WorldWideScience

Sample records for biology moving fluids

  1. Cosmology with moving bimetric fluids

    CERN Document Server

    García-García, Carlos; Martín-Moruno, Prado

    2016-01-01

    We study cosmological implications of bigravity and massive gravity solutions with non-simultaneously diagonal metrics by considering the generalized Gordon and Kerr-Schild ansatzes. The scenario that we obtain is equivalent to that of General Relativity with additional non-comoving perfect fluids. We show that the most general ghost-free bimetric theory generates three kinds of effective fluids whose equations of state are fixed by a function of the ansatz. Different choices of such function allow to reproduce the behaviour of different dark fluids. In particular, the Gordon ansatz is suitable for the description of various kinds of slowly-moving fluids, whereas the Kerr-Schild one is shown to describe a null dark energy component. The motion of those dark fluids with respect to the CMB is shown to generate, in turn, a relative motion of baryonic matter with respect to radition which contributes to the CMB anisotropies. CMB dipole observations are able to set stringent limits on the dark sector described by ...

  2. Cosmology with moving bimetric fluids

    OpenAIRE

    García-García, Carlos; Maroto, Antonio L.; Martín-Moruno, Prado

    2016-01-01

    We study cosmological implications of bigravity and massive gravity solutions with non-simultaneously diagonal metrics by considering the generalized Gordon and Kerr-Schild ansatzes. The scenario that we obtain is equivalent to that of General Relativity with additional non-comoving perfect fluids. We show that the most general ghost-free bimetric theory generates three kinds of effective fluids whose equations of state are fixed by a function of the ansatz. Different choices of such function...

  3. 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.

  4. Multiphase flow of immiscible fluids on unstructured moving meshes

    OpenAIRE

    Misztal, Marek Krzysztof; Erleben, Kenny; Bargteil, Adam; Fursund, Jens; Christensen , Brian Bunch; Bærentzen, Jakob Andreas; Bridson, Robert

    2012-01-01

    In this paper, we present a method for animating multiphase flow of immiscible fluids using unstructured moving meshes. Our underlying discretization is an unstructured tetrahedral mesh, the deformable simplicial complex (DSC), that moves with the flow in a Lagrangian manner. Mesh optimization operations improve element quality and avoid element inversion. In the context of multiphase flow, we guarantee that every element is occupied by a single fluid and, consequently, the interface between ...

  5. Multiphase Flow of Immiscible Fluids on Unstructured Moving Meshes

    DEFF Research Database (Denmark)

    Misztal, Marek Krzysztof; Erleben, Kenny; Bargteil, Adam;

    2013-01-01

    In this paper, we present a method for animating multiphase flow of immiscible fluids using unstructured moving meshes. Our underlying discretization is an unstructured tetrahedral mesh, the deformable simplicial complex (DSC), that moves with the flow in a Lagrangian manner. Mesh optimization...... operations improve element quality and avoid element inversion. In the context of multiphase flow, we guarantee that every element is occupied by a single fluid and, consequently, the interface between fluids is represented by a set of faces in the simplicial complex. This approach ensures that the...

  6. Multiphase Flow of Immiscible Fluids on Unstructured Moving Meshes

    DEFF Research Database (Denmark)

    Misztal, Marek Krzysztof; Erleben, Kenny; Bargteil, Adam;

    2012-01-01

    In this paper, we present a method for animating multiphase flow of immiscible fluids using unstructured moving meshes. Our underlying discretization is an unstructured tetrahedral mesh, the deformable simplicial complex (DSC), that moves with the flow in a Lagrangian manner. Mesh optimization...... operations improve element quality and avoid element inversion. In the context of multiphase flow, we guarantee that every element is occupied by a single fluid and, consequently, the interface between fluids is represented by a set of faces in the simplicial complex. This approach ensures that the...

  7. Multiphase flow of immiscible fluids on unstructured moving meshes

    DEFF Research Database (Denmark)

    Misztal, Marek Krzysztof; Erleben, Kenny; Bargteil, Adam;

    2012-01-01

    In this paper, we present a method for animating multiphase flow of immiscible fluids using unstructured moving meshes. Our underlying discretization is an unstructured tetrahedral mesh, the deformable simplicial complex (DSC), that moves with the flow in a Lagrangian manner. Mesh optimization...... operations improve element quality and avoid element inversion. In the context of multiphase flow, we guarantee that every element is occupied by a single fluid and, consequently, the interface between fluids is represented by a set of faces in the simplicial complex. This approach ensures that the...

  8. Multiphase flow of immiscible fluids on unstructured moving meshes.

    Science.gov (United States)

    Misztal, Marek Krzysztof; Erleben, Kenny; Bargteil, Adam; Fursund, Jens; Christensen, Brian Bunch; Bærentzen, Jakob Andreas; Bridson, Robert

    2014-01-01

    In this paper, we present a method for animating multiphase flow of immiscible fluids using unstructured moving meshes. Our underlying discretization is an unstructured tetrahedral mesh, the deformable simplicial complex (DSC), that moves with the flow in a Lagrangian manner. Mesh optimization operations improve element quality and avoid element inversion. In the context of multiphase flow, we guarantee that every element is occupied by a single fluid and, consequently, the interface between fluids is represented by a set of faces in the simplicial complex. This approach ensures that the underlying discretization matches the physics and avoids the additional book-keeping required in grid-based methods where multiple fluids may occupy the same cell. Our Lagrangian approach naturally leads us to adopt a finite element approach to simulation, in contrast to the finite volume approaches adopted by a majority of fluid simulation techniques that use tetrahedral meshes. We characterize fluid simulation as an optimization problem allowing for full coupling of the pressure and velocity fields and the incorporation of a second-order surface energy. We introduce a preconditioner based on the diagonal Schur complement and solve our optimization on the GPU. We provide the results of parameter studies as well as a performance analysis of our method, together with suggestions for performance optimization. PMID:24201322

  9. Solving Fluid Flow Problems on Moving and Adaptive Overlapping Grids

    Energy Technology Data Exchange (ETDEWEB)

    Henshaw, W

    2005-07-28

    Solution of fluid dynamics problems on overlapping grids will be discussed. An overlapping grid consists of a set of structured component grids that cover a domain and overlap where they meet. Overlapping grids provide an effective approach for developing efficient and accurate approximations for complex, possibly moving geometry. Topics to be addressed include the reactive Euler equations, the incompressible Navier-Stokes equations and elliptic equations solved with a multigrid algorithm. Recent developments coupling moving grids and adaptive mesh refinement and preliminary parallel results will also be presented.

  10. Finite size fluid particle in nonuniform moving grid

    International Nuclear Information System (INIS)

    The particle-in-cell (PIC) method, which is known as mixed Eulerian-Lagrangian scheme, has been applied successfully to solve a wide variety of problems in which the fluid distortion is large. In this paper, a new type of the PIC method is presented. Area-weighting technique and a nonuniform-spacing, moving grid were employed for the suppression of nonphysical fluctuation and for the description of large density variation with few particles, respectively. The reduction of numerical viscosity is discussed. In a basic scheme, the equations for one compressible fluid were used. In the present approach to the PIC method, a particle has the memories for its own mass, position and internal energy, but momentum is attached to the particle only when it moves, in order to evade the multistreaming problem. An essential point is that a particle preserves the memory of the cell boundary lines when it moves. As the examples, one-dimensional adiabatic expansion process and the Rayleigh-Taylor instability were analyzed. The results showed that the new PIC method is useful for the description of large density variation with few particles as well as for the cases known to be powerful in Harlow's PIC method. Nonphysical noise, numerical thermal diffusion and viscosity were successfully reduced. A nonuniformly-spacing, moving grid system can be used for the local fine resolution of processes. (Kato, T.)

  11. Jets generated by a sphere moving vertically in stratified fluids

    Science.gov (United States)

    Hanazaki, Hideshi; Okino, Shinya; Nakamura, Shota; Akiyama, Shinsaku

    2013-11-01

    Unsteady development of buoyant jets generated by a sphere moving vertically at constant speeds in stratified fluids is investigated. Initially, the sphere simply drags light upper fluids or isopycnal surfaces as it goes down, as long as the molecular diffusion of density is negligible. In the succeeding period, molecular diffusion of density in the boundary layer on the sphere surface becomes increasingly significant, especially in the lower hemisphere. Then, the density is no longer conserved and a vertical jet starts from the rear/upper stagnation point of the sphere, since the fluid particle of altered but small density tends to go back to its original height. Strength and radius of those jets depend significantly on stratification (Froude number), as well as the Reynolds number and the Schmidt number. These mechanisms are investigated by numerical simulations and measurements by laser induced fluorescence (LIF).

  12. 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%.

  13. Biological Phosphorus Removal in a Moving Bed Biofilm Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Helness, Herman

    2007-09-15

    The scope of this study was to investigate use of the moving bed biofilm reactor (MBBR) process for biological phosphorus removal. The goal has been to describe the operating conditions required for biological phosphorus and nitrogen removal in a MBBR operated as a sequencing batch reactor (SBR), and determine dimensioning criteria for such a process

  14. Moving Quark in a General Fluid Dynamical Flow

    CERN Document Server

    Abbasi, Navid

    2013-01-01

    We determine the most general form of the covariant drag force exerted on a quark moving through a fluid dynamical flow. Up to first order in derivative expansion, our general formula requires the specification of seven coefficient functions. We use the perturbative method introduced in arXiv:1202.2707 and find all these coefficients in the hydrodynamic regime of a $\\mathcal{N}=4$ SYM plasma. Having this general formula, we obtain the rate of the energy and momentum loss of a quark, namely the drag force, in a general flow. This result makes it possible to perturbatively study the motion of heavy quarks moving through the Bjorken flow up to first order in derivative expansion.

  15. Analysis of Acoustic Wave Propagation in a Thin Moving Fluid

    OpenAIRE

    Joly, Patrick; Weder, Ricardo

    2009-01-01

    We study the propagation of acoustic waves in a fluid that is contained in a thin two-dimensional tube, and that it is moving with a velocity profile that only depends on the transversal coordinate of the tube. The governing equations are the Galbrun equations, or, equivalently, the linearized Euler equations. We analyze the approximate model that was recently derived by Bonnet-Bendhia, Durufl\\'e and Joly to describe the propagation of the acoustic waves in the limit when the width of the tub...

  16. Lagrangian modelling of fluid sloshing in moving tanks

    OpenAIRE

    Buldakov, E.

    2014-01-01

    The paper presents general Lagrangian formulation for sloshing of inviscid fluid in 2D tanks under vertical and horizontal excitation. In the case of a rectangular tank a third-order asymptotic solution for resonant sloshing with a dominating mode is derived using the recursive technique introduced by Buldakov et al. (2006). The problem is also solved numerically using a fully nonlinear finite difference approximation. Both the Lagrangian recursive asymptotic model and the Lagrangian fully no...

  17. Moving forward responsibly: Oversight for the nanotechnology-biology interface

    International Nuclear Information System (INIS)

    Challenges and opportunities for appropriate oversight of nanotechnology applied to or derived from biological systems (nano-bio interface) were discussed in a public workshop and dialog hosted by the Center for Science, Technology, and Public Policy of the University of Minnesota on September 15, 2005. This paper discusses the themes that emerged from the workshop, including the importance of analyzing potential gaps in current regulatory systems; deciding upon the general approach taken toward regulation; employing non-regulatory mechanisms for governance; making risk and other studies transparent and available to the public; bolstering mechanisms for public participation in risk analysis; creating more opportunities for meaningful discussion of the social and ethical dimensions of the nano-bio interface; increasing funds for implications and problem-solving research in this area; and having independent and reliable sources for communication. The workshop was successful in identifying ways of moving forward responsibly so that ultimately nanotechnology and its products can succeed in developers', researchers', regulators', and the public's eyes

  18. Unsteady Boundary-Layer Flow over Jerked Plate Moving in a Free Stream of Viscoelastic Fluid

    Directory of Open Access Journals (Sweden)

    Sufian Munawar

    2014-01-01

    Full Text Available This study aims to investigate the unsteady boundary-layer flow of a viscoelastic non-Newtonian fluid over a flat surface. The plate is suddenly jerked to move with uniform velocity in a uniform stream of non-Newtonian fluid. Purely analytic solution to governing nonlinear equation is obtained. The solution is highly accurate and valid for all values of the dimensionless time 0≤τ<∞. Flow properties of the viscoelastic fluid are discussed through graphs.

  19. A mathematics model investigation of ideal fluids in a pipeline of moving ending

    Institute of Scientific and Technical Information of China (English)

    CHEN Bin; YI Meng-lin

    2007-01-01

    A case of ideal fluid flow in a moving ending rigid constant diameter circular pipeline is investigated.A model of the pipeline was established based on distributed-parameter theory. The comparisons on a quotient module of output and input pressure of the moving ending model and neglected ending moving model are made on the frequency response. It is revealed that the moving ending of pipeline influences largely the quotient amplitude of output and input pressure, and the peak value of frequency resonance increases with the increase of pipeline's length.

  20. Radioimmunoassay of penicilloyl groups in biological fluids

    International Nuclear Information System (INIS)

    Penicilloyl-protein conjugates may be formed in man or animals after therapeutic treatment but cannot be detected by the classical microbiological assay methods used for penicillin. Allergies have been noted in consumers of products coming from animals treated with penicillin (milk particularly). Although these compounds present a risk to public health, they passed unnoticed through hygienic food inspection. Therefore a specific and sensitive method was devised for the assay of these derivatives in biological fluids where they can be present in trace amounts. An iodine-125 labelled conjugate has been prepared. Already usable for the detection of antipenicilloyl antibodies in sera of penicillin allergic patients, it has been used for the development of a radioimmunoassay of penicilloyl groups. Assay is done directly on milk, urine and serum without previous extraction and with a detection limit of a few ppb. It permits a rapid, specific and easy to handle determination in the sera of hospital patients as well as in the inspection of animal products at the slaughter house and at the dairy

  1. Biological Phosphorus Removal in a Moving Bed Biofilm Reactor

    OpenAIRE

    Helness, Herman

    2007-01-01

    Phosphorus (P) and nitrogen (N) removal from municipal wastewater is performed to prevent or reduce eutrophication in the receiving water.Both P and N can be removed physical/chemically as well as biologically. While biological processes have always dominated in N-removal, chemical P-removal is used in many cases. Biological P-removal using enhanced biological phosphorus removal (EBPR) is normally carried out in suspended culture (activated sludge) processes while biological N-removal (throug...

  2. Numerical Study of Thermal Boundary Layer on a Continuous Moving Surface in Power Law Fluids

    Institute of Scientific and Technical Information of China (English)

    Hao ZHANG; Xinxin ZHANG; Liancun ZHENG

    2007-01-01

    This paper investigates flow and heat transfer of power law fluids on a continuous moving surface. The temperature distribution is obtained numerically by considering the effect of the power law viscosity on thermal diffusivity and the characteristics of the flow and heat transfer are analyzed. The results show that the distribution of the thermal boundary layer depends not only on the velocity ratio parameter of the plate, but also on the power law index and Prandtl number of fluids.

  3. On the identifiability of a rigid body moving in a stationary viscous fluid

    International Nuclear Information System (INIS)

    This paper is devoted to a geometrical inverse problem associated with a fluid–structure system. More precisely, we consider the interaction between a moving rigid body and a viscous and incompressible fluid. Assuming a low Reynolds regime, the inertial forces can be neglected and, therefore, the fluid motion is modelled by the Stokes system. We first prove the well posedness of the corresponding system. Then we show an identifiability result: with one measure of the Cauchy forces of the fluid on one given part of the boundary and at some positive time, the shape of a convex body and its initial position are identified. (paper)

  4. Moving Towards Interpretable Mechanisms in Human Systems Biology

    OpenAIRE

    Thomas, Alex

    2015-01-01

    A detailed understanding of biomolecular mechanisms enables predictive modeling in biological systems. In the late 1990's, whole-genome sequencing and the development of various high-throughput technologies led to the emergence of systems biology, primarily in simple model organisms such as bacteria and yeast. Mechanisms between biological components and processes were cataloged and placed in mathematical frameworks to explain the role of genotype and environmental factors on phenotypes. Some...

  5. Biomedicines—Moving Biologic Agents into Approved Treatment Options

    Directory of Open Access Journals (Sweden)

    Kenneth Cornetta

    2013-03-01

    Full Text Available The development of biologic agents for therapeutic purposes, or biomedicines, has seen an active area of research both at the bench and in clinical trials. There is mounting evidence that biologic products can provide effective therapy for diseases that have been unresponsive to traditional pharmacologic approaches. Monoclonal antibody therapy for cancer and rheumatologic diseases has become a well accepted part of disease treatment plans. Gene therapy products have been approved in China and Europe. Bioengineering of new agents capitalizing on microRNA biology, nanoparticle technology, stem cell biology, and an increasing understanding of immunology predict a rich future for product development. [...

  6. A rapid and simple cannulation technique for repeated sampling of cerebrospinal fluid in freely moving rats

    NARCIS (Netherlands)

    Bouman, H.J.; Wimersma Greidanus, T.B. van

    1979-01-01

    A cannulation technique for frequent sampling of cerebrospinal fluid (CSF) in unanaesthetized freely moving rats is described. A permanent stainless steel cannula, constructed in such a way that no loss of CSF occurs, is placed into the rat's cisterna magna and fixed to the skull by anchoring screws

  7. Researchers move closer to understanding chaotic motion of a solid body in a fluid

    OpenAIRE

    Nystrom, Lynn A.

    2010-01-01

    In a paper appearing in the Feb. 24 issue of the "Proceedings of the Royal Society of London A," Virginia Tech Engineering Science and Mechanics Professor Hassan Aref, and his colleague Johan Roenby at the Technical University of Denmark shed new light on the chaotic motion of a solid body moving through a fluid.

  8. Computational Fluid Dynamic Approach for Biological System Modeling

    OpenAIRE

    Huang, Weidong; Wu, Chundu; Xiao, Bingjia; Xia, Weidong

    2005-01-01

    Various biological system models have been proposed in systems biology, which are based on the complex biological reactions kinetic of various components. These models are not practical because we lack of kinetic information. In this paper, it is found that the enzymatic reaction and multi-order reaction rate is often controlled by the transport of the reactants in biological systems. A Computational Fluid Dynamic (CFD) approach, which is based on transport of the components and kinetics of b...

  9. Ants as Fluids: Physics-Inspired Biology

    CERN Document Server

    Streiff, Micah; Shinotsuka, Sho; Alexeev, Alex; Hu, David

    2010-01-01

    Fire ants use their claws to grip diverse surfaces, including each other. As a result of their mutual adhesion and large numbers, ant colonies flow like inanimate fluids. In this sequence of films, we demonstrate how ants behave similarly to the spreading of drops, the capillary rise of menisci, and gravity-driven flow down a wall. By emulating the flow of fluids, ant colonies can remain united under stressful conditions.

  10. Methods for analysis of fluoroquinolones in biological fluids

    Science.gov (United States)

    Methods for analysis of 10 selected fluoroquinolone antibiotics in biological fluids are reviewed. Approaches for sample preparation, detection methods, limits of detection and quantitation and recovery information are provided for both single analyte and multi-analyte fluoroquinolone methods....

  11. High order methods for incompressible fluid flow: Application to moving boundary problems

    Energy Technology Data Exchange (ETDEWEB)

    Bjoentegaard, Tormod

    2008-04-15

    Fluid flows with moving boundaries are encountered in a large number of real life situations, with two such types being fluid-structure interaction and free-surface flows. Fluid-structure phenomena are for instance apparent in many hydrodynamic applications; wave effects on offshore structures, sloshing and fluid induced vibrations, and aeroelasticity; flutter and dynamic response. Free-surface flows can be considered as a special case of a fluid-fluid interaction where one of the fluids are practically inviscid, such as air. This type of flows arise in many disciplines such as marine hydrodynamics, chemical engineering, material processing, and geophysics. The driving forces for free-surface flows may be of large scale such as gravity or inertial forces, or forces due to surface tension which operate on a much smaller scale. Free-surface flows with surface tension as a driving mechanism include the flow of bubbles and droplets, and the evolution of capillary waves. In this work we consider incompressible fluid flow, which are governed by the incompressible Navier-Stokes equations. There are several challenges when simulating moving boundary problems numerically, and these include - Spatial discretization - Temporal discretization - Imposition of boundary conditions - Solution strategy for the linear equations. These are some of the issues which will be addressed in this introduction. We will first formulate the problem in the arbitrary Lagrangian-Eulerian framework, and introduce the weak formulation of the problem. Next, we discuss the spatial and temporal discretization before we move to the imposition of surface tension boundary conditions. In the final section we discuss the solution of the resulting linear system of equations. (Author). refs., figs., tabs

  12. A Biological Hierarchical Model Based Underwater Moving Object Detection

    OpenAIRE

    Jie Shen; Tanghuai Fan; Min Tang; Qian Zhang; Zhen Sun; Fengchen Huang

    2014-01-01

    Underwater moving object detection is the key for many underwater computer vision tasks, such as object recognizing, locating, and tracking. Considering the super ability in visual sensing of the underwater habitats, the visual mechanism of aquatic animals is generally regarded as the cue for establishing bionic models which are more adaptive to the underwater environments. However, the low accuracy rate and the absence of the prior knowledge learning limit their adaptation in underwater appl...

  13. Transverse vibration of an axially moving slender fiber of viscoelastic fluid in bubbfil spinning and stuffer box crimping

    OpenAIRE

    Huang Jian-Xin; Song Min-Feng; Li Zhang; Liu Peng; Chen Rou-Xi; He Ji-Huan; Wang Shu-Qiang

    2015-01-01

    Transverse vibration of an axially moving slender fiber of viscoelastic fluid is studied. The governing equations are derived under the assumptions of onedimensional steady and incompressible flow and linear Euler-Bernoulli bar. Effect of the moving velocity of the liquid fiber on natural frequencies is discussed, and the critical velocities of moving fibers are derived, below which transverse vibration is exponentially damped.

  14. Wave drag of rapidly and horizontally moving Rankine ovoid in uniformly stratified fluid

    Institute of Scientific and Technical Information of China (English)

    Zhaoting Xu; Qun Li; V. A. Gorodtsov

    2008-01-01

    A theory on the wave drag as the Rankine ovoids moving horizontally, uniformly and rapidly in uniformly vertical stratified fluid (or ocean) is presented. A mass source resulting from the theory in a uniform fluid is used to model a hydrodynamic interaction between the Rankine ovoid and stratification. Theoretical results show that there exists an asymptotic state of the drag in supercritical regimes where internal Froude numbers are large. When the Rankine ovoid reduces to a sphere, the result we obtained is in good agreement with the previous theoretical and experimental results. An experiment on the elongated Rankine ovoid is also carried out to validate the theoretical results.

  15. Volume-averaged macroscopic equation for fluid flow in moving porous media

    CERN Document Server

    Wang, Liang; Guo, Zhaoli; Mi, Jianchun

    2014-01-01

    Darcy's law and the Brinkman equation are two main models used for creeping fluid flows inside moving permeable particles. For these two models, the time derivative and the nonlinear convective terms of fluid velocity are neglected in the momentum equation. In this paper, a new momentum equation including these two terms are rigorously derived from the pore-scale microscopic equations by the volume-averaging method, which can reduces to Darcy's law and the Brinkman equation under creeping flow conditions. Using the lattice Boltzmann equation method, the macroscopic equations are solved for the problem of a porous circular cylinder moving along the centerline of a channel. Galilean invariance of the equations are investigated both with the intrinsic phase averaged velocity and the phase averaged velocity. The results demonstrate that the commonly used phase averaged velocity cannot serve as the superficial velocity, while the intrinsic phase averaged velocity should be chosen for porous particulate systems.

  16. Moving finite elements: A continuously adaptive method for computational fluid dynamics

    International Nuclear Information System (INIS)

    Moving Finite Elements (MFE), a recently developed method for computational fluid dynamics, promises major advances in the ability of computers to model the complex behavior of liquids, gases, and plasmas. Applications of computational fluid dynamics occur in a wide range of scientifically and technologically important fields. Examples include meteorology, oceanography, global climate modeling, magnetic and inertial fusion energy research, semiconductor fabrication, biophysics, automobile and aircraft design, industrial fluid processing, chemical engineering, and combustion research. The improvements made possible by the new method could thus have substantial economic impact. Moving Finite Elements is a moving node adaptive grid method which has a tendency to pack the grid finely in regions where it is most needed at each time and to leave it coarse elsewhere. It does so in a manner which is simple and automatic, and does not require a large amount of human ingenuity to apply it to each particular problem. At the same time, it often allows the time step to be large enough to advance a moving shock by many shock thicknesses in a single time step, moving the grid smoothly with the solution and minimizing the number of time steps required for the whole problem. For 2D problems (two spatial variables) the grid is composed of irregularly shaped and irregularly connected triangles which are very flexible in their ability to adapt to the evolving solution. While other adaptive grid methods have been developed which share some of these desirable properties, this is the only method which combines them all. In many cases, the method can save orders of magnitude of computing time, equivalent to several generations of advancing computer hardware

  17. MHD Stagnation Flow of a Newtonian Fluid towards a Uniformly Heated and Moving Vertical Plate

    Directory of Open Access Journals (Sweden)

    Mehmet Şirin Demir

    2016-01-01

    Full Text Available Stagnation flow of an electrically conducting incompressible viscous fluid towards a moving vertical plate in the presence of a constant magnetic field is investigated. By using the appropriate transformations for the velocity components and temperature, the partial differential equations governing flow and heat transfer are reduced to a set of nonlinear ordinary differential equations. These equations are solved approximately using a numerical technique for the following two problems: (i two-dimensional stagnation-point flow on a moving vertical plate, (ii axisymmetric stagnation-point flow on a moving vertical plate. The effects of non-dimensional parameters on the velocity components, wall shear stresses, temperature and heat transfer are examined carefully.

  18. A Biological Hierarchical Model Based Underwater Moving Object Detection

    Directory of Open Access Journals (Sweden)

    Jie Shen

    2014-01-01

    Full Text Available Underwater moving object detection is the key for many underwater computer vision tasks, such as object recognizing, locating, and tracking. Considering the super ability in visual sensing of the underwater habitats, the visual mechanism of aquatic animals is generally regarded as the cue for establishing bionic models which are more adaptive to the underwater environments. However, the low accuracy rate and the absence of the prior knowledge learning limit their adaptation in underwater applications. Aiming to solve the problems originated from the inhomogeneous lumination and the unstable background, the mechanism of the visual information sensing and processing pattern from the eye of frogs are imitated to produce a hierarchical background model for detecting underwater objects. Firstly, the image is segmented into several subblocks. The intensity information is extracted for establishing background model which could roughly identify the object and the background regions. The texture feature of each pixel in the rough object region is further analyzed to generate the object contour precisely. Experimental results demonstrate that the proposed method gives a better performance. Compared to the traditional Gaussian background model, the completeness of the object detection is 97.92% with only 0.94% of the background region that is included in the detection results.

  19. A biological hierarchical model based underwater moving object detection.

    Science.gov (United States)

    Shen, Jie; Fan, Tanghuai; Tang, Min; Zhang, Qian; Sun, Zhen; Huang, Fengchen

    2014-01-01

    Underwater moving object detection is the key for many underwater computer vision tasks, such as object recognizing, locating, and tracking. Considering the super ability in visual sensing of the underwater habitats, the visual mechanism of aquatic animals is generally regarded as the cue for establishing bionic models which are more adaptive to the underwater environments. However, the low accuracy rate and the absence of the prior knowledge learning limit their adaptation in underwater applications. Aiming to solve the problems originated from the inhomogeneous lumination and the unstable background, the mechanism of the visual information sensing and processing pattern from the eye of frogs are imitated to produce a hierarchical background model for detecting underwater objects. Firstly, the image is segmented into several subblocks. The intensity information is extracted for establishing background model which could roughly identify the object and the background regions. The texture feature of each pixel in the rough object region is further analyzed to generate the object contour precisely. Experimental results demonstrate that the proposed method gives a better performance. Compared to the traditional Gaussian background model, the completeness of the object detection is 97.92% with only 0.94% of the background region that is included in the detection results. PMID:25140194

  20. Phase transitions in fluids and biological systems

    Science.gov (United States)

    Sipos, Maksim

    In this thesis, I consider systems from two seemingly different fields: fluid dynamics and microbial ecology. In these systems, the unifying features are the existences of global non-equilibrium steady states. I consider generic and statistical models for transitions between these global states, and I relate the model results with experimental data. A theme of this thesis is that these rather simple, minimal models are able to capture a lot of functional detail about complex dynamical systems. In Part I, I consider the transition between laminar and turbulent flow. I find that quantitative and qualitative features of pipe flow experiments, the superexponential lifetime and the splitting of turbulent puffs, and the growth rate of turbulent slugs, can all be explained by a coarse-grained, phenomenological model in the directed percolation universality class. To relate this critical phenomena approach closer to the fluid dynamics, I consider the transition to turbulence in the Burgers equation, a simplified model for Navier-Stokes equations. Via a transformation to a model of directed polymers in a random medium, I find that the transition to Burgers turbulence may also be in the directed percolation universality class. This evidence implies that the turbulent-to-laminar transition is statistical in nature and does not depend on details of the Navier-Stokes equations describing the fluid flow. In Part II, I consider the disparate subject of microbial ecology where the complex interactions within microbial ecosystems produce observable patterns in microbe abundance, diversity and genotype. In order to be able to study these patterns, I develop a bioinformatics pipeline to multiply align and quickly cluster large microbial metagenomics datasets. I also develop a novel metric that quantifies the degree of interactions underlying the assembly of a microbial ecosystem, particularly the transition between neutral (random) and niche (deterministic) assembly. I apply this

  1. 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...

  2. Moving hydrocarbons through portions of tar sands formations with a fluid

    Science.gov (United States)

    Stegemeier, George Leo; Mudunuri, Ramesh Raju; Vinegar, Harold J.; Karanikas, John Michael; Jaiswal, Namit; Mo, Weijian

    2010-05-18

    A method for treating a tar sands formation is disclosed. The method includes heating a first portion of a hydrocarbon layer in the formation from one or more heaters located in the first portion. The heat is controlled to increase a fluid injectivity of the first portion. A drive fluid and/or an oxidizing fluid is injected and/or created in the first portion to cause at least some hydrocarbons to move from a second portion of the hydrocarbon layer to a third portion of the hydrocarbon layer. The second portion is between the first portion and the third portion. The first, second, and third portions are horizontally displaced from each other. The third portion is heated from one or more heaters located in the third portion. Hydrocarbons are produced from the third portion of the formation. The hydrocarbons include at least some hydrocarbons from the second portion of the formation.

  3. Amino acid analysis in biological fluids by GC-MS

    OpenAIRE

    Kaspar, Hannelore

    2009-01-01

    Amino acids are intermediates in cellular metabolism and their quantitative analysis plays an important role in disease diagnostics. A gas chromatography-mass spectrometry (GC-MS) based method was developed for the quantitative analysis of free amino acids as their propyl chloroformate derivatives in biological fluids. Derivatization with propyl chloroformate could be carried out directly in the biological samples without prior protein precipitation or solid-phase extraction of the amino acid...

  4. Internal resonance of an axially moving unidirectional plate partially immersed in fluid under foundation displacement excitation

    Science.gov (United States)

    Li, Hong Ying; Li, Jian; Liu, Yong Jun

    2015-12-01

    This paper studies characteristics of 1:3 internal resonances and its bifurcations for an axially moving unidirectional plate partially immersed in a fluid under foundation displacement excitation. The fluid is assumed to be inviscid and incompressible. Based on Von Kármán large deflection equations of thin plates, and consider the influences of axial movement of the plate, axial tension, fluid-structure interaction and foundation displacement, nonlinear vibration equations of an axially moving plate are established. By applying the Galerkin technique, the vibration equations are discretized, and thus achieve nonlinear differential equations on mode coordinates. Due to the influence of foundation displacement, there are more than two excitation items in the mode equations. Moreover, excitation amplitude is not a constant value, but a function of excitation frequency. Adopting numerical method and approximate analysis method, the equations are solved, moreover frequency-response curves and time histories under internal resonance system are also obtained, the stability of periodic solution is also discussed. Global bifurcation phenomenon of averaging equations is studied for 1:3 internal resonance system. Changing course of periodic solution of the system and its complex nonlinear dynamic characteristics are revealed through bifurcation diagrams and phase trajectory diagrams.

  5. Deformation of a partially engulfed compound drop slowly moving in an immiscible viscous fluid

    Science.gov (United States)

    Rosenfeld, L.; Lavrenteva, O. M.; Spivak, R.; Nir, A.

    2011-02-01

    Compound drops are comprised of two or more immiscible phases, one of which entirely or partially engulfs the others. In this work, we consider a partially engulfed compound drop comprised of two immiscible incompressible fluids, dispersed in an isothermal liquid, and that moved under the action of gravity and buoyancy. The contact angles between the three phases are determined by three interfacial tensions associated with the different fluids comprising the compound drop. The surfaces deform as the drop moves through the ambient fluid. If the capillary number is small (Ca≪1), corrections to the shapes of the undeformable case (Ca=0) are constructed, making use of a perturbation technique. We report on stationary drops' deformation for a variety of the physical parameters involved, such as volume ratio and surface tension of each interface, which determine the unperturbed configuration and the distribution of density between the two phases of the drop. Several examples of various transient behaviors of highly deformable compound drops are computed using FLUENT software and are presented as well.

  6. Boundary Layer Flow and Heat Transfer with Variable Fluid Properties on a Moving Flat Plate in a Parallel Free Stream

    Directory of Open Access Journals (Sweden)

    Norfifah Bachok

    2012-01-01

    Full Text Available The steady boundary layer flow and heat transfer of a viscous fluid on a moving flat plate in a parallel free stream with variable fluid properties are studied. Two special cases, namely, constant fluid properties and variable fluid viscosity, are considered. The transformed boundary layer equations are solved numerically by a finite-difference scheme known as Keller-box method. Numerical results for the flow and the thermal fields for both cases are obtained for various values of the free stream parameter and the Prandtl number. It is found that dual solutions exist for both cases when the fluid and the plate move in the opposite directions. Moreover, fluid with constant properties shows drag reduction characteristics compared to fluid with variable viscosity.

  7. Green Algae as Model Organisms for Biological Fluid Dynamics

    Science.gov (United States)

    Goldstein, Raymond E.

    2015-01-01

    In the past decade, the volvocine green algae, spanning from the unicellular Chlamydomonas to multicellular Volvox, have emerged as model organisms for a number of problems in biological fluid dynamics. These include flagellar propulsion, nutrient uptake by swimming organisms, hydrodynamic interactions mediated by walls, collective dynamics and transport within suspensions of microswimmers, the mechanism of phototaxis, and the stochastic dynamics of flagellar synchronization. Green algae are well suited to the study of such problems because of their range of sizes (from 10 μm to several millimeters), their geometric regularity, the ease with which they can be cultured, and the availability of many mutants that allow for connections between molecular details and organism-level behavior. This review summarizes these recent developments and highlights promising future directions in the study of biological fluid dynamics, especially in the context of evolutionary biology, that can take advantage of these remarkable organisms.

  8. Remarks on Hierarchic Control for a Linearized Micropolar Fluids System in Moving Domains

    Energy Technology Data Exchange (ETDEWEB)

    Jesus, Isaías Pereira de, E-mail: isaias@ufpi.edu.br [Universidade Federal do Piauí, Dpto. Matemática (Brazil)

    2015-12-15

    We study a Stackelberg strategy subject to the evolutionary linearized micropolar fluids equations in domains with moving boundaries, considering a Nash multi-objective equilibrium (non necessarily cooperative) for the “follower players” (as is called in the economy field) and an optimal problem for the leader player with approximate controllability objective. We will obtain the following main results: the existence and uniqueness of Nash equilibrium and its characterization, the approximate controllability of the linearized micropolar system with respect to the leader control and the existence and uniqueness of the Stackelberg–Nash problem, where the optimality system for the leader is given.

  9. Transverse vibration of an axially moving slender fiber of viscoelastic fluid in bubbfil spinning and stuffer box crimping

    Directory of Open Access Journals (Sweden)

    Huang Jian-Xin

    2015-01-01

    Full Text Available Transverse vibration of an axially moving slender fiber of viscoelastic fluid is studied. The governing equations are derived under the assumptions of onedimensional steady and incompressible flow and linear Euler-Bernoulli bar. Effect of the moving velocity of the liquid fiber on natural frequencies is discussed, and the critical velocities of moving fibers are derived, below which transverse vibration is exponentially damped.

  10. Fluid extraction-biological degradation of organic wastes

    International Nuclear Information System (INIS)

    The Institute of Gas Technology (IGT) Fluid Extraction-Biological Degradation (FEBD) Process extracts hydrocarbon contaminants from soil and then biologically degrades the pollutants in aerobic bioreactors. The FEBD process has the potential to be an environmentally benign means of safely and economically degrading pollutants by overcoming bioavailability limitations of the pollutants in soil. The process consists of three stages; extraction, separation, and biodegradation. Contaminants are first removed from the soil by solubilization in supercritical carbondioxide in an above-ground extraction vessel. The hydrocarbon contaminants are then collected in a separation solvent, and clean CO2 is recycled to the extraction stage. Separation solvent containing the organic wastes is sent to the biodegradation stage where the wastes are converted to CO2, water, and biomass. All stages of the FEBD process have been successfully demonstrated. The extraction stage of the FEBD process relies on the unique properties of supercritical fluids (SCF) to remove organic contaminants from soil. An SCF is a compound at conditions exceeding its critical temperature and pressure. Fluids in the supercritical range have viscosities and diffusivities between liquids and gases with densities close to those of liquids. Supercritical fluids have the solution characteristics of liquids with better mass transfer capabilities. Extraction and separation are easily controlled because changes in the pressure (density) of an SCF can be used to change the solvation ability of the fluid

  11. Fluid dynamics of moving fish in a two-dimensional multiparticle collision dynamics model.

    Science.gov (United States)

    Reid, Daniel A P; Hildenbrandt, H; Padding, J T; Hemelrijk, C K

    2012-02-01

    The fluid dynamics of animal locomotion, such as that of an undulating fish, are of great interest to both biologists and engineers. However, experimentally studying these fluid dynamics is difficult and time consuming. Model studies can be of great help because of their simpler and more detailed analysis. Their insights may guide empirical work. Particularly the recently introduced multiparticle collision dynamics method may be suitable for the study of moving organisms because it is computationally fast, simple to implement, and has a continuous representation of space. As regards the study of hydrodynamics of moving organisms, the method has only been applied at low Reynolds numbers (below 120) for soft, permeable bodies, and static fishlike shapes. In the present paper we use it to study the hydrodynamics of an undulating fish at Reynolds numbers 1100-1500, after confirming its performance for a moving insect wing at Reynolds number 75. We measure (1) drag, thrust, and lift forces, (2) swimming efficiency and spatial structure of the wake, and (3) distribution of forces along the fish body. We confirm the resemblance between the simulated undulating fish and empirical data. In contrast to theoretical predictions, our model shows that for steadily undulating fish, thrust is produced by the rear 2/3 of the body and that the slip ratio U/V (with U the forward swimming speed and V the rearward speed of the body wave) correlates negatively (instead of positively) with the actual Froude efficiency of swimming. Besides, we show that the common practice of modeling individuals while constraining their sideways acceleration causes them to resemble unconstrained fish with a higher tailbeat frequency. PMID:22463238

  12. A quadtree adaptive method for simulating fluid flows with moving interfaces

    International Nuclear Information System (INIS)

    In this paper, a computational method for solving fluid flow problems with moving interfaces is presented. Herein, adaptive quadtree grids are used coupled with the CICSAM [O. Ubbink, Numerical prediction of two fluid systems with sharp interfaces, PhD Thesis, Imperial College of Science, Technology and Medicine, London, 1997] free surface capturing volume of fluid (VoF) method and PLIC reconstruction to interpolate the volume fraction field during refinement and derefinement processes. The combination of high resolution adaptive hierarchical remeshing and CICSAM interface advection is shown to overcome the problems of interface smearing and high CPU intensivity inherent in most VoF schemes. The result is a combination of free surface tracking and free surface capturing in that the interface is effectively tracked by the adapting refinements in the quadtree grid. In this way, a sharp interface is achieved and the advantages of both free surface tracking and capturing are combined. The new method is applied to interface advection examples in translating, rotating and shearing flow fields, and the benefits of using adapting quadtree grids demonstrated

  13. Unsteady MHD convection and mass transfer flow of micropolar fluids past a vertical permeable moving plate with heat absorption

    International Nuclear Information System (INIS)

    By the use of the theory of micropolar fluids due to Eringen, perturbation method is presented to study an unsteady MHD convection and mass transfer flow of micropolar fluids past a vertical permeable moving plate with heat absorption. The plate moves with a constant velocity in the direction of fluid flow, while the free stream velocity follows an exponentially increasing or decreasing small perturbation law. Approximate solutions of the coupled nonlinear governing equations are obtained for different values of microrotation and magnetic parameters. Numerical calculations are carried out for the various parameters entering into the problem. The results of velocity, angular velocity, temperature and concentration profiles have been presented graphically for various values of the material parameters. The results indicate that the micropolar fluids display a reduction in drag as well as heat transfer rate when compared with Newtonian fluids. (author)

  14. Analytical Problems in Exposing Amperometric Enzyme Biosensors to Biological Fluids

    Directory of Open Access Journals (Sweden)

    Gaia Rocchitta

    2016-05-01

    Full Text Available Enzyme-based chemical biosensors are based on biological recognition. In order to operate, the enzymes must be available to catalyze a specific biochemical reaction and be stable under the normal operating conditions of the biosensor. Design of biosensors is based on knowledge about the target analyte, as well as the complexity of the matrix in which the analyte has to be quantified. This article reviews the problems resulting from the interaction of enzyme-based amperometric biosensors with complex biological matrices containing the target analyte(s. One of the most challenging disadvantages of amperometric enzyme-based biosensor detection is signal reduction from fouling agents and interference from chemicals present in the sample matrix. This article, therefore, investigates the principles of functioning of enzymatic biosensors, their analytical performance over time and the strategies used to optimize their performance. Moreover, the composition of biological fluids as a function of their interaction with biosensing will be presented.

  15. Infrared light scattering in biological tissues and fluids

    Science.gov (United States)

    Thomas, Gordon A.; Koo, Tae-Woong; Dasari, Ramachandra R.; Feld, Michael S.

    2001-03-01

    We have studied the elastic and Raman scattering from whole blood, blood serum and related biological fluids and tissues. The motivation of this work is to determine the composition and elastic scattering properties with a non-invasive, optical method. An example of the possible applications is the determination of the glucose concentration and its variations in a way that would be clinically effective for patients with diabetes. We have imaged the elastically scattered light and determined the scattering parameters in order to assess appropriate geometries for efficient collection of the Raman scattering. Using the Raman apectra we have determined the concentration of glucose and the other analytes under laboratory conditions.

  16. Biological and biomedical aspects of magnetic fluid technology

    Science.gov (United States)

    Roath, S.

    1993-04-01

    Magnetic fluid technology has undergone study and development in its biological and biomedical aspects, principally in image enhancement and in the use of a variety of Separation techniques in the purification of biological materials or in the identification of very small amounts of organisms, cells, or genomic material. Many of these processes are already applied to small scale laboratory processing or manufacturing. A variety of magnetic materials are used; no standard technique has yet been consolidated but efficiency of separation especially is rapidly increasing. Clinical applications may be related both to diagnosis in areas of low level infection or contamination and also in ex-vivo processing of materials such as human bone marrow or peripheral blood where specific cell populations can be extracted. This may be a valuable tool in human bone marrow processing and in the coming field of gene transfer technology, as well as in the purification of genomic material.

  17. MHD accretion of a perfect fluid with an ultrahard equation of state onto a moving Schwarzschild black hole

    Science.gov (United States)

    Chernov, S. V.

    2016-06-01

    The full version of the magnetohydrodynamical (MHD) theory of accretion of a perfect fluid with an ultrahard equation of state, p = μ ~ ρ 2 (where p is the pressure, μ the total energy density, and ρ the fluid density), onto a moving Schwarzschild black hole is considered. Exact and approximate analytical solutions have been found. It is shown that smooth continuous solutions exist only in the case when a single critical sound surface is formed.

  18. WAVES GENERATED BY A 3D MOVING BODY IN A TWO-LAYER FLUID OF FINITE DEPTH

    Institute of Scientific and Technical Information of China (English)

    ZHU Wei; YOU Yun-xiang; MIAO Guo-ping; ZHAO Feng; ZHANG Jun

    2005-01-01

    This paper is concerned with the waves generated by a 3-D body advancing beneath the free surface with constant speed in a two-layer fluid of finite depth. By applying Green's theorem, a layered integral equation system based on the Rankine source for the perturbed velocity potential generated by the moving body was derived with the potential flow theory. A four-node isoparametric element method was used to treat with the solution of the layered integral equation system. The surface and interface waves generated by a moving ball were calculated numerically. The results were compared with the analytical results for a moving source with constant velocity.

  19. Fluid Mechanics of Biological Surfaces and their Technological Application

    Science.gov (United States)

    Bechert, D. W.; Bruse, M.; Hage, W.; Meyer, R.

    A survey is given on fluid-dynamic effects caused by the structure and properties of biological surfaces. It is demonstrated that the results of investigations aiming at technological applications can also provide insights into biophysical phenomena. Techniques are described both for reducing wall shear stresses and for controlling boundary-layer separation. (a) Wall shear stress reduction was investigated experimentally for various riblet surfaces including a shark skin replica. The latter consists of 800 plastic model scales with compliant anchoring. Hairy surfaces are also considered, and surfaces in which the no-slip condition is modified. Self-cleaning surfaces such as that of lotus leaves represent an interesting option to avoid fluid-dynamic deterioration by the agglomeration of dirt. An example of technological implementation is discussed for riblets in long-range commercial aircraft. (b) Separation control is also an important issue in biology. After a few brief comments on vortex generators, the mechanism of separation control by bird feathers is described in detail. Self-activated movable flaps (=artificial bird feathers) represent a high-lift system enhancing the maximum lift of airfoils by about 20%. This is achieved without perceivable deleterious effects under cruise conditions. Finally, flight experiments on an aircraft with laminar wing and movable flaps are presented.

  20. A form of MHD universal equations of unsteady incompressible fluid flow with variable elctroconductivity on heated moving plate

    Directory of Open Access Journals (Sweden)

    Boričić Zoran

    2005-01-01

    Full Text Available This paper deals with laminar, unsteady flow of viscous, incompressible and electro conductive fluid caused by variable motion of flat plate. Fluid electro conductivity is variable. Velocity of the plate is time function. Plate moves in its own plane and in "still" fluid. Present external magnetic filed is perpendicular to the plate. Plate temperature is a function of longitudinal coordinate and time. Viscous dissipation, Joule heat, Hole and polarization effects are neglected. For obtaining of universal equations system general similarity method is used as well as impulse and energy equation of described problem.

  1. Dynamic behavior of a fluid conveying pipe subjected to a moving sprung mass - An FEM-state space approach

    International Nuclear Information System (INIS)

    In this paper, the dynamic behavior of a pipe conveying fluid, with a sprung mass moving on it is studied. The governing equation is obtained in the transverse and longitudinal directions based on the nonlinear Von-Karman sense, by which large displacements may be taken into account. The effect of rotary inertia is also considered. Using the Galerkin method with appropriate shape functions, the dynamic equations are discretized spatially. In developing the equations of motion, a nonsymmetric damping matrix emerges due to the Coriolis effect. As a result, the eigen-values (damped natural frequencies) and eigen-vectors (mode shapes) are to be obtained by the state-space method. First, only the effect of fluid flow is considered, and the results obtained show good agreement with analytical ones under different fluid velocities. After validation of the results, the effect of a moving sprung mass with damping is added to the system, and using the Newmark-β integration scheme, the response of the system is obtained for different moving load and fluid velocities. The results show that moving mass changes the dynamic properties of the system on the one hand, and acts as an external source of force in the vibration the system on the other.

  2. Newton's Investigation of the Resistance to Moving Bodies in Continuous Fluids and the Nature of "Frontier Science"

    Science.gov (United States)

    Gauld, Colin F.

    2010-01-01

    Newton's experiments into the resistance which fluids offer to moving bodies provide some insight into the way he related theory and experiment. His theory demonstrates a way of thought typical of 17th century physics and his experiments are simple enough to be replicated by present day students. Newton's investigations using pendulums were…

  3. Boundary layer flow on a moving surface in otherwise quiescent pseudo-plastic non-Newtonian fluids

    Institute of Scientific and Technical Information of China (English)

    Liancun Zheng; Liu Ting; Xinxin Zhang

    2008-01-01

    A theoretical analysis for the boundary layer flow over a continuous moving surface in an otherwise quiescent pseudo-plastic non-Newtonian fluid medium was presented. The types of potential flows necessary for similar solutions to the boundary layer equations were determined and the solutions were numerically presented for different values of power law exponent.

  4. Dynamic behavior of a fluid conveying pipe subjected to a moving sprung mass - An FEM-state space approach

    Energy Technology Data Exchange (ETDEWEB)

    Sadeghi, Morteza H. [Mechanical Engineering Department, University of Tabriz, Tabriz 516 66 (Iran, Islamic Republic of); Karimi-Dona, Mohammad H., E-mail: mkarimidona@yahoo.com [Mechanical Engineering Department, University of Tabriz, Tabriz 516 66 (Iran, Islamic Republic of)

    2011-04-15

    In this paper, the dynamic behavior of a pipe conveying fluid, with a sprung mass moving on it is studied. The governing equation is obtained in the transverse and longitudinal directions based on the nonlinear Von-Karman sense, by which large displacements may be taken into account. The effect of rotary inertia is also considered. Using the Galerkin method with appropriate shape functions, the dynamic equations are discretized spatially. In developing the equations of motion, a nonsymmetric damping matrix emerges due to the Coriolis effect. As a result, the eigen-values (damped natural frequencies) and eigen-vectors (mode shapes) are to be obtained by the state-space method. First, only the effect of fluid flow is considered, and the results obtained show good agreement with analytical ones under different fluid velocities. After validation of the results, the effect of a moving sprung mass with damping is added to the system, and using the Newmark-{beta} integration scheme, the response of the system is obtained for different moving load and fluid velocities. The results show that moving mass changes the dynamic properties of the system on the one hand, and acts as an external source of force in the vibration the system on the other.

  5. Irreversible Aspects of Continuum Mechanics and Transfer of Physical Characteristics in Moving Fluids : Symposia

    CERN Document Server

    Sedov, L

    1968-01-01

    At its meeting on April 23, 1965 in Paris the Bureau of IUTAM decided to have a Symposium on the Irreversible Aspects of Continaum Mechanics held in June 1966 in Vienna. In addition, a Symposium on the Transfer of Physical Characteristics in Moving Fluids which, orig­ inally, had been scheduled to take place in Stockholm was rescheduled to be held in Vienna immediately following the Symposium on the Irre­ versible Aspects of Continuum Mechanics. It was felt that the subjects of the two symposia were so closely related that participants should be given an opportunity to attend both. Both decisions were unanimously approved by the members of the General Assembly of IUTAM. Prof. H. PARKUS, Vienna, was appointed Chairman of the Symposium on the Irreversible Aspects, and Prof. L. I. SEDOV, Moscow, was appointed Chairman of the Symposium on the Transfer of Physical Characteristics, with Prof. P ARKUS being re­ sponsible for the local organization of both symposia. In accordance with the policy set forth by IUTAM...

  6. Momentum and heat transfer of an upper-convected Maxwell fluid over a moving surface with convective boundary conditions

    Energy Technology Data Exchange (ETDEWEB)

    Hayat, T. [Department of Mathematics, Quaid-i-Azam University 45320, Islamabad 44000 (Pakistan); Department of Mathematics, Faculty of Science, King Abdulaziz University, P. O. Box 80257, Jeddah 21589 (Saudi Arabia); Iqbal, Z., E-mail: zahidiqbal_qau@yahoo.com [Department of Mathematics, Quaid-i-Azam University 45320, Islamabad 44000 (Pakistan); Mustafa, M. [Research Centre for Modeling and Simulation, National University of Sciences and Technology, Sector H-12, Islamabad 44000 (Pakistan); Alsaedi, A. [Department of Mathematics, Faculty of Science, King Abdulaziz University, P. O. Box 80257, Jeddah 21589 (Saudi Arabia)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer Boundary layer flow of an upper-convected Maxwell (UCM) fluid over a moving surface. Black-Right-Pointing-Pointer Convective boundary conditions have been used. Black-Right-Pointing-Pointer Series solutions are obtained by homotopy analysis method (HAM). Black-Right-Pointing-Pointer Graphical results for various interesting parametric values. - Abstract: This study discusses the flow and heat transfer in an upper-convected Maxwell (UCM) fluid over a moving surface in the presence of a free stream velocity. The convective boundary conditions have been handled. Similarly transformations are invoked to convert the partial differential equations governing the steady flow of a Maxwell fluid into an ordinary differential system. This system is solved by a homotopic approach. The effects of influential parameters such as Deborah number ({beta}), Prandtl number (Pr), Eckert number (Ec), suction parameter (S) and ratio ({lambda}) have been thoroughly examined.

  7. From video to computation of biological fluid-structure interaction problems

    Science.gov (United States)

    Dillard, Seth I.; Buchholz, James H. J.; Udaykumar, H. S.

    2016-04-01

    This work deals with the techniques necessary to obtain a purely Eulerian procedure to conduct CFD simulations of biological systems with moving boundary flow phenomena. Eulerian approaches obviate difficulties associated with mesh generation to describe or fit flow meshes to body surfaces. The challenges associated with constructing embedded boundary information, body motions and applying boundary conditions on the moving bodies for flow computation are addressed in the work. The overall approach is applied to the study of a fluid-structure interaction problem, i.e., the hydrodynamics of swimming of an American eel, where the motion of the eel is derived from video imaging. It is shown that some first-blush approaches do not work, and therefore, careful consideration of appropriate techniques to connect moving images to flow simulations is necessary and forms the main contribution of the paper. A combination of level set-based active contour segmentation with optical flow and image morphing is shown to enable the image-to-computation process.

  8. A comprehensive screen for volatile organic compounds in biological fluids.

    Science.gov (United States)

    Sharp, M E

    2001-10-01

    A headspace gas chromatographic (GC) screen for common volatile organic compounds in biological fluids is reported. Common GC phases, DB-1 and DB-WAX, with split injection provide separation and identification of more than 40 compounds in a single 20-min run. In addition, this method easily accommodates quantitation. The screen detects commonly encountered volatile compounds at levels below 4 mg%. A control mixture, providing qualitative and semiquantitative information, is described. For comparison, elution of the volatiles on a specialty phase, DB-624, is reported. This method is an expansion and modification of a screen that had been used for more than 20 years. During its first year of use, the expanded screen has proven to be advantageous in routine forensic casework. PMID:11599614

  9. Fluid models and simulations of biological cell phenomena

    Science.gov (United States)

    Greenspan, H. P.

    1982-01-01

    The dynamics of coated droplets are examined within the context of biofluids. Of specific interest is the manner in which the shape of a droplet, the motion within it as well as that of aggregates of droplets can be controlled by the modulation of surface properties and the extent to which such fluid phenomena are an intrinsic part of cellular processes. From the standpoint of biology, an objective is to elucidate some of the general dynamical features that affect the disposition of an entire cell, cell colonies and tissues. Conventionally averaged field variables of continuum mechanics are used to describe the overall global effects which result from the myriad of small scale molecular interactions. An attempt is made to establish cause and effect relationships from correct dynamical laws of motion rather than by what may have been unnecessary invocation of metabolic or life processes. Several topics are discussed where there are strong analogies droplets and cells including: encapsulated droplets/cell membranes; droplet shape/cell shape; adhesion and spread of a droplet/cell motility and adhesion; and oams and multiphase flows/cell aggregates and tissues. Evidence is presented to show that certain concepts of continuum theory such as suface tension, surface free energy, contact angle, bending moments, etc. are relevant and applicable to the study of cell biology.

  10. Three-dimensional local ALE-FEM method for fluid flow in domains containing moving boundaries/objects interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Carrington, David Bradley [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Monayem, A. K. M. [Univ. of New Mexico, Albuquerque, NM (United States); Mazumder, H. [Univ. of New Mexico, Albuquerque, NM (United States); Heinrich, Juan C. [Univ. of New Mexico, Albuquerque, NM (United States)

    2015-03-05

    A three-dimensional finite element method for the numerical simulations of fluid flow in domains containing moving rigid objects or boundaries is developed. The method falls into the general category of Arbitrary Lagrangian Eulerian methods; it is based on a fixed mesh that is locally adapted in the immediate vicinity of the moving interfaces and reverts to its original shape once the moving interfaces go past the elements. The moving interfaces are defined by separate sets of marker points so that the global mesh is independent of interface movement and the possibility of mesh entanglement is eliminated. The results is a fully robust formulation capable of calculating on domains of complex geometry with moving boundaries or devises that can also have a complex geometry without danger of the mesh becoming unsuitable due to its continuous deformation thus eliminating the need for repeated re-meshing and interpolation. Moreover, the boundary conditions on the interfaces are imposed exactly. This work is intended to support the internal combustion engines simulator KIVA developed at Los Alamos National Laboratories. The model's capabilities are illustrated through application to incompressible flows in different geometrical settings that show the robustness and flexibility of the technique to perform simulations involving moving boundaries in a three-dimensional domain.

  11. Mixed convection boundary layer flow over a moving vertical flat plate in an external fluid flow with viscous dissipation effect.

    Directory of Open Access Journals (Sweden)

    Norfifah Bachok

    Full Text Available The steady boundary layer flow of a viscous and incompressible fluid over a moving vertical flat plate in an external moving fluid with viscous dissipation is theoretically investigated. Using appropriate similarity variables, the governing system of partial differential equations is transformed into a system of ordinary (similarity differential equations, which is then solved numerically using a Maple software. Results for the skin friction or shear stress coefficient, local Nusselt number, velocity and temperature profiles are presented for different values of the governing parameters. It is found that the set of the similarity equations has unique solutions, dual solutions or no solutions, depending on the values of the mixed convection parameter, the velocity ratio parameter and the Eckert number. The Eckert number significantly affects the surface shear stress as well as the heat transfer rate at the surface.

  12. Unsteady Unidirectional MHD Flow of Voigt Fluids Moving between Two Parallel Surfaces for Variable Volume Flow Rates

    OpenAIRE

    Wei-Fan Chen; Hsin-Yi Lai; Cha'o-Kuang Chen

    2012-01-01

    The velocity profile and pressure gradient of an unsteady state unidirectional MHD flow of Voigt fluids moving between two parallel surfaces under magnetic field effects are solved by the Laplace transform method. The flow motion between parallel surfaces is induced by a prescribed inlet volume flow rate that varies with time. Four cases of different inlet volume flow rates are considered in this study including (1) constant acceleration piston motion, (2) suddenly started flow, (3) linear ac...

  13. Heat transfer in a couple stress fluid over a continuous moving surface with internal hat generation and convective boundary conditions

    Energy Technology Data Exchange (ETDEWEB)

    Hayat, Tasawar [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Mathematics; King Saud Univ., Riyadh (Saudi Arabia). Dept. of Physics; Iqbal, Zahid [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Mathematics; Qasim, Muhammad [COMSATS Institute of Information Technology (CIIT), Islamabad (Pakistan). Dept. of Mathematics; Aldossary, Omar M. [King Saud Univ., Riyadh (Saudi Arabia). Dept. of Physics

    2012-05-15

    This investigation reports the boundary layer flow and heat transfer characteristics in a couple stress fluid flow over a continuos moving surface with a parallel free stream. The effects of heat generation in the presence of convective boundary conditions are also investigated. Series solutions for the velocity and temperature distributions are obtained by the homotopy analysis method (HAM). Convergence of obtained series solutions are analyzed. The results are obtained and discussed through graphs for physical parameters of interest. (orig.)

  14. Why do we have to move fluid to be able to breathe?

    Directory of Open Access Journals (Sweden)

    Martin eFronius

    2012-05-01

    Full Text Available The ability to breathe air represents a fundamental step in vertebrate evolution that was accompanied by several anatomical and physiological adaptations. The morphology of the air-blood barrier is highly conserved within air-breathing vertebrates. It is formed by three different plies, which are represented by the alveolar epithelium, the basal lamina and the endothelial layer. Besides these conserved morphological elements, another common feature of vertebrate lungs is that they contain a certain amount of fluid that covers the alveolar epithelium. The volume and composition of the alveolar fluid is regulated by transepithelial ion transport mechanisms expressed in alveolar epithelial cells. These transport mechanisms have been reviewed extensively. Therefore, the present review focuses on the properties and functional significance of the alveolar fluid. How does the fluid enter the alveoli? What is the fate of the fluid in the alveoli? What is the function of the alveolar fluid in the lungs? The review highlights the importance of the alveolar fluid, its volume and its composition. Maintenance of the fluid volume and composition within certain limits is critical to facilitate gas exchange. We propose that the alveolar fluid is an essential element of the air-blood barrier. Therefore, it is appropriate to refer to this barrier as being formed by four plies, namely (1 the thin fluid layer covering the apical membrame of the epithelial cells, (2 the epithelial cell layer, (3 the basal membrane, and (4 the endothelial cells.

  15. [Nitric Oxide in Modulation of Crystallogenic Propeties of Biological Fluid].

    Science.gov (United States)

    Martusevich, A K; Kovaleva, L K; Davyduk, A V

    2016-01-01

    The aim of this work was a comparative analysis of the influence of different NO forms on dehydration structurization of human blood serum. Blood specimens from 15 healthy people were treated by NO-containing gas flow (800 and 80 ppm) generated with the "Plazon" unit, experimental NO-generator (20, 50, 75 and 100 ppm) and by water solution of thiol-containing dinitrosyl iron complexes (3 mM/L). The influence of blood sodium on blood serum crystallization in original and NO-treated blood specimens was estimated. It was found, that the effect of NO on crystallogenic properties of blood serum depends directly on its concentration and form (free or bound), as well as on the presence of reactive oxygen species in gas flow. The most pronounced stimulating effect was observed for the bound form of NO--dinitrosyl iron complexes with glutathione ligands. Low NO concentrations modulated crystallogenic properties of blood serum and the most optimal stimulating action was demonstrated in gas flow containing 20 ppm nitric oxide. In contrast, high NO concentration (800 ppm) inhibited the crystallogenic activity of biological fluid with multiply increasing of structural elements destruction leading to the formation of an additional belt in marginal zone of dehydrated specimens. PMID:27192838

  16. Characterization of Nanoparticle Aggregation in Biologically Relevant Fluids

    Science.gov (United States)

    McEnnis, Kathleen; Lahann, Joerg

    Nanoparticles (NPs) are often studied as drug delivery vehicles, but little is known about their behavior in blood once injected into animal models. If the NPs aggregate in blood, they will be shunted to the liver or spleen instead of reaching the intended target. The use of animals for these experiments is costly and raises ethical questions. Typically dynamic light scattering (DLS) is used to analyze aggregation behavior, but DLS cannot be used because the components of blood also scatter light. As an alternative, a method of analyzing NPs in biologically relevant fluids such as blood plasma has been developed using nanoparticle tracking analysis (NTA) with fluorescent filters. In this work, NTA was used to analyze the aggregation behavior of fluorescent polystyrene NPs with different surface modifications in blood plasma. It was expected that different surface chemistries on the particles will change the aggregation behavior. The effect of the surface modifications was investigated by quantifying the percentage of NPs in aggregates after addition to blood plasma. The use of this characterization method will allow for better understanding of particle behavior in the body, and potential problems, specifically aggregation, can be addressed before investing in in vivo studies.

  17. Studies of cell toxicity of complexes of magnetic fluids and biological macromolecules

    International Nuclear Information System (INIS)

    In this study, we performed a comparative investigation of the binding properties of two surface-coated (carboxymethyldextran/glucuronic acid), magnetite-based biocompatible magnetic fluids with different biological macromolecules (BSA, HSA, and LDL). We also investigated the in vitro toxicity of the complex formed between the magnetic fluid and the biological macromolecule in the neoplastic cell line J774-A

  18. Studies of cell toxicity of complexes of magnetic fluids and biological macromolecules

    Science.gov (United States)

    Macaroff, Patrícia P.; Oliveira, Daniela M.; Ribeiro, Karina F.; Lacava, Zulmira G. M.; Lima, Emília C. D.; Morais, Paulo C.; Tedesco, Antonio C.

    2005-05-01

    In this study, we performed a comparative investigation of the binding properties of two surface-coated (carboxymethyldextran/glucuronic acid), magnetite-based biocompatible magnetic fluids with different biological macromolecules (BSA, HSA, and LDL). We also investigated the in vitro toxicity of the complex formed between the magnetic fluid and the biological macromolecule in the neoplastic cell line J774-A.

  19. EFFECT OF A MOVING BOUNDARY ON THE FLUID TRANSIENT FLOW IN LOW PERMEABILITY RESERVOIRS

    Institute of Scientific and Technical Information of China (English)

    LUO Wan-Jing; WANG Xiao-dong

    2012-01-01

    In a low permeability reservoir,the existence of a moving boundary is considered in the study of the transient porous flow with threshold pressure gradient.The transmission of the moving boundary directly indicates the size of the drainage area as well as the apparent influences on the pressure behavior.The nonlinear transient flow mathematical model in which the threshold pressure gradient and the moving boundary are incorporated is solved by advanced mathematical methods.This paper presents some new analytical solutions describing the pressure distribution at a constant rate and the production decline in a constant pressure production with the boundary propagation.It is shown that the greater the threshold pressure gradient,the slower the transmission of the moving boundary,the larger the pressure loss will be,and there is no radial flow in the middle and later phases of the wellface pressure for a well at a constant rate.We have the the maximum moving boundary at a specific drawdown pressure for a low permeability reservoir.The greater the threshold pressure gradient,the smaller the maximum moving boundary distance,the quieker the production decline for a well in a constant pressure production will be.The type curve charts for the modem well test analysis and the rate transient analysis with a moving boundary are obtained and the field test and the production data are interpreted as examples to illustrate how to use our new results.

  20. Variational Approach Applied to Study the Lifting of a Non-Newtonian Fluid on a Vertically Moving Belt

    Directory of Open Access Journals (Sweden)

    Ali Ahmad FAROOQ

    2014-03-01

    Full Text Available This paper provides an investigation regarding the modeling and analysis of the thin film flow of a non-Newtonian Williamson fluid on a vertically moving belt. The governing nonlinear differential equation is first integrated analytically and then solved by using the Variational Iteration Method (VIM. The results of the present method are also compared with those obtained by the Adomian Decomposition Method (ADM and a very good agreement is observed. This comparison reveals that VIM may be considered as an efficient alternative method for solving nonlinear problems arising in the area of fluid mechanics. Expressions for some important physical quantities such as volume flux, average velocity, the belt speed for the lifting of non-Newtonian fluid are also derived.doi:10.14456/WJST.2014.74

  1. An assessment of the moving point method for numerical calculation of fluid-structure interaction in water hammer

    International Nuclear Information System (INIS)

    The problem of providing an accurate numerical method for modelling fluid-structure interaction in practical water hammer calculations for power station pipe networks is addressed. The application of the moving point method to a problem representative of practical water hammer is presented. A suitable model including both liquid pressure waves and pipe wall tension waves if formulated as a set of partial differential equations with algebraic equations and boundary and initial conditions. The problem is non-dimensionalized, to identify key parameters, and a suitable linearized problem is constructed by omitting small terms. The problem is transformed to characteristic variables which are shown to be simply transported along the pipe without change of value. This motivates the choice of the moving point method. In the course of the work a program WHOMP (Water Hammer On Moving Points) was developed which exploits the moving point method. It is specific to the problem of a single pipe with thin elastic walls but the boundary and initial conditions permitted are sufficiently general that any reasonable physical problem for a single pipe can be addressed. Results of WHOMP for the model problem are compared with experimental and other numerical results including superficially those from a commercially available code FLUSTRIN. Some consideration of extending the moving point method to practical pipe networks is given. This includes the incorporation of bending and torsion waves in the pipe wall and incorporation of additional physics leading to significant non-linearity. (author)

  2. Fluid dynamics of moving fish in a two-dimensional multiparticle collision dynamics model

    NARCIS (Netherlands)

    Reid, Daniel A. P.; Hildenbrandt, H.; Hemelrijk, C. K.; Padding, J.T.

    2012-01-01

    The fluid dynamics of animal locomotion, such as that of an undulating fish, are of great interest to both biologists and engineers. However, experimentally studying these fluid dynamics is difficult and time consuming. Model studies can be of great help because of their simpler and more detailed an

  3. Role of Moving Bed Biofilm Reactor and Sequencing Batch Reactor in Biological Degradation of Formaldehyde Wastewater

    Directory of Open Access Journals (Sweden)

    B. Ayati

    2011-10-01

    Full Text Available Nowadays formaldehyde is used as raw material in many industries. It has also disinfection applications in some public places. Due to its toxicity for microorganisms, chemical or anaerobic biological methods are applied for treating wastewater containing formaldehyde.In this research, formaldehyde removal efficiencies of aerobic biological treatment systems including moving bed biofilm (MMBR and sequencing batch reactors (SBR were investigated. During all experiments, the efficiency of SBR was more than MBBR, but the difference was not significant statistically. According to the results, the best efficiencies were obtained for influent formaldehyde COD of 200 mg/L in MBBR and SBR which were 93% and 99.4%, respectively. The systems were also capable to treat higher formaldehyde concentrations (up to 2500 mg/L with lower removal efficiency. The reaction kinetics followed the Stover-Kincannon second order model. The gram-positive and gram-negative bacillus and coccus as well as the gram-positive binary bacillus were found to be the most dominant species. The results of 13C-NMR analysis have shown that formaldehyde and urea were converted into N-{[(aminocarbonyl amino] methyl}urea and the residual formaldehyde was polymerized at room temperature.

  4. Unsteady Unidirectional MHD Flow of Voigt Fluids Moving between Two Parallel Surfaces for Variable Volume Flow Rates

    Directory of Open Access Journals (Sweden)

    Wei-Fan Chen

    2012-01-01

    Full Text Available The velocity profile and pressure gradient of an unsteady state unidirectional MHD flow of Voigt fluids moving between two parallel surfaces under magnetic field effects are solved by the Laplace transform method. The flow motion between parallel surfaces is induced by a prescribed inlet volume flow rate that varies with time. Four cases of different inlet volume flow rates are considered in this study including (1 constant acceleration piston motion, (2 suddenly started flow, (3 linear acceleration piston motion, and (4 oscillatory piston motion. The solution for each case is elaborately derived, and the results of associated velocity profile and pressure gradients are presented in analytical forms.

  5. On the linear problem arising from motion of a fluid around a moving rigid body

    Czech Academy of Sciences Publication Activity Database

    Nečasová, Šárka; Wolf, J.

    2015-01-01

    Roč. 140, č. 2 (2015), s. 241-259. ISSN 0862-7959 R&D Projects: GA ČR(CZ) GAP201/11/1304 Institutional support: RVO:67985840 Keywords : incompressible fluid * rotating rigid body * strong solution Subject RIV: BA - General Mathematics http://hdl.handle.net/10338.dmlcz/144329

  6. Using of electrodiffusion measurement method for hydrodymanic investigation of bodies moving in fluid under restraint conditions

    Czech Academy of Sciences Publication Activity Database

    Berman, V. P.; Fadeichev, V. V.; Vlasák, Pavel

    Kiev: Nacionalnij techničnij universitet Ukraini Kiivskij politechničnij institut, 1998, s. 236-237. [Measurement 98. Kiev (UA), 07.09.1998-10.09.1998] R&D Projects: GA AV ČR KSK1076602 Keywords : lift off-force * electrodiffusion method * capsule flow Subject RIV: BK - Fluid Dynamics

  7. Enantiomers separation by simulated moving bed chromatography. Non-instantaneous equilibrium at the solid-fluid interface.

    Science.gov (United States)

    Azevedo, D C; Pais, L S; Rodrigues, A E

    1999-12-31

    The simulated moving bed (SMB) technology, first conceived for large bulk-scale separations in the petrochemical industry, has found increasingly new applications in the pharmaceutical industry. Among these, the separation of fine chemicals has been the subject of considerable study and research. This work presents the modeling, simulation and design of the operation of a SMB plant in order to separate a binary chiral mixture. The usual assumption of instantaneous equilibrium at the solid-fluid interface is questioned and a first-order kinetics of adsorption is taken into account. The cases of linear, Langmuir and modified Langmuir equilibria are studied. The equivalent true moving bed (TMB) model was used assuming axial dispersion for the fluid flow and plug flow for the solid-phase flow. Intraparticle diffusion was described by a linear driving force (LDF) approximation. Simulation results indicate that, under certain conditions, equilibrium is not actually reached at the adsorbent surface. This leads to different unit performances, in terms of product purities and recoveries, as compared to those predicted assuming instantaneous equilibrium. Moreover, SMB units may be improperly designed by the usual methods (flow-rate ratio separation regions) if non-equilibrium effects are overlooked. PMID:10674941

  8. Drag force, drag torque, and Magnus force coefficients of rotating spherical particle moving in fluid

    Czech Academy of Sciences Publication Activity Database

    Lukerchenko, Nikolay; Kvurt, Y.; Keita, Ibrahima; Chára, Zdeněk; Vlasák, Pavel

    2012-01-01

    Roč. 30, č. 1 (2012), s. 55-67. ISSN 0272-6351 R&D Projects: GA AV ČR IAA200600603; GA ČR GA103/09/1718 Institutional research plan: CEZ:AV0Z20600510 Keywords : drag force * drag torque * Magnus force * Reynolds number * rotational Reynolds number Subject RIV: BK - Fluid Dynamics Impact factor: 0.435, year: 2012

  9. Application of Moving Bed Biofilm Process for Biological Organics and Nutrients Removal from Municipal Wastewater

    OpenAIRE

    M. Kermani; B BINA; Haji Movahedian; Amin, M. M.; M. Nikaein

    2008-01-01

    In this study, experiments have been conducted to evaluate the organics and nutrients removal from synthetic wastewater by a laboratory scale moving bed biofilm process. For nutrients removal, moving bed biofilm process has been applied in series with anaerobic, anoxic and aerobic units in four separate reactors. Moving bed biofilm reactors were operated continuously at different loading rates of nitrogen and Phosphorus. During optimum conditions, close to complete nitrification with average ...

  10. Ultrasonic wave propagation in thermoviscous moving fluid confined by heating pipeline and flow measurement performance.

    Science.gov (United States)

    Chen, Yong; Huang, Yiyong; Chen, Xiaoqian

    2013-09-01

    Ultrasonic wave propagation in thermoviscous fluid with pipeline shear mean flow in the presence of a temperature gradient is investigated. On the assumption of irrotational and axisymmetric wave propagation, a mathematical formulation of the convected wave equation is proposed without simplification in the manner of Zwikker and Kosten. A method based on the Fourier-Bessel theory, which is complete and orthogonal in Lebesgue space, is introduced to convert the wave equations into homogeneous algebraic equations. Then numerical calculation of the axial wavenumber is presented. In the end, wave attenuation in laminar and turbulent flow is numerically studied. Meanwhile measurement performance of an ultrasonic flow meter is parametrically analyzed. PMID:23967920

  11. Stochastic moving particle semi-implicit for inviscid fluid wave simulation

    CERN Document Server

    Naa, Christian Fredy; Kazama, Masaki

    2013-01-01

    The present paper introduces stochastic velocity as improvement for moving particle semi-implicit (MPS) method. This improvement is to overcome energy loss caused by numerical dissipation in the basic MPS that brings about rapid decay of waves. Stochastic velocity is added in the explicit step of the basic MPS method. MPS with stochastic improvement is compared with the basic method in the case of linear water waves, in particular dam break problem and standing wave in a rectangular tank. Surface detection and curve fitting are used to analyze the parameters of wave on the standing wave case. The surface detection and curved fitting was efficient to determine parameters of the wave and it was found that the stochastic improvement made the waves survived longer than in the basis method.

  12. Time-Accurate Computational Fluid Dynamics Simulation of a Pair of Moving Solid Rocket Boosters

    Science.gov (United States)

    Strutzenberg, Louise L.; Williams, Brandon R.

    2011-01-01

    Since the Columbia accident, the threat to the Shuttle launch vehicle from debris during the liftoff timeframe has been assessed by the Liftoff Debris Team at NASA/MSFC. In addition to engineering methods of analysis, CFD-generated flow fields during the liftoff timeframe have been used in conjunction with 3-DOF debris transport methods to predict the motion of liftoff debris. Early models made use of a quasi-steady flow field approximation with the vehicle positioned at a fixed location relative to the ground; however, a moving overset mesh capability has recently been developed for the Loci/CHEM CFD software which enables higher-fidelity simulation of the Shuttle transient plume startup and liftoff environment. The present work details the simulation of the launch pad and mobile launch platform (MLP) with truncated solid rocket boosters (SRBs) moving in a prescribed liftoff trajectory derived from Shuttle flight measurements. Using Loci/CHEM, time-accurate RANS and hybrid RANS/LES simulations were performed for the timeframe T0+0 to T0+3.5 seconds, which consists of SRB startup to a vehicle altitude of approximately 90 feet above the MLP. Analysis of the transient flowfield focuses on the evolution of the SRB plumes in the MLP plume holes and the flame trench, impingement on the flame deflector, and especially impingment on the MLP deck resulting in upward flow which is a transport mechanism for debris. The results show excellent qualitative agreement with the visual record from past Shuttle flights, and comparisons to pressure measurements in the flame trench and on the MLP provide confidence in these simulation capabilities.

  13. Assessment of the impact of moving fluids on the regional thermal field for the area of Brandenburg (North German Basin)

    Science.gov (United States)

    Noack, V.; Scheck-Wenderoth, M.; Cacace, M.; Lewerenz, B.

    2012-04-01

    We present results from numerical simulations of the 3D thermal field for the area of Brandenburg in the North German Basin. The study area encompasses a part of the basin centre in the north, whereas to the south the basin margin is enclosed. Starting with Permocarboniferous volcanic rocks the basin fill is represented by Permian to Cenozoic sediments. A thick layer of mobilized salt (Zechstein, Upper Permian) generated elevated structures such as salt pillows and diapirs. Especially where diapirs pierce their overburden, the overlying deposits are strongly influenced in their thickness and distribution. This special configuration of the Zechstein salt is relevant for the thermal calculations due to the fact that salt has a distinctly higher thermal conductivity than the surrounding sediments and is impermeable to fluid flow. Therefore, the Zechstein salt acts as a conductive chimney for heat and a hydraulic decoupling horizon between the Pre-Permian and the Mesozoic-Cenozoic strata. The latter are characterized by two further quasi-impervious sediment complexes, the Rupelian-clay and the Muschelkalk. These two divide the Post-Permian strata in three main aquifer systems: the Buntsandstein, Keuper to Pre-Rupelian and the Post-Rupelian complex. Based on results from purely conductive modelling we additionally analyse the influence of moving fluids on the shallow temperature field above the Zechstein salt. Therefore coupled fluid flow and heat transfer numerical simulations are carried out to investigate the hydrothermal field. The 3D simulations for the heat transport processes are based on the finite element method. The results indicate that the distribution of thermal conductivities in the basin fill controls the short-wavelength pattern of the temperature distribution whereas the long wavelength pattern results from interaction between the highly conductive crust and low conductive sediments. Furthermore, the results reveal that the shallow temperature field

  14. Vanishing condition for the heat flux of a relativistic fluid in a moving frame

    International Nuclear Information System (INIS)

    It has been asked if is appropriate to introduce the heat flow in the energy- momentum tensor, due to the non-mechanical nature of heat [1]. Although this could be answered by both kinetic and symmetry arguments, we address the problem by checking the validity of the second law of thermodynamics in a fluid that is boosted by a Lorentz transformation to a non comoving frame. In this contribution we found that this only can happen under certain conditions. Indeed, we found that there are a family of reference frames that satisfies these conditions, where Landau-Lifshitz frame is one of those. Additionally we relate such conditions with the null energy condition and the entropy production

  15. Optimal Analysis of Sulfonamides From Biological Matrices Using Supercritical Fluids

    OpenAIRE

    Combs, Michael T.

    1997-01-01

    The objective of this research was to develop new sample preparation procedures for the isolation of sulfonamides, as well as, to determine the applicability of employing on-line nitrogen selective and mass spectrometric detection methods. The first phase of this research investigated the effect of temperature and pressure on the supercritical fluid extraction (SFE) of sulfonamides from a spiked sand matrix. Temperature effects were either positive or negative with respect to extraction ...

  16. Conception and realization of a new viscometer using a magnetic fluid for measuring biological fluids.

    Science.gov (United States)

    Brancher, J P; Lucius, M; Bernardin, D; Raihani, R; Stoltz, J F

    1984-01-01

    The viscometer described in this paper comprises a vertical cylinder containing the fluid to be tested and an inner, hollow cylinder floating in the fluid and filled with magnetic liquid. The magnetic liquid and inner cylinder are set in motion by applying a rotating magnetic field. Torque is balanced by the stresses in the fluid and the inertia of the rotating cylinder. The main characteristics of this new apparatus are: - possibility of applying various torques to the rotor. Measurements of angular velocity are made on the inner cylinder (in general, conventional viscometers are built on the opposite principle), - study in transient flow. Various measurements on Newtonian fluids (water, plasma, oils, etc.) and on blood suspensions have made it possible to improve the accuracy of the method. PMID:6592002

  17. Bovine placental lactogen: isolation purification and measurement in biological fluids

    International Nuclear Information System (INIS)

    Studies were conducted to isolate and purify bovine placental lactogen (bPL) and to develop a radioimmunoassay to this protein. Bovine placental lactogen was isolated from culture medium after a 24 hr culture of fetal cotyledonary tissue. Cotyledonary explants were stimulated to secrete bPL by either addition of bovine growth hormone (NIH-B8) to the medium or co-culture of cotyledon and caruncular tissue. Production of bPL was greatly affected by explant size and 70% of that produced in a 48 hr culture was released in the first 12 hr. Purification of bPL was accomplished using a column chromatographic scheme that involved gel filtration, ion exchange and chromatofocusing chromatography. A radioimmunoassay to bPL was developed using an antibody raised at the USDA Beltsville (F56). Dose response curves of amniotic or allantoic fluid or fetal and maternal serum were parallel to the standard curve and bPL was quantitatively recovered at from 82-125%. Using the radioimmunoassay, samples of amniotic and allantoic fluids and fetal and maternal serum were measured for bPL. Concentrations of bPL ranged from undetectable to 50 ng/ml, with fetal blood having the highest concentrations and amniotic fluid the lowest

  18. SURFACE EFFECTS OF INTERNAL WAVE GENERATED BY A MOVING SOURCE IN A TWO-LAYER FLUID OF FINITE DEPTH

    Institute of Scientific and Technical Information of China (English)

    魏岗; 乐嘉春; 戴世强

    2003-01-01

    Based on the potential flow theory of water waves, the interaction mechanism between the free- surface and internal waves generated by a moving point source in the lower layer of a two- layer fluid was studied. By virtue of the method of Green' s function, the properties of the divergence field at the free surface were obtained, which plays an important role in the SAR ( Synthetic Aperture Radar) image. It is shown that the coupling interaction between the surface-wave mode and internal-wave mode must be taken into account for the cases of large density difference between two layers, the source approaching to the pynocline and the total Froude number Fr close to the critical number Fr2 . The theoretical analysis is qualitatively consistent with the experimental results presented by Ma Hui-yang.

  19. A Numerical Study on Water Waves Generated by A Submerged Moving Body in A Two-Layer Fluid System

    Institute of Scientific and Technical Information of China (English)

    YANG Jia-Zhen; NG Chiu-On; ZHANG Dao-Hua

    2009-01-01

    This is a numerical study on the time development of surface waves generated by a submerged body moving steadily in a two-layer fluid system, in which a layer of water is underlain by a layer of viscous mud. The fully nonlinear Navier-Stokes equations are solved on FLUENT with the Volume-of-Fluid (VOF) multiphase scheme in order to simulate the free surface waves as well as the water-mud interface waves as functions of time. The numerical model is validated by mimick-ing a reported experiment in a one-layer system before it is applied to a two-layer system, it is found that the presence of bottom mud in a water layer can lead to large viscous damping of the surface waves. For the investigation of the problem systematically, the effects of the Froude number and the mud layer thickness, density and viscosity relative to those of water are evaluated and discussed in detail.

  20. Entropy Generation Analysis of Power-Law Non-Newtonian Fluid Flow Caused by Micropatterned Moving Surface

    Directory of Open Access Journals (Sweden)

    M. H. Yazdi

    2014-01-01

    Full Text Available In the present study, the first and second law analyses of power-law non-Newtonian flow over embedded open parallel microchannels within micropatterned permeable continuous moving surface are examined at prescribed surface temperature. A similarity transformation is used to reduce the governing equations to a set of nonlinear ordinary differential equations. The dimensionless entropy generation number is formulated by an integral of the local rate of entropy generation along the width of the surface based on an equal number of microchannels and no-slip gaps interspersed between those microchannels. The velocity, the temperature, the velocity gradient, and the temperature gradient adjacent to the wall are substituted into this equation resulting from the momentum and energy equations obtained numerically by Dormand-Prince pair and shooting method. Finally, the entropy generation numbers, as well as the Bejan number, are evaluated. It is noted that the presence of the shear thinning (pseudoplastic fluids creates entropy along the surface, with an opposite effect resulting from shear thickening (dilatant fluids.

  1. Cystatin C and lactoferrin concentrations in biological fluids as possible prognostic factors in eye tumor development

    Directory of Open Access Journals (Sweden)

    Mariya A. Dikovskaya

    2013-08-01

    Full Text Available Objectives. To investigate the possible role of cystatin C in eye biological fluids locally and in serum and lactoferrin revealing anti-tumor activity in eye tumor development. Background. The increased number of eye tumors was registered recently not only in the countries with high insolation, but also in the northern countries including Russia (11 cases per million of population. Search for new biological markers is important for diagnosis and prognosis in eye tumors. Cystatin C, an endogenous inhibitor of cysteine proteases, plays an important protective role in several tumors. Lactoferrin was shown to express anti-tumor and antiviral activities. It was hypothesized that cystatin C and lactoferrin could serve as possible biomarkers in the diagnosis of malignant and benign eye tumors. Study design. A total of 54 patients with choroidal melanoma and benign eye tumors were examined (part of them undergoing surgical treatment. Serum, tear fluid and intraocular fluid samples obtained from the anterior chamber of eyes in patients with choroidal melanoma were studied. Methods. Cystatin C concentration in serum and eye biological fluids was measured by commercial ELISA kits for human (BioVendor, Czechia; lactoferrin concentration – by Lactoferrin-strip D 4106 ELISA test systems (Vector-BEST, Novosibirsk Region, Russia. Results. Cystatin C concentration in serum of healthy persons was significantly higher as compared to tear and intraocular fluids. In patients with choroidal melanoma, increased cystatin C concentration was similar in tear fluid of both the eyes. Lactoferrin level in tear fluid of healthy persons was significantly higher than its serum level. Significantly increased lactoferrin concentration in tear fluid was noted in patients with benign and malignant eye tumors. Conclusion. Increased level of cystatin C in tear fluid seems to be a possible diagnostic factor in the eye tumors studied. However, it does not allow us to differentiate

  2. Pattern formation in biological fluids II: cell deformation in shear fields evidences convective membrane organisation

    OpenAIRE

    Lofthouse, Juanita

    2004-01-01

    The mechanical behaviour and symmetry-breaking shape deformation of red blood cells subjected to shear flows is used to demonstrate that far from being random fluids, both the membrane and cytoplasm of every biological cell undergo spatially organised convective and shear driven flows when the cell maintains a Near Equilibrium state through continuousmetabolic activity. The model demonstrates that fluid bifurcation events drive cell shape changes, rather than a Meccano like cytoskeletal struc...

  3. A radioenzymatic technique for the measurement of free and conjugated 3,4-dihydroxyphenylethyleneglycol in brain tissue and biological fluids

    International Nuclear Information System (INIS)

    A simple, sensitive and specific radioenzymatic assay for the measurement of 3,4-dihydroxyphenylethyleneglycol (DOPEG) was developed. The assay is based on the conversion of the compound to its O-methylated derivative in the presence of catechol-O-methyltransferase and [3H]S-adenosyl-methionine. The tritiated 3-methoxy-4-hydroxyphenylethyleneglycol formed is selectively extracted in organic solvents and isolated by thin layer chromatography. After oxidation to vanillin the O-methylated compound is extracted and measured by liquid scintillation spectrophotometry. This assay has been applied to the measurement of free and conjugated DOPEG is a variety of biological tissues and fluids. Both free and conjugated DOPEG were readily detected in discrete rat brain areas. Substantial amounts of free and conjugated DOPEG were also measured in ventricular perfusates from freely moving rats. Finally, the presence of DOPEG was also demonstrated in human cerebrospinal fluid, plasma and urine. Only the free form of DOPEG was found in cerebrospinal fluid, whereas both unconjugated and conjugated forms were present in plasma and urine. (Auth.)

  4. Controlling the Mobility of the Fluid Interface of Moving Gas Bubbles or Liquid Drops by Using Micellar Solutions of Surfactants

    Science.gov (United States)

    Maldarelli, Charles; Papageorgiou, Demetrios

    1998-01-01

    Microgravity processes must rely on mechanisms other than buoyancy to move bubbles or droplets from one region to another in a continuous liquid phase. One suggested method is thermocapillary migration in which a temperature gradient is applied to the continuous phase. A significant and as yet unresolved impediment to the use of thermocapillary migration to direct bubble or drop motion is that these migrations can be significantly retarded by the adsorption onto the fluid particle surface of surface active impurities unavoidably present in the continuous or (if the particle is a liquid) droplet phases. The focus of our research was to develop a theory for remobilizing fluid particle interfaces retarded by a surfactant impurity in an effort to make more viable the use of thermocapillary migrations for the management of bubbles and drops in microgravity. We postulated that a surfactant at high bulk concentration which kinetically exchanges rapidly with the surface can restore interface mobility. The scaling arguments along with a discussion of the previous literature is reviewed in the context of the scaling framework. The specific objectives of the research were twofold. The first was to prove the remobilization theory by studying a model problem. As the mechanism for remobilization is independent of the force which drives the particle, the fluid particle shape and the presence of fluid inertia, we chose the simplest model consisting of a spherical bubble rising steadily by buoyancy in creeping flow. We solved the hydrodynamic and surfactant transport equations for rapid kinetic exchange to demonstrate that as the concentration increases, the Marangoni retardation at first increases (the low k behavior) and then decreases (the high k behavior). The second objective was to develop a method to determine the kinetic rate constants of a surfactant molecule, since this information is necessary to select surfactants which will exchange rapidly enough relative to the

  5. Application of Moving Bed Biofilm Process for Biological Organics and Nutrients Removal from Municipal Wastewater

    Directory of Open Access Journals (Sweden)

    M. Kermani

    2008-01-01

    Full Text Available In this study, experiments have been conducted to evaluate the organics and nutrients removal from synthetic wastewater by a laboratory scale moving bed biofilm process. For nutrients removal, moving bed biofilm process has been applied in series with anaerobic, anoxic and aerobic units in four separate reactors. Moving bed biofilm reactors were operated continuously at different loading rates of nitrogen and Phosphorus. During optimum conditions, close to complete nitrification with average ammonium removal efficiency of 99.72% occurred in the aerobic reactor. In the aerobic reactor, the average specific nitrification rate was 1.8 g NOx-N kg VSS-1 h-1. The results of the average effluent soluble COD concentration from each reactor showed that denitrification process in the second anoxic reactor consumed most of the biodegradable organic matter. As seen from the results, denitrification rate has increased with increasing NOx-N loading in the second anoxic reactor. The aerobic phosphate removal rate showed a good correlation to the anaerobic phosphate release rate. Moreover, phosphate removal rate showed a strong correlation to the phosphate loading rate in the aerobic reactor. In optimum conditions, the average SCOD, total nitrogen and phosphorus removal efficiencies were 96.9, 84.6 and 95.8%, respectively. This study showed that the moving bed biofilm process could be used as an ideal and efficient option for the total nutrient removal from municipal wastewater.

  6. Method for detection of a suspect viral deoxyribonucleic acid in an acellular biological fluid

    International Nuclear Information System (INIS)

    A method for evaluating an acellular biological fluid for the presence of a suspect viral DNA, such as DNA of the Hepatitis-B virus, is described. The acellular biological fluid is treated to immobilize in denatured form the DNAs including the suspect viral DNA on a solid substrate. This substrate is contacted with a solution including radioisotopically-labelled suspect viral denatured DNA to renature the immobilized suspect viral native DNA. The solid substrate is then evaluated for radioisotopically-labelled suspect viral renatured DNA. (author)

  7. Teaching Fluid Mechanics for Undergraduate Students in Applied Industrial Biology: from Theory to Atypical Experiments

    CERN Document Server

    Absi, Rafik; Dufour, Florence; Huet, Denis; Bennacer, Rachid; Absi, Tahar

    2011-01-01

    EBI is a further education establishment which provides education in applied industrial biology at level of MSc engineering degree. Fluid mechanics at EBI was considered by students as difficult who seemed somewhat unmotivated. In order to motivate them, we applied a new play-based pedagogy. Students were asked to draw inspiration from everyday life situations to find applications of fluid mechanics and to do experiments to verify and validate some theoretical results obtained in course. In this paper, we present an innovative teaching/learning pedagogy which includes the concept of learning through play and its implications in fluid mechanics for engineering. Examples of atypical experiments in fluid mechanics made by students are presented. Based on teaching evaluation by students, it is possible to know how students feel the course. The effectiveness of this approach to motivate students is presented through an analysis of students' teaching assessment. Learning through play proved a great success in fluid...

  8. Numerical Solution of Unsteady Hydromagnetic Natural Convection Flow of Heat Absorbing Fluid past an Impulsively Moving Vertical Plate with Ramped Temperature

    Directory of Open Access Journals (Sweden)

    Gauri Shanker Seth

    2013-03-01

    Full Text Available A numerical investigation of unsteady hydromagnetic natural convection flow of a viscous, incompressible, electrically conducting and heat absorbing fluid past an impulsively moving vertical plate with ramped temperature embedded a porous medium in the presence of thermal diffusion is carried out. The governing equations are solved numerically by Crank-Nicolson implicit finite difference scheme. The numerical solution for fluid velocity and fluid temperature are depicted graphically whereas the numerical values of skin friction and Nusselt number are presented in tabular form for various values of pertinent flow parameters. Natural convection flow near a ramped temperature plate is also compared with the flow near an isothermal plate.

  9. An expanded role for microbial physiology in metabolic engineering and functional genomics: moving towards systems biology

    DEFF Research Database (Denmark)

    Nielsen, Jens; Olsson, Lisbeth

    2002-01-01

    . With the progress in molecular biology it has become possible to optimize industrial fermentations through introduction of directed genetic modification - an approach referred to as metabolic engineering. Furthermore, as a consequence of large sequencing programs the complete genomic sequence has...... system (the cell), also at the quantitative level, and this is the goal of systems biology. Clearly this will have a significant impact on microbial physiology as well as on metabolic engineering....

  10. Drag Force of Non-newtonian Fluid on a Continuous Moving Surface with Strong Suction/Blowing

    Institute of Scientific and Technical Information of China (English)

    郑连存; 张欣欣; 赫冀成

    2003-01-01

    A theoretical analysis for the laminar boundary layer flow of a non-Newtonian fluid on a continuous moving flat plate with surface strong suction/blowing is made. The types of potential flows necessary for similar solutions to the boundary layer are determined and both analytical and numerical solutions are presented. It is shown that the solution of the boundary layer problem depends not only on the ratio of the velocity of the plate to the velocity of the free stream, but also on the suction/blowing parameter. The skin friction decreases with increasing the parameters of power law and blowing. In the case of existing suction, the shear force decreases with the increases of tangential velocity, the largest shear force occurs at wall and the smallest shear force occurs at the edge of the boundary layer. However, in the case of existing surface blowing, the shear force initially increases with tangentialvelocity and the biggest shear force occurs at the interior of the boundary layer, the skin friction approaches to zero as the blowing rate approaches the critical value.

  11. Experimental study of quasi-2D dipolar vortex streets generated by a moving momentum source in a stratified fluid

    Science.gov (United States)

    Chen, K.; You, Y.; Noblesse, F.

    2016-07-01

    Experiments are conducted in a linear stratified fluid with a momentum source modeled via a nozzle jet moving horizontally. The generation mechanism of the quasi-two-dimensional dipolar vortex streets is investigated and their evolution characteristics are analyzed. Observation shows that the formation of a dipolar vortex street requires a nonzero motion of the nozzle in addition to conditions of the Reynolds and Froude number (Re, Fr). The (Re, Fr) condition that the dipolar vortex streets can be generated is determined via experimental measurements. The explanation for the absence of such a vortex street can be the low energy of the jet and the strong body-effect disturbance of the solid nozzle. The dependence of the vortex street dimensionless formation time τ and the Strouhal number St on the Froude number Fr or the Reynolds number Re is analyzed. This analysis shows that τ and St appear to be independent of Re and approximately have power-law relations with Fr via data fitting. The exponents of Fr in the two power-law functions are -0.27 for τ and -0.21 for St, while the constant coefficients are 65 and 0.21.

  12. Moving Away from Dogmatic Knowledge Dissemination in a Cell Biology Module: Examples from Singapore

    Science.gov (United States)

    Yeong, Foong May

    2012-01-01

    A surge in the amount of information in the discipline of Cell Biology presents a problem to the teaching of undergraduates under time constraints. In most textbooks and during lectures, students in Singapore are often taught in a dogmatic manner where concepts and ideas are expounded to them. The students in turn passively receive the materials…

  13. An expanded role for microbial physiology in metabolic engineering and functional genomics: moving towards systems biology

    DEFF Research Database (Denmark)

    Nielsen, Jens; Olsson, Lisbeth

    2002-01-01

    Microbial physiology has traditionally played a very important role in both fundamental research and in industrial applications of microorganisms. The classical approach in microbial physiology has been to analyze the role of individual components (genes or proteins) in the overall cell function....... system (the cell), also at the quantitative level, and this is the goal of systems biology. Clearly this will have a significant impact on microbial physiology as well as on metabolic engineering.......Microbial physiology has traditionally played a very important role in both fundamental research and in industrial applications of microorganisms. The classical approach in microbial physiology has been to analyze the role of individual components (genes or proteins) in the overall cell function....... With the progress in molecular biology it has become possible to optimize industrial fermentations through introduction of directed genetic modification - an approach referred to as metabolic engineering. Furthermore, as a consequence of large sequencing programs the complete genomic sequence has...

  14. Systems Biology of cancer: Moving toward the Integrative Study of the metabolic alterations in cancer cells.

    Directory of Open Access Journals (Sweden)

    Claudia Erika Hernández Patiño

    2013-01-01

    Full Text Available One of the main objectives in systems biology is to understand the biological mechanisms that give rise to the phenotype of a microorganism by using high-throughput technologies and genome-scale mathematical modeling. The computational modeling of genome-scale metabolic reconstructions is one systemic and quantitative strategy for characterizing the metabolic phenotype associated with human diseases and potentially for designing drugs with optimal clinical effects. The purpose of this short review is to describe how computational modeling, including the specific case of constraint-based modeling, can be used to explore, characterize and predict the metabolic capacities that distinguish the metabolic phenotype of cancer cell lines. As we show herein, this computational framework is far from a pure theoretical description, and to ensure proper biological interpretation, it is necessary to integrate high-throughput data and generate predictions for later experimental assessment. Hence, genome-scale modeling serves as a platform for the following: 1 the integration of data from high-throughput technologies, 2 the assessment of how metabolic activity is related to phenotype in cancer cell lines and 3 the design of new experiments to evaluate the outcomes of the in silico analysis. By combining the functions described above, we show that computational modeling is a useful methodology to construct an integrative, systemic and quantitative scheme for understanding the metabolic profiles of cancer cell lines, a first step to determine the metabolic mechanism by which cancer cells maintain and support their malignant phenotype in human tissues.

  15. Pattern formation in biological fluids II: cell deformation in shear fields evidences convective membrane organisation

    CERN Document Server

    Lofthouse, J

    2004-01-01

    The mechanical behaviour and symmetry-breaking shape deformation of red blood cells subjected to shear flows is used to demonstrate that far from being random fluids, both the membrane and cytoplasm of every biological cell undergo spatially organised convective and shear driven flows when the cell maintains a Near Equilibrium state through continuousmetabolic activity. The model demonstrates that fluid bifurcation events drive cell shape changes, rather than a Meccano like cytoskeletal structure, and represents a significant Gestalt shift in models of cell mechanics.

  16. Transformation of vortex structures in the wake of a sphere moving in the stratified fluid with decreasing of internal Froude number

    International Nuclear Information System (INIS)

    The 3D separated, density stratified viscous fluid flows around a sphere are investigated by means of the direct numerical simulation (DNS) on the basis of the Navier-Stokes equations in the Boussinesq approximation on the supercomputers at the wide range of internal Froude (Fr) and Reynolds (Re) numbers. For DNS the Splitting on physical factors Method for Incompressible Fluid flows (SMIF) with the hybrid explicit finite difference scheme (second-order accuracy in space, minimum scheme viscosity and dispersion, monotonous) has been used. At Fr > 10 with increasing of Re we observed the flow regimes of the homogeneous viscous fluid (including the laminar-turbulent transition in the boundary layer on the sphere). With decreasing of Fr at Re < 500 the strong transformation of vortex structures in the sphere wake is demonstrated by means of the β – visualization. Thus the refined classification of the flow regimes around a sphere moving in the viscous stratified fluid is presented.

  17. Quantitative assessment of image motion blur in diffraction images of moving biological cells

    Science.gov (United States)

    Wang, He; Jin, Changrong; Feng, Yuanming; Qi, Dandan; Sa, Yu; Hu, Xin-Hua

    2016-02-01

    Motion blur (MB) presents a significant challenge for obtaining high-contrast image data from biological cells with a polarization diffraction imaging flow cytometry (p-DIFC) method. A new p-DIFC experimental system has been developed to evaluate the MB and its effect on image analysis using a time-delay-integration (TDI) CCD camera. Diffraction images of MCF-7 and K562 cells have been acquired with different speed-mismatch ratios and compared to characterize MB quantitatively. Frequency analysis of the diffraction images shows that the degree of MB can be quantified by bandwidth variations of the diffraction images along the motion direction. The analytical results were confirmed by the p-DIFC image data acquired at different speed-mismatch ratios and used to validate a method of numerical simulation of MB on blur-free diffraction images, which provides a useful tool to examine the blurring effect on diffraction images acquired from the same cell. These results provide insights on the dependence of diffraction image on MB and allow significant improvement on rapid biological cell assay with the p-DIFC method.

  18. A 3D GPU-accelerated MPI-parallel computational tool for simulating interaction of moving rigid bodies with two-fluid flows

    Science.gov (United States)

    Pathak, Ashish; Raessi, Mehdi

    2014-11-01

    We present a 3D MPI-parallel, GPU-accelerated computational tool that captures the interaction between a moving rigid body and two-fluid flows. Although the immediate application is the study of ocean wave energy converters (WECs), the model was developed at a general level and can be used in other applications. Solving the full Navier-Stokes equations, the model is able to capture non-linear effects, including wave-breaking and fluid-structure interaction, that have significant impact on WEC performance. To transport mass and momentum, we use a consistent scheme that can handle large density ratios (e.g. air/water). We present a novel reconstruction scheme for resolving three-phase (solid-liquid-gas) cells in the volume-of-fluid context, where the fluid interface orientation is estimated via a minimization procedure, while imposing a contact angle. The reconstruction allows for accurate mass and momentum transport in the vicinity of three-phase cells. The fast-fictitious-domain method is used for capturing the interaction between a moving rigid body and two-fluid flow. The pressure Poisson solver is accelerated using GPUs in the MPI framework. We present results of an array of test cases devised to assess the performance and accuracy of the computational tool.

  19. Analytical methods for vancomycin determination in biological fluids and in pharmaceuticals

    Directory of Open Access Journals (Sweden)

    Marta Maria Duarte Carvalho Vila

    2007-04-01

    Full Text Available Vancomycin is a glycopeptide antibiotic employed in the treatment of infections caused by certain methicillin-resistant staphylococci. It is indicated also for patients allergic to penicillin or when there is no response to penicillins or cephalosporins. The adequate vancomycin concentration levels in blood serum lies between 5 and 10 mg/L. Higher values are toxic, causing mainly nephrotoxicity and ototoxicity. Various analytical methods are described in the literature: spectrophotometric, immunologic, biologic and chromatographic methods. This paper reviews the main analytical methods for vancomycin determination in biological fluids and in pharmaceutical preparations.

  20. Direct Deposition of Gas Phase Generated Aerosol Gold Nanoparticles into Biological Fluids - Corona Formation and Particle Size Shifts

    Science.gov (United States)

    Svensson, Christian R.; Messing, Maria E.; Lundqvist, Martin; Schollin, Alexander; Deppert, Knut; Pagels, Joakim H.; Rissler, Jenny; Cedervall, Tommy

    2013-01-01

    An ongoing discussion whether traditional toxicological methods are sufficient to evaluate the risks associated with nanoparticle inhalation has led to the emergence of Air-Liquid interface toxicology. As a step in this process, this study explores the evolution of particle characteristics as they move from the airborne state into physiological solution. Airborne gold nanoparticles (AuNP) are generated using an evaporation-condensation technique. Spherical and agglomerate AuNPs are deposited into physiological solutions of increasing biological complexity. The AuNP size is characterized in air as mobility diameter and in liquid as hydrodynamic diameter. AuNP:Protein aggregation in physiological solutions is determined using dynamic light scattering, particle tracking analysis, and UV absorption spectroscopy. AuNPs deposited into homocysteine buffer form large gold-aggregates. Spherical AuNPs deposited in solutions of albumin were trapped at the Air-Liquid interface but was readily suspended in the solutions with a size close to that of the airborne particles, indicating that AuNP:Protein complex formation is promoted. Deposition into serum and lung fluid resulted in larger complexes, reflecting the formation of a more complex protein corona. UV absorption spectroscopy indicated no further aggregation of the AuNPs after deposition in solution. The corona of the deposited AuNPs shows differences compared to AuNPs generated in suspension. Deposition of AuNPs from the aerosol phase into biological fluids offers a method to study the protein corona formed, upon inhalation and deposition in the lungs in a more realistic way compared to particle liquid suspensions. This is important since the protein corona together with key particle properties (e.g. size, shape and surface reactivity) to a large extent may determine the nanoparticle effects and possible translocation to other organs. PMID:24086363

  1. Templating effect in DNA proximity ligation enables use of non-bioorthogonal chemistry in biological fluids

    OpenAIRE

    Spiropulos, Nicholas G.; Heemstra, Jennifer M.

    2012-01-01

    Here we describe the first example of selective reductive amination in biological fluids using split aptamer proximity ligation (StAPL). Utilizing the cocaine split aptamer, we demonstrate small-molecule-dependent ligation that is dose-dependent over a wide range of target concentrations in buffer, human blood serum and artificial urine medium. We explore the substrate binding preferences of the split aptamer and find that the cinchona alkaloids quinine and quinidine bind to the aptamer with ...

  2. Banking of biological fluids for studies of disease-associated protein biomarkers

    DEFF Research Database (Denmark)

    Rasmussen, Anne-Sofie Schrohl; Würtz, Sidse Ørnbjerg; Kohn, Elise;

    2008-01-01

    biological fluids, especially serum and plasma, intended for study of protein biomarkers. In biomarker studies the process from the decision to take a sample from an individual to the moment the sample is safely placed in the biobank consists of several phases including collection of samples, transport of...... biobank as well as conclusions and clinical recommendations based on analysis of such material may be severely affected....

  3. A fictitious domain finite element method for simulations of fluid-structure interactions: The Navier-Stokes equations coupled with a moving solid

    OpenAIRE

    Court, Sébastien; Fournié, Michel

    2015-01-01

    The paper extends a stabilized fictitious domain finite element method initially developed for the Stokes problem to the incompressible Navier-Stokes equations coupled with a moving solid. This method presents the advantage to predict an optimal approximation of the normal stress tensor at the interface. The dynamics of the solid is governed by the Newton's laws and the interface between the fluid and the structure is materialized by a level-set which cuts the elements of the mesh. An algorit...

  4. Treatment of waste metalworking fluid by a hybrid ozone-biological process.

    Science.gov (United States)

    Jagadevan, Sheeja; Graham, Nigel J; Thompson, Ian P

    2013-01-15

    In metal machining processes, the regulation of heat generation and lubrication at the contact point are achieved by application of a fluid referred to as metalworking fluid (MWF). MWFs inevitably become operationally exhausted with age and intensive use, which leads to compromised properties, thereby necessitating their safe disposal. Disposal of this waste through a biological route is an increasingly attractive option, since it is effective with relatively low energy demands. However, successful biological treatment is challenging since MWFs are chemically complex, and include biocides specifically to retard microbial deterioration whilst the fluids are operational. In this study remediation of the recalcitrant component of a semi-synthetic MWF by a novel hybrid ozone-bacteriological treatment, was investigated. The hybrid treatment proved to be effective and reduced the chemical oxygen demand by 72% (26.9% and 44.9% reduction after ozonation and biological oxidation respectively). Furthermore, a near-complete degradation of three non-biodegradable compounds (viz. benzotriazole, monoethanolamine, triethanolamine), commonly added as biocides and corrosion inhibitors in MWF formulations, under ozonation was observed. PMID:23274939

  5. FROM THE CURRENT LITERATURE: Mechanisms and models of the dehydration self-organization in biological fluids

    Science.gov (United States)

    Tarasevich, Yurii Yu

    2004-07-01

    The dehydration self-organization phenomenon in biological fluids attracted the attention of researchers slightly more than a decade ago. While seemingly simple (the structure formation is possible to observe even in domestic conditions), the effect turned out to be extremely complicated and to involve a number of interrelated processes of a different physical nature. The dehydration self-organization effect in biological fluids underlies a medical diagnostic technique patented in 40 countries of the world, while the mechanisms that underlie the technique still remain largely obscure. This review is an attempt to draw an integrated picture of the current state of the problem: to emphasize reliably established facts and the problems that remain to be solved, to put an end to speculation, and to characterize the available theories and models. An analysis of the literature sources allows us to draw the conclusion that the effects observed in the dehydration of biological fluids are typical for colloidal solutions in general and can be described in the framework of conventional physical approaches.

  6. Hydrodynamics and convection enhanced macromolecular fluid transport in soft biological tissues: Application to solid tumor.

    Science.gov (United States)

    Dey, Bibaswan; Sekhar, G P Raja

    2016-04-21

    This work addresses a theoretical framework for transvascular exchange and extravascular transport of solute macromolecules through soft interstitial space inside a solid tumor. Most of the soft biological tissues show materialistic properties similar to deformable porous material. They exhibit mechanical behavior towards the fluid motion since the solid phase of the tumor tissue gets compressed by the drag force that is associated with the extracellular fluid flow. This paper presents a general view about the transvascular and interstitial transport of solute nutrients inside a tumor in the macroscopic level. Modified Starling׳s equation is used to describe transvascular nutrient transport. On the macroscopic level, motion of extracellular fluid within the tumor interstitium is modeled with the help of biphasic mixture theory and a spherical symmetry solution is given as a simpler case. This present model describes the average interstitial fluid pressure (IFP), extracellular fluid velocity (EFV) and flow rate of extracellular fluid, as well as the deformation of the solid phase of the tumor tissue as an immediate cause of extracellular fluid flow. When the interstitial transport is diffusion dominated, an analytical treatment of advection-diffusion-reaction equation finds the overall nutrient distribution. We propose suitable criteria for the formation of necrosis within the tumor interstitium. This study introduces some parameters that represent the nutrient supply from tumor blood vessels into the tumor extracellular space. These transport parameters compete with the reversible nutrient metabolism of the tumor cells present in the interstitium. The present study also shows that the effectiveness factor corresponding to a first order nutrient metabolism may reach beyond unity if the strength of the distributive solute source assumes positive non-zero values. PMID:26851443

  7. Enzyme Biosensors for Biomedical Applications: Strategies for Safeguarding Analytical Performances in Biological Fluids.

    Science.gov (United States)

    Rocchitta, Gaia; Spanu, Angela; Babudieri, Sergio; Latte, Gavinella; Madeddu, Giordano; Galleri, Grazia; Nuvoli, Susanna; Bagella, Paola; Demartis, Maria Ilaria; Fiore, Vito; Manetti, Roberto; Serra, Pier Andrea

    2016-01-01

    Enzyme-based chemical biosensors are based on biological recognition. In order to operate, the enzymes must be available to catalyze a specific biochemical reaction and be stable under the normal operating conditions of the biosensor. Design of biosensors is based on knowledge about the target analyte, as well as the complexity of the matrix in which the analyte has to be quantified. This article reviews the problems resulting from the interaction of enzyme-based amperometric biosensors with complex biological matrices containing the target analyte(s). One of the most challenging disadvantages of amperometric enzyme-based biosensor detection is signal reduction from fouling agents and interference from chemicals present in the sample matrix. This article, therefore, investigates the principles of functioning of enzymatic biosensors, their analytical performance over time and the strategies used to optimize their performance. Moreover, the composition of biological fluids as a function of their interaction with biosensing will be presented. PMID:27249001

  8. Bions: a family of biomimetic mineralo-organic complexes derived from biological fluids.

    Directory of Open Access Journals (Sweden)

    Cheng-Yeu Wu

    Full Text Available Mineralo-organic nanoparticles form spontaneously in human body fluids when the concentrations of calcium and phosphate ions exceed saturation. We have shown previously that these mineralo-organic nanoparticles possess biomimetic properties and can reproduce the whole phenomenology of the so-called nanobacteria-mineralized entities initially described as the smallest microorganisms on earth. Here, we examine the possibility that various charged elements and ions may form mineral nanoparticles with similar properties in biological fluids. Remarkably, all the elements tested, including sodium, magnesium, aluminum, calcium, manganese, iron, cobalt, nickel, copper, zinc, strontium, and barium form mineralo-organic particles with bacteria-like morphologies and other complex shapes following precipitation with phosphate in body fluids. Upon formation, these mineralo-organic particles, which we term bions, invariably accumulate carbonate apatite during incubation in biological fluids; yet, the particles also incorporate additional elements and thus reflect the ionic milieu in which they form. Bions initially harbor an amorphous mineral phase that gradually converts to crystals in culture. Our results show that serum produces a dual inhibition-seeding effect on bion formation. Using a comprehensive proteomic analysis, we identify a wide range of proteins that bind to these mineral particles during incubation in medium containing serum. The two main binding proteins identified, albumin and fetuin-A, act as both inhibitors and seeders of bions in culture. Notably, bions possess several biomimetic properties, including the possibility to increase in size and number and to be sub-cultured in fresh culture medium. Based on these results, we propose that bions represent biological, mineralo-organic particles that may form in the body under both physiological and pathological homeostasis conditions. These mineralo-organic particles may be part of a

  9. Experimental evaluation of drag force, drag torque, and magnus force acting on a rotating particle moving in fluid

    Czech Academy of Sciences Publication Activity Database

    Vlasák, Pavel; Chára, Zdeněk; Kysela, Bohuš

    New York : ASME, 2013, V01CT20A012. ISBN 978-0-7918-5556-0. [ASME Fluids Engineering Division Summer Meeting. Nevada (US), 07.07.2013-11.07.2013] R&D Projects: GA ČR GA103/09/1718 Institutional support: RVO:67985874 Keywords : drag force * drag torque * magnus force * Reynolds numbers Subject RIV: BK - Fluid Dynamics

  10. Hybrid biological, electron beam and zero-valent nano iron treatment of recalcitrant metalworking fluids.

    Science.gov (United States)

    Thill, Patrick G; Ager, Duane K; Vojnovic, Borivoj; Tesh, Sarah J; Scott, Thomas B; Thompson, Ian P

    2016-04-15

    Hybrid approaches for the remediation and detoxification of toxic recalcitrant industrial wastewater were investigated. The focus was waste metalworking fluid, which was selected as a representative model of other waste streams that are toxic, recalcitrant and that require more sustainable routes of safe disposal. The hybrid approaches included biodegradation, electron beam irradiation and zero-valent nano iron advanced oxidation processes that were employed individually and in sequence employing a factorial design. To compare process performance operationally exhausted and pristine metalworking fluid were compared. Sequential hybrid electron beam irradiation, biological, nanoscale zero-valent iron and biological treatment lead to synergistic detoxification and degradation of both recalcitrant streams, as determined by complementary surrogates and lead to overall improved COD removal of 92.8 ± 1.4% up from 85.9 ± 3.4% for the pristine metalworking fluid. Electron beam pre-treatment enabled more effective biotreatment, achieving 69.5 ± 8% (p = 0.005) and 24.6 ± 4.8% (p = 0.044) COD reductions. PMID:26905800

  11. A 3D, fully Eulerian, VOF-based solver to study the interaction between two fluids and moving rigid bodies using the fictitious domain method

    Science.gov (United States)

    Pathak, Ashish; Raessi, Mehdi

    2016-04-01

    We present a three-dimensional (3D) and fully Eulerian approach to capturing the interaction between two fluids and moving rigid structures by using the fictitious domain and volume-of-fluid (VOF) methods. The solid bodies can have arbitrarily complex geometry and can pierce the fluid-fluid interface, forming contact lines. The three-phase interfaces are resolved and reconstructed by using a VOF-based methodology. Then, a consistent scheme is employed for transporting mass and momentum, allowing for simulations of three-phase flows of large density ratios. The Eulerian approach significantly simplifies numerical resolution of the kinematics of rigid bodies of complex geometry and with six degrees of freedom. The fluid-structure interaction (FSI) is computed using the fictitious domain method. The methodology was developed in a message passing interface (MPI) parallel framework accelerated with graphics processing units (GPUs). The computationally intensive solution of the pressure Poisson equation is ported to GPUs, while the remaining calculations are performed on CPUs. The performance and accuracy of the methodology are assessed using an array of test cases, focusing individually on the flow solver and the FSI in surface-piercing configurations. Finally, an application of the proposed methodology in simulations of the ocean wave energy converters is presented.

  12. Generation of stationary and moving vortices in active polar fluids in the planar Taylor-Couette geometry.

    Science.gov (United States)

    Neef, M; Kruse, K

    2014-11-01

    We study the dynamics of an active polar fluid in the interstitial space between two fixed coaxial cylinders. For sufficiently large expansive or contractive active stresses, the fluid presents roll instabilities of axially symmetric states leading to the spontaneous formation of vortices in the flow field. These vortices are either stationary or travel around the inner cylinder. Increasing the activity further, our numerical solutions indicate the existence of active turbulence that coexists with regular vortex solutions. PMID:25493812

  13. Quantitation of methadone in biological fluids using deuterium labeled internal standards

    International Nuclear Information System (INIS)

    Deuterium labeled methadone which contained five 2H atoms in one aromatic ring was synthesized for use as an internal standard for quantitation of methadone in biological fluids. The method can measure plasma and urine levels of methadone down to 5 ng/ml. Plasma methadone levels were measured in several patients undergoing methadone maintenance therapy. Plasma levels generally fall between 100 and 400 ng/ml at an oral dose of 1 mg/kg. The half-life of methadone is estimated at 28.8 +- 4.8 hours and the volume of distribution is 312 liters

  14. Electromembrane extraction as a rapid and selective miniaturized sample preparation technique for biological fluids

    DEFF Research Database (Denmark)

    Gjelstad, Astrid; Pedersen-Bjergaard, Stig; Seip, Knut Fredrik

    2015-01-01

    organic solvent, and into an aqueous receiver solution. The extraction is promoted by application of an electrical field, causing electrokinetic migration of the charged analytes. The method has shown to perform excellent clean-up and selectivity from complicated aqueous matrices like biological fluids......This special report discusses the sample preparation method electromembrane extraction, which was introduced in 2006 as a rapid and selective miniaturized extraction method. The extraction principle is based on isolation of charged analytes extracted from an aqueous sample, across a thin film of....... Technical aspects of electromembrane extraction, important extraction parameters as well as a handful of examples of applications from different biological samples and bioanalytical areas are discussed in the paper....

  15. DeepPIV: Measuring in situ Biological-Fluid Interactions from the Surface to Benthos

    Science.gov (United States)

    Katija, K.; Sherman, A.; Graves, D.; Kecy, C. D.; Klimov, D.; Robison, B. H.

    2015-12-01

    The midwater region of the ocean (below the euphotic zone and above the benthos) is one of the largest ecosystems on our planet, yet it remains one of the least explored. Little known marine organisms that inhabit midwater have developed strategies for swimming and feeding that ultimately contributes to their evolutionary success, and may inspire engineering solutions for societally relevant challenges. Fluid mechanics governs the interactions that midwater organisms have with their physical environment, but limited access to midwater depths and lack of non-invasive methods to measure in situ small-scale fluid motions prevent these interactions from being better understood. Significant advances in underwater vehicle technologies have only recently improved access to midwater. Unfortunately, in situ small-scale fluid mechanics measurement methods are still lacking in the oceanographic community. Here we present DeepPIV, an instrumentation package that can be affixed to remotely operated underwater vehicles that quantifies small-scale fluid motions from the surface of the ocean down to 4000 m depths. Utilizing ambient, suspended particulate in the coastal regions of Monterey Bay, fluid-structure interactions are evaluated on a range of marine organisms in midwater. Initial science targets include larvaceans, biological equivalents of flapping flexible foils, that create mucus houses to filter food. Little is known about the structure of these mucus houses and the function they play in selectively filtering particles, and these dynamics can serve as particle-mucus models for human health. Using DeepPIV, we reveal the complex structures and flows generated within larvacean mucus houses, and elucidate how these structures function.

  16. The Balance of Fluid and Osmotic Pressures across Active Biological Membranes with Application to the Corneal Endothelium.

    Science.gov (United States)

    Cheng, Xi; Pinsky, Peter M

    2015-01-01

    The movement of fluid and solutes across biological membranes facilitates the transport of nutrients for living organisms and maintains the fluid and osmotic pressures in biological systems. Understanding the pressure balances across membranes is crucial for studying fluid and electrolyte homeostasis in living systems, and is an area of active research. In this study, a set of enhanced Kedem-Katchalsky (KK) equations is proposed to describe fluxes of water and solutes across biological membranes, and is applied to analyze the relationship between fluid and osmotic pressures, accounting for active transport mechanisms that propel substances against their concentration gradients and for fixed charges that alter ionic distributions in separated environments. The equilibrium analysis demonstrates that the proposed theory recovers the Donnan osmotic pressure and can predict the correct fluid pressure difference across membranes, a result which cannot be achieved by existing KK theories due to the neglect of fixed charges. The steady-state analysis on active membranes suggests a new pressure mechanism which balances the fluid pressure together with the osmotic pressure. The source of this pressure arises from active ionic fluxes and from interactions between solvent and solutes in membrane transport. We apply the proposed theory to study the transendothelial fluid pressure in the in vivo cornea, which is a crucial factor maintaining the hydration and transparency of the tissue. The results show the importance of the proposed pressure mechanism in mediating stromal fluid pressure and provide a new interpretation of the pressure modulation mechanism in the in vivo cornea. PMID:26719894

  17. The Balance of Fluid and Osmotic Pressures across Active Biological Membranes with Application to the Corneal Endothelium.

    Directory of Open Access Journals (Sweden)

    Xi Cheng

    Full Text Available The movement of fluid and solutes across biological membranes facilitates the transport of nutrients for living organisms and maintains the fluid and osmotic pressures in biological systems. Understanding the pressure balances across membranes is crucial for studying fluid and electrolyte homeostasis in living systems, and is an area of active research. In this study, a set of enhanced Kedem-Katchalsky (KK equations is proposed to describe fluxes of water and solutes across biological membranes, and is applied to analyze the relationship between fluid and osmotic pressures, accounting for active transport mechanisms that propel substances against their concentration gradients and for fixed charges that alter ionic distributions in separated environments. The equilibrium analysis demonstrates that the proposed theory recovers the Donnan osmotic pressure and can predict the correct fluid pressure difference across membranes, a result which cannot be achieved by existing KK theories due to the neglect of fixed charges. The steady-state analysis on active membranes suggests a new pressure mechanism which balances the fluid pressure together with the osmotic pressure. The source of this pressure arises from active ionic fluxes and from interactions between solvent and solutes in membrane transport. We apply the proposed theory to study the transendothelial fluid pressure in the in vivo cornea, which is a crucial factor maintaining the hydration and transparency of the tissue. The results show the importance of the proposed pressure mechanism in mediating stromal fluid pressure and provide a new interpretation of the pressure modulation mechanism in the in vivo cornea.

  18. Optimized and validated spectrophotometric methods for the determination of nicorandil in drug formulations and biological fluids.

    Science.gov (United States)

    Rahman, Nafisur; Ahmad Khan, Nadeem; Hejaz Azmi, Syed Najmul

    2004-07-01

    Two simple, sensitive and economical spectrophotometric methods have been developed for the determination of nicorandil in drug formulations and biological fluids. Method A is based on the reaction of the drug with brucine-sulphanilic acid reagent in sulphuric acid medium producing a yellow-coloured product, which absorbs maximally at 410 nm. Method B depends on the formation of the intensely blue-coloured product which results due to the interaction of an electrophilic intermediate of 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH) with oxidized product of 4-(methyl amino) phenol sulphate (metol) in the presence of nicorandil as an oxidizing agent in sulphuric acid medium. The coloured product shows absorbance maximum at 560 nm. Under the optimized experimental conditions, Beer's law is obeyed in the concentration range of 2.5-35.0 and 0.40-2.2 microg ml(-1) for Methods A and B, respectively. Both the methods have been successfully applied to the determination of nicorandil in drug formulations and biological fluids. The results are validated statistically and through recovery studies. In order to establish the bias and the performance of the proposed methods, the point and interval hypothesis tests have been performed. The experimental true bias of all samples is smaller than +/-2%. PMID:15231427

  19. Amplification without instability: applying fluid dynamical insights in chemistry and biology

    International Nuclear Information System (INIS)

    While amplification of small perturbations often arises from instability, transient amplification is possible locally even in asymptotically stable systems. That is, knowledge of a system's stability properties can mislead one's intuition for its transient behaviors. This insight, which has an interesting history in fluid dynamics, has more recently been rediscovered in ecology. Surprisingly, many nonlinear fluid dynamical and ecological systems share linear features associated with transient amplification of noise. This paper aims to establish that these features are widespread in many other disciplines concerned with noisy systems, especially chemistry, cell biology and molecular biology. Here, using classic nonlinear systems and the graphical language of network science, we explore how the noise amplification problem can be reframed in terms of activatory and inhibitory interactions between dynamical variables. The interaction patterns considered here are found in a great variety of systems, ranging from autocatalytic reactions and activator–inhibitor systems to influential models of nerve conduction, glycolysis, cell signaling and circadian rhythms. (paper)

  20. Methotrexate concentrations in biological fluids: Comparison of results obtained by radioimmunoassay and direct ligand binding radioassay

    International Nuclear Information System (INIS)

    A sensitive (sensitivity 2.2 x 10-9 mol/l) and specific (practically no cross-reaction with circulating folates) radioimmunoassay for the determination of methotrexate concentrations in biological fluids is described and compared with a commercial competitive protein binding assay. Antiserum with high titer was produced in rabbits immunized with MTX-human serum albumin conjugate. Fitness for use in pharmacokinetic drug level determinations was shown in three patients, who received both low doses and high dose therapy combined with citrovorum factor rescue. An excellent correlation was found between plasma and urine MTX concentrations obtained by RIA and competitive protein binding assay. A two-compartment pharmacokinetic model was found adequately describing the serum decay curves, but there was a great interindividual variability in the calculated pharmacokinetic parameters. (author)

  1. Plastic bumetanide membrane sensor and its applications in pharmaceutical preparations and biological fluids

    International Nuclear Information System (INIS)

    A novel plastic poly (vinyl chloride) membrane electrode based on bumetanide-tungstophosphate ion association as electroactive material for the determination of bumetanide in pure form, pharmaceutical formulation and biological fluids is developed in which the plasticizer is di-butyl sebacate. The linear response covers the range of 1x10 (power-6) -1x10 (power-3) M drug concentration with a slope of 58.5mV/decade. The practical pH range is 5-8. Interferences from common cations, alkaloids and drug excipients are reported. The proposed electrode has been successfully applied to determine bumetanide in pure form and the content uniformity for tablets. The results are correlated well with those obtained by the official USP 25, NF 20 method. (author)

  2. Micro-PIXE characterization of interactions between a sol-gel derived bioactive glass and biological fluids

    OpenAIRE

    Lao, Jonathan; Nedelec, Jean-Marie; Moretto,Philippe; Jallot, Edouard

    2006-01-01

    Bioactive glasses possess the ability to bond to living tissues through the formation of a calcium phosphate-rich layer at their interface with living tissues. This paper reports the different steps of this bioactivity process via a complete micro-PIXE characterization of a sol-gel derived SiO2-CaO bioactive glass in contact with biological fluids for different delays. Multi-elemental cartography at the glass/biological fluids interface together with major and trace elements quantification pe...

  3. Structuring Characteristics of Biological Fluids of Patients with Combined Cardiovascular and Gastrointestinal Pathology

    Directory of Open Access Journals (Sweden)

    Simonova Zh.G.

    2014-09-01

    Full Text Available The aim of the investigation was a comparative study of the result of self- and initiated crystallization of saliva and urine in patients with an isolated ulcer disease, coronary heart disease (CHD, and the combination of both. Materials and Methods. We studied saliva and urine samplings in 35 patients with isolated CHD, in 48 — with ulcer disease, and in 112 — with the combination of both. CHD was diagnosed based on a clinical study, as well as according to the findings of instrumental studies (ECG recording at rest and physical load, Holter ECG monitoring, echocardiography. The diagnosis of ulcer disease was verified by fibrogastroduodenoscopy; helicobacteriosis was revealed by biopsy and serologic testing. The characteristics of self- and initiated crystallization of biological substrates were assessed using a semiquantitative analysis. Normal saline was a basic substance for teziography. Results. A combined pathology was found to have a specific character in the formation of crystallogenic properties of biological fluid facies of patients. This fact is consistent with the data indicating dysmetabolic disorders, which integrate the diseases under study and are caused by Helicobacter pylori. The findings both confirm the presence of metabolic response of the body on comorbidity and also can serve as the basis for the development of noninvasive technologies to monitor the effectiveness of Helicobacter pylori eradication.

  4. MHD Effects on Non-Newtonian Power-Law Fluid Past a Continuously Moving Porous Flat Plate with Heat Flux and Viscous Dissipation

    Science.gov (United States)

    Kishan, N.; Shashidar Reddy, B.

    2013-06-01

    The problem of a magneto-hydro dynamic flow and heat transfer to a non-Newtonian power-law fluid flow past a continuously moving flat porous plate in the presence of sucion/injection with heat flux by taking into consideration the viscous dissipation is analysed. The non-linear partial differential equations governing the flow and heat transfer are transformed into non-linear ordinary differential equations using appropriate transformations and then solved numerically by an implicit finite difference scheme. The solution is found to be dependent on various governing parameters including the magnetic field parameter M, power-law index n, suction/injection parameter ƒw, Prandtl number Pr and Eckert number Ec. A systematical study is carried out to illustrate the effects of these major parameters on the velocity profiles, temperature profile, skin friction coefficient and rate of heat transfer and the local Nusslet number.

  5. Effect of Viscous Dissipation on MHD Free Convection Flow Heat and Mass Transfer of Non-Newtonian Fluids along a Continuously Moving Stretching Sheet

    Directory of Open Access Journals (Sweden)

    K.C. Saha

    2015-04-01

    Full Text Available The effects of MHD free convection heat and mass transfer of power-law Non-Newtonian fluids along a stretching sheet with viscous dissipation has been analyzed. This has been done under the simultaneous action of suction, thermal radiation and uniform transverse magnetic field. The stretching sheet is assumed to continuously moving with a power-law velocity and maintaining a uniform surface heat-flux. The governing non-linear partial differential equations are transformed into non-linear ordinary differential equations, using appropriate similarity transformations and the resulting problem is solved numerically using Nachtsheim-Swigert shooting iteration technique along with sixth order Runge-Kutta integration scheme. A parametric study of the parameters arising in the problem such as the Eckert number due to viscous dissipation, radiation number, buoyancy parameter, Schmidt number, Prandtl number etc are studied and the obtained results are shown graphically and the physical aspects of the problem are discussed.

  6. Thermo-fluid-dynamics of turbulent boundary layer over a moving continuous flat sheet in a parallel free stream

    Science.gov (United States)

    Afzal, Bushra; Noor Afzal Team; Bushra Afzal Team

    2014-11-01

    The momentum and thermal turbulent boundary layers over a continuous moving sheet subjected to a free stream have been analyzed in two layers (inner wall and outer wake) theory at large Reynolds number. The present work is based on open Reynolds equations of momentum and heat transfer without any closure model say, like eddy viscosity or mixing length etc. The matching of inner and outer layers has been carried out by Izakson-Millikan-Kolmogorov hypothesis. The matching for velocity and temperature profiles yields the logarithmic laws and power laws in overlap region of inner and outer layers, along with friction factor and heat transfer laws. The uniformly valid solution for velocity, Reynolds shear stress, temperature and thermal Reynolds heat flux have been proposed by introducing the outer wake functions due to momentum and thermal boundary layers. The comparison with experimental data for velocity profile, temperature profile, skin friction and heat transfer are presented. In outer non-linear layers, the lowest order momentum and thermal boundary layer equations have also been analyses by using eddy viscosity closure model, and results are compared with experimental data. Retired Professor, Embassy Hotel, Rasal Ganj, Aligarh 202001 India.

  7. Progress in Computational Physics (PiCP) Vol 2 Coupled Fluid Flow in Energy, Biology and Environmental Research

    CERN Document Server

    Ehrhardt, Matthias

    2012-01-01

    This second volume contains both, the mathematical analysis of the coupling between fluid flow and porous media flow and state-of-the art numerical techniques, like tailor-made finite element and finite volume methods. Readers will come across articles devoted to concrete applications of these models in the field of energy, biology and environmental research.

  8. MHD Heat and Mass Transfer of Chemical Reaction Fluid Flow over a Moving Vertical Plate in Presence of Heat Source with Convective Surface Boundary Condition

    Directory of Open Access Journals (Sweden)

    B. R. Rout

    2013-01-01

    Full Text Available This paper aims to investigate the influence of chemical reaction and the combined effects of internal heat generation and a convective boundary condition on the laminar boundary layer MHD heat and mass transfer flow over a moving vertical flat plate. The lower surface of the plate is in contact with a hot fluid while the stream of cold fluid flows over the upper surface with heat source and chemical reaction. The basic equations governing the flow, heat transfer, and concentration are reduced to a set of ordinary differential equations by using appropriate transformation for variables and solved numerically by Runge-Kutta fourth-order integration scheme in association with shooting method. The effects of physical parameters on the velocity, temperature, and concentration profiles are illustrated graphically. A table recording the values of skin friction, heat transfer, and mass transfer at the plate is also presented. The discussion focuses on the physical interpretation of the results as well as their comparison with previous studies which shows good agreement as a special case of the problem.

  9. Use of charged particle beams for analysis of biological tissues and fluids

    International Nuclear Information System (INIS)

    PIXE has passed through its demonstration stage and matured into a viable tool supported by a reliable physics data base; the main problem to be solved at the outset of any new project is the preparation of a representative specimen of uniform thickness (or thinness) rather than any aspect of X-ray or accelerator physics or technology. The authors repeats the caution that minimum detection limits are strongly influenced by the nuclear reaction gamma-ray background from trace elements in the specimen. Thus experiment on a new target type is preferable to use of MDL calculations based on the background due to atomic processes (bremsstrahlung) in the known matrix. One hopes to see a more adventurous mood eg a move from routine blood serum analysis towards analyses of different blood fractions that concentrate specific trace elements. PIGE, while promising, must be regarded as developmental until the data-base of elemental gamma-ray yields is extended and made more accurate; work on fluorine in teeth clearly stands to profit from this technique. Finally, RBS, although scarcely used to date in any biological context, is clearly a powerful way of measuring major elemental ratios in mineralized tissues; however, RBS lacks the resolving power of PIXE and so is not a candidate for multi-trace element analysis

  10. Effects of Hall Current on Hydromagnetic Natural Convection Flow of a Heat Absorbing Fluid past an Impulsively Moving Vertical Plate with Ramped Temperature

    Directory of Open Access Journals (Sweden)

    Gauri Shanker Seth

    2012-08-01

    Full Text Available Effects of Hall current on unsteady MHD natural convection flow of a viscous, incompressible, electrically conducting and heat absorbing fluid past an impulsively moving vertical plate with ramped wall temperature in a porous medium, in the presence of thermal diffusion, is studied. The exact solution of momentum and energy equations, under Boussinesq approximation, is obtained in closed form by Laplace transform technique for both ramped temperature and isothermal plates. Solution is also obtained in the case of unit Prandtl number for both ramped temperature and isothermal plates. The expressions for skin friction due to primary and secondary flows and Nusselt number for both ramped temperature and isothermal plates are also derived. Mathematical formulation of the problem, in non-dimensional form, contains six pertinent flow parameters viz. M^2 (magnetic parameter, m (Hall current parameter Gr (Grashof number, K1 (permeability parameter, Pr (Prandtl number and Phi (heat absorption coefficient. The numerical values of primary and secondary fluid velocities are displayed graphically versus boundary layer coordinate y for various values of m, Gr, K1, Phi and t while that of fluid temperature are presented in graphical form versus y for different values of Pr, Phi and t for both ramped temperature and isothermal plates. For both ramped temperature and isothermal plates, the numerical values of skin friction due to primary and secondary flows are presented in tabular form for various values of m, Gr, K1, Phi and t whereas that of Nusselt number are given in tables for different values of Pr, Phi and t.

  11. BIO-PROGRAMMING PROSPECTS OF JAVA: A COMPUTATIONAL MOVE TOWARDS THE UNDERSTANDING OF THE BIOLOGICAL ASPECTS OF GENES AND PROTEINS

    Directory of Open Access Journals (Sweden)

    KALPANA RAJA

    2011-12-01

    Full Text Available Java is a powerful object oriented programming language that dominates many other programming languages for more than a decade. It is well designed and available as many executable technologies for software development such as Java Swing, Java Beans, Java Applets, Java Web Start, Java Database Connectivity (JDBC, Java Server Pages (JSP and Java 2 Enterprise Edition (J2EE. Beyond its usage in the IT sector, the language is prominent even in the new emerging fields including bioinformatics and computational biology.The biological data (genes and proteins from the biological and medical research is immense and require software professionals to mine them for new knowledge discovery. The knowledge to merge the programming concepts of Java to understand a wide range of biological concepts opens a new career challenge for many IT professionals. This paper introduces the implementation of the coding knowledge of Java in the field ofmolecular biology.

  12. Metabolism and toxicological analysis of synthetic cannabinoids in biological fluids and tissues.

    Science.gov (United States)

    Presley, B C; Gurney, S M R; Scott, K S; Kacinko, S L; Logan, B K

    2016-07-01

    Synthetic cannabinoids, which began proliferating in the United States in 2009, have gone through numerous iterations of modification to their chemical structures. More recent generations of compounds have been associated with significant adverse outcomes following use, including cognitive and psychomotor impairment, seizures, psychosis, tissue injury and death. These effects increase the urgency for forensic and public health laboratories to develop methods for the detection and identification of novel substances, and apply these to the determination of their metabolism and disposition in biological samples. This comprehensive review describes the history of the appearance of the drugs in the United States, discusses the naming conventions emerging to designate new structures, and describes the most prominent new compounds linked to the adverse effects now associated with their use. We review in depth the metabolic pathways that have been elucidated for the major members of each of the prevalent synthetic cannabinoid drug subclasses, the enzyme systems responsible for their metabolism, and the use of in silico approaches to assist in predicting and identifying the metabolites of novel compounds and drug subclasses that will continue to appear. Finally, we review and critique analytical methods applied to the detection of the drugs and their metabolites, including immunoassay screening, and liquid chromatography mass spectrometry confirmatory techniques applied to urine, serum, whole blood, oral fluid, hair, and tissues. PMID:27257717

  13. DEVELOPMENT OF TETRAZEPAM-SELECTIVE MEMBRANE SENSORS AND THEIR APPLICATIONS IN PHARMACEUTICAL PREPARATIONS AND BIOLOGICAL FLUIDS

    Directory of Open Access Journals (Sweden)

    MAHA EL-TOHAMY

    2010-06-01

    Full Text Available The construction and performance characteristics of tetrazepam selective electrodes were developed. Two types of electrodes: plastic membrane I and coated wire II were constructed based on the incorporation of tetrazepam with phosphomolybdic acid. The influence of membrane composition, kind of plasticizer, pH of the test solution, soaking time, and foreign ions on the electrodes were investigated. The electrodes showed a Nernstain response with a mean calibration graph slope of 58.88±0.5 and 59.18±0.1 mV decade-1 at 25ºC for electrode I and II respectively, over tetrazepam concentration range from 5x10-3-1x10-6M and 1x10-2-1x10-6M, and with detection limit 5.0x10-7 M and 4.8 x10-7M for electrode I and II respectively. The constructed electrodes gave average selective precise and usable within the pH range 4-6. Interferences from common cations, alkaloids, sugars, amino acids and drug excipients were reported. The results obtained by the proposed electrodes were also applied successfully to the determination of the drug in pharmaceutical preparations and biological fluids.

  14. Quantitative X-ray analysis of biological fluids: the microdroplet technique

    International Nuclear Information System (INIS)

    X-ray microanalysis can be used to quantitatively determine the elemental composition of microvolumes of biological fluids. This article describes the various steps in preparation of microdroplets for analysis: The manufacturing of micropipettes, the preparation of the specimen support, the deposition of droplets on the support, shock-freezing, and lyophilization. Examples of common artifacts (incomplete rehydration prior to freezing or partial rehydration after lyophilization) are demonstrated. Analysis can be carried out either by wavelength-dispersive analysis, which is the most sensitive method, or by energy-dispersive analysis, which is more commonly available. The minimum detectable concentration is 0.05 mmol.liter-1 for 0.1-nl samples analyzed by wavelength-dispersive spectrometry and 0.5-1 mmol.liter-1 for samples analyzed by energy-dispersive spectrometry. A major problem, especially in wavelength-dispersive analysis, where high beam currents are used, is radiation damage to the specimen; in particular chloride (but also other elements) can be lost. Quantitative analysis requires the use of standard solutions with elemental concentration in the same range as those present in the specimen

  15. Development and characterization of a radioimmunoassay to measure human tissue kallikrein in biological fluids

    International Nuclear Information System (INIS)

    A direct radioimmunoassay has been developed to measure tissue kallikrein in human biological fluids, including serum, plasma, urine, pancreatic juice and saliva. Purified kallikreins from human urine and human saliva were used to raise rabbit antibody and each labelled with Na125I for use in the radioimmunoassay. Comparison of the different antigen-antibody systems was then made. Bound and free enzyme were separated by a double-antibody technique. The usable range of the standard curve was from 2.5 to 100 μg kallikrein/1. The intra-assay coefficient of variation was 4.7%, the interassay coefficient of variation 8.9% and the recoveries of purified kallikrein added to the samples were 99.3, 96.0, 110.8 and 81.2% for urine, saliva, serum and plasma respectively. Parallel dilution curves were obtained for serum and plasma, as well as urine, saliva and pancreatic juice. Plasma anticoagulated with EDTA or heparin gave consistently lower values than serum, when measured in the radioimmunoassay. From eight different subjects plasma (EDTA) values were on average 50% lower than those of serum, and subsequent experiments revealed that treatment of blood with some anticoagulants, in particular heparin and EDTA, resulted in a marked reduction in measurable tissue kallikrein. (author)

  16. Eu(III)-Sensitized Luminescence Probe for Determination of Tolnaftate in Pharmaceuticals and Biological Fluids.

    Science.gov (United States)

    Alarfaj, Nawal A; El-Tohamy, Maha F

    2016-03-01

    A highly selective, sensitive, accurate, and reproducible luminescence procedure for determination of antifungal drug tolnaftate was developed. The introduced method was based on the formation of Europa Universalis III (Eu(III))-tolnaftate complex using sodium sulfite as a deoxygenated agent in the presence of acetate buffer (pH = 6) and micellar solution of anionic surfactant sodium dodecyl sulfate. The optimum conditions (effect of pH, buffer, surfactant, Eu(III), and sodium sulfite concentrations) for the luminescence signal were investigated and optimized. The luminescence signals were recorded at λex = 270 nm and λem = 460 nm. The method has a good linear response (0.2-130 μg/mL(-1)) between the luminescence intensity and the concentrations of the drug (r = 0.999), with a LOD 0.07 μg/mL(-1) and LOQ 0.2 μg/mL(-1). The luminescence signals of Eu (III)-tolnaftate-sodium dodecyl sulfate were found to be 200-fold more sensitive without the presence of micelle solution. The interferences of some additives, metals, amino acids, sugars, and other related pharmacological action drugs were examined and no interference was recorded. The proposed method was used for quick and simple determination of tolnaftate in its pharmaceuticals and biological fluids. PMID:26964843

  17. Electrochemically deposited and etched membranes with precisely sized micropores for biological fluids microfiltration

    International Nuclear Information System (INIS)

    This paper presents simple and economical, yet reliable techniques to fabricate a micro-fluidic filter for MEMS lab-on-chip (LoC) applications. The microporous filter is a crucial component in a MEMS LoC system. Microsized components and contaminants in biological fluids are selectively filtered using copper and silicon membranes with precisely controlled microsized pores. Two techniques were explored in microporous membrane fabrication, namely copper electroplating and electrochemical etching (ECE) of silicon. In the first technique, a copper membrane with evenly distributed micropores was fabricated by electroplating the copper layer on the silicon nitride membrane, which was later removed to leave the freestanding microporous membrane structure. The second approach involves the thinning of bulk silicon down to a few micrometers thick using KOH and etching the resulting silicon membrane in 5% HF by ECE to create micropores. Upon testing with nanoparticles of various sizes, it was observed that electroplated copper membrane passes nanoparticles up to 200 nm wide, while porous silicon membrane passes nanoparticles up to 380 nm in size. Due to process compatibility, simplicity, and low-cost fabrication, electroplated copper and porous silicon membranes enable synchronized microfilter fabrication and integration into the MEMS LoC system. (paper)

  18. Templating effect in DNA proximity ligation enables use of non-bioorthogonal chemistry in biological fluids.

    Science.gov (United States)

    Spiropulos, Nicholas G; Heemstra, Jennifer M

    2012-07-01

    Here we describe the first example of selective reductive amination in biological fluids using split aptamer proximity ligation (StAPL). Utilizing the cocaine split aptamer, we demonstrate small-molecule-dependent ligation that is dose-dependent over a wide range of target concentrations in buffer, human blood serum and artificial urine medium. We explore the substrate binding preferences of the split aptamer and find that the cinchona alkaloids quinine and quinidine bind to the aptamer with higher affinity than cocaine. This increased affinity leads to improved detection limits for these small-molecule targets. We also demonstrate that linker length and hydrophobicity impact the efficiency of split aptamer ligation. The ability to carry out selective chemical transformations using non-bioorthogonal chemistry in media where competing reactive groups are present highlights the power of the increased effective molarity provided by DNA assembly. Obviating the need for bioorthogonal chemistry would dramatically expand the repertoire of chemical transformations available for use in templated reactions such as proximity ligation assays, in turn enabling the development of novel methods for biomolecule detection. PMID:23370267

  19. Gas/liquid chromatographic analysis of pemoline in biological fluids using electron capture detection.

    Science.gov (United States)

    Igwe, O J; Blake, J W

    1981-12-01

    An analytical gas/liquid chromatographic (GLC) protocol is described for the quantitation of pemoline in biological fluids of the horse. Plasma samples containing known quantities of pemoline and its analog as an internal standard (IS) were deproteinized with 5-sulfosalicylic acid, heated at 80 degree C, and centrifuged. 5-Phenyl-2,4-oxazolidinedione, the hydrolytic product of pemoline in acid medium, was extracted with dichloromethane (DCM). The organic layer was in turn re-extracted with 1% NaHCO3. The aqueous layer was acidified with HCI, and re-extracted with DCM, which was evaporated to dryness. The resulting residue was methylated with ethereal diazomethane. The methylated dione was dissolved in benzene, and analyzed with a gas/liquid chromatograph equipped with a tritiated scandium foil (Sc3H) electron capture detector (ECD). Urine samples to which pemoline was added were hydrolyzed with hydrochloric acid and carried through the analytical procedure in a manner similar to the plasma, except that the urine was further washed with lead acetate solution prior to the sodium bicarbonate extraction. The lower limits of detection were found to be 0.05 microgram/ml for plasma and 0.1 microgram/ml for urine when 1.0 ml of sample was used. This procedure can be used for pemoline detection control in international sporting events. PMID:7328158

  20. Evaluation of the solubility of the HPMC: PVA blends in biological fluids in vitro

    Directory of Open Access Journals (Sweden)

    Sara Elis Bianchi

    2011-01-01

    Full Text Available Polymers are often used to coat tablets for controlled drug release. The purpose of this study is to evaluate the solubility of the HPMC and PVA blend compared to isolated polymers in solutions with a pH of biological fluids (6 and 1.2 and the dissolution of capsules obtained using theophylline granules produced with the HPMC/PVA 25/75 blend as a matrix and as coating. HPMC is completely solubilized in the medium that simulates the pH of the stomach and intestine, and PVA is the polymer that allows controlling the solubility of the blend in the medium, with a differents pH. The dissolution time was monitored by UV absorbance with maximum theophylline at 269 nm. The theophylline was released immediately in the granules, and in the capsules 78.4% after 30 minutes and 97.4%, after 120 minutes. Thus, PVA can potentially control the drug solubilization, contributing to obtaining modified release systems.

  1. A nanofluidic bioarray chip for fast and high-throughput detection of antibodies in biological fluids

    Science.gov (United States)

    Lee, Jonathan; Gulzar, Naveed; Scott, Jamie K.; Li, Paul C. H.

    2012-10-01

    Immunoassays have become a standard in secretome analysis in clinical and research analysis. In this field there is a need for a high throughput method that uses low sample volumes. Microfluidics and nanofluidics have been developed for this purpose. Our lab has developed a nanofluidic bioarray (NBA) chip with the goal being a high throughput system that assays low sample volumes against multiple probes. A combination of horizontal and vertical channels are produced to create an array antigens on the surface of the NBA chip in one dimension that is probed by flowing in the other dimension antibodies from biological fluids. We have tested the NBA chip by immobilizing streptavidin and then biotinylated peptide to detect the presence of a mouse monoclonal antibody (MAb) that is specific for the peptide. Bound antibody is detected by an AlexaFluor 647 labeled goat (anti-mouse IgG) polyclonal antibody. Using the NBA chip, we have successfully detected peptide binding by small-volume (0.5 μl) samples containing 50 attomoles (100 pM) MAb.

  2. A simple kinetic spectrophotometric method for the determination of oxamniquine in formulations and spiked biological fluids.

    Science.gov (United States)

    Rizk, M; Belal, F; Ibrahim, F; Ahmed, S M; El-Enany, N M

    2000-08-15

    A simple and sensitive kinetic method for the determination of oxamniquine in pharmaceutical preparations and biological fluids was developed. The procedure is based upon a kinetic investigation of the oxidation reaction of the drug with alkaline potassium permanganate at room temperature for a fixed time of 20 min. The absorbance of the colored manganate ions was measured at 610 nm. Alternatively, the decrease in the absorbance of potassium permanganate after addition of the drug was measured at 525 nm. The absorbance concentration plots in both procedures were rectilinear over the range 0.5-4 microg ml(-1). The concentration of oxamniquine is calculated using the corresponding calibration equation for the fixed-time method. The determination of oxamniquine by fixed-concentration and rate-constant methods was feasible with the calibration equations obtained but the fixed time method had been found to be more applicable. Both procedures were applied to the determination of oxamniquine in formulations. The results obtained were in good agreement with those obtained using the official method. The fixed time method of 20 min was further applied to spiked human urine and plasma, the recoveries (%) were 100.94 +/- 0.57 and 98.07 +/- 0.88 for urine and plasma, respectively, at 610 nm, and 97.51 +/- 1.27 and 95.69 +/- 1.23 for urine and plasma, respectively, at 525 nm. PMID:10933544

  3. 运动界面追踪的CVOFLS方法∗%A Coupled Volume of Fluid and Level Set (CVOFLS) Method for Tracking Moving Interfaces

    Institute of Scientific and Technical Information of China (English)

    周文; 欧阳洁; 崔立营

    2015-01-01

    A new coupled volume of fluid and level set (CVOFLS) method is proposed to capture the moving interface, in order to improve both the inaccurate evaluation of the interface normal vector in volume of fluid (VOF) method and the poor mass conservation ability in level set (LS) method. The method takes the advantages of the VOF method and the LS method. At each time step, the LS equation is solved at first, and the interface normal vector is evaluated via the LS signed distance function. Then the VOF equation is evaluated, and the interface reconstruction and the mass correction are performed by the volume fraction. The method is applied in some benchmark cases, such as rotation of the Zalesak’s disk, and stretching and shrinking of a circular fluid element. The numerical results indicate that the proposed CVOFLS method not only accurately captures the complex interface evolution and preserves the mass conservation, but also greatly improves the computational efficiency.%针对VOF方法中界面法向量计算不准确和level set方法中界面质量守恒性差的缺陷,本文提出了一种新的界面捕捉方法—CVOFLS (coupled volume of fluid and level set)方法.该方法吸收了VOF和level set两种方法的优点,在每个时间步内,首先求解level set输运方程,根据level set符号距离函数计算界面法向量;然后求解VOF输运方程,根据流体体积分数重构界面并校正流体质量.Zalesak圆盘旋转及圆面剪切的数值模拟表明,该方法能准确捕捉复杂的界面演化过程,具有良好的质量守恒性,并可以提高计算效率.

  4. The Influence of Nanoadditives on the Biological Properties and Chemical Composition of Process Fluids

    Directory of Open Access Journals (Sweden)

    Borůvková K.

    2015-12-01

    Full Text Available In this study process fluids were tested after the addition of nanoparticles. Cooling and lubricating process fluids are used in machining to reduce wear on tools, to increase machine performance and to improve product quality. The use of process fluids leads to their pollution and contamination. Nanoparticles were added to the process fluids in order to increase their antibacterial activity. The selected nanoparticles were nanoparticles of metallic silver. The process fluids were modified by the addition of silver nitrate and ascorbic acid. Reduction of silver nanoparticles in the volume of the fluid was achieved using UV. The modified fluids were tested for their cytotoxicity and changes in chemical composition. The cytotoxicity of process fluids was tested for the purpose of verifying whether the process fluids, which are in direct contact with the skin of the operator, affect the health of the operator. The cytotoxicity of the process fluids was tested on human fibroblast cells. Fibroblasts are the basic cells of fibrous tissue. The cytotoxicity was tested by measuring the cell viability and using XTT. Analysis of chemical composition was performed for the purpose of determining the individual substances in the process fluids and their chemical stability. Qualitative analysis of the process fluids was performed using gas chromatography mass spectrometry (GC - MS.

  5. Direct detection of illicit drugs from biological fluids by desorption/ionization mass spectrometry with nanoporous silicon microparticles.

    Science.gov (United States)

    Guinan, T M; Kirkbride, P; Della Vedova, C B; Kershaw, S G; Kobus, H; Voelcker, N H

    2015-12-01

    Surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) is a high throughput analytical technique capable of detecting low molecular weight analytes, including illicit drugs, and with potential applications in forensic toxicology as well as athlete and workplace testing, particularly for biological fluids (oral fluids, urine and blood). However, successful detection of illicit drugs using SALDI-MS often requires extraction steps to reduce the inherent complexity of biological fluids. Here, we demonstrate an all-in-one extraction and analytical system consisting of hydrophobically functionalized porous silicon microparticles (pSi-MPs) for affinity SALDI-MS of prescription and illicit drugs. This novel approach allows for the analysis of drugs from multiple biological fluids without sample preparation protocols. The effect of pSi-MP size, pore diameter, pore depth and functionalization on analytical performance is investigated. pSi-MPs were optimized for the rapid and high sensitivity detection of methadone, cocaine and 3,4-methylenedioxymethamphetamine (MDMA). This optimized system allowed extraction and detection of methadone from spiked saliva and clinical urine samples. Furthermore, by detecting oxycodone in additional clinical saliva and plasma samples, we were able to demonstrate the versatility of the pSi-MP SALDI-MS technique. PMID:26502296

  6. Microparticles as biomarkers of lung disease: enumeration in biological fluids using lipid bilayer microspheres.

    Science.gov (United States)

    McVey, Mark J; Spring, Christopher M; Semple, John W; Maishan, Mazharul; Kuebler, Wolfgang M

    2016-05-01

    Extracellular vesicles, specifically microparticles (MPs), are rapidly gaining attention for their capacity to act as biomarkers for diagnosis, prognosis, or responsiveness to therapy in lung disease, in keeping with the concept of precision medicine. However, MP analysis by high-sensitivity flow cytometry (FCM) is complicated by a lack of accurate means for MP enumeration. To address this gap, we report here an enhanced FCM MP gating and enumeration technique based on the use of novel engineered lipid bilayer microspheres (LBMs). By comparison of LBM-based MP enumeration with conventional bead- or fluorescent-based FCM enumeration techniques and a gravimetric consumption gold standard, we found LBMs to be superior to commercial bead preparations, showing the smallest fixed bias and limits of agreement in Bland Altman analyses. LBMs had simultaneous capacity to aid FCM enumeration of MPs in plasma, BAL, and cell culture supernatants. LBM enumeration detected differences in MP counts in mice exposed to intraperitoneal lipopolysaccharide or saline. LBMs provided for 1) higher sensitivity for gating MPs populations, 2) reduced background within MP gates, 3) more appropriate size, and 4) an inexpensive alternative amenable to different fluorescent tags. LBM-based MP enumeration was useful for a series of different FCM systems assessed, whereas LBM gating benefited high- but not low-sensitivity FCM systems compared with fluorescence gating. By offering exclusive advantages over current means of gating and enumerating MPs, LBMs are uniquely suited to realizing the potential of MPs as biomarkers in biological lung fluids and facilitating precision medicine in lung disease. PMID:26944090

  7. Genetic markers in biological fluids for aging-related major neurocognitive disorder.

    Science.gov (United States)

    Castro-Chavira, S A; Fernandez, T; Nicolini, H; Diaz-Cintra, S; Prado-Alcala, R A

    2015-01-01

    Aging-related major neurocognitive disorder (NCD), formerly named dementia, comprises of the different acquired diseases whose primary deficit is impairment in cognitive functions such as complex attention, executive function, learning and memory, language, perceptual/motor skills, and social cognition, and that are related to specific brain regions and/or networks. According to its etiology, the most common subtypes of major NCDs are due to Alzheimer' s disease (AD), vascular disease (VaD), Lewy body disease (LBD), and frontotemporal lobar degeneration (FTLD). These pathologies are frequently present in mixed forms, i.e., AD plus VaD or AD plus LBD, thus diagnosed as due to multiple etiologies. In this paper, the definitions, criteria, pathologies, subtypes and genetic markers for the most common age-related major NCD subtypes are summarized. The current diagnostic criteria consider cognitive decline leading to major NCD or dementia as a progressive degenerative process with an underlying neuropathology that begins before the manifestation of symptoms. Biomarkers associated with this asymptomatic phase are being developed as accurate risk factor and biomarker assessments are fundamental to provide timely treatment since no treatments to prevent or cure NCD yet exist. Biological fluid assessment represents a safer, cheaper and less invasive method compared to contrast imaging studies to predict NCD appearance. Genetic factors particularly have a key role not only in predicting development of the disease but also the age of onset as well as the presentation of comorbidities that may contribute to the disease pathology and trigger synergistic mechanisms which may, in turn, accelerate the neurodegenerative process and its resultant behavioral and functional disorders. PMID:25731625

  8. Rapid detection of Pseudomonas aeruginosa biomarkers in biological fluids using surface-enhanced Raman scattering

    Science.gov (United States)

    Wu, Xiaomeng; Chen, Jing; Zhao, Yiping; Zughaier, Susu M.

    2014-05-01

    Pseudomonas aeruginosa (PA) is an opportunistic pathogen that causes major infection not only in Cystic Fibrosis patients but also in chronic obstructive pulmonary disease and in critically ill patients in intensive care units. Successful antibiotic treatment of the infection relies on accurate and rapid identification of the infectious agents. Conventional microbiological detection methods usually take more than 3 days to obtain accurate results. We have developed a rapid diagnostic technique based on surface-enhanced Raman scattering to directly identify PA from biological fluids. P. aeruginosa strains, PAO1 and PA14, are cultured in lysogeny broth, and the SERS spectra of the broth show the signature Raman peaks from pyocyanin and pyoverdine, two major biomarkers that P. aeruginosa secretes during its growth, as well as lipopolysaccharides. This provides the evidence that the presence of these biomarkers can be used to indicate P. aeruginosa infection. A total of 22 clinical exhaled breath condensates (EBC) samples were obtained from subjects with CF disease and from non-CF healthy donors. SERS spectra of these EBC samples were obtained and further analyzed by both principle component analysis and partial least square-discriminant analysis (PLS-DA). PLS-DA can discriminate the samples with P. aeruginosa infection and the ones without P. aeruginosa infection at 99.3% sensitivity and 99.6% specificity. In addition, this technique can also discriminate samples from subject with CF disease and healthy donor with 97.5% sensitivity and 100% specificity. These results demonstrate the potential of using SERS of EBC samples as a rapid diagnostic tool to detect PA infection.

  9. Highly selective electrode for potentiometric analysis of methadone in biological fluids and pharmaceutical formulations.

    Science.gov (United States)

    Ardeshiri, Moslem; Jalali, Fahimeh

    2016-06-01

    In order to develop a fast and simple procedure for methadone analysis in biological fluids, a graphite paste electrode (GPE) was modified with the ion-pair of methadone-phosphotungstic acid, and multiwalled carbon nanotubes (MWCNTs). Optimized composition of the electrode with respect to graphite powder:paraffin oil:MWCNTs:ion pair, was 58:30:8:4 (w/w%). The electrode showed a near-Nernstian slope of 58.9±0.3mV/decade for methadone in a wide linear range of 1.0×10(-8)-4.6×10(-3)M, with a detection limit of 1.0×10(-8)M. The electrode response was independent of pH in the range of 5-11, with a fast response time (~4s) at 25°C. The sensor showed high selectivity and was successfully applied to the determination of sub-micromolar concentrations of methadone in human blood serum and urine samples, with recoveries in the range of 95-99.8%. The average recovery of methadone from tablets (5mg/tablet) by using the proposed method was 98%. The life time of the modified electrode was more than 5months, due to the characteristic of GPE which can be cut off and fresh electrode surface be available. A titration procedure was performed for methadone analysis by using phosphotungstic acid, as titrating agent, which showed an accurate end point and 1:1 stoichiometry for the ion-pair formed (methadone:phosphotungstic acid). The simple and rapid procedure as well as excellent detection limit and selectivity are some of the advantages of the proposed sensor for methadone. PMID:27040192

  10. Radiation and mass transfer effects on unsteady MHD free convection flow of an incompressible viscous fluid past a moving vertical cylinder

    Directory of Open Access Journals (Sweden)

    Gnaneswara Reddy M.

    2009-01-01

    Full Text Available The interaction of free convection with thermal radiation of a viscous incompressible unsteady MHD flow past a moving vertical cylinder with heat and mass transfer is analyzed. The fluid is a gray, absorbing-emitting but non-scattering medium and the Rosseland approximation is used to describe the radiative heat flux in the energy equation. The governing equations are solved using an implicit finite-difference scheme of Crank-Nicolson type. Numerical results for the transient velocity, the temperature, the concentration, the local as well as average skin-friction, the rate of heat and mass transfer for various parameters such as thermal Grashof number, mass Grashof number, magnetic parameter, radiation parameter and Schmidt number are shown graphically. It is observed that, when the radiation parameter increases the velocity and temperature decrease in the boundary layer. Also, it is found that as increase in the magnetic field leads to decrease in the velocity field and rise in the thermal boundary thickness.

  11. Supercritical Fluid Extraction and Ultra Performance Liquid Chromatography of Respiratory Quinones for Microbial Community Analysis in Environmental and Biological Samples

    OpenAIRE

    Koichi Fujie; Hiroyuki Daimon; Yoichi Atsuta; Muhammad Hanif

    2012-01-01

    Microbial community structure plays a significant role in environmental assessment and animal health management. The development of a superior analytical strategy for the characterization of microbial community structure is an ongoing challenge. In this study, we developed an effective supercritical fluid extraction (SFE) and ultra performance liquid chromatography (UPLC) method for the analysis of bacterial respiratory quinones (RQ) in environmental and biological samples. RQ profile analysi...

  12. Spectrophotometric Determination of Thioridazine Hydrochloride in Tablets and Biological Fluids by Ion-Pair and Oxidation Reactions

    OpenAIRE

    El-Didamony, Akram; Hafeez, Sameh

    2012-01-01

    Two simple, sensitive and selective spectrophotometric methods have been described for the determination of the psychoactive drug, thioridazine HCl in tablets and in biological fluids. The first method is based on the oxidation of thioridazine HCl with measured excess of KMnO4 under acidic conditions followed by the determination of unreacted oxidant using indigo carmine and methyl orange. The second method is based on the formation of ion-pair complexes with the acidic sulphophthalein dyes s...

  13. STUDY ON APPLICATION OF AERATION BIOLOGICAL FLUID TANK TECHNOLGY IN NH4+—N WASTE WATER TREATMENT

    Institute of Scientific and Technical Information of China (English)

    CHENYi; LUJian-guo

    2003-01-01

    This paper introduces an application of "Aeration biological fluid tank"technology (ABFT) for the treatment of waste water containing NH4+-N and high concentrated chemicals.Highlights were focused on the effects of dissolved oxygen,pH,temperature and retention time on waste water bilogical treatment in order to find out a new approach in treatment of waste time on containing high concentrated NH4+-N.

  14. The radioimmunoassay of biologically active compounds in parotid fluid and plasma

    International Nuclear Information System (INIS)

    Parotid fluid collection is a simple stress-free procedure. The potential value of parotid fluid estimations of clomipramine, a tricyclic antidepressant, d-norgestrel, a synthetic contraceptive steroid and cortisol have been evaluated for assessment of clinical status and patient compliance. These compounds circulate bound largely to plasma proteins. Their concentration in parotid fluid, which reflects the non-protein bound fraction, is low but assay sensitivity (10, 1 and 30 pg/tube respectively) is adequate. Excellent agreement (r>0.9) was observed when parotid fluid samples were assayed with and without chromatographic purification. Clomipramine levels following oral dosage (150 mg) rose steadily to a maximum in plasma but showed wide fluctuations in parotid fluid. Clomipramine therapy can only be assessed by plasma assays, but patient compliance may be checked by parotid fluid concentrations. Following an oral dose of d-norgestrel (0.3 mg), parotid fluid levels rose steadily to a maximum but plasma response was biphasic making correlation impossible. The sensitivity and high throughput of the d-norgestrel methodology suggests its use in evaluating patient compliance in large-scale fertility control programmes. Changes in circulating cortisol concentrations were rapidly and accurately reflected in parotid fluid in normal volunteers. Parotid fluid cortisol showed a marked diurnal rhythm, suppression to low levels after dexamethasone, and elevation following Synacthen. Low levels after Synacthen stimulation in a patient with secondary adrenal atrophy and constant high levels in Cushingoid patients indicate that parotid fluid cortisol levels could be used for accurate adrenocortical evaluation. The value in rapid screening procedures is stressed since the assay can be performed directly on only 10 μl of parotid fluid. (author)

  15. The radioimmunoassay of biologically active compounds in parotid fluid and plasma

    International Nuclear Information System (INIS)

    The potential value of parotid fluid estimations of clomipramine, d-norgestrel, and cortisol have been evaluated for assessment of clinical status and patient compliance. Excellent agreement (r > 0.9) was observed when parotid fluid samples were assayed with and without chromatographic purification. Clomipramine levels following oral dosage (150mg) rose steadily to a maximum in plasma but showed wide fluctuations in parotid fluid. Following an oral dose of d-norgestrel(0.3mg), parotid fluid levels rose steadily to a maximum but plasma response was biphasic making correlation impossible. The sensitivity and high throughput of the d-norgestrel methodology suggests its use in evaluating patient compliance in large scale fertility control programmes. Changes in circulating cortisol concentrations were rapidly and accurately reflected in parotid fluid in normal volunteers. Parotid fluid cortisol showed a market diurnal rythm, suppression to low levels after dexamethasone, and elevation following Synacthen. Low levels after Synacthen stimulation in a patient with secondary adrenal atrophy and constant high levels in Cushingoid patients indicate that parotid fluid cortisol levels could be used for accurate adrenocortical evaluation. The value in rapid screening procedures is stressed since the assay can be performed directly on only 10μl of parotid fluid. (orig./AJ)

  16. A review of chromatographic methods for the determination of water- and fat-soluble vitamins in biological fluids.

    Science.gov (United States)

    Karaźniewicz-Łada, Marta; Główka, Anna

    2016-01-01

    Vitamins are an essential element of nutrition and thus contribute to human health. Vitamins catalyze many biochemical reactions and their lack or excess can cause health problems. Therefore, monitoring vitamin concentrations in plasma or other biological fluids may be useful in the diagnosis of various disorders as well as in the treatment process. Several chromatographic methods have been developed for the determination of these compounds in biological samples, including high-performance liquid chromatography with UV and fluorescence detection. Recently, high-performance liquid chromatography with tandem mass spectrometry methods have been widely used for the determination of vitamins in complex matrices because of their high sensitivity and selectivity. This method requires preconditioning of samples for analysis, including protein precipitation and/or various extraction techniques. The choice of method may depend on the desired cost, convenience, turnaround time, specificity, and accuracy of the information to be obtained. This article reviews the recently reported chromatographic methods used for determination of vitamins in biological fluids. Relevant papers published mostly during the last 5 years were identified by an extensive PubMed search using appropriate keywords. Particular attention was given to the preparation steps and extraction techniques. This report may be helpful in the selection of procedures that are appropriate for certain types of biological materials and analytes. PMID:26503668

  17. High performance liquid chromatography coupled with radioactivity detection: a powerful tool for determining drug metabolite profiles in biological fluids.

    Science.gov (United States)

    Vollmer, K O; Klemisch, W; von Hodenberg, A

    1986-01-01

    High performance liquid chromatography coupled with continuous radioactivity detection represents an advancement in drug metabolism research. Using radioactive substances labelled in biologically stable positions, all metabolites can be specifically detected by radioactivity measurement. Thus no clean-up of biological fluids is required prior to HPLC. This can prevent artefact formation from unstable metabolites, reduces recovery problems and facilitates quantitation. Separation of highly polar and unpolar metabolites is possible in a single chromatographic run using gradient elution and reversed phase materials. This technique is also well-suited for preparative isolation and purification of metabolites for subsequent structure elucidation. Various metabolite profiles of drugs labelled with carbon-14 or tritium are shown. Metabolites of the following drugs are presented: norfenefrine, etozolin, thymoxamine, naloxone, and levobunolol. We review the general methodology and report our experience with this technique. In principle, this technique may be useful for all biological systems in which tracer techniques are applied. PMID:2939640

  18. Advances in systems biology are enhancing our understanding of disease and moving us closer to novel disease treatments.

    Science.gov (United States)

    Schadt, Eric E; Zhang, Bin; Zhu, Jun

    2009-06-01

    With tens of billions of dollars spent each year on the development of drugs to treat human diseases, and with fewer and fewer applications for investigational new drugs filed each year despite this massive spending, questions now abound on what changes to the drug discovery paradigm can be made to achieve greater success. The high rate of failure of drug candidates in clinical development, where the great majority of these drugs fail due to lack of efficacy, speak directly to the need for more innovative approaches to study the mechanisms of disease and drug discovery. Here we review systems biology approaches that have been devised over the last several years to understand the biology of disease at a more holistic level. By integrating a diversity of data like DNA variation, gene expression, protein-protein interaction, DNA-protein binding, and other types of molecular phenotype data, more comprehensive networks of genes both within and between tissues can be constructed to paint a more complete picture of the molecular processes underlying physiological states associated with disease. These more integrative, systems-level methods lead to networks that are demonstrably predictive, which in turn provides a deeper context within which single genes operate such as those identified from genome-wide association studies or those targeted for therapeutic intervention. The more comprehensive views of disease that result from these methods have the potential to dramatically enhance the way in which novel drug targets are identified and developed, ultimately increasing the probability of success for taking new drugs through clinical development. We highlight a number of the integrative approaches via examples that have resulted not only in the identification of novel genes for diabetes and cardiovascular disease, but in more comprehensive networks as well that describe the context in which the disease genes operate. PMID:19363597

  19. Biological half-life and transfer of maternal corticosteroid-binding globulin to amniotic fluid in the rabbit

    International Nuclear Information System (INIS)

    Rabbit corticosteroid-binding globulin (CBG) from the serum of pregnant and nonpregnant females differs in terms of charge microheterogeneity, and both forms were, therefore, radiolabeled and injected iv into 23- to 27-day pregnant rabbits (n = 6) to assess their biological half-lives and possible transfer to the fetal compartment. After an initially rapid distribution phase, the serum half-lives of both forms of [125I]CBG were essentially identical (approximately 13 h) and did not vary at different gestational ages. There was also no difference in the transfer of either form of [125I]CBG from maternal to fetal compartments in any of the animals studied. Moreover, [125I]CBG showed no sign of degradation and retained its steroid-binding activity in fetal urine and amniotic fluid. Twenty-two hours after administration of [125I]CBG to rabbits (n = 2) at 23 days gestation, its mean level in fetal urine (7 cpm/microliter) and amniotic fluid (2.5 cpm/microliter) was much higher than that in fetal blood (0.6 cpm/microliter). More importantly, the specific activities of [125I]CBG in fetal urine and amniotic fluid were comparable to that in maternal serum, and approximately 2 orders of magnitude higher than that in fetal serum. Taken together, these results suggest that CBG in fetal urine and amniotic fluid is largely of maternal origin, and that maternal CBG crosses the fetal kidney preferentially

  20. Deep ancient fluids in the continental crust and their impact on near-surface economic, environmental and biological systems.

    Science.gov (United States)

    Ballentine, Christopher; Warr, Oliver; Sutcliffe, Chelsea; McDermott, Jill; Fellowes, Jonathan; Holland, Greg; Mabry, Jennifer; Sherwood Lollar, Barbara

    2016-04-01

    With a few exceptions the mobility of water, oil and gas, provides for an ephemeral view of subsurface fluids relative to geological or planetary timescales. Aquifers supplying water for drinking and irrigation have mean residence ages from hundreds to tens of thousands of years; Hydrothermal systems can be active for hundreds of thousands to millions of years forming key mineral reserves; Sedimentary basin formation expels fluids during compaction and generates oil and gas on times scales of millions to hundreds of millions of years. Within these exemplar systems biological activity can play a crucial role by mediating system oxidation state: releasing arsenic into shallow groundwaters; precipitating ore bodies; generating methane; and biodegrading oil. It is becoming increasingly apparent that fluids resident in fractures and porespace in the crystalline basement underlying many of these systems can have a mean residence time that ranges from tens to hundreds of millions of years [1,2] to billions of years [3,4]. These fluids are highly saline and trace element rich; they are abundant in nitrogen, hydrogen, methane and helium and can contain microbes that have uniquely adapted to these isolated environments [5]. We are actively expanding discovery of sites with fluids exhibiting extreme age and have recently shown that these systems contribute to half of the terrestrial hydrogen production; a key component in biosphere energy and carbon cycles [6]. Tectonic or thermal release of these fluids can result in helium deposits; possible ore body generation and the inoculation of near-surface systems with microbial biota protected in the deep surface; the controls and rate of fluid release to shallow systems can fundamentally change the nature of some shallow systems. These deep ancient fluids represent a little tapped scientific resource for understanding how life survives and evolves in such isolation, how life is transported and communicates in extremis together and

  1. An overview of the analytical methods for the determination of organic ultraviolet filters in biological fluids and tissues

    Energy Technology Data Exchange (ETDEWEB)

    Chisvert, Alberto, E-mail: alberto.chisvert@uv.es [Departamento de Quimica Analitica, Facultad de Quimica, Universitat de Valencia, Doctor Moliner St. 50, 46100 Burjassot, Valencia (Spain); Leon-Gonzalez, Zacarias [Unidad Analitica, Instituto de Investigacion Sanitaria Fundacion Hospital La Fe, 46009 Valencia (Spain); Tarazona, Isuha; Salvador, Amparo [Departamento de Quimica Analitica, Facultad de Quimica, Universitat de Valencia, Doctor Moliner St. 50, 46100 Burjassot, Valencia (Spain); Giokas, Dimosthenis [Laboratory of Analytical Chemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina (Greece)

    2012-11-08

    Highlights: Black-Right-Pointing-Pointer Papers describing the determination of UV filters in fluids and tissues are reviewed. Black-Right-Pointing-Pointer Matrix complexity and low amounts of analytes require effective sample treatments. Black-Right-Pointing-Pointer The published papers do not cover the study of all the substances allowed as UV filters. Black-Right-Pointing-Pointer New analytical methods for UV filters determination in these matrices are encouraged. - Abstract: Organic UV filters are chemical compounds added to cosmetic sunscreen products in order to protect users from UV solar radiation. The need of broad-spectrum protection to avoid the deleterious effects of solar radiation has triggered a trend in the cosmetic market of including these compounds not only in those exclusively designed for sun protection but also in all types of cosmetic products. Different studies have shown that organic UV filters can be absorbed through the skin after topical application, further metabolized in the body and eventually excreted or bioaccumulated. These percutaneous absorption processes may result in various adverse health effects, such as genotoxicity caused by the generation of free radicals, which can even lead to mutagenic or carcinogenic effects, and estrogenicity, which is associated with the endocrine disruption activity caused by some of these compounds. Due to the absence of official monitoring protocols, there is a demand for analytical methods that enable the determination of UV filters in biological fluids and tissues in order to retrieve more information regarding their behavior in the human body and thus encourage the development of safer cosmetic formulations. In view of this demand, there has recently been a noticeable increase in the development of sensitive and selective analytical methods for the determination of UV filters and their metabolites in biological fluids (i.e., urine, plasma, breast milk and semen) and tissues. The complexity of

  2. An overview of the analytical methods for the determination of organic ultraviolet filters in biological fluids and tissues

    International Nuclear Information System (INIS)

    Highlights: ► Papers describing the determination of UV filters in fluids and tissues are reviewed. ► Matrix complexity and low amounts of analytes require effective sample treatments. ► The published papers do not cover the study of all the substances allowed as UV filters. ► New analytical methods for UV filters determination in these matrices are encouraged. - Abstract: Organic UV filters are chemical compounds added to cosmetic sunscreen products in order to protect users from UV solar radiation. The need of broad-spectrum protection to avoid the deleterious effects of solar radiation has triggered a trend in the cosmetic market of including these compounds not only in those exclusively designed for sun protection but also in all types of cosmetic products. Different studies have shown that organic UV filters can be absorbed through the skin after topical application, further metabolized in the body and eventually excreted or bioaccumulated. These percutaneous absorption processes may result in various adverse health effects, such as genotoxicity caused by the generation of free radicals, which can even lead to mutagenic or carcinogenic effects, and estrogenicity, which is associated with the endocrine disruption activity caused by some of these compounds. Due to the absence of official monitoring protocols, there is a demand for analytical methods that enable the determination of UV filters in biological fluids and tissues in order to retrieve more information regarding their behavior in the human body and thus encourage the development of safer cosmetic formulations. In view of this demand, there has recently been a noticeable increase in the development of sensitive and selective analytical methods for the determination of UV filters and their metabolites in biological fluids (i.e., urine, plasma, breast milk and semen) and tissues. The complexity of the biological matrix and the low concentration levels of these compounds inevitably impose sample

  3. Molecular biology of the blood-brain and the blood-cerebrospinal fluid barriers: similarities and differences

    Directory of Open Access Journals (Sweden)

    Redzic Zoran

    2011-01-01

    Full Text Available Abstract Efficient processing of information by the central nervous system (CNS represents an important evolutionary advantage. Thus, homeostatic mechanisms have developed that provide appropriate circumstances for neuronal signaling, including a highly controlled and stable microenvironment. To provide such a milieu for neurons, extracellular fluids of the CNS are separated from the changeable environment of blood at three major interfaces: at the brain capillaries by the blood-brain barrier (BBB, which is localized at the level of the endothelial cells and separates brain interstitial fluid (ISF from blood; at the epithelial layer of four choroid plexuses, the blood-cerebrospinal fluid (CSF barrier (BCSFB, which separates CSF from the CP ISF, and at the arachnoid barrier. The two barriers that represent the largest interface between blood and brain extracellular fluids, the BBB and the BCSFB, prevent the free paracellular diffusion of polar molecules by complex morphological features, including tight junctions (TJs that interconnect the endothelial and epithelial cells, respectively. The first part of this review focuses on the molecular biology of TJs and adherens junctions in the brain capillary endothelial cells and in the CP epithelial cells. However, normal function of the CNS depends on a constant supply of essential molecules, like glucose and amino acids from the blood, exchange of electrolytes between brain extracellular fluids and blood, as well as on efficient removal of metabolic waste products and excess neurotransmitters from the brain ISF. Therefore, a number of specific transport proteins are expressed in brain capillary endothelial cells and CP epithelial cells that provide transport of nutrients and ions into the CNS and removal of waste products and ions from the CSF. The second part of this review concentrates on the molecular biology of various solute carrier (SLC transport proteins at those two barriers and underlines

  4. Portable capillary electrophoresis instrument with contactless conductivity detection for on-site analysis of small volumes of biological fluids.

    Science.gov (United States)

    Greguš, Michal; Foret, František; Kubáň, Petr

    2016-01-01

    A novel, easy to use and portable capillary electrophoretic instrument for injection of small volumes of biological fluids equipped with contactless conductivity detection was constructed. The instrument is lightweight (parts including a tablet computer are accommodated in a plastic briefcase with dimensions 20 cm × 33 cm × 17 cm (w × l × h), allows hydrodynamic injection of small sample volumes and can continuously operate for at least 10 hours. The semi-automated hydrodynamic sample injection is accomplished via a specially designed PMMA interface that is able to repeatedly inject sample aliquots from a sample volume as low as 10 μL, with repeatability of peak areas below 5%. The developed interface and the instrument were optimized for the injection of biological fluids. Practical utility was demonstrated on the determination of formate in blood serum samples from acute methanol intoxication patients and on the analysis of ionic profile (nitrosative stress markers, including nitrite and nitrate) in the exhaled breath condensate from one single exhalation. PMID:26709071

  5. Preformulation and stability in biological fluids of the retrocyclin RC-101, a potential anti-HIV topical microbicide

    Directory of Open Access Journals (Sweden)

    Conrads Thomas P

    2011-07-01

    Full Text Available Abstract Background RC-101, a cationic peptide retrocyclin analog, has in vitro activity against HIV-1. Peptide drugs are commonly prone to conformational changes, oxidation and hydrolysis when exposed to excipients in a formulation or biological fluids in the body, this can affect product efficacy. We aimed to investigate RC-101 stability under several conditions including the presence of human vaginal fluids (HVF, enabling the efficient design of a safe and effective microbicide product. Stability studies (temperature, pH, and oxidation were performed by HPLC, Circular Dichroism, and Mass Spectrometry (LC-MS/MS. Additionally, the effect of HVF on formulated RC-101 was evaluated with fluids collected from healthy volunteers, or from subjects with bacterial vaginosis (BV. RC-101 was monitored by LC-MS/MS for up to 72 h. Results RC-101 was stable at pH 3, 4, and 7, at 25 and 37°C. High concentrations of hydrogen peroxide resulted in less than 10% RC-101 reduction over 24 h. RC-101 was detected 48 h after incubation with normal HVF; however, not following incubation with HVF from BV subjects. Conclusions Our results emphasize the importance of preformulation evaluations and highlight the impact of HVF on microbicide product stability and efficacy. RC-101 was stable in normal HVF for at least 48 h, indicating that it is a promising candidate for microbicide product development. However, RC-101 stability appears compromised in individuals with BV, requiring more advanced formulation strategies for stabilization in this environment.

  6. Influence of the biological fluid on the corrosion of dental amalgam

    OpenAIRE

    Brett, Christopher M. A.; Ioanitescu, Iulia; Trandafir, Florin

    2004-01-01

    An electrochemical study of corrosion of Tytin® dental amalgam was carried out in electrolytes similar to body fluids: artificial saliva with or without lactic acid, a polymer-containing product of the same composition as Glandosane® and in Krebs-Ringer solution. The electrochemical techniques of open circuit potential, polarisation curves, cyclic voltammetry and electrochemical impedance were employed as a function of immersion time to characterise the surface processes occurring and bring o...

  7. Calibrated Real-Time PCR Assay for Quantitation of Human Herpesvirus 8 DNA in Biological Fluids

    OpenAIRE

    Broccolo, Francesco; Locatelli, Giuseppe; Sarmati, Loredana; Piergiovanni, Sara; Veglia, Fabrizio; Andreoni, Massimo; Buttò, Stefano; Ensoli, Barbara; Lusso, Paolo; Malnati, Mauro S.

    2002-01-01

    Accurate laboratory tests for the diagnosis of active human herpesvirus 8 (HHV-8) infection are becoming essential to study the pathogenesis of HHV-8-associated tumors and for the clinical management of HHV-8-infected individuals. We have developed a highly sensitive, calibrated quantitative real-time PCR assay for the measurement of cell-free HHV-8 DNA in body fluids, based on the addition of a synthetic DNA calibrator prior to DNA extraction. The calibrator controls each sample for the pres...

  8. New rheometer geometry to characterize delicate biological fluids in-situ

    Science.gov (United States)

    Connelly, Kelly; Young, Ethan; Hubschman, Jean-Pierre; Eldredge, Jeff; Kavehpour, Pirouz

    2015-11-01

    The vitreous humor is a viscoelastic gel-like fluid that fills and maintains the structure of the eye. Changes in the structure of the network of macromolecules in vitreous occurs naturally during ageing causing pathological conditions such as retinal tears that may lead to blindness. Vitrectomy surgery is a common procedure to remove problematic vitreous from the eye, but must be carefully performed to prevent iatrogenic retinal tears. Minimizing invasiveness and surgical time depends on the viscoelastic behavior of vitreous as it flows from the eye out through a small gauge needle. Rheology has been used to correlate relevant viscoelastic fluid properties with the macromolecular structure previously using parallel plate rheometer geometries, and now with a new patented probe geometry. This improves upon plate geometries because measurements are in situ, so removal of the vitreous from the eye is not necessary. Creep rheological experiments with the probe indicate a region of elastic behavior exists at shorter timescales and steady state apparent viscosity at longer timescales. In-situ creep tests advance understanding of how macromolecular structure alters viscoelasticity, which may allow better predictions of fluid flow during vitrectomy in the future. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship Program under Grant No. DGE-1144087.

  9. GOMA - A full-Newton finite element program for free and moving boundary problems with coupled fluid/solid momentum, energy, mass, and chemical species transport: User`s guide

    Energy Technology Data Exchange (ETDEWEB)

    Schunk, P.R.; Sackinger, P.A.; Rao, R.R. [and others

    1996-01-01

    GOMA is a two- and three-dimensional finite element program which excels in analyses of manufacturing processes, particularly those involving free or moving interfaces. Specifically, the full-Newton-coupled heat, mass, momentum, and pseudo-solid mesh motion algorithm makes GOMA ideally suited for simulating processes in which the bulk fluid transport is closely coupled to the interfacial physics. Examples include, but are not limited to, coating and polymer processing flows, soldering, crystal growth, and solid-network or solution film drying. The code is based on the premise that any boundary can be (1) moving or free, with an apriori unknown position dictated by the distinguishing physics, (2) fixed, according to a global analytical representation, or (3) moving in time and space under user-prescribed kinematics. The goal is to enable the user to predict boundary position or motion simultaneously with the physics of the problem being analyzed and to pursue geometrical design studies and fluid-structure interaction problems. The moving mesh algorithm treats the entire domain as a computational Lagrangian solid that deforms subject to the physical principles which dictate boundary position. As an added benefit, the same Lagrangian solid mechanics can be exploited to solve multi-field problems for which the solid motion and stresses interact with other transport phenomena, either within the same material phase (e.g. shrinking coating) or in neighboring material phases (e.g. flexible blade coating). Thus, analyses of many fluid-structure interaction problems and deformable porous media problems are accessible. This document serves as a user`s guide and reference for GOMA and provides a brief overview of GOMA`s capabilities, theoretical background, and classes of problems for which it is targeted.

  10. Relative solubiolity in simulated biological fluids of PuO2 on air sampler filters

    International Nuclear Information System (INIS)

    An ultrafiltration method was developed to estimate the solubility of PuO2 on an air filter in simulated lung fluid (SLF), simulated gastric juice (SGJ), and in 1% DTPA. After a very rapid early appearance in the filtrate, both 238Pu and 239Pu showed similar rates of low ultrafilterability. The amount of 239Pu appearing during the first day of ultrafiltration was 10 times less in SLF than in SGJ or DTPA, although the amount of 238Pu was similar for the three solvents. The method used to estimate solubility requires only about 1000 dpm of plutonium alpha radiation per sample

  11. Surfaces resistant to fouling from biological fluids: towards bioactive surfaces for real applications

    Czech Academy of Sciences Publication Activity Database

    Rodriguez-Emmenegger, Cesar; Houska, Milan; Bologna Alles, A.; Brynda, Eduard

    2012-01-01

    Roč. 12, č. 10 (2012), s. 1413-1422. ISSN 1616-5187 R&D Projects: GA ČR GAP205/12/1702; GA ČR GAP106/12/1451; GA ČR GAP503/10/0664; GA ČR GBP205/12/G118 Institutional research plan: CEZ:AV0Z40500505 Institutional support: RVO:61389013 Keywords : affinity biosensors * blood plasma * cerebrospinal fluid Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.742, year: 2012

  12. Harmonisation of chemical and biological process in development of a hybrid technology for treatment of recalcitrant metalworking fluid.

    Science.gov (United States)

    Jagadevan, Sheeja; Dobson, Peter; Thompson, Ian P

    2011-10-01

    Disposal of operationally exhausted metalworking fluids (MWFs) is enormously challenging. In this study the feasibility of employing a sequential Fenton-biological oxidation for the treatment of recalcitrant components of MWF wastewater was investigated. A statistical experimental design was employed to address Fenton reagent (H₂O₂, Fe²⁺) dose optimisation which ensured minimal concentrations of the reagents, thus making the treatment environmentally less toxic to subsequent biological steps and economically viable. This was achieved by employing a five-level-two-variable central composite experimental design. The results demonstrated that Fenton pre-treatment of the MWF effluent greatly improved biodegradability index (BOD₅)/COD increased from 0.160 to 0.538) with a synchronous lowering in the toxicity of the wastewater, making the recalcitrant component more amenable to subsequent biological treatment. An overall decrease of 92% and 86% in chemical oxygen demand (COD) and total organic carbon (TOC), respectively, was achieved by the two-step treatment method developed. PMID:21831632

  13. Photoemission study of metallic iron nanoparticles surface aging in biological fluids. Influence on biomolecules adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Canivet, L.; Denayer, F.O. [Université de Lille 2, Droit et Santé, 42 rue P. Duez, 59000 Lille (France); Champion, Y.; Cenedese, P. [CNRS-ICMPE, 2 rue H. Dunant, 94320 Thiais (France); Dubot, P., E-mail: pdubot@icmpe.cnrs.fr [CNRS-ICMPE, 2 rue H. Dunant, 94320 Thiais (France)

    2014-07-01

    Iron nanoparticles (nFe) prepared by vaporization and cryogenic condensation process (10–100 nm) has been exposed to Hank's balanced salt solution (HBSS) and the B-Ali cell growth fluids. These media can be used for cellular growth to study nFe penetration through cell membrane and its induced cytotoxicity. Surface chemistry of nFe exposed to such complex fluids has been characterized as the nanoparticles surface can be strongly changed by adsorption or corrosion processes before reaching intracellular medium. Particle size and surface chemistry have been characterized by scanning electron microscopy (SEM) and high-resolution X-ray photoelectron spectroscopy (HR-XPS). Exposition of nFe particles to growth and differentiation media leads to the formation of an oxy-hydroxide layer containing chlorinated species. We found that the passivated Fe{sub 2}O{sub 3} layer of the bare nFe particles is rapidly transformed into a thicker oxy-hydroxide layer that has a greater ability to adsorb molecular ions or ionic biomolecules like proteins or DNA.

  14. Heat and Mass Transfer Effects on Unsteady MHD Natural Convection Flow of a Chemically Reactive and Radiating Fluid through a Porous Medium Past a Moving Vertical Plate with Arbitrary Ramped Temperature

    Directory of Open Access Journals (Sweden)

    Gauri Shanker Seth

    2016-01-01

    Full Text Available Investigation of unsteady hydromagnetic natural convection flow with heat and mass transfer of a viscous, incompressible, electrically conducting, chemically reactive and optically thin radiating fluid past an exponentially accelerated moving vertical plate with arbitrary ramped temperature embedded in a fluid saturated porous medium is carried out. Exact solutions of momentum, energy and concentration equations are obtained in closed form by Laplace transform technique. The expressions for the shear stress, rate of heat transfer and rate of mass transfer at the plate for both ramped temperature and isothermal plates are derived. The numerical values of fluid velocity, fluid temperature and species concentration are displayed graphically whereas those of shear stress, rate of heat transfer and rate of mass transfer at the plate are presented in tabular form for various values of pertinent flow parameters. It is found that, for isothermal plate, the fluid temperature approaches steady state when t  1.5 . Consequently, the rate of heat transfer at isothermal plate approaches steady state when t  1.5 .

  15. Improved analysis of picomole quantities of lithium, sodium, and potassium in biological fluids.

    Science.gov (United States)

    Shalmi, M; Kibble, J D; Day, J P; Christensen, P; Atherton, J C

    1994-10-01

    The analysis of picomolar lithium, sodium, and potassium by electrothermal atomic absorption spectrophotometry was studied using a Perkin-Elmer Zeeman 3030 spectrophotometer. With ordinary pyrolytically coated graphite tubes, a number of interference effects associated with the sample matrix were observed. In particular, the lithium and potassium absorbance signal was depressed by chloride, an effect shown to be dependent on the preatomization heating. When an in situ tantalum-coated atomization surface was used, matrix interferences observed in lithium and potassium analyses were abolished, and the linear range for the potassium assay was extended. Technical difficulties encountered during sodium analysis at the primary wavelength were effectively circumvented by analysis at a less-sensitive wavelength (303.3 nm), at which tantalum coating also prevented significant chloride interference. The improved microanalyses were employed to reevaluate the handling of lithium, sodium, and potassium along the proximal convoluted tubule (PCT) of the anesthetized rat. The average tubular fluid-to-plasma concentration ratios for lithium [(TF/P)Li] and sodium [(TF/P)Na] were 1.13 +/- 0.08, n = 26, and 0.99 +/- 0.07 (n = 26), respectively. The tubular fluid-to-plasma ultrafiltrate concentration ratio for potassium [(TF/UF)K] was 1.09 +/- 0.05 (n = 13). Ratios did not change significantly with puncture site along the PCT for any of the ions. (TF/P)Li and (TF/UF)K were significantly greater than (TF/P)Na, indicating that lithium and potassium reabsorption do not directly parallel sodium reabsorption in the PCT. PMID:7943365

  16. Interaction of uranium(VI) with bioligands present in human biological fluids. The case study of urea and uric acid

    International Nuclear Information System (INIS)

    The complexation of uranium(VI) with bioligands found in human biological fluids, viz, urea and uric acid in aqueous solutions, has been investigated using time-resolved laser-induced fluorescence spectroscopy (TRLFS) at room temperature, I = 0.1 M (NaClO4) and pH (3 for uric acid; 4 for urea). In both complex systems a static quench effect with increasing ligand concentration and no peaks shift upon complexation were observed. With uranium(VI) both ligands formed a fairly weak 1:1 complex with average stability constants of log β110 = 4.67 ± 0.29 for uric acid and log β110 = 3.79 ± 0.15 and 2.12 ± 0.18 for relatively low and relatively high urea concentrations, respectively. Application of the newly generated data on the U(VI) speciation modelling in biofluids, e.g., human urine was also discussed.

  17. High-performance liquid chromatographic assay for acetaminophen and phenacetin in the presence of their metabolites in biological fluids

    International Nuclear Information System (INIS)

    The authors propose a method in which tracer amounts of a radiolabeled compound are used as the internal standard for the same unlabeled compound in high-performance liquid chromatography. The approach is valuable when a response from the internal standard becomes undesirable due to the presence of interference by the metabolites. The authors tested their approach with phenacetin and its metabolites, 2-hydroxyphenacetin, N-hydroxyphenacetin, phenetidine, acetaminophen sulfate conjugate and acetaminophen glucuronide conjugate in biological fluids with the use of [14C] phenacetin and [3H] acetaminophen as the internal standards, and were able to quantitate both phenacetin and acetaminophen simultaneously. They also tested the alternative approach in which the unlabeled drug was used as internal standard for tracer amounts of the same radiolabeled compound, with phenacetin and acetaminophen as the internal standards for tracer amounts of [14C] phenacetin and [3H] acetaminophen. Again, they were able to quantiate the two tracer radiolabeled compounds simultaneously. (Auth.)

  18. Supercritical fluid carbon dioxide extraction and liquid chromatographic separation with electrochemical detection of methylmercury from biological samples

    Science.gov (United States)

    Simon, N.S.

    1997-01-01

    Using the coupled methods presented in this paper, methylmercury can be accurately and rapidly extracted from biological samples by modified supercritical fluid carbon dioxide and quantitated using liquid chromatography with reductive electrochemical detection. Supercritical fluid carbon dioxide modified with methanol effectively extracts underivatized methylmercury from certified reference materials Dorm-1 (dogfish muscle) and Dolt-2 (dogfish liver). Calcium chloride and water, with a ratio of 5:2 (by weight), provide the acid environment required for extracting methylmercury from sample matrices. Methylmercury chloride is separated from other organomercury chloride compounds using HPLC. The acidic eluent, containing 0.06 mol L-1 NaCl, insures the presence of methylmercury chloride and facilitates the reduction of mercury on a glassy carbon electrode. If dual glassy carbon electrodes are used, a positive peak is observed at -0.65 to -0.70 V and a negative peak is observed at -0.90V with the organomercury compounds that were tested. The practical detection limit for methylmercury is 5 X 10-8 mol L-1 (1 X 10-12 tool injected) when a 20 ??L injection loop is used.

  19. Heat and mass transfer in MHD unsteady free convective flow of a micro polar fluid over a vertical moving porous plate embedded in a porous medium in the presence of thermal radiation

    International Nuclear Information System (INIS)

    An analysis is presented for the problem of heat and mass transfer in unsteady free convection flow of a micropolar viscous incompressible electrically conducting fluid over a vertical moving porous non-conducting plate embedded in porous medium in the presence of transverse magnetic field and thermal radiation with time varying suction velocity. The plate moves with constant velocity in the longitudinal direction, and the free stream velocity follows an exponentially small perturbation law. In addition, the coefficient of skin- friction and rate of heat transfer in terms of Nusselt number at the plate are also derived, discussed, and their numerical values for the various values of physical parameters are presented through table. (author)

  20. Sensitive determination of domperidone in biological fluids using a conductive polymer modified glassy carbon electrode

    International Nuclear Information System (INIS)

    A simple and sensitive method for domperidone (DP) determination has been developed by electropolymerizing a polymer film on the surface of glassy carbon electrode (GCE) in acidic solution using cyclic voltammetry. The modified sensor was characterized by Field Emission Scanning Electron Microscopy (FE-SEM) and Electrochemical Impedance Spectroscopy (EIS). The electrochemical measurements were carried out using square wave voltammetry and cyclic voltammetry. The modified sensor exhibited an excellent catalytic response towards the oxidation of DP with a well-defined oxidation peak at 840 mV. The modified sensor exhibited linear calibration curve for DP over a concentration range of 0.1 μM to 100 μM in phosphate buffer solution of pH 7.2 with detection limit of 12.0 nM. The sensor was capable to determine DP effectively without any interference from the common metabolites like ascorbic acid, uric acid, xanthine and hypoxanthine. The analytical utilities of the sensor have been demonstrated by determining the DP in human fluids and pharmaceutical samples. Further, the modified sensor displayed voltammetric responses with high sensitivity, good selectivity and reproducibility which make it suitable for clinical diagnosis

  1. Analytical Strategies for the Determination of Norepinephrine Reuptake Inhibitors in Pharmaceutical Formulations and Biological Fluids.

    Science.gov (United States)

    Saka, Cafer

    2016-01-01

    Norepinephrine reuptake inhibitors (NRIs) are a class of antidepressant drugs that act as reuptake inhibitors for the neurotransmitters norepinephrine and epinephrine. The present review provides an account of analytical methods published in recent years for the determination of NRI drugs. NRIs are atomoxetine, reboxetine, viloxazine and maprotiline. NRIs with less activity at other sites are mazindol, bupropion, tapentadol, and teniloxazine. This review focuses on the analytical methods including chromatographic, spectrophotometric, electroanalytical, and electrophoresis techniques for NRI analysis from pharmaceutical formulations and biological samples. Among all of the published methods, liquid chromatography with UV-vis or MS-MS detection is the most popular technique. The most the common sample preparation techniques in the analytical methods for NRIs include liquid-liquid extraction and solid-phase extraction. Besides the analytical methods for single components, some of the simultaneous determinations are also included in this review. PMID:26857446

  2. Corrosion resistance of titanium and some dental implant alloy in biological fluids

    International Nuclear Information System (INIS)

    The main purpose of this paper is the study of the long-term corrosion resistance of the titanium and dental alloy Ti-5Al-4V in physiological serum and artificial saliva of different pH values (acid and neutral) at 37 deg. C, reproducing the various biological environments that can be in contact with dental implants. The potentiostatic, potentiodynamic and linear polarisation measurements have been used to characterise the corrosion resistance of these materials during a period of about 1500 exposure hours. Also, the variation of open circuit potentials in time and with pH has been recorded for the same term. The potential gradients resulted from the pH changes were calculated; also, their variation in time were simulated for extreme, hypothetical conditions. The corrosion rates were determined. (authors)

  3. Stirring a fluid at low Reynolds numbers: Hydrodynamic collective effects of active proteins in biological cells

    Science.gov (United States)

    Kapral, Raymond; Mikhailov, Alexander S.

    2016-04-01

    Most of the proteins in the cell, including not only molecular motors and machines, but also enzymes, are active. When ATP or other substrates are supplied, these macromolecules cyclically change their conformations. Therefore, they mechanically stir the cytoplasm and nucleoplasm, so that non-thermal fluctuating flows are produced. As we have recently shown (Mikhailov and Kapral, 2015), stochastic advection by such flows might lead to substantial diffusion enhancement of particles inside a living cell. Additionally, when gradients in the concentrations of active particles or in the ATP/substrate supply are present, chemotaxis-like drift should take place. Here, the motion of passive tracers with various sizes in a mixture of different kinds of active proteins is analyzed. Moreover, effects of hydrodynamic interactions on the motion of active proteins are explored. Theoretical results are compared with available experimental data for ATP-dependent diffusion of natural and microinjected particles in biological cells.

  4. Supercritical fluid extraction and ultra performance liquid chromatography of respiratory quinones for microbial community analysis in environmental and biological samples.

    Science.gov (United States)

    Hanif, Muhammad; Atsuta, Yoichi; Fujie, Koichi; Daimon, Hiroyuki

    2012-01-01

    Microbial community structure plays a significant role in environmental assessment and animal health management. The development of a superior analytical strategy for the characterization of microbial community structure is an ongoing challenge. In this study, we developed an effective supercritical fluid extraction (SFE) and ultra performance liquid chromatography (UPLC) method for the analysis of bacterial respiratory quinones (RQ) in environmental and biological samples. RQ profile analysis is one of the most widely used culture-independent tools for characterizing microbial community structure. A UPLC equipped with a photo diode array (PDA) detector was successfully applied to the simultaneous determination of ubiquinones (UQ) and menaquinones (MK) without tedious pretreatment. Supercritical carbon dioxide (scCO(2)) extraction with the solid-phase cartridge trap proved to be a more effective and rapid method for extracting respiratory quinones, compared to a conventional organic solvent extraction method. This methodology leads to a successful analytical procedure that involves a significant reduction in the complexity and sample preparation time. Application of the optimized methodology to characterize microbial communities based on the RQ profile was demonstrated for a variety of environmental samples (activated sludge, digested sludge, and compost) and biological samples (swine and Japanese quail feces). PMID:22391598

  5. Supercritical Fluid Extraction and Ultra Performance Liquid Chromatography of Respiratory Quinones for Microbial Community Analysis in Environmental and Biological Samples

    Directory of Open Access Journals (Sweden)

    Koichi Fujie

    2012-03-01

    Full Text Available Microbial community structure plays a significant role in environmental assessment and animal health management. The development of a superior analytical strategy for the characterization of microbial community structure is an ongoing challenge. In this study, we developed an effective supercritical fluid extraction (SFE and ultra performance liquid chromatography (UPLC method for the analysis of bacterial respiratory quinones (RQ in environmental and biological samples. RQ profile analysis is one of the most widely used culture-independent tools for characterizing microbial community structure. A UPLC equipped with a photo diode array (PDA detector was successfully applied to the simultaneous determination of ubiquinones (UQ and menaquinones (MK without tedious pretreatment. Supercritical carbon dioxide (scCO2 extraction with the solid-phase cartridge trap proved to be a more effective and rapid method for extracting respiratory quinones, compared to a conventional organic solvent extraction method. This methodology leads to a successful analytical procedure that involves a significant reduction in the complexity and sample preparation time. Application of the optimized methodology to characterize microbial communities based on the RQ profile was demonstrated for a variety of environmental samples (activated sludge, digested sludge, and compost and biological samples (swine and Japanese quail feces.

  6. Geochemistry of pore-fluids related to the distribution of the biological communities on the giant Regab pockmark, off Gabon

    Science.gov (United States)

    de Prunelé, A.; Caprais, J.; Ruffine, L.; Cassarino, L.; Guyader, V.; Bollinger, C.; Ondréas, H.; Donval, J.; Olu, K.; Geli, L. B.; Cunningham, K. L.; Cauquil, E.

    2013-12-01

    The Regab pockmark is a giant structure located at 3200 m water depth offshore Gabon and ~ 10 km north to the deep Congo channel (Zaïre canyon) (Gay et al. 2006; Ondréas et al. 2005). It has been visited for the first time in 2000 during the Zairov cruise. Since that time, several scientific cruises have allowed further investigations of this pockmark. The last cruise, WACS, for West Africa Cold Seeps, in January- February 2010, was undertaken on board the R/V ';Pourquoi Pas?' with the aim of identifying changes which can occur over time on this pockmark. Besides intensive ROV dives, three calypso cores and several push cores have been collected to better understand the relationships between the distribution of the living communities and the pore-fluids chemistry. In two calypso cores one collected within the pockmark and one outside, and both in areas without visible biological communities, pore-fluids profiles of dissolved elements (Alk, SO42-, Mn2+, Fe2+) show that degradation of organic matter is occurring and likely plays an important role in the sulfate reduction (Froelich et al. 1979). Methane was not detected. The Analysis of the pore-fluids by Thermal Desorption-Gas Chromatography-Mass Spectrometry (TD-GC-MS) has shown the presence of alcohols, acid and phenol. These molecules are likely related to the degradation of organic matter and/or the production of the biological communities. Further investigations are ongoing to provide us with a clearer picture regarding the source of these molecules. The third calypso core collected in the northeast part of the pockmark containing gas hydrates. Sulfate profiles from the push cores show significant difference from one community to another. The analyses of both major and minor dissolved elements, along with molecular and isotopic methane concentration measurements are in progress for the push cores. The latter was done using a new analyzer G2201-i from Picarro for which new methods applied to pore-fluids has

  7. [Determination of ethylene glycol in biological fluids--propylene glycol interferences].

    Science.gov (United States)

    Gomółka, Ewa; Cudzich-Czop, Sylwia; Sulka, Adrianna

    2013-01-01

    Many laboratories in Poland do not use gas chromatography (GC) method for determination of ethylene glycol (EG) and methanol in blood of poisoned patients, they use non specific spectrophotometry methods. One of the interfering substances is propylene glycol (PG)--compound present in many medical and cosmetic products: drops, air freshens, disinfectants, electronic cigarettes and others. In Laboratory of Analytical Toxicology and Drug Monitoring in Krakow determination of EG is made by GC method. The method enables to distinguish and make resolution of (EG) and (PG) in biological samples. In the years 2011-2012 in several serum samples from diagnosed patients PG was present in concentration from several to higher than 100 mg/dL. The aim of the study was to estimate PG interferences of serum EG determination by spectrophotometry method. Serum samples containing PG and EG were used in the study. The samples were analyzed by two methods: GC and spectrophotometry. Results of serum samples spiked with PG with no EG analysed by spectrophotometry method were improper ("false positive"). The results were correlated to PG concentration in samples. Calculated cross-reactivity of PG in the method was 42%. Positive results of EG measured by spectrophotometry method must be confirmed by reference GC method. Spectrophotometry method shouldn't be used for diagnostics and monitoring of patients poisoned by EG. PMID:24466683

  8. The two coupling fluids method for ultrasonic velocity measurement. Application to biological tissues

    International Nuclear Information System (INIS)

    Measuring the ultrasonic velocity in soft materials, especially in biological tissues, is never easy. One of the main issues is that the thickness of the sample under test is badly defined. From the time-of-flight measurement method, uncertainties in the thickness induce important uncertainties in experimental results. This implies that the ultrasonic velocity is often a poor criterion when it could be a good one. This paper introduces a new method to measure the ultrasonic velocity in soft materials without knowing the sample thickness The main idea of this method is to use two different coupling media to make two relative time-of-flight measurements. The comparison of these two measurements gives the ultrasonic velocity in the sample under test. Furthermore, this comparison can give the local thickness of the sample. The uncertainty calculations show that the effect on the thickness is drastically reduced by using this new ultrasound method. This method is validated on a reference sample (silicone). Before conclusion, some experimental results obtained with mouse skin samples are presented

  9. Methods of biological fluids sample preparation - biogenic amines, methylxanthines, water-soluble vitamins.

    Science.gov (United States)

    Płonka, Joanna

    2015-01-01

    In recent years demands on the amount of information that can be obtained from the analysis of a single sample have increased. For time and economic reasons it is necessary to examine at the same time larger number of compounds, and compounds from different groups. This can best be seen in such areas as clinical analysis. In many diseases, the best results for patients are obtained when treatment fits the individual characteristics of the patient. Dosage monitoring is important at the beginning of therapy and in the full process of treatment. In the treatment of many diseases biogenic amines (dopamine, serotonin) and methylxanthines (theophylline, theobromine, caffeine) play an important role. They are used as drugs separately or in combination with others to support and strengthen the action of other drugs - for example, the combination of caffeine and paracetamol. Vitamin supplementation may be also an integral part of the treatment process. Specification of complete sample preparation parameters for extraction of the above compounds from biological matrices has been reviewed. Particular attention was given to the preparation stage and extraction methods. This review provides universal guidance on establishing a common procedures across laboratories to facilitate the preparation and analysis of all discussed compounds. PMID:25381720

  10. Enantioselective separation of biologically active basic compounds in ultra-performance supercritical fluid chromatography.

    Science.gov (United States)

    Geryk, Radim; Kalíková, Květa; Schmid, Martin G; Tesařová, Eva

    2016-08-17

    The enantioseparation of basic compounds represent a challenging task in modern SFC. Therefore this work is focused on development and optimization of fast SFC methods suitable for enantioseparation of 27 biologically active basic compounds of various structures. The influences of the co-solvent type as well as different mobile phase additives on retention, enantioselectivity and enantioresolution were investigated. Obtained results confirmed that the mobile phase additives, especially bases (or the mixture of base and acid), improve peak shape and enhance enantioresolution. The best results were achieved with isopropylamine or the mixture of isopropylamine and trifluoroacetic acid as additives. In addition, the effect of temperature and back pressure were evaluated to optimize the enantioseparation process. The immobilized amylose-based chiral stationary phase, i.e. tris(3,5-dimethylphenylcarbamate) derivative of amylose proved to be useful tool for the enantioseparation of a broad spectrum of chiral bases. The chromatographic conditions that yielded baseline enantioseparations of all tested compounds were discovered. The presented work can serve as a guide for simplifying the method development for enantioseparation of basic racemates in SFC. PMID:27286774

  11. Move up,Move out

    Institute of Scientific and Technical Information of China (English)

    Guo Yan

    2007-01-01

    @@ China has already become the world's largest manufacturer of cement,copper and steel.Chinese producers have moved onto the world stage and dominated the global consumer market from textiles to electronics with amazing speed and efficiency.

  12. Determination of four sulfated vitamin D compounds in human biological fluids by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Gomes, Fabio P; Shaw, P Nicholas; Hewavitharana, Amitha K

    2016-01-15

    The determination of both the water-soluble and lipid-soluble vitamin D compounds in human biological fluids is necessary to illuminate potentially significant biochemical mechanisms. The lack of analytical methods to quantify the water-soluble forms precludes studies on their role and biological functions; currently available liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods are able to determine only a single sulfated form of Vitamin D. We describe here a highly sensitive and specific LC-MS/MS method for the quantification of four sulfated forms of vitamin D: vitamins D2- and D3-sulfate (D2-S and D3-S) and 25-hydroxyvitamin D2- and D3-sulfate (25(OH)D2-S and 25(OH)D3-S). A comparative evaluation showed that the ionization efficiencies of underivatized forms in negative ion mode electrospray ionisation (ESI) are superior to those of the derivatized (using 4-phenyl-l,2,4-triazoline-3,5-dione (PTAD)) forms in positive ion mode ESI. Separation was optimised to minimise co-elution with endogenous matrix compounds, thereby reducing ion suppression/enhancement effects. Isotopically labelled analogues of each compound were used as internal standards to correct for ion suppression/enhancement effects. The method was validated and then applied for the analysis of breastmilk and human serum. The detection limits, repeatability standard deviations, and recoveries ranged from 0.20 to 0.28fmol, 2.8 to 10.2%, and 81.1 to 102%, respectively. PMID:26708628

  13. Pilot Scale Test to Treat High Concentration Gasification Wastewater Using Catalytic Oxidation and Aerobic Biological Fluid-Bed Combination Process

    Institute of Scientific and Technical Information of China (English)

    LI Na; HUANG Jun-li; WANG Wei; ZHAO Jian-wei; WANG Cui-lin; CUI Chong-wei

    2008-01-01

    The gasitication wastewatet is a kind of typical ocgauic industrial wastewatet with high chemical oxygen demand (COD) and ammonia uitrogen,which could not be completely degraded by the traditional physical,chimical and bidogical method.So it is very important to find an effective treatment process.A combination process of catalytic oxidation with noble metal catalysts and aerobic biological fluid-bed packed with the new uitrastructure biological carriers,which was devdoped by ourselves,was investigated to treat the gasification wastcwater.The pilot scale test with 0.5m3/h influent flow was carried out to investigate the performance of this new combination process.The results showed that the effluent COD was 84.02 mg/L,ananonia nitrogen was 14.15 mg/L,and total phenol was 0.20 mg/L,which could completely meet the Grade I of Wastewater Discharge Standard (GB8978-1996),when the influent average COD was 5564 mg/L,anunonia nitrogen was 237 mg/L,and total phenol was 1100 mg/L.The two catalytic reactors could evidently improve the wastewater biodegradability,and the value of BOD5/COD(B/C) increased from 0.23 to 0.413 in the one-stage catalytic reactor and from 0.273 to 0.421 in two-stage catalytic reactor.The further experiment results showed that the effluent quality of this new combination progess could still meet the discharge standard,aromatic and heterocyclic compounds were degraded effectively in this combination process.

  14. Spectrofluorimetric method for quantification of citalopram in pharmaceutical preparations and biological fluids through oxidation with Ce(IV)

    Science.gov (United States)

    Shah, Jasmin; Jan, M. Rasul; Khan, M. Naeem; Inayatullah

    2013-01-01

    A sensitive and simple spectrofluorimetric method for the quantification of citalopram in a pure form, in pharmaceutical preparations, and in human blood plasma and urine has been described. The proposed method was based on the oxidation of citalopram by Ce(IV) in acidic media to produce fluorescent Ce(III), and on the subsequent measurement of its fluorescence intensity at 353 nm after excitation at 252 nm. All variables affecting the oxidation of citalopram such as Ce(IV) concentration, the type and concentration of acid, temperature and heating time were studied and optimized. Under the optimized experimental conditions the linear range of concentration versus fluorescence intensity was found to lie between 0.02 and 1.4 g/ml. Limits of detection and quantification were determined to be 6.9·10-3 g/ml and 2.3·10-2 g/ml respectively. Effects of excipients commonly used in the quantification of citalopram have been studied and no interferences were found. The proposed method was successfully applied to determine citalopram in pure form, in pharmaceutical preparations, and in biological fluids. Good recoveries in the ranges of 95.31-101.67%, 88.50-96.67%, and 90.0-96.67% were obtained for the pharmaceutical preparations (tablets), blood plasma, and human urine respectively.

  15. Electrochemical oxidation behavior of hydrochlorothiazide on a glassy carbon electrode and its voltammetric determination in pharmaceutical formulations and biological fluids

    Directory of Open Access Journals (Sweden)

    Ali F. Alghamdi

    2014-09-01

    Full Text Available The electrochemical oxidation behavior of hydrochlorothiazide (HCT on a glassy carbon as a working electrode was investigated in Britton–Robinson (B–R buffer pH 3, by using anodic stripping voltammetry (ASV and cyclic voltammetry (CV. This drug gave a well-defined voltammetric oxidation peak at + 1200 mV versus an Ag/AgCl reference electrode. The electrochemical oxidation process was shown to be irreversible and diffusion controlled, with adsorption characterized over the entire pH range. The optimized conditions, such as accumulation time and potential, scan rate, frequency, pulse amplitude, varying of working electrodes, and instrumental parameters were studied. The calibration graph for HCT was obtained from 4 × 10−6 to 4 × 10−5 M (correlation coefficient = 0.997 using the developed electroanalytical method (ASV. The detection limit of this drug was 4.3 × 10−9 M. ASV and CV techniques with adequate precision and accuracy have been developed and applied for direct determination of HCT in commercial tablets without separation or extraction procedures and biological fluids such as urine and plasma.

  16. Biologic

    CERN Document Server

    Kauffman, L H

    2002-01-01

    In this paper we explore the boundary between biology and the study of formal systems (logic). In the end, we arrive at a summary formalism, a chapter in "boundary mathematics" where there are not only containers but also extainers ><, entities open to interaction and distinguishing the space that they are not. The boundary algebra of containers and extainers is to biologic what boolean algebra is to classical logic. We show how this formalism encompasses significant parts of the logic of DNA replication, the Dirac formalism for quantum mechanics, formalisms for protein folding and the basic structure of the Temperley Lieb algebra at the foundations of topological invariants of knots and links.

  17. Theory of locomotion through complex fluids

    CERN Document Server

    Elfring, Gwynn

    2014-01-01

    Microorganisms such as bacteria often swim in fluid environments that cannot be classified as Newtonian. Many biological fluids contain polymers or other heterogeneities which may yield complex rheology. For a given set of boundary conditions on a moving organism, flows can be substantially different in complex fluids, while non-Newtonian stresses can alter the gait of the microorganisms themselves. Heterogeneities in the fluid may also be characterized by length scales on the order of the organism itself leading to additional dynamic complexity. In this chapter we present a theoretical overview of small-scale locomotion in complex fluids with a focus on recent efforts quantifying the impact of non-Newtonian rheology on swimming microorganisms.

  18. Characterisation by PIXE method of trace elements during physico-chemical reactions at the periphery of bioactive glass pastilles in contact with biological fluids

    OpenAIRE

    Jallot, Edouard; Moretto, P.

    2005-01-01

    The prerequisite for bioactive glasses to bond to living bone is the formation of biologically active apatites on their surface in the body. Reactions and bioactivity mechanisms between bioactive glasses and bone depend on the glass composition. We study a glass in the SiO2-Na2O-CaO-P2O5-K2O-Al2O3-MgO system. To characterise physico-chemical reactions at the materials periphery, we immersed the glass pastilles into biological fluids for delays of 5, 10 and 20 days. The surface changes were st...

  19. MULTI-ANALYTE DETECTION FOR BIOLOGICAL FLUIDS Towards Continous Monitoring of Glucose, Ionized Calcium and pH using a Viscometric Affinity Biosensor

    OpenAIRE

    Boss, Christophe; Meurville, Eric; Ryser, Peter; Schmitt, Frédéric; Juillerat-Jeanneret, Lucienne; Dosil-Rosende, Pablo; De Souza, Desdemona

    2011-01-01

    We present a viscometric affinity biosensor that can potentially allow continuous multi-analyte monitoring in biological fluids like blood or plasma. The sensing principle is based on the detection of viscosity changes of a polymeric solution which has a selective affinity for the analyte of interest. The chemico-mechanical sensor incorporates an actuating piezoelectric diaphragm, a sensing piezoelectric diaphragm and a flow-resisting microchannel for viscosity detection. A free-standing Anod...

  20. Micropropulsion and microrheology in complex fluids via symmetry breaking

    CERN Document Server

    Pak, On Shun; Brandt, Luca; Lauga, Eric; 10.1063/1.4758811

    2013-01-01

    Many biological fluids have polymeric microstructures and display non-Newtonian rheology. We take advantage of such nonlinear fluid behavior and combine it with geometrical symmetry-breaking to design a novel small-scale propeller able to move only in complex fluids. Its propulsion characteristics are explored numerically in an Oldroyd-B fluid for finite Deborah numbers while the small Deborah number limit is investigated analytically using a second-order fluid model. We then derive expressions relating the propulsion speed to the rheological properties of the complex fluid, allowing thus to infer the normal stress coefficients in the fluid from the locomotion of the propeller. Our simple mechanism can therefore be used either as a non-Newtonian micro-propeller or as a micro-rheometer.

  1. Engineering fluid flow using sequenced microstructures

    Science.gov (United States)

    Amini, Hamed; Sollier, Elodie; Masaeli, Mahdokht; Xie, Yu; Ganapathysubramanian, Baskar; Stone, Howard A.; di Carlo, Dino

    2013-05-01

    Controlling the shape of fluid streams is important across scales: from industrial processing to control of biomolecular interactions. Previous approaches to control fluid streams have focused mainly on creating chaotic flows to enhance mixing. Here we develop an approach to apply order using sequences of fluid transformations rather than enhancing chaos. We investigate the inertial flow deformations around a library of single cylindrical pillars within a microfluidic channel and assemble these net fluid transformations to engineer fluid streams. As these transformations provide a deterministic mapping of fluid elements from upstream to downstream of a pillar, we can sequentially arrange pillars to apply the associated nested maps and, therefore, create complex fluid structures without additional numerical simulation. To show the range of capabilities, we present sequences that sculpt the cross-sectional shape of a stream into complex geometries, move and split a fluid stream, perform solution exchange and achieve particle separation. A general strategy to engineer fluid streams into a broad class of defined configurations in which the complexity of the nonlinear equations of fluid motion are abstracted from the user is a first step to programming streams of any desired shape, which would be useful for biological, chemical and materials automation.

  2. Restricted access magnetic materials prepared by dual surface modification for selective extraction of therapeutic drugs from biological fluids

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yu; Wang Yuxia; Chen Lei [School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072 (China); Wan Qianhong, E-mail: qhwan@tju.edu.cn [School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072 (China)

    2012-02-15

    Magnetic porous particles with dual functionality have been prepared by a two-step procedure and evaluated as novel restricted access materials for extraction of therapeutic agents from biological fluids. The magnetic silica particles served as scaffolds were first modified with diol groups, which were then converted to octadecyl esters through reaction with stearoyl chloride. In the second step, the octadecyl esters on the exterior surface were hydrolyzed by the action of lipase to yield magnetic particles with hydrophobic reversed-phase ligands on the inner surface and biocompatible diol groups on the outer surface. The restricted access behavior of the resulting materials was confirmed by differential binding of small molecules such as methotrexate (MTX), leucovorin (LV) and folic acid (FA) relative to bovine serum albumin. While MTX, LV and FA were all bound to the magnetic particles with high affinity, the adsorption of the protein was markedly reduced due to size exclusion effect. The utility of the magnetic particles for sample preparation was tested in solid-phase extraction of MTX, LV and FA from spiked human serum and the effects of the SPE conditions on the recovery of the analytes were systematically studied. Moreover, the magnetic particle-based sample preparation procedure coupled with reversed-phase liquid chromatography analysis was validated in terms of specificity, linearity and reproducibility. The method was shown to be free from interference of endogenous compounds and linear over the concentration range of 0.5-10 {mu}g/mL for the three drugs studied. The limits of detection for the three drugs in serum were in the range of 0.160-0.302 {mu}g/mL. Reproducibility expressed as the RSD of the recovery for ten replicated extractions at three different concentrations was found to be less than 8.93%. With a unique combination of surface functionality with magnetic cores, the restricted access magnetic particles may be adapted in automated and high

  3. Laser Doppler instrument measures fluid velocity without reference beam

    Science.gov (United States)

    Bourquin, K. R.; Shigemoto, F. H.

    1971-01-01

    Fluid velocity is measured by focusing laser beam on moving fluid and measuring Doppler shift in frequency which results when radiation is scattered by particles either originally present or deliberately injected into moving fluid.

  4. Elimination and Concentration Correlations between Edible Tissues and Biological Fluids and Hair of Ractopamine in Pigs and Goats Fed with Ractopamine-Medicated Feed.

    Science.gov (United States)

    Huang, Lingli; Shi, Jingfei; Pan, Yuanhu; Wang, Liye; Chen, Dongmei; Xie, Shuyu; Liu, Zhenli; Yuan, Zonghui

    2016-03-01

    Ractopamine (RAC), a β-adrenergic leanness-enhancing agent, endangers the food safety of animal products because of overdosing and illegal use in food animals. Excretion and residue depletion of RAC in pigs and goats were investigated to determine a representative biological fluid or surface tissue for preslaughter monitoring. After a single oral gavage of RAC, 64-67% of the dose was excreted from the urine of pigs and goats within 12-24 h. RAC persisted the longest in the hair of pigs and goats but depleted rapidly in the plasma, muscle, and fat. Urine and hair were excellent for predicting RAC residues in edible tissues of pigs, whereas plasma and urine were satisfactory body fluids for the prediction of RAC concentrations in edible tissues of goats. These data provided a simple and economical preslaughter living monitoring method for the illegal use and violative residue of RAC in food animals. PMID:26883087

  5. Design of a Flow-through Polarographic Sensor Based on Metal Films for Determining N-nitrosodiethanolamine Levels in Rabbit Biological Fluids

    Directory of Open Access Journals (Sweden)

    Yuan-Zhi Lan

    2006-11-01

    Full Text Available The construction and characterization of a flow-through polarographic detectorfor catalyzing the electroreduction of N-nitrosodiethanolamine (NDELA, is discussed. Theflow-through cell is equipped with a gold wire electrode (a thin mercury film deposited on agold substance. The response is evaluated with respect to substance diameter, length,concentration of modifying film, operating potential, supporting electrolyte and pH, andflow rate in the DC mode. The system allows the determination of N-nitrosodiethanolaminein rabbit biological fluids with relatively inexpensive equipment.

  6. On the atmosphere of a moving body

    DEFF Research Database (Denmark)

    Pedersen, Johan Rønby; Aref, Hassan

    2010-01-01

    We explore whether a rigid body moving freely with no circulation around it in a two-dimensional ideal fluid can carry a fluid "atmosphere" with it in its motion. Somewhat surprisingly, the answer appears to be "yes." When the body is elongated and the motion is dominated by rotation, we demonstr......We explore whether a rigid body moving freely with no circulation around it in a two-dimensional ideal fluid can carry a fluid "atmosphere" with it in its motion. Somewhat surprisingly, the answer appears to be "yes." When the body is elongated and the motion is dominated by rotation, we...... demonstrate numerically that, indeed, regions of fluid follow the body in its motion. We see this as an example of the stability of Kolmogorov-Arnold-Moser tori. These observations of an atmosphere around a moving body with no circulation around it appear to be new. (C) 2010 American Institute of Physics...

  7. Dispersion of hydrophobic magnetic nanoparticles using ultarsonic-assisted in combination with coacervative microextraction for the simultaneous preconcentration and determination of tricyclic antidepressant drugs in biological fluids.

    Science.gov (United States)

    Jannesar, Ramin; Zare, Fahimeh; Ghaedi, Mehrorang; Daneshfar, Ali

    2016-09-01

    A two-step sample preparation technique based on dispersive micro solid-phase extraction combined with coacervative microextraction is presented for preconcentration and determination of tricyclic antidepressant drugs in biological samples. An important feature of the method is the application of hydrophobic magnetic nanoparticles, which in combination with coacervative microextraction method enables development of rapid and efficient extraction procedure in order to achievement of a high extraction efficiency. Simultaneous optimization by experimental design lead to improvement of method with low cost which supply useful information about interaction among variables. Under the optimized conditions, a linear range of 5-1000ngmL(-1) with detection limits from 0.51 to 1.4ngmL(-1) were obtained for target analytes. The method was successfully used for the determination of analytes in biological fluids (plasma and urine) with relative recoveries in the range of 89-105% (RSDs<3.5%). PMID:27150784

  8. Determination of antisense phosphorothioate oligonucleotides and catabolites in biological fluids and tissue extracts using anion-exchange high-performance liquid chromatography and capillary gel electrophoresis.

    Science.gov (United States)

    Chen, S H; Qian, M; Brennan, J M; Gallo, J M

    1997-04-25

    Chemically modified phosphorothioate oligodeoxynucleotides (ODNs) have become critical tools for research in the fields of gene expression and experimental therapeutics. Bioanalytical assays were developed that utilized fast anion-exchange high-performance liquid chromatography (HPLC) and capillary gel electrophoresis (CGE) for the determination of 20-mer ODNs in biological fluids (plasma and urine) and tissues. A 20 mer ODN in the antisense orientation directed against DNA methyltransferase (denoted as MT-AS) was studied as the model ODN. The anion-exchange HPLC method employed a short column packed with non-porous polymer support and a ternary gradient elution with 2 M lithium bromide containing 30% formamide. Analysis of the MT-AS is accomplished within 5 min with a detection limit of approximately 3 ng on-column at 267 nm. For plasma and urine, samples were diluted with Nonidet P-40 in 0.9% NaCl and directly injected onto the column, resulting in 100% recovery. For tissue homogenates, a protein kinase K digestion and phenol-chloroform extraction were used, with an average recovery of about 50%. Since the HPLC assay cannot provide one-base separation, biological samples were also processed by an anion-exchange solid-phase extraction and a CGE method to characterize MT-AS and its catabolites of 15-20-mer, species most relevant to biological activity. One base separation, under an electric field of 400 V/cm at room temperature, was achieved for a mixture of 15-20-mer with about 50 pg injected. Assay validation studies revealed that the combined HPLC-CGE methods are accurate, reproducible and specific for the determination of MT-AS and its catabolites in biological fluids and tissue homogenates, and can be used for the pharmacokinetic characterization of MT-AS. PMID:9187382

  9. Development of garlic bioactive compounds analytical methodology based on liquid phase microextraction using response surface design. Implications for dual analysis: Cooked and biological fluids samples.

    Science.gov (United States)

    Ramirez, Daniela Andrea; Locatelli, Daniela Ana; Torres-Palazzolo, Carolina Andrea; Altamirano, Jorgelina Cecilia; Camargo, Alejandra Beatriz

    2017-01-15

    Organosulphur compounds (OSCs) present in garlic (Allium sativum L.) are responsible of several biological properties. Functional foods researches indicate the importance of quantifying these compounds in food matrices and biological fluids. For this purpose, this paper introduces a novel methodology based on dispersive liquid-liquid microextraction (DLLME) coupled to high performance liquid chromatography with ultraviolet detector (HPLC-UV) for the extraction and determination of organosulphur compounds in different matrices. The target analytes were allicin, (E)- and (Z)-ajoene, 2-vinyl-4H-1,2-dithiin (2-VD), diallyl sulphide (DAS) and diallyl disulphide (DADS). The microextraction technique was optimized using an experimental design, and the analytical performance was evaluated under optimum conditions. The desirability function presented an optimal value for 600μL of chloroform as extraction solvent using acetonitrile as dispersant. The method proved to be reliable, precise and accurate. It was successfully applied to determine OSCs in cooked garlic samples as well as blood plasma and digestive fluids. PMID:27542503

  10. Estimation of the Patients' Adaptation to Noble Alloy Dentures Relying on the Parameters of Biological Fluids in Oral Cavities

    Institute of Scientific and Technical Information of China (English)

    LEBEDENKO I. Yu.; PARUNOV V. A.; KITKINA T. B.

    2012-01-01

    For the study of the effect of Plagodent and Palladent noble alloy dentures (OJSC "SIC ‘Supermetal’",Russia),the elemental compositions of the fluids obtained from gingival sulcus of abutment teeth of metal-ceramic dentures with frames made of the above-stated dental alloys,have been investigated.Response of white blood cells and fibroblasts in the gingival fluid and the mixed saliva of the patients a long time after prosthetic repair,relying on the content of proinflammatory interleukins IL-1 β and IL-6,anti-inflammatory interleukins IL-4 and IL-10,the factor of tumor necrosis TNF-α and lactoferrin,has been investigated.The results obtained have convincingly proved the biosafety of the Plagodent and Palladent noble alloys.

  11. Assay of amoxicillin and clavulanic acid, the components of Augmentin, in biological fluids with high-performance liquid chromatography.

    OpenAIRE

    Foulstone, M; Reading, C

    1982-01-01

    Augmentin is a new antibacterial formulation comprised of amoxicillin and the beta-lactamase inhibitor clavulanic acid. In the present paper, the use of high-performance liquid chromatography (HPLC) to provide a rapid assay of the components of Augmentin in body fluids is described. Clavulanic acid was assayed by reacting the sample with imidazole, which readily produces a derivative absorbing at 311 nm. This derivative chromatographs on reverse-phase HPLC columns clear of interfering compone...

  12. Mechanics of moving materials

    CERN Document Server

    Banichuk, Nikolay; Neittaanmäki, Pekka; Saksa, Tytti; Tuovinen, Tero

    2014-01-01

    This book deals with theoretical aspects of modelling the mechanical behaviour of manufacturing, processing, transportation or other systems in which the processed or supporting material is travelling through the system. Examples of such applications include paper making, transmission cables, band saws, printing presses, manufacturing of plastic films and sheets, and extrusion of aluminium foil, textiles and other materials.   The work focuses on out-of-plane dynamics and stability analysis for isotropic and orthotropic travelling elastic and viscoelastic materials, with and without fluid-structure interaction, using analytical and semi-analytical approaches.  Also topics such as fracturing and fatigue are discussed in the context of moving materials. The last part of the book deals with optimization problems involving physical constraints arising from the stability and fatigue analyses, including uncertainties in the parameters.   The book is intended for researchers and specialists in the field, providin...

  13. A Coupled Level Set and Volume of Fluid Method for Tracking Moving Interface in Multiphase Flow%基于CLSVOF方法的多介质流运动界面追踪

    Institute of Scientific and Technical Information of China (English)

    陈善群; 廖斌

    2012-01-01

    根据Level-Set方法和VOF方法各自的优缺点,耦合生成一种Level-Set和VOF的耦合界面追踪方法,简称CLSVOF(Coupled Level Set and Volume Of Fluid Method)方法.CLSVOF方法利用Level-Set函数计算VOF体积份额,克服了VOF方法难以准确计算界面的法向量和曲率的缺点;同时又利用VOF体积份额修正Level-Set函数,克服了Level-Set方法在计算过程中有物理量的损失的缺点.用旋转流场和剪切流场的数值算例验证了CLSVOF方法相比VOF方法提高了运动界面追踪的分辨率,相比Level-Set方法实现了计算过程中的物理量守恒.运用CLSVOF方法数值模拟了两个多介质流运动界面算例,分别是自由剪切层问题和气泡在静止水体中上升问题.对比数值模拟结果与理论分析和实验结果可知CLSVOF方法能精确地追踪多介质流运动界面.%Based on the advantages and disadvantages of the Level-Set method and the VOF method,a coupled Level-Set and Volume of Fluid (CLSVOF) method is presented.Through using the Level-Set function to computing volumetric fraction,CLSVOF method overcomes the disadvantage of the VOF method,which is the fact that it is difficult to obtain the normal vector and curvature accurately.Through using the VOF volumetric fraction to revise Level-Set function,CLSVOF method overcomes the drawback of the Level-Set method,which is mass loss in computational process.The numerical results of the applied cases validate that the CLSVOF method improves tracking resolution than the VOF method,as well as,realizes mass conservation compared with the Level-Set method.Furthermore,the CLSVOF method is applied to simulatetwo types of the movement interface in multiphase flow,which are free shear layer and a rising gas bubble in water,respectively.The numerical results are compared with theoretical analysis and experimental data.It is shown that the CLSVOF method can accurately track moving interface in multiphase flow.

  14. Application of Moving Bed Biofilm Reactor (MBBR) and Integrated Fixed Activated Sludge (IFAS) for Biological River Water Purification System: A Short Review

    Science.gov (United States)

    Lariyah, M. S.; Mohiyaden, H. A.; Hayder, G.; Hayder, G.; Hussein, A.; Basri, H.; Sabri, A. F.; Noh, MN

    2016-03-01

    This review paper present the MBBR and IFAS technology for urban river water purification including both conventional methods and new emerging technologies. The aim of this paper is to present the MBBR and IFAS technology as an alternative and successful method for treating different kinds of effluents under different condition. There are still current treatment technologies being researched and the outcomes maybe available in a while. The review also includes many relevant researches carried out at the laboratory and pilot scales. This review covers the important processes on MBBR and IFAS basic treatment process, affecting of carrier type and influent types. However, the research concluded so far are compiled herein and reported for the first time to acquire a better perspective and insight on the subject with a view of meeting the news approach. The research concluded so far are compiled herein and reported for the first time to acquire a better perspective and insight on the subject with a view of meeting the news approach. To this end, the most feasible technology could be the combination of advanced biological process (bioreactor systems) including MBBR and IFAS system.

  15. On the atmosphere of a moving body

    DEFF Research Database (Denmark)

    Pedersen, Johan Rønby; Aref, Hassan

    2010-01-01

    We have explored whether a rigid body moving freely with no circulation around it in a two-dimensional ideal fluid can carry a fluid ``atmosphere'' with it in its motion. Somewhat surprisingly, the answer appears to be ``yes''. When the body is elongated and the motion is dominated by rotation, we...... demonstrate numerically that, indeed, regions of fluid follow the body in its motion. Since there is a double-island structure for the case of pure rotation, as already found by Morton and Darwin many years ago, we see the existence of an atmosphere for the moving body as an example of the stability...

  16. The nanocrystalline coordination polymer of AMT-Ag for an effective detection of ciprofloxacin hydrochloride in pharmaceutical formulation and biological fluid.

    Science.gov (United States)

    Tiwari, Madhu; Kumar, Ashish; Shankar, Uma; Prakash, Rajiv

    2016-11-15

    The present report highlights a cost effective and portable AMT-Ag nanocrystalline coordination polymer (NCCP) based electrochemical sensor for an efficient sensing of biologically active drug molecule ciprofloxacin hydrochloride (CFX). The AMT-Ag NCCP, is synthesized using an easily accessible organic ligand 2-amino-5-mercapto-1,3,4-thiadiazole (AMT) with silver nitrate. In the infinite polymer array of AMT-Ag, silver (I) centers are bridged by tecton AMT through the exocyclic thiol and amino linkage. A successful ultra‒trace detection of CFX has been achieved due to the prominent electron channeling through the pores of polymeric nano-crystallites. The efficient charge transfer arises at the interface of electrolyte and AMT-Ag nano-crystals anchored electrode through hydrophobic interaction and π-π electron coupling. The voltammogram reveals the critical redox features of CFX and provides a clear representation about the steps involved in the AMT-Ag assisted oxidation of CFX. This specific signature further applied in the voltammetric assay of CFX in pharmaceutical formulation (eye drops) and biological fluid (urine) by a significantly high sensitivity (0.002µA/µM and 0.007µA/µM) and detection limit (22nM and 60nM) respectively without any interference. Therefore, the developed AMT-Ag NCCP could serve as a highly valuable platform for the fabrication of high-performance electrochemical sensors for the detection of biologically important drug molecules. PMID:27236138

  17. Effect of Supercritical Fluids on the Biological Activity of Absidia coerulea for the Hydroxylation of Reichsterin's Substance Acetate

    Institute of Scientific and Technical Information of China (English)

    Xiu Feng LIU; Hui Ming ZHU; Tuan Wei ZHANG; Bao Quan ZHANG

    2005-01-01

    The viability and biological activity of Absidia coerulea in compressed or supercritical CO2 and C2H4 were studied. The specific activity ofAbsidia coerulea in 7.5MPa CO2 and C2H4 at 306K can reach to 23% and 75% respectively, leading to the feasibility of using supercritical C2H4as an alternative to the organic solvent in the hydroxylation of Reichsterin's substance acetate.

  18. Lattice Boltzmann methods for moving boundary flows

    Energy Technology Data Exchange (ETDEWEB)

    Inamuro, Takaji, E-mail: inamuro@kuaero.kyoto-u.ac.jp [Department of Aeronautics and Astronautics, and Advanced Research Institute of Fluid Science and Engineering, Graduate School of Engineering, Kyoto University, Kyoto 606-8501 (Japan)

    2012-04-01

    The lattice Boltzmann methods (LBMs) for moving boundary flows are presented. The LBM for two-phase fluid flows with the same density and the LBM combined with the immersed boundary method are described. In addition, the LBM on a moving multi-block grid is explained. Three numerical examples (a droplet moving in a constricted tube, the lift generation of a flapping wing and the sedimentation of an elliptical cylinder) are shown in order to demonstrate the applicability of the LBMs to moving boundary problems. (invited review)

  19. Lattice Boltzmann methods for moving boundary flows

    International Nuclear Information System (INIS)

    The lattice Boltzmann methods (LBMs) for moving boundary flows are presented. The LBM for two-phase fluid flows with the same density and the LBM combined with the immersed boundary method are described. In addition, the LBM on a moving multi-block grid is explained. Three numerical examples (a droplet moving in a constricted tube, the lift generation of a flapping wing and the sedimentation of an elliptical cylinder) are shown in order to demonstrate the applicability of the LBMs to moving boundary problems. (invited review)

  20. Precolumn derivatization reagents for high-speed analysis of amines and amino acids in biological fluid using liquid chromatography/electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Shimbo, Kazutaka; Oonuki, Takashi; Yahashi, Akihisa; Hirayama, Kazuo; Miyano, Hiroshi

    2009-05-01

    A rapid analytical method for amines and amino acids was developed, involving derivatization with the novel reagent 3-aminopyridyl-N-hydroxysuccinimidyl carbamate (APDS), followed by reversed-phase high-performance liquid chromatography and electrospray ionization tandem mass spectrometry (HPLC/ESI-MS/MS). More than 100 different analytes with amino groups, including amino acids in biological fluids such as mammalian plasma, could be measured within 10 min. The analytes were easily derivatized with APDS under the mild conditions. Selective reaction monitoring of ESI-MS/MS in positive mode was carried out to include the transitions of all of the protonated molecular ions of analytes derivatized with APDS to the common fragment at m/z 121, which was derived from the amino pyridyl moiety of the reagent. We evaluated the retention time precision, the quantification limits, the linearity, the intra- and inter-day precisions and the accuracy of 22 typical amino acids found in biological fluids, by analyzing a standard amino acid mixture and rat plasma. The intra-day relative standard deviations (RSDs) of the retention times of the 22 amino acids and their internal standards were within 0.9% and the inter-day RSDs were less than 1.1%, except for asparagines, with an RSD of 1.9%. The intra-day and inter-day RSDs of amino acid analyses in rat plasma were within 8.0% and 4.5%, respectively. The method, which facilitates the amino acid analysis of more than 100 samples in a day, represents an alternative to traditional amino acid analysis techniques, such as chromatography using postcolumn derivatization by ninhydrin. PMID:19350529

  1. OCT-based three-dimensional, three vector component imaging of cilia-driven fluid flow for developmental biology (Conference Presentation)

    Science.gov (United States)

    Huang, Brendan K.; Zhou, Kevin C.; Gamm, Ute A.; Bhandari, Vineet; Khokha, Mustafa K.; Choma, Michael A.

    2016-03-01

    One critical barrier to the robust study of cilia-driven fluid flow in developmental biology is a lack of methods for acquiring three-dimensional (3D) images of three vector component (3C) measurements of flow velocities. A 3D3C map of cilia-driven fluid flow quantifies the flow speed along three axes (e.g. three Cartesian vector components v_x, v_y, v_z) at each point in 3D space. 3D3C quantification is important because cilia-driven fluid flow is not amenable to simplifying assumptions (e.g. parabolic flow profile. Such quantification may enable systematically detailed characterization of performance using shear force and power dissipation metrics derived from 3D3C flow velocity fields. We report our OCT-based results in developing methods for the 3D3C quantification of cilia-driven flow fields. First, we used custom scan protocols and reconstruction algorithms to synthesize 3D3C flow velocity fields from 2D2C fields generated using correlation-based methods (directional dynamic light scattering and digital particle image velocimetry). Xenopus results include flow driven by ciliated embryo skin and flow driven by ciliated ependymal cells in developing brain ventricles. Second, we developed a new approach to particle tracking velocimetry that generates 2D2.5C (2.5C: v_x,|v_y|,v_z) velocity fields from single-plane 2D image acquisitions. We demonstrated this particle streak velocimetry method in calibrated flow phantoms and in flow driven by ciliated Xenopus embryo skin. Additionally, we have preliminary results extending particle streak velocimetry to 3D3C in calibrated flow phantoms with ongoing work in Xenopus embryos.

  2. X-ray microanalysis in STEM of short-term physico-chemical reactions at bioactive glass particles / biological fluids interface. Determination of O/Si atomic ratios

    CERN Document Server

    Blanchet, V; Michel, J; Wortham, L; Laurent-Maquin, D; Balossier, G

    2004-01-01

    Short-term physico-chemical reactions at the interface between bioactive glass particles and biological fluids are studied and we focus our attention on the measurements of O/Si atomic ratio. The studied bioactive glass is in the SiO2-Na2O-CaO-P2O5-K2O-Al2O3-MgO system. The elemental analysis is performed at the submicrometer scale by STEM associated with EDXS and EELS. We previously developed an EDXS quantification method based on the ratio method and taking into account local absorption corrections. In this way, we use EELS data to determine, by an iterative process, the local mass thickness which is an essential parameter to correct absorption in EDXS spectra. After different delays of immersion of bioactive glass particles in a simulated biological solution, results show the formation of different surface layers at the bioactive glass periphery. Before one day of immersion, we observe the presence of an already shown (Si,O,Al) rich layer at the periphery. In this paper, we demonstrate that a thin electron...

  3. Fullerene-C60-MWCNT composite film based ultrasensitive electrochemical sensing platform for the trace analysis of pyruvic acid in biological fluids.

    Science.gov (United States)

    Brahman, Pradeep Kumar; Pandey, Nidhi; Topkaya, Seda Nur; Singhai, Rashmi

    2015-03-01

    We propose development of a novel electrochemical sensor based on fullerene-multi-walled carbon nanotubes composite film for the sensitive determination of the pyruvic acid in biological fluids. The developed sensor was characterized by cyclic voltammetry. The nanocomposite film of C60-MWCNTs on GCE exhibits electrocatalytic activity towards pyruvic acid reduction and also decreases the reduction overpotential. The influence of the optimization parameters such as pH and effect of loading of composite mixture of C60 and MWCNTs on the electrochemical performance of the sensor were evaluated. Various kinetic parameters such as electron transfer number (n=2), proton transfer number (m=2) and charge transfer coefficient (α=0.56) were also calculated. Under optimized conditions, the squarewave reduction peak current was linear over the concentration range of 2.0-55 nM with the detection and quantification limit of 0.1 nM and 0.8 nM respectively. The fabricated sensor was successfully applied to the detection of pyruvic acid in biological samples with good recovery ranging from 97.6% to 103.6%. PMID:25618707

  4. STUDY ON APPLICATION OF AERATION BIOLOGICAL FLUID TANK TECHNOLGY IN NH+4-N WASTE WATER TREATMENT%曝气生物流化池(ABFT)技术在含氨氮污水治理的应用研究

    Institute of Scientific and Technical Information of China (English)

    陈怡; 卢建国

    2003-01-01

    This paper introduces an application of "Aeration biological fluid tank" technology (ABFT) for the treatment of waste water containing NH+4-N and high concentrated organic chemicals. Highlights were focused on the effects of dissolved oxygen, pH, temperature and retention time on waste water biological treatment in order to find out a new approach in treatment of waste water containing high concentrated NH+4-N.

  5. Active colloids in complex fluids

    CERN Document Server

    Patteson, Alison E; Arratia, Paulo E

    2016-01-01

    We review recent work on active colloids or swimmers, such as self-propelled microorganisms, phoretic colloidal particles, and artificial micro-robotic systems, moving in fluid-like environments. These environments can be water-like and Newtonian but can frequently contain macromolecules, flexible polymers, soft cells, or hard particles, which impart complex, nonlinear rheological features to the fluid. While significant progress has been made on understanding how active colloids move and interact in Newtonian fluids, little is known on how active colloids behave in complex and non-Newtonian fluids. An emerging literature is starting to show how fluid rheology can dramatically change the gaits and speeds of individual swimmers. Simultaneously, a moving swimmer induces time dependent, three dimensional fluid flows, that can modify the medium (fluid) rheological properties. This two-way, non-linear coupling at microscopic scales has profound implications at meso- and macro-scales: steady state suspension proper...

  6. STRUCTURAL BIOLOGY: A moving story of receptors

    OpenAIRE

    Schwartz, Thue W; Hubbell, Wayne L.

    2008-01-01

    Animals sense light and chemical signals through proteins called G-protein-coupled receptors. The crystal structure of one such receptor in complex with a G-protein fragment shows how these receptors are activated.

  7. The moving mesh code Shadowfax

    CERN Document Server

    Vandenbroucke, Bert

    2016-01-01

    We introduce the moving mesh code Shadowfax, which can be used to evolve a mixture of gas, subject to the laws of hydrodynamics and gravity, and any collisionless fluid only subject to gravity, such as cold dark matter or stars. The code is written in C++ and its source code is made available to the scientific community under the GNU Affero General Public License. We outline the algorithm and the design of our implementation, and demonstrate its validity through the results of a set of basic test problems, which are also part of the public version. We also compare Shadowfax with a number of other publicly available codes using different hydrodynamical integration schemes, illustrating the advantages and disadvantages of the moving mesh technique.

  8. The moving mesh code Shadowfax

    OpenAIRE

    Vandenbroucke, Bert; De Rijcke, Sven

    2016-01-01

    We introduce the moving mesh code Shadowfax, which can be used to evolve a mixture of gas, subject to the laws of hydrodynamics and gravity, and any collisionless fluid only subject to gravity, such as cold dark matter or stars. The code is written in C++ and its source code is made available to the scientific community under the GNU Affero General Public License. We outline the algorithm and the design of our implementation, and demonstrate its validity through the results of a set of basic ...

  9. Is the fluid mosaic (and the accompanying raft hypothesis a suitable model to describe fundamental features of biological membranes? What may be missing?

    Directory of Open Access Journals (Sweden)

    Luis Alberto Bagatolli

    2013-11-01

    Full Text Available The structure, dynamics, and stability of lipid bilayers are controlled by thermodynamic forces, leading to overall tensionless membranes with a distinct lateral organization and a conspicuous lateral pressure profile. Bilayers are also subject to built-in curvature-stress instabilities that may be released locally or globally in terms of morphological changes leading to the formation of non-lamellar and curved structures. A key controller of the bilayer’s propensity to form curved structures is the average molecular shape of the different lipid molecules. Via the curvature stress, molecular shape mediates a coupling to membrane-protein function and provides a set of physical mechanisms for formation of lipid domains and laterally differentiated regions in the plane of the membrane. Unfortunately, these relevant physical features of membranes are often ignored in the most popular models for biological membranes. Results from a number of experimental and theoretical studies emphasize the significance of these fundamental physical properties and call for a refinement of the fluid mosaic model (and the accompanying raft hypothesis.

  10. Gold nanoparticles decorated poly-melamine modified glassy carbon sensor for the voltammetric estimation of domperidone in pharmaceuticals and biological fluids.

    Science.gov (United States)

    Rosy; Goyal, Rajendra N

    2015-08-15

    The electrochemical response of an unmodified glassy carbon (GCE), poly-melamine/GCE and gold nanoparticle (AuNP)/poly-melamine/GCE is compared in the present protocol for the sensitive and selective determination of domperidone (DOM). The AuNPs were synthesized in the laboratory and characterized using UV-visible spectroscopy and Transmission Electron Microscopy (TEM). Melamine was electropolymerized onto the glassy carbon surface using cyclic voltammetry and was investigated using Field Emission Scanning Electron Microscopy (FE-SEM) and Electrochemical Impedance Spectroscopy (EIS). The AuNP/poly-melamine/GCE exhibited the best electrochemical response among the three electrodes for the electro-oxidation of DOM, that was inferred from the EIS, cyclic and square wave voltammetry. The modified sensor showed a sensitive, stable and linear response in the concentration range of 0.05-100µM with a detection limit of 6nM. The selectivity of the proposed sensor was assessed in the presence of high concentration of major interfering molecules as xanthine, hypoxanthine, and uric acid. The analytical application of the sensor for the quantification of DOM in pharmaceutical formulations and biological fluids as urine and serum was also investigated and the results demonstrated a recovery of >95% with R.S.D of <5%. PMID:25966380

  11. A poroelastic immersed boundary method with applications to cell biology

    Science.gov (United States)

    Strychalski, Wanda; Copos, Calina A.; Lewis, Owen L.; Guy, Robert D.

    2015-02-01

    The immersed boundary method is a widely used mixed Eulerian/Lagrangian framework for simulating the motion of elastic structures immersed in viscous fluids. In the traditional immersed boundary method, the fluid and structure move with the same velocity field. In this work, a model based on the immersed boundary method is presented for simulating poroelastic media in which the fluid permeates a porous, elastic structure of small volume fraction that moves with its own velocity field. Two distinct methods for calculating elastic stresses are presented and compared. The methods are validated on a radially symmetric test problem by comparing with a finite difference solution of the classical equations of poroelasticity. Finally, two applications of the modeling framework to cell biology are provided: cellular blebbing and cell crawling. It is shown that in both examples, poroelastic effects are necessary to explain the relevant mechanics.

  12. Moving Target Defense

    CERN Document Server

    Jajodia, Sushil; Swarup, Vipin; Wang, Cliff; Wang, X Sean

    2011-01-01

    Moving Target Defense: Creating Asymmetric Uncertainty for Cyber Threats was developed by a group of leading researchers. It describes the fundamental challenges facing the research community and identifies new promising solution paths. Moving Target Defense which is motivated by the asymmetric costs borne by cyber defenders takes an advantage afforded to attackers and reverses it to advantage defenders. Moving Target Defense is enabled by technical trends in recent years, including virtualization and workload migration on commodity systems, widespread and redundant network connectivity, instr

  13. Everything biological - or what? What distinguishes an environmental-friendly compressed liquid for fluid engineering applications?; Alles Bio - oder was? Was kennzeichnet eine umweltvertraegliche Druckfluessigkeit fuer fluidtechnische Anwendungen?

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2010-11-15

    Recently, messages on a new signet for bio oils intensively circulate in the technical literature. This provided violent discussions and confusion. In order to bring 'light into the darkness', accredited experts of the fluid engineering industry are interviewed by O+P according to their definition for pollution-free hydraulic fluids.

  14. Embodied affectivity: on moving and being moved.

    Science.gov (United States)

    Fuchs, Thomas; Koch, Sabine C

    2014-01-01

    There is a growing body of research indicating that bodily sensation and behavior strongly influences one's emotional reaction toward certain situations or objects. On this background, a framework model of embodied affectivity is suggested: we regard emotions as resulting from the circular interaction between affective qualities or affordances in the environment and the subject's bodily resonance, be it in the form of sensations, postures, expressive movements or movement tendencies. Motion and emotion are thus intrinsically connected: one is moved by movement (perception; impression; affection) and moved to move (action; expression; e-motion). Through its resonance, the body functions as a medium of emotional perception: it colors or charges self-experience and the environment with affective valences while it remains itself in the background of one's own awareness. This model is then applied to emotional social understanding or interaffectivity which is regarded as an intertwinement of two cycles of embodied affectivity, thus continuously modifying each partner's affective affordances and bodily resonance. We conclude with considerations of how embodied affectivity is altered in psychopathology and can be addressed in psychotherapy of the embodied self. PMID:24936191

  15. Embodied affectivity: On moving and being moved

    Directory of Open Access Journals (Sweden)

    Thomas eFuchs

    2014-06-01

    Full Text Available There is a growing body of research indicating that bodily sensation and behaviour strongly influences one’s emotional reaction towards certain situations or objects. On this background, a framework model of embodied affectivity is suggested: we regard emotions as resulting from the circular interaction between affective qualities or affordances in the environment and the subject’s bodily resonance, be it in the form of sensations, postures, expressive movements or movement tendencies. Motion and emotion are thus intrinsically connected: one is moved by movement (perception; impression; affection and moved to move (action; expression; e-motion. Through its resonance, the body functions as a medium of emotional perception: it colours or charges self-experience and the environment with affective valences while it remains itself in the background of one’s own awareness. This model is then applied to emotional social understanding or interaffectivity which is regarded as an intertwinement of two cycles of embodied affectivity, thus continuously modifying each partner’s affective affordances and bodily resonance. We conclude with considerations of how embodied affectivity is altered in psychopathology and can be addressed in psychotherapy of the embodied self.

  16. Fluid Flow at Branching Junctions

    OpenAIRE

    Sochi, Taha

    2013-01-01

    The flow of fluids at branching junctions plays important kinematic and dynamic roles in most biological and industrial flow systems. The present paper highlights some key issues related to the flow of fluids at these junctions with special emphasis on the biological flow networks particularly blood transportation vasculature.

  17. GOMA 6.0 : a full-Newton finite element program for free and moving boundary problems with coupled fluid/solid momentum, energy, mass, and chemical species transport : user%3CU%2B2019%3Es guide.

    Energy Technology Data Exchange (ETDEWEB)

    Schunk, Peter Randall; Rao, Rekha Ranjana; Chen, Ken Shuang; Labreche, Duane A.; Sun, Amy Cha-Tien; Hopkins, Matthew Morgan; Moffat, Harry K.; Roach, Robert Allen; Hopkins, Polly L.; Notz, Patrick K.; Roberts, Scott Alan; Sackinger, Philip A.; Subia, Samuel Ramirez; Wilkes, Edward Dean; Baer, Thomas A.; Noble, David R.; Secor, Robert B. [3M Engineering Systems and Technology, St. Paul, MN

    2013-07-01

    Goma 6.0 is a finite element program which excels in analyses of multiphysical processes, particularly those involving the major branches of mechanics (viz. fluid/solid mechanics, energy transport and chemical species transport). Goma is based on a full-Newton-coupled algorithm which allows for simultaneous solution of the governing principles, making the code ideally suited for problems involving closely coupled bulk mechanics and interfacial phenomena. Example applications include, but are not limited to, coating and polymer processing flows, super-alloy processing, welding/soldering, electrochemical processes, and solid-network or solution film drying. This document serves as a user's guide and reference.

  18. Moving interfaces and quasilinear parabolic evolution equations

    CERN Document Server

    Prüss, Jan

    2016-01-01

    In this monograph, the authors develop a comprehensive approach for the mathematical analysis of a wide array of problems involving moving interfaces. It includes an in-depth study of abstract quasilinear parabolic evolution equations, elliptic and parabolic boundary value problems, transmission problems, one- and two-phase Stokes problems, and the equations of incompressible viscous one- and two-phase fluid flows. The theory of maximal regularity, an essential element, is also fully developed. The authors present a modern approach based on powerful tools in classical analysis, functional analysis, and vector-valued harmonic analysis. The theory is applied to problems in two-phase fluid dynamics and phase transitions, one-phase generalized Newtonian fluids, nematic liquid crystal flows, Maxwell-Stefan diffusion, and a variety of geometric evolution equations. The book also includes a discussion of the underlying physical and thermodynamic principles governing the equations of fluid flows and phase transitions...

  19. Photomicrography of fast-moving cells

    Czech Academy of Sciences Publication Activity Database

    Žižka, Zdeněk; Hostounský, Z.

    České Budějovice, 2005, s. 55-55. ISSN 1214-021X. [Biological Days XVIII. České Budějovice (CZ), 24.10.2005-26.10.2005] Institutional research plan: CEZ:AV0Z50200510 Keywords : fast-moving cells * photomicrography Subject RIV: EE - Microbiology, Virology

  20. Moving Objects Updating

    Science.gov (United States)

    Chen, Jidong; Meng, Xiaofeng

    In moving objects applications, large numbers of locations can be sampled by sensors or GPS periodically, then sent from moving clients to the server and stored in a database. Therefore, continuously maintaining in a database the current locations of moving objects by using a tracking technique becomes very important. The key issue is minimizing the number of updates, while providing precise locations for query results. In this chapter, we will introduce some underlying location update methods. Then, we describe two location update strategies in detail, which can improve the performance. One is the proactive location update strategy, which predicts the movement of moving objects to lower the update frequency; the other is the group location update strategy, which groups the objects to minimize the total number of objects reporting their locations.

  1. PARALLEL MOVING MECHANICAL SYSTEMS

    Directory of Open Access Journals (Sweden)

    Florian Ion Tiberius Petrescu

    2014-09-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Moving mechanical systems parallel structures are solid, fast, and accurate. Between parallel systems it is to be noticed Stewart platforms, as the oldest systems, fast, solid and precise. The work outlines a few main elements of Stewart platforms. Begin with the geometry platform, kinematic elements of it, and presented then and a few items of dynamics. Dynamic primary element on it means the determination mechanism kinetic energy of the entire Stewart platforms. It is then in a record tail cinematic mobile by a method dot matrix of rotation. If a structural mottoelement consists of two moving elements which translates relative, drive train and especially dynamic it is more convenient to represent the mottoelement as a single moving components. We have thus seven moving parts (the six motoelements or feet to which is added mobile platform 7 and one fixed.

  2. The Moving image

    DEFF Research Database (Denmark)

    Hansen, Lennard Højbjerg

    2014-01-01

    Every day we are presented with bodily expressions in audiovisual media – by anchors, journalists and characters in films for instance. This article explores how body language in the moving image has been and can be approached in a scholarly manner.......Every day we are presented with bodily expressions in audiovisual media – by anchors, journalists and characters in films for instance. This article explores how body language in the moving image has been and can be approached in a scholarly manner....

  3. Biological detector and method

    Energy Technology Data Exchange (ETDEWEB)

    Sillerud, Laurel; Alam, Todd M; McDowell, Andrew F

    2014-04-15

    A biological detector includes a conduit for receiving a fluid containing one or more magnetic nanoparticle-labeled, biological objects to be detected and one or more permanent magnets or electromagnet for establishing a low magnetic field in which the conduit is disposed. A microcoil is disposed proximate the conduit for energization at a frequency that permits detection by NMR spectroscopy of whether the one or more magnetically-labeled biological objects is/are present in the fluid.

  4. Biological detector and method

    Energy Technology Data Exchange (ETDEWEB)

    Sillerud, Laurel; Alam, Todd M.; McDowell, Andrew F.

    2015-11-24

    A biological detector includes a conduit for receiving a fluid containing one or more magnetic nanoparticle-labeled, biological objects to be detected and one or more permanent magnets or electromagnet for establishing a low magnetic field in which the conduit is disposed. A microcoil is disposed proximate the conduit for energization at a frequency that permits detection by NMR spectroscopy of whether the one or more magnetically-labeled biological objects is/are present in the fluid.

  5. Biological detector and method

    Science.gov (United States)

    Sillerud, Laurel; Alam, Todd M; McDowell, Andrew F

    2013-02-26

    A biological detector includes a conduit for receiving a fluid containing one or more magnetic nanoparticle-labeled, biological objects to be detected and one or more permanent magnets or electromagnet for establishing a low magnetic field in which the conduit is disposed. A microcoil is disposed proximate the conduit for energization at a frequency that permits detection by NMR spectroscopy of whether the one or more magnetically-labeled biological objects is/are present in the fluid.

  6. Métodos de extração e/ou concentração de compostos encontrados em fluidos biológicos para posterior determinação cromatográfica Methods of extraction and/or concentration of compounds found in biological fluids for subsequent chromatographic determination

    OpenAIRE

    Sonia C. N. Queiroz; Carol H. Collins; Isabel C. S. F. Jardim

    2001-01-01

    When organic compounds present in biological fluids are analysed by chromatographic methods, it is generally necessary to carry out a prior sample preparation due the high complexity of this type of sample, especially when the compounds to be determinated are found in very low concentrations. This article describes some of the principal methods for sample preparation in analyses of substances present in biological fluids. The methods include liquid-liquid extraction, solid phase extraction, s...

  7. Theoretical and Computational Studies of Condensed-Phase Phenomena: The Origin of Biological Homochirality, and the Liquid-Liquid Phase Transition in Network-Forming Fluids

    Science.gov (United States)

    Ricci, Francesco

    This dissertation describes theoretical and computational studies of the origin of biological homochirality, and the existence of a liquid-liquid phase transition in pure-component network-forming fluids. A common theme throughout these studies is the use of sophisticated computer simulation and statistical mechanics techniques to study complex condensed-phase phenomena. In the first part of this dissertation, we use an elementary lattice model with molecular degrees of freedom, and satisfying microscopic reversibility, to investigate the effect of reaction reversibility on the evolution of stochastic symmetry breaking via autocatalysis and mutual inhibition in a closed system. We identify conditions under which the system's evolution towards racemic equilibrium becomes extremely slow, allowing for long-time persistence of a symmetry-broken state. We also identify a "monomer purification" mechanism, due to which a nearly homochiral state can persist for long times, even in the presence of significant reverse reaction rates. Order of magnitude estimates show that with reasonable physical parameters a symmetry broken state could persist over geologically-relevant time scales. In the second part of this dissertation, we study a chiral-symmetry breaking mechanism known as Viedma ripening. We develop a Monte Carlo model to gain further insights into the mechanisms capable of reproducing key experimental signatures associated with this phenomenon. We also provide a comprehensive investigation of how the model parameters impact the system's overall behavior. It is shown that size-dependent crystal solubility alone is insufficient to reproduce most experimental signatures, and that some form of a solid-phase chiral feedback mechanism (e.g., agglomeration) must be invoked in our model. In the third part of this dissertation, we perform rigorous free energy calculations to investigate the possibility of a liquid-liquid phase transition (LLPT) in the Stillinger-Weber (SW

  8. 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 with...

  9. Detecting a Moving Object

    Directory of Open Access Journals (Sweden)

    Archana Sidhanti

    2013-02-01

    Full Text Available Object tracking in video aims at detecting the appearances of an object and also the position of a moving object in a video sequence. Complex and dynamic scenes in video and television broadcasting have been a challenge for computerization of both in terms of storage and interaction. Scenes can be complex wherein there are many cluttered objects with different sizes, shapes, colors and can be dynamic with multiple interacting moving objects in a constantly changing background. Examples of such videos abound in applications like sports, air traffic, car traffic and cloud transformations etc.

  10. Effect of Gas/Water Ratio on the Performance of Combined Cylindrical Anoxic/Aerobic Moving Bed Biofilm Reactors for Biological Nutrients Removal from Domestic Wastewater by Fully Nitrification-Denitrification Processes

    OpenAIRE

    Husham T. Ibrahim; HEQiang; Wisaam S. Al-Rekabi

    2014-01-01

    In this research the continuously up-flow pilot scale Moving Bed Biofilm Reactor (MBBR) which was consists of combined cylindrical anoxic/aerobic MBBR in nested form with anoxic/aerobic volume ratio equal to 0.16 under fully nitrification-denitrification process were used to treated 4 m34+-N, TN and TP, respectively, while the average Dissolved Oxygen concentration (DO) in aerobic and anoxic MBBRs were 4.49 and 0.16 mg/L, respectively.

  11. Development of ovarian hyperstimulation syndrome: interrogation of key proteins and biological processes in human follicular fluid of women undergoing in vitro fertilization

    Czech Academy of Sciences Publication Activity Database

    Jarkovská, Karla; Skalníková, Helena; Halada, Petr; Hrabáková, Rita; Moos, J.; Rezábek, K.; Gadher, S. J.; Kovářová, Hana

    2011-01-01

    Roč. 17, č. 11 (2011), s. 679-692. ISSN 1360-9947 Institutional research plan: CEZ:AV0Z50450515; CEZ:AV0Z50200510 Keywords : biomarkers * computer modelling * human follicular fluid Subject RIV: FK - Gynaecology, Childbirth Impact factor: 3.852, year: 2011

  12. Plasma Waves and Jets from Moving Conductors

    CERN Document Server

    Gralla, Samuel E

    2016-01-01

    We consider force-free plasma waves launched by the motion of conducting material through a magnetic field. We develop a spacetime-covariant formalism for perturbations of a uniform magnetic field and show how the transverse motion of a conducting fluid acts as a source. We show that fast-mode waves are sourced by the compressibility of the fluid, with incompressible fluids launching a pure-Alfven outflow. Remarkably, this outflow can be written down in closed form, at the nonlinear level, for an arbitrary incompressible flow. The instantaneous flow velocity is imprinted on the magnetic field and transmitted away at the speed of light, carrying detailed information about the conducting source at the time of emission. These results can be applied to transients in pulsar outflows and to jets from neutron stars orbiting in the magnetosphere of another compact object. We discuss jets from moving conductors in some detail.

  13. Plasma waves and jets from moving conductors

    Science.gov (United States)

    Gralla, Samuel E.; Zimmerman, Peter

    2016-06-01

    We consider force-free plasma waves launched by the motion of conducting material through a magnetic field. We develop a spacetime-covariant formalism for perturbations of a uniform magnetic field and show how the transverse motion of a conducting fluid acts as a source. We show that fast-mode waves are sourced by the compressibility of the fluid, with incompressible fluids launching a pure-Alfvén outflow. Remarkably, this outflow can be written down in closed form for an arbitrary time-dependent, nonaxisymmetric incompressible flow. The instantaneous flow velocity is imprinted on the magnetic field and transmitted away at the speed of light, carrying detailed information about the conducting source at the time of emission. These results can be applied to transients in pulsar outflows and to jets from neutron stars orbiting in the magnetosphere of another compact object. We discuss jets from moving conductors in some detail.

  14. Métodos de extração e/ou concentração de compostos encontrados em fluidos biológicos para posterior determinação cromatográfica Methods of extraction and/or concentration of compounds found in biological fluids for subsequent chromatographic determination

    Directory of Open Access Journals (Sweden)

    Sonia C. N. Queiroz

    2001-02-01

    Full Text Available When organic compounds present in biological fluids are analysed by chromatographic methods, it is generally necessary to carry out a prior sample preparation due the high complexity of this type of sample, especially when the compounds to be determinated are found in very low concentrations. This article describes some of the principal methods for sample preparation in analyses of substances present in biological fluids. The methods include liquid-liquid extraction, solid phase extraction, supercritical fluid extraction and extraction using solid and liquid membranes. The advantages and disadvantages of these methods are discussed.

  15. Let's Keep Moving!

    Science.gov (United States)

    Obama, Michelle

    2012-01-01

    First Lady Michelle Obama lauds educators for following the lead of her Let's Move! program and taking action to curtail childhood obesity. The battle to make children healthier is being waged on a number of fronts by food companies, restaurants and schools. Progress has been made, she says, but more is needed.

  16. Moving Spatial Keyword Queries

    DEFF Research Database (Denmark)

    Wu, Dingming; Yiu, Man Lung; Jensen, Christian S.

    2013-01-01

    Web users and content are increasingly being geo-positioned. This development gives prominence to spatial keyword queries, which involve both the locations and textual descriptions of content. We study the efficient processing of continuously moving top-k spatial keyword (MkSK) queries over spatial...

  17. Indexing Moving Points

    DEFF Research Database (Denmark)

    Agarwal, Pankaj K.; Arge, Lars Allan; Erickson, Jeff

    2003-01-01

    We propose three indexing schemes for storing a set S of N points in the plane, each moving along a linear trajectory, so that any query of the following form can be answered quickly: Given a rectangle R and a real value t, report all K points of S that lie inside R at time t. We first present an...

  18. Moving into an interaction

    DEFF Research Database (Denmark)

    Mortensen, Kristian; Hazel, Spencer

    2014-01-01

    Opening an interaction is a crucial step in establishing and maintaining social relationships. In this paper we describe how participants in an institutional setting, a help desk counter for exchange students at an international university, literally move into interaction. This is accomplished th...

  19. What moves us?

    DEFF Research Database (Denmark)

    2015-01-01

    Katalog til udstillingen på Museum Jorn - What moves us? Le Corbusier & Asger Jorn - 12. sept. - 13. dec. 2015. Kataloget undersøger Le Corbusiers skifte fra en rationelt funderet tilgang til arkitekturen til en poetisk, materialistisk tilgang i efterkrigstiden. Den viser hans indflydelse på den ...

  20. Moving and union dissolution

    NARCIS (Netherlands)

    P.J. Boyle; H. Kulu; T. Cooke; V. Gayle; C.H. Mulder

    2008-01-01

    This paper examines the effect of migration and residential mobility on union dissolution among married and cohabiting couples. Moving is a stressful life event, and a large, multidisciplinary literature has shown that family migration often benefits one partner (usually the man) more than the other

  1. Moving up in industry.

    Science.gov (United States)

    Covell, Charlotte

    2016-01-23

    Charlotte Covell is commercial business manager at Virbac UK, a role that gives her responsibility for the company's sales to corporate practices, some buying groups and internet pharmacies. She began her career as a veterinary nurse, but moved into industry and now has a role in senior business management. PMID:26795866

  2. 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

  3. On the Flow of a Dusty Fluid

    Directory of Open Access Journals (Sweden)

    J.P. Singh

    1977-10-01

    Full Text Available The present paper deals with the flow of a fluid with uniform distribution of dust particles in two parts. In part A, the motion induced in the dusty fluid is considered in the case when the plane moves parallel to itself impulsively from rest with uniform velocity; for this case, the velocity profiles of fluid as well as dust particles are obtained. In part B, the flow is produced by the motion of cylinders. Two cases are taken : (i cylinders moving exponentially with time and, (ii cylinders moving in simple harmonic motion.

  4. The Moving Flame Experiment

    OpenAIRE

    Stern, Melvin E.

    2011-01-01

    When a flame is rotated around the outside bottom rim of a cylindrical pan of water initially at rest, D. Fultz has observed that the fluid acquires a net vertical component of angular momentum opposite to the rotation of the heat source. We have repeated this experiment in a cylindrical annulus in order to restrict the radial motions and have found that the same phenomenon occurs. Using a simple model based on the latter experiment we investigate the mechanism by which a fluid can acquire an...

  5. Radiation Effects on the Flow and Heat Transfer over a Moving Plate in a Parallel Stream

    Institute of Scientific and Technical Information of China (English)

    Anuar Ishak

    2009-01-01

    Effects of thermal radiation on the steady laminar boundary layer flow over a moving plate in a moving fluid is investigated. Under certain conditions,the present problem reduces to the classical Blasius and Sakiadis problems.It is found that dual solutions exist when the plate and the fluid move in the opposite directions.Moreover,the existence of thermal radiation is to reduce the heat transfer rate at the surface.

  6. Spatial discretization issues for the energy conservation in compressible flow problems on moving grids

    OpenAIRE

    Vázquez, M.; Koobus, B.; Dervieux, Alain; Farhat, Ch.

    2003-01-01

    The prediction of interaction phenomena between a compressible flow in a moving domain and other models like structural ones requires that some conservation properties need to be satisfied by the numerical schemes. In this paper we investigate the important problem of the work-energy conservation within the fluid for the discrete formulation on moving grids. In the case of a compressible flow, the work performed on the fluid by the moving interface has to be properly translated in a variation...

  7. Effect of Gas/Water Ratio on the Performance of Combined Cylindrical Anoxic/Aerobic Moving Bed Biofilm Reactors for Biological Nutrients Removal from Domestic Wastewater by Fully Nitrification-Denitrification Processes

    Directory of Open Access Journals (Sweden)

    Husham T. Ibrahim

    2014-04-01

    Full Text Available In this research the continuously up-flow pilot scale Moving Bed Biofilm Reactor (MBBR which was consists of combined cylindrical anoxic/aerobic MBBR in nested form with anoxic/aerobic volume ratio equal to 0.16 under fully nitrification-denitrification process were used to treated 4 m34+-N, TN and TP, respectively, while the average Dissolved Oxygen concentration (DO in aerobic and anoxic MBBRs were 4.49 and 0.16 mg/L, respectively.

  8. Proteome Mining of Human Follicular Fluid Reveals a Crucial Role of Complement Cascade and Key Biological Pathways in Women Undergoing in Vitro Fertilization

    Czech Academy of Sciences Publication Activity Database

    Jarkovská, Karla; Martinková, Jiřina; Lišková, Lucie; Halada, Petr; Moos, J.; Rezábek, K.; Gadher, S. J.; Kovářová, Hana

    2010-01-01

    Roč. 9, č. 3 (2010), s. 1289-1301. ISSN 1535-3893 R&D Projects: GA MZd(CZ) NS9781; GA AV ČR 1QS500450568 Institutional research plan: CEZ:AV0Z50450515; CEZ:AV0Z50200510 Keywords : Human follicular fluid * plasma * assisted reproduction Subject RIV: FK - Gynaecology, Childbirth Impact factor: 5.460, year: 2010

  9. Moving in Circles

    DEFF Research Database (Denmark)

    Simonsen, Gunvor

    2008-01-01

    The article examines the development of African diaspora history during the last fifty years. It outlines the move from a focus on African survivals to a focus on deep rooted cultural principles and back again to a revived interest in concrete cultural transfers from Africa to the Americas. This...... circular movement can be explained by a combination of elements characterizing African Atlantic and black Atlantic history. Among them is a lack of attention to questions of periodisation and change. Likewise, it has proven difficult to conceptualize Africa and America at one and the same time as...... characterized by cultural diversity and variation. Moreover, the field has been haunted by a tendency of moving to easily from descriptive evidence to conclusions about African identity in the Americas. A promising way to overcome these problems, it is suggested, is to develop research that focuses on single...

  10. Women on the move

    Directory of Open Access Journals (Sweden)

    Ana M. González Ramos

    2013-07-01

    Full Text Available The special issue Women on the Move that the reader holds in their hands is the result of the hard work of very creative specialists in gender and mobility. Research on mobility and gender has progressively advanced from traditional, non-gender-specific literature on migration or mobility of highly skilled people. And, as these authors prove, the topic is already quantitatively and qualitatively relevant.

  11. WOMEN ON THE MOVE

    Directory of Open Access Journals (Sweden)

    Ana M. González Ramos

    2013-10-01

    Full Text Available The special issue Women on the Move that the reader holds in their hands is the result of the hard work of very creative specialists in gender and mobility. Research on mobility and gender has progressively advanced from traditional, non-gender-specific literature on migration or mobility of highly skilled people. And, as these authors prove, the topic is already quantitatively and qualitatively relevant.

  12. Lecture - "Move! Eat better"

    CERN Multimedia

    2012-01-01

    As part of the "Move! Eat better" campaign, Novae’s nutrition adviser, Irène Rolfo, will give a talk on the subject of everyday good nutrition. This will be held in the main building auditorium at 12:30 on Thursday, 20 September 2012. Don’t miss this informative event. For more information, go to http://cern.ch/bpmm            

  13. TCR moves to MCR

    CERN Multimedia

    Peter Sollander, AB/OP/TI

    2005-01-01

    The monitoring of CERN's technical infrastructure has moved from the Technical Control Room in building 212 to the Meyrin Control Room (MCR) in building 354 (see map) and from the TS/CSE group to AB/OP. The operation's team as well as the services provided remain the same as before and you can still reach the operator on shift by calling 72201. Peter Sollander, AB/OP/TI

  14. A moving experience !

    CERN Multimedia

    2005-01-01

    The Transport Service pulled out all the stops and, more specifically, its fleet of moving and lifting equipment for the Discovery Monday on 6 June - a truly moving experience for all the visitors who took part ! Visitors could play at being machine operator, twiddling the controls of a lift truck fitted with a jib to lift a dummy magnet into a wooden mock-up of a beam-line.They had to show even greater dexterity for this game of lucky dip...CERN-style.Those with a head for heights took to the skies 20 m above ground in a telescopic boom lift.Children were allowed to climb up into the operator's cabin - this is one of the cranes used to move the LHC magnets around. Warm thanks to all members of the Transport Service for their participation, especially B. Goicoechea, T. Ilkei, R. Bihery, S. Prodon, S. Pelletier, Y. Bernard, A.  Sallot, B. Pigeard, S. Guinchard, B. Bulot, J. Berrez, Y. Grandjean, A. Bouakkaz, M. Bois, F. Stach, T. Mazzarino and S. Fumey.

  15. To Move or Not to Move? The Relationship between Career Management and Preferred Career Moves

    OpenAIRE

    Vos, A; K. DEWETTINCK; D. BUYENS

    2006-01-01

    This paper explores professional employees’ career move preferences and the impact of both individual and organizational career management. Departing from theoretical work on the “new career”, different types of career moves employees can make on the internal labor market are discussed (i.e. vertical moves, lateral moves, job enrichment and temporary moves). Next, these are related to the literature on both organizational and individual career management. Hypotheses are formulated about profe...

  16. 壳聚糖/丝胶蛋白生物流体材料的制备及性能测试%Preparation and Property Characterization of Chitosan/Sericin Biological Fluid Material

    Institute of Scientific and Technical Information of China (English)

    严晨峰; 刘琳; 姚菊明

    2013-01-01

    To overcome the limitation of commercial wound dressings with poor fluid absorption capability,a novel chitosan/sericin biological fluid material was successfully prepared by using chitosan extracted from shells of sea crabs and sericin discarded as waste material in silk industry as the major materials.The unique biological material was tawny,semitransparent and semi-fluid.It could form soft and transparent film,functioning as a natural barrier against infection.Its fluid absorption capability and permeability could be adjusted by changing the ratio of chitosan to sericin.Its moist absorption capability and water vapor permeability was in the range of 2.33 ~23.73 g/g and 2 738 ~3 752 g/(m2 ·d) respectively,being able to satisfy the needs in healing various wounds.The mechanical property of resultant film slightly reduced after addition of sericin,but it still kept excellent flexibility to satisfy clinical demand of wound dressing.In vitro antibacterial experiment indicated that,although the addition of sericin reduced antibacterial activity of the fluid material,its antibacterial rate was as high as 83% against Staphylococcus aureus when the mass ratio of chitosan to sericin was 1 ∶ 0.6,being able to prevent wound infection effectively.These results indicate that the novel chitosan/sericin biological fluid materials have good perspective in clinical application.%针对现有医用敷料吸收渗液能力不强等缺点,以海洋蟹虾外壳中提取的壳聚糖和蚕丝加工过程废弃的丝胶蛋白为主要原料,研制出一种新型生物流体材料.该材料为黄褐色半透明、半流动物质,能形成柔韧透明的薄膜从而起到防感染的天然屏障作用.通过改变壳聚糖与丝胶蛋白的配比,可以有效调控壳聚糖/丝胶蛋白生物流体材料膜的吸液能力和通透性等,其吸水量、水蒸汽透过率分别分布在2.33~ 23.73 g/g和2 738 ~3 752 g/(m2·d)之间,可以满足不同程度创面修复需要.虽

  17. Ecotoxicological testing of performance fluids

    International Nuclear Information System (INIS)

    The report deals with a project comprising the testing of drilling fluids concerning ecotoxicology, biological degradation, and toxicity. Two types of drilling fluids were tested for toxic effects on marine algae and biological degradability. A fluid based on mineral oil was readily degradable (98% DOC removal in 28 days) while an ether based oil degraded more slowly (56% DOC removal in 28 days). The toxicity of both fluids was tested after emulsification of the oils in water and separating the oil and water phase after equilibration. The EC50 values obtained with this approach were 8.15 g/l for the oil based fluid and 116 g/l for the ether fluid. 9 figs., 8 tabs

  18. Apparatus for Pumping a Fluid

    Science.gov (United States)

    Boeyen, Robert Van; Reeh, Jonathan

    2013-01-01

    A fluid pump has been developed for mechanically pumped fluid loops for spacecraft thermal control. Lynntech's technology utilizes a proprietary electrochemically driven pumping mechanism. Conventional rotodynamic and displacement pumps typically do not meet the stringent power and operational reliability requirements of space applications. Lynntech's developmental pump is a highly efficient solid-state pump with essentially no rotating or moving components (apart from metal bellows).

  19. No Moving Parts

    Science.gov (United States)

    1998-01-01

    Under a NASA SBIR (Small Business Innovative Research), Research International developed the solid state micromachined pump used for cooling electronics in space, circulation of heat transfer fluids on spacecraft, and monitoring fire and gas hazards aboard naval warships. Incorporating Lewis Research Center's pumping technology, commercial applications for this product include both detection of toxins and pollutants in coal mines, and early warning smoke detectors for industrial applications.

  20. Determination of Gemfibrozil (Lipitor and Lopid) in Water, Biological Fluids and Drug Matrix by Dispersive Liquid-Liquid micro Extraction (DLLME) and Liquid Chromatography

    OpenAIRE

    Ghorbani A.; Dayani M.

    2014-01-01

    In this study Dispersive liquid-liquid micro extraction (DLLME) coupled with High performance liquid chromatography was applied for the determination of Gemfibrozil in water, drug`s matrix and biological liquids (human plasma and urine). In this method, the appropriate mixture of extraction solvent (200 μl chlorophorm) and disperser solvent (1 ml methanol) are injected rapidly into the aqueous sample (10.0 ml) by syringe, cloudy solution is formed that consisted of fine particles of extractio...

  1. Moving the Maasai

    OpenAIRE

    Hughes, Lotte.; Professor W. Beinart, Dr D.A. Turton

    2003-01-01

    This dissertation examines the two major forced moves of the Maasai in British East Africa in the 1900s, through which the 'northern' sections lost the greater part of their land, and non-violent resistance to these events which culminated in a landmark court case in 1913. The Maasai lost this action, the so-called Maasai Case, on a technicality. The dissertation amis to compare the parallel and contested narratives of the British and the Maasai about these events and related ...

  2. Bacterial Chemotaxis with a Moving Target

    Science.gov (United States)

    Dominick, Corey

    2015-03-01

    Most chemotaxis studies so far have been conducted in a quiescent fluid with a well-defined chemical gradient. Such experiments may be appropriate for studying enteric bacteria, such as Escherichia coli, but the environment it provides is very different from that typically encountered by marine bacteria. Herein we describe an experiment in which marine bacterium Vibrio alginolyticusis subject to stimulation by a small moving target. A micropipette of the tip size <1 ?m is used to slowly release a chemoattractant, serine, at different concentrations. The pipette is made to move with different patterns and speeds, ranging from 0 to 100 ?m/s; the latter is about twice the bacterial swimming speed. We found that if the pipette is moved slowly, with 1/4 of bacterial swimming speed, cells accumulate near the tip region but when it is moved with speed greater than 1/2 the bacterial swimming speed, cells trail behind the pipette over a large distance. The behaviors observed in V. alginolyticusare significantly different from E. coli, suggesting that the former is a better chemotaxer in a changing environment.

  3. Electrodynamics of moving magnetoelectric media: variational approach

    CERN Document Server

    Obukhov, Yuri N

    2007-01-01

    Recently, Feigel has predicted a new effect in magnetoelectric media. The theoretical evaluation of this effect requires a careful analysis of a dynamics of the moving magnetoelectric medium and, in particular, the derivation of the energy-momentum of the electromagnetic field in such a medium. Then, one can proceed with the study of the wave propagation in this medium and derive the mechanical quantities such as the energy, the momentum, and their fluxes and the corresponding forces. In this paper, we develop a consistent general-relativistic variational approach to the moving dielectric and magnetic medium with and without magnetoelectric properties. The old experiments in which the light pressure was measured in fluids are reanalysed in our new framework.

  4. Electrodynamics of moving magnetoelectric media: Variational approach

    Energy Technology Data Exchange (ETDEWEB)

    Obukhov, Yuri N. [Institute for Theoretical Physics, University of Cologne, 50923 Cologne (Germany); Department of Theoretical Physics, Moscow State University, 117234 Moscow (Russian Federation)], E-mail: yo@htp.uni-koeln.de; Hehl, Friedrich W. [Institute for Theoretical Physics, University of Cologne, 50923 Cologne (Germany); Department of Physics and Astronomy, University of Missouri-Columbia, Columbia, MO 65211 (United States)], E-mail: hehl@thp.uni-koeln.de

    2007-11-05

    Recently, Feigel has predicted a new effect in magnetoelectric media. The theoretical evaluation of this effect requires a careful analysis of a dynamics of the moving magnetoelectric medium and, in particular, the derivation of the energy-momentum of the electromagnetic field in such a medium. Then, one can proceed with the study of the wave propagation in this medium and derive the mechanical quantities such as the energy, the momentum, and their fluxes and the corresponding forces. In this Letter, we develop a consistent general-relativistic variational approach to the moving dielectric and magnetic medium with and without magnetoelectric properties. The old experiments in which the light pressure was measured in fluids are reanalysed in our new framework.

  5. Drop Impact on to Moving Liquid Pools

    Science.gov (United States)

    Muñoz-Sánchez, Beatriz Natividad; Castrejón-Pita, José Rafael; Castrejón-Pita, Alfonso Arturo; Hutchings, Ian M.

    2014-11-01

    The deposition of droplets on to moving liquid substrates is an omnipresent situation both in nature and industry. A diverse spectrum of phenomena emerges from this simple process. In this work we present a parametric experimental study that discerns the dynamics of the impact in terms of the physical properties of the fluid and the relative velocity between the impacting drop and the moving liquid pool. The behaviour ranges from smooth coalescence (characterized by little mixing) to violent splashing (generation of multiple satellite droplets and interfacial vorticity). In addition, transitional regimes such as bouncing and surfing are also found. We classify the system dynamics and show a parametric diagram for the conditions of each regime. This work was supported by the EPSRC (Grant EP/H018913/1), the Royal Society, Becas Santander Universidades and the International Relationships Office of the University of Extremadura.

  6. Ready, set, move!

    CERN Multimedia

    Anaïs Schaeffer

    2012-01-01

    This year, the CERN Medical Service is launching a new public health campaign. Advertised by the catchphrase “Move! & Eat Better”, the particular aim of the campaign is to encourage people at CERN to take more regular exercise, of whatever kind.   The CERN annual relay race is scheduled on 24 May this year. The CERN Medical Service will officially launch its “Move! & Eat Better” campaign at this popular sporting event. “We shall be on hand on the day of the race to strongly advocate regular physical activity,” explains Rachid Belkheir, one of the Medical Service doctors. "We really want to pitch our campaign and answer any questions people may have. Above all we want to set an example. So we are going to walk the same circuit as the runners to underline to people that they can easily incorporate movement into their daily routine.” An underlying concern has prompted this campaign: during their first few year...

  7. Forces on bodies moving unsteadily in rapidly compressed flows

    OpenAIRE

    Eames, I.; Hunt, J.C.R.

    2004-01-01

    The inviscid compressible flow generated by a rigid body of volume V moving unsteadily with a velocity U in a rapidly compressed homentropic flow is considered. The fluid is compressed isentropically at a rate del.v(0) uniformly over a scale much larger than the size of the body and the body moves slowly enough that the Mach number M is low. The flow is initially irrotational and remains so during compression. The perturbation to the flow generated by the body moving unsteadily is non-diverge...

  8. Are we ready to move beyond the reductionist approach of classical synergy control?. Comment on "Hand synergies: Integration of robotics and neuroscience for understanding the control of biological and artificial hands" by Marco Santello et al.

    Science.gov (United States)

    Lacquaniti, Francesco; Ivanenko, Yuri P.; Zago, Myrka

    2016-07-01

    Starting from the classical concepts introduced by Sherrington [1] and considerably elaborated by Bernstein [2], much has been learned about motor synergies in the last several years. The contributions of the group funded by the European project "The Hand Embodied" are remarkable in the field of biological and robotic control of the hand based on synergies, and they are reflected in this enjoyable review [3]. There, Santello et al. adopt Bernstein's definition of motor synergies as multiple elements working together towards a common goal, with the result that multiple degrees of freedom are controlled within a lower-dimensional space than the available number of dimensions.

  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. Understanding the bioavailability and sequestration of different metal cations in the presence of a biodegradable chelant S,S-EDDS in biological fluids and natural waters.

    Science.gov (United States)

    Bretti, Clemente; Cigala, Rosalia Maria; De Stefano, Concetta; Lando, Gabriele; Sammartano, Silvio

    2016-05-01

    Ethylenediamine-N,N'-disuccinic acid is a biodegradable alternative to EDTA, therefore its use for the sequestration of Ca(2+), Sn(2+), Cu(2+), Zn(2+) and Fe(3+) is analyzed. New data on its binding ability towards these cations were obtained with potentiometric, voltammetric and calorimetric measurements at different ionic strengths and at T = 298.15 K. Real multi-component fluids, namely fresh water, urine, sea water, saliva and blood plasma were chosen as case studies to evaluate the sequestering ability of EDDS in comparison with EDTA. Speciation diagrams were drawn in selected conditions, considering all interactions among the "natural" components of the fluid and those studied in this work, EDDS and EDTA (cL = 1 mmol dm(-3)) as sequestering agents and the cited metal cations (cM ∼ 10(-5) mol dm(-3)). The comparison of the sequestering ability of EDDS and EDTA is done using pM and pL0.5. In blood plasma the plasma mobilizing index was adopted. It was found that EDDS is a good alternative to EDTA, which tends to bind Ca(2+) and Mg(2+) more than EDDS. In particular, EDTA cannot be used as a sequestrant for Sn(2+) when cCa > cEDTA. EDDS is more efficient than EDTA at pH PMI of EDDS towards Cu(2+) is higher than that of EDTA. Thermodynamic information, in terms of ΔH and ΔS, for the protonation and metal complex formation reactions are reported. PMID:26921587

  11. Shadowfax: Moving mesh hydrodynamical integration code

    Science.gov (United States)

    Vandenbroucke, Bert

    2016-05-01

    Shadowfax simulates galaxy evolution. Written in object-oriented modular C++, it evolves a mixture of gas, subject to the laws of hydrodynamics and gravity, and any collisionless fluid only subject to gravity, such as cold dark matter or stars. For the hydrodynamical integration, it makes use of a (co-) moving Lagrangian mesh. The code has a 2D and 3D version, contains utility programs to generate initial conditions and visualize simulation snapshots, and its input/output is compatible with a number of other simulation codes, e.g. Gadget2 (ascl:0003.001) and GIZMO (ascl:1410.003).

  12. Moving wheelchairs with your thoughts

    OpenAIRE

    Duca, Edward

    2012-01-01

    Brain to computer interface (BCI) devices can read a person’s thoughts and turn them into commands to move objects. They can give freedom to people suffering from movement impairments. Rosanne Zerafa (supervised by Tracey Camilleri) developed a system that detects a person’s brain patterns while they are thinking of moving a particular part of their body and translates them into commands to move a cursor. http://www.um.edu.mt/think/moving-wheelchairs-with-your-thoughts/

  13. Conjugation of glucose oxidase onto Mn-doped ZnS quantum dots for phosphorescent sensing of glucose in biological fluids.

    Science.gov (United States)

    Wu, Peng; He, Yu; Wang, He-Fang; Yan, Xiu-Ping

    2010-02-15

    Integrating various enzymes with nanomaterials provides various nanohybrids with new possibilities in biosensor applications. Furthermore, the enzymatic activity and stability are also improved due to the large surface area of nanomaterials. Here we report the conjugation of glucose oxidase (GOD) onto phosphorescent Mn-doped ZnS quantum dots (QDs) using 1-ethyl-3-(3-dimethylaminopropy)carbodiimide (EDC)/N-hydroxysuccinimide (NHS) as coupling reagents for glucose biosensing based on the effective quenching of the room temperature phosphorescence (RTP) of Mn-doped ZnS QDs by the H(2)O(2) generated from GOD-catalyzed oxidation of glucose. The obtained bioconjugate not only provided improved enzymatic performance with Michaelis-Menten constant of 0.70 mM but also favored biological applications because the phosphorescent detection mode avoided the interference from autofluorescence and scattering light from the biological matrix. In addition, the GOD-conjugated Mn-doped ZnS QDs showed better thermal stability in the temperature range of 20-80 degrees C. The GOD-Mn-doped ZnS QDs based RTP sensor for glucose gave a detection limit of 3 microM and two linear ranges from 10 microM to 0.1 mM and from 0.1 to 1 mM. The developed biosensor was successfully applied to the determination of glucose in real serum samples without the need for any complicated sample pretreatments. PMID:20092317

  14. Move! Eat better: news

    CERN Document Server

    2013-01-01

    Are you curious to know whether you’re doing enough daily exercise…? Test yourself with a pedometer!   Through the Move! Eat better campaign, launched in May 2012, the CERN medical service is aiming to improve the health of members of the personnel by encouraging them to prioritise physical activity in conjunction with a balanced diet. Various successful activities have already taken place: relay race/Nordic walk, Bike2work, Zumba and fitness workshops, two conferences (“Physical activity for health” and “Good nutrition every day”), events in the restaurants, as well as posters and a website. Although everyone has got the message from our various communications that physical activity is good for your health, there is still a relevant question being asked: “What is the minimum amount of exercise recommended?” 10,000 steps per day is the ideal figure, which has been demonstrated as beneficial by scientific studies ...

  15. Multinationals Move Inland

    Institute of Scientific and Technical Information of China (English)

    CHRIS; DEVONSHIRE-ELLIS

    2008-01-01

    Central China, initially overlooked by many foreign investors as being too far from the ports in Tianjin, Shanghai and Shenzhen, is emerging as an essential destination for multinationals in China.The Future of Central China: A Provincial Roadmap There is a huge manufacturing drive in central China. Businesses are moving inland to set up projects, investments and operations here, primarily due to lower labor and land costs as well as preferential policies for manufacturers. Multinational companies also are starting to view the region as the next step toward an integrated China strategy, and the consumer population in the second-and third-tier cities in central China represents a growing, largely untapped domestic market for foreign products and services.

  16. Moving Detectors in Cavities

    CERN Document Server

    Obadia, N

    2007-01-01

    We consider two-level detectors, coupled to a quantum scalar field, moving inside cavities. We highlight some pathological resonant effects due to abrupt boundaries, and decide to describe the cavity by switching smoothly the interaction by a time-dependent gate-like function. Considering uniformly accelerated trajectories, we show that some specific choices of non-adiabatic switching have led to hazardous interpretations about the enhancement of the Unruh effect in cavities. More specifically, we show that the emission/absorption ratio takes arbitrary high values according to the emitted quanta properties and to the transients undergone at the entrance and the exit of the cavity, {\\it independently of the acceleration}. An explicit example is provided where we show that inertial and uniformly accelerated world-lines can even lead to the same ``pseudo-temperature''.

  17. Moving Single Atoms

    Science.gov (United States)

    Stuart, Dustin

    2016-05-01

    Single neutral atoms are promising candidates for qubits, the fundamental unit of quantum information. We have built a set of optical tweezers for trapping and moving single Rubidium atoms. The tweezers are based on a far off-resonant dipole trapping laser focussed to a 1 μm spot with a single aspheric lens. We use a digital micromirror device (DMD) to generate dynamic holograms of the desired arrangement of traps. The DMD has a frame rate of 20 kHz which, when combined with fast algorithms, allows for rapid reconfiguration of the traps. We demonstrate trapping of up to 20 atoms in arbitrary arrangements, and the transport of a single-atom over a distance of 14 μm with continuous laser cooling, and 5 μm without. In the meantime, we are developing high-finesse fibre-tip cavities, which we plan to use to couple pairs of single atoms to form a quantum network.

  18. ToF-SIMS images and spectra of biomimetic calcium silicate-based cements after storage in solutions simulating the effects of human biological fluids

    Science.gov (United States)

    Torrisi, A.; Torrisi, V.; Tuccitto, N.; Gandolfi, M. G.; Prati, C.; Licciardello, A.

    2010-01-01

    ToF-SIMS images were obtained from a section of a tooth, obturated by means of a new calcium-silicate based cement (wTCF) after storage for 1 month in a saline solutions (DPBS), in order to simulate the body fluid effects on the obturation. Afterwards, ToF-SIMS spectra were obtained from model samples, prepared by using the same cement paste, after storage for 1 month and 8 months in two different saline solutions (DPBS and HBSS). ToF-SIMS spectra were also obtained from fluorine-free cement (wTC) samples after storage in HBSS for 1 month and 8 months and used for comparison. It was found that the composition of both the saline solution and the cement influenced the composition of the surface of disks and that longer is the storage greater are the differences. Segregation phenomena occur both on the cement obturation of the tooth and on the surface of the disks prepared by using the same cement. Indirect evidences of formation of new crystalline phases are supplied.

  19. A Novel HPLC Method for the Concurrent Analysis and Quantitation of Seven Water-Soluble Vitamins in Biological Fluids (Plasma and Urine: A Validation Study and Application

    Directory of Open Access Journals (Sweden)

    Margherita Grotzkyj Giorgi

    2012-01-01

    Full Text Available An HPLC method was developed and validated for the concurrent detection and quantitation of seven water-soluble vitamins (C, B1, B2, B5, B6, B9, B12 in biological matrices (plasma and urine. Separation was achieved at 30°C on a reversed-phase C18-A column using combined isocratic and linear gradient elution with a mobile phase consisting of 0.01% TFA aqueous and 100% methanol. Total run time was 35 minutes. Detection was performed with diode array set at 280 nm. Each vitamin was quantitatively determined at its maximum wavelength. Spectral comparison was used for peak identification in real samples (24 plasma and urine samples from abstinent alcohol-dependent males. Interday and intraday precision were <4% and <7%, respectively, for all vitamins. Recovery percentages ranged from 93% to 100%.

  20. Fluids engineering

    International Nuclear Information System (INIS)

    Fluids engineering has played an important role in many applications, from ancient flood control to the design of high-speed compact turbomachinery. New applications of fluids engineering, such as in high-technology materials processing, biotechnology, and advanced combustion systems, have kept up unwaining interest in the subject. More accurate and sophisticated computational and measurement techniques are also constantly being developed and refined. On a more fundamental level, nonlinear dynamics and chaotic behavior of fluid flow are no longer an intellectual curiosity and fluid engineers are increasingly interested in finding practical applications for these emerging sciences. Applications of fluid technology to new areas, as well as the need to improve the design and to enhance the flexibility and reliability of flow-related machines and devices will continue to spur interest in fluids engineering. The objectives of the present seminar were: to exchange current information on arts, science, and technology of fluids engineering; to promote scientific cooperation between the fluids engineering communities of both nations, and to provide an opportunity for the participants and their colleagues to explore possible joint research programs in topics of high priority and mutual interest to both countries. The Seminar provided an excellent forum for reviewing the current state and future needs of fluids engineering for the two nations. With the Seminar ear-marking the first formal scientific exchange between Korea and the United States in the area of fluids engineering, the scope was deliberately left broad and general

  1. CHINA ON THE MOVE

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A holiday train special for migrant workers in Hangzhou, east China’s Zhejiang Province, takes to the track before the kick-off of the 2007 Spring Festival travel peak, carrying more than 1,000 passengers back to their homes in Guizhou Province. China’s railways and highways are reportedly ready to transport a record 156 million and 2 billion passengers between February 3 and March 14, up 4.3 and 5 percent year on year, respectively, said government sources. Chinese traditionally travel home for family reunions on the Spring Festival, which falls on February 18 this year. In addition to a freeze on transport fares to benefit the public, transportation authorities have also taken measures to keep vehicle flows fluid during the rush period. A total of 318 pairs of temporary passenger trains will be added to ease the traffic pressure.

  2. The Bernoulli Equation in a Moving Reference Frame

    Science.gov (United States)

    Mungan, Carl E.

    2011-01-01

    Unlike other standard equations in introductory classical mechanics, the Bernoulli equation is not Galilean invariant. The explanation is that, in a reference frame moving with respect to constrictions or obstacles, those surfaces do work on the fluid, constituting an extra term that needs to be included in the work-energy calculation. A…

  3. Ecotoxicological testing of performance fluids

    OpenAIRE

    Källqvist, T.

    1990-01-01

    Two performance fluids were tested for toxic effects on marine algae and biological degradability. A fluid based on mineral oil was readily degradable (98% DOC removal in 28 days) while a either based oil degraded more slowly (56 % DOC removal in 28 days). The toxicity of both fluids was tested after emulsification of the oils in water and separating the oil and water phase after equilibration. The EC50 values obtained with this approach were 8.15 g/l for the oil based fluid and 116 g/l for t...

  4. Role of moving planes and moving spheres following Dupin cyclides

    KAUST Repository

    Jia, Xiaohong

    2014-03-01

    We provide explicit representations of three moving planes that form a μ-basis for a standard Dupin cyclide. We also show how to compute μ-bases for Dupin cyclides in general position and orientation from their implicit equations. In addition, we describe the role of moving planes and moving spheres in bridging between the implicit and rational parametric representations of these cyclides. © 2014 Elsevier B.V.

  5. Hydrodynamic simulations on a moving Voronoi mesh

    CERN Document Server

    Springel, Volker

    2011-01-01

    At the heart of any method for computational fluid dynamics lies the question of how the simulated fluid should be discretized. Traditionally, a fixed Eulerian mesh is often employed for this purpose, which in modern schemes may also be adaptively refined during a calculation. Particle-based methods on the other hand discretize the mass instead of the volume, yielding an approximately Lagrangian approach. It is also possible to achieve Lagrangian behavior in mesh-based methods if the mesh is allowed to move with the flow. However, such approaches have often been fraught with substantial problems related to the development of irregularity in the mesh topology. Here we describe a novel scheme that eliminates these weaknesses. It is based on a moving unstructured mesh defined by the Voronoi tessellation of a set of discrete points. The mesh is used to solve the hyperbolic conservation laws of ideal hydrodynamics with a finite volume approach, based on a second-order Godunov scheme with an exact Riemann solver. A...

  6. Textured fluids

    OpenAIRE

    Guenther, Gerhard K.

    1995-01-01

    The rheology and development morphology of textured fluids have been investigated. The first fluid considered in this work was a liquid crystalline polymer consisting of isotropic and anisotropic solutions of poly-p-phenyleneterephthalamide (PPT) in sulfuric acid. The second textured fluid considered in this work was an immiscible polymer blend consisting of poly(ethylene terephthalate) (PET) and nylon 6,6. The role played by liquid crystalline order (LCO) and a polydomain ...

  7. Luxury consumption moves East

    DEFF Research Database (Denmark)

    Khan, Omera

    2015-01-01

    Purpose – The literature contains relatively little prescriptive guidance for establishing supply chain strategies in the luxury fashion marketplace. The focus has been on fashion rather than luxury fashion and the purpose of this paper is to identify and explore the critical supply chain success...... novel insights to transformations in global supply chain strategy as luxury consumption is moving towards the east, which creates new challenges and demands for European manufacturers to respond, to sustaining a competitive advantage.......Purpose – The literature contains relatively little prescriptive guidance for establishing supply chain strategies in the luxury fashion marketplace. The focus has been on fashion rather than luxury fashion and the purpose of this paper is to identify and explore the critical supply chain success...... success factors to consider when developing a business strategy to enter the Chinese luxury fashion marketplace. Practical implications – The findings could guide managers that are developing a business case for entering the Chinese luxury fashion marketplace. Originality/value – This case study provides...

  8. ATLAS starts moving in

    CERN Multimedia

    Della Mussia, S

    2004-01-01

    The first large active detector component was lowered into the ATLAS cavern on 1st March. It consisted of the 8 modules forming the lower part of the central barrel of the tile hadronic calorimeter. The work of assembling the barrel, which comprises 64 modules, started the following day. Two road trailers each with 64 wheels, positioned side by side. This was the solution chosen to transport the lower part of the central barrel of ATLAS' tile hadronic calorimeter from Building 185 to the PX16 shaft at Point 1 (see Figure 1). The transportation, and then the installation of the component in the experimental cavern, which took place over three days were, to say the least, rather spectacular. On 25 February, the component, consisting of eight 6-metre modules, was loaded on to the trailers. The segment of the barrel was transported on a steel support so that it wouldn't move an inch during the journey. On 26 February, once all the necessary safety checks had been carried out, the convoy was able to leave Buildi...

  9. Move and eat better

    CERN Multimedia

    2012-01-01

    CERN has many traditions, but in a week that’s seen the launch of the Medical Service’s  ‘Move & eat better’ campaign, it’s refreshing to note that among the oldest is a sporting one.  The CERN relay race dates back to 15 October 1971 when 21 pioneering teams set off to pound the pavements of CERN. Back then, the Focus users group came in first with a time of 12 minutes and 42 seconds. Today’s route is slightly different, and the number of teams has risen to over 100, with a new category of Nordic Walking introduced, as part of the campaign, for the first time.   The relay has provided some memorable events, and perhaps one of the longest-standing records in the history of sport, with the UA1 strollers’ 10 minutes and 13 seconds unbeaten for thirty years. In the women’s category, the UN Gazelles set the fastest time of 13 minutes and 16 seconds in 1996, while in the veterans category, you wi...

  10. Cell survival studies for moving targets

    International Nuclear Information System (INIS)

    More than 330 patients with static tumors have been treated at GSI with a scanned C-12 beam. For targets that are subject to respiratory motion, treatment is not yet possible because target motion and scanning motion interfere. GSI is developing a motion compensation system to compensate target motion by adaptation of each individual Bragg peak position. Within this project, the GSI treatment planning software TRiP was extended to calculate physical dose distributions in the presence of motion. These motion extensions were experimentally validated. Recently we included the calculation of cell survival for moving targets. To validate the software, a program of experimental studies with biological samples has been started. In a first set of experiments, living cell cultures were placed on a periodically moving table and irradiated with and without motion compensation. Results are compared to reference cell cultures that were static during standard irradiations. Furthermore, measured cell survival distributions are compared to calculated distributions for all irradiation schemes

  11. 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

  12. Mixed hemimicelles solid-phase extraction based on sodium dodecyl sulfate (SDS)-coated nano-magnets for the spectrophotometric determination of Fingolomid in biological fluids

    Science.gov (United States)

    Azari, Zhila; Pourbasheer, Eslam; Beheshti, Abolghasem

    2016-01-01

    In this study, mixed hemimicelles solid-phase extraction (SPE) based on sodium dodecyl sulfate (SDS)-coated nano-magnets Fe3O4 was investigated as a novel method for the separation and determination of Fingolimod (FLM) in water, urine and plasma samples prior to spectrophotometeric determination. Due to the high surface area of these new sorbents and the excellent adsorption capacity after surface modification by SDS, satisfactory extraction recoveries can be produced. The main factors affecting the adsolubilization of analysts, such as pH, surfactant and adsorbent amounts, ionic strength, extraction time and desorption conditions were studied and optimized. Under the selected conditions, FLM has been quantitatively extracted. The accuracy of the method was evaluated by recovery measurements on spiked samples, and good recoveries of 96%, 95% and 88% were observed for water, urine and plasma respectively. Proper linear behaviors over the investigated concentration ranges of 2-26, 2-17 and 2-13 mg/L with good coefficients of determination, 0.998, 0.997 and 0.995 were achieved for water, urine and plasma samples, respectively. To the best of our knowledge, this is the first time that a mixed hemimicelles SPE method based on magnetic separation and nanoparticles has been used as a simple and sensitive method for monitoring of FLM in water and biological samples.

  13. Determination of Gemfibrozil (Lipitor and Lopid in Water, Biological Fluids and Drug Matrix by Dispersive Liquid-Liquid micro Extraction (DLLME and Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    Ghorbani A.

    2014-07-01

    Full Text Available In this study Dispersive liquid-liquid micro extraction (DLLME coupled with High performance liquid chromatography was applied for the determination of Gemfibrozil in water, drug`s matrix and biological liquids (human plasma and urine. In this method, the appropriate mixture of extraction solvent (200 μl chlorophorm and disperser solvent (1 ml methanol are injected rapidly into the aqueous sample (10.0 ml by syringe, cloudy solution is formed that consisted of fine particles of extraction solvent which is dispersed entirely into aqueous phase. The mixture was centrifuged and the extraction solvent is sedimented on the bottom of the conical test tube. 50 μl of the sedimented phase is puted in a vial and it`s solvent is evaporated. Then 1ml methanol injected to vial and 20 μL of it injected into the HPLC for separation and determination of Gemfibrozil. Some important parameters, such as kind of extraction and disperser solvent, volume of them, extraction time, pH and ionic strength of the aqueous feed solution were optimized. Under the optimum conditions, the enrichment factors and extraction recoveries were 10 and 93.64%. The linear range was (0.1-100.0 mgl-1, limit of detection was 12.3 mgl-1. The relative standard deviations (RSD for 2 mgl-1 of Gemfibrozil in water were 1.3%, (n=10.

  14. Fluid biopsy for circulating tumor cell identification in patients with early-and late-stage non-small cell lung cancer: a glimpse into lung cancer biology

    Science.gov (United States)

    Wendel, Marco; Bazhenova, Lyudmila; Boshuizen, Rogier; Kolatkar, Anand; Honnatti, Meghana; Cho, Edward H.; Marrinucci, Dena; Sandhu, Ajay; Perricone, Anthony; Thistlethwaite, Patricia; Bethel, Kelly; Nieva, Jorge; van den Heuvel, Michel; Kuhn, Peter

    2012-02-01

    Circulating tumor cell (CTC) counts are an established prognostic marker in metastatic prostate, breast and colorectal cancer, and recent data suggest a similar role in late stage non-small cell lung cancer (NSCLC). However, due to sensitivity constraints in current enrichment-based CTC detection technologies, there are few published data about CTC prevalence rates and morphologic heterogeneity in early-stage NSCLC, or the correlation of CTCs with disease progression and their usability for clinical staging. We investigated CTC counts, morphology and aggregation in early stage, locally advanced and metastatic NSCLC patients by using a fluid-phase biopsy approach that identifies CTCs without relying on surface-receptor-based enrichment and presents them in sufficiently high definition (HD) to satisfy diagnostic pathology image quality requirements. HD-CTCs were analyzed in blood samples from 78 chemotherapy-naïve NSCLC patients. 73% of the total population had a positive HD-CTC count (>0 CTC in 1 mL of blood) with a median of 4.4 HD-CTCs mL-1 (range 0-515.6) and a mean of 44.7 (±95.2) HD-CTCs mL-1. No significant difference in the medians of HD-CTC counts was detected between stage IV (n = 31, range 0-178.2), stage III (n = 34, range 0-515.6) and stages I/II (n = 13, range 0-442.3). Furthermore, HD-CTCs exhibited a uniformity in terms of molecular and physical characteristics such as fluorescent cytokeratin intensity, nuclear size, frequency of apoptosis and aggregate formation across the spectrum of staging. Our results demonstrate that despite stringent morphologic inclusion criteria for the definition of HD-CTCs, the HD-CTC assay shows high sensitivity in the detection and characterization of both early- and late-stage lung cancer CTCs. Extensive studies are warranted to investigate the prognostic value of CTC profiling in early-stage lung cancer. This finding has implications for the design of extensive studies examining screening, therapy and surveillance in

  15. Fluid biopsy for circulating tumor cell identification in patients with early-and late-stage non-small cell lung cancer: a glimpse into lung cancer biology

    International Nuclear Information System (INIS)

    Circulating tumor cell (CTC) counts are an established prognostic marker in metastatic prostate, breast and colorectal cancer, and recent data suggest a similar role in late stage non-small cell lung cancer (NSCLC). However, due to sensitivity constraints in current enrichment-based CTC detection technologies, there are few published data about CTC prevalence rates and morphologic heterogeneity in early-stage NSCLC, or the correlation of CTCs with disease progression and their usability for clinical staging. We investigated CTC counts, morphology and aggregation in early stage, locally advanced and metastatic NSCLC patients by using a fluid-phase biopsy approach that identifies CTCs without relying on surface-receptor-based enrichment and presents them in sufficiently high definition (HD) to satisfy diagnostic pathology image quality requirements. HD-CTCs were analyzed in blood samples from 78 chemotherapy-naïve NSCLC patients. 73% of the total population had a positive HD-CTC count (>0 CTC in 1 mL of blood) with a median of 4.4 HD-CTCs mL−1 (range 0–515.6) and a mean of 44.7 (±95.2) HD-CTCs mL−1. No significant difference in the medians of HD-CTC counts was detected between stage IV (n = 31, range 0–178.2), stage III (n = 34, range 0–515.6) and stages I/II (n = 13, range 0–442.3). Furthermore, HD-CTCs exhibited a uniformity in terms of molecular and physical characteristics such as fluorescent cytokeratin intensity, nuclear size, frequency of apoptosis and aggregate formation across the spectrum of staging. Our results demonstrate that despite stringent morphologic inclusion criteria for the definition of HD-CTCs, the HD-CTC assay shows high sensitivity in the detection and characterization of both early- and late-stage lung cancer CTCs. Extensive studies are warranted to investigate the prognostic value of CTC profiling in early-stage lung cancer. This finding has implications for the design of extensive studies examining screening, therapy and

  16. Biology Education Research 2.0

    OpenAIRE

    Dolan, Erin L.

    2015-01-01

    Biology education research (BER) 2.0 has arrived, and is moving the BER community beyond showing that active learning works to understanding the individual and contextual factors that explain and influence biology teaching and learning.

  17. A Moving Frame Algorithm for High Mach Number Hydrodynamics

    CERN Document Server

    Trac, H; Trac, Hy; Pen, Ue-Li

    2004-01-01

    We present a new approach to Eulerian computational fluid dynamics that is designed to work at high Mach numbers encountered in astrophysical hydrodynamic simulations. The Eulerian fluid conservation equations are solved in an adaptive frame moving with the fluid where Mach numbers are minimized. The moving frame approach uses a velocity decomposition technique to define local kinetic variables while storing the bulk kinetic components in a smoothed background velocity field that is associated with the grid velocity. Gravitationally induced accelerations are added to the grid, thereby minimizing the spurious heating problem encountered in cold gas flows. Separately tracking local and bulk flow components allows thermodynamic variables to be accurately calculated in both subsonic and supersonic regions. A main feature of the algorithm, that is not possible in previous Eulerian implementations, is the ability to resolve shocks and prevent spurious heating where both the preshock and postshock Mach numbers are h...

  18. Voltammetric Studies of Propranolol and Hydrochlorothiazide Oxidation in Standard and Synthetic Biological Fluids Using a Nitrogen-Containing Tetrahedral Amorphous Carbon (ta-C:N) Electrode

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Nitrogen-containing tetrahedral amorphous carbon electrode for electroanalysis. • Electrochemical behavior of propranolol (PROP) and hydrochlorothiazide (HTZ). • ta-C:N electrode presents good electrochemical performance for PROP and HTZ. • Electrochemical performance of ta-C:N electrode is similar to the BDD electrode. • PROP and HTZ are simultaneously quantified in artificial biological samples. - Abstract: The electrochemical detection of two pharmaceuticals, propranolol (PROP) and hydrochlorothiazide (HTZ), was studied using a nitrogen-containing tetrahedral amorphous carbon (ta-C:N) electrode. Measurements were also made using a boron-doped diamond (BDD) electrode, for comparison. The ta-C:N electrode functioned well for the simultaneous determination of PROP and HTZ in artificial urine and serum by square-wave voltammetry, both of which were detected at high positive potentials. The PROP (ca. 1.2 V) and HTZ (ca. 1.4 V) oxidation peak potentials were separated by about 200 mV. The respective analytical response curves presented good linearity in the investigated concentration range from 0.9 to 9.8 μmol L−1 for PROP and from 3.0 to 9.8 μmol L−1 for HTZ with calculated limits of detection (S/N = 3) of 0.75 μmol L−1 (∼194 ng/mL) for PROP and 2.50 μmol L−1 (∼744 ng/mL) for HTZ. Essentially, the lowest concentration measured voltammetrically was the LOD. The results indicate that the ta-C:N electrode could be an excellent new carbon material for electrochemically-active analytes requiring high potentials for detection

  19. Visual Simulation of Multiple Unmixable Fluids

    Institute of Scientific and Technical Information of China (English)

    Wen Zheng; Jun-Hai Yong; Jean-Claude Paul

    2007-01-01

    We present a novel grid-based method for simulating multiple unmixable fluids moving and interacting.Unlike previous methods that can only represent the interface between two fluids (usually between liquid and gas), this method can handle an arbitrary number of fluids through multiple independent level sets coupled with a constrain condition.To capture the fluid surface more accurately, we extend the particle level set method to a multi-fluid version.It shares the advantages of the particle level set method, and has the ability to track the interfaces of multiple fluids.To handle the dynamic behavior of different fluids existing together, we use a multiphase fluid formulation based on a smooth weight function.

  20. 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....

  1. Finite Element Analysis of Fluid-Conveying Timoshenko Pipes

    Directory of Open Access Journals (Sweden)

    Chih-Liang Chu

    1995-01-01

    Full Text Available A general finite element formulation using cubic Hermitian interpolation for dynamic analysis of pipes conveying fluid is presented. Both the effects of shearing deformations and rotary inertia are considered. The development retains the use of the classical four degrees-of-freedom for a two-node element. The effect of moving fluid is treated as external distributed forces on the support pipe and the fluid finite element matrices are derived from the virtual work done due to the fluid inertia forces. Finite element matrices for both the support pipe and moving fluid are derived and given explicitly. A numerical example is given to demonstrate the validity of the model.

  2. Congestion and residential moving behaviour

    DEFF Research Database (Denmark)

    Larsen, Morten Marott; Pilegaard, Ninette; Van Ommeren, Jos

    2008-01-01

    we study how congestion and residential moving behaviour are interrelated, using a two-region job search model. Workers choose between interregional commuting and residential moving, in order to live closer to their place of work. This choice affects the external costs of commuting, due to...

  3. Shielding of moving line charges

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Youmei; He, Bingyu [Department of Physics, School of Science, Hangzhou Dianzi University, Hangzhou 310018 (China); Yu, Wei [Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Yu, M.Y., E-mail: myyu@zju.edu.cn [Institute for Fusion Theory and Simulation and Department of Physics, Zhejiang University, Hangzhou 310027 (China); Institute for Theoretical Physics I, Ruhr University, D-44780 Bochum (Germany)

    2015-07-03

    A charged object moving in plasma can excite plasma waves that inevitably modify its Debye shielding characteristics. When the excited waves propagate sufficiently fast, the shielding can even break down. Here the properties of finite amplitude plasma waves excited by a moving line charge are investigated. It is found that when the speed of the latter is close to but less than the thermal speed of the background plasma electrons, only a localized disturbance in the form of a soliton that moves together with the line charge is excited. That is, the line charge is well shielded even though it is moving at a high speed and has generated a large local electrostatic field. However, for a pair of line charges moving together, such complete shielding behavior could not be found.

  4. Fluid dynamics of dilatant fluid

    DEFF Research Database (Denmark)

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

    2012-01-01

    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......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...... 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...

  5. Fluid juggling

    CERN Document Server

    Soto, Enrique

    2013-01-01

    This fluid dynamics video is an entry for the Gallery of Fluid Motion for the 66th Annual Meeting of the Fluid Dynamics Division of the American Physical Society. We show the curious behaviour of a light ball interacting with a liquid jet. For certain conditions, a ball can be suspended into a slightly inclined liquid jet. We studied this phenomenon using a high speed camera. The visualizations show that the object can be `juggled' for a variety of flow conditions. A simple calculation showed that the ball remains at a stable position due to a Bernoulli-like effect. The phenomenon is very stable and easy to reproduce.

  6. Fluid Shifts

    Science.gov (United States)

    Stenger, M.; Hargens, A.; Dulchavsky, S.; Ebert, D.; Lee, S.; Lauriie, S.; Garcia, K.; Sargsyan, A.; Martin, D.; Ribeiro, L.; Lui, J.; Macias, B.; Arbeille, P.; Danielson, R.; Chang, D.; Johnston, S.; Ploutz-Snyder, R.; Smith, S.

    2016-01-01

    NASA is focusing on 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 more than 50% of ISS astronauts experienced more profound, chronic changes with objective structural and functional findings such as papilledema and choroidal folds. Globe flattening, optic nerve sheath dilation, and optic nerve tortuosity also are apparent. This pattern is referred to as the visual impairment and intracranial pressure (VIIP) syndrome. VIIP signs and symptoms, as well as postflight lumbar puncture data, suggest that elevated intracranial pressure (ICP) may be associated with the 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 correlate these findings 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 the VIIP-related effects of those shifts, is predicted by the crewmember's preflight conditions and responses to acute hemodynamic manipulations (such as head-down tilt). Lastly, we will evaluate the patterns of fluid distribution in ISS astronauts during acute reversal of fluid shifts through application of lower body negative pressure (LBNP) interventions to characterize and explain general and individual responses. 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, calcaneus tissue thickness (by

  7. 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.

  8. Existence of time-periodic weak solutions to the stochastic Navier-Stokes equations around a moving body

    International Nuclear Information System (INIS)

    The existence of time-periodic stochastic motions of an incompressible fluid is obtained. Here the fluid is subject to a time-periodic body force and an additional time-periodic stochastic force that is produced by a rigid body moves periodically stochastically with the same period in the fluid

  9. Locomotion in complex fluids: Integral theorems

    CERN Document Server

    Lauga, Eric

    2014-01-01

    The biological fluids encountered by self-propelled cells display complex microstructures and rheology. We consider here the general problem of low-Reynolds number locomotion in a complex fluid. {Building on classical work on the transport of particles in viscoelastic fluids,} we demonstrate how to mathematically derive three integral theorems relating the arbitrary motion of an isolated organism to its swimming kinematics {in a non-Newtonian fluid}. These theorems correspond to three situations of interest, namely (1) squirming motion in a linear viscoelastic fluid, (2) arbitrary surface deformation in a weakly non-Newtonian fluid, and (3) small-amplitude deformation in an arbitrarily non-Newtonian fluid. Our final results, valid for a wide-class of {swimmer geometry,} surface kinematics and constitutive models, at most require mathematical knowledge of a series of Newtonian flow problems, and will be useful to quantity the locomotion of biological and synthetic swimmers in complex environments.

  10. Dynamic response of a poroelastic stratum to moving oscillating load

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The dynamic response of a poroelastic stratum subjected to moving load is studied. The governing dynamic equations for poroelastic medium are solved by using Fourier transform. The general solutions for the stresses and displacements in the transformed domain are established. Based on the general solutions, with the consideration of boundary conditions, the final expressions of stresses and displacements in physical domain are put forward for the three-dimensional single-layer medium. Some numerical solutions for the stresses, displacements and pore fluid pressure are presented and reveal that the response of a poroelastic stratum varies obviously with the moving velocity.

  11. Dynamic response of a poroelastic stratum to moving oscillating load

    Institute of Scientific and Technical Information of China (English)

    CHEN YuanGuo; JIN Bo

    2008-01-01

    The dynamic response of a poroelastic stratum subjected to moving load is studied.The governing dynamic equations for poroelasUc medium are solved by using Fourier transform. The general solutions for the stresses and displacements in the transformed domain are established. Based on the general solutions, with the consideration of boundary conditions, the final expressions of stresses and displacements in physical domain are put forward for the three-dimensional single-layer medium. Some numerical solutions for the stresses, displacements and pore fluid pressure are presented and reveal that the response of a poroelastic stratum varies obviously with the moving velocity.

  12. Squirming propulsion in viscoelastic fluids

    Science.gov (United States)

    de Corato, Marco; Greco, Francesco; Maffettone, Pier Luca

    2015-11-01

    The locomotion of organisms in Newtonian fluids at low-Reynolds numbers displays very different features from that at large Reynolds numbers; indeed, in this regime the viscous forces are dominant over the inertial ones and propulsion is possible only with non-time-reversible swimming strokes. In many situations of biological interest, however, small organisms are propelling themselves through non-Newtonian fluids such as mucus or biofilms, which display highly viscoelastic properties. Fluid viscoelasticity affects in a complex way both the micro-organisms' swimming velocity and dissipated power, possibly affecting their collective behavior. In our work, we employ the so called ``squirmer'' model to study the motion of spherical ciliated organisms in a viscoelastic fluid. We derive analytical formulas for the squirmer swimming velocity and dissipated power that show a complex interplay between the fluid constitutive behavior and the propulsion mechanism.

  13. Fluid Flow Phenomena during Welding

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wei [ORNL

    2011-01-01

    MOLTEN WELD POOLS are dynamic. Liquid in the weld pool in acted on by several strong forces, which can result in high-velocity fluid motion. Fluid flow velocities exceeding 1 m/s (3.3 ft/s) have been observed in gas tungsten arc (GTA) welds under ordinary welding conditions, and higher velocities have been measured in submerged arc welds. Fluid flow is important because it affects weld shape and is related to the formation of a variety of weld defects. Moving liquid transports heat and often dominates heat transport in the weld pool. Because heat transport by mass flow depends on the direction and speed of fluid motion, weld pool shape can differ dramatically from that predicted by conductive heat flow. Temperature gradients are also altered by fluid flow, which can affect weld microstructure. A number of defects in GTA welds have been attributed to fluid flow or changes in fluid flow, including lack of penetration, top bead roughness, humped beads, finger penetration, and undercutting. Instabilities in the liquid film around the keyhole in electron beam and laser welds are responsible for the uneven penetration (spiking) characteristic of these types of welds.

  14. Study of moving reflector vibrations

    International Nuclear Information System (INIS)

    The results on the experimental study of occasional vibrations of the IBR-2 moving reflectors are given. The influence of the moving reflector structure, the level of their axial and phase oscillations and periods of reflector rotation on the external reactivity fluctuations is analysed. The methods of the statistical analysis of the stationary bicomponent time series are used for experimental data processing. It is shown that at the period of the IBR-2 energy start-up the uncontrolled reactivity fluctuations due to the moving reflector vibrations were rather insignificant (4.5+-2.7x10-6 δ K/K). The construction of the reactivity modulator with the moving reflector as trident provides the regular reactor operation in the mean power range of 0-2 MeV

  15. NPS MOVES - Entertainment Research Directions

    OpenAIRE

    Zyda, Michael

    2000-01-01

    Outline: Zyda Bio in Book Covers, NRC report & its impact on VR/CG research, The future of networked entertainment, Research required by entertainment & defense to provide this future, The NPS MOVES Research Center & its Entertainment/Defense Agenda ...

  16. Transient heating of moving objects

    Directory of Open Access Journals (Sweden)

    E.I. Baida

    2014-06-01

    Full Text Available A mathematical model of transient and quasistatic heating of moving objects by various heat sources is considered. The mathematical formulation of the problem is described, examples of thermal calculation given.

  17. Rehabilitation Counselor Certification: Moving Forward

    Science.gov (United States)

    Saunders, Jodi L.; Barros-Bailey, Mary; Chapman, Cindy; Nunez, Patricia

    2009-01-01

    This article provides a brief history of the Commission on Rehabilitation Counselor Certification and presents recent changes and strategic goals for moving forward. Challenges and opportunities for the profession in relation to certification are also discussed. (Contains 3 tables.)

  18. How Moving Backgrounds Influence Interception

    OpenAIRE

    Eli Brenner; Smeets, Jeroen B. J.

    2015-01-01

    Reaching movements towards an object are continuously guided by visual information about the target and the arm. Such guidance increases precision and allows one to adjust the movement if the target unexpectedly moves. On-going arm movements are also influenced by motion in the surrounding. Fast responses to motion in the surrounding could help cope with moving obstacles and with the consequences of changes in one's eye orientation and vantage point. To further evaluate how motion in the surr...

  19. Autowaves in moving excitable media

    Directory of Open Access Journals (Sweden)

    V.A.Davydov

    2004-01-01

    Full Text Available Within the framework of kinematic theory of autowaves we suggest a method for analytic description of stationary autowave structures appearing at the boundary between the moving and fixed excitable media. The front breakdown phenomenon is predicted for such structures. Autowave refraction and, particulary, one-side "total reflection" at the boundary is considered. The obtained analytical results are confirmed by computer simulations. Prospects of the proposed method for further studies of autowave dynamics in the moving excitable media are discussed.

  20. 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

  1. Moving Shadows, Moving Sun. Early Modem Sundials Restaging Miracles.

    Science.gov (United States)

    Mersmann, Jasmin

    2015-01-01

    Irrespective of geo- or heliocentric presuppositions, the functioning of sundials is based on the observation of moving shadows or light spots. Even though the cast shadow was often simply used to indicate the time, it could also remind the users of the ephemerality of earthly things or function as an index of planetary movements. This article examines the various ways in which early modem sundials visually interpret the moving shadow or light spot. The instruments address the shadow in inscriptions, integrate it into their design (e.g., in cruciform dials) or even manipulate its course (as in the so-called Horologium Ahaz). Both the crucifix and the Ahaz dials not only refer to astronomical miracles but actually restage them. Even though by means of the horologium it was not possible to explain the Old Testament miracle of the shadow moving backward, adepts were able to recreate it on a terrestrial scale. PMID:26495586

  2. Fabrication of ciprofloxacin molecular imprinted polymer coating on a stainless steel wire as a selective solid-phase microextraction fiber for sensitive determination of fluoroquinolones in biological fluids and tablet formulation using HPLC-UV detection.

    Science.gov (United States)

    Mirzajani, Roya; Kardani, Fatemeh

    2016-04-15

    A molecularly imprinted polymer (MIP) fiber on stainless steel wire using ciprofloxacin template with a mild template removal condition was synthetized and evaluated for fiber solid phase microextraction (SPME) of fluoroquinolones (FQs) from biological fluids and pharmaceutical samples, followed by high performance liquid chromatography analysis with UV detection (HPLC-UV). The developed MIP fiber exhibited high selectivity for the analytes in complex matrices. The coating of the fibers were inspected using fourier transform infrared spectrophotometry, thermogaravimetric analysis, energy dispersive X-ray (EDX) spectroscopy as well as by scanning electron microscopy (SEM). The fiber shows high thermal stability (up to 300°C), good reproducibility and long lifetime. The composite coating did not swell in organic solvents nor did it strip off from the substrate. It was also highly stable and extremely adherent to the surface of the stainless steel fiber. The fabricated fiber exclusively exhibited excellent extraction efficiency and selectivity for some FQs. The effective parameters influencing the microextraction efficiency such as pH, extraction time, desorption condition, and stirring rate were investigated. Under optimized conditions, the limits of detection of the four FQs ranged from 0.023-0.033 μg L(-1) (S/N=5) and the calibration graphs were linear in the concentration range from 0.1-40 μg L(-1), the inter-day and intraday relative standard deviations (RSD) for various FQs at three different concentration level (n=5) using a single fiber were 1.1-4.4% and the fiber to fiber RSD% (n=5) was 4.3-6.7% at 5 μg L(-1) of each anlyetes. The method was successfully applied for quantification of FQs in real samples including serum, plasma and tablet formulation with the recoveries between 97 to 102%. PMID:26852159

  3. Explaining immigrants’ moves into homeownership

    DEFF Research Database (Denmark)

    Andersen, Hans Skifter

    In the paper is examined the reasons for when and why immigrants in Greater Copenhagen move into homeownership after their 25th year based on data from the years 1990 to 2008 compared to residents with a Danish background. As for natives homeownership to a large extent is dependent on income......, employment and family situation, and actual changes, but the importance of these factors differ from Danes. Different immigrant groups have a somewhat lower propensity to move into homeownership than Danes, which only to some extent can be explained by differences in income, education and employment. Living...... in social housing and in multi-ethnic neighbourhoods reduces the probability of moving into homeownership. But there are still some unexplained reasons for lower homeownership rate among immigrants. A probable hypothesis is that immigrants are more uncertain about their future employment and income...

  4. Matters on a moving brane

    CERN Document Server

    Koivisto, Tomi Sebastian

    2013-01-01

    A novel generalisation of the Dirac-Born-Infeld string scenario is described. It is shown that matter residing on the moving brane is dark and has the so-called disformal coupling to gravity. This gives rise to cosmologies where dark matter stems from the oscillations of the open strings along the brane and the transverse oscillations result in dark energy. Furthermore, due to a new screening mechanism that conceals the fifth force from local experiments, one may even entertain the possibility that the visible sector is also moving along the extra dimensions.

  5. Bridging the gaps in systems biology

    OpenAIRE

    Marija Cvijovic; Joachim Almquist; Jonas Hagmar; Stefan Hohmann; Hans\\u2011Michael Kaltenbach; Edda Klipp; Marcus Krantz; Pedro Mendes; Sven Nelander; Jens Nielsen; Andrea Pagnani; Natasa Przulj; Andreas Raue; J\\xf6rg Stelling; Szymon Stoma

    2014-01-01

    International audience Systems biology aims at creating mathematical models, i.e., computational reconstructions of biological systems and processes that will result in a new level of understanding-the elucidation of the basic and presumably conserved "design" and "engineering" principles of biomolecular systems. Thus, systems biology will move biology from a phenomenological to a predictive science. Mathematical modeling of biological networks and processes has already greatly improved ou...

  6. Biological Threats

    Science.gov (United States)

    ... Workplace Plans School Emergency Plans Main Content Biological Threats Biological agents are organisms or toxins that can ... for Disease Control and Prevention . Before a Biological Threat Unlike an explosion, a biological attack may or ...

  7. 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.

  8. Peristaltic transport of Conducting Bingham fluid in contact with a Newtonian fluid in a channel

    Directory of Open Access Journals (Sweden)

    M.Arun kumar

    2013-04-01

    Full Text Available Peristaltic pumping by a sinusoidal traveling wave in the walls of a two dimensional channel filled with two immiscible fluids with magnetic effect is investigated. The core region of the channel is occupied by a Bingham fluid where as the peripheral region is occupied by a Newtonian fluid. The flow is examined in a wave frame of reference moving with the velocity of the wave. The expressions for the stream function, the velocity and the pressure rise are obtained. The equation for the interface separating the two fluids is obtained. Numerical results are reported for several of the physical parameters of interest. We observed that the lower values of

  9. Improving the structure MCMC sampler for Bayesian networks by introducing a new edge reversal move

    NARCIS (Netherlands)

    Grzegorczyk, Marco; Husmeier, Dirk

    2008-01-01

    Applications of Bayesian networks in systems biology are computationally demanding due to the large number of model parameters. Conventional MCMC schemes based on proposal moves in structure space tend to be too slow in mixing and convergence, and have recently been superseded by proposal moves in t

  10. 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...

  11. Differential equations and moving frames

    OpenAIRE

    Abib, Odinette Renée

    2006-01-01

    The purpose of the paper is to study the relationship between differential equations, Pfaffian systems and geometric structures, via the method of moving frames of E.Cartan. We show a local structure theorem. The Lie algebra aspects differential equations is studied too.

  12. Carlson Wagonlit Travel is moving

    CERN Multimedia

    2013-01-01

    The renovation of the Main Building continues!   Because of this, Carlson Wagonlit Travel will move from building 62 to building 510 on 4 October and the agency will be closed in the afternoon. An emergency service will be organised for official travels only. Phone: 022 799 75 73 & 022 799 75 78 / e-mail: cern@carlsonwagonlit.ch

  13. Moving and Touching on Ruin

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Yes, the earthquake is a desper-ate disaster to China, but what we could see from this havoc is far more than ruin itself. Every story under the name of love touched our hearts and souls. With their moving and touching voices hovering above the seis-mic zone, let's dry our tears and do our best to rebuild the land of abundance...

  14. Moving ring reactor 'Karin-1'

    International Nuclear Information System (INIS)

    The conceptual design of a moving ring reactor ''Karin-1'' has been carried out to advance fusion system design, to clarify the research and development problems, and to decide their priority. In order to attain these objectives, a D-T reactor with tritium breeding blanket is designed, a commercial reactor with net power output of 500 MWe is designed, the compatibility of plasma physics with fusion engineering is demonstrated, and some other guideline is indicated. A moving ring reactor is composed mainly of three parts. In the first formation section, a plasma ring is formed and heated up to ignition temperature. The plasma ring of compact torus is transported from the formation section through the next burning section to generate fusion power. Then the plasma ring moves into the last recovery section, and the energy and particles of the plasma ring are recovered. The outline of a moving ring reactor ''Karin-1'' is described. As a candidate material for the first wall, SiC was adopted to reduce the MHD effect and to minimize the interaction with neutrons and charged particles. The thin metal lining was applied to the SiC surface to solve the problem of the compatibility with lithium blanket. Plasma physics, the engineering aspect and the items of research and development are described. (Kako, I.)

  15. 2002 in the MOVES Institute

    OpenAIRE

    Zyda, Michael

    2002-01-01

    The MOVES Institute’s mission is research, application, and education in the grand challenges of modeling, virtual environments, and simulation. Our specialties are 3D visual simulation, networked virtual environments, computer-generated autonomy, human-performance engineering, immersive technologies, defense/entertainment collaboration, and evolving operational modeling.

  16. Theory of Volumetric Moving Dislocation in Poroelastic Halfspace and Characterization of Magma Intrusion Events

    Institute of Scientific and Technical Information of China (English)

    Ouyang Zhihua; Elsworth Derek; Sheng Jianlong

    2005-01-01

    The undrained change in pore fluid pressure that accompanies dike intrusion may be conveniently represented as a moving volumetric dislocation. The concept of a dilation center was developed to represent the field of undrained pressure change in a saturated linear elastic medium. Since instantaneous pore fluid pressures can be developed to a considerable distance from the dislocation, monitoring the rate of pressure generation and subsequent pressure dissipation in a fully coupled manner enables certain characteristics of the resulting dislocation to be defined. The principal focus of this study is the application of dislocation-based methods to analyze the behavior of the fluid pressure response induced by intrusive dislocations in a semi-infinite space, such as dike intrusion, hydraulic fracturing and piezometer insertion. Partially drained pore pressures result from the isothermal introduction of volumetric moving pencil-like dislocations described as analogs to moving point dislocation within a semi-infinite saturated elastic medium. To represent behavior within the halfspace, an image dislocation is positioned under the moving coordinate frame fixed to the front of the primary moving dislocation, to yield an approximate solution for pore pressure for constant fluid pressure conditions. Induced pore pressures are concisely described under a minimum set of dimensionless parameter groupings representing propagation velocity, and relative geometry. Charts defining induced pore fluid pressure at a static measuring point provide a meaningful tool for determining unknown parameters in data reduction. Two intrusive events at Krafla, Iceland are examined using the type curve matching techniques. Predicted parameters agree favorably with field data.

  17. Translating Cuba: Diasporic writing between moving cultures and moving media

    Directory of Open Access Journals (Sweden)

    Andrea Gremels

    2015-04-01

    Full Text Available This article discusses the interrelation between transculturality and transmediality with an emphasis on processes of translation. It focuses on two examples of transcultural and transmedial writing taken from contemporary Cuban literature in Paris: Miguel Sales's recontextualization of Cuban popular music in Paris and William Navarrete's ekphrastic reinscription of his island into the realm of French romantic painting. The case studies are significant in this context because they show how cultural borders are simultaneously set and transgressed at medial crossings—between music and poetry, text, and image. Thus, cultural translations go hand in hand with medial transpositions that include forms of rewriting, recomposition, and revisualization. The connection between moving cultures and moving media also points to the question of “travelling memory” in diaspora.

  18. Flow Diode and Method for Controlling Fluid Flow Origin of the Invention

    Science.gov (United States)

    Dyson, Rodger W (Inventor)

    2015-01-01

    A flow diode configured to permit fluid flow in a first direction while preventing fluid flow in a second direction opposite the first direction is disclosed. The flow diode prevents fluid flow without use of mechanical closures or moving parts. The flow diode utilizes a bypass flowline whereby all fluid flow in the second direction moves into the bypass flowline having a plurality of tortuous portions providing high fluidic resistance. The portions decrease in diameter such that debris in the fluid is trapped. As fluid only travels in one direction through the portions, the debris remains trapped in the portions.

  19. A coupled Immersed Boundary-Lattice Boltzmann method for incompressible flows through moving porous media

    Science.gov (United States)

    Pepona, Marianna; Favier, Julien

    2016-09-01

    In this work, we propose a numerical framework to simulate fluid flows in interaction with moving porous media of complex geometry. It is based on the Lattice Boltzmann method including porous effects via a Brinkman-Forchheimer-Darcy force model coupled to the Immersed Boundary method to handle complex geometries and moving structures. The coupling algorithm is described in detail and it is validated on well-established literature test cases for both stationary and moving porous configurations. The proposed method is easy to implement and efficient in terms of CPU cost and memory management compared to alternative methods which can be used to deal with moving immersed porous media, e.g. re-meshing at each time step or use of a moving/chimera mesh. An overall good agreement was obtained with reference results, opening the way to the numerical simulation of moving porous media for flow control applications.

  20. Pumping by flapping in a viscoelastic fluid

    CERN Document Server

    Pak, On Shun

    2010-01-01

    In a world without inertia, Purcell's scallop theorem states that in a Newtonian fluid a time-reversible motion cannot produce any net force or net flow. Here we consider the extent to which the nonlinear rheological behavior of viscoelastic fluids can be exploited to break the constraints of the scallop theorem in the context of fluid pumping. By building on previous work focusing on force generation, we consider a simple, biologically-inspired geometrical example of a flapper in a polymeric (Oldroyd-B) fluid, and calculate asymptotically the time-average net fluid flow produced by the reciprocal flapping motion. The net flow occurs at fourth order in the flapping amplitude, and suggests the possibility of transporting polymeric fluids using reciprocal motion in simple geometries even in the absence of inertia. The induced flow field and pumping performance are characterized and optimized analytically. Our results may be useful in the design of micro-pumps handling complex fluids.

  1. A Framework for Representing Moving Objects

    DEFF Research Database (Denmark)

    Becker, Ludger; Blunck, Henrik; Hinrichs, Klaus;

    2004-01-01

    We present a framework for representing the trajectories of moving objects and the time-varying results of operations on moving objects. This framework supports the realization of discrete data models of moving objects databases, which incorporate representations of moving objects based on non-li...

  2. Direct Numerical Simulation of Complex Multi-Fluid Flows Using a Combined Volume of Fluid and Immersed Boundary Method

    NARCIS (Netherlands)

    Deen, Niels G.; Sint Annaland, van Martin; Kuipers, J.A.M.

    2007-01-01

    In this paper a simulation model is presented for the Direct Numerical Simulation (DNS) of complex multi-fluid flows in which simultaneously (moving) deformable (drops or bubbles) and non-deformable (moving) elements (particles) are present, possibly with the additional presence of free surfaces. Ou

  3. Pericardial Fluid Analysis

    Science.gov (United States)

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

  4. Peritoneal Fluid Analysis

    Science.gov (United States)

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

  5. Nordic Seniors on the Move

    DEFF Research Database (Denmark)

    above gives voice to one of these seniors, stressing the necessity of moving. The anthology contributes to the international body of literature about later life migration, specifically representing experiences made by Nordic seniors. As shown here, mobility and migration in later life have implications...... for identities, traditions, feelings of belonging, family and friends, health, images of old age, societal planning and policies, and even for religious attachment. The book presents a joint statement, intended for international scholars in the field, but also for Nordic policymakers and practitioners...... involved in the daily life and needs of the people who move in later life. The editors Anne Leonora Blaakilde and Gabriella Nilsson are both ethnologists affiliated with the Department of Media, Cognition and Communication, University of Copenhagen, Denmark and the Department of Arts and Cultural Sciences...

  6. Moved by a Rapid Transit

    Science.gov (United States)

    Bueter, C.

    2013-04-01

    Enticing by virtue of its predictability, historical utility, and spectacle, the transit of Venus is a niche event among astronomical phenomena. Though the value of a transit for scientific purposes is now diminished, the brief appearance of Venus silhouetted against the background of the Sun in 2004 moved the artistic community to celebrate the rare alignment. Artists of all ages combined old traditions with fresh technology to create a 21st-century tapestry of music, sculpture, paintings, glasswork, quilts, sky shows, and digital imagery. A full catalog of transit-related art generated over the centuries would feature the sampling of entries presented here and at the Moved by a Rapid Transit website.

  7. Congestion and Residential Moving Behaviour

    OpenAIRE

    Larsen, Morten Marott; Pilegaard, Ninette; van Ommeren, Jos

    2004-01-01

    In this paper we study how congestion and residential movingbehaviour are interrelated using a two-region job search model. Workerschoose optimally between interregional commuting and residential movingto live closer to the place of work. This choice affects the external costs ofcommuting due to congestion. The welfare maximizing road tax is derived.We demonstrate that road pricing may not only reduce congestion but alsoincrease total residential moving costs in the economy. One of the mainco...

  8. Moving Forest di Expo 2015

    OpenAIRE

    Michela Moretti

    2015-01-01

    The paper proposes a reading of the Expo 2015 landscape project through the essay "Moving Forest "by Franco Zagari and Benedetto Selleri; in which the authors trace the design process of the exposition site. It describes the design features of the green spaces that surround and mark the Exposition City. The green project is the connection between innovation, technology and rural landscape, like that surrounds the site. The Expo map represents one of the largest landscape projects in the last ...

  9. Moving Walkways, Escalators, and Elevators

    OpenAIRE

    Cardinal, J.; Collette, S; Hurtado, F.; Langerman, S.; Palop, B.

    2007-01-01

    We study a simple geometric model of transportation facility that consists of two points between which the travel speed is high. This elementary definition can model shuttle services, tunnels, bridges, teleportation devices, escalators or moving walkways. The travel time between a pair of points is defined as a time distance, in such a way that a customer uses the transportation facility only if it is helpful. We give algorithms for finding the optimal location of such a transportation facili...

  10. IKAR moves to higher energies

    CERN Multimedia

    1979-01-01

    The measurements of hadron elastic scattering on protons at small angle (WA9 experiment) were extended at higher energies (NA8 experiment by the Clermont Ferrand-Leningrad-Lyon-Uppsala Collaboration). To this purpose the set-up was moved to the beam H8 in the EHN1 Hall of the SPS North Area. The photo shows the ionization chamber measuring the recoil energy (centre). Pierre Sahuc stands on the left.

  11. Robotics and Biology: Lets get Physical

    Science.gov (United States)

    Choset, Howie

    Our research group investigates the core fundamentals of locomotion as it exists in biology and as it applies to locomoting robotic systems. Initially, our work advanced techniques found in geometric mechanics to design cyclic controllers, often called gaits, for snake robots, highly articulated mechanisms that can thread through tightly packed spaces to access locations people cannot. We had considerable success in designing snake robot gaits, but found our systems stymied in terrains characterized by sandy substrates. Sandy terrains and other granular media pose a challenge to snake robots because it is unclear how the mechanism interacts with environment: we cannot simply assume the robot is on hard-ground nor in a fluid. Simulating granular interactions can prove to be computationally intractable for real-time use on the robots. Therefore, we developed experimental tools that allowed us to sieve out models of the locomoting systems operating on granular media. We were then able to bring these models into harmony with the elegant formulation of our geometric mechanics approach. This allowed us to derive adaptive controllers for our snake robots in sandy terrains, and enabled us to gain deeper insight into of how biological systems move over similar terrains as well.

  12. Holographic Fluids with Vorticity and Analogue Gravity

    CERN Document Server

    Leigh, Robert G; Petropoulos, P Marios

    2012-01-01

    We study holographic three-dimensional fluids with vorticity in local equilibrium and discuss their relevance to analogue gravity systems. The Fefferman-Graham expansion leads to the fluid's description in terms of a comoving and rotating Papapetrou-Randers frame. A suitable Lorentz transformation brings the fluid to the non-inertial Zermelo frame, which clarifies its interpretation as moving media for light/sound propagation. We apply our general results to the Lorentzian Kerr-AdS_4 and Taub-NUT-AdS_4 geometries that describe fluids in cyclonic and vortex flows respectively. In the latter case we associate the appearance of closed timelike curves to analogue optical horizons. In addition, we derive the classical rotational Hall viscosity of three-dimensional fluids with vorticity. Our formula remarkably resembles the corresponding result in magnetized plasmas.

  13. Auxillary Fluid Flowmeter

    DEFF Research Database (Denmark)

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

    2010-01-01

    The Auxiliary Fluid Flow meter is proposed to measure the fluid flow of any kind in both pipes and open channels. In this kind of flow measurement, the flow of an auxiliary fluid is measured Instead of direct measurement of the main fluid flow. The auxiliary fluid is injected into the main fluid ...

  14. Research on moving object detection based on frog's eyes

    Science.gov (United States)

    Fu, Hongwei; Li, Dongguang; Zhang, Xinyuan

    2008-12-01

    On the basis of object's information processing mechanism with frog's eyes, this paper discussed a bionic detection technology which suitable for object's information processing based on frog's vision. First, the bionics detection theory by imitating frog vision is established, it is an parallel processing mechanism which including pick-up and pretreatment of object's information, parallel separating of digital image, parallel processing, and information synthesis. The computer vision detection system is described to detect moving objects which has special color, special shape, the experiment indicates that it can scheme out the detecting result in the certain interfered background can be detected. A moving objects detection electro-model by imitating biologic vision based on frog's eyes is established, the video simulative signal is digital firstly in this system, then the digital signal is parallel separated by FPGA. IN the parallel processing, the video information can be caught, processed and displayed in the same time, the information fusion is taken by DSP HPI ports, in order to transmit the data which processed by DSP. This system can watch the bigger visual field and get higher image resolution than ordinary monitor systems. In summary, simulative experiments for edge detection of moving object with canny algorithm based on this system indicate that this system can detect the edge of moving objects in real time, the feasibility of bionic model was fully demonstrated in the engineering system, and it laid a solid foundation for the future study of detection technology by imitating biologic vision.

  15. Effects of fluid velocity gradients on heavy quark energy loss

    International Nuclear Information System (INIS)

    We use holographic duality to analyze the drag force on, and consequent energy loss of, a heavy quark moving through a strongly coupled conformal fluid with non-vanishing gradients in its velocity and temperature. We derive the general expression for the drag force to first order in the fluid gradients. Using this general expression, we show that a quark that is instantaneously at rest, relative to the fluid, in a fluid whose velocity is changing with time feels a nonzero force. And, we show that for a quark that is moving ultra-relativistically, the first order gradient “corrections” become larger than the zeroth order drag force, suggesting that the gradient expansion may be unreliable in this regime. We illustrate the importance of the fluid gradients for heavy quark energy loss by considering a fluid with one-dimensional boost invariant Bjorken expansion as well as the strongly coupled plasma created by colliding sheets of energy

  16. Three-dimensional magnetic reconnection through a moving magnetic null

    Directory of Open Access Journals (Sweden)

    V. S. Lukin

    2011-11-01

    Full Text Available A computational study of three-dimensional magnetic reconnection between two flux ropes through a moving reconnection site is presented. The configuration is considered in the context of two interacting spheromaks constrained by a perfectly conducting cylindrical boundary and oriented to form a single magnetic field null at its center. The initial magnetic field configuration is embedded into a uniform thermal plasma and is unstable to tilting. As the spheromaks tilt, their magnetic fields begin to reconnect at the null, subsequently displacing both the null and the reconnection site. The motion of the reconnection region and the magnetic null are shown to be correlated, with stronger correlation and faster reconnection observed in plasmas with lower thermal to magnetic pressure ratio. It is also shown that ion inertial effects allow for yet faster reconnection, but do not qualitatively change the dynamics of the process. Implications of the coupling between moving magnetic nulls and reconnection sites, as well as of possible mechanisms for fast reconnection through a moving reconnection region, are discussed. The simulations are conducted using both single-fluid and Hall MHD plasma models within the HiFi multi-fluid modeling framework.

  17. Instrumental aspects of Simulated Moving Bed chromatography.

    Science.gov (United States)

    Faria, Rui P V; Rodrigues, Alírio E

    2015-11-20

    The Simulated Moving Bed (SMB) is one of the greatest illustrations of the potential of continuous multicolumn counter-current chromatographic processes. Although it was initially developed for the purification of petrochemicals, the advances that this technology has experienced during more than 50 years of existence were at the basis of its successful expansion into the food and pharmaceuticals industries. In this context, the present work provides an overview of the evolution of SMB focused on the most relevant instrumental aspects related with this technology. For that purpose, the details of the design and construction of this equipment will be reviewed, with special attention to the valves design. Due to its increasing interest, the technical requirements imposed by unconventional operating modes will be addressed together with the design adaptations that allow the operation of SMB units with compressible fluids and the implementation of Hybrid-SMB processes. Finally, as SMB technology has been unable to meet all the process specifications within the growing biopharmaceuticals industry, the development of alternative multicolumn counter-current units has intensified over the last few years. Hence, examples of the design and application of these new units will be provided. PMID:26341597

  18. The effect of gait on swimming in viscoelastic fluids

    CERN Document Server

    Elfring, Gwynn J

    2015-01-01

    In this paper, we give formulas for the swimming of simplified two-dimensional bodies in complex fluids using the reciprocal theorem. By way of these formulas we calculate the swimming velocity due to small-amplitude deformations on the simplest of these bodies, a two-dimensional sheet, to explore general conditions on the swimming gait under which the sheet may move faster, or slower, in a viscoelastic fluid compared to a Newtonian fluid.

  19. Gyroelastic fluids

    Energy Technology Data Exchange (ETDEWEB)

    Kerbel, G.D.

    1981-01-20

    A study is made of a scale model in three dimensions of a guiding center plasma within the purview of gyroelastic (also known as finite gyroradius-near theta pinch) magnetohydrodynamics. The (nonlinear) system sustains a particular symmetry called isorrhopy which permits the decoupling of fluid modes from drift modes. Isorrhopic equilibria are analyzed within the framework of geometrical optics resulting in (local) dispersion relations and ray constants. A general scheme is developed to evolve an arbitrary linear perturbation of a screwpinch equilibrium as an invertible integral transform (over the complete set of generalized eigenfunctions defined naturally by the equilibrium). Details of the structure of the function space and the associated spectra are elucidated. Features of the (global) dispersion relation owing to the presence of gyroelastic stabilization are revealed. An energy principle is developed to study the stability of the tubular screwpinch.

  20. Gyroelastic fluids

    International Nuclear Information System (INIS)

    A study is made of a scale model in three dimensions of a guiding center plasma within the purview of gyroelastic (also known as finite gyroradius-near theta pinch) magnetohydrodynamics. The (nonlinear) system sustains a particular symmetry called isorrhopy which permits the decoupling of fluid modes from drift modes. Isorrhopic equilibria are analyzed within the framework of geometrical optics resulting in (local) dispersion relations and ray constants. A general scheme is developed to evolve an arbitrary linear perturbation of a screwpinch equilibrium as an invertible integral transform (over the complete set of generalized eigenfunctions defined naturally by the equilibrium). Details of the structure of the function space and the associated spectra are elucidated. Features of the (global) dispersion relation owing to the presence of gyroelastic stabilization are revealed. An energy principle is developed to study the stability of the tubular screwpinch

  1. Meniscal Tear Film Fluid Dynamics Near Marx’s Line

    KAUST Repository

    Zubkov, V. S.

    2013-07-03

    Extensive studies have explored the dynamics of the ocular surface fluid, though theoretical investigations are typically limited to the use of the lubrication approximation, which is not guaranteed to be uniformly valid a-priori throughout the tear meniscus. However, resolving tear film behaviour within the meniscus and especially its apices is required to characterise the flow dynamics where the tear film is especially thin, and thus most susceptible to evaporatively induced hyperosmolarity and subsequent epithelial damage. Hence, we have explored the accuracy of the standard lubrication approximation for the tear film by explicit comparisons with the 2D Navier-Stokes model, considering both stationary and moving eyelids. Our results demonstrate that the lubrication model is qualitatively accurate except in the vicinity of the eyelids. In particular, and in contrast to lubrication theory, the solution of the full Navier-Stokes equations predict a distinct absence of fluid flow, and thus convective mixing in the region adjacent to the tear film contact line. These observations not only support emergent hypotheses concerning the formation of Marx\\'s line, a region of epithelial cell staining adjacent to the contact line on the eyelid, but also enhance our understanding of the pathophysiological consequences of the flow profile near the tear film contact line. © 2013 Society for Mathematical Biology.

  2. NUMERICAL SIMULATION OF A TWO-DIMENSIONAL SQUARE MOVING NEAR FREE SURFACE

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The body moving near the free surface is a focus in fluid dynamicresearch. Many numerical methods were developed for the simulation of the induced flow field. In this paper, a two-dimensional square moving near the free surface was simulated by the volume of fluid method (VOF). The flow field and drag exerted on the square were studied. The drag would increase due to the presence of the free surface.The iteration factor of the pressure interpolation of surface cells was modified, and through this modification the iteration became more stable. The capability of dealing with the large deformation of the free surface was raised.

  3. Quantifying electron transfer reactions in biological systems

    DEFF Research Database (Denmark)

    Sjulstok, Emil Sjulstok; Olsen, Jógvan Magnus Haugaard; Solov'yov, Ilia A

    2015-01-01

    Various biological processes involve the conversion of energy into forms that are usable for chemical transformations and are quantum mechanical in nature. Such processes involve light absorption, excited electronic states formation, excitation energy transfer, electrons and protons tunnelling...... quantum physics and biology. In this paper we consider electron transfer in biological processes, from a theoretical view-point; namely in terms of quantum mechanical and semi-classical models. We systematically characterize the interactions between the moving electron and its biological environment to...

  4. Dark matter. A light move

    Energy Technology Data Exchange (ETDEWEB)

    Redondo, Javier [Muenchen Univ. (Germany). Arnold Sommerfeld Center; Max-Planck-Institut fuer Physik, Muenchen (Germany); Doebrich, Babette [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2013-11-15

    This proceedings contribution reports from the workshop Dark Matter - a light move, held at DESY in Hamburg in June 2013. Dark Matter particle candidates span a huge parameter range. In particular, well motivated candidates exist also in the sub-eV mass region, for example the axion. Whilst a plethora of searches for rather heavy Dark Matter particles exists, there are only very few experiments aimed at direct detection of sub-eV Dark Matter to this date. The aim of our workshop was to discuss if and how this could be changed in the near future.

  5. Moving Walkways, Escalators, and Elevators

    CERN Document Server

    Cardinal, J; Hurtado, F; Langerman, S; Palop, B

    2007-01-01

    We study a simple geometric model of transportation facility that consists of two points between which the travel speed is high. This elementary definition can model shuttle services, tunnels, bridges, teleportation devices, escalators or moving walkways. The travel time between a pair of points is defined as a time distance, in such a way that a customer uses the transportation facility only if it is helpful. We give algorithms for finding the optimal location of such a transportation facility, where optimality is defined with respect to the maximum travel time between two points in a given set.

  6. Numerical Simulation of Wave Interaction with Moving Net Structures

    DEFF Research Database (Denmark)

    Chen, Hao; Christensen, Erik Damgaard

    2015-01-01

    Fluid structure interaction is an important issue in designof many engineering systems including offshore fish cages. As a first step to develop a coupled CFD/FEM model, in the present study a moving porous media model has been developed in the open source library Open FOAM. The net structure was...... described as a sheet of porous media with prescribed rigid body motion and mesh motion was incorporated to conform the motion of the net. Free surface wave generation and absorption framework was also introduced to simulate wave interaction with moving net structures. The results showed that mesh motion...... solver was coupled with free surface wave generation and absorption framework and porous media model flawlessly, and the deformed mesh remained acceptable. It was concluded that Laplace mesh motionsolver with inversed quadratic diffusivity model was an appropriate option for simulating wave interaction...

  7. Moving least-squares corrections for smoothed particle hydrodynamics

    Directory of Open Access Journals (Sweden)

    Ciro Del Negro

    2011-12-01

    Full Text Available First-order moving least-squares are typically used in conjunction with smoothed particle hydrodynamics in the form of post-processing filters for density fields, to smooth out noise that develops in most applications of smoothed particle hydrodynamics. We show how an approach based on higher-order moving least-squares can be used to correct some of the main limitations in gradient and second-order derivative computation in classic smoothed particle hydrodynamics formulations. With a small increase in computational cost, we manage to achieve smooth density distributions without the need for post-processing and with higher accuracy in the computation of the viscous term of the Navier–Stokes equations, thereby reducing the formation of spurious shockwaves or other streaming effects in the evolution of fluid flow. Numerical tests on a classic two-dimensional dam-break problem confirm the improvement of the new approach.

  8. Renormalization group theory for fluids

    International Nuclear Information System (INIS)

    Some extensions of renormalization group methods to fluids are discussed that may facilitate the development of a general renormalization group theory for real fluids that is capable of predicting their thermodynamic properties globally, including both at the critical point and away from the critical point, from a specification solely of the microscopic interactions among the constituent molecules. The extensions include application to virial series and free energies for freely moving molecules (as contrasted with Hamiltonian methods used for fixed lattices of molecules); inclusion of contributions from fluctuations of very short wavelengths, comparable to the range of the attractive forces; and evaluation of the scale factor for fluctuation amplitudes. An approximate theory incorporating these new features is formulated and illustrated in a simple application to the thermal behavior of n-pentane in a large extended neighborhood of its critical point

  9. Autonomous Landing on Moving Platforms

    KAUST Repository

    Mendoza Chavez, Gilberto

    2016-08-01

    This thesis investigates autonomous landing of a micro air vehicle (MAV) on a nonstationary ground platform. Unmanned aerial vehicles (UAVs) and micro air vehicles (MAVs) are becoming every day more ubiquitous. Nonetheless, many applications still require specialized human pilots or supervisors. Current research is focusing on augmenting the scope of tasks that these vehicles are able to accomplish autonomously. Precise autonomous landing on moving platforms is essential for self-deployment and recovery of MAVs, but it remains a challenging task for both autonomous and piloted vehicles. Model Predictive Control (MPC) is a widely used and effective scheme to control constrained systems. One of its variants, output-feedback tube-based MPC, ensures robust stability for systems with bounded disturbances under system state reconstruction. This thesis proposes a MAV control strategy based on this variant of MPC to perform rapid and precise autonomous landing on moving targets whose nominal (uncommitted) trajectory and velocity are slowly varying. The proposed approach is demonstrated on an experimental setup.

  10. Globin genes on the move

    OpenAIRE

    Hardison, Ross C.

    2008-01-01

    Recent data published in BMC Biology from the globin gene clusters in platypus, together with data from other species, show that β-globin genes transposed from one chromosomal location to another. This resolves some controversies about vertebrate globin gene evolution but ignites new ones.

  11. Senior Living: Staying Positive and Moving Forward

    Science.gov (United States)

    ... Issues Feature: Senior Living Staying Positive and Moving Forward Past Issues / Summer 2009 Table of Contents For ... Living / Long Distance Caregiving / Staying Positive and Moving Forward / Former WWII Fighter Pilot Finds New Home Near ...

  12. 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.

  13. Fluid-driven deformation of a soft granular material

    OpenAIRE

    MacMinn, Christopher W.; Dufresne, Eric R.; Wettlaufer, John S.

    2014-01-01

    Compressing a porous, fluid-filled material will drive the interstitial fluid out of the pore space, as when squeezing water out of a kitchen sponge. Inversely, injecting fluid into a porous material can deform the solid structure, as when fracturing a shale for natural gas recovery. These poromechanical interactions play an important role in geological and biological systems across a wide range of scales, from the propagation of magma through the Earth's mantle to the transport of fluid thro...

  14. GAIA: A 2-D Curvilinear moving grid hydrodynamic code

    International Nuclear Information System (INIS)

    The GAIA computer code is developed for time dependent, compressible, multimaterial fluid flow problems, to overcome some drawbacks of traditional 2-D Lagrangian codes. The initial goals of robustness, entropy accuracies, efficiency in presence of large interfacial slip, have already been achieved. The general GODUNOV approach is applied to an arbitrary time varying control-volume formulation. We review in this paper the Riemann solver, the GODUNOV cartesian and curvilinear moving grid schemes and an efficient grid generation algorithm. We finally outline a possible second order accuracy extension

  15. Co-Optimization of Blunt Body Shapes for Moving Vehicles

    Science.gov (United States)

    Brown, James L. (Inventor); Garcia, Joseph A (Inventor); Kinney, David J. (Inventor); Bowles, Jeffrey V (Inventor); Mansour, Nagi N (Inventor)

    2014-01-01

    A method and associated system for multi-disciplinary optimization of various parameters associated with a space vehicle that experiences aerocapture and atmospheric entry in a specified atmosphere. In one embodiment, simultaneous maximization of a ratio of landed payload to vehicle atmospheric entry mass, maximization of fluid flow distance before flow separation from vehicle, and minimization of heat transfer to the vehicle are performed with respect to vehicle surface geometric parameters, and aerostructure and aerothermal vehicle response for the vehicle moving along a specified trajectory. A Pareto Optimal set of superior performance parameters is identified.

  16. Amodal completion of moving objects by pigeons

    OpenAIRE

    Nagasaka, Yasuo; Wasserman, Edward A.

    2008-01-01

    In a series of four experiments, we explored whether pigeons complete partially occluded moving shapes. Four pigeons were trained to discriminate between a complete moving shape and an incomplete moving shape in a two-alternative forced-choice task. In testing, the birds were presented with a partially occluded moving shape. In Experiment 1, none of the pigeons appeared to complete the testing stimulus; instead, they appeared to perceive the testing stimulus as incomplete fragments. However, ...

  17. Joint fluid Gram stain

    Science.gov (United States)

    Gram stain of joint fluid ... A sample of joint fluid is needed. The fluid sample is sent to a lab where a small drop is placed in a ... on how to prepare for the removal of joint fluid, see joint fluid aspiration .

  18. Magnetized drive fluids

    Energy Technology Data Exchange (ETDEWEB)

    Rosensweig, R.E.; Zahn, M.

    1986-04-01

    A process is described for recovering a first fluid from a porous subterranean formation which comprises injecting a displacement fluid in an effective amount to displace the first fluid, injecting a ferrofluid, applying a magnetic field containing a gradient of field intensity within the formation, driving the displacement fluid through the formation with the ferrofluid and recovering first fluid.

  19. CIRCULATING MOVING BED COMBUSTION PROOF OF CONCEPT

    Energy Technology Data Exchange (ETDEWEB)

    Jukkola, Glen

    2010-06-30

    Circulating Moving Bed (CMB) combustion technology has its roots in traditional circulating fluidized bed technology and involves a novel method of solid fuel combustion and heat transfer. CMB technology represents a step change in improved performance and cost relative to conventional PC and FBC boilers. The CMB heat exchanger preheats the energy cycle working fluid, steam or air, to the high temperature levels required in systems for advanced power generation. Unique features of the CMB are the reduction of the heat transfer surfaces by about 60% as a result of the enhanced heat transfer rates, flexibility of operation, and about 30% lower cost over existing technology. The CMB Phase I project ran from July 2001 through March 2003. Its objective was to continue development of the CMB technology with a series of proof of concept tests. The tests were conducted at a scale that provided design data for scale up to a demonstration plant. These objectives were met by conducting a series of experiments in ALSTOM Power’s Multi-use Test Facility (MTF). The MTF was modified to operate under CMB conditions of commercial interest. The objective of the tests were to evaluate gas-to-solids heat transfer in the upper furnace, assess agglomeration in the high temperature CMB bubbling bed, and evaluate solids-to-tube heat transfer in the moving bed heat exchanger. The Phase I program results showed that there are still some significant technical uncertainties that needed to be resolved before the technology can be confidently scaled up for a successful demonstration plant design. Work remained in three primary areas: • scale up of gas to solid heat transfer • high temperature finned surface design • the overall requirements of mechanical and process design. The CMB Phase II workscope built upon the results of Phase I and specifically addressed the remaining technical uncertainties. It included a scaled MTF heat transfer test to provide the necessary data to scale up gas

  20. Rolling motion in moving droplets

    Indian Academy of Sciences (India)

    Sumesh P Thampi; Rama Govindarajan

    2015-03-01

    Drops moving on a substrate under the action of gravity display both rolling and sliding motions. The two limits of a thin sheet-like drop in sliding motion on a surface, and a spherical drop in roll, have been extensively studied. We are interested in intermediate shapes. We quantify the contribution of rolling motion for any intermediate shape, and recently obtained a universal curve for the amount of roll as a function of a shape parameter using hybrid lattice Boltzmann simulations. In this paper, we discuss the linear relationship which is expected between the Capillary and Bond numbers, and provide detailed confirmation by simulations. We also show that the viscosity of the surrounding medium can qualitatively affect dynamics. Our results provide an answer to a natural question of whether drops roll or slide on a surface and carry implications for various applications where rolling motion may or may not be preferred.

  1. Moving Horizon Estimation and Control

    DEFF Research Database (Denmark)

    Jørgensen, John Bagterp

    successful and applied methodology beyond PID-control for control of industrial processes. The main contribution of this thesis is introduction and definition of the extended linear quadratic optimal control problem for solution of numerical problems arising in moving horizon estimation and control. An...... extended linear quadratic control problem is the key contribution of this thesis. In addition chapter 1 provides a comprehensive survey of existing methods for model predictive control. Chapter 2 discusses computational methods and inherent approximations in model predictive control. By considering the....... Appendix A demonstrates how quadratic programs arise in sequential quadratic programming algorithms. Appendix B uses a control vector parameterization approach to express various extended constrained linear quadratic optimal control problems as standard quadratic programs. Appendix C discuss construction...

  2. Prototype moving-ring reactor

    International Nuclear Information System (INIS)

    We have completed a design of the Prototype Moving-Ring Reactor. The fusion fuel is confined in current-carrying rings of magnetically-field-reversed plasma (Compact Toroids). The plasma rings, formed by a coaxial plasma gun, undergo adiabatic magnetic compression to ignition temperature while they are being injected into the reactor's burner section. The cylindrical burner chamber is divided into three burn stations. Separator coils and a slight axial guide field gradient are used to shuttle the ignited toroids rapidly from one burn station to the next, pausing for 1/3 of the total burn time at each station. D-T-3He ice pellets refuel the rings at a rate which maintains constant radiated power

  3. Synovial fluid analysis

    Science.gov (United States)

    Joint fluid analysis; Joint fluid aspiration ... El-Gabalawy HS. Synovial fluid analysis, synovial biopsy, and synovial pathology. In: Firestein GS, Budd RC, Gabriel SE, McInnes IB, O'Dell JR, eds. Kelly's Textbook of ...

  4. Superconfinement tailors fluid flow at microscales.

    KAUST Repository

    Setu, Siti Aminah

    2015-06-15

    Understanding fluid dynamics under extreme confinement, where device and intrinsic fluid length scales become comparable, is essential to successfully develop the coming generations of fluidic devices. Here we report measurements of advancing fluid fronts in such a regime, which we dub superconfinement. We find that the strong coupling between contact-line friction and geometric confinement gives rise to a new stability regime where the maximum speed for a stable moving front exhibits a distinctive response to changes in the bounding geometry. Unstable fronts develop into drop-emitting jets controlled by thermal fluctuations. Numerical simulations reveal that the dynamics in superconfined systems is dominated by interfacial forces. Henceforth, we present a theory that quantifies our experiments in terms of the relevant interfacial length scale, which in our system is the intrinsic contact-line slip length. Our findings show that length-scale overlap can be used as a new fluid-control mechanism in strongly confined systems.

  5. Self lubricating fluid bearings

    International Nuclear Information System (INIS)

    The invention concerns self lubricating fluid bearings, which are used in a shaft sealed system extending two regions. These regions contain fluids, which have to be isolated. A first seal is fluid tight for the first region between the carter shaft and the shaft. The second seal is fluid tight between the carter and the shaft, it communicates with the second region. The first fluid region is the environment surrounding the shaft carter. The second fluid region is a part of a nuclear reactor which contains the cooling fluid. The shaft is conceived to drive a reactor circulating and cooling fluid

  6. INTEGRATED SUPERCRITICAL FLUID EXTRACTION AND BIOPROCESSING

    OpenAIRE

    Owen Catchpole; Stephen Tallon; Peter Dyer; Fernando Montanes; Teresa Moreno; Erika Vagi; Wayne Eltringham; Jagan Billakanti

    2012-01-01

    Supercritical fluids are increasingly being used and promoted at a laboratory and pilot scale to produce high value, natural bioactives from biologically based raw materials. Supercritical CO2 is overwhelmingly the solvent of choice for these operations, but is largely limited to the processing of dry raw materials and the extraction of low polarity, low molecular weight compounds. The use of co-solvents and the use of alternative ânear-criticalâ extraction fluids such as dimethyl ether show ...

  7. Numerical investigation of vortex ring formation through a moving valve

    Science.gov (United States)

    Farrar, Lucas; Zheng, Xudong; Xue, Qian

    2014-11-01

    Impulsively started, low-speed, incompressible jets observed in nature, are commonly found as starting flows through a moving valve. Similar flows are found the human heart where blood is transported from the left atrium, through the mitral valve, and into the left ventricle. During this process, a vortex is formed around the lip of the moving valve before propagating into the left ventricle. We use numerical simulations to investigate the vortex dynamics of starting flows through an axisymmetric nozzle with time varying exit geometry. Following the experimental work of Dabiri & Gharib (J. Fluid Mech. 538, 111, 2005), volumetric flow rate is held constant at the nozzle inlet, while the nozzle is treated as a rigid body with motion independent of fluid forces. We show that nozzle motion affects both vortex formation time and pinch-off time as well as the circulation and energy associated with the leading vortex ring. By parametrically ranging over a variety of prescribed flow rates and exit diameter frequencies, the independent contributions of the nozzle motion to the developing vortex structure are assessed.

  8. Method and apparatus for a combination moving bed thermal treatment reactor and moving bed filter

    Science.gov (United States)

    Badger, Phillip C.; Dunn, Jr., Kenneth J.

    2015-09-01

    A moving bed gasification/thermal treatment reactor includes a geometry in which moving bed reactor particles serve as both a moving bed filter and a heat carrier to provide thermal energy for thermal treatment reactions, such that the moving bed filter and the heat carrier are one and the same to remove solid particulates or droplets generated by thermal treatment processes or injected into the moving bed filter from other sources.

  9. Rheological flow from a die and painting on a moving solid wall

    Institute of Scientific and Technical Information of China (English)

    TANG; Zemei; HU; Wenrui

    2004-01-01

    Die swell is an important phenomenon in polymer processing, and is explained usually by rheological properties of the fluid. Because of the nonuniform of temperature distribution on the free surface of the liquid jet, the thermocapillary convection driven by surface tension gradient exists. The rheological fluid flowing out of a die and painting on a moving solid wall is studied by the numerical finite element method of a two-dimensional and unsteady model in the present paper, and both the rheological effect of a non-Newtonian fluid and the thermocapillary effect are considered. The results show that both effects will enlarge the cross-section of the fluid jet, and the rheological effect of non-Newtonian fluid dominates the process in general.

  10. The Telecom Lab is moving

    CERN Multimedia

    IT Department

    2009-01-01

    As of 2nd March 2009, the Telecom Lab will move to Building 58 R-017. The Telecom Lab is the central point for all support questions regarding CERN mobile phone services (provision of SIM cards, requests for modifications of subscriptions, diagnostics for mobile phone problems, etc.). The opening hours as well as the contact details for the Telecom Lab remain unchanged: New location: Building 58 R-017 Opening hours: Every week day, from 11 a.m. to 12 a.m. Phone number: 72480 Email address: labo.telecom@cern.ch This change has no impact on support requests for mobile services. Users can still submit their requests concerning mobile phone subscriptions using the usual EDH form (https://edh.cern.ch/Document/GSM). The automatic message sent to inform users of their SIM card availability will be updated to indicate the new Telecom Lab location. You can find all information related to CERN mobile phone services at the following link: http://cern.ch/gsm CS Section - IT/CS group

  11. Human follicular fluid adverses hamster spermatozoa motility.

    Science.gov (United States)

    Wetzels, A; Goverde, H J; Bastiaans, L A; Rolland, R

    1989-01-01

    To determine the optimal conditions for in vitro spermatozoa vitality, human and hamster spermatozoa were incubated at 37 degrees C in T6 medium supplemented with different biologic fluids (10% v/v). The fluids tested were human serum (HUS), hamster serum (HAS), and human follicular fluid (HUF). After incubation the spermatozoa were investigated for their qualitative and quantitative motility. Human spermatozoa maintained a good vitality in all fluids tested (approximately 25% motility after 18-h incubation). The hamster spermatozoa had after an incubation of 4 h a motility of 28.4% in HUS, 14.2% in HAS, and 2.2% in HUF. The quality of the motility was also extremely low in HUF, whereas it was adequate in HUS and in HAS. The presence of species-specific substances in mammalian follicular fluid is discussed. PMID:2589906

  12. Spontaneous oscillations in simple fluid networks

    CERN Document Server

    Karst, Nathaniel J; Geddes, John B

    2013-01-01

    Nonlinear phenomena including multiple equilibria and spontaneous oscillations are common in fluid networks containing either multiple phases or constituent flows. In many systems, such behavior might be attributed to the complicated geometry of the network, the complex rheology of the constituent fluids, or, in the case of microvascular blood flow, biological control. In this paper we investigate two examples of a simple three-node fluid network containing two miscible Newtonian fluids of differing viscosities, the first modeling microvascular blood flow and the second modeling stratified laminar flow. We use a combination of analytic and numerical techniques to identify and track saddle-node and Hopf bifurcations through the large parameter space. In both models, we document sustained spontaneous oscillations and, for an experimentally relevant example of parameter analysis, investigate the sensitivity of these oscillations to changes in the viscosity contrast between the constituent fluids and the inlet fl...

  13. Some moving boundary problems in underground energy processes

    Science.gov (United States)

    Zheng, Zhong

    In this thesis, we study four moving boundary problems motivated by underground energy processes such as enhancing oil recovery and geological CO2 sequestration. The major focus is the time evolution of the fluid-fluid interface under the effect of confinement, heterogeneity, drainage, and unfavorable viscosity ratio. Specifically, in Chapter 2, theoretical and numerical investigations are combined to study the effect of confinement when a fluid is injected into a porous medium saturated with another immiscible fluid. In the early time period, the effect of confinement is negligible, whereas the confinement effect becomes significant in the late time period. The flow behaviour is summarized in a regime diagram with five distinct dynamical regimes that characterize the shape of the interface: a nonlinear diffusion regime, a transition regime, a traveling wave regime, an equal viscosity regime, and a rarefaction wave regime. The thesis continues in Chapter 3 with a theoretical study based on a phase-plane analysis of the effect of horizontal heterogeneity, which eventually reveals the existence of a second-kind self-similar solution when a viscous gravity current is propagating toward the origin. Scaling arguments alone do not work in this case, because there exists a natural length scale, i.e., the distance between the origin and the initial location of the fluid, and hence a natural time scale, i.e., the time for the front to reach the origin. Experimental and numerical results are also provided to support the theoretical predictions. Our study on drainage, described in Chapter 4, provides a self-similar solution to describe the buoyancy-driven fluid drainage process. Previous reports mainly focus on the propagation problem when the information on the global mass is given. In contrast, in a fluid drainage process the time evolution of the global mass is obtained as the solution of the problem. The thesis closes in Chapter 5, with theoretical and experimental

  14. Interfacial gauge methods for incompressible fluid dynamics.

    Science.gov (United States)

    Saye, Robert

    2016-06-01

    Designing numerical methods for incompressible fluid flow involving moving interfaces, for example, in the computational modeling of bubble dynamics, swimming organisms, or surface waves, presents challenges due to the coupling of interfacial forces with incompressibility constraints. A class of methods, denoted interfacial gauge methods, is introduced for computing solutions to the corresponding incompressible Navier-Stokes equations. These methods use a type of "gauge freedom" to reduce the numerical coupling between fluid velocity, pressure, and interface position, allowing high-order accurate numerical methods to be developed more easily. Making use of an implicit mesh discontinuous Galerkin framework, developed in tandem with this work, high-order results are demonstrated, including surface tension dynamics in which fluid velocity, pressure, and interface geometry are computed with fourth-order spatial accuracy in the maximum norm. Applications are demonstrated with two-phase fluid flow displaying fine-scaled capillary wave dynamics, rigid body fluid-structure interaction, and a fluid-jet free surface flow problem exhibiting vortex shedding induced by a type of Plateau-Rayleigh instability. The developed methods can be generalized to other types of interfacial flow and facilitate precise computation of complex fluid interface phenomena. PMID:27386567

  15. Fluid Dynamics in an Ecological Context

    Science.gov (United States)

    Denny, Mark

    2007-11-01

    Fluid dynamics has long been an invaluable tool in the study of biological mechanics, helping to explain how animals swim and fly, how blood is pumped, gases are exchanged, and propagules are dispersed. The goal of understanding how the physics of fluids has affected the evolution of individual organisms provides strong impetus for teaching and learning fluid mechanics; a viable alternative to the more traditional goals of engineering. In recent years, a third alternative has arisen. The principles of fluid dynamics can be used to specify when and where individual organisms will exceed their physical capabilities, information that can in turn be used to predict species-specific survivorship in a given environment. In other words, biological fluid dynamics can be extended beyond the study of individual organisms to play an important role in our understanding of ecological dynamics. In a world where environmental change is of increasing concern, fluid dynamic aspect of ``ecomechanics'' may be of considerable practical importance. Teaching fluid mechanics in ecology will be discussed in the context of wave-swept rocky shores. Various wave theories can be used to predict the maximum water velocities and accelerations impinging on specific surf-zone plants and animals. Theories of lift, drag, and accelerational forces can then be used to predict the maximum loads imposed on these organisms, loads that can be compared to the organisms' structural limits to predict the fraction of the species that will be dislodged or damaged. Taken across relevant species, this information goes far towards explaining shoreline community dynamics. .

  16. Biology of Nanobots

    Science.gov (United States)

    Duan, Wentao; Pavlick, Ryan; Sen, Ayusman

    2013-12-01

    One of the more interesting recent discoveries has been the ability to design nano/microbots which catalytically harness the chemical energy in their environment to move autonomously. Their potential applications include delivery of materials, self-assembly of superstructures, and roving sensors. One emergent area of research is the study of their collective behavior and how they emulate living systems. The aim of this chapter is to describe the "biology" of nanobots, summarizing the fundamentals physics behind their motion and how the bots interact with each other to initiate complex emergent behavior.

  17. Imagine Moving Off the Planet

    Science.gov (United States)

    Elfrey, Priscilla R.

    2006-01-01

    Moving off the planet will be a defining moment of this century as landing on the Moon was in the last. For that to happen for humans to go where humans cannot go-- simulation is the sole solution. NASA supports simulation for life-cycle activities: design, analysis, test, checkout, operations, review and training. We contemplate time spans of a century and more, teams dispersed to different planets and the need for systems that endure or adapt as missions, teams and technology change. Without imagination such goals are impossible. But with imagination we can go outside our present perception of reality to think about and take action on what has been, is and, especially, what might be. Consciously maturing an imagined, possibly workable, idea through framing it to optimization to design, and building the product provides us with a new approach to innovation and simulation fidelity. We address options, analyze, test and make improvements in how we think and work. Each step includes increasingly exact information about costs, schedule, who will be needed, where, when and how. NASA i integrating such thinking into its Exploration Product Realization Hierarchy for simulation and analysis, test and verification, and stimulus response goals. Technically NASA follows a timeline of studies, analysis, definition, design, development and operations with concurrent documentation. We have matched this Product Realization Hierarchy with a continuum from image to realization that incorporates commitment, current and needed research and communication to ensure superior and creative problem solving as well as advances in simulation. One result is a new approach to collaborative systems. Another is a distributed observer network prototyped using game engine technology bringing advanced 3-D simulation of a simulation to the desktop enabling people to develop shared consensus of its meaning. Much of the value of simulation comes from developing in people their ability to make good

  18. Clustering for networks of moving objects

    OpenAIRE

    Rakocevic, V.

    2014-01-01

    This chapter presents the problem of clustering of moving objects in ad hoc wireless networks. The networks of moving objects include networks of flying objects, networks of cars and other vehicles, networks of people moving in the cities, and networks of robots sensing the environment or performing coordinated actions. Clustering of such objects increases the scalability of the network and improves efficiency, enabling the objects to simplify the communication with their peers. Clustering of...

  19. Apparent stress-strain relationships in experimental equipment where magnetorheological fluids operate under compression mode

    OpenAIRE

    Mazlan, SA; Ekreem, NB; Olabi, Abdul

    2008-01-01

    Abstract: This paper presents an experimental investigation of two different magnetorheological ( MR) fluids, namely, water-based and hydrocarbon-based MR fluids in compression mode under various applied currents. Finite element method magnetics was used to predict the magnetic field distribution inside the MR fluids generated by a coil. A test rig was constructed where the MR fluid was sandwiched between two flat surfaces. During the compression, the upper surface was moved towards the lower...

  20. Two non-comoving stiff fluids in radial motion and spherical symmetry

    OpenAIRE

    Kostov, Valentin

    2008-01-01

    The problem of two stiff fluids (energy density = pressure) moving radially in spherical symmetry is treated. The metric ansatz is chosen spherically symmetric, conformally static with a multiplicative separation of variables. The first fluid is described mathematically via a massless scalar field. The coordinate system is chosen comoving with the second fluid which the separation of variables requires to be stiff too. The fluids are interacting only gravitationally and their energy momentum ...

  1. Magnetic Fluids: Biomedical Applications and Magnetic Fractionation

    OpenAIRE

    Rheinländer, Thomas; Kötitz, Róman; Weitschies, Werner; Semmler, Wolfhard

    2000-01-01

    In addition to engineering applications, magnetic fluids containing magnetic nanoparticles are being increasingly applied to biomedical purposes. Besides the well established use of magnetic particles for biological separation or as contrast agents for magnetic resonance imaging, magnetic particles are also being tested for the inductive heat treatment of tumors or as markers for the quantification of biologically active substances. The properties of magnetic nanoparticles usually exhibit a b...

  2. Diet and asthma: looking back, moving forward.

    Science.gov (United States)

    Kim, June-Ho; Ellwood, Philippa E; Asher, M Innes

    2009-01-01

    Asthma is an increasing global health burden, especially in the western world. Public health interventions are sought to lessen its prevalence or severity, and diet and nutrition have been identified as potential factors. With rapid changes in diet being one of the hallmarks of westernization, nutrition may play a key role in affecting the complex genetics and developmental pathophysiology of asthma. The present review investigates hypotheses about hygiene, antioxidants, lipids and other nutrients, food types and dietary patterns, breastfeeding, probiotics and intestinal microbiota, vitamin D, maternal diet, and genetics. Early hypotheses analyzed population level trends and focused on major dietary factors such as antioxidants and lipids. More recently, larger dietary patterns beyond individual nutrients have been investigated such as obesity, fast foods, and the Mediterranean diet. Despite some promising hypotheses and findings, there has been no conclusive evidence about the role of specific nutrients, food types, or dietary patterns past early childhood on asthma prevalence. However, diet has been linked to the development of the fetus and child. Breastfeeding provides immunological protection when the infant's immune system is immature and a modest protective effect against wheeze in early childhood. Moreover, maternal diet may be a significant factor in the development of the fetal airway and immune system. As asthma is a complex disease of gene-environment interactions, maternal diet may play an epigenetic role in sensitizing fetal airways to respond abnormally to environmental insults. Recent hypotheses show promise in a biological approach in which the effects of dietary factors on individual physiology and immunology are analyzed before expansion into larger population studies. Thus, collaboration is required by various groups in studying this enigma from epidemiologists to geneticists to immunologists. It is now apparent that this multidisciplinary

  3. Diet and asthma: looking back, moving forward

    Directory of Open Access Journals (Sweden)

    Ellwood Philippa E

    2009-06-01

    Full Text Available Abstract Asthma is an increasing global health burden, especially in the western world. Public health interventions are sought to lessen its prevalence or severity, and diet and nutrition have been identified as potential factors. With rapid changes in diet being one of the hallmarks of westernization, nutrition may play a key role in affecting the complex genetics and developmental pathophysiology of asthma. The present review investigates hypotheses about hygiene, antioxidants, lipids and other nutrients, food types and dietary patterns, breastfeeding, probiotics and intestinal microbiota, vitamin D, maternal diet, and genetics. Early hypotheses analyzed population level trends and focused on major dietary factors such as antioxidants and lipids. More recently, larger dietary patterns beyond individual nutrients have been investigated such as obesity, fast foods, and the Mediterranean diet. Despite some promising hypotheses and findings, there has been no conclusive evidence about the role of specific nutrients, food types, or dietary patterns past early childhood on asthma prevalence. However, diet has been linked to the development of the fetus and child. Breastfeeding provides immunological protection when the infant's immune system is immature and a modest protective effect against wheeze in early childhood. Moreover, maternal diet may be a significant factor in the development of the fetal airway and immune system. As asthma is a complex disease of gene-environment interactions, maternal diet may play an epigenetic role in sensitizing fetal airways to respond abnormally to environmental insults. Recent hypotheses show promise in a biological approach in which the effects of dietary factors on individual physiology and immunology are analyzed before expansion into larger population studies. Thus, collaboration is required by various groups in studying this enigma from epidemiologists to geneticists to immunologists. It is now apparent that

  4. Droplet motion in one-component fluids on solid substrates with wettability gradients.

    Science.gov (United States)

    Xu, Xinpeng; Qian, Tiezheng

    2012-05-01

    Droplet motion on solid substrates has been widely studied not only because of its importance in fundamental research but also because of its promising potentials in droplet-based devices developed for various applications in chemistry, biology, and industry. In this paper, we investigate the motion of an evaporating droplet in one-component fluids on a solid substrate with a wettability gradient. As is well known, there are two major difficulties in the continuum description of fluid flows and heat fluxes near the contact line of droplets on solid substrates, namely, the hydrodynamic (stress) singularity and thermal singularity. To model the droplet motion, we use the dynamic van der Waals theory [Phys. Rev. E 75, 036304 (2007)] for the hydrodynamic equations in the bulk region, supplemented with the boundary conditions at the fluid-solid interface. In this continuum hydrodynamic model, various physical processes involved in the droplet motion can be taken into account simultaneously, e.g., phase transitions (evaporation or condensation), capillary flows, fluid velocity slip, and substrate cooling or heating. Due to the use of the phase field method (diffuse interface method), the hydrodynamic and thermal singularities are resolved automatically. Furthermore, in the dynamic van der Waals theory, the evaporation or condensation rate at the liquid-gas interface is an outcome of the calculation rather than a prerequisite as in most of the other models proposed for evaporating droplets. Numerical results show that the droplet migrates in the direction of increasing wettability on the solid substrates. The migration velocity of the droplet is found to be proportional to the wettability gradients as predicted by Brochard [Langmuir 5, 432 (1989)]. The proportionality coefficient is found to be linearly dependent on the ratio of slip length to initial droplet radius. These results indicate that the steady migration of the droplets results from the balance between the

  5. Droplet motion in one-component fluids on solid substrates with wettability gradients

    KAUST Repository

    Xu, Xinpeng

    2012-05-11

    Droplet motion on solid substrates has been widely studied not only because of its importance in fundamental research but also because of its promising potentials in droplet-based devices developed for various applications in chemistry, biology, and industry. In this paper, we investigate the motion of an evaporating droplet in one-component fluids on a solid substrate with a wettability gradient. As is well known, there are two major difficulties in the continuum description of fluid flows and heat fluxes near the contact line of droplets on solid substrates, namely, the hydrodynamic (stress) singularity and thermal singularity. To model the droplet motion, we use the dynamic van der Waals theory [Phys. Rev. E 75, 036304 (2007)] for the hydrodynamic equations in the bulk region, supplemented with the boundary conditions at the fluid-solid interface. In this continuum hydrodynamic model, various physical processes involved in the droplet motion can be taken into account simultaneously, e.g., phase transitions (evaporation or condensation), capillary flows, fluid velocity slip, and substrate cooling or heating. Due to the use of the phase field method (diffuse interface method), the hydrodynamic and thermal singularities are resolved automatically. Furthermore, in the dynamic van der Waals theory, the evaporation or condensation rate at the liquid-gas interface is an outcome of the calculation rather than a prerequisite as in most of the other models proposed for evaporating droplets. Numerical results show that the droplet migrates in the direction of increasing wettability on the solid substrates. The migration velocity of the droplet is found to be proportional to the wettability gradients as predicted by Brochard [Langmuir 5, 432 (1989)]. The proportionality coefficient is found to be linearly dependent on the ratio of slip length to initial droplet radius. These results indicate that the steady migration of the droplets results from the balance between the

  6. Fundamentals of Geophysical Fluid Dynamics

    Science.gov (United States)

    McWilliams, James C.

    2006-07-01

    Earth's atmosphere and oceans exhibit complex patterns of fluid motion over a vast range of space and time scales. These patterns combine to establish the climate in response to solar radiation that is inhomogeneously absorbed by the materials comprising air, water, and land. Spontaneous, energetic variability arises from instabilities in the planetary-scale circulations, appearing in many different forms such as waves, jets, vortices, boundary layers, and turbulence. Geophysical fluid dynamics (GFD) is the science of all these types of fluid motion. This textbook is a concise and accessible introduction to GFD for intermediate to advanced students of the physics, chemistry, and/or biology of Earth's fluid environment. The book was developed from the author's many years of teaching a first-year graduate course at the University of California, Los Angeles. Readers are expected to be familiar with physics and mathematics at the level of general dynamics (mechanics) and partial differential equations. Covers the essential GFD required for atmospheric science and oceanography courses Mathematically rigorous, concise coverage of basic theory and applications to both oceans and atmospheres Author is a world expert; this book is based on the course he has taught for many years Exercises are included, with solutions available to instructors from solutions@cambridge.org

  7. 人羊水干细胞分离方法及其生物学特性研究%Isolation and Biological Characterization of Human Amniotic Fluid-derived Stem Cells

    Institute of Scientific and Technical Information of China (English)

    关婷; 谢晓砚; 刘珊玲; 陈新莲; 魏杨君; 赖怡; 谢良玉; 刘之英; 张雪梅; 刘洪倩; 张建军

    2012-01-01

    Objective To establish in vitro culture procedure for human amniotic fluid-derived CD117 positive stem cells, and to identify the characteristics of CD117 positive stem cells. Methods 86 amniotic fluid samples (10 mL of each) were obtained by second-trimester amniocentesis. Isolation of amniotic fluid-derived stem cells expressing CD117 antigen was performed via magnetic cell sorting using the CD117 MicroBead Kit. The karyotype of CD117 positive stem cells was analysed throughrepeated freezing. Adipogenic differentiation of these CD117 positive stem cells was displayed by Oil Red O staining. Osteogeneic differentiation of these CD117 positive stem cells was confirmed by Alizarin Red staining. Results The CD117 positive stem cells were successfully isolated and cultured from 61 samples, with all showing normal karyotype. Product analysis of specific staining confirmed that under specific culture mediums, these cells could be successfully induced to differentiate into adipocytes and osteocytes. Conclusion Based on this study, we estimate that isolating CD117 positive stem cells from second-trimester amniotic fluid obtained by amniocentesis has a success rate of 70. 93%. These cells maintain morphological and genetic stability in vitro. Human amniotic fluid-derived CD117 positive stem cells have the ability to differentiate in vitro into adipocytes and osteocytes under specific cuLture mediums and may be applied in cell transplantation and regenerative medicine.%目的 建立体外培养人羊水来源CD117阳性干细胞的方法,初步探讨CD117阳性干细胞的特性.方法 通过孕中期羊膜腔穿刺获得86例羊水标本.采用CD117磁珠分选表达CD117抗原的羊水干细胞.对经过反复冻存的CD117阳性干细胞进行核型分析.分别经成脂诱导和成骨诱导分化,再分别使用油红O染色、茜素红染色.结果 从61例标本中成功分离培养出CD117阳性细胞,经核型分析显示其染色体核型正常.CD117阳性细胞经

  8. Direct numerical simulation of complex multi-fluid flows using a combined immersed boundary (IB) and volume of fluid (VOF) approach

    NARCIS (Netherlands)

    Deen, Niels G.; Sint Annaland, van Martin; Kuipers, J.A.M.

    2006-01-01

    In this paper a simulation model is presented for the Direct Numerical Simulation (DNS) of complex multi-fluid flows in which simultaneously (moving) deformable (drops or bubbles) and non-deformable (moving) elements (particles) are present, possibly with the additional presence of free surfaces. Ou

  9. Understanding the Mechanisms Enabling an Ultra-high Efficiency Moving Wire Interface for Real-time Carbon 14 Accelerator Mass Spectrometry Quantitation of Samples Suspended in Solvent

    Science.gov (United States)

    Thomas, Avraham Thaler

    Carbon 14 (14C) quantitation by accelerator mass spectrometry (AMS) is a powerfully sensitive and uniquely quantitative tool for tracking labeled carbonaceous molecules in biological systems. This is due to 14C's low natural abundance of 1 ppt, the nominal difference in biological activity between an unlabeled and a 14C-labeled molecule, and the ability of AMS to measure isotopic ratios independently of a sample's other characteristics. To make AMS more broadly accessible, a moving wire interface for real-time coupling of high pressure liquid chromatography (HPLC) to AMS and high throughput AMS quantitation of minute single samples has been developed. Prior to this work, samples needed to be converted to solid carbon before measurement. This conversion process has many steps and requires that the sample size be large enough to allow precise handling of the resulting graphite. These factors make the process susceptible to error and time consuming, as well as requiring 0.5 ug of carbon. Samples which do not contain enough carbon, such as HPLC fractions, must be bulked up. This adds background and increases effort. The moving wire interface overcomes these limitations by automating sample processing. Samples placed on the wire are transported through a solvent removal stage followed by a combustion stage after which the combustion products are directed to a gas accepting ion source. The ion source converts the carbon from the CO2 combustion product into C ions, from which an isotopic ratio can be determined by AMS. Although moving wire interfaces have been implemented for various tasks since 1964, the efficiency of these systems at transferring fluid from an HPLC to the wire was only 3%, the efficiency of transferring combustion products from the combustion oven to ion source was only 30%, the flow and composition of the carrier gas from the combustion oven to the ion source needed to be optimized for coupling to an AMS gas accepting ion source and the drying ovens

  10. Stick-Slip Motion of Moving Contact Line on Chemically Patterned Surfaces

    KAUST Repository

    Wu, Congmin

    2009-01-01

    Based on our continuum hydrodynamic model for immiscible two-phase flows at solid surfaces, the stick-slip motion has been predicted for moving contact line at chemically patterned surfaces [Wang et al., J. Fluid Mech., 605 (2008), pp. 59-78]. In this paper we show that the continuum predictions can be quantitatively verified by molecular dynamics (MD) simulations. Our MD simulations are carried out for two immiscible Lennard-Jones fluids confined by two planar solid walls in Poiseuille flow geometry. In particular, one solid surface is chemically patterned with alternating stripes. For comparison, the continuum model is numerically solved using material parameters directly measured in MD simulations. From oscillatory fluid-fluid interface to intermittent stick-slip motion of moving contact line, we have quantitative agreement between the continuum and MD results. This agreement is attributed to the accurate description down to molecular scale by the generalized Navier boundary condition in our continuum model. Numerical results are also presented for the relaxational dynamics of fluid-fluid interface, in agreement with a theoretical analysis based on the Onsager principle of minimum energy dissipation. © 2010 Global-Science Press.

  11. Novel Simulated moving bed technologies

    Energy Technology Data Exchange (ETDEWEB)

    Purdue University

    2003-12-30

    Cellulose and hemicellulose from plants and other biomass can be hydrolyzed to produce sugars (i.e. glucose and xylose). Once these sugars are separated from other impurities, they can serve as feedstock in fermentation to produce ethanol (as fuels), lactic acid, or other valuable chemicals. The need for producing fuels and chemicals from renewable biomass has become abundantly clear over the last decade. However, the cost of producing fermentable sugars from biomass hydrolyzate using existing technology is relatively high and has been a major obstacle. The objective of this project is to develop an efficient and economical simulated moving bed (SMB) process to recover fermentable sugars from biomass hydrolyzate. Sulfuric acid can hydrolyze the cellulose and hemicellulose in biomass to sugars, but this process can generate byproducts such as acetic acid, and can lead to further degradation of the xylose to furfural and glucose to hydroxymethyl furfural (HMF). Also, lignin and other compounds in the biomass will degrade to various phenolic compounds. If the concentrations of these compounds exceed certain threshold levels, they will be toxic to the downstream fermentation, and will severely limit the usefulness of the derived sugars. Standard post-hydrolysis processing involves neutralization of sulfuric acid, usually with lime (calcium hydroxide). A study by Wooley et al.showed that the limed hydrolyzate gave a low ethanol yield in fermentation test (20% of theoretical yield compared to 77% of theoretical yield from fermentation of pure sugars). They showed that instead of adding lime, an ion exclusion chromatography process could be used to remove acids, as well as to isolate the sugars from the biomass hydrolyzate. In this project, we investigated the feasibility of developing an economical SMB process based on (1) a polymeric adsorbent, Dowex99, which was used by Wooley et al., (2) a second polymeric adsorbent, poly-4-vinyl pyridine (or PVP in short, Reilly

  12. Effect of variable viscosity on laminar convection flow of an electrically conducting fluid in uniform magnetic field

    OpenAIRE

    Chakraborty S; Borkakati A.K.

    2002-01-01

    The flow of a viscous incompressible electrically conducting fluid on a continuous moving flat plate in presence of uniform transverse magnetic field, is studied. The flat plate which is continuously moving in its own plane with a constant speed is considered to be isothermally heated. Assuming the fluid viscosity as an inverse linear function of temperature, the nature of fluid velocity and temperature in presence of uniform magnetic field are shown for changing viscosity parameter at differ...

  13. Influência do tipo de material suporte no desempenho de reatores biológicos de leito móvel na remoção de carbono e nitrificação de esgoto sanitário The influence of material support kind on the biological moving bed reactors performance used for the carbon removal and nitrification of sewage

    Directory of Open Access Journals (Sweden)

    Delmira Beatriz Wolff

    2010-06-01

    Full Text Available Neste trabalho foi mostrada a influência do tipo de material suporte: P4 (plástico reciclado rugoso, diâmetro médio de 2,31 mm, densidade de 900 kg.m-3, superfície específica potencial de 2.596 m².m-3sup e P5 (polietileno, pouco rugoso, forma cilíndrica, diâmetro médio de 10 mm, densidade de 880 kg.m-3, superfície específica potencial de 3.075m².m-³sup utilizados em dois reatores biológicos de leito móvel, fluxo contínuo, na remoção de carbono e nitrificação de esgoto sanitário, os quais foram divididos em duas fases, de acordo com a idade do lodo (IL: fase A: IL de 10 dias e fase B: IL de 3 dias. Foram aplicadas cargas orgânicas superficiais médias de 4,0 kgDQO.m-2.d-1 (P4 e de 4,1 kgDQO.m-2.d-1 (P5; e cargas superficiais de nitrogênio de 0,63 kgN.m-2.d-1 (P5 e de 0,66 kgN.m-2.d-1 (P5. Para o material P4, a remoção média foi de 87% de carbono e 83% de nitrogênio (fase A e 80% de carbono e 77% de nitrogênio (fase B. Para o P5, remoção de 63% de carbono e 55% de nitrogênio (Fase A e 59% de carbono e de nitrogênio (fase B. Com base nos resultados obtidos, verificou-se que a remoção de carbono e nitrogênio não foi influenciada pela idade do lodo, mas pelo tipo de material suporte (forma ou características de superfície e superfície disponível para o crescimento da biomassa.This paper presented the influence of material support kind: P4 (rugous recycled plastic, medium diameter of 2.31 mm, density of 900 kg.m-3, specific surface potential of 2,596 m².m-3sup and P5 (polietilene, cilindric shape, medium diameter of 10 mm, density of 880 kg.m-3, specific surface potential of 3,075m².m-3sup used in two continuous flux biological moving bed reactors using different material support to remove nitrogen and carbon from sewage, which was divided in two phases according to sludge retention time (SRT: phase A: SRT of 10 days and phase B: SRT of 3 days. The organic loading rates applied were 4.0 kgCOD.m-2.d-1 (P4 and

  14. Theses "Discussion" Sections: A Structural Move Analysis

    Science.gov (United States)

    Nodoushan, Mohammad Ali Salmani; Khakbaz, Nafiseh

    2011-01-01

    The current study aimed at finding the probable differences between the move structure of Iranian MA graduates' thesis discussion subgenres and those of their non-Iranian counterparts, on the one hand, and those of journal paper authors, on the other. It also aimed at identifying the moves that are considered obligatory, conventional, or optional…

  15. Implementation of moving object tracking using EDK

    Directory of Open Access Journals (Sweden)

    Kota Solomon Raju

    2012-05-01

    Full Text Available The Xilinx Spartan family provides the ability to perform partial reconfiguration. This paper concentrates on how to track a moving object using three different components- fixed hardware, reconfigurable hardware and software. This flow can be considered to be a part of a general methodology to implement mean shift algorithm for tracking moving object.

  16. Implementation of moving object tracking using EDK

    OpenAIRE

    Kota Solomon Raju; Gargi Baruah; Manipati Rajesham; Palash Phukan; Manoj Pandey

    2012-01-01

    The Xilinx Spartan family provides the ability to perform partial reconfiguration. This paper concentrates on how to track a moving object using three different components- fixed hardware, reconfigurable hardware and software. This flow can be considered to be a part of a general methodology to implement mean shift algorithm for tracking moving object.

  17. Moving Target Photometry Using WISE and NEOWISE

    Science.gov (United States)

    Wright, Edward L.

    2015-01-01

    WISE band 1 observations have a significant noise contribution from confusion. The image subtraction done on W0855-0714 by Wright et al. (2014) shows that this noise source can be eliminated for sources that move by much more than the beamsize. This paper describes an analysis that includes a pattern of celestially fixed flux plus a source moving with a known trajectory. This technique allows the confusion noise to be modeled with nuisance parameters and removed even for sources that have not moved by many beamwidths. However, the detector noise is magnified if the motion is too small. Examples of the method applied to fast moving Y dwarfs and slow moving planets will be shown.

  18. A design for fluid management in space

    Science.gov (United States)

    Searby, N. E.

    1986-01-01

    Design features of a prototype generic fluid management system (FMS) for use in space are described. The FMS design is based on centrifugation of fluids in various phases, i.e., gas, liquid and solid. Fluids are pumped by positive displacement into the apex of a spinning conic chamber and migrate to the wide end, picking up rotational motion as they move. The motion separates the phases into layers so that density dependent valves at the wide end permit the phases to exit separately. Check valves permit flow in one direction only. The system was scheduled for flight testing in a Getaway Special cannister on-board a Shuttle mission early in 1986. Potential applications of the FMS system for water recycling on the Shuttle and commercial operations and closing the ecology on the Space Station and a GEO staging base are projected.

  19. Collisions in 3D Fluid Structure interactions problems

    OpenAIRE

    Hillairet, Matthieu; Takahashi, Takéo

    2009-01-01

    This paper deals with the system composed by a rigid ball moving into a viscous incompressible fluid, over a fixed horizontal plane. The equations of motion for the fluid are the Navier-Stokes equations and the equations for the motion of the rigid ball are obtained by applying Newton's laws. We show that for any weak solutions of the corresponding system satisfying the energy inequality, the rigid ball never touches the plane.

  20. Scattering methods in complex fluids

    CERN Document Server

    Chen, Sow-Hsin

    2015-01-01

    Summarising recent research on the physics of complex liquids, this in-depth analysis examines the topic of complex liquids from a modern perspective, addressing experimental, computational and theoretical aspects of the field. Selecting only the most interesting contemporary developments in this rich field of research, the authors present multiple examples including aggregation, gel formation and glass transition, in systems undergoing percolation, at criticality, or in supercooled states. Connecting experiments and simulation with key theoretical principles, and covering numerous systems including micelles, micro-emulsions, biological systems, and cement pastes, this unique text is an invaluable resource for graduate students and researchers looking to explore and understand the expanding field of complex fluids.

  1. Modeling and simulation of dust behaviors behind a moving vehicle

    Science.gov (United States)

    Wang, Jingfang

    Simulation of physically realistic complex dust behaviors is a difficult and attractive problem in computer graphics. A fast, interactive and visually convincing model of dust behaviors behind moving vehicles is very useful in computer simulation, training, education, art, advertising, and entertainment. In my dissertation, an experimental interactive system has been implemented for the simulation of dust behaviors behind moving vehicles. The system includes physically-based models, particle systems, rendering engines and graphical user interface (GUI). I have employed several vehicle models including tanks, cars, and jeeps to test and simulate in different scenarios and conditions. Calm weather, winding condition, vehicle turning left or right, and vehicle simulation controlled by users from the GUI are all included. I have also tested the factors which play against the physical behaviors and graphics appearances of the dust particles through GUI or off-line scripts. The simulations are done on a Silicon Graphics Octane station. The animation of dust behaviors is achieved by physically-based modeling and simulation. The flow around a moving vehicle is modeled using computational fluid dynamics (CFD) techniques. I implement a primitive variable and pressure-correction approach to solve the three dimensional incompressible Navier Stokes equations in a volume covering the moving vehicle. An alternating- direction implicit (ADI) method is used for the solution of the momentum equations, with a successive-over- relaxation (SOR) method for the solution of the Poisson pressure equation. Boundary conditions are defined and simplified according to their dynamic properties. The dust particle dynamics is modeled using particle systems, statistics, and procedure modeling techniques. Graphics and real-time simulation techniques, such as dynamics synchronization, motion blur, blending, and clipping have been employed in the rendering to achieve realistic appearing dust

  2. Development of a Photo-Fluidic Control Valve without Mechanical Moving Parts

    Science.gov (United States)

    Akagi, Tetsuya; Dohta, Shujiro

    An optical servo system is a new control system which can be used in hazardous environments; such as those with electromagnetic influence, radiation and so on. The purpose of our study is to develop such an optical control system. In our previous study, an optical servo valve in which the output differential pressure was proportional to input optical power had been developed. However, the dynamics of the valve depended on the time required to move the flapper membrane of a fluid booster amplifier using the lower flow rate from the photo-fluidic interface. In addition, the lifetime of the valve depends on that of the fluid booster amplifier that has mechanical moving parts. As a next step, we need to improve the dynamics and to get longer lifetime of the optical servo valve and try to develop another type of optical servo valve whose elements have no mechanical moving parts. In this paper, a photo-fluidic control valve which consists of the photo-fluidic interface and fluid amplifier only using fluidics is proposed. As a result, we found that the tested valve generated output differential pressure of + 80 kPa or -80 kPa according to applied optical power. By driving a pneumatic cylinder whose inner diameter is 16 mm with a stroke of 100 mm using the tested valve, we also confirmed that the tested valve has enough output fluid power to drive a small-sized pneumatic cylinder on the market.

  3. Local order variations in confined hard-sphere fluids

    OpenAIRE

    Nygård, Kim; Sarman, Sten; Kjellander, Roland

    2013-01-01

    Pair distributions of fluids confined between two surfaces at close distance are of fundamental importance for a variety of physical, chemical, and biological phenomena, such as interactions between macromolecules in solution, surface forces, and diffusion in narrow pores. However, in contrast to bulk fluids, properties of inhomogeneous fluids are seldom studied at the pair-distribution level. Motivated by recent experimental advances in determining anisotropic structure factors of confined f...

  4. Biology Notes.

    Science.gov (United States)

    School Science Review, 1982

    1982-01-01

    Presents procedures, exercises, demonstrations, and information on a variety of biology topics including labeling systems, biological indicators of stream pollution, growth of lichens, reproductive capacity of bulbous buttercups, a straw balance to measure transpiration, interaction of fungi, osmosis, and nitrogen fixation and crop production. (DC)

  5. Biological scaling and physics

    Indian Academy of Sciences (India)

    A R P Rau

    2002-09-01

    Kleiber’s law in biology states that the specific metabolic rate (metabolic rate per unit mass) scales as -1/4 in terms of the mass of the organism. A long-standing puzzle is the (- 1/4) power in place of the usual expectation of (- 1/3) based on the surface to volume ratio in three-dimensions. While recent papers by physicists have focused exclusively on geometry in attempting to explain the puzzle, we consider here a specific law of physics that governs fluid flow to show how the (- 1/4) power arises under certain conditions. More generally, such a line of approach that identifies a specific physical law as involved and then examines the implications of a power law may illuminate better the role of physics in biology.

  6. DEGRADATION OF AROMATIC COMPOUNDS USING MOVING BED BIOFILM REACTORS

    Directory of Open Access Journals (Sweden)

    B. Ayati, H. Ganjidoust, M. Mir Fattah

    2007-04-01

    Full Text Available For biological treatment of water, there are many different biofilm systems in use. Examples of them are trickling filters, rotating biological contactors, fixed media submerged biofilters, granular media biofilters and fluidized bed reactors. They all have their advantages and disadvantages. Hence, the Moving Bed Biofilm Reactor process was developed in Norway in the late 1980s and early 1990s to adopt the best features of the activated sludge process as well as those of the biofilter processes, without including the worst. Two cylindrical moving bed biofilm reactors were used in this study working in upflow stream conditions. Experiments have been done in aerobic batch flow regime. Laboratory experiments were conducted at room temperature (23–28C and synthetic wastewater comprising a composition of phenol and hydroquinone in each reactor as the main organic constituents, plus balanced nutrients and alkalinity were used to feed the reactor. The ratio of influent to effluent COD was determined at different retention times. The results indicated that the removal efficiency of each selected compound is affected by the detention time. At low phenol and hydroquinone concentration (from 700 to 1000 mg/L maximum removal efficiency (over 80 % was obtained. By further increasing in COD loading rate up to 3000 mg/L, a decrease in COD removal rate was occurred. In the reactor containing pyrogallol in COD of 1500 mg/L, the removal rate decreased to 10 percent because of its toxicity for microorganisms.

  7. 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 ... based on more than just the peritoneal fluid culture (which may be negative even if you have ...

  8. Rheological effect on thermocapillary flow of a liquid film jet painted on a moving boundary

    Institute of Scientific and Technical Information of China (English)

    HU; Wenrui(胡文瑞); HUI; W.H.(许为厚)

    2002-01-01

    In the present paper, a liquid (or melt) film of relatively high temperature ejected from a vessel and painted on the moving solid film is analyzed by using the second-order fluid model of the non-Newtonian fluid. The thermocapillary flow driven by the temperature gradient on the free surface of a Newtonian liquid film was discussed before. The effect of rheological fluid on thermocapillary flow is considered in the present paper. The analysis is based on the approximations of lubrication theory and perturbation theory. The equation of liquid height and the process of thermal hydrodynamics of the non-Newtonian liquid film are obtained, and the case of weak effect of the rheological fluid is solved in detail.

  9. A fluid particle model

    OpenAIRE

    Español, Pep

    1997-01-01

    We present a mechanistic model for a Newtonian fluid called fluid particle dynamics. By analyzing the concept of ``fluid particle'' from the point of view of a Voronoi tessellation of a molecular fluid, we propose an heuristic derivation of a dissipative particle dynamics algorithm that incorporates shear forces between dissipative particles. The inclusion of these non-central shear forces requires the consideration of angular velocities of the dissipative particles in order to comply with th...

  10. MHD visco elastic boundary layer flow with free convention past a continuous moving surface

    International Nuclear Information System (INIS)

    The behaviour of free convective boundary layer flow of an electrically conducting, viscoelastic, incompressible fluid over a continuously moving flat surface in presence of uniform magnetic field with constant suction is studied in this section. A uniform magnetic field is assumed to be applied perpendicular to the moving flat surface. The velocity and temperature field are obtained. The effect of R (small Reynold's number), M (Hartmann number), G (Grashoff number) and Ko (visco-elastic parameter) on velocity field and temperature field are discussed with the help of graphs. (author)

  11. Bioanalytical applications using supercritical fluid techniques.

    Science.gov (United States)

    Ríos, Angel; Zougagh, Mohammed; de Andrés, Fernando

    2010-01-01

    The bioanalytical applications of supercritical fluid techniques, such as supercritical fluid extraction (SFE) and supercritical fluid chromatography (SFC), are of increasing interest. The main role of these techniques is in the sample preparation and separation of biologically active compounds, particularly drugs and their metabolites, as well as endogenous compounds. An insight is given into the different types of extracting fluids and modifiers, detectors, stationary phases, mobile phases and collection strategies. A critical discussion is presented on the existing state of the art concerning the applications of SFC and SFE with a specific focus on its advantages and limitations in the bioanalytical field. New developments and the possibilities for routine work in the near future are also covered. PMID:21083113

  12. Radiation of charge uniformly moving in medium

    International Nuclear Information System (INIS)

    We analyze how the frequency dependence of the dielectric permittivity affects the electromagnetic field radiated by a point charge uniformly moving in medium. It turns out that a moving charge radiates at every velocity. We study the space distribution of the electromagnetic field and show that its oscillations are due to the time-dependent medium polarization induced by the moving charge. Spectral distributions of the radiated energy and the photon number are given. Consequences arising from the choice of polarization different from the usual one are discussed. The analysis of the Kramers-Kronig dispersion relations for the treated problems is given

  13. Fixing the shadows while moving the gnomon

    OpenAIRE

    Gangui, Alejandro

    2016-01-01

    It is a common practice to fix a vertical gnomon and study the moving shadow cast by it. This shows our local solar time and gives us a hint regarding the season in which we perform the observation. The moving shadow can also tell us our latitude with high precision. In this paper we propose to exchange the roles and while keeping the shadows fixed on the ground we will move the gnomon. This lets us understand in a simple way the relevance of the tropical lines of latitude and the behavior of...

  14. Moving black holes via singularity excision

    International Nuclear Information System (INIS)

    We present a singularity excision algorithm appropriate for numerical simulations of black holes moving throughout the computational domain. The method is an extension of the excision procedure previously used to obtain stable simulations of single, non-moving black holes. The excision procedure also shares elements used in recent work to study the dynamics of a scalar field in the background of a single, boosted black hole. The excision method is tested with single black-hole evolutions using a coordinate system in which the coordinate location of the black hole, and thus the excision boundary, moves throughout the computational domain

  15. CoGet:Things Move People Around

    OpenAIRE

    Speed, Chris

    2014-01-01

    Co-things is a public experiment that uses software to predict where things need to be, and borrows the legs of humans to move them.The CoGet workshop and experiments introduce the CoGet iPhone software that reveals where things want to go, and asks the public to move them on their behalf. Connected to the net, and able to read the social complexity of a local area, CoGet lets objects control people’s movements by predicting where they need to be, and borrowing the legs of a human to move the...

  16. Fluid Movement and Creativity

    Science.gov (United States)

    Slepian, Michael L.; Ambady, Nalini

    2012-01-01

    Cognitive scientists describe creativity as fluid thought. Drawing from findings on gesture and embodied cognition, we hypothesized that the physical experience of fluidity, relative to nonfluidity, would lead to more fluid, creative thought. Across 3 experiments, fluid arm movement led to enhanced creativity in 3 domains: creative generation,…

  17. Exoplanet Caught on the Move

    Science.gov (United States)

    2010-06-01

    For the first time, astronomers have been able to directly follow the motion of an exoplanet as it moves from one side of its host star to the other. The planet has the smallest orbit so far of all directly imaged exoplanets, lying almost as close to its parent star as Saturn is to the Sun. Scientists believe that it may have formed in a similar way to the giant planets in the Solar System. Because the star is so young, this discovery proves that gas giant planets can form within discs in only a few million years, a short time in cosmic terms. Only 12 million years old, or less than three-thousandths of the age of the Sun, Beta Pictoris is 75% more massive than our parent star. It is located about 60 light-years away towards the constellation of Pictor (the Painter) and is one of the best-known examples of a star surrounded by a dusty debris disc [1]. Earlier observations showed a warp of the disc, a secondary inclined disc and comets falling onto the star. "Those were indirect, but tell-tale signs that strongly suggested the presence of a massive planet, and our new observations now definitively prove this," says team leader Anne-Marie Lagrange. "Because the star is so young, our results prove that giant planets can form in discs in time-spans as short as a few million years." Recent observations have shown that discs around young stars disperse within a few million years, and that giant planet formation must occur faster than previously thought. Beta Pictoris is now clear proof that this is indeed possible. The team used the NAOS-CONICA instrument (or NACO [2]), mounted on one of the 8.2-metre Unit Telescopes of ESO's Very Large Telescope (VLT), to study the immediate surroundings of Beta Pictoris in 2003, 2008 and 2009. In 2003 a faint source inside the disc was seen (eso0842), but it was not possible to exclude the remote possibility that it was a background star. In new images taken in 2008 and spring 2009 the source had disappeared! The most recent

  18. Existence of a weak solution to a nonlinear fluid-structure interaction problem modeling the flow of an incompressible, viscous fluid in a cylinder with deformable walls

    OpenAIRE

    Muha, Boris; Canic, Suncica

    2012-01-01

    We study a nonlinear, unsteady, moving boundary, fluid-structure interaction (FSI) problem arising in modeling blood flow through elastic and viscoelastic arteries. The fluid flow, which is driven by the time-dependent pressure data, is governed by 2D incompressible Navier-Stokes equations, while the elastodynamics of the cylindrical wall is modeled by the 1D cylindrical Koiter shell model. Two cases are considered: the linearly viscoelastic and the linearly elastic Koiter shell. The fluid an...

  19. Quantum Biology

    Directory of Open Access Journals (Sweden)

    Alessandro Sergi

    2009-06-01

    Full Text Available A critical assessment of the recent developmentsof molecular biology is presented.The thesis that they do not lead to a conceptualunderstanding of life and biological systems is defended.Maturana and Varela's concept of autopoiesis is briefly sketchedand its logical circularity avoided by postulatingthe existence of underlying living processes,entailing amplification from the microscopic to the macroscopic scale,with increasing complexity in the passage from one scale to the other.Following such a line of thought, the currently accepted model of condensed matter, which is based on electrostatics and short-ranged forces,is criticized. It is suggested that the correct interpretationof quantum dispersion forces (van der Waals, hydrogen bonding, and so onas quantum coherence effects hints at the necessity of includinglong-ranged forces (or mechanisms for them incondensed matter theories of biological processes.Some quantum effects in biology are reviewedand quantum mechanics is acknowledged as conceptually important to biology since withoutit most (if not all of the biological structuresand signalling processes would not even exist. Moreover, it is suggested that long-rangequantum coherent dynamics, including electron polarization,may be invoked to explain signal amplificationprocess in biological systems in general.

  20. Development of a permeability-limited model of the human brain and cerebrospinal fluid (CSF) to integrate known physiological and biological knowledge: Estimating time varying CSF drug concentrations and their variability using in vitro data.

    Science.gov (United States)

    Gaohua, Lu; Neuhoff, Sibylle; Johnson, Trevor N; Rostami-Hodjegan, Amin; Jamei, Masoud

    2016-06-01

    A 4-compartment permeability-limited brain (4Brain) model consisting of brain blood, brain mass, cranial and spinal cerebrospinal fluid (CSF) compartments has been developed and incorporated into a whole body physiologically-based pharmacokinetic (PBPK) model within the Simcyp Simulator. The model assumptions, structure, governing equations and system parameters are described. The model in particular considers the anatomy and physiology of the brain and CSF, including CSF secretion, circulation and absorption, as well as the function of various efflux and uptake transporters existing on the blood-brain barrier (BBB) and blood-CSF barrier (BCSFB), together with the known parameter variability. The model performance was verified using in vitro data and clinical observations for paracetamol and phenytoin. The simulated paracetamol spinal CSF concentration is comparable with clinical lumbar CSF data for both intravenous and oral doses. Phenytoin CSF concentration-time profiles in epileptic patients were simulated after accounting for disease-induced over-expression of efflux transporters within the BBB. Various 'what-if' scenarios, involving variation of specific drug and system parameters of the model, demonstrated that the 4Brain model is able to simulate the possible impact of transporter-mediated drug-drug interactions, the lumbar puncture process and the age-dependent change in the CSF turnover rate on the local PK within the brain. PMID:27236639

  1. Moving objects management models, techniques and applications

    CERN Document Server

    Meng, Xiaofeng; Xu, Jiajie

    2014-01-01

    This book describes the topics of moving objects modeling and location tracking, indexing and querying, clustering, location uncertainty, traffic aware navigation and privacy issues as well as the application to intelligent transportation systems.

  2. Being Moved: Linguistic Representation and Conceptual Structure

    Directory of Open Access Journals (Sweden)

    Milena eKuehnast

    2014-11-01

    Full Text Available This study explored the organisation of the semantic field and the conceptual structure of moving experiences by investigating German-language expressions referring to the emotional state of being moved. We used present and past participles of eight psychological verbs as primes in a free word-association task, as these grammatical forms place their conceptual focus on the eliciting situation and on the felt emotional state, respectively. By applying a taxonomy of basic knowledge types and computing the Cognitive Salience Index, we identified joy and sadness as key emotional ingredients of being moved, and significant life events and art experiences as main elicitors of this emotional state. Metric multidimensional scaling analyses of the semantic field revealed that the core terms designate a cluster of emotional states characterised by low degrees of arousal and slightly positive valence, the latter due to a nearly balanced representation of positive and negative elements in the conceptual structure of being moved.

  3. Monkeys Move Robotic Wheelchairs with Their Thoughts

    Science.gov (United States)

    ... gov/medlineplus/news/fullstory_157593.html Monkeys Move Robotic Wheelchairs With Their Thoughts Scientists say technology might ... made it possible for monkeys to operate a robotic wheelchair using only the monkey's thoughts say the ...

  4. Moving potentials and completeness of wave operators

    International Nuclear Information System (INIS)

    For the generalized charge transfer model, i.e. for moving and time-dependent short range potentials the existence and completeness, defined in a suitable manner, of the wave operators are shown. 18 refs

  5. Engineering fluid mechanics

    CERN Document Server

    Yamaguchi, Hiroshi

    2008-01-01

    This book is intended to serve as a unique and comprehensive textbook for scientists and engineers as well as advanced students in thermo-fluid courses. It provides an intensive monograph essential for understanding dynamics of ideal fluid, Newtonian fluid, non-Newtonian fluid and magnetic fluid. These distinct, yet intertwined subjects are addressed in an integrated manner. It starts with coherent treatment of fundamental continuum mechanics, with an emphasis on the intrinsic angular momentum, by which the concepts of ferrohydrodynamics are progressively built up, and serve as a foundation fo

  6. 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

  7. Quantum turbulence generated by moving grids

    OpenAIRE

    Munday, Lydia

    2014-01-01

    We present experimental results on quantum grid turbulence produced by moving grids within superfluid 4He, both at millikelvin temperatures, with an oscillating grid, and at temperatures above 1.4 K with a linearly moving grid. Floppy devices were used at millikelvin temperatures to produce quantum turbulence. We investigated the frequency dependence of the turbulent drag on an oscillating grid. At high velocities, the turbulent drag is independent of frequency and similar to what was measure...

  8. Forecasting with Optimized Moving Local Regression

    OpenAIRE

    Fedorov, Valery V.; Hackl, Peter; Müller, Werner

    1992-01-01

    This paper empirically demonstrates the relative merits of the optimal choice of the weight function in a moving local regression as suggested by Fedorov et al., (1993) over traditional weight functions which ignore the form of the local model. The discussion is based on a task that is imbedded into the smoothing methodology, namely the forecasting of business time series data with the help of a one-sided moving local regression model. (author's abstract)

  9. Moving Black Holes in 3D

    OpenAIRE

    Gomez, R.; Lehner, L.; Marsa, R. L.; Winicour, J.

    1997-01-01

    We model a radiating, moving black hole in terms of a worldtube-nullcone boundary value problem. We evolve this data in the region interior to the worldtube but exterior to a trapped surface by means of a characteristic evolution based upon a family of ingoing null hypersurfaces. Data on the worldtube is induced from a Schwarzschild spacetime but the worldtube is allowed to move relative to the static Schwarzschild trajectories. When the worldtube is stationary (static or rotating in place), ...

  10. Fusion Framework for Moving-Object Classification

    OpenAIRE

    Chavez-Garcia, Ricardo Omar; Vu, Trung-Dung; Aycard, Olivier; Tango, Fabio

    2013-01-01

    Perceiving the environment is a fundamental task for Advance Driver Assistant Systems. While simultaneous localization and mapping represents the static part of the environment, detection and tracking of moving objects aims at identifying the dynamic part. Knowing the class of the moving objects surrounding the vehicle is a very useful information to correctly reason, decide and act according to each class of object, e.g. car, truck, pedestrian, bike, etc. Active and passive sensors provide u...

  11. Moving Object Tracking Techniques: A Critical Review

    OpenAIRE

    Sandeep Kumar Patel; Agya Mishra

    2013-01-01

    Moving Object Tracking is one of the challenging problems in the field of computer vision, surveillance, traffic monitoring, video compression etc. The goal of object tracking is to locate a moving object in consecutive video frames. Normally a video tracking system combines three stages of data treating; object extraction, objectrecognition & tracking, and decisions about activities. This paper presents a critical review of various video object tracking techniques like point tracking, kernel...

  12. Moving the Maasai: A Colonial Misadventure

    OpenAIRE

    Hughes, Lotte.

    2006-01-01

    The history of the Maasai moves, land alienation and resistance in colonial British East Africa. In 1904, in order to make way for white settlers in what was to become Kenya, the Maasai were forcibly moved into two reserves, robbing them of the best part of their land in British East Africa. Using unique oral testimony and archival evidence, this book tells the true story behind the making of the 'White Highlands', and the repercussions of these events to the present day.

  13. Computational methods for fluid dynamics

    CERN Document Server

    Ferziger, Joel H

    2002-01-01

    In its 3rd revised and extended edition the book offers an overview of the techniques used to solve problems in fluid mechanics on computers and describes in detail those most often used in practice. Included are advanced methods in computational fluid dynamics, like direct and large-eddy simulation of turbulence, multigrid methods, parallel computing, moving grids, structured, block-structured and unstructured boundary-fitted grids, free surface flows. The 3rd edition contains a new section dealing with grid quality and an extended description of discretization methods. The book shows common roots and basic principles for many different methods. The book also contains a great deal of practical advice for code developers and users, it is designed to be equally useful to beginners and experts. The issues of numerical accuracy, estimation and reduction of numerical errors are dealt with in detail, with many examples. A full-feature user-friendly demo-version of a commercial CFD software has been added, which ca...

  14. Membrane fluids and Dirac membrane fluids

    CERN Document Server

    Ivanov, M G

    2004-01-01

    The relation between two different methods of membrane fluid description is clarified by construction of combined method. Dirac membrane field appears naturally in new approach. It provides a possibility to consider new aspects of electrodynamics-type theories with electric and magnetic sources. The membrane fluid models automatically prohibit simulatenos existence of electric and magnetic currents. Possible applications to the dark energy problem are mentioned.

  15. Development of a Parallel Overset Grid Framework for Moving Body Simulations in OpenFOAM

    OpenAIRE

    Dominic Chandar

    2015-01-01

    OpenFOAM is an industry-standard Open-Source fluid dynamics code that is used to solve the Navier-Stokes equations for a variety of flow situations. It is currently being used extensively by researchers to study a plethora of physical problems ranging from fundamental fluid dynamics to complex multiphase flows. When it comes to modeling the flow surrounding moving bodies that involve large displacements such as that of ocean risers, sinking of a ship, or the free-flight of an insect, it is cu...

  16. Quantum Biology

    CERN Document Server

    Sergi, Alessandro

    2009-01-01

    A critical assessment of the recent developments of molecular biology is presented. The thesis that they do not lead to a conceptual understanding of life and biological systems is defended. Maturana and Varela's concept of autopoiesis is briefly sketched and its logical circularity avoided by postulating the existence of underlying {\\it living processes}, entailing amplification from the microscopic to the macroscopic scale, with increasing complexity in the passage from one scale to the other. Following such a line of thought, the currently accepted model of condensed matter, which is based on electrostatics and short-ranged forces, is criticized. It is suggested that the correct interpretation of quantum dispersion forces (van der Waals, hydrogen bonding, and so on) as quantum coherence effects hints at the necessity of including long-ranged forces (or mechanisms for them) in condensed matter theories of biological processes. Some quantum effects in biology are reviewed and quantum mechanics is acknowledge...

  17. 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.

  18. 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.

  19. Application of a liquid chromatographic procedure for the analysis of penicillin antibiotics in biological fluids and pharmaceutical formulations using sodium dodecyl sulphate/propanol mobile phases and direct injection.

    Science.gov (United States)

    Rambla-Alegre, Maria; Martí-Centelles, Rosa; Esteve-Romero, Josep; Carda-Broch, Samuel

    2011-07-29

    A direct injection liquid chromatography procedure was developed for the simultaneous determination of four penicillin antibiotics (amoxicillin, ampicillin, cloxacillin and dicloxacillin) in pharmaceutical formulations and physiological fluids (urine) using hybrid micellar mobile phases. These antimicrobials are used to treat gastrointestinal and systemic infections. The four penicillins were analysed using a Zorbax C18 reversed-phase column and detected at 210 nm. These antibiotics were separated by an interpretive optimisation procedure based on the accurate description of the retention and shape of the chromatographic peaks. Antibiotics were eluted in less than 16 min with no interference by the urine protein band or endogenous compounds using the mobile phase 0.11 M sodium dodecyl sulphate-6% propanol-0.01 M NaH(2)PO(4) buffered at pH 3. The method was validated according to the Food and Drug Administration guideline, including analytical parameters such as linearity (R(2)>0.993), intra- and inter-day precisions (RSD, %: 0.1-4.4 and 1.2-5.9, respectively), and robustness for the four compounds. This method is sensitive enough for the routine analysis of penicillins at therapeutic urine levels, with limits of detection in the 1.5-15 ng mL(-1) range and limits of quantification of 50 ng mL(-1). Recoveries in a micellar medium and a spiked urine matrix were in the 92.4-108.2% and 96-110% ranges, respectively. Finally, the method was successfully applied to determine these antibiotics in urine samples and pharmaceutical formulations. PMID:21190691

  20. A general numerical procedure for the treatment of moving interfaces in implicit continuous Eulerian (ICE) hydrodynamics

    International Nuclear Information System (INIS)

    The implicit continuous Eulerian (ICE) finite difference method in hydrodynamic computations has proven very successful when applied to flow situations in which there are excessive fluid distortions. Code logic becomes exceedingly complex, however, if the boundaries of the fluid domain are material interfaces whose orientations with respect to the Eulerian grid evolve during the calculation. It is shown in this article that within the ICE methodology it is possible to express the discrete mass conservation condition in an identical form for all computational cells, even those containing, or close to, moving fluid boundaries. From this basis a generalized ICE algorithm is built up alleviating many of the difficulties associated with complicated configurations of free and structure boundaries. In particular, an effective treatment of slug impact with fluid-structure interaction is readily formulated. To illustrate the technique in practical situations, the method has been incorporated into a version of the coupled fluid-structure code SEURBNUK-EURDYN, used for LMFBR safety analysis, and a number of fluid-gas, fluid-structure situations are analyzed. Results are compared with analytic solutions, experimental measurement, and/or other code predictions, as appropriate. Two oblique, slug impact situations are included. (author) 37 refs., 24 figs