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Sample records for surrounding fluid molecules

  1. Black hole solutions surrounded by perfect fluid in Rastall theory

    Science.gov (United States)

    Heydarzade, Y.; Darabi, F.

    2017-08-01

    In this work, we obtain uncharged∖charged Kiselev-like black holes as a new class of black hole solutions surrounded by perfect fluid in the context of Rastall theory. Then, we study the specific cases of the uncharged∖charged black holes surrounded by regular matter like dust and radiation, or exotic matter like quintessence, cosmological constant and phantom fields. By comparing the Kiselev-like black hole solutions in Rastall theory with the Kiselev black hole solutions in GR, we find an effective perfect fluid behavior for the black hole's surrounding field. It is shown that the corresponding effective perfect fluid has interesting characteristic features depending on the different ranges of the parameters in Rastall theory. For instance, Kiselev-like black holes surrounded by regular matter in Rastall theory may be considered as Kiselev black holes surrounded by exotic matter in GR, or Kiselev-like black holes surrounded by exotic matter in Rastall theory may be considered as Kiselev black holes surrounded by regular matter in GR.

  2. Colloids in sepsis: evenly distributed molecules surrounded by uneven questions.

    Science.gov (United States)

    Zampieri, Fernando Godinho; Park, Marcelo; Azevedo, Luciano Cesar Pontes

    2013-05-01

    Colloids are frequently used for fluid expansion in the intensive care unit, although its use on several clinical scenarios remains unproven of any relevant clinical benefit. The purpose of this article was to carry out a narrative review regarding the safety and efficacy of colloids in patients with sepsis and septic shock, with emphasis on the most commonly used colloids, albumin and starches. Colloids are effective fluid expanders and are able to restore the hemodynamic profile with less total volume than crystalloids. These properties appear to be preserved even in patients with sepsis with increased capillary permeability. However, some colloids are associated with renal impairment and coagulation abnormalities. Starch use was associated with increased mortality in two large clinical trials. Also, starches probably have significant renal adverse effects and may be related to more need for renal replacement therapy in severe sepsis. Albumin is the only colloid that has been shown safe in patients with sepsis and that may be associated with improved outcomes on specific subpopulations. No trial so far found any robust clinical end point favoring colloid use in patients with sepsis. Because there is no proven benefit of the use of most colloids in patients with sepsis, its use should not be encouraged outside clinical trials. Albumin is the only colloid solution that has proven to be safe, and its use may be considered on hypoalbuminemic patients with sepsis. Nevertheless, there are no robust data to recommend routine albumin administration in sepsis. Starch use should be avoided in patients with sepsis because of the recent findings of a multicenter randomized study until further evidence is available.

  3. Damping of a fluid-conveying pipe surrounded by a viscous annulus fluid

    Science.gov (United States)

    Kjolsing, Eric J.; Todd, Michael D.

    2017-04-01

    To further the development of a downhole vibration based energy harvester, this study explores how fluid velocity affects damping in a fluid-conveying pipe stemming from a viscous annulus fluid. A linearized equation of motion is formed which employs a hydrodynamic forcing function to model the annulus fluid. The system is solved in the frequency domain through the use of the spectral element method. The three independent variables investigated are the conveyed fluid velocity, the rotational stiffness of the boundary (using elastic springs), and the annulus fluid viscosity. It was found that, due to the hydrodynamic functions frequency-dependence, increasing the conveyed fluid velocity increases the systems damping ratio. It was also noted that stiffer systems saw the damping ratio increase at a slower rate when compared to flexible systems as the conveyed fluid velocity was increased. The results indicate that overestimating the stiffness of a system can lead to underestimated damping ratios and that this error is made worse if the produced fluid velocity or annulus fluid viscosity is underestimated. A numeric example was provided to graphically illustrate these errors. Approved for publication, LA-UR-15-28006.

  4. Drag Coefficient of a Liquid Domain in a Fluid Membrane Surrounded by Confined Three-Dimensional Fluids

    Science.gov (United States)

    Fujitani, Youhei

    2013-08-01

    It is thought that, in a biomembrane, some minor lipid constituents are concentrated in a domain called the lipid raft. Some raftlike domains in a lipid-bilayer membrane can be regarded as two-dimensional droplets. The membrane viscosities inside and outside the domain are generally different. The present author previously studied the drag coefficient of a circular liquid domain in a flat fluid membrane surrounded by three-dimensional fluids, which occupy the semi-infinite spaces on both sides of the membrane. Here we generalize this problem by assuming that the surrounding fluids are confined by container walls parallel to the membrane. Errors in the present author's previous studies are also corrected in this paper.

  5. Global Dynamics of Shaft Lines Rotating in Surrounding Fluids Application to Thin Fluid Films

    Directory of Open Access Journals (Sweden)

    David Lornage

    2004-01-01

    a disc and a thin-walled shaft mounted on a hydrodynamic bearing. The second is intended for studying a more realistic structure composed of a shaft and a wheel coupled with a fluid film between the wheel and a casing. These applications make it possible to identify trends related to fluid effects and couplings between the flexible structural parts.

  6. Resonant frequency of a polyvinylidene flouride piezoelectric bimorph: the effect of surrounding fluid

    Science.gov (United States)

    Abedian, Behrouz; Cundari, Michael

    1993-07-01

    This work presents experimental and theoretical results on the dynamic behavior of piezoelectric cantilever bimorph in the presence of surrounding air. The bimorph is composed of a pair of piezoelectric sheets bonded by a uniform elastic layer of adhesive in the center. The transverse motion of the bimorph is generated by a sequential application of two opposing electric fields on the piezoelectric sheets. Theoretically, the tip deflection and the natural frequency of the bimorph are obtained making use of an energy balance technique. The fluid in modeled as inviscid and incompressible whose motion induces locally additional mass in the transverse direction. An expression for the kinetic energy of the system is derived based on this additional mass from which the natural frequency of the combined system is obtained. Tests were performed on the piezoelectric bimorphs with similar geometries and varying adhesive thickness in a vacuum chamber. The air pressure in the chamber was varied from 10 kPa to one atmosphere. Good agreements between the theoretical predictions and the observed values were obtained. This study could have applications in the use of piezoelectric materials for fluid property measurements.

  7. Structure and freezing of a fluid of long elongated molecules

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Pankaj; Ram, Jokhan; Singh, Yashwant [Department of Physics, Banaras Hindu University, Varanasi-221 005 (India)

    2004-03-17

    The pair correlation functions of a fluid of long elongated molecules interacting via the Gay-Berne pair potential are calculated using the Percus-Yevick integral equation theory. Numerical accuracy has been examined by considering a large number of spherical harmonic coefficients for each orientation-dependent functions for a system of molecules having a length-to-breadth ratio equal to 4.4 at different densities and temperatures. The pair correlation functions of the isotropic fluid found from the Percus-Yevick theory have been used in the density-functional theory to locate the isotropic-nematic, isotropic-smectic A and nematic-smectic A transitions. It is found that at low temperatures the fluid freezes directly into the smectic A phase on increasing the density. The nematic phase is found to stabilize in between the isotropic and smectic A phases only at high temperatures and high densities. The calculated phase diagram is in good qualitative agreement with computer simulation results.

  8. Instability of a conducting viscous fluid layer surrounding a solid rod

    Energy Technology Data Exchange (ETDEWEB)

    Prudnikov, V.V.

    1979-04-25

    Stabilization of MHD instabilities serves to introduce into a conductor sufficient energy to achieve a rapid and uniform vaporization of the conductor surface. In this connection, axisymmetric perturbations of a layer of viscous fluid with current flowing along its surface are analyzed in linear terms. The small-perturbation method is used to formulate the corresponding dispersion formula, from which estimates of the increment of instability in the presence of low and high wave numbers are derived. These estimates point to the existence of a certain wave number at which that increment is minimal. In both cases (low and high wave numbers) the increment is directly proportional to the square of current intensity, inversely proportional to viscosity, and independent of density. At high wave numbers this increment is also independent of the layer thickness (coincides with the Taylor estimate for a compressible viscous fluid column with surface current). 6 references.

  9. Global Existence and Asymptotic Behavior of Affine Motion of 3D Ideal Fluids Surrounded by Vacuum

    Science.gov (United States)

    Sideris, Thomas C.

    2017-07-01

    The 3D compressible and incompressible Euler equations with a physical vacuum free boundary condition and affine initial conditions reduce to a globally solvable Hamiltonian system of ordinary differential equations for the deformation gradient in {GL^+(3, R)}. The evolution of the fluid domain is described by a family of ellipsoids whose diameter grows at a rate proportional to time. Upon rescaling to a fixed diameter, the asymptotic limit of the fluid ellipsoid is determined by a positive semi-definite quadratic form of rank r = 1, 2, or 3, corresponding to the asymptotic degeneration of the ellipsoid along 3- r of its principal axes. In the compressible case, the asymptotic limit has rank r = 3, and asymptotic completeness holds, when the adiabatic index {γ} satisfies {4/3 adiabatic index {γ}. In the incompressible case, affine motion reduces to geodesic flow in {SL(3, R)} with the Euclidean metric. For incompressible affine swirling flow, there is a structural instability. Generically, when the vorticity is nonzero, the domains degenerate along only one axis, but the physical vacuum boundary condition fails over a finite time interval. The rescaled fluid domains of irrotational motion can collapse along two axes.

  10. Distributions of molecules in the circumnuclear disk and surrounding starburst ring in the Seyfert galaxy NGC 1068 observed with ALMA

    CERN Document Server

    Takano, Shuro; Kohno, Kotaro; Harada, Nanase; Herbst, Eric; Tamura, Yoichi; Izumi, Takuma; Taniguchi, Akio; Tosaki, Tomoka

    2014-01-01

    Sensitive observations with ALMA allow astronomers to observe the detailed distributions of molecules with relatively weak intensity in nearby galaxies. In particular, we report distributions of several molecular transitions including shock and dust related species ($^{13}$CO $J$ = 1--0, C$^{18}$O $J$ = 1--0, $^{13}$CN $N$ = 1--0, CS $J$ = 2--1, SO $J_N$ = 3$_2$--2$_1$, HNCO $J_{Ka,Kc}$ = 5$_{0,5}$--4$_{0,4}$, HC$_3$N $J$ = 11--10, 12--11, CH$_3$OH $J_K$ = 2$_K$--1$_K$, and CH$_3$CN $J_K$ = 6$_K$--5$_K$) in the nearby Seyfert 2 galaxy NGC 1068 observed with the ALMA early science program. The central $\\sim$1 arcmin ($\\sim$4.3 kpc) of this galaxy was observed in the 100 GHz region covering $\\sim$96--100 GHz and $\\sim$108--111 GHz with an angular resolution of $\\sim4"\\times2"$ (290 pc$\\times$140 pc) to study the effects of an active galactic nucleus and its surrounding starburst ring on molecular abundances. Here, we present images and report a classification of molecular distributions into three main categorie...

  11. Global dynamics of shaft lines of turbo-machineries coupled to surrounding fluids: application to the case of fluid sheets; Dynamique globale des lignes d'arbres de turbomachines couplees aux fluides environnants: application au cas des lames fluides

    Energy Technology Data Exchange (ETDEWEB)

    Lornage, D.

    2001-12-15

    Shaft lines of turbo-machineries have to stand increasing reliability, efficiency and safety requirements. A precise modeling of the rotating parts with all possible coupling has become necessary. In this context, this work aims to develop a global modeling of rotating wheel/shaft system inside a surrounding fluid in order to foresee its dynamical behaviour. The use and advantage of Eulerian, Lagrangian and mixed (arbitrary Lagrangian Eulerian - ALE) formulations is recalled first. A bibliographic synthesis of the classical techniques used in structure mechanics and of coupling techniques for rotating machines is presented. The coupling technique retained is presented. It uses fluid and structure models independently developed and validated. The structure domain is discretized by the finite-element method. The fluid domain is discretized by the finite-difference method taking into consideration the hypotheses linked with thin films. A modal base projection combined with a mesh at the fluid-structure interface allows an efficient, adaptable and evolutive coupling. Finally, the method is applied to 3 test-cases. The first two ones comprise a shaft/disc system coupled to a fluid sheet between the disc and the casing and to an hydrodynamic bearing. Both cases allow a first validation of the coupling method. The third case aims to study a structure closer to a real system made of a shaft and a wheel coupled to a fluid sheet between a flange and a casing. These three applications allow to show the trends linked with the fluid effects and the coupling between the flexible sub-parts of the structure. (J.S.)

  12. A density functional theory for association of fluid molecules with a functionalized surface: fluid-wall single and double bonding

    Science.gov (United States)

    Haghmoradi, Amin; Wang, Le; Chapman, Walter G.

    2017-02-01

    In this manuscript we extend Wertheim’s two-density formalism beyond its first order to model a system of fluid molecules with a single association site close to a planar hard wall with association sites on its surface in a density functional theory framework. The association sites of the fluid molecules are small enough that they can form only one bond, while the wall association sites are large enough to bond with more than one fluid molecule. The effects of temperature and of bulk fluid and wall site densities on the fluid density profile, extent of association, and competition between single and double bonding of fluid segments at the wall sites versus distance from the wall are presented. The theory predictions are compared with new Monte Carlo simulation results and they are in good agreement. The theory captures the surface coverage over wide ranges of temperature and bulk density by introducing the effect of steric hindrance in fluid association at a wall site.

  13. Application of inhomogeneous fluid solvation theory to model the distribution and thermodynamics of water molecules around biomolecules.

    Science.gov (United States)

    Huggins, David J

    2012-11-21

    The structures of biomolecules and the strengths of association between them depend critically on interactions with water molecules. Thus, understanding these interactions is a prerequisite for understanding the structure and function of all biomolecules. Inhomogeneous fluid solvation theory provides a framework to derive thermodynamic properties of individual water molecules from a statistical mechanical analysis. In this work, two biomolecules are analysed to probe the distribution and thermodynamics of surrounding water molecules. The great majority of hydration sites are predicted to contribute favourably to the total free energy with respect to bulk water, though hydration sites close to non-polar regions of the solute do not contribute significantly. Analysis of a biomolecule with a positively and negatively charged functional group predicts that a charged species perturbs the free energy of water molecules to a distance of approximately 6.0 Å. Interestingly, short simulations are found to provide converged predictions if samples are taken with sufficient frequency, a finding that has the potential to significantly reduce the required computational cost of such analysis. In addition, the predicted thermodynamic properties of hydration sites with the potential for direct hydrogen bonding interactions are found to disagree significantly for two different water models. This study provides important information on how inhomogeneous fluid solvation theory can be employed to understand the structures and intermolecular interactions of biomolecules.

  14. POLYMER MEAN SPHERICAL APPROXIMATION FOR THE FLUID OF FLEXIBLE HARD-SPHERE YUKAWA STAR MOLECULES

    Directory of Open Access Journals (Sweden)

    Yu.V.Kalyuzhnyi

    2002-01-01

    Full Text Available An extension of the product-reactant Ornstein-Zernike approach (PROZA for the fluid of flexible star molecules is proposed and the corresponding version of the mean spherical approximation (MSA, the so-called polymer MSA (PMSA, is formulated. Using Baxter-Wertheim factorization technique, an analytical solution of the PMSA for the fluid of star molecules with Yukawa hard-sphere interaction between the molecular segments is derived and closed form analytical expressions for the Helmholtz free energy, chemical potential and equation of state are presented. The structure properties of several different versions of the star fluid model are studied.

  15. Theoretical Treatment of the Thermophysical Properties of Fluids Containing Chain-like Molecules

    Energy Technology Data Exchange (ETDEWEB)

    Carol K. Hall

    2008-11-14

    This research program was designed to enhance our understanding of the behavior of fluids and fluid mixtures containing chain-like molecules. The original objective was to explain and predict the experimentally observed thermophysical properties, including phase equilibria and dynamics, of systems containing long flexible molecules ranging in length from alkanes to polymers. Over the years the objectives were expanded to include the treatment of molecules that were not chain-like. Molecular dynamics and Monte Carlo computer simulations were used to investigate how variations in molecular size, shape and architecture influence the types of phase equilibria, thermodynamic properties, structure and surface interactions that are observed experimentally. The molecular insights and theories resulting from this program could eventually serve as the foundation upon which to build correlations of the properties of fluids that are both directly and indirectly related to the Nation’s energy resources including: petroleum, natural gas, and polymer solutions, melts, blends, and materials.

  16. Nonequilibrium temperature and bulk viscosity for a dense fluid of square-well molecules

    NARCIS (Netherlands)

    Beijeren, H. van; Karkheck, J.; Sengers, J.V.

    1988-01-01

    A recently proposed nonlinear kinetic theory for a dense fluid of square-well molecules reveals the existence of two temperature scales, one associated with kinetic energy and the other with potential energy. The scales are coupled through conservation of energy and, for nonequilibrium states, the

  17. TOWARDS A SIMPLIFIED APPROACH TO THE MODELLING OF THE STAR-LIKE MOLECULE FLUIDS

    Directory of Open Access Journals (Sweden)

    Yu.Duda

    2002-01-01

    Full Text Available A theoretical approach to considering a wide spectrum of equilibrium properties of fluids formed from the four-branched molecules (e.g. four-arm star polysterene samples, four-arm block copolymers, etc. is presented and discussed. The proposed approach is within the framework of an associative version of integral equation theory and is based on an analytical solution of the four-site associative hard-sphere model. Results and discussion are explained by the comparison against Monte Carlo computer simulation data generated for a freely-joined tangent hard-sphere model of a star-like molecule fluid. It is shown that the proposed theory works well for the star-like molecule fluids in homogeneous phase where it predicts the structure for molecules with relatively long arms and at high densities. The obtained results qualitatively reproduce the most important experimental features of the solvation force induced between two macrosurfaces due to the presence of star-like aggregates.

  18. Formation of clusters composed of C60 molecules via self-assembly in critical fluids

    Science.gov (United States)

    Fukuda, Takahiro; Ishii, Koji; Kurosu, Shunji; Whitby, Raymond; Maekawa, Toru

    2007-04-01

    Fullerenes are promising candidates for intelligent, functional nanomaterials because of their unique mechanical, electronic and chemical properties. However, it is necessary to invent some efficient but relatively simple methods of producing structures composed of fullerenes for the development of nanomechatronic, nanoelectronic and biochemical devices and sensors. In this paper, we show that various structures such as straight fibres, networks formed by fibres, wide sheets and helical structures, which are composed of C60 molecules, are created by placing C60-crystals in critical ethane, carbon dioxide and xenon even though C60 molecules do not dissolve or disperse in the above fluids. It is supposed, judging by the intermolecular potentials between C60 and C60, between C60 and ethane, and between ethane and ethane, that C60-clusters grow with the assistance of solvent molecules, which are trapped between C60 molecules under critical conditions. This room-temperature self-assembly cluster growth process in critical fluids may open up a new methodology of forming structures built up with fullerenes without the need for any ultra-fine processing technologies.

  19. Accurate statistical associating fluid theory for chain molecules formed from Mie segments.

    Science.gov (United States)

    Lafitte, Thomas; Apostolakou, Anastasia; Avendaño, Carlos; Galindo, Amparo; Adjiman, Claire S; Müller, Erich A; Jackson, George

    2013-10-21

    A highly accurate equation of state (EOS) for chain molecules formed from spherical segments interacting through Mie potentials (i.e., a generalized Lennard-Jones form with variable repulsive and attractive exponents) is presented. The quality of the theoretical description of the vapour-liquid equilibria (coexistence densities and vapour pressures) and the second-derivative thermophysical properties (heat capacities, isobaric thermal expansivities, and speed of sound) are critically assessed by comparison with molecular simulation and with experimental data of representative real substances. Our new EOS represents a notable improvement with respect to previous versions of the statistical associating fluid theory for variable range interactions (SAFT-VR) of the generic Mie form. The approach makes rigorous use of the Barker and Henderson high-temperature perturbation expansion up to third order in the free energy of the monomer Mie system. The radial distribution function of the reference monomer fluid, which is a prerequisite for the representation of the properties of the fluid of Mie chains within a Wertheim first-order thermodynamic perturbation theory (TPT1), is calculated from a second-order expansion. The resulting SAFT-VR Mie EOS can now be applied to molecular fluids characterized by a broad range of interactions spanning from soft to very repulsive and short-ranged Mie potentials. A good representation of the corresponding molecular-simulation data is achieved for model monomer and chain fluids. When applied to the particular case of the ubiquitous Lennard-Jones potential, our rigorous description of the thermodynamic properties is of equivalent quality to that obtained with the empirical EOSs for LJ monomer (EOS of Johnson et al.) and LJ chain (soft-SAFT) fluids. A key feature of our reformulated SAFT-VR approach is the greatly enhanced accuracy in the near-critical region for chain molecules. This attribute, combined with the accurate modeling of second

  20. Interfacial instabilities affect microfluidic extraction of small molecules from non-Newtonian fluids.

    Science.gov (United States)

    Helton, Kristen L; Yager, Paul

    2007-11-01

    As part of a project to develop an integrated microfluidic biosensor for the detection of small molecules in saliva, practical issues of extraction of analytes from non-Newtonian samples using an H-filter were explored. The H-filter can be used to rapidly and efficiently extract small molecules from a complex sample into a simpler buffer. The location of the interface between the sample and buffer streams is a critical parameter in the function of the H-filter, so fluorescence microscopy was employed to monitor the interface position; this revealed apparently anomalous fluorophore diffusion from the samples into the buffer solutions. Using confocal microscopy to understand the three-dimensional distribution of the fluorophore, it was found that the interface between the non-Newtonian sample and Newtonian buffer was both curved and unstable. The core of the non-Newtonian sample extended into the Newtonian buffer and its position was unstable, producing a fluorescence intensity profile that gave rise to the apparently anomalously fast fluorophore transport. These instabilities resulted from the pairing of rheologically dissimilar fluid streams and were flowrate dependent. We conclude that use of non-Newtonian fluids, such as saliva, in the H-filter necessitates pretreatment to reduce viscoelasticity. The interfacial variation in position, stability and shape caused by the non-Newtonian samples has substantial implications for the use of biological samples for quantitative analysis and analyte extraction in concurrent flow extraction devices.

  1. Time-dependent quantum fluid density functional theory of hydrogen molecule under intense laser fields

    Indian Academy of Sciences (India)

    Amita Wadehra; B M Deb

    2007-09-01

    A time-dependent generalized non-linear Schrödinger equation (GNLSE) of motion was earlier derived in our laboratory by combining density functional theory and quantum fluid dynamics in threedimensional space. In continuation of the work reported previously, the GNLSE is applied to provide additional knowledge on the femtosecond dynamics of the electron density in the hydrogen molecule interacting with high-intensity laser fields. For this purpose, the GNLSE is solved numerically for many time-steps over a total interaction time of 100 fs, by employing a finite-difference scheme. Various time-dependent (TD) quantities, namely, electron density, ground-state survival probability and dipole moment have been obtained for two laser wavelengths and four different intensities. The high-order harmonics generation (HHG) is also examined. The present approach goes beyond the linear response formalism and, in principle, calculates the TD electron density to all orders of change.

  2. Atomic Hydrogen Surrounded by Water Molecules, H(H2O)m, Modulates Basal and UV-Induced Gene Expressions in Human Skin In Vivo

    Science.gov (United States)

    Shin, Mi Hee; Park, Raeeun; Nojima, Hideo; Kim, Hyung-Chel; Kim, Yeon Kyung; Chung, Jin Ho

    2013-01-01

    Recently, there has been much effort to find effective ingredients which can prevent or retard cutaneous skin aging after topical or systemic use. Here, we investigated the effects of the atomic hydrogen surrounded by water molecules, H(H2O)m, on acute UV-induced responses and as well as skin aging. Interestingly, we observed that H(H2O)m application to human skin prevented UV-induced erythema and DNA damage. And H(H2O)m significantly prevented UV-induced MMP-1, COX-2, IL-6 and IL-1β mRNA expressions in human skin in vivo. We found that H(H2O)m prevented UV-induced ROS generation and inhibited UV-induced MMP-1, COX-2 and IL-6 expressions, and UV-induced JNK and c-Jun phosphorylation in HaCaT cells. Next, we investigated the effects of H(H2O)m on intrinsically aged or photoaged skin of elderly subjects. In intrinsically aged skin, H(H2O)m application significantly reduced constitutive expressions of MMP-1, IL-6, and IL-1β mRNA. Additionally, H(H2O)m significantly increased procollagen mRNA and also decreased MMP-1 and IL-6 mRNA expressions in photoaged facial skin. These results demonstrated that local application of H(H2O)m may prevent UV-induced skin inflammation and can modulate intrinsic skin aging and photoaging processes. Therefore, we suggest that modifying the atmospheric gas environment within a room may be a new way to regulate skin functions or skin aging. PMID:23637886

  3. Cerebrospinal fluid and plasma concentration of soluble intercellular adhesion molecule1, vascular cell adhesion molecule1 and endothelial leukocyte adhesion molecule in patients with acute ischemic b

    Directory of Open Access Journals (Sweden)

    Selaković Vesna M.

    2003-01-01

    Full Text Available Background. Leukocyte migration into the ischemic area is a complex process controlled by adhesion molecules (AM in leukocytes and endothelium, by migratory capacity of leukocytes and the presence of hemotaxic agents in the tissue. In this research it was supposed that in the blood and cerebrospinal fluid (CSF of patients in the acute phase of ischemic brain disease (IBD there were relevant changes in the concentration of soluble AM (sICAM-1 sVCAM-1 and sE-selectin, that could have been the indicators of the intensity of damaging processes in central nervous system (CNS. Methods. The study included 45 IBD patients, 15 with transient ischemic attack (TIA 15 with reversible ischemic attack (RIA, and 15 with brain infarction (BI of both sexes, mean age 66±7. Control group consisted of 15 patients with radicular lesions of discal origin, subjected to diagnostic radiculography without the signs of interruption in the passage of CSF. Changes of selected biochemical parameters were determined in all patients in frame 72 hours since the occurence of an ischemic episode. Concentrations of soluble AM were determined in plasma and CSF by ELISA. Total number of leukocytes (TNL in peripheral blood was determined by hematological analyzer. Results. The results showed that during the first 72 hrs of IBD significant increases occured in TNL and that the increase was progressive compared to the severeness of the disease. Significant increase of soluble AM concentration was shown in plasma of IBD patients. The increase was highest in BI somewhat lower in RIA and the lowest in TIA patients compared to the control. In CSF concentrations of sICAM-1, sVCAM-1 and sE-selectin demonstrated similar increasing trend as in plasma. Conclusion. TNL, as well as the soluble AM concentrations in plasma and CSF, were increased during the acute IBD phase and progressive in relation to the severeness of the disease, so that they might have been the indicators of CNS inflammatory

  4. Intraocular soluble intracellular adhesion molecule-1 correlates with subretinal fluid height of diabetic macular edema

    Directory of Open Access Journals (Sweden)

    Dan Zhu

    2014-01-01

    Full Text Available Objective: To investigate the correlations between aqueous concentrations of vascular endothelial growth factor (VEGF, monocyte chemoattractant protein-1 (MCP-1, soluble intracellular adhesion molecule-1 (sICAM-1 and diabetic macular edema (DME. Materials and Methods: VEGF, MCP-1 and sICAM-1 concentrations in aqueous humor samples of 22 patients with DME and 23 patients with cataract of a control group were measured with solid-phase chemiluminescence immunoassay. Results: Aqueous VEGF (89.2 ± 58.5 pg/ml versus 48.5 ± 27.8 pg/ml, P = 0.006, MCP-1 (684.2 ± 423.4 pg/ml versus 432.4 ± 230.4 pg/ml, P = 0.019 and sICAM-1 (3213.8 ± 2581.6 pg/ml versus 260.2 ± 212.2 pg/ml, P < 0.001 all vary significantly between DME group and control group. Maximum height of submacular fluid measured by Optical coherence tomography (OCT was significantly associated with aqueous sICAM-1 (r = -0.45, P = 0.034. The maximum height of macular thickness measured by OCT was not significantly associated with either VEGF (P = 0.300, MCP-1 (P = 0.320 or sICAM-1 (P = 0.285. Conclusions: Our results suggest that sICAM-1 may majorly contribute to the formation of subretinal fluid in DME patients and imply that MCP-1 and sICAM-1 may be the potential therapy targets, besides VEGF.

  5. Neural cell adhesion molecule (NCAM) and prealbumin in cerebrospinal fluid from depressed patients

    DEFF Research Database (Denmark)

    Jørgensen, Ole Steen

    1988-01-01

    fluid, both compared to cisternal fluid. Whereas prealbumin was found evenly distributed in CSF, albumin was relatively enriched in lumbar fluid. The concentrations of NCAM-sol and prealbumin were measured in lumbar CSF from psychiatric patients. Prealbumin was increased 7.2% and NCAM-sol was decreased...

  6. Maternal-fetal fluid balance and aquaporins: from molecule to physiology

    Institute of Scientific and Technical Information of China (English)

    Xiao-yan SHA; Zheng-fang XIONG; Hui-shu LIU; Xiao-dan DI; Tong-hui MA

    2011-01-01

    Maternal-fetal fluid balance is critical during pregnancy, and amniotic fluid is essential for fetal growth and development. The placenta plays a key role in a successful pregnancy as the interface between the mother and her fetus. Aquaporins (AQPs) form specific water channels that allow the rapid transcellular movement of water in response to osmotic/hydrostatic pressure gradients. AQPs expression in the placenta and fetal membranes may play important roles in the maternal-fetal fluid balance.

  7. Formation of clusters composed of C{sub 60} molecules via self-assembly in critical fluids

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Takahiro [Bio-Nano Electronics Research Centre, Toyo University, 2100, Kujirai, Kawagoe, Saitama 350-8585 (Japan); Ishii, Koji [Bio-Nano Electronics Research Centre, Toyo University, 2100, Kujirai, Kawagoe, Saitama 350-8585 (Japan); Kurosu, Shunji [Bio-Nano Electronics Research Centre, Toyo University, 2100, Kujirai, Kawagoe, Saitama 350-8585 (Japan); Whitby, Raymond [School of Pharmacy and Biomolecular Sciences, University of Brighton, Cockroft Building, Lewes Road, Brighton BN2 4GJ (United Kingdom); Maekawa, Toru [Bio-Nano Electronics Research Centre, Toyo University, 2100, Kujirai, Kawagoe, Saitama 350-8585 (Japan)

    2007-04-11

    Fullerenes are promising candidates for intelligent, functional nanomaterials because of their unique mechanical, electronic and chemical properties. However, it is necessary to invent some efficient but relatively simple methods of producing structures composed of fullerenes for the development of nanomechatronic, nanoelectronic and biochemical devices and sensors. In this paper, we show that various structures such as straight fibres, networks formed by fibres, wide sheets and helical structures, which are composed of C{sub 60} molecules, are created by placing C{sub 60}-crystals in critical ethane, carbon dioxide and xenon even though C{sub 60} molecules do not dissolve or disperse in the above fluids. It is supposed, judging by the intermolecular potentials between C{sub 60} and C{sub 60}, between C{sub 60} and ethane, and between ethane and ethane, that C{sub 60}-clusters grow with the assistance of solvent molecules, which are trapped between C{sub 60} molecules under critical conditions. This room-temperature self-assembly cluster growth process in critical fluids may open up a new methodology of forming structures built up with fullerenes without the need for any ultra-fine processing technologies.

  8. Molecular Nanoshearing: An Innovative Approach to Shear off Molecules with AC-Induced Nanoscopic Fluid Flow

    Science.gov (United States)

    Shiddiky, Muhammad J. A.; Vaidyanathan, Ramanathan; Rauf, Sakandar; Tay, Zhikai; Trau, Matt

    2014-01-01

    Early diagnosis of disease requires highly specific measurement of molecular biomarkers from femto to pico-molar concentrations in complex biological (e.g., serum, blood, etc.) samples to provide clinically useful information. While reaching this detection limit is challenging in itself, these samples contain numerous other non-target molecules, most of which have a tendency to adhere to solid surfaces via nonspecific interactions. Herein, we present an entirely new methodology to physically displace nonspecifically bound molecules from solid surfaces by utilizing a newly discovered ``tuneable force'', induced by an applied alternating electric field, which occurs within few nanometers of an electrode surface. This methodology thus offers a unique ability to shear-off loosely bound molecules from the solid/liquid interface. Via this approach, we achieved a 5-fold reduction in nonspecific adsorption of non-target protein molecules and a 1000-fold enhancement for the specific capture of HER2 protein in human serum.

  9. Dynamic Influences of Non-Stationary Liquid Flows in Fluid Drives of Heavy Metallurgical Machines on System Dynamics and Reaction for Surroundings

    Directory of Open Access Journals (Sweden)

    Michalczyk J.

    2015-04-01

    Full Text Available The influence of liquids contained in hydraulic pipes of drives of heavy metallurgical machines, e.g. forging hammers and presses, on reduced mass and system dynamics and forces and moments of reaction for surroundings, was investigated in the paper.

  10. High-Resolution Single-Molecule Fluorescence Imaging of Zeolite Aggregates within Real-Life Fluid Catalytic Cracking Particles**

    Science.gov (United States)

    Ristanović, Zoran; Kerssens, Marleen M; Kubarev, Alexey V; Hendriks, Frank C; Dedecker, Peter; Hofkens, Johan; Roeffaers, Maarten B J; Weckhuysen, Bert M

    2015-01-01

    Fluid catalytic cracking (FCC) is a major process in oil refineries to produce gasoline and base chemicals from crude oil fractions. The spatial distribution and acidity of zeolite aggregates embedded within the 50–150 μm-sized FCC spheres heavily influence their catalytic performance. Single-molecule fluorescence-based imaging methods, namely nanometer accuracy by stochastic chemical reactions (NASCA) and super-resolution optical fluctuation imaging (SOFI) were used to study the catalytic activity of sub-micrometer zeolite ZSM-5 domains within real-life FCC catalyst particles. The formation of fluorescent product molecules taking place at Brønsted acid sites was monitored with single turnover sensitivity and high spatiotemporal resolution, providing detailed insight in dispersion and catalytic activity of zeolite ZSM-5 aggregates. The results point towards substantial differences in turnover frequencies between the zeolite aggregates, revealing significant intraparticle heterogeneities in Brønsted reactivity. PMID:25504139

  11. Group contribution methodology based on the statistical associating fluid theory for heteronuclear molecules formed from Mie segments.

    Science.gov (United States)

    Papaioannou, Vasileios; Lafitte, Thomas; Avendaño, Carlos; Adjiman, Claire S; Jackson, George; Müller, Erich A; Galindo, Amparo

    2014-02-07

    A generalization of the recent version of the statistical associating fluid theory for variable range Mie potentials [Lafitte et al., J. Chem. Phys. 139, 154504 (2013)] is formulated within the framework of a group contribution approach (SAFT-γ Mie). Molecules are represented as comprising distinct functional (chemical) groups based on a fused heteronuclear molecular model, where the interactions between segments are described with the Mie (generalized Lennard-Jonesium) potential of variable attractive and repulsive range. A key feature of the new theory is the accurate description of the monomeric group-group interactions by application of a high-temperature perturbation expansion up to third order. The capabilities of the SAFT-γ Mie approach are exemplified by studying the thermodynamic properties of two chemical families, the n-alkanes and the n-alkyl esters, by developing parameters for the methyl, methylene, and carboxylate functional groups (CH3, CH2, and COO). The approach is shown to describe accurately the fluid-phase behavior of the compounds considered with absolute average deviations of 1.20% and 0.42% for the vapor pressure and saturated liquid density, respectively, which represents a clear improvement over other existing SAFT-based group contribution approaches. The use of Mie potentials to describe the group-group interaction is shown to allow accurate simultaneous descriptions of the fluid-phase behavior and second-order thermodynamic derivative properties of the pure fluids based on a single set of group parameters. Furthermore, the application of the perturbation expansion to third order for the description of the reference monomeric fluid improves the predictions of the theory for the fluid-phase behavior of pure components in the near-critical region. The predictive capabilities of the approach stem from its formulation within a group-contribution formalism: predictions of the fluid-phase behavior and thermodynamic derivative properties of

  12. CID: Chemistry in disks VI.sulfur-bearing molecules in the protoplanetary disks surrounding LkCa15, MWC480, DM Tau, and GO Tau

    CERN Document Server

    Dutrey, Anne; Boehler, Yann; Guilloteau, Stéphane; Hersant, Franck; Semenov, Dmitry; Chapillon, Edwige; Henning, Thomas; Piétu, Vincent; Launhardt, Ralf; Gueth, Frederic; Schreyer, Katharina

    2011-01-01

    We study the content in S-bearing molecules of protoplanetary disks around low-mass stars. We used the new IRAM 30-m receiver EMIR to perform simultaneous observations of the $1_{10}-1_{01}$ line of H$_2$S at 168.8 GHz and $2_{23}-1_{12}$ line of SO at 99.3 GHz. We compared the observational results with predictions coming from the astrochemical code NAUTILUS, which has been adapted to protoplanetary disks. The data were analyzed together with existing CS J=3-2 observations. We fail to detect the SO and H$_2$S lines, although CS is detected in LkCa15, DM\\,Tau, and GO\\,Tau but not in MWC\\,480. However, our new upper limits are significantly better than previous ones and allow us to put some interesting constraints on the sulfur chemistry. Our best modeling of disks is obtained for a C/O ratio of 1.2, starting from initial cloud conditions of H density of $2\\times 10^5$ cm$^{-3}$ and age of $10^6$ yr. The results agree with the CS data and are compatible with the SO upper limits, but fail to reproduce the H$_2$...

  13. Effects on the structure of monolayer and submonolayer fluid nitrogen films by the corrugation in the holding potential of nitrogen molecules

    DEFF Research Database (Denmark)

    Hansen, Flemming Yssing

    2001-01-01

    of interactions were indicated by the comparison of the calculated and measured isosteric heats of adsorption in fluid films of nitrogen molecules on graphite. The melting temperatures were lowered by 7K and a region of liquid-gas coexistence was observed for films on the smooth graphite surface indicating......The effects of corrugation in the holding potential of nitrogen molecules on the structure of fluid monolayer and submonolayer films of the molecules on a solid substrate was studied using molecular dynamics simulation. Including McLachlan mediation of the intermolecular potential in a model...

  14. Quantum Fluids of Self-Assembled Chains of Polar Molecules at Finite Temperature

    Institute of Scientific and Technical Information of China (English)

    ZHU Kun-Yan; TAN Lei; GAO Xiang; WANG Daw-Wei

    2008-01-01

    The finite temperature properties of self-assembled dipole chains of polar molecules in strongly confined pancake traps are investigated.The single-chain vibrations at finite temperature,which become important for long chains in a strongly interacting regime,are found to lower the transition temperature and to shift the chain distribution by less than 10%.We also propose experimental parameters to observe such quantum phase transition.

  15. Transient, three-dimensional potential flow problems and dynamic response of the surrounding structures. I - Description of the fluid dynamics by a singularity method /Computer code SING/

    Science.gov (United States)

    Krieg, R.; Hailfinger, G.

    1980-02-01

    In Part I a singularity method - also called boundary integral equation method or panel method - has been developed that is applicable especially to highly transient internal flow problems with any three-dimensional geometry including walls wetted on both sides. The boundary conditions are prescribed in terms of pressures and/or accelerations. The method is primarily based on a recently developed dipole element treatment for incompressible fluids. Such elements (panels) can be fitted to the fluid boundary or any enveloping surface. Also, point sources may be included. The applicability of the method is demonstrated by two different examples: the incipient flow in a T-joint and the oscillating flow in the pressure suppression system of a boiling water reactor.

  16. Embryonic cerebrospinal fluid nanovesicles carry evolutionarily conserved molecules and promote neural stem cell amplification.

    Directory of Open Access Journals (Sweden)

    David M Feliciano

    Full Text Available During brain development, neural stem cells (NSCs receive on-or-off signals important for regulating their amplification and reaching adequate neuron density. However, how a coordinated regulation of intracellular pathways and genetic programs is achieved has remained elusive. Here, we found that the embryonic (e CSF contains 10¹² nanoparticles/ml (77 nm diameter, some of which were identified as exosome nanovesicles that contain evolutionarily conserved molecules important for coordinating intracellular pathways. eCSF nanovesicles collected from rodent and human embryos encapsulate protein and microRNA components of the insulin-like growth factor (IGF signaling pathway. Supplementation of eCSF nanovesicles to a mixed culture containing eNSCs activated the IGF-mammalian target of rapamycin complex 1 (mTORC1 pathway in eNSCs and expanded the pool of proliferative eNSCs. These data show that the eCSF serves as a medium for the distribution of nanovesicles, including exosomes, and the coordinated transfer of evolutionary conserved molecules that regulate eNSC amplification during corticogenesis.

  17. Amniotic fluid may act as a transporting pathway for signaling molecules and stem cells during the embryonic development of amniotes.

    Science.gov (United States)

    Tong, Xinglong

    2013-11-01

    Amniotic fluid (AF) is formed at the very early stages of pregnancy, and is present throughout embryonic development of amniotes. It is well-known that AF provides a protective sac around the fetus that allows fetal movement and growth, and prevents mechanical and thermal shock. However, a growing body of evidence has shown that AF contains a number of proteins and peptides, including growth factors and cytokines, which potently affect cellular growth and proliferation. In addition, pluripotent stem cells have recently been identified in AF. Herein, this article reviews the biological properties of AF during embryonic development and speculates that AF may act as a transporting pathway for signaling molecules and stem cells during amniote embryonic development. Defining this novel function of AF is potentially significant for further understanding embryonic development and regenerative medicine, preventing genetic diseases, and developing therapeutic options for human malignancies.

  18. Effect of selective laser melting deposition cobalt chromium alloy porcelain crown restoration on related molecule contents in serum and gingival crevicular fluid

    Institute of Scientific and Technical Information of China (English)

    Yu-Hua Wei; Lei Yang

    2015-01-01

    Objective:To study the effect of selective laser melting deposition cobalt chromium alloy porcelain crown restoration on contents of inflammatory cytokines and adhesion molecules in serum and gingival tissue.Methods:80 cases of patients who received cobalt chromium alloy porcelain crown restoration in our hospital from May 2013 to August 2014 were enrolled and randomly divided into two groups. Observation group received selective laser melting deposition cobalt chromium alloy porcelain crown restoration and control group received casting cobalt chromium metal porcelain crown restoration. Then contents of inflammatory cytokines and adhesion molecules in serum and gingival crevicular fluid of both groups were detected.Results: (1) Inflammatory cytokines: compared with serum inflammatory cytokine contents of control group, serum NF-κB, IL-6, IL-8, IL-1β, TNF-α and NO contents of observation group trended to decrease; (2) Adhesion molecules in gingival crevicular fluid: compared with adhesion molecule contents in gingival crevicular fluid of control group, mRNA contents of CD11a, CD18, LFA-1, E-selectin and P-selectin in gingival crevicular fluid of observation group trended to decrease; (3) Adhesion molecules in serum: compared with adhesion molecule contents in serum of control group, sICAM-1 and sVCAM-1 contents in serum of observation group were lower.Conclusion: Selective laser melting deposition cobalt chromium alloy porcelain crown restoration is helpful to relieve inflammatory response of gingival tissue, with expression of decreased generation of inflammatory cytokines and adhesion molecules; it’s an ideal material for crown restoration.

  19. Measuring expression levels of small regulatory RNA molecules from body fluids and formalin-fixed, paraffin-embedded samples.

    Science.gov (United States)

    Gyongyosi, Adrienn; Docs, Otto; Czimmerer, Zsolt; Orosz, Laszlo; Horvath, Attila; Török, Olga; Mehes, Gabor; Nagy, Laszlo; Balint, Balint L

    2014-01-01

    MicroRNAs are involved in the regulation of various pathophysiological processes such as immune regulation and cancer. Next-generation sequencing methods enable us to monitor their presence in various types of samples but we need flexible methods for validating datasets generated by high-throughput methods. Here we describe the detailed protocols to be used with our MiRNA Primer Design Tool assay design system. The presented methods allow the flexible design of the oligonucleotides needed for the RT-qPCR detection of any variant of small regulatory RNA molecules from virtually any species. This method can be used to measure miRNA levels from formalin-fixed, paraffin-embedded (FFPE) samples and various body fluids. As an example, we show the results of the hsa-miR-515-3p, hsa-miR-325, and hsa-miR-155 quantification using a specific UPL probe (Universal Probe Library) and a stem-loop RT-qPCR assay. The small nucleolar RNA RNU43 is used as endogenous control for normalization of the results. Urine from healthy pregnant women and FFPE samples from patients diagnosed with colorectal cancer and treated with antibody-based anti-EGFR monotherapy were used as samples.

  20. From global proteome profiling to single targeted molecules of follicular fluid and oocyte: contribution to embryo development and IVF outcome.

    Science.gov (United States)

    Benkhalifa, Moncef; Madkour, Aicha; Louanjli, Noureddine; Bouamoud, Nouzha; Saadani, Brahim; Kaarouch, Ismail; Chahine, Hikmat; Sefrioui, Omar; Merviel, Philippe; Copin, Henri

    2015-08-01

    The development of in vitro fertilization (IVF) techniques for infertility management has led to the investigation of the proteome of follicular fluid and oocyte. In addition, different markers contributing to oocyte maturation and embryo development potential have been reported in the literature. Different techniques were utilized to analyze whole proteome or single protein markers in follicular fluid and oocytes, particularly in animal models. Data from several studies have generated large amounts of information, however, an ideal profile to predict the best oocytes and embryos suitable for implantation are still to be uncovered. The identification of such profiles and markers from follicular fluid, oocytes and endometrium should help scientists and clinicians develop better strategies to improving clinical outcome of IVF cycles.

  1. Supercritical fluid reverse micelle separation

    Science.gov (United States)

    Fulton, John L.; Smith, Richard D.

    1993-01-01

    A method of separating solute material from a polar fluid in a first polar fluid phase is provided. The method comprises combining a polar fluid, a second fluid that is a gas at standard temperature and pressure and has a critical density, and a surfactant. The solute material is dissolved in the polar fluid to define the first polar fluid phase. The combined polar and second fluids, surfactant, and solute material dissolved in the polar fluid is maintained under near critical or supercritical temperature and pressure conditions such that the density of the second fluid exceeds the critical density thereof. In this way, a reverse micelle system defining a reverse micelle solvent is formed which comprises a continuous phase in the second fluid and a plurality of reverse micelles dispersed in the continuous phase. The solute material is dissolved in the polar fluid and is in chemical equilibrium with the reverse micelles. The first polar fluid phase and the continuous phase are immiscible. The reverse micelles each comprise a dynamic aggregate of surfactant molecules surrounding a core of the polar fluid. The reverse micelle solvent has a polar fluid-to-surfactant molar ratio W, which can vary over a range having a maximum ratio W.sub.o that determines the maximum size of the reverse micelles. The maximum ratio W.sub.o of the reverse micelle solvent is then varied, and the solute material from the first polar fluid phase is transported into the reverse micelles in the continuous phase at an extraction efficiency determined by the critical or supercritical conditions.

  2. Supercritical fluid reverse micelle separation

    Science.gov (United States)

    Fulton, J.L.; Smith, R.D.

    1993-11-30

    A method of separating solute material from a polar fluid in a first polar fluid phase is provided. The method comprises combining a polar fluid, a second fluid that is a gas at standard temperature and pressure and has a critical density, and a surfactant. The solute material is dissolved in the polar fluid to define the first polar fluid phase. The combined polar and second fluids, surfactant, and solute material dissolved in the polar fluid is maintained under near critical or supercritical temperature and pressure conditions such that the density of the second fluid exceeds the critical density thereof. In this way, a reverse micelle system defining a reverse micelle solvent is formed which comprises a continuous phase in the second fluid and a plurality of reverse micelles dispersed in the continuous phase. The solute material is dissolved in the polar fluid and is in chemical equilibrium with the reverse micelles. The first polar fluid phase and the continuous phase are immiscible. The reverse micelles each comprise a dynamic aggregate of surfactant molecules surrounding a core of the polar fluid. The reverse micelle solvent has a polar fluid-to-surfactant molar ratio W, which can vary over a range having a maximum ratio W[sub o] that determines the maximum size of the reverse micelles. The maximum ratio W[sub o] of the reverse micelle solvent is then varied, and the solute material from the first polar fluid phase is transported into the reverse micelles in the continuous phase at an extraction efficiency determined by the critical or supercritical conditions. 27 figures.

  3. Practices Surrounding Event Photos

    NARCIS (Netherlands)

    Vyas, Dhaval; Nijholt, Antinus; van der Veer, Gerrit C.; Kotzé, P.; Marsden, G.; Lindgaard, G.; Wesson, J.; Winckler, M.

    Sharing photos through mobile devices has a great potential for creating shared experiences of social events between co-located as well as remote participants. In order to design novel event sharing tools, we need to develop indepth understanding of current practices surrounding these so called

  4. Theoretical treatment of the thermophysical properties of fluids containing chain-like molecules. Final technical report, June 1, 1994--May 31, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Hall, C.K.

    1997-12-31

    The author has been engaged in a research program aimed at enhancing the understanding of the thermo-physical properties of fluids containing long, flexible, chain-like molecules. She has been working on four main fronts: (1) the development of an equation of state that is capable of predicting the experimentally observed thermodynamic properties, including phase equilibria, of fluids containing chain-like molecules ranging in length from alkanes to polymers; (2) computer simulation studies of the transport properties of chain fluids, with special focus on the role played by entanglements in the dynamical properties of polymer melts, (3) computer simulation studies and theoretical treatment of the static and dynamic properties of polymer networks and gels, and (4) computer simulation studies of the permeation of penetrants in polymer membranes. The theories resulting from this research could eventually serve as the foundation upon which to build correlations of petroleum and natural gas, as well as of polymer solutions, melts, blends, networks, and gels. In this progress report the author summarizes work accomplished under DOE sponsorship of the period December 1993 to December 1996. In section 2, she summarizes the stated objectives of their previous (1993) proposal, indicating which work has been accomplished, which work is continuing, and which work has been discontinued. In section 3, she summarizes the three new objectives that were added after December 1993. In section 4, she provides a detailed description of the work accomplished, omitting those descriptions that appear in the accompanying proposal. In section 5, she describes their human resource development efforts. Finally, in section 6 she lists the publications resulting from this work. Abstracts of these papers are presented in the appendix.

  5. The Self-Diffusion Coefficient of Bulk Fluid Molecules Probed by Transverse Relaxation Measurements in an Inhomogeneous Magnetic Field

    OpenAIRE

    Blokkdal, Espen Hagen

    2014-01-01

    The possibility for performing self-diffusion measurements by Carr-Purcell-Meiboom-Gill (CPMG) experiments using the inherent magnetic field inhomogeneities as a gradient field were tested for six sample molecules, using a Maran Ultra NMR instrument with a 0.5 T permanent magnet. The method tested assumed that the magnetic field inhomogeneities could be approximated by a linear gradient, and the estimated parameter representing the magnetic field inhomogeneities in this model have been estima...

  6. Magnetic resonance of magnetic fluid and magnetoliposome preparations

    Energy Technology Data Exchange (ETDEWEB)

    Morais, Paulo C. [Universidade de Brasilia, Instituto de Fisica, Nucleo de Fisica Aplicada, 70919-970 Brasilia-DF (Brazil)]. E-mail: pcmor@unb.br; Santos, Judes G. [Universidade de Brasilia, Instituto de Fisica, Nucleo de Fisica Aplicada, 70919-970 Brasilia-DF (Brazil); Skeff Neto, K. [Universidade de Brasilia, Instituto de Fisica, Nucleo de Fisica Aplicada, 70919-970 Brasilia-DF (Brazil); Pelegrini, Fernando [Universidade Federal de Goias, Instituto de Fisica, 74001-970 Goiania-GO (Brazil); Cuyper, Marcel de [Katholieke Universiteit Leuven, Campus Kortrijk, Interdisciplinary Research Centre, B-8500 Kortrijk (Belgium)

    2005-05-15

    In this study, magnetic resonance was used to investigate lauric acid-coated magnetite-based magnetic fluid particles and particles which are surrounded by a double layer of phospholipid molecules (magnetoliposomes). The data reveal the presence of monomers and dimers in both samples. Whereas evidence for a thermally induced disruption of dimers is found in the magnetic fluid, apparently, the bilayer phospholipid envelop prevents the dissociation in the magnetoliposome samples.

  7. Amniotic fluid (image)

    Science.gov (United States)

    Amniotic fluid surrounds the growing fetus in the womb and protects the fetus from injury and temperature changes. ... of fetal movement and permits musculoskeletal development. The amniotic fluid can be withdrawn in a procedure called amniocentsis ...

  8. Pericardial fluid Gram stain

    Science.gov (United States)

    ... staining a sample of fluid taken from the pericardium. This is the sac surrounding the heart to ... sample of fluid will be taken from the pericardium. This is done through a procedure called pericardiocentesis . ...

  9. Grape waste extract obtained by supercritical fluid extraction contains bioactive antioxidant molecules and induces antiproliferative effects in human colon adenocarcinoma cells.

    Science.gov (United States)

    Lazzè, Maria Claudia; Pizzala, Roberto; Gutiérrez Pecharromán, Francisco Javier; Gatòn Garnica, Paloma; Antolín Rodríguez, Juan Manuel; Fabris, Nicola; Bianchi, Livia

    2009-06-01

    Grape waste management is one of the main problems of winery industries, but, conversely, grape waste contains a high amount of polyphenols that might protect against human diseases related to oxidative stress, such as colorectal cancer. Therefore, the aim of this work was to investigate the antioxidant and antiproliferative activities of a grape waste extract obtained by supercritical fluid extraction. Because the beneficial effect of grape is related to its content of polyphenolic molecules, the extract was chemically characterized by high-performance liquid chromatography in order to assess its major bioactive components. The antioxidant activity of the grape extract was determined. The results showed that the grape extract presents a strong antiradical activity in the in vitro 2,2-diphenyl-1-picrylhydrazyl radical assay and protects against reactive oxygen species production in human colon adenocarcinoma cells (Caco-2). In contrast, the extract did not protect in the citronellal thermooxidation system and showed a weak protective action against lipid peroxidation in Caco-2 cells. The clonogenic assay and the cell cycle distribution analysis showed that the grape extract has a significant antiproliferative effect in a tumor cell line. These data indicate that grape extract is a promising product to be used as an anti-free radical agent and could exert a chemopreventive action.

  10. Clinical Application of Surrounding Puncture

    Institute of Scientific and Technical Information of China (English)

    GUO Yao-jie; HAN Chou-ping

    2003-01-01

    Surrounding puncture can stop pathogenic qi from spreading, consolidate the connection between local meridians and enrich local qi and blood, which can eventually supplement anti-pathogenic qi and remove pathogenic qi, and consequently remedy diseases. The author of this article summrized and analyzed the clinical application of surrounding puncture for the purpose of studying this technique and improving the therapeutic effect.

  11. Visual surround suppression in schizophrenia

    Directory of Open Access Journals (Sweden)

    Marc Samuel Tibber

    2013-02-01

    Full Text Available Compared to unaffected observers patients with schizophrenia show characteristic differences in visual perception, including a reduced susceptibility to the influence of context on judgements of contrast - a manifestation of weaker surround suppression. To examine the generality of this phenomenon we measured the ability of 24 individuals with schizophrenia to judge the luminance, contrast, orientation and size of targets embedded in contextual surrounds that would typically influence the target’s appearance. Individuals with schizophrenia demonstrated weaker surround suppression compared to matched controls for stimuli defined by contrast or size, but not for those defined by luminance or orientation. As perceived luminance is thought to be regulated at the earliest stages of visual processing our findings are consistent with a suppression deficit that is predominantly cortical in origin. In addition, we propose that preserved orientation surround suppression in schizophrenia may reflect the sparing of broadly tuned mechanisms of suppression. We attempt to reconcile these data with findings from previous studies.

  12. Educational Success and Surrounding Culture

    Science.gov (United States)

    Walters, Garrison

    2016-01-01

    The curriculum, instruction, and services we provide in schools, colleges, and universities matter a lot, but if we continue to ignore our students' "surrounding culture," progress toward a more educated nation will continue to be disappointing.

  13. Educational Success and Surrounding Culture

    Science.gov (United States)

    Walters, Garrison

    2016-01-01

    The curriculum, instruction, and services we provide in schools, colleges, and universities matter a lot, but if we continue to ignore our students' "surrounding culture," progress toward a more educated nation will continue to be disappointing.

  14. Multichannel spatial surround sound system

    Institute of Scientific and Technical Information of China (English)

    RAO Dan; XIE Bosun

    2004-01-01

    Based on the consideration of being compatible with 5.1 channel horizontal surround sound system, a spatial surround sound system is proposed. Theoretical and experimental results show that the system has a wide listening area. It can not only recreate stable image in the front and rear direction, but also eliminate the defect of poor lateral image of 5.1 channel system. The system can be used to reproduce special 3D sound effect and the spaciousness of hall.

  15. Pericardial fluid culture

    Science.gov (United States)

    ... the thin sac that surrounds the heart (the pericardium). A small amount of fluid is removed. You ... may be due to an infection of the pericardium. The specific organism causing the infection may be ...

  16. Molecule capture by olfactory antennules: mantis shrimp.

    Science.gov (United States)

    Stacey, Mark T; Mead, Kristina S; Koehl, Mimi A R

    2002-01-01

    A critical step in the process of olfaction is the movement of odorant molecules from the environment to the surface of a chemosensory structure. Many marine crustaceans capture odorant molecules with arrays of chemosensory sensilla (aesthetascs) on antennules that they flick through the water. We developed a model to calculate molecule flux to the surfaces of aesthetascs in order to study how the size, aesthetasc spacing, and flick kinematics of olfactory antennules affect their performance in capturing molecules from the surrounding water. Since the three-dimensional geometry of an aesthetasc-bearing antennule is complex, dynamically-scaled physical models can often provide an efficient method of determining the fluid velocity field through the array. Here we present a method to optimize the incorporation of such measured velocity vector fields into a numerical simulation of the advection and diffusion of odorants to aesthetasc surfaces. Furthermore, unlike earlier models of odorant interception by antennae, our model incorporates odorant concentration distributions that have been measured in turbulent ambient flows. By applying our model to the example of the olfactory antennules of mantis shrimp, we learned that flicking velocity can have profound effects on odorant flux to the aesthetascs if they operate in the speed range in which the leakiness of the gaps between the aesthetascs to fluid movement is sensitive to velocity. This sensitivity creates an asymmetry in molecule fluxes between outstroke and return stroke, which results in an antennule taking discrete samples in space and time, i.e. "sniffing". As stomatopods grow and their aesthetasc Reynolds number increases, the aesthetasc arrangement on the antennule changes in a way that maintains these asymmetries in leakiness and molecule flux between the outstroke and return stroke, allowing the individual to continue to take discrete samples as it develops.

  17. Visual Surround Suppression in Schizophrenia

    Science.gov (United States)

    Tibber, Marc S.; Anderson, Elaine J.; Bobin, Tracy; Antonova, Elena; Seabright, Alice; Wright, Bernice; Carlin, Patricia; Shergill, Sukhwinder S.; Dakin, Steven C.

    2013-01-01

    Compared to unaffected observers patients with schizophrenia (SZ) show characteristic differences in visual perception, including a reduced susceptibility to the influence of context on judgments of contrast – a manifestation of weaker surround suppression (SS). To examine the generality of this phenomenon we measured the ability of 24 individuals with SZ to judge the luminance, contrast, orientation, and size of targets embedded in contextual surrounds that would typically influence the target’s appearance. Individuals with SZ demonstrated weaker SS compared to matched controls for stimuli defined by contrast or size, but not for those defined by luminance or orientation. As perceived luminance is thought to be regulated at the earliest stages of visual processing our findings are consistent with a suppression deficit that is predominantly cortical in origin. In addition, we propose that preserved orientation SS in SZ may reflect the sparing of broadly tuned mechanisms of suppression. We attempt to reconcile these data with findings from previous studies. PMID:23450069

  18. Effects of fluid resuscitation methods on the pro- and anti-inflammatory cytokines and expression of adhesion molecules after burn injury.

    Science.gov (United States)

    Foldi, Viktor; Lantos, Janos; Bogar, Lajos; Roth, Elizabeth; Weber, Gyorgy; Csontos, Csaba

    2010-01-01

    Fluid resuscitation management can influence inflammatory response after burn injury. The aim of this study was to analyze the effects of two fluid resuscitation methods on the cytokine production and on the expression of the leukocyte surface markers. Thirty patients were included in this prospective randomized study with burn injury affecting more than 20% of the body surface area. Fluid resuscitation was guided by hourly urine output (HUO, n = 15) or by intrathoracic blood volume index (ITBVI, n = 15). Blood samples were taken on admission and on the next five consecutive mornings. Concentrations of interleukin (IL)-1beta, IL-6, IL-8, IL-10, IL-12p70, and tumor necrosis factor-alpha were measured in phorbol myristate acetate-stimulated and -nonstimulated samples. Leukocyte surface marker expressions (CD11a, CD11b, CD14, CD18, CD49d, and CD97) were also determined. In the ITBVI group, IL-6 levels on days 2 to 3 and IL-6/IL-10 ratios on days 2 to 3, and the IL-8/IL-10 ratios on days 3 to 5 were significantly higher than those in HUO group (P burned patients suppresses the shift toward anti-inflammatory imbalance and the expression of leukocyte surface markers more than HUO-guided resuscitation.

  19. Kinetic multi-layer model of the epithelial lining fluid (KM-ELF): Reactions of ozone and OH with antioxidants and surfactant molecules

    Science.gov (United States)

    Lakey, Pascale; Pöschl, Ulrich; Shiraiwa, Manabu

    2015-04-01

    Oxidants cause damage to biosurfaces such as the lung epithelium unless they are effectively scavenged. The respiratory tract is covered in a thin layer of fluid which extends from the nasal cavity to the alveoli and contain species that scavenge ozone and other incoming oxidants. The kinetic multi-layer model of the epithelial lining fluid (KM-ELF) has been developed in order to investigate the reactions of ozone and OH with antioxidants (ascorbate, uric acid, glutathione and α-tocopherol) and surfactant lipids and proteins within the epithelial lining fluid (ELF). The model incorporates different processes: gas phase diffusion, adsorption and desorption from the surface, bulk phase diffusion and known reactions at the surface and in the bulk. The ELF is split into many layers: a sorption layer, a surfactant layer, a near surface bulk layer and several bulk layers. Initial results using KM-ELF indicate that at ELF thicknesses of 80 nm and 1 × 10-4cm the ELF would become rapidly saturated with ozone with saturation occurring in less than a second. However, at an ELF thickness of 1 × 10-3cm concentration gradients were observed throughout the ELF and the presence of antioxidants reduced the O3 reaching the lung cells and tissues by 40% after 1 hour of exposure. In contrast, the antioxidants were efficient scavengers of OH radicals, although the large rate constants of OH reacting with the antioxidants resulted in the antioxidants decaying away rapidly. The chemical half-lives of the antioxidants and surface species were also calculated using KM-ELF as a function of O3 and OH concentration and ELF thickness. Finally, the pH dependence of the products of reactions between antioxidants and O3 were investigated. The KM-ELF model predicted that a harmful ascorbate ozonide product would increase from 1.4 × 1011cm-3at pH 7.4 to 1.1 × 1014 cm-3 at pH 4after 1 hour although a uric acid ozonide product would decrease from 2.0 × 1015cm-3to 5.9 × 1012cm-3.

  20. Nanostructure sensor of presence and concentration of a target molecule

    Science.gov (United States)

    Schipper, John F. (Inventor)

    2009-01-01

    Method and system (i) to determine when a selected target molecule is present or absent in a fluid, (2) to estimate concentration of the target molecule in the fluid and (3) estimate possible presence of a second (different) target molecule in the fluid, by analyzing differences in resonant frequencies of vibration of a thin beam suspended in the fluid, after the fluid has moved across the beam.

  1. Binaural Rendering in MPEG Surround

    Directory of Open Access Journals (Sweden)

    Kristofer Kjörling

    2008-04-01

    Full Text Available This paper describes novel methods for evoking a multichannel audio experience over stereo headphones. In contrast to the conventional convolution-based approach where, for example, five input channels are filtered using ten head-related transfer functions, the current approach is based on a parametric representation of the multichannel signal, along with either a parametric representation of the head-related transfer functions or a reduced set of head-related transfer functions. An audio scene with multiple virtual sound sources is represented by a mono or a stereo downmix signal of all sound source signals, accompanied by certain statistical (spatial properties. These statistical properties of the sound sources are either combined with statistical properties of head-related transfer functions to estimate “binaural parameters” that represent the perceptually relevant aspects of the auditory scene or used to create a limited set of combined head-related transfer functions that can be applied directly on the downmix signal. Subsequently, a binaural rendering stage reinstates the statistical properties of the sound sources by applying the estimated binaural parameters or the reduced set of combined head-related transfer functions directly on the downmix. If combined with parametric multichannel audio coders such as MPEG Surround, the proposed methods are advantageous over conventional methods in terms of perceived quality and computational complexity.

  2. Reduced surround inhibition in musicians.

    Science.gov (United States)

    Shin, Hae-Won; Kang, Suk Y; Hallett, Mark; Sohn, Young H

    2012-06-01

    To investigate whether surround inhibition (SI) in the motor system is altered in professional musicians, we performed a transcranial magnetic stimulation (TMS) study in 10 professional musicians and 15 age-matched healthy non-musicians. TMS was set to be triggered by self-initiated flexion of the index finger at different intervals ranging from 3 to 1,000 ms. Average motor evoked potential (MEP) amplitudes obtained from self-triggered TMS were normalized to average MEPs of the control TMS at rest and expressed as a percentage. Normalized MEP amplitudes of the abductor digiti minimi (ADM) muscles were compared between the musicians and non-musicians with the primary analysis being the intervals between 3 and 80 ms (during the movement). A mixed-design ANOVA revealed a significant difference in normalized ADM MEPs during the index finger flexion between groups, with less SI in the musicians. This study demonstrated that the functional operation of SI is less strong in musicians than non-musicians, perhaps due to practice of movement synergies involving both muscles. Reduced SI, however, could lead susceptible musicians to be prone to develop task-specific dystonia.

  3. Binaural Rendering in MPEG Surround

    Science.gov (United States)

    Breebaart, Jeroen; Villemoes, Lars; Kjörling, Kristofer

    2008-12-01

    This paper describes novel methods for evoking a multichannel audio experience over stereo headphones. In contrast to the conventional convolution-based approach where, for example, five input channels are filtered using ten head-related transfer functions, the current approach is based on a parametric representation of the multichannel signal, along with either a parametric representation of the head-related transfer functions or a reduced set of head-related transfer functions. An audio scene with multiple virtual sound sources is represented by a mono or a stereo downmix signal of all sound source signals, accompanied by certain statistical (spatial) properties. These statistical properties of the sound sources are either combined with statistical properties of head-related transfer functions to estimate "binaural parameters" that represent the perceptually relevant aspects of the auditory scene or used to create a limited set of combined head-related transfer functions that can be applied directly on the downmix signal. Subsequently, a binaural rendering stage reinstates the statistical properties of the sound sources by applying the estimated binaural parameters or the reduced set of combined head-related transfer functions directly on the downmix. If combined with parametric multichannel audio coders such as MPEG Surround, the proposed methods are advantageous over conventional methods in terms of perceived quality and computational complexity.

  4. Fully Streched Single DNA Molecules in a Nanofluidic Chip Show Large-Scale Structural Variation

    DEFF Research Database (Denmark)

    Pedersen, Jonas Nyvold; Marie, Rodolphe; Bauer, D. L.

    2013-01-01

    When stretching and imaging DNA molecules in nanofluidic devices, it is important to know the relation between the physical length as measured in the lab and the distance along the contour of the DNA. Here a single DNA molecule longer than 1 Mbp is loaded into a nanofluidic device consisting of two...... crossing nanoslits (85nm x 50 microns) connected to microchannels. An applied pressure creates a stagnation point at the crossing of the nanoslits. The drag force from the fluid stretches the DNA. We determine the degree of stretching of the molecule (i) without the use of markers, (ii) without knowing...... the contour length of the DNA, and (iii) without having the full DNA molecule inside the field-of-view. The analysis is based on the transverse motion of the DNA due its Brownian motion, i.e. the DNA's response to the thermal fluctuations of the liquid surrounding it. The parameter values obtained by fitting...

  5. Fluid viscosity under confined conditions

    Science.gov (United States)

    Rudyak, V. Ya.; Belkin, A. A.

    2014-12-01

    Closed equations of fluid transfer in confined conditions are constructed in this study using ab initio methods of nonequilibrium statistical mechanics. It is shown that the fluid viscosity is not determined by the fluid properties alone, but becomes a property of the "fluid-nanochannel walls" system as a whole. Relations for the tensor of stresses and the interphase force, which specifies the exchange by momentum of fluid molecules with the channel-wall molecules, are derived. It is shown that the coefficient of viscosity is now determined by the sum of three contributions. The first contribution coincides with the expression for the coefficient of the viscosity of fluid in the bulk being specified by the interaction of fluid molecules with each other. The second contribution has the same structure as the first one but is determined by the interaction of fluid molecules with the channel-wall molecules. Finally, the third contribution has no analog in the usual statistical mechanics of transport processes of a simple fluid. It is associated with the correlation of intermolecular forces of the fluid and the channel walls. Thus, it is established that the coefficient of viscosity of fluid in sufficiently small channels will substantially differ from its bulk value.

  6. Molecule nanoweaver

    Science.gov (United States)

    Gerald, II; Rex E.; Klingler, Robert J.; Rathke, Jerome W.; Diaz, Rocio; Vukovic, Lela

    2009-03-10

    A method, apparatus, and system for constructing uniform macroscopic films with tailored geometric assemblies of molecules on the nanometer scale. The method, apparatus, and system include providing starting molecules of selected character, applying one or more force fields to the molecules to cause them to order and condense with NMR spectra and images being used to monitor progress in creating the desired geometrical assembly and functionality of molecules that comprise the films.

  7. Physics of Fluids

    OpenAIRE

    2007-01-01

    Periodic motion of three stirrers in a two-dimensional flow can lead to chaotic transport of the surrounding fluid. For certain stirrer motions, the generation of chaos is guaranteed solely by the topology of that motion and continuity of the fluid. Work in this area has focused largely on using physical rods as stirrers, but the theory also applies when the "stirrers" are passive fluid particles. We demonstrate the occurrence of topological chaos for Stokes flow in a two-dimensional lid-driv...

  8. Electrorheological fluids and methods

    Energy Technology Data Exchange (ETDEWEB)

    Green, Peter F.; McIntyre, Ernest C.

    2015-06-02

    Electrorheological fluids and methods include changes in liquid-like materials that can flow like milk and subsequently form solid-like structures under applied electric fields; e.g., about 1 kV/mm. Such fluids can be used in various ways as smart suspensions, including uses in automotive, defense, and civil engineering applications. Electrorheological fluids and methods include one or more polar molecule substituted polyhedral silsesquioxanes (e.g., sulfonated polyhedral silsesquioxanes) and one or more oils (e.g., silicone oil), where the fluid can be subjected to an electric field.

  9. Dynamics of two-component membranes surrounded by viscoelastic media.

    Science.gov (United States)

    Komura, Shigeyuki; Yasuda, Kento; Okamoto, Ryuichi

    2015-11-01

    We discuss the dynamics of two-component fluid membranes which are surrounded by viscoelastic media. We assume that membrane-embedded proteins can diffuse laterally and induce a local membrane curvature. The mean squared displacement of a tagged membrane segment is obtained as a generalized Einstein relation. When the elasticity of the surrounding media obeys a power-law behavior in frequency, an anomalous diffusion of the membrane segment is predicted. We also consider the situation where the proteins generate active non-equilibrium forces. The generalized Einstein relation is further modified by an effective temperature that depends on the force dipole energy. The obtained generalized Einstein relations are useful for membrane microrheology experiments.

  10. Contour detection by surround suppression of texture

    NARCIS (Netherlands)

    Petkov, Nicolai; Tavares, JMRS; Jorge, RMN

    2007-01-01

    Based on a keynote lecture at Complmage 2006, Coimbra, Oct. 20-21, 2006, an overview is given of our activities in modelling and using surround inhibition for contour detection. The effect of suppression of a line or edge stimulus by similar surrounding stimuli is known from visual perception studie

  11. Refrigerating fluids; Fluides frigorigenes

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1999-03-01

    Refrigerating fluids are experiencing a real revolution since few years. CFCs with their destructive effect on the ozone layer are now prohibited while HCFCs will be progressively eliminated and replaced by HFCs. However, HFCs can contribute to the increase of the greenhouse effect. The solutions proposed by thermal engineering professionals consist in the confinement of air-conditioning installations (elimination of recurrent leaks) and in the improvement of installations efficiency. HCFC fluids like the R 22 are still widely used in air-conditioning but they are supposed to be replaced by HFC fluids like the R 134a, the R 407C or the R 410A. This short paper gives a brief presentation of these fluids and of their chemical characteristics. (J.S.)

  12. Experimental and Numerical Study on Modal Dynamic Response of Water-Surrounded Slender Bridge Pier with Pile Foundation

    National Research Council Canada - National Science Library

    Yulin Deng; Qingkang Guo; Lueqin Xu

    2017-01-01

      This paper presents an experimental program performed to study the effect of fluid-structure interaction on the modal dynamic response of water-surrounded slender bridge pier with pile foundation...

  13. Atkins' molecules

    CERN Document Server

    Atkins, Peters

    2003-01-01

    Originally published in 2003, this is the second edition of a title that was called 'the most beautiful chemistry book ever written'. In it, we see the molecules responsible for the experiences of our everyday life - including fabrics, drugs, plastics, explosives, detergents, fragrances, tastes, and sex. With engaging prose Peter Atkins gives a non-technical account of an incredible range of aspects of the world around us, showing unexpected connections, and giving an insight into how this amazing world can be understood in terms of the atoms and molecules from which it is built. The second edition includes dozens of extra molecules, graphical presentation, and an even more accessible and enthralling account of the molecules themselves.

  14. Enumerating molecules.

    Energy Technology Data Exchange (ETDEWEB)

    Visco, Donald Patrick, Jr. (, . Tennessee Technological University, Cookeville, TN); Faulon, Jean-Loup Michel; Roe, Diana C.

    2004-04-01

    This report is a comprehensive review of the field of molecular enumeration from early isomer counting theories to evolutionary algorithms that design molecules in silico. The core of the review is a detail account on how molecules are counted, enumerated, and sampled. The practical applications of molecular enumeration are also reviewed for chemical information, structure elucidation, molecular design, and combinatorial library design purposes. This review is to appear as a chapter in Reviews in Computational Chemistry volume 21 edited by Kenny B. Lipkowitz.

  15. Agroforestry practice in villages surrounding Nyamure former ...

    African Journals Online (AJOL)

    cntaganda

    Key words: Agroforestry, fuel wood, tree products, woodlot, forest plantation. INTRODUCTION ... The study area included three administrative cells in the surroundings of Nyamure ..... Table 6: Distance and time spent on firewood collection.

  16. Explaining preferences for home surroundings and locations

    Directory of Open Access Journals (Sweden)

    Hans Skifter Andersen

    2011-01-01

    Full Text Available This article is based on a survey carried out in Denmark that asked a random sample of the population about their preferences for home surroundings and locations. It shows that the characteristics of social surroundings are very important and can be divided into three independent dimensions: avoiding social nuisances, preferring social homogeneity and living close to one’s social network and place of origin. The study shows that most people have many detailed preferences, whereas some have very few. This confirms an earlier theory that some people are very connected to certain places with given characteristics and thus do not have priorities regarding home surroundings and locations. For others, mostly young people and singles, home is just a place to sleep and relax, whereas life is lived elsewhere. For this group, there are only preferences for location and there are few specific preferences for surroundings.

  17. Surround-Masking Affects Visual Estimation Ability

    Science.gov (United States)

    Jastrzebski, Nicola R.; Hugrass, Laila E.; Crewther, Sheila G.; Crewther, David P.

    2017-01-01

    Visual estimation of numerosity involves the discrimination of magnitude between two distributions or perceptual sets that vary in number of elements. How performance on such estimation depends on peripheral sensory stimulation is unclear, even in typically developing adults. Here, we varied the central and surround contrast of stimuli that comprised a visual estimation task in order to determine whether mechanisms involved with the removal of unessential visual input functionally contributes toward number acuity. The visual estimation judgments of typically developed adults were significantly impaired for high but not low contrast surround stimulus conditions. The center and surround contrasts of the stimuli also differentially affected the accuracy of numerosity estimation depending on whether fewer or more dots were presented. Remarkably, observers demonstrated the highest mean percentage accuracy across stimulus conditions in the discrimination of more elements when the surround contrast was low and the background luminance of the central region containing the elements was dark (black center). Conversely, accuracy was severely impaired during the discrimination of fewer elements when the surround contrast was high and the background luminance of the central region was mid level (gray center). These findings suggest that estimation ability is functionally related to the quality of low-order filtration of unessential visual information. These surround masking results may help understanding of the poor visual estimation ability commonly observed in developmental dyscalculia.

  18. Amniotic fluid

    Science.gov (United States)

    ... carefully. Removing a sample of the fluid through amniocentesis can provide information about the sex, health, and development of the fetus. Images Amniocentesis Amniotic fluid Polyhydramnios Amniotic fluid References Cunningham FG, ...

  19. Undulatory swimming in viscoelastic fluids

    CERN Document Server

    Shen, Xiaoning

    2011-01-01

    The effects of fluid elasticity on the swimming behavior of the nematode \\emph{Caenorhabditis elegans} are experimentally investigated by tracking the nematode's motion and measuring the corresponding velocity fields. We find that fluid elasticity hinders self-propulsion. Compared to Newtonian solutions, fluid elasticity leads to 35% slower propulsion speed. Furthermore, self-propulsion decreases as elastic stresses grow in magnitude in the fluid. This decrease in self-propulsion in viscoelastic fluids is related to the stretching of flexible molecules near hyperbolic points in the flow.

  20. Undulatory swimming in viscoelastic fluids.

    Science.gov (United States)

    Shen, X N; Arratia, P E

    2011-05-20

    The effects of fluid elasticity on the swimming behavior of the nematode Caenorhabditis elegans are experimentally investigated by tracking the nematode's motion and measuring the corresponding velocity fields. We find that fluid elasticity hinders self-propulsion. Compared to Newtonian solutions, fluid elasticity leads to up to 35% slower propulsion. Furthermore, self-propulsion decreases as elastic stresses grow in magnitude in the fluid. This decrease in self-propulsion in viscoelastic fluids is related to the stretching of flexible molecules near hyperbolic points in the flow.

  1. Smart Chips for Smart Surroundings - 4S

    NARCIS (Netherlands)

    Schuler, Eberhard; König, Ralf; Becker, Jürgen; Rauwerda, Gerard; Burgwal, van de Marcel; Smit, Gerard J.M.; Cardoso, João M.P.; Hübner, Michael

    2011-01-01

    The overall mission of the 4S project (Smart Chips for Smart Surroundings) was to define and develop efficient flexible, reconfigurable core building blocks, including the supporting tools, for future Ambient System Devices. Reconfigurability offers the needed flexibility and adaptability, it provid

  2. Osmosis and solute-solvent drag: fluid transport and fluid exchange in animals and plants.

    Science.gov (United States)

    Hammel, H T; Schlegel, Whitney M

    2005-01-01

    In 1903, George Hulett explained how solute alters water in an aqueous solution to lower the vapor pressure of its water. Hulett also explained how the same altered water causes osmosis and osmotic pressure when the solution is separated from liquid water by a membrane permeable to the water only. Hulett recognized that the solute molecules diffuse toward all boundaries of the solution containing the solute. Solute diffusion is stopped at all boundaries, at an open-unopposed surface of the solution, at a semipermeable membrane, at a container wall, or at the boundary of a solid or gaseous inclusion surrounded by solution but not dissolved in it. At each boundary of the solution, the solute molecules are reflected, they change momentum, and the change of momentum of all reflected molecules is a pressure, a solute pressure (i.e., a force on a unit area of reflecting boundary). When a boundary of the solution is open and unopposed, the solute pressure alters the internal tension in the force bonding the water in its liquid phase, namely, the hydrogen bond. All altered properties of the water in the solution are explained by the altered internal tension of the water in the solution. We acclaim Hulett's explanation of osmosis, osmotic pressure, and lowering of the vapor pressure of water in an aqueous solution. His explanation is self-evident. It is the necessary, sufficient, and inescapable explanation of all altered properties of the water in the solution relative to the same property of pure liquid water at the same externally applied pressure and the same temperature. We extend Hulett's explanation of osmosis to include the osmotic effects of solute diffusing through solvent and dragging on the solvent through which it diffuses. Therein lies the explanations of (1) the extravasation from and return of interstitial fluid to capillaries, (2) the return of luminal fluid in the proximal and distal convoluted tubules of a kidney nephron to their peritubular capillaries

  3. Stresses and Shear Fracture Zone of Jinshazhou Tunnel Surrounding Rock in Rich Water Region

    Institute of Scientific and Technical Information of China (English)

    ZHENG Jun-jie; LOU Xiao-ming

    2008-01-01

    Field evidence has shown that large-scale and unstable discontinuous planes in the rock mass surrounding tunnels in rich water region are probably generated after excavation. The tunnel surrounding rock was divided into three zones, including elastic zone, plastic damage zone and shear fracture zone fof assessing the stability of the tunnel surrounding rock. By local hydrogeology, the stresses of surrounding rock of Jinshazhou circular tunnel was analyzed and the stress solutions on the elastic and plastic damage zones were obtained by applying the theories of fluid-solid coupling and elasto-plastic damage mechanics. The shear fracture zone generated by joints was studied and its range was determined by using Mohr-Coulomb strength criterion. Finally, the correctness of the theoretical results was validated by comparing the scopes of shear fracture zones calculated in this paper with those from literature.

  4. Departure of microscopic friction from macroscopic drag in molecular fluid dynamics

    Science.gov (United States)

    Hanasaki, Itsuo; Fujiwara, Daiki; Kawano, Satoyuki

    2016-03-01

    Friction coefficient of the Langevin equation and drag of spherical macroscopic objects in steady flow at low Reynolds numbers are usually regarded as equivalent. We show that the microscopic friction can be different from the macroscopic drag when the mass is taken into account for particles with comparable scale to the surrounding fluid molecules. We illustrate it numerically by molecular dynamics simulation of chloride ion in water. Friction variation by the atomistic mass effect beyond the Langevin regime can be of use in the drag reduction technology as well as the electro or thermophoresis.

  5. The Interstellar Cloud Surrounding the Solar System

    Science.gov (United States)

    Frisch, P. C.

    Ultraviolet spectral data of nearby stars indicate that the cloud surrounding the solar system has an average neutral density n(HI)~0.1 cm-3, temperature ~6800 K, and turbulence ~1.7 km/s. Comparisons between the anomalous cosmic ray data and ultraviolet data suggest that the electron density is in the range n(e-)~0.22 to 0.44 cm-3. This cloud is flowing past the Sun from a position centered in the Norma-Lupis region. The cloud properties are consistent with interstellar gas which originated as material evaporated from the surfaces of embedded clouds in the Scorpius-Centaurus Association, and which was then displaced towards the Sun by a supernova event about 4 Myrs ago. The Sun and surrounding cloud velocities are nearly perpendicular in space, and this cloud is sweeping past the Sun. The morphology of this cloud can be reconstructed by assuming that the cloud moves in a direction parallel to the surface normal. With this assumption, the Sun entered the surrounding cloud 2000 to 8000 years ago, and is now about 0.05 to 0.16 pc from the cloud surface. Prior to its recent entry into the surrounding cloud complex, the Sun was embedded in a region of space with average density lower than 0.0002 cm-3. If a denser cloud velocity component seen towards alpha Cen A,B is real, it will encounter the solar system within 50,000 yr. The nearby magnetic field seen upwind has a spatial orientation that is parallel to the cloud surface. The nearby star Sirius is viewed through the wake of the solar system, but this direction also samples the hypothetical cloud interface. Comparisons of anomalous cosmic ray and interstellar absorption line data suggest that trace elements in the surrounding cloud are in ionization equilibrium. Data towards nearby white dwarfs indicate partial helium ionization, N(N(HI)(/N(HeI)>~13.7, which is consistent with pickup ion data within the solar system if less than 40% hydrogen ionization occurs in the heliopause region. However, the white dwarfs may

  6. Persistent Confusion and Controversy Surrounding Gene Patents

    Science.gov (United States)

    Guerrini, Christi J.; Majumder, Mary A.; McGuire, Amy L.

    2016-01-01

    There is persistent confusion and controversy surrounding basic issues of patent law relevant to the genomics industry. Uncertainty and conflict can lead to the adoption of inefficient practices and exposure to liability. The development of patent-specific educational resources for industry members, as well as the prompt resolution of patentability rules unsettled by recent U.S. Supreme Court decisions, are therefore urgently needed. PMID:26849516

  7. Fluid Mechanics.

    Science.gov (United States)

    Drazin, Philip

    1987-01-01

    Outlines the contents of Volume II of "Principia" by Sir Isaac Newton. Reviews the contributions of subsequent scientists to the physics of fluid dynamics. Discusses the treatment of fluid mechanics in physics curricula. Highlights a few of the problems of modern research in fluid dynamics. Shows that problems still remain. (CW)

  8. Fluid Interfaces

    DEFF Research Database (Denmark)

    Hansen, Klaus Marius

    2001-01-01

    Fluid interaction, interaction by the user with the system that causes few breakdowns, is essential to many user interfaces. We present two concrete software systems that try to support fluid interaction for different work practices. Furthermore, we present specificity, generality, and minimality...... as design goals for fluid interfaces....

  9. Fluid Mechanics.

    Science.gov (United States)

    Drazin, Philip

    1987-01-01

    Outlines the contents of Volume II of "Principia" by Sir Isaac Newton. Reviews the contributions of subsequent scientists to the physics of fluid dynamics. Discusses the treatment of fluid mechanics in physics curricula. Highlights a few of the problems of modern research in fluid dynamics. Shows that problems still remain. (CW)

  10. Identification of -SiC surrounded by relatable surrounding diamond medium using weak Raman surface phonons

    Indian Academy of Sciences (India)

    Mohan Kumar Kuntumalla; Harish Ojha; Vadali Venkata Satya Siva Srikanth

    2013-11-01

    It is difficult to detect -SiC using micro-Raman scattering, if it is surrounded by carbon medium. Here, -SiC is identified in the presence of a relatable surrounding diamond medium using subtle, but discernible Raman surface phonons. In this study, diamond/-SiC nanocomposite thin film system is considered in which nanosized -SiC crystallites are surrounded by a relatable nanodiamond medium that leads to the appearance of a weak Raman surface phonon band at about 855 cm-1. Change in the nature of the surrounding material structure and its volume content when relatable, will affect the resultant Raman response of -SiC phase as seen in the present case of diamond/-SiC nanocomposite thin films.

  11. Hadron Molecules

    CERN Document Server

    Gutsche, Thomas; Faessler, Amand; Lee, Ian Woo; Lyubovitskij, Valery E

    2010-01-01

    We discuss a possible interpretation of the open charm mesons $D_{s0}^*(2317)$, $D_{s1}(2460)$ and the hidden charm mesons X(3872), Y(3940) and Y(4140) as hadron molecules. Using a phenomenological Lagrangian approach we review the strong and radiative decays of the $D_{s0}^* (2317)$ and $D_{s1}(2460)$ states. The X(3872) is assumed to consist dominantly of molecular hadronic components with an additional small admixture of a charmonium configuration. Determing the radiative ($\\gamma J/\\psi$ and $\\gamma \\psi(2s)$) and strong ($J/\\psi 2\\pi $ and $ J/\\psi 3\\pi$) decay modes we show that present experimental observation is consistent with the molecular structure assumption of the X(3872). Finally we give evidence for molecular interpretations of the Y(3940) and Y(4140) related to the observed strong decay modes $J/\\psi + \\omega$ or $J/\\psi + \\phi$, respectively.

  12. Tumor interstitial fluid

    DEFF Research Database (Denmark)

    Gromov, Pavel; Gromova, Irina; Olsen, Charlotta J.

    2013-01-01

    Tumor interstitial fluid (TIF) is a proximal fluid that, in addition to the set of blood soluble phase-borne proteins, holds a subset of aberrantly externalized components, mainly proteins, released by tumor cells and tumor microenvironment through various mechanisms, which include classical...... secretion, non-classical secretion, secretion via exosomes and membrane protein shedding. Consequently, the interstitial aqueous phase of solid tumors is a highly promising resource for the discovery of molecules associated with pathological changes in tissues. Firstly, it allows one to delve deeper...... into the regulatory mechanisms and functions of secretion-related processes in tumor development. Secondly, the anomalous secretion of molecules that is innate to tumors and the tumor microenvironment, being associated with cancer progression, offers a valuable source for biomarker discovery and possible targets...

  13. Study on mechanism and practice of surrounding rock control of high stress coal roadway

    Institute of Scientific and Technical Information of China (English)

    WANG Wei-jun; YANG Lei; OUYANG Guang-bin

    2006-01-01

    The mechanical principle and surrounding rock deformation feature of high stress coal roadway was analyzed. The condition of stress balance of the kind of the roadway was put forward. The surrounding rock control principle and supporting technique of high stress coal roadway were discussed. It was very important to control early days deformation of coal sides. The supporting strength is should increased, so the strength loss of coal sides is decreased. The range of plastic fluid zone is reduced. The above mention-ned principle is applied in industrial test, and the new supporting technique is applied successfully.

  14. Explaining preferences for home surroundings and locations

    DEFF Research Database (Denmark)

    Andersen, Hans Skifter

    2011-01-01

    : avoiding social nuisances, preferring social homogeneity and living close to one’s social network and place of origin. The study shows that most people have many detailed preferences, whereas some have very few. This confirms an earlier theory that some people are very connected to certain places...... with given characteristics and thus do not have priorities regarding home surroundings and locations. For others, mostly young people and singles, home is just a place to sleep and relax, whereas life is lived elsewhere. For this group, there are only preferences for location and there are few specific...

  15. Capillary condensation of short-chain molecules.

    Science.gov (United States)

    Bryk, Paweł; Pizio, Orest; Sokolowski, Stefan

    2005-05-15

    A density-functional study of capillary condensation of fluids of short-chain molecules confined to slitlike pores is presented. The molecules are modeled as freely jointed tangent spherical segments with a hard core and with short-range attractive interaction between all the segments. We investigate how the critical parameters of capillary condensation of the fluid change when the pore width decreases and eventually becomes smaller than the nominal linear dimension of the single-chain molecule. We find that the dependence of critical parameters for a fluid of dimers and of tetramers on pore width is similar to that of the monomer fluid. On the other hand, for a fluid of chains consisting of a larger number of segments we observe an inversion effect. Namely, the critical temperature of capillary condensation decreases with increasing pore width for a certain interval of values of the pore width. This anomalous behavior is also influenced by the interaction between molecules and pore walls. We attribute this behavior to the effect of conformational changes of molecules upon confinement.

  16. Fluid mechanics

    CERN Document Server

    Kundu, Pijush K; Dowling, David R

    2011-01-01

    Fluid mechanics, the study of how fluids behave and interact under various forces and in various applied situations-whether in the liquid or gaseous state or both-is introduced and comprehensively covered in this widely adopted text. Revised and updated by Dr. David Dowling, Fluid Mechanics, 5e is suitable for both a first or second course in fluid mechanics at the graduate or advanced undergraduate level. Along with more than 100 new figures, the text has been reorganized and consolidated to provide a better flow and more cohesion of topics.Changes made to the

  17. The effect of wind direction and building surroundings on a marina bay in the Black Sea

    Science.gov (United States)

    Katona, Cosmin; Safta, Carmen Anca

    2017-01-01

    The wind effect has usually a major importance in the marina bay. These environmental sites are an interplay between tourist and commercial activities, requiring a high-detailed and definition studies of the dynamic fluid in the harbor. Computational Fluid Dynamics (CFD) has been used elaborately in urban surroundings research. However, most CFD studies were performed for harbors for only a confined number of wind directions and/or without considering the building surroundings effects. This paper presents the results of different simulations based on various wind flows and the CFD simulation of coupled urban wind flow and general wind directions upon a semi-closed area. Thus the importance of wind effects on the evaluation of the marina bay will be pointed out to achieve a safe and secure mooring at the berth and eventually a good potential of renewable energy for an impending green harbor.

  18. Characterizing the Microenvironment Surrounding Phosphorylated Protein Sites

    Institute of Scientific and Technical Information of China (English)

    Shi-Cai Fan; Xue-Gong Zhang

    2005-01-01

    Protein phosphorylation plays an important role in various cellular processes. Due to its high complexity, the mechanism needs to be further studied. In the last few years, many methods have been contributed to this field, but almost all of them investigated the mechanism based on protein sequences around protein sites. In this study, we implement an exploration by characterizing the microenvironment surrounding phosphorylated protein sites with a modified shell model, and obtain some significant properties by the rank-sum test, such as the lack of some classes of residues, atoms, and secondary structures. Furthermore, we find that the depletion of some properties affects protein phosphorylation remarkably. Our results suggest that it is a meaningful direction to explore the mechanism of protein phosphorylation from microenvironment and we expect further findings along with the increasing size of phosphorylation and protein structure data.

  19. Opportunity's Surroundings After Sol 1820 Drive

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,820th to 1,822nd Martian days, or sols, of Opportunity's surface mission (March 7 to 9, 2009). South is at the center; north at both ends. The rover had driven 20.6 meters toward the northwest on Sol 1820 before beginning to take the frames in this view. Tracks from that drive recede southwestward. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and small exposures of lighter-toned bedrock. This view is presented as a cylindrical projection with geometric seam correction.

  20. Exploiting Surrounding Text for Retrieving Web Images

    Directory of Open Access Journals (Sweden)

    S. A. Noah

    2008-01-01

    Full Text Available Web documents contain useful textual information that can be exploited for describing images. Research had been focused on representing images by means of its content (low level description such as color, shape and texture, little research had been directed to exploiting such textual information. The aim of this research was to systematically exploit the textual content of HTML documents for automatically indexing and ranking of images embedded in web documents. A heuristic approach for locating and assigning weight surrounding web images and a modified tf.idf weighting scheme was proposed. Precision-recall measures of evaluation had been conducted for ten queries and promising results had been achieved. The proposed approach showed slightly better precision measure as compared to a popular search engine with an average of 0.63 and 0.55 relative precision measures respectively.

  1. Acoustoelastic effects of Stoneley waves in a borehole surrounded by a transversely isotropic elastic solid

    OpenAIRE

    Jinxia Liu; Zhiwen Cui; Zhengliang Cao; Kexie Wang

    2014-01-01

    Stoneley wave in a fluid-filled pressurized borehole surrounded by a transversely isotropic elastic solid with nine independent third-order elastic constants in presence of biaxial stresses are studied. A simplified acoustoelastic formulation of Stoneley wave is presented for the parallelism of the borehole axis and the formation axis of symmetry. Sensitivity coefficients and velocity dispersions for Stoneley wave due to the presence of stresses are numerically investigated, respectively. The...

  2. Statistical Properties of Thermal Noise Driving the Brownian Particles in Fluids

    Directory of Open Access Journals (Sweden)

    Tóthová Jana

    2016-01-01

    Full Text Available In several recent works high-resolution interferometric detection allowed to study the Brownian motion of optically trapped microparticles in air and fluids. The observed positional fluctuations of the particles are well described by the generalized Langevin equation with the Boussinesq-Basset “history force” instead of the Stokes friction, which is valid only for the steady motion. Recently, also the time correlation function of the thermal random force Fth driving the Brownian particles through collisions with the surrounding molecules has been measured. In the present contribution we propose a method to describe the statistical properties of Fth in incompressible fluids. Our calculations show that the time decay of the correlator 〈Fth(tFth(0〉 is significantly slower than that found in the literature. It is also shown how the “color” of the thermal noise can be determined from the measured positions of the Brownian particles.

  3. From odor molecules to plume tracking: an interdisciplinary, multilevel approach to olfaction in stomatopods.

    Science.gov (United States)

    Mead, Kristina S

    2002-04-01

    Like many marine crustaceans, mantis shrimp rely on their sense of smell to find food, mates, and habitat. In order for olfaction to function, odorant molecules in the surrounding fluid must gain access to the animal's chemosensors. Thus fluid motion is important for olfaction, both in terms of the large scale fluid movements (currents, waves, etc.) that advect the odorants to the vicinity of the sensors, and the small-scale viscosity dominated flows that determine odorant access to the surface of the sensor. In order to understand how stomatopods interpret their chemical environment, I investigated how stomatopod chemosensory morphology and the movement of the structures bearing the chemosensors affect fluid access to the sensor surface in Gonodactylaceus mutatus. Preliminary results from new directions are presented, including mathematical modeling of molecular flux at the sensor surface, field studies of the effects of ambient flow on odor sampling behavior, and flume experiments testing the ability of stomatopods to trace odor plumes. Finally, I show how the use of multiple techniques from several disciplines leads to new ideas about the functional morphology of stomatopod antennules.

  4. Single Molecule Studies on Dynamics in Liquid Crystals

    Directory of Open Access Journals (Sweden)

    Daniela Täuber

    2013-09-01

    Full Text Available Single molecule (SM methods are able to resolve structure related dynamics of guest molecules in liquid crystals (LC. Highly diluted small dye molecules on the one hand explore structure formation and LC dynamics, on the other hand they report about a distortion caused by the guest molecules. The anisotropic structure of LC materials is used to retrieve specific conformation related properties of larger guest molecules like conjugated polymers. This in particular sheds light on organization mechanisms within biological cells, where large molecules are found in nematic LC surroundings. This review gives a short overview related to the application of highly sensitive SM detection schemes in LC.

  5. Fluid Dynamics

    DEFF Research Database (Denmark)

    Brorsen, Michael

    These lecture notes are intended mainly for the 7th semester course "Fluid Dynamics" offered by the Study Committee on Civil Engineering, Aalborg University.......These lecture notes are intended mainly for the 7th semester course "Fluid Dynamics" offered by the Study Committee on Civil Engineering, Aalborg University....

  6. The lithosphere-asthenosphere Italy and surroundings

    CERN Document Server

    Panza, G F; Chimera, G; Pontevivo, A; Raykova, R

    2003-01-01

    The velocity-depth distribution of the lithosphere-asthenosphere in the Italian region and surroundings is imaged, with a lateral resolution of about 100 km, by surface wave velocity tomography and non-linear inversion. Maps of the Moho depth, of the thickness of the lithosphere and of the shear-wave velocities, down to depths of 200 km and more, are constructed. A mantle wedge, identified in the uppermost mantle along the Apennines and the Calabrian Arc, underlies the principal recent volcanoes, and partial melting can be relevant in this part of the uppermost mantle. In Calabria a lithospheric doubling is seen, in connection with the subduction of the Ionian lithosphere. The asthenosphere is shallow in the Southern Tyrrhenian Sea. High velocity bodies, cutting the asthenosphere, outline the Adria-lonian subduction in the Tyrrhenian Sea and the deep-reaching lithospheric root in the Western Alps. Less deep lithospheric roots are seen in the Central Apennines. The lithosphere-asthenosphere properties delineat...

  7. The lithosphere-asthenosphere: Italy and surroundings

    Institute of Scientific and Technical Information of China (English)

    GiulianoF.Panza; AntonellaPontevivo; GiordanoChimera; RenetaRaykova; AbdelkrimAoudia

    2003-01-01

    The velocity-depth distribution of the lithosphere-asthenosphere in the Italian region and surroundings is imaged, with a lateral resolution of about 100 km, by sur-face wave velocity tomography and non-linear inversion.Maps of the Moho depth, of the thickness of the lithos-phere and of the shear-wave velocities, down to depths of 200 km and more, are constructed. A mantle wedge, iden-tified in the uppermost mantle along the Apennines and the Calabrian Arc, underlies the prmctpat recent votca-noes, and partial melting can be relevant in this part of the uppermost mantle. In Calabria, a lithospheric dou-bling is seen, in connection with the subduction of the Ionian lithosphere. The asthenosphere is shallow in the Southern Tyrrhenian Sea. High velocity bodies, cutting the asthenosphere, outline the Adria-lonian subduction in the Tyrrhenian Sea and the deep-reaching lithospheric root in the Western Alps. Less deep lithospheric roots are seen in the Central Apennines. The lithosphere-asthenos-phere properties delineate a differentiation between the northern and the southern sectors of the Adriatic Sea,likely attesting the fragmentation of Adria.

  8. Preliminary design of surrounding heliostat fields

    Energy Technology Data Exchange (ETDEWEB)

    Collado, Francisco J. [Zaragoza University, Dpto. de Ingenieria Mecanica, CPS-B, Maria de Luna 3, 50018 Zaragoza (Spain)

    2009-05-15

    Recently, the author has shown elsewhere a simplified model that allows quick evaluations of the annual overall energy collected by a surrounding heliostat field. This model is the combination of an analytical flux density function produced by a heliostat, developed by the own author, and an optimized mirror density distribution developed by University of Houston for the Solar One Project. As main conclusion of this previous work, it was recognized that such pseudo-continuous simplified model should not substitute much more accurate discrete evaluations, which manage thousands of individual heliostat coordinates. Here in this work, the difficulty of generating a preliminary discrete layout of a large number of heliostats is addressed. The main novelty is the direct definition of thousands of heliostat coordinates through basically two parameters i.e. a simplified blocking factor and an additional security distance. Such procedure, which was formerly theoretically suggested by the author, is put into practice here, showing examples and commenting their problems and advantages. Getting a previous set of thousands of heliostat coordinates would be a major first step in the complex process of designing solar power tower (SPT). (author)

  9. Fluid dynamics of dilatant fluid

    DEFF Research Database (Denmark)

    Nakanishi, Hiizu; Nagahiro, Shin-ichiro; Mitarai, Namiko

    2012-01-01

    A dense mixture of granules and liquid often shows a severe shear thickening and is called a dilatant fluid. We construct a fluid dynamics model for the dilatant fluid by introducing a phenomenological state variable for a local state of dispersed particles. With simple assumptions for an equation...... of the state variable, we demonstrate that the model can describe basic features of the dilatant fluid such as the stress-shear rate curve that represents discontinuous severe shear thickening, hysteresis upon changing shear rate, and instantaneous hardening upon external impact. An analysis of the model...... reveals that the shear thickening fluid shows an instability in a shear flow for some regime and exhibits the shear thickening oscillation (i.e., the oscillatory shear flow alternating between the thickened and the relaxed states). The results of numerical simulations are presented for one- and two...

  10. 链状分子状态方程的推导及热容的推算%New Perturbation Theory Model for Chain like Molecule Fluid and the Predicted Heat Capacity

    Institute of Scientific and Technical Information of China (English)

    梁世强; 张秉坚; 路映红; 胡文暄; 金之钧

    2001-01-01

    A model for the freely jointed square well chain fluid is developed based on the thermodynamic perturbation theory of Barker Henderson,Zhang and Wertheim.The analytic representations of square well monomer by Zhang are extended to obtain a series of representations for thermodynamic properties of square well chain fluids using the incorporating structural information for square well monomer of Wertheim's TPT1 model.The same work has been done using incorporating structural information for the diatomic square well fluid of TPT D model.The calculated results of compressibility factor,residual internal energy and constant volume heat capacity of 4 mer,8 mer and 16 mer chain fluids are tested against the MC results and a careful comparison between the model from TPT1 and that from TPT D has been made.The former agree with MC results much better than the later,especially for internal energy.To obtain the constant volume heat capacity,NVT MC simulations have been performed.%在 Barker Henderson, Zhang以及 Wertheim 等微扰理论的基础上 ,以方阱势硬球流体为参考体系 ,将 Zhang的解析表达方法与 Wertheim 的链成键自由能的处理方法结合起来 ,推导出自由链接的链状分子流体的 Helmholtz自由能的解析表达式 ,并得到了压缩因子、内能、恒容热容等热力学性质的计算式 .计算结果与 MC(Monte Carlo)模拟结果吻合良好 .对 Zhang的解析表达式与“ TPT D” (二阶 Wertheim微扰理论 )的结合也作了推导和计算 .

  11. Fluid dynamics

    CERN Document Server

    Bernard, Peter S

    2015-01-01

    This book presents a focused, readable account of the principal physical and mathematical ideas at the heart of fluid dynamics. Graduate students in engineering, applied math, and physics who are taking their first graduate course in fluids will find this book invaluable in providing the background in physics and mathematics necessary to pursue advanced study. The book includes a detailed derivation of the Navier-Stokes and energy equations, followed by many examples of their use in studying the dynamics of fluid flows. Modern tensor analysis is used to simplify the mathematical derivations, thus allowing a clearer view of the physics. Peter Bernard also covers the motivation behind many fundamental concepts such as Bernoulli's equation and the stream function. Many exercises are designed with a view toward using MATLAB or its equivalent to simplify and extend the analysis of fluid motion including developing flow simulations based on techniques described in the book.

  12. Impacts of Artificial Reefs on Surrounding Ecosystems

    Science.gov (United States)

    Manoukian, Sarine

    Artificial reefs are becoming a popular biological and management component in shallow water environments characterized by soft seabed, representing both important marine habitats and tools to manage coastal fisheries and resources. An artificial reef in the marine environment acts as an open system with exchange of material and energy, altering the physical and biological characteristics of the surrounding area. Reef stability will depend on the balance of scour, settlement, and burial resulting from ocean conditions over time. Because of the unstable nature of sediments, they require a detailed and systematic investigation. Acoustic systems like high-frequency multibeam sonar are efficient tools in monitoring the environmental evolution around artificial reefs, whereas water turbidity can limit visual dive and ROV inspections. A high-frequency multibeam echo sounder offers the potential of detecting fine-scale distribution of reef units, providing an unprecedented level of resolution, coverage, and spatial definition. How do artificial reefs change over time in relation to the coastal processes? How accurately does multibeam technology map different typologies of artificial modules of known size and shape? How do artificial reefs affect fish school behavior? What are the limitations of multibeam technology for investigating fish school distribution as well as spatial and temporal changes? This study addresses the above questions and presents results of a new approach for artificial reef seafloor mapping over time, based upon an integrated analysis of multibeam swath bathymetry data and geoscientific information (backscatter data analysis, SCUBA observations, physical oceanographic data, and previous findings on the geology and sedimentation processes, integrated with unpublished data) from Senigallia artificial reef, northwestern Adriatic Sea (Italy) and St. Petersburg Beach Reef, west-central Florida continental shelf. A new approach for observation of fish

  13. Properties of ultrathin cholesterol and phospholipid layers surrounding silicon-carbide nanotube: MD simulations.

    Science.gov (United States)

    Raczyński, Przemysław; Raczyńska, Violetta; Górny, Krzysztof; Gburski, Zygmunt

    2015-08-15

    Computer simulation technique was used to study the dynamics of cholesterol and POPC phospholipid molecules forming a thin layer on the surface of the carbon and silicon-carbide nanotubes. Each nanotube was surrounded by an ultra-thin film formed by n lipid molecules, where n varies from 15 to 50. All studies were done for five temperatures, including physiological one (T=260, 285, 310, 335 and 360K). The influence of a nanotube on the dynamics of cholesterol or phospholipid molecules in a layer is presented and discussed. The water is ubiquitous in all biological milieus, where the cholesterol or lipids occur. Thus, simulations were performed in a water environment. Moreover, to show different behavior of lipids in systems with water the results were compared with the samples without it. The dynamical and structural observables, such as the mean square displacement, diffusion coefficient, radial distribution function, and activation energy were calculated to qualitatively investigate the behavior of cholesterol and phospholipid molecules in the layers. We observed remarkable differences between the cholesterol dynamics depending whether the ultrathin film surrounds carbon or silicon-carbide nanotube and whether the water environment appeared. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. R fluids

    Directory of Open Access Journals (Sweden)

    Caimmi R.

    2008-01-01

    Full Text Available A theory of collisionless fluids is developed in a unified picture, where nonrotating (Ωf1 = Ωf2 = Ωf3 = 0 figures with some given random velocity component distributions, and rotating (Ωf1 = Ωf2 = Ωf3 figures with a different random velocity component distributions, make adjoint configurations to the same system. R fluids are defined as ideal, self-gravitating fluids satisfying the virial theorem assumptions, in presence of systematic rotation around each of the principal axes of inertia. To this aim, mean and rms angular velocities and mean and rms tangential velocity components are expressed, by weighting on the moment of inertia and the mass, respectively. The figure rotation is defined as the mean angular velocity, weighted on the moment of inertia, with respect to a selected axis. The generalized tensor virial equations (Caimmi and Marmo 2005 are formulated for R fluids and further attention is devoted to axisymmetric configurations where, for selected coordinate axes, a variation in figure rotation has to be counterbalanced by a variation in anisotropy excess and vice versa. A microscopical analysis of systematic and random motions is performed under a few general hypotheses, by reversing the sign of tangential or axial velocity components of an assigned fraction of particles, leaving the distribution function and other parameters unchanged (Meza 2002. The application of the reversion process to tangential velocity components is found to imply the conversion of random motion rotation kinetic energy into systematic motion rotation kinetic energy. The application of the reversion process to axial velocity components is found to imply the conversion of random motion translation kinetic energy into systematic motion translation kinetic energy, and the loss related to a change of reference frame is expressed in terms of systematic motion (imaginary rotation kinetic energy. A number of special situations are investigated in greater

  15. Cell membrane fluid-mosaic structure and cancer metastasis.

    Science.gov (United States)

    Nicolson, Garth L

    2015-04-01

    Cancer cells are surrounded by a fluid-mosaic membrane that provides a highly dynamic structural barrier with the microenvironment, communication filter and transport, receptor and enzyme platform. This structure forms because of the physical properties of its constituents, which can move laterally and selectively within the membrane plane and associate with similar or different constituents, forming specific, functional domains. Over the years, data have accumulated on the amounts, structures, and mobilities of membrane constituents after transformation and during progression and metastasis. More recent information has shown the importance of specialized membrane domains, such as lipid rafts, protein-lipid complexes, receptor complexes, invadopodia, and other cellular structures in the malignant process. In describing the macrostructure and dynamics of plasma membranes, membrane-associated cytoskeletal structures and extracellular matrix are also important, constraining the motion of membrane components and acting as traction points for cell motility. These associations may be altered in malignant cells, and probably also in surrounding normal cells, promoting invasion and metastatic colonization. In addition, components can be released from cells as secretory molecules, enzymes, receptors, large macromolecular complexes, membrane vesicles, and exosomes that can modify the microenvironment, provide specific cross-talk, and facilitate invasion, survival, and growth of malignant cells.

  16. R Fluids

    Directory of Open Access Journals (Sweden)

    Caimmi, R.

    2008-06-01

    Full Text Available A theory of collisionless fluids is developed in a unified picture, where nonrotating $(widetilde{Omega_1}=widetilde{Omega_2}= widetilde{Omega_3}=0$ figures with some given random velocity component distributions, and rotating $(widetilde{Omega_1} ewidetilde{Omega_2} e widetilde{Omega_3} $ figures with a different random velocity component distributions, make adjoint configurations to the same system. R fluids are defined as ideal, self-gravitating fluids satisfying the virial theorem assumptions, in presence of systematic rotation around each of the principal axes of inertia. To this aim, mean and rms angular velocities and mean and rms tangential velocity components are expressed, by weighting on the moment of inertia and the mass, respectively. The figure rotation is defined as the mean angular velocity, weighted on the moment of inertia, with respectto a selected axis. The generalized tensor virial equations (Caimmi and Marmo 2005 are formulated for R fluidsand further attention is devoted to axisymmetric configurations where, for selected coordinateaxes, a variation in figure rotation has to be counterbalanced by a variation in anisotropy excess and viceversa. A microscopical analysis of systematic and random motions is performed under a fewgeneral hypotheses, by reversing the sign of tangential or axial velocity components of anassigned fraction of particles, leaving the distribution function and other parametersunchanged (Meza 2002. The application of the reversion process to tangential velocitycomponents is found to imply the conversion of random motion rotation kinetic energy intosystematic motion rotation kinetic energy. The application ofthe reversion process to axial velocity components is found to imply the conversionof random motion translation kinetic energy into systematic motion translation kinetic energy, and theloss related to a change of reference frame is expressed in terms of systematic motion (imaginary rotation kinetic

  17. Fluid Shifts

    Science.gov (United States)

    Stenger, M. B.; Hargens, A. R.; Dulchavsky, S. A.; Arbeille, P.; Danielson, R. W.; Ebert, D. J.; Garcia, K. M.; Johnston, S. L.; Laurie, S. S.; Lee, S. M. C.; Liu, J.; Macias, B.; Martin, D. S.; Minkoff, L.; Ploutz-Snyder, R.; Ribeiro, L. C.; Sargsyan, A.; Smith, S. M.

    2017-01-01

    Introduction. NASA's Human Research Program is focused on addressing health risks associated with long-duration missions on the International Space Station (ISS) and future exploration-class missions beyond low Earth orbit. Visual acuity changes observed after short-duration missions were largely transient, but now more than 50 percent of ISS astronauts have experienced more profound, chronic changes with objective structural findings such as optic disc edema, globe flattening and choroidal folds. These structural and functional changes are referred to as the visual impairment and intracranial pressure (VIIP) syndrome. Development of VIIP symptoms may be related to elevated intracranial pressure (ICP) secondary to spaceflight-induced cephalad fluid shifts, but this hypothesis has not been tested. The purpose of this study is to characterize fluid distribution and compartmentalization associated with long-duration spaceflight and to determine if a relation exists with vision changes and other elements of the VIIP syndrome. We also seek to determine whether the magnitude of fluid shifts during spaceflight, as well as any VIIP-related effects of those shifts, are predicted by the crewmember's pre-flight status and responses to acute hemodynamic manipulations, specifically posture changes and lower body negative pressure. Methods. We will examine a variety of physiologic variables in 10 long-duration ISS crewmembers using the test conditions and timeline presented in the figure below. Measures include: (1) fluid compartmentalization (total body water by D2O, extracellular fluid by NaBr, intracellular fluid by calculation, plasma volume by CO rebreathe, interstitial fluid by calculation); (2) forehead/eyelids, tibia, and calcaneus tissue thickness (by ultrasound); (3) vascular dimensions by ultrasound (jugular veins, cerebral and carotid arteries, vertebral arteries and veins, portal vein); (4) vascular dynamics by MRI (head/neck blood flow, cerebrospinal fluid

  18. Yield stress fluids slowly yield to analysis

    NARCIS (Netherlands)

    Bonn, D.; Denn, M.M.

    2009-01-01

    We are surrounded in everyday life by yield stress fluids: materials that behave as solids under small stresses but flow like liquids beyond a critical stress. For example, paint must flow under the brush, but remain fixed in a vertical film despite the force of gravity. Food products (such as mayon

  19. Thermomolecular orientation of nonpolar fluids.

    Science.gov (United States)

    Römer, Frank; Bresme, Fernando; Muscatello, Jordan; Bedeaux, Dick; Rubí, J Miguel

    2012-03-09

    We investigate the response of molecular fluids to temperature gradients. Using nonequilibrium molecular dynamics computer simulations we show that nonpolar diatomic fluids adopt a preferred orientation as a response to a temperature gradient. We find that the magnitude of this thermomolecular orientation effect is proportional to the strength of the temperature gradient and the degree of molecular anisotropy, as defined by the different size or mass of the molecular atomic sites. We show that the preferred orientation of the molecules follows the same trends observed in the Soret effect of binary mixtures. We argue this is a general effect that should be observed in a wide range of length scales.

  20. Fluid dynamics

    CERN Document Server

    Ruban, Anatoly I

    This is the first book in a four-part series designed to give a comprehensive and coherent description of Fluid Dynamics, starting with chapters on classical theory suitable for an introductory undergraduate lecture course, and then progressing through more advanced material up to the level of modern research in the field. The present Part 1 consists of four chapters. Chapter 1 begins with a discussion of Continuum Hypothesis, which is followed by an introduction to macroscopic functions, the velocity vector, pressure, density, and enthalpy. We then analyse the forces acting inside a fluid, and deduce the Navier-Stokes equations for incompressible and compressible fluids in Cartesian and curvilinear coordinates. In Chapter 2 we study the properties of a number of flows that are presented by the so-called exact solutions of the Navier-Stokes equations, including the Couette flow between two parallel plates, Hagen-Poiseuille flow through a pipe, and Karman flow above an infinite rotating disk. Chapter 3 is d...

  1. THE CLASSIFICATION OF THE SURROUNDINGS OF COAL MINING ROADWAYS

    Institute of Scientific and Technical Information of China (English)

    邹喜正; 侯朝炯; 李华祥

    1996-01-01

    This introduces the calculation of opaper the deformationg .the Surroundings of coaowaysand the divisi of surroundings into 5 levels by means or !fuzzy integral assess mairrx, wnlcnserves-asthe scientific basis for selecting supporting pattern of roadways and determining the, pa-rameters of support.

  2. Expression of myeloperoxidase, soluble intercellular adhesion molecule-1 and pentraxin-3 in the gingival crevicular fluid during maxillary canine distal movement%上颌尖牙远中移动过程中龈沟液内中性粒细胞浸润炎症相关因子的表达

    Institute of Scientific and Technical Information of China (English)

    许桓溪; 邢洪波; 苗芳; 李宁; 邱静怡; 李娟

    2016-01-01

    BACKGROUND:To dynamicaly monitor the varying levels of inflammatory factors in the gingival crevicular fluid is helpful to assess the early effect of orthodontic tooth movement. Myeloperoxidase, soluble intercelular adhesion molecule-1, pentraxin 3 are proven to be closely related to inflammation, but it is unclear about the levels of these three kinds of inflammatory factors as wel as association of these three kinds of inflammatory factors with orthodontic tooth. OBJECTIVE:To detect the expression levels of myeloperoxidase, soluble intercelular adhesion molecule-1 and pentraxin-3 in the gingival crevicular fluid during maxilary canine distal movement and to assess their correlation with periodontal disease, canine movement distance and orthodontic force. METHODS:Twenty-one orthodontic patients were enroled and assigned into 150 g (n=12) or 100 g (n=9) groups according to orthodontic force. The gingival crevicular fluid samples of orthodontic patients were colected before and at 4, 12, 24 hours, 7, 14 days after maxilary canine distal movement. Levels of myeloperoxidase, soluble intercelular adhesion molecule-1 and pentraxin-3 in the gingival crevicular fluid were measured and analyzed using ELISA assay. RESULTS AND CONCLUSION: During the distal movement of maxilary canine, under orthodontic force, the level of myeloperoxidase was peaked at 4 hours and then decreased, while the expression level of soluble intercelular adhesion molecule-1 was peaked at 12 hours, and then decreased. Both myeloperoxidase and soluble intercelular adhesion molecule-1 levels returned to normal at 7 days under orthodontic force. The expression level of pentraxin-3 was increased significantly under orthodontic force, peaked at 24 hours, and then decreased gradualy to the normal level at 7 days. In addition, the expression levels of myeloperoxidase, soluble intercelular adhesion molecule-1 and pentraxin-3 in the gingival crevicular fluid were significantly higher under 150 g force than

  3. Oxy-combustor operable with supercritical fluid

    Energy Technology Data Exchange (ETDEWEB)

    Brun, Klaus; McClung, Aaron M.; Owston, Rebecca A.

    2017-04-04

    An oxy-combustor is provided which comprises a combustion vessel including at least one solid fuel slurry inlet port, at least one oxygen inlet port and at least one supercritical fluid inlet port, wherein the combustion vessel is operable at an operating pressure of at least 1,100 psi; an interior of the combustion vessel comprises a combustion chamber and a supercritical fluid infusion chamber surrounding at least a part of the combustion chamber, the supercritical fluid infusion chamber and the combustion chamber are separated by a porous liner surrounding the combustion chamber, and the supercritical infusion chamber is located between the porous liner and an outer casing of the combustion vessel.

  4. Pleural Fluid Analysis Test

    Science.gov (United States)

    ... Home Visit Global Sites Search Help? Pleural Fluid Analysis Share this page: Was this page helpful? Formal name: Pleural Fluid Analysis Related tests: Pericardial Fluid Analysis , Peritoneal Fluid Analysis , ...

  5. Surround suppression and sparse coding in visual and barrel cortices

    Directory of Open Access Journals (Sweden)

    Robert N S Sachdev

    2012-07-01

    Full Text Available During natural vision the entire retina is stimulated. Likewise, during natural tactile behaviors, spatially extensive regions of the somatosensory surface are co-activated. The large spatial extent of naturalistic stimulation means that surround suppression, a phenomenon whose neural mechanisms remain a matter of debate, must arise during natural behavior. To identify common neural motifs that might instantiate surround suppression across modalities, we review models of surround suppression and compare the evidence supporting the competing ideas that surround suppression has either cortical or sub-cortical origins in visual and barrel cortex. In the visual system there is general agreement lateral inhibitory mechanisms contribute to surround suppression, but little direct experimental evidence that intracortical inhibition plays a major role. Two intracellular recording studies of V1, one using naturalistic stimuli (Haider et al., 2010, the other sinusoidal gratings (Ozeki et al., 2009, sought to identify the causes of reduced activity in V1 with increasing stimulus size, a hallmark of surround suppression. The former attributed this effect to increased inhibition, the latter to largely balanced withdrawal of excitation and inhibition. In rodent primary somatosensory barrel cortex, multi-whisker responses are generally weaker than single whisker responses, suggesting multi-whisker stimulation engages similar surround suppressive mechanisms. The origins of suppression in S1 remain elusive: studies have implicated brainstem lateral/internuclear interactions and both thalamic and cortical inhibition. Although the anatomical organization and instantiation of surround suppression in the visual and somatosensory systems differ, we consider the idea that one common function of surround suppression, in both modalities, is to remove the statistical redundancies associated with natural stimuli by increasing the sparseness or selectivity of sensory

  6. Observational astrochemistry: The quest for interstellar molecules

    Directory of Open Access Journals (Sweden)

    Guélin M.

    2012-01-01

    Full Text Available Over 160 molecular species, not counting isotopologues, have been identified in circumstellar envelopes and interstellar clouds. These species have revealed a wealth of familiar, as much as exotic molecules and in complex organic (and silicon compounds, that was fully unexpected in view of the harshness of surrounding conditions: vanishingly low densities, extreme temperatures and intense embedding UV radiation. They illustrate the diversity of astrochemistry and show robust prebiotic molecules may be. In this lecture, we review the quest for interstellar molecules and show how tributary it is from theoretical ideas and technology developments. A. A. Penzias, who discovered interstellar CO and the 2.7 K Cosmic Background radiation, used to joke that astronomical research is easy: the great questions have largely been formulated; one only has to wait until technological progress makes it possible to answer.

  7. Extravasation of joint fluid into the mediastinum and the deep neck during atthoscopic shoulder surgery

    Energy Technology Data Exchange (ETDEWEB)

    Han, Ji Yeon; Lee, Ki Nam [Dept. of Radiology, Dong-A University Hospital, Dong-A University College of Medicine, Busan (Korea, Republic of)

    2014-01-15

    Extravasation of shoulder joint fluid into the surrounding muscles during shoulder arthroscopic surgery is common and inevitable. Here, we report a case of massive extravasation of shoulder joint fluid leading to mediastinal and retrotracheal effusion after arthroscopic shoulder surgery. We will discuss the anatomical basis of fluid leakage from the shoulder to the mediastinum and to the deep neck on CT.

  8. Fluid-structure interaction of three-dimensional magnetic artificial cilia

    NARCIS (Netherlands)

    Khaderi, S. N.; Onck, P. R.

    2012-01-01

    A numerical model is developed to analyse the interaction of artificial cilia with the surrounding fluid in a three-dimensional setting in the limit of vanishing fluid inertia forces. The cilia are modelled using finite shell elements and the fluid is modelled using a boundary element approach. The

  9. Surrounding Moving Obstacle Detection for Autonomous Driving Using Stereo Vision

    Directory of Open Access Journals (Sweden)

    Hao Sun

    2013-06-01

    Full Text Available Detection and tracking surrounding moving obstacles such as vehicles and pedestrians are crucial for the safety of mobile robotics and autonomous vehicles. This is especially the case in urban driving scenarios. This paper presents a novel framework for surrounding moving obstacles detection using binocular stereo vision. The contributions of our work are threefold. Firstly, a multiview feature matching scheme is presented for simultaneous stereo correspondence and motion correspondence searching. Secondly, the multiview geometry constraint derived from the relative camera positions in pairs of consecutive stereo views is exploited for surrounding moving obstacles detection. Thirdly, an adaptive particle filter is proposed for tracking of multiple moving obstacles in surrounding areas. Experimental results from real‐world driving sequences demonstrate the effectiveness and robustness of the proposed framework.

  10. Surrounding Moving Obstacle Detection for Autonomous Driving Using Stereo Vision

    Directory of Open Access Journals (Sweden)

    Hao Sun

    2013-06-01

    Full Text Available Detection and tracking surrounding moving obstacles such as vehicles and pedestrians are crucial for the safety of mobile robotics and autonomous vehicles. This is especially the case in urban driving scenarios. This paper presents a novel framework for surrounding moving obstacles detection using binocular stereo vision. The contributions of our work are threefold. Firstly, a multiview feature matching scheme is presented for simultaneous stereo correspondence and motion correspondence searching. Secondly, the multiview geometry constraint derived from the relative camera positions in pairs of consecutive stereo views is exploited for surrounding moving obstacles detection. Thirdly, an adaptive particle filter is proposed for tracking of multiple moving obstacles in surrounding areas. Experimental results from real-world driving sequences demonstrate the effectiveness and robustness of the proposed framework.

  11. Traditional Indian custOInS surrounding birth

    African Journals Online (AJOL)

    traditional custOIns surrounding birth in Indian culture. ... conception, pregnancy, birth and the early months ofparenthood. .... house attended by a traditional birth attendant of a ..... Spiritual components play a dominant role in traditional.

  12. Glow phenomenon surrounding the vertical stabilizer and OMS pods

    Science.gov (United States)

    1994-01-01

    This 35mm frame, photographed as the Space Shuttle Columbia was orbiting Earth during a 'night' pass, documents the glow phenomenon surrounding the vertical stabilizer and the Orbital Maneuvering System (OMS) pods of the spacecraft.

  13. Surrounding Moving Obstacle Detection for Autonomous Driving Using Stereo Vision

    OpenAIRE

    Hao Sun; Huanxin Zou; Shilin Zhou; Cheng Wang; Naser El-Sheimy

    2013-01-01

    Detection and tracking surrounding moving obstacles such as vehicles and pedestrians are crucial for the safety of mobile robotics and autonomous vehicles. This is especially the case in urban driving scenarios. This paper presents a novel framework for surrounding moving obstacles detection using binocular stereo vision. The contributions of our work are threefold. Firstly, a multiview feature matching scheme is presented for simultaneous stereo correspondence and motion correspondence searc...

  14. Interaction between SCO-spondin and low density lipoproteins from embryonic cerebrospinal fluid modulates their roles in early neurogenesis

    Directory of Open Access Journals (Sweden)

    América eVera

    2015-05-01

    Full Text Available During early stages of development, encephalic vesicles are composed by a layer of neuroepithelial cells surrounding a central cavity filled with embryonic cerebrospinal fluid (eCSF. This fluid contains several morphogens that regulate proliferation and differentiation of neuroepithelial cells. One of these neurogenic factors is SCO-spondin, a giant protein secreted to the eCSF from early stages of development. Inhibition of this protein in vivo or in vitro drastically decreases the neurodifferentiation process. Other important neurogenic factors of the eCSF are low density lipoproteins (LDL, the depletion of which generates a 60% decrease in mesencephalic explant neurodifferentiation. The presence of several LDL receptor class A (LDLrA domains (responsible for LDL binding in other proteins in the SCO-spondin sequence suggests a possible interaction between both molecules. This possibility was analyzed using three different experimental approaches: 1 Bioinformatics analyses of the SCO-spondin region, that contains eight LDLrA domains in tandem, and of comparisons with the LDL receptor consensus sequence; 2 Analysis of the physical interactions of both molecules through immunohistochemical colocalization in embryonic chick brains and through the immunoprecipitation of LDL with anti-SCO-spondin antibodies; and 3 Analysis of functional interactions during the neurodifferentiation process when these molecules were added to a culture medium of mesencephalic explants. The results revealed that LDL and SCO-spondin interact to form a complex that diminishes the neurogenic capacities that both molecules have separately. Our work suggests that the embryonic cerebrospinal fluid is an active signaling center with a complex regulation system that allows for correct brain development.

  15. "Tilt" in color space: Hue changes induced by chromatic surrounds.

    Science.gov (United States)

    Klauke, Susanne; Wachtler, Thomas

    2015-01-01

    The perceived color of a chromatic stimulus is influenced by the chromaticity of its surround. To investigate these influences along the dimension of hue, we measured hue changes induced in stimuli of different hues by isoluminant chromatic surrounds. Generally, induced hue changes were directed in color space away from the hue of the inducing surround and depended on the magnitude on the hue difference between stimulus and surround. With increasing difference in hue between stimulus and surround, induced hue changes increased up to a maximum and then decreased for larger differences. This qualitative pattern was similar for different inducers, but quantitatively, induction was weaker along some directions in cone-opponent color space than along other directions. The strongest induction effects were found along an oblique, blue-yellow axis that corresponds to the daylight axis. The overall pattern of the induction effect shows similarities to the well-known tilt effect, where shifts in perceived angle of oriented stimuli are induced by oriented surrounds. This suggests analogous neural representations and similar mechanisms of contextual processing for different visual features such as orientation and color.

  16. Control of Formation of Lithological Reservoirs by Surrounding Mudstone

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Taking the Jiyang depression as an example, this paper discusses the control of the formation of lithological reservoir by surrounding rocks by integrated application of geological analysis, physical simulation, and the analysis of oil & gas accumulation mechanism. Geological statistical shows that the major burial depth and interval of lithological reservoirs in the Jiyang depression are related to the hydrocarbon generation in and expulsion from the Lower Tertiary source rocks and the time of the formation of most lithological reservoirs coincides with the peak of hydrocarbon generation and expulsion. The lithological traps located in the center of effective source rocks are propitious to high oil saturation than those located on the margin of effective source rocks. The hydrocarbon charge degree of the lithological reservoir has a positive correlation with the intensity of hydrocarbon expulsion from surrounding source rocks.Geological analyses and NMR experiments also show that the oil saturation of surrounding source rocks control the hydrocarbon potential of lithological traps, and a critical value for oil saturation of surrounding mudstone is required, that is, when the oil saturation of surrounding mudstone is lower than this critical value, no oil and gas accumulate in the lithological trap. The control of surrounding mudstone on the oil-bearing properties of lithological reservoirs is also analyzed by the mechanisms of hydrocarbon generation and expulsion as well as accumulation.

  17. Formation of Ultracold Molecules

    Energy Technology Data Exchange (ETDEWEB)

    Cote, Robin [Univ. of Connecticut, Storrs, CT (United States)

    2016-01-28

    Advances in our ability to slow down and cool atoms and molecules to ultracold temperatures have paved the way to a revolution in basic research on molecules. Ultracold molecules are sensitive of very weak interactions, even when separated by large distances, which allow studies of the effect of those interactions on the behavior of molecules. In this program, we have explored ways to form ultracold molecules starting from pairs of atoms that have already reached the ultracold regime. We devised methods that enhance the efficiency of ultracold molecule production, for example by tuning external magnetic fields and using appropriate laser excitations. We also investigates the properties of those ultracold molecules, especially their de-excitation into stable molecules. We studied the possibility of creating new classes of ultra-long range molecules, named macrodimers, thousand times more extended than regular molecules. Again, such objects are possible because ultra low temperatures prevent their breakup by collision. Finally, we carried out calculations on how chemical reactions are affected and modified at ultracold temperatures. Normally, reactions become less effective as the temperature decreases, but at ultracold temperatures, they can become very effective. We studied this counter-intuitive behavior for benchmark chemical reactions involving molecular hydrogen.

  18. Separation of supercritical slab-fluids to form aqueous fluid and melt components in subduction zone magmatism

    Science.gov (United States)

    Kawamoto, Tatsuhiko; Kanzaki, Masami; Mibe, Kenji; Ono, Shigeaki

    2012-01-01

    Subduction-zone magmatism is triggered by the addition of H2O-rich slab-derived components: aqueous fluid, hydrous partial melts, or supercritical fluids from the subducting slab. Geochemical analyses of island arc basalts suggest two slab-derived signatures of a melt and a fluid. These two liquids unite to a supercritical fluid under pressure and temperature conditions beyond a critical endpoint. We ascertain critical endpoints between aqueous fluids and sediment or high-Mg andesite (HMA) melts located, respectively, at 83-km and 92-km depths by using an in situ observation technique. These depths are within the mantle wedge underlying volcanic fronts, which are formed 90 to 200 km above subducting slabs. These data suggest that sediment-derived supercritical fluids, which are fed to the mantle wedge from the subducting slab, react with mantle peridotite to form HMA supercritical fluids. Such HMA supercritical fluids separate into aqueous fluids and HMA melts at 92 km depth during ascent. The aqueous fluids are fluxed into the asthenospheric mantle to form arc basalts, which are locally associated with HMAs in hot subduction zones. The separated HMA melts retain their composition in limited equilibrium with the surrounding mantle. Alternatively, they equilibrate with the surrounding mantle and change the major element chemistry to basaltic composition. However, trace element signatures of sediment-derived supercritical fluids remain more in the melt-derived magma than in the fluid-induced magma, which inherits only fluid-mobile elements from the sediment-derived supercritical fluids. Separation of slab-derived supercritical fluids into melts and aqueous fluids can elucidate the two slab-derived components observed in subduction zone magma chemistry. PMID:23112158

  19. Separation of supercritical slab-fluids to form aqueous fluid and melt components in subduction zone magmatism.

    Science.gov (United States)

    Kawamoto, Tatsuhiko; Kanzaki, Masami; Mibe, Kenji; Matsukage, Kyoko N; Ono, Shigeaki

    2012-11-13

    Subduction-zone magmatism is triggered by the addition of H(2)O-rich slab-derived components: aqueous fluid, hydrous partial melts, or supercritical fluids from the subducting slab. Geochemical analyses of island arc basalts suggest two slab-derived signatures of a melt and a fluid. These two liquids unite to a supercritical fluid under pressure and temperature conditions beyond a critical endpoint. We ascertain critical endpoints between aqueous fluids and sediment or high-Mg andesite (HMA) melts located, respectively, at 83-km and 92-km depths by using an in situ observation technique. These depths are within the mantle wedge underlying volcanic fronts, which are formed 90 to 200 km above subducting slabs. These data suggest that sediment-derived supercritical fluids, which are fed to the mantle wedge from the subducting slab, react with mantle peridotite to form HMA supercritical fluids. Such HMA supercritical fluids separate into aqueous fluids and HMA melts at 92 km depth during ascent. The aqueous fluids are fluxed into the asthenospheric mantle to form arc basalts, which are locally associated with HMAs in hot subduction zones. The separated HMA melts retain their composition in limited equilibrium with the surrounding mantle. Alternatively, they equilibrate with the surrounding mantle and change the major element chemistry to basaltic composition. However, trace element signatures of sediment-derived supercritical fluids remain more in the melt-derived magma than in the fluid-induced magma, which inherits only fluid-mobile elements from the sediment-derived supercritical fluids. Separation of slab-derived supercritical fluids into melts and aqueous fluids can elucidate the two slab-derived components observed in subduction zone magma chemistry.

  20. Carbon Dioxide: The Other Planetary Fluid

    Science.gov (United States)

    Glaser, S.; Gamez, D.; Shock, E.

    2016-12-01

    Cometary and interstellar ices have carbon dioxide to water mole ratios of up to 0.3. When melted, such high levels of carbon dioxide cannot all be dissolved in the aqueous phase and instead partition into a CO2-rich (carbonic) fluid. This implies that during the accretion and formation of planetary systems carbonic fluids are not only possible, but common. In fact, they make up the atmosphere of Venus, are found bubbling out of Champagne Vent in the Pacific Ocean, and are documented by metamorphic fluid inclusions. Examination of phase diagrams reveals the conditions where carbonic fluids will exist or predominate. Carbonic fluids are predicted to exist in Earth's subduction zones and under the ice of small ocean worlds. CO2 had previously been shown to completely dissolve into NH­­3­-H­­2O oceans on small icy bodies by forming ammonium carbonate, but the newer measurements of CO2­ abundances indicate that not all of the CO2 can partition into the aqueous fluid as ammonium carbonate. The remaining CO2 would necessarily form a separate carbonic fluid making it likely that liquid CO2 would be a major oceanic component on some small icy bodies. The enhanced solubility of nonpolar and slightly polar organic compounds in carbonic fluids relative to aqueous fluids means that generation, transport, and deposition processes can be greatly enhanced in those cases where carbonic fluids occur. As an example, the solubility of benzoic acid, a polar compound, is about an order of magnitude greater in carbonic than in aqueous fluids, which is surprising given that water is a polar solvent and carbon dioxide is a nonpolar solvent. Anthracene, a nonpolar compound, has an even greater solubility difference between carbonic and aqueous fluids at approximately four orders of magnitude. Highly polar compounds, including most of the building blocks of life, are more soluble in aqueous fluids than in carbonic fluids. The solubility difference of organic molecules in carbonic

  1. Theoretical Investigation of the Optical Spectra of Organic Compounds in Natural Surrounding

    Science.gov (United States)

    Pomogaev, V. A.; Artyukhov, V. Ya.

    2016-08-01

    The hybrid multiscale approximation based on molecular dynamics, quantum mechanics, and statistical theory is used to generate profiles of electronic vibrational absorption and fluorescence bands of some organic compounds and biological objects whose photophysical properties specifically depend on external conditions. A temperature dependence of the spectrum width and intensity of transition to the long-wavelength band of benzene surrounded by cyclohexane molecules is demonstrated. Statistical broadband absorption spectra for estradiol in ethanol, hexane, and dimethyl sulfoxide have been obtained and analyzed at room temperature together with a wide spectrum of transitions to numerous excited states of Trp-cage miniprotein. The absorption and emission spectra of 9-cyan anthracene have been generated under various thermodynamic conditions. This allows changes in the spectral profile with increasing temperatures and pressure to be detected. A dependence of the tryptophan spectra on the protein microsurrounding is investigated. The possibility of charge transfer from tryptophan residue to the eupatorin molecule trapped by human serum albumin is analyzed. Spectral properties and charge transfer from the excited donor to acceptor states are calculated using the polarizable embedding approach for modeling of surrounding protein structure.

  2. Failure mechanism of Mesozoic soft rock roadway in Shajihai coal mine and its surrounding rock control

    Institute of Scientific and Technical Information of China (English)

    Yuan Yue; Zhu Yongjian; Wang Weijun; Yu Weijian

    2014-01-01

    In view of the buckling failure caused by large deformation of Mesozoic soft rock roadway in Shajihai mining area, such as serious roof fall, rib spalling, floor heave, etc., based on the detail site investigation, theoretical analysis, mineral composition test, microstructure test, water-physical property test and field experiments were carried out. And we revealed the compound failure mechanism of Mesozoic soft rock roadway in Shajihai mining area, namely the molecule expansion-shear slip of weak structural plane-construction disturbance. On this basis, the coupling support technology whose core is constant resistance with large deformation bolt was proposed. The feature of this supporting technology is that a new type of structural composite material was used, which makes the supporting system not only has the ideal deformation characteristics, but also has high supporting resistance. Thus the fully release of plastic energy within surrounding rock and reasonable control of the thickness of the plastic ring were realized. Then the differential deformation between the surrounding rock and support was eliminated by the secondary coupling support of bolt–mesh–cable, and the bolt with high strength was applied in the base angle to control floor. Eventually the collaborative bearing system of surrounding rock–support was formed. Through field tests the validity and rationality of support was also verified.

  3. Forest Fragments Surrounded by Sugar Cane Are More Inhospitable to Terrestrial Amphibian Abundance Than Fragments Surrounded by Pasture

    Directory of Open Access Journals (Sweden)

    Paula Eveline Ribeiro D’Anunciação

    2013-01-01

    Full Text Available In recent years, there has been increasing interest in matrix-type influence on forest fragments. Terrestrial amphibians are good bioindicators for this kind of research because of low vagility and high philopatry. This study compared richness, abundance, and species composition of terrestrial amphibians through pitfall traps in two sets of semideciduous seasonal forest fragments in southeastern Brazil, according to the predominant surrounding matrix (sugar cane and pasture. There were no differences in richness, but fragments surrounded by sugar cane had the lowest abundance of amphibians, whereas fragments surrounded by pastures had greater abundance. The most abundant species, Rhinella ornata, showed no biometric differences between fragment groups but like many other amphibians sampled showed very low numbers of individuals in fragments dominated by sugar cane fields. Our data indicate that the sugar cane matrix negatively influences the community of amphibians present in fragments surrounded by this type of land use.

  4. Filming the Birth of Molecules and Accompanying Solvent Rearrangement

    DEFF Research Database (Denmark)

    Lee, Jae Hyuk; Wulff, Michael; Bratos, Savo;

    2013-01-01

    Molecules are often born with high energy and large-amplitude vibrations. In solution, a newly formed molecule cools down by transferring energy to the surrounding solvent molecules. The progression of the molecular and solute−solvent cage structure during this fundamental process has been elusive......, and spectroscopic data generally do not provide such structural information. Here, we use picosecond X-ray liquidography (solution scattering) to visualize timedependent structural changes associated with the vibrational relaxation of I2 molecules in two different solvents, CCl4 and cyclohexane. The birth...... and vibrational relaxation of I2 molecules and the associated rearrangement of solvent molecules are mapped out in the form of a temporally varying interatomic distance distribution. The I−I distance increases up to ∼4 Å and returns to the equilibrium distance (2.67 Å) in the ground state, and the first solvation...

  5. [Endothelial cell adhesion molecules].

    Science.gov (United States)

    Ivanov, A N; Norkin, I A; Puchin'ian, D M; Shirokov, V Iu; Zhdanova, O Iu

    2014-01-01

    The review presents current data concerning the functional role of endothelial cell adhesion molecules belonging to different structural families: integrins, selectins, cadherins, and the immunoglobulin super-family. In this manuscript the regulatory mechanisms and factors of adhesion molecules expression and distribution on the surface of endothelial cells are discussed. The data presented reveal the importance of adhesion molecules in the regulation of structural and functional state of endothelial cells in normal conditions and in pathology. Particular attention is paid to the importance of these molecules in the processes of physiological and pathological angiogenesis, regulation of permeability of the endothelial barrier and cell transmigration.

  6. Trapping molecules on chips

    CERN Document Server

    Santambrogio, Gabriele

    2015-01-01

    In the last years, it was demonstrated that neutral molecules can be loaded on a microchip directly from a supersonic beam. The molecules are confined in microscopic traps that can be moved smoothly over the surface of the chip. Once the molecules are trapped, they can be decelerated to a standstill, for instance, or pumped into selected quantum states by laser light or microwaves. Molecules are detected on the chip by time-resolved spatial imaging, which allows for the study of the distribution in the phase space of the molecular ensemble.

  7. Thermophysical Properties of Fluids and Fluid Mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Sengers, Jan V.; Anisimov, Mikhail A.

    2004-05-03

    The major goal of the project was to study the effect of critical fluctuations on the thermophysical properties and phase behavior of fluids and fluid mixtures. Long-range fluctuations appear because of the presence of critical phase transitions. A global theory of critical fluctuations was developed and applied to represent thermodynamic properties and transport properties of molecular fluids and fluid mixtures. In the second phase of the project, the theory was extended to deal with critical fluctuations in complex fluids such as polymer solutions and electrolyte solutions. The theoretical predictions have been confirmed by computer simulations and by light-scattering experiments. Fluctuations in fluids in nonequilibrium states have also been investigated.

  8. Magnetic movement of biological fluid droplets

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Antonio A. [Harrington Department of Bioengineering, Arizona State University, Tempe, AZ 85287 (United States)]. E-mail: tony.garcia@asu.edu; Egatz-Gomez, Ana [Harrington Department of Bioengineering, Arizona State University, Tempe, AZ 85287 (United States); Lindsay, Solitaire A. [Harrington Department of Bioengineering, Arizona State University, Tempe, AZ 85287 (United States); Dominguez-Garcia, P. [Departamento de Fisica Fundamental, UNED, Senda del Rey 9, Madrid 28040 (Spain); Melle, Sonia [Harrington Department of Bioengineering, Arizona State University, Tempe, AZ 85287 (United States); Departamento de Optica, Universidad Complutense de Madrid, Arcos de Jalon s/n, Madrid 28037 (Spain); Marquez, Manuel [Harrington Department of Bioengineering, Arizona State University, Tempe, AZ 85287 (United States); Research Center, Philip Morris USA, Richmond, VA 23234 (United States); Rubio, Miguel A. [Departamento de Fisica Fundamental, UNED, Senda del Rey 9, Madrid 28040 (Spain); Picraux, S.T. [Department of Chemical and Materials Engineering, Arizona State University, Tempe, AZ 85287 (United States); Los Alamos National Laboratory, MST-CINT, Los Alamos, NM 87545 (United States); Yang, Dongqing [Department of Chemical and Materials Engineering, Arizona State University, Tempe, AZ 85287 (United States); Aella, P. [Department of Chemical and Materials Engineering, Arizona State University, Tempe, AZ 85287 (United States); Hayes, Mark A. [Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 8528 (United States); Gust, Devens [Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 8528 (United States); Loyprasert, Suchera [Biodesign Institute, Arizona State University, Tempe, AZ 85287 (United States); Vazquez-Alvarez, Terannie [Biodesign Institute, Arizona State University, Tempe, AZ 85287 (United States); Wang, Joseph [Biodesign Institute, Arizona State University, Tempe, AZ 85287 (United States)

    2007-04-15

    Magnetic fields can be used to control the movement of aqueous drops on non-patterned, silicon nanowire superhydrophobic surfaces. Drops of aqueous and biological fluids are controlled by introducing magnetizable carbonyl iron microparticles into the liquid. Key elements of operations such as movement, coalescence, and splitting of water and biological fluid drops, as well as electrochemical measurement of an analyte are demonstrated. Superhydrophobic surfaces were prepared using vapor-liquid-solid (VLS) growth systems followed by coating with a perfluorinated hydrocarbon molecule. Drops were made from aqueous and biological fluid suspensions with magnetizable microparticle concentrations ranging from 0.1 to 10 wt%.

  9. Migraine increases centre-surround suppression for drifting visual stimuli.

    Directory of Open Access Journals (Sweden)

    Josephine Battista

    Full Text Available BACKGROUND: The pathophysiology of migraine is incompletely understood, but evidence points to hyper-responsivity of cortical neurons being a key feature. The basis of hyper-responsiveness is not clear, with an excitability imbalance potentially arising from either reduced inhibition or increased excitation. In this study, we measure centre-surround contrast suppression in people with migraine as a perceptual analogue of the interplay between inhibition and excitation in cortical areas responsible for vision. We predicted that reduced inhibitory function in migraine would reduce perceptual surround suppression. Recent models of neuronal surround suppression incorporate excitatory feedback that drives surround inhibition. Consequently, an increase in excitation predicts an increase in perceptual surround suppression. METHODS AND FINDINGS: Twenty-six people with migraine and twenty approximately age- and gender-matched non-headache controls participated. The perceived contrast of a central sinusoidal grating patch (4 c/deg stationary grating, or 2 c/deg drifting at 2 deg/sec, 40% contrast was measured in the presence and absence of a 95% contrast annular grating (same orientation, spatial frequency, and drift rate. For the static grating, similar surround suppression strength was present in control and migraine groups with the presence of the surround resulting in the central patch appearing to be 72% and 65% of its true contrast for control and migraine groups respectively (t(44 = 0.81, p = 0.42. For the drifting stimulus, the migraine group showed significantly increased surround suppression (t(44 = 2.86, p<0.01, with perceived contrast being on average 53% of actual contrast for the migraine group and 68% for non-headache controls. CONCLUSIONS: In between migraines, when asymptomatic, visual surround suppression for drifting stimuli is greater in individuals with migraine than in controls. The data provides evidence for a

  10. Physics of Polymers under Nanoscopic Confinement: a Single Molecule Study

    NARCIS (Netherlands)

    Keshavarz, M.

    2016-01-01

    Physicist Masoumeh Keshavarz studied the thermal motion of a fluorescently labelled, individual “reporter” polymer molecule, surrounded and entangled by a gel of similar but unlabelled polymers. Owing to their extreme length and stiffness, it is possible to follow the shape and the motion of the rep

  11. Mud-filtrate correction of sonic logs by fluid substitution

    DEFF Research Database (Denmark)

    Sørensen, Morten Kanne

    . The pressure in the borehole is kept higher than in the surrounding formation to control fluid production from the borehole. The over pressure in the borehole drives fluid from the borehole into the formation, whereby a sonic log measures velocities at a different saturation than the formation saturation......, which the seismic data probes. For a proper well-tie sonic logs therefore require correction. Gassmann (1951) fluid substitution relates elastic velocities of a porous medium at one saturation to the elastic velocities at another saturation. Fluid substation can then predict a sonic log...... at the undisturbed formation saturation from the invaded saturation. Fluid substitution is exact for a uniform, high-permeable porous medium saturated by a single fluid. Rocks does not necessarily conform to these requirements, and both the formation saturation and invaded saturation involve two fluids. Sonic log...

  12. Modeling of Dynamic Fluid Forces in Fast Switching Valves

    DEFF Research Database (Denmark)

    Roemer, Daniel Beck; Johansen, Per; Pedersen, Henrik Clemmensen;

    2015-01-01

    Switching valves experience opposing fluid forces due to movement of the moving member itself, as the surrounding fluid volume must move to accommodate the movement. This movement-induced fluid force may be divided into three main components; the added mass term, the viscous term and the socalled...... history term. For general valve geometries there are no simple solution to either of these terms. During development and design of such switching valves, it is therefore, common practice to use simple models to describe the opposing fluid forces, neglecting all but the viscous term which is determined...... based on shearing areas and venting channels. For fast acting valves the opposing fluid force may retard the valve performance significantly, if appropriate measures are not taken during the valve design. Unsteady Computational Fluid Dynamics (CFD) simulations are available to simulate the total fluid...

  13. Algebraic theory of molecules

    CERN Document Server

    Iachello, F

    1995-01-01

    1. The Wave Mechanics of Diatomic Molecules. 2. Summary of Elements of Algebraic Theory. 3. Mechanics of Molecules. 4. Three-Body Algebraic Theory. 5. Four-Body Algebraic Theory. 6. Classical Limit and Coordinate Representation. 8. Prologue to the Future. Appendices. Properties of Lie Algebras; Coupling of Algebras; Hamiltonian Parameters

  14. ISOLATED MOLECULES IN METALS

    NARCIS (Netherlands)

    1992-01-01

    In this paper, some results obtained on the formation of isolated molecules of composition SnOx in silver and SnFx in copper-are reviewed. Hyperfine interaction and ion beam interaction techniques were used for the identification of these molecules.

  15. ISOLATED MOLECULES IN METALS

    NARCIS (Netherlands)

    1992-01-01

    In this paper, some results obtained on the formation of isolated molecules of composition SnOx in silver and SnFx in copper-are reviewed. Hyperfine interaction and ion beam interaction techniques were used for the identification of these molecules.

  16. Molecules in galaxies

    CERN Document Server

    Omont, Alain

    2007-01-01

    The main achievements, current developments and prospects of molecular studies in external galaxies are reviewed. They are put in the context of the results of several decades of studies of molecules in local interstellar medium, their chemistry and their importance for star formation. CO observations have revealed the gross structure of molecular gas in galaxies. Together with other molecules, they are among the best tracers of star formation at galactic scales. Our knowledge about molecular abundances in various local galactic environments is progressing. They trace physical conditions and metallicity, and they are closely related to dust processes and large aromatic molecules. Major recent developments include mega-masers, and molecules in Active Galactic Nuclei; millimetre emission of molecules at very high redshift; and infrared H2 emission as tracer of warm molecular gas, shocks and photodissociation regions. The advent of sensitive giant interferometers from the centimetre to sub-millimetre range, espe...

  17. 6.1 channel general planar surround sound system

    Institute of Scientific and Technical Information of China (English)

    XIE Bosun

    2001-01-01

    A new 6.1 channel surround sound system and its two signal mixing methods are proposed. Theoretical and experimental results show that the system is able to recreate 360°sound image in horizontal plane. Especially, compared with current 5.1 channel system, lateral and rear image of the new system is improved obviously. Therefore it is suitable to be used as a general surround sound system. It is also proved that, the new system is fully compatible with 5.1 channel system, and current methods are available to record 6.1 channel signals.

  18. Linking disadvantaged housing areas to the surrounding city

    DEFF Research Database (Denmark)

    Stender, Marie

    Several disadvantaged social housing areas in Denmark are currently undergo-ing thorough physical refurbishments, aiming to integrate them better with the surrounding city. The ambition is to attract new users and residents by opening up the borders of the area and establish attractive, new...... that especially eve-ryday-route strategies adding new public functions within the area can pave the way for integration with the surroundings. The applicability of such strategies is however highly dependent on the context, location and existing image of the ar-ea. Social distance may sustain though physical...

  19. Heat Dissipation from Suspended Carbon Nanotubes to their Surrounding Gas Environment

    Science.gov (United States)

    Hsu, I. Kai; Pettes, Michael T.; Aykol, Mehmet; Shi, Li; Cronin, Stephen

    2011-03-01

    The assistance of gas molecules to dissipate heat in 5- μ m-long, electrical heated suspended carbon nanotubes (CNTs) is observed by comparing the G band Raman phonon temperature profiles measured in different gas environments and in vacuum. The measurement results show that 50-60% of the heat generated in the CNT is carried away by its surrounding gas molecules. By analyzing the temperature profiles investigated in different gases, the thermal boundary conductance (TBC) between the gas molecules and the CNT can also be extracted. We find the TBC to be higher in carbon dioxide than in nitrogen, argon and helium. Moreover, we report another optical method to explore the heat spreading behavior on a longer suspended CNTs in air, in which one laser is used as a heat source while another laser is used as a local temperature probe. A fin-shape thermal transport model is applied to fit the exponentially decaying temperature profiles measured away from the heat source. These results yield a heat decay length and TBC for air to be around 6.5 μ m and 3 × 105 W/ m 2 K, respectively. I Kai Hsu et al. Journal of Applied Physics 2010, 108, (084307).

  20. Dynamics of Activated Molecules

    Energy Technology Data Exchange (ETDEWEB)

    Mullin, Amy S. [Univ. of Maryland, College Park, MD (United States)

    2016-11-16

    Experimental studies have been performed to investigate the collisional energy transfer processes of gas-phase molecules that contain large amounts of internal energy. Such molecules are prototypes for molecules under high temperature conditions relevant in combustion and information about their energy transfer mechanisms is needed for a detailed understanding and modeling of the chemistry. We use high resolution transient IR absorption spectroscopy to measure the full, nascent product distributions for collisions of small bath molecules that relax highly vibrationally excited pyrazine molecules with E=38000 cm-1 of vibrational energy. To perform these studies, we developed new instrumentation based on modern IR light sources to expand our experimental capabilities to investigate new molecules as collision partners. This final report describes our research in four areas: the characterization of a new transient absorption spectrometer and the results of state-resolved collision studies of pyrazine(E) with HCl, methane and ammonia. Through this research we have gained fundamental new insights into the microscopic details of relatively large complex molecules at high energy as they undergo quenching collisions and redistribute their energy.

  1. Ecological mechanisms linking protected areas to surrounding lands.

    Science.gov (United States)

    Hansen, Andrew J; DeFries, Ruth

    2007-06-01

    Land use is expanding and intensifying in the unprotected lands surrounding many of the world's protected areas. The influence of this land use change on ecological processes is poorly understood. The goal of this paper is to draw on ecological theory to provide a synthetic framework for understanding how land use change around protected areas may alter ecological processes and biodiversity within protected areas and to provide a basis for identifying scientifically based management alternatives. We first present a conceptual model of protected areas embedded within larger ecosystems that often include surrounding human land use. Drawing on case studies in this Invited Feature, we then explore a comprehensive set of ecological mechanisms by which land use on surrounding lands may influence ecological processes and biodiversity within reserves. These mechanisms involve changes in ecosystem size, with implications for minimum dynamic area, species-area effect, and trophic structure; altered flows of materials and disturbances into and out of reserves; effects on crucial habitats for seasonal and migration movements and population source/sink dynamics; and exposure to humans through hunting, poaching, exotics species, and disease. These ecological mechanisms provide a basis for assessing the vulnerability of protected areas to land use. They also suggest criteria for designing regional management to sustain protected areas in the context of surrounding human land use. These design criteria include maximizing the area of functional habitats, identifying and maintaining ecological process zones, maintaining key migration and source habitats, and managing human proximity and edge effects.

  2. Metrizamide demonstration of the subarachnoid space surrounding the Gasserian ganglion

    Energy Technology Data Exchange (ETDEWEB)

    Christmann, D.; Babin, E.

    1980-05-01

    The chance opacification of the subarachnoid space surrounding the Gasserian ganglion, observed during metrizamide basal cisternography, is reported. This is compared to similar demonstrations of the optic subarachnoid space. Such infrequently observed images should be known because they may be related to the occurrence of trigeminal neuralgia.

  3. Orientation-tuned surround suppression in mouse visual cortex

    NARCIS (Netherlands)

    Self, Matthew W; Lorteije, Jeannette A M; Vangeneugden, Joris; van Beest, Enny H; Grigore, Mihaela E; Levelt, Christiaan N; Heimel, J.A.; Roelfsema, Pieter R

    2014-01-01

    The firing rates of neurons in primary visual cortex (V1) are suppressed by large stimuli, an effect known as surround suppression. In cats and monkeys, the strength of suppression is sensitive to orientation; responses to regions containing uniform orientations are more suppressed than those contai

  4. Challenges Surrounding the Education of Children with Chronic Diseases

    Science.gov (United States)

    Gordon, Maria, Ed.

    2016-01-01

    While governing bodies have mandated that all students have the right to an education, with disabled students treated to the same rights and opportunities as non-disabled students, policymakers do not always agree on what all-inclusive education should look like. "Challenges Surrounding the Education of Children with Chronic Diseases"…

  5. Heavy Exotic Molecules

    CERN Document Server

    Liu, Yizhuang

    2016-01-01

    We briefly review the formation of pion-mediated heavy-light exotic molecules with both charm and bottom, under the general strictures of chiral and heavy quark symmetries. The charm isosinglet exotic molecules with $J^{PC}=1^{++}$ binds, which we identify as the reported neutral $X(3872)$. The bottom isotriplet exotic with $J^{PC}=1^{+-}$ binds, and is identified as a mixed state of the reported charged exotics $Z^+_b(10610)$ and $Z^+_b(10650)$. The bound bottom isosinglet molecule with $J^{PC}=1^{++}$ is a possible neutral $X_b(10532)$ to be observed.

  6. Heavy exotic molecules

    Science.gov (United States)

    Liu, Yizhuang; Zahed, Ismail

    We briefly review the formation of pion-mediated heavy-light exotic molecules with both charm and bottom, under the general structures of chiral and heavy quark symmetries. The charm isosinglet exotic molecules with JPC = 1++ binds, which we identify as the reported neutral X(3872). The bottom isotriplet exotic with JPC = 1+1 binds, and is identified as a mixed state of the reported charged exotics Zb+(10610) and Zb-(10650). The bound bottom isosinglet molecule with JPC = 1++ is a possible neutral Xb(10532) to be observed.

  7. Electron correlation in molecules

    CERN Document Server

    Wilson, S

    2007-01-01

    Electron correlation effects are of vital significance to the calculation of potential energy curves and surfaces, the study of molecular excitation processes, and in the theory of electron-molecule scattering. This text describes methods for addressing one of theoretical chemistry's central problems, the study of electron correlation effects in molecules.Although the energy associated with electron correlation is a small fraction of the total energy of an atom or molecule, it is of the same order of magnitude as most energies of chemical interest. If the solution of quantum mechanical equatio

  8. Military installation sequestered more carbon than surrounding areas

    Science.gov (United States)

    Zhao, S.; Liu, S.; Li, Z.; Sohl, T.

    2008-12-01

    Land use activities greatly affect the temporal trends and spatial patterns of regional land-atmospheric exchange of carbon. Military installations generally have drastically different land management strategies from surrounding areas, and the carbon consequences have never been quantified and assessed. Here, we used the General Ensemble Biogeochemical Modeling System (GEMS) to simulate and compare ecosystem carbon dynamics between Fort Benning and surrounding areas from 1992 to 2050. GEMS was driven by unique combinations of spatial and temporal dynamics of major driving forces, such as climate, soil properties, nitrogen deposition, and land use and land cover changes (predicted by FOREcasting SCEnarios of land cover change (FORE-SCE)). Our results indicated that the military installation sequestered more carbon than surrounding areas (0.77 vs. 0.16 Mg C ha-1 y-1 averaged from 1992 to 2007). Differences in land use activities were the primary cause behind the difference in carbon sequestration rates. From 1992 to 2007, no urban/residential expansion occurred at the installation, and transitional barren (primarily caused by forest harvesting) slightly increased from 0 to 0.2%. In contrast, urban land increased from 5.6 to 7.6% and transitional barren increased from 0.1 to 0.7% in the surrounding areas. Live biomass accumulation accounted for most of the carbon sink in both Fort Benning and surrounding areas (0.75 vs. 0.15 Mg C ha-1 y-1), while soil organic carbon accumulation was small (0.02 vs. 0.01 Mg C ha- 1 y-1), suggesting biomass removal caused by urbanization and harvesting resulted in much less carbon sequestration in surrounding areas. Fort Benning is likely to sequester more carbon in the future, although the rate of carbon sequestered per year will gradually reduce. The future carbon source/sink strength in the surrounding areas varied greatly, from a small sink to a strong source, depending on the path of land use change (e.g., increase of clear

  9. Test studies of gas flow in rock and coal surrounding a mined coal seam

    Institute of Scientific and Technical Information of China (English)

    Lv Youchang

    2012-01-01

    An analysis of the variation rule of abutment pressure at the mining working face in a single coal seam and the mechanical behavior of surrounding rock during stoping is presented.Consideration of the elastic and plastic deformation zones that develop during the mining process allowed the determination of a relationship between horizontal stress and vertical stress.Based on this,a confined pressure unloading test was conducted by the use of the "gas-containing coal thermo-fluid-solid coupling 3-axis servo seepage" experimental apparatus.Thus,gas flow patterns in the elastic and plastic zones were derived from an experimental point of view.Darcy's law and the Klinkenberg effect were used to derive a gas flow equation for the elastic and plastic stress fields.The study of gas flow phenomena at the working face during coal mining is of great importance for the study of gas migration and enrichment oatterns.

  10. Fluid dynamic constraints on resource acquisition in small pelagic organisms

    DEFF Research Database (Denmark)

    Kiørboe, Thomas

    2016-01-01

    by the application of formal fluid physics. Here, I examine resource acquisition mechanisms in small aquatic organisms, ranging from uptake of dissolved molecules to feeding on suspended particulate prey, and examine how organism behaviors and morphologies may be shaped by the often non-intuitive small-scale fluid...

  11. Poster on MPI application in Computational Fluid Dynamics

    OpenAIRE

    Argentini, Gianluca

    2003-01-01

    Poster-presentation of the paper "Message Passing Fluids: molecules as processes in parallel computational fluids" held at "EURO PVMMPI 2003" Congress; the paper is on the proceedings "Recent Advances in Parallel Virtual Machine and Message Passing Interface", 10th European PVM/MPI User's Group Meeting, LNCS 2840, Springer-Verlag, Dongarra-Laforenza-Orlando editors, pp. 550-554.

  12. Single molecules and nanotechnology

    CERN Document Server

    Vogel, Horst

    2007-01-01

    This book focuses on recent advances in the rapidly evolving field of single molecule research. These advances are of importance for the investigation of biopolymers and cellular biochemical reactions, and are essential to the development of quantitative biology. Written by leading experts in the field, the articles cover a broad range of topics, including: quantum photonics of organic dyes and inorganic nanoparticles their use in detecting properties of single molecules the monitoring of single molecule (enzymatic) reactions single protein (un)folding in nanometer-sized confined volumes the dynamics of molecular interactions in biological cells The book is written for advanced students and scientists who wish to survey the concepts, techniques and results of single molecule research and assess them for their own scientific activities.

  13. Electron-molecule collisions

    CERN Document Server

    Takayanagi, Kazuo

    1984-01-01

    Scattering phenomena play an important role in modern physics. Many significant discoveries have been made through collision experiments. Amongst diverse kinds of collision systems, this book sheds light on the collision of an electron with a molecule. The electron-molecule collision provides a basic scattering problem. It is scattering by a nonspherical, multicentered composite particle with its centers having degrees of freedom of motion. The molecule can even disintegrate, Le., dissociate or ionize into fragments, some or all of which may also be molecules. Although it is a difficult problem, the recent theoretical, experimental, and computational progress has been so significant as to warrant publication of a book that specializes in this field. The progress owes partly to technical develop­ ments in measurements and computations. No less important has been the great and continuing stimulus from such fields of application as astrophysics, the physics of the earth's upper atmosphere, laser physics, radiat...

  14. Quantum dot molecules

    CERN Document Server

    Wu, Jiang

    2014-01-01

    This book reviews recent advances in the exciting and rapidly growing field of quantum dot molecules (QDMs). It offers state-of-the-art coverage of novel techniques and connects fundamental physical properties with device design.

  15. Reduction of Heat Emission to Surroundings From Improved Wood Burning Stove

    Directory of Open Access Journals (Sweden)

    Zakariya Kaneesamkandi

    2014-12-01

    Full Text Available Apart from emissions and inefficiency, heat generation from wood stoves to the surroundings is another undesirable effect causing health repercussions especially in the small dwellings of tropical regions. The present research addresses this problem. Steady state temperature measurements on the surface of the improved wood burning stove is used to determine this loss in which chimney draft control plays an important role. Experimental results were in good agreement with that of the model simulated using the commercial computational fluid dynamics code. A modified model in which changes were introduced to reduce the radiation and convection losses from the stove to the surrounding regions was simulated. Firstly, the radiation losses from the fire was reduced by reducing the size of fuel supply port. Secondly, a waste heat recovery system was introduced which resulted in lower stove body temperature. This was done by optimizing the use of the draft produced by the chimney.Results of the modified model of the stove showed a reduction of this loss by 12.08%. Stoves currently used under the national project for rural energy development was used for this purpose. Apart from improving the stove efficiency, this development will have a positive impact on the acceptability of the improved wood stove in rural households and also help to further reduce fuel consumption.

  16. Auxillary Fluid Flowmeter

    DEFF Research Database (Denmark)

    RezaNejad Gatabi, Javad; Forouzbakhsh, Farshid; Ebrahimi Darkhaneh, Hadi

    2010-01-01

    and with measuring its travel time between two different positions, its velocity could be calculated. Given the velocity of the auxiliary fluid, the velocity of the main fluid could be calculated. Using this technique, it is possible to measure the velocity of any kind of fluids, if an appropriate auxiliary fluid...

  17. Fluid mechanics in fluids at rest.

    Science.gov (United States)

    Brenner, Howard

    2012-07-01

    Using readily available experimental thermophoretic particle-velocity data it is shown, contrary to current teachings, that for the case of compressible flows independent dye- and particle-tracer velocity measurements of the local fluid velocity at a point in a flowing fluid do not generally result in the same fluid velocity measure. Rather, tracer-velocity equality holds only for incompressible flows. For compressible fluids, each type of tracer is shown to monitor a fundamentally different fluid velocity, with (i) a dye (or any other such molecular-tagging scheme) measuring the fluid's mass velocity v appearing in the continuity equation and (ii) a small, physicochemically and thermally inert, macroscopic (i.e., non-Brownian), solid particle measuring the fluid's volume velocity v(v). The term "compressibility" as used here includes not only pressure effects on density, but also temperature effects thereon. (For example, owing to a liquid's generally nonzero isobaric coefficient of thermal expansion, nonisothermal liquid flows are to be regarded as compressible despite the general perception of liquids as being incompressible.) Recognition of the fact that two independent fluid velocities, mass- and volume-based, are formally required to model continuum fluid behavior impacts on the foundations of contemporary (monovelocity) fluid mechanics. Included therein are the Navier-Stokes-Fourier equations, which are now seen to apply only to incompressible fluids (a fact well-known, empirically, to experimental gas kineticists). The findings of a difference in tracer velocities heralds the introduction into fluid mechanics of a general bipartite theory of fluid mechanics, bivelocity hydrodynamics [Brenner, Int. J. Eng. Sci. 54, 67 (2012)], differing from conventional hydrodynamics in situations entailing compressible flows and reducing to conventional hydrodynamics when the flow is incompressible, while being applicable to both liquids and gases.

  18. Videotapes and Movies on Fluid Dynamics and Fluid Machines

    OpenAIRE

    Carr, Bobbie; Young, Virginia E.

    1996-01-01

    Chapter 17 of Handbook of Fluid Dynamics and Fluid Machinery: Experimental and Computational Fluid Dynamics, Volume 11. A list of videorecordings and 16mm motion pictures about Fluid Dynamics and Fluid Machines.

  19. The role of vortices in animal locomotion in fluids

    Directory of Open Access Journals (Sweden)

    Dvořák R.

    2014-12-01

    Full Text Available The aim of this paper is to show the significance of vortices in animal locomotion in fluids on two deliberately chosen examples. The first example concerns lift generation by bird and insect wings, the second example briefly mentiones swimming and walking on water. In all the examples, the vortices generated by the moving animal impart the necessary momentum to the surrounding fluid, the reaction to which is the force moving or lifting the animal.

  20. On a static charged fluid around a magnetized mass

    CERN Document Server

    Cabrera-Munguia, I

    2008-01-01

    We show that any magnetostatic axially symmetric solution of the Einstein-Maxwell equations can be endowed with a specific charged fluid source of the Polanco et al type via a simple procedure requiring the knowledge of exclusively the magnetostatic seed spacetime. Using this procedure we construct yet another exact solution for a massive magnetic dipole surrounded by a static charged fluid which is different from the Polanco et al metric.

  1. Proteomic analysis of the early bovine yolk sac fluid and cells from the day 13 ovoid and elongated preimplatation embryos

    DEFF Research Database (Denmark)

    Jensen, Pernille L.; Beck, Hans Christian; Petersen, Tonny S.

    2014-01-01

    differentiate into the hypoblast and epiblast, which remain surrounded by the trophectoderm. The formation of the hypoblast epithelium is also accompanied by a change in the fluid within the embryo, i.e., the blastocoel fluid gradually alters to become the primitive yolk sac (YS) fluid. Our previous research...

  2. Intrabronchial Microdialysis: Effects of Probe Localization on Tissue Trauma and Drug Penetration into the Pulmonary Epithelial Lining Fluid

    DEFF Research Database (Denmark)

    Rottbøll, Lisa Amanda Holm; Skovgaard, Kerstin; Barington, Kristiane

    2015-01-01

    Recent intrabronchial microdialysis data indicate that the respiratory epithelium is highly permeable to drugs. Of concern is whether intrabronchial microdialysis disrupts the integrity of the respiratory epithelium and thereby alters drug penetration into the pulmonary epithelial lining fluid...... pigs. Inulin was used as a marker molecule of permeability of the epithelium, and florfenicol was used as test drug. Bronchial tissue was examined by histopathology (distal and proximal bronchi) and gene expression analysis (RT-qPCR, proximal bronchi) at the termination of the experiment (6.5hr......). The microdialysis probe caused overt tissue trauma in distal bronchi, whereas no histopathological lesions were observed in proximal bronchi. A moderate up-regulation of the pro-inflammatory cytokines IL1B, IL6 and acute-phase reactant serum amyloid A was seen in proximal bronchi surrounding the microdialysis...

  3. The cylindrical magnetic Rayleigh-Taylor instability for viscous fluids

    Energy Technology Data Exchange (ETDEWEB)

    Chambers, K.; Forbes, L. K. [School of Mathematics and Physics, University of Tasmania, Private Bag 37-Hobart, Tasmania 7005 (Australia)

    2012-10-15

    This paper considers a cylindrical Rayleigh-Taylor instability, in which a heavy fluid surrounds a light fluid, and gravity is directed radially inwards. A massive object is located at the centre of the light fluid, and it behaves like a line dipole both for fluid flow and magnetic field strength. The initially circular interface between the two conducting fluids evolves into plumes, dependent on the magnetic and fluid dipole strengths and the nature of the initial disturbance to the interface. A spectral method is presented to solve the time-dependent interface shapes, and results are presented and discussed. Bipolar solutions are possible, and these are of particular relevance to astrophysics. The solutions obtained resemble structures of some HII regions and nebulae.

  4. Study on Temperature Fieldof Surrounding Rock with BEM

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The authors analyzed the characteristic of surrounding rock temperature field around a drifting face, setup its mathematic model, and got its numerical result with the boundary element method(BEM). To calculate in-tra-domain integral, it was transformed into boundary integration with the DRM method. Using the similitude the-ory, the dimensionless differential equation was educed. Finally, the authors calculated two drifting faces of San-hejian Coal Mine using the computer software developed by authors based on the above principium, and got the dis-tribution characteristic of surrounding rock temperature field around a drifting face and the periodic variation intemperature with its periodic moving forward. Comparing the calculated heat dissipating-capacity of surroundingrock with the measured data shows that the computer software is proper.

  5. Experimental Study of Deformation of Surrounding Rock with Infrared Radiation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yong-jun; AN Li-qian; REN Run-hou; FAN Shi-min; MA Nian-jie; LI Jian-hui; JI Yuan-ming

    2005-01-01

    According to the practical conditions of coal roadway in Changcun Coal Mine of Lu'an Mining Group, the deformation of rock surrounding roadway was experimentally studied by means of thermal infrared (TIR) imaging system in the process of confined compressions. It is found that the model surface TIR temperature (TIRT) changes with the increase of load. Furthermore, TIRT changes non-synchronously in different ranges such as the roof, floor, wall, corners and bolted ranges. The TIRT is higher in the location of stress concentration and bolted ranges than that in the location of stress relaxation and broken ranges. The interaction ranges of bolt and rock are determined preliminarily according to the corresponding relationship of TIRT fields and the strain fields of the surrounding rock. The new method of TIR image processing has been proved to be effective for the study of bolt support and observation of roadway stability under mine pressure.

  6. Optical detection of carotenoid antioxidants in human bone and surrounding tissue.

    Science.gov (United States)

    Ermakov, Igor V; Ermakova, Maia R; Rosenberg, Thomas D; Gellermann, Werner

    2013-11-01

    Carotenoids are known to play an important role in health and disease state of living human tissue based on their antioxidant and optical filtering functions. In this study, we show that carotenoids exist in human bone and surrounding fatty tissue both in significant and individually variable concentrations. Measurements of biopsied tissue samples with molecule-specific Raman spectroscopy and high-performance liquid chromatography reveal that all carotenoids that are known to exist in human skin are also present in human bone. This includes all carotenes, lycopene, β-cryptoxanthin, lutein, and zeaxanthin. We propose quantitative reflection imaging as a noncontact optical method suitable for the measurement of composite carotenoid levels in bone and surrounding tissue exposed during open surgeries such as total knee arthroplasty, and as a proof of concept, demonstrate carotenoid measurements in biopsied bone samples. This will allow one to establish potential correlations between internal tissue carotenoid levels and levels in skin and to potentially use already existing optical skin carotenoid tests as surrogate marker for bone carotenoid status.

  7. High resolution bathymetry of China seas and their surroundings

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Based on the oceanic lithospheric flexure and the worldwide bathymetric data ETOPO5, the high resolu tion bathymetry of the China seas and their surroundings is computed from altimeter derived gravity anomalies. The new bathymetry obtained by this study is higher resolution and accuracy than the widely used ETOPO5 data, mean while it shows clearly the seafioor, the tectonic characteristics and the geodynamical processes in the China seas.

  8. Thermodynamic stability of black holes surrounded by quintessence

    OpenAIRE

    Ma, Meng-Sen; Zhao, Ren; Ma, Ya-Qin

    2016-01-01

    We study the thermodynamic stabilities of uncharged and charged black holes surrounded by quintessence (BHQ) by means of effective thermodynamic quantities. When the state parameter of quintessence $\\omega_q$ is appropriately chosen, the structures of BHQ are something like that of black holes in de Sitter space. Constructing the effective first law of thermodynamics in two different ways, we can derive the effective thermodynamic quantities of BHQ. Especially, these effective thermodynamic q...

  9. Hidden History: A Mobile Application for Discovering Surrounding Landscapes

    OpenAIRE

    2016-01-01

    This thesis work describes the design, development and evaluation of a mobile application called Hidden History. This application lets users discover and explore three types of landscapes (Historic, Scenic and Cultural) using three different modes of discovery (Route, Explore and Tour). Before designing Hidden History, the feature set of other applications that help users explore surrounding landscapes were identified and analyzed. Hidden History was then designed to implement the best fea...

  10. Treatment of Postherpetic Neuralgia by Surround Needling with Electric Stimulation

    Institute of Scientific and Technical Information of China (English)

    FAN Jin; YANG Qin-hua

    2005-01-01

    运用电针围刺法治疗带状疱疹后遗神经痛29例,获得较好疗效,总有效率为93.1%.%Twenty-nine cases of postherpetic neuralgia of herpes zoster were treated by the surround needling with electric stimulation, and the better therapeutic effect was obtained, the total effective rate was 93.1%.

  11. Belief and Attitudes surrounding Childhood Autism in Ghana

    OpenAIRE

    2012-01-01

    Autism is a life-long invisible impairment with an unknown etiology. Current literature shows an increase in the diagnosis of autism worldwide. This qualitative study explores the attitudes and beliefs which surround childhood autism in Ghana. In-depth interviews were conducted with four (4) parents whose children have autism and three (3) key informants; a Religious Leader, a Health Worker and an Administrator of a Special school in Accra, Ghana. A semi-structured interview guide was used fo...

  12. A permeability barrier surrounds taste buds in lingual epithelia.

    Science.gov (United States)

    Dando, Robin; Pereira, Elizabeth; Kurian, Mani; Barro-Soria, Rene; Chaudhari, Nirupa; Roper, Stephen D

    2015-01-01

    Epithelial tissues are characterized by specialized cell-cell junctions, typically localized to the apical regions of cells. These junctions are formed by interacting membrane proteins and by cytoskeletal and extracellular matrix components. Within the lingual epithelium, tight junctions join the apical tips of the gustatory sensory cells in taste buds. These junctions constitute a selective barrier that limits penetration of chemosensory stimuli into taste buds (Michlig et al. J Comp Neurol 502: 1003-1011, 2007). We tested the ability of chemical compounds to permeate into sensory end organs in the lingual epithelium. Our findings reveal a robust barrier that surrounds the entire body of taste buds, not limited to the apical tight junctions. This barrier prevents penetration of many, but not all, compounds, whether they are applied topically, injected into the parenchyma of the tongue, or circulating in the blood supply, into taste buds. Enzymatic treatments indicate that this barrier likely includes glycosaminoglycans, as it was disrupted by chondroitinase but, less effectively, by proteases. The barrier surrounding taste buds could also be disrupted by brief treatment of lingual tissue samples with DMSO. Brief exposure of lingual slices to DMSO did not affect the ability of taste buds within the slice to respond to chemical stimulation. The existence of a highly impermeable barrier surrounding taste buds and methods to break through this barrier may be relevant to basic research and to clinical treatments of taste.

  13. THE DESIGN OF DYNAMIC SIMULATION SYSTEM ON EARTHQUAKE SURROUNDINGS

    Institute of Scientific and Technical Information of China (English)

    沈毅力; 杨云; 李天石

    2003-01-01

    Objective To design a system that can simulate earthquake surroundings. In the surroundings, people can be familiar with the omen, strong shock and aftershock of earthquake, thus make right choices and get away when the disaster occurs. Methods The system consists of an electro-hydraulic servo system, a whole-information sound system and some lighting device; By using the adaptive inverse control method and LMS algorithms, the inverse model (I.e. The controller) is convergent rapidly; The software based on LabVIEW makes the parameters can be modified easily; There is a double closed-loop structure in the system: an analog closed-loop and a digital closed-loop, and their parameters can be inspected in real time. Results The system is of very high reliability, and the desired vibration signal can be tracked exactly by output. Conclusion Earthquake surroundings is simulated vividly. Through the system, people can be familiar with earthquake phenomena, and know lots of knowledge of earthquake.

  14. Tissue reaction surrounding miniscrews for orthodontic anchorage: An animal experiment

    Directory of Open Access Journals (Sweden)

    Stephanie Shih-Hsuan Chen

    2012-03-01

    Results and conclusions: (1 Tissue surrounding roots damaged by a miniscrew showed a significant inflammatory response. (2 Root resorption was occasionally observed after 3 weeks following insertion of a miniscrew even if the miniscrew was not in direct contact with the root. (3 Root repair was noted with a cementoblast lining along the resorption surface at as early as 3 weeks after miniscrew insertion. Alveolar bone filled in the lesion when the root damage was large so that the contour of the alveolar bone followed that of the damaged root, with the width of the periodontal ligament space being maintained. (4 Stable miniscrews were mainly those which did not contact adjacent roots, and for which the surrounding tissue showed only a small inflammatory response with some extent of direct bone contact around the miniscrew. On the contrary, most of the failed miniscrews were those which had direct contact with adjacent roots, and which exhibited severe tissue inflammation and were covered by thick layers of soft tissue. Failure was detected 3 weeks after insertion. Surprisingly, the epithelial lining surrounding the miniscrews might not have spontaneously resolved 6 weeks after screw removal. Persistent infection in the sinus tract was noted, and this would require attention.

  15. The Fluid Dynamics of Competitive Swimming

    Science.gov (United States)

    Wei, Timothy; Mark, Russell; Hutchison, Sean

    2014-01-01

    Nowhere in sport is performance so dependent on the interaction of the athlete with the surrounding medium than in competitive swimming. As a result, understanding (at least implicitly) and controlling (explicitly) the fluid dynamics of swimming are essential to earning a spot on the medal stand. This is an extremely complex, highly multidisciplinary problem with a broad spectrum of research approaches. This review attempts to provide a historical framework for the fluid dynamics-related aspects of human swimming research, principally conducted roughly over the past five decades, with an emphasis on the past 25 years. The literature is organized below to show a continuous integration of computational and experimental technologies into the sport. Illustrations from the authors' collaborations over a 10-year period, coupling the knowledge and experience of an elite-level coach, a lead biomechanician at USA Swimming, and an experimental fluid dynamicist, are intended to bring relevance and immediacy to the review.

  16. Fluid-driven fractures in brittle hydrogels

    Science.gov (United States)

    O'Keeffe, Niall; Linden, Paul

    2016-11-01

    Hydraulic fracturing is a process in which fluid is injected deep underground at high pressures that can overcome the strength of the surrounding matrix. This results in an increase of surface area connected to the well bore and thus allows extraction of natural gas previously trapped in a rock formation. We experimentally study the physical mechanisms of these fluid-driven fractures in low permeability reservoirs where the leak-off of fracturing fluid is considered negligible. This is done through the use of small scale experiments on transparent and brittle, heavily cross-linked hydrogels. The propagation of these fractures can be split into two distinct regimes depending on whether the dominant energy dissipation mechanism is viscous flow or material toughness. We will analyse crack growth rates, crack thickness and tip shape in both regimes. Moreover, PIV techniques allow us to explore the flow dynamics within the fracture, which is crucial in predicting transport of proppants designed to prevent localisation of cracks.

  17. Molecules as Automata

    Science.gov (United States)

    Cardelli, Luca

    Molecular biology investigates the structure and function of biochemical systems starting from their basic building blocks: macromolecules. A macromolecule is a large, complex molecule (a protein or a nucleic acid) that usually has inner mutable state and external activity. Informal explanations of biochemical events trace individual macromolecules through their state changes and their interaction histories: a macromolecule is endowed with an identity that is retained through its transformations, even through changes in molecular energy and mass. A macromolecule, therefore, is qualitatively different from the small molecules of inorganic chemistry. Such molecules are stateless: in the standard notation for chemical reactions they are seemingly created and destroyed, and their atomic structure is used mainly for the bookkeeping required by the conservation of mass.

  18. Molecules in supernova ejecta

    CERN Document Server

    Cherchneff, Isabelle

    2011-01-01

    The first molecules detected at infrared wavelengths in the ejecta of a Type II supernova, namely SN1987A, consisted of CO and SiO. Since then, confirmation of the formation of these two species in several other supernovae a few hundred days after explosion has been obtained. However, supernova environments appear to hamper the synthesis of large, complex species due to the lack of microscopically-mixed hydrogen deep in supernova cores. Because these environments also form carbon and silicate dust, it is of importance to understand the role played by molecules in the depletion of elements and how chemical species get incorporated into dust grains. In the present paper, we review our current knowledge of the molecular component of supernova ejecta, and present new trends and results on the synthesis of molecules in these harsh, explosive events.

  19. MOLECULES IN {eta} CARINAE

    Energy Technology Data Exchange (ETDEWEB)

    Loinard, Laurent; Menten, Karl M.; Guesten, Rolf [Max-Planck Institut fuer Radioastronomie, Auf dem Huegel 69, 53121 Bonn (Germany); Zapata, Luis A.; Rodriguez, Luis F. [Centro de Radioastronomia y Astrofisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 3-72, 58090 Morelia, Michoacan (Mexico)

    2012-04-10

    We report the detection toward {eta} Carinae of six new molecules, CO, CN, HCO{sup +}, HCN, HNC, and N{sub 2}H{sup +}, and of two of their less abundant isotopic counterparts, {sup 13}CO and H{sup 13}CN. The line profiles are moderately broad ({approx}100 km s{sup -1}), indicating that the emission originates in the dense, possibly clumpy, central arcsecond of the Homunculus Nebula. Contrary to previous claims, CO and HCO{sup +} do not appear to be underabundant in {eta} Carinae. On the other hand, molecules containing nitrogen or the {sup 13}C isotope of carbon are overabundant by about one order of magnitude. This demonstrates that, together with the dust responsible for the dimming of {eta} Carinae following the Great Eruption, the molecules detected here must have formed in situ out of CNO-processed stellar material.

  20. Molecules in \\eta\\ Carinae

    CERN Document Server

    Loinard, Laurent; Guesten, Rolf; Zapata, Luis A; Rodriguez, Luis F

    2012-01-01

    We report the detection toward \\eta\\ Carinae of six new molecules, CO, CN, HCO+, HCN, HNC, and N2H+, and of two of their less abundant isotopic counterparts, 13CO and H13CN. The line profiles are moderately broad (about 100 km /s) indicating that the emission originates in the dense, possibly clumpy, central arcsecond of the Homunculus Nebula. Contrary to previous claims, CO and HCO+ do not appear to be under-abundant in \\eta\\ Carinae. On the other hand, molecules containing nitrogen or the 13C isotope of carbon are overabundant by about one order of magnitude. This demonstrates that, together with the dust responsible for the dimming of eta Carinae following the Great Eruption, the molecules detected here must have formed in situ out of CNO-processed stellar material.

  1. Enzyme molecules as nanomotors.

    Science.gov (United States)

    Sengupta, Samudra; Dey, Krishna K; Muddana, Hari S; Tabouillot, Tristan; Ibele, Michael E; Butler, Peter J; Sen, Ayusman

    2013-01-30

    Using fluorescence correlation spectroscopy, we show that the diffusive movements of catalase enzyme molecules increase in the presence of the substrate, hydrogen peroxide, in a concentration-dependent manner. Employing a microfluidic device to generate a substrate concentration gradient, we show that both catalase and urease enzyme molecules spread toward areas of higher substrate concentration, a form of chemotaxis at the molecular scale. Using glucose oxidase and glucose to generate a hydrogen peroxide gradient, we induce the migration of catalase toward glucose oxidase, thereby showing that chemically interconnected enzymes can be drawn together.

  2. Multicolor Bound Soliton Molecule

    CERN Document Server

    Luo, Rui; Lin, Qiang

    2015-01-01

    We show a new class of bound soliton molecule that exists in a parametrically driven nonlinear optical cavity with appropriate dispersion characteristics. The composed solitons exhibit distinctive colors but coincide in time and share a common phase, bound together via strong inter-soliton four-wave mixing and Cherenkov radiation. The multicolor bound soliton molecule shows intriguing spectral locking characteristics and remarkable capability of spectrum management to tailor soliton frequencies, which may open up a great avenue towards versatile generation and manipulation of multi-octave spanning phase-locked Kerr frequency combs, with great potential for applications in frequency metrology, optical frequency synthesis, and spectroscopy.

  3. Gated container molecules

    Institute of Scientific and Technical Information of China (English)

    LIU Fang; WANG Hao; HOUK K. N.

    2011-01-01

    Donald J.Cram,the great UCLA chemist,received the Nobel Prize for his discoveries about host-guest complexes [1].Both theoretical and experimental studies have been conducted about the nature and strength of interactions between the host and guest molecules.The concepts of constrictive binding (the activation energy of the binding process) and intrinsic binding (the free energy difference between the complex and the free host and guest molecules) were introduced to characterize different binding properties (Figure 1)[2].

  4. Cerebrospinal fluid prohormone processing and neuropeptides stimulating feed intake of dairy cows during early lactation.

    Science.gov (United States)

    Kuhla, Björn; Laeger, Thomas; Husi, Holger; Mullen, William

    2015-02-01

    After parturition, feed intake of dairy cows increases within the first weeks of lactation, but the molecular mechanisms stimulating or delaying the slope of increase are poorly understood. Some of the molecules controlling feed intake are neuropeptides that are synthesized as propeptides and subsequently processed before they bind to specific receptors in feeding centers of the brain. Cerebrospinal fluid surrounds most of the feed intake regulatory centers and contains numerous neuropeptides. In the present study, we used a proteomic approach to analyze the neuropeptide concentrations in cerebrospinal fluid taken from dairy cows between day -18 and -10, and between day +10 and +20 relative to parturition. We found 13 proteins which were only present in samples taken before parturition, 13 proteins which were only present in samples taken after parturition, and 25 proteins which were commonly present, before and after parturition. Among them, differences in pro-neuropeptide Y, proenkephalin-A, neuroendocrine convertase-2, neurosecretory protein VGF, chromogranin-A, and secretogranin-1 and -3 concentrations relative to parturition highlight propeptides and prohormone processings involved in the control of feed intake and energy homeostasis. Scaffold analysis further emphasized an increased tone of endogenous opioids associated with the postparturient increase of feed intake.

  5. Synthesis beyond the molecule

    NARCIS (Netherlands)

    Reinhoudt, D.N.; Crego-Calama, M.

    2002-01-01

    Weak, noncovalent interactions between molecules control many biological functions. In chemistry, noncovalent interactions are now exploited for the synthesis in solution of large supramolecular aggregates. The aim of these syntheses is not only the creation of a particular structure, but also the i

  6. Disentangling DNA molecules.

    Science.gov (United States)

    Vologodskii, Alexander

    2016-09-01

    The widespread circular form of DNA molecules inside cells creates very serious topological problems during replication. Due to the helical structure of the double helix the parental strands of circular DNA form a link of very high order, and yet they have to be unlinked before the cell division. DNA topoisomerases, the enzymes that catalyze passing of one DNA segment through another, solve this problem in principle. However, it is very difficult to remove all entanglements between the replicated DNA molecules due to huge length of DNA comparing to the cell size. One strategy that nature uses to overcome this problem is to create the topoisomerases that can dramatically reduce the fraction of linked circular DNA molecules relative to the corresponding fraction at thermodynamic equilibrium. This striking property of the enzymes means that the enzymes that interact with DNA only locally can access their topology, a global property of circular DNA molecules. This review considers the experimental studies of the phenomenon and analyzes the theoretical models that have been suggested in attempts to explain it. We describe here how various models of enzyme action can be investigated computationally. There is no doubt at the moment that we understand basic principles governing enzyme action. Still, there are essential quantitative discrepancies between the experimental data and the theoretical predictions. We consider how these discrepancies can be overcome.

  7. Disentangling DNA molecules

    Science.gov (United States)

    Vologodskii, Alexander

    2016-09-01

    The widespread circular form of DNA molecules inside cells creates very serious topological problems during replication. Due to the helical structure of the double helix the parental strands of circular DNA form a link of very high order, and yet they have to be unlinked before the cell division. DNA topoisomerases, the enzymes that catalyze passing of one DNA segment through another, solve this problem in principle. However, it is very difficult to remove all entanglements between the replicated DNA molecules due to huge length of DNA comparing to the cell size. One strategy that nature uses to overcome this problem is to create the topoisomerases that can dramatically reduce the fraction of linked circular DNA molecules relative to the corresponding fraction at thermodynamic equilibrium. This striking property of the enzymes means that the enzymes that interact with DNA only locally can access their topology, a global property of circular DNA molecules. This review considers the experimental studies of the phenomenon and analyzes the theoretical models that have been suggested in attempts to explain it. We describe here how various models of enzyme action can be investigated computationally. There is no doubt at the moment that we understand basic principles governing enzyme action. Still, there are essential quantitative discrepancies between the experimental data and the theoretical predictions. We consider how these discrepancies can be overcome.

  8. Diversity in Biological Molecules

    Science.gov (United States)

    Newbury, H. John

    2010-01-01

    One of the striking characteristics of fundamental biological processes, such as genetic inheritance, development and primary metabolism, is the limited amount of variation in the molecules involved. Natural selective pressures act strongly on these core processes and individuals carrying mutations and producing slightly sub-optimal versions of…

  9. Diversity in Biological Molecules

    Science.gov (United States)

    Newbury, H. John

    2010-01-01

    One of the striking characteristics of fundamental biological processes, such as genetic inheritance, development and primary metabolism, is the limited amount of variation in the molecules involved. Natural selective pressures act strongly on these core processes and individuals carrying mutations and producing slightly sub-optimal versions of…

  10. Atoms, Molecules, and Compounds

    CERN Document Server

    Manning, Phillip

    2007-01-01

    Explores the atoms that govern chemical processes. This book shows how the interactions between simple substances such as salt and water are crucial to life on Earth and how those interactions are predestined by the atoms that make up the molecules.

  11. Properties of entanglement molecules

    Energy Technology Data Exchange (ETDEWEB)

    Huang Yanxia [Department of Physics, Hubei Normal University, Huangshi 435002 (China); Zhan Mingsheng [State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China)

    2004-09-14

    We propose a scheme to prepare a certain kind of N-atom entangled state that allows us to construct some possible types of entanglement molecules via cavity QED. The entanglement properties of entanglement molecules vertical bar {psi}{sub N}){sub {alpha}} are studied with respect to bipartite entanglement that is robust against the disposal of particles and are compared with entanglement molecules {rho}{sub I} introduced in Dur (2001 Phys. Rev. A 63 020303). We also give the maximal amount of entanglement achievable for two particular situations in two possible configurations. Meanwhile, we investigate the entanglement properties of entanglement molecules vertical bar {psi}{sub N}){sub {alpha}} in terms of local measurement using the maximum connectedness and persistency and compare them with other kinds of N-atom entangled states such as |GHZ), vertical bar W{sub N}) and vertical bar {phi}{sub N}). We show that the maximal value N - 1 of the persistency of the state vertical bar {psi}{sub N}){sub {alpha}} corresponds to the case that all atoms are pairwise entangled. If any pair of atoms {rho}{sub ij} is disentangled, the entanglement of the state vertical bar {psi}{sub N}){sub {alpha}} is very easy to destroy by a single local measurement.

  12. Properties of entanglement molecules

    Science.gov (United States)

    Huang, Yan-Xia; Zhan, Ming-Sheng

    2004-09-01

    We propose a scheme to prepare a certain kind of N-atom entangled state that allows us to construct some possible types of entanglement molecules via cavity QED. The entanglement properties of entanglement molecules |psgrNrangagr are studied with respect to bipartite entanglement that is robust against the disposal of particles and are compared with entanglement molecules rgrI introduced in Dur (2001 Phys. Rev. A 63 020303). We also give the maximal amount of entanglement achievable for two particular situations in two possible configurations. Meanwhile, we investigate the entanglement properties of entanglement molecules |psgrNrangagr in terms of local measurement using the maximum connectedness and persistency and compare them with other kinds of N-atom entangled states such as |GHZrang, |WNrang and |phgrNrang. We show that the maximal value N - 1 of the persistency of the state |psgrNrangagr corresponds to the case that all atoms are pairwise entangled. If any pair of atoms rgrij is disentangled, the entanglement of the state |psgrNrangagr is very easy to destroy by a single local measurement.

  13. INTERACTIONS OF THE INFRARED BUBBLE N4 WITH ITS SURROUNDINGS

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hong-Li; Li, Jin-Zeng; Yuan, Jing-Hua; Huang, Maohai; Huang, Ya-Fang; Zhang, Si-Ju [National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012 (China); Wu, Yuefang [Department of Astronomy, Peking University, 100871 Beijing (China); Liu, Tie [Korea Astronomy and Space Science Institute 776, Daedeokdae-ro, Yuseong-gu, Daejeon, 305-348 (Korea, Republic of); Dubner, G.; Paron, S.; Ortega, M. E. [1Instituto de Astronomía y Física del Espacio (IAFE, CONICET-UBA), CC 67, Suc. 28, 1428 Buenos Aires (Argentina); Molinari, Sergio [Istituto di Astrofisica e Planetologia Spaziali—IAPS, Istituto Nazionale di Astrofisica—INAF, via Fosso del Cavaliere 100, I-00133 Roma (Italy); Zavagno, Annie; Samal, Manash R., E-mail: hlliu@nao.cas.cn [Aix Marseille Universit, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, F-13388, Marseille (France)

    2016-02-10

    The physical mechanisms that induce the transformation of a certain mass of gas in new stars are far from being well understood. Infrared bubbles associated with H ii regions have been considered to be good samples for investigating triggered star formation. In this paper we report on the investigation of the dust properties of the infrared bubble N4 around the H ii region G11.898+0.747, analyzing its interaction with its surroundings and star formation histories therein, with the aim of determining the possibility of star formation triggered by the expansion of the bubble. Using Herschel PACS and SPIRE images with a wide wavelength coverage, we reveal the dust properties over the entire bubble. Meanwhile, we are able to identify six dust clumps surrounding the bubble, with a mean size of 0.50 pc, temperature of about 22 K, mean column density of 1.7 × 10{sup 22} cm{sup −2}, mean volume density of about 4.4 × 10{sup 4} cm{sup −3}, and a mean mass of 320 M{sub ⊙}. In addition, from PAH emission seen at 8 μm, free–free emission detected at 20 cm, and a probability density function in special regions, we could identify clear signatures of the influence of the H ii region on the surroundings. There are hints of star formation, though further investigation is required to demonstrate that N4 is the triggering source.

  14. On the environment surrounding close-in exoplanets

    Science.gov (United States)

    Vidotto, A. A.; Fares, R.; Jardine, M.; Moutou, C.; Donati, J.-F.

    2015-06-01

    Exoplanets in extremely close-in orbits are immersed in a local interplanetary medium (i.e. the stellar wind) much denser than the local conditions encountered around the Solar system planets. The environment surrounding these exoplanets also differs in terms of dynamics (slower stellar winds, but higher Keplerian velocities) and ambient magnetic fields (likely higher for host stars more active than the Sun). Here, we quantitatively investigate the nature of the interplanetary media surrounding the hot Jupiters HD 46375b, HD 73256b, HD 102195b, HD 130322b and HD 179949b. We simulate the three-dimensional winds of their host stars, in which we directly incorporate their observed surface magnetic fields. With that, we derive mass-loss rates (1.9-8.0 × 10-13 M⊙ yr-1) and the wind properties at the position of the hot Jupiters' orbits (temperature, velocity, magnetic field intensity and pressure). We show that these exoplanets' orbits are supermagnetosonic, indicating that bow shocks are formed surrounding these planets. Assuming planetary magnetic fields similar to Jupiter's, we estimate planetary magnetospheric sizes of 4.1-5.6 planetary radii. We also derive the exoplanetary radio emission released in the dissipation of the stellar wind energy. We find radio fluxes ranging from 0.02 to 0.13 mJy, which are challenging to be observed with present-day technology, but could be detectable with future higher sensitivity arrays (e.g. Square Kilometre Array). Radio emission from systems having closer hot Jupiters, such as from τ Boo b or HD 189733b, or from nearby planetary systems orbiting young stars, are likely to have higher radio fluxes, presenting better prospects for detecting exoplanetary radio emission.

  15. Static charged fluid around a massive magnetic dipole

    CERN Document Server

    Polanco, Jose D; Ujevic, Maximiliano

    2008-01-01

    An analytical solution of Einstein-Maxwell equations with a static fluid as a source is presented. The spacetime is represented by the axially symmetric Weyl metric and the energy-momentum tensor describes a coupling of a fluid with an electromagnetic field. When appropriate limits are performed we recover the well-known solutions of Gutsunaev-Manko and Schwarzschild. Also, using Eckart's thermodynamics, we calculated the temperature, the mechanical pressure, the charge density and the energy density of the system. The analysis of thermodynamic quantities suggests that the solution can be used to represent a magnetized compact stellar object surrounded by a charged fluid.

  16. Modeling of Dynamic Fluid Forces in Fast Switching Valves

    DEFF Research Database (Denmark)

    Roemer, Daniel Beck; Johansen, Per; Pedersen, Henrik Clemmensen

    2015-01-01

    Switching valves experience opposing fluid forces due to movement of the moving member itself, as the surrounding fluid volume must move to accommodate the movement. This movement-induced fluid force may be divided into three main components; the added mass term, the viscous term and the socalled...... is given using an analytically solvable example, showing the explicit form of the force terms and highlighting the significance of the added mass and history term in certain fast switching valve applications. A general approximate model for arbitrary valve geometries is then proposed with offset...

  17. Issues surrounding record keeping in district nursing practice.

    Science.gov (United States)

    Anderson, E E

    2000-07-01

    This article examines some aspects of nursing documentation following the publication of the document 'Guidelines for Records and Record Keeping' (UKCC, 1998). The importance of nursing documentation in patient care, in guiding practice and in providing information for members of the interprofessional healthcare team is highlighted. Record keeping forms an important part of the clinical governance initiative in terms of quality improvement and risk management. The issues surrounding the legal requirements of record keeping in district nursing practice are discussed. Suggestions are made for assessing the quality of nursing documentation by audit and research, in order to establish the suitability of using the present systems in the community setting.

  18. Induced radioactivity in a 4 MW target and its surroundings

    CERN Document Server

    Agosteo, Stefano; Otto, Thomas; Silari, Marco

    2003-01-01

    An important aspect of a future CERN Neutrino Factory is the material activation arising from a 2.2 GeV, 4 MW proton beam striking a mercury target. An estimation of the hadronic inelastic interactions and the production of residual nuclei in the target, the magnetic horn, the decay tunnel, the surrounding rock and a downstream dump was performed by the Monte Carlo hadronic cascade code FLUKA. The aim was both to assess the dose equivalent rate to be expected during maintenance work and to evaluate the amount of residual radioactivity, which will have to be disposed of after the facility has ceased operation.

  19. Mutual seismic interaction between tunnels and the surrounding granular soil

    Directory of Open Access Journals (Sweden)

    Mohamed Ahmed Abdel-Motaal

    2014-12-01

    Study results show that the maximum exerted straining actions in tunnel lining are directly proportional to the relative stiffness between tunnel and surrounding soil (lining thickness and soil shear modulus. Moreover, it is highly affected by the peak ground acceleration and the tunnel location (embedment depth. A comprehensive study is performed to show the effect of tunnel thickness and tunnel diameter on both the induced bending moment and lining deformation. In general, it is concluded that seismic analysis should be considered in regions subjected to peak ground acceleration greater than 0.15g.

  20. Problems Surrounding Probation In The South African Public Service

    Directory of Open Access Journals (Sweden)

    Z. Baloyi

    2006-11-01

    Full Text Available The aim of the study was to investigate problems surrounding probation periods in the South African Public Service. A qualitative study was conducted to determine the views of both probationers and supervisors managing the probation process. Data was gathered by means of focus groups and individual interviews. Nine key areas were identified as being problematic, viz. clarity regarding the purpose of probation, lack of proper guidelines, the duration of probation, rotation during probation, lack of training, poor management of probation, performance management, anxiety and stress, power and authority. Recommendations are made concerning possible interventions.

  1. On the flow in an annulus surrounding a whirling cylinder

    Science.gov (United States)

    Brennen, C.

    1976-01-01

    When fluid in an annulus between two cylinders is set in motion by whirling movements of one or both of the cylinders, dynamic forces are imposed by the fluid on the cylinders. Knowledge of these forces is frequently important, indeed often critical, to the engineer designing rotor systems or journal bearings. Quite general solutions of the Navier-Stokes equations are presented for this problem and are limited only by restrictions on the amplitude of the whirl motion. From these solutions, the forces are derived under a wide variety of circumstances, including large and small annular widths, high and low Reynolds numbers, and the presence and absence of a mean flow created by additional net rotation of one or both of the cylinders.

  2. Bacterial invasion reconstructed molecule by molecule

    Energy Technology Data Exchange (ETDEWEB)

    Werner, James H [Los Alamos National Laboratory

    2009-01-01

    We propose to visualize the initial stages of bacterial infection of a human host cell with unmatched spatial and temporal resolution. This work will develop a new capability for the laboratory (super-resolution optical imaging), will test unresolved scientific hypotheses regarding host-pathogen interaction dynamics, and leverages state of the art 3D molecular tracking instrumentation developed recently by our group. There is much to be gained by applying new single molecule tools to the important and familiar problem of pathogen entry into a host cell. For example, conventional fluorescence microscopy has identified key host receptors, such as CD44 and {alpha}5{beta}1 integrin, that aggregate near the site of Salmonella typhimurium infection of human cells. However, due to the small size of the bacteria ({approx} 2 {micro}m) and the diffraction of the emitted light, one just sees a fluorescent 'blob' of host receptors that aggregate at the site of attachment, making it difficult to determine the exact number of receptors present or whether there is any particular spatial arrangement of the receptors that facilitates bacterial adhesion/entry. Using newly developed single molecule based super-resolution imaging methods, we will visualize how host receptors are directed to the site of pathogen adhesion and whether host receptors adopt a specific spatial arrangement for successful infection. Furthermore, we will employ our 3D molecular tracking methods to follow the injection of virulence proteins, or effectors, into the host cell by the pathogen Type III secretion system (TTSS). We expect these studies to provide mechanistic insights into the early events of pathogen infection that have here-to-fore been technically beyond our reach. Our Research Goals are: Goal 1--Construct a super-resolution fluorescence microscope and use this new capability to image the spatial distribution of different host receptors (e.g. CD44, as {alpha}5{beta}1 integrin) at the

  3. Resonance scattering of canonical elastic shells in absorbing fluid medium

    Institute of Scientific and Technical Information of China (English)

    ZHUO Linkai; FAN Jun; TANG Weilin

    2008-01-01

    Resonance scattering of elastic spherical shell and cylindrical shell while the sur-rounding fluid medium has absorption is studied. The normal mode solution derived using exact elastic theory and the separation of variables is still applicable. However, the scattering form function has to be modified for the absorbing medium, otherwise the unreasonable resul twould be obtained. The backscattering form function in the absorbing medium is redefined, and the form function of elastic spherical and cylindrical shell with vacuum or solid matter filled is calculated in various absorption conditions. The results show that the absorption of surround-ing fluid leads to notable attenuation of the coincidence resonances in the mid-frequency, but it has a little in fluence on the low-frequency resonance scattering induced by the filler inside the shell.

  4. Synovial fluid analysis

    Science.gov (United States)

    ... bursae (fluid-filled sacs in the joints), and tendon sheaths. After the joint area is cleaned, the ... HS. Synovial fluid analysis, synovial biopsy, and synovial pathology. In: Firestein GS, Budd RC, Gabriel SE, McInnes ...

  5. Pericardial Fluid Analysis

    Science.gov (United States)

    ... help diagnose the cause of inflammation of the pericardium (pericarditis) and/or fluid accumulation around the heart ( ... pressure within blood vessels or inflammation of the pericardium. An initial set of tests, including fluid protein ...

  6. Lectures on fluid mechanics

    CERN Document Server

    Shinbrot, Marvin

    2012-01-01

    Readable and user-friendly, this high-level introduction explores the derivation of the equations of fluid motion from statistical mechanics, classical theory, and a portion of the modern mathematical theory of viscous, incompressible fluids. 1973 edition.

  7. Electric fluid pump

    Science.gov (United States)

    Van Dam, Jeremy Daniel; Turnquist, Norman Arnold; Raminosoa, Tsarafidy; Shah, Manoj Ramprasad; Shen, Xiaochun

    2015-09-29

    An electric machine is presented. The electric machine includes a hollow rotor; and a stator disposed within the hollow rotor, the stator defining a flow channel. The hollow rotor includes a first end portion defining a fluid inlet, a second end portion defining a fluid outlet; the fluid inlet, the fluid outlet, and the flow channel of the stator being configured to allow passage of a fluid from the fluid inlet to the fluid outlet via the flow channel; and wherein the hollow rotor is characterized by a largest cross-sectional area of hollow rotor, and wherein the flow channel is characterized by a smallest cross-sectional area of the flow channel, wherein the smallest cross-sectional area of the flow channel is at least about 25% of the largest cross-sectional area of the hollow rotor. An electric fluid pump and a power generation system are also presented.

  8. Fluid force transducer

    Science.gov (United States)

    Jendrzejczyk, Joseph A.

    1982-01-01

    An electrical fluid force transducer for measuring the magnitude and direction of fluid forces caused by lateral fluid flow, includes a movable sleeve which is deflectable in response to the movement of fluid, and a rod fixed to the sleeve to translate forces applied to the sleeve to strain gauges attached to the rod, the strain gauges being connected in a bridge circuit arrangement enabling generation of a signal output indicative of the magnitude and direction of the force applied to the sleeve.

  9. Interactions of the Infrared bubble N4 with the surroundings

    CERN Document Server

    Liu, Hong-Li; Wu, Yuefang; Yuan, Jing-Hua; Liu, Tie; Dubner, G; Paron, S; Ortega, M E; Molinari, Sergio; Huang, Maohai; Zavagno, Annie; Samal, Manash R; Huang, Ya-Fang; Zhang, Si-Ju

    2016-01-01

    The physical mechanisms that induce the transformation of a certain mass of gas in new stars are far from being well understood. Infrared bubbles associated with HII regions have been considered to be a good sample to investigate triggered star formation. In this paper we report on the investigation of the dust properties of the infrared bubble N4 around the HII region G11.898+0.747, analyzing its interaction with the surroundings and star formation histories therein, aiming at determining the possibility of star formation triggered by the expansion of the bubble. Using Herschel PACS and SPIRE images with a wide wavelength coverage, we reveal the dust properties over the entire bubble. Meanwhile, we are able to identify six dust clumps surrounding the bubble, with a mean size of 0.50 pc, temperature of about 22 K, mean column density of 1.7 $\\times10^{22}$ cm$^{-2}$, mean volume density of about 4.4 $\\times10^{4}$ cm$^{-3}$, and a mean mass of 320 $M_{\\odot}$. In addition, from PAH emission seen at 8 $\\mu$m, ...

  10. Radio observations of Supernova Remnants and the surrounding molecular gas

    CERN Document Server

    Dubner, G

    2011-01-01

    Supernova Remnants (SNRs) are believed to be the main source of Galactic cosmic rays (CR). The strong SNR shocks provide ideal acceleration sites for particles of at least 10^14 eV/nucleon. Radio continuum studies of SNRs carried out with good sensitivity and high angular resolution convey information about three main aspects of the SNRs: morphology, polarization and spectrum. Based on this information it is possible to localize sites of higher compression and particle acceleration as well as the orientation and degree of order of the magnetic fields, and in some cases even its intensity. All this information, when complemented with the study of the distribution and kinematics of the surrounding interstellar gas, results in a very useful dataset to investigate the role of SNRs as cosmic ray accelerators. In this presentation, I analyze the radio observations of SNRs and surrounding molecular clouds, showing the contribution of these studies to the understanding of the role of SNRs as factories of CRs.

  11. Triggered Star Formation Surrounding Wolf-Rayet Star HD 211853

    Science.gov (United States)

    Liu, Tie; Wu, Yuefang; Zhang, Huawei; Qin, Sheng-Li

    2012-05-01

    The environment surrounding Wolf-Rayet (W-R) star HD 211853 is studied in molecular, infrared, as well as radio, and H I emission. The molecular ring consists of well-separated cores, which have a volume density of 103 cm-3 and kinematic temperature ~20 K. Most of the cores are under gravitational collapse due to external pressure from the surrounding ionized gas. From the spectral energy distribution modeling toward the young stellar objects, the sequential star formation is revealed on a large scale in space spreading from the W-R star to the molecular ring. A small-scale sequential star formation is revealed toward core "A," which harbors a very young star cluster. Triggered star formations are thus suggested. The presence of the photodissociation region, the fragmentation of the molecular ring, the collapse of the cores, and the large-scale sequential star formation indicate that the "collect and collapse" process functions in this region. The star-forming activities in core "A" seem to be affected by the "radiation-driven implosion" process.

  12. On the environment surrounding close-in exoplanets

    CERN Document Server

    Vidotto, A A; Jardine, M; Moutou, C; Donati, J -F

    2015-01-01

    Exoplanets in extremely close-in orbits are immersed in a local interplanetary medium (i.e., the stellar wind) much denser than the local conditions encountered around the solar system planets. The environment surrounding these exoplanets also differs in terms of dynamics (slower stellar winds, but higher Keplerian velocities) and ambient magnetic fields (likely higher for host stars more active than the Sun). Here, we quantitatively investigate the nature of the interplanetary media surrounding the hot Jupiters HD46375b, HD73256b, HD102195b, HD130322b, HD179949b. We simulate the three-dimensional winds of their host stars, in which we directly incorporate their observed surface magnetic fields. With that, we derive mass-loss rates (1.9 to 8.0 $\\times 10^{-13} M_{\\odot}$/yr) and the wind properties at the position of the hot-Jupiters' orbits (temperature, velocity, magnetic field intensity and pressure). We show that these exoplanets' orbits are super-magnetosonic, indicating that bow shocks are formed surrou...

  13. Triggered star formation surrounding Wolf-Rayet star HD 211853

    CERN Document Server

    Liu, Tie; Zhang, Huawei; Qin, Sheng-Li

    2012-01-01

    The environment surrounding Wolf-Rayet star HD 211853 is studied in molecular emission, infrared emission, as well as radio and HI emission. The molecular ring consists of well-separated cores, which have a volume density of 10$^{3}$ cm$^{-3}$ and kinematic temperature $\\sim$20 K. Most of the cores are under gravitational collapse due to external pressure from the surrounding ionized gas. From SED modeling towards the young stellar objects (YSOs), sequential star formation is revealed on a large scale in space spreading from the Wolf-Rayet star to the molecular ring. A small scale sequential star formation is revealed towards core A, which harbors a very young star cluster. Triggered star formations is thus suggested. The presence of PDR, the fragmentation of the molecular ring, the collapse of the cores, the large scale sequential star formation indicate the "Collect and Collapse" process functions in this region. The star forming activities in core A seem to be affected by the "Radiation-Driven Implosion" (...

  14. TRIGGERED STAR FORMATION SURROUNDING WOLF-RAYET STAR HD 211853

    Energy Technology Data Exchange (ETDEWEB)

    Liu Tie; Wu Yuefang; Zhang Huawei [Department of Astronomy, Peking University, 100871 Beijing (China); Qin Shengli, E-mail: liutiepku@gmail.com [I. Physikalisches Institut, Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Koeln (Germany)

    2012-05-20

    The environment surrounding Wolf-Rayet (W-R) star HD 211853 is studied in molecular, infrared, as well as radio, and H I emission. The molecular ring consists of well-separated cores, which have a volume density of 10{sup 3} cm{sup -3} and kinematic temperature {approx}20 K. Most of the cores are under gravitational collapse due to external pressure from the surrounding ionized gas. From the spectral energy distribution modeling toward the young stellar objects, the sequential star formation is revealed on a large scale in space spreading from the W-R star to the molecular ring. A small-scale sequential star formation is revealed toward core 'A', which harbors a very young star cluster. Triggered star formations are thus suggested. The presence of the photodissociation region, the fragmentation of the molecular ring, the collapse of the cores, and the large-scale sequential star formation indicate that the 'collect and collapse' process functions in this region. The star-forming activities in core 'A' seem to be affected by the 'radiation-driven implosion' process.

  15. Single molecule studies of molecular diffusion in cellular membranes: determining membrane structure.

    Science.gov (United States)

    Ritchie, Ken; Spector, Jeff

    Since the advent of single particle/molecule microscopies, researchers have applied these techniques to understanding the fluid membranes of cells. By observing diffusion of membrane proteins and lipids in live cell membranes of eukaryotic cells, it has been found that membranes contain a mosaic of fluid compartments. Such structure may be instrumental in understanding key characteristics of the membrane. Recent single molecule observations on prokaryotic cell membranes will also be discussed.

  16. Molecules in Magnetic Fields

    Science.gov (United States)

    Berdyugina, Svetlana

    2015-08-01

    Molecules probe cool matter in the Universe and various astrophysical objects. Their ability to sense magnetic fields provides new insights into magnetic properties of these objects. During the past fifteen years we have carried out a theoretical study of molecular magnetic effects such as the Zeeman, Paschen-Back and Hanle effects and their applications for inferring magnetic structures and spatial inhomogeneities on the Sun, cool stars, brown dwarfs, and exoplanets from molecular spectro-polarimetry (e.g., Berdyugina 2011). Here, we present an overview of this study and compare our theoretical predictions with recent laboratory measurements of magnetic properties of some molecules. We present also a new web-based tool to compute molecular magnetic effects and polarized spectra which is supported by the ERC Advanced Grant HotMol.

  17. Atoms, molecules & elements

    CERN Document Server

    Graybill, George

    2007-01-01

    Young scientists will be thrilled to explore the invisible world of atoms, molecules and elements. Our resource provides ready-to-use information and activities for remedial students using simplified language and vocabulary. Students will label each part of the atom, learn what compounds are, and explore the patterns in the periodic table of elements to find calcium (Ca), chlorine (Cl), and helium (He) through hands-on activities.

  18. Motions of elastic solids in fluids under vibration

    DEFF Research Database (Denmark)

    Sorokin, V. S.; Blekhman, I. I.; Thomsen, Jon Juel

    2010-01-01

    Motion of a rigid or deformable solid in a viscous incompressible fluid and corresponding fluid–solid interactions are considered. Different cases of applying high frequency vibrations to the solid or to the surrounding fluid are treated. Simple formulas for the mean velocity of the solid...... are derived, under the assumption that the regime of the fluid flow induced by its motion is turbulent and the fluid resistance force is nonlinearly dependent on its velocity. It is shown that vibrations of a fluid’s volume slow down the motion of a submerged solid. This effect is much pronounced in the case...... of a deformable solid (i.e., gas bubble) exposed to near-resonant excitation. The results are relevant to the theory of gravitational enrichment of raw materials, and also contribute to the theory of controlled locomotion of a body with an internal oscillator in continuous deformable (solid or fluid) media....

  19. VESUVIUS PENTALOGUE: Interdisciplinary Science for Disaster Resilience and Sustainability of Populations Surrounding Vesuvius

    Science.gov (United States)

    Dobran, F.

    2015-12-01

    VESUVIUS PENTALOGUE is an elaboration of VESUVIUS 2000 scientific initiative aimed at volcanic risk reduction in the Vesuvius area. Its 5 building blocks are: (1) The current strategy of volcanic risk management (massive deportation of population) is both problematic and unacceptable. (2) A continuing close habitation of the population with the volcano should be the crucial cultural point to be pursued. This can be accomplished through a redefinition of the danger zone around Summa-Vesuvius as follows: (a) An exclusion nucleus should be established that prohibits all future human settlements and discourage the existing ones; (b) A resilience belt, housing most of the current population, should be established; (c) A sustainable area should be established beyond the resilience belt, allowing for both sustainable practices and temporary resettlements of the "resilience belt" citizens. (3) The built environment construction codes for the population of the danger zone should be established by utilizing Plinian eruption scenarios, scenario-based seismic hazard assessment and zonation, (c) dynamic structural analyses, (d) global volcanic simulations modeling of thermo-fluid dynamic eruption processes. (4) The volcanic risk information and education should involve an effective volcanic risk information campaign and active public preparedness strategy. This should be implemented for the exclusion nucleus, resilience belt, and sustainable area regions surrounding Summa-Vesuvius. A Volcanic Risk Education Safety Program should be implemented in all schools located within each of the above areas surrounding the volcano. (5)The political Authorities and the scientific community should produce a "memorandum of understanding" that univocally establishes an effective collaboration, and periodic progress reports that keep the populations informed on the improvements leading to the realization of the above objectives. For further details see www.gvess.org.

  20. Model molecules mimicking asphaltenes.

    Science.gov (United States)

    Sjöblom, Johan; Simon, Sébastien; Xu, Zhenghe

    2015-04-01

    Asphalthenes are typically defined as the fraction of petroleum insoluble in n-alkanes (typically heptane, but also hexane or pentane) but soluble in toluene. This fraction causes problems of emulsion formation and deposition/precipitation during crude oil production, processing and transport. From the definition it follows that asphaltenes are not a homogeneous fraction but is composed of molecules polydisperse in molecular weight, structure and functionalities. Their complexity makes the understanding of their properties difficult. Proper model molecules with well-defined structures which can resemble the properties of real asphaltenes can help to improve this understanding. Over the last ten years different research groups have proposed different asphaltene model molecules and studied them to determine how well they can mimic the properties of asphaltenes and determine the mechanisms behind the properties of asphaltenes. This article reviews the properties of the different classes of model compounds proposed and present their properties by comparison with fractionated asphaltenes. After presenting the interest of developing model asphaltenes, the composition and properties of asphaltenes are presented, followed by the presentation of approaches and accomplishments of different schools working on asphaltene model compounds. The presentation of bulk and interfacial properties of perylene-based model asphaltene compounds developed by Sjöblom et al. is the subject of the next part. Finally the emulsion-stabilization properties of fractionated asphaltenes and model asphaltene compounds is presented and discussed.

  1. Hydrogen molecules in semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Joerg [Technische Universitaet Dresden, 01062 Dresden (Germany)], E-mail: joerg.weber@tu-dresden.de; Hiller, Martin; Lavrov, Edward V. [Technische Universitaet Dresden, 01062 Dresden (Germany)

    2007-12-15

    Molecular hydrogen, the simplest of all molecules, allows a direct insight into the fundamental properties of quantum mechanics. In the case of H{sub 2}, the Pauli principle leads to two different species, para-H{sub 2} and ortho-H{sub 2}. A conversion between these species is prohibited. Vibrational mode spectra reflect the fundamental properties and allow an unambiguous identification of the H{sub 2} molecules. Today, we have experimental evidence for the trapping of hydrogen molecules in the semiconductors Si, Ge and GaAs at the interstitial sites, within hydrogen-induced platelets, in voids and at impurities (interstitial oxygen in Si). Interstitial H{sub 2} is a nearly free rotor with a surprisingly simple behavior. We review on interstitial H{sub 2} in semiconductors and report on the unexpected preferential disappearance of the para-H{sub 2} or ortho-D{sub 2} species. The origin of the detected ortho-para conversion will be discussed.

  2. Photonic Molecule Lasers Revisited

    Science.gov (United States)

    Gagnon, Denis; Dumont, Joey; Déziel, Jean-Luc; Dubé, Louis J.

    2014-05-01

    Photonic molecules (PMs) formed by coupling two or more optical resonators are ideal candidates for the fabrication of integrated microlasers, photonic molecule lasers. Whereas most calculations on PM lasers have been based on cold-cavity (passive) modes, i.e. quasi-bound states, a recently formulated steady-state ab initio laser theory (SALT) offers the possibility to take into account the spectral properties of the underlying gain transition, its position and linewidth, as well as incorporating an arbitrary pump profile. We will combine two theoretical approaches to characterize the lasing properties of PM lasers: for two-dimensional systems, the generalized Lorenz-Mie theory will obtain the resonant modes of the coupled molecules in an active medium described by SALT. Not only is then the theoretical description more complete, the use of an active medium provides additional parameters to control, engineer and harness the lasing properties of PM lasers for ultra-low threshold and directional single-mode emission. We will extend our recent study and present new results for a number of promising geometries. The authors acknowledge financial support from NSERC (Canada) and the CERC in Photonic Innovations of Y. Messaddeq.

  3. Biophysical investigations of the structure and function of the tear fluid lipid layer and the effect of ectoine. Part A: natural meibomian lipid films.

    Science.gov (United States)

    Dwivedi, Mridula; Backers, Hannes; Harishchandra, Rakesh Kumar; Galla, Hans-Joachim

    2014-10-01

    The tear fluid lipid layer is the outermost part of the tear film on the ocular surface which protects the eye from inflammations and injuries. We investigated the influence of ectoine on the structural organization of natural meibomian lipid films using surface activity analysis and topographical studies. These films exhibit a continuous pressure-area isotherm without any phase transition. With the addition of ectoine, the isotherm is expanded towards higher area per molecule values suggesting an increased area occupied by the interfacial lipid molecules. The AFM topology scans of natural meibomian lipid films reveal a presence of fiber-like structures. The addition of ectoine causes an appearance of droplet-like structures which are hypothesized to be tri-acyl-glycerols and other hydrophobic components excluded from the lipid film. Further the material properties of the droplet-like structure with respect to the surrounding were determined by using the quantitative imaging mode of the AFM technique. The droplet-like structures were found to be comparatively softer than the surrounding. Based on the observations a preliminary hypothesis is proposed explaining the mechanism of action of ectoine leading to the fluidization of meibomian lipid films. This suggests the possibility of ectoine as a treatment for the dry eye syndrome.

  4. Fluid and particle mechanics

    CERN Document Server

    Michell, S J

    2013-01-01

    Fluid and Particle Mechanics provides information pertinent to hydraulics or fluid mechanics. This book discusses the properties and behavior of liquids and gases in motion and at rest. Organized into nine chapters, this book begins with an overview of the science of fluid mechanics that is subdivided accordingly into two main branches, namely, fluid statics and fluid dynamics. This text then examines the flowmeter devices used for the measurement of flow of liquids and gases. Other chapters consider the principle of resistance in open channel flow, which is based on improper application of th

  5. Fluid cooled electrical assembly

    Science.gov (United States)

    Rinehart, Lawrence E.; Romero, Guillermo L.

    2007-02-06

    A heat producing, fluid cooled assembly that includes a housing made of liquid-impermeable material, which defines a fluid inlet and a fluid outlet and an opening. Also included is an electrical package having a set of semiconductor electrical devices supported on a substrate and the second major surface is a heat sink adapted to express heat generated from the electrical apparatus and wherein the second major surface defines a rim that is fit to the opening. Further, the housing is constructed so that as fluid travels from the fluid inlet to the fluid outlet it is constrained to flow past the opening thereby placing the fluid in contact with the heat sink.

  6. Spinning fluids reactor

    Science.gov (United States)

    Miller, Jan D; Hupka, Jan; Aranowski, Robert

    2012-11-20

    A spinning fluids reactor, includes a reactor body (24) having a circular cross-section and a fluid contactor screen (26) within the reactor body (24). The fluid contactor screen (26) having a plurality of apertures and a circular cross-section concentric with the reactor body (24) for a length thus forming an inner volume (28) bound by the fluid contactor screen (26) and an outer volume (30) bound by the reactor body (24) and the fluid contactor screen (26). A primary inlet (20) can be operatively connected to the reactor body (24) and can be configured to produce flow-through first spinning flow of a first fluid within the inner volume (28). A secondary inlet (22) can similarly be operatively connected to the reactor body (24) and can be configured to produce a second flow of a second fluid within the outer volume (30) which is optionally spinning.

  7. An analysis of amino acid sequences surrounding archaeal glycoprotein sequons.

    Science.gov (United States)

    Abu-Qarn, Mehtap; Eichler, Jerry

    2007-05-01

    Despite having provided the first example of a prokaryal glycoprotein, little is known of the rules governing the N-glycosylation process in Archaea. As in Eukarya and Bacteria, archaeal N-glycosylation takes place at the Asn residues of Asn-X-Ser/Thr sequons. Since not all sequons are utilized, it is clear that other factors, including the context in which a sequon exists, affect glycosylation efficiency. As yet, the contribution to N-glycosylation made by sequon-bordering residues and other related factors in Archaea remains unaddressed. In the following, the surroundings of Asn residues confirmed by experiment as modified were analyzed in an attempt to define sequence rules and requirements for archaeal N-glycosylation.

  8. An analysis of amino acid sequences surrounding archaeal glycoprotein sequons

    Directory of Open Access Journals (Sweden)

    Mehtap Abu-Qarn

    2006-01-01

    Full Text Available Despite having provided the first example of a prokaryal glycoprotein, little is known of the rules governing the N-glycosylation process in Archaea. As in Eukarya and Bacteria, archaeal N-glycosylation takes place at the Asn residues of Asn-X-Ser/Thr sequons. Since not all sequons are utilized, it is clear that other factors, including the context in which a sequon exists, affect glycosylation efficiency. As yet, the contribution to N-glycosylation made by sequon-bordering residues and other related factors in Archaea remains unaddressed. In the following, the surroundings of Asn residues confirmed by experiment as modified were analyzed in an attempt to define sequence rules and requirements for archaeal N-glycosylation.

  9. Wave rectification in plasma sheaths surrounding electric field antennas

    Science.gov (United States)

    Boehm, M. H.; Carlson, C. W.; Mcfadden, J. P.; Clemmons, J. H.; Ergun, R. E.; Mozer, F. S.

    1994-01-01

    Combined measurements of Langmuir or broadband whistler wave intensity and lower-frequency electric field waveforms, all at 10-microsecond time resolution, were made on several recent sounding rockets in the auroral ionosphere. It is found that Langmuir and whistler waves are partically rectified in the plasma sheaths surrounding the payload and the spheres used as antennas. This sheath rectification occurs whenever the high frequency (HF) potential across the sheath becomes of the same order as the electron temperature or higher, for wave frequencies near or above the ion plasma frequency. This rectification can introduce false low-frequency waves into measurements of electric field spectra when strong high-frequency waves are present. Second harmonic signals are also generated, although at much lower levels. The effect occurs in many different plasma conditions, primarily producing false waves at frequencies that are low enough for the antenna coupling to the plasma to be resistive.

  10. The nature of plerions surrounding soft gamma-ray repeaters

    CERN Document Server

    Harding, A K

    1995-01-01

    Compact steady sources of X-ray emission have been detected at the positions of at least two soft gamma-ray repeaters (SGRs). These sources have been interpreted as synchrotron nebulae powered by the neutron star that is causing the bursts. We explore a plerion model for the sources surrounding SGRs where the steady observed emission is powered by the SGR bursts rather than by the spin-down of a pulsar. In this case there is no limit on the neutron star magnetic field. We find that the synchrotron lifetime of the particles injected into the plerion around SGR1806-20 is long enough to smear out nebular emission from individual bursts. Transient nebular emission would therefore not be detected following an SGR burst. The combined radio emission from multiple burst injections is expected to have a steeper spectrum than that of a typical plerion.

  11. Casimir Effect in the Kerr Spacetime Surrounded by Quintessence

    CERN Document Server

    Bezerra, V B; Freitas, L F F; Muniz, C R

    2016-01-01

    We calculate the Casimir energy of a massless scalar field in a cavity formed by nearby parallel plates orbiting a rotating spherical body surrounded by quintessence, investigating the influence of the gravitational field on that energy, at zero temperature. This influence includes the effects due to the spacetime dragging caused by the source rotation as well as those ones due to the quintessence. We show that the energy depends on all the involved parameters, as source mass, angular momentum and quintessence state parameter, for any radial coordinate and polar angle. We show that at the north pole the Casimir energy is not influenced by the quintessential matter. At the equatorial plane, when the quintessence is canceled, the result obtained in the literature is recovered. Finally, constraints in the quintessence parameters are obtained from the uncertainty in the current measurements of Casimir effect.

  12. Ozone bioindication in Barcelona and surrounding area of Catalonia

    Energy Technology Data Exchange (ETDEWEB)

    Ribas, A.; Penuelas, J. [Univ. Autonoma de Barcelona, Barcelona (Spain). Ecophysiology Unit of CSIC

    2002-07-01

    A field study was conducted from July to September 2000 to assess ozone (O{sub 3}) phytotoxicity in Barcelona and surrounding areas of Catalonia (NE Spain) by using tobacco plants Bel-W3 and Populus nigra 'Brandaris' as bioindicators. The study was conducted simultaneously at eight sites where ozone concentrations and meteorological variables were continuously monitored. The ozone levels correlated well with ozone injury on the Bel-W3 cultivar, especially at stations established in the urban area of Barcelona, and in the first months of summer. In the second half of summer plants showed a decreasing efficiency in its biomonitoring capacity. The behaviour of Populus as bioindicator or biomonitor was less satisfactory. For both species it is necessary to improve cultivation conditions since water deficits seem to play an important role in bioindication in the Mediterranean region. (orig.)

  13. Physical Coupling of Kazarian Galaxies with Surrounding Galaxies

    Science.gov (United States)

    Kazarian, M. A.; Martirosian, J. R.

    2003-04-01

    Results from a statistical study of Kazarian galaxies and the objects surrounding them are presented. It is shown that: (1) the sample of Kazarian galaxies up to 16m.0 is complete. (2) Roughly 35.7% of the Kazarian galaxies are members of clusters, 14.0% of groups, and 13.6% of binary systems, while 36.7% are single galaxies. (3) Of the 580 Kazarian galaxies, roughly 61.2% are infrared, 8.8% radio, and 2.8% x-ray sources. (4) The relative numbers of Kazarian galaxies for complete samples of I, R, and X in the different groups are systematically higher than the corresponding numbers for samples of all Kazarian galaxies.

  14. On radial oscillations in viscous accretion discs surrounding neutron stars

    Science.gov (United States)

    Chen, Xingming; Taam, Ronald E.

    1992-01-01

    Radial oscillations resulting from axisymmetric perturbations in viscous accretion disks surrounding neutron stars in X-ray binary systems have been investigated. Within the framework of the alpha-viscosity model a series of hydrodynamic calculations demonstrates that the oscillations are global for alpha of about 1. On the other hand, for alpha of 0.4 or less, the oscillations are local and confined to the disk boundaries. If viscous stresses acting in the radial direction are included, however, it is found that the disk can be stabilized. The application of such instabilities in accretion disks, without reference to the boundary layer region between the neutron star (or magnetosphere) and the inner edge of the disk, to the phenomenology of quasi-periodic oscillations is brought into question.

  15. Natural convection between a vertical cylinder and a surrounding array

    Energy Technology Data Exchange (ETDEWEB)

    McEligot, D.M.; O`Brien, J.E.; Stoots, C.M.; Larson, T.K.; Christenson, W.A.; Mecham, D.C.; Lussie, W.G.

    1992-09-01

    The generic situation considered is natural convection between a single heated, vertical cylinder and a surrounding array of cooler vertical cylinders in a triangular pattern. The ratio of the test section temperature to the cooling tube temperature was varied up to 2.6 by adjusting the electrical power. The Rayleigh number, based on test section diameter and air properties evaluated at cooling tube temperature, ranged from 2.9 x 10{sup 4} to 4.6 x 10{sup 5}. Results indicate that the convective heat transfer data could be approximated as Nu{sub D} (T{sub ts}/T{sub ct}){sup 0.14} = 0.156 Ra{sub D}{sup 1/3} in the apparent turbulent region for Ra{sub L} > 1.2 x 10{sup 11.}

  16. Natural convection between a vertical cylinder and a surrounding array

    Energy Technology Data Exchange (ETDEWEB)

    McEligot, D.M.; O' Brien, J.E.; Stoots, C.M.; Larson, T.K.; Christenson, W.A.; Mecham, D.C.; Lussie, W.G.

    1992-01-01

    The generic situation considered is natural convection between a single heated, vertical cylinder and a surrounding array of cooler vertical cylinders in a triangular pattern. The ratio of the test section temperature to the cooling tube temperature was varied up to 2.6 by adjusting the electrical power. The Rayleigh number, based on test section diameter and air properties evaluated at cooling tube temperature, ranged from 2.9 x 10{sup 4} to 4.6 x 10{sup 5}. Results indicate that the convective heat transfer data could be approximated as Nu{sub D} (T{sub ts}/T{sub ct}){sup 0.14} = 0.156 Ra{sub D}{sup 1/3} in the apparent turbulent region for Ra{sub L} > 1.2 x 10{sup 11.}

  17. Rotation of the Warm Molecular Gas Surrounding Ultracompact HII Regions

    CERN Document Server

    Klaassen, P D; Keto, E R; Zhang, Q

    2009-01-01

    We present molecular line and 1.4 mm continuum observations towards five massive star forming regions at arcsecond resolution using the Submillimeter Array (SMA). We find that the warm molecular gas surrounding each HII region (as traced by SO_2 and OCS) appears to be undergoing bulk rotation. From the molecular line emission and thermal component of the continuum emission, we independently derived gas masses for each region which are consistent with each other. From the free-free component of the continuum emission we estimate the minimum stellar mass required to power the HII region and find that this mass, when added to the derived gas mass, is a significant fraction of the dynamical mass for that region.

  18. A 500 Parsec Halo Surrounding the Galactic Globular NGC 1851

    CERN Document Server

    Olszewski, Edward W; Knezek, Patricia; Subramaniam, Annapurni; de Boer, Thomas; Seitzer, Patrick

    2009-01-01

    Using imaging that shows four magnitudes of main sequence stars, we have discovered that the Galactic globular cluster NGC 1851 is surrounded by a halo that is visible from the tidal radius of 700 arcsec (41 pc) to more than 4500 arcsec (>250 pc). This halo is symmetric and falls in density as a power law of $r^{-1.24}$. It contains approximately 0.1% of the dynamical mass of NGC 1851. There is no evidence for tidal tails. Current models of globular cluster evolution do not explain this feature, although simulations of tidal influences on dwarf spheroidal galaxies qualitatively mimic these results. Given the state of published models it is not possible to decide between creation of this halo from isolated cluster evaporation, or from tidal or disk shocking, or from destruction of a dwarf galaxy in which this object may have once been embedded.

  19. Thermodynamic stability of black holes surrounded by quintessence

    CERN Document Server

    Ma, Meng-Sen; Ma, Ya-Qin

    2016-01-01

    We study the thermodynamic stabilities of uncharged and charged black holes surrounded by quintessence (BHQ) by means of effective thermodynamic quantities. When the state parameter of quintessence $\\omega_q$ is appropriately chosen, the structures of BHQ are something like that of black holes in de Sitter space. Constructing the effective first law of thermodynamics in two different ways, we can derive the effective thermodynamic quantities of BHQ. Especially, these effective thermodynamic quantities also satisfy Smarr-like formulae. It is found that the uncharged BHQ is always thermodynamically unstable due to negative heat capacity, while for the charged BHQ there are phase transitions of the second order. We also show that there is a great deal of difference on the thermodynamic properties and critical behaviors of BHQ between the two ways we employed.

  20. Thermodynamic stability of black holes surrounded by quintessence

    Science.gov (United States)

    Ma, Meng-Sen; Zhao, Ren; Ma, Ya-Qin

    2017-06-01

    We study the thermodynamic stabilities of uncharged and charged black holes surrounded by quintessence (BHQ) by means of effective thermodynamic quantities. When the state parameter of quintessence ω _q is appropriately chosen, the structures of BHQ are something like that of black holes in de Sitter space. Constructing the effective first law of thermodynamics in two different ways, we can derive the effective thermodynamic quantities of BHQ. Especially, these effective thermodynamic quantities also satisfy Smarr-like formulae. It is found that the uncharged BHQ is always thermodynamically unstable due to negative heat capacity, while for the charged BHQ there are phase transitions of the second order. We also show that there are several differences on the thermodynamic properties and critical behaviors of BHQ between the two ways we employed.

  1. Impact-Generated Dust Clouds Surrounding the Galilean Moons

    CERN Document Server

    Krüger, H; Grün, E; Kr\\"uger, Harald~; Krivov, Alexander V.; Gr\\"un, Eberhard

    2003-01-01

    Tenuous dust clouds of Jupiter's Galilean moons Io, Europa, Ganymede and Callisto have been detected with the in-situ dust detector on board the Galileo spacecraft. The majority of the dust particles have been sensed at altitudes below five radii of these lunar-sized satellites. We identify the particles in the dust clouds surrounding the moons by their impact direction, impact velocity, and mass distribution. Average particle sizes are 0.5 to $\\rm 1 \\mu m$, just above the detector threshold, indicating a size distribution with decreasing numbers towards bigger particles. Our results imply that the particles have been kicked up by hypervelocity impacts of micrometeoroids onto the satellites' surfaces. The measured radial dust density profiles are consistent with predictions by dynamical modeling for satellite ejecta produced by interplanetary impactors (Krivov et al., PSS, 2003, 51, 251--269), assuming yield, mass and velocity distributions of the ejecta from laboratory measurements. The dust clouds of the th...

  2. Self-gravitating fluid tori with charge

    Science.gov (United States)

    Karas, Vladimir; Trova, Audrey; Kovar, Jiri

    2017-08-01

    We have been developing an analytical approach to study equilibria of self-gravitating charged fluid embedded in the gravitational and magnetic fields of a central body. Our calculations provide a toy-model scenario for gaseous/dusty tori surrounding supermassive black holes in galactic nuclei. While the central black hole dominates the gravitational field and remains electrically neutral, the surrounding material has a non-negligible self-gravitational effect on the torus structure. Moreover, by charging mechanisms it also acquires non-zero electric charge density. These two influences need to be taken into account to achieve a self-consistent picture (based on Trova et al., ApJSS, 226, id. 12, 2016).

  3. The role of pressurized fluid in subchondral bone cyst growth.

    Science.gov (United States)

    Cox, L G E; Lagemaat, M W; van Donkelaar, C C; van Rietbergen, B; Reilingh, M L; Blankevoort, L; van Dijk, C N; Ito, K

    2011-10-01

    Pressurized fluid has been proposed to play an important role in subchondral bone cyst development. However, the exact mechanism remains speculative. We used an established computational mechanoregulated bone adaptation model to investigate two hypotheses: 1) pressurized fluid causes cyst growth through altered bone tissue loading conditions, 2) pressurized fluid causes cyst growth through osteocyte death. In a 2D finite element model of bone microarchitecture, a marrow cavity was filled with fluid to resemble a cyst. Subsequently, the fluid was pressurized, or osteocyte death was simulated, or both. Rather than increasing the load, which was the prevailing hypothesis, pressurized fluid decreased the load on the surrounding bone, thereby leading to net bone resorption and growth of the cavity. In this scenario an irregularly shaped cavity developed which became rounded and obtained a rim of sclerotic bone after removal of the pressurized fluid. This indicates that cyst development may occur in a step-wise manner. In the simulations of osteocyte death, cavity growth also occurred, and the cavity immediately obtained a rounded shape and a sclerotic rim. Combining both mechanisms increased the growth rate of the cavity. In conclusion, both stress-shielding by pressurized fluid, and osteocyte death may cause cyst growth. In vivo observations of pressurized cyst fluid, dead osteocytes, and different appearances of cysts similar to our simulation results support the idea that both mechanisms can simultaneously play a role in the development and growth of subchondral bone cysts. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Inhibition of adipocyte differentiation by resistin-like molecule alpha. Biochemical characterization of its oligomeric nature

    DEFF Research Database (Denmark)

    Blagoev, Blagoy; Kratchmarova, Irina; Nielsen, Mogens M

    2002-01-01

    of thiazolidinediones. The prototypical member of this family was originally identified from bronchoalveolar lavage fluid of inflamed lungs and designated FIZZ1 ("found in inflammatory zone"). This molecule was also found to be highly expressed in adipose tissue and was named resistin-like molecule alpha (RELMalpha...

  5. Thermodynamics phase changes of nanopore fluids

    KAUST Repository

    Islam, Akand W.

    2015-07-01

    The van der Waals (vdW) equation (Eq.) is modified to describe thermodynamic of phase behavior of fluids confined in nanopore. Our aim is to compute pressures exerted by the fluid molecules and to investigate how they change due to pore proximity by assuming the pore wall is inert. No additional scaling of model parameters is imposed and original volume and energy parameters are used in the calculations. Our results clearly show the phase changes due to confinement. The critical shifts of temperatures and pressures are in good agreement compared to the laboratory data and molecular simulation. Peng-Robinson (PR) equation-of-state (EOS) has resulted in different effect than the vdW. This work delivers insights into the nature of fluid behavior in extremely low-permeability nanoporous media, especially in the tight shale reservoirs, below the critical temperatures. © 2015 Elsevier B.V.

  6. Molecules in crystals

    Science.gov (United States)

    Spackman, Mark A.

    2013-04-01

    Hirshfeld surface analysis has developed from the serendipitous discovery of a novel partitioning of the crystal electron density into discrete molecular fragments, to a suite of computational tools used widely for the identification, analysis and discussion of intermolecular interactions in molecular crystals. The relationship between the Hirshfeld surface and very early ideas on the internal structure of crystals is outlined, and applications of Hirshfeld surface analysis are presented for three molecules of historical importance in the development of modern x-ray crystallography: hexamethylbenzene, hexamethylenetetramine and diketopiperazine.

  7. Raman scattering mediated by neighboring molecules.

    Science.gov (United States)

    Williams, Mathew D; Bradshaw, David S; Andrews, David L

    2016-05-01

    Raman scattering is most commonly associated with a change in vibrational state within individual molecules, the corresponding frequency shift in the scattered light affording a key way of identifying material structures. In theories where both matter and light are treated quantum mechanically, the fundamental scattering process is represented as the concurrent annihilation of a photon from one radiation mode and creation of another in a different mode. Developing this quantum electrodynamical formulation, the focus of the present work is on the spectroscopic consequences of electrodynamic coupling between neighboring molecules or other kinds of optical center. To encompass these nanoscale interactions, through which the molecular states evolve under the dual influence of the input light and local fields, this work identifies and determines two major mechanisms for each of which different selection rules apply. The constituent optical centers are considered to be chemically different and held in a fixed orientation with respect to each other, either as two components of a larger molecule or a molecular assembly that can undergo free rotation in a fluid medium or as parts of a larger, solid material. The two centers are considered to be separated beyond wavefunction overlap but close enough together to fall within an optical near-field limit, which leads to high inverse power dependences on their local separation. In this investigation, individual centers undergo a Stokes transition, whilst each neighbor of a different species remains in its original electronic and vibrational state. Analogous principles are applicable for the anti-Stokes case. The analysis concludes by considering the experimental consequences of applying this spectroscopic interpretation to fluid media; explicitly, the selection rules and the impact of pressure on the radiant intensity of this process.

  8. Simple bond length dependence: A correspondence between reactive fluid theories

    Science.gov (United States)

    Dyer, Kippi M.; Perkyns, John S.; Pettitt, B. M.

    2005-06-01

    Two elementary models of reactive fluids are examined, the first being a standard construction assuming molecular dissociation at infinite separation; the second is an open mixture of nondissociative molecules and free atoms in which the densities of free atoms and molecules are coupled. An approximation to the density of molecules, to low order in site density, is derived in terms of the classical associating fluid theory variously described by Wertheim [J. Chem. Phys. 87, 7323 (1987)] and Stell [Physica A 231, 1 (1996)]. The results are derived for a fluid of dimerizing hard spheres, and predict dependence of the molecular density on the total site density, the hard sphere diameter, and the bond length of the dimer. The results for the two reactive models are shown to be qualitatively similar, and lead to equivalent predictions of the molecular density for the infinitely short and infinitely long bond lengths.

  9. The effects of bio-fluid on the internal motion of DNA

    CERN Document Server

    Sulaiman, A; 10.1166/jctn.2011.1669

    2011-01-01

    The internal motions of DNA immersed in bio-fluid are investigated. The interactions between the fragments of DNA and the surrounding bio-fluid are modeled using the gauge fluid lagrangian. In the model, the bio-fluid is coupled to the standard gauge invariant bosonic lagrangian describing the DNA. It is shown that at non-relativistic limit various equation of motions, from the well-known Sine-Gordon equation to the simultaneous nonlinear equations, can be constructed within a single framework. The effects of bio-fluid are investigated for two cases : single and double stranded DNA. It is argued that the small and large amplitudes of a single stranded DNA motion immersed in bio-fluid can be explained in a natural way within the model as a solitonic wave regardless with the fluid velocity. In contrary the double stranded DNA behaves as regular or damped harmonic oscillator and is highly depending on the fluid velocity.

  10. Ultra-cold molecule production.

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez-Serrano, Jamie; Chandler, David W.; Strecker, Kevin; Rahn, Larry A.

    2005-12-01

    The production of Ultra-cold molecules is a goal of many laboratories through out the world. Here we are pursuing a unique technique that utilizes the kinematics of atomic and molecular collisions to achieve the goal of producing substantial numbers of sub Kelvin molecules confined in a trap. Here a trap is defined as an apparatus that spatially localizes, in a known location in the laboratory, a sample of molecules whose temperature is below one degree absolute Kelvin. Further, the storage time for the molecules must be sufficient to measure and possibly further cool the molecules. We utilize a technique unique to Sandia to form cold molecules from near mass degenerate collisions between atoms and molecules. This report describes the progress we have made using this novel technique and the further progress towards trapping molecules we have cooled.

  11. Seismicity and faulting attributable to fluid extraction

    Science.gov (United States)

    Yerkes, R.F.; Castle, R.O.

    1976-01-01

    The association between fluid injection and seismicity has been well documented and widely publicized. Less well known, but probably equally widespread are faulting and shallow seismicity attributable solely to fluid extraction, particularly in association with petroleum production. Two unequivocable examples of seismicity and faulting associated with fluid extraction in the United States are: The Goose Creek, Texas oil field event of 1925 (involving surface rupture); and the Wilmington, California oil field events (involving subsurface rupture) of 1947, 1949, 1951 (2), 1955, and 1961. Six additional cases of intensity I-VII earthquakes (M oil and gas fields. In addition to these examples are thirteen cases of apparently aseismic surface rupture associated with production from California and Texas oil fields. Small earthquakes in the Eloy-Picacho area of Arizona may be attributable to withdrawal of groundwater, but their relation to widespread fissuring is enigmatic. The clearest example of extraction-induced seismicity outside of North America is the 1951 series of earthquakes associated with gas production from the Po River delta near Caviga, Italy. Faulting and seismicity associated with fluid extraction are attributed to differential compaction at depth caused by reduction of reservoir fluid pressure and attendant increase in effective stress. Surface and subsurface measurements and theoretical and model studies show that differential compaction leads not only to differential subsidence and centripetally-directed horizontal displacements, but to changes in both vertical- and horizontal-strain regimes. Study of well-documented examples indicates that the occurrence and nature of faulting and seismicity associated with compaction are functions chiefly of: (1) the pre-exploitation strain regime, and (2) the magnitude of contractional horizontal strain centered over the compacting materials relative to that of the surrounding annulus of extensional horizontal

  12. High sensitivity fluorescent single particle and single molecule detection apparatus and method

    Energy Technology Data Exchange (ETDEWEB)

    Mathies, Richard A. (Contra Costa County, CA); Peck, Konan (Contra Costa County, CA); Stryer, Lubert (Santa Clara County, CA)

    1990-01-01

    Apparatus is described for ultrasensitive detection of single fluorescent particles down to the single fluorescent molecule limit in a fluid or on a substrate comprising means for illuminating a predetermined volume of the fluid or area of the substrate whereby to emit light including background light from the fluid and burst of photons from particles residing in the area. The photon burst is detected in real time to generate output representative signal. The signal is received and the burst of energy from the fluorescent particles is distinguished from the background energy to provide an indication of the number, location or concentration of the particles or molecules.

  13. Fluorescence Polarization Assays in Small Molecule Screening

    Science.gov (United States)

    Lea, Wendy A.; Simeonov, Anton

    2011-01-01

    Importance of the field Fluorescence polarization (FP) is a homogeneous method that allows rapid and quantitative analysis of diverse molecular interactions and enzyme activities. This technique has been widely utilized in clinical and biomedical settings, including the diagnosis of certain diseases and monitoring therapeutic drug levels in body fluids. Recent developments in the field has been symbolized by the facile adoption of FP in high-throughput screening (HTS) and small molecule drug discovery of an increasing range of target classes. Areas covered in this review The article provides a brief overview on the theoretical foundation of FP, followed by updates on recent advancements in its application for various drug target classes, including G-protein coupled receptors (GPCRs), enzymes and protein-protein interactions (PPIs). The strengths and weaknesses of this method, practical considerations in assay design, novel applications, and future directions are also discussed. What the reader will gain The reader will be informed of the most recent advancements and future directions of FP application to small molecule screening. Take home message In addition to its continued utilization in high-throughput screening, FP has expanded into new disease and target areas and has been marked by increased use of labeled small molecule ligands for receptor binding studies. PMID:22328899

  14. Tomography images of the Alpine roots and surrounding upper mantle

    Science.gov (United States)

    Plomerova, Jaroslava; Babuska, Vladislav

    2017-04-01

    Teleseismic body-wave tomography represents powerful tool to study regional velocity structure of the upper mantle and to image velocity anomalies, such as subducted lithosphere plates in collisional zones. In this contribution, we recapitulate 3D models of the upper mantle beneath the Alps, which developed at a collision zone of the Eurasian and African plates. Seismic tomography studies indicate a leading role of the rigid mantle lithosphere that functioned as a major stress guide during the plate collisions. Interactions of the European lithosphere with several micro-plates in the south resulted in an arcuate shape of this mountain range on the surface and in a complicated geometry of the Alpine subductions in the mantle. Early models with one bended lithosphere root have been replaced with more advanced models showing two separate lithosphere roots beneath the Western and Eastern Alps (Babuska et al., Tectonophysics 1990; Lippitsch et al., JGR 2003). The standard isotropic velocity tomography, based on pre-AlpArray data (the currently performed passive seismic experiment in the Alps and surroundings) images the south-eastward dipping curved slab of the Eurasian lithosphere in the Western Alps. On the contrary, beneath the Eastern Alps the results indicate a very steep northward dipping root that resulted from the collision of the European plate with the Adriatic microplate. Dando et al. (2011) interpret high-velocity heterogeneities at the bottom of their regional tomographic model as a graveyard of old subducted lithospheres. High density of stations, large amount of rays and dense ray-coverage of the volume studied are not the only essential pre-requisites for reliable tomography results. A compromise between the amount of pre-processed data and the high-quality of the tomography input (travel-time residuals) is of the high importance as well. For the first time, the existence of two separate roots beneath the Alps has been revealed from carefully pre

  15. The water exchange between Chinchorro Bank and its surroundings

    Science.gov (United States)

    Candela, Julio; Ochoa, Jose Luis; Sheinbaum, Julio; Lopez, Manuel; Cornado, Cesar

    2015-04-01

    Chinchorro Bank is a relatively large (~500 km^ 2) atoll situated 33 km in front of the Yucatan Peninsula in the Caribbean coast of Mexico. Two years of continuous measurements of the subsurface pressure field inside and around Chinchorro Bank, along with currents and waves observed outside, suggest four major processes governing the water exchange of the Bank with its surroundings: 1) surface wave pumping of water into the Bank through its eastern edge, 2) the large scale circulation in the region that drives the sea level changes through geostrophy, 3) the tidal pumping with imposed cyclic flows into and out of the Bank and 4) the imposed drift by the wind. Waves impinging all along the eastern barrier reef induce water inflows (from overtopping the reef) and generate a pressure gradient that drives a drift from east to west throughout the Bank. This western drift can normally replenish the water over the Bank with a time scale of ~10 days. However, extreme wave events, lasting around 24 hours, can replenish the whole Bank's water in the order of day. The region's large scale circulation is dominated by the zonal Cayman Current impinging on the Yucatan Peninsula becoming the Yucatan Current as it turns northward. Variability in the strength and impacting latitude of this current causes sea level gradients within the Bank, i.e., a Yucatan Current increase of 1 m/s, over a period of a couple of weeks, sets up a zonal sea level gradient within that can replenish the whole Bank's water in a time scale of ~14 days. At such times, the large scale current around the Bank is at a maximum thus ensuring an effective removal and dispersal of the exported waters. The Bank has a micro-tidal regime with a semidiurnal amplitude of ~12 cm during spring tides and a diurnal of ~2 cm, these imply that the Bank is exchanging ~10% of its waters with its surroundings daily. However small, this tidal pumping is effective for the ventilation of the Banks' waters in ~10 days due to the

  16. μ-PIV measurements of the ensemble flow fields surrounding a migrating semi-infinite bubble.

    Science.gov (United States)

    Yamaguchi, Eiichiro; Smith, Bradford J; Gaver, Donald P

    2009-08-01

    Microscale particle image velocimetry (μ-PIV) measurements of ensemble flow fields surrounding a steadily-migrating semi-infinite bubble through the novel adaptation of a computer controlled linear motor flow control system. The system was programmed to generate a square wave velocity input in order to produce accurate constant bubble propagation repeatedly and effectively through a fused glass capillary tube. We present a novel technique for re-positioning of the coordinate axis to the bubble tip frame of reference in each instantaneous field through the analysis of the sudden change of standard deviation of centerline velocity profiles across the bubble interface. Ensemble averages were then computed in this bubble tip frame of reference. Combined fluid systems of water/air, glycerol/air, and glycerol/Si-oil were used to investigate flows comparable to computational simulations described in Smith and Gaver (2008) and to past experimental observations of interfacial shape. Fluorescent particle images were also analyzed to measure the residual film thickness trailing behind the bubble. The flow fields and film thickness agree very well with the computational simulations as well as existing experimental and analytical results. Particle accumulation and migration associated with the flow patterns near the bubble tip after long experimental durations are discussed as potential sources of error in the experimental method.

  17. Acoustoelastic effects of Stoneley waves in a borehole surrounded by a transversely isotropic elastic solid

    Directory of Open Access Journals (Sweden)

    Jinxia Liu

    2014-11-01

    Full Text Available Stoneley wave in a fluid-filled pressurized borehole surrounded by a transversely isotropic elastic solid with nine independent third-order elastic constants in presence of biaxial stresses are studied. A simplified acoustoelastic formulation of Stoneley wave is presented for the parallelism of the borehole axis and the formation axis of symmetry. Sensitivity coefficients and velocity dispersions for Stoneley wave due to the presence of stresses are numerically investigated, respectively. The acoustoelastic formulation explicitly shows that the velocity dispersions of Stoneley wave depend on seven independent third-order elastic constants in presence of biaxial stresses and on six independent third-order elastic constants in the presence of borehole pressurization alone. Numerical results of both sensitivity coefficients and velocity dispersions of Stoneley wave show that at low frequency the velocity change of Stoneley wave is sensitive to c111 and c112. Stoneley wave velocity at low frequencies can be simplified by 3 independent third order elastic constants (c111, c112 and c123 instead of nine constants. In presence of biaxial stresses, at low frequencies the speed of the Stoneley wave is similar to White’s formula.

  18. Metalworking and machining fluids

    Science.gov (United States)

    Erdemir, Ali; Sykora, Frank; Dorbeck, Mark

    2010-10-12

    Improved boron-based metal working and machining fluids. Boric acid and boron-based additives that, when mixed with certain carrier fluids, such as water, cellulose and/or cellulose derivatives, polyhydric alcohol, polyalkylene glycol, polyvinyl alcohol, starch, dextrin, in solid and/or solvated forms result in improved metalworking and machining of metallic work pieces. Fluids manufactured with boric acid or boron-based additives effectively reduce friction, prevent galling and severe wear problems on cutting and forming tools.

  19. Passing Current through Touching Molecules

    DEFF Research Database (Denmark)

    Schull, G.; Frederiksen, Thomas; Brandbyge, Mads

    2009-01-01

    The charge flow from a single C-60 molecule to another one has been probed. The conformation and electronic states of both molecules on the contacting electrodes have been characterized using a cryogenic scanning tunneling microscope. While the contact conductance of a single molecule between two...

  20. Molecules Best Paper Award 2013.

    Science.gov (United States)

    McPhee, Derek J

    2013-02-05

    Molecules has started to institute a "Best Paper" award to recognize the most outstanding papers in the area of natural products, medicinal chemistry and molecular diversity published in Molecules. We are pleased to announce the second "Molecules Best Paper Award" for 2013.

  1. The Fluids RAP

    Science.gov (United States)

    Nedyalkov, Ivaylo

    2016-11-01

    After fifteen years of experience in rap, and ten in fluid mechanics, "I am coming here with high-Reynolds-number stamina; I can beat these rap folks whose flows are... laminar." The rap relates fluid flows to rap flows. The fluid concepts presented in the song have varying complexity and the listeners/viewers will be encouraged to read the explanations on a site dedicated to the rap. The music video will provide an opportunity to share high-quality fluid visualizations with a general audience. This talk will present the rap lyrics, the vision for the video, and the strategy for outreach. Suggestions and comments will be welcomed.

  2. Theoretical Fluid Dynamics

    CERN Document Server

    Shivamoggi, Bhimsen K

    1998-01-01

    "Although there are many texts and monographs on fluid dynamics, I do not know of any which is as comprehensive as the present book. It surveys nearly the entire field of classical fluid dynamics in an advanced, compact, and clear manner, and discusses the various conceptual and analytical models of fluid flow." - Foundations of Physics on the first edition. Theoretical Fluid Dynamics functions equally well as a graduate-level text and a professional reference. Steering a middle course between the empiricism of engineering and the abstractions of pure mathematics, the author focuses

  3. Fluid dynamics transactions

    CERN Document Server

    Fiszdon, W

    1965-01-01

    Fluid Dynamics Transactions, Volume 2 compiles 46 papers on fluid dynamics, a subdiscipline of fluid mechanics that deals with fluid flow. The topics discussed in this book include developments in interference theory for aeronautical applications; diffusion from sources in a turbulent boundary layer; unsteady motion of a finite wing span in a compressible medium; and wall pressure covariance and comparison with experiment. The certain classes of non-stationary axially symmetric flows in magneto-gas-dynamics; description of the phenomenon of secondary flows in curved channels by means of co

  4. The structural feature surrounding glycated lysine residues in human hemoglobin.

    Science.gov (United States)

    Ito, Shigenori; Nakahari, Takashi; Yamamoto, Daisuke

    2011-06-01

    Complications derived from diabetes mellitus are caused by nonenzymatic protein glycation at the specific sites. LC/MS/MS was performed for the identification of the tryptic peptides of glycated hemoglobins using glyceraldehyde. After the identification of the glycation or non-glycation site, computer analysis of the structure surrounding the sites was carried out using PDB data (1BZ0). Five glycated lysine residues (Lys-16(α), -56(α), -8(β), -82(β), and -144(β)) and four non-glycated lysine residues (Lys-7(α), -40(α), -99(α), and -132(β)) were identified. The non-glycated lysine residues, Lys-7(α), -40(α), and -132(β), are most likely to form electrostatic interactions with the β carboxyl group of Asp-74(α), C-terminal His-146(β), and Glu-7(β) by virtue of their proximity, which is 2.67-2.91 Å (N-O). Additionally, there are histidine residues within 4.55-7.38 Å (N-N) around eight sites except for Lys-7(α). We conclude that the following factors seem to be necessary for glycation of lysine residues: (i) the apparent absence of aspartate or glutamate residues to inhibit the glycation reaction by forming an electrostatic interaction, (ii) the presence of histidine residues for acid-base catalysis of the Amadori rearrangement, and (iii) the presence of an amino acid residue capable of stabilizing a phosphate during proton transfer.

  5. Dilemmas surrounding passive euthanasia--a Malaysian perspective.

    Science.gov (United States)

    Talib, Norchaya

    2005-09-01

    In western societies where the principle of autonomy is jealously guarded, perhaps active euthanasia is more often the focus of public concern and debates rather than any other forms of euthanasia. However due to the advance in technology and its corresponding ability in prolonging life, in Malaysia passive euthanasia presents more of a dilemma. For those concerned and involved with end of life decision-making, it is generally agreed that this is an area fraught with not only medical but legal and ethical issues. In Malaysia where the society is not homogenous but is multi-cultural and multi-religious, in addition to medical, legal and ethical issues, religious principles and cultural norms further impact and play significant roles in end of life decision-making. This paper seeks to identify the issues surrounding the practice of passive euthanasia in Malaysia. It will be shown that despite applicable legal provisions, current practice of the medical profession combined with religious and cultural values together affect decision-making which involves the withholding and/or withdrawing of life-saving treatment.

  6. Mercury's interior, surface, and surrounding environment latest discoveries

    CERN Document Server

    Clark, Pamela Elizabeth

    2015-01-01

    This SpringerBrief details the MESSENGER Mission, the findings of which present challenges to widely held conventional views and remaining mysteries surrounding the planet. The work answers the question of why Mercury is so dense, and the implications from geochemical data on its planetary formation. It summarizes imaging and compositional data from the terrestrial planet surface processes and explains the geologic history of Mercury.  It also discusses the lack of southern hemisphere coverage. Our understanding of the planet Mercury has been in a transitional phase over the decades since Mariner 10. The influx of new data from the NASA MESSENGER Mission since it was inserted into the orbit of Mercury in March of 2011 has greatly accelerated that shift. The combined compositional data of relatively high volatiles (S, K), relatively low refractories (Al, Ca), and low crustal iron, combined with an active, partially molten iron rich core, has major implications for Mercury and Solar System formation. From a s...

  7. Zonal disintegration phenomenon in rock mass surrounding deep tunnels

    Institute of Scientific and Technical Information of China (English)

    WU Hao; FANG Qin; GUO Zhi-kun

    2008-01-01

    Zonal disintegration is a typical static phenomenon of deep rock masses. It has been defined as alternating regions of fractured and relatively intact rock mass that appear around or in front of the working stope during excavation of a deep tunnel. Zonal disintegration phenomenon was successfully demonstrated in the laboratory with 3D tests on analogous gypsum models, two circular cracked zones were observed in the test. The linear Mohr-Coulomb yield criterion was used with a constitutive model that showed linear softening and ideal residual plastic to analyze the elasto-plastic field of the enclosing rock mass around a deep tunnel. The results show that tunneling causes a maximum stress zone to appear between an elastic and plastic zone in the surrounding rock. The zonal disintegration phenomenon is analyzed by considering the stress-strain state of the rock mass in the vicinity of the maximum stress zone. Creep instability failure of the rock due to the development of the plastic zone, and transfer of the maximum stress zone into the rock mass, are the cause of zonal disintegration. An analytical criterion for the critical depth at which zonal disintegration can occur is derived. This depth depends mainly on the character and stress concentration coefficient of the rock mass.

  8. Beliefs and practices surrounding postpartum period among Myanmar women.

    Science.gov (United States)

    Sein, Kyi Kyi

    2013-11-01

    to examine the postpartum beliefs and practices among young women (15-24 years) both quantitative and qualitative approaches were used: a cross-sectional comparative study using a semi-structured questionnaire and focus group discussions (FGDs). Kyimyindaing Township in the western district of Yangon, Myanmar. young women (15-24 years) who had experience of at least one live birth were included. A total of 196 women for a quantitative survey and 31 women for FGDs were recruited. postpartum beliefs and practices at the last childbirth were explored by a pretested semi-structured questionnaire and four FGDs (two in urban and two in rural areas). The survey questionnaire covered socio-demographic data, food and behavioural restrictions and observances during the last postpartum period and underlying reasons for those practices. Majority of participants followed the traditional postpartum practices regardless of the area of residence and education level. Notion of 'dirty lochia' was identified. traditional beliefs and practices surrounding post partum were highly prevalent among young women. Variation in degree and duration of adherence to postpartum taboos was noted. These beliefs and practices were imparted and perpetuated by women's close social network. the findings point out the importance of awareness of postpartum beliefs and practices among health staff for providing culturally sensitive health care and gaining better co-operation and mutual understanding in giving health care. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Unilateral lung agenesis--detrimental roles of surrounding vessels.

    Science.gov (United States)

    Chou, An-Kou; Huang, Shu-Chien; Chen, Shyh-Jye; Huang, Pei-Ming; Wang, Jou-Kou; Wu, Mei-Hwan; Chen, Yih-Sharng; Chang, Chung-I; Chiu, Ing-Sh; Wu, En-Ting

    2007-03-01

    Unilateral lung agenesis is a rare congenital defect and could be associated with multiple abnormalities. The patients usually have poor long-term outcomes especially in those with right lung agenesis. We reviewed the 10-year experience in our hospital to describe special clinical features and try to delineate the causes of poor outcomes. From 1995 to 2005, 14 patients less than 18 years of age with unilateral lung agenesis (4 with left agenesis, 10 with right agenesis) were enrolled. Medical records reviewed included diagnosis, presentation, chromosome anomalies, cardiovascular anomalies and interventions, outcomes. We found that the mechanisms of severe airway disease in right lung agenesis included (1) trachea compression by the aortic arch, (2) the presence of "pseudo-ring-sling complex," (3) distended pulmonary artery due to left to right shunt which impinged the only bronchus, and finally (4) the persistent LSVC that restricts the growth of trachea. The etiologies of airway complication in left lung agenesis included anomalous aortic arch compression on trachea and the coexisting heart disease with significant left to right shunt, which impinged on the bronchus. In conclusion, unilateral lung agenesis has frequently associated airway problems due to its surrounding vessels. Satisfactory airway intervention remains challenging. This disease still requires great effort to improve patient outcomes.

  10. The interstellar cloud surrounding the Sun -- a new perspective

    CERN Document Server

    Gry, Cecile

    2014-01-01

    Aims: We offer a new, simpler picture of the local interstellar medium around the Sun (LISM) made of a single continuous cloud enveloping the Sun. This new outlook enables the description of a diffuse cloud from within and brings to light some unexpected properties. Methods: We re-examine the kinematics and abundances of the local interstellar medium, as revealed by the published results for the ultraviolet absorption lines of MgII, FeII and HI. Results: In contrast to previous representations, our new picture of the LISM consists of a single, monolithic cloud that surrounds the Sun in all directions and accounts for most of the matter present in the first 50 parsecs around the Sun. The cloud fills the space around us out to about 9 pc in most directions, although its boundary is very irregular with possibly a few extensions up to 20 pc. The cloud does not behave like a rigid body: gas within the cloud is being differentially decelerated in the direction of motion, and the cloud is expanding in directions per...

  11. Dense Ionized and Neutral Gas Surrounding Sgr A*

    CERN Document Server

    Shukla, Hemant; Scoville, N Z

    2004-01-01

    We present high resolution H41a hydrogen recombination line observations of the 1.2' (3 pc) region surrounding Sgr A* at 92 GHz using the OVRO Millimeter Array with an angular resolution of 7" x 3" and velocity resolution of 13 km/s. New observations of H31a, H35a, H41a, and H44a lines were obtained using the NRAO 12-m telescope, and their relative line strengths are interpreted in terms of various emission mechanisms. These are the most extensive and most sensitive observations of recombination line to date. Observations of HCO+ (1 - 0) transition at 89 GHz are also obtained simultaneously with a 40% improved angular resolution and 4-15 times improved sensitivity over previous observations, and the distribution and kinematics of the dense molecular gas in the circumnuclear disk (CND) are mapped and compared with those of the ionized gas. The line brightness ratios of the hydrogen recombination lines are consistent with purely spontaneous emission from 7000 K gas with n_e = 20,000 cm$^{-3}$ near LTE condition...

  12. Instability of Magnetized Ionization Fronts Surrounding H II Regions

    CERN Document Server

    Kim, Jeong-Gyu

    2014-01-01

    An ionization front (IF) surrounding an H II region is a sharp interface where a cold neutral gas makes transition to a warm ionized phase by absorbing UV photons from central stars. We investigate the instability of a plane-parallel D-type IF threaded by parallel magnetic fields, by neglecting the effects of recombination within the ionized gas. We find that weak D-type IFs always have the post-IF magnetosonic Mach number $\\mathcal{M}_{\\rm M2} \\leq 1$. For such fronts, magnetic fields increase the maximum propagation speed of the IFs, while reducing the expansion factor $\\alpha$ by a factor of $1+1/(2\\beta_1)$ compared to the unmagnetized case, with $\\beta_1$ denoting the plasma beta in the pre-IF region. IFs become unstable to distortional perturbations due to gas expansion across the fronts, exactly analogous to the Darrieus-Landau instability of ablation fronts in terrestrial flames. The growth rate of the IF instability is proportional linearly to the perturbation wavenumber as well as the upstream flow ...

  13. An insight in the surroundings of HR4796

    CERN Document Server

    Lagrange, A -M; Boccaletti, A; Lacour, S; Thebault, P; Chauvin, G; Mouillet, D; Augereau, J C; Bonnefoy, M; Ehrenreich, D; Kral, Q

    2012-01-01

    HR4796 is a young, early A-type star harbouring a well structured debris disk, shaped as a ring with sharp inner edges. It forms with the M-type star HR4796B a binary system, with a proj. sep. ~560 AU. Our aim is to explore the surroundings of HR4796A and B, both in terms of extended or point-like structures. Adaptive optics images at L'-band were obtained with NaCo in Angular Differential Mode and with Sparse Aperture Masking (SAM). We analyse the data as well as the artefacts that can be produced by ADI reduction on an extended structure with a shape similar to that of HR4796A dust ring. We determine constraints on the presence of companions using SAM and ADI on HR4796A, and ADI on HR4796B. We also performed dynamical simulations of a disk of planetesimals and dust produced by collisions, perturbed by a planet located close to the disk outer edge. The disk ring around HR4796A is well resolved. We highlight the potential effects of ADI reduction of the observed disk shape and surface brightness distribution,...

  14. Dead discs, unstable discs and the stars they surround

    Directory of Open Access Journals (Sweden)

    D’Angelo Caroline

    2014-01-01

    Full Text Available Strong stellar magnetic fields significantly alter the behaviour of surrounding accretion discs. Recent work has demonstrated that at low accretion rates a large amount of mass can remain confined in the disc, contrary to the standard assumption that the magnetic field will expel the disc in an outflow (the “propeller regime”. These “dead discs” often become unstable, causing cycles of accretion onto the central star. Here I present the main predictions of this model, and argue that it provides a good explanation for the peculiar behaviour seen in several accreting sources with strong magnetic fields. I will focus in particular on three accreting millisecond X-ray pulsars: SAX J1808.4-3658, NGC 6440 X-2 and IGR J00291+5934. These sources all show low-frequency quasi-periodic oscillations consistent with a variable accretion rate, as well as unusual outburst patterns that suggest gas is confined in the inner disc regions during quiescence.

  15. Preliminary Analysis of Slope Stability in Kuok and Surrounding Areas

    Directory of Open Access Journals (Sweden)

    Dewandra Bagus Eka Putra

    2016-12-01

    Full Text Available The level of slope influenced by the condition of the rocks beneath the surface. On high level of slopes, amount of surface runoff and water transport energy is also enlarged. This caused by greater gravity, in line with the surface tilt from the horizontal plane. In other words, topsoil eroded more and more. When the slope becomes twice as steep, then the amount of erosion per unit area be 2.0 - 2.5 times more. Kuok and surrounding area is the road access between the West Sumatra and Riau which plays an important role economies of both provinces. The purpose of this study is to map the locations that have fairly steep slopes and potential mode of landslides. Based on SRTM data obtained,  the roads in Kuok area has a minimum elevation of + 33 m and a maximum  + 217.329 m. Rugged road conditions with slope ranging from 24.08 ° to 44.68 ° causing this area having frequent landslides. The result of slope stability analysis in a slope near the Water Power Plant Koto Panjang, indicated that mode of active failure is toppling failure or rock fall and the potential zone of failure is in the center part of the slope.

  16. Expression of zebrafish nos2b surrounds oral cavity.

    Science.gov (United States)

    Poon, Kar-Lai; Richardson, Michael; Korzh, Vladimir

    2008-06-01

    Inducible nitric oxide synthase (NOS2) catalyzes the production of nitric oxide (NO), and is one of the factors establishing innate immunity. In zebrafish, Nos2 is represented by nos2a and nos2b. Here, we report the cloning and expression pattern of the zebrafish nos2b gene, which does not seem to participate in induced immune response. nos2b was mapped to zebrafish linkage group 15. The spatial and temporal expression pattern of nos2b in embryonic zebrafish was analyzed by whole-mount in situ hybridization. nos2b is expressed constitutively in two primordia located along the ventral midline. The first group of cells contributes to the neurohypophysis. Initially at the level of the ventral hindbrain, the second group of cells migrates closely with the thyroid primordium to its final position at the basihyal by 3 dpf. Thus, the analysis of expression pattern of nos2b reveals complex morphogenetic movements resulting in its expression surrounding the oral cavity.

  17. Thermoelectric Performance Enhancement by Surrounding Crystalline Semiconductors with Metallic Nanoparticles

    Science.gov (United States)

    Kim, Hyun-Jung; King, Glen C.; Park, Yeonjoon; Lee, Kunik; Choi, Sang H.

    2011-01-01

    Direct conversion of thermal energy to electricity by thermoelectric (TE) devices may play a key role in future energy production and utilization. However, relatively poor performance of current TE materials has slowed development of new energy conversion applications. Recent reports have shown that the dimensionless Figure of Merit, ZT, for TE devices can be increased beyond the state-of-the-art level by nanoscale structuring of materials to reduce their thermal conductivity. New morphologically designed TE materials have been fabricated at the NASA Langley Research Center, and their characterization is underway. These newly designed materials are based on semiconductor crystal grains whose surfaces are surrounded by metallic nanoparticles. The nanoscale particles are used to tailor the thermal and electrical conduction properties for TE applications by altering the phonon and electron transport pathways. A sample of bismuth telluride decorated with metallic nanoparticles showed less thermal conductivity and twice the electrical conductivity at room temperature as compared to pure Bi2Te3. Apparently, electrons cross easily between semiconductor crystal grains via the intervening metallic nanoparticle bridges, but phonons are scattered at the interfacing gaps. Hence, if the interfacing gap is larger than the mean free path of the phonon, thermal energy transmission from one grain to others is reduced. Here we describe the design and analysis of these new materials that offer substantial improvements in thermoelectric performance.

  18. Democratizing rendering for multiple viewers in surround VR systems

    KAUST Repository

    Schulze, Jürgen P.

    2012-03-01

    We present a new approach for how multiple users\\' views can be rendered in a surround virtual environment without using special multi-view hardware. It is based on the idea that different parts of the screen are often viewed by different users, so that they can be rendered from their own view point, or at least from a point closer to their view point than traditionally expected. The vast majority of 3D virtual reality systems are designed for one head-tracked user, and a number of passive viewers. Only the head tracked user gets to see the correct view of the scene, everybody else sees a distorted image. We reduce this problem by algorithmically democratizing the rendering view point among all tracked users. Researchers have proposed solutions for multiple tracked users, but most of them require major changes to the display hardware of the VR system, such as additional projectors or custom VR glasses. Our approach does not require additional hardware, except the ability to track each participating user. We propose three versions of our multi-viewer algorithm. Each of them balances image distortion and frame rate in different ways, making them more or less suitable for certain application scenarios. Our most sophisticated algorithm renders each pixel from its own, optimized camera perspective, which depends on all tracked users\\' head positions and orientations. © 2012 IEEE.

  19. Representing the egocentric auditory space: relationships of surrounding region concepts.

    Science.gov (United States)

    Campos, Marcella C; Hermann, Thomas; Schack, Thomas; Bläsing, Bettina

    2013-03-01

    We investigated the representation of azimuthal directions of sound sources under two different conditions. In the first experiment, we examined the participants' mental representation of sound source directions via similarity judgments. Auditory stimuli originating from sixteen loudspeakers positioned equidistantly around the participant were presented in pairs, with the first stimulus serving as the anchor, and thereby providing the context for the second stimulus. For each pair of stimuli, participants had to rate the sound source directions as either similar or dissimilar. In the second experiment, the same participants categorized single sound source directions using verbal direction labels (front, back, left, right, and combinations of any two of these). In both experiments, the directions within the front and back regions were more distinctively categorized than those on the sides, and the sides' categories included more directions than those of the front or back. Furthermore, we found evidence that the left-right decision comprises the basic differentiation of the surrounding regions. These findings illustrate what seem to be central features of the representation of directions in auditory space.

  20. Critical asymmetry in renormalization group theory for fluids.

    Science.gov (United States)

    Zhao, Wei; Wu, Liang; Wang, Long; Li, Liyan; Cai, Jun

    2013-06-21

    The renormalization-group (RG) approaches for fluids are employed to investigate critical asymmetry of vapour-liquid equilibrium (VLE) of fluids. Three different approaches based on RG theory for fluids are reviewed and compared. RG approaches are applied to various fluid systems: hard-core square-well fluids of variable ranges, hard-core Yukawa fluids, and square-well dimer fluids and modelling VLE of n-alkane molecules. Phase diagrams of simple model fluids and alkanes described by RG approaches are analyzed to assess the capability of describing the VLE critical asymmetry which is suggested in complete scaling theory. Results of thermodynamic properties obtained by RG theory for fluids agree with the simulation and experimental data. Coexistence diameters, which are smaller than the critical densities, are found in the RG descriptions of critical asymmetries of several fluids. Our calculation and analysis show that the approach coupling local free energy with White's RG iteration which aims to incorporate density fluctuations into free energy is not adequate for VLE critical asymmetry due to the inadequate order parameter and the local free energy functional used in the partition function.

  1. Lanthanide single molecule magnets

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Jinkui; Zhang, Peng [Chinese Academy of Sciences, Changchun (China). Changchun Inst. of Applied Chemistry

    2015-10-01

    This book begins by providing basic information on single-molecule magnets (SMMs), covering the magnetism of lanthanide, the characterization and relaxation dynamics of SMMs and advanced means of studying lanthanide SMMs. It then systematically introduces lanthanide SMMs ranging from mononuclear and dinuclear to polynuclear complexes, classifying them and highlighting those SMMs with high barrier and blocking temperatures - an approach that provides some very valuable indicators for the structural features needed to optimize the contribution of an Ising type spin to a molecular magnet. The final chapter presents some of the newest developments in the lanthanide SMM field, such as the design of multifunctional and stimuli-responsive magnetic materials as well as the anchoring and organization of the SMMs on surfaces. In addition, the crystal structure and magnetic data are clearly presented with a wealth of illustrations in each chapter, helping newcomers and experts alike to better grasp ongoing trends and explore new directions.

  2. Astrochemistry and Interstellar Molecules

    Science.gov (United States)

    Minh, Y. C.

    2010-03-01

    Astrochemistry provides powerful tools to understand various cosmic phenomena, including those in our solar system to the large-scale structure of the universe. In addition, the chemical property of an astronomical body is a crucial factor which governs the evolution of the system. Recent progress in astrophysical theories, computational modelings, and observational techniques requires a detailed understanding of the interactions between the constituents of an astronomical system, which are atoms and molecules within the system. Especially the far-infrared/sub-millimeter wave range, which is called as the last frontier in astronomical observations, contains numerous molecular lines, which may provide a huge amount of new information. However, we need an astrochemical understanding to use this information fully. Although this review is very limited, I would like to stress the importance of astrochemical approach in this overview for the field, which is getting much more attention than ever before.

  3. Lanthanide single molecule magnets

    CERN Document Server

    Tang, Jinkui

    2015-01-01

    This book begins by providing basic information on single-molecule magnets (SMMs), covering the magnetism of lanthanide, the characterization and relaxation dynamics of SMMs, and advanced means of studying lanthanide SMMs. It then systematically introduces lanthanide SMMs ranging from mononuclear and dinuclear to polynuclear complexes, classifying them and highlighting those SMMs with high barrier and blocking temperatures – an approach that provides some very valuable indicators for the structural features needed to optimize the contribution of an Ising type spin to a molecular magnet. The final chapter presents some of the newest developments in the lanthanide SMM field, such as the design of multifunctional and stimuli-responsive magnetic materials as well as the anchoring and organization of the SMMs on surfaces. In addition, the crystal structure and magnetic data are clearly presented with a wealth of illustrations in each chapter, helping newcomers and experts alike to better grasp ongoing trends and...

  4. Forces in molecules.

    Science.gov (United States)

    Hernández-Trujillo, Jesús; Cortés-Guzmán, Fernando; Fang, De-Chai; Bader, Richard F W

    2007-01-01

    Chemistry is determined by the electrostatic forces acting within a collection of nuclei and electrons. The attraction of the nuclei for the electrons is the only attractive force in a molecule and is the force responsible for the bonding between atoms. This is the attractive force acting on the electrons in the Ehrenfest force and on the nuclei in the Feynman force, one that is countered by the repulsion between the electrons in the former and by the repulsion between the nuclei in the latter. The virial theorem relates these forces to the energy changes resulting from interactions between atoms. All bonding, as signified by the presence of a bond path, has a common origin in terms of the mechanics determined by the Ehrenfest, Feynman and virial theorems. This paper is concerned in particular with the mechanics of interaction encountered in what are classically described as 'nonbonded interactions'--are atoms that 'touch' bonded or repelling one another?

  5. Is the protein surrounding the active site critical for hydrogen peroxide reduction by selenoprotein glutathione peroxidase? An ONIOM study.

    Science.gov (United States)

    Prabhakar, Rajeev; Vreven, Thom; Frisch, Michael J; Morokuma, Keiji; Musaev, Djamaladdin G

    2006-07-13

    In this ONIOM(QM:MM) study, we evaluate the role of the protein surroundings in the mechanism of H2O2 reduction catalyzed by the glutathione peroxidase enzyme, using the whole monomer (3113 atoms in 196 amino acid residues) as a model. A new optimization scheme that allows the full optimization of transition states for large systems has been utilized. It was found that in the presence of the surrounding protein the optimized active site structure bears a closer resemblance to the one in the X-ray structure than that without the surrounding protein. H2O2 reduction occurs through a two-step mechanism. In the first step, the selenolate anion (E-Se(-)) formation occurs with a barrier of 16.4 kcal/mol and is endothermic by 12.0 kcal/mol. The Gln83 residue plays the key role of the proton abstractor, which is in line with the experimental suggestion. In the second step, the O-O bond is cleaved, and selenenic acid (R-Se-OH) and a water molecule are formed. The calculated barrier for this process is 6.0 kcal/mol, and it is exothermic by 80.9 kcal/mol. The overall barrier of 18.0 kcal/mol for H2O2 reduction is in reasonable agreement with the experimentally measured barrier of 14.9 kcal/mol. The protein surroundings has been calculated to exert a net effect of only 0.70 kcal/mol (in comparison to the "active site only" model including solvent effects) on the overall barrier, which is most likely due to the active site being located at the enzyme surface.

  6. Lipids and glycosphingolipids in caveolae and surrounding plasma membrane of primary rat adipocytes.

    Science.gov (United States)

    Ortegren, Unn; Karlsson, Margareta; Blazic, Natascha; Blomqvist, Maria; Nystrom, Fredrik H; Gustavsson, Johanna; Fredman, Pam; Strålfors, Peter

    2004-05-01

    We have made a comprehensive and quantitative analysis of the lipid composition of caveolae from primary rat fat cells and compared the composition of plasma membrane inside and outside caveolae. We isolated caveolae from purified plasma membranes using ultrasonication in carbonate buffer to disrupt the membrane, or extraction with nonionic detergent, followed by density gradient ultracentrifugation. The carbonate-isolated caveolae fraction was further immunopurified using caveolin antibodies. Carbonate-isolated caveolae were enriched in cholesterol and sphingomyelin, and the concentration was three- and twofold higher, respectively, in caveolae compared to the surrounding plasma membrane. The concentration of glycerophospholipids was similar suggesting that glycerophospholipids constitute a constant core throughout the plasma membrane. The composition of detergent-insoluble fractions of the plasma membrane was very variable between preparations, but strongly enriched in sphingomyelin and depleted of glycerophospholipids compared to carbonate-isolated caveolae; indicating that detergent extraction is not a suitable technique for caveolae preparation. An average adipocyte caveola contained about 22 x 10(3) molecules of cholesterol, 7.5 x 10(3) of sphingomyelin and 23 x 10(3) of glycerophospholipid. The glycosphingolipid GD3 was highly enriched in caveolae, whereas GM3, GM1 and GD1a were present inside as well as outside the caveolae membrane. GD1b, GT1b, GM2, GQ1b, sulfatide and lactosylceramide sulfate were not detected in caveolae.

  7. ADSORPTION OF ASSOCIATING FLUIDS AT ACTIVE SURFACES: A DENSITY FUNCTIONAL THEORY

    Directory of Open Access Journals (Sweden)

    S.Tripathi

    2003-01-01

    Full Text Available We present a density functional theory (DFT to describe adsorption in systems where molecules of associating fluids can bond (or associate with discrete, localized functional groups attached to the surfaces, in addition to other fluid molecules. For such systems as water adsorbing on activated carbon, silica, clay minerals etc. this is a realistic model to account for surface heterogeneity rather than using a continuous smeared surface-fluid potential employed in most of the theoretical works on adsorption on heterogeneous surfaces. Association is modelled within the framework of first order thermodynamic perturbation theory (TPT1. The new theory accurately predicts the distribution of bonded and non-bonded species and adsorption behavior under various conditions of bulk pressure, surface-fluid and fluid-fluid association strengths. Competition between the surface-fluid and fluid-fluid association is analyzed for fluids with multiple association sites and its impact on adsorption is discussed. The theory, supported by simulations demonstrates that the extent and the nature of adsorption (e.g. monolayer vary with the number of association sites on the fluid molecules.

  8. Space Station fluid management logistics

    Science.gov (United States)

    Dominick, Sam M.

    1990-01-01

    Viewgraphs and discussion on space station fluid management logistics are presented. Topics covered include: fluid management logistics - issues for Space Station Freedom evolution; current fluid logistics approach; evolution of Space Station Freedom fluid resupply; launch vehicle evolution; ELV logistics system approach; logistics carrier configuration; expendable fluid/propellant carrier description; fluid carrier design concept; logistics carrier orbital operations; carrier operations at space station; summary/status of orbital fluid transfer techniques; Soviet progress tanker system; and Soviet propellant resupply system observations.

  9. Arrays of Individual DNA Molecules on Nanopatterned Substrates

    Science.gov (United States)

    Hager, Roland; Halilovic, Alma; Burns, Jonathan R.; Schäffler, Friedrich; Howorka, Stefan

    2017-02-01

    Arrays of individual molecules can combine the advantages of microarrays and single-molecule studies. They miniaturize assays to reduce sample and reagent consumption and increase throughput, and additionally uncover static and dynamic heterogeneity usually masked in molecular ensembles. However, realizing single-DNA arrays must tackle the challenge of capturing structurally highly dynamic strands onto defined substrate positions. Here, we create single-molecule arrays by electrostatically adhering single-stranded DNA of gene-like length onto positively charged carbon nanoislands. The nanosites are so small that only one molecule can bind per island. Undesired adsorption of DNA to the surrounding non-target areas is prevented via a surface-passivating film. Of further relevance, the DNA arrays are of tunable dimensions, and fabricated on optically transparent substrates that enable singe-molecule detection with fluorescence microscopy. The arrays are hence compatible with a wide range of bioanalytical, biophysical, and cell biological studies where individual DNA strands are either examined in isolation, or interact with other molecules or cells.

  10. GIANT Hα NEBULA SURROUNDING THE STARBURST MERGER NGC 6240

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Michitoshi [Hiroshima Astrophysical Science Center, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Yagi, Masafumi; Komiyama, Yutaka; Kashikawa, Nobunari [Optical and Infrared Astronomy Division, National Astronomical Observatory, Mitaka, Tokyo 181-8588 (Japan); Ohyama, Youichi [Institute of Astronomy and Astrophysics, Academia Sinica, 11F of Astronomy-Mathematics Building, AS/NTU No.1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan, R.O.C. (China); Tanaka, Hisashi [Department of Physical Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Okamura, Sadanori, E-mail: yoshidam@hiroshima-u.ac.jp [Department of Advanced Sciences, Faculty of Science and Engineering, Hosei University, Koganei, Tokyo 184-8584 (Japan)

    2016-03-20

    We revealed the detailed structure of a vastly extended Hα-emitting nebula (“Hα nebula”) surrounding the starburst/merging galaxy NGC 6240 by deep narrow-band imaging observations with the Subaru Suprime-Cam. The extent of the nebula is ∼90 kpc in diameter and the total Hα luminosity amounts to L{sub Hα} ≈ 1.6 × 10{sup 42} erg s{sup −1}. The volume filling factor and the mass of the warm ionized gas are ∼10{sup −4}–10{sup −5} and ∼5 × 10{sup 8} M{sub ⊙}, respectively. The nebula has a complicated structure, which includes numerous filaments, loops, bubbles, and knots. We found that there is a tight spatial correlation between the Hα nebula and the extended soft-X-ray-emitting gas, both in large and small scales. The overall morphology of the nebula is dominated by filamentary structures radially extending from the center of the galaxy. A large-scale bipolar bubble extends along the minor axis of the main stellar disk. The morphology strongly suggests that the nebula was formed by intense outflows—superwinds—driven by starbursts. We also found three bright knots embedded in a looped filament of ionized gas that show head-tail morphologies in both emission-line and continuum, suggesting close interactions between the outflows and star-forming regions. Based on the morphology and surface brightness distribution of the Hα nebula, we propose the scenario that three major episodes of starburst/superwind activities, which were initiated ∼10{sup 2} Myr ago, formed the extended ionized gas nebula of NGC 6240.

  11. IRIS Observation of a Sunspot and the Surrounding Plage Region

    Science.gov (United States)

    TIAN, H.; DeLuca, E. E.; Mcintosh, S. W.; Reeves, K. K.; McKillop, S.; Weber, M.; Saar, S.; Golub, L.; Testa, P.

    2013-12-01

    NASA's IRIS mission is providing high-cadence and high-resolution observations of the solar transition region and chromosphere. We present preliminary results from IRIS observation of a sunspot and the surrounding plage region. The major findings in this observation can be summarized as following: (1) The slit jaw images in the filters of 1400Å and 1330Å reveal the presence of many rapidly evolving fibril-like structures in the transition region for the first time. These thin and long structures mainly reside in the plage region. They could be strands of low-lying cool transition region loops or the transition region counterpart of chromospheric spicules. (2) The C II and Mg II line profiles are almost Gaussian in the sunspot umbra and clearly exhibit a deep reversal at the line center in the plage region, suggesting a greatly reduced opacity in the sunspot atmosphere. (3) Bidirectional jets are frequently occurring mainly in the plage region immediately outside the sunspot throughout the observation. Triple or double Gaussian fit to the line profiles of Si IV suggests a velocity as high as 100 km/s. These velocity values are of the same order of the Alfven speed in the transition region. (4)Three-minute oscillation is clearly present in the sunspot umbra. The oscillation is identified in not only the slit jaw images of 2796Å, 1400Å and 1330Å, but also in spectra of the bright Mg II, C II and Si IV lines. Strong non-linearity is clearly seen in the intensity and Doppler shift oscillations. Interestingly, the obvious increase of the line width only occurs at the times of largest blue shift. The correlated change of the intensity and Doppler shift suggests an upward propagating magneto-acoustic shock wave.

  12. Isoperimetric inequalities in surround system and space science

    Directory of Open Access Journals (Sweden)

    JiaJin Wen

    2016-02-01

    Full Text Available Abstract By means of the algebraic, analysis, convex geometry, computer, and inequality theories we establish the following isoperimetric inequality in the centered 2-surround system S ( 2 { P , Γ , l } $S^{(2} \\{P,\\varGamma ,l \\}$ : ( 1 | Γ | ∮ Γ r ¯ P p 1 / p ⩽ | Γ | 4 π sin l π | Γ | [ csc l π | Γ | + cot 2 l π | Γ | ln ( tan l π | Γ | + sec l π | Γ | ] , ∀ p ⩽ − 2 . $$\\begin{aligned}& \\biggl(\\frac{1}{|\\varGamma |} \\oint_{\\varGamma }\\bar{r}_{P}^{p} \\biggr^{1/p}\\leqslant\\frac{|\\varGamma |}{4\\pi}\\sin\\frac{l\\pi}{|\\varGamma |} \\biggl[ \\csc \\frac{l\\pi}{|\\varGamma |}+\\cot^{2} \\frac{l\\pi}{|\\varGamma |} \\ln \\biggl(\\tan \\frac{l\\pi}{|\\varGamma |}+\\sec\\frac{l\\pi}{|\\varGamma |} \\biggr \\biggr], \\\\& \\quad \\forall p\\leqslant -2. \\end{aligned}$$ As an application of the inequality in space science, we obtain the best lower bounds of the mean λ-gravity norm ∥ F λ ( Γ , P ∥ ‾ $\\overline{\\Vert {\\mathbf{F}}_{\\lambda} ( \\varGamma ,P \\Vert }$ as follows: ∥ F λ ( Γ , P ∥ ‾ ≜ 1 | Γ | ∮ Γ 1 ∥ A − P ∥ λ ⩾ ( 2 π | Γ | λ , ∀ λ ⩾ 2 . $$\\overline{\\bigl\\Vert {\\mathbf{F}}_{\\lambda} ( \\varGamma ,P \\bigr\\Vert } \\triangleq\\frac{1}{|\\varGamma |} \\oint_{\\varGamma }\\frac{1}{\\|A-P\\|^{\\lambda }}\\geqslant \\biggl(\\frac{2\\pi}{|\\varGamma |} \\biggr^{\\lambda},\\quad \\forall \\lambda\\geqslant2. $$

  13. The interstellar cloud surrounding the Sun: a new perspective

    Science.gov (United States)

    Gry, Cécile; Jenkins, Edward B.

    2014-07-01

    Aims: We offer a new, simpler picture of the local interstellar medium, made of a single continuous cloud enveloping the Sun. This new outlook enables the description of a diffuse cloud from within and brings to light some unexpected properties. Methods: We re-examine the kinematics and abundances of the local interstellar gas, as revealed by the published results for the ultraviolet absorption lines of Mg II, Fe II, and H I. Results: In contrast to previous representations, our new picture of the local interstellar medium consists of a single, monolithic cloud that surrounds the Sun in all directions and accounts for most of the matter present in the first 50 parsecs around the Sun. The cloud fills the space around us out to about 9 pc in most directions, although its boundary is very irregular with possibly a few extensions up to 20 pc. The cloud does not behave like a rigid body: gas within the cloud is being differentially decelerated in the direction of motion, and the cloud is expanding in directions perpendicular to this flow, much like a squashed balloon. Average H I volume densities inside the cloud vary between 0.03 and 0.1 cm-3 over different directions. Metals appear to be significantly depleted onto grains, and there is a steady increase in depletion from the rear of the cloud to the apex of motion. There is no evidence that changes in the ionizing radiation influence the apparent abundances. Secondary absorption components are detected in 60% of the sight lines. Almost all of them appear to be interior to the volume occupied by the main cloud. Half of the sight lines exhibit a secondary component moving at about -7.2 km s-1 with respect to the main component, which may be the signature of a shock propagating toward the cloud's interior.

  14. DEFORMATION OF MOISTURE FLUX CIRCULATION SURROUNDING THE LANDFALL TYPHOON "BILIS"

    Institute of Scientific and Technical Information of China (English)

    RAN Ling-kun; YANG Wen-xia; HONG Yan-chao

    2009-01-01

    The deformation parameter (DP), which is defined as the product of shear deformation and stretching deformation of moisture flux circulation, is introduced. The tendency equation of DP is derived in pressure coordinates. Furthermore, DP is used to diagnose the deformation character of moisture flux circulation in the periphery of Bilis. The analysis showed that before Bilis landed, DP presented eight abnormal areas, which distributed alternately and closely encircled the low-pressure center. This indicated that the moisture flux circulation in the periphery of Bilis rotated counterclockwise and stretched longitudinally and latitudinally to deform. After Bilis landed, DP weakened gradually and its regular pattern of horizontal distribution loosened. The shear and stretching deformations of moisture flux circulation surrounding Bilis weakened after the typhoon landed. The deformation of moisture flux circulation in the periphery of Bilis mainly appeared in the middle-lower troposphere. There existed 1/2 phase difference between the shear and stretching deformations in the vertical-latitudinal cross section and a π/4 phase difference between them on the horizontal plane. As Bilis landed and further moved inland of China, the intensities of DP, shear and stretching deformations decreased, meanwhile their vertical and horizontal structures became irregular. The chief dynamic factors responsible for the deformation of moisture flux circulation in the periphery of Bilis were the three terms associated with the three-dimensional advection transportation of DP, square difference between shear and stretching deformations coupling with Coriolis parameter, and horizontal gradient of geopotential height before Bilis landed. The last two dynamic factors impacted jointly on the deformation of moisture flux circulation after Bilis landed.

  15. Rain Simulation for the Test of Automotive Surround Sensors

    Science.gov (United States)

    Hasirlioglu, Sinan; Riener, Andreas; Doric, Igor

    2017-04-01

    The WHO Global Health Observatory data indicates that over 1.25 million people die in traffic accidents annually. To save lives, car manufacturers spend lot of efforts on the development of novel safety systems aiming to avoid or mitigate accidents and provide maximum protection for vehicle occupants as well as vulnerable road users. All the safety features mainly rely on data from surround sensors such as radar, lidar and camera and intelligent vehicles today use these environmental data for instant decision making and vehicle control. As already small errors in sensor data measurements could lead to catastrophes like major injuries or road traffic fatalities, it is of utmost importance to ensure high reliability and accuracy of sensors and safety systems. This work focuses on the influence of environmental factors such as rain conditions, as it is known that rain drops scatter the electromagnetic waves. The result is incorrect measurements with a direct negative impact on environment detection. To identify potential problems of sensors under varying environmental conditions, systems are today tested in real-world settings with two main problems: First, tests are time-consuming and second, environmental conditions are not reproducible. Our approach to test the influence of weather on automotive sensors is to use an indoor rain simulator. Our artificial rain maker, installed at CARISSMA (Center of Automotive Research on Integrated Safety Systems and Measurement Area), is parametrized with rain characteristics measured in the field using a standard disdrometer. System behavior on artificial rain is compared and validated with natural rainfall. With this simulator it is finally possible to test environmental influence at various levels and under reproducible conditions. This saves lot of efforts required for the test process itself and furthermore has a positive impact on the reliability of sensor systems due to the fact that test driven development is enabled.

  16. Dynamics of Complex Fluid-Fluid Interfaces

    NARCIS (Netherlands)

    Sagis, L.M.C.

    2016-01-01

    This chapter presents an overview of recent progress in modelling the behaviour of complex fluid–fluid interfaces with non-equilibrium thermodynamics. We will limit ourselves to frameworks employing the Gibbs dividing surface model, and start with a general discussion of the surface excess variables

  17. Single-molecule studies of DNA by molecular combing

    Institute of Scientific and Technical Information of China (English)

    Liu Yuying; Wang Pengye; Dou Shuoxing

    2007-01-01

    Molecular combing is a powerful method for aligning a large array of DNA molecules onto a surface. It is a process whereby DNA molecules are stretched and aligned on a glass surface by the force via fluid flow. The ability to comb up to several hundred DNAs on a single cover slip allows for a statistically significant number of measurements to be made. These features make molecular combing an attractive tool for genomic studies, such as DNA replication, DNA transcription, DNA-protein interaction and so on. In this review article, we discuss the molecular combing principle, method and its applications.

  18. Fluid loading responsiveness

    NARCIS (Netherlands)

    Geerts, Bart

    2011-01-01

    Patients in the intensive care unit (ICU) and in the peri-operative phase are dependent on physicians and nurses for their fluid intake. Volume status optimization is required to maximize oxygen delivery to vital organs. Unnecessary fluid administration can, however, lead to general and pulmonary

  19. Fluid loading responsiveness

    NARCIS (Netherlands)

    Geerts, Bart

    2011-01-01

    Patients in the intensive care unit (ICU) and in the peri-operative phase are dependent on physicians and nurses for their fluid intake. Volume status optimization is required to maximize oxygen delivery to vital organs. Unnecessary fluid administration can, however, lead to general and pulmonary oe

  20. Peritoneal fluid culture

    Science.gov (United States)

    Culture - peritoneal fluid ... sent to the laboratory for Gram stain and culture. The sample is checked to see if bacteria ... The peritoneal fluid culture may be negative, even if you have ... diagnosis of peritonitis is based on other factors, in addition ...

  1. Applications of fluid dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Round, G.R.; Garg, V.K.

    1986-01-01

    This book describes flexible and practical approach to learning the basics of fluid dynamics. Each chapter is a self-contained work session and includes a fluid dynamics concept, an explanation of the principles involved, an illustration of their application and references on where more detailed discussions can be found.

  2. Fluid loading responsiveness

    NARCIS (Netherlands)

    Geerts, Bart

    2011-01-01

    Patients in the intensive care unit (ICU) and in the peri-operative phase are dependent on physicians and nurses for their fluid intake. Volume status optimization is required to maximize oxygen delivery to vital organs. Unnecessary fluid administration can, however, lead to general and pulmonary oe

  3. Complex fluids in biological systems experiment, theory, and computation

    CERN Document Server

    2015-01-01

    This book serves as an introduction to the continuum mechanics and mathematical modeling of complex fluids in living systems. The form and function of living systems are intimately tied to the nature of surrounding fluid environments, which commonly exhibit nonlinear and history dependent responses to forces and displacements. With ever-increasing capabilities in the visualization and manipulation of biological systems, research on the fundamental phenomena, models, measurements, and analysis of complex fluids has taken a number of exciting directions. In this book, many of the world’s foremost experts explore key topics such as: Macro- and micro-rheological techniques for measuring the material properties of complex biofluids and the subtleties of data interpretation Experimental observations and rheology of complex biological materials, including mucus, cell membranes, the cytoskeleton, and blood The motility of microorganisms in complex fluids and the dynamics of active suspensions Challenges and solut...

  4. Coalescence of bubbles and drops in an outer fluid

    CERN Document Server

    Paulsen, Joseph D; Kannan, Anerudh; Burton, Justin C; Nagel, Sidney R

    2014-01-01

    When two liquid drops touch, a microscopic connecting liquid bridge forms and rapidly grows as the two drops merge into one. Whereas coalescence has been thoroughly studied when drops coalesce in vacuum or air, many important situations involve coalescence in a dense surrounding fluid, such as oil coalescence in brine. Here we study the merging of gas bubbles and liquid drops in an external fluid. Our data indicate that the flows occur over much larger length scales in the outer fluid than inside the drops themselves. Thus we find that the asymptotic early regime is always dominated by the viscosity of the drops, independent of the external fluid. A phase diagram showing the crossovers into the different possible late-time dynamics identifies a dimensionless number that signifies when the external viscosity can be important.

  5. Fluid blade disablement tool

    Energy Technology Data Exchange (ETDEWEB)

    Jakaboski, Juan-Carlos [Albuquerque, NM; Hughs, Chance G [Albuquerque, NM; Todd, Steven N [Rio Rancho, NM

    2012-01-10

    A fluid blade disablement (FBD) tool that forms both a focused fluid projectile that resembles a blade, which can provide precision penetration of a barrier wall, and a broad fluid projectile that functions substantially like a hammer, which can produce general disruption of structures behind the barrier wall. Embodiments of the FBD tool comprise a container capable of holding fluid, an explosive assembly which is positioned within the container and which comprises an explosive holder and explosive, and a means for detonating. The container has a concavity on the side adjacent to the exposed surface of the explosive. The position of the concavity relative to the explosive and its construction of materials with thicknesses that facilitate inversion and/or rupture of the concavity wall enable the formation of a sharp and coherent blade of fluid advancing ahead of the detonation gases.

  6. Wave propagation in a chiral fluid an undergraduate study

    CERN Document Server

    Garel, T

    2003-01-01

    We study the propagation of electromagnetic waves in a chiral fluid, where the molecules are described by a simplified version of the Kuhn coupled oscillator model. The eigenmodes of Maxwell's equations are circularly polarized waves. The application of a static magnetic field further leads to a magnetochiral term in the index of refraction of the fluid, which is independent of the wave polarization. A similar result holds when absorption is taken into account. Interference experiments and photochemical reactions have recently demonstrated the existence of the magnetochiral term. The comparison with Faraday rotation in an achiral fluid emphasizes the different symmetry properties of the two effects.

  7. Amniotic fluid water dynamics.

    Science.gov (United States)

    Beall, M H; van den Wijngaard, J P H M; van Gemert, M J C; Ross, M G

    2007-01-01

    Water arrives in the mammalian gestation from the maternal circulation across the placenta. It then circulates between the fetal water compartments, including the fetal body compartments, the placenta and the amniotic fluid. Amniotic fluid is created by the flow of fluid from the fetal lung and bladder. A major pathway for amniotic fluid resorption is fetal swallowing; however in many cases the amounts of fluid produced and absorbed do not balance. A second resorption pathway, the intramembranous pathway (across the amnion to the fetal circulation), has been proposed to explain the maintenance of normal amniotic fluid volume. Amniotic fluid volume is thus a function both of the amount of water transferred to the gestation across the placental membrane, and the flux of water across the amnion. Membrane water flux is a function of the water permeability of the membrane; available data suggests that the amnion is the structure limiting intramembranous water flow. In the placenta, the syncytiotrophoblast is likely to be responsible for limiting water flow across the placenta. In human tissues, placental trophoblast membrane permeability increases with gestational age, suggesting a mechanism for the increased water flow necessary in late gestation. Membrane water flow can be driven by both hydrostatic and osmotic forces. Changes in both osmotic/oncotic and hydrostatic forces in the placenta my alter maternal-fetal water flow. A normal amniotic fluid volume is critical for normal fetal growth and development. The study of amniotic fluid volume regulation may yield important insights into the mechanisms used by the fetus to maintain water homeostasis. Knowledge of these mechanisms may allow novel treatments for amniotic fluid volume abnormalities with resultant improvement in clinical outcome.

  8. Geranyl diphosphate synthase molecules, and nucleic acid molecules encoding same

    Science.gov (United States)

    Croteau, Rodney Bruce; Burke, Charles Cullen

    2008-06-24

    In one aspect, the present invention provides isolated nucleic acid molecules that each encode a geranyl diphosphate synthase protein, wherein each isolated nucleic acid molecule hybridizes to a nucleic acid molecule consisting of the sequence set forth in SEQ ID NO:1 under conditions of 5.times.SSC at 45.degree. C. for one hour. The present invention also provides isolated geranyl diphosphate synthase proteins, and methods for altering the level of expression of geranyl diphosphate synthase protein in a host cell.

  9. Dynamic wetting with viscous Newtonian and non-Newtonian fluids.

    Science.gov (United States)

    Wei, Y; Rame, E; Walker, L M; Garoff, S

    2009-11-18

    We examine various aspects of dynamic wetting with viscous Newtonian and non-Newtonian fluids. Rather than concentrating on the mechanisms that relieve the classic contact line stress singularity, we focus on the behavior in the wedge flow near the contact line which has the dominant influence on wetting with these fluids. Our experiments show that a Newtonian polymer melt composed of highly flexible molecules exhibits dynamic wetting behavior described very well by hydrodynamic models that capture the critical properties of the Newtonian wedge flow near the contact line. We find that shear thinning has a strong impact on dynamic wetting, by reducing the drag of the solid on the fluid near the contact line, while the elasticity of a Boger fluid has a weaker impact on dynamic wetting. Finally, we find that other polymeric fluids, nominally Newtonian in rheometric measurements, exhibit deviations from Newtonian dynamic wetting behavior.

  10. Molecule-based magnets

    Indian Academy of Sciences (India)

    J V Yakhmi

    2009-06-01

    The conventional magnetic materials used in current technology, such as, Fe, Fe2O3, Cr2O3, SmCo5, Nd2Fe14B etc are all atom-based, and their preparation/processing require high temperature routes. Employing self-assembly methods, it is possible to engineer a bulk molecular material with long-range magnetic order, mainly because one can play with the weak intermolecular interactions. Since the first successful synthesis of molecular magnets in 1986, a large variety of them have been synthesized, which can be categorized on the basis of the chemical nature of the magnetic units involved: organic-, metal-based systems, heterobimetallic assemblies, or mixed organic–inorganic systems. The design of molecule-based magnets has also been extended to the design of poly-functional molecular magnets, such as those exhibiting second-order optical nonlinearity, liquid crystallinity, or chirality simultaneously with long-range magnetic order. Solubility, low density and biocompatibility are attractive features of molecular magnets. Being weakly coloured, unlike their opaque classical magnet ‘cousins’ listed above, possibilities of photomagnetic switching exist. Persistent efforts also continue to design the ever-elusive polymer magnets towards applications in industry. While providing a brief overview of the field of molecular magnetism, this article highlights some recent developments in it, with emphasis on a few studies from the author’s own lab.

  11. Circumstances surrounding dying in the paediatric intensive care unit

    Directory of Open Access Journals (Sweden)

    Plötz Frans B

    2006-08-01

    Full Text Available Abstract Background Death is inevitable in the paediatric intensive care unit (PICU. We aimed to describe the circumstances surrounding dying in a PICU. Method The chart records of all patients less than 18 years of age who died at the PICU between January first 2000 and July first 2005 were retrospectively analyzed. Information regarding sex, age, length of stay, admission, diagnosis, and the way a patient died was registered. Post mortem information regarding natural versus unnatural death, autopsy and donation was obtained. Non-survivors were allocated in five groups: do-not-resuscitate (DNR, withholding and/or withdrawal of therapy (W/W, failed cardiopulmonary resuscitation (failed CPR, brain death (BD, and terminal organ failure (TOF. Results During the study period 87 (4.4% of the 1995 admitted patients died. Non-survivors were more often admitted during the day (54% and the week (68%. W/W was found in 27.6%, TOF in 26.4%, BD in 23.0%, failed CPR in 18.4%, and DNR in 4.6%. Forty-three percent died in the first two days, of which BD (40.5% and failed CPR (37.8% were most common. Seventy-five children (86% died due to a natural cause. Autopsy permission was obtained in 19 of 54 patients (35%. The autopsies confirmed the clinical diagnosis in 11 patients, revealed new information in 5 patients, and in 3 patients the autopsy did not provide additional information. Nine patients were medically suitable for organ donation and 24 patients for tissue donation, whereas consent was only obtained in 2 cases in both groups. Conclusion We observed that 43% of the patients died within the first two days of admission due to BD and failed CPR, whereas after 4 days most patients died after W/W. Autopsy remains an useful tool to confirm clinical diagnoses or to provide new information. Only a small percentage of the deceased children is suitable for organ donation.

  12. Highly Enriched Uranium Metal Cylinders Surrounded by Various Reflector Materials

    Energy Technology Data Exchange (ETDEWEB)

    Bernard Jones; J. Blair Briggs; Leland Monteirth

    2007-05-01

    A series of experiments was performed at Los Alamos Scientific Laboratory in 1958 to determine critical masses of cylinders of Oralloy (Oy) reflected by a number of materials. The experiments were all performed on the Comet Universal Critical Assembly Machine, and consisted of discs of highly enriched uranium (93.3 wt.% 235U) reflected by half-inch and one-inch-thick cylindrical shells of various reflector materials. The experiments were performed by members of Group N-2, particularly K. W. Gallup, G. E. Hansen, H. C. Paxton, and R. H. White. This experiment was intended to ascertain critical masses for criticality safety purposes, as well as to compare neutron transport cross sections to those obtained from danger coefficient measurements with the Topsy Oralloy-Tuballoy reflected and Godiva unreflected critical assemblies. The reflector materials examined in this series of experiments are as follows: magnesium, titanium, aluminum, graphite, mild steel, nickel, copper, cobalt, molybdenum, natural uranium, tungsten, beryllium, aluminum oxide, molybdenum carbide, and polythene (polyethylene). Also included are two special configurations of composite beryllium and iron reflectors. Analyses were performed in which uncertainty associated with six different parameters was evaluated; namely, extrapolation to the uranium critical mass, uranium density, 235U enrichment, reflector density, reflector thickness, and reflector impurities. In addition to the idealizations made by the experimenters (removal of the platen and diaphragm), two simplifications were also made to the benchmark models that resulted in a small bias and additional uncertainty. First of all, since impurities in core and reflector materials are only estimated, they are not included in the benchmark models. Secondly, the room, support structure, and other possible surrounding equipment were not included in the model. Bias values that result from these two simplifications were determined and associated

  13. Behavioural aspects surrounding medicine purchases from pharmacies in Australia

    Directory of Open Access Journals (Sweden)

    Emmerton L

    2008-09-01

    Full Text Available Objective: This study aimed to produce current data regarding behavioural aspects of non-prescription (over-the-counter medicine purchases, in light of changes in the pharmaceutical market and increasing provision of professional services in pharmacies.Methods: Data were collected in 15 community pharmacies in South-East Queensland, Australia, over 540 hours in five days in August, 2006. The method, previously validated, involved documentation of both observational and interview data. Fifteen trained researchers were stationed in a selected pharmacy each to unobtrusively observe all eligible sales of non-prescription medicines, and, where possible, interview the purchasers post-sale. Non-response was supplemented by observational data and recall by the salesperson. The data included details of the purchase and purchasing behaviour, while new questions addressed issues of topical importance, including customers’ privacy concerns. A selection of the analyses is reported here.Results: In total, 3470 purchases were documented (135-479 per pharmacy, with customers of 67.5% of purchases (74.7% excluding an outlier pharmacy participating in the survey. Customers averaged 1.2 non-prescription medicines per transaction. Two-thirds (67.2% of customers were female, and 38.8% of the customers were aged 31-45 years. Analgesics and respiratory medicines accounted for two-thirds of the sales data (33.4% and 32.4%, respectively. Intended-brand purchases comprised 71% of purchases (2004/2824; in-store substitution then occurred in 8.8% of these cases, mainly following recommendations by pharmacy staff. Medicines intended for self-use comprised 62.9% of purchases (1752/2785. First-time purchases (30.8%, 799/2594 were more commonly influenced by pharmacy staff than by advertising.Conclusions: This study used validated methods adapted to a changing marketplace, thus providing data that both confirm and add to knowledge surrounding medicine purchases. Despite the

  14. Reliability analysis of tunnel surrounding rock stability by Monte-Carlo method

    Institute of Scientific and Technical Information of China (English)

    XI Jia-mi; YANG Geng-she

    2008-01-01

    Discussed advantages of improved Monte-Carlo method and feasibility aboutproposed approach applying in reliability analysis for tunnel surrounding rock stability. Onthe basis of deterministic parsing for tunnel surrounding rock, reliability computing methodof surrounding rock stability was derived from improved Monte-Carlo method. The com-puting method considered random of related parameters, and therefore satisfies relativityamong parameters. The proposed method can reasonably determine reliability of sur-rounding rock stability. Calculation results show that this method is a scientific method indiscriminating and checking surrounding rock stability.

  15. Clinical Observation of Vascular Dementia Treated by Surrounding-acupuncture of the CT-located Area

    Institute of Scientific and Technical Information of China (English)

    LUN Xin; FENG Bi-fang; RONG Li; YANG Wen-hui

    2003-01-01

    Purpose To observe the clinical effect of "Surrounding Needling Technigue through CT Location" in treating vascular dementia. Method Fifty cases of vascular dementia were randomly divided into surrounding Needling Technigue through CT location and routine acupuncture groups, 25 cases in each group,and were given surrounding Needling Technigue through CT location and routine acupuncture respectively. Results The effective rates in surrounding Needling Technigue through CT location and routine acupuncture groups were 88% and 60% respectively, and there was significant difference between the two groups, P < 0.01.Conclusion Therapeutic effect of surrounding Needling Technigue through CT location in treating vascular dementia was satisfactory, and better than that of routine acupuncture.

  16. Strongly interacting ultracold polar molecules

    CERN Document Server

    Gadway, Bryce

    2016-01-01

    This paper reviews recent advances in the study of strongly interacting systems of dipolar molecules. Heteronuclear molecules feature large and tunable electric dipole moments, which give rise to long-range and anisotropic dipole-dipole interactions. Ultracold samples of dipolar molecules with long-range interactions offer a unique platform for quantum simulations and the study of correlated many-body physics. We provide an introduction to the physics of dipolar quantum gases, both electric and magnetic, and summarize the multipronged efforts to bring dipolar molecules into the quantum regime. We discuss in detail the recent experimental progress in realizing and studying strongly interacting systems of polar molecules trapped in optical lattices, with particular emphasis on the study of interacting spin systems and non-equilibrium quantum magnetism. Finally, we conclude with a brief discussion of the future prospects for studies of strongly interacting dipolar molecules.

  17. Micromachined Fluid Inertial Sensors

    Directory of Open Access Journals (Sweden)

    Shiqiang Liu

    2017-02-01

    Full Text Available Micromachined fluid inertial sensors are an important class of inertial sensors, which mainly includes thermal accelerometers and fluid gyroscopes, which have now been developed since the end of the last century for about 20 years. Compared with conventional silicon or quartz inertial sensors, the fluid inertial sensors use a fluid instead of a solid proof mass as the moving and sensitive element, and thus offer advantages of simple structures, low cost, high shock resistance, and large measurement ranges while the sensitivity and bandwidth are not competitive. Many studies and various designs have been reported in the past two decades. This review firstly introduces the working principles of fluid inertial sensors, followed by the relevant research developments. The micromachined thermal accelerometers based on thermal convection have developed maturely and become commercialized. However, the micromachined fluid gyroscopes, which are based on jet flow or thermal flow, are less mature. The key issues and technologies of the thermal accelerometers, mainly including bandwidth, temperature compensation, monolithic integration of tri-axis accelerometers and strategies for high production yields are also summarized and discussed. For the micromachined fluid gyroscopes, improving integration and sensitivity, reducing thermal errors and cross coupling errors are the issues of most concern.

  18. FRACTURING FLUID CHARACTERIZATION FACILITY

    Energy Technology Data Exchange (ETDEWEB)

    Subhash Shah

    2000-08-01

    Hydraulic fracturing technology has been successfully applied for well stimulation of low and high permeability reservoirs for numerous years. Treatment optimization and improved economics have always been the key to the success and it is more so when the reservoirs under consideration are marginal. Fluids are widely used for the stimulation of wells. The Fracturing Fluid Characterization Facility (FFCF) has been established to provide the accurate prediction of the behavior of complex fracturing fluids under downhole conditions. The primary focus of the facility is to provide valuable insight into the various mechanisms that govern the flow of fracturing fluids and slurries through hydraulically created fractures. During the time between September 30, 1992, and March 31, 2000, the research efforts were devoted to the areas of fluid rheology, proppant transport, proppant flowback, dynamic fluid loss, perforation pressure losses, and frictional pressure losses. In this regard, a unique above-the-ground fracture simulator was designed and constructed at the FFCF, labeled ''The High Pressure Simulator'' (HPS). The FFCF is now available to industry for characterizing and understanding the behavior of complex fluid systems. To better reflect and encompass the broad spectrum of the petroleum industry, the FFCF now operates under a new name of ''The Well Construction Technology Center'' (WCTC). This report documents the summary of the activities performed during 1992-2000 at the FFCF.

  19. Theoretical Investigations Regarding Single Molecules

    DEFF Research Database (Denmark)

    Pedersen, Kim Georg Lind

    Neoclassical Valence Bond Theory, Quantum Transport, Quantum Interference, Kondo Effect, and Electron Pumping. Trap a single organic molecule between two electrodes and apply a bias voltage across this "molecular junction". When electrons pass through the molecule, the different electron paths can...... interfere destructively or constructively. Destructive interference effects in electron transport could potentially improve thermo-electrics, organic logic circuits and energy harvesting. We have investigated destructive interference in off-resonant transport through organic molecules, and have found a set...

  20. Applied fluid mechanics; Mecanique des fluides appliquee

    Energy Technology Data Exchange (ETDEWEB)

    Viollet, P.L.; Chabard, J.P.; Esposito, P.; Laurence, D. [Ecole Nationale des Ponts et Chaussees (ENPC), 75 - Paris (France)]|[Electricite de France (EDF), 75 - Paris (France). Direction des Etudes et Recherches

    2002-07-01

    Computational hydraulics, computational fluid dynamics, and hydro-informatics have invaded virtually all domains of research and application in hydro-science and fluids engineering. To the extent that this invasion has led to improved understanding of complex fluid phenomena and provided a frame of reference for testing and verifying designs and operational schemes, we have all benefited from it. But to the extent that it has shifted attention away from fundamental descriptions and understanding of fluid phenomena, and toward computational and numerical issues, this invasion has left avoid in the scientific and technical literature. This void exists somewhere between student exposure to first principles of solid and fluid mechanics on the one hand, and advanced-student and researcher/practitioner exposure to computational techniques and applications on the other. This new text naturally and refreshingly steps in to fill this void, and as such is a most welcome addition to the literature and to personal and institutional libraries. The text is refreshing in its innovative and careful attention to setting the historical framework of general and specific topics. This is most notable in the first chapter, which very gracefully and efficiently leads the reader through historical developments to contemporary mathematical statements of basic fluid phenomena. Once the authors have established this foundation of fundamental principles, they tie each succeeding chapter back into the introduction with appropriate and supportive historical contexts. Although the text does not shy away from rigorous analytical descriptions of fluid phenomena, it is unique in providing this delightful historical context for each topic. The authors have also made a special effort to tie the chapters together into a unified whole, with ample references forward and back; this is indeed rare, and much appreciated, in a text of multiple authorship. The topics treated and chapter structures reflect

  1. Fundamentals of fluid lubrication

    Science.gov (United States)

    Hamrock, Bernard J.

    1991-01-01

    The aim is to coordinate the topics of design, engineering dynamics, and fluid dynamics in order to aid researchers in the area of fluid film lubrication. The lubrication principles that are covered can serve as a basis for the engineering design of machine elements. The fundamentals of fluid film lubrication are presented clearly so that students that use the book will have confidence in their ability to apply these principles to a wide range of lubrication situations. Some guidance on applying these fundamentals to the solution of engineering problems is also provided.

  2. Supercritical fluid extraction

    Science.gov (United States)

    Wai, Chien M.; Laintz, Kenneth

    1994-01-01

    A method of extracting metalloid and metal species from a solid or liquid material by exposing the material to a supercritical fluid solvent containing a chelating agent. The chelating agent forms chelates that are soluble in the supercritical fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is a fluorinated or lipophilic crown ether or fluorinated dithiocarbamate. The method provides an environmentally benign process for removing contaminants from industrial waste without using acids or biologically harmful solvents. The chelate and supercritical fluid can be regenerated, and the contaminant species recovered, to provide an economic, efficient process.

  3. Geophysical fluid flow experiment

    Science.gov (United States)

    Broome, B. G.; Fichtl, G.; Fowlis, W.

    1979-01-01

    The essential fluid flow processes associated with the solar and Jovian atmospheres will be examined in a laboratory experiment scheduled for performance on Spacelab Missions One and Three. The experimental instrumentation required to generate and to record convective fluid flow is described. Details of the optical system configuration, the lens design, and the optical coatings are described. Measurement of thermal gradient fields by schlieren techniques and measurement of fluid flow velocity fields by photochromic dye tracers is achieved with a common optical system which utilizes photographic film for data recording. Generation of the photochromic dye tracers is described, and data annotation of experimental parameters on the film record is discussed.

  4. Synthetic Base Fluids

    Science.gov (United States)

    Brown, M.; Fotheringham, J. D.; Hoyes, T. J.; Mortier, R. M.; Orszulik, S. T.; Randles, S. J.; Stroud, P. M.

    The chemical nature and technology of the main synthetic lubricant base fluids is described, covering polyalphaolefins, alkylated aromatics, gas-to-liquid (GTL) base fluids, polybutenes, aliphatic diesters, polyolesters, polyalkylene glycols or PAGs and phosphate esters.Other synthetic lubricant base oils such as the silicones, borate esters, perfluoroethers and polyphenylene ethers are considered to have restricted applications due to either high cost or performance limitations and are not considered here.Each of the main synthetic base fluids is described for their chemical and physical properties, manufacture and production, their chemistry, key properties, applications and their implications when used in the environment.

  5. STM investigation of surfactant molecules

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Adsorption and self-organization of sodium alkyl sulfonates (STS and SHS) have been studied on HOPG by using the in situ scanning tunneling microscopy (STM). Both SHS and STS molecules adsorb on the HOPG surface and form long-range well-ordered monolayers. The neighboring molecules in different rows form a "head to head" configuration. In the high-resolution images of STS and SHS molecules, one end of the molecules shows bright spots which are attributed to the SO3- groups.

  6. Biofuels: from microbes to molecules

    National Research Council Canada - National Science Library

    Lu, Xuefeng

    2014-01-01

    .... The production of different biofuel molecules including hydrogen, methane, ethanol, butanol, higher chain alcohols, isoprenoids and fatty acid derivatives, from genetically engineered microbes...

  7. Selection of Prebiotic Molecules in Amphiphilic Environments

    Directory of Open Access Journals (Sweden)

    Christian Mayer

    2017-01-01

    Full Text Available A basic problem in all postulated pathways of prebiotic chemistry is the low concentration which generally is expected for interesting reactants in fluid environments. Even though compounds, like nucleobases, sugars or peptides, principally may form spontaneously under environmental conditions, they will always be rapidly diluted in an aqueous environment. In addition, any such reaction leads to side products which often exceed the desired compound and generally hamper the first steps of a subsequent molecular evolution. Therefore, a mechanism of selection and accumulation of relevant prebiotic compounds seems to be crucial for molecular evolution. A very efficient environment for selection and accumulation can be found in the fluid continuum circulating in tectonic fault zones. Vesicles which form spontaneously at a depth of approximately 1 km present a selective trap for amphiphilic molecules, especially for peptides composed of hydrophilic and hydrophobic amino acids in a suitable sequence. The accumulation effect is shown in a numeric simulation on a simplified model. Further, possible mechanisms of a molecular evolution in vesicle membranes are discussed. Altogether, the proposed scenario can be seen as an ideal environment for constant, undisturbed molecular evolution in and on cell-like compartments.

  8. The Stability and Dynamics of Elastic Structures and Fluid Flows.

    Science.gov (United States)

    1985-03-01

    Pol- Duffing oscillators . For special values of the detuning parameters the secondary states are periodic. Then periodic multiplication of solutions...incident wave is near a resonant frequency, the target oscillates and its interaction with the surrounding fluid produces peaks in the scattered field...slightly damped, and oscillating outgoing spherical waves that represent the "decayed ringing" of the membrane. Application is given to the baffled circular

  9. Peritoneal Fluid Analysis

    Science.gov (United States)

    ... Peritoneal fluid glucose, amylase, tumor markers, bilirubin, creatinine, lactate dehydrogenase (LD) Microscopic examination – may be performed if infection or cancer is suspected; a laboratory professional may use a ...

  10. Culture - joint fluid

    Science.gov (United States)

    Joint fluid culture ... fungi, or viruses grow. This is called a culture. If these germs are detected, other tests may ... is no special preparation needed for the lab culture. How to prepare for the removal of joint ...

  11. Polymer Fluid Dynamics.

    Science.gov (United States)

    Bird, R. Byron

    1980-01-01

    Problems in polymer fluid dynamics are described, including development of constitutive equations, rheometry, kinetic theory, flow visualization, heat transfer studies, flows with phase change, two-phase flow, polymer unit operations, and drag reduction. (JN)

  12. Nonpolluting drilling fluid composition

    Energy Technology Data Exchange (ETDEWEB)

    Larson, D.E.; Mocek, C.J.; Mouton, R.J.

    1983-02-22

    Disclosed is a nonpolluting drilling fluid composition. The composition mixture consisting essentially of a concentrate and any nonpolluting oil. The concentrate consists essentially of diethanolamide, a fatty acid, and a imidazoline/amide mixture.

  13. Cerebrospinal fluid (CSF) culture

    Science.gov (United States)

    ... is a laboratory test to look for bacteria, fungi, and viruses in the fluid that moves in ... culture medium. Laboratory staff then observe if bacteria, fungi, or viruses grow in the dish. Growth means ...

  14. Conjugate Compressible Fluid Flow and Heat Transfer in Ducts

    Science.gov (United States)

    Cross, M. F.

    2011-01-01

    A computational approach to modeling transient, compressible fluid flow with heat transfer in long, narrow ducts is presented. The primary application of the model is for analyzing fluid flow and heat transfer in solid propellant rocket motor nozzle joints during motor start-up, but the approach is relevant to a wide range of analyses involving rapid pressurization and filling of ducts. Fluid flow is modeled through solution of the spatially one-dimensional, transient Euler equations. Source terms are included in the governing equations to account for the effects of wall friction and heat transfer. The equation solver is fully-implicit, thus providing greater flexibility than an explicit solver. This approach allows for resolution of pressure wave effects on the flow as well as for fast calculation of the steady-state solution when a quasi-steady approach is sufficient. Solution of the one-dimensional Euler equations with source terms significantly reduces computational run times compared to general purpose computational fluid dynamics packages solving the Navier-Stokes equations with resolved boundary layers. In addition, conjugate heat transfer is more readily implemented using the approach described in this paper than with most general purpose computational fluid dynamics packages. The compressible flow code has been integrated with a transient heat transfer solver to analyze heat transfer between the fluid and surrounding structure. Conjugate fluid flow and heat transfer solutions are presented. The author is unaware of any previous work available in the open literature which uses the same approach described in this paper.

  15. Single molecule force measurements of perlecan/HSPG2: A key component of the osteocyte pericellular matrix.

    Science.gov (United States)

    Wijeratne, Sithara S; Martinez, Jerahme R; Grindel, Brian J; Frey, Eric W; Li, Jingqiang; Wang, Liyun; Farach-Carson, Mary C; Kiang, Ching-Hwa

    2016-03-01

    Perlecan/HSPG2, a large, monomeric heparan sulfate proteoglycan (HSPG), is a key component of the lacunar canalicular system (LCS) of cortical bone, where it is part of the mechanosensing pericellular matrix (PCM) surrounding the osteocytic processes and serves as a tethering element that connects the osteocyte cell body to the bone matrix. Within the pericellular space surrounding the osteocyte cell body, perlecan can experience physiological fluid flow drag force and in that capacity function as a sensor to relay external stimuli to the osteocyte cell membrane. We previously showed that a reduction in perlecan secretion alters the PCM fiber composition and interferes with bone's response to a mechanical loading in vivo. To test our hypothesis that perlecan core protein can sustain tensile forces without unfolding under physiological loading conditions, atomic force microscopy (AFM) was used to capture images of perlecan monomers at nanoscale resolution and to perform single molecule force measurement (SMFMs). We found that the core protein of purified full-length human perlecan is of suitable size to span the pericellular space of the LCS, with a measured end-to-end length of 170±20 nm and a diameter of 2-4 nm. Force pulling revealed a strong protein core that can withstand over 100 pN of tension well over the drag forces that are estimated to be exerted on the individual osteocyte tethers. Data fitting with an extensible worm-like chain model showed that the perlecan protein core has a mean elastic constant of 890 pN and a corresponding Young's modulus of 71 MPa. We conclude that perlecan has physical properties that would allow it to act as a strong but elastic tether in the LCS.

  16. Influence of surrounding structures upon the aerodynamic and acoustic performance of the outdoor unit of a split air-conditioner

    Science.gov (United States)

    Wu, Chengjun; Liu, Jiang; Pan, Jie

    2014-07-01

    DC-inverter split air-conditioner is widely used in Chinese homes as a result of its high-efficiency and energy-saving. Recently, the researches on its outdoor unit have focused on the influence of surrounding structures upon the aerodynamic and acoustic performance, however they are only limited to the influence of a few parameters on the performance, and practical design of the unit requires more detailed parametric analysis. Three-dimensional computational fluid dynamics(CFD) and computational aerodynamic acoustics(CAA) simulation based on FLUENT solver is used to study the influence of surrounding structures upon the aforementioned properties of the unit. The flow rate and sound pressure level are predicted for different rotating speed, and agree well with the experimental results. The parametric influence of three main surrounding structures(i.e. the heat sink, the bell-mouth type shroud and the outlet grille) upon the aerodynamic performance of the unit is analyzed thoroughly. The results demonstrate that the tip vortex plays a major role in the flow fields near the blade tip and has a great effect on the flow field of the unit. The inlet ring's size and throat's depth of the bell-mouth type shroud, and the through-flow area and configuration of upwind and downwind sections of the outlet grille are the most important factors that affect the aerodynamic performance of the unit. Furthermore, two improved schemes against the existing prototype of the unit are developed, which both can significantly increase the flow rate more than 6 %(i.e. 100 m3·h-1) at given rotating speeds. The inevitable increase of flow noise level when flow rate is increased and the advantage of keeping a lower rotating speed are also discussed. The presented work could be a useful guideline in designing the aerodynamic and acoustic performance of the split air-conditioner in engineering practice.

  17. [Diagnosis: synovial fluid analysis].

    Science.gov (United States)

    Gallo Vallejo, Francisco Javier; Giner Ruiz, Vicente

    2014-01-01

    Synovial fluid analysis in rheumatological diseases allows a more accurate diagnosis in some entities, mainly infectious and microcrystalline arthritis. Examination of synovial fluid in patients with osteoarthritis is useful if a differential diagnosis will be performed with other processes and to distinguish between inflammatory and non-inflammatory forms. Joint aspiration is a diagnostic and sometimes therapeutic procedure that is available to primary care physicians. Copyright © 2014 Elsevier España, S.L. All rights reserved.

  18. Conventional cerebrospinal fluid scanning

    Energy Technology Data Exchange (ETDEWEB)

    Schicha, H.

    1985-06-01

    Conventional cerebrospinal fluid scanning (CSF scanning) today is mainly carried out in addition to computerized tomography to obtain information about liquor flow kinetics. Especially in patients with communicating obstructive hydrocephalus, CSF scanning is clinically useful for the decision for shunt surgery. In patients with intracranial cysts, CSF scanning can provide information about liquor circulation. Further indications for CSF scanning include the assessment of shunt patency especially in children, as well as the detection and localization of cerebrospinal fluid leaks.

  19. Students' Use of Three Different Visual Representations to Interpret Whether Molecules Are Polar or Nonpolar

    Science.gov (United States)

    Host, Gunnar E.; Schonborn, Konrad J.; Palmerius, Karljohan E. Lundin

    2012-01-01

    Visualizing molecular properties is often crucial for constructing conceptual understanding in chemistry. However, research has revealed numerous challenges surrounding students' meaningful interpretation of the relationship between the geometry and electrostatic properties of molecules. This study explored students' (n = 18) use of three visual…

  20. Students' Use of Three Different Visual Representations to Interpret Whether Molecules Are Polar or Nonpolar

    Science.gov (United States)

    Host, Gunnar E.; Schonborn, Konrad J.; Palmerius, Karljohan E. Lundin

    2012-01-01

    Visualizing molecular properties is often crucial for constructing conceptual understanding in chemistry. However, research has revealed numerous challenges surrounding students' meaningful interpretation of the relationship between the geometry and electrostatic properties of molecules. This study explored students' (n = 18) use of three visual…

  1. The Neural Cell Adhesion Molecule NCAM2/OCAM/RNCAM, a Close Relative to NCAM

    DEFF Research Database (Denmark)

    Kulahin, Nikolaj; Walmod, Peter

    2008-01-01

    Cell adhesion molecules (CAMs) constitute a large class of plasma membrane-anchored proteins that mediate attachment between neighboring cells and between cells and the surrounding extracellular matrix (ECM). However, CAMs are more than simple mediators of cell adhesion. The neural cell adhesion ...

  2. Inhibition of the dorsal premotor cortex does not repair surround inhibition in writer's cramp patients.

    Science.gov (United States)

    Veugen, Lidwien C; Hoffland, Britt S; Stegeman, Dick F; van de Warrenburg, Bart P

    2013-03-01

    Writer's cramp is a task-specific form of focal dystonia, characterized by abnormal movements and postures of the hand and arm during writing. Two consistent abnormalities in its pathophysiology are a loss of surround inhibition and overactivity of the dorsal premotor cortex (PMd). This study aimed to assess a possible link between these two phenomena by investigating whether PMd inhibition leads to an improvement of surround inhibition, in parallel with previously demonstrated writing improvement. Fifteen writer's cramp patients and ten controls performed a simple motor hand task during which surround inhibition was measured using transcranial magnetic stimulation. Motor cortical excitability was measured of the active and surround muscles at three phases of the task. Surround inhibition and writing performance were assessed before and after PMd inhibitory continuous theta burst stimulation. In contrast to healthy controls, patients did not show inhibition of the abductor digiti minimi muscle during movement initiation of the first dorsal interosseus muscle, confirming the loss of surround inhibition. PMd inhibition led to an improvement of writing speed in writer's cramp patients. However, in both groups, no changes in surround inhibition were observed. The results confirm a role for the PMd in the pathophysiology of writer's cramp. We show that PMd inhibition does not lead to restoration of the surround inhibition defect in writer's cramp, despite the improvement in writing. This questions the involvement of the PMd in the loss of surround inhibition, and perhaps also the direct link between surround inhibition and dystonia.

  3. Search for organic molecules in the outer solar system.

    Science.gov (United States)

    Encrenaz, T h

    1986-01-01

    Recent developments of millimeter astronomy have led to the discovery of more and more complex molecules in the interstellar medium. In a similar way, attempts have been made to detect complex molecules in the atmospheres of the most primitive bodies of the Solar System, i.e. outer planets and comets, as well as in Titan's atmosphere. An important progress has been achieved thanks to the continuous development of infrared astronomy, from the ground and from space vehicles. In particular, an important contribution has come from the IRIS-Voyager infrared spectrometer with the detection of prebiotic molecules on Titan, and some complex organic molecules on Jupiter and Saturn. Another important result has been the observation of carbonaceous material in the immediate surroundings of Comet Halley's nucleus. In the near future, the search for organic molecules in the outer Solar System should benefit from the developments of large millimeter antennae, and in the next decade, from the operation of infrared Earth-orbiting spacecrafts (ISO, SIRTF).

  4. Fullerol ionic fluids

    KAUST Repository

    Fernandes, Nikhil

    2010-01-01

    We report for the first time an ionic fluid based on hydroxylated fullerenes (fullerols). The ionic fluid was synthesized by neutralizing the fully protonated fullerol with an amine terminated polyethylene/polypropylene oxide oligomer (Jeffamine®). The ionic fluid was compared to a control synthesized by mixing the partially protonated form (sodium form) of the fullerols with the same oligomeric amine in the same ratio as in the ionic fluids (20 wt% fullerol). In the fullerol fluid the ionic bonding significantly perturbs the thermal transitions and melting/crystallization behavior of the amine. In contrast, both the normalized heat of fusion and crystallization of the amine in the control are similar to those of the neat amine consistent with a physical mixture of the fullerols/amine with minimal interactions. In addition to differences in thermal behavior, the fullerol ionic fluid exhibits a complex viscoelastic behavior intermediate between the neat Jeffamine® (liquid-like) and the control (solid-like). © 2010 The Royal Society of Chemistry.

  5. Micro-Kelvin cold molecules.

    Energy Technology Data Exchange (ETDEWEB)

    Strecker, Kevin E.; Chandler, David W.

    2009-10-01

    We have developed a novel experimental technique for direct production of cold molecules using a combination of techniques from atomic optical and molecular physics and physical chemistry. The ability to produce samples of cold molecules has application in a broad spectrum of technical fields high-resolution spectroscopy, remote sensing, quantum computing, materials simulation, and understanding fundamental chemical dynamics. Researchers around the world are currently exploring many techniques for producing samples of cold molecules, but to-date these attempts have offered only limited success achieving milli-Kelvin temperatures with low densities. This Laboratory Directed Research and Development project is to develops a new experimental technique for producing micro-Kelvin temperature molecules via collisions with laser cooled samples of trapped atoms. The technique relies on near mass degenerate collisions between the molecule of interest and a laser cooled (micro-Kelvin) atom. A subset of collisions will transfer all (nearly all) of the kinetic energy from the 'hot' molecule, cooling the molecule at the expense of heating the atom. Further collisions with the remaining laser cooled atoms will thermally equilibrate the molecules to the micro-Kelvin temperature of the laser-cooled atoms.

  6. Theoretical Investigations Regarding Single Molecules

    DEFF Research Database (Denmark)

    Pedersen, Kim Georg Lind

    Neoclassical Valence Bond Theory, Quantum Transport, Quantum Interference, Kondo Effect, and Electron Pumping. Trap a single organic molecule between two electrodes and apply a bias voltage across this "molecular junction". When electrons pass through the molecule, the different electron paths can...

  7. Triatomic molecules laser-cooled

    Science.gov (United States)

    2017-06-01

    Molecules containing three atoms have been laser-cooled to ultracold temperatures for the first time. John Doyle and colleagues at Harvard University in the US used a technique called Sisyphus cooling to chill an ensemble of about a million strontium-monohydroxide molecules to 750 μK.

  8. PREDICTION OF THERMODYNAMIC PROPERTIES OF COMPLEX FLUIDS

    Energy Technology Data Exchange (ETDEWEB)

    Marc Donohue

    2006-01-05

    ABSTRACT The goal of this research has been to generalize Density Functional Theory (DFT) for complex molecules, i.e. molecules whose size, shape, and interaction energies cause them to show significant deviations from mean-field behavior. We considered free energy functionals and minimized them for systems with different geometries and dimensionalities including confined fluids (such as molecular layers on surfaces and molecules in nano-scale pores), systems with directional interactions and order-disorder transitions, amphiphilic dimers, block copolymers, and self-assembled nano-structures. The results of this procedure include equations of equilibrium for these systems and the development of computational tools for predicting phase transitions and self-assembly in complex fluids. DFT was developed for confined fluids. A new phenomenon, surface compression of confined fluids, was predicted theoretically and confirmed by existing experimental data and by simulations. The strong attraction to a surface causes adsorbate molecules to attain much higher densities than that of a normal liquid. Under these conditions, adsorbate molecules are so compressed that they repel each other. This phenomenon is discussed in terms of experimental data, results of Monte Carlo simulations, and theoretical models. Lattice version of DFT was developed for modeling phase transitions in adsorbed phase including wetting, capillary condensation, and ordering. Phase behavior of amphiphilic dimers on surfaces and in solutions was modeled using lattice DFT and Monte Carlo simulations. This study resulted in predictive models for adsorption isotherms and for local density distributions in solutions. We have observed a wide variety of phase behavior for amphiphilic dimers, including formation of lamellae and micelles. Block copolymers were modeled in terms of configurational probabilities and in the approximation of random mixing entropy. Probabilities of different orientations for the

  9. Conserved linear dynamics of single-molecule Brownian motion

    KAUST Repository

    Serag, Maged F.

    2017-06-06

    Macromolecular diffusion in homogeneous fluid at length scales greater than the size of the molecule is regarded as a random process. The mean-squared displacement (MSD) of molecules in this regime increases linearly with time. Here we show that non-random motion of DNA molecules in this regime that is undetectable by the MSD analysis can be quantified by characterizing the molecular motion relative to a latticed frame of reference. Our lattice occupancy analysis reveals unexpected sub-modes of motion of DNA that deviate from expected random motion in the linear, diffusive regime. We demonstrate that a subtle interplay between these sub-modes causes the overall diffusive motion of DNA to appear to conform to the linear regime. Our results show that apparently random motion of macromolecules could be governed by non-random dynamics that are detectable only by their relative motion. Our analytical approach should advance broad understanding of diffusion processes of fundamental relevance.

  10. Enzyme molecules in solitary confinement.

    Science.gov (United States)

    Liebherr, Raphaela B; Gorris, Hans H

    2014-09-12

    Large arrays of homogeneous microwells each defining a femtoliter volume are a versatile platform for monitoring the substrate turnover of many individual enzyme molecules in parallel. The high degree of parallelization enables the analysis of a statistically representative enzyme population. Enclosing individual enzyme molecules in microwells does not require any surface immobilization step and enables the kinetic investigation of enzymes free in solution. This review describes various microwell array formats and explores their applications for the detection and investigation of single enzyme molecules. The development of new fabrication techniques and sensitive detection methods drives the field of single molecule enzymology. Here, we introduce recent progress in single enzyme molecule analysis in microwell arrays and discuss the challenges and opportunities.

  11. Enzyme Molecules in Solitary Confinement

    Directory of Open Access Journals (Sweden)

    Raphaela B. Liebherr

    2014-09-01

    Full Text Available Large arrays of homogeneous microwells each defining a femtoliter volume are a versatile platform for monitoring the substrate turnover of many individual enzyme molecules in parallel. The high degree of parallelization enables the analysis of a statistically representative enzyme population. Enclosing individual enzyme molecules in microwells does not require any surface immobilization step and enables the kinetic investigation of enzymes free in solution. This review describes various microwell array formats and explores their applications for the detection and investigation of single enzyme molecules. The development of new fabrication techniques and sensitive detection methods drives the field of single molecule enzymology. Here, we introduce recent progress in single enzyme molecule analysis in microwell arrays and discuss the challenges and opportunities.

  12. Recent developments of mathematical fluid mechanics

    CERN Document Server

    Giga, Yoshikazu; Kozono, Hideo; Okamoto, Hisashi; Yamazaki, Masao

    2016-01-01

    The book addresses recent developments of the mathematical research on the Navier-Stokes and Euler equations as well as on related problems. In particular, there are covered:   1) existence, uniqueness, and the regularity of weak solutions; 2) stability of the motion in rest and the asymptotic behavior of solutions; 3) singularity and blow-up of weak and strong solutions; 4) vorticity and energy conservation; 5) motions of rotating fluids, or of fluids surrounding a rotating body; 6) free boundary problems; 7) maximal regularity theory and other abstract results for mathematical fluid mechanics.   For this quarter century, these topics have been playing a central role in both pure and applied mathematics and having a great influence to the developm ent of the functional analysis, harmonic analysis and numerical analysis whose tools make a a substantial contribution to the investigation of nonlinear partial differential equations, particularly the Navier-Stokes and the Euler equations.      There are 24...

  13. Viscous Flow with Large Fluid-Fluid Interface Displacement

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Koblitz; Hassager, Ole; Saasen, Arild

    1998-01-01

    The arbitrary Lagrange-Euler (ALE) kinematic description has been implemented in a 3D transient finite element program to simulate multiple fluid flows with fluid-fluid interface or surface displacements. The description of fluid interfaces includes variable interfacial tension, and the formulation...

  14. A new look at cerebrospinal fluid circulation.

    Science.gov (United States)

    Brinker, Thomas; Stopa, Edward; Morrison, John; Klinge, Petra

    2014-01-01

    According to the traditional understanding of cerebrospinal fluid (CSF) physiology, the majority of CSF is produced by the choroid plexus, circulates through the ventricles, the cisterns, and the subarachnoid space to be absorbed into the blood by the arachnoid villi. This review surveys key developments leading to the traditional concept. Challenging this concept are novel insights utilizing molecular and cellular biology as well as neuroimaging, which indicate that CSF physiology may be much more complex than previously believed. The CSF circulation comprises not only a directed flow of CSF, but in addition a pulsatile to and fro movement throughout the entire brain with local fluid exchange between blood, interstitial fluid, and CSF. Astrocytes, aquaporins, and other membrane transporters are key elements in brain water and CSF homeostasis. A continuous bidirectional fluid exchange at the blood brain barrier produces flow rates, which exceed the choroidal CSF production rate by far. The CSF circulation around blood vessels penetrating from the subarachnoid space into the Virchow Robin spaces provides both a drainage pathway for the clearance of waste molecules from the brain and a site for the interaction of the systemic immune system with that of the brain. Important physiological functions, for example the regeneration of the brain during sleep, may depend on CSF circulation.

  15. Numerical analysis of tunnel reinforcing influences on failure process of surrounding rock under explosive stress waves

    Institute of Scientific and Technical Information of China (English)

    ZUO Yu-jun; TANG Chun-an; ZHU Wan-cheng; LI Di-yuan; LI Shu-cai

    2008-01-01

    Based on mesoscopic damage mechanics, numerical code RFPA2D (dynamic edition) was developed to analyze the influence of tunnel reinforcing on failure process of surrounding rock under explosive stress waves. The results show that the propagation phenomenon of stress wave in the surrounding rock of tunnel and the failure process of surrounding rock under explosive stress waves are reproduced realistically by using numerical code RFPAED; from the failure process of surrounding rock,the place at which surrounding rock fractures is transferred because of tunnel reinforcing, and the rockfall and collapse caused by failure of surrounding rock are restrained by tunnel reinforcing; furthermore, the absolute values of peak values of major principal stress, and the minimal principal stress and shear stress at center point of tunnel roof are reduced because of tunnel reinforcing, and the displacement at center point of tunnel roof is reduced as well, consequently the stability of tunnel increases.

  16. Two-phase cooling fluids; Les fluides frigoporteurs diphasiques

    Energy Technology Data Exchange (ETDEWEB)

    Lallemand, A. [Institut National des Sciences Appliquees (INSA), 69 - Lyon (France)

    1997-12-31

    In the framework of the diminution of heat transfer fluid consumption, the concept of indirect refrigerating circuits, using cooling intermediate fluids, is reviewed and the fluids that are currently used in these systems are described. Two-phase cooling fluids advantages over single-phase fluids are presented with their thermophysical characteristics: solid fraction, two-phase mixture enthalpy, thermal and rheological properties, determination of heat and mass transfer characteristics, and cold storage through ice slurry

  17. Spontaneous rupture of pedunculate gastric gastrointestinal stromal tumor into the gastrocelic ligament presenting as a stalked mass surrounded by loculated hematoma

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Soo; Ahn, Sung Eun; Park, Seong Jin; Moon, Sung Kyoung; Lim, Joo Won; Lee, Dong Ho; Kim, Yong Ho [Kyung Hee University Medical Center, Kyung Hee University School of Medicine, Seoul (Korea, Republic of)

    2015-04-15

    Gastric gastrointestinal stromal tumor (GIST) is one of the most common mesenchymal tumors of the stomach, which may be asymptomatic or cause symptoms such as pain, gastrointestinal bleeding, and obstruction. Hemoperitoneum due to spontaneous rupture of the tumor is an extremely rare complication. We described a case of a 52-year-old man with a large pedunculated GIST causing loculated hematoma within the gastrocolic ligament. The patient visited our hospital due to a 3 week history of epigastric pain. A computed tomography scan revealed a 10.3 x 7.5 x 9.4 cm sized mass that was growing exophytically from the greater curvature of the stomach and was surrounded by loculated hematoma within the gastrocolic ligament. Laparotomy revealed a large stalked gastric mass surrounded by loculated hematoma within the gastrocolic ligament and blood fluid in the peritoneal cavity. Pathologic examination confirmed a GIST, of the high risk group.

  18. Single Molecule Electronics and Devices

    Directory of Open Access Journals (Sweden)

    Makusu Tsutsui

    2012-05-01

    Full Text Available The manufacture of integrated circuits with single-molecule building blocks is a goal of molecular electronics. While research in the past has been limited to bulk experiments on self-assembled monolayers, advances in technology have now enabled us to fabricate single-molecule junctions. This has led to significant progress in understanding electron transport in molecular systems at the single-molecule level and the concomitant emergence of new device concepts. Here, we review recent developments in this field. We summarize the methods currently used to form metal-molecule-metal structures and some single-molecule techniques essential for characterizing molecular junctions such as inelastic electron tunnelling spectroscopy. We then highlight several important achievements, including demonstration of single-molecule diodes, transistors, and switches that make use of electrical, photo, and mechanical stimulation to control the electron transport. We also discuss intriguing issues to be addressed further in the future such as heat and thermoelectric transport in an individual molecule.

  19. The cross-correlation of signals and spatial impression in surround sound reproduction

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The relationship between the cross-correlation coefficients of feeding signals and auditory spatial impression(ASI) which are created by the left,right,left surround and right surround loudspeakers in 5.1 channel surround sound system is investigated by psychoacoustic experiments.The results show that for reproducing by the front left-right or left-right surround loudspeakers pair,the auditory source width(ASW) can be broadened by controlling the crosscorrelation coefficients of feeding signals to some e...

  20. Boiler using combustible fluid

    Science.gov (United States)

    Baumgartner, H.; Meier, J.G.

    1974-07-03

    A fluid fuel boiler is described comprising a combustion chamber, a cover on the combustion chamber having an opening for introducing a combustion-supporting gaseous fluid through said openings, means to impart rotation to the gaseous fluid about an axis of the combustion chamber, a burner for introducing a fluid fuel into the chamber mixed with the gaseous fluid for combustion thereof, the cover having a generally frustro-conical configuration diverging from the opening toward the interior of the chamber at an angle of between 15/sup 0/ and 55/sup 0/; means defining said combustion chamber having means defining a plurality of axial hot gas flow paths from a downstream portion of the combustion chamber to flow hot gases into an upstream portion of the combustion chamber, and means for diverting some of the hot gas flow along paths in a direction circumferentially of the combustion chamber, with the latter paths being immersed in the water flow path thereby to improve heat transfer and terminating in a gas outlet, the combustion chamber comprising at least one modular element, joined axially to the frustro-conical cover and coaxial therewith. The modular element comprises an inner ring and means of defining the circumferential, radial, and spiral flow paths of the hot gases.

  1. Amniotic fluid embolism

    Directory of Open Access Journals (Sweden)

    Kiranpreet Kaur

    2016-01-01

    Full Text Available Amniotic fluid embolism (AFE is one of the catastrophic complications of pregnancy in which amniotic fluid, fetal cells, hair, or other debris enters into the maternal pulmonary circulation, causing cardiovascular collapse. Etiology largely remains unknown, but may occur in healthy women during labour, during cesarean section, after abnormal vaginal delivery, or during the second trimester of pregnancy. It may also occur up to 48 hours post-delivery. It can also occur during abortion, after abdominal trauma, and during amnio-infusion. The pathophysiology of AFE is not completely understood. Possible historical cause is that any breach of the barrier between maternal blood and amniotic fluid forces the entry of amniotic fluid into the systemic circulation and results in a physical obstruction of the pulmonary circulation. The presenting signs and symptoms of AFE involve many organ systems. Clinical signs and symptoms are acute dyspnea, cough, hypotension, cyanosis, fetal bradycardia, encephalopathy, acute pulmonary hypertension, coagulopathy etc. Besides basic investigations lung scan, serum tryptase levels, serum levels of C3 and C4 complements, zinc coproporphyrin, serum sialyl Tn etc are helpful in establishing the diagnosis. Treatment is mainly supportive, but exchange transfusion, extracorporeal membrane oxygenation, and uterine artery embolization have been tried from time to time. The maternal prognosis after amniotic fluid embolism is very poor though infant survival rate is around 70%.

  2. A Survey of Deepwater Horizon (DWH Oil-Degrading Bacteria from the Eastern Oyster Biome and its Surrounding Environment

    Directory of Open Access Journals (Sweden)

    Jesse eThomas

    2014-04-01

    Full Text Available The Deepwater Horizon (DWH accident led to the release of an estimated 794,936,474 liters of crude oil into the northern Gulf of Mexico over an 85 day period in 2010, resulting in the contamination of the Gulf of Mexico waters, sediments, permeable beach sands, coastal wetlands and marine life. This study examines the potential response of the Eastern oyster’s microbiome to hydrocarbon contamination and compares it with the bacterial community responses observed from the overlaying water column and the oyster bed sediments. For this purpose, microcosms seeded with DWH crude oil were established and inoculated separately with oyster tissue (OT, mantle fluid (MF, overlaying water column (WC and sediments (S collected from Apalachicola Bay, FL. Shifts in the microbial community structure in the amended microcosms was monitored over a 3-month period using automated ribosomal intergenic spacer region analysis (ARISA, which showed that the microbiome of the oyster tissue and mantle fluid were more similar to the sediment communities than those present in the overlaying water column. This pattern remained largely consistent, regardless of the concentration of crude oil or the enrichment period. Additionally, 72 oil-degrading bacteria were isolated from the microcosms containing OT, MF, WC and S and identified using 16S ribosomal RNA (rRNA gene sequencing and compared by principal component analysis (PCA which clearly showed that the water column isolates were different to those identified from the sediment. Conversely, the oyster tissue and mantle fluid isolates clustered together; a strong indication that the oyster microbiome is uniquely structured relative to its surrounding environment. When selected isolates from the OT, MF, WC and S were assessed for their oil-degrading potential, we found that the DWH oil was biodegraded between 12%-42%, under the existing conditions.

  3. When water molecules meet air

    OpenAIRE

    Hsie, Cho-Shuen; Campen, R. Kramer; Verde, Ana Vila; Bolhuis, Peter; Nienhuys, Han-Kwang; Bonn, Mischa

    2012-01-01

    About 70% of our planet is covered in water. Most of that water exists as water in the bulk – the neighbors of water molecules are other water molecules – and only a small fraction of molecules are at the air-water interface. Despite the small relative abundance of interfacial water, it is of the utmost importance: it governs the chemistry involving the surface of oceans and seawater aerosols, or the small water droplets forming clouds. Reactions at the air-water interface are directly releva...

  4. Fluid intelligence loss linked to restricted regions of damage within frontal and parietal cortex

    OpenAIRE

    Woolgar, Alexandra; Parr, Alice; Cusack, Rhodri; Thompson, Russell; Nimmo-Smith, Ian; Torralva, Teresa; Roca, Maria; Antoun, Nagui; Manes, Facundo; Duncan, John

    2010-01-01

    Tests of fluid intelligence predict success in a wide range of cognitive activities. Much uncertainty has surrounded brain lesions producing deficits in these tests, with standard group comparisons delivering no clear result. Based on findings from functional imaging, we propose that the uncertainty of lesion data may arise from the specificity and complexity of the relevant neural circuit. Fluid intelligence tests give a characteristic pattern of activity in posterolateral frontal, dorsomedi...

  5. Comparison of Socioeconomic Factors between Surrounding and Non-Surrounding Areas of the Qinghai–Tibet Railway before and after Its Construction

    Directory of Open Access Journals (Sweden)

    Shicheng Li

    2016-08-01

    Full Text Available As the world’s highest railway, and the longest highland railway, the Qinghai–Tibet Railway (QTR has been paid considerable attention by researchers. However, most attention has been paid to the ecological and environmental issues affecting it, and sustainable ecological, social, and economic development-related studies of the QTR are rare. In this study, by analyzing the passenger traffic, freight traffic, passenger-kilometers, and freight-kilometers of the QTR for the period 1982–2013 and the transport structure of the Tibetan Plateau (TP for 1990–2013, the evolutionary process of the transport system in the TP following the construction of the QTR has been revealed. Subsequently, by comparing Gross Domestic Product (GDP, population, industrial structure, and urbanization level at the county and 1 km scales between surrounding and non-surrounding areas of the QTR, the differences in socioeconomic performance before and after its construction were detected. The results show that (1 in the TP, the highway-dominated transport system will break up and an integrated and sustainable transport system will form; (2 at the county scale, the annual growth rates of GDP of counties surrounding the QTR were greater than those of non-surrounding counties for the period 2000–2010. At the 1 km scale, following the opening of the completed line, the GDP of surrounding areas had a greater growth rate than before; (3 analysis at the county and 1 km scales indicated that population was not aggregated into the surrounding areas of the QTR in the period 2000–2010; (4 in terms of industrial structure, the proportion of primary industry decreased continuously, while the proportion of secondary and tertiary industries increased overall in the period 1984–2012. The QTR had no obvious impact on changes in the urbanization level of its surrounding areas.

  6. Fluid-particle dynamics for passive tracers advected by a thermally fluctuating viscoelastic medium

    Science.gov (United States)

    Hohenegger, Christel; McKinley, Scott A.

    2017-07-01

    Many biological fluids, like mucus and cytoplasm, have prominent viscoelastic properties. As a consequence, immersed particles exhibit subdiffusive behavior, which is to say, the variance of the particle displacement grows sublinearly with time. In this work, we propose a viscoelastic generalization of the Landau-Lifschitz Navier-Stokes fluid model and investigate the properties of particles that are passively advected by such a medium. We exploit certain exact formulations that arise from the Gaussian nature of the fluid model and introduce analysis of memory in the fluid statistics, marking an important step toward capturing fluctuating hydrodynamics among subdiffusive particles. The proposed method is spectral, meshless and is based on the numerical evaluation of the covariance matrix associated with individual fluid modes. With this method, we probe a central hypothesis of passive microrheology, a field premised on the idea that the statistics of particle trajectories can reveal fundamental information about their surrounding fluid environment.

  7. Stochastic interpenetration of fluids

    Energy Technology Data Exchange (ETDEWEB)

    Steinkamp, M.J.; Clark, T.T.; Harlow, F.H.

    1995-11-01

    We describe a spectral approach to the investigation of fluid instability, generalized turbulence, and the interpenetration of fluids across an interface. The technique also applies to a single fluid with large variations in density. Departures of fluctuating velocity components from the local mean are far subsonic, but the mean Mach number can be large. Validity of the description is demonstrated by comparisons with experiments on turbulent mixing due to the late stages of Rayleigh-Taylor instability, when the dynamics become approximately self-similar in response to a constant body force. Generic forms for anisotropic spectral structure are described and used as a basis for deriving spectrally integrated moment equations that can be incorporated into computer codes for scientific and engineering analyses.

  8. Vorticity in holographic fluids

    CERN Document Server

    Caldarelli, Marco M; Petkou, Anastasios C; Petropoulos, P Marios; Pozzoli, Valentina; Siampos, Konstadinos

    2012-01-01

    In view of the recent interest in reproducing holographically various properties of conformal fluids, we review the issue of vorticity in the context of AdS/CFT. Three-dimensional fluids with vorticity require four-dimensional bulk geometries with either angular momentum or nut charge, whose boundary geometries fall into the Papapetrou--Randers class. The boundary fluids emerge in stationary non-dissipative kinematic configurations, which can be cyclonic or vortex flows, evolving in compact or non-compact supports. A rich network of Einstein's solutions arises, naturally connected with three-dimensional Bianchi spaces. We use Fefferman--Graham expansion to handle holographic data from the bulk and discuss the alternative for reversing the process and reconstruct the exact bulk geometries.

  9. Characterization of the Tumor Secretome from Tumor Interstitial Fluid (TIF).

    Science.gov (United States)

    Gromov, Pavel; Gromova, Irina

    2016-01-01

    Tumor interstitial fluid (TIF) surrounds and perfuses bodily tumorigenic tissues and cells, and can accumulate by-products of tumors and stromal cells in a relatively local space. Interstitial fluid offers several important advantages for biomarker and therapeutic target discovery, especially for cancer. Here, we describe the most currently accepted method for recovering TIF from tumor and nonmalignant tissues that was initially performed using breast cancer tissue. TIF recovery is achieved by passive extraction of fluid from small, surgically dissected tissue specimens in phosphate-buffered saline. We also present protocols for hematoxylin and eosin (H&E) staining of snap-frozen and formalin-fixed, paraffin-embedded (FFPE) tumor sections and for proteomic profiling of TIF and matched tumor samples by high-resolution two-dimensional gel electrophoresis (2D-PAGE) to enable comparative analysis of tumor secretome and paired tumor tissue.

  10. Absorption characteristics of bacteriorhodopsin molecules

    Indian Academy of Sciences (India)

    H K T Kumar; K Appaji Gowda

    2000-03-01

    The bacteriorhodopsin molecule absorbs light and undergoes a series of structural transformation following a well-defined photocycle. The complex photocycle is transformed to an equivalent level diagram by considering the lifetime of the intermediate states. Assuming that only and states are appreciably populated at any instant of time, the level diagram is further simplified to two-level system. Based on the rate equations for two-level system, an analytic expression for the absorption coefficient of bacteriorhodopsin molecule is derived. It is applied to study the behaviour of absorption coefficient of bacteriorhodopsin film in the visible wavelength region of 514 nm. The dependence of absorption coefficient of bacteriorhodopsin film on the thickness of the film, total number density of active molecules and initial number density of molecules in -state is presented in the graphical form.

  11. Cell adhesion molecules and sleep.

    Science.gov (United States)

    O'Callaghan, Emma Kate; Ballester Roig, Maria Neus; Mongrain, Valérie

    2017-03-01

    Cell adhesion molecules (CAMs) play essential roles in the central nervous system, where some families are involved in synaptic development and function. These synaptic adhesion molecules (SAMs) are involved in the regulation of synaptic plasticity, and the formation of neuronal networks. Recent findings from studies examining the consequences of sleep loss suggest that these molecules are candidates to act in sleep regulation. This review highlights the experimental data that lead to the identification of SAMs as potential sleep regulators, and discusses results supporting that specific SAMs are involved in different aspects of sleep regulation. Further, some potential mechanisms by which SAMs may act to regulate sleep are outlined, and the proposition that these molecules may serve as molecular machinery in the two sleep regulatory processes, the circadian and homeostatic components, is presented. Together, the data argue that SAMs regulate the neuronal plasticity that underlies sleep and wakefulness. Copyright © 2016 Elsevier Ireland Ltd and Japan Neuroscience Society. All rights reserved.

  12. Special Issue: Single Molecule Techniques

    Directory of Open Access Journals (Sweden)

    Hans H. Gorris

    2015-04-01

    Full Text Available Technological advances in the detection and manipulation of single molecules have enabled new insights into the function, structure and interactions of biomolecules. This Special Issue was launched to account for the rapid progress in the field of “Single Molecule Techniques”. Four original research articles and seven review articles provide an introduction, as well as an in-depth discussion, of technical developments that are indispensable for the characterization of individual biomolecules. Fluorescence microscopy takes center stage in this Special Issue because it is one of the most sensitive and flexible techniques, which has been adapted in many variations to the specific demands of single molecule analysis. Two additional articles are dedicated to single molecule detection based on atomic force microscopy.

  13. Quantum Transport Through Heterocyclic Molecules

    Science.gov (United States)

    Maiti, Santanu K.; Karmakar, S. N.

    We explore electron transport properties in molecular wires made of heterocyclic molecules (pyrrole, furan and thiophene) by using the Green's function technique. Parametric calculations are given based on the tight-binding model to describe the electron transport in these wires. It is observed that the transport properties are significantly influenced by (a) the heteroatoms in the heterocyclic molecules and (b) the molecule-to-electrodes coupling strength. Conductance (g) shows sharp resonance peaks associated with the molecular energy levels in the limit of weak molecular coupling, while they get broadened in the strong molecular coupling limit. These resonances get shifted with the change of the heteroatoms in these heterocyclic molecules. All the essential features of the electron transfer through these molecular wires become much more clearly visible from the study of our current-voltage (I-V) characteristics, and they provide several key information in the study of molecular transport.

  14. Experimental and numerical investigations of three-dimensional turbulent flow of water surrounding a CANDU simulation fuel bundle structure inside a channel

    Energy Technology Data Exchange (ETDEWEB)

    Abbasian, F.; Yu, S.D. [Department of Mechanical and Industrial Engineering, Ryerson University, 350 Victoria Street, Toronto, Ontario, M5B 2K3 (Canada); Cao, J. [Department of Mechanical and Industrial Engineering, Ryerson University, 350 Victoria Street, Toronto, Ontario, M5B 2K3 (Canada)], E-mail: jcao@ryerson.ca

    2009-11-15

    Computational fluid dynamics (CFD) is used to simulate highly turbulent coolant flows surrounding a simulation CANDU fuel bundle structure inside a flow channel. Three CFD methods are used: large eddy simulation (LES), detached eddy simulation (DES), and Reynolds stress model (RSM). The outcome of the simulations is compared with the experimental pressure data measured using an in-water microphone and a miniature pressure transducer placed at various locations in the vicinity of the bundle structure. Among all the three methods employed in developing computational models, LES provides the most accurate results for turbulent pressures.

  15. Why charged molecules move across a temperature gradient: the role of electric fields.

    Science.gov (United States)

    Reichl, Maren; Herzog, Mario; Götz, Alexandra; Braun, Dieter

    2014-05-16

    Methods to move solvated molecules are rare. Apart from electric fields, only thermal gradients are effective enough to move molecules inside a fluid. This effect is termed thermophoresis, and the underlying mechanisms are still poorly understood. Nevertheless, it is successfully used to quantify biomolecule binding in complex liquids. Here we show experiments that reveal that thermophoresis in water is dominated by two electric fields, both established by the salt ions of the solution. A local field around the molecule drives molecules along an energy gradient, whereas a global field moves the molecules by a combined thermoelectrophoresis mechanism known as the Seebeck effect. Both mechanisms combined predict the thermophoresis of DNA and RNA polymers for a wide range of experimental parameters. For example, we correctly predict a complex, nonlinear size transition, a salt-species-dependent offset, a maximum of thermophoresis over temperature, and the dependence of thermophoresis on the molecule concentration.

  16. Computational fluid dynamics

    CERN Document Server

    Magoules, Frederic

    2011-01-01

    Exploring new variations of classical methods as well as recent approaches appearing in the field, Computational Fluid Dynamics demonstrates the extensive use of numerical techniques and mathematical models in fluid mechanics. It presents various numerical methods, including finite volume, finite difference, finite element, spectral, smoothed particle hydrodynamics (SPH), mixed-element-volume, and free surface flow.Taking a unified point of view, the book first introduces the basis of finite volume, weighted residual, and spectral approaches. The contributors present the SPH method, a novel ap

  17. Fluids in cosmology

    CERN Document Server

    Cervantes-Cota, Jorge L

    2014-01-01

    We review the role of fluids in cosmology by first introducing them in General Relativity and then applied to a FRW Universe's model. We describe how relativistic and non-relativistic components evolve in the background dynamics. We also introduce scalar fields to show that they are able to yield an inflationary dynamics at very early times (inflation) and late times (quintessence). Then, we proceed to study the thermodynamical properties of the fluids and, lastly, its perturbed kinematics. We make emphasis in the constrictions of parameters by recent cosmological probes.

  18. Computational fluid dynamics

    CERN Document Server

    Blazek, Jiri

    2015-01-01

    Computational Fluid Dynamics: Principles and Applications, Third Edition presents students, engineers, and scientists with all they need to gain a solid understanding of the numerical methods and principles underlying modern computation techniques in fluid dynamics. By providing complete coverage of the essential knowledge required in order to write codes or understand commercial codes, the book gives the reader an overview of fundamentals and solution strategies in the early chapters before moving on to cover the details of different solution techniques. This updated edition includes new

  19. Mechanics of fluid flow

    CERN Document Server

    Basniev, Kaplan S; Chilingar, George V 0

    2012-01-01

    The mechanics of fluid flow is a fundamental engineering discipline explaining both natural phenomena and human-induced processes, and a thorough understanding of it is central to the operations of the oil and gas industry.  This book, written by some of the world's best-known and respected petroleum engineers, covers the concepts, theories, and applications of the mechanics of fluid flow for the veteran engineer working in the field and the student, alike.  It is a must-have for any engineer working in the oil and gas industry.

  20. Ongoing controversies surrounding cardiac remodeling: is it black and white-or rather fifty shades of gray?

    Science.gov (United States)

    Spaich, Sebastian; Katus, Hugo A; Backs, Johannes

    2015-01-01

    Cardiac remodeling describes the heart's multimodal response to a myriad of external or intrinsic stimuli and stressors most of which are probably only incompletely elucidated to date. Over many years the signaling molecules involved in these remodeling processes have been dichotomized according to a classic antagonistic view of black and white, i.e., attributed either a solely maladaptive or entirely beneficial character. By dissecting controversies, recent developments and shifts in perspective surrounding the three major cardiac signaling molecules calcineurin (Cn), protein kinase A (PKA) and calcium/calmodulin-dependent kinase II (CaMKII), this review challenges this dualistic view and advocates the nature and dignity of each of these key mediators of cardiac remodeling as a multilayered, highly context-sensitive and sophisticated continuum that can be markedly swayed and influenced by a multitude of environmental factors and crosstalk mechanisms. Furthermore this review delineates the importance and essential contributions of degradation and proteolysis to cardiac plasticity and homeostasis and finally aims to integrate the various aspects of protein synthesis and turnover into a comprehensive picture.

  1. Ongoing controversies surrounding cardiac remodeling: is it black and white – or rather fifty shades of grey?

    Directory of Open Access Journals (Sweden)

    Sebastian eSpaich

    2015-07-01

    Full Text Available Cardiac remodeling describes the heart’s multimodal response to a myriad of external or intrinsic stimuli and stressors most of which are probably only incompletely elucidated to date. Over many years the signaling molecules involved in these remodeling processes have been dichotomized according to a classic antagonistic view of black and white, i.e. attributed either a solely maladaptive or entirely beneficial character. By dissecting controversies, recent developments and shifts in perspective surrounding the 3 major cardiac signaling molecules calcineurin (Cn, protein kinase A (PKA and calcium/calmodulin-dependent kinase II (CaMKII, this review challenges this dualistic view and advocates the nature and dignity of each of these key mediators of cardiac remodeling as a multilayered, highly context-sensitive and sophisticated continuum that can be markedly swayed and influenced by a multitude of environmental factors and crosstalk mechanisms.Furthermore this review delineates the importance and essential contributions of degradation and proteolysis to cardiac plasticity and homeostasis and finally aims to integrate the various aspects of protein synthesis and turnover into a comprehensive picture.

  2. Guidance molecules in lung cancer

    OpenAIRE

    Nasarre, Patrick; Potiron, Vincent; Drabkin, Harry; Roche, Joëlle

    2010-01-01

    Guidance molecules were first described in the nervous system to control axon outgrowth direction. They are also widely expressed outside the nervous system where they control cell migration, tissue development and establishment of the vascular network. In addition, they are involved in cancer development, tumor angiogenesis and metastasis. This review is primarily focused on their functions in lung cancer and their involvement in lung development is also presented. Five guidance molecule fam...

  3. Plasmonic atoms and plasmonic molecules

    CERN Document Server

    Klimov, V V

    2007-01-01

    The proposed paradigm of plasmonic atoms and plasmonic molecules allows one to describe and predict the strongly localized plasmonic oscillations in the clusters of nanoparticles and some other nanostructures in uniform way. Strongly localized plasmonic molecules near the contacting surfaces might become the fundamental elements (by analogy with Lego bricks) for a construction of fully integrated opto-electronic nanodevices of any complexity and scale of integration.

  4. Plasmonic atoms and plasmonic molecules

    Science.gov (United States)

    Klimov, V. V.; Guzatov, D. V.

    2007-11-01

    The proposed paradigm of plasmonic atoms and plasmonic molecules allows one to describe and predict the strongly localized plasmonic oscillations in the clusters of nanoparticles and some other nanostructures in uniform way. Strongly localized plasmonic molecules near the contacting surfaces might become the fundamental elements (by analogy with Lego bricks) for the construction of fully integrated opto-electronic nanodevices of any complexity and scale of integration.

  5. Optofluidic single molecule flow proteometry

    Science.gov (United States)

    Jing, Nan; Chou, Chao-Kai; Hung, Mien-Chie; Kameoka, Jun

    2009-02-01

    A microfluidic single molecule fluorescence-based detection scheme is developed to identify target protein direct from cell lysate by using polyclonal antibody. Relative concentration of target protein in solution is determined by twodimensional (2D) photon burst analysis. Compared to conventional ensemble measurement assays, this microfluidic single molecule approach combines the advantages of higher sensitivity, fast processing time, small sample consumption and high resolution quantitative analysis.

  6. Compressibility of the fluid

    Directory of Open Access Journals (Sweden)

    Jablonská Jana

    2014-03-01

    Full Text Available The presence of air in the liquid causes the dynamic system behaviour. When solve to issue of the dynamics we often meet problems of cavitation. Cavitation is an undesirable phenomenon, since it causes a disruption of the surrounding material and material destruction. Cavitation is accompanied by loud sound effects and reduces the efficiency of such pumps, etc. Therefore, it is desirable to model systems in which the cavitation might occur. A typical example is a solution of water hammer.

  7. Hydraulic fracturing fluid migration in the subsurface: A review and expanded modeling results

    Science.gov (United States)

    Birdsell, Daniel T.; Rajaram, Harihar; Dempsey, David; Viswanathan, Hari S.

    2015-09-01

    Understanding the transport of hydraulic fracturing (HF) fluid that is injected into the deep subsurface for shale gas extraction is important to ensure that shallow drinking water aquifers are not contaminated. Topographically driven flow, overpressured shale reservoirs, permeable pathways such as faults or leaky wellbores, the increased formation pressure due to HF fluid injection, and the density contrast of the HF fluid to the surrounding brine can encourage upward HF fluid migration. In contrast, the very low shale permeability and capillary imbibition of water into partially saturated shale may sequester much of the HF fluid, and well production will remove HF fluid from the subsurface. We review the literature on important aspects of HF fluid migration. Single-phase flow and transport simulations are performed to quantify how much HF fluid is removed via the wellbore with flowback and produced water, how much reaches overlying aquifers, and how much is permanently sequestered by capillary imbibition, which is treated as a sink term based on a semianalytical, one-dimensional solution for two-phase flow. These simulations include all of the important aspects of HF fluid migration identified in the literature review and are performed in five stages to faithfully represent the typical operation of a hydraulically fractured well. No fracturing fluid reaches the aquifer without a permeable pathway. In the presence of a permeable pathway, 10 times more fracturing fluid reaches the aquifer if well production and capillary imbibition are not included in the model.

  8. An oxygen-rich dust disk surrounding an evolved star in the Red Rectangle

    NARCIS (Netherlands)

    Waters, LBFM; Waelkens, C; van Winckel, H; Molster, FJ; Tielens, AGGM; van Loon, JT; Morris, PW; Cami, J; Bouwman, J; de Koter, A; de Jong, T; de Graauw, T

    1998-01-01

    The Red Rectangle(1) is the prototype of a class of carbon-rich reflection nebulae surrounding low-mass stars in the final stages of evolution. The central star of this nebula has ejected most of its layers (during the red-giant phase), which now form the surrounding cloud, and is rapidly evolving t

  9. The Space of an Object: Object Attention Alters the Spatial Gradient in the Surround

    Science.gov (United States)

    Kravitz, Dwight Jacob; Behrmann, Marlene

    2008-01-01

    Although object-based attention enhances perceptual processing of information appearing within the boundaries of a selected object, little is known about the consequences for information in the object's surround. The authors show that distance from an attended object's center of mass determines reaction time (RT) to targets in the surround. Of 2…

  10. Different surrounding landscapes may result in different fish assemblages in East African seagrass beds

    NARCIS (Netherlands)

    Dorenbosch, M.; Grol, M.G.G.; Nagelkerken, I.; Velde, G. van der

    2006-01-01

    Few studies have considered how seagrass fish assemblages are influenced by surrounding habitats. This information is needed for a better understanding of the connectivity between tropical coastal ecosystems. To study the effects of surrounding habitats on the composition, diversity and densities of

  11. Surround modulation characteristics of local field potential and spiking activity in primary visual cortex of cat.

    Directory of Open Access Journals (Sweden)

    Li Zhang

    Full Text Available In primary visual cortex, spiking activity that evoked by stimulus confined in receptive field can be modulated by surround stimulus. This center-surround interaction is hypothesized to be the basis of visual feature integration and segregation. Spiking output has been extensively reported to be surround suppressive. However, less is known about the modulation properties of the local field potential (LFP, which generally reflects synaptic inputs. We simultaneously recorded spiking activity and LFP in the area 17 of anesthetized cats to examine and compare their modulation characteristics. When the stimulus went beyond the classical receptive field, LFP exhibited decreased power along the gamma band (30-100 Hz in most of our recording sites. Further investigation revealed that suppression of the LFP gamma mean power (gLFP depended on the angle between the center and surround orientations. The strongest suppression was induced when center and surround orientations were parallel. Moreover, the surround influence of the gLFP exhibited an asymmetric spatial organization. These results demonstrate that the gLFP has similar but not identical surround modulation properties, as compared to the spiking activity. The spatiotemporal integration of LFP implies that the oscillation and synchronization of local synaptic inputs may have important functions in surround modulation.

  12. Effects of surrounding elements on city image in the sample of Erzurum city

    Directory of Open Access Journals (Sweden)

    S. Ozer

    2010-05-01

    Full Text Available Structural elements which are the parts of city identities are shaped as the result of social and cultural characteristics and natural factors. In order to increase visual quality of cities and make cities more liveable landscape architects use not only living materials such as plants but also nonliving materials. This study was carried out to investigate the effects of surrounding elements which are vertical elements in landscape designs, on functional and city aesthetics. With this aim, materials used in surrounding elements around houses in Erzurum, houses surrounded by these elements and their harmony with their surroundings, aesthetics and functional effects were investigated and their contributions to city image were determined. While surrounding elements are mainly adequate in functions, they are lower quality in aesthetics. Some suggestions were offered for the city images that local councils should be careful on and due to Universiade in 2011.

  13. Catastrophe mechanism and disaster countermeasure for soft rock roadway surrounding rock in Meihe mine

    Institute of Scientific and Technical Information of China (English)

    Yu Yang⇑; Zhu Caikun; Chong Deyu; Liu Yang; Li Sichao

    2015-01-01

    The soft rock’s heterogeneity and nonlinear mechanical behavior cause extremely difficult maintenance on the soft rock roadway. Aiming at the asymmetric deformation and destruction phenomenon appearing after excavating and supporting the 7101 air return way in Meihe mine, this paper comprehensively adopted a variety of methods to analyze the roadway surrounding rock deformation rule, obtaining the roadway surrounding rock stress and plastic zone distribution rule under no supporting condition and the roadway surrounding rock deformation features under original symmetric supporting condition. Furthermore, this paper revealed the catastrophe mechanism, and proposed the concept of‘weak struc-ture’ and the disaster countermeasure of‘overall stabilizing the roadway and strengthening the support of weak structure’ . The industrial test shows that the disaster control technology can realize the coordination deformation of the supporting structure and roadway surrounding rock, thus significantly controlling the deformation of roadway surrounding rock.

  14. Effect of longwall length on mechanical characteristics of surrounding rock stress shell in mining face

    Energy Technology Data Exchange (ETDEWEB)

    Guang-Xiang Xie; Lei Wang [Anhui University of Science and Technology, Huainan (China)

    2008-12-15

    The mechanical characteristics of surrounding rock stress shell in longwall mining face were studied, based on the results of in-situ measurement combined with numerical simulation, and the effect of longwall length on mechanical characteristics of surrounding rock stress shell was discovered. The results show that the mechanical characteristics of surrounding rock stress shell are influenced by the length of the face. With an increase of mining face length, the level of concentration of shell stress located in the front face and surrounding rock of roadway is amplified and the three- dimensional stress is focused in the working face. The damage lies in the head entry corner of face and the vertical displacement is reduced but horizontal displacement is enlarged. The dynamic balance of surrounding rock stress shell is improved with rational adjustment of face length. It is effective in protecting the working face and controlling strata behavior. 5 refs., 7 figs.

  15. Stability classification model of mine-lane surrounding rock based on distance discriminant analysis method

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei; LI Xi-bing; GONG Feng-qiang

    2008-01-01

    Based on the principle of Mahalanobis distance discriminant analysis (DDA) theory, a stability classification model for mine-lane surrounding rock was established, including six indexes of discriminant factors that reflect the engineering quality of surrounding rock: lane depth below surface, span of lane, ratio of directly top layer thickness to coal thickness, uniaxial comprehensive strength of surrounding rock, development degree coefficient of surrounding rock joint and range of broken surrounding rock zone. A DDA model was obtained through training 15 practical measuring samples. The re-substitution method was introduced to verify the stability of DDA model and the ratio of mis-discrimination is zero. The DDA model was used to discriminate3 new samples and the results are identical with actual rock kind. Compared with the artificial neural network method and support vector mechanic method, the results show that this model has high prediction accuracy and can be used in practical engineering.

  16. Varieties of Quest and the Religious Openness Hypothesis within Religious Fundamentalist and Biblical Foundationalist Ideological Surrounds

    Directory of Open Access Journals (Sweden)

    P. J. Watson

    2013-12-01

    Full Text Available According to the Religious Openness Hypothesis, the religious and psychological openness of American Christians is obscured by a defensive ghettoization of thought associated with a Religious Fundamentalist Ideological Surround and can be discovered instead within a Biblical Foundationalist Ideological Surround. A test of this claim examined Religious Fundamentalism, Biblical Foundationalism, Quest, and Multidimensional Quest Scales in 432 undergraduates. Christian Religious Reflection, Religious Schema, and Religious Orientation measures clarified these two ideological surrounds. Partial correlations controlling for Biblical Foundationalism described a Religious Fundamentalist Ideological Surround that more strongly rejected Quest and that more generally displayed a failure to integrate faith with intellect. Partial correlations controlling for Religious Fundamentalism revealed a Biblical Foundationalist Ideological Surround that was more open to Quest and that offered numerous demonstrations of an ability to unite faith with intellect. These data supplemented previous investigations in demonstrating that Christianity and other traditional religions have ideological resources for promoting a faithful intellect.

  17. Fluid Jet Polishing

    NARCIS (Netherlands)

    Booij, S.M.

    2003-01-01

    The goal of this thesis research was to investigate the possibilities and limitations of the Fluid Jet Polishing (FJP) technique. FJP is a new optical fabrication technique that is capable of making shape corrections and reducing the surface roughness of glass and other materials. The principle of o

  18. Proteomics of body fluids

    NARCIS (Netherlands)

    L.J.M. Dekker (Lennard)

    2007-01-01

    textabstractIn this thesis we present newly developed methods for biomarker discovery. We applied these methods to discover biomarkers of leptomeningeal metastasis (LM) in the cerebrospinal fluid (CSF) from breast cancer patients and in serum from patients with prostate cancer. Early diagnos

  19. Fluid Jet Polishing

    NARCIS (Netherlands)

    Booij, S.M.

    2003-01-01

    The goal of this thesis research was to investigate the possibilities and limitations of the Fluid Jet Polishing (FJP) technique. FJP is a new optical fabrication technique that is capable of making shape corrections and reducing the surface roughness of glass and other materials. The principle of

  20. Orbital Fluid Resupply Assessment

    Science.gov (United States)

    Eberhardt, Ralph N.

    1989-01-01

    Orbital fluid resupply can significantly increase the cost-effectiveness and operational flexibility of spacecraft, satellites, and orbiting platforms and observatories. Reusable tankers are currently being designed for transporting fluids to space. A number of options exist for transporting the fluids and propellant to the space-based user systems. The fluids can be transported to space either in the Shuttle cargo bay or using expendable launch vehicles (ELVs). Resupply can thus be accomplished either from the Shuttle bay, or the tanker can be removed from the Shuttle bay or launched on an ELV and attached to a carrier such as the Orbital Maneuvering Vehicle (OMV) or Orbital Transfer Vehicle (OTV) for transport to the user to be serviced. A third option involves locating the tanker at the space station or an unmanned platform as a quasi-permanent servicing facility or depot which returns to the ground for recycling once its tanks are depleted. Current modular tanker designs for monopropellants, bipropellants, and water for space station propulsion are discussed. Superfluid helium tankers are addressed, including trade-offs in tanker sizes, shapes to fit the range of ELVs currently available, and boil-off losses associated with longer-term (greater than 6-month) space-basing. It is concluded that the mixed fleet approach to on-orbit consumables resupply offers significant advantages to the overall logistics requirements.

  1. Fluid resuscitation in trauma

    Directory of Open Access Journals (Sweden)

    Rudra A

    2006-01-01

    Full Text Available Appropriate fluid replacement is an essential component of trauma fluid resuscitation. Once hemorrhage is controlled, restoration of normovolemia is a priority. In the presence of uncontrolled haemorrhage, aggressive fluid management may be harmful. The crystalloid-colloid debate continues but existing clinical practice is more likely to reflect local biases rather than evidence based medicine. Colloids vary substantially in their pharmacology and pharmacokinetics,and the experimental finding based on one colloid cannot be extrapolated reliably to another. In the initial stages of trauma resuscitation the precise fluid used is probably not important as long as an appropriate volume is given. Later, when the microcirculation is ′leaky′, there may be some advantages to high or medium weight colloids such as hydroxyethyl starch. Hypertonic saline solutions may have some benefit in patients with head injuries. A number of hemoglobin solutions are under development, but one of the most promising of these has been withdrawn recently. It is highly likely that at least one of these solutions will eventually become routine therapy for trauma patient resuscitation. In the meantime, contrary to traditional teaching, recent data suggest that restrictive strategy of red cell transfusion may improve outcome in some critically ill patients.

  2. Amniotic Fluid Embolism

    Science.gov (United States)

    ... embolisms are rare, which makes it difficult to identify risk factors. It's estimated that there are between 1 ... Kramer MS, et al. Amniotic fluid embolism: Incidence, risk factors, and impact on perinatal outcome. BJOG: An International Journal of Obstetrics and Gynaecology. 2012;119:874. Baskett ...

  3. Relativistic viscoelastic fluid mechanics.

    Science.gov (United States)

    Fukuma, Masafumi; Sakatani, Yuho

    2011-08-01

    A detailed study is carried out for the relativistic theory of viscoelasticity which was recently constructed on the basis of Onsager's linear nonequilibrium thermodynamics. After rederiving the theory using a local argument with the entropy current, we show that this theory universally reduces to the standard relativistic Navier-Stokes fluid mechanics in the long time limit. Since effects of elasticity are taken into account, the dynamics at short time scales is modified from that given by the Navier-Stokes equations, so that acausal problems intrinsic to relativistic Navier-Stokes fluids are significantly remedied. We in particular show that the wave equations for the propagation of disturbance around a hydrostatic equilibrium in Minkowski space-time become symmetric hyperbolic for some range of parameters, so that the model is free of acausality problems. This observation suggests that the relativistic viscoelastic model with such parameters can be regarded as a causal completion of relativistic Navier-Stokes fluid mechanics. By adjusting parameters to various values, this theory can treat a wide variety of materials including elastic materials, Maxwell materials, Kelvin-Voigt materials, and (a nonlinearly generalized version of) simplified Israel-Stewart fluids, and thus we expect the theory to be the most universal description of single-component relativistic continuum materials. We also show that the presence of strains and the corresponding change in temperature are naturally unified through the Tolman law in a generally covariant description of continuum mechanics.

  4. Cholinergic enhancement reduces orientation-specific surround suppression but not visual crowding.

    Science.gov (United States)

    Kosovicheva, Anna A; Sheremata, Summer L; Rokem, Ariel; Landau, Ayelet N; Silver, Michael A

    2012-01-01

    Acetylcholine (ACh) reduces the spatial spread of excitatory fMRI responses in early visual cortex and receptive field size of V1 neurons. We investigated the perceptual consequences of these physiological effects of ACh with surround suppression and crowding, two phenomena that involve spatial interactions between visual field locations. Surround suppression refers to the reduction in perceived stimulus contrast by a high-contrast surround stimulus. For grating stimuli, surround suppression is selective for the relative orientations of the center and surround, suggesting that it results from inhibitory interactions in early visual cortex. Crowding refers to impaired identification of a peripheral stimulus in the presence of flankers and is thought to result from excessive integration of visual features. We increased synaptic ACh levels by administering the cholinesterase inhibitor donepezil to healthy human subjects in a placebo-controlled, double-blind design. In Experiment 1, we measured surround suppression of a central grating using a contrast discrimination task with three conditions: (1) surround grating with the same orientation as the center (parallel), (2) surround orthogonal to the center, or (3) no surround. Contrast discrimination thresholds were higher in the parallel than in the orthogonal condition, demonstrating orientation-specific surround suppression (OSSS). Cholinergic enhancement decreased thresholds only in the parallel condition, thereby reducing OSSS. In Experiment 2, subjects performed a crowding task in which they reported the identity of a peripheral letter flanked by letters on either side. We measured the critical spacing between the targets and flanking letters that allowed reliable identification. Cholinergic enhancement with donepezil had no effect on critical spacing. Our findings suggest that ACh reduces spatial interactions in tasks involving segmentation of visual field locations but that these effects may be limited to early

  5. Cholinergic enhancement reduces orientation-specific surround suppression but not visual crowding

    Directory of Open Access Journals (Sweden)

    Anna A. Kosovicheva

    2012-09-01

    Full Text Available Acetylcholine (ACh reduces the spatial spread of excitatory fMRI responses in early visual cortex and the receptive field sizes of V1 neurons. We investigated the perceptual consequences of these physiological effects of ACh with surround suppression and crowding, two tasks that involve spatial interactions between visual field locations. Surround suppression refers to the reduction in perceived stimulus contrast by a high-contrast surround stimulus. For grating stimuli, surround suppression is selective for the relative orientations of the center and surround, suggesting that it results from inhibitory interactions in early visual cortex. Crowding refers to impaired identification of a peripheral stimulus in the presence of flankers and is thought to result from excessive integration of visual features. We increased synaptic ACh levels by administering the cholinesterase inhibitor donepezil to healthy human subjects in a placebo-controlled, double-blind design. In Exp. 1, we measured surround suppression of a central grating using a contrast discrimination task with three conditions: 1 surround grating with the same orientation as the center (parallel, 2 surround orthogonal to the center, or 3 no surround. Contrast discrimination thresholds were higher in the parallel than in the orthogonal condition, demonstrating orientation-specific surround suppression (OSSS. Cholinergic enhancement reduced thresholds only in the parallel condition, thereby reducing OSSS. In Exp. 2, subjects performed a crowding task in which they reported the identity of a peripheral letter flanked by letters on either side. We measured the critical spacing between the target and flanking letters that allowed reliable identification. Cholinergic enhancement had no effect on critical spacing. Our findings suggest that ACh reduces spatial interactions in tasks involving segmentation of visual field locations but that these effects may be limited to early visual cortical

  6. Neural mechanisms of surround attenuation and distractor competition in visual search.

    Science.gov (United States)

    Boehler, Carsten N; Tsotsos, John K; Schoenfeld, Mircea A; Heinze, Hans-Jochen; Hopf, Jens-Max

    2011-04-06

    Visual attention biases relevant processing in the visual system by amplifying relevant or attenuating irrelevant sensory input. A potential signature of the latter operation, referred to as surround attenuation, has recently been identified in the electromagnetic brain response of human observers performing visual search. It was found that a zone of attenuated cortical excitability surrounds the target when the search required increased spatial resolution for item discrimination. Here we address the obvious hypothesis that surround attenuation serves distractor suppression in the vicinity of the target where interference from irrelevant search items is maximal. To test this hypothesis, surround attenuation was assessed under conditions when the target was presented in isolation versus when it was surrounded by distractors. Surprisingly, substantial and indistinguishable surround attenuation was seen under both conditions, indicating that it reflects an attentional operation independent of the presence of distractors. Adding distractors in the target's surround, however, increased the amplitude of the N2pc--an evoked response known to index distractor competition in visual search. Moreover, adding distractors led to a topographical change of source activity underlying the N2pc toward earlier extrastriate areas. In contrast, the topography of reduced source activity due to surround attenuation remained unaltered with and without distractors in the target's surround. We conclude that surround attenuation is not a direct consequence of the attenuation of distractors in visual search and that it dissociates from attentional operations reflected by the N2pc. A theoretical framework is proposed that links both operations in a common model of top-down attentional selection in visual cortex.

  7. Validation of bovine oestrous-specific synthetic molecules with trained scent dogs; similarities between natural and synthetic oestrous smell.

    Science.gov (United States)

    Fischer-Tenhagen, C; Johnen, D; Le Danvic, C; Gatien, J; Salvetti, P; Tenhagen, B A; Heuwieser, W

    2015-02-01

    Oestrous detection is crucial for successful dairy cow reproduction. Bulls identify cows in oestrus by oestrous-specific odours especially in urine and vaginal fluid. These have been used to train dogs to detect cows in heat. To improve and simplify the dog training, a spray containing synthetic oestrous molecules was developed. The objective of this study was to test the spray on similarities to the natural substance thus to assess its suitability as a training substance for heat detection dogs. Ten privately owned dogs of various breeds were trained. Dogs should be trained either to differentiate natural vaginal fluid from cows in oestrus and dioestrus (n = 5), or spray with or without synthetic oestrous molecules (n = 5). Dogs trained on natural fluid and on spray could detect the oestrous odour they had been trained on with an overall accuracy of 69.0% and 82.4%, respectively (p = 0.019). To validate the synthetic molecules, dogs trained with synthetic molecules had to detect oestrous odour in natural fluid without further training (accuracy 37.6%). Dogs trained on natural fluid detected the synthetic molecules with an accuracy of 50.0% (50% vs 37.4%, p cows in oestrus after they have been trained with synthetic oestrous molecules, but accuracy needs to be improved.

  8. Statistical mechanical theory of fluid mixtures

    Science.gov (United States)

    Zhao, Yueqiang; Wu, Zhengming; Liu, Weiwei

    2014-01-01

    A general statistical mechanical theory of fluid mixtures (liquid mixtures and gas mixtures) is developed based on the statistical mechanical expression of chemical potential of components in the grand canonical ensemble, which gives some new relationships between thermodynamic quantities (equilibrium ratio Ki, separation factor α and activity coefficient γi) and ensemble average potential energy u for one molecule. The statistical mechanical expressions of separation factor α and activity coefficient γi derived in this work make the fluid phase equilibrium calculations can be performed by molecular simulation simply and efficiently, or by the statistical thermodynamic approach (based on the saturated-vapor pressure of pure substance) that does not need microscopic intermolecular pair potential functions. The physical meaning of activity coefficient γi in the liquid phase is discussed in detail from a viewpoint of molecular thermodynamics. The calculated Vapor-Liquid Equilibrium (VLE) properties of argon-methane, methanol-water and n-hexane-benzene systems by this model fit well with experimental data in references, which indicates that this model is accurate and reliable in the prediction of VLE properties for small, large and strongly associating molecules; furthermore the statistical mechanical expressions of separation factor α and activity coefficient γi have good compatibility with classical thermodynamic equations and quantum mechanical COSMO-SAC approach.

  9. Signaling Molecules and Pulp Regeneration.

    Science.gov (United States)

    Schmalz, Gottfried; Widbiller, Matthias; Galler, Kerstin M

    2017-09-01

    Signaling molecules play an essential role in tissue engineering because they regulate regenerative processes. Evidence exists from animal studies that single molecules such as members of the transforming growth factor beta superfamily and factors that induce the growth of blood vessels (vascular endothelial growth factor), nerves (brain-derived neurotrophic factor), or fibroblasts (fibroblast growth factor) may induce reparative dentin formation. Mainly the formation of atubular dentin (osteodentin) has been described after the application of single molecules or combinations of recombinant growth factors on healthy exposed pulps or in pulp regeneration. Generally, such preparations have not received regulatory approval on the market so far. Only the use of granulocyte colony-stimulating factors together with cell transplantation is presently tested clinically. Besides approaches with only 1 or few combined molecules, the exploitation of tissue-derived growth factors depicts a third promising way in dental pulp tissue engineering. Preparations such as platelet-rich plasma or platelet-rich fibrin provide a multitude of endogenous signaling molecules, and special regulatory approval for the market does not seem necessary. Furthermore, dentin is a perfect reservoir of signaling molecules that can be mobilized by treatment with demineralizing agents such as EDTA. This conditions the dentin surface and allows for contact differentiation of pulp stem cells into odontoblastlike cells, protects dentin from resorption, and enhances cell growth as well as attachment to dentin. By ultrasonic activation, signaling molecules can be further released from EDTA pretreated dentin into saline, thus avoiding cytotoxic EDTA in the final preparation. The use of dentin-derived growth factors offers a number of advantages because they are locally available and presumably are most fit to induce signaling processes in dental pulp. However, better characterization and standardization of the

  10. Raman Optical Activity Spectra for Large Molecules through Molecules-in-Molecules Fragment-Based Approach.

    Science.gov (United States)

    Jovan Jose, K V; Raghavachari, Krishnan

    2016-02-09

    We present an efficient method for the calculation of the Raman optical activity (ROA) spectra for large molecules through the molecules-in-molecules (MIM) fragment-based method. The relevant higher energy derivatives from smaller fragments are used to build the property tensors of the parent molecule to enable the extension of the MIM method for evaluating ROA spectra (MIM-ROA). Two factors were found to be particularly important in yielding accurate results. First, the link-atom tensor components are projected back onto the corresponding host and supporting atoms through the Jacobian projection method, yielding a mathematically rigorous method. Second, the long-range interactions between fragments are taken into account by using a less computationally expensive lower level of theory. The performance of the MIM-ROA model is calibrated on the enantiomeric pairs of 10 carbohydrate benchmark molecules, with strong intramolecular interactions. The vibrational frequencies and ROA intensities are accurately reproduced relative to the full, unfragmented, results for these systems. In addition, the MIM-ROA method is employed to predict the ROA spectra of d-maltose, α-D-cyclodextrin, and cryptophane-A, yielding spectra in excellent agreement with experiment. The accuracy and performance of the benchmark systems validate the MIM-ROA model for exploring ROA spectra of large molecules.

  11. The Molecule Cloud - compact visualization of large collections of molecules.

    Science.gov (United States)

    Ertl, Peter; Rohde, Bernhard

    2012-07-06

    Analysis and visualization of large collections of molecules is one of the most frequent challenges cheminformatics experts in pharmaceutical industry are facing. Various sophisticated methods are available to perform this task, including clustering, dimensionality reduction or scaffold frequency analysis. In any case, however, viewing and analyzing large tables with molecular structures is necessary. We present a new visualization technique, providing basic information about the composition of molecular data sets at a single glance. A method is presented here allowing visual representation of the most common structural features of chemical databases in a form of a cloud diagram. The frequency of molecules containing particular substructure is indicated by the size of respective structural image. The method is useful to quickly perceive the most prominent structural features present in the data set. This approach was inspired by popular word cloud diagrams that are used to visualize textual information in a compact form. Therefore we call this approach "Molecule Cloud". The method also supports visualization of additional information, for example biological activity of molecules containing this scaffold or the protein target class typical for particular scaffolds, by color coding. Detailed description of the algorithm is provided, allowing easy implementation of the method by any cheminformatics toolkit. The layout algorithm is available as open source Java code. Visualization of large molecular data sets using the Molecule Cloud approach allows scientists to get information about the composition of molecular databases and their most frequent structural features easily. The method may be used in the areas where analysis of large molecular collections is needed, for example processing of high throughput screening results, virtual screening or compound purchasing. Several example visualizations of large data sets, including PubChem, ChEMBL and ZINC databases using

  12. The Molecule Cloud - compact visualization of large collections of molecules

    Directory of Open Access Journals (Sweden)

    Ertl Peter

    2012-07-01

    Full Text Available Abstract Background Analysis and visualization of large collections of molecules is one of the most frequent challenges cheminformatics experts in pharmaceutical industry are facing. Various sophisticated methods are available to perform this task, including clustering, dimensionality reduction or scaffold frequency analysis. In any case, however, viewing and analyzing large tables with molecular structures is necessary. We present a new visualization technique, providing basic information about the composition of molecular data sets at a single glance. Summary A method is presented here allowing visual representation of the most common structural features of chemical databases in a form of a cloud diagram. The frequency of molecules containing particular substructure is indicated by the size of respective structural image. The method is useful to quickly perceive the most prominent structural features present in the data set. This approach was inspired by popular word cloud diagrams that are used to visualize textual information in a compact form. Therefore we call this approach “Molecule Cloud”. The method also supports visualization of additional information, for example biological activity of molecules containing this scaffold or the protein target class typical for particular scaffolds, by color coding. Detailed description of the algorithm is provided, allowing easy implementation of the method by any cheminformatics toolkit. The layout algorithm is available as open source Java code. Conclusions Visualization of large molecular data sets using the Molecule Cloud approach allows scientists to get information about the composition of molecular databases and their most frequent structural features easily. The method may be used in the areas where analysis of large molecular collections is needed, for example processing of high throughput screening results, virtual screening or compound purchasing. Several example visualizations of large

  13. Partial characterization of the factor in theca-cell conditioned medium that inhibits the progression of FSH-induced meiosis of bovine oocytes surrounded by cumulus cells connected to the membrana granulosa.

    Science.gov (United States)

    van Tol, H T; Bevers, M M

    2001-11-01

    A factor, secreted by theca cells, inhibits FSH induced resumption of meiosis in bovine oocytes that are surrounded by cumulus cells which are attached to a piece of the membrana granulosa (COCGs). In order to characterize this factor, theca cell conditioned medium (CMt) was heat-treated, filtered through a 5 kD spin off filter, charcoal treated, chloroform extracted and protease treated. To investigate whether the meiosis inhibiting factor produced by theca cells was also present in follicular fluid (FF), the same treatments were done with 50% bovine follicular fluid (bFF). COCGs, originating from 2 to 8 mm follicles of bovine ovaries collected at a slaughterhouse, were cultured in groups of 15 per 600 microl medium supplemented with 0.05 IU ml FSH for 22 hr at 39 degrees C in a humidified atmosphere of 5% CO(2). After culture the oocytes were denuded, stained with orcein, and the nuclear status assessed. Heat treatment did not affect the meiosis arresting capacity of CMt since a similar proportion of the oocytes remained at the GV stage after 22 hr of culture in heat treated CMt as compared to the proportion of oocytes in the GV stage after culture in untreated CMt. Filtering through a 5 kD spin-off filter revealed that the meiosis inhibiting action was maintained in the <5 kD fraction, although there was a significant (P < 0.05) loss of inhibiting activity compared to nonfiltered CMt. No significant decrease was observed in the meiosis arresting capacity of the <5 kD fraction after charcoal or protease treatment. Extraction of the <5 kD fraction with chloroform also did not affect the theca cell produced factor. The effect of the theca cell factor on the progression of meiosis of the oocytes that resumed meiosis, as demonstrated by a very low percentage of the oocytes that matured up to the M2 stage, was not affected following any of the treatments. With regard to bFF, the results show a lower percentage of the oocytes in the GV stage after culture in 50% bFF as

  14. Biosensor Arrays for Estimating Molecular Concentration in Fluid Flows

    CERN Document Server

    Abolfath-Beygi, Maryam

    2011-01-01

    This paper constructs dynamical models and estimation algorithms for the concentration of target molecules in a fluid flow using an array of novel biosensors. Each biosensor is constructed out of protein molecules embedded in a synthetic cell membrane. The concentration evolves according to an advection-diffusion partial differential equation which is coupled with chemical reaction equations on the biosensor surface. By using averaging theory methods and the divergence theorem, an approximate model is constructed that describes the asymptotic behaviour of the concentration as a system of ordinary differential equations. The estimate of target molecules is then obtained by solving a nonlinear least squares problem. It is shown that the estimator is strongly consistent and asymptotically normal. An explicit expression is obtained for the asymptotic variance of the estimation error. As an example, the results are illustrated for a novel biosensor built out of protein molecules.

  15. Fluid transport due to nonlinear fluid-structure interaction

    Energy Technology Data Exchange (ETDEWEB)

    Soendergaard Jensen, J.

    1996-08-01

    This work considers nonlinear fluid-structure interaction for a vibrating pipe containing fluid. Transverse pipe vibrations will force the fluid to move relative to the pipe creating uni-directional fluid flow towards the pipe end. The fluid flow induced affects the damping and the stiffness of the pipe. The behavior of the system in response to lateral resonant base excitation is analyzed numerically mode of vibration seems to be most effective for high mean fluid speed, whereas higher modes of vibration can be used to transport fluid with the same fluid speed but with smaller magnitude of pipe vibrations. The effect of the nonlinear geometrical terms is analyzed and these terms are shown to affect the response for higher modes of vibration. Experimental investigations show good agreement with theoretical predictions. (au) 16 refs.

  16. Molecule-by-Molecule Writing Using a Focused Electron Beam

    DEFF Research Database (Denmark)

    Van Dorp, Willem F.; Zhang, Xiaoyan; Feringa, Ben L.;

    2012-01-01

    on graphene can be followed molecule-by-molecule with FEBID. The results show that mechanisms that are inherent to the process inhibit a further increase in control over the process. Hence, our results present the resolution limit of (electron) optical lithography techniques. The writing of isolated...... atoms also be written with an electron beam? We verify this with focused electron-beam-induced deposition (FEBID), a direct-write technique that has the current record for the smallest feature written by (electron) optical lithography. We show that the deposition of an organometallic precursor...

  17. Single-molecule chemistry of metal phthalocyanine on noble metal surfaces.

    Science.gov (United States)

    Li, Zhenyu; Li, Bin; Yang, Jinlong; Hou, Jian Guo

    2010-07-20

    To develop new functional materials and nanoscale electronics, researchers would like to accurately describe and precisely control the quantum state of a single molecule on a surface. Scanning tunneling microscopy (STM), combined with first-principles simulations, provides a powerful technique for acquiring this level of understanding. Traditionally, metal phthalocyanine (MPc) molecules, composed of a metal atom surrounded by a ligand ring, have been used as dyes and pigments. Recently, MPc molecules have shown great promise as components of light-emitting diodes, field-effect transistors, photovoltaic cells, and single-molecule devices. In this Account, we describe recent research on the characterization and control of adsorption and electronic states of a single MPc molecule on noble metal surfaces. In general, the electronic and magnetic properties of a MPc molecule largely depend on the type of metal ion within the phthalocyanine ligand and the type of surface on which the molecule is adsorbed. However, with the STM technique, we can use on-site molecular "surgery" to manipulate the structure and the properties of the molecule. For example, STM can induce a dehydrogenation reaction of the MPc, which allows us to control the Kondo effect, which describes the spin polarization of the molecule and its interaction with the complex environment. A specially designed STM tip can allow researchers to detect certain molecule-surface hybrid states that are not accessible by other techniques. By matching the local orbital symmetry of the STM tip and the molecule, we can generate the negative differential resistance effect in the formed molecular junction. This orbital symmetry based mechanism is extremely robust and does not critically depend on the geometry of the STM tip. In summary, this simple model system, a MPc molecule absorbed on a noble metal surface, demonstrates the power of STM for quantum characterization and manipulation of single molecules, highlighting the

  18. 腹腔镜下保留盆腔自主神经直肠癌根治术对冲洗液及血清中黏附分子、术后脏器功能的影响%Effect of pelvic autonomic nerve preservation in Iaparoscopic radical resection of rectal car-cinoma on adhesion molecules in washing fluid and serum as well as postoperative organ function

    Institute of Scientific and Technical Information of China (English)

    李超; 姚立彬; 孟松; 时林森; 王辉; 朱孝成

    2016-01-01

    目的::研究腹腔镜下保留盆腔自主神经直肠癌根治术对冲洗液及血清中黏附分子、术后脏器功能的影响。方法:选择2013年5月~2015年12月在本院接受全腹腔镜下直肠系膜切除术的86例直肠癌患者进行回顾性分析,37例患者在术中保留盆腔自主神经、纳入 A 组,49例患者在术中未保留盆腔自主神经、纳入B组。术后当天,测定血清肿瘤标志物、黏附分子的含量以及腹腔冲洗液中黏附分子的含量;术后1个月时,评估尿流动力学指标。结果:术后当天,A组患者血清中癌胚抗原(CEA)、糖类抗原199(CA199)、糖类抗原125(CA125)、糖类抗原724(CA724)、细胞间黏附分子-1(ICAM-1)、血管细胞黏附分子-1(VCAM-1)、CD44v6、骨桥蛋白(OPN)的含量以及腹腔冲洗液中 ICAM-1、VCAM-1、CD44v6、OPN的含量均显著低于B组,血清和腹腔冲洗液中 E-钙黏蛋白(E-cadherin)的含量显著高于B组;术后1个月时,A组患者最大尿流率(QMax)、最大膀胱逼尿肌收缩压(PdetMax)、排尿量均显著高于B组,残余尿量显著低于 B组。结论:腹腔镜下直肠癌根治术中保留盆腔自主神经能够减少黏附分子的释放、降低术后排尿功能障碍的发生风险,具有积极的临床应用价值。%[ABSTRACT]Objective:To study the effect of pelvic autonomic nerve preservation in laparoscopic radical resection of rec-tal carcinoma on adhesion molecules in washing fluid and serum as well as postoperative organ function.Methods:86 patients with rectal carcinoma who received laparoscopic total mesorectal excision in our hospital between May 2013 and December 2015 were retrospectively analyzed,37 patients were with intraoperative pelvic autonomic nerve preservation and included in group A,and 49 patients were without intraoperative pelvic autonomic nerve preservation and included in group B.The same day after operation,the levels of tumor markers and adhesion molecules in serum as

  19. Local lateral environment of the molecules at the surface of DMSO-water mixtures

    Science.gov (United States)

    Fábián, Balázs; Idrissi, Abdenacer; Marekha, Bogdan; Jedlovszky, Pál

    2016-10-01

    Molecular dynamics simulations of the liquid-vapour interface of dimethyl sulphoxide (DMSO)-water mixtures of 11 different compositions, including two neat systems are performed on the canonical (N, V, T) ensemble at 298 K. The molecules constituting the surface layer of these systems are selected by means of the identification of the truly interfacial molecules (ITIM) method, and their local lateral environment at the liquid surface is investigated by performing Voronoi analysis. The obtained results reveal that both molecules prefer to be in a mixed local environment, consisting of both kinds of molecules, at the liquid surface, and this preference is even stronger here than in the bulk liquid phase. Neat-like patches, in which a molecule is surrounded by like neighbours, are not found. However, vacancies that are surrounded solely by water molecules are observed at the liquid surface. Our results show that strongly hydrogen bonded DMSO·H2O complexes, known to exist in the bulk phase of these mixtures, are absent from the liquid surface.

  20. Carbon fluxes from hydrothermal vents off Milos, Aegean Volcanic Arc, and the influence of venting on the surrounding ecosystem.

    Science.gov (United States)

    Dando, Paul; Aliani, Stefano; Bianchi, Nike; Kennedy, Hilary; Linke, Peter; Morri, Carla

    2014-05-01

    The island of Milos, in the Aegean Sea, has extensive hydrothermal fields to the east and southeast of the island with additional venting areas near the entrance to and within the central caldera. A calculation of the total area of the vent fields, based on ship and aerial surveys, suggested that the hydrothermal fields occupy 70 km2, twice the area previously estimated. The vents ranged in water depth from the intertidal to 300 m. As a result of the low depths there was abundant free gas release: in places water boiled on the seabed. The stream of gas bubbles rising through the sandy seabed drove a shallow re-circulation of bottom seawater. The majority of the water released with the gas, with a mean pH of 5.5, was re-circulated bottom water that had become acidified in contact with CO2 gas and was often diluted by admixture with the vapour phase from the deeper fluids. The major component of the free gas, 80%, was CO2, with an estimated total flux of 1.5-7.5 x 1012 g a-1. The methane flux, by comparison, was of the order of 1010 g a.-1 Using methane as a tracer it was shown that the major gas export from the vents was below the thermocline towards the southwest, in agreement with the prevailing currents. Areas of hydrothermal brine seepage occurred between the gas vents and occasional brine pools were observed in seabed depressions. Under relatively calm conditions, many of the brine seeps were covered by thick minero-bacterial mats consisting of silica and sulphur and surrounded by mats of diatoms and cyanobacteria. The minerals were not deposited in the absence of bacteria. Storms disrupted the mats, leading to an export of material to the surrounding area. Stable isotope data from sediments and sediment trap material suggested that exported POM was processed by zooplankton. The combined effects of the geothermal heating of the seabed, the large gas flux, variation in the venting and the effect of the brine seeps had a dramatic effect on the surrounding

  1. Endoscopic Ultrasound-guided drainage of an abdominal fluid collection following Whipple's resection

    Institute of Scientific and Technical Information of China (English)

    Asif Jah; Neville Jamieson; Emmanuel Huguet; William Griffiths; Nicholas Carroll; Raaj Praseedom

    2008-01-01

    Percutaneous aspiration and drainage of post-operative abdominal fluid collections is a well established standard technique. However, some fluid collections are not amenable to percutaneous drainage either due to location or the presence of surrounding visceral structures. Endoscopic Ultrasound (EUS) has been widely used for the drainage of pancreatitis-related abdominal fluid collections. However, there are no reports on the use of this technique in the post-operative setting. We report a case where the EUS-guided technique was used to drain a percutaneously inaccessible post-operative collection which had developed after Whipple's resection.

  2. Automated Static Culture System Cell Module Mixing Protocol and Computational Fluid Dynamics Analysis

    Science.gov (United States)

    Kleis, Stanley J.; Truong, Tuan; Goodwin, Thomas J,

    2004-01-01

    This report is a documentation of a fluid dynamic analysis of the proposed Automated Static Culture System (ASCS) cell module mixing protocol. The report consists of a review of some basic fluid dynamics principles appropriate for the mixing of a patch of high oxygen content media into the surrounding media which is initially depleted of oxygen, followed by a computational fluid dynamics (CFD) study of this process for the proposed protocol over a range of the governing parameters. The time histories of oxygen concentration distributions and mechanical shear levels generated are used to characterize the mixing process for different parameter values.

  3. Fluid markers of traumatic brain injury.

    Science.gov (United States)

    Zetterberg, Henrik; Blennow, Kaj

    2015-05-01

    Traumatic brain injury (TBI) occurs when an external force traumatically injures the brain. Whereas severe TBI can be diagnosed using a combination of clinical signs and standard neuroimaging techniques, mild TBI (also called concussion) is more difficult to detect. This is where fluid markers of injury to different cell types and subcellular compartments in the central nervous system come into play. These markers are often proteins, peptides or other molecules with selective or high expression in the brain, which can be measured in the cerebrospinal fluid or blood as they leak out or get secreted in response to the injury. Here, we review the literature on fluid markers of neuronal, axonal and astroglial injury to diagnose mild TBI and to predict clinical outcome in patients with head trauma. We also discuss chronic traumatic encephalopathy, a progressive neurodegenerative disease in individuals with a history of multiple mild TBIs in a biomarker context. This article is part of a Special Issue entitled 'Traumatic Brain Injury'. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Lanczos-driven coupled-cluster damped linear response theory for molecules in polarizable environments

    DEFF Research Database (Denmark)

    List, Nanna Holmgaard; Coriani, Sonia; Kongsted, Jacob

    2014-01-01

    We present an extension of a previously reported implementation of a Lanczos-driven coupled-cluster (CC) damped linear response approach to molecules in condensed phases, where the effects of a surrounding environment are incorporated by means of the polarizable embedding formalism. We...... are specifically motivated by a twofold aim: (i) computation of core excitations in realistic surroundings and (ii) examination of the effect of the differential response of the environment upon excitation solely related to the CC multipliers (herein denoted the J matrix) in computations of excitation energies...

  5. Small molecule fluoride toxicity agonists.

    Science.gov (United States)

    Nelson, James W; Plummer, Mark S; Blount, Kenneth F; Ames, Tyler D; Breaker, Ronald R

    2015-04-23

    Fluoride is a ubiquitous anion that inhibits a wide variety of metabolic processes. Here, we report the identification of a series of compounds that enhance fluoride toxicity in Escherichia coli and Streptococcus mutans. These molecules were isolated by using a high-throughput screen (HTS) for compounds that increase intracellular fluoride levels as determined via a fluoride riboswitch reporter fusion construct. A series of derivatives were synthesized to examine structure-activity relationships, leading to the identification of compounds with improved activity. Thus, we demonstrate that small molecule fluoride toxicity agonists can be identified by HTS from existing chemical libraries by exploiting a natural fluoride riboswitch. In addition, our findings suggest that some molecules might be further optimized to function as binary antibacterial agents when combined with fluoride. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Electric Deflection of Rotating Molecules

    CERN Document Server

    Gershnabel, E

    2010-01-01

    We provide a theory of the deflection of polar and non-polar rotating molecules by inhomogeneous static electric field. Rainbow-like features in the angular distribution of the scattered molecules are analyzed in detail. Furthermore, we demonstrate that one may efficiently control the deflection process with the help of short and strong femtosecond laser pulses. In particular the deflection process may by turned-off by a proper excitation, and the angular dispersion of the deflected molecules can be substantially reduced. We study the problem both classically and quantum mechanically, taking into account the effects of strong deflecting field on the molecular rotations. In both treatments we arrive at the same conclusions. The suggested control scheme paves the way for many applications involving molecular focusing, guiding, and trapping by inhomogeneous fields.

  7. Small Molecule Fluoride Toxicity Agonists

    Science.gov (United States)

    Nelson1, James W.; Plummer, Mark S.; Blount, Kenneth F.; Ames, Tyler D.; Breaker, Ronald R.

    2015-01-01

    SUMMARY Fluoride is a ubiquitous anion that inhibits a wide variety of metabolic processes. Here we report the identification of a series of compounds that enhance fluoride toxicity in Escherichia coli and Streptococcus mutans. These molecules were isolated by using a high-throughput screen (HTS) for compounds that increase intracellular fluoride levels as determined via a fluoride riboswitch-reporter fusion construct. A series of derivatives were synthesized to examine structure-activity relationships, leading to the identification of compounds with improved activity. Thus, we demonstrate that small molecule fluoride toxicity agonists can be identified by HTS from existing chemical libraries by exploiting a natural fluoride riboswitch. In addition, our findings suggest that some molecules might be further optimized to function as binary antibacterial agents when combined with fluoride. PMID:25910244

  8. Laser spectroscopy of cold molecules

    CERN Document Server

    Borri, Simone

    2016-01-01

    This paper reviews the recent results in high-resolution spectroscopy on cold molecules. Laser spectroscopy of cold molecules addresses issues of symmetry violation, like in the search for the electric dipole moment of the electron and the studies on energy differences in enantiomers of chiral species; tries to improve the precision to which fundamental physical constants are known and tests for their possible variation in time and space; tests quantum electrodynamics, and searches for a fifth force. Further, we briefly review the recent technological progresses in the fields of cold molecules and mid-infrared lasers, which are the tools that mainly set the limits for the resolution that is currently attainable in the measurements.

  9. An independent pair-link model of simple fluids

    CERN Document Server

    Bonneville, Richard

    2016-01-01

    A new approach to thermodynamics of simple fluids is presented. The partition function is first expressed in the reciprocal space, it is argued that the links (p,q) between 2 molecules can reasonably in the thermodynamical limit be considered as a set nearly independent objects characterized by the dynamical variables . It is then possible to derive an expression of the pair correlation function. The results, which are independent of the exact shape of the intermolecular potential, are applied to the simple case of hard sphere fluids.

  10. Hematite-bearing materials surrounding Candor Mensa in Candor Chasma, Mars: Implications for hematite origin and post-emplacement modification

    Science.gov (United States)

    Fergason, R. L.; Gaddis, L. R.; Rogers, A. D.

    2014-07-01

    The Valles Marineris canyon system on Mars is of enduring scientific interest in part due to the presence of interior mounds that contain extensive layering and water-altered minerals, such as crystalline gray hematite and hydrated sulfates. The presence of hematite and hydrated sulfate minerals is important because their host rock lithologies provide information about past environments that may have supported liquid water and may have been habitable. This work further defines the association and relationship between hematite-bearing materials and low albedo (presumably aeolian) deposits and layered materials, identifies physical characteristics that are strongly correlated with the presence of hematite, and refines hypotheses for the origin and post-emplacement modification (including transport) of these hematite-bearing and associated materials. There are only three regions surrounding Candor Mensa where hematite has been identified, even though morphologic properties are similar throughout the entire mensa. Three possible explanations for why hematite is only exposed in these regions include: (1) the topographic structure of the mensa walls concentrates hematite at the base of the layered deposits, influencing the ability to detect hematite from orbit; (2) the presence of differing amounts of “dark mantling material” and hematite-free erosional sediment; (3) the potential fracturing of the mensa and the influence of these structures on fluid flow and subsequent digenesis. The observations of hematite-bearing materials in this work support the hypothesis that hematite is eroding from a unit in the Candor Mensa interior layered deposits (ILD) and is being concentrated as a lag deposit adjacent to the lower layers of Candor Mensa and at the base in the form of dark aeolian material. Due to the similar geologic context associated with hematite-bearing and ILD materials throughout the Valles Marineris canyon system, the insight gained from studying these

  11. Hematite-bearing materials surrounding Candor Mensa in Candor Chasma, Mars: Implications for hematite origin and post-emplacement modification

    Science.gov (United States)

    Fergason, Robin L.; Gaddis, Lisa R.; Rogers, A. D.

    2014-01-01

    The Valles Marineris canyon system on Mars is of enduring scientific interest in part due to the presence of interior mounds that contain extensive layering and water-altered minerals, such as crystalline gray hematite and hydrated sulfates. The presence of hematite and hydrated sulfate minerals is important because their host rock lithologies provide information about past environments that may have supported liquid water and may have been habitable. This work further defines the association and relationship between hematite-bearing materials and low albedo (presumably aeolian) deposits and layered materials, identifies physical characteristics that are strongly correlated with the presence of hematite, and refines hypotheses for the origin and post-emplacement modification (including transport) of these hematite-bearing and associated materials. There are only three regions surrounding Candor Mensa where hematite has been identified, even though morphologic properties are similar throughout the entire mensa. Three possible explanations for why hematite is only exposed in these regions include: (1) the topographic structure of the mensa walls concentrates hematite at the base of the layered deposits, influencing the ability to detect hematite from orbit; (2) the presence of differing amounts of “dark mantling material” and hematite-free erosional sediment; (3) the potential fracturing of the mensa and the influence of these structures on fluid flow and subsequent digenesis. The observations of hematite-bearing materials in this work support the hypothesis that hematite is eroding from a unit in the Candor Mensa interior layered deposits (ILD) and is being concentrated as a lag deposit adjacent to the lower layers of Candor Mensa and at the base in the form of dark aeolian material. Due to the similar geologic context associated with hematite-bearing and ILD materials throughout the Valles Marineris canyon system, the insight gained from studying these

  12. Molecule-Based Rheology Switching

    NARCIS (Netherlands)

    Paulusse, Jos M.J.; Sijbesma, Rint P.

    2006-01-01

    Sound-activated switching: The rheological behavior of fluids can be affected by external stimuli, as demonstrated by electrochemically and photochemically induced changes in viscosity and sol–gel transitions. Recently, ultrasound has emerged as a novel rheology switch for supramolecular polymers an

  13. Numerical Analysis of Advanced Displacement in Construction Progress of Tunnel Excavation with Weak Surrounding Rock

    Directory of Open Access Journals (Sweden)

    Qian Zhang

    2013-07-01

    Full Text Available Analysis of advanced displacement in construction progress of tunnel excavation with weak surrounding rock is carried out by numerical method and comparison of model test result. In allusion to the problems of regional landslides and extruded large-deformation seriously impacting the stability of rock mass in construction process of large-section tunnel with weak surrounding rock, the elastic-plastic numerical simulation relying on Liangshui tunnel of Lan-Yu railroad is conducted on mechanical behaviors and deformation steric effect of tunnel construction and the calculation results are compared with the modeling data. The research results show that: the steric effect of excavation face is the dominant factor in the incidence of working face and the stress of surrounding rocks gradually releases from excavation face; the range of 0.5~1 times the cave diameter around rock mass in front of working face is the disturbance range and the key area of stabilization and reinforcement for wake surrounding rock. According to the analysis and construction practice, the supporting structure of large-section tunnel with weak surrounding rock should be established as soon as possible to control the displacement change of surrounding rock in the range of load-bearing ring, reduce disturbance and improve the self-bearing capability of surrounding rock. Because of the distinct excavation steric effect of weak surrounding rock, the secondary lining structure must be established in time to bear the later pressure and restrict the large displacement of surrounding rock. The research results can provide reliable basis for engineering stability control of analogous tunnels.

  14. Microgravity Fluids for Biology, Workshop

    Science.gov (United States)

    Griffin, DeVon; Kohl, Fred; Massa, Gioia D.; Motil, Brian; Parsons-Wingerter, Patricia; Quincy, Charles; Sato, Kevin; Singh, Bhim; Smith, Jeffrey D.; Wheeler, Raymond M.

    2013-01-01

    Microgravity Fluids for Biology represents an intersection of biology and fluid physics that present exciting research challenges to the Space Life and Physical Sciences Division. Solving and managing the transport processes and fluid mechanics in physiological and biological systems and processes are essential for future space exploration and colonization of space by humans. Adequate understanding of the underlying fluid physics and transport mechanisms will provide new, necessary insights and technologies for analyzing and designing biological systems critical to NASAs mission. To enable this mission, the fluid physics discipline needs to work to enhance the understanding of the influence of gravity on the scales and types of fluids (i.e., non-Newtonian) important to biology and life sciences. In turn, biomimetic, bio-inspired and synthetic biology applications based on physiology and biology can enrich the fluid mechanics and transport phenomena capabilities of the microgravity fluid physics community.

  15. Surrounding Risks

    Directory of Open Access Journals (Sweden)

    Mogens Steffensen

    2013-05-01

    Full Text Available Research in insurance and finance was always intersecting although they were originally and generally viewed as separate disciplines. Insurance is about transferring risks between parties such that the burdens of risks are borne by those who can. This makes insurance transactions a beneficial activity for the society. It calls on detection, modelling, valuation, and controlling of risks. One of the main sources of control is diversification of risks and in that respect it becomes an issue in itself to clarify diversifiability of risks. However, many diversifiable risks are not, by nature or by contract design, separable from non-diversifiable risks that are, on the other hand, sometimes traded in financial markets and sometimes not. A key observation is that the economic risk came before the insurance contract: Mother earth destroys and kills incidentally and mercilessly, but the uncertainty of economic consequences can be more or less cleverly distributed by the introduction of an insurance market.

  16. Modelling of fluid-structure interaction with multiphase viscous flows using an immersed-body method

    Science.gov (United States)

    Yang, P.; Xiang, J.; Fang, F.; Pavlidis, D.; Latham, J.-P.; Pain, C. C.

    2016-09-01

    An immersed-body method is developed here to model fluid-structure interaction for multiphase viscous flows. It does this by coupling a finite element multiphase fluid model and a combined finite-discrete element solid model. A coupling term containing the fluid stresses is introduced within a thin shell mesh surrounding the solid surface. The thin shell mesh acts as a numerical delta function in order to help apply the solid-fluid boundary conditions. When used with an advanced interface capturing method, the immersed-body method has the capability to solve problems with fluid-solid interfaces in the presence of multiphase fluid-fluid interfaces. Importantly, the solid-fluid coupling terms are treated implicitly to enable larger time steps to be used. This two-way coupling method has been validated by three numerical test cases: a free falling cylinder in a fluid at rest, elastic membrane and a collapsing column of water moving an initially stationary solid square. A fourth simulation example is of a water-air interface with a floating solid square being moved around by complex hydrodynamic flows including wave breaking. The results show that the immersed-body method is an effective approach for two-way solid-fluid coupling in multiphase viscous flows.

  17. Analytical Modeling of Electric Field Distribution in Dual Material Junctionless Surrounding Gate MOSFETs

    Directory of Open Access Journals (Sweden)

    P. Suveetha Dhanaselvam

    2014-10-01

    Full Text Available In this paper, electric field distribution of the junctionless dual material surrounding gate MOSFETs (JLDMSG is developed. Junctionless is a device that has similar characteristics like junction based devices, but junctionless has a positive flatband voltage with zero electric field. In Surrounding gate MOSFETs gate material surrounds the channel in all direction , therefore it can overcome the short channel effects effectively than other devices. In this paper, surface potential and electric field distribution is modelled. The proposed surface potential model is compared with the existing central potential model. It is observed that the short channel effects (SCE is reduced and the performance is better than the existing method.

  18. Single-molecule magnet engineering

    DEFF Research Database (Denmark)

    Pedersen, Kasper Steen; Bendix, Jesper; Clérac, Rodolphe

    2014-01-01

    to delicately tune, for instance, the properties of molecules that behave as "magnets", the so-called single-molecule magnets (SMMs). Although many interesting SMMs have been prepared by a more or less serendipitous approach, the assembly of predesigned, isolatable molecular entities into higher nuclearity...... complexes constitutes an elegant and fascinating strategy. This Feature article focuses on the use of building blocks or modules (both terms being used indiscriminately) to direct the structure, and therefore also the magnetic properties, of metal ion complexes exhibiting SMM behaviour. This journal...

  19. Nonadiabatic reaction of energetic molecules.

    Science.gov (United States)

    Bhattacharya, Atanu; Guo, Yuanqing; Bernstein, Elliot R

    2010-12-21

    Energetic materials store a large amount of chemical energy that can be readily converted into mechanical energy via decomposition. A number of different ignition processes such as sparks, shocks, heat, or arcs can initiate the excited electronic state decomposition of energetic materials. Experiments have demonstrated the essential role of excited electronic state decomposition in the energy conversion process. A full understanding of the mechanisms for the decomposition of energetic materials from excited electronic states will require the investigation and analysis of the specific topography of the excited electronic potential energy surfaces (PESs) of these molecules. The crossing of multidimensional electronic PESs creates a funnel-like topography, known as conical intersections (CIs). CIs are well established as a controlling factor in the excited electronic state decomposition of polyatomic molecules. This Account summarizes our current understanding of the nonadiabatic unimolecular chemistry of energetic materials through CIs and presents the essential role of CIs in the determination of decomposition pathways of these energetic systems. Because of the involvement of more than one PES, a decomposition process involving CIs is an electronically nonadiabatic mechanism. Based on our experimental observations and theoretical calculations, we find that a nonadiabatic reaction through CIs dominates the initial decomposition process of energetic materials from excited electronic states. Although the nonadiabatic behavior of some polyatomic molecules has been well studied, the role of nonadiabatic reactions in the excited electronic state decomposition of energetic molecules has not been well investigated. We use both nanosecond energy-resolved and femtosecond time-resolved spectroscopic techniques to determine the decomposition mechanism and dynamics of energetic species experimentally. Subsequently, we employ multiconfigurational methodologies (such as, CASSCF

  20. Tunneling Ionization of Diatomic Molecules

    DEFF Research Database (Denmark)

    Svensmark, Jens Søren Sieg

    2016-01-01

    When a molecule is subject to a strong laser field, there is a probability that an electron can escape, even though the electrons are bound by a large potential barrier. This is possible because electrons are quantum mechanical in nature, and they are therefore able to tunnel through potential...... of tunneling ionizaion of molecules is presented and the results of numerical calculations are shown. One perhaps surprising result is, that the frequently used Born-Oppenheimer approximation breaks down for weak fields when describing tunneling ionization. An analytic theory applicable in the weak-field limit...

  1. Technetium-aspirin molecule complexes

    Energy Technology Data Exchange (ETDEWEB)

    El-Shahawy, A.S.; Mahfouz, R.M.; Aly, A.A.M.; El-Zohry, M. (Assiut Univ. (Egypt))

    1993-01-01

    Technetium-aspirin and technetium-aspirin-like molecule complexes were prepared. The structure of N-acetylanthranilic acid (NAA) has been decided through CNDO calculations. The ionization potential and electron affinity of the NAA molecule as well as the charge densities were calculated. The electronic absorption spectra of Tc(V)-Asp and Tc(V)-ATS complexes have two characteristic absorption bands at 450 and 600 nm, but the Tc(V)-NAA spectrum has one characteristic band at 450 nm. As a comparative study, Mo-ATS complex was prepared and its electronic absorption spectrum is comparable with the Tc-ATS complex spectrum. (author).

  2. Recoiling DNA Molecule Simulation & Experiment

    CERN Document Server

    Neto, J C; Mesquita, O N; Neto, Jose Coelho; Dickman, Ronald

    2002-01-01

    Many recent experiments with single DNA molecules are based on force versus extension measurements and involve tethering a microsphere to one of its extremities and the other to a microscope coverglass. In this work we show that similar results can also be obtained by studying the recoil dynamics of the tethered microspheres. Computer simulations of the corresponding Langevin equation indicate which assumptions are required for a reliable analysis of the experimental recoil curves. We have measured the persistence length A of single naked DNA molecules and DNA-Ethidium Bromide complexes using this approach.

  3. Exotic helium molecules; Molecules exotiques d'helium

    Energy Technology Data Exchange (ETDEWEB)

    Portier, M

    2007-12-15

    We study the photo-association of an ultracold cloud of magnetically trapped helium atoms: pairs of colliding atoms interact with one or two laser fields to produce a purely long range {sup 4}He{sub 2}(2{sup 3}S{sub 1}-2{sup 3}P{sub 0}) molecule, or a {sup 4}He{sub 2}(2{sup 3}S{sub 1}-2{sup 3}S{sub 1}) long range molecule. Light shifts in one photon photo-association spectra are measured and studied as a function of the laser polarization and intensity, and the vibrational state of the excited molecule. They result from the light-induced coupling between the excited molecule, and bound and scattering states of the interaction between two metastable atoms. Their analysis leads to the determination of the scattering length a = (7.2 {+-} 0.6) ruling collisions between spin polarized atoms. The two photon photo-association spectra show evidence of the production of polarized, long-range {sup 4}He{sub 2}(2{sup 3}S{sub 1}-2{sup 3}S{sub 1}) molecules. They are said to be exotic as they are made of two metastable atoms, each one carrying a enough energy to ionize the other. The corresponding lineshapes are calculated and decomposed in sums and products of Breit-Wigner and Fano profiles associated to one and two photon processes. The experimental spectra are fit, and an intrinsic lifetime {tau} = (1.4 {+-} 0.3) {mu}s is deduced. It is checked whether this lifetime could be limited by spin-dipole induced Penning autoionization. This interpretation requires that there is a quasi-bound state close to the dissociation threshold in the singlet interaction potential between metastable helium atoms for the theory to match the experiment. (author)

  4. Electrorheologic fluids; Fluidos electroreologicos

    Energy Technology Data Exchange (ETDEWEB)

    Rejon G, Leonardo; Lopez G, Francisco; Montoya T, Gerardo [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Manero B, Octavio [Instituto de Investigaciones en Materiales, UNAM.(Mexico)

    2003-07-01

    The present article has as an objective to offer a review of the research work made in the Instituto de Investigaciones Electricas (IIE) on the study of the electrorheologic fluids whose flow properties can abruptly change in the presence of an electric field when this is induced by a direct current. The electrorheologic fluids have their main application in the manufacture of self-controlling damping systems. [Spanish] El presente articulo tiene por objetivo ofrecer una resena de los trabajos de investigacion realizados en el Instituto de Investigaciones Electricas (IIE) sobre el estudio de los fluidos electroreologicos cuyas propiedades de flujo pueden cambiar abruptamente en presencia de un campo electrico cuando este es inducido por una corriente directa. Los fluidos electroreologicos tienen su principal aplicacion en la fabricacion de sistemas de amortiguamiento autocontrolables.

  5. COUPLED CHEMOTAXIS FLUID MODEL

    KAUST Repository

    LORZ, ALEXANDER

    2010-06-01

    We consider a model system for the collective behavior of oxygen-driven swimming bacteria in an aquatic fluid. In certain parameter regimes, such suspensions of bacteria feature large-scale convection patterns as a result of the hydrodynamic interaction between bacteria. The presented model consist of a parabolicparabolic chemotaxis system for the oxygen concentration and the bacteria density coupled to an incompressible Stokes equation for the fluid driven by a gravitational force of the heavier bacteria. We show local existence of weak solutions in a bounded domain in d, d = 2, 3 with no-flux boundary condition and in 2 in the case of inhomogeneous Dirichlet conditions for the oxygen. © 2010 World Scientific Publishing Company.

  6. Galilean relativistic fluid mechanics

    CERN Document Server

    Ván, Péter

    2015-01-01

    Single component Galilean-relativistic (nonrelativistic) fluids are treated independently of reference frames. The basic fields are given, their balances, thermodynamic relations and the entropy production is calculated. The usual relative basic fields, the mass, momentum and energy densities, the diffusion current density, the pressure tensor and the heat flux are the time- and spacelike components of the third order mass-momentum-energy density tensor according to a velocity field. The transformation rules of the basic fields are derived and prove that the non-equilibrium thermodynamic background theory, that is the Gibbs relation, extensivity condition and the entropy production is absolute, that is independent of the reference frame and also of the fluid velocity. --- Az egykomponensu Galilei-relativisztikus (azaz nemrelativisztikus) disszipativ folyadekokat vonatkoztatasi rendszertol fuggetlenul targyaljuk. Megadjuk az alapmennyisegeket, ezek merlegeit, a termodinamikai osszefuggeseket es kiszamoljuk az ...

  7. Zinc Determination in Pleural Fluid

    OpenAIRE

    Nazan DEMİR; DEMİR, Yaşar

    2000-01-01

    In this study, an enzymatic zinc determination method was applied to pleural fluid, the basis of which was the regaining of the activity of apo carbonic anhydrase by the zinc present in the sample. The method was used for pleural fluid zinc determination in order to show the application to body fluids other than serum. For this purpose, pleural fluids were obtained from 20 patients and zinc concentrations were determined. Carbonic anhydrase was purified by affinity chromatography from bovine ...

  8. Handbook of hydraulic fluid technology

    CERN Document Server

    Totten, George E

    2011-01-01

    ""The Handbook of Hydraulic Fluid Technology"" serves as the foremost resource for designing hydraulic systems and for selecting hydraulic fluids used in engineering applications. Featuring new illustrations, data tables, as well as practical examples, this second edition is updated with essential information on the latest hydraulic fluids and testing methods. The detailed text facilitates unparalleled understanding of the total hydraulic system, including important hardware, fluid properties, and hydraulic lubricants. Written by worldwide experts, the book also offers a rigorous overview of h

  9. Amniotic fluid embolism

    OpenAIRE

    Thongrong, Cattleya; Kasemsiri, Pornthep; Hofmann, James P; Bergese, Sergio D.; Thomas J Papadimos; Gracias, Vicente H.; Adolph, Michael D.; Stawicki, Stanislaw P A

    2013-01-01

    Amniotic fluid embolism (AFE) is an unpredictable and as-of-yet unpreventable complication of maternity. With its low incidence it is unlikely that any given practitioner will be confronted with a case of AFE. However, this rare occurrence carries a high probability of serious sequelae including cardiac arrest, ARDS, coagulopathy with massive hemorrhage, encephalopathy, seizures, and both maternal and infant mortality. In this review the current state of medical knowledge about AFE is outline...

  10. Galilean relativistic fluid mechanics

    OpenAIRE

    Ván, Péter

    2015-01-01

    Single component nonrelativistic dissipative fluids are treated independently of reference frames and flow-frames. First the basic fields and their balances, then the related thermodynamic relations and the entropy production are calculated and the linear constitutive relations are given. The usual basic fields of mass, momentum, energy and their current densities, the heat flux, pressure tensor and diffusion flux are the time- and spacelike components of the third order mass-momentum-energy ...

  11. Physics of Fluids

    OpenAIRE

    Luton, J. A.; Ragab, Saad A.

    1997-01-01

    The interaction of vortices passing near a solid surface has been examined using direct numerical simulation. The configuration studied is a counter-rotating vortex pair approaching a wall in an otherwise quiescent fluid. The focus of these simulations is on the three-dimensional effects, of which little is known. To the authors' knowledge, this is the first three-dimensional simulation that lends support to the short-wavelength instability of the secondary vortex. It has been shown how this ...

  12. Soluble oil cutting fluid

    Energy Technology Data Exchange (ETDEWEB)

    Rawlinson, A.P.; White, J.

    1987-06-23

    A soluble oil, suitable when diluted with water, for use as a cutting fluid comprises an alkali or alkaline-earth metal alkyl benzene sulphonate, a fatty acid diethanolamide, a mixed alkanolamine borate, a polyisobutenesuccinimide and a major proportion of mineral oil. The soluble oil is relatively stable without the need for a conventional coupling agent and some soluble oil emulsions are bio-static even though conventional biocides are not included.

  13. Fluid Dynamics and Viscosity in Strongly Correlated Fluids

    CERN Document Server

    Schaefer, Thomas

    2014-01-01

    We review the modern view of fluid dynamics as an effective low energy, long wavelength theory of many body systems at finite temperature. We introduce the notion of a nearly perfect fluid, defined by a ratio $\\eta/s$ of shear viscosity to entropy density of order $\\hbar/k_B$ or less. Nearly perfect fluids exhibit hydrodynamic behavior at all distances down to the microscopic length scale of the fluid. We summarize arguments that suggest that there is fundamental limit to fluidity, and review the current experimental situation with regard to measurements of $\\eta/s$ in strongly coupled quantum fluids.

  14. Downhole Fluid Analyzer Development

    Energy Technology Data Exchange (ETDEWEB)

    Bill Turner

    2006-11-28

    A novel fiber optic downhole fluid analyzer has been developed for operation in production wells. This device will allow real-time determination of the oil, gas and water fractions of fluids from different zones in a multizone or multilateral completion environment. The device uses near infrared spectroscopy and induced fluorescence measurement to unambiguously determine the oil, water and gas concentrations at all but the highest water cuts. The only downhole components of the system are the fiber optic cable and windows. All of the active components--light sources, sensors, detection electronics and software--will be located at the surface, and will be able to operate multiple downhole probes. Laboratory testing has demonstrated that the sensor can accurately determine oil, water and gas fractions with a less than 5 percent standard error. Once installed in an intelligent completion, this sensor will give the operating company timely information about the fluids arising from various zones or multilaterals in a complex completion pattern, allowing informed decisions to be made on controlling production. The research and development tasks are discussed along with a market analysis.

  15. Astrophysical fluid dynamics

    Science.gov (United States)

    Ogilvie, Gordon I.

    2016-06-01

    > These lecture notes and example problems are based on a course given at the University of Cambridge in Part III of the Mathematical Tripos. Fluid dynamics is involved in a very wide range of astrophysical phenomena, such as the formation and internal dynamics of stars and giant planets, the workings of jets and accretion discs around stars and black holes and the dynamics of the expanding Universe. Effects that can be important in astrophysical fluids include compressibility, self-gravitation and the dynamical influence of the magnetic field that is `frozen in' to a highly conducting plasma. The basic models introduced and applied in this course are Newtonian gas dynamics and magnetohydrodynamics (MHD) for an ideal compressible fluid. The mathematical structure of the governing equations and the associated conservation laws are explored in some detail because of their importance for both analytical and numerical methods of solution, as well as for physical interpretation. Linear and nonlinear waves, including shocks and other discontinuities, are discussed. The spherical blast wave resulting from a supernova, and involving a strong shock, is a classic problem that can be solved analytically. Steady solutions with spherical or axial symmetry reveal the physics of winds and jets from stars and discs. The linearized equations determine the oscillation modes of astrophysical bodies, as well as their stability and their response to tidal forcing.

  16. Corrosion in supercritical fluids

    Energy Technology Data Exchange (ETDEWEB)

    Propp, W.A.; Carleson, T.E.; Wai, Chen M.; Taylor, P.R.; Daehling, K.W.; Huang, Shaoping; Abdel-Latif, M.

    1996-05-01

    Integrated studies were carried out in the areas of corrosion, thermodynamic modeling, and electrochemistry under pressure and temperature conditions appropriate for potential applications of supercritical fluid (SCF) extractive metallurgy. Carbon dioxide and water were the primary fluids studied. Modifiers were used in some tests; these consisted of 1 wt% water and 10 wt% methanol for carbon dioxide and of sulfuric acid, sodium sulfate, ammonium sulfate, and ammonium nitrate at concentrations ranging from 0.00517 to 0.010 M for the aqueous fluids. The materials studied were Types 304 and 316 (UNS S30400 and S31600) stainless steel, iron, and AISI-SAE 1080 (UNS G10800) carbon steel. The thermodynamic modeling consisted of development of a personal computer-based program for generating Pourbaix diagrams at supercritical conditions in aqueous systems. As part of the model, a general method for extrapolating entropies and related thermodynamic properties from ambient to SCF conditions was developed. The experimental work was used as a tool to evaluate the predictions of the model for these systems. The model predicted a general loss of passivation in iron-based alloys at SCF conditions that was consistent with experimentally measured corrosion rates and open circuit potentials. For carbon-dioxide-based SCFs, measured corrosion rates were low, indicating that carbon steel would be suitable for use with unmodified carbon dioxide, while Type 304 stainless steel would be suitable for use with water or methanol as modifiers.

  17. Geophysical fluid dynamics

    CERN Document Server

    Pedlosky, Joseph

    1979-01-01

    The content of this book is based, largely, on the core curriculum in geophys­ ical fluid dynamics which I and my colleagues in the Department of Geophysical Sciences at The University of Chicago have taught for the past decade. Our purpose in developing a core curriculum was to provide to advanced undergraduates and entering graduate students a coherent and systematic introduction to the theory of geophysical fluid dynamics. The curriculum and the outline of this book were devised to form a sequence of courses of roughly one and a half academic years (five academic quarters) in length. The goal of the sequence is to help the student rapidly advance to the point where independent study and research are practical expectations. It quickly became apparent that several topics (e. g. , some aspects of potential theory) usually thought of as forming the foundations of a fluid-dynamics curriculum were merely classical rather than essential and could be, however sadly, dispensed with for our purposes. At the same ti...

  18. Geophysical fluid dynamics

    CERN Document Server

    Pedlosky, Joseph

    1982-01-01

    The content of this book is based, largely, on the core curriculum in geophys­ ical fluid dynamics which land my colleagues in the Department of Geophysical Sciences at The University of Chicago have taught for the past decade. Our purpose in developing a core curriculum was to provide to advanced undergraduates and entering graduate students a coherent and systematic introduction to the theory of geophysical fluid dynamics. The curriculum and the outline of this book were devised to form a sequence of courses of roughly one and a half academic years (five academic quarters) in length. The goal of the sequence is to help the student rapidly advance to the point where independent study and research are practical expectations. It quickly became apparent that several topics (e. g. , some aspects of potential theory) usually thought of as forming the foundations of a fluid-dynamics curriculum were merely classical rather than essential and could be, however sadly, dispensed with for our purposes. At the same tim...

  19. Galilean relativistic fluid mechanics

    Science.gov (United States)

    Ván, P.

    2017-01-01

    Single-component nonrelativistic dissipative fluids are treated independently of reference frames and flow-frames. First the basic fields and their balances are derived, then the related thermodynamic relations and the entropy production are calculated and the linear constitutive relations are given. The usual basic fields of mass, momentum, energy and their current densities, the heat flux, pressure tensor and diffusion flux are the time- and spacelike components of the third-order mass-momentum-energy density-flux four-tensor. The corresponding Galilean transformation rules of the physical quantities are derived. It is proved that the non-equilibrium thermodynamic frame theory, including the thermostatic Gibbs relation and extensivity condition and also the entropy production, is independent of the reference frame and also the flow-frame of the fluid. The continuity-Fourier-Navier-Stokes equations are obtained almost in the traditional form if the flow of the fluid is fixed to the temperature. This choice of the flow-frame is the thermo-flow. A simple consequence of the theory is that the relation between the total, kinetic and internal energies is a Galilean transformation rule.

  20. The Viscosity of Polymeric Fluids.

    Science.gov (United States)

    Perrin, J. E.; Martin, G. C.

    1983-01-01

    To illustrate the behavior of polymeric fluids and in what respects they differ from Newtonian liquids, an experiment was developed to account for the shear-rate dependence of non-Newtonian fluids. Background information, procedures, and results are provided for the experiment. Useful in transport processes, fluid mechanics, or physical chemistry…

  1. CT of retrorenal fluid collections

    Energy Technology Data Exchange (ETDEWEB)

    Love, L.; Demos, T.C.; Posniak, H.

    1985-07-01

    Fluid collections dorsal to one or both kidneys are often observed on CT. Most of these collections are located in the posterior pararenal space, but occasionally fluid collections that do not originate in this space also occur. The authors review retrorenal fluid collections with explanations for their occurrence.

  2. Basic concepts of fluid responsiveness

    NARCIS (Netherlands)

    T.G.V. Cherpanath (Thomas); B.F. Geerts (Bart); W.K. Lagrand (Wim); M.J. Schultz (Marcus); A.B.J. Groeneveld (Johan)

    2013-01-01

    textabstractPredicting fluid responsiveness, the response of stroke volume to fluid loading, is a relatively novel concept that aims to optimise circulation, and as such organ perfusion, while avoiding futile and potentially deleterious fluid administrations in critically ill patients. Dynamic param

  3. Fluid transport due to nonlinear fluid-structure interaction

    DEFF Research Database (Denmark)

    Jensen, Jakob Søndergaard

    1997-01-01

    This work considers nonlinear fluid-structure interaction for a vibrating pipe containing fluid. Transverse pipe vibrations will force the fluid to move relative to the pipe creating unidirectional fluid flow towards the pipe end. The fluid flow induced affects the damping and the stiffness...... of the pipe. The behavior of the system in response to lateral resonant base excitation is analysed numerically and by the use of a perturbation method (multiple scales). Exciting the pipe in the fundamental mode of vibration seems to be most effective for transferring energy from the shaker to the fluid......, whereas higher modes of vibration can be used to transport fluid with pipe vibrations of smaller amplitude. The effect of the nonlinear geometrical terms is analysed and these terms are shown to affect the response for higher modes of vibration. Experimental investigations show good agreement...

  4. A new and effective method for thermostatting confined fluids

    Energy Technology Data Exchange (ETDEWEB)

    De Luca, Sergio; Todd, B. D., E-mail: btodd@swin.edu.au [Department of Mathematics, Faculty of Science, Engineering and Technology, and Centre for Molecular Simulation, Swinburne University of Technology, Melbourne, Victoria 3122 (Australia); Hansen, J. S. [DNRF Center “Glass and Time,” IMFUFA, Department of Science, Systems and Models, Roskilde University, DK-4000 Roskilde (Denmark); Daivis, Peter J. [School of Applied Sciences, RMIT University, Melbourne, Victoria 3001 (Australia)

    2014-02-07

    We present a simple thermostatting method suitable for nanoconfined fluid systems. Two conventional strategies involve thermostatting the fluid directly or employing a thermal wall that couples only the wall atoms with the thermostat. When only a thermal wall is implemented, the temperature control of the fluid is true to the actual experiment and the heat is transferred from the fluid to the walls. However, for large or complex systems it can often be computationally prohibitive to employ thermal walls. To overcome this limitation many researchers choose to freeze wall atoms and instead apply a synthetic thermostat to the fluid directly through the equations of motion. This, however, can have serious consequences for the mechanical, thermodynamic, and dynamical properties of the fluid by introducing unphysical behaviour into the system [Bernardi et al., J. Chem. Phys. 132, 244706 (2010)]. In this paper, we propose a simple scheme which enables working with both frozen walls and naturally thermostatted liquids. This is done by superimposing the walls with oscillating particles, which vibrate on the edge of the fluid control volume. These particles exchange energy with the fluid molecules, but do not interact with wall atoms or each other, thus behaving as virtual particles. Their displacements violate the Lindemann criterion for melting, in such a way that the net effect would not amount to an additional confining surface. One advantage over standard techniques is the reduced computational cost, particularly for large walls, since they can be kept rigid. Another advantage over accepted strategies is the opportunity to freeze complex charged walls such as β-cristobalite. The method furthermore overcomes the problem with polar fluids such as water, as thermalized charged surfaces require higher spring constants to preserve structural stability, due to the effects of strong Coulomb interactions, thus inevitably degrading the thermostatting efficiency.

  5. A new and effective method for thermostatting confined fluids

    Science.gov (United States)

    De Luca, Sergio; Todd, B. D.; Hansen, J. S.; Daivis, Peter J.

    2014-02-01

    We present a simple thermostatting method suitable for nanoconfined fluid systems. Two conventional strategies involve thermostatting the fluid directly or employing a thermal wall that couples only the wall atoms with the thermostat. When only a thermal wall is implemented, the temperature control of the fluid is true to the actual experiment and the heat is transferred from the fluid to the walls. However, for large or complex systems it can often be computationally prohibitive to employ thermal walls. To overcome this limitation many researchers choose to freeze wall atoms and instead apply a synthetic thermostat to the fluid directly through the equations of motion. This, however, can have serious consequences for the mechanical, thermodynamic, and dynamical properties of the fluid by introducing unphysical behaviour into the system [Bernardi et al., J. Chem. Phys. 132, 244706 (2010)]. In this paper, we propose a simple scheme which enables working with both frozen walls and naturally thermostatted liquids. This is done by superimposing the walls with oscillating particles, which vibrate on the edge of the fluid control volume. These particles exchange energy with the fluid molecules, but do not interact with wall atoms or each other, thus behaving as virtual particles. Their displacements violate the Lindemann criterion for melting, in such a way that the net effect would not amount to an additional confining surface. One advantage over standard techniques is the reduced computational cost, particularly for large walls, since they can be kept rigid. Another advantage over accepted strategies is the opportunity to freeze complex charged walls such as β-cristobalite. The method furthermore overcomes the problem with polar fluids such as water, as thermalized charged surfaces require higher spring constants to preserve structural stability, due to the effects of strong Coulomb interactions, thus inevitably degrading the thermostatting efficiency.

  6. Small Molecule PET-Radiopharmaceuticals

    NARCIS (Netherlands)

    Elsinga, Philip H.; Dierckx, Rudi A. J. O.

    2014-01-01

    This review describes several aspects required for the development of small molecule PET-tracers. Design and selection criteria are important to consider before starting to develop novel PET-tracers. Principles and latest trends in C-11 and F-18-radiochemistry are summarized. In addition an update o

  7. Azobenzene-functionalized cascade molecules

    DEFF Research Database (Denmark)

    Archut, A.; Vogtle, F.; De Cola, L.;

    1998-01-01

    Cascade molecules bearing up to 32 azobenzene groups in the periphery have been prepared from poly(propylene imine) dendrimers and N-hydroxysuccinimide esters. The dendritic azobenzene species show similar isomerization properties as the corresponding azobenzene monomers. The all-E azobenzene...

  8. WHAT ARE THE MOLECULES DOING?

    African Journals Online (AJOL)

    Temechegn

    Johnstone's identification of teaching and learning difficulties derived from the three levels of description in .... and in aqueous solution the molecules (say HA) dissociate into a hydrogen ion, H+ (aq) and an anion, A-(aq). This is a chemical ...

  9. Small Molecules Target Carcinogenic Proteins

    Science.gov (United States)

    Gradinaru, Claudiu

    2009-03-01

    An ingenious cellular mechanism of effecting protein localization is prenylation: the covalent attachment of a hydrophobic prenyl group to a protein that facilitates protein association with cell membranes. Fluorescence microscopy was used to investigate whether the oncogenic Stat3 protein can undergo artificial prenylation via high-affinity prenylated small-molecule binding agents and thus be rendered inactive by localization at the plasma membrane instead of nucleus. The measurements were performed on a home-built instrument capable of recording simultaneously several optical parameters (lifetime, polarization, color, etc) and with single-molecule sensitivity. A pH-invariant fluorescein derivative with double moiety was designed to bridge a prenyl group and a small peptide that binds Stat3 with high affinity. Confocal fluorescence images show effective localization of the ligand to the membrane of liposomes. Stat3 predominantly localizes at the membrane only in the presence of the prenylated ligand. Single-molecule FRET (fluorescence resonance energy transfer) between donor-labeled prenylated agents and acceptor-labeled, surface tethered Stat3 protein is used to determine the dynamic heterogeneity of the protein-ligand interaction and follow individual binding-unbinding events in real time. The data indicates that molecules can effect protein localization, validating a therapeutic design that influences protein activity via induced localization.

  10. Analysis of nonlinear dynamic character in the surrounding rock system for deep buried underground engineering

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yu; PENG Hai-you

    2010-01-01

    Combining the field monitoring results of a deep-buried tunnel in Chongqing,the dynamic characteristics of the surrounding rock system under high in situ stress was analyzed by phase space reconstruction, calculating correlation dimension, Kolmogorov entropy and largest Lyapunov exponents. Both the Kolmogorov entropy and largest Lyapunov exponents show that the surrounding rock system is a chaotic one. Based on this, a local model was applied to predict surrounding rock displacement, and a nonlinear dynamic model was derived to forecast the interaction of the surrounding rock and support structure. The local method was found to have an extremely small total error. Also, the nonlinear dynamic model forecasting curves agree with the monitoring ones very well. It is proved that the nonlinear dynamic characteristic study is very important in analyzing rock stability and predicting the evolution of rock systems.

  11. The relation between residential property and its surroundings and day- and night-time residential burglary

    NARCIS (Netherlands)

    Montoya, Lorena; Junger, Marianne; Ongena, Yfke

    2016-01-01

    This article examines how residential property and its surroundings influence day- and night-time residential burglary. Crime Prevention Through Environmental Design (CPTED) principles of territoriality, surveillance, access control, target hardening, image maintenance, and activity support underpin

  12. Effect of surface contamination on osseointegration of dental implants surrounded by circumferential bone defects.

    LENUS (Irish Health Repository)

    Mohamed, Seif

    2010-05-01

    This study was designed to evaluate the effect of surface contamination on osseointegration of dental implants surrounded by a circumferential bone defect and to compare osseointegration around Osseotite with that around Nanotite implants.

  13. Particulate capture efficiency of a vegetative environmental buffer surrounding an animal feeding operation

    Science.gov (United States)

    Particulate matter emitted from tunnel-ventilated animal feeding operations (AFOs) is known to transport malodorous compounds. As a mitigation strategy, vegetative environmental buffers (VEBs) are often installed surrounding AFOs to capture particulates and induce lofting and dispersion. Currently, ...

  14. Hurricane Gustav Aerial Photography: Rapid ResponseImagery of the Surrounding Regions After Landfall

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The imagery posted on this site is of the surrounding regionsafter Hurricane Gustav made landfall. The aerial photography missions wereconducted by the NOAA Remote...

  15. Hurricane Dennis Aerial Photography: Draft Image Mosaics of the Florida Panhandle and Surrounding Regions After Landfall

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The imagery posted on this site is of the Florida panhandle and surrounding regions after Hurricane Dennis made landfall. The regions photographed range from...

  16. Review of roadway control in soft surrounding rock under dynamic pressure

    Institute of Scientific and Technical Information of China (English)

    侯朝炯

    2003-01-01

    The basic characteristics of the soft rock roadway under the dynamic pressure are analyzed. At the same time, the three fundamental approaches for controlling the surrounding rock are proposed, which are improving the surrounding rock strength, lowering the rock mass stress and selecting the reasonable supporting technology. The research results are elucidated, including the distribution of the surrounding rock plastic zone, the movement and damage of the surrounding rock under the dynamic pressure, controlling the floor heave through reinforcing the roadway walls and corners, the new route to develop the roadway metal supporting technique, the key theory and technique for the bolt supporting in the coal roadway, the performance and prospect of the ZKD high-water-content quick-setting material, and so on. Finally, some personally views are put forward about the roadway metal supporting, bolt supporting, new material and the stress-relief under the high stress condition.

  17. Targeting Alzheimer's disease by investigating previously unexplored chemical space surrounding the cholinesterase inhibitor donepezil

    CSIR Research Space (South Africa)

    Van Greunen, DG

    2017-02-01

    Full Text Available A series of twenty seven acetylcholinesterase inhibitors, as potential agents for the treatment of Alzheimer's disease, were designed and synthesised based upon previously unexplored chemical space surrounding the molecular skeleton of the drug...

  18. Divergence in cis-regulatory sequences surrounding the opsin gene arrays of African cichlid fishes

    National Research Council Canada - National Science Library

    O'Quin, Kelly E; Smith, Daniel; Naseer, Zan; Schulte, Jane; Engel, Samuel D; Loh, Yong-Hwee E; Streelman, J Todd; Boore, Jeffrey L; Carleton, Karen L

    2011-01-01

    .... We use phylogenetic footprinting and shadowing to examine divergence in conserved non-coding elements, promoter sequences, and 3'-UTRs surrounding each opsin in search of candidate cis-regulatory...

  19. Hurricane Ike Aerial Photography: Rapid ResponseImagery of the Surrounding Regions After Landfall

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The imagery posted on this site is of the surrounding regionsafter Hurricane Ike made landfall. The aerial photography missions wereconducted by the NOAA Remote...

  20. Modelling of the effect of discontinuities on the extent of the fracture zone surrounding deep tunnels

    CSIR Research Space (South Africa)

    Sellers, EJ

    2000-10-01

    Full Text Available A series of physical and numerical model tests were performed to investigate the behaviour of the rock surrounding circular excavations under high confining pressures. The aim was to provide information on the formation of fractures around deep...