WorldWideScience

Sample records for hydrodynamically balanced system

  1. HYDRODYNAMICALLY BALANCED SYSTEMS (HBS: INNOVATIVE APPROACH OF GASTRO RETENTION: A REVIEW

    Directory of Open Access Journals (Sweden)

    Dubey Vivek

    2012-06-01

    Full Text Available The objective of writing this review on hydrodynamically balanced systems (HBS was collection of the recent literature. The design of hydrodynamically balanced drug delivery system is base on prolong GI residence time of drug in an area of the GI tract to maximize drug reaching its absorption. Gastrointestinal transit time of orally administered dosage forms are controlled by using gastro retentive drug delivery systems (GRDDS. Need for GRDDS a controlled drug delivery system with prolonged residence time in the stomach. Floating drug delivery systems is one of the important approaches to achieve gastric retention to obtain sufficient drug bioavailability. This delivery system is desirable for drugs with an absorption window in the stomach or in the upper small intestine.

  2. Hydrodynamics of charge fluctuations and balance functions

    CERN Document Server

    Ling, B; Stephanov, M

    2013-01-01

    We apply stochastic hydrodynamics to the study of charge density fluctuations in QCD matter undergoing Bjorken expansion. We find that the charge density correlations are given by a time integral over the history of the system, with the dominant contribution coming from the QCD crossover region where the change of susceptibility per entropy, chi T/s, is most significant. We study the rapidity and azimuthal angle dependence of the resulting charge balance function using a simple analytic model of heavy-ion collision evolution. Our results are in agreement with experimental measurements, indicating that hydrodynamic fluctuations contribute significantly to the measured charge correlations in high energy heavy-ion collisions. The sensitivity of the balance function to the value of the charge diffusion coefficient D allows us to estimate the typical value of this coefficient in the crossover region to be rather small, of the order of 1/(2pi T), characteristic of a strongly coupled plasma.

  3. Balance equations in semi-relativistic quantum hydrodynamics

    CERN Document Server

    Ivanov, A Yu; Kuz'menkov, L S

    2014-01-01

    Method of the quantum hydrodynamics has been applied in quantum plasmas studies. As the first step in our consideration, derivation of classical semi-relativistic (i. e. described by the Darwin Lagrangian on microscopic level) hydrodynamical equations is given after a brief review of method development. It provides better distinguishing between classic and quantum semi-relativistic effects. Derivation of the classical equations is interesting since it is made by a natural, but not very widespread method. This derivation contains explicit averaging of the microscopic dynamics. Derivation of corresponding quantum hydrodynamic equations is presented further. Equations are obtained in the five-momentum approximation including the continuity equation, Euler and energy balance equations. It is shown that relativistic corrections lead to presence of new quantum terms in expressions for a force field, a work field etc. The semi-relativistic generalization of the quantum Bohm potential is obtained. Quantum part of the...

  4. Holography and hydrodynamics in small systems

    Science.gov (United States)

    Chesler, Paul M.

    2016-12-01

    Using holographic duality, we present results for the off-center collision of Gaussian wave packets in strongly coupled N = 4 supersymmetric Yang-Mills theory. The wave packets are thin along the collision axis and superficially at least resemble Lorentz contracted colliding protons. The collision results in the formation of a droplet of liquid of size R ∼ 1 /Teff where Teff is the effective temperature, which is the characteristic microscopic scale in strongly coupled plasma. These results demonstrate the applicability of hydrodynamics to microscopically small systems and bolster the notion that hydrodynamics can be applied to heavy-light ion collisions as well as proton-proton collisions.

  5. Physics-based analysis of the hydrodynamic stress in a fluid-particle system

    NARCIS (Netherlands)

    Zhang, Quan; Prosperetti, Andrea

    2010-01-01

    The paper begins by showing how standard results on the average hydrodynamic stress in a uniform fluid-particle system follow from a direct, elementary application of Cauchy’s stress principle. The same principle applied to the angular momentum balance proves the emergence, at the mesoscale, of an a

  6. Balancing for unstable nonlinear systems

    NARCIS (Netherlands)

    Scherpen, J.M.A.

    1993-01-01

    A previously obtained method of balancing for stable nonlinear systems is extended to unstable nonlinear systems. The similarity invariants obtained by the concept of LQG balancing for an unstable linear system can also be obtained by considering a past and future energy function of the system. By c

  7. Chitosan-Hydroxypropyl Methylcellulose Matrices as Carriers for Hydrodynamically Balanced Capsules of Moxifloxacin HCl.

    Science.gov (United States)

    Verma, Anurag; Dubey, Juhi; Verma, Navneet; Nayak, Amit Kumar

    2017-01-01

    In recent years, gastroretentive, hydrodynamically balanced system (HBS) for stomach-specific floating sustained drug release has gained a lot of importance in improving absorption of drugs especially those absorbed from stomach and small intestine. The objective of the current investigation is to evaluate chitosan-hydroxypropyl methylcellulose (HPMC) based on polymeric matrices as a carrier for single-unit capsules based on HBS for stomach- specific floating sustained drug release using moxifloxacin HCl (MX) as a model drug. Various HBS capsules of MX were prepared by physical blending of MX with chitosan (low or medium molecular mass) or HPMC (K4M or K15M) or chitosan-HPMC combinations in varying proportions followed by encapsulation into size 0 capsules made of hard gelatin. The in vitro buoyancy and drug release in 0.1 N HCl (pH 1.2) were evaluated. HBS capsules based on chitosan (low and medium molecular weight and their combination) as polymer matrix failed to float on 0.1 N HCl (pH 1.2). Whereas, formulations containing HPMC (K4M or K15M) or their mixture with chitosan, remained buoyant and released MX over 9 h in the acidic dissolution medium following zero-order kinetics. HPMC (K4M, K15M, blend of K4M and K15M) or their mixture with low/medium molecular mass chitosan may constitute excellent carrier systems for the stomach-specific sustained delivery of MX over a longer period. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  8. Hydrodynamics of the Veracruz Reef System

    Science.gov (United States)

    Marin Hernandez, M.

    2013-05-01

    One year of hydrographic and current measurements in the Veracruz Reef System National Park (VRSNP) at the southwestern Gulf of Mexico are analyzed. To our knowledge, this is the first study of seasonal variations from observations in the region. The area has a particular dynamics because this reef system receives discharges of three rivers, in the northern (Antigua river), in the center (Jamapa river) and in the southern (Papaloapan river), dividing the VRSNP in two reef groups. In order to know the hydrodynamics, four transects perpendicular to the coast were accomplished, two on every side of the reef groups. Up to the date, there have been completed 6 oceanographic campaigns every 2 months, where ADCP currents data were collected continuously on all transects and thermohaline fields were obtained from 24 survey stations along transects using CTD. The area has three well-marked seasons: dry, rain and Nortes (strong winds resulting from the passage of cold fronts). During the rain season the river discharges have a significant impact in the thermohaline profiles. Temporary changes in stratification of the water column, spatial distribution of temperature and salinity, as well as temporary changes in currents direction were established for the three seasons.

  9. Rotor balancing apparatus and system

    Science.gov (United States)

    Lyman, Frank (Inventor); Lyman, Joseph (Inventor)

    1976-01-01

    Rotor balancing apparatus and a system comprising balance probes for measuring unbalance at the ends of a magnetically suspended rotor are disclosed. Each balance probe comprises a photocell which is located in relationship to the magnetically suspended rotor such that unbalance of the rotor changes the amount of light recorded by each photocell. The signal from each photocell is electrically amplified and displayed by a suitable device, such as an oscilloscope.

  10. Hydrodynamics Research on Amphibious Vehicle Systems: Engineering Application

    Institute of Scientific and Technical Information of China (English)

    JU Nai-jun

    2006-01-01

    Based on the modeling theoretical research of the amphibious vehicle systems, a simulation computed architecture on the state space expressions of hydrodynamics for amphibious vehicle systems are educed, and simulation computed results of navigation characteristics, vibration-impact characteristics, firing-hitting characteristics for amphibious vehicle on water are given. It is shown that the hydrodynamic research on amphibious vehicle systems is necessary and feasible.

  11. Hydrodynamics Research on Amphibious Vehicle Systems:Modeling Theory

    Institute of Scientific and Technical Information of China (English)

    JU Nai-jun

    2006-01-01

    For completing the hydrodynamics software development and the engineering application research on the amphibious vehicle systems, hydrodynamic modeling theory of the amphibious vehicle systems is elaborated, which includes to build up the dynamic system model of amphibious vehicle motion on water, gun tracking-aiming-firing, bullet hit and armored check-target, gunner operating control, and the simulation computed model of time domain for random sea wave.

  12. Formulation optimization of hydrodynamically balanced oral controlled release bioadhesive tablets of tramadol hydrochloride.

    Science.gov (United States)

    Singh, Bhupinder; Rani, Ashu; Babita; Ahuja, Naveen; Kapil, Rishi

    2010-01-01

    The directly compressible floating-bioadhesive tablets of tramadol were formulated using varying amounts Carbopol 971P (CP) and hydroxy-propylmethyl cellulose (HPMC), along with other requisite excipients. In vitro drug release profile, floatational characteristics and ex vivo bioadhesive strength using texture analyzer were determined, and systematically optimized using a 3(2) central composite design (CCD). The studies indicated successful formulation of gastroretentive compressed matrices with excellent controlled release, mucoadhesion and hydrodynamic balance. Comparison of the dissolution profiles of the optimized formulation, with optimal composition of CP:HPMC :: 80.0:125.0, with that of the marketed controlled release formulation other indicated analogy of drug release performance with each other. Validation of optimization study using eight confirmatory experimental runs indicated very high degree of prognostic ability of CCD with mean  SEM of â0.06%  0.37. Further, the study successfully unravels the effect of the polymers on the selected response variables.

  13. Identifying Balance in a Balanced Scorecard System

    Science.gov (United States)

    Aravamudhan, Suhanya; Kamalanabhan, T. J.

    2007-01-01

    In recent years, strategic management concepts seem to be gaining greater attention from the academicians and the practitioner's alike. Balanced Scorecard (BSC) concept is one such management concepts that has spread in worldwide business and consulting communities. The BSC translates mission and vision statements into a comprehensive set of…

  14. Small systems and regulator dependence in relativistic hydrodynamics

    CERN Document Server

    Spalinski, Michal

    2016-01-01

    Consistent theories of hydrodynamics necessarily include nonhydrodynamic modes, which can be viewed as a regulator necessary to ensure causality. Under many circumstances the choice of regulator is not relevant, but this is not always the case. In particular, for sufficiently small systems (such as those arising in pA or pp collisions) such dependence may be inevitable. We address this issue in the context of M\\"uller-Israel-Stewart theory of relativistic hydrodynamics. In this case, by demanding that the nonhydrodynamic modes do not dominate, we find that regulator dependence becomes inevitable only for multiplicities $dN/dY$ of the order of a few. This conclusion supports earlier studies based on hydrodynamic simulations of small systems, at the same time providing a simple physical picture of how hydrodynamics can be reliable even in such seemingly extreme conditions.

  15. Automatization of hydrodynamic modelling in a Floreon+ system

    Science.gov (United States)

    Ronovsky, Ales; Kuchar, Stepan; Podhoranyi, Michal; Vojtek, David

    2017-07-01

    The paper describes fully automatized hydrodynamic modelling as a part of the Floreon+ system. The main purpose of hydrodynamic modelling in the disaster management is to provide an accurate overview of the hydrological situation in a given river catchment. Automatization of the process as a web service could provide us with immediate data based on extreme weather conditions, such as heavy rainfall, without the intervention of an expert. Such a service can be used by non scientific users such as fire-fighter operators or representatives of a military service organizing evacuation during floods or river dam breaks. The paper describes the whole process beginning with a definition of a schematization necessary for hydrodynamic model, gathering of necessary data and its processing for a simulation, the model itself and post processing of a result and visualization on a web service. The process is demonstrated on a real data collected during floods in our Moravian-Silesian region in 2010.

  16. Hydrodynamics and morphodynamics of a seasonally forced tidal inlet system

    NARCIS (Netherlands)

    Lam, N.T.; Stive, M.J.F.; Wang, Z.B.; Verhagen, H.J.; Thuy, V.T.T.

    2008-01-01

    Hydrodynamics and morphodynamics of a seasonally forced tidal inlet system are investigated using numerical models. The ocean forcing including tidal and wave actions and sediment transport is simulated using Delft3D model. Fluvial processes in Delft3D are taken into account as results from SOBEK RU

  17. Hydrodynamics and morphodynamics of a seasonally forced tidal inlet system

    NARCIS (Netherlands)

    Lam, N.T.; Stive, M.J.F.; Wang, Z.B.; Verhagen, H.J.; Thuy, V.T.T.

    2008-01-01

    Hydrodynamics and morphodynamics of a seasonally forced tidal inlet system are investigated using numerical models. The ocean forcing including tidal and wave actions and sediment transport is simulated using Delft3D model. Fluvial processes in Delft3D are taken into account as results from SOBEK

  18. High Efficiency Hydrodynamic DNA Fragmentation in a Bubbling System

    Science.gov (United States)

    Li, Lanhui; Jin, Mingliang; Sun, Chenglong; Wang, Xiaoxue; Xie, Shuting; Zhou, Guofu; van den Berg, Albert; Eijkel, Jan C. T.; Shui, Lingling

    2017-01-01

    DNA fragmentation down to a precise fragment size is important for biomedical applications, disease determination, gene therapy and shotgun sequencing. In this work, a cheap, easy to operate and high efficiency DNA fragmentation method is demonstrated based on hydrodynamic shearing in a bubbling system. We expect that hydrodynamic forces generated during the bubbling process shear the DNA molecules, extending and breaking them at the points where shearing forces are larger than the strength of the phosphate backbone. Factors of applied pressure, bubbling time and temperature have been investigated. Genomic DNA could be fragmented down to controllable 1-10 Kbp fragment lengths with a yield of 75.30-91.60%. We demonstrate that the ends of the genomic DNAs generated from hydrodynamic shearing can be ligated by T4 ligase and the fragmented DNAs can be used as templates for polymerase chain reaction. Therefore, in the bubbling system, DNAs could be hydrodynamically sheared to achieve smaller pieces in dsDNAs available for further processes. It could potentially serve as a DNA sample pretreatment technique in the future.

  19. Algebro-geometric approach in the theory of integrable hydrodynamic type systems

    OpenAIRE

    Pavlov, Maxim V.

    2006-01-01

    The algebro-geometric approach for integrability of semi-Hamiltonian hydrodynamic type systems is presented. This method is significantly simplified for so-called symmetric hydrodynamic type systems. Plenty interesting and physically motivated examples are investigated.

  20. GenASiS: General Astrophysical Simulation System. II. Nonrelativistic Hydrodynamics

    CERN Document Server

    Cardall, Christian Y; Endeve, Eirik; Mezzacappa, Anthony

    2012-01-01

    In this paper, the second in a series, we document the algorithms and solvers for compressible nonrelativistic hydrodynamics implemented in GenASiS (General Astrophysical Simulation System)---a new code being developed initially and primarily, though by no means exclusively, for the simulation of core-collapse supernovae. In the Mathematics division of GenASiS we introduce Solvers, which includes finite-volume updates for generic hyperbolic BalanceEquations and ordinary differential equation integration Steps. We also introduce the Physics division of GenASiS; this extends the Manifolds division of Mathematics into physical Spaces, defines StressEnergies, and combines these into Universes. We benchmark the hydrodynamics capabilities of GenASiS against many standard test problems; the results illustrate the basic competence of our implementation, demonstrate the manifest superiority of the HLLC over the HLL Riemann solver in a number of interesting cases, and provide preliminary indications of the code's abili...

  1. Effect of short range hydrodynamic on bimodal colloidal gel systems

    Science.gov (United States)

    Boromand, Arman; Jamali, Safa; Maia, Joao

    2015-03-01

    Colloidal Gels and disordered arrested systems has been studied extensively during the past decades. Although, they have found their place in multiple industries such as cosmetic, food and so on, their physical principals are still far beyond being understood. The interplay between different types of interactions from quantum scale, Van der Waals interaction, to short range interactions, depletion interaction, and long range interactions such as electrostatic double layer makes this systems challenging from simulation point of view. Many authors have implemented different simulation techniques such as molecular dynamics (MD) and Brownian dynamics (BD) to capture better picture during phase separation of colloidal system with short range attractive force. However, BD is not capable to include multi-body hydrodynamic interaction and MD is limited by the computational resources and is limited to short time and length scales. In this presentation we used Core-modified dissipative particle dynamics (CM-DPD) with modified depletion potential, as a coarse-grain model, to address the gel formation process in short ranged-attractive colloidal suspensions. Due to the possibility to include and separate short and long ranged-hydrodynamic forces in this method we studied the effect of each of those forces on the final morphology and report one of the controversial question in this field on the effect of hydrodynamics on the cluster formation process on bimodal, soft-hard colloidal mixtures.

  2. Basin hydrodynamic system analysis - Focus on vertical leakage and hydraulic continuity

    NARCIS (Netherlands)

    Verweij, J.M.; Kunakbayeva, G.; Ghazaryan, L.

    2015-01-01

    The development of an extensive integrated pressure database since 2002 in combination with integrated approaches to characterize and interpret current basin hydrodynamic systems in the Netherlands have resulted in knowledge and understanding of spatial variations in hydrodynamic and pressure condit

  3. Analysis of the hydrodynamics of continuous flux systems using radioactive tracers

    CERN Document Server

    Vela, C R

    1996-01-01

    The hydrodynamic behaviour of a flux in a system can be determined through the knowledge and correct interpretation of age distributions of flux elements in a system, which can be obtained with the stimulus-response experimental method. This research attempts to emphasize the relevance of system analysis, as well as the use of radioactive tracers to determine residence time distributions when population balance models are used for such analysis. Hydrodynamics of a flux, water, is analyzed using different systems: i) piston flux system; ii) agitated tank system; iii) two agitated tank system in parallel; iv) two and four agitated tank system in series; and v) a complex system. Different age distributions are determined, as well as the presence of short circuits of different magnitude when system agitation speed is changed. Age distribution curves were built using I-131 radioisotope as tracer, injecting it into the flux inlet of the systems. A Minekin gamma radiation detector was used at the outlet of such syst...

  4. Balancing of Lossless and Passive Systems

    NARCIS (Netherlands)

    Schaft, Arjan van der

    2008-01-01

    Different balancing techniques are applied to lossless nonlinear systems, with open-loop balancing applied to their scattering representation. It is shown that they all lead to the same result: the pair of to-be-balanced functions is given by two copies of the physical energy function, yielding thus

  5. Balancing of Lossless and Passive Systems

    NARCIS (Netherlands)

    Schaft, Arjan van der

    2008-01-01

    Different balancing techniques are applied to lossless nonlinear systems, with open-loop balancing applied to their scattering representation. It is shown that they all lead to the same result: the pair of to-be-balanced functions is given by two copies of the physical energy function, yielding thus

  6. Single Switched Capacitor Battery Balancing System Enhancements

    Directory of Open Access Journals (Sweden)

    Joeri van Mierlo

    2013-04-01

    Full Text Available Battery management systems (BMS are a key element in electric vehicle energy storage systems. The BMS performs several functions concerning to the battery system, its key task being balancing the battery cells. Battery cell unbalancing hampers electric vehicles’ performance, with differing individual cell voltages decreasing the battery pack capacity and cell lifetime, leading to the eventual failure of the total battery system. Quite a lot of cell balancing topologies have been proposed, such as shunt resistor, shuttling capacitor, inductor/transformer based and DC energy converters. The shuttling capacitor balancing systems in particular have not been subject to much research efforts however, due to their perceived low balancing speed and high cost. This paper tries to fill this gap by briefly discussing the shuttling capacitor cell balancing topologies, focusing on the single switched capacitor (SSC cell balancing and proposing a novel procedure to improve the SSC balancing system performance. This leads to a new control strategy for the SSC system that can decrease the balancing system size, cost, balancing time and that can improve the SSC balancing system efficiency.

  7. Global regularity for generalized Hall magneto-hydrodynamics systems

    Directory of Open Access Journals (Sweden)

    Renhui Wan

    2015-06-01

    Full Text Available In this article, we consider the tridimensional generalized Hall magneto-hydrodynamics (Hall-MHD system, with $(-\\Delta^\\alpha u$ and $(-\\Delta^\\beta b$. For $\\alpha\\ge 5/4$, $\\beta\\ge 7/4$, we obtain the global regularity of classical solutions. For $0<\\alpha<5/4$ and $1/2<\\beta<7/4$, with small data, the system also possesses global classical solutions. In addition, for the standard Hall-MHD system, $\\alpha=\\beta=1$, by adding a suitable condition, we give a positive answer to the open question in [3]. At last, we study the regularity criterions of generalized Hall-MHD system. In particular, we prove the regularity criterion in terms of horizontal gradient $\

  8. Well-balanced and flexible morphological modeling of swash hydrodynamics and sediment transport

    CERN Document Server

    Hu, Peng; He, Zhiguo; Pähtz, Thomas; Yue, Zhiyuan

    2014-01-01

    Existing numerical models of the swash zone are relatively inflexible in dealing with sediment transport due to a high dependence of the deployed numerical schemes on empirical sediment transport relations. Moreover, these models are usually not well-balanced, meaning they are unable to correctly simulate quiescent flow. Here a well-balanced and flexible morphological model for the swash zone is presented. The nonlinear shallow water equations and the Exner equation are discretized by the shock-capturing finite volume method, in which the numerical flux and the bed slope source term are estimated by a well-balanced version of the SLIC (Slope LImited Centered) scheme that does not depend on empirical sediment transport relations. The satisfaction of the well-balanced property is demonstrated through simulating quiescent coastal flow. The quantitative accuracy of the model in reproducing key parameters (i.e., the notional shoreline position, the swash depth, the flow velocity, the overtopping flow volume, the b...

  9. Microprocessor-Controlled Laser Balancing System

    Science.gov (United States)

    Demuth, R. S.

    1985-01-01

    Material removed by laser action as part tested for balance. Directed by microprocessor, laser fires appropriate amount of pulses in correct locations to remove necessary amount of material. Operator and microprocessor software interact through video screen and keypad; no programing skills or unprompted system-control decisions required. System provides complete and accurate balancing in single load-and-spinup cycle.

  10. Hydrodynamics and transport in low-dimensional interacting systems

    Science.gov (United States)

    Kulkarni, Manas

    Recent ground-breaking experiments have realized strongly interacting quantum degenerate Fermi gas in a cold atomic system with tunable interactions. This has provided a table-top system which is extremely hydrodynamic in nature. This experimental realization helps us to investigate several aspects such as the interplay between nonlinearity, dissipation and dispersion. We find, for instance, that the dynamics in such a system shows near perfect agreement with a hydrodynamic theory. In collaboration with the group of John Thomas at Duke we interpreted studies of collision of two strongly interacting Fermi gases that led to shock waves which are a hallmark of nonlinear physics. Due to reasons such as the nature of interactions, higher dimensionality, these cold atomic systems are non-integrable and moreover the underlying field theory construction is mostly phenomenological in nature. On the other hand there are certain one-dimensional systems which are not only integrable but also facilitate more formal and rigorous ways of deriving the corresponding integrable field theories. One such family of models is the family of Calogero models (and their generalizations). They provide an extraordinary insight into the field of strongly correlated systems and hydrodynamics. We study the collective field theory of such models and address aspects of nonlinear physics such as Spin-Charge Interaction, Emptiness Formation Probability, Solitons etc; We derive a two-component nonlinear, nonlocal, integrable field theory. We also show that the Calogero family which is integrable even in an external harmonic trap (usually unavoidable in cold atom setups) is relatively "short ranged" thereby qualifying as a toy model for cold atom experiments. Transport in certain strongly correlated systems (impurity models) was studied using few low-dimensional techniques such as a 1/N diagrammatic expansion, Slave Boson Mean Field Theory and the Bethe Ansatz. A mesoscopic setup such as parallel

  11. Emergent hydrodynamics in integrable quantum systems out of equilibrium

    CERN Document Server

    Castro-Alvaredo, Olalla A; Yoshimura, Takato

    2016-01-01

    Understanding the general principles underlying strongly interacting quantum states out of equilibrium is one of the most important tasks of current theoretical physics. With experiments now able to access the intricate dynamics of many-body quantum systems, it is paramount to develop powerful and widely applicable methods that encode the emergent physics. Up to now, the strong dichotomy observed between integrable and non-integrable evolutions made an overarching theory difficult to build, especially for transport phenomena where space-time profiles show drastically different behaviours. We present a novel framework for studying transport in integrable systems: that of emergent hydrodynamics with infinitely-many conservation laws. This method bridges the conceptual gap between integrable and non-integrable quantum dynamics. We apply it to the description of energy transport between heat baths in interacting integrable systems. We provide for the first time a full description of the current-carrying non-equil...

  12. Underdamped modes in a hydrodynamically coupled microparticle system

    Science.gov (United States)

    Yao, A. M.; Keen, S. A. J.; Burnham, D. R.; Leach, J.; Leonardo, R. Di; McGloin, D.; Padgett, M. J.

    2009-05-01

    When micron-sized particles are trapped in a linear periodic array, for example, by using optical tweezers, they interact only through the hydrodynamic forces between them. This couples the motion of the spheres and it has been predicted that an extended system might behave as an elastic medium that could support underdamped propagating waves. In practice, these underdamped modes can be observed only with massive particles in very stiff traps and very low viscosity fluids. We have been able to realize these conditions by trapping water droplets in air. Even with a system of just two particles we were able to observe the coupled oscillatory motion predicted: underdamping of the symmetric (collective) mode and overdamping of the asymmetric (relative) mode.

  13. Transport in nanoscale systems: hydrodynamics, turbulence, and local electron heating

    Science.gov (United States)

    di Ventra, Massimiliano

    2007-03-01

    Transport in nanoscale systems is usually described as an open-boundary scattering problem. This picture, however, says nothing about the dynamical onset of steady states, their microscopic nature, or their dependence on initial conditions [1]. In order to address these issues, I will first describe the dynamical many-particle state via an effective quantum hydrodynamic theory [2]. This approach allows us to predict a series of novel phenomena like turbulence of the electron liquid [2], local electron heating in nanostructures [3], and the effect of electron viscosity on resistance [4]. I will provide both analytical results and numerical examples of first-principles electron dynamics in nanostructures using the above approach. I will also discuss possible experimental tests of our predictions. Work supported in part by NSF and DOE. [1] N. Bushong, N. Sai and M. Di Ventra, ``Approach to steady-state transport in nanoscale systems'' Nano Letters, 5 2569 (2005); M. Di Ventra and T.N. Todorov, ``Transport in nanoscale systems: the microcanonical versus grand-canonical picture,'' J. Phys. Cond. Matt. 16, 8025 (2004). [2] R. D'Agosta and M. Di Ventra, ``Hydrodynamic approach to transport and turbulence in nanoscale conductors,'' cond-mat/05123326; J. Phys. Cond. Matt., in press. [3] R. D'Agosta, N. Sai and M. Di Ventra, ``Local electron heating in nanoscale conductors,'' cond-mat/0605312; Nano Letters, in press. [4] N. Sai, M. Zwolak, G. Vignale and M. Di Ventra, ``Dynamical corrections to the DFT-LDA electron conductance in nanoscale systems,'' Phys. Rev. Lett. 94, 186810 (2005).

  14. The Quantum Hydrodynamics System in Two Space Dimensions

    KAUST Repository

    Antonelli, Paolo

    2011-09-16

    In this paper we study global existence of weak solutions for the quantum hydrodynamics system in two-dimensional energy space. We do not require any additional regularity and/or smallness assumptions on the initial data. Our approach replaces the WKB formalism with a polar decomposition theory which is not limited by the presence of vacuum regions. In this way we set up a self consistent theory, based only on particle density and current density, which does not need to define velocity fields in the nodal regions. The mathematical techniques we use in this paper are based on uniform (with respect to the approximating parameter) Strichartz estimates and the local smoothing property. © 2011 Springer-Verlag.

  15. Optical Electronic Bragg Reflection Sensor System with Hydrodynamic Flow Applications

    Science.gov (United States)

    Lyons, D. R.

    2003-01-01

    This project, as described in the following report, involved design and fabrication of fiber optic sensors for the detection and measurement of dynamic fluid density variations. These devices are created using UV (ultraviolet) ablation and generally modified transverse holographic fiber grating techniques. The resulting phase gratings created on or immediately underneath the flat portion of D-shaped optical waveguides are characterized as evanescent field sensing devices. The primary applications include the sensor portion of a real-time localized or distributed measurement system for hydrodynamic flow, fluid density measurements, and phase change phenomena. Several design modifications were implemented in an attempt to accomplish the tasks specified in our original proposal. In addition, we have established key collaborative relationships with numerous people and institutions.

  16. Numerical Analysis of Combined Valve Hydrodynamic Characteristics for Turbine System

    Energy Technology Data Exchange (ETDEWEB)

    Bhowmik, P. K.; Shamim, J. A.; Gairola, A.; Arif, M.; Suh, Kune Y. [Seoul National Univ., Seoul (Korea, Republic of)

    2014-05-15

    precisely by the valve manufacturer. As a matter of fact, attempts were made to obtain flow characteristic curves resorting to analytical as well as numerical methods. The flow characteristic curve relates the stem lift with mass flow rate at a specific temperature and pressure. This paper focuses on computational and numerical analysis of the combined stop and control valve. Combined Airflow Regulation Analysis (CARA) is performed to check on the hydrodynamic characteristic, which is represented by flow coefficient characteristic. CATIA V.5 and ANSYS CFX are used for three-dimensional computer-aided design and computational fluid dynamics (CFD) analysis, respectively. Flow characteristic curves are plotted by calculating theoretical and numerical mass flow rate. Hydrodynamic analysis was made of the combined stop and control valve for the turbine system using ANSYS CFX. The result of the numerical study represented by the valve flow coefficient with different normalized values of valve stem movement L/D and different pressure ratios of valve outlet and inlet agrees well with the ideal case and other similar previous experimental results. This study also provided a solid understanding with versatile options for analyzing the hydrodynamics of the combined valve considering the various internal geometry, seat, plug, and the inlet plus outlet boundary conditions to improve the efficiency, performance and reliability of the turbine system of small as well as large power conversion system using the numerical analysis with minimal cost and time.

  17. On balanced truncation for symmetric nonlinear systems

    NARCIS (Netherlands)

    Fujimoto, K.; Scherpen, Jacqueline M.A.

    2014-01-01

    This paper is concerned with model order reduction based on balanced realization for symmetric nonlinear systems. A new notion of symmetry for nonlinear systems was characterized recently. It plays an important role in linear systems theory and is expected to provide new insights to nonlinear system

  18. Flood hazards analysis based on changes of hydrodynamic processes in fluvial systems of Sao Paulo, Brazil.

    Science.gov (United States)

    Simas, Iury; Rodrigues, Cleide

    2016-04-01

    The metropolis of Sao Paulo, with its 7940 Km² and over 20 million inhabitants, is increasingly being consolidated with disregard for the dynamics of its fluvial systems and natural limitations imposed by fluvial terraces, floodplains and slopes. Events such as floods and flash floods became particularly persistent mainly in socially and environmentally vulnerable areas. The Aricanduva River basin was selected as the ideal area for the development of the flood hazard analysis since it presents the main geological and geomorphological features found in the urban site. According to studies carried out by Anthropic Geomorphology approach in São Paulo, to study this phenomenon is necessary to take into account the original hydromorphological systems and its functional conditions, as well as in which dimensions the Anthropic factor changes the balance between the main variables of surface processes. Considering those principles, an alternative model of geographical data was proposed and enabled to identify the role of different driving forces in terms of spatial conditioning of certain flood events. Spatial relationships between different variables, such as anthropogenic and original morphology, were analyzed for that purpose in addition to climate data. The surface hydrodynamic tendency spatial model conceived for this study takes as key variables: 1- The land use present at the observed date combined with the predominant lithological group, represented by a value ranging 0-100, based on indexes of the National Soil Conservation Service (NSCS-USA) and the Hydraulic Technology Center Foundation (FCTH-Brazil) to determine the resulting balance of runoff/infiltration. 2- The original slope, applying thresholds from which it's possible to determine greater tendency for runoff (in percents). 3- The minimal features of relief, combining the curvature of surface in plant and profile. Those three key variables were combined in a Geographic Information System in a series of

  19. Momentum balance, hydrodynamic impulse and choreography in rapidly maneuvering live fish

    Science.gov (United States)

    Epps, B. P.; Techet, A. H.

    2006-11-01

    It is well known that swimming fish can swim circles around underwater vehicles when it comes to maneuvering performance. A typical underwater vehicle sweeps a circular arc, about ten vehicle lengths in diameter, and this requires about 15 times the amount of time it takes for the vehicle to drive one body length. In contrast, a fish, such as the Danio aequipinnatus, can turn in a space that is approximately one third of its body length, and it requires about half the time it takes to swim one body length. High-speed Particle Imaging Velocimetry (PIV) is used to quantify the impulse imparted to the fluid during a maneuver which is compared to the change in momentum of the fish during the maneuver. In order to model the impulse of the fluid, we make the assumption that the wake may be modeled as an axisymmetric vortex ring. The evidence that this is an appropriate model comes from a recent study of rapidly maneuvering flapping foils. Our PIV results show that the fish in fact generates two such wakes, one generated by the tail and shed at the conclusion of stage one of the maneuver and the other generated by the mid-section of the body and shed at the conclusion of stage two of the maneuver. Both of these vertical impulses are required to balance the momentum change of the fish from its initial swimming trajectory to its final swimming trajectory in a classical C-shaped maneuver.

  20. Efficacy of virtual reality-based balance training versus the Biodex balance system training on the body balance of adults

    OpenAIRE

    Ibrahim, Manal S.; Mattar, Ayman G.; Elhafez, Salam M.

    2016-01-01

    [Purpose] This study investigated efficacy of virtual reality (VR)-based balance training on enhancing balance and postural reactions of adults as a low-cost new modality compared to the established Biodex Balance System (BBS). [Subjects] Thirty normal adults of both genders were divided randomly into two equal-sized experimental groups of 15: BBS balance training and VR balance training. [Methods] The training programmes were conducted in 12 sessions, three 15-min sessions per week. The Nint...

  1. Balanced truncation for linear switched systems

    DEFF Research Database (Denmark)

    Petreczky, Mihaly; Wisniewski, Rafal; Leth, John-Josef

    2013-01-01

    in this paper, we provide a bound on the approximation error in the L2L2 norm for continuous-time and the l2l2 norm for discrete-time linear switched systems. We provide a system theoretic interpretation of grammians and their singular values. Furthermore, we show that the performance of balanced truncation...

  2. Balanced truncation for linear switched systems

    DEFF Research Database (Denmark)

    Petreczky, Mihaly; Wisniewski, Rafal; Leth, John-Josef

    2013-01-01

    in this paper, we provide a bound on the approximation error in the L2L2 norm for continuous-time and the l2l2 norm for discrete-time linear switched systems. We provide a system theoretic interpretation of grammians and their singular values. Furthermore, we show that the performance of balanced truncation...

  3. Balanced bridge feedback control system

    Science.gov (United States)

    Lurie, Boris J. (Inventor)

    1990-01-01

    In a system having a driver, a motor, and a mechanical plant, a multiloop feedback control apparatus for controlling the movement and/or positioning of a mechanical plant, the control apparatus has a first local bridge feedback loop for feeding back a signal representative of a selected ratio of voltage and current at the output driver, and a second bridge feedback loop for feeding back a signal representative of a selected ratio of force and velocity at the output of the motor. The control apparatus may further include an outer loop for feeding back a signal representing the angular velocity and/or position of the mechanical plant.

  4. Influence of the Aral Sea negative water balance on its seasonal circulation patterns: use of a 3D hydrodynamic model

    Science.gov (United States)

    Sirjacobs, D.; Grégoire, M.; Delhez, E.; Nihoul, J. C. J.

    2004-06-01

    A 3D hydrodynamic model of the Aral Sea was successfully implemented to address the complex hydrodynamic changes induced by the combined effect of hydrologic and climatic change in the Aral region. The first barotropic numerical experiments allowed us to produce a comparative description of the mean general seasonal circulation patterns corresponding to the original situation (1956-1960) and of the average situation for the period from 1981 to 1985, a very low river flow period. The dominant anticyclonic circulation suggested by our seasonal simulation is in good agreement with previous investigations. In addition, this main anticyclonic gyre was shown to be stable and clearly established from February to September, while winter winds led to another circulation scenario. In winter, the main anticyclonic gyre was considerably limited, and cyclonic circulations appeared in the deep western basin and in the northeast of the shallow basin. In contrast, stronger anticyclonic circulation was observed in the Small Aral Sea during winter. As a consequence of the 10-m sea level drop observed between the two periods considered, the 1981-1985 simulation suggests an intensification of seasonal variability. Total water transport of the main gyre was reduced with sea level drop by a minimum of 30% in May and up to 54% in September. Before 1960, the study of the net flows through Berg and Kokaral Straits allowed us to evaluate the component of water exchange between the Small and the Large Seas linked with the general anticyclonic circulation around Kokaral Island. This exchange was lowest in summer (with a mean anticyclonic exchange of 222 m 3/s for July and August), highest in fall and winter (with a mean value of 1356 m 3/s from September to February) and briefly reversed in the spring (mean cyclonic circulation of 316 m 3/s for April and May). In summer, the water exchange due to local circulation at the scale of each strait was comparatively more important because net flows

  5. Verification and Validation of the Coastal Modeling System. Report 3: CMS-Flow: Hydrodynamics

    Science.gov (United States)

    2011-12-01

    ER D C/ CH L TR -1 1- 10 Verification and Validation of the Coastal Modeling System Report 3, CMS -Flow: Hydrodynamics Co as ta l a nd...11-10 December 2011 Verification and Validation of the Coastal Modeling System Report 3, CMS -Flow: Hydrodynamics Alejandro Sánchez, Weiming Wu...of four reports toward the Verification and Validation (V&V) of the Coastal Modeling System ( CMS ). The details of the V&V study specific to the

  6. Phase balancing optimization for radial feeder systems

    Science.gov (United States)

    Zhu, Jinxiang

    In the power distribution systems, unbalanced feeder causes deteriorating power quality and increases investment and operating costs. There are two approaches to balance a feeder system. One approach is feeder reconfiguration, the other is phase swapping. Feeder reconfiguration is an on-line operation of sectionalizing switches. However, feeder reconfiguration is difficult to find the phase balancing solution for a unbalanced feeder system. On the other hand, phase swapping is a direct and effective approach for phase balancing. Phase swapping is an off-line operation of re-tapping loads/laterals to the phase lines during maintenance and restoration periods. Unfortunately, phase balancing problem has not received its deserved importance. Deregulation in power industry has arisen phase balancing issue because it can improve power quality, improve service reliability, and reduce total costs. Thus, phase balancing can enhance utility competitive capability. This research provides utilities the optimization tools to maximize the benefits of phase balancing and minimize the costs. This dissertation proposed several mathematical formulations, including Mixed-integer programming (MIP), Dynamic programming (DP), Simulated annealing (SA), and Fuzzy logic (FL), to perform phase swapping to balance phase in a radial feeder. Due to the discrete nature of phase swapping, a MIP model is proposed to find the optimal phase swapping scheme for small-sized feeder. Candidate sets and monitored branches are then introduced to solve the large-scale feeder systems. Possibilistic integer programming (PIP) is proposed to incorporate load uncertainties in phase swapping problems. The tests show that the load uncertainties may change the optimal phase swapping. DP computation is significant reduced by introducing the tighter upper/lower bounds. The upper bound can be quickly obtained by assignment algorithm. Even though SA is a time-consuming heuristic method, it can provide better solution

  7. On-chip separation and sensing systems for hydrodynamic chromatography

    NARCIS (Netherlands)

    Blom, M.T.

    2002-01-01

    The feasibility of on-chip analytical separations using planar hydrodynamic chromatography (HDC) in Pyrex-silicon and fused silica chips has been demonstrated. In order to sketch the analytical separations area in which the HDC chip has to operate, an introduction was given of important macro-scale

  8. Lattice hydrodynamic model based traffic control: A transportation cyber-physical system approach

    Science.gov (United States)

    Liu, Hui; Sun, Dihua; Liu, Weining

    2016-11-01

    Lattice hydrodynamic model is a typical continuum traffic flow model, which describes the jamming transition of traffic flow properly. Previous studies in lattice hydrodynamic model have shown that the use of control method has the potential to improve traffic conditions. In this paper, a new control method is applied in lattice hydrodynamic model from a transportation cyber-physical system approach, in which only one lattice site needs to be controlled in this control scheme. The simulation verifies the feasibility and validity of this method, which can ensure the efficient and smooth operation of the traffic flow.

  9. Investigation on the Hydrodynamic Performance of An Ultra Deep Turret-Moored FLNG System

    Institute of Scientific and Technical Information of China (English)

    ZHAO Wen-hua; YANG Jian-min; HU Zhi-qiang; XIAO Long-fei; PENG Tao

    2012-01-01

    Hydrodynamic performance of an ultra deep turret-moored Floating Liquefied Natural Gas (FLNG) system is investigated.Hydrodynamic modeling of a turret-moored FLNG system,in consideration of the coupling effects of the vessel and its mooring lines,has been addressed in details.Based on the boundary element method,a 3-D panel model of the FLNG vessel and the related free water surface model are established,and the first-order and second-order mean-drift wave loads and other hydrodynamic coefficients are calculated.A systematic model test program consisting of the white noise wave test,offset test and irregular wave test combined with current and wind,etc.is performed to verify the numerical model.Owing to the depth limit of the water basin,the model test is carried out for the hydrodynamics of the FLNG coupled with only the truncated mooring system.The numerical simulation model features well the hydrodynamic performance of the FLNG system obtained from the model tests.The hydrodynamic characteristics presented in both the numerical simulations and the physical model tests would serve as the guidance for the ongoing project of FLNG system.

  10. Experimental Study and System Identification of Hydrodynamic Force Acting on Heave Damping Plate

    Institute of Scientific and Technical Information of China (English)

    JI Heng-teng; FAN Ju; HUANG Xiang-lu

    2008-01-01

    Although Morison equation is often applied for simulating hydrodynamic force of marine structure, it may give poor results when non-linear behavior is severe or random wave is encountered. This leads to some modifications of Morison equation or other methods for predicting hydrodynamic force. One of them is the system identification technique. In this paper, NARMAX model theory is firstly used to identify the hydrodynamic system of heave damping plates, which are commonly installed on spar platform. Both linear and non-linear models are obtained. The comparisons between the predicted results and measured data indicate that NARMAX model can predict hydrodynamic force of a heave damping plate very well. The measured data for identification originate from forced oscillation tests, which are random records with given spectrum. The forced oscillation forms in experiment also contain simple harmonic, multi-frequency ones.

  11. The Dynamic Balancer electrical safety systems

    Energy Technology Data Exchange (ETDEWEB)

    Konkel, H.

    1997-12-01

    The Pantex Plant Dynamic Balancer is used to identify physical imbalance in some weapon systems. This study was conducted at the request of the US Department of Energy/Albuquerque Operations Office (USDOE/AL) Dynamic Balancer Project Team to identify the electrical conditions required for motor over-speed to occur and to discuss the functions of the various electrical protective features associated with the Dynamic Balancer (DB). As is shown through the development of a fault tree, numerous electrical and human failures are required for over-speed conditions to occur. As directed by the Project Team, no effort was made to develop detailed fault trees for all electrical systems, to quantify basic events in the fault tree, or to develop accident scenarios leading to or resulting from over-speed. The Pantex Building 12-60, Bay 2, facility electrical circuits and grounding are described, and potential hazards are discussed. DB motor over-speed is a safety concern, and therefore, the controls that limit this condition are described and discussed in detail. Other safety-significant electrical circuits are discussed as well. These safety systems also are described in the facility Basis for Interim Operation. A potential for a motor over-speed that is not sensed by the standard safety protective systems does exist. This fault pathway is discussed, and recommendations to mitigate its effect are made.

  12. Dispersive deformations of hydrodynamic reductions of (2 + 1)D dispersionless integrable systems

    Science.gov (United States)

    Ferapontov, E. V.; Moro, A.

    2009-01-01

    We demonstrate that hydrodynamic reductions of dispersionless integrable systems in 2 + 1 dimensions, such as the dispersionless Kadomtsev-Petviashvili (dKP) and dispersionless Toda lattice (dTl) equations, can be deformed into reductions of the corresponding dispersive counterparts. Modulo the Miura group, such deformations are unique. The requirement that any hydrodynamic reduction possesses a deformation of this kind imposes strong constraints on the structure of dispersive terms, suggesting an alternative approach to the integrability in 2 + 1 dimensions.

  13. Efficacy of virtual reality-based balance training versus the Biodex balance system training on the body balance of adults.

    Science.gov (United States)

    Ibrahim, Manal S; Mattar, Ayman G; Elhafez, Salam M

    2016-01-01

    [Purpose] This study investigated efficacy of virtual reality (VR)-based balance training on enhancing balance and postural reactions of adults as a low-cost new modality compared to the established Biodex Balance System (BBS). [Subjects] Thirty normal adults of both genders were divided randomly into two equal-sized experimental groups of 15: BBS balance training and VR balance training. [Methods] The training programmes were conducted in 12 sessions, three 15-min sessions per week. The Nintendo(®) Wii Fit Plus (NWFP) and its balance board were used to train of the VR group. Each participant answered a questionnaire concerning usability, enjoyment, balance improvement, and fatigue at the end of the training programs. [Results] The study found a significant increase the measure of mean overall balance (OLB) in both groups. No significant difference was found between the groups, but a significant decrease in the mean balance-test time was found for both groups, with no significant difference between the two training methods. The VR programme was rated highly enjoyable by 81.8% of the group. [Conclusion] The Wii Fit Plus system with the balance board as a new VR balance-training technique, can be considered an effective and enjoyable tool for the training of adults' body balance.

  14. Model Reduction for Nonlinear Systems by Incremental Balanced Truncation

    NARCIS (Netherlands)

    Besselink, Bart; van de Wouw, Nathan; Scherpen, Jacquelien M. A.; Nijmeijer, Henk

    2014-01-01

    In this paper, the method of incremental balanced truncation is introduced as a tool for model reduction of nonlinear systems. Incremental balanced truncation provides an extension of balanced truncation for linear systems towards the nonlinear case and differs from existing nonlinear balancing tech

  15. Model Reduction for Nonlinear Systems by Incremental Balanced Truncation

    NARCIS (Netherlands)

    Besselink, Bart; van de Wouw, Nathan; Scherpen, Jacquelien M. A.; Nijmeijer, Henk

    2014-01-01

    In this paper, the method of incremental balanced truncation is introduced as a tool for model reduction of nonlinear systems. Incremental balanced truncation provides an extension of balanced truncation for linear systems towards the nonlinear case and differs from existing nonlinear balancing tech

  16. Surface Energy Balance System (SEBS) Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Cook, D. R. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-01-01

    A Surface Energy Balance System (SEBS) has been installed collocated with each deployed Eddy Correlation Flux Measurement System (ECOR) at the Atmospheric Radiation Measurement (ARM) Climate Research Facility’s Southern Great Plains (SGP) site, North Slope of Alaska (NSA) site, first ARM Mobile Facility (AMF1), second ARM Mobile Facility (AMF2), and third ARM Mobile Facility (AMF3) at Oliktok Point (OLI). A SEBS was also deployed with the Tropical Western Pacific (TWP) site, before it was decommissioned. Data from these sites, including the retired TWP, are available in the ARM Data Archive. The SEBS consists of upwelling and downwelling solar and infrared radiometers within one net radiometer, a wetness sensor, and soil measurements. The SEBS measurements allow the comparison of ECOR sensible and latent heat fluxes with the energy balance determined from the SEBS and provide information on wetting of the sensors for data quality purposes.

  17. Battery Cell Balancing System and Method

    Science.gov (United States)

    Davies, Francis J. (Inventor)

    2014-01-01

    A battery cell balancing system is operable to utilize a relatively small number of transformers interconnected with a battery having a plurality of battery cells to selectively charge the battery cells. Windings of the transformers are simultaneously driven with a plurality of waveforms whereupon selected battery cells or groups of cells are selected and charged. A transformer drive circuit is operable to selectively vary the waveforms to thereby vary a weighted voltage associated with each of the battery cells.

  18. Accounting balance sheet as a system

    Directory of Open Access Journals (Sweden)

    Lukin Vladimir

    2016-04-01

    Full Text Available The article actualizes the need to study the systematic approach and accountants’ systematical thinking based on the analysis of the systems theory basic provisions, the applicability of the system properties to the "balance sheet" category and to explore the basic tenets of the existing schools of accounting. It is proved that the accounting is a complex socio-technical system; justified that the study of accounting from the perspective of a systematic approach will enable a better understanding of its structure, principles of functioning and the role of an accountant in its practical implementation.

  19. Balancing Hydronic Systems in Multifamily Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Ruch, Russell [Partnership for Advanced Residential Retrofit, Chicago, IL (United States); Ludwig, Peter [Partnership for Advanced Residential Retrofit, Chicago, IL (United States); Maurer, Tessa [Partnership for Advanced Residential Retrofit, Chicago, IL (United States)

    2014-07-01

    In multifamily hydronic systems, temperature imbalance may be caused by undersized piping, improperly adjusted balancing valves, inefficient water temperature and flow levels, and owner/occupant interaction with the boilers, distribution, and controls. The imbalance leads to tenant discomfort, higher energy use intensity, and inefficient building operation. This research, conducted by Building America team Partnership for Advanced Residential Retrofit, explores cost-effective distribution upgrades and balancing measures in multifamily hydronic systems, providing a resource to contractors, auditors, and building owners on best practices to improve tenant comfort and lower operating costs. The team surveyed existing knowledge on cost-effective retrofits for optimizing distribution in typical multifamily hydronic systems, with the aim of identifying common situations and solutions, and then conducted case studies on two Chicago area buildings with known balancing issues in order to quantify the extent of temperature imbalance. At one of these buildings a booster pump was installed on a loop to an underheated wing of the building. This study found that unit temperature in a multifamily hydronic building can vary as much as 61°F, particularly if windows are opened or tenants use intermittent supplemental heating sources like oven ranges. Average temperature spread at the building as a result of this retrofit decreased from 22.1°F to 15.5°F.

  20. Balancing Hydronic Systems in Multifamily Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Ruch, R.; Ludwig, P.; Maurer, T.

    2014-07-01

    In multifamily hydronic systems, temperature imbalance may be caused by undersized piping, improperly adjusted balancing valves, inefficient water temperature and flow levels, and owner/occupant interaction with the boilers, distribution and controls. The effects of imbalance include tenant discomfort, higher energy use intensity and inefficient building operation. This paper explores cost-effective distribution upgrades and balancing measures in multifamily hydronic systems, providing a resource to contractors, auditors, and building owners on best practices to improve tenant comfort and lower operating costs. The research was conducted by The Partnership for Advanced Residential Retrofit (PARR) in conjunction with Elevate Energy. The team surveyed existing knowledge on cost-effective retrofits for optimizing distribution in typical multifamily hydronic systems, with the aim of identifying common situations and solutions, and then conducted case studies on two Chicago area buildings with known balancing issues in order to quantify the extent of temperature imbalance. At one of these buildings a booster pump was installed on a loop to an underheated wing of the building. This study found that unit temperature in a multifamily hydronic building can vary as much as 61 degrees F, particularly if windows are opened or tenants use intermittent supplemental heating sources like oven ranges. Average temperature spread at the building as a result of this retrofit decreased from 22.1 degrees F to 15.5 degrees F.

  1. Transcribing the balanced scorecard into system dynamics

    DEFF Research Database (Denmark)

    Nielsen, Steen; Nielsen, Erland Hejn

    2013-01-01

    the cause-and-effect relationships of an integrated BSC model. Including dynamic aspects of BSCs into the discussion is only in its infancy, so the aim of our work is also to contribute to both scholars’ and practitioners’ general understanding of how such delayed dynamic effects propagate through system......The purpose of this paper is to show how a System Dynamics Modelling approach can be integrated into the Balanced Scorecard (BSC) for a case company with special focus on the handling of causality in a dynamic perspective. The BSC model includes five perspectives and a number of financial and non...

  2. A consistent description of kinetics and hydrodynamics of quantum Bose-systems

    Directory of Open Access Journals (Sweden)

    P.A.Hlushak

    2004-01-01

    Full Text Available A consistent approach to the description of kinetics and hydrodynamics of many-Boson systems is proposed. The generalized transport equations for strongly and weakly nonequilibrium Bose systems are obtained. Here we use the method of nonequilibrium statistical operator by D.N. Zubarev. New equations for the time distribution function of the quantum Bose system with a separate contribution from both the kinetic and potential energies of particle interactions are obtained. The generalized transport coefficients are determined accounting for the consistent description of kinetic and hydrodynamic processes.

  3. Casimir and hydrodynamic force influence on microelectromechanical system actuation in ambient conditions

    NARCIS (Netherlands)

    Sedighi Ghozotkhar, Mehdi; Palasantzas, Georgios

    2014-01-01

    Casimir and hydrodynamic dissipation forces can strongly influence the actuation of microelectromechanical systems in ambient conditions. The dissipative and stiction dynamics of an actuating system is shown to depend on surface physical processes related to fluid slip and the size of the actuating

  4. Influence of hydrodynamic conditions on quantitative cellular assays in microfluidic systems.

    Science.gov (United States)

    Yin, Huabing; Zhang, Xunli; Pattrick, Nicola; Klauke, Norbert; Cordingley, Hayley C; Haswell, Stephen J; Cooper, Jonathan M

    2007-09-15

    This study demonstrates the importance of the hydrodynamic environment in microfluidic systems in quantitative cellular assays using live cells. Commonly applied flow conditions used in microfluidics were evaluated using the quantitative intracellular Ca2+ analysis of Chinese hamster ovary (CHO) cells as a model system. Above certain thresholds of shear stress, hydrodynamically induced intracellular Ca2+ fluxes were observed which mimic the responses induced by chemical stimuli, such as the agonist uridine 5'-triphosphate tris salt (UTP). This effect is of significance given the increasing application of microfluidic devices in high-throughput cellular analysis for biophysical applications and pharmacological screening.

  5. Hydrodynamic-type systems describing 2-dimensional polynomially integrable geodesic flows

    Science.gov (United States)

    Manno, Gianni; Pavlov, Maxim V.

    2017-03-01

    Starting from a homogeneous polynomial in momenta of arbitrary order we extract multi-component hydrodynamic-type systems which describe 2-dimensional geodesic flows admitting the initial polynomial as integral. All these hydrodynamic-type systems are semi-Hamiltonian, thus implying that they are integrable according to the generalized hodograph method. Moreover, they are integrable in a constructive sense as polynomial first integrals allow to construct generating equations of conservation laws. According to the multiplicity of the roots of the polynomial integral, we separate integrable particular cases.

  6. Transcribing the balanced scorecard into system dynamics

    DEFF Research Database (Denmark)

    Nielsen, Steen; Nielsen, Erland Hejn

    2013-01-01

    The purpose of this paper is to show how a System Dynamics Modelling approach can be integrated into the Balanced Scorecard (BSC) for a case company with special focus on the handling of causality in a dynamic perspective. The BSC model includes five perspectives and a number of financial and non......-financial measures. The overall idea of BSC is to make the strategy operational, as proposed by Kaplan and Norton (2007) and to use the strategy for simulation. Our results indicate that a company may gain great insight from simulation studies. The hypothesised model may be used as the first step in quantifying...... the cause-and-effect relationships of an integrated BSC model. Including dynamic aspects of BSCs into the discussion is only in its infancy, so the aim of our work is also to contribute to both scholars’ and practitioners’ general understanding of how such delayed dynamic effects propagate through system...

  7. Hydrodynamic Performance Analysis of Propeller-rudder System with the Rudder Parameters Changing

    Institute of Scientific and Technical Information of China (English)

    Lixun Hou; Chao Wang; Xin Chang; Sheng Huang

    2013-01-01

    In order to study the effects of geometric parameters of the rudder on the hydrodynamic performance of the propeller-rudder system, the surface panel method is used to build the numerical model of the steady interaction between the propeller and rudder to analyze the relevant factors. The interaction between the propeller and rudder is considered through the induced velocities, which are circumferentially averaged, so the unsteady problem is translated to steady state. An iterative calculation method is used until the hydrodynamic performance converges. Firstly, the hydrodynamic performance of the chosen propeller-rudder system is calculated, and the comparison between the calculated results and the experimental data indicates that the calculation program is reliable. Then, the variable parameters of rudder are investigated, and the calculation results show that the propeller-rudder spacing has a negative relationship with the efficiency of the propeller-rudder system, and the rudder span has an optimal match range with the propeller diameter. Futhermore, the rudder chord and thickness both have a positive correlation with the hydrodynamic performance of the propeller-rudder system.

  8. Dynamic balance of unsymmetrical rotor-bearing system

    Institute of Scientific and Technical Information of China (English)

    黄森林; 刘占生; 苏杰先

    2003-01-01

    The formula is derived for calculating correction weights from motion equations of unsymmetrical ro-tor-bearing system. Two trial weights are required in two trial operations for ea ch balancing plane, and forwardprecession of trial responses are used to calculate the correction weights. Comparative experiments between thismethod and the conventional method are carried out on the test bench. Moreover, this method was used to bal-ance a 600 MW generator-bearing system, it decreased the balancing time and improved the balance accuracy.This method has been proved valid for balancing unsymmetrical rotor-bearing system.

  9. BALANCE

    Science.gov (United States)

    Carmichael, H.

    1953-01-01

    A torsional-type analytical balance designed to arrive at its equilibrium point more quickly than previous balances is described. In order to prevent external heat sources creating air currents inside the balance casing that would reiard the attainment of equilibrium conditions, a relatively thick casing shaped as an inverted U is placed over the load support arms and the balance beam. This casing is of a metal of good thernnal conductivity characteristics, such as copper or aluminum, in order that heat applied to one portion of the balance is quickly conducted to all other sensitive areas, thus effectively preventing the fornnation of air currents caused by unequal heating of the balance.

  10. Comparative antibacterial efficacies of hydrodynamic and ultrasonic irrigation systems in vitro.

    Science.gov (United States)

    Cachovan, Georg; Schiffner, Ulrich; Altenhof, Saskia; Guentsch, Arndt; Pfister, Wolfgang; Eick, Sigrun

    2013-09-01

    To ensure root canal treatment success, endodontic microbiota should be efficiently reduced. The in vitro bactericidal effects of a hydrodynamic system and a passive ultrasonic irrigation system were compared. Single-rooted extracted teeth (n = 250) were contaminated with suspensions of Enterococcus faecalis ATCC 29212, mixed aerobic cultures, or mixed anaerobic cultures. First, the antibacterial effects of the hydrodynamic system (RinsEndo), a passive ultrasonic irrigation system (Piezo smart), and manual rinsing with 0.9% NaCl (the control) were compared. Colony-forming units were counted. Second, the 2 systems were used with 1.5% sodium hypochlorite (NaOCl) alone or NaOCl + 0.2% chlorhexidine (CHX). The colony-forming units in the treated and untreated roots were determined during a period of 5 days. Both irrigation systems reduced bacterial numbers more effectively than manual rinsing (P ultrasonic activated irrigation reduced bacterial counts significantly better than hydrodynamic irrigation (P = .042). The NaOCl + CHX combination was more effective than NaOCl alone for both systems (P ultrasonic irrigation system. Both irrigation systems, when combined with NaOCl + CHX, removed bacteria from root canals. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  11. Procedure for Balancing an Air Distribution System with Decentralised Fans

    DEFF Research Database (Denmark)

    Gunner, Amalie; Hultmark, Göran; Vorre, Anders;

    2015-01-01

    This paper presents results from an on-going project concerning new design procedures for mechanical ventilation systems with low energy use. Conventional constant air volume (CAV) systems are usually balanced using flat plate dampers. The purpose of using balancing dampers is to intentionally...... flawed. This paper presents a new procedure for balancing of CAV systems in combination with decentralised fans. The new system was based on replacing the balancing dampers with decentralised fans. By replacing the balancing dampers with decentralised fans, airflows can be balanced by adjusting the speed...... of the fans. In conventional air distribution systems the fan provides the necessary pressure to overcome the resistance in the branch with the highest pressure resistance. This gives an unnecessary overpressure in the remaining branches that does not provide any useful purpose. In order to decrease the fan...

  12. NREL Offshore Balance-of-System Model

    Energy Technology Data Exchange (ETDEWEB)

    Maness, Michael [National Renewable Energy Lab. (NREL), Golden, CO (United States); Maples, Benjamin [National Renewable Energy Lab. (NREL), Golden, CO (United States); Smith, Aaron [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-01-01

    The U.S. Department of Energy (DOE) has investigated the potential for 20% of nationwide electricity demand to be generated from wind by 2030 and, more recently, 35% by 2050. Achieving this level of wind power generation may require the development and deployment of offshore wind technologies. DOE (2008) has indicated that reaching these 2030 and 2050 scenarios could result in approximately 10% and 20%, respectively, of wind energy generation to come from offshore resources. By the end of 2013, 6.5 gigawatts of offshore wind were installed globally. The first U.S. project, the Block Island Wind Farm off the coast of Rhode Island, has recently begun operations. One of the major reasons that offshore wind development in the United States is lagging behind global trends is the high capital expenditures required. An understanding of the costs and associated drivers of building a commercial-scale offshore wind plant in the United States will inform future research and help U.S. investors feel more confident in offshore wind development. In an effort to explain these costs, the National Renewable Energy Laboratory has developed the Offshore Balance-of-System model.

  13. Derivation of second-order relativistic hydrodynamics for reactive multi-component systems

    CERN Document Server

    Kikuchi, Yuta; Kunihiro, Teiji

    2015-01-01

    We derive the second-order hydrodynamic equation for reactive multi-component systems from the relativistic Boltzmann equation. In the reactive system, particles can change their species under the restriction of the imposed conservation laws during the collision process. Our derivation is based on the renormalization group (RG) method, in which the Boltzmann equation is solved in an organized perturbation method as faithfully as possible and possible secular terms are resummed away by a suitable setting of the initial value of the distribution function. The microscopic formulae of the relaxation times and the lengths are explicitly given as well as those of the transport coefficients for the reactive multi-component system. The resultant hydrodynamic equation with these formulae has nice properties that it satisfies the positivity of the entropy production rate and the Onsager's reciprocal theorem, which ensure the validity of our derivation.

  14. Hydrodynamic coefficients of a simplified floating system of gravity cage in waves

    Institute of Scientific and Technical Information of China (English)

    Chang-wen WU; Fu-kun GUI; Yu-cheng LI; Wei-huan FANG

    2008-01-01

    Numerical simulation and experimental tests were carried out to examine the hydrodynamic behaviors of a double-column floating system of gravity cage under wave conditions. A floating system of gravity cage can be treated as a small-sized floating structure when compared with the wavelengths. The main problem in calculating the wave loads on the small-sized floating structure is to obtain the reasonable force coefficients, which may differ from a submerged structure. In this paper, the floating system of gravity cage is simplified to a 2D problem, where the floating system is set symmetrically under wave conditions. The motion equations were deduced under wave conditions and a specific method was proposed to resolve the problem of wave forces acting on a small-sized floating system of gravity cage at water surface. Results of the numerical method were compared with those from model tests and the hydrodynamic coefficients Cn and C?were studied. It is found that Cn ranges from 0.6 to 1.0 while C?is between 0.4 and 0.6 in this study. The results are useful for research on the hydrodynamic behavior of the deep-water gravity sea cages.

  15. Study on hydrodynamics associated with quality of water in water distribution system

    Institute of Scientific and Technical Information of China (English)

    李欣; 顾大明; 赵洪宾; 袁一星

    2002-01-01

    The quality of water in water distribution system may vary with both location and time. Water quality models were used to predict spatial and temporal variation of water quality throughout the water system. Before analyzing the variations of water quality, it is necessary to determine the hydrodynamics in water distribution system. Analytical methods for the flow path from water sources to the observed point and water age of every observed node are proposed. This paper makes a further study on water supply route of multi-sources water supply network system. These studies have been applied to an actual water distribution system.

  16. Hydrodynamic ion sound instability in systems of a finite length

    Science.gov (United States)

    Koshkarov, O.; Chapurin, O.; Smolyakov, A.; Kaganovich, I.; Ilgisonis, V.

    2016-09-01

    Plasmas permeated by an energetic ion beam is prone to the kinetic ion-sound instability that occurs as a result of the inverse Landau damping for ion velocity. It is shown here that in a finite length system there exists another type of the ion sound instability which occurs for v02 excitation of the lower-hybrid waves in Hall thruster. It is expected that this mechanism of ion sound and lower hybrid instabilities may be operative in E × B plasma discharges in which the ion beam is created by the application of the external voltage.

  17. INTEGRATION OF BALANCED SCORECARD AND QUALITY MANAGEMENT SYSTEM

    Directory of Open Access Journals (Sweden)

    Miroshnichenko M. A.

    2014-09-01

    Full Text Available The analysis and possibilities of use of the balanced scorecard for successful realization of corporate strategy are considered in this article. The most important results of research of integration of the quality management system in information system of the enterprise with use of the balanced scorecard are discussed

  18. Modeling hydrodynamics of large lagoons: Insights from the Albemarle-Pamlico Estuarine System

    Science.gov (United States)

    Clunies, Gregory J.; Mulligan, Ryan P.; Mallinson, David J.; Walsh, J. P.

    2017-04-01

    Large estuaries are influenced by winds over adjacent coastal ocean and land areas causing significant spatial variations in water levels, currents and surface waves. In this study we apply a numerical model to simulate hydrodynamics and waves in the Albemarle-Pamlico Estuarine System, a large and shallow back-barrier basin in eastern North Carolina, over a one-month study period (September 2008) with observations from several storm wind events of differing time scales and directions. Model performance is evaluated for a spatially varying wind field from the North American Regional Reanalysis (NARR) dataset in comparison to spatially uniform forcing from wind observations at offshore, coastal and land-based sites across the region. A spatially uniform wind field from offshore winds observations results in statistically better hydrodynamic simulations of water levels (R = 0.88) in the estuaries than NARR (R = 0.48) after comparison with measurements and indicates the importance of strong marine winds over most of the estuary surface area. The influence of a prominent bathymetric feature on hydrodynamics in Pamlico Sound is also investigated by numerically removing a 30 km long and 2-3 m deep shoal from the model grid and replacing it with an idealized depth of 6 m. The removal of the shoal increases water level setup by 14% at the estuarine shoreline, decreases current magnitudes by up to 40% in the shoal region and increases significant wave heights locally by up to 25% in the sound, indicating the importance of this relict geomorphic feature as a major control on the hydrodynamic response of the system during wind events. The results suggest that increasing the water depth over the shoal can lead to higher storm surges and wave heights with the possibility of increased inundation and erosion of the back-barrier and mainland coastal regions. The complex bathymetry and marine wind influence are critical input conditions for modeling large and shallow lagoonal

  19. Hydrodynamic behavior of a combined anaerobic-aerobic system employed in the treatment of vinasse

    Directory of Open Access Journals (Sweden)

    Fátima Resende Luiz Fia

    Full Text Available ABSTRACT The understanding of reactor hydrodynamics is essential for improving the performance of a reactor and biogas production. This study sought to evaluate the hydrodynamic behavior of a combined anaerobic-aerobic system at a laboratory scale for treating vinasse. The experiment was conducted in a system using two UASB reactors connected in series, followed by an Aerated Submerged Biological Filter (ASBF. The flow rates applied to the system and the corresponded theoretical HRTs in the UASB1, UASB2 and ASBF were respectively: 15.6 L d-1 and 1.2 d, 1.2 d and 1.0 d (Phase I - first year; 8.5 L d-1 and 2.1 d; 2.1 d and 1.8 d (Phase II - first year, 14.6 L d-1 and 1.1 d, 1.1 d and 1.0 d (Phase III - second year; 29.5 L d-1 and 0.6 d, 0.6 d and 0.5 d (Phase IV - second year. The hydrodynamic studies were carried out using pulse type stimulus-response tests, employing LiCl as a tracer. The coefficients of determination for the dispersion models (R2 indicate a close approximation of a continuous stirred tank reactor in series (multi-CSTR model, with an average of 2.5, 2.3 and 1.2 (first year, and 1.1, 1.4 and 0.9 (second year multi-CSTR for UASB1, UASB2 and ASBF, respectively. Results of the hydrodynamic tests carried out in UASB1, UASB2 and ASBF indicated strong tendency for flow in the complete mixture hydraulic regime, detecting a wide dispersion in the units, in addition to the presence of short circuits and dead zones.

  20. Hydrodynamic moving-mesh simulations of the common envelope phase in binary stellar systems

    CERN Document Server

    Ohlmann, Sebastian T; Pakmor, Ruediger; Springel, Volker

    2015-01-01

    The common envelope (CE) phase is an important stage in binary stellar evolution. It is needed to explain many close binary stellar systems, such as cataclysmic variables, Type Ia supernova progenitors, or X-ray binaries. To form the resulting close binary, the initial orbit has to shrink, thereby transferring energy to the primary giant's envelope that is hence ejected. The details of this interaction, however, are still not understood. Here, we present new hydrodynamic simulations of the dynamical spiral-in forming a CE system. We apply the moving-mesh code AREPO to follow the interaction of a $1M_\\odot$ compact star with a $2M_\\odot$ red giant possessing a $0.4M_\\odot$ core. The nearly Lagrangian scheme combines advantages of smoothed particle hydrodynamics and traditional grid-based hydrodynamic codes and allows us to capture also small flow features at high spatial resolution. Our simulations reproduce the initial transfer of energy and angular momentum from the binary core to the envelope by spiral shoc...

  1. Radiation Hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Castor, J I

    2003-10-16

    The discipline of radiation hydrodynamics is the branch of hydrodynamics in which the moving fluid absorbs and emits electromagnetic radiation, and in so doing modifies its dynamical behavior. That is, the net gain or loss of energy by parcels of the fluid material through absorption or emission of radiation are sufficient to change the pressure of the material, and therefore change its motion; alternatively, the net momentum exchange between radiation and matter may alter the motion of the matter directly. Ignoring the radiation contributions to energy and momentum will give a wrong prediction of the hydrodynamic motion when the correct description is radiation hydrodynamics. Of course, there are circumstances when a large quantity of radiation is present, yet can be ignored without causing the model to be in error. This happens when radiation from an exterior source streams through the problem, but the latter is so transparent that the energy and momentum coupling is negligible. Everything we say about radiation hydrodynamics applies equally well to neutrinos and photons (apart from the Einstein relations, specific to bosons), but in almost every area of astrophysics neutrino hydrodynamics is ignored, simply because the systems are exceedingly transparent to neutrinos, even though the energy flux in neutrinos may be substantial. Another place where we can do ''radiation hydrodynamics'' without using any sophisticated theory is deep within stars or other bodies, where the material is so opaque to the radiation that the mean free path of photons is entirely negligible compared with the size of the system, the distance over which any fluid quantity varies, and so on. In this case we can suppose that the radiation is in equilibrium with the matter locally, and its energy, pressure and momentum can be lumped in with those of the rest of the fluid. That is, it is no more necessary to distinguish photons from atoms, nuclei and electrons, than it is

  2. A Dynamic Load Balancing Mechanism for Distributed Systems

    Institute of Scientific and Technical Information of China (English)

    蓝有然

    1996-01-01

    It is desirable in a distributed system to have the system load balanced evenly among the nodes so that the mean job response time is minimized.In this paper,we present a dynamic load balancing mechanism(DLB).It adopts a cntralized approach and is network topology independent.The DLB mechanism employs a set of threscholds which are automatically adjusted as the system load changes.It also provides a simple mechanism for the system to switch between periodic and instantaneous load balancing policies with ease.The performance of the proposed algorithm is evaluated by intensive simulations for various parameters.Te simulation results show that the mean job response time in a system implementing DLB algorithm is significantly lower than the same system without load balancings.Furthermore,compared with a previously proposed algorithm,DLB algorithm demonstrates improved performance,especially when the system is heavily loaded and the load is unevenly distributed.

  3. Comparing Two Numerical Models in Simulating Hydrodynamics and Sediment Transport at a Dual Inlet System, West-Central Florida

    Science.gov (United States)

    2015-05-15

    1 COMPARING TWO NUMERICAL MODELS IN SIMULATING HYDRODYNAMICS AND SEDIMENT TRANSPORT AT A DUAL INLET SYSTEM, WEST-CENTRAL FLORIDA PING WANG1...numerical modeling systems, CMS and DELFT3D, in simulating the hydrodynamic and sediment transport processes. The model results are compared with...Introduction Simulating complex fields of wave, current, sediment transport , and morphology change in the vicinity of tidal inlets is a

  4. Energy-Storage Balanced Reduction of Port-Hamiltonian Systems

    NARCIS (Netherlands)

    Lopezlena, Ricardo; Scherpen, Jacquelien M.A.; Fujimoto, Kenji

    2003-01-01

    Supported by the framework of dissipativity theory, a procedure based on physical energy to balance and reduce port-Hamiltonian systems with collocated inputs and outputs is presented. Additionally, some relations with the methods of nonlinear balanced reduction are exposed. Finally a structure-pres

  5. The brain endocannabinoid system in the regulation of energy balance.

    Science.gov (United States)

    Richard, Denis; Guesdon, Benjamin; Timofeeva, Elena

    2009-02-01

    The role played by the endocannabinoid system in the regulation of energy balance is currently generating a great amount of interest among several groups of investigators. This interest in large part comes from the urgent need to develop anti-obesity and anti-cachexia drugs around target systems (such as the endocannabinoid system), which appears to be genuinely involved in energy balance regulation. When activated, the endocannabinoid system favors energy deposition through increasing energy intake and reducing energy expenditure. This system is activated in obesity and following food deprivation, which further supports its authentic function in energy balance regulation. The cannabinoid receptor type 1 (CB1), one of the two identified cannabinoid receptors, is expressed in energy-balance brain structures that are also able to readily produce or inactivate N-arachidonoyl ethanolamine (anandamide) and 2-arachidonoylglycerol (2AG), the most abundantly formed and released endocannabinoids. The brain action of endocannabinoid system on energy balance seems crucial and needs to be delineated in the context of the homeostatic and hedonic controls of food intake and energy expenditure. These controls require the coordinated interaction of the hypothalamus, brainstem and limbic system and it appears imperative to unravel those interplays. It is also critical to investigate the metabolic endocannabinoid system while considering the panoply of functions that the endocannabinoid system fulfills in the brain and other tissues. This article aims at reviewing the potential mechanisms whereby the brain endocannabinoid system influences the regulation energy balance.

  6. Casimir and hydrodynamic force influence on microelectromechanical system actuation in ambient conditions

    Science.gov (United States)

    Sedighi, Mehdi; Palasantzas, George

    2014-02-01

    Casimir and hydrodynamic dissipation forces can strongly influence the actuation of microelectromechanical systems in ambient conditions. The dissipative and stiction dynamics of an actuating system is shown to depend on surface physical processes related to fluid slip and the size of the actuating components. Using phase change materials the Casimir force magnitude can be modulated via amorphous-crystalline phase transitions. The dissipative motion between amorphous coated phase change material components can be changed towards stiction upon crystallization and suitable choice of restoring spring constants. By contrast, amorphization can augment switching from stiction to dissipative dynamics.

  7. Balancing modern Power System with large scale of wind power

    DEFF Research Database (Denmark)

    Basit, Abdul; Altin, Müfit; Hansen, Anca Daniela

    2014-01-01

    Power system operators must ensure robust, secure and reliable power system operation even with a large scale integration of wind power. Electricity generated from the intermittent wind in large propor-tion may impact on the control of power system balance and thus deviations in the power system...... to be analysed with improved analytical tools and techniques. This paper proposes techniques for the active power balance control in future power systems with the large scale wind power integration, where power balancing model provides the hour-ahead dispatch plan with reduced planning horizon and the real time...... frequency in small or islanded power systems or tie line power flows in interconnected power systems. Therefore, the large scale integration of wind power into the power system strongly concerns the secure and stable grid operation. To ensure the stable power system operation, the evolving power system has...

  8. Balanced {C_4, C_5}-Quatrefoil Systems

    OpenAIRE

    USHIO, Kazuhiko

    2004-01-01

    In graph theory, the decomposition problems of graphs are very important topics. Various types of decompositions of many graphs can be seen in the literature of gaph theory. We give the necessary and sufficient condition for the existence of a balanced {C_4, C_5}-quatrefoil decomposition of K_n for each of (C_4, C_4, C_4, C_4)-quatrefoil, (C_4, C_4, C_4, C_5)-quatrefoil, (C_4, C_4, C_5, C_5)-quatrefoil, (C_4, C_5, C_5, C_5)-quatrefoil, and (C_5, C_5, C_5, C_5)-quatrefoil. These decompositions...

  9. NONLINEAR DYNAMIC CHARACTERISTICS OF HYDRODYNAMIC JOURNAL BEARING-FLEXIBLE ROTOR SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Lu Yanjun; Yu Lie; Liu Heng

    2005-01-01

    The nonlinear dynamic behaviors of flexible rotor system with hydrodynamic bearing supports are analyzed. The shaft is modeled by using the finite element method that takes the effect of inertia and shear into consideration. According to the nonlinearity of the hydrodynamic journal bearing-flexible rotor system, a modified modal synthesis technique with free-interface is represented to reduce degrees-of-freedom of model of the flexible rotor system. According to physical character of oil film, variational constrain approach is introduced to continuously revise the variational form of Reynolds equation at every step of dynamic integration and iteration. Fluid lubrication problem with Reynolds boundary is solved by the isoparametric finite element method without the increasing of computing efforts. Nonlinear oil film forces and their Jacobians are simultaneously calculated and -Newton-Floquet (PNF) method. A method, combining the predictor-corrector mechanism to the PNF method, is presented to calculate the bifurcation point of periodic motions to be subject to change of system parameters. The local stability and bifurcation behaviors of periodic motions are obtained by Floquet theory. The chaotic motions of the beating-rotor system are investigated by power spectrum.The numerical examples show that the scheme of this study saves computing efforts but also is of good precision.

  10. Use of the Microsoft Kinect system to characterize balance ability during balance training.

    Science.gov (United States)

    Lim, Dohyung; Kim, ChoongYeon; Jung, HoHyun; Jung, Dukyoung; Chun, Keyoung Jin

    2015-01-01

    The risk of falling increases significantly in the elderly because of deterioration of the neural musculature regulatory mechanisms. Several studies have investigated methods of preventing falling using real-time systems to evaluate balance; however, it is difficult to monitor the results of such characterizations in real time. Herein, we describe the use of Microsoft's Kinect depth sensor system to evaluate balance in real time. Six healthy male adults (25.5±1.8 years, 173.9±6.4 cm, 71.4±6.5 kg, and 23.6±2.4 kg/m(2)), with normal balance abilities and with no musculoskeletal disorders, were selected to participate in the experiment. Movements of the participants were induced by controlling the base plane of the balance training equipment in various directions. The dynamic motion of the subjects was measured using two Kinect depth sensor systems and a three-dimensional motion capture system with eight infrared cameras. The two systems yielded similar results for changes in the center of body mass (P>0.05) with a large Pearson's correlation coefficient of γ>0.60. The results for the two systems showed similarity in the mean lower-limb joint angle with flexion-extension movements, and these values were highly correlated (hip joint: within approximately 4.6°; knee joint: within approximately 8.4°) (0.400.05). Large differences with a low correlation were, however, observed for the lower-limb joint angle in relation to abduction-adduction and internal-external rotation motion (γKinect system in balance training by measuring changes in the center of body mass and flexion-extension movements of the lower limbs, but not abduction-adduction and internal-external rotation.

  11. A recurrence network approach to analyzing forced synchronization in hydrodynamic systems

    Science.gov (United States)

    Murugesan, Meenatchidevi; Zhu, Yuanhang; Li, Larry K. B.

    2016-11-01

    Hydrodynamically self-excited systems can lock into external forcing, but their lock-in boundaries and the specific bifurcations through which they lock in can be difficult to detect. We propose using recurrence networks to analyze forced synchronization in a hydrodynamic system: a low-density jet. We find that as the jet bifurcates from periodicity (unforced) to quasiperiodicity (weak forcing) and then to lock-in (strong forcing), its recurrence network changes from a regular distribution of links between nodes (unforced) to a disordered topology (weak forcing) and then to a regular distribution again at lock-in (strong forcing). The emergence of order at lock-in can be either smooth or abrupt depending on the specific lock-in route taken. Furthermore, we find that before lock-in, the probability distribution of links in the network is a function of the characteristic scales of the system, which can be quantified with network measures and used to estimate the proximity to the lock-in boundaries. This study shows that recurrence networks can be used (i) to detect lock-in, (ii) to distinguish between different routes to lock-in, and (iii) as an early warning indicator of the proximity of a system to its lock-in boundaries. This work was supported by the Research Grants Council of Hong Kong (Project No. 16235716 and 26202815).

  12. On the Existence of Hydrodynamic Instability in Single Diffusive Bottom Heavy Systems with Permeable Boundaries

    Indian Academy of Sciences (India)

    A K Gupta; R G Shandil

    2011-11-01

    We utilize the reformulated equations of the classical theory, as derived by Banerjee et al.(J. Math. Anal. Appl. 175 (1993) 458), to establish mathematically, the existence of hydrodynamic instability in single diffusive bottom heavy systems, when considered in the more general framework of the boundary conditions of the type specified by Beavers and Joseph (J. Fluid Mech. 30 (1967) 197), in the parameter regime $T_0_2>1$, where $T_0$ and 2 being some properly chosen mean temperature and coefficient of specific heat (at constant volume) variation due to temperature variation respectively.

  13. Information system quality in work-life balance

    Directory of Open Access Journals (Sweden)

    Sharmini Gopinathan

    2016-06-01

    Full Text Available This paper aims to look for the role information systems quality may play in work-life balance among Malaysian ICT employees. The results of this study will be useful in the development of new tools and technologies that are focused on ISQ dimensions primarily information system quality which can be helpful to devise suggestions to the ICT sector on matters pertaining to sustainable development/policy formulation with reference to achieving a good work-life balance. A total of 79 respondents’ views were analyzed using Partial Least Square (PLS to obtain the final results. The results showed that information quality and system quality has strong effect on work-life balance as compared to service quality which showed no relation to work-life balance.

  14. Modelling of Be Disks in Binary Systems Using the Hydrodynamic Code PLUTO

    Science.gov (United States)

    Cyr, I. H.; Panoglou, D.; Jones, C. E.; Carciofi, A. C.

    2016-11-01

    The study of the gas structure and dynamics of Be star disks is critical to our understanding of the Be star phenomenon. The central star is the major force driving the evolution of these disks, however other external forces may also affect the formation of the disk, for example, the gravitational torque produced in a close binary system. We are interested in understanding the gravitational effects of a low-mass binary companion on the formation and growth of a disk in a close binary system. To study these effects, we used the grid-based hydrodynamic code PLUTO. Because this code has not been used to study such systems before, we compared our simulations against codes used in previous work on binary systems. We were able to simulate the formation of a disk in both an isolated and binary system. Our current results suggest that PLUTO is in fact a well suited tool to study the dynamics of Be disks.

  15. Seasonal evolution of the Yellow Sea Cold Water Mass and its interactions with ambient hydrodynamic system

    Science.gov (United States)

    Li, Jianchao; Li, Guangxue; Xu, Jishang; Dong, Ping; Qiao, Lulu; Liu, Shidong; Sun, Pingkuo; Fan, Zhisong

    2016-09-01

    The Yellow Sea Cold Water Mass (YSCWM) is an important component of the hydrodynamic system in the South Yellow Sea (SYS). However, its intricate interactions with the ambient flows over long time scales are not fully understood. This paper presents the analysis of the data set obtained from a seabed-mounted Acoustic Doppler Current Profiler (ADCP) deployed for nearly 1 year in the western SYS. It allowed us to study the evolution of YSCWM, including the seasonal changes of tidal currents, near-inertial oscillations (NIOs), and the wind-driven currents due to typhoons and winter storms. Strong NIOs were found near the bottom of mixed layer and in the pycnocline with nearly opposite current directions, with maximum velocity of nearly 20 cm·s-1 in summer. The YSCWM can also inhibit the direct downward energy transport in the water column due to typhoons. Conversely, the hydrodynamic system also feeds back to influence the change of YSCWM. A large current shear (S) of 20 cm·s-1·m-1 is generated near the top of pycnocline. Generally, the intensity and depth of the pycnocline determine S's magnitude and vertical location, respectively. Based on the monthly averaged density profile data, the Richardson number and wavelet analysis, the NIOs are considered to be capable of inducing predominant shear instability around the pycnocline. However, the NIOs are not strong enough to influence the lower YSCWM. In addition, in autumn, each fortnightly spring tide corresponds with a bottom temperature increase of nearly 2°C, indicating that tidal currents are the leading hydrodynamic driving force to decline the YSCWM.

  16. Balancing modern Power System with large scale of wind power

    OpenAIRE

    Basit, Abdul; Altin, Müfit; Hansen, Anca Daniela; Sørensen, Poul Ejnar

    2014-01-01

    Power system operators must ensure robust, secure and reliable power system operation even with a large scale integration of wind power. Electricity generated from the intermittent wind in large propor-tion may impact on the control of power system balance and thus deviations in the power system frequency in small or islanded power systems or tie line power flows in interconnected power systems. Therefore, the large scale integration of wind power into the power system strongly concerns the s...

  17. EXPERIMENTAL INVESTIGATION OF EFFECTS OF INNER-TANK SLOSHING ON HYDRODYNAMICS OF AN FLNG SYSTEM

    Institute of Scientific and Technical Information of China (English)

    ZHAO Wen-hua; YANG Jian-min; HU Zhi-qiang; XIAO Long-fei

    2012-01-01

    The present research focuses on experimentally clarifying the effect of inner-tank sloshing on the hydrodynamics of an Floating Liquefied Natural Gas (FLNG) system.Through the comparisons of the results obtained from the model tests carried out with the vessel model ballasted with liquid and solid cargo separately,the effects of the inner-tank sloshing on the hydrodynamics of an FLNG system are highlighted and presented.Statistical languages of the maximum,minimum,mean values and the standard deviations and power density spectra calculated with the help of the algorithm of Fast Fourier Transformation (FFT) are provided.It is concluded that the effects of the inner-tank sloshing on the responses of the FLNG system are sensitive to wave excitation frequencies,and that the effects of the inner-tank sloshing play an important role,particularly in the roll motion of the FLNG hull.The outcome of the proposed technique would offer constructive feedback,which can lead to more practical applications and can serve as a reference for the verification of the potential numerical simulations by other researchers.

  18. Dissolution of a Tetrachloroethene (PCE) pool in an Anaerobic Sand Tank Aquifer System: Bioenhancement, Ecology, and Hydrodynamics

    Science.gov (United States)

    Klemm, Sara; Becker, Jennifer; Seagren, Eric

    2017-04-01

    Dehalorespiring bacteria that reductively dechlorinate and grow on chlorinated ethenes in the aqueous phase can also achieve treatment of dense nonaqueous phase liquid (DNAPL) contaminants in the subsurface via bioenhanced dissolution, i.e., enhanced mass transfer from the DNAPL to the aqueous phase. Theoretical and experimental analyses predict that a number of interrelated physicochemical processes (e.g., advection and dispersion) and biological factors (e.g., biokinetics and competition) may influence the degree of bioenhancement. This research focused on understanding the interrelated roles that hydrodynamics and ecological interactions among dehalorespiring populations play in determining the distribution of dehalorespiring populations and the impact on bioenhanced dissolution and detoxification. The hypotheses driving this research are that: (1) ecological interactions between different dehalorespiring strains can significantly impact the dissolution rate bioenhancement and extent of dechlorination; and (2) hydrodynamics near the DNAPL pool will affect the outcome of ecological interactions and the potential for bioenhancement and detoxification. These hypotheses were evaluated via a multi-objective modeling and experimental framework focused on quantifying the impact of microbial interactions and hydrodynamics on the dissolution rate bioenhancement and plume detoxification using a model co-culture of Desulfuromonas michiganensis BB1 and Dehalococcoides mccartyi 195. The experiments were performed in a saturated intermediate-scale flow cell (1.2 m), with flow parallel to a tetrachloroethene (PCE) pool. Bioenhancement of PCE dissolution by the two dehalorespirers was evaluated using a steady-state mass balance, and initially resulted in a two- to three-fold increase in the dissolution rate, with cis-dichloroethene (cDCE) as the primary dechlorination product. Quantitative analysis of microbial population distribution and abundance using a 16S rRNA gene-based q

  19. Local Balancing System from the Business Model Canvas Perspective

    Directory of Open Access Journals (Sweden)

    Matusiak Bożena Ewa

    2016-01-01

    Full Text Available The paper presents an overall view of the business model (BM for the e-balance system for: balancing energy production and consumption in energy efficient, smart neighbourhoods (the e-balance project, FP7-SMARTCITIES-2013 along with its functionalities, based upon the Osterwalder’s canvas methodology. Additionally, this is the second, after two years of work, more incisive evaluation of the BM from the user’s and demo site’s perspective (Bronsbergen, the Netherlands. The aim of this paper is to present results and assess the above mentioned BM in the face its commercialisation and applicability to Europe.

  20. BETWEEN BALANCED SCORECARD AND QUALITY MANAGEMENT SYSTEM

    Directory of Open Access Journals (Sweden)

    Jelena Jovanović

    2008-09-01

    Full Text Available The aim of this research is to analyze parallel implementation of BSC as a strategic management system and quality management system by the principals of ISO 9000 certification. We will analyze advantages and disadvantages of the models. Further more, the research will analyze cumulative advantages of the two systems implementation. The research will present possibilities for BSC implementation in QMS environment, underlining the processes. We will put the accent on improvement of firm's effectiveness by Strategic Management System (BSC and Quality Management System's implementation.

  1. Projection-free approximate balanced truncation of large unstable systems

    Science.gov (United States)

    Flinois, Thibault L. B.; Morgans, Aimee S.; Schmid, Peter J.

    2015-08-01

    In this article, we show that the projection-free, snapshot-based, balanced truncation method can be applied directly to unstable systems. We prove that even for unstable systems, the unmodified balanced proper orthogonal decomposition algorithm theoretically yields a converged transformation that balances the Gramians (including the unstable subspace). We then apply the method to a spatially developing unstable system and show that it results in reduced-order models of similar quality to the ones obtained with existing methods. Due to the unbounded growth of unstable modes, a practical restriction on the final impulse response simulation time appears, which can be adjusted depending on the desired order of the reduced-order model. Recommendations are given to further reduce the cost of the method if the system is large and to improve the performance of the method if it does not yield acceptable results in its unmodified form. Finally, the method is applied to the linearized flow around a cylinder at Re = 100 to show that it actually is able to accurately reproduce impulse responses for more realistic unstable large-scale systems in practice. The well-established approximate balanced truncation numerical framework therefore can be safely applied to unstable systems without any modifications. Additionally, balanced reduced-order models can readily be obtained even for large systems, where the computational cost of existing methods is prohibitive.

  2. Numerical simulation of the hydrodynamics within octagonal tanks in recirculating aquaculture systems

    Science.gov (United States)

    Liu, Yao; Liu, Baoliang; Lei, Jilin; Guan, Changtao; Huang, Bin

    2016-07-01

    A three-dimensional numerical model was established to simulate the hydrodynamics within an octagonal tank of a recirculating aquaculture system. The realizable k-ɛ turbulence model was applied to describe the flow, the discrete phase model (DPM) was applied to generate particle trajectories, and the governing equations are solved using the finite volume method. To validate this model, the numerical results were compared with data obtained from a full-scale physical model. The results show that: (1) the realizable k-ɛ model applied for turbulence modeling describes well the flow pattern in octagonal tanks, giving an average relative error of velocities between simulated and measured values of 18% from contour maps of velocity magnitudes; (2) the DPM was applied to obtain particle trajectories and to simulate the rate of particle removal from the tank. The average relative error of the removal rates between simulated and measured values was 11%. The DPM can be used to assess the self-cleaning capability of an octagonal tank; (3) a comprehensive account of the hydrodynamics within an octagonal tank can be assessed from simulations. The velocity distribution was uniform with an average velocity of 15 cm/s; the velocity reached 0.8 m/s near the inlet pipe, which can result in energy losses and cause wall abrasion; the velocity in tank corners was more than 15 cm/s, which suggests good water mixing, and there was no particle sedimentation. The percentage of particle removal for octagonal tanks was 90% with the exception of a little accumulation of ≤ 5 mm particle in the area between the inlet pipe and the wall. This study demonstrated a consistent numerical model of the hydrodynamics within octagonal tanks that can be further used in their design and optimization as well as promote the wide use of computational fluid dynamics in aquaculture engineering.

  3. Numerical characterization of the hydrodynamics and thermal behavior of air flow in flexible air distribution system

    Science.gov (United States)

    Gharehdaghi, Samad; Moujaes, Samir

    2013-10-01

    Flexible duct air distribution systems are used in a large percentage of residential and small commercial buildings in the United States . Very few empirical or predictive data are available though to help provide the HVAC design engineer with reliable information . Moreover, because of the ducts flexibility, the shapes of these ducts offer a different set of operating fluid flow and thermal conditions from traditional smooth metal ducts. Hence, both the flow field and heat transfer through this kind of ducts are much more complex and merit to be analyzed from a numerical predictive approach. The aim of this research paper is to compute some of the hydrodynamic and heat transfer characteristics of the air flow inside these ducts over a range of Re numbers commonly used in the flow conditions of these air distribution systems. The information resulting from this CFD simulation, where a κ-ɛ turbulent model is used to predict the flow conditions, provide pressure drop and average convective heat transfer coefficients that exist in these ducts and was compared to previously found data. Circulation zones in the depressions of these ducts are found to exist which are suspected of influencing the pressured drop and heat transfer coefficients as compared to smooth ducts. The results show that fully developed conditions exist much earlier with regard to the inlet for both hydrodynamic and thermal entrance regions than what would be expected in smooth ducts under the same turbulent conditions.

  4. Stochastic Hall-Magneto-hydrodynamics System in Three and Two and a Half Dimensions

    Science.gov (United States)

    Yamazaki, Kazuo

    2017-01-01

    We introduce the stochastic Hall-magneto-hydrodynamics (Hall-MHD) system in three and two and a half dimensions with infinite-dimensional multiplicative noise, white in time, and prove the global existence of a martingale solution via a stochastic Galerkin approximation and applications of Prokhorov's, Skorokhod's and martingale representation theorems, as well as the pressure term through de Rham's theorem adapted to processes. The Hall term represents mathematically a very singular nonlinear term, unprecedented in the previous work. The results extend many others on the deterministic Hall-MHD and stochastic MHD systems and Navier-Stokes equations. In contrast to the stochastic MHD system, the path-wise uniqueness in the two and a half dimensional case is an open problem.

  5. Architectural Review of Load Balancing Single System Image

    Directory of Open Access Journals (Sweden)

    B. S. Ahmed

    2008-01-01

    Full Text Available Problem statement: With the growing popularity of clustering application combined with apparent usability, the single system image is in the limelight and actively studied as an alternative solution for computational intensive applications as well as the platform for next evolutionary grid computing era. Approach: Existing researches in this field concentrated on various features of Single System Images like file system and memory management. However, an important design consideration for this environment is load allocation and balancing that is usually handled by an automatic process migration daemon. Literature shows that the design concepts and factors that affect the load balancing feature in an SSI system are not clear. Result: This study will review some of the most popular architecture and algorithms used in load balancing single system image. Various implementations from the past to present will be presented while focusing on the factors that affect the performance of such system. Conclusion: The study showed that although there are some successful open source systems, the wide range of implemented systems investigated that research activity should concentrate on the systems that have already been proposed and proved effectiveness to achieve a high quality load balancing system.

  6. FACTORS OF STEADY AND BALANCED DEVELOPMENT OF REGIONAL ECONOMIC SYSTEMS

    Directory of Open Access Journals (Sweden)

    Polidi A. A.

    2016-03-01

    Full Text Available The article proves the need of identification and classification of the most relevant factors of the sustainable balanced development of the regional economic system (RES. Substantial filling of the category "sustainable balanced development" which is accepted within the real research is designated. On the basis of the analysis of the classifications of factors of the sustainable balanced development of economy of the region presented in scientific literature their discrepancy modern is established to conditions of globalization of the economy causing increase of a role of foreign economic activity of territorial subjects of the Russian Federation in ensuring their long-term competitiveness. Proceeding from the last, within the classification of factors of the sustainable balanced development of RES offered by authors the following their groups are allocated: global, national, regional. For each of the designated groups we substantiated the set of relevant factors

  7. The Study On Load Balancing Strategies In Distributed Computing System

    Directory of Open Access Journals (Sweden)

    Md. Firoj Ali

    2012-05-01

    Full Text Available A number of load balancing algorithms were developed in order to improve the execution of a distributed application in any kind of distributed architecture. Load balancing involves assigning tasks to each processor and minimizing the execution time of the program. In practice, it would be possible even to execute the applications on any machine of worldwide distributed systems. However, the ‘distributed system’ becomes popular and attractive with the introduction of the web. This results in a significant performance improvement for the users. This paper describes the necessary, newly developed, principal concepts for several load balancing techniques in a distributed computing environment. This paper also includes various types of load balancing strategies, their merits, demerits and comparison depending on certain parameters.

  8. Hydrodynamics of a hybrid circulating fluidized bed reactor with a partitioned loop seal system

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Dal-Hee; Moon, Jong-Ho; Jin, Gyoung Tae; Shun, Dowon [Korea Institute of Energy Research, Daejeon (Korea, Republic of); Yun, Minyoung; Park, Chan Seung; Norbeck, Joseph M. [University of California, Riverside (United States)

    2015-07-15

    A circulating fluidized bed (CFB) with a hybrid design has been developed and optimized for steam hydrogasification. The hybrid CFB is composed of a bubbling fluidized bed (BFB) type combustor and a fast fluidized bed (FB) type gasifier. Char is burnt in the combustor and the generated heat is supplied to the gasifier along with the bed materials. Two different types of fluidized beds are connected to each other with a newly developed partitioned loop seal to avoid direct contact between two separate gas streams flowing in each fluidized bed. Gas mixing tests were carried out with Air and Argon in a cold model hybrid CFB to test the loop seal efficiency. Increase in solid inventory in the loop seal can improve the gas separation efficiency. It can be realized at higher gas velocity in fast bed and with higher solid inventory in the loop seal system. In addition, bed hydrodynamics was investigated with varying gas flow conditions and particle sizes in order to obtain a full understanding of changes of solid holdup in the FB. The solid holdup in the FB increased with increasing gas velocity in the BFB. Conversely, increase in gas velocity in the FB contributed to reducing the solid holdup in the FB. It was observed that changing the particle size of bed material does not have a big impact on hydrodynamic parameters.

  9. Hydrodynamic performance of distributed pump-jet propulsion system for un- derwater vehicle

    Institute of Scientific and Technical Information of China (English)

    LÜ Xiao-jun; ZHOU Qi-dou; FANG Bin

    2014-01-01

    A type of distributed pump-jet propulsion system (DPJP) is developed with two or four specially designed pump-jet pods located around the axisymmetric underwater vehicle body symmetrically. The flow field is numerically simulated by solving the RANS equations with the finite volume method. The computational method is validated by comparing the calculated hull resistances of the SUBOFF AFF-3 model and the open water performance of a ducted propeller with experimental data. The hydrodynamic performances of the DPJP with different axial or radial positions and numbers of pump-jet pods are obtained to analyze the interactions between the hull and the pump-jet pods. It is shown in the calculated results that the decrease of the distance between the pods and the hull leads to an increase both in the efficiency of the pods and the thrust deduction factor due to the effect of the stern wake. And, a negative thrust deduction factor can be obtained by locating the DPJP at the parallel middle body near the aftbody of the vehicle to improve the hydrodynamic performance of the DPJP. Besides, the increase of the number of pods will cause a remarkable decrease of the total propulsive efficiency of the DPJP with the pods mounted on the stern planes, while a small decline of the total propulsive efficiency of the DPJP is observed with the pods mounted on the parallel middle body.

  10. DESIGNING COMPANY PERFORMANCE MEASUREMENT SYSTEM USING BALANCE SCORECARD APPROACH

    Directory of Open Access Journals (Sweden)

    Cecep Mukti Soleh

    2015-05-01

    Full Text Available This research aimed to design how to measure company performance by using balance scorecard approach in coal transportation services industry. Depth interview was used to obtain qualitative data determination of strategic objectives, key performance indicators, strategic initiatives, and in charge units for each balanced scorecard perspectives while the quantitative data were obtained from weighting through questionnaires and analyzed using paired comparison to get a perspective what mostly affected the performance of the company. To measure the achievement of corporate performance, each KPI used (1 the scoring system with the methods that higher is better, lower is better and precise is better; (2 traffic light system with the help of green, yellow, red for identification of target achievement. This research result shows that in the balance scorecard perspective, the most influences on the overall performance of the company include the customer's perspective (31%, financial perspective (29%, internal business processes (21%, learning, and growth 19%. Keywords: balance scorecard, paired comparison, coal transportation serviceABSTRAKPenelitian ini bertujuan untuk merancang pengukuran kinerja perusahaan dengan menggunakan pendekatan balance scorecard di industri jasa pengangkutan batu bara. Data kualitatif diperoleh melalui indepth interview digunakan untuk menentukan sasaran strategik, indikator kinerja utama, inisiatif strategi dan penanggungjawab setiap divisi setiap perspektif balance scorecard, sedangkan data kuantitatif digunakan untuk pembobotan melalui kuesioner dan dianalisis dengan menggunakan metode paired comparisson untuk mendapatkan perspektif yang paling berpengaruh terhadap kinerja perusahaan. Ukuran pencapaian kinerja perusahaan dari setiap KPI menggunakan; (1 scoring system dengan bantuan metode higher is better, lower is better dan precise is better;(2 traffic light system dengan menggunakan bantuan warna hijau, kuning, merah

  11. Singular Value Analysis and Balanced Realizations for Nonlinear Systems

    NARCIS (Netherlands)

    Fujimoto, Kenji; Scherpen, Jacquelien M.A.; Rommes, Joost; Schilders, Wilhelmus H.A.; Vorst, Henk A. van der

    2008-01-01

    For linear control systems minimal realization theory and the related model reduction methods play a crucial role in understanding and handling the system. These methods are well established and have proved to be very successful. In particular the method called balanced truncation gives a good

  12. Hydrodynamic limit for particle systems with degenerate rates without exclusive constraints

    CERN Document Server

    Sasada, Makiko

    2010-01-01

    We consider the hydrodynamic behavior of some conservative particle systems with degenerate jump rates without exclusive constraints. More precisely, we study the particle systems without restrictions on the total number of particles per site with nearest neighbor exchange rates which vanish for certain configurations. Due to the degeneracy of the rates, there exists blocked configurations which do not evolve under the dynamics and all of the hyperplanes of configurations with a fixed number particles can be decomposed into different irreducible sets. We show that, for initial profiles smooth enough and bounded away from zero, the macroscopic density profile evolves under the diffusive time scaling according to a nonlinear diffusion equation (which we call the modified porous medium equation). The proof is based on the Relative Entropy method but it cannot be straightforwardly applied because of the degeneracy.

  13. FERTILIZER RECOMMENDATION SYSTEM FOR MELON BASED ON NUTRITIONAL BALANCE

    Directory of Open Access Journals (Sweden)

    José Aridiano Lima de Deus

    2015-04-01

    Full Text Available Melon is one of the most demanding cucurbits regarding fertilization, requiring knowledge of soils, crop nutritional requirements, time of application, and nutrient use efficiency for proper fertilization. Developing support systems for decision-making for fertilization that considers these variables in nutrient requirement and supply is necessary. The objective of this study was parameterization of a fertilizer recommendation system for melon (Ferticalc-melon based on nutritional balance. To estimate fertilizer recommendation, the system considers the requirement subsystem (REQ, which includes the demand for nutrients by the plant, and the supply subsystem (SUP, which corresponds to the supply of nutrients through the soil and irrigation water. After determining the REQtotal and SUPtotal, the system calculates the nutrient balances for N, P, K, Ca, Mg, and S, recommending fertilizer application if the balance is negative (SUP < REQ, but not if the balance is positive or zero (SUP ≥ REQ. Simulations were made for different melon types (Yellow, Cantaloupe, Galia and Piel-de-sapo, with expected yield of 45 t ha-1. The system estimated that Galia type was the least demanding in P, while Piel-de-sapo was the most demanding. Cantaloupe was the least demanding for N and Ca, while the Yellow type required less K, Mg, and S. As compared to other fertilizer recommendation methods adopted in Brazil, the Ferticalc system was more dynamic and flexible. Although the system has shown satisfactory results, it needs to be evaluated under field conditions to improve its recommendations.

  14. Assessment of Energy Removal Impacts on Physical Systems: Hydrodynamic Model Domain Expansion and Refinement, and Online Dissemination of Model Results

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhaoqing; Khangaonkar, Tarang; Wang, Taiping

    2010-08-01

    In this report we describe the 1) the expansion of the PNNL hydrodynamic model domain to include the continental shelf along the coasts of Washington, Oregon, and Vancouver Island; and 2) the approach and progress in developing the online/Internet disseminations of model results and outreach efforts in support of the Puget Sound Operational Forecast System (PS-OPF). Submittal of this report completes the work on Task 2.1.2, Effects of Physical Systems, Subtask 2.1.2.1, Hydrodynamics, for fiscal year 2010 of the Environmental Effects of Marine and Hydrokinetic Energy project.

  15. Novel load balancing DHT scheme for the heterogeneous system

    Institute of Scientific and Technical Information of China (English)

    Li Yujun; Lu Xianliang; Hou Mengshu

    2008-01-01

    The capacities of the nodes in the peer-to-peer system are strongly heterogeneous,hence one can benefit from distributing the load.based on the capacity of the nodes.At first a model is discussed to evaluate the load balancing of the heterogeneous system,and then a novel load balancing scheme is proposed based on the concept of logical servers and the randomized binary tree,and theoretical guarantees are given.Finally,the feasibility of the scheme using extensive simulations is proven.

  16. Hydrodynamic system behaviour: its analysis and implications for flood risk management

    Directory of Open Access Journals (Sweden)

    de Bruijn Karin M.

    2016-01-01

    Full Text Available Knowledge on the different components of flood risk has much improved over the last decades, but research which fully takes into account not only the interactions between those components but also between different areas in a catchment or delta is still rare. Integrated analyses based on a complete system’s approach at sufficiently large scale will improve our understanding of how flood risk systems with flood protection infrastructure in place behave under extreme conditions, it may help to develop sensible long-term strategies, and allows us to better prepare for flood events of all magnitudes. To illustrate the relevance of a hydrodynamic system’s approach for flood risk management we analyse the effect of defence breaches on flood risks elsewhere along the lower Rhine River and discuss the use of this knowledge for flood risk management.

  17. A hydrodynamic linear instability in a system of confined colloidal rollers

    Science.gov (United States)

    Donev, Aleksandar; Delmotte, Blaise; Driscoll, Michelle; Chaikin, Paul

    2016-11-01

    In a typical flow instability, the fastest growing wavelength is selected by two or more competing stresses. In this talk I will discuss a very different kind of instability, controlled by a single geometric parameter. We study theoretically a new instability which has been observed experimentally and numerically: the fingering of a front of suspended microrollers near a floor. Our continuum model shows that this instability is linear and that the size scale selection arises only from hydrodynamic interactions between the particles and the wall, independently of the driving forces and viscosity. We believe that this instability mechanism is quite generic and selects the instability length scale in a number of suspension/colloid systems near a wall. This work was supported primarily by the Materials Research Science and Engineering Center (MRSEC) program of the National Science Foundation under Award Number DMR-1420073.

  18. Non-local features of a hydrodynamic pilot-wave system

    Science.gov (United States)

    Nachbin, Andre; Couchman, Miles; Bush, John

    2016-11-01

    A droplet walking on the surface of a vibrating fluid bath constitutes a pilot-wave system of the form envisaged for quantum dynamics by Louis de Broglie: a particle moves in resonance with its guiding wave field. We here present an examination of pilot-wave hydrodynamics in a confined domain. Specifically, we present a one-dimensional water wave model that describes droplets walking in single and multiple cavities. The cavities are separated by a submerged barrier, and so allow for the study of tunneling. They also highlight the non-local dynamical features arising due to the spatially-extended wave field. Results from computational simulations are complemented by laboratory experiments.

  19. Hydrodynamic processes, velocity structure and stratification in natural turbidity currents: Results inferred from field data in the Var Turbidite System

    Science.gov (United States)

    Migeon, Sébastien; Mulder, Thierry; Savoye, Bruno; Sage, Françoise

    2012-03-01

    The Var Turbidite System (NW Mediterranean Sea) is fed during the present-day highstand sea level by large earthquake-induced ignitive turbidity currents, low-density turbidity currents resulting from retrogressive failures triggered on the upper continental slope, and hyperpycnal flows related to the Var River floods. Using a large dataset including bathymetric data, side-scan sonar images, seismic-reflection profiles, cores and photographs of the seafloor, this paper attempts to better constrain the hydrodynamic behaviour of debris flows and turbidity currents along the Upper and Middle Valley of the Var Turbidite System. The drastic change of the seafloor morphology between the Upper and the Middle Valley suggests that gravity flows undergo rapid transformation from cohesive to fully turbulent behaviour. This transformation is related to a hydraulic jump caused by an abrupt decrease in slope angle at the transition between the Upper and the Middle Valley and is associated with en masse deposition and elevation of the seafloor. Strong seafloor erosion prevails in the Middle Valley, suggesting that, for a low and constant slope angle, turbulent flows must regain a balance between concentration and flow thickness rapidly after they experience hydraulic jump. The internal stratification and vertical grain-size distribution within turbulent flows are inferred from the distribution of fine- to coarse-grained turbidites found in cores located along the crest of the Var Sedimentary Ridge with a decreasing elevation above the floor of the Middle Valley. The theoretical vertical velocity profile deduced from the vertical grain-size distribution exhibits a general trend and an inflection of the gradient curve different from those of the velocity profiles classically obtained using numerical modelling.

  20. Pressure Drop Hysteresis of Hydrodynamic States in Packed Tower for Foaming Systems

    Directory of Open Access Journals (Sweden)

    Vijay Sodhi

    2011-11-01

    Full Text Available An experimental investigation was carried out to determine the effects of gas and liquid flow velocities and surface tension on the two-phase phase pressure drop a in a downflow trickle bed reactor. Water and non- Newtonian foaming solutions were employed as liquid phase. More than 240 experimental points for the trickle flow (GCF and foaming pulsing flow (PF/FPF regime were obtained for present study. Hydrodynamic characteristics involving two-phase pressure drop significantly influenced by gas and liquid flow rates. For 15 and 30 ppm air-aqueous surfactant solutions, two-phase pressure drop increases with higher liquid and gas flow velocities in trickle flow and foaming/pulsing flow regimes. With decrease in surface tension i.e. for 45 and 60 ppm air-aqueous surfactant systems, two-phase pressure drop increases very sharply during change in regime transition at significantly low liquid and gas velocities. Copyright © 2011 BCREC UNDIP. All rights reserved.(Received: 14th March 2011, Revised: 29th June 2011; Accepted: 4th July 2011[How to Cite: V. Sodhi, and R. Gupta. (2011. Pressure Drop Hysteresis of Hydrodynamic States in Packed Tower for Foaming Systems. Bulletin of Chemical Reaction Engineering & Catalysis, 6(2: 115-122. doi:10.9767/bcrec.6.2.828.115-122][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.6.2.828.115-122 || or local: http://ejournal.undip.ac.id/index.php/bcrec/article/view/828 ] | View in 

  1. Simulation model of load balancing in distributed computing systems

    Science.gov (United States)

    Botygin, I. A.; Popov, V. N.; Frolov, S. G.

    2017-02-01

    The availability of high-performance computing, high speed data transfer over the network and widespread of software for the design and pre-production in mechanical engineering have led to the fact that at the present time the large industrial enterprises and small engineering companies implement complex computer systems for efficient solutions of production and management tasks. Such computer systems are generally built on the basis of distributed heterogeneous computer systems. The analytical problems solved by such systems are the key models of research, but the system-wide problems of efficient distribution (balancing) of the computational load and accommodation input, intermediate and output databases are no less important. The main tasks of this balancing system are load and condition monitoring of compute nodes, and the selection of a node for transition of the user’s request in accordance with a predetermined algorithm. The load balancing is one of the most used methods of increasing productivity of distributed computing systems through the optimal allocation of tasks between the computer system nodes. Therefore, the development of methods and algorithms for computing optimal scheduling in a distributed system, dynamically changing its infrastructure, is an important task.

  2. Increasing cropping system diversity balances productivity, profitability and environmental health

    Science.gov (United States)

    Balancing productivity, profitability, and environmental health is a key challenge for agricultural sustainability. Most crop production systems in the United States are characterized by low species and management diversity, high use of fossil energy and agrichemicals, and can have large negative im...

  3. Balance laws and centro velocity in dissipative systems

    NARCIS (Netherlands)

    Groesen, van E.; Mainardi, F.

    1990-01-01

    Starting with a density that is conserved for a dynamical system when dissipation is ignored, a local conservation law is derived for which the total flux (integrated over the spatial domain) is unique. When dissipation is incorporated, the conservation law becomes a balance law. The contribution du

  4. Balance laws and centro velocity in dissipative systems

    NARCIS (Netherlands)

    van Groesen, Embrecht W.C.; Mainardi, F.

    1990-01-01

    Starting with a density that is conserved for a dynamical system when dissipation is ignored, a local conservation law is derived for which the total flux (integrated over the spatial domain) is unique. When dissipation is incorporated, the conservation law becomes a balance law. The contribution

  5. A strategy for load balancing in distributed storage systems

    CERN Document Server

    CERN. Geneva

    2012-01-01

    Distributed storage systems are critical to the operation of the WLCG. These systems are not limited to fulfilling the long term storage requirements. They also serve data for computational analysis and other computational jobs. Distributed storage systems provide the ability to aggregate the storage and IO capacity of disks and tapes, but at the end of the day IO rate is still bound by the capabilities of the hardware, in particular the hard drives. Throughput of hard drives has increased dramatically over the decades, however for computational analysis IOPS is typically the limiting factor. To maximize return of investment, balancing IO load over available hardware is crucial. The task is made complicated by the common use of heterogeneous hardware and software environments that results from combining new and old hardware into a single storage system. This paper describes recent advances made in load balancing in the dCache distributed storage system. We describe a set of common requirements for load balan...

  6. Comparison of the balance accelerometer measure and balance error scoring system in adolescent concussions in sports.

    Science.gov (United States)

    Furman, Gabriel R; Lin, Chia-Cheng; Bellanca, Jennica L; Marchetti, Gregory F; Collins, Michael W; Whitney, Susan L

    2013-06-01

    High-technology methods demonstrate that balance problems may persist up to 30 days after a concussion, whereas with low-technology methods such as the Balance Error Scoring System (BESS), performance becomes normal after only 3 days based on previously published studies in collegiate and high school athletes. To compare the National Institutes of Health's Balance Accelerometer Measure (BAM) with the BESS regarding the ability to detect differences in postural sway between adolescents with sports concussions and age-matched controls. Cohort study (diagnosis); Level of evidence, 2. Forty-three patients with concussions and 27 control participants were tested with the standard BAM protocol, while sway was quantified using the normalized path length (mG/s) of pelvic accelerations in the anterior-posterior direction. The BESS was scored by experts using video recordings. The BAM was not able to discriminate between healthy and concussed adolescents, whereas the BESS, especially the tandem stance conditions, was good at discriminating between healthy and concussed adolescents. A total BESS score of 21 or more errors optimally identified patients in the acute concussion group versus healthy participants at 60% sensitivity and 82% specificity. The BAM is not as effective as the BESS in identifying abnormal postural control in adolescents with sports concussions. The BESS, a simple and economical method of assessing postural control, was effective in discriminating between young adults with acute concussions and young healthy people, suggesting that the test has value in the assessment of acute concussions.

  7. Evaluation of surface energy and radiation balance systems for FIFE

    Science.gov (United States)

    Fritschen, Leo J.; Qian, Ping

    1988-01-01

    The energy balance and radiation balance components were determined at six sites during the First International Satellite Land Surface Climatology Project Field Experiment (FIFE) conducted south of Manhattan, Kansas during the summer of 1987. The objectives were: to determine the effect of slope and aspect, throughout a growing season, on the magnitude of the surface energy balance fluxes as determined by the Energy Balance Method (EBM); to investigate the calculation of the soil heat flux density at the surface as calculated from the heat capacity and the thermal conductivity equations; and to evaluate the performance of the Surface Energy and Radiation Balance System (SERBS). A total of 17 variables were monitored at each site. They included net, solar (up and down), total hemispherical (up and down), and diffuse radiation, soil temperature and heat flux density, air and wet bulb temperature gradients, wind speed and direction, and precipitation. A preliminary analysis of the data, for the season, indicate that variables including net radiation, air temperature, vapor pressure, and wind speed were quite similar at the sites even though the sites were as much as 16 km apart and represented four cardinal slopes and the top of a ridge.

  8. Procedure for Balancing an Air Distribution System with Decentralised Fans

    DEFF Research Database (Denmark)

    Gunner, Amalie; Hultmark, Göran; Vorre, Anders

    2015-01-01

    of the fans. In conventional air distribution systems the fan provides the necessary pressure to overcome the resistance in the branch with the highest pressure resistance. This gives an unnecessary overpressure in the remaining branches that does not provide any useful purpose. In order to decrease the fan......This paper presents results from an on-going project concerning new design procedures for mechanical ventilation systems with low energy use. Conventional constant air volume (CAV) systems are usually balanced using flat plate dampers. The purpose of using balancing dampers is to intentionally...... pressure requirements the fan was dimensioned for the branch with the least pressure resistance. The decentralised fans then provided sufficient pressure to overcome the exact resistance in the corresponding branch. The results show that by using decentralised fans in duct systems instead of dampers...

  9. An Efficient Diffusion Load Balancing Algorithm in Distributed System

    Directory of Open Access Journals (Sweden)

    Rafiqul Z. Khan

    2014-07-01

    Full Text Available In distributed computing system some nodes are very fast and some are slow and during the computation many fast nodes become idle or under loaded while the slow nodes become over loaded due to the uneven distribution of load in the system. In distributed system, the most common important factor is the information collection about loads on different nodes. The success of load balancing algorithm depends on how quickly the information about the load in the system is collected by a node willing to transfer or accept load. In this paper we have shown that the number of communication overheads depends on the number of overloaded nodes present in the domain of an under loaded nodes and vice-versa. We have also shown that communication overhead for load balancing is always fairly less than KN but in worst case our algorithm’s complexity becomes equal to KN.

  10. Hydrodynamics of sediment threshold

    Science.gov (United States)

    Ali, Sk Zeeshan; Dey, Subhasish

    2016-07-01

    A novel hydrodynamic model for the threshold of cohesionless sediment particle motion under a steady unidirectional streamflow is presented. The hydrodynamic forces (drag and lift) acting on a solitary sediment particle resting over a closely packed bed formed by the identical sediment particles are the primary motivating forces. The drag force comprises of the form drag and form induced drag. The lift force includes the Saffman lift, Magnus lift, centrifugal lift, and turbulent lift. The points of action of the force system are appropriately obtained, for the first time, from the basics of micro-mechanics. The sediment threshold is envisioned as the rolling mode, which is the plausible mode to initiate a particle motion on the bed. The moment balance of the force system on the solitary particle about the pivoting point of rolling yields the governing equation. The conditions of sediment threshold under the hydraulically smooth, transitional, and rough flow regimes are examined. The effects of velocity fluctuations are addressed by applying the statistical theory of turbulence. This study shows that for a hindrance coefficient of 0.3, the threshold curve (threshold Shields parameter versus shear Reynolds number) has an excellent agreement with the experimental data of uniform sediments. However, most of the experimental data are bounded by the upper and lower limiting threshold curves, corresponding to the hindrance coefficients of 0.2 and 0.4, respectively. The threshold curve of this study is compared with those of previous researchers. The present model also agrees satisfactorily with the experimental data of nonuniform sediments.

  11. Stochastic simulation of reaction-diffusion systems: A fluctuating-hydrodynamics approach

    Science.gov (United States)

    Kim, Changho; Nonaka, Andy; Bell, John B.; Garcia, Alejandro L.; Donev, Aleksandar

    2017-03-01

    We develop numerical methods for stochastic reaction-diffusion systems based on approaches used for fluctuating hydrodynamics (FHD). For hydrodynamic systems, the FHD formulation is formally described by stochastic partial differential equations (SPDEs). In the reaction-diffusion systems we consider, our model becomes similar to the reaction-diffusion master equation (RDME) description when our SPDEs are spatially discretized and reactions are modeled as a source term having Poisson fluctuations. However, unlike the RDME, which becomes prohibitively expensive for an increasing number of molecules, our FHD-based description naturally extends from the regime where fluctuations are strong, i.e., each mesoscopic cell has few (reactive) molecules, to regimes with moderate or weak fluctuations, and ultimately to the deterministic limit. By treating diffusion implicitly, we avoid the severe restriction on time step size that limits all methods based on explicit treatments of diffusion and construct numerical methods that are more efficient than RDME methods, without compromising accuracy. Guided by an analysis of the accuracy of the distribution of steady-state fluctuations for the linearized reaction-diffusion model, we construct several two-stage (predictor-corrector) schemes, where diffusion is treated using a stochastic Crank-Nicolson method, and reactions are handled by the stochastic simulation algorithm of Gillespie or a weakly second-order tau leaping method. We find that an implicit midpoint tau leaping scheme attains second-order weak accuracy in the linearized setting and gives an accurate and stable structure factor for a time step size of an order of magnitude larger than the hopping time scale of diffusing molecules. We study the numerical accuracy of our methods for the Schlögl reaction-diffusion model both in and out of thermodynamic equilibrium. We demonstrate and quantify the importance of thermodynamic fluctuations to the formation of a two

  12. Capillary Action may Cool Systems and Precisely balance Chemical Reactions

    Science.gov (United States)

    Kriske, Richard

    2011-10-01

    It is well known that it takes no work for Water to rise in a Capillary tube against the force of Gravity. There is a precise balance in this system that resembles Robert Millikan's ``Oil Drop'' experiment, where mass was balanced against the electrostatic force. If at the top of the capillary tube there is evaporation, one can see that the system is cooled as another water molecule has room to move up the column. Furthermore, if the evaporation process can be controlled one photon at a time, a precise balance is created between a photon, and the height/mass of the column. If other molecules are place in the column, they can be moved up and down the column, in a chromatograph way, in a fairly precise manner, by controlling evaporation and molecular weight. If in addition to all of this, the interface of the solution against the walls of the column have Fermi levels, it can be seen as a very precise Electrochemical Device. In the situation of nanotubes, as opposed to trees and plants, these properties can be used to create measure environmental properties and to Balance Chemical Reactions. Forests, and Plants may cool themselves and their environment using this process, and using this process coupled with more energetic photons through photosynthesis.

  13. A novel load balancing method for hierarchical federation simulation system

    Science.gov (United States)

    Bin, Xiao; Xiao, Tian-yuan

    2013-07-01

    In contrast with single HLA federation framework, hierarchical federation framework can improve the performance of large-scale simulation system in a certain degree by distributing load on several RTI. However, in hierarchical federation framework, RTI is still the center of message exchange of federation, and it is still the bottleneck of performance of federation, the data explosion in a large-scale HLA federation may cause overload on RTI, It may suffer HLA federation performance reduction or even fatal error. Towards this problem, this paper proposes a load balancing method for hierarchical federation simulation system based on queuing theory, which is comprised of three main module: queue length predicting, load controlling policy, and controller. The method promotes the usage of resources of federate nodes, and improves the performance of HLA simulation system with balancing load on RTIG and federates. Finally, the experiment results are presented to demonstrate the efficient control of the method.

  14. Balance impairment in people with multiple sclerosis: preliminary evidence for the Balance Evaluation Systems Test.

    Science.gov (United States)

    Jacobs, Jesse V; Kasser, Susan L

    2012-07-01

    This study examined the validity of the Balance Evaluation Systems Test (BESTest) to identify balance impairments in people with multiple sclerosis (MS) by evaluating differences in BESTest performance between people with and without MS. We also assessed the BESTest's validity by correlation with objective measures of postural performance as well as with disease severity and fall status. Thirteen subjects with MS (Expanded Disability Status Scale; EDSS: 0-4.5) and 13 matched subjects without MS were evaluated on the BESTest, asked about fall history, and assessed by force plates and motion capture as they performed laboratory tasks of step initiation, forward leaning to the limits of stability, and postural responses to rotations of the support surface. Compared to subjects without MS, subjects with MS exhibited lower total BESTest scores (mean (95%) score for subjects with MS=91 (83-99); subjects without MS=105 (104-107)) as well as section scores pertaining to mechanical constraints, limits of stability, anticipatory postural adjustments, and gait. BESTest scores significantly correlated with objective laboratory measures of step velocity during step initiation (Pearson r(2)=0.48, P<0.01) as well as center-of-pressure displacements during both the leaning (Pearson r(2)=0.55, P<0.005) and postural-response tasks (Pearson r(2)=0.76, P<0.0001). BESTest total scores were 92% accurate to identify fallers and non-fallers, and BESTest scores significantly correlated with EDSS scores (Spearman's rho=0.85, P<0.0005). Thus, the BESTest provides a valid clinical assessment of balance impairments in people with MS.

  15. Projection-free approximate balanced truncation of large unstable systems

    CERN Document Server

    Flinois, Thibault L B; Schmid, Peter J

    2015-01-01

    In this article, we show that the projection-free, snapshot-based, balanced truncation method can be applied directly to unstable systems. We prove that even for unstable systems, the unmodified balanced proper orthogonal decomposition algorithm theoretically yields a converged transformation that balances the Gramians (including the unstable subspace). We then apply the method to a spatially developing unstable system and show that it results in reduced-order models of similar quality to the ones obtained with existing methods. Due to the unbounded growth of unstable modes, a practical restriction on the final impulse response simulation time appears, which can be adjusted depending on the desired order of the reduced-order model. Recommendations are given to further reduce the cost of the method if the system is large and to improve the performance of the method if it does not yield acceptable results in its unmodified form. Finally, the method is applied to the linearized flow around a cylinder at Re = 100...

  16. Web-based home rehabilitation gaming system for balance training

    Directory of Open Access Journals (Sweden)

    Oleh Kachmar

    2014-06-01

    Full Text Available Currently, most systems for virtual rehabilitation and motor training require quite complex and expensive hardware and can be used only in clinical settings. Now, a low-cost rehabilitation game training system has been developed for patients with movement disorders; it is suitable for home use under the distant supervision of a therapist. It consists of a patient-side application installed on a home computer and the virtual rehabilitation Game Server in the Internet. System can work with different input gaming devices connected through USB or Bluetooth, such as a Nintendo Wii balance board, a Nintendo Wii remote, a MS Kinect sensor, and custom made rehabilitation gaming devices based on a joystick. The same games can be used with all training devices. Assessment of the Home Rehabilitation Gaming System for balance training was performed on six patients with Cerebral Palsy, who went through daily training sessions for two weeks. Preliminary results showed balance improvement in patients with Cerebral Palsy after they had completed home training courses. Further studies are needed to establish medical requirements and evidence length.

  17. Formation of polygonal fault systems as a result of hydrodynamical instabilities in clay-rich deposits.

    Science.gov (United States)

    Lopez, Teodolina; Antoine, Raphael; Rabinowicz, Michel; Baratoux, David; Darrozes, José; Kurita, Kei; D'Uston, Lionel

    2015-04-01

    Fine grained deposits as chalks and clays are characterised by the development of polygonal fault systems [1]. For the clay-rich deposits, two different environments are associated with their formation. First, on continents, dewatering leads to the development of polygonal desiccation cracks which have a centimetric to metric size [2]. Polygonal faults are also observed in sub-marine sedimentary deposits and here, can reach hectometric to kilometric size [3]. Since the giant polygons develop on basins with no clear evidences of tectonic stresses, the fracturing is attributed to stresses due to horizontal density variations generated during the basin subsidence. Several models have been proposed to explain the formation of the giant polygons and the two main hypotheses are the syneresis (spontaneous horizontal contraction) proposed by [4] and the low coefficient of friction of clay proposed by [5]. However, new understandings in the clay rheology and in the hydrodynamical instabilities, controlling the development of compaction in unconsolidated and consolidated clay deposits, permit us to propose an alternative hypothesis. We consider that the development of giant polygons results from the superposition of hydrodynamical instabilities leading to the formation of (i) mm-size agglomerates of clay particles while the deposit is unconsolidated [6], followed after by the consolidation of this layer, then (ii) hectometric to kilometric compaction spheres develop [7] and (iii) finally ends with the occurrence of hydrothermal and plastic convections. We show that the crucial conditions for the development of hectometric to kilometric size polygonal fault systems are: 1) the high permeability of the clay-rich deposit composed of mm-size agglomerates and 2) the dramatic increase of the strength of the clay as the deposit consolidates. [1] Dewhurst et al., (1999), Mar. Petr. Geol., 16 (8), 793-810. [2] Weinberger (1999), J. Struct. Geol., 21, 379-386. [3] Andresen and Huuse

  18. CSR BALANCED SCORECARD SYSTEMS AND BUSINESS PERFORMANCES: SMEs CASE STUDY

    Directory of Open Access Journals (Sweden)

    Edward Sek Khin Wong

    2016-01-01

    Full Text Available This paper aims to examine the performance measurement using the CSR Balanced Scorecard system in SMEs firms in Malaysia. It investigates the relationships of the four perspectives of CSR Balanced Scorecard system toward performance measurement. The purpose of this paper is to in- vestigate whether or not the improvement of the non-financial CSR measures will lead to the im- provement of performance measures. To test these relationships, data were collected using the four perspectives approach introduced by Utting (2007. The finding indicates that the organizational business performance can be greatly increased by putting greater emphasis to CSR measures. The results also reveal that the increases of firms customer’s satisfaction is caused by the increase imple- mentation of CSR measurement. At the end of the article, the implications of this study for SME industries and some suggestions are discussed for future studies.

  19. Offshore Wind Balance-of-System Cost Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Maness, Michael; Stehly, Tyler; Maples, Ben; Mone, Christopher

    2015-09-29

    Offshore wind balance-of-system (BOS) costs contribute up to 70% of installed capital costs. Thus, it is imperative to understand the impact of these costs on project economics as well as potential cost trends for new offshore wind technology developments. As a result, the National Renewable Energy Laboratory (NREL) developed and recently updated a BOS techno-economic model using project cost estimates created from wind energy industry sources.

  20. Theoretical analysis of balanced truncation for linear switched systems

    DEFF Research Database (Denmark)

    Petreczky, Mihaly; Wisniewski, Rafal; Leth, John-Josef

    2012-01-01

    In this paper we present theoretical analysis of model reduction of linear switched systems based on balanced truncation, presented in [1,2]. More precisely, (1) we provide a bound on the estimation error using L2 gain, (2) we provide a system theoretic interpretation of grammians...... for showing this independence is realization theory of linear switched systems. [1] H. R. Shaker and R. Wisniewski, "Generalized gramian framework for model/controller order reduction of switched systems", International Journal of Systems Science, Vol. 42, Issue 8, 2011, 1277-1291. [2] H. R. Shaker and R....... Wisniewski, "Switched Systems Reduction Framework Based on Convex Combination of Generalized Gramians", Journal of Control Science and Engineering, 2009....

  1. Optimal design of a lagrangian observing system for hydrodynamic surveys in coastal areas

    Science.gov (United States)

    Cucco, Andrea; Quattrocchi, Giovanni; Antognarelli, Fabio; Satta, Andrea; Maicu, Francesco; Ferrarin, Christian; Umgiesser, Georg

    2014-05-01

    The optimization of ocean observing systems is a pressing need for scientific research. In particular, the improvement of ocean short-term observing networks is achievable by reducing the cost-benefit ratio of the field campaigns and by increasing the quality of measurements. Numerical modeling is a powerful tool for determining the appropriateness of a specific observing system and for optimizing the sampling design. This is particularly true when observations are carried out in coastal areas and lagoons where, the use satellites is prohibitive due to the water shallowness. For such areas, numerical models are the most efficient tool both to provide a preliminary assess of the local physical environment and to make short -term predictions above its change. In this context, a test case experiment was carried out within an enclosed shallow water areas, the Cabras Lagoon (Sardinia, Italy). The aim of the experiment was to explore the optimal design for a field survey based on the use of coastal lagrangian buoys. A three-dimensional hydrodynamic model based on the finite element method (SHYFEM3D, Umgiesser et al., 2004) was implemented to simulate the lagoon water circulation. The model domain extent to the whole Cabras lagoon and to the whole Oristano Gulf, including the surrounding coastal area. Lateral open boundary conditions were provided by the operational ocean model system WMED and only wind forcing, provided by SKIRON atmospheric model (Kallos et al., 1997), was considered as surface boundary conditions. The model was applied to provide a number of ad hoc scenarios and to explore the efficiency of the short-term hydrodynamic survey. A first field campaign was carried out to investigate the lagrangian circulation inside the lagoon under the main wind forcing condition (Mistral wind from North-West). The trajectories followed by the lagrangian buoys and the estimated lagrangian velocities were used to calibrate the model parameters and to validate the

  2. Energy Balance Sheet of a Semi Operational Thermic System

    Directory of Open Access Journals (Sweden)

    Honus Stanislav

    2014-09-01

    Full Text Available The article is focused onthe energetical balance of a technical system for the conversion of crushed tyres by pyrolysis. Process temperatures were set in the range from 500 to 650°C. Mass input of the material was 30 kg per hour. The aim of the article is to answer the following questions as regards the individual products: Under which process conditions can the highest quality of the individual products related to energy be reached? How does the thermal efficiency of the system change in reaction to various conditions of the process?

  3. ON THE AXIAL TRANSIENT RESPONSE ANALYSIS OF THE SECTOR-SHAPED HYDRODYNAMIC THRUST BEARING-ROTOR SYSTEM IN A TURBOEXPANDER

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A model for the non-linear axial vibrations of the hydrodynamic thrust bearing-rotor system in a turboexpander is described.The axial transient process of the system is investigated.The timedependent form ofthe Reynolds equation is solved by a finite difference method with successive overrelaxation scheme to obtain the hydrodynamic forces of the sector-shaped thrust bearing (SSTB).Using these forces,the equation of motion is solved by the fourth-order Runge-Kutta method and the Adams method to predict the transient behaviour of the thrust bearing-rotor system (TBRS).Also,the linearized stiffness and damping coefficients of the oil film hydrodynamic SSTB are calculated.The analyses of the axial transient response of the system under both linear and non-linear conditions are performed.The non-linearity of oil film forces can significantly contribute to the axial transient response.Conclusions obtained can be applied for evaluation of the reliability of the TBRS.

  4. Modeling and analysis of linear hyperbolic systems of balance laws

    CERN Document Server

    Bartecki, Krzysztof

    2016-01-01

    This monograph focuses on the mathematical modeling of distributed parameter systems in which mass/energy transport or wave propagation phenomena occur and which are described by partial differential equations of hyperbolic type. The case of linear (or linearized) 2 x 2 hyperbolic systems of balance laws is considered, i.e., systems described by two coupled linear partial differential equations with two variables representing physical quantities, depending on both time and one-dimensional spatial variable. Based on practical examples of a double-pipe heat exchanger and a transportation pipeline, two typical configurations of boundary input signals are analyzed: collocated, wherein both signals affect the system at the same spatial point, and anti-collocated, in which the input signals are applied to the two different end points of the system. The results of this book emerge from the practical experience of the author gained during his studies conducted in the experimental installation of a heat exchange cente...

  5. Balance impairment and systemic inflammation in chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Tudorache E

    2015-09-01

    Full Text Available Emanuela Tudorache,1 Cristian Oancea,1 Claudiu Avram,2 Ovidiu Fira-Mladinescu,1 Lucian Petrescu,3 Bogdan Timar4 1Department of Pulmonology, University of Medicine and Pharmacy “Victor Babes”, 2Physical Education and Sport Faculty, West University of Timisoara, 3Department of Cardiology, University of Medicine and Pharmacy “Victor Babes”, 4Department of Biostatistics and Medical Informatics, University of Medicine and Pharmacy “Victor Babes”, Timisoara, Romania Background/purpose: Chronic obstructive pulmonary disease (COPD, especially in severe forms, is commonly associated with systemic inflammation and balance impairment. The aim of our study was to evaluate the impact on equilibrium of stable and exacerbation (acute exacerbation of COPD [AECOPD] phases of COPD and to investigate if there is a connection between lower extremity muscle weakness and systemic inflammation.Methods: We enrolled 41 patients with COPD (22 stable and 19 in AECOPD and 20 healthy subjects (control group, having no significant differences regarding the anthropometric data. We analyzed the differences in balance tests scores: Falls Efficacy Scale-International (FES-I questionnaire, Berg Balance Scale (BBS, Timed Up and Go (TUG test, Single Leg Stance (SLS, 6-minute walking distance (6MWD, isometric knee extension (IKE between these groups, and also the correlation between these scores and inflammatory biomarkers.Results: The presence and severity of COPD was associated with significantly decreased score in IKE (P<0.001, 6MWD (P<0.001, SLS (P<0.001, and BBS (P<0.001, at the same time noting a significant increase in median TUG score across the studied groups (P<0.001. The AECOPD group vs stable group presented a significant increase in high-sensitive C-reactive protein (hs-CRP levels (10.60 vs 4.01; P=0.003 and decrease in PaO2 (70.1 vs 59.1; P<0.001. We observed that both IKE scores were significantly and positive correlated with all the respiratory volumes

  6. Testing Postural Stability: Are the Star Excursion Balance Test and Biodex Balance System Limits of Stability Tests Consistent?

    Science.gov (United States)

    Glave, A Page; Didier, Jennifer J; Weatherwax, Jacqueline; Browning, Sarah J; Fiaud, Vanessa

    2016-01-01

    There are a variety of options to test postural stability; however many physical tests lack validity information. Two tests of postural stability - the Star Excursion Balance Test (SEBT) and Biodex Balance System Limits of Stability Test (LOS) - were examined to determine if similar components of balance were measured. Healthy adults (n=31) completed the LOS (levels 6 and 12) and SEBT (both legs). SEBT directions were offset by 180° to approximate LOS direction. Correlations and partial correlations controlling for height were analyzed. Correlations were significant for SEBT 45° and LOS back-left (6: r=-0.41; 12: r=-0.42; pbalance. Research is needed to determine and define what specific components of balance are being assessed. Care must be taken when choosing balance tests to best match the test to the purpose of testing (fall risk, athletic performance, etc.).

  7. Developing a System for Efficient Analysis of Lumbosacral Sagittal Balance

    Directory of Open Access Journals (Sweden)

    D. M. Zhuk

    2015-01-01

    Full Text Available Lumbosacral sagittal balance is the neutral vertical alignment in the sagittal plane to provide decreasing stress loading on muscular-ligamentous structures. The achieving sagittal balance is a basis to provide successful surgical treatment and minimize further complications. As of today, there is no standard quantitative evaluation method of sagittal lumbo-sacral balance, which allows conducting its effective analysis and planning surgical treatment taking into consideration the preservation of normal biomechanics of lumbosacral spine. The goal of the study is to develop a diagnostic system for individual correction of lumbo-sacral sagittal balance by the author’s method with automatic counting and optimized matching of data values based on a specified number of terms using medical visualization data. This study has been conducted with RMAPE’s Department of Traumatology and Orthopedic Surgery. To solve the problem, a random searching algorithm has been exploited. The stop condition of the algorithm was to achieve the objective function value in adjusted interval, initial points of which are the calculated (angular values. The interaction of the angular values, used in the proposed method has been investigated, and their proportional change has been proved. Moreover, the mathematical dependence among geometrical and anatomical parameters of lumbosacral spine has been determined. Based on conducted study, a number of algorithms enabling the automation of the individual determination of optimal lumbosacral balance’s parameters at preoperative planning stage for patients with vertebral column diseases have been created. This allows us to raise physician’s efficiency, minimize mid- and long-term risk of postoperative complications, and avoid reoperations, and prognosticate long-term complications already performed surgery.

  8. Creating a balanced scorecard for a hospital system.

    Science.gov (United States)

    Pink, G H; McKillop, I; Schraa, E G; Preyra, C; Montgomery, C; Baker, G R

    2001-01-01

    In 1999, hospitals in Ontario, Canada, collaborated with a university-based research team to develop a report on the relative performance of individual hospitals in Canada's most populated province. The researchers used the balanced-scorecard framework advocated by Kaplan and Norton. Indicators of performance were developed in four areas: clinical utilization and outcomes, patient satisfaction, system integration and change, and financial performance and condition. The process of selecting, calculating, and validating meaningful indicators of financial performance and condition is outlined. Lessons learned along the way are provided. These lessons may prove valuable to other finance researchers and practitioners who are engaged in performance measurement endeavors.

  9. Arctic melt ponds and energy balance in the climate system

    Science.gov (United States)

    Sudakov, Ivan

    2017-02-01

    Elements of Earth's cryosphere, such as the summer Arctic sea ice pack, are melting at precipitous rates that have far outpaced the projections of large scale climate models. Understanding key processes, such as the evolution of melt ponds that form atop Arctic sea ice and control its optical properties, is crucial to improving climate projections. These types of critical phenomena in the cryosphere are of increasing interest as the climate system warms, and are crucial for predicting its stability. In this paper, we consider how geometrical properties of melt ponds can influence ice-albedo feedback and how it can influence the equilibria in the energy balance of the planet.

  10. Automated dual capillary electrophoresis system with hydrodynamic injection for the concurrent determination of cations and anions

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Thi Thanh Thuy; Mai, Thanh Duc [University of Basel, Department of Chemistry, Spitalstrasse 51, Basel 4056 (Switzerland); Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Nguyen Trai Street 334, Hanoi (Viet Nam); Nguyen, Thanh Dam [Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Nguyen Trai Street 334, Hanoi (Viet Nam); Sáiz, Jorge [Department of Analytical Chemistry, Physical Chemistry and Chemical Engineering – University of Alcalá, Ctra. Madrid-Barcelona km 33.6, Alcalá de Henares, Madrid 28871 (Spain); Pham, Hung Viet, E-mail: phamhungviet@hus.edu.vn [Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Nguyen Trai Street 334, Hanoi (Viet Nam); Hauser, Peter C., E-mail: Peter.Hauser@unibas.ch [University of Basel, Department of Chemistry, Spitalstrasse 51, Basel 4056 (Switzerland)

    2014-09-02

    Highlights: • Concurrent determination of cations and anions was carried out by electrophoretic separation. • Optimized conditions for each class of analystes was possible by using separate capillaries. • Simultaneous hydrodynamic injection was carried out. • Pneumatic actuation was used for flushing and sample handling. • The denitrification of drinking water was successfully demonstrated. - Abstract: The capillary electrophoresis instrument developed for the concurrent determination of cations and anions features two separate capillaries and individual detectors to allow independent optimization for each group of ions. The capillaries are joined in a common injector block. The sample is drawn into the injector with a small membrane pump and automated simultaneous injection into both capillaries is achieved by pressurization of the fluid with compressed air. Flushing of the injector and of the capillaries with the background electrolyte is also carried out automatically by the same means. The buffer consisted of 12 mM histidine and 2 mM 18-crown-6 adjusted to pH 4 with acetic acid and was suitable for the contactless conductivity detection employed. The system was optimized for the determination of cationic NH{sub 4}{sup +} and anionic NO{sub 3}{sup −} and NO{sub 2}{sup −}, and linear calibration curves from about 20 μM up to about 1.5 mM were obtained for these ions. In a test run over 8 h, the reproducibility for the peak areas was within ±7%. For demonstration, the instrument was successfully applied to the concurrent monitoring of the concentrations of the three ions during the biological removal of ammonium from contaminated groundwater in a sequencing batch reactor, where NO{sub 3}{sup −} and NO{sub 2}{sup −} are formed as intermediate products.

  11. Magnetic suspension and balance system advanced study, phase 2

    Science.gov (United States)

    Boom, R. W.; Abdelsalam, M. K.; Eyssa, Y. M.; Mcintosh, G. E.

    1990-01-01

    The design improvements for the system encompass 14 or 18 external superconductive coils mounted on a 8 x 8 foot wind tunnel, a superconductive model core magnet on a holmium mandrel to fit an F-16 model, model wings of permanent magnet material Nd2Fe14B, and fiber glass epoxy structure. The Magnetic Suspension and Balance System (MSBS) advanced design is confirmed by the successful construction and test of a full size superconductive model core solenoid with holmium mandrel. The solenoid is 75 cm long and 12.6 cm in diameter and produces 6.1 tesla for a hold time of 47 minutes. An integrated coil system design of a new compact configuration without specific coils for roll or pitch shows promise of simplicity; magnet reductions of 30 percent compared to the most recent 1985 design are possible.

  12. Balance impairment and systemic inflammation in chronic obstructive pulmonary disease

    Science.gov (United States)

    Tudorache, Emanuela; Oancea, Cristian; Avram, Claudiu; Fira-Mladinescu, Ovidiu; Petrescu, Lucian; Timar, Bogdan

    2015-01-01

    Background/purpose Chronic obstructive pulmonary disease (COPD), especially in severe forms, is commonly associated with systemic inflammation and balance impairment. The aim of our study was to evaluate the impact on equilibrium of stable and exacerbation (acute exacerbation of COPD [AECOPD]) phases of COPD and to investigate if there is a connection between lower extremity muscle weakness and systemic inflammation. Methods We enrolled 41 patients with COPD (22 stable and 19 in AECOPD) and 20 healthy subjects (control group), having no significant differences regarding the anthropometric data. We analyzed the differences in balance tests scores: Falls Efficacy Scale-International (FES-I) questionnaire, Berg Balance Scale (BBS), Timed Up and Go (TUG) test, Single Leg Stance (SLS), 6-minute walking distance (6MWD), isometric knee extension (IKE) between these groups, and also the correlation between these scores and inflammatory biomarkers. Results The presence and severity of COPD was associated with significantly decreased score in IKE (P<0.001), 6MWD (P<0.001), SLS (P<0.001), and BBS (P<0.001), at the same time noting a significant increase in median TUG score across the studied groups (P<0.001). The AECOPD group vs stable group presented a significant increase in high-sensitive C-reactive protein (hs-CRP) levels (10.60 vs 4.01; P=0.003) and decrease in PaO2 (70.1 vs 59.1; P<0.001). We observed that both IKE scores were significantly and positive correlated with all the respiratory volumes. In both COPD groups, we observed that fibrinogen reversely and significantly correlated with the 6MWD, and FES-I questionnaire is correlated positively with TUG test. Hs-CRP correlated reversely with the walking test and SLS test, while correlating positively with TUG test and FES-I questionnaire. Conclusion According to this study, COPD in advanced and acute stages is associated with an increased history of falls, systemic inflammation, balance impairment, and lower extremity

  13. Relativistic hydrodynamics

    CERN Document Server

    Luciano, Rezzolla

    2013-01-01

    Relativistic hydrodynamics is a very successful theoretical framework to describe the dynamics of matter from scales as small as those of colliding elementary particles, up to the largest scales in the universe. This book provides an up-to-date, lively, and approachable introduction to the mathematical formalism, numerical techniques, and applications of relativistic hydrodynamics. The topic is typically covered either by very formal or by very phenomenological books, but is instead presented here in a form that will be appreciated both by students and researchers in the field. The topics covered in the book are the results of work carried out over the last 40 years, which can be found in rather technical research articles with dissimilar notations and styles. The book is not just a collection of scattered information, but a well-organized description of relativistic hydrodynamics, from the basic principles of statistical kinetic theory, down to the technical aspects of numerical methods devised for the solut...

  14. Modelling the hydrodynamic and morphosedimentary response of an beach-headland system (Algarve, Southern Portugal)

    Science.gov (United States)

    Horta, João; Oliveira, Sónia; Moura, Delminda

    2015-04-01

    Future behaviour of beaches within a headland-beach system is of fundamental interest on coastal evolution since they act as a buffer between the waves' attack and the cliffs backing them. The beaches at the cliffs' foot anchored between headlands are space-limited environments to morphosedimentary processes. Additionally, headlands and shore platforms are natural barriers to the alongshore drift. Several attempts to develop numerical expressions to characterize the stability of headland-beach systems have been made based mainly on linear parameters. However, in the sandy areas occur volumetric variations of greater magnitude that changes in the shoreline position in a tidal cycle. This work aims to quantify the balance between the incoming and the lost sediment in two embayed beaches in order to improve knowledge of the sedimentary dynamics of such environments and therefore the evolution of coastal landscapes. The study area is the Algarve coastal karstic landscapes, which raises challenging questions on morphosedimentary processes because it has dozens of stacks and cavities both in the surf zone and in the nearshore that interfere with the littoral current patterns. The field campaigns were performed during spring tide conditions in February and March, 2011. The nearshore wave climate and the current's velocity and direction were measured using respectively a non-vented Level TROLL 700 Pressure Transducer (PT) and an autonomously deployable electro-magnetic current meter (EMCM) Infinity-EM with a data logger. The offshore wave data used was acquired through the Portuguese Hydrographic Institute (IH) at the Faro buoy, located 50 km southeast from the study area. The topographic surveys were performed for a total area of about 1500 m2 using two Global Navigation Satellite System receptors (GPS Trimble R6 and GPS Trimble 5800) in real-time kinematic mode (RTK) with differential global positioning system (DGPS) providing centimetric accuracy. The altimetric values

  15. Balance perturbation system to improve balance compensatory responses during walking in old persons

    OpenAIRE

    2010-01-01

    Abstract Ageing commonly disrupts the balance control and compensatory postural responses that contribute to maintaining balance and preventing falls during perturbation of posture. This can lead to increased risk of falling in old adults (65 years old and over). Therefore, improving compensatory postural responses during walking is one of the goals in fall prevention programs. Training is often used to achieve this goal. Most fall prevention programs are usually directed towards improving vo...

  16. Application of CFD Modeling to Hydrodynamics of CycloBio Fluidized Sand Bed in Recirculating Aquaculture Systems

    Institute of Scientific and Technical Information of China (English)

    LIU Yao; SONG Xiefa; LIANG Zhenlin; PENG Lei

    2014-01-01

    To improve the efficiency of a CycloBio fluidized sand bed (CB FSB) in removal of dissolved wastes in recirculating aquaculture systems, the hydrodynamics of solid-liquid flow was investigated using computational fluid dynamics (CFD) modeling tools. The dynamic characteristics of silica sand within the CB FSB were determined using three-dimensional, unsteady-state simula-tions with the granular Eulerian multiphase approach and the RNG k-ε turbulence model, and the simulation results were validated using available lab-scale measurements. The bed expansion of CB FSB increased with the increase in water inflow rate in numerical simulations. Upon validation, the simulation involving 0.55 mm particles, the Gidaspow correlation for drag coefficient model and the Syamlal-O’Brien correlation for kinetic granular viscosity showed the closest match to the experimental results. The volume frac-tion of numerical simulations peaked as the wall was approached. The hydrodynamics of a pilot-scale CB FSB was simulated in or-der to predict the range of water flow to avoid the silica sand overflowing. The numerical simulations were in agreement with the experimental results qualitatively and quantitatively, and thus can be used to study the hydrodynamics of solid-liquid multiphase flow in CB FSB, which is of importance to the design, optimization, and amplification of CB FSBs.

  17. Theoretical hydrodynamics

    CERN Document Server

    Milne-Thomson, L M

    2011-01-01

    This classic exposition of the mathematical theory of fluid motion is applicable to both hydrodynamics and aerodynamics. Based on vector methods and notation with their natural consequence in two dimensions - the complex variable - it offers more than 600 exercises and nearly 400 diagrams. Prerequisites include a knowledge of elementary calculus. 1968 edition.

  18. Hydrodynamic bearings

    CERN Document Server

    Bonneau, Dominique; Souchet, Dominique

    2014-01-01

    This Series provides the necessary elements to the development and validation of numerical prediction models for hydrodynamic bearings. This book describes the rheological models and the equations of lubrication. It also presents the numerical approaches used to solve the above equations by finite differences, finite volumes and finite elements methods.

  19. Ship Hydrodynamics

    Science.gov (United States)

    Lafrance, Pierre

    1978-01-01

    Explores in a non-mathematical treatment some of the hydrodynamical phenomena and forces that affect the operation of ships, especially at high speeds. Discusses the major components of ship resistance such as the different types of drags and ways to reduce them and how to apply those principles for the hovercraft. (GA)

  20. Increasing cropping system diversity balances productivity, profitability and environmental health.

    Science.gov (United States)

    Davis, Adam S; Hill, Jason D; Chase, Craig A; Johanns, Ann M; Liebman, Matt

    2012-01-01

    Balancing productivity, profitability, and environmental health is a key challenge for agricultural sustainability. Most crop production systems in the United States are characterized by low species and management diversity, high use of fossil energy and agrichemicals, and large negative impacts on the environment. We hypothesized that cropping system diversification would promote ecosystem services that would supplement, and eventually displace, synthetic external inputs used to maintain crop productivity. To test this, we conducted a field study from 2003-2011 in Iowa that included three contrasting systems varying in length of crop sequence and inputs. We compared a conventionally managed 2-yr rotation (maize-soybean) that received fertilizers and herbicides at rates comparable to those used on nearby farms with two more diverse cropping systems: a 3-yr rotation (maize-soybean-small grain + red clover) and a 4-yr rotation (maize-soybean-small grain + alfalfa-alfalfa) managed with lower synthetic N fertilizer and herbicide inputs and periodic applications of cattle manure. Grain yields, mass of harvested products, and profit in the more diverse systems were similar to, or greater than, those in the conventional system, despite reductions of agrichemical inputs. Weeds were suppressed effectively in all systems, but freshwater toxicity of the more diverse systems was two orders of magnitude lower than in the conventional system. Results of our study indicate that more diverse cropping systems can use small amounts of synthetic agrichemical inputs as powerful tools with which to tune, rather than drive, agroecosystem performance, while meeting or exceeding the performance of less diverse systems.

  1. Increasing cropping system diversity balances productivity, profitability and environmental health.

    Directory of Open Access Journals (Sweden)

    Adam S Davis

    Full Text Available Balancing productivity, profitability, and environmental health is a key challenge for agricultural sustainability. Most crop production systems in the United States are characterized by low species and management diversity, high use of fossil energy and agrichemicals, and large negative impacts on the environment. We hypothesized that cropping system diversification would promote ecosystem services that would supplement, and eventually displace, synthetic external inputs used to maintain crop productivity. To test this, we conducted a field study from 2003-2011 in Iowa that included three contrasting systems varying in length of crop sequence and inputs. We compared a conventionally managed 2-yr rotation (maize-soybean that received fertilizers and herbicides at rates comparable to those used on nearby farms with two more diverse cropping systems: a 3-yr rotation (maize-soybean-small grain + red clover and a 4-yr rotation (maize-soybean-small grain + alfalfa-alfalfa managed with lower synthetic N fertilizer and herbicide inputs and periodic applications of cattle manure. Grain yields, mass of harvested products, and profit in the more diverse systems were similar to, or greater than, those in the conventional system, despite reductions of agrichemical inputs. Weeds were suppressed effectively in all systems, but freshwater toxicity of the more diverse systems was two orders of magnitude lower than in the conventional system. Results of our study indicate that more diverse cropping systems can use small amounts of synthetic agrichemical inputs as powerful tools with which to tune, rather than drive, agroecosystem performance, while meeting or exceeding the performance of less diverse systems.

  2. Study of the deconfinement phase transition in a finite volume with massive particles: Hydrodynamics of the system near the transition

    Energy Technology Data Exchange (ETDEWEB)

    Ghenam, L.; Djoudi, A. Ait El [Laboratoire de Physique des Particules et Physique Statistique, Ecole Normale Superieure - Kouba, B.P. 92, 16050, Vieux Kouba, Algiers (Algeria)

    2012-06-27

    We study the finite size and finite mass effects for the thermal deconfinement phase transition in Quantum Chromodynamics (QCD), using a simple model of coexistence of hadronic (H) gas and quark-gluon plasma (QGP) phases in a finite volume. We consider the equations of state of the two phases with the QGP containing two massless u and d quarks and massive s quarks, and a hadronic gas of massive pions, and we probe the system near the transition. For this, we examine the behavior of the most important hydrodynamical quantities describing the system, at a vanishing chemical potential ({mu}= 0), with temperature and energy density.

  3. Energy Balance for Random Vibrations of Piecewise-Conservative Systems

    Science.gov (United States)

    IOURTCHENKO, D. V.; DIMENTBERG, M. F.

    2001-12-01

    Vibrations of systems with instantaneous or stepwise energy losses, e.g., due to impacts with imperfect rebounds, dry friction forces(s) (in which case the losses may be treated as instantaneous ones by appropriate introduction of the response energy) and/or active feedback “bang-bang” control of the systems' response are considered. Response of such (non-linear) systems to a white-noise random excitation is considered for the case where there are no other response energy losses. Thus, a simple linear energy growth with time between “jumps” is observed. Explicit expressions for the expected response energy are derived by direct application of the stochastic differential equations calculus, which contains the expected time interval between two consecutive jumps. The latter may be predicted as a solution to the relevant first-passage problem. Perturbational analysis of the relevant PDE for this problem for a certain vibroimpact system demonstrated the possibility for using the solution to the corresponding free vibration problem as a zero order approximation. The method is applied to an s.d.o.f. system with a feedback inertia control, designed according to a certain previously introduced “generalized reversed swings law”. Extensive Monte-Carlo simulation results are presented for this system as well as for several previously analyzed ones: system with impacts; system with dry friction; system with stiffness control; pendulum with controlled length. The results are compared with those due to the asymptotic stochastic averaging approach. Both methods are shown to provide adequate accuracy far beyond the expected applicability range of the asymptotic approach (which requires both excitation intensity and losses to be small), with direct energy balance being generally superior.

  4. Altered balance in the autonomic nervous system in schizophrenic patients

    DEFF Research Database (Denmark)

    Nielsen, B M; Mehlsen, J; Behnke, K

    1988-01-01

    healthy subjects (32 +/- 7 years) served as controls. Immediate heart-rate responses to a single deep inspiration was used as a measure of parasympathetic function. Heart-rate response to standing was used as a measure of sympathetic function. Supine blood pressure, heart-rate and orthostatic changes...... in blood pressure did not differ between groups. Heart-rate response to standing was greater in both medicated and non-medicated schizophrenics compared to normal subjects (P less than 0.01). Heart-rate response to standing was greater in non-medicated compared to medicated schizophrenics (P less than 0.......05). Heart-rate response to inspiration was greater in non-medicated schizophrenics compared to normal subjects (P less than 0.05), whereas no difference was found between medicated and non-medicated schizophrenics. The results show that the balance in the autonomic nervous system is altered in schizophrenic...

  5. NUMERICAL SIMULATION OF THE EFFECTS OF WEIGHT SYSTEM ON THE HYDRODYNAMIC BEHAVIOR OF 3-D NET OF GRAVITY CAGE IN CURRENT

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this article, a model of 3-D net is set up by using lumped mass method. Model test results made by Lader and Enerhaug are cited to verify the numerical model. The aim of this paper is to investigate the effects of weight system on the hydrodynamic behavior of 3-D net of gravity cage in current. Using the 3-D net model, with different styles and masses of weight system, hydrodynamic behavior of gravity cage net in current is simulated. In this article, two styles of common weight system are used, which include: (1) sinker system , (2) bottom collar-sinker system. Under each style, three different masses of weight system are adopted. The numerical results indicate that the bottom collar-sinker system is practically feasible in improving the cage net volume deformation. Results of this study will give references for better knowledge of hydrodynamic behavior of gravity cage.

  6. Bacterial hydrodynamics

    CERN Document Server

    Lauga, Eric

    2015-01-01

    Bacteria predate plants and animals by billions of years. Today, they are the world's smallest cells yet they represent the bulk of the world's biomass, and the main reservoir of nutrients for higher organisms. Most bacteria can move on their own, and the majority of motile bacteria are able to swim in viscous fluids using slender helical appendages called flagella. Low-Reynolds-number hydrodynamics is at the heart of the ability of flagella to generate propulsion at the micron scale. In fact, fluid dynamic forces impact many aspects of bacteriology, ranging from the ability of cells to reorient and search their surroundings to their interactions within mechanically and chemically-complex environments. Using hydrodynamics as an organizing framework, we review the biomechanics of bacterial motility and look ahead to future challenges.

  7. Assessment of Tidal Energy Removal Impacts on Physical Systems: Development of MHK Module and Analysis of Effects on Hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhaoqing; Wang, Taiping

    2011-09-01

    In this report we describe (1) the development, test, and validation of the marine hydrokinetic energy scheme in a three-dimensional coastal ocean model (FVCOM); and (2) the sensitivity analysis of effects of marine hydrokinetic energy configurations on power extraction and volume flux in a coastal bay. Submittal of this report completes the work on Task 2.1.2, Effects of Physical Systems, Subtask 2.1.2.1, Hydrodynamics and Subtask 2.1.2.3, Screening Analysis, for fiscal year 2011 of the Environmental Effects of Marine and Hydrokinetic Energy project.

  8. Nanoflow hydrodynamics

    DEFF Research Database (Denmark)

    Hansen, Jesper Schmidt; Dyre, Jeppe C.; Daivis, Peter J.;

    2011-01-01

    We show by nonequilibrium molecular dynamics simulations that the Navier-Stokes equation does not correctly describe water flow in a nanoscale geometry. It is argued that this failure reflects the fact that the coupling between the intrinsic rotational and translational degrees of freedom becomes...... important for nanoflows. The coupling is correctly accounted for by the extended Navier-Stokes equations that include the intrinsic angular momentum as an independent hydrodynamic degree of freedom. © 2011 American Physical Society....

  9. Photovoltaic balance-of-system designs and costs at PVUSA

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, A.B.; Jennings, C.

    1995-05-01

    This report is one in a series of 1994-1995 PVUSA reports that document PVUSA lessons learned at demonstration sites in California and Texas. During the last 7 years (1988 to 1994), 16 PV systems ranging from 20 kW to 500 kW have been installed. Six 20-kW emerging module technology (EMT) arrays and three turnkey (i.e., vendor designed and integrated) utility-scale systems were procured and installed at PVUSA`s main test site in Davis, California. PVUSA host utilities have installed a total of seven EMT arrays and utility-scale systems in their service areas. Additional systems at Davis and host utility sites are planned. One of PVUSA`s key objectives is to evaluate the performance, reliability, and cost of PV balance-of-system (BOS). In the procurement stage PVUSA encouraged innovative design to improve upon present practice by reducing maintenance, improving reliability, or lowering manufacturing or construction costs. The project team worked closely with suppliers during the design stage not only to ensure designs met functional and safety specifications, but to provide suggestions for improvement. This report, intended for the photovoltaic (PV) industry and for utility project managers and engineers considering PV plant construction and ownership, documents PVUSA utility-scale system design and cost lessons learned. Complementary PVUSA topical reports document: construction and safety experience; five-year assessment of EMTs; validation of the Kerman 500-kW grid-support PV plant benefits; PVUSA instrumentation and data analysis techniques; procurement, acceptance, and rating practices for PV power plants; experience with power conditioning units and power quality.

  10. Hydrodynamical, hydrochemical and isotopic characterization of the Kourimat aquifer system (Essaouira basin, Morocco

    Directory of Open Access Journals (Sweden)

    Fernandes, P.

    2008-06-01

    Full Text Available The synclinal basin of Kourimat, subdivided in two sub-basins (Igounzar in the North, and Zeltene in the South, is situated in the oriental part of Essaouira basin shelters a carbonate aquifer system contained in the limestones and dolomitic limestones of the Cenomanian and the Turonian. These ground waters represent the only drinking water and irrigation resource for the region.The geological formations outcropping in the studied area, start with the clay and marly formations of the terminal Jurassic in the south of Zelten watershed, and end with the sandy and loamy Quaternary formations in coastal areas in the Low Qsob watershed. The Middle and Upper Cretaceous (marl, fractured limestone, and dolomites represent the rest of the stratigraphic series especially in the areas of the Igrounzar watershed (up to 85% of the outcrops and in Zelten (up to 50%.The field occupation is not very significant. It basically consists of three types: 1 cultures (essentially cereals where it is possible (on the marly soils of the Cretaceous, the Quaternary and the Eocene; 2 uncovered areas corresponding to the fissured and karstic limestone outcrops of the Cretaceous and the Jurassic formations, and 3 forests (coniferous trees in the downstream part of the catchments area (Plio-quaternary soils and mountainous reinforcements of the Western High Atlas. Like for other undeveloped areas of Morocco, the Meskala basin is also subjected to an intensive deforestation (wood for heating and cooking.The study undertaken on the Cenomano-turonian aquifer has allowed us to characterize it from the hydrodynamical, hydrogeological and hydrogeochemical point of view. The piezometric map of the two regrouped aquifer levels shows water flow senses from the SE to the NW. The hydraulic gradient varies from upstream to downstream, being weak n the central zone relative to the best hydrodynamic characteristics. The time evolution of the piezometry shows annual and seasonal

  11. Cross-diffusion-driven hydrodynamic instabilities in a double-layer system: General classification and nonlinear simulations

    Science.gov (United States)

    Budroni, M. A.

    2015-12-01

    Cross diffusion, whereby a flux of a given species entrains the diffusive transport of another species, can trigger buoyancy-driven hydrodynamic instabilities at the interface of initially stable stratifications. Starting from a simple three-component case, we introduce a theoretical framework to classify cross-diffusion-induced hydrodynamic phenomena in two-layer stratifications under the action of the gravitational field. A cross-diffusion-convection (CDC) model is derived by coupling the fickian diffusion formalism to Stokes equations. In order to isolate the effect of cross-diffusion in the convective destabilization of a double-layer system, we impose a starting concentration jump of one species in the bottom layer while the other one is homogeneously distributed over the spatial domain. This initial configuration avoids the concurrence of classic Rayleigh-Taylor or differential-diffusion convective instabilities, and it also allows us to activate selectively the cross-diffusion feedback by which the heterogeneously distributed species influences the diffusive transport of the other species. We identify two types of hydrodynamic modes [the negative cross-diffusion-driven convection (NCC) and the positive cross-diffusion-driven convection (PCC)], corresponding to the sign of this operational cross-diffusion term. By studying the space-time density profiles along the gravitational axis we obtain analytical conditions for the onset of convection in terms of two important parameters only: the operational cross-diffusivity and the buoyancy ratio, giving the relative contribution of the two species to the global density. The general classification of the NCC and PCC scenarios in such parameter space is supported by numerical simulations of the fully nonlinear CDC problem. The resulting convective patterns compare favorably with recent experimental results found in microemulsion systems.

  12. Hydrodynamic aspect of caves

    Directory of Open Access Journals (Sweden)

    Franci Gabrovsek

    2008-01-01

    Full Text Available From a hydrological point of view, active caves are a series of connected conduits which drain water through an aquifer. Water tends to choose the easiest way through the system but different geological and morphological barriers act as flow restrictions. The number and characteristics of restrictions depends on the particular speleogenetic environment, which is a function of geological, geomorphological, climatological and hydrological settings. Such a variety and heterogeneity of underground systems has presented a challenge for human understanding for many centuries. Access to many underground passages, theoretical knowledge and recent methods (modeling, water pressure-resistant dataloggers, precise sensors etc. give us the opportunity to get better insight into the hydrodynamic aspect of caves. In our work we tried to approach underground hydrodynamics from both theoretical and practical points of view. We present some theoretical background of open surface and pressurized flow in underground rivers and present results of some possible scenarios. Moreover, two case studies from the Ljubljanica river basin are presented in more detail: the cave system between Planinsko polje and Ljubljansko barje, and the cave system between Bloško polje and Cerkniško polje. The approach and methodology in each case is somewhat different, as the aims were different at the beginning of exploration. However, they both deal with temporal and spatial hydrodynamics of underground waters. In the case of Bloško polje-Cerkniško polje system we also explain the feedback loop between hydrodynamics and Holocene speleogenesis.

  13. Hydrodynamic instability in the open system of the iodate-arsenous acid reaction.

    Science.gov (United States)

    Pópity-Tóth, Éva; Pimienta, Véronique; Horváth, Dezső; Tóth, Ágota

    2013-10-28

    Hydrodynamic instability arising in horizontally propagating vertical chemical fronts leading to the formation of a single stable convection roll is investigated experimentally in the iodate-arsenous acid reaction for various stoichiometry. In the presence of a free surface, the tilted reaction front becomes more elongated due to the evaporation of the surface active iodine and the decrease in the surface tension during the reaction. The experimental conditions are then identified where Marangoni instability represents the driving force for the distortion of the reaction front at the surface.

  14. Depiction of interfacial morphology in impact welded Ti/Cu bimetallic systems using smoothed particle hydrodynamics

    Science.gov (United States)

    Nassiri, Ali; Vivek, Anupam; Abke, Tim; Liu, Bert; Lee, Taeseon; Daehn, Glenn

    2017-06-01

    Numerical simulations of high-velocity impact welding are extremely challenging due to the coupled physics and highly dynamic nature of the process. Thus, conventional mesh-based numerical methodologies are not able to accurately model the process owing to the excessive mesh distortion close to the interface of two welded materials. A simulation platform was developed using smoothed particle hydrodynamics, implemented in a parallel architecture on a supercomputer. Then, the numerical simulations were compared to experimental tests conducted by vaporizing foil actuator welding. The close correspondence of the experiment and modeling in terms of interface characteristics allows the prediction of local temperature and strain distributions, which are not easily measured.

  15. Hydrodynamic extensional stress during the bubble bursting process for bioreactor system design

    Science.gov (United States)

    Tran, Thanh Tinh; Lee, Eun Gyo; Lee, In Su; Woo, Nam Sub; Han, Sang Mok; Kim, Young Ju; Hwang, Wook Ryol

    2016-11-01

    Cell damage, one of critical issues in the bioreactor design for animal cell culture, is caused mainly from the bubble bursting at the free surface subjected to strong extensional flows. In this work, extensive computational studies are performed to investigate bubble bursting process in great details. Extensive numerical simulations are performed for a wide range of bubble diameters (from 0.5 to 6 mm) and the surface tension values (from 0.03 to 0.072 N/m), with which effects of the bubble size and surfactant (PF68) concentration on the hydrodynamic stress are investigated. For all the cases, the maximum extensional stress appears at the instance when receding films impact each other at the bottom of the bubble. A model equation based on numerical simulations is presented to predict the maximum extensional stress as a function of the bubble diameter and the surface tension. The bubble diameter has turned out to contribute significantly the maximum hydrodynamic extensional stress. In addition, the bubble collapsed time and the affected volume around a bubble subjected to the critical extensional stress are investigated. The extensional stress estimation is reported as a function of the bubble size and the surface tension. The influence of the bubble size on the maximum stress dominates and extensional stress reaches up to the order of 104 Pa for bubble size of 0.5 mm.

  16. Viscosity and dissipative hydrodynamics from effective field theory

    Science.gov (United States)

    Grozdanov, Sašo; Polonyi, Janos

    2015-05-01

    With the goal of deriving dissipative hydrodynamics from an action, we study classical actions for open systems, which follow from the generic structure of effective actions in the Schwinger-Keldysh closed-time-path (CTP) formalism with two time axes and a doubling of degrees of freedom. The central structural feature of such effective actions is the coupling between degrees of freedom on the two time axes. This reflects the fact that from an effective field theory point of view, dissipation is the loss of energy of the low-energy hydrodynamical degrees of freedom to the integrated-out, UV degrees of freedom of the environment. The dynamics of only the hydrodynamical modes may therefore not possess a conserved stress-energy tensor. After a general discussion of the CTP effective actions, we use the variational principle to derive the energy-momentum balance equation for a dissipative fluid from an effective Goldstone action of the long-range hydrodynamical modes. Despite the absence of conserved energy and momentum, we show that we can construct the first-order dissipative stress-energy tensor and derive the Navier-Stokes equations near hydrodynamical equilibrium. The shear viscosity is shown to vanish in the classical theory under consideration, while the bulk viscosity is determined by the form of the effective action. We also discuss the thermodynamics of the system and analyze the entropy production.

  17. Hydrodynamic model of cells for designing systems of urban groundwater drainage

    Science.gov (United States)

    Zimmermann, Eric; Riccardi, Gerardo

    2000-08-01

    An improved mathematical hydrodynamic quasi-two-dimensional model of cells, CELSUB3, is presented for simulating drainage systems that consist of pumping well fields or subsurface drains. The CELSUB3 model is composed of an assemblage of algorithms that have been developed and tested previously and that simulate saturated flow in porous media, closed conduit flow, and flow through pumping stations. A new type of link between aquifer cells and drainage conduits is proposed. This link is verified in simple problems with well known analytical solutions. The correlation between results from analytical and mathematical solutions was considered satisfactory in all cases. To simulate more complex situations, the new proposed version, CELSUB3, was applied in a project designed to control the water-table level within a sewer system in Chañar Ladeado Town, Santa Fe Province, Argentina. Alternative drainage designs, which were evaluated under conditions of dynamic recharge caused by rainfall in a critical year (wettest year for the period of record) and a typical year, are briefly described. After analyzing ten alternative designs, the best technical-economic solution is a subsurface drainage system of closed conduits with pumping stations and evacuation channels. Résumé. Un modèle hydrodynamique perfectionné de cellules en quasi 2D, CELSUB3, est présenté dans le but de simuler des systèmes de drainage qui consistent en des champs de puits de pompage ou de drains souterrains. Le modèle CELSUB3 est composé d'un assemblage d'algorithmes développés et testés précédemment et qui simulent des écoulements en milieu poreux saturé, en conduites et dans des stations de pompage. Un nouveau type de lien entre des cellules d'aquifères et des drains est proposé. Ce lien est vérifié dans des problèmes simples dont les solutions analytiques sont bien connues. La corrélation entre les résultats des solutions analytiques et des solutions mathématiques a été consid

  18. Market integration of wind power in electricity system balancing

    DEFF Research Database (Denmark)

    Sorknæs, Peter; Andersen, Anders N.; Tang, Jens

    2013-01-01

    In most countries markets for electricity are divided into wholesale markets on which electricity is traded before the operation hour, and real-time balancing markets to handle the deviations from the wholesale trading. So far, wind power has been sold only on the wholesale market and has been...... known to increase the need for balancing. This article analyses whether wind turbines in the future should participate in the balancing markets and thereby play a proactive role. The analysis is based on a real-life test of proactive participation of a wind farm in West Denmark. It is found...

  19. Potential benefits of magnetic suspension and balance systems

    Science.gov (United States)

    Lawing, Pierce L.; Dress, David A.; Kilgore, Robert A.

    1987-01-01

    The potential of Magnetic Suspension and Balance Systems (MSBS) to improve conventional wind tunnel testing techniques is discussed. Topics include: elimination of model geometry distortion and support interference to improve the measurement accuracy of aerodynamic coefficients; removal of testing restrictions due to supports; improved dynamic stability data; and stores separation testing. Substantial increases in wind tunnel productivity are anticipated due to the coalescence of these improvements. Specific improvements in testing methods for missiles, helicopters, fighter aircraft, twin fuselage transports and bombers, state separation, water tunnels, and automobiles are also forecast. In a more speculative vein, new wind tunnel test techniques are envisioned as a result of applying MSBS, including free-flight computer trajectories in the test section, pilot-in-the-loop and designer-in-the-loop testing, shipboard missile launch simulation, and optimization of hybrid hypersonic configurations. Also addressed are potential applications of MSBS to such diverse technologies as medical research and practice, industrial robotics, space weaponry, and ore processing in space.

  20. Solar, Install, Mount, Production, Labor, Equipment Balance of Systems

    Energy Technology Data Exchange (ETDEWEB)

    Gentry, Russell [Georgia Tech Applied Research Corporation, Atlanta, GA (United States); Al-Haddad, Tristan [Georgia Tech Applied Research Corporation, Atlanta, GA (United States); Valdes, Francisco [Georgia Tech Applied Research Corporation, Atlanta, GA (United States); Caravati, Kevin [Georgia Tech Applied Research Corporation, Atlanta, GA (United States); Goodman, Joseph [Georgia Tech Applied Research Corporation, Atlanta, GA (United States)

    2015-08-27

    The GTRI led project team in partnership with the DOE, universities, and numerous industry leaders, have advanced the mission of the DOE EERE, the Solar Energy Technologies Program, and the SunShot Initiative by accelerating the research, development, and demonstration of solar PV technologies that provide Extreme Balance of Systems Cost Reductions (BOS-X). The research produced 132 design concepts, resulting in 19 invention disclosures, five patent applications, four 90% pre-commercial designs, and three licensed technologies. Technology practice rights were obtained by an industry partner, and a new solar commercial start-up company was launched in Atlanta as a result of this project. Innovations in residential, commercial, and utility scale balance of systems technologies were realized through an unprecedented multi-disciplinary university/industry partnership with over 50 students and 24 faculty members that produced 18 technical publications, a PhD thesis, and two commercially deployed operating prototypes. The technical effectiveness and economic feasibility of the multidisciplinary systems based approach executed by the project team was realized through 1) a comprehensive evaluation of industry, regulatory, and public stakeholder requirements; 2) numerous industry/student/faculty engagements in design studios, technical conferences, and at solar PV installation sites; 3) time and motion studies with domain experts that provided technical data and costs for each phase and component of the solar PV installation processes; 4) extensive wind tunnel and systems engineering modeling; and 5) design, construction, and demonstration of the selected technologies in the field at high profile sites in Atlanta. The SIMPLE BOS project has benefitted the public in the following ways: • Workforce development: The launch of a start-up company to commercialize the DOE funded SIMPLE BoS designs has directly created 9 new jobs in the State of Georgia. As of November 2014, the

  1. A Half-Bridge Voltage Balancer with New Controller for Bipolar DC Distribution Systems

    Directory of Open Access Journals (Sweden)

    Byung-Moon Han

    2016-03-01

    Full Text Available This paper proposes a half-bridge voltage balancer with a new controller for bipolar DC distribution systems. The proposed control scheme consists of two cascaded Proportional Integral (PI controls rather than one PI control for balancing the pole voltage. In order to confirm the excellence of voltage balancing performance, a typical bipolar DC distribution system including a half-bridge voltage balancer with proposed controller was analyzed by computer simulations. Experiments with a scaled prototype were also carried out to confirm the simulation results. The half-bridge voltage balancer with proposed controller shows better performance than the half-bridge voltage balancer with one PI control for balancing the pole voltage.

  2. Introduction to Hydrodynamics

    CERN Document Server

    Jeon, Sangyong

    2015-01-01

    We give a pedagogical review of relativistic hydrodynamics relevant to relativistic heavy ion collisions. Topics discussed include linear response theory derivation of 2nd order viscous hydrodynamics including the Kubo formulas, kinetic theory derivation of 2nd order viscous hydrodynamics, anisotropic hydrodynamics and a brief review of numerical algorithms. Emphasis is given to the theory of hydrodynamics rather than phenomenology.

  3. Burst Mechanisms in Hydrodynamics

    CERN Document Server

    Knobloch, E

    1999-01-01

    Different mechanisms believed to be responsible for the generation of bursts in hydrodynamical systems are reviewed and a new mechanism capable of generating regular or irregular bursts of large dynamic range near threshold is described. The new mechanism is present in the interaction between oscillatory modes of odd and even parity in systems of large but finite aspect ratio, and provides an explanation for the bursting behavior observed in binary fluid convection. Additional applications of the new mechanism are proposed.

  4. Design of NAND FLASH File System Based on Loss of Balance Algorithm

    Directory of Open Access Journals (Sweden)

    Jinwu Ju

    2011-02-01

    Full Text Available NAND FLASH is a commonly large capacity memory, which used in embedded systems .It often used to store the operating system kernel and file system. NAND FLASH memory has a limited number of block erase feature. Built file system in NAND FLASH, loss of balance method should be adopted. A balanced system of block erase operation, can extend the life of NAND FLASH and improve overall system reliability. The paper analyzes the characteristics of NAND FLASH work .presents a loss of balance algorithm which used in NAND FLASH memory , and given out the implementation of the algorithm design method.

  5. THE OPTIMUM MODEL AND ITS DECISION SUPPORT SYSTEM OF COAL QUALITY BALANCE

    Institute of Scientific and Technical Information of China (English)

    孟祥瑞; 舒航

    1999-01-01

    The meaning and significance of coal quality balance are summarized in this paper. Practical steps concerning constructing the synthetic tech-economic model and its decision support system of coal quality balance using the optimization technology of inverse recurrence of established initializing parameters are also introduced. The principles and methods as being applied in the model system development and procedure construction are discussed accordingly.

  6. Submarine hydrodynamics

    CERN Document Server

    Renilson, Martin

    2015-01-01

    This book adopts a practical approach and presents recent research together with applications in real submarine design and operation. Topics covered include hydrostatics, manoeuvring, resistance and propulsion of submarines. The author briefly reviews basic concepts in ship hydrodynamics and goes on to show how they are applied to submarines, including a look at the use of physical model experiments. The issues associated with manoeuvring in both the horizontal and vertical planes are explained, and readers will discover suggested criteria for stability, along with rudder and hydroplane effectiveness. The book includes a section on appendage design which includes information on sail design, different arrangements of bow planes and alternative stern configurations. Other themes explored in this book include hydro-acoustic performance, the components of resistance and the effect of hull shape. Readers will value the author’s applied experience as well as the empirical expressions that are presented for use a...

  7. Market integration of wind power in electricity system balancing

    DEFF Research Database (Denmark)

    Sorknæs, Peter; Andersen, Anders N.; Tang, Jens

    2013-01-01

    In most countries markets for electricity are divided into wholesale markets on which electricity is traded before the operation hour, and real-time balancing markets to handle the deviations from the wholesale trading. So far, wind power has been sold only on the wholesale market and has been...... known to increase the need for balancing. This article analyses whether wind turbines in the future should participate in the balancing markets and thereby play a proactive role. The analysis is based on a real-life test of proactive participation of a wind farm in West Denmark. It is found...... that the wind farm is able to play a proactive role regarding downward regulation and thereby increase profits....

  8. Large scale water entry simulation with smoothed particle hydrodynamics on single- and multi-GPU systems

    Science.gov (United States)

    Ji, Zhe; Xu, Fei; Takahashi, Akiyuki; Sun, Yu

    2016-12-01

    In this paper, a Weakly Compressible Smoothed Particle Hydrodynamics (WCSPH) framework is presented utilizing the parallel architecture of single- and multi-GPU (Graphic Processing Unit) platforms. The program is developed for water entry simulations where an efficient potential based contact force is introduced to tackle the interaction between fluid and solid particles. The single-GPU SPH scheme is implemented with a series of optimization to achieve high performance. To go beyond the memory limitation of single GPU, the scheme is further extended to multi-GPU platform basing on an improved 3D domain decomposition and inter-node data communication strategy. A typical benchmark test of wedge entry is investigated in varied dimensions and scales to validate the accuracy and efficiency of the program. The results of 2D and 3D benchmark tests manifest great consistency with the experiment and better accuracy than other numerical models. The performance of the single-GPU code is assessed by comparing with serial and parallel CPU codes. The improvement of the domain decomposition strategy is verified, and a study on the scalability and efficiency of the multi-GPU code is carried out as well by simulating tests with varied scales in different amount of GPUs. Lastly, the single- and multi-GPU codes are further compared with existing state-of-the-art SPH parallel frameworks for a comprehensive assessment.

  9. Smoothed particle hydrodynamics: Applications to migration of radionuclides in confined aqueous systems.

    Science.gov (United States)

    Mayoral-Villa, Estela; Alvarado-Rodríguez, Carlos E; Klapp, Jaime; Gómez-Gesteira, Moncho; Sigalotti, Leonardo Di G

    2016-04-01

    A smoothed particle hydrodynamics (SPH) model is presented for simulating the decay chain transport of radionuclides in confined aqueous solutions. The SPH formulation is based on the open-source parallel code DualSPHysics extended to solve the advective-diffusion equation for the evolution of the concentration field coupled to the fluid-dynamic equations, including the effects of radioactive decay of the tracer contaminants. The performance of the method is demonstrated for environmental engineering problems dealing with the transport of contaminants in still and flowing water. The results from a series of benchmark test calculations are described in two- and three-space dimensions, where the advection, diffusion, and radioactive decay modes are tested separately and in combined form. The accuracy of the present SPH transport model is shown by direct comparison with the analytical solutions and results from other SPH approaches. For a given problem, convergence of the SPH solution is seen to increase with decreasing particle size and spacing.

  10. Smoothed particle hydrodynamics: Applications to migration of radionuclides in confined aqueous systems

    Science.gov (United States)

    Mayoral-Villa, Estela; Alvarado-Rodríguez, Carlos E.; Klapp, Jaime; Gómez-Gesteira, Moncho; Di G. Sigalotti, Leonardo

    2016-04-01

    A smoothed particle hydrodynamics (SPH) model is presented for simulating the decay chain transport of radionuclides in confined aqueous solutions. The SPH formulation is based on the open-source parallel code DualSPHysics extended to solve the advective-diffusion equation for the evolution of the concentration field coupled to the fluid-dynamic equations, including the effects of radioactive decay of the tracer contaminants. The performance of the method is demonstrated for environmental engineering problems dealing with the transport of contaminants in still and flowing water. The results from a series of benchmark test calculations are described in two- and three-space dimensions, where the advection, diffusion, and radioactive decay modes are tested separately and in combined form. The accuracy of the present SPH transport model is shown by direct comparison with the analytical solutions and results from other SPH approaches. For a given problem, convergence of the SPH solution is seen to increase with decreasing particle size and spacing.

  11. Implications of Upwells as Hydrodynamic Jets in a Pulse Jet Mixed System

    Energy Technology Data Exchange (ETDEWEB)

    Pease, Leonard F. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bamberger, Judith A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Minette, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-08-01

    This report evaluates the physics of the upwell flow in pulse jet mixed systems in the Hanford Tank Waste Treatment and Immobilization Plant (WTP). Although the initial downward flow and radial flow from pulse jet mixers (PJMs) has been analyzed in some detail, the upwells have received considerably less attention despite having significant implications for vessel mixing. Do the upwells behave like jets? How do the upwells scale? When will the central upwell breakthrough? What proportion of the vessel is blended by the upwells themselves? Indeed, how the physics of the central upwell is affected by multiple PJMs (e.g., six in the proposed mixing vessels), non-Newtonian rheology, and significant multicomponent solids loadings remain unexplored. The central upwell must satisfy several criteria to be considered a free jet. First, it must travel for several diameters in a nearly constant direction. Second, its velocity must decay with the inverse of elevation. Third, it should have an approximately Gaussian profile. Fourth, the influence of surface or body forces must be negligible. A combination of historical data in a 12.75 ft test vessel, newly analyzed data from the 8 ft test vessel, and conservation of momentum arguments derived specifically for PJM operating conditions demonstrate that the central upwell satisfies these criteria where vigorous breakthrough is achieved. An essential feature of scaling from one vessel to the next is the requirement that the underlying physics does not change adversely. One may have confidence in scaling if (1) correlations and formulas capture the relevant physics; (2) the underlying physics does not change from the conditions under which it was developed to the conditions of interest; (3) all factors relevant to scaling have been incorporated, including flow, material, and geometric considerations; and (4) the uncertainty in the relationships is sufficiently narrow to meet required specifications. Although the central upwell

  12. State dependent matrices and balanced energy functions for nonlinear systems

    NARCIS (Netherlands)

    Scherpen, Jacquelien M.A.; Gray, W. Steven

    2000-01-01

    The nonlinear extension of the balancing procedure requires the case of state dependent quadratic forms for the energy functions, i.e., the nonlinear extensions of the linear Gramians are state dependent matrices. These extensions have some interesting ambiguities that do not occur in the linear cas

  13. Modelling heavy metal and phosphorus balances for farming systems

    NARCIS (Netherlands)

    Keller, A.N.; Schulin, R.

    2003-01-01

    Accounting for agricultural activities such as P fertilization in regional models of heavy metal accumulation provides suitable sustainable management strategies to reduce nutrient surpluses and metal inputs in agricultural soils. Using the balance model PROTERRA-S, we assessed the phosphorus ( P),

  14. [Design of a mechanical system for the balanceable system of ambulance].

    Science.gov (United States)

    Zheng, Yi; Luo, Yibin; Zhang, Guangpeng; Zhang, Zhide; Chen, Chaomin

    2010-08-01

    This is the design of a mechanical systems for use in the balanceable system of ambulance, which can keep the medical service bed at the ambulance level, whatever the terrain is. A level detector will detect the level state of the bed and turn it to a signal. The central processing unit will use this signal to analyse and control the movement of the motor. By this design (which uses the rolling rail as a drive transmission and makes three supports of the bed go up and down), the bed will keep level. With the use of this design, the balanceable system of ambulance can counteract 35 degrees. The error is controlled within +/- 1 degree. And the response time is within 0.3 s. The method of registration can be effective for keeping the bed at the ambulance level, and for reducing the chance of making the patient get hurt on the way to hospital.

  15. The efficiency of a new hydrodynamic cavitation pilot system on Artemia salina cysts and natural population of copepods and bacteria under controlled mesocosm conditions.

    Science.gov (United States)

    Cvetković, Martina; Grego, Mateja; Turk, Valentina

    2016-04-15

    A study of the efficiency of hydrodynamic cavitation and separation was carried out to evaluate an innovative, environmentally safe and acceptable system for ballast water treatment for reducing the risk of introducing non-native species worldwide. Mesocosm experiments were performed to assess the morphological changes and viability of zooplankton (copepods), Artemia salina cysts, and the growth potential of marine bacteria after the hydrodynamic cavitation treatment with a different number of cycles. Our preliminary results confirmed the significant efficiency of the treatment since more than 98% of the copepods and A. salina cysts were damaged, in comparison with the initial population. The efficiency increased with the number of the hydrodynamic cavitation cycles, or in combination with a separation technique for cysts. There was also a significant decrease in bacterial abundance and growth rate, compared to the initial number and growth potential.

  16. Effect of load and speed on warship power rear drive system helical gear anti-scuffing properties in thermal elasto-hydrodynamic lubrication

    Directory of Open Access Journals (Sweden)

    Yongmei Wang

    2016-12-01

    Full Text Available The key parameters which caused the scoring failure of helical gears are operating load and speed. In this study, the simulations using geometric meshing theory were carried out to investigate the effect of load and speed of warship transmission helical gear system on thermal elasto-hydrodynamic lubrication. The numerical algorithm for the analysis of three-dimensional thermal elasto-hydrodynamic lubrication used in this work has advantage that the film pressure and distributions can be calculated from Reynolds equation for all mixed lubrication regions without any specific boundary condition for the edge of solid contact region. Oil film pressure, film thickness as well as film temperature under different load and speed conditions were obtained and compared. In addition, experimental tests were conducted to determine gear surface temperature under different load and speed conditions. This work provided a guidance to understand the load- and speed-dependent thermal elasto-hydrodynamic lubrication.

  17. Perturbation analysis of internal balancing for lightly damped mechanical systems with gyroscopic and circulatory forces

    Science.gov (United States)

    Blelloch, P. A.; Mingori, D. L.; Wei, J. D.

    1987-01-01

    Approximate expressions are developed for internally balanced singular values corresponding to the modes of mechanical systems with gyroscopic forces, light damping, and small circulatory forces. A brief overview is first given of the balanced realization model reduction method, including a discussion of recent work. The models considered are defined, and a perturbation analysis is used to show that the modal representation becomes asymptotically balanced as damping reduces to zero. The approximate balanced singular values are calculated, and a simple example of a flexible, dual-spin spacecraft is given as an illustration of the results.

  18. In Vitro Hydrodynamic Test and In Vitro Hemolysis Test for Development of Inexpensive Spiral Vortex Ventricular Assisting System Using IABP Console

    Institute of Scientific and Technical Information of China (English)

    Y. Ohnishi; K. Iwasaki; H. Mizuta; T. Sudo; S. Muto; T. Shima; T. Tanaka; K. Ito; M. Umezu

    2004-01-01

    The purpose of this research is to develop an inexpensive pulsatile blood pump system for short-term use, as a combination of the usage of IABP console and spiral vortex pump. In vitro hydrodynamic test and in vitro hemolysis test were conducted to check the practical performance.

  19. New Real-Time Market Facilitating Demand-Side Resources for System Balancing

    DEFF Research Database (Denmark)

    Feng, Donghan; Nyeng, Preben; Xie, Jun;

    2011-01-01

    of such loads can deliver a well-behaved, stable and predictable balancing support. Based on a comprehensive analysis of the current balancing markets, as well as the technical properties of traditional and potential balancing resources, this paper proposes a new real-time balancing market setup facilitating....... This research is potentially useful for designing future balancing markets and utilizing demand response for system services. Copyright (C) 2011 Praise Worthy Prize S.r.l. - All rights reserved.......Many demand side resources have the potential to provide fast and low cost balancing services. Switching these devices on and off can be executed in seconds and have limited consequences for the customers if the duration is not long. With carefully designed market rules, tens of thousands...

  20. Multiagent system in automatic light power balance in optical networks

    Science.gov (United States)

    Å lapák, Martin; Hůla, Miloslav

    2013-09-01

    This article deals with automatic power balancing along an optical line. For optimal transmission of an optical signal it is important to achieve certain parameters such as the signal to noise ratio or chromatic dispersion and also the sufficient output power level of in-line amplifiers. Pump diodes in amplifiers suffer from aging of material and therefore the driving current of pump diodes has to be accordingly increased to achieve the same gain as in the moment when the pump diodes were new. The use of a minimal required driving current leads to the longer lifetime of optical pumps. Therefore an automatic power balance is one of the methods used to achieve these goals.

  1. The Notion of Structural Balance and the International System.

    Science.gov (United States)

    1972-01-01

    the theory of directed graphs is contained in Dorwin Cartwright and Frank Harary, "Structural Balance: A Generalization of Heider’s Theory," Psy ical...316- 323; and Frank Harary, Robert Z.Norman, and Dorwin Cartwright , Structural Models: An Introduction to the Theory of Directed Graphs (New York: john...concept is Harary, op. cit., 1959; and Harary, Norman and Cartwright , op. cit. p.-.,. 34 8James N. Rosenau, "Pre-theories and ’heories of Foreign

  2. Surface N Balances in Agricultural Crop production systems in China for the period 1980-2015

    NARCIS (Netherlands)

    Sun, B.; Shen, R.P.; Bouwman, A.F.

    2008-01-01

    Surface nitrogen (N) balances for China's crop production systems were estimated using statistical data collected from 1980 to 2004 at the national and provincial scale and from 1994 to 1999 at the county level. There was a surplus N balance throughout these periods, but the surplus was nearly stabl

  3. Linear quadratic Gaussian balancing for discrete-time infinite-dimensional linear systems

    NARCIS (Netherlands)

    Opmeer, MR; Curtain, RF

    2004-01-01

    In this paper, we study the existence of linear quadratic Gaussian (LQG)-balanced realizations for discrete-time infinite-dimensional systems. LQG-balanced realizations are those for which the smallest nonnegative self-adjoint solutions of the control and filter Riccati equations are equal. We show

  4. Development of management quality system for metallurgical enterprise based on Balanced Scorecard with limiting factors

    Directory of Open Access Journals (Sweden)

    Galina Ledneva

    2009-12-01

    Full Text Available The article considers inefficiency of the existing quality management systems (QMS based on standards ISO series 9000. The authors offer integrated QMS with limiting factors on Balanced Scorecard. The Balanced Scorecard with limiting factors helps to efficiently direct process of continuous improvement and achieve top-priority criteria in quality management domain.

  5. Detecting asymmetries in balance control in Parkinson's disease patients with system identification techniques.

    NARCIS (Netherlands)

    Boonstra, Tjitske; van Asseldonk, Edwin H.F.; van Vugt, J.P.P.; van der Kooij, Herman; Bloem, B.B.

    2009-01-01

    Objective: To test the hypothesis that balance control in Parkinson’s disease (PD) is asymmetrically affected using system identification techniques. Background: PD is an asymmetrical disease. It is unknown whether axial symptoms, such as impaired balance, also show asymmetry. Clinical scales used t

  6. Recent development of hydrodynamic modeling

    Science.gov (United States)

    Hirano, Tetsufumi

    2014-09-01

    In this talk, I give an overview of recent development in hydrodynamic modeling of high-energy nuclear collisions. First, I briefly discuss about current situation of hydrodynamic modeling by showing results from the integrated dynamical approach in which Monte-Carlo calculation of initial conditions, quark-gluon fluid dynamics and hadronic cascading are combined. In particular, I focus on rescattering effects of strange hadrons on final observables. Next I highlight three topics in recent development in hydrodynamic modeling. These include (1) medium response to jet propagation in di-jet asymmetric events, (2) causal hydrodynamic fluctuation and its application to Bjorken expansion and (3) chiral magnetic wave from anomalous hydrodynamic simulations. (1) Recent CMS data suggest the existence of QGP response to propagation of jets. To investigate this phenomenon, we solve hydrodynamic equations with source term which exhibits deposition of energy and momentum from jets. We find a large number of low momentum particles are emitted at large angle from jet axis. This gives a novel interpretation of the CMS data. (2) It has been claimed that a matter created even in p-p/p-A collisions may behave like a fluid. However, fluctuation effects would be important in such a small system. We formulate relativistic fluctuating hydrodynamics and apply it to Bjorken expansion. We found the final multiplicity fluctuates around the mean value even if initial condition is fixed. This effect is relatively important in peripheral A-A collisions and p-p/p-A collisions. (3) Anomalous transport of the quark-gluon fluid is predicted when extremely high magnetic field is applied. We investigate this possibility by solving anomalous hydrodynamic equations. We found the difference of the elliptic flow parameter between positive and negative particles appears due to the chiral magnetic wave. Finally, I provide some personal perspective of hydrodynamic modeling of high energy nuclear collisions

  7. System Identification and Automatic Mass Balancing of Ground-Based Three-Axis Spacecraft Simulator

    Science.gov (United States)

    2006-08-01

    System Identification and Automatic Mass Balancing of Ground-Based Three-Axis Spacecraft Simulator Jae-Jun Kim∗ and Brij N. Agrawal † Department of...TITLE AND SUBTITLE System Identification and Automatic Mass Balancing of Ground-Based Three-Axis Spacecraft Simulator 5a. CONTRACT NUMBER 5b...and Dynamics, Vol. 20, No. 4, July-August 1997, pp. 625-632. 6Schwartz, J. L. and Hall, C. D., “ System Identification of a Spherical Air-Bearing

  8. ANALYTIC NETWORK PROCESS AND BALANCED SCORECARD APPLIED TO THE PERFORMANCE EVALUATION OF PUBLIC HEALTH SYSTEMS

    Directory of Open Access Journals (Sweden)

    Marco Aurélio Reis dos Santos

    2015-08-01

    Full Text Available The performance of public health systems is an issue of great concern. After all, to assure people's quality of life, public health systems need different kinds of resources. Balanced Scorecard provides a multi-dimensional evaluation framework. This paper presents the application of the Analytic Network Process and Balanced Scorecard in the performance evaluation of a public health system in a typical medium-sized Southeastern town in Brazil.

  9. WALK-ASSISTING BALANCE SYSTEM OF THE EXOSKELETON ROBOT FOR DISABLED PEOPLE

    Institute of Scientific and Technical Information of China (English)

    Yin Yuehong; Zhou Chunlin; Song Jiaren; Chen Shiyi; Han Tianpu; Zhou Chen

    2004-01-01

    A novel methodology for a walk-assisting balance system of the exoskeleton robot for disabled people is presented.The experiment on the walk-assisting balance system is implemented using a mini-type ropewalker robot.The mechanism of the ropewalker robot is designed,its dynamic model is built,and its control system based on PWM is developed.The emulations in Matlab and the results of experiments prove that this methodology is effective.

  10. Non-boost-invariant dissipative hydrodynamics

    CERN Document Server

    Florkowski, Wojciech; Strickland, Michael; Tinti, Leonardo

    2016-01-01

    The one-dimensional non-boost-invariant evolution of the quark-gluon plasma, presumably produced during the early stages of heavy-ion collisions, is analyzed within the frameworks of viscous and anisotropic hydrodynamics. We neglect transverse dynamics and assume homogeneous conditions in the transverse plane but, differently from Bjorken expansion, we relax longitudinal boost invariance in order to study the rapidity dependence of various hydrodynamical observables. We compare the results obtained using several formulations of second-order viscous hydrodynamics with a recent approach to anisotropic hydrodynamics, which treats the large initial pressure anisotropy in a non-perturbative fashion. The results obtained with second-order viscous hydrodynamics depend on the particular choice of the second-order terms included, which suggests that the latter should be included in the most complete way. The results of anisotropic hydrodynamics and viscous hydrodynamics agree for the central hot part of the system, ho...

  11. Storage and balancing synergies in a fully or highly renewable pan-European power system

    DEFF Research Database (Denmark)

    Rasmussen, Morten Grud; Bruun Andresen, Gorm; Greiner, Martin

    2012-01-01

    Through a parametric time-series analysis of eight years of hourly data, we quantify the storage size and balancing energy needs for highly and fully renewable European power systems for different levels and mixes of wind and solar energy. By applying a dispatch strategy that minimizes...... that combined with a low-efficiency hydrogen storage and a level of balancing equal to what is today provided by storage lakes, it is sufficient to meet the European electricity demand in a fully renewable power system where the average power generation from combined wind and solar exceeds the demand by only...... the balancing energy needs for a given storage size, the interplay between storage and balancing is quantified, providing a hard upper limit on their synergy. An efficient but relatively small storage reduces balancing energy needs significantly due to its influence on intra-day mismatches. Furthermore, we show...

  12. New PN Even Balanced Sequences for Spread-Spectrum Systems

    Directory of Open Access Journals (Sweden)

    Inácio JAL

    2005-01-01

    Full Text Available A new class of pseudonoise even balanced (PN-EB binary spreading sequences is derived from existing classical odd-length families of maximum-length sequences, such as those proposed by Gold, by appending or inserting one extra-zero element (chip to the original sequences. The incentive to generate large families of PN-EB spreading sequences is motivated by analyzing the spreading effect of these sequences from a natural sampling point of view. From this analysis a new definition for PG is established, from which it becomes clear that very high processing gains (PGs can be achieved in band-limited direct-sequence spread-spectrum (DSSS applications by using spreading sequences with zero mean, given that certain conditions regarding spectral aliasing are met. To obtain large families of even balanced (i.e., equal number of ones and zeros sequences, two design criteria are proposed, namely the ranging criterion (RC and the generating ranging criterion (GRC. PN-EB sequences in the polynomial range are derived using these criteria, and it is shown that they exhibit secondary autocorrelation and cross-correlation peaks comparable to the sequences they are derived from. The methods proposed not only facilitate the generation of large numbers of new PN-EB spreading sequences required for CDMA applications, but simultaneously offer high processing gains and good despreading characteristics in multiuser SS scenarios with band-limited noise and interference spectra. Simulation results are presented to confirm the respective claims made.

  13. Integrated Balanced BPSK Modulator for Millimeter Wave Systems

    Directory of Open Access Journals (Sweden)

    Asok De

    2007-10-01

    Full Text Available This paper details the design of integrated balanced PSK modulator using finline coplanar line hybrid junction. The PSK signal output is in suspended stripline with incident wave carrier in finline. Schottky barrier Diode MA4E2037 has been used for modulation. The balanced configuration offers high isolation between the carrier input port and the modulated carrier output port and thus the pulse width variations and amplitude deviations are suppressed. An insertion loss imbalance of ±1.5 dB with an average loss of 2 dB in the two switching states has been achieved over 38.9 to 40 GHz. The phase imbalance is ±10 degrees with phase switching from 180 to 199 degrees As the PSK output signal is in suspended stripline, two BPSK modulators can be easily combined together to work as QPSK modulator.

  14. Effect of reversal of the flow direction on hydrodynamic characteristics and plants cultivated in constructed wetland systems

    Directory of Open Access Journals (Sweden)

    Gheila Corrêa Ferres Baptestini

    2016-01-01

    Full Text Available The objective of the present study was to evaluate the effect of reversal of the flow direction, when used the surface flow as an operating criteria, on hydrodynamic characteristics and plants grown in horizontal subsurface-flow constructed wetland systems (HSF-CWs. For this purpose, six HSF-CWs were used: two non-cultivated (HSF-CWs 1 and 4, two cultivated with Tifton 85 grass (Cynodon spp. (HSF-CWs 2 and 5 and two cultivated with Alternanthera (Alternanthera philoxeroides (HSF-CWs 3 and 6. It was made a reversal in the flow direction of the HSF-CWs 1, 2 and 3. The reversal of the wastewater flow direction was performed when the superficial flow of the wastewater applied (SF reached 50% of the length of the HSF-CWs. There was a single reversal for each system, on different dates. Reversing the flow direction promoted distinction on the dry matter yield of Tifton 85 grass. This was not observed in HSF-CWs cultivated with Alternanthera. The reversal of the wastewater flow direction promoted, in principle, the extinction of the SF advance in the HSF-CWs, but did not prevent its return. Waiting for the SF to reach 50% of the length was not the best criterion for reversing the flow direction.

  15. Workload Balancing on Heterogeneous Systems: A Case Study of Sparse Grid Interpolation

    KAUST Repository

    Muraraşu, Alin

    2012-01-01

    Multi-core parallelism and accelerators are becoming common features of today’s computer systems, as they allow for computational power without sacrificing energy efficiency. Due to heterogeneity, tuning for each type of compute unit and adequate load balancing is essential. This paper proposes static and dynamic solutions for load balancing in the context of an application for visualizing high-dimensional simulation data. The application relies on the sparse grid technique for data compression. Its performance critical part is the interpolation routine used for decompression. Results show that our load balancing scheme allows for an efficient acceleration of interpolation on heterogeneous systems containing multi-core CPUs and GPUs.

  16. The Balanced Scorecard: A Management System for Wilford Hall Medical Center - The Premier Air Force Medical Enterprise

    Science.gov (United States)

    1999-04-01

    The Balanced Scorecard Management System (BSMS) at Wilford Hall Medical Center (WHMC) is a strategic management and measurement system that...prompted the study to a look at the statement of the problem, the author explores the history and use of the balanced scorecard concept in civilian...was an Intranet-based, database automated, Balanced Scorecard Management System.

  17. Balance Sheet and Analysis of Reactive Power Demand in the Polish Power System

    Directory of Open Access Journals (Sweden)

    Aleksander Kot

    2013-03-01

    Full Text Available The paper presents an analysis of the balance sheet and the reactive power demand of the Polish Power System. Reactive power balance sheets were made for the specific operating conditions of the system: the last winter peak, summer peak and summer off peak load. The basis of the study was load flow models and selected load flow calculation results. In addition, changes in demand for active and reactive power in recent years were presented.

  18. Cost of photovoltaic energy systems as determined by balance-of-system costs

    Science.gov (United States)

    Rosenblum, L.

    1978-01-01

    The effect of the balance-of-system (BOS), i.e., the total system less the modules, on photo-voltaic energy system costs is discussed for multikilowatt, flat-plate systems. Present BOS costs are in the range of 10 to 16 dollars per peak watt (1978 dollars). BOS costs represent approximately 50% of total system cost. The possibility of future BOS cost reduction is examined. It is concluded that, given the nature of BOS costs and the lack of comprehensive national effort focussed on cost reduction, it is unlikely that BOS costs will decline greatly in the next several years. This prognosis is contrasted with the expectations of the Department of Energy National Photovoltaic Program goals and pending legislation in the Congress which require a BOS cost reduction of an order of magnitude or more by the mid-1980s.

  19. Mechanical design of a rotary balance system for NASA. Langley Research Center's vertical spin tunnel

    Science.gov (United States)

    Allred, J. W.; Fleck, V. J.

    1992-01-01

    A new lightweight Rotary Balance System is presently being fabricated and installed as part of a major upgrade to the existing 20 Foot Vertical Spin Tunnel. This upgrade to improve model testing productivity of the only free spinning vertical wind tunnel includes a modern fan/drive and tunnel control system, an updated video recording system, and the new rotary balance system. The rotary balance is a mechanical apparatus which enables the measurement of aerodynamic force and moment data under spinning conditions (100 rpm). This data is used in spin analysis and is vital to the implementation of large amplitude maneuvering simulations required for all new high performance aircraft. The new rotary balance system described in this report will permit greater test efficiency and improved data accuracy. Rotary Balance testing with the model enclosed in a tare bag can also be performed to obtain resulting model forces from the spinning operation. The rotary balance system will be stored against the tunnel sidewall during free flight model testing.

  20. Storage Balancing in Self-organizing Multimedia Delivery Systems

    CERN Document Server

    Sobe, Anita; Böszörmenyi, Laszlo

    2011-01-01

    Many of the current bio-inspired delivery networks set their focus on search, e.g., by using artificial ants. If the network size and, therefore, the search space gets too large, the users experience high delays until the requested content can be consumed. In previous work, we proposed different replication strategies to reduce the search space. In this report we further evaluate measures for storage load balancing, because peers are most likely limited in space. We periodically apply clean-ups if a certain storage level is reached. For our evaluations we combine the already introduced replication measures with least recently used (LRU), least frequently used (LFU) and a hormone-based clean-up. The goal is to elaborate a combination that leads to low delays while the replica utilization is high.

  1. New PN Even Balanced Sequences for Spread-Spectrum Systems

    Directory of Open Access Journals (Sweden)

    Inácio J. A. L.

    2005-01-01

    Full Text Available A new class of pseudonoise even balanced (PN-EB binary spreading sequences is derived from existing classical odd-length families of maximum-length sequences, such as those proposed by Gold, by appending or inserting one extra-zero element (chip to the original sequences. The incentive to generate large families of PN-EB spreading sequences is motivated by analyzing the spreading effect of these sequences from a natural sampling point of view. From this analysis a new definition for PG is established, from which it becomes clear that very high processing gains (PGs can be achieved in band-limited direct-sequence spread-spectrum (DSSS applications by using spreading sequences with zero mean, given that certain conditions regarding spectral aliasing are met. To obtain large families of even balanced (i.e., equal number of ones and zeros sequences, two design criteria are proposed, namely the ranging criterion (RC and the generating ranging criterion (GRC. PN-EB sequences in the polynomial range 3 ≤ n ≤ 6 are derived using these criteria, and it is shown that they exhibit secondary autocorrelation and cross-correlation peaks comparable to the sequences they are derived from. The methods proposed not only facilitate the generation of large numbers of new PN-EB spreading sequences required for CDMA applications, but simultaneously offer high processing gains and good despreading characteristics in multiuser SS scenarios with band-limited noise and interference spectra. Simulation results are presented to confirm the respective claims made.

  2. Responsiveness of the Balance Evaluation Systems Test (BESTest) in People With Subacute Stroke.

    Science.gov (United States)

    Chinsongkram, Butsara; Chaikeeree, Nithinun; Saengsirisuwan, Vitoon; Horak, Fay B; Boonsinsukh, Rumpa

    2016-10-01

    The reliability and convergent validity of the Balance Evaluation Systems Test (BESTest) in people with subacute stroke have been established, but its responsiveness to rehabilitation has not been examined. The study objective was to compare the responsiveness of the BESTest with those of other clinical balance tools in people with subacute stroke. This was a prospective cohort study. Forty-nine people with subacute stroke (mean age=57.8 years, SD=11.8) participated in this study. Five balance measures-the BESTest, the Mini-BESTest, the Berg Balance Scale, the Postural Assessment Scale for Stroke Patients, and the Community Balance and Mobility Scale (CB&M)-were used to measure balance performance before and after rehabilitation or before discharge from the hospital, whichever came first. The internal responsiveness of each balance measure was classified with the standardized response mean (SRM); changes in Berg Balance Scale scores of greater than 7 were used as the external standard for determining the external responsiveness. Analysis of the receiver operating characteristic curve was used to determine the accuracy and cutoff scores for identifying participants with balance improvement. Participants received 13.7 days (SD=9.3, range=5-44) of physical therapy rehabilitation. The internal responsiveness of all balance measures, except for the CB&M, was high (SRM=0.9-1.2). The BESTest had a higher SRM than the Mini-BESTest and the CB&M, indicating that the BESTest was more sensitive for detecting balance changes than the Mini-BESTest and the CB&M. In addition, compared with other balance measures, the BESTest had no floor, ceiling, or responsive ceiling effects. The results also indicated that the percentage of participants with no change in scores after rehabilitation was smaller with the BESTest than with the Mini-BESTest and the CB&M. With regard to the external responsiveness, the BESTest had higher accuracy, sensitivity, specificity, and posttest accuracy than

  3. Hydrodynamics in the wake of a pitching foil

    CERN Document Server

    Fernandez-Prats, R

    2013-01-01

    The effect of flexibility on the hydrodynamic loads and on the flow structures generated on a rectangular foil when oscillating in pitch has been studied. Hydrodynamic loads were measured with a 6-axes balance, and the flow structures were investigated by using a Digital Particle Image Velocimetry (DPIV). It is known from nature's fin based propulsion mechanisms, that appendage stiffness plays an important role in their propulsive efficiency. We have studied four different stiffnesses, ranging from completely rigid to highly flexible. Optimal efficiency has been observed for an intermediate case. In this case, a moderately stronger trailing-edge vortex system takes place. A very high level of flexibility of the foil results in a reduction of efficiency.

  4. Workload balancing capability of pull systems in MTO production

    NARCIS (Netherlands)

    Germs, R.; Riezebos, J.

    2010-01-01

    Pull systems focusing on throughput time control and applicable in situations with high variety and customisation are scarce. This paper compares three unit-based pull systems that can cope with such situations: POLCA, CONWIP and m-CONWIP. These systems control the shop floor throughput time of orde

  5. Workload balancing capability of pull systems in MTO production

    NARCIS (Netherlands)

    Germs, R.; Riezebos, J.

    2010-01-01

    Pull systems focusing on throughput time control and applicable in situations with high variety and customisation are scarce. This paper compares three unit-based pull systems that can cope with such situations: POLCA, CONWIP and m-CONWIP. These systems control the shop floor throughput time of

  6. The Balanced Scorecard: a strategic management system for multi-sector collaboration and strategy implementation.

    Science.gov (United States)

    Inamdar, S N; Kaplan, R S; Jones, M L; Menitoff, R

    2000-01-01

    This article illustrates the application of the Balanced Scorecard, a method more commonly associated with the business world, to a nonprofit multisector National Women's Health Quality Initiative (NWHQI). The article delineates the following multiple uses of the Balanced Scorecard for the NWHQI effort: Set NWHQI strategy and structure. Provide the framework and principles to implement NWHQI's strategy. Develop a measurement system to assess the progress and success of NWHQI's strategy. Serve as a collaboration mechanism for multisector stakeholders. Advance women's health knowledge base. This article concludes by sharing key insights regarding the utility of the Balanced Scorecard to promote the success of this nationwide women's health quality initiative.

  7. Fluidization of Wet Granulates under Hydrodynamic Shear

    CERN Document Server

    Battiato, I

    2012-01-01

    We investigate the fluidization threshold of three-dimensional cohesive granulates under hydrodynamic shear forces exerted by a creeping ow. A continuum model of flow through porous media provides an analytical expression for the average drag force on a single grain. The balance equation for the forces and a force propagation model are then used to investigate the effects of porosity and packing structure on the stability of the pile. We obtain a closed-form expression for the fluidization threshold of a regular packing of mono-disperse frictionless cohesive spherical grains in a planar fracture. The compound effect of structural (packing orientation and porosity) and dynamical properties of the system on its stability is quantified.

  8. Hydrodynamic directional control of liquid metal droplets within a microfluidic flow focusing system

    Science.gov (United States)

    Gol, Berrak; Kurdzinski, Michael E.; Tovar-Lopez, Francisco J.; Petersen, Phred; Mitchell, Arnan; Khoshmanesh, Khashayar

    2016-04-01

    Here, we investigate the directional control of Galinstan liquid metal droplets when transferring from the high-viscosity glycerol core into the parallel low-viscosity NaOH sheath streams within a flow focusing microfluidic system. In the presence of sufficient flow mismatch between the sheath streams, the droplets are driven toward the higher velocity interface and cross the interface under the influence of surface tension gradient. A minimum flow mismatch of 125 μl/min is required to enable the continuous transfer of droplets toward the desired sheath stream. The response time of droplets, the time required to change the direction of droplet transfer, is governed by the response time of the syringe pump driven microfluidic system and is found to be 3.3 and 8.8 s when increasing and decreasing the flow rate of sheath stream, respectively.

  9. Recent Developments In Theory Of Balanced Linear Systems

    Science.gov (United States)

    Gawronski, Wodek

    1994-01-01

    Report presents theoretical study of some issues of controllability and observability of system represented by linear, time-invariant mathematical model of the form. x = Ax + Bu, y = Cx + Du, x(0) = xo where x is n-dimensional vector representing state of system; u is p-dimensional vector representing control input to system; y is q-dimensional vector representing output of system; n,p, and q are integers; x(0) is intial (zero-time) state vector; and set of matrices (A,B,C,D) said to constitute state-space representation of system.

  10. Dynamic Analysis of Hydrodynamic Behavior of A Flatfish Cage System Under Wave Conditions

    Institute of Scientific and Technical Information of China (English)

    崔勇; 关长涛; 万荣; 黄滨; 李娇

    2014-01-01

    This paper presents a simulation model based on the finite element method. The method is used to analyze the motion response and mooring line tension of the flatfish cage system in waves. The cage system consists of top frames, netting, mooring lines, bottom frames, and floats. A series of scaled physical model tests in regular waves are conducted to verify the numerical model. The comparison results show that the simulated and the experimental results agree well under the wave conditions, and the maximum pitch of the bottom frame with two orientations is about 12º. The motion process of the whole cage system in the wave can be described with the computer visualized technology. Then, the mooring line tensions and the motion of the bottom frame with three kinds of weight are calculated under different wave conditions. According to the numerical results, the differences in mooring line tensions of flatfish cages with three weight modes are indistinct. The maximum pitch of the bottom frame decreases with the increase of the bottom weight.

  11. Hydrodynamic shocks in microroller suspensions

    Science.gov (United States)

    Delmotte, Blaise; Driscoll, Michelle; Chaikin, Paul; Donev, Aleksandar

    2017-09-01

    We combine experiments, large-scale simulations, and continuum models to study the emergence of coherent structures in a suspension of magnetically driven microrollers sedimented near a floor. Collective hydrodynamic effects are predominant in this system, leading to strong density-velocity coupling. We characterize a uniform suspension and show that density waves propagate freely in all directions in a dispersive fashion. When sharp density gradients are introduced in the suspension, we observe the formation of a shock. Unlike Burgers' shocklike structures observed in other active and driven confined hydrodynamic systems, the shock front in our system has a well-defined finite width and moves rapidly compared to the mean suspension velocity. We introduce a continuum model demonstrating that the finite width of the front is due to far-field nonlocal hydrodynamic interactions and governed by a geometric parameter, the average particle height above the floor.

  12. Constructing an Efficient and Balanced European Patent System: “Muddling through”

    DEFF Research Database (Denmark)

    Schovsbo, Jens Hemmingsen

    2011-01-01

    The paper discusses ways to construct a more efficient and balanced European patent system. It identifies and describes challenges relating to innovation, to non-economic issues and to governance. In order to improve the patent system, a cautious approach of “Muddling through” is recommended. Mor...... access to patented inventions and enhancement of governance.......The paper discusses ways to construct a more efficient and balanced European patent system. It identifies and describes challenges relating to innovation, to non-economic issues and to governance. In order to improve the patent system, a cautious approach of “Muddling through” is recommended. More...

  13. A balanced Kalman filter ocean data assimilation system with application to the South Australian Sea

    Science.gov (United States)

    Li, Yi; Toumi, Ralf

    2017-08-01

    In this paper, an Ensemble Kalman Filter (EnKF) based regional ocean data assimilation system has been developed and applied to the South Australian Sea. This system consists of the data assimilation algorithm provided by the NCAR Data Assimilation Research Testbed (DART) and the Regional Ocean Modelling System (ROMS). We describe the first implementation of the physical balance operator (temperature-salinity, hydrostatic and geostrophic balance) to DART, to reduce the spurious waves which may be introduced during the data assimilation process. The effect of the balance operator is validated in both an idealised shallow water model and the ROMS model real case study. In the shallow water model, the geostrophic balance operator eliminates spurious ageostrophic waves and produces a better sea surface height (SSH) and velocity analysis and forecast. Its impact increases as the sea surface height and wind stress increase. In the real case, satellite-observed sea surface temperature (SST) and SSH are assimilated in the South Australian Sea with 50 ensembles using the Ensemble Adjustment Kalman Filter (EAKF). Assimilating SSH and SST enhances the estimation of SSH and SST in the entire domain, respectively. Assimilation with the balance operator produces a more realistic simulation of surface currents and subsurface temperature profile. The best improvement is obtained when only SSH is assimilated with the balance operator. A case study with a storm suggests that the benefit of the balance operator is of particular importance under high wind stress conditions. Implementing the balance operator could be a general benefit to ocean data assimilation systems.

  14. Impact of the Group Lifestyle Balance (GLB) Program on Diabetes Prevention in the Military Health System

    Science.gov (United States)

    2016-05-20

    TITLE OF MATERIAL TO BE PUBLISHED OR PRESENTED Impact of the Group Lifestyle Balance (GLB) Program on Diabetes Prevention in the Military Health...of 3 Pages IMPACT OF THE GROUP LIFESTYLE BALANCE (GLB) PROGRAM ON DIABETES PREVENTION IN THE MILITARY HEALTH SYSTEM Maj Richard Davis, MD1; Col Mark...The Diabetes Prevention Program (OPP) demonstrated lifestyle intervention programs were effective. The GLB program translated the OPP curriculum

  15. Numerical Analysis of Hydrodynamic Behaviors of Two Net Cages with Grid Mooring System Under Wave Action

    Institute of Scientific and Technical Information of China (English)

    CHEN Chang-ping; ZHAO Yun-peng; LI Yu-cheng; DONG Guo-hai; ZHENG Yan-na

    2012-01-01

    Based on rigid kinematics theory and lumped mass method,a mathematical model of the two net cages of grid mooring system under waves is developed.In order to verify the numerical model,a series of physical model tests have been carried out.According to the comparisons between the simulated and the experimental results,it can be found that the simulated and the experimental results agree well in each wave condition.Then,the forces on the mooring lines and the floating collar movement are calculated under different wave conditions.Numerical results show that under the same condition,the forces on the bridle ropes are the largest,followed by forces on the main ropes and the grid ropes.The horizontal and the vertical float collar motion amplitudes increase with the increase of wave height,while the relationship of the horizontal motion amplitude and the wave period is indistinct.The vertical motion amplitude of the two cages is almost the same,while on the respect of horizontal motion amplitude,cage B (behind cage A,as shown in Fig.4) moves much farther than cage A under the same wave condition.The inclination angle of the floating system both in clockwise alongy axis and the counter one enlarges a little with the increase of wave height.

  16. Implications of Upwells as Hydrodynamic Jets in a Pulse Jet Mixed System

    Energy Technology Data Exchange (ETDEWEB)

    Pease, Leonard F. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bamberger, Judith A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Minette, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2017-02-28

    This report evaluates the physics of the upwell flow in pulse jet mixed systems in the Hanford Tank Waste Treatment and Immobilization Plant (WTP). Although the initial downward flow and radial flow from jets characteristic of pulse jet mixers (PJMs) has been analyzed, the upwells have received considerably less attention despite having significant implications for vessel mixing. Do the upwells behave like jets? How do the upwells scale? When will the central upwell break through? What proportion of the vessel is blended by the upwells themselves? Indeed, how the physics of the central upwell is affected by multiple PJMs (e.g., six in the proposed mixing vessels), non-Newtonian rheology, and significant multicomponent solids loadings remain unexplored.

  17. Management Information System Based on the Balanced Scorecard

    Science.gov (United States)

    Kettunen, Juha; Kantola, Ismo

    2005-01-01

    Purpose: This study seeks to describe the planning and implementation in Finland of a campus-wide management information system using a rigorous planning methodology. Design/methodology/approach: The structure of the management information system is planned on the basis of the management process, where strategic management and the balanced…

  18. Constrained Balancing of Two Industrial Rotor Systems: Least Squares and Min-Max Approaches

    Directory of Open Access Journals (Sweden)

    Bin Huang

    2009-01-01

    Full Text Available Rotor vibrations caused by rotor mass unbalance distributions are a major source of maintenance problems in high-speed rotating machinery. Minimizing this vibration by balancing under practical constraints is quite important to industry. This paper considers balancing of two large industrial rotor systems by constrained least squares and min-max balancing methods. In current industrial practice, the weighted least squares method has been utilized to minimize rotor vibrations for many years. One of its disadvantages is that it cannot guarantee that the maximum value of vibration is below a specified value. To achieve better balancing performance, the min-max balancing method utilizing the Second Order Cone Programming (SOCP with the maximum correction weight constraint, the maximum residual response constraint as well as the weight splitting constraint has been utilized for effective balancing. The min-max balancing method can guarantee a maximum residual vibration value below an optimum value and is shown by simulation to significantly outperform the weighted least squares method.

  19. Hydrodynamic Study of a Hollow Fiber Membrane System Using Experimental and Numerical Derived Surface Shear Stresses

    DEFF Research Database (Denmark)

    Ratkovich, Nicolas Rios; Hunze, M.; Nopens, I.

    2012-01-01

    : 0.25 – 0.49 Pa) with an error of less than 5 %; (ii) high shear stresses (i.e. 90th percentile) predictions were much less accurate (model: 0.60 – 1.23 Pa; experimental: 1.04 – 1.90 Pa) with an error up to 38 %. This was attributed to the fact that the CFD model only considers the two-phase flow (50......Computational Fluids Dynamics (CFD) models can be used to gain insight into the shear stresses induced by air sparging on submerged hollow fiber Membrane BioReactor (MBR) systems. It was found that the average range of shear stresses obtained by the CFD model (0.30 – 0.60 Pa) and experimentally (0.......39 – 0.69 Pa) were in good agreement, with an error less that 15 %. Based on comparison of the cumulative frequency distribution of shear stresses from experiments and simulation: (i) moderate shear stresses (i.e. 50th percentile) were found to be accurately predicted (model: 0.24 – 0.45 Pa; experimental...

  20. Experimental and computational determination of the hydrodynamics of mini vessel dissolution testing systems.

    Science.gov (United States)

    Wang, Bing; Armenante, Piero M

    2016-08-20

    Mini vessel dissolution testing systems consist of a small-scale 100-mL vessel with a small paddle impeller, similar to the USP Apparatus 2, and are typically utilized when only small amounts of drug product are available during drug development. Despite their common industrial use, mini vessels have received little attention in the literature. Here, Computational Fluid Dynamics (CFD) was used to predict velocity profiles, flow patterns, and strain rate distribution in a mini vessel at different agitation speeds. These results were compared with experimental velocity measurements obtained with Particle Image Velocimetry (PIV). Substantial agreement was observed between CFD results and PIV data. The flow is strongly dominated by the tangential velocity component. Secondary flows consist of vertical upper and lower recirculation loops above and below the impeller. A low recirculation zone was observed in the lower part of the vessel. The radial and axial velocities in the region just below the impeller are very small especially in the innermost core zone below the paddle, where tablet dissolution occurs. Increasing agitation speed reduces the radius of this zone, which is always present at any speed, and only modestly increases the tangential flow intensity, with significant implication for dissolution testing in mini vessels.

  1. Hydrodynamic Study of a Hollow Fiber Membrane System Using Experimental and Numerical Derived Surface Shear Stresses

    DEFF Research Database (Denmark)

    Ratkovich, Nicolas Rios; Hunze, M.; Nopens, I.

    2012-01-01

    Computational Fluids Dynamics (CFD) models can be used to gain insight into the shear stresses induced by air sparging on submerged hollow fiber Membrane BioReactor (MBR) systems. It was found that the average range of shear stresses obtained by the CFD model (0.30 – 0.60 Pa) and experimentally (0.......39 – 0.69 Pa) were in good agreement, with an error less that 15 %. Based on comparison of the cumulative frequency distribution of shear stresses from experiments and simulation: (i) moderate shear stresses (i.e. 50th percentile) were found to be accurately predicted (model: 0.24 – 0.45 Pa; experimental......: 0.25 – 0.49 Pa) with an error of less than 5 %; (ii) high shear stresses (i.e. 90th percentile) predictions were much less accurate (model: 0.60 – 1.23 Pa; experimental: 1.04 – 1.90 Pa) with an error up to 38 %. This was attributed to the fact that the CFD model only considers the two-phase flow (50...

  2. Hydrodynamically driven colloidal assembly in dip coating.

    Science.gov (United States)

    Colosqui, Carlos E; Morris, Jeffrey F; Stone, Howard A

    2013-05-01

    We study the hydrodynamics of dip coating from a suspension and report a mechanism for colloidal assembly and pattern formation on smooth substrates. Below a critical withdrawal speed where the coating film is thinner than the particle diameter, capillary forces induced by deformation of the free surface prevent the convective transport of single particles through the meniscus beneath the film. Capillary-induced forces are balanced by hydrodynamic drag only after a minimum number of particles assemble within the meniscus. The particle assembly can thus enter the thin film where it moves at nearly the withdrawal speed and rapidly separates from the next assembly. The interplay between hydrodynamic and capillary forces produces periodic and regular structures below a critical ratio Ca(2/3)/sqrt[Bo] particles in suspension. The hydrodynamically driven assembly documented here is consistent with stripe pattern formations observed experimentally in dip coating.

  3. Evaluation of surface energy and radiation balance systems on the Konza Prairie

    Science.gov (United States)

    Fritschen, Leo J.

    1987-01-01

    Four Surface Energy and Radiation Balance Systems (SERBS) were installed and operated for two weeks in Kansas during July of 1986. Surface energy and radiation balances were investigated on six sites on the Konza Prairie about 3 km south of Manhattan, Kansas. Measurements were made to allow the computation of these radiation components: total solar and diffuse radiation, reflected solar radiation, net radiation, and longwave radiation upward and downward. Measurements were made to allow the computation of the sensible and latent heat fluxes by the Bowen ratio method using differential psychrometers on automatic exchange mechanisms. The report includes a description of the experimental sites, data acquisition systems and sensors, data acquisitions system operating instructions, and software used for data acquisition and analysis. In addition, data listings and plots of the energy balance components for all days and systems are given.

  4. Impact balance-of-system costs on photovoltaic electric power systems

    Energy Technology Data Exchange (ETDEWEB)

    Saha, H.; Basu, P.; Mukhopadhyay, K.

    1983-03-01

    A simple method based on the balance-of-system (BOS) costs is proposed for computing the allowable solar cell module cost and efficiency for typical applications of photovoltaic electric power systems: microirrigation and a rural electric supply. It is shown that in India the allowable module cost of cell modules with a conversion efficiency of about 5% is about U.S. $2 Wsub(p)/sup -1/ (1980) for microirrigation and about U.S. $0.8 Wsub(p)/sup -1/ for a rural electricity centre. It is further observed that relatively low BOS costs in India and similar places tend to make the allowable module cost become invariant with the efficiency, thus permitting solar cell modules of lower efficiency (5%) to become commercially viable for large-scale applications.

  5. Recent progress in anisotropic hydrodynamics

    CERN Document Server

    Strickland, Michael

    2016-01-01

    The quark-gluon plasma created in a relativistic heavy-ion collisions possesses a sizable pressure anisotropy in the local rest frame at very early times after the initial nuclear impact and this anisotropy only slowly relaxes as the system evolves. In a kinetic theory picture, this translates into the existence of sizable momentum-space anisotropies in the underlying partonic distribution functions, . In such cases, it is better to reorganize the hydrodynamical expansion by taking into account momentum-space anisotropies at leading-order in the expansion instead of as a perturbative correction to an isotropic distribution. The resulting anisotropic hydrodynamics framework has been shown to more accurately describe the dynamics of rapidly expanding systems such as the quark-gluon plasma. In this proceedings contribution, I review the basic ideas of anisotropic hydrodynamics, recent progress, and present a few preliminary phenomenological predictions for identified particle spectra and elliptic flow.

  6. Particle fluxes in the NW Iberian coastal upwelling system: Hydrodynamical and biological control

    Science.gov (United States)

    Zúñiga, D.; Villacieros-Robineau, N.; Salgueiro, E.; Alonso-Pérez, F.; Rosón, G.; Abrantes, F.; Castro, C. G.

    2016-07-01

    To better understand sources and transport of particulate material in the NW Iberian coastal upwelling system, a mooring line dotted with an automated PPS 4/3 sediment trap was deployed off Cape Silleiro at the base of the photic zone. The samples were collected from November 2008 through June 2012 over sampling periods of 4-12 days. Our study represents the first automated sediment trap database for the NW Iberian margin. The magnitude and composition of the settling material showed strong seasonal variability with the highest fluxes during the poleward and winter mixing periods (averages of 12.9±9.6 g m-2 d-1 and 5.6±5.6 g m-2 d-1 respectively), and comparatively lower fluxes (3.6±4.1 g m-2 d-1) for the upwelling season. Intensive deposition events registered during poleward and winter mixing periods were dominated by the lithogenic fraction (80±3%). They were associated to high energy wave-driven resuspension processes, due to the occurrence of south-westerly storms, and intense riverine inputs of terrestrial material from Minho and Douro rivers. On the other hand, during the spring - summer upwelling season, the share of biogenic compounds (organic matter, calcium carbonate (CaCO3), biogenic silica (bSiO2)) to downward fluxes was higher, reflecting an increase in pelagic sedimentation due to the seasonal intensification of primary production and negligible river inputs and wave-driven resuspended material. Otherwise, the large variations of biogenic settling particles were mainly modulated by upwelling intensity, which by means of upwelling filaments ultimately controlled the offshore transport of the organic carbon fixed by primary producers towards the adjacent ocean. Based on the average downward flux of organic carbon (212 mg C m-2 d-1) and considering an average primary production of 1013 mg C m-2 d-1 from literature, we estimated that about 21% of the fixed carbon is vertically exported during the upwelling season.

  7. The hydrodynamics of colloidal gelation.

    Science.gov (United States)

    Varga, Zsigmond; Wang, Gang; Swan, James

    2015-12-14

    Colloidal gels are formed during arrested phase separation. Sub-micron, mutually attractive particles aggregate to form a system spanning network with high interfacial area, far from equilibrium. Models for microstructural evolution during colloidal gelation have often struggled to match experimental results with long standing questions regarding the role of hydrodynamic interactions. In nearly all models, these interactions are neglected entirely. In the present work, we report simulations of gelation with and without hydrodynamic interactions between the suspended particles executed in HOOMD-blue. The disparities between these simulations are striking and mirror the experimental-theoretical mismatch in the literature. The hydrodynamic simulations agree with experimental observations, however. We explore a simple model of the competing transport processes in gelation that anticipates these disparities, and conclude that hydrodynamic forces are essential. Near the gel boundary, there exists a competition between compaction of individual aggregates which suppresses gelation and coagulation of aggregates which enhances it. The time scale for compaction is mildly slowed by hydrodynamic interactions, while the time scale for coagulation is greatly accelerated. This enhancement to coagulation leads to a shift in the gel boundary to lower strengths of attraction and lower particle concentrations when compared to models that neglect hydrodynamic interactions. Away from the gel boundary, differences in the nearest neighbor distribution and fractal dimension persist within gels produced by both simulation methods. This result necessitates a fundamental rethinking of how dynamic, discrete element models for gelation kinetics are developed as well as how collective hydrodynamic interactions influence the arrest of attractive colloidal dispersions.

  8. Quantitative performance targets by using balanced scorecard system: application to waste management and public administration.

    Science.gov (United States)

    Mendes, Paula; Nunes, Luis Miguel; Teixeira, Margarida Ribau

    2014-09-01

    This article demonstrates how decision-makers can be guided in the process of defining performance target values in the balanced scorecard system. We apply a method based on sensitivity analysis with Monte Carlo simulation to the municipal solid waste management system in Loulé Municipality (Portugal). The method includes two steps: sensitivity analysis of performance indicators to identify those performance indicators with the highest impact on the balanced scorecard model outcomes; and sensitivity analysis of the target values for the previously identified performance indicators. Sensitivity analysis shows that four strategic objectives (IPP1: Comply with the national waste strategy; IPP4: Reduce nonrenewable resources and greenhouse gases; IPP5: Optimize the life-cycle of waste; and FP1: Meet and optimize the budget) alone contribute 99.7% of the variability in overall balanced scorecard value. Thus, these strategic objectives had a much stronger impact on the estimated balanced scorecard outcome than did others, with the IPP1 and the IPP4 accounting for over 55% and 22% of the variance in overall balanced scorecard value, respectively. The remaining performance indicators contribute only marginally. In addition, a change in the value of a single indicator's target value made the overall balanced scorecard value change by as much as 18%. This may lead to involuntarily biased decisions by organizations regarding performance target-setting, if not prevented with the help of methods such as that proposed and applied in this study.

  9. Impact and Estimation of Balance Coordinate System Rotations and Translations in Wind-Tunnel Testing

    Science.gov (United States)

    Toro, Kenneth G.; Parker, Peter A.

    2017-01-01

    Discrepancies between the model and balance coordinate systems lead to biases in the aerodynamic measurements during wind-tunnel testing. The reference coordinate system relative to the calibration coordinate system at which the forces and moments are resolved is crucial to the overall accuracy of force measurements. This paper discusses sources of discrepancies and estimates of coordinate system rotation and translation due to machining and assembly differences. A methodology for numerically estimating the coordinate system biases will be discussed and developed. Two case studies are presented using this methodology to estimate the model alignment. Examples span from angle measurement system shifts on the calibration system to discrepancies in actual wind-tunnel data. The results from these case-studies will help aerodynamic researchers and force balance engineers to better the understand and identify potential differences in calibration systems due to coordinate system rotation and translation.

  10. Hydrodynamic modeling of the intrusion phenomenon in water distribution systems; Modelacion hidrodinamica del fenomeno de intrusion en tuberia de abastecimiento

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Jimenez, Petra Amparo; Mora-Rodriguez, Jose de Jesus; Perez-Garcia, Rafael; Martinez-Solano, F. Javier [Universidad Politecnica de Valencia (Spain)

    2008-10-15

    This paper describes a strategy for the hydrodynamic modeling of the pathogen intrusion phenomenon in water distribution systems by the combination of a breakage with a depression situation. This scenario will be modeled computationally and experimentally. The phenomenon to be represented by both simulations is the same: the entrance of an external volume into the circulation of a main volume, known as a pathogen intrusion, as long as the main volume is potable water. To this end, a prototype and a computational model based on Computational Fluid Dynamics (CFD) are used, which allow visualizing the fields of speeds and pressures in a simulated form. With the comparison of the results of both models, conclusions will be drawn on the detail of the studied pathogen intrusion phenomenon. [Spanish] En el presente documento se describe una estrategia de modelacion del fenomeno hidrodinamico de la intrusion patogena en redes de distribucion de agua por combinacion de una rotura con una situacion de depresion. Este escenario sera modelado computacional y experimentalmente. El fenomeno que se desea representar con ambas simulaciones es el mismo: la entrada de un caudal externo a una conduccion para la que circula un caudal principal, denominado intrusion patogena, siempre y cuando el caudal principal sea agua potable. Para ello se dispone de un prototipo y un modelo computacional basado en la Dinamica de Fluidos Computacional (DFC de aqui en adelante), que permite visualizar los campos de velocidades y presiones de forma simulada. Con la comparacion de los resultados de ambos modelos se extraeran conclusiones sobre el detalle del fenomeno de la intrusion patogena estudiado.

  11. Energy balance for steam generation system with biomass dryer

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Pedro A.R. [Instituto Superior Politecnico Jose Antonio Echeverria (CUJAE), Ciudad de La Habana (Cuba). Facultad Ingenieria Mecanica]. E-mail: pedro@economia.cujae.edu.cu; Lombardi, Geraldo; Santos, Antonio Moreira dos [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Escola de Engenharia]. E-mails: lombardi@sc.usp.br; asantos@sc.usp.br

    2008-07-01

    Water content is a major drainer of the energy available in the biomass, which justifies the proposal of a drying system with the potential to increase 80% of the biomass low heating value, also increasing the production of steam in the boiler and cogeneration of electricity. An example of biomass is the sugar cane bagasse of an alcohol mill producing 120,000 liters of alcohol per day, whose humidity from the extraction section is usually 50%. The present paper determines the increases in the mass flow rates of steam in the boiler, in the cogeneration of electricity and in the pay back time of the drying system and of the alcohol mill, as a consequence of the bagasse drying from 50 to 35%, considering 30% of air excess over the stoichiometric value admitted in the boiler for the bagasse burning. It also provides subsidies for the development and deployment of a drying system for the current boilers. (author)

  12. The Dutch corporate governance code and its monitoring: a balanced system?

    NARCIS (Netherlands)

    Hof, B.; Kerste, M.; Rosenboom, N.; Rougoor, W.; de Jong, A.

    2013-01-01

    The compliance of exchange-listed companies with the Dutch corporate governance code is generally high. This research takes three hypothetical changes to the current system as a starting point to investigate the question: is the Dutch system of regulating and monitoring corporate governance balanced

  13. Not as Easy as It Sounds: Designing a Balanced Assessment System

    Science.gov (United States)

    Chattergoon, Rajendra; Marion, Scott

    2016-01-01

    Many states and school districts are rethinking how they do educational assessment. A few are going further: attempting to build "balanced," "comprehensive," or "next-generation" assessment systems. At the same time, practitioners and researchers have long mulled the purposes and parts such systems should have. But…

  14. An energy-balancing perspective of interconnection and damping assignment control of nonlinear systems

    NARCIS (Netherlands)

    Jeltsema, Dimitri; Ortega, Romeo; Scherpen, Jacquelien M.A.

    2004-01-01

    Stabilization of nonlinear feedback passive systems is achieved assigning a storage function with a minimum at the desired equilibrium. For physical systems a natural candidate storage function is the difference between the stored and the supplied energies—leading to the so-called energy-balancing c

  15. Energy management based on AM/FM/GIS for phase balancing application on distribution systems

    Energy Technology Data Exchange (ETDEWEB)

    Kuo, C.-C., E-mail: cckuo@mail.sju.edu.t [Department of Electrical Engineering, Saint John' s University, 499, Sec. 4, TamKing Rd., Taipei, TamSui 25135, Taiwan (China); Chao, Y.-T., E-mail: bv2cr@yahoo.com.t [Department of Information Management, Technology and Science Institute of Northern Taiwan, 2, Xueyuan Rd., Peitou, Taipei 112, Taiwan (China)

    2010-03-15

    Unbalanced feeder systems may deteriorate of power quality, and increase investment and operating costs for distribution systems. The phase swapping method recommends re-phasing circuits of laterals and transformers for making the current and voltage balanced and also reducing feeder loss and voltage drop. In this paper, an application program, based on the automated mapping/facilities management/ geographic information system (AM/FM/GIS) is developed which contains a function of automatically computing Z-bus, load flow and phase balancing of feeders with phase swapping by using easily selecting of feeder on a graphic user interface application. Therefore, the relative data need not be keyed in manually. The presented phase balancing algorithm are based on database and related data structures developed on the AM/FM/GIS and Visual Basic software, which can be integrated into the Tai-Power distribution automation system. Then, the phase balancing algorithm is designed to handle the load patterns and the load of transformers that connect specific feeders when evaluating phase swaps that will result in reduced daily circuit losses over all load points. The proposed application not only can effectively reduce the circuit loss and improves phase balancing, but also enhances power quality efficiently under easily using environment.

  16. Interactive rehabilitation system for improvement of balance therapies in people with cerebral palsy.

    Science.gov (United States)

    Jaume-i-Capó, Antoni; Martínez-Bueso, Pau; Moyà-Alcover, Biel; Varona, Javier

    2014-03-01

    The present study covers a new experimental system, designed to improve the balance and postural control of adults with cerebral palsy. This system is based on a serious game for balance rehabilitation therapy, designed using the prototype development paradigm and features for rehabilitation with serious games: feedback, adaptability, motivational elements, and monitoring. In addition, the employed interaction technology is based on computer vision because motor rehabilitation consists of body movements that can be recorded, and because vision capture technology is noninvasive and can be used for clients who have difficulties in holding physical devices. Previous research has indicated that serious games help to motivate clients in therapy sessions; however, there remains a paucity of clinical evidence involving functionality. We rigorously evaluated the effects of physiotherapy treatment on balance and gait function of adult subjects with cerebral palsy undergoing our experimental system. A 24-week physiotherapy intervention program was conducted with nine adults from a cerebral palsy center who exercised weekly in 20-min sessions. Findings demonstrated a significant increase in balance and gait function scores resulting in indicators of greater independence for our participating adults. Scores improved from 16 to 21 points in a scale of 28, according to the Tinetti Scale for risk of falls, moving from high fall risk to moderate fall risk. Our promising results indicate that our experimental system is feasible for balance rehabilitation therapy.

  17. The functional assessment Berg Balance Scale is better capable of estimating fall risk in the elderly than the posturographic Balance Stability System.

    Science.gov (United States)

    Pereira, Vanessa Vieira; Maia, Roberto Alcantara; Silva, Sonia Maria Cesar de Azevedo

    2013-01-01

    The purpose of this study was to verify which instrument better identifies recurrent falls in the elderly. Ninety-eight old people, with an average age of 80 ± 4 years, were submitted to an assessment of balance and fall risk by means of the Berg Balance Scale (BBS) and the posturographic Balance Stability System (BSS). The BBS was correlated with the BSS (r=-0.27; p=0.008), age (r=-0.38; pbalance and demonstrated a greater capacity to identify falls risk suffered over the last year when compared with the BSS.

  18. Minimizing and balancing setups in a serial production system

    OpenAIRE

    Detti, Paolo; Pranzo, Marco; Meloni, Carlo

    2007-01-01

    Abstract This paper addresses a problem arising in the coordination between two consecutive manufacturing departments of a production system, in which parts are processed in batches, and each batch is characterized by two distinct attributes. Due to limited interstage buffering between the two stages, the two departments have to follow the same batch sequence. In the first department, a setup occurs every time the first attribute of the new batch is different f...

  19. Steam System Balancing and Tuning for Multifamily Residential Buildings in Chicagoland

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jayne [Partnership for Advanced Residential Retrofit (PARR), Chicago, IL (United States); Ludwig, Peter [Partnership for Advanced Residential Retrofit (PARR), Chicago, IL (United States); Brand, Larry [Partnership for Advanced Residential Retrofit (PARR), Chicago, IL (United States)

    2012-08-01

    Older heating systems often suffer from mis-investment--multiple contractors upgrading parts of systems in inadequate or inappropriate ways that reduce system functionality and efficiency--or from a lack of proper maintenance. This technical report addresses these barriers to information, contractor resources, and cost-savings. Building off of previous research, CNT Energy conducted a study to identify best practices for the methodology, typical costs, and energy savings associated with steam system balancing.

  20. Macrostatistical hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Brenner, H.

    1992-01-01

    During the course of these efforts we have been studying suspension of particles in Newtonian and non-Newtonian liquids, embodying a combination of analysis, experiments, and numerical simulations. Experiments primarily involved tracking small balls as they fall slowly through otherwise quiescent suspensions of neutrally buoyant particles. Detailed trajectories of the balls, obtained either with new experimental techniques or by numerical simulation, were statistically interpreted in terms of the mean settling velocity and the dispersion about the mean. We showed that falling-ball rheometry, using small balls relative to the suspended particles, could be a means of measuring the macroscopic zero-shear-rate viscosity without significantly disturbing the original microstructure; therefore, falling-ball rheometry can be a powerful tool for use in studying the effects of microstructures on the macroscopic properties of suspensions. We plan to extend this work to the study of more complex, structured fluids, and to use other tools (e.g., rolling-ball rheometry) to study boundary effects. We also propose to study flowing suspensions to obtain non-zero-shear-rate viscosities. The intent is to develop an understanding of the basic principles needed to treat generic multiphase flow problems, through a detailed study of model systems. 8 refs.

  1. Asymmetry-aware load balancing for parallel applications in single-ISA multi-core systems

    Institute of Scientific and Technical Information of China (English)

    EunsungKIM; Hyeonsang EOM; Heon Y. YEOM

    2012-01-01

    Contemporary operating systems for single-ISA (instruction set architecture) multi-core systems attempt to distribute tasks equally among all the CPUs.This approach works relatively well when there is no difference in CPU capability.However,there are cases in which CPU capability differs from one another.For instance,static capability asymmetry results from the advent of new asymmetric hardware,and dynamic capability asymmetry comes from the operating system (OS) outside noise caused from networking or I/O handling.These asymmetries can make it hard for the OS scheduler to evenly distribute the tasks,resulting in less efficient load balancing.In this paper,we propose a user-level load balancer for parallel applications,called the ‘capability balancer',which recognizes the difference of CPU capability and makes subtasks share the entire CPU capability fairly.The balancer can coexist with the existing kernel-level load balancer without detrimenting the behavior of the kernel balancer.The capability balancer can fairly distribute CPU capability to tasks with very little overhead.For real workloads like the NAS Parallel Benchmark (NPB),we have accomplished speedups of up to 9.8% and 8.5% in dynamic and static asymmetries,respectively.We have also experienced speedups of 13.3 % for dynamic asymmetry and 24.1% for static asymmetry in a competitive environment.The impacts of our task selection policies,FIFO (first in,first out) and cache,were compared.The use of the cache policy led to a speedup of 5.3% in overall execution time and a decrease of 4.7% in the overall cache miss count,compared with the FIFO policy,which is used by default.

  2. Numerical Estimation of Balanced and Falling States for Constrained Legged Systems

    Science.gov (United States)

    Mummolo, Carlotta; Mangialardi, Luigi; Kim, Joo H.

    2017-08-01

    Instability and risk of fall during standing and walking are common challenges for biped robots. While existing criteria from state-space dynamical systems approach or ground reference points are useful in some applications, complete system models and constraints have not been taken into account for prediction and indication of fall for general legged robots. In this study, a general numerical framework that estimates the balanced and falling states of legged systems is introduced. The overall approach is based on the integration of joint-space and Cartesian-space dynamics of a legged system model. The full-body constrained joint-space dynamics includes the contact forces and moments term due to current foot (or feet) support and another term due to altered contact configuration. According to the refined notions of balanced, falling, and fallen, the system parameters, physical constraints, and initial/final/boundary conditions for balancing are incorporated into constrained nonlinear optimization problems to solve for the velocity extrema (representing the maximum perturbation allowed to maintain balance without changing contacts) in the Cartesian space at each center-of-mass (COM) position within its workspace. The iterative algorithm constructs the stability boundary as a COM state-space partition between balanced and falling states. Inclusion in the resulting six-dimensional manifold is a necessary condition for a state of the given system to be balanced under the given contact configuration, while exclusion is a sufficient condition for falling. The framework is used to analyze the balance stability of example systems with various degrees of complexities. The manifold for a 1-degree-of-freedom (DOF) legged system is consistent with the experimental and simulation results in the existing studies for specific controller designs. The results for a 2-DOF system demonstrate the dependency of the COM state-space partition upon joint-space configuration (elbow-up vs

  3. Numerical Estimation of Balanced and Falling States for Constrained Legged Systems

    Science.gov (United States)

    Mummolo, Carlotta; Mangialardi, Luigi; Kim, Joo H.

    2017-01-01

    Instability and risk of fall during standing and walking are common challenges for biped robots. While existing criteria from state-space dynamical systems approach or ground reference points are useful in some applications, complete system models and constraints have not been taken into account for prediction and indication of fall for general legged robots. In this study, a general numerical framework that estimates the balanced and falling states of legged systems is introduced. The overall approach is based on the integration of joint-space and Cartesian-space dynamics of a legged system model. The full-body constrained joint-space dynamics includes the contact forces and moments term due to current foot (or feet) support and another term due to altered contact configuration. According to the refined notions of balanced, falling, and fallen, the system parameters, physical constraints, and initial/final/boundary conditions for balancing are incorporated into constrained nonlinear optimization problems to solve for the velocity extrema (representing the maximum perturbation allowed to maintain balance without changing contacts) in the Cartesian space at each center-of-mass (COM) position within its workspace. The iterative algorithm constructs the stability boundary as a COM state-space partition between balanced and falling states. Inclusion in the resulting six-dimensional manifold is a necessary condition for a state of the given system to be balanced under the given contact configuration, while exclusion is a sufficient condition for falling. The framework is used to analyze the balance stability of example systems with various degrees of complexities. The manifold for a 1-degree-of-freedom (DOF) legged system is consistent with the experimental and simulation results in the existing studies for specific controller designs. The results for a 2-DOF system demonstrate the dependency of the COM state-space partition upon joint-space configuration (elbow-up vs

  4. Dynamic balancing of dual-rotor system with very little rotating speed difference

    Institute of Scientific and Technical Information of China (English)

    杨健; 贺世正; 王乐勤

    2003-01-01

    Unbalanced vibration in dual-rotor rotating machinery was studied with numerical simulations and experiments. A new method is proposed to separate vibration signals of inner and outer rotors for a system with very little difference in rotating speeds. Magnitudes and phase values of unbalance defects can be obtained directly by sampling the vibration signal synchronized with reference signal. The balancing process is completed by the reciprocity influence coefficients of inner and outer rotors method. Results showed the advantage of such method for a dual-rotor system as compared with conventional balancing.

  5. Optimal reconfiguration and DG allocation in balanced and unbalanced distribution systems

    Directory of Open Access Journals (Sweden)

    Seyed Abbas Taher

    2014-09-01

    Full Text Available This paper investigates feeder reconfiguration in balanced and unbalanced networks and presents an efficient method to optimize practical distribution systems by means of simultaneous reconfiguration and distributed generation (DG allocation. A precise and robust load flow algorithm is applied and a composite multi-objective function is formulated to solve the problem which includes: 1. power loss saving, 2. voltage profile, 3. voltage unbalance, and 4. current unbalance of the system. The genetic algorithm (GA is utilized to search for optimal solution. Results show significant reduction in power loss and number of voltage violations. Moreover, in unbalanced cases, ability of proposed method in three-phase balancing is demonstrated.

  6. Load-Balance Policy in Two Level-Cluster File System

    Institute of Scientific and Technical Information of China (English)

    LIU Yuling; SONG Weiwei; MA Xiaoxue

    2006-01-01

    In this paper, we explored a load-balancing algorithm in a cluster file system contains two levels of metadata-server,primary-level server quickly distributestasks to second-level servers depending on the closest load-balancing information. At the same time, we explored a method which accurately reflect I/O traffic and storage of storage-node: computing the heat-value of file, according to which we realized a more logical storage allocation. According to the experiment result, we conclude that this new algorithm shortens the executing time of tasks and improves the system performance compared with other load algorithm.

  7. Anisotropic hydrodynamics: Motivation and methodology

    Energy Technology Data Exchange (ETDEWEB)

    Strickland, Michael

    2014-06-15

    In this proceedings contribution I review recent progress in our understanding of the bulk dynamics of relativistic systems that possess potentially large local rest frame momentum-space anisotropies. In order to deal with these momentum-space anisotropies, a reorganization of relativistic viscous hydrodynamics can be made around an anisotropic background, and the resulting dynamical framework has been dubbed “anisotropic hydrodynamics”. I also discuss expectations for the degree of momentum-space anisotropy of the quark–gluon plasma generated in relativistic heavy ion collisions at RHIC and LHC from second-order viscous hydrodynamics, strong-coupling approaches, and weak-coupling approaches.

  8. Quantum Plasmas An Hydrodynamic Approach

    CERN Document Server

    Haas, Fernando

    2011-01-01

    This book provides an overview of the basic concepts and new methods in the emerging scientific area known as quantum plasmas. In the near future, quantum effects in plasmas will be unavoidable, particularly in high density scenarios such as those in the next-generation intense laser-solid density plasma experiment or in compact astrophysics objects. Currently, plasmas are in the forefront of many intriguing questions around the transition from microscopic to macroscopic modeling of charged particle systems. Quantum Plasmas: an Hydrodynamic Approach is devoted to the quantum hydrodynamic model paradigm, which, unlike straight quantum kinetic theory, is much more amenable to investigate the nonlinear realm of quantum plasmas. The reader will have a step-by-step construction of the quantum hydrodynamic method applied to plasmas. The book is intended for specialists in classical plasma physics interested in methods of quantum plasma theory, as well as scientists interested in common aspects of two major areas of...

  9. Effects of balance training using a virtual-reality system in older fallers

    Directory of Open Access Journals (Sweden)

    Duque G

    2013-02-01

    Full Text Available Gustavo Duque,1,2 Derek Boersma,1 Griselda Loza-Diaz,2 Sanobar Hassan,1 Hamlet Suarez,3 Dario Geisinger,3 Pushpa Suriyaarachchi,1 Anita Sharma,1 Oddom Demontiero1,21Falls and Fractures Clinic, Department of Geriatric Medicine, Nepean Hospital, Penrith, NSW, Australia; 2Ageing Bone Research Program, Division of Geriatric Medicine, Sydney Medical School Nepean, The University of Sydney, Penrith, NSW, Australia; 3British Hospital, CLAEH School of Medicine, Montevideo, UruguayAbstract: Poor balance is considered a challenging risk factor for falls in older adults. Therefore, innovative interventions for balance improvement in this population are greatly needed. The aim of this study was to evaluate the effect of a new virtual-reality system (the Balance Rehabilitation Unit [BRU] on balance, falls, and fear of falling in a population of community-dwelling older subjects with a known history of falls. In this study, 60 community-dwelling older subjects were recruited after being diagnosed with poor balance at the Falls and Fractures Clinic, Nepean Hospital (Penrith, NSW, Australia. Subjects were randomly assigned to either the BRU-training or control groups. Both groups received the usual falls prevention care. The BRU-training group attended balance training (two sessions/week for 6 weeks using an established protocol. Change in balance parameters was assessed in the BRU-training group at the end of their 6-week training program. Both groups were assessed 9 months after their initial assessment (month 0. Adherence to the BRU-training program was 97%. Balance parameters were significantly improved in the BRU-training group (P < 0.01. This effect was also associated with a significant reduction in falls and lower levels of fear of falling (P < 0.01. Some components of balance that were improved by BRU training showed a decline after 9 months post-training. In conclusion, BRU training is an effective and well-accepted intervention to improve balance

  10. Craniomandibular System and Postural Balance after 3-Day Dry Immersion.

    Directory of Open Access Journals (Sweden)

    Loïc Treffel

    Full Text Available The objective of the study was to determine the influence of simulated microgravity by exposure to dry immersion on the craniomandibular system. Twelve healthy male volunteers participated in a 3-day dry immersion study. Before and immediately after exposure we measured maximal bite force using piezoresistive sensors. The mechanical properties of the jaw and cervical muscles were evaluated before, during, and after dry immersion using MyotonPRO. Because recent studies reported the effects of jaw motor activity on the postural stability of humans, stabilometric measurements of center of pressure were performed before and after dry immersion in two mandibular positions: rest position without jaw clenching, and intercuspidal position during voluntary teeth clenching. Results revealed no significant changes of maximal bite force after dry immersion. All postural parameters were significantly altered by dry immersion. There were however no significant differences in stabilometric data according to mandibular position. Moreover the masseter tonicity increased immediately after the end of dry immersion period. Dry immersion could be used as a valid model for studying the effects of microgravity on human subjects. However, 3 days appear insufficient in duration to evaluate the effects of weightlessness on maximal bite force. Our research suggests a link between postural disturbance after dry immersion and masseter tonicity.

  11. Measure Guideline. Steam System Balancing and Tuning for Multifamily Residential Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jayne [Partnership for Advanced Residential Retrofit (PARR), Chicago, IL (United States); Ludwig, Peter [Partnership for Advanced Residential Retrofit (PARR), Chicago, IL (United States); Brand, Larry [Partnership for Advanced Residential Retrofit (PARR), Chicago, IL (United States)

    2013-04-01

    This guideline provides building owners, professionals involved in multifamily audits, and contractors insights for improving the balance and tuning of steam systems. It provides readers an overview of one-pipe steam heating systems, guidelines for evaluating steam systems, typical costs and savings, and guidelines for ensuring quality installations. It also directs readers to additional resources for details not included here. Measures for balancing a distribution system that are covered include replacing main line vents and upgrading radiator vents. Also included is a discussion on upgrading boiler controls and the importance of tuning the settings on new or existing boiler controls. The guideline focuses on one-pipe steam systems, though many of the assessment methods can be generalized to two-pipe steam systems.

  12. Reliability of the good balance system(®) for postural sway measurement in poststroke patients.

    Science.gov (United States)

    Ha, Hyungeun; Cho, Kihun; Lee, Wanhee

    2014-01-01

    [Purpose] The purpose of this study was to examine test-retest reliability of the Good Balance system(®) for measurement of postural sway in poststroke patients. [Subjects] Sixty chronic stroke patients (40 men and 20 women; age 63.08 years; stroke duration 16.45 months) participated in this study. [Methods] Postural sway was evaluated using a force platform system (Good Balance system, Metitur Oy, Jyvaskyla, Finland). Two examiners measured postural sway for all participants during two separate testing sessions. The second measurement was performed one week after the first measurement. Intraclass correlation coefficients [ICC(2,1)] were used for estimation of reliability. [Results] The ICC (95% CI) for intra-examiner reliability was good to very good, ranging from 0.69 to 0.93 (0.53-0.96), and the ICC for inter-examiner reliability was good to very good, ranging from 0.85 to 0.98 (0.77-0.99). [Conclusion] The results of the current study indicated that the intra- and inter-examiner reliability of the Good Balance system(®) for measurement of postural sway was good to very good. Therefore, we suggest that measurement of postural sway using the Good Balance system(®) would be useful for clinical assessment in poststroke patients.

  13. Hydrodynamic Nambu Brackets derived by Geometric Constraints

    CERN Document Server

    Blender, Richard

    2015-01-01

    A geometric approach to derive the Nambu brackets for ideal two-dimensional (2D) hydrodynamics is suggested. The derivation is based on two-forms with vanishing integrals in a periodic domain, and with resulting dynamics constrained by an orthogonality condition. As a result, 2D hydrodynamics with vorticity as dynamic variable emerges as a generic model, with conservation laws which can be interpreted as enstrophy and energy functionals. Generalized forms like surface quasi-geostrophy and fractional Poisson equations for the stream-function are also included as results from the derivation. The formalism is extended to a hydrodynamic system coupled to a second degree of freedom, with the Rayleigh-B\\'{e}nard convection as an example. This system is reformulated in terms of constitutive conservation laws with two additive brackets which represent individual processes: a first representing inviscid 2D hydrodynamics, and a second representing the coupling between hydrodynamics and thermodynamics. The results can b...

  14. An equivalent unbalance identification method for the balancing of nonlinear squeeze-film damped rotordynamic systems

    Science.gov (United States)

    Torres Cedillo, Sergio G.; Bonello, Philip

    2016-01-01

    The high pressure (HP) rotor in an aero-engine assembly cannot be accessed under operational conditions because of the restricted space for instrumentation and high temperatures. This motivates the development of a non-invasive inverse problem approach for unbalance identification and balancing, requiring prior knowledge of the structure. Most such methods in the literature necessitate linear bearing models, making them unsuitable for aero-engine applications which use nonlinear squeeze-film damper (SFD) bearings. A previously proposed inverse method for nonlinear rotating systems was highly limited in its application (e.g. assumed circular centered SFD orbits). The methodology proposed in this paper overcomes such limitations. It uses the Receptance Harmonic Balance Method (RHBM) to generate the backward operator using measurements of the vibration at the engine casing, provided there is at least one linear connection between rotor and casing, apart from the nonlinear connections. A least-squares solution yields the equivalent unbalance distribution in prescribed planes of the rotor, which is consequently used to balance it. The method is validated on distinct rotordynamic systems using simulated casing vibration readings. The method is shown to provide effective balancing under hitherto unconsidered practical conditions. The repeatability of the method, as well as its robustness to noise, model uncertainty and balancing errors, are satisfactorily demonstrated and the limitations of the process discussed.

  15. Mass-balance Approach to Interpreting Weathering Reactions in Watershed Systems

    Science.gov (United States)

    Bricker, O. P.; Jones, B. F.; Bowser, C. J.

    2003-12-01

    The mass-balance approach is conceptually simple and has found widespread applications in many fields over the years. For example, chemists use mass balance (Stumm and Morgan, 1996) to sum the various species containing an element in order to determine the total amount of that element in the system (free ion, complexes). Glaciologists use mass balance to determine the changes in mass of glaciers ( Mayo et al., 1972 and references therein). Groundwater hydrologists use this method to interpret changes in water balance in groundwater systems ( Rasmussen and Andreasen, 1959; Bredehoeft et al., 1982; Heath, 1983; Konikow and Mercer, 1988; Freeze and Cherry, 1979; Ingebritsen and Sanford, 1998). This method has also been used to determine changes in chemistry along a flow path ( Plummer et al., 1983; Bowser and Jones, 1990) and to quantify lake hydrologic budgets using stable isotopes ( Krabbenhoft et al., 1994). Blum and Erel (see Chapter 5.12) discuss the use of strontium isotopes, Chapelle (see Chapter 5.14) treats carbon isotopes in groundwater, and Kendall and Doctor (see Chapter 5.11) and Kendall and McDonnell (1998) discuss the use of stable isotopes in mass balance. Although the method is conceptually simple, the parameters that define a mass balance are not always easy to measure. Watershed investigators use mass balance to determine physical and chemical changes in watersheds ( Garrels and Mackenzie, 1967; Plummer et al., 1991; O'Brien et al., 1997; Drever, 1997). Here we focus on describing the mass-balance approach to interpret weathering reactions in watershed systems including shallow groundwater.Because mass balance is simply an accounting of the flux of material into a system minus the flux of material out of the system, the geochemical mass-balance approach is well suited to interpreting weathering reactions in watersheds (catchments) and in other environmental settings (Drever, 1997). It is, perhaps, the most accurate and reliable way of defining

  16. Hydrodynamic effects on coalescence.

    Energy Technology Data Exchange (ETDEWEB)

    Dimiduk, Thomas G.; Bourdon, Christopher Jay; Grillet, Anne Mary; Baer, Thomas A.; de Boer, Maarten Pieter; Loewenberg, Michael (Yale University, New Haven, CT); Gorby, Allen D.; Brooks, Carlton, F.

    2006-10-01

    The goal of this project was to design, build and test novel diagnostics to probe the effect of hydrodynamic forces on coalescence dynamics. Our investigation focused on how a drop coalesces onto a flat surface which is analogous to two drops coalescing, but more amenable to precise experimental measurements. We designed and built a flow cell to create an axisymmetric compression flow which brings a drop onto a flat surface. A computer-controlled system manipulates the flow to steer the drop and maintain a symmetric flow. Particle image velocimetry was performed to confirm that the control system was delivering a well conditioned flow. To examine the dynamics of the coalescence, we implemented an interferometry capability to measure the drainage of the thin film between the drop and the surface during the coalescence process. A semi-automated analysis routine was developed which converts the dynamic interferogram series into drop shape evolution data.

  17. Reliability of System Identification Techniques to Assess Standing Balance in Healthy Elderly.

    Directory of Open Access Journals (Sweden)

    Jantsje H Pasma

    Full Text Available System identification techniques have the potential to assess the contribution of the underlying systems involved in standing balance by applying well-known disturbances. We investigated the reliability of standing balance parameters obtained with multivariate closed loop system identification techniques.In twelve healthy elderly balance tests were performed twice a day during three days. Body sway was measured during two minutes of standing with eyes closed and the Balance test Room (BalRoom was used to apply four disturbances simultaneously: two sensory disturbances, to the proprioceptive and the visual system, and two mechanical disturbances applied at the leg and trunk segment. Using system identification techniques, sensitivity functions of the sensory disturbances and the neuromuscular controller were estimated. Based on the generalizability theory (G theory, systematic errors and sources of variability were assessed using linear mixed models and reliability was assessed by computing indexes of dependability (ID, standard error of measurement (SEM and minimal detectable change (MDC.A systematic error was found between the first and second trial in the sensitivity functions. No systematic error was found in the neuromuscular controller and body sway. The reliability of 15 of 25 parameters and body sway were moderate to excellent when the results of two trials on three days were averaged. To reach an excellent reliability on one day in 7 out of 25 parameters, it was predicted that at least seven trials must be averaged.This study shows that system identification techniques are a promising method to assess the underlying systems involved in standing balance in elderly. However, most of the parameters do not appear to be reliable unless a large number of trials are collected across multiple days. To reach an excellent reliability in one third of the parameters, a training session for participants is needed and at least seven trials of two

  18. Reliability of System Identification Techniques to Assess Standing Balance in Healthy Elderly.

    Science.gov (United States)

    Pasma, Jantsje H; Engelhart, Denise; Maier, Andrea B; Aarts, Ronald G K M; van Gerven, Joop M A; Arendzen, J Hans; Schouten, Alfred C; Meskers, Carel G M; van der Kooij, Herman

    2016-01-01

    System identification techniques have the potential to assess the contribution of the underlying systems involved in standing balance by applying well-known disturbances. We investigated the reliability of standing balance parameters obtained with multivariate closed loop system identification techniques. In twelve healthy elderly balance tests were performed twice a day during three days. Body sway was measured during two minutes of standing with eyes closed and the Balance test Room (BalRoom) was used to apply four disturbances simultaneously: two sensory disturbances, to the proprioceptive and the visual system, and two mechanical disturbances applied at the leg and trunk segment. Using system identification techniques, sensitivity functions of the sensory disturbances and the neuromuscular controller were estimated. Based on the generalizability theory (G theory), systematic errors and sources of variability were assessed using linear mixed models and reliability was assessed by computing indexes of dependability (ID), standard error of measurement (SEM) and minimal detectable change (MDC). A systematic error was found between the first and second trial in the sensitivity functions. No systematic error was found in the neuromuscular controller and body sway. The reliability of 15 of 25 parameters and body sway were moderate to excellent when the results of two trials on three days were averaged. To reach an excellent reliability on one day in 7 out of 25 parameters, it was predicted that at least seven trials must be averaged. This study shows that system identification techniques are a promising method to assess the underlying systems involved in standing balance in elderly. However, most of the parameters do not appear to be reliable unless a large number of trials are collected across multiple days. To reach an excellent reliability in one third of the parameters, a training session for participants is needed and at least seven trials of two minutes must be

  19. Reforming the Health Care System for Children and the Elderly to Balance Cure and Care.

    Science.gov (United States)

    Callahan, Daniel

    1992-01-01

    Issues in balancing health services and costs in a changing society, where groups have differential access to health care, are discussed, including need for a universal health care system, growing cost of health care for the elderly, prolongation of life among older adults, and the claims of children on services. (MSE)

  20. Balanced Realization and Model Order Reduction for Nonlinear Systems based on Singular Value Analysis

    NARCIS (Netherlands)

    Fujimoto, Kenji; Scherpen, Jacquelien M. A.

    2010-01-01

    This paper discusses balanced realization and model order reduction for both continuous-time and discrete-time general nonlinear systems based on singular value analysis of the corresponding Hankel operators. Singular value analysis clarifies the gain structure of a given nonlinear operator. Here it

  1. A high performance GPU implementation of Surface Energy Balance System (SEBS) based on CUDA-C

    NARCIS (Netherlands)

    Abouali, Mohammad; Timmermans, J.; Castillo, Jose E.; Su, Zhongbo

    2013-01-01

    This paper introduces a new implementation of the Surface Energy Balance System (SEBS) algorithm harnessing the many cores available on Graphics Processing Units (GPUs). This new implementation uses Compute Unified Device Architecture C (CUDA-C) programming model and is designed to be executed on a

  2. Carrier Load Balancing and Packet Scheduling for Multi-Carrier Systems

    DEFF Research Database (Denmark)

    Wang, Yuanye; Pedersen, Klaus; Sørensen, Troels Bundgaard

    2010-01-01

    methods for allocating the CCs to the users- Round Robin (RR) and Mobile Hashing (MH) balancing by means of a simple theoretical formulation, as well as system level simulations. At Layer-2 we propose a simple cross-CC packet scheduling algorithm that improves the coverage performance and the resource...

  3. 26 CFR 801.1 - Balanced performance measurement system; in general.

    Science.gov (United States)

    2010-04-01

    ...: Customer Satisfaction Measures; Employee Satisfaction Measures; and Business Results Measures. The IRS is... 26 Internal Revenue 20 2010-04-01 2010-04-01 false Balanced performance measurement system; in general. 801.1 Section 801.1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE...

  4. A high performance GPU implementation of Surface Energy Balance System (SEBS) based on CUDA-C

    NARCIS (Netherlands)

    Abouali, Mohammad; Timmermans, Joris; Castillo, Jose E.; Su, Bob Z.

    2013-01-01

    This paper introduces a new implementation of the Surface Energy Balance System (SEBS) algorithm harnessing the many cores available on Graphics Processing Units (GPUs). This new implementation uses Compute Unified Device Architecture C (CUDA-C) programming model and is designed to be executed on a

  5. A Monolithic Double-balanced Upconverter for millimeter-wave Point-to-Multipoint Distribution Systems

    OpenAIRE

    Ang, K S; Robertson, I.D.

    2000-01-01

    The design and performance of a monolithic double-balanced upconverter for mm-wave point-to- multipoint distribution systems are presented. Individual building blocks including the LO /RF balun, IF balun,LO /RF power amplifier,and the double- balanced mixer are also fabricated and tested.The complete upconverter,measuring 3x3.2mm,upconverts the 3 -5GHz IF to 40.5 -43.5GHz band with 20 dBm output power.

  6. Space vector modulation strategy for neutral-point voltage balancing in three-level inverter systems

    DEFF Research Database (Denmark)

    Choi, Uimin; Lee, Kyo Beum

    2013-01-01

    This study proposes a space vector modulation (SVM) strategy to balance the neutral-point voltage of three-level inverter systems. The proposed method is implemented by combining conventional symmetric SVM with nearest three-vector (NTV) modulation. The conventional SVM is converted to NTV...... modulation by properly adding or subtracting a minimum gate-on time. In addition, using this method, the switching frequency is reduced and a decrease of switching loss would be yielded. The neutral-point voltage is balanced by the proposed SVM strategy without additional hardware or complex calculations...

  7. Elasto-hydrodynamic lubrication

    CERN Document Server

    Dowson, D; Hopkins, D W

    1977-01-01

    Elasto-Hydrodynamic Lubrication deals with the mechanism of elasto-hydrodynamic lubrication, that is, the lubrication regime in operation over the small areas where machine components are in nominal point or line contact. The lubrication of rigid contacts is discussed, along with the effects of high pressure on the lubricant and bounding solids. The governing equations for the solution of elasto-hydrodynamic problems are presented.Comprised of 13 chapters, this volume begins with an overview of elasto-hydrodynamic lubrication and representation of contacts by cylinders, followed by a discussio

  8. Elementary classical hydrodynamics

    CERN Document Server

    Chirgwin, B H; Langford, W J; Maxwell, E A; Plumpton, C

    1967-01-01

    Elementary Classical Hydrodynamics deals with the fundamental principles of elementary classical hydrodynamics, with emphasis on the mechanics of inviscid fluids. Topics covered by this book include direct use of the equations of hydrodynamics, potential flows, two-dimensional fluid motion, waves in liquids, and compressible flows. Some general theorems such as Bernoulli's equation are also considered. This book is comprised of six chapters and begins by introducing the reader to the fundamental principles of fluid hydrodynamics, with emphasis on ways of studying the motion of a fluid. Basic c

  9. The Surface Energy Balance System (SEBS for estimation of turbulent heat fluxes

    Directory of Open Access Journals (Sweden)

    Z. Su

    2002-01-01

    Full Text Available A Surface Energy Balance System (SEBS is proposed for the estimation of atmospheric turbulent fluxes and evaporative fraction using satellite earth observation data, in combination with meteorological information at proper scales. SEBS consists of: a set of tools for the determination of the land surface physical parameters, such as albedo, emissivity, temperature, vegetation coverage etc., from spectral reflectance and radiance measurements; a model for the determination of the roughness length for heat transfer; and a new formulation for the determination of the evaporative fraction on the basis of energy balance at limiting cases. Four experimental data sets are used to assess the reliabilities of SEBS. Based on these case studies, SEBS has proven to be capable to estimate turbulent heat fluxes and evaporative fraction at various scales with acceptable accuracy. The uncertainties in the estimated heat fluxes are comparable to in-situ measurement uncertainties. Keywords: Surface energy balance, turbulent heat flux, evaporation, remote sensing

  10. Evaluation of Advanced Control for Li-ion Battery Balancing Systems using Convex Optimization

    DEFF Research Database (Denmark)

    Pinto, Claudio; Barreras, Jorge Varela; Schaltz, Erik

    2016-01-01

    of energy losses, available capacity or temperature are obtained for the last three categories, even for moderate balancing currents. In particular, remarkable improvements are observed under conditions of high power demand with high variability, i.e., smaller battery sizes and more demanding driving cycles....... systems are evaluated in this paper by means of convex optimization. More than one hundred cases in a pure EV application are evaluated. Balancing circuits' efficiency models are implemented and realistic cell-to-cell parameter distributions are considered based on experimental data. Different battery...... sizes and driving cycles are considered. Balancing circuit topology is taken into account by selecting a specific category of energy transfer: cell-to-heat, bypass, cell-to-pack, pack-to-cell, cell-to-cell shared, cell-to-cell distributed or cell-to-pack-to-cell. In general, better results in terms...

  11. Effects of feed loading on nitrogen balances and fish performance in replicated recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Pedersen, Lars-Flemming; Suhr, Karin Isabel; Dalsgaard, Anne Johanne Tang

    2012-01-01

    /L at steady state, and the concentration of nitrogenous compounds and organic matter were all positively correlated to feed loading.The TAN loading to the RAS from the specific feed type was assessed in a separate mass-balance study and used as input in a descriptive mathematical model (AQUASIM® software......This study investigated the effects of applying four fixed feed loadings to three replicated recirculating aquaculture systems (RAS) on water quality changes, nitrogenous balances and growth performance of rainbow trout (Oncorhynchus mykiss).Feed loadings ranged from 1.6 to 6.3kgfeed/m3 make......) developed to simulate processes affecting N mass-balances in the RAS. Nitrification kinetic rate constants were applied to the biofilter, and fractions of nitrifiers in suspended solids in the water phase were estimated based on existing information from waste water treatment processes. Two model scenarios...

  12. Integration of microalgae systems at municipal wastewater treatment plants: implications for energy and emission balances.

    Science.gov (United States)

    Menger-Krug, Eve; Niederste-Hollenberg, Jutta; Hillenbrand, Thomas; Hiessl, Harald

    2012-11-06

    Integrating microalgae systems (MAS) at municipal wastewater treatment plants (WWTPs) to produce of bioenergy offers many potential synergies. Improved energy balances provide a strong incentive for WWTPs to integrate MAS, but it is crucial that WWTPs maintain their barrier function to protect water resources. We perform a prospective analysis of energy and emission balances of a WWTP with integrated MAS, based on a substance flow analysis of the elements carbon (C), nitrogen (N), and phosphorus (P). These elements are the main ingredients of wastewater, and the key nutrients for algae growth. We propose a process design which relies solely on resources from wastewater with no external input of water, fertilizer or CO(2). The whole process chain, from cultivation to production of bioelectricity, takes place at the WWTP. Our results show that MAS can considerably improve energy balances of WWTPs without any external resource input. With optimistic assumptions, they can turn WWTPs into net energy producers. While intensive C recycling in MAS considerably improves the energy balance, we show that it also impacts on effluent quality. We discuss the importance of nonharvested biomass for effluent quality and highlight harvesting efficiency as key factor for energy and emission balances of MAS at WWTP.

  13. Marketing residential grid-connected PV systems using a balanced scorecard as a marketing tool

    Energy Technology Data Exchange (ETDEWEB)

    Bach, N. [University of Giessen (Germany). Dept. of Organisation and Management; Calais, P. [Murdoch University, Perth (Australia). School of Environmental Science; Calais, M. [Curtin University, Perth (Australia). Centre for Renewable Systems Technology

    2001-03-01

    A strategic analysis of the electricity market in Western Australia yields a market potential for renewable energy in Western Australia. However, from a purely financial viewpoint the installation of grid-connected pv-systems still is not economically viable. In this paper a balanced scorecard (BSC) is developed to capture and visualize other than financial benefits. Therefore, the BSC can be used as a marketing tool to communicate the benefits of a privately owned GCPV system to potential customers. (author)

  14. Automatic balancing of AMB systems using plural notch filter and adaptive synchronous compensation

    Science.gov (United States)

    Xu, Xiangbo; Chen, Shao; Zhang, Yanan

    2016-07-01

    To achieve automatic balancing in active magnetic bearing (AMB) system, a control method with notch filters and synchronous compensators is widely employed. However, the control precision is significantly affected by the synchronous compensation error, which is caused by parameter errors and variations of the power amplifiers. Furthermore, the computation effort may become intolerable if a 4-degree-of-freedom (dof) AMB system is studied. To solve these problems, an adaptive automatic balancing control method in the AMB system is presented in this study. Firstly, a 4-dof radial AMB system is described and analyzed. To simplify the controller design, the 4-dof dynamic equations are transferred into two plural functions related to translation and rotation, respectively. Next, to achieve automatic balancing of the AMB system, two synchronous equations are formed. Solution of them leads to a control strategy based on notch filters and feedforward controllers with an inverse function of the power amplifier. The feedforward controllers can be simplified as synchronous phases and amplitudes. Then, a plural phase-shift notch filter which can identify the synchronous components in 2-dof motions is formulated, and an adaptive compensation method that can form two closed-loop systems to tune the synchronous amplitude of the feedforward controller and the phase of the plural notch filter is proposed. Finally, the proposed control strategy is verified by both simulations and experiments on a test rig of magnetically suspended control moment gyro. The results indicate that this method can fulfill the automatic balancing of the AMB system with a light computational load.

  15. Balancing the books – a statistical theory of prospective budgets in Earth System science

    Directory of Open Access Journals (Sweden)

    J. P. O'Kane

    2003-01-01

    Full Text Available An honest declaration of the error in a mass, momentum or energy balance, ε, simply raises the question of its acceptability: 'At what value of ε is the attempted balance to be rejected?' Answering this question requires a reference quantity against which to compare ε. This quantity must be a mathematical function of all the data used in making the balance. To deliver this function, a theory grounded in a workable definition of acceptability is essential. A distinction must be drawn between a retrospective balance and a prospective budget in relation to any natural space-filling body. Balances look to the past; budgets look to the future. The theory is built on the application of classical sampling theory to the measurement and closure of a prospective budget. It satisfies R.A. Fisher's 'vital requirement that the actual and physical conduct of experiments should govern the statistical procedure of their interpretation'. It provides a test, which rejects, or fails to reject, the hypothesis that the closing error on the budget, when realised, was due to sampling error only. By increasing the number of measurements, the discrimination of the test can be improved, controlling both the precision and accuracy of the budget and its components. The cost-effective design of such measurement campaigns is discussed briefly. This analysis may also show when campaigns to close a budget on a particular space-filling body are not worth the effort for either scientific or economic reasons. Other approaches, such as those based on stochastic processes, lack this finality, because they fail to distinguish between different types of error in the mismatch between a set of realisations of the process and the measured data. Keywords: balance, budget, sampling, hypothesis test, closing error, Earth System

  16. Reliability of the Balance Evaluation Systems Test (BESTest) and BESTest sections for adults with hemiparesis.

    Science.gov (United States)

    Rodrigues, Letícia C; Marques, Aline P; Barros, Paula B; Michaelsen, Stella M

    2014-01-01

    The Balance Evaluation Systems Test (BESTest) was recently created to allow the development of treatments according to the specific balance system affected in each patient. The Brazilian version of the BESTest has not been specifically tested after stroke. To evaluate the intra- and inter-rater reliability and concurrent and convergent validity of the total score of the BESTest and BESTest sections for adults with hemiparesis after stroke. The study included 16 subjects (61.1 ± 7.5 years) with chronic hemiparesis (54.5 ± 43.5 months after stroke). The BESTest was administered by two raters in the same week and one of the raters repeated the test after a one-week interval. Intraclass correlation coefficient (ICC) was calculated to assess intra- and interrater reliability. Concurrent validity with the Berg Balance Scale (BBS) and convergent validity with the Activities-specific Balance Confidence scale (ABC-Brazil) were assessed using Pearson's correlation coefficient. Both the BESTest total score (ICC=0.98) and the BESTest sections (ICC between 0.85 and 0.96) have excellent intrarater reliability. Interrater reliability for the total score was excellent (ICC=0.93) and, for the sections, it ranged between 0.71 and 0.94. The correlation coefficient between the BESTest and the BBS and ABC-Brazil were 0.78 and 0.59, respectively. The Brazilian version of the BESTest demonstrated adequate reliability when measured by sections and could identify what balance system was affected in patients after stroke. Concurrent validity was excellent with the BBS total score and good to excellent with the sections. The total scores but not the sections present adequate convergent validity with the ABC-Brazil. However, other psychometric properties should be further investigated.

  17. Reliability of the Balance Evaluation Systems Test (BESTest and BESTest sections for adults with hemiparesis

    Directory of Open Access Journals (Sweden)

    Letícia C. Rodrigues

    2014-07-01

    Full Text Available BACKGROUND: The Balance Evaluation Systems Test (BESTest was recently created to allow the development of treatments according to the specific balance system affected in each patient. The Brazilian version of the BESTest has not been specifically tested after stroke. OBJECTIVE: To evaluate the intra- and inter-rater reliability and concurrent and convergent validity of the total score of the BESTest and BESTest sections for adults with hemiparesis after stroke. METHOD: The study included 16 subjects (61.1±7.5 years with chronic hemiparesis (54.5±43.5 months after stroke. The BESTest was administered by two raters in the same week and one of the raters repeated the test after a one-week interval. Intraclass correlation coefficient (ICC was calculated to assess intra- and interrater reliability. Concurrent validity with the Berg Balance Scale (BBS and convergent validity with the Activities-specific Balance Confidence scale (ABC-Brazil were assessed using Pearson's correlation coefficient. RESULTS: Both the BESTest total score (ICC=0.98 and the BESTest sections (ICC between 0.85 and 0.96 have excellent intrarater reliability. Interrater reliability for the total score was excellent (ICC=0.93 and, for the sections, it ranged between 0.71 and 0.94. The correlation coefficient between the BESTest and the BBS and ABC-Brazil were 0.78 and 0.59, respectively. CONCLUSIONS: The Brazilian version of the BESTest demonstrated adequate reliability when measured by sections and could identify what balance system was affected in patients after stroke. Concurrent validity was excellent with the BBS total score and good to excellent with the sections. The total scores but not the sections present adequate convergent validity with the ABC-Brazil. However, other psychometric properties should be further investigated.

  18. Cell-balancing currents in parallel strings of a battery system

    Science.gov (United States)

    Dubarry, Matthieu; Devie, Arnaud; Liaw, Bor Yann

    2016-07-01

    Lithium-ion batteries are attractive for vehicle electrification or grid modernization applications. In these applications, battery packs are required to have multiple-cell configurations and battery management system to operate properly and safely. Here, a useful equivalent circuit model was developed to simulate the spontaneous transient balancing currents among parallel strings in a battery system. The simulation results were validated with experimental data to illustrate the accuracy and validity of the model predictions. Understanding the transient behavior of such cell and string balancing in a parallel circuit configuration is very important to assess the impacts of current fluctuation and cell variability on a battery system's performance, regarding durability, reliability, safety, abuse tolerance and failure prevention, including possible short circuit or open circuit conditions. Additional features and advantages, including the ability to assessing impacts on the performance of the string assemblies from string swapping or cell/module replacement in the strings, could be realized to aid battery management, maintenance and repair.

  19. New insights on the role of the endocannabinoid system in the regulation of energy balance.

    Science.gov (United States)

    Gatta-Cherifi, B; Cota, D

    2016-02-01

    Within the past 15 years, the endocannabinoid system (ECS) has emerged as a lipid signaling system critically involved in the regulation of energy balance, as it exerts a regulatory control on every aspect related to the search, the intake, the metabolism and the storage of calories. An overactive endocannabinoid cannabinoid type 1 (CB1) receptor signaling promotes the development of obesity, insulin resistance and dyslipidemia, representing a valuable pharmacotherapeutic target for obesity and metabolic disorders. However, because of the psychiatric side effects, the first generation of brain-penetrant CB1 receptor blockers developed as antiobesity treatment were removed from the European market in late 2008. Since then, recent studies have identified new mechanisms of action of the ECS in energy balance and metabolism, as well as novel ways of targeting the system that may be efficacious for the treatment of obesity and metabolic disorders. These aspects will be especially highlighted in this review.

  20. A particle-in-mesh method for Brownian Dynamics simulation of many-particle systems with hydrodynamics interactions in a confined geometry

    Science.gov (United States)

    Zhao, Xujun; Hernandez-Ortiz, Juan; Karpeyev, Dmitry; de Pablo, Juan; Smith, Barry

    In this work, we present an efficient parallel particle-in-mesh method for Brownian Dynamics simulations of many-particle systems confined in micro- and nano-fluidic devices. A general geometry Ewald-like method (GGEM) combined with finite element method is used to account for the hydrodynamic interaction. A fast parallel Krylov-type iterative solver with hybrid preconditioning techniques is developed for solving the large sparse systems of equations arising from finite element discretization of the Stokes equations. In addition, the current computer code is developed based on PETSc, a scalable library of numerical algorithms developed at Argonne, SLEPc - Scalable Library for Eigenvalue Problem Computations, and libMesh, a finite element library for numerical solution of PDEs built on top of PETSc, which allows for direct simulation of large scale systems with arbitrary confined geometries. This scheme is applied to Brownian dynamics simulations of flowing confined polymer solutions and colloidal dispersions in micro-fluid channels. The effects of hydrodynamics interactions and geometric confinement on the migration phenomena are illustrated.

  1. 76 FR 2368 - Balance Power Systems, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes...

    Science.gov (United States)

    2011-01-13

    ... Energy Regulatory Commission Balance Power Systems, LLC; Supplemental Notice That Initial Market-Based... supplemental notice in the above-referenced proceeding of Balance Power Systems, LLC's application for market... 20426. The filings in the above-referenced proceeding are accessible in the Commission's eLibrary...

  2. Quasiparticle anisotropic hydrodynamics

    CERN Document Server

    Alqahtani, Mubarak

    2016-01-01

    We study an azimuthally-symmetric boost-invariant quark-gluon plasma using quasiparticle anisotropic hydrodynamics including the effects of both shear and bulk viscosities. We compare results obtained using the quasiparticle method with the standard anisotropic hydrodynamics and viscous hydrodynamics. We consider the predictions of the three methods for the differential particle spectra and mean transverse momentum. We find that the three methods agree for small shear viscosity to entropy density ratio, $\\eta/s$, but show differences at large $\\eta/s$. Additionally, we find that the standard anisotropic hydrodynamics method shows suppressed production at low transverse-momentum compared to the other two methods, and the bulk-viscous correction can drive the primordial particle spectra negative at large $p_T$ in viscous hydrodynamics.

  3. Analysing chaos in fractional-order systems with the harmonic balance method

    Institute of Scientific and Technical Information of China (English)

    Wu Zheng-Mao; Lu Jun-Guo; Xie Jian-Ying

    2006-01-01

    In this paper, the fractional-order Genesio-Tesi system showing chaotic behaviours is introduced, and the corresponding one in an integer-order form is studied intensively. Based on the harmonic balance principle, which is widely used in the frequency analysis of nonlinear control systems, a theoretical approach is used to investigate the conditions of system parameters under which this fractional-order system can give rise to a chaotic attractor. Finally, the numerical simulation is used to verify the validity of the theoretical results.

  4. Chaos control and global synchronization of Liu chaotic systems using linear balanced feedback control

    Energy Technology Data Exchange (ETDEWEB)

    Chen, H.-H. [Department of Mechanical Engineering, HsiuPing Institute of Technology, Taichung 412, Taiwan (China)], E-mail: richard@mail.hit.edu.tw

    2009-04-15

    Liu chaotic systems exhibit two- or four-scroll attractors and are observed in a variety of engineering phenomena, including rigid body motion, brushless DC motor system and so forth. This study applies the Lyapunov stability theorem to identify the sufficient conditions for the asymptotic stability of the equilibrium points of Liu chaotic systems. A linear balanced feedback gain control method is then employed to design a controller to achieve the global synchronization of two identical four-scroll Liu chaotic systems. The feasibility and effectiveness of the proposed chaos stability and synchronization schemes are verified via numerical simulations.

  5. Dizziness and Balance

    Science.gov (United States)

    AUDIOLOGY Dizziness and Balance Inform ation Seri es Our balance system helps us walk, run, and move without falling. ... if I have a problem with balance or dizziness? It is important to see your doctor if ...

  6. Results of theoretical and experimental studies of hydrodynamics of circulation loops in circulating fluidized bed reactors and systems with interconnected reactors

    Science.gov (United States)

    Ryabov, G. A.; Folomeev, O. M.; Sankin, D. A.; Melnikov, D. A.

    2015-02-01

    Problems of the calculation of circulation loops in circulating fluidized bed reactors and systems with interconnected reactors (polygeneration systems for the production of electricity, heat, and useful products and chemical cycles of combustion and gasification of solid fuels)are considered. A method has been developed for the calculation of circulation loop of fuel particles with respect to boilers with circulating fluidized bed (CFB) and systems with interconnected reactors with fluidized bed (FB) and CFB. New dependences for the connection between the fluidizing agent flow (air, gas, and steam) and performance of reactors and for the whole system (solids flow rate, furnace and cyclone pressure drops, and bed level in the riser) are important elements of this method. Experimental studies of hydrodynamics of circulation loops on the aerodynamic unit have been conducted. Experimental values of pressure drop of the horizontal part of the L-valve, which satisfy the calculated dependence, have been obtained.

  7. A high resolution hydrodynamic model system suitable for novel harmful algal bloom modelling in areas of complex coastline and topography.

    Science.gov (United States)

    Aleynik, Dmitry; Dale, Andrew C; Porter, Marie; Davidson, Keith

    2016-03-01

    Fjordic coastlines provide sheltered locations for finfish and shellfish aquaculture, and are often subject to harmful algal blooms (HABs) some of which develop offshore and are then advected to impact nearshore aquaculture. Numerical models are a potentially important tool for providing early warning of such HAB events. However, the complex topography of fjordic shelf regions is a significant challenge to modelling. This is frequently compounded by complex bathymetry and local weather patterns. Existing structured grid models do not provide the resolution needed to represent these coastlines in their wider shelf context. In a number of locations advectively transported blooms of the ichthyotoxic dinoflagellate Karenia mikimotoi are of particular concern for the finfish industry. Here were present a novel hydrodynamic model of the coastal waters to the west of Scotland that is based on unstructured finite volume methodology, providing a sufficiently high resolution hydrodynamical structure to realistically simulate the transport of particles (such as K. mikimotoi cells) within nearshore waters where aquaculture sites are sited. Model-observation comparisons reveal close correspondence of tidal elevations for major semidiurnal and diurnal tidal constituents. The thermohaline structure of the model and its current fields are also in good agreement with a number of existing observational datasets. Simulations of the transport of Lagrangian drifting buoys, along with the incorporation of an individual-based biological model, based on a bloom of K. mikimotoi, demonstrate that unstructured grid models have considerable potential for HAB prediction in Scotland and in complex topographical regions elsewhere.

  8. A dynamic DFT approach to generalized diffusion equations in a system with long-ranged and hydrodynamic interactions

    Science.gov (United States)

    Bleibel, Johannes; Domínguez, Alvaro; Oettel, Martin

    2016-06-01

    We build on an existing approximation scheme to the Smoluchowski equation in order to derive a dynamic density functional theory (DDFT) including two-body hydrodynamic interactions. A generalized diffusion equation and a wavenumber-dependent diffusion coefficient D(k) are derived by linearization in the density fluctuations. The result is applied to a colloidal monolayer at a fluid interface, having bulk-like hydrodynamic interactions and/or interacting via long-ranged capillary forces. In these cases, D(k) shows characteristic singularities as k\\to 0 . The consequences of these singularities are studied by means of analytical perturbation theory, numerical solution of DDFT and simulations for an explicit example: the capillary collapse of a finite, disk-like distribution of particles. There is in general a good agreement between DDFT and simulations if the initial density distributions for the theoretical prediction correspond to the actual initial configurations of simulations, rather than to an average over them. Otherwise, discrepancies arise that are discussed in detail.

  9. Mizan: A system for dynamic load balancing in large-scale graph processing

    KAUST Repository

    Khayyat, Zuhair

    2013-01-01

    Pregel [23] was recently introduced as a scalable graph mining system that can provide significant performance improvements over traditional MapReduce implementations. Existing implementations focus primarily on graph partitioning as a preprocessing step to balance computation across compute nodes. In this paper, we examine the runtime characteristics of a Pregel system. We show that graph partitioning alone is insufficient for minimizing end-to-end computation. Especially where data is very large or the runtime behavior of the algorithm is unknown, an adaptive approach is needed. To this end, we introduce Mizan, a Pregel system that achieves efficient load balancing to better adapt to changes in computing needs. Unlike known implementations of Pregel, Mizan does not assume any a priori knowledge of the structure of the graph or behavior of the algorithm. Instead, it monitors the runtime characteristics of the system. Mizan then performs efficient fine-grained vertex migration to balance computation and communication. We have fully implemented Mizan; using extensive evaluation we show that - especially for highly-dynamic workloads - Mizan provides up to 84% improvement over techniques leveraging static graph pre-partitioning. © 2013 ACM.

  10. The implementation of PAYT system under the condition of financial balance in France.

    Science.gov (United States)

    Le Bozec, André

    2008-12-01

    Since 2005, France has been facing a reform of the financial regulation of the management of municipal solid waste, by tax or flat fees. Nevertheless, the application of unit pricing is limited to about 15 local authorities, but interest is expanding. The French examples confirm the efficiency of this PAYT system. The prevention and the sorting of packaging waste are increasing and the quantity of residual waste falling. But, we have highlighted the difficulty for the local authorities to balance their budgets during the years of PAYT system implementation. After a short review of the situation in France of the financing of waste services, and in particular of PAYT system, the paper presents, firstly the financial model and then, the results of its application in two communities. The cost model takes into account the expenditure of management on various waste flows and the revenues for the sale of by-products. A financial balance is ensured by the payments from households. Consequently, the unit pricing and the effect of the behaviour of the inhabitants are introduced into the simulation model. The application on two local authorities showed that the increase of sorting waste did not restore the balance. From the analysis, three reasons explain this situation: Thus, the development of the tariff must be carried out according to an economic approach. In the end, after the presentation of the financial modelling and its application, we make recommendations to aid the implementation of the PAYT system and the development of the pricing structures by local authorities.

  11. Population-based learning of load balancing policies for a distributed computer system

    Science.gov (United States)

    Mehra, Pankaj; Wah, Benjamin W.

    1993-01-01

    Effective load-balancing policies use dynamic resource information to schedule tasks in a distributed computer system. We present a novel method for automatically learning such policies. At each site in our system, we use a comparator neural network to predict the relative speedup of an incoming task using only the resource-utilization patterns obtained prior to the task's arrival. Outputs of these comparator networks are broadcast periodically over the distributed system, and the resource schedulers at each site use these values to determine the best site for executing an incoming task. The delays incurred in propagating workload information and tasks from one site to another, as well as the dynamic and unpredictable nature of workloads in multiprogrammed multiprocessors, may cause the workload pattern at the time of execution to differ from patterns prevailing at the times of load-index computation and decision making. Our load-balancing policy accommodates this uncertainty by using certain tunable parameters. We present a population-based machine-learning algorithm that adjusts these parameters in order to achieve high average speedups with respect to local execution. Our results show that our load-balancing policy, when combined with the comparator neural network for workload characterization, is effective in exploiting idle resources in a distributed computer system.

  12. Pegasus:a distributed and load-balancing fingerprint identification system*#

    Institute of Scientific and Technical Information of China (English)

    Yun-xiang ZHAO; Wan-xin ZHANG; Dong-sheng LI‡; Zhen HUANG; Min-ne LI; Xi-cheng LU

    2016-01-01

    Fingerprint has been widely used in a variety of biometric identifi cation systems in the past several years due to its uniqueness and immutability. With the rapid development of fi ngerprint identifi cation techniques, many fi ngerprint identifi cation systems are in urgent need to deal with large-scale fi ngerprint storage and high concurrent recognition queries, which bring huge challenges to the system. In this circumstance, we design and implement a distributed and load-balancing fi ngerprint identifi cation system named Pegasus, which includes a distributed feature extraction subsystem and a distributed feature storage subsystem. The feature extraction procedure combines the Hadoop Image Processing Interface (HIPI) library to enhance its overall processing speed; the feature storage subsystem optimizes MongoDB’s default load balance strategy to improve the efficiency and robustness of Pegasus. Experiments and simulations are carried out, and results show that Pegasus can reduce the time cost by 70%during the feature extraction procedure. Pegasus also balances the difference of access load among front-end mongos nodes to less than 5%. Additionally, Pegasus reduces over 40%of data migration among back-end data shards to obtain a more reasonable data distribution based on the operation load (insertion, deletion, update, and query) of each shard.

  13. Heat balance and eddies in the Peru-Chile current system

    Energy Technology Data Exchange (ETDEWEB)

    Colas, Francois; McWilliams, James C.; Kurian, Jaison [University of California, Institute of Geophysics and Planetary Physics, Los Angeles, CA (United States); Capet, Xavier [Laboratoire de Physique des Oceans, Ifremer, Plouzane (France)

    2012-07-15

    The Peru-Chile current System (PCS) is a region of persistent biases in global climate models. It has strong coastal upwelling, alongshore boundary currents, and mesoscale eddies. These oceanic phenomena provide essential heat transport to maintain a cool oceanic surface underneath the prevalent atmospheric stratus cloud deck, through a combination of mean circulation and eddy flux. We demonstrate these behaviors in a regional, quasi-equilibrium oceanic model that adequately resolves the mesoscale eddies with climatological forcing. The key result is that the atmospheric heating is large (>50 W m{sup -2}) over a substantial strip >500 km wide off the coast of Peru, and the balancing lateral oceanic flux is much larger than provided by the offshore Ekman flux alone. The atmospheric heating is weaker and the coastally influenced strip is narrower off Chile, but again the Ekman flux is not sufficient for heat balance. The eddy contribution to the oceanic flux is substantial. Analysis of eddy properties shows strong surface temperature fronts and associated large vorticity, especially off Peru. Cyclonic eddies moderately dominate the surface layer, and anticyclonic eddies, originating from the nearshore poleward Peru-Chile Undercurrent (PCUC), dominate the subsurface, especially off Chile. The sensitivity of the PCS heat balance to equatorial intra-seasonal oscillations is found to be small. We demonstrate that forcing the regional model with a representative, coarse-resolution global reanalysis wind product has dramatic and deleterious consequences for the oceanic circulation and climate heat balance, the eddy heat flux in particular. (orig.)

  14. Energy Storage System Based on Cascaded Multilevel Inverter with Decoupled Energy Balancing Control

    Directory of Open Access Journals (Sweden)

    Cao Yuanzhi

    2015-01-01

    Full Text Available This paper presents a three phase cascaded multilevel inverter based supercapacitor (SC energy storage system with novel structure and control strategy to maintain the energy balance of between phases. Every two phases are coupled with a series LC filter. With the filter, SC cells in different phases could exchange energy with an auxiliary power flow at high frequency. The auxiliary power flow is orthogonal to the primary power flow. The phase difference between high frequency voltage and current components of each phase determines whether the energy is absorbed into or released from its SC cells. Unlike traditional energy balancing strategies, the proposed method is independent to the fundamental real power drawn by the energy storage system. Simulation results confirmed the effects of proposed theories.

  15. Control Volume Analysis, Entropy Balance and the Entropy Production in Flow Systems

    OpenAIRE

    Niven, Robert K.; Noack, Bernd R.

    2014-01-01

    This chapter concerns "control volume analysis", the standard engineering tool for the analysis of flow systems, and its application to entropy balance calculations. Firstly, the principles of control volume analysis are enunciated and applied to flows of conserved quantities (e.g. mass, momentum, energy) through a control volume, giving integral (Reynolds transport theorem) and differential forms of the conservation equations. Several definitions of steady state are discussed. The concept of...

  16. Model Reduction via Time-Interval Balanced Stochastic Truncation for Linear Time Invariant Systems

    DEFF Research Database (Denmark)

    Tahavori, Maryamsadat; Shaker, Hamid Reza

    2013-01-01

    In this article, a new method for model reduction of linear dynamical systems is presented. The proposed technique is from the family of gramian-based relative error model reduction methods. The method uses time-interval gramians in the reduction procedure rather than ordinary gramians and in suc...... player example. The numerical results show that the method is more accurate than ordinary balanced stochastic truncation....

  17. Chaos control via TDFC in time-delayed systems: The harmonic balance approach

    Energy Technology Data Exchange (ETDEWEB)

    Vasegh, Nastaran [Faculty of Electrical Engineering, K.N. Toosi University of Technology, PO Box 16315-1355, Tehran (Iran, Islamic Republic of)], E-mail: vasegh@eetd.kntu.ac.ir; Khaki Sedigh, Ali [Faculty of Electrical Engineering, K.N. Toosi University of Technology, PO Box 16315-1355, Tehran (Iran, Islamic Republic of)

    2009-01-12

    This Letter deals with the problem of designing time-delayed feedback controllers (TDFCs) to stabilize unstable equilibrium points and periodic orbits for a class of continuous time-delayed chaotic systems. Harmonic balance approach is used to select the appropriate controller parameters: delay time and feedback gain. The established theoretical results are illustrated via a case study of the well-known Logistic model.

  18. A Balanced Approach to Capturing User Requirements in Business- to- Consumer Web Information Systems

    Directory of Open Access Journals (Sweden)

    M. S. Lane

    2001-11-01

    Full Text Available The development of business-to-consumer web information systems pose special challenges in the requirements analysis phase. It is difficult to capture user requirements given that users are relatively autonomous and anonymous and there are no major incentives for users to become involved in the development of a web information system. The researchers reviewed traditional requirement elicitation techniques, marketing research techniques and web usage analysis techniques. Current practice was assessed and the findings suggest that a balanced approach to user requirements capture will result in more complete and user centred requirements. This approach should lead to more effective business-to consumer web information systems.

  19. Coordinated Secondary Control for Balanced Discharge Rate of Energy Storage System in Islanded AC Microgrids

    DEFF Research Database (Denmark)

    Guan, Yajuan; Quintero, Juan Carlos Vasquez; Guerrero, Josep M.

    2016-01-01

    incidents and unintentional outages in DG units, but also aims to provide a fast transient response and an accurate output-current-sharing performance. A complete root locus analysis is given in order to achieve system stability and parameter sensitivity. Experimental results are presented to show......A coordinated secondary control approach based on an autonomous current-sharing control strategy for balancing the discharge rates of energy storage systems (ESSs) in islanded AC microgrids is proposed in this paper. The coordinated secondary controller can regulate the power outputs of distributed...... the performance of the whole system and to verify the effectiveness of the proposed controller....

  20. Performance Management through a Balanced Scorecard - A SystemsDynamics Modelling Approach

    DEFF Research Database (Denmark)

    Nielsen, Steen; Nielsen, Erland Hejn

    The object of this paper is to show how - normally separate practices - can be linked together to support the performance management system in a balanced scorecard framework. The monitor and learn of the strategy evaluation and the feedback process is important for the company to be on track....... Building mainly on [Kaplan, R. S. & Norton, D. P. (2008) 'Mastering the Management System, Harvard Business Review, January, 2008); Ferreira A. & Otley, D. (2005). The Design and Use of Management Control Systems: An Extended Framework for Analysis, Working Paper; and Sterman, J. D. (2000), Business...

  1. A compact wideband precision impedance measurement system based on digital auto-balancing bridge

    Science.gov (United States)

    Hu, Binxin; Wang, Jinyu; Song, Guangdong; Zhang, Faxiang

    2016-05-01

    The ac impedance spectroscopy measurements are predominantly taken by using impedance analyzers based on analog auto-balancing bridge. However, those bench-top analyzers are generally complicated, bulky and expensive, thus limiting their usage in industrial field applications. This paper presents the development of a compact wideband precision measurement system based on digital auto-balancing bridge. The methods of digital auto-balancing bridge and digital lock-in amplifier are analyzed theoretically. The overall design and several key sections including null detector, direct digital synthesizer-based sampling clock, and digital control unit are introduced in detail. The results show that the system achieves a basic measurement accuracy of 0.05% with a frequency range of 20 Hz-2 MHz. The advantages of versatile measurement capacity, fast measurement speed, small size and low cost make it quite suitable for industrial field applications. It is demonstrated that this system is practical and effective by applying in determining the impedance-temperature characteristic of a motor starter PTC thermistor.

  2. Tradeoffs in the design of health plan payment systems: Fit, power and balance.

    Science.gov (United States)

    Geruso, Michael; McGuire, Thomas G

    2016-05-01

    In many markets, including the new U.S. Marketplaces, health insurance plans are paid by risk-adjusted capitation, sometimes combined with reinsurance and other payment mechanisms. This paper proposes a framework for evaluating the de facto insurer incentives embedded in these complex payment systems. We discuss fit, power and balance, each of which addresses a distinct market failure in health insurance. We implement empirical metrics of fit, power, and balance in a study of Marketplace payment systems. Using data similar to that used to develop the Marketplace risk adjustment scheme, we quantify tradeoffs among the three classes of incentives. We show that an essential tradeoff arises between the goals of limiting costs and limiting cream skimming because risk adjustment, which is aimed at discouraging cream-skimming, weakens cost control incentives in practice. A simple reinsurance system scores better on our measures of fit, power and balance than the risk adjustment scheme in use in the Marketplaces. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Hydrodynamic interactions in two dimensions

    Science.gov (United States)

    di Leonardo, R.; Keen, S.; Ianni, F.; Leach, J.; Padgett, M. J.; Ruocco, G.

    2008-09-01

    We measure hydrodynamic interactions between colloidal particles confined in a thin sheet of fluid. The reduced dimensionality, compared to a bulk fluid, increases dramatically the range of couplings. Using optical tweezers we force a two body system along the eigenmodes of the mobility tensor and find that eigenmobilities change logarithmically with particle separation. At a hundred radii distance, the mobilities for rigid and relative motions differ by a factor of 2, whereas in bulk fluids, they would be practically indistinguishable. A two dimensional counterpart of Oseen hydrodynamic tensor quantitatively reproduces the observed behavior, once the relevant boundary conditions are recognized. These results highlight the importance of dimensionality for transport and interactions in colloidal systems and proteins in biological membranes.

  4. Algorithm refinement for fluctuating hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Sarah A.; Bell, John B.; Garcia, Alejandro L.

    2007-07-03

    This paper introduces an adaptive mesh and algorithmrefinement method for fluctuating hydrodynamics. This particle-continuumhybrid simulates the dynamics of a compressible fluid with thermalfluctuations. The particle algorithm is direct simulation Monte Carlo(DSMC), a molecular-level scheme based on the Boltzmann equation. Thecontinuum algorithm is based on the Landau-Lifshitz Navier-Stokes (LLNS)equations, which incorporate thermal fluctuations into macroscopichydrodynamics by using stochastic fluxes. It uses a recently-developedsolver for LLNS, based on third-order Runge-Kutta. We present numericaltests of systems in and out of equilibrium, including time-dependentsystems, and demonstrate dynamic adaptive refinement by the computationof a moving shock wave. Mean system behavior and second moment statisticsof our simulations match theoretical values and benchmarks well. We findthat particular attention should be paid to the spectrum of the flux atthe interface between the particle and continuum methods, specificallyfor the non-hydrodynamic (kinetic) time scales.

  5. Voltage Balancing Method on Expert System for 51-Level MMC in High Voltage Direct Current Transmission

    Directory of Open Access Journals (Sweden)

    Yong Chen

    2016-01-01

    Full Text Available The Modular Multilevel Converters (MMC have been a spotlight for the high voltage and high power transmission systems. In the VSC-HVDC (High Voltage Direct Current based on Voltage Source Converter transmission system, the energy of DC link is stored in the distributed capacitors, and the difference of capacitors in parameters and charge rates causes capacitor voltage balance which affects the safety and stability of HVDC system. A method of MMC based on the expert system for reducing the frequency of the submodules (SMs of the IGBT switching frequency is proposed. Firstly, MMC with 51 levels for HVDC is designed. Secondly, the nearest level control (NLC for 51-level MMC is introduced. Thirdly, a modified capacitor voltage balancing method based on expert system for MMC-based HVDC transmission system is proposed. Finally, a simulation platform for 51-level Modular Multilevel Converter is constructed by using MATLAB/SIMULINK. The results indicate that the strategy proposed reduces the switching frequency on the premise of keeping submodule voltage basically identical, which greatly reduces the power losses for MMC-HVDC system.

  6. Influence of the nonlinear phase and ASE noise on DPSK balanced optical receiver in optical fiber communication system

    Institute of Scientific and Technical Information of China (English)

    李蔚; 梅君瑶; 韩庆生; 王腾

    2009-01-01

    The analytical expression of bit error probability in a balanced differential phase-shift keying(DPSK) optical receiver considering nonlinear phase noise and EDFA ASE noise is given,which is very useful to estimate the performance of DPSK balanced and unbalanced receiver in optical communication system.Through analysis,if only nonlinear phase noise is considered,both the balance and unbalanced receivers have the same performances.But if adding the ASE noise of EDFA,the balanced receiver is better.

  7. Balancing device

    NARCIS (Netherlands)

    Van Dorsser, W.D.; Herder, J.L.; Wisse B.M.; Barents, R.

    2007-01-01

    The invention relates to a balancing device for a mass, comprising an arm that is adjustable about a pivoting point and with which the mass is coupled, and an adjustable spring system that is coupled with the arm, which spring system comprises at least one spring, wherein the spring system comprises

  8. Lithium-Ion Battery Cell-Balancing Algorithm for Battery Management System Based on Real-Time Outlier Detection

    Directory of Open Access Journals (Sweden)

    Changhao Piao

    2015-01-01

    Full Text Available A novel cell-balancing algorithm which was used for cell balancing of battery management system (BMS was proposed in this paper. Cell balancing algorithm is a key technology for lithium-ion battery pack in the electric vehicle field. The distance-based outlier detection algorithm adopted two characteristic parameters (voltage and state of charge to calculate each cell’s abnormal value and then identified the unbalanced cells. The abnormal and normal type of battery cells were acquired by online clustering strategy and bleeding circuits (R = 33 ohm were used to balance the abnormal cells. The simulation results showed that with the proposed balancing algorithm, the usable capacity of the battery pack increased by 0.614 Ah (9.5% compared to that without balancing.

  9. Linking Economic Value Added, Direct Costing, and the Lean Thinking to the Balanced Scorecard in a System Dynamics Modelling Approach

    DEFF Research Database (Denmark)

    Nielsen, Steen; Nielsen, Erland Hejn

     Purpose - To show how three practices normally applied separately can be linked to support the strategy evaluation and the performance measurement in the balanced scorecard. Recent studies, e.g. Kaplan and Norton [Using the Balanced Scorecard as a Strategic Management System, Harvard Business Re...

  10. Advanced Modular "All in One" Battery System with Intelligent Autonomous Cell Balancing Management

    Science.gov (United States)

    Petitdidier, X.; Pasquier, E.; Defer, M.; Koch, M.; Knorr, W.

    2008-09-01

    A new generation of energy storage systems based on Li-ion technology emerged at the end of the last century.To perform the first tests in safe conditions, Saft designed a simple electronic.Today, all Li-ion batteries for autonomous applications such as drones, launchers, missiles, torpedoes and "human" applications such as cellular, laptop, hybrid vehicle and nearly sub-marines need a Battery Management System.The minimum in terms of functions is the overcharge and over-discharge protections.For a battery made of 2 cells connected in series or more, a balancing system is added to maintain the available energy during all the life of the battery. For stringent/demanding applications, the state of charge and state of health are calculated by one or more computers.It is now time to take benefit of the past 10 years of Saft's experience in the domain to re-evaluate the constraints of Li-ion batteries and provide customers with improved products by optimizing the battery management.Benefits of electronic for satellite applications:• Full control over battery.• Confidence whatever the possible change of conditions in environment.• The battery system can resist long exposure to gradient conditions with mitigated and stabilized impact on performances.• The balancing function allow to use all the energy of all the cells: optimize of installed energy (compact design, mass saving). It started out with the basic fact that electrochemists are not intended to be space rated electronic experts and vice versa, even if Saft has a good heritage in the electronic battery management system. Consequently, considering heritage and expertise in their respective core businesses, Saft and ASP teamed up.It became necessary to provide an "all in one" modular energy storage system with intelligent autonomous cell balancing management.

  11. Testing, adjusting and balancing for air distribution and hydronic circulation system of RIPF

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seon Duk; Bang, H. S

    2003-01-01

    This report is to perform T.A.B(Testing, Adjusting, and Balancing) for area of 7000 and 8000 zone in RIPF Building. According to code, standard and specification, T.A.B of air distribution and hydronic system are carried out and only written a general items. Owing to today's demanding the retrenchment in the energy, It is important that we perform our duties to test, adjust and balance air handle unit objectively and independently. Therefore, though the scientific and reasonable verification procedure, we must try to not only admit T.A.B. techniques which present societies demand, but also secure advanced technologies by means of accelerating the related techniques.

  12. Bosonization and quantum hydrodynamics

    Indian Academy of Sciences (India)

    Girish S Setlur

    2006-03-01

    It is shown that it is possible to bosonize fermions in any number of dimensions using the hydrodynamic variables, namely the velocity potential and density. The slow part of the Fermi field is defined irrespective of dimensionality and the commutators of this field with currents and densities are exponentiated using the velocity potential as conjugate to the density. An action in terms of these canonical bosonic variables is proposed that reproduces the correct current and density correlations. This formalism in one dimension is shown to be equivalent to the Tomonaga-Luttinger approach as it leads to the same propagator and exponents. We compute the one-particle properties of a spinless homogeneous Fermi system in two spatial dimensions with long-range gauge interactions and highlight the metal-insulator transition in the system. A general formula for the generating function of density correlations is derived that is valid beyond the random phase approximation. Finally, we write down a formula for the annihilation operator in momentum space directly in terms of number conserving products of Fermi fields.

  13. Center of Gravity Compensation for Dynamically-Balanced Two-Wheeled Wheelchair System

    Science.gov (United States)

    Acar, Cihan; Murakami, Toshiyuki

    Two-wheeled systems have many advantages compared to statically stable systems. This paper describes a control strategy of dynamically-balanced two-wheeled wheelchair system that does not have any front casters. In this system, rider can sit the seat and control the motion of the system by adjusting CoG of his/her body. Unlike other commercial two-wheeled systems, CoG position of the upper body is mainly determined by the position of the user. Thus, there is a possibility that CoG position may not overlap with the wheel axis. In that case, sensor information cannot be used to measure the exact position of the CoG. This paper shows an estimation of method of the unknown CoG position for Two-Wheeled Dynamically-Balanced Wheelchair (TWDBW) is considered. Gravity torque observer with a compliance control is utilized to realize stable compensation according to the variable CoG position. Backstepping based nonlinear control design is applied to regulate and track the CoG motion of the upper body in the TWDBW. The validity of proposed method is verified by simulation and experimental results.

  14. Fuzzy coordinator compensation for balancing control of cart-seesaw system

    Science.gov (United States)

    Lin, J.; Guo, S.-Y.; Chang, Julian

    2011-12-01

    In contrast with fully controllable systems, a super articulated mechanical system (SAMS) is a controlled underactuated mechanical system in which the dimensions of the configuration space exceed the dimensions of the control input space. The control of the cart-seesaw system is especially difficult since it is an underactuated mechanism (three degrees of freedom and only two inputs). This research develops a balancing approach for a novel SAMS model, called the cart-seesaw system, using fuzzy logic and fuzzy coordinator compensation to drive the sliding carts and keep the seesaw angle close to zero in the equilibrium state. Experimental results indicate that utilizing the proposed control methodology significantly enhances the performance. Moreover, the presentation of the fuzzy balancing controller is not considerably affected by changes in the environmental parameters, which demonstrates the effectiveness of the fuzzy controller in minimizing the seesaw tilt angle in the time domain, although the system is caused by unpredicted loading variation. Moreover, the experimental results indicate the usefulness and robustness of the proposed fuzzy control methodology. Furthermore, the proposed software/hardware platform can be beneficial for standardizing laboratory equipment and developing amusement apparatus.

  15. Dynamic and balanced capacity allocation scheme with uniform bandwidth for OFDM-PON systems

    Science.gov (United States)

    Lei, Cheng; Chen, Hongwei; Chen, Minghua; Yu, Ying; Guo, Qiang; Yang, Sigang; Xie, Shizhong

    2015-03-01

    As the bitrate of orthogonal frequency division multiplexing passive optical network (OFDM-PON) system is continuously increasing, how to effectively allocate the system bandwidth among the huge number of optical network units (ONUs) is one of the key problems before OFDM-PON can be practical deployed. Unlike traditional bandwidth allocation scheme, in this paper, the transmission performance of single ONU is for the first time taken into consideration and optimized. To reduce the manufacturing complexity and fully utilize the processing ability of the receivers, the system bandwidth is equally distributed to the ONUs. Bit loading is used to allocate the total transmission capacity, and power loading is used to guarantee the ONUs have balanced transmission performance even if they operate at different bitrate. In this way, a dynamic and balanced capacity allocation scheme with uniform bandwidth for OFDM-PON systems can be realized. At last, an experimental system is established to verify the feasibility of the proposed scheme, and the influence that the scheme brings to the whole system is also analyzed.

  16. System of Thermal Balance Maintenance in Modern Test Benches for Centrifugal Pumps

    Directory of Open Access Journals (Sweden)

    A. I. Petrov

    2015-01-01

    Full Text Available The article “Systems of the heat balance maintenance in modern test benches for centrifugal pumps” makes the case to include cooling systems of a working fluid (heat setting in test bench for impeller pumps. It briefly summarizes an experience of bench building to test centrifugal pumps, developed at the BMSTU Department E-10 over the last 10 years. The article gives the formulas and the algorithm to calculate the heat capacity of different types of impeller pumps when tested at the bench as ell as to determine the heating time of the liquid in the bench without external cooling. Based on analysis of the power balance of a centrifugal pump, it is shown that about 90% of the pump unit-consumed electric power in terminals is used for heating up the working fluid in the loop of the test bench. The article gives examples of elementary heat calculation of the pump operation within the test bench. It presents the main types of systems to maintain thermal balance, their advantages, disadvantages and possible applications. The cooling system schemes for open and closed version of the benches both with built-in and with an independent cooling circuit are analysed. The paper separately considers options of such systems for large benches using the cooling tower as a cooling device in the loop, and to test the pumps using the hydraulic fluids other than water, including those at high temperatures of working fluids; in the latter case a diagram of dual-circuit cooling system "liquid-liquid-air" is shown. The paper depicts a necessity to use ethylene glycol coolant in the two-loop cooling bench. It provides an example of combining the functions of cooling and filtration in a single cooling circuit. Criteria for effectiveness of these systems are stated. Possible ways for developing systems to maintain a thermal balance, modern methods of regulation and control are described. In particular, the paper shows the efficiency of frequency control of the

  17. Constructing an Efficient and Balanced European Patent System: “Muddling through”

    DEFF Research Database (Denmark)

    Schovsbo, Jens Hemmingsen

    2011-01-01

    The paper discusses ways to construct a more efficient and balanced European patent system. It identifies and describes challenges relating to innovation, to non-economic issues and to governance. In order to improve the patent system, a cautious approach of “Muddling through” is recommended. More...... concretely, the paper puts forward some of the solutions proposed in the STOA Report to the European Parliament on “Policy options for the improvement of the European patent system” and suggest initiatives such as the insertion of a mission statement in the EPC, improvement of patent quality, increasing...... access to patented inventions and enhancement of governance....

  18. Discussing Feedback System Thinking in Relation to a Balanced Scorecard, Inspired by an Actual Case

    DEFF Research Database (Denmark)

    Nielsen, Steen; Nielsen, Erland Hejn

    Since the emergence of the Balanced Scorecard at the beginning of the 1990s, only few articles have proposed a framework of translating BSC into an analytical numerical model. This paper addresses two research themes : (1) a discussion of the cause-and-effect modeling within the BSC and (2), how...... may the feedback systems thinking and causal loop reasoning be conducted within BSC. In contrast to previous literature on BSC this paper focuses on a System Dynamics Modeling approach to transform a static BSC into a dynamic and analytical closed loop management model by incorporating both time...

  19. Hydrodynamics and black holes

    CERN Document Server

    Oz, Yaron

    2015-01-01

    This chapter describes how the AdS/CFT correspondence (the Holographic Principle) relates field theory hydrodynamics to perturbations of black hole (brane) gravitational backgrounds. The hydrodynamics framework is first presented from the field theory point of view, after which the dual gravitational description is outlined, first for relativistic fluids and then for the nonrelativistic case. Further details of the fluid/gravity correspondence are then discussed, including the bulk geometry and the dynamics of the black hole horizon.

  20. Recent progress in anisotropic hydrodynamics

    Directory of Open Access Journals (Sweden)

    Strickland Michael

    2017-01-01

    Full Text Available The quark-gluon plasma created in a relativistic heavy-ion collisions possesses a sizable pressure anisotropy in the local rest frame at very early times after the initial nuclear impact and this anisotropy only slowly relaxes as the system evolves. In a kinetic theory picture, this translates into the existence of sizable momentum-space anisotropies in the underlying partonic distribution functions, 〈 pL2〉 ≪ 〈 pT2〉. In such cases, it is better to reorganize the hydrodynamical expansion by taking into account momentum-space anisotropies at leading-order in the expansion instead of as a perturbative correction to an isotropic distribution. The resulting anisotropic hydrodynamics framework has been shown to more accurately describe the dynamics of rapidly expanding systems such as the quark-gluon plasma. In this proceedings contribution, I review the basic ideas of anisotropic hydrodynamics, recent progress, and present a few preliminary phenomenological predictions for identified particle spectra and elliptic flow.

  1. Regional Balance Model of Financial Flows through Sectoral Approaches System of National Accounts

    Directory of Open Access Journals (Sweden)

    Ekaterina Aleksandrovna Zaharchuk

    2017-03-01

    Full Text Available The main purpose of the study, the results of which are reflected in this article, is the theoretical and methodological substantiation of possibilities to build a regional balance model of financial flows consistent with the principles of the construction of the System of National Accounts (SNA. The paper summarizes the international experience of building regional accounts in the SNA as well as reflects the advantages and disadvantages of the existing techniques for constructing Social Accounting Matrix. The authors have proposed an approach to build the regional balance model of financial flows, which is based on the disaggregated tables of the formation, distribution and use of the added value of territory in the framework of institutional sectors of SNA (corporations, public administration, households. Within the problem resolution of the transition of value added from industries to sectors, the authors have offered an approach to the accounting of development, distribution and use of value added within the institutional sectors of the territories. The methods of calculation are based on the publicly available information base of statistics agencies and federal services. The authors provide the scheme of the interrelations of the indicators of the regional balance model of financial flows. It allows to coordinate mutually the movement of regional resources by the sectors of «corporation», «public administration» and «households» among themselves, and cash flows of the region — by the sectors and directions of use. As a result, they form a single account of the formation and distribution of territorial financial resources, which is a regional balance model of financial flows. This matrix shows the distribution of financial resources by income sources and sectors, where the components of the formation (compensation, taxes and gross profit, distribution (transfers and payments and use (final consumption, accumulation of value added are

  2. Estimation of Optimum Stimulus Amplitude for Balance Training using Electrical Stimulation of the Vestibular System

    Science.gov (United States)

    Goel, R.; Rosenberg, M. J.; De Dios, Y. E.; Cohen, H. S.; Bloomberg, J. J.; Mulavara, A. P.

    2016-01-01

    Sensorimotor changes such as posture and gait instabilities can affect the functional performance of astronauts after gravitational transitions. Sensorimotor Adaptability (SA) training can help alleviate decrements on exposure to novel sensorimotor environments based on the concept of 'learning to learn' by exposure to varying sensory challenges during posture and locomotion tasks (Bloomberg 2015). Supra-threshold Stochastic Vestibular Stimulation (SVS) can be used to provide one of many challenges by disrupting vestibular inputs. In this scenario, the central nervous system can be trained to utilize veridical information from other sensory inputs, such as vision and somatosensory inputs, for posture and locomotion control. The minimum amplitude of SVS to simulate the effect of deterioration in vestibular inputs for preflight training or for evaluating vestibular contribution in functional tests in general, however, has not yet been identified. Few studies (MacDougall 2006; Dilda 2014) have used arbitrary but fixed maximum current amplitudes from 3 to 5 mA in the medio-lateral (ML) direction to disrupt balance function in healthy adults. Giving this high level of current amplitude to all the individuals has a risk of invoking side effects such as nausea and discomfort. The goal of this study was to determine the minimum SVS level that yields an equivalently degraded balance performance. Thirteen subjects stood on a compliant foam surface with their eyes closed and were instructed to maintain a stable upright stance. Measures of stability of the head, trunk, and whole body were quantified in the ML direction. Duration of time they could stand on the foam surface was also measured. The minimum SVS dosage was defined to be that level which significantly degraded balance performance such that any further increase in stimulation level did not lead to further balance degradation. The minimum SVS level was determined by performing linear fits on the performance variable

  3. Numerical modeling of tides in the Great Bay Estuarine System: dynamical balance and spring-neap residual modulation

    Science.gov (United States)

    McLaughlin, J. W.; Bilgili, A.; Lynch, D. R.

    2003-05-01

    The Great Bay Estuarine System, in New Hampshire, USA, has been the focus area for an attempt to develop a robust finite element method model for estuarine hydrodynamics. Past studies used a nonlinear, time stepping, kinematic model with limited success (Ip et al. Advances in fluid mechanics III, WIT, Southampton (2000) 569; Bilgili et al. J. Geophys. Res. - Oceans 107 (2002); Ertürk et al. Estuar. Coast. Shelf Sci. 47 (1998) 119). We add dynamic physics (that is, local accelerations) for deep-water areas and keep kinematic physics (that is, without local and advective accelerations), with the inclusion of a porous medium beneath the open channel, for shallow and dewatering areas. The choice of which physics set to apply is made on an elemental depth dependent basis. The addition of the local acceleration terms for deep-water areas is seen to greatly improve accuracy in matching of tidal phasing over previous studies. Simulations involving M 2/M 4/M 6 tidal constituents result in strong agreement to observed data from the 1975 Great Bay field program (Swift & Brown, Estuar. Coast. Shelf Sci. 17 (1983) 297), in terms of both tidal heights and cross-section averaged velocities. Comparisons with 10 tidal elevation observation stations and four cross-section averaged current transects show good agreement, displaying average normalized root mean square misfit values of 0.08 and 0.25, respectively. Study of the simulated momentum balance shows the size of the contributions from acceleration terms to be on the order of a third the size of the contributions from the pressure gradient and bottom stress terms. Although relatively small, they are observed to peak at the crucial time of tidal reversal. Application of the model for long-term simulation using an M 2/N 2/S 2 forcing shows the ability to realistically capture the spring-neap cycle. The tidally rectified flow is generally described as a constant spatial pattern with overall amplitude modulation following the

  4. Impact of electromagnetic fields on human vestibular system and standing balance: pilot results and future developments

    Science.gov (United States)

    Allen, A.; Villard, S.; Corbacio, M.; Goulet, D.; Plante, M.; Souques, M.; Deschamps, F.; Ostiguy, G.; Lambrozo, J.; Thomas, A. W.; Legros, A.

    2016-03-01

    Although studies have found that extremely low-frequency (ELF, fields (MF) can modulate human standing balance, the acute effects of electromagnetic fields on standing balance have not been systematically investigated. This work aims to establish the threshold for acute standing balance modulation during ELFMF exposure. One hundred volunteers will be exposed to transcranial electric stimulations (Direct Current - DC and Alternating Current - AC, 1 mA) and ELFMF (0 to 160 Hz, 0 to 100 mT). The displacement of their center of pressure will be collected and analyzed as an indicator of vestibular performance. During pilot testing (n=6), we found increased lateral sway with DC, and to a lesser extent, AC exposure. The ELFMF exposure system still needs to be adapted to allow meaningful results. Future protocol design will test for possible effects due to exposures in the radiofrequency range (i.e. above 3 kHz). These results will contribute to the literature documenting exposure guidelines aiming to protect workers and the general public.

  5. Surface N Balances in Agricultural Crop Production Systems in China for the Period 1980-2015

    Institute of Scientific and Technical Information of China (English)

    SUN Bo; SHEN Run-Ping; A.F.BOUWMAN

    2008-01-01

    Surface nitrogen (N) balances for ChinEs crop production systems was estimated using statistical data collected from 1980 to 2004 at the national and provincial scale and from 1994 to 1999 at the county level.There was a surplus N balance throughout these periods,but the surplus was nearly stable in recent years.Projections using nonseasonal Box-Jenkins model or exponential models show that the N surplus for the total cultivated land in China was likely to increase from 142.8 kg ha-1 in 2004 to 168.6 kg ha-1 in 2015.The N balance surplus in the more developed southeastern provinces was the largest,and was slightly less in the central region,which caused the nitrate pollution in the ground water.The N surplus was much less in the western and northern provinces because of lower synthetic fertilizer inputs.The region with high N risk includes Beijing Municipality and Jiangsu,Zhejiang,Fujian,Guangdong,Hubei,and Shandong provinces for 2002-2004.The projections suggested that 15 provinces (or municipalities) in the middle and southeastern part of China except Jiangxi and Shanxi provinces would become the high-risk region by 2015.The level of economic development,transportation,and labor force condition had an important effect on the N balance surplus at the county level,but the last two factors showed remarkable impact at the provincial level.To decrease the nonpoint pollution (Npp) risk from crop production,the authors suggested to reduce the target level for national grain self-sufficiency to 90%-95% and change the regional structure of grain production by moving some of the future grain production from the high Npp risk areas of eastern China to parts of the central and western provinces where the Npp risk was much less.

  6. Steam System Balancing and Tuning for Multifamily Residential Buildings in Chicagoland - Second Year of Data Collection

    Energy Technology Data Exchange (ETDEWEB)

    Choi, J.; Ludwig, P.; Brand, L.

    2013-08-01

    Steam heated buildings often suffer from uneven heating as a result of poor control of the amount of steam entering each radiator. In order to satisfy the heating load to the coldest units, other units are overheated. As a result, some tenants complain of being too hot and open their windows in the middle of winter, while others complain of being too cold and are compelled to use supplemental heat sources. Building on previous research, CNT Energy identified 10 test buildings in Chicago and conducted a study to identify best practices for the methodology, typical costs, and energy savings associated with steam system balancing. A package of common steam balancing measures was assembled and data were collected on the buildings before and after these retrofits were installed to investigate the process, challenges, and the cost effectiveness of improving steam systems through improved venting and control systems. The test buildings that received venting upgrades and new control systems showed 10.2% savings on their natural gas heating load, with a simple payback of 5.1 years. The methodologies for and findings from this study are presented in detail in this report. This report has been updated from a version published in August 2012 to include natural gas usage information from the 2012 heating season and updated natural gas savings calculations.

  7. An estimation of the water balance in a reformer/fuel-cells system

    Energy Technology Data Exchange (ETDEWEB)

    Jovan, Vladimir [Jo-ef Stefan Institute and Centre of Excellence Low-Carbon Technologies (Slovenia); Cufar, Alja [University of Ljubljana, Faculty of Mathematics and Physics (Slovenia)], e-mail: vladimir.jovan@ijs.si

    2011-07-01

    PEM fuel cells use hydrogen as fuel. Since it is a very light element, its energy density is small despite its high caloric value. Thus hydrogen storage requires a lot of space. One possible solution is simultaneous production of hydrogen from higher-density materials, such as methanol. The object of this paper is to determine what is the total water balance in a system consisting of a methanol reformer and a fuel-cells-based generator set, and to determine if water should be supplied to, or removed from, the system. Based on relatively little information obtained from technical sources and on some simple assumptions, this paper presents a model which helps to determine the actual water balance in the system. In conclusion, commercially available fuel-cell systems with realistic water production can be used for fuel reforming purposes in the methanol reformer. It is also shown that under normal operating conditions, and using commercially available devices, there is always an excess of water produced.

  8. The Demand Side Management Potential to Balance a Highly Renewable European Power System

    Directory of Open Access Journals (Sweden)

    Alexander Kies

    2016-11-01

    Full Text Available Shares of renewables continue to grow in the European power system. A fully renewable European power system will primarily depend on the renewable power sources of wind and photovoltaics (PV, which are not dispatchable but intermittent and therefore pose a challenge to the balancing of the power system. To overcome this issue, several solutions have been proposed and investigated in the past, including storage, backup power, reinforcement of the transmission grid, and demand side management (DSM. In this paper, we investigate the potential of DSM to balance a simplified, fully renewable European power system. For this purpose, we use ten years of weather and historical load data, a power-flow model and the implementation of demand side management as a storage equivalent, to investigate the impact of DSM on the need for backup energy. We show that DSM has the potential to reduce the need for backup energy in Europe by up to one third and can cover the need for backup up to a renewable share of 67%. Finally, it is demonstrated that the optimal mix of wind and PV is shifted by the utilisation of DSM towards a higher share of PV, from 19% to 36%.

  9. A new accounting system for financial balance based on personnel cost after the introduction of a DPC/DRG system.

    Science.gov (United States)

    Nakagawa, Yoshiaki; Takemura, Tadamasa; Yoshihara, Hiroyuki; Nakagawa, Yoshinobu

    2011-04-01

    A hospital director must estimate the revenues and expenses not only in a hospital but also in each clinical division to determine the proper management strategy. A new prospective payment system based on the Diagnosis Procedure Combination (DPC/PPS) introduced in 2003 has made the attribution of revenues and expenses for each clinical department very complicated because of the intricate involvement between the overall or blanket component and a fee-for service (FFS). Few reports have so far presented a programmatic method for the calculation of medical costs and financial balance. A simple method has been devised, based on personnel cost, for calculating medical costs and financial balance. Using this method, one individual was able to complete the calculations for a hospital which contains 535 beds and 16 clinics, without using the central hospital computer system.

  10. The circadian system and the balance of the autonomic nervous system.

    Science.gov (United States)

    Buijs, Ruud M; Escobar, Carolina; Swaab, Dick F

    2013-01-01

    Our biological clock, the suprachiasmatic nucleus (SCN), sets the pace of our life: it provides a rhythmic function to our sleep-wake cycle. In order to do so properly the SCN synchronizes our physiology to behavioral patterns by directing the autonomic and hormonal output of the hypothalamus to the different organs of the body that require a different setting - activity or inactivity - during particular phases of the day or night. In this chapter we show that this delicate balance requires that the SCN should not only provide an output to these organs but also be informed about the physiological state of the organs in order to adapt its output. This occurs via a hypothalamic neuronal network that provides the necessary input to the SCN. We argue that the feedback that the SCN receives from its hypothalamic target structures is essential to maintain a balance in our physiological functions, which fluctuate during the sleep-wake cycle. We propose that this crucial role of the hypothalamus in the homeostatic response is the reason why, e.g., in aging or depression, changes in the functioning of the biological clock, the SCN, lead to the development of pathology. In addition, if this balance is not adequately organized, for example, if the signals of the biological clock are violated by being active and eating during the night, as in shift work, one will be more susceptible to diseases such as hypertension, obesity, diabetes, and metabolic syndrome.

  11. Fuzzy droop control loops adjustment for stored energy balance in distributed energy storage system

    DEFF Research Database (Denmark)

    Aldana, Nelson Leonardo Diaz; Wu, Dan; Dragicevic, Tomislav;

    2015-01-01

    The study of isolated AC microgrid has been under high interest due to the integration of renewable energy resources especially for remote areas, or to improve the local energy reliability. The current trend is oriented to distributed renewable energy sources and their corresponding energy storage...... system, in order to smooth the variations at the prime energy generator. In this paper, a decentralized strategy based on fuzzy logic is proposed in order to balance the state of charge of distributed energy storage systems in lowvoltage three phase AC microgrid. The proposed method weights the action...... of conventional droop control loops for battery based distributed energy storage systems, in order to equalize their stored energy. The units are selfcontrolled by using local variables, hence, the microgrid can operate without communication systems. Frequency and voltage bus signaling are used in order...

  12. Vibration analysis of nonlinear systems with the bilinear hysteretic oscillator by using incremental harmonic balance method

    Science.gov (United States)

    Xiong, Huai; Kong, Xianren; Li, Haiqin; Yang, Zhenguo

    2017-01-01

    This paper considers dynamics of bilinear hysteretic systems, which are widely used for vibration control and vibration absorption such as magneto-rheological damper, metal-rubber. The method of incremental harmonic balance (IHB) technique that hysteresis is considered in the corrective term is improved in order to determine periodic solutions of bilinear hysteretic systems. The improved continuation method called two points tracing algorithm which is stable to the turning point makes the calculation more efficient for tracing amplitude-frequency response. Precise Hsu's method for analysing the stability of periodic solutions is introduced. The effects of different parameters of bilinear hysteretic oscillator on the response are discussed numerically. Some numerical simulations of considered bilinear hysteretic systems, including a single DOF and a 2DOF system, are effectively obtained by the modified IHB method and the results compare very well with the 4-oder Runge-Kutta method.

  13. Real-time impact of power balancing on power system operation with large scale integration of wind power

    DEFF Research Database (Denmark)

    Basit, Abdul; Hansen, Anca Daniela; Sørensen, Poul Ejnar

    2016-01-01

    Highly wind power integrated power system requires continuous active power regulation to tackle the power imbalances resulting from the wind power forecast errors. The active power balance is maintained in real-time with the automatic generation control and also from the control room, where...... regulating power bids are activated manually. In this article, an algorithm is developed to simulate the activation of regulating power bids, as performed in the control room, during power imbalance between generation and load demand. In addition, the active power balance is also controlled through automatic...... power system model. The power system model takes the hour-ahead regulating power plan from power balancing model and the generation and power exchange capacities for the year 2020 into account. The real-time impact of power balancing in a highly wind power integrated power system is assessed...

  14. A forecast of new test capabilities using Magnetic Suspension and Balance Systems

    Science.gov (United States)

    Lawing, Pierce L.; Johnson, William G., Jr.

    1988-01-01

    This paper outlines the potential of Magnetic Suspension and Balance System (MSBS) technology to solve existing problems related to support interference in wind tunnels. Improvement of existing test techniques and exciting new techniques are envisioned as a result of applying MSBS. These include improved data accuracy, dynamic stability testing, two-body/stores release testing, and pilot/designer-in-the-loop tests. It also discusses the use of MSBS for testing exotic configurations such as hybrid hypersonic vehicles. A new facility concept that combines features of ballistic tubes, magnetic suspension, and cryogenic tunnels is described.

  15. A new metal detection method based on balanced coil for mobile phone wireless charging system

    Science.gov (United States)

    Zhou, B.; Liu, Z. Z.; Chen, H. X.; Zeng, H.; Hei, T.

    2016-08-01

    The wireless charging time of mobile phone will increase greatly if the metal objects mix in the magnetic field coupling area. In addition, the fire may be caused as for the high temperature of metal objects. The paper proposed an improved detecting method based on balance coil for mobile phone wireless charging system according to comparing the advantages and disadvantages of traditional metal detection methods. The circuit model was established, and hardware and software were optimized. At last, experimental results verified the theoretical analysis.

  16. Formative Classroom Assessment and Large-Scale Assessment: Toward a More Balanced System

    Directory of Open Access Journals (Sweden)

    Felipe Martínez Rizo

    2009-11-01

    Full Text Available Given the proliferation of large-scale standardized tests that has occurred in Mexico in recent years, this article constitutes a review of the international literature on the subject for the purpose of reflecting on the possible consequences of this phenomenon and exploring the progress of alternative assessment approaches. It also reviews the development of concepts related to formative classroom assessment, and summarizes current thinking on this subject. It emphasizes the importance of such approaches for improving educational quality. In conclusion, it argues that it is necessary to move toward assessment systems that combine large-scale assessment and classroom assessment in a more balanced fashion.

  17. Self-organizing method for collaboration in multi-robot system on basis of balance principle

    Institute of Scientific and Technical Information of China (English)

    Yangbin DONA; Jinping JIANG; Yan HE

    2008-01-01

    By analyzing the operation characteristics of two subtasks that have resource dependency on each other, this paper demonstrates the impact of progress relation between the two subtasks on the whole task's progress, and then puts forward a self-organizing prin-ciple called balance principle that keeps the individual profit between robots equal. Furthermore, an algorithm is designed for adjusting subtask selection on the basis of this principle. Simulation shows the validity of the algorithm on self-organizing task allocation in a multi-robot system.

  18. Battery system and method for sensing and balancing the charge state of battery cells

    Science.gov (United States)

    Davies, Francis J. (Inventor)

    2012-01-01

    A battery system utilizes a plurality of transformers interconnected with the battery cells. The transformers each have at least one transformer core operable for magnetization in at least a first magnetic state with a magnetic flux in a first direction and a second magnetic state with a magnetic flux in a second direction. The transformer cores retain the first magnetic state and the second magnetic state without current flow through said plurality of transformers. Circuitry is utilized for switching a selected transformer core between the first and second magnetic states to sense voltage and/or balance particular cells or particular banks of cells.

  19. The Balanced Scorecard: A Systemic Model for Evaluation and Assessment of Learning Outcomes?

    Directory of Open Access Journals (Sweden)

    Tom Bielavitz

    2010-06-01

    Full Text Available Objective – The goal of this paper is to explore using Kaplan and Norton’s balanced scorecard methodology as a systemic model for outcomes assessment. The expectations of academic accrediting agencies have shifted from measurement of inputs and outputs to that of the library’s impact on learning and demonstrating accountability. Recent literature has presented methods for performing specific aspects of outcomes assessment. However, the scorecard methodology may provide a systemic advantage beneficial to library administrators and managers.Methods – This paper provides a selective review of outcomes assessment in academic libraries and a description of the balanced scorecard methodology, focusing on its relevance to assessment and demonstration of accountability.Results – A theoretical scenario is outlined, including examples of a scorecard used for outcomes assessment. For each example, the benefits of using a systemic approach are examined.Conclusions – Using a systems‐thinking approach to outcomes assessment may provide significant advantages to library administrators and managers. As the model includes traditional methods of outcomes assessment, the scorecard approach adds elements of process improvement, identification of the inputs and outputs that create outcomes, and a tool for communicating accountability for resources.

  20. “Feed Assist”- An Expert System on Balanced Feeding for Dairy Animals

    Directory of Open Access Journals (Sweden)

    U.B Angadi

    2016-09-01

    Full Text Available Inadequate feeding is the major factor for low livestock productivity in India. In dairying, feed cost is a major input and feeding practices has to be improved to ensure profits. Still the small scale farmers are following traditional feeding practices and fail to address the complexities involved in ration formulation. To address the complexities in ration balancing based on the nutrient requirements for different categories of livestock, nutrient composition of wide range of feed resources and the cost - a number of expert systems have been developed. However existing expert systems have not been widely used by majority of small farmers due to lack of awareness, access and basic skills required to operate. To address these limitations, “Feed Assist” a farmer friendly expert system for balanced feeding of dairy animals at least cost has been developed using linear programming. “Feed Assist” does not require much expertise to operate and enables the farmers to formulate least cost rations for different categories of livestock using locally available feed resources.

  1. Judicial Control over Althingi: Altered Balance of Powers in the Constitutional System

    Directory of Open Access Journals (Sweden)

    Björg Thorarensen

    2016-06-01

    Full Text Available The article focuses on how the control of the judiciary over the legislature has increased in the last decades and the reasons for altered balance of powers in the Icelandic constitutional system are explored. Earlier theories of parliamentary precedence over other branches of state power are in transition. There is a growing trend towards the balancing of powers, in which the courts monitor that legislation complies with the constitution. A comparison is made with the developments in the constitutional systems of Denmark and Norway which points at the same direction. The European Convention on Human Rights and constitutional amendments in 1995 have affected the interpretation methods of the Icelandic courts and strengthened their supervisory role. Ideas underlying constitutional democracy, rule of law and effective remedies for individuals are prevailing over the idea of preferred position of the legislative power vis-à-vis the judiciary. The courts see it as a constitutional duty to adjudicate whether a legislative act conforms with constitutional human rights. The Supreme Court of Iceland has referred to the wide discretion of the legislature in the field of fiscal powers, such as regarding taxation and the social security system. However, even where legislation aims at the implementation of important political policies, the discretion of Althingi is subject to certain limits. The effective judicial control requires that Althingi must assess carefully whether legislation which limits constitutionally protected human rights conforms with the principles of equality and proportionality.

  2. Conjoint Analysis of the Surface and Atmospheric Water Balances of the Andes-Amazon System

    Science.gov (United States)

    Builes-Jaramillo, Alejandro; Poveda, Germán

    2017-04-01

    Acknowledging the interrelation between the two branches of the hydrological cycle, we perform a comprehensive analysis of the long-term mean surface and atmospheric water balances in the Amazon-Andes River basins system. We estimate the closure of the water budgets based on the long-term approximation of the water balance equations, and estimate the imbalance between both atmospheric and surface budgets. The analysis was performed with observational and reanalysis datasets for the entire basin, for several sub-catchments inside the entire Amazon River basin and for two physical and geographical distinctive subsystems of the basin, namely upper Andean the low-lying Amazon River basin. Our results evidence that for the entire Amazon River basin the surface water balance can be considered to be in balance (P = 2225 mm.yr-1, ET= 1062 mm.yr-1, R= 965 mm.yr-1), whereas for the separated subsystems it not so clear, showing high discrepancies between observations and reanalysis datasets. In turn, the atmospheric budget does not close regardless of datasets or geographical disaggregation. Our results indicate that the amount of imbalance of the atmospheric branch of the water balance depends on the evaporation data source used. The imbalance calculated as I=(C/R)-1, where C is net moisture convergence (C= -∇Q where ∇Q is the net vertically integrated moisture divergence) and R the runoff,represents the difference between the two branches of the hydrological cycle. For the entire Amazon River basin we found a consistent negative imbalance driven by higher values of runoff, and when calculated for monthly time scales the imbalance is characterized by a high dependence on the Amazon dry season. The separated analysis performed to the Andes and Low-lying Amazonia subsystems unveils two shortcomings of the available data, namely a poor quality of the representation of surface processes in the reanalysis models (including precipitation and evapotranspiration), and the

  3. Reduced storage and balancing needs in a fully renewable European power system with excess wind and solar power generation

    DEFF Research Database (Denmark)

    Heide, Dominik; Greiner, Martin; von Bremen, Lüder

    2011-01-01

    The storage and balancing needs of a simplified European power system, which is based on wind and solar power generation only, are derived from an extensive weather-driven modeling of hourly power mismatches between generation and load. The storage energy capacity, the annual balancing energy...... and the balancing power are found to depend significantly on the mixing ratio between wind and solar power generation. They decrease strongly with the overall excess generation. At 50% excess generation the required long-term storage energy capacity and annual balancing energy amount to 1% of the annual consumption....... The required balancing power turns out to be 25% of the average hourly load. These numbers are in agreement with current hydro storage lakes in Scandinavia and the Alps, as well as with potential hydrogen storage in mostly North-German salt caverns....

  4. Reduced storage and balancing needs in a fully renewable European power system with excess wind and solar power generation

    DEFF Research Database (Denmark)

    Heide, Dominik; Greiner, Martin; von Bremen, Lüder

    The storage and balancing needs of a simplified European power system, which is based on wind and solar power generation only, are derived from an extensive weather-driven modeling of hourly power mismatches between generation and load. The storage energy capacity, the annual balancing energy...... and the balancing power are found to depend significantly on the mixing ratio between wind and solar power generation. They decrease strongly with the overall excess generation. At 50% excess generation the required long-term storage energy capacity and annual balancing energy amount to 1% of the annual consumption....... The required balancing power turns out to be 25% of the average hourly load. These numbers are in agreement with current hydro storage lakes in Scandinavia and the Alps, as well as with potential hydrogen storage in mostly North-German salt caverns....

  5. A Plantar-pressure Based Tongue-placed Tactile Biofeedback System for Balance Improvement

    CERN Document Server

    Vuillerme, Nicolas; Pinsault, Nicolas; Fleury, Anthony; Demongeot, Jacques; Payan, Yohan

    2007-01-01

    Maintaining an upright stance represents a complex task, which is achieved by integrating sensory information from the visual, vestibular and somatosensory systems. When one of these sensory inputs becomes unavailable and/or inaccurate and/or unreliable, postural control generally is degraded. One way to solve this problem is to supplement and/or substitute limited/altered/missing sensory information by providing additional sensory information to the central nervous system via an alternative sensory modality. Along these lines, we developed an original biofeedback system [1] whose underlying principle consists in supplying the user with supplementary sensory information related to foot sole pressure distribution through a tongue-placed output device (Tongue Display Unit, "TDU" [2]). The purpose of the present experiment was to assess its effectiveness in improving balance in young healthy adults.

  6. Role of the endocannabinoid system in energy balance regulation and obesity.

    Science.gov (United States)

    Cota, Daniela

    2008-01-01

    The endogenous cannabinoid system (ECS) is a neuromodulatory system recently recognized to have a role in the regulation of various aspects of eating behavior and energy balance through central and peripheral mechanisms. In the central nervous system, cannabinoid type 1 receptors and their endogenous ligands, the endocannabinoids, are involved in modulating food intake and motivation to consume palatable food. Moreover, the ECS is present in peripheral organs, such as liver, white adipose tissue, muscle, and pancreas, where it seems to be involved in the regulation of lipid and glucose homeostasis. Dysregulation of the ECS has been associated with the development of obesity and its sequelae, such as dyslipidemia and diabetes. Conversely, recent clinical trials have shown that cannabinoid type 1 receptor blockade may ameliorate these metabolic abnormalities. Although further investigation is needed to better define the actual mechanisms of action, pharmacologic approaches targeting the ECS may provide a novel, effective option for the management of obesity, type 2 diabetes and cardiovascular disease.

  7. Balance in Assessment

    Science.gov (United States)

    White, Richard

    2007-01-01

    The review by Black and Wiliam of national systems makes clear the complexity of assessment, and identifies important issues. One of these is "balance": balance between local and central responsibilities, balance between the weights given to various purposes of schooling, balance between weights for various functions of assessment, and balance…

  8. An investigation of the hydrodynamic relationships in the gas formations of the upper and lower Pannon of the Aldye deposit. [Includes calculations of gas coming from different strata

    Energy Technology Data Exchange (ETDEWEB)

    Zoltan, B.; Istvan, P.; Laszlo, V.; Tibor, M.

    1985-01-01

    The problems in developing gas formations of complex structure which are bedded one under the other and are associated with a hydrodynamic link are analyzed. A great number of ratings of the material balance was conducted in order to refine the reserves of the deposits and to explain the hydrodynamic relationships of individual formations and their groups. A complex rating program is developed for a computer (EVM) which may be used to model the process of development of gas collectors of a complex system in a stratum and the operation of wells and oil field pipelines with consideration of assigned boundary (threshold) conditions.

  9. Anisotropic hydrodynamics -- basic concepts

    CERN Document Server

    Florkowski, Wojciech; Ryblewski, Radoslaw; Strickland, Michael

    2013-01-01

    Due to the rapid longitudinal expansion of the quark-gluon plasma created in relativistic heavy ion collisions, potentially large local rest frame momentum-space anisotropies are generated. The magnitude of these momentum-space anisotropies can be so large as to violate the central assumption of canonical viscous hydrodynamical treatments which linearize around an isotropic background. In order to better describe the early-time dynamics of the quark gluon plasma, one can consider instead expanding around a locally anisotropic background which results in a dynamical framework called anisotropic hydrodynamics. In this proceedings contribution we review the basic concepts of the anisotropic hydrodynamics framework presenting viewpoints from both the phenomenological and microscopic points of view.

  10. Balance Improvement Effects of Biofeedback Systems with State-of-the-Art Wearable Sensors: A Systematic Review.

    Science.gov (United States)

    Ma, Christina Zong-Hao; Wong, Duo Wai-Chi; Lam, Wing Kai; Wan, Anson Hong-Ping; Lee, Winson Chiu-Chun

    2016-03-25

    Falls and fall-induced injuries are major global public health problems. Balance and gait disorders have been the second leading cause of falls. Inertial motion sensors and force sensors have been widely used to monitor both static and dynamic balance performance. Based on the detected performance, instant visual, auditory, electrotactile and vibrotactile biofeedback could be provided to augment the somatosensory input and enhance balance control. This review aims to synthesize the research examining the effect of biofeedback systems, with wearable inertial motion sensors and force sensors, on balance performance. Randomized and non-randomized clinical trials were included in this review. All studies were evaluated based on the methodological quality. Sample characteristics, device design and study characteristics were summarized. Most previous studies suggested that biofeedback devices were effective in enhancing static and dynamic balance in healthy young and older adults, and patients with balance and gait disorders. Attention should be paid to the choice of appropriate types of sensors and biofeedback for different intended purposes. Maximizing the computing capacity of the micro-processer, while minimizing the size of the electronic components, appears to be the future direction of optimizing the devices. Wearable balance-improving devices have their potential of serving as balance aids in daily life, which can be used indoors and outdoors.

  11. Balance Improvement Effects of Biofeedback Systems with State-of-the-Art Wearable Sensors: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Christina Zong-Hao Ma

    2016-03-01

    Full Text Available Falls and fall-induced injuries are major global public health problems. Balance and gait disorders have been the second leading cause of falls. Inertial motion sensors and force sensors have been widely used to monitor both static and dynamic balance performance. Based on the detected performance, instant visual, auditory, electrotactile and vibrotactile biofeedback could be provided to augment the somatosensory input and enhance balance control. This review aims to synthesize the research examining the effect of biofeedback systems, with wearable inertial motion sensors and force sensors, on balance performance. Randomized and non-randomized clinical trials were included in this review. All studies were evaluated based on the methodological quality. Sample characteristics, device design and study characteristics were summarized. Most previous studies suggested that biofeedback devices were effective in enhancing static and dynamic balance in healthy young and older adults, and patients with balance and gait disorders. Attention should be paid to the choice of appropriate types of sensors and biofeedback for different intended purposes. Maximizing the computing capacity of the micro-processer, while minimizing the size of the electronic components, appears to be the future direction of optimizing the devices. Wearable balance-improving devices have their potential of serving as balance aids in daily life, which can be used indoors and outdoors.

  12. Dispersive hydrodynamics: Preface

    Science.gov (United States)

    Biondini, G.; El, G. A.; Hoefer, M. A.; Miller, P. D.

    2016-10-01

    This Special Issue on Dispersive Hydrodynamics is dedicated to the memory and work of G.B. Whitham who was one of the pioneers in this field of physical applied mathematics. Some of the papers appearing here are related to work reported on at the workshop "Dispersive Hydrodynamics: The Mathematics of Dispersive Shock Waves and Applications" held in May 2015 at the Banff International Research Station. This Preface provides a broad overview of the field and summaries of the various contributions to the Special Issue, placing them in a unified context.

  13. Energy balance in olive oil farms: comparison of organic and conventional farming systems.

    Science.gov (United States)

    Moreno, Marta M.; Meco, Ramón; Moreno, Carmen

    2013-04-01

    The viability of an agricultural production system not only depends on the crop yields, but especially on the efficient use of available resources. However, the current agricultural systems depend heavily on non-renewable energy consumption in the form of fertilizers, fossil fuels, pesticides and machinery. In developed countries, the economic profitability of different productive systems is dependent on the granting of subsidies of diverse origin that affect both production factors (or inputs) and the final product (or output). Leaving such external aids, energy balance analysis reveals the real and most efficient form of management for each agroclimatic region, and is also directly related to the economic activity and the environmental state. In this work we compare the energy balance resulting from organic and conventional olive oil farms under the semi-arid conditions of Central Spain. The results indicate that the mean energy supplied to the organic farms was sensitively lower (about 30%) in comparison with the conventional management, and these differences were more pronounced for the biggest farms (> 15 ha). Mean energy outputs were about 20% lower in the organic system, although organic small farms (< 15 ha) resulted more productive than the conventional small ones. However, these lower outputs were compensated by the major market value obtained from the organic products. Chemical fertilizers and pesticides reached about 60% of the total energy inputs in conventional farming; in the organic farms, however, this ratio scarcely reached 25%. Human labor item only represented a very small amount of the total energy input in both cases (less than 1%). As conclusions, both management systems were efficient from an energy point of view. The value of the organic production should be focused on the environmental benefits it provides, which are not usually considered in the conventional management on not valuing the damage it produces to the environment. Organic

  14. Development of a PEMFC Power System with Integrated Balance of Plant

    Science.gov (United States)

    Wynne, B.; Diffenderfer, C.; Ferguson, S.; Keyser, J.; Miller, M.; Sievers, B.; Ryan, A.; Vasquez, A.

    2012-01-01

    Autonomous Underwater Vehicles (AUV s) have received increasing attention in recent years as military and commercial users look for means to maintain a mobile and persistent presence in the undersea world. Compact, neutrally buoyant power systems are needed for both small and large vehicles. Batteries are usually employed in these applications, but the energy density and therefore the mission duration are limited with current battery technology. At a certain energy or mission duration requirement, other means to get long duration power become feasible. For example, above 10 kW-hrs liquid oxygen and hydrogen have better specific energy than batteries and are preferable for energy storage as long as a compact system of about 100 W/liter is achievable to convert the chemical energy in these reactants into power. Other reactant forms are possible, such as high pressure gas, chemical hydrides or oxygen carriers, but it is essential that the power system be small and light weight. Recent fuel cell work, primarily focused on NASA applications, has developed power systems that can meet this target power density. Passive flow-through systems, using ejector driven reactant (EDR) flow, integrated into a compact balance of plant have been developed. These systems are thermally and functionally integrated in much the same way as are automotive, air breathing fuel cell systems. These systems fit into the small volumes required for AUV and future NASA applications. Designs have been developed for both a 21" diameter and a larger diameter (LD) AUV. These fuel cell systems occupy a very small portion of the overall energy system, allowing most of the system volume to be used for the reactants. The fuel cell systems have been optimized to use reactants efficiently with high stack efficiency and low parasitic losses. The resulting compact, highly efficient fuel cell system provides exceptional reactant utilization and energy density. Key design variables and supporting test data are

  15. Hydrodynamics of spacetime and vacuum viscosity

    CERN Document Server

    Eling, Christopher

    2008-01-01

    It has recently been shown that the Einstein equation can be derived by demanding a non-equilibrium entropy balance law dS = dQ/T + dS_i hold for all local acceleration horizons through each point in spacetime. The entropy change dS is proportional to the change in horizon area while dQ and T are the energy flux across the horizon and Unruh temperature seen by an accelerating observer just inside the horizon. The internal entropy production term dS_i is proportional to the squared shear of the horizon and the ratio of the proportionality constant to the area entropy density must be \\hbar/4\\pi. Here we will show that this derivation can be reformulated in the language of hydrodynamics. We postulate that the vacuum thermal state in the Rindler wedge of spacetime obeys the holographic principle. Hydrodynamic perturbations of this state exist and are manifested in the dynamics of a stretched horizon fluid at the horizon boundary. Using the equations of hydrodynamics we derive the entropy balance law and show the ...

  16. A New and Better Method for Designing and Simulating Hydrodynamic Resistance Servo Compensation System%水动阻力随动补偿系统设计与仿真分析

    Institute of Scientific and Technical Information of China (English)

    李玥; 朱战霞

    2012-01-01

    To compensate for hydrodynamic resistance during experiments on neutral buoyancy, we propose a new method for designing and simulating hydrodynamic resistance servo compensation system, which we believe is new and better than previous ones. Sections 1 and 2 of the full paper explain our method. Their core consists of; ( 1) we combine the traditional PID control with fuzzy control so as to perform fuzzy inference of unknown information and online learning with artificial intelligence, thus effectively handling the nonlinearity and uncertainty of the actuator control system and adjusting its PI parameters on line and in real time; ( 2) we apply our method to the closed loop control system of the hydrodynamic resistance servo compensation system; (3) using the fuzzy logic toolbox of MATLAB, we design and simulate the hydrodynamic resistance servo compensation system; the simulation results, given in Figs. 6(a) and (b) , and their comparison show preliminarily that the closed loop control system we designed has no overshoot but faster response than the traditional PID control method, thus effectively compensating for hydrodynamic resistance.%针对中性浮力实验中水动阻力的补偿问题,提出了一种参数自整定模糊PI控制方法,即采用传统的PID控制与模糊控制相结合的新型控制方法.将方法应用于水动阻力补偿系统的控制闭环中,并利用MATLAB软件中的模糊控制工具箱进行了系统的辅助设计与仿真.仿真结果表明,参数自整定模糊P1控制可改善水动阻力补偿系统的动态性能,该方法是水动阻力实时补偿的有效方法.

  17. Psychometric properties of Brief-Balance Evaluation Systems Test (Brief-BESTest) in evaluating balance performance in individuals with chronic stroke.

    Science.gov (United States)

    Huang, Meizhen; Pang, Marco Y C

    2017-03-01

    To examine the psychometric properties of the Brief-Balance Evaluation Systems Test (Brief-BESTest) in individuals with chronic stroke. This was an observational study with repeated measurements involving 50 participants with chronic stroke [mean (SD) age: 59.2 (7.3) years]. Each participant with stroke was evaluated with the Brief-BESTest, Berg balance scale (BBS), Postural Assessment Scale for Stroke Patients (PASS), Fugl-Meyer Motor Assessment (FMA), Chedoke-McMaster Stroke Assessment (CMSA), Montreal Cognitive Assessment (MoCA), and Geriatric Depression Scale (GDS). Two raters (rater 1 and 2) provided the Brief-BESTest scores of the first 27 participants independently to establish inter-rater reliability. After 15 min of rest, the same 27 participants were evaluated with the Brief-BESTest again by rater 1 to establish intra-rater reliability. The Brief-BESTest scores of the stroke group were also compared with those of the control group [n = 27, mean (SD) age: 56.7 (7.7) years]. The Brief-BESTest had no substantial floor and ceiling effects, good intra-rater (ICC 2,1 = 0.974) and inter-rater (ICC 2,1 = 0.980) reliability and internal consistency (Cronbach's alpha = 0.818). The minimal detectable change at 95% confidence level was 2 points. The Brief-BESTest showed moderate to very strong correlations with other balance (BBS and PASS) and motor impairment (FMA, CMSA) measures (rs = .547-.911, p Brief-BESTest was effective in distinguishing participants with stroke from controls (cutoff score: Brief-BESTest has good reliability and validity in assessing balance function in individuals with chronic stroke.

  18. The endocannabinoid system as a link between homoeostatic and hedonic pathways involved in energy balance regulation.

    Science.gov (United States)

    Di Marzo, V; Ligresti, A; Cristino, L

    2009-06-01

    The endocannabinoid system (ECS) and, in particular, cannabinoid CB(1) receptors, their endogenous agonists (the endocannabinoids anandamide and 2-arachidonoylglycerol) and enzymes for the biosynthesis and degradation of the latter mediators are emerging as key players in the control of all aspects of food intake and energy balance. The ECS is involved in stimulating both the homoeostatic (that is, the sensing of deficient energy balance and gastrointestinal load) and the hedonic (that is, the sensing of the salience and the incentive/motivational value of nutrients) aspects of food intake. The orexigenic effects of endocannabinoids are exerted in the brain by CB(1)-mediated stimulatory and inhibitory effects on hypothalamic orexigenic and anorectic neuropeptides, respectively; by facilitatory actions on dopamine release in the nucleus accumbens shell; and by regulating the activity of sensory and vagal fibres in brainstem-duodenum neural connections. In turn, the levels of anandamide and 2-arachidonoylglycerol and/or CB(1) receptors in the brain are under the control of leptin, ghrelin and glucocorticoids in the hypothalamus, under that of dopamine in the limbic forebrain and under that of cholecystokinin and ghrelin in the brainstem. These bi-directional communications between the ECS and other key players in energy balance ensure local mediators such as the endocannabinoids to act in a way coordinated in both 'space' and 'time' to enhance food intake, particularly after a few hours of food deprivation. Alterations of such communications are, however, also among the underlying causes of overactivity of the ECS in hyperphagia and obesity, a phenomenon that provided the rationale for the development of anti-obesity drugs from CB(1) receptor antagonists.

  19. Characteristics of nitrogen balance in open-air and greenhouse vegetable cropping systems of China.

    Science.gov (United States)

    Ti, Chaopu; Luo, Yongxia; Yan, Xiaoyuan

    2015-12-01

    Nitrogen (N) loss from vegetable cropping systems has become a significant environmental issue in China. In this study, estimation of N balances in both open-air and greenhouse vegetable cropping systems in China was established. Results showed that the total N input in open-air and greenhouse vegetable cropping systems in 2010 was 5.44 and 2.60 Tg, respectively. Chemical fertilizer N input in the two cropping systems was 201 kg N ha(-1) per season (open-air) and 478 kg N ha(-1) per season (greenhouse). The N use efficiency (NUE) was 25.9 ± 13.3 and 19.7 ± 9.4% for open-air and greenhouse vegetable cropping systems, respectively, significantly lower than that of maize, wheat, and rice. Approximately 30.6% of total N input was accumulated in soils and 0.8% was lost by ammonia volatilization in greenhouse vegetable system, while N accumulation and ammonia volatilization accounted for 19.1 and 11.1%, respectively, of total N input in open-air vegetable systems.

  20. Design and development of major balance of plant components in solid oxide fuel cell system

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Wen-Tang; Huang, Cheng-Nan; Tan, Hsueh-I; Chao, Yu [Institute of Nuclear Energy Research Atomic Energy Council, Taoyuan County 32546 (Taiwan, Province of China); Yen, Tzu-Hsiang [Green Technology Research Institute, CPC Corporation, Chia-Yi City 60036 (Taiwan, Province of China)

    2013-07-01

    The balance of plant (BOP) of a Solid Oxide Fuel Cell (SOFC) system with a 2 kW stack and an electric efficiency of 40% is optimized using commercial GCTool software. The simulation results provide a detailed understanding of the optimal operating temperature, pressure and mass flow rate in all of the major BOP components, i.e., the gas distributor, the afterburner, the reformer and the heat exchanger. A series of experimental trials are performed to validate the simulation results. Overall, the results presented in this study not only indicate an appropriate set of operating conditions for the SOFC power system, but also suggest potential design improvements for several of the BOP components.

  1. Cross-correlation of output fluctuation and system-balancing cost in photovoltaic integration

    Directory of Open Access Journals (Sweden)

    Yuichi Ikeda

    2014-10-01

    Full Text Available The authors analysed the cross-correlation of photovoltaic (PV output fluctuation for the actual PV output time series data in both the Tokyo area and the whole of Japan using the principal component analysis with the random matrix theory. Based on the obtained cross-correlation coefficients, the forecast error for PV output was estimated with/without considering the cross-correlations. Then the operation schedule of thermal plants is calculated to integrate PV output using the proposed unit commitment model with the estimated forecast error. The system-balancing cost of PV system was also estimated with or without demand response. Finally, validity of the concept of ‘local production for local consumption of renewable energy’ and alternative policy implications were discussed.

  2. Slurry bubble column hydrodynamics

    Science.gov (United States)

    Rados, Novica

    Slurry bubble column reactors are presently used for a wide range of reactions in both chemical and biochemical industry. The successful design and scale up of slurry bubble column reactors require a complete understanding of multiphase fluid dynamics, i.e. phase mixing, heat and mass transport characteristics. The primary objective of this thesis is to improve presently limited understanding of the gas-liquid-solid slurry bubble column hydrodynamics. The effect of superficial gas velocity (8 to 45 cm/s), pressure (0.1 to 1.0 MPa) and solids loading (20 and 35 wt.%) on the time-averaged solids velocity and turbulent parameter profiles has been studied using Computer Automated Radioactive Particle Tracking (CARPT). To accomplish this, CARPT technique has been significantly improved for the measurements in highly attenuating systems, such as high pressure, high solids loading stainless steel slurry bubble column. At a similar set of operational conditions time-averaged gas and solids holdup profiles have been evaluated using the developed Computed Tomography (CT)/Overall gas holdup procedure. This procedure is based on the combination of the CT scans and the overall gas holdup measurements. The procedure assumes constant solids loading in the radial direction and axially invariant cross-sectionally averaged gas holdup. The obtained experimental holdup, velocity and turbulent parameters data are correlated and compared with the existing low superficial gas velocities and atmospheric pressure CARPT/CT gas-liquid and gas-liquid-solid slurry data. The obtained solids axial velocity radial profiles are compared with the predictions of the one dimensional (1-D) liquid/slurry recirculation phenomenological model. The obtained solids loading axial profiles are compared with the predictions of the Sedimentation and Dispersion Model (SDM). The overall gas holdup values, gas holdup radial profiles, solids loading axial profiles, solids axial velocity radial profiles and solids

  3. Nonequilibrium steady state in open quantum systems: Influence action, stochastic equation and power balance

    Energy Technology Data Exchange (ETDEWEB)

    Hsiang, J.-T., E-mail: cosmology@gmail.com [Center for Field Theory and Particle Physics, Fudan University, Shanghai 200433 (China); Department of Physics, National Dong Hwa University, Hualien 97401, Taiwan (China); Hu, B.L. [Center for Field Theory and Particle Physics, Fudan University, Shanghai 200433 (China); Joint Quantum Institute and Maryland Center for Fundamental Physics, University of Maryland, College Park, MD 20742 (United States)

    2015-11-15

    The existence and uniqueness of a steady state for nonequilibrium systems (NESS) is a fundamental subject and a main theme of research in statistical mechanics for decades. For Gaussian systems, such as a chain of classical harmonic oscillators connected at each end to a heat bath, and for classical anharmonic oscillators under specified conditions, definitive answers exist in the form of proven theorems. Answering this question for quantum many-body systems poses a challenge for the present. In this work we address this issue by deriving the stochastic equations for the reduced system with self-consistent backaction from the two baths, calculating the energy flow from one bath to the chain to the other bath, and exhibiting a power balance relation in the total (chain + baths) system which testifies to the existence of a NESS in this system at late times. Its insensitivity to the initial conditions of the chain corroborates to its uniqueness. The functional method we adopt here entails the use of the influence functional, the coarse-grained and stochastic effective actions, from which one can derive the stochastic equations and calculate the average values of physical variables in open quantum systems. This involves both taking the expectation values of quantum operators of the system and the distributional averages of stochastic variables stemming from the coarse-grained environment. This method though formal in appearance is compact and complete. It can also easily accommodate perturbative techniques and diagrammatic methods from field theory. Taken all together it provides a solid platform for carrying out systematic investigations into the nonequilibrium dynamics of open quantum systems and quantum thermodynamics. -- Highlights: •Nonequilibrium steady state (NESS) for interacting quantum many-body systems. •Derivation of stochastic equations for quantum oscillator chain with two heat baths. •Explicit calculation of the energy flow from one bath to the

  4. Balanced Scorecard--A Strategic Management System of the Higher Education Institution

    Science.gov (United States)

    Hladchenko, Myroslava

    2015-01-01

    Purpose: The purpose of this paper is to focus on the comparative analysis of the Balanced Scorecards of four higher education institutions and aims to define the general framework of the Balanced Scorecard for the higher education institution which concerns: the structure and elements of the Balanced Scorecard; development of the Balanced…

  5. Balanced Scorecard--A Strategic Management System of the Higher Education Institution

    Science.gov (United States)

    Hladchenko, Myroslava

    2015-01-01

    Purpose: The purpose of this paper is to focus on the comparative analysis of the Balanced Scorecards of four higher education institutions and aims to define the general framework of the Balanced Scorecard for the higher education institution which concerns: the structure and elements of the Balanced Scorecard; development of the Balanced…

  6. Smoothed Particle Hydrodynamic Simulator

    Energy Technology Data Exchange (ETDEWEB)

    2016-10-05

    This code is a highly modular framework for developing smoothed particle hydrodynamic (SPH) simulations running on parallel platforms. The compartmentalization of the code allows for rapid development of new SPH applications and modifications of existing algorithms. The compartmentalization also allows changes in one part of the code used by many applications to instantly be made available to all applications.

  7. A Virtual Reality-Cycling Training System for Lower Limb Balance Improvement

    Directory of Open Access Journals (Sweden)

    Chieh Yin

    2016-01-01

    Full Text Available Stroke survivors might lose their walking and balancing abilities, but many studies pointed out that cycling is an effective means for lower limb rehabilitation. However, during cycle training, the unaffected limb tends to compensate for the affected one, which resulted in suboptimal rehabilitation. To address this issue, we present a Virtual Reality-Cycling Training System (VRCTS, which senses the cycling force and speed in real-time, analyzes the acquired data to produce feedback to patients with a controllable VR car in a VR rehabilitation program, and thus specifically trains the affected side. The aim of the study was to verify the functionality of the VRCTS and to verify the results from the ten stroke patients participants and to compare the result of Asymmetry Ratio Index (ARI between the experimental group and the control group, after their training, by using the bilateral pedal force and force plate to determine any training effect. The results showed that after the VRCTS training in bilateral pedal force it had improved by 0.22 (p=0.046 and in force plate the stand balance has also improved by 0.29 (p=0.031; thus both methods show the significant difference.

  8. Assessment of green roof systems in terms of water and energy balance

    Directory of Open Access Journals (Sweden)

    Mert Ekşi

    2016-01-01

    Full Text Available Green roofs concept term is used for extensive green roofs which are planted with herbaceous plants that can be adapted into changeable environmental conditions on a shallow substrate layer, require minimal maintenance, installed for their benefits to building and urban scale. Main objective of this study is to determine the characteristics of a green roof such as thermal insulation, water holding capacity, runoff characteristics, plant growth and its interaction with environmental factors in Istanbul climate conditions by performing comparative measurements. In this study, a research site (IU Green Roof Research Station was founded to assess water and energy balance of green roofs. Thus, a typical green roof was evaluated in terms of water and energy balance and its interaction with the building and city was determined. energy efficiency of green roof system was 77% higher than reference roof. Temperature fluctuations on green roof section of the roof were 79% lower. In addition, green roof retained 12,8% - 100% of precipitation and delayed runoff up to 23 hours depending on water content of substrate.

  9. A Virtual Reality-Cycling Training System for Lower Limb Balance Improvement.

    Science.gov (United States)

    Yin, Chieh; Hsueh, Ya-Hsin; Yeh, Chun-Yu; Lo, Hsin-Chang; Lan, Yi-Ting

    2016-01-01

    Stroke survivors might lose their walking and balancing abilities, but many studies pointed out that cycling is an effective means for lower limb rehabilitation. However, during cycle training, the unaffected limb tends to compensate for the affected one, which resulted in suboptimal rehabilitation. To address this issue, we present a Virtual Reality-Cycling Training System (VRCTS), which senses the cycling force and speed in real-time, analyzes the acquired data to produce feedback to patients with a controllable VR car in a VR rehabilitation program, and thus specifically trains the affected side. The aim of the study was to verify the functionality of the VRCTS and to verify the results from the ten stroke patients participants and to compare the result of Asymmetry Ratio Index (ARI) between the experimental group and the control group, after their training, by using the bilateral pedal force and force plate to determine any training effect. The results showed that after the VRCTS training in bilateral pedal force it had improved by 0.22 (p = 0.046) and in force plate the stand balance has also improved by 0.29 (p = 0.031); thus both methods show the significant difference.

  10. Evaluation of postural balance in mild cognitive impairment through a three-dimensional electromagnetic system.

    Science.gov (United States)

    Borges, Ana Paula Oliveira; Carneiro, José Ailton Oliveira; Zaia, José Eduardo; Carneiro, Antonio Adilton Oliveira; Takayanagui, Osvaldo Massaiti

    2016-01-01

    Elderly people with cognitive impairment are at greater risk for falls; thus, an understanding of the earliest stages of cognitive decline is necessary. To compare postural balance between elderly people with and without mild cognitive impairment using a three-dimensional system. Thirty elderly people with mild cognitive impairment and thirty healthy elderly subjects were selected. Static posturography was performed using three-dimensional electromagnetic equipment and the following parameters were evaluated: maximum displacement, mean speed and total trajectory. Open- and closed-eye stabilometric variable comparisons between groups and within each group were carried out, and a relationship between the Mini Mental State Examination and the total trajectory of all elderly subjects was determined. The analysis among open- and closed-eye conditions showed a significant difference in maximum anteroposterior displacement in the control group and a significant difference in all stabilometric variables in the mild cognitive impairment group. A significant difference between the groups in all variables in the closed-eye condition was observed. There was a strong correlation between cognitive performance and total trajectory. Evaluations showed decrease in balance in elderly people with mild cognitive impairment. Presence of anteroposterior displacement can be an early sign of postural control impairment, and the evaluation with visual restriction can be useful in detecting small postural instabilities. Copyright © 2015 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  11. Fresh water balance of the Gulf Stream system in a regional model study

    Energy Technology Data Exchange (ETDEWEB)

    Gerdes, R. [Alfred-Wegener-Institut fuer Polar- und Meeresforschung, Bremerhaven (Germany); Biastoch, A. [California Univ., San Diego, La Jolla, CA (United States). Scripps Inst. of Oceanography; Redler, R. [SCAI Inst. for Algorithms and Scientific Computing, German National Research Center for Information Technology, Sankt Augustin (Germany)

    2001-11-01

    We investigate the dependence of surface fresh water fluxes in the Gulf Stream and North Atlantic Current (NAC) area on the position of the stream axis which is not well represented in most ocean models. To correct this shortcoming, strong unrealistic surface fresh water fluxes have to be applied that lead to an incorrect salt balance of the current system. The unrealistic surface fluxes required by the oceanic component may force flux adjustments and may cause fictitious long-term variability in coupled climate models. To identify the important points in the correct representation of the salt balance of the Gulf Stream a regional model of the northwestern part of the subtropical gyre has been set up. Sensitivity studies are made where the westward flow north of the Gulf Stream and its properties are varied. Increasing westward volume transport leads to a southward migration of the Gulf Stream separation point along the American coast. The salinity of the inflow is essential for realistic surface fresh water fluxes and the water mass distribution. The subpolar-subtropical connection is important in two ways: The deep dense flow from the deep water mass formation areas sets up the cyclonic circulation cell north of the Gulf Stream. The surface and mid depth flow of fresh water collected at high northern latitudes is mixed into the Gulf Stream and compensates for the net evaporation at the surface. (orig.)

  12. ANALYSIS OF THE HARMONIC LOSSES WITH ARTIFICIAL NEURAL NETWORKS IN UNBALANCED SYSTEM LOSSES USING BALANCED ELECTRIC POWER SYSTEM DATA

    Directory of Open Access Journals (Sweden)

    Aslan İNAN

    2005-01-01

    Full Text Available The losses in the power systems should be low as possible as. Saving energy instead of loses (kWh in power utilities can supply much more energy to the consumers. The lower losses the more energy is saved and thus the power system becomes more economical. In recent years, the increasing number of applications and power ratings of the devices which have nonlinear voltage-current characteristics cause voltage waveform distortion and additional losses. While evaluating losses considering harmonics will provide more contribution to obtain more accurate results. In this study, Artificial Neural Networks (ANN method has been presented to predict the harmonic losses in unbalanced power systems by using the data from balanced power system with nonlinear loads.

  13. Hydrodynamics of the Dirac spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yizhuang, E-mail: yizhuang.liu@stonybrook.edu [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794-3800 (United States); Warchoł, Piotr, E-mail: piotr.warchol@uj.edu.pl [M. Smoluchowski Institute of Physics, Jagiellonian University, PL-30348 Krakow (Poland); Zahed, Ismail, E-mail: ismail.zahed@stonybrook.edu [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794-3800 (United States)

    2016-02-10

    We discuss a hydrodynamical description of the eigenvalues of the Dirac spectrum in even dimensions in the vacuum and in the large N (volume) limit. The linearized hydrodynamics supports sound waves. The hydrodynamical relaxation of the eigenvalues is captured by a hydrodynamical (tunneling) minimum configuration which follows from a pertinent form of Euler equation. The relaxation from a phase of unbroken chiral symmetry to a phase of broken chiral symmetry occurs over a time set by the speed of sound.

  14. Energy balance of five fodder cropping systems in the irrigated lowlands of Northern Italy

    Directory of Open Access Journals (Sweden)

    Cesare Tomasoni

    2011-03-01

    Full Text Available Extensification has recently become an important option in Western European agriculture, driven both by economic considerations (product surpluses together with the fact that developed countries cropping systems have been heavily relying on fossil energy and growing public concern on the possible adverse effects of intensive farming on the environment and human health. The adoption of rational fodder crop rotations, with the rediscovery of the beneficial effect of the meadow, is viewed as a possible mean to reduce the impact of farming systems in the lowlands of Northern Italy, characterised by highly intensive cropping and animal husbandry. For this reason our study examines the effects of crop rotation on the energy balance during 1985-2007 period in a long-term crop rotation trial in Northern Italy comparing five fodder crop systems, different in the degree of crop intensification and for the presence or absence of the meadow: a 1-year continuous cereal double cropping (R1; a 3-year rotation (R3; a 6-year rotation (R6; a permanent meadow (PM; and a continuous grain maize cropping (CM. Each rotation was subjected to two input treatments, defined as high (mostly used in lowlands of northern Italy and low (input reduction of ca. 30% respectively, in terms of nutrient levels, herbicide doses, and soil tillage methods. The crop rotations exerted a marked influence on the energy balance. The most efficient rotations in terms of net energy production energy efficiency have been characterized by reduced length and presence of maize and catch-crops.

  15. Fertilizer {sup 15}N balance in a coffee cropping system: a case study in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Fenilli, Tatiele Anete Bergamo [Universidade Regional de Blumenau (URB), SC (Brazil). Dept. de Engenharia Florestal]. E-mail: tfenilli@furb.br; Reichardt, Klaus; Bacchi, Osny Oliveira Santos [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil). Lab. de Fisica do Solo]. E-mails: klaus@cena.usp.br; osny@cena.usp.br; Favarin, Jose Laercio [Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP), Piracicaba, SP (Brazil). Dept. de Producao Vegetal; Silva, Adriana Lucia [Centro de Tecnologia Canavieira (CTC), Piracicaba, SP (Brazil). Fazenda Santo Antonio]. E-mail: adriana.silva@ctc.com.br; Timm, Luis Carlos [Universidade Federal de Pelotas (UFPel), RS (Brazil). Dept. de Engenharia Rural]. E-mail: lcartimm@yahoo.com.br

    2008-07-15

    Knowledge about the fate of fertilizer nitrogen in agricultural systems is essential for the improvement of management practices in order to maximize nitrogen (N) recovery by the crop and reduce N losses from the system to a minimum. This study involves fertilizer management practices using the {sup 15}N isotope label applied in a single rate to determine the fertilizer-N balance in a particular soil-coffee-atmosphere system and to deepen the understanding of N plant dynamics. Five replicates consisting of plots of about 120 plants each were randomly defined within a 0.2 ha coffee plantation planted in 2001, in Piracicaba, SP, Brazil. Nine plants of each plot were separated in sub-plots for the {sup 15}N balance studies and treated with N rates of 280 and 350 kg ha-1 during 2003/2004 and 2004/ 2005, respectively, both of them as ammonium sulfate enriched to a {sup 15}N abundance of 2.072 atom %. Plant shoots were considered as separate parts: the orthotropic central branch, productive branches, leaves of productive branches, vegetative branches, leaves of vegetative branches and fruit. Litter, consisting of dead leaves accumulated below the plant canopy, was measured by the difference between leaves at harvest and at the beginning of the following flowering. Roots and soil were sampled down to a depth of 1.0 at intervals of 0.2 m. Samples from the isotopic sub-plots were used to evaluate total N and {sup 15}N, and plants outside sub-plots were used to evaluate dry matter. Volatilization losses of NH{sub 3} were estimated using special collectors. Leaching of fertilizer-N was estimated from deep drainage water fluxes and {sup 15}N concentrations of the soil solution at 1 m soil depth. At the end of the 2-year evaluation, the recovery of {sup 15}N applied as ammonium sulfate was 19.1 % in aerial plant parts, 9.4 % in the roots, 23.8 % in the litter, 26.3 % in the fruit and 12.6 % remaining in the 0-1.0 m soil profile. Annual leaching and volatilization losses were

  16. FatFS的水动力实验数据存储系统设计%Data Storage Module Based on FatFS System for Hydrodynamic Experiment

    Institute of Scientific and Technical Information of China (English)

    丁力; 宋志平; 徐萌萌; 陶灿辉

    2013-01-01

    Aiming at the problem of data concentration and huge amount in the experimental study of the hydrodynamic, an SD card storage system based on FatFS file system is proposed. The system takes STM32F103ZET6 as core, and a large number of data file storage is achieved through SDIO interfaces. The system's USB module and RTC module of hardware design are described in detail, then the transplanting FatFS file system on the system is discussed, and at last the FatFS File read and write functions are achieved on SD card. The system has high transmission speed and high reliability performance, it has broad application.%针对在水动力实验研究中数据量集中、数量多的问题,提出了一种基于FatFS文件系统的SD卡存储系统设计方案.该系统以ST公司的STM32F103ZET6为核心,通过SDIO接口实现大量数据文件存储.详细讲解了系统的USB模块、RTC模块等硬件设计,探讨了在系统上移植FatFS文件系统的要点,并在SD卡上实现了FAT文件的读写功能.该系统传输速度快、可靠性强,具有一定的应用价值.

  17. Feasibility of a Low-Cost, Interactive Gaming System to Assess Balance in Older Women.

    Science.gov (United States)

    Hall, Courtney D; Clevenger, Carolyn K; Wolf, Rachel A; Lin, James S; Johnson, Theodore M; Wolf, Steven L

    2016-01-01

    The use of low-cost interactive game technology for balance rehabilitation has become more popular recently, with generally good outcomes. Very little research has been undertaken to determine whether this technology is appropriate for balance assessment. The Wii balance board has good reliability and is comparable to a research-grade force plate; however, recent studies examining the relationship between Wii Fit games and measures of balance and mobility demonstrate conflicting findings. This study found that the Wii Fit was feasible for community-dwelling older women to safely use the balance board and quickly learn the Wii Fit games. The Ski Slalom game scores were strongly correlated with several balance and mobility measures, whereas Table Tilt game scores were not. Based on these findings, the Ski Slalom game may have utility in the evaluation of balance problems in community-dwelling older adults.

  18. Combining pathway analysis with flux balance analysis for the comprehensive study of metabolic systems.

    Science.gov (United States)

    Schilling, C H; Edwards, J S; Letscher, D; Palsson, B Ø

    The elucidation of organism-scale metabolic networks necessitates the development of integrative methods to analyze and interpret the systemic properties of cellular metabolism. A shift in emphasis from single metabolic reactions to systemically defined pathways is one consequence of such an integrative analysis of metabolic systems. The constraints of systemic stoichiometry, and limited thermodynamics have led to the definition of the flux space within the context of convex analysis. The flux space of the metabolic system, containing all allowable flux distributions, is constrained to a convex polyhedral cone in a high-dimensional space. From metabolic pathway analysis, the edges of the high-dimensional flux cone are vectors that correspond to systemically defined "extreme pathways" spanning the capabilities of the system. The addition of maximum flux capacities of individual metabolic reactions serves to further constrain the flux space and has led to the development of flux balance analysis using linear optimization to calculate optimal flux distributions. Here we provide the precise theoretical connections between pathway analysis and flux balance analysis allowing for their combined application to study integrated metabolic function. Shifts in metabolic behavior are calculated using linear optimization and are then interpreted using the extreme pathways to demonstrate the concept of pathway utilization. Changes to the reaction network, such as the removal of a reaction, can lead to the generation of suboptimal phenotypes that can be directly attributed to the loss of pathway function and capabilities. Optimal growth phenotypes are calculated as a function of environmental variables, such as the availability of substrate and oxygen, leading to the definition of phenotypic phase planes. It is illustrated how optimality properties of the computed flux distributions can be interpreted in terms of the extreme pathways. Together these developments are applied to an

  19. Anisotropic hydrodynamics for conformal Gubser flow

    Energy Technology Data Exchange (ETDEWEB)

    Strickland, Michael; Nopoush, Mohammad [Kent State University, Kent OH 44242 (United States); Ryblewski, Radoslaw [The H. Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences, PL-31342 Kraków (Poland)

    2016-12-15

    In this proceedings contribution, we review the exact solution of the anisotropic hydrodynamics equations for a system subject to Gubser flow. For this purpose, we use the leading-order anisotropic hydrodynamics equations which assume that the distribution function is ellipsoidally symmetric in local-rest-frame momentum. We then prove that the SO(3){sub q} symmetry in de Sitter space constrains the anisotropy tensor to be of spheroidal form with only one independent anisotropy parameter remaining. As a consequence, the exact solution reduces to the problem of solving two coupled non-linear differential equations. We show that, in the limit that the relaxation time goes to zero, one obtains Gubser's ideal hydrodynamic solution and, in the limit that the relaxation time goes to infinity, one obtains the exact free streaming solution obtained originally by Denicol et al. For finite relaxation time, we solve the equations numerically and compare to the exact solution of the relaxation-time-approximation Boltzmann equation subject to Gubser flow. Using this as our standard, we find that anisotropic hydrodynamics describes the spatio-temporal evolution of the system better than all currently known dissipative hydrodynamics approaches.

  20. Balanced Scorecard - a successful system. Integrated company management improves capability to be competitive; Balanced Scorecard - mit System zum Erfolg. Integrierte Unternehmenssteuerung verbessert Wettbewerbsfaehigkeit

    Energy Technology Data Exchange (ETDEWEB)

    Ahrend, M. [Andersen Consulting Unternehmensberatung GmbH, Muenchen (Germany); Weinrauch, M. [Andersen Consulting Unternehmensberatung GmbH, Sulzbach (Germany); Franke, V. [Andersen Consulting Unternehmensberatung GmbH, Duesseldorf (Germany)

    2000-09-18

    Balanced Scorecard is more than a reporting instrument for company management. Behind this you will find much more an integrated and already proven methodology to improve on a longterm basis the capability to be competitive. Companies in the sector of supplying economy, which are facing new challenges after the liberalization of the energy market, are in need of intelligent programmes in order to maintain on the competitive market. Balanced Scorecard combines classical financial means of control with customer- and market reference numbers as well as information on the process navigation and staff management. It links strategy planning and the strategy targets of a utility with its operational business. (orig.) [German] Balanced Scorecard ist mehr als ein Reporting-Instrument fuer das Unternehmensmanagement. Dahinter verbirgt sich vielmehr eine integrierte und bereits bewaehrte Methodik zur nachhaltigen Verbesserung der Wettbewerbsfaehigkeit. Unternehmen der Versorgungswirtschaft, die nach der Liberalisierung des Energiemarkts vor neuen Herausforderungen stehen, beduerfen intelligenter Konzepte, um sich im Wettbewerb behaupten zu koennen. Die Balanced Scorecard verknuepft klassische finanzielle Steuerungsgroessen mit Kunden- und Marktkennzahlen sowie Informationen der Prozesssteuerung und Mitarbeiterfuehrung. Mit ihr gelingt es, die oft bestehende Luecke zwischen strategischen Zielen und operativen Massnahmen zu schliessen. (orig.)

  1. Global classical solutions for partially dissipative hyperbolic system of balance laws

    CERN Document Server

    Xu, Jiang

    2012-01-01

    This work is concerned with ($N$-component) hyperbolic system of balance laws in arbitrary space dimensions. Under entropy dissipative assumption and the Shizuta-Kawashima algebraic condition, a general theory on the well-posedness of classical solutions in the framework of Chemin-Lerner's spaces with critical regularity is established. To do this, we first explore the functional space theory and develop an elementary fact that indicates the relation between homogeneous and inhomogeneous Chemin-Lerner's spaces. Then this fact allows to prove the local well-posedness for general data and global well-posedness for small data by using the Fourier frequency-localization argument. Finally, we apply the new existence theory to a specific fluid model-the compressible Euler equations with damping, and obtain the corresponding results in critical spaces.

  2. Health technology assessment in the Balkans: opportunities for a balanced drug assessment system.

    Science.gov (United States)

    Dankó, Dávid; Petrova, Guenka

    2014-11-02

    Countries in the Balkan region use pharmaco-economic data for decisions about the inclusion of new pharmaceuticals into their positive drug lists, but no predefined frameworks are used and resources for health technology assessment (HTA) are limited. The goal of this analysis is to investigate into possible development directions for the HTA system in the region, and provide some practical recommendations for a sustainable model. For this purpose, the main factors currently influencing HTA in Balkan countries are briefly presented, and possible development strategies are compared. A resource-saving balanced assessment approach is proposed. It is aligned with available resources and capabilities, and helps access to new pharmaceuticals while ensuring the transparency of decision-making processes and the stability of the pharmaceutical budget.

  3. Low complexity transmit antenna selection with power balancing in OFDM systems

    KAUST Repository

    Park, Kihong

    2010-10-01

    In this paper, we consider multi-carrier systems with multiple transmit antennas under the power balancing constraint, which is defined as the constraint that the power on each antenna should be limited under a certain level due to the linearity of the power amplifier of the RF chain. Applying transmit antenna selection and fixed-power variable-rate transmission per subcarrier as a function of channel variations, we propose an implementation-friendly antenna selection method which offers a reduced complexity in comparison with the optimal antenna selection scheme. More specifically, in order to solve the subcarrier imbalance across the antennas, we operate a two-step reallocation procedure to minimize the loss of spectral efficiency. We also provide an analytic lower bound on the spectral efficiency for the proposed scheme. From selected numerical results, we show that our suboptimal scheme offers almost the same spectral efficiency as the optimal one. © 2010 IEEE.

  4. Ponce de Leon Inlet, FL: An Integrated Hydrodynamic and Morphologic Assessment of Design Alternatives using the U.S. Army Corps of Engineers’ Coastal Modeling System

    Science.gov (United States)

    2009-07-01

    Ponce de Leon Inlet, FL: An Integrated Hydrodynamic and Morphologic Assessment of Design Alternatives using the U.S. Army Corps of Engineers...DATES COVERED - 4. TITLE AND SUBTITLE Ponce de Leon Inlet, FL: An Integrated Hydrodynamic and Morphologic Assessment of Design Alternatives...SUPPLEMENTARY NOTES 14. ABSTRACT Shoaling and channel migration at Ponce de Leon Inlet, FL, have caused persistently hazardous navigation conditions

  5. Setup time reduction: SMED-balancing integrated model for manufacturing systems with automated transfer

    Directory of Open Access Journals (Sweden)

    Maurizio Faccio

    2013-10-01

    Full Text Available The importance of short setup times is increasing in every type of industry. It has been known how to address this problem for about 20 years. The SMED method, originally developed by the Japanese industrial engineer Shigeo Shingo for reducing the time to exchange dies, gives a really straightforward approach to improve existing setups. On the other hand, in the case of complex manufacturing systems the simple application of the SMED methodology is not enough. Manufacturing systems composed of different working machines with automated transfer facilities are a good example. Technologicalconstraints, task precedence constraints, and synchronization between different setup tasks are just some of the influencing factors that make an improved SMED desirable. The present paper, starting from an industrial case, aims to provide a heuristics methodology that integrates the traditional SMED with the workload balancing problem that is typical of assembly systems, in order to address the setup reduction problem in the case of complex manufacturing systems. Anindustrial case is reported to validate the proposed model and to demonstrate its practical implications.

  6. Toward a workable biosafety system for regulating genetically modified organisms in Ethiopia: balancing conservation and competitiveness.

    Science.gov (United States)

    Abraham, Adane

    2013-01-01

    On September 9, 2009, Ethiopia enacted a highly restrictive biosafety law firmly based on precautionary principles as a foundation for its GMO regulation system. Its drafting process, led by the country's Environmental Protection Authority, was judged as biased, focusing only on protecting the environment from perceived risks, giving little attention to potential benefits of GMOs. Many of its provisions are very stringent, exceeding those of Cartagena Protocol on Biosafety, while others cannot be fulfilled by applicants, collectively rendering the emerged biosafety system unworkable. These provisions include requirements for advance informed agreement and rigorous socioeconomic assessment in risk evaluation for all GMO transactions, including contained research use-which requires the head of the competent national authority of the exporting country to take full responsibility for GMO-related information provided-and stringent labeling, insurance and monitoring requirements for all GMO activities. Furthermore, there is no provision to establish an independent national biosafety decision-making body(ies). As a result, foreign technology owners that provide highly demanded technologies like Bt cotton declined to work with Ethiopia. There is a fear that the emerged biosafety system might also continue to suppress domestic genetic engineering research and development. Thus, to benefit from GMOs, Ethiopia has to revise its biosafety system, primarily by making changes to some provisions of the law in a way that balances its diverse interests of conserving biodiversity, protecting the environment and enhancing competition in agricultural and other economic sectors.

  7. Results of monitoring large carbon fiber post-tensioning systems in a balanced Cantilever Brdige (Dintelharbour Bridge, The Netherlands)

    NARCIS (Netherlands)

    Vervuurt, A.H.J.M.; Kaptijn, N.; Hageman, J.G.; Kuilboer, C.P.M.

    2012-01-01

    Steel post-tensioning systems and stay cables are susceptible to corrosion. Carbon fiber systems are not. However, there was no experience on the long term behavior of such post-tensioned elements. Four external tendons (75 m long), stressed to a load of 2650 kN, were applied in a large balanced can

  8. Results of monitoring large carbon fiber post-tensioning systems in a balanced Cantilever Brdige (Dintelharbour Bridge, The Netherlands)

    NARCIS (Netherlands)

    Vervuurt, A.H.J.M.; Kaptijn, N.; Hageman, J.G.; Kuilboer, C.P.M.

    2012-01-01

    Steel post-tensioning systems and stay cables are susceptible to corrosion. Carbon fiber systems are not. However, there was no experience on the long term behavior of such post-tensioned elements. Four external tendons (75 m long), stressed to a load of 2650 kN, were applied in a large balanced

  9. The emerging role of the endocannabinoid system in endocrine regulation and energy balance.

    Science.gov (United States)

    Pagotto, Uberto; Marsicano, Giovanni; Cota, Daniela; Lutz, Beat; Pasquali, Renato

    2006-02-01

    During the last few years, the endocannabinoid system has emerged as a highly relevant topic in the scientific community. Many different regulatory actions have been attributed to endocannabinoids, and their involvement in several pathophysiological conditions is under intense scrutiny. Cannabinoid receptors, named CB1 receptor and CB2 receptor, first discovered as the molecular targets of the psychotropic component of the plant Cannabis sativa, participate in the physiological modulation of many central and peripheral functions. CB2 receptor is mainly expressed in immune cells, whereas CB1 receptor is the most abundant G protein-coupled receptor expressed in the brain. CB1 receptor is expressed in the hypothalamus and the pituitary gland, and its activation is known to modulate all the endocrine hypothalamic-peripheral endocrine axes. An increasing amount of data highlights the role of the system in the stress response by influencing the hypothalamic-pituitary-adrenal axis and in the control of reproduction by modifying gonadotropin release, fertility, and sexual behavior. The ability of the endocannabinoid system to control appetite, food intake, and energy balance has recently received great attention, particularly in the light of the different modes of action underlying these functions. The endocannabinoid system modulates rewarding properties of food by acting at specific mesolimbic areas in the brain. In the hypothalamus, CB1 receptor and endocannabinoids are integrated components of the networks controlling appetite and food intake. Interestingly, the endocannabinoid system was recently shown to control metabolic functions by acting on peripheral tissues, such as adipocytes, hepatocytes, the gastrointestinal tract, and, possibly, skeletal muscle. The relevance of the system is further strenghtened by the notion that drugs interfering with the activity of the endocannabinoid system are considered as promising candidates for the treatment of various diseases

  10. The functional assessment Berg Balance Scale is better capable of estimating fall risk in the elderly than the posturographic Balance Stability System A avaliação funcional Berg Balance Scale é capaz de estimar melhor o risco de quedas em idosos do que a posturografia Balance Stability System

    Directory of Open Access Journals (Sweden)

    Vanessa Vieira Pereira

    2013-01-01

    Full Text Available The purpose of this study was to verify which instrument better identifies recurrent falls in the elderly. Ninety-eight old people, with an average age of 80±4 years, were submitted to an assessment of balance and fall risk by means of the Berg Balance Scale (BBS and the posturographic Balance Stability System (BSS. The BBS was correlated with the BSS (r=-0.27; p=0.008, age (r=-0.38; pA proposta do estudo foi verificar o instrumento que melhor identifica o risco de quedas recorrentes em idosos. O estudo incluiu 98 idosos, com média de idade de 80±4 anos, submetidos à avaliação do equilíbrio e risco de quedas por meio da Berg Balance Scale (BBS e da posturografia Balance Stability System (BSS. A BBS foi correlacionada com a BSS (r=-0,27; p=0,008, com a idade (r=-0,38; p<0,001 e com o número de quedas (r=-0,25; p=0,013. A análise de regressão logística mostrou que idosos classificados com risco de quedas na BBS apresentaram 2,5 (95%IC 1,08-5,78 mais chances de identificar quem teve duas quedas ou mais no último ano. A BBS identificou que quanto maior a idade pior é o equilíbrio funcional e demonstrou maior capacidade de identificar o risco de quedas sofridas no último ano quando comparada a BSS.

  11. Scalability of Hydrodynamic Simulations

    CERN Document Server

    Tang, Shikui

    2009-01-01

    Many hydrodynamic processes can be studied in a way that is scalable over a vastly relevant physical parameter space. We systematically examine this scalability, which has so far only briefly discussed in astrophysical literature. We show how the scalability is limited by various constraints imposed by physical processes and initial conditions. Using supernova remnants in different environments and evolutionary phases as application examples, we demonstrate the use of the scaling as a powerful tool to explore the interdependence among relevant parameters, based on a minimum set of simulations. In particular, we devise a scaling scheme that can be used to adaptively generate numerous seed remnants and plant them into 3D hydrodynamic simulations of the supernova-dominated interstellar medium.

  12. Relativistic Hydrodynamics with Wavelets

    CERN Document Server

    DeBuhr, Jackson; Anderson, Matthew; Neilsen, David; Hirschmann, Eric W

    2015-01-01

    Methods to solve the relativistic hydrodynamic equations are a key computational kernel in a large number of astrophysics simulations and are crucial to understanding the electromagnetic signals that originate from the merger of astrophysical compact objects. Because of the many physical length scales present when simulating such mergers, these methods must be highly adaptive and capable of automatically resolving numerous localized features and instabilities that emerge throughout the computational domain across many temporal scales. While this has been historically accomplished with adaptive mesh refinement (AMR) based methods, alternatives based on wavelet bases and the wavelet transformation have recently achieved significant success in adaptive representation for advanced engineering applications. This work presents a new method for the integration of the relativistic hydrodynamic equations using iterated interpolating wavelets and introduces a highly adaptive implementation for multidimensional simulati...

  13. Problems of application of the balanced system of indicators on domestic enterprises

    Directory of Open Access Journals (Sweden)

    O.S. Savchenko

    2011-01-01

    Full Text Available The article is dedicated to theoretical and methodical basics of the implementation of Balanced Scorecard in business organization. There were fundamental problems, advantages and disadvantages defined by the authors; methodical approaches to the choice of strategies and stages of formation and introduction of Balanced Scorecard analyzed; essential principles of development of key performance indicators for building-up of Balanced Scorecard formulated.

  14. Relativistic cosmological hydrodynamics

    CERN Document Server

    Hwang, J

    1997-01-01

    We investigate the relativistic cosmological hydrodynamic perturbations. We present the general large scale solutions of the perturbation variables valid for the general sign of three space curvature, the cosmological constant, and generally evolving background equation of state. The large scale evolution is characterized by a conserved gauge invariant quantity which is the same as a perturbed potential (or three-space curvature) in the comoving gauge.

  15. Uplink Downlink Rate Balancing and Throughput Scaling in FDD Massive MIMO Systems

    Science.gov (United States)

    Bergel, Itsik; Perets, Yona; Shamai, Shlomo

    2016-05-01

    In this work we extend the concept of uplink-downlink rate balancing to frequency division duplex (FDD) massive MIMO systems. We consider a base station with large number antennas serving many single antenna users. We first show that any unused capacity in the uplink can be traded off for higher throughput in the downlink in a system that uses either dirty paper (DP) coding or linear zero-forcing (ZF) precoding. We then also study the scaling of the system throughput with the number of antennas in cases of linear Beamforming (BF) Precoding, ZF Precoding, and DP coding. We show that the downlink throughput is proportional to the logarithm of the number of antennas. While, this logarithmic scaling is lower than the linear scaling of the rate in the uplink, it can still bring significant throughput gains. For example, we demonstrate through analysis and simulation that increasing the number of antennas from 4 to 128 will increase the throughput by more than a factor of 5. We also show that a logarithmic scaling of downlink throughput as a function of the number of receive antennas can be achieved even when the number of transmit antennas only increases logarithmically with the number of receive antennas.

  16. Autonomic Nervous System in the Control of Energy Balance and Body Weight: Personal Contributions

    Directory of Open Access Journals (Sweden)

    G. Messina

    2013-01-01

    Full Text Available The prevalence of obesity is increasing in the industrialized world, so that the World Health Organization considers obesity as a “pandemia” in rich populations. The autonomic nervous system plays a crucial role in the control of energy balance and body weight. This review summarizes our own data and perspectives, emphasizing the influence exerted by autonomic nervous system on energy expenditure and food intake, which are able to determine the body weight. Activation of the sympathetic discharge causes an increase in energy expenditure and a decrease in food intake, while reduction of food intake and body weight loss determines a reduction of the sympathetic activity. On the other hand, pathophysiological mechanisms of the obesity involve alterations of the sympathetic nervous system in accordance with the “Mona Lisa Hypothesis,” an acronym for “most obesities known are low in sympathetic activity.” Furthermore, the parasympathetic influences on the energy expenditure are analyzed in this review, showing that an increase in parasympathetic activity can induce a paradoxical enhancement of energy consumption.

  17. Autonomic nervous system in the control of energy balance and body weight: personal contributions.

    Science.gov (United States)

    Messina, G; De Luca, V; Viggiano, An; Ascione, A; Iannaccone, T; Chieffi, S; Monda, M

    2013-01-01

    The prevalence of obesity is increasing in the industrialized world, so that the World Health Organization considers obesity as a "pandemia" in rich populations. The autonomic nervous system plays a crucial role in the control of energy balance and body weight. This review summarizes our own data and perspectives, emphasizing the influence exerted by autonomic nervous system on energy expenditure and food intake, which are able to determine the body weight. Activation of the sympathetic discharge causes an increase in energy expenditure and a decrease in food intake, while reduction of food intake and body weight loss determines a reduction of the sympathetic activity. On the other hand, pathophysiological mechanisms of the obesity involve alterations of the sympathetic nervous system in accordance with the "Mona Lisa Hypothesis," an acronym for "most obesities known are low in sympathetic activity." Furthermore, the parasympathetic influences on the energy expenditure are analyzed in this review, showing that an increase in parasympathetic activity can induce a paradoxical enhancement of energy consumption.

  18. Configuring balanced scorecards for measuring health system performance: evidence from 5 years' evaluation in Afghanistan.

    Science.gov (United States)

    Edward, Anbrasi; Kumar, Binay; Kakar, Faizullah; Salehi, Ahmad Shah; Burnham, Gilbert; Peters, David H

    2011-07-01

    In 2004, Afghanistan pioneered a balanced scorecard (BSC) performance system to manage the delivery of primary health care services. This study examines the trends of 29 key performance indicators over a 5-year period between 2004 and 2008. Independent evaluations of performance in six domains were conducted annually through 5,500 patient observations and exit interviews and 1,500 provider interviews in >600 facilities selected by stratified random sampling in each province. Generalized estimating equation (GEE) models were used to assess trends in BSC parameters. There was a progressive improvement in the national median scores scaled from 0-100 between 2004 and 2008 in all six domains: patient and community satisfaction of services (65.3-84.5, pperformance benchmarking during the 5-year period. However, scorecard reconfigurations are needed to integrate effectiveness and efficiency measures and accommodate changes in health systems policy and strategy architecture to ensure its continued relevance and effectiveness as a comprehensive health system performance measure. The process of BSC design and implementation can serve as a valuable prototype for health policy planners managing performance in similar health care contexts. Please see later in the article for the Editors' Summary.

  19. A nonlinearity in permanent-magnet systems used in watt balances

    CERN Document Server

    Li, Shisong; Pratt, Jon

    2014-01-01

    Watt balances are used to measure the Planck constant and will be used in the future to realize mass at the kilogram level. They increasingly rely on permanent magnet systems to generate the magnetic flux. It has been known that the weighing current might effect the magnetization state of the permanent magnetic system used in these systems causing a systematic bias that can lead to an error in the result if not accounted for. In this article a simple model explaining the effect of the weighing current on the yoke of the magnet is developed. This model leads to a nonlinear dependence of the magnetic flux density in the gap that is proportional to the squared value of the coil current. The effect arises from changing the reluctance of the yoke by the additional field produced by the coil. Our analysis shows that the effect depends on the width of the air gap, the magnetic flux density in the air gap, and the $BH$ curve of the yoke material. Suggestions to reduce the nonlinear effect are discussed.

  20. Configuring Balanced Scorecards for Measuring Health System Performance: Evidence from 5 Years' Evaluation in Afghanistan

    Science.gov (United States)

    Edward, Anbrasi; Kumar, Binay; Kakar, Faizullah; Salehi, Ahmad Shah; Burnham, Gilbert; Peters, David H.

    2011-01-01

    Background In 2004, Afghanistan pioneered a balanced scorecard (BSC) performance system to manage the delivery of primary health care services. This study examines the trends of 29 key performance indicators over a 5-year period between 2004 and 2008. Methods and Findings Independent evaluations of performance in six domains were conducted annually through 5,500 patient observations and exit interviews and 1,500 provider interviews in >600 facilities selected by stratified random sampling in each province. Generalized estimating equation (GEE) models were used to assess trends in BSC parameters. There was a progressive improvement in the national median scores scaled from 0–100 between 2004 and 2008 in all six domains: patient and community satisfaction of services (65.3–84.5, pperformance benchmarking during the 5-year period. However, scorecard reconfigurations are needed to integrate effectiveness and efficiency measures and accommodate changes in health systems policy and strategy architecture to ensure its continued relevance and effectiveness as a comprehensive health system performance measure. The process of BSC design and implementation can serve as a valuable prototype for health policy planners managing performance in similar health care contexts. Please see later in the article for the Editors' Summary PMID:21814499

  1. BALANCED SCORECARDS EVALUATION MODEL THAT INCLUDES ELEMENTS OF ENVIRONMENTAL MANAGEMENT SYSTEM USING AHP MODEL

    Directory of Open Access Journals (Sweden)

    Jelena Jovanović

    2010-03-01

    Full Text Available The research is oriented on improvement of environmental management system (EMS using BSC (Balanced Scorecard model that presents strategic model of measurem ents and improvement of organisational performance. The research will present approach of objectives and environmental management me trics involvement (proposed by literature review in conventional BSC in "Ad Barska plovi dba" organisation. Further we will test creation of ECO-BSC model based on business activities of non-profit organisations in order to improve envir onmental management system in parallel with other systems of management. Using this approach we may obtain 4 models of BSC that includ es elements of environmen tal management system for AD "Barska plovidba". Taking into acc ount that implementation and evaluation need long period of time in AD "Barska plovidba", the final choice will be based on 14598 (Information technology - Software product evaluation and ISO 9126 (Software engineering - Product quality using AHP method. Those standards are usually used for evaluation of quality software product and computer programs that serve in organisation as support and factors for development. So, AHP model will be bas ed on evolution criteria based on suggestion of ISO 9126 standards and types of evaluation from two evaluation teams. Members of team & will be experts in BSC and environmental management system that are not em ployed in AD "Barska Plovidba" organisation. The members of team 2 will be managers of AD "Barska Plovidba" organisation (including manage rs from environmental department. Merging results based on previously cr eated two AHP models, one can obtain the most appropriate BSC that includes elements of environmental management system. The chosen model will present at the same time suggestion for approach choice including ecological metrics in conventional BSC model for firm that has at least one ECO strategic orientation.

  2. Hydrodynamics of insect spermatozoa

    Science.gov (United States)

    Pak, On Shun; Lauga, Eric

    2010-11-01

    Microorganism motility plays important roles in many biological processes including reproduction. Many microorganisms propel themselves by propagating traveling waves along their flagella. Depending on the species, propagation of planar waves (e.g. Ceratium) and helical waves (e.g. Trichomonas) were observed in eukaryotic flagellar motion, and hydrodynamic models for both were proposed in the past. However, the motility of insect spermatozoa remains largely unexplored. An interesting morphological feature of such cells, first observed in Tenebrio molitor and Bacillus rossius, is the double helical deformation pattern along the flagella, which is characterized by the presence of two superimposed helical flagellar waves (one with a large amplitude and low frequency, and the other with a small amplitude and high frequency). Here we present the first hydrodynamic investigation of the locomotion of insect spermatozoa. The swimming kinematics, trajectories and hydrodynamic efficiency of the swimmer are computed based on the prescribed double helical deformation pattern. We then compare our theoretical predictions with experimental measurements, and explore the dependence of the swimming performance on the geometric and dynamical parameters.

  3. Hydrodynamics of fossil fishes.

    Science.gov (United States)

    Fletcher, Thomas; Altringham, John; Peakall, Jeffrey; Wignall, Paul; Dorrell, Robert

    2014-08-07

    From their earliest origins, fishes have developed a suite of adaptations for locomotion in water, which determine performance and ultimately fitness. Even without data from behaviour, soft tissue and extant relatives, it is possible to infer a wealth of palaeobiological and palaeoecological information. As in extant species, aspects of gross morphology such as streamlining, fin position and tail type are optimized even in the earliest fishes, indicating similar life strategies have been present throughout their evolutionary history. As hydrodynamical studies become more sophisticated, increasingly complex fluid movement can be modelled, including vortex formation and boundary layer control. Drag-reducing riblets ornamenting the scales of fast-moving sharks have been subjected to particularly intense research, but this has not been extended to extinct forms. Riblets are a convergent adaptation seen in many Palaeozoic fishes, and probably served a similar hydrodynamic purpose. Conversely, structures which appear to increase skin friction may act as turbulisors, reducing overall drag while serving a protective function. Here, we examine the diverse adaptions that contribute to drag reduction in modern fishes and review the few attempts to elucidate the hydrodynamics of extinct forms.

  4. The Surface Energy Balance System(sebs) For Estimating Energy Balance At Regional Scale - A Validation Using Atsr and Scintillometer Measurements and Racmo Pbl Variables

    Science.gov (United States)

    Jia, L.; Su, Z.; van den Hurk, B.; Moene, A. F.; Menenti, M.

    The estimation of atmospheric turbulent fluxes at the land surface has long been rec- ognized as the most important process in the determination of the exchanges of energy and mass among hydrosphere, atmosphere and biosphere. Remote sensing is probably the only technique which can provide representative measurements of several relevant physical parameters at scales from a point to a continent. Techniques using remote sensing information to estimate atmospheric turbulent fluxes are therefore essential when dealing with processes that can not be represented only by point measurements. In this contribution the Surface Energy Balance System (SEBS) for the estimation of atmospheric turbulent fluxes using satellite earth observation data are evaluated with measurements of sensible heat fluxes by scintillometry. SEBS as proposed here consists of: 1) a set of tools for the determination of the land surface physical param- eters, such as albedo, emissivity, temperature, vegetation coverage etc. from spectral reflectance and radiance of ATSR-2 measurements; 2) an extended model for the de- termination of the roughness length for heat transfer; 3) and a new formulation for the determination of the evaporative fraction on the basis of energy balance at lim- iting cases. The input to SEBS are ATSR derived surface physical variables and at- mospheric boundary layer variables derived from the mesoscale atmospheric model RACMO. The SEBS estimates are satisfactory when evaluated over three different land surface areas with dry, small irrigated and larger irrigated surface situations re- spectively.

  5. The immediate effects of ankle balance taping with kinesiology tape on ankle active range of motion and performance in the Balance Error Scoring System.

    Science.gov (United States)

    Lee, Sun-Min; Lee, Jung-Hoon

    2017-05-01

    This study investigated the changes in ankle active range of motion (AROM) and performance on the Balance Error Scoring System (BESS) in cases in which no tape, placebo taping or ankle balance taping (ABT) with kinesiology tape was used. Randomized cross-over trial. University laboratory. Fifteen physically active individuals (7 men, 8 women). Postural control was assessed based on performances on the BESS. Active ankle flexibility was assessed by measuring the ankle AROM of both ankles under each taping condition in a random order at 1-week intervals. The ankle AROM among the taping conditions were not significantly different. There were no significant differences in the error scores of single-leg and tandem stances on a firm surface among the taping conditions. Compared to those obtained in the absence of taping, the error scores of the single-leg and tandem stances on a foam surface were significantly lower with ABT, but they did not significantly differ from the placebo taping scores. This study showed that ABT with kinesiology tape immediately improved postural control on unstable surfaces without changes in ankle AROM. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Linking Economic Value Added, Direct Costing, and the Lean Thinking to the Balanced Scorecard in a System Dynamics Modelling Approach

    DEFF Research Database (Denmark)

    Nielsen, Steen; Nielsen, Erland Hejn

     Purpose - To show how three practices normally applied separately can be linked to support the strategy evaluation and the performance measurement in the balanced scorecard. Recent studies, e.g. Kaplan and Norton [Using the Balanced Scorecard as a Strategic Management System, Harvard Business...... Review, July-August, 2007], provide evidence that companies fail to see the possible benefits of combining and integrating several accounting practices into a single framework. Design/methodology/approach - We use a System Dynamics Modelling approach to the BSC-thinking. The BSC model includes the five...

  7. Fish stocking density impacts tank hydrodynamics

    DEFF Research Database (Denmark)

    Rasmussen, Michael R.; Lunger, Angela; Laursen, Jesper;

    2006-01-01

    hydrodynamics was established using in-tank-based Rhodamine WT fluorometry at a flow rate of 0.23 l s-1 (tank exchange rate of 1.9 h-1). With increasing numbers of animals, curvilinear relationships were observed for dispersion coefficients and tank mixing times. Stocking densities of 3, 6, 9 and 12 kg m-3......The effect of stocking density upon the hydrodynamics of a circular tank, configured in a recirculation system, was investigated. Red drums Sciaenops ocellatus of approximately 140 g wet weight, were stocked at five rates varying from 0 to 12 kg m-3. The impact of the presence of fish upon tank...

  8. Supernova hydrodynamics experiments using the Nova laser

    Energy Technology Data Exchange (ETDEWEB)

    Remington, B.A.; Glendinning, S.G.; Estabrook, K.; Wallace, R.J.; Rubenchik, A. [Lawrence Livermore National Lab., CA (United States); Kane, J.; Arnett, D. [Arizona Univ., Tucson, AZ (United States). Stewart Observatory; Drake, R.P. [Michigan Univ., Ann Arbor, MI (United States); McCray, R. [Colorado Univ., Boulder, CO (United States)

    1997-04-01

    We are developing experiments using the Nova laser to investigate two areas of physics relevant to core-collapse supernovae (SN): (1) compressible nonlinear hydrodynamic mixing and (2) radiative shock hydrodynamics. In the former, we are examining the differences between the 2D and 3D evolution of the Rayleigh-Taylor instability, an issue critical to the observables emerging from SN in the first year after exploding. In the latter, we are investigating the evolution of a colliding plasma system relevant to the ejecta-stellar wind interactions of the early stages of SN remnant formation. The experiments and astrophysical implications are discussed.

  9. Hydrodynamics, resurgence and trans-asymptotics

    CERN Document Server

    Basar, Gokce

    2015-01-01

    The second-order hydrodynamical description of a homogeneous conformal plasma that undergoes a boost- invariant expansion is given by a single nonlinear ordinary differential equation, whose resurgent asymptotic properties we study, developing further the recent work of Heller and Spalinski [Phys. Rev. Lett. 115, 072501 (2015)]. Resurgence clearly identifies the non-hydrodynamic modes that are exponentially suppressed at late times, analogous to the quasi-normal-modes in gravitational language, organizing these modes in terms of a trans-series expansion. These modes are analogs of instantons in semi-classical expansions, where the damping rate plays the role of the instanton action. We show that this system displays the generic features of resurgence, with explicit quantitative relations between the fluctuations about different orders of these non-hydrodynamic modes. The imaginary part of the trans-series parameter is identified with the Stokes constant, and the real part with the freedom associated with init...

  10. The benefits of using a vacuum-assisted socket system to improve balance and gait in elderly transtibial amputees.

    Science.gov (United States)

    Samitier, C Beatriz; Guirao, Lluis; Costea, Maria; Camós, Josep M; Pleguezuelos, Eulogio

    2016-02-01

    Lower limb amputation leads to impaired balance, ambulation, and transfers. Proper fit of the prosthesis is a determining factor for successful ambulation. Vacuum-assisted socket systems extract air from the socket, which decreases pistoning and probability of soft-tissue injuries and increases proprioception and socket comfort. To investigate the effect of vacuum-assisted socket system on transtibial amputees' performance-based and perceived balance, transfers, and gait. Quasi-experimental before-and-after study. Subjects were initially assessed using their prosthesis with the regular socket and re-evaluated 4 weeks after fitting including the vacuum-assisted socket system. We evaluated the mobility grade using Medicare Functional Classification Level, Berg Balance Scale, Four Square Step Test, Timed Up and Go Test, the 6-Min Walk Test, the Locomotor Capabilities Index, Satisfaction with Prosthesis (SAT-PRO questionnaire), and Houghton Scale. A total of 16 unilateral transtibial dysvascular amputees, mean age 65.12 (standard deviation = 10.15) years. Using the vacuum-assisted socket system, the patients significantly improved in balance, gait, and transfers: scores of the Berg Balance Scale increased from 45.75 (standard deviation = 6.91) to 49.06 (standard deviation = 5.62) (p balance, gait, and transfers in over-50-year-old dysvascular transtibial amputees. This study gives more insight into the use of vacuum-assisted socket systems to improve elderly transtibial dysvascular amputees' functionality and decrease their risk of falls. The use of an additional distal valve in the socket should be considered in patients with a lower activity level. © The International Society for Prosthetics and Orthotics 2014.

  11. Charge balance functions in a scenario of continuing charge production in quark matter

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Ying-Hua [Harbin Institute of Technology, Department of Physics, Heilongjiang (China); Zhang, Wei-Ning [Harbin Institute of Technology, Department of Physics, Heilongjiang (China); Dalian University of Technology, School of Physics and Optoelectronic Technology, Liaoning (China)

    2015-11-15

    We study the charge balance functions of π{sup +}π{sup -} and K{sup +}K{sup -} in a scenario of continuing charge creation in a strongly interacting quark-gluon plasma (QGP) in high-energy heavy-ion collisions, using relativistic hydrodynamics and the lattice QCD results of quark susceptibilities and the equation of state of the QGP. We find that the charge balance functions are dominated by their QGP components because most charges are produced before the hadronic stage. The hadronic component of the balance function of π{sup +}π{sup -} is small but non-negligible. The balance function of K{sup +}K{sup -} has a negative hadronic component because the strangeness decreases during the system evolution. The correlation between light and strange quarks leads to small enhancements of the balance functions at small rapidity difference. (orig.)

  12. Charge balance functions in a scenario of continuing charge production in quark matter

    Science.gov (United States)

    Pan, Ying-Hua; Zhang, Wei-Ning

    2015-11-01

    We study the charge balance functions of π+π- and K+K- in a scenario of continuing charge creation in a strongly interacting quark-gluon plasma (QGP) in high-energy heavy-ion collisions, using relativistic hydrodynamics and the lattice QCD results of quark susceptibilities and the equation of state of the QGP. We find that the charge balance functions are dominated by their QGP components because most charges are produced before the hadronic stage. The hadronic component of the balance function of π+π- is small but non-negligible. The balance function of K+K- has a negative hadronic component because the strangeness decreases during the system evolution. The correlation between light and strange quarks leads to small enhancements of the balance functions at small rapidity difference.

  13. Radiation hydrodynamics integrated in the PLUTO code

    Science.gov (United States)

    Kolb, Stefan M.; Stute, Matthias; Kley, Wilhelm; Mignone, Andrea

    2013-11-01

    Aims: The transport of energy through radiation is very important in many astrophysical phenomena. In dynamical problems the time-dependent equations of radiation hydrodynamics have to be solved. We present a newly developed radiation-hydrodynamics module specifically designed for the versatile magnetohydrodynamic (MHD) code PLUTO. Methods: The solver is based on the flux-limited diffusion approximation in the two-temperature approach. All equations are solved in the co-moving frame in the frequency-independent (gray) approximation. The hydrodynamics is solved by the different Godunov schemes implemented in PLUTO, and for the radiation transport we use a fully implicit scheme. The resulting system of linear equations is solved either using the successive over-relaxation (SOR) method (for testing purposes) or using matrix solvers that are available in the PETSc library. We state in detail the methodology and describe several test cases to verify the correctness of our implementation. The solver works in standard coordinate systems, such as Cartesian, cylindrical, and spherical, and also for non-equidistant grids. Results: We present a new radiation-hydrodynamics solver coupled to the MHD-code PLUTO that is a modern, versatile, and efficient new module for treating complex radiation hydrodynamical problems in astrophysics. As test cases, either purely radiative situations, or full radiation-hydrodynamical setups (including radiative shocks and convection in accretion disks) were successfully studied. The new module scales very well on parallel computers using MPI. For problems in star or planet formation, we added the possibility of irradiation by a central source.

  14. Multi-Objective Control of Balancing Systems for Li-Ion Battery Packs

    DEFF Research Database (Denmark)

    Barreras, Jorge Varela; Pinto, Claudio; de Castro, Ricardo;

    2014-01-01

    While a great number of battery balancing circuit topologies have been proposed, the unique control objective typically pursued is equalization of single cell charge. However, a balancing circuit could offer potentially more control features, especially with topologies able to provide bidirection...

  15. Balancing priorities

    DEFF Research Database (Denmark)

    Mønsted, Troels; Johansen, Andreas Kaas; Lauridsen, Frederik Vahr Bjarnø

    2016-01-01

    a heterogeneous ensemble of care providers. In this paper, we present findings from a field study of coordinative work in distributed elder care in Denmark. The purpose of this study is to further our understanding of the coordinative challenges of distributed elder care, and to inform design of new care......, that are needed by the healthcare system, but also the work involved in balancing priorities....

  16. Construction of a trivalent candidate Shigella vaccine strain with host-vector balanced-lethal system

    Institute of Scientific and Technical Information of China (English)

    芮贤良; 徐永强; 吴旭东; 苏国富; 黄翠芬

    1997-01-01

    A trivalent live Shigella vaccine candidate FSD01 against S. flexneri 2a, S. sonnei and S. dysen-teriae I was constructed. This candidate strain was based on the S. flexneri 2a vaccine T32. By homologous recombi-nation exchange, the chromosomal asd gene of T32 was site-specifically inactivated, resulting in the strain unable to grow normally in LB broth, while another asd gene of S. mutans was employed to construct an Asd complementary vector. This combination of asd ’host/ Asd+ vector formed a balanced-lethal expression system in T32 strain. By use of this system, two important protective antigen genes coding for S. sonnei Form I antigen and Shiga toxin B subunit were cloned and expressed in T32, which led to the construction of trivalent candidate vaccine FSD01. Experimental results showed that this strain was genetically stable, but its recombinant plasmid was non-resistant. Moreover, it was able to effectively express trivalent antigens in one host and induce protective responses in mice against the

  17. Global Classical Solutions for Partially Dissipative Hyperbolic System of Balance Laws

    Science.gov (United States)

    Xu, Jiang; Kawashima, Shuichi

    2014-02-01

    The basic existence theory of Kato and Majda enables us to obtain local-in-time classical solutions to generally quasilinear hyperbolic systems in the framework of Sobolev spaces (in x) with higher regularity. However, it remains a challenging open problem whether classical solutions still preserve well-posedness in the case of critical regularity. This paper is concerned with partially dissipative hyperbolic system of balance laws. Under the entropy dissipative assumption, we establish the local well-posedness and blow-up criterion of classical solutions in the framework of Besov spaces with critical regularity with the aid of the standard iteration argument and Friedrichs' regularization method. Then we explore the theory of function spaces and develop an elementary fact that indicates the relation between homogeneous and inhomogeneous Chemin-Lerner spaces (mixed space-time Besov spaces). This fact allows us to capture the dissipation rates generated from the partial dissipative source term and further obtain the global well-posedness and stability by assuming at all times the Shizuta-Kawashima algebraic condition. As a direct application, the corresponding well-posedness and stability of classical solutions to the compressible Euler equations with damping are also obtained.

  18. Deciding between compensated volume balance and real time transient models for pipeline leak detection system

    Energy Technology Data Exchange (ETDEWEB)

    Baptista, Renan Martins [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas. Div. de Explotacao]. E-mail: renan@cenpes.petrobras.com.br

    2000-07-01

    This paper describes a technical procedure to assess a software based leak detection system (LDS), by deciding between a simpler low cost, less effective product, having a fast installation and tuning, and a complex one with high cost and efficiency, which however takes a long time to be properly installed. This is a common decision among the pipeline operating companies, considering that the majority of the lines are short, with single phase liquid flow (which may include batches), basic communication system and instrumentation. Service companies offer realistic solutions for liquid flow, but usually designed to big pipeline networks, flowing multiple batches and allowing multiple fluid entrances and deliveries. Those solutions are sometimes impractical to short pipelines, due to its high cost, as well as long tuning procedures, complex instrumentation, communication and computer requirements. It is intended to approach here the best solution according to its cost. In a practical sense, it means to differentiate the various LDS techniques. Those techniques are available in a considerable number, and they are still spreading, according to the different scenarios. However, two most known and worldwide implemented techniques hold the majority of the market: the Compensated Volume Balance (CVB), which is less accurate, reliable and robust, but cheaper, simpler and faster to install, and the Real Time Transient Model (RTTM), which is very reliable, accurate and robust, but expensive and complex. This work will describe a way to define whether one can use or not a CVB in a pipeline. (author)

  19. A simple, mass balance model of carbon flow in a controlled ecological life support system

    Science.gov (United States)

    Garland, Jay L.

    1989-01-01

    Internal cycling of chemical elements is a fundamental aspect of a Controlled Ecological Life Support System (CELSS). Mathematical models are useful tools for evaluating fluxes and reservoirs of elements associated with potential CELSS configurations. A simple mass balance model of carbon flow in CELSS was developed based on data from the CELSS Breadboard project at Kennedy Space Center. All carbon reservoirs and fluxes were calculated based on steady state conditions and modelled using linear, donor-controlled transfer coefficients. The linear expression of photosynthetic flux was replaced with Michaelis-Menten kinetics based on dynamical analysis of the model which found that the latter produced more adequate model output. Sensitivity analysis of the model indicated that accurate determination of the maximum rate of gross primary production is critical to the development of an accurate model of carbon flow. Atmospheric carbon dioxide was particularly sensitive to changes in photosynthetic rate. The small reservoir of CO2 relative to large CO2 fluxes increases the potential for volatility in CO2 concentration. Feedback control mechanisms regulating CO2 concentration will probably be necessary in a CELSS to reduce this system instability.

  20. Impact of physical properties of mixture of diesel and biodiesel fuels on hydrodynamic characteristics of fuel injection system

    Directory of Open Access Journals (Sweden)

    Filipović Ivan M.

    2014-01-01

    Full Text Available One of the alternative fuels, originating from renewable sources, is biodiesel fuel, which is introduced in diesel engines without major construction modifications on the engine. Biodiesel fuel, by its physical and chemical properties, is different from diesel fuel. Therefore, it is expected that by the application of a biodiesel fuel, the characteristic parameters of the injection system will change. These parameters have a direct impact on the process of fuel dispersion into the engine cylinder, and mixing with the air, which results in an impact on the quality of the combustion process. Method of preparation of the air-fuel mixture and the quality of the combustion process directly affect the efficiency of the engine and the level of pollutant emissions in the exhaust gas, which today is the most important criterion for assessing the quality of the engine. The paper presents a detailed analysis of the influence of physical properties of a mixture of diesel and biodiesel fuels on the output characteristics of the fuel injection system. The following parameters are shown: injection pressure, injection rate, the beginning and duration of injection, transformation of potential into kinetic energy of fuel and increase of energy losses in fuel injection system of various mixtures of diesel and biodiesel fuels. For the analysis of the results a self-developed computer program was used to simulate the injection process in the system. Computational results are verified using the experiment, for a few mixtures of diesel and biodiesel fuels. This paper presents the verification results for diesel fuel and biodiesel fuel in particular.

  1. Semiactive balancing control scheme in a rotor - bearing system supported on Mr. Dampers: design and experiments

    Energy Technology Data Exchange (ETDEWEB)

    Silva Navarro, Gerardo; Cabrera Amado, Alvaro [Cinvestav, IPN, Mexico, D.F. (Mexico)

    2007-11-15

    This paper deals with the problem of semiactive balancing control of a rotor-bearing system, where one journal bearings is supported on two radial Magneto-Rheological (MR) dampers. The mathematical model of the rotor-bearing system results from an orthotropic Jeffcott-like model and the dynamics associated to the MR dampers, whose rheological properties depend on the current inputs. For control purposes we use the Choi-Lee-Park polynomial for the MR dampers, which is quite consistent with the tpical nonlinear and complex hysteresis behavior and also simplifies the physical implementation on an experimental setup. The semiactive control scheme for the unbalance reponse of the rotor-bearing system is synthesized using sliding-mode control techniques. Some numerical and experimental results are included to illustrate the dynamic performance and robustness of the overall system. [Spanish] En este trabajo se abora el problema de control semiactivo del desbalance en un sistema rotor-chumacera, donde una de las chumaceras convencionales se monta sobre una suspension con dos amortiguadores Magneto-Reologicos (MR) radiales. El modelo matematico del sistema rotorchumacera se obtiene de un modelo tipo Jefcott ortotropico y la dinamica de los amortiguadores MR, cuyas propiedades reologicas dependen de las corrientes electricas de alimentacion. Para propositos de control se emplea el modelo polinomial de Choi-Lee-Park para los dos amortiguadores MR, el cual es consistente con el tipico comportamiento no-lineal y de histeresis, permitiendo simplificar su implementacion fisica en una plataforma experimental. El esquema de control semiactivo de la respuesta al desbalance, en el sistema rotor-chumacera, se basa en las tecnicas de control por modos deslizantes. Se presentan algunos resultados de simulacion numerica y experimentos que utilizan el funcionamiento y robustez del sistema completo.

  2. Balancing Multiple Objectives Using a Classification-Based Forest Management System in Changbai Mountains, China

    Science.gov (United States)

    Zhao, Fuqiang; Yang, Jian; Liu, Zhihua; Dai, Limin; He, Hong S.

    2011-12-01

    Contemporary forest management often consists of multiple objectives, including restoration of human-impacted forested landscapes toward their range of natural variability (RNV) and sustainable levels of timber production. Balancing multiple management objectives is often challenging due to intrinsic conflicts between these objectives and a lack of reference conditions for evaluating the effectiveness of forest restoration efforts. We used a spatially explicit forest landscape model to assess how well a classification-based forest management (CFM) system could achieve multiple objectives in a Korean pine broadleaf mixed forest ecosystem at Changbai Mountain in Northeast China. The CFM system divided the forest landscape into three management areas (Commercial Forest, Special Ecological Welfare Forest, and General Ecological Welfare Forest), each with its own management objectives and prescriptions, but with an overall goal of increasing the ecological and economic sustainability of the entire landscape. The zoning approach adopted in the Chinese CFM system is very similar to the TRIAD approach that is being advocated for managing public forests in Canada. In this study, a natural disturbance scenario and seven harvest scenarios (one identical to the current harvest regime and six alternative scenarios) were simulated to examine how tree species composition, age structure, and timber production at the landscape level can be affected by different strategies under the CFM system. The results indicated that the current forest management regime would not only fail to reach the designated timber production level but also move the forest landscape far away from its RNV. In order to return the currently altered forest landscape to approach its RNV while providing a stable level of timber production over time, harvest intensities should be reduced to a level that is equivalent to the amount of timber removals that would occur under the natural disturbances; and the

  3. Application of isotopic tracers as a tool for understanding hydrodynamic behavior of the highly exploited Diass aquifer system (Senegal)

    Science.gov (United States)

    Madioune, Diakher Hélène; Faye, Serigne; Orban, Philippe; Brouyère, Serge; Dassargues, Alain; Mudry, Jacques; Stumpp, Christine; Maloszewski, Piotr

    2014-04-01

    The Diass horst aquifer system located 50 km east of Dakar (Senegal) is exploited in two main aquifers covered by a sandy superficial aquifer: the confined/unconfined Palaeocene karstic limestone and the confined Maastrichtian sandstone aquifer underneath. This system has experienced intensive groundwater abstraction during the last 50 years to supply increasing water demand, agricultural and industrial needs. The high abstraction rate from 1989 to 2009 (about 109,000 m3/d) has caused a continuous groundwater level decline (up to 30 m), a modification of the groundwater flow and salinization in parts of the aquifers. The objective of the study is to improve our understanding of the system functioning with regards to high pumping, identify the geochemical reactions that take place in the system, infer origin and timing of recharge by using mainly stable (δ18O, δ2H, 13C) and radioactive (3H and 14C) isotopes. Water types defined in the Piper diagram vary in order of abundance from Ca-HCO3 (65%), Ca/Na-Cl (20%), Na-HCO3 (3%) and Na-Cl (12%). Values of δ18O and δ2H for the superficial aquifer range between -5.8 and -4.2‰ and between -42 and -31‰, respectively. For the Palaeocene aquifer they range from -5.8 to -5.0‰ and from -38 to -31‰, respectively; values in the Maastrichtian aquifer are between -5.9 and -4.3‰ for δ18O and -38 to -26‰ for δ2H. Plotted against the conventional δ18O vs δ2H diagram, data from the upper aquifer exhibit a dispersed distribution with respect to isotopic fractionation while those of the Palaeocene and Maastrichtian aquifers are aligned parallel and slightly below/or on the Global Meteoric Water Line (GMWL) evidencing ancient waters which had evaporated during infiltration. The low tritium (generally tritium (1.2-4.3 TU) and 14C (65.7-70.8 pmc) values indicate some mixture with recent water likely through faulting and vertical drainage from the upper to deeper aquifers as well as lateral flow along flow paths to the

  4. Cryosphere water balance in the HKH-system: case study Batura Glacier (Upper Hunza, Karakoram)

    Science.gov (United States)

    Winiger, M.; Boerst, U.

    2012-12-01

    Investigations on climate dynamics and related responses of the cryosphere in the Hindukush-Karakoram-Himalaya (HKH) increasingly result in regional different functional patterns. A predominant loss of ice and snow is documented for most of the region. Nevertheless, in the northwestern part, mainly in the Karakoram, several studies identified exemptions from the general HKH-pattern, either for individual glaciers or altitudinal ranges. Coordinated comparative studies, based on comparable methodological approaches and data bases might help to provide a better understanding of climate-cryosphere-runoff-systems. 'Third Pole Environment' (TEP), as well as the 'Upper Indus Basin' Initiative (UIB) of the 'International Centre for Integrated Mountain Development' (ICIMOD) promote and develop coordinated campaigns for the assessment of high altitude water balances in the HKH mountain ranges. As a first step, inventories of glaciers and snow-cover for HKH, the Tibetan Plateau, as well as its neighboring mountain ranges have been carried out. Glacier typology, climate related spatial and temporal dynamics, the impact of black carbon, dust and other influencing factors will further differentiate general inventories. In a next phase, case studies at selected sites, based on comparable approaches, thorough quality assessments of existing data series have been initiated by several research groups - up to now with only little coordination. Identification of case study sites should take advantage of previous studies. Although proper long-term monitoring is almost completely lacking, several glaciers in the Karakoram have repeatedly been investigated. Among them Raikot Glacier (Nanga Parbat), Biafo-Hispar glacier system, Baltoro Glacier (K2), and Batura Glacier (Gojal, Upper Hunza) are comparatively well documented examples. As part of the UIB-initiative, Batura, Passu and Baltoro Glaciers are in the process of repeat investigations of mass-balance. Selected first results of

  5. Comparison of intraobserver single-task reliabilities of the Interactive Balance System (IBS) and Vertiguard in asymptomatic subjects.

    Science.gov (United States)

    Schwesig, René; Hollstein, Lisa; Plontke, Stefan K; Delank, Karl-Stefan; Fieseler, Georg; Rahne, Torsten

    2017-03-01

    The intraobserver reliabilities of the Interactive Balance System (IBS) and Vertiguard were compared in 30 asymptomatic volunteers. Relative reliability for all IBS single tasks and parameters in the IBS was excellent (intraclass correlation coefficient, ICC ≥0.75). The ICC values ranged from 0.78 to 0.89. The ICC values of the Vertiguard system ranged from 0 to 0.75. The cumulative measure of injury risk of the Vertiguard system was highly reliable.

  6. A Vibrotactile and Plantar Force Measurement-Based Biofeedback System: Paving the Way towards Wearable Balance-Improving Devices

    OpenAIRE

    Christina Zong-Hao Ma; Anson Hong-Ping Wan; Duo Wai-Chi Wong; Yong-Ping Zheng; Winson Chiu-Chun Lee

    2015-01-01

    Although biofeedback systems have been used to improve balance with success, they were confined to hospital training applications. Little attempt has been made to investigate the use of in-shoe plantar force measurement and wireless technology to turn hospital training biofeedback systems into wearable devices. This research developed a wearable biofeedback system which detects body sway by analyzing the plantar force and provides users with the corresponding haptic cues. The effects of this ...

  7. Dynamic density functional theory with hydrodynamic interactions: theoretical development and application in the study of phase separation in gas-liquid systems.

    Science.gov (United States)

    Kikkinides, E S; Monson, P A

    2015-03-07

    Building on recent developments in dynamic density functional theory, we have developed a version of the theory that includes hydrodynamic interactions. This is achieved by combining the continuity and momentum equations eliminating velocity fields, so the resulting model equation contains only terms related to the fluid density and its time and spatial derivatives. The new model satisfies simultaneously continuity and momentum equations under the assumptions of constant dynamic or kinematic viscosity and small velocities and/or density gradients. We present applications of the theory to spinodal decomposition of subcritical temperatures for one-dimensional and three-dimensional density perturbations for both a van der Waals fluid and for a lattice gas model in mean field theory. In the latter case, the theory provides a hydrodynamic extension to the recently studied dynamic mean field theory. We find that the theory correctly describes the transition from diffusive phase separation at short times to hydrodynamic behaviour at long times.

  8. Balance Problems

    Science.gov (United States)

    ... you are having balance problems, see your doctor. Balance disorders can be signs of other health problems, such ... cases, treating the illness that is causing the disorder will help with the balance problem. Exercises, a change in diet, and some ...

  9. Mass Balance Modeling for Electric Arc Furnace and Ladle Furnace System in Steelmaking Facility in Turkey

    Institute of Scientific and Technical Information of China (English)

    (I)smail Ekmek(c)i; Ya(s)ar Yetisken; (U)nal (C)amdali

    2007-01-01

    In the electric arc furnace (EAF) steel production processes, scrap steel is principally used as a raw material instead of iron ore. In the steelmaking process with EAF, scrap is first melted in the furnace and then the desired chemical composition of the steel can be obtained in a special furnace such as ladle furnace (LF). This kind of furnace process is used for the secondary refining of alloy steel. LF furnace offers strong heating fluxes and enables precise temperature control, thereby allowing for the addition of desired amounts of various alloying elements. It also provides outstanding desulfurization at high-temperature treatment by reducing molten steel fluxes and removing deoxidation products. Elemental analysis with mass balance modeling is important to know the precise amount of required alloys for the LF input with respect to scrap composition. In present study, chemical reactions with mass conservation law in EAF and LF were modeled altogether as a whole system and chemical compositions of the final steel alloy output can be obtained precisely according to different scrap compositions, alloying elements ratios, and other input amounts. Besides, it was found that the mass efficiency for iron element in the system is 95.93%. These efficiencies are calculated for all input elements as 8.45% for C, 30.31% for Si, 46.36% for Mn, 30.64% for P, 41.96% for S, and 69.79% for Cr, etc. These efficiencies provide valuable ideas about the amount of the input materials that are vanished or combusted for 100 kg of each of the input materials in the EAF and LF system.

  10. Configuring balanced scorecards for measuring health system performance: evidence from 5 years' evaluation in Afghanistan.

    Directory of Open Access Journals (Sweden)

    Anbrasi Edward

    2011-07-01

    Full Text Available BACKGROUND: In 2004, Afghanistan pioneered a balanced scorecard (BSC performance system to manage the delivery of primary health care services. This study examines the trends of 29 key performance indicators over a 5-year period between 2004 and 2008. METHODS AND FINDINGS: Independent evaluations of performance in six domains were conducted annually through 5,500 patient observations and exit interviews and 1,500 provider interviews in >600 facilities selected by stratified random sampling in each province. Generalized estimating equation (GEE models were used to assess trends in BSC parameters. There was a progressive improvement in the national median scores scaled from 0-100 between 2004 and 2008 in all six domains: patient and community satisfaction of services (65.3-84.5, p<0.0001; provider satisfaction (65.4-79.2, p<0.01; capacity for service provision (47.4-76.4, p<0.0001; quality of services (40.5-67.4, p<0.0001; and overall vision for pro-poor and pro-female health services (52.0-52.6. The financial domain also showed improvement until 2007 (84.4-95.7, p<0.01, after which user fees were eliminated. By 2008, all provinces achieved the upper benchmark of national median set in 2004. CONCLUSIONS: The BSC has been successfully employed to assess and improve health service capacity and service delivery using performance benchmarking during the 5-year period. However, scorecard reconfigurations are needed to integrate effectiveness and efficiency measures and accommodate changes in health systems policy and strategy architecture to ensure its continued relevance and effectiveness as a comprehensive health system performance measure. The process of BSC design and implementation can serve as a valuable prototype for health policy planners managing performance in similar health care contexts. Please see later in the article for the Editors' Summary.

  11. Modeling and Performance Evaluation of Early Arrival Discrete Time Queueing System with Load Balancing Using Geometrical Distribution

    Directory of Open Access Journals (Sweden)

    Syed Asif AliShah

    2011-10-01

    Full Text Available Load balancing is an efficient technique used to maximize throughput, optimal resource utilization, minimized response time and avoiding congestion. This can be achieved by distributing the workload evenly across two or more network stations, nodes or buffers, links, central processing units, hard drives, or other resources. In this paper, we have modeled and developed a load balancing approach in a discrete-time domain to analyze and evaluate the system of finite network buffers using an early arrival system. Our approach of modeling such a system consists of two steps. The first step is the determination of all system-state stages and their corresponding transition probabilities. Next, we compute various performance measures by utilizing the system state transition probabilities for its steady-state behavior.

  12. Balancing control method by dispersed generators based on H{sub {infinity}} control theory in DC power feeding system

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Kenichi; Goya, Tomonori; Senjyu, Tomonobu; Yona, Atsushi; Urasaki, Naomitsu [University of the Ryukyus, 1 Senbaru Nishihara-cho Nakagami, Okinawa 903-0213 (Japan); Funabashi, Toshihisa [Meidensha Corporation, 36-2 Nihonbashi-Hakozakicho Chuo-ku, Tokyo 103-8513 (Japan); Kim, Chul-Hwan [Sungkyunkwan University and NPT Center, Suwon City 440-746 (Korea)

    2011-01-15

    Recently, dispersed generators have been installed in distribution network to supply power to commercial facilities. Renewable energy generation contains output power fluctuations and distributed generator produces sluggish response for power demand. In order to overcome these problems, an ultra capacitor energy storage system is used for compensating the instantaneous power imbalance. However, use of a large capacity ultra capacitor energy system increases system cost. In addition, PPSs (Power Producer and Supplier) that own these generators are supposed to achieve 30-min balancing control for stable supply of electric power. This paper proposes a control system to achieve both 30-min balancing control and interconnection point power flow control by using a fuel cell and an ultra capacitor based on the H{sub {infinity}} control theory. Besides, remaining storage energy of the ultra capacitor is controlled to be constant to maintain compensation capability. Effectiveness of the proposed control system is verified by using simulation results. (author)

  13. Foundations of radiation hydrodynamics

    CERN Document Server

    Mihalas, Dimitri

    1999-01-01

    Radiation hydrodynamics is a broad subject that cuts across many disciplines in physics and astronomy: fluid dynamics, thermodynamics, statistical mechanics, kinetic theory, and radiative transfer, among others. The theory developed in this book by two specialists in the field can be applied to the study of such diverse astrophysical phenomena as stellar winds, supernova explosions, and the initial phases of cosmic expansion, as well as the physics of laser fusion and reentry vehicles. As such, it provides students with the basic tools for research on radiating flows.Largely self-contained,

  14. Balanced Rotating Spray Tank and Pipe Cleaning and Cleanliness Verification System

    Science.gov (United States)

    Caimi, Raoul E. B. (Inventor); Thaxton, Eric A. (Inventor)

    1998-01-01

    A system for cleaning and verifying the cleanliness of the interior surfaces of hollow items, such as small bottles, tanks, pipes and tubes, employs a rotating spray head for supplying a gas-liquid cleaning mixture to the item's surface at a supersonic velocity. The spray head incorporates a plurality of nozzles having diverging cross sections so that the incoming gas-liquid mixture is first converged within the spray head and then diverged through the nozzles, thereby accelerating the mixture to a supersonic velocity. In the preferred embodiment, three nozzles are employed; one forwardly facing nozzle at the end of the spray head and two oppositely facing angled nozzles exiting on opposite sides of the spray head which balance each other, and therefore impart no net side load on the spray head. A drive mechanism is provided to rotate the spray head and at the same time move the head back and forth within the item to be cleaned. The drive mechanism acts on a long metal tube to which the spray head is fixed, and thus no moving parts are exposed to the interior surfaces of the items to be cleaned, thereby reducing the risk of contamination.

  15. Mathematical modelling of nutrient balance of a goldfish (Carassius auratus Linn. recirculating aquaculture system (GRAS

    Directory of Open Access Journals (Sweden)

    Sudeep Puthravilakom Sadasivan Nair

    2010-08-01

    Full Text Available In the present study, a goldfish (Carassius auratus Linn. recirculating aquaculture system (GRAS has been developed. The GRAS consisted of a culture tank, a screen filter and a foam fractionator for removal of particulate and dissolved solids and a trickling filter for conversion of ammonium- and nitrite-nitrogen to relatively harmless nitrate-nitrogen. The culture of goldfish at a stocking density of 1.08 kg/m3 was continued for a period of two and half months. Based on mass balance analysis of ammonium- and nitrate-nitrogen and assuming the trickling filter to be a plug flow reactor, a model was formulated to determine the necessary recirculation flow rate at different times of culture for maintaining the major nutrients, viz., ammonium- and nitrate-nitrogen below their permissible limits. The model was calibrated and validated using the real time data obtained from the experimental run. The high values of coefficient of determination and low values of root mean square error show the effectiveness of the model.

  16. Land-Based Wind Plant Balance-of-System Cost Drivers and Sensitivities (Poster)

    Energy Technology Data Exchange (ETDEWEB)

    Mone, C.; Maples, B.; Hand, M.

    2014-04-01

    With Balance of System (BOS) costs contributing up to 30% of the installed capital cost, it is fundamental to understand the BOS costs for wind projects as well as potential cost trends for larger turbines. NREL developed a BOS model using project cost estimates developed by industry partners. Aspects of BOS covered include engineering and permitting, foundations for various wind turbines, transportation, civil work, and electrical arrays. The data introduce new scaling relationships for each BOS component to estimate cost as a function of turbine parameters and size, project parameters and size, and geographic characteristics. Based on the new BOS model, an analysis to understand the non‐turbine wind plant costs associated with turbine sizes ranging from 1-6 MW and wind plant sizes ranging from 100-1000 MW has been conducted. This analysis establishes a more robust baseline cost estimate, identifies the largest cost components of wind project BOS, and explores the sensitivity of the capital investment cost and the levelized cost of energy to permutations in each BOS cost element. This presentation shows results from the model that illustrate the potential impact of turbine size and project size on the cost of energy from US wind plants.

  17. Advances in numerical methods for the solution of population balance equations for disperse phase systems

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Accurate prediction of the evolution of particle size distribution is critical to determining the dynamic flow structure of a disperse phase system.A population balance equation(PBE),a non-linear hyperbolic equation of the number density function,is usually employed to describe the micro-behavior(aggregation,breakage,growth,etc.) of a disperse phase and its effect on particle size distribution.Numerical solution is the only choice in most cases.In this paper,three different numerical methods(direct discretization methods,Monte Carlo methods,and moment methods) for the solution of a PBE are evaluated with regard to their ease of implementation,computational load and numerical accuracy.Special attention is paid to the relatively new and superior moment methods including quadrature method of moments(QMOM),direct quadrature method of moments(DQMOM),modified quadrature method of moments(M-QMOM),adaptive direct quadrature method of moments(ADQMOM),fixed pivot quadrature method of moments(FPQMOM),moving particle ensemble method(MPEM) and local fixed pivot quadrature method of moments(LFPQMOM).The prospects of these methods are discussed in the final section,based on their individual merits and current state of development of the field.

  18. Advances in numerical methods for the solution of population balance equations for disperse phase systems

    Institute of Scientific and Technical Information of China (English)

    SU JunWei; GU ZhaoLin; XU X.Yun

    2009-01-01

    Accurate prediction of the evolution of particle size distribution is critical to determining the dynamic flow structure of a disperse phase system.A population balance equation(PBE),a non-linear hyperbolic equation of the number density function,is usually employed to describe the micro-behavior(aggregation,breakage,growth,etc.)of a disperse phase and its effect on particle size distribution.Numerical solution is the only choice in most cases.In this paper,three different numerical methods(direct discretization methods,Monte Carlo methods,and moment methods)for the solution of a PBE are evaluated with regard to their ease of implementation,computational load and numerical accuracy.Special attention is paid to the relatively new and superior moment methods including quadrature method of moments(QMOM),direct quadrature method of moments(DQMOM),modified quadrature method of moments(M-QMOM),adaptive direct quadrature method of moments(ADOMOM),fixed pivot quadrature method of moments(FPQMOM),moving particle ensemble method(MPEM)and local fixed pivot quadrature method of moments(LFPQMOM).The prospects of these methods ere discussed in the final section,based on their individual merits and current state of development of the field.

  19. The endogenous cannabinoid system affects energy balance via central orexigenic drive and peripheral lipogenesis.

    Science.gov (United States)

    Cota, Daniela; Marsicano, Giovanni; Tschöp, Matthias; Grübler, Yvonne; Flachskamm, Cornelia; Schubert, Mirjam; Auer, Dorothee; Yassouridis, Alexander; Thöne-Reineke, Christa; Ortmann, Sylvia; Tomassoni, Federica; Cervino, Cristina; Nisoli, Enzo; Linthorst, Astrid C E; Pasquali, Renato; Lutz, Beat; Stalla, Günter K; Pagotto, Uberto

    2003-08-01

    The cannabinoid receptor type 1 (CB1) and its endogenous ligands, the endocannabinoids, are involved in the regulation of food intake. Here we show that the lack of CB1 in mice with a disrupted CB1 gene causes hypophagia and leanness. As compared with WT (CB1+/+) littermates, mice lacking CB1 (CB1-/-) exhibited reduced spontaneous caloric intake and, as a consequence of reduced total fat mass, decreased body weight. In young CB1-/- mice, the lean phenotype is predominantly caused by decreased caloric intake, whereas in adult CB1-/- mice, metabolic factors appear to contribute to the lean phenotype. No significant differences between genotypes were detected regarding locomotor activity, body temperature, or energy expenditure. Hypothalamic CB1 mRNA was found to be coexpressed with neuropeptides known to modulate food intake, such as corticotropin-releasing hormone (CRH), cocaine-amphetamine-regulated transcript (CART), melanin-concentrating hormone (MCH), and preproorexin, indicating a possible role for endocannabinoid receptors within central networks governing appetite. CB1-/- mice showed significantly increased CRH mRNA levels in the paraventricular nucleus and reduced CART mRNA levels in the dorsomedial and lateral hypothalamic areas. CB1 was also detected in epidydimal mouse adipocytes, and CB1-specific activation enhanced lipogenesis in primary adipocyte cultures. Our results indicate that the cannabinoid system is an essential endogenous regulator of energy homeostasis via central orexigenic as well as peripheral lipogenic mechanisms and might therefore represent a promising target to treat diseases characterized by impaired energy balance.

  20. On the diversity enhancement and power balancing of per-subcarrier antenna selection in OFDM systems

    KAUST Repository

    Park, Kihong

    2010-09-01

    In this paper, we consider multi-carrier systems with multiple transmit antennas under a power balancing constraint. Applying transmit antenna selection and discrete rate adaptive modulation using M-ary quadrature amplitude modulation (QAM) according to the channel variation per subcarrier, we develop an optimal antenna selection scheme in terms of maximum spectral efficiency where all the possible grouping to send the same information bearing signals in a group of subcarriers are searched and the groups of subcarriers to provide the frequency diversity gain are formed. In addition, we propose a suboptimal method to reduce the computational complexity of the optimal method. The suboptimal scheme consider only the subcarriers under outage and those are combined sequentially until it meets a required SNR. Numerical results show that the proposed suboptimal method with diversity combining outperforms the optimal antenna selection without diversity combining introduced in [1], especially for low SNR region and offers the spectral efficiency close to that of the optimal method with diversity combining, while maintaining lower complexity. ©2010 IEEE.

  1. Selenium removal and mass balance in a constructed flow-through wetland system.

    Science.gov (United States)

    Gao, S; Tanji, K K; Lin, Z Q; Terry, N; Peters, D W

    2003-01-01

    A field study on the removal of Se from agricultural subsurface drainage was conducted from May 1997 to February 2001 in the Tulare Lake Drainage District (TLDD) of San Joaquin Valley, California. A flow-through wetland system was constructed consisting of ten 15- x 76-m unlined cells that were continuously flooded and planted with either a monotype or combination of plants, including sturdy bulrush [Schoenoplectus robustus (Pursh) M.T. Strong], baltic rush (Juncus balticus Willd.), smooth cordgrass (Spartina alterniflora Loisel.), rabbitsfoot grass [Polypogon monspeliensis (L.) Desf.], salt-grass lDistichlis spicata (L.) Greene], cattail (Typha latifolia L.), tule [Schoenoplectus acutus (Muhl. ex Bigelow) A. Löve & D. Löve], and widgeon grass (Ruppia maritima L.). One cell had no vegetation planted. The objectives of this research were to evaluate Se removal efficiency of each wetland cell and to carry out a mass balance on Se. The inflow drainage water to the cells had average annual Se concentrations of 19 to 22 microg L(-1) dominated by selenate [Se(VI), 95%]. Average weekly water residence time varied from about 3 to 15 d for Cells 1 through 7 (target 7 d), 19 to 33 d for Cells 8 and 9 (target 21 d), and 13 to 18 d for Cell 10 (target 14 d). Average weekly Se concentration ratios of outflow to inflow ranged from 0.45 to 0.79 and mass ratio (concentration x water volume) from 0.24 to 0.52 for year 2000, that is, 21 to 55% reduction in Se concentration and 48 to 76% Se removal in mass by the wetland, respectively. The nonvegetated cell showed the least Se removal both in concentration and in mass. The global mass balance showed that on the average about 59% of the total inflow Se was retained within the cells and Se outputs were outflow (35%), seepage (4%), and volatilization (2%). Independent measurements of the Se retained in the cells totaled 53% of the total Se inflow: 33% in the surface (0-20 cm) sediment, 18% in the organic detrital layer above the

  2. Molecular hydrodynamics from memory kernels

    CERN Document Server

    Lesnicki, Dominika; Carof, Antoine; Rotenberg, Benjamin

    2016-01-01

    The memory kernel for a tagged particle in a fluid, computed from molecular dynamics simulations, decays algebraically as $t^{-3/2}$. We show how the hydrodynamic Basset-Boussinesq force naturally emerges from this long-time tail and generalize the concept of hydrodynamic added mass. This mass term is negative in the present case of a molecular solute, at odds with incompressible hydrodynamics predictions. We finally discuss the various contributions to the friction, the associated time scales and the cross-over between the molecular and hydrodynamic regimes upon increasing the solute radius.

  3. Physical stability of coconut oil lotions formulated using hydrophile-lipophile balance system of various emulsifier pairs.

    Science.gov (United States)

    Boonme, Prapaporn; Maneenuan, Duangkhae; Channarong, Sunee

    2013-01-01

    The aim of this study was to prepare coconut oil lotions using a hydrophile-lipophile balance system to calculate the proportion of each nonionic surfactant used. The effects of emulsifier pairs in the formulations on physical properties (i.e., appearance, emulsion type, pH, flow type, viscosity) were investigated. The physical stability of the lotions was determined at ambient temperature (approximatley 30 degrees C) after the lotions were kept for 30 as well as 60 days and in accelerated conditions (6 freeze-thaw cycles). It was found that the formulations most tolerant to such harsh conditions were F1 and F2, o/w lotions containing 40% w/w coconut oil, 50% w/w water and 10% w/w of the mixed emulsifier of a low hydrophile-lipophile balance surfactant (sorbitan monostearate) and a high hydrophile-lipophile balance surfactant (either polyoxyethylene [20] sorbitan monooleate or polyethylene [20] sorbitan monolaurate).

  4. New Modulation Strategy to Balance the Neutral-Point Voltage for Three-Level Neutral-Clamped Inverter Systems

    DEFF Research Database (Denmark)

    Choi, Uimin; Lee, June-Seok; Lee, Kyo-Beum

    2014-01-01

    This paper proposes a new modulation strategy that balances the neutral-point voltage for three-level neutral-clamped inverter systems. The proposed modulation replaces the P-type or N-type small switching states with other switching states that do not affect the neutral-point voltage. The zero...... and medium switching states are employed to help the neutral-point voltage balancing. This method little bit increases the switching events and output total harmonic distortion. However, this method has a strong balancing ability at all regions. Further, it is very simple to implement in both space vector...... modulation and carrier-based PWM methods. Simulation and experimental results verify the validity and feasibility of the proposed new modulation strategy....

  5. A new pressure relaxation closure model for one-dimensional two-material Lagrangian hydrodynamics

    Directory of Open Access Journals (Sweden)

    Rider W.J.

    2011-01-01

    Full Text Available We present a new model for closing a system of Lagrangian hydrodynamics equations for a two-material cell with a single velocity model. We describe a new approach that is motivated by earlier work of Delov and Sadchikov and of Goncharov and Yanilkin. Using a linearized Riemann problem to initialize volume fraction changes, we require that each material satisfy its own p dV equation, which breaks the overall energy balance in the mixed cell. To enforce this balance, we redistribute the energy discrepancy by assuming that the corresponding pressure change in each material is equal. This multiple-material model is packaged as part of a two-step time integration scheme. We compare results of our approach with other models and with corresponding pure-material calculations, on two-material test problems with ideal-gas or stiffened-gas equations of state.

  6. Variable-length balanced codes for quadrature phase shift keyed systems

    Directory of Open Access Journals (Sweden)

    Xin Tu

    2015-10-01

    Full Text Available The authors outline an approach to construct capacity-approaching balanced quadrature phase shift keyed (QPSK codes. These codes ensure an equal number of different symbol values and many symbol transitions in the encoded sequence in order to assist practical demodulators to accurately recover symbol values. Their codes are comprised of instantaneously decodable variable-length codewords that exhibit excellent performance with average code rates higher than previously reported fixed-length balanced QPSK codes.

  7. Hydrological functioning and water balance in a heavily modified hydrographic system

    Science.gov (United States)

    Carbonnel, Vincent; Brion, Natacha; Elskens, Marc; Claeys, Philippe; Verbanck, Michel A.

    2017-04-01

    Rivers and canals are often the location for the historical settlement of cities and the backbone for their expansion, as they permit the transport of goods and people, the access to water for industrial activities and energy production, and the evacuation of the domestic and industrial wastewaters. In turn, human activities can result in modifications of the natural river systems to allow for instance ship transport or protection against flooding. The complex interconnected hydrographic network composed of the Zenne and the parallel Charleroi-Brussels-Scheldt Canal, which supports the development of the economy and urbanization of Brussels Metropolitan Area (Belgium), is a good example of such an altered system. The natural water course has been profoundly modified by the deviation of rivers to feed the canal, the control of the water flow in the canal by locks and pumps and the overflow exchange of water between the river and the canal for flood protection purposes. Also, the functioning of this system is strongly impacted by urban hydrology in Brussels, which results in amounts of wastewater discharged in the Zenne River that are nearly equivalent to the natural riverine flow. Water and water quality management in such complex and altered systems correspond to difficult tasks. They require, as a first step, a deep understanding of their hydrological functioning. Building an accurate water budget is also a necessary step in the investigation of the pollution sources, sinks, dynamics and mass-balance. In order to assess the water quality and provide insights for water management in the Zenne-Canal hydrographic network (cf. other contributions in this session), we established a detailed box-model representation of the water budget for the whole system, with a particular interest on the importance and the effects of the exchanges of water between the river and the canal. A particularity of this study is that, in contrast to the widespread use of hydrological

  8. Effects of a Passive Online Software Application on Heart Rate Variability and Autonomic Nervous System Balance.

    Science.gov (United States)

    Rubik, Beverly

    2017-01-01

    This study investigated whether short-term exposure to a passive online software application of purported subtle energy technology would affect heart rate variability (HRV) and associated autonomic nervous system measures. This was a randomized, double-blinded, sham-controlled clinical trial (RCT). The study took place in a nonprofit laboratory in Emeryville, California. Twenty healthy, nonsmoking subjects (16 females), aged 40-75 years, participated. Quantum Code Technology(™) (QCT), a purported subtle energy technology, was delivered through a passive software application (Heart+ App) on a smartphone placed heart rate, total power, standard deviation node-to-node, root mean square sequential difference, low frequency to high frequency ratio (LF/HF), low frequency (LF), and high frequency (HF). Paired samples t-tests showed that for the Heart+ App, mean LF/HF decreased (p = 9.5 × 10(-4)), while mean LF decreased in a trend (p = 0.06), indicating reduced sympathetic dominance. Root mean square sequential difference increased for the Heart+ App, showing a possible trend (p = 0.09). Post-pre differences in LF/HF for sham compared with the Heart+ App were also significant (p Heart+ App that was working in the background on an active smartphone untouched by the subjects. This may be the first RCT to show that specific frequencies of a purported non-Hertzian type of subtle energy conveyed by software applications broadcast from personal electronic devices can be bioactive and beneficially impact autonomic nervous system balance.

  9. Hydrodynamics of pronuclear migration

    Science.gov (United States)

    Nazockdast, Ehssan; Needleman, Daniel; Shelley, Michael

    2014-11-01

    Microtubule (MT) filaments play a key role in many processes involved in cell devision including spindle formation, chromosome segregation, and pronuclear positioning. We present a direct numerical technique to simulate MT dynamics in such processes. Our method includes hydrodynamically mediated interactions between MTs and other cytoskeletal objects, using singularity methods for Stokes flow. Long-ranged many-body hydrodynamic interactions are computed using a highly efficient and scalable fast multipole method, enabling the simulation of thousands of MTs. Our simulation method also takes into account the flexibility of MTs using Euler-Bernoulli beam theory as well as their dynamic instability. Using this technique, we simulate pronuclear migration in single-celled Caenorhabditis elegans embryos. Two different positioning mechanisms, based on the interactions of MTs with the motor proteins and the cell cortex, are explored: cytoplasmic pulling and cortical pushing. We find that although the pronuclear complex migrates towards the center of the cell in both models, the generated cytoplasmic flows are fundamentally different. This suggest that cytoplasmic flow visualization during pronuclear migration can be utilized to differentiate between the two mechanisms.

  10. Decoherent Histories and Hydrodynamic Equations

    CERN Document Server

    Halliwell, J J

    1998-01-01

    For a system consisting of a large collection of particles, a set of variables that will generally become effectively classical are the local densities (number, momentum, energy). That is, in the context of the decoherent histories approach to quantum theory, it is expected that histories of these variables will be approximately decoherent, and that their probabilites will be strongly peaked about hydrodynamic equations. This possibility is explored for the case of the diffusion of the number density of a dilute concentration of foreign particles in a fluid. It is shown that, for certain physically reasonable initial states, the probabilities for histories of number density are strongly peaked about evolution according to the diffusion equation. Decoherence of these histories is also shown for a class of initial states which includes non-trivial superpositions of number density. Histories of phase space densities are also discussed. The case of histories of number, momentum and energy density for more general...

  11. Integration of quantum hydrodynamical equation

    Science.gov (United States)

    Ulyanova, Vera G.; Sanin, Andrey L.

    2007-04-01

    Quantum hydrodynamics equations describing the dynamics of quantum fluid are a subject of this report (QFD).These equations can be used to decide the wide class of problem. But there are the calculated difficulties for the equations, which take place for nonlinear hyperbolic systems. In this connection, It is necessary to impose the additional restrictions which assure the existence and unique of solutions. As test sample, we use the free wave packet and study its behavior at the different initial and boundary conditions. The calculations of wave packet propagation cause in numerical algorithm the division. In numerical algorithm at the calculations of wave packet propagation, there arises the problem of division by zero. To overcome this problem we have to sew together discrete numerical and analytical continuous solutions on the boundary. We demonstrate here for the free wave packet that the numerical solution corresponds to the analytical solution.

  12. Description and development of the means of a model experiment for load balancing in distributed computing systems

    Science.gov (United States)

    Nagiyev, A. E.; Sherstnyova, A. I.; Botygin, I. A.; Galanova, N. Y.

    2016-06-01

    The results of the statistical model experiments research of various load balancing algorithms in distributed computing systems are presented. Software tools were developed. These tools, which allow to create a virtual infrastructure of distributed computing system in accordance with the intended objective of the research focused on multi-agent and multithreaded data processing were developed. A diagram of the control processing of requests from the terminal devices, providing an effective dynamic horizontal scaling of computing power at peak loads, is proposed.

  13. A Mass Balance Model for Designing Green Roof Systems that Incorporate a Cistern for Re-Use

    OpenAIRE

    Manoj Chopra; Martin Wanielista; Mike Hardin

    2012-01-01

    Green roofs, which have been used for several decades in many parts of the world, offer a unique and sustainable approach to stormwater management. Within this paper, evidence is presented on water retention for an irrigated green roof system. The presented green roof design results in a water retention volume on site. A first principle mass balance computer model is introduced to assist with the design of these green roof systems which incorporate a cistern to capture and reuse runoff waters...

  14. Equalizing resolution in smoothing particle hydrodynamics calculations using self-adaptive sinc kernels

    CERN Document Server

    García-Senz, Domingo; Escartín, José A; Ebinger, Kevin

    2014-01-01

    The smoothed particle hydrodynamics (SPH) technique is a numerical method for solving gas-dynamical problems that has been applied to simulate the evolution of a wide variety of astrophysical systems. The method has a second-order accuracy, with a resolution that is usually much larger in the compressed regions than in the diluted zones of the fluid. In this work, we propose and check a scheme to balance and equalize the resolution of SPH between high and low density regions. This method relies in the versatility of a family of interpolators called Sinc kernels, which allows to increase the quality of interpolations just varying a single parameter (the exponent of the Sinc function). The scheme is checked and validated through a number of numerical tests, going from standard one-dimensional Riemann problems in shock tubes, to multidimensional simulations of explosions, hydrodynamic instabilities and the collapse of a sun-like polytrope. The analysis of the hydrodynamical simulations suggests that the scheme d...

  15. Life cycle inventory and mass-balance of municipal food waste management systems: Decision support methods beyond the waste hierarchy.

    Science.gov (United States)

    Edwards, Joel; Othman, Maazuza; Crossin, Enda; Burn, Stewart

    2017-08-14

    When assessing the environmental and human health impact of a municipal food waste (FW) management system waste managers typically rely on the principles of the waste hierarchy; using metrics such as the mass or rate of waste that is 'prepared for recycling,' 'recovered for energy,' or 'sent to landfill.' These metrics measure the collection and sorting efficiency of a waste system but are incapable of determining the efficiency of a system to turn waste into a valuable resource. In this study a life cycle approach was employed using a system boundary that includes the entire waste service provision from collection to safe end-use or disposal. A life cycle inventory of seven waste management systems was calculated, including the first service wide inventory of FW management through kitchen in-sink disposal (food waste disposer). Results describe the mass, energy and water balance of each system along with key emissions profile. It was demonstrated that the energy balance can differ significantly from its' energy generation, exemplified by mechanical biological treatment, which was the best system for generating energy from waste but only 5(th) best for net-energy generation. Furthermore, the energy balance of kitchen in-sink disposal was shown to be reduced because 31% of volatile solids were lost in pre-treatment. The study also confirmed that higher FW landfill diversion rates were critical for reducing many harmful emissions to air and water. Although, mass-balance analysis showed that the alternative end-use of the FW material may still contain high impact pollutants. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  16. Skin Redox Balance Maintenance: The Need for an Nrf2-Activator Delivery System

    Directory of Open Access Journals (Sweden)

    Maya Ben-Yehuda Greenwald

    2016-01-01

    Full Text Available The skin, being the largest organ of the body, functions as a barrier between our body and the environment. It is consistently exposed to various exogenous and endogenous stressors (e.g., air pollutants, ionizing and non-ionizing irradiation, toxins, mitochondrial metabolism, enzyme activity, inflammatory process, etc. producing reactive oxygen species (ROS and physical damage (e.g., wounds, sunburns also resulting in reactive oxygen species production. Although skin is equipped with an array of defense mechanisms to counteract reactive oxygen species, augmented exposure and continued reactive oxygen species might result in excessive oxidative stress leading to many skin disorders including inflammatory diseases, pigmenting disorders and some types of cutaneous malignancy. The nuclear factor erythroid 2-related factor 2 (Nrf2 is an emerging regulator of cellular resistance and of defensive enzymes such as the phase II enzymes. Induction of the Keap1–Nrf2 pathway may have a beneficial effect in the treatment of a large number of skin disorders by stimulating an endogenous defense mechanism. However, prolonged and enhanced activation of this pathway is detrimental and, thus, limits the therapeutic potential of Keap1–Nrf2 modulators. Here, we review the consequences of oxidative stress to the skin, and the defense mechanisms that skin is equipped with. We describe the challenges of maintaining skin redox balance and its impact on skin status and function. Finally, we suggest a novel strategy for maintenance of skin redox homeostasis by modulating the Keap1–Nrf2 pathway using nanotechnology-based delivery systems.

  17. Waste assay and mass balance for the decontamination and volume reduction system at LANL

    Energy Technology Data Exchange (ETDEWEB)

    Gruetzmacher, Kathleen M.; Ferran, Scott G.; Garner, Scott E.; Romero, Mike J.; Christensen, Davis V.; Bustos, Roland M.

    2003-07-01

    The Decontamination and Volume Reduction System (DVRS) operated by the Solid Waste Operations (SWO) Group at Los Alamos National Laboratory (LANL) processes large volume, legacy radioactive waste items. Waste boxes, in sizes varying from 4 ft x 4 ft x 8 ft to 10 ft x 12 ft x 40 ft, are assayed prior to entry into the processing building. Inside the building, the waste items are removed from their container, decontaminated and/or size reduced if necessary, and repackaged for shipment to the Waste Isolation Pilot Plant (WIPP) or on-site low-level waste disposal. The repackaged items and any secondary waste produced (e.g., personal protective equipment) are assayed again at the end of the process and a mass balance is done to determine whether there is any significant hold-up material left in the DVRS building. The DVRS building is currently classed as a radiological facility, with a building limit of 0.52 Ci of Pu239 and Am241, and 0.62 Ci of Pu238, the most common radionuclides processed. This requires tight controls on the flow of nuclear material. The large volume of the initial waste packages, the (relatively) small amounts of radioactive material in them, and the tight ceiling on the building inventory require accurate field measurements of the nuclear material. This paper describes the radioactive waste measurement techniques, the computer modeling used to determine the amount of nuclear material present in a waste package, the building inventory database, and the DVRS process itself. Future plans include raising the limit on the nuclear material inventory allowed in the building to accommodate higher activity waste packages. All DOE sites performing decontamination and decommissioning of radioactive process equipment face challenges related to waste assay and inventory issues. This paper describes an ongoing operation, incorporating lessons learned over the life of the project to date.

  18. Benchmarking Non-Hardware Balance of System (Soft) Costs for U.S. Photovoltaic Systems Using a Data-Driven Analysis from PV Installer Survey Results

    Energy Technology Data Exchange (ETDEWEB)

    Ardani, K.; Barbose, G.; Margolis, R.; Wiser, R.; Feldman, D.; Ong, S.

    2012-11-01

    This report presents results from the first U.S. Department of Energy (DOE) sponsored, bottom-up data-collection and analysis of non-hardware balance-of-system costs--often referred to as 'business process' or 'soft' costs--for residential and commercial photovoltaic (PV) systems.

  19. On the convexity of Relativistic Hydrodynamics

    CERN Document Server

    Ibáñez, José María; Martí, José María; Miralles, Juan Antonio; 10.1088/0264-9381/30/5/057002

    2013-01-01

    The relativistic hydrodynamic system of equations for a perfect fluid obeying a causal equation of state is hyperbolic (Anile 1989 {\\it Relativistic Fluids and Magneto-Fluids} (Cambridge: Cambridge University Press)). In this report, we derive the conditions for this system to be convex in terms of the fundamental derivative of the equation of state (Menikoff and Plohr 1989 {\\it Rev. Mod. Phys.} {\\bf 61} 75). The classical limit is recovered.

  20. Perceptions of Nebraska Teachers Regarding the Transition from STARS to NeSA and Its Perceived Influence on the Implementation of a Balanced Assessment System

    Science.gov (United States)

    Isom, Jamie

    2012-01-01

    The purpose of this explanatory mixed methods study was to explore the perceptions of Nebraska teachers about their experiences in the transition from STARS to NeSA. The study explored their perceptions of the influence of the transition on implementation of a balanced assessment system. As defined by NDE, a balanced system included NeSA testing,…

  1. Simplification of heating systems by omitting circulating pumps and differential pressure regulating valves. Balancing; Vereinfachung durch Einsparung von Umwaelzpumpen und Differenzdruckregler. Hydraulischer Abgleich

    Energy Technology Data Exchange (ETDEWEB)

    Gebauer, Marc [Baelz W. und Sohn GmbH und Co., Berlin (Germany)

    2011-07-01

    Balancing of heating systems today is possible without differential pressure regulating valves. Only the design basis volume flow is adjusted at the sectioning valve of the heating section, while the part-load behaviour is regulated accurately via thermal power regulation. This simplifies balancing, and the total efficiency of systems will be better than with the commonly used differential pressure regulating valves.

  2. Fluctuations in Relativistic Causal Hydrodynamics

    CERN Document Server

    Kumar, Avdhesh; Mishra, Ananta P

    2013-01-01

    The formalism to calculate the hydrodynamics fluctuation using the quasi-stationary fluctuation theory of Onsager to the relativistic Navier-Stokes hydrodynamics is already known. In this work we calculate hydrodynamic fluctuations in relativistic causal theory of Muller, Israel and Stewart and other related causal hydrodynamic theories. We show that expressions for the Onsager coefficients and the correlation functions have form similar to the ones obtained by using Navier-Stokes equation. However, temporal evolution of the correlation functions obtained using MIS and the other causal theories can be significantly different than the correlation functions obtained using the Navier-Stokes equation. Finally, as an illustrative example, we explicitly plot the correlation functions obtained using the causal-hydrodynamics theories and compare them with correlation functions obtained by earlier authors using the expanding boost-invariant (Bjorken) flows.

  3. Gradient expansion for anisotropic hydrodynamics

    CERN Document Server

    Florkowski, Wojciech; Spaliński, Michał

    2016-01-01

    We compute the gradient expansion for anisotropic hydrodynamics. The results are compared with the corresponding expansion of the underlying kinetic-theory model with the collision term treated in the relaxation time approximation. We find that a recent formulation of anisotropic hydrodynamics based on an anisotropic matching principle yields the first three terms of the gradient expansion in agreement with those obtained for the kinetic theory. This gives further support for this particular hydrodynamic model as a good approximation of the kinetic-theory approach. We further find that the gradient expansion of anisotropic hydrodynamics is an asymptotic series, and the singularities of the analytic continuation of its Borel transform indicate the presence of non-hydrodynamic modes.

  4. Lifshitz Superfluid Hydrodynamics

    CERN Document Server

    Chapman, Shira; Oz, Yaron

    2014-01-01

    We construct the first order hydrodynamics of quantum critical points with Lifshitz scaling and a spontaneously broken symmetry. The fluid is described by a combination of two flows, a normal component that carries entropy and a super-flow which has zero viscosity and carries no entropy. We analyze the new transport effects allowed by the lack of boost invariance and constrain them by the local second law of thermodynamics. Imposing time-reversal invariance, we find eight new parity even transport coefficients. The formulation is applicable, in general, to any superfluid/superconductor with an explicit breaking of boost symmetry, in particular to high $T_c$ superconductors. We discuss possible experimental signatures.

  5. Hydrodynamics of Ship Propellers

    DEFF Research Database (Denmark)

    Breslin, John P.; Andersen, Poul

    This book deals with flows over propellers operating behind ships, and the hydrodynamic forces and moments which the propeller generates on the shaft and on the ship hull.The first part of the text is devoted to fundamentals of the flow about hydrofoil sections (with and without cavitation......) and about wings. It then treats propellers in uniform flow, first via advanced actuator disc modelling, and then using lifting-line theory. Pragmatic guidance is given for design and evaluation of performance, including the use of computer modelling.The second part covers the development of unsteady forces...... arising from operation in non-uniform hull wakes. First, by a number of simplifications, various aspects of the problem are dealt with separately until the full problem of a non-cavitating, wide-bladed propeller in a wake is treated by a new and completely developed theory. Next, the complicated problem...

  6. Hydrodynamic dispersion within porous biofilms

    KAUST Repository

    Davit, Y.

    2013-01-23

    Many microorganisms live within surface-associated consortia, termed biofilms, that can form intricate porous structures interspersed with a network of fluid channels. In such systems, transport phenomena, including flow and advection, regulate various aspects of cell behavior by controlling nutrient supply, evacuation of waste products, and permeation of antimicrobial agents. This study presents multiscale analysis of solute transport in these porous biofilms. We start our analysis with a channel-scale description of mass transport and use the method of volume averaging to derive a set of homogenized equations at the biofilm-scale in the case where the width of the channels is significantly smaller than the thickness of the biofilm. We show that solute transport may be described via two coupled partial differential equations or telegrapher\\'s equations for the averaged concentrations. These models are particularly relevant for chemicals, such as some antimicrobial agents, that penetrate cell clusters very slowly. In most cases, especially for nutrients, solute penetration is faster, and transport can be described via an advection-dispersion equation. In this simpler case, the effective diffusion is characterized by a second-order tensor whose components depend on (1) the topology of the channels\\' network; (2) the solute\\'s diffusion coefficients in the fluid and the cell clusters; (3) hydrodynamic dispersion effects; and (4) an additional dispersion term intrinsic to the two-phase configuration. Although solute transport in biofilms is commonly thought to be diffusion dominated, this analysis shows that hydrodynamic dispersion effects may significantly contribute to transport. © 2013 American Physical Society.

  7. Non standard hydrodynamics for cosmological K-fluids

    CERN Document Server

    Diez-Tejedor, A; Diez-Tejedor, Alberto; Feinstein, Alexander

    2005-01-01

    We consider hydrodynamics with non conserved number of particles and show that it can be modeled with effective fluid Lagrangians which explicitly depend on the velocity potentials. For such theories, the {}``shift symetry'' $\\phi\\to\\phi+$const. leading to the conserved number of fluid particles in conventional hydrodynamics is globaly broken and, as a result, the non conservation of particle number appears as a source term in the continuity equation. The particle number non-conservation is balanced by the entropy change, with both the entropy and the source term expresed in terms of the fluid velocity potential. Equations of hydrodynamics are derived using a modified version of Schutz's variational principle method. Examples of fluids described by such Lagrangians (tachyon condensate, k-essence) in spatially flat isotropic universe are briefly discussed.

  8. Application of new novel energy balance method to strongly nonlinear oscillator systems

    Directory of Open Access Journals (Sweden)

    Md. Abdur Razzak

    2015-01-01

    Full Text Available In this paper, a new novel energy balance method based on the harmonic balance method is proposed to obtain higher-order approximations of strongly nonlinear problems arising in engineering. Especially, second-order approximation is considered in this paper. Results found in this paper are compared with the exact result and other existing results. The results show that the proposed method gives better result for both small and large amplitudes of oscillation than other existing results. The method is illustrated by examples. It has been shown that the proposed method is very effective, convenient and quite accurate to nonlinear engineering problems.

  9. Effects of a Passive Online Software Application on Heart Rate Variability and Autonomic Nervous System Balance

    Science.gov (United States)

    2017-01-01

    . This may be the first RCT to show that specific frequencies of a purported non-Hertzian type of subtle energy conveyed by software applications broadcast from personal electronic devices can be bioactive and beneficially impact autonomic nervous system balance. PMID:28051874

  10. Stability improvement of a four cable-driven parallel manipulator using a center of mass balance system

    Science.gov (United States)

    Salafian, Iman; Stewart, Blake; Newman, Matthew; Zygielbaum, Arthur I.; Terry, Benjamin

    2017-04-01

    A four cable-driven parallel manipulator (CDPM), consisting of sophisticated spectrometers and imagers, is under development for use in acquiring phenotypic and environmental data over an acre-sized crop field. To obtain accurate and high quality data from the instruments, the end effector must be stable during sensing. One of the factors that reduces stability is the center of mass offset of the end effector, which can cause a pendulum effect or undesired tilt angle. The purpose of this work is to develop a system and method for balancing the center of mass of a 12th-scale CDPM to minimize vibration that can cause error in the acquired data. A simple method for balancing the end effector is needed to enable end users of the CDPM to arbitrarily add and remove sensors and imagers from the end effector as their experiments may require. A Center of Mass Balancing System (CMBS) is developed in this study which consists of an adjustable system of weights and a gimbal for tilt mitigation. An electronic circuit board including an orientation sensor, wireless data communication, and load cells was designed to validate the CMBS. To measure improvements gained by the CMBS, several static and dynamic experiments are carried out. In the experiments, the dynamic vibrations due to the translational motion and static orientation were measured with and without CMBS use. The results show that the CMBS system improves the stability of the end-effector by decreasing vibration and static tilt angle.

  11. A Vibrotactile and Plantar Force Measurement-Based Biofeedback System: Paving the Way towards Wearable Balance-Improving Devices

    Directory of Open Access Journals (Sweden)

    Christina Zong-Hao Ma

    2015-12-01

    Full Text Available Although biofeedback systems have been used to improve balance with success, they were confined to hospital training applications. Little attempt has been made to investigate the use of in-shoe plantar force measurement and wireless technology to turn hospital training biofeedback systems into wearable devices. This research developed a wearable biofeedback system which detects body sway by analyzing the plantar force and provides users with the corresponding haptic cues. The effects of this system were evaluated in thirty young and elderly subjects with simulated reduced foot sensation. Subjects performed a Romberg test under three conditions: (1 no socks, system turned-off; (2 wearing five layers of socks, system turned-off; (3 wearing five layers of socks, and system turned-on. Degree of body sway was investigated by computing the center of pressure (COP movement measured by a floor-mounted force platform. Plantar tactile sensation was evaluated using a monofilament test. Wearing multiple socks significantly decreased the plantar tactile sensory input (p < 0.05, and increased the COP parameters (p < 0.017, indicating increased postural sway. After turning on the biofeedback system, the COP parameters decreased significantly (p < 0.017. The positive results of this study should inspire future development of wearable plantar force-based biofeedback systems for improving balance in people with sensory deficits.

  12. Discussing Feedback System Thinking in Relation to Scenario Evaluation in a Balanced Scorecard Setup

    DEFF Research Database (Denmark)

    Nielsen, Steen; Nielsen, Erland Hejn

    2012-01-01

    Since the emergence of the Balanced Scorecard (BSC) at the beginning of the 1990s, literature has intensively discussed the problems of the cause and effect relationships, the time-delay elements between measures and perspectives and the concepts of feedback loops. This paper focuses on the use...

  13. New Real-Time Market Facilitating Demand-Side Resources for System Balancing

    DEFF Research Database (Denmark)

    Feng, Donghan; Nyeng, Preben; Xie, Jun

    2011-01-01

    the participation of demand-side resources. In light of the future environment of increasing intermittent renewable power and distributed energy/storage resources, stochastic time-series and Monte-Carlo simulation are used to analyze the relationship between balancing requirement and generation/demand uncertainties...

  14. Impact of different disassembly line balancing algorithms on the performance of dynamic kanban system for disassembly line

    Science.gov (United States)

    Kizilkaya, Elif A.; Gupta, Surendra M.

    2005-11-01

    In this paper, we compare the impact of different disassembly line balancing (DLB) algorithms on the performance of our recently introduced Dynamic Kanban System for Disassembly Line (DKSDL) to accommodate the vagaries of uncertainties associated with disassembly and remanufacturing processing. We consider a case study to illustrate the impact of various DLB algorithms on the DKSDL. The approach to the solution, scenario settings, results and the discussions of the results are included.

  15. Method for achieving hydraulic balance in typical Chinese building heating systems by managing differential pressure and flow

    DEFF Research Database (Denmark)

    Zhang, Lipeng; Xia, Jianjun; Thorsen, Jan Eric;

    2017-01-01

    Hydraulic unbalance is a common problem in Chinese district heating (DH) systems. Hydraulic unbalance has resulted in poor flow distribution among heating branches and overheating of apartments. Studies show that nearly 30% of the total heat supply is being wasted in Chinese DH systems due...... to a lack of pressure and flow control. This study investigated using pre-set radiator valves combined with differential pressure (DP) controllers to achieve hydraulic balance in building distribution systems, and consequently save energy and reduce the emissions. We considered a multi-storey building...

  16. From hyperbolic regularization to exact hydrodynamics for linearized Grad's equations.

    Science.gov (United States)

    Colangeli, Matteo; Karlin, Iliya V; Kröger, Martin

    2007-05-01

    Inspired by a recent hyperbolic regularization of Burnett's hydrodynamic equations [A. Bobylev, J. Stat. Phys. 124, 371 (2006)], we introduce a method to derive hyperbolic equations of linear hydrodynamics to any desired accuracy in Knudsen number. The approach is based on a dynamic invariance principle which derives exact constitutive relations for the stress tensor and heat flux, and a transformation which renders the exact equations of hydrodynamics hyperbolic and stable. The method is described in detail for a simple kinetic model -- a 13 moment Grad system.

  17. Applicability of the hydrodynamic description of classical fluids

    CERN Document Server

    Mithen, James P; Gregori, Gianluca

    2010-01-01

    We investigate using numerical simulations the domain of applicability of the hydrodynamic description of classical fluids at and near equilibrium. We find this to be independent of the degree of many-body correlations in the system; the range r_c of the microscopic interactions completely determines the maximum wavenumber k_{max} at which the hydrodynamic description is applicable by k_{max}r_c ~ 0.43. For the important special case of the Coulomb potential of infinite range, we show that the ordinary hydrodynamic description is never valid.

  18. A Vibrotactile and Plantar Force Measurement-Based Biofeedback System: Paving the Way towards Wearable Balance-Improving Devices.

    Science.gov (United States)

    Ma, Christina Zong-Hao; Wan, Anson Hong-Ping; Wong, Duo Wai-Chi; Zheng, Yong-Ping; Lee, Winson Chiu-Chun

    2015-12-15

    Although biofeedback systems have been used to improve balance with success, they were confined to hospital training applications. Little attempt has been made to investigate the use of in-shoe plantar force measurement and wireless technology to turn hospital training biofeedback systems into wearable devices. This research developed a wearable biofeedback system which detects body sway by analyzing the plantar force and provides users with the corresponding haptic cues. The effects of this system were evaluated in thirty young and elderly subjects with simulated reduced foot sensation. Subjects performed a Romberg test under three conditions: (1) no socks, system turned-off; (2) wearing five layers of socks, system turned-off; (3) wearing five layers of socks, and system turned-on. Degree of body sway was investigated by computing the center of pressure (COP) movement measured by a floor-mounted force platform. Plantar tactile sensation was evaluated using a monofilament test. Wearing multiple socks significantly decreased the plantar tactile sensory input (p wearable plantar force-based biofeedback systems for improving balance in people with sensory deficits.

  19. Chaos in hydrodynamic BL Herculis models

    CERN Document Server

    Smolec, R

    2014-01-01

    We present non-linear, convective, BL Her-type hydrodynamic models that show complex variability characteristic for deterministic chaos. The bifurcation diagram reveals a rich structure, with many phenomena detected for the first time in hydrodynamic models of pulsating stars. The phenomena include not only period doubling cascades en route to chaos (detected in earlier studies) but also periodic windows within chaotic band, type-I and type-III intermittent behaviour, interior crisis bifurcation and others. Such phenomena are known in many textbook chaotic systems, from the simplest discrete logistic map, to more complex systems like Lorenz equations. We discuss the physical relevance of our models. Although except of period doubling such phenomena were not detected in any BL Her star, chaotic variability was claimed in several higher luminosity siblings of BL Her stars - RV Tau variables, and also in longer-period, luminous irregular pulsators. Our models may help to understand these poorly studied stars. Pa...

  20. Special Relativistic Hydrodynamics with Gravitation

    Science.gov (United States)

    Hwang, Jai-chan; Noh, Hyerim

    2016-12-01

    Special relativistic hydrodynamics with weak gravity has hitherto been unknown in the literature. Whether such an asymmetric combination is possible has been unclear. Here, the hydrodynamic equations with Poisson-type gravity, considering fully relativistic velocity and pressure under the weak gravity and the action-at-a-distance limit, are consistently derived from Einstein’s theory of general relativity. An analysis is made in the maximal slicing, where the Poisson’s equation becomes much simpler than our previous study in the zero-shear gauge. Also presented is the hydrodynamic equations in the first post-Newtonian approximation, now under the general hypersurface condition. Our formulation includes the anisotropic stress.