WorldWideScience

Sample records for additional external forces

  1. Matching Games with Additive Externalities

    Branzei, Simina; Michalak, Tomasz; Rahwan, Talal;

    2012-01-01

    fully expressive representations of externalities in matchings require exponential space, in this paper we propose a compact model of externalities, in which the influence of a match on each agent is computed additively. In this framework, we analyze many-to-many and one-to-one matchings under neutral...

  2. Dynamics of Autonomous Systems with External Forces

    We consider a geometric framework for analytical mechanics with external forces. Four versions of this framework are considered. A variational principle with boundary terms and external forces. The second and the third versions are the Lagrangian and Hamiltonian formulations, respectively. The last one is the Poisson formulation. An extensive introductory section presents some well known and some little known geometric constructions to put our formulation in the appropriate setting to make the comparison of the different formulations more easy. (author)

  3. Proprioception is Robust under External Forces

    Kuling, Irene A.; Eli Brenner; Smeets, Jeroen B. J.

    2013-01-01

    Information from cutaneous, muscle and joint receptors is combined with efferent information to create a reliable percept of the configuration of our body (proprioception). We exposed the hand to several horizontal force fields to examine whether external forces influence this percept. In an end-point task subjects reached visually presented positions with their unseen hand. In a vector reproduction task, subjects had to judge a distance and direction visually and reproduce the corresponding ...

  4. How cooperative systems respond to external forces

    Svenkeson, Adam

    Cooperative interactions permeate through nature, bringing about emergent behavior and complexity. Using a simple cooperative model, I illustrate the mean field dynamics that occur at the critical point of a second order phase transition in the framework of Langevin equations. Through this formalism I discuss the response, both linear and nonlinear, to external forces. Emphasis is placed on how information is transferred from one individual to another in order to facilitate the collective response of the cooperative network to a localized perturbation. The results are relevant to a wide variety of systems, ranging from nematic liquid crystals, to flocks and swarms, social groups, and neural networks.

  5. A Recent Approach Incorporating External Forces To Predict Nonstationary Processes

    WANG Ge-Li; YANG Pei-Cai

    2010-01-01

    Most real-world time series have some degree of nonstationarity due to external perturbations of the observed system; external driving forces are the essential reason that leads to the nonstationarity of dynamics system. In this paper, the authors present a novel technique in which the authors incorporate external forces to predict nonstationary time series. To test the effect, the authors also examined two prediction experiments with an ideal time series from a logistic map and a proxy climate data-set for the past millennium. The preliminary results show that the resulting algorithm has better predictive ability than the one that does not consider the external forces.

  6. External torsion and the electromagnetic force

    A definition of external torsion is given, under the assumption that at quantum level torsion be a propagating field, not rigidly fixed to spinning matter distribution as in the classical Einstein-Cartan theory. Moreover, the motion equations of a pole-particle in a Riemann-Cartan space are written, and a relation between external torsion and electromagnetic potential, valid for short range interactions only, is introduced. (author)

  7. External Forces Shaping the Future of the Insurance Industry

    Gregory V Serio

    2006-01-01

    The insurance industry is facing a number of serious issues from external forces, not the least of which has been a significant increase in regulatory and enforcement actions by American and international authorities. These forces have worked to compound challenges already confronting insurers in the underwriting, rating and claims settlement areas. However, it can be theorized that the external forces facing the industry are directly correlative to the internal issues as (1) these internal i...

  8. Equatorial Rossby Solitary Wave Under the External Forcing

    FU Zun-Tao; LIU Shi-Kuo; LIU Shi-Da

    2005-01-01

    A simple shallow-water model with influence of external forcing on a β-plane is applied to investigate the nonlinear equatorial Rossby waves in a shear flow. By the perturbation method, the extended variable-coefficient KdV equation under an external forcing is derived for large amplitude equatorial Rossby wave in a shear flow. And then various periodic-like structures for these equatorial Rossby waves are obtained with the help of Jacobi elliptic functions.It is shown that the external forcing plays an important role in various periodic-like structures.

  9. Numerical studies of a plasma diode with external forcing

    With reference to laboratory Q-machine studies we analyze the dynamics of a plasma diode under external forcing. Assuming a strong axial magnetic field, the problem is analyzed in one spatial dimension by a particle-in-cell code. The cathode is assumed to be operated in electron rich conditions, supplying an abundance of electrons. We compare different forcing schemes with the results obtained by solving the van der Pol equation. In one method of forcing we apply an oscillation in addition to the DC end plate bias and consider both amplitude and frequency variations. An alternative method of perturbation consists of modelling an absorbing grid at some internal position. Also in this case we can have a constant frequency with varying amplitude or alternatively an oscillation with chirped frequency but constant amplitude. We find that the overall features of the forced van der Pol equation are recovered, but the details in the plasma response need more attention to the harmonic responses, requiring extensions of the model equation. The analysis is extended by introducing collisional effects, where we emphasize charge exchange collisions of ions, since these processes usually have the largest cross sections and give significant modifications of the diode performance. In particular we find a reduction in oscillator frequency, although a linear scaling of the oscillation time with the system length remains also in this case.

  10. Numerical studies of a plasma diode with external forcing

    Rekaa, V. L.; Pécseli, H. L.; Trulsen, J. K.

    2012-08-01

    With reference to laboratory Q-machine studies we analyze the dynamics of a plasma diode under external forcing. Assuming a strong axial magnetic field, the problem is analyzed in one spatial dimension by a particle-in-cell code. The cathode is assumed to be operated in electron rich conditions, supplying an abundance of electrons. We compare different forcing schemes with the results obtained by solving the van der Pol equation. In one method of forcing we apply an oscillation in addition to the DC end plate bias and consider both amplitude and frequency variations. An alternative method of perturbation consists of modelling an absorbing grid at some internal position. Also in this case we can have a constant frequency with varying amplitude or alternatively an oscillation with chirped frequency but constant amplitude. We find that the overall features of the forced van der Pol equation are recovered, but the details in the plasma response need more attention to the harmonic responses, requiring extensions of the model equation. The analysis is extended by introducing collisional effects, where we emphasize charge exchange collisions of ions, since these processes usually have the largest cross sections and give significant modifications of the diode performance. In particular we find a reduction in oscillator frequency, although a linear scaling of the oscillation time with the system length remains also in this case.

  11. Stability of GOY Model Under Modulation of Periodic External Force

    ZHAO Ying-Kui; CHEN Shi-Gang; WANG Guang-Rui

    2008-01-01

    There is a phase transition between quasi-periodic state and intermittent chaos in GOY model with a critical value δ0. When we add a modulated periodic external force to the system, the phase transition can also be found with a critical value δe. Due to coupling between the force and the intrinsic fluctuation of the velocity on shells in GOY model, the stability of the system has been changed, which results in the variation of the critical value. For proper intensity and period of the force, δe is unequal to δ0. The critical value is a nonlinear function of amplitude of the force, and the fluctuation of the velocity can resonate with the external force for certain period Te.

  12. Soil carbon mineralization following biochar addition associated with external nitrogen

    Rudong Zhao

    2015-12-01

    Full Text Available Biochar has been attracting increasing attention for its potentials of C sequestration and soil amendment. This study aimed to understand the effects of combining biochar with additional external N on soil C mineralization. A typical red soil (Plinthudults was treated with two biochars made from two types of plantation-tree trunks (soil-biochar treatments, and was also treated with external N (soil-biochar-N treatments. All treatments were incubated for 42 d. The CO2-C released from the treatments was detected periodically. After the incubation, soil properties such as pH, microbial biomass C (MBC, and microbial biomass N (MBN were measured. The addition of biochar with external N increased the soil pH (4.31-4.33 compared to the soil treated with external N only (4.21. This was not observed in the comparison of soil-biochar treatments (4.75-4.80 to soil only (4.74. Biochar additions (whether or not they were associated with external N increased soil MBC and MBN, but decreased CO2-C value per unit total C (added biochar C + soil C according to the model fitting. The total CO2-C released in soil-biochar treatments were enhanced compared to soil only (i.e., 3.15 vs. 2.57 mg and 3.23 vs. 2.45 mg, which was attributed to the labile C fractions in the biochars and through soil microorganism enhancement. However, there were few changes in soil C mineralization in soil-biochar-N treatments. Additionally, the potentially available C per unit total C in soil-biochar-N treatments was lower than that observed in the soil-biochar treatments. Therefore, we believe in the short term, that C mineralization in the soil can be enhanced by biochar addition, but not by adding external N concomitantly.

  13. Entropic stochastic resonance without external force in oscillatory confined space

    We have studied the dynamics of Brownian particles in a confined geometry of dumbbell-shape with periodically oscillating walls. Entropic stochastic resonance (ESR) behavior, characterizing by a maximum value of the coherent factor Q at some optimal level of noise, is observed even without external periodic force in the horizontal direction, which is necessary for conventional ESR where the wall is static and the particle is subjected to the force. Interestingly, the ESR can be remarkably enhanced by the particle gravity G, in contrast to the conventional case. In addition, Q decreases (increases) with G in the small (large) noise limit, respectively, while it non-monotonically changes with G for moderate noise levels. We have applied an effective 1D coarsening description to illustrate such a nontrivial dependence on G, by investigating the property of the 1D effective potential of entropic nature and paying special attention to the excess part resulting from the boundary oscillation. Dependences of the ESR strength with other related parameters are also discussed

  14. Entropic stochastic resonance without external force in oscillatory confined space.

    Ding, Huai; Jiang, Huijun; Hou, Zhonghuai

    2015-05-21

    We have studied the dynamics of Brownian particles in a confined geometry of dumbbell-shape with periodically oscillating walls. Entropic stochastic resonance (ESR) behavior, characterizing by a maximum value of the coherent factor Q at some optimal level of noise, is observed even without external periodic force in the horizontal direction, which is necessary for conventional ESR where the wall is static and the particle is subjected to the force. Interestingly, the ESR can be remarkably enhanced by the particle gravity G, in contrast to the conventional case. In addition, Q decreases (increases) with G in the small (large) noise limit, respectively, while it non-monotonically changes with G for moderate noise levels. We have applied an effective 1D coarsening description to illustrate such a nontrivial dependence on G, by investigating the property of the 1D effective potential of entropic nature and paying special attention to the excess part resulting from the boundary oscillation. Dependences of the ESR strength with other related parameters are also discussed. PMID:26001449

  15. Entropic stochastic resonance without external force in oscillatory confined space

    Ding, Huai; Jiang, Huijun; Hou, Zhonghuai, E-mail: hzhlj@ustc.edu.cn [Department of Chemical Physics and Hefei National Laboratory for Physical Sciences at Microscales, iChEM, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2015-05-21

    We have studied the dynamics of Brownian particles in a confined geometry of dumbbell-shape with periodically oscillating walls. Entropic stochastic resonance (ESR) behavior, characterizing by a maximum value of the coherent factor Q at some optimal level of noise, is observed even without external periodic force in the horizontal direction, which is necessary for conventional ESR where the wall is static and the particle is subjected to the force. Interestingly, the ESR can be remarkably enhanced by the particle gravity G, in contrast to the conventional case. In addition, Q decreases (increases) with G in the small (large) noise limit, respectively, while it non-monotonically changes with G for moderate noise levels. We have applied an effective 1D coarsening description to illustrate such a nontrivial dependence on G, by investigating the property of the 1D effective potential of entropic nature and paying special attention to the excess part resulting from the boundary oscillation. Dependences of the ESR strength with other related parameters are also discussed.

  16. Manipulating single enzymes by an external harmonic force

    Lomholt, Michael A; Urbakh, Michael; Metzler, Ralf;

    2007-01-01

    We study a Michaelis-Menten reaction for a single two-state enzyme molecule, whose transition rates between the two conformations are modulated by an harmonically oscillating external force. In particular, we obtain a range of optimal driving frequencies for changing the conformation of the enzyme...

  17. External Force Estimation for Teleoperation Based on Proprioceptive Sensors

    Enrique del Sol

    2014-03-01

    Full Text Available This paper establishes an approach to external force estimation for telerobotic control in radioactive environments by the use of an identified manipulator model and pressure sensors, without employing a force/torque sensor. The advantages of - and need for - force feedback have been well-established in the field of telerobotics, where electrical and back-drivable manipulators have traditionally been used. This research proposes a methodology employing hydraulic robots for telerobotics tasks based on a model identification scheme. Comparative results of a force sensor and the proposed approach using a hydraulic telemanipulator are presented under different conditions. This approach not only presents a cost effective solution but also a methodology for force estimation in radioactive environments, where the dose rates limit the use of electronic devices such as sensing equipment.

  18. Ratchet effect on a relativistic particle driven by external forces

    Quintero, Niurka R [Departamento de Fisica Aplicada I, Escuela Universitaria Politecnica, Universidad de Sevilla, Calle Virgen de Africa 7, E-41011 Sevilla (Spain); Alvarez-Nodarse, Renato [Departamento de Analisis Matematico, Facultad de Matematicas, Universidad de Sevilla, Apdo 1160, E-41080 Sevilla (Spain); Cuesta, Jose A, E-mail: niurka@us.es, E-mail: ran@us.es, E-mail: cuesta@math.uc3m.es [Grupo Interdisciplinar de Sistemas Complejos (GISC), Departamento de Matematicas, Universidad Carlos III de Madrid, Avenida de la Universidad 30, E-28911 Leganes, Madrid (Spain)

    2011-10-21

    We study the ratchet effect of a damped relativistic particle driven by both asymmetric temporal bi-harmonic and time-periodic piecewise constant forces. This system can be formally solved for any external force, providing the ratchet velocity as a nonlinear functional of the driving force. This allows us to explicitly illustrate the functional Taylor expansion formalism recently proposed for this kind of systems. The Taylor expansion reveals particularly useful to obtain the shape of the current when the force is periodic, piecewise constant. We also illustrate the somewhat counterintuitive effect that introducing damping may induce a ratchet effect. When the force is symmetric under time-reversal and the system is undamped, under symmetry principles no ratchet effect is possible. In this situation increasing damping generates a ratchet current which, upon increasing the damping coefficient eventually reaches a maximum and decreases toward zero. We argue that this effect is not specific of this example and should appear in any ratchet system with tunable damping driven by a time-reversible external force. (paper)

  19. External forcing of the early 20th century Arctic warming

    Lingling Suo

    2013-12-01

    Full Text Available The observed Arctic warming during the early 20th century was comparable to present-day warming in terms of magnitude. The causes and mechanisms for the early 20th century Arctic warming are less clear and need to be better understood when considering projections of future climate change in the Arctic. The simulations using the Bergen Climate Model (BCM can reproduce the surface air temperature (SAT fluctuations in the Arctic during the 20th century reasonably well. The results presented here, based on the model simulations and observations, indicate that intensified solar radiation and a lull in volcanic activity during the 1920s–1950s can explain much of the early 20th century Arctic warming. The anthropogenic forcing could play a role in getting the timing of the peak warming correct. According to the model the local solar irradiation changes play a crucial role in driving the Arctic early 20th century warming. The SAT co-varied closely with local solar irradiation changes when natural external forcings are included in the model either alone or in combination with anthropogenic external forcings. The increased Barents Sea warm inflow and the anomalous atmosphere circulation patterns in the northern Europe and north Atlantic can also contribute to the warming. In summary, the early 20th century warming was largely externally forced.

  20. SIGNAL DETECTION OF GLOBAL CLIMATE CHANGE AND EXTERNAL FORCING FACTORS

    李晓东; 王在文; 侯章栓

    2001-01-01

    In this paper, we displayed one-dimensional climate signals, such as global temperature variation, Southern Oscillation Index and variation of external forcing factors, on a two-dimensional time-scale plane using compactly supported wavelet decomposition. Using the lag-correlation analysis method, and interpretative variance analysis method, and phase comparison method to the wavelet analysis result, we not only gained the variation on different scales to the global temperature and El Nino signals, the location of the jump point and intrinsic scale of these series, but also indicated the magnitude, extent and time of the effect of external forcing factors on them. We also put forward reasonable explanation to the main variation of recent 140 years.

  1. Transport and diffusion on crystalline surfaces under external forces

    We present a numerical study of classical particles obeying a Langevin equation and moving on a solid crystalline surface under an external force that may either be constant or modulated by periodic oscillations. We focus on the particle drift velocity and diffusion. The roles of friction and equilibrium thermal fluctuations are studied for two nonlinear dynamical regimes corresponding to low and to high but finite friction. We identify a number of resonances and antiresonances, and provide phenomenological interpretations of the observed behaviour

  2. Permeability of continental crust influenced by internal and external forcing

    Rojstaczer, S.A.; Ingebritsen, S.E.; Hayba, D.O.

    2008-01-01

    The permeability of continental crust is so highly variable that it is often considered to defy systematic characterization. However, despite this variability, some order has been gleaned from globally compiled data. What accounts for the apparent coherence of mean permeability in the continental crust (and permeability-depth relations) on a very large scale? Here we argue that large-scale crustal permeability adjusts to accommodate rates of internal and external forcing. In the deeper crust, internal forcing - fluxes induced by metamorphism, magmatism, and mantle degassing - is dominant, whereas in the shallow crust, external forcing - the vigor of the hydrologic cycle - is a primary control. Crustal petrologists have long recognized the likelihood of a causal relation between fluid flux and permeability in the deep, ductile crust, where fluid pressures are typically near-lithostatic. It is less obvious that such a relation should pertain in the relatively cool, brittle upper crust, where near-hydrostatic fluid pressures are the norm. We use first-order calculations and numerical modeling to explore the hypothesis that upper-crustal permeability is influenced by the magnitude of external fluid sources, much as lower-crustal permeability is influenced by the magnitude of internal fluid sources. We compare model-generated permeability structures with various observations of crustal permeability. ?? 2008 The Authors Journal compilation ?? 2008 Blackwell Publishing Ltd.

  3. Global precipitation response to changing external forcings since 1870

    A. Bichet

    2011-03-01

    Full Text Available Predicting and adapting to changes in the hydrological cycle is one of the major challenges for the twenty-first century. To better estimate how it will respond to future changes in climate forcings, it is crucial to understand how it has evolved in the past and why. In our study, we use an atmospheric global climate model with prescribed sea surface temperatures (SSTs to investigate how changing external climate forcings have affected global land temperature and precipitation in the period 1870–2005. We show that prescribed SSTs (encapsulating other forcings are the dominant forcing driving the decadal variability of land temperature and precipitation since 1870. On top of this SSTs forcing, we also find that the atmosphere-only response to increasing aerosol emissions is a reduction in global land temperature and precipitation by up to 0.4 °C and 30 mm year−1, respectively, between about 1930 and 2000. Similarly, the atmosphere-only response to increasing greenhouse gas concentrations is an increase in global land temperature and precipitation by up to 0.25 °C and 10 mm year−1, respectively, between about 1950 and 2000. Finally, our results also suggest that between about 1950 and 1970, increasing aerosol emissions had a larger impact on the hydrological cycle than increasing greenhouse gases concentrations.

  4. Stability of aerosol droplets in Bessel beam optical traps under constant and pulsed external forces

    We report on the dynamics of aerosol droplets in optical traps under the influence of additional constant and pulsed external forces. Experimental results are compared with simulations of the three-dimensional droplet dynamics for two types of optical traps, the counter-propagating Bessel beam (CPBB) trap and the quadruple Bessel beam (QBB) trap. Under the influence of a constant gas flow (constant external force), the QBB trap is found to be more stable compared with the CPBB trap. By contrast, under pulsed laser excitation with laser pulse durations of nanoseconds (pulsed external force), the type of trap is of minor importance for the droplet stability. It typically needs pulsed laser forces that are several orders of magnitude higher than the optical forces to induce escape of the droplet from the trap. If the droplet strongly absorbs the pulsed laser light, these escape forces can be strongly reduced. The lower stability of absorbing droplets is a result of secondary thermal processes that cause droplet escape

  5. Bifurcations of a lattice gas flow under external forcing

    The authors study the behavior of a Frisch-Hasslacher-Pomeau lattice gas automation under the effect of a spatially periodic forcing. It is shown that the lattice gas dynamics reproduces the steady-state features of the bifurcation pattern predicted by a properly truncated model of the Navier-Stokes equations. In addition, they show that the dynamical evolution of the instabilities driving the bifurcation can be modeled by supplementing the truncated Navier-Stokes equation with a random force chosen on the basis of the automation noise

  6. Nonlinear Development of Thermal Instability without External Forcing

    Koyama, H; Koyama, Hiroshi; Inutsuka, Shu-ichiro

    2006-01-01

    Supersonic turbulent motions are the remarkable properties of interstellar medium. Previous numerical simulations have demonstrated that the thermal instability in a shock-compressed layer produces the supersonic turbulent motion that does not decay. In this paper we focus on two- and three-dimensional numerical simulations of the non-linear development of simple thermal instability incorporating physical viscosity but without any external forcing, in order to isolate the effects of various processes responsible for the long-lasting turbulent motion. As the initial condition for our simulations, we set up spatially uniform gas with thermally unstable temperature in a box with periodic boundaries. After the linear growth stage of the thermal instability, two-phase medium forms where cold clumps are embedded in warm medium, and turbulent fluid flow clearly visible as translational motions of the cold clumps does not decay in a viscous dissipation timescale. The amplitude of the turbulent velocity increases when...

  7. Protein displacements under external forces: An atomistic Langevin dynamics approach

    Gnandt, David; Utz, Nadine; Blumen, Alexander; Koslowski, Thorsten

    2009-02-01

    We present a fully atomistic Langevin dynamics approach as a method to simulate biopolymers under external forces. In the harmonic regime, this approach permits the computation of the long-term dynamics using only the eigenvalues and eigenvectors of the Hessian matrix of second derivatives. We apply this scheme to identify polymorphs of model proteins by their mechanical response fingerprint, and we relate the averaged dynamics of proteins to their biological functionality, with the ion channel gramicidin A, a phosphorylase, and neuropeptide Y as examples. In an environment akin to dilute solutions, even small proteins show relaxation times up to 50 ns. Atomically resolved Langevin dynamics computations have been performed for the stretched gramicidin A ion channel.

  8. Effects of variation in external pulling force magnitude, elevation, and orientation on trunk muscle forces, spinal loads and stability.

    El Ouaaid, Z; Shirazi-Adl, A; Plamondon, A

    2016-04-11

    Nowadays in various daily, occupational and training activities, there are many occasions with forces supported in hands acting at various magnitudes, elevations, and orientations with substantial horizontal components. In this work, we aim to compute trunk muscle forces, stability, and spinal loads under pulling external forces applied at 3 elevations and 13 orientations. Under an identical upright standing posture and upper body weight, the trunk active-passive response is computed using a validated iterative finite element kinematics-driven model. Pulling forces of 80, 120, and 160N are resisted symmetrically in both hands held at 20, 40, and 60cm elevations above the L5-S1 and oriented each in upward (-90°), inclined upward (-75°, -60°, -45°, -30°, and -15°), horizontal (0°), inclined downward (15°, 30°, 45°, 60°, and 75°) and finally downward in gravity direction (90°). In addition, in all analyses, an antagonist moment of 10Nm is applied in order to generate rather small antagonist coactivity and intra-abdominal pressures of 8-12kPa are considered when abdominal muscles are active under upward pulling forces. Results demonstrated substantial differences in muscular response, spinal loads, and stability margin as the pulling force elevation, orientation, and magnitude altered. Compression and shear forces at lower lumbar levels peaked under forces at higher elevations acting with downward inclinations. Minimum spinal forces were computed at all elevations under pulling forces in the upward direction. Trunk stability was also maximum under these latter forces pulling upward. These findings have important consequences in rehabilitation, training, and design of safer occupational activities. PMID:26475220

  9. Resonance in Defect Turbulence under Periodic External Force

    QIAO Chun; FENG Xiao-Bo; WANG Hong-Li; OUYANG Qi

    2007-01-01

    The periodically forced spatially extended Brusselator is investigated in the chaotic regime. We explore resonant or non-resonant patterns generated under various forcing frequencies and forcing amplitudes. Resonant spatially uniform oscillation and irregular structures are found. Furthermore two types of regular spatial patterns are generated under appropriate parameters. Our results of numerical simulations demonstrate that periodic force can give rise to resonant patterns in forced systems of spatiotemporal chaos similar to the situation of forced systems of regular oscillations.

  10. Measurement by load cells of impact force which a human body receives by external force

    Y. Ito

    2008-05-01

    Full Text Available Purpose: By development of a robotics technique, the assisted living instruments which have intelligent functions are being developed. As a result, there is a possibility that the accident to which the assisted living instrument under actuation contacts a human body may occur. The purpose of this research is for the impact force measurement system which with load cells to build, and to evaluate performance.Design/methodology/approach: The impact force measurement system was built by load cells and a data logger. Evaluation of the performance of the system was carried out to static loads and dynamic loads.Findings: By covering the sensor part of load cells with shock absorbing material, it turned out that it is possible to measure impact load simple. Moreover, as a result of comparing the characteristic of shock absorbing material, it became clear that the impact-absorbing characteristic of cell sponge and organism soft tissue is in agreement.Research limitations/implications: This research estimated the impact-absorbing characteristic of organism soft tissue for the skin, fat, muscles, etc. as a complex.Practical implications: This paper cleared that the load which a bone receives by dynamic external force can be easily measured by load cells.Originality/value: The objective of this research project was to develop the system by which impact force is measured and evaluated based on the damage which a human body receives. And we were able to complete the prototype.

  11. Defect localization in fibre-reinforced composites by computing external volume forces from surface sensor measurements

    We suggest a prospective method for detecting and visualizing defects in fibre-reinforced composites by computing external volume forces from measurements acquired by sensors that are integrated on the surface of the structure. Anisotropic materials like carbon fibre-reinforced composites are widely used in light weight construction which can exhibit damages that are not optically detectable. The key idea of our method is the interpretation of defects in such structures as if they were induced by an external volume force. This idea is based on the observation that a propagating elastic wave interferes with a damaged area by reflecting the wave. In that sense a damage can be seen as an additional source. Thus identifying the external volume force which has caused this wave is supposed to reveal the location of the defect. This approach leads to the inverse problem of determining the inhomogeneity of a hyperbolic initial-boundary value problem. We tackle this ill-posed problem by minimizing a Tikhonov functional which takes the oberservation points of our surface measurements into account. In the article we address the solvability of the direct problem, state and analyze the PDE-based optimization problem that aims for computing the external force and develop a numerical realization of its solution using the conjugate gradient method. First numerical results for a simple model case with different sensor adjustments show that the defects in fact are detectable. In that sense this article might be seen as starting point of future research which should comprehend deeper numerical studies and analysis of the problem. (paper)

  12. Thermal denaturation of Peyrard-Bishop's DNA model with external force

    Sulaimana, A; Alatas, H; Handoko, L T

    2011-01-01

    The impact of external force to Peyrard-Bishop DNA denaturation is investigated through statistical mechanics approach. The partition function is obtained using transfer integral method, and further the stretching of hydrogen bond is calculated using time independent perturbation method. It is shown that the external force accelerates the denaturation processes at lower temperature

  13. Convergence Rates to Stationary Solutions of a Gas-liquid Model with External Forces and Vacuum

    FAN Long; Liu, Qingqing; Zhu, Changjiang

    2011-01-01

    In this paper, we study the asymptotic behavior of solutions to a Gas-liquid model with external forces and general pressure law. Under some suitable assumptions on the initial date and $\\gamma>1$, if $\\theta\\in(0,\\frac{\\gamma}{2}]\\cap(0,\\gamma-1]\\cap(0,1-\\alpha\\gamma]$, we prove the weak solution $(cQ(x,t),u(x,t))$ behavior asymptotically to the stationary one by adapting and modifying the technique of weighted estimates. In addition, if $\\theta\\in(0,\\frac{\\gamma}{2}]\\cap(0,\\gamma-1)\\cap(0,1...

  14. Dynamics of DNA breathing in the Peyrard-Bishop model with damping and external force

    Sulaiman, A; Alatas, H; Handoko, L T

    2011-01-01

    The impact of damping effect and external forces to the DNA breathing is investigated within the Peyrard-Bishop model. In in the continuum limit, the dynamics of the breathing of DNA is described by the forced-damped nonlinear Schrodinger equation and studied by means of variational method. The analytical solutions are obtained for special cases. It is shown that the breather propagation is decelerated in the presence of damping factor without the external force, while the envelope velocity and the amplitude increase significantly with the presence of external force. It is particularly found that the higher harmonic terms are enhanced when the periodic force is applied. It is finally argued that the external force accelerates the DNA breathing.

  15. Lower ionosphere response to external forcing: A brief review

    Laštovička, Jan

    2009-01-01

    Roč. 43, č. 1 (2009), s. 1-14. ISSN 0273-1177 R&D Projects: GA ČR GA205/07/1367; GA ČR GA205/08/1356 Institutional research plan: CEZ:AV0Z30420517 Keywords : lower ionosphere * space weather forcing * solar activity * solar forcing * atmospheric waves * atmospheric forcing Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 1.079, year: 2009

  16. Lower ionosphere response to external forcing: A review (solicited)

    Laštovička, Jan

    Montreal : National research council, 2008. -. ISSN 1815-2619. [COSPAR Scientific Assembly /37./. 13.08.2008-20.08.2008, Montreal] Institutional research plan: CEZ:AV0Z30420517 Keywords : lower ionosphere * forcing from above * forcing from below Subject RIV: DG - Athmosphere Sciences, Meteorology

  17. Additive CHARMM force field for naturally occurring modified ribonucleotides.

    Xu, You; Vanommeslaeghe, Kenno; Aleksandrov, Alexey; MacKerell, Alexander D; Nilsson, Lennart

    2016-04-15

    More than 100 naturally occurring modified nucleotides have been found in RNA molecules, in particular in tRNAs. We have determined molecular mechanics force field parameters compatible with the CHARMM36 all-atom additive force field for all these modifications using the CHARMM force field parametrization strategy. Emphasis was placed on fine tuning of the partial atomic charges and torsion angle parameters. Quantum mechanics calculations on model compounds provided the initial set of target data, and extensive molecular dynamics simulations of nucleotides and oligonucleotides in aqueous solutions were used for further refinement against experimental data. The presented parameters will allow for computational studies of a wide range of RNAs containing modified nucleotides, including the ribosome and transfer RNAs. © 2016 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc. PMID:26841080

  18. External Forced Convection Enhancement using a Corona Discharge

    Go, David B.; Maturana, Raul A.; Fisher, Timothy S.; Garimella, Suresh V.

    2007-01-01

    An ionic wind is formed when air ions generated by a corona discharge are accelerated by an electric field and exchange momentum with neutral air molecules, causing air flow. Because ionic winds can generate flow with no moving parts, they offer an attractive method for enhancing the heat transfer from a surface that would otherwise only be cooled by natural convection and/or radiation. In the presence of an external, flat plate flow, ionic winds distort the boundary layer such that local hea...

  19. Musculoskeletal modelling of muscle activation and applied external forces for the correction of scoliosis

    Curtin, Maurice; Lowery, Madeleine M.

    2014-01-01

    Background This study uses biomechanical modelling and computational optimization to investigate muscle activation in combination with applied external forces as a treatment for scoliosis. Bracing, which incorporates applied external forces, is the most popular non surgical treatment for scoliosis. Non surgical treatments which make use of muscle activation include electrical stimulation, postural control, and therapeutic exercises. Electrical stimulation has been largely dismissed as a viabl...

  20. Approximate Kelvin-Voigt Fluid Driven by an External Force Depending on Velocity with Distributed Delay

    Yantao Guo

    2015-01-01

    Full Text Available We consider the approximate 3D Kelvin-Voigt fluid driven by an external force depending on velocity with distributed delay. We investigate the long time behavior of solutions to Navier-Stokes-Voigt equation with a distributed delay external force depending on the velocity of fluid on a bounded domain. By a prior estimate and a contractive function, we give a sufficient condition for the existence of pullback attractor of NSV equation.

  1. Recent drying of the Fertile Crescent: natural or externally forced?

    Kelley, Colin

    2014-05-01

    There has been a reduction in observed precipitation over the greater Mediterranean region since the middle of the 20th Century. Recent studies suggest that while anthropogenic forcing has already begun to assert itself in recent decades, the preponderance of the winter drying trend is attributable to the large natural multidecadal variability of the North Atlantic Oscillation (NAO), while over the eastern Mediterranean, the anthropogenic, or forced drying signal is more clearly evident. This forced drying is projected to increase during the 21st Century according to the newest global climate models and this aridification would present significant challenges for a region that is already water-stressed. Although the Fertile Crescent is historically known for its agricultural prosperity, the severity and persistence of the recent multiyear drought in Syria, directly prior to the 2011 uprising there, leads us to ask whether this is evidence of emerging global warming influence. This drought exacerbated existing water insecurity, resulting in an agricultural collapse and a mass migration of rural drought refugees to the urban areas in Syria's west. This migration followed the previous influx of Iragi refugees and combined with strong natural population growth to place a severe strain on resources. Here we examine observations of precipitation and temperature, both gridded and stations, along with simulations and projections from the newest global climate models, to estimate the forced contribution to the recent Syrian drought, and assess the uncertainty in future drying according to the models. We find that this region has experienced a long-term downward trend in precipitation, and a concomitant increase in temperature, serving to further dry the soil, and in surface pressure. We find that the shift in the distributions of three-year running means of surface pressure and precipitation due to the forcing make severe events such as the recent Syrian drought several

  2. Oscillating Propagation of Kink in Nondissipative Frenkel-Kontorova Chain Due to External DC Force

    ZENG Shang-You; TANG Yi; REN Xi-Mei; ZHAO De-Jiang

    2009-01-01

    We report the oscillating propagation of kink in a nondissipative Frenkel-Kontorova (FK) chain driven by external DC force, which is different from the usual propagation of localized modes with equal speed. When the kink moves in the opposite direction of the external DC force, the kink will be accelerated and the potential of the FK chain in the external force field is transformed to be the kinetic energy of the kink. If the kink reaches the boundary of the FK chain, the kink will be bounced back and moves in the opposite direction, then the kink will be decelerated gradually and the kinetic energy of the kink is transformed to be the potential of the FK chain in the external force field. If the speed of the kink reaches zero, the kink will move in the opposite direction again driven by the external DC force, and a new oscillating cycle begins. Simulation result demonstrates exactly the transformation between the kinetic energy of the kink and the potential of the FK chain in the external force field. The interesting energy exchange is induced by the special topology of kinks, and other localized modes, such as breathers and envelope solitons, have no the interesting phenomenon.

  3. The additive and interactive effects of parenting and children's personality on externalizing behaviour

    Prinzie, P; Onghena, P; Hellinckx, W; Grietens, H; Ghesquiere, P; Colpin, H

    2003-01-01

    Parenting practices have been previously linked to childhood externalizing behaviour However little attention has been given to the potential effect of individual personality differences among children on this relation. The current study assesses the additive effects of children's personality charac

  4. Euler-Poincaré Reduction of Externally Forced Rigid Body Motion

    Wisniewski, Rafal; Kulczycki, P.

    2004-01-01

    If a mechanical system experiences symmetry, the Lagrangian becomes invariant under a certain group action. This property leads to substantial simplification of the description of movement. The standpoint in this article is a mechanical system affected by an external force of a control action...... control system generates an external force, which may break the symmetry in the dynamics. This paper shows how to model and to control a mechanical system on the reduced phase space, such that complete state space asymptotic stabilization can be achieved. The paper comprises a specialization of the well......-known Euler-Poincaré reduction to a rigid body motion with forcing....

  5. Convergence Rates to Stationary Solutions of a Gas-liquid Model with External Forces and Vacuum

    Fan, Long; Zhu, Changjiang

    2011-01-01

    In this paper, we study the asymptotic behavior of solutions to a Gas-liquid model with external forces and general pressure law. Under some suitable assumptions on the initial date and $\\gamma>1$, if $\\theta\\in(0,\\frac{\\gamma}{2}]\\cap(0,\\gamma-1]\\cap(0,1-\\alpha\\gamma]$, we prove the weak solution $(cQ(x,t),u(x,t))$ behavior asymptotically to the stationary one by adapting and modifying the technique of weighted estimates. In addition, if $\\theta\\in(0,\\frac{\\gamma}{2}]\\cap(0,\\gamma-1)\\cap(0,1-\\alpha\\gamma]$, following the same idea in \\cite{Fang-Zhang4}, we estimate the stabilization rate of the solution as time tends to infinity in the sense of $L^\\infty$ norm.

  6. The importance of external climate forcing for the variability and trends of coastal upwelling in past and future climate

    Tim, Nele; Zorita, Eduardo; Hünicke, Birgit; Yi, Xing; Emeis, Kay-Christian

    2016-06-01

    The eastern boundary upwelling systems, located in the subtropics at the eastern boundary of the Atlantic and Pacific oceans and mainly driven by the trade winds, are the major coastal upwelling regions. Previous studies have suggested that the intensity of upwelling in these areas in the past centuries may have been influenced by the external radiative forcing, for instance by changes in solar irradiance, and it will also be influenced in the future by the increasing atmospheric greenhouse gases. Here, we analyse the impact of the external climate forcing on these upwelling systems in ensembles of simulations of two Earth system models. The ensembles contain three simulations for each period covering the past millennium (900-1849) and the 20th century (1850-2005). One of these Earth system models additionally includes the near future (2006-2100). Using a set of simulations, differing only in their initial conditions, enables us to test whether the observed variability and trends are driven by the external radiative forcing. Our analysis shows that the variability of the simulated upwelling is largely not affected by the external forcing and that, generally, there are no significant trends in the periods covering the past and future. Only in future simulations with the strongest increase of greenhouse gas concentrations the upwelling trends are significant and appear in all members of the ensemble.

  7. Evidence for external forcing temporal clustering of great earthquakes

    Khachikyan, Galina; Zhumabayev, Beibit; Toyshiev, Nursultan; Kairatkyzy, Dina; Kaldybayev, Azamat; Nurakynov, Serik

    2016-04-01

    It is shown by Bufe and Perkins [2005, BSSA, doi:10.1785/0120040110] and Shearera and Stark [2012, PNAS, doi: 10.1073/pnas.1118525109] that clustering of great earthquakes in 1950-1965 and 2004-2011 years is highly significant, with a 0.5% probability of random occurrence. Lutikov and Rogozhin [2014, Physics of the Solid Earth] reported on a similar clustering in the end of 19th - beginning of 20ty centuries as well, when strongest earthquakes occurred in Tien Shan (1889, M=8.3; and 1911, M=8.2); Alaska (1899, M=8.0); Kashgaria (1902, M=8.2); Mongolia (1905, M=8.2); San Francisco (1906, M=8.3), China(1906, M=8.3); Columbia (1906, M=8.6). Shearera and Stark [2012] have found that clustering of great earthquakes is analogous to seismic swarms that occur for a limited time. Simultaneously, they mentioned that at present no physical mechanism has been proposed to explain possible global seismicity swarms. Our results suggest that a mechanism responsible for temporal clustering of great earthquakes could be an external one related to the processes in the whole solar system including the Sun. We pay attention that the three marked periods of great earthquake clustering are related closely to the extreme phases of the recent Solar Centennial Gleissberg Cycle, which minimums occurred around of 1913 and 2008 years, and maximum - around of 1960 year. In particular, the great earthquake clustering in 1950-1965 coincides closely with the extremely high 19th eleven year solar cycle lasting from February 1954 to October 1964, while a great earthquake clustering after 2004 year coincides closely with the recent prolonged solar minimum developing after 2000 year. Also, we demonstrate that depending on the structure and composition of the lithosphere, strongest earthquakes may prefer to occur either in high or low solar activity. In particular, data analysis for 32 strongest (M=>7.0) earthquakes occurred in 1973-2014 years in the orogeny region of Eurasia, restricted by coordinates

  8. DIGIT FORCE ADJUSTMENTS DURING FINGER ADDITION/REMOVAL IN MULTI-DIGIT PREHENSION

    Budgeon, Mark K.; Mark L. Latash; Zatsiorsky, Vladimir M.

    2008-01-01

    We explored adjustments in multi-digit coordinated action on a hand-held object with finger addition and removal. The subjects (n= 7) kept a vertically oriented handle at rest using a prismatic grasp as if holding a glass of liquid and then either added one finger to the grasp—the index (I) or little (L) finger—or removed one finger. Three external torques were applied on the apparatus: clockwise, counterclockwise, and no torque. The individual digit forces and moments were recorded with 6-co...

  9. Impacts of external forcing on the 20th century global warming

    2007-01-01

    The impacts of external forcing, including natural and anthropogenic, on the 20th century global warming were assessed with the use of the Grid Atmospheric Model of IAP/LASG Version 1.1.0, following the standard coordinated experiment design of the Climate Variability and Predictability (CLIVAR) International Climate of the Twentieth Century Project (C20C), Phase II. The results indicate that external forcing plays an important role in the evolution of the land surface air temperature on interannual, decadal, and interdecadal time scales, and contributes greatly to the global warming in the following two periods: the early twentieth century between the 1910s and the 1940s and the late twentieth century after the 1970s. External forcing also has strong impact on the regional temperature change during the two warming periods except for parts of the Eurasia and the North America continents. In the cooling period, however, the impact of internal variability is dominant.

  10. The roles of external forcing and natural variability in global warming hiatuses

    Zhang, Lei

    2016-02-01

    Global mean surface temperature (GMST) rising has slowed down since late 1990s, which is referred to as the global warming hiatus. There was another global warming hiatus event during 1940s-1960s. The roles of the external forcing and the natural variability in both global warming hiatuses are explored, using EOF analysis. The first two leading EOF modes of the 5-year running mean global sea surface temperature (SST) reflect the global warming scenario (EOF1) and the interdecadal Pacific oscillation (IPO)-like natural variability (EOF2), respectively. In observation, PC2 was in its positive phase (eastern Pacific cooling) during 1940s-1960s, which contributed to the previous warming hiatus. In addition, GMST trends are found to be negative during late 1950s and 1960s in most of the CMIP5 historical runs, which implies that the external forcing also contributed to the pause in the GMST rising. It is further demonstrated that it is the natural radiative forcing (volcanic forcing) that caused the drop-down of GMST in 1960s. The current global warming hiatus has been attributed to the eastern Pacific cooling/enhanced Pacific trade winds. It is shown that the PC2 switched to its positive phase in late 1990s, and hence the IPO-like natural variability made a contribution to the slowdown of GMST rising in the past decade. It is also found that the EOF1 mode (global warming mode) of the observed SST features a smaller warming in tropical Pacific compared to the Indian Ocean and the tropical Atlantic. Such inter-basin warming contrast, which is attributed to the "ocean thermostat" mechanism, has been suggested to contribute to the intensification of Pacific trade winds since late 1990s as well. Global warming hiatuses are also found in the future projections from CMIP5 models, and the spatial pattern of the SST trends during the warming-hiatus periods exhibits an IPO-like pattern, which resembles the observed SST trends since late 1990s.

  11. External force back-projective composition and globally deformable optimization for 3-D coronary artery reconstruction

    The clinical value of the 3D reconstruction of a coronary artery is important for the diagnosis and intervention of cardiovascular diseases. This work proposes a method based on a deformable model for reconstructing coronary arteries from two monoplane angiographic images acquired from different angles. First, an external force back-projective composition model is developed to determine the external force, for which the force distributions in different views are back-projected to the 3D space and composited in the same coordinate system based on the perspective projection principle of x-ray imaging. The elasticity and bending forces are composited as an internal force to maintain the smoothness of the deformable curve. Second, the deformable curve evolves rapidly toward the true vascular centerlines in 3D space and angiographic images under the combination of internal and external forces. Third, densely matched correspondence among vessel centerlines is constructed using a curve alignment method. The bundle adjustment method is then utilized for the global optimization of the projection parameters and the 3D structures. The proposed method is validated on phantom data and routine angiographic images with consideration for space and re-projection image errors. Experimental results demonstrate the effectiveness and robustness of the proposed method for the reconstruction of coronary arteries from two monoplane angiographic images. The proposed method can achieve a mean space error of 0.564 mm and a mean re-projection error of 0.349 mm. (paper)

  12. Changes in kinematics, metabolic cost and external work during walking with a forward assistive force.

    Zirker, Christopher A; Bennett, Bradford C; Abel, Mark F

    2013-08-01

    We examined how the application of a forward horizontal force applied at the waist alters the metabolic cost, kinematics, and external work of gait. Horizontal assist forces of 4%, 8% and 12% of a subject's body weight were applied via our testing apparatus while subjects walked at comfortable walking speed on a level treadmill. Kinematic and metabolic parameters were measured using motion capture and ergospirometry respectively on a group of 10 healthy male subjects. Changes in kinematic and metabolic parameters were quantified and found similar to walking downhill at varying grades. A horizontal assist force of 8% resulted in the greatest reduction of metabolic cost. Changes in recovery factor, external work, and center of mass (COM) movement did not correlate with changes in metabolic rate and therefore were not driving the observed reductions in cost. The assist force may have performed external work by providing propulsion as well as raising the COM as it pivots over the stance leg. Assist forces may decrease metabolic cost by reducing the concentric work required for propulsion while increasing the eccentric work of braking. These findings on the effects of assist forces suggest novel mobility aids for individuals with gait disorders and training strategies for athletes. PMID:23183216

  13. Inhomogeneous similarity solutions of the Boltzmann equation with confining external forces

    The Nikolskii transform makes it possible to construct inhomogeneous solutions of the Boltzmann equation from homogeneous ones. These solutions correspond to a gas in expansion, but if the authors introduce external forces, they can relax toward absolute Maxwellians. This property holds independently of the assumed intermolecular inverse power force. Consequently, for Maxwell molecules and from energy-dependent homogeneous distributions, they construct effectively a class of inhomogeneous similarity distributions with Maxwellian equilibrium relaxation. They review and investigate again the homogeneous distributions which can be written in closed form, for instance, they show that an elliptic exact solution proposed some years ago violates positivity. For Maxwell interaction with singular cross sections, they numerically construct inhomogeneous distributions having Maxwellian equilibrium states and study the Tjon overshoot effect. They show that both the sign and the time decrease of the external force as well as the microscopic model of the cross section contribute to the asymptotic behavior of the distribution. These inhomogeneous similarity solutions include a class of distributions that asymptotically oscillate between different Maxwellians. Two classes of external forces are considered: linear spatial-dependent forces or linear velocity-dependent forces plus source term

  14. Externalities

    Verhoef Erik T.

    1997-01-01

    This paper discusses the concept of ‘externalities ‘. It starts with a brief discussion of market failures in the neoclassical economic framework. It then proceeds to a definition of externalities, thereby distinguishing external effects from other sorts of ‘unpriced effects ‘. Finally, some attention is paid to the relation, and tension, between efficiency and equity impacts of externalities.

  15. Real-Time Control of Humanoid Robots Considering External Forces on Upper Part of the Body

    Inomata, Kentaro; Shigemori, Yo; Uchimura, Yutaka

    Recently, the demand for the practical use of service robots has risen significantly because of acceleration of demographic aging, and a humanoid robot is one of the promising form factors of service robots. When a humanoid robot is used by a human in a real environment, the robot needs to be designed by taking into account the various external forces that act on the robot. Thus far, most of the walking humanoid robots have been mainly controlled by the conventional ZMP method to maintain a stable walking posture. However, the conventional ZMP method can not be used to handle the various external forces that act on the upper part of the humanoid robot body. To overcome these problems, in this paper, we propose a novel control method, which we called 3DZMP and pZMP, for a humanoid robot to react to the external force on the upper part of the body. The 3DZMP is defined as the point in three-dimensional space at which the moment about all axes is zero. 3DZMP can prevent the rotation of a humanoid robot. The pZMP is defined as the point corresponding to the orthographic projection of the 3DZMP on a plane. pZMP is used to evaluate the stability of 3DZMP. We implemented the proposed method on a prototype robot and verified that the robot gained the capability to react to external forces that could not be handled by the conventional ZMP method.

  16. A piecewise-integration method for simulating the influence of external forcing on climate

    Zhifu Zhang; Chongjian Qiu; Chenghai Wang

    2008-01-01

    Climate drift occurs in most general circulation models (GCMs) as a result of incomplete physical and numerical representation of the complex climate system,which may cause large uncertainty in sensitivity experiments evaluating climate response to changes in external forcing.To solve this problem,we propose a piecewise-integration method to reduce the systematic error in climate sensitivity studies.The observations are firstly assimilated into a numerical model by using the dynamic relaxation technique to relax to the current state of atmosphere,and then the assimilated fields are continuously used to reinitialize the simulation to reduce the error of climate simulation.When the numerical model is integrated with changed external forcing,the results can be split into two parts,background and perturbation fields,and the background is the state before the external forcing is changed.The piecewise-integration method is used to continuously reinitialize the model with the assimilated field,instead of the background.Therefore,the simulation error of the model with the external forcing can be reduced.In this way,the accuracy of climate sensitivity experiments is greatly improved.Tests with a simple low-order spectral model show that this approach can significantly reduce the uncertainty of climate sensitivity experiments.

  17. Angular and Linear Accelerations of a Rolling Cylinder Acted by an External Force

    Oliveira, V.

    2011-01-01

    The dynamics of a cylinder rolling on a horizontal plane acted on by an external force applied at an arbitrary angle is studied with emphasis on the directions of the acceleration of the centre-of-mass and the angular acceleration of the body. If rolling occurs without slipping, there is a relationship between the directions of these…

  18. Fluctuation-Induced Interactions in external magnetic fields: Casimir force and Radiative Heat Transfer

    Esquivel-Sirvent, Raul

    Thermally induced electromagnetic fields give rise to the Casimir force and the near field heat transfer between two bodies separated by a gap. These phenomena are described by Rytova's theory of fluctuating electromagnetic fields and both the Casimir force and the near field heat transfer depend on the local dielectric function of the bodies. In this work we present a theoretical calculation on the modulation of fluctuation-induced interactions in the presence of an external magnetic field. The system consists of two parallel plates separated by a gap d. Each plate is isotropic and has a local dielectric function. Applying an external magnetic field parallel to the plates, in the so called Voigt configuration, the plates become anisotropic. In particular, we consider plates of InSb. For the Casimir force the two plates are kept at the same temperature and the external field reduces the magnitude of the force. Similarly if the two plates are kept at different temperature the near field radiative heat transfer is modulated by the magnitude of the external magnetic field. The results are extended to semiconducting quantum wells. In both cases, the excitation of magnetoplasmons provides an explanation for the observed effect.

  19. Materials Bound by Non-Chemical Forces: External Fields and the Quantum Vacuum

    Swain, John; Srivastava, Yogendra

    2014-01-01

    We discuss materials which owe their stability to external fields. These include: 1) external electric or magnetic fields, and 2) quantum vacuum fluctuations in these fields induced by suitable boundary conditions (the Casimir effect). Instances of the first case include the floating water bridge and ferrofluids in magnetic fields. An example of the second case is taken from biology where the Casimir effect provides an explanation of the formation of stacked aggregations or "rouleaux" by negatively charged red blood cells. We show how the interplay between electrical and Casimir forces can be used to drive self-assembly of nano-structured materials, and could be generalized both as a probe of Casimir forces and as a means of manufacturing nanoscale structures. Interestingly, all the cases discussed involve the generation of the somewhat exotic negative pressures. We note that very little is known about the phase diagrams of most materials in the presence of external fields other than those represented by the ...

  20. Foraging at the Edge of Chaos: Internal Clock versus External Forcing

    Nicolis, S. C.; Fernández, J.; Pérez-Penichet, C.; Noda, C.; Tejera, F.; Ramos, O.; Sumpter, D. J. T.; Altshuler, E.

    2013-06-01

    Activity rhythms in animal groups arise both from external changes in the environment, as well as from internal group dynamics. These cycles are reminiscent of physical and chemical systems with quasiperiodic and even chaotic behavior resulting from “autocatalytic” mechanisms. We use nonlinear differential equations to model how the coupling between the self-excitatory interactions of individuals and external forcing can produce four different types of activity rhythms: quasiperiodic, chaotic, phase locked, and displaying over or under shooting. At the transition between quasiperiodic and chaotic regimes, activity cycles are asymmetrical, with rapid activity increases and slower decreases and a phase shift between external forcing and activity. We find similar activity patterns in ant colonies in response to varying temperature during the day. Thus foraging ants operate in a region of quasiperiodicity close to a cascade of transitions leading to chaos. The model suggests that a wide range of temporal structures and irregularities seen in the activity of animal and human groups might be accounted for by the coupling between collectively generated internal clocks and external forcings.

  1. Stochastic resonance of a damped oscillator with frequency fluctuation driven by a periodic external force

    Considering a damped linear oscillator model subjected to a white noise with an inherent angular frequency and a periodic external driving force, we derive the analytic expression of the first moment of output response, and study the stochastic resonance phenomenon in a system. The results show that the output response of this system behaves as a simple harmonic vibration, of which the frequency is the same as the external driving frequency, and the variations of amplitude with the driving frequency and the inherent frequency present a bona fide stochastic resonance. (general)

  2. Stochastic resonance of a damped oscillator with frequency fluctuation driven by a periodic external force

    Zhang Ling-Ying; Jin Guo-Xiang; Cao Li; Wang Zhi-Yun

    2012-01-01

    Considering a damped linear oscillator model subjected to a white noise with an inherent angular frequency and a periodic external driving force,we derive the analytic expression of the first moment of output response,and study the stochastic resonance phenomenon in a system.The results show that the output response of this system behaves as a simple harmonic vibration,of which the frequency is the same as the external driving frequency,and the variations of amplitude with the driving frequency and the inherent frequency present a bona fide stochastic resonance.

  3. Current Inversion in a Temperature Ratchet with Asymmetric Unbiased External Forces

    AI Bao-Quan; XIE Hui-Zhang; LIU Liang-Gang

    2005-01-01

    @@ Transport ofa Brownian particle moving in a symmetric potential is investigated in the presence of an asymmetricunbiased external force. The viscous medium is alternately in contact with the two heat reservoirs. We presentthe analytical expression of the net current at the quasi-steady state limit. It is found that the competition of thetemporal asymmetric parameter of the driving force with the temperature difference leads to current reversals.The competition between the two opposite driving factors is a necessary but not a sufficient condition for currentreversals.

  4. External Periodic Force Control of a Single-Degree-of-Freedom Vibroimpact System

    Jingyue Wang

    2013-01-01

    Full Text Available A single-degree-of-freedom mechanical model of vibro-impact system is established. Bifurcation and chaos in the system are revealed with the time history diagram, phase trajectory map, and Poincaré map. According to the bifurcation and chaos of the actual vibro-impact system, the paper puts forward external periodic force control strategy. The method of controlling chaos by external periodic force feedback controller is developed to guide chaotic motions towards regular motions. The stability of the control system is also analyzed especially by theory. By selecting appropriate feedback coefficients, the unstable periodic orbits of the original chaotic orbit can be stabilized to the stable periodic orbits. The effectiveness of this control method is verified by numerical simulation.

  5. Stability of Global Solution to Boltzmann-Enskog Equation with External Force

    JIANG ZHENG-LU; MA LI-JUN; YAO ZHENG-AN

    2012-01-01

    In the presence of external forces depending only on the time and space variables,the Boltzmann-Enskog equation formally conserves only the mass of the system,and its entropy functional is also nonincreasing.Corresponding to this type of equation,we first give some hypotheses of its bicharacteristic equations and then get some results about the stablity of its global solution with the help of two new Lyapunov functionals:one is to describe interactions between particles with different velocities and the other is to measure the L1 distance between two mild solutions.The former Lyapunov functional yields the time-asymptotic convergence of global classical solutions to the collision free motion while the latter is applied into the verification of the L1 stability of global mild solutions to the Boltzmann-Enskog equation for a moderately or highly dense gas in the influence of external forces.

  6. Angular and linear accelerations of a rolling cylinder acted by an external force

    Oliveira, V, E-mail: voliveira@isel.ipl.pt [Instituto Superior Engenharia de Lisboa, Avenida Conselheiro Emidio Navarro no 1, 1959-007 Lisboa (Portugal)

    2011-03-15

    The dynamics of a cylinder rolling on a horizontal plane acted on by an external force applied at an arbitrary angle is studied with emphasis on the directions of the acceleration of the centre-of-mass and the angular acceleration of the body. If rolling occurs without slipping, there is a relationship between the directions of these accelerations. If the linear acceleration points to the right, then the angular acceleration is clockwise. On the other hand, if it points to the left, then the angular acceleration is counterclockwise. In contrast, if rolling and slipping occurs, the direction of the linear acceleration does not determine the direction of the angular acceleration. For example, the linear acceleration may point to the right and the angular acceleration clockwise or counterclockwise depending on the external force orientation and point of application.

  7. Secondary resonance magnetic force microscopy using an external magnetic field for characterization of magnetic thin films

    Liu, Dongzi; Mo, Kangxin; Ding, Xidong; Zhao, Liangbing; Lin, Guocong; Zhang, Yueli; Chen, Dihu

    2015-09-01

    A bimodal magnetic force microscopy (MFM) that uses an external magnetic field for the detection and imaging of magnetic thin films is developed. By applying the external modulation magnetic field, the vibration of a cantilever probe is excited by its magnetic tip at its higher eigenmode. Using magnetic nanoparticle samples, the capacity of the technique which allows single-pass imaging of topography and magnetic forces is demonstrated. For the detection of magnetic properties of thin film materials, its signal-to-noise ratio and sensitivity are demonstrated to be superior to conventional MFM in lift mode. The secondary resonance MFM technique provides a promising tool for the characterization of nanoscale magnetic properties of various materials, especially of magnetic thin films with weak magnetism.

  8. Resonance and frequency-locking phenomena in spatially extended phytoplankton–zooplankton system with additive noise and periodic forces

    It is known that natural systems are undeniably subject to random fluctuations, arising from either environmental variability or internal effects. In this paper, we present a spatial version of the phytoplankton–zooplankton model that includes some important factors such as external periodic forces, noise, and diffusion processes. The spatially extended phytoplankton–zooplankton system is from the original study by Scheffer (Scheffer 1991 Oikos 62 271). Our results show that the spatially extended system exhibits a resonant pattern and frequency-locking phenomena. The system also shows that the noise and the external periodic forces play a constructive role in the Scheffer's model: (i) the noise can enhance the oscillation of phytoplankton species' density and form large clusters in space when the noise intensity is within a certain interval; (ii) the external periodic forces can induce 4:1 and 1:1 frequency-locking and spatially homogeneous oscillation phenomena to appear; and (iii) resonant patterns are observed in the system when the spatial noises and external periodic forces are both turned on. Moreover, we find that the 4:1 frequency locking transforms into 1:1 frequency locking when the noise intensity is increased. In addition to elucidating our results outside the domain of Turing instability, we provide further analysis of linear stability with the help of numerical calculation using the Maple software. Significantly, oscillations are enhanced in the system when the noise term is present. These results indicate that the oceanic plankton bloom may be partly due to interplay between the stochastic factors and external forces instead of deterministic factors. These results also may help us to understand the effects arising from the undeniable susceptibility to random fluctuations in oceanic plankton bloom

  9. OPTIMAL CONVERGENCE RATES OF LANDAU EQUATION WITH EXTERNAL FORCING IN THE WHOLE SPACE

    Yang Tong; Yu Hongjun

    2009-01-01

    In this paper, we combine the method of constructing the compensating func-tion introduced by Kawashima and the standard energy method for the study on the Landau equation with external forcing. Both the global existence of solutions near the time asymptotic states which are local Maxwellians and the optimal convergence rates are obtained. The method used here has its own advantage for this kind of studies because it does not involve the spectrum analysis of the corresponding linearized operator.

  10. Quantifying internally generated and externally forced climate signals at regional scales in CMIP5 models

    Lyu, Kewei; Zhang, Xuebin; Church, John A.; Hu, Jianyu

    2015-11-01

    The Earth's climate evolves because of both internal variability and external forcings. Using Coupled Model Intercomparison Project Phase 5 (CMIP5) models, here we quantify the ratio of externally forced variance to total variance on interannual and longer time scales for regional surface air temperature (SAT) and sea level, which depends on the relative strength of externally forced signal compared to internal variability. The highest ratios are found in tropical areas for SAT but at high latitudes for sea level over the historical period when ocean dynamics and global mean thermosteric contributions are considered. Averaged globally, the ratios over a fixed time interval (e.g., 30 years) are projected to increase during the 21st century under the business-as-usual scenario (RCP8.5). In contrast, under two mitigation scenarios (RCP2.6 and RCP4.5), the ratio declines sharply by the end of the 21st century for SAT, but only declines slightly or stabilizes for sea level, indicating a slower response of sea level to climate mitigation.

  11. The importance of ENSO Nonlinearities in Tropical Pacific Response to External Forcing.

    Karamperidou, Christina; Jin, Fei-Fei

    2016-04-01

    Tropical Pacific climate variability operates at multiple timescales: from seasonal to interannual to decadal and centennial; climate model simulations are inconclusive as to the direction and magnitude of changes at these distinct timescales in response to external forcing, and their potential interactions. While the impact that centennial-scale changes in tropical Pacific climate might have on decadal variability and ENSO activity has been extensively investigated, the reverse question -how ENSO activity affects decadal and centennial Pacific climate variability- has received limited attention. It has been shown that large ENSO events may warm the cold tongue at decadal and centennial scales via residual nonlinear dynamical heating, and they may influence the sensitivity of the tropical Pacific zonal SST gradient to external forcing (ENSO rectification hypothesis). Then the question becomes: do models exaggerate or mute forced tropical Pacific warming based on what kind of ENSO they simulate? What is the dominant balance of feedbacks that creates ENSO nonlinearities, and does it affect model projections of decadal tropical Pacific climate variability? Here, we use instrumental and paleoclimate data, as well as climate model simulations to investigate whether ENSO nonlinearities and rectification play a role in creating the inter-model spread of decadal & centennial tropical Pacific climate projections. We show that models that exhibit strong ENSO nonlinearities simulate a more accurate balance of ENSO feedbacks, which includes ENSO rectification processes. In these models, the response of decadal tropical Pacific variability to external forcing is tied to their ENSO response, and the projected tropical Pacific SST warming pattern is more uniform along the equator. On the contrary, climate models with weak ENSO nonlinearities may overestimate the warming of the cold tongue, in the absence of strong thermodynamic damping and ENSO rectification processes that would

  12. Additional force field in cooling process of cellular Al alloy

    ZHENG; Mingjun(郑明军); HE; Deping(何德坪); DAI; Ge(戴戈)

    2002-01-01

    The foaming process of Al alloy is similar to that of Al, but there is a solid-liquid state zone in the solidification process of cellular Al alloy which does not exist in the case of Al. In the unidirectional solidification of cellular Al alloy, the proportion of the solid phase gradually reduces from the solid front to the liquid front. This will introduce a force and result in a serious quick shrinkage. By the mathematic and physical mode, the solidification of the cellular Al alloy is studied. The data measured by experiment are close to the result calculated by the mode. This kind of shrinkage can be solved by suitable cooling method in appropriate growth stage. The compressive strength of the cellular Al alloy made by this way is 40% higher than that of cellular Al.

  13. Wave-based control of under-actuated flexible structures with strong external disturbing forces

    O'Connor, William J.; Habibi, Hossein

    2015-09-01

    Wave-based control of under-actuated, flexible systems has many advantages over other methods. It considers actuator motion as launching a mechanical wave into the flexible system which it absorbs on its return to the actuator. The launching and absorbing proceed simultaneously. This simple, intuitive idea leads to robust, generic, highly efficient, precise, adaptable controllers, allowing rapid and almost vibrationless re-positioning of the system, using only sensors collocated at the actuator-system interface. It has been very successfully applied to simple systems such as mass-spring strings, systems of Euler-Bernoulli beams, planar mass-spring arrays, and flexible three-dimensional space structures undergoing slewing motion. In common with most other approaches, this work also assumed that, during a change of position, the forces from the environment were negligible in comparison with internal forces and torques. This assumption is not always valid. Strong external forces considerably complicate the flexible control problem, especially when unknown, unexpected or unmodelled. The current work extends the wave-based strategy to systems experiencing significant external disturbing forces, whether enduring or transient. The work also provides further robustness to sensor errors. The strategy has the controller learn about the disturbances and compensate for them, yet without needing new sensors, measurements or models beyond those of standard wave-based control.

  14. Temperature response to external forcing in simulations and reconstructions of the last millennium

    L. Fernández-Donado

    2012-08-01

    Full Text Available The understanding of natural climate variability and its driving factors is crucial to assess future climate change. Therefore, comparing proxy-based climate reconstructions with forcing factors as well as comparing these with paleoclimate model simulations is key to gain insights into the relative roles of internal versus forced variability. A review of the state of modeling of the last millennium climate previous to the CMIP5-PMIP3 coordinated effort is presented and compared to the available temperature reconstructions. Simulations and reconstructions broadly agree on reproducing the major temperature changes and suggest an overall linear response to external forcing on multidecadal or longer timescales. Internal variability is found to have an important influence at hemispheric and global scales. The spatial distribution of simulated temperature changes during the transition of the Medieval Climate Anomaly to the Little Ice Age disagrees with that found in the reconstructions, thus advocating for internal variability as a possible major player in shaping temperature changes through the millennium.

    A paleo transient climate response (PTCR is defined to provide a quantitative framework for analysing the consistency between simulated and reconstructed climate. Beyond an overall agreement between simulated and reconstructed PTCR ranges, this analysis is able to single out specific discrepancies between some reconstructions and the ensemble of simulations. The disagreement is found in the cases where the reconstructions show reduced covariability with external forcings or when they present high rates of temperature change.

  15. Denitrification potential enhancement by addition of external carbon sources in a pre-denitrification process

    PENG Yong-zhen; MA Yong; WANG Shu-ying

    2007-01-01

    The aim of this study is to investigate the denitrification potential enhancement by addition of external carbon sources and to estimate the denitrification potential for the predenitrification system using nitrate utilization rate(NUR)batch tests.It is shown that the denitrification potential Can be substantially increased with the addition of three external carbon sources,i.e.methanol,ethanol,and acetate.and the denitrification rates of ethanol,acetate,and methanol reached up to 9.6,12,and 3.2 mgN/(gVSS·h),respectively,while mat of starch wastewater was only 0.74 mgN/(gVSS·h).By comparison,ethanol was found to be the best extemal carbon source.NUR batch tests with starch wastewater and waste ethanol were carried out.The denitrification potential increased from 5.6 to 16.5 mg NO.-N/L owing to waste ethanol addition.By means of NUR tests,the wastewater characteristics and kinetic parameters can be estimated.which are used to determine the denitrification potential of wastewater,to calculate the denitrification potential of the plant and to predict the nitrate effluent quality,as well as provide information for developing carbon dosage conlxol strategy.

  16. The role of external forcing in prolonged trends in Australian rainfall

    Frederiksen, Carsten S.; Grainger, Simon

    2015-11-01

    Based on model output from a multi-model ensemble (MME) of coupled atmosphere-ocean general circulation models, it is shown that prolonged trends in Australian rainfall over the southwest during winter and the monsoonal northwest during summer are associated with trends in the large scale Southern Hemisphere circulation. These trends, in turn, are the result of external radiative forcing, including anthropogenic greenhouse gases, ozone, aerosols and land use change. The MME is used in an analysis of covariance method to separate the internal (natural) variability in the coupled rainfall-atmospheric circulation relationship from influences associated with anomalous external radiative forcing. In both seasons, the leading coupled external mode (singular vector) in the twentieth century runs has rainfall and circulation loading patterns with associated time-series that have statistically significant trends. The associated rainfall loading patterns qualitatively resemble the patterns of observed rainfall trends. The circulation loading patterns reflect the thermal expansion of the tropics and the Hadley Cell. A comparison between similar analyses using the second half of the twenty-first century of the representative concentration pathways (RCP) RCP8.5 and RCP4.5 scenarios show that trends in rainfall and the circulation are projected to continue and intensify under increasing anthropogenic greenhouse gas concentrations. The technique developed here is generally applicable to separate the climate change signal from natural variability in any relevant pair of coupled climate fields.

  17. Vortical flows in strongly coupled Yukawa liquids under external forcing - A molecular dynamics approach

    Ganesh, Rajaraman; Charan, Harish

    2016-07-01

    Understanding vortical flows under external forcing in two dimensional (2D) fluids is a fundamental paradigm for structure formation in driven, dissipative systems. Considering Yukawa liquid as a prototype for strongly correlated or strongly coupled plasmas characterized by coupling strength (Γ, the ratio of average potential to kinetic energy per particle) and screening parameter (κ, ratio of mean inter-particle distance to shielding length), we address two important problems: 1. Onset of Rayleigh Benard convection cell (RBCC) in 2D Yukawa liquids subject to gravity and external temperature gradient 2. Onset of von Karman vortices in 2D Yukawa liquid under external pressure head, using large scale, first principles molecular dynamics simulations. For typical values of (Γ,κ), existence of a critical external temperature difference is demonstrated, beyond which RBCC are seen to set in. Beyond this critical external temperature difference, the strength of the maximum convective flow velocity is shown to exhibit a new, hitherto unsuspected linear relationship with external temperature difference and with a slope independent of (Γ,κ). The time taken for the transients to settle down to a steady state RBCC τ_s, is found to be maximum close to the above said critical external temperature difference and is seen to reduce with increasing external temperature difference. For the range of values of (Γ, κ) considered here, τ_s ≃ 10 000-20 000;ω^{-1}_{pd}, where ω_{pd} is dust plasma frequency. As Γ is increased to very high values, due to strong coupling effects, RBC cells are seen to be in a transient state without attaining a steady state for as long as 100 000;ω^{-1}_{pd}, even for a very high external temperature difference. In the second part, we address the existence of universal relation between Strouhal (St) and Rayleigh (Ry) numbers for Yukawa liquid using first principles based classical molecular dynamics. The flow past an obstacle is seen to indeed

  18. Biopolymers under large external forces and mean-field RNA virus evolutionary dynamics

    Ahsan, Syed Amir

    The modeling of the mechanical response of single-molecules of DNA and RNA under large external forces through statistical mechanical methods is central to this thesis with a small portion devoted to modeling the evolutionary dynamics of positive-sense single-stranded RNA viruses. In order to develop and test models of biopolymer mechanics and illuminate the mechanisms underlying biological processes where biopolymers undergo changes in energy on the order of the thermal energy, , entails measuring forces and lengths on the scale of piconewtons (pN) and nanometers (nm), respectively. A capacity achieved in the past two decades at the single-molecule level through the development of micromanipulation techniques such as magnetic and optical tweezers, atomic force microscopy, coupled with advances in micro- and nanofabrication. The statistical mechanical models of biopolymers developed in this dissertation are dependent upon and the outcome of these advancements and resulting experiments. The dissertation begins in chapter 1 with an introduction to the structure and thermodynamics of DNA and RNA, highlighting the importance and effectiveness of simple, two-state models in their description as a prelude to the emergence of two-state models in the research manuscripts. In chapter 2 the standard models of the elasticity of polymers and of a polymer gel are reviewed, characterizing the continuum and mean-field models, including the scaling behavior of DNA in confined spaces. The research manuscript presented in the last section of chapter 2 (section 2.5), subsequent to a review of a Flory gel and in contrast to it, is a model of the elasticity of RNA as a gel, with viral RNA illustrating an instance of such a network, and shown to exhibit anomalous elastic behavior, a negative Poisson ratio, and capable of facilitating viral RNA encapsidation with further context provided in section 5.1. In chapter 3 the experimental methods and behavior of DNA and RNA under mechanical

  19. Evaluation of structural reliability for vacuum vessel under external pressure and electromagnetic force

    Static and dynamic structural analyses of the vacuum vessel for a Swimming Pool Type Tokamak Reactor (SPTR) have been conducted under the external pressure (hydraulic and atmospheric pressure) during normal operation or the electromagnetic force due to plasma disruption. The reactor structural design is based on the concept that the adjacent modules of the vacuum vessel are not connected mechanically with bolts in the torus inboard region each other, so as to save the required space for inserting the remote handling machine for tightenning and untightenning bolts in the region and to simplify the repair and maintenance of the reactor. The structural analyses of the vacuum vessel have been carried out under the external pressure and the electromagnetic force and the structural reliability against the static and dynamic loads is estimated. The several configurations of the lip seal between the modules, which is required to make a plasma vacuum boundary, have been proposed and the structural strength under the forced displacements due to the deformation of the vacuum vessel is also estimated. (author)

  20. RNA polymerase motor on DNA track: effects of interactions, external force and torque

    Tripathi, Tripti

    2008-01-01

    RNA polymerase (RNAP) is like a mobile molecular workshop that polymerizes a RNA molecule by adding monomeric subunits one by one, while moving step by step on the DNA template itself. Here we develop a theoretical model by incorporating their steric interactions and mechanochemical cycles which explicitly captures the cyclical shape changes of each motor. Using this model, we explain not only the dependence of the average velocity of a RNAP on the externally applied load force, but also predict a {\\it nonmotonic} variation of the average velocity on external torque. We also show the effect of steric interactions of the motors on the total rate of RNA synthesis. In principle, our predictions can be tested by carrying out {\\it in-vitro} experiments.

  1. Collisionless Boltzmann equation with an external periodic traveling force: Analytical solution and application to molecular optics

    We present an analytical solution to the collisionless Boltzmann equation for describing the distribution function of molecular ensembles subject to an external periodic traveling force of pulsed optical fields. We apply our solution to study a pulsed standing wave mirror for neutral molecules, recently proposed [P. Ryytty et al., Phys. Rev. Lett. 84, 5074 (2000)]. Using our analytical solution we study the effects of the anharmonicity of optical potential on the reflectivity of the molecular mirror and the corresponding optimal pulse duration. We demonstrate that the reflectivity of the molecular mirror can be significantly improved by optimizing the pulse duration of the external optical fields when taking into account the anharmonicity of molecular motion

  2. Integrated reservoir characterization: Improvement in heterogeneities stochastic modelling by integration of additional external constraints

    Doligez, B.; Eschard, R. [Institut Francais du Petrole, Rueil Malmaison (France); Geffroy, F. [Centre de Geostatistique, Fontainebleau (France)] [and others

    1997-08-01

    The classical approach to construct reservoir models is to start with a fine scale geological model which is informed with petrophysical properties. Then scaling-up techniques allow to obtain a reservoir model which is compatible with the fluid flow simulators. Geostatistical modelling techniques are widely used to build the geological models before scaling-up. These methods provide equiprobable images of the area under investigation, which honor the well data, and which variability is the same than the variability computed from the data. At an appraisal phase, when few data are available, or when the wells are insufficient to describe all the heterogeneities and the behavior of the field, additional constraints are needed to obtain a more realistic geological model. For example, seismic data or stratigraphic models can provide average reservoir information with an excellent areal coverage, but with a poor vertical resolution. New advances in modelisation techniques allow now to integrate this type of additional external information in order to constrain the simulations. In particular, 2D or 3D seismic derived information grids, or sand-shale ratios maps coming from stratigraphic models can be used as external drifts to compute the geological image of the reservoir at the fine scale. Examples are presented to illustrate the use of these new tools, their impact on the final reservoir model, and their sensitivity to some key parameters.

  3. Fuzzy Control of Nitrate Recirculation and External Carbon Addition in A/O Nitrogen Removal Process

    马勇; 彭永臻; 王淑莹; 王晓莲

    2005-01-01

    Nitrogen and phosphorous concentrations of effluent water must be taken into account for the design and operation of wastewater treatment plants. In addition, the requirement for effluent quality is becoming strict.Therefore, intelligent control approaches are recently required in removing biological nutrient. In this study, fuzzy control has been successfully applied to improve the nitrogen removal. Experimental results showed that a close relationship between nitrate concentration and oxidation-reduction potential (ORP) at the end of anoxic zone was found for anoxic/oxic (A/O) nitrogen removal process treating synthetic wastewater. ORP can be used as online fuzzy control parazneter of nitrate recirculation and external carbon addition. The established fuzzy logic controller that includes two inputs and one output can maintain ORP value at-86 mV and -90 mV by adjusting the nitrate recirculation flow and external carbon dosage respectively to realize the optimal control of nitrogen removal, improving the effluent quality and reducing the operating cost.

  4. Stochastic Resonance in an Asymmetric Mono-stable System Subject to Two Periodic Forces and Multiplicative and Additive Noise

    LUO Xiang-Dong; GUO Feng; ZHOU Yu-Rong

    2009-01-01

    The phenomenon of stochastic resonance (SR) in an asymmetric mono-stable system subject to two external periodic forces and multiplicative and additive noise is investigated.It is shown that the signal-to-noise ratio (SNR) for the fundamental and higher harmonics is a non-monotonic function of the intensities of the multiplicative and additive noise, as well as of the system parameter.Moreover, the SNR for the fundamental harmonic decreases with the increase of the system asymmetry, while the SNR for the higher harmonics behaves non-monotonically as the system asymmetry varies.

  5. Stochastic Resonance in an Asymmetric Mono-stable System Subject to Two Periodic Forces and Multiplicative and Additive Noise

    The phenomenon of stochastic resonance (SR) in an asymmetric mono-stable system subject to two external periodic forces and multiplicative and additive noise is investigated. It is shown that the signal-to-noise ratio (SNR) for the fundamental and higher harmonics is a non-monotonic function of the intensities of the multiplicative and additive noise, as well as of the system parameter. Moreover, the SNR for the fundamental harmonic decreases with the increase of the system asymmetry, while the SNR for the higher harmonics behaves non-monotonically as the system asymmetry varies.

  6. A Stability Criterion for Time-Delay Tension Leg Platform Systems Subjected to External Force

    Chen-Yuan CHEN; Chien-wen SHEN; Cheng-Wu CHEN; Kevin Fong-Rey LIU; Ming-Jen CHENG

    2009-01-01

    Stability analysis plays a central role in nonlinear system theory and engineering application.Over the past few yeats,the stability analysis of fuzzy systems has been proposed and there are many successful applications in practical engineering.Therefore,in this paper firstly proposed is the stability analysis on oceanic structure by fuzzy models.In the present study,Takagi-Sugeno (T-S) fuzzy model is proposed for a time delay tension leg platform (TLP) system subjected to an external wave force.In terms of stability analysis,linear matrix inequality (LMI) conditions are derived via Lyapunov theory to guarantee the stability of the TLP system.

  7. A simple method to construct soliton-like solution of the general KdV equation with external force

    JiefangZHANG; FengminWU

    2000-01-01

    A simple and direct method is described to construct the soliton-like solution for the general KdV equation with external force. Crucial to the method is the assumption that the solution chosen is a special truncated expansion.

  8. Analysis of Externality of Rural Labor Force Flow in Central and Western Regions of China and Benefit Compensation

    LI, XIN; Hu, Haijing

    2013-01-01

    According to the theories of institutional economics and development economics, the positive and negative externality of rural labor force flowing from central and western regions and into eastern regions of China were analyzed, and then it was proposed that it is necessary to positive externality, rather than take “household register†measures to solve the problem simply.

  9. Analysis of Externality of Rural Labor Force Flow in Central and Western Regions of China and Benefit Compensation

    Xin; LI; Haijing; HU

    2013-01-01

    According to the theories of institutional economics and development economics,the positive and negative externality of rural labor force flowing from central and western regions and into eastern regions of China were analyzed,and then it was proposed that it is necessary to positive externality,rather than take"household register"measures to solve the problem simply.

  10. Non-invasive determination of external forces in vortex-pair-cylinder interactions

    Hartmann, D.; Schröder, W.; Shashikanth, B. N.

    2012-06-01

    Expressions for the conserved linear and angular momenta of a dynamically coupled fluid + solid system are derived. Based on the knowledge of the flow velocity field, these expressions allow the determination of the external forces exerted on a body moving in the fluid such as, e.g., swimming fish. The verification of the derived conserved quantities is done numerically. The interaction of a vortex pair with a circular cylinder in various configurations of motions representing a generic test case for a dynamically coupled fluid + solid system is investigated in a weakly compressible Navier-Stokes setting using a Cartesian cut-cell method, i.e., the moving circular cylinder is represented by cut cells on a moving mesh. The objectives of this study are twofold. The first objective is to show the robustness of the derived expressions for the conserved linear and angular momenta with respect to bounded and discrete data sets. The second objective is to study the coupled dynamics of the vortex pair and a neutrally buoyant cylinder free to move in response to the fluid stresses exerted on its surface. A comparison of the vortex-body interaction with the case of a fixed circular cylinder evidences significant differences in the vortex dynamics. When the cylinder is fixed strong secondary vorticity is generated resulting in a repeating process between the primary vortex pair and the cylinder. In the neutrally buoyant cylinder case, a stable structure consisting of the primary vortex pair and secondary vorticity shear layers stays attached to the moving cylinder. In addition to these fundamental cases, the vortex-pair-cylinder interaction is studied for locomotion at constant speed and locomotion at constant thrust. It is shown that a similar vortex structure like in the neutrally buoyant cylinder case is obtained when the cylinder moves away from the approaching vortex pair at a constant speed smaller than the vortex pair translational velocity. Finally, the idealized

  11. The influence of external forcing on subdecadal variability of regional surface temperature in CMIP5 simulations of the last millennium

    Le, Thanh; Sjolte, Jesper; Muscheler, Raimund

    2016-02-01

    We use Granger causality to investigate the influences of external forcings on subdecadal variability of regional near-surface air temperature (SAT) in past millennium simulations (period 850-1850 A.D.) of the Coupled Model Intercomparison Project Phase 5 (CMIP5) models. Our results strengthen the conclusion for robust influence of volcanic forcing on SAT during preindustrial times of the last millennium. The SAT response to solar variations is detected in tropical and subtropical regions. In other regions, this response is weak. The impact of greenhouse gases (GHGs) radiative forcing to regional SAT is weak and uncertain. This is most probably due to the low amplitude of the variations in GHGs and hence weak GHGs forcing during the preindustrial millennium. The low agreement between models in simulating the impacts of solar variations on SAT in several regions suggests the different dynamical responses in these models, possibly associated with inaccurate parameterization of the processes related to solar forcing. Our analysis suggests that internal climate variability played a more significant role than external forcings in short-term SAT variability in the regions of the North Atlantic, the North Pacific, the Arctic, the Antarctic Peninsula, and its surrounding oceans. The possibility of long-term impacts of external forcings on SAT and the uncertainties that might be contained due to effects of internal climate modes other than El Niño-Southern Oscillation underscore the necessity for a more detailed understanding of the dynamical response of SAT to external forcings.

  12. Iterative weighted average diffusion as a novel external force in the active contour model

    Mirov, Ilya S.; Nakhmani, Arie

    2016-03-01

    The active contour model has good performance in boundary extraction for medical images; particularly, Gradient Vector Flow (GVF) active contour model shows good performance at concavity convergence and insensitivity to initialization, yet it is susceptible to edge leaking, deep and narrow concavities, and has some issues handling noisy images. This paper proposes a novel external force, called Iterative Weighted Average Diffusion (IWAD), which used in tandem with parametric active contours, provides superior performance in images with high values of concavity. The image gradient is first turned into an edge image, smoothed, and modified with enhanced corner detection, then the IWAD algorithm diffuses the force at a given pixel based on its 3x3 pixel neighborhood. A forgetting factor, φ, is employed to ensure that forces being spread away from the boundary of the image will attenuate. The experimental results show better behavior in high curvature regions, faster convergence, and less edge leaking than GVF when both are compared to expert manual segmentation of the images.

  13. Evidence for external forcing of the Atlantic Multidecadal Oscillation since the termination of the Little Ice Age

    Faurschou Knudsen, Mads; Holm Jacobsen, Bo; Seidenkrantz, Marit-Solveig; Olsen, Jesper

    2014-05-01

    Variations in North Atlantic sea-surface temperatures (SSTs) are particularly prominent on multidecadal timescales. These changes, which exert a strong influence on climate in the North Atlantic region, are dominated by the alternation between warm and cold SST anomalies on a timescale of 60-80 years, a phenomenon known as the Atlantic Multidecadal Oscillation (AMO). The forcing mechanism pacing the AMO remains subject to considerable debate. One school of thought holds that the AMO is driven by internal ocean variability and related to multidecadal fluctuations in the Atlantic meridional overturning circulation (AMOC). In contrast, a recent model study concluded that the combined external forcing due to solar variability and volcanic eruptions has dictated the pace and phasing of the AMO over the past 600 years, as the combined solar and volcanic forcing is highly correlated to the AMO in the model with the forcing leading this AMO by ~5 years. Identifying the relative roles of internal ocean variability and external forcing agents in driving multi-decadal SST variability in the North Atlantic is important, in particular because the AMO purportedly influence climate variables of key importance to society, such as precipitation and hurricane activity. In the present study, we examine the relationship between the AMO and potential external forcing agents over the past 450 years based on statistical analyses of available high-resolution proxy data. The evidence suggests that external forcing played a dominant role in pacing the AMO after termination of the Little Ice Age (LIA; ca. 1400-1800), with an instantaneous impact on mid-latitude sea-surface temperatures that spread across the North Atlantic over the ensuing ~5 years. In contrast, the role of external forcing was more ambiguous during the LIA. Our study further suggests that the Atlantic Meridional Overturning Circulation (AMOC) is important for linking external forcing with North Atlantic sea

  14. Research on additional external exposure dose rate measurement by in-situ HPGe γ spectrometer

    A spectrometric method for additional exposure dose rate (external dose rate due to γ-ray emitted by artificial nuclides) measurement is introduced. The principle of this method is that: strip off the spectrum attributed to the natural radionuclides from the gamma spectrum collected by in situ HPGe spectrometer, and get the spectrum attributed to the artificial radionuclides, then integrate the stripped spectrum with corresponding spectrum-dose conversion function (G(E) function) values to acquire additional exposure dose rate. Standard spectrums attributed to nuclides in U series, Th series and 40K were calibrated by in situ HPGe spectrometer at airborne pads, and the interference caused by other nuclides was eliminated by the inverse matrix calculations. The natural compositions in the spectrum is stripped according to the standard spectrums. Six standard γ-ray sources were used to acquire the response functions of the HPGe spectrometer, then the G(E) function was calculated by the least square method. Finally, the utility of this method was verified by in situ experiment, and the factors that influence the precision of the results are discussed. (author)

  15. Morphodynamic equilibrium in straight tidal channels: Combined effects of the Coriolis force and external overtides

    Schramkowski, G. P.; de Swart, H. E.

    2002-12-01

    A new physical mechanism that is potentially relevant for the equilibrium morphodynamics of tide-dominated estuaries and in understanding the occurrence of lateral shoals in these systems is identified. The mechanism acts in relatively straight and wide channels (width of the order of the horizontal tidal excursion length) in which both external overtides and the Coriolis force affect sediment transport. This is investigated by analyzing an idealized model, which consists of the 3D shallow water equations, mass conservation for suspended load, and a bed evolution equation. The model is forced by a prescribed depth-averaged tidal current. It is demonstrated that, when viewed in the direction of the flood flow, a flood (ebb)-dominant current generates a net cross-sectional sediment transport to the left (right) in the Northern Hemisphere. A morphodynamic equilibrium is established by a counteracting dispersive sediment flux, generated by shear stresses that increase toward shallower water. This dispersive flux is much larger than the flux due gravitational downslope effects. The equilibrium bed profile has a constant slope in the lateral direction that varies as cos(φ), where φ is the phase difference between the M2 and M4 external horizontal tide. Hence, the smallest depths are found on the left (right) in case of a flood (ebb)-dominant current. Typical cross-channel depth differences may be as large as several meters. Velocity data collected in the Dutch Western Scheldt estuary are used to tune the hydrodynamic parameters in the model. Analysis of the bathymetric data seems to confirm the qualitative results of the model.

  16. The effect of an external magnetic force on cell adhesion and proliferation of magnetically labeled mesenchymal stem cells

    Nakamae Toshio

    2010-02-01

    Full Text Available Abstract Background As the strategy for tissue regeneration using mesenchymal stem cells (MSCs for transplantation, it is necessary that MSCs be accumulated and kept in the target area. To accumulate MSCs effectively, we developed a novel technique for a magnetic targeting system with magnetically labeled MSCs and an external magnetic force. In this study, we examined the effect of an external magnetic force on magnetically labeled MSCs in terms of cell adhesion and proliferation. Methods Magnetically labeled MSCs were plated at the bottom of an insert under the influence of an external magnetic force for 1 hour. Then the inserts were turned upside down for between 1 and 24 hours, and the number of MSCs which had fallen from the membrane was counted. The gene expression of MSCs affected magnetic force was analyzed with microarray. In the control group, the same procedure was done without the external magnetic force. Results At 1 hour after the inserts were turned upside down, the average number of fallen MSCs in the magnetic group was significantly smaller than that in the control group, indicating enhanced cell adhesion. At 24 hours, the average number of fallen MSCs in the magnetic group was also significantly smaller than that in control group. In the magnetic group, integrin alpha2, alpha6, beta3 BP, intercellular adhesion molecule-2 (ICAM-2, platelet/endothelial cell adhesion molecule-1 (PECAM-1 were upregulated. At 1, 2 and 3 weeks after incubation, there was no statistical significant difference in the numbers of MSCs in the magnetic group and control group. Conclusions The results indicate that an external magnetic force for 1 hour enhances cell adhesion of MSCs. Moreover, there is no difference in cell proliferation after using an external magnetic force on magnetically labeled MSCs.

  17. Entropic transport without external force in confined channel with oscillatory boundary.

    Ding, Huai; Jiang, Huijun; Hou, Zhonghuai

    2015-12-28

    The dynamics of point-like Brownian particles in a periodic confined channel with oscillating boundaries has been studied. Directional transport (DT) behavior, characterized by net displacement along the horizontal direction, is observed even without external force which is necessary for the conventional DT where the boundaries are static. For typical parameter values, the average velocity Vt of DT reaches a maximum with the variation of the noise intensity D, being alike to the phenomenon of stochastic resonance. Interestingly, we find that Vt shows nontrivial dependences on the particle gravity G depending on the noise level. When the noise is large, Vt increases monotonically with G indicating that heavier particle moves faster, while for small noise, Vt shows a bell-shape dependence on G, suggesting that a particle with an intermediate weight may move the fastest. Such results were not observed for DT in a channel with static boundaries. To understand these findings, we have adopted an effective one-dimensional coarsening description, which facilitates us to introduce an effective entropic force along the horizontal direction. The average force is apparently nonzero due to the oscillatory boundary, hence leading to the net transport, and it shows similar dependences as Vt on the noise intensity D and particle gravity G. The dependences of the DT behavior on other parameters describing the oscillatory channel have also been investigated, showing that DT is more pronounced for larger oscillation amplitude and frequency, and asymmetric geometry within a channel period and phase difference between neighboring periods are both necessary for the occurrence of DT. PMID:26723663

  18. Entropic transport without external force in confined channel with oscillatory boundary

    Ding, Huai; Jiang, Huijun; Hou, Zhonghuai, E-mail: hzhlj@ustc.edu.cn [Department of Chemical Physics & Hefei National Laboratory for Physical Sciences at Microscales, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2015-12-28

    The dynamics of point-like Brownian particles in a periodic confined channel with oscillating boundaries has been studied. Directional transport (DT) behavior, characterized by net displacement along the horizontal direction, is observed even without external force which is necessary for the conventional DT where the boundaries are static. For typical parameter values, the average velocity V{sub t} of DT reaches a maximum with the variation of the noise intensity D, being alike to the phenomenon of stochastic resonance. Interestingly, we find that V{sub t} shows nontrivial dependences on the particle gravity G depending on the noise level. When the noise is large, V{sub t} increases monotonically with G indicating that heavier particle moves faster, while for small noise, V{sub t} shows a bell-shape dependence on G, suggesting that a particle with an intermediate weight may move the fastest. Such results were not observed for DT in a channel with static boundaries. To understand these findings, we have adopted an effective one-dimensional coarsening description, which facilitates us to introduce an effective entropic force along the horizontal direction. The average force is apparently nonzero due to the oscillatory boundary, hence leading to the net transport, and it shows similar dependences as V{sub t} on the noise intensity D and particle gravity G. The dependences of the DT behavior on other parameters describing the oscillatory channel have also been investigated, showing that DT is more pronounced for larger oscillation amplitude and frequency, and asymmetric geometry within a channel period and phase difference between neighboring periods are both necessary for the occurrence of DT.

  19. Systematic attribution of observed Southern Hemisphere circulation trends to external forcing and internal variability

    Franzke, C. L. E.; O'Kane, T. J.; Monselesan, D. P.; Risbey, J. S.; Horenko, I.

    2015-09-01

    A critical question in the global warming debate concerns the causes of the observed trends of the Southern Hemisphere (SH) atmospheric circulation over recent decades. Secular trends have been identified in the frequency of occurrence of circulation regimes, namely the positive phase of the Southern Annular Mode (SAM) and the hemispheric wave-3 pattern which is associated with blocking. Previous studies into the causes of these secular trends have either been purely model based, have not included observational forcing data or have mixed external forcing with indices of internal climate variability impeding a systematic and unbiased attribution of the causes of the secular trends. Most model studies also focused mainly on the austral summer season. However, the changes to the storm tracks have occurred in all seasons and particularly in the austral winter and early spring when midlatitude blocking is most active and stratospheric ozone should not play a role. Here we systematically attribute the secular trends over the recent decades using a non-stationary clustering method applied to both reanalysis and observational forcing data from all seasons. While most previous studies emphasized the importance of stratospheric ozone depletion in causing austral summer SH circulation trends, we show observational evidence that anthropogenic greenhouse gas concentrations have been the major driver of these secular trends in the SAM and blocking when all seasons are considered. Our results suggest that the recovery of the ozone hole might delay the signal of global warming less strongly than previously thought and that effects from all seasons are likely crucial in understanding the causes of the secular trends.

  20. Systematic attribution of observed southern hemispheric circulation trends to external forcing and internal variability

    Franzke, C. L. E.; O'Kane, T. J.; Monselesan, D. P.; Risbey, J. S.; Horenko, I.

    2015-04-01

    A critical question in the global warming debate concerns the causes of the observed trends of the Southern Hemisphere (SH) atmospheric circulation over recent decades. Secular trends have been identified in the frequency of occurrence of circulation regimes, namely the positive phase of the Southern Annular Mode (SAM) and the hemispheric wave 3 pattern which is associated with blocking. Previous studies into the causes of these secular trends have either been purely model based, have not included observational forcing data or have mixed external forcing with indices of internal climate variability impeding a systematic and unbiased attribution of the causes of the secular trends. Most model studies also focused mainly on the austral summer season. However, the changes to the storm tracks have occurred in all seasons and particularly in the austral winter and early spring when mid-latitude blocking is most active and stratospheric ozone should not a play a role. Here we systematically attribute the secular trends over the recent decades using a non-stationary clustering method applied to both reanalysis and observational forcing data from all seasons. While most previous studies emphasized the importance of stratospheric ozone depletion in causing austral summer SH circulation trends, we show observational evidence that anthropogenic greenhouse gas concentrations have been the major driver of these secular trends in the SAM and blocking when all seasons are considered. Our results suggest that the recovery of the ozone hole might delay the signal of global warming less strongly than previously thought and that effects from all seasons are likely crucial in understanding the causes of the secular trends.

  1. External forcing as a source for the observed multi-decadal relation between AMV and the Indian summer monsoon

    Svendsen, Lea; Luo, Feifei; Sankar, Syam; Gao, Yongqi; Keenlyside, Noel; Vareed Joseph, Porathur; Johannessen, Ola

    2016-04-01

    The instrumental records show a significant positive correlation between the Atlantic multi-decadal variability (AMV) and the Indian summer monsoon (ISM) rainfall, where a positive (negative) AMV is associated with more (less) ISM rainfall. We have used both proxy reconstruction and twelve models from the Coupled Model Intercomparison Project Phase 5 (CMIP5) to investigate if the observed AMV-ISM relation is a persistent internal climate signal or externally forced. A comparison of several annual resolution proxy records both from the Atlantic and for the ISM show that the multi-decadal variability in both indices is persistent, but the link between them is not. The correlation between the two regions is weak, and even negative in some periods, before the instrumental time period. The analysis of CMIP5 simualtions is consistent with these results. While none of the CMIP5 models investigated simulate the significant AMV-ISM connection in the pre-industrial control simulations with fixed external forcing, three of the models reproduce the relation in the 20th century historical simulations with transient forcing. In these models external forcing is linked to the mid-to-upper tropospheric temperature pattern with a strengthened land-ocean contrast over South Asia, consistent with an enhanced ISM, as well as the evolution of AMV. We conclude that the significant AMV-ISM relation found in the observations after the industrial revolution may be associated with external forcing, rather than being internal climate variability.

  2. A statistical modelling study of the abrupt millennial-scale climate changes focusing on the influence of external forcings

    Mitsui, Takahito

    2015-01-01

    Dansgaard-Oeschger (DO) events are abrupt millennial-scale climate changes mainly detected in the North Atlantic region during the last glacial cycle. The frequency of the DO events varied in time, supposedly because of changes in background climate conditions. Here, we investigate the influences of external forcings on DO events with statistical modelling. We assume two types of generic stochastic dynamical systems models (double-well potential-type and oscillator-type), forced by the northern hemisphere summer insolation change and/or the global ice volume change. The models are calibrated by maximizing their likelihood and compared using the Bayesian Information Criterion (BIC). Among the models, the stochastic oscillator model forced by both insolation and ice volume changes is favored by the NGRIP calcium ion data. The BIC scores provide positive evidence for the ice volume forcing in the presence of the insolation forcing but weak evidence for the insolation forcing in the presence of the ice volume for...

  3. Non-equilibrium processes in non-homogeneous fluids under the action of external forces

    This paper is devoted to the investigation of stable stratification effects that arise as a result of the combined influence of the external forces and environmental media's non-homogeneity due to the non-uniform distribution of dissolved or suspended matter, temperature, gas bubbles and so on. Such a medium is a thermodynamically non-equilibrium system where non-uniformity of the density flux causes the formation of specific fluid motions that are diffusion-induced flows and internal waves (IW), which are non-existent in a homogeneous fluid. In this paper, we demonstrate numerical calculations on flows’ fine structure around impermeable motionless plates with finite length and uniformly moving sloping plates in the interior of a continuously stratified fluid. The flow patterns are investigated both in the direct vicinity of the plate where compact non-wave boundary layer-like components and jet flows are observed and at long distances from the obstacle where sharp horizontal interfaces and groups of IW are revealed. The flows’ properties are analyzed as a function of the dimensional parameters of the problem, i.e. the value of stratification, the plate's length and its slope angle to the horizon. The calculated flow patterns are compared with the earlier obtained asymptotic approximation of small and large times and high-resolution schlieren images of stratified flows around both motionless and moving sloping plates in the laboratory. (paper)

  4. Comparative evaluation of tableting compression behaviors by methods of internal and external lubricant addition: Inhibition of enzymatic activity of trypsin preparation by using external lubricant addition during the tableting compression process

    Otsuka, Makoto; Sato, Mitsuyo; Matsuda, Yoshihisa

    2001-01-01

    This study evaluated tableting compression by using internal and external lubricant addition. The effect of lubricant addition on the enzymatic activity of trypsin, which was used as a model drug during the tableting compression process, was also investigated. The powder mixture (2% crystalline trypsin, 58% crystalline lactose, and 40% microcrystalline cellulose) was kneaded with 5% hydroxypropyl cellulose aqueous solution and then granulated using an extruding granulator equipped with a 0.5-...

  5. Additional interfacial force in lattice Boltzmann models for incompressible multiphase flows

    Li, Q; Gao, Y J

    2011-01-01

    The existing lattice Boltzmann models for incompressible multiphase flows are mostly constructed with two distribution functions, one is the order parameter distribution function, which is used to track the interface between different phases, and the other is the pressure distribution function for solving the velocity field. In this brief report, it is shown that in these models the recovered momentum equation is inconsistent with the target one: an additional interfacial force is included in the recovered momentum equation. The effects of the additional force are investigated by numerical simulations of droplet splashing on a thin liquid film and falling droplet under gravity. In the former test, it is found that the formation and evolution of secondary droplets are greatly affected, while in the latter the additional force is found to increase the falling velocity and limit the stretch of the droplet.

  6. Dissipative Nonlinear Schrödinger Equation with External Forcing in Rotational Stratified Fluids and Its Solution

    Shi, Yun-Long; Yang, Hong-Wei; Yin, Bao-Shu; Yang, De-Zhou; Xu, Zhen-Hua; Feng, Xing-Ru

    2015-10-01

    The dissipative nonlinear Schrödinger equation with a forcing item is derived by using of multiple scales analysis and perturbation method as a mathematical model of describing envelope solitary Rossby waves with dissipation effect and external forcing in rotational stratified fluids. By analyzing the evolution of amplitude of envelope solitary Rossby waves, it is found that the shear of basic flow, Brunt-Vaisala frequency and β effect are important factors in forming the envelope solitary Rossby waves. By employing Jacobi elliptic function expansion method and Hirota's direct method, the analytic solutions of dissipative nonlinear Schrödinger equation and forced nonlinear Schrödinger equation are derived, respectively. With the help of these solutions, the effects of dissipation and external forcing on the evolution of envelope solitary Rossby wave are also discussed in detail. The results show that dissipation causes slowly decrease of amplitude of envelope solitary Rossby waves and slowly increase of width, while it has no effect on the propagation speed and different types of external forcing can excite the same envelope solitary Rossby waves. It is notable that dissipation and different types of external forcing have certain influence on the carrier frequency of envelope solitary Rossby waves. Supported by Foundation for Innovative Research Groups of the National Natural Science Foundation of China under Grant No. 41421005, National Natural Science Foundation of China under Grant Nos. 41376030, 41376029, 41476019, NSFC-Shandong Joint Fund for Marine Science Research Centers Grant (U1406401), Special Funds for Theoretical Physics of the National Natural Science Foundation of China under Grant No. 11447205

  7. Influence of external climate forcing on coastal upwelling systems analysed in ensemble of past millennium climate simulations

    Tim, Nele; Zorita, Eduardo; Hünicke, Birgit; Yi, Xin; Emeis, Kay

    2016-04-01

    Eastern Boundary Upwelling Systems are highly productive coastal ocean areas where nutrient rich, cold water upwells by the action of favorable winds. Observations over the 20th century and ocean sediment records, which may be indicative of upwelling, display an intensification due to stronger external climate forcing, such as increasing greenhouse gas concentrations or changes in solar irradiance. This intensification is compatible with the hypothesis put forward by Bakun (1990) that a stronger external radiative forcing should lead to a more intense coastal upwelling. Here, we analyze ensemble of simulations covering the past millennium with the aim of identifying and quantifying the role of external climate forcing on upwelling in the major Eastern Boundary Upwelling System. We analyse the decadal variability and centennial trends of upwelling in ensemble of simulations with the global climate model MPI-ESM covering the past millennium, the last 150 years and the next 100 years. The future simulations were driven by three IPCC scenarios of concentrations of anthropogenic greenhouse gases, RCP2.5, RCP4.5 and RCP 8.5. For the past millennium and the last 150 years, coastal upwelling does not show any imprint of external forcing. This result indicates that chaotic internal variability has dominated upwelling intensity in major upwelling regions over the last thousand years and even since industrialisation up to present. For the 21st century, all ensemble members show a consistent and significant intensification of upwelling in the strongest scenario RCP8.5 for the Benguela upwelling region, consistent and significant weakening for Morocco and California, and no significant change for the Peruvian upwelling. Weaker scenarios do not produce consistent long-term trends that are replicated in all ensemble members. The results are confirmed by analysing another ensemble of past millennium simulations with the model CESM-CAM5 (Community Earth System Model

  8. Update on the use of dissolved oxygen addition to monitor the effectiveness of noble metal applications in external manifolds

    Electrochemical corrosion potential (ECP) measurements in a Mitigation Monitoring System (MMS) ECP manifold have historically been a primary indicator of the effectiveness of an On-Line NobleChem™ (OLNC) application, with the MMS ECP intended to measure the catalytic effect of noble metal deposited on the ECP manifold surface. In some plants ECP measurements made on untreated surfaces prior to an OLNC application were significantly lower than what would be expected for stainless steel under reactor bulk chemistry conditions. This is due to the consumption and depletion of bulk liquid dissolved oxygen (DO) in the lines supplying reactor water to these external ECP measurement locations. This phenomenon degrades the ability to use these external manifolds to confirm noble metal deposition. Previous papers have described how the injection of an oxygen-rich stream to the MMS supply stream (DO Addition) can be used to re-establish the capability of external ECP measurements to monitor the catalytic behavior of platinum deposited during an OLNC injection. This paper will provide an update of how this method is being successfully used in operating BWRs to monitor OLNC injections. The paper will outline the overall approach used to characterize the catalytic behavior of external ECP manifolds before and after the noble metal application and present plant data collected during DO Additions performed under various conditions. (author)

  9. A novel approach for phosphorus recovery and no wasted sludge in enhanced biological phosphorus removal process with external COD addition.

    Xia, Cheng-Wang; Ma, Yun-Jie; Zhang, Fang; Lu, Yong-Ze; Zeng, Raymond J

    2014-01-01

    In enhanced biological phosphorus removal (EBPR) process, phosphorus (P) in wastewater is removed via wasted sludge without actual recovery. A novel approach to realize phosphorus recovery with special external chemical oxygen demand (COD) addition in EBPR process was proposed. During the new operating approach period, it was found that (1) no phosphorus was detected in the effluent; (2) with an external addition of 10 % of influent COD amount, 79 % phosphorus in the wastewater influent was recovered; (3) without wasted sludge, the MLVSS concentration in the system increased from 2,010 to 3,400 mg/L and kept stable after day 11 during 24-day operating period. This demonstrates that the novel approach is feasible to realize phosphorus recovery with no wasted sludge discharge in EBPR process. Furthermore, this approach decouples P removal and sludge age, which may enhance the application of membrane bioreactor for P removal. PMID:24122666

  10. Review of the formulation of present-generation stratospheric chemistry-climate models and associated external forcings

    O. Morgenstern; M. A. Giorgetta; Shibata, K; Eyring, V.; D. W. Waugh; T. G. Shepherd; H. Akiyoshi; Austin, J; Baumgaertner, A.J.G.; Bekki, S.; P. Braesicke; Brühl, C.; Chipperfield, M. P.; Cugnet, D.; M. Dameris

    2010-01-01

    The goal of the Chemistry-Climate Model Validation (CCMVal) activity is to improve understanding of chemistry-climate models (CCMs) through process-oriented evaluation and to provide reliable projections of stratospheric ozone and its impact on climate. An appreciation of the details of model formulations is essential for understanding how models respond to the changing external forcings of greenhouse gases and ozone-depleting substances, and hence for understanding the ozone and climate fore...

  11. Dynamics of a Michaelis–Menten-type predation model incorporating a prey refuge with noise and external forces

    In this paper, we investigate a spatial version of a Michaelis–Menten-type predator–prey model incorporating a prey refuge, which contains some important factors, such as environmental noise, external periodic forces and diffusion processes on both prey and predator. Based on both mathematical analysis and numerical simulations, we get a sufficient condition for diffusion instability with zero-flux boundary conditions. There is an increase in the equilibrium density of both prey and predator as the prey refuge increases under a very restricted set of conditions. It is also proved that the refuge used by prey has a stabilizing effect, that is, increases the local stability of the interior equilibrium. Moreover, due to the effects of environmental noise, we obtain the transition from regular patterns to spatiotemporal chaotic dynamics in a corresponding spatially extended model. External periodic forces can induce 1:1 frequency-locking and spatially homogeneous oscillation to appear. Also the interaction between environmental noise and external periodic forces in the spatial model incorporating a prey refuge gives rise to a rich dynamic phenomenon

  12. Materials Bound by Non-Chemical Forces: External Fields and the Quantum Vacuum

    Swain, John; Widom, Allan; Srivastava, Yogendra

    2014-01-01

    We discuss materials which owe their stability to external fields. These include: 1) external electric or magnetic fields, and 2) quantum vacuum fluctuations in these fields induced by suitable boundary conditions (the Casimir effect). Instances of the first case include the floating water bridge and ferrofluids in magnetic fields. An example of the second case is taken from biology where the Casimir effect provides an explanation of the formation of stacked aggregations or "rouleaux" by nega...

  13. Theoretical analysis of ferromagnetic microparticles in streaming liquid under the influence of external magnetic forces

    Brandl, Martin; Mayer, Michael; Hartmann, Jens; Posnicek, Thomas; Fabian, Christian; Falkenhagen, Dieter

    2010-09-01

    The microsphere based detoxification system (MDS) is designed for high specific toxin removal in extracorporeal blood purification using functionalized microparticles. A thin wall hollow fiber membrane filter separates the microparticle-plasma suspension from the bloodstream. For patient safety, it is necessary to have a safety system to detect membrane ruptures that could lead to the release of microparticles into the bloodstream. A non-invasive optical detection system including a magnetic trap is developed to monitor the extracorporeal venous bloodstream for the presence of released microparticles. For detection, fluorescence-labeled ferromagnetic beads are suspended together with adsorbent particles in the MDS circuit. In case of a membrane rupture, the labeled particles would be released into the venous bloodstream and partly captured by the magnetic trap of the detector. A physical model based on fluidic, gravitational and magnetic forces was developed to simulate the motion and sedimentation of ferromagnetic particles in a magnetic trap. In detailed simulation runs, the concentrations of accumulated particles under different applied magnetic fields within the magnetic trap are shown. The simulation results are qualitatively compared with laboratory experiments and show excellent accordance. Additionally, the sensitivity of the particle detection system is proofed in a MDS laboratory experiment by simulation of a membrane rupture.

  14. Interface dynamics of a two-component Bose-Einstein condensate driven by an external force

    Kobyakov, Dmitry; Bychkov, Vitaly; Lundh, Emil; Bezett, Alice; Akkerman, Vyacheslav; Marklund, Mattias

    2011-01-01

    The dynamics of an interface in a two-component Bose-Einstein condensate driven by a spatially uniform time-dependent force is studied. Starting from the Gross-Pitaevskii Lagrangian, the dispersion relation for linear waves and instabilities at the interface is derived by means of a variational approach. A number of diverse dynamical effects for different types of the driving force is demonstrated, which includes the Rayleigh-Taylor instability for a constant force, the Richtmyer-Meshkov inst...

  15. Modeling the Effect of External Carbon Source Addition under Different Electron Acceptor Conditions in Biological Nutrient Removal Activated Sludge Systems.

    Hu, Xiang; Wisniewski, Kamil; Czerwionka, Krzysztof; Zhou, Qi; Xie, Li; Makinia, Jacek

    2016-02-16

    The aim of this study was to expand the International Water Association Activated Sludge Model No. 2d (ASM2d) to predict the aerobic/anoxic behavior of polyphosphate accumulating organisms (PAOs) and "ordinary" heterotrophs in the presence of different external carbon sources and electron acceptors. The following new aspects were considered: (1) a new type of the readily biodegradable substrate, not available for the anaerobic activity of PAOs, (2) nitrite as an electron acceptor, and (3) acclimation of "ordinary" heterotrophs to the new external substrate via enzyme synthesis. The expanded model incorporated 30 new or modified process rate equations. The model was evaluated against data from several, especially designed laboratory experiments which focused on the combined effects of different types of external carbon sources (acetate, ethanol and fusel oil) and electron acceptors (dissolved oxygen, nitrate and nitrite) on the behavior of PAOs and "ordinary" heterotrophs. With the proposed expansions, it was possible to improve some deficiencies of the ASM2d in predicting the behavior of biological nutrient removal (BNR) systems with the addition of external carbon sources, including the effect of acclimation to the new carbon source. PMID:26783836

  16. External Carbon Source Addition as a Means to Control an Activated Sludge Nutrient Removal Process

    Isaacs, Steven Howard; Henze, Mogens; Søeberg, Henrik; Kymmel, Mogens

    1994-01-01

    denitrification momentarily occurs. This approach serves to increase the denitrification rate on demand, thereby allowing the accumulation of nitrate and nitrite during periods of peak nitrogen loading to be reduced or avoided. A pilot plant demonstration of the control strategy using acetate as COD source is...... provided, showing a marked improvement in effluent water quality as compared to the uncontrolled case. An examination of the resulting denitrification rates illustrates the direct proportionality between these rates and the rate of COD addition....

  17. Intensified nitrogen removal in immobilized nitrifier enhanced constructed wetlands with external carbon addition.

    Wang, Wei; Ding, Yi; Wang, Yuhui; Song, Xinshan; Ambrose, Richard F; Ullman, Jeffrey L

    2016-10-01

    Nitrogen removal performance response of twelve constructed wetlands (CWs) to immobilized nitrifier pellets and different influent COD/N ratios (chemical oxygen demand: total nitrogen in influent) were investigated via 7-month experiments. Nitrifier was immobilized on a carrier pellet containing 10% polyvinyl alcohol (PVA), 2.0% sodium alginate (SA) and 2.0% calcium chloride (CaCl2). A batch experiment demonstrated that 73% COD and 85% ammonia nitrogen (NH4-N) were degraded using the pellets with immobilized nitrifier cells. In addition, different carbon source supplement strategies were applied to remove the nitrate (NO3-N) transformed from NH4-N. An increase in COD/N ratio led to increasing reduction in NO3-N. Efficient nitrification and denitrification promoted total nitrogen (TN) removal in immobilized nitrifier biofortified constructed wetlands (INB-CWs). The results suggested that immobilized nitrifier pellets combined with high influent COD/N ratios could effectively improve the nitrogen removal performance in CWs. PMID:27396293

  18. Structures of Equatorial Envelope Rossby Wave Under a Generalized External Forcing

    FUZun-Tao; LIUShi-Da; LIUShi-Kuo

    2004-01-01

    The cubic nonlinear Schroedinger (NLS for short) equation with a generalized external heating source is derived for large amplitude equatorial envelope Rossby wave in a shear flow. And then various periodic structures for these equatorial cnvelope Rossby waves are obtained with the help of a new transformation, Jacobi elliptic functions,and elliptic equation. It is shown that different types of resonant phase-locked diabatic heating play different roles in structures of equatorial envelope Rossby wave.

  19. Structures of Equatorial Envelope Rossby Wave Under a Generalized External Forcing

    FU Zun-Tao; LIU Shi-Da; LIU Shi-Kuo

    2004-01-01

    The cubic nonlinear Schrodinger (NLS for short) equation with a generalized external heating source is derived for large amplitude equatorial envelope Rossby wave in a shear flow. And then various periodic structures for these equatorial envelope Rossby waves are obtained with the help of a new transformation, Jacobi elliptic functions,and elliptic equation. It is shown that different types of resonant phase-locked diabatic heating play different roles in structures of equatorial envelope Rossby wave.

  20. Influence of Additional Tensile Force on Springback of Tube Under Rotary Draw Bending

    E, Daxin; Guan, Zhiping; Chen, Jisheng

    2012-11-01

    According to the characteristics of tube under rotary draw bending, the formulae were derived to calculate the springback angles of tubes subjected to combined bending and additional tension. Especially, as the neutral layer (NL) moves to the inner concave surface of the bend, the analytical values agree very well with the experimental results. The analysis shows that the additional tensile force causes the movement of the NL toward the bending center and makes the deformation behavior under rotary draw bending or numerically controlled (NC) bending different with that under pure bending, and also it could enlarge the springback angle if taking the movement of the NL into consideration. In some range, the springback angle would increase slightly with larger wall thickness/diameter ratio and decrease with wall thinning. The investigation could provide reference for the analysis of rotary draw bending, the design of NC tube bender and the related techniques.

  1. Vibration localization of a mistuned rotating multi-packet blade system undergoing external cyclic harmonic force

    A multi-packet blade system consists of several blades which are attached to a disk and connected through shrouds. The blades of a multi-packet blade system are usually assumed to be identical. However, there always exists small, random mistuning among the blades due to manufacturing tolerance, in-operation wear and environmental changes. Such mistuning may cause significant increase in the forced vibration responses of some blades in the multi-packet blade system. Critical fatigue problems often occur in mistuned systems since the forced vibration response of a mistuned system is often significantly larger than that of a tuned system. Therefore, it is very important to predict the maximum blade response. In this study, blades are idealized as cantilever beams and the flexibilities of the disk and shrouds are idealized as discrete springs. Equations of motion are derived using the hybrid deformation variable method. To realize vibration localization with random mistuning, transient analysis is carried out for a multi-packet blade system excited by multiple nozzle jet forces

  2. Pipeline integrity management: integration of geotechnical and mechanical assessment to control potential risks due to external forces

    Malpartida Moya, John E.; Sota, Giancarlo Massucco de la; Seri, Walter [Compania Operadora de Gas del Amazonas, Lima (Peru)

    2009-07-01

    Every pipeline integrity management system evaluates and controls various threats. On pipelines which have particular characteristics as it is the case of the Andean pipelines and pipelines crossing jungles, one of the main threats are the external forces. Even, this threat causes a greater number of failures than other threats like corrosion or the third part damage. Facing this situation, the pipeline integrity management system of TgP has achieved an important development in the use and suitable handling of the information provided by diverse techniques of pipeline mechanical inspection and geotechnical inspection of the right-of-way (ROW). This document presents our methodology, which interrelate information of the in-line inspection, information of geotechnical inspections of the ROW, instrumentation (Strain Gages), topographic monitoring, among others. All this information is supported in a Geographic Information System (GIS) which allows us to integrate the information. By means of the pipeline integrity management system we control potential risks due to external forces, we have been able to act before events become critical, with no occurrence of failures. This system allows us simultaneously to optimize efforts and preserve the mechanical integrity of our pipelines, not producing neither personal nor environmental nor economical affectation. (author)

  3. Quasi-two-layer finite-volume scheme for modeling shallow water flows with the presence of external forces

    Karelsky, K V; Slavin, A G

    2011-01-01

    The numerical method for study of hydrodynamic flows over an arbitrary bed profile in the presence of external force is proposed in this paper. This method takes into account the external force effect, it uses the quasi-two-layer model of hydrodynamic flows over a stepwise boundary with consideration of features of the flow near the step. A distinctive feature of the proposed method is the consideration of the properties of the process of the waterfall, namely the fluid flow on the step in which the fluid does not wet part of the vertical wall of the step. The presence of dry zones in the vertical part of the step indicates violation of the conditions of hydrostatic flow. The quasi-two-layer approach allows to determine the size of the dry zone of the vertical component of the step. Consequently it gives an opportunity to figure out the amount of kinetic energy dissipation. There are performed the numerical simulations based on the proposed algorithm of various physical phenomena, such as a breakdown of the r...

  4. Noise-sustained synchronization of electrically coupled FitzHugh-Nagumo networks under counterphase external forcing

    Sánchez, Alejandro D.; Izús, Gonzalo G.

    2016-05-01

    We study the stochastic dynamics of two electrically coupled networks of excitable FitzHugh-Nagumo cells, each of them phase-repulsively linked to form a ring able to develop noise-sustained structures. All cells are submitted to Gaussian white noises with common intensity η, while each network is forced with opposite phase by an adiabatic subthreshold harmonic signal. In terms of the nonequilibrium potential of a four-cell reduced model we have interpreted the dynamics, explained the observed activation and synchronization of the structures, and calculated the optimal η level as a function of coupling strength between networks. The values obtained from the reduced model coincide in order of magnitude with those arising from numerical simulations of the full system.

  5. Detrended partial cross-correlation analysis of two nonstationary time series influenced by common external forces

    Qian, Xi-Yuan; Liu, Ya-Min; Jiang, Zhi-Qiang; Podobnik, Boris; Zhou, Wei-Xing; Stanley, H. Eugene

    2015-06-01

    When common factors strongly influence two power-law cross-correlated time series recorded in complex natural or social systems, using detrended cross-correlation analysis (DCCA) without considering these common factors will bias the results. We use detrended partial cross-correlation analysis (DPXA) to uncover the intrinsic power-law cross correlations between two simultaneously recorded time series in the presence of nonstationarity after removing the effects of other time series acting as common forces. The DPXA method is a generalization of the detrended cross-correlation analysis that takes into account partial correlation analysis. We demonstrate the method by using bivariate fractional Brownian motions contaminated with a fractional Brownian motion. We find that the DPXA is able to recover the analytical cross Hurst indices, and thus the multiscale DPXA coefficients are a viable alternative to the conventional cross-correlation coefficient. We demonstrate the advantage of the DPXA coefficients over the DCCA coefficients by analyzing contaminated bivariate fractional Brownian motions. We calculate the DPXA coefficients and use them to extract the intrinsic cross correlation between crude oil and gold futures by taking into consideration the impact of the U.S. dollar index. We develop the multifractal DPXA (MF-DPXA) method in order to generalize the DPXA method and investigate multifractal time series. We analyze multifractal binomial measures masked with strong white noises and find that the MF-DPXA method quantifies the hidden multifractal nature while the multifractal DCCA method fails.

  6. Review of the formulation of present-generation stratospheric chemistry-climate models and associated external forcings

    Morgenstern, O.; Giorgetta, M. A.; Shibata, K.; Eyring, V.; Waugh, D. W.; Shepherd, T. G.; Akiyoshi, H.; Austin, J.; Baumgaertner, A. J. G.; Bekki, S.; Braesicke, P.; Brühl, C.; Chipperfield, M. P.; Cugnet, D.; Dameris, M.; Dhomse, S.; Frith, S. M.; Garny, H.; Gettelman, A.; Hardiman, S. C.; Hegglin, M. I.; JöCkel, P.; Kinnison, D. E.; Lamarque, J.-F.; Mancini, E.; Manzini, E.; Marchand, M.; Michou, M.; Nakamura, T.; Nielsen, J. E.; Olivié, D.; Pitari, G.; Plummer, D. A.; Rozanov, E.; Scinocca, J. F.; Smale, D.; TeyssèDre, H.; Toohey, M.; Tian, W.; Yamashita, Y.

    2010-01-01

    The goal of the Chemistry-Climate Model Validation (CCMVal) activity is to improve understanding of chemistry-climate models (CCMs) through process-oriented evaluation and to provide reliable projections of stratospheric ozone and its impact on climate. An appreciation of the details of model formulations is essential for understanding how models respond to the changing external forcings of greenhouse gases and ozone-depleting substances, and hence for understanding the ozone and climate forecasts produced by the models participating in this activity. Here we introduce and review the models used for the second round (CCMVal-2) of this intercomparison, regarding the implementation of chemical, transport, radiative, and dynamical processes in these models. In particular, we review the advantages and problems associated with approaches used to model processes of relevance to stratospheric dynamics and chemistry. Furthermore, we state the definitions of the reference simulations performed, and describe the forcing data used in these simulations. We identify some developments in chemistry-climate modeling that make models more physically based or more comprehensive, including the introduction of an interactive ocean, online photolysis, troposphere-stratosphere chemistry, and non-orographic gravity-wave deposition as linked to tropospheric convection. The relatively new developments indicate that stratospheric CCM modeling is becoming more consistent with our physically based understanding of the atmosphere.

  7. Molecular dynamics study of response of liquid N,N-dimethylformamide to externally applied electric field using a polarizable force field

    Gao, Weimin; Niu, Haitao; Lin, Tong; Wang, Xungai; Kong, Lingxue [Institute for Frontier Materials, Deakin University, Waurn Ponds VIC 3216 (Australia)

    2014-01-28

    The behavior of Liquid N,N-dimethylformamide subjected to a wide range of externally applied electric fields (from 0.001 V/nm to 1 V/nm) has been investigated through molecular dynamics simulation. To approach the objective the AMOEBA polarizable force field was extended to include the interaction of the external electric field with atomic partial charges and the contribution to the atomic polarization. The simulation results were evaluated with quantum mechanical calculations. The results from the present force field for the liquid at normal conditions were compared with the experimental and molecular dynamics results with non-polarizable and other polarizable force fields. The uniform external electric fields of higher than 0.01 V/nm have a significant effect on the structure of the liquid, which exhibits a variation in numerous properties, including molecular polarization, local cluster structure, rotation, alignment, energetics, and bulk thermodynamic and structural properties.

  8. Molecular dynamics study of response of liquid N,N-dimethylformamide to externally applied electric field using a polarizable force field

    Gao, Weimin; Niu, Haitao; Lin, Tong; Wang, Xungai; Kong, Lingxue

    2014-01-01

    The behavior of Liquid N,N-dimethylformamide subjected to a wide range of externally applied electric fields (from 0.001 V/nm to 1 V/nm) has been investigated through molecular dynamics simulation. To approach the objective the AMOEBA polarizable force field was extended to include the interaction of the external electric field with atomic partial charges and the contribution to the atomic polarization. The simulation results were evaluated with quantum mechanical calculations. The results from the present force field for the liquid at normal conditions were compared with the experimental and molecular dynamics results with non-polarizable and other polarizable force fields. The uniform external electric fields of higher than 0.01 V/nm have a significant effect on the structure of the liquid, which exhibits a variation in numerous properties, including molecular polarization, local cluster structure, rotation, alignment, energetics, and bulk thermodynamic and structural properties.

  9. Molecular dynamics study of response of liquid N,N-dimethylformamide to externally applied electric field using a polarizable force field

    The behavior of Liquid N,N-dimethylformamide subjected to a wide range of externally applied electric fields (from 0.001 V/nm to 1 V/nm) has been investigated through molecular dynamics simulation. To approach the objective the AMOEBA polarizable force field was extended to include the interaction of the external electric field with atomic partial charges and the contribution to the atomic polarization. The simulation results were evaluated with quantum mechanical calculations. The results from the present force field for the liquid at normal conditions were compared with the experimental and molecular dynamics results with non-polarizable and other polarizable force fields. The uniform external electric fields of higher than 0.01 V/nm have a significant effect on the structure of the liquid, which exhibits a variation in numerous properties, including molecular polarization, local cluster structure, rotation, alignment, energetics, and bulk thermodynamic and structural properties

  10. Prospective randomised trial on the role of HDR-brachytherapy in addition to external beam radiotherapy for central bronchial carcinoma

    Objective: In a prospective, randomised trial we investigated the influence of additional High-Dose-Rate-(HDR)-brachytherapy on tumor control and overall survival of patients suffering from inoperable central lung tumors treated with loco-regional external beam radiotherapy (EB-RT). Special attention was given to dose limiting side effects. Methods: Patients randomised in group A received loco-regional EB-RT up to 50 Gy (5 x 2 Gy per week), followed by a boost of 10 Gy also 2 Gy 5 times a week to the primary and adjacent lymphonodular metastases. Patients in group B additionally received an endoluminal HDR-afterloading-radiotherapy (192Ir) with 10 Gy calculated for 5 mm depth one week before and three weeks after EB-RT. Due to the advanced tumor stage, none of the patients received surgery before irradiation. Patients treated with chemotherapy were excluded from the study. Results: Until February 1996 all of 98 patients were evaluated. Both groups are comparable regarding age, gender, Karnofsky Performance State, tumor stage (mostly stage IIIb and IV) and histology. Squamous cell carcinoma (SCC) were found in 69%, whereas the rest consisted of adeno carcinoma (15%), large cell carcinoma (6%) and non small cell carcinoma (NSCLC) (10%), all subsets equally distributed between group A and B. Local control in group A (n=42) lasted for a median of 12 weeks, in group B (n=56) for a median of 21 weeks, a difference which is just significant (p≤0,05). The median overall survival was nearly identical (28 weeks). The subgroup of SCC, however, showed a median survival of 33 (group A) versus 40 weeks (group B), a difference which is not significant (p≤0.09), but might indicate an advantage for this histological group. The most serious side effect was fatal bleeding with 15% in group A and 21% in group B. Conclusions: At present, this study reveals improved local control by a boost of 2x10 Gy 192Ir-HDR-AL in addition to definitive EB-RT (group B) compared to EB-RT alone

  11. Force.

    Gamble, Reed

    1989-01-01

    Discusses pupil misconceptions concerning forces. Summarizes some of Assessment of Performance Unit's findings on meaning of (1) force, (2) force and motion in one dimension and two dimensions, and (3) Newton's second law. (YP)

  12. Focal enhancement of the skeleton to exercise correlates with responsivity of bone marrow mesenchymal stem cells rather than peak external forces.

    Wallace, Ian J; Pagnotti, Gabriel M; Rubin-Sigler, Jasper; Naeher, Matthew; Copes, Lynn E; Judex, Stefan; Rubin, Clinton T; Demes, Brigitte

    2015-10-01

    Force magnitudes have been suggested to drive the structural response of bone to exercise. As importantly, the degree to which any given bone can adapt to functional challenges may be enabled, or constrained, by regional variation in the capacity of marrow progenitors to differentiate into bone-forming cells. Here, we investigate the relationship between bone adaptation and mesenchymal stem cell (MSC) responsivity in growing mice subject to exercise. First, using a force plate, we show that peak external forces generated by forelimbs during quadrupedal locomotion are significantly higher than hindlimb forces. Second, by subjecting mice to treadmill running and then measuring bone structure with μCT, we show that skeletal effects of exercise are site-specific but not defined by load magnitudes. Specifically, in the forelimb, where external forces generated by running were highest, exercise failed to augment diaphyseal structure in either the humerus or radius, nor did it affect humeral trabecular structure. In contrast, in the ulna, femur and tibia, exercise led to significant enhancements of diaphyseal bone areas and moments of area. Trabecular structure was also enhanced by running in the femur and tibia. Finally, using flow cytometry, we show that marrow-derived MSCs in the femur are more responsive to exercise-induced loads than humeral cells, such that running significantly lowered MSC populations only in the femur. Together, these data suggest that the ability of the progenitor population to differentiate toward osteoblastogenesis may correlate better with bone structural adaptation than peak external forces caused by exercise. PMID:26232415

  13. Establishment and validation of standardized animal models of spinal cord injury by normal external force-caused fracture dislocation

    Weibing Shuang; Qiang Liu; Shoubin Jiao; Yang Yang

    2011-01-01

    The duplication of animal models plays a key role in spinal cord injury research; however, there has been limited study into normal, external force-derived fracture dislocation. This study adopted experimental devices, designed in-house, to construct standardized ventral and dorsal spinal cord injury animal models of 6 g and 17 g falling from a height of 2, 4, and 10 cm, and 15, 30 or 50 g transversal compression on the spinal cord. The results showed that gradual increases in the degree of histopathological injury led to decreased Tarlov and Basso, Beattie and Bresnahan scores for the behavioral test, and increased Ashworth scores for the hind limb. Furthermore, there was a gradual decline in the slope test in the rats with dorsal spinal cord injury that correlated to increases in the falling substance weight or falling height. Similar alterations were observed in the ventral spinal cord injured rats, proportional to the increase in compression weight. Our experimental findings indicate that the standardized experimental rat models of dorsal and ventral spinal cord injury are stable, reliable and reproducible.

  14. Long-time behavior for a nematic liquid crystal model with asymptotic stabilizing boundary condition and external force

    Grasselli, Maurizio

    2011-01-01

    We consider an approximation of the well-known Ericksen-Leslie model for the nematic liquid crystal flow proposed by F.-H. Lin et al. The evolution system consists of the Navier-Stokes equations coupled with a convective Ginzburg-Landau type equation for the (vector-valued) averaged molecular orientations. Here we suppose that the latter is subject to a time-dependent Dirichlet boundary condition h(t), while the Navier--Stokes equations are characterized by a no-slip boundary condition and by a time-dependent external force g(t). We show that, in 2D, each global weak solution converges to a single stationary state when h(t) and g(t) suitably converge to a time-independent boundary datum h_\\infty and 0, respectively. We also provide some estimates of the convergence rate. In the 3D case, we prove a similar long-time behavior for global strong solutions, provided that either the viscosity is large enough or the initial datum is close to a given equilibrium.

  15. The scaled-charge additive force field for amino acid based ionic liquids

    Fileti, E. E.; Chaban, V. V.

    2014-01-01

    Ionic liquids (ILs) constitute an emerging research field. New ILs involve more and more organic and inorganic ions. Amino acid based ILs (AAILs) represent a specific interest due to their evolutional connection to proteins. We report a new non-polarizable force field (FF) for the eight AAILs...

  16. Diastereoselective Addition of α-Metalated Sulfoxides to Imines Revisited: Mechanism, Computational Studies, and the Effect of External Chiral Ligands

    Pedersen, Brian; Rein, Tobias; Søtofte, Inger;

    2003-01-01

    six-membered "flat chair") was probed by quantum mechanical calculations, which underpinned the idea of using external chiral ligands to enhance the diastereoselectivity of otherwise moderately selective reactions. In this way, the diastereomeric ratio of the product 3a could be raised from (84 : 16...

  17. Addition of Electrostatic Forces to EDEM with Applications to Triboelectrically Charged Particles

    Hogue, Michael D.; Calle, Carlos; Curry, David

    2008-01-01

    Tribocharging of particles is common in many processes including fine powder handling and mixing, printer toner transport and dust extraction. In a lunar environment with its high vacuum and lack of water, electrostatic forces are an important factor to consider when designing and operating equipment. Dust mitigation and management is critical to safe and predictable performance of people and equipment. The extreme nature of lunar conditions makes it difficult and costly to carryout experiments on earth which are necessary to better understand how particles gather and transfer charge between each other and with equipment surfaces. DEM (Discrete Element Modeling) provides an excellent virtual laboratory for studying tribocharging of particles as well as for design of devices for dust mitigation and for other purposes related to handling and processing of lunar regolith. Theoretical and experimental work has been performed pursuant to incorporating screened Coulombic electrostatic forces into EDEM Tm, a commercial DEM software package. The DEM software is used to model the trajectories of large numbers of particles for industrial particulate handling and processing applications and can be coupled with other solvers and numerical models to calculate particle interaction with surrounding media and force fields. In this paper we will present overview of the theoretical calculations and experimental data and their comparison to the results of the DEM simulations. We will also discuss current plans to revise the DEM software with advanced electrodynamic and mechanical algorithms.

  18. Force acting on a dielectric particle in a concentration gradient by ionic concentration polarization under an externally applied DC electric field.

    Kang, Kwan Hyoung; Li, Dongqing

    2005-06-15

    There is a concentration-polarization (CP) force acting on a particle submerged in an electrolyte solution with a concentration (conductivity) gradient under an externally applied DC electric field. This force originates from the two mechanisms: (i) gradient of electrohydrodynamic pressure around the particle developed by the Coulombic force acting on induced free charges by the concentration polarization, and (ii) dielectric force due to nonuniform electric field induced by the conductivity gradient. A perturbation analysis is performed for the electric field, the concentration field, and the hydrodynamic field, under the assumptions of creeping flow and small concentration gradient. The leading order component of this force acting on a dielectric spherical particle is obtained by integrating the Maxwell and the hydrodynamic stress tensors. The analytical results are validated by comparing the surface pressure and the skin friction to those of a numerical analysis. The CP force is proportional to square of the applied electric field, effective for electrically neutral particles, and always directs towards the region of higher ionic concentration. The magnitude of the CP force is compared to that of the electrophoretic and the conventional dielectrophoretic forces. PMID:15897097

  19. Magnetic Force Microscopy Study of Zr2Co11-Based Nanocrystalline Materials: Effect of Mo Addition

    Lanping Yue; Yunlong Jin; Wenyong Zhang; Sellmyer, David J.

    2015-01-01

    The addition of Molybdenum was used to modify the nanostructure and enhance coercivity of rare-earth-free Zr2Co11-based nanocrystalline permanent magnets. The effect of Mo addition on magnetic domain structures of melt spun nanocrystalline Zr16Co84-xMox (x=0, 0.5, 1, 1.5, and 2.0) ribbons has been investigated. It was found that magnetic properties and local domain structures are strongly influenced by Mo doping. The coercivity of the samples increases with the increase in Mo content (x≤1.5)....

  20. PARAMETER DETERMINATION FOR ADDITIONAL OPERATING FORCE MECHANISM IN DEVICE FOR PNEUMO-CENTRIFUGAL MACHINING OF BALL-SHAPED WORKPIECES

    A. A. Sukhotsky

    2015-01-01

    Full Text Available The paper describes development of the methodology for optimization of parameters for an additional operating force mechanism in a device for pneumo-centrifugal machining of glass balls. Specific feature in manufacturing glass balls for micro-optics in accordance with technological process for obtaining ball-shaped workpieces is grinding and polishing of spherical surface in a free state. In this case component billets of future balls are made in the form of cubes and the billets are given preliminary a form of ball with the help of rough grinding. An advanced method for obtaining ball-shaped work-pieces from brittle materials is a pneumocentrifugal machining. This method presupposes an application of two conic rings with abrasive working surfaces which are set coaxially with large diameters to each other and the billets are rolled along these rings. Rotation of the billets is conveyed by means of pressure medium.The present devices for pneumo-centrifugal machining are suitable for obtaining balls up to 6 mm. Machining of the work-pieces with full spherical surfaces and large diameter is non-productive due to impossibility to ensure a sufficient force on the billet in the working zone. For this reason the paper proposes a modified device where an additional force on the machined billet is created by upper working disc that is making a reciprocating motion along an axis of abrasive conic rings. The motion is realized with the help of a cylindrical camshaft mechanism in the form of a ring with a profile working end face and the purpose of present paper is to optimize parameters of the proposed device.The paper presents expressions for calculation of constitutive parameters of the additional operating force mechanism including parameters of loading element motion, main dimensions of the additional operating force mechanism and parameters of a profile element in the additional operating force mechanism.Investigation method is a mathematical

  1. The entry into force of the Additional Protocol in the European Union: The new dimension of safeguards in Europe

    Recio, M. [Deputy Direction General for Nuclear Energy, Direction General for Energy Policy and Mines Ministry of Industry, Tourism and Trade, Paseo de la Castellana, 160 Madrid 28046 (Spain)]. E-mail: MRecio@mityc.es; Prieto, N. [Asesoria Juridica, Direccion de Division Administracion, Enresa, c/Emilio Vargas, 7, Madrid 28043 (Spain)]. E-mail: nprs@enresa.es

    2006-07-01

    The Additional Protocol to the Safeguards Agreement with the International Atomic Energy Agency (IAEA) has entered into force on 30 April 2004. This completes the implementation in the EU of what undoubtedly represents the most ambitious project undertaken by the IAEA, designed to reinforce its current safeguards system, a project that the international community considers to be a key component strengthening the fight against one of the most serious threats for world security: nuclear proliferation. (author)

  2. The CSIRO Mk3L climate system model version 1.0 – Part 2: Response to external forcings

    S. J. Phipps

    2012-05-01

    Full Text Available The CSIRO Mk3L climate system model is a coupled general circulation model, designed primarily for millennial-scale climate simulation and palaeoclimate research. Mk3L includes components which describe the atmosphere, ocean, sea ice and land surface, and combines computational efficiency with a stable and realistic control climatology. It is freely available to the research community. This paper evaluates the response of the model to external forcings which correspond to past and future changes in the climate system.

    A simulation of the mid-Holocene climate is performed, in which changes in the seasonal and meridional distribution of incoming solar radiation are imposed. Mk3L correctly simulates increased summer temperatures at northern mid-latitudes and cooling in the tropics. However, it is unable to capture some of the regional-scale features of the mid-Holocene climate, with the precipitation over Northern Africa being deficient. The model simulates a reduction of between 7 and 15% in the amplitude of El Niño-Southern Oscillation, a smaller decrease than that implied by the palaeoclimate record. However, the realism of the simulated ENSO is limited by the model's relatively coarse spatial resolution.

    Transient simulations of the late Holocene climate are then performed. The evolving distribution of insolation is imposed, and an acceleration technique is applied and assessed. The model successfully captures the temperature changes in each hemisphere and the upward trend in ENSO variability. However, the lack of a dynamic vegetation scheme does not allow it to simulate an abrupt desertification of the Sahara.

    To assess the response of Mk3L to other forcings, transient simulations of the last millennium are performed. Changes in solar irradiance, atmospheric greenhouse gas concentrations and volcanic emissions are applied to the model. The model is again broadly successful at simulating larger-scale changes in the

  3. The CSIRO Mk3L climate system model version 1.0 – Part 2: Response to external forcings

    A. C. Hirst

    2011-12-01

    Full Text Available The CSIRO Mk3L climate system model is a coupled general circulation model, designed primarily for millennial-scale climate simulation and palaeoclimate research. Mk3L includes components which describe the atmosphere, ocean, sea ice and land surface, and combines computational efficiency with a stable and realistic control climatology. It is freely available to the research community. This paper evaluates the response of the model to external forcings which correspond to past and future changes in the climate system. A simulation of the mid-Holocene climate is performed, in which changes in the seasonal and meridional distribution of incoming solar radiation are imposed. Mk3L correctly simulates increased summer temperatures at northern mid-latitudes and cooling in the tropics. However, it is unable to capture some of the regional-scale features of the mid-Holocene climate, with the precipitation over Northern Africa being deficient. The model simulates a reduction of between 7 and 15% in the amplitude of El Niño-Southern Oscillation, a smaller decrease than that implied by the palaeoclimate record. However, the realism of the simulated ENSO is limited by the model's relatively coarse spatial resolution. Transient simulations of the late Holocene climate are then performed. The evolving distribution of insolation is imposed, and an acceleration technique is applied and assessed. The model successfully captures the temperature changes in each hemisphere and the upward trend in ENSO variability. However, the lack of a dynamic vegetation scheme does not allow it to simulate an abrupt desertification of the Sahara. To assess the response of Mk3L to other forcings, transient simulations of the last millennium are performed. Changes in solar irradiance, atmospheric greenhouse gas concentrations and volcanic emissions are applied to the model. The model is again broadly successful at simulating larger-scale changes in the climate system. Both the

  4. Effect of Feed Additive on Base of L-carnitine in Drinking Water on Internal and External Egg Quality

    Cyril Hrnčár; Martin Gašparovič; Ján Weis; Henrieta Arpášová; Veronika Pistová; Martin Fik; Jozef Bujko

    2016-01-01

    The objective of present study was to investigate the effect of feed additive on base of L-carnitine (30%) on some parameters of egg quality. Totally 40 White Leghorn laying hens were divided in two groups: control group (n=20) received drinking water without any additives and experimental group (n=20) received feed additive in dose 1 ml per 1.2 l of drinking water for a period of 5 days in 2 week intervals from 26 to 56 week of age. Hens in both groups were feeding ad libitum with commercial...

  5. Coriolis Force Mass-Flow Meter Composed of a Straight Pipe and an Additional Resonance-Vibrator

    Tsutsui, Hirohide; Tomikawa, Yoshiro

    1993-05-01

    This paper deals with a new construction for a mass-flow meter using Coriolis force, and its basic experimental results. Some Coriolis force mass-flow meters, proposed up to now, are of a twin construction of, for example, a U-type pipe or a straight-type pipe, where the mass-flow is determined by measuring the relative displacement between the pipes. Therefore, their structure is too complex. To improve this situation, the authors propose a new mass-flow meter using one straight pipe, together with an additional flexural resonance-vibrator. The experimental results prove that a mass-flow meter can be realized by such a simple construction as dealt with here.

  6. STUDY OF STATIC AND DYNAMIC STABILITY OF THIN-WALLED BARS EXCITED BY PERIODICAL AXIAL EXTERNAL FORCES.

    Minodora Maria PASĂRE

    2010-10-01

    Full Text Available In these paper, starting from the relations for the displacements and spinning the transversal section of a bar with thin walls of sections opened expressed by the corresponding influence functions and introducing the components of the exterior forces distributed and the moments of the exterior forces distributed due to the inertia forces, the exciting axial forces together with the following effect of these and of the reaction forces of the elastic environment for leaning it may reach to the system of the equations of parametric vibrations under the form of three integral equation These equations may serve for the study of vibrations of the bars, to study the static stability and to study the dynamic stability

  7. Surface electromyography activity of the rectus abdominis, internal oblique, and external oblique muscles during forced expiration in healthy adults.

    Ito, Kenichi; Nonaka, Koji; Ogaya, Shinya; Ogi, Atsushi; Matsunaka, Chiaki; Horie, Jun

    2016-06-01

    We aimed to characterize rectus abdominis, internal oblique, and external oblique muscle activity in healthy adults under expiratory resistance using surface electromyography. We randomly assigned 42 healthy adult subjects to 3 groups: 30%, 20%, and 10% maximal expiratory intraoral pressure (PEmax). After measuring 100% PEmax and muscle activity during 100% PEmax, the activity and maximum voluntary contraction of each muscle during the assigned experimental condition were measured. At 100% PEmax, the external oblique (pexpiration. Moreover, 30% PEmax is the minimum intensity required to achieve significant, albeit very slight, muscle activity during expiratory resistance. PMID:27077819

  8. Influence of Zeolite Additive on the Properties of Plaster Used for External Walls from Autoclaved Aerated Concrete

    Georgijus SEZEMANAS

    2013-05-01

    Full Text Available Enclosures that had been built from elements of autoclaved aerated concrete (AAC often are covered with plasters. Some adhesion problems between plasters and surface exist during the mechanized covering of surfaces of the mentioned enclosures with plaster. Some dispersible additives (vinyl acetate polymer or derivatives of acrylic acid esters are used to improve the adhesion. Another problem is the increased water absorption of AAC elements, therefore water retarding additives (cellulose esters are used in the mixture of plasters. Due to insufficient amount of water in the mixture of plasters, the hydration of cement minerals slows down. Influence of the natural zeolite – clinoptilolite on the properties of plaster is analyzed in this work. It was found that this additive effectively absorbs water and thus, ensures adequate hydration of cement minerals. When in the mixture of plaster the sand is changed by clinoptilolite in amount of 15 % the structure slightly compacts, the compressive and flexural strength of hardened plaster increase by 47 % and 12 % respectively and the adhesion to a surface of the AAC element increases by 44 %. Drying shrinkage, water vapor resistance factor and coefficient of capillary absorption remain unchanged.DOI: http://dx.doi.org/10.5755/j01.ms.19.2.4441

  9. Lessons Learned at the Idaho National Laboratory for the Entry into Force of the U.S. Additional Protocol

    For a number of years, the Idaho National Laboratory (INL) has been preparing for the entry into force of the U.S. Additional Protocol (AP). These preparations included attending training, participating in tabletop exercises, preparing draft declarations, developing INL-specific guidance documents, preparing for and hosting a mock complementary access visit, and preparing declarations for official submittal. All of these activities, the training materials, and software developed by other U.S. DOE national laboratories (PNNL, ORNL, LANL, and BNL) were very helpful in preparing for the entry into force of the AP. As with any endeavor of this size and complexity, however, there are always instances where even the best preparations and advanced planning do not anticipate every challenge. As the DOE's lead nuclear energy research and development facility, the INL faced many unique challenges. The majority of research conducted at the INL is nuclear fuel cycle related, most of which is not protected by the National Security Exclusion. This paper describes the lessons learned from the INL's experience of preparing for the entry into force of the AP, specifically how translating and implementing general principles into actual activities proved to be one of many challenges, and provides general suggestions on how to respond effectively and efficiently to routine annual data calls and other AP requests

  10. Resonance scattering and radiation force calculations for an elastic cylinder using the translational addition theorem for cylindrical wave functions

    The standard Resonance Scattering Theory (RST) of plane waves is extended for the case of any two-dimensional (2D) arbitrarily-shaped monochromatic beam incident upon an elastic cylinder with arbitrary location using an exact methodology based on Graf’s translational addition theorem for the cylindrical wave functions. The analysis is exact as it does not require numerical integration procedures. The formulation is valid for any cylinder of finite size and material that is immersed in a nonviscous fluid. Partial-wave series expansions (PWSEs) for the incident, internal and scattered linear pressure fields are derived, and the analysis is further extended to obtain generalized expressions for the on-axis and off-axis acoustic radiation force components. The wave-fields are expressed using generalized PWSEs involving the beam-shape coefficients (BSCs) and the scattering coefficients of the cylinder. The off-axial BSCs are expressed analytically in terms of an infinite PWSE with emphasis on the translational offset distance d. Numerical computations are considered for a zeroth-order quasi-Gaussian beam chosen as an example to illustrate the analysis. Acoustic resonance scattering directivity diagrams are calculated by subtracting an appropriate background from the expression of the scattered pressure field. In addition, computations for the radiation force exerted on an elastic cylinder centered on the axis of wave propagation of the beam, and shifted off-axially are analyzed and discussed

  11. Effects of additional external weight on posture and movement adaptations to fatigue induced by a repetitive pointing task.

    Cantú, Hiram; Emery, Kim; Côté, Julie N

    2014-06-01

    Fatigue and additional weight are risk factors of injuries by falls. Posture and trunk movement changes occur with fatigue induced by a repetitive pointing task. These changes facilitate arm movement but they may also jeopardize postural stability. When equilibrium is challenged, e.g. with additional weight, strategies that represent less postural threat could develop with fatigue. Nineteen participants performed two sessions (without, with 20% body weight added load (Load)) of a repetitive pointing task until shoulder fatigue (8 on Borg CR-10). There was no difference in time to fatigue between the two sessions. Anterior deltoid, biceps and upper trapezius muscle activity significantly increased with fatigue. Peak medial-lateral center-of-pressure (CoP) velocity and the mean vertical position of the reaching shoulder were both significantly lower with fatigue, though these fatigue-induced decreases were smaller with the added load. Reach-to-reach variability in CoP displacement significantly increased with fatigue, and more so with the added load. With fatigue, significant contralateral shifts occurred at the reaching shoulder and elbow joints, and ranges of motion (RoM) significantly increased at most joints but not at the center-of-mass (CoM). Conversely, Load main effects were mostly seen in CoM dependent measures. Significantly increased variability in mean and range values was seen with fatigue and Load in most of our kinematic and CoP dependent measures, with the most notable effects on CoM dependent measures. Findings suggest that the postural control system adapts to combined perturbing factors of fatigue and added load, likely by using parallel control mechanisms. PMID:24786737

  12. [Changes in the efferent activity of the scratching generator evoked by external mechanical force applied to a hindlimb in the decerebrate cat].

    Chigarev, Iu V

    1991-01-01

    Changes in the afferent inflow appeared with application of the external mechanical force to the rhythmically moving hindlimb have been studied for their scratching generator activity in decerebrate adult cats. Phasic relationship between violent hindlimb transference and efferent activity of the scratching generator was opposite to that found earlier during fictitious scratching, which is explained by difference between afferent activity during real scratching movement and passive movement of the hindlimb in the immobilized animal. Maximum redistribution in the relationship between flexor and extensor intensities in response to the stimulation corresponds to maximum rate of the violent hindlimb transference. PMID:1798420

  13. The low-energy theorem for the forward Compton amplitude of a stationary composite system and the FW additive external electromagnetic interaction

    It is shown that the low-energy theorem for the forward Compton amplitude of a stationary composite system in states with nonzero internal orbital angular momentum can only be verified with the use of the FW additive external electromagnetic interaction to order 1/M3 together with the relativistic c.m. variables to order 1/M2, contrary to what is usually believed. The theorem is also explicitly demonstrated even when both the constituent particles of the composite system are electrically charged. (author)

  14. Forced magnetic reconnection and field penetration of an externally applied rotating helical magnetic field in the TEXTOR tokamak.

    Kikuchi, Y; de Bock, M F M; Finken, K H; Jakubowski, M; Jaspers, R; Koslowski, H R; Kraemer-Flecken, A; Lehnen, M; Liang, Y; Matsunaga, G; Reiser, D; Wolf, R C; Zimmermann, O

    2006-08-25

    The magnetic field penetration process into a magnetized plasma is of basic interest both for plasma physics and astrophysics. In this context special measurements on the field penetration and field amplification are performed by a Hall probe on the dynamic ergodic divertor (DED) on the TEXTOR tokamak and the data are interpreted by a two-fluid plasma model. It is observed that the growth of the forced magnetic reconnection by the rotating DED field is accompanied by a change of the plasma fluid rotation. The differential rotation frequency between the DED field and the plasma plays an important role in the process of the excitation of tearing modes. The momentum input from the rotating DED field to the plasma is interpreted by both a ponderomotive force at the rational surface and a radial electric field modified by an edge ergodization. PMID:17026312

  15. Forced magnetic reconnection and field penetration of an externally applied rotating helical magnetic field in the TEXTOR tokamak

    Kikuchi, Y; de Bock, M. F. M.; Reiser, D.; Wolf, R C; Finken, K. H.; Jakubowski, M W.; R. Jaspers; Koslowski, H. R.; Krämer-Flecken, A; Lehnen, M.; Liang, Y.; Matsunaga, G.

    2006-01-01

    The magnetic field penetration process into a magnetized plasma is of basic interest both for plasma physics and astrophysics. In this context special measurements on the field penetration and field amplification are performed by a Hall probe on the dynamic ergodic divertor (DED) on the TEXTOR tokamak and the data are interpreted by a two-fluid plasma model. It is observed that the growth of the forced magnetic reconnection by the rotating DED field is accompanied by a change of the plasma fl...

  16. Influence of polymer additives on turbulent energy cascading in forced homogeneous isotropic turbulence studied by direct numerical simulations

    Direct numerical simulations (DNS) were performed for the forced homogeneous isotropic turbulence (FHIT) with/without polymer additives in order to elaborate the characteristics of the turbulent energy cascading influenced by drag-reducing effects. The finite elastic non-linear extensibility-Peterlin model (FENE-P) was used as the conformation tensor equation for the viscoelastic polymer solution. Detailed analyses of DNS data were carried out in this paper for the turbulence scaling law and the topological dynamics of FHIT as well as the important turbulent parameters, including turbulent kinetic energy spectra, enstrophy and strain, velocity structure function, small-scale intermittency, etc. A natural and straightforward definition for the drag reduction rate was also proposed for the drag-reducing FHIT based on the decrease degree of the turbulent kinetic energy. It was found that the turbulent energy cascading in the FHIT was greatly modified by the drag-reducing polymer additives. The enstrophy and the strain fields in the FHIT of the polymer solution were remarkably weakened as compared with their Newtonian counterparts. The small-scale vortices and the small-scale intermittency were all inhibited by the viscoelastic effects in the FHIT of the polymer solution. However, the scaling law in a fashion of extended self-similarity for the FHIT of the polymer solution, within the presently simulated range of Weissenberg numbers, had no distinct differences compared with that of the Newtonian fluid case

  17. Is functional hypertrophy and specific force coupled with the addition of myonuclei at the single muscle fiber level?

    Qaisar, R.; Renaud, G; Morine, K.; Barton, E. R.; Sweeney, H. L.; Larsson, L

    2012-01-01

    Muscle force is typically proportional to muscle size, resulting in constant force normalized to muscle fiber cross-sectional area (specific force). Mice overexpressing insulin-like growth factor-1 (IGF-1) exhibit a proportional gain in muscle force and size, but not the myostatin-deficient mice. In an attempt to explore the role of the cytoplasmic volume supported by individual myonuclei [myonuclear domain (MND) size] on functional capacity of skeletal muscle, we have investigated specific f...

  18. Hydrological response in the Danube lower basin to some internal and external forcing factors of the climate system

    Mares, Ileana; Dobrica, Venera; Demetrescu, Crisan; Mares, Constantin

    2016-04-01

    The precipitation in the Danube upper and middle basin is the main indicator for the Danube discharge at the entry in the lower basin. Along with precipitation, from the category of internal factors, in the first stage, we tried to find other predictors from the fields of temperature, pressure and geopotential. In the second phase, we considered external factors, taking into account the indices of solar/geomagnetic activity, represented by Wolf numbers, 10.7cm solar flux/aa geomagnetic index. In the Danube upper and middle basin, were considered fields of precipitation (PP), and temperatures (T) at 15 meteorological stations. The large-scale atmospheric circulation was quantified by Greenland-Balkan-Oscillation index (GBOI), North Atlantic Oscillation index and by blocking indices. The hydrological state in the Danube lower basin was represented by the discharge at the Orsova station. To estimate the discharge response in the Danube lower basin to various factors, developments in EOFs, cross correlations, power spectra, filters, composite maps were achieved. For the atmospheric variables, taken simultaneously, the most significant results (confidence level of 95%) are related to the predictors, considering the difference between standardized temperatures and precipitation (TPP), except for winter season, when the best predictors are PC1 of precipitation field and GBOI. In order to see the predictive hydrological response to the considered predictors, the correlative analyses with some lags were achieved. The significant results, were obtained for the winter/spring variables (PC1-precipitation and TPP), which can be considered good predictors for spring/summer discharge in the Danube lower basin. The hydrological response to the solar/ geomagnetic activity is given with a delay of two and three years. Due to the important signal of GBOI in the Danube basin precipitation in winter (correlation coefficient of 0.83), a stochastic modeling was performed between GBOI and

  19. Intrinsic stress, mismatch strain, and self-assembly during deposition of thin films subjected to an externally applied force

    A relation is derived between the mismatch strain, the film thickness, and the displacement of a linear elastic structure under external loading during material deposition. If any two of these variables can be experimentally determined, then the remaining variable can be determined. The method allows one to experimentally determine the mismatch strain by measuring the film thickness and the displacement of a point on the structure that is not undergoing deposition. The intrinsic stresses can be used to self-assemble microstructures during material deposition. Assembly of two components is considered: one component is subjected to deposition and is modeled as an Euler-Bernoulli beam, and the other component is not subjected to deposition and is modeled as a linear spring. For the purposes of this paper, the definition of assembly requires that the beam do work on the spring. The analysis is experimentally verified by electroplating nickel onto an AFM cantilever beam in contact with a second AFM beam (serving as the spring) that does not undergo deposition

  20. Deformable curve contours extraction under internal and external curvature forces%变形曲线曲率内外力作用下的轮廓提取

    张荣国; 刘焜; 党伟超; 刘小君

    2011-01-01

    文章对变形轮廓曲线的几何特征进行分析,提出了一种以曲率内外力为驱动力的主动轮廓边缘提取方法,对传统方法作了改进.首先经过比较,采用当前结点的八邻域点来计算变形曲线轮廓局部区域的曲率,并经过正则化处理,既保证了计算的精度要求,又降低了计算的复杂性,同时部分避免了后期的微分方程求解;根据进化轮廓的凹凸性以及它和目标轮廓的相对位置,对局部区域曲率力和梯度矢量场中的扩散力进行融合,获取进化所需外部力,实现主动轮廓和目标轮廓的有效拟合;最后通过人工合成图像和真实图像的比较,验证了该文方法的可行性和鲁棒性.%The geometric properties of a deformable curve are analyzed and a novel method of active contour boundary extraction is proposed based on the internal and external curvature forces. Two advancements have been gained by this method. Firstly, the local curvature of the deformable curve contour is calculated through eight adjacent points of current node and the result is normalized, which ensures the computing accuracy, reduces the processing complexity and avoids the difficulties in solving partial equation. Secondly, according to the concave-convex property of the evolutionary contour and its relative position to the objective contour, the external force for the evolution can be obtained by merging local curvature force with gradient vector flow force, which achieves the effective fitting between the objective contour and the active contour. The synthetic images are compared with the real ones, and the results illustrate that the proposed method is feasible and robust.

  1. CHARMM additive all-atom force field for carbohydrate derivatives and its utility in polysaccharide and carbohydrate-protein modeling

    Guvench, Olgun; Mallajosyula, Sairam S.; Raman, E. Prabhu; Hatcher, Elizabeth; Vanommeslaeghe, Kenno; Foster, Theresa J.; Jamison, Francis W.; MacKerell, Alexander D.

    2011-01-01

    Monosaccharide derivatives such as xylose, fucose, N-acetylglucosamine (GlcNAc), N-acetylgalactosamine (GlaNAc), glucuronic acid, iduronic acid, and N-acetylneuraminic acid (Neu5Ac) are important components of eukaryotic glycans. The present work details development of force-field parameters for these monosaccharides and their covalent connections to proteins via O-linkages to serine or threonine sidechains and via N-linkages to asparagine sidechains. The force field development protocol was ...

  2. The Impact of Spatial Externalities: Skills, Education and Firm Productivity

    Wixe, Sofia

    2013-01-01

    This paper analyses the role of spatial externalities in explaining the average labour productivity of Swedish manufacturing firms. The empirical findings support MAR and Porter externalities as well as general urbanization economies, but not Jacobs externalities. In addition, the matching between the firm and the regional labour force is found to be productivity-enhancing. However, firm-specific characteristics, including the characteristics of the employees, are not to be forgotten. Especia...

  3. Additional androgen deprivation makes the difference. Biochemical recurrence-free survival in prostate cancer patients after HDR brachytherapy and external beam radiotherapy

    Schiffmann, Jonas; Tennstedt, Pierre; Beyer, Burkhard; Boehm, Katharina; Tilki, Derya; Salomon, Georg; Graefen, Markus [University Medical Center Hamburg-Eppendorf, Martini-Clinic Prostate Cancer Center, Hamburg (Germany); Lesmana, Hans; Platz, Volker; Petersen, Cordula; Kruell, Andreas; Schwarz, Rudolf [University Medical Center Hamburg-Eppendorf, Department of Radiation oncology, Hamburg (Germany)

    2015-04-01

    The role of additional androgen deprivation therapy (ADT) in prostate cancer (PCa) patients treated with combined HDR brachytherapy (HDR-BT) and external beam radiotherapy (EBRT) is still unknown. Consecutive PCa patients classified as D'Amico intermediate and high-risk who underwent HDR-BT and EBRT treatment ± ADT at our institution between January 1999 and February 2009 were assessed. Multivariable Cox regression models predicting biochemical recurrence (BCR) were performed. BCR-free survival was assessed with Kaplan-Meier analyses. Overall, 392 patients were assessable. Of these, 221 (56.4 %) underwent trimodality (HDR-BT and EBRT and ADT) and 171 (43.6 %) bimodality (HDR-BT and EBRT) treatment. Additional ADT administration reduced the risk of BCR (HR: 0.4, 95 % CI: 0.3-0.7, p < 0.001). D'Amico high-risk patients had superior BCR-free survival when additional ADT was administered (log-rank p < 0.001). No significant difference for BCR-free survival was recorded when additional ADT was administered to D'Amico intermediate-risk patients (log-rank p = 0.2). Additional ADT administration improves biochemical control in D'Amico high-risk patients when HDR-BT and EBRT are combined. Physicians should consider the oncological benefit of ADT administration for these patients during the decision-making process. (orig.) [German] Der Nutzen einer zusaetzlichen Hormonentzugstherapie (ADT, ''androgen deprivation therapy'') fuer Patienten mit Prostatakarzinom (PCa), welche mit einer Kombination aus HDR-Brachytherapie (HDR-BT) und perkutaner Bestrahlung (EBRT) behandelt werden, ist weiterhin ungeklaert. Fuer diese Studie wurden konsekutive, nach der D'Amico-Risikoklassifizierung in ''intermediate'' und ''high-risk'' eingeteilte Patienten ausgewaehlt, die zwischen Januar 1999 und Februar 2009 in unserem Institut eine kombinierte Therapie aus HDR-BT, EBRT ± ADT erhalten haben. Eine

  4. Effects of Bi-2212 addition on the levitation force properties of bulk MgB{sub 2} superconductors

    Taylan Koparan, E. [Bulent Ecevit University, Department of Science Education, Eregli Faculty of Education, Zonguldak (Turkey); Savaskan, B. [Karadeniz Technical University, Energy Systems Engineering, Faculty of Technology, Trabzon (Turkey); Guner, S.B. [Recep Tayyip Erdogan University, Department of Physics, Faculty of Arts and Sciences, Rize (Turkey); Celik, S. [Sinop University, Energy Systems Engineering, Faculty of Engineering and Architecture, Sinop (Turkey)

    2016-02-15

    We present a detailed investigation of the effects of Bi{sub 2}Sr{sub 2}Ca{sub 1}Cu{sub 2}O{sub 8+κ} (Bi-2212) adding on the levitation force and magnetic properties of bulk MgB{sub 2} obtained by hot press method. The amount of Bi-2212 was varied between 0 and 10 wt% (0, 2, 4, 6, 10 wt%) of the total MgB{sub 2}. Moreover, we present MgB{sub 2} bulk samples fabricated by using different production methods including hot pressing method to our knowledge. All samples were prepared by using elemental magnesium (Mg) powder, amorphous nano-boron (B) powder and Bi-2212 powder which are produced by hot press method. As a result of hot press process, compact pellet samples were manufactured. The vertical and lateral levitation force measurements were executed at the temperatures of 20, 24 and 28 K under zero-field-cooled (ZFC) and field-cooled (FC) regimes for samples with various adding levels. At 24 K and 28 K under ZFC regime, the 2 wt% Bi-2212 added sample exhibits a higher vertical levitation force than the pure sample. Bi-2212 added MgB{sub 2} samples compared to the pure sample have lower attractive force values in FC regime. The magnetic field dependence of the critical current density J{sub c} was calculated from the M-H loops for Bi-2212 added MgB{sub 2} samples. The 2 wt% Bi-2212 added sample has the best levitation and critical current density performance compared to other samples. The critical temperature (T{sub c}) has slightly dropped from 37.8 K for the pure MgB{sub 2} sample to 36.7 K for the 10 wt% of Bi-2212 added sample. The transition temperature slightly decreases when Bi-2212 adding level is increased. (orig.)

  5. Effects of Bi-2212 addition on the levitation force properties of bulk MgB2 superconductors

    Taylan Koparan, E.; Savaskan, B.; Guner, S. B.; Celik, S.

    2016-02-01

    We present a detailed investigation of the effects of Bi2Sr2Ca1Cu2O8+κ (Bi-2212) adding on the levitation force and magnetic properties of bulk MgB2 obtained by hot press method. The amount of Bi-2212 was varied between 0 and 10 wt% (0, 2, 4, 6, 10 wt%) of the total MgB2. Moreover, we present MgB2 bulk samples fabricated by using different production methods including hot pressing method to our knowledge. All samples were prepared by using elemental magnesium (Mg) powder, amorphous nano-boron (B) powder and Bi-2212 powder which are produced by hot press method. As a result of hot press process, compact pellet samples were manufactured. The vertical and lateral levitation force measurements were executed at the temperatures of 20, 24 and 28 K under zero-field-cooled (ZFC) and field-cooled (FC) regimes for samples with various adding levels. At 24 K and 28 K under ZFC regime, the 2 wt% Bi-2212 added sample exhibits a higher vertical levitation force than the pure sample. Bi-2212 added MgB2 samples compared to the pure sample have lower attractive force values in FC regime. The magnetic field dependence of the critical current density J c was calculated from the M-H loops for Bi-2212 added MgB2 samples. The 2 wt% Bi-2212 added sample has the best levitation and critical current density performance compared to other samples. The critical temperature ( T c ) has slightly dropped from 37.8 K for the pure MgB2 sample to 36.7 K for the 10 wt% of Bi-2212 added sample. The transition temperature slightly decreases when Bi-2212 adding level is increased.

  6. Effects of Bi-2212 addition on the levitation force properties of bulk MgB2 superconductors

    We present a detailed investigation of the effects of Bi2Sr2Ca1Cu2O8+κ (Bi-2212) adding on the levitation force and magnetic properties of bulk MgB2 obtained by hot press method. The amount of Bi-2212 was varied between 0 and 10 wt% (0, 2, 4, 6, 10 wt%) of the total MgB2. Moreover, we present MgB2 bulk samples fabricated by using different production methods including hot pressing method to our knowledge. All samples were prepared by using elemental magnesium (Mg) powder, amorphous nano-boron (B) powder and Bi-2212 powder which are produced by hot press method. As a result of hot press process, compact pellet samples were manufactured. The vertical and lateral levitation force measurements were executed at the temperatures of 20, 24 and 28 K under zero-field-cooled (ZFC) and field-cooled (FC) regimes for samples with various adding levels. At 24 K and 28 K under ZFC regime, the 2 wt% Bi-2212 added sample exhibits a higher vertical levitation force than the pure sample. Bi-2212 added MgB2 samples compared to the pure sample have lower attractive force values in FC regime. The magnetic field dependence of the critical current density Jc was calculated from the M-H loops for Bi-2212 added MgB2 samples. The 2 wt% Bi-2212 added sample has the best levitation and critical current density performance compared to other samples. The critical temperature (Tc) has slightly dropped from 37.8 K for the pure MgB2 sample to 36.7 K for the 10 wt% of Bi-2212 added sample. The transition temperature slightly decreases when Bi-2212 adding level is increased. (orig.)

  7. Exploring the retention properties of CaF2 nanoparticles as possible additives for dental care application with tapping-mode atomic force microscope in liquid

    Matthias Wasem; Joachim Köser; Sylvia Hess; Enrico Gnecco; Ernst Meyer

    2014-01-01

    Amplitude-modulation atomic force microscopy (AM-AFM) is used to determine the retention properties of CaF2 nanoparticles adsorbed on mica and on tooth enamel in liquid. From the phase-lag of the forced cantilever oscillation the local energy dissipation at the detachment point of the nanoparticle was determined. This enabled us to compare different as-synthesized CaF2 nanoparticles that vary in shape, size and surface structure. CaF2 nanoparticles are candidates for additives in dental care ...

  8. Exploring the retention properties of CaF2 nanoparticles as possible additives for dental care application with tapping-mode atomic force microscope in liquid

    Wasem, Matthias; Köser, Joachim; Hess, Sylvia; Gnecco, Enrico; Meyer, Ernst

    2014-01-01

    Amplitude-modulation atomic force microscopy (AM-AFM) is used to determine the retention properties of CaF2 nanoparticles adsorbed on mica and on tooth enamel in liquid. From the phase-lag of the forced cantilever oscillation the local energy dissipation at the detachment point of the nanoparticle was determined. This enabled us to compare different as-synthesized CaF2 nanoparticles that vary in shape, size and surface structure. CaF2 nanoparticles are candidates for additives in dental care ...

  9. Evaluating External Communication.

    DeSantis, James R.

    1978-01-01

    Effective external communication by higher education institutions is described as an ongoing program, based on objective research, continuous informal feedback, and informed anticipation of changes in the environment that will force changes in the institution. (JMF)

  10. 政府和社会力量参与高校治理问题研究——基于“外部利益相关者”视角%A Study of Participation in University Governance of the Government and Social Forces --- from the Perspective of External Stakeholders

    吴安新; 邓江凌

    2012-01-01

    政府和社会力量作为高校的外部利益相关者,对高校治理有着越来越重要的影响。为了让政府和各种社会力量充分参与高校治理,形成“政府一高校一社会”多元共治的格局,应实现高校治理由管理型向服务型转变,建立高校与外部利益相关者的沟通交流机制,健全外部利益相关者的参与规则,同时社会力量也要转变认识,增强参与意识,加强自身建设。%As the external stakeholders of universities, the government and social forces have great influence on university governance.In order to enable the government and social forces to participate fully in the university governance and form this kind of pattern "Government- Universities- Society' Joint Governance" ,we should realize the transformation from governance model to service model,set up communication and exchange mechanism between universities and external stakeholders and improve the participation rules of external stakeholders.In addition, social forces should also change understanding,enhance the awareness of participation and strengthen self construction.

  11. Flood sensitivity of the Bavarian Alpine Foreland since the late Middle Ages in the context of internal and external climate forcing factors

    Böhm, O.; Jacobeit, J.; Glaser, R.; Wetzel, K.-F.

    2015-12-01

    This paper describes the flood sensitivity of the Bavarian part of the Alpine Foreland of Germany and addresses different questions concerning climate variability and flood frequencies, from the 14th century until today. The focal point of the paper is the flood frequency of the superordinate spatial unit of the Bavarian Foreland. Based on written historical sources, the flood history of the Alpine Foreland of Germany can be reconstructed back to the 14th century. One major result is the occurrence of "flood-rich" and "flood-poor" episodes in almost cyclical sequences. Flood-rich periods, before the 16th century based on limited available data, were recorded in the periods 1300-1335, 1370-1450, 1470-1525, 1555-1590, 1615-1665, 1730-1780, 1820-1870, and 1910-1955 as well as in a ninth period beginning in 1980. The flood-rich periods are characterized by longer flood duration. Most of the flood-rich and flood-poor periods (in particular the beginning and the end of them) can be connected to changes in natural climate variability. These include changing sunspot numbers (as a measure of solar activity), so-called Little Ice Age type events (LIATEs) as well as changes in the North Atlantic Oscillation (NAO). Climate signals from external forcing factors, which could be used to explain the changing flood frequencies in the Bavarian Alpine Foreland, end in 1930. Relationships within the climate system such as the correlation of flood frequencies with the NAO have changed during the transition from the post Little Ice Age period to the Modern Climate Optimum around 1930. Natural climate variability might have been overlaid by anthropogenic climate change.

  12. The main features of seasonal variability in the external forcing and dynamics of a deep mountain lake (Redó, Pyrenees

    David M. LIVINGSTONE

    2000-09-01

    Full Text Available Lake Redó, a dimictic oligotrophic mountain lake, was monitored for two complete years from July 1996 to July 1998. The main seasonal variations in the physical, chemical and biological parameters are described, with special emphasis on the comparison of external forcing (weather and atmospheric deposition with internal lake dynamics. Annual mean air temperature was estimated to be 3.6 °C. The duration of ice cover on the lake was 4.5 months in 1996/97 and 5.8 months in 1997/98. The lake water was very ionpoor (mean annual conductivity 12 μS cm-1; however, ion concentrations in the lake were higher than in the precipitation, the differences being due mainly to Ca2+ and bicarbonates originating in the catchment. NH4 + was the main ion in the precipitation, with an average concentration of 17 μM, while in the lake it was always below 3 μM. However, the concentration of dissolved inorganic nitrogen always exceeded that of soluble reactive phosphorus by two or three orders of magnitude, so the latter is likely to be the limiting nutrient for phytoplankton growth. Four main production episodes were identified, occurring during spring and autumn overturn, in the upper hypolimnion during summer stratification, and under the ice at the beginning of the ice-covered period. The highest chlorophyll-a concentrations (1.2-2.2 μg l-1 were attained during spring overturn; concentrations of chlorophyll-c were high during both spring and autumn overturn, while chlorophyll-b was comparatively important in the upper hypolimnion during the stratification period. Daphnia pulicaria was the most abundant macrozooplankton species; its abundance was highest during the icecovered period, when its biomass was comparable to the measured sestonic particulate carbon concentration. The Daphnia maximum was associated with higher concentrations of NH4 + and dissolved organic carbon, suggesting that it may play an important role in the pelagic biogeochemical compartment of

  13. Exploring the retention properties of CaF2 nanoparticles as possible additives for dental care application with tapping-mode atomic force microscope in liquid

    Matthias Wasem

    2014-01-01

    Full Text Available Amplitude-modulation atomic force microscopy (AM-AFM is used to determine the retention properties of CaF2 nanoparticles adsorbed on mica and on tooth enamel in liquid. From the phase-lag of the forced cantilever oscillation the local energy dissipation at the detachment point of the nanoparticle was determined. This enabled us to compare different as-synthesized CaF2 nanoparticles that vary in shape, size and surface structure. CaF2 nanoparticles are candidates for additives in dental care products as they could serve as fluorine-releasing containers preventing caries during a cariogenic acid attack on the teeth. We show that the adherence of the nanoparticles is increased on the enamel substrate compared to mica, independently of the substrate roughness, morphology and size of the particles.

  14. External and Internal Influences as Driving Forces and/or Stumbling-Blocks in the Development of the South African Quality Assurance System Nationally as Well as Institutionally.

    van der Westhuizen, L. J.

    2002-01-01

    Examines the most important internal and external environmental influences directing or hampering national and institutional quality assurance and management developments, as well as their implementation, in the South African higher education system. (EV)

  15. STABILITY OF MANIPULATOR CONFIGURATION UNDER EXTERNAL LOADING

    Klimchik, Alexandr; Pashkevich, Anatol; Chablat, Damien

    2012-01-01

    The paper is devoted to the analysis of robotic manipulator behavior under internal and external loadings. The main contributions are in the area of stability analysis of manipulator configurations corresponding to the loaded static equilibrium. In contrast to other works, in addition to usually studied the end-platform behavior with respect to the disturbance forces, the problem of configuration stability for each kinematic chain is considered. The proposed approach extends the classical not...

  16. Kirkwood-Buff analysis of aqueous N-methylacetamide and acetamide solutions modeled by the CHARMM additive and Drude polarizable force fields.

    Lin, Bin; Lopes, Pedro E M; Roux, Benoît; MacKerell, Alexander D

    2013-08-28

    Kirkwood-Buff analysis was performed on aqueous solutions of N-methylacetamide and acetamide using the Chemistry at HARvard Molecular Mechanics additive and Drude polarizable all-atom force fields. Comparison of a range of properties with experimental results, including Kirkwood-Buff integrals, excess coordination numbers, solution densities, partial molar values, molar enthalpy of mixing, showed both models to be well behaved at higher solute concentrations with the Drude model showing systematic improvement at lower solution concentrations. However, both models showed difficulties reproducing experimental activity derivatives and the excess Gibbs energy, with the Drude model performing slightly better. At the molecular level, the improved agreement of the Drude model at low solute concentrations is due to increased structure in the solute-solute and solute-solvent interactions. The present results indicate that the explicit inclusion of electronic polarization leads to improved modeling of dilute solutions even when those properties are not included as target data during force field optimization. PMID:24007020

  17. Protocol Additional to the agreement between the Republic of Armenia and the International Atomic Energy Agency for the application of safeguards in connection with the Treaty on the Non-Proliferation of Nuclear Weapons. Entry into force

    Pursuant to Article 17 of the Protocol Additional to the Agreement between the Republic of Armenia and the International Atomic Energy Agency for the Application of Safeguards in Connection with the Treaty on the Non-Proliferation of Nuclear Weapons, the Additional Protocol entered into force on 28 June 2004, the date on which the Agency received from Armenia written notification that Armenia's statutory and/or constitutional requirements for entry into force had been met

  18. Families of Fokker-Planck equations and the associated entropic form for a distinct steady-state probability distribution with a known external force field.

    Asgarani, Somayeh

    2015-02-01

    A method of finding entropic form for a given stationary probability distribution and specified potential field is discussed, using the steady-state Fokker-Planck equation. As examples, starting with the Boltzmann and Tsallis distribution and knowing the force field, we obtain the Boltzmann-Gibbs and Tsallis entropies. Also, the associated entropy for the gamma probability distribution is found, which seems to be in the form of the gamma function. Moreover, the related Fokker-Planck equations are given for the Boltzmann, Tsallis, and gamma probability distributions. PMID:25768455

  19. Biogeochemistry and ecosystems of continental margins in the western North Pacific Ocean and their interactions and responses to external forcing - an overview and synthesis

    Liu, K.-K.; Kang, C.-K.; Kobari, T.; Liu, H.; Rabouille, C.; Fennel, K.

    2014-12-01

    In this special issue we examine the biogeochemical conditions and marine ecosystems in the major marginal seas of the western North Pacific Ocean, namely, the East China Sea, the Japan/East Sea to its north and the South China Sea to its south. They are all subject to strong climate forcing as well as anthropogenic impacts. On the one hand, continental margins in this region are bordered by the world's most densely populated coastal communities and receive tremendous amount of land-derived materials. On the other hand, the Kuroshio, the strong western boundary current of the North Pacific Ocean, which is modulated by climate oscillation, exerts strong influences over all three marginal seas. Because these continental margins sustain arguably some of the most productive marine ecosystems in the world, changes in these stressed ecosystems may threaten the livelihood of a large population of humans. This special issue reports the latest observations of the biogeochemical conditions and ecosystem functions in the three marginal seas. The studies exemplify the many faceted ecosystem functions and biogeochemical expressions, but they reveal only a few long-term trends mainly due to lack of sufficiently long records of well-designed observations. It is critical to develop and sustain time series observations in order to detect biogeochemical changes and ecosystem responses in continental margins and to attribute the causes for better management of the environment and resources in these marginal seas.

  20. Protocol Additional to the Agreement between the Republic of Iraq and the International Atomic Energy Agency for the Application of Safeguards in Connection with the Treaty on the Non-Proliferation of Nuclear Weapons. Entry into Force

    Pursuant to Article 17 of the Protocol Additional to the Agreement between the Republic of Iraq and the International Atomic Energy Agency for the Application of Safeguards in Connection with the Treaty on the Non-Proliferation of Nuclear Weapons (the Additional Protocol), the Additional Protocol, which had been applied provisionally from 17 February 2010, entered into force on 10 October 2012, the date upon which the Agency received written notification from Iraq that Iraq's statutory and/or constitutional requirements for entry into force had been met

  1. External costs of electric power generation systems. Nuclear fuel cycle in ExternE

    In ExternE, external costs on mine steps such as mining and refining of uranium, conversion, enrichment, fuel production, power generation, reprocessing, wastes treatment, transportation, and construction and subdivision were evaluated. However, even treatment of same a step is not always carried out in own country. In order to conduct a fair evaluation, every country must elucidate performances of its specified sites. And, ExternE defines some important evaluation items (priority Impact) thought to largely affect the external cost formed at every stage in each power generation system. In addition, ExternE also considers on some impact routes of radioactive materials. On calculation result of external costs on the nuclear power generation, as its methodology is common, its evaluation results are not always realistic because of use of French data using Phase II when insufficiency of data in own country, use of supposed site condition, use of different time span for evaluating effect, and so forth. (G.K.)

  2. Dispersion Forces

    Buhmann, Stefan Yoshi

    2012-01-01

    In this book, a modern unified theory of dispersion forces on atoms and bodies is presented which covers a broad range of advanced aspects and scenarios. Macroscopic quantum electrodynamics is shown to provide a powerful framework for dispersion forces which allows for discussing general properties like their non-additivity and the relation between microscopic and macroscopic interactions. It is demonstrated how the general results can be used to obtain dispersion forces on atoms in the presence of bodies of various shapes and materials. Starting with a brief recapitulation of volume I, this volume II deals especially with bodies of irregular shapes, universal scaling laws, dynamical forces on excited atoms, enhanced forces in cavity quantum electrodynamics, non-equilibrium forces in thermal environments and quantum friction. The book gives both the specialist and those new to the field a thorough overview over recent results in the field. It provides a toolbox for studying dispersion forces in various contex...

  3. The swim force as a body force

    Yan, Wen; Brady, John

    2015-11-01

    Net (as opposed to random) motion of active matter results from an average swim (or propulsive) force. It is shown that the average swim force acts like a body force - an internal body force [Yan and Brady, Soft Matter, DOI:10.1039/C5SM01318F]. As a result, the particle-pressure exerted on a container wall is the sum of the swim pressure [Takatori et al., Phys. Rev. Lett., 2014, 113, 028103] and the `weight' of the active particles. A continuum mechanical description is possible when variations occur on scales larger than the run length of the active particles and gives a Boltzmann-like distribution from a balance of the swim force and the swim pressure. Active particles may also display `action at a distance' and accumulate adjacent to (or be depleted from) a boundary without any external forces. In the momentum balance for the suspension - the mixture of active particles plus fluid - only external body forces appear.

  4. 厚风积砂覆盖地层立井井壁竖直附加力与井壁结构%Vertical additional force and structure of shaft lining in thick aeolian sand strata

    张驰; 杨志江; 张涛; 韩涛

    2016-01-01

    Through physical experiment and numerical calculation, the vertical shear test between sat-urated sand and shaft concrete interface was preliminarily studied, and some interface shear strength parameters were obtained. The variation of vertical additional force on shaft lining in thick aeolian sand strata was further studied through numerical calculation. Research results have shown that 1) The verti-cal additional force presents nonlinear growth rule as the depth in aeolian sand strata increases, and the maximum vertical additional force appears near the interface between aeolian sand and bedrock; and 2) After entering the bedrock, vertical additional force rapidly decreases because of bedrock force-sharing effect. In more than 100 meters depth of aeolian sand, as water level of aeolian sand aquifer declines (such as decline more than 20 meters), traditional double layer shaft lining can be ruptured near the in-terface between aeolian sand and bedrock under the action of vertical additional force. Therefore, the compressible shaft lining structure should be adopted to limit the increase of vertical additional force in thick aeolian sand strata.%采用物理试验方法,初步开展饱和砂与井壁混凝土界面竖向剪切试验,获得了界面竖向抗剪强度指标;基于数值计算,进一步研究厚风积砂覆盖地层立井井壁竖直附加力的变化规律。结果表明:风积砂地层中,井壁竖直附加力随深度的增加呈现出非线性增长规律,并在风积砂含水层与基岩交界面附近达到极值;进入基岩段后,竖直附加力部分由基岩分担,附加力急剧减小。在厚度超过100 m 的风积砂地层中,随着含水层水位的不断下降(如超过20 m),传统的双层复合井壁结构在竖直附加力等作用下,于基岩交界面附近可能出现井壁破裂灾害,应采用适应地层沉降的可缩井壁结构限制竖直附加力的增长。

  5. Externalities of fuel cycles 'ExternE' project. Summary report

    There is a growing requirement for policy analysts to take account of the environment in their decision making and to undertake the specified cost-benefit analysis. Within the European Union this is reflected in the 5th Environmental Action Programme, and the Commission's White Paper entitled 'Growth, competitiveness, employment and the ways forward to the 21st century'. This has led to a need for evaluation of environmental externalities. The ExternE Project commenced in 1991 as the European part of a collaborative study between the European Commission and the US Department of Energy. It aims to be the first systematic approach to the evaluation of external costs of a wide range of different fuel cycles. The project will result in an operational accounting framework for the quantification and monetarisation of priority environmental and other externalities. This framework will allow the calculation of the marginal external costs and benefits for specific power plants, at specific sites using specified technologies. There are three major phases in the project. Phase I was undertaken in collaboration with the US Department of Energy. In this phase the teams jointly developed the conceptual approach and methodology and shared scientific information for application to a number of fuel cycles. On the European side work concentrated on the nuclear and coal fuel cycles which together were expected to raise many of the fundamental issues in fuel cycle analysis. The project is currently nearing completion of Phase 2. During this phase the methodology has been applied to a wide range of different fossil, nuclear and renewable fuel cycles for power generation and energy conservation options. Also a series of National Implementation Programmes are underway in which the methodology and accounting framework are being applied to reference sites throughout Europe. In addition the general methodology is being extended to address the evaluation of externalities associated with

  6. ExternE: Externalities of energy Vol. 1. Summary

    There is a growing requirement for policy analysts to take account of the environment in their decision making and to undertake the specified cost-benefit analysis. Within the European Union this is reflected in the 5th Environmental Action Programme, and the Commission's White Paper entitled 'Growth, competitiveness, employment and the ways forward to the 21st century'. This has led to a need for evaluation of environmental externalities. The ExternE Project commenced in 1991 as the European part of a collaborative study between the European Commission and the US Department of Energy. It aims to be the first systematic approach to the evaluation of external costs of a wide range of different fuel cycles. The project will result in an operational accounting framework for the quantification and monetarisation of priority environmental and other externalities. This framework will allow the calculation of the marginal external costs and benefits for specific power plants, at specific sites using specified technologies. There are three major phases in the project. Phase 1 was undertaken in collaboration with the US Department of Energy. In this phase the teams jointly developed the conceptual approach and methodology and shared scientific information for application to a number of fuel cycles. On the European side work concentrated on the nuclear and coal fuel cycles which together were expected to raise many of the fundamental issues in fuel cycle analysis. The project is currently nearing completion of Phase 2. During this phase the methodology has been applied to a wide range of different fossil, nuclear and renewable fuel cycles for power generation and energy conservation options. Also a series of National Implementation Programmes is underway in which the methodology and accounting framework are being applied to reference sites throughout Europe. In addition the general methodology is being extended to address the evaluation of externalities associated with

  7. Force-chain identification in quasi-2D granular systems

    Zhang, Ling; Wu, Jun-Qi; Zhang, Jie

    2013-06-01

    Understanding the properties of force-chains is essential in understanding the physical and mechanical properties of granular materials. The key is to identify force-chains. In this study, we describe a systematic method to identify individual force-chains in 2D granular systems under different external load-pure shear or isotropic compression, where bi-disperse photo-elastic particles were used in order to measure vector contact forces between particles. Using this method, we studied the statistics of force-chain size distribution in these two systems: in pure shear, the distribution shows a fat tail that deviates from an exponential distribution function, whereas in isotropic compression, the distribution decays exponentially. In addition, we also investigated the dependence of various force-chain statistics on two main parameters defined in the force-chain identification algorithm.

  8. External Beam Therapy (EBT)

    ... Physician Resources Professions Site Index A-Z External Beam Therapy (EBT) External beam therapy (EBT) is a ... follow-up should I expect? What is external beam therapy and how is it used? External beam ...

  9. Does the experience level of the radiologist, assessment in consensus, or the addition of the abduction and external rotation view improve the diagnostic reproducibility and accuracy of MRA of the shoulder?

    Aim: To prospectively evaluate the influence of observer experience, consensus assessment, and abduction and external rotation (ABER) view on the diagnostic performance of magnetic resonance arthrography (MRA) in patients with traumatic anterior-shoulder instability (TASI). Materials and methods: Fifty-eight MRA examinations (of which 51 had additional ABER views) were assessed by six radiologists (R1–R6) and three teams (T1–T3) with different experience levels, using a seven-lesion standardized scoring form. Forty-five out of 58 MRA examination findings were surgically confirmed. Kappa coefficients, sensitivity, specificity, and differences in percent agreement or correct diagnosis (p-value, McNemar's test) were calculated per lesion and overall per seven lesion types to assess diagnostic reproducibility and accuracy. Results: Overall kappa ranged from poor (k = 0.17) to moderate (k = 0.53), sensitivity from 30.6–63.5%, and specificity from 73.6–89.9%. Overall, the most experienced radiologists (R1–R2) and teams (T2–T3) agreed significantly more than the lesser experienced radiologists (R3–R4: p = 0.014, R5–R6; p = 0.018) and teams (T2–T3: p = 0.007). The most experienced radiologist (R1, R2, R3) and teams (T1, T2) were also consistently more accurate than the lesser experienced radiologists (R4, R5, R6) and team (T3). Significant differences were found between R1–R4 (p = 0.012), R3–R4 (p = 0.03), and T2–T3 (p = 0.014). The overall performance of consensus assessment was systematically higher than individual assessment. Significant differences were established between T1–T2 and radiologists R3–R4 (p<0.001, p = 0.001) and between T2 and R3 (p<0.001/p = 0.001) or R4 (p = 0.050). No overall significant differences were found between the radiologists' assessments with and without ABER. Conclusion: The addition of ABER does not significantly improve overall diagnostic performance. The radiologist

  10. ExternE: Externalities of energy Vol. 5. Nuclear

    Since the early 1970s, there has been increased interest in the environmental impacts that are caused by the generation of electricity. The comparative risk assessment studies at that time used mainly deaths and injuries as impact indicators. By the end of the 1980s studies changed to the assessment of the costs imposed on society and the environment that were not included in the market price of the energy produced, the so-called external costs. The preliminary studies that were published set the conceptual basis, grounded in neo-classical economics, for the valuation of the health and environmental impacts that could be assessed. As a consequence of the many questions raised by the methodologies employed by these early studies, Directorate General XII (DG XII) of the Commission of the European Communities established a collaborative research programme with the United States Department of Energy to identify an appropriate methodology for this type of work. Following the completion of this collaboration, the DG XII programme has continued as the ExternE project. The main objective of the work carried out at CEPN was to develop an impact pathway methodology for the nuclear fuel cycle that would be consistent with the methodologies developed for other fuel cycles, without loosing the nuclear-specific techniques required for a proper evaluation. In this way, comparisons between the different fuel cycles would be possible. This report presents the methodology and demonstration of the results in the context of the French nuclear fuel cycle. The United States team at Oak Ridge National Laboratory has previously issued a draft report on the results of their assessment. The French fuel cycle was broken down into 8 separate stages. Reference sites and 1990s technology were chosen to represent the total nuclear fuel cycle, as it exists today. In addition, the transportation of material between the sites was considered. The facilities are assessed for routine operation, except

  11. Magnetic nanoparticle motion in external magnetic field

    A set of equations describing the motion of a free magnetic nanoparticle in an external magnetic field in a vacuum, or in a medium with negligibly small friction forces is postulated. The conservation of the total particle momentum, i.e. the sum of the mechanical and the total spin momentum of the nanoparticle is taken into account explicitly. It is shown that for the motion of a nanoparticle in uniform magnetic field there are three different modes of precession of the unit magnetization vector and the director that is parallel the particle easy anisotropy axis. These modes differ significantly in the precession frequency. For the high-frequency mode the director points approximately along the external magnetic field, whereas the frequency and the characteristic relaxation time of the precession of the unit magnetization vector are close to the corresponding values for conventional ferromagnetic resonance. On the other hand, for the low-frequency modes the unit magnetization vector and the director are nearly parallel and rotate in unison around the external magnetic field. The characteristic relaxation time for the low-frequency modes is remarkably long. This means that in a rare assembly of magnetic nanoparticles there is a possibility of additional resonant absorption of the energy of alternating magnetic field at a frequency that is much smaller compared to conventional ferromagnetic resonance frequency. The scattering of a beam of magnetic nanoparticles in a vacuum in a non-uniform external magnetic field is also considered taking into account the precession of the unit magnetization vector and director. - Highlights: • There are three different modes of the unit magnetization vector precession for a free magnetic nanoparticle in uniform external magnetic field. • The high-frequency mode is similar to the conventional ferromagnetic resonance. The frequencies of the low-frequency modes can be two orders of magnitude lower. • The characteristic relaxation

  12. The ExternE project: methodology, objectives and limitations

    This paper presents a summary of recent studies on external costs of energy systems, in particular the ExternE (External Costs of Energy) Project of the European Commission. To evaluate the impact and damage cost of a pollutant, one needs to carry out an impact pathway analysis; this involves the calculation of increased pollutant concentrations in all affected regions due to an incremental emission (e.g. μg/m3 of particles, using models of atmospheric dispersion and chemistry), followed by the calculation of physical impacts (e.g. number of cases of asthma due to these particles, using a dose-response function). The entire so-called fuel chain (or fuel cycle) is evaluated and compared on the basis of delivered end use energy. Even though the uncertainties are large, the results provide substantial evidence that the classical air pollutants (particles, NOx and SOx) from the combustion of fossil fuels impose a heavy toll, in addition to the cost of global warming. The external costs are especially large for coal; even for 'good current technology' they may be comparable to the price of electricity. For natural gas the external costs are about a third to a half of coal. The external costs of nuclear are small compared to the price of electricity (at most a few %), and so are the external costs of most renewable energy systems. (authors)

  13. Surface and Interfacial Forces

    Butt, Hans-Jurgen

    2010-01-01

    This systematic introduction to the topic includes theoretical concepts to help readers understand and predict surface forces, while also integrating experimental techniques and practical applications with up-to-date examples plus motivating exercises. Starting with intermolecular forces, the authors discuss different surfaces forces, with a major part devoted to surface forces between solid surfaces in liquid media. In addition, they cover surface forces between liquid-vapor interfaces and between liquid-liquid interfaces.

  14. Particle separation by external fields on periodic surfaces

    Particles moving on perfect periodic surfaces under the influence of external forces may move along directions that deviate from that of the force. We briefly recall previous results for transport of particles on surfaces with periodic traps or periodic obstacles driven by a constant external force, and present new results for particles moving in a harmonic periodic potential. The sorting properties are explored as a function of a number of control parameters, specifically the friction, force amplitude and direction, temperature, and lattice constants

  15. Nonlinear Dynamic Force Spectroscopy

    Björnham, Oscar

    2016-01-01

    Dynamic force spectroscopy (DFS) is an experimental technique that is commonly used to assess information of the strength, energy landscape, and lifetime of noncovalent bio-molecular interactions. DFS traditionally requires an applied force that increases linearly with time so that the bio-complex under investigation is exposed to a constant loading rate. However, tethers or polymers can modulate the applied force in a nonlinear regime. For example, bacterial adhesion pili and polymers with worm-like chain properties are examples of structures that show nonlinear force responses. In these situations, the theory for traditional DFS cannot be readily applied. In this work we expand the theory for DFS to also include nonlinear external forces while still maintaining compatibility with the linear DFS theory. To validate the theory we modeled a bio-complex expressed on a stiff, an elastic and a worm-like chain polymer, using Monte Carlo methods, and assessed the corresponding rupture force spectra. It was found th...

  16. Automatic optimization of doses in external radiotherapy. Adaptation to a small informatics system. Addition of programmes for the determination of iso-effect curves and the computing of irradiation times

    The problem of computerized dose optimization in external radiotherapy was studied. An optimization by linear programming was developed, giving as homogeneous as possible a dose distribution in the target volume though without exceeding certain doses outside the tumour. By a set of modular programmes written in Fortran it is possible to optimize doses, plot iso-effect curves and compute irradiation time per beam and per session. This thesis is divided into two main sections. - Part one reviews the optimization criteria, describes the different mathematical methods and points out the originality of the method in the choice of object function. Finally the choices made for the informatics system used and the programmes established are presented. - Part two deals with the other programmes developed. The NSD and TDF formulae, from which the biological effect is calculated and the iso-effect curves are determined, are recalled. The irradiation time calculation depends on many parameters and especially the activity decay for cobalt sources. These elements are specified in the text and accounted for by different programmes. All the programmes described are now operational and are illustrated by examples. The programmes are conversational and have been made as simple as possible to use

  17. Crossflow force transducer

    A force transducer for measuring lift and drag coefficients for a circular cylinder in turbulent water flow is presented. In addition to describing the actual design and construction of the strain-gauged force- ring based transducer, requirements for obtained valid fluid force test data are discussed, and pertinent flow test experience is related

  18. An external drag measuring element

    Ringel, Mordechai; Levin, Daniel; Seginer, Arnan

    The accurate measurement of the axial-force component acting on small wind-tunnel models has traditionally made use of integral string balances, which eliminated many accuracy problems, such as friction and hysteresis, but also introduced interactions between the various force and moment sensing elements due to nonlinear elastic phenomena. The reduction of these interactions usually calls for complicated designs, expensive manufacturing, hard-to-handle calibration processes, and cumbersome data reduction programs. An approach is presented that is based on an external axial-force-measuring element and avoids the ill-conditioned design problems of integral balances. Other difficulties that are encountered, such as friction, misalignment, and relative motion between metric elements are considered, and their solution is examined. Calibration and test results show that the new approach duplicates and surpasses the results of much more complicated and expensive integral balances.

  19. Enhancement of wave and acceleration of electron in plasma in the external field

    2008-01-01

    This paper investigates the enhancement of Langmuir and ion-acoustic wave and the acceleration of the electron in collisionless plasma.in the presence of an external transverse field.Based on hydrodynamic equations,an equation formulizing the parametric instability was derived.Furthermore,the formula for ponderomotive force and the expression that describes the electron acceleration were obtained.The results show that Langmuir and ion-acoustic wave are enhanced and the charged particles can be accelerated by the coupling of wave-wave.In addition,it can be concluded that ponderomotive force,due to the coupling of the external field(pump)to the Langmuir wave(ion-acoustic wave),is the driving force to excite the parametric instability and comprises the high- and low-frequency components.

  20. Acoustic interaction forces between small particles in an ideal fluid

    Silva, Glauber T

    2014-01-01

    We present a theoretical expression for the acoustic interaction force between small spherical particles suspended in an ideal fluid exposed to an external acoustic wave. The acoustic interaction force is the part of the acoustic radiation force on one given particle involving the scattered waves from the other particles. The particles, either compressible liquid droplets or elastic microspheres, are considered to be much smaller than the acoustic wavelength. In this so-called Rayleigh limit, the acoustic interaction forces between the particles are well approximated by gradients of pair-interaction potentials with no restriction on the inter-particle distance. The theory is applied to studies of the acoustic interaction force on a particle suspension in either standing or traveling plane waves. The results show aggregation regions along the wave propagation direction, while particles may attract or repel each other in the transverse direction. In addition, a mean-field approximation is developed to describe ...

  1. Acoustic interaction forces and torques acting on suspended spheres in an ideal fluid

    Lopes, J Henrique; Silva, G T

    2014-01-01

    In this paper, the acoustic interaction forces and torques exerted by an arbitrary time-harmonic wave on a set of N spheres suspended in an inviscid fluid are theoretically analyzed. In so doing, we utilize the partial-wave expansion method to solve the related multiple scattering problem. The acoustic interaction force and torque are computed for a sphere using the farfield radiation force and torque formulas. To exemplify the method, we calculate the interaction forces exerted by an external traveling and standing plane wave on an arrangement of two and three olive-oil droplets in water. The droplets radii are comparable to the wavelength (i.e. Mie scattering regime). The results show that the radiation force may considerably deviates from that exerted solely by the external incident wave. In addition, we find that acoustic interaction torques arise on the droplets when a nonsymmetric effective incident wave interacts with the droplets.

  2. Regulating multiple externalities

    Waldo, Staffan; Jensen, Frank; Nielsen, Max;

    2016-01-01

    Open access is a well-known externality problem in fisheries causing excess capacity and overfishing. Due to global warming, externality problems from CO2 emissions have gained increased interest. With two externality problems, a first-best optimum can be achieved by using two regulatory instrume......Open access is a well-known externality problem in fisheries causing excess capacity and overfishing. Due to global warming, externality problems from CO2 emissions have gained increased interest. With two externality problems, a first-best optimum can be achieved by using two regulatory...

  3. Report of the External Advisory Committee with respect to the report of the Task Force on Safety of Personnel in LHC underground areas following the sector 3-4 accident of 19 September 2008

    Hoppe, A; Petersen, B; Schrader, S; Tartaglia, R

    2009-01-01

    Based on the mandate given by the CERN Director‐General, the Task Force on Safety of Personnel (TFSP) in LHC underground areas following the sector 3‐4 accident of 19‐September‐2008 has carried out an assessment of the situation concerning safety of personnel after the accident.

  4. ExternE National Implementation Finland

    Pingoud, K.; Maelkki, H.; Wihersaari, M.; Pirilae, P. [VTT Energy, Espoo (Finland); Hongisto, M. [Imatran Voima Oy, Vantaa (Finland); Siitonen, S. [Ekono Energy Ltd, Espoo (Finland); Johansson, M. [Finnish Environment Institute, Helsinki (Finland)

    1999-07-01

    ExternE National Implementation is a continuation of the ExternE Project, funded in part by the European Commission's Joule III Programme. This study is the result of the ExternE National Implementation Project for Finland. Three fuel cycles were selected for the Finnish study: coal, peat and wood-derived biomass, which together are responsible for about 40% of total electricity generation in Finland and about 75% of the non-nuclear fuel based generation. The estimated external costs or damages were dominated by the global warming (GW) impacts in the coal and peat fuel cycles, but knowledge of the true GW impacts is still uncertain. From among other impacts that were valued in monetary terms the human health damages due to airborne emissions dominated in all the three fuel cycles. Monetary valuation for ecosystem impacts is not possible using the ExternE methodology at present. The Meri-Pori power station representing the coal fuel cycle is one of the world's cleanest and most efficient coal-fired power plants with a condensing turbine. The coal is imported mainly from Poland. The estimated health damages were about 4 mECU/kWh, crop damages an order of magnitude lower and damages caused to building materials two orders of magnitude lower. The power stations of the peat and biomass fuel cycles are of CHP type, generating electricity and heat for the district heating systems of two cities. Their fuels are of domestic origin. The estimated health damages allocated to electricity generation were about 5 and 6 mECU/kWh, respectively. The estimates were case-specific and thus an generalisation of the results to the whole electricity generation in Finland is unrealistic. Despite the uncertainties and limitations of the methodology, it is a promising tool in the comparison of similar kinds of fuel cycles, new power plants and pollution abatement technologies and different plant locations with each other. (orig.)

  5. ExternE National Implementation Finland

    ExternE National Implementation is a continuation of the ExternE Project, funded in part by the European Commission's Joule III Programme. This study is the result of the ExternE National Implementation Project for Finland. Three fuel cycles were selected for the Finnish study: coal, peat and wood-derived biomass, which together are responsible for about 40% of total electricity generation in Finland and about 75% of the non-nuclear fuel based generation. The estimated external costs or damages were dominated by the global warming (GW) impacts in the coal and peat fuel cycles, but knowledge of the true GW impacts is still uncertain. From among other impacts that were valued in monetary terms the human health damages due to airborne emissions dominated in all the three fuel cycles. Monetary valuation for ecosystem impacts is not possible using the ExternE methodology at present. The Meri-Pori power station representing the coal fuel cycle is one of the world's cleanest and most efficient coal-fired power plants with a condensing turbine. The coal is imported mainly from Poland. The estimated health damages were about 4 mECU/kWh, crop damages an order of magnitude lower and damages caused to building materials two orders of magnitude lower. The power stations of the peat and biomass fuel cycles are of CHP type, generating electricity and heat for the district heating systems of two cities. Their fuels are of domestic origin. The estimated health damages allocated to electricity generation were about 5 and 6 mECU/kWh, respectively. The estimates were case-specific and thus an generalisation of the results to the whole electricity generation in Finland is unrealistic. Despite the uncertainties and limitations of the methodology, it is a promising tool in the comparison of similar kinds of fuel cycles, new power plants and pollution abatement technologies and different plant locations with each other. (orig.)

  6. Unwrapping of DNA-protein complexes under external stretching

    Sakaue, Takahiro; Löwen, Hartmut

    2004-01-01

    A DNA-protein complex modelled by a semiflexible chain and an attractive spherical core is studied in the situation when an external stretching force is acting on one end monomer of the chain while the other end monomer is kept fixed in space. Without stretching force, the chain is wrapped around the core. By applying an external stretching force, unwrapping of the complex is induced. We study the statics and the dynamics of the unwrapping process by computer simulation and simple phenomenolo...

  7. Subatomic forces

    Inside the atom, particles interact through two forces which are never felt in the everyday world. But they may hold the key to the Universe. These ideas on subatomic forces are discussed with respect to the strong force, the electromagnetic force and the electroweak force. (author)

  8. Electroweak Force

    Murdin, P.

    2000-11-01

    The united force that encompasses the electromagnetic force and the weak nuclear force. The unification of these two forces is described by a theory that was devised during the 1960s by Sheldon Glashow, Steven Weinberg and Abdus Salam according to which, at high enough energies, the electromagnetic force and the weak nuclear interaction behave in exactly the same way....

  9. External Radiation Therapy

    Full Text Available ... two different types. There's what we call external beam treatment, which is given from an x-ray ... sources, the difference being that in the external beam the treatment comes from outside the patient, whereas ...

  10. ASH External Web Portal (External Portal)

    Department of Transportation — The ASH External Web Portal is a web-based portal that provides single sign-on functionality, making the web portal a single location from which to be authenticated...

  11. Generalized Network Externality Function

    A. Paothong; G.S. Ladde

    2012-01-01

    In this work, we focus on the development of mathematical modeling of network externality processes. The introduction of the generalized network externality function provides a unified source of a tool for developing and analyzing the planning, policy and performance of the network externality process and network goods/services in a systematic way. This leads to fulfill all existing network externality assumptions as special cases. We study its properties and applications. This study provides...

  12. Preparation of a bifunctional pyrazosulfuron-ethyl imprinted polymer with hydrophilic external layers by reversible addition-fragmentation chain transfer polymerization and its application in the sulfonylurea residue analysis.

    Yang, Meixian; Zhang, Yingying; Lin, Shen; Yang, Xinlin; Fan, Zhijin; Yang, Lixia; Dong, Xiangchao

    2013-09-30

    A new bifunctional pyrazosulfuron-ethyl imprinted polymer was synthesized by the combination of molecular imprinting technology and living radical polymerization. In the synthesis, the pyrazosulfuron-ethyl imprinted polymer was obtained by the reversible addition-fragmentation chain transfer (RAFT) precipitation polymerization followed by grafting poly(glyceryl monomethacrylate) (pGMMA) by the post-RAFT polymerization. In this research, we used polyethylene glycol (PEG) as the polymeric porogen in order to increase the porosity of the material which is a new porogen application in the precipitation polymerization. The imprinted polymer has selectivity for the template and ability of humic acids exclusion which has shown the merits of molecularly imprinted polymers and restricted access materials. An online solid-phase extraction/HPLC method for the analysis of three sulfonylurea residues in soil samples has been developed and validated. The recovery of 81-99% in the spiked levels of 40-200 μg kg(-1) was obtained and the limit of detection (LOD) and limit of quantification (LOQ) were less than 4.8 and 15.9 μg kg(-1) respectively. The results demonstrated that this bifunctional material can be used for the efficient pyrazosulfuron-ethyl extraction in the sulfonylurea residue analysis from environmental samples. PMID:23953454

  13. Lessons learned from external hazards

    This paper presents a study performed by the European Clearinghouse of the Joint Research Centre on Operational Experience for nuclear power plants in cooperation with IRSN and GRS covering events reported by nuclear power plants in relation to external hazards. It summarizes the review of 235 event reports from 3 different databases. The events were grouped in 9 categories according to the nature of the external hazard involved, and the specific lessons learned and recommendations that can be derived from each of these categories are presented. Additional 'cross-cutting' recommendations covering several or all the external hazards considered are also discussed. These recommendations can be useful in preventing this type of events from happening again or in limiting their consequences. The study was launched in 2010 and therefore it does not cover the Fukushima event. This paper presents the main findings and recommendations raised by this study. (orig.)

  14. Food additives

    ... this page: //medlineplus.gov/ency/article/002435.htm Food additives To use the sharing features on this page, please enable JavaScript. Food additives are substances that become part of a food ...

  15. Evaluating climatic response to external radiative forcing during the late Miocene to early Pliocene: New perspectives from eastern equatorial Pacific (IODP U1338) and North Atlantic (ODP 982) locations

    Drury, Anna Joy; John, Cédric M.; Shevenell, Amelia E.

    2016-01-01

    Orbital-scale climate variability during the latest Miocene-early Pliocene is poorly understood due to a lack of high-resolution records spanning 8.0-3.5 Ma, which resolve all orbital cycles. Assessing this variability improves understanding of how Earth's system sensitivity to insolation evolves and provides insight into the factors driving the Messinian Salinity Crisis (MSC) and the Late Miocene Carbon Isotope Shift (LMCIS). New high-resolution benthic foraminiferal Cibicidoides mundulus δ18O and δ13C records from equatorial Pacific International Ocean Drilling Program Site U1338 are correlated to North Atlantic Ocean Drilling Program Site 982 to obtain a global perspective. Four long-term benthic δ18O variations are identified: the Tortonian-Messinian, Miocene-Pliocene, and Early-Pliocene Oxygen Isotope Lows (8-7, 5.9-4.9, and 4.8-3.5 Ma) and the Messinian Oxygen Isotope High (MOH; 7-5.9 Ma). Obliquity-paced variability dominates throughout, except during the MOH. Eleven new orbital-scale isotopic stages are identified between 7.4 and 7.1 Ma. Cryosphere and carbon cycle sensitivities, estimated from δ18O and δ13C variability, suggest a weak cryosphere-carbon cycle coupling. The MSC termination coincided with moderate cryosphere sensitivity and reduced global ice sheets. The LMCIS coincided with reduced carbon cycle sensitivity, suggesting a driving force independent of insolation changes. The response of the cryosphere and carbon cycle to obliquity forcing is established, defined as Earth System Response (ESR). Observations reveal that two late Miocene-early Pliocene climate states existed. The first is a prevailing dynamic state with moderate ESR and obliquity-driven Antarctic ice variations, associated with reduced global ice volumes. The second is a stable state, which occurred during the MOH, with reduced ESR and lower obliquity-driven variability, associated with expanded global ice volumes.

  16. Relativistic Linear Restoring Force

    Clark, D.; Franklin, J.; Mann, N.

    2012-01-01

    We consider two different forms for a relativistic version of a linear restoring force. The pair comes from taking Hooke's law to be the force appearing on the right-hand side of the relativistic expressions: d"p"/d"t" or d"p"/d["tau"]. Either formulation recovers Hooke's law in the non-relativistic limit. In addition to these two forces, we…

  17. Sleep disturbances in chronic progressive external ophthalmoplegia.

    Smits, B.W.; Westeneng, H.J.; Hal, M.A. van; Engelen, B.G.M. van; Overeem, S.

    2012-01-01

    BACKGROUND: Chronic progressive external ophthalmoplegia (CPEO) is a relatively common mitochondrial disorder. In addition to extraocular muscle weakness, various other organs can typically be affected, including laryngeal and limb muscles, cerebrum, cerebellum, and peripheral nerves. Given this mul

  18. External radiation surveillance

    Antonio, E.J.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report describes how external radiation was measured, how surveys were performed, and the results of these measurements and surveys. External radiation exposure rates were measured at locations on and off the Hanford Site using thermoluminescent dosimeters (TLD). External radiation and contamination surveys were also performed with portable radiation survey instruments at locations on and around the Hanford Site.

  19. Review of externality valuation

    Schleisner, Lotte

    1998-11-01

    This report covers the work done regarding assessment of externalities in the project `Investigation of Pricing Incentives in a Renewable Energy Strategy in Thailand`. The report gives a review of different valuation issues, which are used in different externality studies and focuses on why the numbers often are different for the same fuel cycles using different methodologies for assessment of the externalities. The review of externality valuation focuses in this report on the assessment of environmental externalities, and less attention is paid to the non-environmental externalities. The report points out different parameters, which are important to consider when externalities estimated for the same fuel cycle in different studies are compared. For instance some studies transfer dose-response functions and monetization values from other studies. It is in this case important to consider for each of the functions if it is possible to use functions from other studies, or if it is necessary to develop a function for a new region. An important parameter in estimating externalities based on earlier studies is the fact that some studies only include regional and local impacts and do not take the global impacts related to greenhouse gasses into account. Considerable uncertainty is related to the global externalities regarding time horizon for the greenhouse effect, choice of dose-response function and monetization values. Assumptions on famine and the monetization of human life may be the totally dominating factor estimating external costs. 7 studies have been chosen for further analysis and comparison in order to show the variation in external costs. The studies have been chosen in order to cover as well old, well-known studies as new, unknown, but interesting studies. Some of the new studies are based on results from earlier studies, while others implement new ideas concerning the methodology. (au) 21 refs.

  20. Additive Manufacturing Infrared Inspection

    Gaddy, Darrell

    2014-01-01

    Additive manufacturing is a rapid prototyping technology that allows parts to be built in a series of thin layers from plastic, ceramics, and metallics. Metallic additive manufacturing is an emerging form of rapid prototyping that allows complex structures to be built using various metallic powders. Significant time and cost savings have also been observed using the metallic additive manufacturing compared with traditional techniques. Development of the metallic additive manufacturing technology has advanced significantly over the last decade, although many of the techniques to inspect parts made from these processes have not advanced significantly or have limitations. Several external geometry inspection techniques exist such as Coordinate Measurement Machines (CMM), Laser Scanners, Structured Light Scanning Systems, or even traditional calipers and gages. All of the aforementioned techniques are limited to external geometry and contours or must use a contact probe to inspect limited internal dimensions. This presentation will document the development of a process for real-time dimensional inspection technique and digital quality record of the additive manufacturing process using Infrared camera imaging and processing techniques.

  1. The External Mind

    The External Mind: an Introduction by Riccardo Fusaroli, Claudio Paolucci pp. 3-31 The sign of the Hand: Symbolic Practices and the Extended Mind by Massimiliano Cappuccio, Michael Wheeler pp. 33-55 The Overextended Mind by Shaun Gallagher pp. 57-68 The "External Mind": Semiotics, Pragmatism...

  2. Swimmer's Ear (External Otitis)

    ... Can I Help a Friend Who Cuts? Swimmer's Ear (External Otitis) KidsHealth > For Teens > Swimmer's Ear (External Otitis) Print A A A Text Size ... Ryan awoke with a sharp pain in his ear — it really hurt! He remembered having ear infections ...

  3. Possible External Forcing Factors for the Interdecadal Change in the East Asian Winter Monsoon around the Late 1990s%20世纪90年代末东亚冬季风年代际变化的外强迫因子分析

    肖晓; 陈文; 范广洲; 周定文

    2016-01-01

    In this study, the authors investigate the effects of anomalous sea surface temperature (SST), sea ice, and snow cover in the interdecadal change in the East Asian Winter Monsoon (EAWM) that occurred around the late 1990s by using reanalysis datasets from NCEP/NCAR, the Met Office Hadley Centre, the NOAA Climate Diagnostic Center, and the Northern Hemisphere snow cover reanalysis product from NOAA. Characteristics of and mechanisms for the interdecadal changes in the EAWM that occurred around mid-1980s (1976−1988) and late 1990s (1999−2012) are also compared. Results indicate that the interdecadal change in the EAWM that occurred around mid-1980s is characterized by negative temperature anomalies over the entire areas of China. The interdecadal change in the EAWM that occurred around mid-1980s is not related to external forcing including SST and sea ice anomalies. Instead, it is attributed to internal atmospheric dynamics. However, the interdecadal change in the EAWM that occurred around the late 1990s may be attributed to external forcing of SST, sea ice and snow cover anomalies in the preceding fall and winter. Particularly, the warmer SST in the late 1990s over the North Atlantic triggered an atmospheric wave train that propagated eastward and reached East Asia. This wave train intensified Siberian high, leading to a stronger EAWM and negative temperature anomalies over northern East Asia. The reduced sea ice anomalies in the Arctic Ocean and the increased snow cover over the Eurasian Continent in the preceding autumn is also a possible reason for the interdecadal change in the EAWM occurred around the late 1990s. In addition, positive SST anomalies over the tropical western Pacific can lead to convergence and enhanced convection over the maritime continent. As a result, cyclonic circulation anomalies over the tropical eastern Indian Ocean developed via a Gill type response. The anomalous southerly winds to the east of the cyclone eventually led to positive

  4. Labor Force

    Occupational Outlook Quarterly, 2012

    2012-01-01

    The labor force is the number of people ages 16 or older who are either working or looking for work. It does not include active-duty military personnel or the institutionalized population, such as prison inmates. Determining the size of the labor force is a way of determining how big the economy can get. The size of the labor force depends on two…

  5. Additivity dominance

    Paul Rozin

    2009-10-01

    Full Text Available Judgments of naturalness of foods tend to be more influenced by the process history of a food, rather than its actual constituents. Two types of processing of a ``natural'' food are to add something or to remove something. We report in this study, based on a large random sample of individuals from six countries (France, Germany, Italy, Switzerland, UK and USA that additives are considered defining features of what makes a food not natural, whereas ``subtractives'' are almost never mentioned. In support of this, skim milk (with major subtraction of fat is rated as more natural than whole milk with a small amount of natural vitamin D added. It is also noted that ``additives'' is a common word, with a synonym reported by a native speaker in 17 of 18 languages, whereas ``subtractive'' is lexicalized in only 1 of the 18 languages. We consider reasons for additivity dominance, relating it to omission bias, feature positive bias, and notions of purity.

  6. Additivity dominance

    Paul Rozin; Claude Fischler; Christy Shields-Argeles

    2009-01-01

    Judgments of naturalness of foods tend to be more influenced by the process history of a food, rather than its actual constituents. Two types of processing of a ``natural'' food are to add something or to remove something. We report in this study, based on a large random sample of individuals from six countries (France, Germany, Italy, Switzerland, UK and USA) that additives are considered defining features of what makes a food not natural, whereas ``subtractives'' are almost never mentioned....

  7. External Radiation Therapy

    Full Text Available ... for prostate cancer. They really boil down to two different types. There's what we call external beam ... and lay on the table. Count like, "One, two, three," up to 15. So, just about that ...

  8. External Radiation Therapy

    Full Text Available ... boil down to two different types. There's what we call external beam treatment, which is given from ... ready to go. Technician: Okay, Mr. Fabec, here we go. [beeping] Al Fabec: You keep your hands ...

  9. External Radiation Therapy

    Full Text Available ... completely contained in the prostate or when the patient is older the treatment that is frequently used ... external beam the treatment comes from outside the patient, whereas with the interstitial seed treatment the radioactive ...

  10. External Radiation Therapy

    Full Text Available ... older the treatment that is frequently used is radiation therapy. Gunnar Zagars, M.D.: There are different forms ... prostate. [beeping] Narrator: The more common form of radiation therapy is external beam. A typical treatment takes seven ...

  11. Initial external events: floods

    The initial external event, specifically flood in a Nuclear power plant, and the calculation necessary to determine the contribution of this type of event in a Probabilistic Safety Analysis, are presented. (M.I.)

  12. External Radiation Therapy

    Full Text Available ... prostate or when the patient is older the treatment that is frequently used is radiation therapy. Gunnar ... different types. There's what we call external beam treatment, which is given from an x-ray machine, ...

  13. External Radiation Therapy

    Full Text Available ... given from an x-ray machine, and there's a variety called interstitial implantation, which uses radioactive seeds. ... common form of radiation therapy is external beam. A typical treatment takes seven weeks. Gunnar Zagars, M. ...

  14. External Otitis (Swimmer's Ear)

    ... small area, as when pus accumulates in a boil (furuncle) or pimple. Malignant external otitis is a ... Aspergillus niger or Candida albicans, is less common. Boils are usually caused by Staphylococcus aureus . Certain people, ...

  15. External and internal audit

    Froňková, Hana

    2011-01-01

    Dissertation includes problems of internal and external audit. The goal of this work is on the basis teoretical knowledge and information got from experience, to do internal and external audit of fulfilment by drawings of financial subvence. The result of both made audits is final report.Work is composed from three parts, first part- theoretical-describes progress of internal audit, its essence and definitions, regulation frame, which characteristics ought to fulfil an internal auditor, then ...

  16. Force sensing

    Sanders, David

    2007-01-01

    A young child can explore and learn and compensate for unknown dynamics by prodding, pushing, touching, grasping and feeling. Force sensing and software research could soon allow artificial mechanisms to do the same. Force sensing has its roots in strain gauges, piezoelectrics, Wheatstone bridges, automation, robotics, grippers and virtual reality. That force sensing research has now become commonplace and has expanded from those roots to include so much more: video games, athletic equipment,...

  17. External trade development in 2010

    Český statistický úřad

    2011-01-01

    Analysis of the external trade development of the CR in total (turnover, export, import, trade balance). Main factors, which influence the external trade development. Territorial structure (by main blocks and selected countries) and commodity structure (by SITC, rev. 4) of the external trade. Comparisons of the CR external trade development with the external trade development of the other member states of the EU.

  18. Restoring force method and response estimation

    The restoring force method is briefly outlined. Signal modifications that are necessary to successfully determine restoring force functions are discussed and illustrated. Restoring force functions for a base and a force excited system were determined and their effectiveness demonstrated by comparing measured and predicted signals. Additional developments that would make the restoring force method more general are suggested. 5 refs., 12 figs

  19. Attractive and repulsive quantum forces from dimensionality of space

    Bialynicki-Birula, I.; Cirone, M.A.; Dahl, Jens Peder;

    2002-01-01

    Two particles of identical mass attract and repel each other even when there exist no classical external forces and their average relative momentum vanishes. This quantum force depends crucially on the number of dimensions of space.......Two particles of identical mass attract and repel each other even when there exist no classical external forces and their average relative momentum vanishes. This quantum force depends crucially on the number of dimensions of space....

  20. Stochastic dynamics of Arctic sea ice Part I: Additive noise

    Moon, Woosok

    2015-01-01

    We analyze the numerical solutions of a stochastic Arctic sea ice model with constant additive noise over a wide range of external heat-fluxes, $\\Delta F_0$, which correspond to greenhouse gas forcing. The variability that the stochasticity provides to the deterministic steady state solutions (perennial and seasonal ice states) is illustrated by examining both the stochastic paths and probability density functions (PDFs). The principal stochastic moments (standard deviation, mean and skewness) are calculated and compared with those determined from a stochastic perturbation theory described previously by Moon and Wettlaufer (2013). We examine in detail the competing roles of the destabilizing sea ice-albedo-feedback and the stabilizing long-wave radiative loss contributions to the variability of the ice cover under increased greenhouse-gas forcing. In particular, the variability of the stochastic paths at the end of summer shows a clear maximum, which is due to the combination of the increasing importance of t...

  1. Strong Force

    Without the strong force, there could be no life. The carbon in living matter is synthesised in stars via the strong force. Lighter atomic nuclei become bound together in a process called nuclear fusion. A minor change in this interaction would make life impossible. As its name suggests, the strong force is the most powerful of the 4 forces, yet its sphere of influence is limited to within the atomic nucleus. Indeed it is the strong force that holds together the quarks inside the positively charged protons. Without this glue, the quarks would fly apart repulsed by electromagnetism. In fact, it is impossible to separate 2 quarks : so much energy is needed, that a second pair of quarks is produced. Text for the interactive: Can you pull apart the quarks inside a proton?

  2. [Forced Oscillations of DNA Bases].

    Yakushevich, L V; Krasnobaeva, L A

    2016-01-01

    This paper presents the results of the studying of forced angular oscillations of the DNA bases with the help of the mathematical model consisting of two coupled nonlinear differential equations that take into account the effects of dissipation and the influence of an external periodic field. The calculation results are illustrated for sequence of gene encoding interferon alpha 17 (IFNA 17). PMID:27192830

  3. Metasurface external cavity laser

    Xu, Luyao; Curwen, Christopher A.; Hon, Philip W. C.; Chen, Qi-Sheng; Itoh, Tatsuo; Williams, Benjamin S.

    2015-11-01

    A vertical-external-cavity surface-emitting-laser is demonstrated in the terahertz range, which is based upon an amplifying metasurface reflector composed of a sub-wavelength array of antenna-coupled quantum-cascade sub-cavities. Lasing is possible when the metasurface reflector is placed into a low-loss external cavity such that the external cavity—not the sub-cavities—determines the beam properties. A near-Gaussian beam of 4.3° × 5.1° divergence is observed and an output power level >5 mW is achieved. The polarized response of the metasurface allows the use of a wire-grid polarizer as an output coupler that is continuously tunable.

  4. Metasurface external cavity laser

    Xu, Luyao, E-mail: luyaoxu.ee@ucla.edu; Curwen, Christopher A.; Williams, Benjamin S. [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States); California NanoSystems Institute, University of California, Los Angeles, California 90095 (United States); Hon, Philip W. C.; Itoh, Tatsuo [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States); Chen, Qi-Sheng [Northrop Grumman Aerospace Systems, Redondo Beach, California 90278 (United States)

    2015-11-30

    A vertical-external-cavity surface-emitting-laser is demonstrated in the terahertz range, which is based upon an amplifying metasurface reflector composed of a sub-wavelength array of antenna-coupled quantum-cascade sub-cavities. Lasing is possible when the metasurface reflector is placed into a low-loss external cavity such that the external cavity—not the sub-cavities—determines the beam properties. A near-Gaussian beam of 4.3° × 5.1° divergence is observed and an output power level >5 mW is achieved. The polarized response of the metasurface allows the use of a wire-grid polarizer as an output coupler that is continuously tunable.

  5. Checklists for external validity

    Dyrvig, Anne-Kirstine; Kidholm, Kristian; Gerke, Oke; Vondeling, Hindrik

    2014-01-01

    RATIONALE, AIMS AND OBJECTIVES: The quality of the current literature on external validity varies considerably. An improved checklist with validated items on external validity would aid decision-makers in judging similarities among circumstances when transferring evidence from a study setting to an....... The retrieved checklist items were assessed for (i) the methodology used in primary literature, justifying inclusion of each item; and (ii) the number of times each item appeared in checklists. RESULTS: Fifteen papers were identified, presenting a total of 21 checklists for external validity, yielding...... a total of 38 checklist items. Empirical support was considered the most valid methodology for item inclusion. Assessment of methodological justification showed that none of the items were supported empirically. Other kinds of literature justified the inclusion of 22 of the items, and 17 items were...

  6. Conformations and adsorption behavior of poly(allylamine hydrochloride)studied by single molecule force spectroscopy

    2008-01-01

    Poly(allylamine hydrochIoride)(PAH),which is frequently used in fabricating polyelectrolyte multilayer films,was studied by single molecule force spectroscopy(SMFS).Plenty of force-extension curves with a long plateau were obtained in water,indicating that train-like structure was predominant when PAH was adsorbed on the substrate.It was found that the peak-type force-extension curves of PAH in water were not able to be fitted by the modified freely-iointed chain model.Additionally,there was a flat region in the derivative of force-extension curves.Thus.it was inferred that PAH chain in water was in a special conformation and underwent a"conformationaI transition"under the stretching of an external force.This phenomenon did not appear in the SMFS experiment in 1 mol/L urea solution,which indicated that urea was able to break the speciaI conformation.

  7. Productivity Change and Externalities

    Kravtsova, Victoria

    2014-01-01

    This paper contributes to the analysis of the impact of externalities on the host country's total factor productivity by taking into account different dimensions of spillover effects. Namely, engagement in exporting and foreign ownership is generally perceived as being beneficial to individual...... on Hungary. While the country leads the group of post-socialist countries in the amount of attracted foreign direct investments (FDI) the effect of this policy on the economy remains unclear. The research finds that different externalities play a different role in productivity, technological and...

  8. External Liabilities and Crises

    Luis Catão; Gian Milesi-Ferretti

    2013-01-01

    We examine the determinants of external crises, focusing on the role of foreign liabilities and their composition. Using a variety of statistical tools and comprehensive data spanning 1970-2011, we find that the ratio of net foreign liabilities (NFL) to GDP is a significant crisis predictor, and the more so when it exceeds 50 percent in absolute terms and 20 percent of the country-specific historical mean. This is primarily due to net external debt--the effect of net equity liabilities is wea...

  9. Weak Force

    Without the weak force, the sun wouldn't shine. The weak force causes beta decay, a form of radioactivity that triggers nuclear fusion in the heart of the sun. The weak force is unlike other forces: it is characterised by disintegration. In beta decay, a down quark transforms into an up quark and an electron is emitted. Some materials are more radioactive than others because the delicate balance between the strong force and the weak force varies depending on the number of particles in the atomic nucleus. We live in the midst of a natural radioactive background that varies from region to region. For example, in Cornwall where there is a lot of granite, levels of background radiation are much higher than in the Geneva region. Text for the interactive: Move the Geiger counter to find out which samples are radioactive - you may be surprised. It is the weak force that is responsible for the Beta radioactivity here. The electrons emitted do not cross the plastic cover. Why do you think there is some detected radioa...

  10. External Costs as Driving Forces of Land Use Changes

    Dirk Loehr

    2010-01-01

    Land conversion is often not carried out in a sustainable way. The loss of arable land and biodiversity, concern about food security and rising costs of infrastructure due to urban sprawl are just some of the problems under discussion. This paper compares Germany, China and Cambodia. The article points out that, despite huge differences in institutions and governance, unsustainable land use changes mostly have some patterns in common: The beneficiaries of land conversion are often well-organi...

  11. External Costs as Driving Forces of Land Use Changes

    Dirk Loehr

    2010-04-01

    Full Text Available Land conversion is often not carried out in a sustainable way. The loss of arable land and biodiversity, concern about food security and rising costs of infrastructure due to urban sprawl are just some of the problems under discussion. This paper compares Germany, China and Cambodia. The article points out that, despite huge differences in institutions and governance, unsustainable land use changes mostly have some patterns in common: The beneficiaries of land conversion are often well-organized actors, whereas the costs of land conversion are often shifted to poorly organized groups and to society as a whole. A sustainable land use policy has to look for a better coupling of benefits and costs of land use changes. In order to achieve this goal, the article suggests completing the planning law with a suitable economic framework.

  12. Structural changes in precipitated silica induced by external forces

    Schneider, G. J.; Göritz, D.

    2011-01-01

    The morphology of pure precipitated silica, silica filled in polydimethylsiloxane rubber, and silica filled in styrene butadiene rubber was studied by means of small-angle X-ray scattering experiments. The silica at a length scale of a few nanometers consists of primary particles, which form aggregates, and clusters with aggregates as basic units. It is evidenced that the aggregate branching, represented by the mass fractal dimension, and the aggregate diameter are different if pure silica an...

  13. Rural areas development – local needs and external forces

    Těšitel, Jan; Kušová, Drahomíra; Bartoš, Michael

    Warsaw : Polish Academy of Sciences, 2006 - (Florianczyk, Z.; Czapiewski, K.), s. 87-97 ISBN 83-89666-60-X. - (European Rural Development Network. 4) R&D Projects: GA MŽP SM/610/3/03 Institutional research plan: CEZ:AV0Z60870520 Keywords : rural development * local communities * marginality * tourism * protected areas Subject RIV: EH - Ecology, Behaviour

  14. Externalities - an analysis using the EU ExternE-results

    The EU project ExternE quantified the externalities for the different energy technologies. In this work, the ExternE results are used in a MARKAL-analysis for the Nordic countries. The analysis does not go into detail, but gives some interesting indications: The external costs are not fully covered in the Nordic energy systems, the present taxes and charges are not high enough. The emissions from the energy systems would be strongly reduced, if taxes/environmental charges were set at the level ExternE calculate. The emissions from power production would be reduced most. Renewable energy sources and natural gas dominate the energy systems in the ExternE case

  15. External Radiation Therapy

    Full Text Available ... D.: There are different forms of radiation for prostate cancer. They really boil down to two different types. There's what we call external beam treatment, which is given from an x-ray ... the prostate. [beeping] Narrator: The more common form of radiation ...

  16. Stochastic Control - External Models

    Poulsen, Niels Kjølstad

    2005-01-01

    This note is devoted to control of stochastic systems described in discrete time. We are concerned with external descriptions or transfer function model, where we have a dynamic model for the input output relation only (i.e.. no direct internal information). The methods are based on LTI systems and...

  17. External costs of electricity

    This article presents a synthesis of the ExternE project (External costs of Energy) of the European community about the external costs of power generation. Pollution impacts are calculated using an 'impact pathways' analysis, i.e. an analysis of the emission - dispersion - dose-response function - cost evaluation chain. Results are presented for different fuel cycles (with several technological variants) with their confidence intervals. The environmental impact costs are particularly high for coal: for instance, in France, for coal-fired power plants it is of the same order as the electricity retail price. For natural gas, this cost is about a third of the one for coal. On the contrary, the environmental impact costs for nuclear and renewable energies are low, typically of few per cent of the electricity price. The main part of these costs corresponds to the sanitary impacts, in particular the untimely mortality. In order to avoid any controversy about the cost evaluation of mortality, the reduction of the expectation of life due to the different fuel cycles is also indicated and the risks linked with nuclear energy are presented using several comparisons. (J.S.)

  18. External Radiation Therapy

    Full Text Available ... external beam treatment, which is given from an x-ray machine, and there's a variety called interstitial implantation, ... the treatment. You can't really feel the x-rays going into you and so they feel no ...

  19. External Radiation Therapy

    Full Text Available ... prostate or when the patient is older the treatment that is frequently used is radiation therapy. Gunnar Zagars, M.D.: There are different forms ... different types. There's what we call external beam treatment, which is given from an x-ray machine, ...

  20. Entropic forces in Brownian motion

    Roos, Nico

    2013-01-01

    The interest in the concept of entropic forces has risen considerably since E. Verlinde proposed to interpret the force in Newton s second law and Gravity as entropic forces. Brownian motion, the motion of a small particle (pollen) driven by random impulses from the surrounding molecules, may be the first example of a stochastic process in which such forces are expected to emerge. In this note it is shown that at least two types of entropic motion can be identified in the case of 3D Brownian motion (or random walk). This yields simple derivations of known results of Brownian motion, Hook s law and, applying an external (nonradial) force, Curie s law and the Langevin-Debye equation.

  1. Entropic forces in Brownian motion

    Roos, Nico

    2014-12-01

    Interest in the concept of entropic forces has risen considerably since Verlinde proposed in 2011 to interpret the force in Newton's second law and gravity as entropic forces. Brownian motion—the motion of a small particle (pollen) driven by random impulses from the surrounding molecules—may be the first example of a stochastic process in which such forces are expected to emerge. In this article, it is shown that at least two types of entropic force can be identified in three-dimensional Brownian motion. This analysis yields simple derivations of known results of Brownian motion, Hooke's law, and—applying an external (non-radial) force—Curie's law and the Langevin-Debye equation.

  2. Network Externality: An Uncommon Tragedy

    S. J. Liebowitz; Stephen E. Margolis

    1994-01-01

    Economists have defined 'network externality' and have examined putative inframarginal market failures associated with it. This paper distinguishes between network effects and network externalities, where the latter are market failures. The authors argue that while network effects are important, network externalities are theoretically fragile and empirically undocumented. Some network externalities are merely pecuniary. Network ownership or transactions among network participants can internal...

  3. About Radiation Reaction with Force Approach

    Velazquez, Gustavo Lopez

    2015-01-01

    The difficulty of usual approach to radiation reaction is pointed out , and a possible approach based on the force acting to the charged particle which produces the acceleration itself, is presented. This approach brings about an expression such that acceleration is zero whenever the external force is zero.

  4. External costs of electricity generation

    The paper presents advantages connected with the use of electric energy and the hazards due to generation from various energy sources. In the analysis of fossil fuel power plants the latest plants are considered, provided with all emission abatement systems required by the regulations in force in USA and in the European Union. The perspectives of reduction of emissions over the next twenty years are taken into account and the actual emissions from various power plants during the last decade are reviewed. Based on the latest studies conducted by the international teams, e.g. within European Union program ExternE, the methods and data are presented for calculation of health damages due to fossil fuel burning and comparing with the effects of nuclear power plant operation. In all cases the whole chain of activities, from cradle to the grave, has been taken into account. Examples of the comparative analyses performed in EU countries are presented together with the results of analyses done in other countries known from objective approach to various options of power industry as Switzerland. Then the methodology proposed for Polish conditions is described. The analyses of emissions in normal operation compared with the values admissible according to health protection regulations shows that the emissions from modern coal fired power plants involve pollution to the admissible limits of about 100000 times more atmospheric air than the emissions from nuclear power plants. The health damages are similarly much greater for coal fired plants than for nuclear power. After a complex analysis of hazards due to all phases of power generation cycle it is found that nuclear power belongs to those energy sources that make it possible to generate electricity in a way involving the smallest damages to human health. (author)

  5. Attentional Focusing Instructions and Force Production

    David C Marchant

    2011-01-01

    Full Text Available Research progress assessing the role of attentional focusing instructions on skill acquisition and performance has lead researchers to apply this approach to force production tasks. Initial converging evidence indicates that force production tasks are sensitive to verbal instruction; externally focused instructions (onto movement outcomes, or onto the object force is being exerted against are shown to be more beneficial than internally focused instructions (focusing attention onto the movements being executed. These benefits are observed for maximal and accurate force production, as well as the maintenance of force production in prolonged tasks. A range of mechanisms are identified supporting the proposal that an external focus promotes movement efficiency in line with energy and effort conservation. Future research is required to assess how this developing body of work interacts with the broader understanding of psychological and physiological factors implicated in the effective production, maintenance and limitation of maximal or sub-maximal forces.

  6. The physics of cancer: the role of physical interactions and mechanical forces in metastasis

    Wirtz, Denis; Konstantopoulos, Konstantinos; Searson, Peter C.

    2011-01-01

    Metastasis is a complex, multistep process responsible for >90% of cancer-related deaths. In addition to genetic and external environmental factors, the physical interactions of cancer cells with their microenvironment, as well as their modulation by mechanical forces, are key determinants of the metastatic process. We reconstruct the metastatic process and describe the importance of key physical and mechanical processes at each step of the cascade. The emerging insight into these physical in...

  7. External-Memory Multimaps

    Angelino, Elaine; Mitzenmacher, Michael; Thaler, Justin

    2011-01-01

    Many data structures support dictionaries, also known as maps or associative arrays, which store and manage a set of key-value pairs. A \\emph{multimap} is generalization that allows multiple values to be associated with the same key. For example, the inverted file data structure that is used prevalently in the infrastructure supporting search engines is a type of multimap, where words are used as keys and document pointers are used as values. We study the multimap abstract data type and how it can be implemented efficiently online in external memory frameworks, with constant expected I/O performance. The key technique used to achieve our results is a combination of cuckoo hashing using buckets that hold multiple items with a multiqueue implementation to cope with varying numbers of values per key. Our external-memory results are for the standard two-level memory model.

  8. Externalities in Urban Sustainability

    Erik T. Verhoef; Nijkamp, Peter

    2000-01-01

    This paper studies urban sustainability from the perspective ofexternalities. We develop a general spatialequilibrium model of a monocentric city, in which two types ofexternalities occur. On the one hand, pollution inthe industrial centre leads to a spatially differentiateddeterioration of the environmental quality in the residentialarea. On the other hand, the existence of the city is explained byagglomeration economies, represented as simpleMarshallian external benefits in production. We i...

  9. Anomalous phonon behavior of carbon nanotubes: First-order influence of external load

    Aghaei, Amin; Dayal, Kaushik; Elliott, Ryan S.

    2013-01-01

    External loads typically have an indirect influence on phonon curves, i.e., they influence the phonon curves by changing the state about which linearization is performed. In this paper, we show that in nanotubes, the axial load has a direct first-order influence on the long-wavelength behavior of the transverse acoustic (TA) mode. In particular, when the tube is force-free, the TA mode frequencies vary quadratically with wave number and have curvature (second derivative) proportional to the square-root of the nanotube's bending stiffness. When the tube has non-zero external force, the TA mode frequencies vary linearly with wave number and have slope proportional to the square-root of the axial force. Therefore, the TA phonon curves—and associated transport properties—are not material properties but rather can be directly tuned by external loads. In addition, we show that the out-of-plane shear deformation does not contribute to this mode and the unusual properties of the TA mode are exclusively due to bending. Our calculations consist of 3 parts: First, we use a linear chain of atoms as an illustrative example that can be solved in close-form; second, we use our recently developed symmetry-adapted phonon analysis method to present direct numerical evidence; and finally, we present a simple mechanical model that captures the essential physics of the geometric nonlinearity in slender nanotubes that couples the axial load directly to the phonon curves. We also compute the density of states and show the significant effect of the external load.

  10. Use of two-axis joystick for control of externally powered shoulder disarticulation prostheses

    Robert D. Lipschutz, BSME, CP

    2011-07-01

    Full Text Available We explored a new method for simple and accurate control of shoulder movement for externally powered shoulder disarticulation prostheses with a two-axis joystick. We tested 10 subjects with intact shoulders and arms to determine the average amount of shoulder motion and force available to control an electronic input device. We then applied this information to two different input strategies to examine their effectiveness: (1 a traditional rocker potentiometer and a pair of force-sensing resistors and (2 a two-axis joystick. Three nondisabled subjects and two subjects with shoulder disarticulation amputations attempted to control an experimental externally powered shoulder using both control strategies. Two powered arms were tested, one with powered flexion/extension and humeral rotation and one with powered flexion/extension and adduction/abduction. Overwhelmingly, the subjects preferred the joystick control, because it was more intuitively linked with their shoulder movement. Additionally, two motions (one in each axis could be controlled simultaneously. This pilot study provides valuable insight into an effective means of controlling high-level, externally powered prostheses with a two-axis joystick.

  11. Theory of polymer translocation through a flickering nanopore under an alternating driving force

    Sarabadani, Jalal; Ikonen, Timo; Ala-Nissila, Tapio

    2015-01-01

    We develop a theory for polymer translocation driven by a time-dependent force through an oscillating nanopore. To this end, we extend the iso-flux tension propagation theory (IFTP) [Sarabadani \\textit{et al., J. Chem. Phys.}, 2014, \\textbf{141}, 214907] for such a setup. We assume that the external driving force in the pore has a component oscillating in time, and the flickering pore is similarly described by an oscillating term in the pore friction. In addition to numerically solving the mo...

  12. External environment of tertiary education in the Czech Republic

    Švrček, Roman

    2014-01-01

    This bachelor's thesis deals with analysis of external environment of tertiary education institutions in the Czech Republic. In the thesis the analysis of the environment is done according to Porter's model of five forces -- given model is also critically looked upon to verify it's suitability to task at hand. Main goal of the thesis is however to suggest changes and recommendations that should lead to influencing the external environment in favor of instututions operating in the field of ter...

  13. EXTERNAL BUSINESS ENVIRONEMENT PROBLEMS AND OPPORTUNITIES IN REZEKNE CITY

    Litavniece, Lienīe; Znotiņa, Daina

    2015-01-01

    Entrepreneurship is an essential driving force for the social and economic development of any city. Well-arranged external environment is a fundamental prerequisite in order to motivate local entrepreneurs and to attract investors for establishing new businesses and development of the existing ones. An important role in the development of the external business environment is played by the political position of the local government and the process regulations at the city. The paper aims to car...

  14. Which factors facilitate the management of external knowledge?

    Osmonalieva, Zarina; Rao, Laxmi

    2008-01-01

    Date: 2008-06-04 Course: EIK 034 Masters Thesis Authors: Laxmi Rao & Zarina Osmonalieva Tutor: Ole Liljefors Title: Which factors facilitate the management of external knowledge? Introduction: Today more and more organisations are realising that handling internal and external knowledge is a key issue for successful performance. Different theories describe the importance of this topic, for instance, Porter’s Five Forces model and Hedman & Kalling’s General Business Model demonstrate ho...

  15. External plans for radiological emergency

    Since 1989, the National Institute of Nuclear Research in Mexico shares in the task of Food and Water Control corresponding to the FT-86 task force of External Plans for Radiological Emergency (PERE), in charge of the Veracruz Health Services. In the PERE preparation stage previous actions are necessary developed for the preparation and updating of this plan and the task organization with the purpose to maintaining standing and operable in any time and circumstance, the capability to response in the face of an emergency. This stage englobes activities which must be realized before to carry out the Plan as they are the specialized training of personnel which participates and the execution of exercises and simulacrums. Until 1998, training and exercises for this task had been realized under diverse possible sceneries but in conditions that simulated the presence of radioactive material. For this reason, it should be emphasized the training realized during the days 6th, 7th, 8th July, 1999, in the emergency planning zone of the Plan, which to carry out using radioactive material. The National Institute of Nuclear Research had in charge of the training. This work describes all the activities for the realization of this training. (Author)

  16. 波形钢腹板连续箱梁剪滞效应引起的附加轴力分析%Additional Axial Force Analysis Caused by Shear lag Effect of Cintinuous Box-girder Bridge with Corrugated Steel Webs

    吴焕庆; 张俊波; 刘世忠; 冀伟; 满自亭

    2013-01-01

    Under the condition of the plane section assumption and without considering the inertia moment of corrugated steel webs,this paper establishes the additional axial force formula for the two spans continuous box-girder bridge with corrugated steel webs based on a cubic parabola shear lag warping function.At the same time,it leads into the additional axial force stress ratio coefficient.Then it analyses the impact of additional axial stress to the influence degree of structural mechanical,which is based on the continuous box-girder bridge with corrugated steel webs under the full cross-uniformly distributed load and mid-span concentrated load.It shows that the value of additional axial stress can be ignored because the additional axial force stress ratio coefficient under the full cross-uniformly distributed load and the mid-span concentrated load is less than 1%.%基于平截面假定并不计波形钢腹板惯性矩,建立了波形钢腹板两跨连续箱梁在三次抛物线剪滞翘曲位移函数下的附加轴力计算式.引入附加轴向应力比系数,分析了波形钢腹板混凝土两跨连续梁在均布荷戢及跨中集中荷载作用下,附加轴向应力对结构受力性能的影响,分析表明:在两种荷栽工况下,附加轴向应力比系数均小于1%,可以忽略其效应.

  17. Graphene in external fields

    Feng, Sze-Shiang; Mochena, Mogus

    2010-01-01

    A general discussion of graphene in external electromagnetic field is provided. In general, the formulation is not Lorentz invariant because of Zeeman energy. But it can be restored approxiamtely in the case of strong magnetic field, the condition when quantum Hall effect is observed. Besides obtaining the well-known Hall conductance $\\frac{4q^2}{h}(L+1/2)$, we also predict that the sequence of Hall conductance $\\frac{4q^2}{h}L$,which contains the newly observed Hall conductance $\\frac{4q^2}{...

  18. Stiffness of modified Type 1a linear external skeletal fixators.

    Reaugh, H F; Rochat, M C; Bruce, C W; Galloway, D S; Payton, M E

    2007-01-01

    Modifications of a Type 1a external skeletal fixator (ESF) frame were evaluated by alternately placing transfixation pins on opposite sides of the connecting rod (Type 1a-MOD) or by placing additional connecting rods on either of the two inside (Type 1a-INSIDE) or two outside (Type 1a-OUTSIDE) transfixation pins. The objective of this study was to evaluate the stiffness of these modifications in terms of axial compression (AC), cranial-caudal bending (CCB), and medial-lateral bending (MLB). We hypothesized that these designs would allow significant increase in unilateral frame stiffness, over Type 1a, without proportional increase in frame complexity or technical difficulty of application. All of the ESF frames were constructed using large IMEX SKtrade mark clamps, 3.2 mm threaded fixation pins, 9.5 mm carbon fibre connecting rods and Delrin rods as bone models. Nine, eight pin frames of each design were constructed, and subjected to repetitive non-destructive loading forces (AC, CCB, MLB) using a materials testing machine. Frame construct stiffness for each force (AC, CCB, MLB) was derived from load-deformation curve analysis and displayed in N/mm. Data revealed the 1a-MOD and 1a-OUTSIDE constructs had significantly increased stiffness in CCB and AC as compared to the Type 1a constructs while all of the modified constructs were significantly stiffer in MLB than the Type 1a constructs. PMID:18038001

  19. Numerical simulation of subcooled flow boiling in vertical rectangular channel under additional inertial forces%附加惯性力作用下竖直矩形流道内过冷流动沸腾的数值模拟

    魏敬华; 潘良明; 徐建军; 黄彦平

    2011-01-01

    The additional inertial forces caused by rolling conditions would affect the two-phase flow pressure drop and the forces acting on the bubbles. Numerical simulation of subcooled flow boiling in a vertical rectangular channel under the effect of additional inertial forces has been carried out considering the energy and mass transfer during phase change. The two-phase flow model of volume-of-fluid (VOF) was adopted. The liquid-vapor interface was captured using the piecewise linearity interpolation calculation (PLIC) geometry restructuring method. The pressure, velocity, temperature distribution around an isolated bubble, the secondary flow phenomenon caused by evaporation and condensation, and the evolution of velocity vector during bubble coalescence were obtained, which agree well with the results in literature. Compared with motion less conditions, the pressure drop was enlarged by the effect of additional inertial forces. In subcooled flow boiling, the pressure drop fluctuates because of the vapor generation. The fluctuation becomes more severe while heat flux increases. Compared with the effects of other forces acting on bubbles, the effect of additional inertial forces can be neglected. However, the fluctuation of flow rate caused by rolling would change the shear lift force, drag force and hydrodynamic pressure force significantly and influence the heat transfer in boiling flow.%摇摆条件下附加惯性力的作用会对两相流动的压降及汽泡受力产生影响.考虑相变能量和质量输运,采用流体体积(VOF)多相流模型对附加惯性力条件下竖直矩形流道内过冷流动沸腾进行了数值模拟.汽液界面位置通过分段线性插值(PLIC)的方法获得.模拟结果获得了孤立汽泡周围压力、速度、温度分布以及二次流动现象,分析了汽泡聚合过程汽泡形态及内部速度矢量的演变过程,模拟结果与文献中结论吻合良好.附加惯性力作用使得流动压降比静止条件下

  20. Electrostatic patch potentials in Casimir force measurements

    Garrett, Joseph; Somers, David; Munday, Jeremy

    2015-03-01

    Measurements of the Casimir force require the elimination of the electrostatic force between interacting surfaces. The force can be minimized by applying a potential to one of the two surfaces. However, electrostatic patch potentials remain and contribute an additional force which can obscure the Casimir force signal. We will discuss recent measurements of patch potentials made with Heterodyne Amplitude-Modulated Kelvin Probe Force Microscopy that suggest patches could be responsible for >1% of the signal in some Casimir force measurements, and thus make the distinction between different theoretical models of the Casimir force (e.g. a Drude-model or a plasma-model for the dielectric response) difficult to discern.

  1. Environmental external effects from wind power based on the EU ExternE methodology

    Ibsen, Liselotte Schleisner; Nielsen, Per Sieverts

    1998-01-01

    The European Commission has launched a major study project, ExternE, to develop a methodology to quantify externalities. A “National Implementation Phase”, was started under the Joule II programme with the purpose of implementing the ExternE methodology in all member states. The main objective of...... the Danish part of the project is to implement the framework for externality evaluation, for three different power plants located in Denmark. The paper will focus on the assessment of the impacts of the whole fuel cycles for wind, natural gas and biogas. Priority areas for environmental impact...

  2. External Link Policy | Division of Cancer Prevention

    The following graphic notice means that you are leaving the DCP Web site: (link is external)This external link provides additional information that is consistent with the intended purpose of DCP.The National Cancer Institute (NCI) cannot attest to the accuracy of a non-federal site.Linking to a non-federal site does not constitute an endorsement by HHS or any of its employees of the sponsors or the information and products presented on the site.You will be subject to the destination site |

  3. Automatic Planning of External Search Engine Optimization

    Vita Jasevičiūtė

    2015-07-01

    Full Text Available This paper describes an investigation of the external search engine optimization (SEO action planning tool, dedicated to automatically extract a small set of most important keywords for each month during whole year period. The keywords in the set are extracted accordingly to external measured parameters, such as average number of searches during the year and for every month individually. Additionally the position of the optimized web site for each keyword is taken into account. The generated optimization plan is similar to the optimization plans prepared manually by the SEO professionals and can be successfully used as a support tool for web site search engine optimization.

  4. ExternE: Externalities of energy Vol. 3. Coal and lignite

    methodological issues was reached on both sides of the Atlantic. Since 1993 the study has continued in Europe as the ExternE-Project, and now involves an international team of more than 30 organisations. The current study has three main objectives: 1. to design a unified methodology for quantifying the various social costs associated with the production and consumption of energy; 2. to use the methodology to evaluate the external costs of incremental use of different fuel cycles in different locations in the European Union; 3. to identify critical methodological issues and research requirements. At the same time as the publication of the present report, further reports are being published on the other major fuel cycles for electricity generation, including uranium, oil, gas, wind and hydro. A further volume, providing greater detail on the methodology used for assessment of the impacts of the fossil fuel cycles and their valuation is also being published. Additional reports on other fuel cycles, and implementation of the methodology in different countries will follow shortly. This document assesses the progress made in quantifying environmental and health damages associated with the coal and lignite fuel cycles. Estimates of impacts have been made following critical review of existing data and models rather than from original basic research. This review has been performed by a multi-disciplinary team including specialists in the fields of health, forestry, ecology, materials science, atmospheric chemistry and physics, energy technology, computer science and economics. Wherever possible we have used exactly the same methodology to quantify the same form of damage for each fuel cycle and for each location. However, some differences will be observed in the assessment of the fuel cycles considered in this report. These arise largely through the status of development of the methodology when certain parts of the work were completed. Wherever possible these differences have been

  5. Axiomatics for the external numbers of nonstandard analysis

    Dinis, Bruno; Berg, Imme van den

    2016-01-01

    Neutrices are additive subgroups of a nonstandard model for the real numbers. An external number is the algebraic sum of a (hyper)real number and a neutrix. Due to the stability by some shifts, external numbers may be seen as mathematical models for orders of magnitude. The algebraic properties of external numbers gave rise to so-called solids, which are extensions of ordered fields, having a restricted distributivity law. However, necessary and sufficient conditions can be given for distribu...

  6. Parametric study on sequential deconvolution for force identification

    Lai, Tao; Yi, Ting-Hua; Li, Hong-Nan

    2016-09-01

    The force identification can be mathematically viewed as the mapping from the observed responses to external forces through a matrix filled with system Markov parameters, which makes it difficult or even impossible for long time duration. A potentially efficient solution is to sequentially perform the identification processing. This paper presents a parametric study on the sequential deconvolution input reconstruction (SDR) method, which was proposed by Bernal. The behavior of the SDR method due to the effects of window parameters, noise levels and sensor configurations is investigated. In addition, a new normalized standard deviation of the reconstruction error over time is derived to cover the effect of only independent noise entries. The sinusoidal and band-limited white noise excitations are tested to be identified with good accuracy even with 10% noise. The simulation results yield various conclusions that may be helpful to engineering practitioners.

  7. Quantum Statistics of a Forced Oscillator with a Time-Dependent Driving Force

    刘文森

    2003-01-01

    Quantum statistics of a forced harmonic oscillator acted upon by a time-dependent external force are derived using the Wilcox trick and the time-dependent inhomogeneous Bogoliubov transformation formalism.The internal energy,fluctuation of the particle-number average and entropy of this nonequilibrium system are presented explicitly.

  8. Magnus Force and Aharonov-Bohm Effect in Superfluids

    Sonin, E. B.

    2001-01-01

    The paper addresses the problem of the transverse force (Magnus force) on a vortex in a Galilean invariant quantum Bose liquid. Interaction of quasiparticles (phonons) with a vortex produces an additional transverse force (Iordanskii force). The Iordanskii force is related to the acoustic Aharonov--Bohm effect.Connection of the effective Magnus force with the Berry phase is also discussed.

  9. External Measures of Cognition

    Osvaldo Cairo

    2011-10-01

    Full Text Available The human brain is undoubtedly the most impressive, complex and intricate organ that has evolved over time. It is also probably the least understood, and for that reason, the one that is currently attracting the most attention. In fact, the number of comparative analyses that focus on the evolution of brain size in Homo sapiens and other species has increased dramatically in recent years. In neuroscience, no other issue has generated so much interest and been the topic of so many heated debates as the difference in brain size between socially defined population groups, both its connotations and implications. For over a century, external measures of cognition have been related to intelligence. However, it is still unclear whether these measures actually correspond to cognitive abilities. In summary, this paper must be reviewed with this premise in mind.

  10. Bevalac external beamline optics

    This handbook is intended as an aid for tuning the external particle beam (EPB) lines at the Lawrence Berkeley Laboratory's Bevalac. The information contained within will be useful to the Bevalac's Main Control Room and experimenters alike. First, some general information is given concerning the EPB lines and beam optics. Next, each beam line is described in detail: schematics of the beam line components are shown, all the variables required to run a beam transport program are presented, beam envelopes are given with wire chamber pictures and magnet currents, focal points and magnifications. Some preliminary scaling factors are then presented which should aid in choosing a given EPB magnet's current for a given central Bevalac field. Finally, some tuning hints are suggested

  11. Unification of fundamental forces

    Abdus Salam, a Fellow of St. John's College, Cambridge, provides an accessible overview of modern particle physics and the quest for the unification of the fundamental forces, the electromagnetic, strong nuclear weak nuclear and gravitational. A major theme of the lecture is the way in which the theoretical physicists approach the task of imposing orders on a seemingly chaotic universe. A secondary theme is that the electroweak force is most likely to be the force of life. The theme of the philosophy behind the work of theorists is continued in two additional lectures by Werner Heisenberg and Paul Dirac which give fascinating insights into the modus operandi and work of two of the founders of quantum mechanics. (author)

  12. Model Additional Protocol

    Since the end of the cold war a series of events has changed the circumstances and requirements of the safeguards system. The discovery of a clandestine nuclear weapons program in Iraq, the continuing difficulty in verifying the initial report of Democratic People's Republic of Korea upon entry into force of their safeguards agreement, and the decision of the South African Government to give up its nuclear weapons program and join the Treaty on the Non-Proliferation of Nuclear Weapons have all played a role in an ambitious effort by IAEA Member States and the Secretariat to strengthen the safeguards system. A major milestone in this effort was reached in May 1997 when the IAEA Board of Governors approved a Model Protocol Additional to Safeguards Agreements. The Model Additional Protocol was negotiated over a period of less than a year by an open-ended committee of the Board involving some 70 Member States and two regional inspectorates. The IAEA is now in the process of negotiating additional protocols, State by State, and implementing them. These additional protocols will provide the IAEA with rights of access to information about all activities related to the use of nuclear material in States with comprehensive safeguards agreements and greatly expanded physical access for IAEA inspectors to confirm or verify this information. In conjunction with this, the IAEA is working on the integration of these measures with those provided for in comprehensive safeguards agreements, with a view to maximizing the effectiveness and efficiency, within available resources, the implementation of safeguards. Details concerning the Model Additional Protocol are given. (author)

  13. Internalizing Externalities through Payments for Environmental Services

    Sudarsono Soedomo

    2012-08-01

    Full Text Available Forest ecosystems, including plantation forests, provide goods and services that are marketable and non-marketable. Positive externalities produced by forest ecosystems are rarely considered in pricing of marketable products that result in economic inefficiencies. Internalizing externalities is required to improve the economic efficiency. The traditional way to internalize an externality is by providing subsidies or imposing taxes. Recently, payments for environmental services  are receiving more attention as an instrument for internalizing externalities provided by forest ecosystems. This promising alternative to improve our environment needs to be studied more extensively. In this paper, it can be indicated theoretically that the Pigovian tax, as a traditional way of addressing environmental problems, is able to mimic the result derived from the employment of environmental services payment. The difference is that environmental services payment improves the welfare of environmental service producers, whereas the Pigovian tax reduces it. A positive Pigovian tax increases the optimal rotation, which is positively associated with environmental improvement, but certainly reduces forest owner's welfare. This difference should be taken into account in the public policymaking so that perverse incentive may be avoided. Payment for environmental services  as an additional income to forest growers, not as alternative source of income, is a potential tool to address simultaneously issues of environment and poverty that are frequently contested.Keywords: externalities, payments for environmental services, tax, perverse incentive, social welfare

  14. Medium-assisted vacuum force

    Tomas, M S

    2005-01-01

    We discuss some implications of a very recently obtained result for the force on a slab in a planar cavity based on the calculation of the vacuum Lorentz force [C. Raabe and D.-G. Welsch, Phys. Rev. A 71, 013814 (2005)]. We demonstrate that, according to this formula, the total force on the slab consists of a medium-screened Casimir force and, in addition to it, a medium-assisted force. The sign of of the medium-assisted force is determined solely by the properties of the cavity mirrors. In the Lifshitz configuration, this force is proportional to 1/d at small distances and is very small compared with the corresponding van der Waals force. At large distances, however, it is proportional to 1/d^4 and is comparable with the Casimir force, especially for denser media. The exponents in these power laws decrease by 1 in the case of a thin slab. The formula for the medium-assisted force also describes the force on a layer of the cavity medium, which has similar properties. For dilute media, it implies an atom-mirro...

  15. Tailoring the thermal Casimir force with graphene

    Svetovoy, V.; Moktadir, Z.; Elwenspoek, M; Mizuta, H.

    2011-01-01

    – The Casimir interaction is omnipresent source of forces at small separations between bodies, which is difficult to change by varying external conditions. Here we show that graphene interacting with a metal can have the best known force contrast to the temperature and the Fermi level variations. In the distance range 50–300nm the force is measurable and can vary a few times for graphene with a bandgap much larger than the temperature. In this distance range the main part of the force is due ...

  16. DNA under Force: Mechanics, Electrostatics, and Hydration

    Jingqiang Li

    2015-02-01

    Full Text Available Quantifying the basic intra- and inter-molecular forces of DNA has helped us to better understand and further predict the behavior of DNA. Single molecule technique elucidates the mechanics of DNA under applied external forces, sometimes under extreme forces. On the other hand, ensemble studies of DNA molecular force allow us to extend our understanding of DNA molecules under other forces such as electrostatic and hydration forces. Using a variety of techniques, we can have a comprehensive understanding of DNA molecular forces, which is crucial in unraveling the complex DNA functions in living cells as well as in designing a system that utilizes the unique properties of DNA in nanotechnology.

  17. Detecting Chameleons through Casimir Force Measurements

    Brax, Philippe; van de Bruck, Carsten; Davis, Anne-Christine; Mota, David F.; Shaw, Douglas

    2007-01-01

    The best laboratory constraints on strongly coupled chameleon fields come not from tests of gravity per se but from precision measurements of the Casimir force. The chameleonic force between two nearby bodies is more akin to a Casimir-like force than a gravitational one: The chameleon force behaves as an inverse power of the distance of separation between the surfaces of two bodies, just as the Casimir force does. Additionally, experimental tests of gravity often employ a thin metallic sheet ...

  18. Rindler force at large distances

    Grumiller, Daniel

    2011-01-01

    Given some assumptions it is possible to derive the most general theory of gravity at large distances. The force law derived from this theory contains a Rindler term in addition to well-known contributions, a Schwarzschild mass and a cosmological constant. The same force law recently was confronted with solar system precision data. The Rindler force, if present in Nature, has intriguing consequences for gravity at large distances. In particular, the Rindler force is capable of explaining about 10% of the Pioneer anomaly and simultaneously ameliorates the shape of galactic rotation curves.

  19. Radiative forcing by contrails

    Meerkoetter, R.; Schumann, U. [DLR Oberpfaffenhofen, Wessling (Germany). Inst. fuer Phys. der Atmosphaere; Doelling, D.R.; Minnis, P. [National Aeronautics and Space Administration, Hampton, VA (United States). Langley Research Center; Nakajima, T.; Tsushima, Y. [Tokyo Univ. (Japan). Center for Climate System Research

    1999-08-01

    A parametric study of the instantaneous radiative impact of contrails is presented using three different radiative transfer models for a series of model atmospheres and cloud parameters. Contrails are treated as geometrically and optically thin plane parallel homogeneous cirrus layers in a static atmosphere. The ice water content is varied as a function of ambient temperature. The model atmospheres include tropical, midlatitude, and subarctic summer and winter atmospheres. Optically thin contrails cause a positive net forcing at top of the atmosphere. At the surface the radiative forcing is negative during daytime. The forcing increases with the optical depth and the amount of contrail cover. At the top of the atmosphere, a mean contrail cover of 0.1% with average optical depth of 0.2 to 0.5 causes about 0.01 to 0.03 Wm{sup -2} daily mean instantaneous radiative forcing. Contrails cool the surface during the day and heat the surface during the night, and hence reduce the daily temperature amplitude. The net effect depends strongly on the daily variation of contrail cloud cover. The indirect radiative forcing due to particle changes in natural cirrus clouds may be of the same magnitude as the direct one due to additional cover. (orig.) 78 refs.

  20. Radiative forcing by contrails

    R. Meerkötter

    Full Text Available A parametric study of the instantaneous radiative impact of contrails is presented using three different radiative transfer models for a series of model atmospheres and cloud parameters. Contrails are treated as geometrically and optically thin plane parallel homogeneous cirrus layers in a static atmosphere. The ice water content is varied as a function of ambient temperature. The model atmospheres include tropical, mid-latitude, and subarctic summer and winter atmospheres. Optically thin contrails cause a positive net forcing at top of the atmosphere. At the surface the radiative forcing is negative during daytime. The forcing increases with the optical depth and the amount of contrail cover. At the top of the atmosphere, a mean contrail cover of 0.1% with average optical depth of 0.2 to 0.5 causes about 0.01 to 0.03 Wm-2 daily mean instantaneous radiative forcing. Contrails cool the surface during the day and heat the surface during the night, and hence reduce the daily temperature amplitude. The net effect depends strongly on the daily variation of contrail cloud cover. The indirect radiative forcing due to particle changes in natural cirrus clouds may be of the same magnitude as the direct one due to additional cover.

    Key words. Atmospheric composition and structure (aerosols and particles · Meteorology and atmospheric dynamics (climatology · radiative processes

  1. EQUILIBRIUM CONDITION OF WEDGE-TYPE COUNTERPART WITHOUT EXTERNAL STRESSES

    Y. Vasilevich

    2014-10-01

    Full Text Available An equilibrium condition on a wedge-type counterpart without external stresses and with approaches of dislocation mezoscopic model has been derived in the paper. The paper describes balanced length dependencies of the wedge-type counterpart on forces that resist to motion of twinning dislocations.

  2. RC T-Beams Externally Prestressed with Unbonded CFRP

    Schmidt, Jacob Wittrup; Bennitz, Anders; Nilimaa, Jonny;

    2010-01-01

    An experimental test series with seven beams externally prestressed with unbonded CFRP 7 (Carbon Fibre Reinforced Polymer) tendons has been performed. Presence of deviator, initial 8 tendon depth and prestressing force are varied. Results and behaviors are compared to 9 common beam theory, matchi...

  3. Results of wind tunnel tests at Mach 5 on the .004 scale model 2A configuration space shuttle to determine proximity effects and orbiter control effectiveness during orbiter/external tank abort separation (IAG)

    Garton, W. P.

    1974-01-01

    Results from tests in the NASA/MSFC Trisonic Wind Tunnel on 0.004-Scale Orbiter and External Tank Force Models in Close Proximity (RTLS Abort Separation Conditions) are presented. The primary test objectives were to obtain data concerning proximity effects on the aerodynamic forces and moments experienced by Vehicle 2A Configuration Shuttle Orbiter and External Tank during an abort separation (Return to Launch Site) at a Mach number of 5. Additionally, data on orbiter control effectiveness during such an abort was obtained. Proximity effects were investigated for relative angles of incidence from minus 5 deg to plus 10 deg of the orbiter FRL with respect to the external tank centerline over a range of vertical and longitudinal displacements from the mated position to 2.5 tank diameters below and 3 tank diameters aft of the mated position.

  4. IRIS Toxicological Review of Methanol (Noncancer) (Revised External Review Draft)

    EPA is seeking additional public comment and external peer review of the scientific basis supporting the human health hazard and dose-response assessment of methanol (noncancer). Teleconference Details: The public may participate in th...

  5. Volumes and doses for external radiotherapy - Definitions and recommendations

    The report contains definitions of volume and dose parameters for external radiotherapy. In addition the report contains recommendations for use, documentation and minimum reporting for radiotherapy of the individual patient.(Author)

  6. Methods for quantifying environmental externalities

    The quantification of environmental externalities is a complex and often subjective task. The difficulty of reliably expressing complex and uncertain relationships between environmental pollutants and the resulting damages and then expressing these damages in dollar costs, results in a wide divergence of opinions regarding the appropriate environmental externality values. Below is a review of the generally accepted methods for incorporating environmental externalities into the resource evaluation process and for quantifying environmental externalities in terms of monetary values. Environmental externalities are open-quotes the cost of environmental damages caused by a project or activity for which compensation to affected parties does not occur.close-quote (Massachusetts Department of Public Utilities, 86-36-G, p. 77) An example of an environmental externality for the electric utility industry are the costs imposed on society of electric generating units uncontrolled (residual) emissions, e.g., the damage costs of acid rain caused by the sulfur dioxide emissions from Midwestern power plants. These costs are external since they are borne by society in general, not considered by the electric utilities in planning. Public awareness of the externality costs of acid rain has resulted in legislation requiring utilities to reduce their sulfur dioxide emissions and will cause electric utilities to reflect cost in their planning and in overall costs of electricity. Environmental externalities can be incorporated into utilities' resource planning processes in several ways. Two methods receiving the most attention are a weighting and ranking approach and the monetization of externalities, i.e., the expression of externality values in dollars. The monetization approach is more complex and has received wider acceptance from regulators. Consequently, this discussion focuses primarily on methods for monetizing externalities

  7. Spectroscopic Monitoring of Mechanical Forces during Protein Folding by using Molecular Force Probes.

    Stauch, Tim; Hoffmann, Marvin T; Dreuw, Andreas

    2016-05-18

    Detailed folding pathways of proteins are still largely unknown. Real-time monitoring of mechanical forces acting in proteins during structural transitions would provide deep insights into these highly complex processes. Here, we propose two molecular force probes that can be incorporated into the protein backbone to gain insight into the magnitude and direction of mechanical forces acting in proteins during natural folding and unfolding through their optical spectroscopic response. In fact, changes in the infrared and Raman spectra are proportional to the mechanical force deforming the force probes, and the relevant bands can be intensified and shifted to a transparent window in the protein spectrum by isotopic substitution. As a result, the proposed molecular force probes can act as "force rulers", allowing the spectroscopic observation and measurement of mechanical forces acting within the proteins under natural conditions without external perturbation. PMID:26928925

  8. Solar and atmospheric forcing on mountain lakes.

    Luoto, Tomi P; Nevalainen, Liisa

    2016-10-01

    We investigated the influence of long-term external forcing on aquatic communities in Alpine lakes. Fossil microcrustacean (Cladocera) and macrobenthos (Chironomidae) community variability in four Austrian high-altitude lakes, determined as ultra-sensitive to climate change, were compared against records of air temperature, North Atlantic Oscillation (NAO) and solar forcing over the past ~400years. Summer temperature variability affected both aquatic invertebrate groups in all study sites. The influence of NAO and solar forcing on aquatic invertebrates was also significant in the lakes except in the less transparent lake known to have remained uniformly cold during the past centuries due to summertime snowmelt input. The results suggest that external forcing plays an important role in these pristine ecosystems through their impacts on limnology of the lakes. Not only does the air temperature variability influence the communities but also larger-scale external factors related to atmospheric circulation patterns and solar activity cause long-term changes in high-altitude aquatic ecosystems, through their connections to hydroclimatic conditions and light environment. These findings are important in the assessment of climate change impacts on aquatic ecosystems and in greater understanding of the consequences of external forcing on lake ontogeny. PMID:27220094

  9. International labor migration and external debt.

    Bustamante, J A

    1987-01-01

    The prevailing Mexican and US definitions of undocumented migration are poles apart. The US views it as a criminal problem. Mexicans view the undocumented migrants as actors in an economic game in which the rules are extremely disadvantageous to these migrants. Migrants themselves and their communities view the undocumented as a positive element. It is necessary to move toward a bilateral focus and bilateral negotiation on the issue of migratory workers. This proposal derives from several assumptions: 1) the external debt is a bilateral or multilateral issue, 2) it is important to avoid forcing debtor countries to choose between stimulating economic growth or making payment on their foreign debt, 3) prevailing public opinion in the US favors halting undocumented migration, 4) the US views the migration of undocumented Mexicans as the result of forces endogenous to Mexico and exogenous to the US, 5) the US views both Mexico's ability to make payment on its external debt and to halt emigration as tied to the Mexican government's ability or inability to reconcile political stability with scarce monetary resources, and 6) political instability in Mexico could augment emigration to the US and undermine Mexico's ability to address its foreign debt. The following proposal suggests means to link negotiation on the external debt to that of undocumented migration: 1) The Mexican government could reach an accord with the US to channel a portion of the actual interest on the external debt as a fund to be invested in Mexico to construct a system of labor intensive agroindustrial productive units designed to attract former or potential migratory workers; 2) the total amount of these funds would be deducted from interest payments on the principal of the actual external debt and redefined as an ad hoc loan to Mexico to finance these production units; 3) part of the production from these units would be incorporated into ongoing US food relief and food assistance programs; 4) the

  10. Force-induced denaturation of RNA

    Gerland, U.; Bundschuh, R.; Hwa, T.

    2001-01-01

    We describe quantitatively a RNA molecule under the influence of an external force exerted at its two ends as in a typical single-molecule experiment. Our calculation incorporates the interactions between nucleotides by using the experimentally-determined free energy rules for RNA secondary structure and models the polymeric properties of the exterior single-stranded regions explicitly as elastic freely-jointed chains. We find that in spite of complicated secondary structures, force-extension...

  11. Ultrasensitive Force Detection and Applications to Biological Systems

    Kenny, Thomas

    2001-03-01

    For many years, researchers have developed a variety of micromechanical devices for a range of applications. The majority of these devices are based on micromechanical force transducers to convert external physical signals into electrical signals. The force sensing capabilities of these devices are remarkable - it is possible to design devices with force resolution ranging from milli-N to atto-N within this technology. In addition to the conventional applications for MEMS devices, it is possible to tailor these designs to allow interesting scientific measurements on biological systems. For example, there are active research communities investigating cellular adhesion, protein folding, and animal locomotion. In all of these cases, the basic questions are mechanical in nature, and direct force measurements can provide new insight. This talk will review some ongoing biological research that makes use of MEMS devices, and discuss opportunities for new directions. Collaborators on this research include : Yiching Liang, Robert Rudnitsky, Michael Bartsch, Robert Full, Kellar Autumn, James Nelson, Jim Spudich, and Mark Cutkosky This work is funded by NSF (XYZ on a Chip) and ONR MURI (Biomimetic Robots).

  12. ExternE transport methodology for external cost evaluation of air pollution

    Jensen, S. S.; Berkowicz, R.; Brandt, J.;

    The report describes how the human exposure estimates based on NERI's human exposure modelling system (AirGIS) can improve the Danish data used for exposure factors in the ExternE Transport methodology. Initially, a brief description of the ExternE Tranport methodology is given and it is summarised...... how the methodology has been applied so far in a previous Danish study. Finally, results of a case study are reported. Exposure factors have been calculated for various urban categories in the Greater Copenhagen Area...

  13. Measuring the force ejecting DNA from phage

    Evilevitch, A; Knobler, C M; Gelbart, W M

    2004-01-01

    We discuss how a balance can be established between the force acting to eject DNA from viral capsids and the force resisting its entry into a colloidal suspension which mimics the host cell cytoplasm. The ejection force arises from the energy stored in the capsid as a consequence of the viral genome (double-stranded DNA) being strongly bent and crowded on itself. The resisting force is associated with the osmotic pressure exerted by the colloidal particles in the host solution. Indeed, recent experimental work has demonstrated that the extent of ejection can be progressively limited by increasing the external osmotic pressure; at a sufficiently high pressure the ejection is completely suppressed. We outline here a theoritical analysis that allows a determination of the internal (capsid) pressure by examining the different relations between force and pressure inside and outside the capsid, using the experimentally measured position of the force balance.

  14. Retrofitting Systems for External Walls

    Rose, Jørgen

    1997-01-01

    In this report, 9 different external and internal retrofitting systems are analyzed using numerical calculations. The analysis focuses on the thermal bridge effects in the different systems, and on this basis it is discussed whether internal or external retrofitting has the most advantages. The...... different systems are evaluated using 5 different types of existing walls....

  15. An overview of environmental externalities

    This paper describes the purpose of the conference on environmental externalities and provides illustrations and examples of incorporating these costs into the utility planning process. The topics of the paper include internalization, externalities, resistance to incorporation, reasons why they should be incorporated, and mechanisms for incorporation

  16. External coating of colonic anastomoses

    Pommergaard, Hans-Christian; Achiam, Michael Patrick; Rosenberg, Jacob

    2012-01-01

    Colon anastomotic leakage remains both a frequent and serious complication in gastrointestinal surgery. External coating of colonic anastomoses has been proposed as a means to lower the rate of this complication. The aim of this review was to evaluate existing studies on external coating of colonic...

  17. Effect of various periodic forces on Duffing oscillator

    V Ravichandran; V Chinnathambi; S Rajasekar

    2006-08-01

    Bifurcations and chaos in the ubiquitous Duffing oscillator equation with different external periodic forces are studied numerically. The external periodic forces considered are sine wave, square wave, rectified sine wave, symmetric saw-tooth wave, asymmetric saw-tooth wave, rectangular wave with amplitude-dependent width and modulus of sine wave. Period doubling bifurcations, chaos, intermittency, periodic windows and reverse period doubling bifurcations are found to occur due to the applied forces. A comparative study of the effect of various forces is performed.

  18. Utility planning and evaluating environmental externalities

    This discussion of environmental externalities in utility planning is divided into three parts. First, the pending Clean Air Act (CAA) Amendments contain market-based control provisions that internalize damage associated with SO2 and NOx air pollution. The amendments pose new challenges and risks for utility planners. The paper highlights several issues that have not received much attention. In particular, the need for short-term and long-term emissions allowance markets and the concept of emissions pooling. Conceptually, emissions pools would be similar to utility power pools. Since a utility may not know if it will exceed its annual emissions allowance until well into the year, a procedure for obtaining additional allowances could have value. Second, state regulators are taking a hard look at incorporating environmental externalities in the least-cost planning process. Generic methods available for incorporating externalities in the planning process are discussed. Third, a number of recent studies have referred to approaches for the direct valuation of externalities. Several of the more commonly used methods are described. Tables are presented that outline the applicability of the techniques and their strengths and weaknesses

  19. Current Status of Protein Force Fields for Molecular Dynamics

    Lopes, Pedro E.M.; Guvench, Olgun

    2015-01-01

    Summary The current status of classical force fields for proteins is reviewed. These include additive force fields as well as the latest developments in the Drude and AMOEBA polarizable force fields. Parametrization strategies developed specifically for the Drude force field are described and compared with the additive CHARMM36 force field. Results from molecular simulations of proteins and small peptides are summarized to illustrate the performance of the Drude and AMOEBA force fields. PMID:25330958

  20. Current Status of Protein Force Fields for Molecular Dynamics

    Lopes, Pedro E. M.; Guvench, Olgun; MacKerell, Alexander D.

    2015-01-01

    The current status of classical force fields for proteins is reviewed. These include additive force fields as well as the latest developments in the Drude and AMOEBA polarizable force fields. Parametrization strategies developed specifically for the Drude force field are described and compared with the additive CHARMM36 force field. Results from molecular simulations of proteins and small peptides are summarized to illustrate the performance of the Drude and AMOEBA force fields.

  1. Current status of protein force fields for molecular dynamics simulations.

    Lopes, Pedro E M; Guvench, Olgun; MacKerell, Alexander D

    2015-01-01

    The current status of classical force fields for proteins is reviewed. These include additive force fields as well as the latest developments in the Drude and AMOEBA polarizable force fields. Parametrization strategies developed specifically for the Drude force field are described and compared with the additive CHARMM36 force field. Results from molecular simulations of proteins and small peptides are summarized to illustrate the performance of the Drude and AMOEBA force fields. PMID:25330958

  2. The Labour Market as the Driving Force of Belgian Higher Education.

    Wielemans, Willy

    1988-01-01

    An examination of internal and external forces on Belgian higher education suggests that the system is too closely controlled by economic and political forces in the labor market, which threatens to distort university life and higher education in general. (MSE)

  3. Gap Task Force

    Lissuaer, D

    One of the more congested areas in the ATLAS detector is the GAP region (the area between the Barrel Calorimeter and the End Cap calorimeter) where Inner Detector services, LAr Services and some Tile services all must co-habitat in a very limited area. It has been clear for some time that the space in the GAP region is not sufficient to accommodate all that is needed. In the last few month additional problems of routing all the services to Z=0 have been encountered due to the very limited space between the Tile Calorimeter and the first layer of Muon chambers. The Technical Management Board (TMB) and the Executive Board (EB) decided in the middle of March to establish a Task Force to look at this problem and come up with a solution within well-specified guidelines. The task force consisted of experts from the ID, Muon, Liquid Argon and Tile systems in addition to experts from the Technical Coordination team and the Physics coordinator. The task force held many meetings and in general there were some very l...

  4. Hip External Rotator Strength Is Associated With Better Dynamic Control of the Lower Extremity During Landing Tasks.

    Malloy, Philip J; Morgan, Alexander M; Meinerz, Carolyn M; Geiser, Christopher F; Kipp, Kristof

    2016-01-01

    The purpose of this study was to determine the association between hip strength and lower extremity kinematics and kinetics during unanticipated single-leg landing and cutting tasks in collegiate female soccer players. Twenty-three National Collegiate Athletic Association division I female soccer players were recruited for strength testing and biomechanical analysis. Maximal isometric hip abduction and external rotation strength were measured using a hand-held dynamometer and expressed as muscle torque (force × femoral length) and normalized to body weight. Three-dimensional lower extremity kinematics and kinetics were assessed with motion analysis and force plates, and an inverse dynamics approach was used to calculate net internal joint moments that were normalized to body weight. Greater hip external rotator strength was significantly associated with greater peak hip external rotation moments (r = 0.47; p = 0.021), greater peak knee internal rotation moments (r = 0.41; p = 0.048), greater hip frontal plane excursion (r = 0.49; p = 0.017), and less knee transverse plane excursion (r = -0.56; p = 0.004) during unanticipated single-leg landing and cutting tasks. In addition, a statistical trend was detected between hip external rotator strength and peak hip frontal plane moments (r = 0.39; p = 0.06). The results suggest that females with greater hip external rotator strength demonstrate better dynamic control of the lower extremity during unanticipated single-leg landing and cutting tasks and provide further support for the link between hip strength and lower extremity landing mechanics. PMID:26110347

  5. Lie-admissible structure of Hamilton's original equations with external terms

    As a necessary additional step in preparation of our operator studies of closed nonhamiltonian systems, in this note we consider the algebraic structure of the original equations proposed by Lagrange and Hamilton, those with external terms representing precisely the contact nonpotential forces of the interior dynamical problem. We show that the brackets of the theory violate the conditions to characterize any algebra. Nevertheless, when properly written, they characterize a covering of the Lie-isotopic algebras called Lie-admissible algebras. It is indicated that a similar occurrence exists for conventional operator treatments, e.g. for nonconservative nuclear cases characterized by nonhermitean Hamiltonians. This occurrence then prevents a rigorous treatment of basic notions, such as that of angular momentum and spin spin, which are centrally dependent on the existence of a consistent algebraic structure. The emergence of the Lie-admissible algebras is therefore expected to be unavoidable for any rigorous operator treatment of open systems with nonlinear, nonlocal and nonhamiltonian external forces. (author). 14 refs, 1 fig

  6. Calculus of axial force in a mechanism using Lagrange equations

    Thien Van NGUYEN

    2016-06-01

    Full Text Available Lagrange equations are used to study the motion of a system under the action of known external forces. Besides, based on these equations we can determine the internal force in an arbitrary element of the mechanism acting by active force. If an internal force has to be found, a supplementary mobility related to it is considered in the system. The corresponding internal force for new mobility is found for null values of mobility and of its first and second derivatives. Also the determination of the axial force in the connecting rod of the slider-crank mechanism is presented in this paper as an illustration of this method.

  7. Handbook of Molecular Force Spectroscopy

    Noy, Aleksandr

    2008-01-01

    "...Noy's Handbook of Molecular Force Spectroscopy is both a timely and useful summary of fundamental aspects of molecular force spectroscopy, and I believe it would make a worthwhile addition to any good scientific library. New research groups that are entering this field would be well advisedto study this handbook in detail before venturing into the exciting and challenging world of molecular force spectroscopy." Matthew F. Paige, University of Saskatchewan, Journal of the American Chemical Society Modern materials science and biophysics are increasingly focused on studying and controlling intermolecular interactions on the single-molecule level. Molecular force spectroscopy was developed in the past decade as the result of several unprecedented advances in the capabilities of modern scientific instrumentation, and defines a number of techniques that use mechanical force measurements to study interactions between single molecules and molecular assemblies in chemical and biological systems. Examples of these...

  8. External costs related to power production technologies. ExternE national implementation for Denmark

    The objective of the ExternE National Implementation project has been to establish a comprehensive and comparable set of data on externalities of power generation for all EU member states and Norway. The tasks include the application of the ExternE methodology to the most important fuel cycles for each country as well as to update the already existing results; to aggregate these site- and technology-specific results to more general figures. The current report covers the results of the national implementation for Denmark. Three different fuel cycles have been chosen as case studies. These are fuel cycles for an offshore wind farm and a wind farm on land, a decentralised CHP plant based on natural gas and a decentralised CHP plant based on biogas. The report covers all the details of the application of the methodology to these fuel cycles aggregation to a national level. (au) EU-JOULE 3. 59 tabs., 25 ills., 61 refs

  9. External costs related to power production technologies. ExternE national implementation for Denmark

    Schleisner, L.; Sieverts Nielsen, P.

    1997-12-01

    The objective of the ExternE National Implementation project has been to establish a comprehensive and comparable set of data on externalities of power generation for all EU member states and Norway. The tasks include the application of the ExternE methodology to the most important fuel cycles for each country as well as to update the already existing results; to aggregate these site- and technology-specific results to more general figures. The current report covers the results of the national implementation for Denmark. Three different fuel cycles have been chosen as case studies. These are fuel cycles for an offshore wind farm and a wind farm on land, a decentralised CHP plant based on natural gas and a decentralised CHP plant based on biogas. The report covers all the details of the application of the methodology to these fuel cycles aggregation to a national level. (au) EU-JOULE 3. 59 tabs., 25 ills., 61 refs.

  10. Guidance for External Events Analysis

    This Guidance for External Events Analysis was developed under a contract with the Nordic PSA Group, and aims at creating a common framework for analysis of external events as part of a nuclear power plant Probabilistic Safety Assessment. Thus, the purpose of this Guidance is to constitute a common methodological guidance for the analysis of external events at Nordic nuclear power plants. This will make it possible for the utilities to perform these analyses in a cost-efficient way, assuring simultaneously the quality of the analyses. The Guidance is meant to clarify the scope of the analysis of external events, to provide guidance for the performance of the analysis, and to help in defining, subcontracting and reviewing the work. The analysis procedure includes four phases, addressing project planning, identification of external events, screening of events, and probabilistic analysis. The aim is first to do as complete an identification of potential single and combined external events as possible. Thereafter, as many external events as possible are screened out as early as possible. The screening capability is increased during the project, using the continuously acquired information on the events and on their effects on the plant

  11. Measuring Agglomeration Forces in a Financial Center

    Bourgain, Arnaud; Pieretti, Patrice

    2006-01-01

    Basing on Scitovsky's (1954) definition of external economies and applying the method of Caballero and Lyons (1990) to macro data of Luxembourg services industry, we find significant agglomeration forces between financial intermediaries (downstream industry) on the one hand and business services and computer industry (upstream industries) on the other.

  12. ESTIMATION OF EXTERNAL COSTS OF ELECTRICITY GENERATION USING EXTERNE MODEL

    Molnar, Sandor; Debrecin, N.; Kovacevic, T; Molnar, Melinda

    2008-01-01

    The external costs of electricity generation can be characterised by the resulting social and environmental impacts. The most significant impacts are the air pollutions impact on health, built in environment, crops, forests, agricultural areas and on global warming. The primary impact considered is the air pollution’s effect on human health. The monetised value of the health impact, the external costs are calculated for two regional coal power plants, the effects are examined on the EU level ...

  13. Cosmological accretion disks via external radiation drag

    Fukue, Jun; Umemura, Masayuki

    1994-02-01

    Accretion disks as well as disk accretion driven by external radiation drag are presented under a steady approximation in the cases of the point-mass potential and of the dark-matter potential. We assume that the external drag force can be expressed as -beta V, where beta is a constant coefficient and V the velocity vector. When the gravitational potential is given by a central point-mass M, we find, in a cold regime where the pressure force is neglected, steady solutions such that the infalling velocity Vr is expressed as Vr = -beta r far from the center and as Vr = 2 beta r near the center, where r is the distance from the center, while the rotation velocity Vphi is constant far from the center and almost Keplerian (i.e., Vphi = square root of (GM/r)) near the center. In a warm regime, where the effect of the gas pressure is taken into account, a transonic solution is found, where the flow accretes supersonically far from the center, passes a sonic point, and eventually becomes subsonic, but rotating in a nearly Keplerian orbit. When the dark matter exerts a gravitational force, which is assumed to be -r((omegaDM)2) (omegaDM = const.), we find steady analytical solutions in the cold regime such that Vr = -(beta/2)r and Vphi = r(square root of (((omegaDM)2) - ((beta2)/4))). The effect of the gas pressure is also discussed. Such accretion disks, where the angular momentum is removed via an external radiative drag proportional to the velocity (beta disk), are possible in the post-recombination epoch during the early universe. Shortly after the cosmological recombination era, when the radiation density of the cosmic background radiation (CBR) was sufficiently high, the gas could lose its angular momentum efficiently through Compton drag with the CBR and, consequently, form cosmological accretion disks which evolve into primordial active galactic nuclei (proto-quasars). In a dark matter-dominated universe, the disk gas would initially accrete in the dark

  14. External effects in Swiss hydropower

    The article discusses the external costs and benefits of hydropower that are not internalised in normal book-keeping. Several negative and positive effects are discussed. The results of a study that addressed the difficult task of quantifying these external effects are presented. An assessment of the results gained shows that difficulties are to be met regarding system limits, methods of expressing the effects in monetary terms and ethical factors. The report also examines the consideration of external effects as a correction factor for falsified market prices for electricity

  15. Radiometric force in dusty plasmas

    Ignatov, A M

    2000-01-01

    A radiofrequency glow discharge plasma, which is polluted with a certain number of dusty grains, is studied. In addition to various dusty plasma phenomena, several specific colloidal effects should be considered. We focus on radiometric forces, which are caused by inhomogeneous temperature distribution. Aside from thermophoresis, the role of temperature distribution in dusty plasmas is an open question. It is shown that inhomogeneous heating of the grain by ion flows results in a new photophoresis like force, which is specific for dusty discharges. This radiometric force can be observable under conditions of recent microgravity experiments.

  16. Applications of external beam PIXE at RMIT

    Moser, M.; Bubb, I. F.; Johnston, P. N.; El Bouanani, M.; Stannard, W. B.; Short, R. C.

    1998-04-01

    The development of an external Proton Induced X-Ray Emission (PIXE) facility for the 1 MV Tandetron accelerator based at the Royal Melbourne Institute of Technology has enabled the analysis of artefacts from the Museum of Victoria. Analyses of antique bullets, Egyptian glass samples, an Egyptian wall paint fragment and pigments from soils have been carried out. The results from the analysis of antique bullets determined the composition of blue spots on one bullet and aided in the conservation process. External PIXE analysis of two Egyptian glass samples enabled the partial determination of the colouring transition metals. Analysis of an Egyptian wall paint fragment and pigments from soils originating from the archaeological excavation of the town of Ismant el-Kharab as part of the Dakhleh Oasis Project revealed the necessity to find additional pigments to enable identification of the geographical origin of the wall paint.

  17. Applications of external beam PIXE at RMIT

    The development of an external proton induced X-ray emission (PIXE) facility for the 1 MV tandetron accelerator based at Royal Melbourne institute of technology has enabled the analysis of artefacts from the Museum of Victoria. Analyses of antique bullets, Egyptian glass samples, an Egyptian wall paint fragment and pigments from soils have been carried out. The results from the analysis of antique bullets determined the composition of blue spots on one bullet and aided in the conservation process. External PIXE analysis of two Egyptian glass samples enabled the partial determination of the colouring transition metals. Analysis of an Egyptian wall paint fragment and pigments from soils originating from the archaeological excavation of the town of Ismant el-Kharab as part of the Dakhleh Oasis Project revealed the necessity to find additional pigments to enable identification of the geographical origin of the wall paint. (orig.)

  18. External doses from radioactive fallout. Dosimetry and levels

    Woehni, T.

    1995-12-31

    The design, manufacture and calibration of a TL-based dosemeter for measurement of low level external photon radiation are presented. The dosemeter is based on CaF{sub 2} with 2 mm brass filter for energy compensation. It is able to resolve a 8% dose increase relative to natural background radiation. With this dosemeter external dose measurements were made in 6 villages in a heavily contaminated region in Russia (Chernobyl fallout), in order to assess external doses to the population. The results were analyzed in the light of additional existing information on radioactive deposition, social habits, decontamination measures and other influencing technical and physical factors. The observed dose values were lower than theoretical estimates of external doses based on published values for external dose levels relative to the level of contamination. 84 refs., 7 figs., 5 tabs.

  19. External doses from radioactive fallout. Dosimetry and levels

    The design, manufacture and calibration of a TL-based dosemeter for measurement of low level external photon radiation are presented. The dosemeter is based on CaF2 with 2 mm brass filter for energy compensation. It is able to resolve a 8% dose increase relative to natural background radiation. With this dosemeter external dose measurements were made in 6 villages in a heavily contaminated region in Russia (Chernobyl fallout), in order to assess external doses to the population. The results were analyzed in the light of additional existing information on radioactive deposition, social habits, decontamination measures and other influencing technical and physical factors. The observed dose values were lower than theoretical estimates of external doses based on published values for external dose levels relative to the level of contamination. 84 refs., 7 figs., 5 tabs

  20. Environmental externalities related to power production on biogas and natural gas based on the EU ExternE methodology

    Nielsen, Per Sieverts; Ibsen, Liselotte Schleisner

    This paper assesses the environmental impacts and external costs from selected electricity generation systems in Denmark. The assessment is carried out as part of the ExternE National Implementation, which is the second phase of the ExternE project and involves case studies from all Western Europ...

  1. External proton and Li beams

    In the frame of a feasibility study to introduce proton therapy in Argentina in a collaborative agreement between the Physics and Radiobiology Departments of the National Atomic Energy Commission or Argentina and the Centre de Protontherapie de Orsay, France, external proton and Li beams were produced at the TANDAR accelerator in Buenos Aires. The specific aim of this work was to start radiobiology studies on cell cultures and small laboratory animals. In particular we seek to determine here the relative biological effectiveness, RBE, for proton and Li beams as a function of energy for different tumor and normal cell lines. The 24 MeV proton beam was diffused using a 25 μm gold foil and extracted through a Kapton window to obtain a homogeneous field (constant to 95%) of about 7 cm in diameter. Measurements were carried out with quasi-monoenergetic beams (of 20.2 ± 0.07 MeV, 2.9 ± 0.10 MeV y 1.5 ± 0.1 MeV for protons and 21.4 ± 0.4 MeV for Lithium). Proton fluence and Bragg peaks were measured. The dose delivered in each case was monitored on-line with a calibrated transmission ionization chamber. Three cell lines PDV, PDVC 57 and V 79 (as a reference) were irradiated with γ-rays, proton and lithium beams with linear energy transfer (LET) from 2 to 100 keV/μm. RBE values in the range of 1.2-5.9 were obtained. In addition preliminary studies on chromosomal aberrations and viability of alveolar macrophages were carried out. (author)

  2. External meeting: Geneva University

    2006-01-01

    Université de Genève Ecole de physique 24 quai Ernest Ansermet 1211 Genève 4 Tél : + 41 22 379 63 83 (secrétariat) Tél : + 41 22 379 62 56 (réception) Fax: + 41 22 379 69 22 Lundi 20 novembre 2006 COLLOQUIUM 17:00 - Auditoire Stückelberg Electrical correlation measurements in quantum nano-structures Dr. Stefan Oberholzer / Basel University Measuring the current-voltage characteristics of small conductors is widely used to characterize their electronic transport properties. In addition to such time-averaged measurements, correlation measurements between temporal fluctuations (noise) around the time-averaged mean current provide us with very important supplementary information about electrical transport. In this talk, I review our experimental work on shot noise, noise which originates from the granularity of charge and the diffraction of the electronic wave-function, and especially address the fundamental relation between electronic scattering experiments and the statistical properties of indist...

  3. External meeting: Geneva University

    2006-01-01

    Ecole de physique 24 quai Ernest Ansermet 1211 GENEVA 4 Tel: (022) 379 62 73 Fax: (022) 379 69 92 Monday 19 June 2006 17:00-Stückelberg Auditorium Quantum Optics and Quantum Information Processing with Superconducting Circuits Prof. A. Wallraff /ETH Zürich I will describe recent experiments with superconducting circuits in which we have demonstrated the coherent interaction of a two-level system and a single mode of a cavityfield. Such a feat was previously only realizable in atomic cavity quantum electrodynamics experiments. In our circuit we have generated coherent superpositions between asingle photon and a single superconducting qubit and have used photons to perform a quantum non-demolition measurement of the state of the qubit. This new regime ofmatter-light interaction in a circuit, allows us to both perform state of the art quantum optics experiments and to realize new elements for a quantum information processor. For additional information and publications please visit: http://www.solid.phys....

  4. Performance Targets and External Benchmarking

    Friis, Ivar; Hansen, Allan; Vámosi, Tamás S.

    Research on relative performance measures, transfer pricing, beyond budgeting initiatives, target costing, piece rates systems and value based management has for decades underlined the importance of external benchmarking in performance management. Research conceptualises external benchmarking as a...... market mechanism that can be brought inside the firm to provide incentives for continuous improvement and the development of competitive advances. However, whereas extant research primarily has focused on the importance and effects of using external benchmarks, less attention has been directed towards...... the conditions upon which the market mechanism is performing within organizations. This paper aims to contribute to research by providing more insight to the conditions for the use of external benchmarking as an element in performance management in organizations. Our study explores a particular type...

  5. Leveraging External Sources of Innovation

    West, Joel; Bogers, Marcel

    2014-01-01

    external innovations create value rather than how firms capture value from those innovations. Finally, the interaction phase considers both feedback for the linear process and reciprocal innovation processes such as cocreation, network collaboration, and community innovation. This review and synthesis......This paper reviews research on open innovation that considers how and why firms commercialize external sources of innovations. It examines both the “outside-in” and “coupled” modes of open innovation. From an analysis of prior research on how firms leverage external sources of innovation, it...... suggests a four-phase model in which a linear process—(1) obtaining, (2) integrating, and (3) commercializing external innovations—is combined with (4) interaction between the firm and its collaborators. This model is used to classify papers taken from the top 25 innovation journals, complemented by highly...

  6. External costs related to power production technologies. ExternE national implementation for Denmark

    Schleisner, L.; Sieverts Nielsen, P. [eds.

    1997-12-01

    The objective of the ExternE National Implementation project has been to establish a comprehensive and comparable set of data on externalities of power generation for all EU member states and Norway. The tasks include the application of the ExternE methodology to the most important fuel cycles for each country as well as to update the already existing results, to aggregate these site- and technology-specific results to more general figures. The current report covers the detailed information concerning the ExternE methodology. Importance is attached to the computer system used in the project and the assessment of air pollution effects on health, materials and ecological effects. Also the assessment of global warming damages are described. Finally the report covers the detailed information concerning the national implementation for Denmark for an offshore wind farm and a wind farm on land, a decentralised CHP plant based on natural gas and a decentralised CHP plant base on biogas. (au) EU-JOULE 3. 79 tabs., 11 ills., 201 refs.

  7. External costs related to power production technologies. ExternE national implementation for Denmark

    The objective of the ExternE National Implementation project has been to establish a comprehensive and comparable set of data on externalities of power generation for all EU member states and Norway. The tasks include the application of the ExternE methodology to the most important fuel cycles for each country as well as to update the already existing results, to aggregate these site- and technology-specific results to more general figures. The current report covers the detailed information concerning the ExternE methodology. Importance is attached to the computer system used in the project and the assessment of air pollution effects on health, materials and ecological effects. Also the assessment of global warming damages are described. Finally the report covers the detailed information concerning the national implementation for Denmark for an offshore wind farm and a wind farm on land, a decentralised CHP plant based on natural gas and a decentralised CHP plant base on biogas. (au) EU-JOULE 3. 79 tabs., 11 ills., 201 refs

  8. Axial force measurement for esophageal function testing.

    Gravesen, Flemming H; Funch-Jensen, Peter; Gregersen, Hans; Drewes, Asbjørn Mohr

    2009-01-14

    The esophagus serves to transport food and fluid from the pharynx to the stomach. Manometry has been the "golden standard" for the diagnosis of esophageal motility diseases for many decades. Hence, esophageal function is normally evaluated by means of manometry even though it reflects the squeeze force (force in radial direction) whereas the bolus moves along the length of esophagus in a distal direction. Force measurements in the longitudinal (axial) direction provide a more direct measure of esophageal transport function. The technique used to record axial force has developed from external force transducers over in-vivo strain gauges of various sizes to electrical impedance based measurements. The amplitude and duration of the axial force has been shown to be as reliable as manometry. Normal, as well as abnormal, manometric recordings occur with normal bolus transit, which have been documented using imaging modalities such as radiography and scintigraphy. This inconsistency using manometry has also been documented by axial force recordings. This underlines the lack of information when diagnostics are based on manometry alone. Increasing the volume of a bag mounted on a probe with combined axial force and manometry recordings showed that axial force amplitude increased by 130% in contrast to an increase of 30% using manometry. Using axial force in combination with manometry provides a more complete picture of esophageal motility, and the current paper outlines the advantages of using this method. PMID:19132762

  9. Axial force measurement for esophageal function testing

    Flemming H Gravesen; Peter Funch-Jensen; Hans Gregersen; Asbjφrn Mohr Drewes

    2009-01-01

    The esophagus serves to transport food and fluid from the pharynx to the stomach. Manometry has been the "golden standard" for the diagnosis of esophageal motility diseases for many decades. Hence, esophageal function is normally evaluated by means of manometry even though it reflects the squeeze force (force in radial direction) whereas the bolus moves along the length of esophagus in a distal direction. Force measurements in the longitudinal (axial) direction provide a more direct measure of esophageal transport function. The technique used to record axial force has developed from external force transducers over in-vivo strain gauges of various sizes to electrical impedance based measurements. The amplitude and duration of the axial force has been shown to be as reliable as manometry. Normal, as well as abnormal, manometric recordings occur with normal bolus transit, which have been documented using imaging modalities such as radiography and scintigraphy. This inconsistency using manometry has also been documented by axial force recordings. This underlines the lack of information when diagnostics are based on manometry alone. Increasing the volume of a bag mounted on a probe with combined axial force and manometry recordings showed that axial force amplitude increased by 130% in contrast to an increase of 30% using manometry. Using axial force in combination with manometry provides a more complete picture of esophageal motility, and the current paper outlines the advantages of using this method.

  10. External recruitment versus internal promotion

    Chan, William

    1996-01-01

    This article analyzes the choice between internal promotion and external recruitment within the framework of an economic contest. Opening up the competition for a position to external candidates reduces the chance of promotion for existing workers and, therefore, their incentive to work. Increasing the prize for winning can maintain incentives but is limited by moral hazard and potentially disruptive office politics. Alternatively, a competitive handicap can be awarded to existing workers to ...

  11. Consumption externalities, coordination and advertising

    Pastine, Tuvana; Pastine, Ivan

    2001-01-01

    The aim of this Paper is to demonstrate that advertising can have an important function in markets with consumption externalities, apart from its persuasive and informative roles. We show that advertising may function as a device to coordinate consumer expectations of the purchasing decisions of other consumers in markets with consumption externalities. The implications of advertising as a coordinating device are examined in the pricing and advertising decisions of firms interacting strategic...

  12. Comsumption Externalities, Coordination, and Advertising

    Ivan Pastine; Tuvana Pastine

    2002-01-01

    The aim of this article is to demonstrate that advertising can have an important function in markets with consumption externalities apart from its persuasive and informative roles. We show that advertising may function as a device to coordinate consumer expectations of the purchasing decisions of other consumers in markets with consumption externalities. The implications of advertising as a coordinating device are examined in the pricing and advertising decisions of firms interacting strategi...

  13. Epidemic Spreading with External Agents

    Banerjee, Siddhartha; Gopalan, Aditya; Das, Abhik Kumar; Shakkottai, Sanjay

    2012-01-01

    We study epidemic spreading processes in large networks, when the spread is assisted by a small number of external agents: infection sources with bounded spreading power, but whose movement is unrestricted vis-\\`a-vis the underlying network topology. For networks which are `spatially constrained', we show that the spread of infection can be significantly speeded up even by a few such external agents infecting randomly. Moreover, for general networks, we derive upper-bounds on the order of the...

  14. Irrigation externalities: pricing and charges

    Gavan Dwyer; Robert Douglas; Deb Peterson; Jo Chong; Kate Maddern

    2006-01-01

    The Productivity Commission Staff Working Paper ‘Irrigation externalities: pricing and charges. by Gavan Dwyer, Robert Douglas, Deb Peterson, Jo Chong and Kate Maddern was released on 14 March 2006. The paper discusses the nature and causes of environmental change related to rural water use, and provides a taxonomy of the many diverse types. It also examines the issues surrounding possible charges on water use for water related externalities. There have been few attempts by water utilities to...

  15. Myiasis in female external genitalia

    Usha Kataria

    2013-01-01

    Full Text Available Myiasis is derived from the Greek word-"Myia", meaning "fly". The term was first introduced by Hope in 1840 and refers to the infestation of human beings with dipterous larvae (maggots. Presence of maggots on exposed parts is already known, but on covered parts like external genitalia it is very rare. We hereby describe a case of young unmarried female who presented with multiple sinuses over external genitalia along with maggots coming out of it.

  16. Myiasis in female external genitalia

    Usha Kataria; Sunita Siwach; Sanjeev Gupta

    2013-01-01

    Myiasis is derived from the Greek word-"Myia", meaning "fly". The term was first introduced by Hope in 1840 and refers to the infestation of human beings with dipterous larvae (maggots). Presence of maggots on exposed parts is already known, but on covered parts like external genitalia it is very rare. We hereby describe a case of young unmarried female who presented with multiple sinuses over external genitalia along with maggots coming out of it.

  17. Urban Sprawl and Transportation Externalities

    Randall G. Holcombe; Williams, DeEdgra W.

    2010-01-01

    One argument in support of minimizing urban sprawl is that sprawl creates transportation externalities. A problem with empirically examining the relationship between sprawl and transportation externalities is that sprawl is a difficult concept to quantify. This paper uses a measure of sprawl designed by Ewing, Pendall, and Chen (2002) to examine the relationship between sprawl and commute times, automobile ownership, miles driven, fatal auto accidents, air pollution, and highway expenditures....

  18. External photon beams: Physical aspects

    Radiotherapy procedures fall into two main categories: external beam radiotherapy and brachytherapy. In external beam radiotherapy the radiation source is at a certain distance from the patient and the target within the patient is irradiated with an external radiation beam. In brachytherapy (see Chapter 13) radiation sources are placed directly into the target volume (intracavitary or interstitial brachytherapy) or on to a target (surface mould or intraoperative radiotherapy). Most external beam radiotherapy is carried out with photon beams, some with electron beams and a very small fraction with more exotic particles such as protons, heavier ions or neutrons. This chapter deals with external photon beam radiotherapy. Photon external beams are all characterized by the same physical parameters, but fall into various categories depending on their origin, means of production and energy. There are two origins of photon beams: g rays, which originate from radioactive nuclei, and X rays, which originate in a target bombarded with energetic electrons. The X rays from a target consist of bremsstrahlung photons and characteristic photons. X rays are produced either in an X ray tube (superficial or orthovoltage X rays) or in a linac (megavoltage X rays)

  19. An experimental study on feasibility of ex-vessel cooling through the external guide vessel

    This paper presents the results of a series of experiments for assessing the efficacy of ex-vessel cooling through the external guide vessel during a severe accident. Four tests were performed in the LAVA test facility at KAERI, varying the boundary conditions at the outer surface of the vessel. The first test was a dry condition test conducted without cooling the outside of the vessel. On the other hand, in the second test, the cooling of the vessel surface was produced by gravity-driven forced injection of water along the annular gap of 25 mm between the vessel and the external guide vessel. Water flow rate was about 0.85 kg/s and total mass of available water was 300 kg. For the evaluation of the water flow rate effect, the third test was performed with a pool type cooling in the annulus without any circulation of water. These two external cooling tests were performed under elevated pressure of about 1.6 MPa. Finally, the fourth test was conducted under atmospheric pressure to evaluate the effect of system pressure on boiling heat transfer characteristics. In the dry test and the pool type ex-vessel cooling test performed under atmospheric pressure, the vessel was failed by a melt penetration at about 40 degree upper position from the vessel bottom, which is coincident with the boundary of the Al2O3/Fe melt separated layers. On the other hand, in both of the ex-vessel cooling tests conducted under elevated pressure of about 1.6 MPa, the vessel didn't fail. Compared with the pool boiling test, the vessel experienced effective cooling due to the inlet flow in the forced flow test. Synthesized the results of the tests, it was shown that the heat removal with ex-vessel cooling through the guide vessel is feasible, but the additional evaluations should be performed to guarantee enough thermal margin. (author)

  20. Wave Forces on Offshore Windturbine Foundations

    Andersen, Thomas Lykke; Frigaard, Peter

    The present paper is a supplement to the report by Juul Larsen and Frigaard. It contains some additional quality control to the force measurements performed by Juul Larsen and Frigaard.......The present paper is a supplement to the report by Juul Larsen and Frigaard. It contains some additional quality control to the force measurements performed by Juul Larsen and Frigaard....

  1. Thought Experiments on Gravitational Forces

    Lynden-Bell, Donald

    2013-01-01

    Large contributions to the near closure of the Universe and to the acceleration of its expansion are due to the gravitation of components of the stress-energy tensor other than its mass density. To familiarise astronomers with the gravitation of these components we conduct thought experiments on gravity, analogous to the real experiments that our forebears conducted on electricity. By analogy to the forces due to electric currents we investigate the gravitational forces due to the flows of momentum, angular momentum, and energy along a cylinder. Under tension the gravity of the cylinder decreases but the 'closure' of the 3-space around it increases. When the cylinder carries a torque the flow of angular momentum along it leads to a novel helical interpretation of Levi-Civita's external metric and a novel relativistic effect. Energy currents give gravomagnetic effects in which parallel currents repel and antiparallel currents attract, though such effects must be added to those of static gravity. The gravity of...

  2. Implementation of the Additional Protocol in Japan

    The Additional Protocol between Japan and the IAEA entered into force in December 1999. To come into force a series of implementation trials of Additional Protocol was carried out at two Japanese representative nuclear research centers, i.e. Tokai Research Establishment of Japan Atomic Energy Research Institute (JAERI) and Oarai Engineering Center of Japan Nuclear Fuel Cycle Development Institute (JNC). These trials were proposed by Japan and were conducted in cooperation with the IAEA Secretariat. In addition, Japan amended 'the Law for the Regulation of Reactors etc.', to collect adequate information to submit to the IAEA, to arrange the surrounding for the complementary access, etc. In addition, Japan Submitted the Initial Declaration of the Additional Protocol within 180 days of the entry into force of the Protocol, in the middle of June, 2000

  3. External Costs Related to Power Production Technologies

    Ibsen, Liselotte Schleisner; Nielsen, Per Sieverts

    1997-01-01

    The European Commission has launched a major study project, ExternE, to develop a methodology to quantify externalities. A “National Implementation Phase”, was started under the Joule II programme with the purpose of implementing the ExternE methodology in all member states. The main objective of...

  4. Force and torque of an electromagnetically levitated metal sphere

    Lohoefer, G.

    1993-09-01

    The Lorentz force and torque exerted on an electrically conducting sphere exposed to an external, time-varying magnetic field are analytically calculated. The external magnetic field is generated by a set of sinusoidally alternating, but otherwise arbitrary, current density fields of different frequencies and phases. Expressions for the force and torque in a laboratory frame of reference, which is more convenient for application, are also given. Finally, the special cases of rotational and mirror-symmetric external current density fields are treated in more detail.

  5. Containment atmosphere response to external sprays

    The application of external sprays to a containment steel shell can be an effective energy removal method and has been proposed in the passive AP-600 design. Reduction of the steel shell temperature in contact with the containment atmosphere enhances both heat and mass transfer driving forces. Large scale experimental data in this area is scarce, therefore the measurements obtained from the E series tests conducted at the German HDR facility deserve special attention. These long term tests simulated various severe accident conditions, including external spraying of the hemispherical steel shell. This investigation focuses upon the integral response of the HDR containment atmosphere during spray periods and upon methods by which lumped parameter system codes, like CONTAIN, model the underlying condensation phenomena. Increases in spray water flowrates above a minimum value were ineffective at improving containment pressure reduction since the limiting resistance for energy transfer lies in the noncondensable-vapor boundary layer at the inner condensing surface. The spray created an unstable condition by cooling the upper layers of a heated atmosphere and thus inducing global natural circulation flows in the facility and subsequently, abrupt changes in lighter-than-air noncondensable (J2/He) concentrations. Modeling results using the CONTAIN code are outlined and code limitations are delineated

  6. Containment atmosphere response to external sprays

    Green, J.; Almenas, K. [Univ. of Maryland, College Park, MD (United States)

    1995-09-01

    The application of external sprays to a containment steel shell can be an effective energy removal method and has been proposed in the passive AP-600 design. Reduction of the steel shell temperature in contact with the containment atmosphere enhances both heat and mass transfer driving forces. Large scale experimental data in this area is scarce, therefore the measurements obtained from the E series tests conducted at the German HDR facility deserve special attention. These long term tests simulated various severe accident conditions, including external spraying of the hemispherical steel shell. This investigation focuses upon the integral response of the HDR containment atmosphere during spray periods and upon methods by which lumped parameter system codes, like CONTAIN, model the underlying condensation phenomena. Increases in spray water flowrates above a minimum value were ineffective at improving containment pressure reduction since the limiting resistance for energy transfer lies in the noncondensable-vapor boundary layer at the inner condensing surface. The spray created an unstable condition by cooling the upper layers of a heated atmosphere and thus inducing global natural circulation flows in the facility and subsequently, abrupt changes in lighter-than-air noncondensable (J{sub 2}/He) concentrations. Modeling results using the CONTAIN code are outlined and code limitations are delineated.

  7. Hexapod External Fixation of Tibia Fractures in Children.

    Iobst, Christopher A

    2016-06-01

    Most tibia fractures in children can be treated nonoperatively. For fractures that do require surgery, however, the most common methods of management include plating or flexible nail insertion. Some fracture patterns, such as periphyseal fractures, fractures with bone and/or soft tissue loss, or fractures with delayed presentation, are not easily amenable to these techniques. Hexapod external fixators are especially helpful in these difficult cases. The purpose of this review is to discuss the principles of performing hexapod circular external fixation applied to pediatric tibia fractures. Some of the additional capabilities of the hexapod external fixator will also be highlighted. PMID:27078228

  8. Multipurpose external fixator for intraarticular fracture of distal radius.

    Siripakarn, Yongyuth; Siripakarn, Zongyuti

    2010-12-01

    Fracture of distal radius is one of a complicated injury which can be difficult in reduction and maintaining its alignment and may result in malunion and shortening following a variety of fixation. Since Anderson's and O'neil described the use of sustain traction by extraskeletal device anchored to the radius and the first metacarpal of the hand. Vidal et al [1979] demonstrated that the ligamentotaxis could be used to reduce the fracture around the wrist, ankle, hip and knee. The external fixation frame can maintain radial length and inclination by the pullout force from the radial styloid. External fixation is useful for management of complex intraarticular fracture of distal radius. There are few types of commercially available fixator. It is important to use one that allow versatility and follow biomechanic principles of ligamentotaxis, which can be used to reduce the severe comminution and the most difficult fracture by distraction and stabilization effectively. The ideal characteristic of the external fixation are: Telescoping connecting frame fixed externally compose of two joints which can be easily adjust in any direction, two pins clamp connected to the external connecting rod. Our TU Multipurpose external fixator can be designed as a multiplana, can be used as a bridge or non bridge fixation, and can be adjusted to any direction which require for the treatment of distal radius fracture. It is differed to other commercially available devices. PMID:21294433

  9. Origin of Confining Force

    Cooper, Patrick

    2015-01-01

    In this article we present exact calculations that substantiate a clear picture relating the confining force of QCD to the zero-modes of the Faddeev-Popov (FP) operator $\\mathcal{M}(A) = - \\partial \\cdot D(A)$. This is done in two steps. First we calculate the spectral decomposition of the FP operator and show that the ghost propagator $\\mathcal{G}(k; A) = \\langle \\vec{k}| \\mathcal{M}^{-1}(A) | \\vec{k} \\rangle$ in an external gauge potential $A$ is enhanced at low $k$ in Fourier space for configurations $A$ on the Gribov horizon. This results from the new formula in the low-$k$ regime $\\mathcal{G}^{ab}(k,A) = \\delta^{ab} \\lambda_{|\\vec{k}|}^{-1}(gA)$, where $\\lambda_{|\\vec{k}|}(gA)$ is the eigenvalue of the FP operator that emerges from $\\lambda_{|\\vec{k}|}(0) = \\vec{k}^2$ at $A$ = 0. Next we derive a strict inequality signaling the divergence of the color-Coulomb potential at low momentum $k$ namely, $\\widetilde{\\mathcal{V}}(k) \\geq k^2 G^2(k)$ for $k \\to 0$, where $\\widetilde{\\mathcal{V}}(k)$ is the Fourier...

  10. Casimir forces and geometry

    Casimir interactions are interactions induced by quantum vacuum fluctuations and thermal fluctuations of the electromagnetic field. Using a path integral quantization for the gauge field, an effective Gaussian action will be derived which is the starting point to compute Casimir forces between macroscopic objects analytically and numerically. No assumptions about the independence of the material and shape dependent contributions to the interaction are made. We study the limit of flat surfaces in further detail and obtain a concise derivation of Lifshitz' theory of molecular forces. For the case of ideally conducting boundaries, the Gaussian action will be calculated explicitly. Both limiting cases are also discussed within the framework of a scalar field quantization approach, which is applicable for translationally invariant geometries. We develop a non-perturbative approach to calculate the Casimir interaction from the Gaussian action for periodically deformed and ideally conducting objects numerically. The obtained results reveal two different scaling regimes for the Casimir force as a function of the distance between the objects, their deformation wavelength and -amplitude. The results confirm that the interaction is non-additive, especially in the presence of strong geometric deformations. Furthermore, the numerical approach is extended to calculate lateral Casimir forces. The results are consistent with the results of the proximity-force approximation for large deformation wavelengths. A qualitatively different behaviour between the normal and lateral force is revealed. We also establish a relation between the boundary induced change of the of the density of states for the scalar Helmholtz equation and the Casimir interaction using the path integral method. For statically deformed boundaries, this relation can be expressed as a novel trace formula, which is formally similar to the so-called Krein-Friedel-Lloyd formula. While the latter formula describes the

  11. Engineering Strategies and Methods for Avoiding Air-Quality Externalities: Dispersion Modeling, Home Energy Conservation, and Scenario Planning

    Knox, Andrew James

    Energy conservation can improve air quality by reducing emissions from fuel combustion. The human health value retained through better air quality can then offset the cost of energy conservation. Through this thesis' innovative yet widely-accessible combination of air pollution dispersion modeling and atmospheric chemistry, it is estimated that the health value retained by avoiding emissions from Ontario's former coal-fired generating stations is 5.74/MWh (using an upper-bound value of 265,000 per year of life lost). This value is combined with energy modeling of homes in the first-ever assessment of the air-quality health benefits of low-energy buildings. It is shown that avoided health damages can equal 7% of additional construction costs of energy efficient buildings in Ontario. At 7%, health savings are a significant item in the cost analysis of efficient buildings. Looking to energy efficiency in the context of likely future low-resource natural gas scenarios, building efficient buildings today is shown to be more economically efficient than any building retrofit option. Considering future natural gas scarcity in the context of Ontario's Long-Term Energy Plan reveals that Ontario may be forced to return to coal-fired electricity. Projected coal use would result in externalities greater than $600 million/year; 80% more than air-quality externalities from Ontario's electricity in 1985. Radically aggressive investment in electricity conservation (75% reduction per capita by 2075) is one promising path forward that keeps air-quality externalities below 1985 levels. Non-health externalities are an additional concern, the quantification, and ultimately monetization, of which could be practical using emerging air pollution monitoring technologies. Energy, conservation, energy planning, and energy's externalities form a complex situation in which today's decisions are critical to a successful future. It is clear that reducing the demand for energy is essential and

  12. Strategic offloading of delayed intentions into the external environment.

    Gilbert, S. J.

    2014-01-01

    In everyday life, we often use external artefacts such as diaries to help us remember intended behaviours. In addition, we commonly manipulate our environment, for example by placing reminders in noticeable places. Yet strategic offloading of intentions to the external environment is not typically permitted in laboratory tasks examining memory for delayed intentions. What factors influence our use of such strategies, and what behavioural consequences do they have? This article describes four ...

  13. iCub Whole-body Control through Force Regulation on Rigid Noncoplanar Contacts

    Francesco eNori

    2015-03-01

    Full Text Available This paper details the implementation on the humanoid robot iCub of state-of-the-art algorithms for whole-body control. We regulate the forces between the robot and its surrounding environment to stabilize a desired robot posture. We assume that the forces and torques are exerted on rigid contacts. The validity of this assumption is guaranteed by constraining the contact forces and torques, e.g. the contact forces must belong to the associated friction cones. The implementation of this control strategy requires to estimate the external forces acting on the robot, and the internal joint torques. We then detail algorithms to obtain these estimations when using a robot with an iCub-like sensor set, i.e. distributed six-axis force-torque sensors and whole-body tactile sensors. A general theory for identifying the robot inertial parameters is also presented. From an actuation standpoint, we show how to implement a joint torque control in the case of DC brushless motors. In addition, the coupling mechanism of the iCub torso is investigated. The soundness of the entire control architecture is validated in a real scenario involving the robot iCub balancing and making contacts at both arms.

  14. Force control for mechanoinduction of impedance variation in cellular organisms

    Constantly exposed to various forms of mechanical forces inherent in their physical environment (such as gravity, stress induced by fluid flow or cell–cell interactions, etc), cellular organisms sense such forces and convert them into biochemical signals through the processes of mechanosensing and mechanotransduction that eventually lead to biological changes. The effect of external forces on the internal structures and activities in a cellular organism may manifest in changes its physical properties, such as impedance. Studying variation in the impedance of a cellular organism induced by the application of an external mechanical force represents a meaningful endeavor (from a biosystems perspective) in exploring the complex mechanosensing and mechanotransduction mechanisms that govern the behavior of a cellular organism under the influence of external mechanical stimuli. In this paper we describe the development of an explicit force-feedback control system for exerting an indentation force on a cellular organism while simultaneously measuring its impedance. To demonstrate the effectiveness of this force-control system, we have conducted experiments using zebrafish embryos as a test model of a cellular organism. We report experimental results demonstrating that the application of a properly controlled external force leads to a significant change in the impedance of a zebrafish embryo. These results offer support for a plausible explanation that activities of pore canals in the chorion are responsible for the observed change in impedance.

  15. Quantifying Interparticle Forces and Heterogeneity in 3D Granular Materials.

    Hurley, R C; Hall, S A; Andrade, J E; Wright, J

    2016-08-26

    Interparticle forces in granular materials are intimately linked to mechanical properties and are known to self-organize into heterogeneous structures, or force chains, under external load. Despite progress in understanding the statistics and spatial distribution of interparticle forces in recent decades, a systematic method for measuring forces in opaque, three-dimensional (3D), frictional, stiff granular media has yet to emerge. In this Letter, we present results from an experiment that combines 3D x-ray diffraction, x-ray tomography, and a numerical force inference technique to quantify interparticle forces and their heterogeneity in an assembly of quartz grains undergoing a one-dimensional compression cycle. Forces exhibit an exponential decay above the mean and partition into strong and weak networks. We find a surprising inverse relationship between macroscopic load and the heterogeneity of interparticle forces, despite the clear emergence of two force chains that span the system. PMID:27610890

  16. Relationship between Individual External Doses, Ambient Dose Rates and Individuals’ Activity-Patterns in Affected Areas in Fukushima following the Fukushima Daiichi Nuclear Power Plant Accident

    Kurosawa, Tadahiro; Yasutaka, Tetsuo; Ishii, Hideki

    2016-01-01

    The accident at Fukushima Daiichi Nuclear Power Plant on March 11, 2011, released radioactive material into the atmosphere and contaminated the land in Fukushima and several neighboring prefectures. Five years after the nuclear disaster, the radiation levels have greatly decreased due to physical decay, weathering, and decontamination operations in Fukushima. The populations of 12 communities were forced to evacuate after the accident; as of March 2016, the evacuation order has been lifted in only a limited area, and permanent habitation is still prohibited in most of the areas. In order for the government to lift the evacuation order and for individuals to return to their original residential areas, it is important to assess current and future realistic individual external doses. Here, we used personal dosimeters along with the Global Positioning System and Geographic Information System to understand realistic individual external doses and to relate individual external doses, ambient doses, and activity-patterns of individuals in the affected areas in Fukushima. The results showed that the additional individual external doses were well correlated to the additional ambient doses based on the airborne monitoring survey. The results of linear regression analysis suggested that the additional individual external doses were on average about one-fifth that of the additional ambient doses. The reduction factors, which are defined as the ratios of the additional individual external doses to the additional ambient doses, were calculated to be on average 0.14 and 0.32 for time spent at home and outdoors, respectively. Analysis of the contribution of various activity patterns to the total individual external dose demonstrated good agreement with the average fraction of time spent daily in each activity, but the contribution due to being outdoors varied widely. These results are a valuable contribution to understanding realistic individual external doses and the corresponding

  17. Forces predicted at the ankle during running.

    Burdett, R G

    1982-01-01

    A biomechanical model of the ankle joint was developed and was used to predict the forces at the ankle during the stance phase of running. Measurements from five cadavers were averaged to obtain insertion points and directions of pull of equivalent tendons with respect to the assumed center of the ankle joint. A minimum joint force solution was obtained by assuming that only two equivalent muscle groups could exert force at one time. Three subjects ran at 4.47 m/s across a force platform that recorded the external forces and moments acting on the foot. Cinematography was used to measure the foot and leg positions during stance. Peak resultant joint forces ranging from 9.0 to 13.3 times body weight and peak Achilles tendon forces ranging from 5.3 to 10.0 times body weight were predicted. Small variations in some cases resulted in large differences in predicted forces. The highest tendon forces predicted exceeded those reported to cause damage to cadaver tendons in other studies. PMID:7132650

  18. External Debt and Economic Growth in Tunisia

    Nasfi Fkili Wahiba

    2014-12-01

    Full Text Available The objective of this study is to identify the effect of external debt on economic growth; we used the debt service as percentage of exports and debt indicators in the first and second degree. The econometric estimation showed that the sign of the coefficient of debt is positive and the debt squared is negative, and beyond a certain stock, the impact of debt on growth becomes negative and Tunisia must control its debts as additional increases will have adverse impacts on the economic performance of the country. Therefore, the borrowing should remain a necessity in cases of extreme emergency, not a solution to all economic problems experienced by the country.

  19. TRIGA forced shutdowns analysis

    The need for improving the operation leads us to use new methods and strategies. Probabilistic safety assessments and statistical analysis provide insights useful for our reactor operation. This paper is dedicated to analysis of the forced shutdowns during the first reactor operation period, between 1980 to 1989. A forced shutdown data base was designed using data on forced shutdowns collected from the reactor operation logbooks. In order to sort out the forced shutdowns the records have the following fields: - current number, date, equipment failed, failure type (M for mechanical, E for electrical, D for irradiation device, U for human factor failure; - scram mode, SE for external scram, failure of reactor cooling circuits and/or irradiation devices, SR for reactor scram, exceeding of reactor nuclear parameters, SB for reactor scram by control rod drop, SM for manual scram required by the abnormal reactor status; - scram cause, giving more information on the forced shutdown. This data base was processed using DBase III. The data processing techniques are presented. To sort out the data, one of the criteria was the number of scrams per year, failure type, scram mode, etc. There are presented yearly scrams, total operation time in hours, total unavailable time, median unavailable time period, reactor availability A. There are given the formulae used to calculate the reactor operational parameters. There are shown the scrams per year in the 1980 to 1989 period, the reactor operation time per year, the reactor shutdown time per year and the operating time versus down time per year. Total number of scrams in the covered period was 643 which caused a reactor down time of 4282.25 hours. In a table the scrams as sorted on the failure type is shown. Summarising, this study emphasized some problems and difficulties which occurred during the TRIGA reactor operation at Pitesti. One main difficulty in creating this data base was the unstandardized scram record mode. Some times

  20. Thermodynamic Branch in the Chemical System Response to External Impact

    Zilbergleyt, B

    2012-01-01

    The paper gives an account of a detailed investigation of the thermodynamic branch as a path of the chemical system deviation from its isolated thermodynamic equilibrium under an external impact. For a combination of direct and reverse reactions in the same chemical system, full thermodynamic branch is presented by an S-shaped curve, whose ends asymptotically achieve appropriate initial states, which, in turn, are logistic ends of the opposite reactions. The slope tangents of the steepest parts of the curves, the areas of the maximum rate of the shift growth vs. the external thermodynamic force, occurred to be directly proportional to the force and, simultaneously, linearly proportional to the thermodynamic equivalent of chemical reaction, which is the ratio between the amount in moles of any reaction participant, transformed in an isolated system, along the reaction way from its initial state to thermodynamic equilibrium, to its stoichiometric coefficient. The found linearity is valid for arbitrary combinati...

  1. Euler-Poincare Reduction of Externall Forced Rigid Body Motion

    Wisniewski, Rafal; Kulczycki, P.

    2004-01-01

    If a mechanical system experiences symmetry, the Lagrangian becomes invariant under a certain group action. This property leads to substantial simplification of the description of movement. The standpoint in this article is a mechanical system affected by an external force of a control action...... control system generates an external force, which may break the symmetry in the dynamics. This paper shows how to model and to control a mechanical system on the reduced phase space, such that complete state space asymptotic stabilization can be achieved. The paper comprises a specialization of the well......-known Euler-Poincaré reduction to a rigid body motion with forcing....

  2. Malaysia and forced migration

    Arzura Idris

    2012-01-01

    This paper analyzes the phenomenon of “forced migration” in Malaysia. It examines the nature of forced migration, the challenges faced by Malaysia, the policy responses and their impact on the country and upon the forced migrants. It considers forced migration as an event hosting multifaceted issues related and relevant to forced migrants and suggests that Malaysia has been preoccupied with the issue of forced migration movements. This is largely seen in various responses invoked from Malaysi...

  3. Handbook of force transducers

    Stefanescu, Dan Mihai

    2011-01-01

    Part I introduces the basic ""Principles and Methods of Force Measurement"" acording to a classification into a dozen of force transducers types: resistive, inductive, capacitive, piezoelectric, electromagnetic, electrodynamic, magnetoelastic, galvanomagnetic (Hall-effect), vibrating wires, (micro)resonators, acoustic and gyroscopic. Two special chapters refer to force balance techniques and to combined methods in force measurement. Part II discusses the ""(Strain Gauge) Force Transducers Components"", evolving from the classical force transducer to the digital / intelligent one, with the inco

  4. Learning Policies with External Memory

    Peshkin, Leonid; Meuleau, Nicolas; Kaelbling, Leslie

    2001-01-01

    In order for an agent to perform well in partially observable domains, it is usually necessary for actions to depend on the history of observations. In this paper, we explore a {\\it stigmergic} approach, in which the agent's actions include the ability to set and clear bits in an external memory, and the external memory is included as part of the input to the agent. In this case, we need to learn a reactive policy in a highly non-Markovian domain. We explore two algorithms: SARSA(\\lambda), wh...

  5. Force Augmentation for Relief Valve

    Luger, J.

    1982-01-01

    Simple design change for poppet relief valve enables flow through valve to exert additional force to help keep valve open. Although originally intended for relief valves for liquid oxygen and liquid nitrogen in Space Shuttle orbiter, concept is applicable to pressure-or flow-actuated valves for wide range of fluids and temperatures.

  6. Environmental externalities related to power production on biogas and natural gas based on the EU ExternE methodology

    Nielsen, Per Sieverts; Ibsen, Liselotte Schleisner

    1998-01-01

    European countries. The project use a “bottom-up” methodology to evaluate the external costs associated with a wide range of different fuel cycles. The project has identified priority impacts, where most are impacts from air emissions. Externalities due to atmospheric emissions are calculated through the......This paper assesses the environmental impacts and external costs from selected electricity generation systems in Denmark. The assessment is carried out as part of the ExternE National Implementation, which is the second phase of the ExternE project and involves case studies from all Western...

  7. Towards all-optical control and measurement of Casimir forces via evanescent optical forces

    Rodriguez, Alejandro W; Hui, Pui-Chuen; Iwase, Eiji; McCauley, Alexander P; Capasso, Federico; Loncar, Marko; Johnson, Steven G

    2011-01-01

    We propose an optomechanical structure consisting of a photonic-crystal (holey) membrane suspended above a layered silicon-on-insulator substrate in which resonant bonding/antibonding optical forces created by externally incident light from above enable all-optical control and actuation of stiction effects induced by the Casimir force. The same optical response (reflection spectrum) of the membrane to the incident light can be exploited to accurately measure the effects of the Casimir force on the equilibrium separation of the membrane.

  8. Active disturbance rejection control for output force creep characteristics of ionic polymer metal composites

    Xiong, Yan; Chen, Yang; Sun, Zhiyong; Hao, Lina; Dong, Jie

    2014-07-01

    Ionic polymer metal composites (IPMCs) are a type of electroactive polymer (EAP) that can be used as both sensors and actuators. An IPMC has enormous potential application in the field of biomimetic robotics, medical devices, and so on. However, an IPMC actuator has a great number of disadvantages, such as creep and time-variation, making it vulnerable to external disturbances. In addition, the complex actuation mechanism makes it difficult to model and the demand of the control algorithm is laborious to implement. In this paper, we obtain a creep model of the IPMC by means of model identification based on the method of creep operator linear superposition. Although the mathematical model is not approximate to the IPMC accurate model, it is accurate enough to be used in MATLAB to prove the control algorithm. A controller based on the active disturbance rejection control (ADRC) method is designed to solve the drawbacks previously given. Because the ADRC controller is separate from the mathematical model of the controlled plant, the control algorithm has the ability to complete disturbance estimation and compensation. Some factors, such as all external disturbances, uncertainty factors, the inaccuracy of the identification model and different kinds of IPMCs, have little effect on controlling the output block force of the IPMC. Furthermore, we use the particle swarm optimization algorithm to adjust ADRC parameters so that the IPMC actuator can approach the desired block force with unknown external disturbances. Simulations and experimental examples validate the effectiveness of the ADRC controller.

  9. Basic concept of new screening method for external event PSA

    After the TEPCO's Fukushima Daiichi nuclear power station accident, the importance of developing Probabilistic Safety Assessment (PSA) method is recognized not only for earthquakes in external events but also for broader external events. According to the external events assessment conducted by the U.S. Nuclear Regulatory Commission (NRC) in the 1980s, various external events were used to be selected by two screening methods first, and then estimated Core Damage Frequency (CDF) by the PSA method for the selected external events. However, at several nuclear power plant sites, there is a possibility to remain the too many external events that are not screened out by the above conventional screening methods because these depend on site and the feature of hazard. The purpose of this study is to propose a new screening method in addition to the conventional ones for external event PSA by focusing on failures of components for the fulfillment of CDF target value. In this paper, the proposed method was specifically applied to strong wind (i.e. typhoon), which has the highest frequency and the strongest wind velocity in Japan. As a result, we recognized the possibility of screening out typhoons from the view point of wind-resistant load although further investigation is necessary in terms of the safety functional failures of components. (author)

  10. Organizing for External Knowledge Sourcing

    Rabbiosi, Larissa; Reichstein, Toke

    2011-01-01

    The aim of this article is to provide an introduction to the special issue. We briefly consider the external knowledge sourcing and organizing for innovation literatures, which offer a background for the special issue, and we highlight their mutual dialogue. We then illustrate the main findings of...

  11. Femoral Reconstruction Using External Fixation

    Yevgeniy Palatnik

    2011-01-01

    Full Text Available Background. The use of an external fixator for the purpose of distraction osteogenesis has been applied to a wide range of orthopedic problems caused by such diverse etiologies as congenital disease, metabolic conditions, infections, traumatic injuries, and congenital short stature. The purpose of this study was to analyze our experience of utilizing this method in patients undergoing a variety of orthopedic procedures of the femur. Methods. We retrospectively reviewed our experience of using external fixation for femoral reconstruction. Three subgroups were defined based on the primary reconstruction goal lengthening, deformity correction, and repair of nonunion/bone defect. Factors such as leg length discrepancy (LLD, limb alignment, and external fixation time and complications were evaluated for the entire group and the 3 subgroups. Results. There was substantial improvement in the overall LLD, femoral length discrepancy, and limb alignment as measured by mechanical axis deviation (MAD and lateral distal femoral angle (LDFA for the entire group as well as the subgroups. Conclusions. The Ilizarov external fixator allows for decreased surgical exposure and preservation of blood supply to bone, avoidance of bone grafting and internal fixation, and simultaneous lengthening and deformity correction, making it a very useful technique for femoral reconstruction.

  12. Market Crashes without External Shocks

    Sergiu Hart; Yair Tauman

    2004-01-01

    It is shown here that market crashes and bubbles can arise without external shocks. Sudden changes in behavior coming after a long period of stationarity may be the result of endogenous information processing. Except for the daily observation of the market, there is no new information, no communication and no coordination among the participants.

  13. External costs and public opinion

    Public debate is strongly influencing the way individuals perceive pollution and risk issues. To take these perceptions into account in evaluating external costs, we propose an analysis of the social phenomenon which includes both the physical and symbolic exchanges simultaneously. The generalized social and political model then proposed should be considered a starting point (conceptual scheme) for analyzing individual perceptions. (author). 8 refs

  14. Lupus vulgaris of external nose

    Bhandary, Satheesh Kumar; Ranganna, B. Usha

    2008-01-01

    Lupus vulgaris is the commonest form of cutaneous tuberculosis which commonly involve trunk and buttocks. Lupus vulgaris affecting nose and face, are rarely reported in India. This study reports an unusual case of lupus vulgaris involving the external nose that showed dramatic outcome after six months of anti- tubercular treatment.

  15. The effect of patch potentials in Casimir force measurements determined by heterodyne Kelvin probe force microscopy

    Garrett, Joseph L.; Somers, David; Munday, Jeremy N.

    2014-01-01

    Measurements of the Casimir force require the elimination of electrostatic interactions between the surfaces. However, due to electrostatic patch potentials, the voltage required to minimize the total force may not be sufficient to completely nullify the electrostatic interaction. Thus, these surface potential variations cause an additional force, which can obscure the Casimir force signal. In this paper, we inspect the spatially varying surface potential (SP) of e-beamed, sputtered, sputtere...

  16. Effect of multiple impacts on protective properties of external hip protectors

    Tatjana Bulat

    2008-10-01

    Full Text Available Tatjana Bulat1, Shawn Applegarth1, Stuart Wilkinson2, Shirley G Fitzgerald1, Shahbaz Ahmed1, Patricia Quigley11VISN 8 Patient Safety Center of Inquiry, Tampa, FL, USA; 2University of South Florida Department of Mechanical Engineering, Tampa, FL, USAAbstract: A variety of external hip protectors are available on the market but no standards for their performance exist and it is unknown if their properties change after repeated fall impacts. The purpose of this study was to determine if protective properties change in different types of new (unused hip protectors after repeated, simulated falls. Five hip protector brands were chosen to represent different products available on the market and the two mechanisms employed in reducing the force of an impact (shunting or absorbing. Ten pairs of each type (20 pads for each brand were tested using a 1.8-m Instron Dynatup 9250 HV vertical impact testing tower. The impact testing system was specifically designed for this study by creating a simulated trochanter to provide more accurately a impact area similar to that of a real hip bone. The hip protectors were impacted once a day for 3 consecutive days. Repeated impacts demonstrated the pads’ decreased ability to either absorb or shunt force in all types of hip protectors. However, the mean forces were still in the protective range (force below fracture threshold of 3100 N for 3 of the 5 brands tested after 3 impacts. The protective properties of external hip protectors do degrade after repeated impacts. The degree of degradation differs from brand to brand. Regardless of type, most pads were still able to bring the force of impact below the fracture threshold of 3100 N. Future studies need to address the issue of durability of different types/brands of hip protectors after repeated laundering and fall impacts to determine when should they be replaced. Additionally, a national or international standard needs to be developed against which the performance

  17. Transcriptional Response of Escherichia coli to External Zinc

    Yamamoto, Kaneyoshi; Ishihama, Akira

    2005-01-01

    Transcriptional response of Escherichia coli to extracellular zinc was studied using DNA microarray and S1 mapping assays. Addition of external zinc induced the expression of zinc exporter ZntA and inhibited the expression of zinc importer ZnuC. In the continuous presence of zinc, ZnuC repression took place at lower zinc concentrations than ZntA induction. The microarray assay indicated that the addition of excess external zinc induces the expression of many genes that are organized in the re...

  18. Reassessment of external events in view of the Fukushima accident

    As a consequence of the EU stress tests following the Fukushima NPP accident, the Nordic BWR Owners Group (NOG) initiated an analysis related to the capability of Swedish and Finnish BWR plants to withstand potential effects from external flooding and other extreme natural events. A review of existing analyses was performed with the intention to identify and reassess assumptions and simplifications made, and to judge whether all significant aspects of external events had been identified and considered. A previous NOG project dealing with methodologies for analyzing certain external events was used as a reference. Additional analyses were performed within three sub-projects addressing extreme water levels in the Baltic Sea and Skagerrak, methodology for the analysis of multiple external events, and main heat sink accessibility. It was concluded that the outcome from the previous NOG project can still be used as a basis, but some issues requiring further analysis were also identified. (orig.)

  19. Applications of Lorentz force in medical acoustics: Lorentz force hydrophone, Lorentz Force Electrical Impedance Tomography, Imaging of shear waves induced by Lorentz force

    Grasland-Mongrain, Pol

    2014-01-01

    The ability of the Lorentz force to link a mechanical displacement to an electrical current presents a strong interest for medical acoustics, and three applications were studied in this thesis. In the first part of this work, a hydrophone was developed for mapping the particle velocity of an acoustic field. This hydrophone was constructed using a thin copper wire and an external magnetic field. A model was elaborated to determine the relationship between the acoustic pressure and the measured electrical current, which is induced by Lorentz force when the wire vibrates in the acoustic field of an ultrasound transducer. The built prototype was characterized and its spatial resolution, frequency response, sensitivity, robustness and directivity response were investigated. An imaging method called Lorentz Force Electrical Impedance Tomography was also studied. In this method, a biological tissue is vibrated by ultrasound in a magnetic field, which induces an electrical current by Lorentz force. The electrical imp...

  20. Technical basis document for external events

    This document supports the Tank Farms Documented Safety Analysis and presents the technical basis for the FR-equencies of externally initiated accidents. The consequences of externally initiated events are discussed in other documents that correspond to the accident that was caused by the external event. The external events include aircraft crash, vehicle accident, range fire, and rail accident

  1. Analytical and Numerical Studies for Chaotic Dynamics of a Duffing Oscillator with a Parametric Force

    2007-01-01

    The chaotic dynamics of a Duffing oscillator with a parametric force is investigated. By using the direct perturbation technique, we analytically obtain the general solution of the 1st-order equation. Through the boundedness condition of the general solution we get the famous Melnikov function predicting the onset of chaos. When the parametric and external forces are strong, numerical simulations show that increasing the amplitude of the parametric or external force can lead the system into chaos via period doubling.

  2. Training program to prepare the U.S. DOE laboratories for the entry into force of the protocol additional to the agreement between the United States of America and the International Atomic Energy Agency for the application of safeguards in the United

    Boyer, Brian David [Los Alamos National Laboratory; Stevens, Rebecca C [Los Alamos National Laboratory; Uribe, Eva C [Los Alamos National Laboratory; Sandoval, M Analisa [Los Alamos National Laboratory; Valente, John N [Los Alamos National Laboratory; Valente, John U [BNL; Jo, Jae H [BNL; Sellen, Joana [U.S. DOE/NNSA; Wonder, Edward [QINETIQ-NORTH AMERICA

    2009-01-01

    In 2008, a joint team from Brookhaven National Laboratory (BNL) and Los Alamos National Laboratory (LANL) consisting of specialists in training IAEA inspectors in the use of complementary access activities formulated a training program to prepare the U.S DOE laboratories for the entry into force of the U.S. Additional Protocol. Since the U.S. Additional Protocol would allow for IAEA access to the DOE laboratories under the aegis of complementary access activities, the DOE laboratories would need to prepare for such visits. The goal of the training was to ensure that the DOE laboratories would successfully host an IAEA complementary access. In doing so, the labs must be able to provide the IAEA with the information that the IAEA would need to resolve its questions about the U.S. Declaration and declared activities at the lab, and also protect certain equities, as provided under the U.S. Additional Protocol Article 1.b and c. which set forth a 'National Security Exclusion.' This 'NSE' states that the AP provisions apply within the United States 'excluding only instances where its application would result in access by the Agency to activities with direct national security significance to the United States or to location or information associated with such activities.' These activities are referred to collectively as DNSS-direct national security significance. Furthermore, the U.S. has a specific right to employ managed access, without prejudice to the right under Article 1.b, in connection with activities of DNSS. The provisions in Articles 1.b and 1.c are unique to the U.S. AP, and are additional to the more general right, under Article 7, to use managed access to protect from disclosure proprietary and/or proliferation-sensitive information, and to meet safety and security requirements, that is incorporated directly from the Model Additional Protocol. The BNL-LANL team performed training at Lawrence Livermore National Laboratory, Idaho

  3. Training program to prepare the U.S. DOE laboratories for the entry into force of the protocol additional to the agreement between the United States of America and the International Atomic Energy Agency for the application of safeguards in the United

    In 2008, a joint team from Brookhaven National Laboratory (BNL) and Los Alamos National Laboratory (LANL) consisting of specialists in training IAEA inspectors in the use of complementary access activities formulated a training program to prepare the U.S DOE laboratories for the entry into force of the U.S. Additional Protocol. Since the U.S. Additional Protocol would allow for IAEA access to the DOE laboratories under the aegis of complementary access activities, the DOE laboratories would need to prepare for such visits. The goal of the training was to ensure that the DOE laboratories would successfully host an IAEA complementary access. In doing so, the labs must be able to provide the IAEA with the information that the IAEA would need to resolve its questions about the U.S. Declaration and declared activities at the lab, and also protect certain equities, as provided under the U.S. Additional Protocol Article 1.b and c. which set forth a 'National Security Exclusion.' This 'NSE' states that the AP provisions apply within the United States 'excluding only instances where its application would result in access by the Agency to activities with direct national security significance to the United States or to location or information associated with such activities.' These activities are referred to collectively as DNSS-direct national security significance. Furthermore, the U.S. has a specific right to employ managed access, without prejudice to the right under Article 1.b, in connection with activities of DNSS. The provisions in Articles 1.b and 1.c are unique to the U.S. AP, and are additional to the more general right, under Article 7, to use managed access to protect from disclosure proprietary and/or proliferation-sensitive information, and to meet safety and security requirements, that is incorporated directly from the Model Additional Protocol. The BNL-LANL team performed training at Lawrence Livermore National Laboratory, Idaho National Laboratory, and Oak

  4. External costs of future fusion plants

    Hamacher, T.; Cabal, H.; Hallberg, B.; Korhonen, R.; Lechon, Y.; Saez, R.M.; Schleisner, L

    2001-04-01

    In the framework of the Socio-Economic Research on Fusion (SERF), which was jointly conducted by the European Commission and the Fusion Associations, external costs of future fusion plants were calculated. All the damages that are not reflected in the market price are called external costs. The ExternE methodology was applied. External costs of the fusion power plants are found to be rather low, in the range of a few mEuro/kWh. Radiological impacts are only one source of external effects, but not the dominating one. External costs of fusion compare well with wind and solar energy.

  5. Is Gravity an Entropic Force?

    Shan Gao

    2011-04-01

    Full Text Available The remarkable connections between gravity and thermodynamics seem to imply that gravity is not fundamental but emergent, and in particular, as Verlinde suggested, gravity is probably an entropic force. In this paper, we will argue that the idea of gravity as an entropic force is debatable. It is shown that there is no convincing analogy between gravity and entropic force in Verlinde’s example. Neither holographic screen nor test particle satisfies all requirements for the existence of entropic force in a thermodynamics system. Furthermore, we show that the entropy increase of the screen is not caused by its statistical tendency to increase entropy as required by the existence of entropic force, but in fact caused by gravity. Therefore, Verlinde’s argument for the entropic origin of gravity is problematic. In addition, we argue that the existence of a minimum size of spacetime, together with the Heisenberg uncertainty principle in quantum theory, may imply the fundamental existence of gravity as a geometric property of spacetime. This may provide a further support for the conclusion that gravity is not an entropic force.

  6. The european commission externe project

    The Externe project, begun jointly in 1991 by the European Commission and the U.S. Department of Energy, consists in establishing an accounting framework for evaluating the external environmental costs of energy. So far, the project has concentrated on the main forms of energy used for producing electricity. The environmental costs of coal technologies, nuclear, gas, petroleum, and certain renewables (hydraulic, wind) have been evaluated for European locations. Some thirty research teams have been participating in the project in Europe. The project was originally prompted by the desire to establish a common concept based on physical, technical and economic evaluation methods, and on new clarified definitions of external costs that would be the same in the various countries and for future users. The external costs are thus evaluated: for newly installed equipment, with an ''incremental approach'' to marginal environmental cost; for a specific location; in proportion to the damage done to the environment, on the basis of willingness-to-pay monetary evaluation methods. The physical damage considered is the damage to health, materials, crops, forests, lakes, and rivers; but accidents, noise, unsightliness and potential impact on climatic change are also the subject of exploratory evaluations. The pollutants considered are the now classical SO2, NOx, CO2 particles, aerosols, ozone and radionuclides. Preliminary results have been presented and certain conclusions can already be drawn. In all, the Community project shows that substantial efforts have been made on a large scale, and that these are bearing their first significant, consistent results today. Even though these results may not provide a basis for deciding between one form of energy and another, they already give an indication of the limits within which the questions of internalizing external costs must be stated. The intent of the Community program to establish the Externe accounting framework in all the

  7. Finger Forces in Clarinet Playing

    Hofmann, Alex; Goebl, Werner

    2016-01-01

    Clarinettists close and open multiple tone holes to alter the pitch of the tones. Their fingering technique must be fast, precise, and coordinated with the tongue articulation. In this empirical study, finger force profiles and tongue techniques of clarinet students (N = 17) and professional clarinettists (N = 6) were investigated under controlled performance conditions. First, in an expressive-performance task, eight selected excerpts from the first Weber Concerto were performed. These excerpts were chosen to fit in a 2 × 2 × 2 design (register: low–high; tempo: slow–fast, dynamics: soft–loud). There was an additional condition controlled by the experimenter, which determined the expression levels (low–high) of the performers. Second, a technical-exercise task, an isochronous 23-tone melody was designed that required different effectors to produce the sequence (finger-only, tongue-only, combined tongue-finger actions). The melody was performed in three tempo conditions (slow, medium, fast) in a synchronization-continuation paradigm. Participants played on a sensor-equipped Viennese clarinet, which tracked finger forces and reed oscillations simultaneously. From the data, average finger force (Fmean) and peak force (Fmax) were calculated. The overall finger forces were low (Fmean = 1.17 N, Fmax = 3.05 N) compared to those on other musical instruments (e.g., guitar). Participants applied the largest finger forces during the high expression level performance conditions (Fmean = 1.21 N). For the technical exercise task, timing and articulation information were extracted from the reed signal. Here, the timing precision of the fingers deteriorated the timing precision of the tongue for combined tongue-finger actions, especially for faster tempi. Although individual finger force profiles were overlapping, the group of professional players applied less finger force overall (Fmean = 0.54 N). Such sensor instruments provide useful insights into player

  8. Static magnetic forces and torques in ATLAS

    The magnetic forces acting on the various metallic objects around the ATLAS detector, are the subject of the given paper. A system designer could use the information on global forces and torque acting on various components, obtained in this report, to optimize them. The results of force calculations could also serve as additional criteria for the replacement of the magnetic baseline material of various structures by nonmagnetic ones

  9. Nuclear forces from EFT: Recent developments

    Meißner U.-G.; Epelbaum E.; Krebs H.

    2010-01-01

    Nuclear forces are considered based on chiral perturbation theory with and without explicit ∆-isobar degrees of freedom. We discuss the subleading corrections to chiral three-nucleon forces in the ∆-less formalism which contain no additional free parameters. In the formalism with explicit ∆-isobar we present the complete next-to-next-to-leading order analysis of isospin-conserving and next-to-leading order analysis of isospinviolating nuclear forces. The perturbative expansion of nucle...

  10. Single atom measurement and atomic manipulation using atomic force microscope

    This paper explains studies to measure atomic force as the force linking an atom and atom, using an atomic force microscope (AFM). First, it describes the principle and device configuration of AFM, and as an example of the atomic force measurement of Si atoms on the surface of Si(111)-(7x7), it describes the technique to measure atomic force using AFM, as well as the uncertainty of probe tip against atomic force. In addition, it describes the following items on the measurement results of chemical bonding force: (1) chemical bonding force vs physical force and chemical bonding force vs current on the surface of Si(111)-(7x7), (2) chemical bonding force and element dependence on the surface of Si/Sn(111)-(√3x√3), (3) atomic manipulation based on AMF, and (4) relationship between atomic manipulation and the size of chemical bonding force with a probe. (A.O.)

  11. External costs of energy - do the answers match the questions? Looking back at 10 years of ExternE

    While the claim for 'getting prices right' is quite popular in conceptual policy papers, the implementation of appropriate internalisation strategies is still hampered by a lack of reliable external cost data. Great expectations were set into the ExternE project, a major research programme launched by the European Commission at the beginning of the 1990s to provide a scientific basis for the quantification of energy related externalities and to give guidance supporting the design of internalisation measures. After more than a decade of research, the ExternE label became a well recognised standard source for external cost data. Looking back into the ExternE history, the paper pursues how emerging new scientific insights and changing background assumptions affected external cost estimates and related recommendations to policy over time. Based on ExternE results, the usefulness and inherent limitations of external cost estimates for impact categories like climate change or nuclear waste disposal is discussed. The paper also gives examples on how external costs in spite of remaining uncertainties are successfully used to support environmental policy. (Author)

  12. NOVEL 6-DOF WEARABLE EXOSKELETON ARM WITH PNEUMATIC FORCE-FEEDBACK FOR BILATERAL TELEOPERATION

    ZHANG Jiafan; FU Hailun; DONG Yiming; ZHANG Yu; YANG Canjun; CHEN Ying

    2008-01-01

    A particular emphasis is put on a novel wearable exoskeleton arm, ZJUESA, with 6 degrees of freedom, which is used for the robot teleoperation with the force-feedback in the unknown environment. In this external structure mechanism, the 3-revolution-prismatic-spherical (3RPS) parallel mechanism is devised from the concept of the human upper-limb anatomy and applied for the shoulder 3-DOF joint. Meanwhile, the orthogonal experiment design method is introduced for its optimal design. Aiming at enhancing the performance of teleoperation, the force feedback is employed by the pneumatic system on ZJUESA to produce the vivid feeling in addition to the soft control interface. Due to the compressibility and nonlinearity of the pneumatic force feedback system, a novel hybrid fuzzy controller for the precise force control is proposed and realized based on the Mega8 microcontroller units as the units of the distributed control system on ZJUESA. With the results of several experiments for master-slave control with force feedback, the feasibility of ZJUESA system and the effect of its hybrid fuzzy controller are verified.

  13. Forced versus coupled dynamics in Earth system modelling and prediction

    B. Knopf

    2005-01-01

    Full Text Available We compare coupled nonlinear climate models and their simplified forced counterparts with respect to predictability and phase space topology. Various types of uncertainty plague climate change simulation, which is, in turn, a crucial element of Earth System modelling. Since the currently preferred strategy for simulating the climate system, or the Earth System at large, is the coupling of sub-system modules (representing, e.g. atmosphere, oceans, global vegetation, this paper explicitly addresses the errors and indeterminacies generated by the coupling procedure. The focus is on a comparison of forced dynamics as opposed to fully, i.e. intrinsically, coupled dynamics. The former represents a particular type of simulation, where the time behaviour of one complex systems component is prescribed by data or some other external information source. Such a simplifying technique is often employed in Earth System models in order to save computing resources, in particular when massive model inter-comparisons need to be carried out. Our contribution to the debate is based on the investigation of two representative model examples, namely (i a low-dimensional coupled atmosphere-ocean simulator, and (ii a replica-like simulator embracing corresponding components.Whereas in general the forced version (ii is able to mimic its fully coupled counterpart (i, we show in this paper that for a considerable fraction of parameter- and state-space, the two approaches qualitatively differ. Here we take up a phenomenon concerning the predictability of coupled versus forced models that was reported earlier in this journal: the observation that the time series of the forced version display artificial predictive skill. We present an explanation in terms of nonlinear dynamical theory. In particular we observe an intermittent version of artificial predictive skill, which we call on-off synchronization, and trace it back to the appearance of unstable periodic orbits. We also

  14. External observer reflections on QBism

    Khrennikov, Andrei

    2015-01-01

    In this short review I present my personal reflections on QBism. I have no intrinsic sympathy neither to QBism nor to subjective interpretation of probability in general. However, I have been following development of QBism from its very beginning, observing its evolution and success, sometimes with big surprise. Therefore my reflections on QBism can be treated as "external observer" reflections. I hope that my representation of this interpretation of quantum mechanics (QM) has some degree of objectivity. It may be useful for researchers who are interested in quantum foundations, but do not belong to the QBism-community, because I tried to analyze essentials of QBism critically (i.e., not just emphasizing its advantages, as in a typical publication of QBists). QBists may be interested as well - in comments of an external observer who monitored development of this approach to QM during last 16 years. The second part of the paper is devoted to interpretations of probability, objective versus subjective, and view...

  15. MGR External Events Hazards Analysis

    The purpose and objective of this analysis is to apply an external events Hazards Analysis (HA) to the License Application Design Selection Enhanced Design Alternative 11 [(LADS EDA II design (Reference 8.32))]. The output of the HA is called a Hazards List (HL). This analysis supersedes the external hazards portion of Rev. 00 of the PHA (Reference 8.1). The PHA for internal events will also be updated to the LADS EDA II design but under a separate analysis. Like the PHA methodology, the HA methodology provides a systematic method to identify potential hazards during the 100-year Monitored Geologic Repository (MGR) operating period updated to reflect the EDA II design. The resulting events on the HL are candidates that may have potential radiological consequences as determined during Design Basis Events (DBEs) analyses. Therefore, the HL that results from this analysis will undergo further screening and analysis based on the criteria that apply during the performance of DBE analyses

  16. Parallel External Memory Graph Algorithms

    Arge, Lars Allan; Goodrich, Michael T.; Sitchinava, Nodari

    2010-01-01

    In this paper, we study parallel I/O efficient graph algorithms in the Parallel External Memory (PEM) model, one o f the private-cache chip multiprocessor (CMP) models. We study the fundamental problem of list ranking which leads to efficient solutions to problems on trees, such as computing lowest...... an optimal speedup of ¿(P) in parallel I/O complexity and parallel computation time, compared to the single-processor external memory counterparts....... common ancestors, tree contraction and expression tree evaluation. We also study the problems of computing the connected and biconnected components of a graph, minimum spanning tree of a connected graph and ear decomposition of a biconnected graph. All our solutions on a P-processor PEM model provide...

  17. Firm Search for External Knowledge

    Sofka, Wolfgang; Grimpe, Christoph

    2012-01-01

    to experience the negative performance effects of oversearch. Based on a comprehensive sample of almost 8,000 firms from ten European countries, we find that institutions matter considerably for firms' search activity. Higher market orientation of institutions increases the effectiveness of firms' search...... ignored the institutional context that provides or denies access to external knowledge at the country level. Combining institutional and knowledge search theory, we suggest that the market orientation of the institutional environment and the magnitude of institutional change influence when firms begin...... for external knowledge while higher magnitudes of institutional change decrease it. Our results provide important insights for management on how to adapt search strategies to the institutional context....

  18. MGR External Events Hazards Analysis

    L. Booth

    1999-11-06

    The purpose and objective of this analysis is to apply an external events Hazards Analysis (HA) to the License Application Design Selection Enhanced Design Alternative 11 [(LADS EDA II design (Reference 8.32))]. The output of the HA is called a Hazards List (HL). This analysis supersedes the external hazards portion of Rev. 00 of the PHA (Reference 8.1). The PHA for internal events will also be updated to the LADS EDA II design but under a separate analysis. Like the PHA methodology, the HA methodology provides a systematic method to identify potential hazards during the 100-year Monitored Geologic Repository (MGR) operating period updated to reflect the EDA II design. The resulting events on the HL are candidates that may have potential radiological consequences as determined during Design Basis Events (DBEs) analyses. Therefore, the HL that results from this analysis will undergo further screening and analysis based on the criteria that apply during the performance of DBE analyses.

  19. File: protection against external risks

    A nuclear facility creates risks for its personnel, the public and environment that justify the surveillance that public authorities practice on it. But the phenomenons that develop outside the installation can request the safety of a nuclear facility. These sources of risks external to installations can be bound to human activities (plane crash) or be completely natural ( floods, seismic events) and this approach, even if the risk is exceptional, is a fundamental part of the safety. (N.C.)

  20. Mercosur’s external relations

    Manuel Cienfuegos Mateo

    2001-01-01

    The purpose of this study is a theoretical and practical analysis of Mercosur’s external relations. The article sets out the problems that the exercise of its international legal identity raises in international law and for the national rights of the member states and makes proposals de lege ferenda for its adequate integration into the international framework. From here, it proceeds to a series of general reflections on Mercosur’s international identity in light of the fact that its characte...

  1. External tank space debris considerations

    Elfer, N.; Baillif, F.; Robinson, J.

    1992-01-01

    Orbital debris issues associated with maintaining a Space Shuttle External Tank (ET) on orbit are presented. The first issue is to ensure that the ET does not become a danger to other spacecraft by generating space debris, and the second is to protect the pressurized ET from penetration by space debris or meteoroids. Tests on shield designs for penetration resistance showed that when utilized with an adequate bumper, thermal protection system foam on the ET is effective in preventing penetration.

  2. Atmospheric Externalities and Environmental Taxation.

    Sandmo, Agnar

    2010-01-01

    The paper reviews the theory of environmental taxation under first best and second best conditions. It argues that negative environmental externalities lead to reductions of the provision of public goods, while investment in abatement increases the supply of public goods. Together with optimal tax rules, the paper therefore also derives conditions for the optimal use of resources on abatement. After brief discussions of the dimensions of time and uncertainty, tax reform and the...

  3. Preference Externalities in Media Markets

    Simon P. Anderson; Waldfogel, Joel

    2015-01-01

    Media industries typically exhibit two fundamental features, high fixed costs and heterogeneity of consumer preferences. Daily newspaper markets, for example, tend to support a single product. In other examples, such as radio broadcasting, markets often support multiple differentiated offerings. Both contexts can deliver preference externalities, when the options and well-being for consumers depend on the number and mix of consumers according to their content preferences. This chapter present...

  4. External Mechanisms of Corporate Governance

    Radygin Alexandr; Entov Revold; Mejeraoups I.

    2007-01-01

    The aim of this research paper is to analyze those external corporate governance mechanisms, which either play a practical role or give an idea about the specifics of the Russian model. In the context of general institutional issues first of all market mechanisms are analyzed, which are “in built” into a modern system of corporate governance: financial arkets, corporate control market, bankruptcies. For the 2000’s, issues of improvement of the norms of voluntary regulation of corporate govern...

  5. External debt management in Romania

    Ramona DUMITRIU; Stefanescu, Razvan

    2013-01-01

    This paper approaches the evolution of Romania’s foreign debt in three periods of time: during Nicolae Ceausescu regime, in the transition period and the one which followed the adhesion to European Union. For all three periods the external debt management had to deal with different circumstances: the sharp increase of real interest rates from the 1980s, the lack of credibility on international financial markets from the 1990s or the recent global crisis. We conclude that political regime, the...

  6. Unconventional entropy production in the presence of momentum-dependent forces

    Kwon, Chulan; Yeo, Joonhyun; Lee, Hyun Keun; Park, Hyunggyu

    2016-03-01

    We investigate the unconventional nature of entropy production (EP) in nonequilibrium systems with odd-parity variables that change signs under time reversal. We consider the Brownian motion of a particle in contact with a heat reservoir, where the particle's momentum is an odd-parity variable. In the presence of an external momentum-dependent force, the EP transferred to the environment is found to be not equivalent to the usual reservoir entropy change due to heat transfer. An additional unconventional contribution to the EP, which is crucial for maintaining the non-negativity of the (average) total EP enforced by the second law of thermodynamics, appears. A few examples are considered to elucidate the novel nature of the EP. We also discuss detailed balance conditions with a momentum-dependent force.

  7. Active Vibration Control of a Nonlinear Beam with Self- and External Excitations

    J. Warminski

    2013-01-01

    Full Text Available An application of the nonlinear saturation control (NSC algorithm for a self-excited strongly nonlinear beam structure driven by an external force is presented in the paper. The mathematical model accounts for an Euler-Bernoulli beam with nonlinear curvature, reduced to first mode oscillations. It is assumed that the beam vibrates in the presence of a harmonic excitation close to the first natural frequency of the beam, and additionally the beam is self-excited by fluid flow, which is modelled by a nonlinear Rayleigh term for self-excitation. The self- and externally excited vibrations have been reduced by the application of an active, saturation-based controller. The approximate analytical solutions for a full structure have been found by the multiple time scales method, up to the first-order approximation. The analytical solutions have been compared with numerical results obtained from direct integration of the ordinary differential equations of motion. Finally, the influence of a negative damping term and the controller's parameters for effective vibrations suppression are presented.

  8. ENDOSCOPIC DCR VERSUS EXTERNAL DCR

    Rukma

    2015-04-01

    Full Text Available PURPOSE: To compare success rates of endoscopic dacryocystorhinostomy (DCR and external DCR for acquired nasolacrimal duct obstruction (NLDO. MATERIALS AND METHODS: A prospective comparative non randomized study of 64 patients who presented with acquired NLD obstruction to a tertiary hospital. They were fully evaluated to ascertain the site of obstruction and patients with distal obstruction were included in the study. 34 patients underwent endoscopic DCR and 30 patients underwent external DCR RESULTS: 64 patients were included in the study and 72 procedures carried out. Success was achieved in 65 cases and failure in 7. Of the 7 failed cases, anatomical obstruction at the fistula site was found in 3, whereas functional failure was found in 4. In our patients, endoscopic DCR had a significantly higher success rate than external DCR, 95.23% versus 83.33% (P = 0.03. CONCLUSIONS: The success rate of Endoscopic DCR for acquired NLDO in our group of patients was 95.23%, with endoscopic surgery showing better results.

  9. Individuals' insight into intrapersonal externalities

    David J. Stillwell

    2012-07-01

    Full Text Available An intrapersonal externality exists when an individual's decisions affect the outcomes of her future decisions. It can result in decreasing or increasing average returns to the rate of consumption, as occurs in addiction or exercise. Experimentation using the Harvard Game, which models intrapersonal externalities, has found differences in decision making between drug users and control subjects, leading to the argument that these externalities influence the course of illicit drug use. Nevertheless, it is unclear how participants who behave optimally conceptualise the problem. We report two experiments using a simplified Harvard Game, which tested the differences in contingency knowledge between participants who chose optimally and participants who did not. Those who demonstrated optimal performance exhibited both a pattern of correct responses and systematic errors to questions about the payoff schedules. The pattern suggested that they learned explicit knowledge of the change in reinforcement on a trail-by-trial basis. They did not have, or need, a full knowledge of the historical interaction leading to each payoff. We also found no evidence of choice differences between participants who were given a guaranteed payment and participants who were paid contingent on their performance, but those given a guaranteed payment were able to report more contingency knowledge as the experiment progressed, suggesting that they explored more rather than settling into a routine. Experiment 2 showed that using a fixed inter-trial interval did not change the results.

  10. External indebtedness of Croatian banks

    Antun Jurman

    2005-06-01

    Full Text Available The paper analyses the main characteristics of the foreign assets and foreign liabilities of the banks that to a great extent include credit and deposit activities with non-residents – foreign physical persons and legal entities, mostly with foreign banks. The author in this paper analyses the size and trends of the Republic of Croatia’s external debt with regard to gross domestic product, import, export, international reserve of the Croatian National Bank (HNB, etc. The author also discusses external debt of the banks that have, during the past few years, contributed substantially to the overall external debt of the Republic of Croatia. The autor points out that the banks have used foreign sources mainly for placing citizens’ loans, and less for financing development projects and economy. Thus, the banks have “spent”, i.e. used up their credit capacity as well as the credit capacity of the Republic of Croatia. Regardless of the fact that the banks have improved the quality of their assets, maintained liquidity/solvency and made extremely good profits, there have not been positive effects of the multiplication of credits/loans and deposits nor have there been the awaited effects on the growth of the gross domestic product and employment that otherwise might have been achieved via different foreign resources investment policy

  11. Assessing the industry using Porter's five forces.

    2014-01-01

    To develop a business and plan for the future, there is a need to assess the current situation. One way of doing this is to use Porter's five forces framework. This was the brainchild of Harvard Business School's Michael Porter and developed in 1979. Looking at the competitive intensity of an industry, the model assesses internal and external factors that act together to determine the direction of the business; taken together, this gives an indication of the attractiveness of the industry. PMID:24470612

  12. History of special operations forces in Malaysia

    Rahman, Shamsul Afkar bin Abd

    2013-01-01

    Approved for public release; distribution is unlimited From 1941 to 1990, Malaysia was involved in violent conflicts against internal and external threats. Most military literature does not emphasize the role of Special Operations Forces (SOF) during these five decades of conflicts. This thesis highlights some lessons learned that might be useful for countries with strategic and operational concerns similar to Malaysia, details the contributions of the SOF to Malaysia from World War II to ...

  13. ExternE: Externalities of energy Vol. 4. Oil and gas

    Awareness of the environmental damage resulting from human activity, particularly commencing energy use, has grown greatly in recent years. Effects such as global warming, ozone depletion and acid rain are now the subjects of much research and public debate. It is now known that these and other effects damage a wide range of receptors, including human health, forests, crops, freshwater ecosystems and buildings. Such damages are typically not accounted for by the producers and consumers of the good in question (in this case energy). They are thus referred to as 'external costs' or 'externalities', to distinguish them from the private costs which account for the construction of plant, cost of fuel, wages, etc. In recent years there has been a growing interest in the assessment of the environmental and health impacts of energy, and the related external costs. This concern is driven by a number of different factors: the need to integrate environmental concerns in decision making over the choice between different fuels and energy technologies; the need to evaluate the costs and benefits of stricter environmental standards; increased attention to the use of economic instruments for environmental policy, the need to develop overall indicators of environmental performance of different technologies; major changes in the energy sector, including privatisation, liberalisation of markets, reduction of subsidies, etc. An agreed methodology for calculation and integration of external costs has not been established. Earlier work is typically of a preliminary nature and tends to be deficient with respect to both the methods employed and the quality of models and data used. In consequence of this a collaborative project, the EC/US Fuel Cycles Study, was established between Directorate General XLI (Science, Research and Technology) of the European Commission and the United States Department of Energy. This ran for the period 1991 to 1993, and good agreement on a variety of

  14. Kyrgyzstan: Internal and External Course of Development

    Vadim Volovoj

    2015-03-01

    Full Text Available After collapse of the Soviet Union Central Asia (CA was not in the focus of academic society and big geopolitical players, Kyrgyzstan not being an exception. But today Russia is back to CA through the Eurasian Economic Union (EEU and Collective Security Treaty Organization (CSTO. Kyrgyzstan is a member of CSTO and is going to join the EEU. Therefore it is worth of broader analysis. This study tried to understand specifics of Kyrgyz internal and external course of development. It found that internal political process in Kyrgyzstan used to be very problematic. The country suffered a lot from two revolutions, caused by the authoritarian “family rule” of Askar Akaev and Kurmanbek Bakiev. After that Kyrgyzstan decided to change its system of government from presidential to parliamentary (or semi-presidential model. But this experiment did not bring peace and stability, additionally complicated by ethnic tension between Kyrgyz and Uzbek citizens. Possible recipe of success – bigger socio-economic responsibility of the government, but it is still not in place. After two people revolts Kyrgyzstan was near to become a “failed state”, but orientation towards strategic partnership with Russia and membership in the EEU can help it to survive politically and economically at the expense of Russian geopolitical ambitions, compensate internal political turbulence by external factor of stability. Moreover, close (also institutional cooperation with Moscow strengthens systemic power of Kyrgyzstan in its relations with the closest neighbors, such as Uzbekistan (not satisfied with the water policy of Bishkek and Afghanistan (poses real security threat of Islamic extremism and terrorism to Kyrgyzstan. To sum up, for the moment Kyrgyz internal politics is hardly predictable, also because of the parliamentary experiment, but definite external orientation towards Russia and the EEU creates some basis for stable long term development of the country.

  15. Design for Additive Manufacturing

    Bertran Comellas, Martí

    2012-01-01

    This Thesis, Design for Additive Manufacturing, has been mainly focused on the design process and the considerations to be taken into account when designing parts for Additive Manufacturing. It starts with an introduction to Additive Manufacturing, the different technologies and processes are described to let the readers understand their operating principle, materials used and their strengths and weaknesses. The applications of Additive manufacturing are also explained in the introductory ...

  16. Repulsive casimir forces

    We discuss repulsive Casimir forces between dielectric materials with nontrivial magnetic susceptibility. It is shown that considerations based on the naive pairwise summation of van der Waals and Casimir-Polder forces may not only give an incorrect estimate of the magnitude of the total Casimir force but even the wrong sign of the force when materials with high dielectric and magnetic responses are involved. Indeed repulsive Casimir forces may be found in a large range of parameters, and we suggest that the effect may be realized in known materials. The phenomenon of repulsive Casimir forces may be of importance both for experimental study and for nanomachinery applications

  17. How weather impacts the forced climate response

    Kirtman, Ben P. [University of Miami, Division of Meteorology and Physical Oceanography, Rosenstiel School for Atmospheric and Marine Science, Miami, FL (United States); Center for Ocean-Land-Atmosphere Studies, Calverton, MD (United States); Schneider, Edwin K.; Straus, David M. [George Mason University, Department of Atmospheric, Oceanic and Earth Sciences, Fairfax, VA (United States); Center for Ocean-Land-Atmosphere Studies, Calverton, MD (United States); Min, Dughong; Burgman, Robert [University of Miami, Division of Meteorology and Physical Oceanography, Rosenstiel School for Atmospheric and Marine Science, Miami, FL (United States)

    2011-12-15

    The new interactive ensemble modeling strategy is used to diagnose how noise due to internal atmospheric dynamics impacts the forced climate response during the twentieth century (i.e., 1870-1999). The interactive ensemble uses multiple realizations of the atmospheric component model coupled to a single realization of the land, ocean and ice component models in order to reduce the noise due to internal atmospheric dynamics in the flux exchange at the interface of the component models. A control ensemble of so-called climate of the twentieth century simulations of the Community Climate Simulation Model version 3 (CCSM3) are compared with a similar simulation with the interactive ensemble version of CCSM3. Despite substantial differences in the overall mean climate, the global mean trends in surface temperature, 500 mb geopotential and precipitation are largely indistinguishable between the control ensemble and the interactive ensemble. Large differences in the forced response; however, are detected particularly in the surface temperature of the North Atlantic. Associated with the forced North Atlantic surface temperature differences are local differences in the forced precipitation and a substantial remote rainfall response in the deep tropical Pacific. We also introduce a simple variance analysis to separately compare the variance due to noise and the forced response. We find that the noise variance is decreased when external forcing is included. In terms of the forced variance, we find that the interactive ensemble increases this variance relative to the control. (orig.)

  18. Force propagation and force generation in cells.

    Jonas, Oliver; Duschl, Claus

    2010-09-01

    Determining how forces are produced by and propagated through the cytoskeleton (CSK) of the cell is of great interest as dynamic processes of the CSK are intimately correlated with many molecular signaling pathways. We are presenting a novel approach for integrating measurements on cell elasticity, transcellular force propagation, and cellular force generation to obtain a comprehensive description of dynamic and mechanical properties of the CSK under force loading. This approach uses a combination of scanning force microscopy (SFM) and Total Internal Reflection Fluorescence (TIRF) microscopy. We apply well-defined loading schemes onto the apical cell membrane of fibroblasts using the SFM and simultaneously use TIRF microscopy to image the topography of the basal cell membrane. The locally distinct changes of shape and depth of the cytoskeletal imprints onto the basal membrane are interpreted as results of force propagation through the cytoplasm. This observation provides evidence for the tensegrity model and demonstrates the usefulness of our approach that does not depend on potentially disturbing marker compounds. We confirm that the actin network greatly determines cell stiffness and represents the substrate that mediates force transduction through the cytoplasm of the cell. The latter is an essential feature of tensegrity. Most importantly, our new finding that, both intact actin and microtubule networks are required for enabling the cell to produce work, can only be understood within the framework of the tensegrity model. We also provide, for the first time, a direct measurement of the cell's mechanical power output under compression at two femtowatts. PMID:20607861

  19. Lorentz force correction to the Boltzmann radiation transport equation and its implications for Monte Carlo algorithms

    To establish a theoretical framework for generalizing Monte Carlo transport algorithms by adding external electromagnetic fields to the Boltzmann radiation transport equation in a rigorous and consistent fashion. Using first principles, the Boltzmann radiation transport equation is modified by adding a term describing the variation of the particle distribution due to the Lorentz force. The implications of this new equation are evaluated by investigating the validity of Fano’s theorem. Additionally, Lewis’ approach to multiple scattering theory in infinite homogeneous media is redefined to account for the presence of external electromagnetic fields. The equation is modified and yields a description consistent with the deterministic laws of motion as well as probabilistic methods of solution. The time-independent Boltzmann radiation transport equation is generalized to account for the electromagnetic forces in an additional operator similar to the interaction term. Fano’s and Lewis’ approaches are stated in this new equation. Fano’s theorem is found not to apply in the presence of electromagnetic fields. Lewis’ theory for electron multiple scattering and moments, accounting for the coupling between the Lorentz force and multiple elastic scattering, is found. However, further investigation is required to develop useful algorithms for Monte Carlo and deterministic transport methods. To test the accuracy of Monte Carlo transport algorithms in the presence of electromagnetic fields, the Fano cavity test, as currently defined, cannot be applied. Therefore, new tests must be designed for this specific application. A multiple scattering theory that accurately couples the Lorentz force with elastic scattering could improve Monte Carlo efficiency. The present study proposes a new theoretical framework to develop such algorithms. (paper)

  20. Lorentz force correction to the Boltzmann radiation transport equation and its implications for Monte Carlo algorithms

    Bouchard, Hugo; Bielajew, Alex

    2015-07-01

    To establish a theoretical framework for generalizing Monte Carlo transport algorithms by adding external electromagnetic fields to the Boltzmann radiation transport equation in a rigorous and consistent fashion. Using first principles, the Boltzmann radiation transport equation is modified by adding a term describing the variation of the particle distribution due to the Lorentz force. The implications of this new equation are evaluated by investigating the validity of Fano’s theorem. Additionally, Lewis’ approach to multiple scattering theory in infinite homogeneous media is redefined to account for the presence of external electromagnetic fields. The equation is modified and yields a description consistent with the deterministic laws of motion as well as probabilistic methods of solution. The time-independent Boltzmann radiation transport equation is generalized to account for the electromagnetic forces in an additional operator similar to the interaction term. Fano’s and Lewis’ approaches are stated in this new equation. Fano’s theorem is found not to apply in the presence of electromagnetic fields. Lewis’ theory for electron multiple scattering and moments, accounting for the coupling between the Lorentz force and multiple elastic scattering, is found. However, further investigation is required to develop useful algorithms for Monte Carlo and deterministic transport methods. To test the accuracy of Monte Carlo transport algorithms in the presence of electromagnetic fields, the Fano cavity test, as currently defined, cannot be applied. Therefore, new tests must be designed for this specific application. A multiple scattering theory that accurately couples the Lorentz force with elastic scattering could improve Monte Carlo efficiency. The present study proposes a new theoretical framework to develop such algorithms.

  1. External analysis of the Spanish telecommunication industry

    Casado Izcue, Ibán

    2014-01-01

    The aim of the project is to determine the attractiveness of the Spanish telecommunication industry. This sector shows a great dynamism with continuous mergers and acquisitions, market regulations in response to company’s market power and, in addition, it is present in the daily life of millions of people. The PESTLE, Porter´s Five Forces and the Strategic Groups analyses are the tools that helped to define this industry´s attractiveness. The Pestle analysis showed some positive and very nega...

  2. Forces in general relativity

    Many textbooks dealing with general relativity do not demonstrate the derivation of forces in enough detail. The analyses presented herein demonstrate straightforward methods for computing forces by way of general relativity. Covariant divergence of the stress-energy-momentum tensor is used to derive a general expression of the force experienced by an observer in general coordinates. The general force is then applied to the local co-moving coordinate system of a uniformly accelerating observer, leading to an expression of the inertial force experienced by the observer. Next, applying the general force in Schwarzschild coordinates is shown to lead to familiar expressions of the gravitational force. As a more complex demonstration, the general force is applied to an observer in Boyer-Lindquist coordinates near a rotating, Kerr black hole. It is then shown that when the angular momentum of the black hole goes to zero, the force on the observer reduces to the force on an observer held stationary in Schwarzschild coordinates. As a final consideration, the force on an observer moving in rotating coordinates is derived. Expressing the force in terms of Christoffel symbols in rotating coordinates leads to familiar expressions of the centrifugal and Coriolis forces on the observer. It is envisioned that the techniques presented herein will be most useful to graduate level students, as well as those undergraduate students having experience with general relativity and tensor analysis.

  3. The effect of patch potentials in Casimir force measurements determined by heterodyne Kelvin probe force microscopy

    Garrett, Joseph L.; Somers, David; Munday, Jeremy N.

    2015-06-01

    Measurements of the Casimir force require the elimination of the electrostatic force between the surfaces. However, due to electrostatic patch potentials, the voltage required to minimize the total force may not be sufficient to completely nullify the electrostatic interaction. Thus, these surface potential variations cause an additional force, which can obscure the Casimir force signal. In this paper, we inspect the spatially varying surface potential of e-beamed, sputtered, sputtered and annealed, and template stripped gold surfaces with Heterodyne amplitude modulated Kelvin probe force microscopy (HAM-KPFM). It is demonstrated that HAM-KPFM improves the spatial resolution of surface potential measurements compared to amplitude modulated Kelvin probe force microscopy. We find that patch potentials vary depending on sample preparation, and that the calculated pressure can be similar to the pressure difference between Casimir force calculations employing the plasma and Drude models.

  4. What Determines the Static Force Chains in Stressed Granular Media?

    Gendelman, Oleg; Pollack, Yoav G; Procaccia, Itamar; Sengupta, Shiladitya; Zylberg, Jacques

    2016-02-19

    The determination of the normal and transverse (frictional) interparticle forces within a granular medium is a long-standing, daunting, and yet unresolved problem. We present a new formalism that employs the knowledge of the external forces and the orientations of contacts between particles (of any given size), to compute all the interparticle forces. Having solved this problem, we exemplify the efficacy of the formalism showing that the force chains in such systems are determined by an expansion in the eigenfunctions of a newly defined operator. PMID:26943559

  5. Malaysia and forced migration

    Arzura Idris

    2012-06-01

    Full Text Available This paper analyzes the phenomenon of “forced migration” in Malaysia. It examines the nature of forced migration, the challenges faced by Malaysia, the policy responses and their impact on the country and upon the forced migrants. It considers forced migration as an event hosting multifaceted issues related and relevant to forced migrants and suggests that Malaysia has been preoccupied with the issue of forced migration movements. This is largely seen in various responses invoked from Malaysia due to “south-south forced migration movements.” These responses are, however, inadequate in terms of commitment to the international refugee regime. While Malaysia did respond to economic and migration challenges, the paper asserts that such efforts are futile if she ignores issues critical to forced migrants.

  6. Three-nucleon forces

    In this paper, the role of three-nucleon forces in ab initio calculations of nuclear systems is investigated. The difference between genuine and induced many-nucleon forces is emphasized. Induced forces arise in the process of solving the nuclear many-body problem as technical intermediaries toward calculationally converged results. Genuine forces make up the Hamiltonian. They represent the chosen underlying dynamics. The hierarchy of contributions arising from genuine two-, three- and many-nucleon forces is discussed. Signals for the need of the inclusion of genuine three-nucleon forces are studied in nuclear systems, technically best under control, especially in three-nucleon and four-nucleon systems. Genuine three-nucleon forces are important for details in the description of some observables. Their contributions to observables are small on the scale set by two-nucleon forces. (author)

  7. Hydrophobic Forces in Flotation

    Pazhianur, Rajesh R

    1999-01-01

    An atomic force microscope (AFM) has been used to conduct force measurements to better understand the role of hydrophobic forces in flotation. The force measurements were conducted between a flat mineral substrate and a hydrophobic glass sphere in aqueous solutions. It is assumed that the hydrophobic glass sphere may simulate the behavior of air bubbles during flotation. The results may provide information relevant to the bubble-particle interactions occurring during flotation. The glass ...

  8. Casimir Force Between Quantum Plasmas

    Field fluctuations are responsible for an attractive force - the Casimir force - between two parallel (globally neutral) metallic plates separated by a distance d. At high temperature, or equivalently large d, this force is known to exhibit a classical and universal character (independent of the material constitution of the plates). In a recent work, we have displayed the microscopic mechanisms responsible for this universality within a classical model. The plates consist of slabs containing classical charged particles in fluid phase and thermal equilibrium (plasmas). The universality of the force proves to originate from screening sum rules satisfied by the charge correlations. Here we show how this result is altered when the quantum-mechanical nature of the particles is taken into account. It turns out that in addition to the classical result, the asymptotic force for large d comprises a non-universal quantum correction, which is, however, small at high temperature. The method relies on an exact representation of the charge correlations by quantum Mayer graphs, based on the Feynman-Kac path integral formalism. (author)

  9. Theoretical analysis of natural frequency of externally prestressed concrete beam based on rigidity correction

    2009-01-01

    A dynamic test on externally prestressed simply supported concrete beams separately with three typical types of tendon distributions was conducted. The results show that the natural frequencies of the beams increase with the increase in the prestressing force at the tensioning stage, and the natural frequencies decrease after the cracks occur in the beams. Following the calculation formula of natural frequency of externally prestressed beam, which was reported in a literature, the natural frequencies of the...

  10. Sectoral Composition of Foreign Direct Investment and External Vulnerability in Eastern Europe

    Yuko Kinoshita

    2011-01-01

    In the run up to the global crisis, countries in Central Eastern and Southeastern Europe attracted large capital inflows and some of them built up large external imbalances. This paper investigates whether these imbalances are linked to the sectoral composition of FDI. It shows that FDI in the tradable sectors leads to an improvement of the external balance. We also find that the countries with large market size, good infrastructure, greater trade integration, and educated labor force are mor...

  11. Free Riders, Holdouts, and Public Use: A Tale of Two Externalities

    Thomas J. Miceli

    2009-01-01

    Free riders and holdouts are market failures that potentially impede the completion of otherwise beneficial transactions. The key difference is that the free rider problem is a demand side externality that requires taxation to compel payment for a public good, while the holdout problem is a supply side externality that requires eminent domain to force the sale of land for large scale projects. This paper highlights that distinction between these two problems and uses the resulting insights to...

  12. Novel Rigid External Distraction Device Improves Stability and Controls the Vector During Midfacial Advancement.

    Resnick, Cory M; Rottgers, Stephen Alex; Langenfeld, Christopher C; Mulliken, John B; Padwa, Bonnie L

    2016-06-01

    The major limitation of the rigid external devices currently used for midfacial distraction after subcranial Le Fort III osteotomies is the ductile wire that connects the midface to the device, which makes it difficult to control the vector and force during distraction. The authors describe a novel external appliance that addresses this and other problems of contemporary devices, and application of a custom cranial template that facilitates precise placement of the device to achieve the planned vector of distraction. PMID:27213737

  13. Additives in yoghurt production

    Milna Tudor

    2008-02-01

    Full Text Available In yoghurt production, mainly because of sensory characteristics, different types of additives are used. Each group, and also each substance from the same group has different characteristics and properties. For that reason, for improvement of yoghurt sensory characteristics apart from addition selection, the quantity of the additive is very important. The same substance added in optimal amount improves yoghurt sensory attributes, but too small or too big addition can reduce yoghurt sensory attributes. In this paper, characteristics and properties of mostly used additives in yoghurt production are described; skimmed milk powder, whey powder, concentrated whey powder, sugars and artificial sweeteners, fruits, stabilizers, casein powder, inulin and vitamins. Also the impact of each additive on sensory and physical properties of yoghurt, syneresis and viscosity, are described, depending on used amount added in yoghurt production.

  14. CIRCULAR CRACK IN A TRANSVERSELY ISOTROPIC PIEZOELECTRIC SPACE UNDER POINT FORCES AND POINT CHARGES

    侯鹏飞; 丁皓江; 关富玲

    2002-01-01

    In this paper, two kinds of circular crack including external circular crack and penny-shaped crack in a transversely isotropic piezoelectric space are considered. Firstly, we obtain the solution to the problem of an external circular crack in a transversely isotropic piezoelectric space subjected to antisymmetric normal point forces and point charges. Based on this, the solution of one-sided loading of an external circular crack is constructed. Secondly, the real shape of an external circular crack and the opening displacement of a penny-shaped crack under an arbitrary point force and point charge are further obtained. At last, the results are presented in a graphical form.

  15. Effective Nuclear Forces

    Calculation of effective forces in nuclei from the Hamada- Johnston potential is described. This work begins from the theories of Brueckner and Bethe and applies them to finite systems. Various renormalizations of the force are discussed. The density dependence of the effective forces is considered in detail. Arguments for the partial breakdown of the shell model in heavy nuclei are given. (author)

  16. Forces in General Relativity

    Ridgely, Charles T.

    2010-01-01

    Many textbooks dealing with general relativity do not demonstrate the derivation of forces in enough detail. The analyses presented herein demonstrate straightforward methods for computing forces by way of general relativity. Covariant divergence of the stress-energy-momentum tensor is used to derive a general expression of the force experienced…

  17. Debunking Coriolis Force Myths

    Shakur, Asif

    2014-01-01

    Much has been written and debated about the Coriolis force. Unfortunately, this has done little to demystify the paradoxes surrounding this fictitious force invoked by an observer in a rotating frame of reference. It is the purpose of this article to make another valiant attempt to slay the dragon of the Coriolis force! This will be done without…

  18. Influence of orbital forcing and solar activity on water isotopes in precipitation during the mid and late Holocene

    S. Dietrich

    2012-08-01

    Full Text Available In this study we investigate the impact of mid and late Holocene orbital forcing and solar activity on variations of the oxygen isotopic composition in precipitation. Our study is based on a set of novel climate simulations performed with the atmosphere general circulation model ECHAM5-wiso enhanced by explicit water isotope diagnostics. From the performed model experiments we derive the following major results: (1 the response of both orbital and solar forcing lead to changes in surface temperatures and δ18O in precipitation with similar magnitudes during the mid and late Holocene. (2 Past δ18O anomalies correspond to changing temperatures in the orbital driven simulations. This does not hold true if an additional solar forcing is added. (3 Two orbital driven mid Holocene experiments, simulating the mean climate state approximately 5000 and 6000 yr ago, yield very similar results. However, if an identical additional solar activity-induced forcing is added, the simulated changes of surface temperatures as well as δ18O between both periods differ. From our findings we conclude that the Holocene variability of δ18O in precipitation, as stored in many paleoclimate archives, is rather complex to understand since the combined effect of different external forcings on δ18O in precipitation is non-linear.

  19. Additive usage levels.

    Langlais, R

    1996-01-01

    With the adoption of the European Parliament and Council Directives on sweeteners, colours and miscellaneous additives the Commission is now embarking on the project of coordinating the activities of the European Union Member States in the collection of the data that are to make up the report on food additive intake requested by the European Parliament. This presentation looks at the inventory of available sources on additive use levels and concludes that for the time being national legislation is still the best source of information considering that the directives have yet to be transposed into national legislation. Furthermore, this presentation covers the correlation of the food categories as found in the additives directives with those used by national consumption surveys and finds that in a number of instances this correlation still leaves a lot to be desired. The intake of additives via food ingestion and the intake of substances which are chemically identical to additives but which occur naturally in fruits and vegetables is found in a number of cases to be higher than the intake of additives added during the manufacture of foodstuffs. While the difficulties are recognized in contributing to the compilation of food additive intake data, industry as a whole, i.e. the food manufacturing and food additive manufacturing industries, are confident that in a concerted effort, use data on food additives by industry can be made available. Lastly, the paper points out that with the transportation of the additives directives into national legislation and the time by which the food industry will be able to make use of the new food legislative environment several years will still go by; food additives use data by the food industry will thus have to be reviewed at the beginning of the next century. PMID:8792135

  20. Vicarious Michael Addition

    2006-01-01

    C-H bond can undergo vicarious Michael addition reaction (VMA) with doubleactivated double bond in the absence of strong base and catalyst under mild conditions.Intramolecular H-bonding, electron-withdrawing inductive effect, and steric hindrance at aposition of nucleophile facilitates C-H addition over N-H addition. By using VMA, high branching multiplicity, novel branching pattern, controllable density and distribution of functional groups can be envisioned for novel dendrimer synthesis.

  1. Wire + Arc Additive Manufacturing

    Williams, Stewart W.; Martina, Filomeno; Addison, Adrian C.; Ding, Jialuo; Pardal, Goncalo; Colegrove, Paul A.

    2016-01-01

    Depositing large components (>10 kg) in titanium, aluminium, steel and other metals is possible using Wire + Arc Additive Manufacturing. This technology adopts arc welding tools and wire as feedstock for additive manufacturing purposes. High deposition rates, low material and equipment costs, and good structural integrity make Wire+Arc Additive Manufacturing a suitable candidate for replacing the current method of manufacturing from solid billets or large forgings, especially with regards to ...

  2. Skepticism, Contextualism, Externalism and Modality

    Ron Wilburn

    2006-12-01

    Full Text Available In this paper, I argue for the following claims. Contextualist strategies to tame or localize epistemic skepticism are hopeless if contextualist factors are construed internalistically. However, because efforts to contextualize externalism via subjunctive conditional analysis court circularity, it is only on an internalistic interpretation that contextualist strategies can even be motivated. While these claims do not give us an argument for skepticism, they do give us an argument that contextualism, as such, is not likely to provide us with an argument against skepticism.

  3. Matchings with Externalities and Attitudes

    Branzei, Simina; Michalak, Tomasz; Rahwan, Talal;

    2013-01-01

    Two-sided matchings are an important theoretical tool used to model markets and social interactions. In many real-life problems the utility of an agent is influenced not only by their own choices, but also by the choices that other agents make. Such an influence is called an externality. Whereas ...... where agents take different attitudes when reasoning about the actions of others. In particular, we study optimistic, neutral and pessimistic attitudes and provide both computational hardness results and polynomial-time algorithms for computing stable outcomes....

  4. Heat regenerative external combustion engine

    Duva, Anthony W.

    1993-10-01

    A heat regenerative external combustion engine is disclosed. The engine includes fuel inlet means which extends along the exhaust passage and/or combustion chamber in order to preheat the fuel, To provide for preheating by gases in both the combustion chamber and the exhaust passage, the combustion chamber is arranged annularly around the drive shaft and between the cylinders. This configuration also is advantageous in that it reduces the noise of combustion. The engine of the invention is particularly well-suited for use in a torpedo.

  5. EXTERNALITY EFFECTS OF HONEY PRODUCTION

    Arvane Vanyi, Georgina; Csapo, Zsolt; Karpati, Laszlo

    2012-01-01

    Bee-keeping and honey production has a long history in Hungary. Honey is an important and healthy food of people and it can be consumed without any human processing. The honey production has important role, too. Some researchers say that if honey bee will extinct the humanity in the world would also extinct. It is true since plant pollination by honey bees is very important. It is confirmed by researchers’ studies that plant pollination by honey bees has significant positive external impact...

  6. Fligt Dynamics Facility - External Interfaces

    Gonçalves, João Manuel Ribeiro

    2007-01-01

    Trabalho de projecto de mestrado , Engenharia Informática, Universidade de Lisboa, Faculdade de Ciências, 2007 O sistema Galileo consiste numa constelação de 30 satélites que disponibilizará diversos serviços, entre os quais, serviços de posicionamento e navegação alternativos aos actualmente disponibilizados pelo GPS. Neste projecto será concebido o componente External Interfaces que é parte integrante do elemento Flight Dynamics Facility (FDF), responsável pelo cálculo das órbitas e comp...

  7. Measurement of Prestressing Force in Pretensioned UHPC Deck Using a Fiber Optic FBG Sensor Embedded in a 7-Wire Strand

    Jae-min Kim

    2016-01-01

    Full Text Available This paper presents the results of the performance test and long-term monitoring of the prestressing force inside concrete performed on a pretensioned Ultra-High Performance Concrete (UHPC deck. The force is measured by applying a 7-wire strand embedded with an FBG (Fiber Bragg Grating sensor. The performance test was conducted on a 3.7 m × 1.8 m pretensioned deck specimen through wheel loading tests to verify the applicability of the measurement method. In addition, a 12.3 m long and 4.8 m wide bridge with a pretensioned UHPC deck was erected and long-term monitoring was conducted over three years to verify the applicability of the method to real bridges. The effectiveness of the measurement method of the prestressing force inside concrete is verified, and the long-term monitoring data are used to investigate various temperature compensation methods. The results show that the proposed method enables effective measurement of small changes in the prestressing force inside the concrete. These changes are caused by the external forces acting on the bridge in service and provide sufficient durability for long-term sensing. The analysis of the prestressing force obtained through long-term monitoring reveals the necessity of conducting temperature compensation for the consistency of the data acquired using the FBG sensor. Moreover, the selection of the thermal expansion coefficient appears also to be of critical importance for temperature compensation.

  8. Current Reversal Due to Coupling Between Asymmetrical Driving Force and Ratchet Potential

    2006-01-01

    Transport of a Brownian particle moving in a periodic potential is investigated in the presence of an asymmetric unbiased external force. The asymmetry of the external force and the asymmetry of the potential are the two ways of inducing a net current. It is found that the competition of the spatial asymmetry of potential with the temporal asymmetry of the external force leads to the phenomena like current reversal. The competition between the two opposite driving factors is a necessary but not a sufficient condition for current reversals.

  9. Interstitial fluid pressure in soft tissue as a result of an externally applied contact pressure.

    Darling, A L; Yalavarthy, P K; Doyley, M M; Dehghani, H; Pogue, B W

    2007-07-21

    Manipulation of interstitial fluid pressure (IFP) has a clinical potential when used in conjunction with near-infrared spectroscopy for the detection of breast cancer. In order to better interpret how the applied pressure alters the vascular space and interstitial water volumes in breast tissue, a study on tissue-mimicking, gelatin phantoms was carried out to mimic the translation of external force into internal pressures. A complete set of three-dimensional (3D) pressure maps were obtained for the interior volumes of phantoms as an external force of 10 mmHg was applied, using mixtures of elastic moduli 19 and 33 kPa to simulate adipose and fibroglandular values of breast tissue. Corresponding linear elastic finite element analysis (FEA) cases were formulated. Shear stress, nonlinear mechanical properties, gravity and tissue geometry were all observed to contribute to internal pressure distribution, with surface shear stresses increasing internal pressures near the surface to greater than twice the applied external pressure. Average pressures by depth were predicted by the linear elastic FEA models. FEA models were run for cases mimicking a 93 kPa tumor inclusion within regions of adipose, fibroglandular tissue, and a composite of the two tissue types to illustrate the localized high fluid pressures caused by a tumor when an external force is applied. The conclusion was that external contact forces can generate potentially clinically useful fluid pressure magnitudes in regions of sharp effective elastic modulus gradients, such as tumor boundaries. PMID:17664598

  10. Photoactive devices including porphyrinoids with coordinating additives

    Forrest, Stephen R; Zimmerman, Jeramy; Yu, Eric K; Thompson, Mark E; Trinh, Cong; Whited, Matthew; Diev, Vlacheslav

    2015-05-12

    Coordinating additives are included in porphyrinoid-based materials to promote intermolecular organization and improve one or more photoelectric characteristics of the materials. The coordinating additives are selected from fullerene compounds and organic compounds having free electron pairs. Combinations of different coordinating additives can be used to tailor the characteristic properties of such porphyrinoid-based materials, including porphyrin oligomers. Bidentate ligands are one type of coordinating additive that can form coordination bonds with a central metal ion of two different porphyrinoid compounds to promote porphyrinoid alignment and/or pi-stacking. The coordinating additives can shift the absorption spectrum of a photoactive material toward higher wavelengths, increase the external quantum efficiency of the material, or both.

  11. Effect of external magnetic effect of external magnetic field annealing on magnetic texture of Mo containing NANOPERM-type alloys

    External magnetic fields are known to modify microstructure of materials during their solidification and/or crystallisation. In an external magnetic field strong particle to particle interactions lead to a highly anisotropic microstructure. If the alloy is in ferromagnetic state, stronger particle magnetization - external field interactions and also particle-to-particle couplings are expected. To reveal the magnetic texture, originally amorphous precursors of Fe76Mo8Cu1B15 were annealed at 510 grad C and 550 grad C in an external longitudinal and transverse magnetic field of 0.025 T and 0.8 T, respectively. Magnetic measurements were applied to follow the changes of saturation magnetization and coercive force. Moessbauer experiments were performed at room and liquid nitrogen temperature to provide an information about orientation of with respect to an external magnetic field. The obtained results were compared with those achieved on zero field annealed samples. We can conclude that such a low external magnetic fields applied during crystallisation cause no significant changes in the magnetic microstructural anisotropy. Afterwards, magneto-optical Kerr effect (MOKE) was applied to investigate possible changes at the surface of the ribbon as a function of annealing temperature and applied magnetic field. We observed combination of uniaxial anisotropy, which originates from the shape anisotropy, and four-fold anisotropy, which is a contribution from crystallites of nanometre size embedded in the residual amorphous matrix. We expect more pronounced effects on cobalt substituted (Fe1-xCox)76Mo8Cu1B15 alloy. (authors)

  12. Answer Set Programming with External Sources

    Redl, Christoph

    2012-01-01

    Answer Set Programming (ASP) is a well-known problem solving approach based on nonmonotonic logic programs and efficient solvers. To enable access to external information, HEX-programs extend programs with external atoms, which allow for a bidirectional communication between the logic program and external sources of computation (e.g., description logic reasoners and Web resources). Current solvers evaluate HEX-programs by a translation to ASP itself, in which values of external atoms are g...

  13. Externalities in Wage Formation and Structural Unemployment

    De La Croix, David

    1993-01-01

    A sectorial general equilibrium model in which externalities among sectors arise through wage envy is presented. Without externalities, equilibrium unemployment is only a function of the product market power of the firm and of demand uncertainty. With externalities, unemployment is higher. It is increasing with union power even though bargaining is efficient. Aggregate demand shock do not modify the magnitude of unemployment. However, when externalities are present, sectorial demand shocks mo...

  14. Efficacy of climate forcings

    Hansen, J.; Sato, M.; Ruedy, R.; Nazarenko, L.; Lacis, A.; Schmidt, G. A.; Russell, G.; Aleinov, I.; Bauer, M.; Bauer, S.; Bell, N.; Cairns, B.; Canuto, V.; Chandler, M.; Cheng, Y.; Del Genio, A.; Faluvegi, G.; Fleming, E.; Friend, A.; Hall, T.; Jackman, C.; Kelley, M.; Kiang, N.; Koch, D.; Lean, J.; Lerner, J.; Lo, K.; Menon, S.; Miller, R.; Minnis, P.; Novakov, T.; Oinas, V.; Perlwitz, Ja.; Perlwitz, Ju.; Rind, D.; Romanou, A.; Shindell, D.; Stone, P.; Sun, S.; Tausnev, N.; Thresher, D.; Wielicki, B.; Wong, T.; Yao, M.; Zhang, S.

    2005-09-01

    We use a global climate model to compare the effectiveness of many climate forcing agents for producing climate change. We find a substantial range in the "efficacy" of different forcings, where the efficacy is the global temperature response per unit forcing relative to the response to CO2 forcing. Anthropogenic CH4 has efficacy ˜110%, which increases to ˜145% when its indirect effects on stratospheric H2O and tropospheric O3 are included, yielding an effective climate forcing of ˜0.8 W/m2 for the period 1750-2000 and making CH4 the largest anthropogenic climate forcing other than CO2. Black carbon (BC) aerosols from biomass burning have a calculated efficacy ˜58%, while fossil fuel BC has an efficacy ˜78%. Accounting for forcing efficacies and for indirect effects via snow albedo and cloud changes, we find that fossil fuel soot, defined as BC + OC (organic carbon), has a net positive forcing while biomass burning BC + OC has a negative forcing. We show that replacement of the traditional instantaneous and adjusted forcings, Fi and Fa, with an easily computed alternative, Fs, yields a better predictor of climate change, i.e., its efficacies are closer to unity. Fs is inferred from flux and temperature changes in a fixed-ocean model run. There is remarkable congruence in the spatial distribution of climate change, normalized to the same forcing Fs, for most climate forcing agents, suggesting that the global forcing has more relevance to regional climate change than may have been anticipated. Increasing greenhouse gases intensify the Hadley circulation in our model, increasing rainfall in the Intertropical Convergence Zone (ITCZ), Eastern United States, and East Asia, while intensifying dry conditions in the subtropics including the Southwest United States, the Mediterranean region, the Middle East, and an expanding Sahel. These features survive in model simulations that use all estimated forcings for the period 1880-2000. Responses to localized forcings, such

  15. Modeling of ribosome dynamics on a ds-mRNA under an external load

    Shakiba, Bahareh; Dayeri, Maryam; Mohammad-Rafiee, Farshid

    2016-07-01

    Protein molecules in cells are synthesized by macromolecular machines called ribosomes. According to the recent experimental data, we reduce the complexity of the ribosome and propose a model to express its activity in six main states. Using our model, we study the translation rate in different biological relevant situations in the presence of external force and the translation through the RNA double stranded region in the absence or presence of the external force. In the present study, we give a quantitative theory for translation rate and show that the ribosome behaves more like a Brownian Ratchet motor. Our findings could shed some light on understanding behaviors of the ribosome in biological conditions.

  16. Modeling of Ribosome Dynamics on a ds-mRNA under an External Load

    Shakiba, Bahareh; Mohammad-Rafiee, Farshid

    2016-01-01

    Protein molecules in cells are synthesized by macromolecular machines called ribosomes. According to recent experimental data, we reduce the complexity of the ribosome and propose a model to express its activity in six main states. Using our model, we study the translation rate in different biological relevant situations in the presence of external force, and translation through the RNA double stranded region in the absence or presence of the external force. In the present study, we give a quantitative theory for translation rate and show that the ribosome behaves more like a Brownian Ratchet motor. Our findings could shed some light on understanding behaviors of the ribosome in biological conditions.

  17. Force reflecting hand controller for manipulator teleoperation

    Bryfogle, Mark D.

    1991-12-01

    A force reflecting hand controller based upon a six degree of freedom fully parallel mechanism, often termed a Stewart Platform, has been designed, constructed, and tested as an integrated system with a slave robot manipulator test bed. A force reflecting hand controller comprises a kinesthetic device capable of transmitting position and orientation commands to a slave robot manipulator while simultaneously representing the environmental interaction forces of the slave manipulator back to the operator through actuators driving the hand controller mechanism. The Stewart Platform was chosen as a novel approach to improve force reflecting teleoperation because of its inherently high ratio of load generation capability to system mass content and the correspondingly high dynamic bandwidth. An additional novelty of the program was to implement closed loop force and torque control about the hand controller mechanism by equipping the handgrip with a six degree of freedom force and torque measuring cell. The mechanical, electrical, computer, and control systems are discussed and system tests are presented.

  18. Casimir-Polder forces on moving atoms

    Polarizable atoms and molecules experience the Casimir-Polder force near magnetoelectric bodies, a force that is induced by quantum fluctuations of the electromagnetic field and the matter. Atoms and molecules in relative motion to a magnetoelectric surface experience an additional velocity-dependent force. We present a full quantum-mechanical treatment of this force and identify a generalized Doppler effect, the time delay between photon emission and reabsorption, and the Roentgen interaction as its three sources. For ground-state atoms, the force is very small and always decelerating, hence commonly known as quantum friction. For atoms and molecules in electronically excited states, on the contrary, both decelerating and accelerating forces can occur depending on the magnitude of the atomic transition frequency relative to the surface-plasmon frequency.

  19. Modeling and boundary force control of microcantilevers utilized in atomic force microscopy for cellular imaging and characterization

    Eslami, Sohrab

    the proposed Euler-Bernoulli model, a more comprehensive model is developed by modeling the probe dynamics and including the effects of the rotary inertia and shear deformation under the same proposed tip-sample interaction force. An extensive comparative study between the Euler-Bernoulli and Timoshenko beam assumptions is conducted for different conditions including different base-excitation amplitudes and higher modes. The results underline that the comprehensive Timoshenko model unveils the effects of the nonlinear interaction force better than the Euler-Bernoulli beam model. In addition to extensive modeling efforts on the microcantilever and its interaction with sample, an adaptive control framework is developed in order to make the microcantilever's tip follow a desired trajectory. This trajectory can further be considered as an important path acquired by the path planning techniques to manipulate the nanoparticles. There is a base excitation considered for this model and can be considered as an input force control to excite the probe by taking advantage of flexibility of the cantilever despite its complexity and under existence of the external nonlinear interaction forces between the tip and sample's surface. When building such complicated controller on top of the proposed comprehensive model, the results could be extended to study a macro-micro hybrid rigid-flexible model of a microrobot to mimic the realistic behavior of the MM3ARTM microrobot. The MM3ARTM microrobot is equipped with a piezoresistive layer which functions as a force sensor and is capable of measuring very slight forces as small as micro to nano-Newton. Two types of controllers are investigated for the case of the tip force control. Lyapunov-based PD and robust adaptive controllers are developed for this purpose and their performances and stabilities are compared. In the experimental part, a platform for performing the automated nanomanipulation and real-time cellular imaging is developed by

  20. Nonsingular cylindrical cloaks with internal–external invisible regions

    Two-dimensional nonsingular cloaks with internal and external invisible regions are presented. Objects can be hidden either in the internal cavity or the external concealment regions without being detected. Also in the latter case, the cloaked objects can receive incoming signals. In order to avoid the singularity (an infinitely large value of the constitutive parameters) which may appear at the inner boundary, the method of adjusting the principal stretches out of the cloaking plane is adopted. Detailed examples and their electromagnetic simulations are presented to validate the design. In addition, the effect of the material loss on the invisible property of the cloaks is also discussed

  1. Additional protocol experience in Romania

    Full text: National Commission for Nuclear Activities Control (CNCAN) is the national regulatory body with regulation, authorization and control responsibilities. CNCAN has the right and obligation to ensure that safeguards are applied, in accordance with the terms of the safeguards agreement, on all source or special fissionable material in all peaceful nuclear activities within the State, under its jurisdiction or carried out under its control anywhere, for the exclusive purpose of verifying that such material is not diverted to nuclear weapons or other nuclear explosive devices. CNCAN has built a strong primary and secondary legislation in order to have a strong legal framework to fulfill the NPT, Safeguards Agreement and Additional Protocol requirements. In respect of the non-proliferation issues CNCAN has as a major goal to strengthen the effectiveness and to improve the efficiency of the safeguards system. Also closer co-operation between the IAEA and CNCAN as coordinator of the national system of accounting for and control of nuclear material has been developed by organizing international and national seminars on the implementation of safeguards and the additional protocol. After the entry into force of the Additional Protocol, CNCAN prepared appropriate declarations and answers to the relevant IAEA questions in order to obtain a drawn conclusion of the absence of undeclared nuclear material and nuclear activities within Romania territory. The IAEA evaluated in Romania not only the results of its nuclear material related activities under the Safeguards Agreement but also the results of its broader, more qualitative, evaluation and verification activities under the Additional Protocol. CNCAN assured that the IAEA inspectors have complementary access according to the Additional Protocol as requested in accordance with the provisions of the Safeguards Agreement and the Additional Protocol and cooperated in resolving in a timely manner, any questions or

  2. Synchronization limit of weakly forced nonlinear oscillators

    Nonlinear oscillators exhibit synchronization (injection-locking) to external periodic forcings, which underlies the mutual synchronization in networks of nonlinear oscillators. Despite its history of synchronization and the practical importance of injection-locking to date, there are many important open problems of an efficient injection-locking for a given oscillator. In this work, I elucidate a hidden mechanism governing the synchronization limit under weak forcings, which is related to a widely known inequality; Hölder's inequality. This mechanism enables us to understand how and why the efficient injection-locking is realized; a general theory of synchronization limit is constructed where the maximization of the synchronization range or the stability of synchronization for general forcings including pulse trains, and a fundamental limit of general m : n phase locking, are clarified systematically. These synchronization limits and their utility are systematically verified in the Hodgkin–Huxley neuron model as an example. (fast track communication)

  3. Floating and flying ferrofluid bridges induced by external magnetic fields

    Ma, Rongchao; Zhou, Yixin; Liu, Jing

    2015-04-01

    A ferrofluid is a mixture that exhibits both magnetism and fluidity. This merit enables the ferrofluid to be used in a wide variety of areas. Here we show that a floating ferrofluid bridge can be induced between two separated boards under a balanced external magnetic field generated by two magnets, while a flying ferrofluid bridge can be induced under an unbalanced external magnetic field generated by only one magnet. The mechanisms of the ferrofluid bridges were discussed and the corresponding mathematical equations were also established to describe the interacting magnetic force between the ferro particles inside the ferrofluid. This work answered a basic question that, except for the well-known floating water bridges that are related to electricity, one can also build up a liquid bridge that is related to magnetism.

  4. 49 CFR 195.108 - External pressure.

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false External pressure. 195.108 Section 195.108... PIPELINE Design Requirements § 195.108 External pressure. Any external pressure that will be exerted on the pipe must be provided for in designing a pipeline system....

  5. Quantum fictitious forces

    Bialynicki-Birula, I; Cirone, M.A.; Dahl, Jens Peder;

    2002-01-01

    We present Heisenberg's equation of motion for the radial variable of a free non-relativistic particle in D dimensions. The resulting radial force consists of three contributions: (i) the quantum fictitious force which is either attractive or repulsive depending on the number of dimensions, (ii......) a singular quantum force located at the origin, and (iii) the centrifugal force associated with non-vanishing angular momentum. Moreover, we use Heisenberg's uncertainty relation to introduce a lower bound for the kinetic energy of an ensemble of neutral particles. This bound is quadratic in the number...... of atoms and can be traced back to the repulsive quantum fictitious potential. All three forces arise for a free particle: "Force without force"....

  6. Forces in molecules.

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

    2007-01-01

    Chemistry is determined by the electrostatic forces acting within a collection of nuclei and electrons. The attraction of the nuclei for the electrons is the only attractive force in a molecule and is the force responsible for the bonding between atoms. This is the attractive force acting on the electrons in the Ehrenfest force and on the nuclei in the Feynman force, one that is countered by the repulsion between the electrons in the former and by the repulsion between the nuclei in the latter. The virial theorem relates these forces to the energy changes resulting from interactions between atoms. All bonding, as signified by the presence of a bond path, has a common origin in terms of the mechanics determined by the Ehrenfest, Feynman and virial theorems. This paper is concerned in particular with the mechanics of interaction encountered in what are classically described as 'nonbonded interactions'--are atoms that 'touch' bonded or repelling one another? PMID:17328425

  7. Quantum fictitious forces

    Bialynicki-Birula, I; Cirone, M.A.; Dahl, Jens Peder; Seligman, T.H.; Straub, F.; Schleich, W.P.

    We present Heisenberg's equation of motion for the radial variable of a free non-relativistic particle in D dimensions. The resulting radial force consists of three contributions: (i) the quantum fictitious force which is either attractive or repulsive depending on the number of dimensions, (ii) a...... singular quantum force located at the origin, and (iii) the centrifugal force associated with non-vanishing angular momentum. Moreover, we use Heisenberg's uncertainty relation to introduce a lower bound for the kinetic energy of an ensemble of neutral particles. This bound is quadratic in the number of...... atoms and can be traced back to the repulsive quantum fictitious potential. All three forces arise for a free particle: "Force without force"....

  8. Forced spaser oscillations

    Lisyansky, Alexander A.; Andrianov, Eugeney S.; Dorofeenko, Alexander V.; Pukhov, Alexander A.; Vinogradov, Alexey P.

    2012-10-01

    We study oscillations of a spaser driven by an external optical wave. When the frequency of the external field is shifted from the frequency of an autonomous spaser, the spaser exhibits stochastic oscillations at low field intensity. The plasmon oscillations lock to the frequency of the external field only when the field amplitude exceeds a threshold value. We find a region of external field amplitude and the frequency detuning (the Arnold tongue) for which the spaser becomes synchronized with the external wave. We obtain the conditions upon the amplitude and frequency of the external field (the curve of compensation) at which the spaser's dipole moment oscillates with a phase shift of π relatively to the external wave. For these values of the amplitude and frequency, the loss in the metal nanoparticles within the spaser is exactly compensated for by the gain. It is expected that if these conditions are not satisfied, then due to loss or gain of energy, the amplitude of the wave travelling along the system of spasers either tends to the curve of compensation or leave the Arnold tongue. We also consider cooperative phenomena showing that in a chain of interacting spasers, depending on the values of the coupling constants, either all spasers oscillate in phase or a nonlinear autowave travels in the system. In the latter scenario, the traveling wave is harmonic, unlike excitations in other nonlinear systems. Due to the nonlinear nature of the system, any initial distribution of spaser states evolves into one of these steady states.

  9. A Comparison of Classical Force-Fields for Molecular Dynamics Simulations of Lubricants

    James P. Ewen

    2016-08-01

    Full Text Available For the successful development and application of lubricants, a full understanding of their complex nanoscale behavior under a wide range of external conditions is required, but this is difficult to obtain experimentally. Nonequilibrium molecular dynamics (NEMD simulations can be used to yield unique insights into the atomic-scale structure and friction of lubricants and additives; however, the accuracy of the results depend on the chosen force-field. In this study, we demonstrate that the use of an accurate, all-atom force-field is critical in order to; (i accurately predict important properties of long-chain, linear molecules; and (ii reproduce experimental friction behavior of multi-component tribological systems. In particular, we focus on n-hexadecane, an important model lubricant with a wide range of industrial applications. Moreover, simulating conditions common in tribological systems, i.e., high temperatures and pressures (HTHP, allows the limits of the selected force-fields to be tested. In the first section, a large number of united-atom and all-atom force-fields are benchmarked in terms of their density and viscosity prediction accuracy of n-hexadecane using equilibrium molecular dynamics (EMD simulations at ambient and HTHP conditions. Whilst united-atom force-fields accurately reproduce experimental density, the viscosity is significantly under-predicted compared to all-atom force-fields and experiments. Moreover, some all-tom force-fields yield elevated melting points, leading to significant overestimation of both the density and viscosity. In the second section, the most accurate united-atom and all-atom force-field are compared in confined NEMD simulations which probe the structure and friction of stearic acid adsorbed on iron oxide and separated by a thin layer of n-hexadecane. The united-atom force-field provides an accurate representation of the structure of the confined stearic acid film; however, friction coefficients are

  10. Dynamics of single vortex line in the field of external alternative current

    Motion of a single vortex line in steady state under action of an external force due to alternate transport current, viscosity and pinning forces as well as the Magnus force has been investigated. The presence of the effective vortex mass was also taken into account. The vibrational spectrum of the line had two branches: the low- and high-frequency ones. The latter branch appears due to taking the effective vortex mass into consideration. In present report, the absorption of energy by the vortex, depending on the frequency of external transport current, has been calculated. The frequency dependence of the absorption demonstrates two typical resonance maxima, one of them being due to depinning frequency of the vortex, and the other one due to its cyclotron resonance. The influences of other forces on dynamics of the single vortex line were considered

  11. Additive and polynomial representations

    Krantz, David H; Suppes, Patrick

    1971-01-01

    Additive and Polynomial Representations deals with major representation theorems in which the qualitative structure is reflected as some polynomial function of one or more numerical functions defined on the basic entities. Examples are additive expressions of a single measure (such as the probability of disjoint events being the sum of their probabilities), and additive expressions of two measures (such as the logarithm of momentum being the sum of log mass and log velocity terms). The book describes the three basic procedures of fundamental measurement as the mathematical pivot, as the utiliz

  12. Optical measurement of DNA torsional modulus under various stretching forces

    Choi, Jaehyuck

    2005-03-01

    Optical measurement of DNA torsional modulus under various stretching forces Jaehyuck Choi[1], Kai Zhao[2] Y.-H. Lo[1] [1] Department of Electrical and Computer Engineering, [2] Department of Physics University of California at San Diego, La Jolla, California 92093-0407 We have measured the torsional spring modulus of a double stranded-DNA by applying an external torque around the axis of a vertically stretched DNA molecule. We observed that the torsional modulus of the DNA increases with stretching force. This result supports the hypothesis that an applied stretching force may raise the intrinsic torsional modulus of ds-DNA via elastic coupling between twisting and stretching. This further verifies that the torsional modulus value (C = 46.5 +/- 10 pN nm2) of a ds-DNA investigated under Brownian torque (no external force and torque) could be the pure intrinsic value without contribution from other effects such as stretching, bending, or buckling of DNA chains.

  13. Lateral Casimir Force between Two Sinusoidally Corrugated Eccentric Cylinders Using Proximity Force Approximation

    Setare, M R

    2014-01-01

    This paper is devoted to the presentation of the lateral Casimir force between two sinusoidally corrugated eccentric cylinders. Despite that applying scattering matrix method explains the problem exactly, procedure of applying this method is somehow complicated specially at nonzero temperature. Using the proximity force approximation (PFA) helps to achieve the lateral Casimir force in a truly explicit manner. We assume the cylinders to be slightly eccentric with similar radiuses and separations much smaller than corrugations' wave length for the validity of PFA. For such short distances the effect of finite conductivity would be non negligible. In addition to the effect of finite conductivity, we investigate thermal corrections of the lateral Casimir force to reduce the inaccuracy of the result obtained by PFA. Assuming the Casimir force density between two parallel plates, the normal Casimir force between two cylinders is obtained. With the aid of additive summation of the Casimir energy between cylinders wi...

  14. External noise when using biofuel

    The aim of this study has been to cover sources of noise dealing with all steps in a biofuel chain; producing, transporting, storing and firing the biofuel. When the availability of relevant test results from noise surveys is not so good and mostly badly documented, the study has been concentrated on estimation of external noise for planning and design purposes, from a prospective biofuel-fired plant. A synoptic tabulation of estimated acoustic power levels from different noise sources, has been done. The results from measurements of external noise from different existing combined power and heating plants are tabulated. The Nordic model for simulation of external noise has been used for a prospective plant - VEGA - designed by Vattenfall. The aim has been to estimate its noise pollutions at critical points at the nearest residential area (250 m from the fenced industry area). The software - ILYD - is easy to handle, but knowledge about the model is necessary. A requisite for the reliability is the access to measurements or estimations of different sources of noise, at different levels of octaves from 63 to 8000 Hz. The degree of accuracy increases with the number of broad band sources, that are integrated. Using ILYD with available data, a night limit of 40 dB(A) should be possible to fulfill with good degree of accuracy at VEGA, between 10 pm and 7 am, with good planning and under normal operation conditions. A demand for 35 dB(A) as a limit can be harder to fulfill, especially at mornings from 6 to 7. Noise from heavy vehicles within the plant area is classified as industrial noise and not as road traffic noise. This type of noise depends very much on the way of driving and assumed acceleration. Concerning wheel-mounted loaders, they may then only be used during daytime. The simulations show, that even at daytime from 7 to 6 pm, it would be possible to use an acoustically damped chipping machine, inside the power industry area. 31 refs, 13 figs, tabs, 8

  15. Food Additives and Hyperkinesis

    Wender, Ester H.

    1977-01-01

    The hypothesis that food additives are causally associated with hyperkinesis and learning disabilities in children is reviewed, and available data are summarized. Available from: American Medical Association 535 North Dearborn Street Chicago, Illinois 60610. (JG)

  16. Groups – Additive Notation

    Coghetto Roland

    2015-06-01

    Full Text Available We translate the articles covering group theory already available in the Mizar Mathematical Library from multiplicative into additive notation. We adapt the works of Wojciech A. Trybulec [41, 42, 43] and Artur Korniłowicz [25].

  17. Sparse Additive Models

    Ravikumar, Pradeep; Lafferty, John; Liu, Han; Wasserman, Larry

    2007-01-01

    We present a new class of methods for high-dimensional nonparametric regression and classification called sparse additive models (SpAM). Our methods combine ideas from sparse linear modeling and additive nonparametric regression. We derive an algorithm for fitting the models that is practical and effective even when the number of covariates is larger than the sample size. SpAM is closely related to the COSSO model of Lin and Zhang (2006), but decouples smoothing and sparsity, enabling the use...

  18. Additively Manufactured Propulsion System

    Dushku, Matthew; Mueller, Paul

    2012-01-01

    New high-performance, carbon-fiber reinforced polymer material allows additive manufacturing to produce pressure vessels capable of high pressures (thousands of pounds per square inch). This advancement in turn allows integral hybrid propulsion which is revolutionary for both CubeSats and additively-manufactured spacecraft. Hybrid propulsion offers simplicity as compared to bipropellant liquid propulsion, significantly better safety compared to solid or monopropellant hydrazine propulsion, an...

  19. External analysis of the smartphone industry in Spain

    Nájera Aragón, Fernando

    2014-01-01

    The main purpose of this end-of-grade project will be the external analysis of an industrial sector, in this case the Smartphone industry. The analysis will be based on Porter’s competitive force model, which allows us to study the competition among the sector and what companies are now leading the market and why. Although it is a market in continuous growth worldwide, this project will focus on how the smartphone market works in Spain. The project will be divided in four main parts, intro...

  20. External hazards in PSA program for VVER 440/213

    The basic PSA study for the Dukovany NPP was completed in 1995. Since then a Living PSA program has come into force. All the PSA related activities are undertaken under the umbrella called Living PSA. They include support of risk management, data collection and information transfer, maintenance and improvement of PSA models. To support regulatory decision making the full scope PSA is under development. External hazards identified are: earthquake initiators, aircraft crushes and extreme rainfalls. Seismic PSA is not scheduled for near future, but team is being build up and a test example of seismic event impact is being modelled for trial evaluation