Sample records for vacuum fluctuation effects

  1. The effects of vacuum fluctuations on teleportation of quantum Fisher information. (United States)

    Jin, Yao


    The teleported quantum Fisher information of the phase parameter of atomic state is studied in consideration of vacuum fluctuations. Our results show that the teleported information is determined by the wavelength of the atoms as well as the distance of teleportation. When the wavelength of the atoms is much smaller than the teleportation distance, the teleported information decays with time and the decay rates are determined by the spontaneous emission rate of the atoms. However, when the wavelength of the atoms is much larger than the teleportation distance, the teleported information remains unchanged with time. The information of the phase parameter of atomic state has been absolutely transmitted.

  2. Vacuum fluctuations of the supersymmetric field in curved background

    Energy Technology Data Exchange (ETDEWEB)

    Bilic, Neven, E-mail: [Rudjer Boskovic Institute, POB 180, HR-10002 Zagreb (Croatia); Domazet, Silvije, E-mail: [Rudjer Boskovic Institute, POB 180, HR-10002 Zagreb (Croatia); Guberina, Branko, E-mail: [Rudjer Boskovic Institute, POB 180, HR-10002 Zagreb (Croatia)


    We study a supersymmetric model in curved background spacetime. We calculate the effective action and the vacuum expectation value of the energy momentum tensor using a covariant regularization procedure. A soft supersymmetry breaking induces a nonzero contribution to the vacuum energy density and pressure. Assuming the presence of a cosmic fluid in addition to the vacuum fluctuations of the supersymmetric field an effective equation of state is derived in a self-consistent approach at one loop order. The net effect of the vacuum fluctuations of the supersymmetric fields in the leading adiabatic order is a renormalization of the Newton and cosmological constants.

  3. Can gravitational microlensing by vacuum fluctuations be observed?

    CERN Document Server

    Carlip, S


    Although the prospect is more plausible than it might appear, the answer to the title question is, unfortunately, "probably not." Quantum fluctuations of vacuum energy can focus light, and while the effect is tiny, the distribution of fluctuations is highly non-Gaussian, offering hope that relatively rare "large" fluctuations might be observable. I show that although gravitational microlensing by such fluctuations become important at scales much larger than the Planck length, the possibility of direct observation remains remote, although there is a small chance that cumulative effects over cosmological distances might be detectable. The effect is sensitive to the size of the Planck scale, however, and could offer a new test of TeV-scale gravity.

  4. Parametric Amplification of Vacuum Fluctuations in a Spinor Condensate

    DEFF Research Database (Denmark)

    Klempt, C.; Topic, O.; Gebreyesus, G.


    Parametric amplification of vacuum fluctuations is crucial in modern quantum optics, enabling the creation of squeezing and entanglement. We demonstrate the parametric amplification of vacuum fluctuations for matter waves using a spinor F=2 87Rb condensate. Interatomic interactions lead...... to correlated pair creation in the mF=±1 states from an initial mF=0 condensate, which acts as a vacuum for mF≠0. Although this pair creation from a pure mF=0 condensate is ideally triggered by vacuum fluctuations, unavoidable spurious initial mF=±1 atoms induce a classical seed which may become the dominant...... triggering mechanism. We show that pair creation is insensitive to a classical seed for sufficiently large magnetic fields, demonstrating the dominant role of vacuum fluctuations. The presented system thus provides a direct path towards the generation of nonclassical states of matter....

  5. Semiconductor cavity QED: Bandgap induced by vacuum fluctuations


    Espinosa-Ortega, T.; Kyriienko, O.; Kibis, O. V.; Shelykh, I. A.


    We consider theoretically a semiconductor nanostructure embedded in one-dimensional microcavity and study the modification of its electron energy spectrum by the vacuum fluctuations of the electromagnetic field. To solve the problem, a non-perturbative diagrammatic approach based on the Green's function formalism is developed. It is shown that the interaction of the system with the vacuum fluctuations of the optical cavity opens gaps within the valence band of the semiconductor. The approach ...

  6. Probing electric and magnetic vacuum fluctuations with quantum dots


    Tighineanu, Petru; Andersen, Mads Lykke; Sørensen, Anders Søndberg; Stobbe, Søren; Lodahl, Peter


    The electromagnetic-vacuum-field fluctuations are intimately linked to the process of spontaneous emission of light. Atomic emitters cannot probe electric- and magnetic-field fluctuations simultaneously because electric and magnetic transitions correspond to different selection rules. In this paper we show that semiconductor quantum dots are fundamentally different and are capable of mediating electric-dipole, magnetic-dipole, and electric-quadrupole transitions on a single electronic resonan...

  7. Cooling and entanglement of multimode graphene resonators via vacuum fluctuations (United States)

    Ribeiro, Sofia; Terças, Hugo


    Sympathetic laser cooling of a single mode graphene membrane coupled to an atomic cloud interacting via Casimir-Polder forces has been recently proposed. Here, we extend this study to the effect of secondary graphene membrane whose frequency may be far or close to resonance. We show that if the two mechanical modes are close together, it is possible to simultaneously cool both modes. Conversely, if the two frequencies are set far apart, the secondary mode does not affect the cooling of the first one. We also study the entanglement properties of the steady-state using the logarithmic negativity. We show how stationary mechanical entanglement between two graphene sheets can be generated by means of vacuum fluctuations. Moreover, we find that, within feasible experimental parameters, large steady-state acoustomechanical entanglement, i.e. entanglement between the phononic and mechanical mode, {E}N≈ 5, can be generated.

  8. Vacuum Fluctuations, Cosmogenesis and Prime Number Gaps (United States)

    Berezin, Alexander A.


    Starting from E.Tryon (1973), idea of cosmogenesis through quantum tunnelling "from nothing" became popular. Both complimentary streams of it, inflationary models (Guth, Linde) and quantum parallelism (Everett, Deutsch), require some starting point as, e.g., concretisation of Leibnitz Principle (Omnibus ex nihil decendis sufficit unum). This leads to propositional conjecture (axiom?) that (meta)physical "Platonic Pressure" of infinitude of numbers and Cantor "alephs" becomes an engine for self-generation of physical universe directly out of mathematics: inexhaustibility of Number Theory (NT) drives cosmogenesis. While physics in other quantum branches of inflating universe (Megaverse) can be (arbitrary) different from ours, NT is not (it is unique, absolute, immutable and infinitely resourceful). Energy-time uncertainty principle (UP) allows indefinite lifetime provided we start from total zero energy. Analogue of UP in NT is theorem by H.Maier (1981) stating the existence of arbitrary long trails of isolated primes such that each next gap is arbitrary greater than average gap (logN). On physical level these arbitrary large deviations from Prime Number Theorem translate into permissiveness of (arbitrary) large quantum fluctuations.

  9. Planck's Radiation Law: Thermal Excitations of Vacuum Induced Fluctuations

    Directory of Open Access Journals (Sweden)

    Ogiba F.


    Full Text Available The second Planck’s radiation law is derived considering that “resonators” induced by the vacuum absorb thermal excitations as additional fluctuations. The maximum energy transfer, as required by the maximum entropy equilibrium, occurs when the frequencies of these two kind of vibrations are equal. The motion resembles that of the coherent states of the quantum oscillator, as originally pointed by Schrödinger [1]. The resulting variance, due to random phases, coincides with that used by Einstein to reproduce the first Planck’s radiation law from his thermal fluctuation equation [2].

  10. Electron fluctuation induced resonance broadening in nano electromechanical systems: the origin of shear force in vacuum. (United States)

    Siria, A; Barois, T; Vilella, K; Perisanu, S; Ayari, A; Guillot, D; Purcell, S T; Poncharal, P


    This article presents a study of the poorly understood "shear-force" used in an important class of near-field instruments that use mechanical resonance feedback detection. In the case of a metallic probe near a metallic surface in vacuum, we show that in the 10-60 nm range there is no such a thing as a shear-force in the sense of the nonconservative friction force. Fluctuations of the oscillator resonance frequency, likely induced by local charge variations, could account for the reported effects in the literature without introducing a dissipative force.

  11. Fluctuation of a Piston in Vacuum Induced by Thermal Radiation Pressure (United States)

    Inui, Norio


    We consider the displacement of a piston dividing a vacuum cavity at a finite temperature T induced by fluctuations in the thermal radiation pressure. The correlation function of the thermal radiation pressure is calculated using the theoretical framework developed by Barton, which was first applied to the fluctuation of the Casimir force at absolute zero. We show that the variance of the radiation pressure at a fixed point is proportional to T8 and evaluate the mean square displacement for a piston with a small cross section in a characteristic correlation timescale ħ/(kBT). At room temperature, the contribution of the thermal radiation to the fluctuation is larger than that of the vacuum fluctuation.

  12. Electromagnetic vacuum fluctuations around a cosmic string in de Sitter spacetime

    Energy Technology Data Exchange (ETDEWEB)

    Saharian, A.A.; Saharyan, N.A. [Yerevan State University, Department of Physics, Yerevan (Armenia); Manukyan, V.F. [Gyumri State Pedagogical Institute, Department of Physics and Mathematics, Gyumri (Armenia)


    The electromagnetic field correlators are evaluated around a cosmic string in background of (D + 1)-dimensional dS spacetime assuming that the field is prepared in the Bunch-Davies vacuum state. The correlators are presented in the decomposed form where the string-induced topological parts are explicitly extracted. With this decomposition, the renormalization of the local vacuum expectation values (VEVs) in the coincidence limit is reduced to the one for dS spacetime in the absence of the cosmic string. The VEVs of the squared electric and magnetic fields, and of the vacuum energy density are investigated. Near the string they are dominated by the topological contributions and the effects induced by the background gravitational field are small. In this region, the leading terms in the topological contributions are obtained from the corresponding VEVs for a string on the Minkowski bulk multiplying by the conformal factor. At distances from the string larger than the curvature radius of the background geometry, the pure dS parts in the VEVs dominate. In this region, for spatial dimensions D > 3, the influence of the gravitational field on the topological contributions is crucial and the corresponding behavior is essentially different from that for a cosmic string on the Minkowski bulk. There are well-motivated inflationary models which produce cosmic strings. We argue that, as a consequence of the quantum-to-classical transition of super-Hubble electromagnetic fluctuations during inflation, in the post-inflationary era these strings will be surrounded by large-scale stochastic magnetic fields. These fields could be among the distinctive features of the cosmic strings produced during the inflation and also of the corresponding inflationary models. (orig.)

  13. Spontaneous excitation of a circularly accelerated atom coupled with vacuum Dirac field fluctuations

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jing [Institute of Physics and Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Education, Hunan Normal University, Changsha, Hunan 410081 (China); Hu, Jiawei [Center for Nonlinear Science and Department of Physics, Ningbo University, Ningbo, Zhejiang 315211 (China); Yu, Hongwei, E-mail: [Institute of Physics and Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Education, Hunan Normal University, Changsha, Hunan 410081 (China); Center for Nonlinear Science and Department of Physics, Ningbo University, Ningbo, Zhejiang 315211 (China)


    We study the spontaneous excitation of a circularly accelerated atom coupled with vacuum Dirac field fluctuations by separately calculating the contribution to the excitation rate of vacuum fluctuations and a cross term which involves both vacuum fluctuations and radiation reaction, and demonstrate that although the spontaneous excitation for the atom in its ground state would occur in vacuum, such atoms in circular motion do not perceive a pure thermal radiation as their counterparts in linear acceleration do since the transition rates of the atom do not contain the Planckian factor characterizing a thermal bath. We also find that the contribution of the cross term that plays the same role as that of radiation reaction in the scalar and electromagnetic fields cases differs for atoms in circular motion from those in linear acceleration. This suggests that the conclusion drawn for atoms coupled with the scalar and electromagnetic fields that the contribution of radiation reaction to the mean rate of change of atomic energy does not vary as the trajectory of the atom changes from linear acceleration to circular motion is not a general trait that applies to the Dirac field where the role of radiation reaction is played by the cross term. - Highlights: • Spontaneous excitation of a circularly accelerated atom is studied. • The atom interacts with the Dirac field through nonlinear coupling. • A cross term involving vacuum fluctuations and radiation reaction contributes. • The atom in circular motion does not perceive pure thermal radiation. • The contribution of the cross term changes as the atomic trajectory varies.

  14. Einstein-Langevin and Einstein-Fokker-Planck equations for Oppenheimer-Snyder gravitational collapse in a spacetime with conformal vacuum fluctuations (United States)

    Miller, Steven David


    A consistent extension of the Oppenheimer-Snyder gravitational collapse formalism is presented which incorporates stochastic, conformal, vacuum fluctuations of the metric tensor. This results in a tractable approach to studying the possible effects of vacuum fluctuations on collapse and singularity formation. The motivation here, is that it is known that coupling stochastic noise to a classical field theory can lead to workable methodologies that accommodate or reproduce many aspects of quantum theory, turbulence or structure formation. The effect of statistically averaging over the metric fluctuations gives the appearance of a deterministic Riemannian structure, with an induced non-vanishing cosmological constant arising from the nonlinearity. The Oppenheimer-Snyder collapse of a perfect fluid or dust star in the fluctuating or `turbulent' spacetime, is reformulated in terms of nonlinear Einstein-Langevin field equations, with an additional noise source in the energy-momentum tensor. The smooth deterministic worldlines of collapsing matter within the classical Oppenheimer-Snyder model, now become nonlinear Brownian motions due to the backreaction induced by vacuum fluctuations. As the star collapses, the matter worldlines become increasingly randomized since the backreaction coupling to the vacuum fluctuations is nonlinear; the input assumptions of the Hawking-Penrose singularity theorems should then be violated. Solving the nonlinear Einstein-Langevin field equation for collapse - via the Ito interpretation - gives a singularity-free solution, which is equivalent to the original Oppenheimer solution but with higher-order stochastic corrections; the original singular solution is recovered in the limit of zero vacuum fluctuations. The `geometro-hydrodynamics' of noisy gravitational collapse, were also translated into an equivalent mathematical formulation in terms of nonlinear Einstein-Fokker-Planck (EFP) continuity equations with respect to comoving coordinates

  15. Vacuum energy density fluctuations in Minkowski and Casimir states via smeared quantum fields and point separation (United States)

    Phillips, Nicholas G.; Hu, B. L.


    We present calculations of the variance of fluctuations and of the mean of the energy momentum tensor of a massless scalar field for the Minkowski and Casimir vacua as a function of an intrinsic scale defined by a smeared field or by point separation. We point out that, contrary to prior claims, the ratio of variance to mean-squared being of the order unity is not necessarily a good criterion for measuring the invalidity of semiclassical gravity. For the Casimir topology we obtain expressions for the variance to mean-squared ratio as a function of the intrinsic scale (defined by a smeared field) compared to the extrinsic scale (defined by the separation of the plates, or the periodicity of space). Our results make it possible to identify the spatial extent where negative energy density prevails which could be useful for studying quantum field effects in worm holes and baby universes, and for examining the design feasibility of real-life ``time machines.'' For the Minkowski vacuum we find that the ratio of the variance to the mean-squared, calculated from the coincidence limit, is identical to the value of the Casimir case at the same limit for spatial point separation while identical to the value of a hot flat space result with a temporal point separation. We analyze the origin of divergences in the fluctuations of the energy density and discuss choices in formulating a procedure for their removal, thus raising new questions about the uniqueness and even the very meaning of regularization of the energy momentum tensor for quantum fields in curved or even flat spacetimes when spacetime is viewed as having an extended structure.

  16. Effective cosmological constant induced by stochastic fluctuations of Newton's constant

    Directory of Open Access Journals (Sweden)

    Marco de Cesare


    Full Text Available We consider implications of the microscopic dynamics of spacetime for the evolution of cosmological models. We argue that quantum geometry effects may lead to stochastic fluctuations of the gravitational constant, which is thus considered as a macroscopic effective dynamical quantity. Consistency with Riemannian geometry entails the presence of a time-dependent dark energy term in the modified field equations, which can be expressed in terms of the dynamical gravitational constant. We suggest that the late-time accelerated expansion of the Universe may be ascribed to quantum fluctuations in the geometry of spacetime rather than the vacuum energy from the matter sector.

  17. VAK, vacuum fluctuation and the mass spectrum of high energy particle physics

    CERN Document Server

    El-Naschie, M S


    We introduce a fundamental hypothesis identifying quantum vacuum fluctuation with the vague attractor of Kolmogorov, the so-called VAK. This Hamiltonian conterpart of a dissipative attractor is then modelled by epsilon sup ( supinfinity sup ) , topology as a 'limit set' of a wild dynamics generated by Moebius-like transformation of space. We proceed as follows: First we give an introduction to the epsilon sup ( supinfinity sup ) quantum spacetime theory from the point of view of nonlinear dynamics, complexity, string and KAM theory. Subsequently we give without proof several theorems and conjectures that we consider to be fundamental to the foundation of any general theory for high energy particles interaction. The final picture seems to be a synthesis between compactified Kleinian groups acting on an essentially nonlinear dynamics of a KAM system which enables us to give a very accurate estimation of the mass spectrum of the standard model and further still we are granted a glimpse into the physics of grand ...

  18. Multiphoton Effects Enhanced due to Ultrafast Photon-Number Fluctuations (United States)

    Spasibko, Kirill Yu.; Kopylov, Denis A.; Krutyanskiy, Victor L.; Murzina, Tatiana V.; Leuchs, Gerd; Chekhova, Maria V.


    The rate of an n -photon effect generally scales as the n th order autocorrelation function of the incident light, which is high for light with strong photon-number fluctuations. Therefore, "noisy" light sources are much more efficient for multiphoton effects than coherent sources with the same mean power, pulse duration, and repetition rate. Here we generate optical harmonics of the order of 2-4 from a bright squeezed vacuum, a state of light consisting of only quantum noise with no coherent component. We observe up to 2 orders of magnitude enhancement in the generation of optical harmonics due to ultrafast photon-number fluctuations. This feature is especially important for the nonlinear optics of fragile structures, where the use of a noisy pump can considerably increase the effect without overcoming the damage threshold.

  19. Vacuum level effects on gait characteristics for unilateral transtibial amputees with elevated vacuum suspension. (United States)

    Xu, Hang; Greenland, Kasey; Bloswick, Donald; Zhao, Jie; Merryweather, Andrew


    The elevated vacuum suspension system has demonstrated unique health benefits for amputees, but the effect of vacuum pressure values on gait characteristics is still unclear. The purpose of this study was to investigate the effects of elevated vacuum levels on temporal parameters, kinematics and kinetics for unilateral transtibial amputees. Three-dimensional gait analysis was conducted in 9 unilateral transtibial amputees walking at a controlled speed with five vacuum levels ranging from 0 to 20inHg, and also in 9 able-bodied subjects walking at self-preferred speed. Repeated ANOVA and Dunnett's t-test were performed to determine the effect of vacuum level and limb for within subject and between groups. The effect of vacuum level significantly affected peak hip external rotation and external knee adduction moment. Maximum braking and propulsive ground reaction forces generally increased for the residual limb and decreased for the intact limb with increasing vacuum. Additionally, the intact limb experienced an increased loading due to gait asymmetry for several variables. There was no systematic vacuum level effect on gait. Higher vacuum levels, such as 15 and 20inHg, were more comfortable and provided some relief to the intact limb, but may also increase the risk of osteoarthritis of the residual limb due to the increased peak external hip and knee adduction moments. Very low vacuum should be avoided because of the negative effects on gait symmetry. A moderate vacuum level at 15inHg is suggested for unilateral transtibial amputees with elevated vacuum suspension. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Effect of programmed circadian temperature fluctuations on ...

    African Journals Online (AJOL)

    Effect of programmed circadian temperature fluctuations on population dynamics of. Biomphalaria pfeifferi (Krauss). K.N. de Kock and J.A. van Eeden. Snail Research Unit, Medical Research Council, Potchefstroom University for Christian Higher Education,. Potchefstroom. Until now all life-table studies on freshwater snails.

  1. Quantum random number generator based on quantum nature of vacuum fluctuations (United States)

    Ivanova, A. E.; Chivilikhin, S. A.; Gleim, A. V.


    Quantum random number generator (QRNG) allows obtaining true random bit sequences. In QRNG based on quantum nature of vacuum, optical beam splitter with two inputs and two outputs is normally used. We compare mathematical descriptions of spatial beam splitter and fiber Y-splitter in the quantum model for QRNG, based on homodyne detection. These descriptions were identical, that allows to use fiber Y-splitters in practical QRNG schemes, simplifying the setup. Also we receive relations between the input radiation and the resulting differential current in homodyne detector. We experimentally demonstrate possibility of true random bits generation by using QRNG based on homodyne detection with Y-splitter.

  2. Multiphysics coupling between periodic gear mesh excitation and input/output fluctuating torques: Application to a roots vacuum pump (United States)

    Garambois, Pierre; Donnard, Guillaume; Rigaud, Emmanuel; Perret-Liaudet, Joël


    This paper presents the analysis of multiphysics coupling between periodic gear mesh excitation and upstream/downstream fluctuating loads using an iterative spectral methodology. This one is based on the resolution of the parametric equations of motion in the spectral domain. Its efficiency makes possible to treat both low and high frequency excitations for systems having a large number of degrees-of-freedom. The different excitation sources, the dynamic coupled equations of motion, the spectral methodology and the iterative resolution principle are described. The dynamic responses of a roots vacuum pump for which the spur gear high mesh frequency parametric excitation is coupled with a low fluidic drag torque frequency. The coupling between excitations generates a frequency enrichment of the dynamic response which is reflected on waterfall plots by emergence of numerous sidebands around harmonics of the mesh frequency.

  3. Vacuum level effects on knee contact force for unilateral transtibial amputees with elevated vacuum suspension. (United States)

    Xu, Hang; Greenland, Kasey; Bloswick, Donald; Zhao, Jie; Merryweather, Andrew


    The elevated vacuum suspension system (EVSS) has demonstrated unique health benefits for amputees, but the effect of vacuum pressure values on knee contact force (KCF) is still unclear. The objective of this study was to investigate the effect of vacuum levels on KCF for unilateral transtibial amputees (UTA) using the EVSS. Three-dimensional gait was modeled for 9 UTA with five vacuum levels (0-20inHg [67.73kPa], 5inHg [16.93kPa] increments) and 9 non-amputees based on kinematic and ground reaction force data. The results showed that the vacuum level effects were significant for peak axial KCF, which had a relatively large value at 0 and 20inHg (67.73kPa). The intact limb exhibited a comparable peak axial KCF to the non-amputees at 15inHg (50.79kPa). At moderate vacuum levels (5inHg [16.93kPa] to 15inHg [50.79kPa]), co-contraction of quadriceps and hamstrings at peak axial KCF was similar for the intact limb, but was smaller for the residual limb comparing with the non-amputees. The intact limb showed a similar magnitude of quadriceps and hamstrings force at 15inHg (50.79kPa) to the non-amputees, but the muscle coordination patterns varied between the residual and intact limbs. These findings indicate that a proper vacuum level may partially compensate for the lack of ankle plantarflexor and reduce the knee loading. Of the tested vacuum levels, 15inHg (50.79kPa) appears most favorable, although additional analyses with more amputees are suggested to confirm these results prior to establishing clinical guidelines. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Effective cosmological constant induced by stochastic fluctuations of Newton's constant

    Energy Technology Data Exchange (ETDEWEB)

    Cesare, Marco de, E-mail: [Department of Physics, King' s College London, University of London, London (United Kingdom); Lizzi, Fedele, E-mail: [Dipartimento di Fisica “E. Pancini”, Università di Napoli “Federico II”, Napoli (Italy); INFN, Sezione di Napoli (Italy); Departament de Estructura i Constituents de la Matèria, Institut de Ciéncies del Cosmos, Universitat de Barcelona (Spain); Sakellariadou, Mairi, E-mail: [Department of Physics, King' s College London, University of London, London (United Kingdom)


    We consider implications of the microscopic dynamics of spacetime for the evolution of cosmological models. We argue that quantum geometry effects may lead to stochastic fluctuations of the gravitational constant, which is thus considered as a macroscopic effective dynamical quantity. Consistency with Riemannian geometry entails the presence of a time-dependent dark energy term in the modified field equations, which can be expressed in terms of the dynamical gravitational constant. We suggest that the late-time accelerated expansion of the Universe may be ascribed to quantum fluctuations in the geometry of spacetime rather than the vacuum energy from the matter sector.

  5. Effect of thermal fluctuations on a charged dilatonic black Saturn

    Directory of Open Access Journals (Sweden)

    Behnam Pourhassan


    Full Text Available In this paper, we will analyze the effect of thermal fluctuations on the thermodynamics of a charged dilatonic black Saturn. These thermal fluctuations will correct the thermodynamics of the charged dilatonic black Saturn. We will analyze the corrections to the thermodynamics of this system by first relating the fluctuations in the entropy to the fluctuations in the energy. Then, we will use the relation between entropy and a conformal field theory to analyze the fluctuations in the entropy. We will demonstrate that similar physical results are obtained from both these approaches. We will also study the effect of thermal fluctuations on the phase transition in this charged dilatonic black Saturn.

  6. Effect of thermal fluctuations on a charged dilatonic black Saturn

    Energy Technology Data Exchange (ETDEWEB)

    Pourhassan, Behnam, E-mail: [School of Physics, Damghan University, Damghan (Iran, Islamic Republic of); Faizal, Mir, E-mail: [Department of Physics and Astronomy, University of Lethbridge, Lethbridge, AB T1K 3M4 (Canada)


    In this paper, we will analyze the effect of thermal fluctuations on the thermodynamics of a charged dilatonic black Saturn. These thermal fluctuations will correct the thermodynamics of the charged dilatonic black Saturn. We will analyze the corrections to the thermodynamics of this system by first relating the fluctuations in the entropy to the fluctuations in the energy. Then, we will use the relation between entropy and a conformal field theory to analyze the fluctuations in the entropy. We will demonstrate that similar physical results are obtained from both these approaches. We will also study the effect of thermal fluctuations on the phase transition in this charged dilatonic black Saturn.

  7. Effect of Thermal Fluctuations on a Charged Dilatonic Black Saturn

    CERN Document Server

    Pourhassan, Behnam


    In this paper, we will analyze the effect of thermal fluctuations on the thermodynamics of a charged dilatonic black Saturn. These thermal fluctuations will correct the thermodynamics of the charged dilatonic black Saturn. We will analyze the corrections to the thermodynamics of this system by first relating the fluctuations in the entropy to the fluctuations in the energy. Then, we will use the relation between entropy and a conformal field theory to analyze the fluctuations in the entropy. We will demonstrate that similar physical results are obtained from both these approaches. We will also study the effect of thermal fluctuations on the phase transition in this charged dilatonic black Saturn.

  8. Effect of electropolishing on vacuum furnace design

    Directory of Open Access Journals (Sweden)

    Sutanwi Lahiri


    Full Text Available The use of thermal shields of materials having low emissivity in vacuum furnaces is well-known. However, the surface condition of the heat shields is one of the most important factors governing their efficiency as radiation resistances. The emissivity of the thermal shields dictates the power rating of the heaters in furnace design. The unpolished materials used in the heater tests showed poor performance leading to loss of a signi­ficant percentage of the input power. The present work deals with the refur­bishment of the radiation heat shields used in a furnace for heating graphite structure. The effect of refurbishment of the heat shields by the buffing and subsequently electro­polishing was found to improve the performance of the shields as heat reflectors. The com­position of the electrolyte was chosen in such a way that the large shields of Mo, Inconel and SS can be polished using the same reagents in different ratios. The present work deals with the development of a standard electropolishing procedure for large metallic sheets and subsequently qualifying them by roughness and emissivity measure­ments. The improvement noted in the shielding efficiency of the furnace in the subsequent runs is also discussed here.

  9. The cost-effectiveness of introducing manual vacuum aspiration ...

    African Journals Online (AJOL)

    The cost-effectiveness of introducing manual vacuum aspiration compared with dilatation and curettage for incomplete firsttrimester miscarriages at a tertiary hospital in Manzini, Swaziland. C Maonei, J Miot, S Moodley ...

  10. Electromechanical Performance of NEMS Actuator Fabricated from Nanowire under quantum vacuum fluctuations using GDQ and MVIM

    Directory of Open Access Journals (Sweden)

    Fateme Abadian


    Full Text Available The Casimir attraction can significantly interfere the physical response of nanoactuators. The intensity of the Casimir force depends on the geometries of interacting bodies. The present paper is dedicated to model the influence of the Casimir attraction on the electrostatic stability of nanoactuators made of cylindrical conductive nanowire/nanotube. An asymptotic solution, based on path-integral approach, is employed to consider the Casimir force. The continuum theory is employed to derive the constitutive equation of the actuator. The governing nonlinear equations are solved by three different approaches. Various perspectives of the issue including comparison with the van der Waals (vdW force regime, the variation of instability parameters and effect of geometry are addressed.

  11. The effect of vacuum devices on penile hemodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Katz, P.G.; Haden, H.T.; Mulligan, T.; Zasler, N.D. (Medical College of Virginia, Richmond (USA))


    External vacuum devices are being used increasingly for the management of erectile dysfunction. There is limited information regarding the effect of vacuum devices on penile blood flow and potential for ischemic penile injury. The penile xenon washout rate was measured before and after application of 2 vacuum systems in 15 subjects. Compared to flaccid state measurements the xenon washout rate did not change significantly with the Synergist Erection System but it was significantly reduced with the Osbon ErecAid System. However, the degree and duration of decrease in penile blood flow that may result in ischemic changes are unknown.

  12. Effect of increased vacuum and aspiration rates on phacoemulsification efficiency. (United States)

    Gupta, Isha; Cahoon, Judd M; Gardiner, Gareth; Garff, Kevin; Henriksen, Bradley S; Pettey, Jeff H; Barlow, William R; Olson, Randall J


    To evaluate the effect of vacuum and aspiration rates on phacoemulsification efficiency. John A. Moran Eye Center Laboratories, University of Utah, Salt Lake City, Utah, USA. Experimental study. Formalin-soaked porcine lenses were divided into 2.0 mm cubes, and 0.9 mm 30-degree beveled 20-degree bent tips were used with micropulse ultrasound (US) (6 milliseconds on and 6 milliseconds off) and a peristaltic flow system. Vacuum levels were tested at 200, 300, 400, and 500 mm Hg, and aspiration rates were tested at 20, 35, and 50 mL/min. Efficiency (time to lens removal) and chatter (number of lens fragment repulsions from the tip) were determined. Increasing vacuum increased efficiency only when going from 200 mm Hg to higher vacuum levels. Increasing aspiration increased efficiency at all points measured (25 mL/min versus 35 mL/min, P vacuum was increased from 200 mm Hg to 300 mm Hg and up. Chatter decreased with increasing flow. Vacuum improved efficiency only up to 300 mm Hg and was more dependent on increasing flow. Similarly, chatter correlated with 200 mm Hg vacuum only and was more correlated with flow. Limitations of this study include use of only 1 US power modulation and hard nuclear material. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  13. The correlation between the Nernst effect and fluctuation diamagnetism in strongly fluctuating superconductors (United States)

    Sarkar, Kingshuk; Banerjee, Sumilan; Mukerjee, Subroto; Ramakrishnan, T. V.


    We study the Nernst effect in fluctuating superconductors by calculating the transport coefficient {α }{xy} in a phenomenological model where the relative importance of phase and amplitude fluctuations of the order parameter is tuned continuously to smoothly evolve from an effective XY model to the more conventional Ginzburg-Landau description. To connect with a concrete experimental realization we choose the model parameters appropriate for cuprate superconductors and calculate {α }{xy} and the magnetization {M} over the entire range of experimentally accessible values of field, temperature and doping. We argue that {α }{xy} and {M} are both determined by the equilibrium properties of the superconducting fluctuations (and not their dynamics) despite the former being a transport quantity. Thus, the experimentally observed correlation between the Nernst signal and the magnetization arises primarily from the correlation between {α }{xy} and {M}. Further, there exists a dimensionless ratio {M}/(T{α }{xy}) that quantifies this correlation. We calculate, for the first time, this ratio over the entire phase diagram of the cuprates and find it agrees with previous results obtained in specific parts of the phase diagram. We conclude that there appears to be no sharp distinction between the regimes dominated by phase fluctuations and Gaussian fluctuations for this ratio in contrast to {α }{xy} and {M} individually. The utility of this ratio is that it can be used to determine the extent to which superconducting fluctuations contribute to the Nernst effect in different parts of the phase diagram given the measured values of magnetization.

  14. Van der Waals and resonance interactions between accelerated atoms in vacuum and the Unruh effect (United States)

    Lattuca, M.; Marino, J.; Noto, A.; Passante, R.; Rizzuto, L.; Spagnolo, S.; Zhou, W.


    We discuss different physical effects related to the uniform acceleration of atoms in vacuum, in the framework of quantum electrodynamics. We first investigate the van der Waals/Casimir-Polder dispersion and resonance interactions between two uniformly accelerated atoms in vacuum. We show that the atomic acceleration significantly affects the van der Waals force, yielding a different scaling of the interaction with the interatomic distance and an explicit time dependence of the interaction energy. We argue how these results could allow for an indirect detection of the Unruh effect through dispersion interactions between atoms. We then consider the resonance interaction between two accelerated atoms, prepared in a correlated Bell-type state, and interacting with the electromagnetic field in the vacuum state, separating vacuum fluctuations and radiation reaction contributions, both in the free-space and in the presence of a perfectly reflecting plate. We show that nonthermal effects of acceleration manifest in the resonance interaction, yielding a change of the distance dependence of the resonance interaction energy. This suggests that the equivalence between temperature and acceleration does not apply to all radiative properties of accelerated atoms. To further explore this aspect, we evaluate the resonance interaction between two atoms in non inertial motion in the coaccelerated (Rindler) frame and show that in this case the assumption of an Unruh temperature for the field is not required for a complete equivalence of locally inertial and coaccelerated points of views.

  15. Equilibrium & Nonequilibrium Fluctuation Effects in Biopolymer Networks (United States)

    Kachan, Devin Michael

    speculate that cells take advantage of this equilibrium effect by tuning near the transition point, where small changes in free cross-linker density will affect large structural rearrangements between free filament networks and networks of bundles. Cells are naturally found far from equilibrium, where the active influx of energy from ATP consumption controls the dynamics. Motor proteins actively generate forces within biopolymer networks, and one may ask how these differ from the random stresses characteristic of equilibrium fluctuations. Besides the trivial observation that the magnitude is independent of temperature, I find that the processive nature of the motors creates a temporally correlated, or colored, noise spectrum. I model the network with a nonlinear scalar elastic theory in the presence of active driving, and study the long distance and large scale properties of the system with renormalization group techniques. I find that there is a new critical point associated with diverging correlation time, and that the colored noise produces novel frequency dependence in the renormalized transport coefficients. Finally, I study marginally elastic solids which have vanishing shear modulus due to the presence of soft modes, modes with zero deformation cost. Although network coordination is a useful metric for determining the mechanical response of random spring networks in mechanical equilibrium, it is insufficient for describing networks under external stress. In particular, under-constrained networks which are fluid-like at zero load will dynamically stiffen at a critical strain, as observed in numerical simulations and experimentally in many biopolymer networks. Drawing upon analogies to the stress induced unjamming of emulsions, I develop a kinetic theory to explain the rigidity transition in spring and filament networks. Describing the dynamic evolution of non-affine deformation via a simple mechanistic picture, I recover the emergent nonlinear strain

  16. Effect of directional selection for body size on fluctuating asymmetry ...

    Indian Academy of Sciences (India)


    and its relationship with stress. [Vishalakshi C and Singh B N 2009 Effect of directional selection for body size on fluctuating asymmetry in certain morphological traits in. Drosophila ananassae; J. Biosci. 34 275–285]. Keywords. Body size; directional selection; Drosophila ananassae; fluctuating asymmetry; hybridisation; ...

  17. Effect of a fluctuating parameter mismatch and the associated time ...

    Indian Academy of Sciences (India)

    Abstract. We study the effect of parameter fluctuations and the resultant multiplicative noise on the synchronization of coupled chaotic systems. We introduce a new quantity, the fluctuation rate φ as the number of perturbations occurring to the parameter in unit time. It is shown that φ is the most significant quantity that ...

  18. The effect of primordial fluctuations on neutrino oscillations

    CERN Document Server

    Harries, N P


    Recent work has shown that neutrino oscillations in matter can be greatly enhanced by flips between mass eigenstates if the medium is fluctuating with a period equal to the neutrino oscillation length. Here we investigate the effect of the primordial fluctuations on the neutrino oscillations in the early universe. We calculate the oscillation probability in the case of a general power law fluctuation spectrum and for a more realistic spectrum predicted by inflation. We also include the effect of the amplification of fluctuations resulting from the QCD phase transition. We find that there is a region of parameter space where this mechanism would be the dominant mechanism for producing sterile neutrinos. However this conclusion does not take account of the damping of fluctuations on the neutrino oscillation scale when the neutrinos decouple from the plasma. We find that this reduces the probability of flips between the mass eigenstates to an unobservable level.

  19. Effectiveness of manual vacuum aspiration (MVA) in the ...

    African Journals Online (AJOL)

    Effectiveness of manual vacuum aspiration (MVA) in the management of first trimester miscarriage: Experience in a specialist centre in North-Eastern Nigeria. ... period, out of which 251 were MVA procedures performed for various first trimester miscarriages, accounting for 13.2 % of the total gynaecological admissions.

  20. Effect of altering local protein fluctuations using artificial intelligence (United States)

    Nishiyama, Katsuhiko


    The fluctuations in Arg111, a significantly fluctuating residue in cathepsin K, were locally regulated by modifying Arg111 to Gly111. The binding properties of 15 dipeptides in the modified protein were analyzed by molecular simulations, and modeled as decision trees using artificial intelligence. The decision tree of the modified protein significantly differed from that of unmodified cathepsin K, and the Arg-to-Gly modification exerted a remarkable effect on the peptide binding properties. By locally regulating the fluctuations of a protein, we may greatly alter the original functions of the protein, enabling novel applications in several fields.

  1. The effect of vacuum operator's experience on Apgar scores. (United States)

    Wirapornsawan, Umawan; Suwanrath, Chitkasaem; Pinjaroen, Sutham


    To determine the effect of a vacuum operator's experience on Apgar scores. A historical cohort study was conducted. All women who delivered by vacuum extraction between January 2003 and December 2007 at Songklanagarind Hospital were recruited. Vacuum operators were divided into two groups: staff doctors and residents. Comparisons of Apgar scores and rates of low Apgar scores (≤7) between the two groups were studied. A multivariate logistic regression analysis was used to control confounding variables for low Apgar scores. The percentages for the procedure performed by the staff doctors and residents were 76.9 and 23.1%. At 1 min, the rates of low Apgar scores in the staff and resident groups were 6.7 and 24.1% (pApgar scores were 0.6 and 5.2% (pApgar scores. The residents had a 2.9-fold increased risk of low Apgar scores at 1 min compared with the staff doctors (adjusted odds ratio 2.9; 95% confidence interval 1.7-6.8). In the resident group, the third year residents had the lowest risk of low Apgar scores. The vacuum operator's experience was an independent risk factor for low Apgar scores. Improvement of the residency training program is mandatory.

  2. Effect of flow fluctuations and nonflow on elliptic flow methods

    Energy Technology Data Exchange (ETDEWEB)

    Ollitrault, Jean-Yves; Poskanzer, Arthur M.; Voloshin, Sergei A.


    We discuss how the different estimates of elliptic flow are influenced by flow fluctuations and nonflow effects. It is explained why the event-plane method yields estimates between the two-particle correlation methods and the multiparticle correlation methods. It is argued that nonflow effects and fluctuations cannot be disentangled without other assumptions. However, we provide equations where, with reasonable assumptions about fluctuations and nonflow, all measured values of elliptic flow converge to a unique mean v_2,PP elliptic flow in the participant plane and, with a Gaussian assumption on eccentricity fluctuations, can be converted to the mean v_2,RP in the reaction plane. Thus, the 20percent spread in observed elliptic flow measurements from different analysis methods is no longer mysterious.

  3. Effects of phase transition induced density fluctuations on pulsar dynamics

    Directory of Open Access Journals (Sweden)

    Partha Bagchi


    Full Text Available We show that density fluctuations during phase transitions in pulsar cores may have non-trivial effects on pulsar timings, and may also possibly account for glitches and anti-glitches. These density fluctuations invariably lead to non-zero off-diagonal components of the moment of inertia, leading to transient wobbling of star. Thus, accurate measurements of pulsar timing and intensity modulations (from wobbling may be used to identify the specific pattern of density fluctuations, hence the particular phase transition, occurring inside the pulsar core. Changes in quadrupole moment from rapidly evolving density fluctuations during the transition, with very short time scales, may provide a new source for gravitational waves.

  4. The effects of vacuum polarization on thermonuclear reaction rates (United States)

    Gould, Robert J.


    Added to the pure Coulomb potential, the contribution from vacuum polarization increases the barrier, reducing the wave function (u) for reacting nuclei within the range of nuclear forces. The cross section and reaction rate are then reduced accordingly by a factor proportional to u squared. The effect is treated by evaluating the vacuum polarization potential as a small correction to the Coulomb term, then computing u in a WKB formulation. The calculation is done analytically employing the small r power-series expansion for the Uehling potential to express the final result in terms of convenient parameters. At a temperature of 1.4 x 10 to the 7th K the (negative) correction is 1.3 percent for the fundamental fusion process p + p yields d + e(+) + nu.

  5. Quantum fluctuation effects on nuclear fragment and atomic cluster formation

    Energy Technology Data Exchange (ETDEWEB)

    Ohnishi, Akira [Hokkaido Univ., Sapporo (Japan). Dept. of Physics; Randrup, J.


    We investigate the nuclear fragmentation and atomic cluster formation by means of the recently proposed quantal Langevin treatment. It is shown that the effect of the quantal fluctuation is in the opposite direction in nuclear fragment and atomic cluster size distribution. This tendency is understood through the effective classical temperature for the observables. (author)

  6. The vacuum cleaner effect in minimally invasive percutaneous nephrolitholapaxy. (United States)

    Nicklas, André P; Schilling, David; Bader, Markus J; Herrmann, Thomas R W; Nagele, Udo


    Percutaneous stone removal increasingly plays an important role among the different approaches of interventional stone therapy, particularly since the development of miniaturized instruments is resulting in lower morbidity for the patients. One major drawback of smaller instruments is the increased difficulty of stone retrieval after disintegration due to the reduced tract diameter. This results in longer operation time and the need of additional tools such as disposable retrieval baskets. One of the key factors in the development of minimally invasive percutaneous nephrolitholapaxy (MIP) was the design of an Amplatz sheath which provides a built-in vacuum cleaner effect for stone retrieval. A series of flow analyses with the gauges and shapes of the most commonly used nephroscopes and sheaths in percutaneous nephrolitholapaxy was performed by computational fluid dynamics. Flow velocity and direction in front of the nephroscope were computed and visualized by the software. In our study, the vacuum cleaner effect developed exclusively when a round-shaped nephroscope was used (Nagele Miniature Nephroscope System, Karl Storz GmbH & Co. KG) and depended on the relation between nephroscope diameter and inner sheath diameter. The strongest effect was observed with a 12 F nephroscope and an inner sheath diameter of 15 F. It did not develop when an oval- or crescent-shaped nephroscope was used. In front of the distal end of the round-shaped nephroscope, a slipstream develops, induced by the excursive change of width of the fluid flow on the outlet of the flushing canal. This allows the adhesion of a stone fragment in the eddy while the fluid flow is circulating around the stone. This study illustrates and explains the vacuum cleaner effect which has been detected in the development of the Nagele Miniature Nephroscope System used in MIP. It combines the reduced morbidity of smaller kidney puncture diameters with the benefit of quick and complete stone removal.

  7. Nernst effect and diamagnetism in phase fluctuating superconductors. (United States)

    Podolsky, Daniel; Raghu, Srinivas; Vishwanath, Ashvin


    We study superconducting systems in the regime where superconductivity is destroyed by phase fluctuations. We find that the Nernst effect has a much sharper temperature decay than predicted by Gaussian fluctuations, with an onset temperature that tracks Tc rather than the pairing temperature. We find a close quantitative connection with diamagnetism--the ratio of magnetization to transverse thermoelectric conductivity reaches a fixed value at high temperatures. We interpret measurements on underdoped cuprates in terms of a dilute vortex liquid over a wide temperature range above Tc.

  8. Correction of Dopant Concentration Fluctuation Effects in Silicon Drift Detectors

    CERN Document Server

    Nouais, D; Bonvicini, V; Cerello, P G; Crescio, E; Giubellino, P; Hernández-Montoya, R; Kolojvari, A A; Montaño-Zetina, L M; Nilsen, B S; Piemonte, C; Rachevsky, A; Tosello, F; Vacchi, A; Wheadon, R


    Dopant fluctuations in silicon wafers are responsible for systematic errors in the determination of the particle crossing point in silicon drift detectors. In this paper, we report on the first large scale measurement of this effect by means of a particle beam. A significant improvement of the anodic resolution has been obtained by correcting for these systematic deviations.

  9. Stochastic emergence of inflaton fluctuations in a SdS primordial universe with large-scale repulsive gravity from a 5D vacuum


    Reyes, Luz Marina; Aguilar, Jose Edgar Madriz; Bellini, Mauricio


    We develop a stochastic approach to study scalar field fluctuations of the inflaton field in an early inflationary universe with a black-hole (BH), which is described by an effective 4D SdS metric. Considering a 5D Ricci-flat SdS static metric, we implement a planar coordinate transformation, in order to obtain a 5D cosmological metric, from which the effective 4D SdS metric can be induced on a 4D hypersurface. We found that at the end of inflation, the squared fluctuations of the inflaton fi...

  10. Thermal-vacuum effects on polymer matrix composite materials (United States)

    Tennyson, R. C.; Mabson, G. E.


    Results are presented on the thermal-vacuum response of a variety of fiber reinforced polymers matrix composites that comprised the UTIAS experiment on the LDEF satellite. Theoretical temperature-time predictions for this experiment are in excellent agreement with test data. Results also show quite clearly the effect of outgassing in the dimensional changes of these materials and the corresponding coefficients of thermal expansion. Finally, comparison with ground-based simulation tests are presented as well. Use of these data for design purposes are also given.

  11. Invariant vacuum (United States)

    Robles-Pérez, Salvador


    We apply the Lewis-Riesenfeld invariant method for the harmonic oscillator with time dependent mass and frequency to the modes of a charged scalar field that propagates in a curved, homogeneous and isotropic spacetime. We recover the Bunch-Davies vacuum in the case of a flat DeSitter spacetime, the equivalent one in the case of a closed DeSitter spacetime and the invariant vacuum in a curved spacetime that evolves adiabatically. In the three cases, it is computed the thermodynamical magnitudes of entanglement between the modes of the particles and antiparticles of the invariant vacuum, and the modification of the Friedmann equation caused by the existence of the energy density of entanglement. The amplitude of the vacuum fluctuations are also computed.

  12. Real gas effects on receptivity to kinetic fluctuations (United States)

    Tumin, Anatoli; Edwards, Luke


    Receptivity of high-speed boundary layers is considered within the framework of fluctuating hydrodynamics where stochastic forcing is introduced through fluctuating shear stress and heat flux stemming from kinetic fluctuations (thermal noise). The forcing generates unstable modes whose amplification downstream and may lead to transition. An example of high-enthalpy (16 . 53 MJ / kg) boundary layer at relatively low wall temperatures (Tw = 1000 K - 3000 K), free stream temperature (Te = 834 K), and low pressure (0 . 0433 atm) is considered. Dissociation at the chosen flow parameters is still insignificant. The stability and receptivity analyses are carried out using a solver for calorically perfect gas with effective Prandtl number and specific heats ratio. The receptivity phenomenon is unchanged by the inclusion of real gas effects in the mean flow profiles. This is attributed to the fact that the mechanism for receptivity to kinetic fluctuations is localized near the upper edge of the boundary layer. Amplitudes of the generated wave packets are larger downstream in the case including real gas effects. It was found that spectra in both cases include supersonic second Mack unstable modes despite the temperature ratio Tw /Te > 1 . Supported by AFOSR.

  13. Mitigation of Radiation and EMI Effects on the Vacuum Control System of LHC

    CERN Document Server

    Pigny, G; Krakowski, P; Rio, B


    The 26 km of vacuum chambers where circulates the beam of the Large Hadron Collider (LHC) must be maintained under Ultra High Vacuum (UHV) to minimize the beam interactions with residual gases, and allow the operation of specific systems. The vacuum level is measured by several thousands of gauges along the accelerator. Bad vacuum quality may trigger a beam dump and close the associated sector valves. The effects of radiation or Electromagnetic Interferences (EMI) on components that may stop the machine must be evaluated and minimized. We report on the actions implemented to mitigate their impact on the vacuum control system.

  14. Effect of catalyst deactivation on vacuum residue hydrocracking

    Directory of Open Access Journals (Sweden)

    Hoda S. Ahmed


    Full Text Available Accelerated deactivation tests of the pre-sulfided Mo–W/SiO2–Al2O3 commercial catalyst were performed using heavy vacuum petroleum feedstock. High reaction temperature employed in the accelerated catalyst aging resulted in large amounts of carbonaceous deposition with high aromaticity, which was found to be the principal deactivation cause. The effect of catalyst deactivation on hydrocracking of vacuum residue was studied. Experiments were carried out in a batch reactor at 60 bar, feed to catalyst ratio 10:1 and temperature 425 °C. The duration time for a cycle-run was 4 h. On increasing the interval duration times from 4 to 20 h (i.e. five cycles, the quality of the hydrocracked products was decreased. In each cycle-run, a fresh feedstock was used with the same sulfide catalyst. The quality of distillate products, such as hydrodesulfurization (HDS was decreased from 61.50% to 39.52%, while asphaltene contents of the total liquid product were increased from 2.7% to 5.2% and their boiling ranges were increased during these duration times due to the successive catalyst deactivation during the 5 cycle-runs, caused by successive adsorption of coke formation.

  15. Effects of quantum fluctuations of metric on the universe (United States)

    Yang, Rongjia


    We consider a model of modified gravity from the nonperturbative quantization of a metric. We obtain the modified gravitational field equations and the modified conservational equations. We apply it to the FLRW spacetime and find that due to the quantum fluctuations a bounce universe can be obtained and a decelerated expansion can also possibly be obtained in a dark energy dominated epoch. We also discuss the effects of quantum fluctuations on inflation parameters (such as slow-roll parameters, spectral index, and the spectrum of the primordial curvature perturbation) and find values of parameters in the comparing the predictions of inflation can also work to drive the current epoch of acceleration. We obtain the constraints on the parameter of the theory from the observation of the big bang nucleosynthesis.

  16. Nonlinear dynamical effects on reaction rates in thermally fluctuating environments. (United States)

    Kawai, Shinnosuke; Komatsuzaki, Tamiki


    A framework to calculate the rate constants of condensed phase chemical reactions of manybody systems is presented without relying on the concept of transition state. The theory is based on a framework we developed recently adopting a multidimensional underdamped Langevin equation in the region of a rank-one saddle. The theory provides a reaction coordinate expressed as an analytical nonlinear functional of the position coordinates and velocities of the system (solute), the friction constants, and the random force of the environment (solvent). Up to moderately high temperature, the sign of the reaction coordinate can determine the final destination of the reaction in a thermally fluctuating media, irrespective of what values the other (nonreactive) coordinates may take. In this paper, it is shown that the reaction probability is analytically derived as the probability of the reaction coordinate being positive, and that the integration with the Boltzmann distribution of the initial conditions leads to the exact reaction rate constant when the local equilibrium holds and the quantum effect is negligible. Because of analytical nature of the theory taking into account all nonlinear effects and their combination with fluctuation and dissipation, the theory naturally provides us with the firm mathematical foundation of the origin of the reactivity of the reaction in a fluctuating media.

  17. Investigation of the effects of capacity on asbestos vacuum cleaners. (United States)

    Johnston, W L; Loflin, W J


    Nine industrial vacuum cleaners, designed for collection of asbestos waste, were tested to determine how the performance was affected when the manufacturer's specified capacity was approached, attained, and exceeded. This determination was assessed by measurement of the airborne asbestos fiber concentration in the vacuum cleaner discharge air and the change in vacuum cleaner suction pressure. Airborne fiber concentrations were found to be far below the present OSHA standard; however, the suction pressure of each vacuum cleaner dropped considerably as the capacity was approached and/or exceeded. All of the units tested except one were able to contain 25% more than their specified capacity without any internal problems, filtering system failure, or total loss of suction pressure.

  18. Effects of the quantum vacuum in particle physics and cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, Juri


    In this work we investigate numerous effects of virtual particles on processes relevant for particle physics and cosmology. A central question is, whether radiative spontaneous electroweak symmetry breaking can be combined with neutrino mass generation, we find that the answer is affirmative. We discuss the implication of the RSSB on the neutrino mass phenomenology and low-energy observables. Furthermore, by comparing the models to experimental data we find that several anomalies in the present observations favour particular scenarios over the pure Standard Model hypothesis. We are able to show, that the presence of sterile neutrinos with active-sterile mixing of order 10{sup -3} and masses in the TeV range leads to a reduced invisible decay width of the Z-boson and can bring the NuTeV observations in agreement with theoretical expectations. The models we discuss naturally incorporate long lived particles which can serve as dark matter candidates and we investigate this phenomenologically. We find that the combination of the requirements leads to interesting constraints on the model and parameter space. We find that loop induced electromagnetic moments for the neutral dark matter candidates, lead to interactions with charged particles. We use this and derive new constraints from existing XENON100 and LUX data. In addition we study how vacuum effects can backreact on a given geometry in electromagnetism and semiclassical gravity. We find that in the case of gravity the conformal set up plays a special role and indicate several ideas for further investigation of this topic.

  19. Vacuum Technology

    Energy Technology Data Exchange (ETDEWEB)

    Biltoft, P J


    The environmental condition called vacuum is created any time the pressure of a gas is reduced compared to atmospheric pressure. On earth we typically create a vacuum by connecting a pump capable of moving gas to a relatively leak free vessel. Through operation of the gas pump the number of gas molecules per unit volume is decreased within the vessel. As soon as one creates a vacuum natural forces (in this case entropy) work to restore equilibrium pressure; the practical effect of this is that gas molecules attempt to enter the evacuated space by any means possible. It is useful to think of vacuum in terms of a gas at a pressure below atmospheric pressure. In even the best vacuum vessels ever created there are approximately 3,500,000 molecules of gas per cubic meter of volume remaining inside the vessel. The lowest pressure environment known is in interstellar space where there are approximately four molecules of gas per cubic meter. Researchers are currently developing vacuum technology components (pumps, gauges, valves, etc.) using micro electro mechanical systems (MEMS) technology. Miniature vacuum components and systems will open the possibility for significant savings in energy cost and will open the doors to advances in electronics, manufacturing and semiconductor fabrication. In conclusion, an understanding of the basic principles of vacuum technology as presented in this summary is essential for the successful execution of all projects that involve vacuum technology. Using the principles described above, a practitioner of vacuum technology can design a vacuum system that will achieve the project requirements.

  20. Mechanisms governing the effects of vacuum-assisted closure in cardiac surgery. (United States)

    Malmsjö, Malin; Ingemansson, Richard; Sjögren, Johan


    : Vacuum-assisted closure has been adopted as the first-line treatment for poststernotomy mediastinitis as a result of the excellent clinical outcome achieved with its use. Scientific evidence regarding the mechanisms by which vacuum-assisted closure promotes wound healing has started to emerge, although knowledge regarding the effects on heart and lung function is still limited. The organs in the mediastinum are hemodynamically crucial, and in patients with poststernotomy mediastinitis, vulnerable bypass grafts and reduced cardiac function must be taken into consideration during vacuum-assisted closure therapy. This article provides an overview of the effects of vacuum-assisted closure on heart and lung function and summarizes the current knowledge on the mechanisms by which vacuum-assisted closure therapy promotes wound healing.

  1. A theology of matter. The strong interaction at strong resonance at the meeting point of I and not-I. Conjectures about oscillating strings and fluctuating vacuum energy; Eine Theologie der Materie. Die starke Wechselwirkung bei starker Resonanz am Begegnungs-Ort von Ich und Nicht-Ich. Mutmassungen ueber oszillierende Strings und fluktuierende Vakuum-Energie

    Energy Technology Data Exchange (ETDEWEB)

    Boes, Roderick H.


    This book shows that matter and consciousness are intertwined and mutually produce. Quantum vacuum fluctuations ensure that the latent energy of each event is present as zero-point energy simultaneously at all points of the cosmos.

  2. Symmetry and dynamics of FHF-anion in vacuum, in CD2Cl2and in CCl4. Ab initio MD study of fluctuating solvent-solute hydrogen and halogen bonds. (United States)

    Pylaeva, S A; Elgabarty, H; Sebastiani, D; Tolstoy, P M


    FHF - anion is a classic example of a central-symmetric strongly hydrogen bonded system that has been intensively investigated both experimentally and theoretically. In this paper we focus on solvent effects on symmetry, structure and dynamics of the anion. The FHF - anion is studied in vacuum, dissolved in CH 2 Cl 2 and dissolved in CCl 4 by ab initio molecular dynamics simulations. We show that CH 2 Cl 2 molecules form CHF hydrogen bonds with lone pairs of fluorine atoms, while CCl 4 molecules form halogen bonds. These specific non-covalent solvent-solute interactions are cooperatively coupled to the FHF - hydrogen bonds. The fluctuation of solvent molecules' positions is the driving force changing the FHF - hydrogen bond geometry. Most of the time, the anion is solvated asymmetrically, which leads to the asymmetric bridging particle position, though the time-averaged D ∞h symmetry is retained. Interestingly, this transient asymmetrization of FHF - is more pronounced in CCl 4 , than in CH 2 Cl 2 . We show that the 1 H and 19 F NMR chemicals shifts react sensitively to the changes of anion's geometry and the limiting chemical shifts of free solvated FH and F - are strongly solvent-dependent.

  3. An Effective Approach to Flash Vacuum Thermolytic Studies

    DEFF Research Database (Denmark)

    Carlsen, Lars; Egsgaard, Helge


    Flash vacuum thermolysis in combination with field ionization mass spectrometry, supplementary with collision activated spectra of the single field ionized molecules, is shown to be a facile and highly informative method for studying even very complex mixtures of primarily formed products...

  4. The vacuum window - a minimal concept with maximum effect

    Energy Technology Data Exchange (ETDEWEB)

    Bredsdorff, M.; Moltke, I.; Bezzel, E.


    The projects primary aim was to develop a production technology in order to produce evacuated panes at a competitive price. Insulating using vacuum is not a new concept. It has been described in patents for over a century. The field of usage of this concept is immense, and the potentials even greater. The general principle of the vacuum window is to have nothing, namely vacuum, in-between two low radiant surfaces, thus obtaining very low heat transmission technique for highly insulating evacuated windows has most certainly been reached. To obtain the mentioned vast improvements in thermal performance of the new generation of glazing there were several technical issues to be dealt with. They have been divided up into 6 tasks: Low emission glass, spacers, tempering, edge seal, evacuation and framing. The target center U-value of the vacuum window was set to be 0.7 W/m{sup 2}K, an ambitious target requiring several previously unsolved details to be solved. The center U-value of 0.7 W/m{sup 2}K has been reached and documented through this project. The production costs compares to that of existing glazing with the same insulating capabilities. (EHS) EFP-93; EFP-94; EFP-95; EFP-96; EU-BRITE-DURAM; 13 refs.

  5. Transparent conducting film: Effect of vacuum filtration of carbon ...

    Indian Academy of Sciences (India)


    polyethylene terephthalate (PET) film with an adhesive on a backside (Teraoka Seisakusyo Co Ltd) to measure the visible light transmittance. 2.2 Sample testing. Visible light transmittance and sheet resistance of the vacuum-filtered MWNT layer were measured. Visible light transmittance of the MWNT layer transplanted to ...

  6. Effect of Stochastic Charge Fluctuations on Dust Dynamics (United States)

    Matthews, Lorin; Shotorban, Babak; Hyde, Truell


    The charging of particles in a plasma environment occurs through the collection of electrons and ions on the particle surface. Depending on the particle size and the plasma density, the standard deviation of the number of collected elementary charges, which fluctuates due to the randomness in times of collisions with electrons or ions, may be a significant fraction of the equilibrium charge. We use a discrete stochastic charging model to simulate the variations in charge across the dust surface as well as in time. The resultant asymmetric particle potentials, even for spherical grains, has a significant impact on the particle coagulation rate as well as the structure of the resulting aggregates. We compare the effects on particle collisions and growth in typical laboratory and astrophysical plasma environments. This work was supported by the National Science Foundation under Grant PHY-1414523.

  7. Effects of barrier fluctuation on the tunneling dynamics in the ...

    Indian Academy of Sciences (India)

    Tunneling through fluctuating barrier has received considerable attention because of its potential use for modeling in many branches of physics and chemistry [1–24]. ... fluctuating potential barrier in the presence of both white and multiplicative noises. [20,21]. They have shown that the mean first passage time over the ...

  8. Effects of length fluctuations on the viscosity exponent in the necklace model

    Energy Technology Data Exchange (ETDEWEB)

    Aldao, C M [Institute of Materials Science and Technology (INTEMA), Universidad Nacional de Mar del Plata-CONICET, Juan B Justo 4302, B7608FDQ Mar del Plata (Argentina); Terranova, G R; Martin, H O [Physics Department, School of Exact and Natural Sciences, Universidad Nacional de Mar del Plata, Dean Funes 3350, B7602AYL Mar del Plata (Argentina)


    It is commonly accepted that contour length fluctuations increase the viscosity exponent for chains that diffuse by reptation. We found that length fluctuations in the necklace model can play an unexpected role as they can also decrease this exponent. A detailed analysis of the interplay between the discrete character of the model and how the fluctuations take place is presented in this work. Basically, we found that when fluctuations are symmetric their influence is the expected one; when fluctuations are not symmetric new effects can appear.

  9. Microbial effect of steam vacuum pasteurisation implemented after slaughtering and dressing of sheep and lamb. (United States)

    Hassan, Ammar Ali; Skjerve, Eystein; Bergh, Claus; Nesbakken, Truls


    The main objective of the study was to assess the effect of steam vacuum pasteurisation on carcass contamination with focus on Escherichia coli, Enterobacteriaceae and total plate count (TPC). Additionally, the effect of an additional tryptone soy agar (TSA) step for resuscitation of Enterobacteriaceae after steam vacuum pasteurisation was investigated. Steam vacuum pasteurisation was applied at a temperature of >82°C for a duration of 10s on sheep and lamb carcasses (n=120). Samples were taken immediately: i) after trimming just before the use of steam vacuum and ii) after use of steam vacuum. Nordic Committee on Food Analysis methods were used in microbial analyses. The differences in log reduction were found significant for all of the three microorganisms (psteam vacuum pasteurisation was higher in samples where TSA+violet red bile glucose agar (VRBGA) was used compared to samples where only VRBGA was used (pSteam vacuum pasteurisation was found efficient in reducing the total count, read as TPC, as well as the level of E. coli and Enterobacteriaceae. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Local effects of the quantum vacuum in Lorentz-violating electrodynamics (United States)

    Martín-Ruiz, A.; Escobar, C. A.


    The Casimir effect is one of the most remarkable consequences of the nonzero vacuum energy predicted by quantum field theory. In this paper we use a local approach to study the Lorentz violation effects of the minimal standard model extension on the Casimir force between two parallel conducting plates in the vacuum. Using a perturbative method similar to that used for obtaining the Born series for the scattering amplitudes in quantum mechanics, we compute, at leading order in the Lorentz-violating coefficients, the relevant Green's function which satisfies given boundary conditions. The standard point-splitting technique allow us to express the vacuum expectation value of the stress-energy tensor in terms of the Green's function. We discuss its structure in the region between the plates. We compute the renormalized vacuum stress, which is obtained as the difference between the vacuum stress in the presence of the plates and that of the vacuum. The Casimir force is evaluated in an analytical fashion by two methods: by differentiating the renormalized global energy density and by computing the normal-normal component of the renormalized vacuum stress. We compute the local Casimir energy, which is found to diverge as approaching the plates, and we demonstrate that it does not contribute to the observable force.

  11. The effect of vacuum pump oil on the chemotactic behavior of soil bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Dunifon, R.E.; Hazen, T.C.


    The use of biodegradation in the cleanup and transformation of waste materials is an economical and environmentally safe practice. Using chemotaxis, or the movement of bacteria toward or away from compounds, in biodegradation is an area that is being studied at the Savannah River Laboratory. This study investigates the inhibition of vacuum pump oil on the chemotaxis of soil bacteria. It was found that vacuum pump oil does have an inhibitory effect on the movement of bacteria. This inhibition will have to be considered when studying the possibility of using chemotaxis to degrade vacuum pump oil, or any other petroleum products. 5 refs., 5 figs.

  12. Spatial density fluctuations and selection effects in galaxy redshift surveys

    Energy Technology Data Exchange (ETDEWEB)

    Labini, Francesco Sylos [Centro Studi e Ricerche Enrico Fermi, Via Panisperna 89 A, Compendio del Viminale, 00184 Rome (Italy); Tekhanovich, Daniil [Faculty of Mathematics and Mechanics, Saint Petersburg State University, Staryj Peterhoff, 198504, St.Petersburg (Russian Federation); Baryshev, Yurij V., E-mail:, E-mail:, E-mail: [Institute of Astronomy, St.Petersburg State University, Staryj Peterhoff, 198504, St.Petersburg (Russian Federation)


    One of the main problems of observational cosmology is to determine the range in which a reliable measurement of galaxy correlations is possible. This corresponds to determining the shape of the correlation function, its possible evolution with redshift and the size and amplitude of large scale structures. Different selection effects, inevitably entering in any observation, introduce important constraints in the measurement of correlations. In the context of galaxy redshift surveys selection effects can be caused by observational techniques and strategies and by implicit assumptions used in the data analysis. Generally all these effects are taken into account by using pair-counting algorithms to measure two-point correlations. We review these methods stressing that they are based on the a-priori assumption that galaxy distribution is spatially homogeneous inside a given sample. We show that, when this assumption is not satisfied by the data, results of the correlation analysis are affected by finite size effects. In order to quantify these effects, we introduce a new method based on the computation of the gradient of galaxy counts along tiny cylinders. We show, by using artificial homogeneous and inhomogeneous point distributions, that this method identifies redshift dependent selection effects and disentangles them from the presence of large scale density fluctuations. We then apply this new method to several redshift catalogs and we find evidence that galaxy distribution, in those samples where selection effects are small enough, is characterized by power-law correlations with exponent γ=0.9 up to 20 Mpc/h followed by a change of slope that, in the range 20–100 Mpc/h, corresponds to a power-law exponent γ=0.25. Whether a crossover to spatial uniformity occurs at ∼ 100 Mpc/h or larger scales cannot be clarified by the present data.

  13. Functional renormalization group study of fluctuation effects in fermionic superfluids

    Energy Technology Data Exchange (ETDEWEB)

    Eberlein, Andreas


    This thesis is concerned with ground state properties of two-dimensional fermionic superfluids. In such systems, fluctuation effects are particularly strong and lead for example to a renormalization of the order parameter and to infrared singularities. In the first part of this thesis, the fermionic two-particle vertex is analysed and the fermionic renormalization group is used to derive flow equations for a decomposition of the vertex in charge, magnetic and pairing channels. In the second part, the channel-decomposition scheme is applied to various model systems. In the superfluid state, the fermionic two-particle vertex develops rich and singular dependences on momentum and frequency. After simplifying its structure by exploiting symmetries, a parametrization of the vertex in terms of boson-exchange interactions in the particle-hole and particle-particle channels is formulated, which provides an efficient description of the singular momentum and frequency dependences. Based on this decomposition of the vertex, flow equations for the effective interactions are derived on one- and two-loop level, extending existing channel-decomposition schemes to (i) the description of symmetry breaking in the Cooper channel and (ii) the inclusion of those two-loop renormalization contributions to the vertex that are neglected in the Katanin scheme. In the second part, the superfluid ground state of various model systems is studied using the channel-decomposition scheme for the vertex and the flow equations. A reduced model with interactions in the pairing and forward scattering channels is solved exactly, yielding insights into the singularity structure of the vertex. For the attractive Hubbard model at weak coupling, the momentum and frequency dependence of the two-particle vertex and the frequency dependence of the self-energy are determined on one- and two-loop level. Results for the suppression of the superfluid gap by fluctuations are in good agreement with the literature

  14. Effect of quantum fluctuation in error-correcting codes. (United States)

    Otsubo, Yosuke; Inoue, Jun-ichi; Nagata, Kenji; Okada, Masato


    We discuss the decoding performance of error-correcting codes based on a model in which quantum fluctuations are introduced by means of a transverse field. The essential issue in this paper is whether quantum fluctuations improve the decoding quality compared with the conventional estimation based on thermal fluctuations, which is called finite-temperature decoding. We found that an estimation incorporating quantum fluctuations approaches the optimal performance of finite-temperature decoding. The results are illustrated by numerically solving saddle-point equations and performing a Monte Carlo simulation. We also evaluated the upper bound of the overlap between the original sequence and the decoded sequence derived from the equations of state for the order parameters, which is a measure of the decoding performance.

  15. Effects of vacuum packaging conditions on the quality, biochemical changes and the durability of ostrich meat. (United States)

    Brenesselová, Martina; Koréneková, Beáta; Mačanga, Ján; Marcinčák, Slavomír; Jevinová, Pavlína; Pipová, Monika; Turek, Peter


    In this study, the effects of vacuum packaging conditions on the concentrations of lactic acid, malondialdehyde, pH, microbial and sensory analysis were determined during chilled storage of ostrich meat. Meat was packed as follows: vacuum packed from 1st day (VP-1), vacuum packed from 3rd day (VP-3) and non-vacuum packed (NVP). Analysis were performed at 1st, 7th, 14th, 21st day after slaughter. Meat consisted of 74.69% water, 2.29% fats, 20.95% proteins. Package conditions had significant effect on the pH (NVP: 6.54 on the 14th day, VP-1: 6.05 and VP-3: 6.07 on the 21th day pvacuum packed from 1st day is necessary for the 21 days storage of ostrich meat. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Controllable effects of quantum fluctuations on spin free-induction decay at room temperature (United States)

    Liu, Gang-Qin; Pan, Xin-Yu; Jiang, Zhan-Feng; Zhao, Nan; Liu, Ren-Bao


    Fluctuations of local fields cause decoherence of quantum objects. Usually at high temperatures, thermal noises are much stronger than quantum fluctuations unless the thermal effects are suppressed by certain techniques such as spin echo. Here we report the discovery of strong quantum-fluctuation effects of nuclear spin baths on free-induction decay of single electron spins in solids at room temperature. We find that the competition between the quantum and thermal fluctuations is controllable by an external magnetic field. These findings are based on Ramsey interference measurement of single nitrogen-vacancy center spins in diamond and numerical simulation of the decoherence, which are in excellent agreement. PMID:22666535

  17. Effect of vacuum roasting on acrylamide formation and reduction in coffee beans. (United States)

    Anese, Monica; Nicoli, Maria Cristina; Verardo, Giancarlo; Munari, Marina; Mirolo, Giorgio; Bortolomeazzi, Renzo


    Coffea arabica beans were roasted in an oven at 200 °C for increasing lengths of time under vacuum (i.e. 0.15 kPa). The samples were then analysed for colour, weight loss, acrylamide concentration and sensory properties. Data were compared with those obtained from coffee roasted at atmospheric pressure (i.e. conventional roasting), as well as at atmospheric pressure for 10 min followed by vacuum treatment (0.15 kPa; i.e. conventional-vacuum roasting). To compare the different treatments, weight loss, colour and acrylamide changes were expressed as a function of the thermal effect received by the coffee beans during the different roasting processes. Vacuum-processed coffee with medium roast degree had approximately 50% less acrylamide than its conventionally roasted counterpart. It was inferred that the low pressure generated inside the oven during the vacuum process exerted a stripping effect preventing acrylamide from being accumulated. Vacuum-processed coffee showed similar colour and sensory properties to conventionally roasted coffee. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Hemodynamic effects of vacuum-assisted closure therapy in cardiac surgery: assessment using magnetic resonance imaging. (United States)

    Petzina, Rainer; Ugander, Martin; Gustafsson, Lotta; Engblom, Henrik; Sjögren, Johan; Hetzer, Roland; Ingemansson, Richard; Arheden, Håkan; Malmsjö, Malin


    The hemodynamic effects of vacuum-assisted closure therapy in cardiac surgery are debated. The aim of the present study was to quantify cardiac output and left ventricular chamber volumes after vacuum-assisted closure using magnetic resonance imaging, which is known to be the most accurate method for quantifying these measures. Six pigs had median sternotomy followed by vacuum-assisted closure treatment in the presence and absence of a paraffin gauze interface dressing. Cardiac output and stroke volume were examined using magnetic resonance imaging flow quantification (breath-hold and real-time). Chamber volumes were assessed using cine magnetic resonance imaging. Cardiac output and stroke volume decreased immediately after application of negative pressures of 75, 125, and 175 mm Hg (13% +/- 1% decrease in cardiac output). Interposition of 4 layers of paraffin gauze dressing over the heart during vacuum-assisted closure therapy resulted in a smaller decrease in cardiac output (8% +/- 1%). Vacuum-assisted closure therapy results in an immediate decrease in cardiac output, although to a lesser extent than shown previously. Covering the heart with a wound interface dressing lessens the hemodynamic effects of vacuum-assisted closure.

  19. Effects of a Fluctuating Carrying Capacity on the Generalized Malthus-Verhulst Model

    Directory of Open Access Journals (Sweden)

    Héctor Calisto


    Full Text Available We consider a generalized Malthus-Verhulst model with a fluctuating carrying capacity and we study its effects on population growth. The carrying capacity fluctuations are described by a Poissonian process with an exponential correlation function. We will find an analytical expression for the average of a number of individuals and show that even in presence of a fluctuating carrying capacity the average tends asymptotically to a constant quantity.

  20. Enhanced conductance fluctuation by quantum confinement effect in graphene nanoribbons. (United States)

    Xu, Guangyu; Torres, Carlos M; Song, Emil B; Tang, Jianshi; Bai, Jingwei; Duan, Xiangfeng; Zhang, Yuegang; Wang, Kang L


    Conductance fluctuation is usually unavoidable in graphene nanoribbons (GNR) due to the presence of disorder along its edges. By measuring the low-frequency noise in GNR devices, we find that the conductance fluctuation is strongly correlated with the density-of-states of GNR. In single-layer GNR, the gate-dependence of noise shows peaks whose positions quantitatively match the subband positions in the band structures of GNR. This correlation provides a robust mechanism to electrically probe the band structure of GNR, especially when the subband structures are smeared out in conductance measurement.

  1. Constructive effects of fluctuations in genetic and biochemical regulatory systems. (United States)

    Steuer, Ralf; Zhou, Changsong; Kurths, Jürgen


    Biochemical and genetic regulatory systems that involve low concentrations of molecules are inherently noisy. This intrinsic stochasticity has received considerable interest recently, leading to new insights about the sources and consequences of noise in complex systems of genetic regulation. However, most prior work was devoted to the reduction of fluctuation and the robustness of cellular function with respect to intrinsic noise. Here, we focus on several scenarios in which the inherent molecular fluctuations are not merely a nuisance, but act constructively and bring about qualitative changes in the dynamics of the system. It will be demonstrated that in many typical situations biochemical and genetic regulatory systems may utilize intrinsic noise to their advantage.

  2. The effect of glass coating emittance and frame rebate on heat transfer through vacuum and electrochromic vacuum glazed windows

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Yueping; Eames, Philip C. [Centre for Sustainable Technologies, School of the Built Environment, University of Ulster, Newtownabbey, BT37 0QB, N. Ireland (United Kingdom)


    The thermal performance of an electrochromic vacuum glazing and a vacuum glazing with a range of low-emittance coatings and frame rebate depths were simulated for insolations between 0 and 1000Wm{sup -2} using a three-dimensional finite volume model. The vacuum glazing simulated comprised two 0.4mx0.4m glass panes separated by a 0.12mm wide evacuated space supported by a 0.32mm diameter pillar array spaced at 25mm. The two glass sheets were sealed contiguously by a 6mm wide metal edge seal and had either one or two low-emittance coatings. For the electrochromic vacuum glazing, a third glass pane on which an electrochromic layer was deposited was assumed to be sealed to an evacuated glass unit, to enable control of visible light transmittance and solar gain and thus improve occupant thermal comfort. It is shown that for both vacuum glazing and electrochromic vacuum glazings, when the coating emittance value is very low (close to 0.02), the use of two low-emittance coatings only gives limited improvement in glazing performance. The use of a single currently expensive low-emittance coating in both systems provided acceptable performance. Deeper frame rebate depths gave significant improvements in thermal performance for both glazing systems. (author)

  3. Effect of directional selection for body size on fluctuating asymmetry ...

    Indian Academy of Sciences (India)

    Variation in the subtle differences between the right and left sides of bilateral characters or fluctuating asymmetry (FA) has been considered as an indicator of an organism's ability to cope with genetic and environmental stresses during development. However, due to inconsistency in the results of empirical studies, the ...

  4. Lake Fluctuation Effectively Regulates Wetland Evapotranspiration: A Case Study of the Largest Freshwater Lake in China

    Directory of Open Access Journals (Sweden)

    Xiaosong Zhao


    Full Text Available Lakes and wetlands provide valuable water resources. Wetland evapotranspiration (ET is a key hydrologic component; however, the effects of lake fluctuation on wetland ET remain unclear. The Poyang Lake is the largest freshwater lake in China and experiences a dramatic fluctuation in water level and inundated area. This study used remote sensing data to estimate the wetland ET for Poyang Lake and to illustrate the distribution of wetland ET and its response to lake fluctuations. Our results showed that wetland ET was related to lake fluctuation both spatially and temporally. Within the same year, the difference between annual water evaporation (Ewater and wetland ET (ETwetland was primarily attributed to lake fluctuation through its effects on inundated area and exposure days. A 1% increase in inundated area would result in a 7.87 ± 1.13 mm a−1 reduction in annual Ewater-to-ETwetland differences, and a 10-day elongation of exposure could lead to an 11.1 ± 1.6 mm a−1 increase in annual Ewater-to-ETwetland differences, on average. Inter-annually, the Ewater-to-ETwetland differences were attributed to the combined effects of atmospheric and environmental variables and lake fluctuation. The lake fluctuation contributed 73% to the inter-annual ET difference, followed by relative humidity (19%, net radiation (5%, and wind speed (4%. Overall, lake fluctuation effectively regulates wetland ET, and its effect should receive careful consideration in hydrological and water resources studies under the current changing climate.

  5. The effect of vacuum cleaners on the concentration and particle size distribution of airborne cat allergen. (United States)

    Woodfolk, J A; Luczynska, C M; de Blay, F; Chapman, M D; Platts-Mills, T A


    Vacuum cleaners are essential for the removal of dust from the surface of carpets; however, they may also contribute to airborne dust both by leakage through the cleaner and disturbance of floor dust. The present studies used established techniques for measuring airborne Fel d I to study the effects of vacuum cleaners on airborne cat allergen under laboratory conditions and in houses with cats. Nine different models were loaded with dust containing 50 mg Fel d I and run for 15 minutes in a laboratory room (volume approximately 18 m3). Leakage was expressed as the airborne concentration of allergen in nanograms per cubic meter. Cleaners incorporating a double-thickness dust bag either did not leak, that is, less than 0.4 ng Fel d I/m3 or had minor leakage approximately 5 ng/m3. Vacuum cleaners with single-thickness paper bags leaked more, that is, 15 to > 90 ng/m3 with the exception of the cleaner with an efficient outer bag. Detailed studies on a vacuum cleaner that leaked showed that placing dust in the bag, replacing the dust bag with a double-thickness bag, and placing an electrostatic filter over the exhaust reduced levels from greater than 90 ng/m3 to less than 2 ng/m3. Two water-filter vacuum cleaners each emitted cat allergen (up to > 100 ng/m3) with a mean of approximately 90% on particles less than 2.5 microns diameter. This emission could be almost completely controlled by taping electrostatic filter paper over the air outlet. In houses with cats, different models of vacuum cleaners could either reduce or increase total airborne allergen, and could also selectively increase certain particle sizes. These results suggest that cat allergen is a good model for studying the effectiveness of vacuum cleaners recommended to allergic patients.

  6. The effect of debris accumulation on and filter resistance to airflow for four commercially available vacuum cleaners. (United States)

    Heitbrink, William A; Santalla-Elias, Javier


    applications where adequate dust control can be achieved at airflows less than 0.85 m(3)/min (30 cfm). Vacuum cleaners with cyclonic pre-separators provided superior and cost-effective dust control compared with vacuums with bags when dust loading was high and when more than 30 cfm of airflow is needed for dust control.

  7. The radio-frequency fluctuation effect on the floating harmonic method

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jaewon; Kim, Kyung-Hyun [Department of Electrical Engineering, Hanyang University, Wangsimni-ro 222, Seongdong-gu, Seoul 04763 (Korea, Republic of); Kim, Dong-Hwan [Department of Nanoscale Semiconductor Engineering, Hanyang University, Wangsimni-ro 222, Seongdong-gu, Seoul 04763 (Korea, Republic of); Chung, Chin-Wook, E-mail: [Department of Electrical Engineering, Hanyang University, Wangsimni-ro 222, Seongdong-gu, Seoul 04763 (Korea, Republic of); Department of Nanoscale Semiconductor Engineering, Hanyang University, Wangsimni-ro 222, Seongdong-gu, Seoul 04763 (Korea, Republic of)


    The radio-frequency (RF) plasma diagnostics with an electrical probe facing a challenge, because the RF fluctuation oscillates the plasma potential and distorts the current-voltage (I-V) curve. As Langmuir probe is widely used in plasma diagnostics, many researchers have been studying the effect of RF fluctuation on probe and compensation methods. On the other hand, there have not been enough studies on the fluctuation effect on the floating harmonic method. Therefore, we investigated the impact of RF fluctuation on the floating harmonic method theoretically and experimentally. When the electrons are in ideal Maxwellian distribution, the floating potential is negatively shifted by the RF fluctuation, but the fluctuation does not distort I-V curve around the floating potential. However, in practical plasmas, the I-V curve and their harmonic components are distorted. This RF fluctuation effect becomes more significant in a low density plasma with a high impedance sheath. The second harmonic current decreases with the RF fluctuation while the first harmonic current is merely affected. Therefore, the electron temperatures measured with the floating harmonic method under low density plasma with uncompensated probe are overestimated than the results obtained with the compensated probe.

  8. Critical Casimir force in the superfluid phase: effect of fluctuations


    Biswas, Shyamal; Bhattacharjee, J K; Samanta, Himadri S.; Bhattacharyya, Saugata; Hu, Bambi


    We have considered the critical Casimir force on a $^4$He film below and above the bulk $\\lambda$ point. We have explored the role of fluctuations around the mean field theory in a perturbative manner, and have substantially improved the mean field result of Zandi et al [Phys. Rev. E {\\bf 76}, 030601(R) (2007)]. The Casimir scaling function obtained by us approaches a universal constant ($-\\frac{\\zeta(3)}{8\\pi}$) for $T\\lesssim 2.13~\\text{K}$.

  9. The effect of climate fluctuation on chimpanzee birth sex ratio.

    Directory of Open Access Journals (Sweden)

    Hjalmar S Kühl

    Full Text Available Climate and weather conditions, such as the North Atlantic Oscillation, precipitation and temperature influence the birth sex ratio (BSR of various higher latitude species, including deer, elephant seals or northern human populations. Although, tropical regions show only little variation in temperature, climate and weather conditions can fluctuate with consequences for phenology and food resource availability. Here, we evaluate, whether the BSR of chimpanzees, inhabiting African tropical forests, is affected by climate fluctuations as well. Additionally, we evaluate, if variation in consumption of a key food resource with high nutritional value, Coula edulis nuts, is linked to both climate fluctuations and variation in BSR. We use long-term data from two study groups located in Taï National Park, Côte d'Ivoire to assess the influence of local weather conditions and the global climate driver El Niño Southern Oscillation (ENSO on offspring sex. Côte d'Ivoire has experienced considerable climate variation over the last decades, with increasing temperature and declining precipitation. For both groups we find very similar time windows around the month of conception, in which offspring sex is well predicted by ENSO, with more males following low ENSO values, corresponding to periods of high rainfall. Furthermore, we find that the time spent cracking and feeding on Coula nuts is strongly influenced by climate conditions. Although, some of our analysis suggest that a higher proportion of males is born after periods with higher nut consumption frequency, we cannot conclude decisively at this point that nut consumption may influence shifts in BSR. All results combined suggest that also chimpanzees may experience climate related shifts in offspring sex ratios as response to climate fluctuation.

  10. Life cycle environmental impacts of vacuum cleaners and the effects of European regulation

    Energy Technology Data Exchange (ETDEWEB)

    Gallego-Schmid, Alejandro, E-mail:; Mendoza, Joan Manuel F.; Jeswani, Harish Kumar; Azapagic, Adisa


    Energy efficiency of vacuum cleaners has been declining over the past decades while at the same time their number in Europe has been increasing. The European Commission has recently adopted an eco-design regulation to improve the environmental performance of vacuum cleaners. In addition to the existing directive on waste electrical and electronic equipment (WEEE), the regulation could potentially have significant effects on the environmental performance of vacuum cleaners. However, the scale of the effects is currently unknown, beyond scant information on greenhouse gas emissions. Thus, this paper considers for the first time life cycle environmental impacts of vacuum cleaners and the effects of the implementation of these regulations at the European level. The effects of electricity decarbonisation, product lifetime and end-of-life disposal options are also considered. The results suggest that the implementation of the eco-design regulation alone will reduce significantly the impacts from vacuum cleaners (37%–44%) by 2020 compared with current situation. If business as usual continued and the regulation was not implemented, the impacts would be 82%–109% higher by 2020 compared to the impacts with the implementation of the regulation. Improvements associated with the implementation of the WEEE directive will be much smaller (< 1% in 2020). However, if the WEEE directive did not exist, then the impacts would be 2%–21% higher by 2020 relative to the impacts with the implementation of the directive. Further improvements in most impacts (6%–20%) could be achieved by decarbonising the electricity mix. Therefore, energy efficiency measures must be accompanied by appropriate actions to reduce the environmental impacts of electricity generation; otherwise, the benefits of improved energy efficiency could be limited. Moreover, because of expected lower life expectancy of vacuum cleaners and limited availability of some raw materials, the eco-design regulation should

  11. Effect of osmotic dehydration and vacuum-frying parameters to produce high-quality mango chips. (United States)

    Nunes, Yolanda; Moreira, Rosana G


    Mango (Mangifera indica L.) is a fruit rich in flavor and nutritional values, which is an excellent candidate for producing chips. The objective of this study was to develop high-quality mango chips using vacuum frying. Mango ("Tommy Atkins") slices were pretreated with different maltodextrin concentrations (40, 50, and 65, w/v), osmotic dehydration times (45, 60, and 70 min), and solution temperatures (22 and 40 degrees C). Pretreated slices were vacuum fried at 120, 130, and 138 degrees C and product quality attributes (oil content, texture, color, carotenoid content) determined. The effect of frying temperatures at optimum osmotic dehydration times (65 [w/v] at 40 degrees C) was assessed. All samples were acceptable (scores > 5) to consumer panelists. The best mango chips were those pretreated with 65 (w/v) concentration for 60 min and vacuum fried at 120 degrees C. Mango chips under atmospheric frying had less carotenoid retention (32%) than those under vacuum frying (up to 65%). These results may help further optimize vacuum-frying processing of high-quality fruit-based snacks.

  12. Effects of stochastic population fluctuations in two models of biological macroevolution (United States)

    Murase, Yohsuke; Shimada, Takashi; Ito, Nobuyasu; Rikvold, Per Arne

    Two mathematical models of macroevolution are studied. These models have population dynamics at the species level, and mutations and extinction of species are also included. The population dynamics are updated by difference equations with stochastic noise terms that characterize population fluctuations. The effects of the stochastic population fluctuations on diversity and total population sizes on evolutionary time scales are studied. In one model, species can make either predator-prey, mutualistic, or competitive interactions, while the other model allows only predator-prey interactions. When the noise in the population dynamics is strong enough, both models show intermittent behavior and their power spectral densities show approximate 1/f fluctuations. In the noiseless limit, the two models have different power spectral densities. For the predator-prey model, 1/f2 fluctuations appears, indicating random-walk like behavior, while the other model still shows 1/f noise. These results indicate that stochastic population fluctuations may significantly affect long-time evolutionary dynamics.

  13. Effect of Vacuum Frying on Changes in Quality Attributes of Jackfruit (Artocarpus heterophyllus) Bulb Slices. (United States)

    Maity, Tanushree; Bawa, A S; Raju, P S


    The effect of frying temperatures and durations on the quality of vacuum fried jackfruit (JF) chips was evaluated. Moisture content and breaking force of JF chips decreased with increase in frying temperature and time during vacuum frying whereas the oil content increased. The frying time for JF chips was found to be 30, 25, and 20 minutes at 80, 90, and 100°C, respectively. JF chips fried at higher temperature resulted in maximum shrinkage (48%). The lightness in terms of hunter L (*) value decreased significantly (P < 0.05) during frying. Sensory evaluation showed maximum acceptability for JF chips fried at 90°C for 25 min. Frying under vacuum at lower temperatures was found to retain bioactive compounds such as total phenolics, total flavonoids, and total carotenoids in JF chips. Almost 90% of carotenoids were lost from the samples after 30 min of frying at 100°C.

  14. Effect of Vacuum Frying on Changes in Quality Attributes of Jackfruit (Artocarpus heterophyllus Bulb Slices

    Directory of Open Access Journals (Sweden)

    Tanushree Maity


    Full Text Available The effect of frying temperatures and durations on the quality of vacuum fried jackfruit (JF chips was evaluated. Moisture content and breaking force of JF chips decreased with increase in frying temperature and time during vacuum frying whereas the oil content increased. The frying time for JF chips was found to be 30, 25, and 20 minutes at 80, 90, and 100°C, respectively. JF chips fried at higher temperature resulted in maximum shrinkage (48%. The lightness in terms of hunter L* value decreased significantly (P<0.05 during frying. Sensory evaluation showed maximum acceptability for JF chips fried at 90°C for 25 min. Frying under vacuum at lower temperatures was found to retain bioactive compounds such as total phenolics, total flavonoids, and total carotenoids in JF chips. Almost 90% of carotenoids were lost from the samples after 30 min of frying at 100°C.

  15. Effect of acceleration on localized fermionic Gaussian states: From vacuum entanglement to maximally entangled states (United States)

    Richter, Benedikt; Lorek, Krzysztof; Dragan, Andrzej; Omar, Yasser


    We study the effects of acceleration on fermionic Gaussian states of localized modes of a Dirac field. We consider two wave packets in a Gaussian state and transform these to an accelerated frame of reference. In particular, we formulate the action of this transformation as a fermionic quantum channel. Having developed the general framework for fermions, we then investigate the entanglement of the vacuum, as well as the entanglement in Bell states. We find that with increasing acceleration vacuum entanglement increases, while the entanglement of Bell states decreases. Notably, our results have an immediate operational meaning given the localization of the modes.

  16. Giant fluctuations and structural effects in a flocking epithelium (United States)

    Giavazzi, Fabio; Malinverno, Chiara; Corallino, Salvatore; Ginelli, Francesco; Scita, Giorgio; Cerbino, Roberto


    Epithelial cells cultured in a monolayer are very motile in isolation but reach a near-jammed state when mitotic division increases their number above a critical threshold. We have recently shown that a monolayer can be reawakened by over-expression of a single protein, RAB5A, a master regulator of endocytosis. This reawakening of motility was explained in terms of a flocking transition that promotes the emergence of a large-scale collective migratory pattern. Here we focus on the impact of this reawakening on the structural properties of the monolayer. We find that the unjammed monolayer is characterised by a fluidisation at the single cell level, and by enhanced non-equilibrium large-scale number fluctuations at a larger length scale. Also, with the help of numerical simulations, we trace back the origin of these fluctuations to the self-propelled active nature of the constituents, and to the existence of a local alignment mechanism, leading to the spontaneous breaking of the orientational symmetry.

  17. Effects of ultralow oxygen and vacuum treatments on bed bug (Heteroptera: Cimicidae) survival (United States)

    Control of bed bugs has always been problematic, balancing among efficacy, safety, and cost. In this study, ultralow oxygen (ULO) and vacuum treatments were tested on bed bugs to develop a safer, effective, and environmental friendly solution to bed bug infestations. ULO treatments were establishe...

  18. Experimental and theoretical analysis of vacuum circuit breaker prestrike effect on a transformer

    NARCIS (Netherlands)

    Popov, M.; Smeets, R.P.P.; Van der Sluis, L.; De Herdt, H.; Declerq, J.


    The work presented in this paper deals with the investigation of circuit breaker prestrike effect that occurs during energizing a distribution transformer. An experimental test setup that consists of a supply transformer, a vacuum circuit breaker (VCB), a cable and a test transformer is built, and

  19. Reparation effects of vacuum wound therapy in patients with diabetic foot syndrome

    Directory of Open Access Journals (Sweden)

    Besedin A.M.


    Full Text Available Vacuum Therapy (Vacuum-assisted closure, VAC - a method of complex therapy which is used to improve the healing of both acute chronic wounds in patients with diabetic foot syndrome. Due to widespread introduction of this technique, unique cell, extracellular and general effects of its use in the treatment of patients with purulent-necrotic complications of diabetic foot syndrome, a technique of vacuum wound therapy has been successfully used in many surgical departments of Ukraine. Despite the diversity of the clinical effects of VAC-therapy and appearance of number of publications, in the domestic and foreign literature physiological basis of this method have not been studied completely. The effectiveness of vacuum therapy explain: the reduction of the size of the wound, the stabilization of the wound environment (due to the removal of inflammatory mediators and cytokines, microdeformation and remodeling of cell, rows reduction of edema, reduction of bacterial contamination, etc. At the same time, mechanisms of blood flow enhancement at different duration of VAC-therapy use, remain unclear its effect on the third phase of wound healing process as well.

  20. The Vacuum Bell for Treatment of Pectus Excavatum: an Effective Tool for Conservative Therapy

    Directory of Open Access Journals (Sweden)

    Frank Haecker


    Full Text Available Aim: Pectus Excavatum (PE is the most common chest wall malformation, and one of the most frequent major congenital anomalies. Surgical repair of PE in childhood is a well-established procedure. Previously used operative techniques to correct PE were largely based on the Ravitch technique. Today, the minimally invasive repair (MIRPE by Nuss is well established. Conservative treatment with the vacuum bell to elevate the funnel in patients with PE, represents a potential alternative. Material and Methods:  A suction cup is used to create a vacuum at the anterior chest wall. 3 different sizes of vacuum bell exist which are selected according to the individual patients age. When creating the vacuum, the lift of the sternum is obvious and remains for a different time period. The device should be used for a minimum of 30 minutes (2/day, and may be used up to a maximum of several hours daily. Results; 93 patients (77 males, 16 females, aged 3 to 61 years (median 17.8 years used the vacuum bell for 1 to maximum 24 months. Computed tomographic scans showed that the device lifted the sternum and ribs immediately. In addition, this was confirmed thoracoscopically during the MIRPE procedure. After 18 months in average, the sternum was lifted to a normal level in 9 patients. Relevant side effects were not noted. Conclusions: The vacuum bell has proved to be an alternative therapeutic option in selected patients with PE. The initial results proved to be dramatic, but longterm results are so far lacking, and further evaluation and follow-up studies are necessary. 

  1. Effective parameters of metal-dielectric composites: influence of eddy currents due to density fluctuations


    Vinogradov, A. P.; Burokur, N.; Zouhdi, S.


    Abstract It is shown that the space fluctuations of concentration of conducting inclusions might be responsible for the well-known disagreement between theory and experiment at determining microwave losses in metal-dielectric mixture: the theories (percolation theory, effective medium theory, etc.) predict much lower losses than those measured in experiment. It is demonstrated that if the effective skin depth in the regions occupied by the fluctuation is com...

  2. Study on the Effect of Inlet Fluctuation on Cavitation in a Cone Flow Channel. (United States)

    Hai, Liu; Shuping, Cao; Xiaohui, Luo


    A mathematical method was conducted to investigate the mechanism of formation of cavitation cloud, while the inlet stream contains a fluctuating flow. Based on the Rayleigh-Plesset equation and the static pressure distribution in a cone flow channel, parameters related to cavitation cloud are estimated, and the collapse pressure of the cavitation cloud is obtained by solving the equation of Mørch's model. Moreover, the effect of the amplitude and frequency of inlet fluctuation on cavitation is studied. Results revealed that the smaller the amplitude, the smaller the cloud and the lower the collapse pressure. And frequency of fluctuating stream was found to have a relative great effect on frequency of peak pressure but not so significant on peak collapse pressure and size of cloud. It is concluded that limiting the inlet fluctuation reduces the erosion and noise generated by cavitation collapse.

  3. Effects of turbulent fluctuations on density measurements with microwave reflectometry in tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Mazzucato, E.; Nazikian, R.


    The short-scale turbulence of tokamak plasmas has deleterious effects on the measurement of plasma density with microwave reflectometry. Density fluctuations may lead to large amplitude and phase modulations of the reflected wave which can impair the measurement of the wave group delay, and hence the determination of the plasma density. The role played by different types of turbulent fluctuations and the limitations imposed on microwave reflectometry are discussed in this paper.

  4. Effect of two different types of vacuum cleaners on airborne Fel d 1 levels. (United States)

    Rønborg, S M; Poulsen, L K; Skov, P S; Mosbech, H


    Vacuum cleaners may increase the level of airborne allergens by leakage through the cleaners or by disturbance of floor dust by the exhaust air produced. The aim of this study was to evaluate the short-term effect of vacuum cleaning with two different types of cleaners on airborne cat allergen analyzed by a biologic and by an immunochemical test. Ten homes with cats were cleaned in random order with a 1-week interval by a traditional canister type vacuum cleaner (T) and a semi-stationary vacuum cleaner (S) that conducts the air to the exterior through a valve in the wall. Airborne particles were collected by air sampling for 2 hours and cat allergen, Fel d 1, was quantified biologically by basophil histamine release test (HR test) and immunochemically by enzyme linked immunosorbent assay (ELISA). Using the S resulted in smaller amounts of airborne cat allergen than the T (mean 2.1 ng/m3 air (range .8 to 12.5) versus 5.2 ng/m3 (1.3 to 13.3), P < .002 measured by ELISA). Results from ELISA and HR test correlated well (r = .91, P < .001). The use of S with exhaust to the outside of the dwelling gave rise to less airborne low particle size allergen during the cleaning procedure than a T method. The basophil histamine release test could be a valid alternative method to establish allergen content in environmental samples especially in allergen systems with no available monoclonal antibodies.

  5. Effect of Various Pretreatments on Quality Attributes of Vacuum-Fried Shiitake Mushroom Chips

    Directory of Open Access Journals (Sweden)

    Aiqing Ren


    Full Text Available The objective of this study is to investigate the effects of pretreatments on the quality of vacuum-fried shiitake mushroom slices. Four different pretreatments addressed in this study were (1 blanching as control, (2 blanching and osmotic dehydration with maltodextrin (MD solution, (3 blanching, osmotic dehydration, and coating with sodium carboxymethyl cellulose (CMC, (4 blanching and osmotic dehydration, followed by freezing. All samples were pretreated and then fried in palm oil at 90°C with vacuum degree of −0.095 MPa for 30 min. The results showed that pretreatments significantly (p0.05 differences of fried chip in the texture among the four different pretreatments. The aw values of all the fried chips were less than 0.38, indicating that the products had a long shelf life. Therefore, the blanching, osmotic dehydration, and coating pretreatment before vacuum frying was the most suitable pretreatment for vacuum-fried shiitake mushroom chips.

  6. Vacuum polarization and photon mass in inflation

    CERN Document Server

    Prokopec, T; Prokopec, Tomislav; Woodard, Richard P.


    We give a pedagogical review of a mechanism through which long wave length photons can become massive during inflation. Our account begins with a discussion of the period of exponentially rapid expansion known as inflation. We next describe how, when the universe is not expanding, quantum fluctuations in charged particle fields cause even empty space to behave as a polarizable medium. This is the routinely observed phenomenon of vacuum polarization. We show that the quantum fluctuations of low mass, scalar fields are enormously amplified during inflation. If one of these fields is charged, the vacuum polarization effect of flat space is strengthened to the point that long wave length photons acquire mass. Our result for this mass is shown to agree with a simple model in which the massive photon electrodynamics of Proca emerges from applying the Hartree approximation to scalar quantum electrodynamics during inflation. One does not measure a huge photon mass today because the original phase of inflation ended w...

  7. Effect of static porosity fluctuations on reactive transport in a porous medium (United States)

    L'Heureux, Ivan


    Reaction-diffusive transport phenomena in porous media are ubiquitous in engineering applications, biological and geochemical systems. The porosity field is usually random in space, but most models consider the porosity field as a well-defined deterministic function of space and time and ignore the porosity fluctuations. They use a reaction-diffusion equation written in terms of an average porosity and average concentration fields. In this contribution, we treat explicitly the effect of spatial porosity fluctuations on the dynamics of a concentration field for the case of a one-dimensional reaction-transport system with nonlinear kinetics. Three basic assumptions are considered. (i) The porosity fluctuations are assumed to have Gaussian properties and an arbitrary variance; (ii) we assume that the noise correlation length is small compared to the relevant macroscopic length scale; (iii) and we assume that the kinetics of the reactive term in the equations for the fluctuations is a self-consistently determined constant. Elimination of the fluctuating part of the concentration field from the dynamics leads to a renormalized equation involving the average concentration field. It is shown that the noise leads to a renormalized (generally smaller) diffusion coefficient and renormalized kinetics. Within the framework of the approximations used, numerical simulations are in agreement with our theory. We show that the porosity fluctuations may have a significant effect on the transport of a reactive species, even in the case of a homogeneous average porosity.

  8. Vacuum electronics

    CERN Document Server

    Eichmeier, Joseph A


    Nineteen experts from the electronics industry, research institutes and universities have joined forces to prepare this book. ""Vacuum Electronics"" covers the electrophysical fundamentals, the present state of the art and applications, as well as the future prospects of microwave tubes and systems, optoelectronics vacuum devices, electron and ion beam devices, light and X-ray emitters, particle accelerators and vacuum interrupters. These topics are supplemented by useful information about the materials and technologies of vacuum electronics and vacuum technology.

  9. Investigation of the Ionospheric Fluctuations Caused by Space Weather Effects Using GNSS TEC Measurements (United States)

    Shagimuratov, Irk; Krankowski, Andrzej; Cherniak, Iurii; Ephishov, Ivan; Zakharenkova, Irina; Yakimova, Galina


    It is known that GPS radio signals passing through the ionosphere suffer varying degrees of rapid variations of their amplitude and phase - signal scintillations. The scintillations are caused by the presence of wide range of scale size irregularities in the ionosphere. It is very important to estimate scintillation and phase fluctuation effects on GNSS navigation system (GPS/GLONASS) performance and consequently on the precession of the obtained position. Effects of the ionospheric irregularities on the GPS signals can be evaluated by measurements of the differential phase time rate of dual frequency GPS signals. GPS observations carried out at the Arctic IGS (International GNSS Service) stations were used to study the development of TEC fluctuations in the high latitude ionosphere. Standard GPS measurements with 30s sampling rate allow the detection of middle- and large-scale ionospheric irregularities. For detection of ionospheric fluctuations the rate of TEC (ROT, in the unit of TECU/min) at 1 min interval was used. The temporal occurrence of TEC fluctuations is clearly observed in time variations in the dual frequency carrier phase along satellite passes. As a measure of the fluctuation activity level the Rate of TEC Index (ROTI) based on standard deviation of ROT was also used. ROTI was estimated in 10-minute interval. These techniques and IGS data were used to study the occurrence of TEC fluctuations at the northern latitude ionosphere for selected geomagnetic storms occurred at the end of 23rd and beginning of new 24th solar cycles. Results demonstrate that fluctuation activity of GPS signals in the high latitude ionosphere is depended on geomagnetic conditions. Intensity of fluctuations essentially increases during geomagnetic storms. The strongest TEC fluctuations occurred as short time rate of TEC enhancements of a factor of 2-5 relative to the quiet time. During geomagnetic disturbed conditions strong phase fluctuations can register at latitudes low

  10. Experimental Study of Magnetic Field Effect on dc Corona Discharge in Low Vacuum (United States)

    Elabbas, K.


    In the present paper, an attempt was made to investigate the effect of applying a transverse magnetic field on the dc corona discharge behavior in low vacuum. In general, two experiments were carried out in this work: the first is the ionization-region magnetic field experiment, and the second was the drift region magnetic field experiment. In these experiments, permanent magnets were used to produce magnetic field. The degree of vacuum used in this test was 0.4×105 Pa. It is found that the effect of the magnetic field increases as the degree of vacuum increases. It is also seen from this study that the corona current values are higher with magnetic fields than without magnetic fields. The experimental results indicate that the enhancement of the magnetic field near the wire discharge electrode has a significant influence on the increment of the discharge current. The effect of the magnetic field on the discharge current is the most significant with the negative corona discharges rather than with positive corona discharge. In contrast to, the curves were demonstrated that the application of magnetic fields in drift region magnetic field does not significantly change the corona discharge current. Discharge characteristics of magnetically enhanced corona discharges, extracted from this study, can be applied to various industrial applications, such as, in an electrostatic enhancement filter for the purpose of capturing fine particles, and as effective method for production of high ozone concentrations in a generator as compared to the ultraviolet (UV) radiation method.

  11. Simulating the effects of fluctuating dissolved oxygen on growth, reproduction, and survival of fish and shrimp. (United States)

    Miller Neilan, Rachael; Rose, Kenneth


    Individuals are commonly exposed to fluctuating levels of stressors, while most laboratory experiments focus on constant exposures. We develop and test a mathematical model for predicting the effects of low dissolved oxygen (hypoxia) on growth, reproduction, and survival using laboratory experiments on fish and shrimp. The exposure-effects model simulates the hourly reductions in growth and survival, and the reduction in reproduction (fecundity) at times of spawning, of an individual as it is exposed to constant or hourly fluctuating dissolved oxygen (DO) concentrations. The model was applied to seven experiments involving fish and shrimp that included constant and fluctuating DO exposures, with constant exposures used for parameter estimation and the model then used to simulate the growth, reproduction, and survival in the fluctuating treatments. Cumulative effects on growth, reproduction, and survival were predicted well by the model, but the model did not replay the observed episodic low survival days. Further investigation should involve the role of acclimation, possible inclusion of repair effects in reproduction and survival, and the sensitivity of model predictions to the shape of the immediate effects function. Additional testing of the model with other taxa, different patterns of fluctuating exposures, and different stressors is needed to determine the model's generality and robustness. © 2013 Elsevier Ltd. All rights reserved.


    Directory of Open Access Journals (Sweden)

    V. S. Doroshenko


    Full Text Available The review deals with the design flask tooling and patterns for effective hardening sand mixture in the vacuum molding (V-Process, and molding on a one-off patterns (Lost Foam Casting. Sealing and evacuating sand mixture – two major factors influence the strength of the casting mold and casting quality, management practices which will enable to improve the casting process.

  13. Effects of elevated vacuum on in-socket residual limb fluid volume: Case study results using bioimpedance analysis (United States)

    Sanders, JE; Harrison, DS; Myers, TR; Allyn, KJ


    Bioimpedance analysis was used to measure residual limb fluid volume on seven trans-tibial amputee subjects using elevated vacuum sockets and non-elevated vacuum sockets. Fluid volume changes were assessed during sessions with the subjects sitting, standing, and walking. In general, fluid volume losses during 3 or 5 min walks and losses over the course of the 30-min test session were less for elevated vacuum than for suction. A number of variables including the time of day data were collected, soft tissue consistency, socket-to-limb size differences and shape differences, and subject health may have affected the results and had an equivalent or greater impact on limb fluid volume compared with elevated vacuum. Researchers should well consider these variables in study design of future investigations on the effects of elevated vacuum on residual limb volume. PMID:22234667

  14. Structural-Acoustic Coupling Effects on the Non-Vacuum Packaging Vibratory Cylinder Gyroscope (United States)

    Xi, Xiang; Wu, Xuezhong; Wu, Yulie; Zhang, Yongmeng; Tao, Yi; Zheng, Yu; Xiao, Dingbang


    The resonant shells of vibratory cylinder gyroscopes are commonly packaged in metallic caps. In order to lower the production cost, a portion of vibratory cylinder gyroscopes do not employ vacuum packaging. However, under non-vacuum packaging conditions there can be internal acoustic noise leading to considerable acoustic pressure which is exerted on the resonant shell. Based on the theory of the structural-acoustic coupling, the dynamical behavior of the resonant shell under acoustic pressure is presented in this paper. A finite element (FE) model is introduced to quantitatively analyze the effect of the structural-acoustic coupling. Several main factors, such as sealing cap sizes and degree of vacuum which directly affect the vibration of the resonant shell, are studied. The results indicate that the vibration amplitude and the operating frequency of the resonant shell will be changed when the effect of structural-acoustic coupling is taken into account. In addition, an experiment was set up to study the effect of structural-acoustic coupling on the sensitivity of the gyroscope. A 32.4 mV/°/s increase of the scale factor and a 6.2 Hz variation of the operating frequency were observed when the radial gap size between the resonant shell and the sealing cap was changed from 0.5 mm to 20 mm. PMID:24351631

  15. Hemodynamic effects of the vacuum-assisted closure device on open mediastinal wounds. (United States)

    Conquest, Anne M; Garofalo, James H; Maziarz, David M; Mendelson, Kim G; Su Sun, You; Wooden, William A; Meadows, William M; Nifong, Wiley; Chitwood, W Randolph


    Application of the Vacuum-Assisted Closure device (VAC) to open sternal wounds has negative hemodynamic effects. We hypothesized that the interposition of a muscle flap attenuates these negative hemodynamic effects. After institutional approval, monitoring lines were placed in anesthetized, ventilated pigs. Through a median sternotomy, sonometric crystals were strategically positioned around the left ventricle. A rectus flap was rotated over the mediastinal wound, and the VAC was placed over the flap. After baseline measurements, a vacuum of 125 mmHg [Group (GP) 1, n = 5] or 50 mmHg (GP2, n = 6) was initiated. Hemodynamics were recorded every 15 min for 1.5 h, and 15 min after cessation of the vacuum therapy. GP3 (n = 6) underwent intermittent VAC cycling (on 5 min/off 2 min). Significance determined by t test. While non-flapped animals had significant detriment in both left ventricular filling volume and cardiac output, flapped animals had insignificant depression of both parameters. Application of muscle flaps to sternal wounds prior to VAC therapy significantly attenuates the negative hemodynamic effects seen when the VAC is used alone.

  16. Effect of dietary vitamin E supplementation on cholesterol oxidation in vacuum packaged cooked beef steaks. (United States)

    Galvin, K; Lynch, A M; Kerry, J P; Morrissey, P A; Buckley, D J


    The effect of dietary vitamin E supplementation on cholesterol oxidation in vacuum packaged, cooked, refrigerated and frozen beef steaks, was investigated. Steers (Friesian×Charolais×Black Hereford) were fed diets providing 20 or 3000 mg α-tocopheryl acetate/head/day for 135 days prior to slaughter. α-Tocopherol concentrations in M. psoas major (PM) and M. longissimus dorsi (LD) were significantly (poxidation (monitored by measuring 7-ketocholesterol formation) increased during refrigerated and frozen storage in some, but not all, groups, and tended to be higher in PM than LD. Dietary vitamin E did not affect 7-ketocholesterol formation in LD, but significantly (pvitamin E improved oxidative stability in both muscles. The results show that dietary vitamin E supplementation inhibits cholesterol oxidation in vacuum packaged, cooked beef during refrigerated and frozen storage, but may be influenced by muscle type.

  17. Wall shear stress fluctuations: Mixed scaling and their effects on velocity fluctuations in a turbulent boundary layer (United States)

    Diaz-Daniel, Carlos; Laizet, Sylvain; Vassilicos, J. Christos


    The present work investigates numerically the statistics of the wall shear stress fluctuations in a turbulent boundary layer (TBL) and their relation to the velocity fluctuations outside of the near-wall region. The flow data are obtained from a Direct Numerical Simulation (DNS) of a zero pressure-gradient TBL using the high-order flow solver Incompact3D [S. Laizet and E. Lamballais, "High-order compact schemes for incompressible flows: A simple and efficient method with quasi-spectral accuracy," J. Comput. Phys. 228(16), 5989 (2009)]. The maximum Reynolds number of the simulation is R e𝜃≈2000 , based on the free-stream velocity and the momentum thickness of the boundary layer. The simulation data suggest that the root-mean-squared fluctuations of the streamwise and spanwise wall shear-stress components τx and τz follow a logarithmic dependence on the Reynolds number, consistent with the empirical correlation of Örlü and Schlatter [R. Örlü and P. Schlatter, "On the fluctuating wall-shear stress in zero pressure-gradient turbulent boundary layer flows," Phys. Fluids 23, 021704 (2011)]. These functional dependencies can be used to estimate the Reynolds number dependence of the wall turbulence dissipation rate in good agreement with reference DNS data. Our results suggest that the rare negative events of τx can be associated with the extreme values of τz and are related to the presence of coherent structures in the buffer layer, mainly quasi-streamwise vortices. We also develop a theoretical model, based on a generalisation of the Townsend-Perry hypothesis of wall-attached eddies, to link the statistical moments of the filtered wall shear stress fluctuations and the second order structure function of fluctuating velocities at a distance y from the wall. This model suggests that the wall shear stress fluctuations may induce a higher slope in the turbulence energy spectra of streamwise velocities than the one predicted by the Townsend-Perry attached

  18. Asymptotics of QCD traveling waves with fluctuations and running coupling effects (United States)

    Beuf, Guillaume


    Extending the Balitsky-Kovchegov (BK) equation independently to running coupling or to fluctuation effects due to pomeron loops is known to lead in both cases to qualitative changes of the traveling-wave asymptotic solutions. In this paper we study the extension of the forward BK equation, including both running coupling and fluctuations effects, extending the method developed for the fixed coupling case [E. Brunet, B. Derrida, A.H. Mueller, S. Munier, Phys. Rev. E 73 (2006) 056126, cond-mat/0512021]. We derive the exact asymptotic behavior in rapidity of the probabilistic distribution of the saturation scale.

  19. Fluctuating functions related to quality of life in advanced Parkinson disease: effects of duodenal levodopa infusion. (United States)

    Isacson, D; Bingefors, K; Kristiansen, I S; Nyholm, D


    To assess fluctuations in quality of life (QoL) and motor performance in patients with advanced Parkinson disease (PD) treated with continuous daytime duodenal levodopa/carbidopa infusion or conventional therapy. Of 18 patients completing a 6-week trial (DIREQT), 12 were followed for up to 6 months and assessed using electronic diaries and the PD Questionnaire-39 (PDQ-39). During the trial and follow-up, major diurnal fluctuations were observed, especially for hyperkinesia, 'off' time, ability to walk and depression. Duodenal infusion was associated with significantly more favourable outcomes compared with conventional treatment for satisfaction with overall functioning, 'off' time and ability to walk, with improved outcomes with PDQ-39. Relative to conventional treatment, infusion therapy may stabilize and significantly improve motor function and patient's QoL. The potential for daily fluctuation in PD symptoms means single measures of treatment effectiveness can result in bias in effect estimates and hence repeated measures are recommended.

  20. The physical and physiological effects of vacuum massage on the different skin layers: a current status of the literature

    National Research Council Canada - National Science Library

    Moortgat, Peter; Anthonissen, Mieke; Meirte, Jill; Van Daele, Ulrike; Maertens, Koen


    .... Therefore, the aim of this review is to present an overview of the available literature on the physical and physiological effects of vacuum massage on epidermal and dermal skin structures in order...

  1. [Effects of vacuum sealing drainage technique in acute and chronic suppurative tenosynovitis of hand]. (United States)

    Wang, H; Xia, F; Xing, D M; Ren, D; Feng, W; Chen, Y; Xiao, Z H; Zhao, Z M


    Objective: To investigate the effects of vacuum sealing drainage technique in acute and chronic suppurative tenosynovitis of hand. Methods: A total of 9 cases acute and chronic suppurative tenosynovitis patients from January 2013 to April 2015 in Puai Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology were retrospectively reviewed. There were 6 males and 3 females, aging from 27 to 65 years, the average age was 55 years. There were 3 cases of index finger, 3 cases of middle finger, 2 cases of ring finger, 1 case include three fingers. The infection causes included stabbing with fishbone in 3 cases, stabbing with animal bone fragments in 3 cases, wound by sawdust in 3 cases, meat grinder injury in 1 case, multiple fingers crush injury postoperative infection of garbage truck in 1 case. Bacterial infection included 2 cases with Staphylococcus aureus, 2 cases with Staphylococcus epidermidis, 1 case with normal Escherichia coli, 1 case with mixed infection of Enterobacter aerogenes, Klebsiella oxytoca and Staphylococcus, 1 case with Bauman Acinetobacter bacillus, 1 case with Proteus mirabilis and 1 case of no growth of pathogenic bacteria culture. After thorough debridement, vacuum sealing drainage was used to observe the characteristics of irrigation fluid, the formation of cavity inflammation, the prognosis of infection and the recovery of finger function. Results: Seven patients with suppurative tenosynovitis were treated for 7 to 14 days, replaced the vacuum sealing drainage dressing once; 1 patient was an illustration of the finger tip defect flap infected patients after 21 days of treatment, replaced the vacuum sealing drainage dressing twice, 1 patient was an illustration of the central refers to trauma, postoperative infection patients 28 d, replaced three times in the VSD. The follow-up time was 3 to 12 months (mean 8.2 months), 7 patients without tendon necrosis, secondary suture with no infection, 2 cases of

  2. The Effect of Elevated Vacuum Suspension on Axial Bone-Socket Displacement in Persons with a Traumatic Transtibial Amputation (United States)


    The Effect of Elevated Vacuum Suspension on Axial Bone-Socket Displacement in Persons with a Traumatic Transtibial Amputation Benjamin J. Darter...78234, USA email: INTRODUCTION Following transtibial amputation prosthetic sockets must transfer forces from the...this study was to determine the effect of elevated vacuum on axial bone-socket motion in persons with a traumatic transtibial amputation (TTA) using DVF

  3. Vacuum extraction

    DEFF Research Database (Denmark)

    Maagaard, Mathilde; Oestergaard, Jeanett; Johansen, Marianne


    Objectives. To develop and validate an Objective Structured Assessment of Technical Skills (OSATS) scale for vacuum extraction. Design. Two part study design: Primarily, development of a procedure-specific checklist for vacuum extraction. Hereafter, validationof the developed OSATS scale for vacuum...

  4. Current fluctuation of electron and hole carriers in multilayer WSe{sub 2} field effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Seung-Pil; Shin, Jong Mok; Jang, Ho-Kyun; Jin, Jun Eon; Kim, Gyu-Tae, E-mail: [School of Electrical Engineering, Korea University, Seoul 02481 (Korea, Republic of); Kim, Yong Jin; Kim, Young Keun [Department of Materials Science and Engineering, Korea University, Seoul 02481 (Korea, Republic of); Shin, Minju [School of Electrical Engineering, Korea University, Seoul 02481 (Korea, Republic of); IMEP-LAHC, Grenoble INP-MINATEC, 3 Parvis Louis Neel, 38016 Grenoble (France)


    Two-dimensional materials have outstanding scalability due to their structural and electrical properties for the logic devices. Here, we report the current fluctuation in multilayer WSe{sub 2} field effect transistors (FETs). In order to demonstrate the impact on carrier types, n-type and p-type WSe{sub 2} FETs are fabricated with different work function metals. Each device has similar electrical characteristics except for the threshold voltage. In the low frequency noise analysis, drain current power spectral density (S{sub I}) is inversely proportional to frequency, indicating typical 1/f noise behaviors. The curves of the normalized drain current power spectral density (NS{sub I}) as a function of drain current at the 10 Hz of frequency indicate that our devices follow the carrier number fluctuation with correlated mobility fluctuation model. This means that current fluctuation depends on the trapping-detrapping motion of the charge carriers near the channel interface. No significant difference is observed in the current fluctuation according to the charge carrier type, electrons and holes that occurred in the junction and channel region.

  5. Anomalous Brownian motion of colloidal particle in a nematic environment: effect of the director fluctuations

    Directory of Open Access Journals (Sweden)

    T. Turiv


    Full Text Available As recently reported [Turiv T. et al., Science, 2013, Vol. 342, 1351], fluctuations in the orientation of the liquid crystal (LC director can transfer momentum from the LC to a colloid, such that the diffusion of the colloid becomes anomalous on a short time scale. Using video microscopy and single particle tracking, we investigate random thermal motion of colloidal particles in a nematic liquid crystal for the time scales shorter than the expected time of director fluctuations. At long times, compared to the characteristic time of the nematic director relaxation we observe typical anisotropic Brownian motion with the mean square displacement (MSD linear in time τ and inversly proportional to the effective viscosity of the nematic medium. At shorter times, however, the dynamics is markedly nonlinear with MSD growing more slowly (subdiffusion or faster (superdiffusion than τ. These results are discussed in the context of coupling of colloidal particle's dynamics to the director fluctuation dynamics.

  6. The effect of temperature fluctuations of reaction rate constants in turbulent reacting flows (United States)

    Chinitz, W.; Antaki, P. J.; Kassar, G. M.


    Current models of turbulent reacting flows frequently use Arrhenius reaction rate constants obtained from static or laminar flow theory and/or experiments, or from best fits of static, laminar, and turbulent data. By treating the reaction rate constant as a continuous random variable which is temperature-dependent, the present study assesses the effect of turbulent temperature fluctuations on the reaction rate constant. This model requires that a probability density function (PDF) describing the nature of the fluctuations be specified. Three PDFs are examined: the clipped Gaussian, the beta PDF, and the ramp model. All the models indicate that the reaction rate constant is greater in a turbulent flow field than in an equivalent laminar flow. In addition, an amplification ratio, which is the ratio of the turbulent rate constant to the laminar rate constant, is defined and its behavior as a function of the mean temperature fluctuations is described

  7. Quantifying the effect of trend, fluctuation, and extreme event of climate change on ecosystem productivity. (United States)

    Liu, Yupeng; Yu, Deyong; Su, Yun; Hao, Ruifang


    Climate change comprises three fractions of trend, fluctuation, and extreme event. Assessing the effect of climate change on terrestrial ecosystem requires an understanding of the action mechanism of these fractions, respectively. This study examined 11 years of remotely sensed-derived net primary productivity (NPP) to identify the impacts of the trend and fluctuation of climate change as well as extremely low temperatures caused by a freezing disaster on ecosystem productivity in Hunan province, China. The partial least squares regression model was used to evaluate the contributions of temperature, precipitation, and photosynthetically active radiation (PAR) to NPP variation. A climatic signal decomposition and contribution assessment model was proposed to decompose climate factors into trend and fluctuation components. Then, we quantitatively evaluated the contributions of each component of climatic factors to NPP variation. The results indicated that the total contribution of the temperature, precipitation, and PAR to NPP variation from 2001 to 2011 in Hunan province is 85 %, and individual contributions of the temperature, precipitation, and PAR to NPP variation are 44 % (including 34 % trend contribution and 10 % fluctuation contribution), 5 % (including 4 % trend contribution and 1 % fluctuation contribution), and 36 % (including 30 % trend contribution and 6 % fluctuation contribution), respectively. The contributions of temperature fluctuation-driven NPP were higher in the north and lower in the south, and the contributions of precipitation trend-driven NPP and PAR fluctuation-driven NPP are higher in the west and lower in the east. As an instance of occasionally triggered disturbance in 2008, extremely low temperatures and a freezing disaster produced an abrupt decrease of NPP in forest and grass ecosystems. These results prove that the climatic trend change brought about great impacts on ecosystem productivity and that climatic fluctuations and

  8. Effectiveness of Bench Top Non-Vacuum Autoclaves on Dental Turbine Chamber Sterilization Effectiveness of Bench Top Non-Vacuum Autoclaves on Dental Turbine Chamber Sterilization

    Directory of Open Access Journals (Sweden)

    Taraneh Movahhed


    Full Text Available Introduction: Dental turbine chamber is a suitable reservoir for living microorganisms, so chamber sterilization is necessary for reducing cross contamination risk. On the other hand, in non-vacuum autoclaves, steam penetration into turbine chamber is doubtful, while they are still in use in dental clinics. In this study, performance of small non-vacuum autoclave in turbine chamber sterilization was evaluated. Methods: A total of 48 dental turbines were sterilized by large vacuum autoclaves. The turbin chamber cap was opened in aseptic enviroment and a strip contaminated with bacillus stearothermophilus endospores was placed into chamber and chamber cap was closed. Twelve dental turbines were loaded in each of four autoclaves (2 large pre-vacuum autoclaves, 2 bench top non-vacuum autoclaves and sterilization process preformed according to the manufacturer's instructions. After the sterilization cycle, the strips were transferred to culture medium and incubated at 56°C for 48 Hours. As control sample, a biologic indicator that had not been autoclaved was used for each group. Results: Being loaded in different autoclaves, All 48 turbines were sterilized properly and all the cultures were negative. The culture results of four control indicators which were not sterilized, were positive. Conclusion: There was no difference between performance of vacuum and non-vacuum autoclaves in dental turbine chamber sterilization. Both types performed sterilization properly.

  9. Effects of inbreeding on survival, body weight and fluctuating asymmetry (FA) in Nile tilapia, Oreochromis niloticus

    NARCIS (Netherlands)

    Fessehaye, Y.; Komen, J.; Rezk, M.A.; Arendonk, van J.A.M.; Bovenhuis, H.


    The present study investigated the effects of different levels of inbreeding on survival, growth, body weight and fluctuating asymmetry (FA) in O. niloticus. We mated 20 sires and 35 dams in a full-sib/half-sib mating design to produce 35 full-sib families with expected level of inbreeding (F%.) of

  10. Orbital Effects of In-Plane Magnetic Fields Probed by Mesoscopic Conductance Fluctuations

    DEFF Research Database (Denmark)

    Zumbuhl, D.; Miller, Jessica; M. Marcus, C.


    We use the high sensitivity to magnetic flux of mesoscopic conductance fluctuations in large quantum dots to investigate changes in the two-dimensional electron dispersion caused by an in-plane magnetic field. In particular, changes in effective mass and the breaking of momentum reversal symmetry...

  11. Effect of dust size distribution and dust charge fluctuation on dust ion ...

    Indian Academy of Sciences (India)

    The effects of dust size distribution and dust charge fluctuation of dust grains on the small but finite amplitude nonlinear dust ion-acoustic shock waves, in an unmagnetized multi-ion dusty plasma which contains negative ions, positive ions and electrons, are studied in this paper. A Burgers equation and its stationary ...

  12. Vacuum stability with the effective six-pointed couplings of the Higgs bosons in the heavy supersymmetry (United States)

    Dubinin, Mikhail; Petrova, Elena


    Consistent and phenomenologically successful scenarios of the Minimal Supersymmetric Standard Model (MSSM) include the Higgs potential which is positively defined at large fields and has two minima, one of them is true and stable vacuum in which we live. However, the effective terms of the MSSM potential which appear at a loop level can spoil the vacuum stability leading to a metastable or unstable vacuum configurations. Such a situation is analysed and the general necessary conditions of vacuum stability in the MSSM parameter space are imposed. For a majority of the MSSM "benchmark scenarios" which are used for reconstruction of production channels at the LHC, the effective potential is found to be always stable, except light stop and τ-phobic scenarios.

  13. Vacuum stability with the effective six-pointed couplings of the Higgs bosons in the heavy supersymmetry

    Directory of Open Access Journals (Sweden)

    Dubinin Mikhail


    Full Text Available Consistent and phenomenologically successful scenarios of the Minimal Supersymmetric Standard Model (MSSM include the Higgs potential which is positively defined at large fields and has two minima, one of them is true and stable vacuum in which we live. However, the effective terms of the MSSM potential which appear at a loop level can spoil the vacuum stability leading to a metastable or unstable vacuum configurations. Such a situation is analysed and the general necessary conditions of vacuum stability in the MSSM parameter space are imposed. For a majority of the MSSM “benchmark scenarios” which are used for reconstruction of production channels at the LHC, the effective potential is found to be always stable, except light stop and τ-phobic scenarios.

  14. A comparison of the effect of conventional and filter vacuum cleaners on airborne house dust mite allergen. (United States)

    Hegarty, J M; Rouhbakhsh, S; Warner, J A; Warner, J O


    The efficiency (dust collection and recirculation) of a conventional upright vacuum cleaner with a prototype vacuum bag (I) with pore size of 0.1 micron was compared with a standard vacuum cleaner bag (II), in the homes of 11 atopic asthmatic subjects with a known allergy to house dust mite. Four filter vacuum cleaners were assessed in pairs-the Vax 2000 with the Vorwerk VK121 ET340 (in 10 homes), and the Nilfisk GS90 'Allergy Vac' with the Bosch maxima 43 (in nine homes). All of the selected homes were vacuumed throughout (carpets and soft furnishings) for a 15 min period with each of the cleaners, and air was sampled simultaneously at 21 min-1 (Casella personal sampler). The weight of dust retrieved was recorded, and a sample of sieved dust (2 g) and the air filters were extracted to determine the concentrations of the major allergen, Der pI, by ELISA (ALK). No significant difference was observed in either total weight of dust, or airborne and dust concentrations of Der pI between using the conventional cleaner with vacuum bags I, or vacuum bags II. The Vax and the Vorwerk filter vacuum cleaners produced no measurable airborne Der pI concentrations during use in any of the 10 homes tested, whilst the Nilfisk produced airborne Der pI in two, and the Bosch in one of the nine homes tested. The Vorwerk retrieved significantly more dust from the floors than the Vax (P vacuum cleaners investigated produced lower concentrations of airborne Der pI, compared to the conventional cleaner with or without a special dust bag. However, the amount of dust and concentration/amount of Der pI that these cleaners actually retrieved, varied and the Vorwerk appeared most effective overall.

  15. Simulation analysis of within-day flow fluctuation effects on trout below flaming Gorge Dam.

    Energy Technology Data Exchange (ETDEWEB)

    Railsback, S. F.; Hayse, J. W.; LaGory, K. E.; Environmental Science Division; EPRI


    In addition to being renewable, hydropower has the advantage of allowing rapid load-following, in that the generation rate can easily be varied within a day to match the demand for power. However, the flow fluctuations that result from load-following can be controversial, in part because they may affect downstream fish populations. At Flaming Gorge Dam, located on the Green River in northeastern Utah, concern has been raised about whether flow fluctuations caused by the dam disrupt feeding at a tailwater trout fishery, as fish move in response to flow changes and as the flow changes alter the amount or timing of the invertebrate drift that trout feed on. Western Area Power Administration (Western), which controls power production on submonthly time scales, has made several operational changes to address concerns about flow fluctuation effects on fisheries. These changes include reducing the number of daily flow peaks from two to one and operating within a restricted range of flows. These changes significantly reduce the value of the power produced at Flaming Gorge Dam and put higher load-following pressure on other power plants. Consequently, Western has great interest in understanding what benefits these restrictions provide to the fishery and whether adjusting the restrictions could provide a better tradeoff between power and non-power concerns. Directly evaluating the effects of flow fluctuations on fish populations is unfortunately difficult. Effects are expected to be relatively small, so tightly controlled experiments with large sample sizes and long study durations would be needed to evaluate them. Such experiments would be extremely expensive and would be subject to the confounding effects of uncontrollable variations in factors such as runoff and weather. Computer simulation using individual-based models (IBMs) is an alternative study approach for ecological problems that are not amenable to analysis using field studies alone. An IBM simulates how a

  16. Extra-dimensional curvature suppression of the effective four-dimensional vacuum energy density (United States)

    Guendelman, E. I.


    Considering a very large number of extra dimensions, N → ∞, we show that in the effective four-dimensional picture, to leading order in N, both the cosmological constant in N + 4 dimensions and the curvature of the extra dimensions (curved as spheres) give the same type of contributions. Furthermore, in this limit, the extra-dimensional curvature naturally suppresses the effect of a positive cosmological constant, so that the resulting effective potential governing the vacuum energy in the effective 4 - D picture has a leading 1/N dependence (i.e. vanishing in the large N limit). We can understand qualitatively this effect in a heuristic picture by thinking that both visible and extra dimensions have an equal sharing of the curvature caused by Λ. In this case when increasing the overall number of dimensions by adding N extra dimensions, then if N is large, the visible dimensions do not have to curve too much; hence, a small four-dimensional vacuum energy follows. In the large N picture, the potential can also be stabilized by a small (i.e. vanishing at large N) expectation value of a four-index field strength.

  17. Extra Dimensional Curvature Supression of the Effective Four Dimensional Vacuum Energy Density

    CERN Document Server

    Guendelman, E I


    Considering a very large number of extra dimensions, $N\\rightarrow \\infty$, we show that in the effective four dimensional picture, to leading order in $N$, both the cosmological constant in $N+4$ dimensions and the curvature of the extra dimensions (curved as spheres) give the same type of contributions. Furthermore in this limit, the extra dimensional curvature naturally supress the effect of a positive Cosmological Constant, so that the resulting effective potential governing the vacuum energy in the effective $4-D$ picture has a leading 1/N dependence (i.e. vanishing in the large $N$ limit). We can understand qualitatively this effect in a heuristic picture, by thinking that all dimensions, both visible and extra have an equal sharing of the curvature caused by $\\Lambda$, in this case when increasing the overall number of dimensions by adding $N$ extra dimensions, then if $N$ is large, the visible dimensions do not have to curve too much, hence a small four dimensional vacuum energy follows. In the large ...

  18. Effects of sound level fluctuations on annoyance caused by aircraft-flyover noise (United States)

    Mccurdy, D. A.


    A laboratory experiment was conducted to determine the effects of variations in the rate and magnitude of sound level fluctuations on the annoyance caused by aircraft-flyover noise. The effects of tonal content, noise duration, and sound pressure level on annoyance were also studied. An aircraft-noise synthesis system was used to synthesize 32 aircraft-flyover noise stimuli representing the factorial combinations of 2 tone conditions, 2 noise durations, 2 sound pressure levels, 2 level fluctuation rates, and 2 level fluctuation magnitudes. Thirty-two test subjects made annoyance judgements on a total of 64 stimuli in a subjective listening test facility simulating an outdoor acoustic environment. Variations in the rate and magnitude of level fluctuations were found to have little, if any, effect on annoyance. Tonal content, noise duration, sound pressure level, and the interaction of tonal content with sound pressure level were found to affect the judged annoyance significantly. The addition of tone corrections and/or duration corrections significantly improved the annoyance prediction ability of noise rating scales.

  19. Effects of fluctuating temperature and food availability on reproduction and lifespan. (United States)

    Schwartz, Tonia S; Pearson, Phillip; Dawson, John; Allison, David B; Gohlke, Julia M


    Experimental studies on energetics and aging often remove two major factors that in part regulate the energy budget in a normal healthy individual: reproduction and fluctuating environmental conditions that challenge homeostasis. Here we use the cyclical parthenogenetic Daphnia pulex to evaluate the role of a fluctuating thermal environment on both reproduction and lifespan across six food concentrations. We test the hypotheses that (1) caloric restriction extends lifespan; (2) maximal reproduction will come with a cost of shortened lifespan; and (3) at a given food concentration, relative to a metabolically equivalent constant temperature environment a diel fluctuating thermal environment will alter the allocation of energy to reproduction and lifespan to maintain homeostasis. We did not identify a level of food concentration that extended lifespan in response to caloric restriction, and we found no cost of reproduction in terms of lifespan. Rather, the individuals at the highest food levels generally had the highest reproductive output and the longest lifespans, the individuals at the intermediate food level decreased reproduction and maintained lifespan, and the individuals at the three lower food concentrations had a decrease in reproduction and lifespan as would be predicted with increasing levels of starvation. Fluctuating temperature had no effect on lifespan at any food concentration, but delayed time to reproductive maturity and decreased early reproductive output at all food concentrations. This suggests that a fluctuating temperature regimen activates molecular pathways that alter energy allocation. The costs of fluctuating temperature on reproduction were not consistent across the lifespan. Statistical interactions for age of peak reproduction and lifetime fecundity suggest that senescence of the reproductive system may vary between temperature regimens at the different food concentrations. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. The effect of bright light exposure on pupillary fluctuations in healthy subjects. (United States)

    Szabó, Zoltán; Tokaji, Zsolt; Kálmán, János; Oroszi, László; Pestenácz, Anikó; Janka, Zoltán


    Light therapy is thought to be the first choice treatment of winter depression. However, its way of action is poorly understood. In order to find a solid effect of bright artificial light, we studied its possible alerting action through the spontaneous fluctuations of the pupil, considered to be an objective measurement of vigilance. Pupillary fluctuations of 10 healthy subjects (mean age: 22+/-1 S.D. years) were measured for 60 s before and 15 min after 0.5 h, 10000-lux light exposure. The cumulative change in pupil size, characterised by the pupillary unrest index (PUI) decreased at each subject, and this decrease was in average 35+/-4.4% S.E.M. The average pupillary diameters were unchanged (101+/-2.2% S.E.M.). This analysis revealed that the slow components of the pupillary fluctuations also decreased considerably. There was no dim light or other placebo control of the light treatment. Bright light exposure significantly influenced the pupillary fluctuations. We suppose that bright light exposure increases the level of alertness, and this could be a possible way by which bright artificial light exerts a beneficial effect also in affective disorders.

  1. Effect of vacuum and thermal shock on laser treatment of Trichophyton rubrum (toenail fungus) (United States)

    Aguilar, Guillermo; Sun, Feng; Carlier, Pierre; Young, Erica; Hennings, David; González, F. Javier


    The eradication of Trichophyton rubrum has been attempted via laser irradiation because it could result advantageous relative to current clinical therapies. Anticipating that the necessary thermal effects could unintentionally damage the underlying toe dermal layer, we have explored two auxiliary approaches: (a) laser irradiation under vacuum pressure, with and without water dousing and, (b) cooling followed by laser heating (thermal shock). The rationale is that at low pressures, the temperature necessary to achieve water evaporation/boiling is significantly reduced, thus requiring lower fluences. Similarly, a thermal shock induced by cooling followed by laser irradiation may require lower fluences to achieve fungus necrosis. For all experiments presented we use a Cooltouch, model CT3 plus, 1320 nm laser to irradiate fungi colonies. The vacuum pressure experiments exposed fungi colonies to a subatmospheric pressure of 84.7 kPa (25 inHg) with and without water dousing for 5 min, followed by irradiation with 4.0 J/cm2 fluence and 40-90 J total energies. The thermal shock experiments consisted of three sections at 4.8 J/cm2: cooling the fungus to 0 °C at 0.39 °C/min and then irradiating to 45-60 °C cooling to -20 °C at 1.075 °C/min and irradiating to 45 °C and cooling to -20 °C at 21.5 °C/min and irradiating to 45 °C. Fungus growth rate over a 1-week period assessed the feasibility of these procedures. Results indicated both approaches hamper the growth rate of fungi colonies relative to untreated control samples, especially water dousing under vacuum conditions and slow cooling rate preceding irradiation for thermal shock effect.

  2. The hydrodynamic basis of the vacuum cleaner effect in continuous-flow PCNL instruments: an empiric approach and mathematical model. (United States)

    Mager, R; Balzereit, C; Gust, K; Hüsch, T; Herrmann, T; Nagele, U; Haferkamp, A; Schilling, D


    Passive removal of stone fragments in the irrigation stream is one of the characteristics in continuous-flow PCNL instruments. So far the physical principle of this so-called vacuum cleaner effect has not been fully understood yet. The aim of the study was to empirically prove the existence of the vacuum cleaner effect and to develop a physical hypothesis and generate a mathematical model for this phenomenon. In an empiric approach, common low-pressure PCNL instruments and conventional PCNL sheaths were tested using an in vitro model. Flow characteristics were visualized by coloring of irrigation fluid. Influence of irrigation pressure, sheath diameter, sheath design, nephroscope design and position of the nephroscope was assessed. Experiments were digitally recorded for further slow-motion analysis to deduce a physical model. In each tested nephroscope design, we could observe the vacuum cleaner effect. Increase in irrigation pressure and reduction in cross section of sheath sustained the effect. Slow-motion analysis of colored flow revealed a synergism of two effects causing suction and transportation of the stone. For the first time, our model showed a flow reversal in the sheath as an integral part of the origin of the stone transportation during vacuum cleaner effect. The application of Bernoulli's equation provided the explanation of these effects and confirmed our experimental results. We widen the understanding of PCNL with a conclusive physical model, which explains fluid mechanics of the vacuum cleaner effect.

  3. Effects of pressure fluctuations on the combustion process in turbulent premixed flames (United States)

    Beardsell, Guillaume; Lapointe, Simon; Blanquart, Guillaume


    The need for a thorough understanding of turbulence-combustion interactions in compressible flows is driven by recent technological developments in propulsion as well as renewed interest in the development of next generation supersonic and hypersonic vehicles. In such flows, pressure fluctuations displaying a wide range of length and timescales are present. These fluctuations are expected to impact the combustion process to varying degrees, depending amongst other things on the amplitude of the pressure variations and the timescales of the chemical reactions taking place in the flame. In this context, numerical simulations of these flows can provide insight into the impact of pressure fluctuations on the combustion process. In the present work, we analyze data from simulations of statistically-flat premixed n-heptane/air flames at high Karlovitz numbers. The compressible Navier-Stokes equations are solved exactly (DNS) and results obtained with both detailed kinetic modeling and one-step chemistry are considered. The effects of pressure fluctuations on the fuel burning rate are investigated. The findings are compared with results obtained from simulations of one-dimensional premixed flames subjected to various pressure waves.

  4. VACUUM TRAP (United States)

    Gordon, H.S.


    An improved adsorption vacuum trap for use in vacuum systems was designed. The distinguishing feature is the placement of a plurality of torsionally deformed metallic fins within a vacuum jacket extending from the walls to the central axis so that substantially all gas molecules pass through the jacket will impinge upon the fin surfaces. T fins are heated by direct metallic conduction, thereby ol taining a uniform temperature at the adeorbing surfaces so that essentially all of the condensible impurities from the evacuating gas are removed from the vacuum system.

  5. Quantum vacuum effects on the final fate of a collapsing ball of dust (United States)

    Arfaei, Hessamaddin; Noorikuhani, Milad


    We consider the quantum vacuum effects of the massless scalar fields that are non-minimally coupled to the background geometry of a collapsing homogeneous ball of dust. It is shown that for a definite range of coupling constants, there are repulsive quantum vacuum effects, capable of stopping the collapse process inside the black hole and precluding the formation of singularity. The final fate of the collapse will be a black hole with no singularity, inside which the matter stays balanced. The density of the final static matter will be close to the Planck density. We show that the largest possible radius of the stable static ball inside a black hole with Schwarzschild mass M is given by {(1/90πM/m_p)}^{1/3}{ℓ}_p . If the black hole undergoes Hawking radiation, the final state will be an extremal quantum-corrected black hole, with zero temperature, with a remnant of matter inside. We show that the resolution of singularity is not disrupted under Hawking radiation.

  6. Effect of Vacuum Intrusion Compaction on the Mechanical Properties of Mortar

    Directory of Open Access Journals (Sweden)

    Chung K.Y.


    Full Text Available The Vacuum Intrusion Compaction Method (VICM can be defined as a mortar or cement based material compaction method which applies the principle of air pressure in extracting air bubbles trapped in mortar in order to achieve the objective of compaction. This alternative compaction method is able to prevent segregation from happening in mortar and other cement based materials. It also provides better control over the orientation of the elements inside the mortar. Laboratory tests on the physical and mechanical properties of mortars were conducted to study bulk density, porosity, compressive strength, and flexural strength in the early stages of strength development of different mortars. Through such testing, the effectiveness of the vacuum intrusion method on the effect of compaction could be observed. The outcome of this research shows that the VICM is capable of compacting mortar and extracting macro pores, thereby providing a relatively similar compressive strength and flexural strength to that of the standard compaction method. However, it is not efficient in extracting micro pores, therefore, leading to high porosity of the mortar specimens. As a conclusion, the vibration compaction method is still considered a good compaction method when compared to VICM.

  7. Density Fluctuation in Aqueous Solutions and Molecular Origin of Salting-Out Effect for CO2. (United States)

    Ho, Tuan Anh; Ilgen, Anastasia


    Using molecular dynamics simulation, we studied the density fluctuations and cavity formation probabilities in aqueous solutions and their effect on the hydration of CO 2 . With increasing salt concentration, we report an increased probability of observing a larger than the average number of species in the probe volume. Our energetic analyses indicate that the van der Waals and electrostatic interactions between CO 2 and aqueous solutions become more favorable with increasing salt concentration, favoring the solubility of CO 2 (salting in). However, due to the decreasing number of cavities forming when salt concentration is increased, the solubility of CO 2 decreases. The formation of cavities was found to be the primary control on the dissolution of gas, and is responsible for the observed CO 2 salting-out effect. Our results provide the fundamental understanding of the density fluctuation in aqueous solutions and the molecular origin of the salting-out effect for real gas.

  8. The cost effectiveness of vacuum-assisted versus core-needle versus surgical biopsy of breast lesions. (United States)

    Fernández-García, P; Marco-Doménech, S F; Lizán-Tudela, L; Ibáñez-Gual, M V; Navarro-Ballester, A; Casanovas-Feliu, E

    To determine the cost effectiveness of breast biopsy by 9G vacuum-assisted guided by vertical stereotaxy or ultrasonography in comparison with breast biopsy by 14G core-needle biopsy and surgical biopsy. We analyzed a total of 997 biopsies (181 vacuum-assisted, 626 core, and 190 surgical biopsies). We calculated the total costs (indirect and direct) of the three types of biopsy. We did not calculate intangible costs. We measured the percentage of correct diagnoses obtained with each technique. To identify the most cost-effective option, we calculated the mean ratios for the three types of biopsies. Total costs were €225.09 for core biopsy, €638.90 for vacuum-assisted biopsy, and €1780.01 for surgical biopsy. The overall percentage of correct diagnoses was 91.81% for core biopsy, 94.03% for vacuum-assisted biopsy, and 100% for surgical biopsy; however, these differences did not reach statistical significance (p=0.3485). For microcalcifications, the percentage of correct diagnoses was 50% for core biopsy and 96.77% for vacuum-assisted biopsy (p<0.0001). For nodules, there were no significant differences among techniques. The mean cost-effectiveness ratio considering all lesions was 2.45 for core biopsy, 6.79 for vacuum-assisted biopsy, and 17.80 for surgical biopsy. Core biopsy was the dominant option for the diagnosis of suspicious breast lesions in general. However, in cases with microcalcifications, the low percentage of correct diagnoses achieved by core biopsy (50%) advises against its use in this context, where vacuum-assisted biopsy would be the technique of choice because it is more cost-effective than surgical biopsy, the other technique indicated for biopsying microcalcifications. Copyright © 2016 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

  9. Effect of postural change on intraocular pressure fluctuation in open angle glaucoma patients after trabeculectomy

    Directory of Open Access Journals (Sweden)

    Wei Li


    Full Text Available AIM:To study the effect of postural change on intraocular pressure(IOPfluctuation in open angle glaucoma patients after trabeculectomy, and to discuss the value of this investigation on prognosis. METHODS: Fifty-one cases(62 eyesof primary open angle glaucoma were selected as the research object. Perkins ophthalmotonometer was used to test IOP at the time when patient seat(first seat. The patients were asked to lie supine for 25min, detected IOP, and the patients seated again(final seat, sustaining for 15min, detected IOP. According to whether the IOP range was more than 5mmHg, they were divided into high volatility fluctuation group and low volatility fluctuation group. We recorded their visual field progression(with AGIS score, HPA staging, in order to evaluate the correlation of IOP range with them. Reviews were made 3mo a time, and lasted for 1a, in order to evaluate the relation between IOP range and AGIS scores.RESULTS: The IOP of first seat was 18.1+2.2mmHg. There was no significant difference in the same position(P>0.05. The IOP range was 4.1±1.5mmHg. Low volatility fluctuation group was more likely to have low AGIS score and to be early vision HPA(PPr=0.412, PPCONCLUSION: Visual field progression is related to the degree of IOP fluctuation in open angle glaucoma patients after trabeculectomy, so we can predict the prognosis of patients simply by detect IOP fluctuation. This is good to adjust the IOP control scheme.

  10. Experimental and theoretical analyses of temperature polarization effect in vacuum membrane distillation

    KAUST Repository

    Alsaadi, Ahmad Salem


    This paper discusses the effect of temperature polarization in Vacuum Membrane Distillation (VMD). The main motivation for using VMD in this work is that this module configuration is much simpler and more suitable for this kind of investigation than the other MD configurations such as Direct Contact Membrane Distillation (DCMD). The coupling between heat and mass transfer mechanisms at the feed-membrane interface is presented from a theoretical point of view. In addition, a new simple graphical method and a mathematical model for determining VMD flux are presented. The two methods used in evaluating the extent of temperature polarization effect on water vapor flux (flux sensitivity factors and temperature polarization coefficient (TPC)) are also analyzed and compared. The effect of integrating a heat recovery system in a large scale module on the TPC coefficient has also been studied and presented in this paper. © 2014 Elsevier B.V.

  11. Effect of vacuum and modified atmosphere packaging on microbiological properties of cold-smoked trout (United States)

    Đorđević, J.; Pavlićević, N.; Bošković, M.; Janjić, J.; Glišić, M.; Starčević, M.; Baltić, M. Ž.


    Because of the importance of different packaging methods for the extension of fish shelf life, as a highly perishable food, the aim of the present study was to examine the effect of vacuum and modified atmosphere packaging on the total Enterobacteriaceae and lactic acid bacteria counts of cold-smoked Salmon trout (Oncorhynchus mykiss) stored at 3°C during six weeks. Trout fillets were vacuumed packaged (VP) or packaged in one of two different modified atmospheres, with gas ratio of 50%CO2/50%N2 (MAP1) and 90%CO2/10%N2 (MAP2) and analysed on days 0, 7, 14, 21, 28, 35 and 42. Both the total Enterobacteriaceae and total lactic acid bacteria counts increased in the trout fillets in all packaging types during storage. A significantly lower total Enterobacteriaceae count was determined in the MAP fish compared to the VP fish, with the weakest growth rate and lowest numbers attained in MAP2 fillets. The lactic acid bacteria count was higher in trout packaged in MAP compared to VP, with the highest number in the MAP with 90% CO2 (MAP2).

  12. Effects of operating parameters and fluid properties on the efficiency of a new vacuum evaporation method

    Directory of Open Access Journals (Sweden)

    Rösti Johannes


    Full Text Available A new process for vacuum evaporation was developed where evaporation takes place near the inner surface of a vortex as produced by a rotor submerged in the liquid. Contrary to the state of the art the new process does not need a vacuum vessel but the rotating liquid creates a geometrically stable low pressure void surrounded by a vortex stabilized by the equilibrium between centrifugal forces and the pressure difference. First tests with water and sugar solutions at concentrations similar to wine must showed evaporation rates in the upper range of thin-film evaporators. A test series was conducted to study the effect of the variation of process parameters. The heating power and thus the fluid temperature has the most important influence on the vaporisation rate. A second test series using sucrose solution of different concentration comes to the conclusion that this method is suitable for aqueous solutions but the vapour production rate drops significantly with increased sugar content using the current rotor design. The simplicity of the construction and the process handling make this new method a promising development for the wine production.

  13. Effect of Thermal Fluctuations on the Radiative Rate in Core/Shell Quantum Dots. (United States)

    Balan, Arunima D; Eshet, Hagai; Olshansky, Jacob H; Lee, Youjin V; Rabani, Eran; Alivisatos, A Paul


    The effect of lattice fluctuations and electronic excitations on the radiative rate is demonstrated in CdSe/CdS core/shell spherical quantum dots (QDs). Using a combination of time-resolved photoluminescence spectroscopy and atomistic simulations, we show that lattice fluctuations can change the radiative rate over the temperature range from 78 to 300 K. We posit that the presence of the core/shell interface plays a significant role in dictating this behavior. We show that the other major factor that underpins the change in radiative rate with temperature is the presence of higher energy states corresponding to electron excitation into the shell. These effects should be present in other core/shell samples and should also affect other excited state rates, such as the rate of Auger recombination or the rate of charge transfer.

  14. Vacuum mechatronics (United States)

    Hackwood, Susan; Belinski, Steven E.; Beni, Gerardo


    The discipline of vacuum mechatronics is defined as the design and development of vacuum-compatible computer-controlled mechanisms for manipulating, sensing and testing in a vacuum environment. The importance of vacuum mechatronics is growing with an increased application of vacuum in space studies and in manufacturing for material processing, medicine, microelectronics, emission studies, lyophylisation, freeze drying and packaging. The quickly developing field of vacuum mechatronics will also be the driving force for the realization of an advanced era of totally enclosed clean manufacturing cells. High technology manufacturing has increasingly demanding requirements for precision manipulation, in situ process monitoring and contamination-free environments. To remove the contamination problems associated with human workers, the tendency in many manufacturing processes is to move towards total automation. This will become a requirement in the near future for e.g., microelectronics manufacturing. Automation in ultra-clean manufacturing environments is evolving into the concept of self-contained and fully enclosed manufacturing. A Self Contained Automated Robotic Factory (SCARF) is being developed as a flexible research facility for totally enclosed manufacturing. The construction and successful operation of a SCARF will provide a novel, flexible, self-contained, clean, vacuum manufacturing environment. SCARF also requires very high reliability and intelligent control. The trends in vacuum mechatronics and some of the key research issues are reviewed.

  15. Effects of a fluctuating water table : Column study on redox dynamics and fate of some organic pollutants

    NARCIS (Netherlands)

    Sinke, A.J.C.; Dury, O.; Zobrist, J.


    The development of the redox conditions has been studied in an initially aerobic column filled with quartz sand coated with ferrihydrite and subjected to a fluctuating water table. The purpose of this study was to evaluate the effect of water table fluctuations on the redox dynamics and the fate of

  16. Thermal fluctuations and effective bending stiffness of elastic thin sheets and graphene: A nonlinear analysis (United States)

    Ahmadpoor, Fatemeh; Wang, Peng; Huang, Rui; Sharma, Pradeep


    The study of statistical mechanics of thermal fluctuations of graphene-the prototypical two-dimensional material-is rendered rather complicated due to the necessity of accounting for geometric deformation nonlinearity. Unlike fluid membranes such as lipid bilayers, coupling of stretching and flexural modes in solid membranes like graphene leads to a highly anharmonic elastic Hamiltonian. Existing treatments draw heavily on analogies in the high-energy physics literature and are hard to extend or modify in the typical contexts that permeate materials, mechanics and some of the condensed matter physics literature. In this study, using a variational perturbation method, we present a ;mechanics-oriented; treatment of the thermal fluctuations of elastic sheets such as graphene and evaluate their effect on the effective bending stiffness at finite temperatures. In particular, we explore the size, pre-strain and temperature dependency of the out-of-plane fluctuations, and demonstrate how an elastic sheet becomes effectively stiffer at larger sizes. Our derivations provide a transparent approach that can be extended to include multi-field couplings and anisotropy for other 2D materials. To reconcile our analytical results with atomistic considerations, we also perform molecular dynamics simulations on graphene and contrast the obtained results and physical insights with those in the literature.

  17. The effect of dust charge fluctuations in the near-Enceladus plasma (United States)

    Yaroshenko, Victoria; Luehr, Hermann

    The geologically active moon Enceladus feeds the most extended, Saturns’ E ring by dust particles and creates a specific multispecies plasma environment -the Enceladus plasma torus. The key process of dust-plasma interactions is dust charging. The grain electrostatic potential in space is usually calculated from the so called orbit-motion limited (OML) model [1]. It is valid for a single particle immersed into collisionless plasmas with Maxwellian electron and ion distributions. Such a parameter regime cannot be directly applied to the conditions relevant for the Enceladus plasma environment and especially, for the dense plume region, where the dust density is high, sometimes even exceeding the plasma number density. Generalizing the OML formalism, we examine several new factors that can significantly affect the equilibrium grain charging: (a) multispecies composition of the core plasma, including hot electrons and newborn cold ions; (b) effect of high dust number density (c) the role of dust size distributions. We also focus on such a specific peculiarity of dust charging as charge fluctuations. Since the grain charges are not fixed and can fluctuate, this introduces the crucial difference between ordinary plasma species (electrons and ions) and charged dust particles. There are two reasons for such fluctuations. The charging of the grains depends on the local plasma characteristics, and thus some temporal or spatial variations in the plasma parameters ultimately modify numbers of charges acquired by a grain. Some of these effects related to the near-Enceladus plasma environment have recently been discussed [2]. A second reason for charge fluctuations is the discrete nature of the charge carriers. Electrons and ions are absorbed or emitted by the grain surface randomly thus leading to stochastic fluctuations of the dust net charge. These fluctuations exist always even in a steady-state uniform plasma, and we discuss the statistical characteristics of random dust

  18. Modeling of effect of LC SLM phase fluctuations on kinoforms optical reconstruction quality (United States)

    Cheremkhin, Pavel A.; Evtikhiev, Nikolay N.; Krasnov, Vitaly V.; Rodin, Vladislav G.; Starikov, Sergey N.


    Phase-only liquid crystal (LC) spatial light modulators (SLM) are actively used in various applications. However, majority of scientific applications require stable phase modulation which might be hard to achieve with commercially available SLM due to its consumer origin. The use of digital voltage addressing scheme leads to phase temporal fluctuations, which results in lower diffraction efficiency and reconstruction quality of displayed diffractive optical elements (DOE). It is often preferable to know effect of these fluctuations on DOE reconstruction quality before SLM is implemented into experimental setup. It is especially important in case of multi-level phaseonly DOE such as kinoforms. Therefore we report results of modeling of effect of phase fluctuations of LC SLM "HoloEye PLUTO VIS" on kinoforms optical reconstruction quality. Modeling was conducted in the following way. First dependency of LC SLM phase shift on addressed signal level and time from frame start was measured for all signal values (0-255) with temporal resolution of 0.5 ms in time period of one frame. Then numerical simulation of effect of SLM phase fluctuations on kinoforms reconstruction quality was performed. Based on measured dependency, for each time delay new distorted kinoform was generated and then numerically reconstructed. Averaged reconstructed image corresponds to optically reconstructed one with registration time exceeding time period of one frame (16.7 ms), while individual images correspond to momentary optical reconstruction with registration time less than 1 ms. Quality degradation of modeled optical reconstruction of several test kinoforms was analyzed. Comparison of kinoforms optical reconstruction with SLM and numerically simulated reconstruction was conducted.

  19. The effect of interaural-level-difference fluctuations on the externalization of sound

    DEFF Research Database (Denmark)

    Catic, Jasmina; Santurette, Sébastien; Buchholz, Jörg M.


    in a standard listening room. Next, the effect of ILD fluctuations on the degree of externalization was investigated in a psychoacoustic experiment performed in the same listening room. Individual binaural impulse responses were used to simulate a distant sound source delivered via headphones. The ILDs were......Real-world sound sources are usually perceived as externalized and thus properly localized in both direction and distance. This is largely due to (1) the acoustic filtering by the head, torso, and pinna, resulting in modifications of the signal spectrum and thereby a frequency-dependent shaping...... with the analysis of short-term ILDs at different distances showing that a decreased distance to the sound source also reduced the ILD fluctuations. © 2013 Acoustical Society of America....

  20. Development of a Monte-Carlo based method for calculating the effect of stationary fluctuations

    DEFF Research Database (Denmark)

    Pettersen, E. E.; Demazire, C.; Jareteg, K.


    This paper deals with the development of a novel method for performing Monte Carlo calculations of the effect, on the neutron flux, of stationary fluctuations in macroscopic cross-sections. The basic principle relies on the formulation of two equivalent problems in the frequency domain: one...... that corresponds to the real part of the neutron balance, and one that corresponds to the imaginary part. The two equivalent problems are in nature similar to two subcritical systems driven by external neutron sources, and can thus be treated as such in a Monte Carlo framework. The definition of these two...... part of the neutron balance plays a significant role and for driving fluctuations leading to neutron sources having the same sign in the two equivalent sub-critical problems. A semi-analytical diffusion-based solution is used to verily the implementation of the method on a test case representative...

  1. Effect of mesoscopic fluctuations on equation of state in cluster-forming systems

    Directory of Open Access Journals (Sweden)

    A. Ciach


    Full Text Available Equation of state for systems with particles self-assembling into aggregates is derived within a mesoscopic theory combining density functional and field-theoretic approaches. We focus on the effect of mesoscopic fluctuations in the disordered phase. The pressure - volume fraction isotherms are calculated explicitly for two forms of the short-range attraction long-range repulsion potential. Mesoscopic fluctuations lead to an increased pressure in each case, except for very small volume fractions. When large clusters are formed, the mechanical instability of the system is present at much higher temperature than found in mean-field approximation. In this case phase separation competes with the formation of periodic phases (colloidal crystals. In the case of small clusters, no mechanical instability associated with separation into dilute and dense phases appears.

  2. Effects of thermal fluctuations on non-minimal regular magnetic black hole (United States)

    Jawad, Abdul; Shahzad, M. Umair


    We analyze the effects of thermal fluctuations on a regular black hole (RBH) of the non-minimal Einstein-Yang-Mill theory with gauge field of magnetic Wu-Yang type and a cosmological constant. We consider the logarithmic corrected entropy in order to analyze the thermal fluctuations corresponding to non-minimal RBH thermodynamics. In this scenario, we develop various important thermodynamical quantities, such as entropy, pressure, specific heats, Gibb's free energy and Helmholtz free energy. We investigate the first law of thermodynamics in the presence of logarithmic corrected entropy and non-minimal RBH. We also discuss the stability of this RBH using various frameworks such as the γ factor (the ratio of heat capacities), phase transition, grand canonical ensemble and canonical ensemble. It is observed that the non-minimal RBH becomes globally and locally more stable if we increase the value of the cosmological constant.

  3. Effects of thermal fluctuations on non-minimal regular magnetic black hole

    Energy Technology Data Exchange (ETDEWEB)

    Jawad, Abdul [COMSATS Institute of Information Technology, Department of Mathematics, Lahore (Pakistan); Shahzad, M.U. [COMSATS Institute of Information Technology, Department of Mathematics, Lahore (Pakistan); University of Central Punjab, CAMS, UCP Business School, Lahore (Pakistan)


    We analyze the effects of thermal fluctuations on a regular black hole (RBH) of the non-minimal Einstein-Yang-Mill theory with gauge field of magnetic Wu-Yang type and a cosmological constant. We consider the logarithmic corrected entropy in order to analyze the thermal fluctuations corresponding to non-minimal RBH thermodynamics. In this scenario, we develop various important thermodynamical quantities, such as entropy, pressure, specific heats, Gibb's free energy and Helmholtz free energy. We investigate the first law of thermodynamics in the presence of logarithmic corrected entropy and non-minimal RBH. We also discuss the stability of this RBH using various frameworks such as the γ factor (the ratio of heat capacities), phase transition, grand canonical ensemble and canonical ensemble. It is observed that the non-minimal RBH becomes globally and locally more stable if we increase the value of the cosmological constant. (orig.)

  4. The effect of density fluctuations on electron cyclotron beam broadening and implications for ITER (United States)

    Snicker, A.; Poli, E.; Maj, O.; Guidi, L.; Köhn, A.; Weber, H.; Conway, G.; Henderson, M.; Saibene, G.


    We present state-of-the-art computations of propagation and absorption of electron cyclotron waves, retaining the effects of scattering due to electron density fluctuations. In ITER, injected microwaves are foreseen to suppress neoclassical tearing modes (NTMs) by driving current at the q=2 and q=3/2 resonant surfaces. Scattering of the beam can spoil the good localization of the absorption and thus impair NTM control capabilities. A novel tool, the WKBeam code, has been employed here in order to investigate this issue. The code is a Monte Carlo solver for the wave kinetic equation and retains diffraction, full axisymmetric tokamak geometry, determination of the absorption profile and an integral form of the scattering operator which describes the effects of turbulent density fluctuations within the limits of the Born scattering approximation. The approach has been benchmarked against the paraxial WKB code TORBEAM and the full-wave code IPF-FDMC. In particular, the Born approximation is found to be valid for ITER parameters. In this paper, we show that the radiative transport of EC beams due to wave scattering in ITER is diffusive unlike in present experiments, thus causing up to a factor of 2–4 broadening in the absorption profile. However, the broadening depends strongly on the turbulence model assumed for the density fluctuations, which still has large uncertainties.

  5. Effects of the amplitude and frequency of salinity fluctuations on antioxidant responses in juvenile tongue sole, Cynoglossus semilaevis

    Energy Technology Data Exchange (ETDEWEB)

    Khairnar, S.A.; Tian, X.; Dong, S.; Fang, Z.; Solanki, B.V.; Shanthanagouda, H.A.


    To understand the tolerance of tongue sole, Cynoglossus semilaevis, to varying salinities, the effects of the amplitude (2, 4, 6 and 8 g/L) and frequency (2, 4 and 8 days) of salinity fluctuations on the activities of antioxidant responses, including acidic phosphatase (ACP), alkaline phosphatase (AKP), catalase (CAT) and superoxide dismutase (SOD) from antioxidant system in liver, muscle, gills and kidney were investigated in this study. The results showed that the antioxidant responses of tongue sole were highly tissue-specific during the varying salinity fluctuations. In all tissues, ACP and AKP activity was found to be highest at moderate salinity fluctuations compared to the control, low and high salinity treatments (p<0.05). SOD and CAT activities had significant effect due to salinity fluctuations in all tissues (p<0.05), except in hepatic and renal tissues. Variations in branchial SOD activity proved that salinity fluctuations had greater impact on tongue sole at moderate and high fluctuating salinities compared to the control and low fluctuating salinities, whereas the branchial CAT activities showed contrasting trend. Further, cortisol levels were significantly affected in lower and higher salinity fluctuations. However, plasma cortisol levels remained low in moderate salinity fluctuations and control (p<0.05). Taken together, the results indicated that salinity fluctuations could effectively stimulate and enhance the antioxidant enzyme activity in the liver, kidney, gills and muscle of the juvenile tongue sole, thus effectively eliminating the excessive reactive oxygen species and minimizing the body damage in tongue sole or could be for any other euryhaline teleosts. (Author)

  6. Effect of vacuum packaging and pomegranate peel extract on quality aspects of ground goat meat and nuggets. (United States)

    Devatkal, Suresh K; Thorat, Pramod; Manjunatha, M


    The effect of vacuum packaging and pomegranate peel extract on ground goat meat and cooked nuggets during refrigerated storage (4 ± 1 °C) was evaluated. Three different treatments evaluated were: I). Aerobic packaging (AP); II) Vacuum packaging (VP) and III). Vacuum packaging along with 1 % pomegranate peel extract (VP + PPE). Results of quality evaluation showed that VP and VP + PPE maintained a more stable colour than AP. In all treatments, a significant (P nuggets was observed during the storage. But, VP nuggets showed minimum changes in texture parameters. TBARS values were significantly (P nuggets, TBARS was decreased by 17 % and 40 % in VP and VP + PPE respectively. Total plate counts were significantly higher (>log 7) in AP than VP meat and nuggets. Thus VP and PPE have a synergistic antioxidant effect and VP extended the refrigerated shelf life of goat meat and nuggets.

  7. Impacts of friction stir processing on irradiation effects in vacuum-plasma-spray coated tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Ozawa, Kazumi, E-mail: [Fusion Research and Development Directorate, Japan Atomic Energy Agency, 2-166 Obuchi-Omotedate, Rokkasho, Aomori 039-3212 (Japan); Tanigawa, Hiroyasu [Fusion Research and Development Directorate, Japan Atomic Energy Agency, 2-166 Obuchi-Omotedate, Rokkasho, Aomori 039-3212 (Japan); Morisada, Yoshiaki; Fujii, Hidetoshi [Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan)


    In order to examine the impacts of friction stir processing (FSP) on irradiation effects in vacuum-plasma-spray (VPS) coated tungsten (W), nano indentation hardness was evaluated of three kinds of W materials after self-ion-irradiation to 5.0–5.4 dpa at 500 and 800 °C. The VPS-FSP clearly got grains refined and isotropic compared to bulk-W and the as-VPS-W. Nano indentation hardness remains unchanged for the as-VPS-W and VPS-FSP × 2-W irradiated to 5.4 dpa at 500 °C and it decreased from 1 dpa at 800 °C, while typical irradiation induced hardening was observed for the bulk-W irradiated at 500 °C.

  8. The effect of laser wavelength on the delay time of laser triggered vacuum switch (United States)

    Xin, Yinan; He, Zhenghao; Liu, Yuchen


    The study on the influence of laser wavelength on the initial plasma properties of laser-triggered vacuum switch (LTVS) is not only beneficial to understanding the trigger mechanism but also to optimizing its design for miniaturization and generalization. In this paper, the one-dimensional heat conduction model of the target was developed and then the effect of laser wavelength on the depth of laser ablation and the quantity of initial plasma were investigated experimentally and theoretically with the laser absorption rate. The theoretical analysis was in good agreement with experimental measurement of the delay time of the LTVS. It is clear that the shorter the wavelength, the shorter the delay time will be after the LTVS is triggered.

  9. Treatment of heavy-metal wastewater by vacuum membrane distillation: effect of wastewater properties (United States)

    Ji, Zhongguang


    Heavy metal wastewater is a common byproduct in heavy metal industries. Membrane distillation is considered as promising technology to treat such wastewater. The treatment of heavy metal wastewater by vacuum membrane distillation (VMD) was conducted in this work. The effects of pH, calcium and EDTA on VMD performance were investigated. VMD process showed a good acid resistance as the solution pH above 0. When the solution pH was 0, the permeate conductivity was below 40μS·cm-1. Calcium and EDTA were found to have influence on VMD performance to some extent. VMD process was proved to be suitable for heavy metal wastewater as long as the impurity content was in control of a certain degree.

  10. Quantum Prisoners' Dilemma in Fluctuating Massless Scalar Field (United States)

    Huang, Zhiming


    Quantum systems are easily affected by external environment. In this paper, we investigate the influences of external massless scalar field to quantum Prisoners' Dilemma (QPD) game. We firstly derive the master equation that describes the system evolution with initial maximally entangled state. Then, we discuss the effects of a fluctuating massless scalar field on the game's properties such as payoff, Nash equilibrium, and symmetry. We find that for different game strategies, vacuum fluctuation has different effects on payoff. Nash equilibrium is broken but the symmetry of the game is not violated.

  11. Effect of river flow fluctuations on riparian vegetation dynamics: Processes and models (United States)

    Vesipa, Riccardo; Camporeale, Carlo; Ridolfi, Luca


    Several decades of field observations, laboratory experiments and mathematical modelings have demonstrated that the riparian environment is a disturbance-driven ecosystem, and that the main source of disturbance is river flow fluctuations. The focus of the present work has been on the key role that flow fluctuations play in determining the abundance, zonation and species composition of patches of riparian vegetation. To this aim, the scientific literature on the subject, over the last 20 years, has been reviewed. First, the most relevant ecological, morphological and chemical mechanisms induced by river flow fluctuations are described from a process-based perspective. The role of flow variability is discussed for the processes that affect the recruitment of vegetation, the vegetation during its adult life, and the morphological and nutrient dynamics occurring in the riparian habitat. Particular emphasis has been given to studies that were aimed at quantifying the effect of these processes on vegetation, and at linking them to the statistical characteristics of the river hydrology. Second, the advances made, from a modeling point of view, have been considered and discussed. The main models that have been developed to describe the dynamics of riparian vegetation have been presented. Different modeling approaches have been compared, and the corresponding advantages and drawbacks have been pointed out. Finally, attention has been paid to identifying the processes considered by the models, and these processes have been compared with those that have actually been observed or measured in field/laboratory studies.

  12. Effect of ECH on Turbulent Fluctuations During ITER Baseline Discharges on DIII D (United States)

    Marinoni, A.; Rost, J. C.; Porkolab, M.; Davis, E. M.; Pinsker, R. I.; Burrell, K. H.; DIII-D Team


    Recent experiments on the DIII-D tokamak simulating the ITER Baseline Scenario show that torque-free and spatially localized Electron Cyclotron Heating (ECH), compared to neutral beam heating, modifies flow shear and density fluctuations, resulting in a slightly worse confinement degradation than that given by the IPB98(y,2) scaling. After turning off ECH, the Phase Contrast Imaging diagnostic measures, on confinement time scales, a decrease in the intensity of fluctuations at frequencies lower than 200 kHz, consistent with the mean flow shear exceeding the maximum linear growth rate of ITG modes. In contrast, at higher frequencies the intensity of fluctuations increases promptly, due to ETG modes enhanced by the prompt increase of the electron temperature inverse scale length in the outer third of the minor radius. The latter effect is seen in preliminary non-linear gyro-kinetic simulations to generate a larger transient heat flux and an inward particle pinch. Work supported by the US DOE under DE-FG02-94ER54235 and DE-FC02-04ER54698.

  13. Algorithmic modeling of the irrelevant sound effect (ISE) by the hearing sensation fluctuation strength. (United States)

    Schlittmeier, Sabine J; Weissgerber, Tobias; Kerber, Stefan; Fastl, Hugo; Hellbrück, Jürgen


    Background sounds, such as narration, music with prominent staccato passages, and office noise impair verbal short-term memory even when these sounds are irrelevant. This irrelevant sound effect (ISE) is evoked by so-called changing-state sounds that are characterized by a distinct temporal structure with varying successive auditory-perceptive tokens. However, because of the absence of an appropriate psychoacoustically based instrumental measure, the disturbing impact of a given speech or nonspeech sound could not be predicted until now, but necessitated behavioral testing. Our database for parametric modeling of the ISE included approximately 40 background sounds (e.g., speech, music, tone sequences, office noise, traffic noise) and corresponding performance data that was collected from 70 behavioral measurements of verbal short-term memory. The hearing sensation fluctuation strength was chosen to model the ISE and describes the percept of fluctuations when listening to slowly modulated sounds (f(mod) < 20 Hz). On the basis of the fluctuation strength of background sounds, the algorithm estimated behavioral performance data in 63 of 70 cases within the interquartile ranges. In particular, all real-world sounds were modeled adequately, whereas the algorithm overestimated the (non-)disturbance impact of synthetic steady-state sounds that were constituted by a repeated vowel or tone. Implications of the algorithm's strengths and prediction errors are discussed.

  14. Effects of Demographic Noise on the Synchronization of a Metapopulation in a Fluctuating Environment

    KAUST Repository

    Lai, Yi Ming


    We use the theory of noise-induced phase synchronization to analyze the effects of demographic noise on the synchronization of a metapopulation of predator-prey systems within a fluctuating environment (Moran effect). Treating each local predator-prey population as a stochastic urn model, we derive a Langevin equation for the stochastic dynamics of the metapopulation. Assuming each local population acts as a limit cycle oscillator in the deterministic limit, we use phase reduction and averaging methods to derive the steady-state probability density for pairwise phase differences between oscillators, which is then used to determine the degree of synchronization of the metapopulation. © 2011 American Physical Society.

  15. The effect of fluctuating temperatures during development on fitness-related traits of Scatophaga stercoraria (Diptera: Scathophagidae). (United States)

    Kjærsgaard, Anders; Pertoldi, Cino; Loeschcke, Volker; Blanckenhorn, Wolf U


    Development of ectotherms is highly temperature dependent. Studies using variable thermal environments can improve ecological relevance of data because organisms naturally face day-to-day stochastic temperature fluctuations as well as seasonal changes in the amplitude of such daily fluctuations. The objective of this study was to investigate if, and to what extent, the use of constant temperatures is justified in studies of the model species, yellow dung fly, Scatophaga stercoraria (L.). We examined the effect of temperature fluctuation on the expression of several life history traits and the effect on subsequent adult longevity. We used two fluctuating temperature treatments with the same mean but different amplitudes (15/21°C, 12/24°C; 12/12 h), and three constant temperature treatments spanning the wide temperature range faced in the wild (12, 18, and 24°C). Large temperature fluctuation was mostly detrimental (lower juvenile survival, slower growth, smaller body size, and longer development), whereas moderate temperature fluctuation usually gave responses similar to the constant regime. When developing in fluctuating temperatures, adult longevity (no effect), body size (lower), and wing shape (narrower wings) deviated from the expectations based on the constant temperature reaction norms, presumably because of acclimation responses. Contrary to some studies no obvious beneficial effects of moderate temperature fluctuation were observed. Instead, yellow dung flies seem to canalize development in the face of temperature fluctuation up to a point when detrimental effects become unavoidable. The relatively greater effects of extreme constant developmental temperatures question their biological relevance in experiments.

  16. Ultra high vacuum technology

    CERN Multimedia

    CERN. Geneva


    A short introduction for some basic facts and equations. Subsquently, discussion about: Building blocks of an ultrahigh vacuum system - Various types of pumps required to reach uhv and methods to reduce these effects - Outgassing phenomena induced by the presence of a particle beam and the most common methods to reduce these effects It will be given some practical examples from existing CERN accelerators and discuss the novel features of the future LHC vacuum system.

  17. Cosmic vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Chernin, Artur D [P.K. Shternberg State Astronomical Institute at the M.V. Lomonosov Moscow State University, Moscow (Russian Federation)


    Recent observational studies of distant supernovae have suggested the existence of cosmic vacuum whose energy density exceeds the total density of all the other energy components in the Universe. The vacuum produces the field of antigravity that causes the cosmological expansion to accelerate. It is this accelerated expansion that has been discovered in the observations. The discovery of cosmic vacuum radically changes our current understanding of the present state of the Universe. It also poses new challenges to both cosmology and fundamental physics. Why is the density of vacuum what it is? Why do the densities of the cosmic energy components differ in exact value but agree in order of magnitude? On the other hand, the discovery made at large cosmological distances of hundreds and thousands Mpc provides new insights into the dynamics of the nearby Universe, the motions of galaxies in the local volume of 10 - 20 Mpc where the cosmological expansion was originally discovered. (reviews of topical problems)

  18. Synchrotron Vacuum Ultraviolet Light and Soft X-Ray Radiation Effects on Aluminized Teflon FEP Investigated (United States)

    Dever, Joyce A.; Townsend, Jacqueline A.; Gaier, James R.; Jalics, Alice I.


    Since the Hubble Space Telescope (HST) was deployed in low Earth orbit in April 1990, two servicing missions have been conducted to upgrade its scientific capabilities. Minor cracking of second-surface metalized Teflon FEP (DuPont; fluorinated ethylene propylene) surfaces from multilayer insulation (MLI) was first observed upon close examination of samples with high solar exposure retrieved during the first servicing mission, which was conducted 3.6 years after deployment. During the second HST servicing mission, 6.8 years after deployment, astronaut observations and photographic documentation revealed significant cracks in the Teflon FEP layer of the MLI on both the solar- and anti-solar-facing surfaces of the telescope. NASA Goddard Space Flight Center directed the efforts of the Hubble Space Telescope MLI Failure Review Board, whose goals included identifying the low-Earth-orbit environmental constituent(s) responsible for the cracking and embrittling of Teflon FEP which was observed during the second servicing mission. The NASA Lewis Research Center provided significant support to this effort. Because soft x-ray radiation from solar flares had been considered as a possible cause for the degradation of the mechanical properties of Teflon FEP (ref. 1), the effects of soft xray radiation and vacuum ultraviolet light on Teflon FEP were investigated. In this Lewisled effort, samples of Teflon FEP with a 100-nm layer of vapor-deposited aluminum (VDA) on the backside were exposed to synchrotron radiation of various vacuum ultraviolet and soft x-ray wavelengths between 18 nm (69 eV) and 0.65 nm (1900 eV). Synchrotron radiation exposures were conducted using the National Synchrotron Light Source at Brookhaven National Laboratory. Samples of FEP/VDA were exposed with the FEP surface facing the synchrotron beam. Doses and fluences were compared with those estimated for the 20-yr Hubble Space Telescope mission.

  19. Vacuum II

    CERN Document Server

    Franchetti, G


    This paper continues the presentation of pumps begun in ‘Vacuum I’. The main topic here is gauges and partial-pressure measurements. Starting from the kinetics of gases, the various strategies for measuring vacuum pressures are presented at an introductory level, with some reference to hardware devices. Partial-pressure measurement techniques are introduced, showing that the principles of ion selection have a direct similarity to particle dynamics in accelerators.

  20. Effects of plasma and vacuum-ultraviolet exposure on the mechanical properties of low-k porous organosilicate glass (United States)

    X. Guo; J.E. Jakes; S. Banna; Y. Nishi; J.L. Shohet


    The effects of plasma exposure and vacuum-ultraviolet (VUV) irradiation on the mechanical properties of low-k porous organosilicate glass (SiCOH) dielectric films were investigated. Nanoindentation measurements were made on SiCOH films before and after exposure to an electron-cyclotron-resonance plasma or a monochromatic synchrotron VUV beam, to determine the changes...

  1. Vacuum phenomenon. (United States)

    Yanagawa, Youichi; Ohsaka, Hiromichi; Jitsuiki, Kei; Yoshizawa, Toshihiko; Takeuchi, Ikuto; Omori, Kazuhiko; Oode, Yasumasa; Ishikawa, Kouhei


    This article describes the theory of the formation of the vacuum phenomenon (VP), the detection of the VP, the different medical causes, the different locations of the presentation of the VP, and the differential diagnoses. In the human body, the cavitation effect is recognized on radiological studies; it is called the VP. The mechanism responsible for the formation of the VP is as follows: if an enclosed tissue space is allowed to expand as a rebound phenomenon after an external impact, the volume within the enclosed space will increase. In the setting of expanding volume, the pressure within the space will decrease. The solubility of the gas in the enclosed space will decrease as the pressure of the space decreases. Decreased solubility allows a gas to leave a solution. Clinically, the pathologies associated with the VP have been reported to mainly include the normal joint motion, degeneration of the intervertebral discs or joints, and trauma. The frequent use of CT for trauma patients and the high spatial resolution of CT images might produce the greatest number of chances to detect the VP in trauma patients. The VP is observed at locations that experience a traumatic impact; thus, an analysis of the VP may be useful for elucidating the mechanism of an injury. When the VP is located in the abdomen, it is important to include perforation of the digestive tract in the differential diagnosis. The presence of the VP in trauma patients does not itself influence the final outcome.

  2. The effects of solvent on the conformation and the collective motions of protein: Normal mode analysis and molecular dynamics simulations of melittin in water and in vacuum (United States)

    Kitao, Akio; Hirata, Fumio; Gō, Nobuhiro


    The effects of solvent on the conformation and dynamics of protein is studied by computer simulation. The dynamics is studied by focusing mainly on collective motions of the protein molecule. Three types of simulation, normal mode analysis, molecular dynamics in vacuum, and molecular dynamics in water are applied to melittin, the major component of bee venom. To define collective motions principal, component analysis as well as normal mode analysis has been carried out. The principal components with large fluctuation amplitudes have a very good correspondence with the low-frequency normal modes. Trajectories of the molecular dynamics simulation are projected onto the principal axes. From the projected motions time correlation functions are calculated. The results indicate that the very-low-frequency modes, whose frequencies are less than ≈ 50 cm -1, are overdamping in water with relaxation times roushly twice as long as the period of the oscillatory motion. Effective Langevin mode analysis is carried out by using the friction coefficient matrix determined from the velocity correlation function calculated from the molecular dynamics trajectory in water. This analysis reproduces the results of the simulation in water reasonably well. The presence of the solvent water is found also to affect the shape of the potential energy surface in such a way that it produces many local minima with low-energy barriers in between, the envelope of which is given by the surface in vacuum. Inter-minimum transitions endow the conformational dynamics of proteins in water another diffusive character, which already exists in the intra-minimum collective motions.

  3. A New Fluctuating Asymmetry Index, or the Solution for the Scaling Effect?

    Directory of Open Access Journals (Sweden)

    Cino Pertoldi


    Full Text Available Two principal methods are commonly employed for the estimation of developmental instability at the population level. Some studies use variances of morphological traits (σ2p, while others use fluctuating asymmetry (FA. In both cases, differences in the degree of developmental instability can be tested with an F-test, which is the most common way to compare variances. However, the variance is expected to scale proportionally to the square of the mean as there is a tendency in biological data for σ2p to scale proportionally to the square of the mean ( : σ2p = Z ξ, where ξ is the scaling exponent, which is expected to be two for pure statistical reasons,  is the mean of the trait and Z is a measure of individual-level variability. Because of this scaling effect, the fluctuating asymmetry will be affected, FA is estimated as the variance between the right and the left sides of a trait (σ2r − l = σ2r + σ2l − 2rσrσl, where σ2r and σ2l are the variances of the right and the left trait values, respectively. In this paper, we propose a novel method that allows an exact correction of the scaling effect, which will enable a proper comparison of the degree of fluctuating asymmetry for a trait. The problem of the scaling of the FA with the trait size is quite crucial if FA is to be considered an indicator of fitness or an indicator of environmental or genetic stress, as different stresses or fitness levels are typically accompanied by a change of the traits’ .

  4. Spiral multiple-effect diffusion solar still coupled with vacuum-tube collector and heat pipe

    KAUST Repository

    Huang, Bin-Juine


    © 2015 Elsevier B.V. A novel solar still with spiral-shape multiple-effect diffusion unit is developed in the present study. The test results of a 14-effect unit coupled with vacuum-tube solar collector (absorber area 1.08m2) show that the highest daily pure water production is 40.6kgd-1. The measured highest productivity based on the area of glass cover, solar absorber, and evaporating surface is 34.7, 40.6, and 7.96kgm-2d-1, respectively, which are much higher than the published results. The measured solar distillation efficiency is 2.0-3.5. The performance enhancement results mainly from the lateral diffusion process in the spiraled still cell. The vapor flow generated by heat input can flow freely and laterally through the spiral channel down to the end when solar heat input is high. Besides, the larger evaporating and condensing area at the outer cell may increase heat and mass transfer at the outer cell.

  5. Multiple-effect diffusion solar still coupled with a vacuum-tube collector and heat pipe

    KAUST Repository

    Chong, Tze-Ling


    The present study develops a multiple-effect diffusion solar still (MEDS) with a bended-plate design in multiple-effect diffusion unit (MDU) to solve the peel-off problem of wick material. The MDU is coupled with a vacuum-tube solar collector to produce a high temperature gradient for high productivity. A heat pipe is used to transfer the solar heat to the MDU. A prototype MEDS-1L was built and tested outdoors. Four performance indexes are proposed for the performance evaluation of MEDS, including daily pure water production per unit area of glass cover, solar absorber, and evaporating surface (Mcov, Msol, Mevp, respectively), and solar distillation efficiency Rcov. The outdoor test results of MEDS-1L show that the solar collector supply temperature Th reaches 100°C at solar radiation 800Wm-2. The highest Mcov is 23.9kgm-2d-1 which is about 29% higher than the basin-type MEDS [11]. The highest value is 25.9kgm-2d-1 for Msol and 2.79kgm-2d-1 for Mevp. The measured Rcov is 1.5-2.44, higher than the basin-type MEDS (1.45-1.88). The Mcov, Msol, Mevp and Rcov of MEDS-1L are all higher than the theoretical calculation of a MEDS with a flat-plate solar collector coupled with a heat pipe (MEDS-FHP) [17].© 2014 Elsevier B.V.

  6. The effects of fluctuating temperature regimes on the embryonic development of lake whitefish (Coregonus clupeaformis). (United States)

    Lim, Michael Y-T; Manzon, Richard G; Somers, Christopher M; Boreham, Douglas R; Wilson, Joanna Y


    Fluctuating incubation temperatures may have significant effects on fish embryogenesis; yet most laboratory-based studies use constant temperatures. For species that experience large, natural seasonal temperature changes during embryogenesis, such as lake whitefish (Coregonus clupeaformis), seasonal temperature regimes are likely optimal for development. Anthropogenic activities can increase average and/or variability of natural incubation temperatures over large (e.g. through climate change) or smaller (e.g. thermal effluent discharge) geographic scales. To investigate this, we incubated lake whitefish embryos under constant (2, 5, or 8°C) and fluctuating temperature regimes. Fluctuating temperature regimes had a base temperature of 2°C with: 1) seasonal temperature changes that modeled natural declines/inclines; 2) tri-weekly +3°C, 1h temperature spikes; or 3) both seasonal temperature changes and temperature spikes. We compared mortality to hatch, morphometrics, and heart rate at three developmental stages. Mortality rate was similar for embryos incubated at constant 2°C, constant 5°C, or with seasonal temperatures, but was significantly greater at constant 8°C. Embryos incubated constantly at >2°C had reduced body growth and yolk consumption compared to embryos incubated with seasonal temperature changes. When measured at the common base temperature of 2°C, embryos incubated at constant 2°C had lower heart rates than embryos incubated with both seasonal temperature changes and temperature spikes. Our study suggests that incubating lake whitefish embryos with constant temperatures may significantly alter development, growth, and heart rate compared to incubating with seasonal temperature changes, emphasizing the need to include seasonal temperature changes in laboratory-based studies. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. The effect of substrate concentration fluctuation on the performance of high-rate denitrifying reactor. (United States)

    Li, Wei; Zheng, Ping; Zhang, Jiqiang; Shan, Xiaoyu; Wang, Zhiyao; Zhang, Meng


    A high-rate denitrifying process is sensitive to the operation conditions and the substrate concentration fluctuation can lead to the deterioration or even collapse of process performance. The results of this study showed that the effect of substrate concentration fluctuation on the high-rate denitrification process was related to the substrate concentration and shock duration. The effect of substrate concentration was greater than that of shock duration and nitrate conversion was more sensitive than methanol conversion. The response of denitrification performance was related to the loading saturation (maximum loading rate/loading capacity ratio). When the loading saturation was lower than 32%, the high-rate denitrification process could stay in pseudo steady state, otherwise it would easily lose stability. The response of denitrification performance could be divided into three periods. The performance deterioration of high-rate denitrifying process could be attributed to the overload trigger and the toxicity of free nitrous acid. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. The effect of vacuum frying on starch gelatinization and its in vitro digestibility in starch-gluten matrices. (United States)

    Contardo, Ingrid; Parada, Javier; Leiva, Angel; Bouchon, Pedro


    Starch digestibility in a food matrix depends on processing conditions that may affect its physical state and microstructure. Starch gelatinization is one critical change that takes place during frying which could be affected during low-pressure processing. This study assessed the effect of vacuum frying on starch gelatinization and its in vitro digestibility. Laminated dough was made of a reconstituted blend of wheat starch (88% d.b.) and gluten (12% d.b.). Samples were fried under vacuum (6.5 kPa, Twater-boiling-point=38°C) or atmospheric conditions up to bubble-end point, maintaining a thermal driving force of 70°C (Toil-Twater-boiling-point=70°C). Vacuum fried samples showed less starch gelatinization (28%), less rapidly available glucose (27%), and more unavailable glucose (70%) than their atmospheric counterparts (which presented 99% starch gelatinization, 40% rapidly available glucose, and 46% unavailable glucose), and the values were close to those of raw dough. These results show how vacuum processing may be used to control the degree of starch gelatinization and related digestibility. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. The clinical efficacy and cost effectiveness of the vacuum-assisted closure technique in the management of acute and chronic wounds: A randomized controlled trial

    NARCIS (Netherlands)

    Braakenburg, A.; Obdeijn, M.C.; Feitz, R.; van Rooij, I.A.L.M.; van Griethuysen, A.J.; Klinkenbijl, J.H.G.


    Background: Vacuum-assisted closure therapy is a relatively new concept described in the literature that increases wound-healing capacity. The authors aimed to investigate the effect of vacuum-assisted closure therapy on wound healing, granulation tissue formation, bacterial clearance, pain, time

  10. The clinical efficacy and cost effectiveness of the vacuum-assisted closure technique in the management of acute and chronic wounds : A randomized controlled trial

    NARCIS (Netherlands)

    Braakenburg, Assa; Obdeijn, Miryam C.; Feitz, Reinier; van Rooij, Iris A. L. M.; van Griethuysen, Arjanne J.; Klinkenbijl, Jean H. G.

    Background: Vacuum-assisted closure therapy is a relatively new concept described in the literature that increases wound-healing capacity. The authors aimed to investigate the effect of vacuum-assisted closure therapy on wound healing, granulation tissue formation, bacterial clearance, pain, time

  11. The effect of vacuum packaging on histamine changes of milkfish sticks at various storage temperatures

    Directory of Open Access Journals (Sweden)

    Hsien-Feng Kung


    Full Text Available The effects of polyethylene packaging (PEP (in air and vacuum packaging (VP on the histamine related quality of milkfish sticks stored at different temperatures (−20°C, 4°C, 15°C, and 25°C were studied. The results showed that the aerobic plate count (APC, pH, total volatile basic nitrogen (TVBN, and histamine contents increased as storage time increased when the PEP and VP samples were stored at 25°C. At below 15°C, the APC, TVBN, pH, and histamine levels in PEP and VP samples were retarded, but the VP samples had considerably lower levels of APC, TVBN, and histamine than PEP samples. Once the frozen fish samples stored at −20°C for 2 months were thawed and stored at 25°C, VP retarded the increase of histamine in milkfish sticks as compared to PEP. In summary, this result suggested the milkfish sticks packed with VP and stored below 4°C could prevent deterioration of product quality and extend shelf-life.

  12. Effect of Focussed Vacuum ARC Plasma Deposition on the Properties of Tetrahedral Amorphous Carbon Films (United States)

    Chua, Daniel H. C.; Teo, K. B. K.; Tsai, T. H.; Robertson, J.; Milne, W. I.

    We have investigated the effect of using a magnetic field to confine and focus the plasma in a Filtered Cathodic Vacuum Arc (FCVA) deposition system used for the preparation of tetrahedrally bonded amorphous carbon (ta-C) thin films. The design of the magnetic field is such that the plasma can be confined into a high-density focussed spot or de-focussed into a lower density wide beam. Increasing the magnetic field directly increases the plasma density and thus increases the deposition rate. The ta-C films grown in the magnetic field were subsequently characterised. EELS and Raman measurement were used to measure the sp3/sp2 ratio and UV-vis spectroscopy for optical bandgap studies. The intrinsic stress and I-V characteristics of the thin films were also studied. The results show that it is possible to deposit the films at rates as high as 2.5 nm/sec without adversely affecting the material properties.

  13. The effect of cinnamon bark (Cinnamomum burmanii) essential oil microcapsules on vacuumed ground beef quality (United States)

    Brilliana, I. N.; Manuhara, G. J.; Utami, R.; Khasanah, L. U.


    Ground beef has a short shelf life because it is susceptible to damage due to microbial contamination and lipid oxidation. So some sort of preservation method such as refrigerated storage, vacuum packaging or natural preservative addition is needed to extend the shelf life of ground beef. A natural preservative that can be used as a food preservative is the cinnamon bark (Cinnamomum burmanii) essential oil microcapsules. The aim of the research was to determine the influence of a cinnamon bark essential oil microcapsules (0%;0.5% and 1% w/w of the ground beef) on the Total Plate Count (TPC), Thiobarbituric Acid (TBA), pH and color of ground beef during refrigerated storage (4±1°C). The result showed that cinnamon bark essential oil microcapsules affected the TPC, TBA, pH and color of ground beef. The addition of the cinnamon bark essential oil microcapsules on ground beef can inhibit microbial growth, inhibit lipid oxidation, inhibit discoloration and lowering pH of fresh ground beef during refrigerated storage compared to the control sample. The higher of the microcapsules were added, the higher the inhibition of microbial growth, lipid oxidation and discoloration of ground beef, indicating better preservation effects.

  14. Effect of high solenoidal magnetic fields on breakdown voltages of high vacuum 805 MHz cavities

    Energy Technology Data Exchange (ETDEWEB)

    Moretti, A.; Bross, A.; Geer, S.; Qian, Z.; /Fermilab; Norem, J.; /Argonne; Li, D.; Zisman, M.; /LBL, Berkeley; Torun, Y.; /IIT, Chicago; Rimmer, R.; /Jefferson Lab; Errede,; /Illinois U., Urbana


    There is an on going international collaboration studying the feasibility and cost of building a muon collider or neutrino factory [1,2]. An important aspect of this study is the full understanding of ionization cooling of muons by many orders of magnitude for the collider case. An important muon ionization cooling experiment, MICE [3], has been proposed to demonstrate and validate the technology that could be used for cooling. Ionization cooling is accomplished by passing a high-emittance muon beam alternately through regions of low Z material, such as liquid hydrogen, and very high accelerating RF Cavities within a multi-Tesla solenoidal field. To determine the effect of very large solenoidal magnetic fields on the generation of dark current, x-rays and on the breakdown voltage gradients of vacuum RF cavities, a test facility has been established at Fermilab in Lab G. This facility consists of a 12 MW 805 MHz RF station and a large warm bore 5 T solenoidal superconducting magnet containing a pill box type cavity with thin removable window apertures. This system allows dark current and breakdown studies of different window configurations and materials. The results of this study will be presented. The study has shown that the peak achievable accelerating gradient is reduced by a factor greater than 2 when solenoidal field of greater than 2 T are applied to the cavity.

  15. The effect of vacuum packaging on histamine changes of milkfish sticks at various storage temperatures. (United States)

    Kung, Hsien-Feng; Lee, Yi-Chen; Lin, Chiang-Wei; Huang, Yu-Ru; Cheng, Chao-An; Lin, Chia-Min; Tsai, Yung-Hsiang


    The effects of polyethylene packaging (PEP) (in air) and vacuum packaging (VP) on the histamine related quality of milkfish sticks stored at different temperatures (-20°C, 4°C, 15°C, and 25°C) were studied. The results showed that the aerobic plate count (APC), pH, total volatile basic nitrogen (TVBN), and histamine contents increased as storage time increased when the PEP and VP samples were stored at 25°C. At below 15°C, the APC, TVBN, pH, and histamine levels in PEP and VP samples were retarded, but the VP samples had considerably lower levels of APC, TVBN, and histamine than PEP samples. Once the frozen fish samples stored at -20°C for 2 months were thawed and stored at 25°C, VP retarded the increase of histamine in milkfish sticks as compared to PEP. In summary, this result suggested the milkfish sticks packed with VP and stored below 4°C could prevent deterioration of product quality and extend shelf-life. Copyright © 2017. Published by Elsevier B.V.

  16. Effects of non-equilibrium angle fluctuation on F1-ATPase kinetics induced by temperature increase. (United States)

    Tamiya, Yuji; Watanabe, Rikiya; Noji, Hiroyuki; Li, Chun-Biu; Komatsuzaki, Tamiki


    F 1 -ATPase (F 1 ) is an efficient rotary protein motor, whose reactivity is modulated by the rotary angle to utilize thermal fluctuation. In order to elucidate how its kinetics are affected by the change in the fluctuation, we have extended the reaction-diffusion formalism [R. Watanabe et al., Biophys. J., 2013, 105, 2385] applicable to a wider range of temperatures based on experimental data analysis of F 1 derived from thermophilic Bacillus under high ATP concentration conditions. Our simulation shows that the rotary angle distribution manifests a stronger non-equilibrium feature as the temperature increases, because ATP hydrolysis and P i release are more accelerated compared with the timescale of rotary angle relaxation. This effect causes the rate coefficient obtained from dwell time fitting to deviate from the Arrhenius relation in P i release, which has been assumed in the previous activation thermodynamic quantities estimation using linear Arrhenius fitting. Larger negative correlation is also found between hydrolysis and P i release waiting time in a catalytic dwell with the increase in temperature. This loss of independence between the two successive reactions at the catalytic dwell sheds doubt on the conventional dwell time fitting to obtain rate coefficients with a double exponential function at temperatures higher than 65 °C, which is close to the physiological temperature of the thermophilic Bacillus.

  17. The Effect on Stellarator Neoclassical Transport of a Fluctuating Electrostatic Spectrum

    Energy Technology Data Exchange (ETDEWEB)

    H.E. Mynick; A.H. Boozer


    We study the effect on neoclassical transport of applying a fluctuating electrostatic spectrum, such as produced either by plasma turbulence, or imposed externally. For tokamaks, it is usually assumed that the neoclassical and ''anomalous'' contributions to the transport roughly superpose, D = D{sub nc} + D{sub an}, an intuition also used in modeling stellarators. An alternate intuition, however, is one where it is the collisional and anomalous scattering frequencies which superpose, {nu}{sub ef} = {nu} + {nu}{sub an}. For nonaxisymmetric systems, in regimes where {partial_derivative}D/{partial_derivative}{nu} < 0, this ''{nu}{sub ef} picture'' implies that turning on the fluctuations can decrease the total radial transport. Using numerical and analytic means, it is found that the total transport has contributions conforming to each of these intuitions, either of which can dominate. In particular, for stellarators, the {nu}{sub ef} picture is often valid, producing transport behavior differing from tokamaks.

  18. Effects of the external magnetic field on the composition-fluctuation potentials in diluted magnetic semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Umehara, Masakatsu [3-11-30 Koyadai, Tsukuba, Ibaraki 305-0074 (Japan)


    We investigated the effects of the external magnetic field on the compositional-fluctuation potentials (APFs) in diluted magnetic semiconductors (DMSs). The APFs in DMSs are divided into two parts: one is the nonmagnetic part usually considered in mixed nonmagnetic semiconductors and the other is the magnetic part caused by the compositional fluctuations of the substituted magnetic ions and the sp-d exchange interaction under the external magnetic field. The APFs in DMSs, thus, depend on the external magnetic field and the temperature as well as the concentration of the magnetic ions; for example in Cd{sub 1-x}Mn{sub x}Te, the APFs increase with the magnetic field up to about 40 kOe for an Mn concentration of x = 0.2 and 0.3, while the APFs decrease drastically with the magnetic field for x less than 0.05 at low temperatures. After a general discussion of the APFs in DMSs, we calculated the exciton magnetic polarons weakly bound to APFs under the external magnetic field. The calculated results were compared with the experiment on the L{sub 2} photoluminescence in Cd{sub 1-x}Mn{sub x}Te, with the purpose of revealing the peculiar properties caused by the magnetic part of the APFs.

  19. Effect of hotspot position fluctuation to writing capability in heated-dot magnetic recording (United States)

    Tipcharoen, Warunee; Warisarn, Chanon; Kaewrawang, Arkom; Kovintavewat, Piya


    This work presents the effect of hotspot position fluctuation to writing capability in heated-dot magnetic recording systems at an areal density (AD) beyond 2 Tbpsi via a micromagnetic modeling. At high ADs, the hotspot and the write field gradient may not be correctly focused on the target island because the bit islands are closely positioned to one another. This may lead to the overwriting/erasing of the previously written islands, which can severely affect the recording performance. Therefore, this work studies the 3-by-3 data patterns that easily cause an error when the hotspot and write head positions are fluctuated by various island pitches. Simulation results indicate that the data pattern that leads to the highest/lowest error occurrence frequency is the one with the first, second and fourth islands having the opposite/same magnetization direction to/as the write field, regardless of the magnetization direction of the third island. This result can, for example, be utilized to design a two-dimensional modulation code to prevent such destructive data patterns, thus helping enhance the overall system performance.

  20. Vacuum Valve

    CERN Multimedia


    This valve was used in the Intersecting Storage Rings (ISR) to protect against the shock waves that would be caused if air were to enter the vacuum tube. Some of the ISR chambers were very fragile, with very thin walls - a design required by physicists on the lookout for new particles.

  1. Relativistic effects and primordial non-Gaussianity in the matter density fluctuation

    Directory of Open Access Journals (Sweden)

    Jaiyul Yoo


    Full Text Available We present the third-order analytic solution of the matter density fluctuation in the proper-time hypersurface of nonrelativistic matter flows by solving the nonlinear general relativistic equations. The proper-time hypersurface provides a coordinate system that a local observer can set up without knowledge beyond its neighborhood, along with physical connections to the local Newtonian descriptions in the relativistic context. The initial condition of our analytic solution is set up by the curvature perturbation in the comoving gauge, clarifying its impact on the nonlinear evolution. We compute the effective non-Gaussian parameters due to the nonlinearity in the relativistic equations. With proper coordinate rescaling, we show that the equivalence principle is respected and the relativistic effect vanishes in the large-scale limit.

  2. Relativistic effects and primordial non-Gaussianity in the matter density fluctuation

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Jaiyul, E-mail: [Center for Theoretical Astrophysics and Cosmology, Institute for Computational Science, University of Zürich, CH-8057 Zürich (Switzerland); Physik-Institut, University of Zürich, CH-8057 Zürich (Switzerland); Gong, Jinn-Ouk, E-mail: [Asia Pacific Center for Theoretical Physics, Pohang, 790-784 (Korea, Republic of); Department of Physics, Postech, Pohang 790-784 (Korea, Republic of)


    We present the third-order analytic solution of the matter density fluctuation in the proper-time hypersurface of nonrelativistic matter flows by solving the nonlinear general relativistic equations. The proper-time hypersurface provides a coordinate system that a local observer can set up without knowledge beyond its neighborhood, along with physical connections to the local Newtonian descriptions in the relativistic context. The initial condition of our analytic solution is set up by the curvature perturbation in the comoving gauge, clarifying its impact on the nonlinear evolution. We compute the effective non-Gaussian parameters due to the nonlinearity in the relativistic equations. With proper coordinate rescaling, we show that the equivalence principle is respected and the relativistic effect vanishes in the large-scale limit.

  3. Faraday-effect polarimeter diagnostic for internal magnetic field fluctuation measurements in DIII-D. (United States)

    Chen, J; Ding, W X; Brower, D L; Finkenthal, D; Muscatello, C; Taussig, D; Boivin, R


    Motivated by the need to measure fast equilibrium temporal dynamics, non-axisymmetric structures, and core magnetic fluctuations (coherent and broadband), a three-chord Faraday-effect polarimeter-interferometer system with fast time response and high phase resolution has recently been installed on the DIII-D tokamak. A novel detection scheme utilizing two probe beams and two detectors for each chord results in reduced phase noise and increased time response [δb ∼ 1G with up to 3 MHz bandwidth]. First measurement results were obtained during the recent DIII-D experimental campaign. Simultaneous Faraday and density measurements have been successfully demonstrated and high-frequency, up to 100 kHz, Faraday-effect perturbations have been observed. Preliminary comparisons with EFIT are used to validate diagnostic performance. Principle of the diagnostic and first experimental results is presented.

  4. Effects of inorganics on the degradation of micropollutants with vacuum UV (VUV) advanced oxidation. (United States)

    Duca, Clara; Imoberdorf, Gustavo; Mohseni, Madjid


    This research focused on the effects of inorganic water constituents on the efficiency of vacuum UV (VUV) for the degradation of micropollutants in surface water supplies. Atrazine was used as a model miropollutant, and bicarbonate, sulphate, and nitrate were used as the most common inorganic constituents in the water matrix. First, the absorbance of radiation at 254 and 185 nm was measured in the presence of different ions. At 254 nm, only nitrate showed a measurable absorption coefficient of [Formula: see text] = 3.51 M[Formula: see text] cm[Formula: see text], and all other ions showed a molar absorption coefficient below the detection limit. However, at 185 nm, all the ions showed high absorption coefficients, with nitrate giving the highest absorption coefficient of [Formula: see text] = 5568 M[Formula: see text] cm[Formula: see text]. Second, the hydroxyl radical (HO[Formula: see text]) scavenging effects of the same inorganic ions were evaluated; nitrate and bicarbonate showed a negative effect during the UV/H2O2 and VUV advanced oxidation processes. Sulfate was photolyzed with 185 nm UV to form HO[Formula: see text], and for this reason, it assisted the degradation of the target micropollutant, as demonstrated by increases in the degradation rate constant. An additional component of this work involved developing a method for measuring the quantum yield of atrazine at 185 nm. This made it possible to distinguish the contribution of OH radical attach from that of direct photolysis towards the degradation of atrazine.


    Directory of Open Access Journals (Sweden)

    Que Yun


    Full Text Available In order to reveal the fluctuation effect of equilibrium moisture content of low subgrade in hot and humid climatic regions, the effect of temperature on the fluctuation of the equilibrium moisture content of subgrade was analysed. Taking the typical climate and the subgrade soil in Fujian province as an example, three technological methods - theoretical analysis, numerical simulation and indoor simulation experiment - were adopted in the investigation of the fluctuation effect of equilibrium moisture content of subgrade. The results show that, computing results from the formula of the equilibrium moisture content of subgrade, the numerical simulation results are closer to each other in consideration of the temperature effect. The test results can not reflect the relationship between the equilibrium moisture content and the height of embankment. The maximum fluctuation range of the equilibrium moisture content of the cement concrete pavement is less than 2 percent in Fujian area, and this phenomenon presents the effect of the moist-hot climate on the equilibrium moisture content. Equilibrium moisture content presents a declining trend with the increment of the temperature and the compactness. So, if matric potential considering temperature indirectly reflects the influence of thermal potential, then the equilibrium moisture content of low subgrade under high groundwater level can be estimated approximately. The fluctuation range of equilibrium moisture content in different layers of subgrade can be reduced effectively with the increment of the roadbed compaction degree.

  6. [Effects of vacuum drainage combined with heparin irrigation for treatment of scald burns with seawater immersion in rabbits]. (United States)

    Zhang, Wen-Hao; Wu, Qi; Ma, Jun; Wang, Jia-Han


    To investigate the effect of closed vacuum drainage combined with heparin irrigation in the treatment of scald burns with seawater immersion in rabbits. Twenty New Zealand rabbits were subjected to deep partial-thickness scald burns in 4 regions on the bilateral skin of the spine. The wounds were managed with common dressing (group A), common dressing after seawater immersion (group B), closed vacuum drainage after seawater immersion (group C), or closed vacuum drainage combined with heparin irrigation after seawater immersion (group D). Wound effusion and tissue necrosis were observed at 1, 3, 5 and 7 days after the burns. Tissue samples were collected from the wounds for HE staining and immunohistochemistry for VEGF and CD31, and the changes of capillary endothelial cells in the wound were observed using electron microscopy. The water content in the wound tissues was determined, and the wound healing rate was calculated after the injury. Sea water immersion of the wound results in earlier onset of edema and more extensive tissue necrosis in the scalded rabbits. The mean necrotic area in groups C and D was smaller than that in group B early after the burns, and vacuum drainage promoted necrotic tissue elimination and accelerated wound healing. Early after the burns, water content in the tissues increased with time in all the groups and reached the highest level at 3 days, and was significantly lower in groups C and D than in group B. Pathologically, vascular endothelial cell damage at the wound site was worsened after seawater immersion. In group D, the basement membrane damage was milder and the endothelial cell membrane remained intact at the wound site, where new blood vessels occurred at 3 days after the burns, a time earlier than that in the other 3 groups with also the highest vascular density. Closed vacuum drainage combined with heparin irrigation can relieve edema at the scald wound with seawater immersion, improve microcirculation, accelerate the removal

  7. Effects of Barometric Fluctuations on Well Water-Level Measurements and Aquifer Test Data

    Energy Technology Data Exchange (ETDEWEB)

    FA Spane, Jr.


    The Pacific Northwest National Laboratory, as part of the Hanford Groundwater Monitoring Project, examines the potential for offsite migration of contamination within underlying aquifer systems. Well water-level elevation measurements from selected wells within these aquifer systems commonly form the basis for delineating groundwater-flow patterns (i.e., flow direction and hydraulic gradient). In addition, the analysis of water-level responses obtained in wells during hydrologic tests provides estimates of hydraulic properties that are important for evaluating groundwater-flow velocity and transport characteristics. Barometric pressure fluctuations, however, can have a discernible impact on well water-level measurements. These barometric effects may lead to erroneous indications of hydraulic head within the aquifer. Total hydraulic head (i.e., sum of the water-table elevation and the atmospheric pressure at the water-table surface) within the aquifer, not well water-level elevation, is the hydrologic parameter for determining groundwater-flow direction and hydraulic gradient conditions. Temporal variations in barometric pressure may also adversely affect well water-level responses obtained during hydrologic tests. If significant, adjustments or removal of these barometric effects from the test-response record may be required for quantitative hydraulic property determination. This report examines the effects of barometric fluctuations on well water-level measurements and evaluates adjustment and removal methods for determining areal aquifer head conditions and aquifer test analysis. Two examples of Hanford Site unconfined aquifer tests are examined that demonstrate barometric response analysis and illustrate the predictive/removal capabilities of various methods for well water-level and aquifer total head values. Good predictive/removal characteristics were demonstrated with best corrective results provided by multiple-regression deconvolution methods.

  8. Insulation vacuum and beam vacuum overpressure release

    CERN Document Server

    Parma, V


    There is evidence that the incident of 19th September caused a high pressure build-up inside the cryostat insulation vacuum which the existing overpressure devices could not contain. As a result, high longitudinal forces acting on the insulation vacuum barriers developed and broke the floor and the floor fixations of the SSS with vacuum barriers. The consequent large longitudinal displacements of the SSS damaged chains of adjacent dipole cryo-magnets. Estimates of the helium mass flow and the pressure build- up experienced in the incident are presented together with the pressure build-up for an even more hazardous event, the Maximum Credible Incident (MCI). The strategy of limiting the maximum pressure by the installation of addition pressure relieve devices is presented and discussed. Both beam vacuum lines were ruptured during the incident in sector 3-4 giving rise to both mechanical damage and pollution of the system. The sequence, causes and effects of this damage will be briefly reviewed. We will then an...

  9. Efficacy and haemodynamic effects of vacuum-assisted closure for post-sternotomy mediastinitis in children. (United States)

    Takahara, Shingo; Sai, Sadahiro; Kagatani, Tomoaki; Konishi, Akinobu


    Post-sternotomy mediastinitis is a significant morbidity with controversial management. Vacuum-assisted closure (VAC) has been used to treat mediastinitis, with many reports documenting its efficacy and feasibility, particularly in adults. However, its use is not prevalent in the paediatric population because of concerns that it may deteriorate haemodynamics. This study aimed to evaluate outcomes and effects of VAC on the haemodynamics of paediatric patients with post-sternotomy mediastinitis. Six patients were treated with VAC between April 2005 and March 2013. We retrospectively investigated their profiles, clinical outcomes and haemodynamic changes, including mean blood pressure (MBP), mean heart rate (MHR), urinary output, amount of diuretics and vasoactive-inotropic score (VIS), before and after VAC initiation. The median age and body weight of patients were 6.4 months and 4.5 kg, respectively. Three patients (50%) had single ventricular physiology. The median VAC duration was 12 days. One patient died of pulmonary venous obstruction after mediastinitis was cured. The average MBPs in every 8-h period were examined, and there were no significant changes (P = 0.773); the average MHRs were examined in the same manner and they decreased significantly after initiation of VAC (P = 0.032). Only 2 patients required vasoactive agents. The VIS did not change in 1 patient and decreased in the other. The mean amount of diuretics administered and urinary output per body weight did not change significantly (P = 0.395 and 0.273, respectively). In conclusion, the haemodynamics of children were not significantly affected by the negative pressure of VAC, indicating that this therapy may be safe and effective for post-sternotomy mediastinitis, even in small children with complex cardiac anomalies. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  10. Beneficial synergetic effect on gas production during co-pyrolysis of sewage sludge and biomass in a vacuum reactor. (United States)

    Zhang, Weijiang; Yuan, Chengyong; Xu, Jiao; Yang, Xiao


    A vacuum fixed bed reactor was used to pyrolyze sewage sludge, biomass (rice husk) and their blend under high temperature (900°C). Pyrolytic products were kept in the vacuum reactor during the whole pyrolysis process, guaranteeing a long contact time (more than 2h) for their interactions. Remarkable synergetic effect on gas production was observed. Gas yield of blend fuel was evidently higher than that of both parent fuels. The syngas (CO and H2) content and gas lower heating value (LHV) were obviously improved as well. It was highly possible that sewage sludge provided more CO2 and H2O during co-pyrolysis, promoting intense CO2-char and H2O-char gasification, which benefited the increase of gas yield and lower heating value. The beneficial synergetic effect, as a result, made this method a feasible one for gas production. Copyright © 2015. Published by Elsevier Ltd.

  11. The effect of thermal fluctuations on Holstein polaron dynamics in electric field (United States)

    Voulgarakis, Nikolaos K.


    In this work, we have studied the effects of thermal fluctuations on the stability of polaron motion under the influence of an external electric field. Zero temperature calculations have been reported previously showing the existence of critical electric field, Ecr, where the system transitions from a stable polaron motion to a Bloch-like oscillation. In this study, we further report that for intermediate polaron sizes the lifetime of such Bloch-like oscillations decay with time due to excessive phonon emission. Our numerical simulations show that the value of Ecr is finite for small temperatures. However, Ecr rapidly decreases with increasing T and becomes practically zero for T > Tcr. In this small but finite temperature window, we report how temperature affects (a) the electric current density, and (b) the Bloch-like frequencies.

  12. Real-space fluctuations of effective exchange integrals in high-Tc cuprates (United States)

    Petit, S.; Lepetit, M.-B.


    We present ab initio calculations of effective magnetic exchange, J, as well as Hubbard parameters (t, U and δɛ) as a function of the local distribution of doping atoms for the high-Tc superconducting (CaxLa1-x)(Ba1.75-xLa0.25+x)Cu3Oy family. We found that both the exchange and the energies of the magnetic orbitals are strongly dependent on the local dopant distribution, both through the induced modification of the apical oxygen location and of the induced local electrostatic potential. The J real-space map, for a random distribution of dopants, positively compares with observed STS gap inhomogeneity maps. Similarly, the orbital energy fluctuations induce weak charge inhomogeneities on copper sites, that can be positively compared with the observed LDOS inhomogeneities. These results clearly support an extrinsic origin of both the gap inhomogeneities and LDOS.

  13. Directed percolation process in the presence of velocity fluctuations: Effect of compressibility and finite correlation time (United States)

    Antonov, N. V.; Hnatič, M.; Kapustin, A. S.; Lučivjanský, T.; Mižišin, L.


    The direct bond percolation process (Gribov process) is studied in the presence of random velocity fluctuations generated by the Gaussian self-similar ensemble with finite correlation time. We employ the renormalization group in order to analyze a combined effect of the compressibility and finite correlation time on the long-time behavior of the phase transition between an active and an absorbing state. The renormalization procedure is performed to the one-loop order. Stable fixed points of the renormalization group and their regions of stability are calculated in the one-loop approximation within the three-parameter (ɛ ,y ,η ) expansion. Different regimes corresponding to the rapid-change limit and frozen velocity field are discussed, and their fixed points' structure is determined in numerical fashion.

  14. Effects of multilayered graphene on the performance of near-field thermophotovoltaic system at longer vacuum gap distances (United States)

    Lim, Mikyung; Lee, Seung S.; Lee, Bong Jae


    The present work aims to enhance the performance of near-field thermophotovoltaic (TPV) system operated at low temperature by introducing multilayered graphene on top of the TPV cell. The multilayered graphene shifts the surface plasmon polariton to the condition where heat flux occurs efficiently at vacuum gap longer than 50 nm. It is found that three-layer graphene can increase the power output by 5.8 times at 50-nm vacuum gap, whereas a monolayer of graphene has a negligible effect at such distance. The fundamental mechanism for the enhancement by the multilayered graphene is explored by analyzing the heat transfer and corresponding photocurrent generation through three modes: propagating, frustrated, and surface modes. Through the detailed analysis, the optimal number of the graphene layers depending on the vacuum gap distance can be predicted. Considering a penetration depth inside the TPV cell, the effect of the width of p-region of the cell on the power output is discussed. It is shown that the change of the width of p-region can either improve or suppress the effect of graphene. The results obtained in this study can facilitate future development of practical TPV system with high performance.

  15. Study of the combined effect of spices and marination on beef meat vacuum packaged

    Directory of Open Access Journals (Sweden)



    Full Text Available Fresh beef slices were marinated by immersion in marinades based on dry red wine, lime-tree honey, salt, spices and seasoning plants as thyme (Thymus vulgaris, marjoram (Majorana hortensis, garlic (Allium sativum and horseradish (Armoracia rusticana. Control samples were represented by raw meat without marination treatment but stored in the same conditions as marinated samples. After marination, meat pieces were packed under vacuum and stored at refrigeration temperature of 4°C for 12 days. The influence of the combined effect of spices and marination on beef stability was evaluated by monitoring pH evolution, degree of lipid oxidation and by microbiological analysis. For control samples, a mean increase of 0.47 log CFU/g of total mesophilic aerobic bacteria was observed during the 48 h of storage, but for the samples marinated with the addition of spices was observed a decrease of 0.57 log CFU/g. The growth of LAB in control samples was generally limited and did not exceed 5 log CFU/g. During storage at 4°C, marination with the addition in the base marinade (wine, honey, garlic, pepper and salt of thyme, marjoram and horseradish separately inhibited the growth of LAB while marination with the addition in the base marinade of thyme, marjoram and horseradish together resulted in significantly lower levels of LAB. All marination treatments resulted in significantly lower TBA and POV values at the end of storage compared to the control. Marination with dry red wine, lime-tree honey, thyme marjoram, garlic, and horseradish can evidently control total mesophilic aerobic bacteria, lactic acid bacteria and oxidation of beef meat.

  16. The clinical efficacy and cost effectiveness of the vacuum-assisted closure technique in the management of acute and chronic wounds: a randomized controlled trial. (United States)

    Braakenburg, Assa; Obdeijn, Miryam C; Feitz, Reinier; van Rooij, Iris A L M; van Griethuysen, Arjanne J; Klinkenbijl, Jean H G


    Vacuum-assisted closure therapy is a relatively new concept described in the literature that increases wound-healing capacity. The authors aimed to investigate the effect of vacuum-assisted closure therapy on wound healing, granulation tissue formation, bacterial clearance, pain, time involvement of the staff, and total costs in all types of wounds in comparison with modern wound dressings. Sixty-five patients with a chronic or acute wound were randomized to initial treatment with vacuum-assisted closure or modern dressings. The authors' primary endpoint was a granulated wound or a wound ready for skin grafting or healing by secondary intention. The time to the primary endpoint with vacuum-assisted closure therapy was not significantly shorter, except for patients with cardiovascular disease and/or diabetics. Vacuum-assisted closure therapy did not result in significantly faster granulation or wound surface reduction or better bacterial clearance, but patient comfort was an important advantage. Time involvement and costs of nursing staff were significantly lower for the vacuum-assisted closure therapy, but overall costs were similar for both groups. With vacuum-assisted closure therapy, wound healing is at least as fast as with modern wound dressings. Especially cardiovascular and diabetic patients benefit from this therapy. The total costs of vacuum-assisted closure are comparable to those of modern wound dressings, but the advantage is its comfort for patients and nursing staff.

  17. Effects of vole fluctuations on the population dynamics of the barn owl Tyto alba

    NARCIS (Netherlands)

    Klok, T.C.; Roos, A.M.


    Many predator species feed on prey that fluctuates in abundance from year to year. Birds of prey can face large fluctuations in food abundance i.e. small mammals, especially voles. These annual changes in prey abundance strongly affect the reproductive success and mortality of the individual

  18. Vacuum space charge effects in sub-picosecond soft X-ray photoemission on a molecular adsorbate layer

    Directory of Open Access Journals (Sweden)

    M. Dell'Angela


    Full Text Available Vacuum space charge induced kinetic energy shifts of O 1s and Ru 3d core levels in femtosecond soft X-ray photoemission spectra (PES have been studied at a free electron laser (FEL for an oxygen layer on Ru(0001. We fully reproduced the measurements by simulating the in-vacuum expansion of the photoelectrons and demonstrate the space charge contribution of the high-order harmonics in the FEL beam. Employing the same analysis for 400 nm pump-X-ray probe PES, we can disentangle the delay dependent Ru 3d energy shifts into effects induced by space charge and by lattice heating from the femtosecond pump pulse.

  19. Vacuum space charge effects in sub-picosecond soft X-ray photoemission on a molecular adsorbate layer. (United States)

    Dell'Angela, M; Anniyev, T; Beye, M; Coffee, R; Föhlisch, A; Gladh, J; Kaya, S; Katayama, T; Krupin, O; Nilsson, A; Nordlund, D; Schlotter, W F; Sellberg, J A; Sorgenfrei, F; Turner, J J; Öström, H; Ogasawara, H; Wolf, M; Wurth, W


    Vacuum space charge induced kinetic energy shifts of O 1s and Ru 3d core levels in femtosecond soft X-ray photoemission spectra (PES) have been studied at a free electron laser (FEL) for an oxygen layer on Ru(0001). We fully reproduced the measurements by simulating the in-vacuum expansion of the photoelectrons and demonstrate the space charge contribution of the high-order harmonics in the FEL beam. Employing the same analysis for 400 nm pump-X-ray probe PES, we can disentangle the delay dependent Ru 3d energy shifts into effects induced by space charge and by lattice heating from the femtosecond pump pulse.

  20. Effect of heat treatments in vacuum on CdS thin films prepared by the spray deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Escosura, L.; Garcia-Camarero, E.; Arjona, F.; Rueda, F.


    The effects of short heat treatments in vacuum (10 min at 200-400/sup 0/C) on the electrical, structural and optical properties of hexagonal polycrystalline CdS thin films prepared by the spray deposition technique were studied. It was found that the electrical and structural properties change remarkably under these treatments. However, the optical properties do not vary significantly. The resistivity, in particular, decreased from about 500 ..cap omega.. cm to less then 1 ..cap omega.. for a 300/sup 0/C annealing while the electron mobility increased by two orders of magnitude, a result similar to that reported by Martinuzzi and coworkers. A hexagonal phase was obtained regardless of deposition temperature. The preferential orientation changed when samples were subjected to vacuum annealing at 300/sup 0/C or more, indicating that a recrystallization had taken place in the films.

  1. An Effective Vacuum Assisted Extraction Method for the Optimization of Labdane Diterpenoids from Andrographis paniculata by Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Ya-Qi Wang


    Full Text Available An effective vacuum assisted extraction (VAE technique was proposed for the first time and applied to extract bioactive components from Andrographis paniculata. The process was carefully optimized by response surface methodology (RSM. Under the optimized experimental conditions, the best results were obtained using a boiling temperature of 65 °C, 50% ethanol concentration, 16 min of extraction time, one extraction cycles and a 12:1 liquid-solid ratio. Compared with conventional ultrasonic assisted extraction and heat reflux extraction, the VAE technique gave shorter extraction times and remarkable higher extraction efficiency, which indicated that a certain degree of vacuum gave the solvent a better penetration of the solvent into the pores and between the matrix particles, and enhanced the process of mass transfer. The present results demonstrated that VAE is an efficient, simple and fast method for extracting bioactive components from A. paniculata, which shows great potential for becoming an alternative technique for industrial scale-up applications.

  2. Effect of electrical current on the tribological behavior of the Cu-WS2-G composites in air and vacuum (United States)

    Qian, Gang; Feng, Yi; Li, Bin; Huang, Shiyin; Liu, Hongjuan; Ding, Kewang


    As the traditional graphite-based composites cannot meet the requirement of rapid developing modern industry, novel sliding electrical contact materials with high self-lubricating performance in multiple environments are eagerly required. Herein a copper-based composite with WS2 and graphite as solid lubricant are fabricated by powder metallurgy hot-pressed method. The friction and wear behaviors of the composites with and without current are investigated under the condition with sliding velocity of 10 m/s and normal load of 2.5 N/cm2 in both air and vacuum. Morphologies of the worn surfaces are observed by optical microscope and compositions of the lubricating films are analyzed by XPS. Surface profile curves and roughness of the worn surfaces are obtained by 2205 surface profiler. The results of wear tests show that the friction coefficient and wear volume loss of the composites with current are greater than that without current in both air and vacuum due to the adverse effects of electrical current which damaged the lubricating film partially and roughed the worn surfaces. XPS results demonstrate that the lubricating film formed in air is composed of oxides of Cu, WS2, elemental S and graphite, while the lubricating film formed in vacuum is composed of Cu, WS2 and graphite. Because of the synergetic lubricating action of oxides of Cu, WS2 and graphite, the composites show low friction coefficient and wear volume loss in air condition. Owing to the fact that graphite loses its lubricity which makes WS2 become the only lubricant, severe adhesive and abrasive wear occur and result in a high value of wear rate in vacuum condition. The formation of the lubricating film on the contact interface between the brush and ring is one of the factors which can greatly affect the wear performance of the brushes. The low contact voltage drop of the composites in vacuum condition is attributed to the high content of Cu in the surface film. This study fabricated a kind of new

  3. Proton flux effects and prediction on the free radicals behavior of polyimide in vacuum using EPR measurements in ambient

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Chengyue [Physics Department, Harbin Institute of Technology, Harbin 150001 (China); National Key Lab of Materials Behaviors and Evaluation Technology in Space Environments, Harbin Institute of Technology, Harbin 150001 (China); Wu, Yiyong, E-mail: [National Key Lab of Materials Behaviors and Evaluation Technology in Space Environments, Harbin Institute of Technology, Harbin 150001 (China); Xiao, Jingdong [National Key Lab of Materials Behaviors and Evaluation Technology in Space Environments, Harbin Institute of Technology, Harbin 150001 (China); Yu, Sui [Physics Department, Harbin Institute of Technology, Harbin 150001 (China); Yi, Zhong; Shen, Zicai [Chinese Academy of Sciences, Beijing 100029 (China); Wang, Li [Qian Xuesen Laboratory of Space Technology, Beijing 100029 (China); Wang, Yi [Lanzhou Institute of Physics, CAST, Lanzhou 730000 (China)


    Irradiation flux is an important parameter to the material irradiation damage investigation, for space material irradiation damage evaluation and the accelerated ground-based test, the irradiation flux effects cannot be ignored. In this paper, the polyimide was set as the research object, the irradiation flux effect and mechanism are investigated by the means of electron paramagnetic resonance test, and based on the free radical dynamic analysis, the dynamics mode of free radical population in vacumm can be established as a function of irradiation time (or proton irradiation flux). The results show that the free radical anneal process in vacuum follows the exponential mode, and the characteristic time constant τ{sub radical-vacuum} is about 1.9 h. Furthermore, a simplified method is proposed with the investigation of the free radical behavior of the irradiated surface modification polyimide (TiO{sub 2}/PI), and the characteristic time constant τ{sub bulk} is 1.9 h, which is almost the same to the value of τ{sub radical-vacuum}.

  4. Engineering matter interactions using squeezed vacuum (United States)

    Zeytinoglu, Sina; Imamoglu, Atac; Huber, Sebastian

    Virtually all interactions that are relevant for atomic and condensed matter physics are mediated by the quantum fluctuations of the electromagnetic field vacuum. Consequently, controlling the latter can be used to engineer the strength and the range of inter-particle interactions. Recent experiments have used this premise to demonstrate novel quantum phases or entangling gates by embedding electric dipoles in photonic cavities or waveguides which modify the electromagnetic fluctuations. In this talk, we demonstrate theoretically that the enhanced fluctuations in the anti-squeezed quadrature of a squeezed vacuum state allows for engineering interactions between electric dipoles without the need for a photonic cavity or waveguide. Thus, the strength and range of the resulting dipole-dipole coupling can be engineered by dynamically changing the spatial profile of the squeezed vacuum in a travelling-wave geometry. ETH Zurich.

  5. Effects of density fluctuations on nonlinear evolution of low-frequency Alfven waves in solar wind plasmas (United States)

    Nariyuki, Y.; Seough, J.


    It is well known that low-frequency Alfven waves are unstable to parametric instabilities, in which these waves are nonlinearly coupled with density fluctuations [e.g, Nariyuki+Hada, JGR, 2007 and references therein]. In solar wind plasmas, low-frequency fluctuations with non-zero cross-helicity are frequently observed [e.g., Bruno+Carbone, Living Rev. Solar Phys. (2013) and references therein]. When the absolute values of normalized cross helicities are close to the unity, the fluctuations may be composed of uni-directionally (anti-sunward) propagating Alfven waves. The derivative nonlinear Schrodinger equation (DNLS) has been known as the mode of modulational instabilities of unidirectional Alfven waves [Mio et al, JPSJ, 1976; Mjolhus, JPP, 1976]. In the DNLS, the density fluctuations are assumed to be the quasi-static state, which is determined according to the ponderomotive force of envelope-modulated Alfven waves. The DNLS was extended to include the obliquely propagating, compressional component of magnetic field by Mjolhus and Wyller (JPP, 1988). The kinetically modified DNLS (KDNLS) has also been discussed by many authors [Rogister, POF, 1971; Mjolhus and Wyller, Phys. Scr, 1986; JPP, 1988; Spangler, POF B, 1989; 1990; Medvedev+Diamond, POP, 1996; Nariyuki et al, POP, 2013]. On the other hand, ion acoustic modes [Hada, 1993], large scale inhomogeneity of plasmas [Buti et al, APJ, 1999; Nariyuki, POP, 2015] and random density fluctuations [Ruderman, POP, 2002] can also affect nonlinear evolution of Alfven waves. At the present time, combined effects of these effects are not fully understood. In this presentation, we discuss two models: one of them is the model including both ion kinetic effects and ion acoustic mode and another is the model including finite thermal effects and random density fluctuations. In the former case, ion kinetic effects on both longitudinal [Nariyuki+Hada, JPSJ, 2007] and transverse modulational instabilities are discussed, while the

  6. Low-order statistics of effective permittivity and electric field fluctuations in two-phase heterostructures (United States)

    Shamoon, D.; Lasquellec, S.; Brosseau, C.


    Understanding the collective, low-frequency dielectric properties of heterostructures is a major goal in condensed matter. In 1935, Bruggeman [Ann. Phys. Lpz. 24, 636 (1935)] conceived the concept of an effective medium approximation (EMA) involving a decoupling between the low-order statistics of the electric field fluctuations and the characteristic length scales. We report on and characterize, via finite element studies, the low-order statistics effective permittivity of two-phase 2D and 3D random and deterministic heterostructures as geometry, phase permittivity contrast, and inclusion content are varied. Since EMA analytical expressions become cumbersome even for simple shapes and arrangements, numerical approaches are more suitable for studying heterostructures with complex shapes and topologies. Our numerical study verifies the EMA analytic predictions when the scales are well-separated. Our numerical study compares two approaches for calculating effective permittivity by explicit calculations of local average fields and energy as geometry, phase permittivity contrast, and inclusion content are varied. We study the conditions under which these approaches give a reliable estimate of permittivity by comparing with 2D/3D EMA analytical models and duality relation. By considering 2D checkerboards which consist of a multitude of contiguous N × N square cells, the influence of the internal length scale (i.e., N) on permittivity is discussed.

  7. Temperature fluctuation caused by coaxial-jet flow: Experiments on the effect of the velocity ratio R ⩾ 1

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Qiong, E-mail: [Beijing Key Laboratory of Passive Safety Technology for Nuclear Energy, North China Electric Power University, Beijing 102206 (China); Li, Hongyuan, E-mail: [School of Control and Computer Engineering, North China Electric Power University, Beijing 102206 (China); Lu, Daogang, E-mail: [Beijing Key Laboratory of Passive Safety Technology for Nuclear Energy, North China Electric Power University, Beijing 102206 (China); Chang, Mu, E-mail: [Beijing Key Laboratory of Passive Safety Technology for Nuclear Energy, North China Electric Power University, Beijing 102206 (China)


    Highlights: • The effect on temperature fluctuation from velocity ratio was studied by experiment. • The distribution of time-averaged temperatures is the axial-symmetry in R ⩾ 1. • The region of intense temperature fluctuation in R = 1 is different from that of R > 1. • The intensity of temperature fluctuation under R > 1 is weaker than that of R = 1. - Abstract: The temperature fluctuation appears in the core outlet region due to the different of the temperature and velocity of the coolant, which can cause thermal stresses and the high-cycle thermal fatigue on solid boundaries. So, it is necessary to analyze the characteristics of the temperature fluctuation. In the present study, a comparative experiment was performed to analyze the effect on the temperature fluctuation caused by the coaxial-jet flow from the inlet cold and hot fluid velocity ratios (R ⩾ 1). In the condition of R ⩾ 1, the distribution of the time-averaged temperature is the axial-symmetry. In the cold fluid field, the temperature field is divided into four parts, including the first steady region, linear region, nonlinear region and the second steady region along the axial direction, while that is lack of the first steady state region in the hot fluid field. In the condition of R = 1, due to the velocity of the cold fluid is equivalent to that of the hot fluid, the cold fluid flow can be severely disturbed by the hot flow. The intense temperature fluctuation mainly distributed in the annular region at bottom region and the circular region in the upper region. While, in the condition of R > 1, the inertia of the cold fluid is larger than that of the hot fluid. The hot fluid will attach itself to the periphery of the cold fluid. The intense temperature fluctuation distributed in the annular region between the cold and hot fluid and the periphery of the hot fluid. However, the intensity of temperature fluctuation under R > 1 is weaker than that of R = 1.

  8. Effect of vacuum oxy-nitrocarburizing on the microstructure of tool steels: an experimental and modeling study

    Directory of Open Access Journals (Sweden)

    Nikolova Maria


    Full Text Available The thermochemical treatments of tool steels improve the performance of the components with respect to surface hardness, wear and tribological performance as well as corrosion resistance. Compared to the conventional gas ferritic nitrocarburizing process, the original vacuum oxy-nitrocarburizing is a time-, cost-effective and environmentally-friendly gas process. Because of the oxidizing nature of the gas atmosphere, there is no need to perform subsequent post-oxidation.In this study, a vacuum oxynitrocarburizing process was carried out onto four tool steels (AISI H10, H11, H21 and D2 at 570 °C, after hardening and single tempering. The structural analysis of the compound and diffusion layers was performed by optical and electron microscopy, X-ray diffraction and glow discharge optical emission spectrometry (GDOES methods. A largely monophase ε- layer is formed with a carbon accumulation at the substrate adjacent area. The overlaying oxides adjacent to the ε-carbonitride phase contained Fe3O4 (magnetite as a main constituent. A thermodynamic modelling approach was also performed to understand and optimize the process. The “Equilib module” of FactSage software which uses Gibbs energy minimization method, was used to estimate the possible products during vacuum oxynitrocarburising process.

  9. The effect of grinding at various vacuum levels on the color, phenolics, and antioxidant properties of apple. (United States)

    Kim, Ah-Na; Kim, Hyun-Jin; Kerr, William L; Choi, Sung-Gil


    The purpose of this study was to evaluate the effect of grinding at different vacuum levels (2.67, 6.67, 13.33, 19.99, and 101.33kPa) on key quality factors of apple. In the control apple, ground at atmospheric pressure of 101.33kPa, the antioxidant activities rapidly decreased within the first 30min, then plateaued thereafter, while enzymatic browning increased. When apples were ground and held under vacuum, changes in color and antioxidant activity were much less, and the least change was measured in samples prepared at the lowest pressure. Model fitting of the data showed that antioxidant activity decreased as a function of the logarithm of the absolute pressure. The results from analysis for key phenolic compounds including chlorogenic acid, procyanidin B2, and epicatechin indicated that these compounds were least changed at vacuum grinding at 2.67kPa, compared to atmospheric grinding. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Effect of Air and Vacuum Storage on the Tensile Properties of X-Ray Exposed Aluminized-FEP (United States)

    deGroh, Kim K.; Gummow, Jonathan D.


    Metallized Teflon(Registered Trademark) FEP (fluorinated ethylene propylene), a common spacecraft thermal control material, from the exterior layer of the Hubble Space Telescope (HST) has become embrittled and suffers from extensive cracking. Teflon samples retrieved during Hubble servicing missions and from the Long Duration Exposure Facility (LDEF) indicate that there may be continued degradation in tensile properties over time. An investigation has been conducted to evaluate the effect of air and vacuum storage on the mechanical properties of x-ray exposed FEP. Aluminized-FEP (Al-FEP) tensile samples were irradiated with 15.3 kV Cu x-rays and stored in air or under vacuum for various time periods. Tensile data indicate that samples stored in air display larger decreases in tensile properties than for samples stored under vacuum. Air-stored samples developed a hazy appearance, which corresponded to a roughening of the aluminized surface. Optical property changes were also characterized. These findings indicate that air exposure plays a role in the degradation of irradiated FEP, therefore proper sample handling and storage is necessary with materials retrieved from space.

  11. Turbulent effects of strong irradiance fluctuations on the orbital angular momentum mode of fractional Bessel Gauss beams. (United States)

    Gao, Jie; Zhang, Yixin; Dan, Weiyi; Hu, Zhengda


    The turbulent effects of strong irradiance fluctuations on the probability densities and the normalized powers of the orbital angular momentum (OAM) modes are modeled for fractional Bessel Gauss beams in paraxial turbulence channel. We find that the probability density of signal OAM modes is a function of position deviation from the beam center, and the farther away from the beam center the detection position is, the smaller the probability density is. For fractional OAM quantum numbers, the average probability densities of signal/crosstalk modes oscillate along the beam radius except the half-integer. When the beam waist of source decreases or the irradiance fluctuation increases, the average probability density of the signal OAM mode drops. The peak of the average probability density of crosstalk modes shifts to outward of the beam center as beam waist gets larger. In the nearby region of beam center, the larger the quantum number deviation of OAM, the smaller the beam waist and the turbulence fluctuations are, the lower average probability densities of crosstalk OAM modes are. Especially, the increase of turbulence fluctuations can make the crosstalk stronger and more concentrated. Lower irradiance fluctuation can give rise to higher the normalized powers of the signal OAM modes, which is opposite to the crosstalk normalized powers.

  12. Ion effects in the SLC electron damping ring under exceptionally poor vacuum conditions

    Energy Technology Data Exchange (ETDEWEB)

    Zimmermann, F.; Krejcik, P.; Minty, M.; Pritzkau, D.; Raubenheimer, T.; Ross, M.; Woodley, M.


    In 1996, due to a catastrophic kicker chamber failure in the SLC electron damping ring, the ring vacuum system was contaminated for several months. During this time, the vertical emittance of the beam extracted from the ring was increased by a large factor (4--20). The emittance slowly decreased as the vacuum pressure gradually improved. At the same time, an intermittent vertical instability was observed. Both the emittance blow-up and the instability behavior depended strongly on beam current, ring pressure, number of bunches in the ring (1 or 2), duty cycle, store time and betatron tunes. In this report, the authors describe the observations, and compare them with predictions from classical ion-trapping and ion-instability theories.


    Directory of Open Access Journals (Sweden)

    STANCIU Alexandru Lucian


    Full Text Available The article, as a new concept, analyzes the notion of « pulsating flow », the physical phenomenon seen when emptying bottles of PET or Tetra Pak; which do not have a disposal system of the vacuum created while emptying them, situation in which the fluid stream becomes oscillating in terms of the speed and the flow of the fluid passing through the drain area / section. Pulsating flow is a result of the vacuum created in the container, as opposed to laminar and turbulent flow whose existence is determined by the relative speed of the layers of fluid and the friction forces [2]. In the paper I present some new constructive solutions, designed by AutoCAD and created physically with rapid-prototyping

  14. Effect of vacuum packing and temperature on survival and hatching of strongyle eggs in faecal samples

    DEFF Research Database (Denmark)

    Sengupta, Mita Eva; Thapa, Sundar; Thamsborg, Stig Milan


    , and horses infected with Strongylus vulgaris and cyathostomins. The samples were allocated into four treatments: vacuum packing and storage at 5 °C or 20 °C (5 V and 20 V); normal packing in plastic gloves closed with a loose knot and storage at 5 °C or 20 °C (5 N and 20 N). The number of eggs per gram...... to normal storage, regardless of temperature. However, O. dentatum EPG was significantly higher in samples kept at 5 °C as compared to 20 °C, irrespective of packing. For the horse strongyles, vacuum packed samples at 5 °C had a significantly higher EPG compared to the other treatments after 28 days...

  15. Minicharged particles search by strong laser pulse-induced vacuum polarization effects

    Directory of Open Access Journals (Sweden)

    S. Villalba-Chávez


    Full Text Available Laser-based searches of the yet unobserved vacuum birefringence might be sensitive for very light hypothetical particles carrying a tiny fraction of the electron charge. We show that, with the help of contemporary techniques, polarimetric investigations driven by an optical laser pulse of moderate intensity might allow for excluding regions of the parameter space of these particle candidates which have not been discarded so far by laboratory measurement data. Particular attention is paid to the role of a Gaussian wave profile. It is argued that, at energy regimes in which the vacuum becomes dichroic due to these minicharges, the transmission probability of a probe beam through an analyzer set crossed to the initial polarization direction will depend on both the induced ellipticity as well as the rotation of the initial polarization plane. The weak and strong field regimes, relative to the attributes of these minicharged particles, and the relevance of the polarization of the strong field are investigated.

  16. A rotating quantum vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Lorenci, V.A. de; Svaiter, N.F. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)


    It was investigated which mapping has to be used to compare measurements made in a rotating frame to those made in an inertial frame. Using a non-Galilean coordinate transformation, the creation-annihilation operators of a massive scalar field in the rotating frame are not the same as those of an inertial observer. This leads to a new vacuum state(a rotating vacuum) which is a superposition of positive and negative frequency Minkowski particles. Polarization effects in circular accelerators in the proper frame of the electron making a connection with the inertial frame point of view were analysed. 65 refs.

  17. Effect of Vacuum Intrusion Compaction on the Mechanical Properties of Mortar


    Chung K.Y.; Sulieman M.Z.


    The Vacuum Intrusion Compaction Method (VICM) can be defined as a mortar or cement based material compaction method which applies the principle of air pressure in extracting air bubbles trapped in mortar in order to achieve the objective of compaction. This alternative compaction method is able to prevent segregation from happening in mortar and other cement based materials. It also provides better control over the orientation of the elements inside the mortar. Laboratory tests on the physica...

  18. The Effect of Thermal Fluctuation on the Receptor-Mediated Adhesion of a Cell Membrane to an Elastic Substrate

    Directory of Open Access Journals (Sweden)

    Bahador Marzban


    Full Text Available Mechanics of the bilayer membrane play an important role in many biological and bioengineering problems such as cell–substrate and cell–nanomaterial interactions. In this work, we study the effect of thermal fluctuation and the substrate elasticity on the cell membrane–substrate adhesion. We model the adhesion of a fluctuating membrane on an elastic substrate as a two-step reaction comprised of the out-of-plane membrane fluctuation and the receptor–ligand binding. The equilibrium closed bond ratio as a function of substrate rigidity was computed by developing a coupled Fourier space Brownian dynamics and Monte Carlo method. The simulation results show that there exists a crossover value of the substrate rigidity at which the closed bond ratio is maximal.

  19. The Effect of Climate, Environment and Man on Variations in Wildlife Population Fluctuations in Greenland Over 200 Years

    DEFF Research Database (Denmark)

    Moshøj, Charlotte Margaret


    The Effect of Climate, Environment and Man on Variations in Wildlife Population Fluctuations in Greenland Over 200 Years Moshøj, Charlotte The underlying factors of species fluctuating population dynamics has been the dominant focus of attention in population ecology throughout much of this century...... in the harvests of individual species are believed to be related to changes in climate, as well as variations in hunting pressure. Dating back 200 years, these hunting records therefore represent a unique time series for retrospective modelling of annual and decadal fluctuations in relation to long-term climatic...... data, environmental factors and temporal variations in social and demographic parameters in the existing society. The results of this study model future predictions of wildlife populations under changing climate variables and human hunting pressure. View Presentation....

  20. Quantum-fluctuation effects in the transport properties of ultrathin films of disordered superconductors above the paramagnetic limit. (United States)

    Khodas, M; Levchenko, A; Catelani, G


    We study the transport in ultrathin disordered film near the quantum critical point induced by the Zeeman field. We calculate corrections to the normal state conductivity due to quantum pairing fluctuations. The fluctuation-induced transport is mediated by virtual rather than real quasiparticle excitations. We find that at zero temperature, where the corrections come from purely quantum fluctuations, the Aslamazov-Larkin paraconductivity term, the Maki-Thompson interference contribution, and the density of states effects are all of the same order. The total correction leads to the negative magnetoresistance. This result is in qualitative agreement with the recent transport observations in the parallel magnetic field of the homogeneously disordered amorphous films and superconducting two-dimensional electron gas realized at the oxide interfaces.

  1. Experimental and theoretical studies of sequence effects on the fluctuation and melting of short DNA molecules

    Energy Technology Data Exchange (ETDEWEB)

    Peyrard, M; Cuesta-Lopez, S [Universite de Lyon, Ecole Normale Superieure de Lyon, Laboratoire de Physique, CNRS UMR 5672, 46 allee d' Italie, F-69364 Lyon Cedex 07 (France); Angelov, D [Universite de Lyon, Ecole Normale Superieure de Lyon, Laboratoire de Biologie Moleculaire de la Cellule, CNRS UMR 5239, 46 allee d' Italie, F-69364 Lyon Cedex 07 (France)], E-mail:


    Understanding the melting of short DNA sequences probes DNA at the scale of the genetic code and raises questions which are very different from those posed by very long sequences, which have been extensively studied. We investigate this problem by combining experiments and theory. A new experimental method allows us to make a mapping of the opening of the guanines along the sequence as a function of temperature. The results indicate that non-local effects may be important in DNA because an AT-rich region is able to influence the opening of a base pair which is about 10 base pairs away. An earlier mesoscopic model of DNA is modified to correctly describe the timescales associated with the opening of individual base pairs well below melting, and to properly take into account the sequence. Using this model to analyze some characteristic sequences for which detailed experimental data on the melting is available (Montrichok et al 2003 Europhys. Lett. 62 452), we show that we have to introduce non-local effects of AT-rich regions to get acceptable results. This brings a second indication that the influence of these highly fluctuating regions of DNA on their neighborhood can extend to some distance.

  2. Engineering Matter Interactions Using Squeezed Vacuum

    Directory of Open Access Journals (Sweden)

    Sina Zeytinoğlu


    Full Text Available Virtually all interactions that are relevant for atomic and condensed matter physics are mediated by quantum fluctuations of the electromagnetic field vacuum. Consequently, controlling the vacuum fluctuations can be used to engineer the strength and the range of interactions. Recent experiments have used this premise to demonstrate novel quantum phases or entangling gates by embedding electric dipoles in photonic cavities or wave guides, which modify the electromagnetic fluctuations. Here, we show theoretically that the enhanced fluctuations in the antisqueezed quadrature of a squeezed vacuum state allow for engineering interactions between electric dipoles without the need for a photonic structure. Thus, the strength and range of the interactions can be engineered in a time-dependent way by changing the spatial profile of the squeezed vacuum in a traveling-wave geometry, which also allows the implementation of chiral dissipative interactions. Using experimentally realized squeezing parameters and including realistic losses, we predict single-atom cooperativities C of up to 10 for the squeezed-vacuum-enhanced interactions.

  3. The effects of the vegetable prices insurance on the fluctuation of price: Based on Shanghai evidences (United States)

    Qu, Chunhong; Li, Huishang; Hao, Shuai; Zhang, Xuebiao; Yang, Wei


    Taking Shanghai as an example, the influence of the vegetable price insurance on the fluctuation of prices was analyzed in the article. It was found that the sequence of seasonal fluctuations characteristics of leafy vegetable prices was changed by the vegetable cost-price insurance, the period of price fluctuation was elongated from 12-to-18 months to 37 months, and the influence of random factors on the price fluctuations was reduced in some degree. There was still great space for innovation of the vegetable prices insurance system in Shanghai. Some countermeasures would be suggested to develop the insurance system to better to play the role of insurance and promote the market running more smoothly in Shanghai such as prolonging the insurance cycle, improving the price information monitoring mechanism and innovating income insurance products and so on.

  4. The effect of vacuum packaging, EDTA, oregano and thyme oils on the microbiological quality of chicken's breast. (United States)

    Pavelková, Adriana; Kačániová, Miroslava; Horská, Elena; Rovná, Katarína; Hleba, Lukáš; Petrová, Jana


    The effect of ethylenediaminetetraacetate (EDTA), oregano (Origanum vulgare) and thyme (Thymus vulgaris) oils, on the chicken breast fillets was examined in this study. The chicken breast fillets were stored under vacuum packaging (VP), at 4 ± 0.5 °C for a period of 18 days. There were used the following treatments of chicken breast fillets: Air-packaged (AC, control samples), vacuum-packaged (VPC, control samples), VP with EDTA solution 1.50% w/w (VPEC, control samples), VP with oregano oil 0.20% v/w (VP + O) and VP with thyme oil 0.20% v/w, (VP + T). The quality assessment for vacuum packaging of the product in accordance with the terms above and EDTA treatment, oregano and thyme oil was established by microbiological analyzes. The microbiological properties as the total viable counts on Plate Count Agar, after incubation for 2 days at 37 °C and coliform bacteria on Violet Red Bile Glucose agar incubated at 37 °C for 24 h, lactobacilli on Rogosa and Sharpe agar after incubation 48-78 h at 37 °C in an aerobic atmosphere supplemented with carbon dioxide (5% CO2) and Pseudomonas aeruginosa on Pseudomonas Isolation agar (PIA, Oxoid, UK) after incubation at 48 h at 35 °C were monitored. The using of oregano, thyme oil and EDTA with combination of vacuum packaging has significant effects to reduction of all followed groups of microorganisms compared with control group without vacuum packaging and untreated control group. The natural preservatives can be used as alternatives to chemical additives which could extend the meat and meat products shelf life. The knowledge about them can have an important economic feedback by reducing losses attributed to spoilage and by allowing the products to reach distant and new markets. This study shows how using of natural antimicrobials can extend the shelf-life of the meat product. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Manipulating lightcone fluctuations in an analogue cosmic string (United States)

    Hu, Jiawei; Yu, Hongwei


    We study the flight time fluctuations in an anisotropic medium inspired by a cosmic string with an effective fluctuating refractive index caused by fluctuating vacuum electric fields, which are analogous to the lightcone fluctuations due to fluctuating spacetime metric when gravity is quantized. The medium can be realized as a metamaterial that mimics a cosmic string in the sense of transformation optics. For a probe light close to the analogue string, the flight time variance is ν times that in a normal homogeneous and isotropic medium, where ν is a parameter characterizing the deficit angle of the spacetime of a cosmic string. The parameter ν, which is always greater than unity for a real cosmic string, is determined by the dielectric properties of the metamaterial for an analogue string. Therefore, the flight time fluctuations of a probe light can be manipulated by changing the electric permittivity and magnetic permeability of the analogue medium. We argue that it seems possible to fabricate a metamaterial that mimics a cosmic string with a large ν in laboratory so that a currently observable flight time variance might be achieved.

  6. Manipulating lightcone fluctuations in an analogue cosmic string

    Directory of Open Access Journals (Sweden)

    Jiawei Hu


    Full Text Available We study the flight time fluctuations in an anisotropic medium inspired by a cosmic string with an effective fluctuating refractive index caused by fluctuating vacuum electric fields, which are analogous to the lightcone fluctuations due to fluctuating spacetime metric when gravity is quantized. The medium can be realized as a metamaterial that mimics a cosmic string in the sense of transformation optics. For a probe light close to the analogue string, the flight time variance is ν times that in a normal homogeneous and isotropic medium, where ν is a parameter characterizing the deficit angle of the spacetime of a cosmic string. The parameter ν, which is always greater than unity for a real cosmic string, is determined by the dielectric properties of the metamaterial for an analogue string. Therefore, the flight time fluctuations of a probe light can be manipulated by changing the electric permittivity and magnetic permeability of the analogue medium. We argue that it seems possible to fabricate a metamaterial that mimics a cosmic string with a large ν in laboratory so that a currently observable flight time variance might be achieved.

  7. The ecological effects of water level fluctuation and phosphate enrichment in mesotrophic peatlands are strongly mediated by soil chemistry

    NARCIS (Netherlands)

    Mettrop, I.S.; Rutte, M.D.; Kooijman, A.M.; Lamers, L.P.M.


    Since the re-establishment of a more natural water regime is considered by water management in wetlands with artificially stable water levels, the biogeochemical and ecological effects of water level fluctuation with different nutrient loads should be investigated. This is particularly important for

  8. Effects of vole fluctuations on the population dynamics of the barn owl Tyto alba. (United States)

    Klok, Chris; de Roos, Andre M


    Many predator species feed on prey that fluctuates in abundance from year to year. Birds of prey can face large fluctuations in food abundance i.e. small mammals, especially voles. These annual changes in prey abundance strongly affect the reproductive success and mortality of the individual predators and thus can be expected to influence their population dynamics and persistence. The barn owl, for example, shows large fluctuations in breeding success that correlate with the dynamics in voles, their main prey species. Analysis of the impact of fluctuations in vole abundance (their amplitude, peaks and lows, cycle length and regularity) with a simple predator prey model parameterized with literature data indicates population persistence is especially affected by years with low vole abundance. In these years the population can decline to low owl numbers such that the ensuing peak vole years cannot be exploited. This result is independent of the length and regularity of vole fluctuations. The relevance of this result for conservation of the barn owl and other birds of prey that show a numerical response to fluctuating prey species is discussed.

  9. The effect of active fluctuations on the dynamics of particles, motors and hairpins

    CERN Document Server

    Vandebroek, Hans


    Inspired by recent experiments on the dynamics of particles and polymers in artificial cytoskeletons and in cells, we introduce a modified Langevin equation for a particle in an environment that is a viscoelastic medium and that is brought out of equilibrium by the action of active fluctuations caused by molecular motors. We show that within such a model, the motion of a free particle crosses over from superdiffusive to subdiffusive as observed for tracer particles in an {\\it in vitro} cytoskeleton or in a cell. We investigate the dynamics of a particle confined by a harmonic potential as a simple model for the motion of the tethered head of kinesin-1. We find that the probability that the head is close to its binding site on the microtubule can be enhanced by a factor of two due to active forces. Finally, we study the dynamics of a particle in a double well potential as a model for the dynamics of DNA-hairpins. We show that the active forces effectively lower the potential barrier between the two minima and ...

  10. Effects of temperature fluctuations on cuttlebone formation of cuttlefish Sepia esculenta (United States)

    Lei, Shuhan; Zhang, Xiumei; Liu, Songlin; Chen, Siqing


    The morphological characteristics and the cuttlebone formation of Sepia esculenta exposed to different water temperature fluctuations were investigated under laboratory conditions. Temperature fluctuation cycles (15 cycles, 60 d in total) consisted of the following three regimes of 4 d duration: keeping water temperature in 26°C for 3 d (Group A), 2 d (Group B), 0 d (Group C, control); then keeping water temperature in 16°C for the next 1, 2, 4 d. No significant difference in the survival rate was observed between the control and temperature fluctuation groups ( P >0.05). Lamellar depositions in a temperature fluctuation cycle were 2.45±0.02 for Group A, 2.00±0.02 for Group B, and 1.78±0.02 for Group C ( P< 0.05). The relationship between age and number of lamellas in the cuttlebone of S. esculenta under each water temperature fluctuation could be described as the linear model and the number of lamellas in the cuttlebone did not correspond to actual age. Group A had the highest cuttlebone growth index (CGI), the lowest locular index (LI), and inter-streak distances comparing with those of control group. However, the number of lamellas and LI or CGI showed a quadratic relationship for each temperature fluctuation group. In addition, temperature fluctuations caused the breakage of cuttlebone dark rings, which was considered a thermal mark. The position of the breakage in the dark rings was random. This thermal mark can be used as supplementary information for marking and releasing techniques.

  11. Effect of intestinal pressure on fistula closure during vacuum assisted treatment: a computational approach. (United States)

    Cattoni, Diego I; Ravazzola, Constanza; Tüngler, Victoria; Wainstein, Daniel E; Chara, Osvaldo


    Enterocutaneous fistulae, pathological communications between the intestinal lumen and the abdominal skin, can arise as serious complication of gastrointestinal surgery. A current non-surgical treatment for this pathology involves topical application of sub-atmospheric pressure, also known as vacuum assisted closure (VAC). While this technique appears to be promising, surgeons report a number of cases in which its application fails to achieve fistula closure. Here, we evaluate the fistula's physical properties during the vacuum assisted closure process in a computational approach exploring the relevance of intraluminal intestinal pressure. A mathematical model formulated by differential equations based on tissue elasticity properties and principles of fluid mechanics was created and forcing functions were integrated to mimic intestinal pressure dynamics. A software to solve equations and to fit the model to experimentally obtained data was developed. This enabled simulations of vacuum assisted fistula closure under different intestinal pressure. The simulation output indicates conditions, in which fistula closure can or cannot be expected suggesting favoured or impeded healing, respectively. When modifications of intestinal pressure, as observed in fistula accompanying pathologies, are integrated, the outcome of fistula closure changes considerably. Rise of intestinal pressure is associated with delay of fistula closure and temporary fistula radius augmentation, while reduction of intestinal pressure during sub-atmospheric pressure treatment contributes to a faster and direct fistula closure. From the model predictions, we conclude that administration of intestinal pressure decreasing compounds (e.g. butylscopolamine, glucagon) may improve VAC treatment, while intestinal pressure increasing drugs should be avoided. Copyright © 2011 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

  12. Effect of thermal treatment in vacuum on Fe-doped SnO{sub 2} powders

    Energy Technology Data Exchange (ETDEWEB)

    Bilovol, V. [Laboratorio de Solidos Amorfos, INTECIN, Facultad de Ingenieria, Universidad de Buenos Aires, Paseo Colon 850, C1063ACV Buenos Aires (Argentina); Mudarra Navarro, A.M.; Rodriguez Torres, C.E. [Departamento de Fisica, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, IFLP-CCT La Plata, CONICET (Argentina); Cabrera, A.F., E-mail: [Departamento de Fisica, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, IFLP-CCT La Plata, CONICET (Argentina)


    A sample of 10 at% Fe-doped SnO{sub 2} powder was prepared by mechanical alloying and then thermally treated at 773 K in vacuum. The fit of the diffraction patterns and X-ray absorption spectroscopy measurements revealed that the as milled sample was pure doped rutile. Fe dissolved into SnO{sub 2} was found in Fe{sup 2+}/Fe{sup 3+} ionic valence with mainly paramagnetic behavior. After the thermal treatment all techniques indicate the formation of the ternary Sn{sub 0.36}Fe{sub 2.64}O{sub 4} spinel phase, which is responsible for the observed ferromagnetism.

  13. Vacuum-free, cost-effective, developing-country-material-available solar cell encapsulation

    Energy Technology Data Exchange (ETDEWEB)

    Dross, Frederic; Labat, Ariane; Antonio Perez Lopez, Mauro; Antonio Perez Lopez, Marco; Raudez, Rudolfo; Bruce, Anna; Kinne, Susan; Komp, Richard [Grupo Fenix, UNI, Managua (Nicaragua)


    We describe a novel cast encapsulation method based on room-temperature vulcanizing (RTV) silicone. This method does not require vacuum, nor lamination, and all the material needed, except for the encapsulant itself is available in developing countries. It is successfully used in Nicaragua. In addition, we report in detail on a recently developed solution to limit trapping of bubbles in the encapsulant during curing. We deposit, prior to encapsulation, a thin film of RTV silicone on the cells. The resulting solar panels made using this technique show a lot less trapped bubbles. (author)

  14. Short wavelength fluctuation effects on the magnetization in type I and low-kappa type II superconductors

    CERN Document Server

    Mosqueira, J; Curras, S R; González, M T; Ramallo, M V; Ruibal, M; Torron, C; Vidal, F


    The effects on the magnetization of fluctuating Cooper pairs created above the superconducting transition by thermal agitation energy (the so-called fluctuation-induced diamagnetism, FD) have been measured in a clean type I superconductor (Pb) and in a clean low Ginzburg-Landau parameter (kappa) type II superconductor (Nb). These experiments extend the earlier measurements of Gollub, Beasley and Tinkham to both the high reduced temperature region (epsilon ident to ln (T/T sub C sub 0) approx> 0.1) and the high reduced magnetic field region (h ident to H/H sub C sub 2 (0) approx> 0.1). Our data show that in spite of FD being deeply affected in both superconductors by the presence of non-local electrodynamic effects, the superconducting fluctuations sharply vanish when epsilon or h become of the order of 0.5 and, respectively, 1. This short-wavelength behaviour at high reduced temperatures of the superconducting fluctuations is similar to that previously observed at high reduced temperatures in dirty low-T sub ...

  15. Simulated Seasonal Photoperiods and Fluctuating Temperatures Have Limited Effects on Blood Feeding and Life History in Aedes triseriatus (Diptera: Culicidae) (United States)

    Westby, K. M.


    Biotic and abiotic factors change seasonally and impact life history in temperate-zone ectotherms. Temperature and photoperiod are factors that change in predictable ways. Most studies testing for effects of temperature on vectors use constant temperatures and ignore potential correlated effects of photoperiod. In two experiments, we tested for effects of larval rearing environments creating ecologically relevant temperatures and photoperiods simulating early and late season conditions (June and August), or constant temperatures (cool and warm) with the June or August photoperiods, respectively. We determined effects on survivorship, development, size, and a composite performance index in a temperate-zone population of Aedes triseriatus (Say). We followed cohorts of resulting females, all held under the same environmental conditions, to assess carry-over effects of rearing conditions for larvae on longevity, blood feeding, and egg production. Larval survivorship was affected by treatment in one experiment. Development time was greater in the June and cool treatments, but the constant and fluctuating temperatures did not differ. Significantly larger mosquitoes were produced in fluctuating versus constant temperature treatments. There were no significant treatment effects on the composite performance index. Adult female longevity was lower after rearing at constant versus fluctuating temperature, but there was no difference between June and August, nor did size affect longevity. There was no effect of treatments on blood feeding and a limited effect on egg production. We conclude that seasonal temperatures and photoperiods during development have limited effects on this population of A. triseriatus and find little evidence of strong effects of fluctuating versus constant temperatures. PMID:26336255

  16. Effect of ageing time in vacuum package on veal longissimus dorsi and biceps femoris physical and sensory traits

    Directory of Open Access Journals (Sweden)

    G. Baldi


    Full Text Available Study evaluated the effects of vacuum ageing (2, 4, 6, 8, 10, 12, 16 days on veal loin (longissimus dorsi; LD and silverside (biceps femoris; BF physical and sensory characteristics. Ageing did not affect cooking loss, increased LD pH and L*, a* and b* in both muscles. Shear force (SF decreased until day 6 in LD and day 10 in BF. Aroma, flavor and taste were not affected, while texturetraits were improved. SF was negative correlated with tenderness and juiciness and positive correlated with BF fibrousness and stringy sensation. Ageing improved texture properties withoutaltering other sensory traits.

  17. Revealing the subtle interplay of thermal and quantum fluctuation effects on contact ion pairing in microsolvated HCl. (United States)

    Walewski, Łukasz; Forbert, Harald; Marx, Dominik


    The combined effect of thermal fluctuations and quantum mechanical motion on the HCl(H2O)4 cluster is studied at different temperatures. Two conformations of this cluster are investigated: the ringlike structure that involves an undissociated HCl molecule (UD) and the contact ion pair (CIP), which involves the dissociated acid, Cl(-), and H3O(+). The UD structure is affected by thermal and quantum fluctuations in a similar way. The hydrogen-bond network is destabilized, and this results in ring expansion and proton orientational rearrangements, though the thermal excitation prevails over the quantum effects at high temperature, while the zero-point motion dominates in the low-temperature regime, as expected. In contrast, the thermal and quantum fluctuations exert competing effects on the CIP structure. At high temperature one of the hydrogen bonds accepted by Cl(-) breaks, and this results in undercoordination of the Cl site, which leads to proton transfer along the fluxional Cl(-)···H3O(+) hydrogen bond and formation of molecular HCl. Thus, thermal fluctuations counteract acid dissociation and thus ion-pair formation. At low temperature however, the decreasing thermal excitations facilitate recovery of the full hydrogen-bond network, which pushes the proton away from the Cl site and thus leads to acid dissociation, which characterizes the equilibrium structure. On the other hand, quantum mechanical fluctuations, which destabilize the hydrogen bonds supporting the Cl(-) ion and pull the proton back towards the undissociated limit, become of overriding importance in the low-temperature limit. As a result, the subtle balance between the two trends enables temperature-dependent "low-barrier hydrogen bonding" and establishes a centered hydrogen bond, H2O···H(+)···Cl(-), at intermediate temperatures. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Monitoring noise-resonant effects in cancer growth influenced by external fluctuations and periodic treatment (United States)

    Fiasconaro, A.; Ochab-Marcinek, A.; Spagnolo, B.; Gudowska-Nowak, E.


    We investigate a mathematical model describing the growth of tumor in the presence of immune response of a host organism. The dynamics of tumor and immune cells populations is based on the generic Michaelis-Menten kinetics depicting interaction and competition between the tumor and the immune system. The appropriate phenomenological equation modeling cell-mediated immune surveillance against cancer is of the predator-prey form and exhibits bistability within a given choice of the immune response-related parameters. Under the influence of weak external fluctuations, the model may be analyzed in terms of a stochastic differential equation bearing the form of an overdamped Langevin-like dynamics in the external quasi-potential represented by a double well. We analyze properties of the system within the range of parameters for which the potential wells are of the same depth and when the additional perturbation, modeling a periodic treatment, is insufficient to overcome the barrier height and to cause cancer extinction. In this case the presence of a small amount of noise can positively enhance the treatment, driving the system to a state of tumor extinction. On the other hand, however, the same noise can give rise to return effects up to a stochastic resonance behavior. This observation provides a quantitative analysis of mechanisms responsible for optimization of periodic tumor therapy in the presence of spontaneous external noise. Studying the behavior of the extinction time as a function of the treatment frequency, we have also found the typical resonant activation effect: For a certain frequency of the treatment, there exists a minimum extinction time.

  19. Opposing Effects of Intrinsic Conductance and Correlated Synaptic Input on V-Fluctuations during Network Activity

    DEFF Research Database (Denmark)

    Kolind, Jens; Hounsgaard, Jørn Dybkjær; Berg, Rune W


    Neurons often receive massive concurrent bombardment of synaptic inhibition and excitation during functional network activity. This increases membrane conductance and causes fluctuations in membrane potential (V(m)) and spike timing. The conductance increase is commonly attributed to synaptic......(m) -fluctuations and conductance observed experimentally during functional network activity leave little room for intrinsic conductance to contribute. Even without intrinsic conductances the variance in V(m) -fluctuations can only be explained by a high degree of correlated firing among presynaptic neurons....... conductance, but also includes the intrinsic conductances recruited during network activity. These two sources of conductance have contrasting dynamic properties at sub-threshold membrane potentials. Synaptic transmitter gated conductance changes abruptly and briefly with each presynaptic action potential...

  20. Effect of work:rest cycle duration on [Formula: see text] fluctuations during intermittent exercise. (United States)

    Combes, Adrien; Dekerle, Jeanne; Bougault, Valérie; Daussin, Frédéric N


    The succession of on-transient phases that induce a repetition of metabolic changes is a possible mechanism responsible for the greater response to intermittent training (IT). The objective of this study was to quantify [Formula: see text] fluctuations during intermittent exercise characterised by the same work:rest ratio, but different durations and identify which duration leads to the greatest fluctuations. Ten participants (24 ± 5 years; [Formula: see text]: 42 ± 7 mL·min(-1)·kg(-1)) performed (1) an incremental test to exhaustion to determine peak work rate (WRpeak) and oxygen uptake ([Formula: see text]), (2), and three 1 h intermittent exercises alternating work period at 70% WRpeak with passive recovery period of different 1:1 work:recovery duty cycles (30 s:30 s, 60 s:60 s, 120 s:120 s). [Formula: see text] response analysis revealed differences in the fluctuations across the intermittent conditions despite an identical total energy expenditure. The sum of the cycle's nadir-to-peak [Formula: see text] differences (ΣΔ[Formula: see text]) and the oxygen fluctuation index (OFI) were both greater in the 60 s:60 s condition (ΣΔ[Formula: see text]: +38% ± 13% and +19% ± 18% vs. 120 s:120 s and 30 s:30 s, P intermittent condition associated with the greatest disturbances: the 60 s:60 s duty cycle induces more [Formula: see text] fluctuations. The present findings also demonstrate that the selection of the duty cycle duration for submaximal intermittent exercise (70% of WRpeak) prescription is of interest to produce high [Formula: see text] fluctuations.

  1. Effects of ion temperature fluctuations on the stability of resistive ballooning modes

    Energy Technology Data Exchange (ETDEWEB)

    Singh, R. [Inst. for Plasma Research, Bhat, Gandhinagar (India); Nordman, H.; Jarmen, A.; Weiland, J. [Chalmers Univ. of Technology, Goeteborg (Sweden). Inst. for Electromagnetic Field Theory and Plasma Physics


    The influence of ion temperature fluctuations on the stability of resistive drift- and ballooning-modes is investigated using a two-fluid model. The Eigenmode equations are derived and solved analytically in a low beta model equilibrium. Parameters relevant to L-mode edge plasmas from the Texas Experimental Tokamak are used. The resistive modes are found to be destabilized by ion temperature fluctuations over a broad range of mode numbers. The scaling of the growth rate with magnetic shear and mode number is elucidated. 13 refs, 4 figs.

  2. Dynamic octahedral fluctuations and the effects on orbital ordering in YTiO3

    Energy Technology Data Exchange (ETDEWEB)

    Li, Bing [University of Virginia; Louca, Despina [University of Virginia; Hu, Biao [University of Texas at Austin; Niedziela, Jennifer L [ORNL; Zhou, Jianshi [University of Texas at Austin; Goodenough, J. B. [University of Texas at Austin


    YTiO3 is revisited to investigate the influence of local lattice dynamics on orbital ordering using inelastic neutron scattering. Orbital order survives well above the ferromagnetic transition, into the paramagnetic state, but what eventually leads to disorder is not well understood. By probing the local lattice dynamics via the dynamic pair density function analysis, it is found that local fluctuations associated with octahedral tilting and rotational modes and Y displacements persist up to 60 meV. The local fluctuations exhibit a temperature dependence that may lead to the suppression of the Ti orbital overlap leading to a temperature dependent orbital disorder.

  3. Cosmology, quantum vacuum and zeta functions

    Energy Technology Data Exchange (ETDEWEB)

    Odintsov, Sergey D. [Campus UAB, Facultat de Ciencies, Bellaterra (ES). Inst. Catalana de Recerca i Estudis Avancats (ICREA) and Inst. de Ciencies de l' Espai (IEEC-CSIC); Saez-Gomez, Diego [Campus UAB, Facultat de Ciencies, Bellaterra (Spain). Inst. de Ciencies de l' Espai ICE-CSIC/IEEC; Xambo-Descamps, Sebastian (eds.) [Univ. Politecnica de Catalunya, Barcelona (Spain). Dept. de Matematica Aplicada 2


    Some major developments of physics in the last three decades are addressed by highly qualified specialists in different specific fields. They include renormalization problems in QFT, vacuum energy fluctuations and the Casimir effect in different configurations, and a wealth of applications. A number of closely related issues are also considered. The cosmological applications of these theories play a crucial role and are at the very heart of the book; in particular, the possibility to explain in a unified way the whole history of the evolution of the Universe: from primordial inflation to the present day accelerated expansion. Further, a description of the mathematical background underlying many of the physical theories considered above is provided. This includes the uses of zeta functions in physics, as in the regularization problems in QFT already mentioned, specifically in curved space-time, and in Casimir problems. (orig.)

  4. Effect of Air and Vacuum Storage on the Degradation of X-Ray-Exposed Aluminized-Teflon Investigated (United States)

    deGroh, Kim K.; Gummow, Jonathan D.


    Metalized Teflon FEP (fluorinated ethylene propylene, DuPont), a common thermal control material, has been found to degrade in the low-Earth-orbit space environment. The aluminized-FEP (Al-FEP) exterior layer on the Hubble Space Telescope has become extremely embrittled, with extensive cracking occurring on all sides of the telescope. This embrittlement has been primarily attributed to radiation exposure (x-rays from solar flares, electron/proton radiation, and possibly near-ultraviolet radiation) combined with thermal cycling. Limited samples of FEP tested after long-term exposure to low Earth orbit on the Hubble Space Telescope and on the Long Duration Exposure Facility indicated that there might be continued degradation in tensile properties over time. An investigation was conducted at the NASA Glenn Research Center to evaluate the effect of air and vacuum storage on the mechanical properties of x-ray-exposed FEP. Aluminized-FEP (5-mil-thick) tensile samples were x-ray exposed with 15.3-kV copper xrays for 2 hr, reducing the percent elongation to failure by approximately 50 percent in comparison to that for pristine Al-FEP. X-ray-exposed samples were stored in air or under vacuum for various time periods to see the effect of storage on tensile properties. Tensile results indicated that samples stored in air had larger decreases in tensile properties than samples stored under vacuum had, as seen in the graph. Samples stored under vacuum (for up to 400 hr) showed no further decrease in tensile properties over time, whereas samples stored in air (for up to 900 hr) appeared to show decreases in tensile properties over time. X-ray-exposed samples stored in air developed a hazy appearance in the exposed area, as seen in the photographs. When the source of the haziness was evaluated using scanning electron microscopy and atomic force microscopy, it was found to reside at the Al/FEP interface as witnessed by an increased surface roughness of the aluminized side of the

  5. The effect of boundary layer and surface characteristics on non-Gaussian turbulent fluctuations of temperature (United States)

    Graf, A.; Schüttemeyer, D.; Geiß, H.; Knaps, A.; Möllmann-Coers, M.; Schween, J. H.; Kollet, S.; Neininger, B.; Herbst, M.; Vereecken, H.


    We use simultaneously measured near-ground micrometeorological and boundary layer data to examine the relation between the probability density function (PDF) of a turbulent scalar such as temperature and its vertical profile. Turbulent temperature time series of 10 to 20 s-1 resolution are taken from eddy covariance stations measuring at 1.45 to 120 m above ground level, and vertical profiles of potential temperature were composed of tower and aircraft measurements. The relation between skewness and kurtosis of the turbulent near-ground data was evaluated using the Pearson system of distributions, and indicates that a part of their non-Gaussianity is due to the existence of a well-defined lower limit to fluctuations. To a lesser extend, an upper limit is also indicated. During unstable situations, the lower limit could be related to the minimum of potential temperature available in the boundary layer. During stable situations, it was related to the effective surface temperature at the measurement site estimated from outgoing longwave radiation. The upper limit could be related with considerably less rigidity and a systematic underestimation, which we attribute to well mixing by small-scale turbulence, to the surface temperature during unstable situations. Two types of theoretical PDFs are compared to the turbulent histograms. The first type, the beta distribution was empirically chosen from classical statistics based on matching the first four sample moments and has already been used to empirically model scalar concentrations in plumes. The second type was theoretically derived from simplified assumptions on atmospheric dispersion. Both support the assumption that turbulent scalar PDFs in horizontally homogeneous conditions have finite tails.

  6. Quantum effect on the internal proton transfer and structural fluctuation in the H+ 5 cluster. (United States)

    Ohta, Yasuhito; Ohta, Koji; Kinugawa, Kenichi


    The thermal equilibrium state of H+(5) is investigated by means of an ab initio path integral molecular dynamics (PIMD) method, in which degrees of freedom of both nuclei and electrons at finite temperature are quantized within the adiabatic approximation. The second-order Moller-Plesset force field has been employed for the present ab initio PIMD. At 5-200 K, H+(5) is shown to have the structure that the proton is surrounded by the two H(2) units without any exchange of an atom between the central proton and the H(2) unit. At 5 K, the quantum tunneling of the central proton occurs more easily when the distance between the two H(2) units is shortened. At the high temperature of 200 K, the central proton is more delocalized in space between the two H(2) units, with less correlation with the stretching of the distance between the two H(2) units. As for the rotation of the H(2) units around the C(2) axis of H+(5) , the dihedral angle distribution is homogeneous at all temperatures, suggesting that the two H(2) units freely rotate around the C(2) axis, while this quantum effect on the rotation of the H(2) units becomes more weakened with increasing temperature. The influence of the structural fluctuation of H+(5) on molecular orbital energies has been examined to conclude that the highest occupied molecular orbital-lowest unoccupied molecular orbital energy gap is largely reduced with the increase of temperature because of the spatial expansion of the whole cluster. (c) 2004 American Institute of Physics.

  7. The Warburg effect as an adaptation of cancer cells to rapid fluctuations in energy demand.

    Directory of Open Access Journals (Sweden)

    Tamir Epstein

    Full Text Available To maintain optimal fitness, a cell must balance the risk of inadequate energy reserve for response to a potentially fatal perturbation against the long-term cost of maintaining high concentrations of ATP to meet occasional spikes in demand. Here we apply a game theoretic approach to address the dynamics of energy production and expenditure in eukaryotic cells. Conventionally, glucose metabolism is viewed as a function of oxygen concentrations in which the more efficient oxidation of glucose to CO2 and H2O produces all or nearly all ATP except under hypoxic conditions when less efficient (2 ATP/ glucose vs. about 36ATP/glucose anaerobic metabolism of glucose to lactic acid provides an emergency backup. We propose an alternative in which energy production is governed by the complex temporal and spatial dynamics of intracellular ATP demand. In the short term, a cell must provide energy for constant baseline needs but also maintain capacity to rapidly respond to fluxes in demand particularly due to external perturbations on the cell membrane. Similarly, longer-term dynamics require a trade-off between the cost of maintaining high metabolic capacity to meet uncommon spikes in demand versus the risk of unsuccessfully responding to threats or opportunities. Here we develop a model and computationally explore the cell's optimal mix of glycolytic and oxidative capacity. We find the Warburg effect, high glycolytic metabolism even under normoxic conditions, is represents a metabolic strategy that allow cancer cells to optimally meet energy demands posed by stochastic or fluctuating tumor environments.

  8. Adaptation and prosthesis effects on stride-to-stride fluctuations in amputee gait.

    Directory of Open Access Journals (Sweden)

    Shane R Wurdeman

    Full Text Available Twenty-four individuals with transtibial amputation were recruited to a randomized, crossover design study to examine stride-to-stride fluctuations of lower limb joint flexion/extension time series using the largest Lyapunov exponent (λ. Each individual wore a "more appropriate" and a "less appropriate" prosthesis design based on the subject's previous functional classification for a three week adaptation period. Results showed decreased λ for the sound ankle compared to the prosthetic ankle (F1,23 = 13.897, p = 0.001 and a decreased λ for the "more appropriate" prosthesis (F1,23 = 4.849, p = 0.038. There was also a significant effect for the time point in the adaptation period (F2,46 = 3.164, p = 0.050. Through the adaptation period, a freezing and subsequent freeing of dynamic degrees of freedom was seen as the λ at the ankle decreased at the midpoint of the adaptation period compared to the initial prosthesis fitting (p = 0.032, but then increased at the end compared to the midpoint (p = 0.042. No differences were seen between the initial fitting and the end of the adaptation for λ (p = 0.577. It is concluded that the λ may be a feasible clinical tool for measuring prosthesis functionality and adaptation to a new prosthesis is a process through which the motor control develops mastery of redundant degrees of freedom present in the system.

  9. The effect of plasma fluctuations on parallel transport parameters in the SOL

    DEFF Research Database (Denmark)

    Havlíčková, E.; Fundamenski, W.; Naulin, Volker


    in the scrape-off layer (SOL) taking into account these fluctuations is presented. Plasma transport in the SOL along the magnetic field between two targets is calculated by a one-dimensional fluid code in order to estimate the response to transient conditions along the SOL and the attention is given...

  10. Effects of rapid temperature fluctuations prior to breeding on reproductive efficiency in replacement gilts (United States)

    Recently, we determined that rapidly cooling pigs after acute heat stress (HS) resulted in a pathological condition, and because rapid temperature fluctuations are often associated with reduced reproductive success in sows it lends itself to the hypothesis that these conditions may be linked. Study ...

  11. The effect of interaural-time-difference fluctuations on apparent source width

    DEFF Research Database (Denmark)

    Käsbach, Johannes; May, Tobias; Oskarsdottir, Gudrun


    For the perception of spaciousness, the temporal fluctuations of the interaural time differences (ITDs) and interaural level differences (ILDs) provide important binaural cues. One major characteristic of spatial perception is apparent source width (ASW), which describes the perceived width of a ...

  12. Fluctuating functions related to quality of life in advanced Parkinson disease: effects of duodenal levodopa infusion

    DEFF Research Database (Denmark)

    Isacson, D; Bingefors, K; Sønbø Kristiansen, Ivar


    OBJECTIVE: To assess fluctuations in quality of life (QoL) and motor performance in patients with advanced Parkinson disease (PD) treated with continuous daytime duodenal levodopa/carbidopa infusion or conventional therapy. METHODS: Of 18 patients completing a 6-week trial (DIREQT), 12 were...

  13. The effects of anterior vacuum disc on surgical outcomes of degenerative versus spondylolytic spondylolisthesis: at a minimum two-year follow-up. (United States)

    Lin, Tung-Yi; Liao, Jen-Chung; Tsai, Tsung-Ting; Lu, Meng-Ling; Niu, Chi-Chien; Chen, Wen-Jer; Chen, Lih-Hui


    The vacuum phenomenon within the intervertebral disc usually represents disc degeneration. There are no reports in the English literature that focus on the effect of an anterior vacuum disc on surgical outcome of same-segment spondylolisthesis. Patients with degenerative spondylolisthesis (DS) or isthmic spondylolisthesis (IS) who underwent a spinal surgery between January 2005 and December 2006 were reviewed. Patients who met certain criteria, including (1) only mono-segment spondylolisthesis, (2) gas air within the disc space of the spondylolisthesis segment on preoperative radiographs, (3) having received posterior decompression, posterior pedicle screw fixation, and posterolateral fusion, and (4) at least 12 months of follow-up radiographs available to define the posterolateral fusion rate, were enrolled into the study. Four radiographic parameters (disc height, translation, intradiscal angle, segmental angle) were assessed. Two-year postoperative radiographs were used to determine whether the posterolateral segment was fused or not. Clinical outcome and complications during the follow-up period were documented. Incidence of the disc vacuum phenomenon was significantly higher in the IS group than in the DS group (p vacuum phenomenon is not equal to anterior instability absolutely. Determination of stability or instability in a vacuum disc should be considered by a combination of dynamic radiographs. In the present study, vacuum discs in the DS group showed more instability and a higher posterolateral pseudoarthrosis rate.

  14. Effect of drying methods with the application of vacuum microwaves on the bioactive compounds, color, and antioxidant activity of strawberry fruits. (United States)

    Wojdyło, Aneta; Figiel, Adam; Oszmiański, Jan


    The objective of this study was to evaluate the application of vacuum-microwave drying (240, 360, and 480 W) in the production process of dehydrated strawberry and to compare and contrast the quality of these dehydrated strawberries in terms of their polyphenol compounds, concentration of some heat liable components, and color to that of freeze-dried, convective, and vacuum-dried strawberry. Thus, the effect of vacuum-microwave drying and other drying methods on the antioxidant activity of berries was evaluated. Whole fresh and dried fruits were assessed for phenolics (anthocyanins, flavanols, hydroxycinnamic acids, and flavonols), ascorbic acid, and antioxidant activity (all parameters were calculated on a dry matter basis). Analysis of data shows that ellagic acid and flavanol changes were affected by drying techniques and cultivar. Drying destroyed anthocyanins, flavanols, and ascorbic acid, and there was a significant decrease in antioxidant activity. The most striking result was that conventional and vacuum drying decreased antioxidant activity in both cultivars, whereas contradictory results were found for vacuum-microwave processed strawberry. This study has demonstrated that vacuum-microwave drying, especially at 240 W, can produce high-quality products, with the additional advantage of reduced processing times, compared to other processes such as freeze-drying.

  15. Effect of hydration on the electrical explosion of a fine palladium wire in a vacuum (United States)

    Sarkisov, G. S.


    Experiments with fast electric explosion of a hydrated palladium wire in vacuum show a significant decrease in Joule deposited energy, expansion rate, and voltage amplitude at breakdown. An increase in the density of diffused hydrogen and oxygen at the wire surface leads to an early generation of plasma due to evaporation impurity and rapid development of avalanche breakdown along the wire surface. The non-hydrated Pd wire demonstrates a longer resistive time, higher voltage peak, greater energy and expansion speed. The decrease in the deposited energy was ˜35%, and the expansion rate was ˜18%. The peak of light emission during voltage breakdown was twice higher for a hydrated Pd wire than for a bare one.

  16. Effects of various vacuum cleaners on the airborne content of major cat allergen (Fel d 1). (United States)

    de Blay, F; Spirlet, F; Gries, P; Casel, S; Ott, M; Pauli, G


    It has been shown that a vacuum cleaner (VC) can increase airborne cat allergen levels. This study aimed to compare the degree of leakage of airborne Fel d 1 levels among five different VCs, both under laboratory conditions and in an apartment with cats. Three of the VCs were marketed as antiallergic: a HEPA filter VC (VC A), a water impingement and HEPA filter VC (VC B), and a foam fabric filter VC (VC C). The other two were standard VCs: VC D and VC E. VCs were tested in a 20 m3, airtight, experimental room and in a 53 m3 living room in an apartment with three cats. Air was sampled with a glass-fiber filter and an impinger at 20 l/min for 30 min before, during, and after vacuuming. Airborne Fel d 1 was measured with a two-site monoclonal ELISA assay. In the experimental room, no airborne Fel d 1 level was measured before using the VCs. After introducing a dust sample containing Fel d 1 in the VCs, we found that VCs A, B, and E did not provoke any increase in airborne Fel d 1. In contrast, VCs C and D significantly increased airborne Fel d 1 levels (GM: 4.9 and 5.3 ng/m3, respectively). In the apartment, all VCs induced an increase in airborne Fel d 1, which was carried by particles greater than 5 microm. However, VCs C and D provoked significantly greater increases in airborne Fel d 1 than VCs A, B, and E (P=0.0001). Our results suggest that: 1) The two VCs with leakage in the experimental room had greater leakages in the apartment. 2) In the apartment with cats, all VCs provoked increases in airborne Fel d 1, primarily carried by large particles. 3) Given the increased marketing of "antiallergic" VCs, further studies are needed to standardize methods for testing airborne allergen leakage by VCs.

  17. Effect of the collective motions of molecules inside a condensed phase on fluctuations in the density of small bodies (United States)

    Tovbin, Yu. K.


    An approach to calculating the effects of fluctuations in density that considers the collective motions of molecules in small condensed phases (e.g., droplets, microcrystals, adsorption at microcrystal faces) is proposed. Statistical sums of the vibrational, rotational, and translational motions of molecules are of a collective character expressed in the dependences of these statistical sums on the local configurations of neighboring molecules. This changes their individual contributions to the free energy and modifies fluctuations in density in the inner homogeneous regions of small bodies. Interactions between nearest neighbors are considered in a quasi-chemical approximation that reflects the effects of short-range direct correlations. Expressions for isotherms relating the densities of mixture components to the chemical potentials in a thermostat are obtained, along with equations for pair distribution functions.

  18. A comprehensive model to determine the effects of temperature and species fluctuations on reaction rates in turbulent reacting flows (United States)

    Foy, E.; Ronan, G.; Chinitz, W.


    A principal element to be derived from modeling turbulent reacting flows is an expression for the reaction rates of the various species involved in any particular combustion process under consideration. A temperature-derived most-likely probability density function (pdf) was used to describe the effects of temperature fluctuations on the Arrhenius reaction rate constant. A most-likely bivariate pdf described the effects of temperature and species concentrations fluctuations on the reaction rate. A criterion is developed for the use of an "appropriate" temperature pdf. The formulation of models to calculate the mean turbulent Arrhenius reaction rate constant and the mean turbulent reaction rate is considered and the results of calculations using these models are presented.

  19. Effect of worldwide oil price fluctuations on biomass fuel use and child respiratory health: evidence from Guatemala. (United States)

    Venkataramani, Atheendar S; Fried, Brian J


    We examined the effect of worldwide oil price fluctuations on household fuel use and child respiratory health in Guatemala. We regressed measures of household fuel use and child respiratory health on the average worldwide oil price and a rich set of covariates. We leveraged variation in oil prices over the 6-month period of the survey to identify associations between fuel prices, fuel choice, and child respiratory outcomes. A $1 (3.4% point) increase in worldwide fuel prices was associated with a 2.8% point decrease in liquid propane gasoline use (P oil prices and the fuel choice indicators was largest for households in the middle of the income distribution. Fluctuations in worldwide fuel prices affected household fuel use and, consequently, child health. Policies to help households tide over fuel price shocks or reduce pollution from biomass sources would confer positive health benefits. Such policies would be most effective if they targeted both poor and middle-income households.

  20. Longitudinal analysis of the effect of academic failure tolerance on academic achievement fluctuation in medical school students


    Su Jin Chae; Miran Kim; Ki Hong Chang


    Purpose: Academic failure tolerance (AFT) is one of the important psychological concepts in education, but its applications in medical education are rare. Thus, the purpose of this study was to investigate the effect of academic failure tolerance on academic achievement fluctuation among medical school students using a longitudinal research design. Methods: The subjects were 43 medical students who responded to the AFT test. This study analyzed the longitudinal data of achievement scores up t...

  1. Effect of far-infrared radiation assisted microwave-vacuum drying on drying characteristics and quality of red chilli. (United States)

    Saengrayap, Rattapon; Tansakul, Ampawan; Mittal, Gauri S


    Fresh red chilli (Capsicum frutescens L.) was dried using microwave-vacuum drying (MVD) and the far-infrared radiation assisted microwave-vacuum drying (FIR-MVD) method. The MVD was operated using the microwave power of 100, 200 and 300 W under absolute pressure of 21.33, 28.00 and 34.66 kPa. In terms of FIR-MVD, far-infrared power was applied at 100, 200 and 300 W. The effect of drying conditions, i.e., microwave power, absolute pressure and FIR power, on drying characteristics and qualities of dried product were investigated. It was observed that an increase in microwave power and FIR power with a decrease in absolute pressure could accelerate the drying rate. It was also found that FIR-MVD method required shorter drying time than MVD. Moreover, qualities, i.e., color changes, texture, rehydration ability and shrinkage, of FIR-MVD chilli were found to be better than those of MVD. Consequently, the optimum drying condition of FIR-MVD within this study was microwave power of 300 W under absolute pressure of 21.33 kPa with FIR power of 300 W.

  2. An innovative intermittent-vacuum assisted thermophilic anaerobic digestion process for effective animal manure utilization and treatment. (United States)

    Zhang, Renchuan; Anderson, Erik; Addy, Min; Deng, Xiangyuan; Kabir, Fayal; Lu, Qian; Ma, Yiwei; Cheng, Yanling; Liu, Yuhuan; Chen, Paul; Ruan, Roger


    Intermittent-vacuum stripping (IVS) was developed as a pretreatment for thermophilic anaerobic digestion (TAD) to improve methanogenesis and hydrolysis activity through preventing free ammonia and hydrogen sulfide (H2S) inhibition from liquid swine manure (LSM). Over 98% of ammonia and 38% organic nitrogen were removed in 60min from 55°C to 85°C with vacuum pressure (from 100.63±3.79mmHg to 360.91±7.39mmHg) at initial pH 10.0 by IVS. Thermophilic methanogenesis and hydrolysis activity of pretreated LSM increased 52.25% (from 11.56±1.75% to 17.60±0.49%) in 25days and 40% (from 10days to 6days) in bio-methane potential assay. Over 80% H2S and total nitrogen were removed by IVS assistance, while around 70% nitrogen was recycled as ammonium sulfate. Therefore, IVS-TAD combination could be an effective strategy to improve TAD efficiency, whose elution is more easily utilized in algae cultivation and/or hydroponic system. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Test of the beam effect on vacuum arc occurrence in a high-gradient accelerating structure for the CLIC project

    CERN Document Server

    AUTHOR|(CDS)2130409; Gagliardi, Martino

    A new generation of lepton colliders capable of reaching TeV energies is pres- ently under development, and to succeed in this task it is necessary to show that the technology for such a machine is available. The Compact Linear Collider (CLIC) is a possible design option among the future lepton collider projects. It consists of two normal-conducting linacs. Accelerating structures with a gradient of the order of 100 MV/m are necessary to reach the required high energies within a reasonable machine length. One of the strictest require- ments for such accelerating structures is a relatively low occurrence of vacuum arcs. CLIC prototype structures have been tested in the past, but only in absence of beam. In order to proof the feasibility of the high gradient technology for building a functional collider, it is necessary to understand the effect of the beam presence on the vacuum breakdowns. Tests of this type have never been performed previously. The main goal of this work is to provide a first measurement of t...

  4. Effects of imperfect elements on resolution and sensitivity of quantum metrology using two-mode squeezed vacuum state. (United States)

    Zhang, Jiandong; Zhang, Zijing; Cen, Longzhu; Yu, Miao; Li, Shuo; Wang, Feng; Zhao, Yuan


    It has been demonstrated that using two-mode squeezed vacuum state for phase estimation can break the Heisenberg limit. Our results reveal that the two-mode squeezed vacuum state is also applied to the optical rotation angle measurement. In our scheme, the resolution and sensitivity of the optical rotation angle signal are the same as the case of phase estimation. For the parameter estimation, phase or rotation angle, we discuss the influences of several imperfect factors on the resolution and sensitivity. First, the effect that the upper limit of photon-number resolving has on the maximum amount of available quantum Fisher information has been analyzed. Then, we have also studied the impacts of both the transmission efficiency in the transmission process and the detection efficiency on the detection results. Finally, conditions where all of the above imperfect elements are taken into account at the same time have also been explored. Additionally, other imperfect factors such as squeezing efficiency and dark counts are briefly discussed.

  5. Influence of drying conditions on the effective diffusivity and activation energy during convective air and vacuum drying of pumpkin

    Directory of Open Access Journals (Sweden)

    Liliana SEREMET (CECLU


    Full Text Available The main purpose of the work is to investigate the efficiency of convective air and vacuum processing on pumpkin drying kinetics. The pumpkin samples were of two different geometrical shapes (cylinder and cube and were dried in a laboratory scale hot air dryer using some specific parameters (constant air velocity of 1.0 m/s, three different temperatures 50, 60 and 70ºC suited to relative humidity (RH values of 9.8, 6.5, and 5.4% respectively. The vacuum drying was led at constant pressures of 5 kPa and accordance temperatures of 50, 60 and 70ºC. Moisture transfer from pumpkin slices was described by applying Fick’s diffusion model. Temperature dependence of the effective diffusivity was described by the Arrhenius-type equation. Cylindrical samples have a slightly better behaviour compared to cubic samples, due to the disposition of the tissues, and the mass and thermic transfer possibilities. Analysing the results of both drying methods, it was deduced that the most efficient method is convective air drying at 70ºC.

  6. Quantum Vacuum Structure and Cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Rafelski, Johann; Labun, Lance; Hadad, Yaron; /Arizona U. /Munich U.; Chen, Pisin; /Taiwan, Natl. Taiwan U. /KIPAC, Menlo Park /SLAC


    Contemporary physics faces three great riddles that lie at the intersection of quantum theory, particle physics and cosmology. They are: (1) The expansion of the universe is accelerating - an extra factor of two appears in the size; (2) Zero-point fluctuations do not gravitate - a matter of 120 orders of magnitude; and (3) The 'True' quantum vacuum state does not gravitate. The latter two are explicitly problems related to the interpretation and the physical role and relation of the quantum vacuum with and in general relativity. Their resolution may require a major advance in our formulation and understanding of a common unified approach to quantum physics and gravity. To achieve this goal we must develop an experimental basis and much of the discussion we present is devoted to this task. In the following, we examine the observations and the theory contributing to the current framework comprising these riddles. We consider an interpretation of the first riddle within the context of the universe's quantum vacuum state, and propose an experimental concept to probe the vacuum state of the universe.

  7. Estimating teat canal cross-sectional area to determine the effects of teat-end and mouthpiece chamber vacuum on teat congestion. (United States)

    Penry, J F; Upton, J; Mein, G A; Rasmussen, M D; Ohnstad, I; Thompson, P D; Reinemann, D J


    The primary objective of this experiment was to assess the effect of mouthpiece chamber vacuum on teat-end congestion. The secondary objective was to assess the interactive effects of mouthpiece chamber vacuum with teat-end vacuum and pulsation setting on teat-end congestion. The influence of system vacuum, pulsation settings, mouthpiece chamber vacuum, and teat-end vacuum on teat-end congestion were tested in a 2×2 factorial design. The low-risk conditions for teat-end congestion (TEL) were 40 kPa system vacuum (Vs) and 400-ms pulsation b-phase. The high-risk conditions for teat-end congestion (TEH) were 49 kPa Vs and 700-ms b-phase. The low-risk condition for teat-barrel congestion (TBL) was created by venting the liner mouthpiece chamber to atmosphere. In the high-risk condition for teat-barrel congestion (TBH) the mouthpiece chamber was connected to short milk tube vacuum. Eight cows (32 quarters) were used in the experiment conducted during 0400 h milkings. All cows received all treatments over the entire experimental period. Teatcups were removed after 150 s for all treatments to standardize the exposure period. Calculated teat canal cross-sectional area (CA) was used to assess congestion of teat tissue. The main effect of the teat-end treatment was a reduction in CA of 9.9% between TEL and TEH conditions, for both levels of teat-barrel congestion risk. The main effect of the teat-barrel treatment was remarkably similar, with a decrease of 9.7% in CA between TBL and TBH conditions for both levels of teat-end congestion risk. No interaction between treatments was detected, hence the main effects are additive. The most aggressive of the 4 treatment combinations (TEH plus TBH) had a CA estimate 20% smaller than for the most gentle treatment combination (TEL plus TBL). The conditions designed to impair circulation in the teat barrel also had a deleterious effect on circulation at the teat end. This experiment highlights the importance of elevated mouthpiece

  8. Fluctuations of cytoskeleton-bound microbeads-the effect of bead-receptor binding dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Metzner, C; Raupach, C; Mierke, C T; Fabry, B, E-mail: bfabry@biomed.uni-erlangen.d [Center for Medical Physics and Technology, University of Erlangen-Nuremberg, Erlangen (Germany)


    The cytoskeleton (CSK) of living cells is a crosslinked fiber network, subject to ongoing biochemical remodeling processes that can be visualized by tracking the spontaneous motion of CSK-bound microbeads. The bead motion is characterized by anomalous diffusion with a power-law time evolution of the mean square displacement (MSD), and can be described as a stochastic transport process with apparent diffusivity D and power-law exponent {beta}: MSD {approx} D (t/t{sub 0}){sup {beta}}. Here we studied whether D and {beta} change with the time that has passed after the initial bead-cell contact, and whether they are sensitive to bead coating (fibronectin, integrin antibodies, poly-L-lysine, albumin) and bead size (0.5-4.5 {mu}m). The measurements are interpreted in the framework of a simple model that describes the bead as an overdamped particle coupled to the fluctuating CSK network by an elastic spring. The viscous damping coefficient characterizes the degree of bead internalization into the cell, and the spring constant characterizes the strength of the binding of the bead to the CSK. The model predicts distinctive signatures of the MSD that change with time as the bead couples more tightly to the CSK and becomes internalized. Experimental data show that the transition from the unbound to the tightly bound state occurs in an all-or-nothing manner. The time point of this transition shows considerable variability between individual cells (2-30 min) and depends on the bead size and bead coating. On average, this transition occurs later for smaller beads and beads coated with ligands that trigger the formation of adhesion complexes (fibronectin, integrin antibodies). Once the bead is linked to the CSK, however, the ligand type and bead size have little effect on the MSD. On longer timescales of several hours after bead addition, smaller beads are internalized into the cell more readily, leading to characteristic changes in the MSD that are consistent with increased

  9. Transport and fluctuations in granular fluids from Boltzmann equation to hydrodynamics, diffusion and motor effects

    CERN Document Server

    Puglisi, Andrea


    This brief offers a concise presentation of granular fluids from the  point of view of non-equilibrium statistical physics. The emphasis is on fluctuations, which can be large in granular fluids due to the small system size (the number of grains is many orders of magnitude smaller than in molecular fluids). Firstly, readers will be introduced to the most intriguing experiments on fluidized granular fluids. Then granular fluid theory, which goes through increasing levels of coarse-graining and emerging collective phenomena, is described. Problems and questions are initially posed at the level of kinetic theory, which describes particle densities in full or reduced phase-space. Some answers become clear through hydrodynamics, which describes the evolution of slowly evolving fields. Granular fluctuating hydrodynamics, which builds a bridge to the most recent results in non-equilibrium statistical mechanics, is also introduced. Further and more interesting answers come when the dynamics of a massive intruder are...

  10. Fluctuation mechanisms in superconductors nanowire single-photon counters, enabled by effective top-down manufacturing

    CERN Document Server

    Bartolf, Holger


    Holger Bartolf discusses state-of-the-art detection concepts based on superconducting nanotechnology as well as sophisticated analytical formulæ that model dissipative fluctuation-phenomena in superconducting nanowire single-photon detectors. Such knowledge is desirable for the development of advanced devices which are designed to possess an intrinsic robustness against vortex-fluctuations and it provides the perspective for honorable fundamental science in condensed matter physics. Especially the nanowire detector allows for ultra-low noise detection of signals with single-photon sensitivity and GHz repetition rates. Such devices have a huge potential for future technological impact and might enable unique applications (e.g. high rate interplanetary deep-space data links from Mars to Earth). Contents Superconducting Single-Photon Detectors Nanotechnological Manufacturing; Scale: 10 Nanometer Berezinskii-Kosterlitz Thouless (BKT) Transition, Edge-Barrier, Phase Slips Target Groups Researchers and students of...

  11. The critical Casimir force in the superfluid phase: effect of fluctuations

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Shyamal [Department of Physics, University of Calcutta, 92 Acharya Prafulla Chandra Road, Kolkata-700 009 (India); Bhattacharjee, J K [SN Bose National Centre for Basic Sciences, Sector 3, JD Block, Salt Lake, Kolkata-700 098 (India); Samanta, Himadri S [Department of Physics and Astronomy, University of Sheffield, Hounsfield Road, Sheffield S3 7RH (United Kingdom); Bhattacharyya, Saugata [Department of Physics, Vidyasagar College, 39 Sankar Ghosh Lane, Kolkata-700 006 (India); Hu, Bambi, E-mail: [Centre for Nonlinear Studies, and BHKS Joint Centre for Nonlinear and Complex Systems, Hong Kong Baptist University, Kowloon Tong (Hong Kong)


    We have considered the critical Casimir force on a {sup 4}He film below and above the bulk {lambda} point. We have explored the role of fluctuations around the mean field theory in a perturbative manner, and have substantially improved the mean field result of Zandi et al (2007 Phys. Rev. E 76 030601(R)). The Casimir scaling function obtained by us approaches a universal constant (-{zeta}(3)/8{pi}) for T{approx}<2.13 K.

  12. Kinetic field theory: effects of momentum correlations on the cosmic density-fluctuation power spectrum (United States)

    Bartelmann, Matthias; Fabis, Felix; Kozlikin, Elena; Lilow, Robert; Dombrowski, Johannes; Mildenberger, Julius


    In earlier work, we have developed a kinetic field theory (KFT) for cosmological structure formation and showed that the nonlinear density-fluctuation power spectrum known from numerical simulations can be reproduced quite well even if particle interactions are taken into account to first order only. Besides approximating gravitational interactions, we had to truncate the initial correlation hierarchy of particle momenta at the second order. Here, we substantially simplify KFT. We show that its central object, the free generating functional, can be factorised, taking the full hierarchy of momentum correlations into account. The factors appearing in the generating functional, which we identify as nonlinearly evolved density-fluctuation power spectra, have a universal form and can thus be tabulated for fast access in perturbation schemes. In this paper, we focus on a complete evaluation of the free generating functional of KFT, not including particle interactions yet. This implies that the nonlinearly evolved power spectra contain a damping term which reflects that structures are being wiped out at late times by free streaming. Once particle interactions will be taken into account, they will compensate this damping. If we suppress this damping in a way suggested by the fluctuation-dissipation relations of KFT, our results show that the complete hierarchy of initial momentum correlations is responsible for a large part of the characteristic nonlinear deformation and the mode transport in the density-fluctuation power spectrum. Without any adjustable parameters, KFT accurately reproduces the scale at which nonlinear evolution sets in. Finally, we further develop perturbation theory based on the factorisation of the generating functional and propose a diagrammatic scheme for the perturbation terms.

  13. Research on the Dividend Policy of Listed Company and Fluctuation Effect of Stock Market

    Directory of Open Access Journals (Sweden)

    Wang Hua


    Full Text Available Based on the dividend policy and theory, this article takes the events that A stock of all the listed banking companies (16 in total issued dividend in the CSI stock market for 5 years from 2008 to 2012 as the investigation samples to inspect the relevance of dividend policy with the fluctuation of stock price and transaction volume, thus to prove the dividend policy is an efficient mechanism for information transmission.

  14. Preservation Effect of Two-Stage Cinnamon Bark (Cinnamomum Burmanii) Oleoresin Microcapsules On Vacuum-Packed Ground Beef During Refrigerated Storage (United States)

    Irfiana, D.; Utami, R.; Khasanah, L. U.; Manuhara, G. J.


    The purpose of this study was to determine the effect of two stage cinnamon bark oleoresin microcapsules (0%, 0.5% and 1%) on the TPC (Total Plate Count), TBA (thiobarbituric acid), pH, and RGB color (Red, Green, and Blue) of vacuum-packed ground beef during refrigerated storage (at 0, 4, 8, 12, and 16 days). This study showed that the addition of two stage cinnamon bark oleoresin microcapsules affected the quality of vacuum-packed ground beef during 16 days of refrigerated storage. The results showed that the TPC value of the vacuum-packed ground beef sample with the addition 0.5% and 1% microcapsules was lower than the value of control sample. The TPC value of the control sample, sample with additional 0.5% and 1% microcapsules were 5.94; 5.46; and 5.16 log CFU/g respectively. The TBA value of vacuum-packed ground beef were 0.055; 0.041; and 0.044 mg malonaldehyde/kg, resepectively on the 16th day of storage. The addition of two-stage cinnamon bark oleoresin microcapsules could inhibit the growth of microbia and decrease the oxidation process of vacuum-packed ground beef. Moreover, the change of vacuum-packed ground beef pH and RGB color with the addition 0.5% and 1% microcapsules were less than those of the control sample. The addition of 1% microcapsules showed the best effect in preserving the vacuum-packed ground beef.

  15. Monitoring the effectiveness of the vacuum bell during pectus excavatum treatment: Technical innovation. (United States)

    Sesia, Sergio B; Hradetzky, David; Haecker, Frank-Martin


    The vacuum bell (VB) is a valid and the only non-invasive treatment for pectus excavatum (PE). To elevate the sternum the patient himself creates a differential negative pressure inside the VB using a hand pump. A distance and differential pressure measuring device (DPMD) enables us for the first time to assess objectively those parameters. After approval by the institutional review board, 53 patients recruited from our outpatient clinic were included in this retrospective study and distributed into three groups (group 1 aged 6 to 10years; group 2 aged 11 to 15years; group 3 aged 16 to 20years). Sternum elevation and differential negative pressure inside the VB compared to atmospheric pressure were assessed with the DPMD, a device developed by engineers at the University of Applied Sciences, Northwestern Switzerland. Pressure-elevation curves were recorded during VB therapy. For statistical comparison of the groups, analysis of variance was used. Post-hoc analysis was performed using the Tukey-Kramer test. A p-value of less than 0.05 was considered to be statistically significant. The VB therapy was monitored in 53 children (39 males, 14 females) aged from 6 to 20years (average, 14years). Relationships were established between the differential negative pressure inside the vacuum bell, the elevation of the sternum, and the patient's age. The younger the patient, the lower is the differential negative pressure difference required to obtain a complete elevation of the sternum. Patient's age, weight, the pectus depth, the differential negative pressure inside the VB, and the elevation of the sternum were correlated. When comparing the depth 25 of the pectus excavatum to the patient's age, a statistically significant difference was verified between the groups 3 and 1 (p=0.0291) and 3 and 2 (p=0.0489). The older the patient, the deeper is the pectus excavatum. However, no statistically significant difference between the groups was found when comparing the sternum

  16. Baryon number fluctuations in chiral effective models and their phenomenological implications (United States)

    Almási, Gábor András; Friman, Bengt; Redlich, Krzysztof


    We study the critical properties of net-baryon-number fluctuations at the chiral restoration transition in a medium at finite temperature and net baryon density. The chiral dynamics of quantum chromodynamics (QCD) is modeled by the Polyakov-loop extended quark-meson Lagrangian that includes the coupling of quarks to vector meson and temporal gauge fields. The functional renormalization group is employed to properly account for the O (4 ) criticality at the phase boundary. We focus on the properties and systematics of ratios of the net-baryon-number cumulants χBn, for 1 ≤n ≤6 , near the phase boundary. The results are presented in the context of the recent experimental data of the STAR Collaboration on fluctuations of the net proton number in heavy-ion collisions at RHIC. We show that the model results for the energy dependence of the cumulant ratios are in good overall agreement with the data, with one exception. At center-of-mass energies below 19.6 GeV, we find that the measured fourth-order cumulant deviates considerably from the model results, which incorporate the expected O (4 ) and Z (2 ) criticality. We assess the influence of model assumptions and in particular of repulsive vector-interactions, which are used to modify the location of the critical end point in the model, on the cumulants ratios. Finally, we discuss a possibility to test to what extent the fluctuations are affected by nonequilibrium dynamics by comparing certain ratios of cumulants.

  17. Fluctuating shells under pressure (United States)

    Paulose, Jayson; Vliegenthart, Gerard A.; Gompper, Gerhard; Nelson, David R.


    Thermal fluctuations strongly modify the large length-scale elastic behavior of cross-linked membranes, giving rise to scale-dependent elastic moduli. Whereas thermal effects in flat membranes are well understood, many natural and artificial microstructures are modeled as thin elastic shells. Shells are distinguished from flat membranes by their nonzero curvature, which provides a size-dependent coupling between the in-plane stretching modes and the out-of-plane undulations. In addition, a shell can support a pressure difference between its interior and its exterior. Little is known about the effect of thermal fluctuations on the elastic properties of shells. Here, we study the statistical mechanics of shape fluctuations in a pressurized spherical shell, using perturbation theory and Monte Carlo computer simulations, explicitly including the effects of curvature and an inward pressure. We predict novel properties of fluctuating thin shells under point indentations and pressure-induced deformations. The contribution due to thermal fluctuations increases with increasing ratio of shell radius to thickness and dominates the response when the product of this ratio and the thermal energy becomes large compared with the bending rigidity of the shell. Thermal effects are enhanced when a large uniform inward pressure acts on the shell and diverge as this pressure approaches the classical buckling transition of the shell. Our results are relevant for the elasticity and osmotic collapse of microcapsules. PMID:23150558

  18. Longitudinal analysis of the effect of academic failure tolerance on academic achievement fluctuation in medical school students. (United States)

    Chae, Su Jin; Kim, Miran; Chang, Ki Hong


    Academic failure tolerance (AFT) is one of the important psychological concepts in education, but its applications in medical education are rare. Thus, the purpose of this study was to investigate the effect of academic failure tolerance on academic achievement fluctuation among medical school students using a longitudinal research design. The subjects were 43 medical students who responded to the AFT test. This study analyzed the longitudinal data of achievement scores up to the 2nd academic year (2012-2013) among students who were divided into academic achievement improvement and decline groups. Comparing the improvement and decline groups' mean academic achievement fluctuation scores demonstrated that behavior and preferred task difficulty showed high scores whereas feeling scores were lower in the improvement group (pacademic failure, the students favored the more difficult subjects and were more assiduous in their studies. This will form an important basis for enhancing academic achievement among medical students.

  19. Do metric fluctuations affect the Higgs dynamics during inflation? (United States)

    Markkanen, Tommi; Nurmi, Sami; Rajantie, Arttu


    We show that the dynamics of the Higgs field during inflation is not affected by metric fluctuations if the Higgs is an energetically subdominant light spectator. For Standard Model parameters we find that couplings between Higgs and metric fluctuations are suppressed by Script O(10‑7). They are negligible compared to both pure Higgs terms in the effective potential and the unavoidable non-minimal Higgs coupling to background scalar curvature. The question of the electroweak vacuum instability during high energy scale inflation can therefore be studied consistently using the Jordan frame action in a Friedmann-Lemaître-Robertson-Walker metric, where the Higgs-curvature coupling enters as an effective mass contribution. Similar results apply for other light spectator scalar fields during inflation.

  20. Integrated Cooling-Vacuum-Assisted Non-Fractional 1540 nm Erbium:Glass Laser is Effective in Treating Acne Scars. (United States)

    Politi, Yael; Levi, Assi; Lapidoth, Moshe


    Acne scars are a common result of in ammatory acne, affecting many patients worldwide. Among which, atrophic scars are the most prevalent form, presenting as dermal depressions caused by inflammatory degeneration of dermal collagen. Mid-infrared laser skin interaction is characterized by its modest absorption in water and nite penetration to the mid-dermis. Since collagen is a desirable laser target, 1540-nm wavelength is amenable for collagen remodeling within the depressed area of atrophic scars. To evaluate the safety and efficacy of acne scars treatment using an integrated cooling-vacuum-assisted 1540 nm Erbium: Glass Laser. This interventional prospective study included 25 volunteers (10 men, 15 women) with post acne atrophic scars. Patients were treated with a mid-infrared non-fractional 1540 nm Er:Glass laser (Alma Lasers Ltd. Caesarea, Israel) with integrat- ed cooling- vacuum assisted technology. Acne scars were exposed to 3 stacked laser pulses (400-600 mJ/pulse, 4 mm spot size, frequency of 3 Hz). Patients underwent 3-6 treatment sessions with a 2-3 week interval and were followed-up 1 month and 3 months after the last treatment. Clinical photographs were taken by high resolution digital camera before and after treatment. Clinical evaluation was performed by two independent dermatologists and results were graded on a scale of 0 (exacerbation) to 4 (76%-100% improvement). Patients' and physicians' satisfaction were also recorded (on a 1-5 scale). Pain perception and adverse effects were evaluated as well. Almost all patients (24/25) demonstrated a moderate to significant improvement. Average improvement was 3.9 and 4.1 points on the quartile scale used for outcome assessment 1 and 3 months following the last session, respectively. Patient satisfaction rate was 4.2. Side effects were minimal and transient: erythema, mild transient vesicles, and mild pain or inconvenience. CONCLUSION Cooling-Vacuum-Assisted mid-infrared non-fractional Er:Glass 1540 nm laser

  1. The effect of excitation wavelength on plasma spectrum of metals in vacuum condition (United States)

    Hidayah, A. N.; Suliyanti, M. M.; Isnaeni


    Pure metals Aluminum (Al), Copper (Cu) and Brass (CuZn) have been detected using laser-induced plasma spectroscopy technique using nanosecond laser. A Q-switch pulsed Nd:YAG laser operating at infrared (1064 nm), visible (532 nm) and ultraviolet (355 nm) wavelengths have been used. The energy laser used was 12 mJ and the experiment was carried out in vacuum condition (5 Torr). The plasma generated by a focused Nd:YAG laser beam was detected by a spectrometer to identify trace elements quantitatively. The result of quantitative trace element of pure metals at three different wavelengths gave the different results. Al metal excited by 355 nm, 532 nm and 1064 nm wavelengths has 5, 2 and 13 Al emission peaks, respectively. Whereas the analysis of Cu showed 5, 7 and 6 emission peaks upon excitation by 355 nm, 532 nm and 1064 nm wavelengths, respectively. Finally, CuZn metal produced 7 Cu lines and 2 Zn lines upon excitation by 355 nm wavelength, 8 Cu lines and 1 Zn line when excited by 532 nm wavelength, and 8 Cu lines and 3 Zn lines when excited by 1064 nm wavelength.

  2. Investigation of sludge viscosity and its effects on the performance of a vacuum rotation membrane bioreactor. (United States)

    Komesli, Okan Tarik; Gökçay, Celal Ferdi


    Sludge characteristics of a full-scale vacuum rotation membrane (VRM) bioreactor having plate-type membranes with 0.038 microm nominal pore size and 540 m2 surface area were investigated. The VRM plant is composed of an aeration tank and a filtration chamber. The sludge floc size distribution, as determined microscopically, was mainly between 0 and 100 microm in the filter chamber with very little difference in size distribution between summer (20-25 degrees C) and winter (10-15 degrees C) seasons. Small floc size encountered in the filtration chamber was evident due to excessive shear administered by the rotation action and vigorous agitation by the scouring air. The mixed liquor suspended solids (MLSS) was variable between 5.23 and 14.10 g/L in the VRM tank and sludge behaved plastic. Viscosity ranged between 2.39 and 30 cP in the VRM tank in relation with MLSS concentration and temperature. Above 20 cP inter-plate spaces rapidly clogged leading to major clean-up.

  3. Vacuum-Assisted Abdominal Closure Is Safe and Effective: A Cohort Study in 74 Consecutive Patients. (United States)

    Jensen, R O; Buchbjerg, T; Simonsen, R M; Eckardt, R; Qvist, N


    Vacuum-assisted closure (VAC) has, in many instances, become the treatment of choice in patients with abdominal catastrophes. This study describes the use and outcome of ABThera KCI® VAC in the Region Southern Denmark covering a population of approximately 1.202 mill inhabitants. A prospective multicenter study including all patients treated with VAC during an eleven-month period. A total of 74 consecutive patients were included. Median age was 64.4 (9-89) years, 64% were men, and median body mass index was 25 (17-42). Duration of VAC treatment was median 4.5 (0-39) days with median 1 (0-16) dressing changes. Seventy per cent of the patients attended the intensive care unit. The 90-day mortality was 15%. A secondary closure of the fascia was obtained in 84% of the surviving patients. Only one patient developed an enteroatmospheric fistula. Patients with secondary closure were less likely to develop large hernias and had better self-evaluated physical health score (p closure when possible has yet to be proven in a randomized study.

  4. Casimir effects for classical and quantum liquids in slab geometry: A brief review

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Shyamal, E-mail: [School of Physics, University of Hyderabad, C.R. Rao Road, Gachibowli, Hyderabad-500046 (India)


    We analytically explore Casimir effects for confinement of classical and quantum fluctuations in slab (film) geometry (i) for classical (critical) fluctuations over {sup 4}He liquid around the λ point, and (ii) for quantum (phonon) fluctuations of Bogoliubov excitations over an interacting Bose-Einstein condensate. We also briefly review Casimir effects for confinement of quantum vacuum fluctuations confined to two plates of different geometries.

  5. Nonperturbative QED vacuum birefringence (United States)

    Denisov, V. I.; Dolgaya, E. E.; Sokolov, V. A.


    In this paper we represent nonperturbative calculation for one-loop Quantum Electrodynamics (QED) vacuum birefringence in presence of strong magnetic field. The dispersion relations for electromagnetic wave propagating in strong magnetic field point to retention of vacuum birefringence even in case when the field strength greatly exceeds Sauter-Schwinger limit. This gives a possibility to extend some predictions of perturbative QED such as electromagnetic waves delay in pulsars neighbourhood or wave polarization state changing (tested in PVLAS) to arbitrary magnetic field values. Such expansion is especially important in astrophysics because magnetic fields of some pulsars and magnetars greatly exceed quantum magnetic field limit, so the estimates of perturbative QED effects in this case require clarification.

  6. Short communication: Effects of vacuum freeze-drying on inactivation of Cronobacter sakazakii ATCC29544 in liquid media with different initial inoculum levels. (United States)

    Jiao, Rui; Gao, Jina; Zhang, Xiyan; Zhang, Maofeng; Chen, Jiren; Wu, Qingping; Zhang, Jumei; Ye, Yingwang


    Vacuum freeze-drying is an important food-processing technology for valid retention of nutrients and bioactive compounds. Cronobacter sakazakii has been reported to be associated with severe infections in neonates through consumption of contaminated powdered infant formula. In this study, effects of vacuum freeze-drying treatment for 12, 24, and 36 h on inactivation of C. sakazakii with different initial inoculum levels in sterile water, tryptic soy broth (TSB), skim milk, and whole milk were determined. Results indicated that the lethality rate of C. sakazakii in each sample increased with the extension of vacuum freeze-drying time. With initial inoculum levels of 102 and 103 cfu/mL, the survival of C. sakazakii in different liquid media was significantly affected by vacuum freeze-drying for 12, 24, and 36 h. In addition, the lethality rates of C. sakazakii in whole milk, skim milk, and TSB was significantly reduced compared with those in sterile water. Furthermore, whole milk showed the strongest protective role for C. sakazakii cells, followed by skim milk and TSB medium. Using the scanning electron microscope, the intracellular damage and obvious distortion of C. sakazakii cells were observed after vacuum freeze-drying for 24 and 36 h compared with the untreated sample, and the injured cells increased with the extension of vacuum-drying time. We concluded that inactivation of vacuum freeze-drying on C. sakazakii cells is related to the food matrix, and a combination with other methods for inactivating C. sakazakii is required for ensuring microbial safety of powdered infant formula. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  7. Effect of dietary vitamin E supplementation on the colour and lipid stability of fresh, frozen and vacuum-packaged beef. (United States)

    Lynch, M P; Kerry, J P; Buckley, D J; Faustman, C; Morrissey, P A


    The effects of dietary vitamin E supplementation on tissue α-tocopherol (α-Toc) levels and on the susceptibility of fresh, frozen and vacuum-packaged beef to lipid oxidation and colour deterioration were investigated. Friesian cattle were fed diets containing 20 (basal, n=5) or 2000 (supplemented, n=5) IU (α-tocopheryl acetate/kg feed/day for approximately 50 days prior to slaughter. α-Toc levels were higher (pM. longissimus dorsi (LD)>M. gluteus medius (GM) (pGM>LD (poxidative stability than meat from the basal group after 7 days retail display at 4°C (p<0.05). Thus, dietary (α-Toc supplementation appeared to retard metmyoglobin and TBARS formation in LD, GM and PM and increased the colour shelf life of these muscles.

  8. Effect of drying parameters on physiochemical and sensory properties of fruit powders processed by PGSS-, Vacuum- and Spray-drying. (United States)

    Feguš, Urban; Žigon, Uroš; Petermann, Marcus; Knez, Željko


    Aim of this experimental work was to investigate the possibility of producing fruit powders without employing drying aid and to investigate the effect of drying temperatures on the final powder characteristics. Raw fruit materials (banana puree, strawberry puree and blueberry concentrate) were processed using three different drying techniques each operating at a different temperature conditions: vacuum-drying (-27-17 °C), Spray-drying (130-160 °C) and PGSS-drying (112-152 °C). Moisture content, total colour difference, antioxidant activity and sensory characteristics of the processed fruit powders were analysed. The results obtained from the experimental work indicate that investigated fruit powders without or with minimal addition of maltodextrin can be produced. Additionally, it was observed that an increase in process temperature results in a higher loss of colour, antioxidant activity and intensity of the flavour profile.

  9. Effective use of nisin to control lactic acid bacterial spoilage in vacuum-packed bologna-type sausage. (United States)

    Davies, E A; Milne, C F; Bevis, H E; Potter, R W; Harris, J M; Williams, G C; Thomas, L V; Delves-Broughton, J


    Lactic acid bacteria (LAB) commonly cause spoilage in minimal heat-treated vacuum-packed cured delicatessen meats. Predominant species are Lactobacillus sake and L. curvatus. LAB strains isolated from spoiled products of this type (liver sausage, ham and bologna sausage) were found to be sensitive to low nisin concentrations (maximum of 1.25 microg g(-1)). Addition of 25 microg g(-1) nisin (as Nisaplin) inhibited the growth of LAB spoilage organisms inoculated into vacuum-packed pasteurized bologna-type sausages stored at 8 degrees C. Control sausages became spoiled (>10(8) LAB CFU g(-1)) by day 7, whereas sausages containing nisin remained unspoiled for >50 days. The effect of three types of phosphates (used as emulsifiers) on nisin activity in the sausages was compared. LAB growth rate was fastest in samples containing orthophosphate, and slowest in sausages containing diphosphate. The shelf life was also greatly extended in the latter. Fat content also affected nisin activity. Nisin activity (as indicated by LAB inhibition) was greatest in samples containing 15% > 25% > 37% (wt/wt) fat. In a sausage formulation containing 37% fat and incorporating diphosphate as emulsifier, levels of nisin as low as 2.5 microg g(-1) showed antibacterial effects. A nisin level of 6.25 microg g(-1) totally inhibited LAB growth for over 4 weeks and 25 microg g(-1) for 5 weeks. Spoilage control was achieved in the same sausage formulation but with 25% (wt/wt) fat; 12.5 microg g(-1) nisin prevented LAB growth for 5 weeks.

  10. Propagation of radio frequency waves through density fluctuations (United States)

    Valvis, S. I.; Papagiannis, P.; Papadopoulos, A.; Hizanidis, K.; Glytsis, E.; Bairaktaris, F.; Zisis, A.; Tigelis, I.; Ram, A. K.


    On their way to the core of a tokamak plasma, radio frequency (RF) waves, excited in the vacuum region, have to propagate through a variety of density fluctuations in the edge region. These fluctuations include coherent structures, like blobs that can be field aligned or not, as well as turbulent and filamentary structures. We have been studying the effect of fluctuations on RF propagation using both theoretical (analytical) and computational models. The theoretical results are being compared with those obtained by two different numerical codes ``a Finite Difference Frequency Domain code and the commercial COMSOL package. For plasmas with arbitrary distribution of coherent and turbulent fluctuations, we have formulated an effective dielectric permittivity of the edge plasma. This permittivity tensor is then used in numerical simulations to study the effect of multi-scale turbulence on RF waves. We not only consider plane waves but also Gaussian beams in the electron cyclotron and lower hybrid range of frequencies. The analytical theory and results from simulations on the propagation of RF waves will be presented. Supported in part by the Hellenic National Programme on Controlled Thermonuclear Fusion associated with the EUROfusion Consortium and by DoE Grant DE-FG02-91ER-54109.

  11. Mechanisms of current fluctuation in ambipolar black phosphorus field-effect transistors. (United States)

    Li, Xuefei; Du, Yuchen; Si, Mengwei; Yang, Lingming; Li, Sichao; Li, Tiaoyang; Xiong, Xiong; Ye, Peide; Wu, Yanqing


    Multi-layer black phosphorus has emerged as a strong candidate owing to its high carrier mobility with most of the previous research work focused on its p-type properties. Very few studies have been performed on its n-type electronic characteristics which are important not only for the complementary operation for logic, but also crucial for understanding the carrier transport through the metal-black phosphorus junction. A thorough understanding and proper evaluation of the performance potential of both p- and n-types are highly desirable. In this paper, we investigate the temperature dependent ambipolar operation of both electron and hole transport from 300 K to 20 K. On-currents as high as 85 μA μm(-1) for a 0.2 μm channel length BP nFET at 300 K are observed. Moreover, we provide the first systematic study on the low frequency noise mechanisms for both n-channel and p-channel BP transistors. The dominated noise mechanisms of the multi-layer BP nFET and pFET are mobility fluctuation and carrier number fluctuations with correlated mobility fluctuations, respectively. We have also established a baseline of the low electrical noise of 8.1 × 10(-9)μm(2) Hz(-1) at 10 Hz at room temperature for BP pFETs, which is 3 times improvement over previous reports, and 7.0 × 10(-8)μm(2) Hz(-1) for BP nFETs for the first time.

  12. [Endoscopic vacuum-assisted closure]. (United States)

    Wedemeyer, J; Lankisch, T


    Anastomotic leakage in the upper and lower intestinal tract is associated with high morbidity and mortality. Within the last 10 years endoscopic treatment options have been accepted as sufficient treatment option of these surgical complications. Endoscopic vacuum assisted closure (E-VAC) is a new innovative endoscopic therapeutic option in this field. E-VAC transfers the positive effects of vacuum assisted closure (VAC) on infected cutaneous wounds to infected cavities that can only be reached endoscopically. A sponge connected to a drainage tube is endoscopically placed in the leakage and a continuous vacuum is applied. Sponge and vacuum allow removal of infected fluids and promote granulation of the leakage. This results in clean wound grounds and finally allows wound closure. Meanwhile the method was also successfully used in the treatment of necrotic pancreatitis.


    Directory of Open Access Journals (Sweden)

    H. Sudardja


    Full Text Available The modeling of earth dam was carried out in a drainage and seepage tank to analyze the seepage resulting from water level fluctuation in the upstream of the dam. The dam models were made of the mixture of Mt. Merapi sand deposit with the soil of sandy-silt from Wonosari area. The variations of sand content in the mixture were 100%; 90% and 80% and the upstream slope inclinations were 1:1; 1:1.5 and 1:2. The result showed that the dams with more sandy-silt in the mixture have smaller seepage and the dams with steeper upstream slope have greater seepage. During rapid rising of water level, the dams with steeper upstream slope have a high rising rate of upstream water level and higher height of downstream slope failure. Moreover, during rapid drawdown, the dams with gentler upstream slope have a smaller rate of upstream drawdown and lower height of upstream slope failure. The dams with more sandy-silt in the mixture have a higher value of rising rate and drawdown of upstream water level but lower height of downstream and upstream slope failure. In the dam management, continuous monitoring of the seepage resulting from reservoir water level fluctuation is required to avoid dam failure. Keywords: Earth dam, rapid rising, rapid drawdown, seepage, slope failure.

  14. Solvent fluctuations and nuclear quantum effects modulate the molecular hyperpolarizability of water (United States)

    Liang, Chungwen; Tocci, Gabriele; Wilkins, David M.; Grisafi, Andrea; Roke, Sylvie; Ceriotti, Michele


    Second-harmonic scattering (SHS) experiments provide a unique approach to probe noncentrosymmetric environments in aqueous media, from bulk solutions to interfaces, living cells, and tissue. A central assumption made in analyzing SHS experiments is that each molecule scatters light according to a constant molecular hyperpolarizability tensor β(2 ). Here, we investigate the dependence of the molecular hyperpolarizability of water on its environment and internal geometric distortions, in order to test the hypothesis of constant β(2 ). We use quantum chemistry calculations of the hyperpolarizability of a molecule embedded in point-charge environments obtained from simulations of bulk water. We demonstrate that both the heterogeneity of the solvent configurations and the quantum mechanical fluctuations of the molecular geometry introduce large variations in the nonlinear optical response of water. This finding has the potential to change the way SHS experiments are interpreted: In particular, isotopic differences between H2O and D2O could explain recent SHS observations. Finally, we show that a machine-learning framework can predict accurately the fluctuations of the molecular hyperpolarizability. This model accounts for the microscopic inhomogeneity of the solvent and represents a step towards quantitative modeling of SHS experiments.

  15. Effect of electric fields and fluctuations on confinement in a bumpy torus

    Energy Technology Data Exchange (ETDEWEB)

    Hiroe, S.; Glowienka, J.C.; Hillis, D.L.; Wilgen, J.B.; Chen, G.L.; Cobble, J.A.; El-Nadi, A.M.; Goyer, J.R.; Solensten, L.; Casson, W.H.


    In order to understand the relationships between confinement and space potential (electric field) and between confinement and density fluctuations, plasma parameters in the ELMO Bumpy Torus Scale (EBT-S) have been measured systematically for a wide range of operating conditions. Present EBT plasma parameters do not show a strong dependence on the potential profile, but rather exhibit a correlation with the fluctuations. The plasma pressure profile is found to be consistent with the profile anticipated on the basis of the flute stability criterion for a marginally stable plasma. For a heating power of 100 kW, the stored energy density is found to be restricted to the range between 4.5 x 10/sup 13/ eV-cm/sup -3/ and 7 x 10/sup 13/ eV-cm/sup -3/. The lower limit remains constant regardless of heating power and pertains to plasmas lacking an equilibrium and/or stability. The upper limit increases with heating power and is found to result from the onset of instabilities. In between the two limits is a plasma that is in an equilibrium state and is marginally stable. Operational trajectories exist that take the EBT plasma from one limit to the other.

  16. Effects of fluctuations in the orientational order parameter in the cyanobiphenyl (nCB) homologous series (United States)

    Marinelli; Mercuri


    Photopyroelectric measurements of the anisotropy in the thermal conductivity Deltak vs temperature in the nCB (n=5,ellipsis,9) series are reported. The data have been used to deduce the behavior of the orientational order parameter Q close to the nematic-isotropic (N-I) and smectic A-nematic (A-N) phase transitions, respectively. It has been shown that near the N-I transition the data for 5CB and 6CB are consistent with the so-called "tricritical hypothesis," which predicts beta=0.25. This is not true for 7CB and 8CB in which the order parameter exhibits a behavior that could be caused by the presence of fluctuations that become increasingly important when the transition temperature is approached. A very simple model, which takes into account the contribution of fluctuations to the orientational order, has been developed close to the A-N transition and it has been shown that it is in good agreement with the experimental results. A semiquantitative explanation for the observed behavior in compounds with different nematic range has been also given.

  17. Effect of vacuum drying on protein-mannitol interactions: The physical state of mannitol and protein structure in the dried state


    Sharma, Vikas K.; Kalonia, Devendra S.


    The purpose of the present studies was to systematically investigate protein-mannitol interactions using vacuum drying, to obtain a better understanding of the effect of protein/mannitol wt/wt ratios on the physical state of mannitol and protein secondary structure in the dried state. Solutions containing β-lactoglobulin (βLg):mannitol (1∶1–1∶15 wt/wt) were vacuum dried at 5°C under 3000 mTorr of pressure. The physical state of mannitol was studied using x-ray powder physical state of mannito...

  18. The effect of the operation modes of a gas discharge low-pressure amalgam lamp on the intensity of generation of 185 nm UV vacuum radiation

    Energy Technology Data Exchange (ETDEWEB)

    Vasilyak, L. M., E-mail: [Russian Academy of Sciences, Joint Institute of High Temperatures (Russian Federation); Drozdov, L. A., E-mail:; Kostyuchenko, S. V.; Sokolov, D. V. [ZAO LIT (Russian Federation); Kudryavtsev, N. N.; Sobur, D. A., E-mail: [Moscow Institute for Physics and Technology (Russian Federation)


    The effect of the discharge current, mercury vapor pressure, and the inert gas pressure on the intensity and efficiency of the 185 nm line generation are considered. The spectra of the UV radiation (vacuum ultraviolet) transmission by protective coatings from the oxides of rare earth metals and aluminum are investigated.

  19. Electromagnetic dynamic response of HL-2M vacuum vessel under plasma disruption considering the electromagneto-mechanical coupling effect

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Hongwei; Yuan, Zhensheng; Li, Weixin; Pei, Cuixiang; Xie, Shejuan [State Key Laboratory for Strength and Vibration of Mechanical Structures, Shaanxi Engineering Research Center for NDT and Structural Integrity Evaluation, Xi’an Jiaotong University, Xi’an 710049 (China); Chen, Zhenmao, E-mail: [State Key Laboratory for Strength and Vibration of Mechanical Structures, Shaanxi Engineering Research Center for NDT and Structural Integrity Evaluation, Xi’an Jiaotong University, Xi’an 710049 (China); Pan, Yudong; Cai, Lijun; Li, Jiaxian [Southwestern Institute of Physics, Chengdu 610041 (China)


    Highlights: • A 1/5 numerical model is established and validated for HL-2M vacuum vessel. • The Lagrangian approach used for treating the EM-mechanical coupling problem is introduced. • The EM field and structural dynamic response of HL-2M VV during plasma disruptions are simulated by using the Lagrangian strategy. • The dynamic responses of the VV of HL-2M are compared to clarify the effect of the EM-mechanical coupling under the MD and VED conditions. • The results present a basis for the safe operation of the HL-2M VV device. - Abstract: During plasma disruptions (PDs), transient eddy currents are induced in the HL-2M vacuum vessel (VV) which is a D-shaped, double thin-wall structure. Under the circumstance of high magnetic field, the resulting electromagnetic (EM) forces during PDs are large and the dynamic response of related structures may be violent. In this complicated EM circumstance, the EM-mechanical coupling effect may also have a great influence on the dynamic response of VV structure. In this paper, the EM field and structural dynamic response of HL-2M VV during PDs are simulated by adopting a numerical code of the Lagrangian approach. The Lagrangian approach is on the basis of the Maxwell equations in the Lagrangian description, which treats the coupling behavior of magnetic damping effect without explicitly using the velocity term. This approach can be easily applied to actual structures by updating FEM meshes and reforming coefficient matrices before calculating EM field at each time step. In this work, the disruption plasma currents of operating conditions are simulated by using the DINA code and then the dynamic responses of displacements and stresses of the VV of HL-2M are obtained for both cases with and without considering the coupling effect. The numerical results show that stresses under the disruptions (MD and VDE) are not significant and the coupling effect does not significantly affect the peak dynamic response for the HL-2M

  20. Edge conduction in vacuum glazing

    Energy Technology Data Exchange (ETDEWEB)

    Simko, T.M.; Collins, R.E. [Sydney Univ., NSW (Australia). Dept. of Applied Physics; Beck, F.A.; Arasteh, D. [Lawrence Berkeley Lab., CA (United States)


    Vacuum glazing is a form of low-conductance double glazing using in internal vacuum between the two glass sheets to eliminate heat transport by gas conduction and convection. An array of small support pillars separates the sheets; fused solder glass forms the edge seal. Heat transfer through the glazing occurs by radiation across the vacuum gap, conduction through the support pillars, and conduction through the bonded edge seal. Edge conduction is problematic because it affects stresses in the edge region, leading to possible failure of the glazing; in addition, excessive heat transfer because of thermal bridging in the edge region can lower overall window thermal performance and decrease resistance to condensation. Infrared thermography was used to analyze the thermal performance of prototype vacuum glazings, and, for comparison, atmospheric pressure superwindows. Research focused on mitigating the edge effects of vacuum glazings through the use of insulating trim, recessed edges, and framing materials. Experimentally validated finite-element and finite-difference modeling tools were used for thermal analysis of prototype vacuum glazing units and complete windows. Experimental measurements of edge conduction using infrared imaging were found to be in good agreement with finite-element modeling results for a given set of conditions. Finite-element modeling validates an analytic model developed for edge conduction.

  1. Vacuum-assisted cesarean section

    Directory of Open Access Journals (Sweden)

    McQuivey RW


    Full Text Available Ross W McQuivey,1 Jon E Block2 1Clinical Innovations, Salt Lake City, UT, 2Independent consultant, San Francisco, CA, USA Abstract: There has been a dramatic rise in the frequency of cesarean sections, surpassing 30% of all deliveries in the US. This upsurge, coupled with a decreasing willingness to allow vaginal birth after cesarean section, has resulted in an expansion of the use of vacuum assistance to safely extract the fetal head. By avoiding the use of a delivering hand or forceps blade, the volume being delivered through the uterine incision can be decreased when the vacuum is used properly. Reducing uterine extensions with their associated complications (eg, excessive blood loss in difficult cases is also a theoretical advantage of vacuum delivery. Maternal discomfort related to excessive fundal pressure may also be lessened. To minimize the risk of neonatal morbidity, proper cup placement over the “flexion point” remains essential to maintain vacuum integrity and reduce the chance of inadvertent detachment and uterine extensions. Based on the published literature and pragmatic clinical experience, utilization of the vacuum device is a safe and effective technique to assist delivery during cesarean section. Keywords: cesarean section, vacuum, forceps, birth, delivery

  2. Effects of rf power on electron density and temperature, neutral temperature, and Te fluctuations in an inductively coupled plasma (United States)

    Camparo, James; Fathi, Gilda


    Atomic clocks that fly on global-navigation satellites such as global positioning system (GPS) and Galileo employ light from low-temperature, inductively coupled plasmas (ICPs) for atomic signal generation and detection (i.e., alkali/noble-gas rf-discharge lamps). In this application, the performance of the atomic clock and the capabilities of the navigation system depend sensitively on the stability of the ICP's optical emission. In order to better understand the mechanisms that might lead to instability in these rf-discharge lamps, and hence the satellite atomic clocks, we studied the optical emission from a Rb/Xe ICP as a function of the rf power driving the plasma. Surprisingly, we found that the electron density in the plasma was essentially independent of increases in rf power above its nominal value (i.e., "rf-power gain") and that the electron temperature was only a slowly varying function of rf-power gain. The primary effect of rf power was to increase the temperature of the neutrals in the plasma, which was manifested by an increase in Rb vapor density. Interestingly, we also found evidence for electron temperature fluctuations (i.e., fluctuations in the plasma's high-energy electron content). The variance of these fluctuations scaled inversely with the plasma's mean electron temperature and was consistent with a simple model that assumed that the total electron density in the discharge was independent of rf power. Taken as a whole, our results indicate that the electrons in alkali/noble-gas ICPs are little affected by slight changes in rf power and that the primary effect of such changes is to heat the plasma's neutral species.

  3. Effects of solar wind ultralow-frequency fluctuations on plasma sheet electron temperature: Regression analysis with support vector machine (United States)

    Wang, Chih-Ping; Kim, Hee-Jeong; Yue, Chao; Weygand, James M.; Hsu, Tung-Shin; Chu, Xiangning


    To investigate whether ultralow-frequency (ULF) fluctuations from 0.5 to 8.3 mHz in the solar wind and interplanetary magnetic field (IMF) can affect the plasma sheet electron temperature (Te) near geosynchronous distances, we use a support vector regression machine technique to decouple the effects from different solar wind parameters and their ULF fluctuation power. Te in this region varies from 0.1 to 10 keV with a median of 1.3 keV. We find that when the solar wind ULF power is weak, Te increases with increasing southward IMF Bz and solar wind speed, while it varies weakly with solar wind density. As the ULF power becomes stronger during weak IMF Bz ( 0) or northward IMF, Te becomes significantly enhanced, by a factor of up to 10. We also find that mesoscale disturbances in a time scale of a few to tens of minutes as indicated by AE during substorm expansion and recovery phases are more enhanced when the ULF power is stronger. The effect of ULF powers may be explained by stronger inward radial diffusion resulting from stronger mesoscale disturbances under higher ULF powers, which can bring high-energy plasma sheet electrons further toward geosynchronous distance. This effect of ULF powers is particularly important during weak southward IMF or northward IMF when convection electric drift is weak.

  4. Drying behaviour, effective diffusivity and energy of activation of olive leaves dried by microwave, vacuum and oven drying methods (United States)

    Elhussein, Elaf Abdelillah Ali; Şahin, Selin


    Drying is the crucial food processing for bioactive components from plant materials before strating extraction in addition to preservation of raw plant materials during storage period. Olive leaves were dried by various methods such as microwave drying (MD), oven drying (OD) and vacuum drying (VD) at several temperature values in the present study. Mathematical models allow to develop, design and control the processes. 14 emprical equations were used to estimate the drying behaviour and the time required for drying. Convenience of the models were evaluated according to the correlation coefficient (R 2 ), varience (S 2 ) and root mean square deviation (D RMS ). On the other hand, the effective diffusion coefficient and energy for activation were also calculated. Effects of the drying methods on the total phenolic (TPC), flavonoid (TFC) and oleuropein contents and free radical scavenging activity (FRSA) of the olive leaves were also investigated to take into considiration the quality of the dried product. MD has proved to be the fastest drying method having the highest effective diffusivity and the lowest activation energy with a more qualitive product.

  5. The effect of developmental temperature fluctuation on wing traits and stressed locomotor performance in Drosophila melanogaster, and its dependence on heterozygosity

    DEFF Research Database (Denmark)

    Kjaersgaard, Anders; Le, Nguyet; Demontis, Ditte


    Background: Natural environments fluctuate and all organisms experience some degree of environmental variance. Global climate models predict increasing environmental variance in the future. Yet we do not fully understand how environmental variation affects performance traits. Questions: Does...... temperature fluctuation during development affect adult size and wing shape in Drosophila melanogaster? If so, are the effects predictable? Do they depend on heterozygosity? Do fluctuations in developmental temperature affect adult physiological performance at high temperature? Methods: We tested the effect...... of one fluctuating (21 degrees C/29 degrees C) and several constant (21 degrees C, 23 degrees C, 25 degrees C, 27 degrees C, 29 degrees C) developmental temperature regimes on three wing morphometric traits (wing length, wing width, and wing shape) in an experiment using three inbred lines of D...

  6. Effect of opicapone on levodopa pharmacokinetics, catechol-O-methyltransferase activity and motor fluctuations in patients with Parkinson's disease. (United States)

    Ferreira, J J; Rocha, J-F; Falcão, A; Santos, A; Pinto, R; Nunes, T; Soares-da-Silva, P


    Opicapone (OPC) is a novel third generation catechol-O-methyltransferase (COMT) inhibitor that enhances levodopa availability. This study investigated the effects of OPC in comparison with placebo on levodopa pharmacokinetics, tolerability and safety, COMT activity and motor response to levodopa in Parkinson's disease (PD) patients with motor fluctuations. This was a randomized, multicentre, double-blind and placebo-controlled study in four parallel groups of PD patients treated with standard-release 100/25 mg levodopa/carbidopa or levodopa/benserazide and with motor fluctuations (wearing-OFF phenomenon). Subjects were sequentially assigned to be administered, once-daily, up to 28 days (maintenance phase), placebo (n = 10) or 5 (n = 10), 15 (n = 10) and 30 mg (n = 10) OPC. Two levodopa tests were performed, one at baseline and another following the maintenance phase. Subjects kept a diary to record motor fluctuations (ON/OFF periods) throughout the study. In relation to placebo, levodopa exposure (AUC0-6) increased 24.7%, 53.9% and 65.6% following 5, 15 and 30 mg OPC, respectively. Maximum COMT inhibition (Emax) ranged from 52% (5 mg OPC) to 80% (30 mg OPC). The study was not designed to detect any significant differences in motor performance, but the exploratory analysis performed shows improvement in various motor outcomes, including a dose-dependent change in absolute OFF time corresponding to a percentage decrease of 4.16% (P > 0.05), 29.55% (P > 0.05) and 32.71% (P < 0.05) with 5, 15 and 30 mg OPC, respectively. Treatments were generally well tolerated and safe. OPC is a promising new COMT inhibitor that significantly decreased COMT activity, increased systemic exposure to levodopa and improved motor response. © 2015 EAN.

  7. Effect of Modified Atmosphere Packaging and Vacuum Packaging on Quality Characteristics of Low Grade Beef during Cold Storage

    Directory of Open Access Journals (Sweden)

    S. J. Hur


    Full Text Available Many studies have been carried out with respect to packaging methods and temperature conditions of beef. However, the effects of packaging methods and temperature conditions on the quality characteristics have not been extensively studied in low-grade beef. Low-grade beef samples were divided into 3 groups (C: ziplock bag packaging, T1: vacuum packaging, and T2: modified atmosphere packaging (MAP, CO2/N2 = 3:7 and samples were stored at 4°C for 21 days. The water-holding capacity (WHC was significantly lower in T1 than in the other samples up to 14 days of storage. The thiobarbituric acid reactive substances and volatile basic nitrogen values were significantly lower in T1 and T2 than in C after 7 to 14 days of storage. The total bacterial counts were significantly lower in T1 and T2 than in C after 14 days of storage. In a sensory evaluation, tenderness and overall acceptability were significantly higher in T1 and T2 than in C at the end of the storage period (21 days. We propose that the MAP method can improve beef quality characteristics of low-grade beef during cold storage. However, the beneficial effects did not outweigh the cost increase to implement MAP.

  8. Effect of Modified Atmosphere Packaging and Vacuum Packaging on Quality Characteristics of Low Grade Beef during Cold Storage (United States)

    Hur, S. J.; Jin, S. K.; Park, J. H.; Jung, S. W.; Lyu, H. J.


    Many studies have been carried out with respect to packaging methods and temperature conditions of beef. However, the effects of packaging methods and temperature conditions on the quality characteristics have not been extensively studied in low-grade beef. Low-grade beef samples were divided into 3 groups (C: ziplock bag packaging, T1: vacuum packaging, and T2: modified atmosphere packaging (MAP), CO2/N2 = 3:7) and samples were stored at 4°C for 21 days. The water-holding capacity (WHC) was significantly lower in T1 than in the other samples up to 14 days of storage. The thiobarbituric acid reactive substances and volatile basic nitrogen values were significantly lower in T1 and T2 than in C after 7 to 14 days of storage. The total bacterial counts were significantly lower in T1 and T2 than in C after 14 days of storage. In a sensory evaluation, tenderness and overall acceptability were significantly higher in T1 and T2 than in C at the end of the storage period (21 days). We propose that the MAP method can improve beef quality characteristics of low-grade beef during cold storage. However, the beneficial effects did not outweigh the cost increase to implement MAP. PMID:25049769

  9. The effect of respiratory oscillations in heart rate on detrended fluctuation analysis (United States)

    Govindan, Rathinaswamy B.; Kota, Srinivas; Al-Shargabi, Tareq; Swisher, Christopher B.; du Plessis, Adre


    Characterization of heart rate using detrended fluctuation analysis (DFA) is impeded by respiratory oscillations. In particular, the short-term exponent measured from 15 to 30 beats is compromised in the DFA. We reconstruct respiratory signal from electrocardiograms and attenuate the respiratory oscillation in the heart rate using a frequency-dependent subtraction approach. We validate this method by applying it to an electrocardiogram signal simulated using a coupled differential equation with the respiratory oscillation modelled using a sine function. The exponent estimated using the proposed approach agreed with the exponent incorporated in the model within a narrow range. In contrast, the exponent obtained from the raw data deviated from the expected value. Furthermore, the exponents obtained for the raw heart rate are smaller than the exponents obtained for the respiration oscillation attenuated heart rate. We apply this approach to heart rate measured from 12 preterm infants that were being treated for prematurity related complications. As observed in the simulated data, we show that compared to the raw heart rate, the respiratory oscillation attenuated heart rate shows higher short-term exponent (p < 0.001).

  10. Integrated cooling-vacuum-assisted 1540-nm erbium:glass laser is effective in treating mild-to-moderate acne vulgaris. (United States)

    Politi, Y; Levi, A; Enk, C D; Lapidoth, M


    Acne treatment by a mid-infrared laser may be unsatisfactory due to deeply situated acne-affected sebaceous glands which serve as its target. Skin manipulation by vacuum and contact cooling may improve laser-skin interaction, reduce pain sensation, and increase overall safety and efficacy. To evaluate the safety and efficacy of acne treatment using an integrated cooling-vacuum-assisted 1540-nm erbium:glass laser, a prospective interventional study was conducted. It included 12 patients (seven men and five women) suffering from mild-to-moderate acne vulgaris. The device utilizes a mid-infrared 1540-nm laser (Alma Lasers Ltd. Caesarea, Israel), which is integrated with combined cooling-vacuum-assisted technology. An acne lesion is initially manipulated upon contact by a vacuum-cooling-assisted tip, followed by three to four stacked laser pulses (500-600 mJ, 4 mm spot size, and frequency of 2 Hz). Patients underwent four to six treatment sessions with a 2-week interval and were followed-up 1 and 3 months after the last treatment. Clinical photographs were taken by high-resolution digital camera before and after treatment. Clinical evaluation was performed by two independent dermatologists, and results were graded on a scale of 0 (exacerbation) to 4 (76-100 % improvement). Patients' and physicians' satisfaction was also recorded. Pain perception and adverse effects were evaluated as well. All patients demonstrated a moderate to significant improvement (average score of 3.6 and 2.0 within 1 and 3 months, respectively, following last treatment session). No side effects, besides a transient erythema, were observed. Cooling-vacuum-assisted 1540-nm laser is safe and effective for the treatment of acne vulgaris.

  11. Quantum vacuum noise in physics and cosmology. (United States)

    Davies, P. C. W.


    The concept of the vacuum in quantum field theory is a subtle one. Vacuum states have a rich and complex set of properties that produce distinctive, though usually exceedingly small, physical effects. Quantum vacuum noise is familiar in optical and electronic devices, but in this paper I wish to consider extending the discussion to systems in which gravitation, or large accelerations, are important. This leads to the prediction of vacuum friction: The quantum vacuum can act in a manner reminiscent of a viscous fluid. One result is that rapidly changing gravitational fields can create particles from the vacuum, and in turn the backreaction on the gravitational dynamics operates like a damping force. I consider such effects in early universe cosmology and the theory of quantum black holes, including the possibility that the large-scale structure of the universe might be produced by quantum vacuum noise in an early inflationary phase. I also discuss the curious phenomenon that an observer who accelerates through a quantum vacuum perceives a bath of thermal radiation closely analogous to Hawking radiation from black holes, even though an inertial observer registers no particles. The effects predicted raise very deep and unresolved issues about the nature of quantum particles, the role of the observer, and the relationship between the quantum vacuum and the concepts of information and entropy. (c) 2001 American Institute of Physics.

  12. Nanoscale Vacuum Channel Transistor. (United States)

    Han, Jin-Woo; Moon, Dong-Il; Meyyappan, M


    Vacuum tubes that sparked the electronics era had given way to semiconductor transistors. Despite their faster operation and better immunity to noise and radiation compared to the transistors, the vacuum device technology became extinct due to the high power consumption, integration difficulties, and short lifetime of the vacuum tubes. We combine the best of vacuum tubes and modern silicon nanofabrication technology here. The surround gate nanoscale vacuum channel transistor consists of sharp source and drain electrodes separated by sub-50 nm vacuum channel with a source to gate distance of 10 nm. This transistor performs at a low voltage (3 microamperes). The nanoscale vacuum channel transistor can be a possible alternative to semiconductor transistors beyond Moore's law.

  13. Effects of vacuum or modified atmosphere packaging in combination with irradiation for control of Escherichia coli O157:H7 in ground beef patties. (United States)

    Kudra, Li L; Sebranek, Joseph G; Dickson, James S; Mendonca, Aubrey F; Larson, Elaine M; Jackson-Davis, Armitra L; Lu, Zheng


    The efficacy of controlling Escherichia coli O157:H7 in ground beef patties by combining irradiation with vacuum packaging or modified atmosphere packaging (MAP) was investigated. Fresh ground beef patties were inoculated with a five-strain cocktail of E. coli O157:H7 at 5 log CFU/g. Single patties, packaged with vacuum or high-CO(2) MAP (99.6% CO(2) plus 0.4% CO), were irradiated at 0 (control), 0.5, 1.0, or 1.5 kGy. The D(10)-value for this pathogen was 0.47 ± 0.02 kGy in vacuum and 0.50 ± 0.02 kGy in MAP packaging. Irradiation with 1.5 kGy reduced E. coli O157:H7 by 3.0 to 3.3 log, while 0.5 and 1.0 kGy achieved reductions of 0.7 to 1.0, and 2.0 to 2.2 log, respectively. After irradiation, the numbers of survivors of this pathogen on beef patties in refrigerated storage (4°C) did not change significantly for 6 weeks. Temperature abuse (at 25°C) resulted in growth in vacuum-packaged patties treated with 0.5 and 1.5 kGy, but no growth in MAP packages. This study demonstrated that combining irradiation with MAP was similar in effectiveness to irradiation with vacuum packaging for control of E. coli O157:H7 in ground beef patties during refrigerated storage. However, high-CO(2) MAP appeared to be more effective after temperature abuse.

  14. An investigation of the effect of rapid slurry chilling on blown pack spoilage of vacuum-packaged beef primals. (United States)

    Reid, R; Fanning, S; Whyte, P; Kerry, J; Bolton, D


    The aim of this study was to investigate if rapid slurry chilling would retard or prevent blown pack spoilage (BPS) of vacuum-packaged beef primals. Beef primals were inoculated with Clostridium estertheticum subspp. estertheticum (DSMZ 8809), C. estertheticum subspp. laramenise (DSMZ 14864) and C. gasigenes (DSMZ 12272), and vacuum-packaged with and without heat shrinkage (90°C for 3 s). These packs were then subjected to immediate chilling in an ice slurry or using conventional blast chilling systems and stored at 2°C for up to 100 days. The onset and progress of BPS was monitored using the following scale; 0-no gas bubbles in drip; 1-gas bubbles in drip; 2-loss of vacuum; 3-'blown'; 4-presence of sufficient gas inside the packs to produce pack distension and 5-tightly stretched, 'overblown' packs/packs leaking. Rapid slurry chilling (as compared to conventional chilling) did not significantly affect (P > 0.05) the time to the onset or progress of BPS. It was therefore concluded that rapid chilling of vacuum-packaged beef primals, using an ice slurry system, may not be used as a control intervention to prevent or retard blown pack spoilage. This study adds to our growing understanding of blown pack spoilage of vacuum-packaged beef primals and suggests that rapid chilling of vacuum-packaged beef primals is not a control option for the beef industry. The results suggest that neither eliminating the heat shrinkage step nor rapid chilling of vacuum-packaged beef retard the time to blown pack spoilage. © 2016 The Society for Applied Microbiology.

  15. Effects of vacuum-ultraviolet irradiation on copper penetration into low-k dielectrics under bias-temperature stress

    Energy Technology Data Exchange (ETDEWEB)

    Guo, X.; Zheng, H.; Xue, P.; Shohet, J. L. [Plasma Processing and Technology Laboratory and Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); King, S. W. [Logic Technology Development, Intel Corporation, Hillsboro, Oregon 97124 (United States); Nishi, Y. [Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States)


    The effects of vacuum-ultraviolet (VUV) irradiation on copper penetration into non-porous low-k dielectrics under bias-temperature stress (BTS) were investigated. By employing x-ray photoelectron spectroscopy depth-profile measurements on both as-deposited and VUV-irradiated SiCOH/Cu stacks, it was found that under the same BTS conditions, the diffusion depth of Cu into the VUV-irradiated SiCOH is higher than that of as-deposited SiCOH. On the other hand, under the same temperature-annealing stress (TS) without electric bias, the Cu distribution profiles in the VUV-irradiated SiCOH were same with that for the as-deposited SiCOH. The experiments suggest that in as-deposited SiCOH, the diffused Cu exists primarily in the atomic state, while in VUV-irradiated SiCOH, the diffused Cu is oxidized by the hydroxyl ions (OH{sup −}) generated from VUV irradiation and exists in the ionic state. The mechanisms for metal diffusion and ion injection in VUV irradiated low-k dielectrics are discussed.

  16. The Effect of Vacuum-Assisted Closure on the Bacterial Load and Type of Bacteria: A Systematic Review (United States)

    Patmo, Aryan S.P.; Krijnen, Pieta; Tuinebreijer, Wim E.; Breederveld, Roelf S.


    Significance: A high bacterial load interferes with the healing process of a wound. Vacuum-assisted closure (VAC) is a wound healing therapy that utilizes a dressing system that continuously or intermittently applies a negative pressure to the wound surface. Recent Advances: VAC stimulates wound healing, but data on changes in the bacterial load and changes in the bacterial spectrum are scarce. Critical Issues: While VAC supposedly removes bacteria from the treated wounds and therefore reduces the risk of infection, this relationship has not yet been clinically proven. If VAC increases the bacterial load instead of decreasing it, then this may be a reason not to use VAC on certain types of wounds. Only seven small and heterogeneous studies reporting on the relationship between VAC usage and the bacterial load and type of bacteria in the treated wounds in clinical practice were found in the literature. Although there is some low quality evidence that VAC therapy does not change the bacterial load, no definite conclusions on changes in the bacterial load and type of bacteria during VAC can be drawn. Future Directions: Prospectively monitoring changes in the bacterial load and bacterial spectrum in patients that will receive VAC treatment on indication might be an effective way to find out whether it should indeed be used on specific wounds. PMID:24804158

  17. Effects of pH on photochemical decomposition of perfluorooctanoic acid in different atmospheres by 185nm vacuum ultraviolet. (United States)

    Wang, Yuan; Zhang, Pengyi


    Perfluorooctanoic acid (PFOA), a persistent organic pollutant, receives increasing concerns due to its worldwide occurrence and resistance to most conventional treatment processes. The photochemical decomposition by 185nm vacuum ultraviolet (VUV) is one of the efficient methods for PFOA decomposition. The effects of pH on PFOA decomposition in nitrogen atmosphere or oxygen atmosphere were investigated. At its original pH (4.5) of PFOA aqueous solution, PFOA decomposed efficiently both in nitrogen and in oxygen atmosphere. However, when the pH increased to 12.0, PFOA decomposition was greatly inhibited in oxygen atmosphere, while it was greatly accelerated in nitrogen atmosphere with a very short half-life time (9min). Furthermore, fluorine atoms originally contained in PFOA molecules were almost completely transformed into fluoride ions. Two decomposition pathways have been proposed to explain the PFOA decomposition under different conditions. In acidic and neutral solutions, PFOA predominantly decomposes via the direct photolysis in both atmospheres; while in the alkaline solution and in the absence of oxygen, the decomposition of PFOA is mainly induced by hydrated electrons. Copyright © 2014. Published by Elsevier B.V.

  18. (Quasi-)collisional Magneto-optic Effects in Collisionless Plasmas with sub-Larmor-scale Electromagnetic Fluctuations

    CERN Document Server

    Keenan, Brett D; Medvedev, Mikhail V


    High-amplitude, chaotic/turbulent electromagnetic fluctuations are ubiquitous in high-energy-density laboratory and astrophysical plasmas, where they can be excited by various kinetic-streaming and/or anisotropy-driven instabilities, such as the Weibel instability. These fields typically exist on "sub-Larmor scales" -- scales smaller than the electron Larmor radius. Electrons moving through such magnetic fields undergo small-angle stochastic deflections of their pitch-angles, thus establishing diffusive transport on long time-scales. We show that this behavior, under certain conditions, is equivalent to Coulomb collisions in collisional plasmas. The magnetic pitch-angle diffusion coefficient, which acts as an effective "collision" frequency, may be substantial in these, otherwise, collisionless environments. We show that this effect, colloquially referred to as the plasma "quasicollisionality", may radically alter the expected radiative transport properties of candidate plasmas. We argue that the modified mag...

  19. Effect of the interface recombination current fluctuations on 1/f noise of gated lateral bipolar transistors (United States)

    Romas, Gregory G., Jr.; Ul Hoque, Md Mazhar; Celik-Butler, Zeynep


    A gated lateral bipolar transistor is a bulk lateral BJT in parallel with a MOSFET at the surface. The base current components such as surface recombination and space charge recombination currents are two of the dominant noise sources in the lateral BJT. If the gate is biased such that the MOSFET is in the off-state by accumulating carriers underneath the oxide in the base surface, the noise contribution by these two base current (Ib) components can be better understood. The carrier accumulation in the base surface can be modulated with different gate bias, which in turn will affect the fluctuation of the surface recombination current component. In this paper, noise power spectral density of gated lateral PNP transistors, fabricated in Texas Instruments Standard Bipolar Process, has been discussed. The base current noise power spectral density (SIb) was extracted from the cross-correlation noise spectrum measured between the base and the collector circuits for different gate biasing conditions. Based on the frequency exponent dependence of the noise power spectral density, it was found that the noise in the low frequency range is in the form of 1/f noise. SIb was found to be the dominant noise source for these devices as the coherence between the base and collector power spectral density was very close to 1. SIb was extracted for a base current range of 8 nA to 1microA for a gate bias range of 0V to 40V. The SPICE noise model parameters, AF and KF were also determined for each case from the dependence of SIb on Ib. The noise was measured on devices with different base width values.

  20. Fluctuating Selection in the Moran. (United States)

    Dean, Antony M; Lehman, Clarence; Yi, Xiao


    Contrary to classical population genetics theory, experiments demonstrate that fluctuating selection can protect a haploid polymorphism in the absence of frequency dependent effects on fitness. Using forward simulations with the Moran model, we confirm our analytical results showing that a fluctuating selection regime, with a mean selection coefficient of zero, promotes polymorphism. We find that increases in heterozygosity over neutral expectations are especially pronounced when fluctuations are rapid, mutation is weak, the population size is large, and the variance in selection is big. Lowering the frequency of fluctuations makes selection more directional, and so heterozygosity declines. We also show that fluctuating selection raises dn /ds ratios for polymorphism, not only by sweeping selected alleles into the population, but also by purging the neutral variants of selected alleles as they undergo repeated bottlenecks. Our analysis shows that randomly fluctuating selection increases the rate of evolution by increasing the probability of fixation. The impact is especially noticeable when the selection is strong and mutation is weak. Simulations show the increase in the rate of evolution declines as the rate of new mutations entering the population increases, an effect attributable to clonal interference. Intriguingly, fluctuating selection increases the dn /ds ratios for divergence more than for polymorphism, a pattern commonly seen in comparative genomics. Our model, which extends the classical neutral model of molecular evolution by incorporating random fluctuations in selection, accommodates a wide variety of observations, both neutral and selected, with economy. Copyright © 2017 by the Genetics Society of America.

  1. Synthesis of DHA/EPA-rich phosphatidylcholine by immobilized phospholipase A1: effect of water addition and vacuum condition. (United States)

    Li, Daoming; Qin, Xiaoli; Wang, Weifei; Li, Zhigang; Yang, Bo; Wang, Yonghua


    DHA/EPA-rich phosphatidylcholine (PC) was successfully synthesized by immobilized phospholipase A1 (PLA1)-catalyzed transesterification of PC and DHA/EPA-rich ethyl esters in a solvent-free system. Effects of reaction temperature, water addition and substrate mass ratio on the incorporation of DHA/EPA were evaluated using response surface methods (RSM). Water addition had most significant effect on the incorporation. Reaction temperature and substrate mass ratio, however, had no significant effect on the incorporation. The maximal incorporation was 19.09 % (24 h) under the following conditions: temperature 55.7 °C, water addition 1.1 wt % and substrate mass ratio (ethyl esters/PC) 6.8:1. Furthermore, effects of water addition (from 0 to 1.25 wt %) on DHA/EPA incorporation and the composition of products were further investigated. The immobilized PLA1 was more active when water addition was above 0.5 wt %. By monitoring the reaction processes with different water addition, a possible reaction scheme was proposed for transesterification of PC with DHA/EPA-rich ethyl esters. In summary, PC and sn2-lysophosphatidylocholine (LPC) were predominant in the mixtures at early stages of reaction, whereas sn1-LPC and glycerophosphocholine (GPC) predominant at later stages. The vacuum employed after 24 h significantly increased the incorporation of DHA/EPA and the composition of PC, and the highest incorporation (30.31 %) of DHA/EPA was obtained at 72 h and the yield of PC was 47.2 %.

  2. Giant vacuum forces via transmission lines. (United States)

    Shahmoon, Ephraim; Mazets, Igor; Kurizki, Gershon


    Quantum electromagnetic fluctuations induce forces between neutral particles, known as the van der Waals and Casimir interactions. These fundamental forces, mediated by virtual photons from the vacuum, play an important role in basic physics and chemistry and in emerging technologies involving, e.g., microelectromechanical systems or quantum information processing. Here we show that these interactions can be enhanced by many orders of magnitude upon changing the character of the mediating vacuum modes. By considering two polarizable particles in the vicinity of any standard electric transmission line, along which photons can propagate in one dimension, we find a much stronger and longer-range interaction than in free space. This enhancement may have profound implications on many-particle and bulk systems and impact the quantum technologies mentioned above. The predicted giant vacuum force is estimated to be measurable in a coplanar waveguide line.

  3. Indian Vacuum Society: The Indian Vacuum Society (United States)

    Saha, T. K.


    The Indian Vacuum Society (IVS) was established in 1970. It has over 800 members including many from Industry and R & D Institutions spread throughout India. The society has an active chapter at Kolkata. The society was formed with the main aim to promote, encourage and develop the growth of Vacuum Science, Techniques and Applications in India. In order to achieve this aim it has conducted a number of short term courses at graduate and technician levels on vacuum science and technology on topics ranging from low vacuum to ultrahigh vacuum So far it has conducted 39 such courses at different parts of the country and imparted training to more than 1200 persons in the field. Some of these courses were in-plant training courses conducted on the premises of the establishment and designed to take care of the special needs of the establishment. IVS also regularly conducts national and international seminars and symposia on vacuum science and technology with special emphasis on some theme related to applications of vacuum. A large number of delegates from all over India take part in the deliberations of such seminars and symposia and present their work. IVS also arranges technical visits to different industries and research institutes. The society also helped in the UNESCO sponsored post-graduate level courses in vacuum science, technology and applications conducted by Mumbai University. The society has also designed a certificate and diploma course for graduate level students studying vacuum science and technology and has submitted a syllabus to the academic council of the University of Mumbai for their approval, we hope that some colleges affiliated to the university will start this course from the coming academic year. IVS extended its support in standardizing many of the vacuum instruments and played a vital role in helping to set up a Regional Testing Centre along with BARC. As part of the development of vacuum education, the society arranges the participation of

  4. Potentially Missing Physics of the Early Universe: Nonlinear Vacuum Polarization in Intense Blackbody Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, S Q; Hartemann, F V


    critical field. The basic process is the appearance of vacuum polarization, or the creation of the virtual electron-positron pair by vacuum fluctuations, as shown in Fig.1. These quantum processes can be described by an effective field theory for the electromagnetic field where the effects of virtual processes appear as small corrections. First derived by Heisenberg and Euler, this theory describes the corrections to classical electromagnetic theory due to photon-photon scattering [1]. An overview of nonlinear vacuum effects as formulated through the Heisenberg-Euler Lagrangian can be found in [2].

  5. Measurement of partial pressures in vacuum technology and vacuum physics (United States)

    Huber, W. K.


    It is pointed out that the measurement of gaseous pressures of less than 0.0001 torr is based on the ionization of gas atoms and molecules due to collisions with electrons. The particle density is determined in place of the pressure. The ionization cross sections for molecules of various gases are discussed. It is found that the true pressure in a vacuum system cannot be determined with certainty if it is unknown which gas is present. Effects of partial pressure determination on the condition of the vacuum system are discussed together with ion sources, systems of separation, and ion detection.

  6. Establishment of earth tides effect on water level fluctuations in an unconfined hard rock aquifer using spectral analysis

    CERN Document Server

    Maréchal, Jean-Christophe; Ahmed, Shakeel; Lachassagne, Patrick


    Short-interval water level measurements using automatic water level recorder in a deep well in an unconfined crystalline rock aquifer at the campus of NGRI, near Hyderabad shows a cyclic fluctuation in the water levels. The observed values clearly show the principal trend due to rainfall recharge. Spectral analysis was carried out to evaluate correlation of the cyclic fluctuation to the synthetic earth tides as well as groundwater withdrawal time series in the surrounding. It was found that these fluctuations have considerably high correlation with earth tides whereas groundwater pumping does not show any significant correlation with water table fluctuations. It is concluded that earth tides cause the fluctuation in the water table. These fluctuations were hitherto unobserved during manual observations made over larger time intervals. It indicates that the unconfined aquifer is characterised by a low porosity.

  7. Effect of nisin on biogenic amines and shelf life of vacuum packaged rainbow trout (Oncorhynchus mykiss) fillets. (United States)

    Chaves López, Clemencia; Serio, Annalisa; Montalvo, Costanza; Ramirez, Cristina; Peréz Álvarez, José Angel; Paparella, Antonello; Mastrocola, Dino; Martuscelli, Maria


    Nisin is a lantibiotic exhibiting antimicrobial activity against a wide range of Gram-positive bacteria, or some Gram-negative bacteria when used in combination with other preservative agents. The objective of the present work was to study the effect of nisin treatment on biogenic amines occurrence and shelf life of refrigerated (4 °C) vacuum packaged rainbow trout samples. For this purpose samples were divided in two batches: the experimental batch (CB-N), consisting of samples immersed in sterilized broth formulated with soy milk 1.4% (v/v) and whey powder 11.2% (w/v) dissolved in deionized water with addition of nisin (500 mg L -1 ); the control batch (CB), consisting of samples immersed in the former broth without addition of nisin. A positive effect of nisin resulted on colour stability; in fact, the global colour index ΔE remained constant during the storage of treated rainbow trout samples, while it increased in the control. However, the behaviour of microbiota, texture, odour and biogenic amines were comparable between fillet samples treated with nisin broth and with control medium (without nisin). No inhibitory effects of nisin on biogenic amines accumulation was observed; conversely, the decline of histamine content (about 30%), observed only in fishes of the control batch, may be correlated to the presence of histamine-degradating bacteria ( Pseudomonas species). Further studies are necessary to investigate nisin action mechanism on the colour, an important physical characteristic involved in the product quality and consumer acceptability.

  8. Quantum vacuum effects for a massive Bosonic string in background B-field

    Directory of Open Access Journals (Sweden)

    Y Koohsarian


    Full Text Available We study the Casimir effect for a Bosonic string extended between D-branes, and living in a flat space with an antisymmetric background B-field. We find the Casimir energy as a function of the B-field, and the mass-parameter of the string, and accordingly we obtain a B-dependence correction term to the ground-state mass of the string. We show that for sufficiently large B-field, the ground state of the string contains real (i.e. non-Tachyonic particles

  9. Effect of vacuum arc cathode spot distribution on breaking capacity of the arc-extinguishing chamber (United States)

    Ding, Can; Yuan, Zhao; He, Junjia


    A DC circuit breaker performs a key function in breaking an intermediate-frequency (IF) current since breaking a pure IF current is equivalent to breaking a very small DC with a reverse IF current. In this study, it is found that cathode spots show a ring-shaped distribution at 2000 Hz. An arc with an uneven distribution of cathode spots has been simulated. The simulation results show that the distribution of cathode spots significantly affect the microparameter distribution of arc plasma. The current distribution on the anode side differs from that on the cathode side under the total radial electric field. Specifically, the anode current distribution is both uneven and concentrated. The applied axial magnetic field, which cannot reduce the concentrated anode current distribution effectively, might increase the concentration of the anode current. Finally, the uneven distribution of cathode spots reduces the breaking capacity of the arc-extinguishing chamber.

  10. On the Use of GOES Thermal Data to Study Effects of Land Use on Diurnal Temperature Fluctuation. (United States)

    Shih, S. F.; Chen, E.


    Geostationary Operational Environmental Satellite (GOES) infrared data were used to study the effect of land use on the diurnal surface temperature fluctuation. Five major land use types in southern Florida: the sandy soil agricultural area; the Everglades Agricultural Area (EAA); the conservation areas; the Natural Everglades Area (NEA); and Lake Okeechobee; were observed. The average daytime and nocturnal surface temperatures of sandy soil in agricultural areas was lower than that of organic soil in agricultural areas. The average temperature of organic soil in agricultural areas was lower than that of organic soil in conservation areas. The surface temperature in the wet marsh area was much lower than that in a large water-storage lake. A land use change in the EAA, and an increase in the water storage in Lake Okeechobee and the conservation areas could influence the microclimate.

  11. Effect of Boundary Condition Fluctuations on Smoluchowski Reaction Rates: Dedicated to Lutz Schimansky-Geier, half a century wise (United States)

    Doering, Charles R.

    We formulate, solve, and examine an elementary model of gated absorption, where the reactivity of a sphere fluctuates in time, in the context of Smolukowski's diffusion- controlled rate processes. Interest in this problem was stimulated by some experiments on biomolecular rate processes in the 1970s. The model under discussion here was studied by a number of investigators in the 1980s and interest is renewed by the discovery of resonant activation in the 1990s. We find that the si mplest gated reaction process does not exhibit features characteristic of resonant activation, although some interesting nonequilibrium correlations may have a quantitative effect in some situations. We speculate on the possible appearance of resonant activation phenomena in related processes.

  12. Effect of spin fluctuations in magnetocaloric and magnetoresistance properties of Dy10Co20Si70 alloy (United States)

    Rashid, T. P.; Arun, K.; Curlik, Ivan; Ilkovic, Sergej; Reiffers, Marian; Dzubinska, Andrea; Nagalakshmi, R.


    Systematic investigations on the structure, magnetic, thermodynamic, magnetocaloric and magnetoresistance (MR) properties of the arc melted Dy10Co20Si70 alloy are presented. The Dy10Co20Si70 alloy crystallizes in tetragonal BaNiSn3-type DyCoSi3 (space group = I4mm; No. 107) as a major phase and CaF2-type CoSi2 (space group = Fm-3m; No. 225) and C-type Si (space group = Fd-3m; No. 227) as minor phases. The title compound exhibits multiple magnetic transitions having antiferromagnetic ordering at temperatures, viz., T1 = 10.8 K, T2 = 8.8 K and T3 = 3.3 K. The magnetic and thermodynamic studies confirm these magnetic anomalies in the compound. The large value of maximum magnetic entropy change, -ΔSMM a x = 16.4 and 26.6 J/kg K for the field change ΔH of 50 and 90 kOe, respectively, observed in the compound is associated with field induced magnetic transitions. Asymmetric broadening of the magnetic entropy change peaks above the ordering temperatures resulting in significant refrigerant capacities of 361 and 868 J/kg for ΔH = 50 and 90 kOe, respectively, in the compound is due to the spin fluctuation effect. The sign reversal in MR measurements is attributed to the field induced antiferromagnetic to ferromagnetic transition. A large positive MR (42% in 90 kOe) is observed at 2 K. The H2 dependence of both the magnetocaloric effect (MCE) and MR in the paramagnetic regime indicates the role of the applied magnetic field in suppressing the spin fluctuations. The large MCE and MR together with no thermal or magnetic hysteresis establish this new compound as an attractive multifunctional magnetic material.

  13. The vacuum disconnector

    Energy Technology Data Exchange (ETDEWEB)

    Schellekens, H.


    After showing the extended experience of Holec with vacuum disconnectors, the difficulties encountered in developing the type SVS vacuum bottle are indicated. The implications of demands imposed on price and dimensions are translated into design features. The function and the design of the getter is explained to show how Holec guarantees a 20 year approved vacuum in the bottle. Finally, the results of switching tests are mentioned to explain the reliability and capability of the new disconnector. 12 figs.

  14. Intrinsic measurement errors for the speed of light in vacuum (United States)

    Braun, Daniel; Schneiter, Fabienne; Fischer, Uwe R.


    The speed of light in vacuum, one of the most important and precisely measured natural constants, is fixed by convention to c=299 792 458 m s-1 . Advanced theories predict possible deviations from this universal value, or even quantum fluctuations of c. Combining arguments from quantum parameter estimation theory and classical general relativity, we here establish rigorously the existence of lower bounds on the uncertainty to which the speed of light in vacuum can be determined in a given region of space-time, subject to several reasonable restrictions. They provide a novel perspective on the experimental falsifiability of predictions for the quantum fluctuations of space-time.

  15. Quantum fluctuations from thermal fluctuations in Jacobson formalism

    Energy Technology Data Exchange (ETDEWEB)

    Faizal, Mir [University of British Columbia-Okanagan, Irving K. Barber School of Arts and Sciences, Kelowna, BC (Canada); University of Lethbridge, Department of Physics and Astronomy, Lethbridge, AB (Canada); Ashour, Amani; Alcheikh, Mohammad [Damascus University, Mathematics Department, Faculty of Science, Damascus (Syrian Arab Republic); Alasfar, Lina [Universite Clermont Auvergne, Laboratoire de Physique Corpusculaire de Clermont-Ferrand, Aubiere (France); Alsaleh, Salwa; Mahroussah, Ahmed [King Saud University, Department of Physics and Astronomy, Riyadh (Saudi Arabia)


    In the Jacobson formalism general relativity is obtained from thermodynamics. This is done by using the Bekenstein-Hawking entropy-area relation. However, as a black hole gets smaller, its temperature will increase. This will cause the thermal fluctuations to also increase, and these will in turn correct the Bekenstein-Hawking entropy-area relation. Furthermore, with the reduction in the size of the black hole, quantum effects will also start to dominate. Just as the general relativity can be obtained from thermodynamics in the Jacobson formalism, we propose that the quantum fluctuations to the geometry can be obtained from thermal fluctuations. (orig.)

  16. The effect of additives on migration and transformation of gaseous pollutants in the vacuum pyrolysis process of waste printed circuit boards. (United States)

    Xie, Yibiao; Sun, Shuiyu; Liu, Jingyong; Lin, Weixiong; Chen, Nanwei; Ye, Maoyou


    The effect of six additives (CaCO3, HZSM-5, CaO, Al2O3, FeOOH and Ca(OH)2) on the generation, migration, transformation and escaping behaviours of typical gaseous pollutants in the pyrolysis process were studied by vacuum pyrolysis experiments on epoxy resin powder from waste printed circuit boards with tube furnace. The results show that the additives Al2O3, CaO, Ca(OH) 2 and FeOOH could reduce the yield of the gas phase. The removal rates of pollutants, such as benzene, toluene, ethyl benzene, phenol, p-xylene, HBr, NO2 and SO2 in the gaseous products, has changed variously with the increasing percentage of the above additives. Judging from the control of gas-phase pollutant discharge, the calcium-base additives are superior to the others. Ca(OH)2 has the best inhibition effect among them. The increase of the pyrolysis temperature and vacuum degree enhanced the volatility of organic pollutants and weakened the Ca(OH)2 inhibition effect on organic pollutants, while it improved the removal rate of SO2. Under the condition of 500 °C pyrolysis temperature and 0.09 MPa vacuum degree, when the additive proportion of Ca(OH)2 was one-fifth, the average removal rate of pollutants in gas phase is up to 66.4%.

  17. Effect of High Temperature Storage in Vacuum, Air, and Humid Conditions on Degradation of Gold/Aluminum Wire Bonds in PEMs (United States)

    Teverovsky, Alexander


    Microcircuits encapsulated in three plastic package styles were stored in different environments at temperatures varying from 130 C to 225 C for up to 4,000 hours in some cases. To assess the effect of oxygen, the parts were aged at high temperatures in air and in vacuum chambers. The effect of humidity was evaluated during long-term highly accelerated temperature and humidity stress testing (HAST) at temperatures of 130 C and 150 C. High temperature storage testing of decapsulated microcircuits in air, vacuum, and HAST chambers was carried out to evaluate the role of molding compounds in the environmentally-induced degradation and failure of wire bonds (WB). This paper reports on accelerating factors of environment and molding compound on WB failures. It has been shown that all environments, including oxygen, moisture, and the presence of molding compounds reduce time-to-failures compared to unencapsulated devices in vacuum conditions. The mechanism of the environmental effect on KB degradation is discussed.

  18. Use of a home vacuum-assisted closure device in the burn population is both cost-effective and efficacious. (United States)

    Mushin, Oren P; Bogue, Jarrod T; Esquenazi, Mica D; Toscano, Nicole; Bell, Derek E


    The vacuum assisted closure device (VAC) improves wound-healing when utilized as a bolster to secure split thickness skin grafts (STSG). Patients typically remain hospitalized for VAC therapy; however, home VACs (hVAC) are now available. Limited studies examine burns treated with hVAC as a STSG bolster. A retrospective study of records from an ABA verified regional burn center was conducted over 23 months. Patients included STSGs for burn. Data points included demographics, burn mechanism and location, graft characteristics, hospital length of stay (LOS), and time to heal. Fifty patients were included, with average age of 39 years (range <1-83years). Average burn TBSA was 1.27±1.42 (range 0.05-8.18). Grafted area average was 102.9±128.1cm(2). The most commonly treated areas were the leg/foot, thigh, and torso (53%, 16%, and 16%, respectively). Average LOS was 1.1±1.2 days. Mean graft-take was 99.2±2.8% with one patient undergoing repeat STSG. Average post-operative time to heal was 16±6 days. A 5-day inpatient stay with a VAC costs an average of $34,635, compared to $9134 for an hVAC over the same period. The hVAC is a cost-effective STSG bolster in the burn population for appropriate candidates. Excellent graft-take and low morbidity rates imply that this is an efficacious alternative for STSG bolster. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

  19. Effect of necrosectomy and vacuum-assisted closure (VAC on mitochondrial function and oxidative stress markers in severe acute pancreatitis

    Directory of Open Access Journals (Sweden)

    Alejandra Guillermina Miranda-Díaz


    Full Text Available Background: Severe acute pancreatitis (SAP is associated with high morbidity and mortality. Objective: To evaluate whether necrosectomy, alone or combined with vacuum-assisted closure (VAC, has any additional beneficial effects on mitochondrial function and/or oxidative stress markers in SAP. Methods: Patients with SAP, APACHE II score > 8, and inadequate response to management in an intensive care unit were included in a prospective observational study. Sixteen underwent necrosectomy and 24 underwent necrosectomy plus VAC every 48 h. Patients were then categorized as survivors or deceased. Submitochondrial membrane fluidity of platelets and F0F1-ATPase hydrolysis were measured to represent mitochondrial function. Oxidative/nitrosative stress was measured using lipoperoxides (LPOs, nitric oxide (NO, erythrocyte membrane fluidity, and total antioxidant capacity (TAC. Results: Membrane fluidity in submitochondrial particles of platelets remained significantly increased throughout the study, and then eventually rised in deceased patients managed with necrosectomy + VAC vs. survivors (p < 0.041. Hydrolysis was significantly increased from baseline to endpoint in all patients, predominating in those who died after management with necrosectomy (p < 0.03. LPO increased in all patients, and necrosectomy was more efficient for the eventual decrease in survivors (p < 0.039. NO was found to be increased for the baseline-endpoint result among both survivors and deceased patients with both management options. Erythrocyte membrane fluidity was increased in survivors managed with necrosectomy + VAC, and eventually returned to normal (p < 0.045. TAC was found to be consumed in all patients for the duration of the study. Conclusions: Mitochondrial dysfunction and oxidative/nitrosative stress with significant systemic antioxidant consumption were found. Necrosectomy was more efficient and better cleared LPOs. Necrosectomy + VAC improved erythrocyte membrane

  20. Effect of necrosectomy and vacuum-assisted closure (VAC) on mitochondrial function and oxidative stress markers in severe acute pancreatitis. (United States)

    Miranda-Díaz, Alejandra Guillermina; Hermosillo-Sandoval, José Manuel; Gutiérrez-Martínez, Carlos Alberto; Rodríguez-Carrizalez, Adolfo Daniel; Román-Pintos, Luis Miguel; Cardona-Muñoz, Ernesto Germán; Pacheco-Moisés, Fermín Paul; Arias-Carvajal, Óscar


    Severe acute pancreatitis (SAP) is associated with high morbidity and mortality. To evaluate whether necrosectomy, alone or combined with vacuum-assisted closure (VAC), has any additional beneficial effects on mitochondrial function and/or oxidative stress markers in SAP. Patients with SAP, APACHE II score > 8, and inadequate response to management in an intensive care unit were included in a prospective observational study. Sixteen underwent necrosectomy and 24 underwent necrosectomy plus VAC every 48 h. Patients were then categorized as survivors or deceased. Submitochondrial membrane fluidity of platelets and F0F1-ATPase hydrolysis were measured to represent mitochondrial function. Oxidative/nitrosative stress was measured using lipoperoxides (LPOs), nitric oxide (NO), erythrocyte membrane fluidity, and total antioxidant capacity (TAC). Membrane fluidity in submitochondrial particles of platelets remained significantly increased throughout the study, and then eventually rised in deceased patients managed with necrosectomy + VAC vs. survivors (p < 0.041). Hydrolysis was significantly increased from baseline to endpoint in all patients, predominating in those who died after management with necrosectomy (p < 0.03). LPO increased in all patients, and necrosectomy was more efficient for the eventual decrease in survivors (p < 0.039). NO was found to be increased for the baseline-endpoint result among both survivors and deceased patients with both management options. Erythrocyte membrane fluidity was increased in survivors managed with necrosectomy + VAC, and eventually returned to normal (p < 0.045). TAC was found to be consumed in all patients for the duration of the study. Mitochondrial dysfunction and oxidative/ nitrosative stress with significant systemic antioxidant consumption were found. Necrosectomy was more efficient and better cleared LPOs. Necrosectomy + VAC improved erythrocyte membrane fluidity and increased survival.

  1. Effect of thermal annealing in vacuum on the photovoltaic properties of electrodeposited Cu2O-absorber solar cell

    Directory of Open Access Journals (Sweden)

    Dimopoulos T.


    Full Text Available Heterojunction solar cells were fabricated by electrochemical deposition of p-type, cuprous oxide (Cu2O absorber on sputtered, n-type ZnO layer. X-ray diffraction measurements revealed that the as-deposited absorber consists mainly of Cu2O, but appreciable amounts of metallic Cu and cupric oxide (CuO are also present. These undesired oxidation states are incorporated during the deposition process and have a detrimental effect on the photovoltaic properties of the cells. The open circuit voltage (VOC, short circuit current density (jSC, fill factor (FF and power conversion efficiency (η of the as-deposited cells are 0.37 V, 3.71 mA/cm2, 35.7% and 0.49%, respectively, under AM1.5G illumination. We show that by thermal annealing in vacuum, at temperatures up to 300 °C, compositional purity of the Cu2O absorber could be obtained. A general improvement of the heterojunction and bulk materials quality is observed, reflected upon the smallest influence of the shunt and series resistance on the transport properties of the cells in dark and under illumination. Independent of the annealing temperature, transport is dominated by the space-charge layer generation-recombination current. After annealing at 300 °C the solar cell parameters could be significantly improved to the values of: VOC = 0.505 V, jSC = 4.67 mA/cm2, FF = 47.1% and η = 1.12%.

  2. The plastic fly: the effect of sustained fluctuations in adult food supply on life-history traits. (United States)

    van den Heuvel, J; Zandveld, J; Mulder, M; Brakefield, P M; Kirkwood, T B L; Shanley, D P; Zwaan, B J


    Many adult traits in Drosophila melanogaster show phenotypic plasticity, and the effects of diet on traits such as lifespan and reproduction are well explored. Although plasticity in response to food is still present in older flies, it is unknown how sustained environmental variation affects life-history traits. Here, we explore how such life-long fluctuations of food supply affect weight and survival in groups of flies and affect weight, survival and reproduction in individual flies. In both experiments, we kept adults on constant high or low food and compared these to flies that experienced fluctuations of food either once or twice a week. For these 'yoyo' groups, the initial food level and the duration of the dietary variation differed during adulthood, creating four 'yoyo' fly groups. In groups of flies, survival and weight were affected by adult food. However, for individuals, survival and reproduction, but not weight, were affected by adult food, indicating that single and group housing of female flies affects life-history trajectories. Remarkably, both the manner and extent to which life-history traits varied in relation to food depended on whether flies initially experienced high or low food after eclosion. We therefore conclude that the expression of life-history traits in adult life is affected not only by adult plasticity, but also by early adult life experiences. This is an important but often overlooked factor in studies of life-history evolution and may explain variation in life-history experiments. © 2014 The Authors. Journal of Evolutionary Biology published by John Wiley & Sons Ltd on behalf of European Society for Evolutionary Biology.

  3. Effect of Islanding and Telecontrolled Switches on Distribution System Reliability Considering Load and Green-Energy Fluctuations

    Directory of Open Access Journals (Sweden)

    Stefania Conti


    Full Text Available To improve electrical distribution network reliability, some portions of the network could operate in autonomous mode, provided that the related technical issues are addressed. More specifically, when there is not a path from those portions to the primary substation due to a fault in the network, such portions could be disconnected from the main network and supplied by local generation only. Such a mode of operation is known as “intentional islanding” and its effectiveness, in terms of adequacy, depends on the ability of the local generation to meet the island’s load. In fact, the ratio between the available local generation and load demand can frequently change during islanding due to load variations and, especially, due to the strongly irregular behavior of the primary energy sources of renewable generators. This paper proposes an analytical formulation to assess local generation adequacy during intentional islanding, accounting for the aforementioned variations. More specifically, the fluctuations of load and green-energy generators during islanding are modeled by means of Markov chains, whose output quantities are encompassed in the proposed analytical formulation. Such a formulation is used by the analytical equations of load points’ outage rate and duration. The evaluation of the reliability indices accounts for a protection scheme based on an appropriate communication infrastructure. Therefore, a brief overview on the telecommunications technologies has been presented with reference to their suitability for the specific application. In particular, distribution network safety issues have been considered as the main concern. The results show that neglecting load and generation fluctuations leads to a strong overestimation of the ability of distributed generators to meet the island load. Through a case study it is observed that the error on the load point outage rate is greater than the one affecting the outage duration.

  4. Direct sampling of electric-field vacuum fluctuations

    National Research Council Canada - National Science Library

    Riek, C; Seletskiy, D V; Moskalenko, A S; Schmidt, J F; Krauspe, P; Eckart, S; Eggert, S; Burkard, G; Leitenstorfer, A


    .... The ground-state electric-field variance is inversely proportional to the four-dimensional space-time volume, which we sampled electro-optically with tightly focused laser pulses lasting a few femtoseconds...

  5. Telecommunication monitoring is a method for studies of the effect of heliomagnetic fluctuations on cardiac function. (United States)

    Chibisov, S M; Vishnevsky, V V; Ragulskaya, M V


    This paper presents the results of 9-year biogeophysical monitoring (1998-2007) of spatial and time effects of space weather and atmospheric and climatic factors on the status of normal subjects, which was carried out simultaneously in geographical areas situated at different latitudes. Requirements to conditions of long-term telecommunication biogeophysical monitoring studies are formulated, providing the reliability and reproducibility of the experiment results. The results indicate that the role of atmospheric and climatic factors in modification of dynamic regimens of human body functioning is significantly higher in subjects living at lower latitudes. The spatial and time regularities of the effects of space and physical factors on human body were detected (the latitude, time, trigger, amplitude, synergetic, and cumulative effects of the population averaging of the reaction). These effects indicate that human body belongs to a class of open nonlinear dynamic systems with all characteristics intrinsic of it.

  6. The effect of temperature on photosynthetic induction under fluctuating light in Chrysanthemum morifolium

    DEFF Research Database (Denmark)

    Öztürk, Isik; Ottosen, Carl-Otto; Ritz, Christian


    The temporal course of photosynthetic induction was investigated on Chrysanthemum morifolium under dynamic light and temperature conditions to evaluate the effect of climatic variables on photosynthetic induction. The Plant material was grown under uniform, controlled conditions and analyzed...

  7. The effect of developmental temperature fluctuation on wing traits and stressed locomotor performance in Drosophila melanogaster, and its dependence on heterozygosity

    DEFF Research Database (Denmark)

    Kjaersgaard, Anders; Le, Nguyet; Demontis, Ditte


    temperature fluctuation during development affect adult size and wing shape in Drosophila melanogaster? If so, are the effects predictable? Do they depend on heterozygosity? Do fluctuations in developmental temperature affect adult physiological performance at high temperature? Methods: We tested the effect...... of one fluctuating (21 degrees C/29 degrees C) and several constant (21 degrees C, 23 degrees C, 25 degrees C, 27 degrees C, 29 degrees C) developmental temperature regimes on three wing morphometric traits (wing length, wing width, and wing shape) in an experiment using three inbred lines of D...... temperatures also showed greater plasticity in wing aspect. Conclusion: The widespread use of constant developmental temperatures in laboratory experiments may lead to overestimation of performance....

  8. Skewness of elliptic flow fluctuations (United States)

    Giacalone, Giuliano; Yan, Li; Noronha-Hostler, Jacquelyn; Ollitrault, Jean-Yves


    Using event-by-event hydrodynamic calculations, we find that the fluctuations of the elliptic flow (v2) in the reaction plane have a negative skew. We compare the skewness of v2 fluctuations to that of initial eccentricity fluctuations. We show that skewness is the main effect lifting the degeneracy between higher-order cumulants, with negative skew corresponding to the hierarchy v2{4 } >v2{6 } observed in Pb+Pb collisions at the CERN Large Hadron Collider. We describe how the skewness can be measured experimentally and show that hydrodynamics naturally reproduces its magnitude and centrality dependence.

  9. Maintenance measures for preservation and recovery of permeable pavement surface infiltration rate--The effects of street sweeping, vacuum cleaning, high pressure washing, and milling. (United States)

    Winston, Ryan J; Al-Rubaei, Ahmed M; Blecken, Godecke T; Viklander, Maria; Hunt, William F


    The surface infiltration rates (SIR) of permeable pavements decline with time as sediment and debris clog pore spaces. Effective maintenance techniques are needed to ensure the hydraulic functionality and water quality benefits of this stormwater control. Eight different small-scale and full-scale maintenance techniques aimed at recovering pavement permeability were evaluated at ten different permeable pavement sites in the USA and Sweden. Maintenance techniques included manual removal of the upper 2 cm of fill material, mechanical street sweeping, regenerative-air street sweeping, vacuum street sweeping, hand-held vacuuming, high pressure washing, and milling of porous asphalt. The removal of the upper 2 cm of clogging material did not significantly improve the SIR of concrete grid paves (CGP) and permeable interlocking concrete pavers (PICP) due to the inclusion of fines in the joint and bedding stone during construction, suggesting routine maintenance cannot overcome improper construction. For porous asphalt maintenance, industrial hand-held vacuum cleaning, pressure washing, and milling were increasingly successful at recovering the SIR. Milling to a depth of 2.5 cm nearly restored the SIR for a 21-year old porous asphalt pavement to like-new conditions. For PICP, street sweepers employing suction were shown to be preferable to mechanical sweepers; additionally, maintenance efforts may become more intensive over time to maintain a threshold SIR, as maintenance was not 100% effective at removing clogging material. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Correlated interaction fluctuations in photosynthetic complexes

    CERN Document Server

    Vlaming, Sebastiaan M


    The functioning and efficiency of natural photosynthetic complexes is strongly influenced by their embedding in a noisy protein environment, which can even serve to enhance the transport efficiency. Interactions with the environment induce fluctuations of the transition energies of and interactions between the chlorophyll molecules, and due to the fact that different fluctuations will partially be caused by the same environmental factors, correlations between the various fluctuations will occur. We argue that fluctuations of the interactions should in general not be neglected, as these have a considerable impact on population transfer rates, decoherence rates and the efficiency of photosynthetic complexes. Furthermore, while correlations between transition energy fluctuations have been studied, we provide the first quantitative study of the effect of correlations between interaction fluctuations and transition energy fluctuations, and of correlations between the various interaction fluctuations. It is shown t...

  11. Phenomenology of the vacuum in quantum electrodynamics and beyond

    Energy Technology Data Exchange (ETDEWEB)

    Doebrich, Babette


    Determining forces that arise by the restriction of the fluctuation modes of the vacuum by the insertion of boundaries or the observation of altered light propagation in external fields is a versatile means to investigate the vacuum structure of quantum electrodynamics. For these quantum vacuum probes, the vacuum can be understood and effectively modeled as a medium. Investigating the properties of this medium cannot only test and broaden our understanding of known interactions but can also be a valuable tool in the search for particles at low energy scales which arise in extensions of the standard model. In this thesis, we first study the geometry dependence of fluctuation modes in the Dirichlet-scalar analog of Casimir-Polder forces between an atom and a surface with arbitrary uniaxial corrugations. To this end we employ a technique which is fully nonperturbative in the height profile. We parameterize the differences to the distance dependencies in the planar limit in terms of an anomalous dimension quantifying the power-law deviation from the planar case. In numerical studies of experimentally relevant corrugations, we identify a universal regime of the anomalous dimension at larger distances. We argue that this universality arises as the relevant fluctuations average over corrugation structures smaller than the atom-wall distance. Turning to modified light propagation as a probe of the quantum vacuum, we show that a combination of strong, pulsed magnets and gravitational-wave interferometers can not only facilitate the detection of strong-field QED phenomena, but also significantly enlarges the accessible parameter space of hypothetical hidden-sector particles. We identify pulsed magnets as a suitable strong-field source to induce quantum nonlinearities, since their pulse frequency can be perfectly matched with the domain of highest sensitivity of modern gravitational-wave interferometers. Pushing current laboratory field-strengths to their limits, we suggest a

  12. Effects of Dosage Sequence on the Efficacy of Nonfumigant Nematicides, Plantain Yields, and Nematode Seasonal Fluctuations as influenced by Rainfall. (United States)

    Badra, T; Caveness, F E


    Four nonfumigant nematicides applied three times during the wet season were used to study dosage sequence and nematicide effectiveness. Control of Helicotylenchus multicinctus (Cobb) Thorne and Meloidogyne javanica (Treub) Chitwood increased plantain (Musa AAB) yields. The nematicide (aldicarb, carbofuran, oxamyl, and miral) performance and yield response varied with dosage sequences. Applications of 2, 3, and 2 g ai/tree in March, July, and October (sequence I), respectively, gave greater control of M. javanica than did applications of 3, 2, and 2 g ai/tree in March, June, and September (sequence II), respectively. However, the high initial dose sequence was effective against H. multicinctus. Persistence of the different nematicides differed over the 14-month experimental period. Miral, aldicarb, and carbofuran were the most effective treatments against either species by the end of the wet and dry seasons. Dry season residual nematode populations were significantly lower in nematicide treated than in control plots. Yield increases over controls were 96.9, 90.1, 78.4, and 70.1% for carbofuran applied by sequence II, aldicarb by II and I, and oxantyl by II, respectively. Nematode populations directly fluctuated with rainfall and dropped to low (H. multicinctus) or to undetectable (M. javanica juveniles) levels during the dry season. Of the two nematodes studied, the more serious pest to plantain was H. multicinctus; it was tolerant to drought and survived the dry season in untreated soils.

  13. The Effect of Long Memory in Volatility on Stock Market Fluctuations

    DEFF Research Database (Denmark)

    Christensen, Bent Jesper; Nielsen, Morten Ørregaard

    on returns. Asset pricing theory imposes testable cross- equation restrictions on the system that are not rejected in our preferred specifications, which include a strong financial leverage effect. We show that the impact of volatility shocks on stock prices is small and short-lived, in spite of a positive...

  14. The Effect of Long Memory in Volatility on Stock Market Fluctuations

    DEFF Research Database (Denmark)

    Christensen, Bent Jesper; Nielsen, Morten Ørregaard

    on returns. Asset pricing theory imposes testable cross-equation restrictions on the system that are not rejected in our preferred specifications, which include a strong financial leverage effect. We show that the impact of volatility shocks on stock prices is small and short-lived, in spite of a positive...

  15. Reduce fluctuations in capacity to improve the accessibility of radiotherapy treatment cost-effectively

    NARCIS (Netherlands)

    joustra, P. E.; Kolfin, R.; van Dijk, N. M.; Koning, C. C. E.; Bakker, P. J. M.


    This paper is motivated by a case study to reduce the throughput times for radiotherapy treatment. The goal is to find a cost-effective way to meet future throughput targets. A combination of queuing theory and computer simulation was used. First, computer simulation to detect the bottleneck(s) in a

  16. Deformation and concentration fluctuations under stretching in a polymer network with free chains. The ``butterfly`` effect; Fluctuations de deformation et de concentration sous etirement dans un reseau polymere contenant des chaines libres. L`effet ``papillon``

    Energy Technology Data Exchange (ETDEWEB)

    Ramzi, A.


    Small Angle Neutron Scattering gives access to concentration fluctuations of mobile labeled polymer chains embedded in a polymer network. At rest they appear progressively larger than for random mixing, with increasing ratio. Under uniaxial stretching, they decrease towards ideal mixing along the direction perpendicular to stretching, and can grow strongly along the parallel one, including the zero scattering vector q limit. This gives rise to intensity contours with double-winged patterns, in the shape of the figure `8`, or of `butterfly`. Random crosslinking and end-linking of monodisperse chains have both been studied. The strength of the `butterfly` effect increases with the molecular weight of the free chains, the crosslinking ratio, the network heterogeneity, and the elongation ratio. Eventually, the signal collapses on an `asymptotic` function I(q), of increasing correlation length with the elongation ratio. Deformation appears heterogeneous, maximal for soft areas, where the mobile chains localize preferentially. This could be due to spontaneous fluctuations, or linked to frozen fluctuations of the crosslink density. However, disagreement with the corresponding theoretical expressions makes it necessary to account for the spatial correlations of crosslink density, and their progressive unscreening as displayed by the asymptotic behavior. Networks containing pending labeled chains and free labeled stars lead to more precise understanding of the diffusion of free species and the heterogeneity of the deformation. It seems that the latter occurs even without diffusion for heterogeneous enough networks. In extreme cases (of the crosslinking parameters), the spatial correlations display on apparent fractal behavior, of dimensions 2 to 2.5, which is discussed here in terms of random clusters. 200 refs., 95 figs., 21 tabs., 10 appends.

  17. Quantum entanglement and temperature fluctuations. (United States)

    Ourabah, Kamel; Tribeche, Mouloud


    In this paper, we consider entanglement in a system out of equilibrium, adopting the viewpoint given by the formalism of superstatistics. Such an approach yields a good effective description for a system in a slowly fluctuating environment within a weak interaction between the system and the environment. For this purpose, we introduce an alternative version of the formalism within a quantum mechanical picture and use it to study entanglement in the Heisenberg XY model, subject to temperature fluctuations. We consider both isotropic and anisotropic cases and explore the effect of different temperature fluctuations (χ^{2}, log-normal, and F distributions). Our results suggest that particular fluctuations may enhance entanglement and prevent it from vanishing at higher temperatures than those predicted for the same system at thermal equilibrium.

  18. Microfabricated triggered vacuum switch (United States)

    Roesler, Alexander W [Tijeras, NM; Schare, Joshua M [Albuquerque, NM; Bunch, Kyle [Albuquerque, NM


    A microfabricated vacuum switch is disclosed which includes a substrate upon which an anode, cathode and trigger electrode are located. A cover is sealed over the substrate under vacuum to complete the vacuum switch. In some embodiments of the present invention, a metal cover can be used in place of the trigger electrode on the substrate. Materials used for the vacuum switch are compatible with high vacuum, relatively high temperature processing. These materials include molybdenum, niobium, copper, tungsten, aluminum and alloys thereof for the anode and cathode. Carbon in the form of graphitic carbon, a diamond-like material, or carbon nanotubes can be used in the trigger electrode. Channels can be optionally formed in the substrate to mitigate against surface breakdown.

  19. Electron emission of cathode holder of vacuum diode of an intense electron-beam accelerator and its effect on the output voltage

    Directory of Open Access Journals (Sweden)

    Xin-Bing Cheng


    Full Text Available The vacuum diode which is used to generate relativistic electron beams is one of the most important parts of a pulsed-power modulator. In this paper, the electron emission of cathode holder of a vacuum diode and its effect on the output voltage is investigated by experiments on an intense electron-beam accelerator with 180 ns full width at half maximum and 200–500 kV output voltage. First, the field emission is analyzed and the electric field of the vacuum chamber is calculated. Then, the flatness of the output voltage is discussed before and after adding an insulation plate when a water load is used. It is found that the electron emission at the edges of the cathode holder is the main reason to cause the change of the flatness. Last, a piece of polyester film is used as a target to further show the electron emission of the cathode holder. This analysis shows that decreasing the electron emission of the cathode holder in such a pulse power modulator could be a good way to improve the quality of the output voltage.

  20. Effect of chitosan treatments on quality parameters of fresh refrigerated swordfish (Xiphias gladius) steaks stored in air and under vacuum conditions. (United States)

    Tsiligianni, Maria; Papavergou, Eikaterini; Soultos, Nikolaos; Magra, Taxiarhoula; Savvaidis, Ioannis N


    The present study examined the effect of chitosan (1.0% w/v) in combination with packaging on the shelf-life of fresh swordfish steaks. Treatments included the following: A (untreated, control samples stored in air), A-CH (treated with chitosan 1.0% w/v, stored in air), VP (untreated, stored under vacuum packaging) and VP-CH (treated with chitosan, stored under vacuum packaging). VP-CH significantly affected Total Viable Counts (TVC), Pseudomonas spp., H(2)S-producing bacteria (including Shewanella putrefaciens), lactic acid bacteria and Enterobacteriaceae. Production of TMA-N and TVB-N for A-CH, VP and VP-CH swordfish samples was significantly lower than for control (A) samples at day 8 of storage. Histamine formation for all treatments was low. A-CH and VP-CH resulted in significantly lower levels of putrescine, cadaverine and tyramine (day 8) as compared to A and VP swordfish samples. Results of this study indicate that the shelf-life of swordfish steaks can be extended using, either aerobic or vacuum packaging and in combination with chitosan, by approximately 4 (A-CH), 8 (VP) and 12 (VP-CH) days. Swordfish steaks treated with chitosan and stored under VP were sensorially acceptable up to 17days. The presence of chitosan (A-CH and VP-CH) did not negatively influence the taste of cooked swordfish. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Effect of vacuum and oven drying on the radical scavenging activity and nutritional contents of submerged fermented Maitake (Grifola frondosa mycelia

    Directory of Open Access Journals (Sweden)

    Kheng Yuen SIM


    Full Text Available Abstract Maitake (Grifola frondosa mycelia contain high dietary and medicinal values that have gained great attentions from consumers. Proper drying can preserve their bio-availabilities prior to subsequent processing or consumption. Pure Maitake (Grifola frondosa strain was cultivated in Mushroom Complete Medium (MCM using submerged fermentation for 14 days. Maitake mycelia were harvested and treated respectively by vacuum, oven drying treatments while the fresh mycelia were assigned as control. All the samples were tested for Total Phenolic Content, DPPH radical scavenging assays and nutritional contents. Submerged fermentation produced mycelia biomass (1.3 ± 0.1 g/L within 14 days of fermentation. Both the pH and reduced sugar content had decreased (P < 0.05 throughout fermentation. Vacuum dried mycelia had shown higher (P < 0.05 total phenolic (20.0 ± 0.4 mg GAE/g, DPPH radical scavenging activity (84.7 ± 0.1%, and soluble protein content (283.6 ± 7.1 µg/mL as compared to other treated samples. The crude protein (39.1 ± 0.2, fat (5.7 ± 0.7, ash (11.1 ± 0.3% of mycelia were well preserved using vacuum drying as compared to oven dried samples. The study has suggested that vacuum drying at 70 °C, 1000mBar has the advantage to preserve the nutritional and radical scavenging activity of high value maitake mycelia effectively at lower cost.

  2. Effective field theory of an anomalous Hall metal from interband quantum fluctuations (United States)

    Chua, Victor; Assawasunthonnet, Wathid; Fradkin, Eduardo


    We construct an effective field theory, a two-dimensional two-component metallic system described by a model with two Fermi surfaces ("pockets"). This model describes a translationally invariant metallic system with two types of fermions, each with its own Fermi surface, with forward scattering interactions. This model, in addition to the O (2 ) rotational invariance, has a U (1 )×U (1 ) symmetry of separate charge conservation for each Fermi surface. For sufficiently attractive interactions in the d -wave (quadrupolar) channel, this model has an interesting phase diagram that includes a spontaneously generated anomalous Hall metal phase. We derive the Landau-Ginzburg effective action of quadrupolar order parameter fields which enjoys an O (2 )×U (1 ) global symmetry associated to spatial isotropy and the internal U (1 ) relative phase symmetries, respectively. We show that the order parameter theory is dynamically local with a dynamical scaling of z =2 and perform a one-loop renormalization group analysis of the Landau-Ginzburg theory. The electronic liquid crystal phases that result from spontaneous symmetry breaking are studied and we show the presence of Landau damped Nambu-Goldstone modes at low momenta that is a signature of non-Fermi-liquid behavior. Electromagnetic linear response is also analyzed in both the normal and symmetry broken phases from the point of view of the order parameter theory. The nature of the coupling of electromagnetism to the order parameter fields in the normal phase is non-minimal and decidedly contains a precursor to the anomalous Hall response in the form of a order-parameter-dependent Chern-Simons term in the effective action.

  3. The Effect of Long Memory in Volatility on Stock Market Fluctuations

    DEFF Research Database (Denmark)

    Christensen, Bent Jesper; Nielsen, Morten Ørregaard


    Recent empirical evidence demonstrates the presence of an important long memory component in realized asset return volatility. We specify and estimate multivariate models for the joint dynamics of stock returns and volatility that allow for long memory in volatility without imposing this property...... on returns. Asset pricing theory imposes testable cross-equation restrictions on the system that are not rejected in our preferred specifications, which include a strong financial leverage effect. We show that the impact of volatility shocks on stock prices is small and short-lived, in spite of a positive...... risk-return trade-off and long memory in volatility....

  4. Effect of fluctuations of the linear feedback coefficient on the frequency spectrum of averaged temperature in a simple energy balance climate model (United States)

    Petrov, D. A.


    Using the stochastic approach, we analyze the effect of fluctuations of the linear feedback coefficient in a simple zero-dimensional energy balance climate model on the frequency spectrum of averaged temperature. An expression is obtained for the model spectrum in the weak noise approximation. Its features are investigated in two cases: when the frequency spectrum of the feedback coefficient is a constant (white noise) and when the spectrum contains one resonant frequency and has a Lorentz form. We consider the issue whether the feedback coefficient fluctuations can be an independent mechanism for a qualitative change in the spectrum of the climate system.

  5. Dilatonic black holes in gravity's rainbow with a nonlinear source: the effects of thermal fluctuations (United States)

    Hendi, S. H.; Panah, B. Eslam; Panahiyan, S.; Momennia, M.


    This paper is devoted to an investigation of nonlinearly charged dilatonic black holes in the context of gravity's rainbow with two cases: (1) by considering the usual entropy, (2) in the presence of first order logarithmic correction of the entropy. First, exact black hole solutions of dilatonic Born-Infeld gravity with an energy dependent Liouville-type potential are obtained. Then, thermodynamic properties of the mentioned cases are studied, separately. It will be shown that although mass, entropy and the heat capacity are modified due to the presence of a first order correction, the temperature remains independent of it. Furthermore, it will be shown that divergences of the heat capacity, hence phase transition points are also independent of a first order correction, whereas the stability conditions are highly sensitive to variation of the correction parameter. Except for the effects of a first order correction, we will also present a limit on the values of the dilatonic parameter and show that it is possible to recognize AdS and dS thermodynamical behaviors for two specific branches of the dilatonic parameter. In addition, the effects of nonlinear electromagnetic field and energy functions on the thermodynamical behavior of the solutions will be highlighted and dependency of critical behavior, on these generalizations will be investigated.

  6. Ionospheric anomaly due to seismic activities-III: correlation between night time VLF amplitude fluctuations and effective magnitudes of earthquakes in Indian sub-continent

    Directory of Open Access Journals (Sweden)

    S. Ray


    Full Text Available We present the results of an analysis of year-long (2007 monitoring of night time data of the VLF signal amplitude from the Indian Navy station VTX at 18.2 kHz, received by the Indian Centre for Space Physics, Kolkata. We analyzed this data to find out the correlation, if any, between night time amplitude fluctuation and seismic events. We found, analyzing individual cases (with magnitudes >5 as well as statistical analysis (of all the events with effective magnitudes greater than 3.5, that night time fluctuation of the signal amplitude has the highest probability to be beyond the 2σ level about three days prior to seismic events. Thus, the night time fluctuation could be considered as a precursor to enhanced seismic activities.

  7. Health Effects of Short-Term Fluctuations in Macroeconomic Conditions: The Case of Hypertension for Older Americans. (United States)

    Angrisani, Marco; Lee, Jinkook


    We investigate the health effects of short-term macroeconomic fluctuations as described by changes in unemployment rate, house, and stock market price indexes. The 'Great Recession' provides the opportunity to conduct this analysis as it involved contemporaneous shocks to the labor, housing, and stock markets. Using panel data from the Health and Retirement Study over the period 2004-2010, we relate changes in hypertension status to changes in state-level unemployment rate and house prices and to changes in stock market prices. We consider hypertension, a disease related to stress and of high prevalence among older adults, that has received little attention in the literature linking macroeconomic conditions to individual health. Our analysis exploits self-reports of hypertension diagnosis as well as directly measured blood pressure readings. Using both measures, we find that the likelihood of developing hypertension is negatively related to changes in house prices. Also, decreasing house prices lower the probability of stopping hypertension medication treatment for individuals previously diagnosed with the condition. We do not observe significant associations between hypertension and either changes in unemployment rate or stock market prices. We document heterogeneity in the estimated health effects of the recession by gender, education, asset ownership, and work status. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  8. Effect of reduced atmospheric pressure on patients with fluctuating hearing loss due to Ménière's disease. (United States)

    Younger, R; Longridge, N S; Mekjavic, I


    Subjective symptomatic and objective audiologic effects of reduced atmospheric pressure on patients with confirmed fluctuating hearing loss due to Ménière's disease were statistically assessed on a prospective basis. The effect of hypobaric environments on absolute hearing thresholds was investigated in 10 normal subjects at 6,500 ft. Absolute hearing threshold levels obtained at altitude, after one hour altitude exposure, and on descent to normobaric conditions were compared with levels obtained prior to the hypobaric exposure. The results indicated slightly increasing sensitivity of the audiometer headphones with altitude and an insignificant difference in hearing threshold when comparing the differing experimental conditions. The Ménière's disease study group of 16 patients was followed symptomatically and audiologically for one year prehypobaric exposure and for one month post-treatment. The results in this group utilizing the same experimental protocol as with normal subjects indicated a mild deterioration of hearing in the lower frequencies (1,000, 2,000 Hz and calculating the Ménière's pure tone average) despite significant improvements in the vertigo and disability components of their disease.

  9. Effect of natural antioxidants and vacuum packaging on the quality of buffalo meat nuggets during refrigerated storage. (United States)

    Sahoo, J; Anjaneyulu, A S


    Buffalo meat nuggets (BMN) were incorporated with 500 ppm sodium ascorbate, 10 ppm α-tocopherol acetate and 0.5% sodium tripolyphosphate while processing. There were three experimental groups of BMN, namely control aerobic packaged (CAP), treated aerobic packaged (TAP) and treated vacuum packaged (TVP), refrigerated and stored at 4 °C. It was observed that the treated samples (TAP and TVP) had significantly (p nuggets (TVP) had significantly (p < 0.05) lower free fatty acid content, higher lactobacilli and total anaerobe counts and markedly higher scores for flavour and overall palatability, even at the 25th day of storage. Product quality reduced as storage time increased. Use of natural antioxidants and vacuum packaging extended the shelf life of BMN from 10 to 30 days under refrigerated storage.

  10. On High Vacuum Densification of Soft Foundation Treatment

    Directory of Open Access Journals (Sweden)

    Guo Mei Ling


    Full Text Available The high vacuum densification, which inserted the vacuum tube to increase the drainage channel, set up the improved drainage system so that it can effectively reduce the underground water level, can be used for the reinforcement of the deep soft foundation. According to analyze the preparation and process of high vacuum densification, and summarize the control points of high vacuum densification, it renders great value to the constuction of soft foundation treatment.

  11. The Effect of Fluctuating Temperatures During Development on Fitness-Related Traits of Scatophaga stercoraria (Diptera: Scathophagidae)


    Kjærsgaard, Anders; Pertoldi, Cino; Loeschcke, Volker; Wolf U. Blanckenhorn


    Development of ectotherms is highly temperature dependent. Studies using variable thermal environments can improve ecological relevance of data because organisms naturally face day-to-day stochastic temperature fluctuations as well as seasonal changes in the amplitude of such daily fluctuations. The objective of this study was to investigate if, and to what extent, the use of constant temperatures is justified in studies of the model species, yellow dung fly, Scatophaga stercoraria (L.). We e...

  12. Effects of long-term population fluctuations of a top predator on invertebrate communities in subalpine ponds in Colorado


    Wissinger, S.; Whiteman, H.; Denoël, Mathieu; Greig, H.; Butkas, K.


    Experimental and comparative data from subalpine ponds with and without tiger salamanders (Ambystoma tigrinum nebulosum) suggest that this species is a keystone predator on benthic and planktonic prey communities. At our study site in central Colorado, the population size of salamanders has fluctuated cyclically over the past 20 years from fewer than 100 to over 5000 individuals. Here we present long-term benthic data that reveal taxon- and habitat-specific correlations with fluctuations in s...

  13. Vacuum Stability of Standard Model^{++}

    CERN Document Server

    Anchordoqui, Luis A.; Goldberg, Haim; Huang, Xing; Lust, Dieter; Taylor, Tomasz R.; Vlcek, Brian


    The latest results of the ATLAS and CMS experiments point to a preferred narrow Higgs mass range (m_h \\simeq 124 - 126 GeV) in which the effective potential of the Standard Model (SM) develops a vacuum instability at a scale 10^{9} -10^{11} GeV, with the precise scale depending on the precise value of the top quark mass and the strong coupling constant. Motivated by this experimental situation, we present here a detailed investigation about the stability of the SM^{++} vacuum, which is characterized by a simple extension of the SM obtained by adding to the scalar sector a complex SU(2) singlet that has the quantum numbers of the right-handed neutrino, H", and to the gauge sector an U(1) that is broken by the vacuum expectation value of H". We derive the complete set of renormalization group equations at one loop. We then pursue a numerical study of the system to determine the triviality and vacuum stability bounds, using a scan of 10^4 random set of points to fix the initial conditions. We show that, if there...

  14. Quantification of the effect of toxicants on the motility of mammary organoid by OCT fluctuation spectroscopy (Conference Presentation) (United States)

    Yu, Xiao; Fuller, Ashley M.; Troester, Melissa A.; Oldenburg, Amy L.


    OCT fluctuation spectroscopy provides a quantitative and non-invasive tool to monitor 3D mammary epithelial cell (MEC) models which recapitulate features of breast cancer in vivo. Cellular dynamic fluctuation measurements allow for assessing drug responses due to different mechanisms of inhibition in 3D models in vitro. Here we report on pre-malignant MEC responses to two toxicants: Taxol, which stabilizes microtubules against depolymerization, and has emerged as an important chemotherapeutic agent in the treatment of breast cancer, and blebbistatin, a small molecule inhibitor with high affinity and selectivity toward Myosin II. Here we propose a quantitative method for measuring toxicant responses of MECs in 3D cultures from OCT speckle fluctuation spectroscopy. OCT fluctuation spectra were quantified within the 9-440 mHz band, from which the inverse power-law exponent (α) and the fractional modulation amplitude (M) were extracted. Pre-malignant MECs treated with Taxol (0, 10 μM and 20 μM) exhibit an increase (p0.05) in α, since myosin II isn't highly expressed in non-migratory pre-malignant MECs. We demonstrated the feasibility of OCT fluctuation spectroscopy to quantify MEC toxicant response. Microtubule stabilization was found to be a major contributor to pre-malignant MEC fluctuation signals, while myosin II inhibition was not.

  15. Consumptive and nonconsumptive effects of cannibalism in fluctuating age-structured populations. (United States)

    Wissinger, Scott A; Whiteman, Howard H; Denoël, Mathieu; Mumford, Miranda L; Aubee, Catherine B


    Theory and empirical studies suggest that cannibalism in age-structured populations can regulate recruitment depending on the intensity of intraspecific competition between cannibals and victims and the nature of the cannibalism window, i.e., which size classes interact as cannibals and victims. Here we report on a series of experiments that quantify that window for age-structured populations of salamander larvae and paedomorphic adults. We determined body size limits on cannibalism in microcosms and then the consumptive and nonconsumptive (injuries, foraging and activity, diet, growth) effects on victims in mesocosms with seminatural levels of habitat complexity and alternative prey. We found that cannibalism by the largest size classes (paedomorphs and > or = age 3+ yr larvae) occurs mainly on young-of-the-year (YOY) victims. Surviving YOY and other small larvae had increased injuries, reduced activity levels, and reduced growth rates in the presence of cannibals. Data on YOY survival in an experiment in which we manipulated the density of paedomorphs combined with historical data on the number of cannibals in natural populations indicate that dominant cohorts of paedomorphs can cause observed recruitment failures. Dietary data indicate that ontogenetic shifts in diet should preclude strong intraspecific competition between YOY and cannibals in this species. Thus our results are consistent with previous empirical and theoretical work that suggests that recruitment regulation by cannibalism is most likely when YOY are vulnerable to cannibalism but have low dietary overlap with cannibals. Understanding the role of cannibalism in regulating recruitment in salamander populations is timely, given the widespread occurrences of amphibian decline. Previous studies have focused on extrinsic (including anthropogenic) factors that affect amphibian population dynamics, whereas the data presented here combined with long-term field observations suggest the potential for

  16. The 4-dimensional plant: effects of wind- induced canopy movement on light fluctuations and photosynthesis

    Directory of Open Access Journals (Sweden)

    Alexandra Jacquelyn Burgess


    Full Text Available Physical perturbation of a plant canopy brought about by wind is a ubiquitous phenomenon and yet its biological importance has often been overlooked. This is partly due to the complexity of the issue at hand: wind-induced movement (or mechanical excitation is a stochastic process which is difficult to measure and quantify; plant motion is dependent upon canopy architectural features which, until recently, were difficult to accurately represent and model in 3-dimensions; light patterning throughout a canopy is difficult to compute at high-resolutions, especially when confounded by other environmental variables. Recent studies have reinforced the expectation that canopy architecture is a strong determinant of productivity and yield; however, links between the architectural properties of the plant and its mechanical properties, particularly its response to wind, are relatively unknown. As a result, biologically relevant data relating canopy architecture, light dynamics and short-scale photosynthetic responses in the canopy setting are scarce. Here, we hypothesise that wind-induced movement will have large consequences for the photosynthetic productivity of our crops due to its influence on light patterning. To address this issue, in this study we combined high resolution 3D reconstructions of a plant canopy with a simple representation of canopy perturbation as a result of wind using solid body rotation in order to explore the potential effects on light patterning, interception and photosynthetic productivity. We looked at two different scenarios: firstly a constant distortion where a rice canopy was subject to a permanent distortion throughout the whole day; and secondly, a dynamic distortion, where the canopy was distorted in incremental steps between two extremes at set time points in the day. We find that mechanical canopy excitation substantially alters light dynamics; light distribution and modelled canopy carbon gain. We then discuss methods

  17. Dynamical Casimir effect in a Josephson metamaterial


    Lahteenmaki, Pasi; Paraoanu, G. S.; Hassel, Juha; Hakonen, Pertti J.


    The zero-point energy stored in the modes of an electromagnetic cavity has experimentally detectable effects, giving rise to an attractive interaction between the opposite walls, the static Casimir effect. A dynamical version of this effect was predicted to occur when the vacuum energy is changed either by moving the walls of the cavity or by changing the index of refraction, resulting in the conversion of vacuum fluctuations into real photons. Here, we demonstrate the dynamical Casimir effec...

  18. On the Independent Determination of the Ultimate Density of Physical Vacuum

    Directory of Open Access Journals (Sweden)

    Belyakov A. V.


    Full Text Available In this paper, we attempt to present physical vacuum as a topologically non-unitary coherent surface. This representation follows with J. A. Wheeler's idea about fluctuating topology, and provides a possibility to express some parameters of the unit space element through the fundamental constants. As a result, we determined the ultimate density of physical vacuum without use of Hubble's constant.

  19. On the effect of electron temperature fluctuations on turbulent heat transport in the edge plasma of tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Baudoin, C.; Tamain, P.; Ciraolo, G.; Futtersack, R.; Gallo, A.; Ghendrih, P.; Nace, N.; Norscini, C. [CEA, IRFM, Saint-Paul-lez-Durance (France); Marandet, Y. [Aix-Marseille Universite, CNRS, PIIM, UMR 7345, Marseille (France)


    In this paper we study the impact of electron temperature fluctuations in a two-dimensional turbulent model. This modification adds a second linear instability, known as sheath-driven conducting-wall instability, with respect to the previous isothermal model only driven by the interchange instability. Non-linear simulations, backed up by the linear analysis, show that the additional mechanism can change drastically the dynamics of turbulence (scales, density-potential correlation, and statistical momentum). Moreover, its importance relatively to the interchange instability should be more significant in the private flux region than in the main scrape of layer. Its effect on heat transport is also investigated for different regimes of parameters, results show that both instabilities are at play in the heat transport. Finally, the sheath negative resistance instability could be responsible for the existence of corrugated heat flux profiles in the scrape-off layer leading to a multiple decay length. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Gambling with Superconducting Fluctuations (United States)

    Foltyn, Marek; Zgirski, Maciej


    Josephson junctions and superconducting nanowires, when biased close to superconducting critical current, can switch to a nonzero voltage state by thermal or quantum fluctuations. The process is understood as an escape of a Brownian particle from a metastable state. Since this effect is fully stochastic, we propose to use it for generating random numbers. We present protocol for obtaining random numbers and test the experimentally harvested data for their fidelity. Our work is prerequisite for using the Josephson junction as a tool for stochastic (probabilistic) determination of physical parameters such as magnetic flux, temperature, and current.


    Energy Technology Data Exchange (ETDEWEB)

    William S. McPhee


    The objective of this project is to improve the productivity and lower the expense of existing vacuum blasting technology. This technology is used to remove radioactive contamination, PCBs, and lead-based paint and provides worker protection by continuously recycling the material and dust for the decontamination tasks. The proposed work would increase the cleaning rate and provide safe and cost-effective decontamination of the DOE sites. This work focuses on redesigning and improving existing vacuum blasting technology including blast head nozzles, ergonomic handling of the blast head by reducing its weight; brush-ring design, vacuum level regulator, efficiency of the dust separator, and operational control sensors. The redesign is expected to enhance the productivity and economy of the vacuum blasting system by at least 50% over current vacuum blasting systems. There are three phases in the project. Phase I consists of developing and testing mathematical models. Phase II consists of pre-prototype design and fabrication and pre-prototype unit testing. Phase III consists of prototype design and field verification testing. In phase I, mathematical models are developed and analyzed for the nozzle, blast head, wind curtain, and dust separator, first as individual devices and then combined as an integrated model. This allows study of respective airflow and design parameters. The Contractor shall, based on the results of the mathematical modeling studies, design experimental models of the components and test these models. In addition, the Contractor shall develop sensors to detect the relationship of the blast head to the blast surfaces and controls to minimize the dependency on an operator's skill and judgment to obtain optimum positioning, as well as real-time characterization sensors to determine as the blast head is moving the depth to which coatings must be removed, thereby improving production and minimizing waste. In phase II, the Contractor shall design and

  2. The Effect of Water Table Fluctuation and its Salinity on Fe Crystal and Noncrystal in some Khuzestan Soils

    Directory of Open Access Journals (Sweden)

    mostafa Pajohannia


    Full Text Available Introduction: Iron is found in different forms in the soil. In the primary minerals, iron is found as Fe3+ or Fe2+ which converted to Fe2+ and released in unsuitable reduction conditions. Minerals such as sulfide or chlorine and bicarbonate can affect and change the different forms soil Fe. FeAs these elements are abundance in groundwater or soil, they are capable to react chemically with Fe and change different Fe forms and also may deposit or even leach them by increasing its solubility in the soil. Water table fluctuation is a regular phenomenon in Khuzestan that Fe forms change under these situations. The study of Fe oxide forms and its changes can be applied for evaluation of soil development. Therefore, the aim of this study is the water table fluctuation and its quality effects, and some physio-chemical properties on Fe oxides forms in non-saline and saline soils in Khuzestan. Materials and Methods: Soil samples were collected from two regions: saline (Abdolkhan and non-saline (South Susa regions. soil samples were collected from all horizons of 12 soil field studied profiles . The samples were analyzed for soil texture, pH, EC (soil: water ratio 1:5, organic carbon and aggregate stability (Kemper and Rosenau method. Fe forms also were extracted by two methods in all samples: di-tyonite sodium and ammonium oxalate extraction. Fe oxalate extracted was related to Feo (non crystal Fe and Fed-Feo was related to Fec (crystalline Fe. The Fe content were determined by atomic absorbtion spectrophotometer (AAS. Data were analysis in SAS and Excel software and results were presented. Results and Discussion: The results showed that texture were loamy sand to silty clay loam, OM was very poor (0.1-0.7%. The soil salinity was also 2.8-16.8 dS/m. Calcium carbonate equivalent was 38-40%. All pedons were classified in Entisols and Inceptisols according to Keys to soil taxonomy (2010. The results showed that the proportion of Fe with oxalate to di

  3. Laboratory model study of newly deposited dredger fills using improved multiple-vacuum preloading technique

    Directory of Open Access Journals (Sweden)

    Jingjin Liu


    Full Text Available Problems continue to be encountered concerning the traditional vacuum preloading method in field during the treatment of newly deposited dredger fills. In this paper, an improved multiple-vacuum preloading method was developed to consolidate newly dredger fills that are hydraulically placed in seawater for land reclamation in Lingang Industrial Zone of Tianjin City, China. With this multiple-vacuum preloading method, the newly deposited dredger fills could be treated effectively by adopting a novel moisture separator and a rapid improvement technique without sand cushion. A series of model tests was conducted in the laboratory for comparing the results from the multiple-vacuum preloading method and the traditional one. Ten piezometers and settlement plates were installed to measure the variations in excess pore water pressures and moisture content, and vane shear strength was measured at different positions. The testing results indicate that water discharge–time curves obtained by the traditional vacuum preloading method can be divided into three phases: rapid growth phase, slow growth phase, and steady phase. According to the process of fluid flow concentrated along tiny ripples and building of larger channels inside soils during the whole vacuum loading process, the fluctuations of pore water pressure during each loading step are divided into three phases: steady phase, rapid dissipation phase, and slow dissipation phase. An optimal loading pattern which could have a best treatment effect was proposed for calculating the water discharge and pore water pressure of soil using the improved multiple-vacuum preloading method. For the newly deposited dredger fills at Lingang Industrial Zone of Tianjin City, the best loading step was 20 kPa and the loading of 40–50 kPa produced the highest drainage consolidation. The measured moisture content and vane shear strength were discussed in terms of the effect of reinforcement, both of which indicate

  4. Quantum Fluctuation Relations


    Facchi, Paolo; Garnero, Giancarlo; Ligabò, Marilena


    We present here a set of lecture notes on exact fluctuation relations. We prove the Jarzynski equality and the Crooks fluctuation theorem, two paradigmatic examples of classical fluctuation relations. Finally we consider their quantum versions, and analyze analogies and differences with the classical case.

  5. Effect of dust charge fluctuations on dust acoustic structures in magnetized dusty plasma containing nonextensive electrons and two-temperature isothermal ions

    Energy Technology Data Exchange (ETDEWEB)

    Araghi, F. [Islamic Azad University, North Tehran Branch, Physics Department, Science Faculty (Iran, Islamic Republic of); Dorranian, D., E-mail: [Islamic Azad University, Laser Laboratory, Plasma Physics Research Center, Science and Research Branch (Iran, Islamic Republic of)


    Effect of dust electrical charge fluctuations on the nature of dust acoustic solitary waves (DASWs) in a four-species magnetized dusty plasma containing nonextensive electrons and two-temperature isothermal ions has been investigated. In this model, the negative dust electric charge is considered to be proportional to the plasma space potential. The nonlinear Zakharov–Kuznetsov (ZK) and modified Zakharov–Kuznetsov (mZK) equations are derived for DASWs by using the standard reductive perturbation method. The combined effects of electron nonextensivity and dust charge fluctuations on the DASW profile are analyzed. The different ranges of the nonextensive q-parameter are considered. The results show that solitary waves the amplitude and width of which depend sensitively on the nonextensive q-parameter can exist. Due to the electron nonextensivity and dust charge fluctuation rate, our dusty plasma model can admit both positive and negative potential solitons. The results show that the amplitude of the soliton increases with increasing electron nonextensivity, but its width decreases. Increasing the electrical charge fluctuations leads to a decrease in both the amplitude and width of DASWs.

  6. Effects of periodical salinity fluctuation on the growth, molting, energy homeostasis and molting-related gene expression of Litopenaeus vannamei (United States)

    Zhang, Dan; Guo, Xiantao; Wang, Fang; Dong, Shuanglin


    To determine the response of Litopenaeus vannamei to periodical salinity fluctuation, a 30-day experiment was conducted in laboratory. In this experiment, two salinity fluctuation amplitudes of 4 (group S4) and 10 (group S10) were designed. The constant salinity of 30 (group S0) was used as the control. Levels of shrimp growth, molting frequency (MF), cellular energy status (ATP, ADP and AMP), as well as the expression of genes encoding molt-inhibiting hormone (MIH), crustacean hyperglycemic hormone (CHH), ecdysteroid-regulated protein (ERP), and energy-related AMP-activated protein kinase (AMPK) were determined. The results showed that periodical salinity fluctuation significantly influenced all indicators except MF which ranged from 13.3% in group S10 to15.4% in group S4. In comparison with shrimps cultured at the constant salinity of 30, those in group S4 showed a significant elevation in growth rate, food conversion efficiency, cellular energy status, ERP and MIH gene transcript abundance, and a significant reduction in CHH and AMPK transcript abundance ( P vannamei may be highly capable of tolerating salinity fluctuation. When ambient salinity fluctuated at approx. 4, the increased MF and energy stores in organisms may aid to promoting shrimp growth.

  7. Use of Vacuum Degreasing for Precision Cleaning (United States)

    Fox, Eric; Edwards, Kevin; Mitchell, Mark; Boothe, Richard


    Increasingly strict environmental regulations and the consequent phase out of many effective cleaning solvents has necessitated the development of novel cleaning chemistries and technologies. Among these is vacuum degreasing, a fully enclosed process that eliminates fugitive solvent emissions, thereby reducing cost, environmental, and health related exposure impacts. The effectiveness of vacuum degreasing using modified alcohol for common aerospace contaminants is reported and compared to current and legacy solvents.

  8. Vacuum spin squeezing (United States)

    Hu, Jiazhong; Chen, Wenlan; Vendeiro, Zachary; Urvoy, Alban; Braverman, Boris; Vuletić, Vladan


    We investigate the generation of entanglement (spin squeezing) in an optical-transition atomic clock through the coupling to an optical cavity in its vacuum state. We show that if each atom is prepared in a superposition of the ground state and a long-lived electronic excited state, and viewed as a spin-1/2 system, then the collective vacuum light shift entangles the atoms, resulting in a squeezed distribution of the ensemble collective spin, without any light applied. This scheme reveals that even an electromagnetic vacuum can constitute a useful resource for entanglement and quantum manipulation. By rotating the spin direction while coupling to the vacuum, the scheme can be extended to implement two-axis twisting resulting in stronger squeezing.

  9. Handbook of vacuum technology

    CERN Document Server


    This comprehensive, standard work has been updated to remain an important resource for all those needing detailed knowledge of the theory and applications of vacuum technology. With many numerical examples and illustrations to visualize the theoretical issues.

  10. Cold Vacuum Drying Facility (United States)

    Federal Laboratory Consortium — Located near the K-Basins (see K-Basins link) in Hanford's 100 Area is a facility called the Cold Vacuum Drying Facility (CVDF).Between 2000 and 2004, workers at the...

  11. Vacuum-assisted delivery (United States)

    ... the birth canal. The vacuum uses a soft plastic cup that attaches to the baby's head with suction. ... a numbing medicine placed in the vagina. The plastic cup will be placed on the baby's head. Then, ...

  12. Effects of post-deposition vacuum annealing on film characteristics of p-type Cu2O and its impact on thin film transistor characteristics (United States)

    Han, Sanggil; Niang, Kham M.; Rughoobur, Girish; Flewitt, Andrew J.


    Annealing of cuprous oxide (Cu2O) thin films in vacuum without phase conversion for subsequent inclusion as the channel layer in p-type thin film transistors (TFTs) has been demonstrated. This is based on a systematic study of vacuum annealing effects on the sputtered p-type Cu2O as well as the performance of TFTs on the basis of the crystallographic, optical, and electrical characteristics. It was previously believed that high-temperature annealing of Cu2O thin films would lead to phase conversion. In this work, it was observed that an increase in vacuum annealing temperature leads to an improvement in film crystallinity and a reduction in band tail states based on the X-ray diffraction patterns and a reduction in the Urbach tail, respectively. This gave rise to a considerable increase in the Hall mobility from 0.14 cm2/V.s of an as-deposited film to 28 cm2/V.s. It was also observed that intrinsic carrier density reduces significantly from 1.8 × 1016 to 1.7 × 1013 cm-3 as annealing temperature increases. It was found that the TFT performance enhanced significantly, resulting from the improvement in the film quality of the Cu2O active layer: enhancement in the field-effect mobility and the on/off current ratio, and a reduction in the off-state current. Finally, the bottom-gate staggered p-type TFTs using Cu2O annealed at 700 °C showed a field-effect mobility of ˜0.9 cm2/V.s and an on/off current ratio of ˜3.4 × 102.

  13. Effects of Reduced pH on Macoma balthica Larvae from a System with Naturally Fluctuating pH-Dynamics.

    Directory of Open Access Journals (Sweden)

    Anna Jansson

    Full Text Available Ocean acidification is causing severe changes in the inorganic carbon balance of the oceans. The pH conditions predicted for the future oceans are, however, already regularly occurring in the Baltic Sea, and the system might thus work as an analogue for future ocean acidification scenarios. The characteristics of the Baltic Sea with low buffering capacity and large natural pH fluctuations, in combination with multiple other stressors, suggest that OA effects may be severe, but remain largely unexplored. A calcifying species potentially affected by low pH conditions is the bivalve Macoma balthica (L.. We investigated larval survival and development of M. balthica by exposing the larvae to a range of pH levels: 7.2, 7.4, 7.7 and 8.1 during 20 days in order to learn what the effects of reduced pH are on the larval biology and thus also potentially for the population dynamics of this key species. We found that even a slight pH decrease causes significant negative changes during the larval phase, both by slowing growth and by decreasing survival. The growth was slower in all reduced pH treatments compared to the control treatment. The size of 250 µm that is considered indicative to imminent settling in our system was reached by 22% of the larvae grown in control conditions after 20 days, whereas in all reduced pH treatments the size of 250 µm was reached by only 7-14%. The strong impact of ocean acidification on larvae is alarming as slowly growing individuals are exposed to higher predation risk in response to the longer time they are required to spend in the plankton, further decreasing the ecological competence of the species.

  14. Power vacuum tubes handbook

    CERN Document Server

    Whitaker, Jerry


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

  15. A Planck Vacuum Cosmology

    Directory of Open Access Journals (Sweden)

    Daywitt W. C.


    Full Text Available Both the big-bang and the quasi-steady-state cosmologies originate in some type of Planck state. This paper presents a new cosmological theory based on the Planck- vacuum negative-energy state, a state consisting of a degenerate collection of negative- energy Planck particles. A heuristic look at the Einstein field equation provides a con- vincing argument that such a vacuum state could provide a theoretical explanation for the visible universe.

  16. Effect of long-time, elevated-temperature exposures to vacuum and lithium on the properties of a tantalum alloy, T-111 (United States)

    Buzzard, R. J.; Sheffler, K. D.


    The effect of long-term, elevated-temperature vacuum and lithium exposures on the mechanical properties of T-111 (Ta-8W-2Hf) is determined. Exposure conditions were for 1000 hours at 980 or 1315 C, 5000 hours at 1315 C, and a duplex temperature exposure of 1000 hours at 980 C plus 4000 hours at 1040 C. The exposures resulted in reduced tensile and creep strengths of the T-111 in the 900 to 1100 C temperature range where a dynamic strain-age-strengthening mechanism is operative in this alloy. This strength reduction was attributed to the depletion of oxygen from solid solution in this alloy.

  17. Modelling of the effects of conduction band fluctuations caused by nitrogen clustering in GaInNAs materials

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Xiao; Rorison, Judy M. [Department of Electrical and Electronic Engineering, University of Bristol, BS8 1TR (United Kingdom)


    It has been observed experimentally that the band edge photoluminescence of GaInNAs Quantum well (QW) materials is broadened resulting from band-tailing, localised states or conduction band edge fluctuations. In this paper we develop a model for N compositional fluctuations causing conduction band edge fluctuations which localise the electrons into the resulting quantum dots (QDs). The electron dynamics in the QDs and QW states are examined using a rate equation approach and the carrier populations presented as a function of barrier height and temperature. This mechanism could lead to broad gain in GaInAsN QW structures which could be useful for broad band SOAs for optical communications (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  18. Macroalgae may mitigate ocean acidification effects on mussel calcification by increasing pH and its fluctuations

    KAUST Repository

    Wahl, M.


    Ocean acidification (OA) is generally assumed to negatively impact calcification rates of marine organisms. At a local scale however, biological activity of macrophytes may generate pH fluctuations with rates of change that are orders of magnitude larger than the long-term trend predicted for the open ocean. These fluctuations may in turn impact benthic calcifiers in the vicinity. Combining laboratory, mesocosm and field studies, such interactions between OA, the brown alga Fucus vesiculosus, the sea grass Zostera marina and the blue mussel Mytilus edulis were investigated at spatial scales from decimetres to 100s of meters in the western Baltic. Macrophytes increased the overall mean pH of the habitat by up to 0.3 units relative to macrophyte-free, but otherwise similar, habitats and imposed diurnal pH fluctuations with amplitudes ranging from 0.3 to more than 1 pH unit. These amplitudes and their impact on mussel calcification tended to increase with increasing macrophyte biomass to bulk water ratio. At the laboratory and mesocosm scales, biogenic pH fluctuations allowed mussels to maintain calcification even under acidified conditions by shifting most of their calcification activity into the daytime when biogenic fluctuations caused by macrophyte activity offered temporal refuge from OA stress. In natural habitats with a low biomass to water body ratio, the impact of biogenic pH fluctuations on mean calcification rates of M. edulis was less pronounced. Thus, in dense algae or seagrass habitats, macrophytes may mitigate OA impact on mussel calcification by raising mean pH and providing temporal refuge from acidification stress.

  19. Effects of subchronic exposures to concentrated ambient particles (CAPs) in mice. III. Acute and chronic effects of CAPs on heart rate, heart-rate fluctuation, and body temperature. (United States)

    Hwang, Jing-Shiang; Nadziejko, Christine; Chen, Lung Chi


    Normal mice (C57) and mice prone to develop atherosclerosis (ApoE-/-) were implanted with electrocardiograph (EKG), core body temperature, and motion transmitters were exposed daily for 6 h to Tuxedo, NY, concentrated ambient particles (CAPs) for 5 day/wk during the spring and summer of 2003. The series of 5-min EKG monitoring and body-temperature measurements were obtained for each animal in the CAPs and filtered air sham exposure groups. Our hypothesis was that chronic exposure could cause cumulative health effects. We used our recently developed nonparametric method to estimate the daily time periods that mean heart rates (HR), body temperature, and physical activity differed significantly between the CAPs and sham exposed group. CAPs exposure most affected heart rate between 1:30 a.m. and 4:30 a.m. With the response variables being the average heart rate, body temperature, and physical activity, we adopted a two-stage modeling approach to obtain the estimates of chronic and acute effects on the changes of these three response variables. In the first stage, a time-varying model estimated daily crude effects. In the second stage, the true means of the estimated crude effects were modeled with a polynominal function of time for chronic effects, a linear term of daily CAPs exposure concentrations for acute effects, and a random component for unknown noise. A Bayesian framework combined these two stages. There were significant decreasing patterns of HR, body temperature, and physical activity for the ApoE-/- mice over the 5 mo of CAPs exposure, with smaller and nonsignificant changes for the C57 mice. The chronic effect changes of the three response variables for ApoE-/- mice were maximal in the last few weeks. There was also a significant relationship between CAPs exposure concentration and short-term changes of heart rate in ApoE-/- mice during exposure. Response variables were also defined for examining fluctuations of 5-min heart rates within long (i.e., 3-6 h

  20. Temporal and spatial variations in wildlife population fluctuations in Greenland; The effect of climate, environment and man

    DEFF Research Database (Denmark)

    Moshøj, Charlotte Margaret; Forchhammer, Mads C.; Forbes, Valery E.


    fluctuations throughout recordable historical time. The most detailed accounts are found for the species that were harvested or had economical value. While several recent studies from northern latitudes have shown the relative roles of climate, the exogenous and endogenous environment of species and man...... as factors driving species population dynamics, the relative contributions and potential interactions among these factors remains unsolved. In Greenland, these fluctuations in the harvests of individual species are believed to be related to changes in climate, as well as variations in hunting pressure....... The results of this study will model future predictions of wildlife populations under changing climate variables and human hunting pressure....

  1. Effect of a nano-silver coating on the quality of fresh turkey meat during storage after modified atmosphere or vacuum packaging. (United States)

    Deus, D; Kehrenberg, C; Schaudien, D; Klein, G; Krischek, C


    Nano-silver is used in consumer products due to its antibacterial properties. The aim of this study was to evaluate the effect of a nano-silver-coated film on the quality of turkey meat during vacuum-sealed and modified atmosphere packaging up to 12 days of storage. In the first part of the experiment, turkey breasts were packaged using either vacuum packaging or modified atmosphere packages (MAPs) and contained films with or without a nano-silver coating (control film). Parameters such as pH, electrical conductivity, color (lightness L*, redness a*), myoglobin redox forms, thiobarbituric acid-reactive substances (TBARS), biogenic amines (BAs), total viable bacterial counts, Pseudomonas species counts, and Enterobacteriaceae species counts were evaluated on storage days 4, 8, and 12. In the second part of the study, the antimicrobial effect of a nano-silver-coated film on turkey breast was evaluated after inoculation with Escherichia coli (E. coli). Turkey meat packaged with the nano-silver film exhibited lower a* values on days 1 (3.15 ± 0.62), 4 (3.90 ± 0.68), and 8 (4.27 ± 0.76) compared to the packaged meat with the control film (3.41 ± 0.73, 4.35 ± 0.94, 4.85 ± 0.89, respectively), indicating special optical properties of nanoparticles. Concerning the BAs, silver packaged meat showed higher values of tyramine on day 12 (1274 ± 392 ng/g meat) and cadaverine on day 4 (1224 ± 435 ng/g meat) compared to the normal packaged products (647 ± 576 and 508 ± 314 ng/g meat, respectively). MAP meat revealed higher L* and TBARS values and lower microbial counts than the vacuum packaged products on all days. The MAP meat also showed lower a* results on days 4 and 8 and higher metmyoglobin (metMb) values on days 8 and 12 compared to th E: vacuum products. In the inoculation study, the microbial counts of the turkey meat were comparable between the two film types. The study showed that the nano-silver coating did not exhibit any advantageous

  2. Denitrification in the banks of fluctuating rivers: The effects of river stage amplitude, sediment hydraulic conductivity and dispersivity, and ambient groundwater flow (United States)

    Shuai, Pin; Cardenas, M. Bayani; Knappett, Peter S. K.; Bennett, Philip C.; Neilson, Bethany T.


    Hyporheic exchange induced by periodic river fluctuations leads to important biogeochemical processes, particularly nitrogen cycling, in riparian zones (RZs) where chemically distinct surface water and groundwater mix. We developed a two-dimensional coupled flow, reactive transport model to study the role of bank storage induced by river fluctuations on removing river-borne nitrate. Sensitivity analyses were conducted to quantify the effects of river amplitude, sediment hydraulic conductivity and dispersivity, and ambient groundwater flow on nitrate removal rate. The simulations showed that nitrification occurred in the shallower zone adjacent to the bank where oxic river water and groundwater interacted while denitrification occurred deeper into the aquifer and in the riverbed sediments where oxygen was depleted. River fluctuations greatly increased the amount of nitrate being removed; the nitrate removal rate increased as river amplitude increased. Similarly, increasing hydraulic conductivity increased overall nitrate removal since it expanded the denitrifying zone but decreased efficiency. In contrast, increasing sediment dispersivity increased the removal efficiency of nitrate because it promoted mixing between electron acceptors and donors. The presence and direction of ambient groundwater flow had a significant impact on nitrate removal rate when compared to neutral conditions. A losing river showed a larger nitrate removal rate, whereas a gaining river showed a smaller nitrate removal rate. Our results demonstrated that daily river fluctuations created denitrification hot spots within the RZ that would not otherwise exist under naturally neutral or gaining conditions.

  3. In situ preparation of biomimetic thin films and their surface-shielding effect for organisms in high vacuum.

    Directory of Open Access Journals (Sweden)

    Hiroshi Suzuki

    Full Text Available Self-standing biocompatible films have yet to be prepared by physical or chemical vapor deposition assisted by plasma polymerization because gaseous monomers have thus far been used to create only polymer membranes. Using a nongaseous monomer, we previously found a simple fabrication method for a free-standing thin film prepared from solution by plasma polymerization, and a nano-suit made by polyoxyethylene (20 sorbitan monolaurate can render multicellular organisms highly tolerant to high vacuum. Here we report thin films prepared by plasma polymerization from various monomer solutions. The films had a flat surface at the irradiated site and were similar to films produced by vapor deposition of gaseous monomers. However, they also exhibited unique characteristics, such as a pinhole-free surface, transparency, solvent stability, flexibility, and a unique out-of-plane molecular density gradient from the irradiated to the unirradiated surface of the film. Additionally, covering mosquito larvae with the films protected the shape of the organism and kept them alive under the high vacuum conditions in a field emission-scanning electron microscope. Our method will be useful for numerous applications, particularly in the biological sciences.

  4. [Clinical study of the effectiveness of filters in vacuum cleaners for reducing the concentration of dust mites in the household]. (United States)

    Horak, F


    The faeces of the dust mite are the most significant source of allergy for those allergic to the dust mite. During vacuum cleaning, faecal particles are emitted from the cleaner and into the air to form pathological concentrations. The aim of the study was to discover if these extreme concentrations could be prevented by the use of appropriate filters. As the allergen source, dust mite faeces were used. A Miele vacuum cleaner type S424i was used without filter, with S-Class filter, and with Super Air Clean Filter. In the first test 1 g, and in the second test 2 g of dust mite faecal particles were evenly spread and then vacumed up. While using each filter in turn, the expelled air was measured for faecal concentrations. The analysis was performed by counting the number of faecal particles, and determining the content of major allergen Der p I in the expelled air. Without a filter there was a massive concentration of faecal particles in the expelled air. The simple filter Type (S-class-filter) achieved a significant reduction on the emission of allergens. The more complex special filter (Super air clean filter), was able to remove all traces of allergens from the expelled air.

  5. Effect of Ocean Acidification and pH Fluctuations on the Growth and Development of Coralline Algal Recruits, and an Associated Benthic Algal Assemblage.

    Directory of Open Access Journals (Sweden)

    Michael Y Roleda

    Full Text Available Coralline algae are susceptible to the changes in the seawater carbonate system associated with ocean acidification (OA. However, the coastal environments in which corallines grow are subject to large daily pH fluctuations which may affect their responses to OA. Here, we followed the growth and development of the juvenile coralline alga Arthrocardia corymbosa, which had recruited into experimental conditions during a prior experiment, using a novel OA laboratory culture system to simulate the pH fluctuations observed within a kelp forest. Microscopic life history stages are considered more susceptible to environmental stress than adult stages; we compared the responses of newly recruited A. corymbosa to static and fluctuating seawater pH with those of their field-collected parents. Recruits were cultivated for 16 weeks under static pH 8.05 and 7.65, representing ambient and 4× preindustrial pCO2 concentrations, respectively, and two fluctuating pH treatments of daily [Formula: see text] (daytime pH = 8.45, night-time pH = 7.65 and daily [Formula: see text] (daytime pH = 8.05, night-time pH = 7.25. Positive growth rates of new recruits were recorded in all treatments, and were highest under static pH 8.05 and lowest under fluctuating pH 7.65. This pattern was similar to the adults' response, except that adults had zero growth under fluctuating pH 7.65. The % dry weight of MgCO3 in calcite of the juveniles was reduced from 10% at pH 8.05 to 8% at pH 7.65, but there was no effect of pH fluctuation. A wide range of fleshy macroalgae and at least 6 species of benthic diatoms recruited across all experimental treatments, from cryptic spores associated with the adult A. corymbosa. There was no effect of experimental treatment on the growth of the benthic diatoms. On the community level, pH-sensitive species may survive lower pH in the presence of diatoms and fleshy macroalgae, whose high metabolic activity may raise the pH of the local microhabitat.

  6. Effect of Ocean Acidification and pH Fluctuations on the Growth and Development of Coralline Algal Recruits, and an Associated Benthic Algal Assemblage. (United States)

    Roleda, Michael Y; Cornwall, Christopher E; Feng, Yuanyuan; McGraw, Christina M; Smith, Abigail M; Hurd, Catriona L


    Coralline algae are susceptible to the changes in the seawater carbonate system associated with ocean acidification (OA). However, the coastal environments in which corallines grow are subject to large daily pH fluctuations which may affect their responses to OA. Here, we followed the growth and development of the juvenile coralline alga Arthrocardia corymbosa, which had recruited into experimental conditions during a prior experiment, using a novel OA laboratory culture system to simulate the pH fluctuations observed within a kelp forest. Microscopic life history stages are considered more susceptible to environmental stress than adult stages; we compared the responses of newly recruited A. corymbosa to static and fluctuating seawater pH with those of their field-collected parents. Recruits were cultivated for 16 weeks under static pH 8.05 and 7.65, representing ambient and 4× preindustrial pCO2 concentrations, respectively, and two fluctuating pH treatments of daily [Formula: see text] (daytime pH = 8.45, night-time pH = 7.65) and daily [Formula: see text] (daytime pH = 8.05, night-time pH = 7.25). Positive growth rates of new recruits were recorded in all treatments, and were highest under static pH 8.05 and lowest under fluctuating pH 7.65. This pattern was similar to the adults' response, except that adults had zero growth under fluctuating pH 7.65. The % dry weight of MgCO3 in calcite of the juveniles was reduced from 10% at pH 8.05 to 8% at pH 7.65, but there was no effect of pH fluctuation. A wide range of fleshy macroalgae and at least 6 species of benthic diatoms recruited across all experimental treatments, from cryptic spores associated with the adult A. corymbosa. There was no effect of experimental treatment on the growth of the benthic diatoms. On the community level, pH-sensitive species may survive lower pH in the presence of diatoms and fleshy macroalgae, whose high metabolic activity may raise the pH of the local microhabitat.

  7. Effect of directional selection for body size on fluctuating asymmetry in certain morphological traits in Drosophila ananassae. (United States)

    Vishalakshi, C; Singh, B N


    Variation in the subtle differences between the right and left sides of bilateral characters or fluctuating asymmetry (FA) has been considered as an indicator of an organism's ability to cope with genetic and environmental stresses during development. However, due to inconsistency in the results of empirical studies, the relationship between FA and stress has been the subject of intense debate. In this study, we investigated whether stress caused by artificial bidirectional selection for body size has any effect on the levels of FA of different morphological traits in Drosophila ananassae. The realised heritability (h2) was higher in low-line females and high-line males, which suggests an asymmetrical response to selection for body size. Further, the levels of FA were compared across 10 generations of selection in different selection lines in both sexes for sternopleural bristle number, wing length, wing-to-thorax ratio, sex combtooth number and ovariole number. The levels of FA differed significantly among generations and selection lines but did not change markedly with directional selection. However, the levels of FA were higher in the G10 generation (at the end of selection) than G0 (at the start of selection) but lower than the G5 generation in different selection lines, suggesting that the levels of FA are not affected by the inbreeding generated during the course of selection. Also, the levels of FA in the hybrids of high and low lines were signifi cantly lower than the parental selection lines, suggesting that FA is influenced by hybridisation. These results are discussed in the framework of the literature available on FA and its relationship with stress.

  8. Analysis of the effect of the Electron-Beam welding sequence for a fixed manufacturing route using finite element simulations applied to ITER vacuum vessel manufacture

    Energy Technology Data Exchange (ETDEWEB)

    Martín-Menéndez, Cristina, E-mail: [Numerical Analysis Technologies, S.L. Marqués de San Esteban No. 52, 33206 Gijón (Spain); Rodríguez, Eduardo [Department of Mechanical Engineering, University of Oviedo, Campus de Gijón, 33203 Gijón (Spain); Ottolini, Marco [Ansaldo Nucleare S.p.A., Corso Perrone 25, 16152 Genova (Italy); Caixas, Joan [F4E, c/Josep Pla, n.2, Torres Diagonal Litoral, Edificio B3, E-08019 Barcelona (Spain); Guirao, Julio [Numerical Analysis Technologies, S.L. Marqués de San Esteban No. 52, 33206 Gijón (Spain)


    Highlights: • The simulation methodology employed in this paper is able to adapt inside a complex manufacturing route. • The effect of the sequence is lower in a highly constrained assembly than in a lowly constrained one. • The most relevant influence on the distortions is the jigs design, instead of the welding sequence. • The welding distortion analysis should be used as a guidance to design and improve the manufacturing strategy. - Abstract: The ITER Vacuum Vessel Sectors have very tight tolerances and high density of welding. Therefore, prediction and reduction of welding distortion are critical to allow the final assembly with the other Vacuum Vessel Sectors without the production of a full scale prototype. In this paper, the effect of the welding sequence in the distortions inside a fixed manufacturing route and in a highly constrained assembly is studied in the poloidal segment named inboard (PS1). This is one of the four poloidal segments (PS) assembled for the sector. Moreover, some restrictions and limitations in the welding sequence related to the manufacturing process are explained. The results obtained show that the effect of the sequence is lower in a highly constrained assembly than in a low constrained one. A prototype manufactured by AMW consortium (PS1 mock-up) is used in order to validate the finite element method welding simulation employed. The obtained results confirmed that for Electron-Beam welds, both the welding simulation and the mock-up show a low value of distortions.

  9. Effect of ECH on Turbulent Fluctuations During ITER Baseline Scenario-like Discharges on DIII-D (United States)

    Marinoni, A.; Rost, J. C.; Porkolab, M.; Davis, E. M.; Pinsker, R. I.; Burrell, K. H.; DIII-D Team


    Recent experiments on the DIII-D tokamak simulating ITER Baseline Scenario discharges have shown a strong increase in the intensity of low frequency fluctuations during intense electron cyclotron heating (ECH) phases. The torque-free and spatially localized pure electron heating, compared to beam heating, is believed to modify flow shear and fluctuations, resulting in a slightly weaker dependence of stored energy on input power compared to the nominal ITER IPB 98(y,2) scaling. Within 30 ms after turning off ECH power, the phase contrast imaging (PCI) diagnostic detects an increase of the intensity of fluctuations at frequencies higher than 200 kHz, likely due to the prompt response of the electron temperature profile; fluctuations at lower frequency decrease in intensity on a longer time scale, after other equilibrium quantities evolve. Nonlinear gyro-kinetic simulations are in progress and will be compared to PCI measurements via a synthetic diagnostic. Work supported by the US Department of Energy under DE-FG02-94ER54235 and DE-FC02-04ER54698.

  10. The Effect of Electron Cyclotron Heating on Multi-Scale Fluctuations in ITER Baseline Scenario Discharges on DIII-D (United States)

    Maronini, A.; Rost, J. C.; Porkolab, M.; Davis, E. M.; Pinsker, R. I.; Burrell, K. H.; Staebler, G. M.; Grierson, B. A.


    Experiments on DIII-D simulating the ITER Baseline Scenario show that torque-free pure electron heating (ECH) modifies profiles and affects density fluctuations at electron and at ion scales in different ways. The Phase Contrast Imaging diagnostic is used to measure the time evolution of density fluctuations going from mixed beam/ECH to pure beam heating at fixed βN. The intensity of fluctuations at scales between 2 and 5 cm-1 increases promptly after turning off ECH; at larger scales, in contrast, it decreases only after other equilibrium quantities have evolved to a new stationary state. Non-linear gyro-kinetic simulations suggest that the former response is due to ETG modes that also generate a prompt inward particle pinch; the latter is consistent with the dominant ITG modes being weakened by the increased flow shear in the new state. Such fluctuations in ITER might affect fusion performance via modifications to steady-state profiles. Work supported by the US Department of Energy under DE-FG02-94ER54235 and DE-FC02-04ER54698.

  11. Determination of the plasma effective charge from the soft X-ray spectrum and plasma conductivity at the L-2M stellarator after boronization of the vacuum chamber

    Energy Technology Data Exchange (ETDEWEB)

    Meshcheryakov, A. I., E-mail:; Vafin, I. Yu., E-mail: [Russian Academy of Sciences, Prokhorov General Physics Institute (Russian Federation)


    Boronization of the vacuum chamber wall results in a considerable change in the composition of the plasma generated in working pulses of the L-2M stellarator and, accordingly, in the plasma effective charge. The paper presents results of measurements of the plasma effective charge carried out by two methods in the ohmic heating mode: from the data on the plasma conductivity and from the soft X-ray spectrum of plasma emission. Comparison of the values of the plasma effective charge obtained by these two methods makes it possible to determine the conditions in which the two values are in good agreement. Under these conditions, the plasma effective charge can be correctly estimated from spectral measurements.

  12. Effect of process parameters on power requirements of vacuum swing adsorption technology for CO{sub 2} capture from flue gas

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Jun [Department of Chemical Engineering, P.O. Box 36, Monash University, Victoria 3800 (Australia); Webley, Paul A. [Department of Chemical Engineering, P.O. Box 36, Monash University, Victoria 3800 (Australia)], E-mail:; Xiao, Penny [Department of Chemical Engineering, P.O. Box 36, Monash University, Victoria 3800 (Australia)


    This study focuses on the effects of process and operating parameters - feed gas temperature, evacuation pressure and feed concentration - on the performance of carbon dioxide vacuum swing adsorption (CO{sub 2}VSA) processes for CO{sub 2} capture from gas, especially as it affects power consumption. To obtain reliable data on the VSA process, experimental work was conducted on a purposely built three bed CO{sub 2}VSA pilot plant using commercial 13X zeolite. Both 6 step and 9 step cycles were used to determine the influences of temperature, evacuation pressure and feed concentration on process performance (recovery, purity, power and corresponding capture cost). A simple economic model for CO{sub 2} capture was developed and employed herein. Through experiments and analysis, it is found that the feed gas temperature, evacuation pressure and feed concentration have significant effects on power consumption and CO{sub 2} capture cost. Our data demonstrate that the CO{sub 2}VSA process has good recovery (>70%), purity (>90%) and low power cost (4-10 kW/TPDc) when operating with 40 deg. C feed gas provided relatively deep vacuum is used. Enhanced performance is obtained when higher feed gas concentration is fed to the plant, as expected. Our data indicates large potential for application of CO{sub 2}VSA to CO{sub 2} capture from flue gas.

  13. Vacuum induced photoresist outgassing (United States)

    Waterman, Justin; Mbanaso, Chimaobi; Denbeaux, Gregory


    In order to continue the trend toward smaller feature sizes in lithography, new methods of lithography will be needed. A likely method for printing features 32 nm and smaller is extreme ultraviolet (EUV) lithography. EUV allows for features to be printed that are smaller than the current methods can achieve. However, outgassing of the photoresist is a concern for EUV lithography. The outgassed components can lead to contamination of the optics, degrading the reflectivity and hence lowering throughput of the exposure tools. Outgassing due to EUV exposure has been investigated by many groups. However, there were no complete investigations available of vacuum induced outgassing. In this paper, several methods were employed to investigate the outgassing due to vacuum. It was found that the vacuum induced outgassing outgassed a similar number of molecules as the outgassing due to EUV exposure. Furthermore, almost all of the outgassing was completed after about two minutes in vacuum. To mitigate the potential concern of outgassing due to vacuum causing contamination of optics, this work shows that photoresist coated silicon wafers only require about two minutes of pumping prior to insertion near the optics within EUV lithography tools.

  14. Wind fluctuations over the North Sea

    DEFF Research Database (Denmark)

    Vincent, Claire Louise; Pinson, Pierre; Giebel, Gregor


    Climatological patterns in wind speed fluctuations with periods of 1 min to 10 h are analysed using data from a meteorological mast in the Danish North Sea. Fluctuations on these time scales are of particular relevance to the effective management of the power supply from large wind farms. The Hil......Climatological patterns in wind speed fluctuations with periods of 1 min to 10 h are analysed using data from a meteorological mast in the Danish North Sea. Fluctuations on these time scales are of particular relevance to the effective management of the power supply from large wind farms...

  15. On the structure of the physical vacuum and its cosmological consequences (United States)

    Gevorkyan, Ashot


    In the representation of the quantum field theory (QFT), the physical vacuum is the infinite set of various fluctuating virtual energetic particles and fields in the R4 space-time of Minkowski. Recall that the experimental facts such as the Lamb shift between of 2S1/2 and 2P1/2 energy levels of the hydrogen atom, Casimir and Unruh effects etc., are important proofs of QFT predictions. In conjunction with this a natural question arises, namely; what is the structure of the physical vacuum (PV) when there are not the external influences on the vacuum? It is obvious, that for study of many nontrivial problems of QV we need to develop a nonperturbative QFT [1]. In this work we consider the propagation of electromagnetic fields in free PV in the framework of Langevin-Maxwell type stochastic differential equations. For the sake of simplicity we have assumed, that the random sources of energetic particles and fields satisfy the correlation conditions of the white noise. The last allows in particular derive the equation for distribution of vacuum fields and, respectively to construct nonperturbative closed theory for the physical vacuum taking into account the influence of the external electromagnetic fields. As it is proved, in the limit of a statistical equilibrium the physical vacuum after some simplifications is described in the 6D space-time, where 4D is the Minkowski space-time, while the additional 2D is the compact topological space in which the physical vacuum is quantized. In other words, the PV without any external influence has a structure. It is shown, that at the absence of the external fields the integral representation for the refractive indices, as one would expect are identically equal to units. When the physical vacuum is under the influence of the external electromagnetic fields, the quantized states are deformed that leads to changes of refractive indices. The last indicates the existence of a new mechanism of the photon-photon scattering which differs

  16. Fuel property and fuel temperature effects on internal nozzle flow, atomization and cyclic spray fluctuations of a direct injection spark ignition–injector


    Zigan, Lars; Shi, Jun-Mei; Krotow, Ivan; Schmitz, Ingo; Wensing, Michael; Leipertz, Alfred


    The effect of fuel properties and fuel temperature on the behaviour of the internal nozzle flow, atomization and cyclic spray fluctuations is examined for a three-hole direct injection spark ignition injector by combining numerical simulation of the nozzle flow with macroscopic and microscopic spray visualization techniques. A dominant influence of the liquid fuel viscosity on the highly unsteady, cavitating nozzle flow and spray formation was observed. A reduced viscosity (or larger Reynolds...

  17. Diurnal fluctuations of electrical conductivity in a pre-alpine river: Effects of photosynthesis and groundwater exchange (United States)

    Hayashi, Masaki; Vogt, Tobias; Mächler, Lars; Schirmer, Mario


    SummaryDiurnal fluctuations of dissolved oxygen (DO) concentration and pH due to photosynthesis and respiration are commonly observed in rivers that support periphyton growth. Diurnal fluctuations of electrical conductivity (EC) in connection with photosynthesis have also been reported, but mostly in small, first-order streams or in streams fed by karst springs. The objective of this study is to examine the diurnal EC fluctuations in a large river and understand biological, chemical, and hydrological processes controlling the fluctuations, using long-term archived data, focused field monitoring, and laboratory experiments. The study was conducted in the Thur River draining a 1700 km2 catchment in northeastern Switzerland. The river showed distinct diurnal fluctuations of DO and pH caused by photosynthesis and respiration except during December and part of January. Fluctuations were frequently disrupted by spates with peak discharge exceeding 150 m3 s-1, which removed biofilm and periphyton. During a period of low flow (12 m3 s-1) and clear sky, photosynthesis released O2 and consumed CO2 in water during the daytime, thereby increasing pH and the saturation index of calcite. This caused calcite to precipitate and removed Ca and alkalinity from water, and reduced EC. Laboratory experiments showed that the increase in pH and the saturation index alone cannot cause calcite precipitation without the presence of periphyton. It is likely that the precipitation occurs in the microenvironment in the close vicinity of photosynthesizing cells, where the pH and the calcite saturation index are much higher than in the bulk river water. Calcite precipitation stopped during the nighttime despite supersaturated conditions, and EC gradually increased presumably due to the input of Ca and alkalinity by groundwater exchange. The study clearly showed that photosynthesis and calcite precipitation have a strong influence on the chemistry of the large river, and pointed out the need for

  18. Quantum principle of sensing gravitational waves: From the zero-point fluctuations to the cosmological stochastic background of spacetime (United States)

    Quiñones, Diego A.; Oniga, Teodora; Varcoe, Benjamin T. H.; Wang, Charles H.-T.


    We carry out a theoretical investigation on the collective dynamics of an ensemble of correlated atoms, subject to both vacuum fluctuations of spacetime and stochastic gravitational waves. A general approach is taken with the derivation of a quantum master equation capable of describing arbitrary confined nonrelativistic matter systems in an open quantum gravitational environment. It enables us to relate the spectral function for gravitational waves and the distribution function for quantum gravitational fluctuations and to indeed introduce a new spectral function for the zero-point fluctuations of spacetime. The formulation is applied to two-level identical bosonic atoms in an off-resonant high-Q cavity that effectively inhibits undesirable electromagnetic delays, leading to a gravitational transition mechanism through certain quadrupole moment operators. The overall relaxation rate before reaching equilibrium is found to generally scale collectively with the number N of atoms. However, we are also able to identify certain states of which the decay and excitation rates with stochastic gravitational waves and vacuum spacetime fluctuations amplify more significantly with a factor of N2. Using such favorable states as a means of measuring both conventional stochastic gravitational waves and novel zero-point spacetime fluctuations, we determine the theoretical lower bounds for the respective spectral functions. Finally, we discuss the implications of our findings on future observations of gravitational waves of a wider spectral window than currently accessible. Especially, the possible sensing of the zero-point fluctuations of spacetime could provide an opportunity to generate initial evidence and further guidance of quantum gravity.

  19. Improved Aerogel Vacuum Thermal Insulation (United States)

    Ruemmele, Warren P.; Bue, Grant C.


    An improved design concept for aerogel vacuum thermal-insulation panels calls for multiple layers of aerogel sandwiched between layers of aluminized Mylar (or equivalent) poly(ethylene terephthalate), as depicted in the figure. This concept is applicable to both the rigid (brick) form and the flexible (blanket) form of aerogel vacuum thermal-insulation panels. Heretofore, the fabrication of a typical aerogel vacuum insulating panel has involved encapsulation of a single layer of aerogel in poly(ethylene terephthalate) and pumping of gases out of the aerogel-filled volume. A multilayer panel according to the improved design concept is fabricated in basically the same way: Multiple alternating layers of aerogel and aluminized poly(ethylene terephthalate) are assembled, then encapsulated in an outer layer of poly(ethylene terephthalate), and then the volume containing the multilayer structure is evacuated as in the single-layer case. The multilayer concept makes it possible to reduce effective thermal conductivity of a panel below that of a comparable single-layer panel, without adding weight or incurring other performance penalties. Implementation of the multilayer concept is simple and relatively inexpensive, involving only a few additional fabrication steps to assemble the multiple layers prior to evacuation. For a panel of the blanket type, the multilayer concept, affords the additional advantage of reduced stiffness.

  20. Improving Vacuum Cleaners (United States)


    Under a Space Act Agreement between the Kirby company and Lewis Research Center, NASA technology was applied to a commercial vacuum cleaner product line. Kirby engineers were interested in advanced operational concepts, such as particle flow behavior and vibration, critical factors to improve vacuum cleaner performance. An evaluation of the company 1994 home care system, the Kirby G4, led to the refinement of the new G5 and future models. Under the cooperative agreement, Kirby had access to Lewis' holography equipment, which added insight into how long a vacuum cleaner fan would perform, as well as advanced computer software that can simulate the flow of air through fans. The collaboration resulted in several successes including fan blade redesign and continuing dialogue on how to improve air-flow traits in various nozzle designs.

  1. The effect of gap fluctuations on interacting and non-interacting polarization for nano-superconducting grains in electron- and hole-doped cuprates (United States)

    Afzali, R.; Alizadeh, A.


    The behavior of non-interacting and interacting polarization under influence of fluctuations of the superconducting gap with D-wave symmetry and under consideration of the gap dependence on nano- grain size is obtained in terms of the frequency, temperature and the size at zero and finite temperatures for rectangular cuprate nano-superconducting grains. By using Eliashberg equations and applying the relations of the fermionic dispersion for the hole-doped and electron-doped cuprates, we numerically compute the real part of size-dependent polarization for both types of cuprates. We show that the peak of real part of polarization moves to higher frequency by including the additional fluctuating part of gap (or the nano-size effect). Also, we obtain the temperatures for different frequencies, in which the effect of gap fluctuations fades. In the case of size-dependent gap, there is a critical frequency; for frequencies lower (higher) than the critical frequency, the nano-effect weakens (improves) the superconducting state. Moreover, it is concluded that the real part of polarization for hole- doped cuprates in terms of the grain size has more significant amount in comparison with electron-doped ones.

  2. Effect of liner design, pulsator setting, and vacuum level on bovine teat tissue changes and milking characteristics as measured by ultrasonography

    Directory of Open Access Journals (Sweden)

    Gleeson David E


    Full Text Available Friesian-type dairy cows were milked with different machine settings to determine the effect of these settings on teat tissue reaction and on milking characteristics. Three teat-cup liner designs were used with varying upper barrel dimensions (wide-bore WB = 31.6 mm; narrow-bore NB = 21.0 mm; narrow-bore NB1 = 25.0 mm. These liners were tested with alternate and simultaneous pulsation patterns, pulsator ratios (60:40 and 67:33 and three system vacuum levels (40, 44 and 50 kPa. Teat tissue was measured using ultrasonography, before milking and directly after milking. The measurements recorded were teat canal length (TCL, teat diameter (TD, cistern diameter (CD and teat wall thickness (TWT. Teat tissue changes were similar with a system vacuum level of either 50 kPa (mid-level or 40 kPa (low-level. Widening the liner upper barrel bore dimension from 21.0 mm (P

  3. Vacuum Arc Ion Sources

    CERN Document Server

    Brown, I.


    The vacuum arc ion source has evolved into a more or less standard laboratory tool for the production of high-current beams of metal ions, and is now used in a number of different embodiments at many laboratories around the world. Applications include primarily ion implantation for material surface modification research, and good performance has been obtained for the injection of high-current beams of heavy-metal ions, in particular uranium, into particle accelerators. As the use of the source has grown, so also have the operational characteristics been improved in a variety of different ways. Here we review the principles, design, and performance of vacuum arc ion sources.

  4. Baryogenesis in false vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Hamada, Yuta [KEK Theory Center, IPNS, KEK, Tsukuba, Ibaraki (Japan); Yamada, Masatoshi [Kanazawa University, Institute for Theoretical Physics, Kanazawa (Japan)


    The null result in the LHC may indicate that the standard model is not drastically modified up to very high scales, such as the GUT/string scale. Having this in the mind, we suggest a novel leptogenesis scenario realized in the false vacuum of the Higgs field. If the Higgs field develops a large vacuum expectation value in the early universe, a lepton number violating process is enhanced, which we use for baryogenesis. To demonstrate the scenario, several models are discussed. For example, we show that the observed baryon asymmetry is successfully generated in the standard model with higher-dimensional operators. (orig.)

  5. Handbook of vacuum physics

    CERN Document Server


    Handbook of Vacuum Physics, Volume 3: Technology is a handbook of vacuum physics, with emphasis on the properties of miscellaneous materials such as mica, oils, greases, waxes, and rubber. Accurate modern tables of physical constants, properties of materials, laboratory techniques, and properties of commercial pumps, gauges, and leak detectors are presented. This volume is comprised of 12 chapters and begins with a discussion on pump oils, divided into rotary pump oils and vapor pump oils. The next chapter deals with the properties and applications of greases, including outgassing and vapor pr

  6. Host plant pubescence: Effect on silverleaf whitefly, Bemisia argentifolii, fourth instar and pharate adult dimensions and ecdysteroid titer fluctuations

    Directory of Open Access Journals (Sweden)

    Dale B. Gelman


    Full Text Available The ability to generate physiologically synchronous groups of insects is vital to the performance of investigations designed to test insect responses to intrinsic and extrinsic stimuli. During a given instar, the silverleaf whitefly, Bemisia argentifolii, increase in depth but not in length or width. A staging system to identify physiologically synchronous 4th instar and pharate adult silverleaf whiteflies based on increasing body depth and the development of the adult eye has been described previously. This study determined the effect of host plant identity on ecdysteroid fluctuations during the 4th instar and pharate adult stages, and on the depth, length and width dimensions of 4th instar/pharate adult whiteflies. When grown on the pubescent-leafed green bean, tomato and poinsettia plants, these stages were significantly shorter and narrower, but attained greater depth than when grown on the glabrous-leafed cotton, collard and sweet potato plants. Thus, leaf pubescence is associated with reduced length and width dimensions, but increased depth dimensions in 4th instars and pharate adults. For all host plants, nymphal ecdysteroid titers peaked just prior to the initiation of adult development. However, when reared on pubescent-leafed plants, the initiation of adult development typically occurred in nymphs that had attained a depth of 0.2 to 0.25 mm (Stage 3 - 4. When reared on glabrous-leafed plants, the initiation of adult development typically occurred earlier, in nymphs that had attained a depth of only 0.15-0.18 mm (Stage 2 Old - early 3. Therefore, based on ecdysteroid concentration, it appears that Stage-2, -3 and -4/5 nymphs reared on pubescent-leafed plants are physiologically equivalent to Stage-1, -2 Young and -2 Old/3, respectively, nymphs reared on glabrous-leafed plants. The host plant affected the width but not the height of the nymphal-adult premolt ecdysteroid peak. However, leaf pubescence was not the determining factor. Thus


    Directory of Open Access Journals (Sweden)

    Hamudu Rukangantambara


    Full Text Available Since 1980, wetland s in Rwanda have been considered as important areas for agriculture intensification through improving food security and incomes to the farmers. However, changes in the soil nutrient status due to repeatedly wetting and drying phenomena may considerably affect soil fertility status thus leading to low crop productivity of the wetlands. This has consequently created fear to the wetland users especially the local farmers, extension workers and agronomists. The comparative study was conducted to assess the effect of drained and irrigated phenomena at Mamba, Rwasave and Rugeramigozi marshlands on soil fertility change under rice growing. 24 samples were taken with 12 samples under drained and 12 under irrigated areas. The samples were collected randomly from top soil ( 0- 20 cm. The following parameters were quantified; soil pH( H 2O in soil water suspension with ratio 1:2.5; Al exchangeable( 1N Kcl, organic carbon( walkely and black method in Sumner method modified (1984, Total nitrogen kjeldahl (TNK in Bremner modified method, available phosphorus ( bray 1. Bases exchangeable with 1 N ammonium acetate following AAS and CEC and available Fe, Zn, Cu and Mn (DTDA diethylenetriaminepentaacetic acid. Data analyses were processed with GEN STAT version 3. The results showed that the fluctuation of wet and dry water have significantly affected soil fertility status at p= 0,05. The phosphorus and potassium are in the low levels of deficiency 2.32 ppm and 47.72 ppm in irrigated area while crop requirement nutrients are 20 ppm and 200 ppm respectively. And Al is in toxic level conditions, 27.5% in drained area while rice tolerance is 20%. Fe was 641.51 ppm in irrigated area while requirement narrowed to 300 ppm. As conclusion, the soil fertility is low and toxic which constitutes a limitation. The wetland soil in Rwanda should offer opportunities for paddy growing ( rice, etc, if soil fertility factors would be amended by lime for its

  8. Systems-level modeling the effects of arsenic exposure with sequential pulsed and fluctuating patterns for tilapia and freshwater clam

    Energy Technology Data Exchange (ETDEWEB)

    Chen, W.-Y. [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Tsai, J.-W. [Institute of Ecology and Evolutionary Ecology, China Medical University, Taichung 40402, Taiwan (China); Ju, Y.-R. [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Liao, C.-M., E-mail: [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei 10617, Taiwan (China)


    The purpose of this paper was to use quantitative systems-level approach employing biotic ligand model based threshold damage model to examine physiological responses of tilapia and freshwater clam to sequential pulsed and fluctuating arsenic concentrations. We tested present model and triggering mechanisms by carrying out a series of modeling experiments where we used periodic pulses and sine-wave as featured exposures. Our results indicate that changes in the dominant frequencies and pulse timing can shift the safe rate distributions for tilapia, but not for that of freshwater clam. We found that tilapia increase bioenergetic costs to maintain the acclimation during pulsed and sine-wave exposures. Our ability to predict the consequences of physiological variation under time-varying exposure patterns has also implications for optimizing species growing, cultivation strategies, and risk assessment in realistic situations. - Systems-level modeling the pulsed and fluctuating arsenic exposures.

  9. Effects of long-term population fluctuations in a top predator on invertebrate community composition in Alpine ponds


    Wissinger, Scott; Whiteman, Howard; Denoël, Mathieu


    At our remote study site in central Colorado, the population size of tiger salamanders (Ambystoma tigrinum nebulosum) has fluctuated cyclically over the past 20 years from fewer than 100 to over 5000 individuals. Comparative data between ponds with and without salamanders, and experimental studies suggest that this species is a keystone predator on benthic and planktonic prey communities. Here we present long-term community data that reveal taxon- and habitat-specific correlations in the popu...

  10. Modeling fluctuations in scattered waves

    CERN Document Server

    Jakeman, E


    Fluctuations in scattered waves limit the performance of imaging and remote sensing systems that operate on all wavelengths of the electromagnetic spectrum. To better understand these fluctuations, Modeling Fluctuations in Scattered Waves provides a practical guide to the phenomenology, mathematics, and simulation of non-Gaussian noise models and discusses how they can be used to characterize the statistics of scattered waves.Through their discussion of mathematical models, the authors demonstrate the development of new sensing techniques as well as offer intelligent choices that can be made for system analysis. Using experimental results and numerical simulation, the book illustrates the properties and applications of these models. The first two chapters introduce statistical tools and the properties of Gaussian noise, including results on phase statistics. The following chapters describe Gaussian processes and the random walk model, address multiple scattering effects and propagation through an extended med...

  11. High-frequency fluctuation measurements by far-infrared laser Faraday-effect polarimetry-interferometry and forward scattering system on MST. (United States)

    Ding, W X; Lin, L; Duff, J R; Brower, D L


    Magnetic fluctuation-induced transport driven by global tearing modes has been measured by Faraday-effect polarimetry and interferometry (phase measurements) in the MST reversed field pinch. However, the role of small-scale broadband magnetic and density turbulence in transport remains unknown. In order to investigate broadband magnetic turbulence, we plan to upgrade the existing detector system by using planar-diode fundamental waveguide mixers optimized for high sensitivity. Initial tests indicate these mixers have ×10 sensitivity improvement compared to currently employed corner-cube Schottky-diode mixers and ×5 lower noise. Compact mixer design will allow us to resolve the wavenumbers up to k ∼ 1-2 cm(-1) for beam width w = 1.5 cm and 15 cm(-1) for beam width w = 2 mm. The system can also be used to measure the scattered signal (amplitude measurement) induced by both plasma density and magnetic fluctuations.

  12. Technology handbook of vacuum physics

    CERN Document Server

    Beck, A H


    Handbook of Vacuum Physics, Volume 3: Technology is part of a series of publications that presents articles featuring the whole spectrum of vacuum physics. This particular volume presents materials that deal with technology concerns in vacuum mechanics. The first material talks about the utilization of ceramic materials in the construction of vacuum devices. The next paper details the application of vacuum physics in soldering and brazing process. The last article deals with the utilization of vacuum technology in high frequency heating. The book will be of great use to professionals involved

  13. Casimir effect in the rainbow Einstein's universe (United States)

    Bezerra, V. B.; Mota, H. F.; Muniz, C. R.


    In the present paper we investigate the effects caused by the modification of the dispersion relation obtained by solving the Klein-Gordon equation in the closed Einstein's universe in the context of rainbow's gravity models. Thus, we analyse how the quantum vacuum fluctuations of the scalar field are modified when compared with the results obtained in the usual General Relativity scenario. The regularization, and consequently the renormalization, of the vacuum energy is performed adopting the Epstein-Hurwitz and Riemann's zeta functions.

  14. LEP Vacuum Chamber

    CERN Multimedia


    This is a cut-out of a LEP vacuum chamber for dipole magnets showing the beam channel and the pumping channel with the getter (NEG) strip and its insulating supports. A water pipe connected to the cooling channel can also be seen at the back.The lead radiation shield lining is also shown. See also 8305563X.

  15. The vacuum strikes back

    CERN Multimedia


    "Modern physics has shown that the vacuum, previously thought of as a stated of total nothingness, is really a seething background of virtual particles springing in and out of eixstence until they can seize enough energy to materialize as "real" particles." (1,5 page)

  16. LEP vacuum chamber, prototype

    CERN Multimedia

    CERN PhotoLab


    Final prototype for the LEP vacuum chamber, see 8305170 for more details. Here we see the strips of the NEG pump, providing "distributed pumping". The strips are made from a Zr-Ti-Fe alloy. By passing an electrical current, they were heated to 700 deg C.

  17. ISR vacuum system

    CERN Multimedia

    CERN PhotoLab


    Some of the most important components of the vacuum system are shown. At the left, the rectangular box is a sputter-ion pump inside its bake-out oven. The assembly in the centre includes a sector valve, three roughing valves, a turbomolecular pump, a rotary backing pump and auxiliary equipment. At the right, the small elbow houses a Bayard-

  18. On vacuum-insulated thermal storage

    Energy Technology Data Exchange (ETDEWEB)

    Fuchs, Benjamin [Georg-Simon-Ohm Univ. of Applied Sciences, Nuernberg (Germany); Technische Univ. Muenchen (Germany). Inst. of Resource and Energy Technology; Hofbeck, Klaus [Georg-Simon-Ohm Univ. of Applied Sciences, Nuernberg (Germany)


    Nowadays, the insulation for thermal energy storage (TES) is not as good as it should be. One reason for this is the higher investment cost for better insulation. Nevertheless, most of the recent studies show that the thermal losses of long-term storage have been underestimated. Therefore, recent research studies have focused on vacuum-insulated thermal storage. There are two common concepts with regard to the use of vacuum insulation for thermal storage. On the one hand, the Center for Applied Energy Research (ZAE) in Munich uses an evacuated double vessel filled with pearlite. On the other hand, the Ohm University uses vacuum insulation panels (VIP). Both the insulation concepts are based on the Knudsen effect. Thus, the thermal conductivity is lowered by a factor of 6-10, when compared with the conventional insulation materials, such as EPS, XPS, or mineral wool. Both the concepts are adoptions of the existing insulation applications. The filled double vessel tank is already being used for cryogenic storage for liquid gases. Furthermore, VIPs are being used to insulate passive houses. However, the use of vacuum insulation for thermal energy storage causes different problems due to higher temperatures and moisture. Nevertheless, vacuum insulations are a promising solution for small thermal long-tenn storage. This study presents the first state-of-the-art review on vacuum-insulated thermal tanks.

  19. Particle density fluctuations

    Energy Technology Data Exchange (ETDEWEB)

    Aggarwal, M.M.; Ahammed, Z.; Angelis, A.L.S.; Antonenko, V.; Arefiev, V.; Astakhov, V.; Avdeitchikov, V.; Awes, T.C.; Baba, P.V.K.S.; Badyal, S.K.; Bathe, S.; Batiounia, B.; Bernier, T.; Bhalla, K.B.; Bhatia, V.S.; Blume, C.; Bucher, D.; Buesching, H.; Carlen, L.; Chattopadhyay, S.; Das, A.C.; Decowski, M.P.; Donni, P.; Dubey, A.K.; Dutta Majumdar, M.R.; Enosawa, K.; Fokin, S.; Frolov, V.; Ganti, M.S.; Garpman, S.; Gavrishcuk, O.; Geurts, F.J.M.; Glasow, R.; Guskov, B.; Gustafsson, H.A.; Gutbrod, H.H.; Hrivnacova, I.; Ippolitov, M.; Kalechofsky, H.; Kamermans, R.; Karadjev, K.; Karpio, K.; Kolb, B.W.; Kosarev, I.; Koutcheryaev, I.; Kugler, A.; Kulinich, P.; Kurata, M.; Lebedev, A.; Loehner, H.; Mahapatra, D.P.; Manko, V.; Martin, M.; Miake, Y.; Mishra, G.C.; Mohanty, B.; Morrison, D.; Mukhopadhayay, D.S.; Naef, H.; Nandi, B.K.; Nayak, S.K.; Nayak, T.K.; Nianine, A.; Nikitine, V.; Nikolaev, S.; Nishimura, S.; Nomokov, P.; Petracek, V.; Plasil, F.; Purschke, M.L.; Rak, J.; Raniwala, R.; Raniwala, S.; Rao, N.K.; Retiere, F.; Reygers, K.; Roland, G.; Rosselet, L.; Roufanov, I.; Rubio, J.M.; Sambyal, S.S.; Santo, R.; Sato, S.; Schlagheck, H.; Schmidt, H.-R.; Schutz, Y.; Shabratova, G.; Sibiriak, I.; Siemiarczuk, T.; Sinha, B.C.; Slavine, N.; Soederstroem, K.; Sood, G.; Soerensen, S.P.; Stankus, P.; Steinberg, P.; Stenlund, E.; Sumbera, M.; Svensson, T.; Trivedi, M.D.; Tsvetkov, A.; Tykarski, L.; Urbahn, J.; Eijinhoven, N. van; Niewenhuizen, G.J. van; Vinogradov, A.; Viyogi, Y.P.; Vodopianov, A.; Voeroes, S.; Wyslouch, B.; Young, G.R


    Event-by-event fluctuations in the multiplicities of charged particles and photons at SPS energies are discussed. Fluctuations are studied by controlling the centrality of the reaction and rapidity acceptance of the detectors. Results are also presented on the event-by-event study of correlations between the multiplicity of charged particles and photons to search for DCC-like signals.

  20. Particle density fluctuations

    CERN Document Server

    Mohanty, Bedangadas; Ahammed, Z.; Angelis, A.L.S.; Antonenko, V.; Arefev, V.; Astakhov, V.; Avdeitchikov, V.; Awes, T.C.; Baba, P.V.K.S.; Badyal, S.K.; Bathe, S.; Batiounia, B.; Bernier, T.; Bhalla, K.B.; Bhatia, V.S.; Blume, C.; Bucher, D.; Busching, H.; Carlen, L.; Chattopadhyay, S.; Das, A.C.; Decowski, M.P.; Donni, P.; Dubey, A.K.; Dutta Majumdar, M.R.; Enosawa, K.; Fokin, S.; Frolov, V.; Ganti, M.S.; Garpman, S.; Gavrishchuk, O.; Geurts, F.J.M.; Glasow, R.; Guskov, B.; Gustafsson, H.A.; Gutbrod, H.H.; Hrivnacova, I.; Ippolitov, M.; Kalechofsky, H.; Kamermans, R.; Karadjev, K.; Karpio, K.; Kolb, B.W.; Kosarev, I.; Koutcheryaev, I.; Kugler, A.; Kulinich, P.; Kurata, M.; Lebedev, A.; Lohne, H.; Mahapatra, D.P.; Manko, V.; Martin, M.; Miake, Y.; Mishra, G.C.; Morrison, D.; Mukhopadhyay, D.S.; Naef, H.; Nandi, B.K.; Nayak, S.K.; Nayak, T.K.; Nianine, A.; Nikitine, V.; Nikolaev, S.; Nishimura, S.; Nomokov, P.; Nystrand, J.; Oskarsson, A.; Otterlund, I.; Phatak, S.C.; Pavliouk, S.; Peitzmann, T.; Petracek, V.; Plasil, F.; Purschke, M.L.; Rak, J.; Raniwala, R.; Raniwala, S.; Rao, N.K.; Retiere, F.; Reygers, K.; Roland, G.; Rosselet, L.; Roufanov, I.; Rubio, J.M.; Sambyal, S.S.; Santo, R.; Sato, S.; Schlagheck, H.; Schmidt, H.R.; Schutz, Y.; Shabratova, G.; Sibiriak, I.; Siemiarczuk, T.; Sinha, B.C.; Slavine, N.; Soderstrom, K.; Sood, G.; Sorensen, S.P.; Stankus, P.; Stefanek, G.; Steinberg, P.; Stenlund, E.; Sumbera, M.; Svensson, T.; Trivedi, M.D.; Tsvetkov, A.; Tykarski, L.; Urbahn, J.; van Eijndhoven, N.; van Nieuwenhuizen, G.J.; Vinogradov, A.; Viyogi, Y.P.; Vodopianov, A.S.; Voros, S.; Wyslouch, B.; Young, G.R.; Mohanty, Bedangadas


    Event-by-event fluctuations in the multiplicities of charged particles and photons at SPS energies are discussed. Fluctuations are studied by controlling the centrality of the reaction and rapidity acceptance of the detectors. Results are also presented on the event-by-event study of correlations between the multiplicity of charged particles and photons to search for DCC-like signals.

  1. Annealing effect on the particle size and chemical composition of activated carbon obtained from vacuum furnace of teak sawdust

    Energy Technology Data Exchange (ETDEWEB)

    Armynah, B., E-mail:; Tahir, D., E-mail:; Jaya, N., E-mail: [Department of Physics, Hasanuddin University, Makassar 90245 (Indonesia)


    Activated carbon was produced from sawdust by using physical method in a high temperature vacuum furnace without additional chemical. Fast pyrolysis process was carried out prior in fluidized a bed furnace to produce char before activation process. Experiments were conducted to investigate the influence of various process parameters such as particle size, activation temperature and activation time on the quality of the activated carbon. In addition, the chemical composition studies were done by using x-ray fluorescence (XRF) spectroscopy. The crystallite sizes were calculated by using Scherer equation based on x-ray diffraction (XRD) spectroscopy data. The pyrolysis temperature and time were varied from 600°C to 900°C and from 3 hours to 6 hours, respectively. The particle size of activated carbon was increase with increasing temperature. The composition and crystallite size of the prepared activated carbon was compared with the non-activated carbon. The results indicated that the teak sawdust carbon could be employed as a low cost alternative to produce commercial activated carbon.

  2. Effects of vacuum heat treatment on the photoelectric work function and surface morphology of multilayered silver–metal electrical contacts

    Energy Technology Data Exchange (ETDEWEB)

    Akbi, Mohamed, E-mail: [Laboratoire “Arc Electrique et Plasmas Thermiques”, CNRS, UPRES-A 6069, 24, Avenue des Landais, F-63177 Aubière Cedex (France); Department of Physics, Faculty of Sciences, University of Boumerdes (UMBB), Independence Avenue, 35000 Boumerdes (Algeria); Bouchou, Aïssa [Faculty of Physics, University of Algiers (USTHB), B.P. 32, El-Alia, Bab-Ezzouar, 16111 Algiers (Algeria); Zouache, Noureddine [Laboratoire “Arc Electrique et Plasmas Thermiques”, CNRS, UPRES-A 6069, 24, Avenue des Landais, F-63177 Aubière Cedex (France)


    Contact materials used for electrical breakers are often made with silver alloys. Mechanical and thermodynamical properties as well as electron emission of such complicated alloys present a lack of reliable and accurate experimental data. This paper deals mainly with electron work function (EWF) measurements about silver–metal (Ag–Me) electrical contacts (Ag–Ni (60/40) and Ag–W (50/50)), before and after surface heat treatments at 513 K–873 K, under UHV conditions (residual gas pressure of 1.4 × 10{sup −7} mbar). The electron work function (EWF) of silver alloyed contacts was measured photoelectrically, using both Fowler's method of isothermal curves and linearized Fowler plots. An interesting fact brought to light by this investigation is that after vacuum heat treatments, the diffusion and/or evaporation phenomena, affecting the atomic composition of the alloy surface, somehow confine the EWF of the silver–nickel alloy, Φ(Ag–Ni), determined at room temperature in interval]Φ(Ag), Φ(Ni) [=] 4.26 eV, 4.51 eV[. Surface analysis of two specimens before and after heating showed a significant increase of tungsten atomic proportion on the contact surface for Ag–W contacts after VH treatments. A multilayer model, taking into account the strong intergranular and volume segregation gives a good interpretation of the obtained results.

  3. Mechanism of flash vacuum pyrolysis of phenyl propargyl ether. Intramolecular deuterium kinetic isotope effect on claisen rearrangement

    Energy Technology Data Exchange (ETDEWEB)

    Al-Sader, B.H.; Al-Fekri, D.M.


    NMR analyses were performed on the reaction products obtained from the flash vacuum pyrolysis(FVP) of phenyl ..gamma..-deuteropropargyl ether(I) and 2-deuterophenyl propargyl ether(II) to ascertain the reaction mechanism. The FVP was carried out at 460/sup 0/C and 0.02 Torr. The NMR spectrum of undeuterated 2-indanone in carbon tetrachloride displayed peaks at delta 7.15 (singlet, aromatic hydrogen's) and 3.25 (singlet, nonaromatic hydrogen's) and with an integration constant of 1.00 : 1.00, while the NMR spectrum of the deuterated 2-indanone derived from I produced an aromatic protons/nonaromatic protons ratio of 1.30 : 1.00. The NMR analyses of the reaction products from FVP of II indicate that at the rate-determining transition state the oxygen-propargylic (..cap alpha.. carbon) bond is stretched in advance of any significant bond formation between the acetylenic carbon (..gamma.. carbon), the Claisen type rearrangement was classified as a nonsynchronous process and the proposed mechanism agrees with previous studies.

  4. Quantum Ground States as Equilibrium Particle-Vacuum Interaction States

    CERN Document Server

    Puthoff, Harold E


    A remarkable feature of atomic ground states is that they are observed to be radiationless in nature, despite (from a classical viewpoint) typically involving charged particles in accelerated motions. The simple hydrogen atom is a case in point. This universal groundstate characteristic is shown to derive from particle-vacuum interactions in which a dynamic equilibrium is established between radiation emission due to particle acceleration, and compensatory absorption from the zero-point fluctuations of the vacuum electromagnetic field. The result is a net radiationless ground state. This principle constitutes an overarching constraint that delineates an important feature of quantum ground states.

  5. Density of Vacuum-Like Plasma and Hubble Constant (United States)

    Obukhov, Ilya A.


    The model in which expansion of the Universe leads to a generation of non-equilibrium vacuum-like electron-positron plasma is proposed and researched. The formulas that relate the Hubble's constant with the concentration of plasma particles and the cosmological constant are obtained. The collective properties of vacuum-like plasma are investigated. It is shown, that the coefficient of a two-photon annihilation in such plasma is nine times less than for the free particles. A simple formula for dark energy density as a function of electron mass and charge is obtained. It was demonstrated that acceleration of plasma's chemical potential fluctuations flow proportional of dark energy density.

  6. Vacuum polarization energy for general backgrounds in one space dimension

    Directory of Open Access Journals (Sweden)

    H. Weigel


    Full Text Available For field theories in one time and one space dimensions we propose an efficient method to compute the vacuum polarization energy of static field configurations that do not allow a decomposition into symmetric and anti-symmetric channels. The method also applies to scenarios in which the masses of the quantum fluctuations at positive and negative spatial infinity are different. As an example we compute the vacuum polarization energy of the kink soliton in the ϕ6 model. We link the dependence of this energy on the position of the soliton to the different masses.

  7. Dynamics of the quantum vacuum: Cosmology as relaxation to the equilibrium state

    Energy Technology Data Exchange (ETDEWEB)

    Klinkhamer, F R [Institute for Theoretical Physics, University of Karlsruhe, Karlsruhe Institute of Technology, 76128 Karlsruhe (Germany); Volovik, G E, E-mail:, E-mail: [Low Temperature Laboratory, Aalto University, PO Box 15100, FI-00076 AALTO (Finland)


    The behavior of the gravitating vacuum energy density in an expanding universe is discussed. A scenario is presented with a step-wise relaxation of the vacuum energy density. The vacuum energy density moves from plateau to plateau and follows, on average, the steadily decreasing matter energy density. The current plateau with a small positive value of the vacuum energy density (effective cosmological constant) may result from a still not equilibrated contribution of the light massive neutrinos to the quantum vacuum.

  8. Furnace brazing under partial vacuum (United States)

    Mckown, R. D.


    Brazing furnace utilizing partial-vacuum technique reduces tooling requirements and produces better bond. Benefit in that partial vacuum helps to dissociate metal oxides that inhibit metal flow and eliminates heavy tooling required to hold parts together during brazing.

  9. Tritium handling in vacuum systems

    Energy Technology Data Exchange (ETDEWEB)

    Gill, J.T. [Monsanto Research Corp., Miamisburg, OH (United States). Mound Facility; Coffin, D.O. [Los Alamos National Lab., NM (United States)


    This report provides a course in Tritium handling in vacuum systems. Topics presented are: Properties of Tritium; Tritium compatibility of materials; Tritium-compatible vacuum equipment; and Tritium waste treatment.

  10. Wave Beam Propagation Through Density Fluctuations

    NARCIS (Netherlands)

    Balakin, A. A.; Bertelli, N.; Westerhof, E.


    Perturbations induced by edge density fluctuations on electron cyclotron wave beams propagating in fusion plasmas are studied by means of a quasi-optical code. The effects of such fluctuations are illustrated here by showing the beam propagation in the case of single harmonic perturbations to the

  11. Exercise Effects on Night-to-Night Fluctuations in Self-rated Sleep among Older Adults with Sleep Complaints (United States)

    Buman, Matthew P.; Hekler, Eric B.; Bliwise, Donald L.; King, Abby C.


    Sleep interventions have rarely explored reductions in night-to-night fluctuations (i.e., intra-individual variability [IIV]) in sleep, despite the negative impacts of such fluctuations on affective states and cognitive and physical symptoms. In a community-based randomized controlled trial we evaluated whether physical exercise reduced IIV in self-rated sleep outcomes among middle-aged and older adults with sleep complaints. Under-active adults 55 years and older (N=66, 67% women) with mild to moderate sleep complaints were randomized to 12mos of a moderate-intensity endurance exercise (n=36) or a health education control group (n=30). Daily sleep logs, Pittsburgh Sleep Quality Index (PSQI), and in-home polysomnographic sleep recordings (PSG) were collected at baseline, 6mos, and 12mos. Sleep log-derived means and IIV were computed for sleep-onset latency (SOL), time in bed (TIB), feeling rested in the morning, number of nighttime awakenings, and wake after final awakening (WAFA). Using intent-to-treat methods, at 6mos no differences in IIV were observed by group. At 12mos, SOL-based IIV was reduced in the exercise group compared to the control (difference=23.11, 95% CI: 3.04–47.18, p=.025, Cohen’s d=0.57). This change occurred without mean-level or IIV changes in sleep-wake schedules. For all sleep variables except SOL and WAFA, IIV changes and mean-level changes in each variable were negatively correlated (r’s=−.312 to −.691, p’sSleep log-derived IIV changes were modestly correlated with mean-level PSQI and PSG-based changes at 12mos. Twelve months of moderate-intensity exercise reduced night-to-night fluctuations in self-rated time to fall asleep, and this relationship was independent of mean-level time to fall asleep. PMID:20629937

  12. Exercise effects on night-to-night fluctuations in self-rated sleep among older adults with sleep complaints. (United States)

    Buman, Matthew P; Hekler, Eric B; Bliwise, Donald L; King, Abby C


    Sleep interventions have rarely explored reductions in night-to-night fluctuations [i.e. intra-individual variability (IIV)] in sleep, despite the negative impacts of such fluctuations on affective states and cognitive and physical symptoms. In a community-based randomized controlled trial we evaluated whether physical exercise reduced IIV in self-rated sleep outcomes among middle-aged and older adults with sleep complaints. Under-active adults 55 years and older (n = 66, 67% women) with mild to moderate sleep complaints were randomized to 12 months of a moderate-intensity endurance exercise (n = 36) or a health education control group (n = 30). Daily sleep logs, Pittsburgh Sleep Quality Index (PSQI) and in-home polysomnographic sleep recordings (PSG) were collected at baseline, 6 months and 12 months. Sleep log-derived means and IIV were computed for sleep-onset latency (SOL), time in bed, feeling rested in the morning, number of nighttime awakenings, and wake after final awakening (WAFA). Using intent-to-treat methods, at 6 months no differences in IIV were observed by group. At 12 months, SOL-based IIV was reduced in the exercise group compared with the control (difference = 23.11, 95% CI: 3.04-47.18, P = 0.025, Cohen's d = 0.57). This change occurred without mean-level or IIV changes in sleep-wake schedules. For all sleep variables, except SOL and WAFA, IIV changes and mean-level changes in each variable were negatively correlated (r = -0.312 to -0.691, P Sleep log-derived IIV changes were modestly correlated with mean-level PSQI and PSG-based changes at 12 months. Twelve months of moderate-intensity exercise reduced night-to-night fluctuations in self-rated time to fall asleep, and this relationship was independent of mean-level time to fall asleep. © 2010 European Sleep Research Society.

  13. Superconducting fluctuation effect in CaFe0.88Co0.12AsF (United States)

    Xiao, H.; Gao, B.; Ma, Y. H.; Li, X. J.; Mu, G.; Hu, T.


    Out-of-plane angular dependent torque measurements were performed on CaFe0.88Co0.12AsF single crystals. Superconducting fluctuations, featured by magnetic field enhanced and exponential temperature dependent diamagnetism, are observed above the superconducting transition temperature T c, which is similar to that of cuprate superconductors, but less pronounced. In addition, the ratio of T c versus superfluid density follows well the Uemura line of high-T c cuprates, which suggests the exotic nature of the superconductivity in CaFe0.88Co0.12AsF.

  14. Effect of extreme data loss on long-range correlated and anticorrelated signals quantified by detrended fluctuation analysis. (United States)

    Ma, Qianli D Y; Bartsch, Ronny P; Bernaola-Galván, Pedro; Yoneyama, Mitsuru; Ivanov, Plamen Ch


    Detrended fluctuation analysis (DFA) is an improved method of classical fluctuation analysis for nonstationary signals where embedded polynomial trends mask the intrinsic correlation properties of the fluctuations. To better identify the intrinsic correlation properties of real-world signals where a large amount of data is missing or removed due to artifacts, we investigate how extreme data loss affects the scaling behavior of long-range power-law correlated and anticorrelated signals. We introduce a segmentation approach to generate surrogate signals by randomly removing data segments from stationary signals with different types of long-range correlations. The surrogate signals we generate are characterized by four parameters: (i) the DFA scaling exponent alpha of the original correlated signal u(i) , (ii) the percentage p of the data removed from u(i) , (iii) the average length mu of the removed (or remaining) data segments, and (iv) the functional form P(l) of the distribution of the length l of the removed (or remaining) data segments. We find that the global scaling exponent of positively correlated signals remains practically unchanged even for extreme data loss of up to 90%. In contrast, the global scaling of anticorrelated signals changes to uncorrelated behavior even when a very small fraction of the data is lost. These observations are confirmed on two examples of real-world signals: human gait and commodity price fluctuations. We further systematically study the local scaling behavior of surrogate signals with missing data to reveal subtle deviations across scales. We find that for anticorrelated signals even 10% of data loss leads to significant monotonic deviations in the local scaling at large scales from the original anticorrelated to uncorrelated behavior. In contrast, positively correlated signals show no observable changes in the local scaling for up to 65% of data loss, while for larger percentage of data loss, the local scaling shows

  15. Significant histamine formation in tuna ( Thunnus albacares ) at 2 degrees C - effect of vacuum- and modified atmosphere-packaging on psychrotolerant bacteria

    DEFF Research Database (Denmark)

    Emborg, Jette; Laursen, B. G.; Dalgaard, Paw


    Occurrence and importance of psychrotolerant histamine producing bacteria in chilled fresh tuna were demonstrated in the present study. The objective was to evaluate microbial formation of histamine and biogenic amines in chilled fresh tuna from the Indian Ocean and stored either vacuum-packed (VP......) or modified atmosphere-packed (MAP). Firstly, biogenic amines and the dominating microbiota were determined in VP tuna involved in an outbreak of histamine fish poisoning in Denmark. Secondly, the microbiota of fresh MAP tuna was evaluated at the time of processing in Sri Lanka and chemical, microbial...... and sensory changes were evaluated during storage at 1-3 degrees C. To explain the results obtained with naturally contaminated tuna the effect of VP and MAP on biogenic amine formation by psychrotolerant bacteria was evaluated in challenge tests at 2 degrees C and 10 degrees C. The VP tuna that caused...

  16. Gas molecule-molecule interaction and the gas-surface scattering effect on the rarefied gas flow through a slit into a vacuum (United States)

    Sazhin, O.


    The effect of the gas molecule-molecule interaction and the gas-surface scattering on the gas flow through a slit into a vacuum are investigated in a wide range of the gas rarefaction using the direct simulation Monte Carlo method. To study the gas molecule-molecule interaction influence, we used the variable hard sphere and variable soft sphere models defined for an inverse-power-law potential and the generalized hard sphere model defined for the 12-6 Lennard-Jones potential. The Maxwell, Cercignani-Lampis, and Epstein models were used to simulate the gas-surface scattering. This study demonstrates that the gas molecule-molecule interaction can have a significant influence on the rarefied gas flow through a slit, while the influence of the gas-surface scattering is negligibly small. The presented numerical results are in agreement with the corresponding experimental ones.

  17. Effect of cinnamon essential oil on bacterial diversity and shelf-life in vacuum-packaged common carp (Cyprinus carpio) during refrigerated storage. (United States)

    Zhang, Yuemei; Li, Dongping; Lv, Jian; Li, Qingzheng; Kong, Chunli; Luo, Yongkang


    The present study investigated the effect of cinnamon essential oil on the quality of vacuum-packaged common carp (Cyprinus carpio) fillets stored at 4±1°C in terms of sensory scores, physicochemical characteristics (total volatile basic nitrogen (TVB-N), biogenic amines, and color), and presence of spoilage microbiota. A total of 290,753 bacterial sequences and 162 different genera belonging to 14 phyla were observed by a high-throughput sequencing technique targeting the V3-V4 region of 16S rDNA, which showed a more comprehensive estimate of microbial diversity in carp samples compared with microbial enumeration. Before storage, Macrococcus and Aeromonas were the prevalent populations in the control samples, but cinnamon essential oil decreased the relative abundance of Macrococcus in the treated samples. Variability in the predominant microbiota in different samples during chilled storage was observed. Aeromonas followed by Lactococcus were the major contaminants in the spoiled control samples. Microbial enumeration also observed relatively higher counts of Aeromonas than other spoilage microorganisms. Compared with the control samples, cinnamon essential oil inhibited the growth of Aeromonas and Lactococcus were the predominant components in the treated samples on day 10; plate counts also revealed a relatively high level of lactic acid bacteria during refrigerated storage. However, there were no significant differences (P>0.05) in the composition of dominant microbiota between these two treatments at the end of the shelf-life. Furthermore, cinnamon essential oil treatment was more effective in inhibiting the increase of TVB-N and the accumulation of biogenic amines (especially for putrescine and cadaverine levels). Based primarily on sensory analysis, the use of cinnamon essential oil extended the shelf-life of vacuum-packaged common carp fillets by about 2days. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Effects of intermittent CO2convection under far-infrared radiation on vacuum drying of pre-osmodehydrated watermelon. (United States)

    Chakraborty, Rajat; Mondal, Pijus


    Watermelon, a tropical seasonal fruit with high nutrient content, requires preservation through drying due to its perishable nature. Nevertheless, drying of watermelon through conventional processes has a negative impact either on the drying time or on the final product quality. In this work, osmotic dehydration of watermelon followed by far-infrared radiation-assisted vacuum drying (FIRRAVD) was optimized to develop dehydrated watermelon with minimum moisture content. Significantly, during FIRRAVD, an attempt was made to further intensify the drying rate by forced convection through intermittent CO 2 injection. Drying kinetics of each operation and physicochemical qualities of dried products were evaluated. FIRRAVD was a viable method of watermelon drying with appreciably high moisture diffusivity (D eff,m ) of 4.97 × 10 -10 to 1.49 × 10 -9 m 2 s -1 compared to conventional tray drying. Moreover, intermittent CO 2 convection during FIRRAVD (ICFIRRAVD) resulted in appreciable intensification of drying rate, with enhanced D eff,m (9.93 × 10 -10 to 1.99 × 10 -9 m 2 s -1 ). Significantly, ICFIRRAVD required less energy and approximately 16% less time compared to FIRRAVD. The quality of the final dehydrated watermelon was superior compared to conventional drying protocols. The novel CO 2 convective drying of watermelon in the presence of far-infrared radiation demonstrated an energy-efficient and time-saving operation rendering a dehydrated watermelon with acceptable quality parameters. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  19. DIY Astrophysics: Examining diurnal and seasonal fluctuations in the effects of solar gravity using a three-axis accelerometer (United States)

    Romich, Kristine; Kruger, Andrew


    On the surface of the Earth, the acceleration due to the influence of the Sun's gravity is approximately 0.06% of that due to the Earth's own gravity (0.0006g). Nevertheless, it may be detected using a sensitive three-axis accelerometer such as the InvenSense MPU-6050, which is compatible with low-cost microcontrollers such as the Arduino and Raspberry Pi and hence provides an affordable means of investigation. Unlike the gravitational force between the Earth and an object on its surface, the x-, y-, and z-components of the gravitational force between the Sun and an earthbound observer are not constant: the vector direction of the gravitational acceleration caused by the Sun — denoted g⊙ — fluctuates as a function of the Earth's rotation (i.e., the time of day) and position in orbit (i.e., the time of year). The present investigation derives mathematical expressions for the instantaneous value of each component of g⊙ in terms of both quantities. It also outlines a method of using the InvenSense MPU-6050 to detect the corresponding fluctuations in total gravity (and, thus, the influence of the Sun's gravity) experimentally.

  20. Effect of ripples on the finite temperature elastic properties of hexagonal boron nitride using strain-fluctuation method (United States)

    Thomas, Siby; Ajith, K. M.; Valsakumar, M. C.


    This work intents to put forth the results of a classical molecular dynamics study to investigate the temperature dependent elastic constants of monolayer hexagonal boron nitride (h-BN) between 100 and 1000 K for the first time using strain fluctuation method. The temperature dependence of out-of-plane fluctuations (ripples) is quantified and is explained using continuum theory of membranes. At low temperatures, negative in-plane thermal expansion is observed and at high temperatures, a transition to positive thermal expansion has been observed due to the presence of thermally excited ripples. The decrease of Young's modulus, bulk modulus, shear modulus and Poisson's ratio with increase in temperature has been analyzed. The thermal rippling in h-BN leads to strong anharmonic behaviour that causes large deviation from the isotropic elasticity. A detailed study shows that the strong thermal rippling in large systems is also responsible for the softening of elastic constants in h-BN. From the determined values of elastic constants and elastic moduli, it has been elucidated that 2D h-BN sheets meet the Born's mechanical stability criterion in the investigated temperature range. The variation of longitudinal and shear velocities with temperature is also calculated from the computed values of elastic constants and elastic moduli.

  1. Effects of ICRF and/or LHCD on SOL density profiles and fluctuations in Alcator C-Mod (United States)

    Lau, Cornwall; Hanson, Greg; Lin, Yijun; Wukitch, Steve; Faust, Ian; Hughes, Jerry; Labombard, Brian; Ma, Yunxing; Meneghini, Orso; Parker, Ron; Shiraiwa, Syun'ichi; Terry, Jim; Wallace, Greg; Wilgen, John


    Antenna operation and antenna-plasma interactions during RF heating and current drive are greatly influenced by the scrape-off-layer (SOL) densities. A swept-frequency X-mode reflectometer installed on Alcator C-Mod measures the SOL density profiles and fluctuations at three poloidal locations adjacent to the Lower Hybrid (LH) launcher. The application of LH power consistently decreases the density in front of the LH launcher, consistent with a ponderomotive force; the application of ICRF power also decreases the density in front of the LH launcher, which may be consistent with ICRF sheath induced convective cells. LH power also seems to strongly modify the density profile shape in the near and far SOL, especially at high line averaged densities. The reflectometer measured density profiles and preliminary results on phase fluctuation behavior will be presented and compared with measurements from other diagnostics, such as Thomson scattering and gas puff imaging diagnostic. This work is supported by U.S. DoE under awards DE-AC05-00OR22725 and DE-FC02-99ER54512.

  2. Continuous information flow fluctuations (United States)

    Rosinberg, Martin Luc; Horowitz, Jordan M.


    Information plays a pivotal role in the thermodynamics of nonequilibrium processes with feedback. However, much remains to be learned about the nature of information fluctuations in small-scale devices and their relation with fluctuations in other thermodynamics quantities, like heat and work. Here we derive a series of fluctuation theorems for information flow and partial entropy production in a Brownian particle model of feedback cooling and extend them to arbitrary driven diffusion processes. We then analyze the long-time behavior of the feedback-cooling model in detail. Our results provide insights into the structure and origin of large deviations of information and thermodynamic quantities in autonomous Maxwell's demons.

  3. Band gaps induced by vacuum photons in closed semiconductor cavities


    Kibis, O. V.; Arnardottir, K. B.; Shelykh, I. A.


    We consider theoretically a closed (zero-dimensional) semiconductor microcavity where confined vacuum photonic mode is coupled to electrons in valence band of the semiconductor. It is shown that vacuum-induced virtual electron transitions between valence and conduction bands result in renormalization of electron energy spectrum. As a consequence, vacuum-induced band gaps appear within the valence band. Calculated values of the band gaps are of sub-meV scale, that makes this QED effect to be m...

  4. Vacuum distillation device

    Energy Technology Data Exchange (ETDEWEB)

    Hamer, J.A.; Burg, C.J. Van Der; Kanbier, D.; Heijden, P. Van Der.


    This invention relates to a vacuum distillation device comprising a vacuum distillation column, a furnace provided with a heat exchange tube, and a connecting conduit between the column and the heat exchange tube. Such a device is used to fractionate a hydrocarbon-containing feed sometimes referred to as long residue. An object of this invention is to provide a vacuum distillation device which allows vaporization of a major part of the feed upstream of the column inlet. To this end, the device according to the invention comprises a vacuum distillation device as described above, in which the inner diameter of the heat exchange tube increases along its length to between 2.4 and 3 times the inner diameter of the tube inlet, and in which the inner diameter of the connecting conduit gradually increases along its length to between 2.5 and 5.4 times the inner diameter of the tube outlet. During normal operation of the device of the invention, only less than 50 wt % of the feed is vaporized in the heat exchange tube in the furnace, and more feed is vaporized in the connecting conduit, so that at the outlet end of the conduit the feed comprises about 0.9 kg vapor per kg of feed. The invention provides improved heat transfer in the heat exchange tubes such that fouling is reduced, consequently more heat can be applied per unit of time in the heat exchange tube. This allows either heating of the feed to a higher temperature or increasing the throughput for the same temperature.

  5. Magnetic hysterysis evolution of Ni-Al alloy with Fe and Mn substitution by vacuum arc melting to produce the room temperature magnetocaloric effect material

    Energy Technology Data Exchange (ETDEWEB)

    Notonegoro, Hamdan Akbar [PPS Materials Science, FMIPA-Universitas Indonesia, Depok 16424 (Indonesia); Mechanical Engineering Dept., FT-Universitas Sultan Ageng Tirtayasa, Cilegon 42435 (Indonesia); Kurniawan, Budhy; Manaf, Azwar, E-mail: [PPS Materials Science, FMIPA-Universitas Indonesia, Depok 16424 (Indonesia); Setiawan, Jan [Center for Nuclear Fuel Tecnology-Badan Tenaga Atom Nasional, Tangerang Selatan 15310 (Indonesia)


    The development of magnetocaloric effect (MCE) material is done in order to reduce the damage of the ozone layer caused by the chlorofluorocarbons (CFCs) emitted into the air. The research dealing with synthesis of magnetocaloric materials based of Ni-Al Heusler Alloy structure and by varying substitution some atoms of Ni with Fe and Al with Mn on Ni-Al Heusler Alloy structure to become Ni{sub 44}Fe{sub 6}Mn{sub 32}Al{sub 18}. Vacuum Arc Melting (VAM) equipment is used to form the alloys on vacuum condition and by flowing argon gas atmosphere and then followed by annealing process for 72 hours. X-Ray Diffraction (XRD) reveals that crystallite structure of material is observed. We define that Ni{sub 44}Fe{sub 6} as X{sub 2}, Mn{sub 25} as Y, and Al{sub 18}Mn{sub 7} as Z. Based on the XRD result, we observed that the general formula X{sub 2}YZ is not changed. The PERMAGRAF measurement revealed that there exists of magnetic hysterysis. The hysterysis show that the magnetic structures of the system undego evolution from diamagnetic to soft ferromagnetic material which all of the compound have the same crystallite structure. This evolution indicated that the change in the composition has led to changes the magnetic composition. Mn is the major element that gives strong magnetic properties to the sample. When Mn partially replaced position of Al, the sample became dominant to be influenced to improve their magnetic properties. In addition, substitution a part of Ni by Fe in the composition reveals a pinning of the domain walls in the sample.


    Directory of Open Access Journals (Sweden)

    Zaid A. Abdulrahman


    Full Text Available Simulated column performance curves were constructed for existing paraffin separation vacuum distillation column in LAB plant (Arab Detergent Company/Baiji-Iraq. The variables considered in this study are the thermodynamic model option, top vacuum pressure, top and bottom temperatures, feed temperature, feed composition & reflux ratio. Also simulated columns profiles for the temperature, vapor & liquid flow rates composition were constructed. Four different thermodynamic model options (SRK, TSRK, PR, and ESSO were used, affecting the results within 1-25% variation for the most cases.The simulated results show that about 2% to 8 % of paraffin (C10, C11, C12, & C13 present at the bottom stream which may cause a problem in the LAB plant. The major variations were noticed for the top temperature & the  paraffin weight fractions at bottom section with top vacuum pressure. The bottom temperature above 240 oC is not recommended because the total bottom flow rate decreases sharply, where as  the weight fraction of paraffins decrease slightly. The study gives evidence about a successful simulation with CHEMCAD

  7. Effect of vacuum spine board immobilization on incidence of pressure ulcers during evacuation of military casualties from theater. (United States)

    Mok, James M; Jackson, Keith L; Fang, Raymond; Freedman, Brett A


    In the summer of 2009, the vacuum spine board (VSB) was designated by the US Air Force as the preferred method of external spinal immobilization during aeromedical transport of patients with suspected unstable thoracolumbar spine fractures. One purported advantage of the VSB is that, by distributing weight over a larger surface area, it decreases the risk of skin pressure ulceration. To examine whether the rate of pressure ulcers has changed since the introduction of the VSB. Retrospective cohorts. Injured US service members undergoing spinal immobilization during evacuation from the Iraq and Afghanistan theaters to Landstuhl, Germany. Presence and stage of pressure ulceration, and deterioration in neurologic status. Records of the initial 60 patients medically evacuated on the VSB to Landstuhl Regional Medical Center were retrospectively analyzed for patient demographics, injury characteristics, and incidence of pressure injury. The incidence of pressure ulcers after the use of VSB was compared with that in a historical control consisting of 30 patients with unstable spinal injuries evacuated before the introduction of the VSB. No sources of external funding were used for this investigation. The combined cohort had a mean age of 28.8 years and mean Injury Severity Score (ISS) of 20.63 and comprised 96% men. Most injury mechanisms were blunt (58%). The rate of neurological injury was 19%. There were no cases of progressive neurological deficit or deformity in either cohort. In the VSB group, using a broad definition of pressure ulcer, incidence was 13 of 60 patients (22%). Using a strict definition, incidence was eight of 60 (13%): five Stage I and three Stage II. In the non-VSB group, incidence of pressure ulcers was three of 30 (10%), using either definition, all Stage II. Difference in incidence between the groups was not statistically significant. Intubated patients had a significantly higher incidence of pressure ulcers. Both the VSB and historic means (non

  8. Scaling metabolic rate fluctuations


    Labra, Fabio A.; Marquet, Pablo A.; Bozinovic, Francisco


    Complex ecological and economic systems show fluctuations in macroscopic quantities such as exchange rates, size of companies or populations that follow non-Gaussian tent-shaped probability distributions of growth rates with power-law decay, which suggests that fluctuations in complex systems may be governed by universal mechanisms, independent of particular details and idiosyncrasies. We propose here that metabolic rate within individual organisms may be considered as an example of an emerge...

  9. Superconducting fluctuation effect in CaFe0.88Co0.12AsF (United States)

    Xiao, H.; Gao, B.; Ma, Y. H.; Li, X. J.; Mu, G.; Hu, T.

    Out-of-plane angular dependent torque measurements were performed on CaFe0.88Co0.12AsF single crystals. Superconducting fluctuations, featured by magnetic field enhanced and exponential temperature dependent diamagnetism, are observed above the superconducting transition temperature Tc, which is similar to that of cuprate superconductors, but less pronounced. In addition, the ratio of Tc versus superfluid density follows well the Uemura line of high-Tc cuprates, which suggests the exotic nature of the superconductivity in CaFe0.88Co0.12AsF The authors acknowledge the support of NSFC, Grant No. U1530402, 11574338 and 11204338, MOST of China, Grant No. 2015CB921303, the 'Strategic Priority Research Program (B)' of the Chinese Academy of Sciences (no. XDB04040300, XDB 04040200 and XDB 04030000.

  10. Effect of proton irradiation on the fluctuation-induced magnetoconductivity of FeSe1-x Te x thin films (United States)

    Ahmad, D.; Choi, W. J.; Seo, Y. I.; Seo, Sehun; Lee, Sanghan; Park, Tuson; Mosqueira, J.; Gu, Genda; Kwon, Yong Seung


    The influence of proton irradiation on the fluctuation-induced magnetoconductivity of high quality FeSe1-x Te x (x = 0.4, 0.55) (FST) thin films has been investigated. The measurements were performed with magnetic fields up to 13 T applied in the two main crystal directions. The results were interpreted in terms of the Ginzburg-Landau approach for three-dimensional materials under a total-energy cutoff. The analysis shows that properly-tuned proton irradiation does not appreciably affect fundamental superconducting parameters like the T c value, the upper critical fields or the anisotropy. This has important consequences from the point of view of possible applications due to the enhancement of vortex pinning induced by irradiation.

  11. Effect of significant data loss on identifying electric signals that precede rupture estimated by detrended fluctuation analysis in natural time. (United States)

    Skordas, E S; Sarlis, N V; Varotsos, P A


    Electric field variations that appear before rupture have been recently studied by employing the detrended fluctuation analysis (DFA) to quantify their long-range temporal correlations. These studies revealed that seismic electric signal (SES) activities exhibit a scale invariant feature with an exponent αDFA≈1 over all scales investigated (around five orders of magnitude). Here, we study what happens upon significant data loss, which is a question of primary practical importance, and show that the DFA applied to the natural time representation of the remaining data still reveals for SES activities an exponent close to 1.0, which markedly exceeds the exponent found in artificial (man-made) noises. This enables the identification of a SES activity with probability of 75% even after a significant (70%) data loss. The probability increases to 90% or larger for 50% data loss.

  12. Thermodynamic properties of paramagnetic α - and β -Mn from first principles: The effect of transverse spin fluctuations (United States)

    Ehteshami, Hossein; Korzhavyi, Pavel A.


    First-principles-based thermodynamic modeling of cubic α and β phases of Mn represent a challenge due to their structural complexity and the necessity of simultaneous treatment of several types of disorder (electronic, magnetic, and vibrational) that have very different characteristic time scales. Here we employ mean-field theoretical models to describe the different types of disorder and then we connect each layer of theory to the others using the adiabatic principle of separating faster and slower degrees of freedom. The slowest (vibrational) degrees of freedom are treated using the Moruzzi, Janak, and Schwarz formalism [Phys. Rev. B 37, 790 (1988), 10.1103/PhysRevB.37.790] of the Debye-Grüneisen model parametrized based on the first-principles calculated equation of state which includes the free-energy contributions due to the fast (electronic and magnetic) degrees of freedom via the Fermi-Dirac distribution function and a mean-field theory of transverse spin fluctuations. The magnetic contribution due to transverse spin fluctuations has been computed self-consistently within the disordered local moment picture of the paramagnetic state. The obtained results for thermodynamic properties such as lattice parameter, linear thermal expansion coefficient, and heat capacity of both phases show a good agreement with available experimental data. We also tested the assumption about the nature (localized versus delocalized) of magnetic moment on site IV in α -Mn and site I in β -Mn on the thermodynamic properties of these two phases. Similar to the findings of experimental studies, we conclude that magnetic moment on site IV in α -Mn is not of a localized character. However, a similar analysis suggests that the magnetic moment of site I in β -Mn should be treated as localized.

  13. Renewable energy powered membrane technology. 2. The effect of energy fluctuations on performance of a photovoltaic hybrid membrane system. (United States)

    Richards, B S; Capão, D P S; Schäfer, A I


    This paper reports on the performance fluctuations during the operation of a batteryless hybrid ultrafiltration--nanofiltration/reverse osmosis (UF-NF/RO) membrane desalination system powered by photovoltaics treating brackish groundwater in outback Australia. The renewable energy powered membrane (RE-membrane) system is designed to supply clean drinking water to a remote community of about 50 inhabitants. The performance of the RE-membrane system over four different solar days is summarized using four different NF membranes (BW30, NF90, ESPA4, TFC-S), and examined in more detail for the BW30 membrane. On an Australian spring day, the system produced 1.1 m3 of permeate with an average conductivity of 0.28 mS x cm(-1), recovering 28% of the brackish (8.29 mS x cm(-1) conductivity) feedwater with an average specific energy consumption of 2.3 kWh x m(-3). The RE-membrane system tolerated large fluctuations in solar irradiance (500--1200 W x m(-2)), resulting in only small increases in the permeate conductivity. When equipped with the NF90 (cloudy day) and ESPA4 (rainy day) membranes, the system was still able to produce 1.36 m(-3) and 0.85 m(-3) of good quality permeate, respectively. The TFC-S membrane was not able to produce adequate water quality from the bore water tested. It is concluded that batteryless operation is a simple and robust way to operate such systems under conditions ranging from clear skies to medium cloud cover.

  14. Scalar fluctuations of the scalar metric during inflation from a non-perturbative 5D large-scale repulsive gravity model

    Energy Technology Data Exchange (ETDEWEB)

    Madriz Aguilar, Jose Edgar; Reyes, Luz M.; Moreno, Claudia [Universidad de Guadalajara (UdG), Departamento de Matematicas, Centro Universitario de Ciencias Exactas e ingenierias (CUCEI), Guadalajara, Jalisco (Mexico); Bellini, Mauricio [Universidad Nacional de Mar del Plata (UNMdP), Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Funes 3350, C.P. 7600, Mar del Plata (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Instituto de Investigaciones Fisicas de Mar del Plata (IFIMAR), Mar del Plata (Argentina)


    We develop a non-perturbative formalism for scalar metric fluctuations from a 5D extended version of general relativity in vacuum. In this work we concentrate our efforts on calculations valid on large cosmological scales, which are dominant during the inflationary phase of the universe. The resulting metric in this limit is obtained after implementing a planar coordinate transformation on a 5D Ricci-flat metric solution. We calculate the spectrum of these fluctuations with an effective 4D Schwarzschild-de Sitter spacetime on cosmological scales, which is obtained after we make a static foliation on the non-compact extra coordinate. Our results show how the squared metric fluctuations of the primordial universe become scale invariant with the inflationary expansion. (orig.)

  15. Ultrahigh-vacuum field emitter array wafer tester

    Energy Technology Data Exchange (ETDEWEB)

    Gray, H.F.; Ardis, L.; Campisi, G.J.


    The device reported here allows the researcher the opportunity of gaining primitive yield information, threshold voltages, emission stability, and other information, e.g., gas effects, on field emitter arrays (FEA) which are microminiature ''vacuum tubes'' fabricated by microelectronic processing methods on silicon wafers, without scribing, dicing, and mounting each device on individual vacuum-compatible headers. This device also speeds up the entire data-acquisition process by requiring only one ultrahigh-vacuum pumpdown and one set of vacuum feedthroughs.

  16. Influence of high blood glucose fluctuation on endothelial function of type 2 diabetes mellitus rats and effects of Panax Quinquefolius Saponin of stem and leaf. (United States)

    Wang, Jing-Shang; Yin, Hui-Jun; Guo, Chun-Yu; Huang, Ye; Xia, Cheng-Dong; Liu, Qian


    To observe the influence of high blood glucose fluctuation on the endothelial function of type 2 diabetes mellitus (T2DM) rats and the effects of Panax Quinquefolius Saponin (PQS) of stem and leaf. The T2DM model was induced by intraperitoneal injection of a small dose of streptozotocin (STZ, 35 mg/kg) plus high fat and high caloric laboratory chow. Then, diabetic rats were divided into steady high blood glucose (SHG) group and fluctuant high blood glucose (FHG) group according to fasting blood glucose coefficient of variation (FBG-CV), and then, the FHG group rats were divided into 4 groups according to the level of FBG-CV and fasting blood glucose: PQS 30 mg/(kg·d) group, PQS 60 mg/(kg·d) group, metformin hydrochloride control (MHC) group, and FHG control group, 10 in each group. Meanwhile, 10 rats without any treatment were used as normal control (NOR) group. Eight weeks later, the aortic arteries histology, plasma hepatocyte growth factor (HGF), and serum nitric oxide (NO), endothelin-1 (ET-1), tumor necrosis factor α (TNF-α), and soluble intercellular adhesion molecule 1 (sICAM-1) were measured. In comparison with the NOR group, the level of plasma HGF and serum NO, ET-1 and TNF-α, and sICAM-1 in SHG and FHG control groups were all significantly increased (Ptreatment. Blood glucose fluctuation could facilitate the development of vascular endothelial dysfunction in T2DM rats, while PQS could improve the endothelial function of T2DM rats with high blood glucose fluctuation, which may be related to its effects of relieving vessel stress, decreasing vasoconstrictor ET-1 production, preventing compensated increase of NO, and reducing inflammatory reaction.

  17. Milking performance evaluation and factors affecting milking claw vacuum levels with flow simulator. (United States)

    Enokidani, Masafumi; Kawai, Kazuhiro; Shinozuka, Yasunori; Watanabe, Aiko


    Milking performance of milking machines that matches the production capability of dairy cows is important in reducing the risk of mastitis, particularly in high-producing cows. This study used a simulated milking device to examine the milking performance of the milking system of 73 dairy farms and to analyze the factors affecting claw vacuum. Mean claw vacuum and range of fluctuation of claw vacuum (claw vacuum range) were measured at three different flow rates: 5.7, 7.6 and 8.7 kg/min. At the highest flow rate, only 16 farms (21.9%) met both standards of mean claw vacuum ≥35 kPa and claw vacuum range ≤ 7 kPa, showing that milking systems currently have poor milking performance. The factors affecting mean claw vacuum were claw type, milk-meter and vacuum shut-off device; the factor affecting claw vacuum range was claw type. Examination of the milking performance of the milking system using a simulated milking device allows an examination of the performance that can cope with high producing cows, indicating the possibility of reducing the risk of mastitis caused by inappropriate claw vacuum. © 2016 Japanese Society of Animal Science.

  18. Biomolecules: Fluctuations and relaxations (United States)

    Parak, F.; Ostermann, A.; Gassmann, A.; Scherk, C.; Chong, S.-H.; Kidera, A.; Go, N.


    The normal-mode refinement of X-ray crystallographic data opened a new possibility to analyze the mean-square displacements in a protein molecule. A comparison of the X-ray structure of myoglobin at several temperatures with Mössbauer data is performed. In the low-temperature regime below 180 K the iron mean-square displacements obtained by Mössbauer spectroscopy are in good agreement with a normal-mode analysis. The X-ray mean-square displacements at the position of the iron, after the motion originated from the external degrees of freedom are subtracted, have practically the same temperature dependence as those from Mössbauer spectroscopy. The difference between the X-ray mean-square displacements and those predicted by normal-mode analysis measures the distribution of molecules into conformational substates. Above 180 K the Mössbauer effect indicates fluctuations between conformational substates. The relaxation from a Fe(III) conformation to a Fe(II) conformation is shown for superoxide dismutase of Propionibacterium shermanii.

  19. Parity fluctuations in stellar dynamos (United States)

    Moss, D. L.; Sokoloff, D. D.


    Observations of the solar butterfly diagram from sunspot records suggest persistent fluctuations in parity, away from the overall, approximately dipolar pattern. A simple mean-field dynamo model is used with a solar-like rotation law and perturbed α effect. The parity of the magnetic field relative to the rotational equator can demonstrate can be described as resonance behavior, while the magnetic energy behaves in a more or less expected way. Possible applications of this effect are discussed in the context of various deviations of the solar magnetic field from dipolar symmetry, as reported from analyses of archival sunspot data. The model produces fluctuations in field parity, and hence in the butterfly diagram, that are consistent with observed fluctuaions in solar behavior.

  20. Determination of Kicker Vacuum Requirements

    Energy Technology Data Exchange (ETDEWEB)

    Schulze, Martin E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)


    This note examines the effect of elevated vacuum pressures in the kicker region of the DARHT 2nd Axis which can lead to changes in the beam tune due to the long pulse length. The kicker uses Rexolite as an insulator supporting the electrodes. Rexolite is hygroscopic resulting is a large outgassing rate and prolonged pump down times after exposure to atmospheric conditions. LAMDA [1] is used to simulate the effect of ionization of the residual gas resulting in partial space charge neutralization and changes to the tune between the beginning and end of the pulse. The effect of the ion-hose instability is also examined. The purpose of this note is to establish/validate the required pressure in the downstream transport.