interface was involved through both counter flow and capillary force. We hypothesized that capillary force pushed the colloid through the primary energy

  9. Using Nonlinearity and Contact Lines to Control Fluid Flow in Microgravity

    NASA Technical Reports Server (NTRS)

    Perlin, M.; Schultz, W. W.; Bian, X.; Agarwal, M.

    2002-01-01

    Slug flows in a tube are affected by surface tension and contact lines, especially under microgravity. Numerical analyses and experiments are conducted of slug flows in small-diameter tubes with horizontal, inclined and vertical orientations. A PID-controlled, meter-long platform capable of following specified motions is used. An improved understanding of the contact line boundary condition for steady and unsteady contact-line motion is expected. Lastly, a direct fluid-handling method using nonlinear oscillatory motion of a tube is presented.

  10. Defects at the Nanoscale Impact Contact Line Motion at all Scales

    NASA Astrophysics Data System (ADS)

    Perrin, Hugo; Andreotti, Bruno; Lhermerout, Romain; Davitt, Kristina; Rolley, Etienne; Wetting; Nuclation Team; PMMH Team

    2016-11-01

    The contact angle of a liquid drop moving on a real solid surface depends on the speed and direction of motion of the three-phase contact line. Many experiments have demonstrated that pinning on surface defects, thermal activation and viscous dissipation impact contact line dynamics, but so far efforts have failed to disentangle the role of each of these dissipation channels. Here, we propose a unifying multi-scale approach that provides a single quantitative framework. We use this approach to successfully account for the dynamics measured in a classic dip-coating experiment performed over a unprecedentedly wide range of velocity. We show that the full contact line dynamics up to the liquid film entrainment threshold can be parametrized by the size, amplitude and density of nanometer-scale defects. This leads us to reinterpret the contact angle hysteresis as a dynamical cross-over rather than a depinning transition. ANR SMART and REALWET.

  11. Defects at the Nanoscale Impact Contact Line Motion at all Scales

    NASA Astrophysics Data System (ADS)

    Perrin, Hugo; Lhermerout, Romain; Davitt, Kristina; Rolley, Etienne; Andreotti, Bruno

    2016-05-01

    The contact angle of a liquid drop moving on a real solid surface depends on the speed and direction of motion of the three-phase contact line. Many experiments have demonstrated that pinning on surface defects, thermal activation and viscous dissipation impact contact line dynamics, but so far, efforts have failed to disentangle the role of each of these dissipation channels. Here, we propose a unifying multiscale approach that provides a single quantitative framework. We use this approach to successfully account for the dynamics measured in a classic dip-coating experiment performed over an unprecedentedly wide range of velocity. We show that the full contact line dynamics up to the liquid film entrainment threshold can be parametrized by the size, amplitude and density of nanometer-scale defects. This leads us to reinterpret the contact angle hysteresis as a dynamical crossover rather than a depinning transition.

  12. Defects at the Nanoscale Impact Contact Line Motion at all Scales.

    PubMed

    Perrin, Hugo; Lhermerout, Romain; Davitt, Kristina; Rolley, Etienne; Andreotti, Bruno

    2016-05-06

    The contact angle of a liquid drop moving on a real solid surface depends on the speed and direction of motion of the three-phase contact line. Many experiments have demonstrated that pinning on surface defects, thermal activation and viscous dissipation impact contact line dynamics, but so far, efforts have failed to disentangle the role of each of these dissipation channels. Here, we propose a unifying multiscale approach that provides a single quantitative framework. We use this approach to successfully account for the dynamics measured in a classic dip-coating experiment performed over an unprecedentedly wide range of velocity. We show that the full contact line dynamics up to the liquid film entrainment threshold can be parametrized by the size, amplitude and density of nanometer-scale defects. This leads us to reinterpret the contact angle hysteresis as a dynamical crossover rather than a depinning transition.

  13. Numerical approximations for a phase-field moving contact line model with variable densities and viscosities

    NASA Astrophysics Data System (ADS)

    Yu, Haijun; Yang, Xiaofeng

    2017-04-01

    We consider the numerical approximations of a two-phase hydrodynamics coupled phase-field model that incorporates the variable densities, viscosities and moving contact line boundary conditions. The model is a nonlinear, coupled system that consists of incompressible Navier-Stokes equations with the generalized Navier boundary condition, and the Cahn-Hilliard equations with moving contact line boundary conditions. By some subtle explicit-implicit treatments to nonlinear terms, we develop two efficient, unconditionally energy stable numerical schemes, in particular, a linear decoupled energy stable scheme for the system with static contact line condition, and a nonlinear energy stable scheme for the system with dynamic contact line condition. An efficient spectral-Galerkin spatial discretization is implemented to verify the accuracy and efficiency of proposed schemes. Various numerical results show that the proposed schemes are efficient and accurate.

  14. Particle trap to sheath contact for a gas-insulated transmission line having a corrugated outer conductor

    DOEpatents

    Fischer, William H.; Cookson, Alan H.; Yoon, Kue H.

    1984-04-10

    A particle trap to outer elongated conductor or sheath contact for gas-insulated transmission lines. The particle trap to outer sheath contact of the invention is applicable to gas-insulated transmission lines having either corrugated or non-corrugated outer sheaths. The contact of the invention includes an electrical contact disposed on a lever arm which in turn is rotatably disposed on the particle trap and biased in a direction to maintain contact between the electrical contact and the outer sheath.

  15. Droplet spreading on rough surfaces: Tackling the contact line boundary condition

    NASA Astrophysics Data System (ADS)

    Chamakos, Nikolaos T.; Kavousanakis, Michail E.; Boudouvis, Andreas G.; Papathanasiou, Athanasios G.

    2016-02-01

    The complicated dynamics of the contact line of a moving droplet on a solid substrate often hamper the efficient modeling of microfluidic systems. In particular, the selection of the effective boundary conditions, specifying the contact line motion, is a controversial issue since the microscopic physics that gives rise to this displacement is still unknown. Here, a sharp interface, continuum-level, novel modeling approach, accounting for liquid/solid micro-scale interactions assembled in a disjoining pressure term, is presented. By following a unified conception (the model applies both to the liquid/solid and the liquid/ambient interfaces), the friction forces at the contact line, as well as the dynamic contact angle are derived implicitly as a result of the disjoining pressure and viscous effects interplay in the vicinity of the substrate's intrinsic roughness. Previous hydrodynamic model limitations, of imposing the contact line boundary condition to an unknown number and reconfigurable contact lines, when modeling the spreading dynamics on textured substrates, are now overcome. The validity of our approach is tested against experimental data of a droplet impacting on a horizontal solid surface. The study of the early spreading stage on hierarchically structured and chemically patterned solid substrates reveal an inertial regime where the contact radius grows according to a universal power law, perfectly agreeing with recently published experimental findings.

  16. Contact line pinning favors the mass production of monodisperse microbubbles.

    NASA Astrophysics Data System (ADS)

    Gordillo, Jose Manuel; Campo-Cortes, Francisco; Riboux, Guillaume

    2015-11-01

    A robust method for the generation of phospholipid covered monodisperse microbubbles of diameters ~10 microns at production rates exceeding 0.1 MHz, is presented here. We show that bubbles are periodically formed from the tip of a long and thin gas ligament stabilized thanks to both the strong favorable pressure gradient existing at the entrance region of a long rectangular PDMS-PDMS channel and to the pinning of the gas-liquid interface at a centered groove of several microns width placed on one of its walls. Moreover, the long exit channel incorporated in our design, favors the transport of phospholipid molecules towards the gas-liquid interface. Our experiments show that the resulting phospholipid shell inhibit both the diffusion of the gas in the surrounding liquid as well as the coalescence between contacting bubbles. These evidences indicate that the proposed method is suitable for the generation of monodisperse microbubbles for diagnosis or therapeutical applications.

  17. Advances in contact algorithms and their application to tires

    NASA Technical Reports Server (NTRS)

    Noor, Ahmed K.; Tanner, John A.

    1988-01-01

    Currently used techniques for tire contact analysis are reviewed. Discussion focuses on the different techniques used in modeling frictional forces and the treatment of contact conditions. A status report is presented on a new computational strategy for the modeling and analysis of tires, including the solution of the contact problem. The key elements of the proposed strategy are: (1) use of semianalytic mixed finite elements in which the shell variables are represented by Fourier series in the circumferential direction and piecewise polynomials in the meridional direction; (2) use of perturbed Lagrangian formulation for the determination of the contact area and pressure; and (3) application of multilevel iterative procedures and reduction techniques to generate the response of the tire. Numerical results are presented to demonstrate the effectiveness of a proposed procedure for generating the tire response associated with different Fourier harmonics.

  18. Advances in reduction techniques for tire contact problems

    NASA Technical Reports Server (NTRS)

    Noor, Ahmed K.

    1995-01-01

    Some recent developments in reduction techniques, as applied to predicting the tire contact response and evaluating the sensitivity coefficients of the different response quantities, are reviewed. The sensitivity coefficients measure the sensitivity of the contact response to variations in the geometric and material parameters of the tire. The tire is modeled using a two-dimensional laminated anisotropic shell theory with the effects of variation in geometric and material parameters, transverse shear deformation, and geometric nonlinearities included. The contact conditions are incorporated into the formulation by using a perturbed Lagrangian approach with the fundamental unknowns consisting of the stress resultants, the generalized displacements, and the Lagrange multipliers associated with the contact conditions. The elemental arrays are obtained by using a modified two-field, mixed variational principle. For the application of reduction techniques, the tire finite element model is partitioned into two regions. The first region consists of the nodes that are likely to come in contact with the pavement, and the second region includes all the remaining nodes. The reduction technique is used to significantly reduce the degrees of freedom in the second region. The effectiveness of the computational procedure is demonstrated by a numerical example of the frictionless contact response of the space shuttle nose-gear tire, inflated and pressed against a rigid flat surface. Also, the research topics which have high potential for enhancing the effectiveness of reduction techniques are outlined.

  19. Molecular origin of contact line stick-slip motion during droplet evaporation

    PubMed Central

    Wang, FengChao; Wu, HengAn

    2015-01-01

    Understanding and controlling the motion of the contact line is of critical importance for surface science studies as well as many industrial engineering applications. In this work, we elucidate the molecular origin of contact line stick-slip motion during the evaporation of liquid droplets on flexible nano-pillared surfaces using molecular dynamics simulations. We demonstrate that the evaporation-induced stick-slip motion of the contact line is a consequence of competition between pinning and depinning forces. Furthermore, the tangential force exerted by the pillared substrate on the contact line was observed to have a sawtooth-like oscillation. Our analysis also establishes that variations in the pinning force are accomplished through the self-adaptation of solid-liquid intermolecular distances, especially for liquid molecules sitting directly on top of the solid pillar. Consistent with our theoretical analysis, molecular dynamics simulations also show that the maximum pinning force is quantitatively related to both solid-liquid adhesion strength and liquid-vapor surface tension. These observations provide a fundamental understanding of contact line stick-slip motion on pillared substrates and also give insight into the microscopic interpretations of contact angle hysteresis, wetting transitions and dynamic spreading. PMID:26628084

  20. Molecular origin of contact line stick-slip motion during droplet evaporation

    NASA Astrophysics Data System (ADS)

    Wang, Fengchao; Wu, Hengan

    2015-12-01

    Understanding and controlling the motion of the contact line is of critical importance for surface science studies as well as many industrial engineering applications. In this work, we elucidate the molecular origin of contact line stick-slip motion during the evaporation of liquid droplets on flexible nano-pillared surfaces using molecular dynamics simulations. We demonstrate that the evaporation-induced stick-slip motion of the contact line is a consequence of competition between pinning and depinning forces. Furthermore, the tangential force exerted by the pillared substrate on the contact line was observed to have a sawtooth-like oscillation. Our analysis also establishes that variations in the pinning force are accomplished through the self-adaptation of solid-liquid intermolecular distances, especially for liquid molecules sitting directly on top of the solid pillar. Consistent with our theoretical analysis, molecular dynamics simulations also show that the maximum pinning force is quantitatively related to both solid-liquid adhesion strength and liquid-vapor surface tension. These observations provide a fundamental understanding of contact line stick-slip motion on pillared substrates and also give insight into the microscopic interpretations of contact angle hysteresis, wetting transitions and dynamic spreading.

  1. Molecular origin of contact line stick-slip motion during droplet evaporation.

    PubMed

    Wang, FengChao; Wu, HengAn

    2015-12-02

    Understanding and controlling the motion of the contact line is of critical importance for surface science studies as well as many industrial engineering applications. In this work, we elucidate the molecular origin of contact line stick-slip motion during the evaporation of liquid droplets on flexible nano-pillared surfaces using molecular dynamics simulations. We demonstrate that the evaporation-induced stick-slip motion of the contact line is a consequence of competition between pinning and depinning forces. Furthermore, the tangential force exerted by the pillared substrate on the contact line was observed to have a sawtooth-like oscillation. Our analysis also establishes that variations in the pinning force are accomplished through the self-adaptation of solid-liquid intermolecular distances, especially for liquid molecules sitting directly on top of the solid pillar. Consistent with our theoretical analysis, molecular dynamics simulations also show that the maximum pinning force is quantitatively related to both solid-liquid adhesion strength and liquid-vapor surface tension. These observations provide a fundamental understanding of contact line stick-slip motion on pillared substrates and also give insight into the microscopic interpretations of contact angle hysteresis, wetting transitions and dynamic spreading.

  2. Derivation of a continuum model and the energy law for moving contact lines with insoluble surfactants

    SciTech Connect

    Zhang, Zhen Xu, Shixin; Ren, Weiqing

    2014-06-15

    A continuous model is derived for the dynamics of two immiscible fluids with moving contact lines and insoluble surfactants based on thermodynamic principles. The continuum model consists of the Navier-Stokes equations for the dynamics of the two fluids and a convection-diffusion equation for the evolution of the surfactant on the fluid interface. The interface condition, the boundary condition for the slip velocity, and the condition for the dynamic contact angle are derived from the consideration of energy dissipations. Different types of energy dissipations, including the viscous dissipation, the dissipations on the solid wall and at the contact line, as well as the dissipation due to the diffusion of surfactant, are identified from the analysis. A finite element method is developed for the continuum model. Numerical experiments are performed to demonstrate the influence of surfactant on the contact line dynamics. The different types of energy dissipations are compared numerically.

  3. Hybrid bearing technology for advanced turbomachinery: Rolling contact fatigue testing

    SciTech Connect

    Dill, J.F.

    1996-01-01

    The purpose of this paper is to describe the basic structure and results to date of a major ARPA funded effort to provide a tribological performance database on ceramic bearing materials and their interaction with standard bearing steels. Program efforts include studies of material physical properties, machining characteristics, and tribological performance. The majority of the testing completed to date focuses on rolling contact fatigue testing of the ceramic materials, including efforts to arrive at optimum approaches to evaluating ceramic/steel hybrid combinations in rolling contact fatigue.

  4. Advanced techniques and painless procedures for nonlinear contact analysis and forming simulation via implicit FEM

    NASA Astrophysics Data System (ADS)

    Zhuang, Shoubing

    2013-05-01

    Nonlinear contact analysis including forming simulation via finite element methods has a crucial and practical application in many engineering fields. However, because of high nonlinearity, nonlinear contact analysis still remains as an extremely challenging obstacle for many industrial applications. The implicit finite element scheme is generally more accurate than the explicit finite element scheme, but it has a known challenge of convergence because of complex geometries, large relative motion and rapid contact state change. It might be thought as a very painful process to diagnose the convergence issue of nonlinear contact. Most complicated contact models have a great many contact surfaces, and it is hard work to well define the contact pairs using the common contact definition methods, which either result in hundreds of contact pairs or are time-consuming. This paper presents the advanced techniques of nonlinear contact analysis and forming simulation via the implicit finite element scheme and the penalty method. The calculation of the default automatic contact stiffness is addressed. Furthermore, this paper presents the idea of selection groups to help easily and efficiently define contact pairs for complicated contact analysis, and the corresponding implementation and usage are discussed. Lastly, typical nonlinear contact models and forming models with nonlinear material models are shown in the paper to demonstrate the key presented method and technologies.

  5. Toward full-chip prediction of yield-limiting contact patterning failure: correlation of simulated image parameters to advanced contact metrology metrics

    NASA Astrophysics Data System (ADS)

    Sturtevant, John L.; Chou, Dyiann

    2006-03-01

    Electrical failure due to incomplete contacts or vias has arisen as one of the primary modes of yield loss for 130 nm and below designs in manufacturing. Such failures are generally understood to arise from both random and systematic sources. The addition of redundant vias, where possible, has long been an accepted DFM practice for mitigating the impact of random defects. Incomplete vias are often characterized by having a diameter near the target dimension but a depth of less than 100% of target. As such, it is a difficult problem to diagnose and debug in-line, since bright and dark field optical inspection systems cannot typically distinguish between a closed, partially open and fully open contact. Advanced metrology systems have emerged in recent years to meet this challenge, but no perfect manufacturing solution has yet been identified for full field verification of all contacts. Voltage Contrast (VC) SEM metrology biases the wafer to directly measure electrical conductivity after fill / polish, and can therefore easily discern a lack of electrical connection to the underlying conductor caused by incomplete photo, etch, or fill processing. While an entire wafer can in principal be VC scanned, throughput limitations dictate very sparse sampling in manufacturing. SEM profile grading (PG) leverages the rich content of the secondary electron waveform to decipher information about the bottom of the contact. Several authors have demonstrated an excellent response of the Profile Grade to intentional defocus vectors. However, the SEM can only target discreet or single digit groupings of contacts, and therefore requires intelligent guidance to identify those contacts which are most prone to failure, enabling protection of the fab WIP. An a-priori knowledge of which specific contacts in a layout are most likely to fail would prove very useful for proactive inspection in manufacturing. Model based pre-manufacturing verification allows for such knowledge to be communicated

  6. Quantifying stick-slip contact line motion of evaporating sessile droplets

    NASA Astrophysics Data System (ADS)

    Wood, Clay; Pye, Justin; Burton, Justin

    Sessile droplet evaporation often involves an apparent stick-slip motion of pinning and de-pinning of the drop's edge. The small forces and complex hydrodynamics at the contact line make this phenomena difficult to quantify, although easily observable. We have characterized the stick-slip motion on gold and glass surfaces with the use of a quartz crystal microbalance (QCM). We observe changes in both the resonant frequency and dissipation during droplet evaporation. Depositing a droplet onto this oscillating surface greatly decreases the frequency while the dissipation increases. Evaporation occurs in two stages; when the droplet's contact line is pinned to the surface, its contact angle decreases. Then, at a critical angle, the contact line is pulled over pinning points and continues to evaporate with a receding contact area. These stick-slip events appear in our data as a sharp increase in frequency, followed by a sharp decrease; simultaneously, the dissipation displays a single sharp peak. QCMs pre-cleaned in an oxygen plasma environment exhibited a significantly reduced occurrence and magnitude of these features. We interpret these features and quantify the forces involved in the stick-slip motion using a dynamic model of the QCM with additional surface forces at the contact line.

  7. Towards a more accurate microscopic description of the moving contact line problem - incorporating nonlocal effects through a statistical mechanics framework

    NASA Astrophysics Data System (ADS)

    Nold, Andreas; Goddard, Ben; Sibley, David; Kalliadasis, Serafim

    2014-03-01

    Multiscale effects play a predominant role in wetting phenomena such as the moving contact line. An accurate description is of paramount interest for a wide range of industrial applications, yet it is a matter of ongoing research, due to the difficulty of incorporating different physical effects in one model. Important small-scale phenomena are corrections to the attractive fluid-fluid and wall-fluid forces in inhomogeneous density distributions, which often previously have been accounted for by the disjoining pressure in an ad-hoc manner. We systematically derive a novel model for the description of a single-component liquid-vapor multiphase system which inherently incorporates these nonlocal effects. This derivation, which is inspired by statistical mechanics in the framework of colloidal density functional theory, is critically discussed with respect to its assumptions and restrictions. The model is then employed numerically to study a moving contact line of a liquid fluid displacing its vapor phase. We show how nonlocal physical effects are inherently incorporated by the model and describe how classical macroscopic results for the contact line motion are retrieved. We acknowledge financial support from ERC Advanced Grant No. 247031 and Imperial College through a DTG International Studentship.

  8. Contact line extraction and length measurements in model sediments and sedimentary rocks.

    PubMed

    Rodriguez, Elena; Prodanović, Maša; Bryant, Steven L

    2012-02-15

    The mechanisms that govern the transport of colloids in the unsaturated zone of soils are still poorly understood, because of the complexity of processes that occur at pore scale. These mechanisms are of specific interest in quantifying water quality with respect to pathogen transport (e.g. Escherichia coli, Cryptosporidium) between the source (e.g. farms) and human users. Besides straining in pore throats and constrictions of smaller or equivalent size, the colloids can be retained at the interfaces between air, water, and grains. Theories competing to explain this mechanism claim that retention can be caused by adhesion at the air-water-interface (AWI) between sediment grains or by straining at the air-water-solid (AWS) contact line. Currently, there are no established methods for the estimation of pathogen retention in unsaturated media because of the intricate influence of AWI and AWS on transport and retention. What is known is that the geometric configuration and connectivity of the aqueous phase is an important factor in unsaturated transport. In this work we develop a computational method based on level set functions to identify and quantify the AWS contact line (in general the non-wetting-wetting-solid contact line) in any porous material. This is the first comprehensive report on contact line measurement for fluid configurations from both level-set method based fluid displacement simulation and imaged experiments. The method is applicable to any type of porous system, as long as the detailed pore scale geometry is available. We calculated the contact line length in model sediments (packs of spheres) as well as in real porous media, whose geometry is taken from high-resolution images of glass bead packs and sedimentary rocks. We observed a strong dependence of contact line length on the geometry of the sediment grains and the arrangement of the air and water phases. These measurements can help determine the relative contribution of the AWS line to pathogen

  9. A moving contact line as a rheometer for nanometric interfacial layers

    PubMed Central

    Lhermerout, Romain; Perrin, Hugo; Rolley, Etienne; Andreotti, Bruno; Davitt, Kristina

    2016-01-01

    How a liquid drop sits or moves depends on the physical and mechanical properties of the underlying substrate. This can be seen in the hysteresis of the contact angle made by a drop on a solid, which is known to originate from surface heterogeneities, and in the slowing of droplet motion on deformable solids. Here, we show how a moving contact line can be used to characterize a molecularly thin polymer layer on a solid. We find that the hysteresis depends on the polymerization index and can be optimized to be vanishingly small (<0.07°). The mechanical properties are quantitatively deduced from the microscopic contact angle, which is proportional to the speed of the contact line and the Rouse relaxation time divided by the layer thickness, in agreement with theory. Our work opens the prospect of measuring the properties of functionalized interfaces in microfluidic and biomedical applications that are otherwise inaccessible. PMID:27562022

  10. A moving contact line as a rheometer for nanometric interfacial layers

    NASA Astrophysics Data System (ADS)

    Lhermerout, Romain; Perrin, Hugo; Rolley, Etienne; Andreotti, Bruno; Davitt, Kristina

    2016-08-01

    How a liquid drop sits or moves depends on the physical and mechanical properties of the underlying substrate. This can be seen in the hysteresis of the contact angle made by a drop on a solid, which is known to originate from surface heterogeneities, and in the slowing of droplet motion on deformable solids. Here, we show how a moving contact line can be used to characterize a molecularly thin polymer layer on a solid. We find that the hysteresis depends on the polymerization index and can be optimized to be vanishingly small (<0.07°). The mechanical properties are quantitatively deduced from the microscopic contact angle, which is proportional to the speed of the contact line and the Rouse relaxation time divided by the layer thickness, in agreement with theory. Our work opens the prospect of measuring the properties of functionalized interfaces in microfluidic and biomedical applications that are otherwise inaccessible.

  11. Interaction of levitating microdroplets with moist air flow in the contact line region

    NASA Astrophysics Data System (ADS)

    Kabov, Oleg; Zaitsev, Dmitry; Kirichenko, Dmitry; Ajaev, Vladimir

    2016-11-01

    Self-organization of levitating microdroplets of condensate over a liquid-gas interface has been observed in several recent experiments involving evaporation at high heat fluxes, although the nature of thin phenomenon is still not completely understood. We conduct experimental investigation of behavior of an ordered array of levitating microdroplets as it approaches a region of intense evaporation near the contact line. Interaction of the array with the local highly non-uniform gas flow is shown to result in the break-up of the pattern. Furthermore, our experimental set-up provides a unique tool for investigation of the Stefan flow originating near the contact line by using microdroplets as tracers. Local gas flow velocities near the contact line are obtained based on trajectories of the droplets. This work was supported by the Russian Science Foundation (Project No. 14-19-01755).

  12. Effect of surface modification on interfacial nanobubble morphology and contact line tension.

    PubMed

    Rangharajan, Kaushik K; Kwak, Kwang J; Conlisk, A T; Wu, Yan; Prakash, Shaurya

    2015-07-14

    Past research has confirmed the existence of surface nanobubbles on various hydrophobic substrates (static contact angle >90°) when imaged in air-equilibrated water. Additionally, the use of solvent exchange techniques (based on the difference in saturation levels of air in various solvents) also introduced surface nanobubbles on hydrophilic substrates (static contact angle <90°). In this work, tapping mode atomic force microscopy was used to image interfacial nanobubbles formed on bulk polycarbonate (static contact angle of 81.1°), bromo-terminated silica (BTS; static contact angle of 85.5°), and fluoro-terminated silica (FTS; static contact angle of 105.3°) surfaces when immersed in air-equilibrated water without solvent exchange. Nanobubbles formed on the above three substrates were characterized on the basis of Laplace pressure, bubble density, and contact line tension. Results reported here show that (1) the Laplace pressures of all nanobubbles formed on both BTS and polycarbonate were an order of magnitude higher than those of FTS, (2) the nanobubble number density per unit area decreased with an increase in substrate contact angle, and (3) the contact line tension of the nanobubbles was calculated to be positive for both BTS and polycarbonate (lateral radius, Rs < 50 nm for all nanobubbles), and negative for FTS (Rs > 50 nm for all nanobubbles). The nanobubble morphology and distribution before and after using the solvent exchange method (ethanol-water), on the bulk polycarbonate substrate was also characterized. Analysis for these polycarbonate surface nanobubbles showed that both the Laplace pressure and nanobubble density reduced by ≈98% after ethanol-water exchange, accompanied by a flip in the magnitude of contact line tension from positive (0.19 nN) to negative (-0.11 nN).

  13. A transmission line method for evaluation of vertical InAs nanowire contacts

    NASA Astrophysics Data System (ADS)

    Berg, M.; Svensson, J.; Lind, E.; Wernersson, L.-E.

    2015-12-01

    In this paper, we present a method for metal contact characterization to vertical semiconductor nanowires using the transmission line method (TLM) on a cylindrical geometry. InAs nanowire resistors are fabricated on Si substrates using a hydrogen silsesquioxane (HSQ) spacer between the bottom and top contact. The thickness of the HSQ is defined by the dose of an electron beam lithography step, and by varying the separation thickness for a group of resistors, a TLM series is fabricated. Using this method, the resistivity and specific contact resistance are determined for InAs nanowires with different doping and annealing conditions. The contacts are shown to improve with annealing at temperatures up to 300 °C for 1 min, with specific contact resistance values reaching down to below 1 Ω µm2.

  14. A transmission line method for evaluation of vertical InAs nanowire contacts

    SciTech Connect

    Berg, M. Svensson, J. Lind, E. Wernersson, L.-E.

    2015-12-07

    In this paper, we present a method for metal contact characterization to vertical semiconductor nanowires using the transmission line method (TLM) on a cylindrical geometry. InAs nanowire resistors are fabricated on Si substrates using a hydrogen silsesquioxane (HSQ) spacer between the bottom and top contact. The thickness of the HSQ is defined by the dose of an electron beam lithography step, and by varying the separation thickness for a group of resistors, a TLM series is fabricated. Using this method, the resistivity and specific contact resistance are determined for InAs nanowires with different doping and annealing conditions. The contacts are shown to improve with annealing at temperatures up to 300 °C for 1 min, with specific contact resistance values reaching down to below 1 Ω µm{sup 2}.

  15. Drop evaporation on superhydrophobic PTFE surfaces driven by contact line dynamics.

    PubMed

    Ramos, S M M; Dias, J F; Canut, B

    2015-02-15

    In the present study, we experimentally study the evaporation modes and kinetics of sessile drops of water on highly hydrophobic surfaces (contact angle ∼160°), heated to temperatures ranging between 40° and 70 °C. These surfaces were initially constructed by means of controlled tailoring of polytetrafluoroethylene (PTFE) substrates. The evaporation of droplets was observed to occur in three distinct phases, which were the same for the different substrate temperatures. The drops started to evaporate in the constant contact radius (CCR) mode, then switched to a more complex mode characterized by a set of stick-slip events accompanied by a decrease in contact angle, and finally shifted to a mixed mode in which the contact radius and contact angle decreased simultaneously until the drops had completely evaporated. It is shown that in the case of superhydrophobic surfaces, the energy barriers (per unit length) associated with the stick-slip motion of a drop ranges in the nJ m(-1) scale. Furthermore, analysis of the evaporation rates, determined from experimental data show that, even in the CCR mode, a linear relationship between V(2/3) and the evaporation time is verified. The values of the evaporation rate constants are found to be higher in the pinned contact line regime (the CCR mode) than in the moving contact line regime. This behavior is attributed to the drop's higher surface to volume ratio in the CCR mode.

  16. Mean-field Density Functional Theory of a Three-Phase Contact Line

    NASA Astrophysics Data System (ADS)

    Lin, Chang-You

    A three-phase contact line in a three-phase fluid system is modeled by a mean-field density functional theory. We use a variational approach to find the Euler-Lagrange equations. Analytic solutions are obtained in the two-phase regions at large distances from the contact line. We employ a triangular grid and use a successive over-relaxation method to find numerical solutions in the entire domain for the special case of equal interfacial tensions for the two-phase interfaces. We use the Kerins-Boiteux formula to obtain a line tension associated with the contact line. This line tension turns out to be negative. We associate line adsorption with the change of line tension as the governing potentials change. We develop a geometrical interpretation to generalize our potential in order to study less symmetric systems as occur in some practical phase diagrams. A set of special cases of this new potential are linear transformations from our original potential. In those special cases, we can obtain solutions by scaling of our former results.

  17. Electrowetting with contact line pinning: Computational modeling and comparisons with experiments

    NASA Astrophysics Data System (ADS)

    Walker, Shawn W.; Shapiro, Benjamin; Nochetto, Ricardo H.

    2009-10-01

    This work describes the modeling and simulation of planar electrowetting on dielectric devices that move fluid droplets by modulating surface tension effects. The fluid dynamics are modeled by Hele-Shaw type equations with a focus on including the relevant boundary phenomena. Specifically, we include contact angle saturation and a contact line force threshold model that can account for hysteresis and pinning effects. These extra boundary effects are needed to make reasonable predictions of the correct shape and time scale of liquid motion. Without them the simulations can predict droplet motion that is much faster than in experiments (up to 10-20 times faster). We present a variational method for our model, and a corresponding finite element discretization, which is able to handle surface tension, conservation of mass, and the nonlinear contact line pinning in a straightforward and numerically robust way. In particular, the contact line pinning is captured by a variational inequality. We note that all the parameters in our model are derived from first principles or from independent experiments except one (the parameter Dvisc that accounts for the extra resistive effect of contact angle hysteresis and is difficult to measure directly). We quantitatively compare our simulation to available experimental data for four different cases of droplet motion that include splitting and joining of droplets and find good agreement with experiments.

  18. Piercing the water surface with a blade: Singularities of the contact line

    SciTech Connect

    Alimov, Mars M.; Kornev, Konstantin G.

    2016-01-15

    An external meniscus on a narrow blade with a slit-like cross section is studied using the hodograph formulation of the Laplace nonlinear equation of capillarity. On narrow blades, the menisci are mostly shaped by the wetting and capillary forces; gravity plays a secondary role. To describe a meniscus in this asymptotic case, the model of Alimov and Kornev [“Meniscus on a shaped fibre: Singularities and hodograph formulation,” Proc. R. Soc. A 470, 20140113 (2014)] has been employed. It is shown that at the sharp edges of the blade, the contact line makes a jump. In the wetting case, the contact line sitting at each side of the blade is lifted above the points where the meniscus first meets the blade edges. In the non-wetting case, the contact line is lowered below these points. The contours of the constant height emanating from the blade edges generate unusual singularities with infinite curvatures at some points at the blade edges. The meniscus forms a unique surface made of two mirror-symmetric sheets fused together. Each sheet is supported by the contact line sitting at each side of the blade.

  19. Piercing the water surface with a blade: Singularities of the contact line

    NASA Astrophysics Data System (ADS)

    Alimov, Mars M.; Kornev, Konstantin G.

    2016-01-01

    An external meniscus on a narrow blade with a slit-like cross section is studied using the hodograph formulation of the Laplace nonlinear equation of capillarity. On narrow blades, the menisci are mostly shaped by the wetting and capillary forces; gravity plays a secondary role. To describe a meniscus in this asymptotic case, the model of Alimov and Kornev ["Meniscus on a shaped fibre: Singularities and hodograph formulation," Proc. R. Soc. A 470, 20140113 (2014)] has been employed. It is shown that at the sharp edges of the blade, the contact line makes a jump. In the wetting case, the contact line sitting at each side of the blade is lifted above the points where the meniscus first meets the blade edges. In the non-wetting case, the contact line is lowered below these points. The contours of the constant height emanating from the blade edges generate unusual singularities with infinite curvatures at some points at the blade edges. The meniscus forms a unique surface made of two mirror-symmetric sheets fused together. Each sheet is supported by the contact line sitting at each side of the blade.

  20. Singularities in Contact line Motion: From molecular simulations to continuum theories

    NASA Astrophysics Data System (ADS)

    Denniston, Colin

    2005-03-01

    When the contact line at the intersection between a fluid interface and a solid moves, traditional continuum calculations predict a diverging dissipation. Experiments and continuum theories cannot reveal how this singularity is removed, but proposals are based on very different mechanisms: Shear-induced slip or diffusive transport. We present detailed molecular simulations and atomistically-derived mesoscale models [1] of contact line motion in the conditions assumed for diffusive models [2]. The singularity is primarily eliminated by slip, but there is a Marangoni-like contribution to slip that has not been observed previously. Diffusion is present, but perpendicular to the expected direction. We also find an interesting dynamic dewetting transition at a finite dynamic contact angle. [1] C. Denniston and M.O. Robbins, PRL 87, 178302 (2001); ibid, PRE 69, 021505 (2004). [2] H.-Y. Chen, D. Jasnow, J. Vinals, PRL 85, 1686 (2000).

  1. Joint line elevation in revision TKA leads to increased patellofemoral contact forces.

    PubMed

    König, Christian; Sharenkov, Alexey; Matziolis, Georg; Taylor, William R; Perka, Carsten; Duda, Georg N; Heller, Markus O

    2010-01-01

    One difficulty in revision total knee arthroplasty (TKA) is the management of distal femoral bone defects in which a joint line elevation (JLE) is likely to occur. Although JLE has been associated with inferior clinical results, the effect that an elevated joint line has on knee contact forces has not been investigated. To understand the clinical observations and elaborate the potential risk associated with a JLE, we performed a virtual TKA on the musculoskeletal models of four subjects. Tibio- and patellofemoral joint contact forces (JCF) were calculated for walking and stair climbing, varying the location of the joint line. An elevation of the joint line primarily affected the patellofemoral joint with JCF increases of as much as 60% of the patient's body weight (BW) at 10-mm JLE and 90% BW at 15-mm JLE, while the largest increase in tibiofemoral JCF was only 14% BW. This data demonstrates the importance of restoring the joint line, as it plays a critical role for the magnitudes of the JCFs, particularly for the patellofemoral joint. JLE caused by managing distal femoral defects with downsizing and proximalizing the femoral component could increase the patellofemoral contact forces, and may be a contributing factor to postoperative complications such as pain, polyethylene wear, and limited function.

  2. Clinical Performance of Toris K Contact Lens in Patients with Moderate to Advanced Keratoconus: A Real Life Retrospective Analysis

    PubMed Central

    Yilmaz, Ihsan; Ozcelik, Ferah; Basarir, Berna; Demir, Gokhan; Durusoy, Gonul; Taskapili, Muhittin

    2016-01-01

    Objectives. To evaluate the visual performance of Toris K soft contact lenses in patients with moderate-to-advanced keratoconus and also to compare the results according to cone types, cone location, and severity of keratoconus. Materials and Methods. Sixty eyes of 40 participants were included in this retrospective study. Uncorrected visual acuity (UCVA), best-spectacle corrected visual acuity (BCVA), best-contact lens corrected visual acuity (BCLCVA), and comfort rating via visual analogue scales (VAS) were measured. Results. The mean age was 27.3 ± 8.6 years (range: 18 to 54). The mean logMAR UCVA, BCVA, and BCLCVA were 0.85 ± 0.38 (range: 0.30–1.30), 0.47 ± 0.27 (range: 0.10–1.30), and 0.16 ± 0.20 (range: 0–1.00). There were significant increases in visual acuities with contact lenses (p < .05). BCLCVA was significantly better in oval type than globus type (p = .022). UCVA and BCLCVA were significantly better in moderate keratoconus group (p = .015, p = .018). The mean line gain in Snellen was 3.6 ± 1.8 lines (range: 0–7 lines). The mean line gain was higher in central cone group than paracentral cone group and oval group than globus group (p = .014, p = .045). The mean VAS score was 8.14 ± 1.88 (range: 6–10). Conclusions. Toris K can improve visual acuity of patients with keratoconus. Toris K is successful even in the moderate and advanced form of the disease. PMID:27144012

  3. High-precision drop shape analysis (HPDSA) of quasistatic contact angles on silanized silicon wafers with different surface topographies during inclining-plate measurements: Influence of the surface roughness on the contact line dynamics

    NASA Astrophysics Data System (ADS)

    Heib, F.; Hempelmann, R.; Munief, W. M.; Ingebrandt, S.; Fug, F.; Possart, W.; Groß, K.; Schmitt, M.

    2015-07-01

    Contact angles and wetting of solid surfaces are strongly influenced by the physical and chemical properties of the surfaces. These influence quantities are difficult to distinguish from each other if contact angle measurements are performed by measuring only the advancing θa and the receding θr contact angle. In this regard, time-dependent water contact angles are measured on two hydrophobic modified silicon wafers with different physical surface topographies. The first surface is nearly atomically flat while the second surface is patterned (alternating flat and nanoscale rough patterns) which is synthesized by a photolithography and etching procedure. The different surface topographies are characterized with atomic force microscopy (AFM), Fourier transform infrared reflection absorption spectroscopy (FTIRRAS) and Fourier transform infrared attenuated total reflection spectroscopy (FTIR-ATR). The resulting set of contact angle data obtained by the high-precision drop shape analysis approach is further analyzed by a Gompertzian fitting procedure and a statistical counting procedure in dependence on the triple line velocity. The Gompertzian fit is used to analyze overall properties of the surface and dependencies between the motion on the front and the back edge of the droplets. The statistical counting procedure results in the calculation of expectation values E(p) and standard deviations σ(p) for the inclination angle φ, contact angle θ, triple line velocity vel and the covered distance of the triple line dis relative to the first boundary points XB,10. Therefore, sessile drops during the inclination of the sample surface are video recorded and different specific contact angle events in dependence on the acceleration/deceleration of the triple line motion are analyzed. This procedure results in characteristically density distributions in dependence on the surface properties. The used procedures lead to the possibility to investigate influences on contact

  4. A modified captive bubble method for determining advancing and receding contact angles

    NASA Astrophysics Data System (ADS)

    Xue, Jian; Shi, Pan; Zhu, Lin; Ding, Jianfu; Chen, Qingmin; Wang, Qingjun

    2014-03-01

    In this work, a modification to the captive bubble method was proposed to test the advancing and receding contact angle. This modification is done by adding a pressure chamber with a pressure control system to the original experimental system equipped with an optical angle mater equipped with a high speed CCD camera, a temperature control system and a computer. A series of samples with highly hydrophilic, hydrophilic, hydrophobic and superhydrophobic surfaces were prepared. The advancing and receding contact angles of these samples with highly hydrophilic, hydrophilic, and hydrophobic surfaces through the new methods was comparable to the result tested by the traditional sessile drop method. It is proved that this method overcomes the limitation of the traditional captive bubble method and the modified captive bubble method allows a smaller error from the test. However, due to the nature of the captive bubble technique, this method is also only suitable for testing the surface with advancing or receding contact angle below 130°.

  5. Contact line and bulk velocities in evaporating micron-scale droplets

    NASA Astrophysics Data System (ADS)

    Fan, Yi; Breuer, Kenneth S.

    2013-11-01

    The famous ``coffee stain'' phenomena is well known during the evaporation of a liquid droplet seeded with colloidal particles. However, the different phases of evaporation on a hydrophobic surface have not yet been fully explored and explained. In this experiment, evaporating micro-drops (diameter ~100 μm) are seeded with 300 nm red fluorescent particles and observed from below using epifluorescent microscopy. We observed four phases: (i) steady evaporation with the contact line retreating at a constant speed of ~2 μm/s (ii) stagnation of the contact line for several seconds; (iii) a sharp transition leading to fast evaporation with a rapidly retreating contact line, and (iv) final dry-out of the film leaving the particles immobilized on the substrate. These four phases of motion, as well as the pattern of the deposited nano-particles are strong functions of both the colloidal concentration and the static contact angle. Statistical Particle Tracking Velocimetry is used to quantify the velocity fields inside the micro-drop during the evaporation history.

  6. Thin Films in Partial Wetting: Internal Selection of Contact-Line Dynamics.

    PubMed

    Alizadeh Pahlavan, Amir; Cueto-Felgueroso, Luis; McKinley, Gareth H; Juanes, Ruben

    2015-07-17

    When a liquid touches a solid surface, it spreads to minimize the system's energy. The classic thin-film model describes the spreading as an interplay between gravity, capillarity, and viscous forces, but it cannot see an end to this process as it does not account for the nonhydrodynamic liquid-solid interactions. While these interactions are important only close to the contact line, where the liquid, solid, and gas meet, they have macroscopic implications: in the partial-wetting regime, a liquid puddle ultimately stops spreading. We show that by incorporating these intermolecular interactions, the free energy of the system at equilibrium can be cast in a Cahn-Hilliard framework with a height-dependent interfacial tension. Using this free energy, we derive a mesoscopic thin-film model that describes the statics and dynamics of liquid spreading in the partial-wetting regime. The height dependence of the interfacial tension introduces a localized apparent slip in the contact-line region and leads to compactly supported spreading states. In our model, the contact-line dynamics emerge naturally as part of the solution and are therefore nonlocally coupled to the bulk flow. Surprisingly, we find that even in the gravity-dominated regime, the dynamic contact angle follows the Cox-Voinov law.

  7. Thin Films in Partial Wetting: Internal Selection of Contact-Line Dynamics

    NASA Astrophysics Data System (ADS)

    Alizadeh Pahlavan, Amir; Cueto-Felgueroso, Luis; McKinley, Gareth H.; Juanes, Ruben

    2015-07-01

    When a liquid touches a solid surface, it spreads to minimize the system's energy. The classic thin-film model describes the spreading as an interplay between gravity, capillarity, and viscous forces, but it cannot see an end to this process as it does not account for the nonhydrodynamic liquid-solid interactions. While these interactions are important only close to the contact line, where the liquid, solid, and gas meet, they have macroscopic implications: in the partial-wetting regime, a liquid puddle ultimately stops spreading. We show that by incorporating these intermolecular interactions, the free energy of the system at equilibrium can be cast in a Cahn-Hilliard framework with a height-dependent interfacial tension. Using this free energy, we derive a mesoscopic thin-film model that describes the statics and dynamics of liquid spreading in the partial-wetting regime. The height dependence of the interfacial tension introduces a localized apparent slip in the contact-line region and leads to compactly supported spreading states. In our model, the contact-line dynamics emerge naturally as part of the solution and are therefore nonlocally coupled to the bulk flow. Surprisingly, we find that even in the gravity-dominated regime, the dynamic contact angle follows the Cox-Voinov law.

  8. Characterization of optical components using contact and non-contact interferometry techniques: advanced metrology for optical components

    NASA Astrophysics Data System (ADS)

    Yu, Yang; Conroy, Mike; Smith, Richard

    2012-10-01

    Advanced metrology plays an important role in the research, production and quality control of optical components. With surface finish, form error and other parameter specifications becoming more stringent, precision measurements are increasingly demanded by optics manufacturers and users. The modern metrologist now has both contact and noncontact measurement solutions available and a combination of these techniques now provides a more detailed understanding of optical components. Phase Grating Interferometry (PGI) with sub-nanometre vertical resolution and sub-micron lateral resolution can provide detailed characterization of a wide range of components including shallow and steep-sided optics. PGI is ideal for precision form measurement of a comprehensive range of lenses, moulds and other spherical or aspheric products. Because of the complex nature of these components, especially precision aspheric and asphero-diffractive optics, control of the form is vital to ensure they perform correctly. Recent hardware and software developments now make it possible to gain a better understanding and control of the form and function of this optics. Another change is the use of high speed 3D non-contact measurement of optics which is becoming more popular. Often scanning interferometric techniques such as coherence correlation interferometry (CCI) can be used to study components not suited to 2D contact analysis, including fragile surfaces and structured surfaces. Scanning interferometry can also be used to measure film thickness and uniformity of any coating present. In this paper the use of both PGI and CCI to measure optical lenses and coatings is discussed.

  9. Thermocapillary effects on steadily evaporating contact line: A perturbative local analysis

    NASA Astrophysics Data System (ADS)

    Benselama, Adel M.; Harmand, Souad; Sefiane, Khellil

    2012-07-01

    The evaporation process taking place close to the three-phase contact line is considered and studied theoretically using a linear stability analysis approach. A domain perturbation method, taking into consideration thermocapillary effects and surface forces, is used to develop the higher-order solution in terms of series expansion about lubrication condition. A closed-form solution is found for the film thickness, the pressure jump across the liquid-vapor interface and the evaporative flux in the vicinity of the contact line. The key novelty in this work is considering thermocapillary instability for very thin films (˜10 nm) accounting for surface forces. For (quasi-) flat-very-thin films, the analysis shows no instability, which is consistent with general knowledge in this field. However, for films extending from a meniscus, as encountered in wetting configurations, it is found that the competition between London-van der Waals, capillary, and thermocapillary forces leads to contact line instability and behavior revealed for the first time. According to the sign of the Marangoni number, the instability can enhance (if positive) or reduce (if negative) the evaporation rate by widening out or narrowing, respectively, the contact region and, in both cases, significantly modifies the vortical structure of the flow. If the Marangoni number is positive, the film interface close to the contact line can exhibit corrugations. The occurrence of these latter is discriminated, in addition to the Marangoni number, by the value of three operating parameters, namely the film aspect ratio, the ratio of the film diffusive thermal resistance to evaporative heat transfer resistance, and the ratio of capillary pressure to disjoining pressure. By modifying the physical and operating parameters, it is also shown that the system can be optimized in order to suppress these corrugations.

  10. Microregion model of a contact line including evaporation, kinetics and slip

    NASA Astrophysics Data System (ADS)

    Anderson, Daniel; Janecek, Vladislav

    2016-11-01

    We consider the evaporation of a liquid on a uniformly heated solid substrate. In the framework of lubrication theory we consider hydrodynamics, heat conduction, phase change, evaporation kinetics, and slip. Our model focuses only on the contact line 'inner' region which allows us to quantify the impact of evaporation on the apparent contact angle and microregion heat transfer. The linearized problem with respect to the substrate overheating is solved analytically. The analytical solutions are compared with full numerical solutions and to predictions of Hocking.

  11. Fast Imaging of Freezing Drops: Investigating Contact Nucleation at the Triple Line

    NASA Astrophysics Data System (ADS)

    Gurganus, C.

    2011-12-01

    Heterogeneous nucleation of cloud droplets is important for understanding cloud microphysical processes, but the relevant roles of the primary nucleation pathways remains an open question. The contact and immersion modes are two of the primary pathways in the troposphere. An interpretation of difference between the contact and immersion modes is based on the energy barrier for nucleation at a three-phase and two-phase interface, respectively. Previous laboratory experiments have noted a preference for nucleation in the contact mode, with freezing temperatures 2-5K warmer than in the immersion mode. However, our recent study [1] shows no preference for nucleation in the contact mode. This surprising null result may indicate the importance of other, non-thermodynamic factors for contact nucleation. We employ high speed imaging of supercooled water drops, to determine nucleation site spatial statistics. Our geometry avoids the "point-like contact" associated with seed particles by providing a simple, symmetric contact line (triple line defined by the substrate-liquid-air interface) for a drop resting on a homogeneous silicon substrate. Furthermore, the imaging configuration localizes nucleation sites in the horizontal plane. Initial tests used low cooling rates to minimize temperature variation within the water drop. The freezing events display nearly perfect spatial uniformity in the immersed (liquid-substrate) region and, thereby, no preference for nucleation at the triple line [1]. Using a related technique, but relying on a rapid cooling rate, Suzuki et al. [2] note preferential nucleation at the triple line, contrasting with our observations and possibly indicating a thermodynamic preference for contact nucleation. Aside from differences in imaging techniques, our experiment was utilized a very slow cooling system, so as to ensure equal opportunity for freezing throughout the water volume. A simple calculation of the rate of thermal diffusion in a rapidly cooled

  12. Apparent Contact Angle and Triple-Line Tension of a Soap Bubble on a Substrate.

    PubMed

    Rodrigues, João Filipe; Saramago, Benilde; Fortes, Manuel Amaral

    2001-07-15

    The contact angle, θ, of a small bubble on a flat solid substrate was measured as a function of bubble radius, R. The observed deviation of the contact angle from 90 degrees can be accounted for in terms of a negative line tension, tau. The measured values of |tau|/gamma(f), where gamma(f) is the film tension, ranged between 0.15 and 0.6 mm and are proportional to the height, h, of the Plateau border, with |tau| congruent with1.7gamma(f)h. Copyright 2001 Academic Press.

  13. Axisymmetric oscillations of a cylindrical droplet with a moving contact line

    NASA Astrophysics Data System (ADS)

    Alabuzhev, A. A.

    2016-11-01

    Forced oscillations of a cylindrical droplet of an inviscid liquid surrounded by another liquid and bounded in the axial direction by rigid planes are investigated. The system is affected by vibrations whose force is directed parallel to the axis of symmetry of the droplet. The velocity of motion of the contact line is proportional to the deviation of the contact angle from the value at which the droplet is in equilibrium. Linear and nonlinear oscillations are considered. The conditions of the occurrence of resonance are determined.

  14. Fitting an MSD (mini scleral design) rigid contact lens in advanced keratoconus with INTACS.

    PubMed

    Dalton, Kristine; Sorbara, Luigina

    2011-12-01

    Keratoconus is a bilateral degenerative disease characterized by a non-inflammatory, progressive central corneal ectasia (typically asymmetric) and decreased vision. In its early stages it may be managed with spectacles and soft contact lenses but more commonly it is managed with rigid contact lenses. In advanced stages, when contact lenses can no longer be fit, have become intolerable, or corneal damage is severe, a penetrating keratoplasty is commonly performed. Alternative surgical techniques, such as the use of intra-stromal corneal ring segments (INTACS) have been developed to try and improve the fit of rigid contact lenses in keratoconic patients and avoid penetrating keratoplasties. This case report follows through the fitting of rigid contact lenses in an advanced keratoconic cornea after an INTACS procedure and discusses clinical findings, treatment options, and the use of mini-scleral and scleral lens designs as they relate to the challenges encountered in managing such a patient. Mini-scleral and scleral lenses are relatively easy to fit, and can be of benefit to many patients, including advanced keratoconic patients, post-INTAC patients and post-penetrating keratoplasty patients.

  15. Microscopic Receding Contact Line Dynamics on Pillar and Irregular Superhydrophobic Surfaces

    PubMed Central

    Yeong, Yong Han; Milionis, Athanasios; Loth, Eric; Bayer, Ilker S.

    2015-01-01

    Receding angles have been shown to have great significance when designing a superhydrophobic surface for applications involving self-cleaning. Although apparent receding angles under dynamic conditions have been well studied, the microscopic receding contact line dynamics are not well understood. Therefore, experiments were performed to measure these dynamics on textured square pillar and irregular superhydrophobic surfaces at micron length scales and at micro-second temporal scales. Results revealed a consistent “slide-snap” motion of the microscopic receding line as compared to the “stick-slip” dynamics reported in previous studies. Interface angles between 40–60° were measured for the pre-snap receding lines on all pillar surfaces. Similar “slide-snap” dynamics were also observed on an irregular nanocomposite surface. However, the sharper features of the surface asperities resulted in a higher pre-snap receding line interface angle (~90°). PMID:25670630

  16. Contact angle hysteresis explained.

    PubMed

    Gao, Lichao; McCarthy, Thomas J

    2006-07-04

    A view of contact angle hysteresis from the perspectives of the three-phase contact line and of the kinetics of contact line motion is given. Arguments are made that advancing and receding are discrete events that have different activation energies. That hysteresis can be quantified as an activation energy by the changes in interfacial area is argued. That this is an appropriate way of viewing hysteresis is demonstrated with examples.

  17. Contact line dynamics of electroosmotic flows of incompressible binary fluid system with density and viscosity contrasts

    NASA Astrophysics Data System (ADS)

    Mondal, Pranab Kumar; DasGupta, Debabrata; Bandopadhyay, Aditya; Ghosh, Uddipta; Chakraborty, Suman

    2015-03-01

    We consider electrically driven dynamics of an incompressible binary fluid, with contrasting densities and viscosities of the two phases, flowing through narrow fluidic channel with walls with predefined surface wettabilities. Through phase field formalism, we describe the interfacial kinetics in the presence of electro-hydrodynamic coupling and address the contact line dynamics of the two-fluid system. We unveil the interplay of the substrate wettability and the contrast in the fluid properties culminating in the forms of two distinct regimes—interface breakup regime and a stable interface regime. Through a parametric study, we demarcate the effect of the density and viscosity contrasts along with the electrokinetic parameters such as the surface charge and ionic concentration on the underlying contact-line-dynamics over interfacial scales.

  18. Microcontact patterning of conductive silver lines by contact inking and its layer-transfer mechanisms

    NASA Astrophysics Data System (ADS)

    Kusaka, Yasuyuki; Nomura, Ken-ichi; Fukuda, Nobuko; Ushijima, Hirobumi

    2015-05-01

    We developed a contact inking technique for microcontact printing aiming at the fabrication of conductive silver-nanoparticle (Ag NP) lines with rectangular cross section and constant layer thickness, irrespective of pattern size and shape. In the proposed process, Ag NP ink was first coated on a blanket and then inking was carried out by a contact with a microcontact stamp. The ink transferred onto the top of the stamp was finally settled on a workpiece by pressing to complete the printing process. To achieve robust inking to the stamp, the peel strengths between the Ag NP layer and the blankets and between the Ag NP layer and the stamp were investigated using poly (dimethylsiloxane) (PDMS) materials with different surface energies. Interestingly, it was revealed that the transferability of Ag NP from the blanket toward the stamp was not solely determined by the surface energy difference but also by the extent of solvent uptake by the PDMS blanket during inking. The solvent-containing PDMS significantly lowered its adhesion strength against adjacent ink layers and, as a consequence, the ink transfer was successfully achieved even if the ink passed from a higher to a lower energy surface. Furthermore, by the solvent-vapour annealing of contact-inked semi-dried patterns, arbitrarily iterated transfers between PDMS surfaces became possible. With the contact-inking process developed here, we demonstrate a finely defined printed structure of Ag NP conductive lines with widths of up to 1 μm.

  19. Droplets and the three-phase contact line at the nano-scale. Statics and dynamics

    NASA Astrophysics Data System (ADS)

    Yatsyshin, Petr; Sibley, David; Savva, Nikos; Kalliadasis, Serafim

    2014-11-01

    Understanding the behaviour of the solid-liquid-vapour contact line at the scale of several tens of molecular diameters is important in wetting hydrodynamics with applications in micro- and nano-fluidics, including the design of lab-on-a-chip devices and surfaces with specific wetting properties. Due to the fluid inhomogeneity at the nano-scale, the application of continuum-mechanical approaches is limited, and a natural way to remedy this is to seek descriptions accounting for the non-local molecular-level interactions. Density Functional Theory (DFT) for fluids offers a statistical-mechanical framework based on expressing the free energy of the fluid-solid pair as a functional of the spatially varying fluid density. DFT allows us to investigate small drops deposited on planar substrates whilst keeping track of the microscopic structural details of the fluid. Starting from a model of intermolecular forces, we systematically obtain interfaces, surface tensions, and the microscopic contact angle. Using a dynamic extension of equilibrium DFT, we investigate the diffusion-driven evolution of the three-phase contact line to gain insight into the dynamic behaviour of the microscopic contact angle, which is still under debate.

  20. On the Boundary Conditions at an Oscillating Contact Line: A Physical/Numerical Experimental Program

    NASA Technical Reports Server (NTRS)

    Perlin, Marc; Schultz, William W.

    1996-01-01

    We will pursue an improved physical understanding and mathematical model for the boundary condition at an oscillating contact line at high Reynolds number. We expect that the body force is locally unimportant for earth-based systems, and that the local behavior may dominate the mechanics of partially-filled reservoirs in the microgravity environment. One important space-based application for this contact-line study is for Faraday-waves. Oscillations in the direction of gravity (or acceleration) can dominate the fluid motion during take-off and reentry with large steady-state accelerations and in orbit, where fluctuations on the order of 10(exp -4)g occur about a zero mean. Our experience with Faraday waves has shown them to be 'cleaner' than those produced by vertical or horizontal oscillation of walls. They are easier to model analytically or computationally, and they do not have strong vortex formation at the bottom of the plate. Hence many, if not most, of the experiments will be performed in this manner. The importance of contact lines in the microgravity environment is well established. We will compare high resolution measurements of the velocity field (lO micro-m resolution) using particle-tracking and particle-image velocimetry as the fluid/fluid interface is approached from the lower fluid. The spatial gradients in the deviation provide additional means to determine an improved boundary condition and a measure of the slip region. Dissipation, the size of the eddy near the contact line, and hysteresis will be measured and compare to linear and nonlinear models of viscous and irrotational but dissipative models.

  1. Characterization of micro-contact resistance between a gold nanocrystalline line and a tungsten electrode probe in interconnect fatigue testing.

    PubMed

    Ling, Xue; Wang, Yusheng; Li, Xide

    2014-10-01

    An electromechanically-coupled micro-contact resistance measurement system is built to mimic the contact process during fatigue testing of nanoscale-thickness interconnects using multiple probe methods. The design combines an optical microscope, high-resolution electronic balance, and micromanipulator-controlled electric probe, and is coupled with electrical measurements to investigate microscale contact physics. Experimental measurements are performed to characterize the contact resistance response of the gold nanocrystalline pad of a 35-nm-thick interconnect under mechanical force applied by a tungsten electrode probe. Location of a stable region for the contact resistance and the critical contact force provides better understanding of micro-contact behavior relative to the effects of the contact force and the nature of the contact surface. Increasing contact temperature leads to reduced contact resistance, softens the pad material, and modifies the contact surface. The stability of both contact resistance and interconnect resistance is studied under increasing contact force. Major fluctuations emerge when the contact force is less than the critical contact force, which shows that temporal contact resistance will affect interconnect resistance measurement accuracy, even when using the four-wire method. This performance is demonstrated experimentally by heating the Au line locally with a laser beam. Finally, the contact resistances are calculated using the LET (Li-Etsion-Talke) model together with combined Holm and Sharvin theory under various contact forces. Good agreement between the results is obtained. This research provides a way to measure change in interconnect line resistance directly under a stable contact resistance regime with a two-wire method that will greatly reduce the experimental costs.

  2. Characterization of micro-contact resistance between a gold nanocrystalline line and a tungsten electrode probe in interconnect fatigue testing

    NASA Astrophysics Data System (ADS)

    Ling, Xue; Wang, Yusheng; Li, Xide

    2014-10-01

    An electromechanically-coupled micro-contact resistance measurement system is built to mimic the contact process during fatigue testing of nanoscale-thickness interconnects using multiple probe methods. The design combines an optical microscope, high-resolution electronic balance, and micromanipulator-controlled electric probe, and is coupled with electrical measurements to investigate microscale contact physics. Experimental measurements are performed to characterize the contact resistance response of the gold nanocrystalline pad of a 35-nm-thick interconnect under mechanical force applied by a tungsten electrode probe. Location of a stable region for the contact resistance and the critical contact force provides better understanding of micro-contact behavior relative to the effects of the contact force and the nature of the contact surface. Increasing contact temperature leads to reduced contact resistance, softens the pad material, and modifies the contact surface. The stability of both contact resistance and interconnect resistance is studied under increasing contact force. Major fluctuations emerge when the contact force is less than the critical contact force, which shows that temporal contact resistance will affect interconnect resistance measurement accuracy, even when using the four-wire method. This performance is demonstrated experimentally by heating the Au line locally with a laser beam. Finally, the contact resistances are calculated using the LET (Li-Etsion-Talke) model together with combined Holm and Sharvin theory under various contact forces. Good agreement between the results is obtained. This research provides a way to measure change in interconnect line resistance directly under a stable contact resistance regime with a two-wire method that will greatly reduce the experimental costs.

  3. Characterization of micro-contact resistance between a gold nanocrystalline line and a tungsten electrode probe in interconnect fatigue testing

    SciTech Connect

    Ling, Xue; Wang, Yusheng; Li, Xide

    2014-10-15

    An electromechanically-coupled micro-contact resistance measurement system is built to mimic the contact process during fatigue testing of nanoscale-thickness interconnects using multiple probe methods. The design combines an optical microscope, high-resolution electronic balance, and micromanipulator-controlled electric probe, and is coupled with electrical measurements to investigate microscale contact physics. Experimental measurements are performed to characterize the contact resistance response of the gold nanocrystalline pad of a 35-nm-thick interconnect under mechanical force applied by a tungsten electrode probe. Location of a stable region for the contact resistance and the critical contact force provides better understanding of micro-contact behavior relative to the effects of the contact force and the nature of the contact surface. Increasing contact temperature leads to reduced contact resistance, softens the pad material, and modifies the contact surface. The stability of both contact resistance and interconnect resistance is studied under increasing contact force. Major fluctuations emerge when the contact force is less than the critical contact force, which shows that temporal contact resistance will affect interconnect resistance measurement accuracy, even when using the four-wire method. This performance is demonstrated experimentally by heating the Au line locally with a laser beam. Finally, the contact resistances are calculated using the LET (Li–Etsion–Talke) model together with combined Holm and Sharvin theory under various contact forces. Good agreement between the results is obtained. This research provides a way to measure change in interconnect line resistance directly under a stable contact resistance regime with a two-wire method that will greatly reduce the experimental costs.

  4. Advances in fuel management and on-line core monitoring

    SciTech Connect

    Stout, R.B.; Hansen, L.E.; Patten, T.W.

    1988-01-01

    Advanced Nuclear Fuels Corporation (ANF) has developed and implemented advanced core power distribution monitoring methods for BWRs and PWRs based on the three dimensional nodal simulator codes used for incore fuel management design and analysis. The use of these methods has resulted in a more accurate assessment of the core power distribution and corresponding increased operating margins. These increased margins allow for more economical fuel cycle designs. Since the initial application in 1982, ANF has made enhancements to the incore monitoring system. These enhancements have permitted more rapid analysis of local power changes, power distribution projections during ascent to full power and on-line statistical analysis of the incore detector signal. The on-line analysis implemented in BWRs has also been developed for application PWRs. In the future, reactors are expected to operate with longer fuel cycles, more aggressive low radial leakage loadings, load follow and use higher burnup fuel. These advances will require more burnable neutron absorbers and more sophisticated fuel designs. To accommodate these advances, the fuel management methodologies and measurement system will require improvements. The state-of-the-art methods provided by ANF provide incore monitoring systems compatible with these expected needs.

  5. Flow boundary conditions for fluid mixtures at solid walls and moving contact lines

    NASA Astrophysics Data System (ADS)

    Robbins, Mark

    2005-11-01

    Molecular simulations of slip at solid surfaces have focused on single component systems, but polymers are frequently blended to optimize performance. This talk will examine counterintuitive behavior that can arise when binary fluid mixtures flow past stationary solid walls in simple shear and at moving contact lines. In general the velocities of the two species do not go to zero at the walls. In addition to the slip found for single fluids, there may be velocity discontinuities due to diffusive fluxes and to interfacial forces when there is a concentration gradient.^1 Cases where the fluid velocity is largest near the wall and where the apparent slip length diverges will be shown, and a general boundary condition for multi-phase flow presented. The no-slip boundary condition leads to singular dissipation when the contact line between a fluid interface and solid moves, but it was suggested that a diffusive flux could remove this singularity.^2 The flow and stress near moving contact lines are analyzed for a range of interfacial widths, velocities and interactions. A significant diffusive flux is only observed in the layer closest to the solid and is not sufficient to remove the singularity. Instead, the finite molecular size and non-Newtonian effects cutoff the singularity.1. C. Denniston and M. O. Robbins, Phys. Rev. Lett. 87, 178302 (2001).2. H.-Y. Chen and D. Jasnow and J. Vinals, Phys. Rev. Lett. 85, 1686 (2000).

  6. On-line application of the PANTHER advanced nodal code

    SciTech Connect

    Hutt, P.K.; Knight, M.P. )

    1992-01-01

    Over the last few years, Nuclear Electric has developed an integrated core performance code package for both light water reactors (LWRs) and advanced gas-cooled reactors (AGRs) that can perform a comprehensive range of calculations for fuel cycle design, safety analysis, and on-line operational support for such plants. The package consists of the following codes: WIMS for lattice physics, PANTHER whole reactor nodal flux and AGR thermal hydraulics, VIPRE for LWR thermal hydraulics, and ENIGMA for fuel performance. These codes are integrated within a UNIX-based interactive system called the Reactor Physics Workbench (RPW), which provides an interactive graphic user interface and quality assurance records/data management. The RPW can also control calculational sequences and data flows. The package has been designed to run both off-line and on-line accessing plant data through the RPW.

  7. Implications of the contact radius to line step (CRLS) ratio in AFM for nanotribology measurements.

    PubMed

    Helt, James M; Batteas, James D

    2006-07-04

    Investigating the mechanisms of defect generation and growth at surfaces on the nanometer scale typically requires high-resolution tools such as the atomic force microscope (AFM). To accurately assess the kinetics and activation parameters of defect production over a wide range of loads (F(z)), the AFM data should be properly conditioned. Generally, AFM wear trials are performed over an area defined by the length of the slow (L(sscan)) and fast scan axes. The ratio of L(sscan) to image resolution (res, lines per image) becomes an important experimental parameter in AFM wear trials because it defines the magnitude of the line step (LS = L(sscan)/res), the distance the AFM tip steps along the slow scan axis. Comparing the contact radius (a) to the line step (LS) indicates that the overlap of successive scans will result unless the contact radius-line step ratio (CRLS) is < or =(1)/(2). If this relationship is not considered, then the scan history (e.g., contact frequency) associated with a single scan is not equivalent at different loads owing to the scaling of contact radius with load (a proportional variant F(z)(1/3)). Here, we present a model in conjunction with empirical wear tests on muscovite mica to evaluate the effects of scan overlap on surface wear. Using the Hertz contact mechanics definition of a, the CRLS model shows that scan overlap pervades AFM wear trials even under low loads. Such findings indicate that simply counting the number of scans (N(scans)) in an experiment underestimates the full history conveyed to the surface by the tip and translates into an error in the actual extent to which a region on the surface is contacted. Utilizing the CRLS method described here provides an approach to account for image scan history accurately and to predict the extent of surface wear. This general model also has implications for any AFM measurement where one wishes to correlate scan-dependent history to image properties as well as feature resolution in scanned

  8. Effect of tibial tuberosity advancement on femorotibial contact mechanics and stifle kinematics.

    PubMed

    Kim, Stanley E; Pozzi, Antonio; Banks, Scott A; Conrad, Bryan P; Lewis, Daniel D

    2009-01-01

    Objective- To evaluate the effects of tibial tuberosity advancement (TTA) on femorotibial contact mechanics and 3-dimensional kinematics in cranial cruciate ligament (CrCL)-deficient stifles of dogs. Study Design- In vitro biomechanical study. Animals- Unpaired pelvic limbs from 8 dogs, weighing 28-35 kg. Methods- Digital pressure sensors placed subjacent to the menisci were used to measure femorotibial contact force, contact area, peak and mean contact pressure, and peak pressure location with the limb under an axial load of 30% body weight and a stifle angle of 135 degrees . Three-dimensional static poses of the stifle were obtained using a Microscribe digitizing arm. Each specimen was tested under normal, CrCL-deficient, and TTA-treated conditions. Repeated measures analysis of variance with a Tukey post hoc test (P<.05) was used for statistical comparison. Results- Significant disturbances to all measured contact mechanic parameters were evident after CrCL transection, which corresponded to marked cranial tibial subluxation and internal tibial rotation in the CrCL-deficient stifle. No significant differences in any contact mechanic and kinematic parameters were detected between normal and TTA-treated stifles. Conclusion- TTA eliminates craniocaudal stifle instability during simulated weight-bearing and concurrently restores femorotibial contact mechanics to normal. Clinical Relevance- TTA may mitigate the progression of stifle osteoarthritis in dogs afflicted with CrCL insufficiency by eliminating cranial tibial thrust while preserving the normal orientation of the proximal tibial articulating surface.

  9. Contact Line Instability of Gravity-Driven Flow of Power-Law Fluids.

    PubMed

    Hu, Bin; Kieweg, Sarah L

    2015-11-01

    The moving contact line of a thin fluid film can often corrugate into fingers, which is also known as a fingering instability. Although the fingering instability of Newtonian fluids has been studied extensively, there are few studies published on contact line fingering instability of non-Newtonian fluids. In particular, it is still unknown how shear-thinning rheological properties can affect the formation, growth, and shape of a contact line instability. Our previous study (Hu and Kieweg, 2012) showed a decreased capillary ridge formation for more shear-thinning fluids in a 2D model (i.e. 1D thin film spreading within the scope of lubrication theory). Those results motivated this study's hypothesis: more shear-thinning fluids should have suppressed finger growth and longer finger wavelength, and this should be evident in linear stability analysis (LSA) and 3D (i.e. 2D spreading) numerical simulations. In this study, we developed a LSA model for the gravity-driven flow of shear-thinning films, and carried out a parametric study to investigate the impact of shear-thinning on the growth rate of the emerging fingering pattern. A fully 3D model was also developed to compare and verify the LSA results using single perturbations, and to explore the result of multiple-mode, randomly imposed perturbations. Both the LSA and 3D numerical results confirmed that the contact line fingers grow faster for Newtonian fluids than the shear-thinning fluids on both vertical and inclined planes. In addition, both the LSA and 3D model indicated that the Newtonian fluids form fingers with shorter wavelengths than the shear-thinning fluids when the plane is inclined; no difference in the most unstable (i.e. emerging) wavelength was observed at vertical. This study also showed that the distance between emerging fingers was smaller on a vertical plane than on a less-inclined plane for shear-thinning fluids, as previously shown for Newtonian fluids. For the first time for shear

  10. 76 FR 62678 - Table Saw Blade Contact Injuries; Advance Notice of Proposed Rulemaking; Request for Comments and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-11

    ... COMMISSION 16 CFR Chapter II Table Saw Blade Contact Injuries; Advance Notice of Proposed Rulemaking; Request... blade contact, the regulatory alternatives discussed in this notice, other possible means to address... any personal identifiers, contact information, or other personal information provided, to...

  11. A scale-dependent model for direct computation of dynamic contact lines

    NASA Astrophysics Data System (ADS)

    Zaleski, S.; Afkhami, S.; Guion, A.; Buongiorno, J.

    2016-11-01

    When using numerical schemes for the simulation of moving contact lines with the classical "no-slip" boundary condition, the numerical solutions become dependent on grid spacing. Numerical approaches that account for the slip of the contact line avoid this difficulty; a numerically feasible slip length however can often be much larger than the physically "true" one. Afkhami et al. addressed this issue, where they proposed a numerical model for the implementation of contact angle based on the mesh size that resulted in mesh independent solutions. Here we refine and apply their numerical observation by studying the problem of coating a plate withdrawn from a viscous liquid reservoir. We consider a partially wetting liquid and show that depending on the capillary number, either a stationary meniscus is formed or a liquid film is deposited on the substrate, known as the transition to a Landau-Levich-Derjaguin film. We derive an effective numerical boundary condition model for the computation of the transition capillary number. The model can be thought of as a large scale solution in an asymptotic matching procedure.

  12. Physical ageing of the contact line on colloidal particles at liquid interfaces.

    PubMed

    Kaz, David M; McGorty, Ryan; Mani, Madhav; Brenner, Michael P; Manoharan, Vinothan N

    2011-12-04

    Young's law predicts that a colloidal sphere in equilibrium with a liquid interface will straddle the two fluids, its height above the interface defined by an equilibrium contact angle. This has been used to explain why colloids often bind to liquid interfaces, and has been exploited in emulsification, water purification, mineral recovery, encapsulation and the making of nanostructured materials. However, little is known about the dynamics of binding. Here we show that the adsorption of polystyrene microspheres to a water/oil interface is characterized by a sudden breach and an unexpectedly slow relaxation. The relaxation appears logarithmic in time, indicating that complete equilibration may take months. Surprisingly, viscous dissipation appears to play little role. Instead, the observed dynamics, which bear strong resemblance to ageing in glassy systems, agree well with a model describing activated hopping of the contact line over nanoscale surface heterogeneities. These results may provide clues to longstanding questions on colloidal interactions at an interface.

  13. Free surface profile of evaporative liquids at the vicinity of the contact line

    NASA Astrophysics Data System (ADS)

    Houssainy, Sammy; Kavehpour, Pirouz

    2014-11-01

    Interfacial phenomenon, specifically those associated with evaporation from thin liquid films near the contact line of a liquid drop, play a major role in many current engineering applications which require high local heat fluxes, as evident in heat pipes, grooved evaporators, fuel cells and suction nucleate boiling devices. This study will prove useful in the improvement of such applications. Fluoresces microscopy was used as our main technique of investigating the free surface profiles of evaporative liquids, as it delivers sufficient range and resolution to address the challenge of capturing the microscopic and macroscopic aspects of this phenomenon. Subsequent to our experimental findings, the results are compared with non-volatile liquids for both contact angle and free surface structures.

  14. Boundary conditions in the vicinity of a dynamic contact line: experimental investigation of viscous drops sliding down an inclined plane.

    PubMed

    Rio, E; Daerr, A; Andreotti, B; Limat, L

    2005-01-21

    To probe the microscopic balance of forces close to a moving contact line, the boundary conditions around viscous drops sliding down an inclined plane are investigated. At first, the variation of the contact angle as a function of the scale of analysis is discussed. The dynamic contact angle is measured at a scale of 6 mum all around sliding drops for different volumes and speeds. We show that it depends only on the capillary number based on the local liquid velocity, measured by particle tracking. This velocity turns out to be normal to the contact line everywhere. It indirectly proves that, in comparison with the divergence involved in the normal direction, the viscous stress is not balanced by intermolecular forces in the direction tangential to the contact line, so that any motion in this last direction gets damped.

  15. Non-contact single shot elastography using line field low coherence holography

    PubMed Central

    Liu, Chih-Hao; Schill, Alexander; Wu, Chen; Singh, Manmohan; Larin, Kirill V.

    2016-01-01

    Optical elastic wave imaging is a powerful technique that can quantify local biomechanical properties of tissues. However, typically long acquisition times make this technique unfeasible for clinical use. Here, we demonstrate non-contact single shot elastographic holography using a line-field interferometer integrated with an air-pulse delivery system. The propagation of the air-pulse induced elastic wave was imaged in real time, and required a single excitation for a line-scan measurement. Results on tissue-mimicking phantoms and chicken breast muscle demonstrated the feasibility of this technique for accurate assessment of tissue biomechanical properties with an acquisition time of a few milliseconds using parallel acquisition. PMID:27570694

  16. Structural transitions in a ring stain created at the contact line of evaporating nanosuspension sessile drops.

    PubMed

    Askounis, Alexandros; Sefiane, Khellil; Koutsos, Vasileios; Shanahan, Martin E R

    2013-01-01

    Monodisperse nanosuspension droplets, placed on a flat surface, evaporated following the stick-slip motion of the three-phase contact line. Unexpectedly, a disordered region formed at the exterior edge of a closely packed nanocolloidal crystalline structure during the "stick" period. In order to assess the role of particle velocity on particle structuring, we did experiments in a reduced pressure environment which allowed the enhancement of particle velocity. These experiments revealed the promotion of hexagonal packing at the very edge of the crystallite with increasing velocity. Quantification of particle velocity and comparison with measured deposit shape for each case allowed us to provide a tentative description of the underlying mechanisms that govern particle deposition of nanoparticles at the triple line of an evaporating droplet. Behavior is governed by an interplay between the fluid, and hence particle, flow velocity (main ordering parameter) and wedge constraints, and consequently disjoining pressure (main disordering parameter). Furthermore, the formation of a second disordered particle region at the interior edge of the deposit (towards bulk fluid) was found and attributed to the rapid motion of the triple line during the "slip" regime. Additionally, the magnitude of the pinning forces acting on the triple line of the same drops was calculated. These findings provide further insight into the mechanisms of the phenomenon and could facilitate its exploitation in various nanotechnological applications.

  17. Structural transitions in a ring stain created at the contact line of evaporating nanosuspension sessile drops

    NASA Astrophysics Data System (ADS)

    Askounis, Alexandros; Sefiane, Khellil; Koutsos, Vasileios; Shanahan, Martin E. R.

    2013-01-01

    Monodisperse nanosuspension droplets, placed on a flat surface, evaporated following the stick-slip motion of the three-phase contact line. Unexpectedly, a disordered region formed at the exterior edge of a closely packed nanocolloidal crystalline structure during the “stick” period. In order to assess the role of particle velocity on particle structuring, we did experiments in a reduced pressure environment which allowed the enhancement of particle velocity. These experiments revealed the promotion of hexagonal packing at the very edge of the crystallite with increasing velocity. Quantification of particle velocity and comparison with measured deposit shape for each case allowed us to provide a tentative description of the underlying mechanisms that govern particle deposition of nanoparticles at the triple line of an evaporating droplet. Behavior is governed by an interplay between the fluid, and hence particle, flow velocity (main ordering parameter) and wedge constraints, and consequently disjoining pressure (main disordering parameter). Furthermore, the formation of a second disordered particle region at the interior edge of the deposit (towards bulk fluid) was found and attributed to the rapid motion of the triple line during the “slip” regime. Additionally, the magnitude of the pinning forces acting on the triple line of the same drops was calculated. These findings provide further insight into the mechanisms of the phenomenon and could facilitate its exploitation in various nanotechnological applications.

  18. Pore-scale modeling of moving contact line problems in immiscible two-phase flow

    NASA Astrophysics Data System (ADS)

    Kucala, Alec; Noble, David; Martinez, Mario

    2016-11-01

    Accurate modeling of moving contact line (MCL) problems is imperative in predicting capillary pressure vs. saturation curves, permeability, and preferential flow paths for a variety of applications, including geological carbon storage (GCS) and enhanced oil recovery (EOR). Here, we present a model for the moving contact line using pore-scale computational fluid dynamics (CFD) which solves the full, time-dependent Navier-Stokes equations using the Galerkin finite-element method. The MCL is modeled as a surface traction force proportional to the surface tension, dependent on the static properties of the immiscible fluid/solid system. We present a variety of verification test cases for simple two- and three-dimensional geometries to validate the current model, including threshold pressure predictions in flows through pore-throats for a variety of wetting angles. Simulations involving more complex geometries are also presented to be used in future simulations for GCS and EOR problems. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  19. Impact of Elasticity on Coating Flow near A Moving Contact Line

    NASA Astrophysics Data System (ADS)

    Wei, Yuli; Garoff, Stephen; Ramé, Enrique; Walker, Lynn

    2009-03-01

    The impact of fluid elasticity and shear thinning on the dynamic wetting of polymer solutions is important because many fluids, even those that are normally considered Newtonian, exhibit non-Newtonian behaviors in the high shear environment of the wedge-like geometry near a moving contact line. Even though this behavior is on the microscopic scale, it has significant impact on wetting on the millimeter scale. Shear thinning dramatically modifies the flow field near a moving contact line and results in a reduced curvature of the free surface. In this talk, we will focus on the effects due to fluid elasticity. Both experimental and theoretical results are presented. The fluids we use are the dilute solutions of high molecular weight polyisobutylene (PIB) which exhibit elasticity-dominated rheology with minimal shear thinning. Their wetting behaviors are compared to their oligomer ``solvent,'' which is considered Newtonian based on standard rheometry. We will also discuss a lubrication analysis of the wedge-like flow field using an Oldroyd-B constitutive relation to mimic the stress evolution of the elastic solution.

  20. Two-phase DNS of evaporating drops with 3D phenomena and contact-line dynamics

    NASA Astrophysics Data System (ADS)

    Valluri, Prashant; Sáenz, Pedro J.; Sefiane, Khellil; Matar, Omar K.

    2014-11-01

    A novel 3D two-phase model based on the diffuse-interface method is developed to investigate the fully-coupled two-phase dynamics of a sessile drop undergoing evaporation on a heated substrate. General transient advection-diffusion transport equations are implemented to address the conservation of energy and vapour in the gas phase, which also allows the more realistic modelling of interface mass and energy transport based on local conditions. The emphasis of this investigation is on addressing three-dimensional phenomena during evaporation of drops with non-circular contact area. Irregular drops lead to complex interface shapes with intricate contract-angle distributions along the triple line and with a three-dimensional flow which previous axisymmetric approaches cannot show. The versatility of this model also allows the simulation of the more complex case of drops evaporating with a moving contact line. Both constant-angle (CA) and constant-radius (CR) modes of pure evaporation are successfully simulated and validated against experiments. ThermaPOWER project (EU IRSES-PIRSES GA-2011-294905).

  1. Current densities and total contact currents associated with 400 kV power line tasks.

    PubMed

    Korpinen, Leena; Kuisti, Harri; Elovaara, Jarmo

    2013-12-01

    The aim of the study was to analyze all current values from measured periods while performing tasks on 400 kV power lines. Our aim was also to study the average current densities and average total contact currents caused by electric fields in 400 kV power line tasks. Two workers simulated the following tasks: (A) climbing up a portal tower, (B) climbing up a portal transposing tower, (C) working on the cross-arm of a portal tower, (D) climbing up a portal tube tower, (E) climbing up a Tannenbaum tower on the side of the energized circuit with the other circuit unenergized, (F) climbing up a Tannenbaum tower with both circuits energized, and (G) climbing up a Donau tower. The highest average current density in the neck was 2.5 mA/m(2) (calculated internal electric field 31.5-63.0 mV/m), and the highest average of the contact currents was 240.0 µA. All measured values at 400 kV towers were lower than the limit value of 10 mA/m(2) in the first version of Directive 2004/40/EC and the basic restrictions (0.1 and 0.8 V/m) of the International Commission on Non-ionizing Radiation Protection.

  2. Advanced RF Sources Based on Novel Nonlinear Transmission Lines

    DTIC Science & Technology

    2015-01-26

    Green’s function on a slow wave structure. We derive the scaling laws for the contact resistance of both bulk contact and thin film contact , with general...aspect ratios and vastly different resistivity in the different contact members. We discover a voltage scale, which depends only on material property...vacuum transistor”, a high-speed transistor envisioned for the future. High power mirowave sources, electrical contact , surface heating U U U 23 Y

  3. Study and Experiment on Non-Contact Voltage Sensor Suitable for Three-Phase Transmission Line.

    PubMed

    Zhou, Qiang; He, Wei; Xiao, Dongping; Li, Songnong; Zhou, Kongjun

    2015-12-30

    A voltage transformer, as voltage signal detection equipment, plays an important role in a power system. Presently, more and more electric power systems are adopting potential transformer and capacitance voltage transformers. Transformers are often large in volume and heavyweight, their insulation design is difficult, and an iron core or multi-grade capacitance voltage division structure is generally adopted. As a result, the detection accuracy of transformer is reduced, a huge phase difference exists between detection signal and voltage signal to be measured, and the detection signal cannot accurately and timely reflect the change of conductor voltage signal to be measured. By aiming at the current problems of electric transformation, based on electrostatic induction principle, this paper designed a non-contact voltage sensor and gained detection signal of the sensor through electrostatic coupling for the electric field generated by electric charges of the conductor to be measured. The insulation structure design of the sensor is simple and its volume is small; phase difference of sensor measurement is effectively reduced through optimization design of the electrode; and voltage division ratio and measurement accuracy are increased. The voltage sensor was tested on the experimental platform of simulating three-phase transmission line. According to the result, the designed non-contact voltage sensor can realize accurate and real-time measurement for the conductor voltage. It can be applied to online monitoring for the voltage of three-phase transmission line or three-phase distribution network line, which is in accordance with the development direction of the smart grid.

  4. Study and Experiment on Non-Contact Voltage Sensor Suitable for Three-Phase Transmission Line

    PubMed Central

    Zhou, Qiang; He, Wei; Xiao, Dongping; Li, Songnong; Zhou, Kongjun

    2015-01-01

    A voltage transformer, as voltage signal detection equipment, plays an important role in a power system. Presently, more and more electric power systems are adopting potential transformer and capacitance voltage transformers. Transformers are often large in volume and heavyweight, their insulation design is difficult, and an iron core or multi-grade capacitance voltage division structure is generally adopted. As a result, the detection accuracy of transformer is reduced, a huge phase difference exists between detection signal and voltage signal to be measured, and the detection signal cannot accurately and timely reflect the change of conductor voltage signal to be measured. By aiming at the current problems of electric transformation, based on electrostatic induction principle, this paper designed a non-contact voltage sensor and gained detection signal of the sensor through electrostatic coupling for the electric field generated by electric charges of the conductor to be measured. The insulation structure design of the sensor is simple and its volume is small; phase difference of sensor measurement is effectively reduced through optimization design of the electrode; and voltage division ratio and measurement accuracy are increased. The voltage sensor was tested on the experimental platform of simulating three-phase transmission line. According to the result, the designed non-contact voltage sensor can realize accurate and real-time measurement for the conductor voltage. It can be applied to online monitoring for the voltage of three-phase transmission line or three-phase distribution network line, which is in accordance with the development direction of the smart grid. PMID:26729119

  5. Influence of the contact line velocity on the finger formation of the liquid film expanding on an inclined plate

    NASA Astrophysics Data System (ADS)

    Yamashita, Masatoshi; Nishikawa, Masato; Ito, Takahiro; Tsuji, Yoshiyuki

    2015-11-01

    When a liquid film flows down on an inclined solid surface, the contact line can be destabilized to finger shape. This phenomenon leads to the non-uniform height of the liquid surface or even to generation of dry patch, and then has a great effect on cooling of energy device and quality of coating. In previous studies, the final finger shapes have been discussed by relating the with capillary (Ca) number and the wetting properties of the liquid for the solid substrate, i.e. the contact angle. However, in the experimental studies, little attention has been paid on the difference between the static contact angle and the dynamic one, the latter which is actually observed when the finger is developing. In this study, we performed three-dimensional measurement of surface geometry of the liquid film to clarify how the dynamic contact angles and the Ca number influence the finger shape by optical method. We observed two different finger shapes depending on the volumes of the working fluid., and verified that the finger shapes depend on the contact angle scaled by Ca number. We found that the local dynamic contact angle and the contact line velocity on the trough part of the wavy contact line can be highly related with the final finger shape.

  6. Impact of the collective diffusion of charged nanoparticles in the convective/capillary deposition directed by receding contact lines.

    PubMed

    Noguera-Marín, Diego; Moraila-Martínez, Carmen Lucía; Cabrerizo-Vílchez, Miguel; Rodríguez-Valverde, Miguel Angel

    2016-02-01

    The motion of electrically charged particles under crowding conditions and subjected to evaporation-driven capillary flow might be ruled by collective diffusion. The concentration gradient developed inside an evaporating drop of colloidal suspension may reduce by diffusion the number of particles transported toward the contact line by convection. Unlike self-diffusion coefficient, the cooperative diffusion coefficient of interacting particles becomes more pronounced in crowded environments. In this work, we examined experimentally the role of the collective diffusion of charge-stabilized nanoparticles in colloidal patterning. To decouple the sustained evaporation from the contact line motion, we conducted evaporating menisci experiments with driven receding contact lines at low capillary number. This allowed us to explore convective assembly at fixed and low bulk concentration, which enabled to develop high concentration gradients. At fixed velocity of receding contact line, we explored a variety of substrate-particle systems where the particle-particle electrostatic interaction was changed (via p H) as well as the substrate receding contact angle and the relative humidity. We found that the particle deposition directed by receding contact lines may be controlled by the interplay between evaporative convection and collective diffusion, particularly at low particle concentration.

  7. Stochastic relaxation of the contact line of a water drop on a solid substrate subjected to white noise vibration: roles of hysteresis.

    PubMed

    Mettu, Srinivas; Chaudhury, Manoj K

    2010-06-01

    Relaxation of the three phase contact line of a sessile drop of water on a low energy surface is studied by subjecting it to a white noise vibration. While a spring force acts on the contact line whenever the contact angle deviates from its equilibrium value, it is opposed by hysteresis. The drop, therefore, remains pinned at a metastable state. With an appropriate amount of vibration, the drop can reach a global equilibrium state irrespective of its initial state, be it advanced or retreated. While the end state is free of hysteresis, the current study sheds light on the dynamics of relaxation that is analyzed in conjunction with a modified Langevin equation. Instead of exhibiting a smooth relaxation as predicted by the Langevin equation with a smooth background potential, stepwise relaxation is observed in most cases. These stepwise relaxations can be explained if the background potential is made slightly corrugated that signifies the existence of metastable states of a drop on a surface. The fluctuation of the displacement of the contact line is highly non-Gaussian. It is shown that an exponential distribution of the displacement fluctuation arises due to the nonlinear hysteresis term in the Langevin equation. The observations of stick-slip motion, the large time of relaxation, and the anomalous displacement fluctuation suggest that hysteresis is present during the relaxation process of the drop even though the final state reached by the drop is free of hysteresis. Finally, we compare the displacement fluctuations of the contact line on two different surfaces: a silicone rubber and a fluorocarbon monolayer. Although the displacement fluctuation is exponential in both cases, the later surface exhibits a greater variance of the distribution than the former plausibly due to differences in hysteresis. This result indicates that the fluctuation of displacement may be used as a tool to study the surface property of a low energy substrate.

  8. Line-profile and continuum variations of the contact binary SV Centauri

    NASA Technical Reports Server (NTRS)

    Rahe, J.; Drechsel, H.; Wargau, W.

    1982-01-01

    A total of five high and ten low dispersion UV spectra of the interacting contact binary SV Centauri obtained between 1979 and 1982 are analyzed. The low resolution observations cover the whole phase range, while a few selected phases were observed in high dispersion. The UV data were complemented with optical photometric and spectroscopic observations, in order to determine the tructure and absolute dimensions of the system. The profiles of prominent UV resonance and metastable lines undergo drastic changes with phase angle and time. Their overall appearance indicates relatively strong mass loss from the system, exhibiting pronounced variations of the stellar wind. The far UV continuum distribution suggests the presence of a luminous hot radiation source with maximum emission in the soft X-ray range, which is most apparently seen during the first quadrature phase, while it is weakest close to primary minimum. The case exchange and mass loss process as well as the evolutionary stage of SV Centauri are discussed.

  9. De-pinning of contact line of droplets on rough surfaces

    NASA Astrophysics Data System (ADS)

    Madhurima, V.; Nilavarasi, K.

    2016-10-01

    The present study reports the formation of self-assembled droplet pattern on the PDMS polymer coated over grooved side of DVD under saturated vapours of alcohols. Comparison of the results with breath figures formed over unconstrained side of DVD is made. Four different environments namely methanol, ethanol, 2-propanol and n-butanol are used for the analysis. It is observed that the pattern formation occurs with methanol and ethanol vapours and not with 2-propanol and n-butanol. The difference is pattern formation with different alcohols is attributed to the variation in chain length and the presence of hydrophobic groups in alcohols, as given by Traube's rule. The distortion of patterns over constrained surface is attributed to the depinning of contact lines.

  10. Coffee Rings: Solute Deposits at the Contact Line of a Drying Sessile Drop

    NASA Astrophysics Data System (ADS)

    Deegan, Robert D.; Bakajin, Olgica; Nagel, Sidney R.; Witten, Thomas

    1996-03-01

    The preferential deposition of solute at the contact line of a drying solution is a common sight. Coffee rings, the concentration of coffee residue along the periphery of a dried coffee drop, are a prime example of this phenomenon. We experimentally investigated this effect in drying sessile drops. In particular, we examined the dependence of ring formation on the wetting properties, surface roughness and hydrophilicity of the substrate, on various combinations of solute and solvent, on solute concentration and size, on temperature gradients, and on gravity and electric fields. We found that a partial wetting substrate is the only essential ingredient for ring formation. In addition, we found the role of traditional transport mechanisms, such as diffusion, Raleigh-Bernard convection and Maragoni flow, to be negligible. We will present fluorescent video microscopy data using a colloidal solute to argue in favor of an evaporation driven model.

  11. Assessment of the U937 cell line for the detection of contact allergens

    SciTech Connect

    Python, Francois . E-mail: python.f@pg.com; Goebel, Carsten; Aeby, Pierre

    2007-04-15

    The human myeloid cell line U937 was evaluated as an in vitro test system to identify contact sensitizers in order to develop alternatives to animal tests for the cosmetic industry. Specific culture conditions (i.e., presence of interleukin-4, IL-4) were applied to obtain a dendritic cell-like phenotype. In the described test protocol, these cells were exposed to test chemicals and then analyzed by flow cytometry for CD86 expression and by quantitative real-time reverse transcriptase-polymerase chain reaction for IL-1{beta} and IL-8 gene expressions. Eight sensitizers, three non-sensitizers and five oxidative hair dye precursors were examined after 24-, 48- and 72-h exposure times. Test item-specific modulations of the chosen activation markers (CD86, IL-1{beta} and IL-8) suggest that this U937 activation test could discriminate test items classified as contact sensitizers or non-sensitizers in the local lymph node assay in mice (LLNA). More specifically, a test item can be considered as a potential sensitizer when it significantly induced the upregulation of the expression of at least two markers. Using this approach, we could correctly evaluate the dendritic cell (DC) activation potential for 15 out of 16 tested chemicals. We conclude that the U937 activation test may represent an useful tool in a future in vitro test battery for predicting sensitizing properties of chemicals.

  12. Pinning of the Contact Line during Evaporation on Heterogeneous Surfaces: Slowdown or Temporary Immobilization? Insights from a Nanoscale Study.

    PubMed

    Zhang, Jianguo; Müller-Plathe, Florian; Leroy, Frédéric

    2015-07-14

    The question of the effect of surface heterogeneities on the evaporation of liquid droplets from solid surfaces is addressed through nonequilibrium molecular dynamics simulations. The mechanism behind contact line pinning which is still unclear is discussed in detail on the nanoscale. Model systems with the Lennard-Jones interaction potential were employed to study the evaporation of nanometer-sized cylindrical droplets from a flat surface. The heterogeneity of the surface was modeled through alternating stripes of equal width but two chemical types. The first type leads to a contact angle of 67°, and the other leads to a contact angle of 115°. The stripe width was varied between 2 and 20 liquid-particle diameters. On the surface with the narrowest stripes, evaporation occurred at constant contact angle as if the surface was homogeneous, with a value of the contact angle as predicted by the regular Cassie-Baxter equation. When the width was increased, the contact angle oscillated during evaporation between two boundaries whose values depend on the stripe width. The evaporation behavior was thus found to be a direct signature of the typical size of the surface heterogeneity domains. The contact angle both at equilibrium and during evaporation could be predicted from a local Cassie-Baxter equation in which the surface composition within a distance of seven fluid-particle diameters around the contact line was considered, confirming the local nature of the interactions that drive the wetting behavior of droplets. More importantly, we propose a nanoscale explanation of pinning during evaporation. Pinning should be interpreted as a drastic slowdown of the contact line dynamics rather than a complete immobilization of it during a transition between two contact angle boundaries.

  13. Particle trap to sheath non-binding contact for a gas-insulated transmission line having a corrugated outer conductor

    DOEpatents

    Fischer, William H.

    1984-04-24

    A non-binding particle trap to outer sheath contact for use in gas insulated transmission lines having a corrugated outer conductor. The non-binding feature of the contact according to the teachings of the invention is accomplished by having a lever arm rotatably attached to a particle trap by a pivot support axis disposed parallel to the direction of travel of the inner conductor/insulator/particle trap assembly.

  14. A three-dimensional volume-of-fluid method for reconstructing and advecting three-material interfaces forming contact lines

    NASA Astrophysics Data System (ADS)

    Pathak, Ashish; Raessi, Mehdi

    2016-02-01

    We introduce a piecewise-linear, volume-of-fluid method for reconstructing and advecting three-dimensional interfaces and contact lines formed by three materials. The new method employs a set of geometric constructs that can be used in conjunction with any volume-tracking scheme. In this work, we used the mass-conserving scheme of Youngs to handle two-material cells, perform interface reconstruction in three-material cells, and resolve the contact line. The only information required by the method is the available volume fraction field. Although the proposed method is order dependent and requires a priori information on material ordering, it is suitable for typical contact line applications, where the material representing the contact surface is always known. Following the reconstruction of the contact surface, to compute the interface orientation in a three-material cell, the proposed method minimizes an error function that is based on volume fraction distribution around that cell. As an option, the minimization procedure also allows the user to impose a contact angle. Performance of the proposed method is assessed via both static and advection test cases. The tests show that the new method preserves the accuracy and mass-conserving property of the Youngs method in volume-tracking three materials.

  15. Fluid structure in the immediate vicinity of an equilibrium contact line from first principles and assessment of disjoining pressure models

    NASA Astrophysics Data System (ADS)

    Nold, Andreas; Sibley, David N.; Goddard, Benjamin D.; Kalliadasis, Serafim

    2014-11-01

    Predicting the fluid structure at a three-phase contact line of macroscopic drops is of interest from a fundamental fluid dynamics point of view. However, exact computations for very small scales are prohibitive. As a consequence, coarse-grained quantities such as interface height and disjoining pressure profiles are used to model the interface shape. Here, we evaluate such coarse-grained models within a rigorous and self-consistent framework based on statistical mechanics, in particular with a Density Functional Theory (DFT) approach. We examine the nanoscale behavior of an equilibrium three-phase contact line in the presence of long-ranged intermolecular forces by employing DFT together with fundamental measure theory. Our analysis also enables us to evaluate the predictive quality of effective Hamiltonian models in the vicinity of the contact line. We compare the results for mean field effective Hamiltonians with disjoining pressures defined through the adsorption isotherm for a planar liquid film, and the normal force balance at the contact line [Phys. Fluids, 26, 072001, 2014]. Results are given for a variety of contact angles. An accurate description of the small-scale behavior of a three-phase conjunction is a prerequisite to understanding dynamic wetting phenomena.

  16. Effect of sodium dodecylbenzene sulfonate on the motion of three-phase contact lines on the Wilhelmy plate surface.

    PubMed

    Karakashev, Stoyan I; Phan, Chi M; Nguyen, Anh V

    2005-11-15

    The combined approach of the molecular-kinetic and hydrodynamic theories for description of the motion of three-phase gas-liquid-solid contact lines has been examined using the Wilhelmy plate method. The whole dynamic meniscus has been divided into molecular, hydrodynamic, and static-like regions. The Young-Laplace equation and the molecular-kinetic and hydrodynamic dewetting theories have been applied to describe the meniscus profiles and contact angle. The dissipative forces accompanying the dynamic dewetting have also been investigated. The experiments with a Wilhelmy plate made from an acrylic polymer sheet were carried out using a computerized apparatus for contact angle analysis (OCA 20, DataPhysics, Germany). The extrapolated dynamic contact angle versus velocity of the three-phase contact line for Milli-Q water and 5x10(-4) M SDBS solution was experimentally obtained and compared with the combined MHD models with low and moderate Reynolds numbers. The models predict similar results for the extrapolated contact angle. SDBS decreases the equilibrium contact angle and increases the molecular jumping length but does not affect the molecular frequency significantly. The hydrodynamic deformation of the meniscus, viscous dissipation, and friction were also influenced by the SDBS surfactant.

  17. Free-Surface and Contact Line Motion of Liquid in Microgravity

    NASA Technical Reports Server (NTRS)

    Schwartz, Leonard W.

    1996-01-01

    This project involves fundamental studies of the role of nonlinearity in determining the motion of liquid masses under the principal influences of surface tension, viscosity and inertia. Issues to be explored are relevant to aspects of terrestrial processes, as well as being immediately applicable to fluid management in a low-gravity environment. Specific issues include: (1) the mechanic's of liquid masses in large-amplitude motions, (2) the influence of bounding surfaces on the motion, and (3) the ability of such surfaces to control liquid motion by wetting forces, especially when they are augmented by various surface treatments. Mathematical techniques include asymptotic analysis of the governing equations, for problem simplification, and numerical simulation, using both boundary-element and finite-difference methods. The flow problem is divided into an 'outer' or inviscid potential-flow region and one or more inner, or viscous dominated, regions. Relevant to one inner region, the vicinity of the contact line, we discuss time-dependent simulation of slow droplet motion, on a surface of variable wettability, using the lubrication approximation. The simulation uses a disjoining pressure model and reproduces realistic wetting-dewetting behavior.

  18. Geometrical Description of Contact Line Fluctuations in Heterogeneous Systems with Controlled Wettability.

    PubMed

    Araujo; Araujo

    2000-09-01

    The understanding of contact line fluctuations in heterogeneous systems of controlled wettability is relevant to many industrial processes. Despite its importance, it is poorly understood. Here, we present results on an experimental study of fluid displacement on modified Hele-Shaw cells with surface defects as heterogeneities. The system wettability is controlled by defect surface coverage. Three different surface coverage regimes were studied. For each one, the morphology and deformation energy of the displacement front is determined. The width front is described in terms of two exponents, the roughness exponent (alpha) and the one that describes its growth (beta). In all cases, it is found that the width increases logarithmically in time up to a characteristic value, where a crossover to a saturation behavior is observed. The crossover time is a function of the surface coverage. For low coverage 0.51

  19. Study on overlay AEI-ADI shift on contact layer of advanced technology node

    NASA Astrophysics Data System (ADS)

    Deng, Guogui; Hao, Jingan; Xiao, Lihong; Xing, Bin; Jiang, Yuntao; He, Kaiting; Zhang, Qiang; He, Weiming; Liu, Chang; Lin, Yi-Shih; Wu, Qiang; Shi, Xuelong

    2016-03-01

    In this paper, we present a study on the overlay (OVL) shift issue in contact (CT) layer aligned to poly-silicon (short as poly) layer (prior layer) in an advanced technology node [1, 2]. We have showed the wafer level OVL AEI-ADI shift (AEI: After Etch Inspection; ADI: After Developing Inspection; AEI-ADI: AEI minus ADI). Within the shot level map, there exists a center-edge difference. The OVL focus subtraction map can well match the OVL AEI-ADI shift map. Investigation into this interesting correlation finally leads to the conclusion of PR tilt. The film stress of the thick hard mask is responsible for the PR tilt. The method of OVL focus subtraction can therefore be a powerful and convenient tool to represent the OVL mark profile. It is also important to take into account the film deposition when investigating OVL AEI-ADI shift.

  20. Apparent dynamic contact angle of an advancing gas--liquid meniscus

    SciTech Connect

    Kalliadasis, S.; Chang, H. )

    1994-01-01

    The steady motion of an advancing meniscus in a gas-filled capillary tube involves a delicate balance of capillary, viscous, and intermolecular forces. The limit of small capillary numbers Ca (dimensionless speeds) is analyzed here with a matched asymptotic analysis that links the outer capillary region to the precursor film in front of the meniscus through a lubricating film. The meniscus shape in the outer region is constructed and the apparent dynamic contact angle [Theta] that the meniscus forms with the solid surface is derived as a function of the capillary number, the capillary radius, and the Hamaker's constant for intermolecular forces, under conditions of weak gas--solid interaction, which lead to fast spreading of the precursor film and weak intermolecular forces relative to viscous forces within the lubricating film. The dependence on intermolecular forces is very weak and the contact angle expression has a tight upper bound tan [Theta]=7.48 Ca[sup 1/3] for thick films, which is independent of the Hamaker constant. This upper bound is in very good agreement with existing experimental data for wetting fluids in any capillary and for partially wetting fluids in a prewetted capillary. Significant correction to the Ca[sup 1/3] dependence occurs only at very low Ca, where the intermolecular forces become more important and tan [Theta] diverges slightly from the above asymptotic behavior toward lower values.

  1. Capillary forces exerted by liquid drops caught between crossed cylinders. A 3-D meniscus problem with free contact line

    NASA Technical Reports Server (NTRS)

    Patzek, T. W.; Scriven, L. E.

    1982-01-01

    The Young-Laplace equation is solved for three-dimensional menisci between crossed cylinders, with either the contact line fixed or the contact angle prescribed, by means of the Galerkin/finite element method. Shapes are computed, and with them the practically important quantities: drop volume, wetted area, capillary pressure force, surface tension force, and the total force exerted by the drop on each cylinder. The results show that total capillary force between cylinders increases with decreasing contact angle, i.e. with better wetting. Capillary force is also increases with decreasing drop volume, approaching an asymptotic limit. However, the wetted area on each cylinder decreases with decreasing drop volume, which raises the question of the optimum drop volume to strive for, when permanent bonding is sought from solidified liquid. For then the strength of the bond is likely to depend upon the area of contact, which is the wetted area when the bonding agent was introduced in liquid form.

  2. Development and testing of new biologically-based polymers as advanced biocompatible contact lenses

    SciTech Connect

    Bertozzi, Carolyn R.

    2000-06-01

    Nature has evolved complex and elegant materials well suited to fulfill a myriad of functions. Lubricants, structural scaffolds and protective sheaths can all be found in nature, and these provide a rich source of inspiration for the rational design of materials for biomedical applications. Many biological materials are based in some fashion on hydrogels, the crosslinked polymers that absorb and hold water. Biological hydrogels contribute to processes as diverse as mineral nucleation during bone growth and protection and hydration of the cell surface. The carbohydrate layer that coats all living cells, often referred to as the glycocalyx, has hydrogel-like properties that keep cell surfaces well hydrated, segregated from neighboring cells, and resistant to non-specific protein deposition. With the molecular details of cell surface carbohydrates now in hand, adaptation of these structural motifs to synthetic materials is an appealing strategy for improving biocompatibility. The goal of this collaborative project between Prof. Bertozzi's research group, the Center for Advanced Materials at Lawrence Berkeley National Laboratory and Sunsoft Corporation was the design, synthesis and characterization of novel hydrogel polymers for improved soft contact lens materials. Our efforts were motivated by the urgent need for improved materials that allow extended wear, and essential feature for those whose occupation requires the use of contact lenses rather than traditional spectacles. Our strategy was to transplant the chemical features of cell surface molecules into contact lens materials so that they more closely resemble the tissue in which they reside. Specifically, we integrated carbohydrate molecules similar to those found on cell surfaces, and sulfoxide materials inspired by the properties of the carbohydrates, into hydrogels composed of biocompatible and manufacturable substrates. The new materials were characterized with respect to surface and bulk hydrophilicity, and

  3. Residential magnetic fields, contact voltage and their relationship: the effects of distribution unbalance and residential proximity to a transmission line.

    PubMed

    Kavet, Robert; Daigle, Jeff P; Zaffanella, Luciano E

    2006-12-01

    In previous studies, modeling and measurements have suggested a positive relationship between the average residential magnetic field (B(avg)) and the voltage from the residential water line to earth (V(W-E)). This voltage is the source of exposure to contact current that has been hypothesized to behave as a confounder with respect to the association between residential magnetic fields and childhood leukemia. The previous modeling effort has only considered the influence of distribution lines on the B(avg):V(W-E) relationship. This study extends that analysis to include the effect of distribution line unbalance and the presence of nearby transmission lines. The results show that, compared to balanced systems, unbalanced distribution systems had increased B(avg) and V(W-E), with a relatively greater effect on (VW-E). The presence of a transmission line proportionally increased B(avg) and V(W-E) more on balanced systems than unbalanced systems and attenuated the relationship of B(avg) with V(W-E) on systems with 25% unbalance. Increases in B(avg) due to the transmission line were confined to distances within 100-200 m of the line, but increases in V(W-E) extended to the furthest distance included in the model (365 m). The observations reported may be relevant to prior epidemiological studies of magnetic fields and childhood leukemia, and suggest that research efforts continue to explore the role of contact current in potentially explaining those studies.

  4. Pressure drop of two-phase dry-plug flow in round mini-channels: Effect of moving contact line

    SciTech Connect

    Lee, Chi Young; Lee, Sang Yong

    2010-01-15

    In the present experimental study, the pressure drop of the two-phase dry-plug flow (dry wall condition at the gas portions) in round mini-channels was investigated. The air-water mixtures were flowed through the round mini-channels made of polyurethane and Teflon, respectively, with their inner diameters ranging from 1.62 to 2.16 mm. In the dry-plug flow regime, the pressure drop measured became larger either by increasing the liquid superficial velocity or by decreasing the gas superficial velocity due to the increase of the number of the moving contact lines in the test section. In such a case, the role of the moving contact lines turned out to be significant. Therefore, a pressure drop model of dry-plug flow was proposed through modification of the dynamic contact angle analysis taking account of the energy dissipation by the moving contact lines, which represents the experimental data within the mean deviation of 4%. (author)

  5. Caustics and Caustic-Diffraction in Laser Shadowgraphy of a Sessile Drop and Identification of Profile Near Contact Line

    NASA Technical Reports Server (NTRS)

    Zhang, Neng-Li; Chao, David F.

    2003-01-01

    This paper presents an optical method based on the caustics and caustic-difraction in laser shadowgaphy of a sessile drop to identify and estimate the drop profile near the contact line. A parallel laser beam passes through a liquid sessile drop placed on a transparent substrate to produce a shadowgraphic image of the drop on the screen far from the substrate. Along the inflection line of the drop the Gaussian curvature of the wavefront deformed by the drop vanishes, and therefore the inflection line gives caustics in the far field of the wave, which can be seen on the screen. The neighboring light rays at both sides of the inflection line interfere with each other to form interference fringes at the inner side of the caustics. According to the pattern of the caustics, the drop-profile shape can be identified and estimated.

  6. Particle Segregation at Contact Lines of Evaporating Colloidal Drops: Influence of the Substrate Wettability and Particle Charge-Mass Ratio.

    PubMed

    Noguera-Marín, Diego; Moraila-Martínez, Carmen L; Cabrerizo-Vílchez, Miguel A; Rodríguez-Valverde, Miguel A

    2015-06-23

    Segregation of particles during capillary/convective self-assembly is interesting for self-stratification in colloidal deposits. In evaporating drops containing colloidal particles, the wettability properties of substrate and the sedimentation of particles can affect their accumulation at contact lines. In this work we studied the size segregation and discrimination of charged particles with different densities. We performed in-plane particle counting at evaporating triple lines by using fluorescence confocal microscopy. We studied separately substrates with very different wettability properties and particles with different charge-mass ratios at low ionic strength. We used binary colloidal suspensions to compare simultaneously the deposition of two different particles. The particle deposition rate strongly depends on the receding contact angle of the substrate. We further observed a singular behavior of charged polystyrene particles in binary mixtures under "salt-free" conditions explained by the "colloidal Brazil nut" effect.

  7. Ultra-thin dielectric insertions for contact resistivity lowering in advanced CMOS: Promises and challenges

    NASA Astrophysics Data System (ADS)

    Borrel, Julien; Hutin, Louis; Kava, Donato; Gassilloud, Remy; Bernier, Nicolas; Morand, Yves; Nemouchi, Fabrice; Gregoire, Magali; Dubois, Emmanuel; Vinet, Maud

    2017-04-01

    In this paper, in order to provide a comprehensive overview of the opportunities and limitations of the metal/insulator/semiconductor contacts approach, expected performance based on ideal contact simulations as well as key practical aspects are presented. While the former give us a glimpse of the theoretical potential of this paradigm, mainly to contact nFETs, the latter highlights concerns about the electrical characterization of such contacts along with issues occurring during their physical implementation.

  8. Experimental study of the heated contact line region for a pure fluid and binary fluid mixture in microgravity.

    PubMed

    Nguyen, Thao T T; Kundan, Akshay; Wayner, Peter C; Plawsky, Joel L; Chao, David F; Sicker, Ronald J

    2017-02-15

    Understanding the dynamics of phase change heat and mass transfer in the three-phase contact line region is a critical step toward improving the efficiency of phase change processes. Phase change becomes especially complicated when a fluid mixture is used. In this paper, a wickless heat pipe was operated on the International Space Station (ISS) to study the contact line dynamics of a pentane/isohexane mixture. Different interfacial regions were identified, compared, and studied. Using high resolution (50×), interference images, we calculated the curvature gradient of the liquid-vapor interface at the contact line region along the edges of the heat pipe. We found that the curvature gradient in the evaporation region increases with increasing heat flux magnitude and decreasing pentane concentration. The curvature gradient for the mixture case is larger than for the pure pentane case. The difference between the two cases increases as pentane concentration decreases. Our data showed that the curvature gradient profile within the evaporation section is separated into two regions with the boundary between the two corresponding to the location of a thick, liquid, "central drop" region at the point of maximum internal local heat flux. We found that the curvature gradients at the central drop and on the flat surfaces where condensation begins are one order of magnitude smaller than the gradients in the corner meniscus indicating the driving forces for fluid flow are much larger in the corners.

  9. Raman mapping using advanced line-scanning systems: geological applications.

    PubMed

    Bernard, Sylvain; Beyssac, Olivier; Benzerara, Karim

    2008-11-01

    By allowing nondestructive chemical and structural imaging of heterogeneous samples with a micrometer spatial resolution, Raman mapping offers unique capabilities for assessing the spatial distribution of both mineral and organic phases within geological samples. Recently developed line-scanning Raman mapping techniques have made it possible to acquire Raman maps over large, millimeter-sized, zones of interest owing to a drastic decrease of the data acquisition time without losing spatial or spectral resolution. The synchronization of charge-coupled device (CCD) measurements with x,y motorized stage displacement has allowed dynamic line-scanning Raman mapping to be even more efficient: total acquisition time may be reduced by a factor higher than 100 compared to point-by-point mapping. Using two chemically and texturally complex geological samples, a fossil megaspore in a metamorphic rock and aragonite-garnet intergrowths in an Eclogitic marble, we compare here two recent versions of line-scanning Raman mapping systems and discuss their respective advantages and disadvantages in terms of acquisition time, image quality, spatial and imaging resolutions, and signal-to-noise ratio. We show that line-scanning Raman mapping techniques are particularly suitable for the characterization of such samples, which are representative of the general complexity of geological samples.

  10. Wetting and contact-line effects for spherical and cylindrical droplets on graphene layers: a comparative molecular-dynamics investigation.

    PubMed

    Scocchi, Giulio; Sergi, Danilo; D'Angelo, Claudio; Ortona, Alberto

    2011-12-01

    In molecular dynamics (MD) simulations, interactions between water molecules and graphitic surfaces are often modeled as a simple Lennard-Jones potential between oxygen and carbon atoms. A possible method for tuning this parameter consists of simulating a water nanodroplet on a flat graphitic surface, measuring the equilibrium contact angle, extrapolating it to the limit of a macroscopic droplet, and finally matching this quantity to experimental results. Considering recent evidence demonstrating that the contact angle of water on a graphitic plane is much higher than what was previously reported, we estimate the oxygen-carbon interaction for the recent SPC/Fw water model. Results indicate a value of about 0.2 kJ/mol, much lower than previous estimations. We then perform simulations of cylindrical water filaments on graphitic surfaces, in order to compare and correlate contact angles resulting from these two different systems. Results suggest that a modified Young's equation does not describe the relation between contact angle and drop size in the case of extremely small systems and that contributions different from the one deriving from contact line tension should be taken into account.

  11. Cell line development for biomanufacturing processes: recent advances and an outlook.

    PubMed

    Le, Huong; Vishwanathan, Nandita; Jacob, Nitya M; Gadgil, Mugdha; Hu, Wei-Shou

    2015-08-01

    At the core of a biomanufacturing process for recombinant proteins is the production cell line. It influences the productivity and product quality. Its characteristics also dictate process development, as the process is optimized to complement the producing cell to achieve the target productivity and quality. Advances in the past decade, from vector design to cell line screening, have greatly expanded our capability to attain producing cell lines with certain desired traits. Increasing availability of genomic and transcriptomic resources for industrially important cell lines coupled with advances in genome editing technology have opened new avenues for cell line development. These developments are poised to help biosimilar manufacturing, which requires targeting pre-defined product quality attributes, e.g., glycoform, to match the innovator's range. This review summarizes recent advances and discusses future possibilities in this area.

  12. Singularité anguleuse d'une ligne de contact en mouvement sur un substrat solideCorner singularity of a contact line moving on a solid substrate

    NASA Astrophysics Data System (ADS)

    Stone, Howard A.; Limat, Laurent; Wilson, Stephen K.; Flesselles, J.-M.; Podgorski, Thomas

    In conditions of partial wetting and at sufficiently high capillary number Ca, a dynamic contact line that recedes on a solid surface assumes a 'saw-tooth' shape. We show that the flow inside this liquid 'corner' is a similarity solution of the lubrication equations governing steady thin-film flows in which the free surface is cone shaped. The interface slope Ω defined in its symmetry plane is linked to the corner angle 2 φ by the approximate relationship Ω 3≈(3/2) Catan2φ . We also suggest a possible explanation of droplet emission from the corner which occurs when φ reaches π/6. To cite this article: H.A. Stone et al., C. R. Physique 3 (2002) 103-110

  13. Advanced DFM application for automated bit-line pattern dummy

    NASA Astrophysics Data System (ADS)

    Shin, Tae Hyun; Kim, Cheolkyun; Yang, Hyunjo; Bahr, Mohamed

    2016-03-01

    This paper presents an automated DFM solution to generate Bit Line Pattern Dummy (BLPD) for memory devices. Dummy shapes are aligned with memory functional bits to ensure uniform and reliable memory device. This paper will present a smarter approach that uses an analysis based technique for adding the dummy shapes that have different types according to the space available. Experimental results based on layout of Mobile dynamic random access memory (DRAM).

  14. The influence of strain hardening on cumulative plastic deformation in rolling and sliding line contact

    NASA Astrophysics Data System (ADS)

    Bower, A. F.; Johnson, K. L.

    THE INFLUENCE of strain hardening on the cumulative plastic deformation (ratchetting) which takes place in repeated rolling and sliding contacts has been assessed by the use of a non-linear kinematic hardening law proposed and tested by B OWER ( J. Mech. Phys. Solids37,455, 1989). Both the sub-surface flow, which occurs at low traction coefficients ( <0.25), and the surface flow which occurs at high traction ( >0.25), have been investigated. Two materials have been studied: hard-drawn copper and rail steel. Good correlation was found for copper between the theory and rolling contact experiments.

  15. Disease evaluations and agronomic traits of advanced peanut breeding lines in 2012

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A total of 38 peanut cultivars and high-oleic advanced breeding lines were evaluated in small field plots in 2012 for yield, seed grade and size, and resistance to Sclerotinia minor and Sclerotium rolfsii. Among the 14 Spanish entries, the cultivar Tamnut 06 (3258 lbs/acre) and breeding line 140-1O...

  16. Contact angle hysteresis of microbead suspensions.

    PubMed

    Waghmare, Prashant R; Mitra, Sushanta K

    2010-11-16

    Microbead suspensions are often used in microfluidic devices for transporting biomolecules. An experimental investigation on the wettability of microbead suspension is presented in this study. The variation in the surface tension and the equilibrium contact angle with the change in the volume fraction of the microbead is presented here. The surface tension of the microbead suspension is measured with the pendant drop technique, whereas the dynamic contact angle measurements, i.e., advancing and receding contact angles, are measured with the sessile drop technique. An equilibrium contact angle of a suspension with particular volume fraction is determined by computing an average over the measured advancing and receding contact angles. It is observed that the surface tension and the equilibrium contact angle determined from advancing and receding contact angles vary with the magnitude of the microbeads volume fraction in the suspension. A decrease in the surface tension with an increase in the volume fraction of the microbead suspension is observed. The advancement and the recession in contact line for dynamic contact angle measurements are achieved with the motorized dosing mechanism. For microbead suspensions, the advancement of the contact line is faster as compared to the recession of the contact line for the same flow rate. The presence of microbeads assists in the advancement and the recession of the contact line of the suspension. A decrease in the equilibrium contact angles with an increase in the microbead suspension volume fraction is observed. Inclusion of microbeads in the suspension increases the wetting capability for the considered combination of the microbead suspension and substrate. Finally, empirical correlations for the surface tension and the contact angle of the suspension as a function of microbead volume fraction are proposed. Such correlations can readily be used to develop mechanistic models for the capillary transport of microbead

  17. Tele-autonomous control involving contacts: The applications of a high precision laser line range sensor

    NASA Technical Reports Server (NTRS)

    Volz, R. A.; Shao, L.; Walker, M. W.; Conway, L. A.

    1989-01-01

    The object localization algorithm based on line-segment matching is presented. The method is very simple and computationally fast. In most cases, closed-form formulas are used to derive the solution. The method is also quite flexible, because only few surfaces (one or two) need to be accessed (sensed) to gather necessary range data. For example, if the line-segments are extracted from boundaries of a planar surface, only parameters of one surface and two of its boundaries need to be extracted, as compared with traditional point-surface matching or line-surface matching algorithms which need to access at least three surfaces in order to locate a planar object. Therefore, this method is especially suitable for applications when an object is surrounded by many other work pieces and most of the object is very difficult, is not impossible, to be measured; or when not all parts of the object can be reached. The theoretical ground on how to use line range sensor to located an object was laid. Much work has to be done in order to be really useful.

  18. Radiolucent lines in low-contact-stress mobile-bearing total knee arthroplasty: a blinded and matched case control study

    PubMed Central

    2011-01-01

    Background Low-contact-stress (LCS) mobile-bearing total knee arthroplasty (TKA) (Johnson & Johnson, New Brunswick, NJ; previously: DePuy, Warsawa, USA) provides excellent functional results and wear rates in long-term follow-up analyses. Radiological analysis shows radiolucent lines (RLL) appearing immediately or two years after primary implantation, indicative of poor seat. Investigations proved RLL to be more frequent in uncemented TKA, resulting in a consensus to cement the tibial plateau, but their association with clinical findings and patients discomfort and knee pain is still unknown. Methods 553 patients with 566 low-contact-stress (LCS) total knee prostheses were screened for continuous moderate knee pain. We compared tibial stress shielding classified by Ewald in patients suffering from pain with a matched, pain-free control group on blinded X-rays. We hypothesized a positive correlation between pain and radiolucency and higher frequency of such radiolucent lines in the most medial and most lateral zones of the tibial plateau. Results Twenty-eight patients suffered from knee pain in total. Radiolucencies were detected in 27 of these cases and in six out of 28 matched controls without knee pain. We could demonstrate a significant correlation of knee pain and radiolucencies, which appeared significantly more frequently in the outermost zones of the tibial plateau. Conclusion Our findings suggest that radiolucent lines, representing poor implant seat, about the tibial plateau are associated with knee pain in LCS patients. Radiolucencies are observed more often in noncemented LCS, and cementing the tibial plateau might improve implant seat and reduce both radiolucent lines and associated knee pain. PMID:21714916

  19. Current densities and total contact currents for 110 and 220 kV power line tasks.

    PubMed

    Korpinen, Leena; Kuisti, Harri; Elovaara, Jarmo

    2014-10-01

    The aim of this study was to analyze all values of electric current from measured periods while performing tasks on 110 and 220 kV power lines. Additionally, the objective was to study the average current densities and average total contact currents caused by electric fields in 110 and 220 kV power line tasks. One worker simulated the following tasks: (A) tested insulation voltage at a 110 kV portal tower, (B) checked the wooden towers for rot at a 110 kV portal tower, (C) tested insulation voltage at a 220 kV portal tower, and (D) checked the wooden towers for rot at a 220 kV portal tower. The highest average current density in the neck was 2.0 mA/m(2) (calculated internal electric field was 19.0-38.0 mV/m), and the highest average contact current was 234 µA. All measured values at 110 and 220 kV towers were lower than the basic restrictions (0.1 and 0.8 V/m) of the International Commission on Non-ionizing Radiation Protection.

  20. Pairwise Force Smoothed Particle Hydrodynamics model for multiphase flow: Surface tension and contact line dynamics

    SciTech Connect

    Tartakovsky, Alexandre M.; Panchenko, Alexander

    2016-01-01

    We present a novel formulation of the Pairwise Force Smoothed Particle Hydrodynamics Model (PF-SPH) and use it to simulate two- and three-phase flows in bounded domains. In the PF-SPH model, the Navier-Stokes equations are discretized with the Smoothed Particle Hydrodynamics (SPH) method and the Young-Laplace boundary condition at the fluid-fluid interface and the Young boundary condition at the fluid-fluid-solid interface are replaced with pairwise forces added into the Navier-Stokes equations. We derive a relationship between the parameters in the pairwise forces and the surface tension and static contact angle. Next, we demonstrate the accuracy of the model under static and dynamic conditions. Finally, to demonstrate the capabilities and robustness of the model we use it to simulate flow of three fluids in a porous material.

  1. Pairwise Force Smoothed Particle Hydrodynamics model for multiphase flow: Surface tension and contact line dynamics

    NASA Astrophysics Data System (ADS)

    Tartakovsky, Alexandre M.; Panchenko, Alexander

    2016-01-01

    We present a novel formulation of the Pairwise Force Smoothed Particle Hydrodynamics (PF-SPH) model and use it to simulate two- and three-phase flows in bounded domains. In the PF-SPH model, the Navier-Stokes equations are discretized with the Smoothed Particle Hydrodynamics (SPH) method, and the Young-Laplace boundary condition at the fluid-fluid interface and the Young boundary condition at the fluid-fluid-solid interface are replaced with pairwise forces added into the Navier-Stokes equations. We derive a relationship between the parameters in the pairwise forces and the surface tension and static contact angle. Next, we demonstrate the model's accuracy under static and dynamic conditions. Finally, we use the Pf-SPH model to simulate three phase flow in a porous medium.

  2. Tailoring graphene oxide assemblies by pinning on the contact line of a dissolving microdroplet.

    PubMed

    Yang, Haijun; Song, Yuting; Downton, Matthew T; Wang, Songtao; Xu, Jianxin; Hou, Zhengchi; Zhang, Xuehua

    2015-11-21

    The controlled dissolution of microdroplets on a supporting substrate is an effective approach that can be used to tune the assembled microstructure of basic units suspended within the droplet. In this work, we studied the self-assembly of two-dimensional graphene oxide (GO) nanosheets driven by the dissolution of a microdroplet situated at the interface between a solid substrate and the surrounding liquid phase. We found that although uniform microstructures form at the liquid-liquid interface of the droplets, the contact between the droplet and the substrate can give rise to a variety of different morphologies near the base of the droplet. In particular, pinning effects at the boundary of the dissolving droplet on the substrate lead to non-spherical GO assemblies. The results in this work demonstrate the possibility that tailored three-dimensional architectures of nanosheets assembled in a dissolving droplet may be achieved through control of the wetting properties of the droplet on the supporting substrate.

  3. Disease evaluations and agronomic traits of advanced peanut breeding lines in 2016

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Peanut disease evaluations of advanced breeding lines are conducted annually to compare the agronomic traits (crop value, yield, seed grade, and characteristics) and disease resistance of cultivars that are currently available or close to being released for the Southwest. In 2016, a total of 21 com...

  4. Disease evaluations and agronomic traits of advanced peanut breeding lines in 2015

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A total of 20 commercially available peanut cultivars and high-oleic advanced breeding lines were evaluated in small field plots in 2015 for agronomic traits (crop value, yield, seed grade, and characteristics). Environmental conditions in 2015 were not favorable for Sclerotinia blight, southern bl...

  5. Disease evaluations and agronomic traits of advanced peanut breeding lines in 2014

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A total of 23 commercially available peanut cultivars and high-oleic advanced breeding lines were evaluated in small field plots in 2014 for agronomic traits (crop value, yield, seed grade, and characteristics) and resistance to soilborne diseases. Among the 16 runner entries evaluated, Tamrun OL11...

  6. Disease evaluations and agronomic traits of advanced peanut breeding lines in 2013

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A total of 21 peanut cultivars and high-oleic advanced breeding lines were evaluated in small field plots in 2013 for agronomic traits (crop value, yield, seed grade, and characteristics) and resistance to diseases (Sclerotinia blight, southern blight, and Pythium and Rhizoctonia pod rot). Among th...

  7. Evaluation of advanced microelectronic fluxless solder-bump contacts for hybrid microcircuits

    NASA Technical Reports Server (NTRS)

    Mandal, R. P.

    1976-01-01

    Technology for interconnecting monolithic integrated circuit chips with other components is investigated. The advantages and disadvantages of the current flip-chip approach as compared to other interconnection methods are outlined. A fluxless solder-bump contact technology is evaluated. Multiple solder-bump contacts were formed on silicon integrated circuit chips. The solder-bumps, comprised of a rigid nickel under layer and a compliant solder overlayer, were electroformed onto gold device pads with the aid of thick dry film photomasks. Different solder alloys and the use of conductive epoxy for bonding were explored. Fluxless solder-bump bond quality and reliability were evaluated by measuring the effects of centrifuge, thermal cycling, and high temperature storage on bond visual characteristics, bond electrical continuity, and bond shear tests. The applicability and suitability of this technology for hybrid microelectronic packaging is discussed.

  8. Advanced characterization of carrier profiles in germanium using micro-machined contact probes

    NASA Astrophysics Data System (ADS)

    Clarysse, T.; Konttinen, M.; Parmentier, B.; Moussa, A.; Vandervorst, W.; Impellizzeri, G.; Napolitani, E.; Privitera, V.; Nielsen, P. F.; Petersen, D. H.; Hansen, O.

    2012-11-01

    The accurate determination of the sheet resistance and carrier depth profile, i.e. active dopant profile, of shallow junction isolated structures involving new high mobility materials, such as germanium, is a crucial topic for future CMOS development. In this work, we discuss the capabilities of new concepts based on micro machined, closely spaced contact probes (10 μm pitch). When using four probes to perform sheet resistance measurements, a quantitative carrier profile extraction based on the evolution of the sheet resistance versus depth along a beveled surface is obtained. Considering the use of only two probes, a spreading resistance like setup is obtained with small spacing and drastically reduced electrical contact radii (˜10 nm) leading to a substantial reduction of the correction factors which are normally required for converting spreading resistance profiles. We demonstrate the properties of both approaches on Al+ implants in germanium with different anneal treatments.

  9. Considerations on the moving contact-line singularity, with application to frictional drag on a slender drop

    NASA Technical Reports Server (NTRS)

    Durbin, P. A.

    1988-01-01

    It has previously been shown that the no-slip boundary conditions leads to a singularity at a moving contact line and that this presumes some form of slip. Present considerations on the energetics of slip due to shear stress lead to a yield stress boundary condition. A model for the distortion of the liquid state near solid boundaries gives a physical basis for this boundary condition. The yield stress condition is illustrated by an analysis of a slender drop rolling down an incline. That analysis provides a formula for the frictional drag resisting the drop movement. With the present boundary condition, the length of the slip region becomes a property of the fluid flow.

  10. Contact Line Dynamics during the Evaporation of Extended Colloidal Thin Films: Influence of Liquid Polarity and Particle Size.

    PubMed

    Ghosh, Udita Uday; Chakraborty, Monojit; De, Soham; Chakraborty, Suman; DasGupta, Sunando

    2016-12-06

    Exercising control over the evaporation of colloidal suspensions is pivotal to modulate the coating characteristics for specific uses, wherein the interactions among the liquid, the particles, and the substrate control the process. In the present study, the contact line dynamics of a receding colloidal liquid film consisting of particles of distinctly different sizes (nominal diameters 0.055 and 1 μm and surface unmodified) during evaporation is analyzed. The role of the liquid polarity is also investigated by replacing the polar liquid (water) with a relatively nonpolar liquid (isopropyl alcohol) in the colloidal suspension. The characteristics of the evaporating receding meniscus, namely, the film thickness and the curvature are experimentally evaluated using an image-analyzing interferometry technique. The experimental results are assessed in conjunction with the augmented Young-Laplace equation, highlighting the roles of the relevant components of the disjoining pressure and the polarity of the liquid involved in the colloidal suspension.

  11. Vapor bridges between solid substrates in the presence of the contact line pinning effect: Stability and capillary force

    NASA Astrophysics Data System (ADS)

    Liu, Yawei; Zhang, Xianren

    2016-12-01

    In this work, we focus on investigating how nanobubbles mediate long-range interaction between neighboring solid substrates in the presence of the contact line pinning effect caused by surface heterogeneities. Using the constrained lattice density functional theory (LDFT), we prove that the nanobubbles, which take the form of vapor bridges here, are stabilized by the pinning effect if the separation between two substrates is less than a critical distance. The critical distance strongly depends on the chemical potential (i.e., the degree of saturation) and could become extremely long at a special chemical potential. Moreover, under the pinning effect, the substrate chemistry only determines the stability of the vapor bridges and the range of the capillary force, but has less influences on the magnitude of the capillary force, indicating that the substrate chemistry or the apparent contact angle for droplets or bubbles on the substrates is no longer a direct parameter to determine the magnitude of capillary force. A qualitative analysis for the two dimensional vapor bridges by considering the feedback mechanism can explain the results from the LDFT calculations.

  12. The research and development of the non-contact detection of the tubing internal thread with a line structured light

    NASA Astrophysics Data System (ADS)

    Hu, Yuanyuan; Xu, Yingying; Hao, Qun; Hu, Yao

    2013-12-01

    The tubing internal thread plays an irreplaceable role in the petroleum equipment. The unqualified tubing can directly lead to leakage, slippage and bring huge losses for oil industry. For the purpose of improving efficiency and precision of tubing internal thread detection, we develop a new non-contact tubing internal thread measurement system based on the laser triangulation principle. Firstly, considering that the tubing thread had a small diameter and relatively smooth surface, we built a set of optical system with a line structured light to irradiate the internal thread surface and obtain an image which contains the internal thread profile information through photoelectric sensor. Secondly, image processing techniques were used to do the edge detection of the internal thread from the obtained image. One key method was the sub-pixel technique which greatly improved the detection accuracy under the same hardware conditions. Finally, we restored the real internal thread contour information on the basis of laser triangulation method and calculated tubing thread parameters such as the pitch, taper and tooth type angle. In this system, the profile of several thread teeth can be obtained at the same time. Compared with other existing scanning methods using point light and stepper motor, this system greatly improves the detection efficiency. Experiment results indicate that this system can achieve the high precision and non-contact measurement of the tubing internal thread.

  13. SunLine Transit Agency Advanced Technology Fuel Cell Bus Evaluation: Fourth Results Report

    SciTech Connect

    Eudy, L.; Chandler, K.

    2013-01-01

    SunLine Transit Agency, which provides public transit services to the Coachella Valley area of California, has demonstrated hydrogen and fuel cell bus technologies for more than 10 years. In May 2010, SunLine began demonstrating the advanced technology (AT) fuel cell bus with a hybrid electric propulsion system, fuel cell power system, and lithium-based hybrid batteries. This report describes operations at SunLine for the AT fuel cell bus and five compressed natural gas buses. The U.S. Department of Energy's National Renewable Energy Laboratory (NREL) is working with SunLine to evaluate the bus in real-world service to document the results and help determine the progress toward technology readiness. NREL has previously published three reports documenting the operation of the fuel cell bus in service. This report provides a summary of the results with a focus on the bus operation from February 2012 through November 2012.

  14. Generalized potentials for a mean-field density functional theory of a three-phase contact line

    NASA Astrophysics Data System (ADS)

    Lin, Chang-You; Widom, Michael; Sekerka, Robert F.

    2013-07-01

    We investigate generalized potentials for a mean-field density functional theory of a three-phase contact line. Compared to the symmetrical potential introduced in our previous article [Phys. Rev. EPLEEE81539-375510.1103/PhysRevE.85.011120 85, 011120 (2012)], the three minima of these potentials form a small triangle located arbitrarily within the Gibbs triangle, which is more realistic for ternary fluid systems. We multiply linear functions that vanish at edges and vertices of the small triangle, yielding potentials in the form of quartic polynomials. We find that a subset of such potentials has simple analytic far-field solutions and is a linear transformation of our original potential. By scaling, we can relate their solutions to those of our original potential. For special cases, the lengths of the sides of the small triangle are proportional to the corresponding interfacial tensions. For the case of equal interfacial tensions, we calculate a line tension that is proportional to the area of the small triangle.

  15. Hysteresis during contact angles measurement.

    PubMed

    Diaz, M Elena; Fuentes, Javier; Cerro, Ramon L; Savage, Michael D

    2010-03-15

    A theory, based on the presence of an adsorbed film in the vicinity of the triple contact line, provides a molecular interpretation of intrinsic hysteresis during the measurement of static contact angles. Static contact angles are measured by placing a sessile drop on top of a flat solid surface. If the solid surface has not been previously in contact with a vapor phase saturated with the molecules of the liquid phase, the solid surface is free of adsorbed liquid molecules. In the absence of an adsorbed film, molecular forces configure an advancing contact angle larger than the static contact angle. After some time, due to an evaporation/adsorption process, the interface of the drop coexists with an adsorbed film of liquid molecules as part of the equilibrium configuration, denoted as the static contact angle. This equilibrium configuration is metastable because the droplet has a larger vapor pressure than the surrounding flat film. As the drop evaporates, the vapor/liquid interface contracts and the apparent contact line moves towards the center of the drop. During this process, the film left behind is thicker than the adsorbed film and molecular attraction results in a receding contact angle, smaller than the equilibrium contact angle.

  16. Technical Advance: Changes in neutrophil migration patterns upon contact with platelets in a microfluidic assay.

    PubMed

    Frydman, Galit H; Le, Anna; Ellett, Felix; Jorgensen, Julianne; Fox, James G; Tompkins, Ronald G; Irimia, Daniel

    2017-03-01

    Neutrophils are traditionally regarded as the "first responders" of the immune system. However, recent observations revealed that platelets often respond earlier to recruit and activate neutrophils within sites of injury and inflammation. Currently, platelet-neutrophil interactions are studied by intravital microscopy. Although such studies provide exceptional, physiologic in vivo data, they are also laborious and have low throughput. To accelerate platelet-neutrophil interaction studies, we have developed and optimized an ex vivo microfluidic platform with which the interactions between platelets and moving neutrophils are measured at single-cell level in precise conditions and with high throughput. With the use of this new assay, we have evaluated changes in neutrophil motility upon direct contact with platelets. Motility changes include longer distances traveled, frequent changes in direction, and faster neutrophil velocities compared with a standard motility response to chemoattractant fMLP. We also found that the neutrophil-platelet direct interactions are transient and mediated by CD62P-CD162 interactions, localized predominantly at the uropod of moving neutrophils. This "crawling," oscillatory neutrophil behavior upon platelet contact is consistent with previous in vivo studies and validates the use of this new test for the exploration of this interactive relationship.

  17. Second-line chemotherapy for patients with advanced gastric cancer: who may benefit?

    PubMed Central

    Catalano, V; Graziano, F; Santini, D; D'Emidio, S; Baldelli, A M; Rossi, D; Vincenzi, B; Giordani, P; Alessandroni, P; Testa, E; Tonini, G; Catalano, G

    2008-01-01

    No established second-line chemotherapy is available for patients with advanced gastric cancer failing to respond or progressing to first-line chemotherapy. However, 20–40% of these patients commonly receive second-line chemotherapy. We evaluated the influence of clinico-pathologic factors on the survival of 175 advanced gastric cancer patients, who received second-line chemotherapy at three oncology departments. Univariate and multivariate analyses found five factors which were independently associated with poor overall survival: performance status 2 (hazard ratio (HR), 1.79; 95% CI, 1.16–2.77; P=0.008), haemoglobin ⩽11.5 g l−1 (HR, 1.48; 95% CI, 1.06–2.05; P=0.019), CEA level >50 ng ml−1 (HR, 1.86; 95% CI, 1.21–2.88; P=0.004), the presence of greater than or equal to three metastatic sites of disease (HR, 1.72; 95% CI, 1.16–2.53; P=0.006), and time-to-progression under first-line chemotherapy ⩽6 months (HR, 1.97; 95% CI, 1.39–2.80; P<0.0001). A prognostic index was constructed dividing patients into low- (no risk factor), intermediate- (one to two risk factors), or high- (three to five risk factors) risk groups, and median survival times for each group were 12.7 months, 7.1 months, and 3.3 months, respectively (P<0.001). In the absence of data deriving from randomised trials, this analysis suggests that some easily available clinical factors may help to select patients with advanced gastric cancer who could derive more benefit from second-line chemotherapy. PMID:18971936

  18. SunLine Transit Agency Advanced Technology Fuel Cell Bus Evaluation: First Results Report

    SciTech Connect

    Eudy, L.; Chandler, K.

    2011-03-01

    This report describes operations at SunLine Transit Agency for their newest prototype fuel cell bus and five compressed natural gas (CNG) buses. In May 2010, SunLine began operating its sixth-generation hydrogen fueled bus, an Advanced Technology (AT) fuel cell bus that incorporates the latest design improvements to reduce weight and increase reliability and performance. The agency is collaborating with the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) to evaluate the bus in revenue service. This report provides the early data results and implementation experience of the AT fuel cell bus since it was placed in service.

  19. Studies of dynamic contact of ceramics and alloys for advanced heat engines. Final report

    SciTech Connect

    Gaydos, P.A.; Dufrane, K.F.

    1993-06-01

    Advanced materials and coatings for low heat rejection engines have been investigated for almost a decade. Much of the work has concentrated on the critical wear interface between the piston ring and cylinder liner. Simplified bench tests have identified families of coatings with high temperature wear performance that could meet or exceed that of conventional engine materials at today`s operating temperatures. More recently, engine manufacturers have begun to optimize material combinations and manufacturing processes so that the materials not only have promising friction and wear performance but are practical replacements for current materials from a materials and manufacturing cost standpoint. In this study, the advanced materials supplied by major diesel engine manufacturers were evaluated in an experimental apparatus that simulates many of the in-cylinder conditions of a low heat rejection diesel engine. Results include ring wear factors and average dynamic friction coefficients measured at intervals during the test. These results are compared with other advanced materials tested in the past as well as the baseline wear of current engines. Both fabricated specimens and sections of actual ring and cylinder liners were used in the testing. Observations and relative friction and wear performance of the individual materials are provided.

  20. Family of Advanced Beyond Line-of-Sight Terminals (FAB-T)

    DTIC Science & Technology

    2015-12-01

    Selected Acquisition Report (SAR) RCS: DD-A&T(Q&A)823-199 Family of Advanced Beyond Line-of-Sight Terminals (FAB-T) As of FY 2017 President’s...Program Office Estimate RDT&E - Research, Development, Test, and Evaluation SAR - Selected Acquisition Report SCP - Service Cost Position TBD - To Be...the B-2, B-52, and select RC-135 aircraft and will not provide satellite control or PNVC functionality. The initial installation and integration is a

  1. Advanced Learners' Comprehension of Discourse Connectives: The Role of L1 Transfer across On-Line and Off-Line Tasks

    ERIC Educational Resources Information Center

    Zufferey, Sandrine; Mak, Willem; Degand, Liesbeth; Sanders, Ted

    2015-01-01

    Discourse connectives are important indicators of textual coherence, and mastering them is an essential part of acquiring a language. In this article, we compare advanced learners' sensitivity to the meaning conveyed by connectives in an off-line grammaticality judgment task and an on-line reading experiment using eye-tracking. We also assess the…

  2. Size-dependent contact angle and the wetting and drying transition of a droplet adsorbed onto a spherical substrate: Line-tension effect.

    PubMed

    Iwamatsu, Masao

    2016-10-01

    The size-dependent contact angle and the drying and wetting morphological transition are studied with respect to the volume change for a spherical cap-shaped droplet placed on a spherical substrate. The line-tension effect is included using the rigorous formula for the Helmholtz free energy in the droplet capillary model. A morphological drying transition from a cap-shaped to a spherical droplet occurs when the substrate is hydrophobic and the droplet volume is small, similar to the transition predicted on a flat substrate. In addition, a morphological wetting transition from a cap-shaped to a wrapped spherical droplet occurs for a hydrophilic substrate and a large droplet volume. The contact angle depends on the droplet size: it decreases as the droplet volume increases when the line tension is positive, whereas it increases when the line tension is negative. The spherical droplets and wrapped droplets are stable when the line tension is positive and large.

  3. Drops down the hill: theoretical study of limiting contact angles and the hysteresis range on a tilted plate.

    PubMed

    Krasovitski, Boris; Marmur, Abraham

    2005-04-26

    The limiting inclination angle (slip angle), for which a two-dimensional water drop may be at equilibrium on a chemically heterogeneous surface, is exactly calculated for a variety of cases. The main conclusion is that, in the cases studied, the contact angles at the upper and lower contact line do not always simultaneously equal the receding and advancing contact angles, respectively. On a hydrophobic surface, the lowest contact angle (at the upper contact line) tends to be approximately equal to the receding contact angle, while the highest contact angle (at the lower contact line) may be much lower than the advancing contact angle. For hydrophilic surfaces, the opposite is true. These conclusions imply that the hysteresis range cannot in general be measured by analyzing the shape of a drop on an inclined plane. Also, the limiting inclination angle cannot in general be calculated from the classical equation based only on the advancing and receding contact angles.

  4. Current densities and total contact currents during forest clearing tasks under 400 kV power lines

    PubMed Central

    Kuisti, Harri; Elovaara, Jarmo

    2016-01-01

    The aim of the study was to analyze all values of electric currents from measured periods while performing tasks in forest clearing. The objective was also to choose and analyze measurement cases, where current measurements successfully lasted the entire work period (about 30 min). Two forestry workers volunteered to perform four forest clearing tasks under 400 kV power lines. The sampling frequency of the current measurements was 1 sample/s. The maximum values of the current densities were 1.0–1.2 mA/m2 (calculated internal EFs 5.0–12.0 mV/m), and the average values were 0.2–0.4 mA/m2. The highest contact current was 167.4 μA. All measured values during forest clearing tasks were lower than basic restrictions (0.1 V/m and 0.8 V/m) of the International Commission on Non‐Ionizing Radiation Protection. Bioelectromagnetics. 37:423–428, 2016. © 2016 The Authors. Bioelectromagnetics published by Wiley Periodicals, Inc. PMID:27192179

  5. Controllable Fabrication of Noniridescent Microshaped Photonic Crystal Assemblies by Dynamic Three-Phase Contact Line Behaviors on Superhydrophobic Substrates.

    PubMed

    Zhou, Jinming; Yang, Jing; Gu, Zhandong; Zhang, Guofu; Wei, Yu; Yao, Xi; Song, Yanlin; Jiang, Lei

    2015-10-14

    Enormous research efforts have been made to self-assemble monodisperse colloidal spheres into special microscopic shapes (e.g., superbeads, superballs, or doughnuts), due to their widespread applications in sensors, displays, separation processes, catalysis, etc. But realization of photonic crystal (PC) assemblies with both facile microshape control and a noniridescent property is still a tough task. Herein, we demonstrate the controllable fabrication of noniridescent microshaped PC assemblies by evaporation-induced self-assembly inside aqueous colloidal dispersion droplet templates on superhydrophobic substrates. The microshapes of the PC assemblies could be tuned from microbeads to microwells to microellipsoids by manipulating the dynamic behaviors of the three-phase contact line of the colloidal droplets during the evaporating process. Structure characterization shows that the PC assemblies are crack-free, consisting of an ordered periodic arrangement of colloidal spheres in the surface layers and amorphous inner layers. The incorporation of black Fe3O4 nanoparticles into the PC assembly lattice is demonstrated to endow the PC assemblies with enhanced noniridescent structural colors with wide-viewing angles and a superparamagnetic property. The crack-free noniridescent PC assemblies with controlled microshapes have promising applications in the fields of nontoxic, nonbleaching pigments and energy-efficient full-color display pixels, and their facile fabrication procedure may provide guidance for creating new types of substructured colloidal particles.

  6. Genomic Prediction of Seed Quality Traits Using Advanced Barley Breeding Lines

    PubMed Central

    Nielsen, Nanna Hellum; Jahoor, Ahmed; Jensen, Jens Due; Orabi, Jihad; Cericola, Fabio; Edriss, Vahid; Jensen, Just

    2016-01-01

    Genomic selection was recently introduced in plant breeding. The objective of this study was to develop genomic prediction for important seed quality parameters in spring barley. The aim was to predict breeding values without expensive phenotyping of large sets of lines. A total number of 309 advanced spring barley lines tested at two locations each with three replicates were phenotyped and each line was genotyped by Illumina iSelect 9Kbarley chip. The population originated from two different breeding sets, which were phenotyped in two different years. Phenotypic measurements considered were: seed size, protein content, protein yield, test weight and ergosterol content. A leave-one-out cross-validation strategy revealed high prediction accuracies ranging between 0.40 and 0.83. Prediction across breeding sets resulted in reduced accuracies compared to the leave-one-out strategy. Furthermore, predicting across full and half-sib-families resulted in reduced prediction accuracies. Additionally, predictions were performed using reduced marker sets and reduced training population sets. In conclusion, using less than 200 lines in the training set can result in low prediction accuracy, and the accuracy will then be highly dependent on the family structure of the selected training set. However, the results also indicate that relatively small training sets (200 lines) are sufficient for genomic prediction in commercial barley breeding. In addition, our results indicate a minimum marker set of 1,000 to decrease the risk of low prediction accuracy for some traits or some families. PMID:27783639

  7. Line profile measurement of advanced-FinFET features by reference metrology

    NASA Astrophysics Data System (ADS)

    Takamasu, Kiyoshi; Iwaki, Yuuki; Takahashi, Satoru; Kawada, Hiroki; Ikota, Masami; Yamaguchi, Atsuko; Lorusso, Gian F.; Horiguchi, Naoto

    2015-03-01

    A novel method of sub-nanometer uncertainty for the line profile measurement using TEM (Transmission Electron Microscope) images is proposed to calibrate CD-SEM (Critical Dimension Scanning Electron Microscope) line width measurement and to standardize line profile measurement through reference metrology. The proposed method has been validated for profile of Si line and photoresist features in our previous investigations. In this article, we apply the methodology to line profile measurements of advanced-FinFET (Fin-shaped Field-Effect Transistor) features. The FinFET features are sliced as thin specimens of 100 nm thickness by FIB (Focused Ion Beam) micro sampling system. Cross-sectional images of the specimens are obtained then by TEM. The profiles of fin, hardmask and dummy gate of FinFET features are evaluated using TEM images. The width of fin, the length of hardmask, and the length of dummy gate of FinFET features are measured and compared to CD-SEM measurement. The TEM results will be used to implement CD-SEM and CD-AFM reference metrology.

  8. Process Knowledge Summary Report for Advanced Test Reactor Complex Contact-Handled Transuranic Waste Drum TRA010029

    SciTech Connect

    B. R. Adams; R. P. Grant; P. R. Smith; J. L. Weisgerber

    2013-09-01

    This Process Knowledge Summary Report summarizes information collected to satisfy the transportation and waste acceptance requirements for the transfer of one drum containing contact-handled transuranic (TRU) actinide standards generated by the Idaho National Laboratory at the Advanced Test Reactor (ATR) Complex to the Advanced Mixed Waste Treatment Project (AMWTP) for storage and subsequent shipment to the Waste Isolation Pilot Plant for final disposal. The drum (i.e., Integrated Waste Tracking System Bar Code Number TRA010029) is currently stored at the Materials and Fuels Complex. The information collected includes documentation that addresses the requirements for AMWTP and applicable sections of their Resource Conservation and Recovery Act permits for receipt and disposal of this TRU waste generated from ATR. This Process Knowledge Summary Report includes information regarding, but not limited to, the generation process, the physical form, radiological characteristics, and chemical contaminants of the TRU waste, prohibited items, and packaging configuration. This report, along with the referenced supporting documents, will create a defensible and auditable record for this TRU waste originating from ATR.

  9. Base Stock Policy in a Join-Type Production Line with Advanced Demand Information

    NASA Astrophysics Data System (ADS)

    Hiraiwa, Mikihiko; Tsubouchi, Satoshi; Nakade, Koichi

    Production control such as the base stock policy, the kanban policy and the constant work-in-process policy in a serial production line has been studied by many researchers. Production lines, however, usually have fork-type, join-type or network-type figures. In addition, in most previous studies on production control, a finished product is required at the same time as arrival of demand at the system. Demand information is, however, informed before due date in practice. In this paper a join-type (assembly) production line under base stock control with advanced demand information in discrete time is analyzed. The recursive equations for the work-in-process are derived. The heuristic algorithm for finding appropriate base stock levels of all machines at short time is proposed and the effect of advanced demand information is examined by simulation with the proposed algorithm. It is shown that the inventory cost can decreases with little backlogs by using the appropriate amount of demand information and setting appropriate base stock levels.

  10. SunLine Transit Agency Advanced Technology Fuel Cell Bus Evaluation: Third Results Reports

    SciTech Connect

    Eudy, L.; Chandler, K.

    2012-05-01

    This report describes operations at SunLine Transit Agency for their newest prototype fuel cell bus and five compressed natural gas (CNG) buses. In May 2010, SunLine began operating its sixth-generation hydrogen fueled bus, an Advanced Technology (AT) fuel cell bus that incorporates the latest design improvements to reduce weight and increase reliability and performance. The agency is collaborating with the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) to evaluate the bus in revenue service. NREL has previously published two reports documenting the operation of the fuel cell bus in service. This report provides a summary of the results with a focus on the bus operation from July 2011 through January 2012.

  11. The Advanced Light Source U8 beam line, 20--300 eV

    SciTech Connect

    Heimann, P.; Warwick, T.; Howells, M.; McKinney, W.; Digennaro, D.; Gee, B.; Yee, D.; Kincaid, B.

    1991-10-01

    The U8 is a beam line under construction at the Advanced Light Source (ALS). The beam line will be described along with calculations of its performance and its current status. An 8 cm period undulator is followed by two spherical collecting mirrors, an entrance slit, spherical gratings having a 15{degree} deviation angle, a moveable exit slit, and refocusing and branching mirrors. Internal water cooling is provided to the metal M1 and M2 mirrors as well as to the gratings. Calculations have been made of both the flux output and the resolution over its photon energy range of 20--300 eV. The design goal was to achieve high intensity, 10{sup 12} photons/sec, at a high resolving power of 10,000. The U8 Participating Research Team (PRT) is planning experiments involving the photoelectron spectroscopy of gaseous atoms and molecules, the spectroscopy of ions and actinide spectroscopy.

  12. SunLine Transit Agency Advanced Technology Fuel Cell Bus Evaluation: Second Results Report and Appendices

    SciTech Connect

    Eudy, L.; Chandler, K.

    2011-10-01

    This report describes operations at SunLine Transit Agency for their newest prototype fuel cell bus and five compressed natural gas (CNG) buses. In May 2010, SunLine began operating its sixth-generation hydrogen fueled bus, an Advanced Technology (AT) fuel cell bus that incorporates the latest design improvements to reduce weight and increase reliability and performance. The agency is collaborating with the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) to evaluate the bus in revenue service. This is the second results report for the AT fuel cell bus since it was placed in service, and it focuses on the newest data analysis and lessons learned since the previous report. The appendices, referenced in the main report, provide the full background for the evaluation. They will be updated as new information is collected but will contain the original background material from the first report.

  13. Synchrotron X-Ray Microdiffraction Studies of Electromigration in Interconnect lines at the Advanced Light Source

    SciTech Connect

    Tamura, Nobumichi; Chen, Kai; Kunz, Martin

    2009-12-01

    Synchrotron polychromatic X-ray microdiffraction is a particularly suitable technique to study in situ the effect of electromigration in metal interconnects as add spatial resolution to grain orientation and strain sensitivity. This technique has been extensively used at the Advanced Light Source to monitor changes in aluminum and copper interconnect test structures while high-density current is passed into them during accelerated tests at elevated temperature. One of the principal findings is the observation of electromigration-induced plasticity in the metal lines that appear during the very early stages of electromigration. In some of the lines, high density of geometrically necessary dislocation are formed leading to additional diffusion paths causing an enhancement of electromigration effect at test temperature.

  14. The use of safeguards data for process monitoring in the Advanced Test Line for Actinide Separations

    SciTech Connect

    Barnes, J.W.; Yarbro, S.L.

    1987-01-01

    Los Alamos is constructing an integrated process monitoring/materials control and accounting (PM/MC and A) system in the Advanced Testing Line for Actinide Separations (ATLAS) at the Los Alamos Plutonium Facility. The ATLAS will test and demonstrate new methods for aqueous processing of plutonium. The ATLAS will also develop, test, and demonstrate the concepts for integrated process monitoring/materials control and accounting. We describe how this integrated PM/MC and A system will function and provide benefits to both process research and materials accounting personnel.

  15. Update on taxanes in the first-line treatment of advanced non-small-cell lung cancer.

    PubMed

    Socinski, M A

    2014-10-01

    Based on demonstrated favourable risk-benefit profiles, taxanes remain a key component in the first-line standard of care for advanced non-small-cell lung cancer (nsclc) and nsclc subtypes. In 2012, a novel taxane, nab-paclitaxel (Abraxane: Celgene Corporation, Summit, NJ, U.S.A.), was approved, in combination with carboplatin, for the first-line treatment of locally advanced or meta-static nsclc. The approval was granted because of demonstrated improved antitumour activity and tolerability compared with solvent-based paclitaxel-carboplatin in a phase iii trial. This review focuses on the evolution of first-line taxane therapy for advanced nsclc and the new options and advances in taxane therapy that might address unmet needs in advanced nsclc.

  16. Analysis of line integrated electron density using plasma position data on Korea Superconducting Tokamak Advanced Researcha)

    NASA Astrophysics Data System (ADS)

    Nam, Y. U.; Chung, J.

    2010-10-01

    A 280 GHz single-channel horizontal millimeter-wave interferometer system has been installed for plasma electron density measurements on the Korea Superconducting Tokamak Advanced Research (KSTAR) device. This system has a triangular beam path that does not pass through the plasma axis due to geometrical constraints in the superconducting tokamak. The term line density on KSTAR has a different meaning from the line density of other tokamaks. To estimate the peak density and the mean density from the measured line density, information on the position of the plasma is needed. The information has been calculated from tangentially viewed visible images using the toroidal symmetry of the plasma. Interface definition language routines have been developed for this purpose. The calculated plasma position data correspond well to calculation results from magnetic analysis. With the position data and an estimated plasma profile, the peak density and the mean density have been obtained from the line density. From these results, changes of plasma density themselves can be separated from effects of the plasma movements, so they can give valuable information on the plasma status.

  17. A phase II study of carboplatin and vinorelbine as second-line treatment for advanced breast cancer.

    PubMed Central

    Iaffaioli, R. V.; Tortoriello, A.; Facchini, G.; Santangelo, M.; De Sena, G.; Gesue, G.; Bucci, L.; Scaramellino, G.; Anastasio, E.; Finizio, A.

    1995-01-01

    Forty-one patients with advanced breast cancer were given carboplatin and vinorelbine as second-line therapy. Overall objective response rate was 46% (95% confidence interval 26-56%). Myelotoxicity was the most frequently observed toxic effect; grade III-IV leucopenia occurred in 46% of the patients. Our regimen is active as second-line chemotherapy for advanced breast cancer and warrants further evaluation. PMID:7577478

  18. Fluid structure in the immediate vicinity of an equilibrium three-phase contact line and assessment of disjoining pressure models using density functional theory

    NASA Astrophysics Data System (ADS)

    Nold, Andreas; Sibley, David N.; Goddard, Benjamin D.; Kalliadasis, Serafim

    2014-07-01

    We examine the nanoscale behavior of an equilibrium three-phase contact line in the presence of long-ranged intermolecular forces by employing a statistical mechanics of fluids approach, namely, density functional theory (DFT) together with fundamental measure theory (FMT). This enables us to evaluate the predictive quality of effective Hamiltonian models in the vicinity of the contact line. In particular, we compare the results for mean field effective Hamiltonians with disjoining pressures defined through (i) the adsorption isotherm for a planar liquid film, and (ii) the normal force balance at the contact line. We find that the height profile obtained using (i) shows good agreement with the adsorption film thickness of the DFT-FMT equilibrium density profile in terms of maximal curvature and the behavior at large film heights. In contrast, we observe that while the height profile obtained by using (ii) satisfies basic sum rules, it shows little agreement with the adsorption film thickness of the DFT results. The results are verified for contact angles of 20°, 40°, and 60°.

  19. Radiological study on newly developed composite corn advance lines in Malaysia

    NASA Astrophysics Data System (ADS)

    Adekunle Olatunji, Michael; Bemigho Uwatse, Onosohwo; Uddin Khandaker, Mayeen; Amin, Y. M.; Faruq, G.

    2014-12-01

    Owing to population growth, there has been high demand for food across the world, and hence, different agricultural activities such as use of phosphate fertilizers, recycling of organic matters, etc, have been deployed to increase crop yields. In Malaysia, a total of nine composite corn advance lines have been developed at the Institute of Biological Sciences, University of Malaya and are being grown under different conditions with a bid to meet the average daily human need for energy and fiber intake. To this end, the knowledge of radioactivity levels in these corn advance lines are of paramount importance for the estimation of possible radiological hazards due to its consumption. Hence, the radioactivity concentrations of 226Ra, 228Ra and 40K in the corn have been determined using HPGe γ-ray spectrometry. The activity concentrations in the corn ranged from 0.05 to 19.18 Bq kg-1 for 226Ra, from 0.10 to 3.22 Bq kg-1 for 228Ra and from 26.4 to 129 Bq kg-1 for 40K. In order to ascertain the radiological safety of the population regarding maize consumption, the daily intakes of these radionuclides as well as the annual effective dose were estimated. The total effective dose obtained due to the ingestion of radionuclides via maize consumption is 15.39 μSv y-1, which is less than the international recommendations.

  20. High resolution genotyping by restriction enzyme-phased sequencing of advanced backcross lines of rice exhibiting differential cold stress recovery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Advanced backcross rice lines MIb 4853-9 and 6885-2 harbor major seedling cold tolerance QTL qCTS4 and qCTS12 from the temperate japonica M202 in the genetic background of the indica IR50. Previous studies have shown that these lines exhibit the same tolerance, based on visual ratings, under constan...

  1. Beyond first-line chemotherapy for advanced pancreatic cancer: An expanding array of therapeutic options?

    PubMed Central

    Walker, Evan J; Ko, Andrew H

    2014-01-01

    While an increasing number of therapeutic options are now available for the first-line treatment of locally advanced or metastatic pancreatic cancer, the optimal choice for treatment in the second-line setting and beyond is less well defined. A variety of cytotoxic agents, either alone or in combination, have been evaluated, although primarily in the context of small single-arm or retrospective studies. Most regimens have been associated with median progression-free survival rates in the range of 2-4 mo and overall survival rates between 4-8 mo, highlighting the very poor prognosis of patients who are candidates for such treatment. Targeted therapies studied in this chemotherapy-refractory setting, meanwhile, have produced even worse efficacy results. In the current article, we review the clinical evidence for treatment of refractory disease, primarily in patients who have progressed on front-line gemcitabine-based chemotherapy. In the process, we highlight the limitations of the available data to date as well as some of the challenges in designing appropriate clinical trials in this salvage setting, including how to select an appropriate control arm given the absence of a well-established reference standard, and the importance of incorporating predictive biomarkers and quality of life measures whenever possible into study design. PMID:24605022

  2. Surface-Engineered Contact Lens as an Advanced Theranostic Platform for Modulation and Detection of Viral Infection.

    PubMed

    Mak, Wing Cheung; Cheung, Kwan Yee; Orban, Jenny; Lee, Chyan-Jang; Turner, Anthony P F; Griffith, May

    2015-11-18

    We have demonstrated an entirely new concept of a wearable theranostic device in the form of a contact lens (theranostic lens) with a dual-functional hybrid surface to modulate and detect a pathogenic attack, using a the corneal HSV serotype-1 (HSV-1) model. The theranostic lenses were constructed using a facile layer-by-layer surface engineering technique, keeping the theranostic lenses with good surface wettability, optically transparency, and nontoxic toward human corneal epithelial cells. The theranostic lenses were used to capture and concentrate inflammatory cytokines such as interleukin-1α (IL-1α), which is upregulated during HSV-1 reactivation, for sensitive, noninvasive diagnostics. The theranostic lens also incorporated an antiviral coating to serve as a first line of defense to protect patients against disease. Our strategy tackles major problems in tear diagnostics that are mainly associated with the sampling of a relatively small volume of fluid and the low concentration of biomarkers. The theranostic lenses show effective anti-HSV-1 activity and good analytical performance for the detection of IL-1α, with a limit of detection of 1.43 pg mL(-1) and a wide linear range covering the clinically relevant region. This work offers a new paradigm for "wearable" noninvasive healthcare devices combining "diagnosis" and "protection" against disease, while supporting patient compliance. We believe that this approach holds immense promise as a next-generation point-of-care and decentralized diagnostic/theranostic platform for a range of biomarkers.

  3. The HEWAC pilot line experience

    NASA Technical Reports Server (NTRS)

    Gillanders, M.; Opjorden, R.

    1980-01-01

    Advanced silicon solar cells with both electrical contacts on the back side of the cell are described. These high efficiency wrap around contact solar cells (HEWACS) utilize a screen printed dielectric insulation layer to isolate the 'n' and 'p' contacts from each other. Development of a device exhibiting high AMO conversion efficiencies is addressed along with the processing of such cells to a point where cell fabrication can be carried out by production personnel under operating production line conditions.

  4. Multivariate prognostic factors analysis for second-line chemotherapy in advanced biliary tract cancer

    PubMed Central

    Fornaro, L; Cereda, S; Aprile, G; Di Girolamo, S; Santini, D; Silvestris, N; Lonardi, S; Leone, F; Milella, M; Vivaldi, C; Belli, C; Bergamo, F; Lutrino, S E; Filippi, R; Russano, M; Vaccaro, V; Brunetti, A E; Rotella, V; Falcone, A; Barbera, M A; Corbelli, J; Fasola, G; Aglietta, M; Zagonel, V; Reni, M; Vasile, E; Brandi, G

    2014-01-01

    Background: The role of second-line chemotherapy (CT) is not established in advanced biliary tract cancer (aBTC). We investigated the outcome of aBTC patients treated with second-line CT and devised a prognostic model. Methods: Baseline clinical and laboratory data of 300 consecutive aBTC patients were collected and association with overall survival (OS) was investigated by multivariable Cox models. Results: The following parameters resulted independently associated with longer OS: Eastern Cooperative Oncology Group performance status of 0 (P<0.001; hazard ratio (HR), 0.348; 95% confidence interval (CI) 0.215–0.562), CA19.9 lower than median (P=0.013; HR, 0.574; 95% CI 0.370–0.891), progression-free survival after first-line CT ⩾6 months (P=0.027; HR, 0.633; 95% CI 0.422–0.949) and previous surgery on primary tumour (P=0.027; HR, 0.609; 95% CI 0.392–0.945). We grouped the 249 patients with complete data available into three categories according to the number of fulfilled risk factors: median OS times for good-risk (zero to one factors), intermediate-risk (two factors) and poor-risk (three to four factors) groups were 13.1, 6.6 and 3.7 months, respectively (P<0.001). Conclusions: Easily available clinical and laboratory factors predict prognosis of aBTC patients undergoing second-line CT. This model allows individual patient-risk stratification and may help in treatment decision and trial design. PMID:24714745

  5. Magnetic fields dispersed by high-voltage power lines: an advanced evaluation method based on 3-D models of electrical lines and the territory.

    PubMed

    Andreuccetti, D; Zoppetti, N

    2004-01-01

    An advanced numerical evaluation tool is proposed for calculating the magnetic flux density dispersed by high-voltage power lines. When compared to existing software packages based on the application of standardized methods, this tool turned out to be particularly suitable for making accurate evaluations on vast portions of the territory, especially when the contribution of numerous aerial and/or underground lines must be taken into account. The aspects of the tool of greatest interest are (1) the interaction with an electronic archive of power lines, from which all the information necessary for the calculation is obtained; (2) the use of three-dimensional models of both the power lines and the territory crossed by these; (3) the direct interfacing with electronic cartography; and finally (4) the use of a representation procedure for the results that is based on contour maps. The tool had proven to be very useful especially for Environmental Impact Assessment procedures relative to new power lines.

  6. Spectroscopic On-Line Monitoring of Cu/W Contacts Erosion in HVCBs Using Optical-Fibre Based Sensor and Chromatic Methodology

    PubMed Central

    Wang, Zhixiang; Jones, Gordon R.; Spencer, Joseph W.; Wang, Xiaohua; Rong, Mingzhe

    2017-01-01

    Contact erosion is one of the most crucial factors affecting the electrical service lifetime of high-voltage circuit breakers (HVCBs). On-line monitoring the contacts’ erosion degree is increasingly in demand for the sake of condition based maintenance to guarantee the functional operation of HVCBs. A spectroscopic monitoring system has been designed based upon a commercial 245 kV/40 kA SF6 live tank circuit breaker with copper–tungsten (28 wt % and 72 wt %) arcing contacts at atmospheric SF6 pressure. Three optical-fibre based sensors are used to capture the time-resolved spectra of arcs. A novel approach using chromatic methods to process the time-resolved spectral signal has been proposed. The processed chromatic parameters have been interpreted to show that the time variation of spectral emission from the contact material and quenching gas are closely correlated to the mass loss and surface degradation of the plug arcing contact. The feasibility of applying this method to online monitoring of contact erosion is indicated. PMID:28272295

  7. Modeling contact angle hysteresis of a liquid droplet sitting on a cosine wave-like pattern surface.

    PubMed

    Promraksa, Arwut; Chen, Li-Jen

    2012-10-15

    A liquid droplet sitting on a hydrophobic surface with a cosine wave-like square-array pattern in the Wenzel state is simulated by using the Surface Evolver to determine the contact angle. For a fixed drop volume, multiple metastable states are obtained at two different surface roughnesses. Unusual and non-circular shape of the three-phase contact line of a liquid droplet sitting on the model surface is observed due to corrugation and distortion of the contact line by structure of the roughness. The contact angle varies along the contact line for each metastable state. The maximum and minimum contact angles among the multiple metastable states at a fixed viewing angle correspond to the advancing and the receding contact angles, respectively. It is interesting to observe that the advancing/receding contact angles (and contact angle hysteresis) are a function of viewing angle. In addition, the receding (or advancing) contact angles at different viewing angles are determined at different metastable states. The contact angle of minimum energy among the multiple metastable states is defined as the most stable (equilibrium) contact angle. The Wenzel model is not able to describe the contact angle along the three-phase contact line. The contact angle hysteresis at different drop volumes is determined. The number of the metastable states increases with increasing drop volume. Drop volume effect on the contact angles is also discussed.

  8. Development Status of the Advanced Life Support On-Line Project Information System

    NASA Technical Reports Server (NTRS)

    Levri, Julie A.; Hogan, John A.; Cavazzoni, Jim; Brodbeck, Christina; Morrow, Rich; Ho, Michael; Kaehms, Bob; Whitaker, Dawn R.

    2005-01-01

    The Advanced Life Support Program has recently accelerated an effort to develop an On-line Project Information System (OPIS) for research project and technology development data centralization and sharing. The core functionality of OPIS will launch in October of 2005. This paper presents the current OPIS development status. OPIS core functionality involves a Web-based annual solicitation of project and technology data directly from ALS Principal Investigators (PIS) through customized data collection forms. Data provided by PIs will be reviewed by a Technical Task Monitor (TTM) before posting the information to OPIS for ALS Community viewing via the Web. The data will be stored in an object-oriented relational database (created in MySQL(R)) located on a secure server at NASA ARC. Upon launch, OPIS can be utilized by Managers to identify research and technology development gaps and to assess task performance. Analysts can employ OPIS to obtain.

  9. Effect of tree line advance on carbon storage in NW Alaska

    USGS Publications Warehouse

    Wilmking, M.; Harden, J.; Tape, K.

    2006-01-01

    We investigated the size, distribution, and temporal dynamics of ecosystem carbon (C) pools in an area of recent tree line advance, northwest Alaska. Repeat aerial photographs show forest cover increased ???10% in our study area since 1949. We sampled C pools of four principal ecosystem types, tussock tundra, shrub tundra, woodland, and forest, all located on a 600-800 year old river terrace. Significant differences between ecosystem C pools, both above ground and below ground existed. Tundra sites store >22.2 kg C/m2, shrub tundra sites and woodland sites store 9.7 kg C/m2 and 14.3 kg C/m2, respectively, and forest sites store 14.4 kg C/m2. Landscape variation of total ecosystem C was primarily due to organic soil C and was secondarily due to C stored in trees. Soil C/N profiles of shrub tundra sites and woodland sites showed similarities with forest site soils at surface and tundra site soils at depth. We hypothesize that tundra systems transformed to forest systems in this area under a progression of permafrost degradation and enhanced drainage. On the basis of C pool estimates for the different ecosystem types, conversion of tundra sites to forest may have resulted in a net loss of > 7.8 kg C/m2, since aboveground C gains were more than offset by belowground C losses to decomposition in the tundra sites. Tree line advance therefore might not increase C storage in high-latitude ecosystems and thus might not, as previously suggested, act as a negative feedback to warming. Key to this hypothesis and to its projection to future climate response is the fate of soil carbon upon warming and permafrost drainage. Copyright 2006 by the American Geophysical Union.

  10. Field Trial of LANL On-Line Advanced Enrichment Monitor for UF6 GCEP

    SciTech Connect

    Ianakiev, Kiril D.; Lombardi, Marcie; MacArthur, Duncan W.; Parker, Robert F.; Smith, Morag K.; Keller, Clifford; Friend, Peter; Dunford, Andrew

    2012-07-13

    The outline of this presentation is: (1) Technology basis of on-line enrichment monitoring; (2) Timescale of trial; (3) Description of installed equipment; (4) Photographs; (5) Results; (6) Possible further development; and (7) Conclusions. Summary of the good things about the Advanced Enrichment Monitor (AEM) performance is: (1) High accuracy - normally better than 1% relative, (2) Active system as accurate as passive system, (3) Fast and accurate detection of enrichment changes, (4) Physics is well understood, (5) Elegant method for capturing pressure signal, and (6) Data capture is automatic, low cost and fast. A couple of negative things are: (1) Some jumps in measured passive enrichment - of around +2% relative (due to clock errors?); and (2) Data handling and evaluation is off-line, expensive and very slow. Conclusions are: (1) LANL AEM is being tested on E23 plant at Capenhurst; (2) The trial is going very well; (3) AEM could detect production of HEU at potentially much lower cost than existing CEMO; (4) AEM can measure {sup 235}U assay accurately; (5) Active system using X-Ray source would avoid need for pressure measurement; (6) Substantial work lies ahead to go from current prototype to a production instrument.

  11. Synchrotron X-Ray Microdiffraction Studies of Electromigration in Interconnect lines at the Advanced Light Source

    SciTech Connect

    Tamura, Nobumichi; Chen, Kai; Kunz, Martin

    2009-05-01

    Synchrotron polychromatic X-ray microdiffraction is a particularly suitable technique to study in situ the effect of electromigration in metal interconnects as add spatial resolution to grain orientation and strain sensitivity. This technique has been extensively used at the Advanced Light Source to monitor changes in aluminum and copper interconnect test structures while high-density current is passed into them during accelerated tests at elevated temperature. One of the principal findings is the observation of electromigration-induced plasticity in the metal lines that appear during the very early stages of electromigration. In some of the lines, high density of geometrically necessary dislocation are formed leading to additional diffusion paths causing an enhancement of electromigration effect at test temperature. This paper presents an overview of the principal results obtained from X-ray microdiffraction studies of electromigration effects on aluminum and copper interconnects at the ALS throughout continuous efforts that spanned over a decade (1998-2008) from approximately 40 weeks of combined beamtime.

  12. Shrub line advance in Arctic and alpine tundra of the Yukon Territory

    NASA Astrophysics Data System (ADS)

    Myers-Smith, I. H.; Hik, D.

    2010-12-01

    Growing evidence indicates an expansion of canopy-forming woody shrubs up mountain slopes and northward into Arctic tundra. The correlation between warming and greening has been used to link climate change with shrub expansion; however, the exact mechanisms driving observed increases in canopy-forming shrubs are probably more complex. Shrub expansion that results in a change in canopy cover may modify the ecology of tundra ecosystems by changing understory plant composition, soil thermal dynamics, surface albedo, nutrient turnover times and carbon storage. We surveyed the abundance of all tundra willow species (Salix spp.) growing at three sites in the Yukon Territory: the mountains of the Kluane Region, the Richardson Mountains, and on Qikiqtaruk - Herschel Island in the Beaufort Sea. At the two mountainous sites, we collected sections from the largest stem of willow shrubs at shrub line (the maximum elevation at which canopy-forming shrubs grow) and below shrub line (at approximately 50% shrub cover) in a total of 16 valleys. At the coastal site we collected samples from each of the 4 vegetation types: the alluvial fan, ridges, tussock tundra and disturbed terrain. Shrub stems were thin-sectioned using a microtome, photographed with a microscope and ring widths were measured from the digital images. We compared age distributions of willow individuals at and below shrub line and found younger populations at higher elevations, particularly on warm, south-facing aspects. Younger willows at shrub line and a lack of significant mortality in the field surveys indicate that shrubs have advanced up slope at the mountainous sites. Photographic and long-term plot data indicate increases in cover and height of willow shrub patches at the coastal site. We compared growth rings to regional weather data, and found positive correlations between annual growth and summer temperatures. Our results indicate that willows grew most in years with a warm June and July. This evidence of

  13. Development Approach of the Advanced Life Support On-line Project Information System

    NASA Technical Reports Server (NTRS)

    Levri, Julie A.; Hogan, John A.; Morrow, Rich; Ho, Michael C.; Kaehms, Bob; Cavazzoni, Jim; Brodbeck, Christina A.; Whitaker, Dawn R.

    2005-01-01

    The Advanced Life Support (ALS) Program has recently accelerated an effort to develop an On-line Project Information System (OPIS) for research project and technology development data centralization and sharing. There has been significant advancement in the On-line Project Information System (OPIS) over the past year (Hogan et al, 2004). This paper presents the resultant OPIS development approach. OPIS is being built as an application framework consisting of an uderlying Linux/Apache/MySQL/PHP (LAMP) stack, and supporting class libraries that provides database abstraction and automatic code generation, simplifying the ongoing development and maintenance process. Such a development approach allows for quick adaptation to serve multiple Programs, although initial deployment is for an ALS module. OPIS core functionality will involve a Web-based annual solicitation of project and technology data directly from ALS Principal Investigators (PIs) through customized data collection forms. Data provided by PIs will be reviewed by a Technical Task Monitor (TTM) before posting the information to OPIS for ALS Community viewing via the Web. Such Annual Reports will be permanent, citable references within OPIS. OPlS core functionality will also include Project Home Sites, which will allow PIS to provide updated technology information to the Community in between Annual Report updates. All data will be stored in an object-oriented relational database, created in MySQL(Reistered Trademark) and located on a secure server at NASA Ames Research Center (ARC). Upon launch, OPlS can be utilized by Managers to identify research and technology development (R&TD) gaps and to assess task performance. Analysts can employ OPlS to obtain the current, comprehensive, accurate information about advanced technologies that is required to perform trade studies of various life support system options. ALS researchers and technology developers can use OPlS to achieve an improved understanding of the NASA

  14. Development of an advanced multimode automatic ultrasonic texture measurement system for laboratory and production line application.

    PubMed

    Potter, M D G; Dixon, S; Morrison, J P; Suliamann, A S

    2006-12-22

    We present work on the development of an ultrasonic texture measurement system for sheet metals using non-contact transducers, suitable for use both in the laboratory and on the production line. Variation of the velocity of the zero-order symmetric (S0) Lamb wave is used to determine the crystallographic texture of polycrystalline metal sheets ranging in thickness from 0.1 to 3 mm. This system features improvements on previous state-of-the-art ultrasonic technology in that it probes velocity over a continuous range of angles using only two electromagnetic acoustic transducers (EMATs). This is demonstrated to offer a significant improvement in accuracy and allows the detection and investigation of asymmetric anisotropies in the sheets. Another advantage of the system is its potential for combining several different measurements using a single pair of transducers. The capability is demonstrated for through-thickness shear wave measurements as well as the zero-order symmetric Lamb wave measurements which are the primary means of determining the texture. The change between generating Lamb and through-thickness bulk waves can be made entirely by changing the electrical circuit connected to the EMATs without modifying the transducer assembly in any way. Measurement of all of the above waves can provide information on the sheet thickness and other physical properties of the sheet in addition to texture. Certain texture parameters can be calculated from both Lamb and shear wave velocities, allowing self-calibration of the system.

  15. Advanced in-line metrology strategy for self-aligned quadruple patterning

    NASA Astrophysics Data System (ADS)

    Chao, Robin; Breton, Mary; L'herron, Benoit; Mendoza, Brock; Muthinti, Raja; Nelson, Florence; De La Pena, Abraham; Le, Fee li; Miller, Eric; Sieg, Stuart; Demarest, James; Gin, Peter; Wormington, Matthew; Cepler, Aron; Bozdog, Cornel; Sendelbach, Matthew; Wolfling, Shay; Cardinal, Tom; Kanakasabapathy, Sivananda; Gaudiello, John; Felix, Nelson

    2016-03-01

    Self-Aligned Quadruple Patterning (SAQP) is a promising technique extending the 193-nm lithography to manufacture structures that are 20nm half pitch or smaller. This process adopts multiple sidewall spacer image transfers to split a rather relaxed design into a quarter of its original pitch. Due to the number of multiple process steps required for the pitch splitting in SAQP, the process error propagates through each deposition and etch, and accumulates at the final step into structure variations, such as pitch walk and poor critical dimension uniformity (CDU). They can further affect the downstream processes and lower the yield. The impact of this error propagation becomes significant for advanced technology nodes when the process specifications of device design CD requirements are at nanometer scale. Therefore, semiconductor manufacturing demands strict in-line process control to ensure a high process yield and improved performance, which must rely on precise measurements to enable corrective actions and quick decision making for process development. This work aims to provide a comprehensive metrology solution for SAQP. During SAQP process development, the challenges in conventional in-line metrology techniques start to surface. For instance, critical-dimension scanning electron microscopy (CDSEM) is commonly the first choice for CD and pitch variation control. However, it is found that the high aspect ratio at mandrel level processes and the trench variations after etch prevent the tool from extracting the true bottom edges of the structure in order to report the position shift. On the other hand, while the complex shape and variations can be captured with scatterometry, or optical CD (OCD), the asymmetric features, such as pitch walk, show low sensitivity with strong correlations in scatterometry. X-ray diffraction (XRD) is known to provide useful direct measurements of the pitch walk in crystalline arrays, yet the data analysis is influenced by the incoming

  16. Collagen gel droplet-embedded culture drug sensitivity testing in squamous cell carcinoma cell lines derived from human oral cancers: Optimal contact concentrations of cisplatin and fluorouracil

    PubMed Central

    Sakuma, Kaname; Tanaka, Akira; Mataga, Izumi

    2016-01-01

    The collagen gel droplet-embedded culture drug sensitivity test (CD-DST) is an anticancer drug sensitivity test that uses a method of three-dimensional culture of extremely small samples, and it is suited to primary cultures of human cancer cells. It is a useful method for oral squamous cell carcinoma (OSCC), in which the cancer tissues available for testing are limited. However, since the optimal contact concentrations of anticancer drugs have yet to be established in OSCC, CD-DST for detecting drug sensitivities of OSCC is currently performed by applying the optimal contact concentrations for stomach cancer. In the present study, squamous carcinoma cell lines from human oral cancer were used to investigate the optimal contact concentrations of cisplatin (CDDP) and fluorouracil (5-FU) during CD-DST for OSCC. CD-DST was performed in 7 squamous cell carcinoma cell lines derived from human oral cancers (Ca9-22, HSC-3, HSC-4, HO-1-N-1, KON, OSC-19 and SAS) using CDDP (0.15, 0.3, 1.25, 2.5, 5.0 and 10.0 µg/ml) and 5-FU (0.4, 0.9, 1.8, 3.8, 7.5, 15.0 and 30.0 µg/ml), and the optimal contact concentrations were calculated from the clinical response rate of OSCC to single-drug treatment and the in vitro efficacy rate curve. The optimal concentrations were 0.5 µg/ml for CDDP and 0.7 µg/ml for 5-FU. The antitumor efficacy of CDDP at this optimal contact concentration in CD-DST was compared to the antitumor efficacy in the nude mouse method. The T/C values, which were calculated as the ratio of the colony volume of the treatment group and the colony volume of the control group, at the optimal contact concentration of CDDP and of the nude mouse method were almost in agreement (P<0.05) and predicted clinical efficacy, indicating that the calculated optimal contact concentration is valid. Therefore, chemotherapy for OSCC based on anticancer drug sensitivity tests offers patients a greater freedom of choice and is likely to assume a greater importance in the selection of

  17. Advanced manual lensometry: a self-learning guide for evaluating multifocal and specialty lenses, progressive lenses, prisms, and rigid contact lenses.

    PubMed

    Garber, N

    2000-01-01

    Advanced manual lensometry techniques are required when automated lensometry may not be appropriate for reading special lenses or rigid contact lenses. These advanced techniques are challenging but provide accurate diagnostic and lens verification data. One should never assume that the glasses the patient is wearing match what the doctor prescribed. The prescription should be checked at least once, even when there are no patient complaints. If possible, learn and practice these special procedures under the supervision of an optician or ophthalmic clinical trainer. This will help to verify that you are performing these special techniques correctly.

  18. Doublet Versus Single Agent as Second-Line Treatment for Advanced Gastric Cancer

    PubMed Central

    Zhang, Yong; Ma, Bing; Huang, Xiao-Tian; Li, Yan-Song; Wang, Yu; Liu, Zhou-Lu

    2016-01-01

    Abstract The purpose of this study was to perform a meta-analysis of randomized controlled trials (RCTs) to compare the efficacy and safety of doublet versus single agent as second-line treatment for advanced gastric cancer (AGC). A comprehensive literature search was performed to identify relevant RCTs. All clinical studies were independently identified by 2 authors for inclusion. Demographic data, treatment regimens, objective response rate (ORR), and progression-free survival (PFS) and overall survival (OS) were extracted and analyzed using Comprehensive Meta-Analysis software (Version 2.0). Ten RCTs involving 1698 pretreated AGC patients were ultimately identified. The pooled results demonstrated that doublet combination therapy as second-line treatment for AGC significantly improved OS (hazard ratio [HR] 0.87, 95% confidence interval [CI]: 0.78–0.97, P = 0.011), PFS (HR 0.79, 95% CI: 0.72–0.87, P < 0.001), and ORR (relative risk [RR] 1.57, 95% CI: 1.27–1.95, P < 0.001). Sub-group analysis according to treatment regimens also showed that targeted agent plus chemotherapy significantly improve OS, PFS, and ORR. However, no significant survival benefits had been observed in doublet cytotoxic chemotherapy when compared with single cytotoxic agent. Additionally, more incidences of grade 3 or 4 myelosuppression toxicities, diarrhea, and fatigue were observed in doublet combination groups, while equivalent frequencies of grade 3 or 4 thrombocytopenia and nausea were found between the 2 groups. In comparison with single cytotoxic agent alone, the addition of targeted agent to mono-chemotherapy as salvage treatment for pretreated AGC patients provide substantial survival benefits, while no significant survival benefits were observed in doublet cytotoxic chemotherapy regimens. PMID:26937908

  19. Advancement and results in hostile fire indication using potassium line missile warning sensors

    NASA Astrophysics Data System (ADS)

    Montgomery, Joel; Montgomery, Marjorie; Hardie, Russell

    2014-06-01

    M&M Aviation has been developing and conducting Hostile Fire Indication (HFI) tests using potassium line emission sensors for the Air Force Visible Missile Warning System (VMWS) to advance both algorithm and sensor technologies for UAV and other airborne systems for self protection and intelligence purposes. Work began in 2008 as an outgrowth of detecting and classifying false alarm sources for the VMWS using the same K-line spectral discrimination region but soon became a focus of research due to the high interest in both machine-gun fire and sniper geo-location via airborne systems. Several initial tests were accomplished in 2009 using small and medium caliber weapons including rifles. Based on these results, the Air Force Research Laboratory (AFRL) funded the Falcon Sentinel program in 2010 to provide for additional development of both the sensor concept, algorithm suite changes and verification of basic phenomenology including variance based on ammunition type for given weapons platform. Results from testing over the past 3 years have showed that the system would be able to detect and declare a sniper rifle at upwards of 3km, medium machine gun at 5km, and explosive events like hand-grenades at greater than 5km. This paper will outline the development of the sensor systems, algorithms used for detection and classification, and test results from VMWS prototypes as well as outline algorithms used for the VMWS. The Falcon Sentinel Program will be outlined and results shown. Finally, the paper will show the future work for ATD and transition efforts after the Falcon Sentinel program completed.

  20. Common determinants of body size and eye size in chickens from an advanced intercross line.

    PubMed

    Prashar, Ankush; Hocking, Paul M; Erichsen, Jonathan T; Fan, Qiao; Saw, Seang Mei; Guggenheim, Jeremy A

    2009-06-15

    Myopia development is characterised by an increased axial eye length. Therefore, identifying factors that influence eye size may provide new insights into the aetiology of myopia. In humans, axial length is positively correlated to height and weight, and in mice, eye weight is positively correlated with body weight. The purpose of this study was to examine the relationship between eye size and body size in chickens from a genetic cross in which alleles with major effects on eye and body size were segregating. Chickens from a cross between a layer line (small body size and eye size) and a broiler line (large body and eye size) were interbred for 10 generations so that alleles for eye and body size would have the chance to segregate independently. At 3 weeks of age, 510 chicks were assessed using in vivo high resolution A-scan ultrasonography and keratometry. Equatorial eye diameter and eye weight were measured after enucleation. The variations in eye size parameters that could be explained by body weight (BW), body length (BL), head width (HW) and sex were examined using multiple linear regression. It was found that BW, BL and HW and sex together predicted 51-56% of the variation in eye weight, axial length, corneal radius, and equatorial eye diameter. By contrast, the same variables predicted only 22% of the variation in lens thickness. After adjusting for sex, the three body size parameters predicted 45-49% of the variation in eye weight, axial length, corneal radius, and eye diameter, but only 0.4% of the variation in lens thickness. In conclusion, about half of the variation in eye size in the chickens of this broiler-layer advanced intercross line is likely to be determined by pleiotropic genes that also influence body size. Thus, mapping the quantitative trait loci (QTL) that determine body size may be useful in understanding the genetic determination of eye size (a logical inference of this result is that the 20 or more genetic variants that have recently

  1. Development of an immersed boundary-phase field-lattice Boltzmann method for Neumann boundary condition to study contact line dynamics

    NASA Astrophysics Data System (ADS)

    Shao, J. Y.; Shu, C.; Chew, Y. T.

    2013-02-01

    The implementation of Neumann boundary condition in the framework of immersed boundary method (IBM) is presented in this paper to simulate contact line dynamics using a phase field-lattice Boltzmann method. Immersed boundary method [10] is known as an efficient algorithm for modelling fluid-solid interaction. Abundance of prominent works have been devoted to refine IBM [1,11,12]. However, they are mainly restricted to problems with Dirichlet boundary condition. Research that implements the Neumann boundary condition in IBM is very limited to the best of our knowledge. This deficiency significantly limits the application of IBM in computational fluid dynamics (CFD) since physical phenomena associated with Neumann boundary conditions are extremely diverse. The difficulty is attributed to the fact that implementation of Neumann boundary condition is much more complex than that of Dirichlet boundary condition. In the present work, we initiate the first endeavour to implement Neumann boundary condition in IBM with assistance of its physical interpretation rather than simple mathematical manipulation. Concretely speaking, rooted from physical conservation law, the Neumann boundary condition is considered as contribution of flux from the boundary to its relevant physical parameter in a control volume. Moreover, the link between the flux and its corresponding flow field variable is directly manipulated through the immersed boundary concept. In this way, the Neumann boundary conditions can be implemented in IBM. The developed method is applied together with phase field-lattice Boltzmann method to study contact line dynamics. The phase field method [27,39], which becomes increasingly popular in multiphase flow simulation, can efficiently capture complex interface topology and naturally resolve the contact line singularity. Meanwhile, the lattice Boltzmann method is known as an alternative to model fluid dynamics and holds good prospect to simulate multiphase flows with

  2. Genome-wide association for fear conditioning in an advanced intercross mouse line.

    PubMed

    Parker, Clarissa C; Sokoloff, Greta; Cheng, Riyan; Palmer, Abraham A

    2012-05-01

    Fear conditioning (FC) may provide a useful model for some components of post-traumatic stress disorder (PTSD). We used a C57BL/6J × DBA/2J F(2) intercross (n = 620) and a C57BL/6J × DBA/2J F(8) advanced intercross line (n = 567) to fine-map quantitative trait loci (QTL) associated with FC. We conducted an integrated genome-wide association analysis in QTLRel and identified five highly significant QTL affecting freezing to context as well as four highly significant QTL associated with freezing to cue. The average percent decrease in QTL width between the F(2) and the integrated analysis was 59.2%. Next, we exploited bioinformatic sequence and expression data to identify candidate genes based on the existence of non-synonymous coding polymorphisms and/or expression QTLs. We identified numerous candidate genes that have been previously implicated in either fear learning in animal models (Bcl2, Btg2, Dbi, Gabr1b, Lypd1, Pam and Rgs14) or PTSD in humans (Gabra2, Oprm1 and Trkb); other identified genes may represent novel findings. The integration of F(2) and AIL data maintains the advantages of studying FC in model organisms while significantly improving resolution over previous approaches.

  3. Apatinib as post second-line therapy in EGFR wild-type and ALK-negative advanced lung adenocarcinoma

    PubMed Central

    Fang, Shen-Cun; Zhang, Hai-Tao; Zhang, Ying-Ming; Xie, Wei-Ping

    2017-01-01

    In the absence of a driver mutation, chemotherapy is the standard treatment option as first- and second-line therapy for advanced non-small-cell lung cancer (NSCLC). Though a large number of patients are suitable for post second-line therapies, the quality and quantity of the available drugs in this setting is poor. Apatinib, a small molecule vascular endothelial growth factor receptor-2 (VEGFR-2) tyrosine kinase inhibitor, is a first-generation oral antiangiogenesis drug approved in the People’s Republic of China for use as a subsequent line of treatment for advanced gastric cancer. Herein, we report three cases of advanced NSCLC with epidermal growth factor receptor wild-type and anaplastic lymphoma kinase-negative status, wherein the patients showed partial response to apatinib. Moreover, the three patients have achieved a progression-free survival of 2.8, 5.8, and 6 months, respectively. The main toxicities were hypertension, proteinuria, and hand–foot syndrome. Apatinib may provide an additional option for the treatment of advanced NSCLC, especially for advanced lung adenocarcinoma without a driver mutation. PMID:28176910

  4. Nanotopography induced contact guidance of the F11 cell line during neuronal differentiation: a neuronal model cell line for tissue scaffold development

    NASA Astrophysics Data System (ADS)

    Wieringa, Paul; Tonazzini, Ilaria; Micera, Silvestro; Cecchini, Marco

    2012-07-01

    The F11 hybridoma, a dorsal root ganglion-derived cell line, was used to investigate the response of nociceptive sensory neurons to nanotopographical guidance cues. This established this cell line as a model of peripheral sensory neuron growth for tissue scaffold design. Cells were seeded on substrates of cyclic olefin copolymer (COC) films imprinted via nanoimprint lithography (NIL) with a grating pattern of nano-scale grooves and ridges. Different ridge widths were employed to alter the focal adhesion formation, thereby changing the cell/substrate interaction. Differentiation was stimulated with forskolin in culture medium consisting of either 1 or 10% fetal bovine serum (FBS). Per medium condition, similar neurite alignment was achieved over the four day period, with the 1% serum condition exhibiting longer, more aligned neurites. Immunostaining for focal adhesions found the 1% FBS condition to also have fewer, less developed focal adhesions. The robust response of the F11 to guidance cues further builds on the utility of this cell line as a sensory neuron model, representing a useful tool to explore the design of regenerative guidance tissue scaffolds.

  5. An On-line Technology Information System (OTIS) for Advanced Life Support

    NASA Technical Reports Server (NTRS)

    Levri, Julie A.; Boulanger, Richard; Hogan, John A.; Rodriquez, Luis

    2003-01-01

    OTIS is an on-line communication platform designed for smooth flow of technology information between advanced life support (ALS) technology developers, researchers, system analysts, and managers. With pathways for efficient transfer of information, several improvements in the ALS Program will result. With OTIS, it will be possible to provide programmatic information for technology developers and researchers, technical information for analysts, and managerial decision support. OTIS is a platform that enables the effective research, development, and delivery of complex systems for life support. An electronic data collection form has been developed for the solid waste element, drafted by the Solid Waste Working Group. Forms for other elements (air revitalization, water recovery, food processing, biomass production and thermal control) will also be developed, based on lessons learned from the development of the solid waste form. All forms will be developed by consultation with other working groups, comprised of experts in the area of interest. Forms will be converted to an on-line data collection interface that technology developers will use to transfer information into OTIS. Funded technology developers will log in to OTIS annually to complete the element- specific forms for their technology. The type and amount of information requested expands as the technology readiness level (TRL) increases. The completed forms will feed into a regularly updated and maintained database that will store technology information and allow for database searching. To ensure confidentiality of proprietary information, security permissions will be customized for each user. Principal investigators of a project will be able to designate certain data as proprietary and only technical monitors of a task, ALS Management, and the principal investigator will have the ability to view this information. The typical OTIS user will be able to read all non-proprietary information about all projects

  6. An On-Line Technology Information System (OTIS) for Advanced Life Support

    NASA Technical Reports Server (NTRS)

    Levri, Julie A.; Boulanger, Richard; Hoganm John A.; Rodriquez, Luis

    2003-01-01

    An On-line Technology Information System (OTIS) is currently being developed for the Advanced Life Support (ALS) Program. This paper describes the preliminary development of OTIS, which is a system designed to provide centralized collection and organization of technology information. The lack of thorough, reliable and easily understood technology information is a major obstacle in effective assessment of technology development progress, trade studies, metric calculations, and technology selection for integrated testing. OTIS will provide a formalized, well-organized protocol to communicate thorough, accurate, current and relevant technology information between the hands-on technology developer and the ALS Community. The need for this type of information transfer system within the Solid Waste Management (SWM) element was recently identified and addressed. A SWM Technology Information Form (TIF) was developed specifically for collecting detailed technology information in the area of SWM. In the TIF, information is requested from SWM technology developers, based upon the Technology Readiness Level (TRL). Basic information is requested for low-TRL technologies, and more detailed information is requested as the TRL of the technology increases. A comparable form is also being developed for the wastewater processing element. In the future, similar forms will also be developed for the ALS elements of air revitalization, food processing, biomass production and thermal control. These ALS element-specific forms will be implemented in OTIS via a web-accessible interface,with the data stored in an object-oriented relational database (created in MySQLTM) located on a secure server at NASA Ames Research Center. With OTIS, ALS element leads and managers will be able to carry out informed research and development investment, thereby promoting technology through the TRL scale. OTIS will also allow analysts to make accurate evaluations of technology options. Additionally, the range

  7. Architecture and Functionality of the Advanced Life Support On-Line Project Information System (OPIS)

    NASA Technical Reports Server (NTRS)

    Hogan, John A.; Levri, Julie A.; Morrow, Rich; Cavazzoni, Jim; Rodriquez, Luis F.; Riano, Rebecca; Whitaker, Dawn R.

    2004-01-01

    An ongoing effort is underway at NASA Amcs Research Center (ARC) tu develop an On-line Project Information System (OPIS) for the Advanced Life Support (ALS) Program. The objective of this three-year project is to develop, test, revise and deploy OPIS to enhance the quality of decision-making metrics and attainment of Program goals through improved knowledge sharing. OPIS will centrally locate detailed project information solicited from investigators on an annual basis and make it readily accessible by the ALS Community via a web-accessible interface. The data will be stored in an object-oriented relational database (created in MySQL(Trademark) located on a secure server at NASA ARC. OPE will simultaneously serve several functions, including being an R&TD status information hub that can potentially serve as the primary annual reporting mechanism. Using OPIS, ALS managers and element leads will be able to carry out informed research and technology development investment decisions, and allow analysts to perform accurate systems evaluations. Additionally, the range and specificity of information solicited will serve to educate technology developers of programmatic needs. OPIS will collect comprehensive information from all ALS projects as well as highly detailed information specific to technology development in each ALS area (Waste, Water, Air, Biomass, Food, Thermal, and Control). Because the scope of needed information can vary dramatically between areas, element-specific technology information is being compiled with the aid of multiple specialized working groups. This paper presents the current development status in terms of the architecture and functionality of OPIS. Possible implementation approaches for OPIS are also discussed.

  8. Architecture and Functionality of the Advanced Life Support On-Line Project Information System

    NASA Technical Reports Server (NTRS)

    Hogan, John A.; Levri, Julie A.; Morrow, Rich; Cavazzoni, Jim; Rodriguez, Luis F.; Riano, Rebecca; Whitaker, Dawn R.

    2004-01-01

    An ongoing effort is underway at NASA Ames Research Center (ARC) to develop an On-line Project Information System (OPIS) for the Advanced Life Support (ALS) Program. The objective of this three-year project is to develop, test, revise and deploy OPIS to enhance the quality of decision-making metrics and attainment of Program goals through improved knowledge sharing. OPIS will centrally locate detailed project information solicited from investigators on an annual basis and make it readily accessible by the ALS Community via a Web-accessible interface. The data will be stored in an object-oriented relational database (created in MySQL) located on a secure server at NASA ARC. OPE will simultaneously serve several functions, including being an research and technology development (R&TD) status information hub that can potentially serve as the primary annual reporting mechanism for ALS-funded projects. Using OPIS, ALS managers and element leads will be able to carry out informed R&TD investment decisions, and allow analysts to perform accurate systems evaluations. Additionally, the range and specificity of information solicited will serve to educate technology developers of programmatic needs. OPIS will collect comprehensive information from all ALS projects as well as highly detailed information specific to technology development in each ALS area (Waste, Water, Air, Biomass, Food, Thermal, Controls and Systems Analysis). Because the scope of needed information can vary dramatically between areas, element-specific technology information is being compiled with the aid of multiple specialized working groups. This paper presents the current development status in terms of the architecture and functionality of OPIS. Possible implementation approaches for OPIS are also discussed.

  9. Reliable measurement of the receding contact angle.

    PubMed

    Korhonen, Juuso T; Huhtamäki, Tommi; Ikkala, Olli; Ras, Robin H A

    2013-03-26

    Surface wettability is usually evaluated by the contact angle between the perimeter of a water drop and the surface. However, this single measurement is not enough for proper characterization, and the so-called advancing and receding contact angles also need to be measured. Measuring the receding contact angle can be challenging, especially for extremely hydrophobic surfaces. We demonstrate a reliable procedure by using the common needle-in-the-sessile-drop method. Generally, the contact line movement needs to be followed, and true receding movement has to be distinguished from "pseudo-movement" occurring before the receding angle is reached. Depending on the contact angle hysteresis, the initial size of the drop may need to be surprisingly large to achieve a reliable result. Although our motivation for this work was the characterization of superhydrophobic surfaces, we also show that this method works universally ranging from hydrophilic to superhydrophobic surfaces.

  10. Lines

    ERIC Educational Resources Information Center

    Mires, Peter B.

    2006-01-01

    National Geography Standards for the middle school years generally stress the teaching of latitude and longitude. There are many creative ways to explain the great grid that encircles our planet, but the author has found that students in his college-level geography courses especially enjoy human-interest stories associated with lines of latitude…

  11. Adsorption at the solid-liquid interface as the source of contact angle dependence on the curvature of the three-phase line.

    PubMed

    Ward, C A; Sefiane, K

    2010-12-15

    We review the thermodynamic approach to determining the surface tension of solid-fluid interfaces. If the pressure is in the narrow range where the contact angle, θ, can exist, then for isothermal systems, adsorption at the solid-liquid interface affects γ(SL) or θ, but γ(SV) is very nearly equal γ(LV), the surface tension of the adsorbing fluid. For a liquid partially filling a cylinder, the pressure in the liquid phase at the three-phase line, x(3)(L), depends on the curvature of the three-phase line, C(cl), but the line tension can play no role, since it acts perpendicular to the cylinder wall. C(cl) is decreased as the cylinder diameter is increased; x(3)(L) is increased; and θ increases. For a given value of C(cl), x(3)(L) can be changed by rotating the cylinder or by changing the height of the three-phase line in a gravitational field. In all cases, for water in borosilicate glass cylinders, the value of θ is shown to increase as x(3)(L) is increased. This behaviour requires the Gibbsian adsorption at the solid-liquid interface to be negative, indicating the liquid concentration in the interphase is less than that in the bulk liquid. For sessile droplets, the value of θ depends on both x(3)(L) and C(cl). If the value of θ for spherical sessile droplets is measured as a function of C(cl), the adsorption at the solid-liquid interface that would give that dependence can be determined. It is unnecessary to introduce the line tension hypothesis to explain the dependence of θ on C(cl). Adsorption at the solid-liquid interface gives a full explanation.

  12. Modeling contact angle hysteresis on chemically patterned and superhydrophobic surfaces.

    PubMed

    Kusumaatmaja, H; Yeomans, J M

    2007-05-22

    We investigate contact angle hysteresis on chemically patterned and superhydrophobic surfaces, as the drop volume is quasistatically increased and decreased. We consider both two (cylindrical drops) and three (spherical drops) dimensions using analytical and numerical approaches to minimize the free energy of the drop. In two dimensions, we find, in agreement with other authors, a slip, jump, stick motion of the contact line. In three dimensions, this behavior persists, but the position and magnitude of the contact line jumps are sensitive to the details of the surface patterning. In two dimensions, we identify analytically the advancing and receding contact angles on the different surfaces, and we use numerical insights to argue that these provide bounds for the three-dimensional cases. We present explicit simulations to show that a simple average over the disorder is not sufficient to predict the details of the contact angle hysteresis and to support an explanation for the low contact angle hysteresis of suspended drops on superhydrophobic surfaces.

  13. New advances in on-line sample preconcentration by capillary electrophoresis using dynamic pH junction.

    PubMed

    Ptolemy, Adam S; Britz-McKibbin, Philip

    2008-12-01

    The small injection volumes and narrow dimensions characteristic of microseparation techniques place constraints on concentration sensitivity that is required for trace chemical analyses. On-line sample preconcentration techniques using dynamic pH junction and its variants have emerged as simple yet effective strategies for enhancing concentration sensitivity of weakly ionic species by capillary electrophoresis (CE). Dynamic pH junction offers a convenient format for electrokinetic focusing of dilute sample plugs directly in-capillary for improved detection without off-line sample pretreatment. In this report, we highlight new advances in dynamic pH junction which have been reported to enhance method performance while discussing challenges for future research.

  14. Contact dermatitis

    MedlinePlus

    Dermatitis - contact; Allergic dermatitis; Dermatitis - allergic; Irritant contact dermatitis; Skin rash - contact dermatitis ... There are 2 types of contact dermatitis. Irritant dermatitis: This ... can be by contact with acids, alkaline materials such as soaps ...

  15. Unified model for contact angle hysteresis on heterogeneous and superhydrophobic surfaces.

    PubMed

    Raj, Rishi; Enright, Ryan; Zhu, Yangying; Adera, Solomon; Wang, Evelyn N

    2012-11-13

    Understanding the complexities associated with contact line dynamics on chemically heterogeneous and superhydrophobic surfaces is important for a wide variety of engineering problems. Despite significant efforts to capture the behavior of a droplet on these surfaces over the past few decades, modeling of the complex dynamics at the three-phase contact line is needed. In this work, we demonstrate that contact line distortion on heterogeneous and superhydrophobic surfaces is the key aspect that needs to be accounted for in the dynamic droplet models. Contact line distortions were visualized and modeled using a thermodynamic approach to develop a unified model for contact angle hysteresis on chemically heterogeneous and superhydrophobic surfaces. On a surface comprised of discrete wetting defects on an interconnected less wetting area, the advancing contact angle was determined to be independent of the defects, while the relative fraction of the distorted contact line with respect to the baseline surface was shown to govern the receding contact angle. This behavior reversed when the relative wettability of the discrete defects and interconnected area was inverted. The developed model showed good agreement with the experimental advancing and receding contact angles, both at low and high solid fractions. The thermodynamic model was further extended to demonstrate its capability to capture droplet shape evolution during liquid addition and removal in our experiments and those in literature. This study offers new insight extending the fundamental understanding of solid-liquid interactions required for design of advanced functional coatings for microfluidics, biological, manufacturing, and heat transfer applications.

  16. Selecting first-line bevacizumab-containing therapy for advanced breast cancer: TURANDOT risk factor analyses

    PubMed Central

    Brodowicz, T; Lang, I; Kahan, Z; Greil, R; Beslija, S; Stemmer, S M; Kaufman, B; Petruzelka, L; Eniu, A; Anghel, R; Koynov, K; Vrbanec, D; Pienkowski, T; Melichar, B; Spanik, S; Ahlers, S; Messinger, D; Inbar, M J; Zielinski, C

    2014-01-01

    Background: The randomised phase III TURANDOT trial compared first-line bevacizumab–paclitaxel (BEV–PAC) vs bevacizumab–capecitabine (BEV–CAP) in HER2-negative locally recurrent/metastatic breast cancer (LR/mBC). The interim analysis revealed no difference in overall survival (OS; primary end point) between treatment arms; however, progression-free survival (PFS) and objective response rate were significantly superior with BEV–PAC. We sought to identify patient populations that may be most appropriately treated with one or other regimen. Methods: Patients with HER2-negative LR/mBC who had received no prior chemotherapy for advanced disease were randomised to either BEV–PAC (bevacizumab 10 mg kg−1 days 1 and 15 plus paclitaxel 90 mg m−2 days 1, 8 and 15 q4w) or BEV–CAP (bevacizumab 15 mg kg−1 day 1 plus capecitabine 1000 mg m−2 bid days 1–14 q3w). The study population was categorised into three cohorts: triple-negative breast cancer (TNBC), high-risk hormone receptor-positive (HR+) and low-risk HR+. High- and low-risk HR+ were defined, respectively, as having ⩾2 vs ⩽1 of the following four risk factors: disease-free interval ⩽24 months; visceral metastases; prior (neo)adjuvant anthracycline and/or taxane; and metastases in ⩾3 organs. Results: The treatment effect on OS differed between cohorts. Non-significant OS trends favoured BEV–PAC in the TNBC cohort and BEV–CAP in the low-risk HR+ cohort. In all three cohorts, there was a non-significant PFS trend favouring BEV–PAC. Grade ⩾3 adverse events were consistently less common with BEV–CAP. Conclusions: A simple risk factor index may help in selecting bevacizumab-containing regimens, balancing outcome, safety profile and patient preference. Final OS results are expected in 2015 (ClinicalTrials.gov NCT00600340). PMID:25268370

  17. Can dynamic contact angle be measured using molecular modeling?

    PubMed

    Malani, Ateeque; Raghavanpillai, Anilkumar; Wysong, Ernest B; Rutledge, Gregory C

    2012-11-02

    A method is presented for determining the dynamic contact angle at the three-phase contact between a solid, a liquid, and a vapor under an applied force, using molecular simulation. The method is demonstrated using a Lennard-Jones fluid in contact with a cylindrical shell of the fcc Lennard-Jones solid. Advancing and receding contact angles and the contact angle hysteresis are reported for the first time by this approach. The increase in force required to wet fully an array of solid cylinders (robustness) with decreasing separation distance between cylinders is evaluated. The dynamic contact angle is characterized by partial slipping of the three phase contact line when a force is applied.

  18. Etch Challenges Brought by the Metal Hardmask Approach for Advanced Contact Patterning with Fluorocarbon-based Plasma

    NASA Astrophysics Data System (ADS)

    de Marneffe, Jean-Francois; Goossens, Danny; Shamiryan, Denis; Struyf, Herbert; Boullart, Werner

    2008-10-01

    In order to overcome patterning challenges brought by dimensional scaling and aggressive pitches, extreme ultra-violet (EUV) lithography has been recently pushed forward as a possible solution for IC manufacturing, allowing extended exposure latitude at sub-50nm dimensions. This work address the technological solutions used for contact holes patterning by means of EUV lithography. A metal hard-mask (MHM) approach has been selected, in order to combine the etching of high-aspect ratio features with thin EUV photoresist. The pre-metal dielectric stack covering the active fins was composed of 15nm Si3N4 as an etch-stop liner, covered by 240nm SiO2. The MHM was made of a 30nm TiN film on top of which was spun 20nm of organic underlayer and 100nm of EUV photoresist. This presentation will describe in details the various plasma processing issues and challenges met with this patterning strategy, for down to ˜50nm contact hole sizes: SiO2:TiN and SiO2:Si3N4 selectivities by means of fluorocarbon-based chemistries; loading effects; profile and mask undercut control with CCP plasma; residue cleaning.

  19. Generation of dissolved organic matter and byproducts from activated sludge during contact with sodium hypochlorite and its implications to on-line chemical cleaning in MBR.

    PubMed

    Cai, Weiwei; Liu, Jiaqi; Zhang, Xiangru; Ng, Wun Jern; Liu, Yu

    2016-11-01

    On-line chemical cleaning of membranes with sodium hypochlorite (NaClO) has been commonly employed for maintaining a constant permeability of membrane bioreactor (MBR) due to its simple and efficient operation. However, activated sludge is inevitably exposed to NaClO during this cleaning process. In spite of the broad applications of on-line chemical cleaning in MBR such as chemical cleaning-in-place (CIP) and chemical enhanced backwash (CEB), little information is currently available for the release of emerging dissolved organic matter (DOM) and byproducts from this prevalent practice. Therefore, in this study, activated sludge suspended in a phosphate buffered saline solution was exposed to different doses of NaClO in order to determine the generation of potential DOM and byproducts. The results showed the occurrence of significant DOM release (up to 24.7 mg/L as dissolved organic carbon) after exposure to NaClO for 30 min. The dominant components of the released DOM were characterized to be humic acid-like as well as protein-like substances by using an excitation-emission matrix fluorescence spectrophotometer. Furthermore, after the contact of activated sludge with NaClO, 19 kinds of chlorinated and brominated byproducts were identified by ultra performance liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry, eight of which were confirmed and characterized with standard compounds. Many byproducts were found to be halogenated aromatic compounds, including halopyrroles and halo(hydro)benzoquinones, which had been reported to be significantly more toxic than the halogenated aliphatic ones. Consequently, this study offers new insights into the practice of on-line chemical cleaning, and opens up a window to re-examine the current operation of MBR by looking into the generation of micropollutants.

  20. Evaluation of Outcome and Tolerability of Combination Chemotherapy with Capecitabine and Oxaliplatin as First Line Therapy in Advanced Gastric Cancer.

    PubMed

    Mashhadi, Mohammad Ali; Sepehri, Zahra; Bakhshipour, Ali Reza; Zivari, Ali; Danesh, Hossein Ali; Metanat, Hasan Ali; Karimkoshteh, Azra; Hashemi, Seyed Mehdi; Rahimi, Hossein; Kiani, Zohre

    2016-10-01

    Background: Combination chemotherapy is accepted as a high efficacy treatment for gastric cancer, whereas choice of standard treatment is unclear. Multiple chemotherapeutic regimens have been used to achieve higher efficacy and lower toxicity. This study was designed to evaluate the treatment results of advanced gastric cancer with Capecitabine and Oxaliplatin regimen. Subjects and Methods: All cases with documented gastric adenocarcinoma and advanced disease were candidates for receiving Xelox regimen (Capecitabine - 750 mg/m(2)/twice daily/ 1-14 days and Oxaliplatin 125 mg/m(2) in 1st day). Results: Twenty five cases with advanced gastric cancer entered in study while 24 cases continued treatment protocol and were evaluated. Mean age was 59.5 ± 12.1 years (range: 20-75), male and female cases were 66.7% and 33.3%, respectively. All cases received at least four cycles of Xelox regimen. Overall response rate was 74.99% with 29.16% complete response. Overall survival rate was 13 ± 0.53 months and DFS (disease-free survival) was 6 ± 1.09 months. Extremities neuropathy (62.5%), headache (45.8%) and muscle cramps (29.2%) were the most common complains. Haematological changes were rare and 16.7% of cases had mild cytopenia. Treatment related death was not observed. Conclusion: Xelox regimen is a safe and highly effective first line treatment for gastric cancer; however, considering it as first line therapy needs larger studies.

  1. Evaluation of Outcome and Tolerability of Combination Chemotherapy with Capecitabine and Oxaliplatin as First Line Therapy in Advanced Gastric Cancer

    PubMed Central

    Mashhadi, Mohammad Ali; Sepehri, Zahra; Bakhshipour, Ali Reza; Zivari, Ali; Danesh, Hossein Ali; Metanat, Hasan Ali; Karimkoshteh, Azra; Hashemi, Seyed Mehdi; Rahimi, Hossein; Kiani, Zohre

    2016-01-01

    Background: Combination chemotherapy is accepted as a high efficacy treatment for gastric cancer, whereas choice of standard treatment is unclear. Multiple chemotherapeutic regimens have been used to achieve higher efficacy and lower toxicity. This study was designed to evaluate the treatment results of advanced gastric cancer with Capecitabine and Oxaliplatin regimen. Subjects and Methods : All cases with documented gastric adenocarcinoma and advanced disease were candidates for receiving Xelox regimen (Capecitabine – 750 mg/m2/twice daily/ 1-14 days and Oxaliplatin 125 mg/m2 in 1st day). Results: Twenty five cases with advanced gastric cancer entered in study while 24 cases continued treatment protocol and were evaluated. Mean age was 59.5 ± 12.1 years (range: 20-75), male and female cases were 66.7% and 33.3%, respectively. All cases received at least four cycles of Xelox regimen. Overall response rate was 74.99% with 29.16% complete response. Overall survival rate was 13 ± 0.53 months and DFS (disease-free survival) was 6 ± 1.09 months. Extremities neuropathy (62.5%), headache (45.8%) and muscle cramps (29.2%) were the most common complains. Haematological changes were rare and 16.7% of cases had mild cytopenia. Treatment related death was not observed. Conclusion: Xelox regimen is a safe and highly effective first line treatment for gastric cancer; however, considering it as first line therapy needs larger studies. PMID:27928475

  2. Statistical analysis of Contact Angle Hysteresis

    NASA Astrophysics Data System (ADS)

    Janardan, Nachiketa; Panchagnula, Mahesh

    2015-11-01

    We present the results of a new statistical approach to determining Contact Angle Hysteresis (CAH) by studying the nature of the triple line. A statistical distribution of local contact angles on a random three-dimensional drop is used as the basis for this approach. Drops with randomly shaped triple lines but of fixed volumes were deposited on a substrate and their triple line shapes were extracted by imaging. Using a solution developed by Prabhala et al. (Langmuir, 2010), the complete three dimensional shape of the sessile drop was generated. A distribution of the local contact angles for several such drops but of the same liquid-substrate pairs is generated. This distribution is a result of several microscopic advancing and receding processes along the triple line. This distribution is used to yield an approximation of the CAH associated with the substrate. This is then compared with measurements of CAH by means of a liquid infusion-withdrawal experiment. Static measurements are shown to be sufficient to measure quasistatic contact angle hysteresis of a substrate. The approach also points towards the relationship between microscopic triple line contortions and CAH.

  3. Role of regorafenib as second-line therapy and landscape of investigational treatment options in advanced hepatocellular carcinoma.

    PubMed

    Trojan, Jörg; Waidmann, Oliver

    2016-01-01

    Sorafenib is still the only systemic drug approved for the treatment of advanced hepatocellular carcinoma (HCC). In recent years, several investigational agents mainly targeting angiogenesis failed in late-phase clinical development due to either toxicity or lack of benefit. Recently, data of the RESORCE trial, a placebo-controlled Phase III study that evaluated the efficacy and safety of regorafenib in patients with HCC and documented disease progression after systemic first-line treatment with sorafenib, were presented at the ESMO World Congress on Gastrointestinal Cancer, 2016. Regorafenib treatment resulted in a 2.8-month survival benefit compared to placebo (10.6 months vs 7.8 months). Side effects were consistent with the known profile of regorafenib. The approval of regorafenib for this indication is expected in 2017. Further candidate agents in Phase III evaluation for second-line treatment of patients with HCC are the MET inhibitors tivantinib and cabozantinib, the vascular endothelial growth factor receptor-2 antibody ramucirumab, and the programmed death receptor-1 (PD-1) blocking antibody pembrolizumab. Furthermore, results from two first-line trials with either the tyrosine kinase inhibitor lenvatinib or the PD-1 antibody nivolumabin in comparison to sorafenib are awaited in the near future and might further change the treatment sequence of advanced HCC.

  4. Role of regorafenib as second-line therapy and landscape of investigational treatment options in advanced hepatocellular carcinoma

    PubMed Central

    Trojan, Jörg; Waidmann, Oliver

    2016-01-01

    Sorafenib is still the only systemic drug approved for the treatment of advanced hepatocellular carcinoma (HCC). In recent years, several investigational agents mainly targeting angiogenesis failed in late-phase clinical development due to either toxicity or lack of benefit. Recently, data of the RESORCE trial, a placebo-controlled Phase III study that evaluated the efficacy and safety of regorafenib in patients with HCC and documented disease progression after systemic first-line treatment with sorafenib, were presented at the ESMO World Congress on Gastrointestinal Cancer, 2016. Regorafenib treatment resulted in a 2.8-month survival benefit compared to placebo (10.6 months vs 7.8 months). Side effects were consistent with the known profile of regorafenib. The approval of regorafenib for this indication is expected in 2017. Further candidate agents in Phase III evaluation for second-line treatment of patients with HCC are the MET inhibitors tivantinib and cabozantinib, the vascular endothelial growth factor receptor-2 antibody ramucirumab, and the programmed death receptor-1 (PD-1) blocking antibody pembrolizumab. Furthermore, results from two first-line trials with either the tyrosine kinase inhibitor lenvatinib or the PD-1 antibody nivolumabin in comparison to sorafenib are awaited in the near future and might further change the treatment sequence of advanced HCC. PMID:27703962

  5. How Water Advances on Superhydrophobic Surfaces

    NASA Astrophysics Data System (ADS)

    Schellenberger, Frank; Encinas, Noemí; Vollmer, Doris; Butt, Hans-Jürgen

    2016-03-01

    Superliquid repellency can be achieved by nano- and microstructuring surfaces in such a way that protrusions entrap air underneath the liquid. It is still not known how the three-phase contact line advances on such structured surfaces. In contrast to a smooth surface, where the contact line can advance continuously, on a superliquid-repellent surface, the contact line has to overcome an air gap between protrusions. Here, we apply laser scanning confocal microscopy to get the first microscopic videos of water drops advancing on a superhydrophobic array of micropillars. In contrast to common belief, the liquid surface gradually bends down until it touches the top face of the next micropillars. The apparent advancing contact angle is 180°. On the receding side, pinning to the top faces of the micropillars determines the apparent receding contact angle. Based on these observations, we propose that the apparent receding contact angle should be used for characterizing superliquid-repellent surfaces rather than the apparent advancing contact angle and hysteresis.

  6. Improvement on post-OPC verification efficiency for contact/via coverage check by final CD biasing of metal lines and considering their location on the metal layout

    NASA Astrophysics Data System (ADS)

    Kim, Youngmi; Choi, Jae-Young; Choi, Kwangseon; Choi, Jung-Hoe; Lee, Sooryong

    2011-04-01

    As IC design complexity keeps increasing, it is more and more difficult to ensure the pattern transfer after optical proximity correction (OPC) due to the continuous reduction of layout dimensions and lithographic limitation by k1 factor. To guarantee the imaging fidelity, resolution enhancement technologies (RET) such as off-axis illumination (OAI), different types of phase shift masks and OPC technique have been developed. In case of model-based OPC, to cross-confirm the contour image versus target layout, post-OPC verification solutions continuously keep developed - contour generation method and matching it to target structure, method for filtering and sorting the patterns to eliminate false errors and duplicate patterns. The way to detect only real errors by excluding false errors is the most important thing for accurate and fast verification process - to save not only reviewing time and engineer resource, but also whole wafer process time and so on. In general case of post-OPC verification for metal-contact/via coverage (CC) check, verification solution outputs huge of errors due to borderless design, so it is too difficult to review and correct all points of them. It should make OPC engineer to miss the real defect, and may it cause the delay time to market, at least. In this paper, we studied method for increasing efficiency of post-OPC verification, especially for the case of CC check. For metal layers, final CD after etch process shows various CD bias, which depends on distance with neighbor patterns, so it is more reasonable that consider final metal shape to confirm the contact/via coverage. Through the optimization of biasing rule for different pitches and shapes of metal lines, we could get more accurate and efficient verification results and decrease the time for review to find real errors. In this paper, the suggestion in order to increase efficiency of OPC verification process by using simple biasing rule to metal layout instead of etch model

  7. How pinning and contact angle hysteresis govern quasi-static liquid drop transfer.

    PubMed

    Chen, H; Tang, T; Zhao, H; Law, K-Y; Amirfazli, A

    2016-02-21

    This paper presents both experimental and numerical simulations of liquid transfer between two solid surfaces with contact angle hysteresis (CAH). Systematic studies on the role of the advancing contact angle (θa), receding contact angle (θr) and CAH in determining the transfer ratio (volume of the liquid transferred onto the acceptor surface over the total liquid volume) and the maximum adhesion force (Fmax) were performed. The transfer ratio was found to be governed by contact line pinning at the end of the transfer process caused by CAH of surfaces. A map based on θr of the two surfaces was generated to identify the three regimes for liquid transfer: (I) contact line pinning occurs only on the donor surface, (II) contact line pinning occurs on both surfaces, and (III) contact line pinning occurs only on the acceptor surface. With this map, an empirical equation is provided which is able to estimate the transfer ratio by only knowing θr of the two surfaces. The value of Fmax is found to be strongly influenced by the contact line pinning in the early stretching stage. For symmetric liquid bridges between two identical surfaces, Fmax may be determined only by θa, only by θr, or by both θa and θr, depending on the magnitude of the contact angles. For asymmetric bridges, Fmax is found to be affected by the period when contact lines are pinned on both surfaces.

  8. Advances in prevention and management of central line-associated bloodstream infections in patients with cancer.

    PubMed

    Raad, Issam; Chaftari, Anne-Marie

    2014-11-15

    Central lines, which are essential for treating cancer, are associated with at least 400,000 episodes of bloodstream infection in patients with cancer every year in the United States. Effective novel interventions for preventing and managing these infections include antimicrobial-coated catheters and antimicrobial lock solutions.

  9. Evaluation of verticillium wilt resistance in commercial cultivars and advanced breeding lines of cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Verticillium wilt (VW), caused by Verticillium dahliae Kleb, is one of the most destructive diseases in cotton (Gossypium spp.). The most efficient and cost-effective method of controlling the disease is the use of resistant cotton cultivars. Most commercial cultivars and elite breeding lines are de...

  10. Second- and third-line systemic therapy in patients with advanced esophagogastric cancer: a systematic review of the literature.

    PubMed

    Ter Veer, Emil; Haj Mohammad, Nadia; van Valkenhoef, Gert; Ngai, Lok Lam; Mali, Rosa M A; van Oijen, Martijn G H; van Laarhoven, Hanneke W M

    2016-09-01

    The optimal second- and third-line chemotherapy and targeted therapy for patients with advanced esophagogastric cancer is still a matter of debate. Therefore, a literature search was carried out in Medline, EMBASE, CENTRAL, and oncology conferences until January 2016 for randomized controlled trials that compared second- or third-line therapy. We included 28 studies with 4810 patients. Second-line, single-agent taxane/irinotecan showed increased survival compared to best supportive care (BSC) (hazard ratio 0.65, 95 % confidence interval 0.53-0.79). Median survival gain ranged from 1.4 to 2.7 months among individual studies. Taxane- and irinotecan-based regimens showed equal survival benefit. Doublet chemotherapy taxane/irinotecan plus platinum and fluoropyrimidine was not different in survival, but showed increased toxicity vs. taxane/irinotecan monotherapy. Compared to BSC, second-line ramucirumab and second- or third-line everolimus and regorafenib showed limited median survival gain ranging from 1.1 to 1.4 months, and progression-free survival gain, ranging from 0.3 to 1.6 months. Third- or later-line apatinib showed increased survival benefit over BSC (HR 0.50, 0.32-0.79). Median survival gain ranged from 1.8 to 2.3 months. Compared to taxane-alone, survival was superior for second-line ramucirumab plus taxane (HR 0.81, 0.68-0.96), and olaparib plus taxane (HR 0.56, 0.35-0.87), with median survival gains of 2.2 and 4.8 months respectively. Targeted agents, either in monotherapy or combined with chemotherapy showed increased toxicity compared to BSC and chemotherapy-alone. This review indicates that, given the survival benefit in a phase III study setting, ramucirumab plus taxane is the preferred second-line treatment. Taxane or irinotecan monotherapy are alternatives, although the absolute survival benefit was limited. In third-line setting, apatinib monotherapy is preferred.

  11. R and D advances in corrosion and crack monitoring for oil and gas lines

    SciTech Connect

    Atherton, D.L.; Czura, W.; Krause, T.W.; Laursen, P.; Mergelas, B.; Hauge, C.

    1996-12-31

    Magnetic Flux Leakage (MFL) inspection techniques for in-line corrosion monitoring of pipelines continue to evolve rapidly. Current R and D is aimed at improving the accuracy and reliability of defect sizing. Major issues are the variability and consequent need to characterize the magnetic properties of the pipes and the effects of line pressure, residual and bending stresses on MFL signals. Magnetic Barkhausen Noise (MBN) measurements are being used to study the stress-induced changes in magnetic anisotropy. Remote Field Eddy Current (RFEC) techniques are being investigated for detection and measurement of stress corrosion cracking in gas pipelines. Anomalous defect source models have improved the detailed explanation of crack defect interactions greatly.

  12. Stress migration risk on electromigration reliability in advanced narrow line copper interconnects

    NASA Astrophysics Data System (ADS)

    Heryanto, A.; Pey, K. L.; Lim, Y. K.; Raghavan, N.; Liu, W.; Wei, J.; Gan, C. L.; Tan, J. B.

    2011-10-01

    The influence of stress migration (SM) on the electromigration (EM) reliability is studied here for very fine line interconnects, fabricated using the 45-nm Cu/low-κ interconnect process flow. As opposed to the current understanding that SM is not a concern for the narrow metal lines because of limited availability of vacancies for voiding, we found that SM does have serious wear-out effects. The EM lifetime distribution was severely degraded by around 38% for the samples that had been subjected to a 1000-h SM-only test, with a drastic reduction in the slope of the EM lognormal fitting distribution, from 0.548 to 0.193. The current density exponent of Black's equation for SM+EM stressed samples is ˜1, suggesting that void had already been nucleated because of the SM-only test. The high intrinsic tensile stress in the line is suspected to be responsible for this early void nucleation. In the second part, we developed a Monte Carlo simulation model to estimate the void nucleation and growth time using the EM-only and SM+EM degradation tests. We found that at low percentile failures overall failure time is mainly growth dominated, whereas at high percentile failures overall failure time is nucleation dominated. Stress migration was found to shorten the nucleation time for all the samples.

  13. Contact angle hysteresis on fluoropolymer surfaces.

    PubMed

    Tavana, H; Jehnichen, D; Grundke, K; Hair, M L; Neumann, A W

    2007-10-31

    Contact angle hysteresis of liquids with different molecular and geometrical properties on high quality films of four fluoropolymers was studied. A number of different causes are identified for hysteresis. With n-alkanes as probe liquids, contact angle hysteresis is found to be strongly related to the configuration of polymer chains. The largest hysteresis is obtained with amorphous polymers whereas the smallest hysteresis occurs for polymers with ordered molecular chains. This is explained in terms of sorption of liquid by the solid and penetration of liquid into the polymer film. Correlation of contact angle hysteresis with the size of n-alkane molecules supports this conclusion. On the films of two amorphous fluoropolymers with different molecular configurations, contact angle hysteresis of one and the same liquid with "bulky" molecules is shown to be quite different. On the surfaces of Teflon AF 1600, with stiff molecular chains, the receding angles of the probe liquids are independent of contact time between solid and liquid and similar hysteresis is obtained for all the liquids. Retention of liquid molecules on the solid surface is proposed as the most likely cause of hysteresis in these systems. On the other hand, with EGC-1700 films that consist of flexible chains, the receding angles are strongly time-dependent and the hysteresis is large. Contact angle hysteresis increases even further when liquids with strong dipolar intermolecular forces are used. In this case, major reorganization of EGC-1700 chains due to contact with the test liquids is suggested as the cause. The effect of rate of motion of the three-phase line on the advancing and receding contact angles, and therefore contact angle hysteresis, is investigated. For low viscous liquids, contact angles are independent of the drop front velocity up to approximately 10 mm/min. This agrees with the results of an earlier study that showed that the rate-dependence of the contact angles is an issue only

  14. Contact angle hysteresis on superhydrophobic stripes.

    PubMed

    Dubov, Alexander L; Mourran, Ahmed; Möller, Martin; Vinogradova, Olga I

    2014-08-21

    We study experimentally and discuss quantitatively the contact angle hysteresis on striped superhydrophobic surfaces as a function of a solid fraction, ϕS. It is shown that the receding regime is determined by a longitudinal sliding motion of the deformed contact line. Despite an anisotropy of the texture the receding contact angle remains isotropic, i.e., is practically the same in the longitudinal and transverse directions. The cosine of the receding angle grows nonlinearly with ϕS. To interpret this we develop a theoretical model, which shows that the value of the receding angle depends both on weak defects at smooth solid areas and on the strong defects due to the elastic energy of the deformed contact line, which scales as ϕS(2)lnϕS. The advancing contact angle was found to be anisotropic, except in a dilute regime, and its value is shown to be determined by the rolling motion of the drop. The cosine of the longitudinal advancing angle depends linearly on ϕS, but a satisfactory fit to the data can only be provided if we generalize the Cassie equation to account for weak defects. The cosine of the transverse advancing angle is much smaller and is maximized at ϕS ≃ 0.5. An explanation of its value can be obtained if we invoke an additional energy due to strong defects in this direction, which is shown to be caused by the adhesion of the drop on solid sectors and is proportional to ϕS(2). Finally, the contact angle hysteresis is found to be quite large and generally anisotropic, but it becomes isotropic when ϕS ≤ 0.2.

  15. A directly cooled grating substrate for ALS (Advanced Light Source) undulator beam lines

    SciTech Connect

    DiGennaro, R.; Swain, T.

    1989-08-01

    Design analyses using finite element methods are presented for thermal distortion of water-cooled diffraction grating substrates for a potential application at the LBL Advanced Light Source, demonstrating that refinements in cooling channel configuration and heat flux distribution can significantly reduce optical surface distortion with high heat loads. Using an existing grating substrate design, sensitivity of tangential slope errors due to thermal distortion is evaluated for a variety of thermal boundary conditions, including coolant flow rate and heat transfer film coefficients, surface illumination area and heat distribution profile, and location of the convection cooling surfaces adjacent to the heated region. 1 ref., 5 figs., 2 tabs.

  16. Experimental equipment for an advanced ISOL facility[Isotope Separation On-Line Facility

    SciTech Connect

    Baktash, C.; Lee, I.Y.; Rehm, K.E.

    1999-03-01

    This report summarizes the proceedings and recommendations of the Workshop on the Experimental Equipment for an Advanced ISOL Facility which was held at Lawrence Berkeley National Laboratory on July 22--25, 1998. The purpose of this workshop was to discuss the performance requirements, manpower and cost estimates, as well as a schedule of the experimental equipment needed to fully exploit the new physics which can be studied at an advanced ISOL facility. An overview of the new physics opportunities that would be provided by such a facility has been presented in the White Paper that was issued following the Columbus Meeting. The reactions and experimental techniques discussed in the Columbus White Paper served as a guideline for the formulation of the detector needs at the Berkeley Workshop. As outlined a new ISOL facility with intense, high-quality beams of radioactive nuclei would provide exciting new research opportunities in the areas of: the nature of nucleonic matter; the origin of the elements; and tests of the Standard Model. After an introductory section, the following equipment is discussed: gamma-ray detectors; recoil separators; magnetic spectrographs; particle detectors; targets; and apparatus using non-accelerated beams.

  17. Lubrication Of Nonconformal Contacts

    NASA Technical Reports Server (NTRS)

    Jeng, Yeau-Ren

    1991-01-01

    Report discusses advances in knowledge of lubrication of nonconformal contacts in bearings and other machine elements. Reviews previous developments in theory of lubrication, presents advances in theory of lubrication to determine minimum film thickness, and describes experiments designed to investigate one of regimes of lubrication for ball bearings.

  18. High contact angle hysteresis of superhydrophobic surfaces: Hydrophobic defects

    NASA Astrophysics Data System (ADS)

    Chang, Feng-Ming; Hong, Siang-Jie; Sheng, Yu-Jane; Tsao, Heng-Kwong

    2009-08-01

    A typical superhydrophobic surface is essentially nonadhesive and exhibits very low water contact angle (CA) hysteresis, so-called Lotus effect. However, leaves of some plants such as scallion and garlic with an advancing angle exceeding 150° show very serious CA hysteresis. Although surface roughness and epicuticular wax can explain the very high advancing CA, our analysis indicates that the unusual hydrophobic defect, diallyl disulfide, is the key element responsible for contact line pinning on allium leaves. After smearing diallyl disulfide on an extended polytetrafluoroethylene (PTFE) film, which is originally absent of CA hysteresis, the surface remains superhydrophobic but becomes highly adhesive.

  19. Droplet compression and relaxation by a superhydrophobic surface: contact angle hysteresis.

    PubMed

    Hong, Siang-Jie; Chou, Tung-He; Chan, Seong Heng; Sheng, Yu-Jane; Tsao, Heng-Kwong

    2012-04-03

    In this article, the contact angle hysteresis (CAH) of acrylic glass is experimentally and theoretically studied through the compression-relaxation process of droplets by using a superhydrophobic surface with negligible CAH effect. In contrast to the existing technique in which the volume of the droplet changes during the measurement of CAH, this procedure is carried out at a constant volume of the droplet. By observing the base diameter (BD) and the contact angle (CA) of the droplet during the compression-relaxation process, the wetting behavior of the droplet can be divided into two regimes, the contact line withdrawal and the contact line pinning regimes, depending on the gap thickness (H) at the end of the compression process. During the compression process, both regimes possess similar droplet behavior; the contact line will move outward and the BD will expand while the CA remains at the advancing angle. During the relaxation process, the two regimes are significantly different. In the contact line withdrawal regime, the contact line will withdraw with the CA remaining at the receding angle. In the contact line pinning regime, however, the contact line will be pinned at the final position and the CA will decline to a certain value higher than the receding angle. Furthermore, the advancing pinning behavior can also be realized through a successive compression-relaxation process. On the basis of the liquid-induced defects model, Surface Evolver simulations are performed to reproduce the behavior of the droplet during the compression-relaxation process; both contact line withdrawal and pinning regimes can also be identified. The results of the experiment and simulation agree with each other very well.

  20. In-line monitoring of advanced copper CMP processes with picosecond ultrasonic metrology

    NASA Astrophysics Data System (ADS)

    Hsieh, Ming Hsun; Yeh, J. H.; Tsai, Mingsheng; Yang, Chan Lon; Tan, John; Leary, Sean Patrick

    2006-03-01

    Chemical mechanical planarization (CMP) is a challenging process step for manufacturers implementing dualdamascene architectures at the 65 nm technology node. The polishing rate can vary significantly from wafer-to-wafer, across a single wafer, and across a single die, depending on factors including electroplate profile, slurry chemistry, pad wear, and underlying structure. The process is further complicated by the introduction of low-k dielectrics that have significantly different mechanical properties than the harder SiO II they replace. Picosecond ultrasonics is a nondestructive, small-spot method that can be used for in-line on-product monitoring of metal processes including copper CMP. In this paper we will present gauge-capable picosecond ultrasonic results on copper erosion test structures that also demonstrate excellent correlation with electrical test measurements and TEM results on 65 nm products.

  1. Modeling liquid bridge between surfaces with contact angle hysteresis.

    PubMed

    Chen, H; Amirfazli, A; Tang, T

    2013-03-12

    This paper presents the behaviors of a liquid bridge when being compressed and stretched in a quasi-static fashion between two solid surfaces that have contact angle hysteresis (CAH). A theoretical model is developed to obtain the profiles of the liquid bridge given a specific separation between the surfaces. Different from previous models, both contact lines in the upper and lower surfaces were allowed to move when the contact angles reach their advancing or receding values. When the contact angles are between their advancing and receding values, the contact lines are pinned while the contact angles adjust to accommodate the changes in separation. Effects of CAH on both asymmetric and symmetric liquid bridges were analyzed. The model was shown to be able to correctly predict the behavior of the liquid bridge during a quasi-static compression/stretching loading cycle in experiments. Because of CAH, the liquid bridge can have two different profiles at the same separation during one loading and unloading cycle, and more profiles can be obtained during multiple cycles. The maximum adhesion force generated by the liquid bridge is found to be influenced by the CAH of surfaces. CAH also leads to energy cost during a loading cycle of the liquid bridge. In addition, the minimum separation between the two solid surfaces is shown to affect how the contact radii and angles change on the two surfaces as the liquid bridge is stretched.

  2. Advanced Discontinuous Galerkin Algorithms and First Open-Field Line Turbulence Simulations

    NASA Astrophysics Data System (ADS)

    Hammett, G. W.; Hakim, A.; Shi, E. L.

    2016-10-01

    New versions of Discontinuous Galerkin (DG) algorithms have interesting features that may help with challenging problems of higher-dimensional kinetic problems. We are developing the gyrokinetic code Gkeyll based on DG. DG also has features that may help with the next generation of Exascale computers. Higher-order methods do more FLOPS to extract more information per byte, thus reducing memory and communications costs (which are a bottleneck at exascale). DG uses efficient Gaussian quadrature like finite elements, but keeps the calculation local for the kinetic solver, also reducing communication. Sparse grid methods might further reduce the cost significantly in higher dimensions. The inner product norm can be chosen to preserve energy conservation with non-polynomial basis functions (such as Maxwellian-weighted bases), which can be viewed as a Petrov-Galerkin method. This allows a full- F code to benefit from similar Gaussian quadrature as used in popular δf gyrokinetic codes. Consistent basis functions avoid high-frequency numerical modes from electromagnetic terms. We will show our first results of 3 x + 2 v simulations of open-field line/SOL turbulence in a simple helical geometry (like Helimak/TORPEX), with parameters from LAPD, TORPEX, and NSTX. Supported by the Max-Planck/Princeton Center for Plasma Physics, the SciDAC Center for the Study of Plasma Microturbulence, and DOE Contract DE-AC02-09CH11466.

  3. Toxicities of different first-line chemotherapy regimens in the treatment of advanced ovarian cancer

    PubMed Central

    Qu, Chang-Ping; Sun, Gui-Xia; Yang, Shao-Qin; Tian, Jun; Si, Jin-Ge; Wang, Yi-Feng

    2017-01-01

    Abstract Background: Ovarian cancer (OC) is the 5th leading cause of cancer-related deaths around the world, and several chemotherapy regimens have been applied in the treatment of OC. We aim to compare toxicities of different chemotherapy regimens in the treatment of advanced ovarian cancer (AOC) using network meta-analysis. Methods: Literature research in Cochrane Library, PubMed, and EMBASE was performed up to November 2015. Eligible randomized controlled trials (RCTs) of different chemotherapy regimens were included. Network meta-analysis combined direct and indirect evidence to assess pooled odds ratios (ORs) and draw the surface under the cumulative ranking (SUCRA) curves. Results: Thirteen eligible RCTs were included in this network meta-analysis, including 8 chemotherapy regimens (paclitaxel + carboplatin [PC], pegylated liposomal doxorubicin [PLD] + carboplatin, carboplatin, gemcitabine + carboplatin, paclitaxel, PC + epirubicin, PC + topotecan, docetaxel + carboplatin). Gemcitabine + carboplatin regimen exerted higher incidence of anemia when compared with carboplatin and paclitaxel regimens. The incidence of febrile neutropenia of gemcitabine + carboplatin regimen was higher than that of PC, PLD + carboplatin, carboplatin, and PC + topotecan regimens. Topotecan PC + epirubicin regimen had a higher toxicity, comparing with PC, PLD + carboplatin, and PC + topotecan regimens. As for thrombocytopenia, gemcitabine + carboplatin chemotherapy regimen produced an obviously higher toxicity than PC and carboplatin. As for nausea, PLD + carboplatin chemotherapy regimen had a significantly higher toxicity than that of carboplatin chemotherapy regimen. Moreover, when compared with PC and carboplatin chemotherapy regimens, the toxicity of PC + epirubicin was greatly higher to patients with AOC. Conclusion: The nonhematologic toxicity of PLD + carboplatin regimen was higher than other regimens, which

  4. StrandAdvantage test for early-line and advanced-stage treatment decisions in solid tumors.

    PubMed

    Sen, Manimala; Katragadda, Shanmukh; Ravichandran, Aarthi; Deshpande, Gouri; Parulekar, Minothi; Nayanala, Swetha; Vittal, Vikram; Shen, Weiming; Phooi Nee Yong, Melanie; Jacob, Jemima; Parchuru, Sravanthi; Dhanuskodi, Kalpana; Eyring, Kenneth; Agrawal, Pooja; Agarwal, Smita; Shanmugam, Ashwini; Gupta, Satish; Vishwanath, Divya; Kumari, Kiran; Hariharan, Arun K; Balaji, Sai A; Liang, Qiaoling; Robolledo, Belen; Gauribidanur Raghavendrachar, Vijayashree; Oomer Farooque, Mohammed; Buresh, Cary J; Ramamoorthy, Preveen; Bahadur, Urvashi; Subramanian, Kalyanasundaram; Hariharan, Ramesh; Veeramachaneni, Vamsi; Sankaran, Satish; Gupta, Vaijayanti

    2017-04-03

    Comprehensive genetic profiling of tumors using next-generation sequencing (NGS) is gaining acceptance for guiding treatment decisions in cancer care. We designed a cancer profiling test combining both deep sequencing and immunohistochemistry (IHC) of relevant cancer targets to aid therapy choices in both standard-of-care (SOC) and advanced-stage treatments for solid tumors. The SOC report is provided in a short turnaround time for four tumors, namely lung, breast, colon, and melanoma, followed by an investigational report. For other tumor types, an investigational report is provided. The NGS assay reports single-nucleotide variants (SNVs), copy number variations (CNVs), and translocations in 152 cancer-related genes. The tissue-specific IHC tests include routine and less common markers associated with drugs used in SOC settings. We describe the standardization, validation, and clinical utility of the StrandAdvantage test (SA test) using more than 250 solid tumor formalin-fixed paraffin-embedded (FFPE) samples and control cell line samples. The NGS test showed high reproducibility and accuracy of >99%. The test provided relevant clinical information for SOC treatment as well as more information related to investigational options and clinical trials for >95% of advanced-stage patients. In conclusion, the SA test comprising a robust and accurate NGS assay combined with clinically relevant IHC tests can detect somatic changes of clinical significance for strategic cancer management in all the stages.

  5. Constitutive modeling of contact angle hysteresis.

    PubMed

    Vedantam, Srikanth; Panchagnula, Mahesh V

    2008-05-15

    We introduce a phase field model of wetting of surfaces by sessile drops. The theory uses a two-dimensional non-conserved phase field variable to parametrize the Gibbs free energy of the three-dimensional system. Contact line tension and contact angle hysteresis arise from the gradient term in the free energy and the kinetic coefficient respectively. A significant advantage of this approach is in the constitutive specification of hysteresis. The advancing and receding angles of a surface, the liquid-vapor interfacial energy and three-phase line tension are the only required constitutive inputs to the model. We first simulate hysteresis on a smooth chemically homogeneous surface using this theory. Next we show that it is possible to study heterogeneous surfaces whose component surfaces are themselves hysteretic. We use this theory to examine the wetting of a surface containing a circular heterogeneous island. The contact angle for this case is found to be determined solely by the material properties at the contact line in accord with recent experimental data.

  6. Comparison of outcomes of tyrosine kinase inhibitor in first- or second-line therapy for advanced non-small-cell lung cancer patients with sensitive EGFR mutations.

    PubMed

    Xu, Jianlin; Zhang, Xueyan; Yang, Haitang; Ding, Guozheng; Jin, Bo; Lou, Yuqing; Zhang, Yanwei; Wang, Huimin; Han, Baohui

    2016-10-18

    Direct comparisons between the use of first- and second-line EGFR tyrosine kinase inhibitor (TKI) in patients with sensitive EGFR mutations are limited. A total of 264 advanced non-small-cell lung cancer (NSCLC) patients with sensitive mutations received EGFR TKI therapy as the first-line therapy, and a total of 187 patients received TKI as the second-line therapy at Shanghai Chest Hospital. First-line EGFR TKI therapy [12.9 months, 95% confidence interval (CI), 10.7-15.2] provided longer progression-free survival (PFS) than did second-line EGFR TKI therapy (9.0 months, 95% CI, 7.7-10.2) [hazard ratio (HR): 0.78, P = 0.034]. The objective response rate (ORR) of first-, and second-line TKI therapy were 67.8% (159/233) and 55.6% (94/169), respectively (P = 0.001). The overall survival (OS) for patients (n = 141) receiving first-line TKI followed by second-line chemotherapy were longer than those for patients (n = 187) receiving first-line chemotherapy followed by second-line TKI (HR: 0.69, P = 0.02).Compared with second-line TKI, first-line therapy achieved a significant and longer PFS, and higher ORR in the sensitive EGFR mutated NSCLC patients. The therapeutic strategy of using TKI followed by chemotherapy achieved longer OS than that using chemotherapy followed by TKI.

  7. Budget impact analysis of first-line treatment with pazopanib for advanced renal cell carcinoma in Spain

    PubMed Central

    2013-01-01

    Background Due to economic constraints, cancer therapies are under close scrutiny by clinicians, pharmacists and payers alike. There is no published pharmacoeconomic evidence guiding the choice of first-line therapy for advanced renal cell carcinoma (RCC) in the Spanish setting. We aimed to develop a model describing the natural history of RCC that can be used in healthcare decision-making. We particularly analyzed the budget impact associated with the introduction of pazopanib compared to sunitinib under the Spanish National Healthcare System (NHS) perspective. Methods We developed a Markov model to estimate the future number of cases of advanced RCC (patients with favorable or intermediate risk) resulting either from initial diagnosis or disease progression after surgery. The model parameters were obtained from the literature. We assumed that patients would receive either pazopanib or sunitinib as first-line therapy until disease progression. Pharmacological costs and costs associated with the management of adverse events (AE) were considered. A univariate sensitivity analysis was undertaken in order to test the robustness of the results. Results The model predicted an adult RCC prevalence of 7.5/100,000 (1-year), 20.7/100,000 (3-year) and 32.5/100,000 (5-year). These figures are very close to GLOBOCAN reported RCC prevalence estimates of 7.6/100,000, 20.2/100,000 and 31.1/100,000, respectively. The model predicts 1,591 advanced RCC patients with favorable or intermediate risk in Spain in 2013. Annual per patient pharmacological costs were €32,365 and €39,232 with pazopanib and sunitinib, respectively. Annual costs associated with the management of AE were €662 and €974, respectively. Overall annual per patient costs were €7,179 (18%) lower with pazopanib compared to sunitinib. For every point increase in the percentage of patients treated with pazopanib, the NHS would save €67,236. If all the 1,591 patients predicted were treated with pazopanib, the

  8. Real-world treatment patterns for patients receiving second-line and third-line treatment for advanced non-small cell lung cancer: A systematic review of recently published studies.

    PubMed

    Davies, Jessica; Patel, Manali; Gridelli, Cesare; de Marinis, Filippo; Waterkamp, Daniel; McCusker, Margaret E

    2017-01-01

    Most patients with advanced non-small cell lung cancer (NSCLC) have a poor prognosis and receive limited benefit from conventional treatments, especially in later lines of therapy. In recent years, several novel therapies have been approved for second- and third-line treatment of advanced NSCLC. In light of these approvals, it is valuable to understand the uptake of these new treatments in routine clinical practice and their impact on patient care. A systematic literature search was conducted in multiple scientific databases to identify observational cohort studies published between January 2010 and March 2017 that described second- or third-line treatment patterns and clinical outcomes in patients with advanced NSCLC. A qualitative data synthesis was performed because a meta-analysis was not possible due to the heterogeneity of the study populations. A total of 12 different study cohorts in 15 articles were identified. In these cohorts, single-agent chemotherapy was the most commonly administered treatment in both the second- and third-line settings. In the 5 studies that described survival from the time of second-line treatment initiation, median overall survival ranged from 4.6 months (95% CI, 3.8-5.7) to 12.8 months (95% CI, 10.7-14.5). There was limited information on the use of biomarker-directed therapy in these patient populations. This systematic literature review offers insights into the adoption of novel therapies into routine clinical practice for second- and third-line treatment of patients with advanced NSCLC. This information provides a valuable real-world context for the impact of recently approved treatments for advanced NSCLC.

  9. Fractionate analysis of the phytochemical composition and antioxidant activities in advanced breeding lines of high-lycopene tomatoes.

    PubMed

    Ilahy, Riadh; Piro, Gabriella; Tlili, Imen; Riahi, Anissa; Sihem, Rabaoui; Ouerghi, Imen; Hdider, Chafik; Lenucci, Marcello Salvatore

    2016-01-01

    This study investigates the antioxidant components [lycopene, total phenolics, total flavonoids, ascorbic acid (AsA) and dehydroascorbic acid (DHA)] as well as antioxidant activities of the hydrophilic and lipophilic fractions (AAHF and AALF) of peel, pulp and seed fractions isolated from red-ripe berries of the ordinary tomato cultivar Rio Grande and the two high-lycopene tomato breeding lines HLT-F61 and HLT-F62 simultaneously grown in an open-field of Northern Tunisia. Significant differences (p < 0.05) were found among cultivars for each trait studied. All fractions isolated from the red-ripe berries of HLT lines showed higher lycopene, total phenolics and total flavonoid contents, as well as higher AAHF and AALF, than those isolated from Rio Grande. Regardless of the fraction, HLT-F61 had the highest lycopene content (893.0 mg per kg fw, 280.0 mg per kg fw, and 47.5 mg per kg fw in peel, pulp and seed fractions, respectively) and total phenolics at least 2-fold and 3-fold higher than HLT-F62 and Rio Grande, respectively. Peel and seed fractions from HLT-F61 red-ripe tomato berries had the highest AsA content (345 mg per kg fw and 115 mg per kg fw, respectively), while no significant difference was found in the seed fraction between HLT-F62 and Rio Grande. The HLT-F62 pulp fraction showed the highest content of AsA (186 mg per kg fw) and DHA (151 mg per kg fw) among all the assayed cultivars. Except for the peel fraction, where HLT-F61 had similar AAHF values to HLT-F62, the high-lycopene line HLT-F61 showed higher AAHF values than HLT-F62 and Rio Grande. Regardless of the fraction, the highest AALF values were recorded in HLT-F61 berries. Thus, both HLT tomato lines are promising for the introduction, as advanced hybrids, in either fresh market or processing industry.

  10. A fast-time-response extreme ultraviolet spectrometer for measurement of impurity line emissions in the Experimental Advanced Superconducting Tokamak

    SciTech Connect

    Zhang, Ling; Xu, Zong; Wu, Zhenwei; Zhang, Pengfei; Wu, Chengrui; Gao, Wei; Shen, Junsong; Chen, Yingjie; Liu, Xiang; Wang, Yumin; Gong, Xianzu; Hu, Liqun; Chen, Junlin; Zhang, Xiaodong; Wan, Baonian; Li, Jiangang; Morita, Shigeru; Ohishi, Tetsutarou; Goto, Motoshi; Dong, Chunfeng; and others

    2015-12-15

    A flat-field extreme ultraviolet (EUV) spectrometer working in the 20-500 Å wavelength range with fast time response has been newly developed to measure line emissions from highly ionized tungsten in the Experimental Advanced Superconducting Tokamak (EAST) with a tungsten divertor, while the monitoring of light and medium impurities is also an aim in the present development. A flat-field focal plane for spectral image detection is made by a laminar-type varied-line-spacing concave holographic grating with an angle of incidence of 87°. A back-illuminated charge-coupled device (CCD) with a total size of 26.6 × 6.6 mm{sup 2} and pixel numbers of 1024 × 255 (26 × 26 μm{sup 2}/pixel) is used for recording the focal image of spectral lines. An excellent spectral resolution of Δλ{sub 0} = 3-4 pixels, where Δλ{sub 0} is defined as full width at the foot position of a spectral line, is obtained at the 80-400 Å wavelength range after careful adjustment of the grating and CCD positions. The high signal readout rate of the CCD can improve the temporal resolution of time-resolved spectra when the CCD is operated in the full vertical binning mode. It is usually operated at 5 ms per frame. If the vertical size of the CCD is reduced with a narrow slit, the time response becomes faster. The high-time response in the spectral measurement therefore makes possible a variety of spectroscopic studies, e.g., impurity behavior in long pulse discharges with edge-localized mode bursts. An absolute intensity calibration of the EUV spectrometer is also carried out with a technique using the EUV bremsstrahlung continuum at 20-150 Å for quantitative data analysis. Thus, the high-time resolution tungsten spectra have been successfully observed with good spectral resolution using the present EUV spectrometer system. Typical tungsten spectra in the EUV wavelength range observed from EAST discharges are presented with absolute intensity and spectral identification.

  11. A fast-time-response extreme ultraviolet spectrometer for measurement of impurity line emissions in the Experimental Advanced Superconducting Tokamak.

    PubMed

    Zhang, Ling; Morita, Shigeru; Xu, Zong; Wu, Zhenwei; Zhang, Pengfei; Wu, Chengrui; Gao, Wei; Ohishi, Tetsutarou; Goto, Motoshi; Shen, Junsong; Chen, Yingjie; Liu, Xiang; Wang, Yumin; Dong, Chunfeng; Zhang, Hongmin; Huang, Xianli; Gong, Xianzu; Hu, Liqun; Chen, Junlin; Zhang, Xiaodong; Wan, Baonian; Li, Jiangang

    2015-12-01

    A flat-field extreme ultraviolet (EUV) spectrometer working in the 20-500 Å wavelength range with fast time response has been newly developed to measure line emissions from highly ionized tungsten in the Experimental Advanced Superconducting Tokamak (EAST) with a tungsten divertor, while the monitoring of light and medium impurities is also an aim in the present development. A flat-field focal plane for spectral image detection is made by a laminar-type varied-line-spacing concave holographic grating with an angle of incidence of 87°. A back-illuminated charge-coupled device (CCD) with a total size of 26.6 × 6.6 mm(2) and pixel numbers of 1024 × 255 (26 × 26 μm(2)/pixel) is used for recording the focal image of spectral lines. An excellent spectral resolution of Δλ0 = 3-4 pixels, where Δλ0 is defined as full width at the foot position of a spectral line, is obtained at the 80-400 Å wavelength range after careful adjustment of the grating and CCD positions. The high signal readout rate of the CCD can improve the temporal resolution of time-resolved spectra when the CCD is operated in the full vertical binning mode. It is usually operated at 5 ms per frame. If the vertical size of the CCD is reduced with a narrow slit, the time response becomes faster. The high-time response in the spectral measurement therefore makes possible a variety of spectroscopic studies, e.g., impurity behavior in long pulse discharges with edge-localized mode bursts. An absolute intensity calibration of the EUV spectrometer is also carried out with a technique using the EUV bremsstrahlung continuum at 20-150 Å for quantitative data analysis. Thus, the high-time resolution tungsten spectra have been successfully observed with good spectral resolution using the present EUV spectrometer system. Typical tungsten spectra in the EUV wavelength range observed from EAST discharges are presented with absolute intensity and spectral identification.

  12. Allergic contact dermatitis in children.

    PubMed

    Fontana, E; Belloni Fortina, A

    2014-12-01

    Allergic contact dermatitis is an inflammatory skin disease (delayed type hypersensitivity reaction) that accounts for up to 20% of all childhood dermatitis. Allergic contact dermatitis represents a clinical manifestation of contact sensitization and usually occurs at skin sites that have come into contact with the allergen. The clinical features of allergic contact dermatitis are itchy eczematous lesions. Prevalence of contact sensitization varies between 27% and 96% of children with suspected contact dermatitis. The relationship between contact sensitization and atopic dermatitis has been widely discussed but only conflicting data have been reported. Epicutaneous patch testing is the gold standard for the diagnosis of allergic contact dermatitis. The most common allergens detected in children are: metals, topical medicaments, fragrances, and preservatives. The first line management of allergic contact dermatitis in children is to avoid the offending allergens identified with the patch test and a topical corticosteroid therapy.

  13. Contact Dermatitis

    MedlinePlus

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  14. The impact of contact

    NASA Astrophysics Data System (ADS)

    Finney, B.

    1986-10-01

    Scenarios of the impact on human society of radio contact with an extraterrestrial civilization are presented. Some believe that contact with advanced extraterrestrials would quickly devastate the human spirit, while others believe that these super-intelligent beings would show the inhabitants of the earth how to live in peace. It is proposed that the possible existence of extraterrestrial civilizations and the development of means of studying and communicating with them need to be considered.

  15. Fluoropyrimidine-Based Chemotherapy as First-Line Treatment for Advanced Gastric Cancer: a Bayesian Network Meta-Analysis.

    PubMed

    Zhu, Lucheng; Liu, Jihong; Ma, Shenglin

    2016-10-01

    Fluoropyrimidine-based regimens are the most common treatments in advanced gastric cancer. We used a Bayesian network meta-analysis to identify the optimal fluoropyrimidine-based chemotherapy by comparing their relative efficacy and safety. We systematically searched databases and extracted data from randomized controlled trials, which compared fluoropyrimidine-based regimens as first-line treatment in AGC. The main outcomes were overall survival (OS), progression-free survival (PFS), overall response rate (ORR), and grade 3 or 4 adverse events (AEs). A total of 12 RCTs of 4026 patients were included in our network meta-analysis. Pooled analysis showed S-1 and capecitabine had a significant OS benefit over 5-Fu, with hazard ratios of 0.90 (95%CI = 0.81-0.99) and 0.88 (95%CI = 0.80-0.96), respectively. The result also exhibited a trend that S-1 and capecitabine prolonged PFS in contrast to 5-Fu, with hazard ratios of 0.84 (95%CI = 0.66-1.02) and 0.84 (95%CI = 0.65-1.03), respectively. Additionally, all the three fluoropyrimidine-based regimens were similar in terms of ORR and grade 3 or 4 AEs. Compared with regimens based on 5-Fu, regimens based on S-1 or capecitabine demonstrated a significant OS improvement without compromise of AEs as first-line treatment in AGC in Asian population. S-1 and capecitabine can be interchangeable according their different emphasis on AEs.

  16. Telocyte's contacts.

    PubMed

    Faussone-Pellegrini, Maria-Simonetta; Gherghiceanu, Mihaela

    2016-07-01

    Telocytes (TC) are an interstitial cell type located in the connective tissue of many organs of humans and laboratory mammals. By means of homocellular contacts, TC build a scaffold whose meshes integrity and continuity are guaranteed by those contacts having a mechanical function; those contacts acting as sites of intercellular communication allow exchanging information and spreading signals. Heterocellular contacts between TC and a great variety of cell types give origin to mixed networks. TC, by means of all these types of contacts, their interaction with the extracellular matrix and their vicinity to nerve endings, are part of an integrated system playing tissue/organ-specific roles.

  17. Dynamic contact angle analysis of silicone hydrogel contact lenses.

    PubMed

    Read, Michael Leonard; Morgan, Philip Bruce; Kelly, Jeremiah Michael; Maldonado-Codina, Carole

    2011-07-01

    Contact angle measurements are used to infer the clinical wetting characteristics of contact lenses. Such characterization has become more commonplace since the introduction of silicone hydrogel contact lens materials, which have been associated with reduced in vivo wetting due to the inclusion of siloxane-containing components. Using consistent methodology and a single investigator, advancing and receding contact angles were measured for 11 commercially available silicone hydrogel contact lens types with a dynamic captive bubble technique employing customized, fully automated image analysis. Advancing contact angles were found to range between 20° and 72° with the lenses falling into six statistically discrete groupings. Receding contact angles fell within a narrower range, between 17° and 22°, with the lenses segregated into three groups. The relationship between these laboratory measurements and the clinical performance of the lenses requires further investigation.

  18. Contact-angle hysteresis on periodic microtextured surfaces: Strongly corrugated liquid interfaces.

    PubMed

    Iliev, Stanimir; Pesheva, Nina

    2016-06-01

    We study numerically the shapes of a liquid meniscus in contact with ultrahydrophobic pillar surfaces in Cassie's wetting regime, when the surface is covered with identical and periodically distributed micropillars. Using the full capillary model we obtain the advancing and the receding equilibrium meniscus shapes when the cross-sections of the pillars are both of square and circular shapes, for a broad interval of pillar concentrations. The bending of the liquid interface in the area between the pillars is studied in the framework of the full capillary model and compared to the results of the heterogeneous approximation model. The contact angle hysteresis is obtained when the three-phase contact line is located on one row (block case) or several rows (kink case) of pillars. It is found that the contact angle hysteresis is proportional to the line fraction of the contact line on pillars tops in the block case and to the surface fraction for pillar concentrations 0.1-0.5 in the kink case. The contact angle hysteresis does not depend on the shape (circular or square) of the pillars cross-section. The expression for the proportionality of the receding contact angle to the line fraction [Raj et al., Langmuir 28, 15777 (2012)LANGD50743-746310.1021/la303070s] in the case of block depinning is theoretically substantiated through the capillary force, acting on the solid plate at the meniscus contact line.

  19. Contact-angle hysteresis on periodic microtextured surfaces: Strongly corrugated liquid interfaces

    NASA Astrophysics Data System (ADS)

    Iliev, Stanimir; Pesheva, Nina

    2016-06-01

    We study numerically the shapes of a liquid meniscus in contact with ultrahydrophobic pillar surfaces in Cassie's wetting regime, when the surface is covered with identical and periodically distributed micropillars. Using the full capillary model we obtain the advancing and the receding equilibrium meniscus shapes when the cross-sections of the pillars are both of square and circular shapes, for a broad interval of pillar concentrations. The bending of the liquid interface in the area between the pillars is studied in the framework of the full capillary model and compared to the results of the heterogeneous approximation model. The contact angle hysteresis is obtained when the three-phase contact line is located on one row (block case) or several rows (kink case) of pillars. It is found that the contact angle hysteresis is proportional to the line fraction of the contact line on pillars tops in the block case and to the surface fraction for pillar concentrations 0.1 -0.5 in the kink case. The contact angle hysteresis does not depend on the shape (circular or square) of the pillars cross-section. The expression for the proportionality of the receding contact angle to the line fraction [Raj et al., Langmuir 28, 15777 (2012), 10.1021/la303070s] in the case of block depinning is theoretically substantiated through the capillary force, acting on the solid plate at the meniscus contact line.

  20. A retrospective analysis of efficacy and safety of adding bevacizumab to chemotherapy as first- and second-line therapy in advanced non-small-cell lung cancer (NSCLC).

    PubMed

    Quan, Rencui; Huang, Jiaxing; Chen, Nan; Fang, Wenfeng; Hu, Zhihuang; Zhan, Jianhua; Zhou, Ting; Zhang, Li; Zhang, Hongyu

    2016-08-01

    Several phase III clinical trials had authenticated that the addition of bevacizumab to paclitaxel plus carboplatin or gemcitabine plus cisplatin showed encouraging efficacy as first-line therapy for advanced NSCLC patients. However, the benefits of adding bevacizumab to other chemotherapy regimens in first- or second-line therapy have not been reported. To compare the clinical efficacy and safety of bevacizumab concomitant with chemotherapy regimens in patients with advanced NSCLC as first- or second-line therapy, we retrospectively reviewed the effects of adding bevacizumab to chemotherapy regimens in naive-chemotherapy and pre-chemotherapy patients with advanced non-squamous NSCLC. A total of 79 patients with advanced non-squamous NSCLC received at least two cycles of bevacizumab with chemotherapy between October 2010 and December 2013 were selected. Our primary end points were overall response rate (ORR) and disease control rate (DCR). The secondary objective was overall survival (OS) and safety. Seventy-nine patients were included in this study. Overall response rates at first evaluation (after 2 cycles) were 23.1 % (9/39) and 5.0 % (2/40) in first- and second-line therapy (P = 0.020), respectively. And disease control rates were 84.6 % (33/39) and 50 % (20/40), respectively (P = 0.001). The median OS were 27.2 months (95 % CI 13.3-41.1 months) and 29.6 months (95 % CI 6.7-52.5 months), respectively (P = 0.740). Grade 3-4 adverse events included leukopenia (2/39), and neutropenia (3/39) in first-line therapy versus neutropenia (1/40) and thrombocytopenia (2/40) in second-line treatment. In our experience, combination of bevacizumab and chemotherapy had encouraging anti-tumor efficacy as both first- and second-line therapy.

  1. Diminution of contact angle hysteresis under the influence of an oscillating force.

    PubMed

    Manor, Ofer

    2014-06-17

    We suggest a simple quantitative model for the diminution of contact angle hysteresis under the influence of an oscillatory force invoked by thermal fluctuations, substrate vibrations, acoustic waves, or oscillating electric fields. Employing force balance rather than the usual description of contact angle hysteresis in terms of Gibbs energy, we highlight that a wetting system, such as a sessile drop or a bubble adhered to a solid substrate, appears at long times to be partially or fully independent of contact angle hysteresis and thus independent of static friction forces, as a result of contact line pinning. We verify this theory by studying several well-known experimental observations such as the approach of an arbitrary contact angle toward the Young contact angle and the apparent decrease (or increase) in an advancing (or a receding) contact angle under the influence of an external oscillating force.

  2. Advanced glycation endproducts increase proliferation, migration and invasion of the breast cancer cell line MDA-MB-231.

    PubMed

    Sharaf, Hana; Matou-Nasri, Sabine; Wang, Qiuyu; Rabhan, Zaki; Al-Eidi, Hamad; Al Abdulrahman, Abdulkareem; Ahmed, Nessar

    2015-03-01

    Diabetic patients have increased likelihood of developing breast cancer. Advanced glycation endproducts (AGEs) underlie the pathogenesis of diabetic complications but their impact on breast cancer cells is not understood. This study aims to determine the effects of methylglyoxal-derived bovine serum albumin AGEs (MG-BSA-AGEs) on the invasive MDA-MB-231 breast cancer cell line. By performing cell counting, using wound-healing assay, invasion assay and zymography analysis, we found that MG-BSA-AGEs increased MDA-MB-231 cell proliferation, migration and invasion through Matrigel™ associated with an enhancement of matrix metalloproteinase (MMP)-9 activities, in a dose-dependent manner. Using Western blot and flow cytometry analyses, we demonstrated that MG-BSA-AGEs increased expression of the receptor for AGEs (RAGE) and phosphorylation of key signaling protein extracellular signal-regulated kinase (ERK)-1/2. Furthermore, in MG-BSA-AGE-treated cells, phospho-protein micro-array analysis revealed enhancement of phosphorylation of the ribosomal protein 70 serine S6 kinase beta 1 (p70S6K1), which is known to be involved in protein synthesis, the signal transducer and activator of transcription (STAT)-3 and the mitogen-activated protein kinase (MAPK) p38, which are involved in cell survival. Blockade of MG-BSA-AGE/RAGE interactions using a neutralizing anti-RAGE antibody inhibited MG-BSA-AGE-induced MDA-MB-231 cell processes, including the activation of signaling pathways. Throughout the study, non-modified BSA had a negligible effect. In conclusion, AGEs might contribute to breast cancer development and progression partially through the regulation of MMP-9 activity and RAGE signal activation. The up-regulation of RAGE and the concomitant increased phosphorylation of p70S6K1 induced by AGEs may represent promising targets for drug therapy to treat diabetic patients with breast cancer.

  3. Second-line ramucirumab therapy for advanced hepatocellular carcinoma (REACH): an East Asian and non-East Asian subgroup analysis

    PubMed Central

    Park, Joon Oh; Ryoo, Baek-Yeol; Yen, Chia-Jui; Kudo, Masatoshi; Yang, Ling; Abada, Paolo B.; Cheng, Rebecca; Orlando, Mauro; Zhu, Andrew X.; Okusaka, Takuji

    2016-01-01

    Purpose REACH investigated second-line ramucirumab therapy for advanced hepatocellular carcinoma. Results Median overall survival was 8.2 months for ramucirumab and 6.9 months for placebo (HR, 0.835; 95% CI, 0.634–1.100; p = 0.2046) for East Asians, and 10.1 months for ramucirumab and 8.0 months for placebo (HR, 0.895; 95% CI, 0.690–1.161; p = 0.4023) for non-East Asians. Median overall survival in patients with baseline alpha-fetoprotein ≥ 400 ng/mL was 7.8 months for ramucirumab and 4.2 months for placebo (HR, 0.749; 95% CI, 0.519–1.082; p = 0.1213) for East Asians (n = 139), and 8.2 months for ramucirumab and 4.5 months for placebo (HR, 0.579; 95% CI, 0.371–0.904; p = 0.0149) for non-East Asians (n = 111). The most common grade ≥ 3 treatment-emergent adverse events in East Asians and non-East Asians included hypertension and malignant neoplasm progression. Materials and methods A post-hoc analysis of East Asians (N = 252) and non-East Asians (N = 313) in the intent-to-treat population was performed. Conclusions In East Asians and non-East Asians, ramucirumab did not significantly prolong overall survival. In patients with baseline alpha-fetoprotein ≥ 400 ng/mL, a potentially larger survival benefit was observed in both subgroups. Safety for East Asians was similar to non-East Asians. PMID:27776351

  4. Drop impact on soft surfaces: beyond the static contact angles.

    PubMed

    Rioboo, Romain; Voué, Michel; Adão, Helena; Conti, Joséphine; Vaillant, Alexandre; Seveno, David; De Coninck, Joël

    2010-04-06

    The wettability of cross-linked poly(dimethylsiloxane) elastomer films and of octadecyltrichlorosilane self-assembled monolayers with water has been measured and compared using various methods. Contact angle hysteresis values were compared with values reported in the literature. A new method to characterize advancing, receding contact angles, and hysteresis using drop impact have been tested and compared with usual methods. It has been found that for the rigid surfaces the drop impact method is comparable with other methods but that for elastomer surfaces the hysteresis is function of the drop impact velocity which influences the extent of the deformation of the soft surface at the triple line.

  5. P11: 18FDG-PET/CT for early prediction of response to first line platinum chemotherapy in advanced thymic epithelial tumors

    PubMed Central

    Palmieri, Giovannella; Ottaviano, Margaret; Del Vecchio, Silvana; Segreto, Sabrina; Tucci, Irene; Damiano, Vincenzo

    2015-01-01

    Background To investigate the value of the metabolic tumor response assessed with 18F-fluorodeoxyglucose positron emission tomography (FDG-PET), compared with clinicobiological markers, to predict the response disease to first line platinum based chemotherapy in advanced thymic epithelial tumors (TETs). Methods Twenty patients with diagnosis of TET and stage of disease III and IV sec, Masaoka-Koga, were retrospectively included in this monocentric study. Different pre-treatment clinical, biological and pathological parameters, including histotype sec, WHO 2004 and stage of disease sec, Masaoka-Koga were assessed. Tumor glucose metabolism at baseline and its change after the first line platinum based chemotherapy (from 4 to 6 cycles) were assessed using FDG-PET, moreover the response disease was assessed using total body CT scan for the evaluation of RECIST criteria 1.1. Results Twelve patients had an objective response to the first line platinum based chemotherapy according RECIST criteria 1.1 and all of them started with a SUVmax at baseline major than 5, indeed the other eight patients, non-responders to chemotherapy, had a SUVmax at baseline minor than 5. Conclusions It is important to define the chemosensitivity of advanced TETs early. Combining bio-pathological parameters with the metabolism at baseline assessed with FDG-PET can help the physician to early predict the probability of obtaining a disease response to first line platinum based chemotherapy. The SUVmax cut off of 5 at 18FDG-PET/CT performed at baseline treatment might be a new parameter for choosing the most powerful first line of chemotherapy. Given these results, further prospective studies are needed to establish a new first line therapy in advanced TETs with a low SUVmax at baseline, non-responders to conventional chemotherapy.

  6. Jet outflow and open field line measurements on the C-2U advanced beam-driven field-reversed configuration plasma experiment

    NASA Astrophysics Data System (ADS)

    Sheftman, D.; Gupta, D.; Roche, T.; Thompson, M. C.; Giammanco, F.; Conti, F.; Marsili, P.; Moreno, C. D.

    2016-11-01

    Knowledge and control of the axial outflow of plasma particles and energy along open-magnetic-field lines are of crucial importance to the stability and longevity of the advanced beam-driven field-reversed configuration plasma. An overview of the diagnostic methods used to perform measurements on the open field line plasma on C-2U is presented, including passive Doppler impurity spectroscopy, microwave interferometry, and triple Langmuir probe measurements. Results of these measurements provide the jet ion temperature and axial velocity, electron density, and high frequency density fluctuations.

  7. Cost Effectiveness of First-Line Treatment with Doxorubicin/Ifosfamide Compared to Trabectedin Monotherapy in the Management of Advanced Soft Tissue Sarcoma in Italy, Spain, and Sweden

    PubMed Central

    Guest, Julian F.; Sladkevicius, Erikas; Gough, Nicholas

    2013-01-01

    Background. Doxorubicin/ifosfamide is a first-line systemic chemotherapy for the majority of advanced soft tissue sarcoma (ASTS) subtypes. Trabectedin is indicated for the treatment of ASTS after failure of anthracyclines and/or ifosfamide; however it is being increasingly used off-label as a first-line treatment. This study estimated the cost effectiveness of these two treatments in the first-line management of ASTS in Italy, Spain, and Sweden. Methods. A Markov model was constructed to estimate the cost effectiveness of doxorubicin/ifosfamide compared to trabectedin monotherapy, defined as the cost per QALY gained, in each country. Results. First-line treatment with doxorubicin/ifosfamide resulted in lower two-year healthcare costs and more QALYs than first-line treatment with trabectedin monotherapy in all three countries. Probabilistic sensitivity analysis showed that at a cost per QALY threshold of €35,000, >90% of a cohort would be cost effectively treated with doxorubicin/ifosfamide compared to trabectedin monotherapy in all three countries. Conclusion. Within the model's limitations, first-line treatment of patients with ASTS with doxorubicin/ifosfamide instead of trabectedin monotherapy affords a cost-effective use of publicly funded healthcare resources in Italy, Spain, and Sweden and is therefore the preferred treatment in all three countries. These findings support the recommendation that trabectedin should remain a second-line treatment. PMID:24302852

  8. Neutropenia as a prognostic factor and safety of second-line therapy with S-1 for advanced or recurrent pancreatic cancer.

    PubMed

    Ikagawa, Makiko; Kimura, Michio; Iwai, Mina; Usami, Eiseki; Yoshimura, Tomoaki; Yasuda, Kimio

    2016-09-01

    The aim of this retrospective study was to investigate the safety of S-1 as second-line therapy and to evaluate the association between neutropenia occurring during first-line gemcitabine (GEM) therapy and survival for advanced or recurrent pancreatic cancer (APC). Between January, 2010 and December, 2014, 123 APC patients received chemotherapy at the Ogaki Municipal Hospital (Ogaki, Japan). Of those, 37 received GEM as first-line and S-1 as a second-line therapy (GEM→S-1 group). A further 60 patients received GEM as first-line therapy, but did not receive second-line therapy (GEM group). The median overall survival in the GEM→S-1 (n=37) and GEM (n=60) groups was 323 days [95% confidence interval (CI): 138-218.9 days] and 172 days (95% CI: 105-184.4 days), respectively (P=0.0004). The median overall survival in the mild (grade ≤2; n=63) and severe (grade ≥3; n=34) neutropenia groups was 178 days (95% CI: 182-275 days) and 330 days (95% CI: 297-514 days), respectively (log-rank test, P=0.0023). The severe non-haematological toxicities associated with S-1 as second-line therapy were nausea (2.7%) and hand-foot syndrome (2.7%). Second-line S-1 treatment was discontinued due to adverse events in 5.4% (2/37) of the cases. In conclusion, neutropenia occurring during GEM therapy administered as first-line treatment to APC patients was strongly associated with a better prognosis. S-1 therapy as second-line treatment was associated with a low incidence of severe adverse events and the patients were able to successfully continue treatment.

  9. Ohmic Contacts to Semiconducting Diamond

    DTIC Science & Technology

    1990-10-01

    after approxi- mately 30 minutes. Analysis using Auger electron spectroscopy, scanning electron microscopy, and x-ray diffraction established the...adherent wire bonds. To test the contacts for bondability, 10-mil gold wires were bonded to the contacts by using an ultrasonic ball bonder. Pull-to...resistance of the ohmic contacts (reference 4). We have chosen to use the circular transmission line geometry and analysis first proposed by Reeves

  10. Advanced bladder cancer: status of first-line chemotherapy and the search for active agents in the second-line setting.

    PubMed

    Gallagher, David J; Milowsky, Matthew I; Bajorin, Dean F

    2008-09-15

    Urothelial carcinoma (UC) remains a significant health problem affecting an estimated 68,810 people in 2008 alone in the US. The majority of patients with metastatic disease develop disease recurrence, and long-term survival rates are poor. There is no standard of care for the treatment of patients with UC after the failure of cisplatin-based regimens in the first-line setting. Efforts to improve second-line treatment have led to the evaluation of single agents such as vinflunine and pemetrexed, and multidrug combinations with cytotoxic and targeted agents, including trastuzumab and bevacizumab. The authors reviewed the activity of several single agents and combination regimens in patients with UC. Emerging strategies for the measurement of response in clinical trials were also outlined.

  11. Paclitaxel plus cisplatin vs. 5-fluorouracil plus cisplatin as first-line treatment for patients with advanced squamous cell esophageal cancer.

    PubMed

    Liu, Ying; Ren, Zhonghai; Yuan, Long; Xu, Shuning; Yao, Zhihua; Qiao, Lei; Li, Ke

    2016-01-01

    Paclitaxel plus cisplatin and 5-fluorouracil plus cisplatin treatments are effective strategies for patients with advanced esophageal squamous cell carcinoma. This study was to evaluate the safety and efficacy of paclitaxel plus cisplatin and 5-fluorouracil plus cisplatin as first-line chemotherapy for patients with advanced esophageal squamous cell carcinoma. A total of 398 patients with advanced esophageal squamous cell carcinoma who received chemotherapy were included and divided into 2 groups: paclitaxel plus cisplatin group and 5-fluorouracil plus cisplatin group. 195 patients received paclitaxel plus cisplatin and 203 patients received 5-fluorouracil plus cisplatin. The objective response rates were 42.5% and 38.4% for paclitaxel plus cisplatin group and 5-fluorouracil plus cisplatin group, respectively (P=0.948). The median progression-free survival was 7.85 months (95% CI, 6.77-8.94 months) for the paclitaxel plus cisplatin group and 6.53 months (95% CI, 5.63-7.43 months) for the 5-fluorouracil plus cisplatin group with significant difference (P=0.02). The median overall survival was 13.46 months (95% CI, 12.01-14.91 months) for the paclitaxel plus cisplatin group and 12.67 months (95% CI, 11.87-13.47 months) for the 5-fluorouracil plus cisplatin group (P=0.204). The first-line chemotherapy of paclitaxel plus cisplatin had better median progression-free survival than 5-fluorouracil plus cisplatin in patients with advanced esophageal squamous cell carcinoma with tolerable toxicities.

  12. Advanced mask technique to improve bit line CD uniformity of 90 nm node flash memory in low-k1 lithography

    NASA Astrophysics Data System (ADS)

    Kim, Jong-doo; Choi, Jae-young; Kim, Jea-hee; Han, Jae-won

    2008-10-01

    As devices size move toward 90nm technology node or below, defining uniform bit line CD of flash devices is one of the most challenging features to print in KrF lithography. There are two principal difficulties in defining bit line on wafer. One is insufficient process margin besides poor resolution compared with ArF lithography. The other is that asymmetric bit line should be made for OPC(Optical Proximity Correction) modeling. Therefore advanced ArF lithography scanner should be used for define bit line with RETs (Resolution Enhancement Techniques) such as immersion lithography, OPC, PSM(Phase Shift Mask), high NA(Numerical Aperture), OAI(Off-Axis Illumination), SRAF(Sub-resolution Assistant Feature), and mask biasing.. Like this, ArF lithography propose the method of enhancing resolution, however, we must spend an enormous amount of CoC(cost of ownership) to utilize ArF photolithography process than KrF. In this paper, we suggest method to improve of bit line CD uniformity, patterned by KrF lithographic process in 90nm sFlash(stand alone Flash) devices. We applied new scheme of mask manufacturing, which is able to realize 2 different types of mask, binary and phase-shift, into one plate. Finally, we could get the more uniform bit lines and we expect to get more stable properties then before applying this technique.

  13. Diffuse interface modeling of three-phase contact line dynamics on curved boundaries: A lattice Boltzmann model for large density and viscosity ratios

    NASA Astrophysics Data System (ADS)

    Fakhari, Abbas; Bolster, Diogo

    2017-04-01

    We introduce a simple and efficient lattice Boltzmann method for immiscible multiphase flows, capable of handling large density and viscosity contrasts. The model is based on a diffuse-interface phase-field approach. Within this context we propose a new algorithm for specifying the three-phase contact angle on curved boundaries within the framework of structured Cartesian grids. The proposed method has superior computational accuracy compared with the common approach of approximating curved boundaries with stair cases. We test the model by applying it to four benchmark problems: (i) wetting and dewetting of a droplet on a flat surface and (ii) on a cylindrical surface, (iii) multiphase flow past a circular cylinder at an intermediate Reynolds number, and (iv) a droplet falling on hydrophilic and superhydrophobic circular cylinders under differing conditions. Where available, our results show good agreement with analytical solutions and/or existing experimental data, highlighting strengths of this new approach.

  14. Advances in first-line treatment of chronic lymphocytic leukemia: current recommendations on management and first-line treatment by the German CLL Study Group (GCLLSG).

    PubMed

    Cramer, Paula; Langerbeins, Petra; Eichhorst, Barbara; Hallek, Michael

    2016-01-01

    The management of patients with CLL is undergoing significant changes; during the last decade, the outcome of first-line therapies has been markedly improved with the addition of anti-CD20 antibodies to chemotherapy. Today, chemoimmunotherapy for physically fit patients ≤ 65 years should consist of fludarabine, cyclophosphamide, and rituximab (FCR). The combination of bendamustine and rituximab (BR) should be considered in physically fit patients > 65 years and in patients with a higher risk of infections. Patients with reduced fitness and/or relevant comorbidity should receive chlorambucil with a CD20 antibody, preferably obinutuzumab. Regardless of their fitness, patients with CLL carrying genetic aberrations such as del(17p) and/or TP53 mutation poorly respond to chemoimmunotherapy and therefore require different therapeutic approaches. An increasing understanding of the disease biology has led to the development of targeted drugs for the treatment of CLL, such as the BTK inhibitor ibrutinib and PI3K inhibitor idelalisib. These agents have shown efficacy in high-risk and relapsed/refractory patients and are currently being evaluated in clinical trials for first-line therapy. It is anticipated that these compounds and further other novel agents will profoundly change the therapy of CLL.

  15. Contact EPA Region 9 (Pacific Southwest)

    EPA Pesticide Factsheets

    Contact EPA Region 9, Pacific Southwest: 24-hour report of violations and emergencies, environmental complaint tip line, Environmental Information Center, Library, Reception, Employee Locator, Media, Press, Public Affairs.

  16. Contact angle hysteresis of cylindrical drops on chemically heterogeneous striped surfaces.

    PubMed

    Iwamatsu, Masao

    2006-05-15

    Contact angle hysteresis of a macroscopic droplet on a heterogeneous but flat substrate is studied using the interface displacement model. First, the apparent contact angle of a droplet on a heterogeneous surface under the condition of constant volume is considered. By assuming a cylindrical liquid-vapor surface (meniscus) and minimizing the total free energy, we derive an equation for the apparent contact angle, which is similar but different from the well-known Cassie's law. Next, using this modified Cassie's law as a guide to predict the behavior of a droplet on a heterogeneous striped surface, we examine several scenarios of contact angle hysteresis using a periodically striped surface model. By changing the volume of the droplet, we predict a sudden jump of the droplet edge, and a continuous change of the apparent contact angle at the edge of two stripes. Our results suggest that as drop volume is increased (advancing contact lines), the predominant drop configuration observed is the one whose contact angle is large; whereas, decreasing drop volume from a large value (receding contact lines) yields drop configuration that predominantly exhibit the smaller contact angle.

  17. A refractive tilting-plate technique for measurement of dynamic contact angles.

    PubMed

    Smedley, Gregory T; Coles, Donald E

    2005-06-01

    The contact angle is a critical parameter in liquid interface dynamics ranging from liquid spreading on a solid surface on earth to liquid motion in partially filled containers in space. A refractive tilting-plate technique employing a scanning laser beam is developed to conduct an experimental study of a moving contact line, with the intention of making accurate measurements of the contact angle. The technique shows promise as an accurate and potentially fully automated means to determine the velocity dependence of the contact angle at the intersection of the interface between two transparent fluids with a transparent solid surface. Ray tracing calculations are included to reinforce the measurement concept. The principal experiments were conducted at speeds ranging from 0.05 to 1.00 mm/s, both advancing and receding, using an immiscible liquid pair (nonane/formamide) in contact with glass. The contact angle was found to depend for practical purposes only on the sign of the velocity and not on its magnitude for the range of velocities studied. Other observations revealed a bimodal behavior of the contact line that depends on which liquid first contacts the glass, with resulting drift in the dynamic contact angle with time.

  18. Understanding contact angle hysteresis on an ambient solid surface.

    PubMed

    Wang, Yong Jian; Guo, Shuo; Chen, Hsuan-Yi; Tong, Penger

    2016-05-01

    We report a systematic study of contact angle hysteresis (CAH) with direct measurement of the capillary force acting on a contact line formed on the surface of a long glass fiber intersecting a liquid-air interface. The glass fiber of diameter 1-2μm and length 100-200μm is glued onto the front end of a rectangular cantilever beam, which is used for atomic force microscopy. From the measured hysteresis loop of the capillary force for 28 different liquids with varying surface tensions and contact angles, we find a universal behavior of the unbalanced capillary force in the advancing and receding directions and the spring constant of a stretched meniscus by the glass fiber. Measurements of the capillary force and its fluctuations suggest that CAH on an ambient solid surface is caused primarily by two types of coexisting and spatially intertwined defects with opposite natures. The contact line is primarily pinned by the relatively nonwetting (repulsive) defects in the advancing direction and by the relatively wetting (attractive) defects in the receding direction. Based on the experimental observations, we propose a "composite model" of CAH and relevant scaling laws, which explain the basic features of the measured hysteresis force loops.

  19. Understanding contact angle hysteresis on an ambient solid surface

    NASA Astrophysics Data System (ADS)

    Wang, Yong Jian; Guo, Shuo; Chen, Hsuan-Yi; Tong, Penger

    2016-05-01

    We report a systematic study of contact angle hysteresis (CAH) with direct measurement of the capillary force acting on a contact line formed on the surface of a long glass fiber intersecting a liquid-air interface. The glass fiber of diameter 1 -2 μ m and length 100 -200 μ m is glued onto the front end of a rectangular cantilever beam, which is used for atomic force microscopy. From the measured hysteresis loop of the capillary force for 28 different liquids with varying surface tensions and contact angles, we find a universal behavior of the unbalanced capillary force in the advancing and receding directions and the spring constant of a stretched meniscus by the glass fiber. Measurements of the capillary force and its fluctuations suggest that CAH on an ambient solid surface is caused primarily by two types of coexisting and spatially intertwined defects with opposite natures. The contact line is primarily pinned by the relatively nonwetting (repulsive) defects in the advancing direction and by the relatively wetting (attractive) defects in the receding direction. Based on the experimental observations, we propose a "composite model" of CAH and relevant scaling laws, which explain the basic features of the measured hysteresis force loops.

  20. Post-study therapy as a source of confounding in survival analysis of first-line studies in patients with advanced non-small-cell lung cancer.

    PubMed

    Zietemann, Vera D; Schuster, Tibor; Duell, Thomas Hg

    2011-06-01

    Clinical trials exploring the long-term effects of first-line therapy in patients with advanced non-small-cell lung cancer generally disregard subsequent treatment although most patients receive second and third-line therapies. The choice of further therapy depends on critical intermediate events such as disease progression and it is usually left at the physician's discretion. Time-dependent confounding may then arise with standard survival analyses producing biased effect estimates, even in randomized trials. Herein we describe the concept of time-dependent confounding in detail and discuss whether the response to first-line treatment may be a potential time-dependent confounding factor for survival in the context of subsequent therapy. A prospective observational study of 406 patients with advanced non-small-cell lung cancer served as an example base. There is evidence that time-dependent confounding may occur in multivariate survival analysis after first-line therapy when disregarding subsequent treatment. In the light of this important but underestimated aspect some of the large and meaningful recent clinical first-line lung cancer studies are discussed, focussing on subsequent treatment and its potential impact on the survival of the study patients. No recently performed lung cancer trial applied adequate statistical analyses despite the frequent use of subsequent therapies. In conclusion, effect estimates from standard survival analysis may be biased even in randomized controlled trials because of time-dependent confounding. To adequately assess treatment effects on long-term outcomes appropriate statistical analyses need to take subsequent treatment into account.

  1. Everolimus plus exemestane as first-line therapy in HR⁺, HER2⁻ advanced breast cancer in BOLERO-2.

    PubMed

    Beck, J Thaddeus; Hortobagyi, Gabriel N; Campone, Mario; Lebrun, Fabienne; Deleu, Ines; Rugo, Hope S; Pistilli, Barbara; Masuda, Norikazu; Hart, Lowell; Melichar, Bohuslav; Dakhil, Shaker; Geberth, Matthias; Nunzi, Martina; Heng, Daniel Y C; Brechenmacher, Thomas; El-Hashimy, Mona; Douma, Shyanne; Ringeisen, Francois; Piccart, Martine

    2014-02-01

    The present exploratory analysis examined the efficacy, safety, and quality-of-life effects of everolimus (EVE) + exemestane (EXE) in the subgroup of patients in BOLERO-2 whose last treatment before study entry was in the (neo)adjuvant setting. In BOLERO-2, patients with hormone-receptor-positive (HR(+)), human epidermal growth factor receptor-2-negative (HER2(-)) advanced breast cancer recurring/progressing after a nonsteroidal aromatase inhibitor (NSAI) were randomly assigned (2:1) to receive EVE (10 mg/day) + EXE (25 mg/day) or placebo (PBO) + EXE. The primary endpoint was progression-free survival (PFS) by local assessment. Overall, 137 patients received first-line EVE + EXE (n = 100) or PBO + EXE (n = 37). Median PFS by local investigator assessment nearly tripled to 11.5 months with EVE + EXE from 4.1 months with PBO + EXE (hazard ratio = 0.39; 95 % CI 0.25-0.62), while maintaining quality of life. This was confirmed by central assessment (15.2 vs 4.2 months; hazard ratio = 0.32; 95 % CI 0.18-0.57). The marked PFS improvement in patients receiving EVE + EXE as first-line therapy for disease recurrence during or after (neo)adjuvant NSAI therapy supports the efficacy of this combination in the first-line setting. Furthermore, the results highlight the potential benefit of early introduction of EVE + EXE in the management of HR(+), HER2(-) advanced breast cancer in postmenopausal patients.

  2. Serum proteomic test in advanced non-squamous non-small cell lung cancer treated in first line with standard chemotherapy

    PubMed Central

    Grossi, F; Rijavec, E; Genova, C; Barletta, G; Biello, F; Maggioni, C; Burrafato, G; Sini, C; Dal Bello, M G; Meyer, K; Roder, J; Roder, H; Grigorieva, J

    2017-01-01

    Background: VeriStrat is a blood-based proteomic test with predictive and prognostic significance in second-line treatments for non-small cell lung cancer (NSCLC). This trial was designed to investigate the role of VeriStrat in first-line treatment of advanced NSCLC with standard chemotherapy. Here we present the results for 76 non-squamous patients treated with a combination of carboplatin or cisplatin with pemetrexed. Methods: The test-assigned classifications of VeriStrat Good or VeriStrat Poor to samples collected at baseline. The primary end point was progression-free survival (PFS); secondary end points included overall survival (OS) and objective response. Exploratory analyses of end points separately in carboplatin/pemetrexed and cisplatin/pemetrexed subgroups were also conducted. Results: Patients classified as VeriStrat Good had longer PFS and OS than VeriStrat Poor: 6.5 vs 1.6 months and 10.8 vs 3.4 months, respectively; the corresponding hazard ratios (HRs) were 0.36 (P<0.0001) and 0.26 (P<0.0001); they were also more likely to achieve objective response. Prognostic significance of VeriStrat was confirmed in multivariate analysis. Significant differences in OS and PFS between Veristrat classifications were also found when treatment subgroups were analysed separately. Conclusions: The trial demonstrated clinical utility of VeriStrat as a prognostic test for standard first-line chemotherapy of non-squamous advanced NSCLC. PMID:27898657

  3. Surface free energy of a solid from contact angle hysteresis.

    PubMed

    Chibowski, Emil

    2003-04-25

    Nature of contact angle hysteresis is discussed basing on the literature data (Colloids Surf. A 189 (2001) 265) of dynamic advancing and receding contact angles of n-alkanes and n-alcohols on a very smooth surface of 1,1,2,-trichloro-1,2,2,-trifluoroethane (FC-732) film deposited on a silicon plate. The authors considered the liquid absorption and/or retention (swelling) processes responsible for the observed hysteresis. In this paper hysteresis is considered to be due to the liquid film left behind the drop during retreating of its contact line. Using the contact angle hysteresis an approach is suggested for evaluation of the solid surface free energy. Molecular spacing and the film structure are discussed to explain the difference in n-alkanes and n-alcohols behaviour as well as to explain the difference between dispersion free energy gamma(s)(d) and total surface free energy gamma(s)(tot) of FC-732, as determined from the advancing contact angles and the hysteresis, respectively.

  4. Equilibrium contact angle or the most-stable contact angle?

    PubMed

    Montes Ruiz-Cabello, F J; Rodríguez-Valverde, M A; Cabrerizo-Vílchez, M A

    2014-04-01

    It is well-established that the equilibrium contact angle in a thermodynamic framework is an "unattainable" contact angle. Instead, the most-stable contact angle obtained from mechanical stimuli of the system is indeed experimentally accessible. Monitoring the susceptibility of a sessile drop to a mechanical stimulus enables to identify the most stable drop configuration within the practical range of contact angle hysteresis. Two different stimuli may be used with sessile drops: mechanical vibration and tilting. The most stable drop against vibration should reveal the changeless contact angle but against the gravity force, it should reveal the highest resistance to slide down. After the corresponding mechanical stimulus, once the excited drop configuration is examined, the focus will be on the contact angle of the initial drop configuration. This methodology needs to map significantly the static drop configurations with different stable contact angles. The most-stable contact angle, together with the advancing and receding contact angles, completes the description of physically realizable configurations of a solid-liquid system. Since the most-stable contact angle is energetically significant, it may be used in the Wenzel, Cassie or Cassie-Baxter equations accordingly or for the surface energy evaluation.

  5. Contact hysteroscopy.

    PubMed

    Baggish, M S; Barbot, J

    1983-06-01

    In 1907 innovations in optics and illumination made by Maximilian Nitze were applied to hysteroscopy by Charles David, who wrote a treatise of hysteroscopy. David improved illumination by placing an electric incandescent bulb at the intrauterine end of his endoscope and also sealed the distal end of the tube with a piece of glass. The history of the contact endoscope that the authors personally used is connected to the invention by Vulmiere (1952) of a revolutionary illumination process in endoscopy--the "cold light" process. The components of cold light consist of a powerful external light source that is transmitted via a special optical guide into the endometrial cavity. The 1st application of his principle (1963) was an optical trochar contained in a metallic sheath. This simple endoscope was perfected, and in 1973 Barbot and Parent, in France, began to use it to examine the uterine cavity. Discussion focuses on methods, instrumentation, method for examination (grasping the instrument, setup, light source, anesthesia, dilatation, technique, and normal endometrium); cervical neoplasia; nonneoplastic lesions of the endometrium (endometrial polyp, submucous myoma, endometrial hyperplasia); intrauterine device localization; neoplastic lesions of the endometrium; precursors (adenocarcinoma); hysteroscopy in pregnancy (embryoscopy, hydatidiform mole, postpartum hemorrhage, incomplete abortion, spontaneous abortion, induced abortions, and amnioscopy); and examinations of children and infants. The contact endoscope must make light contact with the structure to be viewed. The principles of contact endoscopy depend on an interpretation of color, contour, vascular pattern, and a sense of touch. These are computed together and a diagnosis is made on the basis of previously learned clinical pathologic correlations. The contact endoscope is composed of 3 parts: an optical guide; a cylindric chamber that collects and traps ambient light; and a magnifying eyepiece. The phase of

  6. Simulation and System Analysis of Flow Pulsation at Normal and Emergency for Advanced On-line Monitoring and Control of NPP

    SciTech Connect

    Proskouriakov, K.N.; Moukhine, V.S.

    2002-07-01

    In addition to investigation of thermal-hydraulic processes on NPP with use of computer codes the new system analysis of flow pulsation is worked out. System analysis shows that properties of heat rejection circuits of NPP as oscillatory system are not equal the sum of properties of its separate elements but gives the new properties which must be taken into account. Methods have been worked out for calculating and identifying the sources of thermal-hydraulic disturbances are intended to improve the means of early diagnostics of anomalies in the technological process, to forecast their development, to improve the efficiency of overhauling operations and safety in operation, and also to create advanced on-line monitoring and control of NPP. Conception of the control system development presents. Proposal for main topics R and D areas for advanced NPP monitoring, diagnostic and control are identified. (authors)

  7. 125I brachytherapy of locally advanced non-small-cell lung cancer after one cycle of first-line chemotherapy: a comparison with best supportive care

    PubMed Central

    Song, Jingjing; Fan, Xiaoxi; Zhao, Zhongwei; Chen, Minjiang; Chen, Weiqian; Wu, Fazong; Zhang, Dengke; Chen, Li; Tu, Jianfei; Ji, Jiansong

    2017-01-01

    Objectives The objective of this study was to assess the efficacy of computed tomography (CT)-guided 125I brachytherapy alone in improving the survival and quality of life of patients with unresectable locally advanced non-small-cell lung cancer (NSCLC) after one cycle of first-line chemotherapy. Patients and methods Sixteen patients with locally advanced NSCLC were treated with CT-guided 125I brachytherapy after one cycle of first-line chemotherapy (group A). Sixteen patients who received only best supportive care (group B) were matched up with the patients in group A. Primary end point included survival, and secondary end point included assessment of safety, effectiveness of CT-guided 125I brachytherapy, and improvement in the quality of life. Results The two groups were well balanced in terms of age, disease histology, tumor stage, tumor location, and performance status (P>0.05). The median follow-up time was 16 months (range, 3–30). The total tumor response rate was 75.0% in group A, which was significantly higher than that in group B (0.0%) (P<0.01). The median progression-free survival time was 4.80 months for patients in group A and 1.35 months for patients in group B (P<0.001). Kaplan–Meier survival analysis showed that the median survival time of group A was 9.4±0.3 months versus 8.4±0.1 months in group B (P=0.013). Tumor-related symptoms of patients were significantly relieved, and the quality of life was markedly improved in group A than in group B. Conclusion CT-guided 125I brachytherapy improved the survival of patients with locally advanced NSCLC and quality of life after one cycle of first-line chemotherapy compared with best supportive care. PMID:28280369

  8. Correlation Between E-cadherin Immunoexpression and Efficacy of First Line Platinum-Based Chemotherapy in Advanced High Grade Serous Ovarian Cancer.

    PubMed

    Miše, Branka Petrić; Telesmanić, Vesna Dobrić; Tomić, Snježana; Šundov, Dinka; Čapkun, Vesna; Vrdoljak, Eduard

    2015-04-01

    To analyze correlation between immunoexpression of E-cadherin and efficacy of first line platinum-based chemotherapy in patients with advanced-stage high-grade serous ovarian carcinoma. The expression of E-cadherin was analyzed immunohistochemically in formalin-fixed, paraffin-embedded samples from 98 patients with advanced-stage high-grade serous ovarian cancer and related to clinical features (stage according to the International Federation of Gynecology and Obstetrics (FIGO) and residual tumors after initial cytoreductive surgery), response to platinum-based chemotherapy (according to Response Evaluation Criteria in Solid tumors (RECIST 1.1 criteria)), platinum sensitivity (according to platinum free interval (PFI) as platinum-refractory, platinum-resistant and platinum-sensitive) and patients progression free survival (PFS) and overall survival (OS). E-cadherin immunostaining was positive in 74 and negative in 24 serous ovarian carcinomas. E-cadherin immunoreactivity was not associated with FIGO stage, residual tumor after initial cytoreductive surgery and number of chemotherapy cycles. Positive E-cadherin expression predict significantly better response to first line platinum-based chemotherapy (p < 0.001) and platinum sensitivity (p < 0.001). Moreover, positive E-cadherin expression predict significantly longer PFS (p < 0.001) and OS (p < 0.001). The multivariate analysis for OS showed that positive E-cadherin expression is predictor to platinum sensitivity (p < 0.001) and longer OS (p = 0.01). Positive E-cadherin expression seems to be a predictor of better response to first line platinum-based chemotherapy, platinum sensitivity and favorable clinical outcome in patients with advanced-stage serous ovarian cancer. Negative E-cadherin expression was shown to be significant, independent predictor of poorer PFS and OS. E-cadherin as a marker has predictive and prognostic value.

  9. Paclitaxel plus cisplatin vs. 5-fluorouracil plus cisplatin as first-line treatment for patients with advanced squamous cell esophageal cancer

    PubMed Central

    Liu, Ying; Ren, Zhonghai; Yuan, Long; Xu, Shuning; Yao, Zhihua; Qiao, Lei; Li, Ke

    2016-01-01

    Paclitaxel plus cisplatin and 5-fluorouracil plus cisplatin treatments are effective strategies for patients with advanced esophageal squamous cell carcinoma. This study was to evaluate the safety and efficacy of paclitaxel plus cisplatin and 5-fluorouracil plus cisplatin as first-line chemotherapy for patients with advanced esophageal squamous cell carcinoma. A total of 398 patients with advanced esophageal squamous cell carcinoma who received chemotherapy were included and divided into 2 groups: paclitaxel plus cisplatin group and 5-fluorouracil plus cisplatin group. 195 patients received paclitaxel plus cisplatin and 203 patients received 5-fluorouracil plus cisplatin. The objective response rates were 42.5% and 38.4% for paclitaxel plus cisplatin group and 5-fluorouracil plus cisplatin group, respectively (P=0.948). The median progression-free survival was 7.85 months (95% CI, 6.77-8.94 months) for the paclitaxel plus cisplatin group and 6.53 months (95% CI, 5.63-7.43 months) for the 5-fluorouracil plus cisplatin group with significant difference (P=0.02). The median overall survival was 13.46 months (95% CI, 12.01-14.91 months) for the paclitaxel plus cisplatin group and 12.67 months (95% CI, 11.87-13.47 months) for the 5-fluorouracil plus cisplatin group (P=0.204). The first-line chemotherapy of paclitaxel plus cisplatin had better median progression-free survival than 5-fluorouracil plus cisplatin in patients with advanced esophageal squamous cell carcinoma with tolerable toxicities. PMID:27822423

  10. Design and development of a CPW-based 5-bit switched-line phase shifter using inline metal contact MEMS series switches for 17.25 GHz transmit/receive module application

    NASA Astrophysics Data System (ADS)

    Dey, Sukomal; Koul, Shiban K.

    2014-01-01

    A radio frequency micro-electro-mechanical system (RF-MEMS) phase shifter based on switchable delay line concept with maximum desirable phase shift and good reliability is presented in this paper. The phase shifter is based on the switchable reference and delay line configurations with inline metal contact series switches that employs MEMS systems based on electrostatic actuation and implemented using coplanar waveguide (CPW) configuration. Electromechanical behaviour of the MEMS switch has been extensively investigated using commercially available simulation tools and validated using system level simulation. A detailed design and performance analysis of the phase shifter has been carried out as a function of various structural parameters with reference to the gold-based surface micromachining process on alumina substrate. The mechanical, electrical, transient, intermodulation distortion (IMD) and loss performance of an MEMS switch have been experimentally investigated. The individual primary phase-bits (11.25°/22.5°/45°/90°/180°) that are fundamental building blocks of a complete 5-bit phase shifter have been designed, fabricated and experimentally characterized. Furthermore, two different 5-bit switched-line phase shifters, that lead to 25% size reduction and result in marked improvement in the reliability of the complete 5-bit phase shifter with 30 V actuation voltage, have been developed. The performance comparison between two different CPW-based switched-line phase shifters have been extensively investigated and validated. The complete 5-bit phase shifter demonstrates an average insertion loss of 5.4 dB with a return loss of better than 14 dB at 17.25 GHz. The maximum phase error of 1.3° has been obtained at 17.25 GHz from these 5-bit phase shifters.

  11. Spotlight on crizotinib in the first-line treatment of ALK-positive advanced non-small-cell lung cancer: patients selection and perspectives

    PubMed Central

    Leprieur, Etienne Giroux; Fallet, Vincent; Cadranel, Jacques; Wislez, Marie

    2016-01-01

    Around 4% of advanced non-small-cell lung cancers (NSCLCs) have an ALK rearrangement at the time of diagnosis. This molecular feature is more frequent in young patients, with no/light smoking habit and with adenocarcinoma pathological subtype. Crizotinib is a tyrosine kinase inhibitor, targeting ALK, ROS1, RON, and MET. The preclinical efficacy results led to a fast-track clinical development. The US Food and Drug Administration (FDA) approval was achieved after the Phase I clinical trial in 2011 in ALK-rearranged advanced NSCLC progressing after a first-line treatment. In 2013, the randomized Phase III trial PROFILE-1007 confirmed the efficacy of crizotinib in ALK-rearranged NSCLC, compared to cytotoxic chemotherapy, in second-line setting or more. In 2014, the PROFILE-1014 trial showed the superiority of crizotinib in the first-line setting compared to the pemetrexed platinum doublet chemotherapy. The response rate was 74%, and the progression-free survival was 10.9 months with crizotinib. Based on these results, crizotinib received approval from the FDA and European Medicines Agency for first-line treatment of ALK-rearranged NSCLC. The various molecular mechanisms at the time of the progression (ALK mutations or amplification, ALK-independent mechanisms) encourage performing re-biopsy at the time of progression under crizotinib. The best treatment strategy at the progression (crizotinib continuation beyond progression, switch to second-generation tyrosine kinase inhibitors, or cytotoxic chemotherapy) depends on the phenotype of the progression, the molecular status, and the physical condition of the patient. PMID:28210164

  12. Correlation between EGFR mutation status and response to first-line platinum-based chemotherapy in patients with advanced non-small cell lung cancer

    PubMed Central

    Fang, Shu; Wang, Zhehai; Guo, Jun; Liu, Jie; Li, Changzheng; Liu, Lin; Shi, Huan; Liu, Liyan; Li, Huihui; Xie, Chao; Zhang, Xia; Sun, Wenwen; Li, Minmin

    2014-01-01

    Background The purpose of this research was to investigate the relationship between epidermal growth factor receptor (EGFR) mutations and the response to first-line chemotherapy in patients with advanced non-small cell lung cancer (NSCLC). Methods A total of 266 patients with stage IIIB or IV NSCLC who received platinum-based doublet therapies as first-line chemotherapy were investigated retrospectively, and their clinical data were assessed according to EGFR mutation. Results EGFR mutations were identified in 45.5% of patients. There was no significant difference in response rate between EGFR mutation carriers and EGFR wild-type carriers (P=0.484). Among the patients with Kirsten rat sarcoma viral oncogene homolog (KRAS) wild-type, however, those with EGFR mutations responded better to treatment than EGFR wild-type patients (46.2% versus 20.8%, P=0.043). The disease control rate associated with pemetrexed-based treatments was higher than for vinorelbine-based therapies in EGFR mutation patients (P=0.001). EGFR mutation was found in patients with longer progression-free survival and median survival time, and improved 1-year and 2-year overall survival when compared with EGFR wild-type patients (6.1 versus 5.0 months, P=0.004; 18.9 versus 13.8 months, P=0.001; 81.0% versus 63.4%, P=0.002; and 33.9% versus 22.8% P=0.044, respectively). Patients with the EGFR exon 19 mutation had longer progression-free survival than those with EGFR exon 21 mutation (P=0.007). Multivariate analysis showed that the response to first-line chemotherapy and the presence of EGFR mutations were independent prognostic factors in patients with advanced NSCLC. Conclusion Our data showed that the presence of EGFR mutations meant longer survival times for patients with advanced NSCLC who received platinum-based doublet first-line chemotherapy, especially in those with the exon 19 deletion mutation. Among KRAS wild-type patients, those with EGFR mutation responded better to first-line

  13. Advances in cell culture process development: tools and techniques for improving cell line development and process optimization.

    PubMed

    Sharfstein, Susan T

    2008-01-01

    At the 234th National Meeting of the American Chemical Society, held in Boston, MA, August 19-23, 2007, the ACS BIOT division held two oral sessions on Cell Culture Process Development. In addition, a number of posters were presented in this area. The critical issues facing cell culture process development today are how to effectively respond to the increase in product demands and decreased process timelines while maintaining robust process performance and product quality and responding to the Quality by Design initiative promulgated by the Food and Drug Administration. Two main areas were addressed in the presentations: first, to understand the effects of process conditions on productivity and product quality, and second, to achieve improved production cell lines. A variety of techniques to achieve these goals were presented, including automated flow cytometric analysis, a high-throughput cell analysis and selection method, transcriptional and epigenetic techniques for analysis of cell lines and cell culture systems, and novel techniques for glycoform analysis.

  14. Sample MMM manuscript for submission to AIP advances transient line starting analysis of the ultra-high speed PMSM.

    PubMed

    Cheng, Wenjie; Li, Wei; Xiao, Ling; Li, Ming; Tian, Yongsheng; Sun, Yanhua; Yu, Lie

    2017-05-01

    Aiming at the ultra high speed permanent magnet synchronous motor (PMSM) supported by gas foil bearings (GFBs), this paper calculates the transient line starting of the motor. Firstly, the start effect of the rotor composed of cylindrical PM and stainless steel sleeve is studied. Then, in order to enhance the start torque, copper ring, nickel ring and copper squirrel-cage are introduced in the rotor and their start effect are analysed, respectively. It can be found that the rotor including nickel ring can be accelerated to set speed, but all the other rotors are failed due to the higher PM and braking torques. It can be concluded that some material owning slight large relative permeability can be applied in the rotor to reduce the PM field and contribute to start by using the line-start method.

  15. Sample MMM manuscript for submission to AIP advances transient line starting analysis of the ultra-high speed PMSM

    PubMed Central

    Cheng, Wenjie; Li, Wei; Xiao, ling; Li, Ming; Tian, Yongsheng; Sun, Yanhua; Yu, Lie

    2017-01-01

    Aiming at the ultra high speed permanent magnet synchronous motor (PMSM) supported by gas foil bearings (GFBs), this paper calculates the transient line starting of the motor. Firstly, the start effect of the rotor composed of cylindrical PM and stainless steel sleeve is studied. Then, in order to enhance the start torque, copper ring, nickel ring and copper squirrel-cage are introduced in the rotor and their start effect are analysed, respectively. It can be found that the rotor including nickel ring can be accelerated to set speed, but all the other rotors are failed due to the higher PM and braking torques. It can be concluded that some material owning slight large relative permeability can be applied in the rotor to reduce the PM field and contribute to start by using the line-start method. PMID:28105384

  16. Recent advances in the mitigation of AC voltages occurring in pipelines located close to electric transmission lines

    SciTech Connect

    Southey, R.D.; Dawalibi, F.P. ); Vukonich, W. )

    1994-04-01

    In joint-use corridors where both pipelines and AC electric transmission lines are present, a portion of the energy contained in the electromagnetic field surrounding the electric transmission lines is captured by each pipeline, resulting in induced AC voltages which vary in magnitude throughout the length of each pipeline. During a fault on any of the transmission lines, energization of the earth by supporting structures near the fault can result in large voltages appearing locally between the earth and the steel wall of any nearby pipeline. Some form of mitigation is usually required to reduce these voltages to acceptable levels for the protection of personnel and of the pipeline itself. This paper presents a new mitigation design approach which not only reduces AC voltages effectively and economically, but also provides cathodic protection for the protected pipeline. Performance of this new mitigation method is illustrated with results from computer simulations, which show how important it is to have an accurate electrical model of the soil structure in any interference study. Results from large-scale mitigation design studies performed for ANR Pipeline Company and other gas transmission companies are presented.

  17. Types of Contact Lenses

    MedlinePlus

    ... Consumer Devices Consumer Products Contact Lenses Types of Contact Lenses Share Tweet Linkedin Pin it More sharing ... Orthokeratology (Ortho-K) Decorative (Plano) Contact Lenses Soft Contact Lenses Soft contact lenses are made of soft, ...

  18. Prioritized Contact Transport Stream

    NASA Technical Reports Server (NTRS)

    Hunt, Walter Lee, Jr. (Inventor)

    2015-01-01

    A detection process, contact recognition process, classification process, and identification process are applied to raw sensor data to produce an identified contact record set containing one or more identified contact records. A prioritization process is applied to the identified contact record set to assign a contact priority to each contact record in the identified contact record set. Data are removed from the contact records in the identified contact record set based on the contact priorities assigned to those contact records. A first contact stream is produced from the resulting contact records. The first contact stream is streamed in a contact transport stream. The contact transport stream may include and stream additional contact streams. The contact transport stream may be varied dynamically over time based on parameters such as available bandwidth, contact priority, presence/absence of contacts, system state, and configuration parameters.

  19. MicroRNA Expression Profiling of Peripheral Blood Samples Predicts Resistance to First-line Sunitinib in Advanced Renal Cell Carcinoma Patients12

    PubMed Central

    Gámez-Pozo, Angelo; Antón-Aparicio, Luis M; Bayona, Cristina; Borrega, Pablo; Gallegos Sancho, María I; García-Domínguez, Rocío; de Portugal, Teresa; Ramos-Vázquez, Manuel; Pérez-Carrión, Ramón; Bolós, María V; Madero, Rosario; Sánchez-Navarro, Iker; Fresno Vara, Juan A; Arranz, Enrique Espinosa

    2012-01-01

    Anti-angiogenic therapy benefits many patients with advanced renal cell carcinoma (RCC), but there is still a need for predictive markers that help in selecting the best therapy for individual patients. MicroRNAs (miRNAs) regulate cancer cell behavior and may be attractive biomarkers for prognosis and prediction of response. Forty-four patients with RCC were recruited into this observational prospective study conducted in nine Spanish institutions. Peripheral blood samples were taken before initiation of therapy and 14 days later in patients receiving first-line therapy with sunitinib for advanced RCC. miRNA expression in peripheral blood was assessed using microarrays and L2 boosting was applied to filtered miRNA expression data. Several models predicting poor and prolonged response to sunitinib were constructed and evaluated by binary logistic regression. Blood samples from 38 patients and 287 miRNAs were evaluated. Twenty-eight miRNAs of the 287 were related to poor response and 23 of the 287 were related to prolonged response to sunitinib treatment. Predictive models identified populations with differences in the established end points. In the poor response group, median time to progression was 3.5 months and the overall survival was 8.5, whereas in the prolonged response group these values were 24 and 29.5 months, respectively. Ontology analyses pointed out to cancer-related pathways, such angiogenesis and apoptosis. miRNA expression signatures, measured in peripheral blood, may stratify patients with advanced RCC according to their response to first-line therapy with sunitinib, improving diagnostic accuracy. After proper validation, these signatures could be used to tailor therapy in this setting. PMID:23308047

  20. Efficacy of Capecitabine Plus Oxaliplatin Combination Chemotherapy for Advanced Pancreatic Cancer after Failure of First-Line Gemcitabine-Based Therapy

    PubMed Central

    Chung, Kwang Hyun; Ryu, Ji Kon; Son, Jun Hyuk; Lee, Jae Woo; Jang, Dong Kee; Lee, Sang Hyub; Kim, Yong-Tae

    2017-01-01

    Background/Aims Second-line chemotherapy in patients with advanced pancreatic ductal adenocarcinoma (PDAC) that progresses following gemcitabine-based treatment has not been established. This study aimed to investigate the efficacy and safety of second-line combination chemotherapy with capecitabine and oxaliplatin (XELOX) in these patients. Methods Between August 2011 and May 2014, all patients who received at least one cycle of XELOX (capecitabine, 1,000 mg/m2 twice daily for 14 days; oxaliplatin, 130 mg/m2 on day 1 of a 3-week cycle) combination chemotherapy for unresectable or recurrent PDAC were retrospectively recruited. The response was evaluated every 9 weeks, and the tumor response rate, progression-free survival and overall survival, and adverse events were assessed. Results Sixty-two patients were included; seven patients (11.3%) had a partial tumor response, and 20 patients (32.3%) had stable disease. The median progression-free and overall survival were 88 days (range, 35.1 to 140.9 days) and 158 days (range, 118.1 to 197.9 days), respectively. Patients who remained stable longer with frontline therapy (≥120 days) exhibited significantly longer progression-free and overall survival. The most common grade 3 to 4 adverse events in patients were vomiting (8.1%) and anorexia (6.5%). There was one treatment-related mortality caused by severe neutropenia and typhlitis. Conclusions Second-line XELOX combination chemotherapy demonstrated an acceptable response and survival rate in patients with advanced PDAC who had failed gemcitabine-based chemotherapy. PMID:27965478

  1. Drop rebound after impact: the role of the receding contact angle.

    PubMed

    Antonini, C; Villa, F; Bernagozzi, I; Amirfazli, A; Marengo, M

    2013-12-31

    Data from the literature suggest that the rebound of a drop from a surface can be achieved when the wettability is low, i.e., when contact angles, measured at the triple line (solid-liquid-air), are high. However, no clear criterion exists to predict when a drop will rebound from a surface and which is the key wetting parameter to govern drop rebound (e.g., the "equilibrium" contact angle, θeq, the advancing and the receding contact angles, θA and θR, respectively, the contact angle hysteresis, Δθ, or any combination of these parameters). To clarify the conditions for drop rebound, we conducted experimental tests on different dry solid surfaces with variable wettability, from hydrophobic to superhydrophobic surfaces, with advancing contact angles 108° < θA < 169° and receding contact angles 89° < θR < 161°. It was found that the receding contact angle is the key wetting parameter that influences drop rebound, along with surface hydrophobicity: for the investigated impact conditions (drop diameter 2.4 < D0 < 2.6 mm, impact speed 0.8 < V < 4.1 m/s, Weber number 25 < We < 585), rebound was observed only on surfaces with receding contact angles higher than 100°. Also, the drop rebound time decreased by increasing the receding contact angle. It was also shown that in general care must be taken when using statically defined wetting parameters (such as advancing and receding contact angles) to predict the dynamic behavior of a liquid on a solid surface because the dynamics of the phenomenon may affect surface wetting close to the impact point (e.g., as a result of the transition from the Cassie-Baxter to Wenzel state in the case of the so-called superhydrophobic surfaces) and thus affect the drop rebound.

  2. Advancing scientific base lines for the integrated assessment of climate change impacts and adaptation in mountain regions in developing countries

    NASA Astrophysics Data System (ADS)

    Huggel, C.; Jurt, N. Salzmann, C.; Calanca, P.; Ordonez, A. Diaz, J.; Zappa, T. Jonas M.; Konzelmann, T.; Lagos, P.; Obersteiner, M.; Rohrer, M.; Silverio, W.

    2009-04-01

    Adaptation to climate change impacts is a major challenge for the human society. For countries in development, consistent base lines of expected impacts at the regional scale are required to plan and implement low-cost adaptation measures that effectively address societal needs. However, donors and implementing agencies are often confronted with a lack of scientific data. This poses a serious problem to global adaptation funds, such as the one established under the UNFCCC, which are predominantly directed towards developing countries. This contribution summarizes recent experiences gained from international projects in the Andes, by the Peruvian and Swiss Governments, and the World Bank, on the development of scientific base lines for selected regions in the Peruvian Andes. The focus is on the nexus between water resources, food security and natural disasters. The analysis shows that Peruvian Andes are among the most vulnerable regions to climate change. Negative impacts on water resources are expected from the rapid retreat of glaciers, extended and more frequent drought periods and increasing human needs. Climate change impacts are exacerbated by continued sub-optimal resource management. As a consequence of growing stresses, water availability for human consumption, agriculture and energy generation is increasingly limited. Assessment of the current conditions and reliable projections for the future are hampered by scarce data availability and methodological problems, such as downscaling of global and regional climate scenarios, cross-sector effects, and others. It is critical that related uncertainties, and the propagation thereof, are assessed throughout the impact analysis for an improved management of adaptation measures. Challenges furthermore include communication and understanding among different actors, including the scientific community, political and implementation agencies, and local population. Based on our experiences we will outline a good practice

  3. Efficacy of Second-line Tyrosine Kinase Inhibitors in the Treatment of Metastatic Advanced Non-small-cell Lung Cancer Harboring Exon 19 and 21 EGFR Mutations

    PubMed Central

    Zheng, Zhen; Jin, Xiance; Lin, Baochai; Su, Huafang; Chen, Hanbin; Fei, Shaoran; Zhao, Lihao; Deng, Xia; Xie, Deyao; Xie, Congying

    2017-01-01

    Background: Although superior clinical benefits of first-line epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in the treatment of advanced non-small-cell lung cancer (NSCLC) had been reported with different sensitivity, the sensitivity of second-line TKIs in NSCLC patients with different EFGR mutations was unknown. The purpose of this study is to investigate the clinical outcome of second-line EGFR-TKIs in the treatment of NSCLC patients according to different EGFR genotypes. Methods: The treatment outcomes of 166 NSCLC patients with different EGFR mutations treated by second-line TKIs were retrospectively reviewed. The efficacy was evaluated with Pearson chi-square or Fisher's exact tests, Log-rank test and Cox proportional hazards model. Results: The disease control rate (DCR) and objective response rate (ORR) of enrolled NSCLC patients were 77.7% and 11.4%, respectively. The exon 19 deletion group had a significantly longer median progression-free survival (PFS) (6.7 vs. 4.5 months, P=0.002) and overall survival (OS) (13.7 vs. 11.7 months, P=0.02) compared with the exon 19 L858R mutation group for NSCLC patients, as well for patients with brain metastasis [PFS: (6.7 vs. 3.9 months, p<0.001), OS: (13.7 vs. 7.9 months, p=0.006)]. No significant difference on PFS and OS was observed between exon 19 deletion and L858R mutation group for patients with bone metastasis. EGFR genotype and ECOG PS were independent predictors of PFS. Never smoking, exon 19 deletion, EGOC PS (0-1) and no brain metastasis were correlated with longer OS. No significant difference on side effect between exon 19 and 21 mutation group was observed. Conclusions: NSCLC patients harboring exon 19 deletion achieved better PFS and OS than those with L858R mutation, indicating that EGFR mutation is a significant prognostic factor for advanced NSCLC patients with and without brain metastasis receiving second-line EGFR-TKIs treatment. PMID:28367239

  4. Dynamic contact angle measurements on superhydrophobic surfaces

    NASA Astrophysics Data System (ADS)

    Kim, Jeong-Hyun; Kavehpour, H. Pirouz; Rothstein, Jonathan P.

    2015-03-01

    In this paper, the dynamic advancing and receding contact angles of a series of aqueous solutions were measured on a number of hydrophobic and superhydrophobic surfaces using a modified Wilhelmy plate technique. Superhydrophobic surfaces are hydrophobic surfaces with micron or nanometer sized surface roughness. These surfaces have very large static advancing contact angles and little static contact angle hysteresis. In this study, the dynamic advancing and dynamic receding contact angles on superhydrophobic surfaces were measured as a function of plate velocity and capillary number. The dynamic contact angles measured on a smooth hydrophobic Teflon surface were found to obey the scaling with capillary number predicted by the Cox-Voinov-Tanner law, θD3 ∝ Ca. The response of the dynamic contact angle on the superhydrophobic surfaces, however, did not follow the same scaling law. The advancing contact angle was found to remain constant at θA = 160∘, independent of capillary number. The dynamic receding contact angle measurements on superhydrophobic surfaces were found to decrease with increasing capillary number; however, the presence of slip on the superhydrophobic surface was found to result in a shift in the onset of dynamic contact angle variation to larger capillary numbers. In addition, a much weaker dependence of the dynamic contact angle on capillary number was observed for some of the superhydrophobic surfaces tested.

  5. Advances in the helium-jet coupled on-line mass separator RAMA. [Recoil Atom Mass Analyzer

    SciTech Connect

    Moltz, D M; Aysto, J; Cable, M D; Parry, R F; Haustein, P E; Wouters, J M; Cerny, J

    1980-01-01

    General improvements to the on-line mass separator RAMA (Recoil Atom Mass Analyzer) have yielded a greater reliability and efficiency for some elements. A new utilitarian helium-jet chamber has been installed to facilitate quick target and degrader foil changes in addition to a new ion source holder. A higher efficiency hollow-cathode, cathode-extraction ion source, for lower melting point elements (< 1200/sup 0/C) has also been designed. Tests with the beta-delayed proton emitter /sup 37/Ca showed a factor of five increase in yield over the old hollow-cathode, anode-extraction source. A differentially-pumped-tape drive system compatible with both ..gamma..-..gamma.. and ..beta..-..gamma.. experiments has been incorporated into the general detection system. All major operating parameters will soon be monitored by a complete stand-alone microprocessor system which will eventually be upgraded to a closed-loop control system.

  6. Fulvestrant 500 mg versus anastrozole 1 mg for the first-line treatment of advanced breast cancer: follow-up analysis from the randomized 'FIRST' study.

    PubMed

    Robertson, John F R; Lindemann, Justin P O; Llombart-Cussac, Antonio; Rolski, Janusz; Feltl, David; Dewar, John; Emerson, Laura; Dean, Andrew; Ellis, Matthew J

    2012-11-01

    Fulvestrant fIRst-line Study comparing endocrine Treatments is a phase II, randomized, open-label study comparing fulvestrant 500 mg with anastrozole 1 mg as first-line endocrine therapy for postmenopausal women with hormone receptor-positive (HR+) advanced breast cancer. At data cut-off, only 36 % of patients had progressed and the median time to progression (TTP) had not been reached for fulvestrant. Here, we report follow-up data for TTP for fulvestrant 500 mg versus anastrozole 1 mg. Key inclusion criteria were postmenopausal women with estrogen receptor-positive and/or progesterone receptor-positive locally advanced or metastatic breast cancer and no prior endocrine therapy. Key exclusion criteria were presence of life-threatening metastases and prior treatment with a non-approved drug. Fulvestrant was administered 500 mg/month plus 500 mg on day 14 of month 1; anastrozole was administered 1 mg/day. TTP was defined by modified Response Evaluation Criteria in Solid Tumors v1.0 before data cut-off for the primary analysis, and investigator opinion after data cut-off. Best overall response to subsequent therapy and serious adverse events are also reported. In total, 205 patients received fulvestrant 500 mg (n = 102) or anastrozole (n = 103). Follow-up analysis was performed when 79.5 % of patients had discontinued study treatment. Median TTP was 23.4 months for fulvestrant versus 13.1 months for anastrozole; a 34 % reduction in risk of progression (hazard ratio 0.66; 95 % confidence interval: 0.47, 0.92; P = 0.01). Best overall response to subsequent therapy and clinical benefit rate for subsequent endocrine therapy was similar between the treatment groups. No new safety concerns for fulvestrant 500 mg were documented. These longer-term, follow-up results confirm efficacy benefit for fulvestrant 500 mg versus anastrozole as first-line endocrine therapy for HR+ advanced breast cancer in terms of TTP, and, importantly, show similar best overall response rates to

  7. Cigarette smoking habit does not reduce the benefit from first line trastuzumab-based treatment in advanced breast cancer patients.

    PubMed

    Santini, Daniele; Vincenzi, Bruno; Adamo, Vincenzo; Addeo, Raffaele; Fusco, Vittorio; Russo, Antonio; Montemurro, Filippo; Roato, Ilaria; Redana, Stefania; Lanzetta, Gaetano; Satolli, Maria Antonietta; Berruti, Alfredo; Leoni, Valentina; Galluzzo, Sara; Antimi, Mauro; Ferraro, Giuseppa; Rossi, Maura; Del Prete, Salvatore; Valerio, Maria Rosaria; Marra, Monica; Caraglia, Michele; Tonini, Giuseppe

    2011-06-01

    Many ErbB2-positive cancers may show intrinsic resistance, and the frequent development of acquired resistance to ErbB-targeted agents represents a substantial clinical problem. The constitutive NF-κB activation in some HER-2/neu positive breast cancer may represent a potential cause of resistance to trastuzumab therapy. Preclinical data revealed that 4-(N-Methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK), the tobacco-specific nitrosamine is able to enhance NF-κB DNA binding activity and theoretically to increase the resistance to trastuzumab. Two hundred and forty-eight women with pathologically confirmed, uni- or bidimensionally measurable, HER-2-positive metastatic breast cancer (MBC) treated with trastuzumab-based therapy as first line combination for metastatic disease were considered eligible. For all included patients data on smoking habit were detectable from medical records. We retrospectively analysed the smoking habits of 248 MBC patients and correlated these habits with activity and efficacy of trastuzumab-based therapy. No statistically significant difference in terms of response rate (RR), time to progression (TTP) and overall survival (OS) was identified between smokers (former plus active smokers) and never smokers. Moreover, no statistically significant difference in terms of RR, TTP and OS was identified either comparing active smokers and former smokers. Moreover, we did not observed any significant statistical difference in terms of TTP and OS between smokers ≥10 cigarettes/day and <10 cigarettes/day. This study clearly showed lack of any correlation between cigarette smoking habit and both activity and efficacy of trastuzumab-based first line therapy in metastatic HER2/neu positive breast cancer patients.

  8. A Systematic Review and Network Meta-Analysis of Biologic Agents in the First Line Setting for Advanced Colorectal Cancer

    PubMed Central

    Kumachev, Alexander; Yan, Marie; Berry, Scott; Ko, Yoo-Joung; Martinez, Maria C. R.; Shah, Keya; Chan, Kelvin K. W.

    2015-01-01

    Background Epithelial growth factor receptor inhibitors (EGFRis) and bevacizumab (BEV) are used in combination with chemotherapy for the treatment of metastatic colorectal cancer (mCRC). However, few randomized controlled trials (RCTs) have directly compared their relative efficacy on progression-free survival (PFS) and overall survival (OS). Methods We conducted a systematic review of first-line RCTs comparing (1) EGFRis vs. BEV, with chemotherapy in both arms (2) EGFRis + chemotherapy vs. chemotherapy alone, or (3) BEV + chemotherapy vs. chemotherapy alone, using Cochrane methodology. Data on and PFS and OS were extracted using the Parmar method. Pairwise meta-analyses and Bayesian network meta-analyses (NMA) were conducted to estimate the direct, indirect and combined PFS and OS hazard ratios (HRs) comparing EGFRis to BEV. Results Seventeen RCTs contained extractable data for quantitative analysis. Combining direct and indirect data using an NMA did not show a statistical difference between EGFRis versus BEV (PFS HR = 1.11 (95% CR: 0.92–1.36) and OS HR = 0.91 (95% CR: 0.75–1.09)). Direct meta-analysis (3 RCTs), indirect (14 RCTs) and combined (17 RCTs) NMA of PFS HRs were concordant and did not show a difference between EGFRis and BEV. Meta-analysis of OS using direct evidence, largely influenced by one trial, showed an improvement with EGFRis therapy (HR = 0.79 (95% CR: 0.65–0.98)), while indirect and combined NMA of OS did not show a difference between EGFRis and BEV Successive inclusions of trials over time in the combined NMA did not show superiority of EGFRis over BEV. Conclusions Our findings did not support OS or PFS benefits of EGFRis over BEV in first-line mCRC. PMID:26474403

  9. Apparent contact angle and contact angle hysteresis on liquid infused surfaces

    NASA Astrophysics Data System (ADS)

    Semprebon, Ciro; McHale, Glen; Kusumaatmaja, Halim

    We theoretically investigate the apparent contact angle and contact angle hysteresis of a droplet placed on a liquid infused surface. We show that the apparent contact angle is not uniquely defined by material parameters, but also has a strong dependence on the relative size between the droplet and its surrounding wetting ridge formed by the infusing liquid. We derive a closed form expression for the contact angle in the limit of vanishing wetting ridge, and compute the correction for small but finite ridge, which corresponds to an effective line tension term. We also predict contact angle hysteresis on liquid infused surfaces generated by the pinning of the contact lines by the surface corrugations. Our analytical expressions for both the apparent contact angle and contact angle hysteresis can be interpreted as `weighted sums' between the contact angles of the infusing liquid relative to the droplet and surrounding gas phases, where the weighting coefficients are given by ratios of the fluid surface tensions.

  10. Apparent contact angle and contact angle hysteresis on liquid infused surfaces.

    PubMed

    Semprebon, Ciro; McHale, Glen; Kusumaatmaja, Halim

    2016-12-21

    We theoretically investigate the apparent contact angle and contact angle hysteresis of a droplet placed on a liquid infused surface. We show that the apparent contact angle is not uniquely defined by material parameters, but also has a dependence on the relative size between the droplet and its surrounding wetting ridge formed by the infusing liquid. We derive a closed form expression for the contact angle in the limit of vanishing wetting ridge, and compute the correction for small but finite ridge, which corresponds to an effective line tension term. We also predict contact angle hysteresis on liquid infused surfaces generated by the pinning of the contact lines by the surface corrugations. Our analytical expressions for both the apparent contact angle and contact angle hysteresis can be interpreted as 'weighted sums' between the contact angles of the infusing liquid relative to the droplet and surrounding gas phases, where the weighting coefficients are given by ratios of the fluid surface tensions.

  11. Contact angle hysteresis and pinning at periodic defects in statics.

    PubMed

    Iliev, Stanimir; Pesheva, Nina; Nikolayev, Vadim S

    2014-07-01

    This article deals with the theoretical prediction of the wetting hysteresis on nonideal solid surfaces in terms of the surface heterogeneity parameters. The spatially periodical chemical heterogeneity is considered. We propose precise definitions for both the advancing and the receding contact angles for the Wilhelmy plate geometry. It is well known that in such a system, a multitude of metastable states of the liquid meniscus occurs for each different relative position of the defect pattern on the plate with respect to the liquid level. As usual, the static advancing and receding angles are assumed to be a consequence of the preceding contact line motion in the respective direction. It is shown how to select the appropriate states among all metastable states. Their selection is discussed. The proposed definitions are applicable to both the static and the dynamic contact angles on heterogeneous surfaces. The static advancing and receding angles are calculated for two examples of periodic heterogeneity patterns with sharp borders: the horizontal alternating stripes of a different wettability (studied analytically) and the doubly periodic pattern of circular defects on a homogeneous base (studied numerically). The wetting hysteresis is determined as a function of the defect density and the spatial period. A comparison with the existing results is carried out.

  12. Contact angle hysteresis and pinning at periodic defects in statics

    NASA Astrophysics Data System (ADS)

    Iliev, Stanimir; Pesheva, Nina; Nikolayev, Vadim S.

    2014-07-01

    This article deals with the theoretical prediction of the wetting hysteresis on nonideal solid surfaces in terms of the surface heterogeneity parameters. The spatially periodical chemical heterogeneity is considered. We propose precise definitions for both the advancing and the receding contact angles for the Wilhelmy plate geometry. It is well known that in such a system, a multitude of metastable states of the liquid meniscus occurs for each different relative position of the defect pattern on the plate with respect to the liquid level. As usual, the static advancing and receding angles are assumed to be a consequence of the preceding contact line motion in the respective direction. It is shown how to select the appropriate states among all metastable states. Their selection is discussed. The proposed definitions are applicable to both the static and the dynamic contact angles on heterogeneous surfaces. The static advancing and receding angles are calculated for two examples of periodic heterogeneity patterns with sharp borders: the horizontal alternating stripes of a different wettability (studied analytically) and the doubly periodic pattern of circular defects on a homogeneous base (studied numerically). The wetting hysteresis is determined as a function of the defect density and the spatial period. A comparison with the existing results is carried out.

  13. Operation of beam line facilities for real-time x-ray studies at Sector 7 of the advanced photon source. Final Report

    SciTech Connect

    Clarke, Roy

    2003-09-10

    This Final Report documents the research accomplishments achieved in the first phase of operations of a new Advanced Photon Source beam line (7-ID MHATT-CAT) dedicated to real-time x-ray studies. The period covered by this report covers the establishment of a world-class facility for time-dependent x-ray studies of materials. During this period many new and innovative research programs were initiated at Sector 7 with support of this grant, most notably using a combination of ultrafast lasers and pulsed synchrotron radiation. This work initiated a new frontier of materials research: namely, the study of the dynamics of materials under extreme conditions of high intensity impulsive laser irradiation.

  14. Recent Advances in On-Line Methods Based on Extraction for Speciation Analysis of Chromium in Environmental Matrices.

    PubMed

    Trzonkowska, Laura; Leśniewska, Barbara; Godlewska-Żyłkiewicz, Beata

    2016-07-03

    The biological activity of Cr(III) and Cr(VI) species, their chemical behavior, and toxic effects are dissimilar. The speciation analysis of Cr(III) and Cr(VI) in environmental matrices is then of great importance and much research has been devoted to this area. This review presents recent developments in on-line speciation analysis of chromium in such samples. Flow systems have proved to be excellent tools for automation of sample pretreatment, separation/preconcentration of chromium species, and their detection by various instrumental techniques. Analytical strategies used in chromium speciation analysis discussed in this review are divided into categories based on selective extraction/separation of chromium species on solid sorbents and liquid-liquid extraction of chromium species. The most popular strategy is that based on solid-phase extraction. Therefore, this review shows the potential of novel materials designed and used for selective binding of chromium species. The progress in miniaturization of measurement systems is also presented.

  15. Advanced in-line optical metrology of sub-10nm structures for gate all around devices (GAA)

    NASA Astrophysics Data System (ADS)

    Muthinti, Raja; Loubet, Nicolas; Chao, Robin; Ott, John; Guillorn, Michael; Felix, Nelson; Gaudiello, John; Lund, Parker; Cepler, Aron; Sendelbach, Matthew; Cohen, Oded; Wolfling, Shay; Bozdog, Cornel; Klare, Mark

    2016-03-01

    Gate-all-around (GAA) nanowire (NW) devices have long been acknowledged as the ultimate device from an electrostatic scaling point of view. The GAA architecture offers improved short channel effect (SCE) immunity compared to single and double gate planar, FinFET, and trigate structures. One attractive proposal for making GAA devices involves the use of a multilayer fin-like structure consisting of layers of Si and SiGe. However, such structures pose various metrology challenges, both geometrical and material. Optical Scatterometry, also called optical critical dimension (OCD) is a fast, accurate and non-destructive in-line metrology technique well suited for GAA integration challenges. In this work, OCD is used as an enabler for the process development of nanowire devices, extending its abilities to learn new material and process aspects specific to this novel device integration. The specific metrology challenges from multiple key steps in the process flow are detailed, along with the corresponding OCD solutions and results. In addition, Low Energy X-Ray Fluorescence (LE-XRF) is applied to process steps before and after the removal of the SiGe layers in order to quantify the amount of Ge present at each step. These results are correlated to OCD measurements of the Ge content, demonstrating that both OCD and LE-XRF are sensitive to Ge content for these applications.

  16. Risk Factors for GI Adverse Events in a Phase III Randomized Trial of Bevacizumab in First-Line Therapy of Advanced Ovarian Cancer: A Gynecologic Oncology Group Study

    PubMed Central

    Burger, Robert A.; Brady, Mark F.; Bookman, Michael A.; Monk, Bradley J.; Walker, Joan L.; Homesley, Howard D.; Fowler, Jeffrey; Greer, Benjamin E.; Boente, Matthew; Fleming, Gini F.; Lim, Peter C.; Rubin, Stephen C.; Katsumata, Noriyuki; Liang, Sharon X.

    2014-01-01

    Purpose To evaluate risk factors for GI adverse events (AEs) within a phase III trial of bevacizumab in first-line ovarian cancer therapy. Patients and Methods Women with previously untreated advanced disease after surgery were randomly allocated to six cycles of platinum-taxane chemotherapy plus placebo cycles (C)2 to C22 (R1); chemotherapy plus bevacizumab C2 to C6 plus placebo C7 to C22 (R2); or chemotherapy plus bevacizumab C2 to C22 (R3). Patients were evaluated for history or on-study development of potential risk factors for GI AEs defined as grade ≥ 2 perforation, fistula, necrosis, or hemorrhage. Results Of 1,873 patients enrolled, 1,759 (94%) were evaluable, and 2.8% (50 of 1,759) experienced a GI AE: 10 of 587 (1.7%, R1), 20 of 587 (3.4%, R2), and 20 of 585 (3.4%, R3). Univariable analyses indicated that previous treatment of inflammatory bowel disease (IBD; P = .005) and small bowel resection (SBR; P = .032) or large bowel resection (LBR; P = .012) at primary surgery were significantly associated with a GI AE. The multivariable estimated relative odds of a GI AE were 13.4 (95% CI, 3.44 to 52.3; P < .001) for IBD; 2.05 (95% CI, 1.09 to 3.88; P = .026) for LBR; 1.95 (95% CI, 0.894 to 4.25; P = .093) for SBR; and 2.15 for bevacizumab exposure (aggregated 95% CI, 1.05 to 4.40; P = .036). Conclusion History of treatment for IBD, and bowel resection at primary surgery, increase the odds of GI AEs in patients receiving first-line platinum-taxane chemotherapy for advanced ovarian cancer. After accounting for these risk factors, concurrent bevacizumab doubles the odds of a GI AE, but is not appreciably increased by continuation beyond chemotherapy. PMID:24637999

  17. Phase II study of necitumumab plus modified FOLFOX6 as first-line treatment in patients with locally advanced or metastatic colorectal cancer

    PubMed Central

    Elez, E; Hendlisz, A; Delaunoit, T; Sastre, J; Cervantes, A; Varea, R; Chao, G; Wallin, J; Tabernero, J

    2016-01-01

    Background: This single-arm phase II study investigated the EGFR monoclonal antibody necitumumab plus modified FOLFOX6 (mFOLFOX6) in first-line treatment of locally advanced or metastatic colorectal cancer (mCRC). Methods: Patients received 800-mg intravenous necitumumab (day 1; 2-week cycles), followed by oxaliplatin 85 mg m−2, folinic acid 400 mg m−2, and 5-fluorouracil (400 mg m−2 bolus then 2400 mg m−2 over 46 h). Radiographic evaluation was performed every 8 weeks until progression. Primary endpoint was objective response rate. Results: Forty-four patients were enrolled and treated. Objective response rate was 63.6% (95% confidence interval 47.8–77.6); complete response was observed in four patients; median duration of response was 10.0 months (7.0–16.0). Median overall survival (OS) and progression-free survival (PFS) were 22.5 (11.0–30.0) and 10.0 months (7.0–12.0), respectively. Clinical outcome was better in patients with KRAS exon 2 wild type (median OS 30.0 months (23.0–NA); median PFS 12.0 (8.0–20.0)), compared with KRAS exon 2 mutant tumours (median OS 7.0 months (5.0–37.0); median PFS 7.0 (4.0–18.0)). The most common grade ⩾3 adverse events were neutropenia (29.5%), asthenia (27.3%), and rash (20.5%). Conclusion: First-line necitumumab+mFOLFOX6 was active with manageable toxicity in locally advanced or mCRC; additional evaluation of the impact of tumour RAS mutation status is warranted. PMID:26766738

  18. A phase II study of 5-fluorouracil/leucovorin in combination with paclitaxel and oxaliplatin as first-line treatment for patients with advanced gastric cancer.

    PubMed

    Lin, Rong-Bo; Fan, Nan-Feng; Guo, Zeng-Qing; Wang, Xiao-Jie; Liu, Jie; Chen, Ling

    2008-12-01

    The objective of this study was to evaluate the efficacy and safety of the POF regimen (biweekly 5-fluorouracil/leucovorin combined with paclitaxel and oxaliplatin) as first-line treatment for advanced gastric cancer (AGC). Twenty-seven previously untreated patients with advanced adenocarcinoma of the gastric or gastroesophageal junction were eligible for this study. The chemotherapy regimen consisted of a 3-hour infusion of paclitaxel (135 mg/m(2)) followed by oxaliplatin (85 mg/m(2)) and leucovorin (400 mg/m(2)), administered simultaneously over a 2-hour infusion period, followed by an infusion of 5-fluorouracil (2400 mg/m(2)) over a 46-hour period. Twenty-one patients had measurable lesions: four complete responses, eight partial responses and seven stable diseases. At a median follow-up of 610 days, median survival was 348 days. Frequent grade 3 to 4 toxicities were: neutropenia (29.6%), stomatitis (7.4%), nausea (7.4%), vomiting (7.4%), hepatic dysfunction (3.7%), and fatigue (18.5%). No treatment-related deaths occurred. The POF regimen appears to be efficacious and is well tolerated in patients with AGC.

  19. Single pemetrexed is noninferior to platinum-based pemetrexed doublet as first-line treatment on elderly Chinese patients with advanced nonsquamous nonsmall cell lung cancer

    PubMed Central

    Pu, Xiaolin; Li, Wei; Lu, Binbin; Wang, Zhaoxia; Yang, Min; Fan, Weifei; Meng, Lijuan; Lv, Zhigang; Xie, Yuchun; Wang, Jun

    2017-01-01

    Abstract Background: To evaluate the clinical efficacy and toxicity of single pemetrexed treatment compared with platinum-based pemetrexed doublet pemetrexed-based as first-line treatment for advanced nonsquamous nonsmall cell lung cancer (NS-NSCLC) in elderly Chinese patients. Methods: The study retrospectively reviewed 175 elderly Chinese patients with NS-NSCLC from June 2010 to September 2013: 90 patients received single pemetrexed treatment, 45 received pemetrexed plus oxaliplatin, and 40 received pemetrexed plus carboplatin. Clinical efficacy was assessed using disease control rate (DCR), overall survival (OS), and progression-free survival (PFS). Results: DCR, OS, and PFS did not significantly differ between single pemetrexed treatment (OS: 14.9 months; DCR: 62.2%; PFS: 3.3 months), pemetrexed plus oxaliplatin (OS: 16.5 months; DCR: 71.1%; PFS: 4.5 months), and pemetrexed plus carboplatin (OS: 15.5 months; DCR: 70.0%; PFS: 4.6 months) groups. Pemetrexed treatment caused significantly lower incidences of adverse events, such as hepatotoxicity and peripheral nerve injury. Performance status (PS), TNM stage, and Thymidylate synthase (TS) expression were predictive factors of DCR. Pemetrexed chemotherapy cycles, PS, and TNM stage were independent prognostic factors. Conclusions: Single pemetrexed was noninferior to platinum-based pemetrexed doublet for clinical efficacy and safety in elderly Chinese patients with advanced NS-NSCLC. Chemotherapy cycles, performance status, and TNM stage were independent prognostic factors. PMID:28296721

  20. A Randomized, Phase II, Biomarker-Selected Study Comparing Erlotinib to Erlotinib Intercalated With Chemotherapy in First-Line Therapy for Advanced Non–Small-Cell Lung Cancer

    PubMed Central

    Hirsch, Fred R.; Kabbinavar, Fairooz; Eisen, Tim; Martins, Renato; Schnell, Fredrick M.; Dziadziuszko, Rafal; Richardson, Katherine; Richardson, Frank; Wacker, Bret; Sternberg, David W.; Rusk, Jason; Franklin, Wilbur A.; Varella-Garcia, Marileila; Bunn, Paul A.; Camidge, D. Ross

    2011-01-01

    Purpose Erlotinib prolongs survival in patients with advanced non–small-cell lung cancer (NSCLC). We report the results of a randomized, phase II study of erlotinib alone or intercalated with chemotherapy (CT + erlotinib) in chemotherapy-naïve patients with advanced NSCLC who were positive for epidermal growth factor receptor (EGFR) protein expression and/or with high EGFR gene copy number. Patients and Methods A total of 143 patients were randomly assigned to either erlotinib 150 mg daily orally until disease progression (PD) occurred or to chemotherapy with paclitaxel 200 mg/m2 intravenously (IV) and carboplatin dosed by creatinine clearance (AUC 6) IV on day 1 intercalated with erlotinib 150 mg orally on days 2 through 15 every 3 weeks for four cycles followed by erlotinib 150 mg orally until PD occurred (CT + erlotinib). The primary end point was 6-month progression-free survival (PFS); secondary end points included response rate, PFS, and survival. EGFR, KRAS mutation, EGFR fluorescent in situ hybridization and immunohistochemistry, and E-cadherin and vimentin protein levels were also assessed. Results Six-month PFS rates were 26% and 31% for the two arms (CT + erlotinib and erlotinib alone, respectively). Both were less than the historical control of 45% (P = .001 and P = .011, respectively). Median PFS times were 4.57 and 2.69 months, respectively. Patients with tumors harboring EGFR activating mutations fared better on erlotinib alone (median PFS, 18.2 months v 4.9 months for CT + erlotinib). Conclusion The feasibility of a multicenter biomarker-driven study was demonstrated, but neither treatment arms exceeded historical controls. This study does not support combined chemotherapy and erlotinib in first-line treatment of EGFR-selected advanced NSCLC, and the patients with tumors harboring EGFR mutations had a better outcome on erlotinib alone. PMID:21825259

  1. Phase I dose-finding study of sorafenib with FOLFOX4 as first-line treatment in patients with unresectable locally advanced or metastatic gastric cancer

    PubMed Central

    Chi, Yihebali; Yang, Jianliang; Yang, Sheng; Sun, Yongkun; Jia, Bo

    2015-01-01

    Objective To determine the maximum tolerated dose (MTD), dose-limiting toxicity (DLT) and efficacy of sorafenib in combination with FOLFOX4 (oxaliplatin/leucovorin (LV)/5-fluorouracil) as first-line treatment for advanced gastric cancer, we performed a phase I dose-finding study in nine evaluable patients with unresectable locally advanced or metastatic gastric cancer or gastroesophageal junction adenocarcinoma. Methods According to modified Fibonacci method, the design of this study was to guide elevation of the sorafenib dosage to the next level (from 200 mg twice daily to 400 mg twice daily and then, if tolerated, 600 mg twice daily). If the patient achieved complete response (CR), partial response (PR) or stable disease (SD) after eight cycles of treatment, combination chemotherapy was scheduled to be discontinued and sorafenib monotherapy continued at the original dose until either disease progression or unacceptable toxicity. Results In sorafenib 200 mg twice daily group, DLT was observed in 1 of 6 patients, and in 400 mg twice daily group, it was observed in 2 of 3 patients. Seven of 9 (77.8%) evaluable patients achieved PR, with a median overall survival (OS) of 11.8 [95% confidence interval (CI): 8.9-14.7] months. Common adverse effects include hand-foot syndrome, leukopenia, neutropenia, anorexia, and nausea. Conclusions Twice-daily dosing of sorafenib 200 mg in combination with FOLFOX4 was proven effective and safe for the treatment of advanced gastric cancer, and could be an appropriate dosage for subsequent phase II clinical studies. PMID:26157320

  2. Preliminary Results of an On-Line, Multi-Spectrometer Fission Product Monitoring System to Support Advanced Gas Reactor Fuel Testing and Qualification in the Advanced Test Reactor at the Idaho National Laboratory

    SciTech Connect

    Dawn M. Scates; John K. Hartwell; John B. Walter; Mark W. Drigert

    2007-10-01

    The Advanced Gas Reactor -1 (AGR-1) experiment is the first experiment in a series of eight separate low enriched uranium (LEU) oxycarbide (UCO) tri-isotropic (TRISO) particle fuel (in compact form) experiments scheduled for placement in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). The experiment began irradiation in the ATR with a cycle that reached full power on December 26, 2006 and will continue irradiation for about 2.5 years. During this time six separate capsules, will be irradiated in an inert sweep gas atmosphere with individual on-line fission product monitoring on its effluent to track performance of the fuel in each individual capsule during irradiation. The goals of the irradiation experiment is to provide irradiation performance data to support fuel process development, to qualify fuel for normal operating conditions, to support development and validation of fuel, and to provide irradiated fuel and materials for post irradiation examination (PIE) and safety testing. This paper presents the preliminary test details of the fuel performance, as measured by the control and acquisition software.

  3. Survival after failure of first-line chemotherapy in advanced gastric cancer patients: differences between Japan and the rest of the world.

    PubMed

    Takashima, Atsuo; Iizumi, Sakura; Boku, Narikazu

    2017-04-07

    In this review, we focus on post-progression survival after first-line chemotherapy of advanced gastric cancer, and particularly the differences between Japan and the rest of the world. We reviewed 15 recent phase III trials of which 4 were solely recruited from Japanese and 11 from rest of the world. The patient characteristics age, performance status, previous gastrectomy and the number of metastatic sites were similar in Japan and rest of the world. However, the diffuse histological type was more common in Japan. While overall survival was longer in Japan (10.5-14.1 vs. 7.9-12.2 months), progression-free survival tended to be shorter in Japan (3.6-6.0 vs. 3.1-7.4 months). Post-progression survival calculated as the difference between median overall survival and progression-free survival was clearly longer in Japan (6.9-8.6 vs. 2.4-6.2 months). The proportion of patients receiving second-line chemotherapy (%2nd-CX) was quite different in Japan and rest of the world (69-85% vs. 11-59%). Correlations between %2nd-CX and post-progression survival were strong (Spearman's rank correlation coefficient; ρ = 0.86, P < 0.001). Correlations between %2nd-CX and ratio of post-progression survival to total overall survival were also strong (ρ = 0.84, P < 0.001). Because a survival benefit of second-CX was documented in several phase III trials, it can be concluded that higher %2nd-CX partly contributed to extended post-progression survival. However, considering that second-CX increased survival only by ~1.5 months at median, other factors such as third-line chemotherapy may have some influences to prolonged post-progression survival.

  4. Necessity of re-evaluation of estramustine phosphate sodium (EMP) as a treatment option for first-line monotherapy in advanced prostate cancer.

    PubMed

    Kitamura, T

    2001-02-01

    Estramustine phosphate sodium (EMP) was first introduced in the early 1970s for the treatment of prostate cancer, when EMP was supposed to have the dual effect of estrogenic activity and cytotoxicity. For the following decades, it was used mainly in hormone-refractory cases, with a conventional dosage of 4-9 capsules/day, which showed a 30-35% objective response rate. However, a very limited number of cases have been reported that used EMP as a first-line monotherapy in the conventional dosage. One study showed a response rate of 82%, which is at least as effective as conventional estrogen (diethylstilbestrol; DES) monotherapy. Nevertheless, EMP was almost abandoned for the treatment of prostate cancer because of severe adverse side-effects, especially in the cardiovascular system and gastrointestinal tract. Recently, two facts have become evident. First, EMP interferes with cellular microtubule dynamics but does not show alkylating effects. Second, EMP is able to produce a complex with calcium when dairy products are taken concomitantly with EMP, resulting in a decrease in the absorption rate of EMP from the gut. Many clinical trials have been undertaken without warning against concomitant dairy product intake since the introduction of EMP. This fact will jeopardize almost all the clinical trials performed before 1990. It is considered that response rates have been underestimated and better results could have been obtained because side-effects decrease dose-dependently. Low-dose EMP monotherapy (2 capsules/day) has been performed infrequently in previously untreated advanced prostate cancer. The only large trial by the European Organization for Research and Treatment of Cancer in 1984 was biased in selecting patients. Nevertheless, the response rate of EMP is comparable to that of DES. In this study, the adverse side-effects of EMP were less than that of DES. Recently, a study was conducted at the University of Tokyo of 11 patients with advanced prostate cancer on

  5. EDITORIAL: Close contact Close contact

    NASA Astrophysics Data System (ADS)

    Demming, Anna

    2010-07-01

    The development of scanning probe techniques, such as scanning tunnelling microscopy [1], has often been touted as the catalyst for the surge in activity and progress in nanoscale science and technology. Images of nanoscale structural detail have served as an invaluable investigative resource and continue to fascinate with the fantastical reality of an intricate nether world existing all around us, but hidden from view of the naked eye by a disparity in scale. As is so often the case, the invention of the scanning tunnelling microscope heralded far more than just a useful new apparatus, it demonstrated the scope for exploiting the subtleties of electronic contact. The shrinking of electronic devices has been a driving force for research into molecular electronics, in which an understanding of the nature of electronic contact at junctions is crucial. In response, the number of experimental techniques in molecular electronics has increased rapidly in recent years. Scanning tunnelling microscopes have been used to study electron transfer through molecular films on a conducting substrate, and the need to monitor the contact force of scanning tunnelling electrodes led to the use of atomic force microscopy probes coated in a conducting layer as studied by Cui and colleagues in Arizona [2]. In this issue a collaboration of researchers at Delft University and Leiden University in the Netherlands report a new device architecture for the independent mechanical and electrostatic tuning of nanoscale charge transport, which will enable thorough studies of molecular transport in the future [3]. Scanning probes can also be used to pattern surfaces, such as through spatially-localized Suzuki and Heck reactions in chemical scanning probe lithography. Mechanistic aspects of spatially confined Suzuki and Heck chemistry are also reported in this issue by researchers in Oxford [4]. All these developments in molecular electronics fabrication and characterization provide alternative

  6. Fabrication of surfaces with extremely high contact angle hysteresis from polyelectrolyte multilayer.

    PubMed

    Wang, Liming; Wei, Jingjing; Su, Zhaohui

    2011-12-20

    High contact angle hysteresis on polyelectrolyte multilayers (PEMs) ion-paired with hydrophobic perfluorooctanoate anions is reported. Both the bilayer number of PEMs and the ionic strength of deposition solutions have significant influence on contact angle hysteresis: higher ionic strength and greater bilayer number cause increased contact angle hysteresis values. The hysteresis values of ~100° were observed on smooth PEMs and pinning of the receding contact line on hydrophilic defects is implicated as the cause of hysteresis. Surface roughness can be used to further tune the contact angle hysteresis on the PEMs. A surface with extremely high contact angle hysteresis of 156° was fabricated when a PEM was deposited on a rough substrate coated with submicrometer scale silica spheres. It was demonstrated that this extremely high value of contact angle hysteresis resulted from the penetration of water into the rough asperities on the substrate. The same substrate hydrophobized by chemical vapor deposition of 1H,1H,2H,2H-perfluorooctyltriethoxysilane exhibits high advancing contact angle and low hysteresis.

  7. Nintedanib in combination with docetaxel for second-line treatment of advanced non-small-cell lung cancer; GENESIS-SEFH drug evaluation report.

    PubMed

    Espinosa Bosch, María; Asensi Diez, Rocío; García Agudo, Sara; Clopes Estela, Ana

    2016-06-01

    Nintedanib is a triple angiokinase inhibitor that has been approved by the European Agency Medicines (EMA) in combination with docetaxel for the treatment of adult patients with locally advanced, metastatic or locally recurrent non small cell lung cancer (NSCLC) of adenocarcinoma tumour histology, after first-line chemotherapy. In LUME-Lung 1 clinical trial, the combination of nintedanib plus docetaxel vs. placebo plus docetaxel improved progression free survival (PFS) in NSCLC patients, and improved overall survival in the population of adenocarcinoma patients, particularly in those with progression within 9 months after first line treatment initiation, median 10.9 months ( [95% CI 8.5-12.6] vs. 7.9 months [6.7-9.1]; HR 0.75 [95% CI 0.60-0.92], p=0.0073). The toxicity profile of the combination included a higher incidence of neutropenia, gastro-intestinal (GI) disorders, and liver enzyme elevations; however, this did not cause a detrimental effect on patient quality of life. According to data from the clinical trial mentioned, the addition of nintedanib to docetaxel would lead to an estimated incremental cost-effectiveness ratio (ICER) per year of life with PFS in the overall population of 134,274.47 € (notified price). In the adenocarcinoma population per each life of year gained (LYG), the ICER of adding nintedanib to docetaxel would be 40,886.14 €; while by implementing a sensitivity analysis with a 25% discount in the drug price, the cost per LYG would be 32,364.05 €, and would place it close to the threshold of cost-effectiveness usually considered acceptable in our setting. In view of efficacy and safety results the proposed positioning is to recommend its inclusion in the Hospital Formulary only for adult patients with metastatic or locally recurrent NSCLC with adenocarcinoma histology after first line chemotherapy, with progression < 9 months from the initiation of first line treatment, taking into account the inclusion and exclusion criteria in the

  8. INKJET PRINTING OF NICKEL AND SILVER METAL SOLAR CELL CONTACTS

    SciTech Connect

    Pasquarelli, R.; Curtis, C.; Van Hest, M.

    2008-01-01

    With about 125,000 terawatts of solar power striking the earth at any given moment, solar energy may be the only renewable energy resource with enough capacity to meet a major portion of our future energy needs. Thin-fi lm technologies and solution deposition processes seek to reduce manufacturing costs in order to compete with conventional coal-based electricity. Inkjet printing, as a derivative of the direct-write process, offers the potential for low-cost, material-effi cient deposition of the metals for photovoltaic contacts. Advances in contact metallizations are important because they can be employed on existing silicon technology and in future-generation devices. We report on the atmospheric, non-contact deposition of nickel (Ni) and silver (Ag) metal patterns on glass, Si, and ZnO substrates at 180–220°C from metal-organic precursor inks using a Dimatix inkjet printer. Near-bulk conductivity Ag contacts were successfully printed up to 4.5 μm thick and 130 μm wide on the silicon nitride antirefl ective coating of silicon solar cells. Thin, high-resolution Ni adhesion-layer lines were printed on glass and zinc oxide at 80 μm wide and 55 nm thick with a conductivity two orders of magnitude less than the bulk metal. Additionally, the ability to print multi-layered metallizations (Ag on Ni) on transparent conducting oxides was demonstrated and is promising for contacts in copper-indium-diselenide (CIS) solar cells. Future work will focus on further improving resolution, printing full contact devices, and investigating copper inks as a low-cost replacement for Ag contacts.

  9. Contact angle measurements under thermodynamic equilibrium conditions.

    PubMed

    Lages, Carol; Méndez, Eduardo

    2007-08-01

    The precise control of the ambient humidity during contact angle measurements is needed to obtain stable and valid data. For a such purpose, a simple low-cost device was designed, and several modified surfaces relevant to biosensor design were studied. Static contact angle values for these surfaces are lower than advancing contact angles published for ambient conditions, indicating that thermodynamic equilibrium conditions are needed to avoid drop evaporation during the measurements.

  10. A randomized, multicenter, phase III study of gemcitabine combined with capecitabine versus gemcitabine alone as first-line chemotherapy for advanced pancreatic cancer in South Korea

    PubMed Central

    Lee, Hee Seung; Chung, Moon Jae; Park, Jeong Youp; Bang, Seungmin; Park, Seung Woo; Kim, Ho Gak; Noh, Myung Hwan; Lee, Sang Hyub; Kim, Yong-Tae; Kim, Hyo Jung; Kim, Chang Duck; Lee, Dong Ki; Cho, Kwang Bum; Cho, Chang Min; Moon, Jong Ho; Kim, Dong Uk; Kang, Dae Hwan; Cheon, Young Koog; Choi, Ho Soon; Kim, Tae Hyeon; Kim, Jae Kwang; Moon, Jieun; Shin, Hye Jung; Song, Si Young

    2017-01-01

    Abstract Background: This phase III trial compared the efficacy and safety of gemcitabine plus capecitabine (GemCap) versus single-agent gemcitabine (Gem) in advanced pancreatic cancer as first-line chemotherapy. Methods: A total of 214 advanced pancreatic cancer patients were enrolled from 16 hospitals in South Korea between 2007 and 2011. Patients were randomly assigned to receive GemCap (oral capecitabine 1660 mg/m2 plus Gem 1000 mg/m2 by 30-minute intravenous infusion weekly for 3 weeks followed by a 1-week break every 4 weeks) or Gem (by 30-minute intravenous infusion weekly for 3 weeks every 4 weeks). Results: Median overall survival (OS) time, the primary end point, was 10.3 and 7.5 months in the GemCap and Gem arms, respectively (P = 0.06). Progression-free survival was 6.2 and 5.3 months in the GemCap and Gem arms, respectively (P = 0.08). GemCap significantly improved overall response rate compared with Gem alone (43.7% vs 17.6%; P = 0.001). Overall frequency of grade 3 or 4 toxicities was similar in each group. Neutropenia was the most frequent grade 3 or 4 toxicity in both groups. Conclusion: GemCap failed to improve OS at a statistically significant level compared to Gem treatment. This study showed a trend toward improved OS compared to Gem alone. GemCap and Gem both exhibited similar safety profiles. PMID:28072706

  11. Our experiences with erlotinib in second and third line treatment patients with advanced stage IIIB/ IV non-small cell lung cancer.

    PubMed

    Mehić, Bakir; Stanetić, Mirko; Tinjić, Ljuljeta; Smoljanović, Vlatka

    2008-11-01

    HeadHER1/EGFR is known to play a pivotal role in tumorigenesis and is overexpressed in up to 80% of NSCLCs. The study of an Expanded Access Clinical Program of Erlotinib in NSCLC is a phase IV open-label, non-randomized, multicenter trial in patients with advanced (inoperable stage IIIb/IV) NSCLC who were eligible for treatment with erlotinib but had no access to trial participation. Patients for the study from Bosnia and Herzegovina (B&H) were selected from two Clinical centres (Sarajevo and Banja Luka). The aim of study was to evaluated efficacy and tolerability of erlotinib monotherapy in this setting. All patients who received at least one dose of erlotinib and data were entered in the database as of the CRF cut-off date of 14th May 2008 were included in analysis of data (n = 19). This population is defined as the Intent to Treat (ITT) population and includes all patients who had at least one dose of erlotinib regardless of whether major protocol violations were incurred. The findings are consistent with the results of the randomized, placebo-controlled BR.21 study. Indicating that erlotinib is an effective option for patients with advanced NSCLC who are unsuitable for, or who have previously failed standard chemotherapy. In B&H group of patients DCR was almost 84%, and PFS was approximately 24,7 weeks (compared with 44% and 9,7 weeks for erlotinib reported in phase III). Almost three quarter of the patients received erlotinib as their second line of therapy. Overall, erlotinib was well tolerated; there were no patients who withdrew due to a treatment-related AE (mainly rash) and there were few dose reductions. 24% of patients experienced an SAE (most commonly gastrointestinal (GI) disorders).

  12. A pharmaco-economic analysis of second-line treatment with imatinib or sunitinib in patients with advanced gastrointestinal stromal tumours

    PubMed Central

    Contreras-Hernández, I; Mould-Quevedo, J F; Silva, A; Salinas-Escudero, G; Villasís-Keever, M A; Granados-García, V; Dávila-Loaiza, G; Petersen, J A; Garduño-Espinosa, J

    2008-01-01

    Second-line treatments recommended by the National Cancer Center Network to manage advanced-stage gastrointestinal stromal tumours (GIST) were evaluated to determine the cost and cost-effectiveness of each intervention in the Mexican insurance system, the Instituto Mexicano del Seguro Social (IMSS). Treatments examined over a 5-year temporal horizon to estimate long-term costs included 800 mg day−1 of imatinib mesylate, 50 mg day−1 of sunitinib malate (administered in a 4 week on/2 week rest schedule), and palliative care. The mean cost (MC), cost-effectiveness, and benefit of each intervention were compared to determine the best GIST treatment from the institutional perspective of the IMSS. As sunitinib was not reimbursed at the time of the study, a Markov model and sensitivity analysis were conducted to predict the MC and likelihood of reimbursement. Patients taking 800 mg day−1 of imatinib had the highest MC (±s.d.) of treatment at $35 225.61 USD (±1253.65 USD); while sunitinib incurred a median MC of $17 805.87 USD (±694.83 USD); and palliative care had the least MC over treatment duration as the cost was $2071.86 USD (±472.88 USD). In comparison to palliative care, sunitinib is cost-effective for 38.9% of patients; however, sunitinib delivered the greatest survival benefit as 5.64 progression-free months (PFM) and 1.4 life-years gained (LYG) were obtained in the economic model. Conversely, patients on imatinib and palliative care saw a lower PFM of 5.28 months and 2.58 months and also fewer LYG (only 1.31 and 1.08 years, respectively). Therefore, economic modeling predicts that reimbursing sunitinib over high dose imatinib in the second-line GIST indication would deliver cost savings to the IMSS and greater survival benefits to patients. PMID:18506179

  13. A pharmaco-economic analysis of second-line treatment with imatinib or sunitinib in patients with advanced gastrointestinal stromal tumours.

    PubMed

    Contreras-Hernández, I; Mould-Quevedo, J F; Silva, A; Salinas-Escudero, G; Villasís-Keever, M A; Granados-García, V; Dávila-Loaiza, G; Petersen, J A; Garduño-Espinosa, J

    2008-06-03

    Second-line treatments recommended by the National Cancer Center Network to manage advanced-stage gastrointestinal stromal tumours (GIST) were evaluated to determine the cost and cost-effectiveness of each intervention in the Mexican insurance system, the Instituto Mexicano del Seguro Social (IMSS). Treatments examined over a 5-year temporal horizon to estimate long-term costs included 800 mg day(-1) of imatinib mesylate, 50 mg day(-1) of sunitinib malate (administered in a 4 week on/2 week rest schedule), and palliative care. The mean cost (MC), cost-effectiveness, and benefit of each intervention were compared to determine the best GIST treatment from the institutional perspective of the IMSS. As sunitinib was not reimbursed at the time of the study, a Markov model and sensitivity analysis were conducted to predict the MC and likelihood of reimbursement. Patients taking 800 mg day(-1) of imatinib had the highest MC (+/-s.d.) of treatment at $35,225.61 USD (+/-1253.65 USD); while sunitinib incurred a median MC of $17,805.87 USD (+/-694.83 USD); and palliative care had the least MC over treatment duration as the cost was $2071.86 USD (+/-472.88 USD). In comparison to palliative care, sunitinib is cost-effective for 38.9% of patients; however, sunitinib delivered the greatest survival benefit as 5.64 progression-free months (PFM) and 1.4 life-years gained (LYG) were obtained in the economic model. Conversely, patients on imatinib and palliative care saw a lower PFM of 5.28 months and 2.58 months and also fewer LYG (only 1.31 and 1.08 years, respectively). Therefore, economic modeling predicts that reimbursing sunitinib over high dose imatinib in the second-line GIST indication would deliver cost savings to the IMSS and greater survival benefits to patients.

  14. Fine mapping of complex traits in non-model species: using next generation sequencing and advanced intercross lines in Japanese quail

    PubMed Central

    2012-01-01

    Background As for other non-model species, genetic analyses in quail will benefit greatly from a higher marker density, now attainable thanks to the evolution of sequencing and genotyping technologies. Our objective was to obtain the first genome wide panel of Japanese quail SNP (Single Nucleotide Polymorphism) and to use it for the fine mapping of a QTL for a fear-related behaviour, namely tonic immobility, previously localized on Coturnix japonica chromosome 1. To this aim, two reduced representations of the genome were analysed through high-throughput 454 sequencing: AFLP (Amplified Fragment Length Polymorphism) fragments as representatives of genomic DNA, and EST (Expressed Sequence Tag) as representatives of the transcriptome. Results The sequencing runs produced 399,189 and 1,106,762 sequence reads from cDNA and genomic fragments, respectively. They covered over 434 Mb of sequence in total and allowed us to detect 17,433 putative SNP. Among them, 384 were used to genotype two Advanced Intercross Lines (AIL) obtained from three quail lines differing for duration of tonic immobility. Despite the absence of genotyping for founder individuals in the analysis, the previously identified candidate region on chromosome 1 was refined and led to the identification of a candidate gene. Conclusions These data confirm the efficiency of transcript and AFLP-sequencing for SNP discovery in a non-model species, and its application to the fine mapping of a complex trait. Our results reveal a significant association of duration of tonic immobility with a genomic region comprising the DMD (dystrophin) gene. Further characterization of this candidate gene is needed to decipher its putative role in tonic immobility in Coturnix. PMID:23066875

  15. Optimizing Training Population Size and Genotyping Strategy for Genomic Prediction Using Association Study Results and Pedigree Information. A Case of Study in Advanced Wheat Breeding Lines

    PubMed Central

    Jahoor, Ahmed; Orabi, Jihad; Andersen, Jeppe R.; Janss, Luc L.; Jensen, Just

    2017-01-01

    Wheat breeding programs generate a large amount of variation which cannot be completely explored because of limited phenotyping throughput. Genomic prediction (GP) has been proposed as a new tool which provides breeding values estimations without the need of phenotyping all the material produced but only a subset of it named training population (TP). However, genotyping of all the accessions under analysis is needed and, therefore, optimizing TP dimension and genotyping strategy is pivotal to implement GP in commercial breeding schemes. Here, we explored the optimum TP size and we integrated pedigree records and genome wide association studies (GWAS) results to optimize the genotyping strategy. A total of 988 advanced wheat breeding lines were genotyped with the Illumina 15K SNPs wheat chip and phenotyped across several years and locations for yield, lodging, and starch content. Cross-validation using the largest possible TP size and all the SNPs available after editing (~11k), yielded predictive abilities (rGP) ranging between 0.5–0.6. In order to explore the Training population size, rGP were computed using progressively smaller TP. These exercises showed that TP of around 700 lines were enough to yield the highest observed rGP. Moreover, rGP were calculated by randomly reducing the SNPs number. This showed that around 1K markers were enough to reach the highest observed rGP. GWAS was used to identify markers associated with the traits analyzed. A GWAS-based selection of SNPs resulted in increased rGP when compared with random selection and few hundreds SNPs were sufficient to obtain the highest observed rGP. For each of these scenarios, advantages of adding the pedigree information were shown. Our results indicate that moderate TP sizes were enough to yield high rGP and that pedigree information and GWAS results can be used to greatly optimize the genotyping strategy. PMID:28081208

  16. Identifying Differences and Similarities in Static and Dynamic Contact Angles between Nanoscale and Microscale Textured Surfaces Using Molecular Dynamics Simulations.

    PubMed

    Slovin, Mitchell R; Shirts, Michael R

    2015-07-28

    We quantify some of the effects of patterned nanoscale surface texture on static contact angles, dynamic contact angles, and dynamic contact angle hysteresis using molecular dynamics simulations of a moving Lennard-Jones droplet in contact with a solid surface. We observe static contact angles that change with the introduction of surface texture in a manner consistent with theoretical and experimental expectations. However, we find that the introduction of nanoscale surface texture at the length scale of 5-10 times the fluid particle size does not affect dynamic contact angle hysteresis even though it changes both the advancing and receding contact angles significantly. This result differs significantly from microscale experimental results where dynamic contact angle hysteresis decreases with the addition of surface texture due to an increase in the receding contact angle. Instead, we find that molecular-kinetic theory, previously applied only to nonpatterned surfaces, accurately describes dynamic contact angle and dynamic contact angle hysteresis behavior as a function of terminal fluid velocity. Therefore, at length scales of tens of nanometers, the kinetic phenomena such as contact line pinning observed at larger scales become insignificant in comparison to the effects of molecular fluctuations for moving droplets, even though the static properties are essentially scale-invariant. These findings may have implications for the design of highly hierarchical structures with particular wetting properties. We also find that quantitatively determining the trends observed in this article requires the careful selection of system and analysis parameters in order to achieve sufficient accuracy and precision in calculated contact angles. Therefore, we provide a detailed description of our two-surface, circular-fit approach to calculating static and dynamic contact angles on surfaces with nanoscale texturing.

  17. Sunitinib Plus Paclitaxel Versus Bevacizumab Plus Paclitaxel for First-Line Treatment of Patients With Advanced Breast Cancer: A Phase III, Randomized, Open-Label Trial

    PubMed Central

    Robert, Nicholas J.; Saleh, Mansoor N.; Paul, Devchand; Generali, Daniele; Gressot, Laurent; Copur, Mehmet S.; Brufsky, Adam M.; Minton, Susan E.; Giguere, Jeffrey K.; Smith, John W.; Richards, Paul D.; Gernhardt, Diana; Huang, Xin; Liau, Katherine F.; Kern, Kenneth A.; Davis, John

    2015-01-01

    Introduction A multicenter, open-label phase III study was conducted to test whether sunitinib plus paclitaxel prolongs progression-free survival (PFS) compared with bevacizumab plus paclitaxel as first-line treatment for patients with HER2− advanced breast cancer. Patients and Methods Patients with HER2− advanced breast cancer who were disease free for ≥ 12 months after adjuvant taxane treatment were randomized (1:1; planned enrollment 740 patients) to receive intravenous (I.V.) paclitaxel 90 mg/m2 every week for 3 weeks in 4-week cycles plus either sunitinib 25 to 37.5 mg every day or bevacizumab 10 mg/kg I.V. every 2 weeks. Results The trial was terminated early because of futility in reaching the primary endpoint as determined by the independent data monitoring committee during an interim futility analysis. At data cutoff, 242 patients had been randomized to sunitinib-paclitaxel and 243 patients to bevacizumab-paclitaxel. Median PFS was shorter with sunitinib-paclitaxel (7.4 vs. 9.2 months; hazard ratio [HR] 1.63 [95% confidence interval (CI), 1.18–2.25]; 1-sided P = .999). At a median follow-up of 8.1 months, with 79% of sunitinib-paclitaxel and 87% of bevacizumab-paclitaxel patients alive, overall survival analysis favored bevacizumab-paclitaxel (HR 1.82 [95% CI, 1.16–2.86]; 1-sided P = .996). The objective response rate was 32% in both arms, but median duration of response was shorter with sunitinib-paclitaxel (6.3 vs. 14.8 months). Bevacizumab-paclitaxel was better tolerated than sunitinib-paclitaxel. This was primarily due to a high frequency of grade 3/4, treatment-related neutropenia with sunitinib-paclitaxel (52%) precluding delivery of the prescribed doses of both drugs. Conclusion The sunitinib-paclitaxel regimen evaluated in this study was clinically inferior to the bevacizumab-paclitaxel regimen and is not a recommended treatment option for patients with advanced breast cancer. PMID:21569994

  18. Dynamic contact angles and hysteresis under electrowetting-on-dielectric.

    PubMed

    Nelson, Wyatt C; Sen, Prosenjit; Kim, Chang-Jin C J

    2011-08-16

    By designing and implementing a new experimental method, we have measured the dynamic advancing and receding contact angles and the resulting hysteresis of droplets under electrowetting-on-dielectric (EWOD). Measurements were obtained over wide ranges of applied EWOD voltages, or electrowetting numbers (0 ≤ Ew ≤ 0.9), and droplet sliding speeds, or capillary numbers (1.4 × 10(-5) ≤ Ca ≤ 6.9 × 10(-3)). If Ew or Ca is low, dynamic contact angle hysteresis is not affected much by the EWOD voltage or the sliding speed; that is, the hysteresis increases by less than 50% with a 2 order-of-magnitude increase in sliding speed when Ca < 10(-3). If both Ew and Ca are high, however, the hysteresis increases with either the EWOD voltage or the sliding speed. Stick-slip oscillations were observed at Ew > 0.4. Data are interpreted with simplified hydrodynamic (Cox-Voinov) and molecular-kinetic theory (MKT) models; the Cox-Voinov model captures the trend of the data, but it yields unreasonable fitting parameters. MKT fitting parameters associated with the advancing contact line are reasonable, but a lack of symmetry indicates that a more intricate model is required.

  19. Novel analytical approach to monitoring advanced glycosylation end products in human serum with on-line spectrophotometric and spectrofluorometric detection in a flow system.

    PubMed

    Wróbel, K; Wróbel, K; Garay-Sevilla, M E; Nava, L E; Malacara, J M

    1997-09-01

    We proposed a simple analytical procedure for measurement of serum advanced glycosylation end products (AGEs) based on simultaneous detection of low-molecular-mass peptides and AGEs with a flow system and two detectors connected on-line: spectrophotometric for peptides (lambda = 280 nm) and spectrofluorometric for AGEs (lambda ex = 247 nm, lambda em = 440 nm). Sample pretreatment was carried out in microcentrifuge tubes: Serum (20 microL) was deproteinized with trichloroacetic acid (480 microL, 0.15 mol/L) and lipids were extracted with chloroform (100 microL). Twenty microliters of the filtered aqueous layer was injected to the flow system and the relation between fluorescence and absorption signals was measured. A peptide-derived AGE calibrator was used for calibration. Within-day and between-day CVs were 6.7% and 9.1%, respectively, at an AGE concentration corresponding approximately to that in healthy individuals. Mean results (+/-SD) in 10 healthy individuals were 10.1% +/- 1.0%, in 21 patients with diabetes without complications 18.0% +/- 6.2%, in 25 patients with complications 24.1% +/- 15.4%, and in 12 diabetic patients in end-stage renal disease 92% +/- 30%. Comparison with an ELISA procedure (x, in arbitrary units/L) yields a regression equation y = 0.713x + 1.24 (Sy [symbol: see text] x = 6777, r = 0.8477, n = 41).

  20. Unilateral cleft lip/nose repair using an equal bows /straight line advancement technique - A preliminary report and postoperative symmetry-based anthropometry.

    PubMed

    Hakim, Samer George; Aschoff, Horst Heinrich; Jacobsen, Hans-Christian; Sieg, Peter

    2014-04-01

    In the evolution of cleft lip repair there has been continuous attempt to minimize local trauma, improve lip and nasal appearance and, especially, prevent conspicuous scars. The surgical technique presented meets these criteria, resulting in an appropriate scar course in children with a specific philtral ridge shape. Postoperative digital anthropometry was performed in 18 patients who underwent unilateral cleft lip repair using the equal bows/straight line advancement technique and in matched healthy control individuals. Symmetry values were assessed for lip length, philtral ridge length, vermilion height, width of the alar base, nasocanthal length, circumference of the nostrils, nostril width and height in both cleft and control groups. Evaluation revealed no significant differences in the symmetry values between cleft patients and control group (lip length: p = 0.71, philtral ridge length: p = 0.52, vermilion height: p = 0.23, alar base width: p = 0.69, nasocanthal length: p = 0.25, nostril circumference: p = 0.17, nostril width: p = 0.34, nostril height: p = 0.33). Principles of cleft lip repair can be achieved using the described technique which provides adequate lip length and natural nasal appearance in patients with a parallel-shaped philtral ridge.

  1. Fine-mapping quantitative trait loci affecting murine external ear tissue regeneration in the LG/J by SM/J advanced intercross line

    PubMed Central

    Cheverud, J M; Lawson, H A; Bouckaert, K; Kossenkov, A V; Showe, L C; Cort, L; Blankenhorn, E P; Bedelbaeva, K; Gourevitch, D; Zhang, Y; Heber-Katz, E

    2014-01-01

    External ear hole closure in LG/J mice represents a model of regenerative response. It is accompanied by the formation of a blastema-like structure and the re-growth of multiple tissues, including cartilage. The ability to regenerate tissue is heritable. An F34 advanced intercross line of mice (Wustl:LG,SM-G34) was generated to identify genomic loci involved in ear hole closure over a 30-day healing period. We mapped 19 quantitative trait loci (QTL) for ear hole closure. Individual gene effects are relatively small (0.08 mm), and most loci have co-dominant effects with phenotypically intermediate heterozygotes. QTL support regions were limited to a median size of 2 Mb containing a median of 19 genes. Positional candidate genes were evaluated using differential transcript expression between LG/J and SM/J healing tissue, function analysis and bioinformatic analysis of single-nucleotide polymorphisms in and around positional candidate genes of interest. Analysis of the set of 34 positional candidate genes and those displaying expression differences revealed over-representation of genes involved in cell cycle regulation/DNA damage, cell migration and adhesion, developmentally related genes and metabolism. This indicates that the healing phenotype in LG/J mice involves multiple physiological mechanisms. PMID:24569637

  2. Retrospective Study of Pegaspargase, Gemicitabine, Oxaliplatin and Dexamethasone (Peg-GemOD) as a First-Line Therapy for Advanced-Stage Extranodal NK/T Cell Lymphoma.

    PubMed

    Yao, Yi-Yun; Tang, Yong; Zhuang, Yan; Zou, Li-Fang; Dou, Hong-Ju; Wang, Lei; Zhu, Qi

    2017-03-01

    This study was conducted to retrospectively investigate the efficacy and safety of pegaspargase, gemicitabine, oxaliplatin and dexamethasone (Peg-GemOD) combination chemotherapy as a first-line therapy for advanced-stage extranodal NK/T cell lymphoma (ENKTL). Eighteen patients with newly diagnosed stage III/IV ENKTL were subjected to 3-6 cycles of Peg-GemOD chemotherapy. After 3 cycles of therapy, the overall response rate was 67 % (12/18) with a complete response rate of 28 % (5/18) and a partial response rate of 39 % (7/18). The median overall survival (OS) and progression-free survival (PFS) time were 10 and 8.5 months respectively. For those responders, the median OS and PFS time were significantly better than those of non-responders (median OS, 15 vs. 10 months; P = 0.001 and median PFS, 15 vs. 7 months; P = 0.001). Furthermore, patients with low plasma EBV-DNA levels after induction chemotherapy had a remarkably longer OS and PFS time. The toxicity of Peg-GemOD regimen was acceptable.

  3. Contact Lens Risks

    MedlinePlus

    ... Health and Consumer Devices Consumer Products Contact Lenses Contact Lens Risks Share Tweet Linkedin Pin it More ... redness blurred vision swelling pain Serious Hazards of Contact Lenses Symptoms of eye irritation can indicate a ...

  4. Contact Lens Care

    MedlinePlus

    ... For Consumers Consumer Information by Audience For Women Contact Lens Care Share Tweet Linkedin Pin it More ... 1088, www.fda.gov/medwatch Learn More about Contact Lens Care Other Tips on Contact Lenses Decorative ...

  5. Prognostic and Predictive Factors in Patients with Advanced Penile Cancer Receiving Salvage (2nd or Later Line) Systemic Treatment: A Retrospective, Multi-Center Study

    PubMed Central

    Buonerba, Carlo; Di Lorenzo, Giuseppe; Pond, Gregory; Cartenì, Giacomo; Scagliarini, Sarah; Rozzi, Antonio; Quevedo, Fernando J.; Dorff, Tanya; Nappi, Lucia; Lanzetta, Gaetano; Pagliaro, Lance; Eigl, Bernhard J.; Naik, Gurudatta; Ferro, Matteo; Galdiero, Mariano; De Placido, Sabino; Sonpavde, Guru

    2016-01-01

    Introduction and objectives: Metastatic penile squamous cell carcinoma (PSCC) is associated with dismal outcomes with median overall survival (OS) of 6–12 months in the first-line and <6 months in the salvage setting. Given the rarity of this disease, randomized trials are difficult. Prognostic risk models may assist in rational drug development by comparing observed outcomes in nonrandomized phase II studies and retrospective data vs. predicted outcomes based on baseline prognostic factors in the context of historically used agents. In this retrospective study, we constructed a prognostic model in the salvage setting of PSCC patients receiving second or later line systemic treatment, and also explored differences in outcomes based on type of treatment. Materials and methods: We performed a chart review to identify patients with locally advanced unresectable or metastatic PSCC who received second or later line systemic treatment in centers from North America and Europe. The primary outcome was OS from initiation of treatment, with secondary outcomes being progression-free survival (PFS) and response rate (RR). OS was estimated using the Kaplan-Meier method. Cox proportional hazards regression was used to identify prognostic factors for outcomes using univariable and multivariable models. Results: Sixty-five patients were eligible. Seventeen of 63 evaluable patients had a response (27.0%, 95% confidence interval [CI] = 16.6–39.7%) and median OS and PFS were 20 (95% CI = 20–21) and 12 (95% CI = 12, 16) weeks, respectively. Visceral metastasis (VM) and hemoglobin (Hb) ≤ 10 gm/dl were consistently significant poor prognostic factors for both OS and PFS, and Hb was also prognostic for response. The 28 patients with neither risk factor had a median OS (95% CI) of 24 (20–40) weeks and 1-year (95% CI) OS of 13.7% (4.4–42.7%), while the 37 patients with 1 or 2 risk factors had median OS (95% CI) of 20 (16–20) weeks and 1-year (95% CI) OS of 6.7% (1.8–24

  6. Pose and motion from contact

    SciTech Connect

    Jia, Y.B.; Erdmann, M.

    1999-05-01

    In the absence of vision, grasping an object often relies on tactile feedback from the fingertips. As the finger pushes the object, the fingertip can feel the contact point move. If the object is known in advance, from this motion the finger may infer the location of the contact point on the object, and thereby, the object pose. This paper primarily investigates the problem of determining the pose (orientation and position) and motion (velocity and angular velocity) of a planar object with known geometry from such contact motion generated by pushing. A dynamic analysis of pushing yields a nonlinear system that relates through contact the object pose and motion to the finger motion. The contact motion on the fingertip thus encodes certain information about the object pose. Nonlinear observability theory is employed to show that such information is sufficient for the finger to observe not only the pose, but also the motion of the object. Therefore, a sensing strategy can be realized as an observer of the nonlinear dynamic system. Two observers are subsequently introduced. The first observer, based on the work of Gautheir, Hammouri, and Othman (1992), has its gain determined by the solution of a Lyapunov-like equation; it can be activated at any time instant during a push. The second observer, based on Newton`s method, solves for the initial (motionless) object pose from three intermediate contact points during a push. Under the Coulomb-friction model, the paper deals with support friction in the plane and/or contact friction between the finger and the object. Extensive simulations have been done to demonstrate the feasibility of the two observers. Preliminary experiments (with an Adept robot) have also been conducted. A contact sensor has been implemented using strain gauges.

  7. The comparison of outcomes from tyrosine kinase inhibitor monotherapy in second- or third-line for advanced non-small-cell lung cancer patients with wild-type or unknown EGFR status

    PubMed Central

    Sortino, Giovanni; Celesia, Claudia; Passiglia, Francesco; Savio, Giuseppina; Laudani, Agata; Russo, Alessandro; Picone, Antonio; Rizzo, Sergio; De Tursi, Michele; Gambale, Elisabetta; Bazan, Viviana; Natoli, Clara; Blasi, Livio; Adamo, Vincenzo; Russo, Antonio

    2016-01-01

    Background Second-line treatment for advanced non-small-cell lung cancer (NSCLC) patients includes monotherapy with a third-generation cytotoxic drug (CT) or a tyrosine kinase inhibitor (TKI). These options are the actual standard for EGFR wild-type (WT) status, as patients with EGFR mutations achieve greater benefit by the use of TKI in first-line treatment. Some clinical trials and meta-analyses investigated the comparison between CT and TKI in second-line, but data are conflicting. Methods We designed a retrospective trial to gather information about TKI sensitivity in comparison with CT. We selected from clinical records patients treated with at least 1 line of CT and at least 1 line of TKI. We collected data about age, sex, performance status, comorbidity, smoking status, histotype, metastatic sites, EGFR status, treatment schedule, better response and time-to-progression (TTP) for each line of treatment and overall survival (OS). Results 93 patients met selection criteria. Mean age 66,7 (range: 46–84). M/F ratio is 3:1. 39 EGFR-WT and 54 EGFR-UK. All patients received erlotinib or gefitinib as second-line treatment or erlotinib as third-line treatment. No TTP differences were observed for both second-line (HR:0,91; p = 0,6333) and third-line (HR:1.1; p = 0,6951) treatment (TKI vs CT). A trend of a benefit in OS in favor of 3rd-line TKI (HR:0,68; p = 0,11). Conclusions This study explores the role of TKIs in EGFR non-mutated NSCLC patients. OS analysis highlights a trend to a benefit in patients who received TKI in third-line, even if this result is statistically non-significant. Further analysis are needed to find an explanation for this observation. PMID:26993607

  8. Costs of adverse events associated with erlotinib or afatinib in first-line treatment of advanced EGFR-positive non-small cell lung cancer

    PubMed Central

    Isla, Dolores; De Castro, Javier; Juan, Oscar; Grau, Santiago; Orofino, Javier; Gordo, Rocío; Rubio-Terrés, Carlos; Rubio-Rodríguez, Darío

    2017-01-01

    Objectives Epidermal growth factor receptor–tyrosine kinase inhibitors (EGFR-TKIs) are an established treatment for advanced non-small cell lung cancer (NSCLC) with EGFR mutation. According to published meta-analyses, no significant efficacy differences have been demonstrated between erlotinib and afatinib. However, the incidence of EGFR–TKI-related adverse events (AEs) was lower with erlotinib. This study compares the cost of management of the AEs associated with these two drugs from the perspective of the Spanish National Health System (NHS). Methods The frequency of AEs was established from a recently published meta-analysis. In Spain, the daily cost of both drugs can be considered similar; as a result, only the costs of management of the AEs were considered. Costs and resource utilization in the management of the AEs were estimated by a panel of Spanish oncologists and from studies previously carried out in Spain. A probabilistic analysis was performed based on a Monte Carlo simulation. Results The model generated 1,000 simulations. The total cost per patient treated with erlotinib and afatinib was €657.44 and €1,272.15, respectively. With erlotinib, the cost per patient and per AE of grades ≤2 and ≥3 was €550.86 and €106.58, respectively, whereas the cost with afatinib was €980.63 and €291.52, respectively. The reduction in the number of AEs with erlotinib could avoid a mean cost for the NHS of €614.71 (95% CI: €342.57–881.29) per patient. Conclusion In advanced EGFR mutation-positive NSCLC patients, first-line treatment with erlotinib could reduce health care costs for the NHS, due to a decrease in the AE rate compared with afatinib. In long-term treatments, the avoidance of complications and the lowering of costs associated with the management of AEs are relevant factors that contribute to the sustainability of the health system. PMID:28115857

  9. A Phase II Study of Gemcitabine, Vincristine, and Cisplatin (Gvp) As Second-Line Treatment for Patients with Advanced Soft Tissue Sarcoma

    PubMed Central

    Luo, Zhiguo; Zhang, Xiaowei; Peng, Wei; Wu, Xianghua; Wang, Huijie; Yu, Hui; Wang, Jialei; Chang, Jianhua; Hong, Xiaonan

    2015-01-01

    Abstract Patients with advanced soft tissue sarcoma (aSTS) typically have a poor prognosis. Patients progressing to doxorubicin-based regimen have limited therapeutic options. Monotherapy with cytotoxic drugs appears to have only modest activity in the second-line setting. The purpose of this phase II study was to prospectively evaluate the safety and efficacy of combination regimen with gemcitabine, vincristine, and cisplatin (GVP) as a salvage treatment for patients with aSTS. Eligible patients were female with 18∼75 years old, and had aSTS that had progressed after 1 prior anthracyclines-based chemotherapy regimen. Patients were treated with 1,000 mg/m2 gemcitabine intravenously (IV) on days 1 and 8, 1.4 mg/m2 (max 2 mg) vincristine IV on day 1 and 25 mg/m2 cisplatin IV on days 1 through 3 every 21 days until disease progression, unacceptable toxicity or up to 6 cycles. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), over response rate (ORR) and safety. This trial was registered with www.clinicaltrials.gov (no. NCT01192633). A total of 26 patients with a median age 47 years (21–72) were recruited. ORR was 23.1% [1 complete response and 5 partial responses]. The median PFS and OS were 4.8 (95% CI, 0.1–9.5) months and 15.0 (95% CI, 6.1–23.9) months, respectively. Grade 3/4 hematologic toxicities included neutropenia (34.6%), leukopenia (23.1%), thrombocytopenia (11.5%) and anemia (3.8%). No febrile neutropenia and grade 3/4 non-hematologic toxicities occurred. The most frequent non-hematologic toxicities were nausea/vomiting (50.0%), fatigue (30.8%), and fever (11.5%). We conclude that GVP regimen is effective with a favorable safety profile as the second-line chemotherapy in aSTS patients, which warrants further investigation in a phase III study. PMID:26512574

  10. Contact Lenses for Vision Correction

    MedlinePlus

    ... Ophthalmologist Patient Stories Español Eye Health / Glasses & Contacts Contact Lenses Sections Contact Lenses for Vision Correction Proper ... to Know About Contact Lenses Colored Contact Lenses Contact Lenses for Vision Correction Written by: Kierstan Boyd ...

  11. The heritability of oxycodone reward and concomitant phenotypes in a LG/J × SM/J mouse advanced intercross line.

    PubMed

    Bryant, Camron D; Guido, Michael A; Kole, Loren A; Cheng, Riyan

    2014-07-01

    The rewarding property of opioids likely contributes to their abuse potential. Therefore, determining the genetic basis of opioid reward could aid in understanding the neurobiological mechanisms of opioid addiction, provided that it is a heritable trait. Here, we characterized the rewarding property of the widely abused prescription opioid oxycodone (OXY) in the conditioned place preference (CPP) assay using LG/J and SM/J parental inbred mouse strains and 17 parent-offspring families of a LG/J × SM/J F47 /F48 advanced intercross line (AIL). Following OXY training (5 mg/kg, i.p.), SM/J mice and AIL mice, but not LG/J mice, showed an increase in preference for the OXY-paired side, suggesting a genetic basis for OXY-CPP. SM/J mice showed greater locomotor activity than LG/J mice in response to both saline and OXY. LG/J, SM/J, and AIL mice all exhibited robust OXY-induced locomotor sensitization. Narrow-sense heritability (h(2) ) estimates of the phenotypes using linear regression and maximum likelihood estimation showed good agreement (r = 0.91). OXY-CPP was clearly not a heritable trait whereas drug-free- and OXY-induced locomotor activity and sensitization were significantly and sometimes highly heritable (h(2)  = 0.30-0.84). Interestingly, the number of transitions between the saline- and OXY-paired sides emerged as a reliably heritable trait following OXY training (h(2)  = 0.46-0.66) and could represent a genetic component of drug-seeking behavior. Thus, although OXY-CPP does not appear to be amenable to genome-wide quantitative trait locus mapping, this protocol will be useful for mapping other traits potentially relevant to opioid abuse.

  12. Early hormonal data from a multicentre phase II trial using transdermal oestrogen patches as first-line hormonal therapy in patients with locally advanced or metastatic prostate cancer

    PubMed Central

    Langley, Ruth E.; Godsland, Ian F.; Kynaston, Howard; Clarke, Noel W.; Rosen, Stuart D.; Morgan, Rachel C.; Pollock, Philip; Kockelbergh, Roger; Lalani, El-Nasir; Dearnaley, David; Parmar, Mahesh; Abel, Paul D.

    2008-01-01

    OBJECTIVE To assess the hormonal effects of Fem7® (Merck, KGaA, Darmstadt, Germany) 100 μg transdermal oestrogen patches on men undergoing first-line androgen-deprivation therapy for prostate cancer. PATIENTS AND METHODS PATCH is a multicentre, randomized, phase II trial for men with locally advanced or metastatic prostate cancer, comparing luteinizing hormone-releasing hormone agonist therapy with oestrogen patches. To assess the dosing schedule for the patches, as this was the first time that this brand of patch had been used in men, and to reassure patients and participating clinicians, the Independent Data Monitoring Committee agreed to early release of hormonal data from this study. RESULTS Oestradiol, testosterone and prostate-specific antigen (PSA) levels are presented for the first group of 14 patients who received the patches (with 1 withdrawal) and for whom there were ≥12 weeks of follow-up by March 2007. After 12 weeks, testosterone levels (nmol/L) in eight of the 13 patients were <1.7, two were 1.7–2 and three were >2. The median (range) serum oestradiol levels was 442 (52.1–1542) pmol/L and all patients had a PSA response, with eight having a PSA level of <4 ng/mL. CONCLUSION These results confirm that oestrogen patches produce castrate levels of testosterone and concomitant PSA responses. They also highlighted the potential differences between different brands of oestrogen patches, and the need to monitor hormonal response, toxicity and efficacy until more experience with oestrogen patches for this clinical indication is obtained. The number of patches recommended in the PATCH study has now been increased. PMID:18422771

  13. Glucagon-like peptide-1 counteracts the detrimental effects of Advanced Glycation End-Products in the pancreatic beta cell line HIT-T 15

    SciTech Connect

    Puddu, A.; Storace, D.; Durante, A.; Odetti, P.; Viviani, G.L.

    2010-07-30

    Research highlights: {yields} GLP-1 prevents AGEs-induced cell death. {yields} GLP-1 prevents AGEs-induced oxidative stress. {yields} GLP-1 ameliorated AGEs-induced cell dysfunction. {yields} GLP-1 attenuates AGEs-induced RAGE increment. {yields} GLP-1 counteracts AGEs-induced pancreatic cell death and dysfunction. -- Abstract: Advanced Glycation End-Products (AGEs), a group of compounds resulting from the non-enzymatic reaction of reducing sugars with the free amino group of proteins, are implicated in diabetic complications. We previously demonstrated that exposure of the pancreatic islet cell line HIT-T 15 to high concentrations of AGEs significantly decreases cell proliferation and insulin secretion, and affects transcription factors regulating insulin gene transcription. The glucagon-like peptide-1 (GLP-1) is an incretin hormone that increases proinsulin biosynthesis, stimulates insulin secretion, and improves pancreatic beta-cell viability. The aim of this work was to investigate the effects of GLP-1 on the function and viability of HIT-T 15 cells cultured with AGEs. HIT-T 15 cells were cultured for 5 days in presence of AGEs alone, or supplemented with 10 nmol/l GLP-1. Cell viability, insulin secretion, redox balance, and expression of the AGEs receptor (RAGE) were then determined. The results showed that GLP-1 protected beta cell against AGEs-induced cell death preventing both apoptosis and necrosis. Moreover, addition of GLP-1 to the AGEs culture medium restored the redox balance, improved the responsiveness to glucose, and attenuated AGEs-induced RAGE expression. These findings provide evidence that GLP-1 protects beta cells from the dangerous effects of AGEs.

  14. Salt deposition at particle contact points

    NASA Astrophysics Data System (ADS)

    Nie, Xiaodong; Evitts, Richard W.; Besant, Robert W.; Kennell, Glyn F.

    2015-09-01

    Caking may occur when granular potash fertilizer with a moisture content greater than 0.25 % (w/w) undergoes drying. Since cake strength is proportional to the mass of crystal deposited per unit volume near contact points (and other factors) the modelling of mass deposition near contact points is important. The Young-Laplace equation for the air-salt-solution interface is used to determine the geometry of a 2-D planar saline film between two cubic potash particles. A 2-D theoretical model is developed and applied for ion diffusion and deposition near the contact point during drying. The numerical predictions of ion diffusion in an initially saturated salt illustrate the transient spatial distribution of new KCl deposits along the solid surfaces near the contact line. These results indicate the average salt deposition commences at the air-liquid-solid intersection, where the liquid film is thinnest, and moves toward the particle contact point with increasing area averaged KCl deposits, causing the formation of crystal deposits and bridges near contact points. It is concluded that the average salt deposit height increases inversely with distance from the contact point and decreases with initial contact angle of the contact region, but the deposition is nearly independent of the evaporation or drying rate near each contact region. Caking strength depends on, among other parameters, the amount of salt deposition near contact points.

  15. Contact angle measurement on rough surfaces.

    PubMed

    Meiron, Tammar S; Marmur, Abraham; Saguy, I Sam

    2004-06-15

    A new method for the measurement of apparent contact angles at the global energy minimum on real surfaces has been developed. The method consists of vibrating the surface, taking top-view pictures of the drop, monitoring the drop roundness, and calculating the contact angle from the drop diameter and weight. The use of the new method has been demonstrated for various rough surfaces, all having the same surface chemistry. In order to establish the optimal vibration conditions, the proper ranges for the system parameters (i.e., drop volume, vibration time, frequency of vibration, and amplitude of vibration) were determined. The reliability of the method has been demonstrated by the fact that the ideal contact angles of all surfaces, as calculated from the Wenzel equation using the measured apparent contact angles, came out to be practically identical. This ideal contact angle has been compared with three methods of calculation from values of advancing and receding contact angles.

  16. Schottky barrier height tuning using P+ DSS for NMOS contact resistance reduction

    NASA Astrophysics Data System (ADS)

    Khaja, Fareen Adeni; Rao, K. V.; Ni, Chi-Nung; Muthukrishnan, Shankar; Lei, Jianxin; Darlark, Andrew; Peidous, Igor; Brand, Adam; Henry, Todd; Variam, Naushad

    2012-11-01

    Nickel silicide (NiSi) contacts are adopted in advanced CMOS technology nodes as they demonstrate several benefits such as low resistivity, low Si consumption and formation temperature. But a disadvantage of NiSi contacts is that they exhibit high electron Schottky barrier height (SBH), which results in high contact resistance (Rc) and reduces the NMOS drive current. To reduce SBH for NMOS, we used phosphorous (P) ion implantation into NiPt silicide with optimized anneal in order to form dopant segregated Schottky (DSS). Electrical characterization was performed using test structures such as Transmission Line Model, Cross-Bridge Kelvin Resistor, Van der Pauw and diodes to extract Rc and understand the effects of P+ DSS on ΦBn tuning. Material characterization was performed using SIMS, SEM and TEM analysis. We report ˜45% reduction in Rc over reference sample by optimizing ion implantation and anneal conditions (spike RTA, milli-second laser anneals (DSA)).

  17. Advance Control Measures & Programs

    EPA Pesticide Factsheets

    As areas develop their path forward or action plan, they should consider a variety of voluntary and mandatory measures and programs. The resources on this page can help, and participants are also encouraged to talk with their EPA Advance contact

  18. S-1-Based Chemotherapy versus Capecitabine-Based Chemotherapy as First-Line Treatment for Advanced Gastric Carcinoma: A Meta-Analysis

    PubMed Central

    Wang, Zhi-qiang; Zhang, Dong-sheng; Luo, Hui-yan; Qiu, Miao-zhen; Wang, Feng-hua; Ren, Chao; Zeng, Zhao-lei; Xu, Rui-hua

    2013-01-01

    Background Although both oral fluoropyrimidines were reported effective and safe, doubts exist about whether S-1 or capecitabine is more advantageous in advanced gastric carcinoma (AGC). Herein, we performed a meta-analysis to comprehensively compare the efficacy and safety of S-1-based chemotherapy versus capecitabine-based chemotherapy as first-line treatment for AGC. Methods PubMed/Medline, EmBase, Cochrane library, and China National Knowledge Infrastructure databases were searched for articles comparing S-1-based chemotherapy to capecitabine-based chemotherapy for AGC. Primary outcomes were overall response rate (ORR), time to progression (TTP), overall survival (OS), progression-free probability, and survival probability. Secondary outcomes were toxicities. Fixed-effects model were used and all the results were confirmed by random-effects model. Results Five randomized controlled trials and five cohort studies with 821 patients were included. We found equivalent ORR (38.3% vs. 39.1%, odds ratio [OR] 0.92, 95% confidence interval [CI] 0.69-1.24, P = 0.59), TTP (harzad ratio [HR] 0.98, 95% CI 0.82-1.16, P = 0.79), OS (HR 0.99, 95% CI 0.87-1.13, P = 0.91), progression-free probability (3-month OR 1.02, 95% CI 0.62-1.68, P = 0.94; 6-month OR 1.34, 95% CI 0.88-2.04, P = 0.18) and survival probability (0.5-year OR 0.90, 95% CI 0.61-1.31, P =0.57; 1-year OR 0.97, 95% CI 0.70- 1.33, P = 0.84; 2-year OR 1.15, 95% CI 0.61-2.17, P = 0.66). Equivalent grade 3 to 4 hematological and non-hematological toxicities were found except hand-foot syndrome was less prominent in S-1-based chemotherapy (0.3% vs. 5.9%, OR 0.19, 95% CI 0.06-0.56, P = 0.003). There’re no significant heterogeneity and publication bias. Cumulative analysis found stable time-dependent trend. Consistent results stratified by study design, age, regimen, cycle, country were observed. Conclusion S-1-based chemotherapy was associated with non-inferior antitumor efficacy and better safety profile, compared

  19. Inkjet printing of precisely defined features using contact-angle hysteresis.

    PubMed

    Soltman, Dan; Smith, Ben; Morris, S J S; Subramanian, Vivek

    2013-06-15

    Motivated by the process of inkjet printing of electronics, we study experimentally and theoretically the processes limiting the printing of sharply defined, equilibrium corners. Using a non-volatile ionic liquid, we inkjet print squares with rounded corners on a substrate of roughened, display-grade glass. We show experimentally that with increasing roughness, corner radius decreases, allowing more precisely defined features to be printed. To interpret these results in terms of contact-angle hysteresis (difference between the advancing and retreating contact angles θA and θR), we implement the following model with the Surface Evolver program. With drop volume fixed, we minimize drop surface energy subject to a prescribed contact line. We identify θA and θR as the minimum and maximum contact angles around the drop perimeter. We find that with decreasing corner fidelity, contact-angle hysteresis also decreases. We are thus able to infer θR from the corner radius of printed features. We conclude that increasing contact-angle hysteresis allows the printing of more precisely defined features.

  20. Contact Us about Asbestos

    EPA Pesticide Factsheets

    How to contact EPA for more information on asbestos, including state and regional contacts, EPA’s Asbestos Abatement/Management Ombudsman and the Toxic Substances Control Act (TSCA) Assistance Information Service (TSCA Hotline).

  1. Colored Contact Lens Dangers

    MedlinePlus

    ... Halloween Hazard: The Hidden Dangers of Buying Decorative Contact Lenses Without a Prescription Sep. 26, 2013 It ... the truth." Real People, Real Problems with Colored Contact Lenses Julian: Teenager Blinded In One Eye By ...

  2. 30 CFR 7.68 - Firing line terminals test.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... line terminals test. (a) Test procedures. (1) The contact resistance through each firing line terminal.... (1) The contact resistance shall not be greater than 1 ohm. (2) The No. 18 gauge wire shall...

  3. 30 CFR 7.68 - Firing line terminals test.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... line terminals test. (a) Test procedures. (1) The contact resistance through each firing line terminal.... (1) The contact resistance shall not be greater than 1 ohm. (2) The No. 18 gauge wire shall...

  4. 30 CFR 7.68 - Firing line terminals test.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... line terminals test. (a) Test procedures. (1) The contact resistance through each firing line terminal.... (1) The contact resistance shall not be greater than 1 ohm. (2) The No. 18 gauge wire shall...

  5. 30 CFR 7.68 - Firing line terminals test.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... line terminals test. (a) Test procedures. (1) The contact resistance through each firing line terminal.... (1) The contact resistance shall not be greater than 1 ohm. (2) The No. 18 gauge wire shall...

  6. Contact Lenses on Submarines

    DTIC Science & Technology

    2014-09-26

    NAVAL SUBMARINE MEDICAL RESEARCH LABORATORY SUBMARINE BASE, GROTON, CONN. REPORT NUMBER 1048 CONTACT LENSES ON SUBMARINES... CONTACT LENSES ON SUBMARINES by James F. Socks, CDR, MSC, USN NAVAL SUBMARINE MEDICAL RESEARCH LABORATORY REPORT NUMBER 1048 NAVAL MEDICAL RESEARCH...DRSCHLAB Approved for public release; distribution unlimited SUMMARY PAGE PROBLEM To determine the feasibility of wearing contact lenses aboard

  7. Glasses and Contact Lenses

    MedlinePlus

    ... dientes Video: Getting an X-ray Glasses and Contact Lenses KidsHealth > For Kids > Glasses and Contact Lenses Print A A A What's in this ... together the way they should. But eyeglasses or contact lenses, also called corrective lenses, can help most ...

  8. Contact angle hysteresis at the nanometer scale.

    PubMed

    Delmas, Mathieu; Monthioux, Marc; Ondarçuhu, Thierry

    2011-04-01

    Using atomic force microscopy with nonconventional carbon tips, the pinning of a liquid contact line on individual nanometric defects was studied. This mechanism is responsible for the occurrence of the contact angle hysteresis. The presence of weak defects which do not contribute to the hysteresis is evidenced for the first time. The dissipated energy associated with strong defects is also measured down to values in the range of kT, which correspond to defect sizes in the order of 1 nm.

  9. Diffuse interface simulation of ternary fluids in contact with solid

    NASA Astrophysics Data System (ADS)

    Zhang, Chun-Yu; Ding, Hang; Gao, Peng; Wu, Yan-Ling

    2016-03-01

    In this article we developed a geometrical wetting condition for diffuse-interface simulation of ternary fluid flows with moving contact lines. The wettability of the substrate in the presence of ternary fluid flows is represented by multiple contact angles, corresponding to the different material properties between the respective fluid and the substrate. Displacement of ternary fluid flows on the substrate leads to the occurrence of moving contact point, at which three moving contact lines meet. We proposed a weighted contact angle model, to replace the jump in contact angle at the contact point by a relatively smooth transition of contact angle over a region of 'diffuse contact point' of finite size. Based on this model, we extended the geometrical formulation of wetting condition for two-phase flows with moving contact lines to ternary flows with moving contact lines. Combining this wetting condition, a Navier-Stokes solver and a ternary-fluid model, we simulated two-dimensional spreading of a compound droplet on a substrate, and validated the numerical results of the drop shape at equilibrium by comparing against the analytical solution. We also checked the convergence rate of the simulation by investigating the axisymmetric drop spreading in a capillary tube. Finally, we applied the model to a variety of applications of practical importance, including impact of a circular cylinder into a pool of two layers of different fluids and sliding of a three-dimensional compound droplet in shear flows.

  10. Contact detection and contact motion for error recovery in the presence of uncertainties

    NASA Technical Reports Server (NTRS)

    Xiao, Jing

    1992-01-01

    Due to various kinds of uncertainties, a robot motion may fail and result in some unintended contact between the object held by the robot and the environment, which greatly hampers robotics applications on tasks with high-precision requirements, such as assembly tasks. Aiming at automatically recovering a robotic task from such a failure, this paper discusses, in the presence of uncertainties, contact detection based on contact motion for recovery. It presents a framework for on-line recognizing contacts using multiple sensor modalities in the presence of sensing uncertainties and means for ensuring successful compliant motions in the presence of sensing and control uncertainties.

  11. Contact lens in keratoconus

    PubMed Central

    Rathi, Varsha M; Mandathara, Preeji S; Dumpati, Srikanth

    2013-01-01

    Contact lenses are required for the visual improvement in patients with keratoconus. Various contact lens options, such as rigid gas permeable (RGP) lenses, soft and soft toric lenses, piggy back contact lenses (PBCL), hybrid lenses and scleral lenses are availble. This article discusses about selection of a lens depending on the type of keratoconus and the fitting philosophies of various contact lenses including the starting trial lens. A Medline search was carried out for articles in the English language with the keywords keratoconus and various contact lenses such as Rose k lens, RGP lens, hybrid lens, scleral lens and PBCL. PMID:23925325

  12. Evaluation of metal-nanowire electrical contacts by measuring contact end resistance

    NASA Astrophysics Data System (ADS)

    Park, Hongsik; Beresford, Roderic; Ha, Ryong; Choi, Heon-Jin; Shin, Hyunjung; Xu, Jimmy

    2012-06-01

    It is known, but often unappreciated, that the performance of nanowire (NW)-based electrical devices can be significantly affected by electrical contacts between electrodes and NWs, sometimes to the extent that it is really the contacts that determine the performance. To correctly understand and design NW device operation, it is thus important to carefully measure the contact resistance and evaluate the contact parameters, specific contact resistance and transfer length. A four-terminal pattern or a transmission line model (TLM) pattern has been widely used to measure contact resistance of NW devices and the TLM has been typically used to extract contact parameters of NW devices. However, the conventional method assumes that the electrical properties of semiconducting NW regions covered by a metal are not changed after electrode formation. In this study, we report that the conventional methods for contact evaluation can give rise to considerable errors because of an altered property of the NW under the electrodes. We demonstrate that more correct contact resistance can be measured from the TLM pattern rather than the four-terminal pattern and correct contact parameters including the effects of changed NW properties under electrodes can be evaluated by using the contact end resistance measurement method.

  13. Treatment options in advanced renal cell carcinoma after first-line treatment with vascular endothelial growth factor receptor tyrosine kinase inhibitors

    PubMed Central

    Basappa, Naveen S.

    2016-01-01

    Targeted therapy for metastatic renal cell carcinoma (mRCC) was introduced a decade ago and since then, a number of therapeutic options have been developed. Vascular endothelial growth factor-targeted therapy is the widely accepted first-line option for mRCC. After progression, treatment in the second-line setting has typically been with either axitinib or everolimus. However, with the advent of several new agents demonstrating efficacy in the second-line setting, including nivolumab, cabozantinib, and the combination of lenvatinib and everolimus, the treatment paradigm has shifted toward these novel therapies with improved patient outcomes. PMID:28096936

  14. Hertzian contact in two and three dimensions

    NASA Technical Reports Server (NTRS)

    Tripp, J. H.

    1985-01-01

    The basic solution to the problem of mechanical contact between elastically deforming solids was proposed by Hertz over a century ago and has been used by tribologists and others ever since in a steadily increasing number of applications. While the theoretical development is not conceptually difficult and treatments exist to suit all tastes, it is nonetheless interesting to trace the relationships among the solutions in different dimensions. Such an approach is used herein to shed light on the curious and sometimes perplexing behavior of line contacts. A number of the more frequently used contact expressions together as a convenient reference and for comparative purposes.

  15. Direct-Write Contacts: Metallization and Contact Formation; Preprint

    SciTech Connect

    van Hest, M. F. A. M.; Curtis, C. J.; Miedaner, A.; Pasquarelli, R. M.; Kaydonova, T.; Hersh, P.; Ginley, D. S.

    2008-05-01

    Using direct-write approaches in photovoltaics for metallization and contact formation can significantly reduce the cost per watt of producing photovoltaic devices. Inks have been developed for various materials, such as Ag, Cu, Ni and Al, which can be used to inkjet print metallizations for various kinds of photovoltaic devices. Use of these inks results in metallization with resistivities close to those of bulk materials. By means of inkjet printing a metallization grid can be printed with better resolution, i.e. smaller lines, than screen-printing. Also inks have been developed to deposit transparent conductive oxide films by means of ultrasonic spraying.

  16. Specific Contact Resistance Measurements of Ohmic Contacts to Diamond

    DTIC Science & Technology

    1991-01-01

    AD-A262 818 a.vi tm te (11o ckiaa AGENCY USE CNLY re.j. b"IAI 2 REPORT DATS 3 i4 ý’ * : ..... .. February 1993 l , qf-r 4 T71 a AND SUBT’LE. SPECIFIC...rectify rnq and :1 i diamondi tl- ’o *been reported in the- literature 1-I paper measurements, of the specitic conatact inccc o.f ohmic ln tacts to...conducting layer. The contact resistance in these struc- tures is analyzed using the transmission line model [15. The primary drawback to

  17. Molecular Modeling of Three Phase Contact for Static and Dynamic Contact Angle Phenomena

    NASA Astrophysics Data System (ADS)

    Malani, Ateeque; Amat, Miguel; Raghavanpillai, Anilkumar; Wysong, Ernest; Rutledge, Gregory

    2012-02-01

    Interfacial phenomena arise in a number of industrially important situations, such as repellency of liquids on surfaces, condensation, etc. In designing materials for such applications, the key component is their wetting behavior, which is characterized by three-phase static and dynamic contact angle phenomena. Molecular modeling has the potential to provide basic insight into the detailed picture of the three-phase contact line resolved on the sub-nanometer scale which is essential for the success of these materials. We have proposed a computational strategy to study three-phase contact phenomena, where buoyancy of a solid rod or particle is studied in a planar liquid film. The contact angle is readily evaluated by measuring the position of solid and liquid interfaces. As proof of concept, the methodology has been validated extensively using a simple Lennard-Jones (LJ) fluid in contact with an LJ surface. In the dynamic contact angle analysis, the evolution of contact angle as a function of force applied to the rod or particle is characterized by the pinning and slipping of the three phase contact line. Ultimately, complete wetting or de-wetting is observed, allowing molecular level characterization of the contact angle hysteresis.

  18. Pressure dependence of the contact angle.

    PubMed

    Wu, Jiyu; Farouk, T; Ward, C A

    2007-06-07

    When a liquid and its vapor contact a smooth, homogeneous surface, Gibbsian thermodynamics indicates that the contact angle depends on the pressure at the three-phase line of an isothermal system. When a recently proposed adsorption isotherm for a solid-vapor interface is combined with the equilibrium conditions and the system is assumed to be in a cylinder where the liquid-vapor interface can be approximated as spherical, the contact-angle-pressure relation can be made explicit. It indicates that a range of contact angles can be observed on a smooth homogeneous surface by changing the pressure at the three-phase line, but it also indicates that the adsorption at the solid-liquid interface is negative, and leads to the prediction that the contact angle increases with pressure. The predicted dependence of the contact angle on pressure is investigated experimentally in a system that has an independent mechanism for determining when thermodynamic equilibrium is reached. The predictions are in agreement with the measurements. The results provide a possible explanation for contact angle hysteresis.

  19. [Immunology of contact allergy].

    PubMed

    Martin, S F

    2011-10-01

    Contact allergy is a skin disease that is caused by the reaction of the immune system to low molecular weight chemicals. A hallmark of contact allergens is their chemical reactivity, which is not exhibited by toxic irritants. Covalent binding of contact allergens to or complex formation with proteins is essential for the activation of the immune system. As a consequence antigenic epitopes are formed, which are recognized by contact allergen-specific T cells. The generation of effector and memory T cells causes the high antigen specificity and the repeated antigen-specific skin reaction of contact allergy. New findings reveal that the less specific reaction of the innate immune system to contact allergens closely resembles the reaction to an infection. Therefore, contact allergy can be viewed as an immunologic misunderstanding since the skin contact with chemical allergens is interpreted as an infection. The growing understanding of the molecular and cellular pathologic mechanisms of contact allergy can aid the development of specific therapies and of in vitro alternatives to animal testing for the identification of contact allergens.

  20. Effects of dynamic contact angle on liquid infiltration into inclined capillary tubes: (semi)-analytical solutions.

    PubMed

    Hilpert, Markus

    2009-09-01

    In a recent paper, we generalized Washburn's analytical solution for capillary flow in a horizontally oriented tube by accounting for a dynamic contact angle. In this paper, we derive solutions for flow in inclined tubes that account for gravity. We again consider two general models for dynamic contact angle: the uncompensated Young force on the contact line depends on the capillary number in the form of (1) a power law with exponent beta, or (2) a polynomial. A dimensional analysis shows that, aside from the parameters for the model for the uncompensated Young force, the problem is defined through four nondimensional parameters: (1) the advancing equilibrium contact angle, (2) the initial contact angle, (3) a Bond number, and (4) nondimensional liquid pressure at the tube inlet relative to the constant gas pressure. For both contact angle models, we derive analytical solutions for the travel time of the gas-liquid interface as a function of interface velocity. The interface position as a function of travel time can be obtained through numerical integration. For the power law and beta=1 (an approximation of Cox's model for dynamic contact angle), we obtain an analytical solution for travel time as a function of interface position, as Washburn did for constant contact angle. Four different flow scenarios may occur: the interface moves (1) upward and approaches the height of capillary rise, (2) downward with the steady-state velocity, (3) downward while approaching the steady-state velocity from an initially higher velocity, or (4) downward while approaching the steady-state velocity from an initially smaller velocity.

  1. Non-contact measurement of contact wire

    NASA Astrophysics Data System (ADS)

    Yi, Yaxing; Ye, Xuemei; Li, Zhongke; Yue, Kaiduan

    2008-12-01

    The overhead contact system is the power supply unit of the electric locomotive. This article is to introduce our newly developed method to measure the height and pull out value of the contact wire. A carema dolly which can move on railway is applied to bear the weight of the measure equipment; two linear CCD cameras are installed on the dolly symmetrically about the midline of two rails. While the dolly move along the railway, two CCD cameras grasp the image synchronously, and a computer real-time process the images, the height and pull out value can be calculate out from the images.

  2. Effect of flow field and geometry on the dynamic contact angle.

    PubMed

    Lukyanov, A V; Shikhmurzaev, Y D

    2007-05-01

    A number of recent experiments suggest that, at a given wetting speed, the dynamic contact angle formed by an advancing liquid-gas interface with a solid substrate depends on the flow field and geometry near the moving contact line. In the present work, this effect is investigated in the framework of an earlier developed theory that was based on the fact that dynamic wetting is, by its very name, a process of formation of a new liquid-solid interface (newly "wetted" solid surface) and hence should be considered not as a singular problem but as a particular case from a general class of flows with forming or/and disappearing interfaces. The results demonstrate that, in the flow configuration of curtain coating, where a liquid sheet ("curtain") impinges onto a moving solid substrate, the actual dynamic contact angle indeed depends not only on the wetting speed and material constants of the contacting media, as in the so-called slip models, but also on the inlet velocity of the curtain, its height, and the angle between the falling curtain and the solid surface. In other words, for the same wetting speed the dynamic contact angle can be varied by manipulating the flow field and geometry near the moving contact line. The obtained results have important experimental implications: given that the dynamic contact angle is determined by the values of the surface tensions at the contact line and hence depends on the distributions of the surface parameters along the interfaces, which can be influenced by the flow field, one can use the overall flow conditions and the contact angle as a macroscopic multiparametric signal-response pair that probes the dynamics of the liquid-solid interface. This approach would allow one to investigate experimentally such properties of the interface as, for example, its equation of state and the rheological properties involved in the interface's response to an external torque, and would help to measure its parameters, such as the coefficient of

  3. Modelling of contact angle hysteresis on rough, non-uniform and superhydrophobic surfaces with lattice Boltzmann method

    NASA Astrophysics Data System (ADS)

    Kubiak, K. J.; Wilson, M. C. T.; Castrejón-Pita, J. R.; Hutchings, I. M.

    2011-11-01

    Contact Angle Hysteresis (CAH) is usually attributed to surface heterogeneity, contact line pinning, adsorption or interdiffusion. A model of CAH developed recently by Kubiak & Wilson is demonstrated using the lattice Boltzmann method. The model is based on the dynamic surface heterogeneity, reorientation of surface molecules under wetting liquid, physical roughness, chemical heterogeneity and liquid adhesion and evaporation. Once the surface is wetted, the local static contact angle (CA) changes from its advancing value to match the receding static CA over time Ta. When the contact line retracts, the surface recovers its initial properties corresponding to the advancing static CA over time period Te, which corresponds to the physical evaporation. Further development of the model to include surface roughness and chemical heterogeneity is presented. The model shows good agreement with experimental results for several practical configurations i.e. droplet impact and coalescence, drops on tilted surface, and drops on superhydrophobic and non-uniform surfaces etc. The extended model exhibits great potential for predictive modelling using the lattice Boltzmann method, but can be also implemented in other schemes. Research supported by EPSRC EP/F065019/1 and EP/H018913/1.

  4. Effect of surface texturing on superoleophobicity, contact angle hysteresis, and "robustness".

    PubMed

    Zhao, Hong; Park, Kyoo-Chul; Law, Kock-Yee

    2012-10-23

    Previously, we reported the creation of a fluorosilane (FOTS) modified pillar array silicon surface comprising ~3-μm-diameter pillars (6 μm pitch with ~7 μm height) that is both superhydrophobic and superoleophobic, with water and hexadecane contact angles exceeding 150° and sliding angles at ~10° owing to the surface fluorination and the re-entrant structure in the side wall of the pillar. In this work, the effects of surface texturing (pillar size, spacing, and height) on wettability, contact angle hysteresis, and "robustness" are investigated. We study the static, advancing, and receding contact angles, as well as the sliding angles as a function of the solid area fraction. The results reveal that pillar size and pillar spacing have very little effect on the static and advancing contact angles, as they are found to be insensitive to the solid area fraction from 0.04 to ~0.4 as the pillar diameter varies from 1 to 5 μm and the center-to-center spacing varies from 4.5 to 12 μm. On the other hand, sliding angle, receding contact angle, and contact angle hysteresis are found to be dependent on the solid area fraction. Specifically, receding contact angle decreases and sliding angle and hysteresis increase as the solid area fraction increases. This effect can be attributable to the increase in pinning as the solid area fraction increases. Surface Evolver modeling shows that water wets and pins the pillar surface whereas hexadecane wets the pillar surface and then penetrates into the side wall of the pillar with the contact line pinning underneath the re-entrant structure. Due to the penetration of the hexadecane drop into the pillar structure, the effect on the receding contact angle and hysteresis is larger relative to that of water. This interpretation is supported by studying a series of FOTS pillar array surfaces with varying overhang thickness. With the water drop, the contact line is pinned on the pillar surface and very little overhang thickness effect

  5. A Finite Element Method for Free-Surface Flows of Incompressible Fluids in Three Dimensions, Part II: Dynamic Wetting Lines

    SciTech Connect

    Baer, T.A.; Cairncross, R.A.; Rao, R.R.; Sackinger, P.A.; Schunk, P.R.

    1999-01-29

    To date, few researchers have solved three-dimensional free-surface problems with dynamic wetting lines. This paper extends the free-surface finite element method described in a companion paper [Cairncross, R.A., P.R. Schunk, T.A. Baer, P.A. Sackinger, R.R. Rao, "A finite element method for free surface flows of incompressible fluid in three dimensions, Part I: Boundary-Fitted mesh motion.", to be published (1998)] to handle dynamic wetting. A generalization of the technique used in two dimensional modeling to circumvent double-valued velocities at the wetting line, the so-called kinematic paradox, is presented for a wetting line in three dimensions. This approach requires the fluid velocity normal to the contact line to be zero, the fluid velocity tangent to the contact line to be equal to the tangential component of web velocity, and the fluid velocity into the web to be zero. In addition, slip is allowed in a narrow strip along the substrate surface near the dynamic contact line. For realistic wetting-line motion, a contact angle which varies with wetting speed is required because contact lines in three dimensions typically advance or recede a different rates depending upon location and/or have both advancing and receding portions. The theory is applied to capillary rise of static fluid in a corner, the initial motion of a Newtonian droplet down an inclined plane, and extrusion of a Newtonian fluid from a nozzle onto a moving substrate. The extrusion results are compared to experimental visualization. Subject Categories

  6. [Periorbital contact eczema].

    PubMed

    Worm, M; Sterry, W

    2005-11-01

    Periorbital contact eczema is most commonly the result of an allergic contact dermatitis whereas other eczematous skin diseases like atopic eczema or seborrheic eczema occur less frequently. Also, other diseases like autoimmune disorders or rosacea need to be considered. Allergic contact dermatitis is a T-cell-mediated immunological response towards ubiquitous contact allergens. Activated T-cells migrate through the vessels into the skin and produce several inflammatory mediators. Epicutaneous patch testing is an important tool for the diagnosis of contact allergy whereby the allergens are analysed in terms of their ability to induce eczematous skin reaction. Until now the short-term use of corticosteroids are is employed for the treatment of allergic contact eczema. Modern substances with an optimal therapeutic index should rather be used.

  7. Dynamic contact angle of water-based titanium oxide nanofluid.

    PubMed

    Radiom, Milad; Yang, Chun; Chan, Weng Kong

    2013-06-11

    This paper presents an investigation into spreading dynamics and dynamic contact angle of TiO2-deionized water nanofluids. Two mechanisms of energy dissipation, (1) contact line friction and (2) wedge film viscosity, govern the dynamics of contact line motion. The primary stage of spreading has the contact line friction as the dominant dissipative mechanism. At the secondary stage of spreading, the wedge film viscosity is the dominant dissipative mechanism. A theoretical model based on combination of molecular kinetic theory and hydrodynamic theory which incorporates non-Newtonian viscosity of solutions is used. The model agreement with experimental data is reasonable. Complex interparticle interactions, local pinning of the contact line, and variations in solid-liquid interfacial tension are attributed to errors.

  8. Dynamic contact angle of water-based titanium oxide nanofluid

    PubMed Central

    2013-01-01

    This paper presents an investigation into spreading dynamics and dynamic contact angle of TiO2-deionized water nanofluids. Two mechanisms of energy dissipation, (1) contact line friction and (2) wedge film viscosity, govern the dynamics of contact line motion. The primary stage of spreading has the contact line friction as the dominant dissipative mechanism. At the secondary stage of spreading, the wedge film viscosity is the dominant dissipative mechanism. A theoretical model based on combination of molecular kinetic theory and hydrodynamic theory which incorporates non-Newtonian viscosity of solutions is used. The model agreement with experimental data is reasonable. Complex interparticle interactions, local pinning of the contact line, and variations in solid–liquid interfacial tension are attributed to errors. PMID:23759071

  9. Soft contact lenses

    PubMed Central

    Sutherland, R. L.; VanLeeuwen, Wm. N.

    1972-01-01

    A series of 55 patients were fitted with a new type of hydrophilic soft contact lens. These were found more comfortable than hard contact lenses and they had a protective and pain-relieving action in cases of chronic corneal disease. Vision was not as good as with hard contact lenses and a greater potential danger of infection was found. They are preferred by many patients despite the noticeable thick edge and the difficulty of obtaining an identical replacement. PMID:5042887

  10. The Role of Orientation of Magnetic Fields in Contact Discontinuities

    NASA Astrophysics Data System (ADS)

    Tsai, T. C.; Hsieh, W. C.; Chao, J. K.

    2014-12-01

    Contact discontinuities are one type of the discontinuities in MHD plasma. Contact discontinuities are discontinuities with continuous magnetic fields but without plasma flows across a plasma density jump. Contact discontinuities are characterized by a remarkable plasma density jump but identical plasma bulk velocity, magnetic fields and thermal pressure on two sides of the discontinuity. Contact discontinuities are rarely observed in the nature. Due to a rapid diffusion of plasma along the continuous magnetic field lines across its surface, it is believed that contact discontinuities will rapidly broaden into a smooth transition then lose its identity. In this presentation, we study the effect of the orientation of magnetic field lines on the diffusion of plasma in contact discontinuities. With respect to the normal of a contact discontinuity, the cases of orientation of (1) parallel, (2) quasi-parallel, (3) perpendicular and (4) quasi-perpendicular magnetic fields are studied.

  11. Electrical contacts to nanocrystalline diamond films studied at high temperatures

    NASA Astrophysics Data System (ADS)

    Shimoda, Naotaka; Kato, Yoshimine; Teii, Kungen

    2016-12-01

    Electrical contacts of Ni, NiSi, Cu, Au, Al, and Ti electrodes to an n-type nanocrystalline diamond film are studied at temperatures between room temperature and 500 °C in a vacuum by the transmission line measurement. Direct current-voltage characteristics measured between pairs of electrodes on the film show almost straight lines, typical of ohmic contacts, for all kinds of electrode materials. The measured series resistance is divided into resistance of the film, resistance of the electrode, and the contact resistance between the electrode and film. The Ni electrode has the lowest contact resistance, which decreases from about 380 to 200 mΩ cm2 with temperature. The contact resistance accounts for a large portion of the total resistance at low temperatures. The results confirm that the contact resistance has a close relation with the work function of electrodes such that the larger the work function, the lower the contact resistance.

  12. Optical contact micrometer

    DOEpatents

    Jacobson, Steven D.

    2014-08-19

    Certain examples provide optical contact micrometers and methods of use. An example optical contact micrometer includes a pair of opposable lenses to receive an object and immobilize the object in a position. The example optical contact micrometer includes a pair of opposable mirrors positioned with respect to the pair of lenses to facilitate viewing of the object through the lenses. The example optical contact micrometer includes a microscope to facilitate viewing of the object through the lenses via the mirrors; and an interferometer to obtain one or more measurements of the object.

  13. Colors and contact dermatitis.

    PubMed

    Bonamonte, Domenico; Foti, Caterina; Romita, Paolo; Vestita, Michelangelo; Angelini, Gianni

    2014-01-01

    The diagnosis of skin diseases relies on several clinical signs, among which color is of paramount importance. In this review, we consider certain clinical presentations of both eczematous and noneczematous contact dermatitis in which color plays a peculiar role orientating toward the right diagnosis. The conditions that will be discussed include specific clinical-morphologic subtypes of eczematous contact dermatitis, primary melanocytic, and nonmelanocytic contact hyperchromia, black dermographism, contact chemical leukoderma, and others. Based on the physical, chemical, and biologic factors underlying a healthy skin color, the various skin shades drawing a disease picture are thoroughly debated, stressing their etiopathogenic origins and histopathologic aspects.

  14. Scheme for contact angle and its hysteresis in a multiphase lattice Boltzmann method.

    PubMed

    Wang, Lei; Huang, Hai-bo; Lu, Xi-Yun

    2013-01-01

    In this paper, a scheme for specifying contact angle and its hysteresis is incorporated into a multiphase lattice Boltzmann method. The scheme is validated through investigations of the dynamic behaviors of a droplet sliding along two kinds of walls: a smooth (ideal) wall and a rough or chemically inhomogeneous (nonideal) wall. For an ideal wall, the wettability of solid substrates is able to be prescribed. For a nonideal wall, arbitrary contact angle hysteresis can be obtained through adjusting advancing and receding angles. Significantly different phenomena can be recovered for the two kinds of walls. For instance, a droplet on an inclined ideal wall under gravity is impossible to stay stationary. However, the droplet on a nonideal wall may be pinned due to contact angle hysteresis. The steady interface shapes of the droplet on an inclined nonideal wall under gravity or in a shear flow quantitatively agree well with the previous numerical studies. Besides, the complex motion of a droplet creeping like an inchworm could be simulated. The scheme is found suitable for the study of contact line problems with and without contact angle hysteresis.

  15. Live cumulative network meta-analysis: protocol for second-line treatments in advanced non-small-cell lung cancer with wild-type or unknown status for epidermal growth factor receptor

    PubMed Central

    Créquit, Perrine; Trinquart, Ludovic; Ravaud, Philippe

    2016-01-01

    Introduction Many second-line treatments for advanced non-small-cell lung cancer (NSCLC) have been assessed in randomised controlled trials, but which treatments work the best remains unclear. Novel treatments are being rapidly developed. We need a comprehensive up-to-date evidence synthesis of all these treatments. We present the protocol for a live cumulative network meta-analysis (NMA) to address this need. Methods and analysis We will consider trials of second-line treatments in patients with advanced NSCLC with wild-type or unknown epidermal growth factor receptor status. We will consider any single agent of cytotoxic chemotherapy, targeted therapy, combination of cytotoxic chemotherapy and targeted therapy and any combination of targeted therapies. The primary outcomes will be overall survival and progression-free survival. The live cumulative NMA will be initiated with a NMA and then iterations will be repeated at regular intervals to keep the NMA up-to-date over time. We have defined the update frequency as 4 months, based on an assessment of the pace of evidence production on this topic. Each iteration will consist of six methodological steps: adaptive search for treatments and trials, screening of reports and selection of trials, data extraction, assessment of risk of bias, update of the network of trials and synthesis, and dissemination. We will set up a research community in lung cancer, with different groups of contributors of different skills. We will distribute tasks through online crowdsourcing. This proof-of-concept study in second-line treatments of advanced NSCLC will allow one for assessing the feasibility of live cumulative NMA and opening the path for this new form of synthesis. Ethics and dissemination Ethical approval is not required because our study will not include confidential participant data and interventions. The description of all the steps and the results of this live cumulative NMA will be available online. Trial registration

  16. A randomised phase II study of OSI-7904L versus 5-fluorouracil (FU)/leucovorin (LV) as first-line treatment in patients with advanced biliary cancers.

    PubMed

    Ciuleanu, T; Diculescu, M; Hoepffner, N M; Trojan, J; Sailer, V; Zalupski, M; Herrmann, T; Roth, A; Chick, J; Brock, K; Albert, D; Philip, P A

    2007-08-01

    The prognosis of advanced biliary tract carcinoma is poor with chemotherapy limited to a palliative role. This randomised study was designed to evaluate the effectiveness of a new liposomal thymidylate synthase inhibitor (TSI), OSI-7904L, in parallel with a modified de Gramont regimen of 5-FU/LV in patients with advanced biliary cancer. Patients with previously untreated advanced or metastatic carcinoma of the biliary tract were randomised to receive either OSI-7904L 12 mg/m2 intravenously every 21 days or a modified de Gramont schedule of 5-FU/LV (intravenous l-LV 200 mg/m2, bolus 5-FU 400 mg/m2 and a 46-h infusion of 5-FU 2,400 mg/m2) every 14 days. Twenty-two patients were randomised, 11 to each group. No patients responded in the OSI-7904L arm, while one patient achieved a partial response in the 5-FU/LV arm. The rates of disease stabilisation were 4/11 (OSI-7904L) and 10/11 (5-FU/LV). Both treatment arms were generally well tolerated. These results show that the activity of OSI-7904L is below a level of clinical relevance in advanced biliary tract cancer, providing only a small degree of disease stabilisation. A simplified de Gramont schedule appears to have marginally more activity. Both treatments were well tolerated.

  17. Can Imagined Interactions Produce Positive Perceptions?: Reducing Prejudice through Simulated Social Contact

    ERIC Educational Resources Information Center

    Crisp, Richard J.; Turner, Rhiannon N.

    2009-01-01

    The contact hypothesis states that, under the right conditions, contact between members of different groups leads to more positive intergroup relations. The authors track recent trends in contact theory to the emergence of extended, or indirect, forms of contact. These advances lead to an intriguing proposition: that simply imagining intergroup…

  18. Detection of the "cp4 epsps" Gene in Maize Line NK603 and Comparison of Related Protein Structures: An Advanced Undergraduate Experiment

    ERIC Educational Resources Information Center

    Swope, Nicole K.; Fryfogle, Patrick J.; Sivy, Tami L.

    2015-01-01

    A flexible, rigorous laboratory experiment for upper-level biochemistry undergraduates is described that focuses on the Roundup Ready maize line. The work is appropriate for undergraduate laboratory courses that integrate biochemistry, molecular biology, or bioinformatics. In this experiment, DNA is extracted and purified from maize kernel and…

  19. Factor XII Contact Activation.

    PubMed

    Naudin, Clément; Burillo, Elena; Blankenberg, Stefan; Butler, Lynn; Renné, Thomas

    2017-03-27

    Contact activation is the surface-induced conversion of factor XII (FXII) zymogen to the serine protease FXIIa. Blood-circulating FXII binds to negatively charged surfaces and this contact to surfaces triggers a conformational change in the zymogen inducing autoactivation. Several surfaces that have the capacity for initiating FXII contact activation have been identified, including misfolded protein aggregates, collagen, nucleic acids, and platelet and microbial polyphosphate. Activated FXII initiates the proinflammatory kallikrein-kinin system and the intrinsic coagulation pathway, leading to formation of bradykinin and thrombin, respectively. FXII contact activation is well characterized in vitro and provides the mechanistic basis for the diagnostic clotting assay, activated partial thromboplastin time. However, only in the past decade has the critical role of FXII contact activation in pathological thrombosis been appreciated. While defective FXII contact activation provides thromboprotection, excess activation underlies the swelling disorder hereditary angioedema type III. This review provides an overview of the molecular basis of FXII contact activation and FXII contact activation-associated disease states.

  20. Noneczematous Contact Dermatitis

    PubMed Central

    Foti, Caterina; Vestita, Michelangelo; Angelini, Gianni

    2013-01-01

    Irritant or allergic contact dermatitis usually presents as an eczematous process, clinically characterized by erythematoedematovesicous lesions with intense itching in the acute phase. Such manifestations become erythematous-scaly as the condition progresses to the subacute phase and papular-hyperkeratotic in the chronic phase. Not infrequently, however, contact dermatitis presents with noneczematous features. The reasons underlying this clinical polymorphism lie in the different noxae and contact modalities, as well as in the individual susceptibility and the various targeted cutaneous structures. The most represented forms of non-eczematous contact dermatitis include the erythema multiforme-like, the purpuric, the lichenoid, and the pigmented kinds. These clinical entities must obviously be discerned from the corresponding “pure” dermatitis, which are not associated with contact with exogenous agents. PMID:24109520

  1. Contact angle hysteresis, adhesion, and marine biofouling.

    PubMed

    Schmidt, Donald L; Brady, Robert F; Lam, Karen; Schmidt, Dale C; Chaudhury, Manoj K

    2004-03-30

    Adhesive and marine biofouling release properties of coatings containing surface-oriented perfluoroalkyl groups were investigated. These coatings were prepared by cross-linking a copolymer of 1H,1H,2H,2H-heptadecafluorodecyl acrylate and acrylic acid with a copolymer of poly(2-isopropenyl-2-oxazoline) and methyl methacrylate at different molar ratios. The relationships between contact angle, contact angle hysteresis, adhesion, and marine biofouling were studied. Adhesion was determined by peel tests using pressure-sensitive adhesives. The chemical nature of the surfaces was studied by using X-ray photoelectron spectroscopy. Resistance to marine biofouling of an optimized coating was studied by immersion in seawater and compared to previous, less optimized coatings. The adhesive release properties of the coatings did not correlate well with the surface energies of the coatings estimated from the static and advancing contact angles nor with the amount of fluorine present on the surface. The adhesive properties of the surfaces, however, show a correlation with water receding contact angles and contact angle hysteresis (or wetting hysteresis) resulting from surface penetration and surface reconstruction. Coatings having the best release properties had both the highest cross-link density and the lowest contact angle hysteresis. An optimized coating exhibited unprecedented resistance to marine biofouling. Water contact angle hysteresis appears to correlate with marine biofouling resistance.

  2. Toward patient-specific articular contact mechanics

    PubMed Central

    Ateshian, Gerard A.; Henak, Corinne R.; Weiss, Jeffrey A.

    2015-01-01

    The mechanics of contacting cartilage layers is fundamentally important to understanding the development, homeostasis and pathology of diarthrodial joints. Because of the highly nonlinear nature of both the materials and the contact problem itself, numerical methods such as the finite element method are typically incorporated to obtain solutions. Over the course of five decades, we have moved from an initial qualitative understanding of articular cartilage material behavior to the ability to perform complex, three-dimensional contact analysis, including multiphasic material representations. This history includes the development of analytical and computational contact analysis methods that now provide the ability to perform highly nonlinear analyses. Numerical implementations of contact analysis based on the finite element method are rapidly advancing and will soon enable patient-specific analysis of joint contact mechanics using models based on medical image data. In addition to contact stress on the articular surfaces, these techniques can predict variations in strain and strain through the cartilage layers, providing the basis to predict damage and failure. This opens up exciting areas for future research and application to patient-specific diagnosis and treatment planning applied to a variety of pathologies that affect joint function and cartilage homeostasis. PMID:25698236

  3. Contact angle and contact angle hysteresis measurements using the capillary bridge technique.

    PubMed

    Restagno, Frédéric; Poulard, Christophe; Cohen, Céline; Vagharchakian, Laurianne; Léger, Liliane

    2009-09-15

    A new experimental technique is proposed to easily measure both advancing and receding contact angles of a liquid on a solid surface, with unprecedented accuracy. The technique is based on the analysis of the evolution of a capillary bridge formed between a liquid bath and a solid surface (which needs to be spherical) when the distance between the surface and the liquid bath is slowly varied. The feasibility of the technique is demonstrated using a low-energy perfluorinated surface with two different test liquids (water and hexadecane). A detailed description of both experimental procedures and computational modeling are given, allowing one to determine contact angle values. It is shown that the origin of the high accuracy of this technique relies on the fact that the contact angles are automatically averaged over the whole periphery of the contact. This method appears to be particularly adapted to the characterization of surfaces with very low contact angle hysteresis.

  4. Contact angle hysteresis on polymer substrates established with various experimental techniques, its interpretation, and quantitative characterization.

    PubMed

    Bormashenko, Edward; Bormashenko, Yelena; Whyman, Gene; Pogreb, Roman; Musin, Albina; Jager, Rachel; Barkay, Zahava

    2008-04-15

    The effect of contact angle hysteresis (CAH) was studied on various polymer substrates with traditional and new experimental techniques. The new experimental technique presented in the article is based on the slow deformation of the droplet, thus CAH is studied under the constant volume of the drop in contrast to existing techniques when the volume of the drop is changed under the measurement. The energy of hysteresis was calculated in the framework of the improved Extrand approach. The advancing contact angle established with a new technique is in a good agreement with that measured with the needle-syringe method. The receding angles measured with three experimental techniques demonstrated a very significant discrepancy. The force pinning the triple line responsible for hysteresis was calculated.

  5. 2-D Simulations for Accurate Extraction of the Specific Contact Resistivity from Contact Resistance Data,

    DTIC Science & Technology

    1985-01-01

    Bridge Kelvin Resistor, the Contact End Resistor, and the Transmission pletely by its sheet resistance . We shall concentrate here on semiconduc- Line...Tap Resistor. For each particular structure, a wniversal set of curves tar to metal contacts. Since the metal sheet resistance is much lower than is...derived that allows accurate determination of V,, given the geometry Of diffusion sheet resistance , metal is considered to be an equipotential the

  6. Immediate Versus Delayed Treatment with EGFR Tyrosine Kinase Inhibitors after First-line Therapy in Advanced Non-small-cell Lung CANCER

    PubMed Central

    Wang, Zhi-jie; An, Tong-tong; Mok, Tony; Yang, Lu; Bai, Hua; Zhao, Jun; Duan, Jian-chun; Wu, Mei-na; Wang, Yu-yan; Li, Ping-ping; Sun, Hong; Yang, Ping; Wang, Jie

    2011-01-01

    Objective To analyze the outcomes of patients who received TKI immediately after the first-line without progression as maintenance treatment (immediate group) vs. those received delayed treatment upon disease progression as second-line therapy (delayed group). Methods The study included 159 no-small-cell lung cancer (NSCLC) patients who received gefitinib or erlotinib as maintenance treatment in the immediate group (85 patients) or as second-line therapy in the delayed group (74 patients). The primary end point was progression-free survival (PFS). EGFR mutation status was detected using denaturing high-performance liquid chromatography (DHPLC). Results PFS was 17.3 and 16.4 months in the immediate and delayed groups, respectively (hazard ratio [HR], 0.99; 95% Confidence Interval [CI]: 0.69-1.42; P=0.947). In a subgroup analysis that included only patients with EGFR mutation, however, PFS was significantly longer in the immediate group than in the delayed group (HR, 0.48; 95% CI: 0.27-0.85; P=0.012). In patients with wild type EGFR, the risk for disease progression was comparable between the two groups (HR, 1.23; 95% CI: 0.61-2.51; P=0.564). No significant difference was demonstrated between the immediate and delayed group in terms of the overall survival (OS) (26.1 months vs. 21.6 months, respectively; HR=0.53; 95% CI: 0.27 to 1.06; P=0.072). There was also no difference in the incidence of adverse events between the two groups. Conclusions EGFR TKI maintenance improves PFS in patients with EGFR mutation. Prospectively designed clinical studies that compare TKI immediate vs. delayed treatment after first-line chemotherapy upon disease progression are needed. PMID:23483659

  7. AISI/DOE Advanced Process Control Program Vol. 4 of 6: ON-LINE, NON-DESTRUCTIVE MECHANICAL PROPERTY MEASUREMENT USING LASER-ULTRASOUND

    SciTech Connect

    Andre' Moreau; Martin Lord; Daniel Levesqure; Marc Dubois; Jean Bussiere; Jean-Pierre Monchalin; Christian Padioleau; Guy Lamouche; Teodor Veres; Martin Viens; Harold Hebert; Pierre Basseras; Cheng-Kuei Jen

    2001-03-31

    The goal of this project was to demonstrate the feasibility to measure the mechanical properties, such as yield strength, tensile strength, elongation, strain hardening exponent and plastic strain ratio parameters, of low carbon steel sheets on the production line using laser ultrasound. The ultrasound generated by the developed apparatus travels mostly back and forth in the thickness of the steel sheet. By measuring the time delay between two echoes, and the relative amplitude of these two echoes, one can measure ultrasound velocity and attenuation. These are governed by the microstructure: grain size, crystallographic texture, dislocations, etc. Thus, by recording the time behavior of the ultrasonic signal, one can extract microstructural information. These microstructural information together with the modified Hall-Petch equation allow measurement of the mechanical properties. Through laboratory investigations with a laboratory laser ultrasound system, followed by the installation of a prototype system at LTV Steel Company's No.1 Inspection Line in Cleveland, all target mechanical properties of ultra low carbon (ULC), low carbon (LC) and high strength low alloy (HSLA) steel sample lots were measured meeting or nearly meeting all the target accuracies. Thus, the project realized its goal to demonstrate that the mechanical properties of low carbon steel sheets can be measured on-line using laser ultrasound

  8. 90nm node contact hole patterning through applying model based OPC in KrF lithography

    NASA Astrophysics Data System (ADS)

    Jeon, Young-Doo; Lee, Sang-Uk; Choi, Jaeyoung; Kim, Jeahee; Han, Jaewon

    2008-03-01

    As semiconductor technologies move toward 90nm generation and below, contact hole is one of the most challenging features to print in the semiconductor manufacturing process. There are two principal difficulties in order to define small contact hole pattern on wafer. One is insufficient process margin besides poor resolution compared with line & space pattern. The other is that contact hole should be made through pitches and sometimes random contact hole pattern should be fabricated. Therefore advanced ArF lithography scanner should be used for small contact hole printing with RETs (Resolution Enhancement Techniques) such as immersion lithography, OPC(Optical Proximity Correction), PSM(Phase Shift Mask), high NA(Numerical Aperture), OAI(Off-Axis Illumination), SRAF(Sub-resolution Assistant Feature), mask biasing and thermal flow. Like this, ArF lithography propose the method of enhancing resolution, however, we must spend an enormous amount of CoC(cost of ownership) to utilize ArF photolithography process than KrF. In this paper, we suggest the method of contact holes patterning by using KrF lithography tool in 90nm sFlash(stand alone Flash)devices. For patterning of contact hole, we apply RETs which combine OAI and Model based OPC. Additionally, in this paper we present the result of hole pattern images which operate ArF lithography equipment. Also, this study describes comparison of two wafer images that ArF lithography process which is used mask biasing and Rule based OPC, KrF lithography process which is applied hybrid OPC.

  9. Allergic contact dermatitis.

    PubMed

    Becker, Detlef

    2013-07-01

    Allergic contact dermatitis is a frequent inflammatory skin disease. The suspected diagnosis is based on clinical symptoms, a plausible contact to allergens and a suitable history of dermatitis. Differential diagnoses should be considered only after careful exclusion of any causal contact sensitization. Hence, careful diagnosis by patch testing is of great importance. Modifications of the standardized test procedure are the strip patch test and the repeated open application test. The interpretation of the SLS (sodium lauryl sulfate) patch test as well as testing with the patients' own products and working materials are potential sources of error. Accurate patch test reading is affected in particular by the experience and individual factors of the examiner. Therefore, a high degree of standardization and continuous quality control is necessary and may be supported by use of an online patch test reading course made available by the German Contact Dermatitis Research Group. A critical relevance assessment of allergic patch test reactions helps to avoid relapses and the consideration of differential diagnoses. Any allergic test reaction should be documented in an allergy ID card including the INCI name, if appropriate. The diagnostics of allergic contact dermatitis is endangered by a seriously reduced financing of patch testing by the German statutory health insurances. Restrictive regulations by the German Drug Law block the approval of new contact allergens for routine patch testing. Beside the consistent avoidance of allergen contact, temporary use of systemic and topical corticosteroids is the therapy of first choice.

  10. Advanced Rotorcraft Transmission (ART) Program summary

    NASA Astrophysics Data System (ADS)

    Krantz, T. L.; Kish, J. G.

    1992-07-01

    The Advanced Rotorcraft Transmission (ART) Program was initiated to advance the state of the art for rotorcraft transmissions. The goal of the ART Program was to develop and demonstrate the technologies needed to reduce transmission weight by 25 pct and reduce noise by 10 dB while obtaining a 5000 hr 'mean time between failure'. The research done under the ART Program is summarized. A split path design was selected as best able to meet the program goals. Key part technologies needed for this design were identified, studied, and developed. Two of these technologies are discussed in detail: the load sharing of split path designs including the use of a compliant elastomeric torque splitter and the application of a high ratio, low pitch line velocity gear mesh. Development of an angular contact spherical roller bearing, transmission error analysis, and fretting fatigue testing are discussed. The technologies for a light weight, quiet, and reliable rotorcraft transmission were demonstrated.

  11. Advanced Rotorcraft Transmission (ART) program summary

    NASA Technical Reports Server (NTRS)

    Krantz, T. L.; Kish, J. G.

    1992-01-01

    The Advanced Rotorcraft Transmission (ART) Program was initiated to advance the state of the art for rotorcraft transmissions. The goal of the ART Program was to develop and demonstrate the technologies needed to reduce transmission weight by 25 pct. and reduce noise by 10 dB while obtaining a 5000 hr 'mean time between failure'. The research done under the ART Program is summarized. A split path design was selected as best able to meet the program goals. Key part technologies needed for this design were identified, studied, and developed. Two of these technologies are discussed in detail: the load sharing of split path designs including the use of a compliant elastomeric torque splitter and the application of a high ratio, low pitch line velocity gear mesh. Development of an angular contact spherical roller bearing, transmission error analysis, and fretting fatigue testing are discussed. The technologies for a light weight, quiet, and reliable rotorcraft transmission were demonstrated.

  12. Telescopic vision contact lens

    NASA Astrophysics Data System (ADS)

    Tremblay, Eric J.; Beer, R. Dirk; Arianpour, Ashkan; Ford, Joseph E.

    2011-03-01

    We present the concept, optical design, and first proof of principle experimental results for a telescopic contact lens intended to become a visual aid for age-related macular degeneration (AMD), providing magnification to the user without surgery or external head-mounted optics. Our contact lens optical system can provide a combination of telescopic and non-magnified vision through two independent optical paths through the contact lens. The magnified optical path incorporates a telescopic arrangement of positive and negative annular concentric reflectors to achieve 2.8x - 3x magnification on the eye, while light passing through a central clear aperture provides unmagnified vision.

  13. Optical contacting of quartz

    NASA Technical Reports Server (NTRS)

    Payne, L. L.

    1982-01-01

    The strength of the bond between optically contacted quartz surfaces was investigated. The Gravity Probe-B (GP-B) experiment to test the theories of general relativity requires extremely precise measurements. The quartz components of the instruments to make these measurements must be held together in a very stable unit. Optical contacting is suggested as a possible method of joining these components. The fundamental forces involved in optical contacting are reviewed and relates calculations of these forces to the results obtained in experiments.

  14. Lattice Boltzmann modeling of contact angle and its hysteresis in two-phase flow with large viscosity difference

    NASA Astrophysics Data System (ADS)

    Liu, Haihu; Ju, Yaping; Wang, Ningning; Xi, Guang; Zhang, Yonghao

    2015-09-01

    Contact angle hysteresis is an important physical phenomenon omnipresent in nature and various industrial processes, but its effects are not considered in many existing multiphase flow simulations due to modeling complexity. In this work, a multiphase lattice Boltzmann method (LBM) is developed to simulate the contact-line dynamics with consideration of the contact angle hysteresis for a broad range of kinematic viscosity ratios. In this method, the immiscible two-phase flow is described by a color-fluid model, in which the multiple-relaxation-time collision operator is adopted to increase numerical stability and suppress unphysical spurious currents at the contact line. The contact angle hysteresis is introduced using the strategy proposed by Ding and Spelt [Ding and Spelt, J. Fluid Mech. 599, 341 (2008), 10.1017/S0022112008000190], and the geometrical wetting boundary condition is enforced to obtain the desired contact angle. This method is first validated by simulations of static contact angle and dynamic capillary intrusion process on ideal (smooth) surfaces. It is then used to simulate the dynamic behavior of a droplet on a nonideal (inhomogeneous) surface subject to a simple shear flow. When the droplet remains pinned on the surface due to hysteresis, the steady interface shapes of the droplet quantitatively agree well with the previous numerical results. Four typical motion modes of contact points, as observed in a recent study, are qualitatively reproduced with varying advancing and receding contact angles. The viscosity ratio is found to have a notable impact on the droplet deformation, breakup, and hysteresis behavior. Finally, this method is extended to simulate the droplet breakup in a microfluidic T junction, with one half of the wall surface ideal and the other half nonideal. Due to the contact angle hysteresis, the droplet asymmetrically breaks up into two daughter droplets with the smaller one in the nonideal branch channel, and the behavior of

  15. Lattice Boltzmann modeling of contact angle and its hysteresis in two-phase flow with large viscosity difference.

    PubMed

    Liu, Haihu; Ju, Yaping; Wang, Ningning; Xi, Guang; Zhang, Yonghao

    2015-09-01

    Contact angle hysteresis is an important physical phenomenon omnipresent in nature and various industrial processes, but its effects are not considered in many existing multiphase flow simulations due to modeling complexity. In this work, a multiphase lattice Boltzmann method (LBM) is developed to simulate the contact-line dynamics with consideration of the contact angle hysteresis for a broad range of kinematic viscosity ratios. In this method, the immiscible two-phase flow is described by a color-fluid model, in which the multiple-relaxation-time collision operator is adopted to increase numerical stability and suppress unphysical spurious currents at the contact line. The contact angle hysteresis is introduced using the strategy proposed by Ding and Spelt [Ding and Spelt, J. Fluid Mech. 599, 341 (2008)JFLSA70022-112010.1017/S0022112008000190], and the geometrical wetting boundary condition is enforced to obtain the desired contact angle. This method is first validated by simulations of static contact angle and dynamic capillary intrusion process on ideal (smooth) surfaces. It is then used to simulate the dynamic behavior of a droplet on a nonideal (inhomogeneous) surface subject to a simple shear flow. When the droplet remains pinned on the surface due to hysteresis, the steady interface shapes of the droplet quantitatively agree well with the previous numerical results. Four typical motion modes of contact points, as observed in a recent study, are qualitatively reproduced with varying advancing and receding contact angles. The viscosity ratio is found to have a notable impact on the droplet deformation, breakup, and hysteresis behavior. Finally, this method is extended to simulate the droplet breakup in a microfluidic T junction, with one half of the wall surface ideal and the other half nonideal. Due to the contact angle hysteresis, the droplet asymmetrically breaks up into two daughter droplets with the smaller one in the nonideal branch channel, and the

  16. A modified Cassie-Baxter relationship to explain contact angle hysteresis and anisotropy on non-wetting textured surfaces.

    PubMed

    Choi, Wonjae; Tuteja, Anish; Mabry, Joseph M; Cohen, Robert E; McKinley, Gareth H

    2009-11-01

    The Cassie-Baxter model is widely used to predict the apparent contact angles obtained on composite (solid-liquid-air) superhydrophobic interfaces. However, the validity of this model has been repeatedly challenged by various research groups because of its inherent inability to predict contact angle hysteresis. In our recent work, we have developed robust omniphobic surfaces which repel a wide range of liquids. An interesting corollary of constructing such surfaces is that it becomes possible to directly image the solid-liquid-air triple-phase contact line on a composite interface, using an electron microscope with non-volatile organic liquids or curable polymers. Here, we fabricate a range of model superoleophobic surfaces with controlled surface topography in order to correlate the details of the local texture with the experimentally observed apparent contact angles. Based on these experiments, in conjunction with numerical simulations, we modify the classical Cassie-Baxter relation to include a local differential texture parameter which enables us to quantitatively predict the apparent advancing and receding contact angles, as well as contact angle hysteresis. This quantitative prediction also allows us to provide an a priori estimation of roll-off angles for a given textured substrate. Using this understanding we design model substrates that display extremely small or extremely large roll-off angles, as well as surfaces that demonstrate direction-dependent wettability, through a systematic control of surface topography and connectivity.

  17. The potential predictive role of nuclear NHERF1 expression in advanced gastric cancer patients treated with epirubicin/oxaliplatin/capecitabine first line chemotherapy

    PubMed Central

    Mangia, Anita; Caldarola, Lucia; Dell'Endice, Stefania; Scarpi, Emanuela; Saragoni, Luca; Monti, Manlio; Santini, Daniele; Brunetti, Oronzo; Simone, Giovanni; Silvestris, Nicola

    2015-01-01

    Cellular resistance in advanced gastric cancer (GC) might be related to function of multidrug resistance (MDR) proteins. The adaptor protein NHERF1 (Na+/H+ exchanger regulatory factor) is an important player in cancer progression for a number of solid malignancies, even if its role to develop drug resistance remains uncertain. Herein, we aimed to analyze the potential association between NHERF1 expression and P-gp, sorcin and HIF-1α MDR-related proteins in advanced GC patients treated with epirubicin/oxaliplatin/capecitabine (EOX) chemotherapy regimen, and its relation to response. Total number of 28 untreated patients were included into the study. Expression and subcellular localization of all proteins were assessed by immunohistochemistry on formalin-fixed paraffin embedded tumor samples. We did not found significant association between NHERF1 expression and the MDR-related proteins. A trend was observed between positive cytoplasmic NHERF1 (cNHERF1) expression and negative nuclear HIF-1α (nHIF-1α) expression (68.8% versus 31.3% respectively, P = 0.054). However, cytoplasmic P-gp (cP-gp) expression was positively correlated with both cHIF-1α and sorcin expression (P = 0.011; P = 0.002, respectively). Interestingly, nuclear NHERF1 (nNHERF1) staining was statistically associated with clinical response. In detail, 66.7% of patients with high nNHERF1 expression had a disease control rate, while 84.6% of subjects with negative nuclear expression of the protein showed progressive disease (P = 0.009). Multivariate analysis confirmed a significant correlation between nNHERF1 and clinical response (OR 0.06, P = 0.019). These results suggest that nuclear NHERF1 could be related to resistance to the EOX regimen in advanced GC patients, identifying this marker as a possible independent predictive factor. PMID:26126066

  18. Comparison of cisplatinum/paclitaxel with cisplatinum/5-fluorouracil as first-line therapy for nonsurgical locally advanced esophageal squamous cell carcinoma patients

    PubMed Central

    Hu, Guofang; Wang, Zhehai; Wang, Yuan; Zhang, Qingqing; Tang, Ning; Guo, Jun; Liu, Liyan; Han, Xiao

    2016-01-01

    Background To retrospectively evaluate the efficacy and toxicity of definitive concurrent chemoradiotherapy (dCRT) with cisplatinum/paclitaxel versus cisplatinum/5-fluorouracil in patients with locally advanced esophageal squamous cell carcinoma (ESCC) who received nonsurgical treatment. Methods This study retrospectively evaluated 202 patients with locally advanced ESCC treated at Shandong Cancer Hospital between January 2009 and December 2013. All the patients initially received dCRT, including platinum and paclitaxel or 5-fluorouracil, with concurrent 1.8 or 2 Gy/fraction radiation (total dose, 54–60 Gy). The patient population was divided into two treatment groups: 105 patients who received the cisplatinum/paclitaxel regimen were allocated to group A, and 97 patients who received the cisplatinum/5-fluorouracil regimen were allocated to group B. We compared the progression-free survival (PFS) and overall survival (OS) by various clinical variables, including prior treatment characteristics, major toxicities (mainly in grade 3 and 4 hematological), and response to dCRT. We used the receiver operating curve analysis to determine the optimal cutoff value of clinical stage and radiation dose. The Kaplan–Meier method was used for survival comparison and Cox regression for multivariate analysis. Results Median PFS and OS in group A were significantly better compared with group B (median PFS, 15.9 versus 13.0 months, P=0.016 and median OS, 33.9 versus 23.1 months, P=0.014, respectively). The 1- and 2-year survival rates of the two groups were 82.9% versus 76.3%, and 61.9% versus 47.6%, respectively. The complete response and response rate were 17.1% versus 7.2% (P=0.032) and 52.4% versus 30.9% (P=0.042) in group A and B, respectively. Meanwhile, group B was associated with a significantly lower rate of grade 3/4 overall toxicity than group A (P=0.039). Conclusion Our data showed that patients with locally advanced ESCC in group A had longer PFS and OS compared with

  19. Microscopic and Macroscopic Dynamic Interface Shapes and the Interpretation of Dynamic Contact Angles.

    PubMed

    Ramé; Garoff

    1996-01-15

    We have studied shapes of dynamic fluid interfaces at distances contact line at capillary numbers (Ca) ranging from 10(-3) to 10(-1). Near the moving contact line where viscous deformation is important, an analysis valid to O(1) in Ca describes the shape of the fluid interface. Static capillarity should describe the interface shape far from the contact line. We have quantitatively determined the extent of the regions described by the analysis with viscous deformation and by a static shape as a function of Ca. We observe a third portion of the interface between the two regions cited above, which is not described by either the analysis with viscous deformation or a static shape. In this third region the interface shape is controlled by viscous and gravitational forces of comparable magnitude. We detect significant viscous deformation even far from the contact line at Ca approximately > 0.01. Our measured dynamic contact angle parameter extracted by fitting the analysis with viscous deformation to the shape near the moving contact line coincides with the contact angle of the static-like shape far from the contact line. We measure and explain the discrepancy between this dynamic contact angle parameter and the apparent contact angles based on meniscus or apex heights. Our observations of viscous effects at large distances from the contact line have implications for dynamic contact angle measurements in capillary tubes.

  20. Can EGFR-TKIs be used in first line treatment for advanced non-small cell lung cancer based on selection according to clinical factors ? -- A literature-based meta-analysis

    PubMed Central

    2012-01-01

    Background In the first line treatment of non-small cell lung cancer (NSCLC), several clinical trials have shown that not all NSCLC patients can benefit from treatment with tyrosine kinase inhibitors (TKIs) than receiving chemotherapy. Some trials treated patients with TKI according to their clinical characteristics. A few studies only chose patients with an epidermal grouth factor receptor (EGFR) mutation for TKI therapy. We aimed to determine whether patients could be treated with TKIs based on clinical factors in the first-line setting. Methods We performed a meta-analysis of randomized trials involving patients with advanced NSCLC treated with chemotherapy or TKIs by different selections. Efficacy outcomes of interest were the objective response rate (ORR), progression-free survival (PFS) and the overall survival (OS) of each treatment arm. Results Four trials enrolled unselected patients, and two trials selected East Asian patients using the clinical factors of gender and smoking history. Five trials chose patients with an EGFR mutation who were randomized for treatment with TKI or chemotherapy. For unselected patients, the risk ratio (RR) of the ORR was 3.52, the hazard ratio (HR) of the PFS was 1.29 and the HR of the OS was 1.35. For the clinically selected patients, the RR of the ORR was 0.64. The HRs of the PFS and OS were 0.83 and 0.92, respectively. The ORR and PFS were better for TKIs than for chemotherapy in patients with an EGFR mutation. The ORR was 0.47, and the HRs of the PFS and OS were 0.36 and 1.00, respectively. Conclusions Advanced NSCLC patients with an EGFR mutation benefit most from TKIs. EGFR-TKI treatment is justified for patients with unknown EGFR status,and those who cannot tolerate chemotherapy owing to age, poor performance status (PS) or other medical conditions, when selected according to clinical factors in the first-line setting. PMID:23050865

  1. Occupational Contact Dermatitis

    PubMed Central

    2008-01-01

    Occupational contact dermatitis accounts for 90% of all cases of work-related cutaneous disorders. It can be divided into irritant contact dermatitis, which occurs in 80% of cases, and allergic contact dermatitis. In most cases, both types will present as eczematous lesions on exposed parts of the body, notably the hands. Accurate diagnosis relies on meticulous history taking, thorough physical examination, careful reading of Material Safety Data Sheets to distinguish between irritants and allergens, and comprehensive patch testing to confirm or rule out allergic sensitization. This article reviews the pathogenesis and clinical manifestations of occupational contact dermatitis and provides diagnostic guidelines and a rational approach to management of these often frustrating cases. PMID:20525126

  2. SAM Technical Contacts

    EPA Pesticide Factsheets

    These technical contacts are available to help with questions regarding method deviations, modifications, sample problems or interferences, quality control requirements, the use of alternative methods, or the need to address analytes or sample types.

  3. Fragrance allergic contact dermatitis.

    PubMed

    Cheng, Judy; Zug, Kathryn A

    2014-01-01

    Fragrances are a common cause of allergic contact dermatitis in Europe and in North America. They can affect individuals at any age and elicit a spectrum of reactions from contact urticaria to systemic contact dermatitis. Growing recognition of the widespread use of fragrances in modern society has fueled attempts to prevent sensitization through improved allergen identification, labeling, and consumer education. This review provides an overview and update on fragrance allergy. Part 1 discusses the epidemiology and evaluation of suspected fragrance allergy. Part 2 reviews screening methods, emerging fragrance allergens, and management of patients with fragrance contact allergy. This review concludes by examining recent legislation on fragrances and suggesting potential additions to screening series to help prevent and detect fragrance allergy.

  4. Advancement in recombinant protein production using a marine oxygen carrier to enhance oxygen transfer in a CHO-S cell line.

    PubMed

    Le Pape, Fiona; Bossard, Morgane; Dutheil, Delphine; Rousselot, Morgane; Polard, Valérie; Férec, Claude; Leize, Elisabeth; Delépine, Pascal; Zal, Franck

    2015-06-01

    Recombinant proteins, particularly proteins used as therapeutics, are widely expressed for bioprocessing manufacturing processes. Mammalian cell lines represent the major host cells for bioproduction, according to their capacities of post-translational modifications and folding of secreted proteins. Many parameters can affect cell productivity, especially the rate of oxygen transfer. Dissolved oxygen, in high or low proportions, is a crucial parameter which can affect cell viability and thus productivity. HEMARINA has developed a new technology, commercially proposed as HEMOXCell(®), to improve cell culture at a large production scale. HEMOXCell(®) is a marine oxygen carrier having properties of high oxygen sensitivity, to be used as an oxygen additive during cell culture manufacturing. In this study, we investigated the effects of HEMOXCell(®) on the culture of the commonly used CHO-S cell line. Two main objectives were pursued: 1) cell growth rate and viability during a batch mode process, and 2) the determination of the effect of this oxygen carrier on recombinant protein production from a CHO-transfected cell line. Our results show an increase of CHO-S cellular growth at a rate of more than four-fold in culture with HEMOXCell(®). Moreover, an extension of the growth exponential phase and high cell viability were observed. All of these benefits seem to contribute to the improvement of recombinant protein production. This work underlines several applications using this marine-type oxygen carrier for large biomanufacturing. It is a promising cell culture additive according to the increasing demand for therapeutic products such as monoclonal antibodies.

  5. Comparative Proteomic Analysis of Advanced Ovarian Cancer Tissue to Identify Potential Biomarkers of Responders and Nonresponders to First-Line Chemotherapy of Carboplatin and Paclitaxel

    PubMed Central

    Sehrawat, Urmila; Pokhriyal, Ruchika; Gupta, Ashish Kumar; Hariprasad, Roopa; Khan, Mohd Imran; Gupta, Divya; Naru, Jasmine; Singh, Sundararajan Baskar; Mohanty, Ashok Kumar; Vanamail, Perumal; Kumar, Lalit; Kumar, Sunesh; Hariprasad, Gururao

    2016-01-01

    Conventional treatment for advanced ovarian cancer is an initial debulking surgery followed by chemotherapy combination of carboplatin and paclitaxel. Despite initial high response, three-fourths of these women experience disease recurrence with a dismal prognosis. Patients with advanced-stage ovarian cancer who underwent cytoreductive surgery were enrolled and tissue samples were collected. Post surgery, these patients were started on chemotherapy and followed up till the end of the cycle. Fluorescence-based differential in-gel expression coupled with mass spectrometric analysis was used for discovery phase of experiments, and real-time polymerase chain reaction, Western blotting, and pathway analysis were performed for expression and functional validation of differentially expressed proteins. While aldehyde reductase, hnRNP, cyclophilin A, heat shock protein-27, and actin are upregulated in responders, prohibitin, enoyl-coA hydratase, peroxiredoxin, and fibrin-β are upregulated in the nonresponders. The expressions of some of these proteins correlated with increased apoptotic activity in responders and decreased apoptotic activity in nonresponders. Therefore, the proteins qualify as potential biomarkers to predict chemotherapy response. PMID:26997873

  6. Paclitaxel plus valproic acid versus paclitaxel alone as second- or third-line therapy for advanced gastric cancer: a randomized Phase II trial

    PubMed Central

    Fushida, Sachio; Kinoshita, Jun; Kaji, Masahide; Oyama, Katsunobu; Hirono, Yasuo; Tsukada, Tomoya; Fujimura, Takashi; Ohta, Tetsuo

    2016-01-01

    Background Weekly paclitaxel (wPTX) is the preferred second-line chemotherapy for gastric cancer in Japan. Histone deacetylase inhibitors have been shown to decrease proliferation through cell-cycle arrest, differentiation, and apoptosis in gastric cancer cells. One histone deacetylase inhibitor, valproic acid (VPA), also inhibits tumor growth by inducing apoptosis and enhances the efficacy of paclitaxel (PTX), shown in a murine gastric cancer model. This Phase II trial was designed to evaluate the benefits of adding VPA to wPTX in patients with gastric cancer refractory to first-line treatment with fluoropyrimidine. Patients and methods The patients were randomly assigned in a 1:1 ratio to receive PTX 80 mg/m2 intravenously on days 1, 8, and 15, every 4 weeks, or a dose of PTX plus VPA taken everyday at 7.5 mg/kg twice daily. Random assignment was carried out at the data center with a minimization method adjusted by the Eastern Cooperative Oncology Group performance status (0–1 vs 2), prior chemotherapy (first-line vs second-line), and measurable lesions (presence vs absence). The primary end point was the overall survival (OS) rate, and the secondary end points were the progression-free survival rate and safety analysis. Result